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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>
(cherry picked from commit 4ba6558684)
This commit is contained in:
Noah Goldstein
H.J. Lu
parent
709eb51aff
commit
6864c340a1
@ -29,11 +29,13 @@
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# ifdef USE_AS_WCSLEN
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# define VPCMP vpcmpd
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# define VPMINU vpminud
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# define SHIFT_REG r9d
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# define SHIFT_REG ecx
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# define CHAR_SIZE 4
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# else
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# define VPCMP vpcmpb
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# define VPMINU vpminub
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# define SHIFT_REG ecx
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# define SHIFT_REG edx
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# define CHAR_SIZE 1
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# endif
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# define XMMZERO xmm16
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@ -46,132 +48,165 @@
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# define YMM6 ymm22
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# define VEC_SIZE 32
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# define PAGE_SIZE 4096
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# define CHAR_PER_VEC (VEC_SIZE / CHAR_SIZE)
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.section .text.evex,"ax",@progbits
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ENTRY (STRLEN)
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# ifdef USE_AS_STRNLEN
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/* Check for zero length. */
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/* Check zero length. */
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test %RSI_LP, %RSI_LP
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jz L(zero)
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# ifdef USE_AS_WCSLEN
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shl $2, %RSI_LP
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# elif defined __ILP32__
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# ifdef __ILP32__
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/* Clear the upper 32 bits. */
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movl %esi, %esi
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# endif
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mov %RSI_LP, %R8_LP
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# endif
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movl %edi, %ecx
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movq %rdi, %rdx
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movl %edi, %eax
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vpxorq %XMMZERO, %XMMZERO, %XMMZERO
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/* Clear high bits from edi. Only keeping bits relevant to page
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cross check. */
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andl $(PAGE_SIZE - 1), %eax
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/* Check if we may cross page boundary with one vector load. */
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andl $(2 * VEC_SIZE - 1), %ecx
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cmpl $VEC_SIZE, %ecx
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ja L(cros_page_boundary)
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cmpl $(PAGE_SIZE - VEC_SIZE), %eax
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ja L(cross_page_boundary)
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/* Check the first VEC_SIZE bytes. Each bit in K0 represents a
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null byte. */
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VPCMP $0, (%rdi), %YMMZERO, %k0
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kmovd %k0, %eax
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testl %eax, %eax
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# ifdef USE_AS_STRNLEN
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jnz L(first_vec_x0_check)
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/* Adjust length and check the end of data. */
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subq $VEC_SIZE, %rsi
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jbe L(max)
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# else
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jnz L(first_vec_x0)
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/* If length < CHAR_PER_VEC handle special. */
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cmpq $CHAR_PER_VEC, %rsi
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jbe L(first_vec_x0)
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# endif
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/* Align data for aligned loads in the loop. */
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addq $VEC_SIZE, %rdi
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andl $(VEC_SIZE - 1), %ecx
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andq $-VEC_SIZE, %rdi
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# ifdef USE_AS_STRNLEN
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/* Adjust length. */
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addq %rcx, %rsi
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subq $(VEC_SIZE * 4), %rsi
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jbe L(last_4x_vec_or_less)
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# endif
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jmp L(more_4x_vec)
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.p2align 4
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L(cros_page_boundary):
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andl $(VEC_SIZE - 1), %ecx
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andq $-VEC_SIZE, %rdi
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# ifdef USE_AS_WCSLEN
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/* NB: Divide shift count by 4 since each bit in K0 represent 4
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bytes. */
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movl %ecx, %SHIFT_REG
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sarl $2, %SHIFT_REG
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# endif
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VPCMP $0, (%rdi), %YMMZERO, %k0
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kmovd %k0, %eax
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/* Remove the leading bytes. */
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sarxl %SHIFT_REG, %eax, %eax
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testl %eax, %eax
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jz L(aligned_more)
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tzcntl %eax, %eax
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# ifdef USE_AS_WCSLEN
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/* NB: Multiply wchar_t count by 4 to get the number of bytes. */
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sall $2, %eax
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# endif
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ret
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# ifdef USE_AS_STRNLEN
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/* Check the end of data. */
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cmpq %rax, %rsi
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jbe L(max)
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L(zero):
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xorl %eax, %eax
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ret
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.p2align 4
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L(first_vec_x0):
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/* Set bit for max len so that tzcnt will return min of max len
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and position of first match. */
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btsq %rsi, %rax
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tzcntl %eax, %eax
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ret
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# endif
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addq %rdi, %rax
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addq %rcx, %rax
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subq %rdx, %rax
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# ifdef USE_AS_WCSLEN
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shrq $2, %rax
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.p2align 4
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L(first_vec_x1):
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tzcntl %eax, %eax
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/* Safe to use 32 bit instructions as these are only called for
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size = [1, 159]. */
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# ifdef USE_AS_STRNLEN
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/* Use ecx which was computed earlier to compute correct value.
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*/
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leal -(CHAR_PER_VEC * 4 + 1)(%rcx, %rax), %eax
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# else
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subl %edx, %edi
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# ifdef USE_AS_WCSLEN
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/* NB: Divide bytes by 4 to get the wchar_t count. */
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sarl $2, %edi
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# endif
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leal CHAR_PER_VEC(%rdi, %rax), %eax
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# endif
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ret
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.p2align 4
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L(first_vec_x2):
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tzcntl %eax, %eax
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/* Safe to use 32 bit instructions as these are only called for
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size = [1, 159]. */
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# ifdef USE_AS_STRNLEN
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/* Use ecx which was computed earlier to compute correct value.
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*/
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leal -(CHAR_PER_VEC * 3 + 1)(%rcx, %rax), %eax
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# else
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subl %edx, %edi
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# ifdef USE_AS_WCSLEN
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/* NB: Divide bytes by 4 to get the wchar_t count. */
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sarl $2, %edi
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# endif
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leal (CHAR_PER_VEC * 2)(%rdi, %rax), %eax
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# endif
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ret
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.p2align 4
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L(first_vec_x3):
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tzcntl %eax, %eax
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/* Safe to use 32 bit instructions as these are only called for
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size = [1, 159]. */
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# ifdef USE_AS_STRNLEN
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/* Use ecx which was computed earlier to compute correct value.
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*/
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leal -(CHAR_PER_VEC * 2 + 1)(%rcx, %rax), %eax
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# else
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subl %edx, %edi
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# ifdef USE_AS_WCSLEN
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/* NB: Divide bytes by 4 to get the wchar_t count. */
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sarl $2, %edi
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# endif
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leal (CHAR_PER_VEC * 3)(%rdi, %rax), %eax
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# endif
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ret
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.p2align 4
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L(first_vec_x4):
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tzcntl %eax, %eax
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/* Safe to use 32 bit instructions as these are only called for
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size = [1, 159]. */
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# ifdef USE_AS_STRNLEN
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/* Use ecx which was computed earlier to compute correct value.
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*/
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leal -(CHAR_PER_VEC + 1)(%rcx, %rax), %eax
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# else
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subl %edx, %edi
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# ifdef USE_AS_WCSLEN
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/* NB: Divide bytes by 4 to get the wchar_t count. */
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sarl $2, %edi
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# endif
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leal (CHAR_PER_VEC * 4)(%rdi, %rax), %eax
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# endif
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ret
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.p2align 5
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L(aligned_more):
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# ifdef USE_AS_STRNLEN
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/* "rcx" is less than VEC_SIZE. Calculate "rdx + rcx - VEC_SIZE"
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with "rdx - (VEC_SIZE - rcx)" instead of "(rdx + rcx) - VEC_SIZE"
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to void possible addition overflow. */
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negq %rcx
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addq $VEC_SIZE, %rcx
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/* Check the end of data. */
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subq %rcx, %rsi
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jbe L(max)
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# endif
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addq $VEC_SIZE, %rdi
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# ifdef USE_AS_STRNLEN
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subq $(VEC_SIZE * 4), %rsi
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jbe L(last_4x_vec_or_less)
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# endif
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L(more_4x_vec):
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movq %rdi, %rdx
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/* Align data to VEC_SIZE. */
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andq $-(VEC_SIZE), %rdi
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L(cross_page_continue):
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/* Check the first 4 * VEC_SIZE. Only one VEC_SIZE at a time
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since data is only aligned to VEC_SIZE. */
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VPCMP $0, (%rdi), %YMMZERO, %k0
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kmovd %k0, %eax
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testl %eax, %eax
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jnz L(first_vec_x0)
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# ifdef USE_AS_STRNLEN
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/* + CHAR_SIZE because it simplies the logic in
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last_4x_vec_or_less. */
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leaq (VEC_SIZE * 5 + CHAR_SIZE)(%rdi), %rcx
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subq %rdx, %rcx
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# ifdef USE_AS_WCSLEN
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/* NB: Divide bytes by 4 to get the wchar_t count. */
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sarl $2, %ecx
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# endif
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# endif
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/* Load first VEC regardless. */
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VPCMP $0, VEC_SIZE(%rdi), %YMMZERO, %k0
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# ifdef USE_AS_STRNLEN
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/* Adjust length. If near end handle specially. */
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subq %rcx, %rsi
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jb L(last_4x_vec_or_less)
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# endif
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kmovd %k0, %eax
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testl %eax, %eax
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jnz L(first_vec_x1)
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VPCMP $0, (VEC_SIZE * 2)(%rdi), %YMMZERO, %k0
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kmovd %k0, %eax
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testl %eax, %eax
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test %eax, %eax
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jnz L(first_vec_x2)
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VPCMP $0, (VEC_SIZE * 3)(%rdi), %YMMZERO, %k0
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@ -179,258 +214,276 @@ L(more_4x_vec):
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testl %eax, %eax
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jnz L(first_vec_x3)
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addq $(VEC_SIZE * 4), %rdi
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VPCMP $0, (VEC_SIZE * 4)(%rdi), %YMMZERO, %k0
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kmovd %k0, %eax
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testl %eax, %eax
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jnz L(first_vec_x4)
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addq $VEC_SIZE, %rdi
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# ifdef USE_AS_STRNLEN
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subq $(VEC_SIZE * 4), %rsi
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jbe L(last_4x_vec_or_less)
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# endif
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/* Align data to 4 * VEC_SIZE. */
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movq %rdi, %rcx
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andl $(4 * VEC_SIZE - 1), %ecx
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andq $-(4 * VEC_SIZE), %rdi
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# ifdef USE_AS_STRNLEN
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/* Adjust length. */
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/* Check if at last VEC_SIZE * 4 length. */
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cmpq $(CHAR_PER_VEC * 4 - 1), %rsi
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jbe L(last_4x_vec_or_less_load)
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movl %edi, %ecx
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andl $(VEC_SIZE * 4 - 1), %ecx
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# ifdef USE_AS_WCSLEN
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/* NB: Divide bytes by 4 to get the wchar_t count. */
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sarl $2, %ecx
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# endif
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/* Readjust length. */
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addq %rcx, %rsi
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# endif
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/* Align data to VEC_SIZE * 4. */
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andq $-(VEC_SIZE * 4), %rdi
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/* Compare 4 * VEC at a time forward. */
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.p2align 4
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L(loop_4x_vec):
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/* Compare 4 * VEC at a time forward. */
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VMOVA (%rdi), %YMM1
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VMOVA VEC_SIZE(%rdi), %YMM2
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VMOVA (VEC_SIZE * 2)(%rdi), %YMM3
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VMOVA (VEC_SIZE * 3)(%rdi), %YMM4
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/* Load first VEC regardless. */
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VMOVA (VEC_SIZE * 4)(%rdi), %YMM1
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# ifdef USE_AS_STRNLEN
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/* Break if at end of length. */
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subq $(CHAR_PER_VEC * 4), %rsi
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jb L(last_4x_vec_or_less_cmpeq)
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# endif
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/* Save some code size by microfusing VPMINU with the load. Since
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the matches in ymm2/ymm4 can only be returned if there where no
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matches in ymm1/ymm3 respectively there is no issue with overlap.
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*/
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VPMINU (VEC_SIZE * 5)(%rdi), %YMM1, %YMM2
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VMOVA (VEC_SIZE * 6)(%rdi), %YMM3
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VPMINU (VEC_SIZE * 7)(%rdi), %YMM3, %YMM4
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VPMINU %YMM1, %YMM2, %YMM5
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VPMINU %YMM3, %YMM4, %YMM6
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VPCMP $0, %YMM2, %YMMZERO, %k0
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VPCMP $0, %YMM4, %YMMZERO, %k1
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subq $-(VEC_SIZE * 4), %rdi
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kortestd %k0, %k1
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jz L(loop_4x_vec)
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VPMINU %YMM5, %YMM6, %YMM5
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VPCMP $0, %YMM5, %YMMZERO, %k0
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ktestd %k0, %k0
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jnz L(4x_vec_end)
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/* Check if end was in first half. */
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kmovd %k0, %eax
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subq %rdx, %rdi
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# ifdef USE_AS_WCSLEN
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shrq $2, %rdi
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# endif
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testl %eax, %eax
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jz L(second_vec_return)
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addq $(VEC_SIZE * 4), %rdi
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# ifndef USE_AS_STRNLEN
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jmp L(loop_4x_vec)
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VPCMP $0, %YMM1, %YMMZERO, %k2
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kmovd %k2, %edx
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/* Combine VEC1 matches (edx) with VEC2 matches (eax). */
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# ifdef USE_AS_WCSLEN
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sall $CHAR_PER_VEC, %eax
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orl %edx, %eax
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tzcntl %eax, %eax
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# else
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subq $(VEC_SIZE * 4), %rsi
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ja L(loop_4x_vec)
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salq $CHAR_PER_VEC, %rax
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orq %rdx, %rax
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tzcntq %rax, %rax
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# endif
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addq %rdi, %rax
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ret
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# ifdef USE_AS_STRNLEN
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L(last_4x_vec_or_less_load):
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/* Depending on entry adjust rdi / prepare first VEC in YMM1. */
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VMOVA (VEC_SIZE * 4)(%rdi), %YMM1
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L(last_4x_vec_or_less_cmpeq):
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VPCMP $0, %YMM1, %YMMZERO, %k0
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addq $(VEC_SIZE * 3), %rdi
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L(last_4x_vec_or_less):
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/* Less than 4 * VEC and aligned to VEC_SIZE. */
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addl $(VEC_SIZE * 2), %esi
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jle L(last_2x_vec)
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VPCMP $0, (%rdi), %YMMZERO, %k0
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kmovd %k0, %eax
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testl %eax, %eax
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jnz L(first_vec_x0)
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/* If remaining length > VEC_SIZE * 2. This works if esi is off by
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VEC_SIZE * 4. */
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testl $(CHAR_PER_VEC * 2), %esi
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jnz L(last_4x_vec)
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VPCMP $0, VEC_SIZE(%rdi), %YMMZERO, %k0
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kmovd %k0, %eax
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/* length may have been negative or positive by an offset of
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CHAR_PER_VEC * 4 depending on where this was called from. This
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fixes that. */
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andl $(CHAR_PER_VEC * 4 - 1), %esi
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testl %eax, %eax
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jnz L(first_vec_x1)
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jnz L(last_vec_x1_check)
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/* Check the end of data. */
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subl $CHAR_PER_VEC, %esi
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jb L(max)
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VPCMP $0, (VEC_SIZE * 2)(%rdi), %YMMZERO, %k0
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kmovd %k0, %eax
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tzcntl %eax, %eax
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/* Check the end of data. */
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cmpl %eax, %esi
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jb L(max)
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subq %rdx, %rdi
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# ifdef USE_AS_WCSLEN
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/* NB: Divide bytes by 4 to get the wchar_t count. */
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sarq $2, %rdi
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# endif
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leaq (CHAR_PER_VEC * 2)(%rdi, %rax), %rax
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ret
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L(max):
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movq %r8, %rax
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ret
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# endif
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/* Placed here in strnlen so that the jcc L(last_4x_vec_or_less)
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in the 4x VEC loop can use 2 byte encoding. */
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.p2align 4
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L(second_vec_return):
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VPCMP $0, %YMM3, %YMMZERO, %k0
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/* Combine YMM3 matches (k0) with YMM4 matches (k1). */
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# ifdef USE_AS_WCSLEN
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kunpckbw %k0, %k1, %k0
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kmovd %k0, %eax
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tzcntl %eax, %eax
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# else
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kunpckdq %k0, %k1, %k0
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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