newlib-cygwin/newlib/libm/math/sf_isnan.c

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2000-02-18 03:39:52 +08:00
/* sf_isnan.c -- float version of s_isnan.c.
* Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
*/
/*
* ====================================================
* 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.
* ====================================================
*/
/*
* isnanf(x) returns 1 is x is nan, else 0;
* no branching!
*/
#include "fdlibm.h"
#ifdef __STDC__
int isnanf(float x)
#else
int isnanf(x)
float x;
#endif
{
__int32_t ix;
GET_FLOAT_WORD(ix,x);
ix &= 0x7fffffff;
ix = 0x7f800000 - ix;
return (int)(((__uint32_t)(ix))>>31);
}
#ifdef _DOUBLE_IS_32BITS
#ifdef __STDC__
int isnan(double x)
#else
int isnan(x)
double x;
#endif
{
return isnanf((float) x);
}
#endif /* defined(_DOUBLE_IS_32BITS) */