diff options
Diffstat (limited to 'libm/w_tgamma.c')
-rw-r--r-- | libm/w_tgamma.c | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/libm/w_tgamma.c b/libm/w_tgamma.c new file mode 100644 index 000000000..0bacff16b --- /dev/null +++ b/libm/w_tgamma.c @@ -0,0 +1,47 @@ +/* @(#)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. + * ==================================================== + */ + +/* 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" +#if __UCLIBC_HAS_FENV__ +#include <errno.h> +#endif + +double +tgamma(double x) +{ +#if __UCLIBC_HAS_FENV__ + double y = __ieee754_tgamma(x); + + if(__builtin_expect (!isfinite (y) || y == 0, 0) + && (isfinite (x) || (isinf (x) && x < 0.0)) + && _LIB_VERSION != _IEEE_) { + if (x == 0.0) + return __kernel_standard(x,x,50); /* tgamma pole */ + else if(floor(x)==x&&x<0.0) + return __kernel_standard(x,x,41); /* tgamma domain */ + else if (y == 0) + __set_errno (ERANGE); /* tgamma underflow */ + else + return __kernel_standard(x,x,40); /* tgamma overflow */ + } + return y; +#else + return __ieee754_tgamma(x); +#endif +} +libm_hidden_def(tgamma); |