mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-02 17:50:20 +00:00
5a82c74822
Also, change sources.redhat.com to sourceware.org.
This patch was automatically generated by running the following shell
script, which uses GNU sed, and which avoids modifying files imported
from upstream:
sed -ri '
s,(http|ftp)(://(.*\.)?(gnu|fsf|sourceware)\.org($|[^.]|\.[^a-z])),https\2,g
s,(http|ftp)(://(.*\.)?)sources\.redhat\.com($|[^.]|\.[^a-z]),https\2sourceware.org\4,g
' \
$(find $(git ls-files) -prune -type f \
! -name '*.po' \
! -name 'ChangeLog*' \
! -path COPYING ! -path COPYING.LIB \
! -path manual/fdl-1.3.texi ! -path manual/lgpl-2.1.texi \
! -path manual/texinfo.tex ! -path scripts/config.guess \
! -path scripts/config.sub ! -path scripts/install-sh \
! -path scripts/mkinstalldirs ! -path scripts/move-if-change \
! -path INSTALL ! -path locale/programs/charmap-kw.h \
! -path po/libc.pot ! -path sysdeps/gnu/errlist.c \
! '(' -name configure \
-execdir test -f configure.ac -o -f configure.in ';' ')' \
! '(' -name preconfigure \
-execdir test -f preconfigure.ac ';' ')' \
-print)
and then by running 'make dist-prepare' to regenerate files built
from the altered files, and then executing the following to cleanup:
chmod a+x sysdeps/unix/sysv/linux/riscv/configure
# Omit irrelevant whitespace and comment-only changes,
# perhaps from a slightly-different Autoconf version.
git checkout -f \
sysdeps/csky/configure \
sysdeps/hppa/configure \
sysdeps/riscv/configure \
sysdeps/unix/sysv/linux/csky/configure
# Omit changes that caused a pre-commit check to fail like this:
# remote: *** error: sysdeps/powerpc/powerpc64/ppc-mcount.S: trailing lines
git checkout -f \
sysdeps/powerpc/powerpc64/ppc-mcount.S \
sysdeps/unix/sysv/linux/s390/s390-64/syscall.S
# Omit change that caused a pre-commit check to fail like this:
# remote: *** error: sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S: last line does not end in newline
git checkout -f sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S
97 lines
2.7 KiB
C
97 lines
2.7 KiB
C
/* Single-precision 2^x function.
|
|
Copyright (C) 2017-2019 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Lesser General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2.1 of the License, or (at your option) any later version.
|
|
|
|
The GNU C Library is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
License along with the GNU C Library; if not, see
|
|
<https://www.gnu.org/licenses/>. */
|
|
|
|
#include <math.h>
|
|
#include <math-narrow-eval.h>
|
|
#include <stdint.h>
|
|
#include <shlib-compat.h>
|
|
#include <libm-alias-float.h>
|
|
#include "math_config.h"
|
|
|
|
/*
|
|
EXP2F_TABLE_BITS = 5
|
|
EXP2F_POLY_ORDER = 3
|
|
|
|
ULP error: 0.502 (nearest rounding.)
|
|
Relative error: 1.69 * 2^-34 in [-1/64, 1/64] (before rounding.)
|
|
Wrong count: 168353 (all nearest rounding wrong results with fma.)
|
|
Non-nearest ULP error: 1 (rounded ULP error)
|
|
*/
|
|
|
|
#define N (1 << EXP2F_TABLE_BITS)
|
|
#define T __exp2f_data.tab
|
|
#define C __exp2f_data.poly
|
|
#define SHIFT __exp2f_data.shift_scaled
|
|
|
|
static inline uint32_t
|
|
top12 (float x)
|
|
{
|
|
return asuint (x) >> 20;
|
|
}
|
|
|
|
float
|
|
__exp2f (float x)
|
|
{
|
|
uint32_t abstop;
|
|
uint64_t ki, t;
|
|
/* double_t for better performance on targets with FLT_EVAL_METHOD==2. */
|
|
double_t kd, xd, z, r, r2, y, s;
|
|
|
|
xd = (double_t) x;
|
|
abstop = top12 (x) & 0x7ff;
|
|
if (__glibc_unlikely (abstop >= top12 (128.0f)))
|
|
{
|
|
/* |x| >= 128 or x is nan. */
|
|
if (asuint (x) == asuint (-INFINITY))
|
|
return 0.0f;
|
|
if (abstop >= top12 (INFINITY))
|
|
return x + x;
|
|
if (x > 0.0f)
|
|
return __math_oflowf (0);
|
|
if (x <= -150.0f)
|
|
return __math_uflowf (0);
|
|
#if WANT_ERRNO_UFLOW
|
|
if (x < -149.0f)
|
|
return __math_may_uflowf (0);
|
|
#endif
|
|
}
|
|
|
|
/* x = k/N + r with r in [-1/(2N), 1/(2N)] and int k. */
|
|
kd = math_narrow_eval ((double) (xd + SHIFT)); /* Needs to be double. */
|
|
ki = asuint64 (kd);
|
|
kd -= SHIFT; /* k/N for int k. */
|
|
r = xd - kd;
|
|
|
|
/* exp2(x) = 2^(k/N) * 2^r ~= s * (C0*r^3 + C1*r^2 + C2*r + 1) */
|
|
t = T[ki % N];
|
|
t += ki << (52 - EXP2F_TABLE_BITS);
|
|
s = asdouble (t);
|
|
z = C[0] * r + C[1];
|
|
r2 = r * r;
|
|
y = C[2] * r + 1;
|
|
y = z * r2 + y;
|
|
y = y * s;
|
|
return (float) y;
|
|
}
|
|
#ifndef __exp2f
|
|
strong_alias (__exp2f, __ieee754_exp2f)
|
|
strong_alias (__exp2f, __exp2f_finite)
|
|
versioned_symbol (libm, __exp2f, exp2f, GLIBC_2_27);
|
|
libm_alias_float_other (__exp2, exp2)
|
|
#endif
|