mirror of git://sourceware.org/git/glibc.git
The current implementation precision shows the following accuracy, on
one range ([-20,20]) with 10e9 uniform randomly generated numbers for
each range (first column is the accuracy in ULP, with '0' being
correctly rounded, second is the number of samples with the
corresponding precision):
* Range [-20,20]
* FE_TONEAREST
0: 4504877808 45.05%
1: 4402224940 44.02%
2: 947652295 9.48%
3: 131076831 1.31%
4: 13222216 0.13%
5: 910045 0.01%
6: 35253 0.00%
7: 606 0.00%
8: 6 0.00%
* FE_UPWARD
0: 3477307921 34.77%
1: 4838637866 48.39%
2: 1413942684 14.14%
3: 240762564 2.41%
4: 27113094 0.27%
5: 2130934 0.02%
6: 102599 0.00%
7: 2324 0.00%
8: 14 0.00%
* FE_DOWNWARD
0: 3923545410 39.24%
1: 4745067290 47.45%
2: 1137899814 11.38%
3: 171596912 1.72%
4: 20013805 0.20%
5: 1773899 0.02%
6: 99911 0.00%
7: 2928 0.00%
8: 31 0.00%
* FE_TOWARDZERO
0: 3697160741 36.97%
1: 4731951491 47.32%
2: 1303092738 13.03%
3: 231969191 2.32%
4: 32344517 0.32%
5: 3283092 0.03%
6: 193010 0.00%
7: 5175 0.00%
8: 45 0.00%
The CORE-MATH implementation is correctly rounded for any rounding mode.
The code was adapted to glibc style and to use the definition of
math_config.h (to handle errno, overflow, and underflow).
Benchtest on x64_64 (Ryzen 9 5900X, gcc 14.2.1), aarch64 (Neoverse-N1,
gcc 13.3.1), and powerpc (POWER10, gcc 13.2.1) shows:
reciprocal-throughput master patched improvement
x86_64 237.7960 175.4090 26.24%
x86_64v2 232.9320 163.4460 29.83%
x86_64v3 193.0680 89.7721 53.50%
aarch64 113.6340 56.7350 50.07%
power10 92.0617 26.6137 71.09%
Latency master patched improvement
x86_64 266.7190 208.0130 22.01%
x86_64v2 263.6070 200.0280 24.12%
x86_64v3 214.0260 146.5180 31.54%
aarch64 114.4760 58.5235 48.88%
power10 84.3718 35.7473 57.63%
Checked on x86_64-linux-gnu, aarch64-linux-gnu, and
powerpc64le-linux-gnu.
Reviewed-by: DJ Delorie <dj@redhat.com>
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| ChangeLog.old | ||
| advisories | ||
| argp | ||
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| bits | ||
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| htl | ||
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| time | ||
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| wcsmbs | ||
| wctype | ||
| .b4-config | ||
| .clang-format | ||
| .gitattributes | ||
| .gitignore | ||
| CONTRIBUTED-BY | ||
| COPYING | ||
| COPYING.LIB | ||
| INSTALL | ||
| LICENSES | ||
| MAINTAINERS | ||
| Makeconfig | ||
| Makefile | ||
| Makefile.help | ||
| Makefile.in | ||
| Makerules | ||
| NEWS | ||
| README | ||
| Rules | ||
| SECURITY.md | ||
| SHARED-FILES | ||
| abi-tags | ||
| aclocal.m4 | ||
| config.h.in | ||
| config.make.in | ||
| configure | ||
| configure.ac | ||
| extra-lib.mk | ||
| gen-locales.mk | ||
| libc-abis | ||
| libof-iterator.mk | ||
| o-iterator.mk | ||
| shlib-versions | ||
| test-skeleton.c | ||
| version.h | ||
README
This directory contains the sources of the GNU C Library. See the file "version.h" for what release version you have. The GNU C Library is the standard system C library for all GNU systems, and is an important part of what makes up a GNU system. It provides the system API for all programs written in C and C-compatible languages such as C++ and Objective C; the runtime facilities of other programming languages use the C library to access the underlying operating system. In GNU/Linux systems, the C library works with the Linux kernel to implement the operating system behavior seen by user applications. In GNU/Hurd systems, it works with a microkernel and Hurd servers. The GNU C Library implements much of the POSIX.1 functionality in the GNU/Hurd system, using configurations i[4567]86-*-gnu and x86_64-gnu. When working with Linux kernels, this version of the GNU C Library requires Linux kernel version 3.2 or later. Also note that the shared version of the libgcc_s library must be installed for the pthread library to work correctly. The GNU C Library supports these configurations for using Linux kernels: aarch64*-*-linux-gnu alpha*-*-linux-gnu arc*-*-linux-gnu arm-*-linux-gnueabi csky-*-linux-gnuabiv2 hppa-*-linux-gnu i[4567]86-*-linux-gnu x86_64-*-linux-gnu Can build either x86_64 or x32 loongarch64-*-linux-gnu Hardware floating point, LE only. m68k-*-linux-gnu microblaze*-*-linux-gnu mips-*-linux-gnu mips64-*-linux-gnu or1k-*-linux-gnu powerpc-*-linux-gnu Hardware or software floating point, BE only. powerpc64*-*-linux-gnu Big-endian and little-endian. s390-*-linux-gnu s390x-*-linux-gnu riscv32-*-linux-gnu riscv64-*-linux-gnu sh[34]-*-linux-gnu sparc*-*-linux-gnu sparc64*-*-linux-gnu If you are interested in doing a port, please contact the glibc maintainers; see https://www.gnu.org/software/libc/ for more information. See the file INSTALL to find out how to configure, build, and install the GNU C Library. You might also consider reading the WWW pages for the C library at https://www.gnu.org/software/libc/. The GNU C Library is (almost) completely documented by the Texinfo manual found in the `manual/' subdirectory. The manual is still being updated and contains some known errors and omissions; we regret that we do not have the resources to work on the manual as much as we would like. For corrections to the manual, please file a bug in the `manual' component, following the bug-reporting instructions below. Please be sure to check the manual in the current development sources to see if your problem has already been corrected. Please see https://www.gnu.org/software/libc/bugs.html for bug reporting information. We are now using the Bugzilla system to track all bug reports. This web page gives detailed information on how to report bugs properly. The GNU C Library is free software. See the file COPYING.LIB for copying conditions, and LICENSES for notices about a few contributions that require these additional notices to be distributed. License copyright years may be listed using range notation, e.g., 1996-2015, indicating that every year in the range, inclusive, is a copyrightable year that would otherwise be listed individually.