support/fdlibm/w_gamma.c
author Jan Vrany <jan.vrany@fit.cvut.cz>
Wed, 23 Jan 2013 12:31:33 +0000
branchdevelopment
changeset 1988 0fcf5a5dcb66
parent 1818 2e5ed72e7dfd
child 2380 9195eccdcbd9
permissions -rw-r--r--
Cleanup in JavaRelease: javaHome/jreHome/jdkHome.
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/* @(#)w_gamma.c 1.3 95/01/18 */
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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 SunSoft, 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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 */
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/* double gamma(double x)
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 * Return the logarithm of the Gamma function of x.
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 *
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 * Method: call gamma_r
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 */
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#include "fdlibm.h"
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extern int signgam;
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#ifdef __STDC__
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	double gamma(double x)
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#else
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	double gamma(x)
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	double x;
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#endif
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{
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#ifdef _IEEE_LIBM
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	return __ieee754_gamma_r(x,&signgam);
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#else
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        double y;
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        y = __ieee754_gamma_r(x,&signgam);
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        if(_LIB_VERSION == _IEEE_) return y;
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        if(!finite(y)&&finite(x)) {
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            if(floor(x)==x&&x<=0.0)
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                return __kernel_standard(x,x,41); /* gamma pole */
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            else
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                return __kernel_standard(x,x,40); /* gamma overflow */
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        } else
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            return y;
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#endif
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}