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d226114b | 1 | /* memcpy with REP MOVSB/STOSB |
d614a753 | 2 | Copyright (C) 2015-2020 Free Software Foundation, Inc. |
d226114b L |
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 | |
5a82c748 | 17 | <https://www.gnu.org/licenses/>. */ |
d226114b L |
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 |