329e925ee9
Upstream commit: 91c2e6c3db44297bf4cb3a2e3c40236c5b6a0b23 - dlfcn: Implement the RTLD_DI_PHDR request type for dlinfo - manual: Document the dlinfo function - x86: Fix fallback for wcsncmp_avx2 in strcmp-avx2.S [BZ #28896] - x86: Fix bug in strncmp-evex and strncmp-avx2 [BZ #28895] - x86: Set .text section in memset-vec-unaligned-erms - x86-64: Optimize bzero - x86: Remove SSSE3 instruction for broadcast in memset.S (SSE2 Only) - x86: Improve vec generation in memset-vec-unaligned-erms.S - x86-64: Fix strcmp-evex.S - x86-64: Fix strcmp-avx2.S - x86: Optimize strcmp-evex.S - x86: Optimize strcmp-avx2.S - manual: Clarify that abbreviations of long options are allowed - Add HWCAP2_AFP, HWCAP2_RPRES from Linux 5.17 to AArch64 bits/hwcap.h - aarch64: Add HWCAP2_ECV from Linux 5.16 - Add SOL_MPTCP, SOL_MCTP from Linux 5.16 to bits/socket.h - Update kernel version to 5.17 in tst-mman-consts.py - Update kernel version to 5.16 in tst-mman-consts.py - Update syscall lists for Linux 5.17 - Add ARPHRD_CAN, ARPHRD_MCTP to net/if_arp.h - Update kernel version to 5.15 in tst-mman-consts.py - Add PF_MCTP, AF_MCTP from Linux 5.15 to bits/socket.h
1988 lines
50 KiB
Diff
1988 lines
50 KiB
Diff
commit c41a66767d23b7f219fb943be6fab5ddf822d7da
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Author: Noah Goldstein <goldstein.w.n@gmail.com>
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Date: Mon Jan 10 15:35:39 2022 -0600
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x86: Optimize strcmp-evex.S
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Optimization are primarily to the loop logic and how the page cross
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logic interacts with the loop.
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The page cross logic is at times more expensive for short strings near
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the end of a page but not crossing the page. This is done to retest
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the page cross conditions with a non-faulty check and to improve the
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logic for entering the loop afterwards. This is only particular cases,
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however, and is general made up for by more than 10x improvements on
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the transition from the page cross -> loop case.
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The non-page cross cases as well are nearly universally improved.
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test-strcmp, test-strncmp, test-wcscmp, and test-wcsncmp all pass.
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Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com>
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(cherry picked from commit 8418eb3ff4b781d31c4ed5dc6c0bd7356bc45db9)
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diff --git a/sysdeps/x86_64/multiarch/strcmp-evex.S b/sysdeps/x86_64/multiarch/strcmp-evex.S
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index 6f5c4bf984da2b80..99d8409af27327ad 100644
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--- a/sysdeps/x86_64/multiarch/strcmp-evex.S
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+++ b/sysdeps/x86_64/multiarch/strcmp-evex.S
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@@ -26,54 +26,69 @@
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# define PAGE_SIZE 4096
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-/* VEC_SIZE = Number of bytes in a ymm register */
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+ /* VEC_SIZE = Number of bytes in a ymm register. */
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# define VEC_SIZE 32
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+# define CHAR_PER_VEC (VEC_SIZE / SIZE_OF_CHAR)
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-/* Shift for dividing by (VEC_SIZE * 4). */
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-# define DIVIDE_BY_VEC_4_SHIFT 7
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-# if (VEC_SIZE * 4) != (1 << DIVIDE_BY_VEC_4_SHIFT)
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-# error (VEC_SIZE * 4) != (1 << DIVIDE_BY_VEC_4_SHIFT)
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-# endif
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-
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-# define VMOVU vmovdqu64
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-# define VMOVA vmovdqa64
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+# define VMOVU vmovdqu64
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+# define VMOVA vmovdqa64
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# ifdef USE_AS_WCSCMP
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-/* Compare packed dwords. */
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-# define VPCMP vpcmpd
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+# define TESTEQ subl $0xff,
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+ /* Compare packed dwords. */
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+# define VPCMP vpcmpd
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# define VPMINU vpminud
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# define VPTESTM vptestmd
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-# define SHIFT_REG32 r8d
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-# define SHIFT_REG64 r8
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-/* 1 dword char == 4 bytes. */
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+ /* 1 dword char == 4 bytes. */
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# define SIZE_OF_CHAR 4
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# else
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-/* Compare packed bytes. */
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-# define VPCMP vpcmpb
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+# define TESTEQ incl
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+ /* Compare packed bytes. */
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+# define VPCMP vpcmpb
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# define VPMINU vpminub
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# define VPTESTM vptestmb
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-# define SHIFT_REG32 ecx
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-# define SHIFT_REG64 rcx
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-/* 1 byte char == 1 byte. */
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+ /* 1 byte char == 1 byte. */
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# define SIZE_OF_CHAR 1
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# endif
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+# ifdef USE_AS_STRNCMP
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+# define LOOP_REG r9d
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+# define LOOP_REG64 r9
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+
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+# define OFFSET_REG8 r9b
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+# define OFFSET_REG r9d
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+# define OFFSET_REG64 r9
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+# else
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+# define LOOP_REG edx
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+# define LOOP_REG64 rdx
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+
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+# define OFFSET_REG8 dl
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+# define OFFSET_REG edx
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+# define OFFSET_REG64 rdx
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+# endif
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+
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+# if defined USE_AS_STRNCMP || defined USE_AS_WCSCMP
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+# define VEC_OFFSET 0
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+# else
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+# define VEC_OFFSET (-VEC_SIZE)
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+# endif
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+
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# define XMMZERO xmm16
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-# define XMM0 xmm17
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-# define XMM1 xmm18
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+# define XMM0 xmm17
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+# define XMM1 xmm18
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# define YMMZERO ymm16
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-# define YMM0 ymm17
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-# define YMM1 ymm18
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-# define YMM2 ymm19
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-# define YMM3 ymm20
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-# define YMM4 ymm21
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-# define YMM5 ymm22
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-# define YMM6 ymm23
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-# define YMM7 ymm24
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-# define YMM8 ymm25
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-# define YMM9 ymm26
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-# define YMM10 ymm27
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+# define YMM0 ymm17
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+# define YMM1 ymm18
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+# define YMM2 ymm19
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+# define YMM3 ymm20
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+# define YMM4 ymm21
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+# define YMM5 ymm22
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+# define YMM6 ymm23
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+# define YMM7 ymm24
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+# define YMM8 ymm25
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+# define YMM9 ymm26
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+# define YMM10 ymm27
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/* Warning!
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wcscmp/wcsncmp have to use SIGNED comparison for elements.
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@@ -96,985 +111,1096 @@
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the maximum offset is reached before a difference is found, zero is
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returned. */
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- .section .text.evex,"ax",@progbits
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-ENTRY (STRCMP)
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+ .section .text.evex, "ax", @progbits
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+ENTRY(STRCMP)
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# ifdef USE_AS_STRNCMP
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- /* Check for simple cases (0 or 1) in offset. */
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- cmp $1, %RDX_LP
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- je L(char0)
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- jb L(zero)
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-# ifdef USE_AS_WCSCMP
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-# ifndef __ILP32__
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- movq %rdx, %rcx
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- /* Check if length could overflow when multiplied by
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- sizeof(wchar_t). Checking top 8 bits will cover all potential
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- overflow cases as well as redirect cases where its impossible to
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- length to bound a valid memory region. In these cases just use
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- 'wcscmp'. */
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- shrq $56, %rcx
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- jnz __wcscmp_evex
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-# endif
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- /* Convert units: from wide to byte char. */
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- shl $2, %RDX_LP
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+# ifdef __ILP32__
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+ /* Clear the upper 32 bits. */
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+ movl %edx, %rdx
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# endif
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- /* Register %r11 tracks the maximum offset. */
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- mov %RDX_LP, %R11_LP
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+ cmp $1, %RDX_LP
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+ /* Signed comparison intentional. We use this branch to also
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+ test cases where length >= 2^63. These very large sizes can be
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+ handled with strcmp as there is no way for that length to
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+ actually bound the buffer. */
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+ jle L(one_or_less)
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# endif
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movl %edi, %eax
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- xorl %edx, %edx
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- /* Make %XMMZERO (%YMMZERO) all zeros in this function. */
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- vpxorq %XMMZERO, %XMMZERO, %XMMZERO
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orl %esi, %eax
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- andl $(PAGE_SIZE - 1), %eax
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- cmpl $(PAGE_SIZE - (VEC_SIZE * 4)), %eax
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- jg L(cross_page)
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- /* Start comparing 4 vectors. */
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+ /* Shift out the bits irrelivant to page boundary ([63:12]). */
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+ sall $20, %eax
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+ /* Check if s1 or s2 may cross a page in next 4x VEC loads. */
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+ cmpl $((PAGE_SIZE -(VEC_SIZE * 4)) << 20), %eax
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+ ja L(page_cross)
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+
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+L(no_page_cross):
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+ /* Safe to compare 4x vectors. */
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VMOVU (%rdi), %YMM0
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-
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- /* Each bit set in K2 represents a non-null CHAR in YMM0. */
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VPTESTM %YMM0, %YMM0, %k2
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-
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/* Each bit cleared in K1 represents a mismatch or a null CHAR
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in YMM0 and 32 bytes at (%rsi). */
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VPCMP $0, (%rsi), %YMM0, %k1{%k2}
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-
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kmovd %k1, %ecx
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-# ifdef USE_AS_WCSCMP
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- subl $0xff, %ecx
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-# else
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- incl %ecx
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-# endif
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- je L(next_3_vectors)
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- tzcntl %ecx, %edx
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-# ifdef USE_AS_WCSCMP
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- /* NB: Multiply wchar_t count by 4 to get the number of bytes. */
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- sall $2, %edx
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-# endif
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# ifdef USE_AS_STRNCMP
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- /* Return 0 if the mismatched index (%rdx) is after the maximum
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- offset (%r11). */
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- cmpq %r11, %rdx
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- jae L(zero)
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+ cmpq $CHAR_PER_VEC, %rdx
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+ jbe L(vec_0_test_len)
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# endif
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+
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+ /* TESTEQ is `incl` for strcmp/strncmp and `subl $0xff` for
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+ wcscmp/wcsncmp. */
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+
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+ /* All 1s represents all equals. TESTEQ will overflow to zero in
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+ all equals case. Otherwise 1s will carry until position of first
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+ mismatch. */
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+ TESTEQ %ecx
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+ jz L(more_3x_vec)
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+
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+ .p2align 4,, 4
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+L(return_vec_0):
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+ tzcntl %ecx, %ecx
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# ifdef USE_AS_WCSCMP
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+ movl (%rdi, %rcx, SIZE_OF_CHAR), %edx
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xorl %eax, %eax
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- movl (%rdi, %rdx), %ecx
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- cmpl (%rsi, %rdx), %ecx
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- je L(return)
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-L(wcscmp_return):
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+ cmpl (%rsi, %rcx, SIZE_OF_CHAR), %edx
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+ je L(ret0)
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setl %al
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negl %eax
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orl $1, %eax
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-L(return):
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# else
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- movzbl (%rdi, %rdx), %eax
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- movzbl (%rsi, %rdx), %edx
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- subl %edx, %eax
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+ movzbl (%rdi, %rcx), %eax
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+ movzbl (%rsi, %rcx), %ecx
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+ subl %ecx, %eax
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# endif
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+L(ret0):
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ret
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-L(return_vec_size):
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- tzcntl %ecx, %edx
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-# ifdef USE_AS_WCSCMP
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- /* NB: Multiply wchar_t count by 4 to get the number of bytes. */
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- sall $2, %edx
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-# endif
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# ifdef USE_AS_STRNCMP
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- /* Return 0 if the mismatched index (%rdx + VEC_SIZE) is after
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- the maximum offset (%r11). */
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- addq $VEC_SIZE, %rdx
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- cmpq %r11, %rdx
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- jae L(zero)
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-# ifdef USE_AS_WCSCMP
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+ .p2align 4,, 4
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+L(vec_0_test_len):
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+ notl %ecx
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+ bzhil %edx, %ecx, %eax
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+ jnz L(return_vec_0)
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+ /* Align if will cross fetch block. */
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+ .p2align 4,, 2
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+L(ret_zero):
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xorl %eax, %eax
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- movl (%rdi, %rdx), %ecx
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- cmpl (%rsi, %rdx), %ecx
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- jne L(wcscmp_return)
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-# else
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- movzbl (%rdi, %rdx), %eax
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- movzbl (%rsi, %rdx), %edx
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- subl %edx, %eax
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-# endif
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-# else
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+ ret
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+
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+ .p2align 4,, 5
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+L(one_or_less):
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+ jb L(ret_zero)
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# ifdef USE_AS_WCSCMP
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+ /* 'nbe' covers the case where length is negative (large
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+ unsigned). */
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+ jnbe __wcscmp_evex
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+ movl (%rdi), %edx
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xorl %eax, %eax
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- movl VEC_SIZE(%rdi, %rdx), %ecx
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- cmpl VEC_SIZE(%rsi, %rdx), %ecx
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- jne L(wcscmp_return)
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+ cmpl (%rsi), %edx
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+ je L(ret1)
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+ setl %al
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+ negl %eax
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+ orl $1, %eax
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# else
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- movzbl VEC_SIZE(%rdi, %rdx), %eax
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- movzbl VEC_SIZE(%rsi, %rdx), %edx
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- subl %edx, %eax
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+ /* 'nbe' covers the case where length is negative (large
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+ unsigned). */
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+ jnbe __strcmp_evex
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+ movzbl (%rdi), %eax
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+ movzbl (%rsi), %ecx
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+ subl %ecx, %eax
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# endif
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-# endif
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+L(ret1):
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ret
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+# endif
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-L(return_2_vec_size):
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- tzcntl %ecx, %edx
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+ .p2align 4,, 10
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+L(return_vec_1):
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+ tzcntl %ecx, %ecx
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+# ifdef USE_AS_STRNCMP
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+ /* rdx must be > CHAR_PER_VEC so its safe to subtract without
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+ worrying about underflow. */
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+ addq $-CHAR_PER_VEC, %rdx
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+ cmpq %rcx, %rdx
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+ jbe L(ret_zero)
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+# endif
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# ifdef USE_AS_WCSCMP
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- /* NB: Multiply wchar_t count by 4 to get the number of bytes. */
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- sall $2, %edx
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+ movl VEC_SIZE(%rdi, %rcx, SIZE_OF_CHAR), %edx
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+ xorl %eax, %eax
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+ cmpl VEC_SIZE(%rsi, %rcx, SIZE_OF_CHAR), %edx
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+ je L(ret2)
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+ setl %al
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+ negl %eax
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+ orl $1, %eax
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+# else
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+ movzbl VEC_SIZE(%rdi, %rcx), %eax
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+ movzbl VEC_SIZE(%rsi, %rcx), %ecx
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+ subl %ecx, %eax
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# endif
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+L(ret2):
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+ ret
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+
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+ .p2align 4,, 10
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# ifdef USE_AS_STRNCMP
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- /* Return 0 if the mismatched index (%rdx + 2 * VEC_SIZE) is
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- after the maximum offset (%r11). */
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- addq $(VEC_SIZE * 2), %rdx
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- cmpq %r11, %rdx
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- jae L(zero)
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-# ifdef USE_AS_WCSCMP
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- xorl %eax, %eax
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- movl (%rdi, %rdx), %ecx
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- cmpl (%rsi, %rdx), %ecx
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- jne L(wcscmp_return)
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+L(return_vec_3):
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+# if CHAR_PER_VEC <= 16
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+ sall $CHAR_PER_VEC, %ecx
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# else
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- movzbl (%rdi, %rdx), %eax
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- movzbl (%rsi, %rdx), %edx
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- subl %edx, %eax
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+ salq $CHAR_PER_VEC, %rcx
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# endif
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+# endif
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+L(return_vec_2):
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+# if (CHAR_PER_VEC <= 16) || !(defined USE_AS_STRNCMP)
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+ tzcntl %ecx, %ecx
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# else
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-# ifdef USE_AS_WCSCMP
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- xorl %eax, %eax
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- movl (VEC_SIZE * 2)(%rdi, %rdx), %ecx
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- cmpl (VEC_SIZE * 2)(%rsi, %rdx), %ecx
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- jne L(wcscmp_return)
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-# else
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- movzbl (VEC_SIZE * 2)(%rdi, %rdx), %eax
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- movzbl (VEC_SIZE * 2)(%rsi, %rdx), %edx
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- subl %edx, %eax
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-# endif
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+ tzcntq %rcx, %rcx
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# endif
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- ret
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-L(return_3_vec_size):
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- tzcntl %ecx, %edx
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-# ifdef USE_AS_WCSCMP
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- /* NB: Multiply wchar_t count by 4 to get the number of bytes. */
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- sall $2, %edx
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-# endif
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# ifdef USE_AS_STRNCMP
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- /* Return 0 if the mismatched index (%rdx + 3 * VEC_SIZE) is
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- after the maximum offset (%r11). */
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- addq $(VEC_SIZE * 3), %rdx
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- cmpq %r11, %rdx
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- jae L(zero)
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-# ifdef USE_AS_WCSCMP
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+ cmpq %rcx, %rdx
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+ jbe L(ret_zero)
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+# endif
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+
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+# ifdef USE_AS_WCSCMP
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+ movl (VEC_SIZE * 2)(%rdi, %rcx, SIZE_OF_CHAR), %edx
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xorl %eax, %eax
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- movl (%rdi, %rdx), %ecx
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- cmpl (%rsi, %rdx), %ecx
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- jne L(wcscmp_return)
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-# else
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- movzbl (%rdi, %rdx), %eax
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- movzbl (%rsi, %rdx), %edx
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- subl %edx, %eax
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-# endif
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+ cmpl (VEC_SIZE * 2)(%rsi, %rcx, SIZE_OF_CHAR), %edx
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+ je L(ret3)
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+ setl %al
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+ negl %eax
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+ orl $1, %eax
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# else
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+ movzbl (VEC_SIZE * 2)(%rdi, %rcx), %eax
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+ movzbl (VEC_SIZE * 2)(%rsi, %rcx), %ecx
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+ subl %ecx, %eax
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+# endif
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+L(ret3):
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+ ret
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+
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+# ifndef USE_AS_STRNCMP
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+ .p2align 4,, 10
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+L(return_vec_3):
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+ tzcntl %ecx, %ecx
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# ifdef USE_AS_WCSCMP
|
|
+ movl (VEC_SIZE * 3)(%rdi, %rcx, SIZE_OF_CHAR), %edx
|
|
xorl %eax, %eax
|
|
- movl (VEC_SIZE * 3)(%rdi, %rdx), %ecx
|
|
- cmpl (VEC_SIZE * 3)(%rsi, %rdx), %ecx
|
|
- jne L(wcscmp_return)
|
|
+ cmpl (VEC_SIZE * 3)(%rsi, %rcx, SIZE_OF_CHAR), %edx
|
|
+ je L(ret4)
|
|
+ setl %al
|
|
+ negl %eax
|
|
+ orl $1, %eax
|
|
# else
|
|
- movzbl (VEC_SIZE * 3)(%rdi, %rdx), %eax
|
|
- movzbl (VEC_SIZE * 3)(%rsi, %rdx), %edx
|
|
- subl %edx, %eax
|
|
+ movzbl (VEC_SIZE * 3)(%rdi, %rcx), %eax
|
|
+ movzbl (VEC_SIZE * 3)(%rsi, %rcx), %ecx
|
|
+ subl %ecx, %eax
|
|
# endif
|
|
-# endif
|
|
+L(ret4):
|
|
ret
|
|
+# endif
|
|
|
|
- .p2align 4
|
|
-L(next_3_vectors):
|
|
- VMOVU VEC_SIZE(%rdi), %YMM0
|
|
- /* Each bit set in K2 represents a non-null CHAR in YMM0. */
|
|
+ /* 32 byte align here ensures the main loop is ideally aligned
|
|
+ for DSB. */
|
|
+ .p2align 5
|
|
+L(more_3x_vec):
|
|
+ /* Safe to compare 4x vectors. */
|
|
+ VMOVU (VEC_SIZE)(%rdi), %YMM0
|
|
VPTESTM %YMM0, %YMM0, %k2
|
|
- /* Each bit cleared in K1 represents a mismatch or a null CHAR
|
|
- in YMM0 and 32 bytes at VEC_SIZE(%rsi). */
|
|
- VPCMP $0, VEC_SIZE(%rsi), %YMM0, %k1{%k2}
|
|
+ VPCMP $0, (VEC_SIZE)(%rsi), %YMM0, %k1{%k2}
|
|
kmovd %k1, %ecx
|
|
-# ifdef USE_AS_WCSCMP
|
|
- subl $0xff, %ecx
|
|
-# else
|
|
- incl %ecx
|
|
+ TESTEQ %ecx
|
|
+ jnz L(return_vec_1)
|
|
+
|
|
+# ifdef USE_AS_STRNCMP
|
|
+ subq $(CHAR_PER_VEC * 2), %rdx
|
|
+ jbe L(ret_zero)
|
|
# endif
|
|
- jne L(return_vec_size)
|
|
|
|
VMOVU (VEC_SIZE * 2)(%rdi), %YMM0
|
|
- /* Each bit set in K2 represents a non-null CHAR in YMM0. */
|
|
VPTESTM %YMM0, %YMM0, %k2
|
|
- /* Each bit cleared in K1 represents a mismatch or a null CHAR
|
|
- in YMM0 and 32 bytes at (VEC_SIZE * 2)(%rsi). */
|
|
VPCMP $0, (VEC_SIZE * 2)(%rsi), %YMM0, %k1{%k2}
|
|
kmovd %k1, %ecx
|
|
-# ifdef USE_AS_WCSCMP
|
|
- subl $0xff, %ecx
|
|
-# else
|
|
- incl %ecx
|
|
-# endif
|
|
- jne L(return_2_vec_size)
|
|
+ TESTEQ %ecx
|
|
+ jnz L(return_vec_2)
|
|
|
|
VMOVU (VEC_SIZE * 3)(%rdi), %YMM0
|
|
- /* Each bit set in K2 represents a non-null CHAR in YMM0. */
|
|
VPTESTM %YMM0, %YMM0, %k2
|
|
- /* Each bit cleared in K1 represents a mismatch or a null CHAR
|
|
- in YMM0 and 32 bytes at (VEC_SIZE * 2)(%rsi). */
|
|
VPCMP $0, (VEC_SIZE * 3)(%rsi), %YMM0, %k1{%k2}
|
|
kmovd %k1, %ecx
|
|
+ TESTEQ %ecx
|
|
+ jnz L(return_vec_3)
|
|
+
|
|
+# ifdef USE_AS_STRNCMP
|
|
+ cmpq $(CHAR_PER_VEC * 2), %rdx
|
|
+ jbe L(ret_zero)
|
|
+# endif
|
|
+
|
|
+
|
|
# ifdef USE_AS_WCSCMP
|
|
- subl $0xff, %ecx
|
|
+ /* any non-zero positive value that doesn't inference with 0x1.
|
|
+ */
|
|
+ movl $2, %r8d
|
|
+
|
|
# else
|
|
- incl %ecx
|
|
+ xorl %r8d, %r8d
|
|
# endif
|
|
- jne L(return_3_vec_size)
|
|
-L(main_loop_header):
|
|
- leaq (VEC_SIZE * 4)(%rdi), %rdx
|
|
- movl $PAGE_SIZE, %ecx
|
|
- /* Align load via RAX. */
|
|
- andq $-(VEC_SIZE * 4), %rdx
|
|
- subq %rdi, %rdx
|
|
- leaq (%rdi, %rdx), %rax
|
|
+
|
|
+ /* The prepare labels are various entry points from the page
|
|
+ cross logic. */
|
|
+L(prepare_loop):
|
|
+
|
|
# ifdef USE_AS_STRNCMP
|
|
- /* Starting from this point, the maximum offset, or simply the
|
|
- 'offset', DECREASES by the same amount when base pointers are
|
|
- moved forward. Return 0 when:
|
|
- 1) On match: offset <= the matched vector index.
|
|
- 2) On mistmach, offset is before the mistmatched index.
|
|
- */
|
|
- subq %rdx, %r11
|
|
- jbe L(zero)
|
|
+# ifdef USE_AS_WCSCMP
|
|
+L(prepare_loop_no_len):
|
|
+ movl %edi, %ecx
|
|
+ andl $(VEC_SIZE * 4 - 1), %ecx
|
|
+ shrl $2, %ecx
|
|
+ leaq (CHAR_PER_VEC * 2)(%rdx, %rcx), %rdx
|
|
+# else
|
|
+ /* Store N + (VEC_SIZE * 4) and place check at the begining of
|
|
+ the loop. */
|
|
+ leaq (VEC_SIZE * 2)(%rdi, %rdx), %rdx
|
|
+L(prepare_loop_no_len):
|
|
+# endif
|
|
+# else
|
|
+L(prepare_loop_no_len):
|
|
# endif
|
|
- addq %rsi, %rdx
|
|
- movq %rdx, %rsi
|
|
- andl $(PAGE_SIZE - 1), %esi
|
|
- /* Number of bytes before page crossing. */
|
|
- subq %rsi, %rcx
|
|
- /* Number of VEC_SIZE * 4 blocks before page crossing. */
|
|
- shrq $DIVIDE_BY_VEC_4_SHIFT, %rcx
|
|
- /* ESI: Number of VEC_SIZE * 4 blocks before page crossing. */
|
|
- movl %ecx, %esi
|
|
- jmp L(loop_start)
|
|
|
|
+ /* Align s1 and adjust s2 accordingly. */
|
|
+ subq %rdi, %rsi
|
|
+ andq $-(VEC_SIZE * 4), %rdi
|
|
+L(prepare_loop_readj):
|
|
+ addq %rdi, %rsi
|
|
+# if (defined USE_AS_STRNCMP) && !(defined USE_AS_WCSCMP)
|
|
+ subq %rdi, %rdx
|
|
+# endif
|
|
+
|
|
+L(prepare_loop_aligned):
|
|
+ /* eax stores distance from rsi to next page cross. These cases
|
|
+ need to be handled specially as the 4x loop could potentially
|
|
+ read memory past the length of s1 or s2 and across a page
|
|
+ boundary. */
|
|
+ movl $-(VEC_SIZE * 4), %eax
|
|
+ subl %esi, %eax
|
|
+ andl $(PAGE_SIZE - 1), %eax
|
|
+
|
|
+ vpxorq %YMMZERO, %YMMZERO, %YMMZERO
|
|
+
|
|
+ /* Loop 4x comparisons at a time. */
|
|
.p2align 4
|
|
L(loop):
|
|
+
|
|
+ /* End condition for strncmp. */
|
|
# ifdef USE_AS_STRNCMP
|
|
- /* Base pointers are moved forward by 4 * VEC_SIZE. Decrease
|
|
- the maximum offset (%r11) by the same amount. */
|
|
- subq $(VEC_SIZE * 4), %r11
|
|
- jbe L(zero)
|
|
+ subq $(CHAR_PER_VEC * 4), %rdx
|
|
+ jbe L(ret_zero)
|
|
# endif
|
|
- addq $(VEC_SIZE * 4), %rax
|
|
- addq $(VEC_SIZE * 4), %rdx
|
|
-L(loop_start):
|
|
- testl %esi, %esi
|
|
- leal -1(%esi), %esi
|
|
- je L(loop_cross_page)
|
|
-L(back_to_loop):
|
|
- /* Main loop, comparing 4 vectors are a time. */
|
|
- VMOVA (%rax), %YMM0
|
|
- VMOVA VEC_SIZE(%rax), %YMM2
|
|
- VMOVA (VEC_SIZE * 2)(%rax), %YMM4
|
|
- VMOVA (VEC_SIZE * 3)(%rax), %YMM6
|
|
+
|
|
+ subq $-(VEC_SIZE * 4), %rdi
|
|
+ subq $-(VEC_SIZE * 4), %rsi
|
|
+
|
|
+ /* Check if rsi loads will cross a page boundary. */
|
|
+ addl $-(VEC_SIZE * 4), %eax
|
|
+ jnb L(page_cross_during_loop)
|
|
+
|
|
+ /* Loop entry after handling page cross during loop. */
|
|
+L(loop_skip_page_cross_check):
|
|
+ VMOVA (VEC_SIZE * 0)(%rdi), %YMM0
|
|
+ VMOVA (VEC_SIZE * 1)(%rdi), %YMM2
|
|
+ VMOVA (VEC_SIZE * 2)(%rdi), %YMM4
|
|
+ VMOVA (VEC_SIZE * 3)(%rdi), %YMM6
|
|
|
|
VPMINU %YMM0, %YMM2, %YMM8
|
|
VPMINU %YMM4, %YMM6, %YMM9
|
|
|
|
- /* A zero CHAR in YMM8 means that there is a null CHAR. */
|
|
- VPMINU %YMM8, %YMM9, %YMM8
|
|
+ /* A zero CHAR in YMM9 means that there is a null CHAR. */
|
|
+ VPMINU %YMM8, %YMM9, %YMM9
|
|
|
|
/* Each bit set in K1 represents a non-null CHAR in YMM8. */
|
|
- VPTESTM %YMM8, %YMM8, %k1
|
|
+ VPTESTM %YMM9, %YMM9, %k1
|
|
|
|
- /* (YMM ^ YMM): A non-zero CHAR represents a mismatch. */
|
|
- vpxorq (%rdx), %YMM0, %YMM1
|
|
- vpxorq VEC_SIZE(%rdx), %YMM2, %YMM3
|
|
- vpxorq (VEC_SIZE * 2)(%rdx), %YMM4, %YMM5
|
|
- vpxorq (VEC_SIZE * 3)(%rdx), %YMM6, %YMM7
|
|
+ vpxorq (VEC_SIZE * 0)(%rsi), %YMM0, %YMM1
|
|
+ vpxorq (VEC_SIZE * 1)(%rsi), %YMM2, %YMM3
|
|
+ vpxorq (VEC_SIZE * 2)(%rsi), %YMM4, %YMM5
|
|
+ /* Ternary logic to xor (VEC_SIZE * 3)(%rsi) with YMM6 while
|
|
+ oring with YMM1. Result is stored in YMM6. */
|
|
+ vpternlogd $0xde, (VEC_SIZE * 3)(%rsi), %YMM1, %YMM6
|
|
|
|
- vporq %YMM1, %YMM3, %YMM9
|
|
- vporq %YMM5, %YMM7, %YMM10
|
|
+ /* Or together YMM3, YMM5, and YMM6. */
|
|
+ vpternlogd $0xfe, %YMM3, %YMM5, %YMM6
|
|
|
|
- /* A non-zero CHAR in YMM9 represents a mismatch. */
|
|
- vporq %YMM9, %YMM10, %YMM9
|
|
|
|
- /* Each bit cleared in K0 represents a mismatch or a null CHAR. */
|
|
- VPCMP $0, %YMMZERO, %YMM9, %k0{%k1}
|
|
- kmovd %k0, %ecx
|
|
-# ifdef USE_AS_WCSCMP
|
|
- subl $0xff, %ecx
|
|
-# else
|
|
- incl %ecx
|
|
-# endif
|
|
- je L(loop)
|
|
+ /* A non-zero CHAR in YMM6 represents a mismatch. */
|
|
+ VPCMP $0, %YMMZERO, %YMM6, %k0{%k1}
|
|
+ kmovd %k0, %LOOP_REG
|
|
|
|
- /* Each bit set in K1 represents a non-null CHAR in YMM0. */
|
|
+ TESTEQ %LOOP_REG
|
|
+ jz L(loop)
|
|
+
|
|
+
|
|
+ /* Find which VEC has the mismatch of end of string. */
|
|
VPTESTM %YMM0, %YMM0, %k1
|
|
- /* Each bit cleared in K0 represents a mismatch or a null CHAR
|
|
- in YMM0 and (%rdx). */
|
|
VPCMP $0, %YMMZERO, %YMM1, %k0{%k1}
|
|
kmovd %k0, %ecx
|
|
-# ifdef USE_AS_WCSCMP
|
|
- subl $0xff, %ecx
|
|
-# else
|
|
- incl %ecx
|
|
-# endif
|
|
- je L(test_vec)
|
|
- tzcntl %ecx, %ecx
|
|
-# ifdef USE_AS_WCSCMP
|
|
- /* NB: Multiply wchar_t count by 4 to get the number of bytes. */
|
|
- sall $2, %ecx
|
|
-# endif
|
|
-# ifdef USE_AS_STRNCMP
|
|
- cmpq %rcx, %r11
|
|
- jbe L(zero)
|
|
-# ifdef USE_AS_WCSCMP
|
|
- movq %rax, %rsi
|
|
- xorl %eax, %eax
|
|
- movl (%rsi, %rcx), %edi
|
|
- cmpl (%rdx, %rcx), %edi
|
|
- jne L(wcscmp_return)
|
|
-# else
|
|
- movzbl (%rax, %rcx), %eax
|
|
- movzbl (%rdx, %rcx), %edx
|
|
- subl %edx, %eax
|
|
-# endif
|
|
-# else
|
|
-# ifdef USE_AS_WCSCMP
|
|
- movq %rax, %rsi
|
|
- xorl %eax, %eax
|
|
- movl (%rsi, %rcx), %edi
|
|
- cmpl (%rdx, %rcx), %edi
|
|
- jne L(wcscmp_return)
|
|
-# else
|
|
- movzbl (%rax, %rcx), %eax
|
|
- movzbl (%rdx, %rcx), %edx
|
|
- subl %edx, %eax
|
|
-# endif
|
|
-# endif
|
|
- ret
|
|
+ TESTEQ %ecx
|
|
+ jnz L(return_vec_0_end)
|
|
|
|
- .p2align 4
|
|
-L(test_vec):
|
|
-# ifdef USE_AS_STRNCMP
|
|
- /* The first vector matched. Return 0 if the maximum offset
|
|
- (%r11) <= VEC_SIZE. */
|
|
- cmpq $VEC_SIZE, %r11
|
|
- jbe L(zero)
|
|
-# endif
|
|
- /* Each bit set in K1 represents a non-null CHAR in YMM2. */
|
|
VPTESTM %YMM2, %YMM2, %k1
|
|
- /* Each bit cleared in K0 represents a mismatch or a null CHAR
|
|
- in YMM2 and VEC_SIZE(%rdx). */
|
|
VPCMP $0, %YMMZERO, %YMM3, %k0{%k1}
|
|
kmovd %k0, %ecx
|
|
-# ifdef USE_AS_WCSCMP
|
|
- subl $0xff, %ecx
|
|
-# else
|
|
- incl %ecx
|
|
-# endif
|
|
- je L(test_2_vec)
|
|
- tzcntl %ecx, %edi
|
|
-# ifdef USE_AS_WCSCMP
|
|
- /* NB: Multiply wchar_t count by 4 to get the number of bytes. */
|
|
- sall $2, %edi
|
|
-# endif
|
|
-# ifdef USE_AS_STRNCMP
|
|
- addq $VEC_SIZE, %rdi
|
|
- cmpq %rdi, %r11
|
|
- jbe L(zero)
|
|
-# ifdef USE_AS_WCSCMP
|
|
- movq %rax, %rsi
|
|
- xorl %eax, %eax
|
|
- movl (%rsi, %rdi), %ecx
|
|
- cmpl (%rdx, %rdi), %ecx
|
|
- jne L(wcscmp_return)
|
|
-# else
|
|
- movzbl (%rax, %rdi), %eax
|
|
- movzbl (%rdx, %rdi), %edx
|
|
- subl %edx, %eax
|
|
-# endif
|
|
-# else
|
|
-# ifdef USE_AS_WCSCMP
|
|
- movq %rax, %rsi
|
|
- xorl %eax, %eax
|
|
- movl VEC_SIZE(%rsi, %rdi), %ecx
|
|
- cmpl VEC_SIZE(%rdx, %rdi), %ecx
|
|
- jne L(wcscmp_return)
|
|
-# else
|
|
- movzbl VEC_SIZE(%rax, %rdi), %eax
|
|
- movzbl VEC_SIZE(%rdx, %rdi), %edx
|
|
- subl %edx, %eax
|
|
-# endif
|
|
-# endif
|
|
- ret
|
|
+ TESTEQ %ecx
|
|
+ jnz L(return_vec_1_end)
|
|
|
|
- .p2align 4
|
|
-L(test_2_vec):
|
|
+
|
|
+ /* Handle VEC 2 and 3 without branches. */
|
|
+L(return_vec_2_3_end):
|
|
# ifdef USE_AS_STRNCMP
|
|
- /* The first 2 vectors matched. Return 0 if the maximum offset
|
|
- (%r11) <= 2 * VEC_SIZE. */
|
|
- cmpq $(VEC_SIZE * 2), %r11
|
|
- jbe L(zero)
|
|
+ subq $(CHAR_PER_VEC * 2), %rdx
|
|
+ jbe L(ret_zero_end)
|
|
# endif
|
|
- /* Each bit set in K1 represents a non-null CHAR in YMM4. */
|
|
+
|
|
VPTESTM %YMM4, %YMM4, %k1
|
|
- /* Each bit cleared in K0 represents a mismatch or a null CHAR
|
|
- in YMM4 and (VEC_SIZE * 2)(%rdx). */
|
|
VPCMP $0, %YMMZERO, %YMM5, %k0{%k1}
|
|
kmovd %k0, %ecx
|
|
-# ifdef USE_AS_WCSCMP
|
|
- subl $0xff, %ecx
|
|
+ TESTEQ %ecx
|
|
+# if CHAR_PER_VEC <= 16
|
|
+ sall $CHAR_PER_VEC, %LOOP_REG
|
|
+ orl %ecx, %LOOP_REG
|
|
# else
|
|
- incl %ecx
|
|
+ salq $CHAR_PER_VEC, %LOOP_REG64
|
|
+ orq %rcx, %LOOP_REG64
|
|
+# endif
|
|
+L(return_vec_3_end):
|
|
+ /* LOOP_REG contains matches for null/mismatch from the loop. If
|
|
+ VEC 0,1,and 2 all have no null and no mismatches then mismatch
|
|
+ must entirely be from VEC 3 which is fully represented by
|
|
+ LOOP_REG. */
|
|
+# if CHAR_PER_VEC <= 16
|
|
+ tzcntl %LOOP_REG, %LOOP_REG
|
|
+# else
|
|
+ tzcntq %LOOP_REG64, %LOOP_REG64
|
|
+# endif
|
|
+# ifdef USE_AS_STRNCMP
|
|
+ cmpq %LOOP_REG64, %rdx
|
|
+ jbe L(ret_zero_end)
|
|
# endif
|
|
- je L(test_3_vec)
|
|
- tzcntl %ecx, %edi
|
|
+
|
|
# ifdef USE_AS_WCSCMP
|
|
- /* NB: Multiply wchar_t count by 4 to get the number of bytes. */
|
|
- sall $2, %edi
|
|
+ movl (VEC_SIZE * 2)(%rdi, %LOOP_REG64, SIZE_OF_CHAR), %ecx
|
|
+ xorl %eax, %eax
|
|
+ cmpl (VEC_SIZE * 2)(%rsi, %LOOP_REG64, SIZE_OF_CHAR), %ecx
|
|
+ je L(ret5)
|
|
+ setl %al
|
|
+ negl %eax
|
|
+ xorl %r8d, %eax
|
|
+# else
|
|
+ movzbl (VEC_SIZE * 2)(%rdi, %LOOP_REG64), %eax
|
|
+ movzbl (VEC_SIZE * 2)(%rsi, %LOOP_REG64), %ecx
|
|
+ subl %ecx, %eax
|
|
+ xorl %r8d, %eax
|
|
+ subl %r8d, %eax
|
|
# endif
|
|
+L(ret5):
|
|
+ ret
|
|
+
|
|
# ifdef USE_AS_STRNCMP
|
|
- addq $(VEC_SIZE * 2), %rdi
|
|
- cmpq %rdi, %r11
|
|
- jbe L(zero)
|
|
-# ifdef USE_AS_WCSCMP
|
|
- movq %rax, %rsi
|
|
+ .p2align 4,, 2
|
|
+L(ret_zero_end):
|
|
xorl %eax, %eax
|
|
- movl (%rsi, %rdi), %ecx
|
|
- cmpl (%rdx, %rdi), %ecx
|
|
- jne L(wcscmp_return)
|
|
+ ret
|
|
+# endif
|
|
+
|
|
+
|
|
+ /* The L(return_vec_N_end) differ from L(return_vec_N) in that
|
|
+ they use the value of `r8` to negate the return value. This is
|
|
+ because the page cross logic can swap `rdi` and `rsi`. */
|
|
+ .p2align 4,, 10
|
|
+# ifdef USE_AS_STRNCMP
|
|
+L(return_vec_1_end):
|
|
+# if CHAR_PER_VEC <= 16
|
|
+ sall $CHAR_PER_VEC, %ecx
|
|
# else
|
|
- movzbl (%rax, %rdi), %eax
|
|
- movzbl (%rdx, %rdi), %edx
|
|
- subl %edx, %eax
|
|
+ salq $CHAR_PER_VEC, %rcx
|
|
# endif
|
|
+# endif
|
|
+L(return_vec_0_end):
|
|
+# if (CHAR_PER_VEC <= 16) || !(defined USE_AS_STRNCMP)
|
|
+ tzcntl %ecx, %ecx
|
|
# else
|
|
-# ifdef USE_AS_WCSCMP
|
|
- movq %rax, %rsi
|
|
- xorl %eax, %eax
|
|
- movl (VEC_SIZE * 2)(%rsi, %rdi), %ecx
|
|
- cmpl (VEC_SIZE * 2)(%rdx, %rdi), %ecx
|
|
- jne L(wcscmp_return)
|
|
-# else
|
|
- movzbl (VEC_SIZE * 2)(%rax, %rdi), %eax
|
|
- movzbl (VEC_SIZE * 2)(%rdx, %rdi), %edx
|
|
- subl %edx, %eax
|
|
-# endif
|
|
+ tzcntq %rcx, %rcx
|
|
# endif
|
|
- ret
|
|
|
|
- .p2align 4
|
|
-L(test_3_vec):
|
|
# ifdef USE_AS_STRNCMP
|
|
- /* The first 3 vectors matched. Return 0 if the maximum offset
|
|
- (%r11) <= 3 * VEC_SIZE. */
|
|
- cmpq $(VEC_SIZE * 3), %r11
|
|
- jbe L(zero)
|
|
+ cmpq %rcx, %rdx
|
|
+ jbe L(ret_zero_end)
|
|
# endif
|
|
- /* Each bit set in K1 represents a non-null CHAR in YMM6. */
|
|
- VPTESTM %YMM6, %YMM6, %k1
|
|
- /* Each bit cleared in K0 represents a mismatch or a null CHAR
|
|
- in YMM6 and (VEC_SIZE * 3)(%rdx). */
|
|
- VPCMP $0, %YMMZERO, %YMM7, %k0{%k1}
|
|
- kmovd %k0, %ecx
|
|
+
|
|
# ifdef USE_AS_WCSCMP
|
|
- subl $0xff, %ecx
|
|
+ movl (%rdi, %rcx, SIZE_OF_CHAR), %edx
|
|
+ xorl %eax, %eax
|
|
+ cmpl (%rsi, %rcx, SIZE_OF_CHAR), %edx
|
|
+ je L(ret6)
|
|
+ setl %al
|
|
+ negl %eax
|
|
+ /* This is the non-zero case for `eax` so just xorl with `r8d`
|
|
+ flip is `rdi` and `rsi` where swapped. */
|
|
+ xorl %r8d, %eax
|
|
# else
|
|
- incl %ecx
|
|
+ movzbl (%rdi, %rcx), %eax
|
|
+ movzbl (%rsi, %rcx), %ecx
|
|
+ subl %ecx, %eax
|
|
+ /* Flip `eax` if `rdi` and `rsi` where swapped in page cross
|
|
+ logic. Subtract `r8d` after xor for zero case. */
|
|
+ xorl %r8d, %eax
|
|
+ subl %r8d, %eax
|
|
# endif
|
|
+L(ret6):
|
|
+ ret
|
|
+
|
|
+# ifndef USE_AS_STRNCMP
|
|
+ .p2align 4,, 10
|
|
+L(return_vec_1_end):
|
|
tzcntl %ecx, %ecx
|
|
-# ifdef USE_AS_WCSCMP
|
|
- /* NB: Multiply wchar_t count by 4 to get the number of bytes. */
|
|
- sall $2, %ecx
|
|
-# endif
|
|
-# ifdef USE_AS_STRNCMP
|
|
- addq $(VEC_SIZE * 3), %rcx
|
|
- cmpq %rcx, %r11
|
|
- jbe L(zero)
|
|
# ifdef USE_AS_WCSCMP
|
|
- movq %rax, %rsi
|
|
+ movl VEC_SIZE(%rdi, %rcx, SIZE_OF_CHAR), %edx
|
|
xorl %eax, %eax
|
|
- movl (%rsi, %rcx), %esi
|
|
- cmpl (%rdx, %rcx), %esi
|
|
- jne L(wcscmp_return)
|
|
-# else
|
|
- movzbl (%rax, %rcx), %eax
|
|
- movzbl (%rdx, %rcx), %edx
|
|
- subl %edx, %eax
|
|
-# endif
|
|
-# else
|
|
-# ifdef USE_AS_WCSCMP
|
|
- movq %rax, %rsi
|
|
- xorl %eax, %eax
|
|
- movl (VEC_SIZE * 3)(%rsi, %rcx), %esi
|
|
- cmpl (VEC_SIZE * 3)(%rdx, %rcx), %esi
|
|
- jne L(wcscmp_return)
|
|
+ cmpl VEC_SIZE(%rsi, %rcx, SIZE_OF_CHAR), %edx
|
|
+ je L(ret7)
|
|
+ setl %al
|
|
+ negl %eax
|
|
+ xorl %r8d, %eax
|
|
# else
|
|
- movzbl (VEC_SIZE * 3)(%rax, %rcx), %eax
|
|
- movzbl (VEC_SIZE * 3)(%rdx, %rcx), %edx
|
|
- subl %edx, %eax
|
|
+ movzbl VEC_SIZE(%rdi, %rcx), %eax
|
|
+ movzbl VEC_SIZE(%rsi, %rcx), %ecx
|
|
+ subl %ecx, %eax
|
|
+ xorl %r8d, %eax
|
|
+ subl %r8d, %eax
|
|
# endif
|
|
-# endif
|
|
+L(ret7):
|
|
ret
|
|
-
|
|
- .p2align 4
|
|
-L(loop_cross_page):
|
|
- xorl %r10d, %r10d
|
|
- movq %rdx, %rcx
|
|
- /* Align load via RDX. We load the extra ECX bytes which should
|
|
- be ignored. */
|
|
- andl $((VEC_SIZE * 4) - 1), %ecx
|
|
- /* R10 is -RCX. */
|
|
- subq %rcx, %r10
|
|
-
|
|
- /* This works only if VEC_SIZE * 2 == 64. */
|
|
-# if (VEC_SIZE * 2) != 64
|
|
-# error (VEC_SIZE * 2) != 64
|
|
# endif
|
|
|
|
- /* Check if the first VEC_SIZE * 2 bytes should be ignored. */
|
|
- cmpl $(VEC_SIZE * 2), %ecx
|
|
- jge L(loop_cross_page_2_vec)
|
|
|
|
- VMOVU (%rax, %r10), %YMM2
|
|
- VMOVU VEC_SIZE(%rax, %r10), %YMM3
|
|
+ /* Page cross in rsi in next 4x VEC. */
|
|
|
|
- /* Each bit set in K2 represents a non-null CHAR in YMM2. */
|
|
- VPTESTM %YMM2, %YMM2, %k2
|
|
- /* Each bit cleared in K1 represents a mismatch or a null CHAR
|
|
- in YMM2 and 32 bytes at (%rdx, %r10). */
|
|
- VPCMP $0, (%rdx, %r10), %YMM2, %k1{%k2}
|
|
- kmovd %k1, %r9d
|
|
- /* Don't use subl since it is the lower 16/32 bits of RDI
|
|
- below. */
|
|
- notl %r9d
|
|
-# ifdef USE_AS_WCSCMP
|
|
- /* Only last 8 bits are valid. */
|
|
- andl $0xff, %r9d
|
|
-# endif
|
|
+ /* TODO: Improve logic here. */
|
|
+ .p2align 4,, 10
|
|
+L(page_cross_during_loop):
|
|
+ /* eax contains [distance_from_page - (VEC_SIZE * 4)]. */
|
|
|
|
- /* Each bit set in K4 represents a non-null CHAR in YMM3. */
|
|
- VPTESTM %YMM3, %YMM3, %k4
|
|
- /* Each bit cleared in K3 represents a mismatch or a null CHAR
|
|
- in YMM3 and 32 bytes at VEC_SIZE(%rdx, %r10). */
|
|
- VPCMP $0, VEC_SIZE(%rdx, %r10), %YMM3, %k3{%k4}
|
|
- kmovd %k3, %edi
|
|
- /* Must use notl %edi here as lower bits are for CHAR
|
|
- comparisons potentially out of range thus can be 0 without
|
|
- indicating mismatch. */
|
|
- notl %edi
|
|
-# ifdef USE_AS_WCSCMP
|
|
- /* Don't use subl since it is the upper 8 bits of EDI below. */
|
|
- andl $0xff, %edi
|
|
-# endif
|
|
+ /* Optimistically rsi and rdi and both aligned in which case we
|
|
+ don't need any logic here. */
|
|
+ cmpl $-(VEC_SIZE * 4), %eax
|
|
+ /* Don't adjust eax before jumping back to loop and we will
|
|
+ never hit page cross case again. */
|
|
+ je L(loop_skip_page_cross_check)
|
|
|
|
-# ifdef USE_AS_WCSCMP
|
|
- /* NB: Each bit in EDI/R9D represents 4-byte element. */
|
|
- sall $8, %edi
|
|
- /* NB: Divide shift count by 4 since each bit in K1 represent 4
|
|
- bytes. */
|
|
- movl %ecx, %SHIFT_REG32
|
|
- sarl $2, %SHIFT_REG32
|
|
-
|
|
- /* Each bit in EDI represents a null CHAR or a mismatch. */
|
|
- orl %r9d, %edi
|
|
-# else
|
|
- salq $32, %rdi
|
|
+ /* Check if we can safely load a VEC. */
|
|
+ cmpl $-(VEC_SIZE * 3), %eax
|
|
+ jle L(less_1x_vec_till_page_cross)
|
|
|
|
- /* Each bit in RDI represents a null CHAR or a mismatch. */
|
|
- orq %r9, %rdi
|
|
-# endif
|
|
+ VMOVA (%rdi), %YMM0
|
|
+ VPTESTM %YMM0, %YMM0, %k2
|
|
+ VPCMP $0, (%rsi), %YMM0, %k1{%k2}
|
|
+ kmovd %k1, %ecx
|
|
+ TESTEQ %ecx
|
|
+ jnz L(return_vec_0_end)
|
|
+
|
|
+ /* if distance >= 2x VEC then eax > -(VEC_SIZE * 2). */
|
|
+ cmpl $-(VEC_SIZE * 2), %eax
|
|
+ jg L(more_2x_vec_till_page_cross)
|
|
+
|
|
+ .p2align 4,, 4
|
|
+L(less_1x_vec_till_page_cross):
|
|
+ subl $-(VEC_SIZE * 4), %eax
|
|
+ /* Guranteed safe to read from rdi - VEC_SIZE here. The only
|
|
+ concerning case is first iteration if incoming s1 was near start
|
|
+ of a page and s2 near end. If s1 was near the start of the page
|
|
+ we already aligned up to nearest VEC_SIZE * 4 so gurnateed safe
|
|
+ to read back -VEC_SIZE. If rdi is truly at the start of a page
|
|
+ here, it means the previous page (rdi - VEC_SIZE) has already
|
|
+ been loaded earlier so must be valid. */
|
|
+ VMOVU -VEC_SIZE(%rdi, %rax), %YMM0
|
|
+ VPTESTM %YMM0, %YMM0, %k2
|
|
+ VPCMP $0, -VEC_SIZE(%rsi, %rax), %YMM0, %k1{%k2}
|
|
+
|
|
+ /* Mask of potentially valid bits. The lower bits can be out of
|
|
+ range comparisons (but safe regarding page crosses). */
|
|
|
|
- /* Since ECX < VEC_SIZE * 2, simply skip the first ECX bytes. */
|
|
- shrxq %SHIFT_REG64, %rdi, %rdi
|
|
- testq %rdi, %rdi
|
|
- je L(loop_cross_page_2_vec)
|
|
- tzcntq %rdi, %rcx
|
|
# ifdef USE_AS_WCSCMP
|
|
- /* NB: Multiply wchar_t count by 4 to get the number of bytes. */
|
|
- sall $2, %ecx
|
|
+ movl $-1, %r10d
|
|
+ movl %esi, %ecx
|
|
+ andl $(VEC_SIZE - 1), %ecx
|
|
+ shrl $2, %ecx
|
|
+ shlxl %ecx, %r10d, %ecx
|
|
+ movzbl %cl, %r10d
|
|
+# else
|
|
+ movl $-1, %ecx
|
|
+ shlxl %esi, %ecx, %r10d
|
|
# endif
|
|
+
|
|
+ kmovd %k1, %ecx
|
|
+ notl %ecx
|
|
+
|
|
+
|
|
# ifdef USE_AS_STRNCMP
|
|
- cmpq %rcx, %r11
|
|
- jbe L(zero)
|
|
# ifdef USE_AS_WCSCMP
|
|
- movq %rax, %rsi
|
|
- xorl %eax, %eax
|
|
- movl (%rsi, %rcx), %edi
|
|
- cmpl (%rdx, %rcx), %edi
|
|
- jne L(wcscmp_return)
|
|
+ movl %eax, %r11d
|
|
+ shrl $2, %r11d
|
|
+ cmpq %r11, %rdx
|
|
# else
|
|
- movzbl (%rax, %rcx), %eax
|
|
- movzbl (%rdx, %rcx), %edx
|
|
- subl %edx, %eax
|
|
+ cmpq %rax, %rdx
|
|
# endif
|
|
+ jbe L(return_page_cross_end_check)
|
|
+# endif
|
|
+ movl %eax, %OFFSET_REG
|
|
+
|
|
+ /* Readjust eax before potentially returning to the loop. */
|
|
+ addl $(PAGE_SIZE - VEC_SIZE * 4), %eax
|
|
+
|
|
+ andl %r10d, %ecx
|
|
+ jz L(loop_skip_page_cross_check)
|
|
+
|
|
+ .p2align 4,, 3
|
|
+L(return_page_cross_end):
|
|
+ tzcntl %ecx, %ecx
|
|
+
|
|
+# if (defined USE_AS_STRNCMP) || (defined USE_AS_WCSCMP)
|
|
+ leal -VEC_SIZE(%OFFSET_REG64, %rcx, SIZE_OF_CHAR), %ecx
|
|
+L(return_page_cross_cmp_mem):
|
|
# else
|
|
-# ifdef USE_AS_WCSCMP
|
|
- movq %rax, %rsi
|
|
+ addl %OFFSET_REG, %ecx
|
|
+# endif
|
|
+# ifdef USE_AS_WCSCMP
|
|
+ movl VEC_OFFSET(%rdi, %rcx), %edx
|
|
xorl %eax, %eax
|
|
- movl (%rsi, %rcx), %edi
|
|
- cmpl (%rdx, %rcx), %edi
|
|
- jne L(wcscmp_return)
|
|
-# else
|
|
- movzbl (%rax, %rcx), %eax
|
|
- movzbl (%rdx, %rcx), %edx
|
|
- subl %edx, %eax
|
|
-# endif
|
|
+ cmpl VEC_OFFSET(%rsi, %rcx), %edx
|
|
+ je L(ret8)
|
|
+ setl %al
|
|
+ negl %eax
|
|
+ xorl %r8d, %eax
|
|
+# else
|
|
+ movzbl VEC_OFFSET(%rdi, %rcx), %eax
|
|
+ movzbl VEC_OFFSET(%rsi, %rcx), %ecx
|
|
+ subl %ecx, %eax
|
|
+ xorl %r8d, %eax
|
|
+ subl %r8d, %eax
|
|
# endif
|
|
+L(ret8):
|
|
ret
|
|
|
|
- .p2align 4
|
|
-L(loop_cross_page_2_vec):
|
|
- /* The first VEC_SIZE * 2 bytes match or are ignored. */
|
|
- VMOVU (VEC_SIZE * 2)(%rax, %r10), %YMM0
|
|
- VMOVU (VEC_SIZE * 3)(%rax, %r10), %YMM1
|
|
+# ifdef USE_AS_STRNCMP
|
|
+ .p2align 4,, 10
|
|
+L(return_page_cross_end_check):
|
|
+ tzcntl %ecx, %ecx
|
|
+ leal -VEC_SIZE(%rax, %rcx, SIZE_OF_CHAR), %ecx
|
|
+# ifdef USE_AS_WCSCMP
|
|
+ sall $2, %edx
|
|
+# endif
|
|
+ cmpl %ecx, %edx
|
|
+ ja L(return_page_cross_cmp_mem)
|
|
+ xorl %eax, %eax
|
|
+ ret
|
|
+# endif
|
|
+
|
|
|
|
+ .p2align 4,, 10
|
|
+L(more_2x_vec_till_page_cross):
|
|
+ /* If more 2x vec till cross we will complete a full loop
|
|
+ iteration here. */
|
|
+
|
|
+ VMOVA VEC_SIZE(%rdi), %YMM0
|
|
VPTESTM %YMM0, %YMM0, %k2
|
|
- /* Each bit cleared in K1 represents a mismatch or a null CHAR
|
|
- in YMM0 and 32 bytes at (VEC_SIZE * 2)(%rdx, %r10). */
|
|
- VPCMP $0, (VEC_SIZE * 2)(%rdx, %r10), %YMM0, %k1{%k2}
|
|
- kmovd %k1, %r9d
|
|
- /* Don't use subl since it is the lower 16/32 bits of RDI
|
|
- below. */
|
|
- notl %r9d
|
|
-# ifdef USE_AS_WCSCMP
|
|
- /* Only last 8 bits are valid. */
|
|
- andl $0xff, %r9d
|
|
-# endif
|
|
+ VPCMP $0, VEC_SIZE(%rsi), %YMM0, %k1{%k2}
|
|
+ kmovd %k1, %ecx
|
|
+ TESTEQ %ecx
|
|
+ jnz L(return_vec_1_end)
|
|
|
|
- VPTESTM %YMM1, %YMM1, %k4
|
|
- /* Each bit cleared in K3 represents a mismatch or a null CHAR
|
|
- in YMM1 and 32 bytes at (VEC_SIZE * 3)(%rdx, %r10). */
|
|
- VPCMP $0, (VEC_SIZE * 3)(%rdx, %r10), %YMM1, %k3{%k4}
|
|
- kmovd %k3, %edi
|
|
- /* Must use notl %edi here as lower bits are for CHAR
|
|
- comparisons potentially out of range thus can be 0 without
|
|
- indicating mismatch. */
|
|
- notl %edi
|
|
-# ifdef USE_AS_WCSCMP
|
|
- /* Don't use subl since it is the upper 8 bits of EDI below. */
|
|
- andl $0xff, %edi
|
|
+# ifdef USE_AS_STRNCMP
|
|
+ cmpq $(CHAR_PER_VEC * 2), %rdx
|
|
+ jbe L(ret_zero_in_loop_page_cross)
|
|
# endif
|
|
|
|
-# ifdef USE_AS_WCSCMP
|
|
- /* NB: Each bit in EDI/R9D represents 4-byte element. */
|
|
- sall $8, %edi
|
|
+ subl $-(VEC_SIZE * 4), %eax
|
|
|
|
- /* Each bit in EDI represents a null CHAR or a mismatch. */
|
|
- orl %r9d, %edi
|
|
-# else
|
|
- salq $32, %rdi
|
|
+ /* Safe to include comparisons from lower bytes. */
|
|
+ VMOVU -(VEC_SIZE * 2)(%rdi, %rax), %YMM0
|
|
+ VPTESTM %YMM0, %YMM0, %k2
|
|
+ VPCMP $0, -(VEC_SIZE * 2)(%rsi, %rax), %YMM0, %k1{%k2}
|
|
+ kmovd %k1, %ecx
|
|
+ TESTEQ %ecx
|
|
+ jnz L(return_vec_page_cross_0)
|
|
+
|
|
+ VMOVU -(VEC_SIZE * 1)(%rdi, %rax), %YMM0
|
|
+ VPTESTM %YMM0, %YMM0, %k2
|
|
+ VPCMP $0, -(VEC_SIZE * 1)(%rsi, %rax), %YMM0, %k1{%k2}
|
|
+ kmovd %k1, %ecx
|
|
+ TESTEQ %ecx
|
|
+ jnz L(return_vec_page_cross_1)
|
|
|
|
- /* Each bit in RDI represents a null CHAR or a mismatch. */
|
|
- orq %r9, %rdi
|
|
+# ifdef USE_AS_STRNCMP
|
|
+ /* Must check length here as length might proclude reading next
|
|
+ page. */
|
|
+# ifdef USE_AS_WCSCMP
|
|
+ movl %eax, %r11d
|
|
+ shrl $2, %r11d
|
|
+ cmpq %r11, %rdx
|
|
+# else
|
|
+ cmpq %rax, %rdx
|
|
+# endif
|
|
+ jbe L(ret_zero_in_loop_page_cross)
|
|
# endif
|
|
|
|
- xorl %r8d, %r8d
|
|
- /* If ECX > VEC_SIZE * 2, skip ECX - (VEC_SIZE * 2) bytes. */
|
|
- subl $(VEC_SIZE * 2), %ecx
|
|
- jle 1f
|
|
- /* R8 has number of bytes skipped. */
|
|
- movl %ecx, %r8d
|
|
-# ifdef USE_AS_WCSCMP
|
|
- /* NB: Divide shift count by 4 since each bit in RDI represent 4
|
|
- bytes. */
|
|
- sarl $2, %ecx
|
|
- /* Skip ECX bytes. */
|
|
- shrl %cl, %edi
|
|
+ /* Finish the loop. */
|
|
+ VMOVA (VEC_SIZE * 2)(%rdi), %YMM4
|
|
+ VMOVA (VEC_SIZE * 3)(%rdi), %YMM6
|
|
+ VPMINU %YMM4, %YMM6, %YMM9
|
|
+ VPTESTM %YMM9, %YMM9, %k1
|
|
+
|
|
+ vpxorq (VEC_SIZE * 2)(%rsi), %YMM4, %YMM5
|
|
+ /* YMM6 = YMM5 | ((VEC_SIZE * 3)(%rsi) ^ YMM6). */
|
|
+ vpternlogd $0xde, (VEC_SIZE * 3)(%rsi), %YMM5, %YMM6
|
|
+
|
|
+ VPCMP $0, %YMMZERO, %YMM6, %k0{%k1}
|
|
+ kmovd %k0, %LOOP_REG
|
|
+ TESTEQ %LOOP_REG
|
|
+ jnz L(return_vec_2_3_end)
|
|
+
|
|
+ /* Best for code size to include ucond-jmp here. Would be faster
|
|
+ if this case is hot to duplicate the L(return_vec_2_3_end) code
|
|
+ as fall-through and have jump back to loop on mismatch
|
|
+ comparison. */
|
|
+ subq $-(VEC_SIZE * 4), %rdi
|
|
+ subq $-(VEC_SIZE * 4), %rsi
|
|
+ addl $(PAGE_SIZE - VEC_SIZE * 8), %eax
|
|
+# ifdef USE_AS_STRNCMP
|
|
+ subq $(CHAR_PER_VEC * 4), %rdx
|
|
+ ja L(loop_skip_page_cross_check)
|
|
+L(ret_zero_in_loop_page_cross):
|
|
+ xorl %eax, %eax
|
|
+ ret
|
|
# else
|
|
- /* Skip ECX bytes. */
|
|
- shrq %cl, %rdi
|
|
+ jmp L(loop_skip_page_cross_check)
|
|
# endif
|
|
-1:
|
|
- /* Before jumping back to the loop, set ESI to the number of
|
|
- VEC_SIZE * 4 blocks before page crossing. */
|
|
- movl $(PAGE_SIZE / (VEC_SIZE * 4) - 1), %esi
|
|
|
|
- testq %rdi, %rdi
|
|
-# ifdef USE_AS_STRNCMP
|
|
- /* At this point, if %rdi value is 0, it already tested
|
|
- VEC_SIZE*4+%r10 byte starting from %rax. This label
|
|
- checks whether strncmp maximum offset reached or not. */
|
|
- je L(string_nbyte_offset_check)
|
|
+
|
|
+ .p2align 4,, 10
|
|
+L(return_vec_page_cross_0):
|
|
+ addl $-VEC_SIZE, %eax
|
|
+L(return_vec_page_cross_1):
|
|
+ tzcntl %ecx, %ecx
|
|
+# if defined USE_AS_STRNCMP || defined USE_AS_WCSCMP
|
|
+ leal -VEC_SIZE(%rax, %rcx, SIZE_OF_CHAR), %ecx
|
|
+# ifdef USE_AS_STRNCMP
|
|
+# ifdef USE_AS_WCSCMP
|
|
+ /* Must divide ecx instead of multiply rdx due to overflow. */
|
|
+ movl %ecx, %eax
|
|
+ shrl $2, %eax
|
|
+ cmpq %rax, %rdx
|
|
+# else
|
|
+ cmpq %rcx, %rdx
|
|
+# endif
|
|
+ jbe L(ret_zero_in_loop_page_cross)
|
|
+# endif
|
|
# else
|
|
- je L(back_to_loop)
|
|
+ addl %eax, %ecx
|
|
# endif
|
|
- tzcntq %rdi, %rcx
|
|
+
|
|
# ifdef USE_AS_WCSCMP
|
|
- /* NB: Multiply wchar_t count by 4 to get the number of bytes. */
|
|
- sall $2, %ecx
|
|
-# endif
|
|
- addq %r10, %rcx
|
|
- /* Adjust for number of bytes skipped. */
|
|
- addq %r8, %rcx
|
|
-# ifdef USE_AS_STRNCMP
|
|
- addq $(VEC_SIZE * 2), %rcx
|
|
- subq %rcx, %r11
|
|
- jbe L(zero)
|
|
-# ifdef USE_AS_WCSCMP
|
|
- movq %rax, %rsi
|
|
+ movl VEC_OFFSET(%rdi, %rcx), %edx
|
|
xorl %eax, %eax
|
|
- movl (%rsi, %rcx), %edi
|
|
- cmpl (%rdx, %rcx), %edi
|
|
- jne L(wcscmp_return)
|
|
-# else
|
|
- movzbl (%rax, %rcx), %eax
|
|
- movzbl (%rdx, %rcx), %edx
|
|
- subl %edx, %eax
|
|
-# endif
|
|
+ cmpl VEC_OFFSET(%rsi, %rcx), %edx
|
|
+ je L(ret9)
|
|
+ setl %al
|
|
+ negl %eax
|
|
+ xorl %r8d, %eax
|
|
# else
|
|
-# ifdef USE_AS_WCSCMP
|
|
- movq %rax, %rsi
|
|
- xorl %eax, %eax
|
|
- movl (VEC_SIZE * 2)(%rsi, %rcx), %edi
|
|
- cmpl (VEC_SIZE * 2)(%rdx, %rcx), %edi
|
|
- jne L(wcscmp_return)
|
|
-# else
|
|
- movzbl (VEC_SIZE * 2)(%rax, %rcx), %eax
|
|
- movzbl (VEC_SIZE * 2)(%rdx, %rcx), %edx
|
|
- subl %edx, %eax
|
|
-# endif
|
|
+ movzbl VEC_OFFSET(%rdi, %rcx), %eax
|
|
+ movzbl VEC_OFFSET(%rsi, %rcx), %ecx
|
|
+ subl %ecx, %eax
|
|
+ xorl %r8d, %eax
|
|
+ subl %r8d, %eax
|
|
# endif
|
|
+L(ret9):
|
|
ret
|
|
|
|
-# ifdef USE_AS_STRNCMP
|
|
-L(string_nbyte_offset_check):
|
|
- leaq (VEC_SIZE * 4)(%r10), %r10
|
|
- cmpq %r10, %r11
|
|
- jbe L(zero)
|
|
- jmp L(back_to_loop)
|
|
+
|
|
+ .p2align 4,, 10
|
|
+L(page_cross):
|
|
+# ifndef USE_AS_STRNCMP
|
|
+ /* If both are VEC aligned we don't need any special logic here.
|
|
+ Only valid for strcmp where stop condition is guranteed to be
|
|
+ reachable by just reading memory. */
|
|
+ testl $((VEC_SIZE - 1) << 20), %eax
|
|
+ jz L(no_page_cross)
|
|
# endif
|
|
|
|
- .p2align 4
|
|
-L(cross_page_loop):
|
|
- /* Check one byte/dword at a time. */
|
|
+ movl %edi, %eax
|
|
+ movl %esi, %ecx
|
|
+ andl $(PAGE_SIZE - 1), %eax
|
|
+ andl $(PAGE_SIZE - 1), %ecx
|
|
+
|
|
+ xorl %OFFSET_REG, %OFFSET_REG
|
|
+
|
|
+ /* Check which is closer to page cross, s1 or s2. */
|
|
+ cmpl %eax, %ecx
|
|
+ jg L(page_cross_s2)
|
|
+
|
|
+ /* The previous page cross check has false positives. Check for
|
|
+ true positive as page cross logic is very expensive. */
|
|
+ subl $(PAGE_SIZE - VEC_SIZE * 4), %eax
|
|
+ jbe L(no_page_cross)
|
|
+
|
|
+
|
|
+ /* Set r8 to not interfere with normal return value (rdi and rsi
|
|
+ did not swap). */
|
|
# ifdef USE_AS_WCSCMP
|
|
- cmpl %ecx, %eax
|
|
+ /* any non-zero positive value that doesn't inference with 0x1.
|
|
+ */
|
|
+ movl $2, %r8d
|
|
# else
|
|
- subl %ecx, %eax
|
|
+ xorl %r8d, %r8d
|
|
# endif
|
|
- jne L(different)
|
|
- addl $SIZE_OF_CHAR, %edx
|
|
- cmpl $(VEC_SIZE * 4), %edx
|
|
- je L(main_loop_header)
|
|
+
|
|
+ /* Check if less than 1x VEC till page cross. */
|
|
+ subl $(VEC_SIZE * 3), %eax
|
|
+ jg L(less_1x_vec_till_page)
|
|
+
|
|
+
|
|
+ /* If more than 1x VEC till page cross, loop throuh safely
|
|
+ loadable memory until within 1x VEC of page cross. */
|
|
+ .p2align 4,, 8
|
|
+L(page_cross_loop):
|
|
+ VMOVU (%rdi, %OFFSET_REG64, SIZE_OF_CHAR), %YMM0
|
|
+ VPTESTM %YMM0, %YMM0, %k2
|
|
+ VPCMP $0, (%rsi, %OFFSET_REG64, SIZE_OF_CHAR), %YMM0, %k1{%k2}
|
|
+ kmovd %k1, %ecx
|
|
+ TESTEQ %ecx
|
|
+ jnz L(check_ret_vec_page_cross)
|
|
+ addl $CHAR_PER_VEC, %OFFSET_REG
|
|
# ifdef USE_AS_STRNCMP
|
|
- cmpq %r11, %rdx
|
|
- jae L(zero)
|
|
+ cmpq %OFFSET_REG64, %rdx
|
|
+ jbe L(ret_zero_page_cross)
|
|
# endif
|
|
+ addl $VEC_SIZE, %eax
|
|
+ jl L(page_cross_loop)
|
|
+
|
|
# ifdef USE_AS_WCSCMP
|
|
- movl (%rdi, %rdx), %eax
|
|
- movl (%rsi, %rdx), %ecx
|
|
-# else
|
|
- movzbl (%rdi, %rdx), %eax
|
|
- movzbl (%rsi, %rdx), %ecx
|
|
+ shrl $2, %eax
|
|
# endif
|
|
- /* Check null CHAR. */
|
|
- testl %eax, %eax
|
|
- jne L(cross_page_loop)
|
|
- /* Since %eax == 0, subtract is OK for both SIGNED and UNSIGNED
|
|
- comparisons. */
|
|
- subl %ecx, %eax
|
|
-# ifndef USE_AS_WCSCMP
|
|
-L(different):
|
|
+
|
|
+
|
|
+ subl %eax, %OFFSET_REG
|
|
+ /* OFFSET_REG has distance to page cross - VEC_SIZE. Guranteed
|
|
+ to not cross page so is safe to load. Since we have already
|
|
+ loaded at least 1 VEC from rsi it is also guranteed to be safe.
|
|
+ */
|
|
+ VMOVU (%rdi, %OFFSET_REG64, SIZE_OF_CHAR), %YMM0
|
|
+ VPTESTM %YMM0, %YMM0, %k2
|
|
+ VPCMP $0, (%rsi, %OFFSET_REG64, SIZE_OF_CHAR), %YMM0, %k1{%k2}
|
|
+
|
|
+ kmovd %k1, %ecx
|
|
+# ifdef USE_AS_STRNCMP
|
|
+ leal CHAR_PER_VEC(%OFFSET_REG64), %eax
|
|
+ cmpq %rax, %rdx
|
|
+ jbe L(check_ret_vec_page_cross2)
|
|
+# ifdef USE_AS_WCSCMP
|
|
+ addq $-(CHAR_PER_VEC * 2), %rdx
|
|
+# else
|
|
+ addq %rdi, %rdx
|
|
+# endif
|
|
# endif
|
|
- ret
|
|
+ TESTEQ %ecx
|
|
+ jz L(prepare_loop_no_len)
|
|
|
|
+ .p2align 4,, 4
|
|
+L(ret_vec_page_cross):
|
|
+# ifndef USE_AS_STRNCMP
|
|
+L(check_ret_vec_page_cross):
|
|
+# endif
|
|
+ tzcntl %ecx, %ecx
|
|
+ addl %OFFSET_REG, %ecx
|
|
+L(ret_vec_page_cross_cont):
|
|
# ifdef USE_AS_WCSCMP
|
|
- .p2align 4
|
|
-L(different):
|
|
- /* Use movl to avoid modifying EFLAGS. */
|
|
- movl $0, %eax
|
|
+ movl (%rdi, %rcx, SIZE_OF_CHAR), %edx
|
|
+ xorl %eax, %eax
|
|
+ cmpl (%rsi, %rcx, SIZE_OF_CHAR), %edx
|
|
+ je L(ret12)
|
|
setl %al
|
|
negl %eax
|
|
- orl $1, %eax
|
|
- ret
|
|
+ xorl %r8d, %eax
|
|
+# else
|
|
+ movzbl (%rdi, %rcx, SIZE_OF_CHAR), %eax
|
|
+ movzbl (%rsi, %rcx, SIZE_OF_CHAR), %ecx
|
|
+ subl %ecx, %eax
|
|
+ xorl %r8d, %eax
|
|
+ subl %r8d, %eax
|
|
# endif
|
|
+L(ret12):
|
|
+ ret
|
|
+
|
|
|
|
# ifdef USE_AS_STRNCMP
|
|
- .p2align 4
|
|
-L(zero):
|
|
+ .p2align 4,, 10
|
|
+L(check_ret_vec_page_cross2):
|
|
+ TESTEQ %ecx
|
|
+L(check_ret_vec_page_cross):
|
|
+ tzcntl %ecx, %ecx
|
|
+ addl %OFFSET_REG, %ecx
|
|
+ cmpq %rcx, %rdx
|
|
+ ja L(ret_vec_page_cross_cont)
|
|
+ .p2align 4,, 2
|
|
+L(ret_zero_page_cross):
|
|
xorl %eax, %eax
|
|
ret
|
|
+# endif
|
|
|
|
- .p2align 4
|
|
-L(char0):
|
|
-# ifdef USE_AS_WCSCMP
|
|
- xorl %eax, %eax
|
|
- movl (%rdi), %ecx
|
|
- cmpl (%rsi), %ecx
|
|
- jne L(wcscmp_return)
|
|
-# else
|
|
- movzbl (%rsi), %ecx
|
|
- movzbl (%rdi), %eax
|
|
- subl %ecx, %eax
|
|
-# endif
|
|
- ret
|
|
+ .p2align 4,, 4
|
|
+L(page_cross_s2):
|
|
+ /* Ensure this is a true page cross. */
|
|
+ subl $(PAGE_SIZE - VEC_SIZE * 4), %ecx
|
|
+ jbe L(no_page_cross)
|
|
+
|
|
+
|
|
+ movl %ecx, %eax
|
|
+ movq %rdi, %rcx
|
|
+ movq %rsi, %rdi
|
|
+ movq %rcx, %rsi
|
|
+
|
|
+ /* set r8 to negate return value as rdi and rsi swapped. */
|
|
+# ifdef USE_AS_WCSCMP
|
|
+ movl $-4, %r8d
|
|
+# else
|
|
+ movl $-1, %r8d
|
|
# endif
|
|
+ xorl %OFFSET_REG, %OFFSET_REG
|
|
|
|
- .p2align 4
|
|
-L(last_vector):
|
|
- addq %rdx, %rdi
|
|
- addq %rdx, %rsi
|
|
-# ifdef USE_AS_STRNCMP
|
|
- subq %rdx, %r11
|
|
+ /* Check if more than 1x VEC till page cross. */
|
|
+ subl $(VEC_SIZE * 3), %eax
|
|
+ jle L(page_cross_loop)
|
|
+
|
|
+ .p2align 4,, 6
|
|
+L(less_1x_vec_till_page):
|
|
+# ifdef USE_AS_WCSCMP
|
|
+ shrl $2, %eax
|
|
# endif
|
|
- tzcntl %ecx, %edx
|
|
+ /* Find largest load size we can use. */
|
|
+ cmpl $(16 / SIZE_OF_CHAR), %eax
|
|
+ ja L(less_16_till_page)
|
|
+
|
|
+ /* Use 16 byte comparison. */
|
|
+ vmovdqu (%rdi), %xmm0
|
|
+ VPTESTM %xmm0, %xmm0, %k2
|
|
+ VPCMP $0, (%rsi), %xmm0, %k1{%k2}
|
|
+ kmovd %k1, %ecx
|
|
# ifdef USE_AS_WCSCMP
|
|
- /* NB: Multiply wchar_t count by 4 to get the number of bytes. */
|
|
- sall $2, %edx
|
|
+ subl $0xf, %ecx
|
|
+# else
|
|
+ incw %cx
|
|
# endif
|
|
+ jnz L(check_ret_vec_page_cross)
|
|
+ movl $(16 / SIZE_OF_CHAR), %OFFSET_REG
|
|
# ifdef USE_AS_STRNCMP
|
|
- cmpq %r11, %rdx
|
|
- jae L(zero)
|
|
+ cmpq %OFFSET_REG64, %rdx
|
|
+ jbe L(ret_zero_page_cross_slow_case0)
|
|
+ subl %eax, %OFFSET_REG
|
|
+# else
|
|
+ /* Explicit check for 16 byte alignment. */
|
|
+ subl %eax, %OFFSET_REG
|
|
+ jz L(prepare_loop)
|
|
# endif
|
|
+ vmovdqu (%rdi, %OFFSET_REG64, SIZE_OF_CHAR), %xmm0
|
|
+ VPTESTM %xmm0, %xmm0, %k2
|
|
+ VPCMP $0, (%rsi, %OFFSET_REG64, SIZE_OF_CHAR), %xmm0, %k1{%k2}
|
|
+ kmovd %k1, %ecx
|
|
# ifdef USE_AS_WCSCMP
|
|
- xorl %eax, %eax
|
|
- movl (%rdi, %rdx), %ecx
|
|
- cmpl (%rsi, %rdx), %ecx
|
|
- jne L(wcscmp_return)
|
|
+ subl $0xf, %ecx
|
|
# else
|
|
- movzbl (%rdi, %rdx), %eax
|
|
- movzbl (%rsi, %rdx), %edx
|
|
- subl %edx, %eax
|
|
+ incw %cx
|
|
# endif
|
|
+ jnz L(check_ret_vec_page_cross)
|
|
+# ifdef USE_AS_STRNCMP
|
|
+ addl $(16 / SIZE_OF_CHAR), %OFFSET_REG
|
|
+ subq %OFFSET_REG64, %rdx
|
|
+ jbe L(ret_zero_page_cross_slow_case0)
|
|
+ subq $-(CHAR_PER_VEC * 4), %rdx
|
|
+
|
|
+ leaq -(VEC_SIZE * 4)(%rdi, %OFFSET_REG64, SIZE_OF_CHAR), %rdi
|
|
+ leaq -(VEC_SIZE * 4)(%rsi, %OFFSET_REG64, SIZE_OF_CHAR), %rsi
|
|
+# else
|
|
+ leaq (16 - VEC_SIZE * 4)(%rdi, %OFFSET_REG64, SIZE_OF_CHAR), %rdi
|
|
+ leaq (16 - VEC_SIZE * 4)(%rsi, %OFFSET_REG64, SIZE_OF_CHAR), %rsi
|
|
+# endif
|
|
+ jmp L(prepare_loop_aligned)
|
|
+
|
|
+# ifdef USE_AS_STRNCMP
|
|
+ .p2align 4,, 2
|
|
+L(ret_zero_page_cross_slow_case0):
|
|
+ xorl %eax, %eax
|
|
ret
|
|
+# endif
|
|
|
|
- /* Comparing on page boundary region requires special treatment:
|
|
- It must done one vector at the time, starting with the wider
|
|
- ymm vector if possible, if not, with xmm. If fetching 16 bytes
|
|
- (xmm) still passes the boundary, byte comparison must be done.
|
|
- */
|
|
- .p2align 4
|
|
-L(cross_page):
|
|
- /* Try one ymm vector at a time. */
|
|
- cmpl $(PAGE_SIZE - VEC_SIZE), %eax
|
|
- jg L(cross_page_1_vector)
|
|
-L(loop_1_vector):
|
|
- VMOVU (%rdi, %rdx), %YMM0
|
|
|
|
- VPTESTM %YMM0, %YMM0, %k2
|
|
- /* Each bit cleared in K1 represents a mismatch or a null CHAR
|
|
- in YMM0 and 32 bytes at (%rsi, %rdx). */
|
|
- VPCMP $0, (%rsi, %rdx), %YMM0, %k1{%k2}
|
|
+ .p2align 4,, 10
|
|
+L(less_16_till_page):
|
|
+ cmpl $(24 / SIZE_OF_CHAR), %eax
|
|
+ ja L(less_8_till_page)
|
|
+
|
|
+ /* Use 8 byte comparison. */
|
|
+ vmovq (%rdi), %xmm0
|
|
+ vmovq (%rsi), %xmm1
|
|
+ VPTESTM %xmm0, %xmm0, %k2
|
|
+ VPCMP $0, %xmm1, %xmm0, %k1{%k2}
|
|
kmovd %k1, %ecx
|
|
# ifdef USE_AS_WCSCMP
|
|
- subl $0xff, %ecx
|
|
+ subl $0x3, %ecx
|
|
# else
|
|
- incl %ecx
|
|
+ incb %cl
|
|
# endif
|
|
- jne L(last_vector)
|
|
+ jnz L(check_ret_vec_page_cross)
|
|
|
|
- addl $VEC_SIZE, %edx
|
|
|
|
- addl $VEC_SIZE, %eax
|
|
# ifdef USE_AS_STRNCMP
|
|
- /* Return 0 if the current offset (%rdx) >= the maximum offset
|
|
- (%r11). */
|
|
- cmpq %r11, %rdx
|
|
- jae L(zero)
|
|
+ cmpq $(8 / SIZE_OF_CHAR), %rdx
|
|
+ jbe L(ret_zero_page_cross_slow_case0)
|
|
# endif
|
|
- cmpl $(PAGE_SIZE - VEC_SIZE), %eax
|
|
- jle L(loop_1_vector)
|
|
-L(cross_page_1_vector):
|
|
- /* Less than 32 bytes to check, try one xmm vector. */
|
|
- cmpl $(PAGE_SIZE - 16), %eax
|
|
- jg L(cross_page_1_xmm)
|
|
- VMOVU (%rdi, %rdx), %XMM0
|
|
+ movl $(24 / SIZE_OF_CHAR), %OFFSET_REG
|
|
+ subl %eax, %OFFSET_REG
|
|
|
|
- VPTESTM %YMM0, %YMM0, %k2
|
|
- /* Each bit cleared in K1 represents a mismatch or a null CHAR
|
|
- in XMM0 and 16 bytes at (%rsi, %rdx). */
|
|
- VPCMP $0, (%rsi, %rdx), %XMM0, %k1{%k2}
|
|
+ vmovq (%rdi, %OFFSET_REG64, SIZE_OF_CHAR), %xmm0
|
|
+ vmovq (%rsi, %OFFSET_REG64, SIZE_OF_CHAR), %xmm1
|
|
+ VPTESTM %xmm0, %xmm0, %k2
|
|
+ VPCMP $0, %xmm1, %xmm0, %k1{%k2}
|
|
kmovd %k1, %ecx
|
|
# ifdef USE_AS_WCSCMP
|
|
- subl $0xf, %ecx
|
|
+ subl $0x3, %ecx
|
|
# else
|
|
- subl $0xffff, %ecx
|
|
+ incb %cl
|
|
# endif
|
|
- jne L(last_vector)
|
|
+ jnz L(check_ret_vec_page_cross)
|
|
+
|
|
|
|
- addl $16, %edx
|
|
-# ifndef USE_AS_WCSCMP
|
|
- addl $16, %eax
|
|
-# endif
|
|
# ifdef USE_AS_STRNCMP
|
|
- /* Return 0 if the current offset (%rdx) >= the maximum offset
|
|
- (%r11). */
|
|
- cmpq %r11, %rdx
|
|
- jae L(zero)
|
|
+ addl $(8 / SIZE_OF_CHAR), %OFFSET_REG
|
|
+ subq %OFFSET_REG64, %rdx
|
|
+ jbe L(ret_zero_page_cross_slow_case0)
|
|
+ subq $-(CHAR_PER_VEC * 4), %rdx
|
|
+
|
|
+ leaq -(VEC_SIZE * 4)(%rdi, %OFFSET_REG64, SIZE_OF_CHAR), %rdi
|
|
+ leaq -(VEC_SIZE * 4)(%rsi, %OFFSET_REG64, SIZE_OF_CHAR), %rsi
|
|
+# else
|
|
+ leaq (8 - VEC_SIZE * 4)(%rdi, %OFFSET_REG64, SIZE_OF_CHAR), %rdi
|
|
+ leaq (8 - VEC_SIZE * 4)(%rsi, %OFFSET_REG64, SIZE_OF_CHAR), %rsi
|
|
# endif
|
|
+ jmp L(prepare_loop_aligned)
|
|
|
|
-L(cross_page_1_xmm):
|
|
-# ifndef USE_AS_WCSCMP
|
|
- /* Less than 16 bytes to check, try 8 byte vector. NB: No need
|
|
- for wcscmp nor wcsncmp since wide char is 4 bytes. */
|
|
- cmpl $(PAGE_SIZE - 8), %eax
|
|
- jg L(cross_page_8bytes)
|
|
- vmovq (%rdi, %rdx), %XMM0
|
|
- vmovq (%rsi, %rdx), %XMM1
|
|
|
|
- VPTESTM %YMM0, %YMM0, %k2
|
|
- /* Each bit cleared in K1 represents a mismatch or a null CHAR
|
|
- in XMM0 and XMM1. */
|
|
- VPCMP $0, %XMM1, %XMM0, %k1{%k2}
|
|
- kmovb %k1, %ecx
|
|
+
|
|
+
|
|
+ .p2align 4,, 10
|
|
+L(less_8_till_page):
|
|
# ifdef USE_AS_WCSCMP
|
|
- subl $0x3, %ecx
|
|
+ /* If using wchar then this is the only check before we reach
|
|
+ the page boundary. */
|
|
+ movl (%rdi), %eax
|
|
+ movl (%rsi), %ecx
|
|
+ cmpl %ecx, %eax
|
|
+ jnz L(ret_less_8_wcs)
|
|
+# ifdef USE_AS_STRNCMP
|
|
+ addq $-(CHAR_PER_VEC * 2), %rdx
|
|
+ /* We already checked for len <= 1 so cannot hit that case here.
|
|
+ */
|
|
+# endif
|
|
+ testl %eax, %eax
|
|
+ jnz L(prepare_loop)
|
|
+ ret
|
|
+
|
|
+ .p2align 4,, 8
|
|
+L(ret_less_8_wcs):
|
|
+ setl %OFFSET_REG8
|
|
+ negl %OFFSET_REG
|
|
+ movl %OFFSET_REG, %eax
|
|
+ xorl %r8d, %eax
|
|
+ ret
|
|
+
|
|
# else
|
|
- subl $0xff, %ecx
|
|
-# endif
|
|
- jne L(last_vector)
|
|
+ cmpl $28, %eax
|
|
+ ja L(less_4_till_page)
|
|
+
|
|
+ vmovd (%rdi), %xmm0
|
|
+ vmovd (%rsi), %xmm1
|
|
+ VPTESTM %xmm0, %xmm0, %k2
|
|
+ VPCMP $0, %xmm1, %xmm0, %k1{%k2}
|
|
+ kmovd %k1, %ecx
|
|
+ subl $0xf, %ecx
|
|
+ jnz L(check_ret_vec_page_cross)
|
|
|
|
- addl $8, %edx
|
|
- addl $8, %eax
|
|
# ifdef USE_AS_STRNCMP
|
|
- /* Return 0 if the current offset (%rdx) >= the maximum offset
|
|
- (%r11). */
|
|
- cmpq %r11, %rdx
|
|
- jae L(zero)
|
|
+ cmpq $4, %rdx
|
|
+ jbe L(ret_zero_page_cross_slow_case1)
|
|
# endif
|
|
+ movl $(28 / SIZE_OF_CHAR), %OFFSET_REG
|
|
+ subl %eax, %OFFSET_REG
|
|
|
|
-L(cross_page_8bytes):
|
|
- /* Less than 8 bytes to check, try 4 byte vector. */
|
|
- cmpl $(PAGE_SIZE - 4), %eax
|
|
- jg L(cross_page_4bytes)
|
|
- vmovd (%rdi, %rdx), %XMM0
|
|
- vmovd (%rsi, %rdx), %XMM1
|
|
-
|
|
- VPTESTM %YMM0, %YMM0, %k2
|
|
- /* Each bit cleared in K1 represents a mismatch or a null CHAR
|
|
- in XMM0 and XMM1. */
|
|
- VPCMP $0, %XMM1, %XMM0, %k1{%k2}
|
|
+ vmovd (%rdi, %OFFSET_REG64, SIZE_OF_CHAR), %xmm0
|
|
+ vmovd (%rsi, %OFFSET_REG64, SIZE_OF_CHAR), %xmm1
|
|
+ VPTESTM %xmm0, %xmm0, %k2
|
|
+ VPCMP $0, %xmm1, %xmm0, %k1{%k2}
|
|
kmovd %k1, %ecx
|
|
-# ifdef USE_AS_WCSCMP
|
|
- subl $0x1, %ecx
|
|
-# else
|
|
subl $0xf, %ecx
|
|
-# endif
|
|
- jne L(last_vector)
|
|
+ jnz L(check_ret_vec_page_cross)
|
|
+# ifdef USE_AS_STRNCMP
|
|
+ addl $(4 / SIZE_OF_CHAR), %OFFSET_REG
|
|
+ subq %OFFSET_REG64, %rdx
|
|
+ jbe L(ret_zero_page_cross_slow_case1)
|
|
+ subq $-(CHAR_PER_VEC * 4), %rdx
|
|
+
|
|
+ leaq -(VEC_SIZE * 4)(%rdi, %OFFSET_REG64, SIZE_OF_CHAR), %rdi
|
|
+ leaq -(VEC_SIZE * 4)(%rsi, %OFFSET_REG64, SIZE_OF_CHAR), %rsi
|
|
+# else
|
|
+ leaq (4 - VEC_SIZE * 4)(%rdi, %OFFSET_REG64, SIZE_OF_CHAR), %rdi
|
|
+ leaq (4 - VEC_SIZE * 4)(%rsi, %OFFSET_REG64, SIZE_OF_CHAR), %rsi
|
|
+# endif
|
|
+ jmp L(prepare_loop_aligned)
|
|
+
|
|
|
|
- addl $4, %edx
|
|
# ifdef USE_AS_STRNCMP
|
|
- /* Return 0 if the current offset (%rdx) >= the maximum offset
|
|
- (%r11). */
|
|
- cmpq %r11, %rdx
|
|
- jae L(zero)
|
|
+ .p2align 4,, 2
|
|
+L(ret_zero_page_cross_slow_case1):
|
|
+ xorl %eax, %eax
|
|
+ ret
|
|
# endif
|
|
|
|
-L(cross_page_4bytes):
|
|
-# endif
|
|
- /* Less than 4 bytes to check, try one byte/dword at a time. */
|
|
-# ifdef USE_AS_STRNCMP
|
|
- cmpq %r11, %rdx
|
|
- jae L(zero)
|
|
-# endif
|
|
-# ifdef USE_AS_WCSCMP
|
|
- movl (%rdi, %rdx), %eax
|
|
- movl (%rsi, %rdx), %ecx
|
|
-# else
|
|
- movzbl (%rdi, %rdx), %eax
|
|
- movzbl (%rsi, %rdx), %ecx
|
|
-# endif
|
|
- testl %eax, %eax
|
|
- jne L(cross_page_loop)
|
|
+ .p2align 4,, 10
|
|
+L(less_4_till_page):
|
|
+ subq %rdi, %rsi
|
|
+ /* Extremely slow byte comparison loop. */
|
|
+L(less_4_loop):
|
|
+ movzbl (%rdi), %eax
|
|
+ movzbl (%rsi, %rdi), %ecx
|
|
subl %ecx, %eax
|
|
+ jnz L(ret_less_4_loop)
|
|
+ testl %ecx, %ecx
|
|
+ jz L(ret_zero_4_loop)
|
|
+# ifdef USE_AS_STRNCMP
|
|
+ decq %rdx
|
|
+ jz L(ret_zero_4_loop)
|
|
+# endif
|
|
+ incq %rdi
|
|
+ /* end condition is reach page boundary (rdi is aligned). */
|
|
+ testl $31, %edi
|
|
+ jnz L(less_4_loop)
|
|
+ leaq -(VEC_SIZE * 4)(%rdi, %rsi), %rsi
|
|
+ addq $-(VEC_SIZE * 4), %rdi
|
|
+# ifdef USE_AS_STRNCMP
|
|
+ subq $-(CHAR_PER_VEC * 4), %rdx
|
|
+# endif
|
|
+ jmp L(prepare_loop_aligned)
|
|
+
|
|
+L(ret_zero_4_loop):
|
|
+ xorl %eax, %eax
|
|
+ ret
|
|
+L(ret_less_4_loop):
|
|
+ xorl %r8d, %eax
|
|
+ subl %r8d, %eax
|
|
ret
|
|
-END (STRCMP)
|
|
+# endif
|
|
+END(STRCMP)
|
|
#endif
|