xref: /freebsd/lib/libc/amd64/string/memset.S (revision 2284664ef9fcb0baaf59f1ef7df877c0b0f2b187)
1/*-
2 * Copyright (c) 2018 The FreeBSD Foundation
3 *
4 * This software was developed by Mateusz Guzik <mjg@FreeBSD.org>
5 * under sponsorship from the FreeBSD Foundation.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 * $FreeBSD$
29 */
30
31#include <machine/asm.h>
32__FBSDID("$FreeBSD$");
33
34.macro MEMSET bzero
35.if \bzero == 1
36	movq	%rsi,%rcx
37	movq	%rsi,%rdx
38	xorl	%eax,%eax
39.else
40	movq	%rdi,%r9
41	movq	%rdx,%rcx
42	movzbq	%sil,%r8
43	movabs	$0x0101010101010101,%rax
44	imulq	%r8,%rax
45.endif
46	cmpq	$15,%rcx
47	jbe	1f
48	shrq	$3,%rcx
49	rep
50	stosq
51	movq	%rdx,%rcx
52	andq	$7,%rcx
53	jne	1f
54.if \bzero == 0
55	movq	%r9,%rax
56.endif
57	ret
581:
59	rep
60	stosb
61.if \bzero == 0
62	movq	%r9,%rax
63.endif
64	ret
65.endm
66
67#ifndef BZERO
68ENTRY(memset)
69	MEMSET bzero=0
70END(memset)
71#else
72ENTRY(bzero)
73	MEMSET bzero=1
74END(bzero)
75#endif
76
77	.section .note.GNU-stack,"",%progbits
78