File: s_isinf.c

package info (click to toggle)
picolibc 1.5.1-2
  • links: PTS, VCS
  • area: main
  • in suites: bullseye
  • size: 27,124 kB
  • sloc: ansic: 266,005; asm: 22,255; perl: 2,388; sh: 1,016; python: 994; exp: 282; makefile: 94; xml: 39
file content (37 lines) | stat: -rw-r--r-- 881 bytes parent folder | download
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
/*
Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.

Developed at SunPro, a Sun Microsystems, Inc. business.
Permission to use, copy, modify, and distribute this
software is freely granted, provided that this notice 
is preserved.
 */
/*
 * 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 */