/* Scalar evolution detector.
   Copyright (C) 2003, 2004, 2005, 2007, 2008 Free Software Foundation, Inc.
   Contributed by Sebastian Pop <s.pop@laposte.net>

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_SCALAR_EVOLUTION_H
#define GCC_TREE_SCALAR_EVOLUTION_H

extern tree number_of_latch_executions (struct loop *);
extern tree number_of_exit_cond_executions (struct loop *);
extern gimple get_loop_exit_condition (const struct loop *);

extern void scev_initialize (void);
extern void scev_reset (void);
extern void scev_finalize (void);
extern tree analyze_scalar_evolution (struct loop *, tree);
extern tree instantiate_scev (basic_block, struct loop *, tree);
extern tree resolve_mixers (struct loop *, tree);
extern void gather_stats_on_scev_database (void);
extern void scev_analysis (void);
unsigned int scev_const_prop (void);

bool expression_expensive_p (tree);
extern bool simple_iv (struct loop *, struct loop *, tree, affine_iv *, bool);

/* Returns the basic block preceding LOOP or ENTRY_BLOCK_PTR when the
   loop is function's body.  */

static inline basic_block
block_before_loop (loop_p loop)
{
  edge preheader = loop_preheader_edge (loop);
  return (preheader ? preheader->src : ENTRY_BLOCK_PTR);
}

/* Analyze all the parameters of the chrec that were left under a
   symbolic form.  LOOP is the loop in which symbolic names have to
   be analyzed and instantiated.  */

static inline tree
instantiate_parameters (struct loop *loop, tree chrec)
{
  return instantiate_scev (block_before_loop (loop), loop, chrec);
}

/* Returns the loop of the polynomial chrec CHREC.  */

static inline struct loop *
get_chrec_loop (const_tree chrec)
{
  return get_loop (CHREC_VARIABLE (chrec));
}

#endif  /* GCC_TREE_SCALAR_EVOLUTION_H  */