sysdeps/vax/memcmp.s

   1 /*-
   2  * Copyright (c) 1990 The 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  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #if defined(LIBC_SCCS) && !defined(lint)
  35         .asciz "@(#)memcmp.s    5.1 (Berkeley) 5/15/90"
  36 #endif /* LIBC_SCCS and not lint */
  37
  38 /* int memcmp(s1, s2, n) */
  39
  40 #include "DEFS.h"
  41
  42 ENTRY(memcmp, 0)
  43         movl    4(ap),r1        /* r1 = s1 */
  44         movq    8(ap),r3        /* r3 = s2; r4 = n */
  45         movzwl  $65535,r5
  46 0:
  47         cmpl    r4,r5
  48         jgtru   3f              /* handle stupid cmpc3 limitation */
  49         cmpc3   r4,(r1),(r3)    /* compare */
  50         beql    2f              /* done if same (r0 = 0) */
  51 1:
  52         movzbl  (r1),r0
  53         movzbl  (r3),r2
  54         subl2   r2,r0           /* return *s1 - *s2; s1,s2 unsigned chars */
  55 2:
  56         ret
  57 3:
  58         subl2   r5,r4           /* do 64K; adjust count */
  59         cmpc3   r5,(r1),(r3)
  60         jeql    0b              /* loop if same */
  61         jbr     1b