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      1 /*	$NetBSD: bcmp.S,v 1.6 2013/09/07 19:06:29 chs 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  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 /*-
     33  * Copyright (c) 1990 The Regents of the University of California.
     34  * All rights reserved.
     35  *
     36  * This code is derived from software contributed to Berkeley by
     37  * the Systems Programming Group of the University of Utah Computer
     38  * Science Department.
     39  *
     40  * Redistribution and use in source and binary forms, with or without
     41  * modification, are permitted provided that the following conditions
     42  * are met:
     43  * 1. Redistributions of source code must retain the above copyright
     44  *    notice, this list of conditions and the following disclaimer.
     45  * 2. Redistributions in binary form must reproduce the above copyright
     46  *    notice, this list of conditions and the following disclaimer in the
     47  *    documentation and/or other materials provided with the distribution.
     48  * 3. Neither the name of the University nor the names of its contributors
     49  *    may be used to endorse or promote products derived from this software
     50  *    without specific prior written permission.
     51  *
     52  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     53  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     54  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     55  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     56  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     57  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     58  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     59  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     60  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     61  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     62  * SUCH DAMAGE.
     63  */
     64 
     65 #include <machine/asm.h>
     66 
     67 #if defined(LIBC_SCCS) && !defined(lint)
     68 #if 0
     69 	RCSID("from: @(#)bcmp.s 5.1 (Berkeley) 5/12/90")
     70 #else
     71 	RCSID("$NetBSD: bcmp.S,v 1.6 2013/09/07 19:06:29 chs Exp $")
     72 #endif
     73 #endif /* LIBC_SCCS and not lint */
     74 
     75 #ifdef __mcoldfire__
     76 #define	CMPMB(a,b)	movb b,%d2; cmpb a,%d2
     77 #define	CMPMW(a,b)	movw b,%d2; cmpw a,%d2
     78 #define	CMPML(a,b)	movl b,%d2; cmpl a,%d2
     79 #else
     80 #define	CMPMB(a,b)	cmpmb a,b
     81 #define	CMPMW(a,b)	cmpmw a,b
     82 #define	CMPML(a,b)	cmpml a,b
     83 #endif
     84 
     85 ENTRY(bcmp)
     86 	movl	4(%sp),%a0		| string 1
     87 	movl	8(%sp),%a1		| string 2
     88 	movl	12(%sp),%d1		| length
     89 #ifdef __mcoldfire__
     90 	movl	%d2,-(%sp)		| save temp
     91 #endif
     92 
     93 	/*
     94 	 * It isn't worth the overhead of aligning to {long}word boundries
     95 	 * if the string is too short.
     96 	 */
     97 	cmpl	#8,%d1
     98 	jlt	.Lbcbyte
     99 
    100 #ifdef	__mc68010__
    101 	/*
    102 	 * The 68010 cannot access a word or long on an odd boundary,
    103 	 * period.  If the source and the destination addresses aren't
    104 	 * of the same evenness, we're forced to do a bytewise compare.
    105 	 */
    106 	movl	%a0,%d0
    107 	addl	%a1,%d0
    108 	btst	#0,%d0
    109 	jne	.Lbcbyte
    110 #endif	/* __mc68010__ */
    111 
    112 	/* word align */
    113 	movl	%a0,%d0
    114 	btst	#0,%d0
    115 	jeq	.Lbcalgndw
    116 	CMPMB((%a0)+,(%a1)+)
    117 	jne	.Lbcnoteq
    118 	subql	#1,%d1
    119 .Lbcalgndw:
    120 	/* long word align */
    121 	btst	#1,%d0
    122 	jeq	.Lbcalgndl
    123 	CMPMW((%a0)+,(%a1)+)
    124 	jne	.Lbcnoteq
    125 	subql	#2,%d1
    126 .Lbcalgndl:
    127 	/* compare by 8 longwords */
    128 	movl	%d1,%d0
    129 	lsrl	#5,%d0			| cnt = len / 32
    130 	jeq	.Lbclong			| if (cnt)
    131 	andl	#31,%d1			|	len %= 32
    132 	subql	#1,%d0			|	set up for dbf
    133 .Lbc32loop:
    134 	CMPML((%a0)+,(%a1)+)		|	compare 1 of 8 longwords
    135 	jne	.Lbcnoteq		|	not equal, return non-zero
    136 	CMPML((%a0)+,(%a1)+)		|	compare 2 of 8 longwords
    137 	jne	.Lbcnoteq
    138 	CMPML((%a0)+,(%a1)+)		|	compare 3 of 8 longwords
    139 	jne	.Lbcnoteq
    140 	CMPML((%a0)+,(%a1)+)		|	compare 4 of 8 longwords
    141 	jne	.Lbcnoteq
    142 	CMPML((%a0)+,(%a1)+)		|	compare 5 of 8 longwords
    143 	jne	.Lbcnoteq
    144 	CMPML((%a0)+,(%a1)+)		|	compare 6 of 8 longwords
    145 	jne	.Lbcnoteq
    146 	CMPML((%a0)+,(%a1)+)		|	compare 7 of 8 longwords
    147 	jne	.Lbcnoteq
    148 	CMPML((%a0)+,(%a1)+)		|	compare 8 of 8 longwords
    149 	jne	.Lbcnoteq
    150 #ifndef __mcoldfire__
    151 	dbf	%d0,.Lbc32loop		|	till done
    152 	clrw	%d0
    153 #endif
    154 	subql	#1,%d0
    155 	jcc	.Lbc32loop
    156 
    157 .Lbclong:
    158 	/* compare by longwords */
    159 	movl	%d1,%d0
    160 	lsrl	#2,%d0			| cnt = len / 4
    161 	jeq	.Lbcbyte			| if (cnt)
    162 	subql	#1,%d0			|	set up for dbf
    163 .Lbclloop:
    164 	CMPML((%a0)+,(%a1)+)		|	compare a longword
    165 	jne	.Lbcnoteq		|	not equal, return non-zero
    166 #ifdef __mcoldfire__
    167 	subql	#1,%d0			|	decrement
    168 	jcc	.Lbclloop		|	till done
    169 #else
    170 	dbf	%d0,.Lbclloop		|	till done
    171 #endif
    172 	andl	#3,%d1			|	len %= 4
    173 	jeq	.Lbcdone
    174 
    175 	subql	#1,%d1			| set up for dbf
    176 .Lbcbloop:
    177 	CMPMB((%a0)+,(%a1)+)		| compare a byte
    178 	jne	.Lbcnoteq		| not equal, return non-zero
    179 .Lbcbyte:
    180 #ifdef __mcoldfire__
    181 	subql	#1,%d0			|	decrement
    182 	jcc	.Lbcbloop		|	till done
    183 #else
    184 	dbf	%d1,.Lbcbloop
    185 #endif
    186 .Lbcdone:
    187 #ifdef __mcoldfire__
    188 	movl	(%sp)+,%d2		| restore temp
    189 #endif
    190 	movql	#0,%d0
    191 	rts
    192 
    193 .Lbcnoteq:
    194 	movql	#1,%d0
    195 	rts
    196 END(bcmp)
    197