/* Implement powerset-related runtime actions for CHILL.
   Copyright (C) 1992, 93, 1994 Free Software Foundation, Inc.
   Author: Bill Cox

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 "powerset.h"

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

/*
 * function __concatps
 *
 * parameters:
 *     OUT      - pointer to output PS
 *     LEFT     - pointer to left PS
 *     LEFTLEN  - length of left PS in bits
 *     RIGHT    - pointer to right PS
 *     RIGHTLEN - length of right PS in bits
 *
 * returns:
 *     void
 *
 * exceptions:
 *     none
 *
 * abstract:
 *     concatenates two powersets into the output powerset.
 *
 */

extern void
__pscpy (SET_WORD      *dps,
	 unsigned long  dbl,
	 unsigned long  doffset,
	 SET_WORD      *sps,
	 unsigned long  sbl,
	 unsigned long  start,
	 unsigned long  length);

void
__concatps (out, left, leftlen, right, rightlen)
     SET_WORD      *out;
     SET_WORD      *left;
     unsigned long  leftlen;
     SET_WORD      *right;
     unsigned long  rightlen;
{
  /* allocated sizes for each set involved */
  unsigned long outall, leftall, rightall;

  if (!out)
    {
      /* FIXME: cause an exception */
    }
  else if (leftlen == 0 || !left)
    {
      if (rightlen == 0 || !right)
	return;               /* no work to do */
      __pscpy (out, rightlen, (unsigned long)0,
	       right, rightlen, (unsigned long)0, rightlen);
    }
  else if (rightlen == 0 || !right)
    {
      if (leftlen == 0 || !left)
	return;               /* no work to do */
      __pscpy (out, leftlen, (unsigned long)0,
	       left, leftlen, (unsigned long)0, leftlen);
    }
  /* copy the left powerset into bits 0..leftlen - 1 */
  __pscpy (out, leftlen + rightlen, (unsigned long)0,
	   left, leftlen, (unsigned long)0, leftlen);

  /* copy the right powerset into bits leftlen..leftlen+rightlen-1 */
  __pscpy (out, leftlen + rightlen, leftlen,
	   right, rightlen, (unsigned long)0, rightlen);
}