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b8698a0f | 1 | /* Data references and dependences detectors. |
8d9254fc | 2 | Copyright (C) 2003-2020 Free Software Foundation, Inc. |
0ff4040e | 3 | Contributed by Sebastian Pop <pop@cri.ensmp.fr> |
56cf8686 SP |
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 | |
9dcd6f09 | 9 | Software Foundation; either version 3, or (at your option) any later |
56cf8686 SP |
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 | |
9dcd6f09 NC |
18 | along with GCC; see the file COPYING3. If not see |
19 | <http://www.gnu.org/licenses/>. */ | |
56cf8686 SP |
20 | |
21 | #ifndef GCC_TREE_DATA_REF_H | |
22 | #define GCC_TREE_DATA_REF_H | |
23 | ||
3a796c6f | 24 | #include "graphds.h" |
dea61d92 | 25 | #include "tree-chrec.h" |
f4ebbd24 | 26 | #include "opt-problem.h" |
36d59cf7 | 27 | |
98b44b0e | 28 | /* |
3cb960c7 ZD |
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 | |
b8698a0f L |
33 | constant offset (INIT). Examples, in loop nest |
34 | ||
3cb960c7 ZD |
35 | for (i = 0; i < 100; i++) |
36 | for (j = 3; j < 100; j++) | |
98b44b0e | 37 | |
86a07404 | 38 | Example 1 Example 2 |
3cb960c7 | 39 | data-ref a[j].b[i][j] *(p + x + 16B + 4B * j) |
b8698a0f | 40 | |
dea61d92 | 41 | |
3cb960c7 ZD |
42 | innermost_loop_behavior |
43 | base_address &a p | |
44 | offset i * D_i x | |
45 | init 3 * D_j + offsetof (b) 28 | |
86a07404 | 46 | step D_j 4 |
86a07404 | 47 | |
98b44b0e | 48 | */ |
3cb960c7 | 49 | struct innermost_loop_behavior |
86a07404 IR |
50 | { |
51 | tree base_address; | |
52 | tree offset; | |
53 | tree init; | |
54 | tree step; | |
3cb960c7 | 55 | |
bb642979 RS |
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 | ||
e054a185 RS |
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; | |
832b4117 RS |
96 | |
97 | /* Likewise for STEP. */ | |
98 | unsigned int step_alignment; | |
86a07404 IR |
99 | }; |
100 | ||
3cb960c7 | 101 | /* Describes the evolutions of indices of the memory reference. The indices |
c4ddde1b RG |
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) | |
3cb960c7 | 111 | indices: {j_0, +, 1}_2 {16, +, 4}_2 |
c4ddde1b | 112 | 4 |
3cb960c7 ZD |
113 | {i_0, +, 1}_1 |
114 | {j_0, +, 1}_2 | |
115 | */ | |
116 | ||
117 | struct indices | |
86a07404 IR |
118 | { |
119 | /* The object. */ | |
120 | tree base_object; | |
b8698a0f | 121 | |
3cb960c7 | 122 | /* A list of chrecs. Access functions of the indices. */ |
9771b263 | 123 | vec<tree> access_fns; |
f3ae4add RB |
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; | |
86a07404 IR |
128 | }; |
129 | ||
3cb960c7 ZD |
130 | struct dr_alias |
131 | { | |
132 | /* The alias information that should be used for new pointers to this | |
c4ddde1b | 133 | location. */ |
3cb960c7 | 134 | struct ptr_info_def *ptr_info; |
86a07404 IR |
135 | }; |
136 | ||
b305e3da SP |
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. */ | |
1c8badf6 RB |
141 | typedef HOST_WIDE_INT lambda_int; |
142 | typedef lambda_int *lambda_vector; | |
b305e3da SP |
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 | ||
9f275479 | 148 | |
9f275479 | 149 | |
36d59cf7 | 150 | struct data_reference |
56cf8686 | 151 | { |
56cf8686 | 152 | /* A pointer to the statement that contains this DR. */ |
355fe088 | 153 | gimple *stmt; |
b8698a0f | 154 | |
3cb960c7 | 155 | /* A pointer to the memory reference. */ |
56cf8686 SP |
156 | tree ref; |
157 | ||
56cf8686 | 158 | /* Auxiliary info specific to a pass. */ |
5417e022 | 159 | void *aux; |
56cf8686 SP |
160 | |
161 | /* True when the data reference is in RHS of a stmt. */ | |
162 | bool is_read; | |
163 | ||
62c8a2cf RS |
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 | ||
3cb960c7 ZD |
169 | /* Behavior of the memory reference in the innermost loop. */ |
170 | struct innermost_loop_behavior innermost; | |
86a07404 | 171 | |
f8bf9252 | 172 | /* Subscripts of this data reference. */ |
3cb960c7 | 173 | struct indices indices; |
86a07404 | 174 | |
3cb960c7 ZD |
175 | /* Alias information for the data reference. */ |
176 | struct dr_alias alias; | |
9f275479 | 177 | }; |
ebf78a47 | 178 | |
86a07404 IR |
179 | #define DR_STMT(DR) (DR)->stmt |
180 | #define DR_REF(DR) (DR)->ref | |
3cb960c7 | 181 | #define DR_BASE_OBJECT(DR) (DR)->indices.base_object |
f3ae4add | 182 | #define DR_UNCONSTRAINED_BASE(DR) (DR)->indices.unconstrained_base |
3cb960c7 | 183 | #define DR_ACCESS_FNS(DR) (DR)->indices.access_fns |
9771b263 DN |
184 | #define DR_ACCESS_FN(DR, I) DR_ACCESS_FNS (DR)[I] |
185 | #define DR_NUM_DIMENSIONS(DR) DR_ACCESS_FNS (DR).length () | |
86a07404 | 186 | #define DR_IS_READ(DR) (DR)->is_read |
b0af49c4 | 187 | #define DR_IS_WRITE(DR) (!DR_IS_READ (DR)) |
62c8a2cf | 188 | #define DR_IS_CONDITIONAL_IN_STMT(DR) (DR)->is_conditional_in_stmt |
3cb960c7 ZD |
189 | #define DR_BASE_ADDRESS(DR) (DR)->innermost.base_address |
190 | #define DR_OFFSET(DR) (DR)->innermost.offset | |
191 | #define DR_INIT(DR) (DR)->innermost.init | |
192 | #define DR_STEP(DR) (DR)->innermost.step | |
3cb960c7 | 193 | #define DR_PTR_INFO(DR) (DR)->alias.ptr_info |
bb642979 RS |
194 | #define DR_BASE_ALIGNMENT(DR) (DR)->innermost.base_alignment |
195 | #define DR_BASE_MISALIGNMENT(DR) (DR)->innermost.base_misalignment | |
e054a185 | 196 | #define DR_OFFSET_ALIGNMENT(DR) (DR)->innermost.offset_alignment |
832b4117 | 197 | #define DR_STEP_ALIGNMENT(DR) (DR)->innermost.step_alignment |
fad08d12 | 198 | #define DR_INNERMOST(DR) (DR)->innermost |
9f275479 JS |
199 | |
200 | typedef struct data_reference *data_reference_p; | |
56cf8686 | 201 | |
8d44cf72 BC |
202 | /* This struct is used to store the information of a data reference, |
203 | including the data ref itself and the segment length for aliasing | |
204 | checks. This is used to merge alias checks. */ | |
205 | ||
6c1dae73 | 206 | class dr_with_seg_len |
8d44cf72 | 207 | { |
6c1dae73 | 208 | public: |
a57776a1 RS |
209 | dr_with_seg_len (data_reference_p d, tree len, unsigned HOST_WIDE_INT size, |
210 | unsigned int a) | |
211 | : dr (d), seg_len (len), access_size (size), align (a) {} | |
8d44cf72 BC |
212 | |
213 | data_reference_p dr; | |
a57776a1 RS |
214 | /* The offset of the last access that needs to be checked minus |
215 | the offset of the first. */ | |
8d44cf72 | 216 | tree seg_len; |
a57776a1 RS |
217 | /* A value that, when added to abs (SEG_LEN), gives the total number of |
218 | bytes in the segment. */ | |
219 | poly_uint64 access_size; | |
220 | /* The minimum common alignment of DR's start address, SEG_LEN and | |
221 | ACCESS_SIZE. */ | |
222 | unsigned int align; | |
8d44cf72 BC |
223 | }; |
224 | ||
e9acf80c RS |
225 | /* Flags that describe a potential alias between two dr_with_seg_lens. |
226 | In general, each pair of dr_with_seg_lens represents a composite of | |
227 | multiple access pairs P, so testing flags like DR_IS_READ on the DRs | |
228 | does not give meaningful information. | |
229 | ||
230 | DR_ALIAS_RAW: | |
231 | There is a pair in P for which the second reference is a read | |
232 | and the first is a write. | |
233 | ||
234 | DR_ALIAS_WAR: | |
235 | There is a pair in P for which the second reference is a write | |
236 | and the first is a read. | |
237 | ||
238 | DR_ALIAS_WAW: | |
239 | There is a pair in P for which both references are writes. | |
240 | ||
241 | DR_ALIAS_ARBITRARY: | |
242 | Either | |
243 | (a) it isn't possible to classify one pair in P as RAW, WAW or WAR; or | |
244 | (b) there is a pair in P that breaks the ordering assumption below. | |
245 | ||
246 | This flag overrides the RAW, WAR and WAW flags above. | |
247 | ||
248 | DR_ALIAS_UNSWAPPED: | |
249 | DR_ALIAS_SWAPPED: | |
250 | Temporary flags that indicate whether there is a pair P whose | |
251 | DRs have or haven't been swapped around. | |
252 | ||
52c29905 RS |
253 | DR_ALIAS_MIXED_STEPS: |
254 | The DR_STEP for one of the data references in the pair does not | |
255 | accurately describe that reference for all members of P. (Note | |
256 | that the flag does not say anything about whether the DR_STEPs | |
257 | of the two references in the pair are the same.) | |
258 | ||
e9acf80c RS |
259 | The ordering assumption mentioned above is that for every pair |
260 | (DR_A, DR_B) in P: | |
261 | ||
262 | (1) The original code accesses n elements for DR_A and n elements for DR_B, | |
263 | interleaved as follows: | |
264 | ||
265 | one access of size DR_A.access_size at DR_A.dr | |
266 | one access of size DR_B.access_size at DR_B.dr | |
267 | one access of size DR_A.access_size at DR_A.dr + STEP_A | |
268 | one access of size DR_B.access_size at DR_B.dr + STEP_B | |
269 | one access of size DR_A.access_size at DR_A.dr + STEP_A * 2 | |
270 | one access of size DR_B.access_size at DR_B.dr + STEP_B * 2 | |
271 | ... | |
272 | ||
273 | (2) The new code accesses the same data in exactly two chunks: | |
274 | ||
275 | one group of accesses spanning |DR_A.seg_len| + DR_A.access_size | |
276 | one group of accesses spanning |DR_B.seg_len| + DR_B.access_size | |
277 | ||
278 | A pair might break this assumption if the DR_A and DR_B accesses | |
279 | in the original or the new code are mingled in some way. For example, | |
280 | if DR_A.access_size represents the effect of two individual writes | |
281 | to nearby locations, the pair breaks the assumption if those writes | |
282 | occur either side of the access for DR_B. | |
283 | ||
284 | Note that DR_ALIAS_ARBITRARY describes whether the ordering assumption | |
285 | fails to hold for any individual pair in P. If the assumption *does* | |
286 | hold for every pair in P, it doesn't matter whether it holds for the | |
287 | composite pair or not. In other words, P should represent the complete | |
288 | set of pairs that the composite pair is testing, so only the ordering | |
289 | of two accesses in the same member of P matters. */ | |
290 | const unsigned int DR_ALIAS_RAW = 1U << 0; | |
291 | const unsigned int DR_ALIAS_WAR = 1U << 1; | |
292 | const unsigned int DR_ALIAS_WAW = 1U << 2; | |
293 | const unsigned int DR_ALIAS_ARBITRARY = 1U << 3; | |
294 | const unsigned int DR_ALIAS_SWAPPED = 1U << 4; | |
295 | const unsigned int DR_ALIAS_UNSWAPPED = 1U << 5; | |
52c29905 | 296 | const unsigned int DR_ALIAS_MIXED_STEPS = 1U << 6; |
e9acf80c | 297 | |
8d44cf72 BC |
298 | /* This struct contains two dr_with_seg_len objects with aliasing data |
299 | refs. Two comparisons are generated from them. */ | |
300 | ||
6c1dae73 | 301 | class dr_with_seg_len_pair_t |
8d44cf72 | 302 | { |
6c1dae73 | 303 | public: |
e9acf80c RS |
304 | /* WELL_ORDERED indicates that the ordering assumption described above |
305 | DR_ALIAS_ARBITRARY holds. REORDERED indicates that it doesn't. */ | |
306 | enum sequencing { WELL_ORDERED, REORDERED }; | |
307 | ||
308 | dr_with_seg_len_pair_t (const dr_with_seg_len &, | |
309 | const dr_with_seg_len &, sequencing); | |
8d44cf72 BC |
310 | |
311 | dr_with_seg_len first; | |
312 | dr_with_seg_len second; | |
e9acf80c | 313 | unsigned int flags; |
8d44cf72 BC |
314 | }; |
315 | ||
e9acf80c RS |
316 | inline dr_with_seg_len_pair_t:: |
317 | dr_with_seg_len_pair_t (const dr_with_seg_len &d1, const dr_with_seg_len &d2, | |
318 | sequencing seq) | |
319 | : first (d1), second (d2), flags (0) | |
320 | { | |
321 | if (DR_IS_READ (d1.dr) && DR_IS_WRITE (d2.dr)) | |
322 | flags |= DR_ALIAS_WAR; | |
323 | else if (DR_IS_WRITE (d1.dr) && DR_IS_READ (d2.dr)) | |
324 | flags |= DR_ALIAS_RAW; | |
325 | else if (DR_IS_WRITE (d1.dr) && DR_IS_WRITE (d2.dr)) | |
326 | flags |= DR_ALIAS_WAW; | |
327 | else | |
328 | gcc_unreachable (); | |
329 | if (seq == REORDERED) | |
330 | flags |= DR_ALIAS_ARBITRARY; | |
331 | } | |
332 | ||
56cf8686 | 333 | enum data_dependence_direction { |
b8698a0f L |
334 | dir_positive, |
335 | dir_negative, | |
336 | dir_equal, | |
56cf8686 SP |
337 | dir_positive_or_negative, |
338 | dir_positive_or_equal, | |
339 | dir_negative_or_equal, | |
340 | dir_star, | |
341 | dir_independent | |
342 | }; | |
343 | ||
d93817c4 ZD |
344 | /* The description of the grid of iterations that overlap. At most |
345 | two loops are considered at the same time just now, hence at most | |
346 | two functions are needed. For each of the functions, we store | |
347 | the vector of coefficients, f[0] + x * f[1] + y * f[2] + ..., | |
348 | where x, y, ... are variables. */ | |
349 | ||
350 | #define MAX_DIM 2 | |
351 | ||
352 | /* Special values of N. */ | |
353 | #define NO_DEPENDENCE 0 | |
354 | #define NOT_KNOWN (MAX_DIM + 1) | |
355 | #define CF_NONTRIVIAL_P(CF) ((CF)->n != NO_DEPENDENCE && (CF)->n != NOT_KNOWN) | |
356 | #define CF_NOT_KNOWN_P(CF) ((CF)->n == NOT_KNOWN) | |
357 | #define CF_NO_DEPENDENCE_P(CF) ((CF)->n == NO_DEPENDENCE) | |
358 | ||
9771b263 | 359 | typedef vec<tree> affine_fn; |
d93817c4 | 360 | |
84562394 | 361 | struct conflict_function |
d93817c4 ZD |
362 | { |
363 | unsigned n; | |
364 | affine_fn fns[MAX_DIM]; | |
84562394 | 365 | }; |
d93817c4 | 366 | |
56cf8686 SP |
367 | /* What is a subscript? Given two array accesses a subscript is the |
368 | tuple composed of the access functions for a given dimension. | |
369 | Example: Given A[f1][f2][f3] and B[g1][g2][g3], there are three | |
370 | subscripts: (f1, g1), (f2, g2), (f3, g3). These three subscripts | |
371 | are stored in the data_dependence_relation structure under the form | |
372 | of an array of subscripts. */ | |
373 | ||
36d59cf7 | 374 | struct subscript |
56cf8686 | 375 | { |
dfbddbeb RS |
376 | /* The access functions of the two references. */ |
377 | tree access_fn[2]; | |
378 | ||
56cf8686 SP |
379 | /* A description of the iterations for which the elements are |
380 | accessed twice. */ | |
d93817c4 ZD |
381 | conflict_function *conflicting_iterations_in_a; |
382 | conflict_function *conflicting_iterations_in_b; | |
b8698a0f | 383 | |
86df10e3 | 384 | /* This field stores the information about the iteration domain |
56cf8686 | 385 | validity of the dependence relation. */ |
86df10e3 | 386 | tree last_conflict; |
b8698a0f | 387 | |
56cf8686 SP |
388 | /* Distance from the iteration that access a conflicting element in |
389 | A to the iteration that access this same conflicting element in | |
89dbed81 | 390 | B. The distance is a tree scalar expression, i.e. a constant or a |
56cf8686 SP |
391 | symbolic expression, but certainly not a chrec function. */ |
392 | tree distance; | |
56cf8686 SP |
393 | }; |
394 | ||
ebf78a47 | 395 | typedef struct subscript *subscript_p; |
ebf78a47 | 396 | |
dfbddbeb | 397 | #define SUB_ACCESS_FN(SUB, I) (SUB)->access_fn[I] |
45d93414 RS |
398 | #define SUB_CONFLICTS_IN_A(SUB) (SUB)->conflicting_iterations_in_a |
399 | #define SUB_CONFLICTS_IN_B(SUB) (SUB)->conflicting_iterations_in_b | |
400 | #define SUB_LAST_CONFLICT(SUB) (SUB)->last_conflict | |
401 | #define SUB_DISTANCE(SUB) (SUB)->distance | |
56cf8686 SP |
402 | |
403 | /* A data_dependence_relation represents a relation between two | |
404 | data_references A and B. */ | |
405 | ||
36d59cf7 | 406 | struct data_dependence_relation |
56cf8686 | 407 | { |
b8698a0f | 408 | |
56cf8686 SP |
409 | struct data_reference *a; |
410 | struct data_reference *b; | |
411 | ||
412 | /* A "yes/no/maybe" field for the dependence relation: | |
b8698a0f | 413 | |
56cf8686 SP |
414 | - when "ARE_DEPENDENT == NULL_TREE", there exist a dependence |
415 | relation between A and B, and the description of this relation | |
416 | is given in the SUBSCRIPTS array, | |
b8698a0f | 417 | |
56cf8686 SP |
418 | - when "ARE_DEPENDENT == chrec_known", there is no dependence and |
419 | SUBSCRIPTS is empty, | |
b8698a0f | 420 | |
56cf8686 SP |
421 | - when "ARE_DEPENDENT == chrec_dont_know", there may be a dependence, |
422 | but the analyzer cannot be more specific. */ | |
423 | tree are_dependent; | |
b8698a0f | 424 | |
9adee305 RS |
425 | /* If nonnull, COULD_BE_INDEPENDENT_P is true and the accesses are |
426 | independent when the runtime addresses of OBJECT_A and OBJECT_B | |
427 | are different. The addresses of both objects are invariant in the | |
428 | loop nest. */ | |
429 | tree object_a; | |
430 | tree object_b; | |
431 | ||
56cf8686 SP |
432 | /* For each subscript in the dependence test, there is an element in |
433 | this array. This is the attribute that labels the edge A->B of | |
434 | the data_dependence_relation. */ | |
9771b263 | 435 | vec<subscript_p> subscripts; |
36d59cf7 | 436 | |
ba42e045 | 437 | /* The analyzed loop nest. */ |
9771b263 | 438 | vec<loop_p> loop_nest; |
86df10e3 | 439 | |
36d59cf7 | 440 | /* The classic direction vector. */ |
9771b263 | 441 | vec<lambda_vector> dir_vects; |
36d59cf7 DB |
442 | |
443 | /* The classic distance vector. */ | |
9771b263 | 444 | vec<lambda_vector> dist_vects; |
71d5b5e1 SP |
445 | |
446 | /* Is the dependence reversed with respect to the lexicographic order? */ | |
447 | bool reversed_p; | |
8f5929e1 JJ |
448 | |
449 | /* When the dependence relation is affine, it can be represented by | |
450 | a distance vector. */ | |
451 | bool affine_p; | |
452 | ||
453 | /* Set to true when the dependence relation is on the same data | |
454 | access. */ | |
455 | bool self_reference_p; | |
dfbddbeb RS |
456 | |
457 | /* True if the dependence described is conservatively correct rather | |
458 | than exact, and if it is still possible for the accesses to be | |
459 | conditionally independent. For example, the a and b references in: | |
460 | ||
461 | struct s *a, *b; | |
462 | for (int i = 0; i < n; ++i) | |
463 | a->f[i] += b->f[i]; | |
464 | ||
465 | conservatively have a distance vector of (0), for the case in which | |
466 | a == b, but the accesses are independent if a != b. Similarly, | |
467 | the a and b references in: | |
468 | ||
469 | struct s *a, *b; | |
470 | for (int i = 0; i < n; ++i) | |
471 | a[0].f[i] += b[i].f[i]; | |
472 | ||
473 | conservatively have a distance vector of (0), but they are indepenent | |
474 | when a != b + i. In contrast, the references in: | |
475 | ||
476 | struct s *a; | |
477 | for (int i = 0; i < n; ++i) | |
478 | a->f[i] += a->f[i]; | |
479 | ||
480 | have the same distance vector of (0), but the accesses can never be | |
481 | independent. */ | |
482 | bool could_be_independent_p; | |
56cf8686 SP |
483 | }; |
484 | ||
0ff4040e | 485 | typedef struct data_dependence_relation *ddr_p; |
0ff4040e | 486 | |
45d93414 RS |
487 | #define DDR_A(DDR) (DDR)->a |
488 | #define DDR_B(DDR) (DDR)->b | |
489 | #define DDR_AFFINE_P(DDR) (DDR)->affine_p | |
490 | #define DDR_ARE_DEPENDENT(DDR) (DDR)->are_dependent | |
9adee305 RS |
491 | #define DDR_OBJECT_A(DDR) (DDR)->object_a |
492 | #define DDR_OBJECT_B(DDR) (DDR)->object_b | |
45d93414 | 493 | #define DDR_SUBSCRIPTS(DDR) (DDR)->subscripts |
9771b263 DN |
494 | #define DDR_SUBSCRIPT(DDR, I) DDR_SUBSCRIPTS (DDR)[I] |
495 | #define DDR_NUM_SUBSCRIPTS(DDR) DDR_SUBSCRIPTS (DDR).length () | |
ba42e045 | 496 | |
45d93414 | 497 | #define DDR_LOOP_NEST(DDR) (DDR)->loop_nest |
ba42e045 SP |
498 | /* The size of the direction/distance vectors: the number of loops in |
499 | the loop nest. */ | |
9771b263 | 500 | #define DDR_NB_LOOPS(DDR) (DDR_LOOP_NEST (DDR).length ()) |
45d93414 | 501 | #define DDR_SELF_REFERENCE(DDR) (DDR)->self_reference_p |
304afda6 SP |
502 | |
503 | #define DDR_DIST_VECTS(DDR) ((DDR)->dist_vects) | |
504 | #define DDR_DIR_VECTS(DDR) ((DDR)->dir_vects) | |
505 | #define DDR_NUM_DIST_VECTS(DDR) \ | |
9771b263 | 506 | (DDR_DIST_VECTS (DDR).length ()) |
304afda6 | 507 | #define DDR_NUM_DIR_VECTS(DDR) \ |
9771b263 | 508 | (DDR_DIR_VECTS (DDR).length ()) |
304afda6 | 509 | #define DDR_DIR_VECT(DDR, I) \ |
9771b263 | 510 | DDR_DIR_VECTS (DDR)[I] |
304afda6 | 511 | #define DDR_DIST_VECT(DDR, I) \ |
9771b263 | 512 | DDR_DIST_VECTS (DDR)[I] |
45d93414 | 513 | #define DDR_REVERSED_P(DDR) (DDR)->reversed_p |
dfbddbeb | 514 | #define DDR_COULD_BE_INDEPENDENT_P(DDR) (DDR)->could_be_independent_p |
56cf8686 SP |
515 | |
516 | \f | |
f4ebbd24 | 517 | opt_result dr_analyze_innermost (innermost_loop_behavior *, tree, |
99b1c316 MS |
518 | class loop *, const gimple *); |
519 | extern bool compute_data_dependences_for_loop (class loop *, bool, | |
9771b263 DN |
520 | vec<loop_p> *, |
521 | vec<data_reference_p> *, | |
522 | vec<ddr_p> *); | |
9771b263 | 523 | extern void debug_ddrs (vec<ddr_p> ); |
56cf8686 | 524 | extern void dump_data_reference (FILE *, struct data_reference *); |
7b3b6ae4 LC |
525 | extern void debug (data_reference &ref); |
526 | extern void debug (data_reference *ptr); | |
a37d995a | 527 | extern void debug_data_reference (struct data_reference *); |
9771b263 | 528 | extern void debug_data_references (vec<data_reference_p> ); |
7b3b6ae4 LC |
529 | extern void debug (vec<data_reference_p> &ref); |
530 | extern void debug (vec<data_reference_p> *ptr); | |
ba42e045 | 531 | extern void debug_data_dependence_relation (struct data_dependence_relation *); |
9771b263 | 532 | extern void dump_data_dependence_relations (FILE *, vec<ddr_p> ); |
7b3b6ae4 LC |
533 | extern void debug (vec<ddr_p> &ref); |
534 | extern void debug (vec<ddr_p> *ptr); | |
9771b263 | 535 | extern void debug_data_dependence_relations (vec<ddr_p> ); |
36d59cf7 | 536 | extern void free_dependence_relation (struct data_dependence_relation *); |
9771b263 | 537 | extern void free_dependence_relations (vec<ddr_p> ); |
dea61d92 | 538 | extern void free_data_ref (data_reference_p); |
9771b263 | 539 | extern void free_data_refs (vec<data_reference_p> ); |
99b1c316 | 540 | extern opt_result find_data_references_in_stmt (class loop *, gimple *, |
f4ebbd24 | 541 | vec<data_reference_p> *); |
a68f286c | 542 | extern bool graphite_find_data_references_in_stmt (edge, loop_p, gimple *, |
9771b263 | 543 | vec<data_reference_p> *); |
99b1c316 | 544 | tree find_data_references_in_loop (class loop *, vec<data_reference_p> *); |
74032f47 | 545 | bool loop_nest_has_data_refs (loop_p loop); |
a68f286c | 546 | struct data_reference *create_data_ref (edge, loop_p, tree, gimple *, bool, |
62c8a2cf | 547 | bool); |
99b1c316 | 548 | extern bool find_loop_nest (class loop *, vec<loop_p> *); |
aec7ae7d | 549 | extern struct data_dependence_relation *initialize_data_dependence_relation |
9771b263 | 550 | (struct data_reference *, struct data_reference *, vec<loop_p>); |
f20132e7 RG |
551 | extern void compute_affine_dependence (struct data_dependence_relation *, |
552 | loop_p); | |
aec7ae7d | 553 | extern void compute_self_dependence (struct data_dependence_relation *); |
9771b263 DN |
554 | extern bool compute_all_dependences (vec<data_reference_p> , |
555 | vec<ddr_p> *, | |
556 | vec<loop_p>, bool); | |
99b1c316 | 557 | extern tree find_data_references_in_bb (class loop *, basic_block, |
9771b263 | 558 | vec<data_reference_p> *); |
25f68d90 | 559 | extern unsigned int dr_alignment (innermost_loop_behavior *); |
a199d5e7 | 560 | extern tree get_base_for_alignment (tree, unsigned int *); |
25f68d90 RS |
561 | |
562 | /* Return the alignment in bytes that DR is guaranteed to have at all | |
563 | times. */ | |
564 | ||
565 | inline unsigned int | |
566 | dr_alignment (data_reference *dr) | |
567 | { | |
568 | return dr_alignment (&DR_INNERMOST (dr)); | |
569 | } | |
f8bf9252 | 570 | |
f8bf9252 | 571 | extern bool dr_may_alias_p (const struct data_reference *, |
99b1c316 | 572 | const struct data_reference *, class loop *); |
bfe068c3 IR |
573 | extern bool dr_equal_offsets_p (struct data_reference *, |
574 | struct data_reference *); | |
e1fd038a | 575 | |
99b1c316 | 576 | extern opt_result runtime_alias_check_p (ddr_p, class loop *, bool); |
2c8f03ad | 577 | extern int data_ref_compare_tree (tree, tree); |
8d44cf72 | 578 | extern void prune_runtime_alias_test_list (vec<dr_with_seg_len_pair_t> *, |
079b4a9c | 579 | poly_uint64); |
99b1c316 | 580 | extern void create_runtime_alias_checks (class loop *, |
9cbd2d97 | 581 | vec<dr_with_seg_len_pair_t> *, tree*); |
a57776a1 RS |
582 | extern tree dr_direction_indicator (struct data_reference *); |
583 | extern tree dr_zero_step_indicator (struct data_reference *); | |
584 | extern bool dr_known_forward_stride_p (struct data_reference *); | |
585 | ||
e1fd038a SP |
586 | /* Return true when the base objects of data references A and B are |
587 | the same memory object. */ | |
588 | ||
589 | static inline bool | |
590 | same_data_refs_base_objects (data_reference_p a, data_reference_p b) | |
591 | { | |
592 | return DR_NUM_DIMENSIONS (a) == DR_NUM_DIMENSIONS (b) | |
593 | && operand_equal_p (DR_BASE_OBJECT (a), DR_BASE_OBJECT (b), 0); | |
594 | } | |
595 | ||
596 | /* Return true when the data references A and B are accessing the same | |
597 | memory object with the same access functions. */ | |
598 | ||
599 | static inline bool | |
600 | same_data_refs (data_reference_p a, data_reference_p b) | |
601 | { | |
602 | unsigned int i; | |
603 | ||
604 | /* The references are exactly the same. */ | |
605 | if (operand_equal_p (DR_REF (a), DR_REF (b), 0)) | |
606 | return true; | |
607 | ||
608 | if (!same_data_refs_base_objects (a, b)) | |
609 | return false; | |
610 | ||
611 | for (i = 0; i < DR_NUM_DIMENSIONS (a); i++) | |
612 | if (!eq_evolutions_p (DR_ACCESS_FN (a, i), DR_ACCESS_FN (b, i))) | |
613 | return false; | |
614 | ||
615 | return true; | |
616 | } | |
617 | ||
2fd5894f RB |
618 | /* Returns true when all the dependences are computable. */ |
619 | ||
620 | inline bool | |
621 | known_dependences_p (vec<ddr_p> dependence_relations) | |
622 | { | |
623 | ddr_p ddr; | |
624 | unsigned int i; | |
625 | ||
626 | FOR_EACH_VEC_ELT (dependence_relations, i, ddr) | |
627 | if (DDR_ARE_DEPENDENT (ddr) == chrec_dont_know) | |
628 | return false; | |
629 | ||
630 | return true; | |
631 | } | |
632 | ||
b305e3da SP |
633 | /* Returns the dependence level for a vector DIST of size LENGTH. |
634 | LEVEL = 0 means a lexicographic dependence, i.e. a dependence due | |
635 | to the sequence of statements, not carried by any loop. */ | |
636 | ||
637 | static inline unsigned | |
638 | dependence_level (lambda_vector dist_vect, int length) | |
639 | { | |
640 | int i; | |
641 | ||
642 | for (i = 0; i < length; i++) | |
643 | if (dist_vect[i] != 0) | |
644 | return i + 1; | |
645 | ||
646 | return 0; | |
647 | } | |
648 | ||
dea61d92 SP |
649 | /* Return the dependence level for the DDR relation. */ |
650 | ||
651 | static inline unsigned | |
652 | ddr_dependence_level (ddr_p ddr) | |
653 | { | |
654 | unsigned vector; | |
655 | unsigned level = 0; | |
656 | ||
9771b263 | 657 | if (DDR_DIST_VECTS (ddr).exists ()) |
dea61d92 SP |
658 | level = dependence_level (DDR_DIST_VECT (ddr, 0), DDR_NB_LOOPS (ddr)); |
659 | ||
660 | for (vector = 1; vector < DDR_NUM_DIST_VECTS (ddr); vector++) | |
661 | level = MIN (level, dependence_level (DDR_DIST_VECT (ddr, vector), | |
662 | DDR_NB_LOOPS (ddr))); | |
663 | return level; | |
664 | } | |
665 | ||
ba42e045 SP |
666 | /* Return the index of the variable VAR in the LOOP_NEST array. */ |
667 | ||
668 | static inline int | |
9771b263 | 669 | index_in_loop_nest (int var, vec<loop_p> loop_nest) |
ba42e045 | 670 | { |
99b1c316 | 671 | class loop *loopi; |
ba42e045 SP |
672 | int var_index; |
673 | ||
d6366157 | 674 | for (var_index = 0; loop_nest.iterate (var_index, &loopi); var_index++) |
ba42e045 | 675 | if (loopi->num == var) |
d6366157 | 676 | return var_index; |
ba42e045 | 677 | |
d6366157 | 678 | gcc_unreachable (); |
ba42e045 SP |
679 | } |
680 | ||
be6b029b RG |
681 | /* Returns true when the data reference DR the form "A[i] = ..." |
682 | with a stride equal to its unit type size. */ | |
5e37ea0e SP |
683 | |
684 | static inline bool | |
d0582dc1 | 685 | adjacent_dr_p (struct data_reference *dr) |
5e37ea0e | 686 | { |
be6b029b RG |
687 | /* If this is a bitfield store bail out. */ |
688 | if (TREE_CODE (DR_REF (dr)) == COMPONENT_REF | |
689 | && DECL_BIT_FIELD (TREE_OPERAND (DR_REF (dr), 1))) | |
690 | return false; | |
691 | ||
692 | if (!DR_STEP (dr) | |
693 | || TREE_CODE (DR_STEP (dr)) != INTEGER_CST) | |
694 | return false; | |
695 | ||
696 | return tree_int_cst_equal (fold_unary (ABS_EXPR, TREE_TYPE (DR_STEP (dr)), | |
697 | DR_STEP (dr)), | |
698 | TYPE_SIZE_UNIT (TREE_TYPE (DR_REF (dr)))); | |
5e37ea0e SP |
699 | } |
700 | ||
468c2ac0 DN |
701 | void split_constant_offset (tree , tree *, tree *); |
702 | ||
b305e3da SP |
703 | /* Compute the greatest common divisor of a VECTOR of SIZE numbers. */ |
704 | ||
1c8badf6 | 705 | static inline lambda_int |
b305e3da SP |
706 | lambda_vector_gcd (lambda_vector vector, int size) |
707 | { | |
708 | int i; | |
1c8badf6 | 709 | lambda_int gcd1 = 0; |
b305e3da SP |
710 | |
711 | if (size > 0) | |
712 | { | |
713 | gcd1 = vector[0]; | |
714 | for (i = 1; i < size; i++) | |
715 | gcd1 = gcd (gcd1, vector[i]); | |
716 | } | |
717 | return gcd1; | |
718 | } | |
719 | ||
720 | /* Allocate a new vector of given SIZE. */ | |
721 | ||
722 | static inline lambda_vector | |
723 | lambda_vector_new (int size) | |
724 | { | |
6f4f1a50 | 725 | /* ??? We shouldn't abuse the GC allocator here. */ |
1c8badf6 | 726 | return ggc_cleared_vec_alloc<lambda_int> (size); |
b305e3da SP |
727 | } |
728 | ||
729 | /* Clear out vector VEC1 of length SIZE. */ | |
730 | ||
731 | static inline void | |
732 | lambda_vector_clear (lambda_vector vec1, int size) | |
733 | { | |
734 | memset (vec1, 0, size * sizeof (*vec1)); | |
735 | } | |
736 | ||
737 | /* Returns true when the vector V is lexicographically positive, in | |
738 | other words, when the first nonzero element is positive. */ | |
739 | ||
740 | static inline bool | |
741 | lambda_vector_lexico_pos (lambda_vector v, | |
742 | unsigned n) | |
743 | { | |
744 | unsigned i; | |
745 | for (i = 0; i < n; i++) | |
746 | { | |
747 | if (v[i] == 0) | |
748 | continue; | |
749 | if (v[i] < 0) | |
750 | return false; | |
751 | if (v[i] > 0) | |
752 | return true; | |
753 | } | |
754 | return true; | |
755 | } | |
756 | ||
757 | /* Return true if vector VEC1 of length SIZE is the zero vector. */ | |
758 | ||
759 | static inline bool | |
760 | lambda_vector_zerop (lambda_vector vec1, int size) | |
761 | { | |
762 | int i; | |
763 | for (i = 0; i < size; i++) | |
764 | if (vec1[i] != 0) | |
765 | return false; | |
766 | return true; | |
767 | } | |
768 | ||
769 | /* Allocate a matrix of M rows x N cols. */ | |
770 | ||
771 | static inline lambda_matrix | |
772 | lambda_matrix_new (int m, int n, struct obstack *lambda_obstack) | |
773 | { | |
774 | lambda_matrix mat; | |
775 | int i; | |
776 | ||
6f4f1a50 | 777 | mat = XOBNEWVEC (lambda_obstack, lambda_vector, m); |
b305e3da SP |
778 | |
779 | for (i = 0; i < m; i++) | |
1c8badf6 | 780 | mat[i] = XOBNEWVEC (lambda_obstack, lambda_int, n); |
b305e3da SP |
781 | |
782 | return mat; | |
783 | } | |
784 | ||
56cf8686 | 785 | #endif /* GCC_TREE_DATA_REF_H */ |