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__FBSDID("$FreeBSD$"); 29 30.syntax unified 31 32ENTRY(strlen) 33 mov r1, #0 34 /* Check that the pointer is aligned on 32 bits. */ 35 ands r3, r0, #3 36 beq .Loop 37 sub r0, r0, r3 38 ldr r2, [r0] 39 add r0, r0, #4 40 cmp r3, #2 41 blt .Ldo_3 42 bgt .Ldo_1 43 /* So that the N bit is set. */ 44 cmp r3, #0 45 b .Ldo_2 46 47.Loop: 48 ldr r2, [r0] 49 add r0, r0, #4 50 ands r3, r2, #0x000000ff 51 it ne 52 addne r1, r1, #1 53.Ldo_3: 54 itt ne 55 andsne r3, r2, #0x0000ff00 56 addne r1, r1, #1 57.Ldo_2: 58 itt ne 59 andsne r3, r2, #0x00ff0000 60 addne r1, r1, #1 61.Ldo_1: 62 ittt ne 63 andsne r3, r2, #0xff000000 64 addne r1, r1, #1 65 bne .Loop 66.Lexit: 67 mov r0, r1 68 RET 69END(strlen) 70 71 .section .note.GNU-stack,"",%progbits 72