1 | /* Copy memory block and return pointer to beginning of destination block |
2 | For Intel 80x86, x>=6. |
3 | This file is part of the GNU C Library. |
4 | Copyright (C) 1999-2024 Free Software Foundation, Inc. |
5 | |
6 | The GNU C Library is free software; you can redistribute it and/or |
7 | modify it under the terms of the GNU Lesser General Public |
8 | License as published by the Free Software Foundation; either |
9 | version 2.1 of the License, or (at your option) any later version. |
10 | |
11 | The GNU C Library is distributed in the hope that it will be useful, |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
14 | Lesser General Public License for more details. |
15 | |
16 | You should have received a copy of the GNU Lesser General Public |
17 | License along with the GNU C Library; if not, see |
18 | <https://www.gnu.org/licenses/>. */ |
19 | |
20 | #include <sysdep.h> |
21 | #include "asm-syntax.h" |
22 | |
23 | #define PARMS 4 /* no space for saved regs */ |
24 | #define RTN PARMS |
25 | #define DEST RTN |
26 | #define SRC DEST+4 |
27 | #define LEN SRC+4 |
28 | |
29 | .text |
30 | #if defined SHARED && IS_IN (libc) |
31 | ENTRY_CHK (__memcpy_chk) |
32 | movl 12(%esp), %eax |
33 | cmpl %eax, 16(%esp) |
34 | jb HIDDEN_JUMPTARGET (__chk_fail) |
35 | END_CHK (__memcpy_chk) |
36 | libc_hidden_builtin_def (__memcpy_chk) |
37 | #endif |
38 | ENTRY (memcpy) |
39 | |
40 | movl %edi, %eax |
41 | movl DEST(%esp), %edi |
42 | movl %esi, %edx |
43 | movl SRC(%esp), %esi |
44 | |
45 | movl %edi, %ecx |
46 | xorl %esi, %ecx |
47 | andl $3, %ecx |
48 | movl LEN(%esp), %ecx |
49 | cld |
50 | jne .Lunaligned |
51 | |
52 | cmpl $3, %ecx |
53 | jbe .Lunaligned |
54 | |
55 | testl $3, %esi |
56 | je 1f |
57 | movsb |
58 | decl %ecx |
59 | testl $3, %esi |
60 | je 1f |
61 | movsb |
62 | decl %ecx |
63 | testl $3, %esi |
64 | je 1f |
65 | movsb |
66 | decl %ecx |
67 | 1: pushl %eax |
68 | movl %ecx, %eax |
69 | shrl $2, %ecx |
70 | andl $3, %eax |
71 | rep |
72 | movsl |
73 | movl %eax, %ecx |
74 | rep |
75 | movsb |
76 | popl %eax |
77 | |
78 | .Lend: movl %eax, %edi |
79 | movl %edx, %esi |
80 | movl DEST(%esp), %eax |
81 | |
82 | ret |
83 | |
84 | /* When we come here the pointers do not have the same |
85 | alignment or the length is too short. No need to optimize for |
86 | aligned memory accesses. */ |
87 | .Lunaligned: |
88 | shrl $1, %ecx |
89 | jnc 1f |
90 | movsb |
91 | 1: shrl $1, %ecx |
92 | jnc 2f |
93 | movsw |
94 | 2: rep |
95 | movsl |
96 | jmp .Lend |
97 | END (memcpy) |
98 | libc_hidden_builtin_def (memcpy) |
99 | |