| xf.li | bdd93d5 | 2023-05-12 07:10:14 -0700 | [diff] [blame] | 1 | /* memcpy with REP MOVSB/STOSB |
| 2 | Copyright (C) 2015-2016 Free Software Foundation, Inc. |
| 3 | This file is part of the GNU C Library. |
| 4 | |
| 5 | The GNU C Library is free software; you can redistribute it and/or |
| 6 | modify it under the terms of the GNU Lesser General Public |
| 7 | License as published by the Free Software Foundation; either |
| 8 | version 2.1 of the License, or (at your option) any later version. |
| 9 | |
| 10 | The GNU C Library is distributed in the hope that it will be useful, |
| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 13 | Lesser General Public License for more details. |
| 14 | |
| 15 | You should have received a copy of the GNU Lesser General Public |
| 16 | License along with the GNU C Library; if not, see |
| 17 | <http://www.gnu.org/licenses/>. */ |
| 18 | |
| 19 | #include <sysdep.h> |
| 20 | #include "asm-syntax.h" |
| 21 | |
| 22 | #ifndef MEMCPY |
| 23 | # define MEMCPY memcpy |
| 24 | # define MEMCPY_CHK __memcpy_chk |
| 25 | #endif |
| 26 | |
| 27 | #ifdef USE_AS_BCOPY |
| 28 | # define STR2 12 |
| 29 | # define STR1 STR2+4 |
| 30 | # define N STR1+4 |
| 31 | #else |
| 32 | # define STR1 12 |
| 33 | # define STR2 STR1+4 |
| 34 | # define N STR2+4 |
| 35 | #endif |
| 36 | |
| 37 | #define CFI_PUSH(REG) \ |
| 38 | cfi_adjust_cfa_offset (4); \ |
| 39 | cfi_rel_offset (REG, 0) |
| 40 | |
| 41 | #define CFI_POP(REG) \ |
| 42 | cfi_adjust_cfa_offset (-4); \ |
| 43 | cfi_restore (REG) |
| 44 | |
| 45 | #define PUSH(REG) pushl REG; CFI_PUSH (REG) |
| 46 | #define POP(REG) popl REG; CFI_POP (REG) |
| 47 | |
| 48 | .text |
| 49 | #if defined SHARED && IS_IN (libc) && !defined USE_AS_BCOPY |
| 50 | ENTRY (MEMCPY_CHK) |
| 51 | movl 12(%esp), %eax |
| 52 | cmpl %eax, 16(%esp) |
| 53 | jb HIDDEN_JUMPTARGET (__chk_fail) |
| 54 | END (MEMCPY_CHK) |
| 55 | #endif |
| 56 | ENTRY (MEMCPY) |
| 57 | PUSH (%esi) |
| 58 | PUSH (%edi) |
| 59 | movl N(%esp), %ecx |
| 60 | movl STR1(%esp), %edi |
| 61 | movl STR2(%esp), %esi |
| 62 | mov %edi, %eax |
| 63 | #ifdef USE_AS_MEMPCPY |
| 64 | add %ecx, %eax |
| 65 | #endif |
| 66 | |
| 67 | #ifdef USE_AS_MEMMOVE |
| 68 | cmp %esi, %edi |
| 69 | ja L(copy_backward) |
| 70 | je L(bwd_write_0bytes) |
| 71 | #endif |
| 72 | |
| 73 | rep movsb |
| 74 | POP (%edi) |
| 75 | POP (%esi) |
| 76 | ret |
| 77 | |
| 78 | #ifdef USE_AS_MEMMOVE |
| 79 | L(copy_backward): |
| 80 | lea -1(%edi,%ecx), %edi |
| 81 | lea -1(%esi,%ecx), %esi |
| 82 | std |
| 83 | rep movsb |
| 84 | cld |
| 85 | L(bwd_write_0bytes): |
| 86 | POP (%edi) |
| 87 | POP (%esi) |
| 88 | ret |
| 89 | #endif |
| 90 | |
| 91 | END (MEMCPY) |
| 92 | |
| 93 | #ifndef USE_AS_BCOPY |
| 94 | libc_hidden_builtin_def (MEMCPY) |
| 95 | #endif |