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80883f4354
The rational is:
1. SSE42 has nearly identical logic so any benefit is minimal (3.4%
regression on Tigerlake using SSE42 versus AVX across the
benchtest suite).
2. AVX2 version covers the majority of targets that previously
prefered it.
3. The targets where AVX would still be best (SnB and IVB) are
becoming outdated.
All in all the saving the code size is worth it.
All string/memory tests pass.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
(cherry picked from commit 305769b2a1)
57 lines
2.1 KiB
C
57 lines
2.1 KiB
C
/* Common definition for strcasecmp famly ifunc selections.
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All versions must be listed in ifunc-impl-list.c.
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Copyright (C) 2017-2021 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 <init-arch.h>
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extern __typeof (REDIRECT_NAME) OPTIMIZE (sse2) attribute_hidden;
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extern __typeof (REDIRECT_NAME) OPTIMIZE (ssse3) attribute_hidden;
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extern __typeof (REDIRECT_NAME) OPTIMIZE (sse42) attribute_hidden;
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extern __typeof (REDIRECT_NAME) OPTIMIZE (avx2) attribute_hidden;
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extern __typeof (REDIRECT_NAME) OPTIMIZE (avx2_rtm) attribute_hidden;
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extern __typeof (REDIRECT_NAME) OPTIMIZE (evex) attribute_hidden;
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static inline void *
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IFUNC_SELECTOR (void)
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{
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const struct cpu_features* cpu_features = __get_cpu_features ();
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if (CPU_FEATURE_USABLE_P (cpu_features, AVX2)
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&& CPU_FEATURES_ARCH_P (cpu_features, AVX_Fast_Unaligned_Load))
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{
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if (CPU_FEATURE_USABLE_P (cpu_features, AVX512VL)
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&& CPU_FEATURE_USABLE_P (cpu_features, AVX512BW))
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return OPTIMIZE (evex);
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if (CPU_FEATURE_USABLE_P (cpu_features, RTM))
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return OPTIMIZE (avx2_rtm);
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if (!CPU_FEATURES_ARCH_P (cpu_features, Prefer_No_VZEROUPPER))
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return OPTIMIZE (avx2);
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}
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if (CPU_FEATURE_USABLE_P (cpu_features, SSE4_2)
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&& !CPU_FEATURES_ARCH_P (cpu_features, Slow_SSE4_2))
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return OPTIMIZE (sse42);
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if (CPU_FEATURE_USABLE_P (cpu_features, SSSE3))
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return OPTIMIZE (ssse3);
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return OPTIMIZE (sse2);
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}
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