mirror of git://sourceware.org/git/glibc.git
30e66b085c
The current implementation precision shows the following accuracy, on
tthree different ranges ([-DBL_MAX, -10], [-10,10], and [10, DBL_MAX))
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 [-DBL_MAX, -10]
* FE_TONEAREST
0: 5164019099 51.64%
1: 4835980901 48.36%
* FE_UPWARD
1: 4836053540 48.36%
2: 5163946460 51.64%
* FE_DOWNWARD
1: 5163926134 51.64%
2: 4836073866 48.36%
* FE_TOWARDZERO
0: 5163937001 51.64%
1: 4836062999 48.36%
* Range [-10, 10)
* FE_TONEAREST
0: 8679029381 86.79%
1: 1320934581 13.21%
2: 36038 0.00%
* FE_UPWARD
0: 3965704277 39.66%
1: 4993616710 49.94%
2: 1039680225 10.40%
3: 998788 0.01%
* FE_DOWNWARD
0: 3965806523 39.66%
1: 4993534438 49.94%
2: 1039601726 10.40%
3: 1057313 0.01%
* FE_TOWARDZEROA
0: 7734210130 77.34%
1: 2261868439 22.62%
2: 3921431 0.04%
* Range [10, DBL_MAX)
* FE_TONEAREST
0: 5163973212 51.64%
1: 4836026788 48.36%
* FE_UPWARD
0: 4835991071 48.36%
1: 5164008929 51.64%
* FE_DOWNWARD
0: 5163983594 51.64%
1: 4836016406 48.36%
* FE_TOWARDZERO
0: 5163993394 51.64%
1: 4836006606 48.36%
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 26.5178 45.3754 -71.11%
x86_64v2 26.3167 44.7870 -70.18%
x86_64v3 25.9109 25.4887 1.63%
aarch64 18.0555 17.3374 3.98%
power10 19.8535 20.5586 -3.55%
Latency master patched improvement
x86_64 82.6755 91.2026 -10.31%
x86_64v2 82.4581 90.7152 -10.01%
x86_64v3 80.7000 71.9454 10.85%
aarch64 32.8320 28.8565 12.11%
power10 44.5309 37.0096 16.89%
For x86_64/x86_64-v2, most performance hit came from the fma call
through the ifunc mechanism.
Checked on x86_64-linux-gnu, aarch64-linux-gnu, and
powerpc64le-linux-gnu.
Reviewed-by: DJ Delorie <dj@redhat.com>
|
||
|---|---|---|
| ChangeLog.old | ||
| advisories | ||
| argp | ||
| assert | ||
| benchtests | ||
| bits | ||
| catgets | ||
| conform | ||
| csu | ||
| ctype | ||
| debug | ||
| dirent | ||
| dlfcn | ||
| elf | ||
| gmon | ||
| gnulib | ||
| hesiod | ||
| htl | ||
| hurd | ||
| iconv | ||
| iconvdata | ||
| include | ||
| inet | ||
| intl | ||
| io | ||
| libio | ||
| locale | ||
| localedata | ||
| login | ||
| mach | ||
| malloc | ||
| manual | ||
| math | ||
| mathvec | ||
| misc | ||
| nis | ||
| nptl | ||
| nptl_db | ||
| nscd | ||
| nss | ||
| po | ||
| posix | ||
| resolv | ||
| resource | ||
| rt | ||
| scripts | ||
| setjmp | ||
| signal | ||
| socket | ||
| soft-fp | ||
| stdio-common | ||
| stdlib | ||
| string | ||
| sunrpc | ||
| support | ||
| sysdeps | ||
| sysvipc | ||
| termios | ||
| time | ||
| timezone | ||
| 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.