| 1 | /* IFUNC resolver with CPU_FEATURE_ACTIVE. |
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| 2 | Copyright (C) 2021-2024 Free Software Foundation, Inc. |
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| 3 | This file is part of the GNU C Library. |
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| 4 | |
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| 5 | The GNU C Library is free software; you can redistribute it and/or |
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| 6 | modify it under the terms of the GNU Lesser General Public |
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| 7 | License as published by the Free Software Foundation; either |
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| 8 | version 2.1 of the License, or (at your option) any later version. |
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| 9 | |
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| 10 | The GNU C Library is distributed in the hope that it will be useful, |
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| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 13 | Lesser General Public License for more details. |
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| 14 | |
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| 15 | You should have received a copy of the GNU Lesser General Public |
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| 16 | License along with the GNU C Library; if not, see |
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| 17 | <https://www.gnu.org/licenses/>. */ |
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| 18 | |
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| 19 | #include <sys/platform/x86.h> |
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| 20 | |
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| 21 | enum isa |
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| 22 | { |
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| 23 | none, |
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| 24 | sse2, |
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| 25 | sse4_2, |
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| 26 | avx, |
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| 27 | avx2, |
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| 28 | avx512f |
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| 29 | }; |
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| 30 | |
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| 31 | enum isa |
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| 32 | __attribute__ ((__optimize__ ("-fno-stack-protector" ))) |
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| 33 | get_isa (void) |
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| 34 | { |
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| 35 | if (CPU_FEATURE_ACTIVE (AVX512F)) |
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| 36 | return avx512f; |
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| 37 | if (CPU_FEATURE_ACTIVE (AVX2)) |
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| 38 | return avx2; |
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| 39 | if (CPU_FEATURE_ACTIVE (AVX)) |
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| 40 | return avx; |
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| 41 | if (CPU_FEATURE_ACTIVE (SSE4_2)) |
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| 42 | return sse4_2; |
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| 43 | if (CPU_FEATURE_ACTIVE (SSE2)) |
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| 44 | return sse2; |
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| 45 | return none; |
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| 46 | } |
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| 47 | |
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| 48 | static int |
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| 49 | isa_sse2 (void) |
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| 50 | { |
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| 51 | return sse2; |
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| 52 | } |
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| 53 | |
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| 54 | static int |
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| 55 | isa_sse4_2 (void) |
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| 56 | { |
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| 57 | return sse4_2; |
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| 58 | } |
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| 59 | |
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| 60 | static int |
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| 61 | isa_avx (void) |
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| 62 | { |
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| 63 | return avx; |
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| 64 | } |
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| 65 | |
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| 66 | static int |
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| 67 | isa_avx2 (void) |
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| 68 | { |
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| 69 | return avx2; |
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| 70 | } |
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| 71 | |
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| 72 | static int |
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| 73 | isa_avx512f (void) |
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| 74 | { |
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| 75 | return avx512f; |
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| 76 | } |
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| 77 | |
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| 78 | static int |
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| 79 | isa_none (void) |
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| 80 | { |
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| 81 | return none; |
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| 82 | } |
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| 83 | |
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| 84 | int foo (void) __attribute__ ((ifunc ("foo_ifunc" ))); |
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| 85 | |
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| 86 | void * |
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| 87 | __attribute__ ((__optimize__ ("-fno-stack-protector" ))) |
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| 88 | foo_ifunc (void) |
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| 89 | { |
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| 90 | switch (get_isa ()) |
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| 91 | { |
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| 92 | case avx512f: |
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| 93 | return isa_avx512f; |
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| 94 | case avx2: |
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| 95 | return isa_avx2; |
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| 96 | case avx: |
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| 97 | return isa_avx; |
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| 98 | case sse4_2: |
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| 99 | return isa_sse4_2; |
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| 100 | case sse2: |
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| 101 | return isa_sse2; |
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| 102 | default: |
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| 103 | break; |
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| 104 | } |
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| 105 | return isa_none; |
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| 106 | } |
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| 107 | |
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