/* 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 "config.h"
#include <stdio.h>
#include "powerset.h"

/*
 * function __eqpowerset
 *
 * parameters:
 *	left		left powerset
 *	right		right powerset
 *	bitlength	length of powerset in bits
 *
 * returns:
 *    1 if powersets are equal, bit for bit
 *
 * exceptions:
 *  none
 *
 * abstract:
 *  compares two powersets for equality
 *
 */
int
__eqpowerset (left, right, bitlength)
     SET_WORD *left;
     SET_WORD *right;
     unsigned long bitlength;
{
#ifndef USE_CHARS
  if (bitlength <= SET_CHAR_SIZE)
    {
      SET_CHAR c = *(SET_CHAR *)left ^ *(SET_CHAR *)right;
      MASK_UNUSED_CHAR_BITS (&c, bitlength);
      return (c == 0) ? 1 : 0;
    }
  else if (bitlength <= SET_SHORT_SIZE)
    {
      SET_SHORT c = *(SET_SHORT *)left ^ *(SET_SHORT *)right;
      MASK_UNUSED_SHORT_BITS (&c, bitlength);
      return (c == 0) ? 1 : 0;
    }
  else if (bitlength <= SET_WORD_SIZE)
    {
      SET_WORD c = *(SET_WORD *)left ^ *(SET_WORD *)right;
      MASK_UNUSED_WORD_BITS (&c, bitlength % SET_WORD_SIZE);
      return (c == 0) ? 1 : 0;
    }
  else
#endif
    {
      SET_WORD c;
      register unsigned long i;
      unsigned long len = bitlength / SET_WORD_SIZE;

      for (i = 0; i < len; i++) /* a word-oriented memcmp */
	if (left[i] != right[i])
	  return 0;
      /* do the last (possibly partial) word */
      bitlength %= SET_WORD_SIZE;
      if (bitlength == 0)
	return 1;
      c = left[i] ^ right[i];
      MASK_UNUSED_WORD_BITS (&c, bitlength);
      return (c == 0) ? 1 : 0;
    }
}
