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Annotation of 43BSDTahoe/lib/libc/gen/gen.tahoe/bcopy.s, revision 1.1.1.1

1.1       root        1: /*
                      2:  * Copyright (c) 1988 Regents of the University of California.
                      3:  * All rights reserved.
                      4:  *
                      5:  * Redistribution and use in source and binary forms are permitted
                      6:  * provided that the above copyright notice and this paragraph are
                      7:  * duplicated in all such forms and that any documentation,
                      8:  * advertising materials, and other materials related to such
                      9:  * distribution and use acknowledge that the software was developed
                     10:  * by the University of California, Berkeley.  The name of the
                     11:  * University may not be used to endorse or promote products derived
                     12:  * from this software without specific prior written permission.
                     13:  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
                     14:  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
                     15:  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
                     16:  *
                     17:  * This code is derived from software contributed to Berkeley by
                     18:  * Computer Consoles Inc.
                     19:  */
                     20: 
                     21: #if defined(LIBC_SCCS) && !defined(lint)
                     22:        .asciz "@(#)bcopy.s     1.3 (Berkeley) 6/27/88"
                     23: #endif /* LIBC_SCCS and not lint */
                     24: 
                     25: /* bcopy(from, to, size) */
                     26: #include "DEFS.h"
                     27: 
                     28: ENTRY(bcopy, 0)
                     29:        movl    4(fp),r0
                     30:        movl    8(fp),r1
                     31:        movl    12(fp),r2
                     32:        cmpl    r0,r1
                     33:        bgtru   1f              # normal forward case
                     34:        beql    2f              # equal, nothing to do
                     35:        addl2   r2,r0           # may be overlapping
                     36:        cmpl    r0,r1
                     37:        bgtru   3f
                     38:        subl2   r2,r0           # normal forward case
                     39: 1:
                     40:        movblk
                     41: 2:
                     42:        ret
                     43: 3:
                     44:        addl2   r2,r1           # overlapping, must do backwards
                     45:        subl3   r0,r1,r3
                     46:        movl    r2,r4
                     47:        jbr     5f
                     48: 4:
                     49:        subl2   r3,r0
                     50:        subl2   r3,r1
                     51:        movl    r3,r2
                     52:        movblk
                     53:        subl2   r3,r0
                     54:        subl2   r3,r1
                     55:        subl2   r3,r4
                     56: 5:
                     57:        cmpl    r4,r3
                     58:        jgtr    4b
                     59:        movl    r4,r2
                     60:        subl2   r2,r0
                     61:        subl2   r2,r1
                     62:        movblk
                     63:        ret

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