forked from rpms/glibc
768 lines
19 KiB
Diff
768 lines
19 KiB
Diff
From aaa23c35071537e2dcf5807e956802ed215210aa Mon Sep 17 00:00:00 2001
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From: Noah Goldstein <goldstein.w.n@gmail.com>
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Date: Mon, 19 Apr 2021 19:36:07 -0400
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Subject: [PATCH] x86: Optimize strlen-avx2.S
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Content-type: text/plain; charset=UTF-8
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No bug. This commit optimizes strlen-avx2.S. The optimizations are
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mostly small things but they add up to roughly 10-30% performance
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improvement for strlen. The results for strnlen are bit more
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ambiguous. test-strlen, test-strnlen, test-wcslen, and test-wcsnlen
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are all passing.
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Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com>
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---
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sysdeps/x86_64/multiarch/ifunc-impl-list.c | 16 +-
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sysdeps/x86_64/multiarch/strlen-avx2.S | 532 +++++++++++++--------
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2 files changed, 334 insertions(+), 214 deletions(-)
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diff --git a/sysdeps/x86_64/multiarch/ifunc-impl-list.c b/sysdeps/x86_64/multiarch/ifunc-impl-list.c
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index cbfc1a5d..f1a6460a 100644
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--- a/sysdeps/x86_64/multiarch/ifunc-impl-list.c
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+++ b/sysdeps/x86_64/multiarch/ifunc-impl-list.c
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@@ -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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- CPU_FEATURE_USABLE (AVX2),
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+ (CPU_FEATURE_USABLE (AVX2)
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+ && CPU_FEATURE_USABLE (BMI2)),
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__strlen_avx2)
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IFUNC_IMPL_ADD (array, i, strlen,
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(CPU_FEATURE_USABLE (AVX2)
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+ && CPU_FEATURE_USABLE (BMI2)
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&& CPU_FEATURE_USABLE (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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- CPU_FEATURE_USABLE (AVX2),
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+ (CPU_FEATURE_USABLE (AVX2)
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+ && CPU_FEATURE_USABLE (BMI2)),
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__strnlen_avx2)
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IFUNC_IMPL_ADD (array, i, strnlen,
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(CPU_FEATURE_USABLE (AVX2)
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+ && CPU_FEATURE_USABLE (BMI2)
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&& CPU_FEATURE_USABLE (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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- CPU_FEATURE_USABLE (AVX2),
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+ (CPU_FEATURE_USABLE (AVX2)
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+ && CPU_FEATURE_USABLE (BMI2)),
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__wcslen_avx2)
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IFUNC_IMPL_ADD (array, i, wcslen,
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(CPU_FEATURE_USABLE (AVX2)
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+ && CPU_FEATURE_USABLE (BMI2)
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&& CPU_FEATURE_USABLE (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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- CPU_FEATURE_USABLE (AVX2),
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+ (CPU_FEATURE_USABLE (AVX2)
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+ && CPU_FEATURE_USABLE (BMI2)),
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__wcsnlen_avx2)
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IFUNC_IMPL_ADD (array, i, wcsnlen,
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(CPU_FEATURE_USABLE (AVX2)
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+ && CPU_FEATURE_USABLE (BMI2)
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&& CPU_FEATURE_USABLE (RTM)),
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__wcsnlen_avx2_rtm)
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IFUNC_IMPL_ADD (array, i, wcsnlen,
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diff --git a/sysdeps/x86_64/multiarch/strlen-avx2.S b/sysdeps/x86_64/multiarch/strlen-avx2.S
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index 82826e10..be8a5db5 100644
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--- a/sysdeps/x86_64/multiarch/strlen-avx2.S
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+++ b/sysdeps/x86_64/multiarch/strlen-avx2.S
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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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-
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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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-
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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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-
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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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+ /* 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_WCSLEN
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+ shrl $2, %eax
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+# endif
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+ VZEROUPPER_RETURN
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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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+L(zero):
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+ xorl %eax, %eax
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+ ret
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- subq $(VEC_SIZE * 4), %rsi
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- jbe L(last_4x_vec_or_less)
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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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+# 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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- 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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- testl %eax, %eax
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- jz L(aligned_more)
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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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- /* Check the end of data. */
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- cmpq %rax, %rsi
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- jbe L(max)
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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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- 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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+ VZEROUPPER_RETURN
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.p2align 4
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-L(aligned_more):
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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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- /* "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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-
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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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+ /* 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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- addq $VEC_SIZE, %rdi
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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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+ subl $(VEC_SIZE * 2 + 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 * 2 + 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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+ .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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- subq $(VEC_SIZE * 4), %rsi
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- jbe L(last_4x_vec_or_less)
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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 + 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 * 3 + 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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-L(more_4x_vec):
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+ .p2align 5
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+L(aligned_more):
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+ /* Align data to VEC_SIZE - 1. This is the same number of
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+ instructions as using andq with -VEC_SIZE but saves 4 bytes of
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+ code on the x4 check. */
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+ orq $(VEC_SIZE - 1), %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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- 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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-
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- VPCMPEQ VEC_SIZE(%rdi), %ymm0, %ymm1
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- vpmovmskb %ymm1, %eax
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+# ifdef USE_AS_STRNLEN
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+ /* + 1 because rdi is aligned to VEC_SIZE - 1. + CHAR_SIZE because
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+ it simplies the logic in last_4x_vec_or_less. */
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+ leaq (VEC_SIZE * 4 + CHAR_SIZE + 1)(%rdi), %rcx
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+ subq %rdx, %rcx
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+# endif
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+ /* Load first VEC regardless. */
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+ VPCMPEQ 1(%rdi), %ymm0, %ymm1
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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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+ 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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+ VPCMPEQ (VEC_SIZE + 1)(%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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+ VPCMPEQ (VEC_SIZE * 2 + 1)(%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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-
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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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-
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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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+ VPCMPEQ (VEC_SIZE * 3 + 1)(%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_x4)
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+ /* Align data to VEC_SIZE * 4 - 1. */
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# ifdef USE_AS_STRNLEN
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- /* Adjust length. */
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+ /* Before adjusting length check if at last VEC_SIZE * 4. */
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+ cmpq $(VEC_SIZE * 4 - 1), %rsi
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+ jbe L(last_4x_vec_or_less_load)
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+ incq %rdi
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+ movl %edi, %ecx
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+ orq $(VEC_SIZE * 4 - 1), %rdi
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+ andl $(VEC_SIZE * 4 - 1), %ecx
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+ /* Readjust length. */
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addq %rcx, %rsi
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+# else
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+ incq %rdi
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+ orq $(VEC_SIZE * 4 - 1), %rdi
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# endif
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-
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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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- 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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-
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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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-
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- addq $(VEC_SIZE * 4), %rdi
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-
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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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+# ifdef USE_AS_STRNLEN
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+ /* Break if at end of length. */
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subq $(VEC_SIZE * 4), %rsi
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- ja L(loop_4x_vec)
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-
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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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+ 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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+ vmovdqa 1(%rdi), %ymm1
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+ VPMINU (VEC_SIZE + 1)(%rdi), %ymm1, %ymm2
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+ vmovdqa (VEC_SIZE * 2 + 1)(%rdi), %ymm3
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+ VPMINU (VEC_SIZE * 3 + 1)(%rdi), %ymm3, %ymm4
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+
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+ VPMINU %ymm2, %ymm4, %ymm5
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+ VPCMPEQ %ymm5, %ymm0, %ymm5
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+ vpmovmskb %ymm5, %ecx
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|
|
- VPCMPEQ (%rdi), %ymm0, %ymm1
|
|
- vpmovmskb %ymm1, %eax
|
|
- testl %eax, %eax
|
|
- jnz L(first_vec_x0)
|
|
+ subq $-(VEC_SIZE * 4), %rdi
|
|
+ testl %ecx, %ecx
|
|
+ jz L(loop_4x_vec)
|
|
|
|
- VPCMPEQ VEC_SIZE(%rdi), %ymm0, %ymm1
|
|
- vpmovmskb %ymm1, %eax
|
|
- testl %eax, %eax
|
|
- jnz L(first_vec_x1)
|
|
|
|
- VPCMPEQ (VEC_SIZE * 2)(%rdi), %ymm0, %ymm1
|
|
- vpmovmskb %ymm1, %eax
|
|
+ VPCMPEQ %ymm1, %ymm0, %ymm1
|
|
+ vpmovmskb %ymm1, %eax
|
|
+ subq %rdx, %rdi
|
|
testl %eax, %eax
|
|
+ jnz L(last_vec_return_x0)
|
|
|
|
- jnz L(first_vec_x2_check)
|
|
- subl $VEC_SIZE, %esi
|
|
- jle L(max)
|
|
-
|
|
- VPCMPEQ (VEC_SIZE * 3)(%rdi), %ymm0, %ymm1
|
|
- vpmovmskb %ymm1, %eax
|
|
+ VPCMPEQ %ymm2, %ymm0, %ymm2
|
|
+ vpmovmskb %ymm2, %eax
|
|
testl %eax, %eax
|
|
-
|
|
- jnz L(first_vec_x3_check)
|
|
- movq %r8, %rax
|
|
-# ifdef USE_AS_WCSLEN
|
|
+ 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
|
|
+# endif
|
|
VZEROUPPER_RETURN
|
|
|
|
+
|
|
+# ifdef USE_AS_STRNLEN
|
|
.p2align 4
|
|
-L(last_2x_vec):
|
|
- addl $(VEC_SIZE * 2), %esi
|
|
- VPCMPEQ (%rdi), %ymm0, %ymm1
|
|
- vpmovmskb %ymm1, %eax
|
|
- testl %eax, %eax
|
|
+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):
|
|
|
|
- jnz L(first_vec_x0_check)
|
|
- subl $VEC_SIZE, %esi
|
|
- jle L(max)
|
|
+ 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)
|
|
|
|
- VPCMPEQ VEC_SIZE(%rdi), %ymm0, %ymm1
|
|
- vpmovmskb %ymm1, %eax
|
|
+ /* 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(first_vec_x1_check)
|
|
- movq %r8, %rax
|
|
-# ifdef USE_AS_WCSLEN
|
|
- shrq $2, %rax
|
|
-# endif
|
|
- VZEROUPPER_RETURN
|
|
+ jnz L(last_vec_x1_check)
|
|
|
|
- .p2align 4
|
|
-L(first_vec_x0_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. */
|
|
- cmpq %rax, %rsi
|
|
- jbe L(max)
|
|
+ cmpl %eax, %esi
|
|
+ jb L(max)
|
|
+ subq %rdx, %rdi
|
|
+ addl $(VEC_SIZE + 1), %eax
|
|
addq %rdi, %rax
|
|
- subq %rdx, %rax
|
|
# ifdef USE_AS_WCSLEN
|
|
shrq $2, %rax
|
|
# endif
|
|
VZEROUPPER_RETURN
|
|
+# endif
|
|
|
|
.p2align 4
|
|
-L(first_vec_x1_check):
|
|
+L(last_vec_return_x0):
|
|
tzcntl %eax, %eax
|
|
- /* Check the end of data. */
|
|
- cmpq %rax, %rsi
|
|
- jbe L(max)
|
|
- addq $VEC_SIZE, %rax
|
|
+ subq $(VEC_SIZE * 4 - 1), %rdi
|
|
addq %rdi, %rax
|
|
- subq %rdx, %rax
|
|
-# ifdef USE_AS_WCSLEN
|
|
+# ifdef USE_AS_WCSLEN
|
|
shrq $2, %rax
|
|
-# endif
|
|
+# endif
|
|
VZEROUPPER_RETURN
|
|
|
|
.p2align 4
|
|
-L(first_vec_x2_check):
|
|
+L(last_vec_return_x1):
|
|
tzcntl %eax, %eax
|
|
- /* Check the end of data. */
|
|
- cmpq %rax, %rsi
|
|
- jbe L(max)
|
|
- addq $(VEC_SIZE * 2), %rax
|
|
+ subq $(VEC_SIZE * 3 - 1), %rdi
|
|
addq %rdi, %rax
|
|
- subq %rdx, %rax
|
|
-# ifdef USE_AS_WCSLEN
|
|
+# ifdef USE_AS_WCSLEN
|
|
shrq $2, %rax
|
|
-# endif
|
|
+# endif
|
|
VZEROUPPER_RETURN
|
|
|
|
+# ifdef USE_AS_STRNLEN
|
|
.p2align 4
|
|
-L(first_vec_x3_check):
|
|
+L(last_vec_x1_check):
|
|
+
|
|
tzcntl %eax, %eax
|
|
/* Check the end of data. */
|
|
- cmpq %rax, %rsi
|
|
- jbe L(max)
|
|
- addq $(VEC_SIZE * 3), %rax
|
|
+ cmpl %eax, %esi
|
|
+ jb L(max)
|
|
+ subq %rdx, %rdi
|
|
+ incl %eax
|
|
addq %rdi, %rax
|
|
- subq %rdx, %rax
|
|
# ifdef USE_AS_WCSLEN
|
|
shrq $2, %rax
|
|
# endif
|
|
VZEROUPPER_RETURN
|
|
|
|
- .p2align 4
|
|
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(zero):
|
|
- xorl %eax, %eax
|
|
- ret
|
|
-# endif
|
|
|
|
.p2align 4
|
|
-L(first_vec_x0):
|
|
+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
|
|
- subq %rdx, %rax
|
|
-# ifdef USE_AS_WCSLEN
|
|
+# ifdef USE_AS_WCSLEN
|
|
shrq $2, %rax
|
|
-# endif
|
|
+# endif
|
|
VZEROUPPER_RETURN
|
|
|
|
.p2align 4
|
|
-L(first_vec_x1):
|
|
+L(last_vec_x2):
|
|
+ /* essentially duplicates of first_vec_x1 but use 64 bit
|
|
+ instructions. */
|
|
tzcntl %eax, %eax
|
|
- addq $VEC_SIZE, %rax
|
|
+ subq %rdx, %rdi
|
|
+ addl $(VEC_SIZE + 1), %eax
|
|
addq %rdi, %rax
|
|
- subq %rdx, %rax
|
|
-# ifdef USE_AS_WCSLEN
|
|
+# ifdef USE_AS_WCSLEN
|
|
shrq $2, %rax
|
|
-# endif
|
|
+# endif
|
|
VZEROUPPER_RETURN
|
|
|
|
.p2align 4
|
|
-L(first_vec_x2):
|
|
+L(last_vec_x3):
|
|
tzcntl %eax, %eax
|
|
- addq $(VEC_SIZE * 2), %rax
|
|
+ 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
|
|
- subq %rdx, %rax
|
|
-# ifdef USE_AS_WCSLEN
|
|
+# ifdef USE_AS_WCSLEN
|
|
shrq $2, %rax
|
|
-# endif
|
|
+# endif
|
|
+ VZEROUPPER_RETURN
|
|
+L(max_end):
|
|
+ movq %r8, %rax
|
|
VZEROUPPER_RETURN
|
|
+# endif
|
|
|
|
+ /* Cold case for crossing page with first load. */
|
|
.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
|
|
+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(first_vec_x1)
|
|
- VPCMPEQ %ymm3, %ymm0, %ymm3
|
|
- vpmovmskb %ymm3, %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
|
|
- jnz L(first_vec_x2)
|
|
- VPCMPEQ %ymm4, %ymm0, %ymm4
|
|
- vpmovmskb %ymm4, %eax
|
|
-L(first_vec_x3):
|
|
+ jz L(cross_page_continue)
|
|
tzcntl %eax, %eax
|
|
- addq $(VEC_SIZE * 3), %rax
|
|
- addq %rdi, %rax
|
|
- subq %rdx, %rax
|
|
-# ifdef USE_AS_WCSLEN
|
|
- shrq $2, %rax
|
|
+# 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
|
|
--
|
|
GitLab
|
|
|