glibc/sysdeps/ieee754/dbl-64/s_isnan.c
2012-01-27 17:29:45 +00:00

41 lines
990 B
C

/* @(#)s_isnan.c 5.1 93/09/24 */
/*
* ====================================================
* 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.
* ====================================================
*/
#if defined(LIBM_SCCS) && !defined(lint)
static char rcsid[] = "$NetBSD: s_isnan.c,v 1.8 1995/05/10 20:47:36 jtc Exp $";
#endif
/*
* isnan(x) returns 1 is x is nan, else 0;
* no branching!
*/
#include "math.h"
#include "math_private.h"
#undef __isnan
int __isnan(double x)
{
int32_t hx,lx;
EXTRACT_WORDS(hx,lx,x);
hx &= 0x7fffffff;
hx |= (u_int32_t)(lx|(-lx))>>31;
hx = 0x7ff00000 - hx;
return (int)(((u_int32_t)hx)>>31);
}
hidden_def (__isnan)
weak_alias (__isnan, isnan)
#ifdef NO_LONG_DOUBLE
strong_alias (__isnan, __isnanl)
weak_alias (__isnan, isnanl)
#endif