minix/common/lib/libc/arch/m68k/string/bcopy.S

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/* $NetBSD: bcopy.S,v 1.2 2008/04/28 20:22:52 martin Exp $ */
/*-
* Copyright (c) 1997 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by J.T. Conklin.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/
/*-
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* the Systems Programming Group of the University of Utah Computer
* Science Department.
*
* 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. 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.
*/
#include <machine/asm.h>
#if defined(LIBC_SCCS) && !defined(lint)
#if 0
RCSID("from: @(#)bcopy.s 5.1 (Berkeley) 5/12/90")
#else
RCSID("$NetBSD: bcopy.S,v 1.2 2008/04/28 20:22:52 martin Exp $")
#endif
#endif /* LIBC_SCCS and not lint */
#ifdef MEMCOPY
ENTRY(memcpy)
#else
#ifdef MEMMOVE
ENTRY(memmove)
#else
ENTRY(bcopy)
#endif
#endif
#if defined(MEMCOPY) || defined(MEMMOVE)
movl %sp@(4),%a1 | dest address
movl %sp@(8),%a0 | src address
#else
movl %sp@(4),%a0 | src address
movl %sp@(8),%a1 | dest address
#endif
movl %sp@(12),%d1 | count
cmpl %a1,%a0 | src after dest?
jlt Lbcback | yes, must copy backwards
/*
* It isn't worth the overhead of aligning to {long}word boundries
* if the string is too short.
*/
cmpl #8,%d1
jlt Lbcfbyte
#ifdef __mc68010__
/*
* The 68010 cannot access a word or long on an odd boundary,
* period. If the source and the destination addresses aren't
* of the same evenness, we're forced to do a bytewise copy.
*/
movl %a0,%d0
addl %a1,%d0
btst #0,%d0
jne Lbcfbyte
#endif /* __mc68010__ */
/* word align */
movl %a1,%d0
btst #0,%d0 | if (dst & 1)
jeq Lbcfalgndw |
movb %a0@+,%a1@+ | *(char *)dst++ = *(char *) src++
subql #1,%d1 | len--
Lbcfalgndw:
/* long word align */
btst #1,%d0 | if (dst & 2)
jeq Lbcfalgndl
movw %a0@+,%a1@+ | *(short *)dst++ = *(short *) dst++
subql #2,%d1 | len -= 2
Lbcfalgndl:
/* copy by 8 longwords */
movel %d1,%d0
lsrl #5,%d0 | cnt = len / 32
jeq Lbcflong | if (cnt)
andl #31,%d1 | len %= 32
subql #1,%d0 | set up for dbf
Lbcf32loop:
movl %a0@+,%a1@+ | copy 8 long words
movl %a0@+,%a1@+
movl %a0@+,%a1@+
movl %a0@+,%a1@+
movl %a0@+,%a1@+
movl %a0@+,%a1@+
movl %a0@+,%a1@+
movl %a0@+,%a1@+
dbf %d0,Lbcf32loop | till done
clrw %d0
subql #1,%d0
jcc Lbcf32loop
Lbcflong:
/* copy by longwords */
movel %d1,%d0
lsrl #2,%d0 | cnt = len / 4
jeq Lbcfbyte | if (cnt)
subql #1,%d0 | set up for dbf
Lbcflloop:
movl %a0@+,%a1@+ | copy longwords
dbf %d0,Lbcflloop | til done
andl #3,%d1 | len %= 4
jeq Lbcdone
subql #1,%d1 | set up for dbf
Lbcfbloop:
movb %a0@+,%a1@+ | copy bytes
Lbcfbyte:
dbf %d1,Lbcfbloop | till done
Lbcdone:
#if defined(MEMCOPY) || defined(MEMMOVE)
movl %sp@(4),%d0 | dest address
#if defined(__SVR4_ABI__)
moveal %d0,%a0
#endif
#endif
rts
Lbcback:
addl %d1,%a0 | src pointer to end
addl %d1,%a1 | dest pointer to end
/*
* It isn't worth the overhead of aligning to {long}word boundries
* if the string is too short.
*/
cmpl #8,%d1
jlt Lbcbbyte
#ifdef __mc68010__
/*
* The 68010 cannot access a word or long on an odd boundary,
* period. If the source and the destination addresses aren't
* of the same evenness, we're forced to do a bytewise copy.
*/
movl %a0,%d0
addl %a1,%d0
btst #0,%d0
jne Lbcbbyte
#endif /* __mc68010__ */
/* word align */
movl %a1,%d0
btst #0,%d0 | if (dst & 1)
jeq Lbcbalgndw |
movb %a0@-,%a1@- | *(char *)dst-- = *(char *) src--
subql #1,%d1 | len--
Lbcbalgndw:
/* long word align */
btst #1,%d0 | if (dst & 2)
jeq Lbcbalgndl
movw %a0@-,%a1@- | *(short *)dst-- = *(short *) dst--
subql #2,%d1 | len -= 2
Lbcbalgndl:
/* copy by 8 longwords */
movel %d1,%d0
lsrl #5,%d0 | cnt = len / 32
jeq Lbcblong | if (cnt)
andl #31,%d1 | len %= 32
subql #1,%d0 | set up for dbf
Lbcb32loop:
movl %a0@-,%a1@- | copy 8 long words
movl %a0@-,%a1@-
movl %a0@-,%a1@-
movl %a0@-,%a1@-
movl %a0@-,%a1@-
movl %a0@-,%a1@-
movl %a0@-,%a1@-
movl %a0@-,%a1@-
dbf %d0,Lbcb32loop | till done
clrw %d0
subql #1,%d0
jcc Lbcb32loop
Lbcblong:
/* copy by longwords */
movel %d1,%d0
lsrl #2,%d0 | cnt = len / 4
jeq Lbcbbyte | if (cnt)
subql #1,%d0 | set up for dbf
Lbcblloop:
movl %a0@-,%a1@- | copy longwords
dbf %d0,Lbcblloop | til done
andl #3,%d1 | len %= 4
jeq Lbcdone
subql #1,%d1 | set up for dbf
Lbcbbloop:
movb %a0@-,%a1@- | copy bytes
Lbcbbyte:
dbf %d1,Lbcbbloop | till done
#if defined(MEMCOPY) || defined(MEMMOVE)
movl %sp@(4),%d0 | dest address
#if defined(__SVR4_ABI__)
moveal %d0,%a0
#endif
#endif
rts