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 1.10 2002/05/26 22:02:02 wiz 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 double 28 lgamma(double x) 29 { 30 #ifdef _IEEE_LIBM 31 return __ieee754_lgamma_r(x,&signgam); 32 #else 33 double y; 34 y = __ieee754_lgamma_r(x,&signgam); 35 if(_LIB_VERSION == _IEEE_) return y; 36 if(!finite(y)&&finite(x)) { 37 if(floor(x)==x&&x<=0.0) 38 return __kernel_standard(x,x,15); /* lgamma pole */ 39 else 40 return __kernel_standard(x,x,14); /* lgamma overflow */ 41 } else 42 return y; 43 #endif 44 } 45