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f446d90fe6
The goal of this flag is to allow targets which don't prefer/have ERMS
to still access the non-temporal memset implementation.
There are 4 cases for tuning memset:
1) `Avoid_STOSB && Avoid_Non_Temporal_Memset`
- Memset with temporal stores
2) `Avoid_STOSB && !Avoid_Non_Temporal_Memset`
- Memset with temporal/non-temporal stores. Non-temporal path
goes through `rep stosb` path. We accomplish this by setting
`x86_rep_stosb_threshold` to
`x86_memset_non_temporal_threshold`.
3) `!Avoid_STOSB && Avoid_Non_Temporal_Memset`
- Memset with temporal stores/`rep stosb`
3) `!Avoid_STOSB && !Avoid_Non_Temporal_Memset`
- Memset with temporal stores/`rep stosb`/non-temporal stores.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
116 lines
3.7 KiB
C
116 lines
3.7 KiB
C
/* Common definition for memset/memset_chk ifunc selections.
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All versions must be listed in ifunc-impl-list.c.
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Copyright (C) 2017-2024 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 (erms) attribute_hidden;
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extern __typeof (REDIRECT_NAME) OPTIMIZE (avx512_unaligned)
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attribute_hidden;
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extern __typeof (REDIRECT_NAME) OPTIMIZE (avx512_unaligned_erms)
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attribute_hidden;
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extern __typeof (REDIRECT_NAME) OPTIMIZE (avx512_no_vzeroupper)
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attribute_hidden;
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extern __typeof (REDIRECT_NAME) OPTIMIZE (evex_unaligned)
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attribute_hidden;
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extern __typeof (REDIRECT_NAME) OPTIMIZE (evex_unaligned_erms)
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attribute_hidden;
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extern __typeof (REDIRECT_NAME) OPTIMIZE (avx2_unaligned) attribute_hidden;
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extern __typeof (REDIRECT_NAME) OPTIMIZE (avx2_unaligned_erms)
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attribute_hidden;
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extern __typeof (REDIRECT_NAME) OPTIMIZE (avx2_unaligned_rtm)
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attribute_hidden;
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extern __typeof (REDIRECT_NAME) OPTIMIZE (avx2_unaligned_erms_rtm)
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attribute_hidden;
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extern __typeof (REDIRECT_NAME) OPTIMIZE (sse2_unaligned)
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attribute_hidden;
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extern __typeof (REDIRECT_NAME) OPTIMIZE (sse2_unaligned_erms)
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attribute_hidden;
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static inline int
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prefer_erms_nt_impl (const struct cpu_features *cpu_features)
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{
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return CPU_FEATURE_USABLE_P (cpu_features, ERMS)
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|| !CPU_FEATURES_ARCH_P (cpu_features, Avoid_Non_Temporal_Memset);
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}
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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_FEATURES_ARCH_P (cpu_features, Prefer_ERMS))
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return OPTIMIZE (erms);
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if (X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, AVX512F)
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&& !CPU_FEATURES_ARCH_P (cpu_features, Prefer_No_AVX512))
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{
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if (X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, AVX512VL)
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&& X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, AVX512BW)
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&& X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, BMI2))
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{
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if (prefer_erms_nt_impl (cpu_features))
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return OPTIMIZE (avx512_unaligned_erms);
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return OPTIMIZE (avx512_unaligned);
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}
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return OPTIMIZE (avx512_no_vzeroupper);
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}
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if (X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, AVX2))
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{
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if (X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, AVX512VL)
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&& X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, AVX512BW)
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&& X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, BMI2))
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{
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if (prefer_erms_nt_impl (cpu_features))
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return OPTIMIZE (evex_unaligned_erms);
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return OPTIMIZE (evex_unaligned);
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}
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if (CPU_FEATURE_USABLE_P (cpu_features, RTM))
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{
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if (prefer_erms_nt_impl (cpu_features))
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return OPTIMIZE (avx2_unaligned_erms_rtm);
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return OPTIMIZE (avx2_unaligned_rtm);
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}
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if (X86_ISA_CPU_FEATURES_ARCH_P (cpu_features,
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Prefer_No_VZEROUPPER, !))
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{
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if (prefer_erms_nt_impl (cpu_features))
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return OPTIMIZE (avx2_unaligned_erms);
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return OPTIMIZE (avx2_unaligned);
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}
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}
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if (CPU_FEATURE_USABLE_P (cpu_features, ERMS)
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|| !CPU_FEATURES_ARCH_P (cpu_features, Avoid_Non_Temporal_Memset))
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return OPTIMIZE (sse2_unaligned_erms);
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return OPTIMIZE (sse2_unaligned);
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}
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