1 /* Graphite polyhedral representation.
2 Copyright (C) 2009-2019 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 #include <isl/options.h>
27 #include <isl/ctx.h>
28 #include <isl/val.h>
29 #include <isl/set.h>
30 #include <isl/union_set.h>
31 #include <isl/map.h>
32 #include <isl/union_map.h>
33 #include <isl/aff.h>
34 #include <isl/constraint.h>
35 #include <isl/flow.h>
36 #include <isl/ilp.h>
37 #include <isl/schedule.h>
38 #include <isl/ast_build.h>
39 #include <isl/schedule_node.h>
40 #include <isl/id.h>
41 #include <isl/space.h>
42
43 typedef struct poly_dr *poly_dr_p;
44
45 typedef struct poly_bb *poly_bb_p;
46
47 typedef struct scop *scop_p;
48
49 typedef unsigned graphite_dim_t;
50
51 static inline graphite_dim_t scop_nb_params (scop_p);
52
53 /* A data reference can write or read some memory or we
54 just know it may write some memory. */
55 enum poly_dr_type
56 {
57 PDR_READ,
58 /* PDR_MAY_READs are represented using PDR_READS. This does not
59 limit the expressiveness. */
60 PDR_WRITE,
61 PDR_MAY_WRITE
62 };
63
64 struct poly_dr
65 {
66 /* An identifier for this PDR. */
67 int id;
68
69 /* The number of data refs identical to this one in the PBB. */
70 int nb_refs;
71
72 /* A pointer to the gimple stmt containing this reference. */
73 gimple *stmt;
74
75 /* A pointer to the PBB that contains this data reference. */
76 poly_bb_p pbb;
77
78 enum poly_dr_type type;
79
80 /* The access polyhedron contains the polyhedral space this data
81 reference will access.
82
83 The polyhedron contains these dimensions:
84
85 - The alias set (a):
86 Every memory access is classified in at least one alias set.
87
88 - The subscripts (s_0, ..., s_n):
89 The memory is accessed using zero or more subscript dimensions.
90
91 - The iteration domain (variables and parameters)
92
93 Do not hardcode the dimensions. Use the following accessor functions:
94 - pdr_alias_set_dim
95 - pdr_subscript_dim
96 - pdr_iterator_dim
97 - pdr_parameter_dim
98
99 Example:
100
101 | int A[1335][123];
102 | int *p = malloc ();
103 |
104 | k = ...
105 | for i
106 | {
107 | if (unknown_function ())
108 | p = A;
109 | ... = p[?][?];
110 | for j
111 | A[i][j+k] = m;
112 | }
113
114 The data access A[i][j+k] in alias set "5" is described like this:
115
116 | i j k a s0 s1 1
117 | 0 0 0 1 0 0 -5 = 0
118 |-1 0 0 0 1 0 0 = 0
119 | 0 -1 -1 0 0 1 0 = 0
120 | 0 0 0 0 1 0 0 >= 0 # The last four lines describe the
121 | 0 0 0 0 0 1 0 >= 0 # array size.
122 | 0 0 0 0 -1 0 1335 >= 0
123 | 0 0 0 0 0 -1 123 >= 0
124
125 The pointer "*p" in alias set "5" and "7" is described as a union of
126 polyhedron:
127
128
129 | i k a s0 1
130 | 0 0 1 0 -5 = 0
131 | 0 0 0 1 0 >= 0
132
133 "or"
134
135 | i k a s0 1
136 | 0 0 1 0 -7 = 0
137 | 0 0 0 1 0 >= 0
138
139 "*p" accesses all of the object allocated with 'malloc'.
140
141 The scalar data access "m" is represented as an array with zero subscript
142 dimensions.
143
144 | i j k a 1
145 | 0 0 0 -1 15 = 0
146
147 The difference between the graphite internal format for access data and
148 the OpenSop format is in the order of columns.
149 Instead of having:
150
151 | i j k a s0 s1 1
152 | 0 0 0 1 0 0 -5 = 0
153 |-1 0 0 0 1 0 0 = 0
154 | 0 -1 -1 0 0 1 0 = 0
155 | 0 0 0 0 1 0 0 >= 0 # The last four lines describe the
156 | 0 0 0 0 0 1 0 >= 0 # array size.
157 | 0 0 0 0 -1 0 1335 >= 0
158 | 0 0 0 0 0 -1 123 >= 0
159
160 In OpenScop we have:
161
162 | a s0 s1 i j k 1
163 | 1 0 0 0 0 0 -5 = 0
164 | 0 1 0 -1 0 0 0 = 0
165 | 0 0 1 0 -1 -1 0 = 0
166 | 0 1 0 0 0 0 0 >= 0 # The last four lines describe the
167 | 0 0 1 0 0 0 0 >= 0 # array size.
168 | 0 -1 0 0 0 0 1335 >= 0
169 | 0 0 -1 0 0 0 123 >= 0
170
171 The OpenScop access function is printed as follows:
172
173 | 1 # The number of disjunct components in a union of access functions.
174 | R C O I L P # Described bellow.
175 | a s0 s1 i j k 1
176 | 1 0 0 0 0 0 -5 = 0
177 | 0 1 0 -1 0 0 0 = 0
178 | 0 0 1 0 -1 -1 0 = 0
179 | 0 1 0 0 0 0 0 >= 0 # The last four lines describe the
180 | 0 0 1 0 0 0 0 >= 0 # array size.
181 | 0 -1 0 0 0 0 1335 >= 0
182 | 0 0 -1 0 0 0 123 >= 0
183
184 Where:
185 - R: Number of rows.
186 - C: Number of columns.
187 - O: Number of output dimensions = alias set + number of subscripts.
188 - I: Number of input dimensions (iterators).
189 - L: Number of local (existentially quantified) dimensions.
190 - P: Number of parameters.
191
192 In the example, the vector "R C O I L P" is "7 7 3 2 0 1". */
193 isl_map *accesses;
194 isl_set *subscript_sizes;
195 };
196
197 #define PDR_ID(PDR) (PDR->id)
198 #define PDR_NB_REFS(PDR) (PDR->nb_refs)
199 #define PDR_PBB(PDR) (PDR->pbb)
200 #define PDR_TYPE(PDR) (PDR->type)
201 #define PDR_ACCESSES(PDR) (NULL)
202
203 void new_poly_dr (poly_bb_p, gimple *, enum poly_dr_type,
204 isl_map *, isl_set *);
205 void debug_pdr (poly_dr_p);
206 void print_pdr (FILE *, poly_dr_p);
207
208 static inline bool
pdr_read_p(poly_dr_p pdr)209 pdr_read_p (poly_dr_p pdr)
210 {
211 return PDR_TYPE (pdr) == PDR_READ;
212 }
213
214 /* Returns true when PDR is a "write". */
215
216 static inline bool
pdr_write_p(poly_dr_p pdr)217 pdr_write_p (poly_dr_p pdr)
218 {
219 return PDR_TYPE (pdr) == PDR_WRITE;
220 }
221
222 /* Returns true when PDR is a "may write". */
223
224 static inline bool
pdr_may_write_p(poly_dr_p pdr)225 pdr_may_write_p (poly_dr_p pdr)
226 {
227 return PDR_TYPE (pdr) == PDR_MAY_WRITE;
228 }
229
230 /* POLY_BB represents a blackbox in the polyhedral model. */
231
232 struct poly_bb
233 {
234 /* Pointer to a basic block or a statement in the compiler. */
235 gimple_poly_bb_p black_box;
236
237 /* Pointer to the SCOP containing this PBB. */
238 scop_p scop;
239
240 /* The iteration domain of this bb. The layout of this polyhedron
241 is I|G with I the iteration domain, G the context parameters.
242
243 Example:
244
245 for (i = a - 7*b + 8; i <= 3*a + 13*b + 20; i++)
246 for (j = 2; j <= 2*i + 5; j++)
247 for (k = 0; k <= 5; k++)
248 S (i,j,k)
249
250 Loop iterators: i, j, k
251 Parameters: a, b
252
253 | i >= a - 7b + 8
254 | i <= 3a + 13b + 20
255 | j >= 2
256 | j <= 2i + 5
257 | k >= 0
258 | k <= 5
259
260 The number of variables in the DOMAIN may change and is not
261 related to the number of loops in the original code. */
262 isl_set *domain;
263 isl_set *iterators;
264
265 /* The data references we access. */
266 vec<poly_dr_p> drs;
267
268 /* The last basic block generated for this pbb. */
269 basic_block new_bb;
270 };
271
272 #define PBB_BLACK_BOX(PBB) ((gimple_poly_bb_p) PBB->black_box)
273 #define PBB_SCOP(PBB) (PBB->scop)
274 #define PBB_DRS(PBB) (PBB->drs)
275
276 extern poly_bb_p new_poly_bb (scop_p, gimple_poly_bb_p);
277 extern void print_pbb_domain (FILE *, poly_bb_p);
278 extern void print_pbb (FILE *, poly_bb_p);
279 extern void print_scop_context (FILE *, scop_p);
280 extern void print_scop (FILE *, scop_p);
281 extern void debug_pbb_domain (poly_bb_p);
282 extern void debug_pbb (poly_bb_p);
283 extern void print_pdrs (FILE *, poly_bb_p);
284 extern void debug_pdrs (poly_bb_p);
285 extern void debug_scop_context (scop_p);
286 extern void debug_scop (scop_p);
287 extern void print_scop_params (FILE *, scop_p);
288 extern void debug_scop_params (scop_p);
289 extern void print_iteration_domain (FILE *, poly_bb_p);
290 extern void print_iteration_domains (FILE *, scop_p);
291 extern void debug_iteration_domain (poly_bb_p);
292 extern void debug_iteration_domains (scop_p);
293 extern void print_isl_set (FILE *, isl_set *);
294 extern void print_isl_map (FILE *, isl_map *);
295 extern void print_isl_union_map (FILE *, isl_union_map *);
296 extern void print_isl_aff (FILE *, isl_aff *);
297 extern void print_isl_constraint (FILE *, isl_constraint *);
298 extern void print_isl_schedule (FILE *, isl_schedule *);
299 extern void debug_isl_schedule (isl_schedule *);
300 extern void print_isl_ast (FILE *, isl_ast_node *);
301 extern void debug_isl_ast (isl_ast_node *);
302 extern void debug_isl_set (isl_set *);
303 extern void debug_isl_map (isl_map *);
304 extern void debug_isl_union_map (isl_union_map *);
305 extern void debug_isl_aff (isl_aff *);
306 extern void debug_isl_constraint (isl_constraint *);
307 extern void debug_gmp_value (mpz_t);
308 extern void debug_scop_pbb (scop_p scop, int i);
309 extern void print_schedule_ast (FILE *, __isl_keep isl_schedule *, scop_p);
310 extern void debug_schedule_ast (__isl_keep isl_schedule *, scop_p);
311
312 /* The basic block of the PBB. */
313
314 static inline basic_block
pbb_bb(poly_bb_p pbb)315 pbb_bb (poly_bb_p pbb)
316 {
317 return GBB_BB (PBB_BLACK_BOX (pbb));
318 }
319
320 static inline int
pbb_index(poly_bb_p pbb)321 pbb_index (poly_bb_p pbb)
322 {
323 return pbb_bb (pbb)->index;
324 }
325
326 /* The loop of the PBB. */
327
328 static inline loop_p
pbb_loop(poly_bb_p pbb)329 pbb_loop (poly_bb_p pbb)
330 {
331 return gbb_loop (PBB_BLACK_BOX (pbb));
332 }
333
334 /* The scop that contains the PDR. */
335
336 static inline scop_p
pdr_scop(poly_dr_p pdr)337 pdr_scop (poly_dr_p pdr)
338 {
339 return PBB_SCOP (PDR_PBB (pdr));
340 }
341
342 /* Set black box of PBB to BLACKBOX. */
343
344 static inline void
pbb_set_black_box(poly_bb_p pbb,gimple_poly_bb_p black_box)345 pbb_set_black_box (poly_bb_p pbb, gimple_poly_bb_p black_box)
346 {
347 pbb->black_box = black_box;
348 }
349
350 /* A helper structure to keep track of data references, polyhedral BBs, and
351 alias sets. */
352
353 struct dr_info
354 {
355 enum {
356 invalid_alias_set = -1
357 };
358 /* The data reference. */
359 data_reference_p dr;
360
361 /* The polyhedral BB containing this DR. */
362 poly_bb_p pbb;
363
364 /* ALIAS_SET is the SCC number assigned by a graph_dfs of the alias graph.
365 -1 is an invalid alias set. */
366 int alias_set;
367
368 /* Construct a DR_INFO from a data reference DR, an ALIAS_SET, and a PBB. */
369 dr_info (data_reference_p dr, poly_bb_p pbb,
370 int alias_set = invalid_alias_set)
drdr_info371 : dr (dr), pbb (pbb), alias_set (alias_set) {}
372 };
373
374 /* A SCOP is a Static Control Part of the program, simple enough to be
375 represented in polyhedral form. */
376 struct scop
377 {
378 /* A SCOP is defined as a SESE region. */
379 sese_info_p scop_info;
380
381 /* Number of parameters in SCoP. */
382 graphite_dim_t nb_params;
383
384 /* The maximum alias set as assigned to drs by build_alias_sets. */
385 unsigned max_alias_set;
386
387 /* All the basic blocks in this scop that contain memory references
388 and that will be represented as statements in the polyhedral
389 representation. */
390 vec<poly_bb_p> pbbs;
391
392 /* All the data references in this scop. */
393 vec<dr_info> drs;
394
395 /* The context describes known restrictions concerning the parameters
396 and relations in between the parameters.
397
398 void f (int8_t a, uint_16_t b) {
399 c = 2 a + b;
400 ...
401 }
402
403 Here we can add these restrictions to the context:
404
405 -128 >= a >= 127
406 0 >= b >= 65,535
407 c = 2a + b */
408 isl_set *param_context;
409
410 /* The context used internally by isl. */
411 isl_ctx *isl_context;
412
413 /* SCoP original schedule. */
414 isl_schedule *original_schedule;
415
416 /* SCoP transformed schedule. */
417 isl_schedule *transformed_schedule;
418
419 /* The data dependence relation among the data references in this scop. */
420 isl_union_map *dependence;
421 };
422
423 extern scop_p new_scop (edge, edge);
424 extern void free_scop (scop_p);
425 extern gimple_poly_bb_p new_gimple_poly_bb (basic_block, vec<data_reference_p>,
426 vec<scalar_use>, vec<tree>);
427 extern bool apply_poly_transforms (scop_p);
428
429 /* Set the region of SCOP to REGION. */
430
431 static inline void
scop_set_region(scop_p scop,sese_info_p region)432 scop_set_region (scop_p scop, sese_info_p region)
433 {
434 scop->scop_info = region;
435 }
436
437 /* Returns the number of parameters for SCOP. */
438
439 static inline graphite_dim_t
scop_nb_params(scop_p scop)440 scop_nb_params (scop_p scop)
441 {
442 return scop->nb_params;
443 }
444
445 /* Set the number of params of SCOP to NB_PARAMS. */
446
447 static inline void
scop_set_nb_params(scop_p scop,graphite_dim_t nb_params)448 scop_set_nb_params (scop_p scop, graphite_dim_t nb_params)
449 {
450 scop->nb_params = nb_params;
451 }
452
453 extern void scop_get_dependences (scop_p scop);
454
455 bool
456 carries_deps (__isl_keep isl_union_map *schedule,
457 __isl_keep isl_union_map *deps,
458 int depth);
459
460 extern bool build_poly_scop (scop_p);
461 extern bool graphite_regenerate_ast_isl (scop_p);
462 extern void build_scops (vec<scop_p> *);
463 extern tree cached_scalar_evolution_in_region (const sese_l &, loop_p, tree);
464 extern void dot_all_sese (FILE *, vec<sese_l> &);
465 extern void dot_sese (sese_l &);
466 extern void dot_cfg ();
467
468 #endif
469