| 1 | /* Multiple versions of strcmp. |
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| 2 | All versions must be listed in ifunc-impl-list.c. |
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| 3 | Copyright (C) 2017-2024 Free Software Foundation, Inc. |
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| 4 | This file is part of the GNU C Library. |
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| 5 | |
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| 6 | The GNU C Library is free software; you can redistribute it and/or |
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| 7 | modify it under the terms of the GNU Lesser General Public |
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| 8 | License as published by the Free Software Foundation; either |
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| 9 | version 2.1 of the License, or (at your option) any later version. |
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| 10 | |
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| 11 | The GNU C Library is distributed in the hope that it will be useful, |
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| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 14 | Lesser General Public License for more details. |
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| 15 | |
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| 16 | You should have received a copy of the GNU Lesser General Public |
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| 17 | License along with the GNU C Library; if not, see |
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| 18 | <https://www.gnu.org/licenses/>. */ |
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| 19 | |
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| 20 | /* Define multiple versions only for the definition in libc. */ |
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| 21 | #if IS_IN (libc) |
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| 22 | # define strcmp __redirect_strcmp |
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| 23 | # include <string.h> |
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| 24 | # undef strcmp |
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| 25 | |
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| 26 | # define SYMBOL_NAME strcmp |
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| 27 | # include <init-arch.h> |
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| 28 | |
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| 29 | extern __typeof (REDIRECT_NAME) OPTIMIZE (evex) attribute_hidden; |
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| 30 | |
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| 31 | extern __typeof (REDIRECT_NAME) OPTIMIZE (avx2) attribute_hidden; |
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| 32 | extern __typeof (REDIRECT_NAME) OPTIMIZE (avx2_rtm) attribute_hidden; |
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| 33 | |
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| 34 | extern __typeof (REDIRECT_NAME) OPTIMIZE (sse42) attribute_hidden; |
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| 35 | |
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| 36 | extern __typeof (REDIRECT_NAME) |
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| 37 | OPTIMIZE (sse2_unaligned) attribute_hidden; |
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| 38 | extern __typeof (REDIRECT_NAME) OPTIMIZE (sse2) attribute_hidden; |
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| 39 | |
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| 40 | |
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| 41 | |
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| 42 | static inline void * |
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| 43 | IFUNC_SELECTOR (void) |
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| 44 | { |
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| 45 | const struct cpu_features *cpu_features = __get_cpu_features (); |
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| 46 | |
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| 47 | if (X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, AVX2) |
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| 48 | && X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, BMI2) |
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| 49 | && X86_ISA_CPU_FEATURES_ARCH_P (cpu_features, |
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| 50 | AVX_Fast_Unaligned_Load, )) |
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| 51 | { |
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| 52 | if (X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, AVX512VL) |
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| 53 | && X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, AVX512BW)) |
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| 54 | return OPTIMIZE (evex); |
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| 55 | |
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| 56 | if (CPU_FEATURE_USABLE_P (cpu_features, RTM)) |
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| 57 | return OPTIMIZE (avx2_rtm); |
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| 58 | |
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| 59 | if (X86_ISA_CPU_FEATURES_ARCH_P (cpu_features, |
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| 60 | Prefer_No_VZEROUPPER, !)) |
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| 61 | return OPTIMIZE (avx2); |
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| 62 | } |
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| 63 | |
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| 64 | if (X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, SSE4_2) |
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| 65 | /* Keep this as runtime check. Some ISA level >= 2 CPUs such as |
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| 66 | Tremont, Silvermont, and more check this. */ |
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| 67 | && !CPU_FEATURES_ARCH_P (cpu_features, Slow_SSE4_2)) |
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| 68 | return OPTIMIZE (sse42); |
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| 69 | |
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| 70 | /* Keep this as runtime check. The standard SSE2 version has |
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| 71 | meaningful optimizations around keeping all loads aligned in the |
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| 72 | main loop which can benefit some ISA level >= 2 CPUs. */ |
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| 73 | if (CPU_FEATURES_ARCH_P (cpu_features, Fast_Unaligned_Load)) |
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| 74 | return OPTIMIZE (sse2_unaligned); |
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| 75 | |
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| 76 | return OPTIMIZE (sse2); |
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| 77 | } |
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| 78 | |
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| 79 | libc_ifunc_redirected (__redirect_strcmp, strcmp, IFUNC_SELECTOR ()); |
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| 80 | |
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| 81 | # ifdef SHARED |
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| 82 | __hidden_ver1 (strcmp, __GI_strcmp, __redirect_strcmp) |
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| 83 | __attribute__ ((visibility ("hidden" ))) __attribute_copy__ (strcmp); |
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| 84 | # endif |
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| 85 | #endif |
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| 86 | |
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