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/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2006 Free Software Foundation, Inc.
* This file was originally part of the GNU C Library
* Contributed to glibc by MontaVista Software, Inc. (written by Nicolas Pitre)
* Adapted for Rockbox by Daniel Ankers
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#include "config.h"
/*
* Endian independent macros for shifting bytes within registers.
*/
#ifndef __ARMEB__
#define pull lsr
#define push lsl
#else
#define pull lsl
#define push lsr
#endif
/* Prototype: void *memcpy(void *dest, const void *src, size_t n); */
.section .icode,"ax",%progbits
.align 2
.global memcpy
.type memcpy,%function
memcpy:
stmfd sp!, {r0, r4, lr}
subs r2, r2, #4
blt 8f
ands ip, r0, #3
bne 9f
ands ip, r1, #3
bne 10f
1: subs r2, r2, #(28)
stmfd sp!, {r5 - r8}
blt 5f
2:
3:
4: ldmia r1!, {r3, r4, r5, r6, r7, r8, ip, lr}
subs r2, r2, #32
stmia r0!, {r3, r4, r5, r6, r7, r8, ip, lr}
bge 3b
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
7: ldmfd sp!, {r5 - r8}
8: movs r2, r2, lsl #31
ldrneb r3, [r1], #1
ldrcsb r4, [r1], #1
ldrcsb ip, [r1]
strneb r3, [r0], #1
strcsb r4, [r0], #1
strcsb ip, [r0]
ldmfd sp!, {r0, r4, pc}
9: rsb ip, ip, #4
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 lr, [r1], #4
beq 17f
bgt 18f
.macro forward_copy_shift pull push
subs r2, r2, #28
blt 14f
11: stmfd sp!, {r5 - r9}
12:
13: ldmia r1!, {r4, r5, r6, r7}
mov r3, lr, pull #\pull
subs r2, r2, #32
ldmia r1!, {r8, r9, ip, lr}
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
stmia r0!, {r3, r4, r5, r6, r7, r8, r9, ip}
bge 12b
ldmfd sp!, {r5 - r9}
14: ands ip, r2, #28
beq 16f
15: mov r3, lr, pull #\pull
ldr lr, [r1], #4
subs ip, ip, #4
orr r3, r3, lr, push #\push
str r3, [r0], #4
bgt 15b
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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