1 /* @(#)w_lgamma.c 5.1 93/09/24 */ 2 /* 3 * ==================================================== 4 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. 5 * 6 * Developed at SunPro, a Sun Microsystems, Inc. business. 7 * Permission to use, copy, modify, and distribute this 8 * software is freely granted, provided that this notice 9 * is preserved. 10 * ==================================================== 11 */ 12 13 #include <sys/cdefs.h> 14 #if defined(LIBM_SCCS) && !defined(lint) 15 __RCSID("$NetBSD: w_lgamma.c,v 1.9 2001/01/06 00:15:00 christos Exp $"); 16 #endif 17 18 /* double lgamma(double x) 19 * Return the logarithm of the Gamma function of x. 20 * 21 * Method: call __ieee754_lgamma_r 22 */ 23 24 #include "math.h" 25 #include "math_private.h" 26 27 #ifdef __STDC__ 28 double lgamma(double x) 29 #else 30 double lgamma(x) 31 double x; 32 #endif 33 { 34 #ifdef _IEEE_LIBM 35 return __ieee754_lgamma_r(x,&signgam); 36 #else 37 double y; 38 y = __ieee754_lgamma_r(x,&signgam); 39 if(_LIB_VERSION == _IEEE_) return y; 40 if(!finite(y)&&finite(x)) { 41 if(floor(x)==x&&x<=0.0) 42 return __kernel_standard(x,x,15); /* lgamma pole */ 43 else 44 return __kernel_standard(x,x,14); /* lgamma overflow */ 45 } else 46 return y; 47 #endif 48 } 49