1 /* Graphite polyhedral representation.
2 Copyright (C) 2009-2023 Free Software Foundation, Inc.
3 Contributed by Sebastian Pop <sebastian.pop@amd.com> and
4 Tobias Grosser <grosser@fim.uni-passau.de>.
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_GRAPHITE_POLY_H
23 #define GCC_GRAPHITE_POLY_H
24
25 #include "sese.h"
26
27 typedef struct poly_dr *poly_dr_p;
28
29 typedef struct poly_bb *poly_bb_p;
30
31 typedef struct scop *scop_p;
32
33 typedef unsigned graphite_dim_t;
34
35 inline graphite_dim_t scop_nb_params (scop_p);
36
37 /* A data reference can write or read some memory or we
38 just know it may write some memory. */
39 enum poly_dr_type
40 {
41 PDR_READ,
42 /* PDR_MAY_READs are represented using PDR_READS. This does not
43 limit the expressiveness. */
44 PDR_WRITE,
45 PDR_MAY_WRITE
46 };
47
48 struct poly_dr
49 {
50 /* An identifier for this PDR. */
51 int id;
52
53 /* The number of data refs identical to this one in the PBB. */
54 int nb_refs;
55
56 /* A pointer to the gimple stmt containing this reference. */
57 gimple *stmt;
58
59 /* A pointer to the PBB that contains this data reference. */
60 poly_bb_p pbb;
61
62 enum poly_dr_type type;
63
64 /* The access polyhedron contains the polyhedral space this data
65 reference will access.
66
67 The polyhedron contains these dimensions:
68
69 - The alias set (a):
70 Every memory access is classified in at least one alias set.
71
72 - The subscripts (s_0, ..., s_n):
73 The memory is accessed using zero or more subscript dimensions.
74
75 - The iteration domain (variables and parameters)
76
77 Do not hardcode the dimensions. Use the following accessor functions:
78 - pdr_alias_set_dim
79 - pdr_subscript_dim
80 - pdr_iterator_dim
81 - pdr_parameter_dim
82
83 Example:
84
85 | int A[1335][123];
86 | int *p = malloc ();
87 |
88 | k = ...
89 | for i
90 | {
91 | if (unknown_function ())
92 | p = A;
93 | ... = p[?][?];
94 | for j
95 | A[i][j+k] = m;
96 | }
97
98 The data access A[i][j+k] in alias set "5" is described like this:
99
100 | i j k a s0 s1 1
101 | 0 0 0 1 0 0 -5 = 0
102 |-1 0 0 0 1 0 0 = 0
103 | 0 -1 -1 0 0 1 0 = 0
104 | 0 0 0 0 1 0 0 >= 0 # The last four lines describe the
105 | 0 0 0 0 0 1 0 >= 0 # array size.
106 | 0 0 0 0 -1 0 1335 >= 0
107 | 0 0 0 0 0 -1 123 >= 0
108
109 The pointer "*p" in alias set "5" and "7" is described as a union of
110 polyhedron:
111
112
113 | i k a s0 1
114 | 0 0 1 0 -5 = 0
115 | 0 0 0 1 0 >= 0
116
117 "or"
118
119 | i k a s0 1
120 | 0 0 1 0 -7 = 0
121 | 0 0 0 1 0 >= 0
122
123 "*p" accesses all of the object allocated with 'malloc'.
124
125 The scalar data access "m" is represented as an array with zero subscript
126 dimensions.
127
128 | i j k a 1
129 | 0 0 0 -1 15 = 0
130
131 The difference between the graphite internal format for access data and
132 the OpenSop format is in the order of columns.
133 Instead of having:
134
135 | i j k a s0 s1 1
136 | 0 0 0 1 0 0 -5 = 0
137 |-1 0 0 0 1 0 0 = 0
138 | 0 -1 -1 0 0 1 0 = 0
139 | 0 0 0 0 1 0 0 >= 0 # The last four lines describe the
140 | 0 0 0 0 0 1 0 >= 0 # array size.
141 | 0 0 0 0 -1 0 1335 >= 0
142 | 0 0 0 0 0 -1 123 >= 0
143
144 In OpenScop we have:
145
146 | a s0 s1 i j k 1
147 | 1 0 0 0 0 0 -5 = 0
148 | 0 1 0 -1 0 0 0 = 0
149 | 0 0 1 0 -1 -1 0 = 0
150 | 0 1 0 0 0 0 0 >= 0 # The last four lines describe the
151 | 0 0 1 0 0 0 0 >= 0 # array size.
152 | 0 -1 0 0 0 0 1335 >= 0
153 | 0 0 -1 0 0 0 123 >= 0
154
155 The OpenScop access function is printed as follows:
156
157 | 1 # The number of disjunct components in a union of access functions.
158 | R C O I L P # Described bellow.
159 | a s0 s1 i j k 1
160 | 1 0 0 0 0 0 -5 = 0
161 | 0 1 0 -1 0 0 0 = 0
162 | 0 0 1 0 -1 -1 0 = 0
163 | 0 1 0 0 0 0 0 >= 0 # The last four lines describe the
164 | 0 0 1 0 0 0 0 >= 0 # array size.
165 | 0 -1 0 0 0 0 1335 >= 0
166 | 0 0 -1 0 0 0 123 >= 0
167
168 Where:
169 - R: Number of rows.
170 - C: Number of columns.
171 - O: Number of output dimensions = alias set + number of subscripts.
172 - I: Number of input dimensions (iterators).
173 - L: Number of local (existentially quantified) dimensions.
174 - P: Number of parameters.
175
176 In the example, the vector "R C O I L P" is "7 7 3 2 0 1". */
177 isl_map *accesses;
178 isl_set *subscript_sizes;
179 };
180
181 #define PDR_ID(PDR) (PDR->id)
182 #define PDR_NB_REFS(PDR) (PDR->nb_refs)
183 #define PDR_PBB(PDR) (PDR->pbb)
184 #define PDR_TYPE(PDR) (PDR->type)
185 #define PDR_ACCESSES(PDR) (NULL)
186
187 void new_poly_dr (poly_bb_p, gimple *, enum poly_dr_type,
188 isl_map *, isl_set *);
189 void debug_pdr (poly_dr_p);
190 void print_pdr (FILE *, poly_dr_p);
191
192 inline bool
193 pdr_read_p (poly_dr_p pdr)
194 {
195 return PDR_TYPE (pdr) == PDR_READ;
196 }
197
198 /* Returns true when PDR is a "write". */
199
200 inline bool
201 pdr_write_p (poly_dr_p pdr)
202 {
203 return PDR_TYPE (pdr) == PDR_WRITE;
204 }
205
206 /* Returns true when PDR is a "may write". */
207
208 inline bool
209 pdr_may_write_p (poly_dr_p pdr)
210 {
211 return PDR_TYPE (pdr) == PDR_MAY_WRITE;
212 }
213
214 /* POLY_BB represents a blackbox in the polyhedral model. */
215
216 struct poly_bb
217 {
218 /* Pointer to a basic block or a statement in the compiler. */
219 gimple_poly_bb_p black_box;
220
221 /* Pointer to the SCOP containing this PBB. */
222 scop_p scop;
223
224 /* The iteration domain of this bb. The layout of this polyhedron
225 is I|G with I the iteration domain, G the context parameters.
226
227 Example:
228
229 for (i = a - 7*b + 8; i <= 3*a + 13*b + 20; i++)
230 for (j = 2; j <= 2*i + 5; j++)
231 for (k = 0; k <= 5; k++)
232 S (i,j,k)
233
234 Loop iterators: i, j, k
235 Parameters: a, b
236
237 | i >= a - 7b + 8
238 | i <= 3a + 13b + 20
239 | j >= 2
240 | j <= 2i + 5
241 | k >= 0
242 | k <= 5
243
244 The number of variables in the DOMAIN may change and is not
245 related to the number of loops in the original code. */
246 isl_set *domain;
247 isl_set *iterators;
248
249 /* The data references we access. */
250 vec<poly_dr_p> drs;
251
252 /* The last basic block generated for this pbb. */
253 basic_block new_bb;
254 };
255
256 #define PBB_BLACK_BOX(PBB) ((gimple_poly_bb_p) PBB->black_box)
257 #define PBB_SCOP(PBB) (PBB->scop)
258 #define PBB_DRS(PBB) (PBB->drs)
259
260 extern poly_bb_p new_poly_bb (scop_p, gimple_poly_bb_p);
261 extern void print_pbb_domain (FILE *, poly_bb_p);
262 extern void print_pbb (FILE *, poly_bb_p);
263 extern void print_scop_context (FILE *, scop_p);
264 extern void print_scop (FILE *, scop_p);
265 extern void debug_pbb_domain (poly_bb_p);
266 extern void debug_pbb (poly_bb_p);
267 extern void print_pdrs (FILE *, poly_bb_p);
268 extern void debug_pdrs (poly_bb_p);
269 extern void debug_scop_context (scop_p);
270 extern void debug_scop (scop_p);
271 extern void print_scop_params (FILE *, scop_p);
272 extern void debug_scop_params (scop_p);
273 extern void print_iteration_domain (FILE *, poly_bb_p);
274 extern void print_iteration_domains (FILE *, scop_p);
275 extern void debug_iteration_domain (poly_bb_p);
276 extern void debug_iteration_domains (scop_p);
277 extern void print_isl_set (FILE *, isl_set *);
278 extern void print_isl_map (FILE *, isl_map *);
279 extern void print_isl_union_map (FILE *, isl_union_map *);
280 extern void print_isl_aff (FILE *, isl_aff *);
281 extern void print_isl_constraint (FILE *, isl_constraint *);
282 extern void print_isl_schedule (FILE *, isl_schedule *);
283 extern void debug_isl_schedule (isl_schedule *);
284 extern void print_isl_ast (FILE *, isl_ast_node *);
285 extern void debug_isl_ast (isl_ast_node *);
286 extern void debug_isl_set (isl_set *);
287 extern void debug_isl_map (isl_map *);
288 extern void debug_isl_union_map (isl_union_map *);
289 extern void debug_isl_aff (isl_aff *);
290 extern void debug_isl_constraint (isl_constraint *);
291 extern void debug_gmp_value (mpz_t);
292 extern void debug_scop_pbb (scop_p scop, int i);
293 extern void print_schedule_ast (FILE *, __isl_keep isl_schedule *, scop_p);
294 extern void debug_schedule_ast (__isl_keep isl_schedule *, scop_p);
295
296 /* The basic block of the PBB. */
297
298 inline basic_block
299 pbb_bb (poly_bb_p pbb)
300 {
301 return GBB_BB (PBB_BLACK_BOX (pbb));
302 }
303
304 inline int
305 pbb_index (poly_bb_p pbb)
306 {
307 return pbb_bb (pbb)->index;
308 }
309
310 /* The loop of the PBB. */
311
312 inline loop_p
313 pbb_loop (poly_bb_p pbb)
314 {
315 return gbb_loop (PBB_BLACK_BOX (pbb));
316 }
317
318 /* The scop that contains the PDR. */
319
320 inline scop_p
321 pdr_scop (poly_dr_p pdr)
322 {
323 return PBB_SCOP (PDR_PBB (pdr));
324 }
325
326 /* Set black box of PBB to BLACKBOX. */
327
328 inline void
329 pbb_set_black_box (poly_bb_p pbb, gimple_poly_bb_p black_box)
330 {
331 pbb->black_box = black_box;
332 }
333
334 /* A helper structure to keep track of data references, polyhedral BBs, and
335 alias sets. */
336
337 struct dr_info
338 {
339 enum {
340 invalid_alias_set = -1
341 };
342 /* The data reference. */
343 data_reference_p dr;
344
345 /* The polyhedral BB containing this DR. */
346 poly_bb_p pbb;
347
348 /* ALIAS_SET is the SCC number assigned by a graph_dfs of the alias graph.
349 -1 is an invalid alias set. */
350 int alias_set;
351
352 /* Construct a DR_INFO from a data reference DR, an ALIAS_SET, and a PBB. */
353 dr_info (data_reference_p dr, poly_bb_p pbb,
354 int alias_set = invalid_alias_set)
355 : dr (dr), pbb (pbb), alias_set (alias_set) {}
356 };
357
358 /* A SCOP is a Static Control Part of the program, simple enough to be
359 represented in polyhedral form. */
360 struct scop
361 {
362 /* A SCOP is defined as a SESE region. */
363 sese_info_p scop_info;
364
365 /* Number of parameters in SCoP. */
366 graphite_dim_t nb_params;
367
368 /* The maximum alias set as assigned to drs by build_alias_sets. */
369 unsigned max_alias_set;
370
371 /* All the basic blocks in this scop that contain memory references
372 and that will be represented as statements in the polyhedral
373 representation. */
374 vec<poly_bb_p> pbbs;
375
376 /* All the data references in this scop. */
377 vec<dr_info> drs;
378
379 /* The context describes known restrictions concerning the parameters
380 and relations in between the parameters.
381
382 void f (int8_t a, uint_16_t b) {
383 c = 2 a + b;
384 ...
385 }
386
387 Here we can add these restrictions to the context:
388
389 -128 >= a >= 127
390 0 >= b >= 65,535
391 c = 2a + b */
392 isl_set *param_context;
393
394 /* The context used internally by isl. */
395 isl_ctx *isl_context;
396
397 /* SCoP original schedule. */
398 isl_schedule *original_schedule;
399
400 /* SCoP transformed schedule. */
401 isl_schedule *transformed_schedule;
402
403 /* The data dependence relation among the data references in this scop. */
404 isl_union_map *dependence;
405 };
406
407 extern scop_p new_scop (edge, edge);
408 extern void free_scop (scop_p);
409 extern gimple_poly_bb_p new_gimple_poly_bb (basic_block, vec<data_reference_p>,
410 vec<scalar_use>, vec<tree>);
411 extern bool apply_poly_transforms (scop_p);
412
413 /* Set the region of SCOP to REGION. */
414
415 inline void
416 scop_set_region (scop_p scop, sese_info_p region)
417 {
418 scop->scop_info = region;
419 }
420
421 /* Returns the number of parameters for SCOP. */
422
423 inline graphite_dim_t
424 scop_nb_params (scop_p scop)
425 {
426 return scop->nb_params;
427 }
428
429 /* Set the number of params of SCOP to NB_PARAMS. */
430
431 inline void
432 scop_set_nb_params (scop_p scop, graphite_dim_t nb_params)
433 {
434 scop->nb_params = nb_params;
435 }
436
437 extern void scop_get_dependences (scop_p scop);
438
439 bool
440 carries_deps (__isl_keep isl_union_map *schedule,
441 __isl_keep isl_union_map *deps,
442 int depth);
443
444 extern bool build_poly_scop (scop_p);
445 extern bool graphite_regenerate_ast_isl (scop_p);
446 extern void build_scops (vec<scop_p> *);
447 extern tree cached_scalar_evolution_in_region (const sese_l &, loop_p, tree);
448 extern void dot_all_sese (FILE *, vec<sese_l> &);
449 extern void dot_sese (sese_l &);
450 extern void dot_cfg ();
451
452 #endif