21 lines
394 B
C
21 lines
394 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 );
|
|
}
|