mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-30 08:40:07 +00:00
4699cb8b5f
This patch makes dbl-64 logb use libm_alias_double. Both the dbl-64 and dbl-64/wordsize-64 versions are changed, and the ldbl-opt version is removed. Because of multiarch wrappers, the changed implementations are made not to define aliases at all if __logb is defined as a macro, as with other functions, so avoiding duplicate compat symbols while allowing those wrappers to be simplified. Tested for x86_64, and verified with build-many-glibcs.py that installed stripped shared libraries are unchanged (except on alpha where changes from using the wordsize-64 version are expected). * sysdeps/ieee754/dbl-64/s_logb.c: Include <libm-alias-double.h>. (logb): Define using libm_alias_double, only if [!__logb]. * sysdeps/ieee754/dbl-64/wordsize-64/s_logb.c: Include <libm-alias-double.h>. (logb): Define using libm_alias_double, only if [!__logb]. * sysdeps/ieee754/ldbl-opt/s_logb.c: Remove file. * sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_logb-ppc32.c (weak_alias): Do not undefine and redefine. (strong_alias): Likewise. * sysdeps/powerpc/powerpc64/fpu/multiarch/s_logb-ppc64.c (weak_alias): Likewise. (strong_alias): Likewise.
53 lines
1.3 KiB
C
53 lines
1.3 KiB
C
/* @(#)s_logb.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 logb(x)
|
|
* IEEE 754 logb. Included to pass IEEE test suite. Not recommend.
|
|
* Use ilogb instead.
|
|
*/
|
|
|
|
#include <math.h>
|
|
#include <math_private.h>
|
|
#include <libm-alias-double.h>
|
|
#include <fix-int-fp-convert-zero.h>
|
|
|
|
double
|
|
__logb (double x)
|
|
{
|
|
int32_t lx, ix, rix;
|
|
|
|
EXTRACT_WORDS (ix, lx, x);
|
|
ix &= 0x7fffffff; /* high |x| */
|
|
if ((ix | lx) == 0)
|
|
return -1.0 / fabs (x);
|
|
if (ix >= 0x7ff00000)
|
|
return x * x;
|
|
if (__glibc_unlikely ((rix = ix >> 20) == 0))
|
|
{
|
|
/* POSIX specifies that denormal number is treated as
|
|
though it were normalized. */
|
|
int ma;
|
|
if (ix == 0)
|
|
ma = __builtin_clz (lx) + 32;
|
|
else
|
|
ma = __builtin_clz (ix);
|
|
rix -= ma - 12;
|
|
}
|
|
if (FIX_INT_FP_CONVERT_ZERO && rix == 1023)
|
|
return 0.0;
|
|
return (double) (rix - 1023);
|
|
}
|
|
#ifndef __logb
|
|
libm_alias_double (__logb, logb)
|
|
#endif
|