libchill/inps.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, 59 Temple Place - Suite 330,
  20 Boston, MA 02111-1307, USA.  */
  21
  22 /* As a special exception, if you link this library with other files,
  23    some of which are compiled with GCC, to produce an executable,
  24    this library does not by itself cause the resulting executable
  25    to be covered by the GNU General Public License.
  26    This exception does not however invalidate any other reasons why
  27    the executable file might be covered by the GNU General Public License.  */
  28
  29 #define __CHILL_LIB__
  30
  31 #include <stdio.h>
  32 #include "powerset.h"
  33
  34 /*
  35  * function __inpowerset
  36  *
  37  * parameters:
  38  *      bitno           bit number within set
  39  *      powerset        the powerset
  40  *      bitlength       length of powerset in bits
  41  *      minval          number of lowest bit stored
  42  *
  43  * returns:
  44  *      int             1 .. found
  45  *                      0 .. not found
  46  *
  47  * exceptions:
  48  *  rangefail
  49  *
  50  * abstract:
  51  *  checks if a given value is included in a powerset
  52  *
  53  */
  54 int
  55 __inpowerset (bitno, powerset, bitlength, minval)
  56      unsigned long  bitno;
  57      SET_WORD      *powerset;
  58      unsigned long  bitlength;
  59      long           minval;
  60 {
  61   if (bitno < minval || (bitno - minval) >= bitlength)
  62     return 0;
  63
  64   bitno -= minval;
  65   if (bitlength <= SET_CHAR_SIZE)
  66     return GET_BIT_IN_CHAR (*((SET_CHAR *)powerset), bitno);
  67   else if (bitlength <= SET_SHORT_SIZE)
  68     return GET_BIT_IN_SHORT (*((SET_SHORT *)powerset), bitno);
  69   else
  70     return GET_BIT_IN_WORD (powerset[bitno / SET_WORD_SIZE],
  71                             bitno % SET_WORD_SIZE);
  72 }