/*-
 * Copyright (c) 2005 Olivier Houchard
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <machine/asm.h>
.syntax unified

ENTRY(strlen)
        mov     r1, #0
        /* Check that the pointer is aligned on 32 bits. */
        ands    r3, r0, #3
        beq     .Loop
        sub     r0, r0, r3
        ldr     r2, [r0]
        add     r0, r0, #4
        cmp     r3, #2
        blt     .Ldo_3
        bgt     .Ldo_1
        /* So that the N bit is set. */
        cmp     r3, #0
        b       .Ldo_2

.Loop:
        ldr     r2, [r0]
        add     r0, r0, #4
        ands    r3, r2, #0x000000ff
        it      ne
        addne   r1, r1, #1
.Ldo_3:
        itt     ne
        andsne    r3, r2, #0x0000ff00
        addne     r1, r1, #1
.Ldo_2:
        itt     ne
        andsne    r3, r2, #0x00ff0000
        addne   r1, r1, #1
.Ldo_1:
        ittt    ne
        andsne  r3, r2, #0xff000000
        addne   r1, r1, #1
        bne     .Loop                           
.Lexit:
        mov     r0, r1
        RET
END(strlen)

        .section .note.GNU-stack,"",%progbits