/* @(#)w_lgamma.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. * ==================================================== * */ /* double lgamma(double x) * Return the logarithm of the Gamma function of x. * * Method: call __ieee754_lgamma_r */ #include "fdlibm.h" #include #include #ifndef _DOUBLE_IS_32BITS #ifdef __STDC__ double lgamma(double x) #else double lgamma(x) double x; #endif { #ifdef _IEEE_LIBM return __ieee754_lgamma_r(x,&(_REENT_SIGNGAM(_REENT))); #else double y; y = __ieee754_lgamma_r(x,&(_REENT_SIGNGAM(_REENT))); if(_LIB_VERSION == _IEEE_) return y; if(!finite(y)&&finite(x)) { if(floor(x)==x&&x<=0.0) /* lgamma(-integer) */ errno = EDOM; else /* lgamma(finite) overflow */ errno = ERANGE; return HUGE_VAL; } else return y; #endif } #endif /* defined(_DOUBLE_IS_32BITS) */