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57 lines
1.4 KiB
C
57 lines
1.4 KiB
C
/* @(#)w_gamma.c 5.1 93/09/24 */
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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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#if defined(LIBM_SCCS) && !defined(lint)
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static char rcsid[] = "$NetBSD: w_gamma.c,v 1.7 1995/11/20 22:06:43 jtc Exp $";
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#endif
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/* double gamma(double x)
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* Return the logarithm of the Gamma function of x or the Gamma function of x,
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* depending on the library mode.
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*/
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#include "math.h"
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#include "math_private.h"
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#ifdef __STDC__
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double __tgamma(double x)
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#else
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double __tgamma(x)
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double x;
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#endif
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{
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double y;
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int local_signgam;
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y = __ieee754_gamma_r(x,&local_signgam);
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if (local_signgam < 0) y = -y;
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#ifdef _IEEE_LIBM
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return y;
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#else
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if(_LIB_VERSION == _IEEE_) return y;
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if(!__finite(y)&&__finite(x)) {
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if (x == 0.0)
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return __kernel_standard(x,x,50); /* tgamma pole */
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else if(__floor(x)==x&&x<0.0)
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return __kernel_standard(x,x,41); /* tgamma domain */
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else
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return __kernel_standard(x,x,40); /* tgamma overflow */
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}
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return y;
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#endif
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}
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weak_alias (__tgamma, tgamma)
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#ifdef NO_LONG_DOUBLE
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strong_alias (__tgamma, __tgammal)
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weak_alias (__tgamma, tgammal)
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#endif
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