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

   1: /*
   2:  * Copyright (c) 1980 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  "@(#)index.s	5.3 (Berkeley) 3/9/86"
   9: #endif LIBC_SCCS
  10: 
  11: /*
  12:  * Find the first occurence of c in the string cp.
  13:  * Return pointer to match or null pointer.
  14:  *
  15:  * char *
  16:  * index(cp, c)
  17:  *	char *cp, c;
  18:  */
  19: #include "DEFS.h"
  20: 
  21: ENTRY(index, 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:         movzwl  $65535,r4       # fast access
  36: 3:
  37:         scanc   r4,(r1),(r3),$1 # look for c or '\0'
  38:         beql    3b              # still looking
  39:         movl    r1,r0           # return pointer to char
  40:         tstb    (r0)            #    if have found '\0'
  41:         bneq    4f
  42:         clrl    r0              # else return 0
  43: 4:
  44:         clrb    (r5)            # clean up table
  45:         clrb    (r3)
  46:         ret
  47: 
  48:         .data
  49: tbl:    .space  256
  50:         .text
  51: 
  52: /*
  53:  * Reentrant, but slower version of index
  54:  */
  55: 5:
  56:         movl    r1,r3
  57: 6:
  58:         locc    $0,$65535,(r3)  # look for '\0'
  59:         bneq    7f
  60:         locc    r2,$65535,(r3)  # look for c
  61:         bneq    8f
  62:         movl    r1,r3           # reset pointer and ...
  63:         jbr     6b              # ... try again
  64: 7:
  65:         subl3   r3,r1,r4        # length of short block
  66:         incl    r4              # +1 for '\0'
  67:         locc    r2,r4,(r3)      # look for c
  68:         bneq    8f
  69:         ret
  70: 8:
  71:         movl    r1,r0           # return pointer to char
  72:         ret

Defined functions

Defined variables