/* Chains of recurrences.
   Copyright (C) 2003-2018 Free Software Foundation, Inc.
   Contributed by Sebastian Pop <pop@cri.ensmp.fr>

This file is part of GCC.

GCC 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 3, or (at your option) any later
version.

GCC 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 GCC; see the file COPYING3.  If not see
<http://www.gnu.org/licenses/>.  */

#ifndef GCC_TREE_CHREC_H
#define GCC_TREE_CHREC_H

/* The following trees are unique elements.  Thus the comparison of another
   element to these elements should be done on the pointer to these trees,
   and not on their value.  */

extern tree chrec_not_analyzed_yet;
extern GTY(()) tree chrec_dont_know;
extern GTY(()) tree chrec_known;

/* After having added an automatically generated element, please
   include it in the following function.  */

static inline bool
automatically_generated_chrec_p (const_tree chrec)
{
  return (chrec == chrec_dont_know
	  || chrec == chrec_known);
}

/* The tree nodes aka. CHRECs.  */

static inline bool
tree_is_chrec (const_tree expr)
{
  if (TREE_CODE (expr) == POLYNOMIAL_CHREC
      || automatically_generated_chrec_p (expr))
    return true;
  else
    return false;
}