1 /* Induction variable canonicalization and loop peeling.
2 Copyright (C) 2004-2014 Free Software Foundation, Inc.
4 This file is part of GCC.
6 GCC is free software; you can redistribute it and/or modify it
7 under the terms of the GNU General Public License as published by the
8 Free Software Foundation; either version 3, or (at your option) any
11 GCC is distributed in the hope that it will be useful, but WITHOUT
12 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING3. If not see
18 <http://www.gnu.org/licenses/>. */
20 /* This pass detects the loops that iterate a constant number of times,
21 adds a canonical induction variable (step -1, tested against 0)
22 and replaces the exit test. This enables the less powerful rtl
23 level analysis to use this information.
25 This might spoil the code in some cases (by increasing register pressure).
26 Note that in the case the new variable is not needed, ivopts will get rid
27 of it, so it might only be a problem when there are no other linear induction
28 variables. In that case the created optimization possibilities are likely
32 - complete unrolling (or peeling) when the loops is rolling few enough
34 - simple peeling (i.e. copying few initial iterations prior the loop)
35 when number of iteration estimate is known (typically by the profile
40 #include "coretypes.h"
50 #include "hard-reg-set.h"
53 #include "dominance.h"
55 #include "basic-block.h"
56 #include "gimple-pretty-print.h"
57 #include "tree-ssa-alias.h"
58 #include "internal-fn.h"
59 #include "gimple-fold.h"
61 #include "gimple-expr.h"
64 #include "gimple-iterator.h"
65 #include "gimple-ssa.h"
67 #include "plugin-api.h"
71 #include "tree-phinodes.h"
72 #include "ssa-iterators.h"
73 #include "stringpool.h"
74 #include "tree-ssanames.h"
75 #include "tree-ssa-loop-manip.h"
76 #include "tree-ssa-loop-niter.h"
77 #include "tree-ssa-loop.h"
78 #include "tree-into-ssa.h"
80 #include "tree-pass.h"
81 #include "tree-chrec.h"
82 #include "tree-scalar-evolution.h"
85 #include "tree-inline.h"
87 #include "tree-cfgcleanup.h"
90 /* Specifies types of loops that may be unrolled. */
94 UL_SINGLE_ITER
, /* Only loops that exit immediately in the first
96 UL_NO_GROWTH
, /* Only loops whose unrolling will not cause increase
98 UL_ALL
/* All suitable loops. */
101 /* Adds a canonical induction variable to LOOP iterating NITER times. EXIT
102 is the exit edge whose condition is replaced. */
105 create_canonical_iv (struct loop
*loop
, edge exit
, tree niter
)
110 gimple_stmt_iterator incr_at
;
113 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
115 fprintf (dump_file
, "Added canonical iv to loop %d, ", loop
->num
);
116 print_generic_expr (dump_file
, niter
, TDF_SLIM
);
117 fprintf (dump_file
, " iterations.\n");
120 cond
= last_stmt (exit
->src
);
121 in
= EDGE_SUCC (exit
->src
, 0);
123 in
= EDGE_SUCC (exit
->src
, 1);
125 /* Note that we do not need to worry about overflows, since
126 type of niter is always unsigned and all comparisons are
127 just for equality/nonequality -- i.e. everything works
128 with a modulo arithmetics. */
130 type
= TREE_TYPE (niter
);
131 niter
= fold_build2 (PLUS_EXPR
, type
,
133 build_int_cst (type
, 1));
134 incr_at
= gsi_last_bb (in
->src
);
136 build_int_cst (type
, -1),
138 &incr_at
, false, NULL
, &var
);
140 cmp
= (exit
->flags
& EDGE_TRUE_VALUE
) ? EQ_EXPR
: NE_EXPR
;
141 gimple_cond_set_code (cond
, cmp
);
142 gimple_cond_set_lhs (cond
, var
);
143 gimple_cond_set_rhs (cond
, build_int_cst (type
, 0));
147 /* Describe size of loop as detected by tree_estimate_loop_size. */
150 /* Number of instructions in the loop. */
153 /* Number of instructions that will be likely optimized out in
154 peeled iterations of loop (i.e. computation based on induction
155 variable where induction variable starts at known constant.) */
156 int eliminated_by_peeling
;
158 /* Same statistics for last iteration of loop: it is smaller because
159 instructions after exit are not executed. */
161 int last_iteration_eliminated_by_peeling
;
163 /* If some IV computation will become constant. */
166 /* Number of call stmts that are not a builtin and are pure or const
167 present on the hot path. */
168 int num_pure_calls_on_hot_path
;
169 /* Number of call stmts that are not a builtin and are not pure nor const
170 present on the hot path. */
171 int num_non_pure_calls_on_hot_path
;
172 /* Number of statements other than calls in the loop. */
173 int non_call_stmts_on_hot_path
;
174 /* Number of branches seen on the hot path. */
175 int num_branches_on_hot_path
;
178 /* Return true if OP in STMT will be constant after peeling LOOP. */
181 constant_after_peeling (tree op
, gimple stmt
, struct loop
*loop
)
185 if (is_gimple_min_invariant (op
))
188 /* We can still fold accesses to constant arrays when index is known. */
189 if (TREE_CODE (op
) != SSA_NAME
)
193 /* First make fast look if we see constant array inside. */
194 while (handled_component_p (base
))
195 base
= TREE_OPERAND (base
, 0);
197 && ctor_for_folding (base
) != error_mark_node
)
198 || CONSTANT_CLASS_P (base
))
200 /* If so, see if we understand all the indices. */
202 while (handled_component_p (base
))
204 if (TREE_CODE (base
) == ARRAY_REF
205 && !constant_after_peeling (TREE_OPERAND (base
, 1), stmt
, loop
))
207 base
= TREE_OPERAND (base
, 0);
214 /* Induction variables are constants. */
215 if (!simple_iv (loop
, loop_containing_stmt (stmt
), op
, &iv
, false))
217 if (!is_gimple_min_invariant (iv
.base
))
219 if (!is_gimple_min_invariant (iv
.step
))
224 /* Computes an estimated number of insns in LOOP.
225 EXIT (if non-NULL) is an exite edge that will be eliminated in all but last
226 iteration of the loop.
227 EDGE_TO_CANCEL (if non-NULL) is an non-exit edge eliminated in the last iteration
229 Return results in SIZE, estimate benefits for complete unrolling exiting by EXIT.
230 Stop estimating after UPPER_BOUND is met. Return true in this case. */
233 tree_estimate_loop_size (struct loop
*loop
, edge exit
, edge edge_to_cancel
, struct loop_size
*size
,
236 basic_block
*body
= get_loop_body (loop
);
237 gimple_stmt_iterator gsi
;
240 vec
<basic_block
> path
= get_loop_hot_path (loop
);
243 size
->eliminated_by_peeling
= 0;
244 size
->last_iteration
= 0;
245 size
->last_iteration_eliminated_by_peeling
= 0;
246 size
->num_pure_calls_on_hot_path
= 0;
247 size
->num_non_pure_calls_on_hot_path
= 0;
248 size
->non_call_stmts_on_hot_path
= 0;
249 size
->num_branches_on_hot_path
= 0;
250 size
->constant_iv
= 0;
252 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
253 fprintf (dump_file
, "Estimating sizes for loop %i\n", loop
->num
);
254 for (i
= 0; i
< loop
->num_nodes
; i
++)
256 if (edge_to_cancel
&& body
[i
] != edge_to_cancel
->src
257 && dominated_by_p (CDI_DOMINATORS
, body
[i
], edge_to_cancel
->src
))
261 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
262 fprintf (dump_file
, " BB: %i, after_exit: %i\n", body
[i
]->index
, after_exit
);
264 for (gsi
= gsi_start_bb (body
[i
]); !gsi_end_p (gsi
); gsi_next (&gsi
))
266 gimple stmt
= gsi_stmt (gsi
);
267 int num
= estimate_num_insns (stmt
, &eni_size_weights
);
268 bool likely_eliminated
= false;
269 bool likely_eliminated_last
= false;
270 bool likely_eliminated_peeled
= false;
272 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
274 fprintf (dump_file
, " size: %3i ", num
);
275 print_gimple_stmt (dump_file
, gsi_stmt (gsi
), 0, 0);
278 /* Look for reasons why we might optimize this stmt away. */
280 if (gimple_has_side_effects (stmt
))
282 /* Exit conditional. */
283 else if (exit
&& body
[i
] == exit
->src
284 && stmt
== last_stmt (exit
->src
))
286 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
287 fprintf (dump_file
, " Exit condition will be eliminated "
288 "in peeled copies.\n");
289 likely_eliminated_peeled
= true;
291 else if (edge_to_cancel
&& body
[i
] == edge_to_cancel
->src
292 && stmt
== last_stmt (edge_to_cancel
->src
))
294 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
295 fprintf (dump_file
, " Exit condition will be eliminated "
297 likely_eliminated_last
= true;
299 /* Sets of IV variables */
300 else if (gimple_code (stmt
) == GIMPLE_ASSIGN
301 && constant_after_peeling (gimple_assign_lhs (stmt
), stmt
, loop
))
303 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
304 fprintf (dump_file
, " Induction variable computation will"
305 " be folded away.\n");
306 likely_eliminated
= true;
308 /* Assignments of IV variables. */
309 else if (gimple_code (stmt
) == GIMPLE_ASSIGN
310 && TREE_CODE (gimple_assign_lhs (stmt
)) == SSA_NAME
311 && constant_after_peeling (gimple_assign_rhs1 (stmt
), stmt
, loop
)
312 && (gimple_assign_rhs_class (stmt
) != GIMPLE_BINARY_RHS
313 || constant_after_peeling (gimple_assign_rhs2 (stmt
),
316 size
->constant_iv
= true;
317 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
318 fprintf (dump_file
, " Constant expression will be folded away.\n");
319 likely_eliminated
= true;
322 else if ((gimple_code (stmt
) == GIMPLE_COND
323 && constant_after_peeling (gimple_cond_lhs (stmt
), stmt
, loop
)
324 && constant_after_peeling (gimple_cond_rhs (stmt
), stmt
, loop
))
325 || (gimple_code (stmt
) == GIMPLE_SWITCH
326 && constant_after_peeling (gimple_switch_index (stmt
), stmt
, loop
)))
328 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
329 fprintf (dump_file
, " Constant conditional.\n");
330 likely_eliminated
= true;
333 size
->overall
+= num
;
334 if (likely_eliminated
|| likely_eliminated_peeled
)
335 size
->eliminated_by_peeling
+= num
;
338 size
->last_iteration
+= num
;
339 if (likely_eliminated
|| likely_eliminated_last
)
340 size
->last_iteration_eliminated_by_peeling
+= num
;
342 if ((size
->overall
* 3 / 2 - size
->eliminated_by_peeling
343 - size
->last_iteration_eliminated_by_peeling
) > upper_bound
)
351 while (path
.length ())
353 basic_block bb
= path
.pop ();
354 for (gsi
= gsi_start_bb (bb
); !gsi_end_p (gsi
); gsi_next (&gsi
))
356 gimple stmt
= gsi_stmt (gsi
);
357 if (gimple_code (stmt
) == GIMPLE_CALL
)
359 int flags
= gimple_call_flags (stmt
);
360 tree decl
= gimple_call_fndecl (stmt
);
362 if (decl
&& DECL_IS_BUILTIN (decl
)
363 && is_inexpensive_builtin (decl
))
365 else if (flags
& (ECF_PURE
| ECF_CONST
))
366 size
->num_pure_calls_on_hot_path
++;
368 size
->num_non_pure_calls_on_hot_path
++;
369 size
->num_branches_on_hot_path
++;
371 else if (gimple_code (stmt
) != GIMPLE_CALL
372 && gimple_code (stmt
) != GIMPLE_DEBUG
)
373 size
->non_call_stmts_on_hot_path
++;
374 if (((gimple_code (stmt
) == GIMPLE_COND
375 && (!constant_after_peeling (gimple_cond_lhs (stmt
), stmt
, loop
)
376 || constant_after_peeling (gimple_cond_rhs (stmt
), stmt
, loop
)))
377 || (gimple_code (stmt
) == GIMPLE_SWITCH
378 && !constant_after_peeling (gimple_switch_index (stmt
), stmt
, loop
)))
379 && (!exit
|| bb
!= exit
->src
))
380 size
->num_branches_on_hot_path
++;
384 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
385 fprintf (dump_file
, "size: %i-%i, last_iteration: %i-%i\n", size
->overall
,
386 size
->eliminated_by_peeling
, size
->last_iteration
,
387 size
->last_iteration_eliminated_by_peeling
);
393 /* Estimate number of insns of completely unrolled loop.
394 It is (NUNROLL + 1) * size of loop body with taking into account
395 the fact that in last copy everything after exit conditional
396 is dead and that some instructions will be eliminated after
399 Loop body is likely going to simplify further, this is difficult
400 to guess, we just decrease the result by 1/3. */
402 static unsigned HOST_WIDE_INT
403 estimated_unrolled_size (struct loop_size
*size
,
404 unsigned HOST_WIDE_INT nunroll
)
406 HOST_WIDE_INT unr_insns
= ((nunroll
)
407 * (HOST_WIDE_INT
) (size
->overall
408 - size
->eliminated_by_peeling
));
411 unr_insns
+= size
->last_iteration
- size
->last_iteration_eliminated_by_peeling
;
413 unr_insns
= unr_insns
* 2 / 3;
420 /* Loop LOOP is known to not loop. See if there is an edge in the loop
421 body that can be remove to make the loop to always exit and at
422 the same time it does not make any code potentially executed
423 during the last iteration dead.
425 After complete unrolling we still may get rid of the conditional
426 on the exit in the last copy even if we have no idea what it does.
427 This is quite common case for loops of form
433 Here we prove the loop to iterate 5 times but we do not know
434 it from induction variable.
436 For now we handle only simple case where there is exit condition
437 just before the latch block and the latch block contains no statements
438 with side effect that may otherwise terminate the execution of loop
439 (such as by EH or by terminating the program or longjmp).
441 In the general case we may want to cancel the paths leading to statements
442 loop-niter identified as having undefined effect in the last iteration.
443 The other cases are hopefully rare and will be cleaned up later. */
446 loop_edge_to_cancel (struct loop
*loop
)
451 gimple_stmt_iterator gsi
;
453 /* We want only one predecestor of the loop. */
454 if (EDGE_COUNT (loop
->latch
->preds
) > 1)
457 exits
= get_loop_exit_edges (loop
);
459 FOR_EACH_VEC_ELT (exits
, i
, edge_to_cancel
)
461 /* Find the other edge than the loop exit
462 leaving the conditoinal. */
463 if (EDGE_COUNT (edge_to_cancel
->src
->succs
) != 2)
465 if (EDGE_SUCC (edge_to_cancel
->src
, 0) == edge_to_cancel
)
466 edge_to_cancel
= EDGE_SUCC (edge_to_cancel
->src
, 1);
468 edge_to_cancel
= EDGE_SUCC (edge_to_cancel
->src
, 0);
470 /* We only can handle conditionals. */
471 if (!(edge_to_cancel
->flags
& (EDGE_TRUE_VALUE
| EDGE_FALSE_VALUE
)))
474 /* We should never have conditionals in the loop latch. */
475 gcc_assert (edge_to_cancel
->dest
!= loop
->header
);
477 /* Check that it leads to loop latch. */
478 if (edge_to_cancel
->dest
!= loop
->latch
)
483 /* Verify that the code in loop latch does nothing that may end program
484 execution without really reaching the exit. This may include
485 non-pure/const function calls, EH statements, volatile ASMs etc. */
486 for (gsi
= gsi_start_bb (loop
->latch
); !gsi_end_p (gsi
); gsi_next (&gsi
))
487 if (gimple_has_side_effects (gsi_stmt (gsi
)))
489 return edge_to_cancel
;
495 /* Remove all tests for exits that are known to be taken after LOOP was
496 peeled NPEELED times. Put gcc_unreachable before every statement
497 known to not be executed. */
500 remove_exits_and_undefined_stmts (struct loop
*loop
, unsigned int npeeled
)
502 struct nb_iter_bound
*elt
;
503 bool changed
= false;
505 for (elt
= loop
->bounds
; elt
; elt
= elt
->next
)
507 /* If statement is known to be undefined after peeling, turn it
508 into unreachable (or trap when debugging experience is supposed
511 && wi::ltu_p (elt
->bound
, npeeled
))
513 gimple_stmt_iterator gsi
= gsi_for_stmt (elt
->stmt
);
514 gimple stmt
= gimple_build_call
515 (builtin_decl_implicit (BUILT_IN_UNREACHABLE
), 0);
517 gimple_set_location (stmt
, gimple_location (elt
->stmt
));
518 gsi_insert_before (&gsi
, stmt
, GSI_NEW_STMT
);
520 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
522 fprintf (dump_file
, "Forced statement unreachable: ");
523 print_gimple_stmt (dump_file
, elt
->stmt
, 0, 0);
526 /* If we know the exit will be taken after peeling, update. */
527 else if (elt
->is_exit
528 && wi::leu_p (elt
->bound
, npeeled
))
530 basic_block bb
= gimple_bb (elt
->stmt
);
531 edge exit_edge
= EDGE_SUCC (bb
, 0);
533 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
535 fprintf (dump_file
, "Forced exit to be taken: ");
536 print_gimple_stmt (dump_file
, elt
->stmt
, 0, 0);
538 if (!loop_exit_edge_p (loop
, exit_edge
))
539 exit_edge
= EDGE_SUCC (bb
, 1);
540 gcc_checking_assert (loop_exit_edge_p (loop
, exit_edge
));
541 if (exit_edge
->flags
& EDGE_TRUE_VALUE
)
542 gimple_cond_make_true (elt
->stmt
);
544 gimple_cond_make_false (elt
->stmt
);
545 update_stmt (elt
->stmt
);
552 /* Remove all exits that are known to be never taken because of the loop bound
556 remove_redundant_iv_tests (struct loop
*loop
)
558 struct nb_iter_bound
*elt
;
559 bool changed
= false;
561 if (!loop
->any_upper_bound
)
563 for (elt
= loop
->bounds
; elt
; elt
= elt
->next
)
565 /* Exit is pointless if it won't be taken before loop reaches
567 if (elt
->is_exit
&& loop
->any_upper_bound
568 && wi::ltu_p (loop
->nb_iterations_upper_bound
, elt
->bound
))
570 basic_block bb
= gimple_bb (elt
->stmt
);
571 edge exit_edge
= EDGE_SUCC (bb
, 0);
572 struct tree_niter_desc niter
;
574 if (!loop_exit_edge_p (loop
, exit_edge
))
575 exit_edge
= EDGE_SUCC (bb
, 1);
577 /* Only when we know the actual number of iterations, not
578 just a bound, we can remove the exit. */
579 if (!number_of_iterations_exit (loop
, exit_edge
,
580 &niter
, false, false)
581 || !integer_onep (niter
.assumptions
)
582 || !integer_zerop (niter
.may_be_zero
)
584 || TREE_CODE (niter
.niter
) != INTEGER_CST
585 || !wi::ltu_p (loop
->nb_iterations_upper_bound
,
586 wi::to_widest (niter
.niter
)))
589 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
591 fprintf (dump_file
, "Removed pointless exit: ");
592 print_gimple_stmt (dump_file
, elt
->stmt
, 0, 0);
594 if (exit_edge
->flags
& EDGE_TRUE_VALUE
)
595 gimple_cond_make_false (elt
->stmt
);
597 gimple_cond_make_true (elt
->stmt
);
598 update_stmt (elt
->stmt
);
605 /* Stores loops that will be unlooped after we process whole loop tree. */
606 static vec
<loop_p
> loops_to_unloop
;
607 static vec
<int> loops_to_unloop_nunroll
;
609 /* Cancel all fully unrolled loops by putting __builtin_unreachable
611 We do it after all unrolling since unlooping moves basic blocks
612 across loop boundaries trashing loop closed SSA form as well
613 as SCEV info needed to be intact during unrolling.
615 IRRED_INVALIDATED is used to bookkeep if information about
616 irreducible regions may become invalid as a result
617 of the transformation.
618 LOOP_CLOSED_SSA_INVALIDATED is used to bookkepp the case
619 when we need to go into loop closed SSA form. */
622 unloop_loops (bitmap loop_closed_ssa_invalidated
,
623 bool *irred_invalidated
)
625 while (loops_to_unloop
.length ())
627 struct loop
*loop
= loops_to_unloop
.pop ();
628 int n_unroll
= loops_to_unloop_nunroll
.pop ();
629 basic_block latch
= loop
->latch
;
630 edge latch_edge
= loop_latch_edge (loop
);
631 int flags
= latch_edge
->flags
;
632 location_t locus
= latch_edge
->goto_locus
;
634 gimple_stmt_iterator gsi
;
636 remove_exits_and_undefined_stmts (loop
, n_unroll
);
638 /* Unloop destroys the latch edge. */
639 unloop (loop
, irred_invalidated
, loop_closed_ssa_invalidated
);
641 /* Create new basic block for the latch edge destination and wire
643 stmt
= gimple_build_call (builtin_decl_implicit (BUILT_IN_UNREACHABLE
), 0);
644 latch_edge
= make_edge (latch
, create_basic_block (NULL
, NULL
, latch
), flags
);
645 latch_edge
->probability
= 0;
646 latch_edge
->count
= 0;
647 latch_edge
->flags
|= flags
;
648 latch_edge
->goto_locus
= locus
;
650 latch_edge
->dest
->loop_father
= current_loops
->tree_root
;
651 latch_edge
->dest
->count
= 0;
652 latch_edge
->dest
->frequency
= 0;
653 set_immediate_dominator (CDI_DOMINATORS
, latch_edge
->dest
, latch_edge
->src
);
655 gsi
= gsi_start_bb (latch_edge
->dest
);
656 gsi_insert_after (&gsi
, stmt
, GSI_NEW_STMT
);
658 loops_to_unloop
.release ();
659 loops_to_unloop_nunroll
.release ();
662 /* Tries to unroll LOOP completely, i.e. NITER times.
663 UL determines which loops we are allowed to unroll.
664 EXIT is the exit of the loop that should be eliminated.
665 MAXITER specfy bound on number of iterations, -1 if it is
666 not known or too large for HOST_WIDE_INT. The location
667 LOCUS corresponding to the loop is used when emitting
668 a summary of the unroll to the dump file. */
671 try_unroll_loop_completely (struct loop
*loop
,
672 edge exit
, tree niter
,
673 enum unroll_level ul
,
674 HOST_WIDE_INT maxiter
,
677 unsigned HOST_WIDE_INT n_unroll
= 0, ninsns
, unr_insns
;
679 struct loop_size size
;
680 bool n_unroll_found
= false;
681 edge edge_to_cancel
= NULL
;
682 int report_flags
= MSG_OPTIMIZED_LOCATIONS
| TDF_RTL
| TDF_DETAILS
;
684 /* See if we proved number of iterations to be low constant.
686 EXIT is an edge that will be removed in all but last iteration of
689 EDGE_TO_CACNEL is an edge that will be removed from the last iteration
690 of the unrolled sequence and is expected to make the final loop not
693 If the number of execution of loop is determined by standard induction
694 variable test, then EXIT and EDGE_TO_CANCEL are the two edges leaving
696 if (tree_fits_uhwi_p (niter
))
698 n_unroll
= tree_to_uhwi (niter
);
699 n_unroll_found
= true;
700 edge_to_cancel
= EDGE_SUCC (exit
->src
, 0);
701 if (edge_to_cancel
== exit
)
702 edge_to_cancel
= EDGE_SUCC (exit
->src
, 1);
704 /* We do not know the number of iterations and thus we can not eliminate
709 /* See if we can improve our estimate by using recorded loop bounds. */
711 && (!n_unroll_found
|| (unsigned HOST_WIDE_INT
)maxiter
< n_unroll
))
714 n_unroll_found
= true;
715 /* Loop terminates before the IV variable test, so we can not
716 remove it in the last iteration. */
717 edge_to_cancel
= NULL
;
723 if (n_unroll
> (unsigned) PARAM_VALUE (PARAM_MAX_COMPLETELY_PEEL_TIMES
))
725 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
726 fprintf (dump_file
, "Not unrolling loop %d "
727 "(--param max-completely-peeled-times limit reached).\n",
733 edge_to_cancel
= loop_edge_to_cancel (loop
);
741 vec
<edge
> to_remove
= vNULL
;
742 if (ul
== UL_SINGLE_ITER
)
745 large
= tree_estimate_loop_size
746 (loop
, exit
, edge_to_cancel
, &size
,
747 PARAM_VALUE (PARAM_MAX_COMPLETELY_PEELED_INSNS
));
748 ninsns
= size
.overall
;
751 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
752 fprintf (dump_file
, "Not unrolling loop %d: it is too large.\n",
757 unr_insns
= estimated_unrolled_size (&size
, n_unroll
);
758 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
760 fprintf (dump_file
, " Loop size: %d\n", (int) ninsns
);
761 fprintf (dump_file
, " Estimated size after unrolling: %d\n",
765 /* If the code is going to shrink, we don't need to be extra cautious
766 on guessing if the unrolling is going to be profitable. */
768 /* If there is IV variable that will become constant, we save
769 one instruction in the loop prologue we do not account
771 <= ninsns
+ (size
.constant_iv
!= false))
773 /* We unroll only inner loops, because we do not consider it profitable
774 otheriwse. We still can cancel loopback edge of not rolling loop;
775 this is always a good idea. */
776 else if (ul
== UL_NO_GROWTH
)
778 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
779 fprintf (dump_file
, "Not unrolling loop %d: size would grow.\n",
783 /* Outer loops tend to be less interesting candidates for complete
784 unrolling unless we can do a lot of propagation into the inner loop
785 body. For now we disable outer loop unrolling when the code would
787 else if (loop
->inner
)
789 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
790 fprintf (dump_file
, "Not unrolling loop %d: "
791 "it is not innermost and code would grow.\n",
795 /* If there is call on a hot path through the loop, then
796 there is most probably not much to optimize. */
797 else if (size
.num_non_pure_calls_on_hot_path
)
799 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
800 fprintf (dump_file
, "Not unrolling loop %d: "
801 "contains call and code would grow.\n",
805 /* If there is pure/const call in the function, then we
806 can still optimize the unrolled loop body if it contains
807 some other interesting code than the calls and code
808 storing or cumulating the return value. */
809 else if (size
.num_pure_calls_on_hot_path
810 /* One IV increment, one test, one ivtmp store
811 and one useful stmt. That is about minimal loop
813 && (size
.non_call_stmts_on_hot_path
814 <= 3 + size
.num_pure_calls_on_hot_path
))
816 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
817 fprintf (dump_file
, "Not unrolling loop %d: "
818 "contains just pure calls and code would grow.\n",
822 /* Complette unrolling is major win when control flow is removed and
823 one big basic block is created. If the loop contains control flow
824 the optimization may still be a win because of eliminating the loop
825 overhead but it also may blow the branch predictor tables.
826 Limit number of branches on the hot path through the peeled
828 else if (size
.num_branches_on_hot_path
* (int)n_unroll
829 > PARAM_VALUE (PARAM_MAX_PEEL_BRANCHES
))
831 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
832 fprintf (dump_file
, "Not unrolling loop %d: "
833 " number of branches on hot path in the unrolled sequence"
834 " reach --param max-peel-branches limit.\n",
839 > (unsigned) PARAM_VALUE (PARAM_MAX_COMPLETELY_PEELED_INSNS
))
841 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
842 fprintf (dump_file
, "Not unrolling loop %d: "
843 "(--param max-completely-peeled-insns limit reached).\n",
847 dump_printf_loc (report_flags
, locus
,
848 "loop turned into non-loop; it never loops.\n");
850 initialize_original_copy_tables ();
851 wont_exit
= sbitmap_alloc (n_unroll
+ 1);
852 bitmap_ones (wont_exit
);
853 bitmap_clear_bit (wont_exit
, 0);
855 if (!gimple_duplicate_loop_to_header_edge (loop
, loop_preheader_edge (loop
),
858 DLTHE_FLAG_UPDATE_FREQ
859 | DLTHE_FLAG_COMPLETTE_PEEL
))
861 free_original_copy_tables ();
863 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
864 fprintf (dump_file
, "Failed to duplicate the loop\n");
868 FOR_EACH_VEC_ELT (to_remove
, i
, e
)
870 bool ok
= remove_path (e
);
874 to_remove
.release ();
876 free_original_copy_tables ();
880 /* Remove the conditional from the last copy of the loop. */
883 cond
= last_stmt (edge_to_cancel
->src
);
884 if (edge_to_cancel
->flags
& EDGE_TRUE_VALUE
)
885 gimple_cond_make_false (cond
);
887 gimple_cond_make_true (cond
);
889 /* Do not remove the path. Doing so may remove outer loop
890 and confuse bookkeeping code in tree_unroll_loops_completelly. */
893 /* Store the loop for later unlooping and exit removal. */
894 loops_to_unloop
.safe_push (loop
);
895 loops_to_unloop_nunroll
.safe_push (n_unroll
);
897 if (dump_enabled_p ())
900 dump_printf_loc (MSG_OPTIMIZED_LOCATIONS
| TDF_DETAILS
, locus
,
901 "loop turned into non-loop; it never loops\n");
904 dump_printf_loc (MSG_OPTIMIZED_LOCATIONS
| TDF_DETAILS
, locus
,
905 "loop with %d iterations completely unrolled",
906 (int) (n_unroll
+ 1));
908 dump_printf (MSG_OPTIMIZED_LOCATIONS
| TDF_DETAILS
,
909 " (header execution count %d)",
910 (int)loop
->header
->count
);
911 dump_printf (MSG_OPTIMIZED_LOCATIONS
| TDF_DETAILS
, "\n");
915 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
918 fprintf (dump_file
, "Exit condition of peeled iterations was "
921 fprintf (dump_file
, "Last iteration exit edge was proved true.\n");
923 fprintf (dump_file
, "Latch of last iteration was marked by "
924 "__builtin_unreachable ().\n");
930 /* Return number of instructions after peeling. */
931 static unsigned HOST_WIDE_INT
932 estimated_peeled_sequence_size (struct loop_size
*size
,
933 unsigned HOST_WIDE_INT npeel
)
935 return MAX (npeel
* (HOST_WIDE_INT
) (size
->overall
936 - size
->eliminated_by_peeling
), 1);
939 /* If the loop is expected to iterate N times and is
940 small enough, duplicate the loop body N+1 times before
941 the loop itself. This way the hot path will never
943 Parameters are the same as for try_unroll_loops_completely */
946 try_peel_loop (struct loop
*loop
,
947 edge exit
, tree niter
,
948 HOST_WIDE_INT maxiter
)
951 struct loop_size size
;
955 vec
<edge
> to_remove
= vNULL
;
958 /* If the iteration bound is known and large, then we can safely eliminate
959 the check in peeled copies. */
960 if (TREE_CODE (niter
) != INTEGER_CST
)
963 if (!flag_peel_loops
|| PARAM_VALUE (PARAM_MAX_PEEL_TIMES
) <= 0)
966 /* Peel only innermost loops. */
970 fprintf (dump_file
, "Not peeling: outer loop\n");
974 if (!optimize_loop_for_speed_p (loop
))
977 fprintf (dump_file
, "Not peeling: cold loop\n");
981 /* Check if there is an estimate on the number of iterations. */
982 npeel
= estimated_loop_iterations_int (loop
);
986 fprintf (dump_file
, "Not peeling: number of iterations is not "
990 if (maxiter
>= 0 && maxiter
<= npeel
)
993 fprintf (dump_file
, "Not peeling: upper bound is known so can "
994 "unroll completely\n");
998 /* We want to peel estimated number of iterations + 1 (so we never
999 enter the loop on quick path). Check against PARAM_MAX_PEEL_TIMES
1000 and be sure to avoid overflows. */
1001 if (npeel
> PARAM_VALUE (PARAM_MAX_PEEL_TIMES
) - 1)
1004 fprintf (dump_file
, "Not peeling: rolls too much "
1005 "(%i + 1 > --param max-peel-times)\n", npeel
);
1010 /* Check peeled loops size. */
1011 tree_estimate_loop_size (loop
, exit
, NULL
, &size
,
1012 PARAM_VALUE (PARAM_MAX_PEELED_INSNS
));
1013 if ((peeled_size
= estimated_peeled_sequence_size (&size
, npeel
))
1014 > PARAM_VALUE (PARAM_MAX_PEELED_INSNS
))
1017 fprintf (dump_file
, "Not peeling: peeled sequence size is too large "
1018 "(%i insns > --param max-peel-insns)", peeled_size
);
1022 /* Duplicate possibly eliminating the exits. */
1023 initialize_original_copy_tables ();
1024 wont_exit
= sbitmap_alloc (npeel
+ 1);
1025 bitmap_ones (wont_exit
);
1026 bitmap_clear_bit (wont_exit
, 0);
1027 if (!gimple_duplicate_loop_to_header_edge (loop
, loop_preheader_edge (loop
),
1030 DLTHE_FLAG_UPDATE_FREQ
1031 | DLTHE_FLAG_COMPLETTE_PEEL
))
1033 free_original_copy_tables ();
1037 FOR_EACH_VEC_ELT (to_remove
, i
, e
)
1039 bool ok
= remove_path (e
);
1043 free_original_copy_tables ();
1044 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
1046 fprintf (dump_file
, "Peeled loop %d, %i times.\n",
1049 if (loop
->any_upper_bound
)
1050 loop
->nb_iterations_upper_bound
-= npeel
;
1051 loop
->nb_iterations_estimate
= 0;
1052 /* Make sure to mark loop cold so we do not try to peel it more. */
1053 scale_loop_profile (loop
, 1, 0);
1054 loop
->header
->count
= 0;
1057 /* Adds a canonical induction variable to LOOP if suitable.
1058 CREATE_IV is true if we may create a new iv. UL determines
1059 which loops we are allowed to completely unroll. If TRY_EVAL is true, we try
1060 to determine the number of iterations of a loop by direct evaluation.
1061 Returns true if cfg is changed. */
1064 canonicalize_loop_induction_variables (struct loop
*loop
,
1065 bool create_iv
, enum unroll_level ul
,
1070 HOST_WIDE_INT maxiter
;
1071 bool modified
= false;
1072 location_t locus
= UNKNOWN_LOCATION
;
1074 niter
= number_of_latch_executions (loop
);
1075 exit
= single_exit (loop
);
1076 if (TREE_CODE (niter
) == INTEGER_CST
)
1077 locus
= gimple_location (last_stmt (exit
->src
));
1080 /* If the loop has more than one exit, try checking all of them
1081 for # of iterations determinable through scev. */
1083 niter
= find_loop_niter (loop
, &exit
);
1085 /* Finally if everything else fails, try brute force evaluation. */
1087 && (chrec_contains_undetermined (niter
)
1088 || TREE_CODE (niter
) != INTEGER_CST
))
1089 niter
= find_loop_niter_by_eval (loop
, &exit
);
1092 locus
= gimple_location (last_stmt (exit
->src
));
1094 if (TREE_CODE (niter
) != INTEGER_CST
)
1098 /* We work exceptionally hard here to estimate the bound
1099 by find_loop_niter_by_eval. Be sure to keep it for future. */
1100 if (niter
&& TREE_CODE (niter
) == INTEGER_CST
)
1102 record_niter_bound (loop
, wi::to_widest (niter
),
1103 exit
== single_likely_exit (loop
), true);
1106 /* Force re-computation of loop bounds so we can remove redundant exits. */
1107 maxiter
= max_loop_iterations_int (loop
);
1109 if (dump_file
&& (dump_flags
& TDF_DETAILS
)
1110 && TREE_CODE (niter
) == INTEGER_CST
)
1112 fprintf (dump_file
, "Loop %d iterates ", loop
->num
);
1113 print_generic_expr (dump_file
, niter
, TDF_SLIM
);
1114 fprintf (dump_file
, " times.\n");
1116 if (dump_file
&& (dump_flags
& TDF_DETAILS
)
1119 fprintf (dump_file
, "Loop %d iterates at most %i times.\n", loop
->num
,
1123 /* Remove exits that are known to be never taken based on loop bound.
1124 Needs to be called after compilation of max_loop_iterations_int that
1125 populates the loop bounds. */
1126 modified
|= remove_redundant_iv_tests (loop
);
1128 if (try_unroll_loop_completely (loop
, exit
, niter
, ul
, maxiter
, locus
))
1132 && niter
&& !chrec_contains_undetermined (niter
)
1133 && exit
&& just_once_each_iteration_p (loop
, exit
->src
))
1134 create_canonical_iv (loop
, exit
, niter
);
1137 modified
|= try_peel_loop (loop
, exit
, niter
, maxiter
);
1142 /* The main entry point of the pass. Adds canonical induction variables
1143 to the suitable loops. */
1146 canonicalize_induction_variables (void)
1149 bool changed
= false;
1150 bool irred_invalidated
= false;
1151 bitmap loop_closed_ssa_invalidated
= BITMAP_ALLOC (NULL
);
1153 free_numbers_of_iterations_estimates ();
1154 estimate_numbers_of_iterations ();
1156 FOR_EACH_LOOP (loop
, LI_FROM_INNERMOST
)
1158 changed
|= canonicalize_loop_induction_variables (loop
,
1159 true, UL_SINGLE_ITER
,
1162 gcc_assert (!need_ssa_update_p (cfun
));
1164 unloop_loops (loop_closed_ssa_invalidated
, &irred_invalidated
);
1165 if (irred_invalidated
1166 && loops_state_satisfies_p (LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS
))
1167 mark_irreducible_loops ();
1169 /* Clean up the information about numbers of iterations, since brute force
1170 evaluation could reveal new information. */
1173 if (!bitmap_empty_p (loop_closed_ssa_invalidated
))
1175 gcc_checking_assert (loops_state_satisfies_p (LOOP_CLOSED_SSA
));
1176 rewrite_into_loop_closed_ssa (NULL
, TODO_update_ssa
);
1178 BITMAP_FREE (loop_closed_ssa_invalidated
);
1181 return TODO_cleanup_cfg
;
1185 /* Propagate VAL into all uses of SSA_NAME. */
1188 propagate_into_all_uses (tree ssa_name
, tree val
)
1190 imm_use_iterator iter
;
1193 FOR_EACH_IMM_USE_STMT (use_stmt
, iter
, ssa_name
)
1195 gimple_stmt_iterator use_stmt_gsi
= gsi_for_stmt (use_stmt
);
1198 FOR_EACH_IMM_USE_ON_STMT (use
, iter
)
1201 if (is_gimple_assign (use_stmt
)
1202 && get_gimple_rhs_class (gimple_assign_rhs_code (use_stmt
))
1203 == GIMPLE_SINGLE_RHS
)
1205 tree rhs
= gimple_assign_rhs1 (use_stmt
);
1207 if (TREE_CODE (rhs
) == ADDR_EXPR
)
1208 recompute_tree_invariant_for_addr_expr (rhs
);
1211 fold_stmt_inplace (&use_stmt_gsi
);
1212 update_stmt (use_stmt
);
1213 maybe_clean_or_replace_eh_stmt (use_stmt
, use_stmt
);
1217 /* Propagate constant SSA_NAMEs defined in basic block BB. */
1220 propagate_constants_for_unrolling (basic_block bb
)
1222 gimple_stmt_iterator gsi
;
1224 /* Look for degenerate PHI nodes with constant argument. */
1225 for (gsi
= gsi_start_phis (bb
); !gsi_end_p (gsi
); )
1227 gimple phi
= gsi_stmt (gsi
);
1228 tree result
= gimple_phi_result (phi
);
1229 tree arg
= gimple_phi_arg_def (phi
, 0);
1231 if (gimple_phi_num_args (phi
) == 1 && TREE_CODE (arg
) == INTEGER_CST
)
1233 propagate_into_all_uses (result
, arg
);
1234 gsi_remove (&gsi
, true);
1235 release_ssa_name (result
);
1241 /* Look for assignments to SSA names with constant RHS. */
1242 for (gsi
= gsi_start_bb (bb
); !gsi_end_p (gsi
); )
1244 gimple stmt
= gsi_stmt (gsi
);
1247 if (is_gimple_assign (stmt
)
1248 && gimple_assign_rhs_code (stmt
) == INTEGER_CST
1249 && (lhs
= gimple_assign_lhs (stmt
), TREE_CODE (lhs
) == SSA_NAME
)
1250 && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs
))
1252 propagate_into_all_uses (lhs
, gimple_assign_rhs1 (stmt
));
1253 gsi_remove (&gsi
, true);
1254 release_ssa_name (lhs
);
1261 /* Process loops from innermost to outer, stopping at the innermost
1262 loop we unrolled. */
1265 tree_unroll_loops_completely_1 (bool may_increase_size
, bool unroll_outer
,
1266 vec
<loop_p
, va_heap
>& father_stack
,
1269 struct loop
*loop_father
;
1270 bool changed
= false;
1272 enum unroll_level ul
;
1274 /* Process inner loops first. */
1275 for (inner
= loop
->inner
; inner
!= NULL
; inner
= inner
->next
)
1276 changed
|= tree_unroll_loops_completely_1 (may_increase_size
,
1277 unroll_outer
, father_stack
,
1280 /* If we changed an inner loop we cannot process outer loops in this
1281 iteration because SSA form is not up-to-date. Continue with
1282 siblings of outer loops instead. */
1286 /* Don't unroll #pragma omp simd loops until the vectorizer
1287 attempts to vectorize those. */
1288 if (loop
->force_vectorize
)
1291 /* Try to unroll this loop. */
1292 loop_father
= loop_outer (loop
);
1296 if (may_increase_size
&& optimize_loop_nest_for_speed_p (loop
)
1297 /* Unroll outermost loops only if asked to do so or they do
1298 not cause code growth. */
1299 && (unroll_outer
|| loop_outer (loop_father
)))
1304 if (canonicalize_loop_induction_variables
1305 (loop
, false, ul
, !flag_tree_loop_ivcanon
))
1307 /* If we'll continue unrolling, we need to propagate constants
1308 within the new basic blocks to fold away induction variable
1309 computations; otherwise, the size might blow up before the
1310 iteration is complete and the IR eventually cleaned up. */
1311 if (loop_outer (loop_father
) && !loop_father
->aux
)
1313 father_stack
.safe_push (loop_father
);
1314 loop_father
->aux
= loop_father
;
1323 /* Unroll LOOPS completely if they iterate just few times. Unless
1324 MAY_INCREASE_SIZE is true, perform the unrolling only if the
1325 size of the code does not increase. */
1328 tree_unroll_loops_completely (bool may_increase_size
, bool unroll_outer
)
1330 auto_vec
<loop_p
, 16> father_stack
;
1333 bool irred_invalidated
= false;
1338 bitmap loop_closed_ssa_invalidated
= NULL
;
1340 if (loops_state_satisfies_p (LOOP_CLOSED_SSA
))
1341 loop_closed_ssa_invalidated
= BITMAP_ALLOC (NULL
);
1343 free_numbers_of_iterations_estimates ();
1344 estimate_numbers_of_iterations ();
1346 changed
= tree_unroll_loops_completely_1 (may_increase_size
,
1347 unroll_outer
, father_stack
,
1348 current_loops
->tree_root
);
1354 /* Be sure to skip unlooped loops while procesing father_stack
1356 FOR_EACH_VEC_ELT (loops_to_unloop
, i
, iter
)
1357 (*iter
)->aux
= NULL
;
1358 FOR_EACH_VEC_ELT (father_stack
, i
, iter
)
1361 unloop_loops (loop_closed_ssa_invalidated
, &irred_invalidated
);
1363 /* We can not use TODO_update_ssa_no_phi because VOPS gets confused. */
1364 if (loop_closed_ssa_invalidated
1365 && !bitmap_empty_p (loop_closed_ssa_invalidated
))
1366 rewrite_into_loop_closed_ssa (loop_closed_ssa_invalidated
,
1369 update_ssa (TODO_update_ssa
);
1371 /* Propagate the constants within the new basic blocks. */
1372 FOR_EACH_VEC_ELT (father_stack
, i
, iter
)
1376 basic_block
*body
= get_loop_body_in_dom_order (*iter
);
1377 for (j
= 0; j
< (*iter
)->num_nodes
; j
++)
1378 propagate_constants_for_unrolling (body
[j
]);
1380 (*iter
)->aux
= NULL
;
1382 father_stack
.truncate (0);
1384 /* This will take care of removing completely unrolled loops
1385 from the loop structures so we can continue unrolling now
1387 if (cleanup_tree_cfg ())
1388 update_ssa (TODO_update_ssa_only_virtuals
);
1390 /* Clean up the information about numbers of iterations, since
1391 complete unrolling might have invalidated it. */
1393 #ifdef ENABLE_CHECKING
1394 if (loops_state_satisfies_p (LOOP_CLOSED_SSA
))
1395 verify_loop_closed_ssa (true);
1398 if (loop_closed_ssa_invalidated
)
1399 BITMAP_FREE (loop_closed_ssa_invalidated
);
1402 && ++iteration
<= PARAM_VALUE (PARAM_MAX_UNROLL_ITERATIONS
));
1404 father_stack
.release ();
1406 if (irred_invalidated
1407 && loops_state_satisfies_p (LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS
))
1408 mark_irreducible_loops ();
1413 /* Canonical induction variable creation pass. */
1417 const pass_data pass_data_iv_canon
=
1419 GIMPLE_PASS
, /* type */
1420 "ivcanon", /* name */
1421 OPTGROUP_LOOP
, /* optinfo_flags */
1422 TV_TREE_LOOP_IVCANON
, /* tv_id */
1423 ( PROP_cfg
| PROP_ssa
), /* properties_required */
1424 0, /* properties_provided */
1425 0, /* properties_destroyed */
1426 0, /* todo_flags_start */
1427 0, /* todo_flags_finish */
1430 class pass_iv_canon
: public gimple_opt_pass
1433 pass_iv_canon (gcc::context
*ctxt
)
1434 : gimple_opt_pass (pass_data_iv_canon
, ctxt
)
1437 /* opt_pass methods: */
1438 virtual bool gate (function
*) { return flag_tree_loop_ivcanon
!= 0; }
1439 virtual unsigned int execute (function
*fun
);
1441 }; // class pass_iv_canon
1444 pass_iv_canon::execute (function
*fun
)
1446 if (number_of_loops (fun
) <= 1)
1449 return canonicalize_induction_variables ();
1455 make_pass_iv_canon (gcc::context
*ctxt
)
1457 return new pass_iv_canon (ctxt
);
1460 /* Complete unrolling of loops. */
1464 const pass_data pass_data_complete_unroll
=
1466 GIMPLE_PASS
, /* type */
1467 "cunroll", /* name */
1468 OPTGROUP_LOOP
, /* optinfo_flags */
1469 TV_COMPLETE_UNROLL
, /* tv_id */
1470 ( PROP_cfg
| PROP_ssa
), /* properties_required */
1471 0, /* properties_provided */
1472 0, /* properties_destroyed */
1473 0, /* todo_flags_start */
1474 0, /* todo_flags_finish */
1477 class pass_complete_unroll
: public gimple_opt_pass
1480 pass_complete_unroll (gcc::context
*ctxt
)
1481 : gimple_opt_pass (pass_data_complete_unroll
, ctxt
)
1484 /* opt_pass methods: */
1485 virtual unsigned int execute (function
*);
1487 }; // class pass_complete_unroll
1490 pass_complete_unroll::execute (function
*fun
)
1492 if (number_of_loops (fun
) <= 1)
1495 return tree_unroll_loops_completely (flag_unroll_loops
1497 || optimize
>= 3, true);
1503 make_pass_complete_unroll (gcc::context
*ctxt
)
1505 return new pass_complete_unroll (ctxt
);
1508 /* Complete unrolling of inner loops. */
1512 const pass_data pass_data_complete_unrolli
=
1514 GIMPLE_PASS
, /* type */
1515 "cunrolli", /* name */
1516 OPTGROUP_LOOP
, /* optinfo_flags */
1517 TV_COMPLETE_UNROLL
, /* tv_id */
1518 ( PROP_cfg
| PROP_ssa
), /* properties_required */
1519 0, /* properties_provided */
1520 0, /* properties_destroyed */
1521 0, /* todo_flags_start */
1522 0, /* todo_flags_finish */
1525 class pass_complete_unrolli
: public gimple_opt_pass
1528 pass_complete_unrolli (gcc::context
*ctxt
)
1529 : gimple_opt_pass (pass_data_complete_unrolli
, ctxt
)
1532 /* opt_pass methods: */
1533 virtual bool gate (function
*) { return optimize
>= 2; }
1534 virtual unsigned int execute (function
*);
1536 }; // class pass_complete_unrolli
1539 pass_complete_unrolli::execute (function
*fun
)
1543 loop_optimizer_init (LOOPS_NORMAL
1544 | LOOPS_HAVE_RECORDED_EXITS
);
1545 if (number_of_loops (fun
) > 1)
1548 ret
= tree_unroll_loops_completely (optimize
>= 3, false);
1549 free_numbers_of_iterations_estimates ();
1552 loop_optimizer_finalize ();
1560 make_pass_complete_unrolli (gcc::context
*ctxt
)
1562 return new pass_complete_unrolli (ctxt
);