7f02ce62a6
This is to get the changes from:68674f94ff("x86: don't use REP_GOOD or ERMS for small memory copies")20f3337d35("x86: don't use REP_GOOD or ERMS for small memory clearing") This also make the 'perf bench mem' files stop referring to the erms versions that gone away with the above patches. That addresses these perf tools build warning: Warning: Kernel ABI header at 'tools/arch/x86/lib/memcpy_64.S' differs from latest version at 'arch/x86/lib/memcpy_64.S' diff -u tools/arch/x86/lib/memcpy_64.S arch/x86/lib/memcpy_64.S Warning: Kernel ABI header at 'tools/arch/x86/lib/memset_64.S' differs from latest version at 'arch/x86/lib/memset_64.S' diff -u tools/arch/x86/lib/memset_64.S arch/x86/lib/memset_64.S Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
171 lines
3.3 KiB
ArmAsm
171 lines
3.3 KiB
ArmAsm
/* SPDX-License-Identifier: GPL-2.0-only */
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/* Copyright 2002 Andi Kleen */
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#include <linux/linkage.h>
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#include <asm/errno.h>
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#include <asm/cpufeatures.h>
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#include <asm/alternative.h>
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#include <asm/export.h>
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.section .noinstr.text, "ax"
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/*
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* memcpy - Copy a memory block.
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*
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* Input:
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* rdi destination
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* rsi source
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* rdx count
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*
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* Output:
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* rax original destination
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*
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* The FSRM alternative should be done inline (avoiding the call and
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* the disgusting return handling), but that would require some help
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* from the compiler for better calling conventions.
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*
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* The 'rep movsb' itself is small enough to replace the call, but the
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* two register moves blow up the code. And one of them is "needed"
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* only for the return value that is the same as the source input,
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* which the compiler could/should do much better anyway.
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*/
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SYM_TYPED_FUNC_START(__memcpy)
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ALTERNATIVE "jmp memcpy_orig", "", X86_FEATURE_FSRM
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movq %rdi, %rax
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movq %rdx, %rcx
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rep movsb
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RET
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SYM_FUNC_END(__memcpy)
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EXPORT_SYMBOL(__memcpy)
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SYM_FUNC_ALIAS(memcpy, __memcpy)
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EXPORT_SYMBOL(memcpy)
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SYM_FUNC_START_LOCAL(memcpy_orig)
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movq %rdi, %rax
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cmpq $0x20, %rdx
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jb .Lhandle_tail
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/*
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* We check whether memory false dependence could occur,
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* then jump to corresponding copy mode.
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*/
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cmp %dil, %sil
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jl .Lcopy_backward
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subq $0x20, %rdx
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.Lcopy_forward_loop:
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subq $0x20, %rdx
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/*
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* Move in blocks of 4x8 bytes:
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*/
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movq 0*8(%rsi), %r8
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movq 1*8(%rsi), %r9
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movq 2*8(%rsi), %r10
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movq 3*8(%rsi), %r11
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leaq 4*8(%rsi), %rsi
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movq %r8, 0*8(%rdi)
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movq %r9, 1*8(%rdi)
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movq %r10, 2*8(%rdi)
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movq %r11, 3*8(%rdi)
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leaq 4*8(%rdi), %rdi
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jae .Lcopy_forward_loop
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addl $0x20, %edx
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jmp .Lhandle_tail
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.Lcopy_backward:
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/*
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* Calculate copy position to tail.
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*/
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addq %rdx, %rsi
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addq %rdx, %rdi
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subq $0x20, %rdx
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/*
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* At most 3 ALU operations in one cycle,
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* so append NOPS in the same 16 bytes trunk.
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*/
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.p2align 4
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.Lcopy_backward_loop:
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subq $0x20, %rdx
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movq -1*8(%rsi), %r8
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movq -2*8(%rsi), %r9
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movq -3*8(%rsi), %r10
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movq -4*8(%rsi), %r11
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leaq -4*8(%rsi), %rsi
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movq %r8, -1*8(%rdi)
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movq %r9, -2*8(%rdi)
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movq %r10, -3*8(%rdi)
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movq %r11, -4*8(%rdi)
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leaq -4*8(%rdi), %rdi
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jae .Lcopy_backward_loop
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/*
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* Calculate copy position to head.
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*/
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addl $0x20, %edx
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subq %rdx, %rsi
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subq %rdx, %rdi
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.Lhandle_tail:
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cmpl $16, %edx
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jb .Lless_16bytes
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/*
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* Move data from 16 bytes to 31 bytes.
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*/
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movq 0*8(%rsi), %r8
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movq 1*8(%rsi), %r9
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movq -2*8(%rsi, %rdx), %r10
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movq -1*8(%rsi, %rdx), %r11
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movq %r8, 0*8(%rdi)
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movq %r9, 1*8(%rdi)
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movq %r10, -2*8(%rdi, %rdx)
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movq %r11, -1*8(%rdi, %rdx)
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RET
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.p2align 4
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.Lless_16bytes:
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cmpl $8, %edx
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jb .Lless_8bytes
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/*
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* Move data from 8 bytes to 15 bytes.
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*/
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movq 0*8(%rsi), %r8
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movq -1*8(%rsi, %rdx), %r9
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movq %r8, 0*8(%rdi)
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movq %r9, -1*8(%rdi, %rdx)
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RET
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.p2align 4
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.Lless_8bytes:
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cmpl $4, %edx
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jb .Lless_3bytes
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/*
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* Move data from 4 bytes to 7 bytes.
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*/
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movl (%rsi), %ecx
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movl -4(%rsi, %rdx), %r8d
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movl %ecx, (%rdi)
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movl %r8d, -4(%rdi, %rdx)
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RET
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.p2align 4
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.Lless_3bytes:
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subl $1, %edx
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jb .Lend
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/*
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* Move data from 1 bytes to 3 bytes.
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*/
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movzbl (%rsi), %ecx
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jz .Lstore_1byte
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movzbq 1(%rsi), %r8
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movzbq (%rsi, %rdx), %r9
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movb %r8b, 1(%rdi)
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movb %r9b, (%rdi, %rdx)
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.Lstore_1byte:
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movb %cl, (%rdi)
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.Lend:
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RET
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SYM_FUNC_END(memcpy_orig)
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