1/* Copyright (c) 2010-2011, Linaro Limited 2 All rights reserved. 3 4 Redistribution and use in source and binary forms, with or without 5 modification, are permitted provided that the following conditions 6 are met: 7 8 * Redistributions of source code must retain the above copyright 9 notice, this list of conditions and the following disclaimer. 10 11 * Redistributions in binary form must reproduce the above copyright 12 notice, this list of conditions and the following disclaimer in the 13 documentation and/or other materials provided with the distribution. 14 15 * Neither the name of Linaro Limited nor the names of its 16 contributors may be used to endorse or promote products derived 17 from this software without specific prior written permission. 18 19 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 20 "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 21 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 22 A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 23 HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 24 SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 25 LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 26 DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 27 THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 28 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 29 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32/* 33 Written by Dave Gilbert <david.gilbert@linaro.org> 34 35 A very simple strchr routine, from benchmarks on A9 it's a bit faster than 36 the current version in eglibc (2.12.1-0ubuntu14 package) 37 I don't think doing a word at a time version is worth it since a lot 38 of strchr cases are very short anyway. 39 40 */ 41 42@ 2011-02-07 david.gilbert@linaro.org 43@ Extracted from local git a5b438d861 44 45 .syntax unified 46 .arch armv7-a 47 48 .text 49 .thumb 50 51@ --------------------------------------------------------------------------- 52 53 .thumb_func 54 .align 2 55 .p2align 4,,15 56 .global strchr 57 .type strchr,%function 58strchr: 59 @ r0 = start of string 60 @ r1 = character to match 61 @ returns NULL for no match, or a pointer to the match 62 and r1,r1, #255 63 641: 65 ldrb r2,[r0],#1 66 cmp r2,r1 67 cbz r2,10f 68 bne 1b 69 70 @ We're here if it matched 715: 72 subs r0,r0,#1 73 bx lr 74 7510: 76 @ We're here if we ran off the end 77 cmp r1, #0 @ Corner case - you're allowed to search for the nil and get a pointer to it 78 beq 5b @ A bit messy, if it's common we should branch at the start to a special loop 79 mov r0,#0 80 bx lr 81