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8ea20ee5f6
Clear the upper 32 bits in RDX (memory size) for x32 to fix FAIL: string/tst-size_t-memcmp FAIL: string/tst-size_t-memcmp-2 FAIL: string/tst-size_t-memcpy FAIL: wcsmbs/tst-size_t-wmemcmp on x32 introduced by8804157ad9x86: Optimize memcmp SSE2 in memcmp.S26b2478322x86: Reduce code size of mem{move|pcpy|cpy}-ssse3 Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
579 lines
13 KiB
ArmAsm
579 lines
13 KiB
ArmAsm
/* memcmp with SSE2
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Copyright (C) 2009-2022 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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#include <sysdep.h>
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#ifdef USE_AS_WMEMCMP
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# define PCMPEQ pcmpeqd
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# define CHAR_SIZE 4
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# define SIZE_OFFSET (0)
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#else
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# define PCMPEQ pcmpeqb
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# define CHAR_SIZE 1
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#endif
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#ifdef USE_AS_MEMCMPEQ
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# define SIZE_OFFSET (0)
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# define CHECK_CMP(x, y) subl x, y
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#else
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# ifndef SIZE_OFFSET
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# define SIZE_OFFSET (CHAR_PER_VEC * 2)
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# endif
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# define CHECK_CMP(x, y) cmpl x, y
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#endif
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#define VEC_SIZE 16
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#define CHAR_PER_VEC (VEC_SIZE / CHAR_SIZE)
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#ifndef MEMCMP
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# define MEMCMP memcmp
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#endif
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.text
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ENTRY(MEMCMP)
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# ifdef __ILP32__
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/* Clear the upper 32 bits. */
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movl %edx, %edx
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# endif
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#ifdef USE_AS_WMEMCMP
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/* Use 0xffff to test for mismatches on pmovmskb bitmask. Store
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in ecx for code size. This is preferable to using `incw` as
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it avoids partial register stalls on older hardware (pre
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SnB). */
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movl $0xffff, %ecx
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#endif
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cmpq $CHAR_PER_VEC, %rdx
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ja L(more_1x_vec)
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#ifdef USE_AS_WMEMCMP
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/* saves a byte of code keeping the fall through path n = [2, 4]
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in the initial cache line. */
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decl %edx
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jle L(cmp_0_1)
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movq (%rsi), %xmm0
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movq (%rdi), %xmm1
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PCMPEQ %xmm0, %xmm1
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pmovmskb %xmm1, %eax
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subl %ecx, %eax
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jnz L(ret_nonzero_vec_start_0)
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movq -4(%rsi, %rdx, CHAR_SIZE), %xmm0
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movq -4(%rdi, %rdx, CHAR_SIZE), %xmm1
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PCMPEQ %xmm0, %xmm1
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pmovmskb %xmm1, %eax
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subl %ecx, %eax
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jnz L(ret_nonzero_vec_end_0_adj)
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#else
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cmpl $8, %edx
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ja L(cmp_9_16)
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cmpl $4, %edx
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jb L(cmp_0_3)
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# ifdef USE_AS_MEMCMPEQ
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movl (%rsi), %eax
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subl (%rdi), %eax
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movl -4(%rsi, %rdx), %esi
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subl -4(%rdi, %rdx), %esi
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orl %esi, %eax
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ret
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# else
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/* Combine comparisons for lo and hi 4-byte comparisons. */
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movl -4(%rsi, %rdx), %ecx
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movl -4(%rdi, %rdx), %eax
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shlq $32, %rcx
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shlq $32, %rax
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movl (%rsi), %esi
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movl (%rdi), %edi
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orq %rsi, %rcx
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orq %rdi, %rax
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/* Only compute proper return if not-equal. */
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cmpq %rcx, %rax
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jnz L(ret_nonzero)
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xorl %eax, %eax
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ret
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# endif
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.p2align 4,, 10
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L(cmp_9_16):
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# ifdef USE_AS_MEMCMPEQ
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movq (%rsi), %rax
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subq (%rdi), %rax
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movq -8(%rsi, %rdx), %rcx
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subq -8(%rdi, %rdx), %rcx
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orq %rcx, %rax
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/* Convert 64 bit -> 32 bit boolean (we should have made the ABI
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return long). */
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setnz %cl
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movzbl %cl, %eax
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# else
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movq (%rsi), %rcx
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movq (%rdi), %rax
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/* Only compute proper return if not-equal. */
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cmpq %rcx, %rax
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jnz L(ret_nonzero)
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movq -8(%rsi, %rdx, CHAR_SIZE), %rcx
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movq -8(%rdi, %rdx, CHAR_SIZE), %rax
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/* Only compute proper return if not-equal. */
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cmpq %rcx, %rax
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jnz L(ret_nonzero)
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xorl %eax, %eax
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# endif
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#endif
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ret
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.p2align 4,, 8
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L(cmp_0_1):
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/* Flag set by earlier comparison against 1. */
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jne L(cmp_0_0)
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#ifdef USE_AS_WMEMCMP
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movl (%rdi), %ecx
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xorl %edx, %edx
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cmpl (%rsi), %ecx
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je L(cmp_0_0)
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setg %dl
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leal -1(%rdx, %rdx), %eax
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#else
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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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ret
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/* Fits in aligning bytes. */
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L(cmp_0_0):
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xorl %eax, %eax
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ret
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#ifdef USE_AS_WMEMCMP
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.p2align 4
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L(ret_nonzero_vec_start_0):
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bsfl %eax, %eax
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movl (%rdi, %rax), %ecx
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xorl %edx, %edx
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cmpl (%rsi, %rax), %ecx
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/* NB: no partial register stall here because xorl zero idiom
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above. */
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setg %dl
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leal -1(%rdx, %rdx), %eax
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ret
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#else
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# ifndef USE_AS_MEMCMPEQ
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.p2align 4,, 14
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L(ret_nonzero):
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/* Need to bswap to get proper return without branch. */
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bswapq %rcx
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bswapq %rax
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subq %rcx, %rax
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sbbl %eax, %eax
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orl $1, %eax
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ret
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# endif
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.p2align 4
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L(cmp_0_3):
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# ifdef USE_AS_MEMCMPEQ
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/* No reason to add to dependency chain on rdx. Saving a the
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bytes here doesn't change number of fetch blocks. */
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cmpl $1, %edx
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jbe L(cmp_0_1)
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# else
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/* We need the code size to prevent taking an extra fetch block.
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*/
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decl %edx
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jle L(cmp_0_1)
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# endif
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movzwl (%rsi), %ecx
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movzwl (%rdi), %eax
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# ifdef USE_AS_MEMCMPEQ
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subl %ecx, %eax
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movzbl -1(%rsi, %rdx), %esi
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movzbl -1(%rdi, %rdx), %edi
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subl %edi, %esi
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orl %esi, %eax
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# else
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bswapl %ecx
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bswapl %eax
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/* Implicit right shift by one. We just need to displace the
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sign bits. */
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shrl %ecx
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shrl %eax
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/* Eat a partial register stall here. Saves code stopping
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L(cmp_0_3) from bleeding into the next fetch block and saves
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an ALU. */
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movb (%rsi, %rdx), %cl
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movzbl (%rdi, %rdx), %edi
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orl %edi, %eax
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subl %ecx, %eax
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# endif
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ret
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#endif
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.p2align 5
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L(more_1x_vec):
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#ifndef USE_AS_WMEMCMP
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/* Use 0xffff to test for mismatches on pmovmskb bitmask. Store
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in ecx for code size. This is preferable to using `incw` as
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it avoids partial register stalls on older hardware (pre
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SnB). */
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movl $0xffff, %ecx
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#endif
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movups (%rsi), %xmm0
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movups (%rdi), %xmm1
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PCMPEQ %xmm0, %xmm1
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pmovmskb %xmm1, %eax
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subl %ecx, %eax
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jnz L(ret_nonzero_vec_start_0)
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#if SIZE_OFFSET == 0
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cmpq $(CHAR_PER_VEC * 2), %rdx
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#else
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/* Offset rdx. Saves just enough code size to keep the
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L(last_2x_vec) case and the non-zero return in a single
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cache line. */
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subq $(CHAR_PER_VEC * 2), %rdx
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#endif
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ja L(more_2x_vec)
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movups (VEC_SIZE * -1 + SIZE_OFFSET)(%rsi, %rdx, CHAR_SIZE), %xmm0
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movups (VEC_SIZE * -1 + SIZE_OFFSET)(%rdi, %rdx, CHAR_SIZE), %xmm1
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PCMPEQ %xmm0, %xmm1
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pmovmskb %xmm1, %eax
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subl %ecx, %eax
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#ifndef USE_AS_MEMCMPEQ
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/* Don't use `incw ax` as machines this code runs on are liable
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to have partial register stall. */
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jnz L(ret_nonzero_vec_end_0)
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#else
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/* Various return targets for memcmpeq. Will always be hot in
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Icache and get short encoding. */
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L(ret_nonzero_vec_start_1):
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L(ret_nonzero_vec_start_0):
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L(ret_nonzero_vec_end_0):
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#endif
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ret
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#ifndef USE_AS_MEMCMPEQ
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# ifdef USE_AS_WMEMCMP
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.p2align 4
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L(ret_nonzero_vec_end_0_adj):
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addl $3, %edx
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# else
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.p2align 4,, 8
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# endif
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L(ret_nonzero_vec_end_0):
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bsfl %eax, %eax
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# ifdef USE_AS_WMEMCMP
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leal (%rax, %rdx, CHAR_SIZE), %eax
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movl (VEC_SIZE * -1 + SIZE_OFFSET)(%rdi, %rax), %ecx
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xorl %edx, %edx
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cmpl (VEC_SIZE * -1 + SIZE_OFFSET)(%rsi, %rax), %ecx
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/* NB: no partial register stall here because xorl zero idiom
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above. */
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setg %dl
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leal -1(%rdx, %rdx), %eax
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# else
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addl %edx, %eax
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movzbl (VEC_SIZE * -1 + SIZE_OFFSET)(%rsi, %rax), %ecx
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movzbl (VEC_SIZE * -1 + SIZE_OFFSET)(%rdi, %rax), %eax
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subl %ecx, %eax
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# endif
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ret
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# ifndef USE_AS_WMEMCMP
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.p2align 4,, 10
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L(ret_nonzero_vec_start_0):
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bsfl %eax, %eax
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movzbl (%rsi, %rax), %ecx
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movzbl (%rdi, %rax), %eax
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subl %ecx, %eax
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ret
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# endif
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#else
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#endif
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.p2align 5
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L(more_2x_vec):
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movups (VEC_SIZE * 1)(%rsi), %xmm0
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movups (VEC_SIZE * 1)(%rdi), %xmm1
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PCMPEQ %xmm0, %xmm1
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pmovmskb %xmm1, %eax
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subl %ecx, %eax
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jnz L(ret_nonzero_vec_start_1)
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cmpq $(CHAR_PER_VEC * 4 - SIZE_OFFSET), %rdx
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jbe L(last_2x_vec)
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cmpq $(CHAR_PER_VEC * 8 - SIZE_OFFSET), %rdx
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ja L(more_8x_vec)
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/* Do comparisons for [65, 96] and [97, 128] 2x VEC at a time.
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This can harm performance if non-zero return in [65, 80] or
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[97, 112] but helps performance otherwise. Generally zero-
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return is hotter. */
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movups (VEC_SIZE * 2)(%rsi), %xmm0
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movups (VEC_SIZE * 2)(%rdi), %xmm1
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PCMPEQ %xmm0, %xmm1
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movups (VEC_SIZE * 3)(%rsi), %xmm2
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movups (VEC_SIZE * 3)(%rdi), %xmm3
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PCMPEQ %xmm2, %xmm3
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pand %xmm1, %xmm3
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pmovmskb %xmm3, %eax
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CHECK_CMP (%ecx, %eax)
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jnz L(ret_nonzero_vec_start_2_3)
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cmpl $(CHAR_PER_VEC * 6 - SIZE_OFFSET), %edx
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jbe L(last_2x_vec)
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movups (VEC_SIZE * 4)(%rsi), %xmm0
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movups (VEC_SIZE * 4)(%rdi), %xmm1
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PCMPEQ %xmm0, %xmm1
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movups (VEC_SIZE * 5)(%rsi), %xmm2
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movups (VEC_SIZE * 5)(%rdi), %xmm3
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PCMPEQ %xmm2, %xmm3
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pand %xmm1, %xmm3
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pmovmskb %xmm3, %eax
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CHECK_CMP (%ecx, %eax)
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#ifdef USE_AS_MEMCMPEQ
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jz L(last_2x_vec)
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ret
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#else
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jnz L(ret_nonzero_vec_start_4_5)
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#endif
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.p2align 4
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L(last_2x_vec):
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movups (VEC_SIZE * -2 + SIZE_OFFSET)(%rsi, %rdx, CHAR_SIZE), %xmm0
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movups (VEC_SIZE * -2 + SIZE_OFFSET)(%rdi, %rdx, CHAR_SIZE), %xmm1
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PCMPEQ %xmm0, %xmm1
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movups (VEC_SIZE * -1 + SIZE_OFFSET)(%rsi, %rdx, CHAR_SIZE), %xmm2
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movups (VEC_SIZE * -1 + SIZE_OFFSET)(%rdi, %rdx, CHAR_SIZE), %xmm3
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PCMPEQ %xmm2, %xmm3
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pand %xmm1, %xmm3
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pmovmskb %xmm3, %eax
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subl %ecx, %eax
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#ifdef USE_AS_MEMCMPEQ
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/* Various return targets for memcmpeq. Will always be hot in
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Icache and get short encoding. */
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L(ret_nonzero_vec_start_2_3):
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L(ret_nonzero_vec_start_4_5):
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ret
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#else
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jnz L(ret_nonzero_vec_end_1)
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ret
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.p2align 4,, 8
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L(ret_nonzero_vec_end_1):
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pmovmskb %xmm1, %ecx
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/* High 16 bits of eax guranteed to be all ones. Rotate them in
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to we can do `or + not` with just `xor`. */
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rorl $16, %eax
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xorl %ecx, %eax
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/* Partial register stall. */
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bsfl %eax, %eax
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# ifdef USE_AS_WMEMCMP
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leal (%rax, %rdx, CHAR_SIZE), %eax
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movl (VEC_SIZE * -2 + SIZE_OFFSET)(%rdi, %rax), %ecx
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xorl %edx, %edx
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cmpl (VEC_SIZE * -2 + SIZE_OFFSET)(%rsi, %rax), %ecx
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/* NB: no partial register stall here because xorl zero idiom
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above. */
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setg %dl
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leal -1(%rdx, %rdx), %eax
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# else
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addl %edx, %eax
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movzbl (VEC_SIZE * -2 + SIZE_OFFSET)(%rsi, %rax), %ecx
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movzbl (VEC_SIZE * -2 + SIZE_OFFSET)(%rdi, %rax), %eax
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subl %ecx, %eax
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# endif
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ret
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.p2align 4
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L(ret_nonzero_vec_start_4_5):
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pmovmskb %xmm1, %edx
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sall $16, %eax
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leal 1(%rax, %rdx), %eax
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bsfl %eax, %eax
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# ifdef USE_AS_WMEMCMP
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movl (VEC_SIZE * 4)(%rdi, %rax), %ecx
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xorl %edx, %edx
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cmpl (VEC_SIZE * 4)(%rsi, %rax), %ecx
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/* NB: no partial register stall here because xorl zero idiom
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above. */
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setg %dl
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leal -1(%rdx, %rdx), %eax
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# else
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movzbl (VEC_SIZE * 4)(%rsi, %rax), %ecx
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movzbl (VEC_SIZE * 4)(%rdi, %rax), %eax
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subl %ecx, %eax
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# endif
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ret
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.p2align 4,, 8
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L(ret_nonzero_vec_start_1):
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bsfl %eax, %eax
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# ifdef USE_AS_WMEMCMP
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movl (VEC_SIZE * 1)(%rdi, %rax), %ecx
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xorl %edx, %edx
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cmpl (VEC_SIZE * 1)(%rsi, %rax), %ecx
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/* NB: no partial register stall here because xorl zero idiom
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above. */
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setg %dl
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leal -1(%rdx, %rdx), %eax
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# else
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movzbl (VEC_SIZE * 1)(%rsi, %rax), %ecx
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movzbl (VEC_SIZE * 1)(%rdi, %rax), %eax
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subl %ecx, %eax
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# endif
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ret
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#endif
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.p2align 4
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L(more_8x_vec):
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subq %rdi, %rsi
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leaq (VEC_SIZE * -6 + SIZE_OFFSET)(%rdi, %rdx, CHAR_SIZE), %rdx
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andq $(VEC_SIZE * -1), %rdi
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addq %rdi, %rsi
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.p2align 4
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L(loop_4x):
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movups (VEC_SIZE * 2)(%rsi), %xmm0
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movups (VEC_SIZE * 3)(%rsi), %xmm1
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PCMPEQ (VEC_SIZE * 2)(%rdi), %xmm0
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PCMPEQ (VEC_SIZE * 3)(%rdi), %xmm1
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movups (VEC_SIZE * 4)(%rsi), %xmm2
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movups (VEC_SIZE * 5)(%rsi), %xmm3
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PCMPEQ (VEC_SIZE * 4)(%rdi), %xmm2
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PCMPEQ (VEC_SIZE * 5)(%rdi), %xmm3
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|
|
pand %xmm0, %xmm1
|
|
pand %xmm2, %xmm3
|
|
pand %xmm1, %xmm3
|
|
|
|
pmovmskb %xmm3, %eax
|
|
subl %ecx, %eax
|
|
jnz L(ret_nonzero_loop)
|
|
|
|
addq $(VEC_SIZE * 4), %rdi
|
|
addq $(VEC_SIZE * 4), %rsi
|
|
cmpq %rdi, %rdx
|
|
ja L(loop_4x)
|
|
/* Get remaining length in edx. */
|
|
subl %edi, %edx
|
|
/* Restore offset so we can reuse L(last_2x_vec). */
|
|
addl $(VEC_SIZE * 6 - SIZE_OFFSET), %edx
|
|
#ifdef USE_AS_WMEMCMP
|
|
shrl $2, %edx
|
|
#endif
|
|
cmpl $(CHAR_PER_VEC * 4 - SIZE_OFFSET), %edx
|
|
jbe L(last_2x_vec)
|
|
|
|
|
|
movups (VEC_SIZE * 2)(%rsi), %xmm0
|
|
movups (VEC_SIZE * 2)(%rdi), %xmm1
|
|
PCMPEQ %xmm0, %xmm1
|
|
movups (VEC_SIZE * 3)(%rsi), %xmm2
|
|
movups (VEC_SIZE * 3)(%rdi), %xmm3
|
|
PCMPEQ %xmm2, %xmm3
|
|
pand %xmm1, %xmm3
|
|
|
|
pmovmskb %xmm3, %eax
|
|
CHECK_CMP (%ecx, %eax)
|
|
jz L(last_2x_vec)
|
|
#ifdef USE_AS_MEMCMPEQ
|
|
L(ret_nonzero_loop):
|
|
ret
|
|
#else
|
|
|
|
.p2align 4
|
|
L(ret_nonzero_vec_start_2_3):
|
|
pmovmskb %xmm1, %edx
|
|
sall $16, %eax
|
|
leal 1(%rax, %rdx), %eax
|
|
|
|
bsfl %eax, %eax
|
|
# ifdef USE_AS_WMEMCMP
|
|
movl (VEC_SIZE * 2)(%rdi, %rax), %ecx
|
|
xorl %edx, %edx
|
|
cmpl (VEC_SIZE * 2)(%rsi, %rax), %ecx
|
|
/* NB: no partial register stall here because xorl zero idiom
|
|
above. */
|
|
setg %dl
|
|
leal -1(%rdx, %rdx), %eax
|
|
# else
|
|
movzbl (VEC_SIZE * 2)(%rsi, %rax), %ecx
|
|
movzbl (VEC_SIZE * 2)(%rdi, %rax), %eax
|
|
subl %ecx, %eax
|
|
# endif
|
|
ret
|
|
|
|
.p2align 4
|
|
L(ret_nonzero_loop):
|
|
pmovmskb %xmm0, %ecx
|
|
pmovmskb %xmm1, %edx
|
|
sall $(VEC_SIZE * 1), %edx
|
|
leal 1(%rcx, %rdx), %edx
|
|
pmovmskb %xmm2, %ecx
|
|
/* High 16 bits of eax guranteed to be all ones. Rotate them in
|
|
to we can do `or + not` with just `xor`. */
|
|
rorl $16, %eax
|
|
xorl %ecx, %eax
|
|
|
|
salq $32, %rax
|
|
orq %rdx, %rax
|
|
|
|
bsfq %rax, %rax
|
|
# ifdef USE_AS_WMEMCMP
|
|
movl (VEC_SIZE * 2)(%rdi, %rax), %ecx
|
|
xorl %edx, %edx
|
|
cmpl (VEC_SIZE * 2)(%rsi, %rax), %ecx
|
|
/* NB: no partial register stall here because xorl zero idiom
|
|
above. */
|
|
setg %dl
|
|
leal -1(%rdx, %rdx), %eax
|
|
# else
|
|
movzbl (VEC_SIZE * 2)(%rsi, %rax), %ecx
|
|
movzbl (VEC_SIZE * 2)(%rdi, %rax), %eax
|
|
subl %ecx, %eax
|
|
# endif
|
|
ret
|
|
#endif
|
|
END(MEMCMP)
|
|
|
|
#ifndef USE_AS_WMEMCMP
|
|
# ifdef USE_AS_MEMCMPEQ
|
|
libc_hidden_def (MEMCMP)
|
|
# else
|
|
# undef bcmp
|
|
weak_alias (MEMCMP, bcmp)
|
|
libc_hidden_builtin_def (MEMCMP)
|
|
# endif
|
|
#endif
|