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/* memset/bzero -- set memory area to CH/0
Highly optimized version for ix86, x>=6.
Copyright (C) 1999-2021 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1999.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <sysdep.h>
#include "asm-syntax.h"
#define PARMS 4+4 /* space for 1 saved reg */
#ifdef USE_AS_BZERO
# define DEST PARMS
# define LEN DEST+4
#else
# define RTN PARMS
# define DEST RTN
# define CHR DEST+4
# define LEN CHR+4
#endif
.text
#if defined SHARED && IS_IN (libc) && !defined USE_AS_BZERO
ENTRY_CHK (__memset_chk)
movl 12(%esp), %eax
cmpl %eax, 16(%esp)
jb HIDDEN_JUMPTARGET (__chk_fail)
END_CHK (__memset_chk)
#endif
ENTRY (memset)
cld
pushl %edi
cfi_adjust_cfa_offset (4)
movl DEST(%esp), %edx
movl LEN(%esp), %ecx
#ifdef USE_AS_BZERO
xorl %eax, %eax /* fill with 0 */
#else
movzbl CHR(%esp), %eax
#endif
jecxz 1f
movl %edx, %edi
cfi_rel_offset (edi, 0)
andl $3, %edx
jz 2f /* aligned */
jp 3f /* misaligned at 3, store just one byte below */
stosb /* misaligned at 1 or 2, store two bytes */
decl %ecx
jz 1f
3: stosb
decl %ecx
jz 1f
xorl $1, %edx
jnz 2f /* was misaligned at 2 or 3, now aligned */
stosb /* was misaligned at 1, store third byte */
decl %ecx
2: movl %ecx, %edx
shrl $2, %ecx
andl $3, %edx
#ifndef USE_AS_BZERO
imul $0x01010101, %eax
#endif
rep
stosl
movl %edx, %ecx
rep
stosb
1:
#ifndef USE_AS_BZERO
movl DEST(%esp), %eax /* start address of destination is result */
#endif
popl %edi
cfi_adjust_cfa_offset (-4)
cfi_restore (edi)
ret
END (memset)
libc_hidden_builtin_def (memset)
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