/*      $NetBSD: str.S,v 1.6 2017/05/22 17:00:19 ragge Exp $ */
/*
 * Copyright (c) 1996 Ludd, University of Lule}, Sweden.
 * All rights reserved.
 *
 * 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 AUTHOR ``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 AUTHOR 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.
 */

/*
 * Small versions of the most common functions not using any
 * emulated instructions.
 */

#include "asm.h"

/*
 * atoi() used in devopen.
 */
ENTRY(atoi, 0)
        movl    4(%ap),%r1
        clrl    %r0

2:      movzbl  (%r1)+,%r2
        cmpb    %r2,$48
        blss    1f
        cmpb    %r2,$57
        bgtr    1f
        subl2   $48,%r2
        mull2   $10,%r0
        addl2   %r2,%r0
        brb     2b
1:      ret

/*
 * strchr() small and easy.
 */
ENTRY(strchr, 0)
        movq    4(%ap),%r0
1:      cmpb    (%r0), 8(%ap)
        beql    2f
        tstb    (%r0)+
        bneq    1b
        clrl    %r0
2:      ret

/*
 * cmpc3 is emulated on MVII.
 */
ENTRY(memcmp, 0)
        brb     10f
ENTRY(bcmp, 0)
10:     movl    4(%ap), %r2
        movl    8(%ap), %r1
        movl    12(%ap), %r0
2:      cmpb    (%r2)+, (%r1)+
        bneq    1f
        sobgtr  %r0, 2b
3:      ret
1:      bgtru   5f
        movl    $-1, %r0
        brb     3b
5:      movl    $1, %r0
        ret

/*
 * movc can't do length in excess of 64K, so we shall not use them.
 */
ENTRY(bzero,0)
        movl    4(%ap),%r0
        movl    8(%ap),%r1
1:      clrb    (%r0)+
        sobgtr  %r1,1b
        ret

/*
 * memcpy and bcopy are the same, except for argument order. Silly stuff.
 */
ENTRY(memcpy,0)
        movl    8(%ap),%r0
        movl    4(%ap),%r1
        brb     1f
ENTRY(bcopy,0)
        movl    4(%ap),%r0
        movl    8(%ap),%r1
1:      movl    12(%ap),%r2
        cmpl    %r0,%r1
        bgtru   3f
        addl2   %r2,%r0
        addl2   %r2,%r1
2:      movb    -(%r0),-(%r1)
        sobgtr  %r2,2b
        ret
3:      movb    (%r0)+,(%r1)+
        sobgtr  %r2,3b
        ret

ENTRY(memset,0)
        movl    4(%ap),%r0
        movl    12(%ap),%r1
1:      movb    8(%ap),(%r0)+
        sobgtr  %r1,1b
        ret

ENTRY(strlen, 0)
        movl    4(%ap), %r0
1:      tstb    (%r0)+
        bneq    1b
        decl    %r0
        subl2   4(%ap), %r0
        ret

ENTRY(strncmp, 0)
        movl    12(%ap), %r3
        bneq    5f
        brb     4f

ENTRY(strcmp, 0)
        movl    $250, %r3       # max string len to compare
5:      movl    4(%ap), %r2
        movl    8(%ap), %r1
        movl    $1, %r0

2:      cmpb    (%r2),(%r1)+
        bneq    1f              # something differ
        tstb    (%r2)+
        beql    4f              # continue, strings unequal
        decl    %r3             # max string len encountered?
        bneq    2b

4:      clrl    %r0             # We are done, strings equal.
        ret

1:      bgtru   3f
        mnegl   %r0, %r0
3:      ret

ENTRY(strncpy, 0)
        movl    4(%ap), %r1
        movl    8(%ap), %r2
        movl    12(%ap), %r3
        bleq    2f

1:      movb    (%r2)+, (%r1)+
        beql    2f
        sobgtr  %r3,1b
        ret
2:      decl    %r1
3:      clrb    (%r1)+
        sobgtr  %r3,3b
        ret

ENTRY(strcat, 0)
        pushl   4(%ap)
        calls   $1,_C_LABEL(strlen)
        addl2   4(%ap),%r0
        movl    8(%ap),%r1
1:      movb    (%r1)+,(%r0)+
        bneq    1b
        ret

ENTRY(setjmp, 0)
        movl    4(%ap), %r0
        movl    8(%fp), (%r0)
        movl    12(%fp), 4(%r0)
        movl    16(%fp), 8(%r0)
        addl3   %fp,$28,12(%r0)
        clrl    %r0
        ret

ENTRY(longjmp, 0)
        movl    4(%ap), %r1
        movl    8(%ap), %r0
        movl    (%r1), %ap
        movl    4(%r1), %fp
        movl    12(%r1), %sp
        jmp     *8(%r1)