Subversion Repositories HelenOS

#

# 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

# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF

# 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