glibc/sysdeps/x86_64/multiarch/memchr-avx2.S
Paul Eggert 581c785bf3 Update copyright dates with scripts/update-copyrights
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
2022-01-01 11:40:24 -08:00

433 lines
9.7 KiB
ArmAsm

/* memchr/wmemchr 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 MEMCHR
# define MEMCHR __memchr_avx2
# endif
# ifdef USE_AS_WMEMCHR
# define VPCMPEQ vpcmpeqd
# define VPBROADCAST vpbroadcastd
# define CHAR_SIZE 4
# else
# define VPCMPEQ vpcmpeqb
# define VPBROADCAST vpbroadcastb
# define CHAR_SIZE 1
# endif
# ifdef USE_AS_RAWMEMCHR
# define ERAW_PTR_REG ecx
# define RRAW_PTR_REG rcx
# define ALGN_PTR_REG rdi
# else
# define ERAW_PTR_REG edi
# define RRAW_PTR_REG rdi
# define ALGN_PTR_REG rcx
# 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 (MEMCHR)
# ifndef USE_AS_RAWMEMCHR
/* Check for zero length. */
# ifdef __ILP32__
/* Clear upper bits. */
and %RDX_LP, %RDX_LP
# else
test %RDX_LP, %RDX_LP
# endif
jz L(null)
# endif
/* Broadcast CHAR to YMMMATCH. */
vmovd %esi, %xmm0
VPBROADCAST %xmm0, %ymm0
/* Check if we may cross page boundary with one vector load. */
movl %edi, %eax
andl $(PAGE_SIZE - 1), %eax
cmpl $(PAGE_SIZE - VEC_SIZE), %eax
ja L(cross_page_boundary)
/* Check the first VEC_SIZE bytes. */
VPCMPEQ (%rdi), %ymm0, %ymm1
vpmovmskb %ymm1, %eax
# ifndef USE_AS_RAWMEMCHR
/* If length < CHAR_PER_VEC handle special. */
cmpq $CHAR_PER_VEC, %rdx
jbe L(first_vec_x0)
# endif
testl %eax, %eax
jz L(aligned_more)
tzcntl %eax, %eax
addq %rdi, %rax
VZEROUPPER_RETURN
# ifndef USE_AS_RAWMEMCHR
.p2align 5
L(first_vec_x0):
/* Check if first match was before length. */
tzcntl %eax, %eax
# ifdef USE_AS_WMEMCHR
/* NB: Multiply length by 4 to get byte count. */
sall $2, %edx
# endif
xorl %ecx, %ecx
cmpl %eax, %edx
leaq (%rdi, %rax), %rax
cmovle %rcx, %rax
VZEROUPPER_RETURN
L(null):
xorl %eax, %eax
ret
# endif
.p2align 4
L(cross_page_boundary):
/* Save pointer before aligning as its original value is
necessary for computer return address if byte is found or
adjusting length if it is not and this is memchr. */
movq %rdi, %rcx
/* Align data to VEC_SIZE - 1. ALGN_PTR_REG is rcx for memchr
and rdi for rawmemchr. */
orq $(VEC_SIZE - 1), %ALGN_PTR_REG
VPCMPEQ -(VEC_SIZE - 1)(%ALGN_PTR_REG), %ymm0, %ymm1
vpmovmskb %ymm1, %eax
# ifndef USE_AS_RAWMEMCHR
/* Calculate length until end of page (length checked for a
match). */
leaq 1(%ALGN_PTR_REG), %rsi
subq %RRAW_PTR_REG, %rsi
# ifdef USE_AS_WMEMCHR
/* NB: Divide bytes by 4 to get wchar_t count. */
shrl $2, %esi
# endif
# endif
/* Remove the leading bytes. */
sarxl %ERAW_PTR_REG, %eax, %eax
# ifndef USE_AS_RAWMEMCHR
/* Check the end of data. */
cmpq %rsi, %rdx
jbe L(first_vec_x0)
# endif
testl %eax, %eax
jz L(cross_page_continue)
tzcntl %eax, %eax
addq %RRAW_PTR_REG, %rax
L(return_vzeroupper):
ZERO_UPPER_VEC_REGISTERS_RETURN
.p2align 4
L(first_vec_x1):
tzcntl %eax, %eax
incq %rdi
addq %rdi, %rax
VZEROUPPER_RETURN
.p2align 4
L(first_vec_x2):
tzcntl %eax, %eax
addq $(VEC_SIZE + 1), %rdi
addq %rdi, %rax
VZEROUPPER_RETURN
.p2align 4
L(first_vec_x3):
tzcntl %eax, %eax
addq $(VEC_SIZE * 2 + 1), %rdi
addq %rdi, %rax
VZEROUPPER_RETURN
.p2align 4
L(first_vec_x4):
tzcntl %eax, %eax
addq $(VEC_SIZE * 3 + 1), %rdi
addq %rdi, %rax
VZEROUPPER_RETURN
.p2align 4
L(aligned_more):
/* Check the first 4 * VEC_SIZE. Only one VEC_SIZE at a time
since data is only aligned to VEC_SIZE. */
# ifndef USE_AS_RAWMEMCHR
L(cross_page_continue):
/* Align data to VEC_SIZE - 1. */
xorl %ecx, %ecx
subl %edi, %ecx
orq $(VEC_SIZE - 1), %rdi
/* esi is for adjusting length to see if near the end. */
leal (VEC_SIZE * 4 + 1)(%rdi, %rcx), %esi
# ifdef USE_AS_WMEMCHR
/* NB: Divide bytes by 4 to get the wchar_t count. */
sarl $2, %esi
# endif
# else
orq $(VEC_SIZE - 1), %rdi
L(cross_page_continue):
# endif
/* Load first VEC regardless. */
VPCMPEQ 1(%rdi), %ymm0, %ymm1
vpmovmskb %ymm1, %eax
# ifndef USE_AS_RAWMEMCHR
/* Adjust length. If near end handle specially. */
subq %rsi, %rdx
jbe L(last_4x_vec_or_less)
# endif
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)
# ifndef USE_AS_RAWMEMCHR
/* Check if at last VEC_SIZE * 4 length. */
subq $(CHAR_PER_VEC * 4), %rdx
jbe L(last_4x_vec_or_less_cmpeq)
/* Align data to VEC_SIZE * 4 - 1 for the loop and readjust
length. */
incq %rdi
movl %edi, %ecx
orq $(VEC_SIZE * 4 - 1), %rdi
andl $(VEC_SIZE * 4 - 1), %ecx
# ifdef USE_AS_WMEMCHR
/* NB: Divide bytes by 4 to get the wchar_t count. */
sarl $2, %ecx
# endif
addq %rcx, %rdx
# else
/* Align data to VEC_SIZE * 4 - 1 for loop. */
incq %rdi
orq $(VEC_SIZE * 4 - 1), %rdi
# endif
/* Compare 4 * VEC at a time forward. */
.p2align 4
L(loop_4x_vec):
VPCMPEQ 1(%rdi), %ymm0, %ymm1
VPCMPEQ (VEC_SIZE + 1)(%rdi), %ymm0, %ymm2
VPCMPEQ (VEC_SIZE * 2 + 1)(%rdi), %ymm0, %ymm3
VPCMPEQ (VEC_SIZE * 3 + 1)(%rdi), %ymm0, %ymm4
vpor %ymm1, %ymm2, %ymm5
vpor %ymm3, %ymm4, %ymm6
vpor %ymm5, %ymm6, %ymm5
vpmovmskb %ymm5, %ecx
# ifdef USE_AS_RAWMEMCHR
subq $-(VEC_SIZE * 4), %rdi
testl %ecx, %ecx
jz L(loop_4x_vec)
# else
testl %ecx, %ecx
jnz L(loop_4x_vec_end)
subq $-(VEC_SIZE * 4), %rdi
subq $(CHAR_PER_VEC * 4), %rdx
ja L(loop_4x_vec)
/* Fall through into less than 4 remaining vectors of length
case. */
VPCMPEQ (VEC_SIZE * 0 + 1)(%rdi), %ymm0, %ymm1
vpmovmskb %ymm1, %eax
.p2align 4
L(last_4x_vec_or_less):
# ifdef USE_AS_WMEMCHR
/* NB: Multiply length by 4 to get byte count. */
sall $2, %edx
# endif
/* Check if first VEC contained match. */
testl %eax, %eax
jnz L(first_vec_x1_check)
/* If remaining length > VEC_SIZE * 2. */
addl $(VEC_SIZE * 2), %edx
jg L(last_4x_vec)
L(last_2x_vec):
/* If remaining length < VEC_SIZE. */
addl $VEC_SIZE, %edx
jle L(zero_end)
/* Check VEC2 and compare any match with remaining length. */
VPCMPEQ (VEC_SIZE + 1)(%rdi), %ymm0, %ymm1
vpmovmskb %ymm1, %eax
tzcntl %eax, %eax
cmpl %eax, %edx
jbe L(set_zero_end)
addq $(VEC_SIZE + 1), %rdi
addq %rdi, %rax
L(zero_end):
VZEROUPPER_RETURN
.p2align 4
L(loop_4x_vec_end):
# endif
/* rawmemchr will fall through into this if match was found in
loop. */
vpmovmskb %ymm1, %eax
testl %eax, %eax
jnz L(last_vec_x1_return)
vpmovmskb %ymm2, %eax
testl %eax, %eax
jnz L(last_vec_x2_return)
vpmovmskb %ymm3, %eax
/* Combine VEC3 matches (eax) with VEC4 matches (ecx). */
salq $32, %rcx
orq %rcx, %rax
tzcntq %rax, %rax
# ifdef USE_AS_RAWMEMCHR
subq $(VEC_SIZE * 2 - 1), %rdi
# else
subq $-(VEC_SIZE * 2 + 1), %rdi
# endif
addq %rdi, %rax
VZEROUPPER_RETURN
# ifndef USE_AS_RAWMEMCHR
.p2align 4
L(first_vec_x1_check):
tzcntl %eax, %eax
/* Adjust length. */
subl $-(VEC_SIZE * 4), %edx
/* Check if match within remaining length. */
cmpl %eax, %edx
jbe L(set_zero_end)
incq %rdi
addq %rdi, %rax
VZEROUPPER_RETURN
.p2align 4
L(set_zero_end):
xorl %eax, %eax
VZEROUPPER_RETURN
# endif
.p2align 4
L(last_vec_x1_return):
tzcntl %eax, %eax
# ifdef USE_AS_RAWMEMCHR
subq $(VEC_SIZE * 4 - 1), %rdi
# else
incq %rdi
# endif
addq %rdi, %rax
VZEROUPPER_RETURN
.p2align 4
L(last_vec_x2_return):
tzcntl %eax, %eax
# ifdef USE_AS_RAWMEMCHR
subq $(VEC_SIZE * 3 - 1), %rdi
# else
subq $-(VEC_SIZE + 1), %rdi
# endif
addq %rdi, %rax
VZEROUPPER_RETURN
# ifndef USE_AS_RAWMEMCHR
.p2align 4
L(last_4x_vec_or_less_cmpeq):
VPCMPEQ (VEC_SIZE * 4 + 1)(%rdi), %ymm0, %ymm1
vpmovmskb %ymm1, %eax
# ifdef USE_AS_WMEMCHR
/* NB: Multiply length by 4 to get byte count. */
sall $2, %edx
# endif
subq $-(VEC_SIZE * 4), %rdi
/* Check first VEC regardless. */
testl %eax, %eax
jnz L(first_vec_x1_check)
/* If remaining length <= CHAR_PER_VEC * 2. */
addl $(VEC_SIZE * 2), %edx
jle L(last_2x_vec)
.p2align 4
L(last_4x_vec):
VPCMPEQ (VEC_SIZE + 1)(%rdi), %ymm0, %ymm1
vpmovmskb %ymm1, %eax
testl %eax, %eax
jnz L(last_vec_x2_return)
VPCMPEQ (VEC_SIZE * 2 + 1)(%rdi), %ymm0, %ymm1
vpmovmskb %ymm1, %eax
/* Create mask for possible matches within remaining length. */
movq $-1, %rcx
bzhiq %rdx, %rcx, %rcx
/* Test matches in data against length match. */
andl %ecx, %eax
jnz L(last_vec_x3)
/* if remaining length <= VEC_SIZE * 3 (Note this is after
remaining length was found to be > VEC_SIZE * 2. */
subl $VEC_SIZE, %edx
jbe L(zero_end2)
VPCMPEQ (VEC_SIZE * 3 + 1)(%rdi), %ymm0, %ymm1
vpmovmskb %ymm1, %eax
/* Shift remaining length mask for last VEC. */
shrq $32, %rcx
andl %ecx, %eax
jz L(zero_end2)
tzcntl %eax, %eax
addq $(VEC_SIZE * 3 + 1), %rdi
addq %rdi, %rax
L(zero_end2):
VZEROUPPER_RETURN
.p2align 4
L(last_vec_x3):
tzcntl %eax, %eax
subq $-(VEC_SIZE * 2 + 1), %rdi
addq %rdi, %rax
VZEROUPPER_RETURN
# endif
END (MEMCHR)
#endif