1 /* Single entry single exit control flow regions.
2 Copyright (C) 2008-2023 Free Software Foundation, Inc.
3 Contributed by Jan Sjodin <jan.sjodin@amd.com> and
4 Sebastian Pop <sebastian.pop@amd.com>.
5
6 This file is part of GCC.
7
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3, or (at your option)
11 any later version.
12
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
21
22 #ifndef GCC_SESE_H
23 #define GCC_SESE_H
24
25 typedef struct ifsese_s *ifsese;
26
27 /* A Single Entry, Single Exit region is a part of the CFG delimited
28 by two edges. */
29 class sese_l
30 {
31 public:
32 sese_l (edge e, edge x) : entry (e), exit (x) {}
33
34 operator bool () const { return entry && exit; }
35
36 edge entry;
37 edge exit;
38 };
39
40 void print_edge (FILE *file, const_edge e);
41 void print_sese (FILE *file, const sese_l &s);
42 void dump_edge (const_edge e);
43 void dump_sese (const sese_l &);
44
45 /* Get the entry of an sese S. */
46
47 inline basic_block
48 get_entry_bb (const sese_l &s)
49 {
50 return s.entry->dest;
51 }
52
53 /* Get the exit of an sese S. */
54
55 inline basic_block
56 get_exit_bb (const sese_l &s)
57 {
58 return s.exit->src;
59 }
60
61 /* Returns the index of V where ELEM can be found. -1 Otherwise. */
62 template<typename T>
63 int
64 vec_find (const vec<T> &v, const T &elem)
65 {
66 int i;
67 T t;
68 FOR_EACH_VEC_ELT (v, i, t)
69 if (elem == t)
70 return i;
71 return -1;
72 }
73
74 /* A helper structure for bookkeeping information about a scop in graphite. */
75 typedef class sese_info_t
76 {
77 public:
78 /* The SESE region. */
79 sese_l region;
80
81 /* Liveout vars. */
82 bitmap liveout;
83
84 /* Liveout in debug stmts. */
85 bitmap debug_liveout;
86
87 /* Parameters used within the SCOP. */
88 vec<tree> params;
89
90 /* Maps an old name to a new decl. */
91 hash_map<tree, tree> *rename_map;
92
93 /* Basic blocks contained in this SESE. */
94 vec<basic_block> bbs;
95
96 /* The condition region generated for this sese. */
97 ifsese if_region;
98
99 } *sese_info_p;
100
101 extern sese_info_p new_sese_info (edge, edge);
102 extern void free_sese_info (sese_info_p);
103 extern void sese_insert_phis_for_liveouts (sese_info_p, basic_block, edge, edge);
104 extern class loop *outermost_loop_in_sese (sese_l &, basic_block);
105 extern tree scalar_evolution_in_region (const sese_l &, loop_p, tree);
106 extern bool scev_analyzable_p (tree, sese_l &);
107 extern bool invariant_in_sese_p_rec (tree, const sese_l &, bool *);
108 extern void sese_build_liveouts (sese_info_p);
109 extern bool sese_trivially_empty_bb_p (basic_block);
110
111 /* The number of parameters in REGION. */
112
113 inline unsigned
114 sese_nb_params (sese_info_p region)
115 {
116 return region->params.length ();
117 }
118
119 /* Checks whether BB is contained in the region delimited by ENTRY and
120 EXIT blocks. */
121
122 inline bool
123 bb_in_region (const_basic_block bb, const_basic_block entry, const_basic_block exit)
124 {
125 return dominated_by_p (CDI_DOMINATORS, bb, entry)
126 && !(dominated_by_p (CDI_DOMINATORS, bb, exit)
127 && !dominated_by_p (CDI_DOMINATORS, entry, exit));
128 }
129
130 /* Checks whether BB is contained in the region delimited by ENTRY and
131 EXIT blocks. */
132
133 inline bool
134 bb_in_sese_p (basic_block bb, const sese_l &r)
135 {
136 return bb_in_region (bb, r.entry->dest, r.exit->dest);
137 }
138
139 /* Returns true when STMT is defined in REGION. */
140
141 inline bool
142 stmt_in_sese_p (gimple *stmt, const sese_l &r)
143 {
144 basic_block bb = gimple_bb (stmt);
145 return bb && bb_in_sese_p (bb, r);
146 }
147
148 /* Returns true when NAME is defined in REGION. */
149
150 inline bool
151 defined_in_sese_p (tree name, const sese_l &r)
152 {
153 return stmt_in_sese_p (SSA_NAME_DEF_STMT (name), r);
154 }
155
156 /* Returns true when LOOP is in REGION. */
157
158 inline bool
159 loop_in_sese_p (class loop *loop, const sese_l ®ion)
160 {
161 return (bb_in_sese_p (loop->header, region)
162 && bb_in_sese_p (loop->latch, region));
163 }
164
165 /* Returns the loop depth of LOOP in REGION. The loop depth
166 is the same as the normal loop depth, but limited by a region.
167
168 Example:
169
170 loop_0
171 loop_1
172 {
173 S0
174 <- region start
175 S1
176
177 loop_2
178 S2
179
180 S3
181 <- region end
182 }
183
184 loop_0 does not exist in the region -> invalid
185 loop_1 exists, but is not completely contained in the region -> depth 0
186 loop_2 is completely contained -> depth 1 */
187
188 inline unsigned int
189 sese_loop_depth (const sese_l ®ion, loop_p loop)
190 {
191 unsigned int depth = 0;
192
193 while (loop_in_sese_p (loop, region))
194 {
195 depth++;
196 loop = loop_outer (loop);
197 }
198
199 return depth;
200 }
201
202 /* A single entry single exit specialized for conditions. */
203
204 typedef struct ifsese_s {
205 sese_info_p region;
206 sese_info_p true_region;
207 sese_info_p false_region;
208 } *ifsese;
209
210 extern ifsese move_sese_in_condition (sese_info_p);
211 extern void set_ifsese_condition (ifsese, tree);
212 extern edge get_true_edge_from_guard_bb (basic_block);
213 extern edge get_false_edge_from_guard_bb (basic_block);
214
215 inline edge
216 if_region_entry (ifsese if_region)
217 {
218 return if_region->region->region.entry;
219 }
220
221 inline edge
222 if_region_exit (ifsese if_region)
223 {
224 return if_region->region->region.exit;
225 }
226
227 inline basic_block
228 if_region_get_condition_block (ifsese if_region)
229 {
230 return if_region_entry (if_region)->dest;
231 }
232
233 typedef std::pair <gimple *, tree> scalar_use;
234
235 typedef struct gimple_poly_bb
236 {
237 basic_block bb;
238 struct poly_bb *pbb;
239
240 /* Lists containing the restrictions of the conditional statements
241 dominating this bb. This bb can only be executed, if all conditions
242 are true.
243
244 Example:
245
246 for (i = 0; i <= 20; i++)
247 {
248 A
249
250 if (2i <= 8)
251 B
252 }
253
254 So for B there is an additional condition (2i <= 8).
255
256 List of COND_EXPR and SWITCH_EXPR. A COND_EXPR is true only if the
257 corresponding element in CONDITION_CASES is not NULL_TREE. For a
258 SWITCH_EXPR the corresponding element in CONDITION_CASES is a
259 CASE_LABEL_EXPR. */
260 vec<gimple *> conditions;
261 vec<gimple *> condition_cases;
262 vec<data_reference_p> data_refs;
263 vec<scalar_use> read_scalar_refs;
264 vec<tree> write_scalar_refs;
265 } *gimple_poly_bb_p;
266
267 #define GBB_BB(GBB) (GBB)->bb
268 #define GBB_PBB(GBB) (GBB)->pbb
269 #define GBB_DATA_REFS(GBB) (GBB)->data_refs
270 #define GBB_CONDITIONS(GBB) (GBB)->conditions
271 #define GBB_CONDITION_CASES(GBB) (GBB)->condition_cases
272
273 /* Return the innermost loop that contains the basic block GBB. */
274
275 inline class loop *
276 gbb_loop (gimple_poly_bb_p gbb)
277 {
278 return GBB_BB (gbb)->loop_father;
279 }
280
281 /* Returns the gimple loop, that corresponds to the loop_iterator_INDEX.
282 If there is no corresponding gimple loop, we return NULL. */
283
284 inline loop_p
285 gbb_loop_at_index (gimple_poly_bb_p gbb, sese_l ®ion, int index)
286 {
287 loop_p loop = gbb_loop (gbb);
288 int depth = sese_loop_depth (region, loop);
289
290 while (--depth > index)
291 loop = loop_outer (loop);
292
293 gcc_assert (loop_in_sese_p (loop, region));
294
295 return loop;
296 }
297
298 /* The number of common loops in REGION for GBB1 and GBB2. */
299
300 inline int
301 nb_common_loops (sese_l ®ion, gimple_poly_bb_p gbb1, gimple_poly_bb_p gbb2)
302 {
303 loop_p l1 = gbb_loop (gbb1);
304 loop_p l2 = gbb_loop (gbb2);
305 loop_p common = find_common_loop (l1, l2);
306
307 return sese_loop_depth (region, common);
308 }
309
310 #endif