xref: /onnv-gate/usr/src/lib/libc/i386/gen/memcpy.s (revision 10931:930e138fb604)
10Sstevel@tonic-gate/*
20Sstevel@tonic-gate * CDDL HEADER START
30Sstevel@tonic-gate *
40Sstevel@tonic-gate * The contents of this file are subject to the terms of the
56515Sraf * Common Development and Distribution License (the "License").
66515Sraf * You may not use this file except in compliance with the License.
70Sstevel@tonic-gate *
80Sstevel@tonic-gate * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
90Sstevel@tonic-gate * or http://www.opensolaris.org/os/licensing.
100Sstevel@tonic-gate * See the License for the specific language governing permissions
110Sstevel@tonic-gate * and limitations under the License.
120Sstevel@tonic-gate *
130Sstevel@tonic-gate * When distributing Covered Code, include this CDDL HEADER in each
140Sstevel@tonic-gate * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
150Sstevel@tonic-gate * If applicable, add the following below this CDDL HEADER, with the
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180Sstevel@tonic-gate *
190Sstevel@tonic-gate * CDDL HEADER END
200Sstevel@tonic-gate */
216515Sraf
220Sstevel@tonic-gate/*
23*10931SSudheer.Abdul-Salam@Sun.COM * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
240Sstevel@tonic-gate * Use is subject to license terms.
250Sstevel@tonic-gate */
260Sstevel@tonic-gate
277298SMark.J.Nelson@Sun.COM	.file	"memcpy.s"
280Sstevel@tonic-gate
290Sstevel@tonic-gate#include <sys/asm_linkage.h>
300Sstevel@tonic-gate
310Sstevel@tonic-gate	ANSI_PRAGMA_WEAK(memmove,function)
320Sstevel@tonic-gate	ANSI_PRAGMA_WEAK(memcpy,function)
330Sstevel@tonic-gate
340Sstevel@tonic-gate#include "SYS.h"
350Sstevel@tonic-gate
360Sstevel@tonic-gate	ENTRY(memcpy)
370Sstevel@tonic-gate	movl	%edi,%edx	/ save register variables
380Sstevel@tonic-gate	pushl	%esi
390Sstevel@tonic-gate	movl	8(%esp),%edi	/ %edi = dest address
400Sstevel@tonic-gate	movl	12(%esp),%esi	/ %esi = source address
410Sstevel@tonic-gate	movl	16(%esp),%ecx	/ %ecx = length of string
420Sstevel@tonic-gate	movl	%edi,%eax	/ return value from the call
430Sstevel@tonic-gate
440Sstevel@tonic-gate	shrl	$2,%ecx		/ %ecx = number of words to move
450Sstevel@tonic-gate	rep ; smovl		/ move the words
460Sstevel@tonic-gate
470Sstevel@tonic-gate	movl	16(%esp),%ecx	/ %ecx = number of bytes to move
480Sstevel@tonic-gate	andl	$0x3,%ecx	/ %ecx = number of bytes left to move
490Sstevel@tonic-gate	rep ; smovb		/ move the bytes
500Sstevel@tonic-gate
510Sstevel@tonic-gate	popl	%esi		/ restore register variables
520Sstevel@tonic-gate	movl	%edx,%edi
530Sstevel@tonic-gate	ret
540Sstevel@tonic-gate	SET_SIZE(memcpy)
550Sstevel@tonic-gate
560Sstevel@tonic-gate
570Sstevel@tonic-gate	ENTRY(memmove)
580Sstevel@tonic-gate	pushl	%edi		/ save off %edi, %esi and move destination
590Sstevel@tonic-gate	movl	4+12(%esp),%ecx	/ get number of bytes to move
600Sstevel@tonic-gate	pushl	%esi
610Sstevel@tonic-gate	testl	%ecx,%ecx	/ if (n == 0)
620Sstevel@tonic-gate	je	.CleanupReturn	/    return(s);
630Sstevel@tonic-gate	movl	8+ 4(%esp),%edi	/ destination buffer address
640Sstevel@tonic-gate	movl	8+ 8(%esp),%esi	/ source buffer address
650Sstevel@tonic-gate.Common:
660Sstevel@tonic-gate	movl	$3,%eax		/ heavily used constant
670Sstevel@tonic-gate	cmpl	%esi,%edi	/ if (source addr > dest addr)
680Sstevel@tonic-gate	leal	-1(%esi,%ecx),%edx
69*10931SSudheer.Abdul-Salam@Sun.COM	jbe	.CopyRight	/
700Sstevel@tonic-gate	cmpl	%edx,%edi
71*10931SSudheer.Abdul-Salam@Sun.COM	jbe	.CopyLeft
720Sstevel@tonic-gate.CopyRight:
730Sstevel@tonic-gate	cmpl	$8,%ecx		/    if (size < 8 bytes)
740Sstevel@tonic-gate	jbe	.OneByteCopy	/        goto fast short copy loop
750Sstevel@tonic-gate.FourByteCopy:
760Sstevel@tonic-gate	movl	%ecx,%edx	/    save count
770Sstevel@tonic-gate	movl	%esi,%ecx	/    get source buffer 4 byte aligned
780Sstevel@tonic-gate	andl	%eax,%ecx
790Sstevel@tonic-gate	jz	.SkipAlignRight
800Sstevel@tonic-gate	subl	%ecx,%edx
810Sstevel@tonic-gate	rep;	smovb		/    do the byte part of copy
820Sstevel@tonic-gate.SkipAlignRight:
830Sstevel@tonic-gate	movl	%edx,%ecx
840Sstevel@tonic-gate	shrl	$2,%ecx
850Sstevel@tonic-gate	rep;	smovl		/    do the long word part
860Sstevel@tonic-gate	movl	%edx,%ecx	/    compute bytes left to move
870Sstevel@tonic-gate	andl	%eax,%ecx	/    complete copy of remaining bytes
880Sstevel@tonic-gate	jz	.CleanupReturn
890Sstevel@tonic-gate.OneByteCopy:
900Sstevel@tonic-gate	rep;	smovb		/    do the byte part of copy
910Sstevel@tonic-gate.CleanupReturn:
920Sstevel@tonic-gate	popl	%esi		/  }
930Sstevel@tonic-gate	popl	%edi		/  restore registers
940Sstevel@tonic-gate	movl	4(%esp),%eax	/  set up return value
950Sstevel@tonic-gate.Return:
960Sstevel@tonic-gate	ret			/  return(dba);
970Sstevel@tonic-gate
980Sstevel@tonic-gate.CopyLeft:
990Sstevel@tonic-gate	std				/ reverse direction bit (RtoL)
1000Sstevel@tonic-gate	cmpl	$12,%ecx		/ if (size < 12)
1010Sstevel@tonic-gate	ja	.BigCopyLeft		/ {
1020Sstevel@tonic-gate	movl	%edx,%esi		/     src = src + size - 1
1030Sstevel@tonic-gate	leal	-1(%ecx,%edi),%edi	/     dst = dst + size - 1
1040Sstevel@tonic-gate	rep;	smovb			/    do the byte copy
1050Sstevel@tonic-gate	cld				/    reset direction flag to LtoR
1060Sstevel@tonic-gate	popl	%esi			/  }
1070Sstevel@tonic-gate	popl	%edi			/  restore registers
1080Sstevel@tonic-gate	movl	4(%esp),%eax		/  set up return value
1090Sstevel@tonic-gate	ret				/  return(dba);
1100Sstevel@tonic-gate.BigCopyLeft:				/ } else {
1110Sstevel@tonic-gate	xchgl	%edx,%ecx
1120Sstevel@tonic-gate	movl	%ecx,%esi		/ align source w/byte copy
1130Sstevel@tonic-gate	leal	-1(%edx,%edi),%edi
1140Sstevel@tonic-gate	andl	%eax,%ecx
1150Sstevel@tonic-gate	jz	.SkipAlignLeft
1160Sstevel@tonic-gate	addl	$1, %ecx		/ we need to insure that future
1170Sstevel@tonic-gate	subl	%ecx,%edx		/ copy is done on aligned boundary
1180Sstevel@tonic-gate	rep;	smovb
1190Sstevel@tonic-gate.SkipAlignLeft:
1200Sstevel@tonic-gate	movl	%edx,%ecx
1210Sstevel@tonic-gate	subl	%eax,%esi
1220Sstevel@tonic-gate	shrl	$2,%ecx			/ do 4 byte copy RtoL
1230Sstevel@tonic-gate	subl	%eax,%edi
1240Sstevel@tonic-gate	rep;	smovl
1250Sstevel@tonic-gate	andl	%eax,%edx		/ do 1 byte copy whats left
1260Sstevel@tonic-gate	jz	.CleanupReturnLeft
1270Sstevel@tonic-gate	movl	%edx,%ecx
1280Sstevel@tonic-gate	addl	%eax,%esi		/ rep; smovl instruction will decrement
1290Sstevel@tonic-gate	addl	%eax,%edi		/ %edi, %esi by four after each copy
1300Sstevel@tonic-gate					/ adding 3 will restore pointers to byte
1310Sstevel@tonic-gate					/ before last double word copied
1320Sstevel@tonic-gate					/ which is where they are expected to
1330Sstevel@tonic-gate					/ be for the single byte copy code
1340Sstevel@tonic-gate	rep;	smovb
1350Sstevel@tonic-gate.CleanupReturnLeft:
1360Sstevel@tonic-gate	cld				/ reset direction flag to LtoR
1370Sstevel@tonic-gate	popl	%esi
1380Sstevel@tonic-gate	popl	%edi			/ restore registers
1390Sstevel@tonic-gate	movl	4(%esp),%eax		/ set up return value
1400Sstevel@tonic-gate	ret				/ return(dba);
1410Sstevel@tonic-gate	SET_SIZE(memmove)
142