view Python/pymath.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 9751ddcc1882
children cab14be0ada1
line wrap: on
line source

#include "Python.h"

#ifdef X87_DOUBLE_ROUNDING
/* On x86 platforms using an x87 FPU, this function is called from the
   Py_FORCE_DOUBLE macro (defined in pymath.h) to force a floating-point
   number out of an 80-bit x87 FPU register and into a 64-bit memory location,
   thus rounding from extended precision to double precision. */
double _Py_force_double(double x)
{
	volatile double y;
	y = x;
	return y;
}
#endif

#ifdef HAVE_GCC_ASM_FOR_X87

/* inline assembly for getting and setting the 387 FPU control word on
   gcc/x86 */

unsigned short _Py_get_387controlword(void) {
    unsigned short cw;
    __asm__ __volatile__ ("fnstcw %0" : "=m" (cw));
    return cw;
}

void _Py_set_387controlword(unsigned short cw) {
    __asm__ __volatile__ ("fldcw %0" : : "m" (cw));
}

#endif


#ifndef HAVE_HYPOT
double hypot(double x, double y)
{
	double yx;

	x = fabs(x);
	y = fabs(y);
	if (x < y) {
		double temp = x;
		x = y;
		y = temp;
	}
	if (x == 0.)
		return 0.;
	else {
		yx = y/x;
		return x*sqrt(1.+yx*yx);
	}
}
#endif /* HAVE_HYPOT */

#ifndef HAVE_COPYSIGN
double
copysign(double x, double y)
{
	/* use atan2 to distinguish -0. from 0. */
	if (y > 0. || (y == 0. && atan2(y, -1.) > 0.)) {
		return fabs(x);
	} else {
		return -fabs(x);
	}
}
#endif /* HAVE_COPYSIGN */

#ifndef HAVE_ROUND
double
round(double x)
{
    double absx, y;
    absx = fabs(x);
    y = floor(absx);
    if (absx - y >= 0.5)
        y += 1.0;
    return copysign(y, x);
}
#endif /* HAVE_ROUND */