/* * ==================================================== * 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 gamma(double x) * Return the logarithm of the Gamma function of x or the Gamma function of x, * depending on the library mode. */ #include "math.h" #include "math_private.h" double tgamma(double x) { double y; int local_signgam; y = __ieee754_gamma_r(x, &local_signgam); if (local_signgam < 0) y = -y; #ifndef _IEEE_LIBM if (_LIB_VERSION == _IEEE_) return y; if (!isfinite(y) && isfinite(x)) { if (floor(x) == x && x <= 0.0) return __kernel_standard(x, x, 41); /* tgamma pole */ return __kernel_standard(x, x, 40); /* tgamma overflow */ } #endif return y; } libm_hidden_def(tgamma)