mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-01 01:00:10 +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
137 lines
3.3 KiB
C
137 lines
3.3 KiB
C
/* cbrtl.c
|
|
*
|
|
* Cube root, long double precision
|
|
*
|
|
*
|
|
*
|
|
* SYNOPSIS:
|
|
*
|
|
* long double x, y, cbrtl();
|
|
*
|
|
* y = cbrtl( x );
|
|
*
|
|
*
|
|
*
|
|
* DESCRIPTION:
|
|
*
|
|
* Returns the cube root of the argument, which may be negative.
|
|
*
|
|
* Range reduction involves determining the power of 2 of
|
|
* the argument. A polynomial of degree 2 applied to the
|
|
* mantissa, and multiplication by the cube root of 1, 2, or 4
|
|
* approximates the root to within about 0.1%. Then Newton's
|
|
* iteration is used three times to converge to an accurate
|
|
* result.
|
|
*
|
|
*
|
|
*
|
|
* ACCURACY:
|
|
*
|
|
* Relative error:
|
|
* arithmetic domain # trials peak rms
|
|
* IEEE -8,8 100000 1.3e-34 3.9e-35
|
|
* IEEE exp(+-707) 100000 1.3e-34 4.3e-35
|
|
*
|
|
*/
|
|
|
|
/*
|
|
Cephes Math Library Release 2.2: January, 1991
|
|
Copyright 1984, 1991 by Stephen L. Moshier
|
|
Adapted for glibc October, 2001.
|
|
|
|
This 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.
|
|
|
|
This 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 this library; if not, see
|
|
<https://www.gnu.org/licenses/>. */
|
|
|
|
|
|
#include <math.h>
|
|
#include <math_private.h>
|
|
#include <libm-alias-ldouble.h>
|
|
|
|
static const _Float128 CBRT2 = L(1.259921049894873164767210607278228350570251);
|
|
static const _Float128 CBRT4 = L(1.587401051968199474751705639272308260391493);
|
|
static const _Float128 CBRT2I = L(0.7937005259840997373758528196361541301957467);
|
|
static const _Float128 CBRT4I = L(0.6299605249474365823836053036391141752851257);
|
|
|
|
|
|
_Float128
|
|
__cbrtl (_Float128 x)
|
|
{
|
|
int e, rem, sign;
|
|
_Float128 z;
|
|
|
|
if (!isfinite (x))
|
|
return x + x;
|
|
|
|
if (x == 0)
|
|
return (x);
|
|
|
|
if (x > 0)
|
|
sign = 1;
|
|
else
|
|
{
|
|
sign = -1;
|
|
x = -x;
|
|
}
|
|
|
|
z = x;
|
|
/* extract power of 2, leaving mantissa between 0.5 and 1 */
|
|
x = __frexpl (x, &e);
|
|
|
|
/* Approximate cube root of number between .5 and 1,
|
|
peak relative error = 1.2e-6 */
|
|
x = ((((L(1.3584464340920900529734e-1) * x
|
|
- L(6.3986917220457538402318e-1)) * x
|
|
+ L(1.2875551670318751538055e0)) * x
|
|
- L(1.4897083391357284957891e0)) * x
|
|
+ L(1.3304961236013647092521e0)) * x + L(3.7568280825958912391243e-1);
|
|
|
|
/* exponent divided by 3 */
|
|
if (e >= 0)
|
|
{
|
|
rem = e;
|
|
e /= 3;
|
|
rem -= 3 * e;
|
|
if (rem == 1)
|
|
x *= CBRT2;
|
|
else if (rem == 2)
|
|
x *= CBRT4;
|
|
}
|
|
else
|
|
{ /* argument less than 1 */
|
|
e = -e;
|
|
rem = e;
|
|
e /= 3;
|
|
rem -= 3 * e;
|
|
if (rem == 1)
|
|
x *= CBRT2I;
|
|
else if (rem == 2)
|
|
x *= CBRT4I;
|
|
e = -e;
|
|
}
|
|
|
|
/* multiply by power of 2 */
|
|
x = __ldexpl (x, e);
|
|
|
|
/* Newton iteration */
|
|
x -= (x - (z / (x * x))) * L(0.3333333333333333333333333333333333333333);
|
|
x -= (x - (z / (x * x))) * L(0.3333333333333333333333333333333333333333);
|
|
x -= (x - (z / (x * x))) * L(0.3333333333333333333333333333333333333333);
|
|
|
|
if (sign < 0)
|
|
x = -x;
|
|
return (x);
|
|
}
|
|
|
|
libm_alias_ldouble (__cbrt, cbrt)
|