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56cf8686 | 1 | /* Data references and dependences detectors. |
06e1d03d | 2 | Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 |
66647d44 | 3 | Free Software Foundation, Inc. |
0ff4040e | 4 | Contributed by Sebastian Pop <pop@cri.ensmp.fr> |
56cf8686 SP |
5 | |
6 | This file is part of GCC. | |
7 | ||
8 | GCC is free software; you can redistribute it and/or modify it under | |
9 | the terms of the GNU General Public License as published by the Free | |
9dcd6f09 | 10 | Software Foundation; either version 3, or (at your option) any later |
56cf8686 SP |
11 | version. |
12 | ||
13 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
14 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
15 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
16 | for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
9dcd6f09 NC |
19 | along with GCC; see the file COPYING3. If not see |
20 | <http://www.gnu.org/licenses/>. */ | |
56cf8686 SP |
21 | |
22 | /* This pass walks a given loop structure searching for array | |
23 | references. The information about the array accesses is recorded | |
b8698a0f L |
24 | in DATA_REFERENCE structures. |
25 | ||
26 | The basic test for determining the dependences is: | |
27 | given two access functions chrec1 and chrec2 to a same array, and | |
28 | x and y two vectors from the iteration domain, the same element of | |
56cf8686 SP |
29 | the array is accessed twice at iterations x and y if and only if: |
30 | | chrec1 (x) == chrec2 (y). | |
b8698a0f | 31 | |
56cf8686 | 32 | The goals of this analysis are: |
b8698a0f | 33 | |
56cf8686 SP |
34 | - to determine the independence: the relation between two |
35 | independent accesses is qualified with the chrec_known (this | |
36 | information allows a loop parallelization), | |
b8698a0f | 37 | |
56cf8686 SP |
38 | - when two data references access the same data, to qualify the |
39 | dependence relation with classic dependence representations: | |
b8698a0f | 40 | |
56cf8686 SP |
41 | - distance vectors |
42 | - direction vectors | |
43 | - loop carried level dependence | |
44 | - polyhedron dependence | |
45 | or with the chains of recurrences based representation, | |
b8698a0f L |
46 | |
47 | - to define a knowledge base for storing the data dependence | |
56cf8686 | 48 | information, |
b8698a0f | 49 | |
56cf8686 | 50 | - to define an interface to access this data. |
b8698a0f L |
51 | |
52 | ||
56cf8686 | 53 | Definitions: |
b8698a0f | 54 | |
56cf8686 SP |
55 | - subscript: given two array accesses a subscript is the tuple |
56 | composed of the access functions for a given dimension. Example: | |
57 | Given A[f1][f2][f3] and B[g1][g2][g3], there are three subscripts: | |
58 | (f1, g1), (f2, g2), (f3, g3). | |
59 | ||
60 | - Diophantine equation: an equation whose coefficients and | |
b8698a0f | 61 | solutions are integer constants, for example the equation |
56cf8686 SP |
62 | | 3*x + 2*y = 1 |
63 | has an integer solution x = 1 and y = -1. | |
b8698a0f | 64 | |
56cf8686 | 65 | References: |
b8698a0f | 66 | |
56cf8686 SP |
67 | - "Advanced Compilation for High Performance Computing" by Randy |
68 | Allen and Ken Kennedy. | |
b8698a0f L |
69 | http://citeseer.ist.psu.edu/goff91practical.html |
70 | ||
71 | - "Loop Transformations for Restructuring Compilers - The Foundations" | |
56cf8686 SP |
72 | by Utpal Banerjee. |
73 | ||
b8698a0f | 74 | |
56cf8686 SP |
75 | */ |
76 | ||
77 | #include "config.h" | |
78 | #include "system.h" | |
79 | #include "coretypes.h" | |
cf835838 | 80 | #include "gimple-pretty-print.h" |
56cf8686 | 81 | #include "tree-flow.h" |
56cf8686 | 82 | #include "cfgloop.h" |
56cf8686 SP |
83 | #include "tree-data-ref.h" |
84 | #include "tree-scalar-evolution.h" | |
85 | #include "tree-pass.h" | |
946e1bc7 | 86 | #include "langhooks.h" |
02f5d6c5 | 87 | #include "tree-affine.h" |
3881dee9 | 88 | #include "params.h" |
56cf8686 | 89 | |
0ff4040e SP |
90 | static struct datadep_stats |
91 | { | |
92 | int num_dependence_tests; | |
93 | int num_dependence_dependent; | |
94 | int num_dependence_independent; | |
95 | int num_dependence_undetermined; | |
96 | ||
97 | int num_subscript_tests; | |
98 | int num_subscript_undetermined; | |
99 | int num_same_subscript_function; | |
100 | ||
101 | int num_ziv; | |
102 | int num_ziv_independent; | |
103 | int num_ziv_dependent; | |
104 | int num_ziv_unimplemented; | |
105 | ||
106 | int num_siv; | |
107 | int num_siv_independent; | |
108 | int num_siv_dependent; | |
109 | int num_siv_unimplemented; | |
110 | ||
111 | int num_miv; | |
112 | int num_miv_independent; | |
113 | int num_miv_dependent; | |
114 | int num_miv_unimplemented; | |
115 | } dependence_stats; | |
116 | ||
ba42e045 SP |
117 | static bool subscript_dependence_tester_1 (struct data_dependence_relation *, |
118 | struct data_reference *, | |
da9a21f4 SP |
119 | struct data_reference *, |
120 | struct loop *); | |
56cf8686 SP |
121 | /* Returns true iff A divides B. */ |
122 | ||
b8698a0f | 123 | static inline bool |
ed7a4b4b | 124 | tree_fold_divides_p (const_tree a, const_tree b) |
56cf8686 | 125 | { |
b73a6056 RS |
126 | gcc_assert (TREE_CODE (a) == INTEGER_CST); |
127 | gcc_assert (TREE_CODE (b) == INTEGER_CST); | |
d35936ab | 128 | return integer_zerop (int_const_binop (TRUNC_MOD_EXPR, b, a)); |
56cf8686 SP |
129 | } |
130 | ||
86df10e3 SP |
131 | /* Returns true iff A divides B. */ |
132 | ||
b8698a0f | 133 | static inline bool |
86df10e3 SP |
134 | int_divides_p (int a, int b) |
135 | { | |
136 | return ((b % a) == 0); | |
56cf8686 SP |
137 | } |
138 | ||
139 | \f | |
140 | ||
b8698a0f | 141 | /* Dump into FILE all the data references from DATAREFS. */ |
56cf8686 | 142 | |
aeb83f09 | 143 | static void |
ebf78a47 | 144 | dump_data_references (FILE *file, VEC (data_reference_p, heap) *datarefs) |
56cf8686 SP |
145 | { |
146 | unsigned int i; | |
ebf78a47 SP |
147 | struct data_reference *dr; |
148 | ||
ac47786e | 149 | FOR_EACH_VEC_ELT (data_reference_p, datarefs, i, dr) |
ebf78a47 | 150 | dump_data_reference (file, dr); |
56cf8686 SP |
151 | } |
152 | ||
b8698a0f | 153 | /* Dump into STDERR all the data references from DATAREFS. */ |
a37d995a | 154 | |
24e47c76 | 155 | DEBUG_FUNCTION void |
a37d995a SP |
156 | debug_data_references (VEC (data_reference_p, heap) *datarefs) |
157 | { | |
158 | dump_data_references (stderr, datarefs); | |
159 | } | |
160 | ||
a37d995a SP |
161 | /* Print to STDERR the data_reference DR. */ |
162 | ||
24e47c76 | 163 | DEBUG_FUNCTION void |
a37d995a SP |
164 | debug_data_reference (struct data_reference *dr) |
165 | { | |
166 | dump_data_reference (stderr, dr); | |
167 | } | |
168 | ||
56cf8686 SP |
169 | /* Dump function for a DATA_REFERENCE structure. */ |
170 | ||
b8698a0f L |
171 | void |
172 | dump_data_reference (FILE *outf, | |
56cf8686 SP |
173 | struct data_reference *dr) |
174 | { | |
175 | unsigned int i; | |
b8698a0f | 176 | |
28c5db57 SP |
177 | fprintf (outf, "#(Data Ref: \n"); |
178 | fprintf (outf, "# bb: %d \n", gimple_bb (DR_STMT (dr))->index); | |
179 | fprintf (outf, "# stmt: "); | |
726a989a | 180 | print_gimple_stmt (outf, DR_STMT (dr), 0, 0); |
03922af3 | 181 | fprintf (outf, "# ref: "); |
56cf8686 | 182 | print_generic_stmt (outf, DR_REF (dr), 0); |
03922af3 | 183 | fprintf (outf, "# base_object: "); |
86a07404 | 184 | print_generic_stmt (outf, DR_BASE_OBJECT (dr), 0); |
b8698a0f | 185 | |
56cf8686 SP |
186 | for (i = 0; i < DR_NUM_DIMENSIONS (dr); i++) |
187 | { | |
03922af3 | 188 | fprintf (outf, "# Access function %d: ", i); |
56cf8686 SP |
189 | print_generic_stmt (outf, DR_ACCESS_FN (dr, i), 0); |
190 | } | |
03922af3 | 191 | fprintf (outf, "#)\n"); |
56cf8686 SP |
192 | } |
193 | ||
d93817c4 ZD |
194 | /* Dumps the affine function described by FN to the file OUTF. */ |
195 | ||
196 | static void | |
197 | dump_affine_function (FILE *outf, affine_fn fn) | |
198 | { | |
199 | unsigned i; | |
200 | tree coef; | |
201 | ||
202 | print_generic_expr (outf, VEC_index (tree, fn, 0), TDF_SLIM); | |
203 | for (i = 1; VEC_iterate (tree, fn, i, coef); i++) | |
204 | { | |
205 | fprintf (outf, " + "); | |
206 | print_generic_expr (outf, coef, TDF_SLIM); | |
207 | fprintf (outf, " * x_%u", i); | |
208 | } | |
209 | } | |
210 | ||
211 | /* Dumps the conflict function CF to the file OUTF. */ | |
212 | ||
213 | static void | |
214 | dump_conflict_function (FILE *outf, conflict_function *cf) | |
215 | { | |
216 | unsigned i; | |
217 | ||
218 | if (cf->n == NO_DEPENDENCE) | |
219 | fprintf (outf, "no dependence\n"); | |
220 | else if (cf->n == NOT_KNOWN) | |
221 | fprintf (outf, "not known\n"); | |
222 | else | |
223 | { | |
224 | for (i = 0; i < cf->n; i++) | |
225 | { | |
226 | fprintf (outf, "["); | |
227 | dump_affine_function (outf, cf->fns[i]); | |
228 | fprintf (outf, "]\n"); | |
229 | } | |
230 | } | |
231 | } | |
232 | ||
86df10e3 SP |
233 | /* Dump function for a SUBSCRIPT structure. */ |
234 | ||
aeb83f09 | 235 | static void |
86df10e3 SP |
236 | dump_subscript (FILE *outf, struct subscript *subscript) |
237 | { | |
d93817c4 | 238 | conflict_function *cf = SUB_CONFLICTS_IN_A (subscript); |
86df10e3 SP |
239 | |
240 | fprintf (outf, "\n (subscript \n"); | |
241 | fprintf (outf, " iterations_that_access_an_element_twice_in_A: "); | |
d93817c4 ZD |
242 | dump_conflict_function (outf, cf); |
243 | if (CF_NONTRIVIAL_P (cf)) | |
86df10e3 SP |
244 | { |
245 | tree last_iteration = SUB_LAST_CONFLICT (subscript); | |
246 | fprintf (outf, " last_conflict: "); | |
247 | print_generic_stmt (outf, last_iteration, 0); | |
248 | } | |
b8698a0f | 249 | |
d93817c4 | 250 | cf = SUB_CONFLICTS_IN_B (subscript); |
86df10e3 | 251 | fprintf (outf, " iterations_that_access_an_element_twice_in_B: "); |
d93817c4 ZD |
252 | dump_conflict_function (outf, cf); |
253 | if (CF_NONTRIVIAL_P (cf)) | |
86df10e3 SP |
254 | { |
255 | tree last_iteration = SUB_LAST_CONFLICT (subscript); | |
256 | fprintf (outf, " last_conflict: "); | |
257 | print_generic_stmt (outf, last_iteration, 0); | |
258 | } | |
259 | ||
260 | fprintf (outf, " (Subscript distance: "); | |
261 | print_generic_stmt (outf, SUB_DISTANCE (subscript), 0); | |
262 | fprintf (outf, " )\n"); | |
263 | fprintf (outf, " )\n"); | |
264 | } | |
265 | ||
0ff4040e SP |
266 | /* Print the classic direction vector DIRV to OUTF. */ |
267 | ||
aeb83f09 | 268 | static void |
0ff4040e SP |
269 | print_direction_vector (FILE *outf, |
270 | lambda_vector dirv, | |
271 | int length) | |
272 | { | |
273 | int eq; | |
274 | ||
275 | for (eq = 0; eq < length; eq++) | |
276 | { | |
81f40b79 ILT |
277 | enum data_dependence_direction dir = ((enum data_dependence_direction) |
278 | dirv[eq]); | |
0ff4040e SP |
279 | |
280 | switch (dir) | |
281 | { | |
282 | case dir_positive: | |
283 | fprintf (outf, " +"); | |
284 | break; | |
285 | case dir_negative: | |
286 | fprintf (outf, " -"); | |
287 | break; | |
288 | case dir_equal: | |
289 | fprintf (outf, " ="); | |
290 | break; | |
291 | case dir_positive_or_equal: | |
292 | fprintf (outf, " +="); | |
293 | break; | |
294 | case dir_positive_or_negative: | |
295 | fprintf (outf, " +-"); | |
296 | break; | |
297 | case dir_negative_or_equal: | |
298 | fprintf (outf, " -="); | |
299 | break; | |
300 | case dir_star: | |
301 | fprintf (outf, " *"); | |
302 | break; | |
303 | default: | |
304 | fprintf (outf, "indep"); | |
305 | break; | |
306 | } | |
307 | } | |
308 | fprintf (outf, "\n"); | |
309 | } | |
310 | ||
ba42e045 SP |
311 | /* Print a vector of direction vectors. */ |
312 | ||
aeb83f09 | 313 | static void |
ba42e045 SP |
314 | print_dir_vectors (FILE *outf, VEC (lambda_vector, heap) *dir_vects, |
315 | int length) | |
316 | { | |
317 | unsigned j; | |
318 | lambda_vector v; | |
319 | ||
ac47786e | 320 | FOR_EACH_VEC_ELT (lambda_vector, dir_vects, j, v) |
ba42e045 SP |
321 | print_direction_vector (outf, v, length); |
322 | } | |
323 | ||
b305e3da SP |
324 | /* Print out a vector VEC of length N to OUTFILE. */ |
325 | ||
326 | static inline void | |
327 | print_lambda_vector (FILE * outfile, lambda_vector vector, int n) | |
328 | { | |
329 | int i; | |
330 | ||
331 | for (i = 0; i < n; i++) | |
332 | fprintf (outfile, "%3d ", vector[i]); | |
333 | fprintf (outfile, "\n"); | |
334 | } | |
335 | ||
ba42e045 SP |
336 | /* Print a vector of distance vectors. */ |
337 | ||
aeb83f09 RG |
338 | static void |
339 | print_dist_vectors (FILE *outf, VEC (lambda_vector, heap) *dist_vects, | |
340 | int length) | |
ba42e045 SP |
341 | { |
342 | unsigned j; | |
343 | lambda_vector v; | |
344 | ||
ac47786e | 345 | FOR_EACH_VEC_ELT (lambda_vector, dist_vects, j, v) |
ba42e045 SP |
346 | print_lambda_vector (outf, v, length); |
347 | } | |
348 | ||
56cf8686 SP |
349 | /* Dump function for a DATA_DEPENDENCE_RELATION structure. */ |
350 | ||
aeb83f09 | 351 | static void |
b8698a0f | 352 | dump_data_dependence_relation (FILE *outf, |
56cf8686 SP |
353 | struct data_dependence_relation *ddr) |
354 | { | |
56cf8686 | 355 | struct data_reference *dra, *drb; |
86df10e3 | 356 | |
86df10e3 | 357 | fprintf (outf, "(Data Dep: \n"); |
dea61d92 | 358 | |
ed2024ba MJ |
359 | if (!ddr || DDR_ARE_DEPENDENT (ddr) == chrec_dont_know) |
360 | { | |
b61b1f17 MM |
361 | if (ddr) |
362 | { | |
363 | dra = DDR_A (ddr); | |
364 | drb = DDR_B (ddr); | |
365 | if (dra) | |
366 | dump_data_reference (outf, dra); | |
367 | else | |
368 | fprintf (outf, " (nil)\n"); | |
369 | if (drb) | |
370 | dump_data_reference (outf, drb); | |
371 | else | |
372 | fprintf (outf, " (nil)\n"); | |
373 | } | |
ed2024ba MJ |
374 | fprintf (outf, " (don't know)\n)\n"); |
375 | return; | |
376 | } | |
377 | ||
378 | dra = DDR_A (ddr); | |
379 | drb = DDR_B (ddr); | |
dea61d92 SP |
380 | dump_data_reference (outf, dra); |
381 | dump_data_reference (outf, drb); | |
382 | ||
ed2024ba | 383 | if (DDR_ARE_DEPENDENT (ddr) == chrec_known) |
56cf8686 | 384 | fprintf (outf, " (no dependence)\n"); |
b8698a0f | 385 | |
86df10e3 | 386 | else if (DDR_ARE_DEPENDENT (ddr) == NULL_TREE) |
56cf8686 | 387 | { |
86df10e3 | 388 | unsigned int i; |
ba42e045 | 389 | struct loop *loopi; |
304afda6 | 390 | |
56cf8686 SP |
391 | for (i = 0; i < DDR_NUM_SUBSCRIPTS (ddr); i++) |
392 | { | |
56cf8686 SP |
393 | fprintf (outf, " access_fn_A: "); |
394 | print_generic_stmt (outf, DR_ACCESS_FN (dra, i), 0); | |
395 | fprintf (outf, " access_fn_B: "); | |
396 | print_generic_stmt (outf, DR_ACCESS_FN (drb, i), 0); | |
86df10e3 | 397 | dump_subscript (outf, DDR_SUBSCRIPT (ddr, i)); |
56cf8686 | 398 | } |
304afda6 | 399 | |
3d8864c0 | 400 | fprintf (outf, " inner loop index: %d\n", DDR_INNER_LOOP (ddr)); |
ba42e045 | 401 | fprintf (outf, " loop nest: ("); |
ac47786e | 402 | FOR_EACH_VEC_ELT (loop_p, DDR_LOOP_NEST (ddr), i, loopi) |
ba42e045 SP |
403 | fprintf (outf, "%d ", loopi->num); |
404 | fprintf (outf, ")\n"); | |
405 | ||
304afda6 | 406 | for (i = 0; i < DDR_NUM_DIST_VECTS (ddr); i++) |
56cf8686 | 407 | { |
304afda6 SP |
408 | fprintf (outf, " distance_vector: "); |
409 | print_lambda_vector (outf, DDR_DIST_VECT (ddr, i), | |
ba42e045 | 410 | DDR_NB_LOOPS (ddr)); |
86df10e3 | 411 | } |
304afda6 SP |
412 | |
413 | for (i = 0; i < DDR_NUM_DIR_VECTS (ddr); i++) | |
86df10e3 | 414 | { |
304afda6 | 415 | fprintf (outf, " direction_vector: "); |
0ff4040e | 416 | print_direction_vector (outf, DDR_DIR_VECT (ddr, i), |
ba42e045 | 417 | DDR_NB_LOOPS (ddr)); |
56cf8686 | 418 | } |
56cf8686 SP |
419 | } |
420 | ||
421 | fprintf (outf, ")\n"); | |
422 | } | |
423 | ||
aeb83f09 | 424 | /* Debug version. */ |
56cf8686 | 425 | |
aeb83f09 RG |
426 | DEBUG_FUNCTION void |
427 | debug_data_dependence_relation (struct data_dependence_relation *ddr) | |
56cf8686 | 428 | { |
aeb83f09 RG |
429 | dump_data_dependence_relation (stderr, ddr); |
430 | } | |
b8698a0f | 431 | |
aeb83f09 | 432 | /* Dump into FILE all the dependence relations from DDRS. */ |
b8698a0f | 433 | |
aeb83f09 RG |
434 | void |
435 | dump_data_dependence_relations (FILE *file, | |
436 | VEC (ddr_p, heap) *ddrs) | |
437 | { | |
438 | unsigned int i; | |
439 | struct data_dependence_relation *ddr; | |
b8698a0f | 440 | |
aeb83f09 RG |
441 | FOR_EACH_VEC_ELT (ddr_p, ddrs, i, ddr) |
442 | dump_data_dependence_relation (file, ddr); | |
443 | } | |
b8698a0f | 444 | |
aeb83f09 | 445 | /* Dump to STDERR all the dependence relations from DDRS. */ |
b8698a0f | 446 | |
aeb83f09 RG |
447 | DEBUG_FUNCTION void |
448 | debug_data_dependence_relations (VEC (ddr_p, heap) *ddrs) | |
449 | { | |
450 | dump_data_dependence_relations (stderr, ddrs); | |
56cf8686 SP |
451 | } |
452 | ||
86df10e3 SP |
453 | /* Dumps the distance and direction vectors in FILE. DDRS contains |
454 | the dependence relations, and VECT_SIZE is the size of the | |
455 | dependence vectors, or in other words the number of loops in the | |
456 | considered nest. */ | |
457 | ||
aeb83f09 | 458 | static void |
ebf78a47 | 459 | dump_dist_dir_vectors (FILE *file, VEC (ddr_p, heap) *ddrs) |
86df10e3 | 460 | { |
304afda6 | 461 | unsigned int i, j; |
ebf78a47 SP |
462 | struct data_dependence_relation *ddr; |
463 | lambda_vector v; | |
86df10e3 | 464 | |
ac47786e | 465 | FOR_EACH_VEC_ELT (ddr_p, ddrs, i, ddr) |
ebf78a47 SP |
466 | if (DDR_ARE_DEPENDENT (ddr) == NULL_TREE && DDR_AFFINE_P (ddr)) |
467 | { | |
ac47786e | 468 | FOR_EACH_VEC_ELT (lambda_vector, DDR_DIST_VECTS (ddr), j, v) |
ebf78a47 SP |
469 | { |
470 | fprintf (file, "DISTANCE_V ("); | |
471 | print_lambda_vector (file, v, DDR_NB_LOOPS (ddr)); | |
472 | fprintf (file, ")\n"); | |
473 | } | |
474 | ||
ac47786e | 475 | FOR_EACH_VEC_ELT (lambda_vector, DDR_DIR_VECTS (ddr), j, v) |
ebf78a47 SP |
476 | { |
477 | fprintf (file, "DIRECTION_V ("); | |
478 | print_direction_vector (file, v, DDR_NB_LOOPS (ddr)); | |
479 | fprintf (file, ")\n"); | |
480 | } | |
481 | } | |
304afda6 | 482 | |
86df10e3 SP |
483 | fprintf (file, "\n\n"); |
484 | } | |
485 | ||
486 | /* Dumps the data dependence relations DDRS in FILE. */ | |
487 | ||
aeb83f09 | 488 | static void |
ebf78a47 | 489 | dump_ddrs (FILE *file, VEC (ddr_p, heap) *ddrs) |
86df10e3 SP |
490 | { |
491 | unsigned int i; | |
ebf78a47 SP |
492 | struct data_dependence_relation *ddr; |
493 | ||
ac47786e | 494 | FOR_EACH_VEC_ELT (ddr_p, ddrs, i, ddr) |
ebf78a47 | 495 | dump_data_dependence_relation (file, ddr); |
86df10e3 | 496 | |
86df10e3 SP |
497 | fprintf (file, "\n\n"); |
498 | } | |
499 | ||
aeb83f09 RG |
500 | DEBUG_FUNCTION void |
501 | debug_ddrs (VEC (ddr_p, heap) *ddrs) | |
502 | { | |
503 | dump_ddrs (stderr, ddrs); | |
504 | } | |
505 | ||
726a989a RB |
506 | /* Helper function for split_constant_offset. Expresses OP0 CODE OP1 |
507 | (the type of the result is TYPE) as VAR + OFF, where OFF is a nonzero | |
508 | constant of type ssizetype, and returns true. If we cannot do this | |
509 | with OFF nonzero, OFF and VAR are set to NULL_TREE instead and false | |
510 | is returned. */ | |
86a07404 | 511 | |
726a989a RB |
512 | static bool |
513 | split_constant_offset_1 (tree type, tree op0, enum tree_code code, tree op1, | |
514 | tree *var, tree *off) | |
86a07404 | 515 | { |
3cb960c7 ZD |
516 | tree var0, var1; |
517 | tree off0, off1; | |
726a989a | 518 | enum tree_code ocode = code; |
86a07404 | 519 | |
726a989a RB |
520 | *var = NULL_TREE; |
521 | *off = NULL_TREE; | |
86a07404 | 522 | |
5be014d5 | 523 | switch (code) |
86a07404 | 524 | { |
3cb960c7 ZD |
525 | case INTEGER_CST: |
526 | *var = build_int_cst (type, 0); | |
726a989a RB |
527 | *off = fold_convert (ssizetype, op0); |
528 | return true; | |
86a07404 | 529 | |
5be014d5 | 530 | case POINTER_PLUS_EXPR: |
726a989a | 531 | ocode = PLUS_EXPR; |
5be014d5 | 532 | /* FALLTHROUGH */ |
3cb960c7 ZD |
533 | case PLUS_EXPR: |
534 | case MINUS_EXPR: | |
726a989a RB |
535 | split_constant_offset (op0, &var0, &off0); |
536 | split_constant_offset (op1, &var1, &off1); | |
537 | *var = fold_build2 (code, type, var0, var1); | |
538 | *off = size_binop (ocode, off0, off1); | |
539 | return true; | |
86a07404 | 540 | |
86a07404 | 541 | case MULT_EXPR: |
726a989a RB |
542 | if (TREE_CODE (op1) != INTEGER_CST) |
543 | return false; | |
3cb960c7 | 544 | |
726a989a RB |
545 | split_constant_offset (op0, &var0, &off0); |
546 | *var = fold_build2 (MULT_EXPR, type, var0, op1); | |
547 | *off = size_binop (MULT_EXPR, off0, fold_convert (ssizetype, op1)); | |
548 | return true; | |
86a07404 | 549 | |
3cb960c7 ZD |
550 | case ADDR_EXPR: |
551 | { | |
726a989a | 552 | tree base, poffset; |
3cb960c7 ZD |
553 | HOST_WIDE_INT pbitsize, pbitpos; |
554 | enum machine_mode pmode; | |
555 | int punsignedp, pvolatilep; | |
86a07404 | 556 | |
da4b6efc | 557 | op0 = TREE_OPERAND (op0, 0); |
726a989a | 558 | base = get_inner_reference (op0, &pbitsize, &pbitpos, &poffset, |
3cb960c7 | 559 | &pmode, &punsignedp, &pvolatilep, false); |
86a07404 | 560 | |
3cb960c7 | 561 | if (pbitpos % BITS_PER_UNIT != 0) |
726a989a | 562 | return false; |
3cb960c7 ZD |
563 | base = build_fold_addr_expr (base); |
564 | off0 = ssize_int (pbitpos / BITS_PER_UNIT); | |
86a07404 | 565 | |
3cb960c7 ZD |
566 | if (poffset) |
567 | { | |
568 | split_constant_offset (poffset, &poffset, &off1); | |
569 | off0 = size_binop (PLUS_EXPR, off0, off1); | |
36ad7922 | 570 | if (POINTER_TYPE_P (TREE_TYPE (base))) |
5d49b6a7 | 571 | base = fold_build_pointer_plus (base, poffset); |
36ad7922 JJ |
572 | else |
573 | base = fold_build2 (PLUS_EXPR, TREE_TYPE (base), base, | |
574 | fold_convert (TREE_TYPE (base), poffset)); | |
3cb960c7 ZD |
575 | } |
576 | ||
6481b879 JJ |
577 | var0 = fold_convert (type, base); |
578 | ||
579 | /* If variable length types are involved, punt, otherwise casts | |
580 | might be converted into ARRAY_REFs in gimplify_conversion. | |
581 | To compute that ARRAY_REF's element size TYPE_SIZE_UNIT, which | |
582 | possibly no longer appears in current GIMPLE, might resurface. | |
583 | This perhaps could run | |
1a87cf0c | 584 | if (CONVERT_EXPR_P (var0)) |
6481b879 JJ |
585 | { |
586 | gimplify_conversion (&var0); | |
587 | // Attempt to fill in any within var0 found ARRAY_REF's | |
588 | // element size from corresponding op embedded ARRAY_REF, | |
589 | // if unsuccessful, just punt. | |
590 | } */ | |
591 | while (POINTER_TYPE_P (type)) | |
592 | type = TREE_TYPE (type); | |
593 | if (int_size_in_bytes (type) < 0) | |
726a989a | 594 | return false; |
6481b879 JJ |
595 | |
596 | *var = var0; | |
3cb960c7 | 597 | *off = off0; |
726a989a | 598 | return true; |
3cb960c7 | 599 | } |
86a07404 | 600 | |
06cb4f79 JS |
601 | case SSA_NAME: |
602 | { | |
726a989a RB |
603 | gimple def_stmt = SSA_NAME_DEF_STMT (op0); |
604 | enum tree_code subcode; | |
06cb4f79 | 605 | |
726a989a RB |
606 | if (gimple_code (def_stmt) != GIMPLE_ASSIGN) |
607 | return false; | |
608 | ||
609 | var0 = gimple_assign_rhs1 (def_stmt); | |
610 | subcode = gimple_assign_rhs_code (def_stmt); | |
611 | var1 = gimple_assign_rhs2 (def_stmt); | |
612 | ||
613 | return split_constant_offset_1 (type, var0, subcode, var1, var, off); | |
06cb4f79 | 614 | } |
b61b1f17 MM |
615 | CASE_CONVERT: |
616 | { | |
617 | /* We must not introduce undefined overflow, and we must not change the value. | |
618 | Hence we're okay if the inner type doesn't overflow to start with | |
619 | (pointer or signed), the outer type also is an integer or pointer | |
620 | and the outer precision is at least as large as the inner. */ | |
621 | tree itype = TREE_TYPE (op0); | |
622 | if ((POINTER_TYPE_P (itype) | |
623 | || (INTEGRAL_TYPE_P (itype) && TYPE_OVERFLOW_UNDEFINED (itype))) | |
624 | && TYPE_PRECISION (type) >= TYPE_PRECISION (itype) | |
625 | && (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))) | |
626 | { | |
627 | split_constant_offset (op0, &var0, off); | |
628 | *var = fold_convert (type, var0); | |
629 | return true; | |
630 | } | |
631 | return false; | |
632 | } | |
06cb4f79 | 633 | |
86a07404 | 634 | default: |
726a989a | 635 | return false; |
86a07404 | 636 | } |
726a989a RB |
637 | } |
638 | ||
639 | /* Expresses EXP as VAR + OFF, where off is a constant. The type of OFF | |
640 | will be ssizetype. */ | |
641 | ||
642 | void | |
643 | split_constant_offset (tree exp, tree *var, tree *off) | |
644 | { | |
645 | tree type = TREE_TYPE (exp), otype, op0, op1, e, o; | |
646 | enum tree_code code; | |
86a07404 | 647 | |
726a989a | 648 | *var = exp; |
3cb960c7 | 649 | *off = ssize_int (0); |
726a989a RB |
650 | STRIP_NOPS (exp); |
651 | ||
ffd78b30 RG |
652 | if (tree_is_chrec (exp) |
653 | || get_gimple_rhs_class (TREE_CODE (exp)) == GIMPLE_TERNARY_RHS) | |
726a989a RB |
654 | return; |
655 | ||
656 | otype = TREE_TYPE (exp); | |
657 | code = TREE_CODE (exp); | |
658 | extract_ops_from_tree (exp, &code, &op0, &op1); | |
659 | if (split_constant_offset_1 (otype, op0, code, op1, &e, &o)) | |
660 | { | |
661 | *var = fold_convert (type, e); | |
662 | *off = o; | |
663 | } | |
86a07404 IR |
664 | } |
665 | ||
3cb960c7 ZD |
666 | /* Returns the address ADDR of an object in a canonical shape (without nop |
667 | casts, and with type of pointer to the object). */ | |
86a07404 IR |
668 | |
669 | static tree | |
3cb960c7 | 670 | canonicalize_base_object_address (tree addr) |
86a07404 | 671 | { |
bbc8a8dc ZD |
672 | tree orig = addr; |
673 | ||
3cb960c7 | 674 | STRIP_NOPS (addr); |
86a07404 | 675 | |
bbc8a8dc ZD |
676 | /* The base address may be obtained by casting from integer, in that case |
677 | keep the cast. */ | |
678 | if (!POINTER_TYPE_P (TREE_TYPE (addr))) | |
679 | return orig; | |
680 | ||
3cb960c7 ZD |
681 | if (TREE_CODE (addr) != ADDR_EXPR) |
682 | return addr; | |
86a07404 | 683 | |
3cb960c7 | 684 | return build_fold_addr_expr (TREE_OPERAND (addr, 0)); |
86a07404 IR |
685 | } |
686 | ||
b8698a0f | 687 | /* Analyzes the behavior of the memory reference DR in the innermost loop or |
4e4452b6 | 688 | basic block that contains it. Returns true if analysis succeed or false |
a70d6342 | 689 | otherwise. */ |
86a07404 | 690 | |
3661e899 | 691 | bool |
4e4452b6 | 692 | dr_analyze_innermost (struct data_reference *dr, struct loop *nest) |
86a07404 | 693 | { |
726a989a | 694 | gimple stmt = DR_STMT (dr); |
3cb960c7 ZD |
695 | struct loop *loop = loop_containing_stmt (stmt); |
696 | tree ref = DR_REF (dr); | |
86a07404 | 697 | HOST_WIDE_INT pbitsize, pbitpos; |
3cb960c7 | 698 | tree base, poffset; |
86a07404 IR |
699 | enum machine_mode pmode; |
700 | int punsignedp, pvolatilep; | |
3cb960c7 ZD |
701 | affine_iv base_iv, offset_iv; |
702 | tree init, dinit, step; | |
a70d6342 | 703 | bool in_loop = (loop && loop->num); |
3cb960c7 ZD |
704 | |
705 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
706 | fprintf (dump_file, "analyze_innermost: "); | |
86a07404 | 707 | |
3cb960c7 ZD |
708 | base = get_inner_reference (ref, &pbitsize, &pbitpos, &poffset, |
709 | &pmode, &punsignedp, &pvolatilep, false); | |
710 | gcc_assert (base != NULL_TREE); | |
86a07404 | 711 | |
3cb960c7 | 712 | if (pbitpos % BITS_PER_UNIT != 0) |
86a07404 | 713 | { |
3cb960c7 ZD |
714 | if (dump_file && (dump_flags & TDF_DETAILS)) |
715 | fprintf (dump_file, "failed: bit offset alignment.\n"); | |
3661e899 | 716 | return false; |
3cb960c7 | 717 | } |
86a07404 | 718 | |
70f34814 RG |
719 | if (TREE_CODE (base) == MEM_REF) |
720 | { | |
721 | if (!integer_zerop (TREE_OPERAND (base, 1))) | |
722 | { | |
723 | if (!poffset) | |
724 | { | |
725 | double_int moff = mem_ref_offset (base); | |
726 | poffset = double_int_to_tree (sizetype, moff); | |
727 | } | |
728 | else | |
729 | poffset = size_binop (PLUS_EXPR, poffset, TREE_OPERAND (base, 1)); | |
730 | } | |
731 | base = TREE_OPERAND (base, 0); | |
732 | } | |
733 | else | |
734 | base = build_fold_addr_expr (base); | |
4e4452b6 | 735 | |
a70d6342 | 736 | if (in_loop) |
3cb960c7 | 737 | { |
b8698a0f | 738 | if (!simple_iv (loop, loop_containing_stmt (stmt), base, &base_iv, |
a70d6342 IR |
739 | false)) |
740 | { | |
4e4452b6 IR |
741 | if (nest) |
742 | { | |
743 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
744 | fprintf (dump_file, "failed: evolution of base is not" | |
745 | " affine.\n"); | |
746 | return false; | |
747 | } | |
748 | else | |
749 | { | |
750 | base_iv.base = base; | |
751 | base_iv.step = ssize_int (0); | |
752 | base_iv.no_overflow = true; | |
753 | } | |
a70d6342 IR |
754 | } |
755 | } | |
756 | else | |
757 | { | |
758 | base_iv.base = base; | |
759 | base_iv.step = ssize_int (0); | |
760 | base_iv.no_overflow = true; | |
3cb960c7 | 761 | } |
a70d6342 | 762 | |
24adb18f | 763 | if (!poffset) |
3cb960c7 ZD |
764 | { |
765 | offset_iv.base = ssize_int (0); | |
766 | offset_iv.step = ssize_int (0); | |
767 | } | |
24adb18f | 768 | else |
3cb960c7 | 769 | { |
24adb18f IR |
770 | if (!in_loop) |
771 | { | |
772 | offset_iv.base = poffset; | |
773 | offset_iv.step = ssize_int (0); | |
774 | } | |
775 | else if (!simple_iv (loop, loop_containing_stmt (stmt), | |
776 | poffset, &offset_iv, false)) | |
777 | { | |
4e4452b6 IR |
778 | if (nest) |
779 | { | |
780 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
781 | fprintf (dump_file, "failed: evolution of offset is not" | |
782 | " affine.\n"); | |
783 | return false; | |
784 | } | |
785 | else | |
786 | { | |
787 | offset_iv.base = poffset; | |
788 | offset_iv.step = ssize_int (0); | |
789 | } | |
24adb18f | 790 | } |
3cb960c7 | 791 | } |
86a07404 | 792 | |
3cb960c7 ZD |
793 | init = ssize_int (pbitpos / BITS_PER_UNIT); |
794 | split_constant_offset (base_iv.base, &base_iv.base, &dinit); | |
795 | init = size_binop (PLUS_EXPR, init, dinit); | |
796 | split_constant_offset (offset_iv.base, &offset_iv.base, &dinit); | |
797 | init = size_binop (PLUS_EXPR, init, dinit); | |
86a07404 | 798 | |
3cb960c7 ZD |
799 | step = size_binop (PLUS_EXPR, |
800 | fold_convert (ssizetype, base_iv.step), | |
801 | fold_convert (ssizetype, offset_iv.step)); | |
86a07404 | 802 | |
3cb960c7 | 803 | DR_BASE_ADDRESS (dr) = canonicalize_base_object_address (base_iv.base); |
86a07404 | 804 | |
3cb960c7 ZD |
805 | DR_OFFSET (dr) = fold_convert (ssizetype, offset_iv.base); |
806 | DR_INIT (dr) = init; | |
807 | DR_STEP (dr) = step; | |
86a07404 | 808 | |
3cb960c7 | 809 | DR_ALIGNED_TO (dr) = size_int (highest_pow2_factor (offset_iv.base)); |
86a07404 | 810 | |
3cb960c7 ZD |
811 | if (dump_file && (dump_flags & TDF_DETAILS)) |
812 | fprintf (dump_file, "success.\n"); | |
3661e899 TB |
813 | |
814 | return true; | |
3cb960c7 | 815 | } |
86a07404 | 816 | |
3cb960c7 | 817 | /* Determines the base object and the list of indices of memory reference |
5c640e29 | 818 | DR, analyzed in LOOP and instantiated in loop nest NEST. */ |
86a07404 | 819 | |
3cb960c7 | 820 | static void |
5c640e29 | 821 | dr_analyze_indices (struct data_reference *dr, loop_p nest, loop_p loop) |
3cb960c7 | 822 | { |
3cb960c7 | 823 | VEC (tree, heap) *access_fns = NULL; |
c4ddde1b | 824 | tree ref, op; |
9fcb758b RG |
825 | tree base, off, access_fn; |
826 | basic_block before_loop; | |
b8698a0f | 827 | |
9fcb758b RG |
828 | /* If analyzing a basic-block there are no indices to analyze |
829 | and thus no access functions. */ | |
02f5d6c5 RG |
830 | if (!nest) |
831 | { | |
9fcb758b | 832 | DR_BASE_OBJECT (dr) = DR_REF (dr); |
02f5d6c5 RG |
833 | DR_ACCESS_FNS (dr) = NULL; |
834 | return; | |
835 | } | |
836 | ||
c4ddde1b | 837 | ref = DR_REF (dr); |
02f5d6c5 | 838 | before_loop = block_before_loop (nest); |
b8698a0f | 839 | |
9fcb758b RG |
840 | /* REALPART_EXPR and IMAGPART_EXPR can be handled like accesses |
841 | into a two element array with a constant index. The base is | |
842 | then just the immediate underlying object. */ | |
843 | if (TREE_CODE (ref) == REALPART_EXPR) | |
844 | { | |
845 | ref = TREE_OPERAND (ref, 0); | |
846 | VEC_safe_push (tree, heap, access_fns, integer_zero_node); | |
847 | } | |
848 | else if (TREE_CODE (ref) == IMAGPART_EXPR) | |
849 | { | |
850 | ref = TREE_OPERAND (ref, 0); | |
851 | VEC_safe_push (tree, heap, access_fns, integer_one_node); | |
852 | } | |
853 | ||
b8324815 | 854 | /* Analyze access functions of dimensions we know to be independent. */ |
c4ddde1b | 855 | while (handled_component_p (ref)) |
86a07404 | 856 | { |
c4ddde1b | 857 | if (TREE_CODE (ref) == ARRAY_REF) |
86a07404 | 858 | { |
c4ddde1b | 859 | op = TREE_OPERAND (ref, 1); |
02f5d6c5 RG |
860 | access_fn = analyze_scalar_evolution (loop, op); |
861 | access_fn = instantiate_scev (before_loop, loop, access_fn); | |
862 | VEC_safe_push (tree, heap, access_fns, access_fn); | |
b8324815 | 863 | } |
c4ddde1b RG |
864 | else if (TREE_CODE (ref) == COMPONENT_REF |
865 | && TREE_CODE (TREE_TYPE (TREE_OPERAND (ref, 0))) == RECORD_TYPE) | |
866 | { | |
867 | /* For COMPONENT_REFs of records (but not unions!) use the | |
868 | FIELD_DECL offset as constant access function so we can | |
869 | disambiguate a[i].f1 and a[i].f2. */ | |
870 | tree off = component_ref_field_offset (ref); | |
871 | off = size_binop (PLUS_EXPR, | |
872 | size_binop (MULT_EXPR, | |
873 | fold_convert (bitsizetype, off), | |
874 | bitsize_int (BITS_PER_UNIT)), | |
875 | DECL_FIELD_BIT_OFFSET (TREE_OPERAND (ref, 1))); | |
876 | VEC_safe_push (tree, heap, access_fns, off); | |
877 | } | |
878 | else | |
879 | /* If we have an unhandled component we could not translate | |
880 | to an access function stop analyzing. We have determined | |
881 | our base object in this case. */ | |
882 | break; | |
b8698a0f | 883 | |
c4ddde1b | 884 | ref = TREE_OPERAND (ref, 0); |
86a07404 IR |
885 | } |
886 | ||
8c330caa RG |
887 | /* If the address operand of a MEM_REF base has an evolution in the |
888 | analyzed nest, add it as an additional independent access-function. */ | |
c4ddde1b | 889 | if (TREE_CODE (ref) == MEM_REF) |
86a07404 | 890 | { |
c4ddde1b | 891 | op = TREE_OPERAND (ref, 0); |
3cb960c7 | 892 | access_fn = analyze_scalar_evolution (loop, op); |
a213b219 | 893 | access_fn = instantiate_scev (before_loop, loop, access_fn); |
8c330caa | 894 | if (TREE_CODE (access_fn) == POLYNOMIAL_CHREC) |
2946bd34 | 895 | { |
0a500dd3 | 896 | tree orig_type; |
c4ddde1b | 897 | tree memoff = TREE_OPERAND (ref, 1); |
8c330caa | 898 | base = initial_condition (access_fn); |
0a500dd3 RG |
899 | orig_type = TREE_TYPE (base); |
900 | STRIP_USELESS_TYPE_CONVERSION (base); | |
8c330caa RG |
901 | split_constant_offset (base, &base, &off); |
902 | /* Fold the MEM_REF offset into the evolutions initial | |
903 | value to make more bases comparable. */ | |
c4ddde1b | 904 | if (!integer_zerop (memoff)) |
8c330caa RG |
905 | { |
906 | off = size_binop (PLUS_EXPR, off, | |
c4ddde1b RG |
907 | fold_convert (ssizetype, memoff)); |
908 | memoff = build_int_cst (TREE_TYPE (memoff), 0); | |
8c330caa RG |
909 | } |
910 | access_fn = chrec_replace_initial_condition | |
0a500dd3 | 911 | (access_fn, fold_convert (orig_type, off)); |
c4ddde1b RG |
912 | /* ??? This is still not a suitable base object for |
913 | dr_may_alias_p - the base object needs to be an | |
914 | access that covers the object as whole. With | |
915 | an evolution in the pointer this cannot be | |
916 | guaranteed. | |
917 | As a band-aid, mark the access so we can special-case | |
918 | it in dr_may_alias_p. */ | |
919 | ref = fold_build2_loc (EXPR_LOCATION (ref), | |
920 | MEM_REF, TREE_TYPE (ref), | |
921 | base, memoff); | |
922 | DR_UNCONSTRAINED_BASE (dr) = true; | |
8c330caa | 923 | VEC_safe_push (tree, heap, access_fns, access_fn); |
2946bd34 | 924 | } |
86a07404 | 925 | } |
c4ddde1b RG |
926 | else if (DECL_P (ref)) |
927 | { | |
928 | /* Canonicalize DR_BASE_OBJECT to MEM_REF form. */ | |
929 | ref = build2 (MEM_REF, TREE_TYPE (ref), | |
930 | build_fold_addr_expr (ref), | |
931 | build_int_cst (reference_alias_ptr_type (ref), 0)); | |
932 | } | |
86a07404 | 933 | |
3cb960c7 ZD |
934 | DR_BASE_OBJECT (dr) = ref; |
935 | DR_ACCESS_FNS (dr) = access_fns; | |
86a07404 IR |
936 | } |
937 | ||
3cb960c7 | 938 | /* Extracts the alias analysis information from the memory reference DR. */ |
86a07404 | 939 | |
3cb960c7 ZD |
940 | static void |
941 | dr_analyze_alias (struct data_reference *dr) | |
86a07404 | 942 | { |
3cb960c7 | 943 | tree ref = DR_REF (dr); |
5006671f RG |
944 | tree base = get_base_address (ref), addr; |
945 | ||
70f34814 RG |
946 | if (INDIRECT_REF_P (base) |
947 | || TREE_CODE (base) == MEM_REF) | |
3cb960c7 ZD |
948 | { |
949 | addr = TREE_OPERAND (base, 0); | |
950 | if (TREE_CODE (addr) == SSA_NAME) | |
5006671f | 951 | DR_PTR_INFO (dr) = SSA_NAME_PTR_INFO (addr); |
3cb960c7 | 952 | } |
3cb960c7 | 953 | } |
86a07404 | 954 | |
3cb960c7 | 955 | /* Frees data reference DR. */ |
8fdbc9c6 | 956 | |
dea61d92 | 957 | void |
8fdbc9c6 ZD |
958 | free_data_ref (data_reference_p dr) |
959 | { | |
3cb960c7 | 960 | VEC_free (tree, heap, DR_ACCESS_FNS (dr)); |
8fdbc9c6 ZD |
961 | free (dr); |
962 | } | |
86a07404 | 963 | |
3cb960c7 ZD |
964 | /* Analyzes memory reference MEMREF accessed in STMT. The reference |
965 | is read if IS_READ is true, write otherwise. Returns the | |
5c640e29 SP |
966 | data_reference description of MEMREF. NEST is the outermost loop |
967 | in which the reference should be instantiated, LOOP is the loop in | |
968 | which the data reference should be analyzed. */ | |
86a07404 | 969 | |
5417e022 | 970 | struct data_reference * |
5c640e29 SP |
971 | create_data_ref (loop_p nest, loop_p loop, tree memref, gimple stmt, |
972 | bool is_read) | |
86a07404 | 973 | { |
3cb960c7 | 974 | struct data_reference *dr; |
0ff4040e | 975 | |
3cb960c7 | 976 | if (dump_file && (dump_flags & TDF_DETAILS)) |
0ff4040e | 977 | { |
3cb960c7 ZD |
978 | fprintf (dump_file, "Creating dr for "); |
979 | print_generic_expr (dump_file, memref, TDF_SLIM); | |
980 | fprintf (dump_file, "\n"); | |
0ff4040e | 981 | } |
e2157b49 | 982 | |
3cb960c7 ZD |
983 | dr = XCNEW (struct data_reference); |
984 | DR_STMT (dr) = stmt; | |
985 | DR_REF (dr) = memref; | |
986 | DR_IS_READ (dr) = is_read; | |
86a07404 | 987 | |
4e4452b6 | 988 | dr_analyze_innermost (dr, nest); |
5c640e29 | 989 | dr_analyze_indices (dr, nest, loop); |
3cb960c7 | 990 | dr_analyze_alias (dr); |
86a07404 IR |
991 | |
992 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
993 | { | |
b8324815 | 994 | unsigned i; |
3cb960c7 | 995 | fprintf (dump_file, "\tbase_address: "); |
86a07404 IR |
996 | print_generic_expr (dump_file, DR_BASE_ADDRESS (dr), TDF_SLIM); |
997 | fprintf (dump_file, "\n\toffset from base address: "); | |
998 | print_generic_expr (dump_file, DR_OFFSET (dr), TDF_SLIM); | |
999 | fprintf (dump_file, "\n\tconstant offset from base address: "); | |
1000 | print_generic_expr (dump_file, DR_INIT (dr), TDF_SLIM); | |
86a07404 IR |
1001 | fprintf (dump_file, "\n\tstep: "); |
1002 | print_generic_expr (dump_file, DR_STEP (dr), TDF_SLIM); | |
3cb960c7 ZD |
1003 | fprintf (dump_file, "\n\taligned to: "); |
1004 | print_generic_expr (dump_file, DR_ALIGNED_TO (dr), TDF_SLIM); | |
1005 | fprintf (dump_file, "\n\tbase_object: "); | |
1006 | print_generic_expr (dump_file, DR_BASE_OBJECT (dr), TDF_SLIM); | |
86a07404 | 1007 | fprintf (dump_file, "\n"); |
b8324815 RG |
1008 | for (i = 0; i < DR_NUM_DIMENSIONS (dr); i++) |
1009 | { | |
1010 | fprintf (dump_file, "\tAccess function %d: ", i); | |
1011 | print_generic_stmt (dump_file, DR_ACCESS_FN (dr, i), TDF_SLIM); | |
1012 | } | |
3cb960c7 ZD |
1013 | } |
1014 | ||
b8698a0f | 1015 | return dr; |
86a07404 IR |
1016 | } |
1017 | ||
bfe068c3 IR |
1018 | /* Check if OFFSET1 and OFFSET2 (DR_OFFSETs of some data-refs) are identical |
1019 | expressions. */ | |
1020 | static bool | |
1021 | dr_equal_offsets_p1 (tree offset1, tree offset2) | |
1022 | { | |
1023 | bool res; | |
1024 | ||
1025 | STRIP_NOPS (offset1); | |
1026 | STRIP_NOPS (offset2); | |
1027 | ||
1028 | if (offset1 == offset2) | |
1029 | return true; | |
1030 | ||
1031 | if (TREE_CODE (offset1) != TREE_CODE (offset2) | |
1032 | || (!BINARY_CLASS_P (offset1) && !UNARY_CLASS_P (offset1))) | |
1033 | return false; | |
1034 | ||
1035 | res = dr_equal_offsets_p1 (TREE_OPERAND (offset1, 0), | |
1036 | TREE_OPERAND (offset2, 0)); | |
1037 | ||
1038 | if (!res || !BINARY_CLASS_P (offset1)) | |
1039 | return res; | |
1040 | ||
1041 | res = dr_equal_offsets_p1 (TREE_OPERAND (offset1, 1), | |
1042 | TREE_OPERAND (offset2, 1)); | |
1043 | ||
1044 | return res; | |
1045 | } | |
1046 | ||
1047 | /* Check if DRA and DRB have equal offsets. */ | |
1048 | bool | |
1049 | dr_equal_offsets_p (struct data_reference *dra, | |
1050 | struct data_reference *drb) | |
1051 | { | |
1052 | tree offset1, offset2; | |
1053 | ||
1054 | offset1 = DR_OFFSET (dra); | |
1055 | offset2 = DR_OFFSET (drb); | |
1056 | ||
1057 | return dr_equal_offsets_p1 (offset1, offset2); | |
1058 | } | |
1059 | ||
d93817c4 ZD |
1060 | /* Returns true if FNA == FNB. */ |
1061 | ||
1062 | static bool | |
1063 | affine_function_equal_p (affine_fn fna, affine_fn fnb) | |
1064 | { | |
1065 | unsigned i, n = VEC_length (tree, fna); | |
86a07404 | 1066 | |
f86289d5 ZD |
1067 | if (n != VEC_length (tree, fnb)) |
1068 | return false; | |
86df10e3 | 1069 | |
d93817c4 ZD |
1070 | for (i = 0; i < n; i++) |
1071 | if (!operand_equal_p (VEC_index (tree, fna, i), | |
1072 | VEC_index (tree, fnb, i), 0)) | |
1073 | return false; | |
1074 | ||
1075 | return true; | |
1076 | } | |
1077 | ||
1078 | /* If all the functions in CF are the same, returns one of them, | |
1079 | otherwise returns NULL. */ | |
1080 | ||
1081 | static affine_fn | |
1082 | common_affine_function (conflict_function *cf) | |
86df10e3 | 1083 | { |
d93817c4 ZD |
1084 | unsigned i; |
1085 | affine_fn comm; | |
1086 | ||
1087 | if (!CF_NONTRIVIAL_P (cf)) | |
1088 | return NULL; | |
1089 | ||
1090 | comm = cf->fns[0]; | |
1091 | ||
1092 | for (i = 1; i < cf->n; i++) | |
1093 | if (!affine_function_equal_p (comm, cf->fns[i])) | |
1094 | return NULL; | |
1095 | ||
1096 | return comm; | |
1097 | } | |
86df10e3 | 1098 | |
d93817c4 ZD |
1099 | /* Returns the base of the affine function FN. */ |
1100 | ||
1101 | static tree | |
1102 | affine_function_base (affine_fn fn) | |
1103 | { | |
1104 | return VEC_index (tree, fn, 0); | |
1105 | } | |
1106 | ||
1107 | /* Returns true if FN is a constant. */ | |
1108 | ||
1109 | static bool | |
1110 | affine_function_constant_p (affine_fn fn) | |
1111 | { | |
1112 | unsigned i; | |
1113 | tree coef; | |
1114 | ||
1115 | for (i = 1; VEC_iterate (tree, fn, i, coef); i++) | |
1116 | if (!integer_zerop (coef)) | |
e2157b49 SP |
1117 | return false; |
1118 | ||
86df10e3 SP |
1119 | return true; |
1120 | } | |
1121 | ||
1baf2906 SP |
1122 | /* Returns true if FN is the zero constant function. */ |
1123 | ||
1124 | static bool | |
1125 | affine_function_zero_p (affine_fn fn) | |
1126 | { | |
1127 | return (integer_zerop (affine_function_base (fn)) | |
1128 | && affine_function_constant_p (fn)); | |
1129 | } | |
1130 | ||
33b30201 SP |
1131 | /* Returns a signed integer type with the largest precision from TA |
1132 | and TB. */ | |
1133 | ||
1134 | static tree | |
1135 | signed_type_for_types (tree ta, tree tb) | |
1136 | { | |
1137 | if (TYPE_PRECISION (ta) > TYPE_PRECISION (tb)) | |
1138 | return signed_type_for (ta); | |
1139 | else | |
1140 | return signed_type_for (tb); | |
1141 | } | |
1142 | ||
d93817c4 ZD |
1143 | /* Applies operation OP on affine functions FNA and FNB, and returns the |
1144 | result. */ | |
1145 | ||
1146 | static affine_fn | |
1147 | affine_fn_op (enum tree_code op, affine_fn fna, affine_fn fnb) | |
1148 | { | |
1149 | unsigned i, n, m; | |
1150 | affine_fn ret; | |
1151 | tree coef; | |
1152 | ||
1153 | if (VEC_length (tree, fnb) > VEC_length (tree, fna)) | |
1154 | { | |
1155 | n = VEC_length (tree, fna); | |
1156 | m = VEC_length (tree, fnb); | |
1157 | } | |
1158 | else | |
1159 | { | |
1160 | n = VEC_length (tree, fnb); | |
1161 | m = VEC_length (tree, fna); | |
1162 | } | |
1163 | ||
1164 | ret = VEC_alloc (tree, heap, m); | |
1165 | for (i = 0; i < n; i++) | |
33b30201 SP |
1166 | { |
1167 | tree type = signed_type_for_types (TREE_TYPE (VEC_index (tree, fna, i)), | |
1168 | TREE_TYPE (VEC_index (tree, fnb, i))); | |
1169 | ||
1170 | VEC_quick_push (tree, ret, | |
1171 | fold_build2 (op, type, | |
b8698a0f | 1172 | VEC_index (tree, fna, i), |
33b30201 SP |
1173 | VEC_index (tree, fnb, i))); |
1174 | } | |
d93817c4 ZD |
1175 | |
1176 | for (; VEC_iterate (tree, fna, i, coef); i++) | |
1177 | VEC_quick_push (tree, ret, | |
33b30201 | 1178 | fold_build2 (op, signed_type_for (TREE_TYPE (coef)), |
d93817c4 ZD |
1179 | coef, integer_zero_node)); |
1180 | for (; VEC_iterate (tree, fnb, i, coef); i++) | |
1181 | VEC_quick_push (tree, ret, | |
33b30201 | 1182 | fold_build2 (op, signed_type_for (TREE_TYPE (coef)), |
d93817c4 ZD |
1183 | integer_zero_node, coef)); |
1184 | ||
1185 | return ret; | |
1186 | } | |
1187 | ||
1188 | /* Returns the sum of affine functions FNA and FNB. */ | |
1189 | ||
1190 | static affine_fn | |
1191 | affine_fn_plus (affine_fn fna, affine_fn fnb) | |
1192 | { | |
1193 | return affine_fn_op (PLUS_EXPR, fna, fnb); | |
1194 | } | |
1195 | ||
1196 | /* Returns the difference of affine functions FNA and FNB. */ | |
1197 | ||
1198 | static affine_fn | |
1199 | affine_fn_minus (affine_fn fna, affine_fn fnb) | |
1200 | { | |
1201 | return affine_fn_op (MINUS_EXPR, fna, fnb); | |
1202 | } | |
1203 | ||
1204 | /* Frees affine function FN. */ | |
1205 | ||
1206 | static void | |
1207 | affine_fn_free (affine_fn fn) | |
1208 | { | |
1209 | VEC_free (tree, heap, fn); | |
1210 | } | |
1211 | ||
86df10e3 SP |
1212 | /* Determine for each subscript in the data dependence relation DDR |
1213 | the distance. */ | |
56cf8686 | 1214 | |
0ff4040e | 1215 | static void |
86df10e3 | 1216 | compute_subscript_distance (struct data_dependence_relation *ddr) |
56cf8686 | 1217 | { |
d93817c4 ZD |
1218 | conflict_function *cf_a, *cf_b; |
1219 | affine_fn fn_a, fn_b, diff; | |
1220 | ||
56cf8686 SP |
1221 | if (DDR_ARE_DEPENDENT (ddr) == NULL_TREE) |
1222 | { | |
1223 | unsigned int i; | |
b8698a0f | 1224 | |
56cf8686 SP |
1225 | for (i = 0; i < DDR_NUM_SUBSCRIPTS (ddr); i++) |
1226 | { | |
56cf8686 | 1227 | struct subscript *subscript; |
b8698a0f | 1228 | |
56cf8686 | 1229 | subscript = DDR_SUBSCRIPT (ddr, i); |
d93817c4 ZD |
1230 | cf_a = SUB_CONFLICTS_IN_A (subscript); |
1231 | cf_b = SUB_CONFLICTS_IN_B (subscript); | |
86df10e3 | 1232 | |
d93817c4 ZD |
1233 | fn_a = common_affine_function (cf_a); |
1234 | fn_b = common_affine_function (cf_b); | |
1235 | if (!fn_a || !fn_b) | |
86df10e3 | 1236 | { |
d93817c4 ZD |
1237 | SUB_DISTANCE (subscript) = chrec_dont_know; |
1238 | return; | |
86df10e3 | 1239 | } |
d93817c4 | 1240 | diff = affine_fn_minus (fn_a, fn_b); |
b8698a0f | 1241 | |
d93817c4 ZD |
1242 | if (affine_function_constant_p (diff)) |
1243 | SUB_DISTANCE (subscript) = affine_function_base (diff); | |
56cf8686 SP |
1244 | else |
1245 | SUB_DISTANCE (subscript) = chrec_dont_know; | |
d93817c4 ZD |
1246 | |
1247 | affine_fn_free (diff); | |
56cf8686 SP |
1248 | } |
1249 | } | |
1250 | } | |
1251 | ||
d93817c4 ZD |
1252 | /* Returns the conflict function for "unknown". */ |
1253 | ||
1254 | static conflict_function * | |
1255 | conflict_fn_not_known (void) | |
1256 | { | |
1257 | conflict_function *fn = XCNEW (conflict_function); | |
1258 | fn->n = NOT_KNOWN; | |
1259 | ||
1260 | return fn; | |
1261 | } | |
1262 | ||
1263 | /* Returns the conflict function for "independent". */ | |
1264 | ||
1265 | static conflict_function * | |
1266 | conflict_fn_no_dependence (void) | |
1267 | { | |
1268 | conflict_function *fn = XCNEW (conflict_function); | |
1269 | fn->n = NO_DEPENDENCE; | |
1270 | ||
1271 | return fn; | |
1272 | } | |
1273 | ||
3cb960c7 ZD |
1274 | /* Returns true if the address of OBJ is invariant in LOOP. */ |
1275 | ||
1276 | static bool | |
ed7a4b4b | 1277 | object_address_invariant_in_loop_p (const struct loop *loop, const_tree obj) |
3cb960c7 ZD |
1278 | { |
1279 | while (handled_component_p (obj)) | |
1280 | { | |
1281 | if (TREE_CODE (obj) == ARRAY_REF) | |
1282 | { | |
1283 | /* Index of the ARRAY_REF was zeroed in analyze_indices, thus we only | |
1284 | need to check the stride and the lower bound of the reference. */ | |
1285 | if (chrec_contains_symbols_defined_in_loop (TREE_OPERAND (obj, 2), | |
1286 | loop->num) | |
1287 | || chrec_contains_symbols_defined_in_loop (TREE_OPERAND (obj, 3), | |
1288 | loop->num)) | |
1289 | return false; | |
1290 | } | |
1291 | else if (TREE_CODE (obj) == COMPONENT_REF) | |
1292 | { | |
1293 | if (chrec_contains_symbols_defined_in_loop (TREE_OPERAND (obj, 2), | |
1294 | loop->num)) | |
1295 | return false; | |
1296 | } | |
1297 | obj = TREE_OPERAND (obj, 0); | |
1298 | } | |
1299 | ||
70f34814 RG |
1300 | if (!INDIRECT_REF_P (obj) |
1301 | && TREE_CODE (obj) != MEM_REF) | |
3cb960c7 ZD |
1302 | return true; |
1303 | ||
1304 | return !chrec_contains_symbols_defined_in_loop (TREE_OPERAND (obj, 0), | |
1305 | loop->num); | |
1306 | } | |
1307 | ||
3cb960c7 | 1308 | /* Returns false if we can prove that data references A and B do not alias, |
02f5d6c5 RG |
1309 | true otherwise. If LOOP_NEST is false no cross-iteration aliases are |
1310 | considered. */ | |
3cb960c7 | 1311 | |
f8bf9252 | 1312 | bool |
02f5d6c5 RG |
1313 | dr_may_alias_p (const struct data_reference *a, const struct data_reference *b, |
1314 | bool loop_nest) | |
3cb960c7 | 1315 | { |
7d36e538 RG |
1316 | tree addr_a = DR_BASE_OBJECT (a); |
1317 | tree addr_b = DR_BASE_OBJECT (b); | |
3cb960c7 | 1318 | |
02f5d6c5 RG |
1319 | /* If we are not processing a loop nest but scalar code we |
1320 | do not need to care about possible cross-iteration dependences | |
1321 | and thus can process the full original reference. Do so, | |
1322 | similar to how loop invariant motion applies extra offset-based | |
1323 | disambiguation. */ | |
1324 | if (!loop_nest) | |
1325 | { | |
1326 | aff_tree off1, off2; | |
1327 | double_int size1, size2; | |
1328 | get_inner_reference_aff (DR_REF (a), &off1, &size1); | |
1329 | get_inner_reference_aff (DR_REF (b), &off2, &size2); | |
1330 | aff_combination_scale (&off1, double_int_minus_one); | |
1331 | aff_combination_add (&off2, &off1); | |
1332 | if (aff_comb_cannot_overlap_p (&off2, size1, size2)) | |
1333 | return false; | |
1334 | } | |
1335 | ||
c4ddde1b RG |
1336 | /* If we had an evolution in a MEM_REF BASE_OBJECT we do not know |
1337 | the size of the base-object. So we cannot do any offset/overlap | |
1338 | based analysis but have to rely on points-to information only. */ | |
1339 | if (TREE_CODE (addr_a) == MEM_REF | |
1340 | && DR_UNCONSTRAINED_BASE (a)) | |
1341 | { | |
1342 | if (TREE_CODE (addr_b) == MEM_REF | |
1343 | && DR_UNCONSTRAINED_BASE (b)) | |
1344 | return ptr_derefs_may_alias_p (TREE_OPERAND (addr_a, 0), | |
1345 | TREE_OPERAND (addr_b, 0)); | |
1346 | else | |
1347 | return ptr_derefs_may_alias_p (TREE_OPERAND (addr_a, 0), | |
1348 | build_fold_addr_expr (addr_b)); | |
1349 | } | |
1350 | else if (TREE_CODE (addr_b) == MEM_REF | |
1351 | && DR_UNCONSTRAINED_BASE (b)) | |
1352 | return ptr_derefs_may_alias_p (build_fold_addr_expr (addr_a), | |
1353 | TREE_OPERAND (addr_b, 0)); | |
1354 | ||
1355 | /* Otherwise DR_BASE_OBJECT is an access that covers the whole object | |
1356 | that is being subsetted in the loop nest. */ | |
b0af49c4 | 1357 | if (DR_IS_WRITE (a) && DR_IS_WRITE (b)) |
7d36e538 | 1358 | return refs_output_dependent_p (addr_a, addr_b); |
b0af49c4 | 1359 | else if (DR_IS_READ (a) && DR_IS_WRITE (b)) |
7d36e538 RG |
1360 | return refs_anti_dependent_p (addr_a, addr_b); |
1361 | return refs_may_alias_p (addr_a, addr_b); | |
3cb960c7 ZD |
1362 | } |
1363 | ||
0ff4040e SP |
1364 | /* Initialize a data dependence relation between data accesses A and |
1365 | B. NB_LOOPS is the number of loops surrounding the references: the | |
1366 | size of the classic distance/direction vectors. */ | |
56cf8686 | 1367 | |
aec7ae7d | 1368 | struct data_dependence_relation * |
b8698a0f | 1369 | initialize_data_dependence_relation (struct data_reference *a, |
0ff4040e | 1370 | struct data_reference *b, |
ba42e045 | 1371 | VEC (loop_p, heap) *loop_nest) |
56cf8686 SP |
1372 | { |
1373 | struct data_dependence_relation *res; | |
0ff4040e | 1374 | unsigned int i; |
b8698a0f | 1375 | |
5ed6ace5 | 1376 | res = XNEW (struct data_dependence_relation); |
56cf8686 SP |
1377 | DDR_A (res) = a; |
1378 | DDR_B (res) = b; | |
3ac57120 | 1379 | DDR_LOOP_NEST (res) = NULL; |
71d5b5e1 | 1380 | DDR_REVERSED_P (res) = false; |
2f470326 JJ |
1381 | DDR_SUBSCRIPTS (res) = NULL; |
1382 | DDR_DIR_VECTS (res) = NULL; | |
1383 | DDR_DIST_VECTS (res) = NULL; | |
56cf8686 | 1384 | |
86a07404 IR |
1385 | if (a == NULL || b == NULL) |
1386 | { | |
b8698a0f | 1387 | DDR_ARE_DEPENDENT (res) = chrec_dont_know; |
86a07404 | 1388 | return res; |
b8698a0f | 1389 | } |
86a07404 | 1390 | |
3cb960c7 | 1391 | /* If the data references do not alias, then they are independent. */ |
02f5d6c5 | 1392 | if (!dr_may_alias_p (a, b, loop_nest != NULL)) |
86a07404 | 1393 | { |
b8698a0f | 1394 | DDR_ARE_DEPENDENT (res) = chrec_known; |
86a07404 IR |
1395 | return res; |
1396 | } | |
56cf8686 | 1397 | |
fea99a37 | 1398 | /* The case where the references are exactly the same. */ |
b3924be9 SP |
1399 | if (operand_equal_p (DR_REF (a), DR_REF (b), 0)) |
1400 | { | |
1a4571cb RL |
1401 | if (loop_nest |
1402 | && !object_address_invariant_in_loop_p (VEC_index (loop_p, loop_nest, 0), | |
1403 | DR_BASE_OBJECT (a))) | |
1404 | { | |
1405 | DDR_ARE_DEPENDENT (res) = chrec_dont_know; | |
1406 | return res; | |
1407 | } | |
b3924be9 SP |
1408 | DDR_AFFINE_P (res) = true; |
1409 | DDR_ARE_DEPENDENT (res) = NULL_TREE; | |
1410 | DDR_SUBSCRIPTS (res) = VEC_alloc (subscript_p, heap, DR_NUM_DIMENSIONS (a)); | |
1411 | DDR_LOOP_NEST (res) = loop_nest; | |
1412 | DDR_INNER_LOOP (res) = 0; | |
1413 | DDR_SELF_REFERENCE (res) = true; | |
1a4571cb RL |
1414 | for (i = 0; i < DR_NUM_DIMENSIONS (a); i++) |
1415 | { | |
1416 | struct subscript *subscript; | |
1417 | ||
1418 | subscript = XNEW (struct subscript); | |
1419 | SUB_CONFLICTS_IN_A (subscript) = conflict_fn_not_known (); | |
1420 | SUB_CONFLICTS_IN_B (subscript) = conflict_fn_not_known (); | |
1421 | SUB_LAST_CONFLICT (subscript) = chrec_dont_know; | |
1422 | SUB_DISTANCE (subscript) = chrec_dont_know; | |
1423 | VEC_safe_push (subscript_p, heap, DDR_SUBSCRIPTS (res), subscript); | |
1424 | } | |
b3924be9 SP |
1425 | return res; |
1426 | } | |
1427 | ||
3cb960c7 ZD |
1428 | /* If the references do not access the same object, we do not know |
1429 | whether they alias or not. */ | |
1430 | if (!operand_equal_p (DR_BASE_OBJECT (a), DR_BASE_OBJECT (b), 0)) | |
56cf8686 | 1431 | { |
b8698a0f | 1432 | DDR_ARE_DEPENDENT (res) = chrec_dont_know; |
86a07404 IR |
1433 | return res; |
1434 | } | |
0ff4040e | 1435 | |
3cb960c7 | 1436 | /* If the base of the object is not invariant in the loop nest, we cannot |
0d52bcc1 | 1437 | analyze it. TODO -- in fact, it would suffice to record that there may |
c80b4100 | 1438 | be arbitrary dependences in the loops where the base object varies. */ |
b8698a0f | 1439 | if (loop_nest |
a70d6342 IR |
1440 | && !object_address_invariant_in_loop_p (VEC_index (loop_p, loop_nest, 0), |
1441 | DR_BASE_OBJECT (a))) | |
86a07404 | 1442 | { |
b8698a0f | 1443 | DDR_ARE_DEPENDENT (res) = chrec_dont_know; |
86a07404 IR |
1444 | return res; |
1445 | } | |
3cb960c7 | 1446 | |
19368333 RG |
1447 | /* If the number of dimensions of the access to not agree we can have |
1448 | a pointer access to a component of the array element type and an | |
1449 | array access while the base-objects are still the same. Punt. */ | |
1450 | if (DR_NUM_DIMENSIONS (a) != DR_NUM_DIMENSIONS (b)) | |
1451 | { | |
1452 | DDR_ARE_DEPENDENT (res) = chrec_dont_know; | |
1453 | return res; | |
1454 | } | |
3cb960c7 | 1455 | |
86a07404 IR |
1456 | DDR_AFFINE_P (res) = true; |
1457 | DDR_ARE_DEPENDENT (res) = NULL_TREE; | |
ebf78a47 | 1458 | DDR_SUBSCRIPTS (res) = VEC_alloc (subscript_p, heap, DR_NUM_DIMENSIONS (a)); |
ba42e045 | 1459 | DDR_LOOP_NEST (res) = loop_nest; |
3d8864c0 | 1460 | DDR_INNER_LOOP (res) = 0; |
b3924be9 | 1461 | DDR_SELF_REFERENCE (res) = false; |
304afda6 | 1462 | |
86a07404 IR |
1463 | for (i = 0; i < DR_NUM_DIMENSIONS (a); i++) |
1464 | { | |
1465 | struct subscript *subscript; | |
b8698a0f | 1466 | |
5ed6ace5 | 1467 | subscript = XNEW (struct subscript); |
d93817c4 ZD |
1468 | SUB_CONFLICTS_IN_A (subscript) = conflict_fn_not_known (); |
1469 | SUB_CONFLICTS_IN_B (subscript) = conflict_fn_not_known (); | |
86a07404 IR |
1470 | SUB_LAST_CONFLICT (subscript) = chrec_dont_know; |
1471 | SUB_DISTANCE (subscript) = chrec_dont_know; | |
ebf78a47 | 1472 | VEC_safe_push (subscript_p, heap, DDR_SUBSCRIPTS (res), subscript); |
56cf8686 | 1473 | } |
ebf78a47 | 1474 | |
56cf8686 SP |
1475 | return res; |
1476 | } | |
1477 | ||
d93817c4 ZD |
1478 | /* Frees memory used by the conflict function F. */ |
1479 | ||
1480 | static void | |
1481 | free_conflict_function (conflict_function *f) | |
1482 | { | |
1483 | unsigned i; | |
1484 | ||
1485 | if (CF_NONTRIVIAL_P (f)) | |
1486 | { | |
1487 | for (i = 0; i < f->n; i++) | |
1488 | affine_fn_free (f->fns[i]); | |
1489 | } | |
1490 | free (f); | |
1491 | } | |
1492 | ||
1493 | /* Frees memory used by SUBSCRIPTS. */ | |
1494 | ||
1495 | static void | |
1496 | free_subscripts (VEC (subscript_p, heap) *subscripts) | |
1497 | { | |
1498 | unsigned i; | |
1499 | subscript_p s; | |
1500 | ||
ac47786e | 1501 | FOR_EACH_VEC_ELT (subscript_p, subscripts, i, s) |
d93817c4 ZD |
1502 | { |
1503 | free_conflict_function (s->conflicting_iterations_in_a); | |
1504 | free_conflict_function (s->conflicting_iterations_in_b); | |
a0044be5 | 1505 | free (s); |
d93817c4 ZD |
1506 | } |
1507 | VEC_free (subscript_p, heap, subscripts); | |
1508 | } | |
1509 | ||
56cf8686 SP |
1510 | /* Set DDR_ARE_DEPENDENT to CHREC and finalize the subscript overlap |
1511 | description. */ | |
1512 | ||
1513 | static inline void | |
b8698a0f | 1514 | finalize_ddr_dependent (struct data_dependence_relation *ddr, |
56cf8686 SP |
1515 | tree chrec) |
1516 | { | |
36d59cf7 DB |
1517 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1518 | { | |
1519 | fprintf (dump_file, "(dependence classified: "); | |
1520 | print_generic_expr (dump_file, chrec, 0); | |
1521 | fprintf (dump_file, ")\n"); | |
1522 | } | |
1523 | ||
b8698a0f | 1524 | DDR_ARE_DEPENDENT (ddr) = chrec; |
d93817c4 | 1525 | free_subscripts (DDR_SUBSCRIPTS (ddr)); |
2f470326 | 1526 | DDR_SUBSCRIPTS (ddr) = NULL; |
56cf8686 SP |
1527 | } |
1528 | ||
86df10e3 SP |
1529 | /* The dependence relation DDR cannot be represented by a distance |
1530 | vector. */ | |
1531 | ||
1532 | static inline void | |
1533 | non_affine_dependence_relation (struct data_dependence_relation *ddr) | |
1534 | { | |
1535 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1536 | fprintf (dump_file, "(Dependence relation cannot be represented by distance vector.) \n"); | |
1537 | ||
1538 | DDR_AFFINE_P (ddr) = false; | |
1539 | } | |
1540 | ||
56cf8686 SP |
1541 | \f |
1542 | ||
1543 | /* This section contains the classic Banerjee tests. */ | |
1544 | ||
1545 | /* Returns true iff CHREC_A and CHREC_B are not dependent on any index | |
1546 | variables, i.e., if the ZIV (Zero Index Variable) test is true. */ | |
1547 | ||
1548 | static inline bool | |
ed7a4b4b | 1549 | ziv_subscript_p (const_tree chrec_a, const_tree chrec_b) |
56cf8686 SP |
1550 | { |
1551 | return (evolution_function_is_constant_p (chrec_a) | |
1552 | && evolution_function_is_constant_p (chrec_b)); | |
1553 | } | |
1554 | ||
1555 | /* Returns true iff CHREC_A and CHREC_B are dependent on an index | |
1556 | variable, i.e., if the SIV (Single Index Variable) test is true. */ | |
1557 | ||
1558 | static bool | |
ed7a4b4b | 1559 | siv_subscript_p (const_tree chrec_a, const_tree chrec_b) |
56cf8686 SP |
1560 | { |
1561 | if ((evolution_function_is_constant_p (chrec_a) | |
1562 | && evolution_function_is_univariate_p (chrec_b)) | |
1563 | || (evolution_function_is_constant_p (chrec_b) | |
1564 | && evolution_function_is_univariate_p (chrec_a))) | |
1565 | return true; | |
b8698a0f | 1566 | |
56cf8686 SP |
1567 | if (evolution_function_is_univariate_p (chrec_a) |
1568 | && evolution_function_is_univariate_p (chrec_b)) | |
1569 | { | |
1570 | switch (TREE_CODE (chrec_a)) | |
1571 | { | |
1572 | case POLYNOMIAL_CHREC: | |
1573 | switch (TREE_CODE (chrec_b)) | |
1574 | { | |
1575 | case POLYNOMIAL_CHREC: | |
1576 | if (CHREC_VARIABLE (chrec_a) != CHREC_VARIABLE (chrec_b)) | |
1577 | return false; | |
b8698a0f | 1578 | |
56cf8686 SP |
1579 | default: |
1580 | return true; | |
1581 | } | |
b8698a0f | 1582 | |
56cf8686 SP |
1583 | default: |
1584 | return true; | |
1585 | } | |
1586 | } | |
b8698a0f | 1587 | |
56cf8686 SP |
1588 | return false; |
1589 | } | |
1590 | ||
d93817c4 ZD |
1591 | /* Creates a conflict function with N dimensions. The affine functions |
1592 | in each dimension follow. */ | |
1593 | ||
1594 | static conflict_function * | |
1595 | conflict_fn (unsigned n, ...) | |
1596 | { | |
1597 | unsigned i; | |
1598 | conflict_function *ret = XCNEW (conflict_function); | |
1599 | va_list ap; | |
1600 | ||
b39c6706 | 1601 | gcc_assert (0 < n && n <= MAX_DIM); |
d93817c4 | 1602 | va_start(ap, n); |
b8698a0f | 1603 | |
d93817c4 ZD |
1604 | ret->n = n; |
1605 | for (i = 0; i < n; i++) | |
1606 | ret->fns[i] = va_arg (ap, affine_fn); | |
1607 | va_end(ap); | |
1608 | ||
1609 | return ret; | |
1610 | } | |
1611 | ||
1612 | /* Returns constant affine function with value CST. */ | |
1613 | ||
1614 | static affine_fn | |
1615 | affine_fn_cst (tree cst) | |
1616 | { | |
1617 | affine_fn fn = VEC_alloc (tree, heap, 1); | |
1618 | VEC_quick_push (tree, fn, cst); | |
1619 | return fn; | |
1620 | } | |
1621 | ||
1622 | /* Returns affine function with single variable, CST + COEF * x_DIM. */ | |
1623 | ||
1624 | static affine_fn | |
1625 | affine_fn_univar (tree cst, unsigned dim, tree coef) | |
1626 | { | |
1627 | affine_fn fn = VEC_alloc (tree, heap, dim + 1); | |
1628 | unsigned i; | |
1629 | ||
1630 | gcc_assert (dim > 0); | |
1631 | VEC_quick_push (tree, fn, cst); | |
1632 | for (i = 1; i < dim; i++) | |
1633 | VEC_quick_push (tree, fn, integer_zero_node); | |
1634 | VEC_quick_push (tree, fn, coef); | |
1635 | return fn; | |
1636 | } | |
1637 | ||
56cf8686 SP |
1638 | /* Analyze a ZIV (Zero Index Variable) subscript. *OVERLAPS_A and |
1639 | *OVERLAPS_B are initialized to the functions that describe the | |
1640 | relation between the elements accessed twice by CHREC_A and | |
1641 | CHREC_B. For k >= 0, the following property is verified: | |
1642 | ||
1643 | CHREC_A (*OVERLAPS_A (k)) = CHREC_B (*OVERLAPS_B (k)). */ | |
1644 | ||
b8698a0f L |
1645 | static void |
1646 | analyze_ziv_subscript (tree chrec_a, | |
1647 | tree chrec_b, | |
d93817c4 | 1648 | conflict_function **overlaps_a, |
b8698a0f | 1649 | conflict_function **overlaps_b, |
86df10e3 | 1650 | tree *last_conflicts) |
56cf8686 | 1651 | { |
33b30201 | 1652 | tree type, difference; |
0ff4040e | 1653 | dependence_stats.num_ziv++; |
b8698a0f | 1654 | |
56cf8686 SP |
1655 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1656 | fprintf (dump_file, "(analyze_ziv_subscript \n"); | |
33b30201 SP |
1657 | |
1658 | type = signed_type_for_types (TREE_TYPE (chrec_a), TREE_TYPE (chrec_b)); | |
726a989a RB |
1659 | chrec_a = chrec_convert (type, chrec_a, NULL); |
1660 | chrec_b = chrec_convert (type, chrec_b, NULL); | |
33b30201 | 1661 | difference = chrec_fold_minus (type, chrec_a, chrec_b); |
b8698a0f | 1662 | |
56cf8686 SP |
1663 | switch (TREE_CODE (difference)) |
1664 | { | |
1665 | case INTEGER_CST: | |
1666 | if (integer_zerop (difference)) | |
1667 | { | |
1668 | /* The difference is equal to zero: the accessed index | |
1669 | overlaps for each iteration in the loop. */ | |
d93817c4 ZD |
1670 | *overlaps_a = conflict_fn (1, affine_fn_cst (integer_zero_node)); |
1671 | *overlaps_b = conflict_fn (1, affine_fn_cst (integer_zero_node)); | |
86df10e3 | 1672 | *last_conflicts = chrec_dont_know; |
0ff4040e | 1673 | dependence_stats.num_ziv_dependent++; |
56cf8686 SP |
1674 | } |
1675 | else | |
1676 | { | |
1677 | /* The accesses do not overlap. */ | |
d93817c4 ZD |
1678 | *overlaps_a = conflict_fn_no_dependence (); |
1679 | *overlaps_b = conflict_fn_no_dependence (); | |
86df10e3 | 1680 | *last_conflicts = integer_zero_node; |
0ff4040e | 1681 | dependence_stats.num_ziv_independent++; |
56cf8686 SP |
1682 | } |
1683 | break; | |
b8698a0f | 1684 | |
56cf8686 | 1685 | default: |
b8698a0f | 1686 | /* We're not sure whether the indexes overlap. For the moment, |
56cf8686 | 1687 | conservatively answer "don't know". */ |
0ff4040e SP |
1688 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1689 | fprintf (dump_file, "ziv test failed: difference is non-integer.\n"); | |
1690 | ||
d93817c4 ZD |
1691 | *overlaps_a = conflict_fn_not_known (); |
1692 | *overlaps_b = conflict_fn_not_known (); | |
86df10e3 | 1693 | *last_conflicts = chrec_dont_know; |
0ff4040e | 1694 | dependence_stats.num_ziv_unimplemented++; |
56cf8686 SP |
1695 | break; |
1696 | } | |
b8698a0f | 1697 | |
56cf8686 SP |
1698 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1699 | fprintf (dump_file, ")\n"); | |
1700 | } | |
1701 | ||
b4a9343c | 1702 | /* Similar to max_stmt_executions_int, but returns the bound as a tree, |
4839cb59 | 1703 | and only if it fits to the int type. If this is not the case, or the |
b4a9343c | 1704 | bound on the number of iterations of LOOP could not be derived, returns |
4839cb59 ZD |
1705 | chrec_dont_know. */ |
1706 | ||
1707 | static tree | |
b4a9343c | 1708 | max_stmt_executions_tree (struct loop *loop) |
4839cb59 ZD |
1709 | { |
1710 | double_int nit; | |
4839cb59 | 1711 | |
652c4c71 | 1712 | if (!max_stmt_executions (loop, &nit)) |
4839cb59 ZD |
1713 | return chrec_dont_know; |
1714 | ||
5f72e02d | 1715 | if (!double_int_fits_to_tree_p (unsigned_type_node, nit)) |
4839cb59 ZD |
1716 | return chrec_dont_know; |
1717 | ||
5f72e02d | 1718 | return double_int_to_tree (unsigned_type_node, nit); |
4839cb59 ZD |
1719 | } |
1720 | ||
5f1fab58 RG |
1721 | /* Determine whether the CHREC is always positive/negative. If the expression |
1722 | cannot be statically analyzed, return false, otherwise set the answer into | |
1723 | VALUE. */ | |
1724 | ||
1725 | static bool | |
1726 | chrec_is_positive (tree chrec, bool *value) | |
1727 | { | |
1728 | bool value0, value1, value2; | |
1729 | tree end_value, nb_iter; | |
1730 | ||
1731 | switch (TREE_CODE (chrec)) | |
1732 | { | |
1733 | case POLYNOMIAL_CHREC: | |
1734 | if (!chrec_is_positive (CHREC_LEFT (chrec), &value0) | |
1735 | || !chrec_is_positive (CHREC_RIGHT (chrec), &value1)) | |
1736 | return false; | |
1737 | ||
1738 | /* FIXME -- overflows. */ | |
1739 | if (value0 == value1) | |
1740 | { | |
1741 | *value = value0; | |
1742 | return true; | |
1743 | } | |
1744 | ||
1745 | /* Otherwise the chrec is under the form: "{-197, +, 2}_1", | |
1746 | and the proof consists in showing that the sign never | |
1747 | changes during the execution of the loop, from 0 to | |
1748 | loop->nb_iterations. */ | |
1749 | if (!evolution_function_is_affine_p (chrec)) | |
1750 | return false; | |
1751 | ||
1752 | nb_iter = number_of_latch_executions (get_chrec_loop (chrec)); | |
1753 | if (chrec_contains_undetermined (nb_iter)) | |
1754 | return false; | |
1755 | ||
1756 | #if 0 | |
1757 | /* TODO -- If the test is after the exit, we may decrease the number of | |
1758 | iterations by one. */ | |
1759 | if (after_exit) | |
1760 | nb_iter = chrec_fold_minus (type, nb_iter, build_int_cst (type, 1)); | |
1761 | #endif | |
1762 | ||
1763 | end_value = chrec_apply (CHREC_VARIABLE (chrec), chrec, nb_iter); | |
1764 | ||
1765 | if (!chrec_is_positive (end_value, &value2)) | |
1766 | return false; | |
1767 | ||
1768 | *value = value0; | |
1769 | return value0 == value1; | |
1770 | ||
1771 | case INTEGER_CST: | |
1772 | switch (tree_int_cst_sgn (chrec)) | |
1773 | { | |
1774 | case -1: | |
1775 | *value = false; | |
1776 | break; | |
1777 | case 1: | |
1778 | *value = true; | |
1779 | break; | |
1780 | default: | |
1781 | return false; | |
1782 | } | |
1783 | return true; | |
1784 | ||
1785 | default: | |
1786 | return false; | |
1787 | } | |
1788 | } | |
1789 | ||
1790 | ||
56cf8686 SP |
1791 | /* Analyze a SIV (Single Index Variable) subscript where CHREC_A is a |
1792 | constant, and CHREC_B is an affine function. *OVERLAPS_A and | |
1793 | *OVERLAPS_B are initialized to the functions that describe the | |
1794 | relation between the elements accessed twice by CHREC_A and | |
1795 | CHREC_B. For k >= 0, the following property is verified: | |
1796 | ||
1797 | CHREC_A (*OVERLAPS_A (k)) = CHREC_B (*OVERLAPS_B (k)). */ | |
1798 | ||
1799 | static void | |
b8698a0f | 1800 | analyze_siv_subscript_cst_affine (tree chrec_a, |
56cf8686 | 1801 | tree chrec_b, |
b8698a0f L |
1802 | conflict_function **overlaps_a, |
1803 | conflict_function **overlaps_b, | |
86df10e3 | 1804 | tree *last_conflicts) |
56cf8686 SP |
1805 | { |
1806 | bool value0, value1, value2; | |
33b30201 | 1807 | tree type, difference, tmp; |
e2157b49 | 1808 | |
33b30201 | 1809 | type = signed_type_for_types (TREE_TYPE (chrec_a), TREE_TYPE (chrec_b)); |
726a989a RB |
1810 | chrec_a = chrec_convert (type, chrec_a, NULL); |
1811 | chrec_b = chrec_convert (type, chrec_b, NULL); | |
33b30201 | 1812 | difference = chrec_fold_minus (type, initial_condition (chrec_b), chrec_a); |
b8698a0f | 1813 | |
5f1fab58 RG |
1814 | /* Special case overlap in the first iteration. */ |
1815 | if (integer_zerop (difference)) | |
1816 | { | |
1817 | *overlaps_a = conflict_fn (1, affine_fn_cst (integer_zero_node)); | |
1818 | *overlaps_b = conflict_fn (1, affine_fn_cst (integer_zero_node)); | |
1819 | *last_conflicts = integer_one_node; | |
1820 | return; | |
1821 | } | |
1822 | ||
56cf8686 SP |
1823 | if (!chrec_is_positive (initial_condition (difference), &value0)) |
1824 | { | |
0ff4040e | 1825 | if (dump_file && (dump_flags & TDF_DETAILS)) |
b8698a0f | 1826 | fprintf (dump_file, "siv test failed: chrec is not positive.\n"); |
0ff4040e SP |
1827 | |
1828 | dependence_stats.num_siv_unimplemented++; | |
d93817c4 ZD |
1829 | *overlaps_a = conflict_fn_not_known (); |
1830 | *overlaps_b = conflict_fn_not_known (); | |
86df10e3 | 1831 | *last_conflicts = chrec_dont_know; |
56cf8686 SP |
1832 | return; |
1833 | } | |
1834 | else | |
1835 | { | |
1836 | if (value0 == false) | |
1837 | { | |
1838 | if (!chrec_is_positive (CHREC_RIGHT (chrec_b), &value1)) | |
1839 | { | |
0ff4040e SP |
1840 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1841 | fprintf (dump_file, "siv test failed: chrec not positive.\n"); | |
1842 | ||
d93817c4 | 1843 | *overlaps_a = conflict_fn_not_known (); |
b8698a0f | 1844 | *overlaps_b = conflict_fn_not_known (); |
86df10e3 | 1845 | *last_conflicts = chrec_dont_know; |
0ff4040e | 1846 | dependence_stats.num_siv_unimplemented++; |
56cf8686 SP |
1847 | return; |
1848 | } | |
1849 | else | |
1850 | { | |
1851 | if (value1 == true) | |
1852 | { | |
b8698a0f | 1853 | /* Example: |
56cf8686 SP |
1854 | chrec_a = 12 |
1855 | chrec_b = {10, +, 1} | |
1856 | */ | |
b8698a0f | 1857 | |
f457cf40 | 1858 | if (tree_fold_divides_p (CHREC_RIGHT (chrec_b), difference)) |
56cf8686 | 1859 | { |
4839cb59 ZD |
1860 | HOST_WIDE_INT numiter; |
1861 | struct loop *loop = get_chrec_loop (chrec_b); | |
416f403e | 1862 | |
d93817c4 | 1863 | *overlaps_a = conflict_fn (1, affine_fn_cst (integer_zero_node)); |
33b30201 SP |
1864 | tmp = fold_build2 (EXACT_DIV_EXPR, type, |
1865 | fold_build1 (ABS_EXPR, type, difference), | |
d93817c4 ZD |
1866 | CHREC_RIGHT (chrec_b)); |
1867 | *overlaps_b = conflict_fn (1, affine_fn_cst (tmp)); | |
86df10e3 | 1868 | *last_conflicts = integer_one_node; |
b8698a0f | 1869 | |
416f403e DB |
1870 | |
1871 | /* Perform weak-zero siv test to see if overlap is | |
1872 | outside the loop bounds. */ | |
652c4c71 | 1873 | numiter = max_stmt_executions_int (loop); |
416f403e | 1874 | |
4839cb59 ZD |
1875 | if (numiter >= 0 |
1876 | && compare_tree_int (tmp, numiter) > 0) | |
416f403e | 1877 | { |
d93817c4 ZD |
1878 | free_conflict_function (*overlaps_a); |
1879 | free_conflict_function (*overlaps_b); | |
1880 | *overlaps_a = conflict_fn_no_dependence (); | |
1881 | *overlaps_b = conflict_fn_no_dependence (); | |
416f403e | 1882 | *last_conflicts = integer_zero_node; |
0ff4040e | 1883 | dependence_stats.num_siv_independent++; |
416f403e | 1884 | return; |
b8698a0f | 1885 | } |
0ff4040e | 1886 | dependence_stats.num_siv_dependent++; |
56cf8686 SP |
1887 | return; |
1888 | } | |
b8698a0f | 1889 | |
f457cf40 | 1890 | /* When the step does not divide the difference, there are |
56cf8686 SP |
1891 | no overlaps. */ |
1892 | else | |
1893 | { | |
d93817c4 | 1894 | *overlaps_a = conflict_fn_no_dependence (); |
b8698a0f | 1895 | *overlaps_b = conflict_fn_no_dependence (); |
86df10e3 | 1896 | *last_conflicts = integer_zero_node; |
0ff4040e | 1897 | dependence_stats.num_siv_independent++; |
56cf8686 SP |
1898 | return; |
1899 | } | |
1900 | } | |
b8698a0f | 1901 | |
56cf8686 SP |
1902 | else |
1903 | { | |
b8698a0f | 1904 | /* Example: |
56cf8686 SP |
1905 | chrec_a = 12 |
1906 | chrec_b = {10, +, -1} | |
b8698a0f | 1907 | |
56cf8686 | 1908 | In this case, chrec_a will not overlap with chrec_b. */ |
d93817c4 ZD |
1909 | *overlaps_a = conflict_fn_no_dependence (); |
1910 | *overlaps_b = conflict_fn_no_dependence (); | |
86df10e3 | 1911 | *last_conflicts = integer_zero_node; |
0ff4040e | 1912 | dependence_stats.num_siv_independent++; |
56cf8686 SP |
1913 | return; |
1914 | } | |
1915 | } | |
1916 | } | |
b8698a0f | 1917 | else |
56cf8686 SP |
1918 | { |
1919 | if (!chrec_is_positive (CHREC_RIGHT (chrec_b), &value2)) | |
1920 | { | |
0ff4040e SP |
1921 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1922 | fprintf (dump_file, "siv test failed: chrec not positive.\n"); | |
1923 | ||
d93817c4 | 1924 | *overlaps_a = conflict_fn_not_known (); |
b8698a0f | 1925 | *overlaps_b = conflict_fn_not_known (); |
86df10e3 | 1926 | *last_conflicts = chrec_dont_know; |
0ff4040e | 1927 | dependence_stats.num_siv_unimplemented++; |
56cf8686 SP |
1928 | return; |
1929 | } | |
1930 | else | |
1931 | { | |
1932 | if (value2 == false) | |
1933 | { | |
b8698a0f | 1934 | /* Example: |
56cf8686 SP |
1935 | chrec_a = 3 |
1936 | chrec_b = {10, +, -1} | |
1937 | */ | |
f457cf40 | 1938 | if (tree_fold_divides_p (CHREC_RIGHT (chrec_b), difference)) |
56cf8686 | 1939 | { |
4839cb59 ZD |
1940 | HOST_WIDE_INT numiter; |
1941 | struct loop *loop = get_chrec_loop (chrec_b); | |
416f403e | 1942 | |
d93817c4 | 1943 | *overlaps_a = conflict_fn (1, affine_fn_cst (integer_zero_node)); |
33b30201 | 1944 | tmp = fold_build2 (EXACT_DIV_EXPR, type, difference, |
d93817c4 ZD |
1945 | CHREC_RIGHT (chrec_b)); |
1946 | *overlaps_b = conflict_fn (1, affine_fn_cst (tmp)); | |
86df10e3 | 1947 | *last_conflicts = integer_one_node; |
416f403e DB |
1948 | |
1949 | /* Perform weak-zero siv test to see if overlap is | |
1950 | outside the loop bounds. */ | |
652c4c71 | 1951 | numiter = max_stmt_executions_int (loop); |
416f403e | 1952 | |
4839cb59 ZD |
1953 | if (numiter >= 0 |
1954 | && compare_tree_int (tmp, numiter) > 0) | |
416f403e | 1955 | { |
d93817c4 ZD |
1956 | free_conflict_function (*overlaps_a); |
1957 | free_conflict_function (*overlaps_b); | |
1958 | *overlaps_a = conflict_fn_no_dependence (); | |
1959 | *overlaps_b = conflict_fn_no_dependence (); | |
416f403e | 1960 | *last_conflicts = integer_zero_node; |
0ff4040e | 1961 | dependence_stats.num_siv_independent++; |
416f403e | 1962 | return; |
b8698a0f | 1963 | } |
0ff4040e | 1964 | dependence_stats.num_siv_dependent++; |
56cf8686 SP |
1965 | return; |
1966 | } | |
b8698a0f | 1967 | |
4286d8ce | 1968 | /* When the step does not divide the difference, there |
56cf8686 SP |
1969 | are no overlaps. */ |
1970 | else | |
1971 | { | |
d93817c4 | 1972 | *overlaps_a = conflict_fn_no_dependence (); |
b8698a0f | 1973 | *overlaps_b = conflict_fn_no_dependence (); |
86df10e3 | 1974 | *last_conflicts = integer_zero_node; |
0ff4040e | 1975 | dependence_stats.num_siv_independent++; |
56cf8686 SP |
1976 | return; |
1977 | } | |
1978 | } | |
1979 | else | |
1980 | { | |
b8698a0f L |
1981 | /* Example: |
1982 | chrec_a = 3 | |
56cf8686 | 1983 | chrec_b = {4, +, 1} |
b8698a0f | 1984 | |
56cf8686 | 1985 | In this case, chrec_a will not overlap with chrec_b. */ |
d93817c4 ZD |
1986 | *overlaps_a = conflict_fn_no_dependence (); |
1987 | *overlaps_b = conflict_fn_no_dependence (); | |
86df10e3 | 1988 | *last_conflicts = integer_zero_node; |
0ff4040e | 1989 | dependence_stats.num_siv_independent++; |
56cf8686 SP |
1990 | return; |
1991 | } | |
1992 | } | |
1993 | } | |
1994 | } | |
1995 | } | |
1996 | ||
50300b4c | 1997 | /* Helper recursive function for initializing the matrix A. Returns |
86df10e3 | 1998 | the initial value of CHREC. */ |
56cf8686 | 1999 | |
5b78fc3e | 2000 | static tree |
86df10e3 SP |
2001 | initialize_matrix_A (lambda_matrix A, tree chrec, unsigned index, int mult) |
2002 | { | |
2003 | gcc_assert (chrec); | |
2004 | ||
5b78fc3e JS |
2005 | switch (TREE_CODE (chrec)) |
2006 | { | |
2007 | case POLYNOMIAL_CHREC: | |
2008 | gcc_assert (TREE_CODE (CHREC_RIGHT (chrec)) == INTEGER_CST); | |
2009 | ||
2010 | A[index][0] = mult * int_cst_value (CHREC_RIGHT (chrec)); | |
2011 | return initialize_matrix_A (A, CHREC_LEFT (chrec), index + 1, mult); | |
2012 | ||
2013 | case PLUS_EXPR: | |
2014 | case MULT_EXPR: | |
2015 | case MINUS_EXPR: | |
2016 | { | |
2017 | tree op0 = initialize_matrix_A (A, TREE_OPERAND (chrec, 0), index, mult); | |
2018 | tree op1 = initialize_matrix_A (A, TREE_OPERAND (chrec, 1), index, mult); | |
2019 | ||
2020 | return chrec_fold_op (TREE_CODE (chrec), chrec_type (chrec), op0, op1); | |
2021 | } | |
2022 | ||
2023 | case NOP_EXPR: | |
2024 | { | |
2025 | tree op = initialize_matrix_A (A, TREE_OPERAND (chrec, 0), index, mult); | |
726a989a | 2026 | return chrec_convert (chrec_type (chrec), op, NULL); |
5b78fc3e JS |
2027 | } |
2028 | ||
418df9d7 JJ |
2029 | case BIT_NOT_EXPR: |
2030 | { | |
2031 | /* Handle ~X as -1 - X. */ | |
2032 | tree op = initialize_matrix_A (A, TREE_OPERAND (chrec, 0), index, mult); | |
2033 | return chrec_fold_op (MINUS_EXPR, chrec_type (chrec), | |
2034 | build_int_cst (TREE_TYPE (chrec), -1), op); | |
2035 | } | |
2036 | ||
5b78fc3e JS |
2037 | case INTEGER_CST: |
2038 | return chrec; | |
a1a5996d | 2039 | |
5b78fc3e JS |
2040 | default: |
2041 | gcc_unreachable (); | |
2042 | return NULL_TREE; | |
2043 | } | |
86df10e3 SP |
2044 | } |
2045 | ||
2046 | #define FLOOR_DIV(x,y) ((x) / (y)) | |
2047 | ||
b8698a0f | 2048 | /* Solves the special case of the Diophantine equation: |
86df10e3 SP |
2049 | | {0, +, STEP_A}_x (OVERLAPS_A) = {0, +, STEP_B}_y (OVERLAPS_B) |
2050 | ||
2051 | Computes the descriptions OVERLAPS_A and OVERLAPS_B. NITER is the | |
2052 | number of iterations that loops X and Y run. The overlaps will be | |
2053 | constructed as evolutions in dimension DIM. */ | |
56cf8686 SP |
2054 | |
2055 | static void | |
b8698a0f | 2056 | compute_overlap_steps_for_affine_univar (int niter, int step_a, int step_b, |
d93817c4 | 2057 | affine_fn *overlaps_a, |
b8698a0f | 2058 | affine_fn *overlaps_b, |
86df10e3 SP |
2059 | tree *last_conflicts, int dim) |
2060 | { | |
2061 | if (((step_a > 0 && step_b > 0) | |
2062 | || (step_a < 0 && step_b < 0))) | |
2063 | { | |
2064 | int step_overlaps_a, step_overlaps_b; | |
2065 | int gcd_steps_a_b, last_conflict, tau2; | |
2066 | ||
2067 | gcd_steps_a_b = gcd (step_a, step_b); | |
2068 | step_overlaps_a = step_b / gcd_steps_a_b; | |
2069 | step_overlaps_b = step_a / gcd_steps_a_b; | |
2070 | ||
2c26cbfd SP |
2071 | if (niter > 0) |
2072 | { | |
2073 | tau2 = FLOOR_DIV (niter, step_overlaps_a); | |
2074 | tau2 = MIN (tau2, FLOOR_DIV (niter, step_overlaps_b)); | |
2075 | last_conflict = tau2; | |
2076 | *last_conflicts = build_int_cst (NULL_TREE, last_conflict); | |
2077 | } | |
2078 | else | |
2079 | *last_conflicts = chrec_dont_know; | |
86df10e3 | 2080 | |
b8698a0f | 2081 | *overlaps_a = affine_fn_univar (integer_zero_node, dim, |
d93817c4 ZD |
2082 | build_int_cst (NULL_TREE, |
2083 | step_overlaps_a)); | |
b8698a0f L |
2084 | *overlaps_b = affine_fn_univar (integer_zero_node, dim, |
2085 | build_int_cst (NULL_TREE, | |
d93817c4 | 2086 | step_overlaps_b)); |
86df10e3 SP |
2087 | } |
2088 | ||
2089 | else | |
2090 | { | |
d93817c4 ZD |
2091 | *overlaps_a = affine_fn_cst (integer_zero_node); |
2092 | *overlaps_b = affine_fn_cst (integer_zero_node); | |
86df10e3 SP |
2093 | *last_conflicts = integer_zero_node; |
2094 | } | |
2095 | } | |
2096 | ||
86df10e3 SP |
2097 | /* Solves the special case of a Diophantine equation where CHREC_A is |
2098 | an affine bivariate function, and CHREC_B is an affine univariate | |
b8698a0f | 2099 | function. For example, |
86df10e3 SP |
2100 | |
2101 | | {{0, +, 1}_x, +, 1335}_y = {0, +, 1336}_z | |
b8698a0f L |
2102 | |
2103 | has the following overlapping functions: | |
86df10e3 SP |
2104 | |
2105 | | x (t, u, v) = {{0, +, 1336}_t, +, 1}_v | |
2106 | | y (t, u, v) = {{0, +, 1336}_u, +, 1}_v | |
2107 | | z (t, u, v) = {{{0, +, 1}_t, +, 1335}_u, +, 1}_v | |
2108 | ||
35fd3193 | 2109 | FORNOW: This is a specialized implementation for a case occurring in |
86df10e3 SP |
2110 | a common benchmark. Implement the general algorithm. */ |
2111 | ||
2112 | static void | |
b8698a0f | 2113 | compute_overlap_steps_for_affine_1_2 (tree chrec_a, tree chrec_b, |
d93817c4 | 2114 | conflict_function **overlaps_a, |
b8698a0f | 2115 | conflict_function **overlaps_b, |
86df10e3 | 2116 | tree *last_conflicts) |
56cf8686 | 2117 | { |
86df10e3 SP |
2118 | bool xz_p, yz_p, xyz_p; |
2119 | int step_x, step_y, step_z; | |
4839cb59 | 2120 | HOST_WIDE_INT niter_x, niter_y, niter_z, niter; |
d93817c4 ZD |
2121 | affine_fn overlaps_a_xz, overlaps_b_xz; |
2122 | affine_fn overlaps_a_yz, overlaps_b_yz; | |
2123 | affine_fn overlaps_a_xyz, overlaps_b_xyz; | |
2124 | affine_fn ova1, ova2, ovb; | |
2125 | tree last_conflicts_xz, last_conflicts_yz, last_conflicts_xyz; | |
86df10e3 | 2126 | |
6b6fa4e9 SP |
2127 | step_x = int_cst_value (CHREC_RIGHT (CHREC_LEFT (chrec_a))); |
2128 | step_y = int_cst_value (CHREC_RIGHT (chrec_a)); | |
2129 | step_z = int_cst_value (CHREC_RIGHT (chrec_b)); | |
86df10e3 | 2130 | |
652c4c71 RG |
2131 | niter_x = max_stmt_executions_int (get_chrec_loop (CHREC_LEFT (chrec_a))); |
2132 | niter_y = max_stmt_executions_int (get_chrec_loop (chrec_a)); | |
2133 | niter_z = max_stmt_executions_int (get_chrec_loop (chrec_b)); | |
b8698a0f | 2134 | |
4839cb59 | 2135 | if (niter_x < 0 || niter_y < 0 || niter_z < 0) |
86df10e3 | 2136 | { |
0ff4040e SP |
2137 | if (dump_file && (dump_flags & TDF_DETAILS)) |
2138 | fprintf (dump_file, "overlap steps test failed: no iteration counts.\n"); | |
b8698a0f | 2139 | |
d93817c4 ZD |
2140 | *overlaps_a = conflict_fn_not_known (); |
2141 | *overlaps_b = conflict_fn_not_known (); | |
86df10e3 SP |
2142 | *last_conflicts = chrec_dont_know; |
2143 | return; | |
2144 | } | |
2145 | ||
86df10e3 SP |
2146 | niter = MIN (niter_x, niter_z); |
2147 | compute_overlap_steps_for_affine_univar (niter, step_x, step_z, | |
2148 | &overlaps_a_xz, | |
2149 | &overlaps_b_xz, | |
2150 | &last_conflicts_xz, 1); | |
2151 | niter = MIN (niter_y, niter_z); | |
2152 | compute_overlap_steps_for_affine_univar (niter, step_y, step_z, | |
2153 | &overlaps_a_yz, | |
2154 | &overlaps_b_yz, | |
2155 | &last_conflicts_yz, 2); | |
2156 | niter = MIN (niter_x, niter_z); | |
2157 | niter = MIN (niter_y, niter); | |
2158 | compute_overlap_steps_for_affine_univar (niter, step_x + step_y, step_z, | |
2159 | &overlaps_a_xyz, | |
2160 | &overlaps_b_xyz, | |
2161 | &last_conflicts_xyz, 3); | |
2162 | ||
2163 | xz_p = !integer_zerop (last_conflicts_xz); | |
2164 | yz_p = !integer_zerop (last_conflicts_yz); | |
2165 | xyz_p = !integer_zerop (last_conflicts_xyz); | |
2166 | ||
2167 | if (xz_p || yz_p || xyz_p) | |
2168 | { | |
d93817c4 ZD |
2169 | ova1 = affine_fn_cst (integer_zero_node); |
2170 | ova2 = affine_fn_cst (integer_zero_node); | |
2171 | ovb = affine_fn_cst (integer_zero_node); | |
86df10e3 SP |
2172 | if (xz_p) |
2173 | { | |
d93817c4 ZD |
2174 | affine_fn t0 = ova1; |
2175 | affine_fn t2 = ovb; | |
2176 | ||
2177 | ova1 = affine_fn_plus (ova1, overlaps_a_xz); | |
2178 | ovb = affine_fn_plus (ovb, overlaps_b_xz); | |
2179 | affine_fn_free (t0); | |
2180 | affine_fn_free (t2); | |
86df10e3 SP |
2181 | *last_conflicts = last_conflicts_xz; |
2182 | } | |
2183 | if (yz_p) | |
2184 | { | |
d93817c4 ZD |
2185 | affine_fn t0 = ova2; |
2186 | affine_fn t2 = ovb; | |
2187 | ||
2188 | ova2 = affine_fn_plus (ova2, overlaps_a_yz); | |
2189 | ovb = affine_fn_plus (ovb, overlaps_b_yz); | |
2190 | affine_fn_free (t0); | |
2191 | affine_fn_free (t2); | |
86df10e3 SP |
2192 | *last_conflicts = last_conflicts_yz; |
2193 | } | |
2194 | if (xyz_p) | |
2195 | { | |
d93817c4 ZD |
2196 | affine_fn t0 = ova1; |
2197 | affine_fn t2 = ova2; | |
2198 | affine_fn t4 = ovb; | |
2199 | ||
2200 | ova1 = affine_fn_plus (ova1, overlaps_a_xyz); | |
2201 | ova2 = affine_fn_plus (ova2, overlaps_a_xyz); | |
2202 | ovb = affine_fn_plus (ovb, overlaps_b_xyz); | |
2203 | affine_fn_free (t0); | |
2204 | affine_fn_free (t2); | |
2205 | affine_fn_free (t4); | |
86df10e3 SP |
2206 | *last_conflicts = last_conflicts_xyz; |
2207 | } | |
d93817c4 ZD |
2208 | *overlaps_a = conflict_fn (2, ova1, ova2); |
2209 | *overlaps_b = conflict_fn (1, ovb); | |
86df10e3 SP |
2210 | } |
2211 | else | |
2212 | { | |
d93817c4 ZD |
2213 | *overlaps_a = conflict_fn (1, affine_fn_cst (integer_zero_node)); |
2214 | *overlaps_b = conflict_fn (1, affine_fn_cst (integer_zero_node)); | |
86df10e3 SP |
2215 | *last_conflicts = integer_zero_node; |
2216 | } | |
d93817c4 ZD |
2217 | |
2218 | affine_fn_free (overlaps_a_xz); | |
2219 | affine_fn_free (overlaps_b_xz); | |
2220 | affine_fn_free (overlaps_a_yz); | |
2221 | affine_fn_free (overlaps_b_yz); | |
2222 | affine_fn_free (overlaps_a_xyz); | |
2223 | affine_fn_free (overlaps_b_xyz); | |
56cf8686 SP |
2224 | } |
2225 | ||
b305e3da SP |
2226 | /* Copy the elements of vector VEC1 with length SIZE to VEC2. */ |
2227 | ||
2228 | static void | |
2229 | lambda_vector_copy (lambda_vector vec1, lambda_vector vec2, | |
2230 | int size) | |
2231 | { | |
2232 | memcpy (vec2, vec1, size * sizeof (*vec1)); | |
2233 | } | |
2234 | ||
2235 | /* Copy the elements of M x N matrix MAT1 to MAT2. */ | |
2236 | ||
2237 | static void | |
2238 | lambda_matrix_copy (lambda_matrix mat1, lambda_matrix mat2, | |
2239 | int m, int n) | |
2240 | { | |
2241 | int i; | |
2242 | ||
2243 | for (i = 0; i < m; i++) | |
2244 | lambda_vector_copy (mat1[i], mat2[i], n); | |
2245 | } | |
2246 | ||
2247 | /* Store the N x N identity matrix in MAT. */ | |
2248 | ||
2249 | static void | |
2250 | lambda_matrix_id (lambda_matrix mat, int size) | |
2251 | { | |
2252 | int i, j; | |
2253 | ||
2254 | for (i = 0; i < size; i++) | |
2255 | for (j = 0; j < size; j++) | |
2256 | mat[i][j] = (i == j) ? 1 : 0; | |
2257 | } | |
2258 | ||
2259 | /* Return the first nonzero element of vector VEC1 between START and N. | |
2260 | We must have START <= N. Returns N if VEC1 is the zero vector. */ | |
2261 | ||
2262 | static int | |
2263 | lambda_vector_first_nz (lambda_vector vec1, int n, int start) | |
2264 | { | |
2265 | int j = start; | |
2266 | while (j < n && vec1[j] == 0) | |
2267 | j++; | |
2268 | return j; | |
2269 | } | |
2270 | ||
2271 | /* Add a multiple of row R1 of matrix MAT with N columns to row R2: | |
2272 | R2 = R2 + CONST1 * R1. */ | |
2273 | ||
2274 | static void | |
2275 | lambda_matrix_row_add (lambda_matrix mat, int n, int r1, int r2, int const1) | |
2276 | { | |
2277 | int i; | |
2278 | ||
2279 | if (const1 == 0) | |
2280 | return; | |
2281 | ||
2282 | for (i = 0; i < n; i++) | |
2283 | mat[r2][i] += const1 * mat[r1][i]; | |
2284 | } | |
2285 | ||
2286 | /* Swap rows R1 and R2 in matrix MAT. */ | |
2287 | ||
2288 | static void | |
2289 | lambda_matrix_row_exchange (lambda_matrix mat, int r1, int r2) | |
2290 | { | |
2291 | lambda_vector row; | |
2292 | ||
2293 | row = mat[r1]; | |
2294 | mat[r1] = mat[r2]; | |
2295 | mat[r2] = row; | |
2296 | } | |
2297 | ||
2298 | /* Multiply vector VEC1 of length SIZE by a constant CONST1, | |
2299 | and store the result in VEC2. */ | |
2300 | ||
2301 | static void | |
2302 | lambda_vector_mult_const (lambda_vector vec1, lambda_vector vec2, | |
2303 | int size, int const1) | |
2304 | { | |
2305 | int i; | |
2306 | ||
2307 | if (const1 == 0) | |
2308 | lambda_vector_clear (vec2, size); | |
2309 | else | |
2310 | for (i = 0; i < size; i++) | |
2311 | vec2[i] = const1 * vec1[i]; | |
2312 | } | |
2313 | ||
2314 | /* Negate vector VEC1 with length SIZE and store it in VEC2. */ | |
2315 | ||
2316 | static void | |
2317 | lambda_vector_negate (lambda_vector vec1, lambda_vector vec2, | |
2318 | int size) | |
2319 | { | |
2320 | lambda_vector_mult_const (vec1, vec2, size, -1); | |
2321 | } | |
2322 | ||
2323 | /* Negate row R1 of matrix MAT which has N columns. */ | |
2324 | ||
2325 | static void | |
2326 | lambda_matrix_row_negate (lambda_matrix mat, int n, int r1) | |
2327 | { | |
2328 | lambda_vector_negate (mat[r1], mat[r1], n); | |
2329 | } | |
2330 | ||
2331 | /* Return true if two vectors are equal. */ | |
2332 | ||
2333 | static bool | |
2334 | lambda_vector_equal (lambda_vector vec1, lambda_vector vec2, int size) | |
2335 | { | |
2336 | int i; | |
2337 | for (i = 0; i < size; i++) | |
2338 | if (vec1[i] != vec2[i]) | |
2339 | return false; | |
2340 | return true; | |
2341 | } | |
2342 | ||
2343 | /* Given an M x N integer matrix A, this function determines an M x | |
2344 | M unimodular matrix U, and an M x N echelon matrix S such that | |
2345 | "U.A = S". This decomposition is also known as "right Hermite". | |
2346 | ||
2347 | Ref: Algorithm 2.1 page 33 in "Loop Transformations for | |
2348 | Restructuring Compilers" Utpal Banerjee. */ | |
2349 | ||
2350 | static void | |
2351 | lambda_matrix_right_hermite (lambda_matrix A, int m, int n, | |
2352 | lambda_matrix S, lambda_matrix U) | |
2353 | { | |
2354 | int i, j, i0 = 0; | |
2355 | ||
2356 | lambda_matrix_copy (A, S, m, n); | |
2357 | lambda_matrix_id (U, m); | |
2358 | ||
2359 | for (j = 0; j < n; j++) | |
2360 | { | |
2361 | if (lambda_vector_first_nz (S[j], m, i0) < m) | |
2362 | { | |
2363 | ++i0; | |
2364 | for (i = m - 1; i >= i0; i--) | |
2365 | { | |
2366 | while (S[i][j] != 0) | |
2367 | { | |
2368 | int sigma, factor, a, b; | |
2369 | ||
2370 | a = S[i-1][j]; | |
2371 | b = S[i][j]; | |
2372 | sigma = (a * b < 0) ? -1: 1; | |
2373 | a = abs (a); | |
2374 | b = abs (b); | |
2375 | factor = sigma * (a / b); | |
2376 | ||
2377 | lambda_matrix_row_add (S, n, i, i-1, -factor); | |
2378 | lambda_matrix_row_exchange (S, i, i-1); | |
2379 | ||
2380 | lambda_matrix_row_add (U, m, i, i-1, -factor); | |
2381 | lambda_matrix_row_exchange (U, i, i-1); | |
2382 | } | |
2383 | } | |
2384 | } | |
2385 | } | |
2386 | } | |
2387 | ||
56cf8686 | 2388 | /* Determines the overlapping elements due to accesses CHREC_A and |
0ff4040e SP |
2389 | CHREC_B, that are affine functions. This function cannot handle |
2390 | symbolic evolution functions, ie. when initial conditions are | |
2391 | parameters, because it uses lambda matrices of integers. */ | |
56cf8686 SP |
2392 | |
2393 | static void | |
b8698a0f | 2394 | analyze_subscript_affine_affine (tree chrec_a, |
56cf8686 | 2395 | tree chrec_b, |
b8698a0f L |
2396 | conflict_function **overlaps_a, |
2397 | conflict_function **overlaps_b, | |
86df10e3 | 2398 | tree *last_conflicts) |
56cf8686 | 2399 | { |
86df10e3 | 2400 | unsigned nb_vars_a, nb_vars_b, dim; |
fd727b34 | 2401 | HOST_WIDE_INT init_a, init_b, gamma, gcd_alpha_beta; |
86df10e3 | 2402 | lambda_matrix A, U, S; |
f873b205 | 2403 | struct obstack scratch_obstack; |
86df10e3 | 2404 | |
e2157b49 | 2405 | if (eq_evolutions_p (chrec_a, chrec_b)) |
416f403e | 2406 | { |
e2157b49 SP |
2407 | /* The accessed index overlaps for each iteration in the |
2408 | loop. */ | |
d93817c4 ZD |
2409 | *overlaps_a = conflict_fn (1, affine_fn_cst (integer_zero_node)); |
2410 | *overlaps_b = conflict_fn (1, affine_fn_cst (integer_zero_node)); | |
416f403e DB |
2411 | *last_conflicts = chrec_dont_know; |
2412 | return; | |
2413 | } | |
56cf8686 SP |
2414 | if (dump_file && (dump_flags & TDF_DETAILS)) |
2415 | fprintf (dump_file, "(analyze_subscript_affine_affine \n"); | |
b8698a0f | 2416 | |
56cf8686 SP |
2417 | /* For determining the initial intersection, we have to solve a |
2418 | Diophantine equation. This is the most time consuming part. | |
b8698a0f | 2419 | |
56cf8686 SP |
2420 | For answering to the question: "Is there a dependence?" we have |
2421 | to prove that there exists a solution to the Diophantine | |
2422 | equation, and that the solution is in the iteration domain, | |
89dbed81 | 2423 | i.e. the solution is positive or zero, and that the solution |
56cf8686 SP |
2424 | happens before the upper bound loop.nb_iterations. Otherwise |
2425 | there is no dependence. This function outputs a description of | |
2426 | the iterations that hold the intersections. */ | |
2427 | ||
86df10e3 SP |
2428 | nb_vars_a = nb_vars_in_chrec (chrec_a); |
2429 | nb_vars_b = nb_vars_in_chrec (chrec_b); | |
2430 | ||
f873b205 LB |
2431 | gcc_obstack_init (&scratch_obstack); |
2432 | ||
86df10e3 | 2433 | dim = nb_vars_a + nb_vars_b; |
f873b205 LB |
2434 | U = lambda_matrix_new (dim, dim, &scratch_obstack); |
2435 | A = lambda_matrix_new (dim, 1, &scratch_obstack); | |
2436 | S = lambda_matrix_new (dim, 1, &scratch_obstack); | |
86df10e3 | 2437 | |
5b78fc3e JS |
2438 | init_a = int_cst_value (initialize_matrix_A (A, chrec_a, 0, 1)); |
2439 | init_b = int_cst_value (initialize_matrix_A (A, chrec_b, nb_vars_a, -1)); | |
86df10e3 SP |
2440 | gamma = init_b - init_a; |
2441 | ||
2442 | /* Don't do all the hard work of solving the Diophantine equation | |
b8698a0f | 2443 | when we already know the solution: for example, |
86df10e3 SP |
2444 | | {3, +, 1}_1 |
2445 | | {3, +, 4}_2 | |
2446 | | gamma = 3 - 3 = 0. | |
b8698a0f | 2447 | Then the first overlap occurs during the first iterations: |
86df10e3 SP |
2448 | | {3, +, 1}_1 ({0, +, 4}_x) = {3, +, 4}_2 ({0, +, 1}_x) |
2449 | */ | |
2450 | if (gamma == 0) | |
56cf8686 | 2451 | { |
86df10e3 | 2452 | if (nb_vars_a == 1 && nb_vars_b == 1) |
56cf8686 | 2453 | { |
fd727b34 | 2454 | HOST_WIDE_INT step_a, step_b; |
4839cb59 | 2455 | HOST_WIDE_INT niter, niter_a, niter_b; |
d93817c4 | 2456 | affine_fn ova, ovb; |
86df10e3 | 2457 | |
652c4c71 RG |
2458 | niter_a = max_stmt_executions_int (get_chrec_loop (chrec_a)); |
2459 | niter_b = max_stmt_executions_int (get_chrec_loop (chrec_b)); | |
86df10e3 | 2460 | niter = MIN (niter_a, niter_b); |
6b6fa4e9 SP |
2461 | step_a = int_cst_value (CHREC_RIGHT (chrec_a)); |
2462 | step_b = int_cst_value (CHREC_RIGHT (chrec_b)); | |
86df10e3 | 2463 | |
b8698a0f L |
2464 | compute_overlap_steps_for_affine_univar (niter, step_a, step_b, |
2465 | &ova, &ovb, | |
86df10e3 | 2466 | last_conflicts, 1); |
d93817c4 ZD |
2467 | *overlaps_a = conflict_fn (1, ova); |
2468 | *overlaps_b = conflict_fn (1, ovb); | |
56cf8686 | 2469 | } |
86df10e3 SP |
2470 | |
2471 | else if (nb_vars_a == 2 && nb_vars_b == 1) | |
2472 | compute_overlap_steps_for_affine_1_2 | |
2473 | (chrec_a, chrec_b, overlaps_a, overlaps_b, last_conflicts); | |
2474 | ||
2475 | else if (nb_vars_a == 1 && nb_vars_b == 2) | |
2476 | compute_overlap_steps_for_affine_1_2 | |
2477 | (chrec_b, chrec_a, overlaps_b, overlaps_a, last_conflicts); | |
2478 | ||
2479 | else | |
56cf8686 | 2480 | { |
0ff4040e SP |
2481 | if (dump_file && (dump_flags & TDF_DETAILS)) |
2482 | fprintf (dump_file, "affine-affine test failed: too many variables.\n"); | |
d93817c4 ZD |
2483 | *overlaps_a = conflict_fn_not_known (); |
2484 | *overlaps_b = conflict_fn_not_known (); | |
86df10e3 | 2485 | *last_conflicts = chrec_dont_know; |
56cf8686 | 2486 | } |
0ff4040e | 2487 | goto end_analyze_subs_aa; |
86df10e3 SP |
2488 | } |
2489 | ||
2490 | /* U.A = S */ | |
2491 | lambda_matrix_right_hermite (A, dim, 1, S, U); | |
2492 | ||
2493 | if (S[0][0] < 0) | |
2494 | { | |
2495 | S[0][0] *= -1; | |
2496 | lambda_matrix_row_negate (U, dim, 0); | |
2497 | } | |
2498 | gcd_alpha_beta = S[0][0]; | |
2499 | ||
ba42e045 SP |
2500 | /* Something went wrong: for example in {1, +, 0}_5 vs. {0, +, 0}_5, |
2501 | but that is a quite strange case. Instead of ICEing, answer | |
2502 | don't know. */ | |
2503 | if (gcd_alpha_beta == 0) | |
2504 | { | |
d93817c4 ZD |
2505 | *overlaps_a = conflict_fn_not_known (); |
2506 | *overlaps_b = conflict_fn_not_known (); | |
ba42e045 SP |
2507 | *last_conflicts = chrec_dont_know; |
2508 | goto end_analyze_subs_aa; | |
2509 | } | |
2510 | ||
86df10e3 SP |
2511 | /* The classic "gcd-test". */ |
2512 | if (!int_divides_p (gcd_alpha_beta, gamma)) | |
2513 | { | |
2514 | /* The "gcd-test" has determined that there is no integer | |
2515 | solution, i.e. there is no dependence. */ | |
d93817c4 ZD |
2516 | *overlaps_a = conflict_fn_no_dependence (); |
2517 | *overlaps_b = conflict_fn_no_dependence (); | |
86df10e3 SP |
2518 | *last_conflicts = integer_zero_node; |
2519 | } | |
2520 | ||
2521 | /* Both access functions are univariate. This includes SIV and MIV cases. */ | |
2522 | else if (nb_vars_a == 1 && nb_vars_b == 1) | |
2523 | { | |
2524 | /* Both functions should have the same evolution sign. */ | |
2525 | if (((A[0][0] > 0 && -A[1][0] > 0) | |
2526 | || (A[0][0] < 0 && -A[1][0] < 0))) | |
56cf8686 SP |
2527 | { |
2528 | /* The solutions are given by: | |
b8698a0f | 2529 | | |
86df10e3 SP |
2530 | | [GAMMA/GCD_ALPHA_BETA t].[u11 u12] = [x0] |
2531 | | [u21 u22] [y0] | |
b8698a0f | 2532 | |
56cf8686 | 2533 | For a given integer t. Using the following variables, |
b8698a0f | 2534 | |
56cf8686 SP |
2535 | | i0 = u11 * gamma / gcd_alpha_beta |
2536 | | j0 = u12 * gamma / gcd_alpha_beta | |
2537 | | i1 = u21 | |
2538 | | j1 = u22 | |
b8698a0f | 2539 | |
56cf8686 | 2540 | the solutions are: |
b8698a0f L |
2541 | |
2542 | | x0 = i0 + i1 * t, | |
86df10e3 | 2543 | | y0 = j0 + j1 * t. */ |
2c26cbfd | 2544 | HOST_WIDE_INT i0, j0, i1, j1; |
86df10e3 SP |
2545 | |
2546 | i0 = U[0][0] * gamma / gcd_alpha_beta; | |
2547 | j0 = U[0][1] * gamma / gcd_alpha_beta; | |
2548 | i1 = U[1][0]; | |
2549 | j1 = U[1][1]; | |
2550 | ||
2551 | if ((i1 == 0 && i0 < 0) | |
2552 | || (j1 == 0 && j0 < 0)) | |
56cf8686 | 2553 | { |
b8698a0f L |
2554 | /* There is no solution. |
2555 | FIXME: The case "i0 > nb_iterations, j0 > nb_iterations" | |
2556 | falls in here, but for the moment we don't look at the | |
56cf8686 | 2557 | upper bound of the iteration domain. */ |
d93817c4 ZD |
2558 | *overlaps_a = conflict_fn_no_dependence (); |
2559 | *overlaps_b = conflict_fn_no_dependence (); | |
86df10e3 | 2560 | *last_conflicts = integer_zero_node; |
2c26cbfd | 2561 | goto end_analyze_subs_aa; |
86df10e3 SP |
2562 | } |
2563 | ||
2c26cbfd | 2564 | if (i1 > 0 && j1 > 0) |
56cf8686 | 2565 | { |
652c4c71 RG |
2566 | HOST_WIDE_INT niter_a |
2567 | = max_stmt_executions_int (get_chrec_loop (chrec_a)); | |
2568 | HOST_WIDE_INT niter_b | |
2569 | = max_stmt_executions_int (get_chrec_loop (chrec_b)); | |
2c26cbfd SP |
2570 | HOST_WIDE_INT niter = MIN (niter_a, niter_b); |
2571 | ||
2572 | /* (X0, Y0) is a solution of the Diophantine equation: | |
2573 | "chrec_a (X0) = chrec_b (Y0)". */ | |
2574 | HOST_WIDE_INT tau1 = MAX (CEIL (-i0, i1), | |
2575 | CEIL (-j0, j1)); | |
2576 | HOST_WIDE_INT x0 = i1 * tau1 + i0; | |
2577 | HOST_WIDE_INT y0 = j1 * tau1 + j0; | |
2578 | ||
2579 | /* (X1, Y1) is the smallest positive solution of the eq | |
2580 | "chrec_a (X1) = chrec_b (Y1)", i.e. this is where the | |
2581 | first conflict occurs. */ | |
2582 | HOST_WIDE_INT min_multiple = MIN (x0 / i1, y0 / j1); | |
2583 | HOST_WIDE_INT x1 = x0 - i1 * min_multiple; | |
2584 | HOST_WIDE_INT y1 = y0 - j1 * min_multiple; | |
2585 | ||
2586 | if (niter > 0) | |
56cf8686 | 2587 | { |
2c26cbfd SP |
2588 | HOST_WIDE_INT tau2 = MIN (FLOOR_DIV (niter - i0, i1), |
2589 | FLOOR_DIV (niter - j0, j1)); | |
2590 | HOST_WIDE_INT last_conflict = tau2 - (x1 - i0)/i1; | |
86df10e3 | 2591 | |
2c26cbfd SP |
2592 | /* If the overlap occurs outside of the bounds of the |
2593 | loop, there is no dependence. */ | |
9e517d61 | 2594 | if (x1 >= niter || y1 >= niter) |
56cf8686 | 2595 | { |
2c26cbfd SP |
2596 | *overlaps_a = conflict_fn_no_dependence (); |
2597 | *overlaps_b = conflict_fn_no_dependence (); | |
2598 | *last_conflicts = integer_zero_node; | |
2599 | goto end_analyze_subs_aa; | |
56cf8686 SP |
2600 | } |
2601 | else | |
2c26cbfd | 2602 | *last_conflicts = build_int_cst (NULL_TREE, last_conflict); |
56cf8686 | 2603 | } |
56cf8686 | 2604 | else |
2c26cbfd SP |
2605 | *last_conflicts = chrec_dont_know; |
2606 | ||
2607 | *overlaps_a | |
2608 | = conflict_fn (1, | |
2609 | affine_fn_univar (build_int_cst (NULL_TREE, x1), | |
2610 | 1, | |
2611 | build_int_cst (NULL_TREE, i1))); | |
2612 | *overlaps_b | |
2613 | = conflict_fn (1, | |
2614 | affine_fn_univar (build_int_cst (NULL_TREE, y1), | |
2615 | 1, | |
2616 | build_int_cst (NULL_TREE, j1))); | |
2617 | } | |
2618 | else | |
2619 | { | |
2620 | /* FIXME: For the moment, the upper bound of the | |
2621 | iteration domain for i and j is not checked. */ | |
2622 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2623 | fprintf (dump_file, "affine-affine test failed: unimplemented.\n"); | |
2624 | *overlaps_a = conflict_fn_not_known (); | |
2625 | *overlaps_b = conflict_fn_not_known (); | |
2626 | *last_conflicts = chrec_dont_know; | |
56cf8686 SP |
2627 | } |
2628 | } | |
86df10e3 SP |
2629 | else |
2630 | { | |
0ff4040e SP |
2631 | if (dump_file && (dump_flags & TDF_DETAILS)) |
2632 | fprintf (dump_file, "affine-affine test failed: unimplemented.\n"); | |
d93817c4 ZD |
2633 | *overlaps_a = conflict_fn_not_known (); |
2634 | *overlaps_b = conflict_fn_not_known (); | |
86df10e3 SP |
2635 | *last_conflicts = chrec_dont_know; |
2636 | } | |
56cf8686 | 2637 | } |
56cf8686 SP |
2638 | else |
2639 | { | |
0ff4040e SP |
2640 | if (dump_file && (dump_flags & TDF_DETAILS)) |
2641 | fprintf (dump_file, "affine-affine test failed: unimplemented.\n"); | |
d93817c4 ZD |
2642 | *overlaps_a = conflict_fn_not_known (); |
2643 | *overlaps_b = conflict_fn_not_known (); | |
86df10e3 | 2644 | *last_conflicts = chrec_dont_know; |
56cf8686 | 2645 | } |
86df10e3 | 2646 | |
b8698a0f | 2647 | end_analyze_subs_aa: |
f873b205 | 2648 | obstack_free (&scratch_obstack, NULL); |
56cf8686 SP |
2649 | if (dump_file && (dump_flags & TDF_DETAILS)) |
2650 | { | |
2651 | fprintf (dump_file, " (overlaps_a = "); | |
d93817c4 | 2652 | dump_conflict_function (dump_file, *overlaps_a); |
56cf8686 | 2653 | fprintf (dump_file, ")\n (overlaps_b = "); |
d93817c4 | 2654 | dump_conflict_function (dump_file, *overlaps_b); |
56cf8686 | 2655 | fprintf (dump_file, ")\n"); |
0ff4040e | 2656 | fprintf (dump_file, ")\n"); |
56cf8686 | 2657 | } |
0ff4040e SP |
2658 | } |
2659 | ||
2660 | /* Returns true when analyze_subscript_affine_affine can be used for | |
2661 | determining the dependence relation between chrec_a and chrec_b, | |
2662 | that contain symbols. This function modifies chrec_a and chrec_b | |
2663 | such that the analysis result is the same, and such that they don't | |
b8698a0f | 2664 | contain symbols, and then can safely be passed to the analyzer. |
0ff4040e SP |
2665 | |
2666 | Example: The analysis of the following tuples of evolutions produce | |
2667 | the same results: {x+1, +, 1}_1 vs. {x+3, +, 1}_1, and {-2, +, 1}_1 | |
2668 | vs. {0, +, 1}_1 | |
b8698a0f | 2669 | |
0ff4040e SP |
2670 | {x+1, +, 1}_1 ({2, +, 1}_1) = {x+3, +, 1}_1 ({0, +, 1}_1) |
2671 | {-2, +, 1}_1 ({2, +, 1}_1) = {0, +, 1}_1 ({0, +, 1}_1) | |
2672 | */ | |
2673 | ||
2674 | static bool | |
2675 | can_use_analyze_subscript_affine_affine (tree *chrec_a, tree *chrec_b) | |
2676 | { | |
16a2acea | 2677 | tree diff, type, left_a, left_b, right_b; |
0ff4040e SP |
2678 | |
2679 | if (chrec_contains_symbols (CHREC_RIGHT (*chrec_a)) | |
2680 | || chrec_contains_symbols (CHREC_RIGHT (*chrec_b))) | |
2681 | /* FIXME: For the moment not handled. Might be refined later. */ | |
2682 | return false; | |
2683 | ||
16a2acea SP |
2684 | type = chrec_type (*chrec_a); |
2685 | left_a = CHREC_LEFT (*chrec_a); | |
726a989a | 2686 | left_b = chrec_convert (type, CHREC_LEFT (*chrec_b), NULL); |
16a2acea SP |
2687 | diff = chrec_fold_minus (type, left_a, left_b); |
2688 | ||
0ff4040e SP |
2689 | if (!evolution_function_is_constant_p (diff)) |
2690 | return false; | |
2691 | ||
56cf8686 | 2692 | if (dump_file && (dump_flags & TDF_DETAILS)) |
0ff4040e SP |
2693 | fprintf (dump_file, "can_use_subscript_aff_aff_for_symbolic \n"); |
2694 | ||
b8698a0f | 2695 | *chrec_a = build_polynomial_chrec (CHREC_VARIABLE (*chrec_a), |
0ff4040e | 2696 | diff, CHREC_RIGHT (*chrec_a)); |
726a989a | 2697 | right_b = chrec_convert (type, CHREC_RIGHT (*chrec_b), NULL); |
0ff4040e | 2698 | *chrec_b = build_polynomial_chrec (CHREC_VARIABLE (*chrec_b), |
dc61cc6b | 2699 | build_int_cst (type, 0), |
16a2acea | 2700 | right_b); |
0ff4040e | 2701 | return true; |
56cf8686 SP |
2702 | } |
2703 | ||
2704 | /* Analyze a SIV (Single Index Variable) subscript. *OVERLAPS_A and | |
2705 | *OVERLAPS_B are initialized to the functions that describe the | |
2706 | relation between the elements accessed twice by CHREC_A and | |
2707 | CHREC_B. For k >= 0, the following property is verified: | |
2708 | ||
2709 | CHREC_A (*OVERLAPS_A (k)) = CHREC_B (*OVERLAPS_B (k)). */ | |
2710 | ||
2711 | static void | |
b8698a0f | 2712 | analyze_siv_subscript (tree chrec_a, |
56cf8686 | 2713 | tree chrec_b, |
b8698a0f L |
2714 | conflict_function **overlaps_a, |
2715 | conflict_function **overlaps_b, | |
5b78fc3e JS |
2716 | tree *last_conflicts, |
2717 | int loop_nest_num) | |
56cf8686 | 2718 | { |
0ff4040e | 2719 | dependence_stats.num_siv++; |
b8698a0f | 2720 | |
56cf8686 SP |
2721 | if (dump_file && (dump_flags & TDF_DETAILS)) |
2722 | fprintf (dump_file, "(analyze_siv_subscript \n"); | |
b8698a0f | 2723 | |
56cf8686 | 2724 | if (evolution_function_is_constant_p (chrec_a) |
5b78fc3e | 2725 | && evolution_function_is_affine_in_loop (chrec_b, loop_nest_num)) |
b8698a0f | 2726 | analyze_siv_subscript_cst_affine (chrec_a, chrec_b, |
86df10e3 | 2727 | overlaps_a, overlaps_b, last_conflicts); |
b8698a0f | 2728 | |
5b78fc3e | 2729 | else if (evolution_function_is_affine_in_loop (chrec_a, loop_nest_num) |
56cf8686 | 2730 | && evolution_function_is_constant_p (chrec_b)) |
b8698a0f | 2731 | analyze_siv_subscript_cst_affine (chrec_b, chrec_a, |
86df10e3 | 2732 | overlaps_b, overlaps_a, last_conflicts); |
b8698a0f | 2733 | |
5b78fc3e JS |
2734 | else if (evolution_function_is_affine_in_loop (chrec_a, loop_nest_num) |
2735 | && evolution_function_is_affine_in_loop (chrec_b, loop_nest_num)) | |
0ff4040e SP |
2736 | { |
2737 | if (!chrec_contains_symbols (chrec_a) | |
2738 | && !chrec_contains_symbols (chrec_b)) | |
2739 | { | |
b8698a0f L |
2740 | analyze_subscript_affine_affine (chrec_a, chrec_b, |
2741 | overlaps_a, overlaps_b, | |
0ff4040e SP |
2742 | last_conflicts); |
2743 | ||
d93817c4 ZD |
2744 | if (CF_NOT_KNOWN_P (*overlaps_a) |
2745 | || CF_NOT_KNOWN_P (*overlaps_b)) | |
0ff4040e | 2746 | dependence_stats.num_siv_unimplemented++; |
d93817c4 ZD |
2747 | else if (CF_NO_DEPENDENCE_P (*overlaps_a) |
2748 | || CF_NO_DEPENDENCE_P (*overlaps_b)) | |
0ff4040e SP |
2749 | dependence_stats.num_siv_independent++; |
2750 | else | |
2751 | dependence_stats.num_siv_dependent++; | |
2752 | } | |
b8698a0f | 2753 | else if (can_use_analyze_subscript_affine_affine (&chrec_a, |
0ff4040e SP |
2754 | &chrec_b)) |
2755 | { | |
b8698a0f L |
2756 | analyze_subscript_affine_affine (chrec_a, chrec_b, |
2757 | overlaps_a, overlaps_b, | |
0ff4040e | 2758 | last_conflicts); |
0ff4040e | 2759 | |
d93817c4 ZD |
2760 | if (CF_NOT_KNOWN_P (*overlaps_a) |
2761 | || CF_NOT_KNOWN_P (*overlaps_b)) | |
0ff4040e | 2762 | dependence_stats.num_siv_unimplemented++; |
d93817c4 ZD |
2763 | else if (CF_NO_DEPENDENCE_P (*overlaps_a) |
2764 | || CF_NO_DEPENDENCE_P (*overlaps_b)) | |
0ff4040e SP |
2765 | dependence_stats.num_siv_independent++; |
2766 | else | |
2767 | dependence_stats.num_siv_dependent++; | |
2768 | } | |
2769 | else | |
2770 | goto siv_subscript_dontknow; | |
2771 | } | |
2772 | ||
56cf8686 SP |
2773 | else |
2774 | { | |
0ff4040e SP |
2775 | siv_subscript_dontknow:; |
2776 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2777 | fprintf (dump_file, "siv test failed: unimplemented.\n"); | |
d93817c4 ZD |
2778 | *overlaps_a = conflict_fn_not_known (); |
2779 | *overlaps_b = conflict_fn_not_known (); | |
86df10e3 | 2780 | *last_conflicts = chrec_dont_know; |
0ff4040e | 2781 | dependence_stats.num_siv_unimplemented++; |
56cf8686 | 2782 | } |
b8698a0f | 2783 | |
56cf8686 SP |
2784 | if (dump_file && (dump_flags & TDF_DETAILS)) |
2785 | fprintf (dump_file, ")\n"); | |
2786 | } | |
2787 | ||
55a700ac ZD |
2788 | /* Returns false if we can prove that the greatest common divisor of the steps |
2789 | of CHREC does not divide CST, false otherwise. */ | |
56cf8686 SP |
2790 | |
2791 | static bool | |
ed7a4b4b | 2792 | gcd_of_steps_may_divide_p (const_tree chrec, const_tree cst) |
56cf8686 | 2793 | { |
55a700ac ZD |
2794 | HOST_WIDE_INT cd = 0, val; |
2795 | tree step; | |
0ff4040e | 2796 | |
55a700ac ZD |
2797 | if (!host_integerp (cst, 0)) |
2798 | return true; | |
2799 | val = tree_low_cst (cst, 0); | |
2800 | ||
2801 | while (TREE_CODE (chrec) == POLYNOMIAL_CHREC) | |
2802 | { | |
2803 | step = CHREC_RIGHT (chrec); | |
2804 | if (!host_integerp (step, 0)) | |
2805 | return true; | |
2806 | cd = gcd (cd, tree_low_cst (step, 0)); | |
2807 | chrec = CHREC_LEFT (chrec); | |
56cf8686 | 2808 | } |
55a700ac ZD |
2809 | |
2810 | return val % cd == 0; | |
56cf8686 SP |
2811 | } |
2812 | ||
da9a21f4 SP |
2813 | /* Analyze a MIV (Multiple Index Variable) subscript with respect to |
2814 | LOOP_NEST. *OVERLAPS_A and *OVERLAPS_B are initialized to the | |
2815 | functions that describe the relation between the elements accessed | |
2816 | twice by CHREC_A and CHREC_B. For k >= 0, the following property | |
2817 | is verified: | |
56cf8686 SP |
2818 | |
2819 | CHREC_A (*OVERLAPS_A (k)) = CHREC_B (*OVERLAPS_B (k)). */ | |
2820 | ||
2821 | static void | |
b8698a0f L |
2822 | analyze_miv_subscript (tree chrec_a, |
2823 | tree chrec_b, | |
2824 | conflict_function **overlaps_a, | |
2825 | conflict_function **overlaps_b, | |
da9a21f4 SP |
2826 | tree *last_conflicts, |
2827 | struct loop *loop_nest) | |
56cf8686 | 2828 | { |
33b30201 SP |
2829 | tree type, difference; |
2830 | ||
0ff4040e | 2831 | dependence_stats.num_miv++; |
56cf8686 SP |
2832 | if (dump_file && (dump_flags & TDF_DETAILS)) |
2833 | fprintf (dump_file, "(analyze_miv_subscript \n"); | |
e2157b49 | 2834 | |
33b30201 | 2835 | type = signed_type_for_types (TREE_TYPE (chrec_a), TREE_TYPE (chrec_b)); |
726a989a RB |
2836 | chrec_a = chrec_convert (type, chrec_a, NULL); |
2837 | chrec_b = chrec_convert (type, chrec_b, NULL); | |
33b30201 | 2838 | difference = chrec_fold_minus (type, chrec_a, chrec_b); |
b8698a0f | 2839 | |
e2157b49 | 2840 | if (eq_evolutions_p (chrec_a, chrec_b)) |
56cf8686 SP |
2841 | { |
2842 | /* Access functions are the same: all the elements are accessed | |
2843 | in the same order. */ | |
d93817c4 ZD |
2844 | *overlaps_a = conflict_fn (1, affine_fn_cst (integer_zero_node)); |
2845 | *overlaps_b = conflict_fn (1, affine_fn_cst (integer_zero_node)); | |
b4a9343c | 2846 | *last_conflicts = max_stmt_executions_tree (get_chrec_loop (chrec_a)); |
0ff4040e | 2847 | dependence_stats.num_miv_dependent++; |
56cf8686 | 2848 | } |
b8698a0f | 2849 | |
56cf8686 SP |
2850 | else if (evolution_function_is_constant_p (difference) |
2851 | /* For the moment, the following is verified: | |
da9a21f4 SP |
2852 | evolution_function_is_affine_multivariate_p (chrec_a, |
2853 | loop_nest->num) */ | |
55a700ac | 2854 | && !gcd_of_steps_may_divide_p (chrec_a, difference)) |
56cf8686 SP |
2855 | { |
2856 | /* testsuite/.../ssa-chrec-33.c | |
b8698a0f L |
2857 | {{21, +, 2}_1, +, -2}_2 vs. {{20, +, 2}_1, +, -2}_2 |
2858 | ||
55a700ac ZD |
2859 | The difference is 1, and all the evolution steps are multiples |
2860 | of 2, consequently there are no overlapping elements. */ | |
d93817c4 ZD |
2861 | *overlaps_a = conflict_fn_no_dependence (); |
2862 | *overlaps_b = conflict_fn_no_dependence (); | |
86df10e3 | 2863 | *last_conflicts = integer_zero_node; |
0ff4040e | 2864 | dependence_stats.num_miv_independent++; |
56cf8686 | 2865 | } |
b8698a0f | 2866 | |
da9a21f4 | 2867 | else if (evolution_function_is_affine_multivariate_p (chrec_a, loop_nest->num) |
0ff4040e | 2868 | && !chrec_contains_symbols (chrec_a) |
da9a21f4 | 2869 | && evolution_function_is_affine_multivariate_p (chrec_b, loop_nest->num) |
0ff4040e | 2870 | && !chrec_contains_symbols (chrec_b)) |
56cf8686 SP |
2871 | { |
2872 | /* testsuite/.../ssa-chrec-35.c | |
2873 | {0, +, 1}_2 vs. {0, +, 1}_3 | |
2874 | the overlapping elements are respectively located at iterations: | |
b8698a0f L |
2875 | {0, +, 1}_x and {0, +, 1}_x, |
2876 | in other words, we have the equality: | |
86df10e3 | 2877 | {0, +, 1}_2 ({0, +, 1}_x) = {0, +, 1}_3 ({0, +, 1}_x) |
b8698a0f L |
2878 | |
2879 | Other examples: | |
2880 | {{0, +, 1}_1, +, 2}_2 ({0, +, 1}_x, {0, +, 1}_y) = | |
86df10e3 SP |
2881 | {0, +, 1}_1 ({{0, +, 1}_x, +, 2}_y) |
2882 | ||
b8698a0f | 2883 | {{0, +, 2}_1, +, 3}_2 ({0, +, 1}_y, {0, +, 1}_x) = |
86df10e3 | 2884 | {{0, +, 3}_1, +, 2}_2 ({0, +, 1}_x, {0, +, 1}_y) |
56cf8686 | 2885 | */ |
b8698a0f | 2886 | analyze_subscript_affine_affine (chrec_a, chrec_b, |
86df10e3 | 2887 | overlaps_a, overlaps_b, last_conflicts); |
0ff4040e | 2888 | |
d93817c4 ZD |
2889 | if (CF_NOT_KNOWN_P (*overlaps_a) |
2890 | || CF_NOT_KNOWN_P (*overlaps_b)) | |
0ff4040e | 2891 | dependence_stats.num_miv_unimplemented++; |
d93817c4 ZD |
2892 | else if (CF_NO_DEPENDENCE_P (*overlaps_a) |
2893 | || CF_NO_DEPENDENCE_P (*overlaps_b)) | |
0ff4040e SP |
2894 | dependence_stats.num_miv_independent++; |
2895 | else | |
2896 | dependence_stats.num_miv_dependent++; | |
56cf8686 | 2897 | } |
b8698a0f | 2898 | |
56cf8686 SP |
2899 | else |
2900 | { | |
2901 | /* When the analysis is too difficult, answer "don't know". */ | |
0ff4040e SP |
2902 | if (dump_file && (dump_flags & TDF_DETAILS)) |
2903 | fprintf (dump_file, "analyze_miv_subscript test failed: unimplemented.\n"); | |
2904 | ||
d93817c4 ZD |
2905 | *overlaps_a = conflict_fn_not_known (); |
2906 | *overlaps_b = conflict_fn_not_known (); | |
86df10e3 | 2907 | *last_conflicts = chrec_dont_know; |
0ff4040e | 2908 | dependence_stats.num_miv_unimplemented++; |
56cf8686 | 2909 | } |
b8698a0f | 2910 | |
56cf8686 SP |
2911 | if (dump_file && (dump_flags & TDF_DETAILS)) |
2912 | fprintf (dump_file, ")\n"); | |
2913 | } | |
2914 | ||
da9a21f4 SP |
2915 | /* Determines the iterations for which CHREC_A is equal to CHREC_B in |
2916 | with respect to LOOP_NEST. OVERLAP_ITERATIONS_A and | |
2917 | OVERLAP_ITERATIONS_B are initialized with two functions that | |
2918 | describe the iterations that contain conflicting elements. | |
b8698a0f | 2919 | |
56cf8686 | 2920 | Remark: For an integer k >= 0, the following equality is true: |
b8698a0f | 2921 | |
56cf8686 SP |
2922 | CHREC_A (OVERLAP_ITERATIONS_A (k)) == CHREC_B (OVERLAP_ITERATIONS_B (k)). |
2923 | */ | |
2924 | ||
b8698a0f L |
2925 | static void |
2926 | analyze_overlapping_iterations (tree chrec_a, | |
2927 | tree chrec_b, | |
2928 | conflict_function **overlap_iterations_a, | |
2929 | conflict_function **overlap_iterations_b, | |
da9a21f4 | 2930 | tree *last_conflicts, struct loop *loop_nest) |
56cf8686 | 2931 | { |
da9a21f4 SP |
2932 | unsigned int lnn = loop_nest->num; |
2933 | ||
0ff4040e | 2934 | dependence_stats.num_subscript_tests++; |
b8698a0f | 2935 | |
56cf8686 SP |
2936 | if (dump_file && (dump_flags & TDF_DETAILS)) |
2937 | { | |
2938 | fprintf (dump_file, "(analyze_overlapping_iterations \n"); | |
2939 | fprintf (dump_file, " (chrec_a = "); | |
2940 | print_generic_expr (dump_file, chrec_a, 0); | |
0ff4040e | 2941 | fprintf (dump_file, ")\n (chrec_b = "); |
56cf8686 SP |
2942 | print_generic_expr (dump_file, chrec_b, 0); |
2943 | fprintf (dump_file, ")\n"); | |
2944 | } | |
0ff4040e | 2945 | |
56cf8686 SP |
2946 | if (chrec_a == NULL_TREE |
2947 | || chrec_b == NULL_TREE | |
2948 | || chrec_contains_undetermined (chrec_a) | |
0ff4040e | 2949 | || chrec_contains_undetermined (chrec_b)) |
56cf8686 | 2950 | { |
0ff4040e | 2951 | dependence_stats.num_subscript_undetermined++; |
b8698a0f | 2952 | |
d93817c4 ZD |
2953 | *overlap_iterations_a = conflict_fn_not_known (); |
2954 | *overlap_iterations_b = conflict_fn_not_known (); | |
56cf8686 | 2955 | } |
0ff4040e | 2956 | |
b8698a0f | 2957 | /* If they are the same chrec, and are affine, they overlap |
0ff4040e SP |
2958 | on every iteration. */ |
2959 | else if (eq_evolutions_p (chrec_a, chrec_b) | |
3e6f8b56 SP |
2960 | && (evolution_function_is_affine_multivariate_p (chrec_a, lnn) |
2961 | || operand_equal_p (chrec_a, chrec_b, 0))) | |
0ff4040e SP |
2962 | { |
2963 | dependence_stats.num_same_subscript_function++; | |
d93817c4 ZD |
2964 | *overlap_iterations_a = conflict_fn (1, affine_fn_cst (integer_zero_node)); |
2965 | *overlap_iterations_b = conflict_fn (1, affine_fn_cst (integer_zero_node)); | |
0ff4040e SP |
2966 | *last_conflicts = chrec_dont_know; |
2967 | } | |
2968 | ||
2969 | /* If they aren't the same, and aren't affine, we can't do anything | |
3e6f8b56 | 2970 | yet. */ |
b8698a0f | 2971 | else if ((chrec_contains_symbols (chrec_a) |
0ff4040e | 2972 | || chrec_contains_symbols (chrec_b)) |
da9a21f4 SP |
2973 | && (!evolution_function_is_affine_multivariate_p (chrec_a, lnn) |
2974 | || !evolution_function_is_affine_multivariate_p (chrec_b, lnn))) | |
0ff4040e SP |
2975 | { |
2976 | dependence_stats.num_subscript_undetermined++; | |
d93817c4 ZD |
2977 | *overlap_iterations_a = conflict_fn_not_known (); |
2978 | *overlap_iterations_b = conflict_fn_not_known (); | |
0ff4040e SP |
2979 | } |
2980 | ||
56cf8686 | 2981 | else if (ziv_subscript_p (chrec_a, chrec_b)) |
b8698a0f | 2982 | analyze_ziv_subscript (chrec_a, chrec_b, |
86df10e3 SP |
2983 | overlap_iterations_a, overlap_iterations_b, |
2984 | last_conflicts); | |
b8698a0f | 2985 | |
56cf8686 | 2986 | else if (siv_subscript_p (chrec_a, chrec_b)) |
b8698a0f L |
2987 | analyze_siv_subscript (chrec_a, chrec_b, |
2988 | overlap_iterations_a, overlap_iterations_b, | |
5b78fc3e | 2989 | last_conflicts, lnn); |
b8698a0f | 2990 | |
56cf8686 | 2991 | else |
b8698a0f | 2992 | analyze_miv_subscript (chrec_a, chrec_b, |
86df10e3 | 2993 | overlap_iterations_a, overlap_iterations_b, |
da9a21f4 | 2994 | last_conflicts, loop_nest); |
b8698a0f | 2995 | |
56cf8686 SP |
2996 | if (dump_file && (dump_flags & TDF_DETAILS)) |
2997 | { | |
2998 | fprintf (dump_file, " (overlap_iterations_a = "); | |
d93817c4 | 2999 | dump_conflict_function (dump_file, *overlap_iterations_a); |
56cf8686 | 3000 | fprintf (dump_file, ")\n (overlap_iterations_b = "); |
d93817c4 | 3001 | dump_conflict_function (dump_file, *overlap_iterations_b); |
56cf8686 | 3002 | fprintf (dump_file, ")\n"); |
0ff4040e | 3003 | fprintf (dump_file, ")\n"); |
56cf8686 SP |
3004 | } |
3005 | } | |
3006 | ||
ba42e045 | 3007 | /* Helper function for uniquely inserting distance vectors. */ |
56cf8686 | 3008 | |
ba42e045 SP |
3009 | static void |
3010 | save_dist_v (struct data_dependence_relation *ddr, lambda_vector dist_v) | |
3011 | { | |
3012 | unsigned i; | |
3013 | lambda_vector v; | |
56cf8686 | 3014 | |
ac47786e | 3015 | FOR_EACH_VEC_ELT (lambda_vector, DDR_DIST_VECTS (ddr), i, v) |
ba42e045 SP |
3016 | if (lambda_vector_equal (v, dist_v, DDR_NB_LOOPS (ddr))) |
3017 | return; | |
56cf8686 | 3018 | |
ba42e045 SP |
3019 | VEC_safe_push (lambda_vector, heap, DDR_DIST_VECTS (ddr), dist_v); |
3020 | } | |
56cf8686 | 3021 | |
ba42e045 SP |
3022 | /* Helper function for uniquely inserting direction vectors. */ |
3023 | ||
3024 | static void | |
3025 | save_dir_v (struct data_dependence_relation *ddr, lambda_vector dir_v) | |
56cf8686 SP |
3026 | { |
3027 | unsigned i; | |
ba42e045 | 3028 | lambda_vector v; |
0ff4040e | 3029 | |
ac47786e | 3030 | FOR_EACH_VEC_ELT (lambda_vector, DDR_DIR_VECTS (ddr), i, v) |
ba42e045 SP |
3031 | if (lambda_vector_equal (v, dir_v, DDR_NB_LOOPS (ddr))) |
3032 | return; | |
3033 | ||
3034 | VEC_safe_push (lambda_vector, heap, DDR_DIR_VECTS (ddr), dir_v); | |
3035 | } | |
3036 | ||
3037 | /* Add a distance of 1 on all the loops outer than INDEX. If we | |
3038 | haven't yet determined a distance for this outer loop, push a new | |
3039 | distance vector composed of the previous distance, and a distance | |
3040 | of 1 for this outer loop. Example: | |
3041 | ||
3042 | | loop_1 | |
3043 | | loop_2 | |
3044 | | A[10] | |
3045 | | endloop_2 | |
3046 | | endloop_1 | |
3047 | ||
3048 | Saved vectors are of the form (dist_in_1, dist_in_2). First, we | |
3049 | save (0, 1), then we have to save (1, 0). */ | |
3050 | ||
3051 | static void | |
3052 | add_outer_distances (struct data_dependence_relation *ddr, | |
3053 | lambda_vector dist_v, int index) | |
3054 | { | |
3055 | /* For each outer loop where init_v is not set, the accesses are | |
3056 | in dependence of distance 1 in the loop. */ | |
3057 | while (--index >= 0) | |
3058 | { | |
3059 | lambda_vector save_v = lambda_vector_new (DDR_NB_LOOPS (ddr)); | |
3060 | lambda_vector_copy (dist_v, save_v, DDR_NB_LOOPS (ddr)); | |
3061 | save_v[index] = 1; | |
3062 | save_dist_v (ddr, save_v); | |
3063 | } | |
3064 | } | |
3065 | ||
3066 | /* Return false when fail to represent the data dependence as a | |
3067 | distance vector. INIT_B is set to true when a component has been | |
3068 | added to the distance vector DIST_V. INDEX_CARRY is then set to | |
3069 | the index in DIST_V that carries the dependence. */ | |
3070 | ||
3071 | static bool | |
3072 | build_classic_dist_vector_1 (struct data_dependence_relation *ddr, | |
3073 | struct data_reference *ddr_a, | |
3074 | struct data_reference *ddr_b, | |
3075 | lambda_vector dist_v, bool *init_b, | |
3076 | int *index_carry) | |
3077 | { | |
3078 | unsigned i; | |
3079 | lambda_vector init_v = lambda_vector_new (DDR_NB_LOOPS (ddr)); | |
0ff4040e | 3080 | |
36d59cf7 | 3081 | for (i = 0; i < DDR_NUM_SUBSCRIPTS (ddr); i++) |
56cf8686 | 3082 | { |
86df10e3 | 3083 | tree access_fn_a, access_fn_b; |
36d59cf7 | 3084 | struct subscript *subscript = DDR_SUBSCRIPT (ddr, i); |
56cf8686 SP |
3085 | |
3086 | if (chrec_contains_undetermined (SUB_DISTANCE (subscript))) | |
86df10e3 SP |
3087 | { |
3088 | non_affine_dependence_relation (ddr); | |
ba42e045 | 3089 | return false; |
86df10e3 SP |
3090 | } |
3091 | ||
ba42e045 SP |
3092 | access_fn_a = DR_ACCESS_FN (ddr_a, i); |
3093 | access_fn_b = DR_ACCESS_FN (ddr_b, i); | |
56cf8686 | 3094 | |
b8698a0f | 3095 | if (TREE_CODE (access_fn_a) == POLYNOMIAL_CHREC |
86df10e3 | 3096 | && TREE_CODE (access_fn_b) == POLYNOMIAL_CHREC) |
56cf8686 | 3097 | { |
ba42e045 | 3098 | int dist, index; |
a130584a SP |
3099 | int var_a = CHREC_VARIABLE (access_fn_a); |
3100 | int var_b = CHREC_VARIABLE (access_fn_b); | |
ba42e045 | 3101 | |
a130584a SP |
3102 | if (var_a != var_b |
3103 | || chrec_contains_undetermined (SUB_DISTANCE (subscript))) | |
86df10e3 SP |
3104 | { |
3105 | non_affine_dependence_relation (ddr); | |
ba42e045 | 3106 | return false; |
86df10e3 | 3107 | } |
b8698a0f | 3108 | |
6b6fa4e9 | 3109 | dist = int_cst_value (SUB_DISTANCE (subscript)); |
a130584a SP |
3110 | index = index_in_loop_nest (var_a, DDR_LOOP_NEST (ddr)); |
3111 | *index_carry = MIN (index, *index_carry); | |
56cf8686 | 3112 | |
ba42e045 SP |
3113 | /* This is the subscript coupling test. If we have already |
3114 | recorded a distance for this loop (a distance coming from | |
3115 | another subscript), it should be the same. For example, | |
3116 | in the following code, there is no dependence: | |
3117 | ||
56cf8686 SP |
3118 | | loop i = 0, N, 1 |
3119 | | T[i+1][i] = ... | |
3120 | | ... = T[i][i] | |
3121 | | endloop | |
ba42e045 SP |
3122 | */ |
3123 | if (init_v[index] != 0 && dist_v[index] != dist) | |
56cf8686 | 3124 | { |
36d59cf7 | 3125 | finalize_ddr_dependent (ddr, chrec_known); |
ba42e045 | 3126 | return false; |
56cf8686 SP |
3127 | } |
3128 | ||
ba42e045 SP |
3129 | dist_v[index] = dist; |
3130 | init_v[index] = 1; | |
3131 | *init_b = true; | |
3132 | } | |
a50411de | 3133 | else if (!operand_equal_p (access_fn_a, access_fn_b, 0)) |
ba42e045 SP |
3134 | { |
3135 | /* This can be for example an affine vs. constant dependence | |
3136 | (T[i] vs. T[3]) that is not an affine dependence and is | |
3137 | not representable as a distance vector. */ | |
3138 | non_affine_dependence_relation (ddr); | |
3139 | return false; | |
56cf8686 SP |
3140 | } |
3141 | } | |
304afda6 | 3142 | |
ba42e045 SP |
3143 | return true; |
3144 | } | |
304afda6 | 3145 | |
1baf2906 SP |
3146 | /* Return true when the DDR contains only constant access functions. */ |
3147 | ||
3148 | static bool | |
ed7a4b4b | 3149 | constant_access_functions (const struct data_dependence_relation *ddr) |
1baf2906 SP |
3150 | { |
3151 | unsigned i; | |
3152 | ||
3153 | for (i = 0; i < DDR_NUM_SUBSCRIPTS (ddr); i++) | |
3154 | if (!evolution_function_is_constant_p (DR_ACCESS_FN (DDR_A (ddr), i)) | |
3155 | || !evolution_function_is_constant_p (DR_ACCESS_FN (DDR_B (ddr), i))) | |
3156 | return false; | |
3157 | ||
3158 | return true; | |
3159 | } | |
3160 | ||
ba42e045 | 3161 | /* Helper function for the case where DDR_A and DDR_B are the same |
097392de SP |
3162 | multivariate access function with a constant step. For an example |
3163 | see pr34635-1.c. */ | |
86df10e3 | 3164 | |
ba42e045 SP |
3165 | static void |
3166 | add_multivariate_self_dist (struct data_dependence_relation *ddr, tree c_2) | |
3167 | { | |
3168 | int x_1, x_2; | |
3169 | tree c_1 = CHREC_LEFT (c_2); | |
3170 | tree c_0 = CHREC_LEFT (c_1); | |
3171 | lambda_vector dist_v; | |
0ca2faee | 3172 | int v1, v2, cd; |
86df10e3 | 3173 | |
b1e75954 SP |
3174 | /* Polynomials with more than 2 variables are not handled yet. When |
3175 | the evolution steps are parameters, it is not possible to | |
3176 | represent the dependence using classical distance vectors. */ | |
3177 | if (TREE_CODE (c_0) != INTEGER_CST | |
3178 | || TREE_CODE (CHREC_RIGHT (c_1)) != INTEGER_CST | |
3179 | || TREE_CODE (CHREC_RIGHT (c_2)) != INTEGER_CST) | |
3180 | { | |
3181 | DDR_AFFINE_P (ddr) = false; | |
ba42e045 SP |
3182 | return; |
3183 | } | |
304afda6 | 3184 | |
ba42e045 SP |
3185 | x_2 = index_in_loop_nest (CHREC_VARIABLE (c_2), DDR_LOOP_NEST (ddr)); |
3186 | x_1 = index_in_loop_nest (CHREC_VARIABLE (c_1), DDR_LOOP_NEST (ddr)); | |
304afda6 | 3187 | |
ba42e045 SP |
3188 | /* For "{{0, +, 2}_1, +, 3}_2" the distance vector is (3, -2). */ |
3189 | dist_v = lambda_vector_new (DDR_NB_LOOPS (ddr)); | |
6b6fa4e9 SP |
3190 | v1 = int_cst_value (CHREC_RIGHT (c_1)); |
3191 | v2 = int_cst_value (CHREC_RIGHT (c_2)); | |
0ca2faee ZD |
3192 | cd = gcd (v1, v2); |
3193 | v1 /= cd; | |
3194 | v2 /= cd; | |
3195 | ||
3196 | if (v2 < 0) | |
3197 | { | |
3198 | v2 = -v2; | |
3199 | v1 = -v1; | |
3200 | } | |
3201 | ||
3202 | dist_v[x_1] = v2; | |
3203 | dist_v[x_2] = -v1; | |
ba42e045 | 3204 | save_dist_v (ddr, dist_v); |
304afda6 | 3205 | |
ba42e045 SP |
3206 | add_outer_distances (ddr, dist_v, x_1); |
3207 | } | |
304afda6 | 3208 | |
ba42e045 SP |
3209 | /* Helper function for the case where DDR_A and DDR_B are the same |
3210 | access functions. */ | |
37b8a73b | 3211 | |
ba42e045 SP |
3212 | static void |
3213 | add_other_self_distances (struct data_dependence_relation *ddr) | |
3214 | { | |
3215 | lambda_vector dist_v; | |
3216 | unsigned i; | |
3217 | int index_carry = DDR_NB_LOOPS (ddr); | |
304afda6 | 3218 | |
ba42e045 | 3219 | for (i = 0; i < DDR_NUM_SUBSCRIPTS (ddr); i++) |
37b8a73b | 3220 | { |
ba42e045 | 3221 | tree access_fun = DR_ACCESS_FN (DDR_A (ddr), i); |
304afda6 | 3222 | |
ba42e045 | 3223 | if (TREE_CODE (access_fun) == POLYNOMIAL_CHREC) |
304afda6 | 3224 | { |
ba42e045 SP |
3225 | if (!evolution_function_is_univariate_p (access_fun)) |
3226 | { | |
3227 | if (DDR_NUM_SUBSCRIPTS (ddr) != 1) | |
3228 | { | |
3229 | DDR_ARE_DEPENDENT (ddr) = chrec_dont_know; | |
3230 | return; | |
3231 | } | |
3232 | ||
097392de SP |
3233 | access_fun = DR_ACCESS_FN (DDR_A (ddr), 0); |
3234 | ||
3235 | if (TREE_CODE (CHREC_LEFT (access_fun)) == POLYNOMIAL_CHREC) | |
3236 | add_multivariate_self_dist (ddr, access_fun); | |
3237 | else | |
3238 | /* The evolution step is not constant: it varies in | |
3239 | the outer loop, so this cannot be represented by a | |
3240 | distance vector. For example in pr34635.c the | |
3241 | evolution is {0, +, {0, +, 4}_1}_2. */ | |
3242 | DDR_AFFINE_P (ddr) = false; | |
3243 | ||
ba42e045 SP |
3244 | return; |
3245 | } | |
3246 | ||
3247 | index_carry = MIN (index_carry, | |
3248 | index_in_loop_nest (CHREC_VARIABLE (access_fun), | |
3249 | DDR_LOOP_NEST (ddr))); | |
304afda6 | 3250 | } |
37b8a73b SP |
3251 | } |
3252 | ||
ba42e045 SP |
3253 | dist_v = lambda_vector_new (DDR_NB_LOOPS (ddr)); |
3254 | add_outer_distances (ddr, dist_v, index_carry); | |
56cf8686 SP |
3255 | } |
3256 | ||
1baf2906 SP |
3257 | static void |
3258 | insert_innermost_unit_dist_vector (struct data_dependence_relation *ddr) | |
3259 | { | |
3260 | lambda_vector dist_v = lambda_vector_new (DDR_NB_LOOPS (ddr)); | |
3261 | ||
3262 | dist_v[DDR_INNER_LOOP (ddr)] = 1; | |
3263 | save_dist_v (ddr, dist_v); | |
3264 | } | |
3265 | ||
3266 | /* Adds a unit distance vector to DDR when there is a 0 overlap. This | |
3267 | is the case for example when access functions are the same and | |
3268 | equal to a constant, as in: | |
3269 | ||
3270 | | loop_1 | |
3271 | | A[3] = ... | |
3272 | | ... = A[3] | |
3273 | | endloop_1 | |
3274 | ||
3275 | in which case the distance vectors are (0) and (1). */ | |
3276 | ||
3277 | static void | |
3278 | add_distance_for_zero_overlaps (struct data_dependence_relation *ddr) | |
3279 | { | |
3280 | unsigned i, j; | |
3281 | ||
3282 | for (i = 0; i < DDR_NUM_SUBSCRIPTS (ddr); i++) | |
3283 | { | |
3284 | subscript_p sub = DDR_SUBSCRIPT (ddr, i); | |
3285 | conflict_function *ca = SUB_CONFLICTS_IN_A (sub); | |
3286 | conflict_function *cb = SUB_CONFLICTS_IN_B (sub); | |
3287 | ||
3288 | for (j = 0; j < ca->n; j++) | |
3289 | if (affine_function_zero_p (ca->fns[j])) | |
3290 | { | |
3291 | insert_innermost_unit_dist_vector (ddr); | |
3292 | return; | |
3293 | } | |
3294 | ||
3295 | for (j = 0; j < cb->n; j++) | |
3296 | if (affine_function_zero_p (cb->fns[j])) | |
3297 | { | |
3298 | insert_innermost_unit_dist_vector (ddr); | |
3299 | return; | |
3300 | } | |
3301 | } | |
3302 | } | |
3303 | ||
ba42e045 SP |
3304 | /* Compute the classic per loop distance vector. DDR is the data |
3305 | dependence relation to build a vector from. Return false when fail | |
3306 | to represent the data dependence as a distance vector. */ | |
56cf8686 | 3307 | |
464f49d8 | 3308 | static bool |
da9a21f4 SP |
3309 | build_classic_dist_vector (struct data_dependence_relation *ddr, |
3310 | struct loop *loop_nest) | |
56cf8686 | 3311 | { |
304afda6 | 3312 | bool init_b = false; |
ba42e045 SP |
3313 | int index_carry = DDR_NB_LOOPS (ddr); |
3314 | lambda_vector dist_v; | |
304afda6 | 3315 | |
36d59cf7 | 3316 | if (DDR_ARE_DEPENDENT (ddr) != NULL_TREE) |
2f470326 | 3317 | return false; |
ba42e045 SP |
3318 | |
3319 | if (same_access_functions (ddr)) | |
56cf8686 | 3320 | { |
ba42e045 SP |
3321 | /* Save the 0 vector. */ |
3322 | dist_v = lambda_vector_new (DDR_NB_LOOPS (ddr)); | |
3323 | save_dist_v (ddr, dist_v); | |
56cf8686 | 3324 | |
1baf2906 SP |
3325 | if (constant_access_functions (ddr)) |
3326 | add_distance_for_zero_overlaps (ddr); | |
3327 | ||
ba42e045 SP |
3328 | if (DDR_NB_LOOPS (ddr) > 1) |
3329 | add_other_self_distances (ddr); | |
86df10e3 | 3330 | |
ba42e045 SP |
3331 | return true; |
3332 | } | |
86df10e3 | 3333 | |
ba42e045 SP |
3334 | dist_v = lambda_vector_new (DDR_NB_LOOPS (ddr)); |
3335 | if (!build_classic_dist_vector_1 (ddr, DDR_A (ddr), DDR_B (ddr), | |
3336 | dist_v, &init_b, &index_carry)) | |
3337 | return false; | |
86df10e3 | 3338 | |
ba42e045 SP |
3339 | /* Save the distance vector if we initialized one. */ |
3340 | if (init_b) | |
3341 | { | |
3342 | /* Verify a basic constraint: classic distance vectors should | |
3343 | always be lexicographically positive. | |
3344 | ||
3345 | Data references are collected in the order of execution of | |
3346 | the program, thus for the following loop | |
3347 | ||
3348 | | for (i = 1; i < 100; i++) | |
3349 | | for (j = 1; j < 100; j++) | |
3350 | | { | |
3351 | | t = T[j+1][i-1]; // A | |
3352 | | T[j][i] = t + 2; // B | |
3353 | | } | |
3354 | ||
3355 | references are collected following the direction of the wind: | |
3356 | A then B. The data dependence tests are performed also | |
3357 | following this order, such that we're looking at the distance | |
3358 | separating the elements accessed by A from the elements later | |
3359 | accessed by B. But in this example, the distance returned by | |
3360 | test_dep (A, B) is lexicographically negative (-1, 1), that | |
3361 | means that the access A occurs later than B with respect to | |
3362 | the outer loop, ie. we're actually looking upwind. In this | |
3363 | case we solve test_dep (B, A) looking downwind to the | |
3364 | lexicographically positive solution, that returns the | |
3365 | distance vector (1, -1). */ | |
3366 | if (!lambda_vector_lexico_pos (dist_v, DDR_NB_LOOPS (ddr))) | |
3367 | { | |
3368 | lambda_vector save_v = lambda_vector_new (DDR_NB_LOOPS (ddr)); | |
2f470326 JJ |
3369 | if (!subscript_dependence_tester_1 (ddr, DDR_B (ddr), DDR_A (ddr), |
3370 | loop_nest)) | |
3371 | return false; | |
ba42e045 | 3372 | compute_subscript_distance (ddr); |
2f470326 JJ |
3373 | if (!build_classic_dist_vector_1 (ddr, DDR_B (ddr), DDR_A (ddr), |
3374 | save_v, &init_b, &index_carry)) | |
3375 | return false; | |
ba42e045 | 3376 | save_dist_v (ddr, save_v); |
71d5b5e1 | 3377 | DDR_REVERSED_P (ddr) = true; |
ba42e045 SP |
3378 | |
3379 | /* In this case there is a dependence forward for all the | |
3380 | outer loops: | |
3381 | ||
3382 | | for (k = 1; k < 100; k++) | |
3383 | | for (i = 1; i < 100; i++) | |
3384 | | for (j = 1; j < 100; j++) | |
3385 | | { | |
3386 | | t = T[j+1][i-1]; // A | |
3387 | | T[j][i] = t + 2; // B | |
3388 | | } | |
3389 | ||
b8698a0f | 3390 | the vectors are: |
ba42e045 SP |
3391 | (0, 1, -1) |
3392 | (1, 1, -1) | |
3393 | (1, -1, 1) | |
3394 | */ | |
3395 | if (DDR_NB_LOOPS (ddr) > 1) | |
3396 | { | |
3397 | add_outer_distances (ddr, save_v, index_carry); | |
3398 | add_outer_distances (ddr, dist_v, index_carry); | |
86df10e3 | 3399 | } |
ba42e045 SP |
3400 | } |
3401 | else | |
3402 | { | |
3403 | lambda_vector save_v = lambda_vector_new (DDR_NB_LOOPS (ddr)); | |
3404 | lambda_vector_copy (dist_v, save_v, DDR_NB_LOOPS (ddr)); | |
86df10e3 | 3405 | |
ba42e045 | 3406 | if (DDR_NB_LOOPS (ddr) > 1) |
56cf8686 | 3407 | { |
ba42e045 | 3408 | lambda_vector opposite_v = lambda_vector_new (DDR_NB_LOOPS (ddr)); |
86df10e3 | 3409 | |
2f470326 JJ |
3410 | if (!subscript_dependence_tester_1 (ddr, DDR_B (ddr), |
3411 | DDR_A (ddr), loop_nest)) | |
3412 | return false; | |
ba42e045 | 3413 | compute_subscript_distance (ddr); |
2f470326 JJ |
3414 | if (!build_classic_dist_vector_1 (ddr, DDR_B (ddr), DDR_A (ddr), |
3415 | opposite_v, &init_b, | |
3416 | &index_carry)) | |
3417 | return false; | |
86df10e3 | 3418 | |
2f470326 | 3419 | save_dist_v (ddr, save_v); |
ba42e045 SP |
3420 | add_outer_distances (ddr, dist_v, index_carry); |
3421 | add_outer_distances (ddr, opposite_v, index_carry); | |
56cf8686 | 3422 | } |
2f470326 JJ |
3423 | else |
3424 | save_dist_v (ddr, save_v); | |
56cf8686 SP |
3425 | } |
3426 | } | |
ba42e045 SP |
3427 | else |
3428 | { | |
3429 | /* There is a distance of 1 on all the outer loops: Example: | |
3430 | there is a dependence of distance 1 on loop_1 for the array A. | |
304afda6 | 3431 | |
ba42e045 SP |
3432 | | loop_1 |
3433 | | A[5] = ... | |
3434 | | endloop | |
3435 | */ | |
3436 | add_outer_distances (ddr, dist_v, | |
3437 | lambda_vector_first_nz (dist_v, | |
3438 | DDR_NB_LOOPS (ddr), 0)); | |
3439 | } | |
3440 | ||
3441 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
304afda6 | 3442 | { |
ba42e045 | 3443 | unsigned i; |
304afda6 | 3444 | |
ba42e045 SP |
3445 | fprintf (dump_file, "(build_classic_dist_vector\n"); |
3446 | for (i = 0; i < DDR_NUM_DIST_VECTS (ddr); i++) | |
3447 | { | |
3448 | fprintf (dump_file, " dist_vector = ("); | |
3449 | print_lambda_vector (dump_file, DDR_DIST_VECT (ddr, i), | |
3450 | DDR_NB_LOOPS (ddr)); | |
3451 | fprintf (dump_file, " )\n"); | |
3452 | } | |
3453 | fprintf (dump_file, ")\n"); | |
304afda6 SP |
3454 | } |
3455 | ||
ba42e045 SP |
3456 | return true; |
3457 | } | |
56cf8686 | 3458 | |
ba42e045 SP |
3459 | /* Return the direction for a given distance. |
3460 | FIXME: Computing dir this way is suboptimal, since dir can catch | |
3461 | cases that dist is unable to represent. */ | |
86df10e3 | 3462 | |
ba42e045 SP |
3463 | static inline enum data_dependence_direction |
3464 | dir_from_dist (int dist) | |
3465 | { | |
3466 | if (dist > 0) | |
3467 | return dir_positive; | |
3468 | else if (dist < 0) | |
3469 | return dir_negative; | |
3470 | else | |
3471 | return dir_equal; | |
3472 | } | |
304afda6 | 3473 | |
ba42e045 SP |
3474 | /* Compute the classic per loop direction vector. DDR is the data |
3475 | dependence relation to build a vector from. */ | |
304afda6 | 3476 | |
ba42e045 SP |
3477 | static void |
3478 | build_classic_dir_vector (struct data_dependence_relation *ddr) | |
3479 | { | |
3480 | unsigned i, j; | |
3481 | lambda_vector dist_v; | |
86df10e3 | 3482 | |
ac47786e | 3483 | FOR_EACH_VEC_ELT (lambda_vector, DDR_DIST_VECTS (ddr), i, dist_v) |
ba42e045 SP |
3484 | { |
3485 | lambda_vector dir_v = lambda_vector_new (DDR_NB_LOOPS (ddr)); | |
86df10e3 | 3486 | |
ba42e045 SP |
3487 | for (j = 0; j < DDR_NB_LOOPS (ddr); j++) |
3488 | dir_v[j] = dir_from_dist (dist_v[j]); | |
304afda6 | 3489 | |
ba42e045 SP |
3490 | save_dir_v (ddr, dir_v); |
3491 | } | |
56cf8686 SP |
3492 | } |
3493 | ||
ba42e045 SP |
3494 | /* Helper function. Returns true when there is a dependence between |
3495 | data references DRA and DRB. */ | |
0ff4040e | 3496 | |
ba42e045 SP |
3497 | static bool |
3498 | subscript_dependence_tester_1 (struct data_dependence_relation *ddr, | |
3499 | struct data_reference *dra, | |
da9a21f4 SP |
3500 | struct data_reference *drb, |
3501 | struct loop *loop_nest) | |
0ff4040e SP |
3502 | { |
3503 | unsigned int i; | |
0ff4040e | 3504 | tree last_conflicts; |
ebf78a47 | 3505 | struct subscript *subscript; |
9b00587c | 3506 | tree res = NULL_TREE; |
ba42e045 | 3507 | |
ebf78a47 SP |
3508 | for (i = 0; VEC_iterate (subscript_p, DDR_SUBSCRIPTS (ddr), i, subscript); |
3509 | i++) | |
0ff4040e | 3510 | { |
d93817c4 | 3511 | conflict_function *overlaps_a, *overlaps_b; |
ebf78a47 | 3512 | |
b8698a0f | 3513 | analyze_overlapping_iterations (DR_ACCESS_FN (dra, i), |
0ff4040e | 3514 | DR_ACCESS_FN (drb, i), |
b8698a0f | 3515 | &overlaps_a, &overlaps_b, |
da9a21f4 | 3516 | &last_conflicts, loop_nest); |
ebf78a47 | 3517 | |
9b00587c RG |
3518 | if (SUB_CONFLICTS_IN_A (subscript)) |
3519 | free_conflict_function (SUB_CONFLICTS_IN_A (subscript)); | |
3520 | if (SUB_CONFLICTS_IN_B (subscript)) | |
3521 | free_conflict_function (SUB_CONFLICTS_IN_B (subscript)); | |
3522 | ||
3523 | SUB_CONFLICTS_IN_A (subscript) = overlaps_a; | |
3524 | SUB_CONFLICTS_IN_B (subscript) = overlaps_b; | |
3525 | SUB_LAST_CONFLICT (subscript) = last_conflicts; | |
3526 | ||
3527 | /* If there is any undetermined conflict function we have to | |
3528 | give a conservative answer in case we cannot prove that | |
3529 | no dependence exists when analyzing another subscript. */ | |
d93817c4 ZD |
3530 | if (CF_NOT_KNOWN_P (overlaps_a) |
3531 | || CF_NOT_KNOWN_P (overlaps_b)) | |
0ff4040e | 3532 | { |
9b00587c RG |
3533 | res = chrec_dont_know; |
3534 | continue; | |
0ff4040e | 3535 | } |
ebf78a47 | 3536 | |
9b00587c | 3537 | /* When there is a subscript with no dependence we can stop. */ |
d93817c4 ZD |
3538 | else if (CF_NO_DEPENDENCE_P (overlaps_a) |
3539 | || CF_NO_DEPENDENCE_P (overlaps_b)) | |
0ff4040e | 3540 | { |
9b00587c RG |
3541 | res = chrec_known; |
3542 | break; | |
0ff4040e SP |
3543 | } |
3544 | } | |
3545 | ||
9b00587c RG |
3546 | if (res == NULL_TREE) |
3547 | return true; | |
3548 | ||
3549 | if (res == chrec_known) | |
3550 | dependence_stats.num_dependence_independent++; | |
3551 | else | |
3552 | dependence_stats.num_dependence_undetermined++; | |
3553 | finalize_ddr_dependent (ddr, res); | |
3554 | return false; | |
ba42e045 SP |
3555 | } |
3556 | ||
da9a21f4 | 3557 | /* Computes the conflicting iterations in LOOP_NEST, and initialize DDR. */ |
ba42e045 SP |
3558 | |
3559 | static void | |
da9a21f4 SP |
3560 | subscript_dependence_tester (struct data_dependence_relation *ddr, |
3561 | struct loop *loop_nest) | |
ba42e045 | 3562 | { |
b8698a0f | 3563 | |
ba42e045 SP |
3564 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3565 | fprintf (dump_file, "(subscript_dependence_tester \n"); | |
b8698a0f | 3566 | |
da9a21f4 | 3567 | if (subscript_dependence_tester_1 (ddr, DDR_A (ddr), DDR_B (ddr), loop_nest)) |
ba42e045 | 3568 | dependence_stats.num_dependence_dependent++; |
0ff4040e | 3569 | |
0ff4040e | 3570 | compute_subscript_distance (ddr); |
da9a21f4 | 3571 | if (build_classic_dist_vector (ddr, loop_nest)) |
ba42e045 | 3572 | build_classic_dir_vector (ddr); |
0ff4040e SP |
3573 | |
3574 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3575 | fprintf (dump_file, ")\n"); | |
3576 | } | |
3577 | ||
56cf8686 | 3578 | /* Returns true when all the access functions of A are affine or |
da9a21f4 | 3579 | constant with respect to LOOP_NEST. */ |
56cf8686 | 3580 | |
b8698a0f | 3581 | static bool |
ed7a4b4b KG |
3582 | access_functions_are_affine_or_constant_p (const struct data_reference *a, |
3583 | const struct loop *loop_nest) | |
56cf8686 SP |
3584 | { |
3585 | unsigned int i; | |
3d8864c0 | 3586 | VEC(tree,heap) *fns = DR_ACCESS_FNS (a); |
9cbb7989 | 3587 | tree t; |
3d8864c0 | 3588 | |
ac47786e | 3589 | FOR_EACH_VEC_ELT (tree, fns, i, t) |
da9a21f4 SP |
3590 | if (!evolution_function_is_invariant_p (t, loop_nest->num) |
3591 | && !evolution_function_is_affine_multivariate_p (t, loop_nest->num)) | |
56cf8686 | 3592 | return false; |
b8698a0f | 3593 | |
56cf8686 SP |
3594 | return true; |
3595 | } | |
3596 | ||
3d8864c0 SP |
3597 | /* Initializes an equation for an OMEGA problem using the information |
3598 | contained in the ACCESS_FUN. Returns true when the operation | |
3599 | succeeded. | |
3600 | ||
3601 | PB is the omega constraint system. | |
3602 | EQ is the number of the equation to be initialized. | |
3603 | OFFSET is used for shifting the variables names in the constraints: | |
3604 | a constrain is composed of 2 * the number of variables surrounding | |
3605 | dependence accesses. OFFSET is set either to 0 for the first n variables, | |
3606 | then it is set to n. | |
3607 | ACCESS_FUN is expected to be an affine chrec. */ | |
3608 | ||
3609 | static bool | |
b8698a0f L |
3610 | init_omega_eq_with_af (omega_pb pb, unsigned eq, |
3611 | unsigned int offset, tree access_fun, | |
3d8864c0 SP |
3612 | struct data_dependence_relation *ddr) |
3613 | { | |
3614 | switch (TREE_CODE (access_fun)) | |
3615 | { | |
3616 | case POLYNOMIAL_CHREC: | |
3617 | { | |
3618 | tree left = CHREC_LEFT (access_fun); | |
3619 | tree right = CHREC_RIGHT (access_fun); | |
3620 | int var = CHREC_VARIABLE (access_fun); | |
3621 | unsigned var_idx; | |
3622 | ||
3623 | if (TREE_CODE (right) != INTEGER_CST) | |
3624 | return false; | |
3625 | ||
3626 | var_idx = index_in_loop_nest (var, DDR_LOOP_NEST (ddr)); | |
6b6fa4e9 | 3627 | pb->eqs[eq].coef[offset + var_idx + 1] = int_cst_value (right); |
3d8864c0 SP |
3628 | |
3629 | /* Compute the innermost loop index. */ | |
3630 | DDR_INNER_LOOP (ddr) = MAX (DDR_INNER_LOOP (ddr), var_idx); | |
3631 | ||
3632 | if (offset == 0) | |
b8698a0f | 3633 | pb->eqs[eq].coef[var_idx + DDR_NB_LOOPS (ddr) + 1] |
6b6fa4e9 | 3634 | += int_cst_value (right); |
3d8864c0 SP |
3635 | |
3636 | switch (TREE_CODE (left)) | |
3637 | { | |
3638 | case POLYNOMIAL_CHREC: | |
3639 | return init_omega_eq_with_af (pb, eq, offset, left, ddr); | |
3640 | ||
3641 | case INTEGER_CST: | |
6b6fa4e9 | 3642 | pb->eqs[eq].coef[0] += int_cst_value (left); |
3d8864c0 SP |
3643 | return true; |
3644 | ||
3645 | default: | |
3646 | return false; | |
3647 | } | |
3648 | } | |
3649 | ||
3650 | case INTEGER_CST: | |
6b6fa4e9 | 3651 | pb->eqs[eq].coef[0] += int_cst_value (access_fun); |
3d8864c0 SP |
3652 | return true; |
3653 | ||
3654 | default: | |
3655 | return false; | |
3656 | } | |
3657 | } | |
3658 | ||
3659 | /* As explained in the comments preceding init_omega_for_ddr, we have | |
3660 | to set up a system for each loop level, setting outer loops | |
3661 | variation to zero, and current loop variation to positive or zero. | |
3662 | Save each lexico positive distance vector. */ | |
3663 | ||
3664 | static void | |
3665 | omega_extract_distance_vectors (omega_pb pb, | |
3666 | struct data_dependence_relation *ddr) | |
3667 | { | |
3668 | int eq, geq; | |
3669 | unsigned i, j; | |
3670 | struct loop *loopi, *loopj; | |
3671 | enum omega_result res; | |
3672 | ||
3673 | /* Set a new problem for each loop in the nest. The basis is the | |
3674 | problem that we have initialized until now. On top of this we | |
3675 | add new constraints. */ | |
b8698a0f | 3676 | for (i = 0; i <= DDR_INNER_LOOP (ddr) |
3d8864c0 SP |
3677 | && VEC_iterate (loop_p, DDR_LOOP_NEST (ddr), i, loopi); i++) |
3678 | { | |
3679 | int dist = 0; | |
3680 | omega_pb copy = omega_alloc_problem (2 * DDR_NB_LOOPS (ddr), | |
3681 | DDR_NB_LOOPS (ddr)); | |
3682 | ||
3683 | omega_copy_problem (copy, pb); | |
3684 | ||
3685 | /* For all the outer loops "loop_j", add "dj = 0". */ | |
3686 | for (j = 0; | |
3687 | j < i && VEC_iterate (loop_p, DDR_LOOP_NEST (ddr), j, loopj); j++) | |
3688 | { | |
3689 | eq = omega_add_zero_eq (copy, omega_black); | |
3690 | copy->eqs[eq].coef[j + 1] = 1; | |
3691 | } | |
3692 | ||
3693 | /* For "loop_i", add "0 <= di". */ | |
3694 | geq = omega_add_zero_geq (copy, omega_black); | |
3695 | copy->geqs[geq].coef[i + 1] = 1; | |
3696 | ||
3697 | /* Reduce the constraint system, and test that the current | |
3698 | problem is feasible. */ | |
3699 | res = omega_simplify_problem (copy); | |
b8698a0f | 3700 | if (res == omega_false |
3d8864c0 SP |
3701 | || res == omega_unknown |
3702 | || copy->num_geqs > (int) DDR_NB_LOOPS (ddr)) | |
3703 | goto next_problem; | |
3704 | ||
3705 | for (eq = 0; eq < copy->num_subs; eq++) | |
3706 | if (copy->subs[eq].key == (int) i + 1) | |
3707 | { | |
3708 | dist = copy->subs[eq].coef[0]; | |
3709 | goto found_dist; | |
3710 | } | |
3711 | ||
3712 | if (dist == 0) | |
3713 | { | |
3714 | /* Reinitialize problem... */ | |
3715 | omega_copy_problem (copy, pb); | |
3716 | for (j = 0; | |
3717 | j < i && VEC_iterate (loop_p, DDR_LOOP_NEST (ddr), j, loopj); j++) | |
3718 | { | |
3719 | eq = omega_add_zero_eq (copy, omega_black); | |
3720 | copy->eqs[eq].coef[j + 1] = 1; | |
3721 | } | |
3722 | ||
3723 | /* ..., but this time "di = 1". */ | |
3724 | eq = omega_add_zero_eq (copy, omega_black); | |
3725 | copy->eqs[eq].coef[i + 1] = 1; | |
3726 | copy->eqs[eq].coef[0] = -1; | |
3727 | ||
3728 | res = omega_simplify_problem (copy); | |
b8698a0f | 3729 | if (res == omega_false |
3d8864c0 SP |
3730 | || res == omega_unknown |
3731 | || copy->num_geqs > (int) DDR_NB_LOOPS (ddr)) | |
3732 | goto next_problem; | |
3733 | ||
3734 | for (eq = 0; eq < copy->num_subs; eq++) | |
3735 | if (copy->subs[eq].key == (int) i + 1) | |
3736 | { | |
3737 | dist = copy->subs[eq].coef[0]; | |
3738 | goto found_dist; | |
3739 | } | |
3740 | } | |
3741 | ||
3742 | found_dist:; | |
3743 | /* Save the lexicographically positive distance vector. */ | |
3744 | if (dist >= 0) | |
3745 | { | |
3746 | lambda_vector dist_v = lambda_vector_new (DDR_NB_LOOPS (ddr)); | |
3747 | lambda_vector dir_v = lambda_vector_new (DDR_NB_LOOPS (ddr)); | |
3748 | ||
3749 | dist_v[i] = dist; | |
3750 | ||
3751 | for (eq = 0; eq < copy->num_subs; eq++) | |
3752 | if (copy->subs[eq].key > 0) | |
3753 | { | |
3754 | dist = copy->subs[eq].coef[0]; | |
3755 | dist_v[copy->subs[eq].key - 1] = dist; | |
3756 | } | |
3757 | ||
3758 | for (j = 0; j < DDR_NB_LOOPS (ddr); j++) | |
3759 | dir_v[j] = dir_from_dist (dist_v[j]); | |
3760 | ||
3761 | save_dist_v (ddr, dist_v); | |
3762 | save_dir_v (ddr, dir_v); | |
3763 | } | |
3764 | ||
3765 | next_problem:; | |
3766 | omega_free_problem (copy); | |
3767 | } | |
3768 | } | |
3769 | ||
3770 | /* This is called for each subscript of a tuple of data references: | |
3771 | insert an equality for representing the conflicts. */ | |
3772 | ||
3773 | static bool | |
3774 | omega_setup_subscript (tree access_fun_a, tree access_fun_b, | |
3775 | struct data_dependence_relation *ddr, | |
3776 | omega_pb pb, bool *maybe_dependent) | |
3777 | { | |
3778 | int eq; | |
33b30201 SP |
3779 | tree type = signed_type_for_types (TREE_TYPE (access_fun_a), |
3780 | TREE_TYPE (access_fun_b)); | |
726a989a RB |
3781 | tree fun_a = chrec_convert (type, access_fun_a, NULL); |
3782 | tree fun_b = chrec_convert (type, access_fun_b, NULL); | |
33b30201 | 3783 | tree difference = chrec_fold_minus (type, fun_a, fun_b); |
5a1f5f9a | 3784 | tree minus_one; |
3d8864c0 SP |
3785 | |
3786 | /* When the fun_a - fun_b is not constant, the dependence is not | |
3787 | captured by the classic distance vector representation. */ | |
3788 | if (TREE_CODE (difference) != INTEGER_CST) | |
3789 | return false; | |
3790 | ||
3791 | /* ZIV test. */ | |
3792 | if (ziv_subscript_p (fun_a, fun_b) && !integer_zerop (difference)) | |
3793 | { | |
3794 | /* There is no dependence. */ | |
3795 | *maybe_dependent = false; | |
3796 | return true; | |
3797 | } | |
3798 | ||
5a1f5f9a SP |
3799 | minus_one = build_int_cst (type, -1); |
3800 | fun_b = chrec_fold_multiply (type, fun_b, minus_one); | |
3d8864c0 SP |
3801 | |
3802 | eq = omega_add_zero_eq (pb, omega_black); | |
3803 | if (!init_omega_eq_with_af (pb, eq, DDR_NB_LOOPS (ddr), fun_a, ddr) | |
3804 | || !init_omega_eq_with_af (pb, eq, 0, fun_b, ddr)) | |
3805 | /* There is probably a dependence, but the system of | |
3806 | constraints cannot be built: answer "don't know". */ | |
3807 | return false; | |
3808 | ||
3809 | /* GCD test. */ | |
3810 | if (DDR_NB_LOOPS (ddr) != 0 && pb->eqs[eq].coef[0] | |
b8698a0f | 3811 | && !int_divides_p (lambda_vector_gcd |
3d8864c0 SP |
3812 | ((lambda_vector) &(pb->eqs[eq].coef[1]), |
3813 | 2 * DDR_NB_LOOPS (ddr)), | |
3814 | pb->eqs[eq].coef[0])) | |
3815 | { | |
3816 | /* There is no dependence. */ | |
3817 | *maybe_dependent = false; | |
3818 | return true; | |
3819 | } | |
3820 | ||
3821 | return true; | |
3822 | } | |
3823 | ||
3824 | /* Helper function, same as init_omega_for_ddr but specialized for | |
3825 | data references A and B. */ | |
3826 | ||
3827 | static bool | |
3828 | init_omega_for_ddr_1 (struct data_reference *dra, struct data_reference *drb, | |
3829 | struct data_dependence_relation *ddr, | |
3830 | omega_pb pb, bool *maybe_dependent) | |
3831 | { | |
3832 | unsigned i; | |
3833 | int ineq; | |
3834 | struct loop *loopi; | |
3835 | unsigned nb_loops = DDR_NB_LOOPS (ddr); | |
3836 | ||
3837 | /* Insert an equality per subscript. */ | |
3838 | for (i = 0; i < DDR_NUM_SUBSCRIPTS (ddr); i++) | |
3839 | { | |
3840 | if (!omega_setup_subscript (DR_ACCESS_FN (dra, i), DR_ACCESS_FN (drb, i), | |
3841 | ddr, pb, maybe_dependent)) | |
3842 | return false; | |
3843 | else if (*maybe_dependent == false) | |
3844 | { | |
3845 | /* There is no dependence. */ | |
3846 | DDR_ARE_DEPENDENT (ddr) = chrec_known; | |
3847 | return true; | |
3848 | } | |
3849 | } | |
3850 | ||
3851 | /* Insert inequalities: constraints corresponding to the iteration | |
3852 | domain, i.e. the loops surrounding the references "loop_x" and | |
3853 | the distance variables "dx". The layout of the OMEGA | |
3854 | representation is as follows: | |
3855 | - coef[0] is the constant | |
3856 | - coef[1..nb_loops] are the protected variables that will not be | |
3857 | removed by the solver: the "dx" | |
3858 | - coef[nb_loops + 1, 2*nb_loops] are the loop variables: "loop_x". | |
3859 | */ | |
b8698a0f | 3860 | for (i = 0; i <= DDR_INNER_LOOP (ddr) |
3d8864c0 SP |
3861 | && VEC_iterate (loop_p, DDR_LOOP_NEST (ddr), i, loopi); i++) |
3862 | { | |
652c4c71 | 3863 | HOST_WIDE_INT nbi = max_stmt_executions_int (loopi); |
3d8864c0 SP |
3864 | |
3865 | /* 0 <= loop_x */ | |
3866 | ineq = omega_add_zero_geq (pb, omega_black); | |
3867 | pb->geqs[ineq].coef[i + nb_loops + 1] = 1; | |
3868 | ||
3869 | /* 0 <= loop_x + dx */ | |
3870 | ineq = omega_add_zero_geq (pb, omega_black); | |
3871 | pb->geqs[ineq].coef[i + nb_loops + 1] = 1; | |
3872 | pb->geqs[ineq].coef[i + 1] = 1; | |
3873 | ||
3874 | if (nbi != -1) | |
3875 | { | |
3876 | /* loop_x <= nb_iters */ | |
3877 | ineq = omega_add_zero_geq (pb, omega_black); | |
3878 | pb->geqs[ineq].coef[i + nb_loops + 1] = -1; | |
3879 | pb->geqs[ineq].coef[0] = nbi; | |
3880 | ||
3881 | /* loop_x + dx <= nb_iters */ | |
3882 | ineq = omega_add_zero_geq (pb, omega_black); | |
3883 | pb->geqs[ineq].coef[i + nb_loops + 1] = -1; | |
3884 | pb->geqs[ineq].coef[i + 1] = -1; | |
3885 | pb->geqs[ineq].coef[0] = nbi; | |
3886 | ||
3887 | /* A step "dx" bigger than nb_iters is not feasible, so | |
3888 | add "0 <= nb_iters + dx", */ | |
3889 | ineq = omega_add_zero_geq (pb, omega_black); | |
3890 | pb->geqs[ineq].coef[i + 1] = 1; | |
3891 | pb->geqs[ineq].coef[0] = nbi; | |
3892 | /* and "dx <= nb_iters". */ | |
3893 | ineq = omega_add_zero_geq (pb, omega_black); | |
3894 | pb->geqs[ineq].coef[i + 1] = -1; | |
3895 | pb->geqs[ineq].coef[0] = nbi; | |
3896 | } | |
3897 | } | |
3898 | ||
3899 | omega_extract_distance_vectors (pb, ddr); | |
3900 | ||
3901 | return true; | |
3902 | } | |
3903 | ||
3904 | /* Sets up the Omega dependence problem for the data dependence | |
3905 | relation DDR. Returns false when the constraint system cannot be | |
3906 | built, ie. when the test answers "don't know". Returns true | |
3907 | otherwise, and when independence has been proved (using one of the | |
3908 | trivial dependence test), set MAYBE_DEPENDENT to false, otherwise | |
3909 | set MAYBE_DEPENDENT to true. | |
3910 | ||
3911 | Example: for setting up the dependence system corresponding to the | |
b8698a0f | 3912 | conflicting accesses |
3d8864c0 SP |
3913 | |
3914 | | loop_i | |
3915 | | loop_j | |
3916 | | A[i, i+1] = ... | |
3917 | | ... A[2*j, 2*(i + j)] | |
3918 | | endloop_j | |
3919 | | endloop_i | |
b8698a0f | 3920 | |
3d8864c0 SP |
3921 | the following constraints come from the iteration domain: |
3922 | ||
3923 | 0 <= i <= Ni | |
3924 | 0 <= i + di <= Ni | |
3925 | 0 <= j <= Nj | |
3926 | 0 <= j + dj <= Nj | |
3927 | ||
3928 | where di, dj are the distance variables. The constraints | |
3929 | representing the conflicting elements are: | |
3930 | ||
3931 | i = 2 * (j + dj) | |
3932 | i + 1 = 2 * (i + di + j + dj) | |
3933 | ||
3934 | For asking that the resulting distance vector (di, dj) be | |
3935 | lexicographically positive, we insert the constraint "di >= 0". If | |
3936 | "di = 0" in the solution, we fix that component to zero, and we | |
3937 | look at the inner loops: we set a new problem where all the outer | |
3938 | loop distances are zero, and fix this inner component to be | |
3939 | positive. When one of the components is positive, we save that | |
3940 | distance, and set a new problem where the distance on this loop is | |
3941 | zero, searching for other distances in the inner loops. Here is | |
3942 | the classic example that illustrates that we have to set for each | |
3943 | inner loop a new problem: | |
3944 | ||
3945 | | loop_1 | |
3946 | | loop_2 | |
3947 | | A[10] | |
3948 | | endloop_2 | |
3949 | | endloop_1 | |
3950 | ||
3951 | we have to save two distances (1, 0) and (0, 1). | |
3952 | ||
3953 | Given two array references, refA and refB, we have to set the | |
3954 | dependence problem twice, refA vs. refB and refB vs. refA, and we | |
3955 | cannot do a single test, as refB might occur before refA in the | |
3956 | inner loops, and the contrary when considering outer loops: ex. | |
3957 | ||
3958 | | loop_0 | |
3959 | | loop_1 | |
3960 | | loop_2 | |
3961 | | T[{1,+,1}_2][{1,+,1}_1] // refA | |
3962 | | T[{2,+,1}_2][{0,+,1}_1] // refB | |
3963 | | endloop_2 | |
3964 | | endloop_1 | |
3965 | | endloop_0 | |
3966 | ||
3967 | refB touches the elements in T before refA, and thus for the same | |
3968 | loop_0 refB precedes refA: ie. the distance vector (0, 1, -1) | |
3969 | but for successive loop_0 iterations, we have (1, -1, 1) | |
3970 | ||
3971 | The Omega solver expects the distance variables ("di" in the | |
3972 | previous example) to come first in the constraint system (as | |
3973 | variables to be protected, or "safe" variables), the constraint | |
3974 | system is built using the following layout: | |
3975 | ||
3976 | "cst | distance vars | index vars". | |
3977 | */ | |
3978 | ||
3979 | static bool | |
3980 | init_omega_for_ddr (struct data_dependence_relation *ddr, | |
3981 | bool *maybe_dependent) | |
3982 | { | |
3983 | omega_pb pb; | |
3984 | bool res = false; | |
3985 | ||
3986 | *maybe_dependent = true; | |
3987 | ||
3988 | if (same_access_functions (ddr)) | |
3989 | { | |
3990 | unsigned j; | |
3991 | lambda_vector dir_v; | |
3992 | ||
3993 | /* Save the 0 vector. */ | |
3994 | save_dist_v (ddr, lambda_vector_new (DDR_NB_LOOPS (ddr))); | |
3995 | dir_v = lambda_vector_new (DDR_NB_LOOPS (ddr)); | |
3996 | for (j = 0; j < DDR_NB_LOOPS (ddr); j++) | |
3997 | dir_v[j] = dir_equal; | |
3998 | save_dir_v (ddr, dir_v); | |
3999 | ||
4000 | /* Save the dependences carried by outer loops. */ | |
4001 | pb = omega_alloc_problem (2 * DDR_NB_LOOPS (ddr), DDR_NB_LOOPS (ddr)); | |
4002 | res = init_omega_for_ddr_1 (DDR_A (ddr), DDR_B (ddr), ddr, pb, | |
4003 | maybe_dependent); | |
4004 | omega_free_problem (pb); | |
4005 | return res; | |
4006 | } | |
4007 | ||
4008 | /* Omega expects the protected variables (those that have to be kept | |
4009 | after elimination) to appear first in the constraint system. | |
4010 | These variables are the distance variables. In the following | |
4011 | initialization we declare NB_LOOPS safe variables, and the total | |
4012 | number of variables for the constraint system is 2*NB_LOOPS. */ | |
4013 | pb = omega_alloc_problem (2 * DDR_NB_LOOPS (ddr), DDR_NB_LOOPS (ddr)); | |
4014 | res = init_omega_for_ddr_1 (DDR_A (ddr), DDR_B (ddr), ddr, pb, | |
4015 | maybe_dependent); | |
4016 | omega_free_problem (pb); | |
4017 | ||
4018 | /* Stop computation if not decidable, or no dependence. */ | |
4019 | if (res == false || *maybe_dependent == false) | |
4020 | return res; | |
4021 | ||
4022 | pb = omega_alloc_problem (2 * DDR_NB_LOOPS (ddr), DDR_NB_LOOPS (ddr)); | |
4023 | res = init_omega_for_ddr_1 (DDR_B (ddr), DDR_A (ddr), ddr, pb, | |
4024 | maybe_dependent); | |
4025 | omega_free_problem (pb); | |
4026 | ||
4027 | return res; | |
4028 | } | |
4029 | ||
4030 | /* Return true when DDR contains the same information as that stored | |
4031 | in DIR_VECTS and in DIST_VECTS, return false otherwise. */ | |
4032 | ||
4033 | static bool | |
4034 | ddr_consistent_p (FILE *file, | |
4035 | struct data_dependence_relation *ddr, | |
4036 | VEC (lambda_vector, heap) *dist_vects, | |
4037 | VEC (lambda_vector, heap) *dir_vects) | |
4038 | { | |
4039 | unsigned int i, j; | |
4040 | ||
4041 | /* If dump_file is set, output there. */ | |
4042 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
4043 | file = dump_file; | |
4044 | ||
4045 | if (VEC_length (lambda_vector, dist_vects) != DDR_NUM_DIST_VECTS (ddr)) | |
4046 | { | |
4047 | lambda_vector b_dist_v; | |
4048 | fprintf (file, "\n(Number of distance vectors differ: Banerjee has %d, Omega has %d.\n", | |
4049 | VEC_length (lambda_vector, dist_vects), | |
4050 | DDR_NUM_DIST_VECTS (ddr)); | |
4051 | ||
4052 | fprintf (file, "Banerjee dist vectors:\n"); | |
ac47786e | 4053 | FOR_EACH_VEC_ELT (lambda_vector, dist_vects, i, b_dist_v) |
3d8864c0 SP |
4054 | print_lambda_vector (file, b_dist_v, DDR_NB_LOOPS (ddr)); |
4055 | ||
4056 | fprintf (file, "Omega dist vectors:\n"); | |
4057 | for (i = 0; i < DDR_NUM_DIST_VECTS (ddr); i++) | |
4058 | print_lambda_vector (file, DDR_DIST_VECT (ddr, i), DDR_NB_LOOPS (ddr)); | |
4059 | ||
4060 | fprintf (file, "data dependence relation:\n"); | |
4061 | dump_data_dependence_relation (file, ddr); | |
4062 | ||
4063 | fprintf (file, ")\n"); | |
4064 | return false; | |
4065 | } | |
4066 | ||
4067 | if (VEC_length (lambda_vector, dir_vects) != DDR_NUM_DIR_VECTS (ddr)) | |
4068 | { | |
4069 | fprintf (file, "\n(Number of direction vectors differ: Banerjee has %d, Omega has %d.)\n", | |
4070 | VEC_length (lambda_vector, dir_vects), | |
4071 | DDR_NUM_DIR_VECTS (ddr)); | |
4072 | return false; | |
4073 | } | |
4074 | ||
4075 | for (i = 0; i < DDR_NUM_DIST_VECTS (ddr); i++) | |
4076 | { | |
4077 | lambda_vector a_dist_v; | |
4078 | lambda_vector b_dist_v = DDR_DIST_VECT (ddr, i); | |
4079 | ||
4080 | /* Distance vectors are not ordered in the same way in the DDR | |
4081 | and in the DIST_VECTS: search for a matching vector. */ | |
ac47786e | 4082 | FOR_EACH_VEC_ELT (lambda_vector, dist_vects, j, a_dist_v) |
3d8864c0 SP |
4083 | if (lambda_vector_equal (a_dist_v, b_dist_v, DDR_NB_LOOPS (ddr))) |
4084 | break; | |
4085 | ||
4086 | if (j == VEC_length (lambda_vector, dist_vects)) | |
4087 | { | |
4088 | fprintf (file, "\n(Dist vectors from the first dependence analyzer:\n"); | |
4089 | print_dist_vectors (file, dist_vects, DDR_NB_LOOPS (ddr)); | |
4090 | fprintf (file, "not found in Omega dist vectors:\n"); | |
4091 | print_dist_vectors (file, DDR_DIST_VECTS (ddr), DDR_NB_LOOPS (ddr)); | |
4092 | fprintf (file, "data dependence relation:\n"); | |
4093 | dump_data_dependence_relation (file, ddr); | |
4094 | fprintf (file, ")\n"); | |
4095 | } | |
4096 | } | |
4097 | ||
4098 | for (i = 0; i < DDR_NUM_DIR_VECTS (ddr); i++) | |
4099 | { | |
4100 | lambda_vector a_dir_v; | |
4101 | lambda_vector b_dir_v = DDR_DIR_VECT (ddr, i); | |
4102 | ||
4103 | /* Direction vectors are not ordered in the same way in the DDR | |
4104 | and in the DIR_VECTS: search for a matching vector. */ | |
ac47786e | 4105 | FOR_EACH_VEC_ELT (lambda_vector, dir_vects, j, a_dir_v) |
3d8864c0 SP |
4106 | if (lambda_vector_equal (a_dir_v, b_dir_v, DDR_NB_LOOPS (ddr))) |
4107 | break; | |
4108 | ||
4109 | if (j == VEC_length (lambda_vector, dist_vects)) | |
4110 | { | |
4111 | fprintf (file, "\n(Dir vectors from the first dependence analyzer:\n"); | |
4112 | print_dir_vectors (file, dir_vects, DDR_NB_LOOPS (ddr)); | |
4113 | fprintf (file, "not found in Omega dir vectors:\n"); | |
4114 | print_dir_vectors (file, DDR_DIR_VECTS (ddr), DDR_NB_LOOPS (ddr)); | |
4115 | fprintf (file, "data dependence relation:\n"); | |
4116 | dump_data_dependence_relation (file, ddr); | |
4117 | fprintf (file, ")\n"); | |
4118 | } | |
4119 | } | |
4120 | ||
b8698a0f | 4121 | return true; |
3d8864c0 SP |
4122 | } |
4123 | ||
da9a21f4 SP |
4124 | /* This computes the affine dependence relation between A and B with |
4125 | respect to LOOP_NEST. CHREC_KNOWN is used for representing the | |
4126 | independence between two accesses, while CHREC_DONT_KNOW is used | |
4127 | for representing the unknown relation. | |
b8698a0f | 4128 | |
56cf8686 SP |
4129 | Note that it is possible to stop the computation of the dependence |
4130 | relation the first time we detect a CHREC_KNOWN element for a given | |
4131 | subscript. */ | |
4132 | ||
0ff4040e | 4133 | static void |
da9a21f4 SP |
4134 | compute_affine_dependence (struct data_dependence_relation *ddr, |
4135 | struct loop *loop_nest) | |
56cf8686 SP |
4136 | { |
4137 | struct data_reference *dra = DDR_A (ddr); | |
4138 | struct data_reference *drb = DDR_B (ddr); | |
b8698a0f | 4139 | |
56cf8686 SP |
4140 | if (dump_file && (dump_flags & TDF_DETAILS)) |
4141 | { | |
36d59cf7 | 4142 | fprintf (dump_file, "(compute_affine_dependence\n"); |
c4ddde1b RG |
4143 | fprintf (dump_file, " stmt_a: "); |
4144 | print_gimple_stmt (dump_file, DR_STMT (dra), 0, TDF_SLIM); | |
4145 | fprintf (dump_file, " stmt_b: "); | |
4146 | print_gimple_stmt (dump_file, DR_STMT (drb), 0, TDF_SLIM); | |
56cf8686 | 4147 | } |
0ff4040e | 4148 | |
56cf8686 | 4149 | /* Analyze only when the dependence relation is not yet known. */ |
1a4571cb | 4150 | if (DDR_ARE_DEPENDENT (ddr) == NULL_TREE) |
56cf8686 | 4151 | { |
0ff4040e SP |
4152 | dependence_stats.num_dependence_tests++; |
4153 | ||
da9a21f4 SP |
4154 | if (access_functions_are_affine_or_constant_p (dra, loop_nest) |
4155 | && access_functions_are_affine_or_constant_p (drb, loop_nest)) | |
3d8864c0 SP |
4156 | { |
4157 | if (flag_check_data_deps) | |
4158 | { | |
4159 | /* Compute the dependences using the first algorithm. */ | |
da9a21f4 | 4160 | subscript_dependence_tester (ddr, loop_nest); |
3d8864c0 SP |
4161 | |
4162 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
4163 | { | |
4164 | fprintf (dump_file, "\n\nBanerjee Analyzer\n"); | |
4165 | dump_data_dependence_relation (dump_file, ddr); | |
4166 | } | |
4167 | ||
4168 | if (DDR_ARE_DEPENDENT (ddr) == NULL_TREE) | |
4169 | { | |
4170 | bool maybe_dependent; | |
4171 | VEC (lambda_vector, heap) *dir_vects, *dist_vects; | |
4172 | ||
4173 | /* Save the result of the first DD analyzer. */ | |
4174 | dist_vects = DDR_DIST_VECTS (ddr); | |
4175 | dir_vects = DDR_DIR_VECTS (ddr); | |
4176 | ||
4177 | /* Reset the information. */ | |
4178 | DDR_DIST_VECTS (ddr) = NULL; | |
4179 | DDR_DIR_VECTS (ddr) = NULL; | |
4180 | ||
4181 | /* Compute the same information using Omega. */ | |
4182 | if (!init_omega_for_ddr (ddr, &maybe_dependent)) | |
4183 | goto csys_dont_know; | |
4184 | ||
4185 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
4186 | { | |
4187 | fprintf (dump_file, "Omega Analyzer\n"); | |
4188 | dump_data_dependence_relation (dump_file, ddr); | |
4189 | } | |
4190 | ||
4191 | /* Check that we get the same information. */ | |
4192 | if (maybe_dependent) | |
4193 | gcc_assert (ddr_consistent_p (stderr, ddr, dist_vects, | |
4194 | dir_vects)); | |
4195 | } | |
4196 | } | |
4197 | else | |
da9a21f4 | 4198 | subscript_dependence_tester (ddr, loop_nest); |
3d8864c0 | 4199 | } |
b8698a0f | 4200 | |
56cf8686 SP |
4201 | /* As a last case, if the dependence cannot be determined, or if |
4202 | the dependence is considered too difficult to determine, answer | |
4203 | "don't know". */ | |
4204 | else | |
0ff4040e | 4205 | { |
3d8864c0 | 4206 | csys_dont_know:; |
0ff4040e SP |
4207 | dependence_stats.num_dependence_undetermined++; |
4208 | ||
4209 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
4210 | { | |
4211 | fprintf (dump_file, "Data ref a:\n"); | |
4212 | dump_data_reference (dump_file, dra); | |
4213 | fprintf (dump_file, "Data ref b:\n"); | |
4214 | dump_data_reference (dump_file, drb); | |
4215 | fprintf (dump_file, "affine dependence test not usable: access function not affine or constant.\n"); | |
4216 | } | |
4217 | finalize_ddr_dependent (ddr, chrec_dont_know); | |
4218 | } | |
56cf8686 | 4219 | } |
b8698a0f | 4220 | |
56cf8686 | 4221 | if (dump_file && (dump_flags & TDF_DETAILS)) |
c4ddde1b RG |
4222 | { |
4223 | if (DDR_ARE_DEPENDENT (ddr) == chrec_known) | |
4224 | fprintf (dump_file, ") -> no dependence\n"); | |
4225 | else if (DDR_ARE_DEPENDENT (ddr) == chrec_dont_know) | |
4226 | fprintf (dump_file, ") -> dependence analysis failed\n"); | |
4227 | else | |
4228 | fprintf (dump_file, ")\n"); | |
4229 | } | |
56cf8686 SP |
4230 | } |
4231 | ||
ba42e045 SP |
4232 | /* Compute in DEPENDENCE_RELATIONS the data dependence graph for all |
4233 | the data references in DATAREFS, in the LOOP_NEST. When | |
ebf78a47 | 4234 | COMPUTE_SELF_AND_RR is FALSE, don't compute read-read and self |
3881dee9 AB |
4235 | relations. Return true when successful, i.e. data references number |
4236 | is small enough to be handled. */ | |
56cf8686 | 4237 | |
3881dee9 | 4238 | bool |
ebf78a47 | 4239 | compute_all_dependences (VEC (data_reference_p, heap) *datarefs, |
a84481aa | 4240 | VEC (ddr_p, heap) **dependence_relations, |
ba42e045 | 4241 | VEC (loop_p, heap) *loop_nest, |
ebf78a47 | 4242 | bool compute_self_and_rr) |
56cf8686 | 4243 | { |
ebf78a47 SP |
4244 | struct data_dependence_relation *ddr; |
4245 | struct data_reference *a, *b; | |
4246 | unsigned int i, j; | |
56cf8686 | 4247 | |
3881dee9 AB |
4248 | if ((int) VEC_length (data_reference_p, datarefs) |
4249 | > PARAM_VALUE (PARAM_LOOP_MAX_DATAREFS_FOR_DATADEPS)) | |
4250 | { | |
4251 | struct data_dependence_relation *ddr; | |
4252 | ||
4253 | /* Insert a single relation into dependence_relations: | |
4254 | chrec_dont_know. */ | |
4255 | ddr = initialize_data_dependence_relation (NULL, NULL, loop_nest); | |
4256 | VEC_safe_push (ddr_p, heap, *dependence_relations, ddr); | |
4257 | return false; | |
4258 | } | |
4259 | ||
ac47786e | 4260 | FOR_EACH_VEC_ELT (data_reference_p, datarefs, i, a) |
ebf78a47 | 4261 | for (j = i + 1; VEC_iterate (data_reference_p, datarefs, j, b); j++) |
b0af49c4 | 4262 | if (DR_IS_WRITE (a) || DR_IS_WRITE (b) || compute_self_and_rr) |
ebf78a47 SP |
4263 | { |
4264 | ddr = initialize_data_dependence_relation (a, b, loop_nest); | |
a84481aa | 4265 | VEC_safe_push (ddr_p, heap, *dependence_relations, ddr); |
a70d6342 IR |
4266 | if (loop_nest) |
4267 | compute_affine_dependence (ddr, VEC_index (loop_p, loop_nest, 0)); | |
ebf78a47 | 4268 | } |
789246d7 | 4269 | |
ebf78a47 | 4270 | if (compute_self_and_rr) |
ac47786e | 4271 | FOR_EACH_VEC_ELT (data_reference_p, datarefs, i, a) |
56cf8686 | 4272 | { |
ebf78a47 | 4273 | ddr = initialize_data_dependence_relation (a, a, loop_nest); |
a84481aa | 4274 | VEC_safe_push (ddr_p, heap, *dependence_relations, ddr); |
1a4571cb RL |
4275 | if (loop_nest) |
4276 | compute_affine_dependence (ddr, VEC_index (loop_p, loop_nest, 0)); | |
56cf8686 | 4277 | } |
3881dee9 AB |
4278 | |
4279 | return true; | |
56cf8686 SP |
4280 | } |
4281 | ||
aeb83f09 RG |
4282 | /* Describes a location of a memory reference. */ |
4283 | ||
4284 | typedef struct data_ref_loc_d | |
4285 | { | |
4286 | /* Position of the memory reference. */ | |
4287 | tree *pos; | |
4288 | ||
4289 | /* True if the memory reference is read. */ | |
4290 | bool is_read; | |
4291 | } data_ref_loc; | |
4292 | ||
4293 | DEF_VEC_O (data_ref_loc); | |
4294 | DEF_VEC_ALLOC_O (data_ref_loc, heap); | |
4295 | ||
946e1bc7 ZD |
4296 | /* Stores the locations of memory references in STMT to REFERENCES. Returns |
4297 | true if STMT clobbers memory, false otherwise. */ | |
4298 | ||
aeb83f09 | 4299 | static bool |
726a989a | 4300 | get_references_in_stmt (gimple stmt, VEC (data_ref_loc, heap) **references) |
946e1bc7 ZD |
4301 | { |
4302 | bool clobbers_memory = false; | |
4303 | data_ref_loc *ref; | |
726a989a RB |
4304 | tree *op0, *op1; |
4305 | enum gimple_code stmt_code = gimple_code (stmt); | |
946e1bc7 ZD |
4306 | |
4307 | *references = NULL; | |
4308 | ||
4309 | /* ASM_EXPR and CALL_EXPR may embed arbitrary side effects. | |
4310 | Calls have side-effects, except those to const or pure | |
4311 | functions. */ | |
726a989a RB |
4312 | if ((stmt_code == GIMPLE_CALL |
4313 | && !(gimple_call_flags (stmt) & (ECF_CONST | ECF_PURE))) | |
4314 | || (stmt_code == GIMPLE_ASM | |
06e1d03d | 4315 | && (gimple_asm_volatile_p (stmt) || gimple_vuse (stmt)))) |
946e1bc7 ZD |
4316 | clobbers_memory = true; |
4317 | ||
5006671f | 4318 | if (!gimple_vuse (stmt)) |
946e1bc7 ZD |
4319 | return clobbers_memory; |
4320 | ||
726a989a | 4321 | if (stmt_code == GIMPLE_ASSIGN) |
946e1bc7 | 4322 | { |
c8ae0bec | 4323 | tree base; |
726a989a RB |
4324 | op0 = gimple_assign_lhs_ptr (stmt); |
4325 | op1 = gimple_assign_rhs1_ptr (stmt); | |
b8698a0f | 4326 | |
946e1bc7 | 4327 | if (DECL_P (*op1) |
c8ae0bec RG |
4328 | || (REFERENCE_CLASS_P (*op1) |
4329 | && (base = get_base_address (*op1)) | |
4330 | && TREE_CODE (base) != SSA_NAME)) | |
946e1bc7 ZD |
4331 | { |
4332 | ref = VEC_safe_push (data_ref_loc, heap, *references, NULL); | |
4333 | ref->pos = op1; | |
4334 | ref->is_read = true; | |
4335 | } | |
946e1bc7 | 4336 | } |
726a989a | 4337 | else if (stmt_code == GIMPLE_CALL) |
946e1bc7 | 4338 | { |
1b14d815 | 4339 | unsigned i, n; |
ac84e05e | 4340 | |
1b14d815 RS |
4341 | op0 = gimple_call_lhs_ptr (stmt); |
4342 | n = gimple_call_num_args (stmt); | |
ac84e05e | 4343 | for (i = 0; i < n; i++) |
946e1bc7 | 4344 | { |
1b14d815 | 4345 | op1 = gimple_call_arg_ptr (stmt, i); |
ac84e05e | 4346 | |
1b14d815 RS |
4347 | if (DECL_P (*op1) |
4348 | || (REFERENCE_CLASS_P (*op1) && get_base_address (*op1))) | |
946e1bc7 ZD |
4349 | { |
4350 | ref = VEC_safe_push (data_ref_loc, heap, *references, NULL); | |
1b14d815 | 4351 | ref->pos = op1; |
946e1bc7 ZD |
4352 | ref->is_read = true; |
4353 | } | |
4354 | } | |
4355 | } | |
1b14d815 RS |
4356 | else |
4357 | return clobbers_memory; | |
946e1bc7 | 4358 | |
1b14d815 RS |
4359 | if (*op0 |
4360 | && (DECL_P (*op0) | |
4361 | || (REFERENCE_CLASS_P (*op0) && get_base_address (*op0)))) | |
4362 | { | |
4363 | ref = VEC_safe_push (data_ref_loc, heap, *references, NULL); | |
4364 | ref->pos = op0; | |
4365 | ref->is_read = false; | |
4366 | } | |
946e1bc7 ZD |
4367 | return clobbers_memory; |
4368 | } | |
4369 | ||
4370 | /* Stores the data references in STMT to DATAREFS. If there is an unanalyzable | |
3cb960c7 | 4371 | reference, returns false, otherwise returns true. NEST is the outermost |
f8bf9252 | 4372 | loop of the loop nest in which the references should be analyzed. */ |
946e1bc7 | 4373 | |
f8bf9252 | 4374 | bool |
726a989a | 4375 | find_data_references_in_stmt (struct loop *nest, gimple stmt, |
946e1bc7 ZD |
4376 | VEC (data_reference_p, heap) **datarefs) |
4377 | { | |
4378 | unsigned i; | |
4379 | VEC (data_ref_loc, heap) *references; | |
4380 | data_ref_loc *ref; | |
4381 | bool ret = true; | |
4382 | data_reference_p dr; | |
4383 | ||
4384 | if (get_references_in_stmt (stmt, &references)) | |
4385 | { | |
4386 | VEC_free (data_ref_loc, heap, references); | |
4387 | return false; | |
4388 | } | |
4389 | ||
ac47786e | 4390 | FOR_EACH_VEC_ELT (data_ref_loc, references, i, ref) |
946e1bc7 | 4391 | { |
5c640e29 SP |
4392 | dr = create_data_ref (nest, loop_containing_stmt (stmt), |
4393 | *ref->pos, stmt, ref->is_read); | |
bbc8a8dc | 4394 | gcc_assert (dr != NULL); |
bbc8a8dc | 4395 | VEC_safe_push (data_reference_p, heap, *datarefs, dr); |
946e1bc7 ZD |
4396 | } |
4397 | VEC_free (data_ref_loc, heap, references); | |
4398 | return ret; | |
4399 | } | |
4400 | ||
5c640e29 SP |
4401 | /* Stores the data references in STMT to DATAREFS. If there is an |
4402 | unanalyzable reference, returns false, otherwise returns true. | |
4403 | NEST is the outermost loop of the loop nest in which the references | |
4404 | should be instantiated, LOOP is the loop in which the references | |
4405 | should be analyzed. */ | |
ed91d661 SP |
4406 | |
4407 | bool | |
5c640e29 | 4408 | graphite_find_data_references_in_stmt (loop_p nest, loop_p loop, gimple stmt, |
ed91d661 SP |
4409 | VEC (data_reference_p, heap) **datarefs) |
4410 | { | |
4411 | unsigned i; | |
4412 | VEC (data_ref_loc, heap) *references; | |
4413 | data_ref_loc *ref; | |
4414 | bool ret = true; | |
4415 | data_reference_p dr; | |
4416 | ||
4417 | if (get_references_in_stmt (stmt, &references)) | |
4418 | { | |
4419 | VEC_free (data_ref_loc, heap, references); | |
4420 | return false; | |
4421 | } | |
4422 | ||
ac47786e | 4423 | FOR_EACH_VEC_ELT (data_ref_loc, references, i, ref) |
ed91d661 | 4424 | { |
5c640e29 | 4425 | dr = create_data_ref (nest, loop, *ref->pos, stmt, ref->is_read); |
ed91d661 SP |
4426 | gcc_assert (dr != NULL); |
4427 | VEC_safe_push (data_reference_p, heap, *datarefs, dr); | |
4428 | } | |
4429 | ||
4430 | VEC_free (data_ref_loc, heap, references); | |
4431 | return ret; | |
4432 | } | |
4433 | ||
a70d6342 IR |
4434 | /* Search the data references in LOOP, and record the information into |
4435 | DATAREFS. Returns chrec_dont_know when failing to analyze a | |
4436 | difficult case, returns NULL_TREE otherwise. */ | |
4437 | ||
bfe068c3 | 4438 | tree |
a70d6342 IR |
4439 | find_data_references_in_bb (struct loop *loop, basic_block bb, |
4440 | VEC (data_reference_p, heap) **datarefs) | |
4441 | { | |
4442 | gimple_stmt_iterator bsi; | |
4443 | ||
4444 | for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi)) | |
4445 | { | |
4446 | gimple stmt = gsi_stmt (bsi); | |
4447 | ||
4448 | if (!find_data_references_in_stmt (loop, stmt, datarefs)) | |
4449 | { | |
4450 | struct data_reference *res; | |
4451 | res = XCNEW (struct data_reference); | |
4452 | VEC_safe_push (data_reference_p, heap, *datarefs, res); | |
4453 | ||
4454 | return chrec_dont_know; | |
4455 | } | |
4456 | } | |
4457 | ||
4458 | return NULL_TREE; | |
4459 | } | |
4460 | ||
56cf8686 SP |
4461 | /* Search the data references in LOOP, and record the information into |
4462 | DATAREFS. Returns chrec_dont_know when failing to analyze a | |
4463 | difficult case, returns NULL_TREE otherwise. | |
3cb960c7 | 4464 | |
464f49d8 DB |
4465 | TODO: This function should be made smarter so that it can handle address |
4466 | arithmetic as if they were array accesses, etc. */ | |
56cf8686 | 4467 | |
3881dee9 | 4468 | static tree |
ebf78a47 | 4469 | find_data_references_in_loop (struct loop *loop, |
e14b10df | 4470 | VEC (data_reference_p, heap) **datarefs) |
56cf8686 | 4471 | { |
ccbdbf0a JL |
4472 | basic_block bb, *bbs; |
4473 | unsigned int i; | |
86df10e3 | 4474 | |
bbc8a8dc | 4475 | bbs = get_loop_body_in_dom_order (loop); |
ccbdbf0a JL |
4476 | |
4477 | for (i = 0; i < loop->num_nodes; i++) | |
56cf8686 | 4478 | { |
ccbdbf0a JL |
4479 | bb = bbs[i]; |
4480 | ||
a70d6342 IR |
4481 | if (find_data_references_in_bb (loop, bb, datarefs) == chrec_dont_know) |
4482 | { | |
4483 | free (bbs); | |
4484 | return chrec_dont_know; | |
4485 | } | |
56cf8686 | 4486 | } |
ccbdbf0a JL |
4487 | free (bbs); |
4488 | ||
4aad410d | 4489 | return NULL_TREE; |
56cf8686 SP |
4490 | } |
4491 | ||
ba42e045 SP |
4492 | /* Recursive helper function. */ |
4493 | ||
4494 | static bool | |
3ac57120 | 4495 | find_loop_nest_1 (struct loop *loop, VEC (loop_p, heap) **loop_nest) |
ba42e045 SP |
4496 | { |
4497 | /* Inner loops of the nest should not contain siblings. Example: | |
4498 | when there are two consecutive loops, | |
4499 | ||
4500 | | loop_0 | |
4501 | | loop_1 | |
4502 | | A[{0, +, 1}_1] | |
4503 | | endloop_1 | |
4504 | | loop_2 | |
4505 | | A[{0, +, 1}_2] | |
4506 | | endloop_2 | |
4507 | | endloop_0 | |
4508 | ||
4509 | the dependence relation cannot be captured by the distance | |
4510 | abstraction. */ | |
4511 | if (loop->next) | |
4512 | return false; | |
56cf8686 | 4513 | |
3ac57120 | 4514 | VEC_safe_push (loop_p, heap, *loop_nest, loop); |
ba42e045 SP |
4515 | if (loop->inner) |
4516 | return find_loop_nest_1 (loop->inner, loop_nest); | |
4517 | return true; | |
4518 | } | |
4519 | ||
4520 | /* Return false when the LOOP is not well nested. Otherwise return | |
4521 | true and insert in LOOP_NEST the loops of the nest. LOOP_NEST will | |
4522 | contain the loops from the outermost to the innermost, as they will | |
4523 | appear in the classic distance vector. */ | |
4524 | ||
5417e022 | 4525 | bool |
3ac57120 | 4526 | find_loop_nest (struct loop *loop, VEC (loop_p, heap) **loop_nest) |
ba42e045 | 4527 | { |
3ac57120 | 4528 | VEC_safe_push (loop_p, heap, *loop_nest, loop); |
ba42e045 SP |
4529 | if (loop->inner) |
4530 | return find_loop_nest_1 (loop->inner, loop_nest); | |
4531 | return true; | |
4532 | } | |
56cf8686 | 4533 | |
9f275479 JS |
4534 | /* Returns true when the data dependences have been computed, false otherwise. |
4535 | Given a loop nest LOOP, the following vectors are returned: | |
b8698a0f L |
4536 | DATAREFS is initialized to all the array elements contained in this loop, |
4537 | DEPENDENCE_RELATIONS contains the relations between the data references. | |
4538 | Compute read-read and self relations if | |
86a07404 | 4539 | COMPUTE_SELF_AND_READ_READ_DEPENDENCES is TRUE. */ |
56cf8686 | 4540 | |
9f275479 | 4541 | bool |
b8698a0f | 4542 | compute_data_dependences_for_loop (struct loop *loop, |
86a07404 | 4543 | bool compute_self_and_read_read_dependences, |
01be8516 | 4544 | VEC (loop_p, heap) **loop_nest, |
e14b10df SP |
4545 | VEC (data_reference_p, heap) **datarefs, |
4546 | VEC (ddr_p, heap) **dependence_relations) | |
56cf8686 | 4547 | { |
9f275479 | 4548 | bool res = true; |
86a07404 | 4549 | |
0ff4040e | 4550 | memset (&dependence_stats, 0, sizeof (dependence_stats)); |
56cf8686 | 4551 | |
b8698a0f | 4552 | /* If the loop nest is not well formed, or one of the data references |
ba42e045 SP |
4553 | is not computable, give up without spending time to compute other |
4554 | dependences. */ | |
3cb960c7 | 4555 | if (!loop |
01be8516 | 4556 | || !find_loop_nest (loop, loop_nest) |
3881dee9 AB |
4557 | || find_data_references_in_loop (loop, datarefs) == chrec_dont_know |
4558 | || !compute_all_dependences (*datarefs, dependence_relations, *loop_nest, | |
4559 | compute_self_and_read_read_dependences)) | |
4560 | res = false; | |
0ff4040e SP |
4561 | |
4562 | if (dump_file && (dump_flags & TDF_STATS)) | |
56cf8686 | 4563 | { |
0ff4040e SP |
4564 | fprintf (dump_file, "Dependence tester statistics:\n"); |
4565 | ||
b8698a0f | 4566 | fprintf (dump_file, "Number of dependence tests: %d\n", |
0ff4040e | 4567 | dependence_stats.num_dependence_tests); |
b8698a0f | 4568 | fprintf (dump_file, "Number of dependence tests classified dependent: %d\n", |
0ff4040e | 4569 | dependence_stats.num_dependence_dependent); |
b8698a0f | 4570 | fprintf (dump_file, "Number of dependence tests classified independent: %d\n", |
0ff4040e | 4571 | dependence_stats.num_dependence_independent); |
b8698a0f | 4572 | fprintf (dump_file, "Number of undetermined dependence tests: %d\n", |
0ff4040e SP |
4573 | dependence_stats.num_dependence_undetermined); |
4574 | ||
b8698a0f | 4575 | fprintf (dump_file, "Number of subscript tests: %d\n", |
0ff4040e | 4576 | dependence_stats.num_subscript_tests); |
b8698a0f | 4577 | fprintf (dump_file, "Number of undetermined subscript tests: %d\n", |
0ff4040e | 4578 | dependence_stats.num_subscript_undetermined); |
b8698a0f | 4579 | fprintf (dump_file, "Number of same subscript function: %d\n", |
0ff4040e SP |
4580 | dependence_stats.num_same_subscript_function); |
4581 | ||
4582 | fprintf (dump_file, "Number of ziv tests: %d\n", | |
4583 | dependence_stats.num_ziv); | |
4584 | fprintf (dump_file, "Number of ziv tests returning dependent: %d\n", | |
4585 | dependence_stats.num_ziv_dependent); | |
4586 | fprintf (dump_file, "Number of ziv tests returning independent: %d\n", | |
4587 | dependence_stats.num_ziv_independent); | |
4588 | fprintf (dump_file, "Number of ziv tests unimplemented: %d\n", | |
b8698a0f | 4589 | dependence_stats.num_ziv_unimplemented); |
0ff4040e | 4590 | |
b8698a0f | 4591 | fprintf (dump_file, "Number of siv tests: %d\n", |
0ff4040e SP |
4592 | dependence_stats.num_siv); |
4593 | fprintf (dump_file, "Number of siv tests returning dependent: %d\n", | |
4594 | dependence_stats.num_siv_dependent); | |
4595 | fprintf (dump_file, "Number of siv tests returning independent: %d\n", | |
4596 | dependence_stats.num_siv_independent); | |
4597 | fprintf (dump_file, "Number of siv tests unimplemented: %d\n", | |
4598 | dependence_stats.num_siv_unimplemented); | |
4599 | ||
b8698a0f | 4600 | fprintf (dump_file, "Number of miv tests: %d\n", |
0ff4040e SP |
4601 | dependence_stats.num_miv); |
4602 | fprintf (dump_file, "Number of miv tests returning dependent: %d\n", | |
4603 | dependence_stats.num_miv_dependent); | |
4604 | fprintf (dump_file, "Number of miv tests returning independent: %d\n", | |
4605 | dependence_stats.num_miv_independent); | |
4606 | fprintf (dump_file, "Number of miv tests unimplemented: %d\n", | |
4607 | dependence_stats.num_miv_unimplemented); | |
9f275479 JS |
4608 | } |
4609 | ||
4610 | return res; | |
56cf8686 SP |
4611 | } |
4612 | ||
b8698a0f | 4613 | /* Returns true when the data dependences for the basic block BB have been |
a70d6342 | 4614 | computed, false otherwise. |
b8698a0f | 4615 | DATAREFS is initialized to all the array elements contained in this basic |
a70d6342 IR |
4616 | block, DEPENDENCE_RELATIONS contains the relations between the data |
4617 | references. Compute read-read and self relations if | |
4618 | COMPUTE_SELF_AND_READ_READ_DEPENDENCES is TRUE. */ | |
4619 | bool | |
4620 | compute_data_dependences_for_bb (basic_block bb, | |
4621 | bool compute_self_and_read_read_dependences, | |
4622 | VEC (data_reference_p, heap) **datarefs, | |
4623 | VEC (ddr_p, heap) **dependence_relations) | |
4624 | { | |
4625 | if (find_data_references_in_bb (NULL, bb, datarefs) == chrec_dont_know) | |
4626 | return false; | |
4627 | ||
3881dee9 AB |
4628 | return compute_all_dependences (*datarefs, dependence_relations, NULL, |
4629 | compute_self_and_read_read_dependences); | |
a70d6342 IR |
4630 | } |
4631 | ||
56cf8686 | 4632 | /* Entry point (for testing only). Analyze all the data references |
3d8864c0 | 4633 | and the dependence relations in LOOP. |
56cf8686 | 4634 | |
b8698a0f L |
4635 | The data references are computed first. |
4636 | ||
56cf8686 SP |
4637 | A relation on these nodes is represented by a complete graph. Some |
4638 | of the relations could be of no interest, thus the relations can be | |
4639 | computed on demand. | |
b8698a0f | 4640 | |
56cf8686 SP |
4641 | In the following function we compute all the relations. This is |
4642 | just a first implementation that is here for: | |
b8698a0f | 4643 | - for showing how to ask for the dependence relations, |
56cf8686 SP |
4644 | - for the debugging the whole dependence graph, |
4645 | - for the dejagnu testcases and maintenance. | |
b8698a0f | 4646 | |
56cf8686 SP |
4647 | It is possible to ask only for a part of the graph, avoiding to |
4648 | compute the whole dependence graph. The computed dependences are | |
4649 | stored in a knowledge base (KB) such that later queries don't | |
4650 | recompute the same information. The implementation of this KB is | |
4651 | transparent to the optimizer, and thus the KB can be changed with a | |
4652 | more efficient implementation, or the KB could be disabled. */ | |
b8698a0f | 4653 | static void |
3d8864c0 | 4654 | analyze_all_data_dependences (struct loop *loop) |
56cf8686 SP |
4655 | { |
4656 | unsigned int i; | |
56cf8686 | 4657 | int nb_data_refs = 10; |
b8698a0f | 4658 | VEC (data_reference_p, heap) *datarefs = |
ebf78a47 | 4659 | VEC_alloc (data_reference_p, heap, nb_data_refs); |
b8698a0f | 4660 | VEC (ddr_p, heap) *dependence_relations = |
ebf78a47 | 4661 | VEC_alloc (ddr_p, heap, nb_data_refs * nb_data_refs); |
01be8516 | 4662 | VEC (loop_p, heap) *loop_nest = VEC_alloc (loop_p, heap, 3); |
56cf8686 SP |
4663 | |
4664 | /* Compute DDs on the whole function. */ | |
01be8516 | 4665 | compute_data_dependences_for_loop (loop, false, &loop_nest, &datarefs, |
3d8864c0 | 4666 | &dependence_relations); |
56cf8686 SP |
4667 | |
4668 | if (dump_file) | |
4669 | { | |
4670 | dump_data_dependence_relations (dump_file, dependence_relations); | |
4671 | fprintf (dump_file, "\n\n"); | |
56cf8686 | 4672 | |
86df10e3 SP |
4673 | if (dump_flags & TDF_DETAILS) |
4674 | dump_dist_dir_vectors (dump_file, dependence_relations); | |
56cf8686 | 4675 | |
86df10e3 | 4676 | if (dump_flags & TDF_STATS) |
56cf8686 | 4677 | { |
86df10e3 SP |
4678 | unsigned nb_top_relations = 0; |
4679 | unsigned nb_bot_relations = 0; | |
86df10e3 | 4680 | unsigned nb_chrec_relations = 0; |
ebf78a47 | 4681 | struct data_dependence_relation *ddr; |
86df10e3 | 4682 | |
ac47786e | 4683 | FOR_EACH_VEC_ELT (ddr_p, dependence_relations, i, ddr) |
86df10e3 | 4684 | { |
86df10e3 SP |
4685 | if (chrec_contains_undetermined (DDR_ARE_DEPENDENT (ddr))) |
4686 | nb_top_relations++; | |
b8698a0f | 4687 | |
86df10e3 | 4688 | else if (DDR_ARE_DEPENDENT (ddr) == chrec_known) |
5006671f | 4689 | nb_bot_relations++; |
b8698a0f L |
4690 | |
4691 | else | |
86df10e3 SP |
4692 | nb_chrec_relations++; |
4693 | } | |
b8698a0f | 4694 | |
86df10e3 SP |
4695 | gather_stats_on_scev_database (); |
4696 | } | |
56cf8686 | 4697 | } |
36d59cf7 | 4698 | |
01be8516 | 4699 | VEC_free (loop_p, heap, loop_nest); |
36d59cf7 DB |
4700 | free_dependence_relations (dependence_relations); |
4701 | free_data_refs (datarefs); | |
4702 | } | |
3d8864c0 SP |
4703 | |
4704 | /* Computes all the data dependences and check that the results of | |
4705 | several analyzers are the same. */ | |
4706 | ||
4707 | void | |
4708 | tree_check_data_deps (void) | |
4709 | { | |
4710 | loop_iterator li; | |
4711 | struct loop *loop_nest; | |
4712 | ||
4713 | FOR_EACH_LOOP (li, loop_nest, 0) | |
4714 | analyze_all_data_dependences (loop_nest); | |
4715 | } | |
36d59cf7 DB |
4716 | |
4717 | /* Free the memory used by a data dependence relation DDR. */ | |
4718 | ||
4719 | void | |
4720 | free_dependence_relation (struct data_dependence_relation *ddr) | |
4721 | { | |
4722 | if (ddr == NULL) | |
4723 | return; | |
4724 | ||
2f470326 | 4725 | if (DDR_SUBSCRIPTS (ddr)) |
d93817c4 | 4726 | free_subscripts (DDR_SUBSCRIPTS (ddr)); |
2f470326 JJ |
4727 | if (DDR_DIST_VECTS (ddr)) |
4728 | VEC_free (lambda_vector, heap, DDR_DIST_VECTS (ddr)); | |
4729 | if (DDR_DIR_VECTS (ddr)) | |
4730 | VEC_free (lambda_vector, heap, DDR_DIR_VECTS (ddr)); | |
ebf78a47 | 4731 | |
36d59cf7 DB |
4732 | free (ddr); |
4733 | } | |
4734 | ||
4735 | /* Free the memory used by the data dependence relations from | |
4736 | DEPENDENCE_RELATIONS. */ | |
4737 | ||
b8698a0f | 4738 | void |
ebf78a47 | 4739 | free_dependence_relations (VEC (ddr_p, heap) *dependence_relations) |
36d59cf7 DB |
4740 | { |
4741 | unsigned int i; | |
ebf78a47 | 4742 | struct data_dependence_relation *ddr; |
36d59cf7 | 4743 | |
ac47786e | 4744 | FOR_EACH_VEC_ELT (ddr_p, dependence_relations, i, ddr) |
01be8516 | 4745 | if (ddr) |
3ac57120 | 4746 | free_dependence_relation (ddr); |
ebf78a47 SP |
4747 | |
4748 | VEC_free (ddr_p, heap, dependence_relations); | |
56cf8686 SP |
4749 | } |
4750 | ||
36d59cf7 DB |
4751 | /* Free the memory used by the data references from DATAREFS. */ |
4752 | ||
4753 | void | |
ebf78a47 | 4754 | free_data_refs (VEC (data_reference_p, heap) *datarefs) |
36d59cf7 DB |
4755 | { |
4756 | unsigned int i; | |
ebf78a47 | 4757 | struct data_reference *dr; |
56cf8686 | 4758 | |
ac47786e | 4759 | FOR_EACH_VEC_ELT (data_reference_p, datarefs, i, dr) |
8fdbc9c6 | 4760 | free_data_ref (dr); |
ebf78a47 | 4761 | VEC_free (data_reference_p, heap, datarefs); |
36d59cf7 | 4762 | } |
86df10e3 | 4763 | |
3a796c6f SP |
4764 | \f |
4765 | ||
dea61d92 | 4766 | /* Dump vertex I in RDG to FILE. */ |
3a796c6f | 4767 | |
aeb83f09 | 4768 | static void |
dea61d92 SP |
4769 | dump_rdg_vertex (FILE *file, struct graph *rdg, int i) |
4770 | { | |
4771 | struct vertex *v = &(rdg->vertices[i]); | |
4772 | struct graph_edge *e; | |
4773 | ||
b8698a0f | 4774 | fprintf (file, "(vertex %d: (%s%s) (in:", i, |
dea61d92 SP |
4775 | RDG_MEM_WRITE_STMT (rdg, i) ? "w" : "", |
4776 | RDG_MEM_READS_STMT (rdg, i) ? "r" : ""); | |
4777 | ||
4778 | if (v->pred) | |
4779 | for (e = v->pred; e; e = e->pred_next) | |
4780 | fprintf (file, " %d", e->src); | |
4781 | ||
4782 | fprintf (file, ") (out:"); | |
4783 | ||
4784 | if (v->succ) | |
4785 | for (e = v->succ; e; e = e->succ_next) | |
4786 | fprintf (file, " %d", e->dest); | |
4787 | ||
cfee318d | 4788 | fprintf (file, ")\n"); |
726a989a | 4789 | print_gimple_stmt (file, RDGV_STMT (v), 0, TDF_VOPS|TDF_MEMSYMS); |
dea61d92 SP |
4790 | fprintf (file, ")\n"); |
4791 | } | |
4792 | ||
4793 | /* Call dump_rdg_vertex on stderr. */ | |
4794 | ||
24e47c76 | 4795 | DEBUG_FUNCTION void |
dea61d92 SP |
4796 | debug_rdg_vertex (struct graph *rdg, int i) |
4797 | { | |
4798 | dump_rdg_vertex (stderr, rdg, i); | |
4799 | } | |
4800 | ||
4801 | /* Dump component C of RDG to FILE. If DUMPED is non-null, set the | |
4802 | dumped vertices to that bitmap. */ | |
4803 | ||
aeb83f09 RG |
4804 | static void |
4805 | dump_rdg_component (FILE *file, struct graph *rdg, int c, bitmap dumped) | |
dea61d92 SP |
4806 | { |
4807 | int i; | |
4808 | ||
4809 | fprintf (file, "(%d\n", c); | |
4810 | ||
4811 | for (i = 0; i < rdg->n_vertices; i++) | |
4812 | if (rdg->vertices[i].component == c) | |
4813 | { | |
4814 | if (dumped) | |
4815 | bitmap_set_bit (dumped, i); | |
4816 | ||
4817 | dump_rdg_vertex (file, rdg, i); | |
4818 | } | |
4819 | ||
4820 | fprintf (file, ")\n"); | |
4821 | } | |
4822 | ||
4823 | /* Call dump_rdg_vertex on stderr. */ | |
4824 | ||
24e47c76 | 4825 | DEBUG_FUNCTION void |
dea61d92 SP |
4826 | debug_rdg_component (struct graph *rdg, int c) |
4827 | { | |
4828 | dump_rdg_component (stderr, rdg, c, NULL); | |
4829 | } | |
4830 | ||
4831 | /* Dump the reduced dependence graph RDG to FILE. */ | |
4832 | ||
4833 | void | |
4834 | dump_rdg (FILE *file, struct graph *rdg) | |
3a796c6f SP |
4835 | { |
4836 | int i; | |
dea61d92 SP |
4837 | bitmap dumped = BITMAP_ALLOC (NULL); |
4838 | ||
4839 | fprintf (file, "(rdg\n"); | |
3a796c6f SP |
4840 | |
4841 | for (i = 0; i < rdg->n_vertices; i++) | |
dea61d92 SP |
4842 | if (!bitmap_bit_p (dumped, i)) |
4843 | dump_rdg_component (file, rdg, rdg->vertices[i].component, dumped); | |
3a796c6f | 4844 | |
dea61d92 SP |
4845 | fprintf (file, ")\n"); |
4846 | BITMAP_FREE (dumped); | |
3a796c6f SP |
4847 | } |
4848 | ||
dea61d92 SP |
4849 | /* Call dump_rdg on stderr. */ |
4850 | ||
24e47c76 | 4851 | DEBUG_FUNCTION void |
dea61d92 SP |
4852 | debug_rdg (struct graph *rdg) |
4853 | { | |
4854 | dump_rdg (stderr, rdg); | |
4855 | } | |
3a796c6f | 4856 | |
f3241b29 SP |
4857 | static void |
4858 | dot_rdg_1 (FILE *file, struct graph *rdg) | |
4859 | { | |
4860 | int i; | |
4861 | ||
4862 | fprintf (file, "digraph RDG {\n"); | |
4863 | ||
4864 | for (i = 0; i < rdg->n_vertices; i++) | |
4865 | { | |
4866 | struct vertex *v = &(rdg->vertices[i]); | |
4867 | struct graph_edge *e; | |
4868 | ||
4869 | /* Highlight reads from memory. */ | |
4870 | if (RDG_MEM_READS_STMT (rdg, i)) | |
4871 | fprintf (file, "%d [style=filled, fillcolor=green]\n", i); | |
4872 | ||
4873 | /* Highlight stores to memory. */ | |
4874 | if (RDG_MEM_WRITE_STMT (rdg, i)) | |
4875 | fprintf (file, "%d [style=filled, fillcolor=red]\n", i); | |
4876 | ||
4877 | if (v->succ) | |
4878 | for (e = v->succ; e; e = e->succ_next) | |
4879 | switch (RDGE_TYPE (e)) | |
4880 | { | |
4881 | case input_dd: | |
4882 | fprintf (file, "%d -> %d [label=input] \n", i, e->dest); | |
4883 | break; | |
4884 | ||
4885 | case output_dd: | |
4886 | fprintf (file, "%d -> %d [label=output] \n", i, e->dest); | |
4887 | break; | |
4888 | ||
4889 | case flow_dd: | |
4890 | /* These are the most common dependences: don't print these. */ | |
4891 | fprintf (file, "%d -> %d \n", i, e->dest); | |
4892 | break; | |
4893 | ||
4894 | case anti_dd: | |
4895 | fprintf (file, "%d -> %d [label=anti] \n", i, e->dest); | |
4896 | break; | |
4897 | ||
4898 | default: | |
4899 | gcc_unreachable (); | |
4900 | } | |
4901 | } | |
4902 | ||
4903 | fprintf (file, "}\n\n"); | |
4904 | } | |
4905 | ||
4906 | /* Display the Reduced Dependence Graph using dotty. */ | |
4907 | extern void dot_rdg (struct graph *); | |
4908 | ||
4909 | DEBUG_FUNCTION void | |
4910 | dot_rdg (struct graph *rdg) | |
4911 | { | |
4912 | /* When debugging, enable the following code. This cannot be used | |
4913 | in production compilers because it calls "system". */ | |
4914 | #if 0 | |
4915 | FILE *file = fopen ("/tmp/rdg.dot", "w"); | |
4916 | gcc_assert (file != NULL); | |
4917 | ||
4918 | dot_rdg_1 (file, rdg); | |
4919 | fclose (file); | |
4920 | ||
4921 | system ("dotty /tmp/rdg.dot &"); | |
4922 | #else | |
4923 | dot_rdg_1 (stderr, rdg); | |
4924 | #endif | |
4925 | } | |
4926 | ||
dea61d92 SP |
4927 | /* This structure is used for recording the mapping statement index in |
4928 | the RDG. */ | |
4929 | ||
d1b38208 | 4930 | struct GTY(()) rdg_vertex_info |
dea61d92 | 4931 | { |
726a989a | 4932 | gimple stmt; |
dea61d92 SP |
4933 | int index; |
4934 | }; | |
4935 | ||
4936 | /* Returns the index of STMT in RDG. */ | |
4937 | ||
4938 | int | |
726a989a | 4939 | rdg_vertex_for_stmt (struct graph *rdg, gimple stmt) |
dea61d92 SP |
4940 | { |
4941 | struct rdg_vertex_info rvi, *slot; | |
4942 | ||
4943 | rvi.stmt = stmt; | |
4944 | slot = (struct rdg_vertex_info *) htab_find (rdg->indices, &rvi); | |
4945 | ||
4946 | if (!slot) | |
4947 | return -1; | |
4948 | ||
4949 | return slot->index; | |
4950 | } | |
4951 | ||
4952 | /* Creates an edge in RDG for each distance vector from DDR. The | |
4953 | order that we keep track of in the RDG is the order in which | |
4954 | statements have to be executed. */ | |
4955 | ||
4956 | static void | |
4957 | create_rdg_edge_for_ddr (struct graph *rdg, ddr_p ddr) | |
4958 | { | |
4959 | struct graph_edge *e; | |
4960 | int va, vb; | |
4961 | data_reference_p dra = DDR_A (ddr); | |
4962 | data_reference_p drb = DDR_B (ddr); | |
4963 | unsigned level = ddr_dependence_level (ddr); | |
4964 | ||
4965 | /* For non scalar dependences, when the dependence is REVERSED, | |
4966 | statement B has to be executed before statement A. */ | |
4967 | if (level > 0 | |
4968 | && !DDR_REVERSED_P (ddr)) | |
3a796c6f | 4969 | { |
dea61d92 SP |
4970 | data_reference_p tmp = dra; |
4971 | dra = drb; | |
4972 | drb = tmp; | |
3a796c6f SP |
4973 | } |
4974 | ||
dea61d92 SP |
4975 | va = rdg_vertex_for_stmt (rdg, DR_STMT (dra)); |
4976 | vb = rdg_vertex_for_stmt (rdg, DR_STMT (drb)); | |
4977 | ||
4978 | if (va < 0 || vb < 0) | |
4979 | return; | |
3a796c6f SP |
4980 | |
4981 | e = add_edge (rdg, va, vb); | |
4982 | e->data = XNEW (struct rdg_edge); | |
4983 | ||
dea61d92 | 4984 | RDGE_LEVEL (e) = level; |
f8bf9252 | 4985 | RDGE_RELATION (e) = ddr; |
dea61d92 | 4986 | |
3a796c6f SP |
4987 | /* Determines the type of the data dependence. */ |
4988 | if (DR_IS_READ (dra) && DR_IS_READ (drb)) | |
4989 | RDGE_TYPE (e) = input_dd; | |
b0af49c4 | 4990 | else if (DR_IS_WRITE (dra) && DR_IS_WRITE (drb)) |
3a796c6f | 4991 | RDGE_TYPE (e) = output_dd; |
b0af49c4 | 4992 | else if (DR_IS_WRITE (dra) && DR_IS_READ (drb)) |
3a796c6f | 4993 | RDGE_TYPE (e) = flow_dd; |
b0af49c4 | 4994 | else if (DR_IS_READ (dra) && DR_IS_WRITE (drb)) |
3a796c6f SP |
4995 | RDGE_TYPE (e) = anti_dd; |
4996 | } | |
4997 | ||
4998 | /* Creates dependence edges in RDG for all the uses of DEF. IDEF is | |
4999 | the index of DEF in RDG. */ | |
5000 | ||
5001 | static void | |
5002 | create_rdg_edges_for_scalar (struct graph *rdg, tree def, int idef) | |
5003 | { | |
5004 | use_operand_p imm_use_p; | |
5005 | imm_use_iterator iterator; | |
b8698a0f | 5006 | |
3a796c6f SP |
5007 | FOR_EACH_IMM_USE_FAST (imm_use_p, iterator, def) |
5008 | { | |
dea61d92 SP |
5009 | struct graph_edge *e; |
5010 | int use = rdg_vertex_for_stmt (rdg, USE_STMT (imm_use_p)); | |
3a796c6f | 5011 | |
dea61d92 SP |
5012 | if (use < 0) |
5013 | continue; | |
5014 | ||
5015 | e = add_edge (rdg, idef, use); | |
3a796c6f SP |
5016 | e->data = XNEW (struct rdg_edge); |
5017 | RDGE_TYPE (e) = flow_dd; | |
f8bf9252 | 5018 | RDGE_RELATION (e) = NULL; |
3a796c6f SP |
5019 | } |
5020 | } | |
5021 | ||
5022 | /* Creates the edges of the reduced dependence graph RDG. */ | |
5023 | ||
5024 | static void | |
5025 | create_rdg_edges (struct graph *rdg, VEC (ddr_p, heap) *ddrs) | |
5026 | { | |
5027 | int i; | |
5028 | struct data_dependence_relation *ddr; | |
5029 | def_operand_p def_p; | |
5030 | ssa_op_iter iter; | |
5031 | ||
ac47786e | 5032 | FOR_EACH_VEC_ELT (ddr_p, ddrs, i, ddr) |
3a796c6f SP |
5033 | if (DDR_ARE_DEPENDENT (ddr) == NULL_TREE) |
5034 | create_rdg_edge_for_ddr (rdg, ddr); | |
5035 | ||
5036 | for (i = 0; i < rdg->n_vertices; i++) | |
dea61d92 SP |
5037 | FOR_EACH_PHI_OR_STMT_DEF (def_p, RDG_STMT (rdg, i), |
5038 | iter, SSA_OP_DEF) | |
3a796c6f SP |
5039 | create_rdg_edges_for_scalar (rdg, DEF_FROM_PTR (def_p), i); |
5040 | } | |
5041 | ||
5042 | /* Build the vertices of the reduced dependence graph RDG. */ | |
5043 | ||
f8bf9252 | 5044 | void |
726a989a | 5045 | create_rdg_vertices (struct graph *rdg, VEC (gimple, heap) *stmts) |
3a796c6f | 5046 | { |
dea61d92 | 5047 | int i, j; |
726a989a | 5048 | gimple stmt; |
3a796c6f | 5049 | |
ac47786e | 5050 | FOR_EACH_VEC_ELT (gimple, stmts, i, stmt) |
3a796c6f | 5051 | { |
dea61d92 SP |
5052 | VEC (data_ref_loc, heap) *references; |
5053 | data_ref_loc *ref; | |
3a796c6f | 5054 | struct vertex *v = &(rdg->vertices[i]); |
dea61d92 SP |
5055 | struct rdg_vertex_info *rvi = XNEW (struct rdg_vertex_info); |
5056 | struct rdg_vertex_info **slot; | |
5057 | ||
5058 | rvi->stmt = stmt; | |
5059 | rvi->index = i; | |
5060 | slot = (struct rdg_vertex_info **) htab_find_slot (rdg->indices, rvi, INSERT); | |
5061 | ||
5062 | if (!*slot) | |
5063 | *slot = rvi; | |
5064 | else | |
5065 | free (rvi); | |
3a796c6f SP |
5066 | |
5067 | v->data = XNEW (struct rdg_vertex); | |
dea61d92 SP |
5068 | RDG_STMT (rdg, i) = stmt; |
5069 | ||
5070 | RDG_MEM_WRITE_STMT (rdg, i) = false; | |
5071 | RDG_MEM_READS_STMT (rdg, i) = false; | |
726a989a | 5072 | if (gimple_code (stmt) == GIMPLE_PHI) |
dea61d92 SP |
5073 | continue; |
5074 | ||
5075 | get_references_in_stmt (stmt, &references); | |
ac47786e | 5076 | FOR_EACH_VEC_ELT (data_ref_loc, references, j, ref) |
dea61d92 SP |
5077 | if (!ref->is_read) |
5078 | RDG_MEM_WRITE_STMT (rdg, i) = true; | |
5079 | else | |
5080 | RDG_MEM_READS_STMT (rdg, i) = true; | |
5081 | ||
5082 | VEC_free (data_ref_loc, heap, references); | |
3a796c6f SP |
5083 | } |
5084 | } | |
5085 | ||
dea61d92 SP |
5086 | /* Initialize STMTS with all the statements of LOOP. When |
5087 | INCLUDE_PHIS is true, include also the PHI nodes. The order in | |
5088 | which we discover statements is important as | |
5089 | generate_loops_for_partition is using the same traversal for | |
5090 | identifying statements. */ | |
3a796c6f SP |
5091 | |
5092 | static void | |
726a989a | 5093 | stmts_from_loop (struct loop *loop, VEC (gimple, heap) **stmts) |
3a796c6f SP |
5094 | { |
5095 | unsigned int i; | |
5096 | basic_block *bbs = get_loop_body_in_dom_order (loop); | |
5097 | ||
5098 | for (i = 0; i < loop->num_nodes; i++) | |
5099 | { | |
3a796c6f | 5100 | basic_block bb = bbs[i]; |
726a989a RB |
5101 | gimple_stmt_iterator bsi; |
5102 | gimple stmt; | |
3a796c6f | 5103 | |
726a989a RB |
5104 | for (bsi = gsi_start_phis (bb); !gsi_end_p (bsi); gsi_next (&bsi)) |
5105 | VEC_safe_push (gimple, heap, *stmts, gsi_stmt (bsi)); | |
3a796c6f | 5106 | |
726a989a RB |
5107 | for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi)) |
5108 | { | |
5109 | stmt = gsi_stmt (bsi); | |
b03c3082 | 5110 | if (gimple_code (stmt) != GIMPLE_LABEL && !is_gimple_debug (stmt)) |
726a989a RB |
5111 | VEC_safe_push (gimple, heap, *stmts, stmt); |
5112 | } | |
3a796c6f SP |
5113 | } |
5114 | ||
5115 | free (bbs); | |
5116 | } | |
5117 | ||
5118 | /* Returns true when all the dependences are computable. */ | |
5119 | ||
5120 | static bool | |
5121 | known_dependences_p (VEC (ddr_p, heap) *dependence_relations) | |
5122 | { | |
5123 | ddr_p ddr; | |
5124 | unsigned int i; | |
5125 | ||
ac47786e | 5126 | FOR_EACH_VEC_ELT (ddr_p, dependence_relations, i, ddr) |
3a796c6f SP |
5127 | if (DDR_ARE_DEPENDENT (ddr) == chrec_dont_know) |
5128 | return false; | |
b8698a0f | 5129 | |
3a796c6f SP |
5130 | return true; |
5131 | } | |
5132 | ||
dea61d92 SP |
5133 | /* Computes a hash function for element ELT. */ |
5134 | ||
5135 | static hashval_t | |
5136 | hash_stmt_vertex_info (const void *elt) | |
5137 | { | |
1634b18f KG |
5138 | const struct rdg_vertex_info *const rvi = |
5139 | (const struct rdg_vertex_info *) elt; | |
726a989a | 5140 | gimple stmt = rvi->stmt; |
dea61d92 SP |
5141 | |
5142 | return htab_hash_pointer (stmt); | |
5143 | } | |
5144 | ||
5145 | /* Compares database elements E1 and E2. */ | |
5146 | ||
5147 | static int | |
5148 | eq_stmt_vertex_info (const void *e1, const void *e2) | |
5149 | { | |
5150 | const struct rdg_vertex_info *elt1 = (const struct rdg_vertex_info *) e1; | |
5151 | const struct rdg_vertex_info *elt2 = (const struct rdg_vertex_info *) e2; | |
5152 | ||
5153 | return elt1->stmt == elt2->stmt; | |
5154 | } | |
5155 | ||
5156 | /* Free the element E. */ | |
5157 | ||
5158 | static void | |
5159 | hash_stmt_vertex_del (void *e) | |
5160 | { | |
5161 | free (e); | |
5162 | } | |
5163 | ||
f8bf9252 SP |
5164 | /* Build the Reduced Dependence Graph (RDG) with one vertex per |
5165 | statement of the loop nest, and one edge per data dependence or | |
5166 | scalar dependence. */ | |
5167 | ||
5168 | struct graph * | |
5169 | build_empty_rdg (int n_stmts) | |
5170 | { | |
5171 | int nb_data_refs = 10; | |
5172 | struct graph *rdg = new_graph (n_stmts); | |
5173 | ||
5174 | rdg->indices = htab_create (nb_data_refs, hash_stmt_vertex_info, | |
5175 | eq_stmt_vertex_info, hash_stmt_vertex_del); | |
5176 | return rdg; | |
5177 | } | |
5178 | ||
dea61d92 SP |
5179 | /* Build the Reduced Dependence Graph (RDG) with one vertex per |
5180 | statement of the loop nest, and one edge per data dependence or | |
5181 | scalar dependence. */ | |
3a796c6f SP |
5182 | |
5183 | struct graph * | |
01be8516 SP |
5184 | build_rdg (struct loop *loop, |
5185 | VEC (loop_p, heap) **loop_nest, | |
5186 | VEC (ddr_p, heap) **dependence_relations, | |
5187 | VEC (data_reference_p, heap) **datarefs) | |
3a796c6f | 5188 | { |
3a796c6f | 5189 | struct graph *rdg = NULL; |
3a796c6f | 5190 | |
8a1da634 JJ |
5191 | if (compute_data_dependences_for_loop (loop, false, loop_nest, datarefs, |
5192 | dependence_relations) | |
5193 | && known_dependences_p (*dependence_relations)) | |
01be8516 | 5194 | { |
8a1da634 | 5195 | VEC (gimple, heap) *stmts = VEC_alloc (gimple, heap, 10); |
01be8516 SP |
5196 | stmts_from_loop (loop, &stmts); |
5197 | rdg = build_empty_rdg (VEC_length (gimple, stmts)); | |
5198 | create_rdg_vertices (rdg, stmts); | |
5199 | create_rdg_edges (rdg, *dependence_relations); | |
8a1da634 | 5200 | VEC_free (gimple, heap, stmts); |
01be8516 | 5201 | } |
3a796c6f | 5202 | |
3a796c6f SP |
5203 | return rdg; |
5204 | } | |
dea61d92 SP |
5205 | |
5206 | /* Free the reduced dependence graph RDG. */ | |
5207 | ||
5208 | void | |
5209 | free_rdg (struct graph *rdg) | |
5210 | { | |
5211 | int i; | |
5212 | ||
5213 | for (i = 0; i < rdg->n_vertices; i++) | |
01be8516 SP |
5214 | { |
5215 | struct vertex *v = &(rdg->vertices[i]); | |
5216 | struct graph_edge *e; | |
5217 | ||
5218 | for (e = v->succ; e; e = e->succ_next) | |
04695783 | 5219 | free (e->data); |
01be8516 | 5220 | |
04695783 | 5221 | free (v->data); |
01be8516 | 5222 | } |
dea61d92 SP |
5223 | |
5224 | htab_delete (rdg->indices); | |
5225 | free_graph (rdg); | |
5226 | } | |
5227 | ||
5228 | /* Initialize STMTS with all the statements of LOOP that contain a | |
5229 | store to memory. */ | |
5230 | ||
5231 | void | |
726a989a | 5232 | stores_from_loop (struct loop *loop, VEC (gimple, heap) **stmts) |
dea61d92 SP |
5233 | { |
5234 | unsigned int i; | |
5235 | basic_block *bbs = get_loop_body_in_dom_order (loop); | |
5236 | ||
5237 | for (i = 0; i < loop->num_nodes; i++) | |
5238 | { | |
5239 | basic_block bb = bbs[i]; | |
726a989a | 5240 | gimple_stmt_iterator bsi; |
dea61d92 | 5241 | |
726a989a | 5242 | for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi)) |
5006671f | 5243 | if (gimple_vdef (gsi_stmt (bsi))) |
726a989a | 5244 | VEC_safe_push (gimple, heap, *stmts, gsi_stmt (bsi)); |
dea61d92 SP |
5245 | } |
5246 | ||
5247 | free (bbs); | |
5248 | } | |
5249 | ||
cfee318d SP |
5250 | /* Returns true when the statement at STMT is of the form "A[i] = 0" |
5251 | that contains a data reference on its LHS with a stride of the same | |
5252 | size as its unit type. */ | |
5e37ea0e | 5253 | |
cfee318d SP |
5254 | bool |
5255 | stmt_with_adjacent_zero_store_dr_p (gimple stmt) | |
5e37ea0e | 5256 | { |
cfee318d | 5257 | tree op0, op1; |
5e37ea0e | 5258 | bool res; |
cfee318d SP |
5259 | struct data_reference *dr; |
5260 | ||
5261 | if (!stmt | |
5262 | || !gimple_vdef (stmt) | |
5263 | || !is_gimple_assign (stmt) | |
5264 | || !gimple_assign_single_p (stmt) | |
5265 | || !(op1 = gimple_assign_rhs1 (stmt)) | |
5266 | || !(integer_zerop (op1) || real_zerop (op1))) | |
5267 | return false; | |
5268 | ||
5269 | dr = XCNEW (struct data_reference); | |
5270 | op0 = gimple_assign_lhs (stmt); | |
5e37ea0e SP |
5271 | |
5272 | DR_STMT (dr) = stmt; | |
5273 | DR_REF (dr) = op0; | |
5274 | ||
4e4452b6 | 5275 | res = dr_analyze_innermost (dr, loop_containing_stmt (stmt)) |
5e37ea0e SP |
5276 | && stride_of_unit_type_p (DR_STEP (dr), TREE_TYPE (op0)); |
5277 | ||
5278 | free_data_ref (dr); | |
5279 | return res; | |
5280 | } | |
5281 | ||
20769d5e SP |
5282 | /* Initialize STMTS with all the statements of LOOP that contain a |
5283 | store to memory of the form "A[i] = 0". */ | |
5284 | ||
5285 | void | |
5286 | stores_zero_from_loop (struct loop *loop, VEC (gimple, heap) **stmts) | |
5287 | { | |
5288 | unsigned int i; | |
5289 | basic_block bb; | |
5290 | gimple_stmt_iterator si; | |
5291 | gimple stmt; | |
20769d5e SP |
5292 | basic_block *bbs = get_loop_body_in_dom_order (loop); |
5293 | ||
5294 | for (i = 0; i < loop->num_nodes; i++) | |
5295 | for (bb = bbs[i], si = gsi_start_bb (bb); !gsi_end_p (si); gsi_next (&si)) | |
5296 | if ((stmt = gsi_stmt (si)) | |
cfee318d | 5297 | && stmt_with_adjacent_zero_store_dr_p (stmt)) |
20769d5e SP |
5298 | VEC_safe_push (gimple, heap, *stmts, gsi_stmt (si)); |
5299 | ||
5300 | free (bbs); | |
5301 | } | |
5302 | ||
dea61d92 SP |
5303 | /* For a data reference REF, return the declaration of its base |
5304 | address or NULL_TREE if the base is not determined. */ | |
5305 | ||
5306 | static inline tree | |
726a989a | 5307 | ref_base_address (gimple stmt, data_ref_loc *ref) |
dea61d92 SP |
5308 | { |
5309 | tree base = NULL_TREE; | |
5310 | tree base_address; | |
5311 | struct data_reference *dr = XCNEW (struct data_reference); | |
5312 | ||
5313 | DR_STMT (dr) = stmt; | |
5314 | DR_REF (dr) = *ref->pos; | |
4e4452b6 | 5315 | dr_analyze_innermost (dr, loop_containing_stmt (stmt)); |
dea61d92 SP |
5316 | base_address = DR_BASE_ADDRESS (dr); |
5317 | ||
5318 | if (!base_address) | |
5319 | goto end; | |
5320 | ||
5321 | switch (TREE_CODE (base_address)) | |
5322 | { | |
5323 | case ADDR_EXPR: | |
5324 | base = TREE_OPERAND (base_address, 0); | |
5325 | break; | |
5326 | ||
5327 | default: | |
5328 | base = base_address; | |
5329 | break; | |
5330 | } | |
5331 | ||
5332 | end: | |
5333 | free_data_ref (dr); | |
5334 | return base; | |
5335 | } | |
5336 | ||
5337 | /* Determines whether the statement from vertex V of the RDG has a | |
5338 | definition used outside the loop that contains this statement. */ | |
5339 | ||
5340 | bool | |
5341 | rdg_defs_used_in_other_loops_p (struct graph *rdg, int v) | |
5342 | { | |
726a989a | 5343 | gimple stmt = RDG_STMT (rdg, v); |
dea61d92 SP |
5344 | struct loop *loop = loop_containing_stmt (stmt); |
5345 | use_operand_p imm_use_p; | |
5346 | imm_use_iterator iterator; | |
5347 | ssa_op_iter it; | |
5348 | def_operand_p def_p; | |
5349 | ||
5350 | if (!loop) | |
5351 | return true; | |
5352 | ||
5353 | FOR_EACH_PHI_OR_STMT_DEF (def_p, stmt, it, SSA_OP_DEF) | |
5354 | { | |
5355 | FOR_EACH_IMM_USE_FAST (imm_use_p, iterator, DEF_FROM_PTR (def_p)) | |
5356 | { | |
5357 | if (loop_containing_stmt (USE_STMT (imm_use_p)) != loop) | |
5358 | return true; | |
5359 | } | |
5360 | } | |
5361 | ||
5362 | return false; | |
5363 | } | |
5364 | ||
5365 | /* Determines whether statements S1 and S2 access to similar memory | |
5366 | locations. Two memory accesses are considered similar when they | |
5367 | have the same base address declaration, i.e. when their | |
5368 | ref_base_address is the same. */ | |
5369 | ||
5370 | bool | |
726a989a | 5371 | have_similar_memory_accesses (gimple s1, gimple s2) |
dea61d92 SP |
5372 | { |
5373 | bool res = false; | |
5374 | unsigned i, j; | |
5375 | VEC (data_ref_loc, heap) *refs1, *refs2; | |
5376 | data_ref_loc *ref1, *ref2; | |
5377 | ||
5378 | get_references_in_stmt (s1, &refs1); | |
5379 | get_references_in_stmt (s2, &refs2); | |
5380 | ||
ac47786e | 5381 | FOR_EACH_VEC_ELT (data_ref_loc, refs1, i, ref1) |
dea61d92 SP |
5382 | { |
5383 | tree base1 = ref_base_address (s1, ref1); | |
5384 | ||
5385 | if (base1) | |
ac47786e | 5386 | FOR_EACH_VEC_ELT (data_ref_loc, refs2, j, ref2) |
dea61d92 SP |
5387 | if (base1 == ref_base_address (s2, ref2)) |
5388 | { | |
5389 | res = true; | |
5390 | goto end; | |
5391 | } | |
5392 | } | |
5393 | ||
5394 | end: | |
5395 | VEC_free (data_ref_loc, heap, refs1); | |
5396 | VEC_free (data_ref_loc, heap, refs2); | |
5397 | return res; | |
5398 | } | |
5399 | ||
5400 | /* Helper function for the hashtab. */ | |
5401 | ||
5402 | static int | |
5403 | have_similar_memory_accesses_1 (const void *s1, const void *s2) | |
5404 | { | |
726a989a RB |
5405 | return have_similar_memory_accesses (CONST_CAST_GIMPLE ((const_gimple) s1), |
5406 | CONST_CAST_GIMPLE ((const_gimple) s2)); | |
dea61d92 SP |
5407 | } |
5408 | ||
5409 | /* Helper function for the hashtab. */ | |
5410 | ||
5411 | static hashval_t | |
5412 | ref_base_address_1 (const void *s) | |
5413 | { | |
726a989a | 5414 | gimple stmt = CONST_CAST_GIMPLE ((const_gimple) s); |
dea61d92 SP |
5415 | unsigned i; |
5416 | VEC (data_ref_loc, heap) *refs; | |
5417 | data_ref_loc *ref; | |
5418 | hashval_t res = 0; | |
5419 | ||
5420 | get_references_in_stmt (stmt, &refs); | |
5421 | ||
ac47786e | 5422 | FOR_EACH_VEC_ELT (data_ref_loc, refs, i, ref) |
dea61d92 SP |
5423 | if (!ref->is_read) |
5424 | { | |
5425 | res = htab_hash_pointer (ref_base_address (stmt, ref)); | |
5426 | break; | |
5427 | } | |
5428 | ||
5429 | VEC_free (data_ref_loc, heap, refs); | |
5430 | return res; | |
5431 | } | |
5432 | ||
5433 | /* Try to remove duplicated write data references from STMTS. */ | |
5434 | ||
5435 | void | |
726a989a | 5436 | remove_similar_memory_refs (VEC (gimple, heap) **stmts) |
dea61d92 SP |
5437 | { |
5438 | unsigned i; | |
726a989a RB |
5439 | gimple stmt; |
5440 | htab_t seen = htab_create (VEC_length (gimple, *stmts), ref_base_address_1, | |
dea61d92 SP |
5441 | have_similar_memory_accesses_1, NULL); |
5442 | ||
726a989a | 5443 | for (i = 0; VEC_iterate (gimple, *stmts, i, stmt); ) |
dea61d92 SP |
5444 | { |
5445 | void **slot; | |
5446 | ||
5447 | slot = htab_find_slot (seen, stmt, INSERT); | |
5448 | ||
5449 | if (*slot) | |
726a989a | 5450 | VEC_ordered_remove (gimple, *stmts, i); |
dea61d92 SP |
5451 | else |
5452 | { | |
5453 | *slot = (void *) stmt; | |
5454 | i++; | |
5455 | } | |
5456 | } | |
5457 | ||
5458 | htab_delete (seen); | |
5459 | } | |
5460 |