/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2008 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
.file "__align_cpy_2.s"
/*
* __align_cpy_2(s1, s2, len)
*
* Copy s2 to s1, always copy n bytes.
* Note: this does not work for overlapped copies, bcopy() does
* This routine is copied from memcpy.s, with all values doubled.
* No attempt has been made to improve the comments or performance.
*
*/
#include <sys/asm_linkage.h>
ENTRY(__align_cpy_2)
cmp %o0, %o1
be,pn %xcc, .done ! Identical addresses--done.
mov %o0, %g5 ! save des address for return val
cmp %o2, 18 ! for small counts copy bytes
ble,pn %xcc, .dbytecp
andcc %o1, 6, %o5 ! is src 8-byte aligned
bz,pn %xcc, .aldst
cmp %o5, 4 ! is src 4-byte aligned
be,pt %xcc, .s2algn
cmp %o5, 6 ! src is 2-byte aligned
.s1algn:lduh [%o1], %o3 ! move 2 or 6 bytes to align it
inc 2, %o1
sth %o3, [%g5] ! move 2 bytes to align src
inc 2, %g5
bne,pt %xcc, .s2algn
dec 2, %o2
b .ald ! now go align dest
andcc %g5, 6, %o5
.s2algn:lduw [%o1], %o3 ! know src is 4-byte aligned
inc 4, %o1
srlx %o3, 16, %o4
sth %o4, [%g5] ! have to do 2-bytes,
sth %o3, [%g5 + 2] ! don't know dst alignment
inc 4, %g5
dec 4, %o2
.aldst: andcc %g5, 6, %o5 ! align the destination address
.ald: bz,pn %xcc, .w4cp
cmp %o5, 4
bz,pn %xcc, .w2cp
cmp %o5, 6
.w3cp: ldx [%o1], %o4
inc 8, %o1
srlx %o4, 48, %o5
sth %o5, [%g5]
bne,pt %xcc, .w1cp
inc 2, %g5
dec 2, %o2
andn %o2, 6, %o3 ! o3 is aligned word count
sub %o1, %g5, %o1 ! g5 gets the difference
1: sllx %o4, 16, %g1 ! save residual bytes
ldx [%o1+%g5], %o4
deccc 8, %o3
srlx %o4, 48, %o5 ! merge with residual
or %o5, %g1, %g1
stx %g1, [%g5]
bnz,pt %xcc, 1b
inc 8, %g5
sub %o1, 6, %o1 ! used two bytes of last word read
b 7f
and %o2, 6, %o2
.w1cp: srlx %o4, 16, %o5
st %o5, [%g5]
inc 4, %g5
dec 6, %o2
andn %o2, 6, %o3
sub %o1, %g5, %o1 ! g5 gets the difference
2: sllx %o4, 48, %g1 ! save residual bytes
ldx [%o1+%g5], %o4
deccc 8, %o3
srlx %o4, 16, %o5 ! merge with residual
or %o5, %g1, %g1
stx %g1, [%g5]
bnz,pt %xcc, 2b
inc 8, %g5
sub %o1, 2, %o1 ! used six bytes of last word read
b 7f
and %o2, 6, %o2
.w2cp: ldx [%o1], %o4
inc 8, %o1
srlx %o4, 32, %o5
st %o5, [%g5]
inc 4, %g5
dec 4, %o2
andn %o2, 6, %o3 ! o3 is aligned word count
sub %o1, %g5, %o1 ! g5 gets the difference
3: sllx %o4, 32, %g1 ! save residual bytes
ldx [%o1+%g5], %o4
deccc 8, %o3
srlx %o4, 32, %o5 ! merge with residual
or %o5, %g1, %g1
stx %g1, [%g5]
bnz,pt %xcc, 3b
inc 8, %g5
sub %o1, 4, %o1 ! used four bytes of last word read
b 7f
and %o2, 6, %o2
.w4cp: andn %o2, 6, %o3 ! o3 is aligned word count
sub %o1, %g5, %o1 ! g5 gets the difference
1: ldx [%o1+%g5], %o4 ! read from address
deccc 8, %o3 ! decrement count
stx %o4, [%g5] ! write at destination address
bg,pt %xcc, 1b
inc 8, %g5 ! increment to address
b 7f
and %o2, 6, %o2 ! number of leftover bytes, if any
!
! differenced byte copy, works with any alignment
!
.dbytecp:
b 7f
sub %o1, %g5, %o1 ! g5 gets the difference
4: sth %o4, [%g5] ! write to address
inc 2, %g5 ! inc to address
7: deccc 2, %o2 ! decrement count
bge,a,pt %xcc,4b ! loop till done
lduh [%o1+%g5], %o4 ! read from address
.done:
retl
nop
SET_SIZE(__align_cpy_2)