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Diffstat (limited to 'libm/src/w_lgamma.c')
-rw-r--r-- | libm/src/w_lgamma.c | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/libm/src/w_lgamma.c b/libm/src/w_lgamma.c new file mode 100644 index 0000000..2c12b31 --- /dev/null +++ b/libm/src/w_lgamma.c @@ -0,0 +1,46 @@ + +/* @(#)w_lgamma.c 1.3 95/01/18 */ +/* + * ==================================================== + * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. + * + * Developed at SunSoft, 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" + +extern int signgam; + +#ifdef __STDC__ + double lgamma(double x) +#else + double lgamma(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,15); /* lgamma pole */ + else + return __kernel_standard(x,x,14); /* lgamma overflow */ + } else + return y; +#endif +} |