#
# Copyright (c) 2007 Michal Kebrt
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
#
# - Redistributions of source code must retain the above copyright
#   notice, this list of conditions and the following disclaimer.
# - Redistributions in binary form must reproduce the above copyright
#   notice, this list of conditions and the following disclaimer in the
#   documentation and/or other materials provided with the distribution.
# - The name of the author may not be used to endorse or promote products
#   derived from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
# OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
# IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
# NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#


.text

.global memcpy

memcpy:
	add     r3, r1, #3
	bic     r3, r3, #3
	cmp     r1, r3
	stmdb   sp!, {r4, lr}
	beq     4f
1:
	cmp     r2, #0
	movne   ip, #0
	beq     3f
2:
	ldrb    r3, [ip, r1]
	strb    r3, [ip, r0]
	add     ip, ip, #1
	cmp     ip, r2
	bne     2b
3:
	mov     r0, r1
	ldmia   sp!, {r4, pc}
4:
	add     r3, r0, #3
	bic     r3, r3, #3
	cmp     r0, r3
	bne     1b
	movs    r4, r2, lsr #2
	moveq   lr, r4
	beq     6f
	mov     lr, #0
	mov     ip, lr
5:
	ldr     r3, [ip, r1]
	add     lr, lr, #1
	cmp     lr, r4
	str     r3, [ip, r0]
	add     ip, ip, #4
	bne     5b
6:
	ands    r4, r2, #3
	beq     3b
	mov     r3, lr, lsl #2
	add     r0, r3, r0
	add     ip, r3, r1
	mov     r2, #0
7:
	ldrb    r3, [r2, ip]
	strb    r3, [r2, r0]
	add     r2, r2, #1
	cmp     r2, r4
	bne     7b
	b       3b