| 1 | /* memset with REP MOVSB/STOSB |
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| 2 | Copyright (C) 2015-2022 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 <sysdep.h> |
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| 20 | |
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| 21 | #define CFI_PUSH(REG) \ |
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| 22 | cfi_adjust_cfa_offset (4); \ |
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| 23 | cfi_rel_offset (REG, 0) |
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| 24 | |
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| 25 | #define CFI_POP(REG) \ |
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| 26 | cfi_adjust_cfa_offset (-4); \ |
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| 27 | cfi_restore (REG) |
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| 28 | |
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| 29 | #define PUSH(REG) pushl REG; CFI_PUSH (REG) |
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| 30 | #define POP(REG) popl REG; CFI_POP (REG) |
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| 31 | |
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| 32 | #define STR1 8 |
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| 33 | #ifdef USE_AS_BZERO |
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| 34 | #define N STR1+4 |
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| 35 | #else |
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| 36 | #define STR2 STR1+4 |
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| 37 | #define N STR2+4 |
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| 38 | #endif |
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| 39 | |
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| 40 | .text |
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| 41 | #if defined SHARED && IS_IN (libc) && !defined USE_AS_BZERO |
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| 42 | ENTRY (__memset_chk) |
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| 43 | movl 12(%esp), %eax |
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| 44 | cmpl %eax, 16(%esp) |
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| 45 | jb HIDDEN_JUMPTARGET (__chk_fail) |
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| 46 | END (__memset_chk) |
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| 47 | #endif |
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| 48 | ENTRY (memset) |
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| 49 | PUSH (%edi) |
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| 50 | movl N(%esp), %ecx |
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| 51 | movl STR1(%esp), %edi |
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| 52 | #ifdef USE_AS_BZERO |
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| 53 | xor %eax, %eax |
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| 54 | #else |
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| 55 | movzbl STR2(%esp), %eax |
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| 56 | mov %edi, %edx |
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| 57 | #endif |
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| 58 | rep stosb |
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| 59 | #ifndef USE_AS_BZERO |
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| 60 | mov %edx, %eax |
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| 61 | #endif |
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| 62 | POP (%edi) |
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| 63 | ret |
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| 64 | END (memset) |
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| 65 | |
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| 66 | #ifndef USE_AS_BZERO |
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| 67 | libc_hidden_builtin_def (memset) |
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| 68 | #endif |
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| 69 | |
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