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3edda6a0f0
1. Refactor files so that all implementations for in the multiarch
directory.
- Essentially moved sse2 {raw|w}memchr.S implementation to
multiarch/{raw|w}memchr-sse2.S
- The non-multiarch {raw|w}memchr.S file now only includes one of
the implementations in the multiarch directory based on the
compiled ISA level (only used for non-multiarch builds.
Otherwise we go through the ifunc selector).
2. Add ISA level build guards to different implementations.
- I.e memchr-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 (memchr-evex{-rtm}.S).
3. Add new multiarch/rtld-{raw}memchr.S that just include the
non-multiarch {raw}memchr.S which will in turn select the best
implementation based on the compiled ISA level.
4. 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.
- Guranteed replacement essentially means that for any ISA level
build there must be a function that the baseline of the ISA
supports. So for {raw|w}memchr.S since there is not ISA level 2
function, the ISA level 2 build still includes the ISA level
1 (sse2) function. Once we reach the ISA level 3 build, however,
{raw|w}memchr-avx2{-rtm}.S will always be sufficient so the ISA
level 1 implementation ({raw|w}memchr-sse2.S) will not be built.
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.
60 lines
1.7 KiB
C
60 lines
1.7 KiB
C
/* Utility for including proper default function based on ISA level
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Copyright (C) 2022 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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#include <isa-level.h>
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#ifndef DEFAULT_IMPL_V1
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# error "Must have at least ISA V1 Version"
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#endif
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#ifndef DEFAULT_IMPL_V2
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# define DEFAULT_IMPL_V2 DEFAULT_IMPL_V1
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#endif
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#ifndef DEFAULT_IMPL_V3
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# define DEFAULT_IMPL_V3 DEFAULT_IMPL_V2
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#endif
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#ifndef DEFAULT_IMPL_V4
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# define DEFAULT_IMPL_V4 DEFAULT_IMPL_V3
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#endif
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#if MINIMUM_X86_ISA_LEVEL == 1
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# define ISA_DEFAULT_IMPL DEFAULT_IMPL_V1
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#elif MINIMUM_X86_ISA_LEVEL == 2
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# define ISA_DEFAULT_IMPL DEFAULT_IMPL_V2
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#elif MINIMUM_X86_ISA_LEVEL == 3
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# define ISA_DEFAULT_IMPL DEFAULT_IMPL_V3
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#elif MINIMUM_X86_ISA_LEVEL == 4
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# define ISA_DEFAULT_IMPL DEFAULT_IMPL_V4
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#else
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# error "Unsupported ISA Level!"
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#endif
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#if IS_IN(rtld)
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# if !defined USE_MULTIARCH
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# error "RTLD version should only exist in multiarch build"
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# endif
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#else
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# if defined USE_MULTIARCH
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# error "Multiarch build should not use ISA_DEFAULT_IMPL without RTLD"
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# endif
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#endif
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#include ISA_DEFAULT_IMPL
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