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glibc/sysdeps/x86_64/strncmp.S

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x86: Add support to build strcmp/strlen/strchr with explicit ISA level 1. Add default ISA level selection in non-multiarch/rtld implementations. 2. Add ISA level build guards to different implementations. - I.e strcmp-avx2.S which is ISA level 3 will only build if compiled ISA level <= 3. Otherwise there is no reason to include it as we will always use one of the ISA level 4 implementations (strcmp-evex.S). 3. Refactor the ifunc selector and ifunc implementation list to use the ISA level aware wrapper macros that allow functions below the compiled ISA level (with a guranteed replacement) to be skipped. Tested with and without multiarch on x86_64 for ISA levels: {generic, x86-64-v2, x86-64-v3, x86-64-v4} And m32 with and without multiarch.
2022-07-14 07:32:59 +08:00
/* strncmp dispatch for RTLD and non-multiarch build
Copyright (C) 1999-2022 Free Software Foundation, Inc.
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
<https://www.gnu.org/licenses/>. */
x86: Move strcmp SSE2 implementation to multiarch/strcmp-sse2.S This commit doesn't affect libc.so.6, its just housekeeping to prepare for adding explicit ISA level support. Because strcmp-sse2.S implements so many functions (more from avx2/evex/sse42) add a new file 'strcmp-naming.h' to assist in getting the correct symbol name for all the function across multiarch/non-multiarch builds. Tested build on x86_64 and x86_32 with/without multiarch.
2022-07-13 03:28:06 +08:00
/* Symbol = strncmp. */
x86: Add support to build strcmp/strlen/strchr with explicit ISA level 1. Add default ISA level selection in non-multiarch/rtld implementations. 2. Add ISA level build guards to different implementations. - I.e strcmp-avx2.S which is ISA level 3 will only build if compiled ISA level <= 3. Otherwise there is no reason to include it as we will always use one of the ISA level 4 implementations (strcmp-evex.S). 3. Refactor the ifunc selector and ifunc implementation list to use the ISA level aware wrapper macros that allow functions below the compiled ISA level (with a guranteed replacement) to be skipped. Tested with and without multiarch on x86_64 for ISA levels: {generic, x86-64-v2, x86-64-v3, x86-64-v4} And m32 with and without multiarch.
2022-07-14 07:32:59 +08:00
#define DEFAULT_IMPL_V1 "multiarch/strncmp-sse2.S"
/* This may cause regressions on some processors that heavily prefer
aligned loads or have slow a implementation of the `pcmpstri`
instruction. */
#define DEFAULT_IMPL_V2 "multiarch/strncmp-sse4_2.S"
#define DEFAULT_IMPL_V3 "multiarch/strncmp-avx2.S"
#define DEFAULT_IMPL_V4 "multiarch/strncmp-evex.S"
#include "isa-default-impl.h"
x86: Move strcmp SSE2 implementation to multiarch/strcmp-sse2.S This commit doesn't affect libc.so.6, its just housekeeping to prepare for adding explicit ISA level support. Because strcmp-sse2.S implements so many functions (more from avx2/evex/sse42) add a new file 'strcmp-naming.h' to assist in getting the correct symbol name for all the function across multiarch/non-multiarch builds. Tested build on x86_64 and x86_32 with/without multiarch.
2022-07-13 03:28:06 +08:00
libc_hidden_builtin_def (strncmp)
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