mirror of git://sourceware.org/git/glibc.git
3e8814903c
The current approach tracks math maximum supported errors by explicitly setting them per function and architecture. On newer implementations or new compiler versions, the file is updated with newer values if it shows higher results. The idea is to track the maximum known error, to update the manual with the obtained values. The constant libm-test-ulps shows little value, where it is usually a mechanical change done by the maintainer, for past releases it is usually ignored whether the ulp change resulted from a compiler regression, and the math tests already have a maximum ulp error that triggers a regression. It was shown by a recent update after the new acosf [1] implementation that is correctly rounded, where the libm-test-ulps was indeed from a compiler issue. This patch removes all arch-specific libm-test-ulps, adds system generic libm-test-ulps where applicable, and changes its semantics. The generic files now track specific implementation constraints, like if it is expected to be correctly rounded, or if the system-specific has different error expectations. Now multiple libm-test-ulps can be defined, and system-specific overrides generic implementation. This is for the case where arch-specific implementation might show worse precision than generic implementation, for instance, the cbrtf on i686. Regressions are only reported if the implementation shows larger errors than 9 ulps (13 for IBM long double) unless it is overridden by libm-test-ulps and the maximum error is not printed at the end of tests. The regen-ulps rule is also removed since it does not make sense to update the libm-test-ulps automatically. The manual error table is also removed, Paul Zimmermann and others have been tracking libm precision with a more comprehensive analysis for some releases; so link to his work instead. [1] https://sourceware.org/git/?p=glibc.git;a=commit;h=9cc9f8e11e8fb8f54f1e84d9f024917634a78201 |
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| bits | ||
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| io | ||
| libio | ||
| locale | ||
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| login | ||
| mach | ||
| malloc | ||
| manual | ||
| math | ||
| mathvec | ||
| misc | ||
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| socket | ||
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| stdio-common | ||
| stdlib | ||
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| COPYING | ||
| COPYING.LIB | ||
| INSTALL | ||
| LICENSES | ||
| MAINTAINERS | ||
| Makeconfig | ||
| Makefile | ||
| Makefile.help | ||
| Makefile.in | ||
| Makerules | ||
| NEWS | ||
| README | ||
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| SECURITY.md | ||
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| configure | ||
| configure.ac | ||
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| gen-locales.mk | ||
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| 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.