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bcmp.S revision 1.1
      1 /*	$NetBSD: bcmp.S,v 1.1 2005/12/20 19:28:49 christos Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1997 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by J.T. Conklin.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  * 3. All advertising materials mentioning features or use of this software
     19  *    must display the following acknowledgement:
     20  *        This product includes software developed by the NetBSD
     21  *        Foundation, Inc. and its contributors.
     22  * 4. Neither the name of The NetBSD Foundation nor the names of its
     23  *    contributors may be used to endorse or promote products derived
     24  *    from this software without specific prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     36  * POSSIBILITY OF SUCH DAMAGE.
     37  */
     38 
     39 /*-
     40  * Copyright (c) 1990 The Regents of the University of California.
     41  * All rights reserved.
     42  *
     43  * This code is derived from software contributed to Berkeley by
     44  * the Systems Programming Group of the University of Utah Computer
     45  * Science Department.
     46  *
     47  * Redistribution and use in source and binary forms, with or without
     48  * modification, are permitted provided that the following conditions
     49  * are met:
     50  * 1. Redistributions of source code must retain the above copyright
     51  *    notice, this list of conditions and the following disclaimer.
     52  * 2. Redistributions in binary form must reproduce the above copyright
     53  *    notice, this list of conditions and the following disclaimer in the
     54  *    documentation and/or other materials provided with the distribution.
     55  * 3. Neither the name of the University nor the names of its contributors
     56  *    may be used to endorse or promote products derived from this software
     57  *    without specific prior written permission.
     58  *
     59  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     60  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     61  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     62  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     63  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     64  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     65  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     66  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     67  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     68  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     69  * SUCH DAMAGE.
     70  */
     71 
     72 #include <machine/asm.h>
     73 
     74 #if defined(LIBC_SCCS) && !defined(lint)
     75 #if 0
     76 	RCSID("from: @(#)bcmp.s 5.1 (Berkeley) 5/12/90")
     77 #else
     78 	RCSID("$NetBSD: bcmp.S,v 1.1 2005/12/20 19:28:49 christos Exp $")
     79 #endif
     80 #endif /* LIBC_SCCS and not lint */
     81 
     82 ENTRY(bcmp)
     83 	movl	%sp@(4),%a0		| string 1
     84 	movl	%sp@(8),%a1		| string 2
     85 	movl	%sp@(12),%d1		| length
     86 
     87 	/*
     88 	 * It isn't worth the overhead of aligning to {long}word boundries
     89 	 * if the string is too short.
     90 	 */
     91 	cmpl	#8,%d1
     92 	jlt	Lbcbyte
     93 
     94 #ifdef	__mc68010__
     95 	/*
     96 	 * The 68010 cannot access a word or long on an odd boundary,
     97 	 * period.  If the source and the destination addresses aren't
     98 	 * of the same evenness, we're forced to do a bytewise compare.
     99 	 */
    100 	movl	%a0,%d0
    101 	addl	%a1,%d0
    102 	btst	#0,%d0
    103 	jne	Lbcbyte
    104 #endif	/* __mc68010__ */
    105 
    106 	/* word align */
    107 	movl	%a0,%d0
    108 	btst	#0,%d0
    109 	jeq	Lbcalgndw
    110 	cmpmb	%a0@+,%a1@+
    111 	jne	Lbcnoteq
    112 	subql	#1,%d1
    113 Lbcalgndw:
    114 	/* long word align */
    115 	btst	#1,%d0
    116 	jeq	Lbcalgndl
    117 	cmpmw	%a0@+,%a1@+
    118 	jne	Lbcnoteq
    119 	subql	#2,%d1
    120 Lbcalgndl:
    121 	/* compare by 8 longwords */
    122 	movl	%d1,%d0
    123 	lsrl	#5,%d0			| cnt = len / 32
    124 	jeq	Lbclong			| if (cnt)
    125 	andl	#31,%d1			|	len %= 32
    126 	subql	#1,%d0			|	set up for dbf
    127 Lbc32loop:
    128 	cmpml	%a0@+,%a1@+		|	compare 8 longwords
    129 	jne	Lbcnoteq		|	not equal, return non-zero
    130 	cmpml	%a0@+,%a1@+
    131 	jne	Lbcnoteq
    132 	cmpml	%a0@+,%a1@+
    133 	jne	Lbcnoteq
    134 	cmpml	%a0@+,%a1@+
    135 	jne	Lbcnoteq
    136 	cmpml	%a0@+,%a1@+
    137 	jne	Lbcnoteq
    138 	cmpml	%a0@+,%a1@+
    139 	jne	Lbcnoteq
    140 	cmpml	%a0@+,%a1@+
    141 	jne	Lbcnoteq
    142 	cmpml	%a0@+,%a1@+
    143 	jne	Lbcnoteq
    144 	dbf	%d0,Lbc32loop		|	till done
    145 	clrw	%d0
    146 	subql	#1,%d0
    147 	jcc	Lbc32loop
    148 
    149 Lbclong:
    150 	/* compare by longwords */
    151 	movl	%d1,%d0
    152 	lsrl	#2,%d0			| cnt = len / 4
    153 	jeq	Lbcbyte			| if (cnt)
    154 	subql	#1,%d0			|	set up for dbf
    155 Lbclloop:
    156 	cmpml	%a0@+,%a1@+		|	compare a longword
    157 	jne	Lbcnoteq		|	not equal, return non-zero
    158 	dbf	%d0,Lbclloop		|	till done
    159 	andl	#3,%d1			|	len %= 4
    160 	jeq	Lbcdone
    161 
    162 	subql	#1,%d1			| set up for dbf
    163 Lbcbloop:
    164 	cmpmb	%a0@+,%a1@+		| compare a byte
    165 	jne	Lbcnoteq		| not equal, return non-zero
    166 Lbcbyte:
    167 	dbf	%d1,Lbcbloop
    168 Lbcdone:
    169 	movql	#0,%d0
    170 	rts
    171 
    172 Lbcnoteq:
    173 	movql	#1,%d0
    174 	rts
    175