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93 lines
2.2 KiB
ArmAsm
93 lines
2.2 KiB
ArmAsm
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/* Highly optimized version for x86-64.
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Copyright (C) 1997, 2000, 2002 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Based on i586 version contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
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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, write to the Free
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Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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02111-1307 USA. */
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#include <sysdep.h>
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#include "asm-syntax.h"
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#include "bp-sym.h"
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#include "bp-asm.h"
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/* BEWARE: `#ifdef memcpy' means that memcpy is redefined as `mempcpy',
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and the return value is the byte after the last one copied in
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the destination. */
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#define MEMPCPY_P (defined memcpy)
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.text
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ENTRY (BP_SYM (memcpy))
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/* Cutoff for the big loop is a size of 32 bytes since otherwise
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the loop will never be entered. */
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cmpq $32, %rdx
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movq %rdx, %rcx
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#if !MEMPCPY_P
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movq %rdi, %r10 /* Save value. */
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#endif
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/* We need this in any case. */
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cld
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jbe 1f
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/* Align destination. */
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movq %rdi, %rax
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negq %rax
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andq $3, %rax
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subq %rax, %rcx
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xchgq %rax, %rcx
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rep; movsb
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movq %rax, %rcx
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subq $32, %rcx
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js 2f
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.p2align 4
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3:
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/* Now correct the loop counter. Please note that in the following
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code the flags are not changed anymore. */
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subq $32, %rcx
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movq (%rsi), %rax
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movq 8(%rsi), %rdx
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movq 16(%rsi), %r8
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movq 24(%rsi), %r9
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movq %rax, (%rdi)
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movq %rdx, 8(%rdi)
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movq %r8, 16(%rdi)
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movq %r9, 24(%rdi)
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leaq 32(%rsi), %rsi
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leaq 32(%rdi), %rdi
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jns 3b
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/* Correct extra loop counter modification. */
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2: addq $32, %rcx
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1: rep; movsb
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#if MEMPCPY_P
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movq %rdi, %rax /* Set return value. */
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#else
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movq %r10, %rax /* Set return value. */
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#endif
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ret
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END (BP_SYM (memcpy))
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