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/* Copyright (C) 2006, 2008, 2009 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by MontaVista Software, Inc. (written by Nicolas Pitre)
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library. If not, see
<http://www.gnu.org/licenses/>. */
#include <sysdep.h>
/*
* Data preload for architectures that support it (ARM V5TE and above)
*/
#if (!defined (__ARM_ARCH_2__) && !defined (__ARM_ARCH_3__) \
&& !defined (__ARM_ARCH_3M__) && !defined (__ARM_ARCH_4__) \
&& !defined (__ARM_ARCH_4T__) && !defined (__ARM_ARCH_5__) \
&& !defined (__ARM_ARCH_5T__))
#define PLD(code...) code
#else
#define PLD(code...)
#endif
/*
* This can be used to enable code to cacheline align the source pointer.
* Experiments on tested architectures (StrongARM and XScale) didn't show
* this a worthwhile thing to do. That might be different in the future.
*/
//#define CALGN(code...) code
#define CALGN(code...)
/*
* Endian independent macros for shifting bytes within registers.
*/
#ifndef __ARMEB__
#define pull lsr
#define push lsl
#else
#define pull lsl
#define push lsr
#endif
.text
/*
* Prototype: void *memmove(void *dest, const void *src, size_t n);
*
* Note:
*
* If the memory regions don't overlap, we simply branch to memcpy which is
* normally a bit faster. Otherwise the copy is done going downwards.
*/
ENTRY(memmove)
subs ip, r0, r1
cmphi r2, ip
#ifdef NOT_IN_libc
bls memcpy
#else
bls HIDDEN_JUMPTARGET(memcpy)
#endif
stmfd sp!, {r0, r4, lr}
cfi_adjust_cfa_offset (12)
cfi_rel_offset (r4, 4)
cfi_rel_offset (lr, 8)
cfi_remember_state
add r1, r1, r2
add r0, r0, r2
subs r2, r2, #4
blt 8f
ands ip, r0, #3
PLD( pld [r1, #-4] )
bne 9f
ands ip, r1, #3
bne 10f
1: subs r2, r2, #(28)
stmfd sp!, {r5 - r8}
cfi_adjust_cfa_offset (16)
cfi_rel_offset (r5, 0)
cfi_rel_offset (r6, 4)
cfi_rel_offset (r7, 8)
cfi_rel_offset (r8, 12)
blt 5f
CALGN( ands ip, r1, #31 )
CALGN( sbcnes r4, ip, r2 ) @ C is always set here
CALGN( bcs 2f )
CALGN( adr r4, 6f )
CALGN( subs r2, r2, ip ) @ C is set here
CALGN( add pc, r4, ip )
PLD( pld [r1, #-4] )
2: PLD( subs r2, r2, #96 )
PLD( pld [r1, #-32] )
PLD( blt 4f )
PLD( pld [r1, #-64] )
PLD( pld [r1, #-96] )
3: PLD( pld [r1, #-128] )
4: ldmdb r1!, {r3, r4, r5, r6, r7, r8, ip, lr}
subs r2, r2, #32
stmdb r0!, {r3, r4, r5, r6, r7, r8, ip, lr}
bge 3b
PLD( cmn r2, #96 )
PLD( bge 4b )
5: ands ip, r2, #28
rsb ip, ip, #32
addne pc, pc, ip @ C is always clear here
b 7f
6: nop
ldr r3, [r1, #-4]!
ldr r4, [r1, #-4]!
ldr r5, [r1, #-4]!
ldr r6, [r1, #-4]!
ldr r7, [r1, #-4]!
ldr r8, [r1, #-4]!
ldr lr, [r1, #-4]!
add pc, pc, ip
nop
nop
str r3, [r0, #-4]!
str r4, [r0, #-4]!
str r5, [r0, #-4]!
str r6, [r0, #-4]!
str r7, [r0, #-4]!
str r8, [r0, #-4]!
str lr, [r0, #-4]!
CALGN( bcs 2b )
7: ldmfd sp!, {r5 - r8}
cfi_adjust_cfa_offset (-16)
cfi_restore (r5)
cfi_restore (r6)
cfi_restore (r7)
cfi_restore (r8)
8: movs r2, r2, lsl #31
ldrneb r3, [r1, #-1]!
ldrcsb r4, [r1, #-1]!
ldrcsb ip, [r1, #-1]
strneb r3, [r0, #-1]!
strcsb r4, [r0, #-1]!
strcsb ip, [r0, #-1]
#if defined (__ARM_ARCH_4T__) && defined (__THUMB_INTERWORK__)
ldmfd sp!, {r0, r4, lr}
cfi_adjust_cfa_offset (-12)
cfi_restore (r4)
cfi_restore (lr)
bx lr
#else
ldmfd sp!, {r0, r4, pc}
#endif
cfi_restore_state
9: cmp ip, #2
ldrgtb r3, [r1, #-1]!
ldrgeb r4, [r1, #-1]!
ldrb lr, [r1, #-1]!
strgtb r3, [r0, #-1]!
strgeb r4, [r0, #-1]!
subs r2, r2, ip
strb lr, [r0, #-1]!
blt 8b
ands ip, r1, #3
beq 1b
10: bic r1, r1, #3
cmp ip, #2
ldr r3, [r1, #0]
beq 17f
blt 18f
.macro backward_copy_shift push pull
subs r2, r2, #28
blt 14f
CALGN( ands ip, r1, #31 )
CALGN( rsb ip, ip, #32 )
CALGN( sbcnes r4, ip, r2 ) @ C is always set here
CALGN( subcc r2, r2, ip )
CALGN( bcc 15f )
11: stmfd sp!, {r5 - r9}
cfi_adjust_cfa_offset (20)
cfi_rel_offset (r5, 0)
cfi_rel_offset (r6, 4)
cfi_rel_offset (r7, 8)
cfi_rel_offset (r8, 12)
cfi_rel_offset (r9, 16)
PLD( pld [r1, #-4] )
PLD( subs r2, r2, #96 )
PLD( pld [r1, #-32] )
PLD( blt 13f )
PLD( pld [r1, #-64] )
PLD( pld [r1, #-96] )
12: PLD( pld [r1, #-128] )
13: ldmdb r1!, {r7, r8, r9, ip}
mov lr, r3, push #\push
subs r2, r2, #32
ldmdb r1!, {r3, r4, r5, r6}
orr lr, lr, ip, pull #\pull
mov ip, ip, push #\push
orr ip, ip, r9, pull #\pull
mov r9, r9, push #\push
orr r9, r9, r8, pull #\pull
mov r8, r8, push #\push
orr r8, r8, r7, pull #\pull
mov r7, r7, push #\push
orr r7, r7, r6, pull #\pull
mov r6, r6, push #\push
orr r6, r6, r5, pull #\pull
mov r5, r5, push #\push
orr r5, r5, r4, pull #\pull
mov r4, r4, push #\push
orr r4, r4, r3, pull #\pull
stmdb r0!, {r4 - r9, ip, lr}
bge 12b
PLD( cmn r2, #96 )
PLD( bge 13b )
ldmfd sp!, {r5 - r9}
cfi_adjust_cfa_offset (-20)
cfi_restore (r5)
cfi_restore (r6)
cfi_restore (r7)
cfi_restore (r8)
cfi_restore (r9)
14: ands ip, r2, #28
beq 16f
15: mov lr, r3, push #\push
ldr r3, [r1, #-4]!
subs ip, ip, #4
orr lr, lr, r3, pull #\pull
str lr, [r0, #-4]!
bgt 15b
CALGN( cmp r2, #0 )
CALGN( bge 11b )
16: add r1, r1, #(\pull / 8)
b 8b
.endm
backward_copy_shift push=8 pull=24
17: backward_copy_shift push=16 pull=16
18: backward_copy_shift push=24 pull=8
END(memmove)
libc_hidden_builtin_def (memmove)
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