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Annotation of 43BSDTahoe/lib/libc/compat-sys5/compat-sys5.vax/strchr.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: 
                     18: #if defined(LIBC_SCCS) && !defined(lint)
                     19:        .asciz "@(#)strchr.s    5.2 (Berkeley) 6/27/88"
                     20: #endif /* LIBC_SCCS and not lint */
                     21: 
                     22: #ifdef notdef
                     23: _sccsid:.asciz "@(#)index.s    5.4 (Berkeley) 5/25/88"
                     24: #endif
                     25: 
                     26: /*
                     27:  * Find the first occurence of c in the string cp.
                     28:  * Return pointer to match or null pointer.
                     29:  *
                     30:  * char *
                     31:  * index(cp, c)
                     32:  *     char *cp, c;
                     33:  */
                     34: #include "DEFS.h"
                     35: 
                     36: ENTRY(strchr, 0)
                     37:        movq    4(ap),r1        # r1 = cp; r2 = c
                     38:        tstl    r2              # check for special case c == '\0'
                     39:        bneq    2f
                     40: 1:
                     41:        locc    $0,$65535,(r1)  # just find end of string
                     42:        beql    1b              # still looking
                     43:        movl    r1,r0           # found it
                     44:        ret
                     45: 2:
                     46:        moval   tbl,r3          # r3 = address of table
                     47:        bbss    $0,(r3),5f      # insure not reentering
                     48:        movab   (r3)[r2],r5     # table entry for c
                     49:        incb    (r5)
                     50:        movzwl  $65535,r4       # fast access
                     51: 3:
                     52:        scanc   r4,(r1),(r3),$1 # look for c or '\0'
                     53:        beql    3b              # still looking
                     54:        movl    r1,r0           # return pointer to char
                     55:        tstb    (r0)            #    if have found '\0'
                     56:        bneq    4f
                     57:        clrl    r0              # else return 0
                     58: 4:
                     59:        clrb    (r5)            # clean up table
                     60:        clrb    (r3)
                     61:        ret
                     62: 
                     63:        .data
                     64: tbl:   .space  256
                     65:        .text
                     66: 
                     67: /*
                     68:  * Reentrant, but slower version of index
                     69:  */
                     70: 5:
                     71:        movl    r1,r3
                     72: 6:
                     73:        locc    $0,$65535,(r3)  # look for '\0'
                     74:        bneq    7f
                     75:        locc    r2,$65535,(r3)  # look for c
                     76:        bneq    8f
                     77:        movl    r1,r3           # reset pointer and ...
                     78:        jbr     6b              # ... try again
                     79: 7:
                     80:        subl3   r3,r1,r4        # length of short block
                     81:        incl    r4              # +1 for '\0'
                     82:        locc    r2,r4,(r3)      # look for c
                     83:        bneq    8f
                     84:        ret
                     85: 8:
                     86:        movl    r1,r0           # return pointer to char
                     87:        ret

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