[apple/xnu.git] / osfmk / i386 / bcopy.s

/*
 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 * 
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */
/*
 * @OSF_COPYRIGHT@
 */
/*
 * Mach Operating System
 * Copyright (c) 1991,1990 Carnegie Mellon University
 * All Rights Reserved.
 * 
 * Permission to use, copy, modify and distribute this software and its
 * documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 * 
 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 * 
 * Carnegie Mellon requests users of this software to return to
 * 
 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 * 
 * any improvements or extensions that they make and grant Carnegie Mellon
 * the rights to redistribute these changes.
 */
/*
 */

#include <i386/asm.h>

/* void *memcpy((void *) to, (const void *) from, (size_t) bcount) */

ENTRY(memcpy)
	pushl	%edi
	pushl	%esi
	movl	8+ 4(%esp),%edi		/* to */
	movl	%edi,%eax		/* returns its first argument */
	movl	8+ 8(%esp),%esi		/* from */
memcpy_common:
	movl	8+ 12(%esp),%edx	/* number of bytes */
	cld
/* move longs*/
	movl	%edx,%ecx
	shrl	$2,%ecx
	rep
	movsl
/* move bytes*/
	movl	%edx,%ecx
	andl	$3,%ecx
	rep
	movsb
	popl	%esi
	popl	%edi
	ret

/* void bcopy((const char *) from, (char *) to, (unsigned int) count) */

ENTRY(bcopy_no_overwrite)
	pushl	%edi
	pushl	%esi
	movl	8+ 8(%esp),%edi		/* to */
	movl	8+ 4(%esp),%esi		/* from */
	jmp	memcpy_common

/* bcopy16(from, to, bcount) using word moves */

ENTRY(bcopy16)
	pushl	%edi
	pushl	%esi
 	movl	8+12(%esp),%edx		/*  8 for the two pushes above */
 	movl	8+ 8(%esp),%edi
 	movl	8+ 4(%esp),%esi
/* move words */
0:	cld
	movl	%edx,%ecx
	shrl	$1,%ecx
	rep
	movsw
/* move bytes */
	movl	%edx,%ecx
	andl	$1,%ecx
	rep
	movsb
	popl	%esi
	popl	%edi
	ret	

	
 /*
  * Based on NetBSD's bcopy.S from their libc.
  * bcopy(src, dst, cnt)
  *  ws@tools.de     (Wolfgang Solfrank, TooLs GmbH) +49-228-985800
  */
ENTRY(bcopy)
	        pushl   %esi
	        pushl   %edi
	        movl    12(%esp),%esi
	        movl    16(%esp),%edi
	        movl    20(%esp),%ecx

	        movl    %edi,%edx
	        subl    %esi,%edx
	        cmpl    %ecx,%edx                       /* overlapping && src < dst? */
			movl    %ecx,%edx
	        jb      1f

	        shrl    $2,%ecx                         /* copy by 32-bit words */
	        cld                                     /* nope, copy forwards */
	        rep
	        movsl
	        movl    %edx,%ecx
	        andl    $3,%ecx                         /* any bytes left? */
	        rep
	        movsb
	        popl    %edi
	        popl    %esi
	        ret


1:
	        addl    %ecx,%edi                       /* copy backwards */
	        addl    %ecx,%esi
	        decl    %edi
	        decl    %esi
	        andl    $3,%ecx                         /* any fractional bytes? */
	        std
	        rep
	        movsb
	        movl    %edx,%ecx                   /* copy remainder by 32-bit words */
	        shrl    $2,%ecx
	        subl    $3,%esi
	        subl    $3,%edi
	        rep
	        movsl
	        popl    %edi
	        popl    %esi
	        cld
	        ret
Commit	Line	Data
1c79356b A	1	/*
	2	* Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
	3	*
2d21ac55	4	* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
1c79356b	5	*
2d21ac55 A	6	* This file contains Original Code and/or Modifications of Original Code
	7	* as defined in and that are subject to the Apple Public Source License
	8	* Version 2.0 (the 'License'). You may not use this file except in
	9	* compliance with the License. The rights granted to you under the License
	10	* may not be used to create, or enable the creation or redistribution of,
	11	* unlawful or unlicensed copies of an Apple operating system, or to
	12	* circumvent, violate, or enable the circumvention or violation of, any
	13	* terms of an Apple operating system software license agreement.
8f6c56a5	14	*
2d21ac55 A	15	* Please obtain a copy of the License at
	16	* http://www.opensource.apple.com/apsl/ and read it before using this file.
	17	*
	18	* The Original Code and all software distributed under the License are
	19	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
8f6c56a5 A	20	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
8f6c56a5 A	21	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
2d21ac55 A	22	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	23	* Please see the License for the specific language governing rights and
	24	* limitations under the License.
8f6c56a5	25	*
2d21ac55	26	* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
1c79356b A	27	*/
	28	/*
	29	* @OSF_COPYRIGHT@
	30	*/
	31	/*
	32	* Mach Operating System
	33	* Copyright (c) 1991,1990 Carnegie Mellon University
	34	* All Rights Reserved.
	35	*
	36	* Permission to use, copy, modify and distribute this software and its
	37	* documentation is hereby granted, provided that both the copyright
	38	* notice and this permission notice appear in all copies of the
	39	* software, derivative works or modified versions, and any portions
	40	* thereof, and that both notices appear in supporting documentation.
	41	*
	42	* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
	43	* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
	44	* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
	45	*
	46	* Carnegie Mellon requests users of this software to return to
	47	*
	48	* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
	49	* School of Computer Science
	50	* Carnegie Mellon University
	51	* Pittsburgh PA 15213-3890
	52	*
	53	* any improvements or extensions that they make and grant Carnegie Mellon
	54	* the rights to redistribute these changes.
	55	*/
	56	/*
	57	*/
	58
	59	#include <i386/asm.h>
	60
	61	/* void memcpy((void ) to, (const void ) from, (size_t) bcount) /
	62
	63	ENTRY(memcpy)
	64	pushl %edi
	65	pushl %esi
	66	movl 8+ 4(%esp),%edi /* to */
	67	movl %edi,%eax /* returns its first argument */
	68	movl 8+ 8(%esp),%esi /* from */
	69	memcpy_common:
	70	movl 8+ 12(%esp),%edx /* number of bytes */
	71	cld
	72	/* move longs*/
	73	movl %edx,%ecx
2d21ac55	74	shrl $2,%ecx
1c79356b A	75	rep
	76	movsl
	77	/* move bytes*/
	78	movl %edx,%ecx
	79	andl $3,%ecx
	80	rep
	81	movsb
	82	popl %esi
	83	popl %edi
	84	ret
	85
	86	/* void bcopy((const char ) from, (char ) to, (unsigned int) count) */
	87
	88	ENTRY(bcopy_no_overwrite)
	89	pushl %edi
	90	pushl %esi
	91	movl 8+ 8(%esp),%edi /* to */
	92	movl 8+ 4(%esp),%esi /* from */
	93	jmp memcpy_common
	94
	95	/* bcopy16(from, to, bcount) using word moves */
	96
	97	ENTRY(bcopy16)
	98	pushl %edi
	99	pushl %esi
	100	movl 8+12(%esp),%edx /* 8 for the two pushes above */
	101	movl 8+ 8(%esp),%edi
	102	movl 8+ 4(%esp),%esi
	103	/* move words */
	104	0: cld
	105	movl %edx,%ecx
2d21ac55	106	shrl $1,%ecx
1c79356b A	107	rep
	108	movsw
	109	/* move bytes */
	110	movl %edx,%ecx
	111	andl $1,%ecx
	112	rep
	113	movsb
	114	popl %esi
	115	popl %edi
	116	ret
	117
91447636 A	118
	119	/*
	120	* Based on NetBSD's bcopy.S from their libc.
	121	* bcopy(src, dst, cnt)
	122	* ws@tools.de (Wolfgang Solfrank, TooLs GmbH) +49-228-985800
	123	*/
	124	ENTRY(bcopy)
	125	pushl %esi
	126	pushl %edi
	127	movl 12(%esp),%esi
	128	movl 16(%esp),%edi
	129	movl 20(%esp),%ecx
	130
	131	movl %edi,%edx
	132	subl %esi,%edx
	133	cmpl %ecx,%edx /* overlapping && src < dst? */
	134	movl %ecx,%edx
	135	jb 1f
	136
	137	shrl $2,%ecx /* copy by 32-bit words */
	138	cld /* nope, copy forwards */
	139	rep
	140	movsl
	141	movl %edx,%ecx
	142	andl $3,%ecx /* any bytes left? */
	143	rep
	144	movsb
	145	popl %edi
	146	popl %esi
	147	ret
	148
	149
	150	1:
	151	addl %ecx,%edi /* copy backwards */
	152	addl %ecx,%esi
	153	decl %edi
	154	decl %esi
	155	andl $3,%ecx /* any fractional bytes? */
	156	std
	157	rep
	158	movsb
	159	movl %edx,%ecx /* copy remainder by 32-bit words */
	160	shrl $2,%ecx
	161	subl $3,%esi
	162	subl $3,%edi
	163	rep
	164	movsl
	165	popl %edi
	166	popl %esi
	167	cld
	168	ret