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/* 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;
}
enum ev_direction {EV_DIR_GROWS, EV_DIR_DECREASES, EV_DIR_UNKNOWN};
enum ev_direction scev_direction (const_tree);
/* 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, gimple *, bool = true, tree = NULL);
extern tree chrec_convert_rhs (tree, tree, gimple *);
extern tree chrec_convert_aggressive (tree, tree, bool *);
/* Operations. */
extern tree chrec_apply (unsigned, tree, tree);
extern tree chrec_apply_map (tree, vec<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);
extern void for_each_scev_op (tree *, bool (*) (tree *, void *), void *);
extern bool convert_affine_scev (struct loop *, tree, tree *, tree *, gimple *,
bool, tree = NULL);
/* Observers. */
extern bool eq_evolutions_p (const_tree, const_tree);
extern bool is_multivariate_chrec (const_tree);
extern bool chrec_contains_symbols (const_tree);
extern bool chrec_contains_symbols_defined_in_loop (const_tree, unsigned);
extern bool chrec_contains_undetermined (const_tree);
extern bool tree_contains_chrecs (const_tree, int *);
extern bool evolution_function_is_affine_multivariate_p (const_tree, int);
extern bool evolution_function_is_univariate_p (const_tree);
extern unsigned nb_vars_in_chrec (tree);
extern bool evolution_function_is_invariant_p (tree, int);
extern bool scev_is_linear_expression (tree);
extern bool evolution_function_right_is_integer_cst (const_tree);
/* Determines whether CHREC is equal to zero. */
static inline bool
chrec_zerop (const_tree chrec)
{
if (chrec == NULL_TREE)
return false;
if (TREE_CODE (chrec) == INTEGER_CST)
return integer_zerop (chrec);
return false;
}
/* 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;
STRIP_NOPS (chrec);
scev = hide_evolution_in_other_loops_than_loop (chrec, loop_num);
*res = !tree_contains_chrecs (scev, NULL);
return true;
}
/* Build a polynomial chain of recurrence. */
static inline tree
build_polynomial_chrec (unsigned loop_num,
tree left,
tree right)
{
bool val;
if (left == chrec_dont_know
|| right == chrec_dont_know)
return chrec_dont_know;
if (!no_evolution_in_loop_p (left, loop_num, &val)
|| !val)
return chrec_dont_know;
/* Types of left and right sides of a chrec should be compatible, but
pointer CHRECs are special in that the evolution is of ptroff type. */
if (POINTER_TYPE_P (TREE_TYPE (left)))
gcc_checking_assert (ptrofftype_p (TREE_TYPE (right)));
else
{
/* Pointer types should occur only on the left hand side, i.e. in
the base of the chrec, and not in the step. */
gcc_checking_assert (!POINTER_TYPE_P (TREE_TYPE (right))
&& types_compatible_p (TREE_TYPE (left),
TREE_TYPE (right)));
}
if (chrec_zerop (right))
return left;
tree chrec = build2 (POLYNOMIAL_CHREC, TREE_TYPE (left), left, right);
CHREC_VARIABLE (chrec) = loop_num;
return chrec;
}
/* Determines whether the expression CHREC is a constant. */
static inline bool
evolution_function_is_constant_p (const_tree chrec)
{
if (chrec == NULL_TREE)
return false;
if (CONSTANT_CLASS_P (chrec))
return true;
return is_gimple_min_invariant (chrec);
}
/* Determine whether CHREC is an affine evolution function in LOOPNUM. */
static inline bool
evolution_function_is_affine_in_loop (const_tree chrec, int loopnum)
{
if (chrec == NULL_TREE)
return false;
switch (TREE_CODE (chrec))
{
case POLYNOMIAL_CHREC:
if (evolution_function_is_invariant_p (CHREC_LEFT (chrec), loopnum)
&& evolution_function_is_invariant_p (CHREC_RIGHT (chrec), loopnum))
return true;
else
return false;
default:
return false;
}
}
/* Determine whether CHREC is an affine evolution function or not. */
static inline bool
evolution_function_is_affine_p (const_tree chrec)
{
return chrec
&& TREE_CODE (chrec) == POLYNOMIAL_CHREC
&& evolution_function_is_invariant_p (CHREC_RIGHT (chrec),
CHREC_VARIABLE (chrec))
&& (TREE_CODE (CHREC_RIGHT (chrec)) != POLYNOMIAL_CHREC
|| evolution_function_is_affine_p (CHREC_RIGHT (chrec)));
}
/* Determines whether EXPR does not contains chrec expressions. */
static inline bool
tree_does_not_contain_chrecs (const_tree expr)
{
return !tree_contains_chrecs (expr, NULL);
}
/* Returns the type of the chrec. */
static inline tree
chrec_type (const_tree chrec)
{
if (automatically_generated_chrec_p (chrec))
return NULL_TREE;
return TREE_TYPE (chrec);
}
static inline tree
chrec_fold_op (enum tree_code code, tree type, tree op0, tree op1)
{
switch (code)
{
case PLUS_EXPR:
return chrec_fold_plus (type, op0, op1);
case MINUS_EXPR:
return chrec_fold_minus (type, op0, op1);
case MULT_EXPR:
return chrec_fold_multiply (type, op0, op1);
default:
gcc_unreachable ();
}
}
#endif /* GCC_TREE_CHREC_H */