kolibrios-fun/programs/develop/libraries/newlib/math/fpclassify.c
Sergey Semyonov (Serge) 2336060a0c newlib: update
git-svn-id: svn://kolibrios.org@1906 a494cfbc-eb01-0410-851d-a64ba20cac60
2011-03-11 18:52:24 +00:00

21 lines
414 B
C

#include <math.h>
/* 'fxam' sets FPU flags C3,C2,C0 'fstsw' stores:
FP_NAN 001 0x0100
FP_NORMAL 010 0x0400
FP_INFINITE 011 0x0500
FP_ZERO 100 0x4000
FP_SUBNORMAL 110 0x4400
and sets C1 flag (signbit) if neg */
int __fpclassify (double _x){
unsigned short sw;
__asm__ (
"fxam; fstsw %%ax;"
: "=a" (sw)
: "t" (_x)
);
return sw & (FP_NAN | FP_NORMAL | FP_ZERO );
}