Mercurial > cpython-lru_cache-weakref
diff Python/pymath.c @ 51485:f9f2ed79b00f
Merged revisions 69459 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/trunk
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r69459 | mark.dickinson | 2009-02-09 14:18:43 +0000 (Mon, 09 Feb 2009) | 3 lines
Issue #4575: fix Py_IS_INFINITY macro to work correctly on x87 FPUs.
It now forces its argument to double before testing for infinity.
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| author | Mark Dickinson <dickinsm@gmail.com> |
|---|---|
| date | Mon, 09 Feb 2009 17:15:59 +0000 |
| parents | e86ed113535c |
| children | ad5c7eaccea1 97ae7a709c1d |
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--- a/Python/pymath.c Mon Feb 09 16:44:24 2009 +0000 +++ b/Python/pymath.c Mon Feb 09 17:15:59 2009 +0000 @@ -1,5 +1,18 @@ #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 + #ifndef HAVE_HYPOT double hypot(double x, double y) {