/* $NetBSD: bzero.S,v 1.6 2013/09/07 19:06:29 chs 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: @(#)bzero.s 5.1 (Berkeley) 5/12/90")
#else
RCSID("$NetBSD: bzero.S,v 1.6 2013/09/07 19:06:29 chs Exp $")
#endif
#endif /* LIBC_SCCS and not lint */
ENTRY(bzero)
movl %d2,-(%sp)
movl 8(%sp),%a0 | destination
movl 12(%sp),%d1 | count
clrl %d2
/*
* It isn't worth the overhead of aligning to {long}word boundries
* if the string is too short.
*/
cmpl #8,%d1
jlt .Lbzbyte
/* word align */
movl %a0,%d0
btst #0,%d0 | if (dst & 1)
jeq .Lbzalgndw |
movb %d2,(%a0)+ | *(char *)dst++ = 0
subql #1,%d1 | len--
.Lbzalgndw:
/* long word align */
btst #1,%d0 | if (dst & 2)
jeq .Lbzalgndl |
movw %d2,(%a0)+ | *(short *)dst++ = 0
subql #2,%d1 | len -= 2
.Lbzalgndl:
/* zero by 8 longwords */
movel %d1,%d0
lsrl #5,%d0 | cnt = len / 32
jeq .Lbzlong | if (cnt)
andl #31,%d1 | len %= 32
subql #1,%d0 | set up for dbf
.Lbz32loop:
movl %d2,(%a0)+ | zero 8 long words
movl %d2,(%a0)+
movl %d2,(%a0)+
movl %d2,(%a0)+
movl %d2,(%a0)+
movl %d2,(%a0)+
movl %d2,(%a0)+
movl %d2,(%a0)+
#ifndef __mcoldfire__
dbf %d0,.Lbz32loop | till done
clrw %d0
#endif
subql #1,%d0
jcc .Lbz32loop
.Lbzlong:
/* copy by longwords */
movel %d1,%d0
lsrl #2,%d0 | cnt = len / 4
jeq .Lbzbyte | if (cnt)
subql #1,%d0 | set up for dbf
.Lbzlloop:
movl %d2,(%a0)+ | clear longwords
#ifdef __mcoldfire__
subql #1,%d0 | decrement
jcc .Lbzlloop | till done
#else
dbf %d0,.Lbzlloop | till done
#endif
andl #3,%d1 | len %= 4
jeq .Lbzdone
subql #1,%d1 | set up for dbf
.Lbzbloop:
movb %d2,(%a0)+ | zero bytes
.Lbzbyte:
#ifdef __mcoldfire__
subql #1,%d0 | decrement
jcc .Lbzbloop | till done
#else
dbf %d1,.Lbzbloop | till done
#endif
.Lbzdone:
movl (%sp)+,%d2
rts
END(bzero)