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Diffstat (limited to 'libm/w_gamma.c')
-rw-r--r-- | libm/w_gamma.c | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/libm/w_gamma.c b/libm/w_gamma.c new file mode 100644 index 000000000..59fe8f640 --- /dev/null +++ b/libm/w_gamma.c @@ -0,0 +1,49 @@ +/* @(#)w_gamma.c 5.1 93/09/24 */ +/* + * ==================================================== + * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. + * + * Developed at SunPro, a Sun Microsystems, Inc. business. + * Permission to use, copy, modify, and distribute this + * software is freely granted, provided that this notice + * is preserved. + * ==================================================== + */ + +#if defined(LIBM_SCCS) && !defined(lint) +static char rcsid[] = "$NetBSD: w_gamma.c,v 1.7 1995/11/20 22:06:43 jtc Exp $"; +#endif + +/* double gamma(double x) + * Return the logarithm of the Gamma function of x. + * + * Method: call gamma_r + */ + +#include "math.h" +#include "math_private.h" + +extern int signgam; + +#ifdef __STDC__ + double gamma(double x) +#else + double gamma(x) + double x; +#endif +{ +#ifdef _IEEE_LIBM + return __ieee754_lgamma_r(x,&signgam); +#else + double y; + y = __ieee754_lgamma_r(x,&signgam); + if(_LIB_VERSION == _IEEE_) return y; + if(!finite(y)&&finite(x)) { + if(floor(x)==x&&x<=0.0) + return __kernel_standard(x,x,41); /* gamma pole */ + else + return __kernel_standard(x,x,40); /* gamma overflow */ + } else + return y; +#endif +} |