forked from KolibriOS/kolibrios
90 lines
1.9 KiB
C
90 lines
1.9 KiB
C
|
|
/* @(#)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 <reent.h>
|
|
#include <errno.h>
|
|
|
|
#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;
|
|
struct exception exc;
|
|
y = __ieee754_lgamma_r(x,&(_REENT_SIGNGAM(_REENT)));
|
|
if(_LIB_VERSION == _IEEE_) return y;
|
|
if(!finite(y)&&finite(x)) {
|
|
#ifndef HUGE_VAL
|
|
#define HUGE_VAL inf
|
|
double inf = 0.0;
|
|
|
|
SET_HIGH_WORD(inf,0x7ff00000); /* set inf to infinite */
|
|
#endif
|
|
exc.name = "lgamma";
|
|
exc.err = 0;
|
|
exc.arg1 = x;
|
|
exc.arg2 = x;
|
|
if (_LIB_VERSION == _SVID_)
|
|
exc.retval = HUGE;
|
|
else
|
|
exc.retval = HUGE_VAL;
|
|
if(floor(x)==x&&x<=0.0) {
|
|
/* lgamma(-integer) */
|
|
exc.type = SING;
|
|
if (_LIB_VERSION == _POSIX_)
|
|
errno = EDOM;
|
|
else if (!matherr(&exc)) {
|
|
errno = EDOM;
|
|
}
|
|
|
|
} else {
|
|
/* lgamma(finite) overflow */
|
|
exc.type = OVERFLOW;
|
|
if (_LIB_VERSION == _POSIX_)
|
|
errno = ERANGE;
|
|
else if (!matherr(&exc)) {
|
|
errno = ERANGE;
|
|
}
|
|
}
|
|
if (exc.err != 0)
|
|
errno = exc.err;
|
|
return exc.retval;
|
|
} else
|
|
return y;
|
|
#endif
|
|
}
|
|
|
|
#endif /* defined(_DOUBLE_IS_32BITS) */
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|