sysdeps/vax/bcopy.s

   1 /*
   2  * Copyright (c) 1983 Regents of the University of California.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 4. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29
  30 #if defined(LIBC_SCCS) && !defined(lint)
  31         .asciz "@(#)bcopy.s     5.6 (Berkeley) 6/1/90"
  32 #endif /* LIBC_SCCS and not lint */
  33
  34 /* bcopy(from, to, size) */
  35
  36 #include "DEFS.h"
  37
  38 ENTRY(bcopy, R6)
  39         movl    4(ap),r1
  40         movl    8(ap),r3
  41         movl    12(ap),r6
  42         cmpl    r1,r3
  43         bgtr    2f              # normal forward case
  44         blss    3f              # overlapping, must do backwards
  45         ret                     # equal, nothing to do
  46 1:
  47         subl2   r0,r6
  48         movc3   r0,(r1),(r3)
  49 2:
  50         movzwl  $65535,r0
  51         cmpl    r6,r0
  52         jgtr    1b
  53         movc3   r6,(r1),(r3)
  54         ret
  55 3:
  56         addl2   r6,r1
  57         addl2   r6,r3
  58         movzwl  $65535,r0
  59         jbr     5f
  60 4:
  61         subl2   r0,r6
  62         subl2   r0,r1
  63         subl2   r0,r3
  64         movc3   r0,(r1),(r3)
  65         movzwl  $65535,r0
  66         subl2   r0,r1
  67         subl2   r0,r3
  68 5:
  69         cmpl    r6,r0
  70         jgtr    4b
  71         subl2   r6,r1
  72         subl2   r6,r3
  73         movc3   r6,(r1),(r3)
  74         ret