libchill/inbitstr.c

   1 /* Implement POWERSET runtime actions for CHILL.
   2    Copyright (C) 1992,1993 Free Software Foundation, Inc.
   3    Author: Wilfried Moser, et al
   4
   5 This file is part of GNU CC.
   6
   7 GNU CC is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 2, or (at your option)
  10 any later version.
  11
  12 GNU CC is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GNU CC; see the file COPYING.  If not, write to
  19 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
  20
  21 #define __CHILL_LIB__
  22
  23 #include "config.h"
  24 #include <stdio.h>
  25 #include "powerset.h"
  26
  27 extern void __cause_ex1 (char *exname, char *file, int lineno);
  28
  29 /*
  30  * function __inbitstring
  31  *
  32  * parameters:
  33  *      bitno           bit number within set
  34  *      powerset        the powerset
  35  *      bitlength       length of powerset in bits
  36  *      minval          number of lowest bit stored
  37  *      fname           filename of caller
  38  *      lineno          linenumber of caller
  39  *
  40  * returns:
  41  *      int             1 .. found
  42  *                      0 .. not found
  43  *
  44  * exceptions:
  45  *  rangefail
  46  *
  47  * abstract:
  48  *  checks if a given value is included in a bitstring
  49  *
  50  */
  51 int
  52 __inbitstring (bitno, powerset, bitlength, minval, fname, lineno)
  53      unsigned long  bitno;
  54      SET_WORD      *powerset;
  55      unsigned long  bitlength;
  56      long           minval;
  57      char          *fname;
  58      int            lineno;
  59
  60 {
  61   if (powerset == NULL
  62       || bitno < minval
  63       || (bitno - minval) >= bitlength)
  64     __cause_ex1 ("rangefail", fname, lineno);
  65
  66   bitno -= minval;
  67   if (bitlength <= SET_CHAR_SIZE)
  68     return GET_BIT_IN_CHAR (*((SET_CHAR *)powerset), bitno);
  69   else if (bitlength <= SET_SHORT_SIZE)
  70     return GET_BIT_IN_SHORT (*((SET_SHORT *)powerset), bitno);
  71   else
  72     return GET_BIT_IN_WORD (powerset[bitno / SET_WORD_SIZE],
  73                             bitno % SET_WORD_SIZE);
  74 }