/* 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 __setbitpowerset
 *
 * parameters:
 *	set		destination set
 *	bitlength	length of powerset in bits
 *      minval          lowest valid set value
 *      bitno           bit number within set
 *      new_value       zero or one - (new bit value)
 *
 * returns:
 *	int		1 .. found
 *			0 .. not found
 *
 * exceptions:
 *  rangefail
 *
 * abstract:
 *  checks if a given value is included in a powerset
 *
 */
void
__setbitpowerset (powerset, bitlength, minval, bitno, new_value, filename, lineno)
     SET_WORD      *powerset;
     unsigned long  bitlength;
     long           minval;
     long	    bitno;
     char	    new_value; /* booleans are represented as 8 bit value */
     char *	    filename;
     int	    lineno;
{
  if (powerset == NULL
      || bitno < minval 
      || (bitno - minval) >= bitlength)
    __cause_ex1 ("rangefail", filename, lineno);

  bitno -= minval;
  if (bitlength <= SET_CHAR_SIZE)
    {
      if (new_value & 1)
	SET_BIT_IN_CHAR (*((SET_CHAR *)powerset), bitno);
      else
	CLEAR_BIT_IN_CHAR (*((SET_CHAR *)powerset), bitno);
    }
  else if (bitlength <= SET_SHORT_SIZE)
    {
      if (new_value & 1)
	SET_BIT_IN_SHORT (*((SET_SHORT *)powerset), bitno);
      else
	CLEAR_BIT_IN_SHORT (*((SET_SHORT *)powerset), bitno);
    }
  else
    {
      powerset += (bitno/SET_WORD_SIZE);
      bitno %= SET_WORD_SIZE;
      if (new_value & 1)
	SET_BIT_IN_WORD (*powerset, bitno);
      else
	CLEAR_BIT_IN_WORD (*powerset, bitno);
    }
}