1/* $NetBSD: strncmp.S,v 1.2 2013/08/19 00:57:25 matt 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 33RCSID("$NetBSD: strncmp.S,v 1.2 2013/08/19 00:57:25 matt Exp $") 34 35ENTRY(strncmp) 36/* if ((len - 1) < 0) return 0 */ 37 subs r2, r2, #1 38#ifdef __thumb__ 39 bmi 5f 40#else 41 movmi r0, #0 42 RETc(mi) 43#endif 44 45/* ip == last src address to compare */ 46#ifdef __thumb__ 47 adds r3, r0, r2 48 mov ip, r3 49 subs r1, r1, r0 50#else 51 add ip, r0, r2 52#endif 531: 54#ifdef __thumb__ 55 ldrb r2, [r0] 56 ldrb r3, [r1, r0] 57 adds r0, r0, #1 58 cmp ip, r0 /* exhausted length? */ 59 bcc 4f /* yes, we're done */ 60 cmp r2, #1 /* NUL? */ 61 bcc 4f /* yes, we're done */ 62 cmp r2, r3 /* different? */ 63#else 64 ldrb r2, [r0], #1 65 ldrb r3, [r1], #1 66 cmp ip, r0 67 cmpcs r2, #1 68 cmpcs r2, r3 69#endif 70 beq 1b 714: subs r0, r2, r3 72 RET 73#ifdef __thumb__ 745: movs r0, #0 75 RET 76#endif 77END(strncmp) 78