glibc/sysdeps/libm-ieee754/w_powf.c

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/* w_powf.c -- float version of w_pow.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.
* ====================================================
*/
#if defined(LIBM_SCCS) && !defined(lint)
static char rcsid[] = "$NetBSD: w_powf.c,v 1.3 1995/05/10 20:49:41 jtc Exp $";
#endif
/*
* wrapper powf(x,y) return x**y
*/
#include "math.h"
#include "math_private.h"
#ifdef __STDC__
float __powf(float x, float y) /* wrapper powf */
#else
float __powf(x,y) /* wrapper powf */
float x,y;
#endif
{
#ifdef _IEEE_LIBM
return __ieee754_powf(x,y);
#else
float z;
z=__ieee754_powf(x,y);
if(_LIB_VERSION == _IEEE_|| __isnanf(y)) return z;
if(__isnanf(x)) {
if(y==(float)0.0)
/* powf(NaN,0.0) */
return (float)__kernel_standard((double)x,(double)y,142);
else
return z;
}
if(x==(float)0.0){
if(y==(float)0.0)
/* powf(0.0,0.0) */
return (float)__kernel_standard((double)x,(double)y,120);
if(__finitef(y)&&y<(float)0.0)
/* powf(0.0,negative) */
return (float)__kernel_standard((double)x,(double)y,123);
return z;
}
if(!__finitef(z)) {
if(__finitef(x)&&__finitef(y)) {
if(__isnanf(z))
/* powf neg**non-int */
return (float)__kernel_standard((double)x,(double)y,124);
else
/* powf overflow */
return (float)__kernel_standard((double)x,(double)y,121);
}
}
if(z==(float)0.0&&__finitef(x)&&__finitef(y))
/* powf underflow */
return (float)__kernel_standard((double)x,(double)y,122);
return z;
#endif
}
weak_alias (__powf, powf)