mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-26 04:31:03 +00:00
x86: Optimize strlen-evex.S
No bug. This commit optimizes strlen-evex.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
b1e5572837
commit
4ba6558684
@ -29,11 +29,13 @@
|
||||
# ifdef USE_AS_WCSLEN
|
||||
# define VPCMP vpcmpd
|
||||
# define VPMINU vpminud
|
||||
# define SHIFT_REG r9d
|
||||
# define SHIFT_REG ecx
|
||||
# define CHAR_SIZE 4
|
||||
# else
|
||||
# define VPCMP vpcmpb
|
||||
# define VPMINU vpminub
|
||||
# define SHIFT_REG ecx
|
||||
# define SHIFT_REG edx
|
||||
# define CHAR_SIZE 1
|
||||
# endif
|
||||
|
||||
# define XMMZERO xmm16
|
||||
@ -46,132 +48,165 @@
|
||||
# define YMM6 ymm22
|
||||
|
||||
# define VEC_SIZE 32
|
||||
# define PAGE_SIZE 4096
|
||||
# define CHAR_PER_VEC (VEC_SIZE / CHAR_SIZE)
|
||||
|
||||
.section .text.evex,"ax",@progbits
|
||||
ENTRY (STRLEN)
|
||||
# ifdef USE_AS_STRNLEN
|
||||
/* Check for zero length. */
|
||||
/* Check zero length. */
|
||||
test %RSI_LP, %RSI_LP
|
||||
jz L(zero)
|
||||
# ifdef USE_AS_WCSLEN
|
||||
shl $2, %RSI_LP
|
||||
# elif defined __ILP32__
|
||||
# ifdef __ILP32__
|
||||
/* Clear the upper 32 bits. */
|
||||
movl %esi, %esi
|
||||
# endif
|
||||
mov %RSI_LP, %R8_LP
|
||||
# endif
|
||||
movl %edi, %ecx
|
||||
movq %rdi, %rdx
|
||||
movl %edi, %eax
|
||||
vpxorq %XMMZERO, %XMMZERO, %XMMZERO
|
||||
|
||||
/* 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. Each bit in K0 represents a
|
||||
null byte. */
|
||||
VPCMP $0, (%rdi), %YMMZERO, %k0
|
||||
kmovd %k0, %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)
|
||||
/* If length < CHAR_PER_VEC handle special. */
|
||||
cmpq $CHAR_PER_VEC, %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
|
||||
|
||||
# ifdef USE_AS_WCSLEN
|
||||
/* NB: Divide shift count by 4 since each bit in K0 represent 4
|
||||
bytes. */
|
||||
movl %ecx, %SHIFT_REG
|
||||
sarl $2, %SHIFT_REG
|
||||
# endif
|
||||
VPCMP $0, (%rdi), %YMMZERO, %k0
|
||||
kmovd %k0, %eax
|
||||
|
||||
/* Remove the leading bytes. */
|
||||
sarxl %SHIFT_REG, %eax, %eax
|
||||
testl %eax, %eax
|
||||
jz L(aligned_more)
|
||||
tzcntl %eax, %eax
|
||||
# ifdef USE_AS_WCSLEN
|
||||
/* NB: Multiply wchar_t count by 4 to get the number of bytes. */
|
||||
sall $2, %eax
|
||||
# endif
|
||||
ret
|
||||
# ifdef USE_AS_STRNLEN
|
||||
/* Check the end of data. */
|
||||
cmpq %rax, %rsi
|
||||
jbe L(max)
|
||||
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. */
|
||||
btsq %rsi, %rax
|
||||
tzcntl %eax, %eax
|
||||
ret
|
||||
# endif
|
||||
addq %rdi, %rax
|
||||
addq %rcx, %rax
|
||||
subq %rdx, %rax
|
||||
# ifdef USE_AS_WCSLEN
|
||||
shrq $2, %rax
|
||||
|
||||
.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.
|
||||
*/
|
||||
leal -(CHAR_PER_VEC * 4 + 1)(%rcx, %rax), %eax
|
||||
# else
|
||||
subl %edx, %edi
|
||||
# ifdef USE_AS_WCSLEN
|
||||
/* NB: Divide bytes by 4 to get the wchar_t count. */
|
||||
sarl $2, %edi
|
||||
# endif
|
||||
leal CHAR_PER_VEC(%rdi, %rax), %eax
|
||||
# endif
|
||||
ret
|
||||
|
||||
.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.
|
||||
*/
|
||||
leal -(CHAR_PER_VEC * 3 + 1)(%rcx, %rax), %eax
|
||||
# else
|
||||
subl %edx, %edi
|
||||
# ifdef USE_AS_WCSLEN
|
||||
/* NB: Divide bytes by 4 to get the wchar_t count. */
|
||||
sarl $2, %edi
|
||||
# endif
|
||||
leal (CHAR_PER_VEC * 2)(%rdi, %rax), %eax
|
||||
# endif
|
||||
ret
|
||||
|
||||
.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.
|
||||
*/
|
||||
leal -(CHAR_PER_VEC * 2 + 1)(%rcx, %rax), %eax
|
||||
# else
|
||||
subl %edx, %edi
|
||||
# ifdef USE_AS_WCSLEN
|
||||
/* NB: Divide bytes by 4 to get the wchar_t count. */
|
||||
sarl $2, %edi
|
||||
# endif
|
||||
leal (CHAR_PER_VEC * 3)(%rdi, %rax), %eax
|
||||
# endif
|
||||
ret
|
||||
|
||||
.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.
|
||||
*/
|
||||
leal -(CHAR_PER_VEC + 1)(%rcx, %rax), %eax
|
||||
# else
|
||||
subl %edx, %edi
|
||||
# ifdef USE_AS_WCSLEN
|
||||
/* NB: Divide bytes by 4 to get the wchar_t count. */
|
||||
sarl $2, %edi
|
||||
# endif
|
||||
leal (CHAR_PER_VEC * 4)(%rdi, %rax), %eax
|
||||
# endif
|
||||
ret
|
||||
|
||||
.p2align 5
|
||||
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):
|
||||
movq %rdi, %rdx
|
||||
/* Align data to VEC_SIZE. */
|
||||
andq $-(VEC_SIZE), %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. */
|
||||
VPCMP $0, (%rdi), %YMMZERO, %k0
|
||||
kmovd %k0, %eax
|
||||
testl %eax, %eax
|
||||
jnz L(first_vec_x0)
|
||||
|
||||
# ifdef USE_AS_STRNLEN
|
||||
/* + CHAR_SIZE because it simplies the logic in
|
||||
last_4x_vec_or_less. */
|
||||
leaq (VEC_SIZE * 5 + CHAR_SIZE)(%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. */
|
||||
VPCMP $0, VEC_SIZE(%rdi), %YMMZERO, %k0
|
||||
# ifdef USE_AS_STRNLEN
|
||||
/* Adjust length. If near end handle specially. */
|
||||
subq %rcx, %rsi
|
||||
jb L(last_4x_vec_or_less)
|
||||
# endif
|
||||
kmovd %k0, %eax
|
||||
testl %eax, %eax
|
||||
jnz L(first_vec_x1)
|
||||
|
||||
VPCMP $0, (VEC_SIZE * 2)(%rdi), %YMMZERO, %k0
|
||||
kmovd %k0, %eax
|
||||
testl %eax, %eax
|
||||
test %eax, %eax
|
||||
jnz L(first_vec_x2)
|
||||
|
||||
VPCMP $0, (VEC_SIZE * 3)(%rdi), %YMMZERO, %k0
|
||||
@ -179,258 +214,276 @@ L(more_4x_vec):
|
||||
testl %eax, %eax
|
||||
jnz L(first_vec_x3)
|
||||
|
||||
addq $(VEC_SIZE * 4), %rdi
|
||||
VPCMP $0, (VEC_SIZE * 4)(%rdi), %YMMZERO, %k0
|
||||
kmovd %k0, %eax
|
||||
testl %eax, %eax
|
||||
jnz L(first_vec_x4)
|
||||
|
||||
addq $VEC_SIZE, %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. */
|
||||
/* Check if at last VEC_SIZE * 4 length. */
|
||||
cmpq $(CHAR_PER_VEC * 4 - 1), %rsi
|
||||
jbe L(last_4x_vec_or_less_load)
|
||||
movl %edi, %ecx
|
||||
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
|
||||
# endif
|
||||
/* Align data to VEC_SIZE * 4. */
|
||||
andq $-(VEC_SIZE * 4), %rdi
|
||||
|
||||
/* Compare 4 * VEC at a time forward. */
|
||||
.p2align 4
|
||||
L(loop_4x_vec):
|
||||
/* Compare 4 * VEC at a time forward. */
|
||||
VMOVA (%rdi), %YMM1
|
||||
VMOVA VEC_SIZE(%rdi), %YMM2
|
||||
VMOVA (VEC_SIZE * 2)(%rdi), %YMM3
|
||||
VMOVA (VEC_SIZE * 3)(%rdi), %YMM4
|
||||
/* Load first VEC regardless. */
|
||||
VMOVA (VEC_SIZE * 4)(%rdi), %YMM1
|
||||
# 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.
|
||||
*/
|
||||
VPMINU (VEC_SIZE * 5)(%rdi), %YMM1, %YMM2
|
||||
VMOVA (VEC_SIZE * 6)(%rdi), %YMM3
|
||||
VPMINU (VEC_SIZE * 7)(%rdi), %YMM3, %YMM4
|
||||
|
||||
VPMINU %YMM1, %YMM2, %YMM5
|
||||
VPMINU %YMM3, %YMM4, %YMM6
|
||||
VPCMP $0, %YMM2, %YMMZERO, %k0
|
||||
VPCMP $0, %YMM4, %YMMZERO, %k1
|
||||
subq $-(VEC_SIZE * 4), %rdi
|
||||
kortestd %k0, %k1
|
||||
jz L(loop_4x_vec)
|
||||
|
||||
VPMINU %YMM5, %YMM6, %YMM5
|
||||
VPCMP $0, %YMM5, %YMMZERO, %k0
|
||||
ktestd %k0, %k0
|
||||
jnz L(4x_vec_end)
|
||||
/* Check if end was in first half. */
|
||||
kmovd %k0, %eax
|
||||
subq %rdx, %rdi
|
||||
# ifdef USE_AS_WCSLEN
|
||||
shrq $2, %rdi
|
||||
# endif
|
||||
testl %eax, %eax
|
||||
jz L(second_vec_return)
|
||||
|
||||
addq $(VEC_SIZE * 4), %rdi
|
||||
|
||||
# ifndef USE_AS_STRNLEN
|
||||
jmp L(loop_4x_vec)
|
||||
VPCMP $0, %YMM1, %YMMZERO, %k2
|
||||
kmovd %k2, %edx
|
||||
/* Combine VEC1 matches (edx) with VEC2 matches (eax). */
|
||||
# ifdef USE_AS_WCSLEN
|
||||
sall $CHAR_PER_VEC, %eax
|
||||
orl %edx, %eax
|
||||
tzcntl %eax, %eax
|
||||
# else
|
||||
subq $(VEC_SIZE * 4), %rsi
|
||||
ja L(loop_4x_vec)
|
||||
salq $CHAR_PER_VEC, %rax
|
||||
orq %rdx, %rax
|
||||
tzcntq %rax, %rax
|
||||
# endif
|
||||
addq %rdi, %rax
|
||||
ret
|
||||
|
||||
|
||||
# ifdef USE_AS_STRNLEN
|
||||
|
||||
L(last_4x_vec_or_less_load):
|
||||
/* Depending on entry adjust rdi / prepare first VEC in YMM1. */
|
||||
VMOVA (VEC_SIZE * 4)(%rdi), %YMM1
|
||||
L(last_4x_vec_or_less_cmpeq):
|
||||
VPCMP $0, %YMM1, %YMMZERO, %k0
|
||||
addq $(VEC_SIZE * 3), %rdi
|
||||
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)
|
||||
|
||||
VPCMP $0, (%rdi), %YMMZERO, %k0
|
||||
kmovd %k0, %eax
|
||||
testl %eax, %eax
|
||||
jnz L(first_vec_x0)
|
||||
/* If remaining length > VEC_SIZE * 2. This works if esi is off by
|
||||
VEC_SIZE * 4. */
|
||||
testl $(CHAR_PER_VEC * 2), %esi
|
||||
jnz L(last_4x_vec)
|
||||
|
||||
VPCMP $0, VEC_SIZE(%rdi), %YMMZERO, %k0
|
||||
kmovd %k0, %eax
|
||||
/* length may have been negative or positive by an offset of
|
||||
CHAR_PER_VEC * 4 depending on where this was called from. This
|
||||
fixes that. */
|
||||
andl $(CHAR_PER_VEC * 4 - 1), %esi
|
||||
testl %eax, %eax
|
||||
jnz L(first_vec_x1)
|
||||
jnz L(last_vec_x1_check)
|
||||
|
||||
/* Check the end of data. */
|
||||
subl $CHAR_PER_VEC, %esi
|
||||
jb L(max)
|
||||
|
||||
VPCMP $0, (VEC_SIZE * 2)(%rdi), %YMMZERO, %k0
|
||||
kmovd %k0, %eax
|
||||
tzcntl %eax, %eax
|
||||
/* Check the end of data. */
|
||||
cmpl %eax, %esi
|
||||
jb L(max)
|
||||
|
||||
subq %rdx, %rdi
|
||||
# ifdef USE_AS_WCSLEN
|
||||
/* NB: Divide bytes by 4 to get the wchar_t count. */
|
||||
sarq $2, %rdi
|
||||
# endif
|
||||
leaq (CHAR_PER_VEC * 2)(%rdi, %rax), %rax
|
||||
ret
|
||||
L(max):
|
||||
movq %r8, %rax
|
||||
ret
|
||||
# endif
|
||||
|
||||
/* Placed here in strnlen so that the jcc L(last_4x_vec_or_less)
|
||||
in the 4x VEC loop can use 2 byte encoding. */
|
||||
.p2align 4
|
||||
L(second_vec_return):
|
||||
VPCMP $0, %YMM3, %YMMZERO, %k0
|
||||
/* Combine YMM3 matches (k0) with YMM4 matches (k1). */
|
||||
# ifdef USE_AS_WCSLEN
|
||||
kunpckbw %k0, %k1, %k0
|
||||
kmovd %k0, %eax
|
||||
tzcntl %eax, %eax
|
||||
# else
|
||||
kunpckdq %k0, %k1, %k0
|
||||
kmovq %k0, %rax
|
||||
tzcntq %rax, %rax
|
||||
# endif
|
||||
leaq (CHAR_PER_VEC * 2)(%rdi, %rax), %rax
|
||||
ret
|
||||
|
||||
|
||||
# ifdef USE_AS_STRNLEN
|
||||
L(last_vec_x1_check):
|
||||
tzcntl %eax, %eax
|
||||
/* Check the end of data. */
|
||||
cmpl %eax, %esi
|
||||
jb L(max)
|
||||
subq %rdx, %rdi
|
||||
# ifdef USE_AS_WCSLEN
|
||||
/* NB: Divide bytes by 4 to get the wchar_t count. */
|
||||
sarq $2, %rdi
|
||||
# endif
|
||||
leaq (CHAR_PER_VEC)(%rdi, %rax), %rax
|
||||
ret
|
||||
|
||||
.p2align 4
|
||||
L(last_4x_vec):
|
||||
/* Test first 2x VEC normally. */
|
||||
testl %eax, %eax
|
||||
jnz L(last_vec_x1)
|
||||
|
||||
VPCMP $0, (VEC_SIZE * 2)(%rdi), %YMMZERO, %k0
|
||||
kmovd %k0, %eax
|
||||
testl %eax, %eax
|
||||
jnz L(first_vec_x2_check)
|
||||
subl $VEC_SIZE, %esi
|
||||
jle L(max)
|
||||
jnz L(last_vec_x2)
|
||||
|
||||
/* Normalize length. */
|
||||
andl $(CHAR_PER_VEC * 4 - 1), %esi
|
||||
VPCMP $0, (VEC_SIZE * 3)(%rdi), %YMMZERO, %k0
|
||||
kmovd %k0, %eax
|
||||
testl %eax, %eax
|
||||
jnz L(first_vec_x3_check)
|
||||
movq %r8, %rax
|
||||
jnz L(last_vec_x3)
|
||||
|
||||
/* Check the end of data. */
|
||||
subl $(CHAR_PER_VEC * 3), %esi
|
||||
jb L(max)
|
||||
|
||||
VPCMP $0, (VEC_SIZE * 4)(%rdi), %YMMZERO, %k0
|
||||
kmovd %k0, %eax
|
||||
tzcntl %eax, %eax
|
||||
/* Check the end of data. */
|
||||
cmpl %eax, %esi
|
||||
jb L(max_end)
|
||||
|
||||
subq %rdx, %rdi
|
||||
# ifdef USE_AS_WCSLEN
|
||||
shrq $2, %rax
|
||||
/* NB: Divide bytes by 4 to get the wchar_t count. */
|
||||
sarq $2, %rdi
|
||||
# endif
|
||||
leaq (CHAR_PER_VEC * 4)(%rdi, %rax), %rax
|
||||
ret
|
||||
|
||||
.p2align 4
|
||||
L(last_2x_vec):
|
||||
addl $(VEC_SIZE * 2), %esi
|
||||
L(last_vec_x1):
|
||||
tzcntl %eax, %eax
|
||||
subq %rdx, %rdi
|
||||
# ifdef USE_AS_WCSLEN
|
||||
/* NB: Divide bytes by 4 to get the wchar_t count. */
|
||||
sarq $2, %rdi
|
||||
# endif
|
||||
leaq (CHAR_PER_VEC)(%rdi, %rax), %rax
|
||||
ret
|
||||
|
||||
.p2align 4
|
||||
L(last_vec_x2):
|
||||
tzcntl %eax, %eax
|
||||
subq %rdx, %rdi
|
||||
# ifdef USE_AS_WCSLEN
|
||||
/* NB: Divide bytes by 4 to get the wchar_t count. */
|
||||
sarq $2, %rdi
|
||||
# endif
|
||||
leaq (CHAR_PER_VEC * 2)(%rdi, %rax), %rax
|
||||
ret
|
||||
|
||||
.p2align 4
|
||||
L(last_vec_x3):
|
||||
tzcntl %eax, %eax
|
||||
subl $(CHAR_PER_VEC * 2), %esi
|
||||
/* Check the end of data. */
|
||||
cmpl %eax, %esi
|
||||
jb L(max_end)
|
||||
subq %rdx, %rdi
|
||||
# ifdef USE_AS_WCSLEN
|
||||
/* NB: Divide bytes by 4 to get the wchar_t count. */
|
||||
sarq $2, %rdi
|
||||
# endif
|
||||
leaq (CHAR_PER_VEC * 3)(%rdi, %rax), %rax
|
||||
ret
|
||||
L(max_end):
|
||||
movq %r8, %rax
|
||||
ret
|
||||
# endif
|
||||
|
||||
/* Cold case for crossing page with first load. */
|
||||
.p2align 4
|
||||
L(cross_page_boundary):
|
||||
movq %rdi, %rdx
|
||||
/* Align data to VEC_SIZE. */
|
||||
andq $-VEC_SIZE, %rdi
|
||||
VPCMP $0, (%rdi), %YMMZERO, %k0
|
||||
kmovd %k0, %eax
|
||||
/* Remove the leading bytes. */
|
||||
# ifdef USE_AS_WCSLEN
|
||||
/* NB: Divide shift count by 4 since each bit in K0 represent 4
|
||||
bytes. */
|
||||
movl %edx, %ecx
|
||||
shrl $2, %ecx
|
||||
andl $(CHAR_PER_VEC - 1), %ecx
|
||||
# endif
|
||||
/* SHIFT_REG is ecx for USE_AS_WCSLEN and edx otherwise. */
|
||||
sarxl %SHIFT_REG, %eax, %eax
|
||||
testl %eax, %eax
|
||||
jnz L(first_vec_x0_check)
|
||||
subl $VEC_SIZE, %esi
|
||||
jle L(max)
|
||||
|
||||
VPCMP $0, VEC_SIZE(%rdi), %YMMZERO, %k0
|
||||
kmovd %k0, %eax
|
||||
testl %eax, %eax
|
||||
jnz L(first_vec_x1_check)
|
||||
movq %r8, %rax
|
||||
# ifdef USE_AS_WCSLEN
|
||||
shrq $2, %rax
|
||||
# endif
|
||||
ret
|
||||
|
||||
.p2align 4
|
||||
L(first_vec_x0_check):
|
||||
# ifndef USE_AS_STRNLEN
|
||||
jz L(cross_page_continue)
|
||||
tzcntl %eax, %eax
|
||||
# ifdef USE_AS_WCSLEN
|
||||
/* NB: Multiply wchar_t count by 4 to get the number of bytes. */
|
||||
sall $2, %eax
|
||||
ret
|
||||
# else
|
||||
jnz L(cross_page_less_vec)
|
||||
# ifndef USE_AS_WCSLEN
|
||||
movl %edx, %ecx
|
||||
andl $(CHAR_PER_VEC - 1), %ecx
|
||||
# endif
|
||||
movl $CHAR_PER_VEC, %eax
|
||||
subl %ecx, %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
|
||||
ja L(cross_page_continue)
|
||||
movl %esi, %eax
|
||||
ret
|
||||
|
||||
.p2align 4
|
||||
L(first_vec_x1_check):
|
||||
L(cross_page_less_vec):
|
||||
tzcntl %eax, %eax
|
||||
# ifdef USE_AS_WCSLEN
|
||||
/* NB: Multiply wchar_t count by 4 to get the number of bytes. */
|
||||
sall $2, %eax
|
||||
# endif
|
||||
/* Check the end of data. */
|
||||
/* Select min of length and position of first null. */
|
||||
cmpq %rax, %rsi
|
||||
jbe L(max)
|
||||
addq $VEC_SIZE, %rax
|
||||
addq %rdi, %rax
|
||||
subq %rdx, %rax
|
||||
# ifdef USE_AS_WCSLEN
|
||||
shrq $2, %rax
|
||||
# endif
|
||||
ret
|
||||
|
||||
.p2align 4
|
||||
L(first_vec_x2_check):
|
||||
tzcntl %eax, %eax
|
||||
# ifdef USE_AS_WCSLEN
|
||||
/* NB: Multiply wchar_t count by 4 to get the number of bytes. */
|
||||
sall $2, %eax
|
||||
# endif
|
||||
/* 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
|
||||
ret
|
||||
|
||||
.p2align 4
|
||||
L(first_vec_x3_check):
|
||||
tzcntl %eax, %eax
|
||||
# ifdef USE_AS_WCSLEN
|
||||
/* NB: Multiply wchar_t count by 4 to get the number of bytes. */
|
||||
sall $2, %eax
|
||||
# endif
|
||||
/* 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
|
||||
ret
|
||||
|
||||
.p2align 4
|
||||
L(max):
|
||||
movq %r8, %rax
|
||||
# ifdef USE_AS_WCSLEN
|
||||
shrq $2, %rax
|
||||
# endif
|
||||
ret
|
||||
|
||||
.p2align 4
|
||||
L(zero):
|
||||
xorl %eax, %eax
|
||||
cmovb %esi, %eax
|
||||
ret
|
||||
# endif
|
||||
|
||||
.p2align 4
|
||||
L(first_vec_x0):
|
||||
tzcntl %eax, %eax
|
||||
# ifdef USE_AS_WCSLEN
|
||||
/* NB: Multiply wchar_t count by 4 to get the number of bytes. */
|
||||
sall $2, %eax
|
||||
# endif
|
||||
addq %rdi, %rax
|
||||
subq %rdx, %rax
|
||||
# ifdef USE_AS_WCSLEN
|
||||
shrq $2, %rax
|
||||
# endif
|
||||
ret
|
||||
|
||||
.p2align 4
|
||||
L(first_vec_x1):
|
||||
tzcntl %eax, %eax
|
||||
# ifdef USE_AS_WCSLEN
|
||||
/* NB: Multiply wchar_t count by 4 to get the number of bytes. */
|
||||
sall $2, %eax
|
||||
# endif
|
||||
addq $VEC_SIZE, %rax
|
||||
addq %rdi, %rax
|
||||
subq %rdx, %rax
|
||||
# ifdef USE_AS_WCSLEN
|
||||
shrq $2, %rax
|
||||
# endif
|
||||
ret
|
||||
|
||||
.p2align 4
|
||||
L(first_vec_x2):
|
||||
tzcntl %eax, %eax
|
||||
# ifdef USE_AS_WCSLEN
|
||||
/* NB: Multiply wchar_t count by 4 to get the number of bytes. */
|
||||
sall $2, %eax
|
||||
# endif
|
||||
addq $(VEC_SIZE * 2), %rax
|
||||
addq %rdi, %rax
|
||||
subq %rdx, %rax
|
||||
# ifdef USE_AS_WCSLEN
|
||||
shrq $2, %rax
|
||||
# endif
|
||||
ret
|
||||
|
||||
.p2align 4
|
||||
L(4x_vec_end):
|
||||
VPCMP $0, %YMM1, %YMMZERO, %k0
|
||||
kmovd %k0, %eax
|
||||
testl %eax, %eax
|
||||
jnz L(first_vec_x0)
|
||||
VPCMP $0, %YMM2, %YMMZERO, %k1
|
||||
kmovd %k1, %eax
|
||||
testl %eax, %eax
|
||||
jnz L(first_vec_x1)
|
||||
VPCMP $0, %YMM3, %YMMZERO, %k2
|
||||
kmovd %k2, %eax
|
||||
testl %eax, %eax
|
||||
jnz L(first_vec_x2)
|
||||
VPCMP $0, %YMM4, %YMMZERO, %k3
|
||||
kmovd %k3, %eax
|
||||
L(first_vec_x3):
|
||||
tzcntl %eax, %eax
|
||||
# ifdef USE_AS_WCSLEN
|
||||
/* NB: Multiply wchar_t count by 4 to get the number of bytes. */
|
||||
sall $2, %eax
|
||||
# endif
|
||||
addq $(VEC_SIZE * 3), %rax
|
||||
addq %rdi, %rax
|
||||
subq %rdx, %rax
|
||||
# ifdef USE_AS_WCSLEN
|
||||
shrq $2, %rax
|
||||
# endif
|
||||
ret
|
||||
|
||||
END (STRLEN)
|
||||
#endif
|
||||
|
||||
Loading…
Reference in New Issue
Block a user