1 /* Chains of recurrences.
2 Copyright (C) 2003, 2004, 2005, 2006, 2007 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 3, 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 COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
21 #ifndef GCC_TREE_CHREC_H
22 #define GCC_TREE_CHREC_H
24 /* The following trees are unique elements. Thus the comparison of another
25 element to these elements should be done on the pointer to these trees,
26 and not on their value. */
28 extern tree chrec_not_analyzed_yet;
29 extern GTY(()) tree chrec_dont_know;
30 extern GTY(()) tree chrec_known;
32 /* After having added an automatically generated element, please
33 include it in the following function. */
36 automatically_generated_chrec_p (const_tree chrec)
38 return (chrec == chrec_dont_know
39 || chrec == chrec_known);
42 /* The tree nodes aka. CHRECs. */
45 tree_is_chrec (const_tree expr)
47 if (TREE_CODE (expr) == POLYNOMIAL_CHREC
48 || automatically_generated_chrec_p (expr))
56 /* Chrec folding functions. */
57 extern tree chrec_fold_plus (tree, tree, tree);
58 extern tree chrec_fold_minus (tree, tree, tree);
59 extern tree chrec_fold_multiply (tree, tree, tree);
60 extern tree chrec_convert (tree, tree, gimple);
61 extern tree chrec_convert_rhs (tree, tree, gimple);
62 extern tree chrec_convert_aggressive (tree, tree);
65 extern tree chrec_apply (unsigned, tree, tree);
66 extern tree chrec_replace_initial_condition (tree, tree);
67 extern tree initial_condition (tree);
68 extern tree initial_condition_in_loop_num (tree, unsigned);
69 extern tree evolution_part_in_loop_num (tree, unsigned);
70 extern tree hide_evolution_in_other_loops_than_loop (tree, unsigned);
71 extern tree reset_evolution_in_loop (unsigned, tree, tree);
72 extern tree chrec_merge (tree, tree);
73 extern void for_each_scev_op (tree *, bool (*) (tree *, void *), void *);
76 extern bool eq_evolutions_p (const_tree, const_tree);
77 extern bool is_multivariate_chrec (const_tree);
78 extern bool chrec_is_positive (tree, bool *);
79 extern bool chrec_contains_symbols (const_tree);
80 extern bool chrec_contains_symbols_defined_in_loop (const_tree, unsigned);
81 extern bool chrec_contains_undetermined (const_tree);
82 extern bool tree_contains_chrecs (const_tree, int *);
83 extern bool evolution_function_is_affine_multivariate_p (const_tree, int);
84 extern bool evolution_function_is_univariate_p (const_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 (const_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 /* Pointer types should occur only on the left hand side, i.e. in
137 the base of the chrec, and not in the step. */
138 gcc_assert (!POINTER_TYPE_P (TREE_TYPE (right)));
140 /* Types of left and right sides of a chrec should be compatible. */
141 if (POINTER_TYPE_P (TREE_TYPE (left)))
142 gcc_assert (sizetype == TREE_TYPE (right));
144 gcc_assert (TREE_TYPE (left) == TREE_TYPE (right));
146 if (chrec_zerop (right))
149 return build3 (POLYNOMIAL_CHREC, TREE_TYPE (left),
150 build_int_cst (NULL_TREE, loop_num), left, right);
153 /* Determines whether the expression CHREC is a constant. */
156 evolution_function_is_constant_p (const_tree chrec)
158 if (chrec == NULL_TREE)
161 switch (TREE_CODE (chrec))
172 /* Determine whether CHREC is an affine evolution function in LOOPNUM. */
175 evolution_function_is_affine_in_loop (const_tree chrec, int loopnum)
177 if (chrec == NULL_TREE)
180 switch (TREE_CODE (chrec))
182 case POLYNOMIAL_CHREC:
183 if (evolution_function_is_invariant_p (CHREC_LEFT (chrec), loopnum)
184 && evolution_function_is_invariant_p (CHREC_RIGHT (chrec), loopnum))
194 /* Determine whether CHREC is an affine evolution function or not. */
197 evolution_function_is_affine_p (const_tree chrec)
199 if (chrec == NULL_TREE)
202 switch (TREE_CODE (chrec))
204 case POLYNOMIAL_CHREC:
205 if (evolution_function_is_invariant_p (CHREC_LEFT (chrec),
206 CHREC_VARIABLE (chrec))
207 && evolution_function_is_invariant_p (CHREC_RIGHT (chrec),
208 CHREC_VARIABLE (chrec)))
218 /* Determines whether EXPR does not contains chrec expressions. */
221 tree_does_not_contain_chrecs (const_tree expr)
223 return !tree_contains_chrecs (expr, NULL);
226 /* Returns the type of the chrec. */
229 chrec_type (const_tree chrec)
231 if (automatically_generated_chrec_p (chrec))
234 return TREE_TYPE (chrec);
238 chrec_fold_op (enum tree_code code, tree type, tree op0, tree op1)
243 return chrec_fold_plus (type, op0, op1);
246 return chrec_fold_minus (type, op0, op1);
249 return chrec_fold_multiply (type, op0, op1);
257 #endif /* GCC_TREE_CHREC_H */