1/* memset with REP MOVSB/STOSB
2   Copyright (C) 2015-2021 Free Software Foundation, Inc.
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
17   <https://www.gnu.org/licenses/>.  */
18
19#include <sysdep.h>
20
21#define CFI_PUSH(REG)						\
22  cfi_adjust_cfa_offset (4);					\
23  cfi_rel_offset (REG, 0)
24
25#define CFI_POP(REG)						\
26  cfi_adjust_cfa_offset (-4);					\
27  cfi_restore (REG)
28
29#define PUSH(REG)	pushl REG; CFI_PUSH (REG)
30#define POP(REG)	popl REG; CFI_POP (REG)
31
32#define STR1  8
33#ifdef USE_AS_BZERO
34#define N     STR1+4
35#else
36#define STR2  STR1+4
37#define N     STR2+4
38#endif
39
40	.text
41#if defined SHARED && IS_IN (libc) && !defined USE_AS_BZERO
42ENTRY (__memset_chk)
43	movl	12(%esp), %eax
44	cmpl	%eax, 16(%esp)
45	jb	HIDDEN_JUMPTARGET (__chk_fail)
46END (__memset_chk)
47#endif
48ENTRY (memset)
49	PUSH    (%edi)
50	movl	N(%esp), %ecx
51	movl	STR1(%esp), %edi
52#ifdef USE_AS_BZERO
53	xor	%eax, %eax
54#else
55	movzbl	STR2(%esp), %eax
56	mov	%edi, %edx
57#endif
58	rep	stosb
59#ifndef USE_AS_BZERO
60	mov	%edx, %eax
61#endif
62	POP     (%edi)
63	ret
64END (memset)
65
66#ifndef USE_AS_BZERO
67libc_hidden_builtin_def (memset)
68#endif
69