1 | /* Chains of recurrences. |
2 | Copyright (C) 2003-2023 Free Software Foundation, Inc. |
3 | Contributed by Sebastian Pop <pop@cri.ensmp.fr> |
4 | |
5 | This file is part of GCC. |
6 | |
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 |
10 | version. |
11 | |
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 |
15 | for more details. |
16 | |
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/>. */ |
20 | |
21 | #ifndef GCC_TREE_CHREC_H |
22 | #define GCC_TREE_CHREC_H |
23 | |
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. |
27 | |
28 | extern tree chrec_not_analyzed_yet; |
29 | extern tree chrec_dont_know; |
30 | extern tree chrec_known; |
31 | |
32 | chrec_not_analyzed_yet is NULL_TREE and the others are defined |
33 | in global_trees[]. */ |
34 | |
35 | /* After having added an automatically generated element, please |
36 | include it in the following function. */ |
37 | |
38 | inline bool |
39 | automatically_generated_chrec_p (const_tree chrec) |
40 | { |
41 | return (chrec == chrec_dont_know |
42 | || chrec == chrec_known); |
43 | } |
44 | |
45 | /* The tree nodes aka. CHRECs. */ |
46 | |
47 | inline bool |
48 | tree_is_chrec (const_tree expr) |
49 | { |
50 | if (TREE_CODE (expr) == POLYNOMIAL_CHREC |
51 | || automatically_generated_chrec_p (chrec: expr)) |
52 | return true; |
53 | else |
54 | return false; |
55 | } |
56 | |
57 | |
58 | enum ev_direction {EV_DIR_GROWS, EV_DIR_DECREASES, EV_DIR_UNKNOWN}; |
59 | enum ev_direction scev_direction (const_tree); |
60 | |
61 | /* Chrec folding functions. */ |
62 | extern tree chrec_fold_plus (tree, tree, tree); |
63 | extern tree chrec_fold_minus (tree, tree, tree); |
64 | extern tree chrec_fold_multiply (tree, tree, tree); |
65 | extern tree chrec_convert (tree, tree, gimple *, bool = true, tree = NULL); |
66 | extern tree chrec_convert_rhs (tree, tree, gimple *); |
67 | extern tree chrec_convert_aggressive (tree, tree, bool *); |
68 | |
69 | /* Operations. */ |
70 | extern tree chrec_apply (unsigned, tree, tree); |
71 | extern tree chrec_apply_map (tree, vec<tree> ); |
72 | extern tree chrec_replace_initial_condition (tree, tree); |
73 | extern tree initial_condition (tree); |
74 | extern tree initial_condition_in_loop_num (tree, unsigned); |
75 | extern tree evolution_part_in_loop_num (tree, unsigned); |
76 | extern tree hide_evolution_in_other_loops_than_loop (tree, unsigned); |
77 | extern tree reset_evolution_in_loop (unsigned, tree, tree); |
78 | extern tree chrec_merge (tree, tree); |
79 | extern void for_each_scev_op (tree *, bool (*) (tree *, void *), void *); |
80 | extern bool convert_affine_scev (class loop *, tree, tree *, tree *, gimple *, |
81 | bool, tree = NULL); |
82 | |
83 | /* Observers. */ |
84 | extern bool eq_evolutions_p (const_tree, const_tree); |
85 | extern bool is_multivariate_chrec (const_tree); |
86 | extern bool chrec_contains_symbols (const_tree, class loop * = NULL); |
87 | extern bool chrec_contains_symbols_defined_in_loop (const_tree, unsigned); |
88 | extern bool chrec_contains_undetermined (const_tree); |
89 | extern bool tree_contains_chrecs (const_tree, int *); |
90 | extern bool evolution_function_is_affine_multivariate_p (const_tree, int); |
91 | extern bool evolution_function_is_univariate_p (const_tree, int = 0); |
92 | extern unsigned nb_vars_in_chrec (tree); |
93 | extern bool evolution_function_is_invariant_p (tree, int); |
94 | extern bool scev_is_linear_expression (tree); |
95 | extern bool evolution_function_right_is_integer_cst (const_tree); |
96 | |
97 | /* Determines whether CHREC is equal to zero. */ |
98 | |
99 | inline bool |
100 | chrec_zerop (const_tree chrec) |
101 | { |
102 | if (chrec == NULL_TREE) |
103 | return false; |
104 | |
105 | if (TREE_CODE (chrec) == INTEGER_CST) |
106 | return integer_zerop (chrec); |
107 | |
108 | return false; |
109 | } |
110 | |
111 | /* Determines whether CHREC is a loop invariant with respect to LOOP_NUM. |
112 | Set the result in RES and return true when the property can be computed. */ |
113 | |
114 | inline bool |
115 | no_evolution_in_loop_p (tree chrec, unsigned loop_num, bool *res) |
116 | { |
117 | tree scev; |
118 | |
119 | if (chrec == chrec_not_analyzed_yet |
120 | || chrec == chrec_dont_know |
121 | || chrec_contains_symbols_defined_in_loop (chrec, loop_num)) |
122 | return false; |
123 | |
124 | STRIP_NOPS (chrec); |
125 | scev = hide_evolution_in_other_loops_than_loop (chrec, loop_num); |
126 | *res = !tree_contains_chrecs (scev, NULL); |
127 | return true; |
128 | } |
129 | |
130 | /* Build a polynomial chain of recurrence. */ |
131 | |
132 | inline tree |
133 | build_polynomial_chrec (unsigned loop_num, |
134 | tree left, |
135 | tree right) |
136 | { |
137 | bool val; |
138 | |
139 | if (left == chrec_dont_know |
140 | || right == chrec_dont_know) |
141 | return chrec_dont_know; |
142 | |
143 | if (!no_evolution_in_loop_p (chrec: left, loop_num, res: &val) |
144 | || !val) |
145 | return chrec_dont_know; |
146 | |
147 | /* Types of left and right sides of a chrec should be compatible, but |
148 | pointer CHRECs are special in that the evolution is of ptroff type. */ |
149 | if (POINTER_TYPE_P (TREE_TYPE (left))) |
150 | gcc_checking_assert (ptrofftype_p (TREE_TYPE (right))); |
151 | else |
152 | { |
153 | /* Pointer types should occur only on the left hand side, i.e. in |
154 | the base of the chrec, and not in the step. */ |
155 | gcc_checking_assert (!POINTER_TYPE_P (TREE_TYPE (right)) |
156 | && types_compatible_p (TREE_TYPE (left), |
157 | TREE_TYPE (right))); |
158 | } |
159 | |
160 | if (chrec_zerop (chrec: right)) |
161 | return left; |
162 | |
163 | tree chrec = build2 (POLYNOMIAL_CHREC, TREE_TYPE (left), left, right); |
164 | CHREC_VARIABLE (chrec) = loop_num; |
165 | return chrec; |
166 | } |
167 | |
168 | /* Determines whether the expression CHREC is a constant. */ |
169 | |
170 | inline bool |
171 | evolution_function_is_constant_p (const_tree chrec) |
172 | { |
173 | if (chrec == NULL_TREE) |
174 | return false; |
175 | |
176 | return is_gimple_min_invariant (chrec); |
177 | } |
178 | |
179 | /* Determine whether CHREC is an affine evolution function in LOOPNUM. */ |
180 | |
181 | inline bool |
182 | evolution_function_is_affine_in_loop (const_tree chrec, int loopnum) |
183 | { |
184 | if (chrec == NULL_TREE) |
185 | return false; |
186 | |
187 | switch (TREE_CODE (chrec)) |
188 | { |
189 | case POLYNOMIAL_CHREC: |
190 | if (evolution_function_is_invariant_p (CHREC_LEFT (chrec), loopnum) |
191 | && evolution_function_is_invariant_p (CHREC_RIGHT (chrec), loopnum)) |
192 | return true; |
193 | else |
194 | return false; |
195 | |
196 | default: |
197 | return false; |
198 | } |
199 | } |
200 | |
201 | /* Determine whether CHREC is an affine evolution function or not. */ |
202 | |
203 | inline bool |
204 | evolution_function_is_affine_p (const_tree chrec) |
205 | { |
206 | return chrec |
207 | && TREE_CODE (chrec) == POLYNOMIAL_CHREC |
208 | && evolution_function_is_invariant_p (CHREC_RIGHT (chrec), |
209 | CHREC_VARIABLE (chrec)) |
210 | && (TREE_CODE (CHREC_RIGHT (chrec)) != POLYNOMIAL_CHREC |
211 | || evolution_function_is_affine_p (CHREC_RIGHT (chrec))); |
212 | } |
213 | |
214 | /* Determines whether EXPR does not contains chrec expressions. */ |
215 | |
216 | inline bool |
217 | tree_does_not_contain_chrecs (const_tree expr) |
218 | { |
219 | return !tree_contains_chrecs (expr, NULL); |
220 | } |
221 | |
222 | /* Returns the type of the chrec. */ |
223 | |
224 | inline tree |
225 | chrec_type (const_tree chrec) |
226 | { |
227 | if (automatically_generated_chrec_p (chrec)) |
228 | return NULL_TREE; |
229 | |
230 | return TREE_TYPE (chrec); |
231 | } |
232 | |
233 | inline tree |
234 | chrec_fold_op (enum tree_code code, tree type, tree op0, tree op1) |
235 | { |
236 | switch (code) |
237 | { |
238 | case PLUS_EXPR: |
239 | return chrec_fold_plus (type, op0, op1); |
240 | |
241 | case MINUS_EXPR: |
242 | return chrec_fold_minus (type, op0, op1); |
243 | |
244 | case MULT_EXPR: |
245 | return chrec_fold_multiply (type, op0, op1); |
246 | |
247 | default: |
248 | gcc_unreachable (); |
249 | } |
250 | |
251 | } |
252 | |
253 | #endif /* GCC_TREE_CHREC_H */ |
254 | |