30 lines
693 B
C
30 lines
693 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
|
||
|
|
* <ieeefp.h>. Newlib supplies it here as a function if the user
|
||
|
|
* chooses to use <ieeefp.h> or needs to link older code compiled with the
|
||
|
|
* previous <math.h> declaration.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include "fdlibm.h"
|
||
|
|
#include <ieeefp.h>
|
||
|
|
|
||
|
|
#ifndef _DOUBLE_IS_32BITS
|
||
|
|
|
||
|
|
int
|
||
|
|
_DEFUN (isinf, (x),
|
||
|
|
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 */
|