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: strlcat_naive.S,v 1.1 2013/01/18 22:49:11 matt Exp $") 33 34/* LINTSTUB: size_t strlcat(char *, const char *, size_t) */ 35ENTRY(strlcat) 36 mov ip, r0 /* need to preserve r0 */ 37 add r3, r2, r0 /* point to just end of dst */ 381: cmp ip, r3 /* still within dst? */ 39 beq 4f /* no, get length of src */ 40 ldrb r2, [ip], #1 /* load next byte */ 41 teq r2, #0 /* was it a NUL? */ 42 bne 1b /* no, get next byte */ 43 44 sub r0, ip, r0 /* get actual length was dst */ 45 sub r0, r0, #1 /* account for the trailing NUL */ 46 sub r3, r3, #1 /* back up to last byte in dst */ 47 sub ip, ip, #1 /* back up over the NUL */ 48 492: ldrb r2, [r1], #1 /* load next byte from append */ 50 teq r2, #0 /* was it a NUL? */ 51 beq 3f /* yes, end of append */ 52 add r0, r0, #1 /* count another byte */ 53 cmp ip, r3 /* do we have enough room for it? */ 54 strltb r2, [ip], #1 /* yes, store it */ 55 b 2b /* get next byte from append */ 56 573: mov r2, #0 /* NUL */ 58 strb r2, [ip] /* append final NUL */ 59 RET /* return */ 60 614: sub r0, r3, r0 /* move size to return value */ 625: ldrb r2, [r1], #1 /* load next byte from append */ 63 teq r2, #0 /* was it a NUL? */ 64 RETc(eq) /* yes, we're done */ 65 add r0, r0, #1 /* add one to return value */ 66 b 5b /* get next byte from append */ 67END(strlcat) 68