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File: [cvs.NetBSD.org] / src / lib / libc / arch / m68k / string / memccpy.S (download)

Revision 1.1, Mon Feb 5 00:17:22 2001 UTC (21 years, 6 months ago) by scottr
Branch: MAIN
CVS Tags: yamt-pf42-baseX, yamt-pf42-base4, yamt-pf42-base3, yamt-pf42-base2, yamt-pf42-base, yamt-pf42, yamt-pagecache-tag8, yamt-pagecache-base8, yamt-pagecache-base7, yamt-pagecache-base6, yamt-pagecache-base5, yamt-pagecache-base4, yamt-pagecache-base3, yamt-pagecache-base2, yamt-pagecache-base, wrstuden-revivesa-base-3, wrstuden-revivesa-base-2, wrstuden-revivesa-base-1, wrstuden-revivesa-base, wrstuden-revivesa, wrstuden-fixsa-newbase, wrstuden-fixsa-base-1, wrstuden-fixsa-base, wrstuden-fixsa, netbsd-6-base, netbsd-6-1-RELEASE, netbsd-6-1-RC4, netbsd-6-1-RC3, netbsd-6-1-RC2, netbsd-6-1-RC1, netbsd-6-1-5-RELEASE, netbsd-6-1-4-RELEASE, netbsd-6-1-3-RELEASE, netbsd-6-1-2-RELEASE, netbsd-6-1-1-RELEASE, netbsd-6-1, netbsd-6-0-RELEASE, netbsd-6-0-RC2, netbsd-6-0-RC1, netbsd-6-0-6-RELEASE, netbsd-6-0-5-RELEASE, netbsd-6-0-4-RELEASE, netbsd-6-0-3-RELEASE, netbsd-6-0-2-RELEASE, netbsd-6-0-1-RELEASE, netbsd-6-0, netbsd-6, netbsd-5-base, netbsd-5-2-RELEASE, netbsd-5-2-RC1, netbsd-5-2-3-RELEASE, netbsd-5-2-2-RELEASE, netbsd-5-2-1-RELEASE, netbsd-5-2, netbsd-5-1-RELEASE, netbsd-5-1-RC4, netbsd-5-1-RC3, netbsd-5-1-RC2, netbsd-5-1-RC1, netbsd-5-1-5-RELEASE, netbsd-5-1-4-RELEASE, netbsd-5-1-3-RELEASE, netbsd-5-1-2-RELEASE, netbsd-5-1-1-RELEASE, netbsd-5-1, netbsd-5-0-RELEASE, netbsd-5-0-RC4, netbsd-5-0-RC3, netbsd-5-0-RC2, netbsd-5-0-RC1, netbsd-5-0-2-RELEASE, netbsd-5-0-1-RELEASE, netbsd-5-0, netbsd-5, netbsd-4-base, netbsd-4-0-RELEASE, netbsd-4-0-RC5, netbsd-4-0-RC4, netbsd-4-0-RC3, netbsd-4-0-RC2, netbsd-4-0-RC1, netbsd-4-0-1-RELEASE, netbsd-4-0, netbsd-4, netbsd-3-base, netbsd-3-1-RELEASE, netbsd-3-1-RC4, netbsd-3-1-RC3, netbsd-3-1-RC2, netbsd-3-1-RC1, netbsd-3-1-1-RELEASE, netbsd-3-1, netbsd-3-0-RELEASE, netbsd-3-0-RC6, netbsd-3-0-RC5, netbsd-3-0-RC4, netbsd-3-0-RC3, netbsd-3-0-RC2, netbsd-3-0-RC1, netbsd-3-0-3-RELEASE, netbsd-3-0-2-RELEASE, netbsd-3-0-1-RELEASE, netbsd-3-0, netbsd-3, netbsd-2-base, netbsd-2-1-RELEASE, netbsd-2-1-RC6, netbsd-2-1-RC5, netbsd-2-1-RC4, netbsd-2-1-RC3, netbsd-2-1-RC2, netbsd-2-1-RC1, netbsd-2-1, netbsd-2-0-base, netbsd-2-0-RELEASE, netbsd-2-0-RC5, netbsd-2-0-RC4, netbsd-2-0-RC3, netbsd-2-0-RC2, netbsd-2-0-RC1, netbsd-2-0-3-RELEASE, netbsd-2-0-2-RELEASE, netbsd-2-0-1-RELEASE, netbsd-2-0, netbsd-2, netbsd-1-6-base, netbsd-1-6-RELEASE, netbsd-1-6-RC3, netbsd-1-6-RC2, netbsd-1-6-RC1, netbsd-1-6-PATCH002-RELEASE, netbsd-1-6-PATCH002-RC4, netbsd-1-6-PATCH002-RC3, netbsd-1-6-PATCH002-RC2, netbsd-1-6-PATCH002-RC1, netbsd-1-6-PATCH002, netbsd-1-6-PATCH001-RELEASE, netbsd-1-6-PATCH001-RC3, netbsd-1-6-PATCH001-RC2, netbsd-1-6-PATCH001-RC1, netbsd-1-6-PATCH001, netbsd-1-6, nathanw_sa_end, nathanw_sa_before_merge, nathanw_sa_base, nathanw_sa, mjf-devfs2-base, mjf-devfs2, matt-premerge-20091211, matt-nb6-plus-nbase, matt-nb6-plus-base, matt-nb6-plus, matt-nb5-pq3-base, matt-nb5-pq3, matt-nb5-mips64-u2-k2-k4-k7-k8-k9, matt-nb5-mips64-u1-k1-k5, matt-nb5-mips64-premerge-20101231, matt-nb5-mips64-premerge-20091211, matt-nb5-mips64-k15, matt-nb5-mips64, matt-nb4-mips64-k7-u2a-k9b, matt-mips64-premerge-20101231, matt-mips64-base2, matt-mips64-base, matt-mips64, matt-armv6-prevmlocking, matt-armv6-nbase, matt-armv6-base, matt-armv6, keiichi-mipv6-base, keiichi-mipv6, jym-xensuspend-nbase, jym-xensuspend-base, jym-xensuspend, hpcarm-cleanup-nbase, hpcarm-cleanup-base, hpcarm-cleanup, fvdl_fs64_base, cube-autoconf-base, cube-autoconf, christos-time_t-nbase, christos-time_t-base, christos-time_t, cherry-xenmp-base, cherry-xenmp, bouyer-quota2-nbase, bouyer-quota2-base, bouyer-quota2, agc-symver-base, agc-symver, abandoned-netbsd-4-base, abandoned-netbsd-4
Branch point for: yamt-pagecache, tls-maxphys, netbsd-1-5

Implement a significantly improved version of memccpy(), with thanks to
Ignatios Souvatzis for correcting the SVR4 ABI code and for a few
micro-optimizations that followed from these changes.

The overall improvement was measured at 3-4x for copies of at least
4 bytes on the 68030, and 8 bytes on the 68040.  For smaller copies
the improvement was still measurable, if not as dramatic.

/*	$NetBSD: memccpy.S,v 1.1 2001/02/05 00:17:22 scottr Exp $	*/

/*
 * Copyright (C) 1999 Scott Reynolds.  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. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
 */

#include <machine/asm.h>

#if defined(LIBC_SCCS) && !defined(lint)
	RCSID("$NetBSD: memccpy.S,v 1.1 2001/02/05 00:17:22 scottr Exp $")
#endif /* LIBC_SCCS and not lint */

ENTRY(memccpy)
	movl	%sp@(16),%d0		| count
	jeq	Lmcbail			| nothing to do

	movl	%sp@(4),%a0		| a0 = toaddr
	subql	#1,%d0			|   prepare count for DBcc loop
	movl	%sp@(8),%a1		| a1 = fromaddr
	movl	%sp@(12),%d1		| d1 = terminator
	jeq	Lmcloop			|   handle ASCII NUL specially

	movl	%d2,%sp@-		| save scratch register
Lmcnzloop:
	movb	%a1@+,%d2		| move a byte
	movb	%d2,%a0@+
	cmpb	%d2,%d1			| found the terminator?
	dbeq	%d0,Lmcnzloop		| if not, keep transferring,
	jeq	Lmcnzdone		|   otherwise done
	clrw	%d0			| check to see if more to do
	subql	#1,%d0
	jcc	Lmcnzloop		| yes, keep going...

	movl	%sp@+,%d2		| restore scratch register
	movql	#0,%d0			| no terminator found, return NULL
#ifdef __SVR4_ABI__
	movl	%d0,%a0			| XXX maybe use lea to avoid stall?
#endif
	rts

Lmcloop:
	movb	%a1@+,%a0@+		| move a byte; was it NUL?
	dbeq	%d0,Lmcloop		| if not, keep transferring,
	jeq	Lmcdone			|   otherwise done
	clrw	%d0			| check to see if more to do
	subql	#1,%d0
	jcc	Lmcloop			| yes, keep going...
					| Note: %d0 is now -1!
	movql	#0,%d0			| no terminator found, return NULL
Lmcbail:
#ifdef __SVR4_ABI__
	movl	%d0,%a0			| XXX maybe use lea to avoid stall?
#endif
	rts

Lmcnzdone:
	movl	%sp@+,%d2		| restore scratch register
Lmcdone:
	movl	%a0,%d0
	rts