Current File : //proc/self/root/glibc-2.29/sysdeps/csky/abiv2/strlen.S
/* The assembly function for string length. C-SKY ABIV2 version.
Copyright (C) 2018-2019 Free Software Foundation, Inc.
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
License along with the GNU C Library. If not, see
<http://www.gnu.org/licenses/>. */
#include <sysdep.h>
ENTRY (strlen)
/* Check if the start addr is aligned. */
mov r3, r0
andi r1, r0, 3
movi r2, 4
movi r0, 0
bnez r1, .L_start_not_aligned
LABLE_ALIGN
.L_start_addr_aligned:
/* Check if all the bytes in the word are not zero. */
ldw r1, (r3)
tstnbz r1
bf .L_string_tail
ldw r1, (r3, 4)
addi r0, 4
tstnbz r1
bf .L_string_tail
ldw r1, (r3, 8)
addi r0, 4
tstnbz r1
bf .L_string_tail
ldw r1, (r3, 12)
addi r0, 4
tstnbz r1
bf .L_string_tail
ldw r1, (r3, 16)
addi r0, 4
tstnbz r1
bf .L_string_tail
ldw r1, (r3, 20)
addi r0, 4
tstnbz r1
bf .L_string_tail
ldw r1, (r3, 24)
addi r0, 4
tstnbz r1
bf .L_string_tail
ldw r1, (r3, 28)
addi r0, 4
tstnbz r1
bf .L_string_tail
addi r0, 4
addi r3, 32
br .L_start_addr_aligned
.L_string_tail:
xtrb3 r3, r1
bez r3, .L_return
addi r0, 1
xtrb2 r3, r1
bez r3, .L_return
addi r0, 1
xtrb1 r3, r1
bez r3, .L_return
addi r0, 1
.L_return:
rts
.L_start_not_aligned:
sub r2, r2, r1
.L_start_not_aligned_loop:
ldb r1, (r3)
PRE_BNEZAD (r2)
addi r3, 1
bez r1, .L_return
addi r0, 1
BNEZAD (r2, .L_start_not_aligned_loop)
br .L_start_addr_aligned
END (strlen)
libc_hidden_def (strlen)
.weak strlen
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