/* Implement POWERSET runtime actions for CHILL.
   Copyright (C) 1992,1993 Free Software Foundation, Inc.
   Author: Wilfried Moser, et al

This file is part of GNU CC.

GNU CC is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.

GNU CC is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU CC; see the file COPYING.  If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */

#define __CHILL_LIB__

#include <stdio.h>
#include "powerset.h"

extern void __cause_ex1 (char *exname, char *file, int lineno);

/*
 * function __inbitstring
 *
 * parameters:
 *	bitno		bit number within set
 *	powerset	the powerset
 *	bitlength	length of powerset in bits
 *      minval          number of lowest bit stored
 *	fname		filename of caller
 *	lineno		linenumber of caller
 *
 * returns:
 *	int		1 .. found
 *			0 .. not found
 *
 * exceptions:
 *  rangefail
 *
 * abstract:
 *  checks if a given value is included in a bitstring
 *
 */
int
__inbitstring (bitno, powerset, bitlength, minval, fname, lineno)
     unsigned long  bitno;
     SET_WORD      *powerset;
     unsigned long  bitlength;
     long           minval;
     char          *fname;
     int            lineno;
    
{
  if (powerset == NULL
      || bitno < minval 
      || (bitno - minval) >= bitlength)
    __cause_ex1 ("rangefail", fname, lineno);

  bitno -= minval;
  if (bitlength <= SET_CHAR_SIZE)
    return GET_BIT_IN_CHAR (*((SET_CHAR *)powerset), bitno);
  else if (bitlength <= SET_SHORT_SIZE)
    return GET_BIT_IN_SHORT (*((SET_SHORT *)powerset), bitno);
  else
    return GET_BIT_IN_WORD (powerset[bitno / SET_WORD_SIZE],
			    bitno % SET_WORD_SIZE);
}