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cc3fa755 | 1 | /* Highly optimized version for i586. |
04277e02 | 2 | Copyright (C) 1997-2019 Free Software Foundation, Inc. |
cc3fa755 UD |
3 | This file is part of the GNU C Library. |
4 | Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997. | |
5 | ||
6 | The GNU C Library is free software; you can redistribute it and/or | |
41bdb6e2 AJ |
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. | |
cc3fa755 UD |
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 | |
41bdb6e2 | 14 | Lesser General Public License for more details. |
cc3fa755 | 15 | |
41bdb6e2 | 16 | You should have received a copy of the GNU Lesser General Public |
59ba27a6 | 17 | License along with the GNU C Library; if not, see |
5a82c748 | 18 | <https://www.gnu.org/licenses/>. */ |
cc3fa755 UD |
19 | |
20 | #include <sysdep.h> | |
21 | #include "asm-syntax.h" | |
22 | ||
2366713d | 23 | #define PARMS 4+8 /* space for 2 saved regs */ |
7475d016 | 24 | #define RTN PARMS |
2366713d JM |
25 | #define DEST RTN |
26 | #define SRC DEST+4 | |
27 | #define LEN SRC+4 | |
cc3fa755 UD |
28 | |
29 | .text | |
4f41c682 | 30 | #if defined PIC && IS_IN (libc) |
9bdfff60 UD |
31 | ENTRY (__memcpy_chk) |
32 | movl 12(%esp), %eax | |
33 | cmpl %eax, 16(%esp) | |
34 | jb HIDDEN_JUMPTARGET (__chk_fail) | |
35 | END (__memcpy_chk) | |
36 | #endif | |
2366713d | 37 | ENTRY (memcpy) |
3f02f778 | 38 | |
cc3fa755 | 39 | pushl %edi |
1ad9da69 | 40 | cfi_adjust_cfa_offset (4) |
cc3fa755 | 41 | pushl %esi |
1ad9da69 | 42 | cfi_adjust_cfa_offset (4) |
cc3fa755 | 43 | |
3f02f778 | 44 | movl DEST(%esp), %edi |
1ad9da69 | 45 | cfi_rel_offset (edi, 4) |
3f02f778 | 46 | movl SRC(%esp), %esi |
fee732e5 | 47 | cfi_rel_offset (esi, 0) |
3f02f778 | 48 | movl LEN(%esp), %ecx |
cc3fa755 UD |
49 | movl %edi, %eax |
50 | ||
51 | /* We need this in any case. */ | |
52 | cld | |
53 | ||
54 | /* Cutoff for the big loop is a size of 32 bytes since otherwise | |
55 | the loop will never be entered. */ | |
56 | cmpl $32, %ecx | |
57 | jbe L(1) | |
58 | ||
59 | negl %eax | |
60 | andl $3, %eax | |
61 | subl %eax, %ecx | |
62 | xchgl %eax, %ecx | |
63 | ||
64 | rep; movsb | |
65 | ||
66 | movl %eax, %ecx | |
67 | subl $32, %ecx | |
68 | js L(2) | |
69 | ||
70 | /* Read ahead to make sure we write in the cache since the stupid | |
71 | i586 designers haven't implemented read-on-write-miss. */ | |
72 | movl (%edi), %eax | |
73 | L(3): movl 28(%edi), %edx | |
74 | ||
75 | /* Now correct the loop counter. Please note that in the following | |
76 | code the flags are not changed anymore. */ | |
77 | subl $32, %ecx | |
78 | ||
79 | movl (%esi), %eax | |
80 | movl 4(%esi), %edx | |
81 | movl %eax, (%edi) | |
82 | movl %edx, 4(%edi) | |
83 | movl 8(%esi), %eax | |
84 | movl 12(%esi), %edx | |
85 | movl %eax, 8(%edi) | |
86 | movl %edx, 12(%edi) | |
87 | movl 16(%esi), %eax | |
88 | movl 20(%esi), %edx | |
89 | movl %eax, 16(%edi) | |
90 | movl %edx, 20(%edi) | |
91 | movl 24(%esi), %eax | |
92 | movl 28(%esi), %edx | |
93 | movl %eax, 24(%edi) | |
94 | movl %edx, 28(%edi) | |
95 | ||
96 | leal 32(%esi), %esi | |
97 | leal 32(%edi), %edi | |
98 | ||
99 | jns L(3) | |
100 | ||
101 | /* Correct extra loop counter modification. */ | |
102 | L(2): addl $32, %ecx | |
b6e19c4b | 103 | #ifndef USE_AS_MEMPCPY |
3f02f778 | 104 | movl DEST(%esp), %eax |
cc3fa755 UD |
105 | #endif |
106 | ||
107 | L(1): rep; movsb | |
108 | ||
b6e19c4b | 109 | #ifdef USE_AS_MEMPCPY |
cc3fa755 UD |
110 | movl %edi, %eax |
111 | #endif | |
112 | ||
113 | popl %esi | |
1ad9da69 UD |
114 | cfi_adjust_cfa_offset (-4) |
115 | cfi_restore (esi) | |
cc3fa755 | 116 | popl %edi |
1ad9da69 UD |
117 | cfi_adjust_cfa_offset (-4) |
118 | cfi_restore (edi) | |
cc3fa755 | 119 | |
2366713d JM |
120 | ret |
121 | END (memcpy) | |
b6e19c4b | 122 | #ifndef USE_AS_MEMPCPY |
85dd1003 | 123 | libc_hidden_builtin_def (memcpy) |
44809672 | 124 | #endif |