annotate Python/dtoa.c @ 58664:993f703a61ba

Merged revisions 77484,77487,77561,77570,77593,77603,77608,77667,77702-77703,77739,77858,77887,77889 via svnmerge from svn+ssh://pythondev@svn.python.org/python/trunk ........ r77484 | skip.montanaro | 2010-01-13 19:12:34 -0600 (Wed, 13 Jan 2010) | 4 lines Update PyEval_EvalFrame to PyEval_EvalFrameEx. This looks to have been done partially before. Also add a comment describing how this might have to work with different versions of the interpreter. ........ r77487 | ezio.melotti | 2010-01-14 05:34:10 -0600 (Thu, 14 Jan 2010) | 1 line Fixed typo ........ r77561 | georg.brandl | 2010-01-17 02:42:30 -0600 (Sun, 17 Jan 2010) | 1 line #7699: improve datetime docs: straightforward linking to strftime/strptime section, mark classmethods as such. ........ r77570 | georg.brandl | 2010-01-17 06:14:42 -0600 (Sun, 17 Jan 2010) | 1 line Add note about usage of STRINGLIB_EMPTY. ........ r77593 | georg.brandl | 2010-01-17 17:33:53 -0600 (Sun, 17 Jan 2010) | 1 line Fix internal reference. ........ r77603 | benjamin.peterson | 2010-01-18 17:07:56 -0600 (Mon, 18 Jan 2010) | 8 lines data descriptors do not override the class dictionary if __get__ is not defined Adjust documentation and add a test to verify this behavior. See http://mail.python.org/pipermail/python-dev/2010-January/095637.html for discussion. ........ r77608 | gregory.p.smith | 2010-01-19 02:19:03 -0600 (Tue, 19 Jan 2010) | 6 lines Do not compile stubs for the sha2 series hashes in the openssl hashlib module when the openssl version is too old to support them. That leads both compiled code bloat and to unittests attempting to test implementations that don't exist for comparison purposes on such platforms. ........ r77667 | mark.dickinson | 2010-01-21 12:32:27 -0600 (Thu, 21 Jan 2010) | 1 line Add two more test_strtod test values. ........ r77702 | georg.brandl | 2010-01-23 02:43:31 -0600 (Sat, 23 Jan 2010) | 1 line #7762: fix refcount annotation of PyUnicode_Tailmatch(). ........ r77703 | georg.brandl | 2010-01-23 02:47:54 -0600 (Sat, 23 Jan 2010) | 1 line #7725: fix referencing issue. ........ r77739 | benjamin.peterson | 2010-01-24 21:52:52 -0600 (Sun, 24 Jan 2010) | 1 line mention from_float() in error message ........ r77858 | georg.brandl | 2010-01-30 11:57:48 -0600 (Sat, 30 Jan 2010) | 1 line #7802: fix invalid example (heh). ........ r77887 | georg.brandl | 2010-01-31 12:51:49 -0600 (Sun, 31 Jan 2010) | 5 lines Fix-up ftplib documentation: move exception descriptions to toplevel, not inside a class remove attribution in "versionadded" spell and grammar check docstring of FTP_TLS ........ r77889 | michael.foord | 2010-01-31 13:59:26 -0600 (Sun, 31 Jan 2010) | 1 line Minor modification to unittest documentation. ........
author Benjamin Peterson <benjamin@python.org>
date Wed, 03 Feb 2010 02:35:45 +0000
parents be12d3621519
children 8410f83fd159
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1 /****************************************************************
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2 *
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3 * The author of this software is David M. Gay.
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4 *
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5 * Copyright (c) 1991, 2000, 2001 by Lucent Technologies.
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6 *
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7 * Permission to use, copy, modify, and distribute this software for any
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8 * purpose without fee is hereby granted, provided that this entire notice
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9 * is included in all copies of any software which is or includes a copy
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10 * or modification of this software and in all copies of the supporting
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11 * documentation for such software.
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12 *
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13 * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED
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14 * WARRANTY. IN PARTICULAR, NEITHER THE AUTHOR NOR LUCENT MAKES ANY
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15 * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY
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16 * OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE.
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17 *
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18 ***************************************************************/
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19
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20 /****************************************************************
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21 * This is dtoa.c by David M. Gay, downloaded from
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22 * http://www.netlib.org/fp/dtoa.c on April 15, 2009 and modified for
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23 * inclusion into the Python core by Mark E. T. Dickinson and Eric V. Smith.
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24 *
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25 * Please remember to check http://www.netlib.org/fp regularly (and especially
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26 * before any Python release) for bugfixes and updates.
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27 *
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28 * The major modifications from Gay's original code are as follows:
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29 *
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30 * 0. The original code has been specialized to Python's needs by removing
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31 * many of the #ifdef'd sections. In particular, code to support VAX and
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32 * IBM floating-point formats, hex NaNs, hex floats, locale-aware
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33 * treatment of the decimal point, and setting of the inexact flag have
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34 * been removed.
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35 *
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36 * 1. We use PyMem_Malloc and PyMem_Free in place of malloc and free.
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37 *
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38 * 2. The public functions strtod, dtoa and freedtoa all now have
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39 * a _Py_dg_ prefix.
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40 *
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41 * 3. Instead of assuming that PyMem_Malloc always succeeds, we thread
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42 * PyMem_Malloc failures through the code. The functions
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43 *
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44 * Balloc, multadd, s2b, i2b, mult, pow5mult, lshift, diff, d2b
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45 *
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46 * of return type *Bigint all return NULL to indicate a malloc failure.
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47 * Similarly, rv_alloc and nrv_alloc (return type char *) return NULL on
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48 * failure. bigcomp now has return type int (it used to be void) and
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49 * returns -1 on failure and 0 otherwise. _Py_dg_dtoa returns NULL
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50 * on failure. _Py_dg_strtod indicates failure due to malloc failure
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51 * by returning -1.0, setting errno=ENOMEM and *se to s00.
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52 *
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53 * 4. The static variable dtoa_result has been removed. Callers of
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54 * _Py_dg_dtoa are expected to call _Py_dg_freedtoa to free
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55 * the memory allocated by _Py_dg_dtoa.
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56 *
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57 * 5. The code has been reformatted to better fit with Python's
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58 * C style guide (PEP 7).
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59 *
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60 * 6. A bug in the memory allocation has been fixed: to avoid FREEing memory
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61 * that hasn't been MALLOC'ed, private_mem should only be used when k <=
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62 * Kmax.
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63 *
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64 * 7. _Py_dg_strtod has been modified so that it doesn't accept strings with
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65 * leading whitespace.
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66 *
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67 ***************************************************************/
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68
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69 /* Please send bug reports for the original dtoa.c code to David M. Gay (dmg
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70 * at acm dot org, with " at " changed at "@" and " dot " changed to ".").
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71 * Please report bugs for this modified version using the Python issue tracker
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72 * (http://bugs.python.org). */
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73
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74 /* On a machine with IEEE extended-precision registers, it is
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75 * necessary to specify double-precision (53-bit) rounding precision
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76 * before invoking strtod or dtoa. If the machine uses (the equivalent
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77 * of) Intel 80x87 arithmetic, the call
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78 * _control87(PC_53, MCW_PC);
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79 * does this with many compilers. Whether this or another call is
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80 * appropriate depends on the compiler; for this to work, it may be
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81 * necessary to #include "float.h" or another system-dependent header
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82 * file.
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83 */
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84
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85 /* strtod for IEEE-, VAX-, and IBM-arithmetic machines.
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86 *
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87 * This strtod returns a nearest machine number to the input decimal
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88 * string (or sets errno to ERANGE). With IEEE arithmetic, ties are
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89 * broken by the IEEE round-even rule. Otherwise ties are broken by
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90 * biased rounding (add half and chop).
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91 *
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92 * Inspired loosely by William D. Clinger's paper "How to Read Floating
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93 * Point Numbers Accurately" [Proc. ACM SIGPLAN '90, pp. 92-101].
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94 *
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95 * Modifications:
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96 *
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97 * 1. We only require IEEE, IBM, or VAX double-precision
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98 * arithmetic (not IEEE double-extended).
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99 * 2. We get by with floating-point arithmetic in a case that
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100 * Clinger missed -- when we're computing d * 10^n
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101 * for a small integer d and the integer n is not too
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102 * much larger than 22 (the maximum integer k for which
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103 * we can represent 10^k exactly), we may be able to
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104 * compute (d*10^k) * 10^(e-k) with just one roundoff.
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105 * 3. Rather than a bit-at-a-time adjustment of the binary
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106 * result in the hard case, we use floating-point
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107 * arithmetic to determine the adjustment to within
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108 * one bit; only in really hard cases do we need to
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109 * compute a second residual.
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110 * 4. Because of 3., we don't need a large table of powers of 10
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111 * for ten-to-e (just some small tables, e.g. of 10^k
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112 * for 0 <= k <= 22).
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113 */
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114
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115 /* Linking of Python's #defines to Gay's #defines starts here. */
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116
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117 #include "Python.h"
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118
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119 /* if PY_NO_SHORT_FLOAT_REPR is defined, then don't even try to compile
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120 the following code */
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121 #ifndef PY_NO_SHORT_FLOAT_REPR
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122
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123 #include "float.h"
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124
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125 #define MALLOC PyMem_Malloc
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126 #define FREE PyMem_Free
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127
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128 /* This code should also work for ARM mixed-endian format on little-endian
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129 machines, where doubles have byte order 45670123 (in increasing address
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130 order, 0 being the least significant byte). */
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131 #ifdef DOUBLE_IS_LITTLE_ENDIAN_IEEE754
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132 # define IEEE_8087
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133 #endif
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134 #if defined(DOUBLE_IS_BIG_ENDIAN_IEEE754) || \
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135 defined(DOUBLE_IS_ARM_MIXED_ENDIAN_IEEE754)
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136 # define IEEE_MC68k
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137 #endif
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138 #if defined(IEEE_8087) + defined(IEEE_MC68k) != 1
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139 #error "Exactly one of IEEE_8087 or IEEE_MC68k should be defined."
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140 #endif
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141
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142 /* The code below assumes that the endianness of integers matches the
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143 endianness of the two 32-bit words of a double. Check this. */
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144 #if defined(WORDS_BIGENDIAN) && (defined(DOUBLE_IS_LITTLE_ENDIAN_IEEE754) || \
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145 defined(DOUBLE_IS_ARM_MIXED_ENDIAN_IEEE754))
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146 #error "doubles and ints have incompatible endianness"
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147 #endif
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148
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149 #if !defined(WORDS_BIGENDIAN) && defined(DOUBLE_IS_BIG_ENDIAN_IEEE754)
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150 #error "doubles and ints have incompatible endianness"
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151 #endif
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152
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153
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154 #if defined(HAVE_UINT32_T) && defined(HAVE_INT32_T)
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155 typedef PY_UINT32_T ULong;
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156 typedef PY_INT32_T Long;
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157 #else
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158 #error "Failed to find an exact-width 32-bit integer type"
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159 #endif
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160
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161 #if defined(HAVE_UINT64_T)
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162 #define ULLong PY_UINT64_T
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163 #else
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164 #undef ULLong
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165 #endif
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166
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167 #undef DEBUG
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168 #ifdef Py_DEBUG
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169 #define DEBUG
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170 #endif
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171
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172 /* End Python #define linking */
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173
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174 #ifdef DEBUG
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175 #define Bug(x) {fprintf(stderr, "%s\n", x); exit(1);}
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176 #endif
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177
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178 #ifndef PRIVATE_MEM
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179 #define PRIVATE_MEM 2304
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180 #endif
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181 #define PRIVATE_mem ((PRIVATE_MEM+sizeof(double)-1)/sizeof(double))
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182 static double private_mem[PRIVATE_mem], *pmem_next = private_mem;
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183
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184 #ifdef __cplusplus
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185 extern "C" {
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186 #endif
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187
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188 typedef union { double d; ULong L[2]; } U;
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189
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190 #ifdef IEEE_8087
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191 #define word0(x) (x)->L[1]
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192 #define word1(x) (x)->L[0]
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193 #else
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194 #define word0(x) (x)->L[0]
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195 #define word1(x) (x)->L[1]
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196 #endif
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197 #define dval(x) (x)->d
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198
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199 #ifndef STRTOD_DIGLIM
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200 #define STRTOD_DIGLIM 40
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201 #endif
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202
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203 /* maximum permitted exponent value for strtod; exponents larger than
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204 MAX_ABS_EXP in absolute value get truncated to +-MAX_ABS_EXP. MAX_ABS_EXP
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205 should fit into an int. */
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206 #ifndef MAX_ABS_EXP
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207 #define MAX_ABS_EXP 19999U
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208 #endif
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209
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210 /* The following definition of Storeinc is appropriate for MIPS processors.
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211 * An alternative that might be better on some machines is
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212 * #define Storeinc(a,b,c) (*a++ = b << 16 | c & 0xffff)
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213 */
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214 #if defined(IEEE_8087)
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215 #define Storeinc(a,b,c) (((unsigned short *)a)[1] = (unsigned short)b, \
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216 ((unsigned short *)a)[0] = (unsigned short)c, a++)
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217 #else
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218 #define Storeinc(a,b,c) (((unsigned short *)a)[0] = (unsigned short)b, \
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219 ((unsigned short *)a)[1] = (unsigned short)c, a++)
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220 #endif
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221
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222 /* #define P DBL_MANT_DIG */
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223 /* Ten_pmax = floor(P*log(2)/log(5)) */
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224 /* Bletch = (highest power of 2 < DBL_MAX_10_EXP) / 16 */
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225 /* Quick_max = floor((P-1)*log(FLT_RADIX)/log(10) - 1) */
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226 /* Int_max = floor(P*log(FLT_RADIX)/log(10) - 1) */
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227
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228 #define Exp_shift 20
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229 #define Exp_shift1 20
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230 #define Exp_msk1 0x100000
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231 #define Exp_msk11 0x100000
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232 #define Exp_mask 0x7ff00000
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233 #define P 53
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234 #define Nbits 53
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235 #define Bias 1023
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236 #define Emax 1023
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237 #define Emin (-1022)
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238 #define Etiny (-1074) /* smallest denormal is 2**Etiny */
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239 #define Exp_1 0x3ff00000
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240 #define Exp_11 0x3ff00000
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241 #define Ebits 11
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242 #define Frac_mask 0xfffff
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243 #define Frac_mask1 0xfffff
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244 #define Ten_pmax 22
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245 #define Bletch 0x10
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246 #define Bndry_mask 0xfffff
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247 #define Bndry_mask1 0xfffff
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248 #define Sign_bit 0x80000000
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249 #define Log2P 1
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250 #define Tiny0 0
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251 #define Tiny1 1
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252 #define Quick_max 14
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253 #define Int_max 14
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254
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255 #ifndef Flt_Rounds
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256 #ifdef FLT_ROUNDS
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257 #define Flt_Rounds FLT_ROUNDS
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258 #else
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259 #define Flt_Rounds 1
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260 #endif
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261 #endif /*Flt_Rounds*/
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262
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263 #define Rounding Flt_Rounds
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264
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265 #define Big0 (Frac_mask1 | Exp_msk1*(DBL_MAX_EXP+Bias-1))
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266 #define Big1 0xffffffff
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267
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268 /* struct BCinfo is used to pass information from _Py_dg_strtod to bigcomp */
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269
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270 typedef struct BCinfo BCinfo;
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271 struct
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272 BCinfo {
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273 int e0, nd, nd0, scale;
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274 };
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275
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276 #define FFFFFFFF 0xffffffffUL
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277
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278 #define Kmax 7
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279
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280 /* struct Bigint is used to represent arbitrary-precision integers. These
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281 integers are stored in sign-magnitude format, with the magnitude stored as
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282 an array of base 2**32 digits. Bigints are always normalized: if x is a
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283 Bigint then x->wds >= 1, and either x->wds == 1 or x[wds-1] is nonzero.
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284
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285 The Bigint fields are as follows:
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286
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287 - next is a header used by Balloc and Bfree to keep track of lists
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288 of freed Bigints; it's also used for the linked list of
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289 powers of 5 of the form 5**2**i used by pow5mult.
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290 - k indicates which pool this Bigint was allocated from
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291 - maxwds is the maximum number of words space was allocated for
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292 (usually maxwds == 2**k)
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293 - sign is 1 for negative Bigints, 0 for positive. The sign is unused
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294 (ignored on inputs, set to 0 on outputs) in almost all operations
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295 involving Bigints: a notable exception is the diff function, which
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296 ignores signs on inputs but sets the sign of the output correctly.
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297 - wds is the actual number of significant words
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298 - x contains the vector of words (digits) for this Bigint, from least
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299 significant (x[0]) to most significant (x[wds-1]).
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300 */
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301
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302 struct
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303 Bigint {
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304 struct Bigint *next;
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305 int k, maxwds, sign, wds;
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306 ULong x[1];
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307 };
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308
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309 typedef struct Bigint Bigint;
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310
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311 #ifndef Py_USING_MEMORY_DEBUGGER
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312
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313 /* Memory management: memory is allocated from, and returned to, Kmax+1 pools
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314 of memory, where pool k (0 <= k <= Kmax) is for Bigints b with b->maxwds ==
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315 1 << k. These pools are maintained as linked lists, with freelist[k]
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316 pointing to the head of the list for pool k.
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317
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318 On allocation, if there's no free slot in the appropriate pool, MALLOC is
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319 called to get more memory. This memory is not returned to the system until
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320 Python quits. There's also a private memory pool that's allocated from
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321 in preference to using MALLOC.
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322
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323 For Bigints with more than (1 << Kmax) digits (which implies at least 1233
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324 decimal digits), memory is directly allocated using MALLOC, and freed using
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325 FREE.
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326
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327 XXX: it would be easy to bypass this memory-management system and
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328 translate each call to Balloc into a call to PyMem_Malloc, and each
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329 Bfree to PyMem_Free. Investigate whether this has any significant
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330 performance on impact. */
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331
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332 static Bigint *freelist[Kmax+1];
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333
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334 /* Allocate space for a Bigint with up to 1<<k digits */
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335
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336 static Bigint *
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337 Balloc(int k)
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338 {
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339 int x;
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340 Bigint *rv;
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341 unsigned int len;
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342
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343 if (k <= Kmax && (rv = freelist[k]))
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344 freelist[k] = rv->next;
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345 else {
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346 x = 1 << k;
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347 len = (sizeof(Bigint) + (x-1)*sizeof(ULong) + sizeof(double) - 1)
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348 /sizeof(double);
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349 if (k <= Kmax && pmem_next - private_mem + len <= PRIVATE_mem) {
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350 rv = (Bigint*)pmem_next;
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351 pmem_next += len;
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352 }
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353 else {
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354 rv = (Bigint*)MALLOC(len*sizeof(double));
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355 if (rv == NULL)
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356 return NULL;
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357 }
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358 rv->k = k;
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359 rv->maxwds = x;
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360 }
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361 rv->sign = rv->wds = 0;
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362 return rv;
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363 }
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364
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365 /* Free a Bigint allocated with Balloc */
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366
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367 static void
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368 Bfree(Bigint *v)
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369 {
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370 if (v) {
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371 if (v->k > Kmax)
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372 FREE((void*)v);
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373 else {
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374 v->next = freelist[v->k];
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375 freelist[v->k] = v;
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376 }
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377 }
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378 }
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379
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380 #else
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381
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382 /* Alternative versions of Balloc and Bfree that use PyMem_Malloc and
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383 PyMem_Free directly in place of the custom memory allocation scheme above.
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384 These are provided for the benefit of memory debugging tools like
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385 Valgrind. */
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386
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387 /* Allocate space for a Bigint with up to 1<<k digits */
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388
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389 static Bigint *
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390 Balloc(int k)
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391 {
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392 int x;
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393 Bigint *rv;
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394 unsigned int len;
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395
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396 x = 1 << k;
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397 len = (sizeof(Bigint) + (x-1)*sizeof(ULong) + sizeof(double) - 1)
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398 /sizeof(double);
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399
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400 rv = (Bigint*)MALLOC(len*sizeof(double));
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401 if (rv == NULL)
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402 return NULL;
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403
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404 rv->k = k;
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405 rv->maxwds = x;
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406 rv->sign = rv->wds = 0;
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407 return rv;
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408 }
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409
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410 /* Free a Bigint allocated with Balloc */
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411
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412 static void
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413 Bfree(Bigint *v)
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414 {
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415 if (v) {
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416 FREE((void*)v);
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417 }
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418 }
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419
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420 #endif /* Py_USING_MEMORY_DEBUGGER */
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421
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422 #define Bcopy(x,y) memcpy((char *)&x->sign, (char *)&y->sign, \
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423 y->wds*sizeof(Long) + 2*sizeof(int))
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424
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425 /* Multiply a Bigint b by m and add a. Either modifies b in place and returns
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426 a pointer to the modified b, or Bfrees b and returns a pointer to a copy.
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427 On failure, return NULL. In this case, b will have been already freed. */
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428
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429 static Bigint *
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430 multadd(Bigint *b, int m, int a) /* multiply by m and add a */
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431 {
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432 int i, wds;
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433 #ifdef ULLong
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434 ULong *x;
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435 ULLong carry, y;
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436 #else
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437 ULong carry, *x, y;
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438 ULong xi, z;
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439 #endif
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440 Bigint *b1;
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441
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442 wds = b->wds;
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443 x = b->x;
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444 i = 0;
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445 carry = a;
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446 do {
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447 #ifdef ULLong
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448 y = *x * (ULLong)m + carry;
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449 carry = y >> 32;
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450 *x++ = (ULong)(y & FFFFFFFF);
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451 #else
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452 xi = *x;
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453 y = (xi & 0xffff) * m + carry;
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454 z = (xi >> 16) * m + (y >> 16);
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455 carry = z >> 16;
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456 *x++ = (z << 16) + (y & 0xffff);
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457 #endif
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458 }
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459 while(++i < wds);
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460 if (carry) {
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461 if (wds >= b->maxwds) {
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462 b1 = Balloc(b->k+1);
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463 if (b1 == NULL){
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464 Bfree(b);
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465 return NULL;
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466 }
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467 Bcopy(b1, b);
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468 Bfree(b);
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469 b = b1;
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470 }
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471 b->x[wds++] = (ULong)carry;
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472 b->wds = wds;
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473 }
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474 return b;
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475 }
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476
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477 /* convert a string s containing nd decimal digits (possibly containing a
97ae7a709c1d Issue #1580: use short float repr where possible.
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478 decimal separator at position nd0, which is ignored) to a Bigint. This
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479 function carries on where the parsing code in _Py_dg_strtod leaves off: on
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480 entry, y9 contains the result of converting the first 9 digits. Returns
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481 NULL on failure. */
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482
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483 static Bigint *
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484 s2b(const char *s, int nd0, int nd, ULong y9)
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485 {
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486 Bigint *b;
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487 int i, k;
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488 Long x, y;
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489
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490 x = (nd + 8) / 9;
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491 for(k = 0, y = 1; x > y; y <<= 1, k++) ;
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492 b = Balloc(k);
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493 if (b == NULL)
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494 return NULL;
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495 b->x[0] = y9;
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496 b->wds = 1;
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497
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498 if (nd <= 9)
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499 return b;
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500
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501 s += 9;
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502 for (i = 9; i < nd0; i++) {
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503 b = multadd(b, 10, *s++ - '0');
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504 if (b == NULL)
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505 return NULL;
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506 }
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507 s++;
53185
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508 for(; i < nd; i++) {
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509 b = multadd(b, 10, *s++ - '0');
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510 if (b == NULL)
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511 return NULL;
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512 }
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513 return b;
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514 }
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515
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516 /* count leading 0 bits in the 32-bit integer x. */
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517
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518 static int
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519 hi0bits(ULong x)
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520 {
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521 int k = 0;
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522
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523 if (!(x & 0xffff0000)) {
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524 k = 16;
97ae7a709c1d Issue #1580: use short float repr where possible.
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525 x <<= 16;
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526 }
97ae7a709c1d Issue #1580: use short float repr where possible.
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527 if (!(x & 0xff000000)) {
97ae7a709c1d Issue #1580: use short float repr where possible.
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528 k += 8;
97ae7a709c1d Issue #1580: use short float repr where possible.
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529 x <<= 8;
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Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
530 }
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Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
531 if (!(x & 0xf0000000)) {
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Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
532 k += 4;
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533 x <<= 4;
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parents:
diff changeset
534 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
535 if (!(x & 0xc0000000)) {
97ae7a709c1d Issue #1580: use short float repr where possible.
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diff changeset
536 k += 2;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
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537 x <<= 2;
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Mark Dickinson <dickinsm@gmail.com>
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538 }
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Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
539 if (!(x & 0x80000000)) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
540 k++;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
541 if (!(x & 0x40000000))
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Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
542 return 32;
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parents:
diff changeset
543 }
97ae7a709c1d Issue #1580: use short float repr where possible.
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parents:
diff changeset
544 return k;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
545 }
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Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
546
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Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
547 /* count trailing 0 bits in the 32-bit integer y, and shift y right by that
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parents:
diff changeset
548 number of bits. */
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parents:
diff changeset
549
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Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
550 static int
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parents:
diff changeset
551 lo0bits(ULong *y)
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parents:
diff changeset
552 {
97ae7a709c1d Issue #1580: use short float repr where possible.
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parents:
diff changeset
553 int k;
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Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
554 ULong x = *y;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
555
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
556 if (x & 7) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
557 if (x & 1)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
558 return 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
559 if (x & 2) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
560 *y = x >> 1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
561 return 1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
562 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
563 *y = x >> 2;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
564 return 2;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
565 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
566 k = 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
567 if (!(x & 0xffff)) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
568 k = 16;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
569 x >>= 16;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
570 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
571 if (!(x & 0xff)) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
572 k += 8;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
573 x >>= 8;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
574 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
575 if (!(x & 0xf)) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
576 k += 4;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
577 x >>= 4;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
578 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
579 if (!(x & 0x3)) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
580 k += 2;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
581 x >>= 2;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
582 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
583 if (!(x & 1)) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
584 k++;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
585 x >>= 1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
586 if (!x)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
587 return 32;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
588 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
589 *y = x;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
590 return k;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
591 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
592
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
593 /* convert a small nonnegative integer to a Bigint */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
594
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
595 static Bigint *
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
596 i2b(int i)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
597 {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
598 Bigint *b;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
599
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
600 b = Balloc(1);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
601 if (b == NULL)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
602 return NULL;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
603 b->x[0] = i;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
604 b->wds = 1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
605 return b;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
606 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
607
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
608 /* multiply two Bigints. Returns a new Bigint, or NULL on failure. Ignores
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
609 the signs of a and b. */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
610
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
611 static Bigint *
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
612 mult(Bigint *a, Bigint *b)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
613 {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
614 Bigint *c;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
615 int k, wa, wb, wc;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
616 ULong *x, *xa, *xae, *xb, *xbe, *xc, *xc0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
617 ULong y;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
618 #ifdef ULLong
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
619 ULLong carry, z;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
620 #else
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
621 ULong carry, z;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
622 ULong z2;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
623 #endif
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
624
58467
be12d3621519 Merged revisions 77691,77698,77713-77714 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58427
diff changeset
625 if ((!a->x[0] && a->wds == 1) || (!b->x[0] && b->wds == 1)) {
be12d3621519 Merged revisions 77691,77698,77713-77714 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58427
diff changeset
626 c = Balloc(0);
be12d3621519 Merged revisions 77691,77698,77713-77714 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58427
diff changeset
627 if (c == NULL)
be12d3621519 Merged revisions 77691,77698,77713-77714 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58427
diff changeset
628 return NULL;
be12d3621519 Merged revisions 77691,77698,77713-77714 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58427
diff changeset
629 c->wds = 1;
be12d3621519 Merged revisions 77691,77698,77713-77714 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58427
diff changeset
630 c->x[0] = 0;
be12d3621519 Merged revisions 77691,77698,77713-77714 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58427
diff changeset
631 return c;
be12d3621519 Merged revisions 77691,77698,77713-77714 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58427
diff changeset
632 }
be12d3621519 Merged revisions 77691,77698,77713-77714 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58427
diff changeset
633
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
634 if (a->wds < b->wds) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
635 c = a;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
636 a = b;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
637 b = c;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
638 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
639 k = a->k;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
640 wa = a->wds;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
641 wb = b->wds;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
642 wc = wa + wb;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
643 if (wc > a->maxwds)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
644 k++;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
645 c = Balloc(k);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
646 if (c == NULL)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
647 return NULL;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
648 for(x = c->x, xa = x + wc; x < xa; x++)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
649 *x = 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
650 xa = a->x;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
651 xae = xa + wa;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
652 xb = b->x;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
653 xbe = xb + wb;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
654 xc0 = c->x;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
655 #ifdef ULLong
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
656 for(; xb < xbe; xc0++) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
657 if ((y = *xb++)) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
658 x = xa;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
659 xc = xc0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
660 carry = 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
661 do {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
662 z = *x++ * (ULLong)y + *xc + carry;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
663 carry = z >> 32;
53207
fe99a562b708 Silence compiler warnings on VS8.0
Mark Dickinson <dickinsm@gmail.com>
parents: 53203
diff changeset
664 *xc++ = (ULong)(z & FFFFFFFF);
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
665 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
666 while(x < xae);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
667 *xc = (ULong)carry;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
668 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
669 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
670 #else
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
671 for(; xb < xbe; xb++, xc0++) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
672 if (y = *xb & 0xffff) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
673 x = xa;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
674 xc = xc0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
675 carry = 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
676 do {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
677 z = (*x & 0xffff) * y + (*xc & 0xffff) + carry;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
678 carry = z >> 16;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
679 z2 = (*x++ >> 16) * y + (*xc >> 16) + carry;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
680 carry = z2 >> 16;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
681 Storeinc(xc, z2, z);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
682 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
683 while(x < xae);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
684 *xc = carry;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
685 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
686 if (y = *xb >> 16) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
687 x = xa;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
688 xc = xc0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
689 carry = 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
690 z2 = *xc;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
691 do {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
692 z = (*x & 0xffff) * y + (*xc >> 16) + carry;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
693 carry = z >> 16;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
694 Storeinc(xc, z, z2);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
695 z2 = (*x++ >> 16) * y + (*xc & 0xffff) + carry;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
696 carry = z2 >> 16;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
697 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
698 while(x < xae);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
699 *xc = z2;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
700 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
701 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
702 #endif
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
703 for(xc0 = c->x, xc = xc0 + wc; wc > 0 && !*--xc; --wc) ;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
704 c->wds = wc;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
705 return c;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
706 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
707
58402
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diff changeset
708 #ifndef Py_USING_MEMORY_DEBUGGER
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diff changeset
709
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
710 /* p5s is a linked list of powers of 5 of the form 5**(2**i), i >= 2 */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
711
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
712 static Bigint *p5s;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
713
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
714 /* multiply the Bigint b by 5**k. Returns a pointer to the result, or NULL on
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
715 failure; if the returned pointer is distinct from b then the original
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
716 Bigint b will have been Bfree'd. Ignores the sign of b. */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
717
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
718 static Bigint *
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
719 pow5mult(Bigint *b, int k)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
720 {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
721 Bigint *b1, *p5, *p51;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
722 int i;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
723 static int p05[3] = { 5, 25, 125 };
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
724
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
725 if ((i = k & 3)) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
726 b = multadd(b, p05[i-1], 0);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
727 if (b == NULL)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
728 return NULL;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
729 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
730
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
731 if (!(k >>= 2))
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
732 return b;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
733 p5 = p5s;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
734 if (!p5) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
735 /* first time */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
736 p5 = i2b(625);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
737 if (p5 == NULL) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
738 Bfree(b);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
739 return NULL;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
740 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
741 p5s = p5;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
742 p5->next = 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
743 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
744 for(;;) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
745 if (k & 1) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
746 b1 = mult(b, p5);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
747 Bfree(b);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
748 b = b1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
749 if (b == NULL)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
750 return NULL;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
751 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
752 if (!(k >>= 1))
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
753 break;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
754 p51 = p5->next;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
755 if (!p51) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
756 p51 = mult(p5,p5);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
757 if (p51 == NULL) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
758 Bfree(b);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
759 return NULL;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
760 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
761 p51->next = 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
762 p5->next = p51;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
763 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
764 p5 = p51;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
765 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
766 return b;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
767 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
768
58402
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diff changeset
769 #else
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diff changeset
770
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parents: 58391
diff changeset
771 /* Version of pow5mult that doesn't cache powers of 5. Provided for
3e629471850a Merged revisions 77589 via svnmerge from
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parents: 58391
diff changeset
772 the benefit of memory debugging tools like Valgrind. */
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diff changeset
773
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parents: 58391
diff changeset
774 static Bigint *
3e629471850a Merged revisions 77589 via svnmerge from
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parents: 58391
diff changeset
775 pow5mult(Bigint *b, int k)
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parents: 58391
diff changeset
776 {
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diff changeset
777 Bigint *b1, *p5, *p51;
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parents: 58391
diff changeset
778 int i;
3e629471850a Merged revisions 77589 via svnmerge from
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parents: 58391
diff changeset
779 static int p05[3] = { 5, 25, 125 };
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parents: 58391
diff changeset
780
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parents: 58391
diff changeset
781 if ((i = k & 3)) {
3e629471850a Merged revisions 77589 via svnmerge from
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parents: 58391
diff changeset
782 b = multadd(b, p05[i-1], 0);
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parents: 58391
diff changeset
783 if (b == NULL)
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parents: 58391
diff changeset
784 return NULL;
3e629471850a Merged revisions 77589 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58391
diff changeset
785 }
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parents: 58391
diff changeset
786
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parents: 58391
diff changeset
787 if (!(k >>= 2))
3e629471850a Merged revisions 77589 via svnmerge from
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parents: 58391
diff changeset
788 return b;
3e629471850a Merged revisions 77589 via svnmerge from
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parents: 58391
diff changeset
789 p5 = i2b(625);
3e629471850a Merged revisions 77589 via svnmerge from
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parents: 58391
diff changeset
790 if (p5 == NULL) {
3e629471850a Merged revisions 77589 via svnmerge from
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parents: 58391
diff changeset
791 Bfree(b);
3e629471850a Merged revisions 77589 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58391
diff changeset
792 return NULL;
3e629471850a Merged revisions 77589 via svnmerge from
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parents: 58391
diff changeset
793 }
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parents: 58391
diff changeset
794
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Mark Dickinson <dickinsm@gmail.com>
parents: 58391
diff changeset
795 for(;;) {
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Mark Dickinson <dickinsm@gmail.com>
parents: 58391
diff changeset
796 if (k & 1) {
3e629471850a Merged revisions 77589 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58391
diff changeset
797 b1 = mult(b, p5);
3e629471850a Merged revisions 77589 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58391
diff changeset
798 Bfree(b);
3e629471850a Merged revisions 77589 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58391
diff changeset
799 b = b1;
3e629471850a Merged revisions 77589 via svnmerge from
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parents: 58391
diff changeset
800 if (b == NULL) {
3e629471850a Merged revisions 77589 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58391
diff changeset
801 Bfree(p5);
3e629471850a Merged revisions 77589 via svnmerge from
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parents: 58391
diff changeset
802 return NULL;
3e629471850a Merged revisions 77589 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58391
diff changeset
803 }
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Mark Dickinson <dickinsm@gmail.com>
parents: 58391
diff changeset
804 }
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Mark Dickinson <dickinsm@gmail.com>
parents: 58391
diff changeset
805 if (!(k >>= 1))
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parents: 58391
diff changeset
806 break;
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parents: 58391
diff changeset
807 p51 = mult(p5, p5);
3e629471850a Merged revisions 77589 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58391
diff changeset
808 Bfree(p5);
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Mark Dickinson <dickinsm@gmail.com>
parents: 58391
diff changeset
809 p5 = p51;
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Mark Dickinson <dickinsm@gmail.com>
parents: 58391
diff changeset
810 if (p5 == NULL) {
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parents: 58391
diff changeset
811 Bfree(b);
3e629471850a Merged revisions 77589 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58391
diff changeset
812 return NULL;
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parents: 58391
diff changeset
813 }
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parents: 58391
diff changeset
814 }
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parents: 58391
diff changeset
815 Bfree(p5);
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Mark Dickinson <dickinsm@gmail.com>
parents: 58391
diff changeset
816 return b;
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parents: 58391
diff changeset
817 }
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parents: 58391
diff changeset
818
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parents: 58391
diff changeset
819 #endif /* Py_USING_MEMORY_DEBUGGER */
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diff changeset
820
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
821 /* shift a Bigint b left by k bits. Return a pointer to the shifted result,
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
822 or NULL on failure. If the returned pointer is distinct from b then the
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
823 original b will have been Bfree'd. Ignores the sign of b. */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
824
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
825 static Bigint *
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
826 lshift(Bigint *b, int k)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
827 {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
828 int i, k1, n, n1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
829 Bigint *b1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
830 ULong *x, *x1, *xe, z;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
831
58467
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parents: 58427
diff changeset
832 if (!k || (!b->x[0] && b->wds == 1))
be12d3621519 Merged revisions 77691,77698,77713-77714 via svnmerge from
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parents: 58427
diff changeset
833 return b;
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parents: 58427
diff changeset
834
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
835 n = k >> 5;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
836 k1 = b->k;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
837 n1 = n + b->wds + 1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
838 for(i = b->maxwds; n1 > i; i <<= 1)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
839 k1++;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
840 b1 = Balloc(k1);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
841 if (b1 == NULL) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
842 Bfree(b);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
843 return NULL;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
844 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
845 x1 = b1->x;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
846 for(i = 0; i < n; i++)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
847 *x1++ = 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
848 x = b->x;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
849 xe = x + b->wds;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
850 if (k &= 0x1f) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
851 k1 = 32 - k;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
852 z = 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
853 do {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
854 *x1++ = *x << k | z;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
855 z = *x++ >> k1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
856 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
857 while(x < xe);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
858 if ((*x1 = z))
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
859 ++n1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
860 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
861 else do
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
862 *x1++ = *x++;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
863 while(x < xe);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
864 b1->wds = n1 - 1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
865 Bfree(b);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
866 return b1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
867 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
868
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
869 /* Do a three-way compare of a and b, returning -1 if a < b, 0 if a == b and
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
870 1 if a > b. Ignores signs of a and b. */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
871
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
872 static int
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
873 cmp(Bigint *a, Bigint *b)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
874 {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
875 ULong *xa, *xa0, *xb, *xb0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
876 int i, j;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
877
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
878 i = a->wds;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
879 j = b->wds;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
880 #ifdef DEBUG
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
881 if (i > 1 && !a->x[i-1])
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
882 Bug("cmp called with a->x[a->wds-1] == 0");
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
883 if (j > 1 && !b->x[j-1])
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
884 Bug("cmp called with b->x[b->wds-1] == 0");
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
885 #endif
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
886 if (i -= j)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
887 return i;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
888 xa0 = a->x;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
889 xa = xa0 + j;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
890 xb0 = b->x;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
891 xb = xb0 + j;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
892 for(;;) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
893 if (*--xa != *--xb)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
894 return *xa < *xb ? -1 : 1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
895 if (xa <= xa0)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
896 break;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
897 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
898 return 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
899 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
900
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
901 /* Take the difference of Bigints a and b, returning a new Bigint. Returns
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
902 NULL on failure. The signs of a and b are ignored, but the sign of the
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
903 result is set appropriately. */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
904
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
905 static Bigint *
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
906 diff(Bigint *a, Bigint *b)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
907 {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
908 Bigint *c;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
909 int i, wa, wb;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
910 ULong *xa, *xae, *xb, *xbe, *xc;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
911 #ifdef ULLong
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
912 ULLong borrow, y;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
913 #else
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
914 ULong borrow, y;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
915 ULong z;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
916 #endif
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
917
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
918 i = cmp(a,b);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
919 if (!i) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
920 c = Balloc(0);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
921 if (c == NULL)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
922 return NULL;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
923 c->wds = 1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
924 c->x[0] = 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
925 return c;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
926 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
927 if (i < 0) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
928 c = a;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
929 a = b;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
930 b = c;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
931 i = 1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
932 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
933 else
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
934 i = 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
935 c = Balloc(a->k);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
936 if (c == NULL)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
937 return NULL;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
938 c->sign = i;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
939 wa = a->wds;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
940 xa = a->x;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
941 xae = xa + wa;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
942 wb = b->wds;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
943 xb = b->x;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
944 xbe = xb + wb;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
945 xc = c->x;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
946 borrow = 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
947 #ifdef ULLong
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
948 do {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
949 y = (ULLong)*xa++ - *xb++ - borrow;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
950 borrow = y >> 32 & (ULong)1;
53207
fe99a562b708 Silence compiler warnings on VS8.0
Mark Dickinson <dickinsm@gmail.com>
parents: 53203
diff changeset
951 *xc++ = (ULong)(y & FFFFFFFF);
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
952 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
953 while(xb < xbe);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
954 while(xa < xae) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
955 y = *xa++ - borrow;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
956 borrow = y >> 32 & (ULong)1;
53207
fe99a562b708 Silence compiler warnings on VS8.0
Mark Dickinson <dickinsm@gmail.com>
parents: 53203
diff changeset
957 *xc++ = (ULong)(y & FFFFFFFF);
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
958 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
959 #else
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
960 do {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
961 y = (*xa & 0xffff) - (*xb & 0xffff) - borrow;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
962 borrow = (y & 0x10000) >> 16;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
963 z = (*xa++ >> 16) - (*xb++ >> 16) - borrow;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
964 borrow = (z & 0x10000) >> 16;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
965 Storeinc(xc, z, y);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
966 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
967 while(xb < xbe);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
968 while(xa < xae) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
969 y = (*xa & 0xffff) - borrow;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
970 borrow = (y & 0x10000) >> 16;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
971 z = (*xa++ >> 16) - borrow;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
972 borrow = (z & 0x10000) >> 16;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
973 Storeinc(xc, z, y);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
974 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
975 #endif
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
976 while(!*--xc)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
977 wa--;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
978 c->wds = wa;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
979 return c;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
980 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
981
58427
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
982 /* Given a positive normal double x, return the difference between x and the
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
983 next double up. Doesn't give correct results for subnormals. */
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
984
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
985 static double
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
986 ulp(U *x)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
987 {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
988 Long L;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
989 U u;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
990
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
991 L = (word0(x) & Exp_mask) - (P-1)*Exp_msk1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
992 word0(&u) = L;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
993 word1(&u) = 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
994 return dval(&u);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
995 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
996
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
997 /* Convert a Bigint to a double plus an exponent */
97ae7a709c1d Issue #1580: use short float repr where possible.
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998
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diff changeset
999 static double
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diff changeset
1000 b2d(Bigint *a, int *e)
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1001 {
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1002 ULong *xa, *xa0, w, y, z;
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1003 int k;
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1004 U d;
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diff changeset
1005
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1006 xa0 = a->x;
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diff changeset
1007 xa = xa0 + a->wds;
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1008 y = *--xa;
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parents:
diff changeset
1009 #ifdef DEBUG
97ae7a709c1d Issue #1580: use short float repr where possible.
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parents:
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1010 if (!y) Bug("zero y in b2d");
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Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1011 #endif
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Mark Dickinson <dickinsm@gmail.com>
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1012 k = hi0bits(y);
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Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1013 *e = 32 - k;
97ae7a709c1d Issue #1580: use short float repr where possible.
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parents:
diff changeset
1014 if (k < Ebits) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1015 word0(&d) = Exp_1 | y >> (Ebits - k);
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parents:
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1016 w = xa > xa0 ? *--xa : 0;
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Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1017 word1(&d) = y << ((32-Ebits) + k) | w >> (Ebits - k);
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Mark Dickinson <dickinsm@gmail.com>
parents:
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1018 goto ret_d;
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parents:
diff changeset
1019 }
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diff changeset
1020 z = xa > xa0 ? *--xa : 0;
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Mark Dickinson <dickinsm@gmail.com>
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diff changeset
1021 if (k -= Ebits) {
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Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1022 word0(&d) = Exp_1 | y << k | z >> (32 - k);
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parents:
diff changeset
1023 y = xa > xa0 ? *--xa : 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
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1024 word1(&d) = z << k | y >> (32 - k);
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Mark Dickinson <dickinsm@gmail.com>
parents:
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1025 }
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parents:
diff changeset
1026 else {
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parents:
diff changeset
1027 word0(&d) = Exp_1 | y;
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Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1028 word1(&d) = z;
97ae7a709c1d Issue #1580: use short float repr where possible.
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parents:
diff changeset
1029 }
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parents:
diff changeset
1030 ret_d:
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Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1031 return dval(&d);
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parents:
diff changeset
1032 }
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1033
58467
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1034 /* Convert a scaled double to a Bigint plus an exponent. Similar to d2b,
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1035 except that it accepts the scale parameter used in _Py_dg_strtod (which
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diff changeset
1036 should be either 0 or 2*P), and the normalization for the return value is
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1037 different (see below). On input, d should be finite and nonnegative, and d
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1038 / 2**scale should be exactly representable as an IEEE 754 double.
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1039
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1040 Returns a Bigint b and an integer e such that
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diff changeset
1041
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1042 dval(d) / 2**scale = b * 2**e.
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1043
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1044 Unlike d2b, b is not necessarily odd: b and e are normalized so
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1045 that either 2**(P-1) <= b < 2**P and e >= Etiny, or b < 2**P
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diff changeset
1046 and e == Etiny. This applies equally to an input of 0.0: in that
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diff changeset
1047 case the return values are b = 0 and e = Etiny.
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1048
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1049 The above normalization ensures that for all possible inputs d,
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1050 2**e gives ulp(d/2**scale).
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1051
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1052 Returns NULL on failure.
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1053 */
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1054
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1055 static Bigint *
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1056 sd2b(U *d, int scale, int *e)
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diff changeset
1057 {
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1058 Bigint *b;
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1059
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1060 b = Balloc(1);
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diff changeset
1061 if (b == NULL)
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1062 return NULL;
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diff changeset
1063
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1064 /* First construct b and e assuming that scale == 0. */
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diff changeset
1065 b->wds = 2;
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diff changeset
1066 b->x[0] = word1(d);
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1067 b->x[1] = word0(d) & Frac_mask;
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1068 *e = Etiny - 1 + (int)((word0(d) & Exp_mask) >> Exp_shift);
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diff changeset
1069 if (*e < Etiny)
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diff changeset
1070 *e = Etiny;
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diff changeset
1071 else
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1072 b->x[1] |= Exp_msk1;
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diff changeset
1073
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1074 /* Now adjust for scale, provided that b != 0. */
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diff changeset
1075 if (scale && (b->x[0] || b->x[1])) {
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diff changeset
1076 *e -= scale;
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diff changeset
1077 if (*e < Etiny) {
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1078 scale = Etiny - *e;
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1079 *e = Etiny;
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1080 /* We can't shift more than P-1 bits without shifting out a 1. */
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diff changeset
1081 assert(0 < scale && scale <= P - 1);
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1082 if (scale >= 32) {
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1083 /* The bits shifted out should all be zero. */
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1084 assert(b->x[0] == 0);
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1085 b->x[0] = b->x[1];
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1086 b->x[1] = 0;
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diff changeset
1087 scale -= 32;
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1088 }
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1089 if (scale) {
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1090 /* The bits shifted out should all be zero. */
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1091 assert(b->x[0] << (32 - scale) == 0);
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diff changeset
1092 b->x[0] = (b->x[0] >> scale) | (b->x[1] << (32 - scale));
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1093 b->x[1] >>= scale;
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1094 }
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1095 }
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diff changeset
1096 }
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1097 /* Ensure b is normalized. */
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diff changeset
1098 if (!b->x[1])
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1099 b->wds = 1;
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diff changeset
1100
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1101 return b;
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1102 }
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1103
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1104 /* Convert a double to a Bigint plus an exponent. Return NULL on failure.
97ae7a709c1d Issue #1580: use short float repr where possible.
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parents:
diff changeset
1105
97ae7a709c1d Issue #1580: use short float repr where possible.
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parents:
diff changeset
1106 Given a finite nonzero double d, return an odd Bigint b and exponent *e
97ae7a709c1d Issue #1580: use short float repr where possible.
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parents:
diff changeset
1107 such that fabs(d) = b * 2**e. On return, *bbits gives the number of
58154
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diff changeset
1108 significant bits of b; that is, 2**(*bbits-1) <= b < 2**(*bbits).
53185
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diff changeset
1109
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parents:
diff changeset
1110 If d is zero, then b == 0, *e == -1010, *bbits = 0.
97ae7a709c1d Issue #1580: use short float repr where possible.
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parents:
diff changeset
1111 */
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parents:
diff changeset
1112
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parents:
diff changeset
1113 static Bigint *
97ae7a709c1d Issue #1580: use short float repr where possible.
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parents:
diff changeset
1114 d2b(U *d, int *e, int *bits)
97ae7a709c1d Issue #1580: use short float repr where possible.
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parents:
diff changeset
1115 {
97ae7a709c1d Issue #1580: use short float repr where possible.
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parents:
diff changeset
1116 Bigint *b;
97ae7a709c1d Issue #1580: use short float repr where possible.
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parents:
diff changeset
1117 int de, k;
97ae7a709c1d Issue #1580: use short float repr where possible.
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parents:
diff changeset
1118 ULong *x, y, z;
97ae7a709c1d Issue #1580: use short float repr where possible.
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diff changeset
1119 int i;
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parents:
diff changeset
1120
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diff changeset
1121 b = Balloc(1);
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diff changeset
1122 if (b == NULL)
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diff changeset
1123 return NULL;
97ae7a709c1d Issue #1580: use short float repr where possible.
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parents:
diff changeset
1124 x = b->x;
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parents:
diff changeset
1125
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diff changeset
1126 z = word0(d) & Frac_mask;
97ae7a709c1d Issue #1580: use short float repr where possible.
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parents:
diff changeset
1127 word0(d) &= 0x7fffffff; /* clear sign bit, which we ignore */
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parents:
diff changeset
1128 if ((de = (int)(word0(d) >> Exp_shift)))
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1129 z |= Exp_msk1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1130 if ((y = word1(d))) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1131 if ((k = lo0bits(&y))) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1132 x[0] = y | z << (32 - k);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1133 z >>= k;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1134 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1135 else
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1136 x[0] = y;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1137 i =
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1138 b->wds = (x[1] = z) ? 2 : 1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1139 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1140 else {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1141 k = lo0bits(&z);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1142 x[0] = z;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1143 i =
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1144 b->wds = 1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1145 k += 32;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1146 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1147 if (de) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1148 *e = de - Bias - (P-1) + k;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1149 *bits = P - k;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1150 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1151 else {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1152 *e = de - Bias - (P-1) + 1 + k;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1153 *bits = 32*i - hi0bits(x[i-1]);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1154 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1155 return b;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1156 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1157
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1158 /* Compute the ratio of two Bigints, as a double. The result may have an
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1159 error of up to 2.5 ulps. */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1160
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1161 static double
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1162 ratio(Bigint *a, Bigint *b)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1163 {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1164 U da, db;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1165 int k, ka, kb;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1166
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1167 dval(&da) = b2d(a, &ka);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1168 dval(&db) = b2d(b, &kb);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1169 k = ka - kb + 32*(a->wds - b->wds);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1170 if (k > 0)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1171 word0(&da) += k*Exp_msk1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1172 else {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1173 k = -k;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1174 word0(&db) += k*Exp_msk1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1175 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1176 return dval(&da) / dval(&db);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1177 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1178
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1179 static const double
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1180 tens[] = {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1181 1e0, 1e1, 1e2, 1e3, 1e4, 1e5, 1e6, 1e7, 1e8, 1e9,
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1182 1e10, 1e11, 1e12, 1e13, 1e14, 1e15, 1e16, 1e17, 1e18, 1e19,
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1183 1e20, 1e21, 1e22
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1184 };
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1186 static const double
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1187 bigtens[] = { 1e16, 1e32, 1e64, 1e128, 1e256 };
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1188 static const double tinytens[] = { 1e-16, 1e-32, 1e-64, 1e-128,
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1189 9007199254740992.*9007199254740992.e-256
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1190 /* = 2^106 * 1e-256 */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1191 };
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1192 /* The factor of 2^53 in tinytens[4] helps us avoid setting the underflow */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1193 /* flag unnecessarily. It leads to a song and dance at the end of strtod. */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1194 #define Scale_Bit 0x10
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1195 #define n_bigtens 5
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1196
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1197 #define ULbits 32
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1198 #define kshift 5
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1199 #define kmask 31
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1200
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1201
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1202 static int
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1203 dshift(Bigint *b, int p2)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1204 {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1205 int rv = hi0bits(b->x[b->wds-1]) - 4;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1206 if (p2 > 0)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1207 rv -= p2;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1208 return rv & kmask;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1209 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1210
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1211 /* special case of Bigint division. The quotient is always in the range 0 <=
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1212 quotient < 10, and on entry the divisor S is normalized so that its top 4
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1213 bits (28--31) are zero and bit 27 is set. */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1214
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1215 static int
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1216 quorem(Bigint *b, Bigint *S)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1217 {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1218 int n;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1219 ULong *bx, *bxe, q, *sx, *sxe;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1220 #ifdef ULLong
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1221 ULLong borrow, carry, y, ys;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1222 #else
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1223 ULong borrow, carry, y, ys;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1224 ULong si, z, zs;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1225 #endif
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1226
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1227 n = S->wds;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1228 #ifdef DEBUG
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1229 /*debug*/ if (b->wds > n)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1230 /*debug*/ Bug("oversize b in quorem");
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1231 #endif
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1232 if (b->wds < n)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1233 return 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1234 sx = S->x;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1235 sxe = sx + --n;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1236 bx = b->x;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1237 bxe = bx + n;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1238 q = *bxe / (*sxe + 1); /* ensure q <= true quotient */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1239 #ifdef DEBUG
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1240 /*debug*/ if (q > 9)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1241 /*debug*/ Bug("oversized quotient in quorem");
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1242 #endif
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1243 if (q) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1244 borrow = 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1245 carry = 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1246 do {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1247 #ifdef ULLong
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1248 ys = *sx++ * (ULLong)q + carry;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1249 carry = ys >> 32;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1250 y = *bx - (ys & FFFFFFFF) - borrow;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1251 borrow = y >> 32 & (ULong)1;
53207
fe99a562b708 Silence compiler warnings on VS8.0
Mark Dickinson <dickinsm@gmail.com>
parents: 53203
diff changeset
1252 *bx++ = (ULong)(y & FFFFFFFF);
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1253 #else
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1254 si = *sx++;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1255 ys = (si & 0xffff) * q + carry;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1256 zs = (si >> 16) * q + (ys >> 16);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1257 carry = zs >> 16;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1258 y = (*bx & 0xffff) - (ys & 0xffff) - borrow;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1259 borrow = (y & 0x10000) >> 16;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1260 z = (*bx >> 16) - (zs & 0xffff) - borrow;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1261 borrow = (z & 0x10000) >> 16;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1262 Storeinc(bx, z, y);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1263 #endif
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1264 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1265 while(sx <= sxe);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1266 if (!*bxe) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1267 bx = b->x;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1268 while(--bxe > bx && !*bxe)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1269 --n;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1270 b->wds = n;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1271 }
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parents:
diff changeset
1272 }
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diff changeset
1273 if (cmp(b, S) >= 0) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1274 q++;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1275 borrow = 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1276 carry = 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1277 bx = b->x;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1278 sx = S->x;
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Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1279 do {
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Mark Dickinson <dickinsm@gmail.com>
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1280 #ifdef ULLong
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1281 ys = *sx++ + carry;
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Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1282 carry = ys >> 32;
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Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1283 y = *bx - (ys & FFFFFFFF) - borrow;
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Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1284 borrow = y >> 32 & (ULong)1;
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1285 *bx++ = (ULong)(y & FFFFFFFF);
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Mark Dickinson <dickinsm@gmail.com>
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1286 #else
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diff changeset
1287 si = *sx++;
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1288 ys = (si & 0xffff) + carry;
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Mark Dickinson <dickinsm@gmail.com>
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diff changeset
1289 zs = (si >> 16) + (ys >> 16);
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Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1290 carry = zs >> 16;
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parents:
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1291 y = (*bx & 0xffff) - (ys & 0xffff) - borrow;
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Mark Dickinson <dickinsm@gmail.com>
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1292 borrow = (y & 0x10000) >> 16;
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Mark Dickinson <dickinsm@gmail.com>
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diff changeset
1293 z = (*bx >> 16) - (zs & 0xffff) - borrow;
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Mark Dickinson <dickinsm@gmail.com>
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1294 borrow = (z & 0x10000) >> 16;
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Mark Dickinson <dickinsm@gmail.com>
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1295 Storeinc(bx, z, y);
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Mark Dickinson <dickinsm@gmail.com>
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1296 #endif
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diff changeset
1297 }
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1298 while(sx <= sxe);
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Mark Dickinson <dickinsm@gmail.com>
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1299 bx = b->x;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
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1300 bxe = bx + n;
97ae7a709c1d Issue #1580: use short float repr where possible.
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1301 if (!*bxe) {
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Mark Dickinson <dickinsm@gmail.com>
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diff changeset
1302 while(--bxe > bx && !*bxe)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1303 --n;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
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1304 b->wds = n;
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Mark Dickinson <dickinsm@gmail.com>
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diff changeset
1305 }
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parents:
diff changeset
1306 }
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1307 return q;
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parents:
diff changeset
1308 }
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diff changeset
1309
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1310 /* sulp(x) is a version of ulp(x) that takes bc.scale into account.
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1311
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1312 Assuming that x is finite and nonnegative (positive zero is fine
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1313 here) and x / 2^bc.scale is exactly representable as a double,
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diff changeset
1314 sulp(x) is equivalent to 2^bc.scale * ulp(x / 2^bc.scale). */
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1315
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1316 static double
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1317 sulp(U *x, BCinfo *bc)
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1318 {
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diff changeset
1319 U u;
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1320
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1321 if (bc->scale && 2*P + 1 > (int)((word0(x) & Exp_mask) >> Exp_shift)) {
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1322 /* rv/2^bc->scale is subnormal */
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1323 word0(&u) = (P+2)*Exp_msk1;
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1324 word1(&u) = 0;
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1325 return u.d;
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1326 }
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1327 else {
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1328 assert(word0(x) || word1(x)); /* x != 0.0 */
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1329 return ulp(x);
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1330 }
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1331 }
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1332
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1333 /* The bigcomp function handles some hard cases for strtod, for inputs
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diff changeset
1334 with more than STRTOD_DIGLIM digits. It's called once an initial
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diff changeset
1335 estimate for the double corresponding to the input string has
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1336 already been obtained by the code in _Py_dg_strtod.
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diff changeset
1337
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1338 The bigcomp function is only called after _Py_dg_strtod has found a
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diff changeset
1339 double value rv such that either rv or rv + 1ulp represents the
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diff changeset
1340 correctly rounded value corresponding to the original string. It
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diff changeset
1341 determines which of these two values is the correct one by
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diff changeset
1342 computing the decimal digits of rv + 0.5ulp and comparing them with
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1343 the corresponding digits of s0.
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diff changeset
1344
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diff changeset
1345 In the following, write dv for the absolute value of the number represented
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1346 by the input string.
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diff changeset
1347
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1348 Inputs:
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diff changeset
1349
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diff changeset
1350 s0 points to the first significant digit of the input string.
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diff changeset
1351
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diff changeset
1352 rv is a (possibly scaled) estimate for the closest double value to the
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diff changeset
1353 value represented by the original input to _Py_dg_strtod. If
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diff changeset
1354 bc->scale is nonzero, then rv/2^(bc->scale) is the approximation to
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1355 the input value.
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diff changeset
1356
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diff changeset
1357 bc is a struct containing information gathered during the parsing and
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diff changeset
1358 estimation steps of _Py_dg_strtod. Description of fields follows:
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diff changeset
1359
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diff changeset
1360 bc->e0 gives the exponent of the input value, such that dv = (integer
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1361 given by the bd->nd digits of s0) * 10**e0
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diff changeset
1362
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1363 bc->nd gives the total number of significant digits of s0. It will
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1364 be at least 1.
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1365
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1366 bc->nd0 gives the number of significant digits of s0 before the
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1367 decimal separator. If there's no decimal separator, bc->nd0 ==
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1368 bc->nd.
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diff changeset
1369
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1370 bc->scale is the value used to scale rv to avoid doing arithmetic with
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1371 subnormal values. It's either 0 or 2*P (=106).
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diff changeset
1372
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1373 Outputs:
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diff changeset
1374
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1375 On successful exit, rv/2^(bc->scale) is the closest double to dv.
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diff changeset
1376
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1377 Returns 0 on success, -1 on failure (e.g., due to a failed malloc call). */
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1378
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diff changeset
1379 static int
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diff changeset
1380 bigcomp(U *rv, const char *s0, BCinfo *bc)
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diff changeset
1381 {
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1382 Bigint *b, *d;
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1383 int b2, d2, dd, i, nd, nd0, odd, p2, p5;
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1384
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1385 dd = 0; /* silence compiler warning about possibly unused variable */
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diff changeset
1386 nd = bc->nd;
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1387 nd0 = bc->nd0;
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1388 p5 = nd + bc->e0;
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1389 b = sd2b(rv, bc->scale, &p2);
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1390 if (b == NULL)
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1391 return -1;
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1392
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parents: 58279
diff changeset
1393 /* record whether the lsb of rv/2^(bc->scale) is odd: in the exact halfway
ce11c1270b69 Merged revisions 77477-77478,77481-77483,77490-77493 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58279
diff changeset
1394 case, this is used for round to even. */
58467
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Mark Dickinson <dickinsm@gmail.com>
parents: 58427
diff changeset
1395 odd = b->x[0] & 1;
be12d3621519 Merged revisions 77691,77698,77713-77714 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58427
diff changeset
1396
be12d3621519 Merged revisions 77691,77698,77713-77714 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58427
diff changeset
1397 /* left shift b by 1 bit and or a 1 into the least significant bit;
be12d3621519 Merged revisions 77691,77698,77713-77714 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58427
diff changeset
1398 this gives us b * 2**p2 = rv/2^(bc->scale) + 0.5 ulp. */
be12d3621519 Merged revisions 77691,77698,77713-77714 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58427
diff changeset
1399 b = lshift(b, 1);
be12d3621519 Merged revisions 77691,77698,77713-77714 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58427
diff changeset
1400 if (b == NULL)
be12d3621519 Merged revisions 77691,77698,77713-77714 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58427
diff changeset
1401 return -1;
58320
ce11c1270b69 Merged revisions 77477-77478,77481-77483,77490-77493 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58279
diff changeset
1402 b->x[0] |= 1;
58467
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Mark Dickinson <dickinsm@gmail.com>
parents: 58427
diff changeset
1403 p2--;
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Mark Dickinson <dickinsm@gmail.com>
parents: 58279
diff changeset
1404
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Mark Dickinson <dickinsm@gmail.com>
parents: 58427
diff changeset
1405 p2 -= p5;
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1406 d = i2b(1);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1407 if (d == NULL) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1408 Bfree(b);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1409 return -1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1410 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1411 /* Arrange for convenient computation of quotients:
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1412 * shift left if necessary so divisor has 4 leading 0 bits.
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1413 */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1414 if (p5 > 0) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1415 d = pow5mult(d, p5);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1416 if (d == NULL) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1417 Bfree(b);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1418 return -1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1419 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1420 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1421 else if (p5 < 0) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1422 b = pow5mult(b, -p5);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1423 if (b == NULL) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1424 Bfree(d);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1425 return -1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1426 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1427 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1428 if (p2 > 0) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1429 b2 = p2;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1430 d2 = 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1431 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1432 else {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1433 b2 = 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1434 d2 = -p2;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1435 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1436 i = dshift(d, d2);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1437 if ((b2 += i) > 0) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1438 b = lshift(b, b2);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1439 if (b == NULL) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1440 Bfree(d);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1441 return -1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1442 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1443 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1444 if ((d2 += i) > 0) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1445 d = lshift(d, d2);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1446 if (d == NULL) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1447 Bfree(b);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1448 return -1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1449 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1450 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1451
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1452 /* Compare s0 with b/d: set dd to -1, 0, or 1 according as s0 < b/d, s0 ==
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1453 * b/d, or s0 > b/d. Here the digits of s0 are thought of as representing
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
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parents: 58402
diff changeset
1454 * a number in the range [0.1, 1). */
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parents: 58402
diff changeset
1455 if (cmp(b, d) >= 0)
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
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parents: 58402
diff changeset
1456 /* b/d >= 1 */
58279
c32d3b08fcdc Merged revisions 77410,77421,77450-77451 via svnmerge from
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parents: 58154
diff changeset
1457 dd = -1;
58427
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diff changeset
1458 else {
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
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parents: 58402
diff changeset
1459 i = 0;
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1460 for(;;) {
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1461 b = multadd(b, 10, 0);
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1462 if (b == NULL) {
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1463 Bfree(d);
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1464 return -1;
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1465 }
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1466 dd = s0[i < nd0 ? i : i+1] - '0' - quorem(b, d);
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1467 i++;
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1468
58427
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diff changeset
1469 if (dd)
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
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parents: 58402
diff changeset
1470 break;
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1471 if (!b->x[0] && b->wds == 1) {
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1472 /* b/d == 0 */
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1473 dd = i < nd;
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1474 break;
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1475 }
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1476 if (!(i < nd)) {
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1477 /* b/d != 0, but digits of s0 exhausted */
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1478 dd = -1;
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1479 break;
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
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parents: 58402
diff changeset
1480 }
53185
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Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1481 }
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parents: 58279
diff changeset
1482 }
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1483 Bfree(b);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1484 Bfree(d);
58320
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parents: 58279
diff changeset
1485 if (dd > 0 || (dd == 0 && odd))
ce11c1270b69 Merged revisions 77477-77478,77481-77483,77490-77493 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58279
diff changeset
1486 dval(rv) += sulp(rv, bc);
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1487 return 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1488 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1489
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1490 double
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1491 _Py_dg_strtod(const char *s00, char **se)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1492 {
58467
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parents: 58427
diff changeset
1493 int bb2, bb5, bbe, bd2, bd5, bs2, c, dsign, e, e1, error;
be12d3621519 Merged revisions 77691,77698,77713-77714 via svnmerge from
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parents: 58427
diff changeset
1494 int esign, i, j, k, lz, nd, nd0, odd, sign;
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1495 const char *s, *s0, *s1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1496 double aadj, aadj1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1497 U aadj2, adj, rv, rv0;
58427
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parents: 58402
diff changeset
1498 ULong y, z, abs_exp;
58360
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
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parents: 58320
diff changeset
1499 Long L;
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1500 BCinfo bc;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1501 Bigint *bb, *bb1, *bd, *bd0, *bs, *delta;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1502
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1503 dval(&rv) = 0.;
58427
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diff changeset
1504
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
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parents: 58402
diff changeset
1505 /* Start parsing. */
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1506 c = *(s = s00);
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1507
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
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parents: 58402
diff changeset
1508 /* Parse optional sign, if present. */
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1509 sign = 0;
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1510 switch (c) {
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1511 case '-':
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1512 sign = 1;
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1513 /* no break */
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1514 case '+':
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1515 c = *++s;
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1516 }
58427
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diff changeset
1517
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1518 /* Skip leading zeros: lz is true iff there were leading zeros. */
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1519 s1 = s;
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1520 while (c == '0')
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1521 c = *++s;
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1522 lz = s != s1;
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Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1523
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1524 /* Point s0 at the first nonzero digit (if any). nd0 will be the position
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1525 of the point relative to s0. nd will be the total number of digits
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Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1526 ignoring leading zeros. */
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Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1527 s0 = s1 = s;
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Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1528 while ('0' <= c && c <= '9')
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1529 c = *++s;
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1530 nd0 = nd = s - s1;
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Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1531
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Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1532 /* Parse decimal point and following digits. */
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1533 if (c == '.') {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1534 c = *++s;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1535 if (!nd) {
58427
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Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1536 s1 = s;
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1537 while (c == '0')
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1538 c = *++s;
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1539 lz = lz || s != s1;
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Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1540 nd0 -= s - s1;
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1541 s0 = s;
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1542 }
58427
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Mark Dickinson <dickinsm@gmail.com>
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diff changeset
1543 s1 = s;
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Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1544 while ('0' <= c && c <= '9')
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Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1545 c = *++s;
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Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1546 nd += s - s1;
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1547 }
58427
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diff changeset
1548
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Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1549 /* Now lz is true if and only if there were leading zero digits, and nd
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Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1550 gives the total number of digits ignoring leading zeros. A valid input
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1551 must have at least one digit. */
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parents: 58402
diff changeset
1552 if (!nd && !lz) {
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Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1553 if (se)
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Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1554 *se = (char *)s00;
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Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1555 goto parse_error;
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Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1556 }
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parents: 58402
diff changeset
1557
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diff changeset
1558 /* Parse exponent. */
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1559 e = 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1560 if (c == 'e' || c == 'E') {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1561 s00 = s;
58427
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Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1562 c = *++s;
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Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1563
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Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1564 /* Exponent sign. */
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1565 esign = 0;
58427
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Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1566 switch (c) {
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1567 case '-':
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1568 esign = 1;
58427
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Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1569 /* no break */
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1570 case '+':
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1571 c = *++s;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1572 }
58427
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diff changeset
1573
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parents: 58402
diff changeset
1574 /* Skip zeros. lz is true iff there are leading zeros. */
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Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1575 s1 = s;
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1576 while (c == '0')
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1577 c = *++s;
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1578 lz = s != s1;
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1579
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Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1580 /* Get absolute value of the exponent. */
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1581 s1 = s;
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1582 abs_exp = 0;
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1583 while ('0' <= c && c <= '9') {
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1584 abs_exp = 10*abs_exp + (c - '0');
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1585 c = *++s;
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1586 }
58427
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diff changeset
1587
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Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1588 /* abs_exp will be correct modulo 2**32. But 10**9 < 2**32, so if
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1589 there are at most 9 significant exponent digits then overflow is
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1590 impossible. */
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1591 if (s - s1 > 9 || abs_exp > MAX_ABS_EXP)
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1592 e = (int)MAX_ABS_EXP;
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1593 else
58427
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
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diff changeset
1594 e = (int)abs_exp;
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1595 if (esign)
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1596 e = -e;
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1597
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1598 /* A valid exponent must have at least one digit. */
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1599 if (s == s1 && !lz)
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1600 s = s00;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1601 }
58427
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
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parents: 58402
diff changeset
1602
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1603 /* Adjust exponent to take into account position of the point. */
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1604 e -= nd - nd0;
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1605 if (nd0 <= 0)
58360
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58320
diff changeset
1606 nd0 = nd;
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
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parents: 58320
diff changeset
1607
58427
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parents: 58402
diff changeset
1608 /* Finished parsing. Set se to indicate how far we parsed */
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Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1609 if (se)
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Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1610 *se = (char *)s;
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parents: 58402
diff changeset
1611
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parents: 58402
diff changeset
1612 /* If all digits were zero, exit with return value +-0.0. Otherwise,
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
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parents: 58402
diff changeset
1613 strip trailing zeros: scan back until we hit a nonzero digit. */
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Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1614 if (!nd)
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1615 goto ret;
58360
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
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parents: 58320
diff changeset
1616 for (i = nd; i > 0; ) {
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58320
diff changeset
1617 --i;
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
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parents: 58320
diff changeset
1618 if (s0[i < nd0 ? i : i+1] != '0') {
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58320
diff changeset
1619 ++i;
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58320
diff changeset
1620 break;
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
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parents: 58320
diff changeset
1621 }
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
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parents: 58320
diff changeset
1622 }
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
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parents: 58320
diff changeset
1623 e += nd - i;
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
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parents: 58320
diff changeset
1624 nd = i;
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
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parents: 58320
diff changeset
1625 if (nd0 > nd)
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
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parents: 58320
diff changeset
1626 nd0 = nd;
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1627
58427
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diff changeset
1628 /* Summary of parsing results. After parsing, and dealing with zero
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1629 * inputs, we have values s0, nd0, nd, e, sign, where:
58360
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
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parents: 58320
diff changeset
1630 *
58427
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parents: 58402
diff changeset
1631 * - s0 points to the first significant digit of the input string
58360
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
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parents: 58320
diff changeset
1632 *
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
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parents: 58320
diff changeset
1633 * - nd is the total number of significant digits (here, and
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
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parents: 58320
diff changeset
1634 * below, 'significant digits' means the set of digits of the
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
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parents: 58320
diff changeset
1635 * significand of the input that remain after ignoring leading
58427
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
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parents: 58402
diff changeset
1636 * and trailing zeros).
58360
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
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parents: 58320
diff changeset
1637 *
58427
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diff changeset
1638 * - nd0 indicates the position of the decimal point, if present; it
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
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parents: 58402
diff changeset
1639 * satisfies 1 <= nd0 <= nd. The nd significant digits are in
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1640 * s0[0:nd0] and s0[nd0+1:nd+1] using the usual Python half-open slice
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
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parents: 58402
diff changeset
1641 * notation. (If nd0 < nd, then s0[nd0] contains a '.' character; if
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
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parents: 58402
diff changeset
1642 * nd0 == nd, then s0[nd0] could be any non-digit character.)
58360
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diff changeset
1643 *
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
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parents: 58320
diff changeset
1644 * - e is the adjusted exponent: the absolute value of the number
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parents: 58320
diff changeset
1645 * represented by the original input string is n * 10**e, where
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
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parents: 58320
diff changeset
1646 * n is the integer represented by the concatenation of
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parents: 58320
diff changeset
1647 * s0[0:nd0] and s0[nd0+1:nd+1]
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58320
diff changeset
1648 *
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parents: 58320
diff changeset
1649 * - sign gives the sign of the input: 1 for negative, 0 for positive
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Mark Dickinson <dickinsm@gmail.com>
parents: 58320
diff changeset
1650 *
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
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parents: 58320
diff changeset
1651 * - the first and last significant digits are nonzero
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58320
diff changeset
1652 */
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58320
diff changeset
1653
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58320
diff changeset
1654 /* put first DBL_DIG+1 digits into integer y and z.
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58320
diff changeset
1655 *
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58320
diff changeset
1656 * - y contains the value represented by the first min(9, nd)
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58320
diff changeset
1657 * significant digits
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58320
diff changeset
1658 *
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58320
diff changeset
1659 * - if nd > 9, z contains the value represented by significant digits
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58320
diff changeset
1660 * with indices in [9, min(16, nd)). So y * 10**(min(16, nd) - 9) + z
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58320
diff changeset
1661 * gives the value represented by the first min(16, nd) sig. digits.
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58320
diff changeset
1662 */
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58320
diff changeset
1663
58427
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1664 bc.e0 = e1 = e;
58360
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58320
diff changeset
1665 y = z = 0;
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58320
diff changeset
1666 for (i = 0; i < nd; i++) {
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58320
diff changeset
1667 if (i < 9)
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58320
diff changeset
1668 y = 10*y + s0[i < nd0 ? i : i+1] - '0';
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58320
diff changeset
1669 else if (i < DBL_DIG+1)
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58320
diff changeset
1670 z = 10*z + s0[i < nd0 ? i : i+1] - '0';
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58320
diff changeset
1671 else
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58320
diff changeset
1672 break;
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58320
diff changeset
1673 }
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58320
diff changeset
1674
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1675 k = nd < DBL_DIG + 1 ? nd : DBL_DIG + 1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1676 dval(&rv) = y;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1677 if (k > 9) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1678 dval(&rv) = tens[k - 9] * dval(&rv) + z;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1679 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1680 bd0 = 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1681 if (nd <= DBL_DIG
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1682 && Flt_Rounds == 1
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1683 ) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1684 if (!e)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1685 goto ret;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1686 if (e > 0) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1687 if (e <= Ten_pmax) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1688 dval(&rv) *= tens[e];
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1689 goto ret;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1690 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1691 i = DBL_DIG - nd;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1692 if (e <= Ten_pmax + i) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1693 /* A fancier test would sometimes let us do
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1694 * this for larger i values.
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1695 */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1696 e -= i;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1697 dval(&rv) *= tens[i];
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1698 dval(&rv) *= tens[e];
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1699 goto ret;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1700 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1701 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1702 else if (e >= -Ten_pmax) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1703 dval(&rv) /= tens[-e];
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1704 goto ret;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1705 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1706 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1707 e1 += nd - k;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1708
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1709 bc.scale = 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1710
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1711 /* Get starting approximation = rv * 10**e1 */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1712
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1713 if (e1 > 0) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1714 if ((i = e1 & 15))
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1715 dval(&rv) *= tens[i];
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1716 if (e1 &= ~15) {
58427
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1717 if (e1 > DBL_MAX_10_EXP)
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1718 goto ovfl;
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1719 e1 >>= 4;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1720 for(j = 0; e1 > 1; j++, e1 >>= 1)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1721 if (e1 & 1)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1722 dval(&rv) *= bigtens[j];
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1723 /* The last multiplication could overflow. */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1724 word0(&rv) -= P*Exp_msk1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1725 dval(&rv) *= bigtens[j];
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1726 if ((z = word0(&rv) & Exp_mask)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1727 > Exp_msk1*(DBL_MAX_EXP+Bias-P))
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1728 goto ovfl;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1729 if (z > Exp_msk1*(DBL_MAX_EXP+Bias-1-P)) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1730 /* set to largest number */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1731 /* (Can't trust DBL_MAX) */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1732 word0(&rv) = Big0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1733 word1(&rv) = Big1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1734 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1735 else
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1736 word0(&rv) += P*Exp_msk1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1737 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1738 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1739 else if (e1 < 0) {
58427
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1740 /* The input decimal value lies in [10**e1, 10**(e1+16)).
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1741
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1742 If e1 <= -512, underflow immediately.
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1743 If e1 <= -256, set bc.scale to 2*P.
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1744
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1745 So for input value < 1e-256, bc.scale is always set;
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1746 for input value >= 1e-240, bc.scale is never set.
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1747 For input values in [1e-256, 1e-240), bc.scale may or may
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1748 not be set. */
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1749
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1750 e1 = -e1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1751 if ((i = e1 & 15))
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1752 dval(&rv) /= tens[i];
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1753 if (e1 >>= 4) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1754 if (e1 >= 1 << n_bigtens)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1755 goto undfl;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1756 if (e1 & Scale_Bit)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1757 bc.scale = 2*P;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1758 for(j = 0; e1 > 0; j++, e1 >>= 1)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1759 if (e1 & 1)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1760 dval(&rv) *= tinytens[j];
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1761 if (bc.scale && (j = 2*P + 1 - ((word0(&rv) & Exp_mask)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1762 >> Exp_shift)) > 0) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1763 /* scaled rv is denormal; clear j low bits */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1764 if (j >= 32) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1765 word1(&rv) = 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1766 if (j >= 53)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1767 word0(&rv) = (P+2)*Exp_msk1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1768 else
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1769 word0(&rv) &= 0xffffffff << (j-32);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1770 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1771 else
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1772 word1(&rv) &= 0xffffffff << j;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1773 }
58427
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1774 if (!dval(&rv))
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1775 goto undfl;
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1776 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1777 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1778
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1779 /* Now the hard part -- adjusting rv to the correct value.*/
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1780
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1781 /* Put digits into bd: true value = bd * 10^e */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1782
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1783 bc.nd = nd;
58279
c32d3b08fcdc Merged revisions 77410,77421,77450-77451 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58154
diff changeset
1784 bc.nd0 = nd0; /* Only needed if nd > STRTOD_DIGLIM, but done here */
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1785 /* to silence an erroneous warning about bc.nd0 */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1786 /* possibly not being initialized. */
58279
c32d3b08fcdc Merged revisions 77410,77421,77450-77451 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58154
diff changeset
1787 if (nd > STRTOD_DIGLIM) {
c32d3b08fcdc Merged revisions 77410,77421,77450-77451 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58154
diff changeset
1788 /* ASSERT(STRTOD_DIGLIM >= 18); 18 == one more than the */
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1789 /* minimum number of decimal digits to distinguish double values */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1790 /* in IEEE arithmetic. */
58360
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58320
diff changeset
1791
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58320
diff changeset
1792 /* Truncate input to 18 significant digits, then discard any trailing
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58320
diff changeset
1793 zeros on the result by updating nd, nd0, e and y suitably. (There's
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58320
diff changeset
1794 no need to update z; it's not reused beyond this point.) */
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58320
diff changeset
1795 for (i = 18; i > 0; ) {
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58320
diff changeset
1796 /* scan back until we hit a nonzero digit. significant digit 'i'
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58320
diff changeset
1797 is s0[i] if i < nd0, s0[i+1] if i >= nd0. */
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58320
diff changeset
1798 --i;
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58320
diff changeset
1799 if (s0[i < nd0 ? i : i+1] != '0') {
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58320
diff changeset
1800 ++i;
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1801 break;
58360
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58320
diff changeset
1802 }
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1803 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1804 e += nd - i;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1805 nd = i;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1806 if (nd0 > nd)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1807 nd0 = nd;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1808 if (nd < 9) { /* must recompute y */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1809 y = 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1810 for(i = 0; i < nd0; ++i)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1811 y = 10*y + s0[i] - '0';
58360
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58320
diff changeset
1812 for(; i < nd; ++i)
6351d3d53ded Merged revisions 77519,77530,77533 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58320
diff changeset
1813 y = 10*y + s0[i+1] - '0';
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1814 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1815 }
58320
ce11c1270b69 Merged revisions 77477-77478,77481-77483,77490-77493 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58279
diff changeset
1816 bd0 = s2b(s0, nd0, nd, y);
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1817 if (bd0 == NULL)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1818 goto failed_malloc;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1819
58427
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1820 /* Notation for the comments below. Write:
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1821
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1822 - dv for the absolute value of the number represented by the original
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1823 decimal input string.
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1824
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1825 - if we've truncated dv, write tdv for the truncated value.
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1826 Otherwise, set tdv == dv.
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1827
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1828 - srv for the quantity rv/2^bc.scale; so srv is the current binary
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1829 approximation to tdv (and dv). It should be exactly representable
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1830 in an IEEE 754 double.
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1831 */
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1832
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1833 for(;;) {
58427
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1834
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1835 /* This is the main correction loop for _Py_dg_strtod.
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1836
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1837 We've got a decimal value tdv, and a floating-point approximation
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1838 srv=rv/2^bc.scale to tdv. The aim is to determine whether srv is
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1839 close enough (i.e., within 0.5 ulps) to tdv, and to compute a new
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1840 approximation if not.
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1841
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1842 To determine whether srv is close enough to tdv, compute integers
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1843 bd, bb and bs proportional to tdv, srv and 0.5 ulp(srv)
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1844 respectively, and then use integer arithmetic to determine whether
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1845 |tdv - srv| is less than, equal to, or greater than 0.5 ulp(srv).
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1846 */
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1847
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1848 bd = Balloc(bd0->k);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1849 if (bd == NULL) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1850 Bfree(bd0);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1851 goto failed_malloc;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1852 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1853 Bcopy(bd, bd0);
58467
be12d3621519 Merged revisions 77691,77698,77713-77714 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58427
diff changeset
1854 bb = sd2b(&rv, bc.scale, &bbe); /* srv = bb * 2^bbe */
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1855 if (bb == NULL) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1856 Bfree(bd);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1857 Bfree(bd0);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1858 goto failed_malloc;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1859 }
58467
be12d3621519 Merged revisions 77691,77698,77713-77714 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58427
diff changeset
1860 /* Record whether lsb of bb is odd, in case we need this
be12d3621519 Merged revisions 77691,77698,77713-77714 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58427
diff changeset
1861 for the round-to-even step later. */
be12d3621519 Merged revisions 77691,77698,77713-77714 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58427
diff changeset
1862 odd = bb->x[0] & 1;
be12d3621519 Merged revisions 77691,77698,77713-77714 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58427
diff changeset
1863
be12d3621519 Merged revisions 77691,77698,77713-77714 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58427
diff changeset
1864 /* tdv = bd * 10**e; srv = bb * 2**bbe */
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1865 bs = i2b(1);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1866 if (bs == NULL) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1867 Bfree(bb);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1868 Bfree(bd);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1869 Bfree(bd0);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1870 goto failed_malloc;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1871 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1872
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1873 if (e >= 0) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1874 bb2 = bb5 = 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1875 bd2 = bd5 = e;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1876 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1877 else {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1878 bb2 = bb5 = -e;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1879 bd2 = bd5 = 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1880 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1881 if (bbe >= 0)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1882 bb2 += bbe;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1883 else
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1884 bd2 -= bbe;
58467
be12d3621519 Merged revisions 77691,77698,77713-77714 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58427
diff changeset
1885 bs2 = bb2;
be12d3621519 Merged revisions 77691,77698,77713-77714 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58427
diff changeset
1886 bb2++;
be12d3621519 Merged revisions 77691,77698,77713-77714 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58427
diff changeset
1887 bd2++;
58427
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1888
58467
be12d3621519 Merged revisions 77691,77698,77713-77714 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58427
diff changeset
1889 /* At this stage bd5 - bb5 == e == bd2 - bb2 + bbe, bb2 - bs2 == 1,
be12d3621519 Merged revisions 77691,77698,77713-77714 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58427
diff changeset
1890 and bs == 1, so:
58427
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1891
58467
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Mark Dickinson <dickinsm@gmail.com>
parents: 58427
diff changeset
1892 tdv == bd * 10**e = bd * 2**(bbe - bb2 + bd2) * 5**(bd5 - bb5)
be12d3621519 Merged revisions 77691,77698,77713-77714 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58427
diff changeset
1893 srv == bb * 2**bbe = bb * 2**(bbe - bb2 + bb2)
be12d3621519 Merged revisions 77691,77698,77713-77714 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58427
diff changeset
1894 0.5 ulp(srv) == 2**(bbe-1) = bs * 2**(bbe - bb2 + bs2)
be12d3621519 Merged revisions 77691,77698,77713-77714 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58427
diff changeset
1895
be12d3621519 Merged revisions 77691,77698,77713-77714 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58427
diff changeset
1896 It follows that:
58427
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1897
58467
be12d3621519 Merged revisions 77691,77698,77713-77714 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58427
diff changeset
1898 M * tdv = bd * 2**bd2 * 5**bd5
be12d3621519 Merged revisions 77691,77698,77713-77714 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58427
diff changeset
1899 M * srv = bb * 2**bb2 * 5**bb5
be12d3621519 Merged revisions 77691,77698,77713-77714 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58427
diff changeset
1900 M * 0.5 ulp(srv) = bs * 2**bs2 * 5**bb5
58427
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1901
58467
be12d3621519 Merged revisions 77691,77698,77713-77714 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58427
diff changeset
1902 for some constant M. (Actually, M == 2**(bb2 - bbe) * 5**bb5, but
be12d3621519 Merged revisions 77691,77698,77713-77714 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58427
diff changeset
1903 this fact is not needed below.)
58427
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1904 */
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1905
58467
be12d3621519 Merged revisions 77691,77698,77713-77714 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58427
diff changeset
1906 /* Remove factor of 2**i, where i = min(bb2, bd2, bs2). */
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1907 i = bb2 < bd2 ? bb2 : bd2;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1908 if (i > bs2)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1909 i = bs2;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1910 if (i > 0) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1911 bb2 -= i;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1912 bd2 -= i;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1913 bs2 -= i;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1914 }
58427
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1915
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1916 /* Scale bb, bd, bs by the appropriate powers of 2 and 5. */
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1917 if (bb5 > 0) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1918 bs = pow5mult(bs, bb5);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1919 if (bs == NULL) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1920 Bfree(bb);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1921 Bfree(bd);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1922 Bfree(bd0);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1923 goto failed_malloc;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1924 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1925 bb1 = mult(bs, bb);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1926 Bfree(bb);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1927 bb = bb1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1928 if (bb == NULL) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1929 Bfree(bs);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1930 Bfree(bd);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1931 Bfree(bd0);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1932 goto failed_malloc;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1933 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1934 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1935 if (bb2 > 0) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1936 bb = lshift(bb, bb2);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1937 if (bb == NULL) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1938 Bfree(bs);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1939 Bfree(bd);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1940 Bfree(bd0);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1941 goto failed_malloc;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1942 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1943 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1944 if (bd5 > 0) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1945 bd = pow5mult(bd, bd5);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1946 if (bd == NULL) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1947 Bfree(bb);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1948 Bfree(bs);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1949 Bfree(bd0);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1950 goto failed_malloc;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1951 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1952 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1953 if (bd2 > 0) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1954 bd = lshift(bd, bd2);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1955 if (bd == NULL) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1956 Bfree(bb);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1957 Bfree(bs);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1958 Bfree(bd0);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1959 goto failed_malloc;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1960 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1961 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1962 if (bs2 > 0) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1963 bs = lshift(bs, bs2);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1964 if (bs == NULL) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1965 Bfree(bb);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1966 Bfree(bd);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1967 Bfree(bd0);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1968 goto failed_malloc;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1969 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1970 }
58427
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1971
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1972 /* Now bd, bb and bs are scaled versions of tdv, srv and 0.5 ulp(srv),
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1973 respectively. Compute the difference |tdv - srv|, and compare
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1974 with 0.5 ulp(srv). */
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1975
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1976 delta = diff(bb, bd);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1977 if (delta == NULL) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1978 Bfree(bb);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1979 Bfree(bs);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1980 Bfree(bd);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1981 Bfree(bd0);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1982 goto failed_malloc;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1983 }
58427
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1984 dsign = delta->sign;
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1985 delta->sign = 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1986 i = cmp(delta, bs);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1987 if (bc.nd > nd && i <= 0) {
58427
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
1988 if (dsign)
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
1989 break; /* Must use bigcomp(). */
58320
ce11c1270b69 Merged revisions 77477-77478,77481-77483,77490-77493 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58279
diff changeset
1990
ce11c1270b69 Merged revisions 77477-77478,77481-77483,77490-77493 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58279
diff changeset
1991 /* Here rv overestimates the truncated decimal value by at most
ce11c1270b69 Merged revisions 77477-77478,77481-77483,77490-77493 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58279
diff changeset
1992 0.5 ulp(rv). Hence rv either overestimates the true decimal
ce11c1270b69 Merged revisions 77477-77478,77481-77483,77490-77493 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58279
diff changeset
1993 value by <= 0.5 ulp(rv), or underestimates it by some small
ce11c1270b69 Merged revisions 77477-77478,77481-77483,77490-77493 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58279
diff changeset
1994 amount (< 0.1 ulp(rv)); either way, rv is within 0.5 ulps of
ce11c1270b69 Merged revisions 77477-77478,77481-77483,77490-77493 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58279
diff changeset
1995 the true decimal value, so it's possible to exit.
ce11c1270b69 Merged revisions 77477-77478,77481-77483,77490-77493 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58279
diff changeset
1996
ce11c1270b69 Merged revisions 77477-77478,77481-77483,77490-77493 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58279
diff changeset
1997 Exception: if scaled rv is a normal exact power of 2, but not
ce11c1270b69 Merged revisions 77477-77478,77481-77483,77490-77493 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58279
diff changeset
1998 DBL_MIN, then rv - 0.5 ulp(rv) takes us all the way down to the
ce11c1270b69 Merged revisions 77477-77478,77481-77483,77490-77493 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58279
diff changeset
1999 next double, so the correctly rounded result is either rv - 0.5
ce11c1270b69 Merged revisions 77477-77478,77481-77483,77490-77493 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58279
diff changeset
2000 ulp(rv) or rv; in this case, use bigcomp to distinguish. */
ce11c1270b69 Merged revisions 77477-77478,77481-77483,77490-77493 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58279
diff changeset
2001
ce11c1270b69 Merged revisions 77477-77478,77481-77483,77490-77493 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58279
diff changeset
2002 if (!word1(&rv) && !(word0(&rv) & Bndry_mask)) {
ce11c1270b69 Merged revisions 77477-77478,77481-77483,77490-77493 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58279
diff changeset
2003 /* rv can't be 0, since it's an overestimate for some
ce11c1270b69 Merged revisions 77477-77478,77481-77483,77490-77493 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58279
diff changeset
2004 nonzero value. So rv is a normal power of 2. */
ce11c1270b69 Merged revisions 77477-77478,77481-77483,77490-77493 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58279
diff changeset
2005 j = (int)(word0(&rv) & Exp_mask) >> Exp_shift;
ce11c1270b69 Merged revisions 77477-77478,77481-77483,77490-77493 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58279
diff changeset
2006 /* rv / 2^bc.scale = 2^(j - 1023 - bc.scale); use bigcomp if
ce11c1270b69 Merged revisions 77477-77478,77481-77483,77490-77493 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58279
diff changeset
2007 rv / 2^bc.scale >= 2^-1021. */
ce11c1270b69 Merged revisions 77477-77478,77481-77483,77490-77493 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58279
diff changeset
2008 if (j - bc.scale >= 2) {
ce11c1270b69 Merged revisions 77477-77478,77481-77483,77490-77493 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58279
diff changeset
2009 dval(&rv) -= 0.5 * sulp(&rv, &bc);
58427
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
2010 break; /* Use bigcomp. */
58320
ce11c1270b69 Merged revisions 77477-77478,77481-77483,77490-77493 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58279
diff changeset
2011 }
ce11c1270b69 Merged revisions 77477-77478,77481-77483,77490-77493 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58279
diff changeset
2012 }
ce11c1270b69 Merged revisions 77477-77478,77481-77483,77490-77493 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58279
diff changeset
2013
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2014 {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2015 bc.nd = nd;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2016 i = -1; /* Discarded digits make delta smaller. */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2017 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2018 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2019
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2020 if (i < 0) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2021 /* Error is less than half an ulp -- check for
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2022 * special case of mantissa a power of two.
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2023 */
58427
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
2024 if (dsign || word1(&rv) || word0(&rv) & Bndry_mask
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2025 || (word0(&rv) & Exp_mask) <= (2*P+1)*Exp_msk1
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2026 ) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2027 break;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2028 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2029 if (!delta->x[0] && delta->wds <= 1) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2030 /* exact result */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2031 break;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2032 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2033 delta = lshift(delta,Log2P);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2034 if (delta == NULL) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2035 Bfree(bb);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2036 Bfree(bs);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2037 Bfree(bd);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2038 Bfree(bd0);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2039 goto failed_malloc;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2040 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2041 if (cmp(delta, bs) > 0)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2042 goto drop_down;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2043 break;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2044 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2045 if (i == 0) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2046 /* exactly half-way between */
58427
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
2047 if (dsign) {
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2048 if ((word0(&rv) & Bndry_mask1) == Bndry_mask1
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2049 && word1(&rv) == (
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2050 (bc.scale &&
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2051 (y = word0(&rv) & Exp_mask) <= 2*P*Exp_msk1) ?
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2052 (0xffffffff & (0xffffffff << (2*P+1-(y>>Exp_shift)))) :
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2053 0xffffffff)) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2054 /*boundary case -- increment exponent*/
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2055 word0(&rv) = (word0(&rv) & Exp_mask)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2056 + Exp_msk1
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2057 ;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2058 word1(&rv) = 0;
58427
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
2059 dsign = 0;
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2060 break;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2061 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2062 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2063 else if (!(word0(&rv) & Bndry_mask) && !word1(&rv)) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2064 drop_down:
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2065 /* boundary case -- decrement exponent */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2066 if (bc.scale) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2067 L = word0(&rv) & Exp_mask;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2068 if (L <= (2*P+1)*Exp_msk1) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2069 if (L > (P+2)*Exp_msk1)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2070 /* round even ==> */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2071 /* accept rv */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2072 break;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2073 /* rv = smallest denormal */
58427
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
2074 if (bc.nd > nd)
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2075 break;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2076 goto undfl;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2077 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2078 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2079 L = (word0(&rv) & Exp_mask) - Exp_msk1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2080 word0(&rv) = L | Bndry_mask1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2081 word1(&rv) = 0xffffffff;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2082 break;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2083 }
58467
be12d3621519 Merged revisions 77691,77698,77713-77714 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58427
diff changeset
2084 if (!odd)
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2085 break;
58427
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
2086 if (dsign)
58467
be12d3621519 Merged revisions 77691,77698,77713-77714 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58427
diff changeset
2087 dval(&rv) += sulp(&rv, &bc);
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2088 else {
58467
be12d3621519 Merged revisions 77691,77698,77713-77714 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58427
diff changeset
2089 dval(&rv) -= sulp(&rv, &bc);
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2090 if (!dval(&rv)) {
58279
c32d3b08fcdc Merged revisions 77410,77421,77450-77451 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58154
diff changeset
2091 if (bc.nd >nd)
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2092 break;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2093 goto undfl;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2094 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2095 }
58427
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
2096 dsign = 1 - dsign;
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2097 break;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2098 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2099 if ((aadj = ratio(delta, bs)) <= 2.) {
58427
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
2100 if (dsign)
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2101 aadj = aadj1 = 1.;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2102 else if (word1(&rv) || word0(&rv) & Bndry_mask) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2103 if (word1(&rv) == Tiny1 && !word0(&rv)) {
58279
c32d3b08fcdc Merged revisions 77410,77421,77450-77451 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58154
diff changeset
2104 if (bc.nd >nd)
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2105 break;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2106 goto undfl;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2107 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2108 aadj = 1.;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2109 aadj1 = -1.;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2110 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2111 else {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2112 /* special case -- power of FLT_RADIX to be */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2113 /* rounded down... */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2114
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2115 if (aadj < 2./FLT_RADIX)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2116 aadj = 1./FLT_RADIX;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2117 else
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2118 aadj *= 0.5;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2119 aadj1 = -aadj;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2120 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2121 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2122 else {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2123 aadj *= 0.5;
58427
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
2124 aadj1 = dsign ? aadj : -aadj;
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2125 if (Flt_Rounds == 0)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2126 aadj1 += 0.5;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2127 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2128 y = word0(&rv) & Exp_mask;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2129
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2130 /* Check for overflow */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2131
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2132 if (y == Exp_msk1*(DBL_MAX_EXP+Bias-1)) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2133 dval(&rv0) = dval(&rv);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2134 word0(&rv) -= P*Exp_msk1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2135 adj.d = aadj1 * ulp(&rv);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2136 dval(&rv) += adj.d;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2137 if ((word0(&rv) & Exp_mask) >=
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2138 Exp_msk1*(DBL_MAX_EXP+Bias-P)) {
58391
b9888c1339df Merged revisions 77578 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58360
diff changeset
2139 if (word0(&rv0) == Big0 && word1(&rv0) == Big1) {
b9888c1339df Merged revisions 77578 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58360
diff changeset
2140 Bfree(bb);
b9888c1339df Merged revisions 77578 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58360
diff changeset
2141 Bfree(bd);
b9888c1339df Merged revisions 77578 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58360
diff changeset
2142 Bfree(bs);
b9888c1339df Merged revisions 77578 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58360
diff changeset
2143 Bfree(bd0);
b9888c1339df Merged revisions 77578 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58360
diff changeset
2144 Bfree(delta);
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2145 goto ovfl;
58391
b9888c1339df Merged revisions 77578 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58360
diff changeset
2146 }
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2147 word0(&rv) = Big0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2148 word1(&rv) = Big1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2149 goto cont;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2150 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2151 else
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2152 word0(&rv) += P*Exp_msk1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2153 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2154 else {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2155 if (bc.scale && y <= 2*P*Exp_msk1) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2156 if (aadj <= 0x7fffffff) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2157 if ((z = (ULong)aadj) <= 0)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2158 z = 1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2159 aadj = z;
58427
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
2160 aadj1 = dsign ? aadj : -aadj;
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2161 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2162 dval(&aadj2) = aadj1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2163 word0(&aadj2) += (2*P+1)*Exp_msk1 - y;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2164 aadj1 = dval(&aadj2);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2165 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2166 adj.d = aadj1 * ulp(&rv);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2167 dval(&rv) += adj.d;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2168 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2169 z = word0(&rv) & Exp_mask;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2170 if (bc.nd == nd) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2171 if (!bc.scale)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2172 if (y == z) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2173 /* Can we stop now? */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2174 L = (Long)aadj;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2175 aadj -= L;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2176 /* The tolerances below are conservative. */
58427
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
2177 if (dsign || word1(&rv) || word0(&rv) & Bndry_mask) {
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2178 if (aadj < .4999999 || aadj > .5000001)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2179 break;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2180 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2181 else if (aadj < .4999999/FLT_RADIX)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2182 break;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2183 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2184 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2185 cont:
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2186 Bfree(bb);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2187 Bfree(bd);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2188 Bfree(bs);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2189 Bfree(delta);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2190 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2191 Bfree(bb);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2192 Bfree(bd);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2193 Bfree(bs);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2194 Bfree(bd0);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2195 Bfree(delta);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2196 if (bc.nd > nd) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2197 error = bigcomp(&rv, s0, &bc);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2198 if (error)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2199 goto failed_malloc;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2200 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2201
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2202 if (bc.scale) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2203 word0(&rv0) = Exp_1 - 2*P*Exp_msk1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2204 word1(&rv0) = 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2205 dval(&rv) *= dval(&rv0);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2206 }
58427
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
2207
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2208 ret:
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2209 return sign ? -dval(&rv) : dval(&rv);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2210
58427
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
2211 parse_error:
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
2212 return 0.0;
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
2213
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2214 failed_malloc:
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2215 errno = ENOMEM;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2216 return -1.0;
58427
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
2217
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
2218 undfl:
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
2219 return sign ? -0.0 : 0.0;
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
2220
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
2221 ovfl:
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
2222 errno = ERANGE;
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
2223 /* Can't trust HUGE_VAL */
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
2224 word0(&rv) = Exp_mask;
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
2225 word1(&rv) = 0;
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
2226 return sign ? -dval(&rv) : dval(&rv);
f38c1196d9ff Merged revisions 77614-77616,77663 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 58402
diff changeset
2227
53185
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2228 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2229
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2230 static char *
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2231 rv_alloc(int i)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2232 {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2233 int j, k, *r;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2234
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2235 j = sizeof(ULong);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2236 for(k = 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2237 sizeof(Bigint) - sizeof(ULong) - sizeof(int) + j <= (unsigned)i;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2238 j <<= 1)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2239 k++;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2240 r = (int*)Balloc(k);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2241 if (r == NULL)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2242 return NULL;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2243 *r = k;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2244 return (char *)(r+1);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2245 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2246
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2247 static char *
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2248 nrv_alloc(char *s, char **rve, int n)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2249 {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2250 char *rv, *t;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2251
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2252 rv = rv_alloc(n);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2253 if (rv == NULL)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2254 return NULL;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2255 t = rv;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2256 while((*t = *s++)) t++;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2257 if (rve)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2258 *rve = t;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2259 return rv;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2260 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2261
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2262 /* freedtoa(s) must be used to free values s returned by dtoa
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2263 * when MULTIPLE_THREADS is #defined. It should be used in all cases,
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2264 * but for consistency with earlier versions of dtoa, it is optional
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2265 * when MULTIPLE_THREADS is not defined.
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2266 */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2267
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2268 void
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2269 _Py_dg_freedtoa(char *s)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2270 {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2271 Bigint *b = (Bigint *)((int *)s - 1);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2272 b->maxwds = 1 << (b->k = *(int*)b);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2273 Bfree(b);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2274 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2275
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2276 /* dtoa for IEEE arithmetic (dmg): convert double to ASCII string.
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2277 *
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2278 * Inspired by "How to Print Floating-Point Numbers Accurately" by
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2279 * Guy L. Steele, Jr. and Jon L. White [Proc. ACM SIGPLAN '90, pp. 112-126].
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2280 *
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2281 * Modifications:
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2282 * 1. Rather than iterating, we use a simple numeric overestimate
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2283 * to determine k = floor(log10(d)). We scale relevant
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2284 * quantities using O(log2(k)) rather than O(k) multiplications.
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2285 * 2. For some modes > 2 (corresponding to ecvt and fcvt), we don't
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2286 * try to generate digits strictly left to right. Instead, we
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2287 * compute with fewer bits and propagate the carry if necessary
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2288 * when rounding the final digit up. This is often faster.
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2289 * 3. Under the assumption that input will be rounded nearest,
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2290 * mode 0 renders 1e23 as 1e23 rather than 9.999999999999999e22.
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2291 * That is, we allow equality in stopping tests when the
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2292 * round-nearest rule will give the same floating-point value
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2293 * as would satisfaction of the stopping test with strict
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2294 * inequality.
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2295 * 4. We remove common factors of powers of 2 from relevant
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2296 * quantities.
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2297 * 5. When converting floating-point integers less than 1e16,
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2298 * we use floating-point arithmetic rather than resorting
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2299 * to multiple-precision integers.
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2300 * 6. When asked to produce fewer than 15 digits, we first try
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2301 * to get by with floating-point arithmetic; we resort to
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2302 * multiple-precision integer arithmetic only if we cannot
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2303 * guarantee that the floating-point calculation has given
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2304 * the correctly rounded result. For k requested digits and
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2305 * "uniformly" distributed input, the probability is
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2306 * something like 10^(k-15) that we must resort to the Long
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2307 * calculation.
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2308 */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2309
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2310 /* Additional notes (METD): (1) returns NULL on failure. (2) to avoid memory
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2311 leakage, a successful call to _Py_dg_dtoa should always be matched by a
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2312 call to _Py_dg_freedtoa. */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2313
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2314 char *
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2315 _Py_dg_dtoa(double dd, int mode, int ndigits,
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2316 int *decpt, int *sign, char **rve)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2317 {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2318 /* Arguments ndigits, decpt, sign are similar to those
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2319 of ecvt and fcvt; trailing zeros are suppressed from
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2320 the returned string. If not null, *rve is set to point
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2321 to the end of the return value. If d is +-Infinity or NaN,
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2322 then *decpt is set to 9999.
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2323
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2324 mode:
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2325 0 ==> shortest string that yields d when read in
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2326 and rounded to nearest.
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2327 1 ==> like 0, but with Steele & White stopping rule;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2328 e.g. with IEEE P754 arithmetic , mode 0 gives
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2329 1e23 whereas mode 1 gives 9.999999999999999e22.
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2330 2 ==> max(1,ndigits) significant digits. This gives a
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2331 return value similar to that of ecvt, except
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2332 that trailing zeros are suppressed.
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2333 3 ==> through ndigits past the decimal point. This
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2334 gives a return value similar to that from fcvt,
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2335 except that trailing zeros are suppressed, and
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2336 ndigits can be negative.
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2337 4,5 ==> similar to 2 and 3, respectively, but (in
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2338 round-nearest mode) with the tests of mode 0 to
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2339 possibly return a shorter string that rounds to d.
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2340 With IEEE arithmetic and compilation with
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2341 -DHonor_FLT_ROUNDS, modes 4 and 5 behave the same
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2342 as modes 2 and 3 when FLT_ROUNDS != 1.
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2343 6-9 ==> Debugging modes similar to mode - 4: don't try
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2344 fast floating-point estimate (if applicable).
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2345
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2346 Values of mode other than 0-9 are treated as mode 0.
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2347
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2348 Sufficient space is allocated to the return value
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2349 to hold the suppressed trailing zeros.
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2350 */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2351
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2352 int bbits, b2, b5, be, dig, i, ieps, ilim, ilim0, ilim1,
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2353 j, j1, k, k0, k_check, leftright, m2, m5, s2, s5,
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2354 spec_case, try_quick;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2355 Long L;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2356 int denorm;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2357 ULong x;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2358 Bigint *b, *b1, *delta, *mlo, *mhi, *S;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2359 U d2, eps, u;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2360 double ds;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2361 char *s, *s0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2362
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2363 /* set pointers to NULL, to silence gcc compiler warnings and make
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2364 cleanup easier on error */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2365 mlo = mhi = b = S = 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2366 s0 = 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2367
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2368 u.d = dd;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2369 if (word0(&u) & Sign_bit) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2370 /* set sign for everything, including 0's and NaNs */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2371 *sign = 1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2372 word0(&u) &= ~Sign_bit; /* clear sign bit */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2373 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2374 else
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2375 *sign = 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2376
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2377 /* quick return for Infinities, NaNs and zeros */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2378 if ((word0(&u) & Exp_mask) == Exp_mask)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2379 {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2380 /* Infinity or NaN */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2381 *decpt = 9999;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2382 if (!word1(&u) && !(word0(&u) & 0xfffff))
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2383 return nrv_alloc("Infinity", rve, 8);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2384 return nrv_alloc("NaN", rve, 3);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2385 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2386 if (!dval(&u)) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2387 *decpt = 1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2388 return nrv_alloc("0", rve, 1);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2389 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2390
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2391 /* compute k = floor(log10(d)). The computation may leave k
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2392 one too large, but should never leave k too small. */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2393 b = d2b(&u, &be, &bbits);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2394 if (b == NULL)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2395 goto failed_malloc;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2396 if ((i = (int)(word0(&u) >> Exp_shift1 & (Exp_mask>>Exp_shift1)))) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2397 dval(&d2) = dval(&u);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2398 word0(&d2) &= Frac_mask1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2399 word0(&d2) |= Exp_11;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2400
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2401 /* log(x) ~=~ log(1.5) + (x-1.5)/1.5
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2402 * log10(x) = log(x) / log(10)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2403 * ~=~ log(1.5)/log(10) + (x-1.5)/(1.5*log(10))
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2404 * log10(d) = (i-Bias)*log(2)/log(10) + log10(d2)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2405 *
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2406 * This suggests computing an approximation k to log10(d) by
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2407 *
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2408 * k = (i - Bias)*0.301029995663981
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2409 * + ( (d2-1.5)*0.289529654602168 + 0.176091259055681 );
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2410 *
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2411 * We want k to be too large rather than too small.
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2412 * The error in the first-order Taylor series approximation
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2413 * is in our favor, so we just round up the constant enough
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2414 * to compensate for any error in the multiplication of
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2415 * (i - Bias) by 0.301029995663981; since |i - Bias| <= 1077,
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2416 * and 1077 * 0.30103 * 2^-52 ~=~ 7.2e-14,
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2417 * adding 1e-13 to the constant term more than suffices.
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2418 * Hence we adjust the constant term to 0.1760912590558.
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2419 * (We could get a more accurate k by invoking log10,
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2420 * but this is probably not worthwhile.)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2421 */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2422
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2423 i -= Bias;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2424 denorm = 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2425 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2426 else {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2427 /* d is denormalized */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2428
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2429 i = bbits + be + (Bias + (P-1) - 1);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2430 x = i > 32 ? word0(&u) << (64 - i) | word1(&u) >> (i - 32)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2431 : word1(&u) << (32 - i);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2432 dval(&d2) = x;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2433 word0(&d2) -= 31*Exp_msk1; /* adjust exponent */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2434 i -= (Bias + (P-1) - 1) + 1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2435 denorm = 1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2436 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2437 ds = (dval(&d2)-1.5)*0.289529654602168 + 0.1760912590558 +
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2438 i*0.301029995663981;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2439 k = (int)ds;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2440 if (ds < 0. && ds != k)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2441 k--; /* want k = floor(ds) */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2442 k_check = 1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2443 if (k >= 0 && k <= Ten_pmax) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2444 if (dval(&u) < tens[k])
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2445 k--;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2446 k_check = 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2447 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2448 j = bbits - i - 1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2449 if (j >= 0) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2450 b2 = 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2451 s2 = j;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2452 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2453 else {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2454 b2 = -j;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2455 s2 = 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2456 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2457 if (k >= 0) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2458 b5 = 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2459 s5 = k;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2460 s2 += k;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2461 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2462 else {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2463 b2 -= k;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2464 b5 = -k;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2465 s5 = 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2466 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2467 if (mode < 0 || mode > 9)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2468 mode = 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2469
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2470 try_quick = 1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2471
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2472 if (mode > 5) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2473 mode -= 4;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2474 try_quick = 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2475 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2476 leftright = 1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2477 ilim = ilim1 = -1; /* Values for cases 0 and 1; done here to */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2478 /* silence erroneous "gcc -Wall" warning. */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2479 switch(mode) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2480 case 0:
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2481 case 1:
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2482 i = 18;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2483 ndigits = 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2484 break;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2485 case 2:
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2486 leftright = 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2487 /* no break */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2488 case 4:
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2489 if (ndigits <= 0)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2490 ndigits = 1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2491 ilim = ilim1 = i = ndigits;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2492 break;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2493 case 3:
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2494 leftright = 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2495 /* no break */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2496 case 5:
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2497 i = ndigits + k + 1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2498 ilim = i;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2499 ilim1 = i - 1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2500 if (i <= 0)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2501 i = 1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2502 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2503 s0 = rv_alloc(i);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2504 if (s0 == NULL)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2505 goto failed_malloc;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2506 s = s0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2507
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2508
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2509 if (ilim >= 0 && ilim <= Quick_max && try_quick) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2510
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2511 /* Try to get by with floating-point arithmetic. */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2512
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2513 i = 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2514 dval(&d2) = dval(&u);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2515 k0 = k;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2516 ilim0 = ilim;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2517 ieps = 2; /* conservative */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2518 if (k > 0) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2519 ds = tens[k&0xf];
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2520 j = k >> 4;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2521 if (j & Bletch) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2522 /* prevent overflows */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2523 j &= Bletch - 1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2524 dval(&u) /= bigtens[n_bigtens-1];
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2525 ieps++;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2526 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2527 for(; j; j >>= 1, i++)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2528 if (j & 1) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2529 ieps++;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2530 ds *= bigtens[i];
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2531 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2532 dval(&u) /= ds;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2533 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2534 else if ((j1 = -k)) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2535 dval(&u) *= tens[j1 & 0xf];
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2536 for(j = j1 >> 4; j; j >>= 1, i++)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2537 if (j & 1) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2538 ieps++;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2539 dval(&u) *= bigtens[i];
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2540 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2541 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2542 if (k_check && dval(&u) < 1. && ilim > 0) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2543 if (ilim1 <= 0)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2544 goto fast_failed;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2545 ilim = ilim1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2546 k--;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2547 dval(&u) *= 10.;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2548 ieps++;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2549 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2550 dval(&eps) = ieps*dval(&u) + 7.;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2551 word0(&eps) -= (P-1)*Exp_msk1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2552 if (ilim == 0) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2553 S = mhi = 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2554 dval(&u) -= 5.;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2555 if (dval(&u) > dval(&eps))
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2556 goto one_digit;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2557 if (dval(&u) < -dval(&eps))
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2558 goto no_digits;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2559 goto fast_failed;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2560 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2561 if (leftright) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2562 /* Use Steele & White method of only
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2563 * generating digits needed.
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2564 */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2565 dval(&eps) = 0.5/tens[ilim-1] - dval(&eps);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2566 for(i = 0;;) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2567 L = (Long)dval(&u);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2568 dval(&u) -= L;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2569 *s++ = '0' + (int)L;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2570 if (dval(&u) < dval(&eps))
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2571 goto ret1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2572 if (1. - dval(&u) < dval(&eps))
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2573 goto bump_up;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2574 if (++i >= ilim)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2575 break;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2576 dval(&eps) *= 10.;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2577 dval(&u) *= 10.;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2578 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2579 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2580 else {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2581 /* Generate ilim digits, then fix them up. */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2582 dval(&eps) *= tens[ilim-1];
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2583 for(i = 1;; i++, dval(&u) *= 10.) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2584 L = (Long)(dval(&u));
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2585 if (!(dval(&u) -= L))
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2586 ilim = i;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2587 *s++ = '0' + (int)L;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2588 if (i == ilim) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2589 if (dval(&u) > 0.5 + dval(&eps))
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2590 goto bump_up;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2591 else if (dval(&u) < 0.5 - dval(&eps)) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2592 while(*--s == '0');
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2593 s++;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2594 goto ret1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2595 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2596 break;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2597 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2598 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2599 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2600 fast_failed:
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2601 s = s0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2602 dval(&u) = dval(&d2);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2603 k = k0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2604 ilim = ilim0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2605 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2606
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2607 /* Do we have a "small" integer? */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2608
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2609 if (be >= 0 && k <= Int_max) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2610 /* Yes. */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2611 ds = tens[k];
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2612 if (ndigits < 0 && ilim <= 0) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2613 S = mhi = 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2614 if (ilim < 0 || dval(&u) <= 5*ds)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2615 goto no_digits;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2616 goto one_digit;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2617 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2618 for(i = 1;; i++, dval(&u) *= 10.) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2619 L = (Long)(dval(&u) / ds);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2620 dval(&u) -= L*ds;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2621 *s++ = '0' + (int)L;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2622 if (!dval(&u)) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2623 break;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2624 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2625 if (i == ilim) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2626 dval(&u) += dval(&u);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2627 if (dval(&u) > ds || (dval(&u) == ds && L & 1)) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2628 bump_up:
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2629 while(*--s == '9')
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2630 if (s == s0) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2631 k++;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2632 *s = '0';
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2633 break;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2634 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2635 ++*s++;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2636 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2637 break;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2638 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2639 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2640 goto ret1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2641 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2642
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2643 m2 = b2;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2644 m5 = b5;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2645 if (leftright) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2646 i =
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2647 denorm ? be + (Bias + (P-1) - 1 + 1) :
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2648 1 + P - bbits;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2649 b2 += i;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2650 s2 += i;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2651 mhi = i2b(1);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2652 if (mhi == NULL)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2653 goto failed_malloc;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2654 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2655 if (m2 > 0 && s2 > 0) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2656 i = m2 < s2 ? m2 : s2;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2657 b2 -= i;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2658 m2 -= i;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2659 s2 -= i;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2660 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2661 if (b5 > 0) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2662 if (leftright) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2663 if (m5 > 0) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2664 mhi = pow5mult(mhi, m5);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2665 if (mhi == NULL)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2666 goto failed_malloc;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2667 b1 = mult(mhi, b);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2668 Bfree(b);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2669 b = b1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2670 if (b == NULL)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2671 goto failed_malloc;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2672 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2673 if ((j = b5 - m5)) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2674 b = pow5mult(b, j);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2675 if (b == NULL)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2676 goto failed_malloc;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2677 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2678 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2679 else {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2680 b = pow5mult(b, b5);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2681 if (b == NULL)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2682 goto failed_malloc;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2683 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2684 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2685 S = i2b(1);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2686 if (S == NULL)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2687 goto failed_malloc;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2688 if (s5 > 0) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2689 S = pow5mult(S, s5);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2690 if (S == NULL)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2691 goto failed_malloc;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2692 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2693
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2694 /* Check for special case that d is a normalized power of 2. */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2695
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2696 spec_case = 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2697 if ((mode < 2 || leftright)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2698 ) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2699 if (!word1(&u) && !(word0(&u) & Bndry_mask)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2700 && word0(&u) & (Exp_mask & ~Exp_msk1)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2701 ) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2702 /* The special case */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2703 b2 += Log2P;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2704 s2 += Log2P;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2705 spec_case = 1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2706 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2707 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2708
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2709 /* Arrange for convenient computation of quotients:
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2710 * shift left if necessary so divisor has 4 leading 0 bits.
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2711 *
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2712 * Perhaps we should just compute leading 28 bits of S once
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2713 * and for all and pass them and a shift to quorem, so it
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2714 * can do shifts and ors to compute the numerator for q.
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2715 */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2716 if ((i = ((s5 ? 32 - hi0bits(S->x[S->wds-1]) : 1) + s2) & 0x1f))
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2717 i = 32 - i;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2718 #define iInc 28
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2719 i = dshift(S, s2);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2720 b2 += i;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2721 m2 += i;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2722 s2 += i;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2723 if (b2 > 0) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2724 b = lshift(b, b2);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2725 if (b == NULL)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2726 goto failed_malloc;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2727 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2728 if (s2 > 0) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2729 S = lshift(S, s2);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2730 if (S == NULL)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2731 goto failed_malloc;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2732 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2733 if (k_check) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2734 if (cmp(b,S) < 0) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2735 k--;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2736 b = multadd(b, 10, 0); /* we botched the k estimate */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2737 if (b == NULL)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2738 goto failed_malloc;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2739 if (leftright) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2740 mhi = multadd(mhi, 10, 0);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2741 if (mhi == NULL)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2742 goto failed_malloc;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2743 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2744 ilim = ilim1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2745 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2746 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2747 if (ilim <= 0 && (mode == 3 || mode == 5)) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2748 if (ilim < 0) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2749 /* no digits, fcvt style */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2750 no_digits:
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2751 k = -1 - ndigits;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2752 goto ret;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2753 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2754 else {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2755 S = multadd(S, 5, 0);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2756 if (S == NULL)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2757 goto failed_malloc;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2758 if (cmp(b, S) <= 0)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2759 goto no_digits;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2760 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2761 one_digit:
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2762 *s++ = '1';
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2763 k++;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2764 goto ret;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2765 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2766 if (leftright) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2767 if (m2 > 0) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2768 mhi = lshift(mhi, m2);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2769 if (mhi == NULL)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2770 goto failed_malloc;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2771 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2772
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2773 /* Compute mlo -- check for special case
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2774 * that d is a normalized power of 2.
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2775 */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2776
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2777 mlo = mhi;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2778 if (spec_case) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2779 mhi = Balloc(mhi->k);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2780 if (mhi == NULL)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2781 goto failed_malloc;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2782 Bcopy(mhi, mlo);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2783 mhi = lshift(mhi, Log2P);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2784 if (mhi == NULL)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2785 goto failed_malloc;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2786 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2787
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2788 for(i = 1;;i++) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2789 dig = quorem(b,S) + '0';
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2790 /* Do we yet have the shortest decimal string
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2791 * that will round to d?
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2792 */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2793 j = cmp(b, mlo);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2794 delta = diff(S, mhi);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2795 if (delta == NULL)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2796 goto failed_malloc;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2797 j1 = delta->sign ? 1 : cmp(b, delta);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2798 Bfree(delta);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2799 if (j1 == 0 && mode != 1 && !(word1(&u) & 1)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2800 ) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2801 if (dig == '9')
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2802 goto round_9_up;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2803 if (j > 0)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2804 dig++;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2805 *s++ = dig;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2806 goto ret;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2807 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2808 if (j < 0 || (j == 0 && mode != 1
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2809 && !(word1(&u) & 1)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2810 )) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2811 if (!b->x[0] && b->wds <= 1) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2812 goto accept_dig;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2813 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2814 if (j1 > 0) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2815 b = lshift(b, 1);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2816 if (b == NULL)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2817 goto failed_malloc;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2818 j1 = cmp(b, S);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2819 if ((j1 > 0 || (j1 == 0 && dig & 1))
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2820 && dig++ == '9')
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2821 goto round_9_up;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2822 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2823 accept_dig:
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2824 *s++ = dig;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2825 goto ret;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2826 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2827 if (j1 > 0) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2828 if (dig == '9') { /* possible if i == 1 */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2829 round_9_up:
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2830 *s++ = '9';
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2831 goto roundoff;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2832 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2833 *s++ = dig + 1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2834 goto ret;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2835 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2836 *s++ = dig;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2837 if (i == ilim)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2838 break;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2839 b = multadd(b, 10, 0);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2840 if (b == NULL)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2841 goto failed_malloc;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2842 if (mlo == mhi) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2843 mlo = mhi = multadd(mhi, 10, 0);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2844 if (mlo == NULL)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2845 goto failed_malloc;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2846 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2847 else {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2848 mlo = multadd(mlo, 10, 0);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2849 if (mlo == NULL)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2850 goto failed_malloc;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2851 mhi = multadd(mhi, 10, 0);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2852 if (mhi == NULL)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2853 goto failed_malloc;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2854 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2855 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2856 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2857 else
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2858 for(i = 1;; i++) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2859 *s++ = dig = quorem(b,S) + '0';
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2860 if (!b->x[0] && b->wds <= 1) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2861 goto ret;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2862 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2863 if (i >= ilim)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2864 break;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2865 b = multadd(b, 10, 0);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2866 if (b == NULL)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2867 goto failed_malloc;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2868 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2869
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2870 /* Round off last digit */
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2871
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2872 b = lshift(b, 1);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2873 if (b == NULL)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2874 goto failed_malloc;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2875 j = cmp(b, S);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2876 if (j > 0 || (j == 0 && dig & 1)) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2877 roundoff:
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2878 while(*--s == '9')
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2879 if (s == s0) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2880 k++;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2881 *s++ = '1';
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2882 goto ret;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2883 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2884 ++*s++;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2885 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2886 else {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2887 while(*--s == '0');
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2888 s++;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2889 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2890 ret:
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2891 Bfree(S);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2892 if (mhi) {
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2893 if (mlo && mlo != mhi)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2894 Bfree(mlo);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2895 Bfree(mhi);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2896 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2897 ret1:
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2898 Bfree(b);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2899 *s = 0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2900 *decpt = k + 1;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2901 if (rve)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2902 *rve = s;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2903 return s0;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2904 failed_malloc:
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2905 if (S)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2906 Bfree(S);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2907 if (mlo && mlo != mhi)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2908 Bfree(mlo);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2909 if (mhi)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2910 Bfree(mhi);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2911 if (b)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2912 Bfree(b);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2913 if (s0)
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2914 _Py_dg_freedtoa(s0);
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2915 return NULL;
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2916 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2917 #ifdef __cplusplus
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
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2918 }
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2919 #endif
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2920
97ae7a709c1d Issue #1580: use short float repr where possible.
Mark Dickinson <dickinsm@gmail.com>
parents:
diff changeset
2921 #endif /* PY_NO_SHORT_FLOAT_REPR */