1 | /* Data references and dependences detectors. |
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_DATA_REF_H |
22 | #define GCC_TREE_DATA_REF_H |
23 | |
24 | #include "graphds.h" |
25 | #include "tree-chrec.h" |
26 | #include "opt-problem.h" |
27 | |
28 | /* |
29 | innermost_loop_behavior describes the evolution of the address of the memory |
30 | reference in the innermost enclosing loop. The address is expressed as |
31 | BASE + STEP * # of iteration, and base is further decomposed as the base |
32 | pointer (BASE_ADDRESS), loop invariant offset (OFFSET) and |
33 | constant offset (INIT). Examples, in loop nest |
34 | |
35 | for (i = 0; i < 100; i++) |
36 | for (j = 3; j < 100; j++) |
37 | |
38 | Example 1 Example 2 |
39 | data-ref a[j].b[i][j] *(p + x + 16B + 4B * j) |
40 | |
41 | |
42 | innermost_loop_behavior |
43 | base_address &a p |
44 | offset i * D_i x |
45 | init 3 * D_j + offsetof (b) 28 |
46 | step D_j 4 |
47 | |
48 | */ |
49 | struct innermost_loop_behavior |
50 | { |
51 | tree base_address; |
52 | tree offset; |
53 | tree init; |
54 | tree step; |
55 | |
56 | /* BASE_ADDRESS is known to be misaligned by BASE_MISALIGNMENT bytes |
57 | from an alignment boundary of BASE_ALIGNMENT bytes. For example, |
58 | if we had: |
59 | |
60 | struct S __attribute__((aligned(16))) { ... }; |
61 | |
62 | char *ptr; |
63 | ... *(struct S *) (ptr - 4) ...; |
64 | |
65 | the information would be: |
66 | |
67 | base_address: ptr |
68 | base_aligment: 16 |
69 | base_misalignment: 4 |
70 | init: -4 |
71 | |
72 | where init cancels the base misalignment. If instead we had a |
73 | reference to a particular field: |
74 | |
75 | struct S __attribute__((aligned(16))) { ... int f; ... }; |
76 | |
77 | char *ptr; |
78 | ... ((struct S *) (ptr - 4))->f ...; |
79 | |
80 | the information would be: |
81 | |
82 | base_address: ptr |
83 | base_aligment: 16 |
84 | base_misalignment: 4 |
85 | init: -4 + offsetof (S, f) |
86 | |
87 | where base_address + init might also be misaligned, and by a different |
88 | amount from base_address. */ |
89 | unsigned int base_alignment; |
90 | unsigned int base_misalignment; |
91 | |
92 | /* The largest power of two that divides OFFSET, capped to a suitably |
93 | high value if the offset is zero. This is a byte rather than a bit |
94 | quantity. */ |
95 | unsigned int offset_alignment; |
96 | |
97 | /* Likewise for STEP. */ |
98 | unsigned int step_alignment; |
99 | }; |
100 | |
101 | /* Describes the evolutions of indices of the memory reference. The indices |
102 | are indices of the ARRAY_REFs, indexes in artificial dimensions |
103 | added for member selection of records and the operands of MEM_REFs. |
104 | BASE_OBJECT is the part of the reference that is loop-invariant |
105 | (note that this reference does not have to cover the whole object |
106 | being accessed, in which case UNCONSTRAINED_BASE is set; hence it is |
107 | not recommended to use BASE_OBJECT in any code generation). |
108 | For the examples above, |
109 | |
110 | base_object: a *(p + x + 4B * j_0) |
111 | indices: {j_0, +, 1}_2 {16, +, 4}_2 |
112 | 4 |
113 | {i_0, +, 1}_1 |
114 | {j_0, +, 1}_2 |
115 | */ |
116 | |
117 | struct indices |
118 | { |
119 | /* The object. */ |
120 | tree base_object; |
121 | |
122 | /* A list of chrecs. Access functions of the indices. */ |
123 | vec<tree> access_fns; |
124 | |
125 | /* Whether BASE_OBJECT is an access representing the whole object |
126 | or whether the access could not be constrained. */ |
127 | bool unconstrained_base; |
128 | }; |
129 | |
130 | struct dr_alias |
131 | { |
132 | /* The alias information that should be used for new pointers to this |
133 | location. */ |
134 | struct ptr_info_def *ptr_info; |
135 | }; |
136 | |
137 | /* An integer vector. A vector formally consists of an element of a vector |
138 | space. A vector space is a set that is closed under vector addition |
139 | and scalar multiplication. In this vector space, an element is a list of |
140 | integers. */ |
141 | typedef HOST_WIDE_INT lambda_int; |
142 | typedef lambda_int *lambda_vector; |
143 | |
144 | /* An integer matrix. A matrix consists of m vectors of length n (IE |
145 | all vectors are the same length). */ |
146 | typedef lambda_vector *lambda_matrix; |
147 | |
148 | |
149 | |
150 | struct data_reference |
151 | { |
152 | /* A pointer to the statement that contains this DR. */ |
153 | gimple *stmt; |
154 | |
155 | /* A pointer to the memory reference. */ |
156 | tree ref; |
157 | |
158 | /* Auxiliary info specific to a pass. */ |
159 | void *aux; |
160 | |
161 | /* True when the data reference is in RHS of a stmt. */ |
162 | bool is_read; |
163 | |
164 | /* True when the data reference is conditional within STMT, |
165 | i.e. if it might not occur even when the statement is executed |
166 | and runs to completion. */ |
167 | bool is_conditional_in_stmt; |
168 | |
169 | /* Alias information for the data reference. */ |
170 | struct dr_alias alias; |
171 | |
172 | /* Behavior of the memory reference in the innermost loop. */ |
173 | struct innermost_loop_behavior innermost; |
174 | |
175 | /* Subscripts of this data reference. */ |
176 | struct indices indices; |
177 | |
178 | /* Alternate subscripts initialized lazily and used by data-dependence |
179 | analysis only when the main indices of two DRs are not comparable. |
180 | Keep last to keep vec_info_shared::check_datarefs happy. */ |
181 | struct indices alt_indices; |
182 | }; |
183 | |
184 | #define DR_STMT(DR) (DR)->stmt |
185 | #define DR_REF(DR) (DR)->ref |
186 | #define DR_BASE_OBJECT(DR) (DR)->indices.base_object |
187 | #define DR_UNCONSTRAINED_BASE(DR) (DR)->indices.unconstrained_base |
188 | #define DR_ACCESS_FNS(DR) (DR)->indices.access_fns |
189 | #define DR_ACCESS_FN(DR, I) DR_ACCESS_FNS (DR)[I] |
190 | #define DR_NUM_DIMENSIONS(DR) DR_ACCESS_FNS (DR).length () |
191 | #define DR_IS_READ(DR) (DR)->is_read |
192 | #define DR_IS_WRITE(DR) (!DR_IS_READ (DR)) |
193 | #define DR_IS_CONDITIONAL_IN_STMT(DR) (DR)->is_conditional_in_stmt |
194 | #define DR_BASE_ADDRESS(DR) (DR)->innermost.base_address |
195 | #define DR_OFFSET(DR) (DR)->innermost.offset |
196 | #define DR_INIT(DR) (DR)->innermost.init |
197 | #define DR_STEP(DR) (DR)->innermost.step |
198 | #define DR_PTR_INFO(DR) (DR)->alias.ptr_info |
199 | #define DR_BASE_ALIGNMENT(DR) (DR)->innermost.base_alignment |
200 | #define DR_BASE_MISALIGNMENT(DR) (DR)->innermost.base_misalignment |
201 | #define DR_OFFSET_ALIGNMENT(DR) (DR)->innermost.offset_alignment |
202 | #define DR_STEP_ALIGNMENT(DR) (DR)->innermost.step_alignment |
203 | #define DR_INNERMOST(DR) (DR)->innermost |
204 | |
205 | typedef struct data_reference *data_reference_p; |
206 | |
207 | /* This struct is used to store the information of a data reference, |
208 | including the data ref itself and the segment length for aliasing |
209 | checks. This is used to merge alias checks. */ |
210 | |
211 | class dr_with_seg_len |
212 | { |
213 | public: |
214 | dr_with_seg_len (data_reference_p d, tree len, unsigned HOST_WIDE_INT size, |
215 | unsigned int a) |
216 | : dr (d), seg_len (len), access_size (size), align (a) {} |
217 | |
218 | data_reference_p dr; |
219 | /* The offset of the last access that needs to be checked minus |
220 | the offset of the first. */ |
221 | tree seg_len; |
222 | /* A value that, when added to abs (SEG_LEN), gives the total number of |
223 | bytes in the segment. */ |
224 | poly_uint64 access_size; |
225 | /* The minimum common alignment of DR's start address, SEG_LEN and |
226 | ACCESS_SIZE. */ |
227 | unsigned int align; |
228 | }; |
229 | |
230 | /* Flags that describe a potential alias between two dr_with_seg_lens. |
231 | In general, each pair of dr_with_seg_lens represents a composite of |
232 | multiple access pairs P, so testing flags like DR_IS_READ on the DRs |
233 | does not give meaningful information. |
234 | |
235 | DR_ALIAS_RAW: |
236 | There is a pair in P for which the second reference is a read |
237 | and the first is a write. |
238 | |
239 | DR_ALIAS_WAR: |
240 | There is a pair in P for which the second reference is a write |
241 | and the first is a read. |
242 | |
243 | DR_ALIAS_WAW: |
244 | There is a pair in P for which both references are writes. |
245 | |
246 | DR_ALIAS_ARBITRARY: |
247 | Either |
248 | (a) it isn't possible to classify one pair in P as RAW, WAW or WAR; or |
249 | (b) there is a pair in P that breaks the ordering assumption below. |
250 | |
251 | This flag overrides the RAW, WAR and WAW flags above. |
252 | |
253 | DR_ALIAS_UNSWAPPED: |
254 | DR_ALIAS_SWAPPED: |
255 | Temporary flags that indicate whether there is a pair P whose |
256 | DRs have or haven't been swapped around. |
257 | |
258 | DR_ALIAS_MIXED_STEPS: |
259 | The DR_STEP for one of the data references in the pair does not |
260 | accurately describe that reference for all members of P. (Note |
261 | that the flag does not say anything about whether the DR_STEPs |
262 | of the two references in the pair are the same.) |
263 | |
264 | The ordering assumption mentioned above is that for every pair |
265 | (DR_A, DR_B) in P: |
266 | |
267 | (1) The original code accesses n elements for DR_A and n elements for DR_B, |
268 | interleaved as follows: |
269 | |
270 | one access of size DR_A.access_size at DR_A.dr |
271 | one access of size DR_B.access_size at DR_B.dr |
272 | one access of size DR_A.access_size at DR_A.dr + STEP_A |
273 | one access of size DR_B.access_size at DR_B.dr + STEP_B |
274 | one access of size DR_A.access_size at DR_A.dr + STEP_A * 2 |
275 | one access of size DR_B.access_size at DR_B.dr + STEP_B * 2 |
276 | ... |
277 | |
278 | (2) The new code accesses the same data in exactly two chunks: |
279 | |
280 | one group of accesses spanning |DR_A.seg_len| + DR_A.access_size |
281 | one group of accesses spanning |DR_B.seg_len| + DR_B.access_size |
282 | |
283 | A pair might break this assumption if the DR_A and DR_B accesses |
284 | in the original or the new code are mingled in some way. For example, |
285 | if DR_A.access_size represents the effect of two individual writes |
286 | to nearby locations, the pair breaks the assumption if those writes |
287 | occur either side of the access for DR_B. |
288 | |
289 | Note that DR_ALIAS_ARBITRARY describes whether the ordering assumption |
290 | fails to hold for any individual pair in P. If the assumption *does* |
291 | hold for every pair in P, it doesn't matter whether it holds for the |
292 | composite pair or not. In other words, P should represent the complete |
293 | set of pairs that the composite pair is testing, so only the ordering |
294 | of two accesses in the same member of P matters. */ |
295 | const unsigned int DR_ALIAS_RAW = 1U << 0; |
296 | const unsigned int DR_ALIAS_WAR = 1U << 1; |
297 | const unsigned int DR_ALIAS_WAW = 1U << 2; |
298 | const unsigned int DR_ALIAS_ARBITRARY = 1U << 3; |
299 | const unsigned int DR_ALIAS_SWAPPED = 1U << 4; |
300 | const unsigned int DR_ALIAS_UNSWAPPED = 1U << 5; |
301 | const unsigned int DR_ALIAS_MIXED_STEPS = 1U << 6; |
302 | |
303 | /* This struct contains two dr_with_seg_len objects with aliasing data |
304 | refs. Two comparisons are generated from them. */ |
305 | |
306 | class dr_with_seg_len_pair_t |
307 | { |
308 | public: |
309 | /* WELL_ORDERED indicates that the ordering assumption described above |
310 | DR_ALIAS_ARBITRARY holds. REORDERED indicates that it doesn't. */ |
311 | enum sequencing { WELL_ORDERED, REORDERED }; |
312 | |
313 | dr_with_seg_len_pair_t (const dr_with_seg_len &, |
314 | const dr_with_seg_len &, sequencing); |
315 | |
316 | dr_with_seg_len first; |
317 | dr_with_seg_len second; |
318 | unsigned int flags; |
319 | }; |
320 | |
321 | inline dr_with_seg_len_pair_t:: |
322 | dr_with_seg_len_pair_t (const dr_with_seg_len &d1, const dr_with_seg_len &d2, |
323 | sequencing seq) |
324 | : first (d1), second (d2), flags (0) |
325 | { |
326 | if (DR_IS_READ (d1.dr) && DR_IS_WRITE (d2.dr)) |
327 | flags |= DR_ALIAS_WAR; |
328 | else if (DR_IS_WRITE (d1.dr) && DR_IS_READ (d2.dr)) |
329 | flags |= DR_ALIAS_RAW; |
330 | else if (DR_IS_WRITE (d1.dr) && DR_IS_WRITE (d2.dr)) |
331 | flags |= DR_ALIAS_WAW; |
332 | else |
333 | gcc_unreachable (); |
334 | if (seq == REORDERED) |
335 | flags |= DR_ALIAS_ARBITRARY; |
336 | } |
337 | |
338 | enum data_dependence_direction { |
339 | dir_positive, |
340 | dir_negative, |
341 | dir_equal, |
342 | dir_positive_or_negative, |
343 | dir_positive_or_equal, |
344 | dir_negative_or_equal, |
345 | dir_star, |
346 | dir_independent |
347 | }; |
348 | |
349 | /* The description of the grid of iterations that overlap. At most |
350 | two loops are considered at the same time just now, hence at most |
351 | two functions are needed. For each of the functions, we store |
352 | the vector of coefficients, f[0] + x * f[1] + y * f[2] + ..., |
353 | where x, y, ... are variables. */ |
354 | |
355 | #define MAX_DIM 2 |
356 | |
357 | /* Special values of N. */ |
358 | #define NO_DEPENDENCE 0 |
359 | #define NOT_KNOWN (MAX_DIM + 1) |
360 | #define CF_NONTRIVIAL_P(CF) ((CF)->n != NO_DEPENDENCE && (CF)->n != NOT_KNOWN) |
361 | #define CF_NOT_KNOWN_P(CF) ((CF)->n == NOT_KNOWN) |
362 | #define CF_NO_DEPENDENCE_P(CF) ((CF)->n == NO_DEPENDENCE) |
363 | |
364 | typedef vec<tree> affine_fn; |
365 | |
366 | struct conflict_function |
367 | { |
368 | unsigned n; |
369 | affine_fn fns[MAX_DIM]; |
370 | }; |
371 | |
372 | /* What is a subscript? Given two array accesses a subscript is the |
373 | tuple composed of the access functions for a given dimension. |
374 | Example: Given A[f1][f2][f3] and B[g1][g2][g3], there are three |
375 | subscripts: (f1, g1), (f2, g2), (f3, g3). These three subscripts |
376 | are stored in the data_dependence_relation structure under the form |
377 | of an array of subscripts. */ |
378 | |
379 | struct subscript |
380 | { |
381 | /* The access functions of the two references. */ |
382 | tree access_fn[2]; |
383 | |
384 | /* A description of the iterations for which the elements are |
385 | accessed twice. */ |
386 | conflict_function *conflicting_iterations_in_a; |
387 | conflict_function *conflicting_iterations_in_b; |
388 | |
389 | /* This field stores the information about the iteration domain |
390 | validity of the dependence relation. */ |
391 | tree last_conflict; |
392 | |
393 | /* Distance from the iteration that access a conflicting element in |
394 | A to the iteration that access this same conflicting element in |
395 | B. The distance is a tree scalar expression, i.e. a constant or a |
396 | symbolic expression, but certainly not a chrec function. */ |
397 | tree distance; |
398 | }; |
399 | |
400 | typedef struct subscript *subscript_p; |
401 | |
402 | #define SUB_ACCESS_FN(SUB, I) (SUB)->access_fn[I] |
403 | #define SUB_CONFLICTS_IN_A(SUB) (SUB)->conflicting_iterations_in_a |
404 | #define SUB_CONFLICTS_IN_B(SUB) (SUB)->conflicting_iterations_in_b |
405 | #define SUB_LAST_CONFLICT(SUB) (SUB)->last_conflict |
406 | #define SUB_DISTANCE(SUB) (SUB)->distance |
407 | |
408 | /* A data_dependence_relation represents a relation between two |
409 | data_references A and B. */ |
410 | |
411 | struct data_dependence_relation |
412 | { |
413 | |
414 | struct data_reference *a; |
415 | struct data_reference *b; |
416 | |
417 | /* A "yes/no/maybe" field for the dependence relation: |
418 | |
419 | - when "ARE_DEPENDENT == NULL_TREE", there exist a dependence |
420 | relation between A and B, and the description of this relation |
421 | is given in the SUBSCRIPTS array, |
422 | |
423 | - when "ARE_DEPENDENT == chrec_known", there is no dependence and |
424 | SUBSCRIPTS is empty, |
425 | |
426 | - when "ARE_DEPENDENT == chrec_dont_know", there may be a dependence, |
427 | but the analyzer cannot be more specific. */ |
428 | tree are_dependent; |
429 | |
430 | /* If nonnull, COULD_BE_INDEPENDENT_P is true and the accesses are |
431 | independent when the runtime addresses of OBJECT_A and OBJECT_B |
432 | are different. The addresses of both objects are invariant in the |
433 | loop nest. */ |
434 | tree object_a; |
435 | tree object_b; |
436 | |
437 | /* For each subscript in the dependence test, there is an element in |
438 | this array. This is the attribute that labels the edge A->B of |
439 | the data_dependence_relation. */ |
440 | vec<subscript_p> subscripts; |
441 | |
442 | /* The analyzed loop nest. */ |
443 | vec<loop_p> loop_nest; |
444 | |
445 | /* The classic direction vector. */ |
446 | vec<lambda_vector> dir_vects; |
447 | |
448 | /* The classic distance vector. */ |
449 | vec<lambda_vector> dist_vects; |
450 | |
451 | /* Is the dependence reversed with respect to the lexicographic order? */ |
452 | bool reversed_p; |
453 | |
454 | /* When the dependence relation is affine, it can be represented by |
455 | a distance vector. */ |
456 | bool affine_p; |
457 | |
458 | /* Set to true when the dependence relation is on the same data |
459 | access. */ |
460 | bool self_reference_p; |
461 | |
462 | /* True if the dependence described is conservatively correct rather |
463 | than exact, and if it is still possible for the accesses to be |
464 | conditionally independent. For example, the a and b references in: |
465 | |
466 | struct s *a, *b; |
467 | for (int i = 0; i < n; ++i) |
468 | a->f[i] += b->f[i]; |
469 | |
470 | conservatively have a distance vector of (0), for the case in which |
471 | a == b, but the accesses are independent if a != b. Similarly, |
472 | the a and b references in: |
473 | |
474 | struct s *a, *b; |
475 | for (int i = 0; i < n; ++i) |
476 | a[0].f[i] += b[i].f[i]; |
477 | |
478 | conservatively have a distance vector of (0), but they are indepenent |
479 | when a != b + i. In contrast, the references in: |
480 | |
481 | struct s *a; |
482 | for (int i = 0; i < n; ++i) |
483 | a->f[i] += a->f[i]; |
484 | |
485 | have the same distance vector of (0), but the accesses can never be |
486 | independent. */ |
487 | bool could_be_independent_p; |
488 | }; |
489 | |
490 | typedef struct data_dependence_relation *ddr_p; |
491 | |
492 | #define DDR_A(DDR) (DDR)->a |
493 | #define DDR_B(DDR) (DDR)->b |
494 | #define DDR_AFFINE_P(DDR) (DDR)->affine_p |
495 | #define DDR_ARE_DEPENDENT(DDR) (DDR)->are_dependent |
496 | #define DDR_OBJECT_A(DDR) (DDR)->object_a |
497 | #define DDR_OBJECT_B(DDR) (DDR)->object_b |
498 | #define DDR_SUBSCRIPTS(DDR) (DDR)->subscripts |
499 | #define DDR_SUBSCRIPT(DDR, I) DDR_SUBSCRIPTS (DDR)[I] |
500 | #define DDR_NUM_SUBSCRIPTS(DDR) DDR_SUBSCRIPTS (DDR).length () |
501 | |
502 | #define DDR_LOOP_NEST(DDR) (DDR)->loop_nest |
503 | /* The size of the direction/distance vectors: the number of loops in |
504 | the loop nest. */ |
505 | #define DDR_NB_LOOPS(DDR) (DDR_LOOP_NEST (DDR).length ()) |
506 | #define DDR_SELF_REFERENCE(DDR) (DDR)->self_reference_p |
507 | |
508 | #define DDR_DIST_VECTS(DDR) ((DDR)->dist_vects) |
509 | #define DDR_DIR_VECTS(DDR) ((DDR)->dir_vects) |
510 | #define DDR_NUM_DIST_VECTS(DDR) \ |
511 | (DDR_DIST_VECTS (DDR).length ()) |
512 | #define DDR_NUM_DIR_VECTS(DDR) \ |
513 | (DDR_DIR_VECTS (DDR).length ()) |
514 | #define DDR_DIR_VECT(DDR, I) \ |
515 | DDR_DIR_VECTS (DDR)[I] |
516 | #define DDR_DIST_VECT(DDR, I) \ |
517 | DDR_DIST_VECTS (DDR)[I] |
518 | #define DDR_REVERSED_P(DDR) (DDR)->reversed_p |
519 | #define DDR_COULD_BE_INDEPENDENT_P(DDR) (DDR)->could_be_independent_p |
520 | |
521 | |
522 | opt_result dr_analyze_innermost (innermost_loop_behavior *, tree, |
523 | class loop *, const gimple *); |
524 | extern bool compute_data_dependences_for_loop (class loop *, bool, |
525 | vec<loop_p> *, |
526 | vec<data_reference_p> *, |
527 | vec<ddr_p> *); |
528 | extern void debug_ddrs (vec<ddr_p> ); |
529 | extern void dump_data_reference (FILE *, struct data_reference *); |
530 | extern void debug (data_reference &ref); |
531 | extern void debug (data_reference *ptr); |
532 | extern void debug_data_reference (struct data_reference *); |
533 | extern void debug_data_references (vec<data_reference_p> ); |
534 | extern void debug (vec<data_reference_p> &ref); |
535 | extern void debug (vec<data_reference_p> *ptr); |
536 | extern void debug_data_dependence_relation (const data_dependence_relation *); |
537 | extern void dump_data_dependence_relations (FILE *, const vec<ddr_p> &); |
538 | extern void debug (vec<ddr_p> &ref); |
539 | extern void debug (vec<ddr_p> *ptr); |
540 | extern void debug_data_dependence_relations (vec<ddr_p> ); |
541 | extern void free_dependence_relation (struct data_dependence_relation *); |
542 | extern void free_dependence_relations (vec<ddr_p>& ); |
543 | extern void free_data_ref (data_reference_p); |
544 | extern void free_data_refs (vec<data_reference_p>& ); |
545 | extern opt_result find_data_references_in_stmt (class loop *, gimple *, |
546 | vec<data_reference_p> *); |
547 | extern bool graphite_find_data_references_in_stmt (edge, loop_p, gimple *, |
548 | vec<data_reference_p> *); |
549 | tree find_data_references_in_loop (class loop *, vec<data_reference_p> *); |
550 | bool loop_nest_has_data_refs (loop_p loop); |
551 | struct data_reference *create_data_ref (edge, loop_p, tree, gimple *, bool, |
552 | bool); |
553 | extern bool find_loop_nest (class loop *, vec<loop_p> *); |
554 | extern struct data_dependence_relation *initialize_data_dependence_relation |
555 | (struct data_reference *, struct data_reference *, vec<loop_p>); |
556 | extern void compute_affine_dependence (struct data_dependence_relation *, |
557 | loop_p); |
558 | extern void compute_self_dependence (struct data_dependence_relation *); |
559 | extern bool compute_all_dependences (const vec<data_reference_p> &, |
560 | vec<ddr_p> *, |
561 | const vec<loop_p> &, bool); |
562 | extern tree find_data_references_in_bb (class loop *, basic_block, |
563 | vec<data_reference_p> *); |
564 | extern unsigned int dr_alignment (innermost_loop_behavior *); |
565 | extern tree get_base_for_alignment (tree, unsigned int *); |
566 | |
567 | /* Return the alignment in bytes that DR is guaranteed to have at all |
568 | times. */ |
569 | |
570 | inline unsigned int |
571 | dr_alignment (data_reference *dr) |
572 | { |
573 | return dr_alignment (&DR_INNERMOST (dr)); |
574 | } |
575 | |
576 | extern bool dr_may_alias_p (const struct data_reference *, |
577 | const struct data_reference *, class loop *); |
578 | extern bool dr_equal_offsets_p (struct data_reference *, |
579 | struct data_reference *); |
580 | |
581 | extern opt_result runtime_alias_check_p (ddr_p, class loop *, bool); |
582 | extern int data_ref_compare_tree (tree, tree); |
583 | extern void prune_runtime_alias_test_list (vec<dr_with_seg_len_pair_t> *, |
584 | poly_uint64); |
585 | extern void create_runtime_alias_checks (class loop *, |
586 | const vec<dr_with_seg_len_pair_t> *, |
587 | tree*); |
588 | extern tree dr_direction_indicator (struct data_reference *); |
589 | extern tree dr_zero_step_indicator (struct data_reference *); |
590 | extern bool dr_known_forward_stride_p (struct data_reference *); |
591 | |
592 | /* Return true when the base objects of data references A and B are |
593 | the same memory object. */ |
594 | |
595 | inline bool |
596 | same_data_refs_base_objects (data_reference_p a, data_reference_p b) |
597 | { |
598 | return DR_NUM_DIMENSIONS (a) == DR_NUM_DIMENSIONS (b) |
599 | && operand_equal_p (DR_BASE_OBJECT (a), DR_BASE_OBJECT (b), flags: 0); |
600 | } |
601 | |
602 | /* Return true when the data references A and B are accessing the same |
603 | memory object with the same access functions. Optionally skip the |
604 | last OFFSET dimensions in the data reference. */ |
605 | |
606 | inline bool |
607 | same_data_refs (data_reference_p a, data_reference_p b, int offset = 0) |
608 | { |
609 | unsigned int i; |
610 | |
611 | /* The references are exactly the same. */ |
612 | if (operand_equal_p (DR_REF (a), DR_REF (b), flags: 0)) |
613 | return true; |
614 | |
615 | if (!same_data_refs_base_objects (a, b)) |
616 | return false; |
617 | |
618 | for (i = offset; i < DR_NUM_DIMENSIONS (a); i++) |
619 | if (!eq_evolutions_p (DR_ACCESS_FN (a, i), DR_ACCESS_FN (b, i))) |
620 | return false; |
621 | |
622 | return true; |
623 | } |
624 | |
625 | /* Returns true when all the dependences are computable. */ |
626 | |
627 | inline bool |
628 | known_dependences_p (vec<ddr_p> dependence_relations) |
629 | { |
630 | ddr_p ddr; |
631 | unsigned int i; |
632 | |
633 | FOR_EACH_VEC_ELT (dependence_relations, i, ddr) |
634 | if (DDR_ARE_DEPENDENT (ddr) == chrec_dont_know) |
635 | return false; |
636 | |
637 | return true; |
638 | } |
639 | |
640 | /* Returns the dependence level for a vector DIST of size LENGTH. |
641 | LEVEL = 0 means a lexicographic dependence, i.e. a dependence due |
642 | to the sequence of statements, not carried by any loop. */ |
643 | |
644 | inline unsigned |
645 | dependence_level (lambda_vector dist_vect, int length) |
646 | { |
647 | int i; |
648 | |
649 | for (i = 0; i < length; i++) |
650 | if (dist_vect[i] != 0) |
651 | return i + 1; |
652 | |
653 | return 0; |
654 | } |
655 | |
656 | /* Return the dependence level for the DDR relation. */ |
657 | |
658 | inline unsigned |
659 | ddr_dependence_level (ddr_p ddr) |
660 | { |
661 | unsigned vector; |
662 | unsigned level = 0; |
663 | |
664 | if (DDR_DIST_VECTS (ddr).exists ()) |
665 | level = dependence_level (DDR_DIST_VECT (ddr, 0), DDR_NB_LOOPS (ddr)); |
666 | |
667 | for (vector = 1; vector < DDR_NUM_DIST_VECTS (ddr); vector++) |
668 | level = MIN (level, dependence_level (DDR_DIST_VECT (ddr, vector), |
669 | DDR_NB_LOOPS (ddr))); |
670 | return level; |
671 | } |
672 | |
673 | /* Return the index of the variable VAR in the LOOP_NEST array. */ |
674 | |
675 | inline int |
676 | index_in_loop_nest (int var, const vec<loop_p> &loop_nest) |
677 | { |
678 | class loop *loopi; |
679 | int var_index; |
680 | |
681 | for (var_index = 0; loop_nest.iterate (ix: var_index, ptr: &loopi); var_index++) |
682 | if (loopi->num == var) |
683 | return var_index; |
684 | |
685 | gcc_unreachable (); |
686 | } |
687 | |
688 | /* Returns true when the data reference DR the form "A[i] = ..." |
689 | with a stride equal to its unit type size. */ |
690 | |
691 | inline bool |
692 | adjacent_dr_p (struct data_reference *dr) |
693 | { |
694 | /* If this is a bitfield store bail out. */ |
695 | if (TREE_CODE (DR_REF (dr)) == COMPONENT_REF |
696 | && DECL_BIT_FIELD (TREE_OPERAND (DR_REF (dr), 1))) |
697 | return false; |
698 | |
699 | if (!DR_STEP (dr) |
700 | || TREE_CODE (DR_STEP (dr)) != INTEGER_CST) |
701 | return false; |
702 | |
703 | return tree_int_cst_equal (fold_unary (ABS_EXPR, TREE_TYPE (DR_STEP (dr)), |
704 | DR_STEP (dr)), |
705 | TYPE_SIZE_UNIT (TREE_TYPE (DR_REF (dr)))); |
706 | } |
707 | |
708 | void split_constant_offset (tree , tree *, tree *); |
709 | |
710 | /* Compute the greatest common divisor of a VECTOR of SIZE numbers. */ |
711 | |
712 | inline lambda_int |
713 | lambda_vector_gcd (lambda_vector vector, int size) |
714 | { |
715 | int i; |
716 | lambda_int gcd1 = 0; |
717 | |
718 | if (size > 0) |
719 | { |
720 | gcd1 = vector[0]; |
721 | for (i = 1; i < size; i++) |
722 | gcd1 = gcd (gcd1, vector[i]); |
723 | } |
724 | return gcd1; |
725 | } |
726 | |
727 | /* Allocate a new vector of given SIZE. */ |
728 | |
729 | inline lambda_vector |
730 | lambda_vector_new (int size) |
731 | { |
732 | /* ??? We shouldn't abuse the GC allocator here. */ |
733 | return ggc_cleared_vec_alloc<lambda_int> (c: size); |
734 | } |
735 | |
736 | /* Clear out vector VEC1 of length SIZE. */ |
737 | |
738 | inline void |
739 | lambda_vector_clear (lambda_vector vec1, int size) |
740 | { |
741 | memset (s: vec1, c: 0, n: size * sizeof (*vec1)); |
742 | } |
743 | |
744 | /* Returns true when the vector V is lexicographically positive, in |
745 | other words, when the first nonzero element is positive. */ |
746 | |
747 | inline bool |
748 | lambda_vector_lexico_pos (lambda_vector v, |
749 | unsigned n) |
750 | { |
751 | unsigned i; |
752 | for (i = 0; i < n; i++) |
753 | { |
754 | if (v[i] == 0) |
755 | continue; |
756 | if (v[i] < 0) |
757 | return false; |
758 | if (v[i] > 0) |
759 | return true; |
760 | } |
761 | return true; |
762 | } |
763 | |
764 | /* Return true if vector VEC1 of length SIZE is the zero vector. */ |
765 | |
766 | inline bool |
767 | lambda_vector_zerop (lambda_vector vec1, int size) |
768 | { |
769 | int i; |
770 | for (i = 0; i < size; i++) |
771 | if (vec1[i] != 0) |
772 | return false; |
773 | return true; |
774 | } |
775 | |
776 | /* Allocate a matrix of M rows x N cols. */ |
777 | |
778 | inline lambda_matrix |
779 | lambda_matrix_new (int m, int n, struct obstack *lambda_obstack) |
780 | { |
781 | lambda_matrix mat; |
782 | int i; |
783 | |
784 | mat = XOBNEWVEC (lambda_obstack, lambda_vector, m); |
785 | |
786 | for (i = 0; i < m; i++) |
787 | mat[i] = XOBNEWVEC (lambda_obstack, lambda_int, n); |
788 | |
789 | return mat; |
790 | } |
791 | |
792 | #endif /* GCC_TREE_DATA_REF_H */ |
793 | |