xref: /netbsd-src/common/lib/libc/arch/arm/string/strcat_arm.S (revision 62f324d0121177eaf2e0384f92fd9ca2a751c795)
1/*-
2 * Copyright (c) 2013 The NetBSD Foundation, Inc.
3 * All rights reserved.
4 *
5 * This code is derived from software contributed to The NetBSD Foundation
6 * by Matt Thomas of 3am Software Foundry.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
18 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
19 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
20 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
21 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
22 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
25 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
27 * POSSIBILITY OF SUCH DAMAGE.
28 */
29
30#include <machine/asm.h>
31
32/*
33 * Implementation of strcat using strlen/strcpy.
34 */
35ENTRY(strcat)
36	str	lr, [sp, #-8]!		/* save return address */
37	push	{r4, r5}		/* save registers */
38
39	mov	r4, r0			/* save dst */
40	mov	r5, r1			/* save append */
41
42	bl	PLT_SYM(strlen)		/* find length of dst */
43
44	add	r0, r0, r4		/* add to dst pointer */
45	mov	r1, r5			/* fetch append */
46	bl	PLT_SYM(strcpy)		/* append string */
47
48	mov	r0, r4			/* restore dst as return value */
49	pop	{r4, r5}		/* restore registers */
50	ldr	lr, [sp], #8		/* restore return address */
51	RET
52END(strcat)
53