/*      $NetBSD: bcmp.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: @(#)bcmp.s 5.1 (Berkeley) 5/12/90")
#else
       RCSID("$NetBSD: bcmp.S,v 1.6 2013/09/07 19:06:29 chs Exp $")
#endif
#endif /* LIBC_SCCS and not lint */

#ifdef __mcoldfire__
#define CMPMB(a,b)      movb b,%d2; cmpb a,%d2
#define CMPMW(a,b)      movw b,%d2; cmpw a,%d2
#define CMPML(a,b)      movl b,%d2; cmpl a,%d2
#else
#define CMPMB(a,b)      cmpmb a,b
#define CMPMW(a,b)      cmpmw a,b
#define CMPML(a,b)      cmpml a,b
#endif

ENTRY(bcmp)
       movl    4(%sp),%a0              | string 1
       movl    8(%sp),%a1              | string 2
       movl    12(%sp),%d1             | length
#ifdef __mcoldfire__
       movl    %d2,-(%sp)              | save temp
#endif

       /*
        * It isn't worth the overhead of aligning to {long}word boundries
        * if the string is too short.
        */
       cmpl    #8,%d1
       jlt     .Lbcbyte

#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 compare.
        */
       movl    %a0,%d0
       addl    %a1,%d0
       btst    #0,%d0
       jne     .Lbcbyte
#endif  /* __mc68010__ */

       /* word align */
       movl    %a0,%d0
       btst    #0,%d0
       jeq     .Lbcalgndw
       CMPMB((%a0)+,(%a1)+)
       jne     .Lbcnoteq
       subql   #1,%d1
Lbcalgndw:
       /* long word align */
       btst    #1,%d0
       jeq     .Lbcalgndl
       CMPMW((%a0)+,(%a1)+)
       jne     .Lbcnoteq
       subql   #2,%d1
Lbcalgndl:
       /* compare by 8 longwords */
       movl    %d1,%d0
       lsrl    #5,%d0                  | cnt = len / 32
       jeq     .Lbclong                        | if (cnt)
       andl    #31,%d1                 |       len %= 32
       subql   #1,%d0                  |       set up for dbf
Lbc32loop:
       CMPML((%a0)+,(%a1)+)            |       compare 1 of 8 longwords
       jne     .Lbcnoteq               |       not equal, return non-zero
       CMPML((%a0)+,(%a1)+)            |       compare 2 of 8 longwords
       jne     .Lbcnoteq
       CMPML((%a0)+,(%a1)+)            |       compare 3 of 8 longwords
       jne     .Lbcnoteq
       CMPML((%a0)+,(%a1)+)            |       compare 4 of 8 longwords
       jne     .Lbcnoteq
       CMPML((%a0)+,(%a1)+)            |       compare 5 of 8 longwords
       jne     .Lbcnoteq
       CMPML((%a0)+,(%a1)+)            |       compare 6 of 8 longwords
       jne     .Lbcnoteq
       CMPML((%a0)+,(%a1)+)            |       compare 7 of 8 longwords
       jne     .Lbcnoteq
       CMPML((%a0)+,(%a1)+)            |       compare 8 of 8 longwords
       jne     .Lbcnoteq
#ifndef __mcoldfire__
       dbf     %d0,.Lbc32loop          |       till done
       clrw    %d0
#endif
       subql   #1,%d0
       jcc     .Lbc32loop

Lbclong:
       /* compare by longwords */
       movl    %d1,%d0
       lsrl    #2,%d0                  | cnt = len / 4
       jeq     .Lbcbyte                        | if (cnt)
       subql   #1,%d0                  |       set up for dbf
Lbclloop:
       CMPML((%a0)+,(%a1)+)            |       compare a longword
       jne     .Lbcnoteq               |       not equal, return non-zero
#ifdef __mcoldfire__
       subql   #1,%d0                  |       decrement
       jcc     .Lbclloop               |       till done
#else
       dbf     %d0,.Lbclloop           |       till done
#endif
       andl    #3,%d1                  |       len %= 4
       jeq     .Lbcdone

       subql   #1,%d1                  | set up for dbf
Lbcbloop:
       CMPMB((%a0)+,(%a1)+)            | compare a byte
       jne     .Lbcnoteq               | not equal, return non-zero
Lbcbyte:
#ifdef __mcoldfire__
       subql   #1,%d0                  |       decrement
       jcc     .Lbcbloop               |       till done
#else
       dbf     %d1,.Lbcbloop
#endif
Lbcdone:
#ifdef __mcoldfire__
       movl    (%sp)+,%d2              | restore temp
#endif
       movql   #0,%d0
       rts

Lbcnoteq:
       movql   #1,%d0
       rts
END(bcmp)