1 /* Induction variable canonicalization and loop peeling.
2 Copyright (C) 2004-2016 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"
45 #include "tree-pass.h"
48 #include "gimple-pretty-print.h"
49 #include "fold-const.h"
51 #include "gimple-fold.h"
53 #include "gimple-iterator.h"
55 #include "tree-ssa-loop-manip.h"
56 #include "tree-ssa-loop-niter.h"
57 #include "tree-ssa-loop.h"
58 #include "tree-into-ssa.h"
60 #include "tree-chrec.h"
61 #include "tree-scalar-evolution.h"
63 #include "tree-inline.h"
64 #include "tree-cfgcleanup.h"
67 /* Specifies types of loops that may be unrolled. */
71 UL_SINGLE_ITER
, /* Only loops that exit immediately in the first
73 UL_NO_GROWTH
, /* Only loops whose unrolling will not cause increase
75 UL_ALL
/* All suitable loops. */
78 /* Adds a canonical induction variable to LOOP iterating NITER times. EXIT
79 is the exit edge whose condition is replaced. */
82 create_canonical_iv (struct loop
*loop
, edge exit
, tree niter
)
87 gimple_stmt_iterator incr_at
;
90 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
92 fprintf (dump_file
, "Added canonical iv to loop %d, ", loop
->num
);
93 print_generic_expr (dump_file
, niter
, TDF_SLIM
);
94 fprintf (dump_file
, " iterations.\n");
97 cond
= as_a
<gcond
*> (last_stmt (exit
->src
));
98 in
= EDGE_SUCC (exit
->src
, 0);
100 in
= EDGE_SUCC (exit
->src
, 1);
102 /* Note that we do not need to worry about overflows, since
103 type of niter is always unsigned and all comparisons are
104 just for equality/nonequality -- i.e. everything works
105 with a modulo arithmetics. */
107 type
= TREE_TYPE (niter
);
108 niter
= fold_build2 (PLUS_EXPR
, type
,
110 build_int_cst (type
, 1));
111 incr_at
= gsi_last_bb (in
->src
);
113 build_int_cst (type
, -1),
115 &incr_at
, false, NULL
, &var
);
117 cmp
= (exit
->flags
& EDGE_TRUE_VALUE
) ? EQ_EXPR
: NE_EXPR
;
118 gimple_cond_set_code (cond
, cmp
);
119 gimple_cond_set_lhs (cond
, var
);
120 gimple_cond_set_rhs (cond
, build_int_cst (type
, 0));
124 /* Describe size of loop as detected by tree_estimate_loop_size. */
127 /* Number of instructions in the loop. */
130 /* Number of instructions that will be likely optimized out in
131 peeled iterations of loop (i.e. computation based on induction
132 variable where induction variable starts at known constant.) */
133 int eliminated_by_peeling
;
135 /* Same statistics for last iteration of loop: it is smaller because
136 instructions after exit are not executed. */
138 int last_iteration_eliminated_by_peeling
;
140 /* If some IV computation will become constant. */
143 /* Number of call stmts that are not a builtin and are pure or const
144 present on the hot path. */
145 int num_pure_calls_on_hot_path
;
146 /* Number of call stmts that are not a builtin and are not pure nor const
147 present on the hot path. */
148 int num_non_pure_calls_on_hot_path
;
149 /* Number of statements other than calls in the loop. */
150 int non_call_stmts_on_hot_path
;
151 /* Number of branches seen on the hot path. */
152 int num_branches_on_hot_path
;
155 /* Return true if OP in STMT will be constant after peeling LOOP. */
158 constant_after_peeling (tree op
, gimple
*stmt
, struct loop
*loop
)
162 if (is_gimple_min_invariant (op
))
165 /* We can still fold accesses to constant arrays when index is known. */
166 if (TREE_CODE (op
) != SSA_NAME
)
170 /* First make fast look if we see constant array inside. */
171 while (handled_component_p (base
))
172 base
= TREE_OPERAND (base
, 0);
174 && ctor_for_folding (base
) != error_mark_node
)
175 || CONSTANT_CLASS_P (base
))
177 /* If so, see if we understand all the indices. */
179 while (handled_component_p (base
))
181 if (TREE_CODE (base
) == ARRAY_REF
182 && !constant_after_peeling (TREE_OPERAND (base
, 1), stmt
, loop
))
184 base
= TREE_OPERAND (base
, 0);
191 /* Induction variables are constants. */
192 if (!simple_iv (loop
, loop_containing_stmt (stmt
), op
, &iv
, false))
194 if (!is_gimple_min_invariant (iv
.base
))
196 if (!is_gimple_min_invariant (iv
.step
))
201 /* Computes an estimated number of insns in LOOP.
202 EXIT (if non-NULL) is an exite edge that will be eliminated in all but last
203 iteration of the loop.
204 EDGE_TO_CANCEL (if non-NULL) is an non-exit edge eliminated in the last iteration
206 Return results in SIZE, estimate benefits for complete unrolling exiting by EXIT.
207 Stop estimating after UPPER_BOUND is met. Return true in this case. */
210 tree_estimate_loop_size (struct loop
*loop
, edge exit
, edge edge_to_cancel
, struct loop_size
*size
,
213 basic_block
*body
= get_loop_body (loop
);
214 gimple_stmt_iterator gsi
;
217 vec
<basic_block
> path
= get_loop_hot_path (loop
);
220 size
->eliminated_by_peeling
= 0;
221 size
->last_iteration
= 0;
222 size
->last_iteration_eliminated_by_peeling
= 0;
223 size
->num_pure_calls_on_hot_path
= 0;
224 size
->num_non_pure_calls_on_hot_path
= 0;
225 size
->non_call_stmts_on_hot_path
= 0;
226 size
->num_branches_on_hot_path
= 0;
227 size
->constant_iv
= 0;
229 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
230 fprintf (dump_file
, "Estimating sizes for loop %i\n", loop
->num
);
231 for (i
= 0; i
< loop
->num_nodes
; i
++)
233 if (edge_to_cancel
&& body
[i
] != edge_to_cancel
->src
234 && dominated_by_p (CDI_DOMINATORS
, body
[i
], edge_to_cancel
->src
))
238 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
239 fprintf (dump_file
, " BB: %i, after_exit: %i\n", body
[i
]->index
, after_exit
);
241 for (gsi
= gsi_start_bb (body
[i
]); !gsi_end_p (gsi
); gsi_next (&gsi
))
243 gimple
*stmt
= gsi_stmt (gsi
);
244 int num
= estimate_num_insns (stmt
, &eni_size_weights
);
245 bool likely_eliminated
= false;
246 bool likely_eliminated_last
= false;
247 bool likely_eliminated_peeled
= false;
249 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
251 fprintf (dump_file
, " size: %3i ", num
);
252 print_gimple_stmt (dump_file
, gsi_stmt (gsi
), 0, 0);
255 /* Look for reasons why we might optimize this stmt away. */
257 if (gimple_has_side_effects (stmt
))
259 /* Exit conditional. */
260 else if (exit
&& body
[i
] == exit
->src
261 && stmt
== last_stmt (exit
->src
))
263 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
264 fprintf (dump_file
, " Exit condition will be eliminated "
265 "in peeled copies.\n");
266 likely_eliminated_peeled
= true;
268 else if (edge_to_cancel
&& body
[i
] == edge_to_cancel
->src
269 && stmt
== last_stmt (edge_to_cancel
->src
))
271 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
272 fprintf (dump_file
, " Exit condition will be eliminated "
274 likely_eliminated_last
= true;
276 /* Sets of IV variables */
277 else if (gimple_code (stmt
) == GIMPLE_ASSIGN
278 && constant_after_peeling (gimple_assign_lhs (stmt
), stmt
, loop
))
280 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
281 fprintf (dump_file
, " Induction variable computation will"
282 " be folded away.\n");
283 likely_eliminated
= true;
285 /* Assignments of IV variables. */
286 else if (gimple_code (stmt
) == GIMPLE_ASSIGN
287 && TREE_CODE (gimple_assign_lhs (stmt
)) == SSA_NAME
288 && constant_after_peeling (gimple_assign_rhs1 (stmt
), stmt
, loop
)
289 && (gimple_assign_rhs_class (stmt
) != GIMPLE_BINARY_RHS
290 || constant_after_peeling (gimple_assign_rhs2 (stmt
),
293 size
->constant_iv
= true;
294 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
295 fprintf (dump_file
, " Constant expression will be folded away.\n");
296 likely_eliminated
= true;
299 else if ((gimple_code (stmt
) == GIMPLE_COND
300 && constant_after_peeling (gimple_cond_lhs (stmt
), stmt
, loop
)
301 && constant_after_peeling (gimple_cond_rhs (stmt
), stmt
, loop
)
302 /* We don't simplify all constant compares so make sure
303 they are not both constant already. See PR70288. */
304 && (! is_gimple_min_invariant (gimple_cond_lhs (stmt
))
305 || ! is_gimple_min_invariant (gimple_cond_rhs (stmt
))))
306 || (gimple_code (stmt
) == GIMPLE_SWITCH
307 && constant_after_peeling (gimple_switch_index (
308 as_a
<gswitch
*> (stmt
)),
310 && ! is_gimple_min_invariant (gimple_switch_index (
311 as_a
<gswitch
*> (stmt
)))))
313 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
314 fprintf (dump_file
, " Constant conditional.\n");
315 likely_eliminated
= true;
318 size
->overall
+= num
;
319 if (likely_eliminated
|| likely_eliminated_peeled
)
320 size
->eliminated_by_peeling
+= num
;
323 size
->last_iteration
+= num
;
324 if (likely_eliminated
|| likely_eliminated_last
)
325 size
->last_iteration_eliminated_by_peeling
+= num
;
327 if ((size
->overall
* 3 / 2 - size
->eliminated_by_peeling
328 - size
->last_iteration_eliminated_by_peeling
) > upper_bound
)
336 while (path
.length ())
338 basic_block bb
= path
.pop ();
339 for (gsi
= gsi_start_bb (bb
); !gsi_end_p (gsi
); gsi_next (&gsi
))
341 gimple
*stmt
= gsi_stmt (gsi
);
342 if (gimple_code (stmt
) == GIMPLE_CALL
)
344 int flags
= gimple_call_flags (stmt
);
345 tree decl
= gimple_call_fndecl (stmt
);
347 if (decl
&& DECL_IS_BUILTIN (decl
)
348 && is_inexpensive_builtin (decl
))
350 else if (flags
& (ECF_PURE
| ECF_CONST
))
351 size
->num_pure_calls_on_hot_path
++;
353 size
->num_non_pure_calls_on_hot_path
++;
354 size
->num_branches_on_hot_path
++;
356 else if (gimple_code (stmt
) != GIMPLE_CALL
357 && gimple_code (stmt
) != GIMPLE_DEBUG
)
358 size
->non_call_stmts_on_hot_path
++;
359 if (((gimple_code (stmt
) == GIMPLE_COND
360 && (!constant_after_peeling (gimple_cond_lhs (stmt
), stmt
, loop
)
361 || constant_after_peeling (gimple_cond_rhs (stmt
), stmt
, loop
)))
362 || (gimple_code (stmt
) == GIMPLE_SWITCH
363 && !constant_after_peeling (gimple_switch_index (
364 as_a
<gswitch
*> (stmt
)),
366 && (!exit
|| bb
!= exit
->src
))
367 size
->num_branches_on_hot_path
++;
371 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
372 fprintf (dump_file
, "size: %i-%i, last_iteration: %i-%i\n", size
->overall
,
373 size
->eliminated_by_peeling
, size
->last_iteration
,
374 size
->last_iteration_eliminated_by_peeling
);
380 /* Estimate number of insns of completely unrolled loop.
381 It is (NUNROLL + 1) * size of loop body with taking into account
382 the fact that in last copy everything after exit conditional
383 is dead and that some instructions will be eliminated after
386 Loop body is likely going to simplify further, this is difficult
387 to guess, we just decrease the result by 1/3. */
389 static unsigned HOST_WIDE_INT
390 estimated_unrolled_size (struct loop_size
*size
,
391 unsigned HOST_WIDE_INT nunroll
)
393 HOST_WIDE_INT unr_insns
= ((nunroll
)
394 * (HOST_WIDE_INT
) (size
->overall
395 - size
->eliminated_by_peeling
));
398 unr_insns
+= size
->last_iteration
- size
->last_iteration_eliminated_by_peeling
;
400 unr_insns
= unr_insns
* 2 / 3;
407 /* Loop LOOP is known to not loop. See if there is an edge in the loop
408 body that can be remove to make the loop to always exit and at
409 the same time it does not make any code potentially executed
410 during the last iteration dead.
412 After complete unrolling we still may get rid of the conditional
413 on the exit in the last copy even if we have no idea what it does.
414 This is quite common case for loops of form
420 Here we prove the loop to iterate 5 times but we do not know
421 it from induction variable.
423 For now we handle only simple case where there is exit condition
424 just before the latch block and the latch block contains no statements
425 with side effect that may otherwise terminate the execution of loop
426 (such as by EH or by terminating the program or longjmp).
428 In the general case we may want to cancel the paths leading to statements
429 loop-niter identified as having undefined effect in the last iteration.
430 The other cases are hopefully rare and will be cleaned up later. */
433 loop_edge_to_cancel (struct loop
*loop
)
438 gimple_stmt_iterator gsi
;
440 /* We want only one predecestor of the loop. */
441 if (EDGE_COUNT (loop
->latch
->preds
) > 1)
444 exits
= get_loop_exit_edges (loop
);
446 FOR_EACH_VEC_ELT (exits
, i
, edge_to_cancel
)
448 /* Find the other edge than the loop exit
449 leaving the conditoinal. */
450 if (EDGE_COUNT (edge_to_cancel
->src
->succs
) != 2)
452 if (EDGE_SUCC (edge_to_cancel
->src
, 0) == edge_to_cancel
)
453 edge_to_cancel
= EDGE_SUCC (edge_to_cancel
->src
, 1);
455 edge_to_cancel
= EDGE_SUCC (edge_to_cancel
->src
, 0);
457 /* We only can handle conditionals. */
458 if (!(edge_to_cancel
->flags
& (EDGE_TRUE_VALUE
| EDGE_FALSE_VALUE
)))
461 /* We should never have conditionals in the loop latch. */
462 gcc_assert (edge_to_cancel
->dest
!= loop
->header
);
464 /* Check that it leads to loop latch. */
465 if (edge_to_cancel
->dest
!= loop
->latch
)
470 /* Verify that the code in loop latch does nothing that may end program
471 execution without really reaching the exit. This may include
472 non-pure/const function calls, EH statements, volatile ASMs etc. */
473 for (gsi
= gsi_start_bb (loop
->latch
); !gsi_end_p (gsi
); gsi_next (&gsi
))
474 if (gimple_has_side_effects (gsi_stmt (gsi
)))
476 return edge_to_cancel
;
482 /* Remove all tests for exits that are known to be taken after LOOP was
483 peeled NPEELED times. Put gcc_unreachable before every statement
484 known to not be executed. */
487 remove_exits_and_undefined_stmts (struct loop
*loop
, unsigned int npeeled
)
489 struct nb_iter_bound
*elt
;
490 bool changed
= false;
492 for (elt
= loop
->bounds
; elt
; elt
= elt
->next
)
494 /* If statement is known to be undefined after peeling, turn it
495 into unreachable (or trap when debugging experience is supposed
498 && wi::ltu_p (elt
->bound
, npeeled
))
500 gimple_stmt_iterator gsi
= gsi_for_stmt (elt
->stmt
);
501 gcall
*stmt
= gimple_build_call
502 (builtin_decl_implicit (BUILT_IN_UNREACHABLE
), 0);
503 gimple_set_location (stmt
, gimple_location (elt
->stmt
));
504 gsi_insert_before (&gsi
, stmt
, GSI_NEW_STMT
);
505 split_block (gimple_bb (stmt
), stmt
);
507 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
509 fprintf (dump_file
, "Forced statement unreachable: ");
510 print_gimple_stmt (dump_file
, elt
->stmt
, 0, 0);
513 /* If we know the exit will be taken after peeling, update. */
514 else if (elt
->is_exit
515 && wi::leu_p (elt
->bound
, npeeled
))
517 basic_block bb
= gimple_bb (elt
->stmt
);
518 edge exit_edge
= EDGE_SUCC (bb
, 0);
520 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
522 fprintf (dump_file
, "Forced exit to be taken: ");
523 print_gimple_stmt (dump_file
, elt
->stmt
, 0, 0);
525 if (!loop_exit_edge_p (loop
, exit_edge
))
526 exit_edge
= EDGE_SUCC (bb
, 1);
527 gcc_checking_assert (loop_exit_edge_p (loop
, exit_edge
));
528 gcond
*cond_stmt
= as_a
<gcond
*> (elt
->stmt
);
529 if (exit_edge
->flags
& EDGE_TRUE_VALUE
)
530 gimple_cond_make_true (cond_stmt
);
532 gimple_cond_make_false (cond_stmt
);
533 update_stmt (cond_stmt
);
540 /* Remove all exits that are known to be never taken because of the loop bound
544 remove_redundant_iv_tests (struct loop
*loop
)
546 struct nb_iter_bound
*elt
;
547 bool changed
= false;
549 if (!loop
->any_upper_bound
)
551 for (elt
= loop
->bounds
; elt
; elt
= elt
->next
)
553 /* Exit is pointless if it won't be taken before loop reaches
555 if (elt
->is_exit
&& loop
->any_upper_bound
556 && wi::ltu_p (loop
->nb_iterations_upper_bound
, elt
->bound
))
558 basic_block bb
= gimple_bb (elt
->stmt
);
559 edge exit_edge
= EDGE_SUCC (bb
, 0);
560 struct tree_niter_desc niter
;
562 if (!loop_exit_edge_p (loop
, exit_edge
))
563 exit_edge
= EDGE_SUCC (bb
, 1);
565 /* Only when we know the actual number of iterations, not
566 just a bound, we can remove the exit. */
567 if (!number_of_iterations_exit (loop
, exit_edge
,
568 &niter
, false, false)
569 || !integer_onep (niter
.assumptions
)
570 || !integer_zerop (niter
.may_be_zero
)
572 || TREE_CODE (niter
.niter
) != INTEGER_CST
573 || !wi::ltu_p (loop
->nb_iterations_upper_bound
,
574 wi::to_widest (niter
.niter
)))
577 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
579 fprintf (dump_file
, "Removed pointless exit: ");
580 print_gimple_stmt (dump_file
, elt
->stmt
, 0, 0);
582 gcond
*cond_stmt
= as_a
<gcond
*> (elt
->stmt
);
583 if (exit_edge
->flags
& EDGE_TRUE_VALUE
)
584 gimple_cond_make_false (cond_stmt
);
586 gimple_cond_make_true (cond_stmt
);
587 update_stmt (cond_stmt
);
594 /* Stores loops that will be unlooped after we process whole loop tree. */
595 static vec
<loop_p
> loops_to_unloop
;
596 static vec
<int> loops_to_unloop_nunroll
;
598 /* Cancel all fully unrolled loops by putting __builtin_unreachable
600 We do it after all unrolling since unlooping moves basic blocks
601 across loop boundaries trashing loop closed SSA form as well
602 as SCEV info needed to be intact during unrolling.
604 IRRED_INVALIDATED is used to bookkeep if information about
605 irreducible regions may become invalid as a result
606 of the transformation.
607 LOOP_CLOSED_SSA_INVALIDATED is used to bookkepp the case
608 when we need to go into loop closed SSA form. */
611 unloop_loops (bitmap loop_closed_ssa_invalidated
,
612 bool *irred_invalidated
)
614 while (loops_to_unloop
.length ())
616 struct loop
*loop
= loops_to_unloop
.pop ();
617 int n_unroll
= loops_to_unloop_nunroll
.pop ();
618 basic_block latch
= loop
->latch
;
619 edge latch_edge
= loop_latch_edge (loop
);
620 int flags
= latch_edge
->flags
;
621 location_t locus
= latch_edge
->goto_locus
;
623 gimple_stmt_iterator gsi
;
625 remove_exits_and_undefined_stmts (loop
, n_unroll
);
627 /* Unloop destroys the latch edge. */
628 unloop (loop
, irred_invalidated
, loop_closed_ssa_invalidated
);
630 /* Create new basic block for the latch edge destination and wire
632 stmt
= gimple_build_call (builtin_decl_implicit (BUILT_IN_UNREACHABLE
), 0);
633 latch_edge
= make_edge (latch
, create_basic_block (NULL
, NULL
, latch
), flags
);
634 latch_edge
->probability
= 0;
635 latch_edge
->count
= 0;
636 latch_edge
->flags
|= flags
;
637 latch_edge
->goto_locus
= locus
;
639 latch_edge
->dest
->loop_father
= current_loops
->tree_root
;
640 latch_edge
->dest
->count
= 0;
641 latch_edge
->dest
->frequency
= 0;
642 set_immediate_dominator (CDI_DOMINATORS
, latch_edge
->dest
, latch_edge
->src
);
644 gsi
= gsi_start_bb (latch_edge
->dest
);
645 gsi_insert_after (&gsi
, stmt
, GSI_NEW_STMT
);
647 loops_to_unloop
.release ();
648 loops_to_unloop_nunroll
.release ();
651 /* Tries to unroll LOOP completely, i.e. NITER times.
652 UL determines which loops we are allowed to unroll.
653 EXIT is the exit of the loop that should be eliminated.
654 MAXITER specfy bound on number of iterations, -1 if it is
655 not known or too large for HOST_WIDE_INT. The location
656 LOCUS corresponding to the loop is used when emitting
657 a summary of the unroll to the dump file. */
660 try_unroll_loop_completely (struct loop
*loop
,
661 edge exit
, tree niter
,
662 enum unroll_level ul
,
663 HOST_WIDE_INT maxiter
,
666 unsigned HOST_WIDE_INT n_unroll
= 0, ninsns
, unr_insns
;
667 struct loop_size size
;
668 bool n_unroll_found
= false;
669 edge edge_to_cancel
= NULL
;
670 int report_flags
= MSG_OPTIMIZED_LOCATIONS
| TDF_RTL
| TDF_DETAILS
;
672 /* See if we proved number of iterations to be low constant.
674 EXIT is an edge that will be removed in all but last iteration of
677 EDGE_TO_CACNEL is an edge that will be removed from the last iteration
678 of the unrolled sequence and is expected to make the final loop not
681 If the number of execution of loop is determined by standard induction
682 variable test, then EXIT and EDGE_TO_CANCEL are the two edges leaving
684 if (tree_fits_uhwi_p (niter
))
686 n_unroll
= tree_to_uhwi (niter
);
687 n_unroll_found
= true;
688 edge_to_cancel
= EDGE_SUCC (exit
->src
, 0);
689 if (edge_to_cancel
== exit
)
690 edge_to_cancel
= EDGE_SUCC (exit
->src
, 1);
692 /* We do not know the number of iterations and thus we can not eliminate
697 /* See if we can improve our estimate by using recorded loop bounds. */
699 && (!n_unroll_found
|| (unsigned HOST_WIDE_INT
)maxiter
< n_unroll
))
702 n_unroll_found
= true;
703 /* Loop terminates before the IV variable test, so we can not
704 remove it in the last iteration. */
705 edge_to_cancel
= NULL
;
711 if (n_unroll
> (unsigned) PARAM_VALUE (PARAM_MAX_COMPLETELY_PEEL_TIMES
))
713 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
714 fprintf (dump_file
, "Not unrolling loop %d "
715 "(--param max-completely-peel-times limit reached).\n",
721 edge_to_cancel
= loop_edge_to_cancel (loop
);
729 vec
<edge
> to_remove
= vNULL
;
730 if (ul
== UL_SINGLE_ITER
)
733 large
= tree_estimate_loop_size
734 (loop
, exit
, edge_to_cancel
, &size
,
735 PARAM_VALUE (PARAM_MAX_COMPLETELY_PEELED_INSNS
));
736 ninsns
= size
.overall
;
739 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
740 fprintf (dump_file
, "Not unrolling loop %d: it is too large.\n",
745 unr_insns
= estimated_unrolled_size (&size
, n_unroll
);
746 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
748 fprintf (dump_file
, " Loop size: %d\n", (int) ninsns
);
749 fprintf (dump_file
, " Estimated size after unrolling: %d\n",
753 /* If the code is going to shrink, we don't need to be extra cautious
754 on guessing if the unrolling is going to be profitable. */
756 /* If there is IV variable that will become constant, we save
757 one instruction in the loop prologue we do not account
759 <= ninsns
+ (size
.constant_iv
!= false))
761 /* We unroll only inner loops, because we do not consider it profitable
762 otheriwse. We still can cancel loopback edge of not rolling loop;
763 this is always a good idea. */
764 else if (ul
== UL_NO_GROWTH
)
766 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
767 fprintf (dump_file
, "Not unrolling loop %d: size would grow.\n",
771 /* Outer loops tend to be less interesting candidates for complete
772 unrolling unless we can do a lot of propagation into the inner loop
773 body. For now we disable outer loop unrolling when the code would
775 else if (loop
->inner
)
777 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
778 fprintf (dump_file
, "Not unrolling loop %d: "
779 "it is not innermost and code would grow.\n",
783 /* If there is call on a hot path through the loop, then
784 there is most probably not much to optimize. */
785 else if (size
.num_non_pure_calls_on_hot_path
)
787 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
788 fprintf (dump_file
, "Not unrolling loop %d: "
789 "contains call and code would grow.\n",
793 /* If there is pure/const call in the function, then we
794 can still optimize the unrolled loop body if it contains
795 some other interesting code than the calls and code
796 storing or cumulating the return value. */
797 else if (size
.num_pure_calls_on_hot_path
798 /* One IV increment, one test, one ivtmp store
799 and one useful stmt. That is about minimal loop
801 && (size
.non_call_stmts_on_hot_path
802 <= 3 + size
.num_pure_calls_on_hot_path
))
804 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
805 fprintf (dump_file
, "Not unrolling loop %d: "
806 "contains just pure calls and code would grow.\n",
810 /* Complete unrolling is a major win when control flow is removed and
811 one big basic block is created. If the loop contains control flow
812 the optimization may still be a win because of eliminating the loop
813 overhead but it also may blow the branch predictor tables.
814 Limit number of branches on the hot path through the peeled
816 else if (size
.num_branches_on_hot_path
* (int)n_unroll
817 > PARAM_VALUE (PARAM_MAX_PEEL_BRANCHES
))
819 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
820 fprintf (dump_file
, "Not unrolling loop %d: "
821 " number of branches on hot path in the unrolled sequence"
822 " reach --param max-peel-branches limit.\n",
827 > (unsigned) PARAM_VALUE (PARAM_MAX_COMPLETELY_PEELED_INSNS
))
829 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
830 fprintf (dump_file
, "Not unrolling loop %d: "
831 "(--param max-completely-peeled-insns limit reached).\n",
835 dump_printf_loc (report_flags
, locus
,
836 "loop turned into non-loop; it never loops.\n");
838 initialize_original_copy_tables ();
839 wont_exit
= sbitmap_alloc (n_unroll
+ 1);
840 bitmap_ones (wont_exit
);
841 bitmap_clear_bit (wont_exit
, 0);
843 if (!gimple_duplicate_loop_to_header_edge (loop
, loop_preheader_edge (loop
),
846 DLTHE_FLAG_UPDATE_FREQ
847 | DLTHE_FLAG_COMPLETTE_PEEL
))
849 free_original_copy_tables ();
851 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
852 fprintf (dump_file
, "Failed to duplicate the loop\n");
856 FOR_EACH_VEC_ELT (to_remove
, i
, e
)
858 bool ok
= remove_path (e
);
862 to_remove
.release ();
864 free_original_copy_tables ();
868 /* Remove the conditional from the last copy of the loop. */
871 gcond
*cond
= as_a
<gcond
*> (last_stmt (edge_to_cancel
->src
));
872 if (edge_to_cancel
->flags
& EDGE_TRUE_VALUE
)
873 gimple_cond_make_false (cond
);
875 gimple_cond_make_true (cond
);
877 /* Do not remove the path. Doing so may remove outer loop
878 and confuse bookkeeping code in tree_unroll_loops_completelly. */
881 /* Store the loop for later unlooping and exit removal. */
882 loops_to_unloop
.safe_push (loop
);
883 loops_to_unloop_nunroll
.safe_push (n_unroll
);
885 if (dump_enabled_p ())
888 dump_printf_loc (MSG_OPTIMIZED_LOCATIONS
| TDF_DETAILS
, locus
,
889 "loop turned into non-loop; it never loops\n");
892 dump_printf_loc (MSG_OPTIMIZED_LOCATIONS
| TDF_DETAILS
, locus
,
893 "loop with %d iterations completely unrolled",
894 (int) (n_unroll
+ 1));
896 dump_printf (MSG_OPTIMIZED_LOCATIONS
| TDF_DETAILS
,
897 " (header execution count %d)",
898 (int)loop
->header
->count
);
899 dump_printf (MSG_OPTIMIZED_LOCATIONS
| TDF_DETAILS
, "\n");
903 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
906 fprintf (dump_file
, "Exit condition of peeled iterations was "
909 fprintf (dump_file
, "Last iteration exit edge was proved true.\n");
911 fprintf (dump_file
, "Latch of last iteration was marked by "
912 "__builtin_unreachable ().\n");
918 /* Return number of instructions after peeling. */
919 static unsigned HOST_WIDE_INT
920 estimated_peeled_sequence_size (struct loop_size
*size
,
921 unsigned HOST_WIDE_INT npeel
)
923 return MAX (npeel
* (HOST_WIDE_INT
) (size
->overall
924 - size
->eliminated_by_peeling
), 1);
927 /* If the loop is expected to iterate N times and is
928 small enough, duplicate the loop body N+1 times before
929 the loop itself. This way the hot path will never
931 Parameters are the same as for try_unroll_loops_completely */
934 try_peel_loop (struct loop
*loop
,
935 edge exit
, tree niter
,
936 HOST_WIDE_INT maxiter
)
939 struct loop_size size
;
943 vec
<edge
> to_remove
= vNULL
;
946 /* If the iteration bound is known and large, then we can safely eliminate
947 the check in peeled copies. */
948 if (TREE_CODE (niter
) != INTEGER_CST
)
951 if (!flag_peel_loops
|| PARAM_VALUE (PARAM_MAX_PEEL_TIMES
) <= 0)
954 /* Peel only innermost loops. */
958 fprintf (dump_file
, "Not peeling: outer loop\n");
962 if (!optimize_loop_for_speed_p (loop
))
965 fprintf (dump_file
, "Not peeling: cold loop\n");
969 /* Check if there is an estimate on the number of iterations. */
970 npeel
= estimated_loop_iterations_int (loop
);
974 fprintf (dump_file
, "Not peeling: number of iterations is not "
978 if (maxiter
>= 0 && maxiter
<= npeel
)
981 fprintf (dump_file
, "Not peeling: upper bound is known so can "
982 "unroll completely\n");
986 /* We want to peel estimated number of iterations + 1 (so we never
987 enter the loop on quick path). Check against PARAM_MAX_PEEL_TIMES
988 and be sure to avoid overflows. */
989 if (npeel
> PARAM_VALUE (PARAM_MAX_PEEL_TIMES
) - 1)
992 fprintf (dump_file
, "Not peeling: rolls too much "
993 "(%i + 1 > --param max-peel-times)\n", (int) npeel
);
998 /* Check peeled loops size. */
999 tree_estimate_loop_size (loop
, exit
, NULL
, &size
,
1000 PARAM_VALUE (PARAM_MAX_PEELED_INSNS
));
1001 if ((peeled_size
= estimated_peeled_sequence_size (&size
, (int) npeel
))
1002 > PARAM_VALUE (PARAM_MAX_PEELED_INSNS
))
1005 fprintf (dump_file
, "Not peeling: peeled sequence size is too large "
1006 "(%i insns > --param max-peel-insns)", peeled_size
);
1010 /* Duplicate possibly eliminating the exits. */
1011 initialize_original_copy_tables ();
1012 wont_exit
= sbitmap_alloc (npeel
+ 1);
1013 bitmap_ones (wont_exit
);
1014 bitmap_clear_bit (wont_exit
, 0);
1015 if (!gimple_duplicate_loop_to_header_edge (loop
, loop_preheader_edge (loop
),
1018 DLTHE_FLAG_UPDATE_FREQ
1019 | DLTHE_FLAG_COMPLETTE_PEEL
))
1021 free_original_copy_tables ();
1025 FOR_EACH_VEC_ELT (to_remove
, i
, e
)
1027 bool ok
= remove_path (e
);
1031 free_original_copy_tables ();
1032 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
1034 fprintf (dump_file
, "Peeled loop %d, %i times.\n",
1035 loop
->num
, (int) npeel
);
1037 if (loop
->any_upper_bound
)
1038 loop
->nb_iterations_upper_bound
-= npeel
;
1039 if (loop
->any_likely_upper_bound
)
1040 loop
->nb_iterations_likely_upper_bound
-= npeel
;
1041 loop
->nb_iterations_estimate
= 0;
1042 /* Make sure to mark loop cold so we do not try to peel it more. */
1043 scale_loop_profile (loop
, 1, 0);
1044 loop
->header
->count
= 0;
1047 /* Adds a canonical induction variable to LOOP if suitable.
1048 CREATE_IV is true if we may create a new iv. UL determines
1049 which loops we are allowed to completely unroll. If TRY_EVAL is true, we try
1050 to determine the number of iterations of a loop by direct evaluation.
1051 Returns true if cfg is changed. */
1054 canonicalize_loop_induction_variables (struct loop
*loop
,
1055 bool create_iv
, enum unroll_level ul
,
1060 HOST_WIDE_INT maxiter
;
1061 bool modified
= false;
1062 location_t locus
= UNKNOWN_LOCATION
;
1064 niter
= number_of_latch_executions (loop
);
1065 exit
= single_exit (loop
);
1066 if (TREE_CODE (niter
) == INTEGER_CST
)
1067 locus
= gimple_location (last_stmt (exit
->src
));
1070 /* If the loop has more than one exit, try checking all of them
1071 for # of iterations determinable through scev. */
1073 niter
= find_loop_niter (loop
, &exit
);
1075 /* Finally if everything else fails, try brute force evaluation. */
1077 && (chrec_contains_undetermined (niter
)
1078 || TREE_CODE (niter
) != INTEGER_CST
))
1079 niter
= find_loop_niter_by_eval (loop
, &exit
);
1082 locus
= gimple_location (last_stmt (exit
->src
));
1084 if (TREE_CODE (niter
) != INTEGER_CST
)
1088 /* We work exceptionally hard here to estimate the bound
1089 by find_loop_niter_by_eval. Be sure to keep it for future. */
1090 if (niter
&& TREE_CODE (niter
) == INTEGER_CST
)
1092 record_niter_bound (loop
, wi::to_widest (niter
),
1093 exit
== single_likely_exit (loop
), true);
1096 /* Force re-computation of loop bounds so we can remove redundant exits. */
1097 maxiter
= max_loop_iterations_int (loop
);
1099 if (dump_file
&& (dump_flags
& TDF_DETAILS
)
1100 && TREE_CODE (niter
) == INTEGER_CST
)
1102 fprintf (dump_file
, "Loop %d iterates ", loop
->num
);
1103 print_generic_expr (dump_file
, niter
, TDF_SLIM
);
1104 fprintf (dump_file
, " times.\n");
1106 if (dump_file
&& (dump_flags
& TDF_DETAILS
)
1109 fprintf (dump_file
, "Loop %d iterates at most %i times.\n", loop
->num
,
1112 if (dump_file
&& (dump_flags
& TDF_DETAILS
)
1113 && likely_max_loop_iterations_int (loop
) >= 0)
1115 fprintf (dump_file
, "Loop likely %d iterates at most %i times.\n", loop
->num
,
1116 (int)likely_max_loop_iterations_int (loop
));
1119 /* Remove exits that are known to be never taken based on loop bound.
1120 Needs to be called after compilation of max_loop_iterations_int that
1121 populates the loop bounds. */
1122 modified
|= remove_redundant_iv_tests (loop
);
1124 if (try_unroll_loop_completely (loop
, exit
, niter
, ul
, maxiter
, locus
))
1128 && niter
&& !chrec_contains_undetermined (niter
)
1129 && exit
&& just_once_each_iteration_p (loop
, exit
->src
))
1130 create_canonical_iv (loop
, exit
, niter
);
1133 modified
|= try_peel_loop (loop
, exit
, niter
, maxiter
);
1138 /* The main entry point of the pass. Adds canonical induction variables
1139 to the suitable loops. */
1142 canonicalize_induction_variables (void)
1145 bool changed
= false;
1146 bool irred_invalidated
= false;
1147 bitmap loop_closed_ssa_invalidated
= BITMAP_ALLOC (NULL
);
1149 free_numbers_of_iterations_estimates (cfun
);
1150 estimate_numbers_of_iterations ();
1152 FOR_EACH_LOOP (loop
, LI_FROM_INNERMOST
)
1154 changed
|= canonicalize_loop_induction_variables (loop
,
1155 true, UL_SINGLE_ITER
,
1158 gcc_assert (!need_ssa_update_p (cfun
));
1160 unloop_loops (loop_closed_ssa_invalidated
, &irred_invalidated
);
1161 if (irred_invalidated
1162 && loops_state_satisfies_p (LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS
))
1163 mark_irreducible_loops ();
1165 /* Clean up the information about numbers of iterations, since brute force
1166 evaluation could reveal new information. */
1169 if (!bitmap_empty_p (loop_closed_ssa_invalidated
))
1171 gcc_checking_assert (loops_state_satisfies_p (LOOP_CLOSED_SSA
));
1172 rewrite_into_loop_closed_ssa (NULL
, TODO_update_ssa
);
1174 BITMAP_FREE (loop_closed_ssa_invalidated
);
1177 return TODO_cleanup_cfg
;
1181 /* Propagate constant SSA_NAMEs defined in basic block BB. */
1184 propagate_constants_for_unrolling (basic_block bb
)
1186 /* Look for degenerate PHI nodes with constant argument. */
1187 for (gphi_iterator gsi
= gsi_start_phis (bb
); !gsi_end_p (gsi
); )
1189 gphi
*phi
= gsi
.phi ();
1190 tree result
= gimple_phi_result (phi
);
1191 tree arg
= gimple_phi_arg_def (phi
, 0);
1193 if (! SSA_NAME_OCCURS_IN_ABNORMAL_PHI (result
)
1194 && gimple_phi_num_args (phi
) == 1
1195 && TREE_CODE (arg
) == INTEGER_CST
)
1197 replace_uses_by (result
, arg
);
1198 gsi_remove (&gsi
, true);
1199 release_ssa_name (result
);
1205 /* Look for assignments to SSA names with constant RHS. */
1206 for (gimple_stmt_iterator gsi
= gsi_start_bb (bb
); !gsi_end_p (gsi
); )
1208 gimple
*stmt
= gsi_stmt (gsi
);
1211 if (is_gimple_assign (stmt
)
1212 && gimple_assign_rhs_code (stmt
) == INTEGER_CST
1213 && (lhs
= gimple_assign_lhs (stmt
), TREE_CODE (lhs
) == SSA_NAME
)
1214 && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs
))
1216 replace_uses_by (lhs
, gimple_assign_rhs1 (stmt
));
1217 gsi_remove (&gsi
, true);
1218 release_ssa_name (lhs
);
1225 /* Process loops from innermost to outer, stopping at the innermost
1226 loop we unrolled. */
1229 tree_unroll_loops_completely_1 (bool may_increase_size
, bool unroll_outer
,
1230 vec
<loop_p
, va_heap
>& father_stack
,
1233 struct loop
*loop_father
;
1234 bool changed
= false;
1236 enum unroll_level ul
;
1238 /* Process inner loops first. */
1239 for (inner
= loop
->inner
; inner
!= NULL
; inner
= inner
->next
)
1240 changed
|= tree_unroll_loops_completely_1 (may_increase_size
,
1241 unroll_outer
, father_stack
,
1244 /* If we changed an inner loop we cannot process outer loops in this
1245 iteration because SSA form is not up-to-date. Continue with
1246 siblings of outer loops instead. */
1250 /* Don't unroll #pragma omp simd loops until the vectorizer
1251 attempts to vectorize those. */
1252 if (loop
->force_vectorize
)
1255 /* Try to unroll this loop. */
1256 loop_father
= loop_outer (loop
);
1260 if (may_increase_size
&& optimize_loop_nest_for_speed_p (loop
)
1261 /* Unroll outermost loops only if asked to do so or they do
1262 not cause code growth. */
1263 && (unroll_outer
|| loop_outer (loop_father
)))
1268 if (canonicalize_loop_induction_variables
1269 (loop
, false, ul
, !flag_tree_loop_ivcanon
))
1271 /* If we'll continue unrolling, we need to propagate constants
1272 within the new basic blocks to fold away induction variable
1273 computations; otherwise, the size might blow up before the
1274 iteration is complete and the IR eventually cleaned up. */
1275 if (loop_outer (loop_father
) && !loop_father
->aux
)
1277 father_stack
.safe_push (loop_father
);
1278 loop_father
->aux
= loop_father
;
1287 /* Unroll LOOPS completely if they iterate just few times. Unless
1288 MAY_INCREASE_SIZE is true, perform the unrolling only if the
1289 size of the code does not increase. */
1292 tree_unroll_loops_completely (bool may_increase_size
, bool unroll_outer
)
1294 auto_vec
<loop_p
, 16> father_stack
;
1297 bool irred_invalidated
= false;
1302 bitmap loop_closed_ssa_invalidated
= NULL
;
1304 if (loops_state_satisfies_p (LOOP_CLOSED_SSA
))
1305 loop_closed_ssa_invalidated
= BITMAP_ALLOC (NULL
);
1307 free_numbers_of_iterations_estimates (cfun
);
1308 estimate_numbers_of_iterations ();
1310 changed
= tree_unroll_loops_completely_1 (may_increase_size
,
1311 unroll_outer
, father_stack
,
1312 current_loops
->tree_root
);
1318 /* Be sure to skip unlooped loops while procesing father_stack
1320 FOR_EACH_VEC_ELT (loops_to_unloop
, i
, iter
)
1321 (*iter
)->aux
= NULL
;
1322 FOR_EACH_VEC_ELT (father_stack
, i
, iter
)
1325 unloop_loops (loop_closed_ssa_invalidated
, &irred_invalidated
);
1327 /* We can not use TODO_update_ssa_no_phi because VOPS gets confused. */
1328 if (loop_closed_ssa_invalidated
1329 && !bitmap_empty_p (loop_closed_ssa_invalidated
))
1330 rewrite_into_loop_closed_ssa (loop_closed_ssa_invalidated
,
1333 update_ssa (TODO_update_ssa
);
1335 /* Propagate the constants within the new basic blocks. */
1336 FOR_EACH_VEC_ELT (father_stack
, i
, iter
)
1340 basic_block
*body
= get_loop_body_in_dom_order (*iter
);
1341 for (j
= 0; j
< (*iter
)->num_nodes
; j
++)
1342 propagate_constants_for_unrolling (body
[j
]);
1344 (*iter
)->aux
= NULL
;
1346 father_stack
.truncate (0);
1348 /* This will take care of removing completely unrolled loops
1349 from the loop structures so we can continue unrolling now
1351 if (cleanup_tree_cfg ())
1352 update_ssa (TODO_update_ssa_only_virtuals
);
1354 /* Clean up the information about numbers of iterations, since
1355 complete unrolling might have invalidated it. */
1357 if (flag_checking
&& loops_state_satisfies_p (LOOP_CLOSED_SSA
))
1358 verify_loop_closed_ssa (true);
1360 if (loop_closed_ssa_invalidated
)
1361 BITMAP_FREE (loop_closed_ssa_invalidated
);
1364 && ++iteration
<= PARAM_VALUE (PARAM_MAX_UNROLL_ITERATIONS
));
1366 father_stack
.release ();
1368 if (irred_invalidated
1369 && loops_state_satisfies_p (LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS
))
1370 mark_irreducible_loops ();
1375 /* Canonical induction variable creation pass. */
1379 const pass_data pass_data_iv_canon
=
1381 GIMPLE_PASS
, /* type */
1382 "ivcanon", /* name */
1383 OPTGROUP_LOOP
, /* optinfo_flags */
1384 TV_TREE_LOOP_IVCANON
, /* tv_id */
1385 ( PROP_cfg
| PROP_ssa
), /* properties_required */
1386 0, /* properties_provided */
1387 0, /* properties_destroyed */
1388 0, /* todo_flags_start */
1389 0, /* todo_flags_finish */
1392 class pass_iv_canon
: public gimple_opt_pass
1395 pass_iv_canon (gcc::context
*ctxt
)
1396 : gimple_opt_pass (pass_data_iv_canon
, ctxt
)
1399 /* opt_pass methods: */
1400 virtual bool gate (function
*) { return flag_tree_loop_ivcanon
!= 0; }
1401 virtual unsigned int execute (function
*fun
);
1403 }; // class pass_iv_canon
1406 pass_iv_canon::execute (function
*fun
)
1408 if (number_of_loops (fun
) <= 1)
1411 return canonicalize_induction_variables ();
1417 make_pass_iv_canon (gcc::context
*ctxt
)
1419 return new pass_iv_canon (ctxt
);
1422 /* Complete unrolling of loops. */
1426 const pass_data pass_data_complete_unroll
=
1428 GIMPLE_PASS
, /* type */
1429 "cunroll", /* name */
1430 OPTGROUP_LOOP
, /* optinfo_flags */
1431 TV_COMPLETE_UNROLL
, /* tv_id */
1432 ( PROP_cfg
| PROP_ssa
), /* properties_required */
1433 0, /* properties_provided */
1434 0, /* properties_destroyed */
1435 0, /* todo_flags_start */
1436 0, /* todo_flags_finish */
1439 class pass_complete_unroll
: public gimple_opt_pass
1442 pass_complete_unroll (gcc::context
*ctxt
)
1443 : gimple_opt_pass (pass_data_complete_unroll
, ctxt
)
1446 /* opt_pass methods: */
1447 virtual unsigned int execute (function
*);
1449 }; // class pass_complete_unroll
1452 pass_complete_unroll::execute (function
*fun
)
1454 if (number_of_loops (fun
) <= 1)
1457 return tree_unroll_loops_completely (flag_unroll_loops
1459 || optimize
>= 3, true);
1465 make_pass_complete_unroll (gcc::context
*ctxt
)
1467 return new pass_complete_unroll (ctxt
);
1470 /* Complete unrolling of inner loops. */
1474 const pass_data pass_data_complete_unrolli
=
1476 GIMPLE_PASS
, /* type */
1477 "cunrolli", /* name */
1478 OPTGROUP_LOOP
, /* optinfo_flags */
1479 TV_COMPLETE_UNROLL
, /* tv_id */
1480 ( PROP_cfg
| PROP_ssa
), /* properties_required */
1481 0, /* properties_provided */
1482 0, /* properties_destroyed */
1483 0, /* todo_flags_start */
1484 0, /* todo_flags_finish */
1487 class pass_complete_unrolli
: public gimple_opt_pass
1490 pass_complete_unrolli (gcc::context
*ctxt
)
1491 : gimple_opt_pass (pass_data_complete_unrolli
, ctxt
)
1494 /* opt_pass methods: */
1495 virtual bool gate (function
*) { return optimize
>= 2; }
1496 virtual unsigned int execute (function
*);
1498 }; // class pass_complete_unrolli
1501 pass_complete_unrolli::execute (function
*fun
)
1505 loop_optimizer_init (LOOPS_NORMAL
1506 | LOOPS_HAVE_RECORDED_EXITS
);
1507 if (number_of_loops (fun
) > 1)
1510 ret
= tree_unroll_loops_completely (optimize
>= 3, false);
1511 free_numbers_of_iterations_estimates (fun
);
1514 loop_optimizer_finalize ();
1522 make_pass_complete_unrolli (gcc::context
*ctxt
)
1524 return new pass_complete_unrolli (ctxt
);