2011-01-12 18:59:09 +00:00
|
|
|
/* Optimized strlen implementation for PowerPC476.
|
2014-01-01 11:03:15 +00:00
|
|
|
Copyright (C) 2010-2014 Free Software Foundation, Inc.
|
2011-01-12 18:59:09 +00:00
|
|
|
This file is part of the GNU C Library.
|
|
|
|
|
|
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
|
|
|
modify it under the terms of the GNU Lesser General Public
|
|
|
|
|
License as published by the Free Software Foundation; either
|
|
|
|
|
version 2.1 of the License, or (at your option) any later version.
|
|
|
|
|
|
|
|
|
|
The GNU C Library is distributed in the hope that it will be useful,
|
|
|
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
|
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
|
|
|
Lesser General Public License for more details.
|
|
|
|
|
|
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
2012-03-09 23:56:38 +00:00
|
|
|
License along with the GNU C Library. If not, see
|
|
|
|
|
<http://www.gnu.org/licenses/>. */
|
2011-01-12 18:59:09 +00:00
|
|
|
|
|
|
|
|
#include <sysdep.h>
|
|
|
|
|
|
|
|
|
|
/* strlen
|
|
|
|
|
|
|
|
|
|
Register Use
|
|
|
|
|
r3:source address and return length of string
|
|
|
|
|
r4:byte counter
|
|
|
|
|
|
|
|
|
|
Implementation description
|
|
|
|
|
Load 2 words at a time and count bytes, if we find null we subtract one from
|
|
|
|
|
the count and return the count value. We need to subtract one because
|
|
|
|
|
we don't count the null character as a byte. */
|
|
|
|
|
|
2013-02-28 21:23:47 +00:00
|
|
|
EALIGN (strlen,5,0)
|
2011-01-12 18:59:09 +00:00
|
|
|
neg r7,r3
|
|
|
|
|
clrlwi. r8,r7,29
|
|
|
|
|
addi r4,0,0
|
|
|
|
|
beq L(byte_count_loop)
|
|
|
|
|
mtctr r8
|
|
|
|
|
|
|
|
|
|
L(loop):
|
|
|
|
|
lbz r5,0(r3)
|
|
|
|
|
cmpi cr5,r5,0x0
|
|
|
|
|
addi r3,r3,0x1
|
|
|
|
|
addi r4,r4,0x1
|
|
|
|
|
beq cr5,L(end_strlen)
|
|
|
|
|
bdnz L(loop)
|
|
|
|
|
|
|
|
|
|
L(byte_count_loop):
|
|
|
|
|
lwz r5,0(r3)
|
|
|
|
|
lwz r6,4(r3)
|
|
|
|
|
dlmzb. r12,r5,r6
|
|
|
|
|
add r4,r4,r12
|
|
|
|
|
bne L(end_strlen)
|
|
|
|
|
lwz r5,8(r3)
|
|
|
|
|
lwz r6,12(r3)
|
|
|
|
|
dlmzb. r12,r5,r6
|
|
|
|
|
add r4,r4,r12
|
|
|
|
|
bne L(end_strlen)
|
|
|
|
|
lwz r5,16(r3)
|
|
|
|
|
lwz r6,20(r3)
|
|
|
|
|
dlmzb. r12,r5,r6
|
|
|
|
|
add r4,r4,r12
|
|
|
|
|
bne L(end_strlen)
|
|
|
|
|
lwz r5,24(r3)
|
|
|
|
|
lwz r6,28(r3)
|
|
|
|
|
addi r3,r3,0x20
|
|
|
|
|
dlmzb. r12,r5,r6
|
|
|
|
|
add r4,r4,r12
|
|
|
|
|
bne L(end_strlen)
|
|
|
|
|
b L(byte_count_loop)
|
|
|
|
|
|
|
|
|
|
L(end_strlen):
|
|
|
|
|
addi r3,r4,-1
|
|
|
|
|
blr
|
2013-02-28 21:23:47 +00:00
|
|
|
END (strlen)
|
2011-01-12 18:59:09 +00:00
|
|
|
libc_hidden_builtin_def (strlen)
|
