mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-23 09:43:32 +08:00
x86: Optimize strlen-avx2.S
No bug. This commit optimizes strlen-avx2.S. The optimizations are mostly small things but they add up to roughly 10-30% performance improvement for strlen. The results for strnlen are bit more ambiguous. test-strlen, test-strnlen, test-wcslen, and test-wcsnlen are all passing. Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com>
This commit is contained in:
Noah Goldstein
H.J. Lu
parent
4ba6558684
commit
aaa23c3507
@ -293,10 +293,12 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
|
||||
/* Support sysdeps/x86_64/multiarch/strlen.c. */
|
||||
IFUNC_IMPL (i, name, strlen,
|
||||
IFUNC_IMPL_ADD (array, i, strlen,
|
||||
CPU_FEATURE_USABLE (AVX2),
|
||||
(CPU_FEATURE_USABLE (AVX2)
|
||||
&& CPU_FEATURE_USABLE (BMI2)),
|
||||
__strlen_avx2)
|
||||
IFUNC_IMPL_ADD (array, i, strlen,
|
||||
(CPU_FEATURE_USABLE (AVX2)
|
||||
&& CPU_FEATURE_USABLE (BMI2)
|
||||
&& CPU_FEATURE_USABLE (RTM)),
|
||||
__strlen_avx2_rtm)
|
||||
IFUNC_IMPL_ADD (array, i, strlen,
|
||||
@ -309,10 +311,12 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
|
||||
/* Support sysdeps/x86_64/multiarch/strnlen.c. */
|
||||
IFUNC_IMPL (i, name, strnlen,
|
||||
IFUNC_IMPL_ADD (array, i, strnlen,
|
||||
CPU_FEATURE_USABLE (AVX2),
|
||||
(CPU_FEATURE_USABLE (AVX2)
|
||||
&& CPU_FEATURE_USABLE (BMI2)),
|
||||
__strnlen_avx2)
|
||||
IFUNC_IMPL_ADD (array, i, strnlen,
|
||||
(CPU_FEATURE_USABLE (AVX2)
|
||||
&& CPU_FEATURE_USABLE (BMI2)
|
||||
&& CPU_FEATURE_USABLE (RTM)),
|
||||
__strnlen_avx2_rtm)
|
||||
IFUNC_IMPL_ADD (array, i, strnlen,
|
||||
@ -654,10 +658,12 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
|
||||
/* Support sysdeps/x86_64/multiarch/wcslen.c. */
|
||||
IFUNC_IMPL (i, name, wcslen,
|
||||
IFUNC_IMPL_ADD (array, i, wcslen,
|
||||
CPU_FEATURE_USABLE (AVX2),
|
||||
(CPU_FEATURE_USABLE (AVX2)
|
||||
&& CPU_FEATURE_USABLE (BMI2)),
|
||||
__wcslen_avx2)
|
||||
IFUNC_IMPL_ADD (array, i, wcslen,
|
||||
(CPU_FEATURE_USABLE (AVX2)
|
||||
&& CPU_FEATURE_USABLE (BMI2)
|
||||
&& CPU_FEATURE_USABLE (RTM)),
|
||||
__wcslen_avx2_rtm)
|
||||
IFUNC_IMPL_ADD (array, i, wcslen,
|
||||
@ -670,10 +676,12 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
|
||||
/* Support sysdeps/x86_64/multiarch/wcsnlen.c. */
|
||||
IFUNC_IMPL (i, name, wcsnlen,
|
||||
IFUNC_IMPL_ADD (array, i, wcsnlen,
|
||||
CPU_FEATURE_USABLE (AVX2),
|
||||
(CPU_FEATURE_USABLE (AVX2)
|
||||
&& CPU_FEATURE_USABLE (BMI2)),
|
||||
__wcsnlen_avx2)
|
||||
IFUNC_IMPL_ADD (array, i, wcsnlen,
|
||||
(CPU_FEATURE_USABLE (AVX2)
|
||||
&& CPU_FEATURE_USABLE (BMI2)
|
||||
&& CPU_FEATURE_USABLE (RTM)),
|
||||
__wcsnlen_avx2_rtm)
|
||||
IFUNC_IMPL_ADD (array, i, wcsnlen,
|
||||
|
||||
@ -27,9 +27,11 @@
|
||||
# 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
|
||||
@ -41,349 +43,459 @@
|
||||
# endif
|
||||
|
||||
# define VEC_SIZE 32
|
||||
# define PAGE_SIZE 4096
|
||||
|
||||
.section SECTION(.text),"ax",@progbits
|
||||
ENTRY (STRLEN)
|
||||
# ifdef USE_AS_STRNLEN
|
||||
/* Check for zero length. */
|
||||
/* Check zero length. */
|
||||
test %RSI_LP, %RSI_LP
|
||||
jz L(zero)
|
||||
/* Store max len in R8_LP before adjusting if using WCSLEN. */
|
||||
mov %RSI_LP, %R8_LP
|
||||
# ifdef USE_AS_WCSLEN
|
||||
shl $2, %RSI_LP
|
||||
# elif defined __ILP32__
|
||||
/* Clear the upper 32 bits. */
|
||||
movl %esi, %esi
|
||||
# endif
|
||||
mov %RSI_LP, %R8_LP
|
||||
# endif
|
||||
movl %edi, %ecx
|
||||
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. */
|
||||
andl $(2 * VEC_SIZE - 1), %ecx
|
||||
cmpl $VEC_SIZE, %ecx
|
||||
ja L(cros_page_boundary)
|
||||
cmpl $(PAGE_SIZE - VEC_SIZE), %eax
|
||||
ja L(cross_page_boundary)
|
||||
|
||||
/* Check the first VEC_SIZE bytes. */
|
||||
VPCMPEQ (%rdi), %ymm0, %ymm1
|
||||
vpmovmskb %ymm1, %eax
|
||||
testl %eax, %eax
|
||||
|
||||
VPCMPEQ (%rdi), %ymm0, %ymm1
|
||||
vpmovmskb %ymm1, %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)
|
||||
/* If length < VEC_SIZE handle special. */
|
||||
cmpq $VEC_SIZE, %rsi
|
||||
jbe 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
|
||||
/* 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_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
|
||||
shrl $2, %eax
|
||||
# endif
|
||||
L(return_vzeroupper):
|
||||
ZERO_UPPER_VEC_REGISTERS_RETURN
|
||||
|
||||
.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
|
||||
VZEROUPPER_RETURN
|
||||
|
||||
# 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_RETURN
|
||||
|
||||
.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_RETURN
|
||||
|
||||
.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_RETURN
|
||||
|
||||
.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_RETURN
|
||||
|
||||
.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_RETURN
|
||||
|
||||
.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_RETURN
|
||||
|
||||
.p2align 4
|
||||
L(max):
|
||||
movq %r8, %rax
|
||||
# ifdef USE_AS_WCSLEN
|
||||
shrq $2, %rax
|
||||
# endif
|
||||
VZEROUPPER_RETURN
|
||||
|
||||
.p2align 4
|
||||
L(zero):
|
||||
xorl %eax, %eax
|
||||
ret
|
||||
# endif
|
||||
|
||||
.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. */
|
||||
btsq %rsi, %rax
|
||||
tzcntl %eax, %eax
|
||||
addq %rdi, %rax
|
||||
subq %rdx, %rax
|
||||
# ifdef USE_AS_WCSLEN
|
||||
shrq $2, %rax
|
||||
# endif
|
||||
# ifdef USE_AS_WCSLEN
|
||||
shrl $2, %eax
|
||||
# endif
|
||||
VZEROUPPER_RETURN
|
||||
# endif
|
||||
|
||||
.p2align 4
|
||||
L(first_vec_x1):
|
||||
tzcntl %eax, %eax
|
||||
addq $VEC_SIZE, %rax
|
||||
addq %rdi, %rax
|
||||
subq %rdx, %rax
|
||||
/* 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.
|
||||
*/
|
||||
subl $(VEC_SIZE * 4 + 1), %ecx
|
||||
addl %ecx, %eax
|
||||
# else
|
||||
subl %edx, %edi
|
||||
incl %edi
|
||||
addl %edi, %eax
|
||||
# endif
|
||||
# ifdef USE_AS_WCSLEN
|
||||
shrq $2, %rax
|
||||
shrl $2, %eax
|
||||
# endif
|
||||
VZEROUPPER_RETURN
|
||||
|
||||
.p2align 4
|
||||
L(first_vec_x2):
|
||||
tzcntl %eax, %eax
|
||||
addq $(VEC_SIZE * 2), %rax
|
||||
/* 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.
|
||||
*/
|
||||
subl $(VEC_SIZE * 3 + 1), %ecx
|
||||
addl %ecx, %eax
|
||||
# else
|
||||
subl %edx, %edi
|
||||
addl $(VEC_SIZE + 1), %edi
|
||||
addl %edi, %eax
|
||||
# endif
|
||||
# ifdef USE_AS_WCSLEN
|
||||
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.
|
||||
*/
|
||||
subl $(VEC_SIZE * 2 + 1), %ecx
|
||||
addl %ecx, %eax
|
||||
# else
|
||||
subl %edx, %edi
|
||||
addl $(VEC_SIZE * 2 + 1), %edi
|
||||
addl %edi, %eax
|
||||
# endif
|
||||
# ifdef USE_AS_WCSLEN
|
||||
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.
|
||||
*/
|
||||
subl $(VEC_SIZE + 1), %ecx
|
||||
addl %ecx, %eax
|
||||
# else
|
||||
subl %edx, %edi
|
||||
addl $(VEC_SIZE * 3 + 1), %edi
|
||||
addl %edi, %eax
|
||||
# endif
|
||||
# ifdef USE_AS_WCSLEN
|
||||
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
|
||||
# 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 $(VEC_SIZE * 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
|
||||
/* 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 $(VEC_SIZE * 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
|
||||
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):
|
||||
|
||||
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
|
||||
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
|
||||
subq %rdx, %rax
|
||||
# ifdef USE_AS_WCSLEN
|
||||
shrq $2, %rax
|
||||
# endif
|
||||
VZEROUPPER_RETURN
|
||||
|
||||
.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
|
||||
L(first_vec_x3):
|
||||
L(last_vec_return_x1):
|
||||
tzcntl %eax, %eax
|
||||
addq $(VEC_SIZE * 3), %rax
|
||||
subq $(VEC_SIZE * 3 - 1), %rdi
|
||||
addq %rdi, %rax
|
||||
subq %rdx, %rax
|
||||
# ifdef USE_AS_WCSLEN
|
||||
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
|
||||
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
|
||||
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
|
||||
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
|
||||
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
|
||||
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
|
||||
/* 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
|
||||
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
|
||||
cmpq %rax, %rsi
|
||||
cmovb %esi, %eax
|
||||
# ifdef USE_AS_WCSLEN
|
||||
shrl $2, %eax
|
||||
# endif
|
||||
VZEROUPPER_RETURN
|
||||
# endif
|
||||
|
||||
END (STRLEN)
|
||||
#endif
|
||||
|
||||
Loading…
Reference in New Issue
Block a user