1/* $NetBSD: strncmp.S,v 1.2 2003/04/05 23:08:52 bjh21 Exp $ */ 2 3/* 4 * Copyright (c) 2002 ARM Ltd 5 * All rights reserved. 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 * 3. The name of the company may not be used to endorse or promote 16 * products derived from this software without specific prior written 17 * permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY ARM LTD ``AS IS'' AND ANY EXPRESS OR IMPLIED 20 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 21 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 22 * IN NO EVENT SHALL ARM LTD BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED 24 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 25 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 26 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 27 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 28 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31#include <machine/asm.h> 32 33__FBSDID("$FreeBSD$"); 34 35ENTRY(strncmp) 36/* if (len == 0) return 0 */ 37 cmp r2, #0 38 moveq r0, #0 39 moveq pc, lr 40 41/* ip == last src address to compare */ 42 adds ip, r0, r2 43/* Use last possible address on overflow. */ 44 movcs ip, #0 45 sub ip, ip, #1 461: 47 ldrb r2, [r0], #1 48 ldrb r3, [r1], #1 49 cmp ip, r0 50 cmpcs r2, #1 51 cmpcs r2, r3 52 beq 1b 53 sub r0, r2, r3 54 RET 55