mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-25 06:20:06 +00:00
581c785bf3
I used these shell commands: ../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright (cd ../glibc && git commit -am"[this commit message]") and then ignored the output, which consisted lines saying "FOO: warning: copyright statement not found" for each of 7061 files FOO. I then removed trailing white space from math/tgmath.h, support/tst-support-open-dev-null-range.c, and sysdeps/x86_64/multiarch/strlen-vec.S, to work around the following obscure pre-commit check failure diagnostics from Savannah. I don't know why I run into these diagnostics whereas others evidently do not. remote: *** 912-#endif remote: *** 913: remote: *** 914- remote: *** error: lines with trailing whitespace found ... remote: *** error: sysdeps/unix/sysv/linux/statx_cp.c: trailing lines
558 lines
13 KiB
ArmAsm
558 lines
13 KiB
ArmAsm
/* strlen/strnlen/wcslen/wcsnlen optimized with AVX2.
|
|
Copyright (C) 2017-2022 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
|
|
<https://www.gnu.org/licenses/>. */
|
|
|
|
#if IS_IN (libc)
|
|
|
|
# include <sysdep.h>
|
|
|
|
# ifndef STRLEN
|
|
# define STRLEN __strlen_avx2
|
|
# endif
|
|
|
|
# ifdef USE_AS_WCSLEN
|
|
# define VPCMPEQ vpcmpeqd
|
|
# define VPMINU vpminud
|
|
# define CHAR_SIZE 4
|
|
# else
|
|
# define VPCMPEQ vpcmpeqb
|
|
# define VPMINU vpminub
|
|
# define CHAR_SIZE 1
|
|
# endif
|
|
|
|
# ifndef VZEROUPPER
|
|
# define VZEROUPPER vzeroupper
|
|
# endif
|
|
|
|
# ifndef SECTION
|
|
# define SECTION(p) p##.avx
|
|
# endif
|
|
|
|
# define VEC_SIZE 32
|
|
# define PAGE_SIZE 4096
|
|
# define CHAR_PER_VEC (VEC_SIZE / CHAR_SIZE)
|
|
|
|
.section SECTION(.text),"ax",@progbits
|
|
ENTRY (STRLEN)
|
|
# ifdef USE_AS_STRNLEN
|
|
/* Check zero length. */
|
|
# ifdef __ILP32__
|
|
/* Clear upper bits. */
|
|
and %RSI_LP, %RSI_LP
|
|
# else
|
|
test %RSI_LP, %RSI_LP
|
|
# endif
|
|
jz L(zero)
|
|
/* Store max len in R8_LP before adjusting if using WCSLEN. */
|
|
mov %RSI_LP, %R8_LP
|
|
# endif
|
|
movl %edi, %eax
|
|
movq %rdi, %rdx
|
|
vpxor %xmm0, %xmm0, %xmm0
|
|
/* Clear high bits from edi. Only keeping bits relevant to page
|
|
cross check. */
|
|
andl $(PAGE_SIZE - 1), %eax
|
|
/* Check if we may cross page boundary with one vector load. */
|
|
cmpl $(PAGE_SIZE - VEC_SIZE), %eax
|
|
ja L(cross_page_boundary)
|
|
|
|
/* Check the first VEC_SIZE bytes. */
|
|
VPCMPEQ (%rdi), %ymm0, %ymm1
|
|
vpmovmskb %ymm1, %eax
|
|
# ifdef USE_AS_STRNLEN
|
|
/* If length < VEC_SIZE handle special. */
|
|
cmpq $CHAR_PER_VEC, %rsi
|
|
jbe L(first_vec_x0)
|
|
# endif
|
|
/* If empty continue to aligned_more. Otherwise return bit
|
|
position of first match. */
|
|
testl %eax, %eax
|
|
jz L(aligned_more)
|
|
tzcntl %eax, %eax
|
|
# ifdef USE_AS_WCSLEN
|
|
/* NB: Divide bytes by 4 to get wchar_t count. */
|
|
shrl $2, %eax
|
|
# endif
|
|
VZEROUPPER_RETURN
|
|
|
|
# ifdef USE_AS_STRNLEN
|
|
L(zero):
|
|
xorl %eax, %eax
|
|
ret
|
|
|
|
.p2align 4
|
|
L(first_vec_x0):
|
|
/* Set bit for max len so that tzcnt will return min of max len
|
|
and position of first match. */
|
|
# ifdef USE_AS_WCSLEN
|
|
/* NB: Multiply length by 4 to get byte count. */
|
|
sall $2, %esi
|
|
# endif
|
|
btsq %rsi, %rax
|
|
tzcntl %eax, %eax
|
|
# ifdef USE_AS_WCSLEN
|
|
/* NB: Divide bytes by 4 to get wchar_t count. */
|
|
shrl $2, %eax
|
|
# endif
|
|
VZEROUPPER_RETURN
|
|
# endif
|
|
|
|
.p2align 4
|
|
L(first_vec_x1):
|
|
tzcntl %eax, %eax
|
|
/* Safe to use 32 bit instructions as these are only called for
|
|
size = [1, 159]. */
|
|
# ifdef USE_AS_STRNLEN
|
|
/* Use ecx which was computed earlier to compute correct value.
|
|
*/
|
|
# ifdef USE_AS_WCSLEN
|
|
leal -(VEC_SIZE * 4 + 1)(%rax, %rcx, 4), %eax
|
|
# else
|
|
subl $(VEC_SIZE * 4 + 1), %ecx
|
|
addl %ecx, %eax
|
|
# endif
|
|
# else
|
|
subl %edx, %edi
|
|
incl %edi
|
|
addl %edi, %eax
|
|
# endif
|
|
# ifdef USE_AS_WCSLEN
|
|
/* NB: Divide bytes by 4 to get wchar_t count. */
|
|
shrl $2, %eax
|
|
# endif
|
|
VZEROUPPER_RETURN
|
|
|
|
.p2align 4
|
|
L(first_vec_x2):
|
|
tzcntl %eax, %eax
|
|
/* Safe to use 32 bit instructions as these are only called for
|
|
size = [1, 159]. */
|
|
# ifdef USE_AS_STRNLEN
|
|
/* Use ecx which was computed earlier to compute correct value.
|
|
*/
|
|
# ifdef USE_AS_WCSLEN
|
|
leal -(VEC_SIZE * 3 + 1)(%rax, %rcx, 4), %eax
|
|
# else
|
|
subl $(VEC_SIZE * 3 + 1), %ecx
|
|
addl %ecx, %eax
|
|
# endif
|
|
# else
|
|
subl %edx, %edi
|
|
addl $(VEC_SIZE + 1), %edi
|
|
addl %edi, %eax
|
|
# endif
|
|
# ifdef USE_AS_WCSLEN
|
|
/* NB: Divide bytes by 4 to get wchar_t count. */
|
|
shrl $2, %eax
|
|
# endif
|
|
VZEROUPPER_RETURN
|
|
|
|
.p2align 4
|
|
L(first_vec_x3):
|
|
tzcntl %eax, %eax
|
|
/* Safe to use 32 bit instructions as these are only called for
|
|
size = [1, 159]. */
|
|
# ifdef USE_AS_STRNLEN
|
|
/* Use ecx which was computed earlier to compute correct value.
|
|
*/
|
|
# ifdef USE_AS_WCSLEN
|
|
leal -(VEC_SIZE * 2 + 1)(%rax, %rcx, 4), %eax
|
|
# else
|
|
subl $(VEC_SIZE * 2 + 1), %ecx
|
|
addl %ecx, %eax
|
|
# endif
|
|
# else
|
|
subl %edx, %edi
|
|
addl $(VEC_SIZE * 2 + 1), %edi
|
|
addl %edi, %eax
|
|
# endif
|
|
# ifdef USE_AS_WCSLEN
|
|
/* NB: Divide bytes by 4 to get wchar_t count. */
|
|
shrl $2, %eax
|
|
# endif
|
|
VZEROUPPER_RETURN
|
|
|
|
.p2align 4
|
|
L(first_vec_x4):
|
|
tzcntl %eax, %eax
|
|
/* Safe to use 32 bit instructions as these are only called for
|
|
size = [1, 159]. */
|
|
# ifdef USE_AS_STRNLEN
|
|
/* Use ecx which was computed earlier to compute correct value.
|
|
*/
|
|
# ifdef USE_AS_WCSLEN
|
|
leal -(VEC_SIZE * 1 + 1)(%rax, %rcx, 4), %eax
|
|
# else
|
|
subl $(VEC_SIZE + 1), %ecx
|
|
addl %ecx, %eax
|
|
# endif
|
|
# else
|
|
subl %edx, %edi
|
|
addl $(VEC_SIZE * 3 + 1), %edi
|
|
addl %edi, %eax
|
|
# endif
|
|
# ifdef USE_AS_WCSLEN
|
|
/* NB: Divide bytes by 4 to get wchar_t count. */
|
|
shrl $2, %eax
|
|
# endif
|
|
VZEROUPPER_RETURN
|
|
|
|
.p2align 5
|
|
L(aligned_more):
|
|
/* Align data to VEC_SIZE - 1. This is the same number of
|
|
instructions as using andq with -VEC_SIZE but saves 4 bytes of
|
|
code on the x4 check. */
|
|
orq $(VEC_SIZE - 1), %rdi
|
|
L(cross_page_continue):
|
|
/* Check the first 4 * VEC_SIZE. Only one VEC_SIZE at a time
|
|
since data is only aligned to VEC_SIZE. */
|
|
# ifdef USE_AS_STRNLEN
|
|
/* + 1 because rdi is aligned to VEC_SIZE - 1. + CHAR_SIZE
|
|
because it simplies the logic in last_4x_vec_or_less. */
|
|
leaq (VEC_SIZE * 4 + CHAR_SIZE + 1)(%rdi), %rcx
|
|
subq %rdx, %rcx
|
|
# ifdef USE_AS_WCSLEN
|
|
/* NB: Divide bytes by 4 to get the wchar_t count. */
|
|
sarl $2, %ecx
|
|
# endif
|
|
# endif
|
|
/* Load first VEC regardless. */
|
|
VPCMPEQ 1(%rdi), %ymm0, %ymm1
|
|
# ifdef USE_AS_STRNLEN
|
|
/* Adjust length. If near end handle specially. */
|
|
subq %rcx, %rsi
|
|
jb L(last_4x_vec_or_less)
|
|
# endif
|
|
vpmovmskb %ymm1, %eax
|
|
testl %eax, %eax
|
|
jnz L(first_vec_x1)
|
|
|
|
VPCMPEQ (VEC_SIZE + 1)(%rdi), %ymm0, %ymm1
|
|
vpmovmskb %ymm1, %eax
|
|
testl %eax, %eax
|
|
jnz L(first_vec_x2)
|
|
|
|
VPCMPEQ (VEC_SIZE * 2 + 1)(%rdi), %ymm0, %ymm1
|
|
vpmovmskb %ymm1, %eax
|
|
testl %eax, %eax
|
|
jnz L(first_vec_x3)
|
|
|
|
VPCMPEQ (VEC_SIZE * 3 + 1)(%rdi), %ymm0, %ymm1
|
|
vpmovmskb %ymm1, %eax
|
|
testl %eax, %eax
|
|
jnz L(first_vec_x4)
|
|
|
|
/* Align data to VEC_SIZE * 4 - 1. */
|
|
# ifdef USE_AS_STRNLEN
|
|
/* Before adjusting length check if at last VEC_SIZE * 4. */
|
|
cmpq $(CHAR_PER_VEC * 4 - 1), %rsi
|
|
jbe L(last_4x_vec_or_less_load)
|
|
incq %rdi
|
|
movl %edi, %ecx
|
|
orq $(VEC_SIZE * 4 - 1), %rdi
|
|
andl $(VEC_SIZE * 4 - 1), %ecx
|
|
# ifdef USE_AS_WCSLEN
|
|
/* NB: Divide bytes by 4 to get the wchar_t count. */
|
|
sarl $2, %ecx
|
|
# endif
|
|
/* Readjust length. */
|
|
addq %rcx, %rsi
|
|
# else
|
|
incq %rdi
|
|
orq $(VEC_SIZE * 4 - 1), %rdi
|
|
# endif
|
|
/* Compare 4 * VEC at a time forward. */
|
|
.p2align 4
|
|
L(loop_4x_vec):
|
|
# ifdef USE_AS_STRNLEN
|
|
/* Break if at end of length. */
|
|
subq $(CHAR_PER_VEC * 4), %rsi
|
|
jb L(last_4x_vec_or_less_cmpeq)
|
|
# endif
|
|
/* Save some code size by microfusing VPMINU with the load.
|
|
Since the matches in ymm2/ymm4 can only be returned if there
|
|
where no matches in ymm1/ymm3 respectively there is no issue
|
|
with overlap. */
|
|
vmovdqa 1(%rdi), %ymm1
|
|
VPMINU (VEC_SIZE + 1)(%rdi), %ymm1, %ymm2
|
|
vmovdqa (VEC_SIZE * 2 + 1)(%rdi), %ymm3
|
|
VPMINU (VEC_SIZE * 3 + 1)(%rdi), %ymm3, %ymm4
|
|
|
|
VPMINU %ymm2, %ymm4, %ymm5
|
|
VPCMPEQ %ymm5, %ymm0, %ymm5
|
|
vpmovmskb %ymm5, %ecx
|
|
|
|
subq $-(VEC_SIZE * 4), %rdi
|
|
testl %ecx, %ecx
|
|
jz L(loop_4x_vec)
|
|
|
|
|
|
VPCMPEQ %ymm1, %ymm0, %ymm1
|
|
vpmovmskb %ymm1, %eax
|
|
subq %rdx, %rdi
|
|
testl %eax, %eax
|
|
jnz L(last_vec_return_x0)
|
|
|
|
VPCMPEQ %ymm2, %ymm0, %ymm2
|
|
vpmovmskb %ymm2, %eax
|
|
testl %eax, %eax
|
|
jnz L(last_vec_return_x1)
|
|
|
|
/* Combine last 2 VEC. */
|
|
VPCMPEQ %ymm3, %ymm0, %ymm3
|
|
vpmovmskb %ymm3, %eax
|
|
/* rcx has combined result from all 4 VEC. It will only be used
|
|
if the first 3 other VEC all did not contain a match. */
|
|
salq $32, %rcx
|
|
orq %rcx, %rax
|
|
tzcntq %rax, %rax
|
|
subq $(VEC_SIZE * 2 - 1), %rdi
|
|
addq %rdi, %rax
|
|
# ifdef USE_AS_WCSLEN
|
|
/* NB: Divide bytes by 4 to get wchar_t count. */
|
|
shrq $2, %rax
|
|
# endif
|
|
VZEROUPPER_RETURN
|
|
|
|
|
|
# ifdef USE_AS_STRNLEN
|
|
.p2align 4
|
|
L(last_4x_vec_or_less_load):
|
|
/* Depending on entry adjust rdi / prepare first VEC in ymm1.
|
|
*/
|
|
subq $-(VEC_SIZE * 4), %rdi
|
|
L(last_4x_vec_or_less_cmpeq):
|
|
VPCMPEQ 1(%rdi), %ymm0, %ymm1
|
|
L(last_4x_vec_or_less):
|
|
# ifdef USE_AS_WCSLEN
|
|
/* NB: Multiply length by 4 to get byte count. */
|
|
sall $2, %esi
|
|
# endif
|
|
vpmovmskb %ymm1, %eax
|
|
/* If remaining length > VEC_SIZE * 2. This works if esi is off
|
|
by VEC_SIZE * 4. */
|
|
testl $(VEC_SIZE * 2), %esi
|
|
jnz L(last_4x_vec)
|
|
|
|
/* length may have been negative or positive by an offset of
|
|
VEC_SIZE * 4 depending on where this was called from. This fixes
|
|
that. */
|
|
andl $(VEC_SIZE * 4 - 1), %esi
|
|
testl %eax, %eax
|
|
jnz L(last_vec_x1_check)
|
|
|
|
subl $VEC_SIZE, %esi
|
|
jb L(max)
|
|
|
|
VPCMPEQ (VEC_SIZE + 1)(%rdi), %ymm0, %ymm1
|
|
vpmovmskb %ymm1, %eax
|
|
tzcntl %eax, %eax
|
|
/* Check the end of data. */
|
|
cmpl %eax, %esi
|
|
jb L(max)
|
|
subq %rdx, %rdi
|
|
addl $(VEC_SIZE + 1), %eax
|
|
addq %rdi, %rax
|
|
# ifdef USE_AS_WCSLEN
|
|
/* NB: Divide bytes by 4 to get wchar_t count. */
|
|
shrq $2, %rax
|
|
# endif
|
|
VZEROUPPER_RETURN
|
|
# endif
|
|
|
|
.p2align 4
|
|
L(last_vec_return_x0):
|
|
tzcntl %eax, %eax
|
|
subq $(VEC_SIZE * 4 - 1), %rdi
|
|
addq %rdi, %rax
|
|
# ifdef USE_AS_WCSLEN
|
|
/* NB: Divide bytes by 4 to get wchar_t count. */
|
|
shrq $2, %rax
|
|
# endif
|
|
VZEROUPPER_RETURN
|
|
|
|
.p2align 4
|
|
L(last_vec_return_x1):
|
|
tzcntl %eax, %eax
|
|
subq $(VEC_SIZE * 3 - 1), %rdi
|
|
addq %rdi, %rax
|
|
# ifdef USE_AS_WCSLEN
|
|
/* NB: Divide bytes by 4 to get wchar_t count. */
|
|
shrq $2, %rax
|
|
# endif
|
|
VZEROUPPER_RETURN
|
|
|
|
# ifdef USE_AS_STRNLEN
|
|
.p2align 4
|
|
L(last_vec_x1_check):
|
|
|
|
tzcntl %eax, %eax
|
|
/* Check the end of data. */
|
|
cmpl %eax, %esi
|
|
jb L(max)
|
|
subq %rdx, %rdi
|
|
incl %eax
|
|
addq %rdi, %rax
|
|
# ifdef USE_AS_WCSLEN
|
|
/* NB: Divide bytes by 4 to get wchar_t count. */
|
|
shrq $2, %rax
|
|
# endif
|
|
VZEROUPPER_RETURN
|
|
|
|
L(max):
|
|
movq %r8, %rax
|
|
VZEROUPPER_RETURN
|
|
|
|
.p2align 4
|
|
L(last_4x_vec):
|
|
/* Test first 2x VEC normally. */
|
|
testl %eax, %eax
|
|
jnz L(last_vec_x1)
|
|
|
|
VPCMPEQ (VEC_SIZE + 1)(%rdi), %ymm0, %ymm1
|
|
vpmovmskb %ymm1, %eax
|
|
testl %eax, %eax
|
|
jnz L(last_vec_x2)
|
|
|
|
/* Normalize length. */
|
|
andl $(VEC_SIZE * 4 - 1), %esi
|
|
VPCMPEQ (VEC_SIZE * 2 + 1)(%rdi), %ymm0, %ymm1
|
|
vpmovmskb %ymm1, %eax
|
|
testl %eax, %eax
|
|
jnz L(last_vec_x3)
|
|
|
|
subl $(VEC_SIZE * 3), %esi
|
|
jb L(max)
|
|
|
|
VPCMPEQ (VEC_SIZE * 3 + 1)(%rdi), %ymm0, %ymm1
|
|
vpmovmskb %ymm1, %eax
|
|
tzcntl %eax, %eax
|
|
/* Check the end of data. */
|
|
cmpl %eax, %esi
|
|
jb L(max)
|
|
subq %rdx, %rdi
|
|
addl $(VEC_SIZE * 3 + 1), %eax
|
|
addq %rdi, %rax
|
|
# ifdef USE_AS_WCSLEN
|
|
/* NB: Divide bytes by 4 to get wchar_t count. */
|
|
shrq $2, %rax
|
|
# endif
|
|
VZEROUPPER_RETURN
|
|
|
|
|
|
.p2align 4
|
|
L(last_vec_x1):
|
|
/* essentially duplicates of first_vec_x1 but use 64 bit
|
|
instructions. */
|
|
tzcntl %eax, %eax
|
|
subq %rdx, %rdi
|
|
incl %eax
|
|
addq %rdi, %rax
|
|
# ifdef USE_AS_WCSLEN
|
|
/* NB: Divide bytes by 4 to get wchar_t count. */
|
|
shrq $2, %rax
|
|
# endif
|
|
VZEROUPPER_RETURN
|
|
|
|
.p2align 4
|
|
L(last_vec_x2):
|
|
/* essentially duplicates of first_vec_x1 but use 64 bit
|
|
instructions. */
|
|
tzcntl %eax, %eax
|
|
subq %rdx, %rdi
|
|
addl $(VEC_SIZE + 1), %eax
|
|
addq %rdi, %rax
|
|
# ifdef USE_AS_WCSLEN
|
|
/* NB: Divide bytes by 4 to get wchar_t count. */
|
|
shrq $2, %rax
|
|
# endif
|
|
VZEROUPPER_RETURN
|
|
|
|
.p2align 4
|
|
L(last_vec_x3):
|
|
tzcntl %eax, %eax
|
|
subl $(VEC_SIZE * 2), %esi
|
|
/* Check the end of data. */
|
|
cmpl %eax, %esi
|
|
jb L(max_end)
|
|
subq %rdx, %rdi
|
|
addl $(VEC_SIZE * 2 + 1), %eax
|
|
addq %rdi, %rax
|
|
# ifdef USE_AS_WCSLEN
|
|
/* NB: Divide bytes by 4 to get wchar_t count. */
|
|
shrq $2, %rax
|
|
# endif
|
|
VZEROUPPER_RETURN
|
|
L(max_end):
|
|
movq %r8, %rax
|
|
VZEROUPPER_RETURN
|
|
# endif
|
|
|
|
/* Cold case for crossing page with first load. */
|
|
.p2align 4
|
|
L(cross_page_boundary):
|
|
/* Align data to VEC_SIZE - 1. */
|
|
orq $(VEC_SIZE - 1), %rdi
|
|
VPCMPEQ -(VEC_SIZE - 1)(%rdi), %ymm0, %ymm1
|
|
vpmovmskb %ymm1, %eax
|
|
/* Remove the leading bytes. sarxl only uses bits [5:0] of COUNT
|
|
so no need to manually mod rdx. */
|
|
sarxl %edx, %eax, %eax
|
|
# ifdef USE_AS_STRNLEN
|
|
testl %eax, %eax
|
|
jnz L(cross_page_less_vec)
|
|
leaq 1(%rdi), %rcx
|
|
subq %rdx, %rcx
|
|
# ifdef USE_AS_WCSLEN
|
|
/* NB: Divide bytes by 4 to get wchar_t count. */
|
|
shrl $2, %ecx
|
|
# endif
|
|
/* Check length. */
|
|
cmpq %rsi, %rcx
|
|
jb L(cross_page_continue)
|
|
movq %r8, %rax
|
|
# else
|
|
testl %eax, %eax
|
|
jz L(cross_page_continue)
|
|
tzcntl %eax, %eax
|
|
# ifdef USE_AS_WCSLEN
|
|
/* NB: Divide length by 4 to get wchar_t count. */
|
|
shrl $2, %eax
|
|
# endif
|
|
# endif
|
|
L(return_vzeroupper):
|
|
ZERO_UPPER_VEC_REGISTERS_RETURN
|
|
|
|
# ifdef USE_AS_STRNLEN
|
|
.p2align 4
|
|
L(cross_page_less_vec):
|
|
tzcntl %eax, %eax
|
|
# ifdef USE_AS_WCSLEN
|
|
/* NB: Multiply length by 4 to get byte count. */
|
|
sall $2, %esi
|
|
# endif
|
|
cmpq %rax, %rsi
|
|
cmovb %esi, %eax
|
|
# ifdef USE_AS_WCSLEN
|
|
shrl $2, %eax
|
|
# endif
|
|
VZEROUPPER_RETURN
|
|
# endif
|
|
|
|
END (STRLEN)
|
|
#endif
|