1/* memset implement with rep stosb
2   Copyright (C) 2022 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
20#include <sysdep.h>
21
22#if defined USE_MULTIARCH && IS_IN (libc)
23	.text
24ENTRY (__memset_chk_erms)
25	cmp	%RDX_LP, %RCX_LP
26	jb	HIDDEN_JUMPTARGET (__chk_fail)
27END (__memset_chk_erms)
28
29/* Only used to measure performance of REP STOSB.  */
30ENTRY (__memset_erms)
31	/* Skip zero length.  */
32	test	%RDX_LP, %RDX_LP
33	jz	 L(stosb_return_zero)
34	mov	%RDX_LP, %RCX_LP
35	movzbl	%sil, %eax
36	mov	%RDI_LP, %RDX_LP
37	rep stosb
38	mov	%RDX_LP, %RAX_LP
39	ret
40L(stosb_return_zero):
41	movq	%rdi, %rax
42	ret
43END (__memset_erms)
44#endif
45