mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-30 00:31:08 +00:00
688903eb3e
* All files with FSF copyright notices: Update copyright dates using scripts/update-copyrights. * locale/programs/charmap-kw.h: Regenerated. * locale/programs/locfile-kw.h: Likewise.
259 lines
4.9 KiB
ArmAsm
259 lines
4.9 KiB
ArmAsm
/* SSE2 version of strlen/wcslen.
|
|
Copyright (C) 2012-2018 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>
|
|
|
|
#ifdef AS_WCSLEN
|
|
# define PMINU pminud
|
|
# define PCMPEQ pcmpeqd
|
|
# define SHIFT_RETURN shrq $2, %rax
|
|
#else
|
|
# define PMINU pminub
|
|
# define PCMPEQ pcmpeqb
|
|
# define SHIFT_RETURN
|
|
#endif
|
|
|
|
/* Long lived register in strlen(s), strnlen(s, n) are:
|
|
|
|
%xmm3 - zero
|
|
%rdi - s
|
|
%r10 (s+n) & (~(64-1))
|
|
%r11 s+n
|
|
*/
|
|
|
|
|
|
.text
|
|
ENTRY(strlen)
|
|
|
|
/* Test 64 bytes from %rax for zero. Save result as bitmask in %rdx. */
|
|
#define FIND_ZERO \
|
|
PCMPEQ (%rax), %xmm0; \
|
|
PCMPEQ 16(%rax), %xmm1; \
|
|
PCMPEQ 32(%rax), %xmm2; \
|
|
PCMPEQ 48(%rax), %xmm3; \
|
|
pmovmskb %xmm0, %esi; \
|
|
pmovmskb %xmm1, %edx; \
|
|
pmovmskb %xmm2, %r8d; \
|
|
pmovmskb %xmm3, %ecx; \
|
|
salq $16, %rdx; \
|
|
salq $16, %rcx; \
|
|
orq %rsi, %rdx; \
|
|
orq %r8, %rcx; \
|
|
salq $32, %rcx; \
|
|
orq %rcx, %rdx;
|
|
|
|
#ifdef AS_STRNLEN
|
|
/* Do not read anything when n==0. */
|
|
test %rsi, %rsi
|
|
jne L(n_nonzero)
|
|
xor %rax, %rax
|
|
ret
|
|
L(n_nonzero):
|
|
# ifdef AS_WCSLEN
|
|
shlq $2, %rsi
|
|
# endif
|
|
|
|
/* Initialize long lived registers. */
|
|
|
|
add %rdi, %rsi
|
|
mov %rsi, %r10
|
|
and $-64, %r10
|
|
mov %rsi, %r11
|
|
#endif
|
|
|
|
pxor %xmm0, %xmm0
|
|
pxor %xmm1, %xmm1
|
|
pxor %xmm2, %xmm2
|
|
pxor %xmm3, %xmm3
|
|
movq %rdi, %rax
|
|
movq %rdi, %rcx
|
|
andq $4095, %rcx
|
|
/* Offsets 4032-4047 will be aligned into 4032 thus fit into page. */
|
|
cmpq $4047, %rcx
|
|
/* We cannot unify this branching as it would be ~6 cycles slower. */
|
|
ja L(cross_page)
|
|
|
|
#ifdef AS_STRNLEN
|
|
/* Test if end is among first 64 bytes. */
|
|
# define STRNLEN_PROLOG \
|
|
mov %r11, %rsi; \
|
|
subq %rax, %rsi; \
|
|
andq $-64, %rax; \
|
|
testq $-64, %rsi; \
|
|
je L(strnlen_ret)
|
|
#else
|
|
# define STRNLEN_PROLOG andq $-64, %rax;
|
|
#endif
|
|
|
|
/* Ignore bits in mask that come before start of string. */
|
|
#define PROLOG(lab) \
|
|
movq %rdi, %rcx; \
|
|
xorq %rax, %rcx; \
|
|
STRNLEN_PROLOG; \
|
|
sarq %cl, %rdx; \
|
|
test %rdx, %rdx; \
|
|
je L(lab); \
|
|
bsfq %rdx, %rax; \
|
|
SHIFT_RETURN; \
|
|
ret
|
|
|
|
#ifdef AS_STRNLEN
|
|
andq $-16, %rax
|
|
FIND_ZERO
|
|
#else
|
|
/* Test first 16 bytes unaligned. */
|
|
movdqu (%rax), %xmm4
|
|
PCMPEQ %xmm0, %xmm4
|
|
pmovmskb %xmm4, %edx
|
|
test %edx, %edx
|
|
je L(next48_bytes)
|
|
bsf %edx, %eax /* If eax is zeroed 16bit bsf can be used. */
|
|
SHIFT_RETURN
|
|
ret
|
|
|
|
L(next48_bytes):
|
|
/* Same as FIND_ZERO except we do not check first 16 bytes. */
|
|
andq $-16, %rax
|
|
PCMPEQ 16(%rax), %xmm1
|
|
PCMPEQ 32(%rax), %xmm2
|
|
PCMPEQ 48(%rax), %xmm3
|
|
pmovmskb %xmm1, %edx
|
|
pmovmskb %xmm2, %r8d
|
|
pmovmskb %xmm3, %ecx
|
|
salq $16, %rdx
|
|
salq $16, %rcx
|
|
orq %r8, %rcx
|
|
salq $32, %rcx
|
|
orq %rcx, %rdx
|
|
#endif
|
|
|
|
/* When no zero byte is found xmm1-3 are zero so we do not have to
|
|
zero them. */
|
|
PROLOG(loop)
|
|
|
|
.p2align 4
|
|
L(cross_page):
|
|
andq $-64, %rax
|
|
FIND_ZERO
|
|
PROLOG(loop_init)
|
|
|
|
#ifdef AS_STRNLEN
|
|
/* We must do this check to correctly handle strnlen (s, -1). */
|
|
L(strnlen_ret):
|
|
bts %rsi, %rdx
|
|
sarq %cl, %rdx
|
|
test %rdx, %rdx
|
|
je L(loop_init)
|
|
bsfq %rdx, %rax
|
|
SHIFT_RETURN
|
|
ret
|
|
#endif
|
|
.p2align 4
|
|
L(loop_init):
|
|
pxor %xmm1, %xmm1
|
|
pxor %xmm2, %xmm2
|
|
pxor %xmm3, %xmm3
|
|
#ifdef AS_STRNLEN
|
|
.p2align 4
|
|
L(loop):
|
|
|
|
addq $64, %rax
|
|
cmpq %rax, %r10
|
|
je L(exit_end)
|
|
|
|
movdqa (%rax), %xmm0
|
|
PMINU 16(%rax), %xmm0
|
|
PMINU 32(%rax), %xmm0
|
|
PMINU 48(%rax), %xmm0
|
|
PCMPEQ %xmm3, %xmm0
|
|
pmovmskb %xmm0, %edx
|
|
testl %edx, %edx
|
|
jne L(exit)
|
|
jmp L(loop)
|
|
|
|
.p2align 4
|
|
L(exit_end):
|
|
cmp %rax, %r11
|
|
je L(first) /* Do not read when end is at page boundary. */
|
|
pxor %xmm0, %xmm0
|
|
FIND_ZERO
|
|
|
|
L(first):
|
|
bts %r11, %rdx
|
|
bsfq %rdx, %rdx
|
|
addq %rdx, %rax
|
|
subq %rdi, %rax
|
|
SHIFT_RETURN
|
|
ret
|
|
|
|
.p2align 4
|
|
L(exit):
|
|
pxor %xmm0, %xmm0
|
|
FIND_ZERO
|
|
|
|
bsfq %rdx, %rdx
|
|
addq %rdx, %rax
|
|
subq %rdi, %rax
|
|
SHIFT_RETURN
|
|
ret
|
|
|
|
#else
|
|
|
|
/* Main loop. Unrolled twice to improve L2 cache performance on core2. */
|
|
.p2align 4
|
|
L(loop):
|
|
|
|
movdqa 64(%rax), %xmm0
|
|
PMINU 80(%rax), %xmm0
|
|
PMINU 96(%rax), %xmm0
|
|
PMINU 112(%rax), %xmm0
|
|
PCMPEQ %xmm3, %xmm0
|
|
pmovmskb %xmm0, %edx
|
|
testl %edx, %edx
|
|
jne L(exit64)
|
|
|
|
subq $-128, %rax
|
|
|
|
movdqa (%rax), %xmm0
|
|
PMINU 16(%rax), %xmm0
|
|
PMINU 32(%rax), %xmm0
|
|
PMINU 48(%rax), %xmm0
|
|
PCMPEQ %xmm3, %xmm0
|
|
pmovmskb %xmm0, %edx
|
|
testl %edx, %edx
|
|
jne L(exit0)
|
|
jmp L(loop)
|
|
|
|
.p2align 4
|
|
L(exit64):
|
|
addq $64, %rax
|
|
L(exit0):
|
|
pxor %xmm0, %xmm0
|
|
FIND_ZERO
|
|
|
|
bsfq %rdx, %rdx
|
|
addq %rdx, %rax
|
|
subq %rdi, %rax
|
|
SHIFT_RETURN
|
|
ret
|
|
|
|
#endif
|
|
|
|
END(strlen)
|
|
libc_hidden_builtin_def (strlen)
|