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2a2d048539
glibc/glibc-RHEL-15696-26.patch
DJ Delorie 02cfe04e36 Import Intel hyperscale improvements (RHEL-15696) 
Resolves: RHEL-15696

Includes two additional (well, 1.5) upstream patches
to resolve roundeven redirects.
2023-12-15 17:33:06 -05:00

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From 2a76821c3081d2c0231ecd2618f52662cb48fccd Mon Sep 17 00:00:00 2001
From: Noah Goldstein <goldstein.w.n@gmail.com>
Date: Mon, 3 May 2021 03:03:19 -0400
Subject: [PATCH] x86: Optimize memchr-evex.S
Content-type: text/plain; charset=UTF-8
No bug. This commit optimizes memchr-evex.S. The optimizations include
replacing some branches with cmovcc, avoiding some branches entirely
in the less_4x_vec case, making the page cross logic less strict,
saving some ALU in the alignment process, and most importantly
increasing ILP in the 4x loop. test-memchr, test-rawmemchr, and
test-wmemchr are all passing.
Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com>
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
---
sysdeps/x86_64/multiarch/memchr-evex.S | 547 +++++++++++++++----------
1 file changed, 322 insertions(+), 225 deletions(-)
diff --git a/sysdeps/x86_64/multiarch/memchr-evex.S b/sysdeps/x86_64/multiarch/memchr-evex.S
index 6dd5d67b..81d5cd64 100644
--- a/sysdeps/x86_64/multiarch/memchr-evex.S
+++ b/sysdeps/x86_64/multiarch/memchr-evex.S
@@ -26,14 +26,28 @@
# ifdef USE_AS_WMEMCHR
# define VPBROADCAST vpbroadcastd
-# define VPCMP vpcmpd
-# define SHIFT_REG r8d
+# define VPMINU vpminud
+# define VPCMP vpcmpd
+# define VPCMPEQ vpcmpeqd
+# define CHAR_SIZE 4
# else
# define VPBROADCAST vpbroadcastb
-# define VPCMP vpcmpb
-# define SHIFT_REG ecx
+# define VPMINU vpminub
+# define VPCMP vpcmpb
+# define VPCMPEQ vpcmpeqb
+# define CHAR_SIZE 1
# endif
+# ifdef USE_AS_RAWMEMCHR
+# define RAW_PTR_REG rcx
+# define ALGN_PTR_REG rdi
+# else
+# define RAW_PTR_REG rdi
+# define ALGN_PTR_REG rcx
+# endif
+
+# define XMMZERO xmm23
+# define YMMZERO ymm23
# define XMMMATCH xmm16
# define YMMMATCH ymm16
# define YMM1 ymm17
@@ -44,6 +58,8 @@
# define YMM6 ymm22
# define VEC_SIZE 32
+# define CHAR_PER_VEC (VEC_SIZE / CHAR_SIZE)
+# define PAGE_SIZE 4096
.section .text.evex,"ax",@progbits
ENTRY (MEMCHR)
@@ -51,11 +67,7 @@ ENTRY (MEMCHR)
/* Check for zero length. */
test %RDX_LP, %RDX_LP
jz L(zero)
-# endif
- movl %edi, %ecx
-# ifdef USE_AS_WMEMCHR
- shl $2, %RDX_LP
-# else
+
# ifdef __ILP32__
/* Clear the upper 32 bits. */
movl %edx, %edx
@@ -64,318 +76,403 @@ ENTRY (MEMCHR)
/* Broadcast CHAR to YMMMATCH. */
VPBROADCAST %esi, %YMMMATCH
/* Check if we may cross page boundary with one vector load. */
- andl $(2 * VEC_SIZE - 1), %ecx
- cmpl $VEC_SIZE, %ecx
- ja L(cros_page_boundary)
+ movl %edi, %eax
+ andl $(PAGE_SIZE - 1), %eax
+ cmpl $(PAGE_SIZE - VEC_SIZE), %eax
+ ja L(cross_page_boundary)
/* Check the first VEC_SIZE bytes. */
- VPCMP $0, (%rdi), %YMMMATCH, %k1
- kmovd %k1, %eax
- testl %eax, %eax
-
+ VPCMP $0, (%rdi), %YMMMATCH, %k0
+ kmovd %k0, %eax
# ifndef USE_AS_RAWMEMCHR
- jnz L(first_vec_x0_check)
- /* Adjust length and check the end of data. */
- subq $VEC_SIZE, %rdx
- jbe L(zero)
+ /* If length < CHAR_PER_VEC handle special. */
+ cmpq $CHAR_PER_VEC, %rdx
+ jbe L(first_vec_x0)
+# endif
+ testl %eax, %eax
+ jz L(aligned_more)
+ tzcntl %eax, %eax
+# ifdef USE_AS_WMEMCHR
+ /* NB: Multiply bytes by CHAR_SIZE to get the wchar_t count. */
+ leaq (%rdi, %rax, CHAR_SIZE), %rax
# else
- jnz L(first_vec_x0)
+ addq %rdi, %rax
# endif
-
- /* Align data for aligned loads in the loop. */
- addq $VEC_SIZE, %rdi
- andl $(VEC_SIZE - 1), %ecx
- andq $-VEC_SIZE, %rdi
+ ret
# ifndef USE_AS_RAWMEMCHR
- /* Adjust length. */
- addq %rcx, %rdx
-
- subq $(VEC_SIZE * 4), %rdx
- jbe L(last_4x_vec_or_less)
-# endif
- jmp L(more_4x_vec)
+L(zero):
+ xorl %eax, %eax
+ ret
+ .p2align 5
+L(first_vec_x0):
+ /* Check if first match was before length. */
+ tzcntl %eax, %eax
+ xorl %ecx, %ecx
+ cmpl %eax, %edx
+ leaq (%rdi, %rax, CHAR_SIZE), %rax
+ cmovle %rcx, %rax
+ ret
+# else
+ /* NB: first_vec_x0 is 17 bytes which will leave
+ cross_page_boundary (which is relatively cold) close enough
+ to ideal alignment. So only realign L(cross_page_boundary) if
+ rawmemchr. */
.p2align 4
-L(cros_page_boundary):
- andl $(VEC_SIZE - 1), %ecx
+# endif
+L(cross_page_boundary):
+ /* Save pointer before aligning as its original value is
+ necessary for computer return address if byte is found or
+ adjusting length if it is not and this is memchr. */
+ movq %rdi, %rcx
+ /* Align data to VEC_SIZE. ALGN_PTR_REG is rcx for memchr and rdi
+ for rawmemchr. */
+ andq $-VEC_SIZE, %ALGN_PTR_REG
+ VPCMP $0, (%ALGN_PTR_REG), %YMMMATCH, %k0
+ kmovd %k0, %r8d
# ifdef USE_AS_WMEMCHR
- /* NB: Divide shift count by 4 since each bit in K1 represent 4
+ /* NB: Divide shift count by 4 since each bit in K0 represent 4
bytes. */
- movl %ecx, %SHIFT_REG
- sarl $2, %SHIFT_REG
+ sarl $2, %eax
+# endif
+# ifndef USE_AS_RAWMEMCHR
+ movl $(PAGE_SIZE / CHAR_SIZE), %esi
+ subl %eax, %esi
# endif
- andq $-VEC_SIZE, %rdi
- VPCMP $0, (%rdi), %YMMMATCH, %k1
- kmovd %k1, %eax
- /* Remove the leading bytes. */
- sarxl %SHIFT_REG, %eax, %eax
- testl %eax, %eax
- jz L(aligned_more)
- tzcntl %eax, %eax
# ifdef USE_AS_WMEMCHR
- /* NB: Multiply wchar_t count by 4 to get the number of bytes. */
- sall $2, %eax
+ andl $(CHAR_PER_VEC - 1), %eax
# endif
+ /* Remove the leading bytes. */
+ sarxl %eax, %r8d, %eax
# ifndef USE_AS_RAWMEMCHR
/* Check the end of data. */
- cmpq %rax, %rdx
- jbe L(zero)
+ cmpq %rsi, %rdx
+ jbe L(first_vec_x0)
+# endif
+ testl %eax, %eax
+ jz L(cross_page_continue)
+ tzcntl %eax, %eax
+# ifdef USE_AS_WMEMCHR
+ /* NB: Multiply bytes by CHAR_SIZE to get the wchar_t count. */
+ leaq (%RAW_PTR_REG, %rax, CHAR_SIZE), %rax
+# else
+ addq %RAW_PTR_REG, %rax
# endif
- addq %rdi, %rax
- addq %rcx, %rax
ret
.p2align 4
-L(aligned_more):
-# ifndef USE_AS_RAWMEMCHR
- /* Calculate "rdx + rcx - VEC_SIZE" with "rdx - (VEC_SIZE - rcx)"
- instead of "(rdx + rcx) - VEC_SIZE" to void possible addition
- overflow. */
- negq %rcx
- addq $VEC_SIZE, %rcx
+L(first_vec_x1):
+ tzcntl %eax, %eax
+ leaq VEC_SIZE(%rdi, %rax, CHAR_SIZE), %rax
+ ret
- /* Check the end of data. */
- subq %rcx, %rdx
- jbe L(zero)
-# endif
+ .p2align 4
+L(first_vec_x2):
+ tzcntl %eax, %eax
+ leaq (VEC_SIZE * 2)(%rdi, %rax, CHAR_SIZE), %rax
+ ret
- addq $VEC_SIZE, %rdi
+ .p2align 4
+L(first_vec_x3):
+ tzcntl %eax, %eax
+ leaq (VEC_SIZE * 3)(%rdi, %rax, CHAR_SIZE), %rax
+ ret
-# ifndef USE_AS_RAWMEMCHR
- subq $(VEC_SIZE * 4), %rdx
- jbe L(last_4x_vec_or_less)
-# endif
+ .p2align 4
+L(first_vec_x4):
+ tzcntl %eax, %eax
+ leaq (VEC_SIZE * 4)(%rdi, %rax, CHAR_SIZE), %rax
+ ret
-L(more_4x_vec):
+ .p2align 5
+L(aligned_more):
/* Check the first 4 * VEC_SIZE. Only one VEC_SIZE at a time
since data is only aligned to VEC_SIZE. */
- VPCMP $0, (%rdi), %YMMMATCH, %k1
- kmovd %k1, %eax
- testl %eax, %eax
- jnz L(first_vec_x0)
- VPCMP $0, VEC_SIZE(%rdi), %YMMMATCH, %k1
- kmovd %k1, %eax
+# ifndef USE_AS_RAWMEMCHR
+ /* Align data to VEC_SIZE. */
+L(cross_page_continue):
+ xorl %ecx, %ecx
+ subl %edi, %ecx
+ andq $-VEC_SIZE, %rdi
+ /* esi is for adjusting length to see if near the end. */
+ leal (VEC_SIZE * 5)(%rdi, %rcx), %esi
+# ifdef USE_AS_WMEMCHR
+ /* NB: Divide bytes by 4 to get the wchar_t count. */
+ sarl $2, %esi
+# endif
+# else
+ andq $-VEC_SIZE, %rdi
+L(cross_page_continue):
+# endif
+ /* Load first VEC regardless. */
+ VPCMP $0, (VEC_SIZE)(%rdi), %YMMMATCH, %k0
+ kmovd %k0, %eax
+# ifndef USE_AS_RAWMEMCHR
+ /* Adjust length. If near end handle specially. */
+ subq %rsi, %rdx
+ jbe L(last_4x_vec_or_less)
+# endif
testl %eax, %eax
jnz L(first_vec_x1)
- VPCMP $0, (VEC_SIZE * 2)(%rdi), %YMMMATCH, %k1
- kmovd %k1, %eax
+ VPCMP $0, (VEC_SIZE * 2)(%rdi), %YMMMATCH, %k0
+ kmovd %k0, %eax
testl %eax, %eax
jnz L(first_vec_x2)
- VPCMP $0, (VEC_SIZE * 3)(%rdi), %YMMMATCH, %k1
- kmovd %k1, %eax
+ VPCMP $0, (VEC_SIZE * 3)(%rdi), %YMMMATCH, %k0
+ kmovd %k0, %eax
testl %eax, %eax
jnz L(first_vec_x3)
- addq $(VEC_SIZE * 4), %rdi
+ VPCMP $0, (VEC_SIZE * 4)(%rdi), %YMMMATCH, %k0
+ kmovd %k0, %eax
+ testl %eax, %eax
+ jnz L(first_vec_x4)
+
# ifndef USE_AS_RAWMEMCHR
- subq $(VEC_SIZE * 4), %rdx
- jbe L(last_4x_vec_or_less)
-# endif
+ /* Check if at last CHAR_PER_VEC * 4 length. */
+ subq $(CHAR_PER_VEC * 4), %rdx
+ jbe L(last_4x_vec_or_less_cmpeq)
+ addq $VEC_SIZE, %rdi
- /* Align data to 4 * VEC_SIZE. */
- movq %rdi, %rcx
- andl $(4 * VEC_SIZE - 1), %ecx
+ /* Align data to VEC_SIZE * 4 for the loop and readjust length.
+ */
+# ifdef USE_AS_WMEMCHR
+ movl %edi, %ecx
andq $-(4 * VEC_SIZE), %rdi
-
-# ifndef USE_AS_RAWMEMCHR
- /* Adjust length. */
+ andl $(VEC_SIZE * 4 - 1), %ecx
+ /* NB: Divide bytes by 4 to get the wchar_t count. */
+ sarl $2, %ecx
addq %rcx, %rdx
+# else
+ addq %rdi, %rdx
+ andq $-(4 * VEC_SIZE), %rdi
+ subq %rdi, %rdx
+# endif
+# else
+ addq $VEC_SIZE, %rdi
+ andq $-(4 * VEC_SIZE), %rdi
# endif
+ vpxorq %XMMZERO, %XMMZERO, %XMMZERO
+
+ /* Compare 4 * VEC at a time forward. */
.p2align 4
L(loop_4x_vec):
- /* Compare 4 * VEC at a time forward. */
- VPCMP $0, (%rdi), %YMMMATCH, %k1
- VPCMP $0, VEC_SIZE(%rdi), %YMMMATCH, %k2
- kord %k1, %k2, %k5
- VPCMP $0, (VEC_SIZE * 2)(%rdi), %YMMMATCH, %k3
- VPCMP $0, (VEC_SIZE * 3)(%rdi), %YMMMATCH, %k4
-
- kord %k3, %k4, %k6
- kortestd %k5, %k6
- jnz L(4x_vec_end)
-
- addq $(VEC_SIZE * 4), %rdi
-
+ /* It would be possible to save some instructions using 4x VPCMP
+ but bottleneck on port 5 makes it not woth it. */
+ VPCMP $4, (VEC_SIZE * 4)(%rdi), %YMMMATCH, %k1
+ /* xor will set bytes match esi to zero. */
+ vpxorq (VEC_SIZE * 5)(%rdi), %YMMMATCH, %YMM2
+ vpxorq (VEC_SIZE * 6)(%rdi), %YMMMATCH, %YMM3
+ VPCMP $0, (VEC_SIZE * 7)(%rdi), %YMMMATCH, %k3
+ /* Reduce VEC2 / VEC3 with min and VEC1 with zero mask. */
+ VPMINU %YMM2, %YMM3, %YMM3 {%k1} {z}
+ VPCMP $0, %YMM3, %YMMZERO, %k2
# ifdef USE_AS_RAWMEMCHR
- jmp L(loop_4x_vec)
+ subq $-(VEC_SIZE * 4), %rdi
+ kortestd %k2, %k3
+ jz L(loop_4x_vec)
# else
- subq $(VEC_SIZE * 4), %rdx
+ kortestd %k2, %k3
+ jnz L(loop_4x_vec_end)
+
+ subq $-(VEC_SIZE * 4), %rdi
+
+ subq $(CHAR_PER_VEC * 4), %rdx
ja L(loop_4x_vec)
+ /* Fall through into less than 4 remaining vectors of length case.
+ */
+ VPCMP $0, (VEC_SIZE * 4)(%rdi), %YMMMATCH, %k0
+ kmovd %k0, %eax
+ addq $(VEC_SIZE * 3), %rdi
+ .p2align 4
L(last_4x_vec_or_less):
- /* Less than 4 * VEC and aligned to VEC_SIZE. */
- addl $(VEC_SIZE * 2), %edx
- jle L(last_2x_vec)
-
- VPCMP $0, (%rdi), %YMMMATCH, %k1
- kmovd %k1, %eax
+ /* Check if first VEC contained match. */
testl %eax, %eax
- jnz L(first_vec_x0)
+ jnz L(first_vec_x1_check)
- VPCMP $0, VEC_SIZE(%rdi), %YMMMATCH, %k1
- kmovd %k1, %eax
- testl %eax, %eax
- jnz L(first_vec_x1)
+ /* If remaining length > CHAR_PER_VEC * 2. */
+ addl $(CHAR_PER_VEC * 2), %edx
+ jg L(last_4x_vec)
- VPCMP $0, (VEC_SIZE * 2)(%rdi), %YMMMATCH, %k1
- kmovd %k1, %eax
- testl %eax, %eax
+L(last_2x_vec):
+ /* If remaining length < CHAR_PER_VEC. */
+ addl $CHAR_PER_VEC, %edx
+ jle L(zero_end)
- jnz L(first_vec_x2_check)
- subl $VEC_SIZE, %edx
- jle L(zero)
+ /* Check VEC2 and compare any match with remaining length. */
+ VPCMP $0, (VEC_SIZE * 2)(%rdi), %YMMMATCH, %k0
+ kmovd %k0, %eax
+ tzcntl %eax, %eax
+ cmpl %eax, %edx
+ jbe L(set_zero_end)
+ leaq (VEC_SIZE * 2)(%rdi, %rax, CHAR_SIZE), %rax
+L(zero_end):
+ ret
- VPCMP $0, (VEC_SIZE * 3)(%rdi), %YMMMATCH, %k1
- kmovd %k1, %eax
- testl %eax, %eax
- jnz L(first_vec_x3_check)
+ .p2align 4
+L(first_vec_x1_check):
+ tzcntl %eax, %eax
+ /* Adjust length. */
+ subl $-(CHAR_PER_VEC * 4), %edx
+ /* Check if match within remaining length. */
+ cmpl %eax, %edx
+ jbe L(set_zero_end)
+ /* NB: Multiply bytes by CHAR_SIZE to get the wchar_t count. */
+ leaq VEC_SIZE(%rdi, %rax, CHAR_SIZE), %rax
+ ret
+L(set_zero_end):
xorl %eax, %eax
ret
.p2align 4
-L(last_2x_vec):
- addl $(VEC_SIZE * 2), %edx
- VPCMP $0, (%rdi), %YMMMATCH, %k1
+L(loop_4x_vec_end):
+# endif
+ /* rawmemchr will fall through into this if match was found in
+ loop. */
+
+ /* k1 has not of matches with VEC1. */
kmovd %k1, %eax
- testl %eax, %eax
+# ifdef USE_AS_WMEMCHR
+ subl $((1 << CHAR_PER_VEC) - 1), %eax
+# else
+ incl %eax
+# endif
+ jnz L(last_vec_x1_return)
- jnz L(first_vec_x0_check)
- subl $VEC_SIZE, %edx
- jle L(zero)
+ VPCMP $0, %YMM2, %YMMZERO, %k0
+ kmovd %k0, %eax
+ testl %eax, %eax
+ jnz L(last_vec_x2_return)
- VPCMP $0, VEC_SIZE(%rdi), %YMMMATCH, %k1
- kmovd %k1, %eax
+ kmovd %k2, %eax
testl %eax, %eax
- jnz L(first_vec_x1_check)
- xorl %eax, %eax
- ret
+ jnz L(last_vec_x3_return)
- .p2align 4
-L(first_vec_x0_check):
+ kmovd %k3, %eax
tzcntl %eax, %eax
-# ifdef USE_AS_WMEMCHR
- /* NB: Multiply wchar_t count by 4 to get the number of bytes. */
- sall $2, %eax
+# ifdef USE_AS_RAWMEMCHR
+ leaq (VEC_SIZE * 3)(%rdi, %rax, CHAR_SIZE), %rax
+# else
+ leaq (VEC_SIZE * 7)(%rdi, %rax, CHAR_SIZE), %rax
# endif
- /* Check the end of data. */
- cmpq %rax, %rdx
- jbe L(zero)
- addq %rdi, %rax
ret
.p2align 4
-L(first_vec_x1_check):
+L(last_vec_x1_return):
tzcntl %eax, %eax
-# ifdef USE_AS_WMEMCHR
- /* NB: Multiply wchar_t count by 4 to get the number of bytes. */
- sall $2, %eax
-# endif
- /* Check the end of data. */
- cmpq %rax, %rdx
- jbe L(zero)
- addq $VEC_SIZE, %rax
+# ifdef USE_AS_RAWMEMCHR
+# ifdef USE_AS_WMEMCHR
+ /* NB: Multiply bytes by CHAR_SIZE to get the wchar_t count. */
+ leaq (%rdi, %rax, CHAR_SIZE), %rax
+# else
addq %rdi, %rax
- ret
-
- .p2align 4
-L(first_vec_x2_check):
- tzcntl %eax, %eax
-# ifdef USE_AS_WMEMCHR
- /* NB: Multiply wchar_t count by 4 to get the number of bytes. */
- sall $2, %eax
+# endif
+# else
+ /* NB: Multiply bytes by CHAR_SIZE to get the wchar_t count. */
+ leaq (VEC_SIZE * 4)(%rdi, %rax, CHAR_SIZE), %rax
# endif
- /* Check the end of data. */
- cmpq %rax, %rdx
- jbe L(zero)
- addq $(VEC_SIZE * 2), %rax
- addq %rdi, %rax
ret
.p2align 4
-L(first_vec_x3_check):
+L(last_vec_x2_return):
tzcntl %eax, %eax
-# ifdef USE_AS_WMEMCHR
- /* NB: Multiply wchar_t count by 4 to get the number of bytes. */
- sall $2, %eax
+# ifdef USE_AS_RAWMEMCHR
+ /* NB: Multiply bytes by CHAR_SIZE to get the wchar_t count. */
+ leaq VEC_SIZE(%rdi, %rax, CHAR_SIZE), %rax
+# else
+ /* NB: Multiply bytes by CHAR_SIZE to get the wchar_t count. */
+ leaq (VEC_SIZE * 5)(%rdi, %rax, CHAR_SIZE), %rax
# endif
- /* Check the end of data. */
- cmpq %rax, %rdx
- jbe L(zero)
- addq $(VEC_SIZE * 3), %rax
- addq %rdi, %rax
ret
.p2align 4
-L(zero):
- xorl %eax, %eax
- ret
-# endif
-
- .p2align 4
-L(first_vec_x0):
+L(last_vec_x3_return):
tzcntl %eax, %eax
-# ifdef USE_AS_WMEMCHR
- /* NB: Multiply wchar_t count by 4 to get the number of bytes. */
- leaq (%rdi, %rax, 4), %rax
+# ifdef USE_AS_RAWMEMCHR
+ /* NB: Multiply bytes by CHAR_SIZE to get the wchar_t count. */
+ leaq (VEC_SIZE * 2)(%rdi, %rax, CHAR_SIZE), %rax
# else
- addq %rdi, %rax
+ /* NB: Multiply bytes by CHAR_SIZE to get the wchar_t count. */
+ leaq (VEC_SIZE * 6)(%rdi, %rax, CHAR_SIZE), %rax
# endif
ret
+
+# ifndef USE_AS_RAWMEMCHR
+L(last_4x_vec_or_less_cmpeq):
+ VPCMP $0, (VEC_SIZE * 5)(%rdi), %YMMMATCH, %k0
+ kmovd %k0, %eax
+ subq $-(VEC_SIZE * 4), %rdi
+ /* Check first VEC regardless. */
+ testl %eax, %eax
+ jnz L(first_vec_x1_check)
+
+ /* If remaining length <= CHAR_PER_VEC * 2. */
+ addl $(CHAR_PER_VEC * 2), %edx
+ jle L(last_2x_vec)
+
.p2align 4
-L(first_vec_x1):
+L(last_4x_vec):
+ VPCMP $0, (VEC_SIZE * 2)(%rdi), %YMMMATCH, %k0
+ kmovd %k0, %eax
+ testl %eax, %eax
+ jnz L(last_vec_x2)
+
+
+ VPCMP $0, (VEC_SIZE * 3)(%rdi), %YMMMATCH, %k0
+ kmovd %k0, %eax
+ /* Create mask for possible matches within remaining length. */
+# ifdef USE_AS_WMEMCHR
+ movl $((1 << (CHAR_PER_VEC * 2)) - 1), %ecx
+ bzhil %edx, %ecx, %ecx
+# else
+ movq $-1, %rcx
+ bzhiq %rdx, %rcx, %rcx
+# endif
+ /* Test matches in data against length match. */
+ andl %ecx, %eax
+ jnz L(last_vec_x3)
+
+ /* if remaining length <= CHAR_PER_VEC * 3 (Note this is after
+ remaining length was found to be > CHAR_PER_VEC * 2. */
+ subl $CHAR_PER_VEC, %edx
+ jbe L(zero_end2)
+
+
+ VPCMP $0, (VEC_SIZE * 4)(%rdi), %YMMMATCH, %k0
+ kmovd %k0, %eax
+ /* Shift remaining length mask for last VEC. */
+# ifdef USE_AS_WMEMCHR
+ shrl $CHAR_PER_VEC, %ecx
+# else
+ shrq $CHAR_PER_VEC, %rcx
+# endif
+ andl %ecx, %eax
+ jz L(zero_end2)
tzcntl %eax, %eax
-# ifdef USE_AS_WMEMCHR
- /* NB: Multiply wchar_t count by 4 to get the number of bytes. */
- leaq VEC_SIZE(%rdi, %rax, 4), %rax
-# else
- addq $VEC_SIZE, %rax
- addq %rdi, %rax
-# endif
+ leaq (VEC_SIZE * 4)(%rdi, %rax, CHAR_SIZE), %rax
+L(zero_end2):
ret
- .p2align 4
-L(first_vec_x2):
+L(last_vec_x2):
tzcntl %eax, %eax
-# ifdef USE_AS_WMEMCHR
- /* NB: Multiply wchar_t count by 4 to get the number of bytes. */
- leaq (VEC_SIZE * 2)(%rdi, %rax, 4), %rax
-# else
- addq $(VEC_SIZE * 2), %rax
- addq %rdi, %rax
-# endif
+ leaq (VEC_SIZE * 2)(%rdi, %rax, CHAR_SIZE), %rax
ret
.p2align 4
-L(4x_vec_end):
- kmovd %k1, %eax
- testl %eax, %eax
- jnz L(first_vec_x0)
- kmovd %k2, %eax
- testl %eax, %eax
- jnz L(first_vec_x1)
- kmovd %k3, %eax
- testl %eax, %eax
- jnz L(first_vec_x2)
- kmovd %k4, %eax
- testl %eax, %eax
-L(first_vec_x3):
+L(last_vec_x3):
tzcntl %eax, %eax
-# ifdef USE_AS_WMEMCHR
- /* NB: Multiply wchar_t count by 4 to get the number of bytes. */
- leaq (VEC_SIZE * 3)(%rdi, %rax, 4), %rax
-# else
- addq $(VEC_SIZE * 3), %rax
- addq %rdi, %rax
-# endif
+ leaq (VEC_SIZE * 3)(%rdi, %rax, CHAR_SIZE), %rax
ret
+# endif
END (MEMCHR)
#endif
--
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