mirror of
git://sourceware.org/git/glibc.git
synced 2024-11-27 03:41:23 +08:00
94 lines
3.1 KiB
ArmAsm
94 lines
3.1 KiB
ArmAsm
|
/*-
|
||
|
|
* Copyright (c) 1990 The Regents of the University of California.
|
||
|
|
* All rights reserved.
|
||
|
|
*
|
||
|
|
* Redistribution and use in source and binary forms, with or without
|
||
|
|
* modification, are permitted provided that the following conditions
|
||
|
|
* are met:
|
||
|
|
* 1. Redistributions of source code must retain the above copyright
|
||
|
|
* notice, this list of conditions and the following disclaimer.
|
||
|
|
* 2. 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.
|
||
|
|
* 3. All advertising materials mentioning features or use of this software
|
||
|
|
* must display the following acknowledgement:
|
||
|
|
* This product includes software developed by the University of
|
||
|
|
* California, Berkeley and its contributors.
|
||
|
|
* 4. Neither the name of the University nor the names of its contributors
|
||
|
|
* may be used to endorse or promote products derived from this software
|
||
|
|
* without specific prior written permission.
|
||
|
|
*
|
||
|
|
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#if defined(LIBC_SCCS) && !defined(lint)
|
||
|
|
.asciz "@(#)memmove.s 5.1 (Berkeley) 5/15/90"
|
||
|
|
#endif /* LIBC_SCCS and not lint */
|
||
|
|
|
||
|
|
/*
|
||
|
|
* void *memmove(dst, src, size)
|
||
|
|
* returns dst
|
||
|
|
*
|
||
|
|
* This optimises the usual case (count < 65536) at the expense
|
||
|
|
* of some extra memory references and branches when count >= 65536.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include "DEFS.h"
|
||
|
|
|
||
|
|
ENTRY(memmove, 0)
|
||
|
|
movzwl $65535,r0 /* r0 = 64K (needed below) */
|
||
|
|
movq 8(ap),r1 /* r1 = src, r2 = length */
|
||
|
|
movl 4(ap),r3 /* r3 = dst */
|
||
|
|
cmpl r1,r3
|
||
|
|
bgtru 1f /* normal forward case */
|
||
|
|
beql 2f /* equal, nothing to do */
|
||
|
|
addl2 r2,r1 /* overlaps iff src<dst but src+len>dst */
|
||
|
|
cmpl r1,r3
|
||
|
|
bgtru 4f /* overlapping, must move backwards */
|
||
|
|
subl2 r2,r1
|
||
|
|
|
||
|
|
1: /* move forward */
|
||
|
|
cmpl r2,r0
|
||
|
|
bgtru 3f /* stupid movc3 limitation */
|
||
|
|
movc3 r2,(r1),(r3) /* move it all */
|
||
|
|
2:
|
||
|
|
movl 4(ap),r0 /* return original dst */
|
||
|
|
ret
|
||
|
|
3:
|
||
|
|
subl2 r0,12(ap) /* adjust length by 64K */
|
||
|
|
movc3 r0,(r1),(r3) /* move 64K */
|
||
|
|
movl 12(ap),r2
|
||
|
|
decw r0 /* from 0 to 65535 */
|
||
|
|
brb 1b /* retry */
|
||
|
|
|
||
|
|
4: /* move backward */
|
||
|
|
addl2 r2,r3
|
||
|
|
5:
|
||
|
|
cmpl r2,r0
|
||
|
|
bgtru 6f /* stupid movc3 limitation */
|
||
|
|
subl2 r2,r1
|
||
|
|
subl2 r2,r3
|
||
|
|
movc3 r2,(r1),(r3) /* move it all */
|
||
|
|
movl 4(ap),r0 /* return original dst */
|
||
|
|
ret
|
||
|
|
6:
|
||
|
|
subl2 r0,12(ap) /* adjust length by 64K */
|
||
|
|
subl2 r0,r1
|
||
|
|
subl2 r0,r3
|
||
|
|
movc3 r0,(r1),(r3) /* move 64K */
|
||
|
|
movl 12(ap),r2
|
||
|
|
decw r0
|
||
|
|
subl2 r0,r1
|
||
|
|
subl2 r0,r3
|
||
|
|
brb 5b
|