mirror of
https://github.com/autc04/Retro68.git
synced 2024-12-01 11:52:47 +00:00
30 lines
629 B
C
30 lines
629 B
C
/*
|
|
* isinf(x) returns 1 if x is infinity, else 0;
|
|
* no branching!
|
|
*
|
|
* isinf is a <math.h> macro in the C99 standard. It was previously
|
|
* implemented as a function by newlib and is declared as such in
|
|
* <math.h>. Newlib supplies it here as a function if the user
|
|
* chooses to use it instead of the C99 macro.
|
|
*/
|
|
|
|
#include "fdlibm.h"
|
|
#include <ieeefp.h>
|
|
|
|
#ifndef _DOUBLE_IS_32BITS
|
|
|
|
#undef isinf
|
|
|
|
int
|
|
isinf (double x)
|
|
{
|
|
__int32_t hx,lx;
|
|
EXTRACT_WORDS(hx,lx,x);
|
|
hx &= 0x7fffffff;
|
|
hx |= (__uint32_t)(lx|(-lx))>>31;
|
|
hx = 0x7ff00000 - hx;
|
|
return 1 - (int)((__uint32_t)(hx|(-hx))>>31);
|
|
}
|
|
|
|
#endif /* _DOUBLE_IS_32BITS */
|