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 32RCSID("$NetBSD: strcat_naive.S,v 1.3 2013/08/19 17:02:25 matt Exp $") 33 34ENTRY(strcat) 35 mov ip, r0 /* need to preserve r0 */ 36#if defined(__thumb__) 371: ldrb r2, [r0] /* load next byte */ 38 adds r0, r0, #1 /* advance */ 39 cmp r2, #0 /* was it a NUL? */ 40 bne 1b /* no, get next byte */ 41 subs r0, r0, #1 /* back up one to the NUL */ 42 subs r1, r1, r0 /* save one increment */ 432: ldrb r2, [r1, r0] /* load next byte from append */ 44 strb r2, [r0] /* store it */ 45 adds r0, r0, #1 /* advance */ 46 cmp r2, #0 /* was it a NUL? */ 47 bne 2b /* no, get next byte */ 48 mov r0, ip /* restore dst address */ 49 RET /* return */ 50#else /* !__thumb__ */ 51 mov ip, r0 /* need to preserve r0 */ 521: ldrb r2, [ip], #1 /* load next byte */ 53 teq r2, #0 /* was it a NUL? */ 54 bne 1b /* no, get next byte */ 55 sub ip, ip, #1 /* back up one to the NUL */ 562: ldrb r2, [r1], #1 /* load next byte from append */ 57 strb r2, [ip], #1 /* store it */ 58 teq r2, #0 /* was it a NUL? */ 59 bne 2b /* no, get next byte */ 60 RET /* return */ 61#endif 62END(strcat) 63