usr/src/lib/libc/vax/string/bcopy.s

/*
 * Copyright (c) 1983 Regents of the University of California.
 * All rights reserved.
 *
 * %sccs.include.redist.c%
 */

#if defined(LIBC_SCCS) && !defined(lint)
        .asciz "@(#)bcopy.s     5.6 (Berkeley) %G%"
#endif /* LIBC_SCCS and not lint */

/* bcopy(from, to, size) */

#include "DEFS.h"

ENTRY(bcopy, R6)
        movl    4(ap),r1
        movl    8(ap),r3
        movl    12(ap),r6
        cmpl    r1,r3
        bgtr    2f              # normal forward case
        blss    3f              # overlapping, must do backwards
        ret                     # equal, nothing to do
1:
        subl2   r0,r6
        movc3   r0,(r1),(r3)
2:
        movzwl  $65535,r0
        cmpl    r6,r0
        jgtr    1b
        movc3   r6,(r1),(r3)
        ret
3:
        addl2   r6,r1
        addl2   r6,r3
        movzwl  $65535,r0
        jbr     5f
4:
        subl2   r0,r6
        subl2   r0,r1
        subl2   r0,r3
        movc3   r0,(r1),(r3)
        movzwl  $65535,r0
        subl2   r0,r1
        subl2   r0,r3
5:
        cmpl    r6,r0
        jgtr    4b
        subl2   r6,r1
        subl2   r6,r3
        movc3   r6,(r1),(r3)
        ret