1 /* Chains of recurrences.
2 Copyright (C) 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
3 Contributed by Sebastian Pop <pop@cri.ensmp.fr>
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
22 #ifndef GCC_TREE_CHREC_H
23 #define GCC_TREE_CHREC_H
25 /* The following trees are unique elements. Thus the comparison of another
26 element to these elements should be done on the pointer to these trees,
27 and not on their value. */
29 extern tree chrec_not_analyzed_yet;
30 extern GTY(()) tree chrec_dont_know;
31 extern GTY(()) tree chrec_known;
33 /* After having added an automatically generated element, please
34 include it in the following function. */
37 automatically_generated_chrec_p (tree chrec)
39 return (chrec == chrec_dont_know
40 || chrec == chrec_known);
43 /* The tree nodes aka. CHRECs. */
46 tree_is_chrec (tree expr)
48 if (TREE_CODE (expr) == POLYNOMIAL_CHREC
49 || automatically_generated_chrec_p (expr))
57 /* Chrec folding functions. */
58 extern tree chrec_fold_plus (tree, tree, tree);
59 extern tree chrec_fold_minus (tree, tree, tree);
60 extern tree chrec_fold_multiply (tree, tree, tree);
61 extern tree chrec_convert (tree, tree, tree);
62 extern tree chrec_convert_rhs (tree, tree, tree);
63 extern tree chrec_convert_aggressive (tree, tree);
66 extern tree chrec_apply (unsigned, tree, tree);
67 extern tree chrec_replace_initial_condition (tree, tree);
68 extern tree initial_condition (tree);
69 extern tree initial_condition_in_loop_num (tree, unsigned);
70 extern tree evolution_part_in_loop_num (tree, unsigned);
71 extern tree hide_evolution_in_other_loops_than_loop (tree, unsigned);
72 extern tree reset_evolution_in_loop (unsigned, tree, tree);
73 extern tree chrec_merge (tree, tree);
76 extern bool eq_evolutions_p (tree, tree);
77 extern bool is_multivariate_chrec (tree);
78 extern bool chrec_is_positive (tree, bool *);
79 extern bool chrec_contains_symbols (tree);
80 extern bool chrec_contains_symbols_defined_in_loop (tree, unsigned);
81 extern bool chrec_contains_undetermined (tree);
82 extern bool tree_contains_chrecs (tree, int *);
83 extern bool evolution_function_is_affine_multivariate_p (tree, int);
84 extern bool evolution_function_is_univariate_p (tree);
85 extern unsigned nb_vars_in_chrec (tree);
86 extern bool evolution_function_is_invariant_p (tree, int);
88 /* Determines whether CHREC is equal to zero. */
91 chrec_zerop (tree chrec)
93 if (chrec == NULL_TREE)
96 if (TREE_CODE (chrec) == INTEGER_CST)
97 return integer_zerop (chrec);
102 /* Determines whether CHREC is a loop invariant with respect to LOOP_NUM.
103 Set the result in RES and return true when the property can be computed. */
106 no_evolution_in_loop_p (tree chrec, unsigned loop_num, bool *res)
110 if (chrec == chrec_not_analyzed_yet
111 || chrec == chrec_dont_know
112 || chrec_contains_symbols_defined_in_loop (chrec, loop_num))
115 scev = hide_evolution_in_other_loops_than_loop (chrec, loop_num);
116 *res = !tree_is_chrec (scev);
120 /* Build a polynomial chain of recurrence. */
123 build_polynomial_chrec (unsigned loop_num,
129 if (left == chrec_dont_know
130 || right == chrec_dont_know)
131 return chrec_dont_know;
133 if (no_evolution_in_loop_p (left, loop_num, &val) && !val)
134 return chrec_dont_know;
136 if (POINTER_TYPE_P (TREE_TYPE (left)))
137 gcc_assert (sizetype == TREE_TYPE (right));
139 gcc_assert (TREE_TYPE (left) == TREE_TYPE (right));
141 if (chrec_zerop (right))
144 return build3 (POLYNOMIAL_CHREC, TREE_TYPE (left),
145 build_int_cst (NULL_TREE, loop_num), left, right);
148 /* Determines whether the expression CHREC is a constant. */
151 evolution_function_is_constant_p (tree chrec)
153 if (chrec == NULL_TREE)
156 switch (TREE_CODE (chrec))
167 /* Determine whether the given tree is an affine evolution function or not. */
170 evolution_function_is_affine_p (tree chrec)
172 if (chrec == NULL_TREE)
175 switch (TREE_CODE (chrec))
177 case POLYNOMIAL_CHREC:
178 if (evolution_function_is_invariant_p (CHREC_LEFT (chrec),
179 CHREC_VARIABLE (chrec))
180 && evolution_function_is_invariant_p (CHREC_RIGHT (chrec),
181 CHREC_VARIABLE (chrec)))
191 /* Determine whether the given tree is an affine or constant evolution
195 evolution_function_is_affine_or_constant_p (tree chrec)
197 return evolution_function_is_affine_p (chrec)
198 || evolution_function_is_constant_p (chrec);
201 /* Determines whether EXPR does not contains chrec expressions. */
204 tree_does_not_contain_chrecs (tree expr)
206 return !tree_contains_chrecs (expr, NULL);
209 /* Returns the type of the chrec. */
212 chrec_type (tree chrec)
214 if (automatically_generated_chrec_p (chrec))
217 return TREE_TYPE (chrec);
221 #endif /* GCC_TREE_CHREC_H */