mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-26 20:51:11 +00:00
102 lines
2.2 KiB
ArmAsm
102 lines
2.2 KiB
ArmAsm
/* strlen(str) -- determine the length of the string STR.
|
|
Copyright (C) 2009, 2010 Free Software Foundation, Inc.
|
|
Contributed by Ulrich Drepper <drepper@redhat.com>.
|
|
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>
|
|
|
|
|
|
.text
|
|
ENTRY(strlen)
|
|
xor %rax, %rax
|
|
mov %edi, %ecx
|
|
and $0x3f, %ecx
|
|
pxor %xmm0, %xmm0
|
|
cmp $0x30, %ecx
|
|
ja L(next)
|
|
movdqu (%rdi), %xmm1
|
|
pcmpeqb %xmm1, %xmm0
|
|
pmovmskb %xmm0, %edx
|
|
test %edx, %edx
|
|
jnz L(exit_less16)
|
|
mov %rdi, %rax
|
|
and $-16, %rax
|
|
jmp L(align16_start)
|
|
L(next):
|
|
mov %rdi, %rax
|
|
and $-16, %rax
|
|
pcmpeqb (%rax), %xmm0
|
|
mov $-1, %esi
|
|
sub %rax, %rcx
|
|
shl %cl, %esi
|
|
pmovmskb %xmm0, %edx
|
|
and %esi, %edx
|
|
jnz L(exit)
|
|
L(align16_start):
|
|
pxor %xmm0, %xmm0
|
|
pxor %xmm1, %xmm1
|
|
pxor %xmm2, %xmm2
|
|
pxor %xmm3, %xmm3
|
|
.p2align 4
|
|
L(align16_loop):
|
|
pcmpeqb 16(%rax), %xmm0
|
|
pmovmskb %xmm0, %edx
|
|
test %edx, %edx
|
|
jnz L(exit16)
|
|
|
|
pcmpeqb 32(%rax), %xmm1
|
|
pmovmskb %xmm1, %edx
|
|
test %edx, %edx
|
|
jnz L(exit32)
|
|
|
|
pcmpeqb 48(%rax), %xmm2
|
|
pmovmskb %xmm2, %edx
|
|
test %edx, %edx
|
|
jnz L(exit48)
|
|
|
|
pcmpeqb 64(%rax), %xmm3
|
|
pmovmskb %xmm3, %edx
|
|
lea 64(%rax), %rax
|
|
test %edx, %edx
|
|
jz L(align16_loop)
|
|
L(exit):
|
|
sub %rdi, %rax
|
|
L(exit_less16):
|
|
bsf %rdx, %rdx
|
|
add %rdx, %rax
|
|
ret
|
|
.p2align 4
|
|
L(exit16):
|
|
sub %rdi, %rax
|
|
bsf %rdx, %rdx
|
|
lea 16(%rdx,%rax), %rax
|
|
ret
|
|
.p2align 4
|
|
L(exit32):
|
|
sub %rdi, %rax
|
|
bsf %rdx, %rdx
|
|
lea 32(%rdx,%rax), %rax
|
|
ret
|
|
.p2align 4
|
|
L(exit48):
|
|
sub %rdi, %rax
|
|
bsf %rdx, %rdx
|
|
lea 48(%rdx,%rax), %rax
|
|
ret
|
|
END(strlen)
|
|
libc_hidden_builtin_def (strlen)
|