1 | /* Chains of recurrences. |
2 | Copyright (C) 2003-2017 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 GTY(()) tree chrec_dont_know; |
30 | extern GTY(()) tree chrec_known; |
31 | |
32 | /* After having added an automatically generated element, please |
33 | include it in the following function. */ |
34 | |
35 | static inline bool |
36 | automatically_generated_chrec_p (const_tree chrec) |
37 | { |
38 | return (chrec == chrec_dont_know |
39 | || chrec == chrec_known); |
40 | } |
41 | |
42 | /* The tree nodes aka. CHRECs. */ |
43 | |
44 | static inline bool |
45 | tree_is_chrec (const_tree expr) |
46 | { |
47 | if (TREE_CODE (expr) == POLYNOMIAL_CHREC |
48 | || automatically_generated_chrec_p (expr)) |
49 | return true; |
50 | else |
51 | return false; |
52 | } |
53 | |
54 | |
55 | enum ev_direction {EV_DIR_GROWS, EV_DIR_DECREASES, EV_DIR_UNKNOWN}; |
56 | enum ev_direction scev_direction (const_tree); |
57 | |
58 | /* Chrec folding functions. */ |
59 | extern tree chrec_fold_plus (tree, tree, tree); |
60 | extern tree chrec_fold_minus (tree, tree, tree); |
61 | extern tree chrec_fold_multiply (tree, tree, tree); |
62 | extern tree chrec_convert (tree, tree, gimple *, bool = true, tree = NULL); |
63 | extern tree chrec_convert_rhs (tree, tree, gimple *); |
64 | extern tree chrec_convert_aggressive (tree, tree, bool *); |
65 | |
66 | /* Operations. */ |
67 | extern tree chrec_apply (unsigned, tree, tree); |
68 | extern tree chrec_apply_map (tree, vec<tree> ); |
69 | extern tree chrec_replace_initial_condition (tree, tree); |
70 | extern tree initial_condition (tree); |
71 | extern tree initial_condition_in_loop_num (tree, unsigned); |
72 | extern tree evolution_part_in_loop_num (tree, unsigned); |
73 | extern tree hide_evolution_in_other_loops_than_loop (tree, unsigned); |
74 | extern tree reset_evolution_in_loop (unsigned, tree, tree); |
75 | extern tree chrec_merge (tree, tree); |
76 | extern void for_each_scev_op (tree *, bool (*) (tree *, void *), void *); |
77 | extern bool convert_affine_scev (struct loop *, tree, tree *, tree *, gimple *, |
78 | bool, tree = NULL); |
79 | |
80 | /* Observers. */ |
81 | extern bool eq_evolutions_p (const_tree, const_tree); |
82 | extern bool is_multivariate_chrec (const_tree); |
83 | extern bool chrec_contains_symbols (const_tree); |
84 | extern bool chrec_contains_symbols_defined_in_loop (const_tree, unsigned); |
85 | extern bool chrec_contains_undetermined (const_tree); |
86 | extern bool tree_contains_chrecs (const_tree, int *); |
87 | extern bool evolution_function_is_affine_multivariate_p (const_tree, int); |
88 | extern bool evolution_function_is_univariate_p (const_tree); |
89 | extern unsigned nb_vars_in_chrec (tree); |
90 | extern bool evolution_function_is_invariant_p (tree, int); |
91 | extern bool scev_is_linear_expression (tree); |
92 | extern bool evolution_function_right_is_integer_cst (const_tree); |
93 | |
94 | /* Determines whether CHREC is equal to zero. */ |
95 | |
96 | static inline bool |
97 | chrec_zerop (const_tree chrec) |
98 | { |
99 | if (chrec == NULL_TREE) |
100 | return false; |
101 | |
102 | if (TREE_CODE (chrec) == INTEGER_CST) |
103 | return integer_zerop (chrec); |
104 | |
105 | return false; |
106 | } |
107 | |
108 | /* Determines whether CHREC is a loop invariant with respect to LOOP_NUM. |
109 | Set the result in RES and return true when the property can be computed. */ |
110 | |
111 | static inline bool |
112 | no_evolution_in_loop_p (tree chrec, unsigned loop_num, bool *res) |
113 | { |
114 | tree scev; |
115 | |
116 | if (chrec == chrec_not_analyzed_yet |
117 | || chrec == chrec_dont_know |
118 | || chrec_contains_symbols_defined_in_loop (chrec, loop_num)) |
119 | return false; |
120 | |
121 | STRIP_NOPS (chrec); |
122 | scev = hide_evolution_in_other_loops_than_loop (chrec, loop_num); |
123 | *res = !tree_contains_chrecs (scev, NULL); |
124 | return true; |
125 | } |
126 | |
127 | /* Build a polynomial chain of recurrence. */ |
128 | |
129 | static inline tree |
130 | build_polynomial_chrec (unsigned loop_num, |
131 | tree left, |
132 | tree right) |
133 | { |
134 | bool val; |
135 | |
136 | if (left == chrec_dont_know |
137 | || right == chrec_dont_know) |
138 | return chrec_dont_know; |
139 | |
140 | if (!no_evolution_in_loop_p (left, loop_num, &val) |
141 | || !val) |
142 | return chrec_dont_know; |
143 | |
144 | /* Types of left and right sides of a chrec should be compatible, but |
145 | pointer CHRECs are special in that the evolution is of ptroff type. */ |
146 | if (POINTER_TYPE_P (TREE_TYPE (left))) |
147 | gcc_checking_assert (ptrofftype_p (TREE_TYPE (right))); |
148 | else |
149 | { |
150 | /* Pointer types should occur only on the left hand side, i.e. in |
151 | the base of the chrec, and not in the step. */ |
152 | gcc_checking_assert (!POINTER_TYPE_P (TREE_TYPE (right)) |
153 | && types_compatible_p (TREE_TYPE (left), |
154 | TREE_TYPE (right))); |
155 | } |
156 | |
157 | if (chrec_zerop (right)) |
158 | return left; |
159 | |
160 | tree chrec = build2 (POLYNOMIAL_CHREC, TREE_TYPE (left), left, right); |
161 | CHREC_VARIABLE (chrec) = loop_num; |
162 | return chrec; |
163 | } |
164 | |
165 | /* Determines whether the expression CHREC is a constant. */ |
166 | |
167 | static inline bool |
168 | evolution_function_is_constant_p (const_tree chrec) |
169 | { |
170 | if (chrec == NULL_TREE) |
171 | return false; |
172 | |
173 | if (CONSTANT_CLASS_P (chrec)) |
174 | return true; |
175 | return is_gimple_min_invariant (chrec); |
176 | } |
177 | |
178 | /* Determine whether CHREC is an affine evolution function in LOOPNUM. */ |
179 | |
180 | static inline bool |
181 | evolution_function_is_affine_in_loop (const_tree chrec, int loopnum) |
182 | { |
183 | if (chrec == NULL_TREE) |
184 | return false; |
185 | |
186 | switch (TREE_CODE (chrec)) |
187 | { |
188 | case POLYNOMIAL_CHREC: |
189 | if (evolution_function_is_invariant_p (CHREC_LEFT (chrec), loopnum) |
190 | && evolution_function_is_invariant_p (CHREC_RIGHT (chrec), loopnum)) |
191 | return true; |
192 | else |
193 | return false; |
194 | |
195 | default: |
196 | return false; |
197 | } |
198 | } |
199 | |
200 | /* Determine whether CHREC is an affine evolution function or not. */ |
201 | |
202 | static inline bool |
203 | evolution_function_is_affine_p (const_tree chrec) |
204 | { |
205 | return chrec |
206 | && TREE_CODE (chrec) == POLYNOMIAL_CHREC |
207 | && evolution_function_is_invariant_p (CHREC_RIGHT (chrec), |
208 | CHREC_VARIABLE (chrec)) |
209 | && (TREE_CODE (CHREC_RIGHT (chrec)) != POLYNOMIAL_CHREC |
210 | || evolution_function_is_affine_p (CHREC_RIGHT (chrec))); |
211 | } |
212 | |
213 | /* Determines whether EXPR does not contains chrec expressions. */ |
214 | |
215 | static inline bool |
216 | tree_does_not_contain_chrecs (const_tree expr) |
217 | { |
218 | return !tree_contains_chrecs (expr, NULL); |
219 | } |
220 | |
221 | /* Returns the type of the chrec. */ |
222 | |
223 | static inline tree |
224 | chrec_type (const_tree chrec) |
225 | { |
226 | if (automatically_generated_chrec_p (chrec)) |
227 | return NULL_TREE; |
228 | |
229 | return TREE_TYPE (chrec); |
230 | } |
231 | |
232 | static inline tree |
233 | chrec_fold_op (enum tree_code code, tree type, tree op0, tree op1) |
234 | { |
235 | switch (code) |
236 | { |
237 | case PLUS_EXPR: |
238 | return chrec_fold_plus (type, op0, op1); |
239 | |
240 | case MINUS_EXPR: |
241 | return chrec_fold_minus (type, op0, op1); |
242 | |
243 | case MULT_EXPR: |
244 | return chrec_fold_multiply (type, op0, op1); |
245 | |
246 | default: |
247 | gcc_unreachable (); |
248 | } |
249 | |
250 | } |
251 | |
252 | #endif /* GCC_TREE_CHREC_H */ |
253 | |