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

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2000-02-18 03:39:52 +08:00
/* ef_scalb.c -- float version of e_scalb.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.
* ====================================================
*/
#include "fdlibm.h"
#include <limits.h>
#ifdef _SCALB_INT
#ifdef __STDC__
float __ieee754_scalbf(float x, int fn)
#else
float __ieee754_scalbf(x,fn)
float x; int fn;
#endif
#else
#ifdef __STDC__
float __ieee754_scalbf(float x, float fn)
#else
float __ieee754_scalbf(x,fn)
float x, fn;
#endif
#endif
{
#ifdef _SCALB_INT
return scalbnf(x,fn);
#else
if (isnan(x)||isnan(fn)) return x*fn;
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if (!finitef(fn)) {
if(fn>(float)0.0) return x*fn;
else return x/(-fn);
}
if (rintf(fn)!=fn) return (fn-fn)/(fn-fn);
#if INT_MAX > 65000
if ( fn > (float)65000.0) return scalbnf(x, 65000);
if (-fn > (float)65000.0) return scalbnf(x,-65000);
#else
if ( fn > (float)32000.0) return scalbnf(x, 32000);
if (-fn > (float)32000.0) return scalbnf(x,-32000);
#endif
return scalbnf(x,(int)fn);
#endif
}