This work is based in part on code from NetBSD libm, libc and kernel. The library is partly public domain and partly BSD-style licensed.
63 lines
1.5 KiB
C
63 lines
1.5 KiB
C
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/* @(#)w_pow.c 5.2 93/10/01 */
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/*
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* ====================================================
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* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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*
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* Developed at SunPro, a Sun Microsystems, Inc. business.
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* Permission to use, copy, modify, and distribute this
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* software is freely granted, provided that this notice
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* is preserved.
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* ====================================================
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*/
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#include <sys/cdefs.h>
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#if defined(LIBM_SCCS) && !defined(lint)
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__RCSID("$NetBSD: w_pow.c,v 1.7 2002/05/26 22:02:02 wiz Exp $");
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#endif
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/*
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* wrapper pow(x,y) return x**y
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*/
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#include "math.h"
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#include "math_private.h"
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double
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pow(double x, double y) /* wrapper pow */
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{
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#ifdef _IEEE_LIBM
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return __ieee754_pow(x,y);
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#else
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double z;
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z=__ieee754_pow(x,y);
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if(_LIB_VERSION == _IEEE_|| isnan(y)) return z;
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if(isnan(x)) {
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if(y==0.0)
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return __kernel_standard(x,y,42); /* pow(NaN,0.0) */
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else
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return z;
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}
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if(x==0.0){
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if(y==0.0)
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return __kernel_standard(x,y,20); /* pow(0.0,0.0) */
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if(finite(y)&&y<0.0)
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return __kernel_standard(x,y,23); /* pow(0.0,negative) */
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return z;
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}
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if(!finite(z)) {
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if(finite(x)&&finite(y)) {
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if(isnan(z))
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return __kernel_standard(x,y,24); /* pow neg**non-int */
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else
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return __kernel_standard(x,y,21); /* pow overflow */
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}
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}
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if(z==0.0&&finite(x)&&finite(y))
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return __kernel_standard(x,y,22); /* pow underflow */
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return z;
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#endif
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}
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