Daily bump.
[official-gcc.git] / gcc / tree-parloops.c
blob5e64d5ed7a38d95126cb17535ab7f0bb3b1a2ad4
1 /* Loop autoparallelization.
2 Copyright (C) 2006-2021 Free Software Foundation, Inc.
3 Contributed by Sebastian Pop <pop@cri.ensmp.fr>
4 Zdenek Dvorak <dvorakz@suse.cz> and Razya Ladelsky <razya@il.ibm.com>.
6 This file is part of GCC.
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 3, or (at your option) any later
11 version.
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.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
22 #include "config.h"
23 #include "system.h"
24 #include "coretypes.h"
25 #include "backend.h"
26 #include "tree.h"
27 #include "gimple.h"
28 #include "cfghooks.h"
29 #include "tree-pass.h"
30 #include "ssa.h"
31 #include "cgraph.h"
32 #include "gimple-pretty-print.h"
33 #include "fold-const.h"
34 #include "gimplify.h"
35 #include "gimple-iterator.h"
36 #include "gimplify-me.h"
37 #include "gimple-walk.h"
38 #include "stor-layout.h"
39 #include "tree-nested.h"
40 #include "tree-cfg.h"
41 #include "tree-ssa-loop-ivopts.h"
42 #include "tree-ssa-loop-manip.h"
43 #include "tree-ssa-loop-niter.h"
44 #include "tree-ssa-loop.h"
45 #include "tree-into-ssa.h"
46 #include "cfgloop.h"
47 #include "tree-scalar-evolution.h"
48 #include "langhooks.h"
49 #include "tree-vectorizer.h"
50 #include "tree-hasher.h"
51 #include "tree-parloops.h"
52 #include "omp-general.h"
53 #include "omp-low.h"
54 #include "tree-ssa.h"
55 #include "tree-ssa-alias.h"
56 #include "tree-eh.h"
57 #include "gomp-constants.h"
58 #include "tree-dfa.h"
59 #include "stringpool.h"
60 #include "attribs.h"
62 /* This pass tries to distribute iterations of loops into several threads.
63 The implementation is straightforward -- for each loop we test whether its
64 iterations are independent, and if it is the case (and some additional
65 conditions regarding profitability and correctness are satisfied), we
66 add GIMPLE_OMP_PARALLEL and GIMPLE_OMP_FOR codes and let omp expansion
67 machinery do its job.
69 The most of the complexity is in bringing the code into shape expected
70 by the omp expanders:
71 -- for GIMPLE_OMP_FOR, ensuring that the loop has only one induction
72 variable and that the exit test is at the start of the loop body
73 -- for GIMPLE_OMP_PARALLEL, replacing the references to local addressable
74 variables by accesses through pointers, and breaking up ssa chains
75 by storing the values incoming to the parallelized loop to a structure
76 passed to the new function as an argument (something similar is done
77 in omp gimplification, unfortunately only a small part of the code
78 can be shared).
80 TODO:
81 -- if there are several parallelizable loops in a function, it may be
82 possible to generate the threads just once (using synchronization to
83 ensure that cross-loop dependences are obeyed).
84 -- handling of common reduction patterns for outer loops.
86 More info can also be found at http://gcc.gnu.org/wiki/AutoParInGCC */
88 Reduction handling:
89 currently we use code inspired by vect_force_simple_reduction to detect
90 reduction patterns.
91 The code transformation will be introduced by an example.
94 parloop
96 int sum=1;
98 for (i = 0; i < N; i++)
100 x[i] = i + 3;
101 sum+=x[i];
105 gimple-like code:
106 header_bb:
108 # sum_29 = PHI <sum_11(5), 1(3)>
109 # i_28 = PHI <i_12(5), 0(3)>
110 D.1795_8 = i_28 + 3;
111 x[i_28] = D.1795_8;
112 sum_11 = D.1795_8 + sum_29;
113 i_12 = i_28 + 1;
114 if (N_6(D) > i_12)
115 goto header_bb;
118 exit_bb:
120 # sum_21 = PHI <sum_11(4)>
121 printf (&"%d"[0], sum_21);
124 after reduction transformation (only relevant parts):
126 parloop
129 ....
132 # Storing the initial value given by the user. #
134 .paral_data_store.32.sum.27 = 1;
136 #pragma omp parallel num_threads(4)
138 #pragma omp for schedule(static)
140 # The neutral element corresponding to the particular
141 reduction's operation, e.g. 0 for PLUS_EXPR,
142 1 for MULT_EXPR, etc. replaces the user's initial value. #
144 # sum.27_29 = PHI <sum.27_11, 0>
146 sum.27_11 = D.1827_8 + sum.27_29;
148 GIMPLE_OMP_CONTINUE
150 # Adding this reduction phi is done at create_phi_for_local_result() #
151 # sum.27_56 = PHI <sum.27_11, 0>
152 GIMPLE_OMP_RETURN
154 # Creating the atomic operation is done at
155 create_call_for_reduction_1() #
157 #pragma omp atomic_load
158 D.1839_59 = *&.paral_data_load.33_51->reduction.23;
159 D.1840_60 = sum.27_56 + D.1839_59;
160 #pragma omp atomic_store (D.1840_60);
162 GIMPLE_OMP_RETURN
164 # collecting the result after the join of the threads is done at
165 create_loads_for_reductions().
166 The value computed by the threads is loaded from the
167 shared struct. #
170 .paral_data_load.33_52 = &.paral_data_store.32;
171 sum_37 = .paral_data_load.33_52->sum.27;
172 sum_43 = D.1795_41 + sum_37;
174 exit bb:
175 # sum_21 = PHI <sum_43, sum_26>
176 printf (&"%d"[0], sum_21);
184 /* Error reporting helper for parloops_is_simple_reduction below. GIMPLE
185 statement STMT is printed with a message MSG. */
187 static void
188 report_ploop_op (dump_flags_t msg_type, gimple *stmt, const char *msg)
190 dump_printf_loc (msg_type, vect_location, "%s%G", msg, stmt);
193 /* DEF_STMT_INFO occurs in a loop that contains a potential reduction
194 operation. Return true if the results of DEF_STMT_INFO are something
195 that can be accumulated by such a reduction. */
197 static bool
198 parloops_valid_reduction_input_p (stmt_vec_info def_stmt_info)
200 return (is_gimple_assign (def_stmt_info->stmt)
201 || is_gimple_call (def_stmt_info->stmt)
202 || STMT_VINFO_DEF_TYPE (def_stmt_info) == vect_induction_def
203 || (gimple_code (def_stmt_info->stmt) == GIMPLE_PHI
204 && STMT_VINFO_DEF_TYPE (def_stmt_info) == vect_internal_def
205 && !is_loop_header_bb_p (gimple_bb (def_stmt_info->stmt))));
208 /* Detect SLP reduction of the form:
210 #a1 = phi <a5, a0>
211 a2 = operation (a1)
212 a3 = operation (a2)
213 a4 = operation (a3)
214 a5 = operation (a4)
216 #a = phi <a5>
218 PHI is the reduction phi node (#a1 = phi <a5, a0> above)
219 FIRST_STMT is the first reduction stmt in the chain
220 (a2 = operation (a1)).
222 Return TRUE if a reduction chain was detected. */
224 static bool
225 parloops_is_slp_reduction (loop_vec_info loop_info, gimple *phi,
226 gimple *first_stmt)
228 class loop *loop = (gimple_bb (phi))->loop_father;
229 class loop *vect_loop = LOOP_VINFO_LOOP (loop_info);
230 enum tree_code code;
231 gimple *loop_use_stmt = NULL;
232 stmt_vec_info use_stmt_info;
233 tree lhs;
234 imm_use_iterator imm_iter;
235 use_operand_p use_p;
236 int nloop_uses, size = 0, n_out_of_loop_uses;
237 bool found = false;
239 if (loop != vect_loop)
240 return false;
242 auto_vec<stmt_vec_info, 8> reduc_chain;
243 lhs = PHI_RESULT (phi);
244 code = gimple_assign_rhs_code (first_stmt);
245 while (1)
247 nloop_uses = 0;
248 n_out_of_loop_uses = 0;
249 FOR_EACH_IMM_USE_FAST (use_p, imm_iter, lhs)
251 gimple *use_stmt = USE_STMT (use_p);
252 if (is_gimple_debug (use_stmt))
253 continue;
255 /* Check if we got back to the reduction phi. */
256 if (use_stmt == phi)
258 loop_use_stmt = use_stmt;
259 found = true;
260 break;
263 if (flow_bb_inside_loop_p (loop, gimple_bb (use_stmt)))
265 loop_use_stmt = use_stmt;
266 nloop_uses++;
268 else
269 n_out_of_loop_uses++;
271 /* There are can be either a single use in the loop or two uses in
272 phi nodes. */
273 if (nloop_uses > 1 || (n_out_of_loop_uses && nloop_uses))
274 return false;
277 if (found)
278 break;
280 /* We reached a statement with no loop uses. */
281 if (nloop_uses == 0)
282 return false;
284 /* This is a loop exit phi, and we haven't reached the reduction phi. */
285 if (gimple_code (loop_use_stmt) == GIMPLE_PHI)
286 return false;
288 if (!is_gimple_assign (loop_use_stmt)
289 || code != gimple_assign_rhs_code (loop_use_stmt)
290 || !flow_bb_inside_loop_p (loop, gimple_bb (loop_use_stmt)))
291 return false;
293 /* Insert USE_STMT into reduction chain. */
294 use_stmt_info = loop_info->lookup_stmt (loop_use_stmt);
295 reduc_chain.safe_push (use_stmt_info);
297 lhs = gimple_assign_lhs (loop_use_stmt);
298 size++;
301 if (!found || loop_use_stmt != phi || size < 2)
302 return false;
304 /* Swap the operands, if needed, to make the reduction operand be the second
305 operand. */
306 lhs = PHI_RESULT (phi);
307 for (unsigned i = 0; i < reduc_chain.length (); ++i)
309 gassign *next_stmt = as_a <gassign *> (reduc_chain[i]->stmt);
310 if (gimple_assign_rhs2 (next_stmt) == lhs)
312 tree op = gimple_assign_rhs1 (next_stmt);
313 stmt_vec_info def_stmt_info = loop_info->lookup_def (op);
315 /* Check that the other def is either defined in the loop
316 ("vect_internal_def"), or it's an induction (defined by a
317 loop-header phi-node). */
318 if (def_stmt_info
319 && flow_bb_inside_loop_p (loop, gimple_bb (def_stmt_info->stmt))
320 && parloops_valid_reduction_input_p (def_stmt_info))
322 lhs = gimple_assign_lhs (next_stmt);
323 continue;
326 return false;
328 else
330 tree op = gimple_assign_rhs2 (next_stmt);
331 stmt_vec_info def_stmt_info = loop_info->lookup_def (op);
333 /* Check that the other def is either defined in the loop
334 ("vect_internal_def"), or it's an induction (defined by a
335 loop-header phi-node). */
336 if (def_stmt_info
337 && flow_bb_inside_loop_p (loop, gimple_bb (def_stmt_info->stmt))
338 && parloops_valid_reduction_input_p (def_stmt_info))
340 if (dump_enabled_p ())
341 dump_printf_loc (MSG_NOTE, vect_location, "swapping oprnds: %G",
342 next_stmt);
344 swap_ssa_operands (next_stmt,
345 gimple_assign_rhs1_ptr (next_stmt),
346 gimple_assign_rhs2_ptr (next_stmt));
347 update_stmt (next_stmt);
349 else
350 return false;
353 lhs = gimple_assign_lhs (next_stmt);
356 /* Build up the actual chain. */
357 for (unsigned i = 0; i < reduc_chain.length () - 1; ++i)
359 REDUC_GROUP_FIRST_ELEMENT (reduc_chain[i]) = reduc_chain[0];
360 REDUC_GROUP_NEXT_ELEMENT (reduc_chain[i]) = reduc_chain[i+1];
362 REDUC_GROUP_FIRST_ELEMENT (reduc_chain.last ()) = reduc_chain[0];
363 REDUC_GROUP_NEXT_ELEMENT (reduc_chain.last ()) = NULL;
365 /* Save the chain for further analysis in SLP detection. */
366 LOOP_VINFO_REDUCTION_CHAINS (loop_info).safe_push (reduc_chain[0]);
367 REDUC_GROUP_SIZE (reduc_chain[0]) = size;
369 return true;
372 /* Return true if we need an in-order reduction for operation CODE
373 on type TYPE. NEED_WRAPPING_INTEGRAL_OVERFLOW is true if integer
374 overflow must wrap. */
376 static bool
377 parloops_needs_fold_left_reduction_p (tree type, tree_code code,
378 bool need_wrapping_integral_overflow)
380 /* CHECKME: check for !flag_finite_math_only too? */
381 if (SCALAR_FLOAT_TYPE_P (type))
382 switch (code)
384 case MIN_EXPR:
385 case MAX_EXPR:
386 return false;
388 default:
389 return !flag_associative_math;
392 if (INTEGRAL_TYPE_P (type))
394 if (!operation_no_trapping_overflow (type, code))
395 return true;
396 if (need_wrapping_integral_overflow
397 && !TYPE_OVERFLOW_WRAPS (type)
398 && operation_can_overflow (code))
399 return true;
400 return false;
403 if (SAT_FIXED_POINT_TYPE_P (type))
404 return true;
406 return false;
410 /* Function parloops_is_simple_reduction
412 (1) Detect a cross-iteration def-use cycle that represents a simple
413 reduction computation. We look for the following pattern:
415 loop_header:
416 a1 = phi < a0, a2 >
417 a3 = ...
418 a2 = operation (a3, a1)
422 a3 = ...
423 loop_header:
424 a1 = phi < a0, a2 >
425 a2 = operation (a3, a1)
427 such that:
428 1. operation is commutative and associative and it is safe to
429 change the order of the computation
430 2. no uses for a2 in the loop (a2 is used out of the loop)
431 3. no uses of a1 in the loop besides the reduction operation
432 4. no uses of a1 outside the loop.
434 Conditions 1,4 are tested here.
435 Conditions 2,3 are tested in vect_mark_stmts_to_be_vectorized.
437 (2) Detect a cross-iteration def-use cycle in nested loops, i.e.,
438 nested cycles.
440 (3) Detect cycles of phi nodes in outer-loop vectorization, i.e., double
441 reductions:
443 a1 = phi < a0, a2 >
444 inner loop (def of a3)
445 a2 = phi < a3 >
447 (4) Detect condition expressions, ie:
448 for (int i = 0; i < N; i++)
449 if (a[i] < val)
450 ret_val = a[i];
454 static stmt_vec_info
455 parloops_is_simple_reduction (loop_vec_info loop_info, stmt_vec_info phi_info,
456 bool *double_reduc,
457 bool need_wrapping_integral_overflow,
458 enum vect_reduction_type *v_reduc_type)
460 gphi *phi = as_a <gphi *> (phi_info->stmt);
461 class loop *loop = (gimple_bb (phi))->loop_father;
462 class loop *vect_loop = LOOP_VINFO_LOOP (loop_info);
463 bool nested_in_vect_loop = flow_loop_nested_p (vect_loop, loop);
464 gimple *phi_use_stmt = NULL;
465 enum tree_code orig_code, code;
466 tree op1, op2, op3 = NULL_TREE, op4 = NULL_TREE;
467 tree type;
468 tree name;
469 imm_use_iterator imm_iter;
470 use_operand_p use_p;
471 bool phi_def;
473 *double_reduc = false;
474 *v_reduc_type = TREE_CODE_REDUCTION;
476 tree phi_name = PHI_RESULT (phi);
477 /* ??? If there are no uses of the PHI result the inner loop reduction
478 won't be detected as possibly double-reduction by vectorizable_reduction
479 because that tries to walk the PHI arg from the preheader edge which
480 can be constant. See PR60382. */
481 if (has_zero_uses (phi_name))
482 return NULL;
483 unsigned nphi_def_loop_uses = 0;
484 FOR_EACH_IMM_USE_FAST (use_p, imm_iter, phi_name)
486 gimple *use_stmt = USE_STMT (use_p);
487 if (is_gimple_debug (use_stmt))
488 continue;
490 if (!flow_bb_inside_loop_p (loop, gimple_bb (use_stmt)))
492 if (dump_enabled_p ())
493 dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
494 "intermediate value used outside loop.\n");
496 return NULL;
499 nphi_def_loop_uses++;
500 phi_use_stmt = use_stmt;
503 edge latch_e = loop_latch_edge (loop);
504 tree loop_arg = PHI_ARG_DEF_FROM_EDGE (phi, latch_e);
505 if (TREE_CODE (loop_arg) != SSA_NAME)
507 if (dump_enabled_p ())
508 dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
509 "reduction: not ssa_name: %T\n", loop_arg);
510 return NULL;
513 stmt_vec_info def_stmt_info = loop_info->lookup_def (loop_arg);
514 if (!def_stmt_info
515 || !flow_bb_inside_loop_p (loop, gimple_bb (def_stmt_info->stmt)))
516 return NULL;
518 if (gassign *def_stmt = dyn_cast <gassign *> (def_stmt_info->stmt))
520 name = gimple_assign_lhs (def_stmt);
521 phi_def = false;
523 else if (gphi *def_stmt = dyn_cast <gphi *> (def_stmt_info->stmt))
525 name = PHI_RESULT (def_stmt);
526 phi_def = true;
528 else
530 if (dump_enabled_p ())
531 dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
532 "reduction: unhandled reduction operation: %G",
533 def_stmt_info->stmt);
534 return NULL;
537 unsigned nlatch_def_loop_uses = 0;
538 auto_vec<gphi *, 3> lcphis;
539 bool inner_loop_of_double_reduc = false;
540 FOR_EACH_IMM_USE_FAST (use_p, imm_iter, name)
542 gimple *use_stmt = USE_STMT (use_p);
543 if (is_gimple_debug (use_stmt))
544 continue;
545 if (flow_bb_inside_loop_p (loop, gimple_bb (use_stmt)))
546 nlatch_def_loop_uses++;
547 else
549 /* We can have more than one loop-closed PHI. */
550 lcphis.safe_push (as_a <gphi *> (use_stmt));
551 if (nested_in_vect_loop
552 && (STMT_VINFO_DEF_TYPE (loop_info->lookup_stmt (use_stmt))
553 == vect_double_reduction_def))
554 inner_loop_of_double_reduc = true;
558 /* If this isn't a nested cycle or if the nested cycle reduction value
559 is used ouside of the inner loop we cannot handle uses of the reduction
560 value. */
561 if ((!nested_in_vect_loop || inner_loop_of_double_reduc)
562 && (nlatch_def_loop_uses > 1 || nphi_def_loop_uses > 1))
564 if (dump_enabled_p ())
565 dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
566 "reduction used in loop.\n");
567 return NULL;
570 /* If DEF_STMT is a phi node itself, we expect it to have a single argument
571 defined in the inner loop. */
572 if (phi_def)
574 gphi *def_stmt = as_a <gphi *> (def_stmt_info->stmt);
575 op1 = PHI_ARG_DEF (def_stmt, 0);
577 if (gimple_phi_num_args (def_stmt) != 1
578 || TREE_CODE (op1) != SSA_NAME)
580 if (dump_enabled_p ())
581 dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
582 "unsupported phi node definition.\n");
584 return NULL;
587 gimple *def1 = SSA_NAME_DEF_STMT (op1);
588 if (gimple_bb (def1)
589 && flow_bb_inside_loop_p (loop, gimple_bb (def_stmt))
590 && loop->inner
591 && flow_bb_inside_loop_p (loop->inner, gimple_bb (def1))
592 && is_gimple_assign (def1)
593 && is_a <gphi *> (phi_use_stmt)
594 && flow_bb_inside_loop_p (loop->inner, gimple_bb (phi_use_stmt)))
596 if (dump_enabled_p ())
597 report_ploop_op (MSG_NOTE, def_stmt,
598 "detected double reduction: ");
600 *double_reduc = true;
601 return def_stmt_info;
604 return NULL;
607 /* If we are vectorizing an inner reduction we are executing that
608 in the original order only in case we are not dealing with a
609 double reduction. */
610 bool check_reduction = true;
611 if (flow_loop_nested_p (vect_loop, loop))
613 gphi *lcphi;
614 unsigned i;
615 check_reduction = false;
616 FOR_EACH_VEC_ELT (lcphis, i, lcphi)
617 FOR_EACH_IMM_USE_FAST (use_p, imm_iter, gimple_phi_result (lcphi))
619 gimple *use_stmt = USE_STMT (use_p);
620 if (is_gimple_debug (use_stmt))
621 continue;
622 if (! flow_bb_inside_loop_p (vect_loop, gimple_bb (use_stmt)))
623 check_reduction = true;
627 gassign *def_stmt = as_a <gassign *> (def_stmt_info->stmt);
628 code = orig_code = gimple_assign_rhs_code (def_stmt);
630 if (nested_in_vect_loop && !check_reduction)
632 /* FIXME: Even for non-reductions code generation is funneled
633 through vectorizable_reduction for the stmt defining the
634 PHI latch value. So we have to artificially restrict ourselves
635 for the supported operations. */
636 switch (get_gimple_rhs_class (code))
638 case GIMPLE_BINARY_RHS:
639 case GIMPLE_TERNARY_RHS:
640 break;
641 default:
642 /* Not supported by vectorizable_reduction. */
643 if (dump_enabled_p ())
644 report_ploop_op (MSG_MISSED_OPTIMIZATION, def_stmt,
645 "nested cycle: not handled operation: ");
646 return NULL;
648 if (dump_enabled_p ())
649 report_ploop_op (MSG_NOTE, def_stmt, "detected nested cycle: ");
650 return def_stmt_info;
653 /* We can handle "res -= x[i]", which is non-associative by
654 simply rewriting this into "res += -x[i]". Avoid changing
655 gimple instruction for the first simple tests and only do this
656 if we're allowed to change code at all. */
657 if (code == MINUS_EXPR && gimple_assign_rhs2 (def_stmt) != phi_name)
658 code = PLUS_EXPR;
660 if (code == COND_EXPR)
662 if (! nested_in_vect_loop)
663 *v_reduc_type = COND_REDUCTION;
665 op3 = gimple_assign_rhs1 (def_stmt);
666 if (COMPARISON_CLASS_P (op3))
668 op4 = TREE_OPERAND (op3, 1);
669 op3 = TREE_OPERAND (op3, 0);
671 if (op3 == phi_name || op4 == phi_name)
673 if (dump_enabled_p ())
674 report_ploop_op (MSG_MISSED_OPTIMIZATION, def_stmt,
675 "reduction: condition depends on previous"
676 " iteration: ");
677 return NULL;
680 op1 = gimple_assign_rhs2 (def_stmt);
681 op2 = gimple_assign_rhs3 (def_stmt);
683 else if (!commutative_tree_code (code) || !associative_tree_code (code))
685 if (dump_enabled_p ())
686 report_ploop_op (MSG_MISSED_OPTIMIZATION, def_stmt,
687 "reduction: not commutative/associative: ");
688 return NULL;
690 else if (get_gimple_rhs_class (code) == GIMPLE_BINARY_RHS)
692 op1 = gimple_assign_rhs1 (def_stmt);
693 op2 = gimple_assign_rhs2 (def_stmt);
695 else
697 if (dump_enabled_p ())
698 report_ploop_op (MSG_MISSED_OPTIMIZATION, def_stmt,
699 "reduction: not handled operation: ");
700 return NULL;
703 if (TREE_CODE (op1) != SSA_NAME && TREE_CODE (op2) != SSA_NAME)
705 if (dump_enabled_p ())
706 report_ploop_op (MSG_MISSED_OPTIMIZATION, def_stmt,
707 "reduction: both uses not ssa_names: ");
709 return NULL;
712 type = TREE_TYPE (gimple_assign_lhs (def_stmt));
713 if ((TREE_CODE (op1) == SSA_NAME
714 && !types_compatible_p (type,TREE_TYPE (op1)))
715 || (TREE_CODE (op2) == SSA_NAME
716 && !types_compatible_p (type, TREE_TYPE (op2)))
717 || (op3 && TREE_CODE (op3) == SSA_NAME
718 && !types_compatible_p (type, TREE_TYPE (op3)))
719 || (op4 && TREE_CODE (op4) == SSA_NAME
720 && !types_compatible_p (type, TREE_TYPE (op4))))
722 if (dump_enabled_p ())
724 dump_printf_loc (MSG_NOTE, vect_location,
725 "reduction: multiple types: operation type: "
726 "%T, operands types: %T,%T",
727 type, TREE_TYPE (op1), TREE_TYPE (op2));
728 if (op3)
729 dump_printf (MSG_NOTE, ",%T", TREE_TYPE (op3));
731 if (op4)
732 dump_printf (MSG_NOTE, ",%T", TREE_TYPE (op4));
733 dump_printf (MSG_NOTE, "\n");
736 return NULL;
739 /* Check whether it's ok to change the order of the computation.
740 Generally, when vectorizing a reduction we change the order of the
741 computation. This may change the behavior of the program in some
742 cases, so we need to check that this is ok. One exception is when
743 vectorizing an outer-loop: the inner-loop is executed sequentially,
744 and therefore vectorizing reductions in the inner-loop during
745 outer-loop vectorization is safe. */
746 if (check_reduction
747 && *v_reduc_type == TREE_CODE_REDUCTION
748 && parloops_needs_fold_left_reduction_p (type, code,
749 need_wrapping_integral_overflow))
750 *v_reduc_type = FOLD_LEFT_REDUCTION;
752 /* Reduction is safe. We're dealing with one of the following:
753 1) integer arithmetic and no trapv
754 2) floating point arithmetic, and special flags permit this optimization
755 3) nested cycle (i.e., outer loop vectorization). */
756 stmt_vec_info def1_info = loop_info->lookup_def (op1);
757 stmt_vec_info def2_info = loop_info->lookup_def (op2);
758 if (code != COND_EXPR && !def1_info && !def2_info)
760 if (dump_enabled_p ())
761 report_ploop_op (MSG_NOTE, def_stmt,
762 "reduction: no defs for operands: ");
763 return NULL;
766 /* Check that one def is the reduction def, defined by PHI,
767 the other def is either defined in the loop ("vect_internal_def"),
768 or it's an induction (defined by a loop-header phi-node). */
770 if (def2_info
771 && def2_info->stmt == phi
772 && (code == COND_EXPR
773 || !def1_info
774 || !flow_bb_inside_loop_p (loop, gimple_bb (def1_info->stmt))
775 || parloops_valid_reduction_input_p (def1_info)))
777 if (dump_enabled_p ())
778 report_ploop_op (MSG_NOTE, def_stmt, "detected reduction: ");
779 return def_stmt_info;
782 if (def1_info
783 && def1_info->stmt == phi
784 && (code == COND_EXPR
785 || !def2_info
786 || !flow_bb_inside_loop_p (loop, gimple_bb (def2_info->stmt))
787 || parloops_valid_reduction_input_p (def2_info)))
789 if (! nested_in_vect_loop && orig_code != MINUS_EXPR)
791 /* Check if we can swap operands (just for simplicity - so that
792 the rest of the code can assume that the reduction variable
793 is always the last (second) argument). */
794 if (code == COND_EXPR)
796 /* Swap cond_expr by inverting the condition. */
797 tree cond_expr = gimple_assign_rhs1 (def_stmt);
798 enum tree_code invert_code = ERROR_MARK;
799 enum tree_code cond_code = TREE_CODE (cond_expr);
801 if (TREE_CODE_CLASS (cond_code) == tcc_comparison)
803 bool honor_nans = HONOR_NANS (TREE_OPERAND (cond_expr, 0));
804 invert_code = invert_tree_comparison (cond_code, honor_nans);
806 if (invert_code != ERROR_MARK)
808 TREE_SET_CODE (cond_expr, invert_code);
809 swap_ssa_operands (def_stmt,
810 gimple_assign_rhs2_ptr (def_stmt),
811 gimple_assign_rhs3_ptr (def_stmt));
813 else
815 if (dump_enabled_p ())
816 report_ploop_op (MSG_NOTE, def_stmt,
817 "detected reduction: cannot swap operands "
818 "for cond_expr");
819 return NULL;
822 else
823 swap_ssa_operands (def_stmt, gimple_assign_rhs1_ptr (def_stmt),
824 gimple_assign_rhs2_ptr (def_stmt));
826 if (dump_enabled_p ())
827 report_ploop_op (MSG_NOTE, def_stmt,
828 "detected reduction: need to swap operands: ");
830 else
832 if (dump_enabled_p ())
833 report_ploop_op (MSG_NOTE, def_stmt, "detected reduction: ");
836 return def_stmt_info;
839 /* Try to find SLP reduction chain. */
840 if (! nested_in_vect_loop
841 && code != COND_EXPR
842 && orig_code != MINUS_EXPR
843 && parloops_is_slp_reduction (loop_info, phi, def_stmt))
845 if (dump_enabled_p ())
846 report_ploop_op (MSG_NOTE, def_stmt,
847 "reduction: detected reduction chain: ");
849 return def_stmt_info;
852 /* Look for the expression computing loop_arg from loop PHI result. */
853 if (check_reduction_path (vect_location, loop, phi, loop_arg, code))
854 return def_stmt_info;
856 if (dump_enabled_p ())
858 report_ploop_op (MSG_MISSED_OPTIMIZATION, def_stmt,
859 "reduction: unknown pattern: ");
862 return NULL;
865 /* Wrapper around vect_is_simple_reduction, which will modify code
866 in-place if it enables detection of more reductions. Arguments
867 as there. */
869 stmt_vec_info
870 parloops_force_simple_reduction (loop_vec_info loop_info, stmt_vec_info phi_info,
871 bool *double_reduc,
872 bool need_wrapping_integral_overflow)
874 enum vect_reduction_type v_reduc_type;
875 stmt_vec_info def_info
876 = parloops_is_simple_reduction (loop_info, phi_info, double_reduc,
877 need_wrapping_integral_overflow,
878 &v_reduc_type);
879 if (def_info)
881 STMT_VINFO_REDUC_TYPE (phi_info) = v_reduc_type;
882 STMT_VINFO_REDUC_DEF (phi_info) = def_info;
883 STMT_VINFO_REDUC_TYPE (def_info) = v_reduc_type;
884 STMT_VINFO_REDUC_DEF (def_info) = phi_info;
886 return def_info;
889 /* Minimal number of iterations of a loop that should be executed in each
890 thread. */
891 #define MIN_PER_THREAD param_parloops_min_per_thread
893 /* Element of the hashtable, representing a
894 reduction in the current loop. */
895 struct reduction_info
897 gimple *reduc_stmt; /* reduction statement. */
898 gimple *reduc_phi; /* The phi node defining the reduction. */
899 enum tree_code reduction_code;/* code for the reduction operation. */
900 unsigned reduc_version; /* SSA_NAME_VERSION of original reduc_phi
901 result. */
902 gphi *keep_res; /* The PHI_RESULT of this phi is the resulting value
903 of the reduction variable when existing the loop. */
904 tree initial_value; /* The initial value of the reduction var before entering the loop. */
905 tree field; /* the name of the field in the parloop data structure intended for reduction. */
906 tree reduc_addr; /* The address of the reduction variable for
907 openacc reductions. */
908 tree init; /* reduction initialization value. */
909 gphi *new_phi; /* (helper field) Newly created phi node whose result
910 will be passed to the atomic operation. Represents
911 the local result each thread computed for the reduction
912 operation. */
915 /* Reduction info hashtable helpers. */
917 struct reduction_hasher : free_ptr_hash <reduction_info>
919 static inline hashval_t hash (const reduction_info *);
920 static inline bool equal (const reduction_info *, const reduction_info *);
923 /* Equality and hash functions for hashtab code. */
925 inline bool
926 reduction_hasher::equal (const reduction_info *a, const reduction_info *b)
928 return (a->reduc_phi == b->reduc_phi);
931 inline hashval_t
932 reduction_hasher::hash (const reduction_info *a)
934 return a->reduc_version;
937 typedef hash_table<reduction_hasher> reduction_info_table_type;
940 static struct reduction_info *
941 reduction_phi (reduction_info_table_type *reduction_list, gimple *phi)
943 struct reduction_info tmpred, *red;
945 if (reduction_list->is_empty () || phi == NULL)
946 return NULL;
948 if (gimple_uid (phi) == (unsigned int)-1
949 || gimple_uid (phi) == 0)
950 return NULL;
952 tmpred.reduc_phi = phi;
953 tmpred.reduc_version = gimple_uid (phi);
954 red = reduction_list->find (&tmpred);
955 gcc_assert (red == NULL || red->reduc_phi == phi);
957 return red;
960 /* Element of hashtable of names to copy. */
962 struct name_to_copy_elt
964 unsigned version; /* The version of the name to copy. */
965 tree new_name; /* The new name used in the copy. */
966 tree field; /* The field of the structure used to pass the
967 value. */
970 /* Name copies hashtable helpers. */
972 struct name_to_copy_hasher : free_ptr_hash <name_to_copy_elt>
974 static inline hashval_t hash (const name_to_copy_elt *);
975 static inline bool equal (const name_to_copy_elt *, const name_to_copy_elt *);
978 /* Equality and hash functions for hashtab code. */
980 inline bool
981 name_to_copy_hasher::equal (const name_to_copy_elt *a, const name_to_copy_elt *b)
983 return a->version == b->version;
986 inline hashval_t
987 name_to_copy_hasher::hash (const name_to_copy_elt *a)
989 return (hashval_t) a->version;
992 typedef hash_table<name_to_copy_hasher> name_to_copy_table_type;
994 /* A transformation matrix, which is a self-contained ROWSIZE x COLSIZE
995 matrix. Rather than use floats, we simply keep a single DENOMINATOR that
996 represents the denominator for every element in the matrix. */
997 typedef struct lambda_trans_matrix_s
999 lambda_matrix matrix;
1000 int rowsize;
1001 int colsize;
1002 int denominator;
1003 } *lambda_trans_matrix;
1004 #define LTM_MATRIX(T) ((T)->matrix)
1005 #define LTM_ROWSIZE(T) ((T)->rowsize)
1006 #define LTM_COLSIZE(T) ((T)->colsize)
1007 #define LTM_DENOMINATOR(T) ((T)->denominator)
1009 /* Allocate a new transformation matrix. */
1011 static lambda_trans_matrix
1012 lambda_trans_matrix_new (int colsize, int rowsize,
1013 struct obstack * lambda_obstack)
1015 lambda_trans_matrix ret;
1017 ret = (lambda_trans_matrix)
1018 obstack_alloc (lambda_obstack, sizeof (struct lambda_trans_matrix_s));
1019 LTM_MATRIX (ret) = lambda_matrix_new (rowsize, colsize, lambda_obstack);
1020 LTM_ROWSIZE (ret) = rowsize;
1021 LTM_COLSIZE (ret) = colsize;
1022 LTM_DENOMINATOR (ret) = 1;
1023 return ret;
1026 /* Multiply a vector VEC by a matrix MAT.
1027 MAT is an M*N matrix, and VEC is a vector with length N. The result
1028 is stored in DEST which must be a vector of length M. */
1030 static void
1031 lambda_matrix_vector_mult (lambda_matrix matrix, int m, int n,
1032 lambda_vector vec, lambda_vector dest)
1034 int i, j;
1036 lambda_vector_clear (dest, m);
1037 for (i = 0; i < m; i++)
1038 for (j = 0; j < n; j++)
1039 dest[i] += matrix[i][j] * vec[j];
1042 /* Return true if TRANS is a legal transformation matrix that respects
1043 the dependence vectors in DISTS and DIRS. The conservative answer
1044 is false.
1046 "Wolfe proves that a unimodular transformation represented by the
1047 matrix T is legal when applied to a loop nest with a set of
1048 lexicographically non-negative distance vectors RDG if and only if
1049 for each vector d in RDG, (T.d >= 0) is lexicographically positive.
1050 i.e.: if and only if it transforms the lexicographically positive
1051 distance vectors to lexicographically positive vectors. Note that
1052 a unimodular matrix must transform the zero vector (and only it) to
1053 the zero vector." S.Muchnick. */
1055 static bool
1056 lambda_transform_legal_p (lambda_trans_matrix trans,
1057 int nb_loops,
1058 vec<ddr_p> dependence_relations)
1060 unsigned int i, j;
1061 lambda_vector distres;
1062 struct data_dependence_relation *ddr;
1064 gcc_assert (LTM_COLSIZE (trans) == nb_loops
1065 && LTM_ROWSIZE (trans) == nb_loops);
1067 /* When there are no dependences, the transformation is correct. */
1068 if (dependence_relations.length () == 0)
1069 return true;
1071 ddr = dependence_relations[0];
1072 if (ddr == NULL)
1073 return true;
1075 /* When there is an unknown relation in the dependence_relations, we
1076 know that it is no worth looking at this loop nest: give up. */
1077 if (DDR_ARE_DEPENDENT (ddr) == chrec_dont_know)
1078 return false;
1080 distres = lambda_vector_new (nb_loops);
1082 /* For each distance vector in the dependence graph. */
1083 FOR_EACH_VEC_ELT (dependence_relations, i, ddr)
1085 /* Don't care about relations for which we know that there is no
1086 dependence, nor about read-read (aka. output-dependences):
1087 these data accesses can happen in any order. */
1088 if (DDR_ARE_DEPENDENT (ddr) == chrec_known
1089 || (DR_IS_READ (DDR_A (ddr)) && DR_IS_READ (DDR_B (ddr))))
1090 continue;
1092 /* Conservatively answer: "this transformation is not valid". */
1093 if (DDR_ARE_DEPENDENT (ddr) == chrec_dont_know)
1094 return false;
1096 /* If the dependence could not be captured by a distance vector,
1097 conservatively answer that the transform is not valid. */
1098 if (DDR_NUM_DIST_VECTS (ddr) == 0)
1099 return false;
1101 /* Compute trans.dist_vect */
1102 for (j = 0; j < DDR_NUM_DIST_VECTS (ddr); j++)
1104 lambda_matrix_vector_mult (LTM_MATRIX (trans), nb_loops, nb_loops,
1105 DDR_DIST_VECT (ddr, j), distres);
1107 if (!lambda_vector_lexico_pos (distres, nb_loops))
1108 return false;
1111 return true;
1114 /* Data dependency analysis. Returns true if the iterations of LOOP
1115 are independent on each other (that is, if we can execute them
1116 in parallel). */
1118 static bool
1119 loop_parallel_p (class loop *loop, struct obstack * parloop_obstack)
1121 vec<ddr_p> dependence_relations;
1122 vec<data_reference_p> datarefs;
1123 lambda_trans_matrix trans;
1124 bool ret = false;
1126 if (dump_file && (dump_flags & TDF_DETAILS))
1128 fprintf (dump_file, "Considering loop %d\n", loop->num);
1129 if (!loop->inner)
1130 fprintf (dump_file, "loop is innermost\n");
1131 else
1132 fprintf (dump_file, "loop NOT innermost\n");
1135 /* Check for problems with dependences. If the loop can be reversed,
1136 the iterations are independent. */
1137 auto_vec<loop_p, 3> loop_nest;
1138 datarefs.create (10);
1139 dependence_relations.create (100);
1140 if (! compute_data_dependences_for_loop (loop, true, &loop_nest, &datarefs,
1141 &dependence_relations))
1143 if (dump_file && (dump_flags & TDF_DETAILS))
1144 fprintf (dump_file, " FAILED: cannot analyze data dependencies\n");
1145 ret = false;
1146 goto end;
1148 if (dump_file && (dump_flags & TDF_DETAILS))
1149 dump_data_dependence_relations (dump_file, dependence_relations);
1151 trans = lambda_trans_matrix_new (1, 1, parloop_obstack);
1152 LTM_MATRIX (trans)[0][0] = -1;
1154 if (lambda_transform_legal_p (trans, 1, dependence_relations))
1156 ret = true;
1157 if (dump_file && (dump_flags & TDF_DETAILS))
1158 fprintf (dump_file, " SUCCESS: may be parallelized\n");
1160 else if (dump_file && (dump_flags & TDF_DETAILS))
1161 fprintf (dump_file,
1162 " FAILED: data dependencies exist across iterations\n");
1164 end:
1165 free_dependence_relations (dependence_relations);
1166 free_data_refs (datarefs);
1168 return ret;
1171 /* Return true when LOOP contains basic blocks marked with the
1172 BB_IRREDUCIBLE_LOOP flag. */
1174 static inline bool
1175 loop_has_blocks_with_irreducible_flag (class loop *loop)
1177 unsigned i;
1178 basic_block *bbs = get_loop_body_in_dom_order (loop);
1179 bool res = true;
1181 for (i = 0; i < loop->num_nodes; i++)
1182 if (bbs[i]->flags & BB_IRREDUCIBLE_LOOP)
1183 goto end;
1185 res = false;
1186 end:
1187 free (bbs);
1188 return res;
1191 /* Assigns the address of OBJ in TYPE to an ssa name, and returns this name.
1192 The assignment statement is placed on edge ENTRY. DECL_ADDRESS maps decls
1193 to their addresses that can be reused. The address of OBJ is known to
1194 be invariant in the whole function. Other needed statements are placed
1195 right before GSI. */
1197 static tree
1198 take_address_of (tree obj, tree type, edge entry,
1199 int_tree_htab_type *decl_address, gimple_stmt_iterator *gsi)
1201 int uid;
1202 tree *var_p, name, addr;
1203 gassign *stmt;
1204 gimple_seq stmts;
1206 /* Since the address of OBJ is invariant, the trees may be shared.
1207 Avoid rewriting unrelated parts of the code. */
1208 obj = unshare_expr (obj);
1209 for (var_p = &obj;
1210 handled_component_p (*var_p);
1211 var_p = &TREE_OPERAND (*var_p, 0))
1212 continue;
1214 /* Canonicalize the access to base on a MEM_REF. */
1215 if (DECL_P (*var_p))
1216 *var_p = build_simple_mem_ref (build_fold_addr_expr (*var_p));
1218 /* Assign a canonical SSA name to the address of the base decl used
1219 in the address and share it for all accesses and addresses based
1220 on it. */
1221 uid = DECL_UID (TREE_OPERAND (TREE_OPERAND (*var_p, 0), 0));
1222 int_tree_map elt;
1223 elt.uid = uid;
1224 int_tree_map *slot = decl_address->find_slot (elt, INSERT);
1225 if (!slot->to)
1227 if (gsi == NULL)
1228 return NULL;
1229 addr = TREE_OPERAND (*var_p, 0);
1230 const char *obj_name
1231 = get_name (TREE_OPERAND (TREE_OPERAND (*var_p, 0), 0));
1232 if (obj_name)
1233 name = make_temp_ssa_name (TREE_TYPE (addr), NULL, obj_name);
1234 else
1235 name = make_ssa_name (TREE_TYPE (addr));
1236 stmt = gimple_build_assign (name, addr);
1237 gsi_insert_on_edge_immediate (entry, stmt);
1239 slot->uid = uid;
1240 slot->to = name;
1242 else
1243 name = slot->to;
1245 /* Express the address in terms of the canonical SSA name. */
1246 TREE_OPERAND (*var_p, 0) = name;
1247 if (gsi == NULL)
1248 return build_fold_addr_expr_with_type (obj, type);
1250 name = force_gimple_operand (build_addr (obj),
1251 &stmts, true, NULL_TREE);
1252 if (!gimple_seq_empty_p (stmts))
1253 gsi_insert_seq_before (gsi, stmts, GSI_SAME_STMT);
1255 if (!useless_type_conversion_p (type, TREE_TYPE (name)))
1257 name = force_gimple_operand (fold_convert (type, name), &stmts, true,
1258 NULL_TREE);
1259 if (!gimple_seq_empty_p (stmts))
1260 gsi_insert_seq_before (gsi, stmts, GSI_SAME_STMT);
1263 return name;
1266 static tree
1267 reduc_stmt_res (gimple *stmt)
1269 return (gimple_code (stmt) == GIMPLE_PHI
1270 ? gimple_phi_result (stmt)
1271 : gimple_assign_lhs (stmt));
1274 /* Callback for htab_traverse. Create the initialization statement
1275 for reduction described in SLOT, and place it at the preheader of
1276 the loop described in DATA. */
1279 initialize_reductions (reduction_info **slot, class loop *loop)
1281 tree init;
1282 tree type, arg;
1283 edge e;
1285 struct reduction_info *const reduc = *slot;
1287 /* Create initialization in preheader:
1288 reduction_variable = initialization value of reduction. */
1290 /* In the phi node at the header, replace the argument coming
1291 from the preheader with the reduction initialization value. */
1293 /* Initialize the reduction. */
1294 type = TREE_TYPE (PHI_RESULT (reduc->reduc_phi));
1295 init = omp_reduction_init_op (gimple_location (reduc->reduc_stmt),
1296 reduc->reduction_code, type);
1297 reduc->init = init;
1299 /* Replace the argument representing the initialization value
1300 with the initialization value for the reduction (neutral
1301 element for the particular operation, e.g. 0 for PLUS_EXPR,
1302 1 for MULT_EXPR, etc).
1303 Keep the old value in a new variable "reduction_initial",
1304 that will be taken in consideration after the parallel
1305 computing is done. */
1307 e = loop_preheader_edge (loop);
1308 arg = PHI_ARG_DEF_FROM_EDGE (reduc->reduc_phi, e);
1309 /* Create new variable to hold the initial value. */
1311 SET_USE (PHI_ARG_DEF_PTR_FROM_EDGE
1312 (reduc->reduc_phi, loop_preheader_edge (loop)), init);
1313 reduc->initial_value = arg;
1314 return 1;
1317 struct elv_data
1319 struct walk_stmt_info info;
1320 edge entry;
1321 int_tree_htab_type *decl_address;
1322 gimple_stmt_iterator *gsi;
1323 bool changed;
1324 bool reset;
1327 /* Eliminates references to local variables in *TP out of the single
1328 entry single exit region starting at DTA->ENTRY.
1329 DECL_ADDRESS contains addresses of the references that had their
1330 address taken already. If the expression is changed, CHANGED is
1331 set to true. Callback for walk_tree. */
1333 static tree
1334 eliminate_local_variables_1 (tree *tp, int *walk_subtrees, void *data)
1336 struct elv_data *const dta = (struct elv_data *) data;
1337 tree t = *tp, var, addr, addr_type, type, obj;
1339 if (DECL_P (t))
1341 *walk_subtrees = 0;
1343 if (!SSA_VAR_P (t) || DECL_EXTERNAL (t))
1344 return NULL_TREE;
1346 type = TREE_TYPE (t);
1347 addr_type = build_pointer_type (type);
1348 addr = take_address_of (t, addr_type, dta->entry, dta->decl_address,
1349 dta->gsi);
1350 if (dta->gsi == NULL && addr == NULL_TREE)
1352 dta->reset = true;
1353 return NULL_TREE;
1356 *tp = build_simple_mem_ref (addr);
1358 dta->changed = true;
1359 return NULL_TREE;
1362 if (TREE_CODE (t) == ADDR_EXPR)
1364 /* ADDR_EXPR may appear in two contexts:
1365 -- as a gimple operand, when the address taken is a function invariant
1366 -- as gimple rhs, when the resulting address in not a function
1367 invariant
1368 We do not need to do anything special in the latter case (the base of
1369 the memory reference whose address is taken may be replaced in the
1370 DECL_P case). The former case is more complicated, as we need to
1371 ensure that the new address is still a gimple operand. Thus, it
1372 is not sufficient to replace just the base of the memory reference --
1373 we need to move the whole computation of the address out of the
1374 loop. */
1375 if (!is_gimple_val (t))
1376 return NULL_TREE;
1378 *walk_subtrees = 0;
1379 obj = TREE_OPERAND (t, 0);
1380 var = get_base_address (obj);
1381 if (!var || !SSA_VAR_P (var) || DECL_EXTERNAL (var))
1382 return NULL_TREE;
1384 addr_type = TREE_TYPE (t);
1385 addr = take_address_of (obj, addr_type, dta->entry, dta->decl_address,
1386 dta->gsi);
1387 if (dta->gsi == NULL && addr == NULL_TREE)
1389 dta->reset = true;
1390 return NULL_TREE;
1392 *tp = addr;
1394 dta->changed = true;
1395 return NULL_TREE;
1398 if (!EXPR_P (t))
1399 *walk_subtrees = 0;
1401 return NULL_TREE;
1404 /* Moves the references to local variables in STMT at *GSI out of the single
1405 entry single exit region starting at ENTRY. DECL_ADDRESS contains
1406 addresses of the references that had their address taken
1407 already. */
1409 static void
1410 eliminate_local_variables_stmt (edge entry, gimple_stmt_iterator *gsi,
1411 int_tree_htab_type *decl_address)
1413 struct elv_data dta;
1414 gimple *stmt = gsi_stmt (*gsi);
1416 memset (&dta.info, '\0', sizeof (dta.info));
1417 dta.entry = entry;
1418 dta.decl_address = decl_address;
1419 dta.changed = false;
1420 dta.reset = false;
1422 if (gimple_debug_bind_p (stmt))
1424 dta.gsi = NULL;
1425 walk_tree (gimple_debug_bind_get_value_ptr (stmt),
1426 eliminate_local_variables_1, &dta.info, NULL);
1427 if (dta.reset)
1429 gimple_debug_bind_reset_value (stmt);
1430 dta.changed = true;
1433 else if (gimple_clobber_p (stmt))
1435 unlink_stmt_vdef (stmt);
1436 stmt = gimple_build_nop ();
1437 gsi_replace (gsi, stmt, false);
1438 dta.changed = true;
1440 else
1442 dta.gsi = gsi;
1443 walk_gimple_op (stmt, eliminate_local_variables_1, &dta.info);
1446 if (dta.changed)
1447 update_stmt (stmt);
1450 /* Eliminates the references to local variables from the single entry
1451 single exit region between the ENTRY and EXIT edges.
1453 This includes:
1454 1) Taking address of a local variable -- these are moved out of the
1455 region (and temporary variable is created to hold the address if
1456 necessary).
1458 2) Dereferencing a local variable -- these are replaced with indirect
1459 references. */
1461 static void
1462 eliminate_local_variables (edge entry, edge exit)
1464 basic_block bb;
1465 auto_vec<basic_block, 3> body;
1466 unsigned i;
1467 gimple_stmt_iterator gsi;
1468 bool has_debug_stmt = false;
1469 int_tree_htab_type decl_address (10);
1470 basic_block entry_bb = entry->src;
1471 basic_block exit_bb = exit->dest;
1473 gather_blocks_in_sese_region (entry_bb, exit_bb, &body);
1475 FOR_EACH_VEC_ELT (body, i, bb)
1476 if (bb != entry_bb && bb != exit_bb)
1478 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
1479 if (is_gimple_debug (gsi_stmt (gsi)))
1481 if (gimple_debug_bind_p (gsi_stmt (gsi)))
1482 has_debug_stmt = true;
1484 else
1485 eliminate_local_variables_stmt (entry, &gsi, &decl_address);
1488 if (has_debug_stmt)
1489 FOR_EACH_VEC_ELT (body, i, bb)
1490 if (bb != entry_bb && bb != exit_bb)
1491 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
1492 if (gimple_debug_bind_p (gsi_stmt (gsi)))
1493 eliminate_local_variables_stmt (entry, &gsi, &decl_address);
1496 /* Returns true if expression EXPR is not defined between ENTRY and
1497 EXIT, i.e. if all its operands are defined outside of the region. */
1499 static bool
1500 expr_invariant_in_region_p (edge entry, edge exit, tree expr)
1502 basic_block entry_bb = entry->src;
1503 basic_block exit_bb = exit->dest;
1504 basic_block def_bb;
1506 if (is_gimple_min_invariant (expr))
1507 return true;
1509 if (TREE_CODE (expr) == SSA_NAME)
1511 def_bb = gimple_bb (SSA_NAME_DEF_STMT (expr));
1512 if (def_bb
1513 && dominated_by_p (CDI_DOMINATORS, def_bb, entry_bb)
1514 && !dominated_by_p (CDI_DOMINATORS, def_bb, exit_bb))
1515 return false;
1517 return true;
1520 return false;
1523 /* If COPY_NAME_P is true, creates and returns a duplicate of NAME.
1524 The copies are stored to NAME_COPIES, if NAME was already duplicated,
1525 its duplicate stored in NAME_COPIES is returned.
1527 Regardless of COPY_NAME_P, the decl used as a base of the ssa name is also
1528 duplicated, storing the copies in DECL_COPIES. */
1530 static tree
1531 separate_decls_in_region_name (tree name, name_to_copy_table_type *name_copies,
1532 int_tree_htab_type *decl_copies,
1533 bool copy_name_p)
1535 tree copy, var, var_copy;
1536 unsigned idx, uid, nuid;
1537 struct int_tree_map ielt;
1538 struct name_to_copy_elt elt, *nelt;
1539 name_to_copy_elt **slot;
1540 int_tree_map *dslot;
1542 if (TREE_CODE (name) != SSA_NAME)
1543 return name;
1545 idx = SSA_NAME_VERSION (name);
1546 elt.version = idx;
1547 slot = name_copies->find_slot_with_hash (&elt, idx,
1548 copy_name_p ? INSERT : NO_INSERT);
1549 if (slot && *slot)
1550 return (*slot)->new_name;
1552 if (copy_name_p)
1554 copy = duplicate_ssa_name (name, NULL);
1555 nelt = XNEW (struct name_to_copy_elt);
1556 nelt->version = idx;
1557 nelt->new_name = copy;
1558 nelt->field = NULL_TREE;
1559 *slot = nelt;
1561 else
1563 gcc_assert (!slot);
1564 copy = name;
1567 var = SSA_NAME_VAR (name);
1568 if (!var)
1569 return copy;
1571 uid = DECL_UID (var);
1572 ielt.uid = uid;
1573 dslot = decl_copies->find_slot_with_hash (ielt, uid, INSERT);
1574 if (!dslot->to)
1576 var_copy = create_tmp_var (TREE_TYPE (var), get_name (var));
1577 DECL_NOT_GIMPLE_REG_P (var_copy) = DECL_NOT_GIMPLE_REG_P (var);
1578 dslot->uid = uid;
1579 dslot->to = var_copy;
1581 /* Ensure that when we meet this decl next time, we won't duplicate
1582 it again. */
1583 nuid = DECL_UID (var_copy);
1584 ielt.uid = nuid;
1585 dslot = decl_copies->find_slot_with_hash (ielt, nuid, INSERT);
1586 gcc_assert (!dslot->to);
1587 dslot->uid = nuid;
1588 dslot->to = var_copy;
1590 else
1591 var_copy = dslot->to;
1593 replace_ssa_name_symbol (copy, var_copy);
1594 return copy;
1597 /* Finds the ssa names used in STMT that are defined outside the
1598 region between ENTRY and EXIT and replaces such ssa names with
1599 their duplicates. The duplicates are stored to NAME_COPIES. Base
1600 decls of all ssa names used in STMT (including those defined in
1601 LOOP) are replaced with the new temporary variables; the
1602 replacement decls are stored in DECL_COPIES. */
1604 static void
1605 separate_decls_in_region_stmt (edge entry, edge exit, gimple *stmt,
1606 name_to_copy_table_type *name_copies,
1607 int_tree_htab_type *decl_copies)
1609 use_operand_p use;
1610 def_operand_p def;
1611 ssa_op_iter oi;
1612 tree name, copy;
1613 bool copy_name_p;
1615 FOR_EACH_PHI_OR_STMT_DEF (def, stmt, oi, SSA_OP_DEF)
1617 name = DEF_FROM_PTR (def);
1618 gcc_assert (TREE_CODE (name) == SSA_NAME);
1619 copy = separate_decls_in_region_name (name, name_copies, decl_copies,
1620 false);
1621 gcc_assert (copy == name);
1624 FOR_EACH_PHI_OR_STMT_USE (use, stmt, oi, SSA_OP_USE)
1626 name = USE_FROM_PTR (use);
1627 if (TREE_CODE (name) != SSA_NAME)
1628 continue;
1630 copy_name_p = expr_invariant_in_region_p (entry, exit, name);
1631 copy = separate_decls_in_region_name (name, name_copies, decl_copies,
1632 copy_name_p);
1633 SET_USE (use, copy);
1637 /* Finds the ssa names used in STMT that are defined outside the
1638 region between ENTRY and EXIT and replaces such ssa names with
1639 their duplicates. The duplicates are stored to NAME_COPIES. Base
1640 decls of all ssa names used in STMT (including those defined in
1641 LOOP) are replaced with the new temporary variables; the
1642 replacement decls are stored in DECL_COPIES. */
1644 static bool
1645 separate_decls_in_region_debug (gimple *stmt,
1646 name_to_copy_table_type *name_copies,
1647 int_tree_htab_type *decl_copies)
1649 use_operand_p use;
1650 ssa_op_iter oi;
1651 tree var, name;
1652 struct int_tree_map ielt;
1653 struct name_to_copy_elt elt;
1654 name_to_copy_elt **slot;
1655 int_tree_map *dslot;
1657 if (gimple_debug_bind_p (stmt))
1658 var = gimple_debug_bind_get_var (stmt);
1659 else if (gimple_debug_source_bind_p (stmt))
1660 var = gimple_debug_source_bind_get_var (stmt);
1661 else
1662 return true;
1663 if (TREE_CODE (var) == DEBUG_EXPR_DECL || TREE_CODE (var) == LABEL_DECL)
1664 return true;
1665 gcc_assert (DECL_P (var) && SSA_VAR_P (var));
1666 ielt.uid = DECL_UID (var);
1667 dslot = decl_copies->find_slot_with_hash (ielt, ielt.uid, NO_INSERT);
1668 if (!dslot)
1669 return true;
1670 if (gimple_debug_bind_p (stmt))
1671 gimple_debug_bind_set_var (stmt, dslot->to);
1672 else if (gimple_debug_source_bind_p (stmt))
1673 gimple_debug_source_bind_set_var (stmt, dslot->to);
1675 FOR_EACH_PHI_OR_STMT_USE (use, stmt, oi, SSA_OP_USE)
1677 name = USE_FROM_PTR (use);
1678 if (TREE_CODE (name) != SSA_NAME)
1679 continue;
1681 elt.version = SSA_NAME_VERSION (name);
1682 slot = name_copies->find_slot_with_hash (&elt, elt.version, NO_INSERT);
1683 if (!slot)
1685 gimple_debug_bind_reset_value (stmt);
1686 update_stmt (stmt);
1687 break;
1690 SET_USE (use, (*slot)->new_name);
1693 return false;
1696 /* Callback for htab_traverse. Adds a field corresponding to the reduction
1697 specified in SLOT. The type is passed in DATA. */
1700 add_field_for_reduction (reduction_info **slot, tree type)
1703 struct reduction_info *const red = *slot;
1704 tree var = reduc_stmt_res (red->reduc_stmt);
1705 tree field = build_decl (gimple_location (red->reduc_stmt), FIELD_DECL,
1706 SSA_NAME_IDENTIFIER (var), TREE_TYPE (var));
1708 insert_field_into_struct (type, field);
1710 red->field = field;
1712 return 1;
1715 /* Callback for htab_traverse. Adds a field corresponding to a ssa name
1716 described in SLOT. The type is passed in DATA. */
1719 add_field_for_name (name_to_copy_elt **slot, tree type)
1721 struct name_to_copy_elt *const elt = *slot;
1722 tree name = ssa_name (elt->version);
1723 tree field = build_decl (UNKNOWN_LOCATION,
1724 FIELD_DECL, SSA_NAME_IDENTIFIER (name),
1725 TREE_TYPE (name));
1727 insert_field_into_struct (type, field);
1728 elt->field = field;
1730 return 1;
1733 /* Callback for htab_traverse. A local result is the intermediate result
1734 computed by a single
1735 thread, or the initial value in case no iteration was executed.
1736 This function creates a phi node reflecting these values.
1737 The phi's result will be stored in NEW_PHI field of the
1738 reduction's data structure. */
1741 create_phi_for_local_result (reduction_info **slot, class loop *loop)
1743 struct reduction_info *const reduc = *slot;
1744 edge e;
1745 gphi *new_phi;
1746 basic_block store_bb, continue_bb;
1747 tree local_res;
1748 location_t locus;
1750 /* STORE_BB is the block where the phi
1751 should be stored. It is the destination of the loop exit.
1752 (Find the fallthru edge from GIMPLE_OMP_CONTINUE). */
1753 continue_bb = single_pred (loop->latch);
1754 store_bb = FALLTHRU_EDGE (continue_bb)->dest;
1756 /* STORE_BB has two predecessors. One coming from the loop
1757 (the reduction's result is computed at the loop),
1758 and another coming from a block preceding the loop,
1759 when no iterations
1760 are executed (the initial value should be taken). */
1761 if (EDGE_PRED (store_bb, 0) == FALLTHRU_EDGE (continue_bb))
1762 e = EDGE_PRED (store_bb, 1);
1763 else
1764 e = EDGE_PRED (store_bb, 0);
1765 tree lhs = reduc_stmt_res (reduc->reduc_stmt);
1766 local_res = copy_ssa_name (lhs);
1767 locus = gimple_location (reduc->reduc_stmt);
1768 new_phi = create_phi_node (local_res, store_bb);
1769 add_phi_arg (new_phi, reduc->init, e, locus);
1770 add_phi_arg (new_phi, lhs, FALLTHRU_EDGE (continue_bb), locus);
1771 reduc->new_phi = new_phi;
1773 return 1;
1776 struct clsn_data
1778 tree store;
1779 tree load;
1781 basic_block store_bb;
1782 basic_block load_bb;
1785 /* Callback for htab_traverse. Create an atomic instruction for the
1786 reduction described in SLOT.
1787 DATA annotates the place in memory the atomic operation relates to,
1788 and the basic block it needs to be generated in. */
1791 create_call_for_reduction_1 (reduction_info **slot, struct clsn_data *clsn_data)
1793 struct reduction_info *const reduc = *slot;
1794 gimple_stmt_iterator gsi;
1795 tree type = TREE_TYPE (PHI_RESULT (reduc->reduc_phi));
1796 tree load_struct;
1797 basic_block bb;
1798 basic_block new_bb;
1799 edge e;
1800 tree t, addr, ref, x;
1801 tree tmp_load, name;
1802 gimple *load;
1804 if (reduc->reduc_addr == NULL_TREE)
1806 load_struct = build_simple_mem_ref (clsn_data->load);
1807 t = build3 (COMPONENT_REF, type, load_struct, reduc->field, NULL_TREE);
1809 addr = build_addr (t);
1811 else
1813 /* Set the address for the atomic store. */
1814 addr = reduc->reduc_addr;
1816 /* Remove the non-atomic store '*addr = sum'. */
1817 tree res = PHI_RESULT (reduc->keep_res);
1818 use_operand_p use_p;
1819 gimple *stmt;
1820 bool single_use_p = single_imm_use (res, &use_p, &stmt);
1821 gcc_assert (single_use_p);
1822 replace_uses_by (gimple_vdef (stmt),
1823 gimple_vuse (stmt));
1824 gimple_stmt_iterator gsi = gsi_for_stmt (stmt);
1825 gsi_remove (&gsi, true);
1828 /* Create phi node. */
1829 bb = clsn_data->load_bb;
1831 gsi = gsi_last_bb (bb);
1832 e = split_block (bb, gsi_stmt (gsi));
1833 new_bb = e->dest;
1835 tmp_load = create_tmp_var (TREE_TYPE (TREE_TYPE (addr)));
1836 tmp_load = make_ssa_name (tmp_load);
1837 load = gimple_build_omp_atomic_load (tmp_load, addr,
1838 OMP_MEMORY_ORDER_RELAXED);
1839 SSA_NAME_DEF_STMT (tmp_load) = load;
1840 gsi = gsi_start_bb (new_bb);
1841 gsi_insert_after (&gsi, load, GSI_NEW_STMT);
1843 e = split_block (new_bb, load);
1844 new_bb = e->dest;
1845 gsi = gsi_start_bb (new_bb);
1846 ref = tmp_load;
1847 x = fold_build2 (reduc->reduction_code,
1848 TREE_TYPE (PHI_RESULT (reduc->new_phi)), ref,
1849 PHI_RESULT (reduc->new_phi));
1851 name = force_gimple_operand_gsi (&gsi, x, true, NULL_TREE, true,
1852 GSI_CONTINUE_LINKING);
1854 gimple *store = gimple_build_omp_atomic_store (name,
1855 OMP_MEMORY_ORDER_RELAXED);
1856 gsi_insert_after (&gsi, store, GSI_NEW_STMT);
1857 return 1;
1860 /* Create the atomic operation at the join point of the threads.
1861 REDUCTION_LIST describes the reductions in the LOOP.
1862 LD_ST_DATA describes the shared data structure where
1863 shared data is stored in and loaded from. */
1864 static void
1865 create_call_for_reduction (class loop *loop,
1866 reduction_info_table_type *reduction_list,
1867 struct clsn_data *ld_st_data)
1869 reduction_list->traverse <class loop *, create_phi_for_local_result> (loop);
1870 /* Find the fallthru edge from GIMPLE_OMP_CONTINUE. */
1871 basic_block continue_bb = single_pred (loop->latch);
1872 ld_st_data->load_bb = FALLTHRU_EDGE (continue_bb)->dest;
1873 reduction_list
1874 ->traverse <struct clsn_data *, create_call_for_reduction_1> (ld_st_data);
1877 /* Callback for htab_traverse. Loads the final reduction value at the
1878 join point of all threads, and inserts it in the right place. */
1881 create_loads_for_reductions (reduction_info **slot, struct clsn_data *clsn_data)
1883 struct reduction_info *const red = *slot;
1884 gimple *stmt;
1885 gimple_stmt_iterator gsi;
1886 tree type = TREE_TYPE (reduc_stmt_res (red->reduc_stmt));
1887 tree load_struct;
1888 tree name;
1889 tree x;
1891 /* If there's no exit phi, the result of the reduction is unused. */
1892 if (red->keep_res == NULL)
1893 return 1;
1895 gsi = gsi_after_labels (clsn_data->load_bb);
1896 load_struct = build_simple_mem_ref (clsn_data->load);
1897 load_struct = build3 (COMPONENT_REF, type, load_struct, red->field,
1898 NULL_TREE);
1900 x = load_struct;
1901 name = PHI_RESULT (red->keep_res);
1902 stmt = gimple_build_assign (name, x);
1904 gsi_insert_after (&gsi, stmt, GSI_NEW_STMT);
1906 for (gsi = gsi_start_phis (gimple_bb (red->keep_res));
1907 !gsi_end_p (gsi); gsi_next (&gsi))
1908 if (gsi_stmt (gsi) == red->keep_res)
1910 remove_phi_node (&gsi, false);
1911 return 1;
1913 gcc_unreachable ();
1916 /* Load the reduction result that was stored in LD_ST_DATA.
1917 REDUCTION_LIST describes the list of reductions that the
1918 loads should be generated for. */
1919 static void
1920 create_final_loads_for_reduction (reduction_info_table_type *reduction_list,
1921 struct clsn_data *ld_st_data)
1923 gimple_stmt_iterator gsi;
1924 tree t;
1925 gimple *stmt;
1927 gsi = gsi_after_labels (ld_st_data->load_bb);
1928 t = build_fold_addr_expr (ld_st_data->store);
1929 stmt = gimple_build_assign (ld_st_data->load, t);
1931 gsi_insert_before (&gsi, stmt, GSI_NEW_STMT);
1933 reduction_list
1934 ->traverse <struct clsn_data *, create_loads_for_reductions> (ld_st_data);
1938 /* Callback for htab_traverse. Store the neutral value for the
1939 particular reduction's operation, e.g. 0 for PLUS_EXPR,
1940 1 for MULT_EXPR, etc. into the reduction field.
1941 The reduction is specified in SLOT. The store information is
1942 passed in DATA. */
1945 create_stores_for_reduction (reduction_info **slot, struct clsn_data *clsn_data)
1947 struct reduction_info *const red = *slot;
1948 tree t;
1949 gimple *stmt;
1950 gimple_stmt_iterator gsi;
1951 tree type = TREE_TYPE (reduc_stmt_res (red->reduc_stmt));
1953 gsi = gsi_last_bb (clsn_data->store_bb);
1954 t = build3 (COMPONENT_REF, type, clsn_data->store, red->field, NULL_TREE);
1955 stmt = gimple_build_assign (t, red->initial_value);
1956 gsi_insert_after (&gsi, stmt, GSI_NEW_STMT);
1958 return 1;
1961 /* Callback for htab_traverse. Creates loads to a field of LOAD in LOAD_BB and
1962 store to a field of STORE in STORE_BB for the ssa name and its duplicate
1963 specified in SLOT. */
1966 create_loads_and_stores_for_name (name_to_copy_elt **slot,
1967 struct clsn_data *clsn_data)
1969 struct name_to_copy_elt *const elt = *slot;
1970 tree t;
1971 gimple *stmt;
1972 gimple_stmt_iterator gsi;
1973 tree type = TREE_TYPE (elt->new_name);
1974 tree load_struct;
1976 gsi = gsi_last_bb (clsn_data->store_bb);
1977 t = build3 (COMPONENT_REF, type, clsn_data->store, elt->field, NULL_TREE);
1978 stmt = gimple_build_assign (t, ssa_name (elt->version));
1979 gsi_insert_after (&gsi, stmt, GSI_NEW_STMT);
1981 gsi = gsi_last_bb (clsn_data->load_bb);
1982 load_struct = build_simple_mem_ref (clsn_data->load);
1983 t = build3 (COMPONENT_REF, type, load_struct, elt->field, NULL_TREE);
1984 stmt = gimple_build_assign (elt->new_name, t);
1985 gsi_insert_after (&gsi, stmt, GSI_NEW_STMT);
1987 return 1;
1990 /* Moves all the variables used in LOOP and defined outside of it (including
1991 the initial values of loop phi nodes, and *PER_THREAD if it is a ssa
1992 name) to a structure created for this purpose. The code
1994 while (1)
1996 use (a);
1997 use (b);
2000 is transformed this way:
2002 bb0:
2003 old.a = a;
2004 old.b = b;
2006 bb1:
2007 a' = new->a;
2008 b' = new->b;
2009 while (1)
2011 use (a');
2012 use (b');
2015 `old' is stored to *ARG_STRUCT and `new' is stored to NEW_ARG_STRUCT. The
2016 pointer `new' is intentionally not initialized (the loop will be split to a
2017 separate function later, and `new' will be initialized from its arguments).
2018 LD_ST_DATA holds information about the shared data structure used to pass
2019 information among the threads. It is initialized here, and
2020 gen_parallel_loop will pass it to create_call_for_reduction that
2021 needs this information. REDUCTION_LIST describes the reductions
2022 in LOOP. */
2024 static void
2025 separate_decls_in_region (edge entry, edge exit,
2026 reduction_info_table_type *reduction_list,
2027 tree *arg_struct, tree *new_arg_struct,
2028 struct clsn_data *ld_st_data)
2031 basic_block bb1 = split_edge (entry);
2032 basic_block bb0 = single_pred (bb1);
2033 name_to_copy_table_type name_copies (10);
2034 int_tree_htab_type decl_copies (10);
2035 unsigned i;
2036 tree type, type_name, nvar;
2037 gimple_stmt_iterator gsi;
2038 struct clsn_data clsn_data;
2039 auto_vec<basic_block, 3> body;
2040 basic_block bb;
2041 basic_block entry_bb = bb1;
2042 basic_block exit_bb = exit->dest;
2043 bool has_debug_stmt = false;
2045 entry = single_succ_edge (entry_bb);
2046 gather_blocks_in_sese_region (entry_bb, exit_bb, &body);
2048 FOR_EACH_VEC_ELT (body, i, bb)
2050 if (bb != entry_bb && bb != exit_bb)
2052 for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
2053 separate_decls_in_region_stmt (entry, exit, gsi_stmt (gsi),
2054 &name_copies, &decl_copies);
2056 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
2058 gimple *stmt = gsi_stmt (gsi);
2060 if (is_gimple_debug (stmt))
2061 has_debug_stmt = true;
2062 else
2063 separate_decls_in_region_stmt (entry, exit, stmt,
2064 &name_copies, &decl_copies);
2069 /* Now process debug bind stmts. We must not create decls while
2070 processing debug stmts, so we defer their processing so as to
2071 make sure we will have debug info for as many variables as
2072 possible (all of those that were dealt with in the loop above),
2073 and discard those for which we know there's nothing we can
2074 do. */
2075 if (has_debug_stmt)
2076 FOR_EACH_VEC_ELT (body, i, bb)
2077 if (bb != entry_bb && bb != exit_bb)
2079 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi);)
2081 gimple *stmt = gsi_stmt (gsi);
2083 if (is_gimple_debug (stmt))
2085 if (separate_decls_in_region_debug (stmt, &name_copies,
2086 &decl_copies))
2088 gsi_remove (&gsi, true);
2089 continue;
2093 gsi_next (&gsi);
2097 if (name_copies.is_empty () && reduction_list->is_empty ())
2099 /* It may happen that there is nothing to copy (if there are only
2100 loop carried and external variables in the loop). */
2101 *arg_struct = NULL;
2102 *new_arg_struct = NULL;
2104 else
2106 /* Create the type for the structure to store the ssa names to. */
2107 type = lang_hooks.types.make_type (RECORD_TYPE);
2108 type_name = build_decl (UNKNOWN_LOCATION,
2109 TYPE_DECL, create_tmp_var_name (".paral_data"),
2110 type);
2111 TYPE_NAME (type) = type_name;
2113 name_copies.traverse <tree, add_field_for_name> (type);
2114 if (reduction_list && !reduction_list->is_empty ())
2116 /* Create the fields for reductions. */
2117 reduction_list->traverse <tree, add_field_for_reduction> (type);
2119 layout_type (type);
2121 /* Create the loads and stores. */
2122 *arg_struct = create_tmp_var (type, ".paral_data_store");
2123 nvar = create_tmp_var (build_pointer_type (type), ".paral_data_load");
2124 *new_arg_struct = make_ssa_name (nvar);
2126 ld_st_data->store = *arg_struct;
2127 ld_st_data->load = *new_arg_struct;
2128 ld_st_data->store_bb = bb0;
2129 ld_st_data->load_bb = bb1;
2131 name_copies
2132 .traverse <struct clsn_data *, create_loads_and_stores_for_name>
2133 (ld_st_data);
2135 /* Load the calculation from memory (after the join of the threads). */
2137 if (reduction_list && !reduction_list->is_empty ())
2139 reduction_list
2140 ->traverse <struct clsn_data *, create_stores_for_reduction>
2141 (ld_st_data);
2142 clsn_data.load = make_ssa_name (nvar);
2143 clsn_data.load_bb = exit->dest;
2144 clsn_data.store = ld_st_data->store;
2145 create_final_loads_for_reduction (reduction_list, &clsn_data);
2150 /* Returns true if FN was created to run in parallel. */
2152 bool
2153 parallelized_function_p (tree fndecl)
2155 cgraph_node *node = cgraph_node::get (fndecl);
2156 gcc_assert (node != NULL);
2157 return node->parallelized_function;
2160 /* Creates and returns an empty function that will receive the body of
2161 a parallelized loop. */
2163 static tree
2164 create_loop_fn (location_t loc)
2166 char buf[100];
2167 char *tname;
2168 tree decl, type, name, t;
2169 struct function *act_cfun = cfun;
2170 static unsigned loopfn_num;
2172 loc = LOCATION_LOCUS (loc);
2173 snprintf (buf, 100, "%s.$loopfn", current_function_name ());
2174 ASM_FORMAT_PRIVATE_NAME (tname, buf, loopfn_num++);
2175 clean_symbol_name (tname);
2176 name = get_identifier (tname);
2177 type = build_function_type_list (void_type_node, ptr_type_node, NULL_TREE);
2179 decl = build_decl (loc, FUNCTION_DECL, name, type);
2180 TREE_STATIC (decl) = 1;
2181 TREE_USED (decl) = 1;
2182 DECL_ARTIFICIAL (decl) = 1;
2183 DECL_IGNORED_P (decl) = 0;
2184 TREE_PUBLIC (decl) = 0;
2185 DECL_UNINLINABLE (decl) = 1;
2186 DECL_EXTERNAL (decl) = 0;
2187 DECL_CONTEXT (decl) = NULL_TREE;
2188 DECL_INITIAL (decl) = make_node (BLOCK);
2189 BLOCK_SUPERCONTEXT (DECL_INITIAL (decl)) = decl;
2191 t = build_decl (loc, RESULT_DECL, NULL_TREE, void_type_node);
2192 DECL_ARTIFICIAL (t) = 1;
2193 DECL_IGNORED_P (t) = 1;
2194 DECL_RESULT (decl) = t;
2196 t = build_decl (loc, PARM_DECL, get_identifier (".paral_data_param"),
2197 ptr_type_node);
2198 DECL_ARTIFICIAL (t) = 1;
2199 DECL_ARG_TYPE (t) = ptr_type_node;
2200 DECL_CONTEXT (t) = decl;
2201 TREE_USED (t) = 1;
2202 DECL_ARGUMENTS (decl) = t;
2204 allocate_struct_function (decl, false);
2206 /* The call to allocate_struct_function clobbers CFUN, so we need to restore
2207 it. */
2208 set_cfun (act_cfun);
2210 return decl;
2213 /* Replace uses of NAME by VAL in block BB. */
2215 static void
2216 replace_uses_in_bb_by (tree name, tree val, basic_block bb)
2218 gimple *use_stmt;
2219 imm_use_iterator imm_iter;
2221 FOR_EACH_IMM_USE_STMT (use_stmt, imm_iter, name)
2223 if (gimple_bb (use_stmt) != bb)
2224 continue;
2226 use_operand_p use_p;
2227 FOR_EACH_IMM_USE_ON_STMT (use_p, imm_iter)
2228 SET_USE (use_p, val);
2232 /* Do transformation from:
2234 <bb preheader>:
2236 goto <bb header>
2238 <bb header>:
2239 ivtmp_a = PHI <ivtmp_init (preheader), ivtmp_b (latch)>
2240 sum_a = PHI <sum_init (preheader), sum_b (latch)>
2242 use (ivtmp_a)
2244 sum_b = sum_a + sum_update
2246 if (ivtmp_a < n)
2247 goto <bb latch>;
2248 else
2249 goto <bb exit>;
2251 <bb latch>:
2252 ivtmp_b = ivtmp_a + 1;
2253 goto <bb header>
2255 <bb exit>:
2256 sum_z = PHI <sum_b (cond[1]), ...>
2258 [1] Where <bb cond> is single_pred (bb latch); In the simplest case,
2259 that's <bb header>.
2263 <bb preheader>:
2265 goto <bb newheader>
2267 <bb header>:
2268 ivtmp_a = PHI <ivtmp_c (latch)>
2269 sum_a = PHI <sum_c (latch)>
2271 use (ivtmp_a)
2273 sum_b = sum_a + sum_update
2275 goto <bb latch>;
2277 <bb newheader>:
2278 ivtmp_c = PHI <ivtmp_init (preheader), ivtmp_b (latch)>
2279 sum_c = PHI <sum_init (preheader), sum_b (latch)>
2280 if (ivtmp_c < n + 1)
2281 goto <bb header>;
2282 else
2283 goto <bb newexit>;
2285 <bb latch>:
2286 ivtmp_b = ivtmp_a + 1;
2287 goto <bb newheader>
2289 <bb newexit>:
2290 sum_y = PHI <sum_c (newheader)>
2292 <bb exit>:
2293 sum_z = PHI <sum_y (newexit), ...>
2296 In unified diff format:
2298 <bb preheader>:
2300 - goto <bb header>
2301 + goto <bb newheader>
2303 <bb header>:
2304 - ivtmp_a = PHI <ivtmp_init (preheader), ivtmp_b (latch)>
2305 - sum_a = PHI <sum_init (preheader), sum_b (latch)>
2306 + ivtmp_a = PHI <ivtmp_c (latch)>
2307 + sum_a = PHI <sum_c (latch)>
2309 use (ivtmp_a)
2311 sum_b = sum_a + sum_update
2313 - if (ivtmp_a < n)
2314 - goto <bb latch>;
2315 + goto <bb latch>;
2317 + <bb newheader>:
2318 + ivtmp_c = PHI <ivtmp_init (preheader), ivtmp_b (latch)>
2319 + sum_c = PHI <sum_init (preheader), sum_b (latch)>
2320 + if (ivtmp_c < n + 1)
2321 + goto <bb header>;
2322 else
2323 goto <bb exit>;
2325 <bb latch>:
2326 ivtmp_b = ivtmp_a + 1;
2327 - goto <bb header>
2328 + goto <bb newheader>
2330 + <bb newexit>:
2331 + sum_y = PHI <sum_c (newheader)>
2333 <bb exit>:
2334 - sum_z = PHI <sum_b (cond[1]), ...>
2335 + sum_z = PHI <sum_y (newexit), ...>
2337 Note: the example does not show any virtual phis, but these are handled more
2338 or less as reductions.
2341 Moves the exit condition of LOOP to the beginning of its header.
2342 REDUCTION_LIST describes the reductions in LOOP. BOUND is the new loop
2343 bound. */
2345 static void
2346 transform_to_exit_first_loop_alt (class loop *loop,
2347 reduction_info_table_type *reduction_list,
2348 tree bound)
2350 basic_block header = loop->header;
2351 basic_block latch = loop->latch;
2352 edge exit = single_dom_exit (loop);
2353 basic_block exit_block = exit->dest;
2354 gcond *cond_stmt = as_a <gcond *> (last_stmt (exit->src));
2355 tree control = gimple_cond_lhs (cond_stmt);
2356 edge e;
2358 /* Rewriting virtuals into loop-closed ssa normal form makes this
2359 transformation simpler. It also ensures that the virtuals are in
2360 loop-closed ssa normal from after the transformation, which is required by
2361 create_parallel_loop. */
2362 rewrite_virtuals_into_loop_closed_ssa (loop);
2364 /* Create the new_header block. */
2365 basic_block new_header = split_block_before_cond_jump (exit->src);
2366 edge edge_at_split = single_pred_edge (new_header);
2368 /* Redirect entry edge to new_header. */
2369 edge entry = loop_preheader_edge (loop);
2370 e = redirect_edge_and_branch (entry, new_header);
2371 gcc_assert (e == entry);
2373 /* Redirect post_inc_edge to new_header. */
2374 edge post_inc_edge = single_succ_edge (latch);
2375 e = redirect_edge_and_branch (post_inc_edge, new_header);
2376 gcc_assert (e == post_inc_edge);
2378 /* Redirect post_cond_edge to header. */
2379 edge post_cond_edge = single_pred_edge (latch);
2380 e = redirect_edge_and_branch (post_cond_edge, header);
2381 gcc_assert (e == post_cond_edge);
2383 /* Redirect edge_at_split to latch. */
2384 e = redirect_edge_and_branch (edge_at_split, latch);
2385 gcc_assert (e == edge_at_split);
2387 /* Set the new loop bound. */
2388 gimple_cond_set_rhs (cond_stmt, bound);
2389 update_stmt (cond_stmt);
2391 /* Repair the ssa. */
2392 vec<edge_var_map> *v = redirect_edge_var_map_vector (post_inc_edge);
2393 edge_var_map *vm;
2394 gphi_iterator gsi;
2395 int i;
2396 for (gsi = gsi_start_phis (header), i = 0;
2397 !gsi_end_p (gsi) && v->iterate (i, &vm);
2398 gsi_next (&gsi), i++)
2400 gphi *phi = gsi.phi ();
2401 tree res_a = PHI_RESULT (phi);
2403 /* Create new phi. */
2404 tree res_c = copy_ssa_name (res_a, phi);
2405 gphi *nphi = create_phi_node (res_c, new_header);
2407 /* Replace ivtmp_a with ivtmp_c in condition 'if (ivtmp_a < n)'. */
2408 replace_uses_in_bb_by (res_a, res_c, new_header);
2410 /* Replace ivtmp/sum_b with ivtmp/sum_c in header phi. */
2411 add_phi_arg (phi, res_c, post_cond_edge, UNKNOWN_LOCATION);
2413 /* Replace sum_b with sum_c in exit phi. */
2414 tree res_b = redirect_edge_var_map_def (vm);
2415 replace_uses_in_bb_by (res_b, res_c, exit_block);
2417 struct reduction_info *red = reduction_phi (reduction_list, phi);
2418 gcc_assert (virtual_operand_p (res_a)
2419 || res_a == control
2420 || red != NULL);
2422 if (red)
2424 /* Register the new reduction phi. */
2425 red->reduc_phi = nphi;
2426 gimple_set_uid (red->reduc_phi, red->reduc_version);
2429 gcc_assert (gsi_end_p (gsi) && !v->iterate (i, &vm));
2431 /* Set the preheader argument of the new phis to ivtmp/sum_init. */
2432 flush_pending_stmts (entry);
2434 /* Set the latch arguments of the new phis to ivtmp/sum_b. */
2435 flush_pending_stmts (post_inc_edge);
2438 basic_block new_exit_block = NULL;
2439 if (!single_pred_p (exit->dest))
2441 /* Create a new empty exit block, inbetween the new loop header and the
2442 old exit block. The function separate_decls_in_region needs this block
2443 to insert code that is active on loop exit, but not any other path. */
2444 new_exit_block = split_edge (exit);
2447 /* Insert and register the reduction exit phis. */
2448 for (gphi_iterator gsi = gsi_start_phis (exit_block);
2449 !gsi_end_p (gsi);
2450 gsi_next (&gsi))
2452 gphi *phi = gsi.phi ();
2453 gphi *nphi = NULL;
2454 tree res_z = PHI_RESULT (phi);
2455 tree res_c;
2457 if (new_exit_block != NULL)
2459 /* Now that we have a new exit block, duplicate the phi of the old
2460 exit block in the new exit block to preserve loop-closed ssa. */
2461 edge succ_new_exit_block = single_succ_edge (new_exit_block);
2462 edge pred_new_exit_block = single_pred_edge (new_exit_block);
2463 tree res_y = copy_ssa_name (res_z, phi);
2464 nphi = create_phi_node (res_y, new_exit_block);
2465 res_c = PHI_ARG_DEF_FROM_EDGE (phi, succ_new_exit_block);
2466 add_phi_arg (nphi, res_c, pred_new_exit_block, UNKNOWN_LOCATION);
2467 add_phi_arg (phi, res_y, succ_new_exit_block, UNKNOWN_LOCATION);
2469 else
2470 res_c = PHI_ARG_DEF_FROM_EDGE (phi, exit);
2472 if (virtual_operand_p (res_z))
2473 continue;
2475 gimple *reduc_phi = SSA_NAME_DEF_STMT (res_c);
2476 struct reduction_info *red = reduction_phi (reduction_list, reduc_phi);
2477 if (red != NULL)
2478 red->keep_res = (nphi != NULL
2479 ? nphi
2480 : phi);
2483 /* We're going to cancel the loop at the end of gen_parallel_loop, but until
2484 then we're still using some fields, so only bother about fields that are
2485 still used: header and latch.
2486 The loop has a new header bb, so we update it. The latch bb stays the
2487 same. */
2488 loop->header = new_header;
2490 /* Recalculate dominance info. */
2491 free_dominance_info (CDI_DOMINATORS);
2492 calculate_dominance_info (CDI_DOMINATORS);
2494 checking_verify_ssa (true, true);
2497 /* Tries to moves the exit condition of LOOP to the beginning of its header
2498 without duplication of the loop body. NIT is the number of iterations of the
2499 loop. REDUCTION_LIST describes the reductions in LOOP. Return true if
2500 transformation is successful. */
2502 static bool
2503 try_transform_to_exit_first_loop_alt (class loop *loop,
2504 reduction_info_table_type *reduction_list,
2505 tree nit)
2507 /* Check whether the latch contains a single statement. */
2508 if (!gimple_seq_nondebug_singleton_p (bb_seq (loop->latch)))
2509 return false;
2511 /* Check whether the latch contains no phis. */
2512 if (phi_nodes (loop->latch) != NULL)
2513 return false;
2515 /* Check whether the latch contains the loop iv increment. */
2516 edge back = single_succ_edge (loop->latch);
2517 edge exit = single_dom_exit (loop);
2518 gcond *cond_stmt = as_a <gcond *> (last_stmt (exit->src));
2519 tree control = gimple_cond_lhs (cond_stmt);
2520 gphi *phi = as_a <gphi *> (SSA_NAME_DEF_STMT (control));
2521 tree inc_res = gimple_phi_arg_def (phi, back->dest_idx);
2522 if (gimple_bb (SSA_NAME_DEF_STMT (inc_res)) != loop->latch)
2523 return false;
2525 /* Check whether there's no code between the loop condition and the latch. */
2526 if (!single_pred_p (loop->latch)
2527 || single_pred (loop->latch) != exit->src)
2528 return false;
2530 tree alt_bound = NULL_TREE;
2531 tree nit_type = TREE_TYPE (nit);
2533 /* Figure out whether nit + 1 overflows. */
2534 if (TREE_CODE (nit) == INTEGER_CST)
2536 if (!tree_int_cst_equal (nit, TYPE_MAX_VALUE (nit_type)))
2538 alt_bound = fold_build2_loc (UNKNOWN_LOCATION, PLUS_EXPR, nit_type,
2539 nit, build_one_cst (nit_type));
2541 gcc_assert (TREE_CODE (alt_bound) == INTEGER_CST);
2542 transform_to_exit_first_loop_alt (loop, reduction_list, alt_bound);
2543 return true;
2545 else
2547 /* Todo: Figure out if we can trigger this, if it's worth to handle
2548 optimally, and if we can handle it optimally. */
2549 return false;
2553 gcc_assert (TREE_CODE (nit) == SSA_NAME);
2555 /* Variable nit is the loop bound as returned by canonicalize_loop_ivs, for an
2556 iv with base 0 and step 1 that is incremented in the latch, like this:
2558 <bb header>:
2559 # iv_1 = PHI <0 (preheader), iv_2 (latch)>
2561 if (iv_1 < nit)
2562 goto <bb latch>;
2563 else
2564 goto <bb exit>;
2566 <bb latch>:
2567 iv_2 = iv_1 + 1;
2568 goto <bb header>;
2570 The range of iv_1 is [0, nit]. The latch edge is taken for
2571 iv_1 == [0, nit - 1] and the exit edge is taken for iv_1 == nit. So the
2572 number of latch executions is equal to nit.
2574 The function max_loop_iterations gives us the maximum number of latch
2575 executions, so it gives us the maximum value of nit. */
2576 widest_int nit_max;
2577 if (!max_loop_iterations (loop, &nit_max))
2578 return false;
2580 /* Check if nit + 1 overflows. */
2581 widest_int type_max = wi::to_widest (TYPE_MAX_VALUE (nit_type));
2582 if (nit_max >= type_max)
2583 return false;
2585 gimple *def = SSA_NAME_DEF_STMT (nit);
2587 /* Try to find nit + 1, in the form of n in an assignment nit = n - 1. */
2588 if (def
2589 && is_gimple_assign (def)
2590 && gimple_assign_rhs_code (def) == PLUS_EXPR)
2592 tree op1 = gimple_assign_rhs1 (def);
2593 tree op2 = gimple_assign_rhs2 (def);
2594 if (integer_minus_onep (op1))
2595 alt_bound = op2;
2596 else if (integer_minus_onep (op2))
2597 alt_bound = op1;
2600 /* If not found, insert nit + 1. */
2601 if (alt_bound == NULL_TREE)
2603 alt_bound = fold_build2 (PLUS_EXPR, nit_type, nit,
2604 build_int_cst_type (nit_type, 1));
2606 gimple_stmt_iterator gsi = gsi_last_bb (loop_preheader_edge (loop)->src);
2608 alt_bound
2609 = force_gimple_operand_gsi (&gsi, alt_bound, true, NULL_TREE, false,
2610 GSI_CONTINUE_LINKING);
2613 transform_to_exit_first_loop_alt (loop, reduction_list, alt_bound);
2614 return true;
2617 /* Moves the exit condition of LOOP to the beginning of its header. NIT is the
2618 number of iterations of the loop. REDUCTION_LIST describes the reductions in
2619 LOOP. */
2621 static void
2622 transform_to_exit_first_loop (class loop *loop,
2623 reduction_info_table_type *reduction_list,
2624 tree nit)
2626 basic_block *bbs, *nbbs, ex_bb, orig_header;
2627 unsigned n;
2628 bool ok;
2629 edge exit = single_dom_exit (loop), hpred;
2630 tree control, control_name, res, t;
2631 gphi *phi, *nphi;
2632 gassign *stmt;
2633 gcond *cond_stmt, *cond_nit;
2634 tree nit_1;
2636 split_block_after_labels (loop->header);
2637 orig_header = single_succ (loop->header);
2638 hpred = single_succ_edge (loop->header);
2640 cond_stmt = as_a <gcond *> (last_stmt (exit->src));
2641 control = gimple_cond_lhs (cond_stmt);
2642 gcc_assert (gimple_cond_rhs (cond_stmt) == nit);
2644 /* Make sure that we have phi nodes on exit for all loop header phis
2645 (create_parallel_loop requires that). */
2646 for (gphi_iterator gsi = gsi_start_phis (loop->header);
2647 !gsi_end_p (gsi);
2648 gsi_next (&gsi))
2650 phi = gsi.phi ();
2651 res = PHI_RESULT (phi);
2652 t = copy_ssa_name (res, phi);
2653 SET_PHI_RESULT (phi, t);
2654 nphi = create_phi_node (res, orig_header);
2655 add_phi_arg (nphi, t, hpred, UNKNOWN_LOCATION);
2657 if (res == control)
2659 gimple_cond_set_lhs (cond_stmt, t);
2660 update_stmt (cond_stmt);
2661 control = t;
2665 bbs = get_loop_body_in_dom_order (loop);
2667 for (n = 0; bbs[n] != exit->src; n++)
2668 continue;
2669 nbbs = XNEWVEC (basic_block, n);
2670 ok = gimple_duplicate_sese_tail (single_succ_edge (loop->header), exit,
2671 bbs + 1, n, nbbs);
2672 gcc_assert (ok);
2673 free (bbs);
2674 ex_bb = nbbs[0];
2675 free (nbbs);
2677 /* Other than reductions, the only gimple reg that should be copied
2678 out of the loop is the control variable. */
2679 exit = single_dom_exit (loop);
2680 control_name = NULL_TREE;
2681 for (gphi_iterator gsi = gsi_start_phis (ex_bb);
2682 !gsi_end_p (gsi); )
2684 phi = gsi.phi ();
2685 res = PHI_RESULT (phi);
2686 if (virtual_operand_p (res))
2688 gsi_next (&gsi);
2689 continue;
2692 /* Check if it is a part of reduction. If it is,
2693 keep the phi at the reduction's keep_res field. The
2694 PHI_RESULT of this phi is the resulting value of the reduction
2695 variable when exiting the loop. */
2697 if (!reduction_list->is_empty ())
2699 struct reduction_info *red;
2701 tree val = PHI_ARG_DEF_FROM_EDGE (phi, exit);
2702 red = reduction_phi (reduction_list, SSA_NAME_DEF_STMT (val));
2703 if (red)
2705 red->keep_res = phi;
2706 gsi_next (&gsi);
2707 continue;
2710 gcc_assert (control_name == NULL_TREE
2711 && SSA_NAME_VAR (res) == SSA_NAME_VAR (control));
2712 control_name = res;
2713 remove_phi_node (&gsi, false);
2715 gcc_assert (control_name != NULL_TREE);
2717 /* Initialize the control variable to number of iterations
2718 according to the rhs of the exit condition. */
2719 gimple_stmt_iterator gsi = gsi_after_labels (ex_bb);
2720 cond_nit = as_a <gcond *> (last_stmt (exit->src));
2721 nit_1 = gimple_cond_rhs (cond_nit);
2722 nit_1 = force_gimple_operand_gsi (&gsi,
2723 fold_convert (TREE_TYPE (control_name), nit_1),
2724 false, NULL_TREE, false, GSI_SAME_STMT);
2725 stmt = gimple_build_assign (control_name, nit_1);
2726 gsi_insert_before (&gsi, stmt, GSI_NEW_STMT);
2729 /* Create the parallel constructs for LOOP as described in gen_parallel_loop.
2730 LOOP_FN and DATA are the arguments of GIMPLE_OMP_PARALLEL.
2731 NEW_DATA is the variable that should be initialized from the argument
2732 of LOOP_FN. N_THREADS is the requested number of threads, which can be 0 if
2733 that number is to be determined later. */
2735 static void
2736 create_parallel_loop (class loop *loop, tree loop_fn, tree data,
2737 tree new_data, unsigned n_threads, location_t loc,
2738 bool oacc_kernels_p)
2740 gimple_stmt_iterator gsi;
2741 basic_block for_bb, ex_bb, continue_bb;
2742 tree t, param;
2743 gomp_parallel *omp_par_stmt;
2744 gimple *omp_return_stmt1, *omp_return_stmt2;
2745 gimple *phi;
2746 gcond *cond_stmt;
2747 gomp_for *for_stmt;
2748 gomp_continue *omp_cont_stmt;
2749 tree cvar, cvar_init, initvar, cvar_next, cvar_base, type;
2750 edge exit, nexit, guard, end, e;
2752 if (oacc_kernels_p)
2754 gcc_checking_assert (lookup_attribute ("oacc kernels",
2755 DECL_ATTRIBUTES (cfun->decl)));
2756 /* Indicate to later processing that this is a parallelized OpenACC
2757 kernels construct. */
2758 DECL_ATTRIBUTES (cfun->decl)
2759 = tree_cons (get_identifier ("oacc kernels parallelized"),
2760 NULL_TREE, DECL_ATTRIBUTES (cfun->decl));
2762 else
2764 /* Prepare the GIMPLE_OMP_PARALLEL statement. */
2766 basic_block bb = loop_preheader_edge (loop)->src;
2767 basic_block paral_bb = single_pred (bb);
2768 gsi = gsi_last_bb (paral_bb);
2770 gcc_checking_assert (n_threads != 0);
2771 t = build_omp_clause (loc, OMP_CLAUSE_NUM_THREADS);
2772 OMP_CLAUSE_NUM_THREADS_EXPR (t)
2773 = build_int_cst (integer_type_node, n_threads);
2774 omp_par_stmt = gimple_build_omp_parallel (NULL, t, loop_fn, data);
2775 gimple_set_location (omp_par_stmt, loc);
2777 gsi_insert_after (&gsi, omp_par_stmt, GSI_NEW_STMT);
2779 /* Initialize NEW_DATA. */
2780 if (data)
2782 gassign *assign_stmt;
2784 gsi = gsi_after_labels (bb);
2786 param = make_ssa_name (DECL_ARGUMENTS (loop_fn));
2787 assign_stmt = gimple_build_assign (param, build_fold_addr_expr (data));
2788 gsi_insert_before (&gsi, assign_stmt, GSI_SAME_STMT);
2790 assign_stmt = gimple_build_assign (new_data,
2791 fold_convert (TREE_TYPE (new_data), param));
2792 gsi_insert_before (&gsi, assign_stmt, GSI_SAME_STMT);
2795 /* Emit GIMPLE_OMP_RETURN for GIMPLE_OMP_PARALLEL. */
2796 bb = split_loop_exit_edge (single_dom_exit (loop));
2797 gsi = gsi_last_bb (bb);
2798 omp_return_stmt1 = gimple_build_omp_return (false);
2799 gimple_set_location (omp_return_stmt1, loc);
2800 gsi_insert_after (&gsi, omp_return_stmt1, GSI_NEW_STMT);
2803 /* Extract data for GIMPLE_OMP_FOR. */
2804 gcc_assert (loop->header == single_dom_exit (loop)->src);
2805 cond_stmt = as_a <gcond *> (last_stmt (loop->header));
2807 cvar = gimple_cond_lhs (cond_stmt);
2808 cvar_base = SSA_NAME_VAR (cvar);
2809 phi = SSA_NAME_DEF_STMT (cvar);
2810 cvar_init = PHI_ARG_DEF_FROM_EDGE (phi, loop_preheader_edge (loop));
2811 initvar = copy_ssa_name (cvar);
2812 SET_USE (PHI_ARG_DEF_PTR_FROM_EDGE (phi, loop_preheader_edge (loop)),
2813 initvar);
2814 cvar_next = PHI_ARG_DEF_FROM_EDGE (phi, loop_latch_edge (loop));
2816 gsi = gsi_last_nondebug_bb (loop->latch);
2817 gcc_assert (gsi_stmt (gsi) == SSA_NAME_DEF_STMT (cvar_next));
2818 gsi_remove (&gsi, true);
2820 /* Prepare cfg. */
2821 for_bb = split_edge (loop_preheader_edge (loop));
2822 ex_bb = split_loop_exit_edge (single_dom_exit (loop));
2823 extract_true_false_edges_from_block (loop->header, &nexit, &exit);
2824 gcc_assert (exit == single_dom_exit (loop));
2826 guard = make_edge (for_bb, ex_bb, 0);
2827 /* FIXME: What is the probability? */
2828 guard->probability = profile_probability::guessed_never ();
2829 /* Split the latch edge, so LOOPS_HAVE_SIMPLE_LATCHES is still valid. */
2830 loop->latch = split_edge (single_succ_edge (loop->latch));
2831 single_pred_edge (loop->latch)->flags = 0;
2832 end = make_single_succ_edge (single_pred (loop->latch), ex_bb, EDGE_FALLTHRU);
2833 rescan_loop_exit (end, true, false);
2835 for (gphi_iterator gpi = gsi_start_phis (ex_bb);
2836 !gsi_end_p (gpi); gsi_next (&gpi))
2838 location_t locus;
2839 gphi *phi = gpi.phi ();
2840 tree def = PHI_ARG_DEF_FROM_EDGE (phi, exit);
2841 gimple *def_stmt = SSA_NAME_DEF_STMT (def);
2843 /* If the exit phi is not connected to a header phi in the same loop, this
2844 value is not modified in the loop, and we're done with this phi. */
2845 if (!(gimple_code (def_stmt) == GIMPLE_PHI
2846 && gimple_bb (def_stmt) == loop->header))
2848 locus = gimple_phi_arg_location_from_edge (phi, exit);
2849 add_phi_arg (phi, def, guard, locus);
2850 add_phi_arg (phi, def, end, locus);
2851 continue;
2854 gphi *stmt = as_a <gphi *> (def_stmt);
2855 def = PHI_ARG_DEF_FROM_EDGE (stmt, loop_preheader_edge (loop));
2856 locus = gimple_phi_arg_location_from_edge (stmt,
2857 loop_preheader_edge (loop));
2858 add_phi_arg (phi, def, guard, locus);
2860 def = PHI_ARG_DEF_FROM_EDGE (stmt, loop_latch_edge (loop));
2861 locus = gimple_phi_arg_location_from_edge (stmt, loop_latch_edge (loop));
2862 add_phi_arg (phi, def, end, locus);
2864 e = redirect_edge_and_branch (exit, nexit->dest);
2865 PENDING_STMT (e) = NULL;
2867 /* Emit GIMPLE_OMP_FOR. */
2868 if (oacc_kernels_p)
2869 /* Parallelized OpenACC kernels constructs use gang parallelism. See also
2870 omp-offload.c:execute_oacc_loop_designation. */
2871 t = build_omp_clause (loc, OMP_CLAUSE_GANG);
2872 else
2874 t = build_omp_clause (loc, OMP_CLAUSE_SCHEDULE);
2875 int chunk_size = param_parloops_chunk_size;
2876 switch (param_parloops_schedule)
2878 case PARLOOPS_SCHEDULE_STATIC:
2879 OMP_CLAUSE_SCHEDULE_KIND (t) = OMP_CLAUSE_SCHEDULE_STATIC;
2880 break;
2881 case PARLOOPS_SCHEDULE_DYNAMIC:
2882 OMP_CLAUSE_SCHEDULE_KIND (t) = OMP_CLAUSE_SCHEDULE_DYNAMIC;
2883 break;
2884 case PARLOOPS_SCHEDULE_GUIDED:
2885 OMP_CLAUSE_SCHEDULE_KIND (t) = OMP_CLAUSE_SCHEDULE_GUIDED;
2886 break;
2887 case PARLOOPS_SCHEDULE_AUTO:
2888 OMP_CLAUSE_SCHEDULE_KIND (t) = OMP_CLAUSE_SCHEDULE_AUTO;
2889 chunk_size = 0;
2890 break;
2891 case PARLOOPS_SCHEDULE_RUNTIME:
2892 OMP_CLAUSE_SCHEDULE_KIND (t) = OMP_CLAUSE_SCHEDULE_RUNTIME;
2893 chunk_size = 0;
2894 break;
2895 default:
2896 gcc_unreachable ();
2898 if (chunk_size != 0)
2899 OMP_CLAUSE_SCHEDULE_CHUNK_EXPR (t)
2900 = build_int_cst (integer_type_node, chunk_size);
2903 for_stmt = gimple_build_omp_for (NULL,
2904 (oacc_kernels_p
2905 ? GF_OMP_FOR_KIND_OACC_LOOP
2906 : GF_OMP_FOR_KIND_FOR),
2907 t, 1, NULL);
2909 gimple_cond_set_lhs (cond_stmt, cvar_base);
2910 type = TREE_TYPE (cvar);
2911 gimple_set_location (for_stmt, loc);
2912 gimple_omp_for_set_index (for_stmt, 0, initvar);
2913 gimple_omp_for_set_initial (for_stmt, 0, cvar_init);
2914 gimple_omp_for_set_final (for_stmt, 0, gimple_cond_rhs (cond_stmt));
2915 gimple_omp_for_set_cond (for_stmt, 0, gimple_cond_code (cond_stmt));
2916 gimple_omp_for_set_incr (for_stmt, 0, build2 (PLUS_EXPR, type,
2917 cvar_base,
2918 build_int_cst (type, 1)));
2920 gsi = gsi_last_bb (for_bb);
2921 gsi_insert_after (&gsi, for_stmt, GSI_NEW_STMT);
2922 SSA_NAME_DEF_STMT (initvar) = for_stmt;
2924 /* Emit GIMPLE_OMP_CONTINUE. */
2925 continue_bb = single_pred (loop->latch);
2926 gsi = gsi_last_bb (continue_bb);
2927 omp_cont_stmt = gimple_build_omp_continue (cvar_next, cvar);
2928 gimple_set_location (omp_cont_stmt, loc);
2929 gsi_insert_after (&gsi, omp_cont_stmt, GSI_NEW_STMT);
2930 SSA_NAME_DEF_STMT (cvar_next) = omp_cont_stmt;
2932 /* Emit GIMPLE_OMP_RETURN for GIMPLE_OMP_FOR. */
2933 gsi = gsi_last_bb (ex_bb);
2934 omp_return_stmt2 = gimple_build_omp_return (true);
2935 gimple_set_location (omp_return_stmt2, loc);
2936 gsi_insert_after (&gsi, omp_return_stmt2, GSI_NEW_STMT);
2938 /* After the above dom info is hosed. Re-compute it. */
2939 free_dominance_info (CDI_DOMINATORS);
2940 calculate_dominance_info (CDI_DOMINATORS);
2943 /* Return number of phis in bb. If COUNT_VIRTUAL_P is false, don't count the
2944 virtual phi. */
2946 static unsigned int
2947 num_phis (basic_block bb, bool count_virtual_p)
2949 unsigned int nr_phis = 0;
2950 gphi_iterator gsi;
2951 for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
2953 if (!count_virtual_p && virtual_operand_p (PHI_RESULT (gsi.phi ())))
2954 continue;
2956 nr_phis++;
2959 return nr_phis;
2962 /* Generates code to execute the iterations of LOOP in N_THREADS
2963 threads in parallel, which can be 0 if that number is to be determined
2964 later.
2966 NITER describes number of iterations of LOOP.
2967 REDUCTION_LIST describes the reductions existent in the LOOP. */
2969 static void
2970 gen_parallel_loop (class loop *loop,
2971 reduction_info_table_type *reduction_list,
2972 unsigned n_threads, class tree_niter_desc *niter,
2973 bool oacc_kernels_p)
2975 tree many_iterations_cond, type, nit;
2976 tree arg_struct, new_arg_struct;
2977 gimple_seq stmts;
2978 edge entry, exit;
2979 struct clsn_data clsn_data;
2980 location_t loc;
2981 gimple *cond_stmt;
2982 unsigned int m_p_thread=2;
2984 /* From
2986 ---------------------------------------------------------------------
2987 loop
2989 IV = phi (INIT, IV + STEP)
2990 BODY1;
2991 if (COND)
2992 break;
2993 BODY2;
2995 ---------------------------------------------------------------------
2997 with # of iterations NITER (possibly with MAY_BE_ZERO assumption),
2998 we generate the following code:
3000 ---------------------------------------------------------------------
3002 if (MAY_BE_ZERO
3003 || NITER < MIN_PER_THREAD * N_THREADS)
3004 goto original;
3006 BODY1;
3007 store all local loop-invariant variables used in body of the loop to DATA.
3008 GIMPLE_OMP_PARALLEL (OMP_CLAUSE_NUM_THREADS (N_THREADS), LOOPFN, DATA);
3009 load the variables from DATA.
3010 GIMPLE_OMP_FOR (IV = INIT; COND; IV += STEP) (OMP_CLAUSE_SCHEDULE (static))
3011 BODY2;
3012 BODY1;
3013 GIMPLE_OMP_CONTINUE;
3014 GIMPLE_OMP_RETURN -- GIMPLE_OMP_FOR
3015 GIMPLE_OMP_RETURN -- GIMPLE_OMP_PARALLEL
3016 goto end;
3018 original:
3019 loop
3021 IV = phi (INIT, IV + STEP)
3022 BODY1;
3023 if (COND)
3024 break;
3025 BODY2;
3028 end:
3032 /* Create two versions of the loop -- in the old one, we know that the
3033 number of iterations is large enough, and we will transform it into the
3034 loop that will be split to loop_fn, the new one will be used for the
3035 remaining iterations. */
3037 /* We should compute a better number-of-iterations value for outer loops.
3038 That is, if we have
3040 for (i = 0; i < n; ++i)
3041 for (j = 0; j < m; ++j)
3044 we should compute nit = n * m, not nit = n.
3045 Also may_be_zero handling would need to be adjusted. */
3047 type = TREE_TYPE (niter->niter);
3048 nit = force_gimple_operand (unshare_expr (niter->niter), &stmts, true,
3049 NULL_TREE);
3050 if (stmts)
3051 gsi_insert_seq_on_edge_immediate (loop_preheader_edge (loop), stmts);
3053 if (!oacc_kernels_p)
3055 if (loop->inner)
3056 m_p_thread=2;
3057 else
3058 m_p_thread=MIN_PER_THREAD;
3060 gcc_checking_assert (n_threads != 0);
3061 many_iterations_cond =
3062 fold_build2 (GE_EXPR, boolean_type_node,
3063 nit, build_int_cst (type, m_p_thread * n_threads - 1));
3065 many_iterations_cond
3066 = fold_build2 (TRUTH_AND_EXPR, boolean_type_node,
3067 invert_truthvalue (unshare_expr (niter->may_be_zero)),
3068 many_iterations_cond);
3069 many_iterations_cond
3070 = force_gimple_operand (many_iterations_cond, &stmts, false, NULL_TREE);
3071 if (stmts)
3072 gsi_insert_seq_on_edge_immediate (loop_preheader_edge (loop), stmts);
3073 if (!is_gimple_condexpr (many_iterations_cond))
3075 many_iterations_cond
3076 = force_gimple_operand (many_iterations_cond, &stmts,
3077 true, NULL_TREE);
3078 if (stmts)
3079 gsi_insert_seq_on_edge_immediate (loop_preheader_edge (loop),
3080 stmts);
3083 initialize_original_copy_tables ();
3085 /* We assume that the loop usually iterates a lot. */
3086 loop_version (loop, many_iterations_cond, NULL,
3087 profile_probability::likely (),
3088 profile_probability::unlikely (),
3089 profile_probability::likely (),
3090 profile_probability::unlikely (), true);
3091 update_ssa (TODO_update_ssa);
3092 free_original_copy_tables ();
3095 /* Base all the induction variables in LOOP on a single control one. */
3096 canonicalize_loop_ivs (loop, &nit, true);
3097 if (num_phis (loop->header, false) != reduction_list->elements () + 1)
3099 /* The call to canonicalize_loop_ivs above failed to "base all the
3100 induction variables in LOOP on a single control one". Do damage
3101 control. */
3102 basic_block preheader = loop_preheader_edge (loop)->src;
3103 basic_block cond_bb = single_pred (preheader);
3104 gcond *cond = as_a <gcond *> (gsi_stmt (gsi_last_bb (cond_bb)));
3105 gimple_cond_make_true (cond);
3106 update_stmt (cond);
3107 /* We've gotten rid of the duplicate loop created by loop_version, but
3108 we can't undo whatever canonicalize_loop_ivs has done.
3109 TODO: Fix this properly by ensuring that the call to
3110 canonicalize_loop_ivs succeeds. */
3111 if (dump_file
3112 && (dump_flags & TDF_DETAILS))
3113 fprintf (dump_file, "canonicalize_loop_ivs failed for loop %d,"
3114 " aborting transformation\n", loop->num);
3115 return;
3118 /* Ensure that the exit condition is the first statement in the loop.
3119 The common case is that latch of the loop is empty (apart from the
3120 increment) and immediately follows the loop exit test. Attempt to move the
3121 entry of the loop directly before the exit check and increase the number of
3122 iterations of the loop by one. */
3123 if (try_transform_to_exit_first_loop_alt (loop, reduction_list, nit))
3125 if (dump_file
3126 && (dump_flags & TDF_DETAILS))
3127 fprintf (dump_file,
3128 "alternative exit-first loop transform succeeded"
3129 " for loop %d\n", loop->num);
3131 else
3133 if (oacc_kernels_p)
3134 n_threads = 1;
3136 /* Fall back on the method that handles more cases, but duplicates the
3137 loop body: move the exit condition of LOOP to the beginning of its
3138 header, and duplicate the part of the last iteration that gets disabled
3139 to the exit of the loop. */
3140 transform_to_exit_first_loop (loop, reduction_list, nit);
3143 /* Generate initializations for reductions. */
3144 if (!reduction_list->is_empty ())
3145 reduction_list->traverse <class loop *, initialize_reductions> (loop);
3147 /* Eliminate the references to local variables from the loop. */
3148 gcc_assert (single_exit (loop));
3149 entry = loop_preheader_edge (loop);
3150 exit = single_dom_exit (loop);
3152 /* This rewrites the body in terms of new variables. This has already
3153 been done for oacc_kernels_p in pass_lower_omp/lower_omp (). */
3154 if (!oacc_kernels_p)
3156 eliminate_local_variables (entry, exit);
3157 /* In the old loop, move all variables non-local to the loop to a
3158 structure and back, and create separate decls for the variables used in
3159 loop. */
3160 separate_decls_in_region (entry, exit, reduction_list, &arg_struct,
3161 &new_arg_struct, &clsn_data);
3163 else
3165 arg_struct = NULL_TREE;
3166 new_arg_struct = NULL_TREE;
3167 clsn_data.load = NULL_TREE;
3168 clsn_data.load_bb = exit->dest;
3169 clsn_data.store = NULL_TREE;
3170 clsn_data.store_bb = NULL;
3173 /* Create the parallel constructs. */
3174 loc = UNKNOWN_LOCATION;
3175 cond_stmt = last_stmt (loop->header);
3176 if (cond_stmt)
3177 loc = gimple_location (cond_stmt);
3178 create_parallel_loop (loop, create_loop_fn (loc), arg_struct, new_arg_struct,
3179 n_threads, loc, oacc_kernels_p);
3180 if (!reduction_list->is_empty ())
3181 create_call_for_reduction (loop, reduction_list, &clsn_data);
3183 scev_reset ();
3185 /* Free loop bound estimations that could contain references to
3186 removed statements. */
3187 free_numbers_of_iterations_estimates (cfun);
3190 /* Returns true when LOOP contains vector phi nodes. */
3192 static bool
3193 loop_has_vector_phi_nodes (class loop *loop ATTRIBUTE_UNUSED)
3195 unsigned i;
3196 basic_block *bbs = get_loop_body_in_dom_order (loop);
3197 gphi_iterator gsi;
3198 bool res = true;
3200 for (i = 0; i < loop->num_nodes; i++)
3201 for (gsi = gsi_start_phis (bbs[i]); !gsi_end_p (gsi); gsi_next (&gsi))
3202 if (TREE_CODE (TREE_TYPE (PHI_RESULT (gsi.phi ()))) == VECTOR_TYPE)
3203 goto end;
3205 res = false;
3206 end:
3207 free (bbs);
3208 return res;
3211 /* Create a reduction_info struct, initialize it with REDUC_STMT
3212 and PHI, insert it to the REDUCTION_LIST. */
3214 static void
3215 build_new_reduction (reduction_info_table_type *reduction_list,
3216 gimple *reduc_stmt, gphi *phi)
3218 reduction_info **slot;
3219 struct reduction_info *new_reduction;
3220 enum tree_code reduction_code;
3222 gcc_assert (reduc_stmt);
3224 if (gimple_code (reduc_stmt) == GIMPLE_PHI)
3226 tree op1 = PHI_ARG_DEF (reduc_stmt, 0);
3227 gimple *def1 = SSA_NAME_DEF_STMT (op1);
3228 reduction_code = gimple_assign_rhs_code (def1);
3230 else
3231 reduction_code = gimple_assign_rhs_code (reduc_stmt);
3232 /* Check for OpenMP supported reduction. */
3233 switch (reduction_code)
3235 case PLUS_EXPR:
3236 case MULT_EXPR:
3237 case MAX_EXPR:
3238 case MIN_EXPR:
3239 case BIT_IOR_EXPR:
3240 case BIT_XOR_EXPR:
3241 case BIT_AND_EXPR:
3242 case TRUTH_OR_EXPR:
3243 case TRUTH_XOR_EXPR:
3244 case TRUTH_AND_EXPR:
3245 break;
3246 default:
3247 return;
3250 if (dump_file && (dump_flags & TDF_DETAILS))
3252 fprintf (dump_file,
3253 "Detected reduction. reduction stmt is:\n");
3254 print_gimple_stmt (dump_file, reduc_stmt, 0);
3255 fprintf (dump_file, "\n");
3258 new_reduction = XCNEW (struct reduction_info);
3260 new_reduction->reduc_stmt = reduc_stmt;
3261 new_reduction->reduc_phi = phi;
3262 new_reduction->reduc_version = SSA_NAME_VERSION (gimple_phi_result (phi));
3263 new_reduction->reduction_code = reduction_code;
3264 slot = reduction_list->find_slot (new_reduction, INSERT);
3265 *slot = new_reduction;
3268 /* Callback for htab_traverse. Sets gimple_uid of reduc_phi stmts. */
3271 set_reduc_phi_uids (reduction_info **slot, void *data ATTRIBUTE_UNUSED)
3273 struct reduction_info *const red = *slot;
3274 gimple_set_uid (red->reduc_phi, red->reduc_version);
3275 return 1;
3278 /* Return true if the type of reduction performed by STMT_INFO is suitable
3279 for this pass. */
3281 static bool
3282 valid_reduction_p (stmt_vec_info stmt_info)
3284 /* Parallelization would reassociate the operation, which isn't
3285 allowed for in-order reductions. */
3286 vect_reduction_type reduc_type = STMT_VINFO_REDUC_TYPE (stmt_info);
3287 return reduc_type != FOLD_LEFT_REDUCTION;
3290 /* Detect all reductions in the LOOP, insert them into REDUCTION_LIST. */
3292 static void
3293 gather_scalar_reductions (loop_p loop, reduction_info_table_type *reduction_list)
3295 gphi_iterator gsi;
3296 loop_vec_info simple_loop_info;
3297 auto_vec<gphi *, 4> double_reduc_phis;
3298 auto_vec<gimple *, 4> double_reduc_stmts;
3300 vec_info_shared shared;
3301 simple_loop_info = vect_analyze_loop_form (loop, &shared);
3302 if (simple_loop_info == NULL)
3303 goto gather_done;
3305 for (gsi = gsi_start_phis (loop->header); !gsi_end_p (gsi); gsi_next (&gsi))
3307 gphi *phi = gsi.phi ();
3308 affine_iv iv;
3309 tree res = PHI_RESULT (phi);
3310 bool double_reduc;
3312 if (virtual_operand_p (res))
3313 continue;
3315 if (simple_iv (loop, loop, res, &iv, true))
3316 continue;
3318 stmt_vec_info reduc_stmt_info
3319 = parloops_force_simple_reduction (simple_loop_info,
3320 simple_loop_info->lookup_stmt (phi),
3321 &double_reduc, true);
3322 if (!reduc_stmt_info || !valid_reduction_p (reduc_stmt_info))
3323 continue;
3325 if (double_reduc)
3327 if (loop->inner->inner != NULL)
3328 continue;
3330 double_reduc_phis.safe_push (phi);
3331 double_reduc_stmts.safe_push (reduc_stmt_info->stmt);
3332 continue;
3335 build_new_reduction (reduction_list, reduc_stmt_info->stmt, phi);
3337 delete simple_loop_info;
3339 if (!double_reduc_phis.is_empty ())
3341 vec_info_shared shared;
3342 simple_loop_info = vect_analyze_loop_form (loop->inner, &shared);
3343 if (simple_loop_info)
3345 gphi *phi;
3346 unsigned int i;
3348 FOR_EACH_VEC_ELT (double_reduc_phis, i, phi)
3350 affine_iv iv;
3351 tree res = PHI_RESULT (phi);
3352 bool double_reduc;
3354 use_operand_p use_p;
3355 gimple *inner_stmt;
3356 bool single_use_p = single_imm_use (res, &use_p, &inner_stmt);
3357 gcc_assert (single_use_p);
3358 if (gimple_code (inner_stmt) != GIMPLE_PHI)
3359 continue;
3360 gphi *inner_phi = as_a <gphi *> (inner_stmt);
3361 if (simple_iv (loop->inner, loop->inner, PHI_RESULT (inner_phi),
3362 &iv, true))
3363 continue;
3365 stmt_vec_info inner_phi_info
3366 = simple_loop_info->lookup_stmt (inner_phi);
3367 stmt_vec_info inner_reduc_stmt_info
3368 = parloops_force_simple_reduction (simple_loop_info,
3369 inner_phi_info,
3370 &double_reduc, true);
3371 gcc_assert (!double_reduc);
3372 if (!inner_reduc_stmt_info
3373 || !valid_reduction_p (inner_reduc_stmt_info))
3374 continue;
3376 build_new_reduction (reduction_list, double_reduc_stmts[i], phi);
3378 delete simple_loop_info;
3382 gather_done:
3383 if (reduction_list->is_empty ())
3384 return;
3386 /* As gimple_uid is used by the vectorizer in between vect_analyze_loop_form
3387 and delete simple_loop_info, we can set gimple_uid of reduc_phi stmts only
3388 now. */
3389 basic_block bb;
3390 FOR_EACH_BB_FN (bb, cfun)
3391 for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
3392 gimple_set_uid (gsi_stmt (gsi), (unsigned int)-1);
3393 reduction_list->traverse <void *, set_reduc_phi_uids> (NULL);
3396 /* Try to initialize NITER for code generation part. */
3398 static bool
3399 try_get_loop_niter (loop_p loop, class tree_niter_desc *niter)
3401 edge exit = single_dom_exit (loop);
3403 gcc_assert (exit);
3405 /* We need to know # of iterations, and there should be no uses of values
3406 defined inside loop outside of it, unless the values are invariants of
3407 the loop. */
3408 if (!number_of_iterations_exit (loop, exit, niter, false))
3410 if (dump_file && (dump_flags & TDF_DETAILS))
3411 fprintf (dump_file, " FAILED: number of iterations not known\n");
3412 return false;
3415 return true;
3418 /* Return the default def of the first function argument. */
3420 static tree
3421 get_omp_data_i_param (void)
3423 tree decl = DECL_ARGUMENTS (cfun->decl);
3424 gcc_assert (DECL_CHAIN (decl) == NULL_TREE);
3425 return ssa_default_def (cfun, decl);
3428 /* For PHI in loop header of LOOP, look for pattern:
3430 <bb preheader>
3431 .omp_data_i = &.omp_data_arr;
3432 addr = .omp_data_i->sum;
3433 sum_a = *addr;
3435 <bb header>:
3436 sum_b = PHI <sum_a (preheader), sum_c (latch)>
3438 and return addr. Otherwise, return NULL_TREE. */
3440 static tree
3441 find_reduc_addr (class loop *loop, gphi *phi)
3443 edge e = loop_preheader_edge (loop);
3444 tree arg = PHI_ARG_DEF_FROM_EDGE (phi, e);
3445 gimple *stmt = SSA_NAME_DEF_STMT (arg);
3446 if (!gimple_assign_single_p (stmt))
3447 return NULL_TREE;
3448 tree memref = gimple_assign_rhs1 (stmt);
3449 if (TREE_CODE (memref) != MEM_REF)
3450 return NULL_TREE;
3451 tree addr = TREE_OPERAND (memref, 0);
3453 gimple *stmt2 = SSA_NAME_DEF_STMT (addr);
3454 if (!gimple_assign_single_p (stmt2))
3455 return NULL_TREE;
3456 tree compref = gimple_assign_rhs1 (stmt2);
3457 if (TREE_CODE (compref) != COMPONENT_REF)
3458 return NULL_TREE;
3459 tree addr2 = TREE_OPERAND (compref, 0);
3460 if (TREE_CODE (addr2) != MEM_REF)
3461 return NULL_TREE;
3462 addr2 = TREE_OPERAND (addr2, 0);
3463 if (TREE_CODE (addr2) != SSA_NAME
3464 || addr2 != get_omp_data_i_param ())
3465 return NULL_TREE;
3467 return addr;
3470 /* Try to initialize REDUCTION_LIST for code generation part.
3471 REDUCTION_LIST describes the reductions. */
3473 static bool
3474 try_create_reduction_list (loop_p loop,
3475 reduction_info_table_type *reduction_list,
3476 bool oacc_kernels_p)
3478 edge exit = single_dom_exit (loop);
3479 gphi_iterator gsi;
3481 gcc_assert (exit);
3483 /* Try to get rid of exit phis. */
3484 final_value_replacement_loop (loop);
3486 gather_scalar_reductions (loop, reduction_list);
3489 for (gsi = gsi_start_phis (exit->dest); !gsi_end_p (gsi); gsi_next (&gsi))
3491 gphi *phi = gsi.phi ();
3492 struct reduction_info *red;
3493 imm_use_iterator imm_iter;
3494 use_operand_p use_p;
3495 gimple *reduc_phi;
3496 tree val = PHI_ARG_DEF_FROM_EDGE (phi, exit);
3498 if (!virtual_operand_p (val))
3500 if (TREE_CODE (val) != SSA_NAME)
3502 if (dump_file && (dump_flags & TDF_DETAILS))
3503 fprintf (dump_file,
3504 " FAILED: exit PHI argument invariant.\n");
3505 return false;
3508 if (dump_file && (dump_flags & TDF_DETAILS))
3510 fprintf (dump_file, "phi is ");
3511 print_gimple_stmt (dump_file, phi, 0);
3512 fprintf (dump_file, "arg of phi to exit: value ");
3513 print_generic_expr (dump_file, val);
3514 fprintf (dump_file, " used outside loop\n");
3515 fprintf (dump_file,
3516 " checking if it is part of reduction pattern:\n");
3518 if (reduction_list->is_empty ())
3520 if (dump_file && (dump_flags & TDF_DETAILS))
3521 fprintf (dump_file,
3522 " FAILED: it is not a part of reduction.\n");
3523 return false;
3525 reduc_phi = NULL;
3526 FOR_EACH_IMM_USE_FAST (use_p, imm_iter, val)
3528 if (!gimple_debug_bind_p (USE_STMT (use_p))
3529 && flow_bb_inside_loop_p (loop, gimple_bb (USE_STMT (use_p))))
3531 reduc_phi = USE_STMT (use_p);
3532 break;
3535 red = reduction_phi (reduction_list, reduc_phi);
3536 if (red == NULL)
3538 if (dump_file && (dump_flags & TDF_DETAILS))
3539 fprintf (dump_file,
3540 " FAILED: it is not a part of reduction.\n");
3541 return false;
3543 if (red->keep_res != NULL)
3545 if (dump_file && (dump_flags & TDF_DETAILS))
3546 fprintf (dump_file,
3547 " FAILED: reduction has multiple exit phis.\n");
3548 return false;
3550 red->keep_res = phi;
3551 if (dump_file && (dump_flags & TDF_DETAILS))
3553 fprintf (dump_file, "reduction phi is ");
3554 print_gimple_stmt (dump_file, red->reduc_phi, 0);
3555 fprintf (dump_file, "reduction stmt is ");
3556 print_gimple_stmt (dump_file, red->reduc_stmt, 0);
3561 /* The iterations of the loop may communicate only through bivs whose
3562 iteration space can be distributed efficiently. */
3563 for (gsi = gsi_start_phis (loop->header); !gsi_end_p (gsi); gsi_next (&gsi))
3565 gphi *phi = gsi.phi ();
3566 tree def = PHI_RESULT (phi);
3567 affine_iv iv;
3569 if (!virtual_operand_p (def) && !simple_iv (loop, loop, def, &iv, true))
3571 struct reduction_info *red;
3573 red = reduction_phi (reduction_list, phi);
3574 if (red == NULL)
3576 if (dump_file && (dump_flags & TDF_DETAILS))
3577 fprintf (dump_file,
3578 " FAILED: scalar dependency between iterations\n");
3579 return false;
3584 if (oacc_kernels_p)
3586 for (gsi = gsi_start_phis (loop->header); !gsi_end_p (gsi);
3587 gsi_next (&gsi))
3589 gphi *phi = gsi.phi ();
3590 tree def = PHI_RESULT (phi);
3591 affine_iv iv;
3593 if (!virtual_operand_p (def)
3594 && !simple_iv (loop, loop, def, &iv, true))
3596 tree addr = find_reduc_addr (loop, phi);
3597 if (addr == NULL_TREE)
3598 return false;
3599 struct reduction_info *red = reduction_phi (reduction_list, phi);
3600 red->reduc_addr = addr;
3605 return true;
3608 /* Return true if LOOP contains phis with ADDR_EXPR in args. */
3610 static bool
3611 loop_has_phi_with_address_arg (class loop *loop)
3613 basic_block *bbs = get_loop_body (loop);
3614 bool res = false;
3616 unsigned i, j;
3617 gphi_iterator gsi;
3618 for (i = 0; i < loop->num_nodes; i++)
3619 for (gsi = gsi_start_phis (bbs[i]); !gsi_end_p (gsi); gsi_next (&gsi))
3621 gphi *phi = gsi.phi ();
3622 for (j = 0; j < gimple_phi_num_args (phi); j++)
3624 tree arg = gimple_phi_arg_def (phi, j);
3625 if (TREE_CODE (arg) == ADDR_EXPR)
3627 /* This should be handled by eliminate_local_variables, but that
3628 function currently ignores phis. */
3629 res = true;
3630 goto end;
3634 end:
3635 free (bbs);
3637 return res;
3640 /* Return true if memory ref REF (corresponding to the stmt at GSI in
3641 REGIONS_BB[I]) conflicts with the statements in REGIONS_BB[I] after gsi,
3642 or the statements in REGIONS_BB[I + n]. REF_IS_STORE indicates if REF is a
3643 store. Ignore conflicts with SKIP_STMT. */
3645 static bool
3646 ref_conflicts_with_region (gimple_stmt_iterator gsi, ao_ref *ref,
3647 bool ref_is_store, vec<basic_block> region_bbs,
3648 unsigned int i, gimple *skip_stmt)
3650 basic_block bb = region_bbs[i];
3651 gsi_next (&gsi);
3653 while (true)
3655 for (; !gsi_end_p (gsi);
3656 gsi_next (&gsi))
3658 gimple *stmt = gsi_stmt (gsi);
3659 if (stmt == skip_stmt)
3661 if (dump_file)
3663 fprintf (dump_file, "skipping reduction store: ");
3664 print_gimple_stmt (dump_file, stmt, 0);
3666 continue;
3669 if (!gimple_vdef (stmt)
3670 && !gimple_vuse (stmt))
3671 continue;
3673 if (gimple_code (stmt) == GIMPLE_RETURN)
3674 continue;
3676 if (ref_is_store)
3678 if (ref_maybe_used_by_stmt_p (stmt, ref))
3680 if (dump_file)
3682 fprintf (dump_file, "Stmt ");
3683 print_gimple_stmt (dump_file, stmt, 0);
3685 return true;
3688 else
3690 if (stmt_may_clobber_ref_p_1 (stmt, ref))
3692 if (dump_file)
3694 fprintf (dump_file, "Stmt ");
3695 print_gimple_stmt (dump_file, stmt, 0);
3697 return true;
3701 i++;
3702 if (i == region_bbs.length ())
3703 break;
3704 bb = region_bbs[i];
3705 gsi = gsi_start_bb (bb);
3708 return false;
3711 /* Return true if the bbs in REGION_BBS but not in in_loop_bbs can be executed
3712 in parallel with REGION_BBS containing the loop. Return the stores of
3713 reduction results in REDUCTION_STORES. */
3715 static bool
3716 oacc_entry_exit_ok_1 (bitmap in_loop_bbs, const vec<basic_block> &region_bbs,
3717 reduction_info_table_type *reduction_list,
3718 bitmap reduction_stores)
3720 tree omp_data_i = get_omp_data_i_param ();
3722 unsigned i;
3723 basic_block bb;
3724 FOR_EACH_VEC_ELT (region_bbs, i, bb)
3726 if (bitmap_bit_p (in_loop_bbs, bb->index))
3727 continue;
3729 gimple_stmt_iterator gsi;
3730 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi);
3731 gsi_next (&gsi))
3733 gimple *stmt = gsi_stmt (gsi);
3734 gimple *skip_stmt = NULL;
3736 if (is_gimple_debug (stmt)
3737 || gimple_code (stmt) == GIMPLE_COND)
3738 continue;
3740 ao_ref ref;
3741 bool ref_is_store = false;
3742 if (gimple_assign_load_p (stmt))
3744 tree rhs = gimple_assign_rhs1 (stmt);
3745 tree base = get_base_address (rhs);
3746 if (TREE_CODE (base) == MEM_REF
3747 && operand_equal_p (TREE_OPERAND (base, 0), omp_data_i, 0))
3748 continue;
3750 tree lhs = gimple_assign_lhs (stmt);
3751 if (TREE_CODE (lhs) == SSA_NAME
3752 && has_single_use (lhs))
3754 use_operand_p use_p;
3755 gimple *use_stmt;
3756 struct reduction_info *red;
3757 single_imm_use (lhs, &use_p, &use_stmt);
3758 if (gimple_code (use_stmt) == GIMPLE_PHI
3759 && (red = reduction_phi (reduction_list, use_stmt)))
3761 tree val = PHI_RESULT (red->keep_res);
3762 if (has_single_use (val))
3764 single_imm_use (val, &use_p, &use_stmt);
3765 if (gimple_store_p (use_stmt))
3767 unsigned int id
3768 = SSA_NAME_VERSION (gimple_vdef (use_stmt));
3769 bitmap_set_bit (reduction_stores, id);
3770 skip_stmt = use_stmt;
3771 if (dump_file)
3773 fprintf (dump_file, "found reduction load: ");
3774 print_gimple_stmt (dump_file, stmt, 0);
3781 ao_ref_init (&ref, rhs);
3783 else if (gimple_store_p (stmt))
3785 ao_ref_init (&ref, gimple_assign_lhs (stmt));
3786 ref_is_store = true;
3788 else if (gimple_code (stmt) == GIMPLE_OMP_RETURN)
3789 continue;
3790 else if (!gimple_has_side_effects (stmt)
3791 && !gimple_could_trap_p (stmt)
3792 && !stmt_could_throw_p (cfun, stmt)
3793 && !gimple_vdef (stmt)
3794 && !gimple_vuse (stmt))
3795 continue;
3796 else if (gimple_call_internal_p (stmt, IFN_GOACC_DIM_POS))
3797 continue;
3798 else if (gimple_code (stmt) == GIMPLE_RETURN)
3799 continue;
3800 else
3802 if (dump_file)
3804 fprintf (dump_file, "Unhandled stmt in entry/exit: ");
3805 print_gimple_stmt (dump_file, stmt, 0);
3807 return false;
3810 if (ref_conflicts_with_region (gsi, &ref, ref_is_store, region_bbs,
3811 i, skip_stmt))
3813 if (dump_file)
3815 fprintf (dump_file, "conflicts with entry/exit stmt: ");
3816 print_gimple_stmt (dump_file, stmt, 0);
3818 return false;
3823 return true;
3826 /* Find stores inside REGION_BBS and outside IN_LOOP_BBS, and guard them with
3827 gang_pos == 0, except when the stores are REDUCTION_STORES. Return true
3828 if any changes were made. */
3830 static bool
3831 oacc_entry_exit_single_gang (bitmap in_loop_bbs,
3832 const vec<basic_block> &region_bbs,
3833 bitmap reduction_stores)
3835 tree gang_pos = NULL_TREE;
3836 bool changed = false;
3838 unsigned i;
3839 basic_block bb;
3840 FOR_EACH_VEC_ELT (region_bbs, i, bb)
3842 if (bitmap_bit_p (in_loop_bbs, bb->index))
3843 continue;
3845 gimple_stmt_iterator gsi;
3846 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi);)
3848 gimple *stmt = gsi_stmt (gsi);
3850 if (!gimple_store_p (stmt))
3852 /* Update gsi to point to next stmt. */
3853 gsi_next (&gsi);
3854 continue;
3857 if (bitmap_bit_p (reduction_stores,
3858 SSA_NAME_VERSION (gimple_vdef (stmt))))
3860 if (dump_file)
3862 fprintf (dump_file,
3863 "skipped reduction store for single-gang"
3864 " neutering: ");
3865 print_gimple_stmt (dump_file, stmt, 0);
3868 /* Update gsi to point to next stmt. */
3869 gsi_next (&gsi);
3870 continue;
3873 changed = true;
3875 if (gang_pos == NULL_TREE)
3877 tree arg = build_int_cst (integer_type_node, GOMP_DIM_GANG);
3878 gcall *gang_single
3879 = gimple_build_call_internal (IFN_GOACC_DIM_POS, 1, arg);
3880 gang_pos = make_ssa_name (integer_type_node);
3881 gimple_call_set_lhs (gang_single, gang_pos);
3882 gimple_stmt_iterator start
3883 = gsi_start_bb (single_succ (ENTRY_BLOCK_PTR_FOR_FN (cfun)));
3884 tree vuse = ssa_default_def (cfun, gimple_vop (cfun));
3885 gimple_set_vuse (gang_single, vuse);
3886 gsi_insert_before (&start, gang_single, GSI_SAME_STMT);
3889 if (dump_file)
3891 fprintf (dump_file,
3892 "found store that needs single-gang neutering: ");
3893 print_gimple_stmt (dump_file, stmt, 0);
3897 /* Split block before store. */
3898 gimple_stmt_iterator gsi2 = gsi;
3899 gsi_prev (&gsi2);
3900 edge e;
3901 if (gsi_end_p (gsi2))
3903 e = split_block_after_labels (bb);
3904 gsi2 = gsi_last_bb (bb);
3906 else
3907 e = split_block (bb, gsi_stmt (gsi2));
3908 basic_block bb2 = e->dest;
3910 /* Split block after store. */
3911 gimple_stmt_iterator gsi3 = gsi_start_bb (bb2);
3912 edge e2 = split_block (bb2, gsi_stmt (gsi3));
3913 basic_block bb3 = e2->dest;
3915 gimple *cond
3916 = gimple_build_cond (EQ_EXPR, gang_pos, integer_zero_node,
3917 NULL_TREE, NULL_TREE);
3918 gsi_insert_after (&gsi2, cond, GSI_NEW_STMT);
3920 edge e3 = make_edge (bb, bb3, EDGE_FALSE_VALUE);
3921 /* FIXME: What is the probability? */
3922 e3->probability = profile_probability::guessed_never ();
3923 e->flags = EDGE_TRUE_VALUE;
3925 tree vdef = gimple_vdef (stmt);
3926 tree vuse = gimple_vuse (stmt);
3928 tree phi_res = copy_ssa_name (vdef);
3929 gphi *new_phi = create_phi_node (phi_res, bb3);
3930 replace_uses_by (vdef, phi_res);
3931 add_phi_arg (new_phi, vuse, e3, UNKNOWN_LOCATION);
3932 add_phi_arg (new_phi, vdef, e2, UNKNOWN_LOCATION);
3934 /* Update gsi to point to next stmt. */
3935 bb = bb3;
3936 gsi = gsi_start_bb (bb);
3941 return changed;
3944 /* Return true if the statements before and after the LOOP can be executed in
3945 parallel with the function containing the loop. Resolve conflicting stores
3946 outside LOOP by guarding them such that only a single gang executes them. */
3948 static bool
3949 oacc_entry_exit_ok (class loop *loop,
3950 reduction_info_table_type *reduction_list)
3952 basic_block *loop_bbs = get_loop_body_in_dom_order (loop);
3953 auto_vec<basic_block> region_bbs
3954 = get_all_dominated_blocks (CDI_DOMINATORS, ENTRY_BLOCK_PTR_FOR_FN (cfun));
3956 bitmap in_loop_bbs = BITMAP_ALLOC (NULL);
3957 bitmap_clear (in_loop_bbs);
3958 for (unsigned int i = 0; i < loop->num_nodes; i++)
3959 bitmap_set_bit (in_loop_bbs, loop_bbs[i]->index);
3961 bitmap reduction_stores = BITMAP_ALLOC (NULL);
3962 bool res = oacc_entry_exit_ok_1 (in_loop_bbs, region_bbs, reduction_list,
3963 reduction_stores);
3965 if (res)
3967 bool changed = oacc_entry_exit_single_gang (in_loop_bbs, region_bbs,
3968 reduction_stores);
3969 if (changed)
3971 free_dominance_info (CDI_DOMINATORS);
3972 calculate_dominance_info (CDI_DOMINATORS);
3976 free (loop_bbs);
3978 BITMAP_FREE (in_loop_bbs);
3979 BITMAP_FREE (reduction_stores);
3981 return res;
3984 /* Detect parallel loops and generate parallel code using libgomp
3985 primitives. Returns true if some loop was parallelized, false
3986 otherwise. */
3988 static bool
3989 parallelize_loops (bool oacc_kernels_p)
3991 unsigned n_threads;
3992 bool changed = false;
3993 class loop *skip_loop = NULL;
3994 class tree_niter_desc niter_desc;
3995 struct obstack parloop_obstack;
3996 HOST_WIDE_INT estimated;
3998 /* Do not parallelize loops in the functions created by parallelization. */
3999 if (!oacc_kernels_p
4000 && parallelized_function_p (cfun->decl))
4001 return false;
4003 /* Do not parallelize loops in offloaded functions. */
4004 if (!oacc_kernels_p
4005 && oacc_get_fn_attrib (cfun->decl) != NULL)
4006 return false;
4008 if (cfun->has_nonlocal_label)
4009 return false;
4011 /* For OpenACC kernels, n_threads will be determined later; otherwise, it's
4012 the argument to -ftree-parallelize-loops. */
4013 if (oacc_kernels_p)
4014 n_threads = 0;
4015 else
4016 n_threads = flag_tree_parallelize_loops;
4018 gcc_obstack_init (&parloop_obstack);
4019 reduction_info_table_type reduction_list (10);
4021 calculate_dominance_info (CDI_DOMINATORS);
4023 for (auto loop : loops_list (cfun, 0))
4025 if (loop == skip_loop)
4027 if (!loop->in_oacc_kernels_region
4028 && dump_file && (dump_flags & TDF_DETAILS))
4029 fprintf (dump_file,
4030 "Skipping loop %d as inner loop of parallelized loop\n",
4031 loop->num);
4033 skip_loop = loop->inner;
4034 continue;
4036 else
4037 skip_loop = NULL;
4039 reduction_list.empty ();
4041 if (oacc_kernels_p)
4043 if (!loop->in_oacc_kernels_region)
4044 continue;
4046 /* Don't try to parallelize inner loops in an oacc kernels region. */
4047 if (loop->inner)
4048 skip_loop = loop->inner;
4050 if (dump_file && (dump_flags & TDF_DETAILS))
4051 fprintf (dump_file,
4052 "Trying loop %d with header bb %d in oacc kernels"
4053 " region\n", loop->num, loop->header->index);
4056 if (dump_file && (dump_flags & TDF_DETAILS))
4058 fprintf (dump_file, "Trying loop %d as candidate\n",loop->num);
4059 if (loop->inner)
4060 fprintf (dump_file, "loop %d is not innermost\n",loop->num);
4061 else
4062 fprintf (dump_file, "loop %d is innermost\n",loop->num);
4065 if (!single_dom_exit (loop))
4068 if (dump_file && (dump_flags & TDF_DETAILS))
4069 fprintf (dump_file, "loop is !single_dom_exit\n");
4071 continue;
4074 if (/* And of course, the loop must be parallelizable. */
4075 !can_duplicate_loop_p (loop)
4076 || loop_has_blocks_with_irreducible_flag (loop)
4077 || (loop_preheader_edge (loop)->src->flags & BB_IRREDUCIBLE_LOOP)
4078 /* FIXME: the check for vector phi nodes could be removed. */
4079 || loop_has_vector_phi_nodes (loop))
4080 continue;
4082 estimated = estimated_loop_iterations_int (loop);
4083 if (estimated == -1)
4084 estimated = get_likely_max_loop_iterations_int (loop);
4085 /* FIXME: Bypass this check as graphite doesn't update the
4086 count and frequency correctly now. */
4087 if (!flag_loop_parallelize_all
4088 && !oacc_kernels_p
4089 && ((estimated != -1
4090 && (estimated
4091 < ((HOST_WIDE_INT) n_threads
4092 * (loop->inner ? 2 : MIN_PER_THREAD) - 1)))
4093 /* Do not bother with loops in cold areas. */
4094 || optimize_loop_nest_for_size_p (loop)))
4095 continue;
4097 if (!try_get_loop_niter (loop, &niter_desc))
4098 continue;
4100 if (!try_create_reduction_list (loop, &reduction_list, oacc_kernels_p))
4101 continue;
4103 if (loop_has_phi_with_address_arg (loop))
4104 continue;
4106 if (!loop->can_be_parallel
4107 && !loop_parallel_p (loop, &parloop_obstack))
4108 continue;
4110 if (oacc_kernels_p
4111 && !oacc_entry_exit_ok (loop, &reduction_list))
4113 if (dump_file)
4114 fprintf (dump_file, "entry/exit not ok: FAILED\n");
4115 continue;
4118 changed = true;
4119 skip_loop = loop->inner;
4121 if (dump_enabled_p ())
4123 dump_user_location_t loop_loc = find_loop_location (loop);
4124 if (loop->inner)
4125 dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, loop_loc,
4126 "parallelizing outer loop %d\n", loop->num);
4127 else
4128 dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, loop_loc,
4129 "parallelizing inner loop %d\n", loop->num);
4132 gen_parallel_loop (loop, &reduction_list,
4133 n_threads, &niter_desc, oacc_kernels_p);
4136 obstack_free (&parloop_obstack, NULL);
4138 /* Parallelization will cause new function calls to be inserted through
4139 which local variables will escape. Reset the points-to solution
4140 for ESCAPED. */
4141 if (changed)
4142 pt_solution_reset (&cfun->gimple_df->escaped);
4144 return changed;
4147 /* Parallelization. */
4149 namespace {
4151 const pass_data pass_data_parallelize_loops =
4153 GIMPLE_PASS, /* type */
4154 "parloops", /* name */
4155 OPTGROUP_LOOP, /* optinfo_flags */
4156 TV_TREE_PARALLELIZE_LOOPS, /* tv_id */
4157 ( PROP_cfg | PROP_ssa ), /* properties_required */
4158 0, /* properties_provided */
4159 0, /* properties_destroyed */
4160 0, /* todo_flags_start */
4161 0, /* todo_flags_finish */
4164 class pass_parallelize_loops : public gimple_opt_pass
4166 public:
4167 pass_parallelize_loops (gcc::context *ctxt)
4168 : gimple_opt_pass (pass_data_parallelize_loops, ctxt),
4169 oacc_kernels_p (false)
4172 /* opt_pass methods: */
4173 virtual bool gate (function *)
4175 if (oacc_kernels_p)
4176 return flag_openacc;
4177 else
4178 return flag_tree_parallelize_loops > 1;
4180 virtual unsigned int execute (function *);
4181 opt_pass * clone () { return new pass_parallelize_loops (m_ctxt); }
4182 void set_pass_param (unsigned int n, bool param)
4184 gcc_assert (n == 0);
4185 oacc_kernels_p = param;
4188 private:
4189 bool oacc_kernels_p;
4190 }; // class pass_parallelize_loops
4192 unsigned
4193 pass_parallelize_loops::execute (function *fun)
4195 tree nthreads = builtin_decl_explicit (BUILT_IN_OMP_GET_NUM_THREADS);
4196 if (nthreads == NULL_TREE)
4197 return 0;
4199 bool in_loop_pipeline = scev_initialized_p ();
4200 if (!in_loop_pipeline)
4201 loop_optimizer_init (LOOPS_NORMAL
4202 | LOOPS_HAVE_RECORDED_EXITS);
4204 if (number_of_loops (fun) <= 1)
4205 return 0;
4207 if (!in_loop_pipeline)
4209 rewrite_into_loop_closed_ssa (NULL, TODO_update_ssa);
4210 scev_initialize ();
4213 unsigned int todo = 0;
4214 if (parallelize_loops (oacc_kernels_p))
4216 fun->curr_properties &= ~(PROP_gimple_eomp);
4218 checking_verify_loop_structure ();
4220 todo |= TODO_update_ssa;
4223 if (!in_loop_pipeline)
4225 scev_finalize ();
4226 loop_optimizer_finalize ();
4229 return todo;
4232 } // anon namespace
4234 gimple_opt_pass *
4235 make_pass_parallelize_loops (gcc::context *ctxt)
4237 return new pass_parallelize_loops (ctxt);