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5f40b3cb ZD |
1 | /* Loop autoparallelization. |
2 | Copyright (C) 2006 Free Software Foundation, Inc. | |
3 | Contributed by Sebastian Pop <pop@cri.ensmp.fr> and | |
4 | Zdenek Dvorak <dvorakz@suse.cz>. | |
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 | |
10 | Software Foundation; either version 2, or (at your option) any later | |
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 | |
19 | along with GCC; see the file COPYING. If not, write to the Free | |
20 | Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA | |
21 | 02110-1301, USA. */ | |
22 | ||
23 | #include "config.h" | |
24 | #include "system.h" | |
25 | #include "coretypes.h" | |
26 | #include "tm.h" | |
27 | #include "tree.h" | |
28 | #include "rtl.h" | |
29 | #include "tree-flow.h" | |
30 | #include "cfgloop.h" | |
31 | #include "ggc.h" | |
32 | #include "tree-data-ref.h" | |
33 | #include "diagnostic.h" | |
34 | #include "tree-pass.h" | |
35 | #include "tree-scalar-evolution.h" | |
36 | #include "hashtab.h" | |
37 | #include "langhooks.h" | |
a509ebb5 | 38 | #include "tree-vectorizer.h" |
5f40b3cb ZD |
39 | |
40 | /* This pass tries to distribute iterations of loops into several threads. | |
41 | The implementation is straightforward -- for each loop we test whether its | |
42 | iterations are independent, and if it is the case (and some additional | |
43 | conditions regarding profitability and correctness are satisfied), we | |
44 | add OMP_PARALLEL and OMP_FOR codes and let omp expansion machinery do | |
45 | its job. | |
46 | ||
47 | The most of the complexity is in bringing the code into shape expected | |
48 | by the omp expanders: | |
49 | -- for OMP_FOR, ensuring that the loop has only one induction variable | |
50 | and that the exit test is at the start of the loop body | |
51 | -- for OMP_PARALLEL, replacing the references to local addressable | |
52 | variables by accesses through pointers, and breaking up ssa chains | |
53 | by storing the values incoming to the parallelized loop to a structure | |
54 | passed to the new function as an argument (something similar is done | |
55 | in omp gimplification, unfortunately only a small part of the code | |
56 | can be shared). | |
57 | ||
58 | TODO: | |
59 | -- if there are several parallelizable loops in a function, it may be | |
60 | possible to generate the threads just once (using synchronization to | |
61 | ensure that cross-loop dependences are obeyed). | |
62 | -- handling of common scalar dependence patterns (accumulation, ...) | |
63 | -- handling of non-innermost loops */ | |
64 | ||
a509ebb5 RL |
65 | /* |
66 | Reduction handling: | |
67 | currently we use vect_is_simple_reduction() to detect reduction patterns. | |
68 | The code transformation will be introduced by an example. | |
69 | ||
70 | source code: | |
71 | ||
72 | parloop | |
73 | { | |
74 | int sum=1; | |
75 | ||
76 | for (i = 0; i < N/1000; i++) | |
77 | { | |
78 | x[i] = i + 3; | |
79 | sum+=x[i]; | |
80 | } | |
81 | } | |
82 | ||
83 | gimple code: | |
84 | ||
85 | header_bb: | |
86 | ||
87 | # sum_24 = PHI <sum_14(3), 1(2)>; | |
88 | # i_21 = PHI <i_15(3), 0(2)>; | |
89 | <L0>:; | |
90 | D.2191_10 = i_21 + 3; | |
91 | x[i_21] = D.2191_10; | |
92 | sum_14 = D.2191_10 + sum_24; | |
93 | i_15 = i_21 + 1; | |
94 | if (N_8 > i_15) goto <L0>; else goto <L2>; | |
95 | ||
96 | exit_bb: | |
97 | ||
98 | # sum_25 = PHI <sum_14(3)>; | |
99 | <L2>:; | |
100 | ||
101 | ||
102 | after reduction transformation (only relevant parts): | |
103 | ||
104 | parloop | |
105 | { | |
106 | ||
107 | .... | |
108 | ||
109 | <L16>:; | |
110 | D.2241_2 = (unsigned int) N_8; | |
111 | D.2242_26 = D.2241_2 - 1; | |
112 | if (D.2242_26 > 399) goto <L26>; else goto <L27>; | |
113 | ||
114 | #two new variables are created for each reduction: | |
115 | "reduction" is the variable holding the neutral element | |
116 | for the particular operation, e.g. 0 for PLUS_EXPR, | |
117 | 1 for MULT_EXPR, etc. | |
118 | "reduction_initial" is the initial value given by the user. | |
119 | It is kept and will be used after the parallel computing | |
120 | is done.# | |
121 | ||
122 | <L26>:; | |
123 | reduction.38_42 = 0; | |
124 | reduction_initial.39_43 = 1; | |
125 | x.40_44 = &x; | |
126 | .paral_data_store.47.D.2261 = D.2242_26; | |
127 | .paral_data_store.47.reduction.38 = reduction.38_42; | |
128 | .paral_data_store.47.x.40 = x.40_44; | |
129 | __builtin_GOMP_parallel_start (parloop._loopfn.0, &.paral_data_store.47, 4); | |
130 | parloop._loopfn.0 (&.paral_data_store.47); | |
131 | __builtin_GOMP_parallel_end (); | |
132 | ||
133 | # collecting the result after the join of the threads is done at | |
134 | create_loads_for_reductions(). | |
135 | a new variable "reduction_final" is created. It calculates the | |
136 | final value from the initial value and the value computed by | |
137 | the threads. # | |
138 | ||
139 | .paral_data_load.48_49 = &.paral_data_store.47; | |
140 | reduction_final.49_50 = .paral_data_load.48_49->reduction.38; | |
141 | reduction_final.49_51 = reduction_initial.39_43 + reduction_final.49_50; | |
142 | ivtmp.37_36 = D.2242_26; | |
143 | i_37 = (int) ivtmp.37_36; | |
144 | D.2191_38 = i_37 + 3; | |
145 | x[i_37] = D.2191_38; | |
146 | sum_40 = D.2191_38 + reduction_final.49_51; | |
147 | i_41 = i_37 + 1; | |
148 | goto <bb 8> (<L2>); | |
149 | ||
150 | # sum_25 = PHI <sum_40(4), sum_9(6)>; | |
151 | <L2>:; | |
152 | printf (&"sum is %d\n"[0], sum_25); | |
153 | ||
154 | ... | |
155 | ||
156 | } | |
157 | ||
158 | parloop._loopfn.0 (.paral_data_param) | |
159 | { | |
160 | ... | |
161 | ||
162 | <L28>:; | |
163 | .paral_data_param_52 = .paral_data_param_75; | |
164 | .paral_data_load.48_48 = (struct .paral_data.46 *) .paral_data_param_52; | |
165 | D.2289_46 = .paral_data_load.48_48->D.2261; | |
166 | reduction.43_45 = .paral_data_load.48_48->reduction.38; | |
167 | x.45_47 = .paral_data_load.48_48->x.40; | |
168 | # SUCC: 23 [100.0%] (fallthru) | |
169 | ||
170 | # BLOCK 23 | |
171 | # PRED: 21 [100.0%] (fallthru) | |
172 | <L30>:; | |
173 | D.2292_60 = __builtin_omp_get_num_threads (); | |
174 | D.2293_61 = (unsigned int) D.2292_60; | |
175 | D.2294_62 = __builtin_omp_get_thread_num (); | |
176 | D.2295_63 = (unsigned int) D.2294_62; | |
177 | D.2296_64 = D.2289_46 / D.2293_61; | |
178 | D.2297_65 = D.2293_61 * D.2296_64; | |
179 | D.2298_66 = D.2297_65 != D.2289_46; | |
180 | D.2299_67 = D.2296_64 + D.2298_66; | |
181 | D.2300_68 = D.2299_67 * D.2295_63; | |
182 | D.2301_69 = D.2299_67 + D.2300_68; | |
183 | D.2302_70 = MIN_EXPR <D.2301_69, D.2289_46>; | |
184 | ivtmp.41_54 = D.2300_68; | |
185 | if (D.2300_68 >= D.2302_70) goto <L31>; else goto <L32>; | |
186 | # SUCC: 26 [100.0%] (false) 24 (true) | |
187 | ||
188 | # BLOCK 26 | |
189 | # PRED: 23 [100.0%] (false) | |
190 | <L32>:; | |
191 | # SUCC: 4 [100.0%] (fallthru) | |
192 | ||
193 | # BLOCK 4 | |
194 | # PRED: 5 [100.0%] (true) 26 [100.0%] (fallthru) | |
195 | # ivtmp.41_31 = PHI <ivtmp.41_30(5), ivtmp.41_54(26)>; | |
196 | # sum.42_32 = PHI <sum.42_14(5), reduction.43_45(26)>; | |
197 | <L0>:; | |
198 | # SUCC: 19 [100.0%] (fallthru) | |
199 | ||
200 | # BLOCK 19 | |
201 | # PRED: 4 [100.0%] (fallthru) | |
202 | # sum.42_24 = PHI <sum.42_32(4)>; | |
203 | # ivtmp.41_17 = PHI <ivtmp.41_31(4)>; | |
204 | i.44_21 = (int) ivtmp.41_17; | |
205 | D.2310_10 = i.44_21 + 3; | |
206 | (*x.45_47)[i.44_21] = D.2310_10; | |
207 | sum.42_14 = D.2310_10 + sum.42_24; | |
208 | i.44_15 = i.44_21 + 1; | |
209 | # SUCC: 5 [100.0%] (fallthru) | |
210 | ||
211 | # BLOCK 5 | |
212 | # PRED: 19 [100.0%] (fallthru) | |
213 | <L17>:; | |
214 | ivtmp.41_30 = ivtmp.41_31 + 1; | |
215 | if (ivtmp.41_30 < D.2302_70) goto <L0>; else goto <L31>; | |
216 | # SUCC: 4 [100.0%] (true) 24 (false) | |
217 | ||
218 | # Adding this reduction phi is done at | |
219 | create_phi_for_local_result() # | |
220 | ||
221 | # BLOCK 24 | |
222 | # PRED: 5 (false) 23 (true) | |
223 | # reduction.38_56 = PHI <sum.42_14(5), 0(23)>; | |
224 | <L31>:; | |
225 | __builtin_GOMP_barrier (); | |
226 | # SUCC: 25 [100.0%] (fallthru) | |
227 | ||
228 | # Creating the atomic operation is | |
229 | done at create_call_for_reduction_1() # | |
230 | ||
231 | # BLOCK 25 | |
232 | # PRED: 24 [100.0%] (fallthru) | |
233 | D.2306_57 = &.paral_data_load.48_48->reduction.38; | |
234 | D.2307_58 = (unsigned int) reduction.38_56; | |
235 | D.2308_59 = __sync_fetch_and_add_4 (D.2306_57, D.2307_58); | |
236 | # SUCC: 22 [100.0%] (fallthru) | |
237 | ||
238 | # BLOCK 22 | |
239 | # PRED: 25 [100.0%] (fallthru) | |
240 | <L29>:; | |
241 | return; | |
242 | # SUCC: EXIT | |
243 | ||
244 | } | |
245 | ||
246 | */ | |
247 | ||
5f40b3cb ZD |
248 | /* Minimal number of iterations of a loop that should be executed in each |
249 | thread. */ | |
250 | #define MIN_PER_THREAD 100 | |
251 | ||
a509ebb5 RL |
252 | /* Element of the hashtable, representing a |
253 | reduction in the current loop. */ | |
254 | struct reduction_info | |
255 | { | |
256 | tree reduc_stmt; /* reduction statement. */ | |
257 | tree reduc_phi; /* The phi node defining the reduction. */ | |
258 | enum tree_code reduction_code; /* code for the reduction operation. */ | |
259 | tree keep_res; /* The PHI_RESULT of this phi is the resulting value | |
260 | of the reduction variable when existing the loop. */ | |
261 | tree initial_value; /* An ssa name representing a new variable holding | |
262 | the initial value of the reduction var before entering the loop. */ | |
263 | tree field; /* the name of the field in the parloop data structure intended for reduction. */ | |
264 | tree reduction_init; /* An ssa name representing a new variable which will be | |
265 | assigned the proper reduction initialization value (init). */ | |
266 | tree init; /* reduction initialization value. */ | |
267 | tree new_phi; /* (helper field) Newly created phi node whose result | |
268 | will be passed to the atomic operation. Represents | |
269 | the local result each thread computed for the reduction | |
270 | operation. */ | |
271 | }; | |
272 | ||
273 | /* Equality and hash functions for hashtab code. */ | |
274 | ||
275 | static int | |
276 | reduction_info_eq (const void *aa, const void *bb) | |
277 | { | |
278 | const struct reduction_info *a = (const struct reduction_info *) aa; | |
279 | const struct reduction_info *b = (const struct reduction_info *) bb; | |
280 | ||
281 | return (a->reduc_phi == b->reduc_phi); | |
282 | } | |
283 | ||
284 | static hashval_t | |
285 | reduction_info_hash (const void *aa) | |
286 | { | |
287 | const struct reduction_info *a = (const struct reduction_info *) aa; | |
288 | ||
289 | return htab_hash_pointer (a->reduc_phi); | |
290 | } | |
291 | ||
292 | static struct reduction_info * | |
293 | reduction_phi (htab_t reduction_list, tree phi) | |
294 | { | |
295 | struct reduction_info tmpred, *red; | |
296 | ||
297 | if (htab_elements (reduction_list) == 0) | |
298 | return NULL; | |
299 | ||
300 | tmpred.reduc_phi = phi; | |
301 | red = htab_find (reduction_list, &tmpred); | |
302 | ||
303 | return red; | |
304 | } | |
305 | ||
5f40b3cb ZD |
306 | /* Element of hashtable of names to copy. */ |
307 | ||
308 | struct name_to_copy_elt | |
309 | { | |
310 | unsigned version; /* The version of the name to copy. */ | |
311 | tree new_name; /* The new name used in the copy. */ | |
312 | tree field; /* The field of the structure used to pass the | |
313 | value. */ | |
314 | }; | |
315 | ||
316 | /* Equality and hash functions for hashtab code. */ | |
317 | ||
318 | static int | |
319 | name_to_copy_elt_eq (const void *aa, const void *bb) | |
320 | { | |
a509ebb5 RL |
321 | const struct name_to_copy_elt *a = (const struct name_to_copy_elt *) aa; |
322 | const struct name_to_copy_elt *b = (const struct name_to_copy_elt *) bb; | |
5f40b3cb ZD |
323 | |
324 | return a->version == b->version; | |
325 | } | |
326 | ||
327 | static hashval_t | |
328 | name_to_copy_elt_hash (const void *aa) | |
329 | { | |
a509ebb5 | 330 | const struct name_to_copy_elt *a = (const struct name_to_copy_elt *) aa; |
5f40b3cb ZD |
331 | |
332 | return (hashval_t) a->version; | |
333 | } | |
334 | ||
335 | /* Returns true if the iterations of LOOP are independent on each other (that | |
336 | is, if we can execute them in parallel), and if LOOP satisfies other | |
337 | conditions that we need to be able to parallelize it. Description of number | |
a509ebb5 RL |
338 | of iterations is stored to NITER. Reduction analysis is done, if |
339 | reductions are found, they are inserted to the REDUCTION_LIST. */ | |
5f40b3cb ZD |
340 | |
341 | static bool | |
a509ebb5 | 342 | loop_parallel_p (struct loop *loop, htab_t reduction_list, struct tree_niter_desc *niter) |
5f40b3cb ZD |
343 | { |
344 | edge exit = single_dom_exit (loop); | |
a509ebb5 RL |
345 | VEC (ddr_p, heap) * dependence_relations; |
346 | VEC (data_reference_p, heap) * datarefs; | |
5f40b3cb ZD |
347 | lambda_trans_matrix trans; |
348 | bool ret = false; | |
349 | tree phi; | |
a509ebb5 | 350 | loop_vec_info simple_loop_info; |
5f40b3cb ZD |
351 | |
352 | /* Only consider innermost loops with just one exit. The innermost-loop | |
353 | restriction is not necessary, but it makes things simpler. */ | |
354 | if (loop->inner || !exit) | |
355 | return false; | |
356 | ||
357 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
358 | fprintf (dump_file, "\nConsidering loop %d\n", loop->num); | |
359 | ||
360 | /* We need to know # of iterations, and there should be no uses of values | |
361 | defined inside loop outside of it, unless the values are invariants of | |
362 | the loop. */ | |
363 | if (!number_of_iterations_exit (loop, exit, niter, false)) | |
364 | { | |
365 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
366 | fprintf (dump_file, " FAILED: number of iterations not known\n"); | |
367 | return false; | |
368 | } | |
369 | ||
a509ebb5 RL |
370 | simple_loop_info = vect_analyze_loop_form (loop); |
371 | ||
372 | for (phi = phi_nodes (loop->header); phi; phi = PHI_CHAIN (phi)) | |
373 | { | |
374 | tree reduc_stmt = NULL, operation; | |
375 | ||
376 | /* ??? TODO: Change this into a generic function that | |
377 | recognizes reductions. */ | |
378 | if (!is_gimple_reg (PHI_RESULT (phi))) | |
379 | continue; | |
380 | if (simple_loop_info) | |
381 | reduc_stmt = vect_is_simple_reduction (simple_loop_info, phi); | |
382 | ||
383 | /* Create a reduction_info struct, initialize it and insert it to | |
384 | the reduction list. */ | |
385 | ||
386 | if (reduc_stmt) | |
387 | { | |
388 | PTR *slot; | |
389 | struct reduction_info *new_reduction; | |
390 | ||
391 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
392 | { | |
393 | fprintf (dump_file, | |
394 | "Detected reduction. reduction stmt is: \n"); | |
395 | print_generic_stmt (dump_file, reduc_stmt, 0); | |
396 | fprintf (dump_file, "\n"); | |
397 | } | |
398 | ||
399 | new_reduction = XCNEW (struct reduction_info); | |
400 | ||
401 | new_reduction->reduc_stmt = reduc_stmt; | |
402 | new_reduction->reduc_phi = phi; | |
403 | operation = GIMPLE_STMT_OPERAND (reduc_stmt, 1); | |
404 | new_reduction->reduction_code = TREE_CODE (operation); | |
405 | slot = htab_find_slot (reduction_list, new_reduction, INSERT); | |
406 | *slot = new_reduction; | |
407 | } | |
408 | } | |
409 | ||
5f40b3cb ZD |
410 | for (phi = phi_nodes (exit->dest); phi; phi = PHI_CHAIN (phi)) |
411 | { | |
a509ebb5 RL |
412 | struct reduction_info *red; |
413 | imm_use_iterator imm_iter; | |
414 | use_operand_p use_p; | |
415 | tree reduc_phi; | |
416 | ||
5f40b3cb ZD |
417 | tree val = PHI_ARG_DEF_FROM_EDGE (phi, exit); |
418 | ||
419 | if (is_gimple_reg (val)) | |
420 | { | |
421 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
a509ebb5 RL |
422 | { |
423 | fprintf (dump_file, "phi is "); | |
424 | print_generic_expr (dump_file, phi, 0); | |
425 | fprintf (dump_file, "arg of phi to exit: value "); | |
426 | print_generic_expr (dump_file, val, 0); | |
427 | fprintf (dump_file, " used outside loop\n"); | |
428 | fprintf (dump_file, | |
429 | " checking if it a part of reduction pattern: \n"); | |
430 | } | |
431 | if (htab_elements (reduction_list) == 0) | |
432 | { | |
433 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
434 | fprintf (dump_file, | |
435 | " FAILED: it is not a part of reduction.\n"); | |
436 | return false; | |
437 | } | |
438 | reduc_phi = NULL; | |
439 | FOR_EACH_IMM_USE_FAST (use_p, imm_iter, val) | |
440 | { | |
441 | if (flow_bb_inside_loop_p (loop, bb_for_stmt (USE_STMT (use_p)))) | |
442 | { | |
443 | reduc_phi = USE_STMT (use_p); | |
444 | break; | |
445 | } | |
446 | } | |
447 | red = reduction_phi (reduction_list, reduc_phi); | |
448 | if (red == NULL) | |
449 | { | |
450 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
451 | fprintf (dump_file, | |
452 | " FAILED: it is not a part of reduction.\n"); | |
453 | return false; | |
454 | } | |
455 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
456 | { | |
457 | fprintf (dump_file, "reduction phi is "); | |
458 | print_generic_expr (dump_file, red->reduc_phi, 0); | |
459 | fprintf (dump_file, "reduction stmt is "); | |
460 | print_generic_expr (dump_file, red->reduc_stmt, 0); | |
461 | } | |
462 | ||
5f40b3cb ZD |
463 | } |
464 | } | |
465 | ||
466 | /* The iterations of the loop may communicate only through bivs whose | |
467 | iteration space can be distributed efficiently. */ | |
468 | for (phi = phi_nodes (loop->header); phi; phi = PHI_CHAIN (phi)) | |
469 | { | |
470 | tree def = PHI_RESULT (phi); | |
471 | affine_iv iv; | |
472 | ||
a509ebb5 | 473 | if (is_gimple_reg (def) && !simple_iv (loop, phi, def, &iv, true)) |
5f40b3cb | 474 | { |
a509ebb5 RL |
475 | struct reduction_info *red; |
476 | ||
477 | red = reduction_phi (reduction_list, phi); | |
478 | if (red == NULL) | |
479 | { | |
480 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
481 | fprintf (dump_file, | |
482 | " FAILED: scalar dependency between iterations\n"); | |
483 | return false; | |
484 | } | |
5f40b3cb ZD |
485 | } |
486 | } | |
487 | ||
488 | /* We need to version the loop to verify assumptions in runtime. */ | |
489 | if (!can_duplicate_loop_p (loop)) | |
490 | { | |
491 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
492 | fprintf (dump_file, " FAILED: cannot be duplicated\n"); | |
493 | return false; | |
494 | } | |
495 | ||
496 | /* Check for problems with dependences. If the loop can be reversed, | |
497 | the iterations are independent. */ | |
498 | datarefs = VEC_alloc (data_reference_p, heap, 10); | |
499 | dependence_relations = VEC_alloc (ddr_p, heap, 10 * 10); | |
500 | compute_data_dependences_for_loop (loop, true, &datarefs, | |
501 | &dependence_relations); | |
502 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
503 | dump_data_dependence_relations (dump_file, dependence_relations); | |
504 | ||
505 | trans = lambda_trans_matrix_new (1, 1); | |
506 | LTM_MATRIX (trans)[0][0] = -1; | |
507 | ||
508 | if (lambda_transform_legal_p (trans, 1, dependence_relations)) | |
509 | { | |
510 | ret = true; | |
511 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
512 | fprintf (dump_file, " SUCCESS: may be parallelized\n"); | |
513 | } | |
514 | else if (dump_file && (dump_flags & TDF_DETAILS)) | |
a509ebb5 RL |
515 | fprintf (dump_file, |
516 | " FAILED: data dependencies exist across iterations\n"); | |
5f40b3cb ZD |
517 | |
518 | free_dependence_relations (dependence_relations); | |
519 | free_data_refs (datarefs); | |
520 | ||
521 | return ret; | |
522 | } | |
523 | ||
524 | /* Assigns the address of VAR in TYPE to an ssa name, and returns this name. | |
525 | The assignment statement is placed before LOOP. DECL_ADDRESS maps decls | |
526 | to their addresses that can be reused. */ | |
527 | ||
528 | static tree | |
529 | take_address_of (tree var, tree type, struct loop *loop, htab_t decl_address) | |
530 | { | |
531 | int uid = DECL_UID (var); | |
532 | void **dslot; | |
533 | struct int_tree_map ielt, *nielt; | |
534 | tree name, bvar, stmt; | |
535 | edge entry = loop_preheader_edge (loop); | |
536 | ||
537 | ielt.uid = uid; | |
538 | dslot = htab_find_slot_with_hash (decl_address, &ielt, uid, INSERT); | |
539 | if (!*dslot) | |
540 | { | |
541 | bvar = create_tmp_var (type, get_name (var)); | |
542 | add_referenced_var (bvar); | |
543 | stmt = build_gimple_modify_stmt (bvar, | |
a509ebb5 RL |
544 | fold_convert (type, |
545 | build_addr (var, | |
546 | current_function_decl))); | |
5f40b3cb ZD |
547 | name = make_ssa_name (bvar, stmt); |
548 | GIMPLE_STMT_OPERAND (stmt, 0) = name; | |
549 | bsi_insert_on_edge_immediate (entry, stmt); | |
550 | ||
551 | nielt = XNEW (struct int_tree_map); | |
552 | nielt->uid = uid; | |
553 | nielt->to = name; | |
554 | *dslot = nielt; | |
555 | ||
556 | return name; | |
557 | } | |
558 | ||
559 | name = ((struct int_tree_map *) *dslot)->to; | |
560 | if (TREE_TYPE (name) == type) | |
561 | return name; | |
562 | ||
563 | bvar = SSA_NAME_VAR (name); | |
a509ebb5 | 564 | stmt = build_gimple_modify_stmt (bvar, fold_convert (type, name)); |
5f40b3cb ZD |
565 | name = make_ssa_name (bvar, stmt); |
566 | GIMPLE_STMT_OPERAND (stmt, 0) = name; | |
567 | bsi_insert_on_edge_immediate (entry, stmt); | |
568 | ||
569 | return name; | |
570 | } | |
571 | ||
a509ebb5 RL |
572 | /* Callback for htab_traverse. Create the initialization statement |
573 | for reduction described in SLOT, and place it at the preheader of | |
574 | the loop described in DATA. */ | |
575 | ||
576 | static int | |
577 | initialize_reductions (void **slot, void *data) | |
578 | { | |
579 | tree t, stmt; | |
580 | tree init, c; | |
581 | tree name, name1; | |
582 | tree bvar, type, arg; | |
583 | edge e; | |
584 | ||
585 | struct reduction_info *reduc = *slot; | |
586 | struct loop *loop = (struct loop *) data; | |
587 | ||
588 | /* Create initialization in preheader: | |
589 | reduction_variable = initialization value of reduction. */ | |
590 | ||
591 | /* In the phi node at the header, replace the argument coming | |
592 | from the preheader with the reduction initialization value. */ | |
593 | ||
594 | /* Create a new variable to initialize the reduction. */ | |
595 | type = TREE_TYPE (PHI_RESULT (reduc->reduc_phi)); | |
596 | bvar = create_tmp_var (type, "reduction"); | |
597 | add_referenced_var (bvar); | |
598 | ||
599 | c = build_omp_clause (OMP_CLAUSE_REDUCTION); | |
600 | OMP_CLAUSE_REDUCTION_CODE (c) = reduc->reduction_code; | |
601 | OMP_CLAUSE_DECL (c) = | |
602 | SSA_NAME_VAR (GIMPLE_STMT_OPERAND (reduc->reduc_stmt, 0)); | |
603 | ||
604 | init = omp_reduction_init (c, TREE_TYPE (bvar)); | |
605 | reduc->init = init; | |
606 | ||
607 | t = build_gimple_modify_stmt (bvar, init); | |
608 | name = make_ssa_name (bvar, t); | |
609 | ||
610 | GIMPLE_STMT_OPERAND (t, 0) = name; | |
611 | SSA_NAME_DEF_STMT (name) = t; | |
612 | ||
613 | /* Replace the argument | |
614 | representing the initialization value. Keeping the old value | |
615 | in a new variable "reduction_initial", that will be taken in | |
616 | consideration after the parallel computing is done. */ | |
617 | ||
618 | e = loop_preheader_edge (loop); | |
619 | arg = PHI_ARG_DEF_FROM_EDGE (reduc->reduc_phi, e); | |
620 | /* Create new variable to hold the initial value. */ | |
621 | type = TREE_TYPE (bvar); | |
622 | bvar = create_tmp_var (type, "reduction_initial"); | |
623 | add_referenced_var (bvar); | |
624 | ||
625 | stmt = build_gimple_modify_stmt (bvar, arg); | |
626 | name1 = make_ssa_name (bvar, stmt); | |
627 | GIMPLE_STMT_OPERAND (stmt, 0) = name1; | |
628 | SSA_NAME_DEF_STMT (name1) = stmt; | |
629 | ||
630 | bsi_insert_on_edge_immediate (e, stmt); | |
631 | bsi_insert_on_edge_immediate (e, t); | |
632 | SET_USE (PHI_ARG_DEF_PTR_FROM_EDGE | |
633 | (reduc->reduc_phi, loop_preheader_edge (loop)), name); | |
634 | reduc->initial_value = name1; | |
635 | reduc->reduction_init = name; | |
636 | return 1; | |
637 | } | |
5f40b3cb ZD |
638 | |
639 | struct elv_data | |
640 | { | |
641 | struct loop *loop; | |
642 | htab_t decl_address; | |
643 | bool changed; | |
644 | }; | |
645 | ||
a509ebb5 RL |
646 | /* Eliminates references to local variables in *TP out of LOOP. DECL_ADDRESS |
647 | contains addresses of the references that had their address taken already. | |
648 | If the expression is changed, CHANGED is set to true. Callback for | |
649 | walk_tree. */ | |
650 | ||
5f40b3cb | 651 | static tree |
a509ebb5 | 652 | eliminate_local_variables_1 (tree * tp, int *walk_subtrees, void *data) |
5f40b3cb ZD |
653 | { |
654 | struct elv_data *dta = data; | |
655 | tree t = *tp, var, addr, addr_type, type; | |
656 | ||
657 | if (DECL_P (t)) | |
658 | { | |
659 | *walk_subtrees = 0; | |
660 | ||
661 | if (!SSA_VAR_P (t) || DECL_EXTERNAL (t)) | |
662 | return NULL_TREE; | |
663 | ||
664 | type = TREE_TYPE (t); | |
665 | addr_type = build_pointer_type (type); | |
666 | addr = take_address_of (t, addr_type, dta->loop, dta->decl_address); | |
667 | *tp = build1 (INDIRECT_REF, TREE_TYPE (*tp), addr); | |
668 | ||
669 | dta->changed = true; | |
670 | return NULL_TREE; | |
671 | } | |
672 | ||
673 | if (TREE_CODE (t) == ADDR_EXPR) | |
674 | { | |
675 | var = TREE_OPERAND (t, 0); | |
676 | if (!DECL_P (var)) | |
677 | return NULL_TREE; | |
678 | ||
679 | *walk_subtrees = 0; | |
680 | if (!SSA_VAR_P (var) || DECL_EXTERNAL (var)) | |
681 | return NULL_TREE; | |
682 | ||
683 | addr_type = TREE_TYPE (t); | |
684 | addr = take_address_of (var, addr_type, dta->loop, dta->decl_address); | |
685 | *tp = addr; | |
686 | ||
687 | dta->changed = true; | |
688 | return NULL_TREE; | |
689 | } | |
690 | ||
a509ebb5 | 691 | if (!EXPR_P (t) && !GIMPLE_STMT_P (t)) |
5f40b3cb ZD |
692 | *walk_subtrees = 0; |
693 | ||
694 | return NULL_TREE; | |
695 | } | |
696 | ||
697 | /* Moves the references to local variables in STMT from LOOP. DECL_ADDRESS | |
698 | contains addresses for the references for that we have already taken | |
699 | them. */ | |
700 | ||
701 | static void | |
702 | eliminate_local_variables_stmt (struct loop *loop, tree stmt, | |
703 | htab_t decl_address) | |
704 | { | |
705 | struct elv_data dta; | |
706 | ||
707 | dta.loop = loop; | |
708 | dta.decl_address = decl_address; | |
709 | dta.changed = false; | |
710 | ||
711 | walk_tree (&stmt, eliminate_local_variables_1, &dta, NULL); | |
712 | ||
713 | if (dta.changed) | |
714 | update_stmt (stmt); | |
715 | } | |
716 | ||
a509ebb5 RL |
717 | /* Eliminates the references to local variables from LOOP. |
718 | This includes: | |
719 | 1) Taking address of a local variable -- these are moved out of the | |
720 | loop (and temporary variable is created to hold the address if | |
721 | necessary). | |
5f40b3cb | 722 | 2) Dereferencing a local variable -- these are replaced with indirect |
a509ebb5 | 723 | references. */ |
5f40b3cb ZD |
724 | |
725 | static void | |
726 | eliminate_local_variables (struct loop *loop) | |
727 | { | |
728 | basic_block bb, *body = get_loop_body (loop); | |
729 | unsigned i; | |
730 | block_stmt_iterator bsi; | |
731 | htab_t decl_address = htab_create (10, int_tree_map_hash, int_tree_map_eq, | |
732 | free); | |
733 | ||
734 | /* Find and rename the ssa names defined outside of loop. */ | |
735 | for (i = 0; i < loop->num_nodes; i++) | |
736 | { | |
737 | bb = body[i]; | |
738 | ||
739 | for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi)) | |
740 | eliminate_local_variables_stmt (loop, bsi_stmt (bsi), decl_address); | |
741 | } | |
742 | ||
743 | htab_delete (decl_address); | |
744 | } | |
745 | ||
746 | /* If COPY_NAME_P is true, creates and returns a duplicate of NAME. | |
747 | The copies are stored to NAME_COPIES, if NAME was already duplicated, | |
748 | its duplicate stored in NAME_COPIES is returned. | |
749 | ||
750 | Regardless of COPY_NAME_P, the decl used as a base of the ssa name is also | |
751 | duplicated, storing the copies in DECL_COPIES. */ | |
752 | ||
753 | static tree | |
754 | separate_decls_in_loop_name (tree name, | |
755 | htab_t name_copies, htab_t decl_copies, | |
756 | bool copy_name_p) | |
757 | { | |
758 | tree copy, var, var_copy; | |
759 | unsigned idx, uid, nuid; | |
760 | struct int_tree_map ielt, *nielt; | |
761 | struct name_to_copy_elt elt, *nelt; | |
762 | void **slot, **dslot; | |
763 | ||
764 | if (TREE_CODE (name) != SSA_NAME) | |
765 | return name; | |
766 | ||
767 | idx = SSA_NAME_VERSION (name); | |
768 | elt.version = idx; | |
769 | slot = htab_find_slot_with_hash (name_copies, &elt, idx, | |
770 | copy_name_p ? INSERT : NO_INSERT); | |
771 | if (slot && *slot) | |
772 | return ((struct name_to_copy_elt *) *slot)->new_name; | |
773 | ||
774 | var = SSA_NAME_VAR (name); | |
775 | uid = DECL_UID (var); | |
776 | ielt.uid = uid; | |
777 | dslot = htab_find_slot_with_hash (decl_copies, &ielt, uid, INSERT); | |
778 | if (!*dslot) | |
779 | { | |
780 | var_copy = create_tmp_var (TREE_TYPE (var), get_name (var)); | |
781 | add_referenced_var (var_copy); | |
782 | nielt = XNEW (struct int_tree_map); | |
783 | nielt->uid = uid; | |
784 | nielt->to = var_copy; | |
785 | *dslot = nielt; | |
786 | ||
787 | /* Ensure that when we meet this decl next time, we won't duplicate | |
a509ebb5 | 788 | it again. */ |
5f40b3cb ZD |
789 | nuid = DECL_UID (var_copy); |
790 | ielt.uid = nuid; | |
791 | dslot = htab_find_slot_with_hash (decl_copies, &ielt, nuid, INSERT); | |
792 | gcc_assert (!*dslot); | |
793 | nielt = XNEW (struct int_tree_map); | |
794 | nielt->uid = nuid; | |
795 | nielt->to = var_copy; | |
796 | *dslot = nielt; | |
797 | } | |
798 | else | |
799 | var_copy = ((struct int_tree_map *) *dslot)->to; | |
800 | ||
801 | if (copy_name_p) | |
802 | { | |
803 | copy = duplicate_ssa_name (name, NULL_TREE); | |
804 | nelt = XNEW (struct name_to_copy_elt); | |
805 | nelt->version = idx; | |
806 | nelt->new_name = copy; | |
807 | nelt->field = NULL_TREE; | |
808 | *slot = nelt; | |
809 | } | |
810 | else | |
811 | { | |
812 | gcc_assert (!slot); | |
813 | copy = name; | |
814 | } | |
815 | ||
816 | SSA_NAME_VAR (copy) = var_copy; | |
817 | return copy; | |
818 | } | |
819 | ||
820 | /* Finds the ssa names used in STMT that are defined outside of LOOP and | |
821 | replaces such ssa names with their duplicates. The duplicates are stored to | |
822 | NAME_COPIES. Base decls of all ssa names used in STMT | |
823 | (including those defined in LOOP) are replaced with the new temporary | |
824 | variables; the replacement decls are stored in DECL_COPIES. */ | |
825 | ||
826 | static void | |
827 | separate_decls_in_loop_stmt (struct loop *loop, tree stmt, | |
828 | htab_t name_copies, htab_t decl_copies) | |
829 | { | |
830 | use_operand_p use; | |
831 | def_operand_p def; | |
832 | ssa_op_iter oi; | |
833 | tree name, copy; | |
834 | bool copy_name_p; | |
835 | ||
836 | mark_virtual_ops_for_renaming (stmt); | |
837 | ||
838 | FOR_EACH_PHI_OR_STMT_DEF (def, stmt, oi, SSA_OP_DEF) | |
a509ebb5 RL |
839 | { |
840 | name = DEF_FROM_PTR (def); | |
841 | gcc_assert (TREE_CODE (name) == SSA_NAME); | |
842 | copy = separate_decls_in_loop_name (name, name_copies, decl_copies, | |
843 | false); | |
844 | gcc_assert (copy == name); | |
845 | } | |
5f40b3cb ZD |
846 | |
847 | FOR_EACH_PHI_OR_STMT_USE (use, stmt, oi, SSA_OP_USE) | |
a509ebb5 RL |
848 | { |
849 | name = USE_FROM_PTR (use); | |
850 | if (TREE_CODE (name) != SSA_NAME) | |
851 | continue; | |
852 | ||
853 | copy_name_p = expr_invariant_in_loop_p (loop, name); | |
854 | copy = separate_decls_in_loop_name (name, name_copies, decl_copies, | |
855 | copy_name_p); | |
856 | SET_USE (use, copy); | |
857 | } | |
5f40b3cb ZD |
858 | } |
859 | ||
a509ebb5 RL |
860 | /* A helper structure for passing the TYPE and REDUCTION_LIST |
861 | to the DATA parameter of add_field_for_name. */ | |
862 | struct data_arg | |
863 | { | |
864 | tree type; | |
865 | htab_t reduction_list; | |
866 | }; | |
867 | ||
5f40b3cb | 868 | /* Callback for htab_traverse. Adds a field corresponding to a ssa name |
a509ebb5 RL |
869 | described in SLOT. The type is passed in DATA. The Reduction list |
870 | is also passes in DATA. */ | |
5f40b3cb ZD |
871 | |
872 | static int | |
873 | add_field_for_name (void **slot, void *data) | |
874 | { | |
a509ebb5 RL |
875 | tree stmt; |
876 | use_operand_p use_p = NULL; | |
877 | ||
5f40b3cb | 878 | struct name_to_copy_elt *elt = *slot; |
a509ebb5 RL |
879 | struct data_arg *data_arg = (struct data_arg *) data; |
880 | tree type = data_arg->type; | |
5f40b3cb ZD |
881 | tree name = ssa_name (elt->version); |
882 | tree var = SSA_NAME_VAR (name); | |
883 | tree field = build_decl (FIELD_DECL, DECL_NAME (var), TREE_TYPE (var)); | |
884 | ||
885 | insert_field_into_struct (type, field); | |
886 | elt->field = field; | |
a509ebb5 RL |
887 | |
888 | /* Find uses of name to determine if this name is related to | |
889 | a reduction phi, and if so, record the field in the reduction struct. */ | |
890 | ||
891 | if ((htab_elements (data_arg->reduction_list) > 0) | |
892 | && single_imm_use (elt->new_name, &use_p, &stmt) | |
893 | && TREE_CODE (stmt) == PHI_NODE) | |
894 | { | |
895 | /* check if STMT is a REDUC_PHI of some reduction. */ | |
896 | struct reduction_info *red; | |
897 | ||
898 | red = reduction_phi (data_arg->reduction_list ,stmt); | |
899 | if (red) | |
900 | red->field = field; | |
901 | } | |
902 | ||
5f40b3cb ZD |
903 | return 1; |
904 | } | |
905 | ||
a509ebb5 RL |
906 | /* Callback for htab_traverse. A local result is the intermediate result |
907 | computed by a single | |
908 | thread, or the intial value in case no iteration was executed. | |
909 | This function creates a phi node reflecting these values. | |
910 | The phi's result will be stored in NEW_PHI field of the | |
911 | reduction's data structure. */ | |
912 | ||
913 | static int | |
914 | create_phi_for_local_result (void **slot, void *data) | |
915 | { | |
916 | struct reduction_info *reduc = *slot; | |
917 | struct loop *loop = data; | |
918 | edge e; | |
919 | tree new_phi; | |
920 | basic_block store_bb; | |
921 | tree local_res; | |
922 | ||
923 | /* STORE_BB is the block where the phi | |
924 | should be stored. It is the destination of the loop exit. | |
925 | (Find the fallthru edge from OMP_CONTINUE). */ | |
926 | store_bb = FALLTHRU_EDGE (loop->latch)->dest; | |
927 | ||
928 | /* STORE_BB has two predecessors. One coming from the loop | |
929 | (the reduction's result is computed at the loop), | |
930 | and another coming from a block preceding the loop, | |
931 | when no iterations | |
932 | are executed (the initial value should be taken). */ | |
933 | if (EDGE_PRED (store_bb, 0) == FALLTHRU_EDGE (loop->latch)) | |
934 | e = EDGE_PRED (store_bb, 1); | |
935 | else | |
936 | e = EDGE_PRED (store_bb, 0); | |
937 | local_res = make_ssa_name (SSA_NAME_VAR (reduc->reduction_init), NULL_TREE); | |
938 | new_phi = create_phi_node (local_res, store_bb); | |
939 | SSA_NAME_DEF_STMT (local_res) = new_phi; | |
940 | add_phi_arg (new_phi, reduc->init, e); | |
941 | add_phi_arg (new_phi, GIMPLE_STMT_OPERAND (reduc->reduc_stmt, 0), | |
942 | FALLTHRU_EDGE (loop->latch)); | |
943 | reduc->new_phi = new_phi; | |
944 | ||
945 | return 1; | |
946 | } | |
5f40b3cb ZD |
947 | |
948 | struct clsn_data | |
949 | { | |
950 | tree store; | |
951 | tree load; | |
952 | ||
953 | basic_block store_bb; | |
954 | basic_block load_bb; | |
955 | }; | |
956 | ||
a509ebb5 RL |
957 | /* Callback for htab_traverse. Create an atomic instruction for the |
958 | reduction described in SLOT. | |
959 | DATA annotates the place in memory the atomic operation relates to, | |
960 | and the basic block it needs to be generated in. */ | |
961 | ||
962 | static int | |
963 | create_call_for_reduction_1 (void **slot, void *data) | |
964 | { | |
965 | struct reduction_info *reduc = *slot; | |
966 | struct clsn_data *clsn_data = data; | |
967 | block_stmt_iterator bsi; | |
968 | tree type = TREE_TYPE (PHI_RESULT (reduc->reduc_phi)); | |
969 | tree struct_type = TREE_TYPE (TREE_TYPE (clsn_data->load)); | |
970 | tree load_struct; | |
971 | basic_block bb; | |
972 | basic_block new_bb; | |
973 | edge e; | |
974 | tree t, addr, addr_type, ref, x; | |
975 | tree tmp_load, load, name; | |
976 | ||
977 | load_struct = fold_build1 (INDIRECT_REF, struct_type, clsn_data->load); | |
978 | t = build3 (COMPONENT_REF, type, load_struct, reduc->field, NULL_TREE); | |
979 | addr_type = build_pointer_type (type); | |
980 | ||
981 | addr = build_addr (t, current_function_decl); | |
982 | ||
983 | /* Create phi node. */ | |
984 | bb = clsn_data->load_bb; | |
985 | ||
986 | e = split_block (bb, t); | |
987 | new_bb = e->dest; | |
988 | ||
989 | tmp_load = create_tmp_var (TREE_TYPE (TREE_TYPE (addr)), NULL); | |
990 | add_referenced_var (tmp_load); | |
991 | tmp_load = make_ssa_name (tmp_load, NULL); | |
992 | load = build2 (OMP_ATOMIC_LOAD, void_type_node, tmp_load, addr); | |
993 | SSA_NAME_DEF_STMT (tmp_load) = load; | |
994 | bsi = bsi_start (new_bb); | |
995 | bsi_insert_after (&bsi, load, BSI_NEW_STMT); | |
996 | ||
997 | e = split_block (new_bb, load); | |
998 | new_bb = e->dest; | |
999 | bsi = bsi_start (new_bb); | |
1000 | ref = tmp_load; | |
1001 | x = | |
1002 | fold_build2 (reduc->reduction_code, | |
1003 | TREE_TYPE (PHI_RESULT (reduc->new_phi)), ref, | |
1004 | PHI_RESULT (reduc->new_phi)); | |
1005 | ||
1006 | name = | |
1007 | force_gimple_operand_bsi (&bsi, x, true, NULL_TREE, true, | |
1008 | BSI_CONTINUE_LINKING); | |
1009 | ||
1010 | x = build1 (OMP_ATOMIC_STORE, void_type_node, name); | |
1011 | ||
1012 | bsi_insert_after (&bsi, x, BSI_NEW_STMT); | |
1013 | return 1; | |
1014 | } | |
1015 | ||
1016 | /* Create the atomic operation at the join point of the threads. | |
1017 | REDUCTION_LIST describes the reductions in the LOOP. | |
1018 | LD_ST_DATA describes the shared data structure where | |
1019 | shared data is stored in and loaded from. */ | |
1020 | static void | |
1021 | create_call_for_reduction (struct loop *loop, htab_t reduction_list, | |
1022 | struct clsn_data *ld_st_data) | |
1023 | { | |
1024 | htab_traverse (reduction_list, create_phi_for_local_result, loop); | |
1025 | /* Find the fallthru edge from OMP_CONTINUE. */ | |
1026 | ld_st_data->load_bb = FALLTHRU_EDGE (loop->latch)->dest; | |
1027 | htab_traverse (reduction_list, create_call_for_reduction_1, ld_st_data); | |
1028 | } | |
1029 | ||
1030 | /* Callback for htab_traverse. Create a new variable that loads the | |
1031 | final reduction value at the | |
1032 | join point of all threads, adds the initial value the reduction | |
1033 | variable had before the parallel computation started, and | |
1034 | inserts it in the right place. */ | |
1035 | ||
1036 | static int | |
1037 | create_loads_for_reductions (void **slot, void *data) | |
1038 | { | |
1039 | struct reduction_info *red = *slot; | |
1040 | struct clsn_data *clsn_data = data; | |
1041 | tree stmt; | |
1042 | block_stmt_iterator bsi; | |
1043 | tree type = TREE_TYPE (red->reduction_init); | |
1044 | tree struct_type = TREE_TYPE (TREE_TYPE (clsn_data->load)); | |
1045 | tree load_struct; | |
1046 | tree bvar, name; | |
1047 | tree x; | |
1048 | ||
1049 | bsi = bsi_after_labels (clsn_data->load_bb); | |
1050 | load_struct = fold_build1 (INDIRECT_REF, struct_type, clsn_data->load); | |
1051 | load_struct = build3 (COMPONENT_REF, type, load_struct, red->field, | |
1052 | NULL_TREE); | |
1053 | bvar = create_tmp_var (type, "reduction_final"); | |
1054 | add_referenced_var (bvar); | |
1055 | ||
1056 | /* Apply operation between the new variable which is the result | |
1057 | of computation all threads, and the initial value which is kept | |
1058 | at reduction->inital_value. */ | |
1059 | ||
1060 | stmt = build_gimple_modify_stmt (bvar, load_struct); | |
1061 | name = make_ssa_name (bvar, stmt); | |
1062 | GIMPLE_STMT_OPERAND (stmt, 0) = name; | |
1063 | SSA_NAME_DEF_STMT (name) = stmt; | |
1064 | ||
1065 | bsi_insert_after (&bsi, stmt, BSI_NEW_STMT); | |
1066 | ||
1067 | x = | |
1068 | fold_build2 (red->reduction_code, TREE_TYPE (load_struct), | |
1069 | name, red->initial_value); | |
1070 | name = PHI_RESULT (red->keep_res); | |
1071 | stmt = build_gimple_modify_stmt (name, x); | |
1072 | GIMPLE_STMT_OPERAND (stmt, 0) = name; | |
1073 | SSA_NAME_DEF_STMT (name) = stmt; | |
1074 | ||
1075 | bsi_insert_after (&bsi, stmt, BSI_NEW_STMT); | |
1076 | ||
1077 | remove_phi_node (red->keep_res, NULL_TREE, false); | |
1078 | ||
1079 | return 1; | |
1080 | } | |
1081 | ||
1082 | /* Load the reduction result that was stored in LD_ST_DATA. | |
1083 | REDUCTION_LIST describes the list of reductions that the | |
1084 | loades should be generated for. */ | |
1085 | static void | |
1086 | create_final_loads_for_reduction (htab_t reduction_list, | |
1087 | struct clsn_data *ld_st_data) | |
1088 | { | |
1089 | block_stmt_iterator bsi; | |
1090 | tree t; | |
1091 | ||
1092 | bsi = bsi_after_labels (ld_st_data->load_bb); | |
1093 | t = build_fold_addr_expr (ld_st_data->store); | |
1094 | t = | |
1095 | build_gimple_modify_stmt (ld_st_data->load, | |
1096 | build_fold_addr_expr (ld_st_data->store)); | |
1097 | ||
1098 | bsi_insert_before (&bsi, t, BSI_NEW_STMT); | |
1099 | SSA_NAME_DEF_STMT (ld_st_data->load) = t; | |
1100 | GIMPLE_STMT_OPERAND (t, 0) = ld_st_data->load; | |
1101 | ||
1102 | htab_traverse (reduction_list, create_loads_for_reductions, ld_st_data); | |
1103 | ||
1104 | } | |
1105 | ||
1106 | /* Callback for htab_traverse. Creates loads to a field of LOAD in LOAD_BB and | |
1107 | store to a field of STORE in STORE_BB for the ssa name and its duplicate | |
1108 | specified in SLOT. */ | |
1109 | ||
5f40b3cb ZD |
1110 | static int |
1111 | create_loads_and_stores_for_name (void **slot, void *data) | |
1112 | { | |
1113 | struct name_to_copy_elt *elt = *slot; | |
1114 | struct clsn_data *clsn_data = data; | |
1115 | tree stmt; | |
1116 | block_stmt_iterator bsi; | |
1117 | tree type = TREE_TYPE (elt->new_name); | |
1118 | tree struct_type = TREE_TYPE (TREE_TYPE (clsn_data->load)); | |
1119 | tree load_struct; | |
1120 | ||
1121 | bsi = bsi_last (clsn_data->store_bb); | |
a509ebb5 RL |
1122 | stmt = |
1123 | build_gimple_modify_stmt (build3 | |
1124 | (COMPONENT_REF, type, clsn_data->store, | |
1125 | elt->field, NULL_TREE), | |
1126 | ssa_name (elt->version)); | |
5f40b3cb ZD |
1127 | mark_virtual_ops_for_renaming (stmt); |
1128 | bsi_insert_after (&bsi, stmt, BSI_NEW_STMT); | |
1129 | ||
1130 | bsi = bsi_last (clsn_data->load_bb); | |
1131 | load_struct = fold_build1 (INDIRECT_REF, struct_type, clsn_data->load); | |
a509ebb5 RL |
1132 | stmt = build_gimple_modify_stmt (elt->new_name, |
1133 | build3 (COMPONENT_REF, type, load_struct, | |
1134 | elt->field, NULL_TREE)); | |
5f40b3cb ZD |
1135 | SSA_NAME_DEF_STMT (elt->new_name) = stmt; |
1136 | bsi_insert_after (&bsi, stmt, BSI_NEW_STMT); | |
1137 | ||
1138 | return 1; | |
1139 | } | |
1140 | ||
1141 | /* Moves all the variables used in LOOP and defined outside of it (including | |
1142 | the initial values of loop phi nodes, and *PER_THREAD if it is a ssa | |
1143 | name) to a structure created for this purpose. The code | |
1144 | ||
1145 | while (1) | |
1146 | { | |
1147 | use (a); | |
1148 | use (b); | |
1149 | } | |
1150 | ||
1151 | is transformed this way: | |
1152 | ||
1153 | bb0: | |
1154 | old.a = a; | |
1155 | old.b = b; | |
1156 | ||
1157 | bb1: | |
1158 | a' = new->a; | |
1159 | b' = new->b; | |
1160 | while (1) | |
1161 | { | |
1162 | use (a'); | |
1163 | use (b'); | |
1164 | } | |
1165 | ||
1166 | `old' is stored to *ARG_STRUCT and `new' is stored to NEW_ARG_STRUCT. The | |
1167 | pointer `new' is intentionally not initialized (the loop will be split to a | |
1168 | separate function later, and `new' will be initialized from its arguments). | |
a509ebb5 RL |
1169 | LD_ST_DATA holds information about the shared data structure used to pass |
1170 | information among the threads. It is initialized here, and | |
1171 | gen_parallel_loop will pass it to create_call_for_reduction that | |
1172 | needs this information. REDUCTION_LIST describes the reductions | |
1173 | in LOOP. */ | |
5f40b3cb ZD |
1174 | |
1175 | static void | |
a509ebb5 RL |
1176 | separate_decls_in_loop (struct loop *loop, htab_t reduction_list, |
1177 | tree * arg_struct, tree * new_arg_struct, | |
1178 | struct clsn_data *ld_st_data) | |
1179 | ||
5f40b3cb ZD |
1180 | { |
1181 | basic_block bb1 = split_edge (loop_preheader_edge (loop)); | |
1182 | basic_block bb0 = single_pred (bb1); | |
1183 | htab_t name_copies = htab_create (10, name_to_copy_elt_hash, | |
1184 | name_to_copy_elt_eq, free); | |
1185 | htab_t decl_copies = htab_create (10, int_tree_map_hash, int_tree_map_eq, | |
1186 | free); | |
1187 | basic_block bb, *body = get_loop_body (loop); | |
1188 | unsigned i; | |
1189 | tree phi, type, type_name, nvar; | |
1190 | block_stmt_iterator bsi; | |
1191 | struct clsn_data clsn_data; | |
1192 | ||
1193 | /* Find and rename the ssa names defined outside of loop. */ | |
1194 | for (i = 0; i < loop->num_nodes; i++) | |
1195 | { | |
1196 | bb = body[i]; | |
1197 | ||
1198 | for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi)) | |
1199 | separate_decls_in_loop_stmt (loop, phi, name_copies, decl_copies); | |
1200 | ||
1201 | for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi)) | |
1202 | separate_decls_in_loop_stmt (loop, bsi_stmt (bsi), name_copies, | |
1203 | decl_copies); | |
1204 | } | |
1205 | free (body); | |
1206 | ||
1207 | if (htab_elements (name_copies) == 0) | |
1208 | { | |
1209 | /* It may happen that there is nothing to copy (if there are only | |
a509ebb5 | 1210 | loop carried and external variables in the loop). */ |
5f40b3cb ZD |
1211 | *arg_struct = NULL; |
1212 | *new_arg_struct = NULL; | |
1213 | } | |
1214 | else | |
1215 | { | |
a509ebb5 RL |
1216 | struct data_arg data_arg; |
1217 | ||
5f40b3cb ZD |
1218 | /* Create the type for the structure to store the ssa names to. */ |
1219 | type = lang_hooks.types.make_type (RECORD_TYPE); | |
1220 | type_name = build_decl (TYPE_DECL, create_tmp_var_name (".paral_data"), | |
1221 | type); | |
1222 | TYPE_NAME (type) = type_name; | |
1223 | ||
a509ebb5 RL |
1224 | data_arg.type = type; |
1225 | data_arg.reduction_list = reduction_list; | |
1226 | htab_traverse (name_copies, add_field_for_name, &data_arg); | |
5f40b3cb ZD |
1227 | layout_type (type); |
1228 | ||
1229 | /* Create the loads and stores. */ | |
1230 | *arg_struct = create_tmp_var (type, ".paral_data_store"); | |
1231 | add_referenced_var (*arg_struct); | |
1232 | nvar = create_tmp_var (build_pointer_type (type), ".paral_data_load"); | |
1233 | add_referenced_var (nvar); | |
1234 | *new_arg_struct = make_ssa_name (nvar, NULL_TREE); | |
1235 | ||
a509ebb5 RL |
1236 | ld_st_data->store = *arg_struct; |
1237 | ld_st_data->load = *new_arg_struct; | |
1238 | ld_st_data->store_bb = bb0; | |
1239 | ld_st_data->load_bb = bb1; | |
5f40b3cb | 1240 | htab_traverse (name_copies, create_loads_and_stores_for_name, |
a509ebb5 RL |
1241 | ld_st_data); |
1242 | ||
1243 | /* Load the calculation from memory into a new | |
1244 | reduction variable (after the join of the threads). */ | |
1245 | if (htab_elements (reduction_list) > 0) | |
1246 | { | |
1247 | clsn_data.load = make_ssa_name (nvar, NULL_TREE); | |
1248 | clsn_data.load_bb = single_dom_exit (loop)->dest; | |
1249 | clsn_data.store = ld_st_data->store; | |
1250 | create_final_loads_for_reduction (reduction_list, &clsn_data); | |
1251 | } | |
5f40b3cb ZD |
1252 | } |
1253 | ||
1254 | htab_delete (decl_copies); | |
1255 | htab_delete (name_copies); | |
1256 | } | |
1257 | ||
1258 | /* Bitmap containing uids of functions created by parallelization. We cannot | |
1259 | allocate it from the default obstack, as it must live across compilation | |
1260 | of several functions; we make it gc allocated instead. */ | |
1261 | ||
1262 | static GTY(()) bitmap parallelized_functions; | |
1263 | ||
1264 | /* Returns true if FN was created by create_loop_fn. */ | |
1265 | ||
1266 | static bool | |
1267 | parallelized_function_p (tree fn) | |
1268 | { | |
1269 | if (!parallelized_functions || !DECL_ARTIFICIAL (fn)) | |
1270 | return false; | |
1271 | ||
1272 | return bitmap_bit_p (parallelized_functions, DECL_UID (fn)); | |
1273 | } | |
1274 | ||
1275 | /* Creates and returns an empty function that will receive the body of | |
1276 | a parallelized loop. */ | |
1277 | ||
1278 | static tree | |
1279 | create_loop_fn (void) | |
1280 | { | |
1281 | char buf[100]; | |
1282 | char *tname; | |
1283 | tree decl, type, name, t; | |
1284 | struct function *act_cfun = cfun; | |
1285 | static unsigned loopfn_num; | |
1286 | ||
1287 | snprintf (buf, 100, "%s.$loopfn", current_function_name ()); | |
1288 | ASM_FORMAT_PRIVATE_NAME (tname, buf, loopfn_num++); | |
1289 | clean_symbol_name (tname); | |
1290 | name = get_identifier (tname); | |
1291 | type = build_function_type_list (void_type_node, ptr_type_node, NULL_TREE); | |
1292 | ||
1293 | decl = build_decl (FUNCTION_DECL, name, type); | |
1294 | if (!parallelized_functions) | |
1295 | parallelized_functions = BITMAP_GGC_ALLOC (); | |
1296 | bitmap_set_bit (parallelized_functions, DECL_UID (decl)); | |
1297 | ||
1298 | TREE_STATIC (decl) = 1; | |
1299 | TREE_USED (decl) = 1; | |
1300 | DECL_ARTIFICIAL (decl) = 1; | |
1301 | DECL_IGNORED_P (decl) = 0; | |
1302 | TREE_PUBLIC (decl) = 0; | |
1303 | DECL_UNINLINABLE (decl) = 1; | |
1304 | DECL_EXTERNAL (decl) = 0; | |
1305 | DECL_CONTEXT (decl) = NULL_TREE; | |
1306 | DECL_INITIAL (decl) = make_node (BLOCK); | |
1307 | ||
1308 | t = build_decl (RESULT_DECL, NULL_TREE, void_type_node); | |
1309 | DECL_ARTIFICIAL (t) = 1; | |
1310 | DECL_IGNORED_P (t) = 1; | |
1311 | DECL_RESULT (decl) = t; | |
1312 | ||
1313 | t = build_decl (PARM_DECL, get_identifier (".paral_data_param"), | |
1314 | ptr_type_node); | |
1315 | DECL_ARTIFICIAL (t) = 1; | |
1316 | DECL_ARG_TYPE (t) = ptr_type_node; | |
1317 | DECL_CONTEXT (t) = decl; | |
1318 | TREE_USED (t) = 1; | |
1319 | DECL_ARGUMENTS (decl) = t; | |
1320 | ||
1321 | allocate_struct_function (decl); | |
1322 | ||
1323 | /* The call to allocate_struct_function clobbers CFUN, so we need to restore | |
1324 | it. */ | |
1325 | cfun = act_cfun; | |
1326 | ||
1327 | return decl; | |
1328 | } | |
1329 | ||
1330 | /* Bases all the induction variables in LOOP on a single induction variable | |
1331 | (unsigned with base 0 and step 1), whose final value is compared with | |
a509ebb5 RL |
1332 | NIT. The induction variable is incremented in the loop latch. |
1333 | REDUCTION_LIST describes the reductions in LOOP. */ | |
5f40b3cb ZD |
1334 | |
1335 | static void | |
a509ebb5 | 1336 | canonicalize_loop_ivs (struct loop *loop, htab_t reduction_list, tree nit) |
5f40b3cb ZD |
1337 | { |
1338 | unsigned precision = TYPE_PRECISION (TREE_TYPE (nit)); | |
1339 | tree phi, prev, res, type, var_before, val, atype, t, next; | |
1340 | block_stmt_iterator bsi; | |
1341 | bool ok; | |
1342 | affine_iv iv; | |
1343 | edge exit = single_dom_exit (loop); | |
a509ebb5 | 1344 | struct reduction_info *red; |
5f40b3cb ZD |
1345 | |
1346 | for (phi = phi_nodes (loop->header); phi; phi = PHI_CHAIN (phi)) | |
1347 | { | |
1348 | res = PHI_RESULT (phi); | |
1349 | ||
a509ebb5 | 1350 | if (is_gimple_reg (res) && TYPE_PRECISION (TREE_TYPE (res)) > precision) |
5f40b3cb ZD |
1351 | precision = TYPE_PRECISION (TREE_TYPE (res)); |
1352 | } | |
1353 | ||
1354 | type = lang_hooks.types.type_for_size (precision, 1); | |
1355 | ||
1356 | bsi = bsi_last (loop->latch); | |
1357 | create_iv (build_int_cst_type (type, 0), build_int_cst (type, 1), NULL_TREE, | |
1358 | loop, &bsi, true, &var_before, NULL); | |
1359 | ||
1360 | bsi = bsi_after_labels (loop->header); | |
1361 | prev = NULL; | |
1362 | for (phi = phi_nodes (loop->header); phi; phi = next) | |
1363 | { | |
1364 | next = PHI_CHAIN (phi); | |
1365 | res = PHI_RESULT (phi); | |
1366 | ||
a509ebb5 | 1367 | if (!is_gimple_reg (res) || res == var_before) |
5f40b3cb ZD |
1368 | { |
1369 | prev = phi; | |
1370 | continue; | |
1371 | } | |
5f40b3cb | 1372 | |
a509ebb5 RL |
1373 | ok = simple_iv (loop, phi, res, &iv, true); |
1374 | red = reduction_phi (reduction_list, phi); | |
1375 | /* We preserve the reduction phi nodes. */ | |
1376 | if (!ok && red) | |
1377 | { | |
1378 | prev = phi; | |
1379 | continue; | |
1380 | } | |
1381 | else | |
1382 | gcc_assert (ok); | |
5f40b3cb ZD |
1383 | remove_phi_node (phi, prev, false); |
1384 | ||
1385 | atype = TREE_TYPE (res); | |
1386 | val = fold_build2 (PLUS_EXPR, atype, | |
1387 | unshare_expr (iv.base), | |
1388 | fold_build2 (MULT_EXPR, atype, | |
1389 | unshare_expr (iv.step), | |
1390 | fold_convert (atype, var_before))); | |
1391 | val = force_gimple_operand_bsi (&bsi, val, false, NULL_TREE, true, | |
1392 | BSI_SAME_STMT); | |
1393 | t = build_gimple_modify_stmt (res, val); | |
1394 | bsi_insert_before (&bsi, t, BSI_SAME_STMT); | |
1395 | SSA_NAME_DEF_STMT (res) = t; | |
1396 | } | |
1397 | ||
1398 | t = last_stmt (exit->src); | |
1399 | /* Make the loop exit if the control condition is not satisfied. */ | |
1400 | if (exit->flags & EDGE_TRUE_VALUE) | |
1401 | { | |
1402 | edge te, fe; | |
1403 | ||
1404 | extract_true_false_edges_from_block (exit->src, &te, &fe); | |
1405 | te->flags = EDGE_FALSE_VALUE; | |
1406 | fe->flags = EDGE_TRUE_VALUE; | |
1407 | } | |
1408 | COND_EXPR_COND (t) = build2 (LT_EXPR, boolean_type_node, var_before, nit); | |
1409 | } | |
1410 | ||
1411 | /* Moves the exit condition of LOOP to the beginning of its header, and | |
1412 | duplicates the part of the last iteration that gets disabled to the | |
1413 | exit of the loop. NIT is the number of iterations of the loop | |
1414 | (used to initialize the variables in the duplicated part). | |
1415 | ||
1416 | TODO: the common case is that latch of the loop is empty and immediatelly | |
1417 | follows the loop exit. In this case, it would be better not to copy the | |
1418 | body of the loop, but only move the entry of the loop directly before the | |
1419 | exit check and increase the number of iterations of the loop by one. | |
a509ebb5 RL |
1420 | This may need some additional preconditioning in case NIT = ~0. |
1421 | REDUCTION_LIST describes the reductions in LOOP. */ | |
5f40b3cb ZD |
1422 | |
1423 | static void | |
a509ebb5 | 1424 | transform_to_exit_first_loop (struct loop *loop, htab_t reduction_list, tree nit) |
5f40b3cb ZD |
1425 | { |
1426 | basic_block *bbs, *nbbs, ex_bb, orig_header; | |
1427 | unsigned n; | |
1428 | bool ok; | |
1429 | edge exit = single_dom_exit (loop), hpred; | |
1430 | tree phi, nphi, cond, control, control_name, res, t, cond_stmt; | |
1431 | block_stmt_iterator bsi; | |
1432 | ||
1433 | split_block_after_labels (loop->header); | |
1434 | orig_header = single_succ (loop->header); | |
1435 | hpred = single_succ_edge (loop->header); | |
1436 | ||
1437 | cond_stmt = last_stmt (exit->src); | |
1438 | cond = COND_EXPR_COND (cond_stmt); | |
1439 | control = TREE_OPERAND (cond, 0); | |
1440 | gcc_assert (TREE_OPERAND (cond, 1) == nit); | |
1441 | ||
1442 | /* Make sure that we have phi nodes on exit for all loop header phis | |
1443 | (create_parallel_loop requires that). */ | |
1444 | for (phi = phi_nodes (loop->header); phi; phi = PHI_CHAIN (phi)) | |
1445 | { | |
1446 | res = PHI_RESULT (phi); | |
1447 | t = make_ssa_name (SSA_NAME_VAR (res), phi); | |
1448 | SET_PHI_RESULT (phi, t); | |
1449 | ||
1450 | nphi = create_phi_node (res, orig_header); | |
1451 | SSA_NAME_DEF_STMT (res) = nphi; | |
1452 | add_phi_arg (nphi, t, hpred); | |
1453 | ||
1454 | if (res == control) | |
1455 | { | |
1456 | TREE_OPERAND (cond, 0) = t; | |
1457 | update_stmt (cond_stmt); | |
1458 | control = t; | |
1459 | } | |
1460 | } | |
1461 | ||
1462 | bbs = get_loop_body_in_dom_order (loop); | |
1463 | for (n = 0; bbs[n] != exit->src; n++) | |
1464 | continue; | |
1465 | nbbs = XNEWVEC (basic_block, n); | |
1466 | ok = tree_duplicate_sese_tail (single_succ_edge (loop->header), exit, | |
1467 | bbs + 1, n, nbbs); | |
1468 | gcc_assert (ok); | |
1469 | free (bbs); | |
1470 | ex_bb = nbbs[0]; | |
1471 | free (nbbs); | |
1472 | ||
a509ebb5 RL |
1473 | /* Other than reductions, the only gimple reg that should be copied |
1474 | out of the loop is the control variable. */ | |
1475 | ||
5f40b3cb ZD |
1476 | control_name = NULL_TREE; |
1477 | for (phi = phi_nodes (ex_bb); phi; phi = PHI_CHAIN (phi)) | |
1478 | { | |
1479 | res = PHI_RESULT (phi); | |
1480 | if (!is_gimple_reg (res)) | |
1481 | continue; | |
1482 | ||
a509ebb5 RL |
1483 | /* Check if it is a part of reduction. If it is, |
1484 | keep the phi at the reduction's keep_res field. The | |
1485 | PHI_RESULT of this phi is the resulting value of the reduction | |
1486 | variable when exiting the loop. */ | |
1487 | ||
1488 | exit = single_dom_exit (loop); | |
1489 | ||
1490 | if (htab_elements (reduction_list) > 0) | |
1491 | { | |
1492 | struct reduction_info *red; | |
1493 | ||
1494 | tree val = PHI_ARG_DEF_FROM_EDGE (phi, exit); | |
1495 | ||
1496 | red = reduction_phi (reduction_list, SSA_NAME_DEF_STMT (val)); | |
1497 | if (red) | |
1498 | red->keep_res = phi; | |
1499 | } | |
1500 | else | |
1501 | gcc_assert (control_name == NULL_TREE | |
1502 | && SSA_NAME_VAR (res) == SSA_NAME_VAR (control)); | |
5f40b3cb ZD |
1503 | control_name = res; |
1504 | } | |
1505 | gcc_assert (control_name != NULL_TREE); | |
1506 | phi = SSA_NAME_DEF_STMT (control_name); | |
1507 | remove_phi_node (phi, NULL_TREE, false); | |
1508 | ||
1509 | /* Initialize the control variable to NIT. */ | |
1510 | bsi = bsi_after_labels (ex_bb); | |
1511 | t = build_gimple_modify_stmt (control_name, nit); | |
1512 | bsi_insert_before (&bsi, t, BSI_NEW_STMT); | |
1513 | SSA_NAME_DEF_STMT (control_name) = t; | |
1514 | } | |
1515 | ||
1516 | /* Create the parallel constructs for LOOP as described in gen_parallel_loop. | |
1517 | LOOP_FN and DATA are the arguments of OMP_PARALLEL. | |
1518 | NEW_DATA is the variable that should be initialized from the argument | |
1519 | of LOOP_FN. N_THREADS is the requested number of threads. Returns the | |
1520 | basic block containing OMP_PARALLEL tree. */ | |
1521 | ||
1522 | static basic_block | |
1523 | create_parallel_loop (struct loop *loop, tree loop_fn, tree data, | |
1524 | tree new_data, unsigned n_threads) | |
1525 | { | |
1526 | block_stmt_iterator bsi; | |
1527 | basic_block bb, paral_bb, for_bb, ex_bb; | |
1528 | tree t, param, res, for_stmt; | |
1529 | tree cvar, cvar_init, initvar, cvar_next, cvar_base, cond, phi, type; | |
1530 | edge exit, nexit, guard, end, e; | |
1531 | ||
1532 | /* Prepare the OMP_PARALLEL statement. */ | |
1533 | bb = loop_preheader_edge (loop)->src; | |
1534 | paral_bb = single_pred (bb); | |
1535 | bsi = bsi_last (paral_bb); | |
1536 | ||
1537 | t = build_omp_clause (OMP_CLAUSE_NUM_THREADS); | |
1538 | OMP_CLAUSE_NUM_THREADS_EXPR (t) | |
a509ebb5 RL |
1539 | = build_int_cst (integer_type_node, n_threads); |
1540 | t = build4 (OMP_PARALLEL, void_type_node, NULL_TREE, t, loop_fn, data); | |
5f40b3cb ZD |
1541 | |
1542 | bsi_insert_after (&bsi, t, BSI_NEW_STMT); | |
1543 | ||
1544 | /* Initialize NEW_DATA. */ | |
1545 | if (data) | |
1546 | { | |
1547 | bsi = bsi_after_labels (bb); | |
1548 | ||
1549 | param = make_ssa_name (DECL_ARGUMENTS (loop_fn), NULL_TREE); | |
1550 | t = build_gimple_modify_stmt (param, build_fold_addr_expr (data)); | |
1551 | bsi_insert_before (&bsi, t, BSI_SAME_STMT); | |
1552 | SSA_NAME_DEF_STMT (param) = t; | |
1553 | ||
1554 | t = build_gimple_modify_stmt (new_data, | |
a509ebb5 RL |
1555 | fold_convert (TREE_TYPE (new_data), |
1556 | param)); | |
5f40b3cb ZD |
1557 | bsi_insert_before (&bsi, t, BSI_SAME_STMT); |
1558 | SSA_NAME_DEF_STMT (new_data) = t; | |
1559 | } | |
1560 | ||
1561 | /* Emit OMP_RETURN for OMP_PARALLEL. */ | |
1562 | bb = split_loop_exit_edge (single_dom_exit (loop)); | |
1563 | bsi = bsi_last (bb); | |
1564 | bsi_insert_after (&bsi, make_node (OMP_RETURN), BSI_NEW_STMT); | |
1565 | ||
1566 | /* Extract data for OMP_FOR. */ | |
1567 | gcc_assert (loop->header == single_dom_exit (loop)->src); | |
1568 | cond = COND_EXPR_COND (last_stmt (loop->header)); | |
1569 | ||
1570 | cvar = TREE_OPERAND (cond, 0); | |
1571 | cvar_base = SSA_NAME_VAR (cvar); | |
1572 | phi = SSA_NAME_DEF_STMT (cvar); | |
1573 | cvar_init = PHI_ARG_DEF_FROM_EDGE (phi, loop_preheader_edge (loop)); | |
1574 | initvar = make_ssa_name (cvar_base, NULL_TREE); | |
1575 | SET_USE (PHI_ARG_DEF_PTR_FROM_EDGE (phi, loop_preheader_edge (loop)), | |
1576 | initvar); | |
1577 | cvar_next = PHI_ARG_DEF_FROM_EDGE (phi, loop_latch_edge (loop)); | |
1578 | ||
1579 | bsi = bsi_last (loop->latch); | |
1580 | gcc_assert (bsi_stmt (bsi) == SSA_NAME_DEF_STMT (cvar_next)); | |
1581 | bsi_remove (&bsi, true); | |
1582 | ||
1583 | /* Prepare cfg. */ | |
1584 | for_bb = split_edge (loop_preheader_edge (loop)); | |
1585 | ex_bb = split_loop_exit_edge (single_dom_exit (loop)); | |
1586 | extract_true_false_edges_from_block (loop->header, &nexit, &exit); | |
1587 | gcc_assert (exit == single_dom_exit (loop)); | |
1588 | ||
1589 | guard = make_edge (for_bb, ex_bb, 0); | |
1590 | single_succ_edge (loop->latch)->flags = 0; | |
1591 | end = make_edge (loop->latch, ex_bb, EDGE_FALLTHRU); | |
1592 | for (phi = phi_nodes (ex_bb); phi; phi = PHI_CHAIN (phi)) | |
1593 | { | |
1594 | res = PHI_RESULT (phi); | |
1595 | gcc_assert (!is_gimple_reg (phi)); | |
1596 | t = SSA_NAME_DEF_STMT (PHI_ARG_DEF_FROM_EDGE (phi, exit)); | |
1597 | add_phi_arg (phi, PHI_ARG_DEF_FROM_EDGE (t, loop_preheader_edge (loop)), | |
1598 | guard); | |
1599 | add_phi_arg (phi, PHI_ARG_DEF_FROM_EDGE (t, loop_latch_edge (loop)), | |
1600 | end); | |
1601 | } | |
1602 | e = redirect_edge_and_branch (exit, nexit->dest); | |
1603 | PENDING_STMT (e) = NULL; | |
1604 | ||
1605 | /* Emit OMP_FOR. */ | |
1606 | TREE_OPERAND (cond, 0) = cvar_base; | |
1607 | type = TREE_TYPE (cvar); | |
1608 | t = build_omp_clause (OMP_CLAUSE_SCHEDULE); | |
1609 | OMP_CLAUSE_SCHEDULE_KIND (t) = OMP_CLAUSE_SCHEDULE_STATIC; | |
1610 | ||
1611 | for_stmt = make_node (OMP_FOR); | |
1612 | TREE_TYPE (for_stmt) = void_type_node; | |
1613 | OMP_FOR_CLAUSES (for_stmt) = t; | |
1614 | OMP_FOR_INIT (for_stmt) = build_gimple_modify_stmt (initvar, cvar_init); | |
1615 | OMP_FOR_COND (for_stmt) = cond; | |
a509ebb5 RL |
1616 | OMP_FOR_INCR (for_stmt) = build_gimple_modify_stmt (cvar_base, |
1617 | build2 (PLUS_EXPR, type, | |
1618 | cvar_base, | |
1619 | build_int_cst | |
1620 | (type, 1))); | |
5f40b3cb ZD |
1621 | OMP_FOR_BODY (for_stmt) = NULL_TREE; |
1622 | OMP_FOR_PRE_BODY (for_stmt) = NULL_TREE; | |
1623 | ||
1624 | bsi = bsi_last (for_bb); | |
1625 | bsi_insert_after (&bsi, for_stmt, BSI_NEW_STMT); | |
1626 | SSA_NAME_DEF_STMT (initvar) = for_stmt; | |
1627 | ||
1628 | /* Emit OMP_CONTINUE. */ | |
1629 | bsi = bsi_last (loop->latch); | |
1630 | t = build2 (OMP_CONTINUE, void_type_node, cvar_next, cvar); | |
1631 | bsi_insert_after (&bsi, t, BSI_NEW_STMT); | |
1632 | SSA_NAME_DEF_STMT (cvar_next) = t; | |
1633 | ||
1634 | /* Emit OMP_RETURN for OMP_FOR. */ | |
1635 | bsi = bsi_last (ex_bb); | |
1636 | bsi_insert_after (&bsi, make_node (OMP_RETURN), BSI_NEW_STMT); | |
1637 | ||
1638 | return paral_bb; | |
1639 | } | |
1640 | ||
1641 | /* Generates code to execute the iterations of LOOP in N_THREADS threads in | |
a509ebb5 RL |
1642 | parallel. NITER describes number of iterations of LOOP. |
1643 | REDUCTION_LIST describes the reductions existant in the LOOP. */ | |
5f40b3cb ZD |
1644 | |
1645 | static void | |
a509ebb5 RL |
1646 | gen_parallel_loop (struct loop *loop, htab_t reduction_list, |
1647 | unsigned n_threads, struct tree_niter_desc *niter) | |
5f40b3cb ZD |
1648 | { |
1649 | struct loop *nloop; | |
1650 | tree many_iterations_cond, type, nit; | |
1651 | tree stmts, arg_struct, new_arg_struct; | |
1652 | basic_block parallel_head; | |
a509ebb5 | 1653 | struct clsn_data clsn_data; |
5f40b3cb ZD |
1654 | unsigned prob; |
1655 | ||
1656 | /* From | |
1657 | ||
1658 | --------------------------------------------------------------------- | |
1659 | loop | |
1660 | { | |
1661 | IV = phi (INIT, IV + STEP) | |
1662 | BODY1; | |
1663 | if (COND) | |
1664 | break; | |
1665 | BODY2; | |
1666 | } | |
1667 | --------------------------------------------------------------------- | |
1668 | ||
1669 | with # of iterations NITER (possibly with MAY_BE_ZERO assumption), | |
1670 | we generate the following code: | |
1671 | ||
1672 | --------------------------------------------------------------------- | |
1673 | ||
1674 | if (MAY_BE_ZERO | |
a509ebb5 RL |
1675 | || NITER < MIN_PER_THREAD * N_THREADS) |
1676 | goto original; | |
5f40b3cb ZD |
1677 | |
1678 | BODY1; | |
1679 | store all local loop-invariant variables used in body of the loop to DATA. | |
1680 | OMP_PARALLEL (OMP_CLAUSE_NUM_THREADS (N_THREADS), LOOPFN, DATA); | |
1681 | load the variables from DATA. | |
1682 | OMP_FOR (IV = INIT; COND; IV += STEP) (OMP_CLAUSE_SCHEDULE (static)) | |
1683 | BODY2; | |
1684 | BODY1; | |
1685 | OMP_CONTINUE; | |
a509ebb5 RL |
1686 | OMP_RETURN -- OMP_FOR |
1687 | OMP_RETURN -- OMP_PARALLEL | |
5f40b3cb ZD |
1688 | goto end; |
1689 | ||
1690 | original: | |
1691 | loop | |
1692 | { | |
1693 | IV = phi (INIT, IV + STEP) | |
1694 | BODY1; | |
1695 | if (COND) | |
1696 | break; | |
1697 | BODY2; | |
1698 | } | |
1699 | ||
1700 | end: | |
1701 | ||
1702 | */ | |
1703 | ||
1704 | /* Create two versions of the loop -- in the old one, we know that the | |
1705 | number of iterations is large enough, and we will transform it into the | |
1706 | loop that will be split to loop_fn, the new one will be used for the | |
1707 | remaining iterations. */ | |
a509ebb5 | 1708 | |
5f40b3cb ZD |
1709 | type = TREE_TYPE (niter->niter); |
1710 | nit = force_gimple_operand (unshare_expr (niter->niter), &stmts, true, | |
1711 | NULL_TREE); | |
1712 | if (stmts) | |
1713 | bsi_insert_on_edge_immediate (loop_preheader_edge (loop), stmts); | |
1714 | ||
1715 | many_iterations_cond = | |
a509ebb5 RL |
1716 | fold_build2 (GE_EXPR, boolean_type_node, |
1717 | nit, build_int_cst (type, MIN_PER_THREAD * n_threads)); | |
5f40b3cb | 1718 | many_iterations_cond |
a509ebb5 RL |
1719 | = fold_build2 (TRUTH_AND_EXPR, boolean_type_node, |
1720 | invert_truthvalue (unshare_expr (niter->may_be_zero)), | |
1721 | many_iterations_cond); | |
5f40b3cb | 1722 | many_iterations_cond |
a509ebb5 | 1723 | = force_gimple_operand (many_iterations_cond, &stmts, false, NULL_TREE); |
5f40b3cb ZD |
1724 | if (stmts) |
1725 | bsi_insert_on_edge_immediate (loop_preheader_edge (loop), stmts); | |
1726 | if (!is_gimple_condexpr (many_iterations_cond)) | |
1727 | { | |
1728 | many_iterations_cond | |
a509ebb5 RL |
1729 | = force_gimple_operand (many_iterations_cond, &stmts, |
1730 | true, NULL_TREE); | |
5f40b3cb ZD |
1731 | if (stmts) |
1732 | bsi_insert_on_edge_immediate (loop_preheader_edge (loop), stmts); | |
1733 | } | |
1734 | ||
1735 | initialize_original_copy_tables (); | |
1736 | ||
1737 | /* We assume that the loop usually iterates a lot. */ | |
1738 | prob = 4 * REG_BR_PROB_BASE / 5; | |
1739 | nloop = loop_version (loop, many_iterations_cond, NULL, | |
1740 | prob, prob, REG_BR_PROB_BASE - prob, true); | |
1741 | update_ssa (TODO_update_ssa); | |
1742 | free_original_copy_tables (); | |
1743 | ||
1744 | /* Base all the induction variables in LOOP on a single control one. */ | |
a509ebb5 | 1745 | canonicalize_loop_ivs (loop, reduction_list, nit); |
5f40b3cb ZD |
1746 | |
1747 | /* Ensure that the exit condition is the first statement in the loop. */ | |
a509ebb5 RL |
1748 | transform_to_exit_first_loop (loop, reduction_list, nit); |
1749 | ||
1750 | ||
1751 | /* Generate intializations for reductions. */ | |
1752 | ||
1753 | if (htab_elements (reduction_list) > 0) | |
1754 | htab_traverse (reduction_list, initialize_reductions, loop); | |
5f40b3cb ZD |
1755 | |
1756 | /* Eliminate the references to local variables from the loop. */ | |
1757 | eliminate_local_variables (loop); | |
1758 | ||
1759 | /* In the old loop, move all variables non-local to the loop to a structure | |
1760 | and back, and create separate decls for the variables used in loop. */ | |
a509ebb5 | 1761 | separate_decls_in_loop (loop, reduction_list, &arg_struct, &new_arg_struct, &clsn_data); |
5f40b3cb ZD |
1762 | |
1763 | /* Create the parallel constructs. */ | |
1764 | parallel_head = create_parallel_loop (loop, create_loop_fn (), arg_struct, | |
1765 | new_arg_struct, n_threads); | |
a509ebb5 RL |
1766 | if (htab_elements (reduction_list) > 0) |
1767 | create_call_for_reduction (loop, reduction_list, &clsn_data); | |
5f40b3cb ZD |
1768 | |
1769 | scev_reset (); | |
1770 | ||
1771 | /* Cancel the loop (it is simpler to do it here rather than to teach the | |
1772 | expander to do it). */ | |
1773 | cancel_loop_tree (loop); | |
1774 | ||
1775 | /* Expand the parallel constructs. We do it directly here instead of running | |
1776 | a separate expand_omp pass, since it is more efficient, and less likely to | |
1777 | cause troubles with further analyses not being able to deal with the | |
1778 | OMP trees. */ | |
a509ebb5 | 1779 | |
5f40b3cb ZD |
1780 | omp_expand_local (parallel_head); |
1781 | } | |
1782 | ||
1783 | /* Detect parallel loops and generate parallel code using libgomp | |
1784 | primitives. Returns true if some loop was parallelized, false | |
1785 | otherwise. */ | |
1786 | ||
1787 | bool | |
1788 | parallelize_loops (void) | |
1789 | { | |
1790 | unsigned n_threads = flag_tree_parallelize_loops; | |
1791 | bool changed = false; | |
1792 | struct loop *loop; | |
1793 | struct tree_niter_desc niter_desc; | |
1794 | loop_iterator li; | |
a509ebb5 | 1795 | htab_t reduction_list; |
5f40b3cb ZD |
1796 | |
1797 | /* Do not parallelize loops in the functions created by parallelization. */ | |
1798 | if (parallelized_function_p (cfun->decl)) | |
1799 | return false; | |
1800 | ||
a509ebb5 RL |
1801 | reduction_list = htab_create (10, reduction_info_hash, |
1802 | reduction_info_eq, free); | |
1803 | ||
5f40b3cb ZD |
1804 | FOR_EACH_LOOP (li, loop, 0) |
1805 | { | |
a509ebb5 | 1806 | htab_empty (reduction_list); |
5f40b3cb ZD |
1807 | if (/* Do not bother with loops in cold areas. */ |
1808 | !maybe_hot_bb_p (loop->header) | |
1809 | /* Or loops that roll too little. */ | |
1810 | || expected_loop_iterations (loop) <= n_threads | |
1811 | /* And of course, the loop must be parallelizable. */ | |
1812 | || !can_duplicate_loop_p (loop) | |
a509ebb5 | 1813 | || !loop_parallel_p (loop, reduction_list, &niter_desc)) |
5f40b3cb ZD |
1814 | continue; |
1815 | ||
1816 | changed = true; | |
a509ebb5 | 1817 | gen_parallel_loop (loop, reduction_list, n_threads, &niter_desc); |
5f40b3cb ZD |
1818 | verify_flow_info (); |
1819 | verify_dominators (CDI_DOMINATORS); | |
1820 | verify_loop_structure (); | |
1821 | verify_loop_closed_ssa (); | |
1822 | } | |
1823 | ||
a509ebb5 | 1824 | htab_delete (reduction_list); |
5f40b3cb ZD |
1825 | return changed; |
1826 | } | |
1827 | ||
1828 | #include "gt-tree-parloops.h" |