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/*
* linux/arch/arm/lib/memcpy.S
*
* Author: Nicolas Pitre
* Created: Sep 28, 2005
* Copyright: MontaVista Software, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <asm/assembler.h>
#define W(instr) instr
#define LDR1W_SHIFT 0
#define STR1W_SHIFT 0
.macro ldr1w ptr reg abort
W(ldr) \reg, [\ptr], #4
.endm
.macro ldr4w ptr reg1 reg2 reg3 reg4 abort
ldmia \ptr!, {\reg1, \reg2, \reg3, \reg4}
.endm
.macro ldr8w ptr reg1 reg2 reg3 reg4 reg5 reg6 reg7 reg8 abort
ldmia \ptr!, {\reg1, \reg2, \reg3, \reg4, \reg5, \reg6, \reg7, \reg8}
.endm
.macro ldr1b ptr reg cond=al abort
ldr\cond\()b \reg, [\ptr], #1
.endm
.macro str1w ptr reg abort
W(str) \reg, [\ptr], #4
.endm
.macro str8w ptr reg1 reg2 reg3 reg4 reg5 reg6 reg7 reg8 abort
stmia \ptr!, {\reg1, \reg2, \reg3, \reg4, \reg5, \reg6, \reg7, \reg8}
.endm
.macro str1b ptr reg cond=al abort
str\cond\()b \reg, [\ptr], #1
.endm
.macro enter reg1 reg2
stmdb sp!, {r0, \reg1, \reg2}
.endm
.macro exit reg1 reg2
ldmfd sp!, {r0, \reg1, \reg2}
.endm
.text
/* Prototype: void *memcpy(void *dest, const void *src, size_t n); */
.globl memcpy
memcpy:
cmp r0, r1
moveq pc, lr
enter r4, lr
subs r2, r2, #4
blt 8f
ands ip, r0, #3
PLD( pld [r1, #0] )
bne 9f
ands ip, r1, #3
bne 10f
1: subs r2, r2, #(28)
stmfd sp!, {r5 - r8}
blt 5f
CALGN( ands ip, r0, #31 )
CALGN( rsb r3, ip, #32 )
CALGN( sbcnes r4, r3, r2 ) @ C is always set here
CALGN( bcs 2f )
CALGN( adr r4, 6f )
CALGN( subs r2, r2, r3 ) @ C gets set
CALGN( add pc, r4, ip )
PLD( pld [r1, #0] )
2: PLD( subs r2, r2, #96 )
PLD( pld [r1, #28] )
PLD( blt 4f )
PLD( pld [r1, #60] )
PLD( pld [r1, #92] )
3: PLD( pld [r1, #124] )
4: ldr8w r1, r3, r4, r5, r6, r7, r8, ip, lr, abort=20f
subs r2, r2, #32
str8w r0, r3, r4, r5, r6, r7, r8, ip, lr, abort=20f
bge 3b
PLD( cmn r2, #96 )
PLD( bge 4b )
5: ands ip, r2, #28
rsb ip, ip, #32
#if LDR1W_SHIFT > 0
lsl ip, ip, #LDR1W_SHIFT
#endif
addne pc, pc, ip @ C is always clear here
b 7f
6:
.rept (1 << LDR1W_SHIFT)
W(nop)
.endr
ldr1w r1, r3, abort=20f
ldr1w r1, r4, abort=20f
ldr1w r1, r5, abort=20f
ldr1w r1, r6, abort=20f
ldr1w r1, r7, abort=20f
ldr1w r1, r8, abort=20f
ldr1w r1, lr, abort=20f
#if LDR1W_SHIFT < STR1W_SHIFT
lsl ip, ip, #STR1W_SHIFT - LDR1W_SHIFT
#elif LDR1W_SHIFT > STR1W_SHIFT
lsr ip, ip, #LDR1W_SHIFT - STR1W_SHIFT
#endif
add pc, pc, ip
nop
.rept (1 << STR1W_SHIFT)
W(nop)
.endr
str1w r0, r3, abort=20f
str1w r0, r4, abort=20f
str1w r0, r5, abort=20f
str1w r0, r6, abort=20f
str1w r0, r7, abort=20f
str1w r0, r8, abort=20f
str1w r0, lr, abort=20f
CALGN( bcs 2b )
7: ldmfd sp!, {r5 - r8}
8: movs r2, r2, lsl #31
ldr1b r1, r3, ne, abort=21f
ldr1b r1, r4, cs, abort=21f
ldr1b r1, ip, cs, abort=21f
str1b r0, r3, ne, abort=21f
str1b r0, r4, cs, abort=21f
str1b r0, ip, cs, abort=21f
exit r4, pc
9: rsb ip, ip, #4
cmp ip, #2
ldr1b r1, r3, gt, abort=21f
ldr1b r1, r4, ge, abort=21f
ldr1b r1, lr, abort=21f
str1b r0, r3, gt, abort=21f
str1b r0, r4, ge, abort=21f
subs r2, r2, ip
str1b r0, lr, abort=21f
blt 8b
ands ip, r1, #3
beq 1b
10: bic r1, r1, #3
cmp ip, #2
ldr1w r1, lr, abort=21f
beq 17f
bgt 18f
.macro forward_copy_shift pull push
subs r2, r2, #28
blt 14f
CALGN( ands ip, r0, #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}
PLD( pld [r1, #0] )
PLD( subs r2, r2, #96 )
PLD( pld [r1, #28] )
PLD( blt 13f )
PLD( pld [r1, #60] )
PLD( pld [r1, #92] )
12: PLD( pld [r1, #124] )
13: ldr4w r1, r4, r5, r6, r7, abort=19f
mov r3, lr, pull #\pull
subs r2, r2, #32
ldr4w r1, r8, r9, ip, lr, abort=19f
orr r3, r3, r4, push #\push
mov r4, r4, pull #\pull
orr r4, r4, r5, push #\push
mov r5, r5, pull #\pull
orr r5, r5, r6, push #\push
mov r6, r6, pull #\pull
orr r6, r6, r7, push #\push
mov r7, r7, pull #\pull
orr r7, r7, r8, push #\push
mov r8, r8, pull #\pull
orr r8, r8, r9, push #\push
mov r9, r9, pull #\pull
orr r9, r9, ip, push #\push
mov ip, ip, pull #\pull
orr ip, ip, lr, push #\push
str8w r0, r3, r4, r5, r6, r7, r8, r9, ip, , abort=19f
bge 12b
PLD( cmn r2, #96 )
PLD( bge 13b )
ldmfd sp!, {r5 - r9}
14: ands ip, r2, #28
beq 16f
15: mov r3, lr, pull #\pull
ldr1w r1, lr, abort=21f
subs ip, ip, #4
orr r3, r3, lr, push #\push
str1w r0, r3, abort=21f
bgt 15b
CALGN( cmp r2, #0 )
CALGN( bge 11b )
16: sub r1, r1, #(\push / 8)
b 8b
.endm
forward_copy_shift pull=8 push=24
17: forward_copy_shift pull=16 push=16
18: forward_copy_shift pull=24 push=8
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