glibc/sysdeps/powerpc/cpu-features.c

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powerpc: POWER8 memcpy optimization for cached memory On POWER8, unaligned memory accesses to cached memory has little impact on performance as opposed to its ancestors. It is disabled by default and will only be available when the tunable glibc.tune.cached_memopt is set to 1. __memcpy_power8_cached __memcpy_power7 ============================================================ max-size=4096: 33325.70 ( 12.65%) 38153.00 max-size=8192: 32878.20 ( 11.17%) 37012.30 max-size=16384: 33782.20 ( 11.61%) 38219.20 max-size=32768: 33296.20 ( 11.30%) 37538.30 max-size=65536: 33765.60 ( 10.53%) 37738.40 * manual/tunables.texi (Hardware Capability Tunables): Document glibc.tune.cached_memopt. * sysdeps/powerpc/cpu-features.c: New file. * sysdeps/powerpc/cpu-features.h: New file. * sysdeps/powerpc/dl-procinfo.c [!IS_IN(ldconfig)]: Add _dl_powerpc_cpu_features. * sysdeps/powerpc/dl-tunables.list: New file. * sysdeps/powerpc/ldsodefs.h: Include cpu-features.h. * sysdeps/powerpc/powerpc32/power4/multiarch/init-arch.h (INIT_ARCH): Initialize use_aligned_memopt. * sysdeps/powerpc/powerpc64/dl-machine.h [defined(SHARED && IS_IN(rtld))]: Restrict dl_platform_init availability and initialize CPU features used by tunables. * sysdeps/powerpc/powerpc64/multiarch/Makefile (sysdep_routines): Add memcpy-power8-cached. * sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c: Add __memcpy_power8_cached. * sysdeps/powerpc/powerpc64/multiarch/memcpy.c: Likewise. * sysdeps/powerpc/powerpc64/multiarch/memcpy-power8-cached.S: New file. Reviewed-by: Rajalakshmi Srinivasaraghavan <raji@linux.vnet.ibm.com>
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/* Initialize cpu feature data. PowerPC version.
Copyright (C) 2017-2022 Free Software Foundation, Inc.
powerpc: POWER8 memcpy optimization for cached memory On POWER8, unaligned memory accesses to cached memory has little impact on performance as opposed to its ancestors. It is disabled by default and will only be available when the tunable glibc.tune.cached_memopt is set to 1. __memcpy_power8_cached __memcpy_power7 ============================================================ max-size=4096: 33325.70 ( 12.65%) 38153.00 max-size=8192: 32878.20 ( 11.17%) 37012.30 max-size=16384: 33782.20 ( 11.61%) 38219.20 max-size=32768: 33296.20 ( 11.30%) 37538.30 max-size=65536: 33765.60 ( 10.53%) 37738.40 * manual/tunables.texi (Hardware Capability Tunables): Document glibc.tune.cached_memopt. * sysdeps/powerpc/cpu-features.c: New file. * sysdeps/powerpc/cpu-features.h: New file. * sysdeps/powerpc/dl-procinfo.c [!IS_IN(ldconfig)]: Add _dl_powerpc_cpu_features. * sysdeps/powerpc/dl-tunables.list: New file. * sysdeps/powerpc/ldsodefs.h: Include cpu-features.h. * sysdeps/powerpc/powerpc32/power4/multiarch/init-arch.h (INIT_ARCH): Initialize use_aligned_memopt. * sysdeps/powerpc/powerpc64/dl-machine.h [defined(SHARED && IS_IN(rtld))]: Restrict dl_platform_init availability and initialize CPU features used by tunables. * sysdeps/powerpc/powerpc64/multiarch/Makefile (sysdep_routines): Add memcpy-power8-cached. * sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c: Add __memcpy_power8_cached. * sysdeps/powerpc/powerpc64/multiarch/memcpy.c: Likewise. * sysdeps/powerpc/powerpc64/multiarch/memcpy-power8-cached.S: New file. Reviewed-by: Rajalakshmi Srinivasaraghavan <raji@linux.vnet.ibm.com>
2017-12-11 19:39:42 +00:00
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
Prefer https to http for gnu.org and fsf.org URLs 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
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<https://www.gnu.org/licenses/>. */
powerpc: POWER8 memcpy optimization for cached memory On POWER8, unaligned memory accesses to cached memory has little impact on performance as opposed to its ancestors. It is disabled by default and will only be available when the tunable glibc.tune.cached_memopt is set to 1. __memcpy_power8_cached __memcpy_power7 ============================================================ max-size=4096: 33325.70 ( 12.65%) 38153.00 max-size=8192: 32878.20 ( 11.17%) 37012.30 max-size=16384: 33782.20 ( 11.61%) 38219.20 max-size=32768: 33296.20 ( 11.30%) 37538.30 max-size=65536: 33765.60 ( 10.53%) 37738.40 * manual/tunables.texi (Hardware Capability Tunables): Document glibc.tune.cached_memopt. * sysdeps/powerpc/cpu-features.c: New file. * sysdeps/powerpc/cpu-features.h: New file. * sysdeps/powerpc/dl-procinfo.c [!IS_IN(ldconfig)]: Add _dl_powerpc_cpu_features. * sysdeps/powerpc/dl-tunables.list: New file. * sysdeps/powerpc/ldsodefs.h: Include cpu-features.h. * sysdeps/powerpc/powerpc32/power4/multiarch/init-arch.h (INIT_ARCH): Initialize use_aligned_memopt. * sysdeps/powerpc/powerpc64/dl-machine.h [defined(SHARED && IS_IN(rtld))]: Restrict dl_platform_init availability and initialize CPU features used by tunables. * sysdeps/powerpc/powerpc64/multiarch/Makefile (sysdep_routines): Add memcpy-power8-cached. * sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c: Add __memcpy_power8_cached. * sysdeps/powerpc/powerpc64/multiarch/memcpy.c: Likewise. * sysdeps/powerpc/powerpc64/multiarch/memcpy-power8-cached.S: New file. Reviewed-by: Rajalakshmi Srinivasaraghavan <raji@linux.vnet.ibm.com>
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#include <stdint.h>
#include <cpu-features.h>
#if HAVE_TUNABLES
# include <elf/dl-tunables.h>
#endif
static inline void
init_cpu_features (struct cpu_features *cpu_features)
{
/* Default is to use aligned memory access on optimized function unless
tunables is enable, since for this case user can explicit disable
unaligned optimizations. */
#if HAVE_TUNABLES
int32_t cached_memfunc = TUNABLE_GET (glibc, cpu, cached_memopt, int32_t,
powerpc: POWER8 memcpy optimization for cached memory On POWER8, unaligned memory accesses to cached memory has little impact on performance as opposed to its ancestors. It is disabled by default and will only be available when the tunable glibc.tune.cached_memopt is set to 1. __memcpy_power8_cached __memcpy_power7 ============================================================ max-size=4096: 33325.70 ( 12.65%) 38153.00 max-size=8192: 32878.20 ( 11.17%) 37012.30 max-size=16384: 33782.20 ( 11.61%) 38219.20 max-size=32768: 33296.20 ( 11.30%) 37538.30 max-size=65536: 33765.60 ( 10.53%) 37738.40 * manual/tunables.texi (Hardware Capability Tunables): Document glibc.tune.cached_memopt. * sysdeps/powerpc/cpu-features.c: New file. * sysdeps/powerpc/cpu-features.h: New file. * sysdeps/powerpc/dl-procinfo.c [!IS_IN(ldconfig)]: Add _dl_powerpc_cpu_features. * sysdeps/powerpc/dl-tunables.list: New file. * sysdeps/powerpc/ldsodefs.h: Include cpu-features.h. * sysdeps/powerpc/powerpc32/power4/multiarch/init-arch.h (INIT_ARCH): Initialize use_aligned_memopt. * sysdeps/powerpc/powerpc64/dl-machine.h [defined(SHARED && IS_IN(rtld))]: Restrict dl_platform_init availability and initialize CPU features used by tunables. * sysdeps/powerpc/powerpc64/multiarch/Makefile (sysdep_routines): Add memcpy-power8-cached. * sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c: Add __memcpy_power8_cached. * sysdeps/powerpc/powerpc64/multiarch/memcpy.c: Likewise. * sysdeps/powerpc/powerpc64/multiarch/memcpy-power8-cached.S: New file. Reviewed-by: Rajalakshmi Srinivasaraghavan <raji@linux.vnet.ibm.com>
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NULL);
cpu_features->use_cached_memopt = (cached_memfunc > 0);
#else
cpu_features->use_cached_memopt = false;
#endif
}