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https://sourceware.org/git/glibc.git
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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>
(cherry picked from commit aaa23c3507)
This commit is contained in:
Noah Goldstein
H.J. Lu
parent
c51e9501c2
commit
0a3b2efccc
@ -285,10 +285,12 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
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/* Support sysdeps/x86_64/multiarch/strlen.c. */
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IFUNC_IMPL (i, name, strlen,
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IFUNC_IMPL_ADD (array, i, strlen,
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HAS_ARCH_FEATURE (AVX2_Usable),
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(HAS_ARCH_FEATURE (AVX2_Usable)
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&& HAS_CPU_FEATURE (BMI2)),
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__strlen_avx2)
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IFUNC_IMPL_ADD (array, i, strlen,
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(HAS_ARCH_FEATURE (AVX2_Usable)
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&& HAS_CPU_FEATURE (BMI2)
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&& HAS_CPU_FEATURE (RTM)),
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__strlen_avx2_rtm)
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IFUNC_IMPL_ADD (array, i, strlen,
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@ -301,10 +303,12 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
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/* Support sysdeps/x86_64/multiarch/strnlen.c. */
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IFUNC_IMPL (i, name, strnlen,
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IFUNC_IMPL_ADD (array, i, strnlen,
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HAS_ARCH_FEATURE (AVX2_Usable),
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(HAS_ARCH_FEATURE (AVX2_Usable)
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&& HAS_CPU_FEATURE (BMI2)),
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__strnlen_avx2)
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IFUNC_IMPL_ADD (array, i, strnlen,
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(HAS_ARCH_FEATURE (AVX2_Usable)
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&& HAS_CPU_FEATURE (BMI2)
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&& HAS_CPU_FEATURE (RTM)),
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__strnlen_avx2_rtm)
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IFUNC_IMPL_ADD (array, i, strnlen,
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@ -640,10 +644,12 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
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/* Support sysdeps/x86_64/multiarch/wcslen.c. */
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IFUNC_IMPL (i, name, wcslen,
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IFUNC_IMPL_ADD (array, i, wcslen,
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HAS_ARCH_FEATURE (AVX2_Usable),
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(HAS_ARCH_FEATURE (AVX2_Usable)
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&& HAS_CPU_FEATURE (BMI2)),
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__wcslen_avx2)
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IFUNC_IMPL_ADD (array, i, wcslen,
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(HAS_ARCH_FEATURE (AVX2_Usable)
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&& HAS_CPU_FEATURE (BMI2)
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&& HAS_CPU_FEATURE (RTM)),
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__wcslen_avx2_rtm)
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IFUNC_IMPL_ADD (array, i, wcslen,
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@ -656,10 +662,12 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
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/* Support sysdeps/x86_64/multiarch/wcsnlen.c. */
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IFUNC_IMPL (i, name, wcsnlen,
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IFUNC_IMPL_ADD (array, i, wcsnlen,
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HAS_ARCH_FEATURE (AVX2_Usable),
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(HAS_ARCH_FEATURE (AVX2_Usable)
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&& HAS_CPU_FEATURE (BMI2)),
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__wcsnlen_avx2)
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IFUNC_IMPL_ADD (array, i, wcsnlen,
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(HAS_ARCH_FEATURE (AVX2_Usable)
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&& HAS_CPU_FEATURE (BMI2)
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&& HAS_CPU_FEATURE (RTM)),
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__wcsnlen_avx2_rtm)
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IFUNC_IMPL_ADD (array, i, wcsnlen,
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@ -27,9 +27,11 @@
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# ifdef USE_AS_WCSLEN
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# define VPCMPEQ vpcmpeqd
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# define VPMINU vpminud
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# define CHAR_SIZE 4
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# else
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# define VPCMPEQ vpcmpeqb
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# define VPMINU vpminub
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# define CHAR_SIZE 1
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# endif
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# ifndef VZEROUPPER
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@ -41,349 +43,459 @@
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# endif
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# define VEC_SIZE 32
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# define PAGE_SIZE 4096
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.section SECTION(.text),"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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/* Store max len in R8_LP before adjusting if using WCSLEN. */
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mov %RSI_LP, %R8_LP
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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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/* 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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movl %edi, %eax
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movq %rdi, %rdx
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vpxor %xmm0, %xmm0, %xmm0
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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. */
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VPCMPEQ (%rdi), %ymm0, %ymm1
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vpmovmskb %ymm1, %eax
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testl %eax, %eax
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VPCMPEQ (%rdi), %ymm0, %ymm1
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vpmovmskb %ymm1, %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 < VEC_SIZE handle special. */
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cmpq $VEC_SIZE, %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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VPCMPEQ (%rdi), %ymm0, %ymm1
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vpmovmskb %ymm1, %eax
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/* Remove the leading bytes. */
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sarl %cl, %eax
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/* If empty continue to aligned_more. Otherwise return bit
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position of first match. */
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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_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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# 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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shrl $2, %eax
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# endif
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L(return_vzeroupper):
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ZERO_UPPER_VEC_REGISTERS_RETURN
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.p2align 4
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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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VZEROUPPER_RETURN
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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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/* 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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VPCMPEQ (%rdi), %ymm0, %ymm1
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vpmovmskb %ymm1, %eax
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testl %eax, %eax
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jnz L(first_vec_x0)
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VPCMPEQ VEC_SIZE(%rdi), %ymm0, %ymm1
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vpmovmskb %ymm1, %eax
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testl %eax, %eax
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jnz L(first_vec_x1)
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VPCMPEQ (VEC_SIZE * 2)(%rdi), %ymm0, %ymm1
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vpmovmskb %ymm1, %eax
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testl %eax, %eax
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jnz L(first_vec_x2)
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VPCMPEQ (VEC_SIZE * 3)(%rdi), %ymm0, %ymm1
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vpmovmskb %ymm1, %eax
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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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# 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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addq %rcx, %rsi
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# endif
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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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vmovdqa (%rdi), %ymm1
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vmovdqa VEC_SIZE(%rdi), %ymm2
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vmovdqa (VEC_SIZE * 2)(%rdi), %ymm3
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vmovdqa (VEC_SIZE * 3)(%rdi), %ymm4
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VPMINU %ymm1, %ymm2, %ymm5
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VPMINU %ymm3, %ymm4, %ymm6
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VPMINU %ymm5, %ymm6, %ymm5
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VPCMPEQ %ymm5, %ymm0, %ymm5
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vpmovmskb %ymm5, %eax
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testl %eax, %eax
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jnz L(4x_vec_end)
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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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# else
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subq $(VEC_SIZE * 4), %rsi
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ja L(loop_4x_vec)
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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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VPCMPEQ (%rdi), %ymm0, %ymm1
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vpmovmskb %ymm1, %eax
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testl %eax, %eax
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jnz L(first_vec_x0)
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VPCMPEQ VEC_SIZE(%rdi), %ymm0, %ymm1
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vpmovmskb %ymm1, %eax
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testl %eax, %eax
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jnz L(first_vec_x1)
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VPCMPEQ (VEC_SIZE * 2)(%rdi), %ymm0, %ymm1
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vpmovmskb %ymm1, %eax
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testl %eax, %eax
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jnz L(first_vec_x2_check)
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subl $VEC_SIZE, %esi
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jle L(max)
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VPCMPEQ (VEC_SIZE * 3)(%rdi), %ymm0, %ymm1
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vpmovmskb %ymm1, %eax
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testl %eax, %eax
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jnz L(first_vec_x3_check)
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movq %r8, %rax
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# ifdef USE_AS_WCSLEN
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shrq $2, %rax
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# endif
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VZEROUPPER_RETURN
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.p2align 4
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L(last_2x_vec):
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addl $(VEC_SIZE * 2), %esi
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VPCMPEQ (%rdi), %ymm0, %ymm1
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vpmovmskb %ymm1, %eax
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testl %eax, %eax
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jnz L(first_vec_x0_check)
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subl $VEC_SIZE, %esi
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jle L(max)
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VPCMPEQ VEC_SIZE(%rdi), %ymm0, %ymm1
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vpmovmskb %ymm1, %eax
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testl %eax, %eax
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jnz L(first_vec_x1_check)
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movq %r8, %rax
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# ifdef USE_AS_WCSLEN
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shrq $2, %rax
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# endif
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VZEROUPPER_RETURN
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.p2align 4
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L(first_vec_x0_check):
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tzcntl %eax, %eax
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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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addq %rdi, %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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# endif
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VZEROUPPER_RETURN
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.p2align 4
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L(first_vec_x1_check):
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tzcntl %eax, %eax
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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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addq $VEC_SIZE, %rax
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addq %rdi, %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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# endif
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VZEROUPPER_RETURN
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.p2align 4
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L(first_vec_x2_check):
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tzcntl %eax, %eax
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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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addq $(VEC_SIZE * 2), %rax
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addq %rdi, %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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# endif
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VZEROUPPER_RETURN
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.p2align 4
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L(first_vec_x3_check):
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tzcntl %eax, %eax
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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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addq $(VEC_SIZE * 3), %rax
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addq %rdi, %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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# endif
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VZEROUPPER_RETURN
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.p2align 4
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L(max):
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movq %r8, %rax
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# ifdef USE_AS_WCSLEN
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shrq $2, %rax
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# endif
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VZEROUPPER_RETURN
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.p2align 4
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L(zero):
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xorl %eax, %eax
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ret
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# endif
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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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addq %rdi, %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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# endif
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# ifdef USE_AS_WCSLEN
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shrl $2, %eax
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# endif
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VZEROUPPER_RETURN
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# endif
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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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addq $VEC_SIZE, %rax
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addq %rdi, %rax
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subq %rdx, %rax
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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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subl $(VEC_SIZE * 4 + 1), %ecx
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addl %ecx, %eax
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# else
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subl %edx, %edi
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incl %edi
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addl %edi, %eax
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# endif
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# ifdef USE_AS_WCSLEN
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shrq $2, %rax
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shrl $2, %eax
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# endif
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VZEROUPPER_RETURN
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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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addq $(VEC_SIZE * 2), %rax
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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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subl $(VEC_SIZE * 3 + 1), %ecx
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addl %ecx, %eax
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# else
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subl %edx, %edi
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addl $(VEC_SIZE + 1), %edi
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addl %edi, %eax
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# endif
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# ifdef USE_AS_WCSLEN
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shrl $2, %eax
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# endif
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VZEROUPPER_RETURN
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|
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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]. */
|
||||
# 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