50 lines
1.3 KiB
C
50 lines
1.3 KiB
C
/* @(#)w_lgamma.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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/* double lgamma(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 __ieee754_lgamma_r
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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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__lgamma(double x)
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{
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int local_signgam = 0;
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double y = __ieee754_lgamma_r(x,
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_LIB_VERSION != _ISOC_
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/* ISO C99 does not define the
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global variable. */
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? &signgam
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: &local_signgam);
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if(__builtin_expect(!__finite(y), 0)
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&& __finite(x) && _LIB_VERSION != _IEEE_)
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return __kernel_standard(x, x,
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__floor(x)==x&&x<=0.0
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? 15 /* lgamma pole */
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: 14); /* lgamma overflow */
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return y;
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}
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weak_alias (__lgamma, lgamma)
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strong_alias (__lgamma, __gamma)
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weak_alias (__gamma, gamma)
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#ifdef NO_LONG_DOUBLE
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strong_alias (__lgamma, __lgammal)
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weak_alias (__lgamma, lgammal)
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strong_alias (__gamma, __gammal)
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weak_alias (__gamma, gammal)
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#endif
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