[apple/xnu.git] / osfmk / x86_64 / 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) */
/*			rdi,	 	     rsi,	      rdx   */
/*
 * Note: memcpy does not support overlapping copies
 */
ENTRY(memcpy)
	movq	%rdx,%rcx
	shrq	$3,%rcx				/* copy by 64-bit words */
	cld					/* copy forwards */
	rep
	movsq
	movq	%rdx,%rcx
	andq	$7,%rcx				/* any bytes left? */
	rep
	movsb
	ret

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

ENTRY(bcopy_no_overwrite)
	xchgq	%rsi,%rdi
	jmp	EXT(memcpy)

/*
 * bcopy(src, dst, cnt)
 *       rdi, rsi, rdx
 *  ws@tools.de     (Wolfgang Solfrank, TooLs GmbH) +49-228-985800
 */
ENTRY(bcopy)
	xchgq	%rsi,%rdi
	movq	%rdx,%rcx

	movq	%rdi,%rax
	subq	%rsi,%rax
	cmpq	%rcx,%rax			/* overlapping && src < dst? */
	jb	1f

	shrq	$3,%rcx				/* copy by 64-bit words */
	cld					/* nope, copy forwards */
	rep
	movsq
	movq	%rdx,%rcx
	andq	$7,%rcx				/* any bytes left? */
	rep
	movsb
	ret

	/* ALIGN_TEXT */
1:
	addq	%rcx,%rdi			/* copy backwards */
	addq	%rcx,%rsi
	decq	%rdi
	decq	%rsi
	andq	$7,%rcx				/* any fractional bytes? */
	std
	rep
	movsb
	movq	%rdx,%rcx			/* copy remainder by 32-bit words */
	shrq	$3,%rcx
	subq	$7,%rsi
	subq	$7,%rdi
	rep
	movsq
	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	*/
b0d623f7	31	/*
1c79356b A	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
b0d623f7 A	59	#include <i386/asm.h>
	60
	61	/* void memcpy((void ) to, (const void ) from, (size_t) bcount) /
	62	/* rdi, rsi, rdx */
	63	/*
	64	* Note: memcpy does not support overlapping copies
	65	*/
	66	ENTRY(memcpy)
	67	movq %rdx,%rcx
	68	shrq $3,%rcx /* copy by 64-bit words */
	69	cld /* copy forwards */
	70	rep
	71	movsq
	72	movq %rdx,%rcx
	73	andq $7,%rcx /* any bytes left? */
	74	rep
	75	movsb
	76	ret
	77
	78	/* void bcopy((const char ) from, (char ) to, (unsigned int) count) */
	79	/* rdi, rsi, rdx */
	80
	81	ENTRY(bcopy_no_overwrite)
	82	xchgq %rsi,%rdi
	83	jmp EXT(memcpy)
	84
1c79356b	85	/*
b0d623f7 A	86	* bcopy(src, dst, cnt)
	87	* rdi, rsi, rdx
	88	* ws@tools.de (Wolfgang Solfrank, TooLs GmbH) +49-228-985800
1c79356b	89	*/
b0d623f7 A	90	ENTRY(bcopy)
	91	xchgq %rsi,%rdi
	92	movq %rdx,%rcx
	93
	94	movq %rdi,%rax
	95	subq %rsi,%rax
	96	cmpq %rcx,%rax /* overlapping && src < dst? */
	97	jb 1f
1c79356b	98
b0d623f7 A	99	shrq $3,%rcx /* copy by 64-bit words */
	100	cld /* nope, copy forwards */
	101	rep
	102	movsq
	103	movq %rdx,%rcx
	104	andq $7,%rcx /* any bytes left? */
	105	rep
	106	movsb
	107	ret
1c79356b	108
b0d623f7 A	109	/* ALIGN_TEXT */
	110	1:
	111	addq %rcx,%rdi /* copy backwards */
	112	addq %rcx,%rsi
	113	decq %rdi
	114	decq %rsi
	115	andq $7,%rcx /* any fractional bytes? */
	116	std
	117	rep
	118	movsb
	119	movq %rdx,%rcx /* copy remainder by 32-bit words */
	120	shrq $3,%rcx
	121	subq $7,%rsi
	122	subq $7,%rdi
	123	rep
	124	movsq
	125	cld
	126	ret