uclibc-ng/libc/string/avr32/strlen.S

/*
 * Copyright (C) 2004-2007 Atmel Corporation
 *
 * This file is subject to the terms and conditions of the GNU Lesser General
 * Public License.  See the file "COPYING.LIB" in the main directory of this
 * archive for more details.
 */

#include <features.h>

#define str r12

       .text
       .global strlen
       .type   strlen, @function
strlen:
       mov     r11, r12

       mov     r9, str
       andl    r9, 3, COH
       brne    .Lunaligned_str

1:     ld.w    r8, str++
       tnbz    r8
       brne    1b

       sub     r12, r11
       bfextu  r9, r8, 24, 8
       cp.w    r9, 0
       subeq   r12, 4
       reteq   r12
       bfextu  r9, r8, 16, 8
       cp.w    r9, 0
       subeq   r12, 3
       reteq   r12
       bfextu  r9, r8, 8, 8
       cp.w    r9, 0
       subeq   r12, 2
       reteq   r12
       sub     r12, 1
       retal   r12

.Lunaligned_str:
       add     pc, pc, r9 << 3
       sub     r0, r0, 0       /* 4-byte nop */
       ld.ub   r8, str++
       sub     r8, r8, 0
       breq    1f
       ld.ub   r8, str++
       sub     r8, r8, 0
       breq    1f
       ld.ub   r8, str++
       sub     r8, r8, 0
       brne    1b

1:     sub     r12, 1
       sub     r12, r11
       retal   r12

       .size   strlen, . - strlen

libc_hidden_def(strlen)