/* Chains of recurrences.
Copyright (C) 2003, 2004, 2005, 2006 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 2, 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 COPYING. If not, write to the Free
Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301, USA. */
#ifndef GCC_TREE_CHREC_H
#define GCC_TREE_CHREC_H
/* Accessors for the chains of recurrences. */
#define CHREC_VAR(NODE) TREE_OPERAND (NODE, 0)
#define CHREC_LEFT(NODE) TREE_OPERAND (NODE, 1)
#define CHREC_RIGHT(NODE) TREE_OPERAND (NODE, 2)
#define CHREC_VARIABLE(NODE) TREE_INT_CST_LOW (CHREC_VAR (NODE))
/* 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 (tree chrec)
{
return (chrec == chrec_not_analyzed_yet
|| chrec == chrec_dont_know
|| chrec == chrec_known);
}
/* The tree nodes aka. CHRECs. */
static inline bool
tree_is_chrec (tree expr)
{
if (TREE_CODE (expr) == POLYNOMIAL_CHREC
|| automatically_generated_chrec_p (expr))
return true;
else
return false;
}
/* Chrec folding functions. */
extern tree chrec_fold_plus (tree, tree, tree);
extern tree chrec_fold_minus (tree, tree, tree);
extern tree chrec_fold_multiply (tree, tree, tree);
extern tree chrec_convert (tree, tree, tree);
extern tree chrec_convert_aggressive (tree, tree);
/* Operations. */
extern tree chrec_apply (unsigned, tree, tree);
extern tree chrec_replace_initial_condition (tree, tree);
extern tree initial_condition (tree);
extern tree initial_condition_in_loop_num (tree, unsigned);
extern tree evolution_part_in_loop_num (tree, unsigned);
extern tree hide_evolution_in_other_loops_than_loop (tree, unsigned);
extern tree reset_evolution_in_loop (unsigned, tree, tree);
extern tree chrec_merge (tree, tree);
/* Observers. */
extern bool eq_evolutions_p (tree, tree);
extern bool is_multivariate_chrec (tree);
extern bool chrec_is_positive (tree, bool *);
extern bool chrec_contains_symbols (tree);
extern bool chrec_contains_symbols_defined_in_loop (tree, unsigned);
extern bool chrec_contains_undetermined (tree);
extern bool tree_contains_chrecs (tree, int *);
extern bool evolution_function_is_affine_multivariate_p (tree);
extern bool evolution_function_is_univariate_p (tree);
extern unsigned nb_vars_in_chrec (tree);
/* Build a polynomial chain of recurrence. */
static inline tree
build_polynomial_chrec (unsigned loop_num,
tree left,
tree right)
{
if (left == chrec_dont_know
|| right == chrec_dont_know)
return chrec_dont_know;
gcc_assert (TREE_TYPE (left) == TREE_TYPE (right));
return build3 (POLYNOMIAL_CHREC, TREE_TYPE (left),
build_int_cst (NULL_TREE, loop_num), left, right);
}
/* Observers. */
/* Determines whether CHREC is equal to zero. */
static inline bool
chrec_zerop (tree chrec)
{
if (chrec == NULL_TREE)
return false;
if (TREE_CODE (chrec) == INTEGER_CST)
return integer_zerop (chrec);
return false;
}
/* Determines whether the expression CHREC is a constant. */
static inline bool
evolution_function_is_constant_p (tree chrec)
{
if (chrec == NULL_TREE)
return false;
switch (TREE_CODE (chrec))
{
case INTEGER_CST:
case REAL_CST:
return true;
default:
return false;
}
}
extern bool evolution_function_is_invariant_p (tree, int);
/* Determine whether the given tree is an affine evolution function or not. */
static inline bool
evolution_function_is_affine_p (tree chrec)
{
if (chrec == NULL_TREE)
return false;
switch (TREE_CODE (chrec))
{
case POLYNOMIAL_CHREC:
if (evolution_function_is_invariant_p (CHREC_LEFT (chrec),
CHREC_VARIABLE (chrec))
&& evolution_function_is_invariant_p (CHREC_RIGHT (chrec),
CHREC_VARIABLE (chrec)))
return true;
else
return false;
default:
return false;
}
}
/* Determine whether the given tree is an affine or constant evolution
function. */
static inline bool
evolution_function_is_affine_or_constant_p (tree chrec)
{
return evolution_function_is_affine_p (chrec)
|| evolution_function_is_constant_p (chrec);
}
/* Determines whether EXPR does not contains chrec expressions. */
static inline bool
tree_does_not_contain_chrecs (tree expr)
{
return !tree_contains_chrecs (expr, NULL);
}
/* Determines whether CHREC is a loop invariant with respect to LOOP_NUM.
Set the result in RES and return true when the property can be computed. */
static inline bool
no_evolution_in_loop_p (tree chrec, unsigned loop_num, bool *res)
{
tree scev;
if (chrec == chrec_not_analyzed_yet
|| chrec == chrec_dont_know
|| chrec_contains_symbols_defined_in_loop (chrec, loop_num))
return false;
scev = hide_evolution_in_other_loops_than_loop (chrec, loop_num);
*res = !tree_is_chrec (scev);
return true;
}
/* Returns the type of the chrec. */
static inline tree
chrec_type (tree chrec)
{
if (automatically_generated_chrec_p (chrec))
return NULL_TREE;
return TREE_TYPE (chrec);
}
#endif /* GCC_TREE_CHREC_H */
