mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-25 14:30:06 +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.
430 lines
9.4 KiB
ArmAsm
430 lines
9.4 KiB
ArmAsm
/* memcmp/wmemcmp optimized with AVX2.
|
|
Copyright (C) 2017-2018 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/>. */
|
|
|
|
#if IS_IN (libc)
|
|
|
|
/* memcmp/wmemcmp is implemented as:
|
|
1. For size from 2 to 7 bytes, load as big endian with movbe and bswap
|
|
to avoid branches.
|
|
2. Use overlapping compare to avoid branch.
|
|
3. Use vector compare when size >= 4 bytes for memcmp or size >= 8
|
|
bytes for wmemcmp.
|
|
4. If size is 8 * VEC_SIZE or less, unroll the loop.
|
|
5. Compare 4 * VEC_SIZE at a time with the aligned first memory
|
|
area.
|
|
6. Use 2 vector compares when size is 2 * VEC_SIZE or less.
|
|
7. Use 4 vector compares when size is 4 * VEC_SIZE or less.
|
|
8. Use 8 vector compares when size is 8 * VEC_SIZE or less. */
|
|
|
|
# include <sysdep.h>
|
|
|
|
# ifndef MEMCMP
|
|
# define MEMCMP __memcmp_avx2_movbe
|
|
# endif
|
|
|
|
# ifdef USE_AS_WMEMCMP
|
|
# define VPCMPEQ vpcmpeqd
|
|
# else
|
|
# define VPCMPEQ vpcmpeqb
|
|
# endif
|
|
|
|
# ifndef VZEROUPPER
|
|
# define VZEROUPPER vzeroupper
|
|
# endif
|
|
|
|
# define VEC_SIZE 32
|
|
# define VEC_MASK ((1 << VEC_SIZE) - 1)
|
|
|
|
/* Warning!
|
|
wmemcmp has to use SIGNED comparison for elements.
|
|
memcmp has to use UNSIGNED comparison for elemnts.
|
|
*/
|
|
|
|
.section .text.avx,"ax",@progbits
|
|
ENTRY (MEMCMP)
|
|
# ifdef USE_AS_WMEMCMP
|
|
shl $2, %rdx
|
|
# endif
|
|
cmpq $VEC_SIZE, %rdx
|
|
jb L(less_vec)
|
|
|
|
/* From VEC to 2 * VEC. No branch when size == VEC_SIZE. */
|
|
vmovdqu (%rsi), %ymm2
|
|
VPCMPEQ (%rdi), %ymm2, %ymm2
|
|
vpmovmskb %ymm2, %eax
|
|
subl $VEC_MASK, %eax
|
|
jnz L(first_vec)
|
|
|
|
cmpq $(VEC_SIZE * 2), %rdx
|
|
jbe L(last_vec)
|
|
|
|
VPCMPEQ %ymm0, %ymm0, %ymm0
|
|
/* More than 2 * VEC. */
|
|
cmpq $(VEC_SIZE * 8), %rdx
|
|
ja L(more_8x_vec)
|
|
cmpq $(VEC_SIZE * 4), %rdx
|
|
jb L(last_4x_vec)
|
|
|
|
/* From 4 * VEC to 8 * VEC, inclusively. */
|
|
vmovdqu (%rsi), %ymm1
|
|
VPCMPEQ (%rdi), %ymm1, %ymm1
|
|
|
|
vmovdqu VEC_SIZE(%rsi), %ymm2
|
|
VPCMPEQ VEC_SIZE(%rdi), %ymm2, %ymm2
|
|
|
|
vmovdqu (VEC_SIZE * 2)(%rsi), %ymm3
|
|
VPCMPEQ (VEC_SIZE * 2)(%rdi), %ymm3, %ymm3
|
|
|
|
vmovdqu (VEC_SIZE * 3)(%rsi), %ymm4
|
|
VPCMPEQ (VEC_SIZE * 3)(%rdi), %ymm4, %ymm4
|
|
|
|
vpand %ymm1, %ymm2, %ymm5
|
|
vpand %ymm3, %ymm4, %ymm6
|
|
vpand %ymm5, %ymm6, %ymm5
|
|
|
|
vptest %ymm0, %ymm5
|
|
jnc L(4x_vec_end)
|
|
|
|
leaq -(4 * VEC_SIZE)(%rdi, %rdx), %rdi
|
|
leaq -(4 * VEC_SIZE)(%rsi, %rdx), %rsi
|
|
vmovdqu (%rsi), %ymm1
|
|
VPCMPEQ (%rdi), %ymm1, %ymm1
|
|
|
|
vmovdqu VEC_SIZE(%rsi), %ymm2
|
|
VPCMPEQ VEC_SIZE(%rdi), %ymm2, %ymm2
|
|
vpand %ymm2, %ymm1, %ymm5
|
|
|
|
vmovdqu (VEC_SIZE * 2)(%rsi), %ymm3
|
|
VPCMPEQ (VEC_SIZE * 2)(%rdi), %ymm3, %ymm3
|
|
vpand %ymm3, %ymm5, %ymm5
|
|
|
|
vmovdqu (VEC_SIZE * 3)(%rsi), %ymm4
|
|
VPCMPEQ (VEC_SIZE * 3)(%rdi), %ymm4, %ymm4
|
|
vpand %ymm4, %ymm5, %ymm5
|
|
|
|
vptest %ymm0, %ymm5
|
|
jnc L(4x_vec_end)
|
|
xorl %eax, %eax
|
|
VZEROUPPER
|
|
ret
|
|
|
|
.p2align 4
|
|
L(last_2x_vec):
|
|
/* From VEC to 2 * VEC. No branch when size == VEC_SIZE. */
|
|
vmovdqu (%rsi), %ymm2
|
|
VPCMPEQ (%rdi), %ymm2, %ymm2
|
|
vpmovmskb %ymm2, %eax
|
|
subl $VEC_MASK, %eax
|
|
jnz L(first_vec)
|
|
|
|
L(last_vec):
|
|
/* Use overlapping loads to avoid branches. */
|
|
leaq -VEC_SIZE(%rdi, %rdx), %rdi
|
|
leaq -VEC_SIZE(%rsi, %rdx), %rsi
|
|
vmovdqu (%rsi), %ymm2
|
|
VPCMPEQ (%rdi), %ymm2, %ymm2
|
|
vpmovmskb %ymm2, %eax
|
|
subl $VEC_MASK, %eax
|
|
jnz L(first_vec)
|
|
VZEROUPPER
|
|
ret
|
|
|
|
.p2align 4
|
|
L(first_vec):
|
|
/* A byte or int32 is different within 16 or 32 bytes. */
|
|
tzcntl %eax, %ecx
|
|
# ifdef USE_AS_WMEMCMP
|
|
xorl %eax, %eax
|
|
movl (%rdi, %rcx), %edx
|
|
cmpl (%rsi, %rcx), %edx
|
|
L(wmemcmp_return):
|
|
setl %al
|
|
negl %eax
|
|
orl $1, %eax
|
|
# else
|
|
movzbl (%rdi, %rcx), %eax
|
|
movzbl (%rsi, %rcx), %edx
|
|
sub %edx, %eax
|
|
# endif
|
|
VZEROUPPER
|
|
ret
|
|
|
|
# ifdef USE_AS_WMEMCMP
|
|
.p2align 4
|
|
L(4):
|
|
xorl %eax, %eax
|
|
movl (%rdi), %edx
|
|
cmpl (%rsi), %edx
|
|
jne L(wmemcmp_return)
|
|
ret
|
|
# else
|
|
.p2align 4
|
|
L(between_4_7):
|
|
/* Load as big endian with overlapping movbe to avoid branches. */
|
|
movbe (%rdi), %eax
|
|
movbe (%rsi), %ecx
|
|
shlq $32, %rax
|
|
shlq $32, %rcx
|
|
movbe -4(%rdi, %rdx), %edi
|
|
movbe -4(%rsi, %rdx), %esi
|
|
orq %rdi, %rax
|
|
orq %rsi, %rcx
|
|
subq %rcx, %rax
|
|
je L(exit)
|
|
sbbl %eax, %eax
|
|
orl $1, %eax
|
|
ret
|
|
|
|
.p2align 4
|
|
L(exit):
|
|
ret
|
|
|
|
.p2align 4
|
|
L(between_2_3):
|
|
/* Load as big endian to avoid branches. */
|
|
movzwl (%rdi), %eax
|
|
movzwl (%rsi), %ecx
|
|
shll $8, %eax
|
|
shll $8, %ecx
|
|
bswap %eax
|
|
bswap %ecx
|
|
movb -1(%rdi, %rdx), %al
|
|
movb -1(%rsi, %rdx), %cl
|
|
/* Subtraction is okay because the upper 8 bits are zero. */
|
|
subl %ecx, %eax
|
|
ret
|
|
|
|
.p2align 4
|
|
L(1):
|
|
movzbl (%rdi), %eax
|
|
movzbl (%rsi), %ecx
|
|
subl %ecx, %eax
|
|
ret
|
|
# endif
|
|
|
|
.p2align 4
|
|
L(zero):
|
|
xorl %eax, %eax
|
|
ret
|
|
|
|
.p2align 4
|
|
L(less_vec):
|
|
# ifdef USE_AS_WMEMCMP
|
|
/* It can only be 0, 4, 8, 12, 16, 20, 24, 28 bytes. */
|
|
cmpb $4, %dl
|
|
je L(4)
|
|
jb L(zero)
|
|
# else
|
|
cmpb $1, %dl
|
|
je L(1)
|
|
jb L(zero)
|
|
cmpb $4, %dl
|
|
jb L(between_2_3)
|
|
cmpb $8, %dl
|
|
jb L(between_4_7)
|
|
# endif
|
|
cmpb $16, %dl
|
|
jae L(between_16_31)
|
|
/* It is between 8 and 15 bytes. */
|
|
vmovq (%rdi), %xmm1
|
|
vmovq (%rsi), %xmm2
|
|
VPCMPEQ %xmm1, %xmm2, %xmm2
|
|
vpmovmskb %xmm2, %eax
|
|
subl $0xffff, %eax
|
|
jnz L(first_vec)
|
|
/* Use overlapping loads to avoid branches. */
|
|
leaq -8(%rdi, %rdx), %rdi
|
|
leaq -8(%rsi, %rdx), %rsi
|
|
vmovq (%rdi), %xmm1
|
|
vmovq (%rsi), %xmm2
|
|
VPCMPEQ %xmm1, %xmm2, %xmm2
|
|
vpmovmskb %xmm2, %eax
|
|
subl $0xffff, %eax
|
|
jnz L(first_vec)
|
|
ret
|
|
|
|
.p2align 4
|
|
L(between_16_31):
|
|
/* From 16 to 31 bytes. No branch when size == 16. */
|
|
vmovdqu (%rsi), %xmm2
|
|
VPCMPEQ (%rdi), %xmm2, %xmm2
|
|
vpmovmskb %xmm2, %eax
|
|
subl $0xffff, %eax
|
|
jnz L(first_vec)
|
|
|
|
/* Use overlapping loads to avoid branches. */
|
|
leaq -16(%rdi, %rdx), %rdi
|
|
leaq -16(%rsi, %rdx), %rsi
|
|
vmovdqu (%rsi), %xmm2
|
|
VPCMPEQ (%rdi), %xmm2, %xmm2
|
|
vpmovmskb %xmm2, %eax
|
|
subl $0xffff, %eax
|
|
jnz L(first_vec)
|
|
ret
|
|
|
|
.p2align 4
|
|
L(more_8x_vec):
|
|
/* More than 8 * VEC. Check the first VEC. */
|
|
vmovdqu (%rsi), %ymm2
|
|
VPCMPEQ (%rdi), %ymm2, %ymm2
|
|
vpmovmskb %ymm2, %eax
|
|
subl $VEC_MASK, %eax
|
|
jnz L(first_vec)
|
|
|
|
/* Align the first memory area for aligned loads in the loop.
|
|
Compute how much the first memory area is misaligned. */
|
|
movq %rdi, %rcx
|
|
andl $(VEC_SIZE - 1), %ecx
|
|
/* Get the negative of offset for alignment. */
|
|
subq $VEC_SIZE, %rcx
|
|
/* Adjust the second memory area. */
|
|
subq %rcx, %rsi
|
|
/* Adjust the first memory area which should be aligned now. */
|
|
subq %rcx, %rdi
|
|
/* Adjust length. */
|
|
addq %rcx, %rdx
|
|
|
|
L(loop_4x_vec):
|
|
/* Compare 4 * VEC at a time forward. */
|
|
vmovdqu (%rsi), %ymm1
|
|
VPCMPEQ (%rdi), %ymm1, %ymm1
|
|
|
|
vmovdqu VEC_SIZE(%rsi), %ymm2
|
|
VPCMPEQ VEC_SIZE(%rdi), %ymm2, %ymm2
|
|
vpand %ymm2, %ymm1, %ymm5
|
|
|
|
vmovdqu (VEC_SIZE * 2)(%rsi), %ymm3
|
|
VPCMPEQ (VEC_SIZE * 2)(%rdi), %ymm3, %ymm3
|
|
vpand %ymm3, %ymm5, %ymm5
|
|
|
|
vmovdqu (VEC_SIZE * 3)(%rsi), %ymm4
|
|
VPCMPEQ (VEC_SIZE * 3)(%rdi), %ymm4, %ymm4
|
|
vpand %ymm4, %ymm5, %ymm5
|
|
|
|
vptest %ymm0, %ymm5
|
|
jnc L(4x_vec_end)
|
|
|
|
addq $(VEC_SIZE * 4), %rdi
|
|
addq $(VEC_SIZE * 4), %rsi
|
|
|
|
subq $(VEC_SIZE * 4), %rdx
|
|
cmpq $(VEC_SIZE * 4), %rdx
|
|
jae L(loop_4x_vec)
|
|
|
|
/* Less than 4 * VEC. */
|
|
cmpq $VEC_SIZE, %rdx
|
|
jbe L(last_vec)
|
|
cmpq $(VEC_SIZE * 2), %rdx
|
|
jbe L(last_2x_vec)
|
|
|
|
L(last_4x_vec):
|
|
/* From 2 * VEC to 4 * VEC. */
|
|
vmovdqu (%rsi), %ymm2
|
|
VPCMPEQ (%rdi), %ymm2, %ymm2
|
|
vpmovmskb %ymm2, %eax
|
|
subl $VEC_MASK, %eax
|
|
jnz L(first_vec)
|
|
|
|
addq $VEC_SIZE, %rdi
|
|
addq $VEC_SIZE, %rsi
|
|
vmovdqu (%rsi), %ymm2
|
|
VPCMPEQ (%rdi), %ymm2, %ymm2
|
|
vpmovmskb %ymm2, %eax
|
|
subl $VEC_MASK, %eax
|
|
jnz L(first_vec)
|
|
|
|
/* Use overlapping loads to avoid branches. */
|
|
leaq -(3 * VEC_SIZE)(%rdi, %rdx), %rdi
|
|
leaq -(3 * VEC_SIZE)(%rsi, %rdx), %rsi
|
|
vmovdqu (%rsi), %ymm2
|
|
VPCMPEQ (%rdi), %ymm2, %ymm2
|
|
vpmovmskb %ymm2, %eax
|
|
subl $VEC_MASK, %eax
|
|
jnz L(first_vec)
|
|
|
|
addq $VEC_SIZE, %rdi
|
|
addq $VEC_SIZE, %rsi
|
|
vmovdqu (%rsi), %ymm2
|
|
VPCMPEQ (%rdi), %ymm2, %ymm2
|
|
vpmovmskb %ymm2, %eax
|
|
subl $VEC_MASK, %eax
|
|
jnz L(first_vec)
|
|
VZEROUPPER
|
|
ret
|
|
|
|
.p2align 4
|
|
L(4x_vec_end):
|
|
vpmovmskb %ymm1, %eax
|
|
subl $VEC_MASK, %eax
|
|
jnz L(first_vec)
|
|
vpmovmskb %ymm2, %eax
|
|
subl $VEC_MASK, %eax
|
|
jnz L(first_vec_x1)
|
|
vpmovmskb %ymm3, %eax
|
|
subl $VEC_MASK, %eax
|
|
jnz L(first_vec_x2)
|
|
vpmovmskb %ymm4, %eax
|
|
subl $VEC_MASK, %eax
|
|
tzcntl %eax, %ecx
|
|
# ifdef USE_AS_WMEMCMP
|
|
xorl %eax, %eax
|
|
movl (VEC_SIZE * 3)(%rdi, %rcx), %edx
|
|
cmpl (VEC_SIZE * 3)(%rsi, %rcx), %edx
|
|
jmp L(wmemcmp_return)
|
|
# else
|
|
movzbl (VEC_SIZE * 3)(%rdi, %rcx), %eax
|
|
movzbl (VEC_SIZE * 3)(%rsi, %rcx), %edx
|
|
sub %edx, %eax
|
|
# endif
|
|
VZEROUPPER
|
|
ret
|
|
|
|
.p2align 4
|
|
L(first_vec_x1):
|
|
tzcntl %eax, %ecx
|
|
# ifdef USE_AS_WMEMCMP
|
|
xorl %eax, %eax
|
|
movl VEC_SIZE(%rdi, %rcx), %edx
|
|
cmpl VEC_SIZE(%rsi, %rcx), %edx
|
|
jmp L(wmemcmp_return)
|
|
# else
|
|
movzbl VEC_SIZE(%rdi, %rcx), %eax
|
|
movzbl VEC_SIZE(%rsi, %rcx), %edx
|
|
sub %edx, %eax
|
|
# endif
|
|
VZEROUPPER
|
|
ret
|
|
|
|
.p2align 4
|
|
L(first_vec_x2):
|
|
tzcntl %eax, %ecx
|
|
# ifdef USE_AS_WMEMCMP
|
|
xorl %eax, %eax
|
|
movl (VEC_SIZE * 2)(%rdi, %rcx), %edx
|
|
cmpl (VEC_SIZE * 2)(%rsi, %rcx), %edx
|
|
jmp L(wmemcmp_return)
|
|
# else
|
|
movzbl (VEC_SIZE * 2)(%rdi, %rcx), %eax
|
|
movzbl (VEC_SIZE * 2)(%rsi, %rcx), %edx
|
|
sub %edx, %eax
|
|
# endif
|
|
VZEROUPPER
|
|
ret
|
|
END (MEMCMP)
|
|
#endif
|