1/*- 2 * Copyright (c) 2005 Olivier Houchard 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27#include <machine/asm.h> 28.syntax unified 29 30ENTRY(strlen) 31 mov r1, #0 32 /* Check that the pointer is aligned on 32 bits. */ 33 ands r3, r0, #3 34 beq .Loop 35 sub r0, r0, r3 36 ldr r2, [r0] 37 add r0, r0, #4 38 cmp r3, #2 39 blt .Ldo_3 40 bgt .Ldo_1 41 /* So that the N bit is set. */ 42 cmp r3, #0 43 b .Ldo_2 44 45.Loop: 46 ldr r2, [r0] 47 add r0, r0, #4 48 ands r3, r2, #0x000000ff 49 it ne 50 addne r1, r1, #1 51.Ldo_3: 52 itt ne 53 andsne r3, r2, #0x0000ff00 54 addne r1, r1, #1 55.Ldo_2: 56 itt ne 57 andsne r3, r2, #0x00ff0000 58 addne r1, r1, #1 59.Ldo_1: 60 ittt ne 61 andsne r3, r2, #0xff000000 62 addne r1, r1, #1 63 bne .Loop 64.Lexit: 65 mov r0, r1 66 RET 67END(strlen) 68 69 .section .note.GNU-stack,"",%progbits 70