mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-25 14:30:06 +00:00
dc485ceb2a
Optimize strlen/strnlen/wcslen/wcsnlen with AVX2 to check 32 bytes with a single vector compare instruction. It is as fast as SSE2 versions for size <= 16 bytes and up to 1X faster for or size > 16 bytes on Haswell. Select AVX2 version on AVX2 machines where vzeroupper is preferred and AVX unaligned load is fast. NB: It uses TZCNT instead of BSF since TZCNT produces the same result as BSF for non-zero input. TZCNT is faster than BSF and is executed as BSF if machine doesn't support TZCNT. * sysdeps/x86_64/multiarch/Makefile (sysdep_routines): Add strlen-sse2, strnlen-sse2, strlen-avx2, strnlen-avx2, wcslen-sse2, wcslen-avx2 and wcsnlen-avx2. * sysdeps/x86_64/multiarch/ifunc-impl-list.c (__libc_ifunc_impl_list): Add tests for __strlen_avx2, __strlen_sse2, __strnlen_avx2, __strnlen_sse2, __wcslen_avx2, __wcslen_sse2 and __wcsnlen_avx2. * sysdeps/x86_64/multiarch/strlen-avx2.S: New file. * sysdeps/x86_64/multiarch/strlen-sse2.S: Likewise. * sysdeps/x86_64/multiarch/strlen.c: Likewise. * sysdeps/x86_64/multiarch/strnlen-avx2.S: Likewise. * sysdeps/x86_64/multiarch/strnlen-sse2.S: Likewise. * sysdeps/x86_64/multiarch/strnlen.c: Likewise. * sysdeps/x86_64/multiarch/wcslen-avx2.S: Likewise. * sysdeps/x86_64/multiarch/wcslen-sse2.S: Likewise. * sysdeps/x86_64/multiarch/wcslen.c: Likewise. * sysdeps/x86_64/multiarch/wcsnlen-avx2.S: Likewise. * sysdeps/x86_64/multiarch/wcsnlen.c (OPTIMIZE (avx2)): New. (IFUNC_SELECTOR): Return OPTIMIZE (avx2) on AVX2 machines where vzeroupper is preferred and AVX unaligned load is fast.
395 lines
7.4 KiB
ArmAsm
395 lines
7.4 KiB
ArmAsm
/* strlen/strnlen/wcslen/wcsnlen optimized with AVX2.
|
|
Copyright (C) 2017 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)
|
|
|
|
# include <sysdep.h>
|
|
|
|
# ifndef STRLEN
|
|
# define STRLEN __strlen_avx2
|
|
# endif
|
|
|
|
# ifdef USE_AS_WCSLEN
|
|
# define VPCMPEQ vpcmpeqd
|
|
# define VPMINU vpminud
|
|
# else
|
|
# define VPCMPEQ vpcmpeqb
|
|
# define VPMINU vpminub
|
|
# endif
|
|
|
|
# ifndef VZEROUPPER
|
|
# define VZEROUPPER vzeroupper
|
|
# endif
|
|
|
|
# define VEC_SIZE 32
|
|
|
|
.section .text.avx,"ax",@progbits
|
|
ENTRY (STRLEN)
|
|
# ifdef USE_AS_STRNLEN
|
|
/* Check for zero length. */
|
|
testq %rsi, %rsi
|
|
jz L(zero)
|
|
# ifdef USE_AS_WCSLEN
|
|
shl $2, %rsi
|
|
# endif
|
|
movq %rsi, %r8
|
|
# endif
|
|
movl %edi, %ecx
|
|
movq %rdi, %rdx
|
|
vpxor %xmm0, %xmm0, %xmm0
|
|
|
|
/* Check if we may cross page boundary with one vector load. */
|
|
andl $(2 * VEC_SIZE - 1), %ecx
|
|
cmpl $VEC_SIZE, %ecx
|
|
ja L(cros_page_boundary)
|
|
|
|
/* Check the first VEC_SIZE bytes. */
|
|
VPCMPEQ (%rdi), %ymm0, %ymm1
|
|
vpmovmskb %ymm1, %eax
|
|
testl %eax, %eax
|
|
|
|
# ifdef USE_AS_STRNLEN
|
|
jnz L(first_vec_x0_check)
|
|
/* Adjust length and check the end of data. */
|
|
subq $VEC_SIZE, %rsi
|
|
jbe L(max)
|
|
# else
|
|
jnz L(first_vec_x0)
|
|
# endif
|
|
|
|
/* Align data for aligned loads in the loop. */
|
|
addq $VEC_SIZE, %rdi
|
|
andl $(VEC_SIZE - 1), %ecx
|
|
andq $-VEC_SIZE, %rdi
|
|
|
|
# ifdef USE_AS_STRNLEN
|
|
/* Adjust length. */
|
|
addq %rcx, %rsi
|
|
|
|
subq $(VEC_SIZE * 4), %rsi
|
|
jbe L(last_4x_vec_or_less)
|
|
# endif
|
|
jmp L(more_4x_vec)
|
|
|
|
.p2align 4
|
|
L(cros_page_boundary):
|
|
andl $(VEC_SIZE - 1), %ecx
|
|
andq $-VEC_SIZE, %rdi
|
|
VPCMPEQ (%rdi), %ymm0, %ymm1
|
|
vpmovmskb %ymm1, %eax
|
|
/* Remove the leading bytes. */
|
|
sarl %cl, %eax
|
|
testl %eax, %eax
|
|
jz L(aligned_more)
|
|
tzcntl %eax, %eax
|
|
# ifdef USE_AS_STRNLEN
|
|
/* Check the end of data. */
|
|
cmpq %rax, %rsi
|
|
jbe L(max)
|
|
# endif
|
|
addq %rdi, %rax
|
|
addq %rcx, %rax
|
|
subq %rdx, %rax
|
|
# ifdef USE_AS_WCSLEN
|
|
shrq $2, %rax
|
|
# endif
|
|
VZEROUPPER
|
|
ret
|
|
|
|
.p2align 4
|
|
L(aligned_more):
|
|
# ifdef USE_AS_STRNLEN
|
|
/* "rcx" is less than VEC_SIZE. Calculate "rdx + rcx - VEC_SIZE"
|
|
with "rdx - (VEC_SIZE - rcx)" instead of "(rdx + rcx) - VEC_SIZE"
|
|
to void possible addition overflow. */
|
|
negq %rcx
|
|
addq $VEC_SIZE, %rcx
|
|
|
|
/* Check the end of data. */
|
|
subq %rcx, %rsi
|
|
jbe L(max)
|
|
# endif
|
|
|
|
addq $VEC_SIZE, %rdi
|
|
|
|
# ifdef USE_AS_STRNLEN
|
|
subq $(VEC_SIZE * 4), %rsi
|
|
jbe L(last_4x_vec_or_less)
|
|
# endif
|
|
|
|
L(more_4x_vec):
|
|
/* Check the first 4 * VEC_SIZE. Only one VEC_SIZE at a time
|
|
since data is only aligned to VEC_SIZE. */
|
|
VPCMPEQ (%rdi), %ymm0, %ymm1
|
|
vpmovmskb %ymm1, %eax
|
|
testl %eax, %eax
|
|
jnz L(first_vec_x0)
|
|
|
|
VPCMPEQ VEC_SIZE(%rdi), %ymm0, %ymm1
|
|
vpmovmskb %ymm1, %eax
|
|
testl %eax, %eax
|
|
jnz L(first_vec_x1)
|
|
|
|
VPCMPEQ (VEC_SIZE * 2)(%rdi), %ymm0, %ymm1
|
|
vpmovmskb %ymm1, %eax
|
|
testl %eax, %eax
|
|
jnz L(first_vec_x2)
|
|
|
|
VPCMPEQ (VEC_SIZE * 3)(%rdi), %ymm0, %ymm1
|
|
vpmovmskb %ymm1, %eax
|
|
testl %eax, %eax
|
|
jnz L(first_vec_x3)
|
|
|
|
addq $(VEC_SIZE * 4), %rdi
|
|
|
|
# ifdef USE_AS_STRNLEN
|
|
subq $(VEC_SIZE * 4), %rsi
|
|
jbe L(last_4x_vec_or_less)
|
|
# endif
|
|
|
|
/* Align data to 4 * VEC_SIZE. */
|
|
movq %rdi, %rcx
|
|
andl $(4 * VEC_SIZE - 1), %ecx
|
|
andq $-(4 * VEC_SIZE), %rdi
|
|
|
|
# ifdef USE_AS_STRNLEN
|
|
/* Adjust length. */
|
|
addq %rcx, %rsi
|
|
# endif
|
|
|
|
.p2align 4
|
|
L(loop_4x_vec):
|
|
/* Compare 4 * VEC at a time forward. */
|
|
vmovdqa (%rdi), %ymm1
|
|
vmovdqa VEC_SIZE(%rdi), %ymm2
|
|
vmovdqa (VEC_SIZE * 2)(%rdi), %ymm3
|
|
vmovdqa (VEC_SIZE * 3)(%rdi), %ymm4
|
|
VPMINU %ymm1, %ymm2, %ymm5
|
|
VPMINU %ymm3, %ymm4, %ymm6
|
|
VPMINU %ymm5, %ymm6, %ymm5
|
|
|
|
VPCMPEQ %ymm5, %ymm0, %ymm5
|
|
vpmovmskb %ymm5, %eax
|
|
testl %eax, %eax
|
|
jnz L(4x_vec_end)
|
|
|
|
addq $(VEC_SIZE * 4), %rdi
|
|
|
|
# ifndef USE_AS_STRNLEN
|
|
jmp L(loop_4x_vec)
|
|
# else
|
|
subq $(VEC_SIZE * 4), %rsi
|
|
ja L(loop_4x_vec)
|
|
|
|
L(last_4x_vec_or_less):
|
|
/* Less than 4 * VEC and aligned to VEC_SIZE. */
|
|
addl $(VEC_SIZE * 2), %esi
|
|
jle L(last_2x_vec)
|
|
|
|
VPCMPEQ (%rdi), %ymm0, %ymm1
|
|
vpmovmskb %ymm1, %eax
|
|
testl %eax, %eax
|
|
jnz L(first_vec_x0)
|
|
|
|
VPCMPEQ VEC_SIZE(%rdi), %ymm0, %ymm1
|
|
vpmovmskb %ymm1, %eax
|
|
testl %eax, %eax
|
|
jnz L(first_vec_x1)
|
|
|
|
VPCMPEQ (VEC_SIZE * 2)(%rdi), %ymm0, %ymm1
|
|
vpmovmskb %ymm1, %eax
|
|
testl %eax, %eax
|
|
|
|
jnz L(first_vec_x2_check)
|
|
subl $VEC_SIZE, %esi
|
|
jle L(max)
|
|
|
|
VPCMPEQ (VEC_SIZE * 3)(%rdi), %ymm0, %ymm1
|
|
vpmovmskb %ymm1, %eax
|
|
testl %eax, %eax
|
|
|
|
jnz L(first_vec_x3_check)
|
|
movq %r8, %rax
|
|
# ifdef USE_AS_WCSLEN
|
|
shrq $2, %rax
|
|
# endif
|
|
VZEROUPPER
|
|
ret
|
|
|
|
.p2align 4
|
|
L(last_2x_vec):
|
|
addl $(VEC_SIZE * 2), %esi
|
|
VPCMPEQ (%rdi), %ymm0, %ymm1
|
|
vpmovmskb %ymm1, %eax
|
|
testl %eax, %eax
|
|
|
|
jnz L(first_vec_x0_check)
|
|
subl $VEC_SIZE, %esi
|
|
jle L(max)
|
|
|
|
VPCMPEQ VEC_SIZE(%rdi), %ymm0, %ymm1
|
|
vpmovmskb %ymm1, %eax
|
|
testl %eax, %eax
|
|
jnz L(first_vec_x1_check)
|
|
movq %r8, %rax
|
|
# ifdef USE_AS_WCSLEN
|
|
shrq $2, %rax
|
|
# endif
|
|
VZEROUPPER
|
|
ret
|
|
|
|
.p2align 4
|
|
L(first_vec_x0_check):
|
|
tzcntl %eax, %eax
|
|
/* Check the end of data. */
|
|
cmpq %rax, %rsi
|
|
jbe L(max)
|
|
addq %rdi, %rax
|
|
subq %rdx, %rax
|
|
# ifdef USE_AS_WCSLEN
|
|
shrq $2, %rax
|
|
# endif
|
|
VZEROUPPER
|
|
ret
|
|
|
|
.p2align 4
|
|
L(first_vec_x1_check):
|
|
tzcntl %eax, %eax
|
|
/* Check the end of data. */
|
|
cmpq %rax, %rsi
|
|
jbe L(max)
|
|
addq $VEC_SIZE, %rax
|
|
addq %rdi, %rax
|
|
subq %rdx, %rax
|
|
# ifdef USE_AS_WCSLEN
|
|
shrq $2, %rax
|
|
# endif
|
|
VZEROUPPER
|
|
ret
|
|
|
|
.p2align 4
|
|
L(first_vec_x2_check):
|
|
tzcntl %eax, %eax
|
|
/* Check the end of data. */
|
|
cmpq %rax, %rsi
|
|
jbe L(max)
|
|
addq $(VEC_SIZE * 2), %rax
|
|
addq %rdi, %rax
|
|
subq %rdx, %rax
|
|
# ifdef USE_AS_WCSLEN
|
|
shrq $2, %rax
|
|
# endif
|
|
VZEROUPPER
|
|
ret
|
|
|
|
.p2align 4
|
|
L(first_vec_x3_check):
|
|
tzcntl %eax, %eax
|
|
/* Check the end of data. */
|
|
cmpq %rax, %rsi
|
|
jbe L(max)
|
|
addq $(VEC_SIZE * 3), %rax
|
|
addq %rdi, %rax
|
|
subq %rdx, %rax
|
|
# ifdef USE_AS_WCSLEN
|
|
shrq $2, %rax
|
|
# endif
|
|
VZEROUPPER
|
|
ret
|
|
|
|
.p2align 4
|
|
L(max):
|
|
movq %r8, %rax
|
|
# ifdef USE_AS_WCSLEN
|
|
shrq $2, %rax
|
|
# endif
|
|
VZEROUPPER
|
|
ret
|
|
|
|
.p2align 4
|
|
L(zero):
|
|
xorl %eax, %eax
|
|
ret
|
|
# endif
|
|
|
|
.p2align 4
|
|
L(first_vec_x0):
|
|
tzcntl %eax, %eax
|
|
addq %rdi, %rax
|
|
subq %rdx, %rax
|
|
# ifdef USE_AS_WCSLEN
|
|
shrq $2, %rax
|
|
# endif
|
|
VZEROUPPER
|
|
ret
|
|
|
|
.p2align 4
|
|
L(first_vec_x1):
|
|
tzcntl %eax, %eax
|
|
addq $VEC_SIZE, %rax
|
|
addq %rdi, %rax
|
|
subq %rdx, %rax
|
|
# ifdef USE_AS_WCSLEN
|
|
shrq $2, %rax
|
|
# endif
|
|
VZEROUPPER
|
|
ret
|
|
|
|
.p2align 4
|
|
L(first_vec_x2):
|
|
tzcntl %eax, %eax
|
|
addq $(VEC_SIZE * 2), %rax
|
|
addq %rdi, %rax
|
|
subq %rdx, %rax
|
|
# ifdef USE_AS_WCSLEN
|
|
shrq $2, %rax
|
|
# endif
|
|
VZEROUPPER
|
|
ret
|
|
|
|
.p2align 4
|
|
L(4x_vec_end):
|
|
VPCMPEQ %ymm1, %ymm0, %ymm1
|
|
vpmovmskb %ymm1, %eax
|
|
testl %eax, %eax
|
|
jnz L(first_vec_x0)
|
|
VPCMPEQ %ymm2, %ymm0, %ymm2
|
|
vpmovmskb %ymm2, %eax
|
|
testl %eax, %eax
|
|
jnz L(first_vec_x1)
|
|
VPCMPEQ %ymm3, %ymm0, %ymm3
|
|
vpmovmskb %ymm3, %eax
|
|
testl %eax, %eax
|
|
jnz L(first_vec_x2)
|
|
VPCMPEQ %ymm4, %ymm0, %ymm4
|
|
vpmovmskb %ymm4, %eax
|
|
testl %eax, %eax
|
|
L(first_vec_x3):
|
|
tzcntl %eax, %eax
|
|
addq $(VEC_SIZE * 3), %rax
|
|
addq %rdi, %rax
|
|
subq %rdx, %rax
|
|
# ifdef USE_AS_WCSLEN
|
|
shrq $2, %rax
|
|
# endif
|
|
VZEROUPPER
|
|
ret
|
|
|
|
END (STRLEN)
|
|
#endif
|