strcat_naive.S revision 1.1.2.3
1 1.1.2.2 yamt /*- 2 1.1.2.2 yamt * Copyright (c) 2013 The NetBSD Foundation, Inc. 3 1.1.2.2 yamt * All rights reserved. 4 1.1.2.2 yamt * 5 1.1.2.2 yamt * This code is derived from software contributed to The NetBSD Foundation 6 1.1.2.2 yamt * by Matt Thomas of 3am Software Foundry. 7 1.1.2.2 yamt * 8 1.1.2.2 yamt * Redistribution and use in source and binary forms, with or without 9 1.1.2.2 yamt * modification, are permitted provided that the following conditions 10 1.1.2.2 yamt * are met: 11 1.1.2.2 yamt * 1. Redistributions of source code must retain the above copyright 12 1.1.2.2 yamt * notice, this list of conditions and the following disclaimer. 13 1.1.2.2 yamt * 2. Redistributions in binary form must reproduce the above copyright 14 1.1.2.2 yamt * notice, this list of conditions and the following disclaimer in the 15 1.1.2.2 yamt * documentation and/or other materials provided with the distribution. 16 1.1.2.2 yamt * 17 1.1.2.2 yamt * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 18 1.1.2.2 yamt * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 19 1.1.2.2 yamt * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 20 1.1.2.2 yamt * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 21 1.1.2.2 yamt * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 22 1.1.2.2 yamt * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 23 1.1.2.2 yamt * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 24 1.1.2.2 yamt * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 25 1.1.2.2 yamt * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 26 1.1.2.2 yamt * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 27 1.1.2.2 yamt * POSSIBILITY OF SUCH DAMAGE. 28 1.1.2.2 yamt */ 29 1.1.2.2 yamt 30 1.1.2.2 yamt #include <machine/asm.h> 31 1.1.2.2 yamt 32 1.1.2.3 yamt RCSID("$NetBSD: strcat_naive.S,v 1.1.2.3 2014/05/22 11:26:28 yamt Exp $") 33 1.1.2.2 yamt 34 1.1.2.2 yamt ENTRY(strcat) 35 1.1.2.2 yamt mov ip, r0 /* need to preserve r0 */ 36 1.1.2.3 yamt #if defined(__thumb__) 37 1.1.2.3 yamt 1: ldrb r2, [r0] /* load next byte */ 38 1.1.2.3 yamt adds r0, r0, #1 /* advance */ 39 1.1.2.3 yamt cmp r2, #0 /* was it a NUL? */ 40 1.1.2.3 yamt bne 1b /* no, get next byte */ 41 1.1.2.3 yamt subs r0, r0, #1 /* back up one to the NUL */ 42 1.1.2.3 yamt subs r1, r1, r0 /* save one increment */ 43 1.1.2.3 yamt 2: ldrb r2, [r1, r0] /* load next byte from append */ 44 1.1.2.3 yamt strb r2, [r0] /* store it */ 45 1.1.2.3 yamt adds r0, r0, #1 /* advance */ 46 1.1.2.3 yamt cmp r2, #0 /* was it a NUL? */ 47 1.1.2.3 yamt bne 2b /* no, get next byte */ 48 1.1.2.3 yamt mov r0, ip /* restore dst address */ 49 1.1.2.3 yamt RET /* return */ 50 1.1.2.3 yamt #else /* !__thumb__ */ 51 1.1.2.3 yamt mov ip, r0 /* need to preserve r0 */ 52 1.1.2.2 yamt 1: ldrb r2, [ip], #1 /* load next byte */ 53 1.1.2.2 yamt teq r2, #0 /* was it a NUL? */ 54 1.1.2.2 yamt bne 1b /* no, get next byte */ 55 1.1.2.2 yamt sub ip, ip, #1 /* back up one to the NUL */ 56 1.1.2.2 yamt 2: ldrb r2, [r1], #1 /* load next byte from append */ 57 1.1.2.2 yamt strb r2, [ip], #1 /* store it */ 58 1.1.2.2 yamt teq r2, #0 /* was it a NUL? */ 59 1.1.2.2 yamt bne 2b /* no, get next byte */ 60 1.1.2.2 yamt RET /* return */ 61 1.1.2.3 yamt #endif 62 1.1.2.2 yamt END(strcat) 63
Indexes created Tue Sep 30 20:09:53 GMT 2025