Mercurial > mxe-octave
comparison src/build-msvctools/math/fpclassify.c @ 3061:f8299bb6c872
Initial support for native MSVC compilation.
* add MSVC support files: compiler wrappers and support libraries
* adapt libiconv to work with MSVC
* adapt gettext to work with MSVC
| author | Michael Goffioul <michael.goffioul@gmail.com> |
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| date | Mon, 17 Jun 2013 22:43:11 -0400 |
| parents | |
| children |
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| 3060:cbdf4575016d | 3061:f8299bb6c872 |
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| 1 #include <math.h> | |
| 2 | |
| 3 /* 'fxam' sets FPU flags C3,C2,C0 'fstsw' stores: | |
| 4 FP_NAN 001 0x0100 | |
| 5 FP_NORMAL 010 0x0400 | |
| 6 FP_INFINITE 011 0x0500 | |
| 7 FP_ZERO 100 0x4000 | |
| 8 FP_SUBNORMAL 110 0x4400 | |
| 9 | |
| 10 and sets C1 flag (signbit) if neg */ | |
| 11 | |
| 12 int __fpclassify (double _x){ | |
| 13 unsigned short sw; | |
| 14 __asm__ ( | |
| 15 "fxam; fstsw %%ax;" | |
| 16 : "=a" (sw) | |
| 17 : "t" (_x) | |
| 18 ); | |
| 19 return sw & (FP_NAN | FP_NORMAL | FP_ZERO ); | |
| 20 } |