Retro68/gcc/newlib/libm/common/s_isinf.c
Wolfgang Thaller ec13cc9ce7 fix newlib
2018-12-29 09:59:36 +01:00

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 */