1 /* Highly optimized version for i586.
2 Copyright (C) 1997-2013 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4 Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
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.
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.
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 <http://www.gnu.org/licenses/>. */
21 #include "asm-syntax.h"
25 /* BEWARE: `#ifdef memcpy' means that memcpy is redefined as `mempcpy',
26 and the return value is the byte after the last one copied in
28 #define MEMPCPY_P (defined memcpy)
30 #define PARMS LINKAGE+8 /* space for 2 saved regs */
32 #define DEST RTN+RTN_SIZE
33 #define SRC DEST+PTR_SIZE
34 #define LEN SRC+PTR_SIZE
37 #if defined PIC && !defined NOT_IN_libc
41 jb HIDDEN_JUMPTARGET (__chk_fail)
44 ENTRY (BP_SYM (memcpy))
47 cfi_adjust_cfa_offset (4)
49 cfi_adjust_cfa_offset (4)
52 cfi_rel_offset (edi, 4)
54 cfi_rel_offset (esi, 0)
58 /* We need this in any case. */
61 /* Cutoff for the big loop is a size of 32 bytes since otherwise
62 the loop will never be entered. */
77 /* Read ahead to make sure we write in the cache since the stupid
78 i586 designers haven't implemented read-on-write-miss. */
80 L(3): movl 28(%edi), %edx
82 /* Now correct the loop counter. Please note that in the following
83 code the flags are not changed anymore. */
108 /* Correct extra loop counter modification. */
111 movl DEST(%esp), %eax
121 cfi_adjust_cfa_offset (-4)
124 cfi_adjust_cfa_offset (-4)
128 END (BP_SYM (memcpy))
130 libc_hidden_builtin_def (memcpy)