4.3BSD - /usr/src/lib/libc/vax/gen/rindex.s

   1: /*
   2:  * Copyright (c) 1983 Regents of the University of California.
   3:  * All rights reserved.  The Berkeley software License Agreement
   4:  * specifies the terms and conditions for redistribution.
   5:  */
   6: 
   7: #ifdef LIBC_SCCS
   8:         .asciz  "@(#)rindex.s	5.3 (Berkeley) 3/9/86"
   9: #endif LIBC_SCCS
  10: 
  11: /*
  12:  * Find the last occurence of c in the string cp.
  13:  * Return pointer to match or null pointer.
  14:  *
  15:  * char *
  16:  * rindex(cp, c)
  17:  *	char *cp, c;
  18:  */
  19: #include "DEFS.h"
  20: 
  21: ENTRY(rindex, 0)
  22:         movq    4(ap),r1        # r1 = cp; r2 = c
  23:         tstl    r2              # check for special case c == '\0'
  24:         bneq    2f
  25: 1:
  26:         locc    $0,$65535,(r1)  # just find end of string
  27:         beql    1b              # still looking
  28:         movl    r1,r0           # found it
  29:         ret
  30: 2:
  31:         moval   tbl,r3          # r3 = address of table
  32:         bbss    $0,(r3),5f      # insure not reentering
  33:         movab   (r3)[r2],r5     # table entry for c
  34:         incb    (r5)
  35:         clrl    r4              # last found
  36: 3:
  37:         scanc   $65535,(r1),(r3),$1     # look for c or '\0'
  38:         beql    3b              # keep looking
  39:         tstb    (r1)            # if have found '\0'
  40:         beql    4f              #    we are done
  41:         movl    r1,r4           # save most recently found
  42:         incl    r1              # skip over character
  43:         jbr     3b              # keep looking
  44: 4:
  45:         movl    r4,r0           # return last found (if any)
  46:         clrb    (r5)            # clean up table
  47:         clrb    (r3)
  48:         ret
  49: 
  50:         .data
  51: tbl:    .space  256
  52:         .text
  53: 
  54: /*
  55:  * Reentrant, but slower version of rindex
  56:  */
  57: 5:
  58:         movl    r1,r3
  59:         clrl    r4              # r4 = pointer to last match
  60: 6:
  61:         locc    $0,$65535,(r3)  # look for '\0'
  62:         bneq    8f
  63:         decw    r0              # r0 = 65535
  64: 1:
  65:         locc    r2,r0,(r3)      # look for c
  66:         bneq    7f
  67:         movl    r1,r3           # reset pointer and ...
  68:         jbr     6b              # ... try again
  69: 7:
  70:         movl    r1,r4           # stash pointer ...
  71:         addl3   $1,r1,r3        # ... skip over match and ...
  72:         decl    r0              # ... decrement count
  73:         jbr     6b              # ... try again
  74: 8:
  75:         subl3   r3,r1,r0        # length of short block
  76:         incl    r0              # +1 for '\0'
  77: 9:
  78:         locc    r2,r0,(r3)      # look for c
  79:         beql    0f
  80:         movl    r1,r4           # stash pointer ...
  81:         addl3   $1,r1,r3        # ... skip over match ...
  82:         decl    r0              # ... adjust count and ...
  83:         jbr     9b              # ... try again
  84: 0:
  85:         movl    r4,r0           # return stashed pointer
  86:         ret

Defined functions

Defined variables