mirror of
git://sourceware.org/git/newlib-cygwin.git
synced 2025-01-19 12:59:21 +08:00
1f8e5847df
The current gamma, gamma_r, gammaf and gammaf_r functions return
|gamma(x)| instead of ln(|gamma(x)|) due to a change made back in 2002
to the __ieee754_gamma_r implementation. This patch fixes that, making
all of these functions map too their lgamma equivalents.
To fix the underlying bug, the __ieee754_gamma functions have been
changed to return gamma(x), removing the _r variants as those are no
longer necessary. Their names have been changed to __ieee754_tgamma to
avoid potential confusion from users.
Now that the __ieee754_tgamma functions return the correctly signed
value, the tgamma functions have been modified to use them.
libm.a now exposes the following gamma functions:
ln(|gamma(x)|):
__ieee754_lgamma_r
__ieee754_lgammaf_r
lgamma
lgamma_r
gamma
gamma_r
lgammaf
lgammaf_r
gammaf
gammaf_r
lgammal (on machines where long double is double)
gamma(x):
__ieee754_tgamma
__ieee754_tgammaf
tgamma
tgammaf
tgammal (on machines where long double is double)
Additional aliases for any of the above functions can be added if
necessary; in particular, I'm not sure if we need to include
__ieee754_gamma*_r functions (which would return ln(|(gamma(x)|).
Signed-off-by: Keith Packard <keithp@keithp.com>
----
v2:
Switch commit message to ASCII
48 lines
1.2 KiB
C
48 lines
1.2 KiB
C
/* wrf_lgamma.c -- float version of wr_lgamma.c.
|
|
* Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
|
|
*/
|
|
|
|
/*
|
|
* ====================================================
|
|
* 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.
|
|
* ====================================================
|
|
*/
|
|
|
|
/*
|
|
* wrapper float lgammaf_r(float x, int *signgamp)
|
|
*/
|
|
|
|
#include "fdlibm.h"
|
|
#include <errno.h>
|
|
|
|
#ifdef __STDC__
|
|
float lgammaf_r(float x, int *signgamp) /* wrapper lgammaf_r */
|
|
#else
|
|
float lgammaf_r(x,signgamp) /* wrapper lgammaf_r */
|
|
float x; int *signgamp;
|
|
#endif
|
|
{
|
|
#ifdef _IEEE_LIBM
|
|
return __ieee754_lgammaf_r(x,signgamp);
|
|
#else
|
|
float y;
|
|
y = __ieee754_lgammaf_r(x,signgamp);
|
|
if(_LIB_VERSION == _IEEE_) return y;
|
|
if(!finitef(y)&&finitef(x)) {
|
|
if(floorf(x)==x&&x<=0.0f) {
|
|
/* lgammaf(-integer) or lgamma(0) */
|
|
errno = EDOM;
|
|
} else {
|
|
/* lgammaf(finite) overflow */
|
|
errno = ERANGE;
|
|
}
|
|
}
|
|
return y;
|
|
#endif
|
|
}
|