1 /* Induction variable canonicalization and loop peeling.
2 Copyright (C) 2004-2017 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
)
160 if (is_gimple_min_invariant (op
))
163 /* We can still fold accesses to constant arrays when index is known. */
164 if (TREE_CODE (op
) != SSA_NAME
)
168 /* First make fast look if we see constant array inside. */
169 while (handled_component_p (base
))
170 base
= TREE_OPERAND (base
, 0);
172 && ctor_for_folding (base
) != error_mark_node
)
173 || CONSTANT_CLASS_P (base
))
175 /* If so, see if we understand all the indices. */
177 while (handled_component_p (base
))
179 if (TREE_CODE (base
) == ARRAY_REF
180 && !constant_after_peeling (TREE_OPERAND (base
, 1), stmt
, loop
))
182 base
= TREE_OPERAND (base
, 0);
189 /* Induction variables are constants when defined in loop. */
190 if (loop_containing_stmt (stmt
) != loop
)
192 tree ev
= analyze_scalar_evolution (loop
, op
);
193 if (chrec_contains_undetermined (ev
)
194 || chrec_contains_symbols (ev
))
199 /* Computes an estimated number of insns in LOOP.
200 EXIT (if non-NULL) is an exite edge that will be eliminated in all but last
201 iteration of the loop.
202 EDGE_TO_CANCEL (if non-NULL) is an non-exit edge eliminated in the last iteration
204 Return results in SIZE, estimate benefits for complete unrolling exiting by EXIT.
205 Stop estimating after UPPER_BOUND is met. Return true in this case. */
208 tree_estimate_loop_size (struct loop
*loop
, edge exit
, edge edge_to_cancel
,
209 struct loop_size
*size
, int upper_bound
)
211 basic_block
*body
= get_loop_body (loop
);
212 gimple_stmt_iterator gsi
;
215 vec
<basic_block
> path
= get_loop_hot_path (loop
);
218 size
->eliminated_by_peeling
= 0;
219 size
->last_iteration
= 0;
220 size
->last_iteration_eliminated_by_peeling
= 0;
221 size
->num_pure_calls_on_hot_path
= 0;
222 size
->num_non_pure_calls_on_hot_path
= 0;
223 size
->non_call_stmts_on_hot_path
= 0;
224 size
->num_branches_on_hot_path
= 0;
225 size
->constant_iv
= 0;
227 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
228 fprintf (dump_file
, "Estimating sizes for loop %i\n", loop
->num
);
229 for (i
= 0; i
< loop
->num_nodes
; i
++)
231 if (edge_to_cancel
&& body
[i
] != edge_to_cancel
->src
232 && dominated_by_p (CDI_DOMINATORS
, body
[i
], edge_to_cancel
->src
))
236 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
237 fprintf (dump_file
, " BB: %i, after_exit: %i\n", body
[i
]->index
,
240 for (gsi
= gsi_start_bb (body
[i
]); !gsi_end_p (gsi
); gsi_next (&gsi
))
242 gimple
*stmt
= gsi_stmt (gsi
);
243 int num
= estimate_num_insns (stmt
, &eni_size_weights
);
244 bool likely_eliminated
= false;
245 bool likely_eliminated_last
= false;
246 bool likely_eliminated_peeled
= false;
248 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
250 fprintf (dump_file
, " size: %3i ", num
);
251 print_gimple_stmt (dump_file
, gsi_stmt (gsi
), 0);
254 /* Look for reasons why we might optimize this stmt away. */
256 if (!gimple_has_side_effects (stmt
))
258 /* Exit conditional. */
259 if (exit
&& body
[i
] == exit
->src
260 && stmt
== last_stmt (exit
->src
))
262 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
263 fprintf (dump_file
, " Exit condition will be eliminated "
264 "in peeled copies.\n");
265 likely_eliminated_peeled
= true;
267 if (edge_to_cancel
&& body
[i
] == edge_to_cancel
->src
268 && stmt
== last_stmt (edge_to_cancel
->src
))
270 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
271 fprintf (dump_file
, " Exit condition will be eliminated "
273 likely_eliminated_last
= true;
275 /* Sets of IV variables */
276 if (gimple_code (stmt
) == GIMPLE_ASSIGN
277 && constant_after_peeling (gimple_assign_lhs (stmt
), stmt
, loop
))
279 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
280 fprintf (dump_file
, " Induction variable computation will"
281 " be folded away.\n");
282 likely_eliminated
= true;
284 /* Assignments of IV variables. */
285 else if (gimple_code (stmt
) == GIMPLE_ASSIGN
286 && TREE_CODE (gimple_assign_lhs (stmt
)) == SSA_NAME
287 && constant_after_peeling (gimple_assign_rhs1 (stmt
),
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
))
296 " Constant expression will be folded away.\n");
297 likely_eliminated
= true;
300 else if ((gimple_code (stmt
) == GIMPLE_COND
301 && constant_after_peeling (gimple_cond_lhs (stmt
), stmt
,
303 && constant_after_peeling (gimple_cond_rhs (stmt
), stmt
,
305 /* We don't simplify all constant compares so make sure
306 they are not both constant already. See PR70288. */
307 && (! is_gimple_min_invariant (gimple_cond_lhs (stmt
))
308 || ! is_gimple_min_invariant
309 (gimple_cond_rhs (stmt
))))
310 || (gimple_code (stmt
) == GIMPLE_SWITCH
311 && constant_after_peeling (gimple_switch_index (
315 && ! is_gimple_min_invariant
317 (as_a
<gswitch
*> (stmt
)))))
319 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
320 fprintf (dump_file
, " Constant conditional.\n");
321 likely_eliminated
= true;
325 size
->overall
+= num
;
326 if (likely_eliminated
|| likely_eliminated_peeled
)
327 size
->eliminated_by_peeling
+= num
;
330 size
->last_iteration
+= num
;
331 if (likely_eliminated
|| likely_eliminated_last
)
332 size
->last_iteration_eliminated_by_peeling
+= num
;
334 if ((size
->overall
* 3 / 2 - size
->eliminated_by_peeling
335 - size
->last_iteration_eliminated_by_peeling
) > upper_bound
)
343 while (path
.length ())
345 basic_block bb
= path
.pop ();
346 for (gsi
= gsi_start_bb (bb
); !gsi_end_p (gsi
); gsi_next (&gsi
))
348 gimple
*stmt
= gsi_stmt (gsi
);
349 if (gimple_code (stmt
) == GIMPLE_CALL
350 && !gimple_inexpensive_call_p (as_a
<gcall
*> (stmt
)))
352 int flags
= gimple_call_flags (stmt
);
353 if (flags
& (ECF_PURE
| ECF_CONST
))
354 size
->num_pure_calls_on_hot_path
++;
356 size
->num_non_pure_calls_on_hot_path
++;
357 size
->num_branches_on_hot_path
++;
359 /* Count inexpensive calls as non-calls, because they will likely
361 else if (gimple_code (stmt
) != GIMPLE_DEBUG
)
362 size
->non_call_stmts_on_hot_path
++;
363 if (((gimple_code (stmt
) == GIMPLE_COND
364 && (!constant_after_peeling (gimple_cond_lhs (stmt
), stmt
, loop
)
365 || constant_after_peeling (gimple_cond_rhs (stmt
), stmt
,
367 || (gimple_code (stmt
) == GIMPLE_SWITCH
368 && !constant_after_peeling (gimple_switch_index (
369 as_a
<gswitch
*> (stmt
)),
371 && (!exit
|| bb
!= exit
->src
))
372 size
->num_branches_on_hot_path
++;
376 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
377 fprintf (dump_file
, "size: %i-%i, last_iteration: %i-%i\n", size
->overall
,
378 size
->eliminated_by_peeling
, size
->last_iteration
,
379 size
->last_iteration_eliminated_by_peeling
);
385 /* Estimate number of insns of completely unrolled loop.
386 It is (NUNROLL + 1) * size of loop body with taking into account
387 the fact that in last copy everything after exit conditional
388 is dead and that some instructions will be eliminated after
391 Loop body is likely going to simplify further, this is difficult
392 to guess, we just decrease the result by 1/3. */
394 static unsigned HOST_WIDE_INT
395 estimated_unrolled_size (struct loop_size
*size
,
396 unsigned HOST_WIDE_INT nunroll
)
398 HOST_WIDE_INT unr_insns
= ((nunroll
)
399 * (HOST_WIDE_INT
) (size
->overall
400 - size
->eliminated_by_peeling
));
403 unr_insns
+= size
->last_iteration
- size
->last_iteration_eliminated_by_peeling
;
405 unr_insns
= unr_insns
* 2 / 3;
412 /* Loop LOOP is known to not loop. See if there is an edge in the loop
413 body that can be remove to make the loop to always exit and at
414 the same time it does not make any code potentially executed
415 during the last iteration dead.
417 After complete unrolling we still may get rid of the conditional
418 on the exit in the last copy even if we have no idea what it does.
419 This is quite common case for loops of form
425 Here we prove the loop to iterate 5 times but we do not know
426 it from induction variable.
428 For now we handle only simple case where there is exit condition
429 just before the latch block and the latch block contains no statements
430 with side effect that may otherwise terminate the execution of loop
431 (such as by EH or by terminating the program or longjmp).
433 In the general case we may want to cancel the paths leading to statements
434 loop-niter identified as having undefined effect in the last iteration.
435 The other cases are hopefully rare and will be cleaned up later. */
438 loop_edge_to_cancel (struct loop
*loop
)
443 gimple_stmt_iterator gsi
;
445 /* We want only one predecestor of the loop. */
446 if (EDGE_COUNT (loop
->latch
->preds
) > 1)
449 exits
= get_loop_exit_edges (loop
);
451 FOR_EACH_VEC_ELT (exits
, i
, edge_to_cancel
)
453 /* Find the other edge than the loop exit
454 leaving the conditoinal. */
455 if (EDGE_COUNT (edge_to_cancel
->src
->succs
) != 2)
457 if (EDGE_SUCC (edge_to_cancel
->src
, 0) == edge_to_cancel
)
458 edge_to_cancel
= EDGE_SUCC (edge_to_cancel
->src
, 1);
460 edge_to_cancel
= EDGE_SUCC (edge_to_cancel
->src
, 0);
462 /* We only can handle conditionals. */
463 if (!(edge_to_cancel
->flags
& (EDGE_TRUE_VALUE
| EDGE_FALSE_VALUE
)))
466 /* We should never have conditionals in the loop latch. */
467 gcc_assert (edge_to_cancel
->dest
!= loop
->header
);
469 /* Check that it leads to loop latch. */
470 if (edge_to_cancel
->dest
!= loop
->latch
)
475 /* Verify that the code in loop latch does nothing that may end program
476 execution without really reaching the exit. This may include
477 non-pure/const function calls, EH statements, volatile ASMs etc. */
478 for (gsi
= gsi_start_bb (loop
->latch
); !gsi_end_p (gsi
); gsi_next (&gsi
))
479 if (gimple_has_side_effects (gsi_stmt (gsi
)))
481 return edge_to_cancel
;
487 /* Remove all tests for exits that are known to be taken after LOOP was
488 peeled NPEELED times. Put gcc_unreachable before every statement
489 known to not be executed. */
492 remove_exits_and_undefined_stmts (struct loop
*loop
, unsigned int npeeled
)
494 struct nb_iter_bound
*elt
;
495 bool changed
= false;
497 for (elt
= loop
->bounds
; elt
; elt
= elt
->next
)
499 /* If statement is known to be undefined after peeling, turn it
500 into unreachable (or trap when debugging experience is supposed
503 && wi::ltu_p (elt
->bound
, npeeled
))
505 gimple_stmt_iterator gsi
= gsi_for_stmt (elt
->stmt
);
506 gcall
*stmt
= gimple_build_call
507 (builtin_decl_implicit (BUILT_IN_UNREACHABLE
), 0);
508 gimple_set_location (stmt
, gimple_location (elt
->stmt
));
509 gsi_insert_before (&gsi
, stmt
, GSI_NEW_STMT
);
510 split_block (gimple_bb (stmt
), stmt
);
512 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
514 fprintf (dump_file
, "Forced statement unreachable: ");
515 print_gimple_stmt (dump_file
, elt
->stmt
, 0);
518 /* If we know the exit will be taken after peeling, update. */
519 else if (elt
->is_exit
520 && wi::leu_p (elt
->bound
, npeeled
))
522 basic_block bb
= gimple_bb (elt
->stmt
);
523 edge exit_edge
= EDGE_SUCC (bb
, 0);
525 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
527 fprintf (dump_file
, "Forced exit to be taken: ");
528 print_gimple_stmt (dump_file
, elt
->stmt
, 0);
530 if (!loop_exit_edge_p (loop
, exit_edge
))
531 exit_edge
= EDGE_SUCC (bb
, 1);
532 exit_edge
->probability
= profile_probability::always ();
533 gcc_checking_assert (loop_exit_edge_p (loop
, exit_edge
));
534 gcond
*cond_stmt
= as_a
<gcond
*> (elt
->stmt
);
535 if (exit_edge
->flags
& EDGE_TRUE_VALUE
)
536 gimple_cond_make_true (cond_stmt
);
538 gimple_cond_make_false (cond_stmt
);
539 update_stmt (cond_stmt
);
546 /* Remove all exits that are known to be never taken because of the loop bound
550 remove_redundant_iv_tests (struct loop
*loop
)
552 struct nb_iter_bound
*elt
;
553 bool changed
= false;
555 if (!loop
->any_upper_bound
)
557 for (elt
= loop
->bounds
; elt
; elt
= elt
->next
)
559 /* Exit is pointless if it won't be taken before loop reaches
561 if (elt
->is_exit
&& loop
->any_upper_bound
562 && wi::ltu_p (loop
->nb_iterations_upper_bound
, elt
->bound
))
564 basic_block bb
= gimple_bb (elt
->stmt
);
565 edge exit_edge
= EDGE_SUCC (bb
, 0);
566 struct tree_niter_desc niter
;
568 if (!loop_exit_edge_p (loop
, exit_edge
))
569 exit_edge
= EDGE_SUCC (bb
, 1);
571 /* Only when we know the actual number of iterations, not
572 just a bound, we can remove the exit. */
573 if (!number_of_iterations_exit (loop
, exit_edge
,
574 &niter
, false, false)
575 || !integer_onep (niter
.assumptions
)
576 || !integer_zerop (niter
.may_be_zero
)
578 || TREE_CODE (niter
.niter
) != INTEGER_CST
579 || !wi::ltu_p (loop
->nb_iterations_upper_bound
,
580 wi::to_widest (niter
.niter
)))
583 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
585 fprintf (dump_file
, "Removed pointless exit: ");
586 print_gimple_stmt (dump_file
, elt
->stmt
, 0);
588 gcond
*cond_stmt
= as_a
<gcond
*> (elt
->stmt
);
589 if (exit_edge
->flags
& EDGE_TRUE_VALUE
)
590 gimple_cond_make_false (cond_stmt
);
592 gimple_cond_make_true (cond_stmt
);
593 update_stmt (cond_stmt
);
600 /* Stores loops that will be unlooped and edges that will be removed
601 after we process whole loop tree. */
602 static vec
<loop_p
> loops_to_unloop
;
603 static vec
<int> loops_to_unloop_nunroll
;
604 static vec
<edge
> edges_to_remove
;
605 /* Stores loops that has been peeled. */
606 static bitmap peeled_loops
;
608 /* Cancel all fully unrolled loops by putting __builtin_unreachable
610 We do it after all unrolling since unlooping moves basic blocks
611 across loop boundaries trashing loop closed SSA form as well
612 as SCEV info needed to be intact during unrolling.
614 IRRED_INVALIDATED is used to bookkeep if information about
615 irreducible regions may become invalid as a result
616 of the transformation.
617 LOOP_CLOSED_SSA_INVALIDATED is used to bookkepp the case
618 when we need to go into loop closed SSA form. */
621 unloop_loops (bitmap loop_closed_ssa_invalidated
,
622 bool *irred_invalidated
)
624 while (loops_to_unloop
.length ())
626 struct loop
*loop
= loops_to_unloop
.pop ();
627 int n_unroll
= loops_to_unloop_nunroll
.pop ();
628 basic_block latch
= loop
->latch
;
629 edge latch_edge
= loop_latch_edge (loop
);
630 int flags
= latch_edge
->flags
;
631 location_t locus
= latch_edge
->goto_locus
;
633 gimple_stmt_iterator gsi
;
635 remove_exits_and_undefined_stmts (loop
, n_unroll
);
637 /* Unloop destroys the latch edge. */
638 unloop (loop
, irred_invalidated
, loop_closed_ssa_invalidated
);
640 /* Create new basic block for the latch edge destination and wire
642 stmt
= gimple_build_call (builtin_decl_implicit (BUILT_IN_UNREACHABLE
), 0);
643 latch_edge
= make_edge (latch
, create_basic_block (NULL
, NULL
, latch
), flags
);
644 latch_edge
->probability
= profile_probability::never ();
645 latch_edge
->flags
|= flags
;
646 latch_edge
->goto_locus
= locus
;
648 add_bb_to_loop (latch_edge
->dest
, current_loops
->tree_root
);
649 latch_edge
->dest
->count
= profile_count::zero ();
650 set_immediate_dominator (CDI_DOMINATORS
, latch_edge
->dest
, latch_edge
->src
);
652 gsi
= gsi_start_bb (latch_edge
->dest
);
653 gsi_insert_after (&gsi
, stmt
, GSI_NEW_STMT
);
655 loops_to_unloop
.release ();
656 loops_to_unloop_nunroll
.release ();
658 /* Remove edges in peeled copies. */
661 FOR_EACH_VEC_ELT (edges_to_remove
, i
, e
)
663 bool ok
= remove_path (e
, irred_invalidated
, loop_closed_ssa_invalidated
);
666 edges_to_remove
.release ();
669 /* Tries to unroll LOOP completely, i.e. NITER times.
670 UL determines which loops we are allowed to unroll.
671 EXIT is the exit of the loop that should be eliminated.
672 MAXITER specfy bound on number of iterations, -1 if it is
673 not known or too large for HOST_WIDE_INT. The location
674 LOCUS corresponding to the loop is used when emitting
675 a summary of the unroll to the dump file. */
678 try_unroll_loop_completely (struct loop
*loop
,
679 edge exit
, tree niter
,
680 enum unroll_level ul
,
681 HOST_WIDE_INT maxiter
,
684 unsigned HOST_WIDE_INT n_unroll
= 0;
685 bool n_unroll_found
= false;
686 edge edge_to_cancel
= NULL
;
688 /* See if we proved number of iterations to be low constant.
690 EXIT is an edge that will be removed in all but last iteration of
693 EDGE_TO_CACNEL is an edge that will be removed from the last iteration
694 of the unrolled sequence and is expected to make the final loop not
697 If the number of execution of loop is determined by standard induction
698 variable test, then EXIT and EDGE_TO_CANCEL are the two edges leaving
700 if (tree_fits_uhwi_p (niter
))
702 n_unroll
= tree_to_uhwi (niter
);
703 n_unroll_found
= true;
704 edge_to_cancel
= EDGE_SUCC (exit
->src
, 0);
705 if (edge_to_cancel
== exit
)
706 edge_to_cancel
= EDGE_SUCC (exit
->src
, 1);
708 /* We do not know the number of iterations and thus we can not eliminate
713 /* See if we can improve our estimate by using recorded loop bounds. */
715 && (!n_unroll_found
|| (unsigned HOST_WIDE_INT
)maxiter
< n_unroll
))
718 n_unroll_found
= true;
719 /* Loop terminates before the IV variable test, so we can not
720 remove it in the last iteration. */
721 edge_to_cancel
= NULL
;
728 && n_unroll
> (unsigned) PARAM_VALUE (PARAM_MAX_COMPLETELY_PEEL_TIMES
))
730 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
731 fprintf (dump_file
, "Not unrolling loop %d "
732 "(--param max-completely-peel-times limit reached).\n",
738 edge_to_cancel
= loop_edge_to_cancel (loop
);
742 if (ul
== UL_SINGLE_ITER
)
747 /* If the unrolling factor is too large, bail out. */
748 if (n_unroll
> (unsigned)loop
->unroll
)
750 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
752 "Not unrolling loop %d: "
753 "user didn't want it unrolled completely.\n",
760 struct loop_size size
;
761 /* EXIT can be removed only if we are sure it passes first N_UNROLL
763 bool remove_exit
= (exit
&& niter
764 && TREE_CODE (niter
) == INTEGER_CST
765 && wi::leu_p (n_unroll
, wi::to_widest (niter
)));
767 = tree_estimate_loop_size
768 (loop
, remove_exit
? exit
: NULL
, edge_to_cancel
, &size
,
769 PARAM_VALUE (PARAM_MAX_COMPLETELY_PEELED_INSNS
));
772 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
773 fprintf (dump_file
, "Not unrolling loop %d: it is too large.\n",
778 unsigned HOST_WIDE_INT ninsns
= size
.overall
;
779 unsigned HOST_WIDE_INT unr_insns
780 = estimated_unrolled_size (&size
, n_unroll
);
781 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
783 fprintf (dump_file
, " Loop size: %d\n", (int) ninsns
);
784 fprintf (dump_file
, " Estimated size after unrolling: %d\n",
788 /* If the code is going to shrink, we don't need to be extra
789 cautious on guessing if the unrolling is going to be
792 /* If there is IV variable that will become constant, we
793 save one instruction in the loop prologue we do not
794 account otherwise. */
795 <= ninsns
+ (size
.constant_iv
!= false))
797 /* We unroll only inner loops, because we do not consider it
798 profitable otheriwse. We still can cancel loopback edge
799 of not rolling loop; this is always a good idea. */
800 else if (ul
== UL_NO_GROWTH
)
802 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
803 fprintf (dump_file
, "Not unrolling loop %d: size would grow.\n",
807 /* Outer loops tend to be less interesting candidates for
808 complete unrolling unless we can do a lot of propagation
809 into the inner loop body. For now we disable outer loop
810 unrolling when the code would grow. */
811 else if (loop
->inner
)
813 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
814 fprintf (dump_file
, "Not unrolling loop %d: "
815 "it is not innermost and code would grow.\n",
819 /* If there is call on a hot path through the loop, then
820 there is most probably not much to optimize. */
821 else if (size
.num_non_pure_calls_on_hot_path
)
823 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
824 fprintf (dump_file
, "Not unrolling loop %d: "
825 "contains call and code would grow.\n",
829 /* If there is pure/const call in the function, then we can
830 still optimize the unrolled loop body if it contains some
831 other interesting code than the calls and code storing or
832 cumulating the return value. */
833 else if (size
.num_pure_calls_on_hot_path
834 /* One IV increment, one test, one ivtmp store and
835 one useful stmt. That is about minimal loop
837 && (size
.non_call_stmts_on_hot_path
838 <= 3 + size
.num_pure_calls_on_hot_path
))
840 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
841 fprintf (dump_file
, "Not unrolling loop %d: "
842 "contains just pure calls and code would grow.\n",
846 /* Complete unrolling is major win when control flow is
847 removed and one big basic block is created. If the loop
848 contains control flow the optimization may still be a win
849 because of eliminating the loop overhead but it also may
850 blow the branch predictor tables. Limit number of
851 branches on the hot path through the peeled sequence. */
852 else if (size
.num_branches_on_hot_path
* (int)n_unroll
853 > PARAM_VALUE (PARAM_MAX_PEEL_BRANCHES
))
855 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
856 fprintf (dump_file
, "Not unrolling loop %d: "
857 "number of branches on hot path in the unrolled "
858 "sequence reaches --param max-peel-branches limit.\n",
863 > (unsigned) PARAM_VALUE (PARAM_MAX_COMPLETELY_PEELED_INSNS
))
865 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
866 fprintf (dump_file
, "Not unrolling loop %d: "
867 "number of insns in the unrolled sequence reaches "
868 "--param max-completely-peeled-insns limit.\n",
874 initialize_original_copy_tables ();
875 auto_sbitmap
wont_exit (n_unroll
+ 1);
877 && TREE_CODE (niter
) == INTEGER_CST
878 && wi::leu_p (n_unroll
, wi::to_widest (niter
)))
880 bitmap_ones (wont_exit
);
881 if (wi::eq_p (wi::to_widest (niter
), n_unroll
)
883 bitmap_clear_bit (wont_exit
, 0);
888 bitmap_clear (wont_exit
);
891 if (!gimple_duplicate_loop_to_header_edge (loop
, loop_preheader_edge (loop
),
893 exit
, &edges_to_remove
,
894 DLTHE_FLAG_UPDATE_FREQ
895 | DLTHE_FLAG_COMPLETTE_PEEL
))
897 free_original_copy_tables ();
898 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
899 fprintf (dump_file
, "Failed to duplicate the loop\n");
903 free_original_copy_tables ();
906 /* Remove the conditional from the last copy of the loop. */
909 gcond
*cond
= as_a
<gcond
*> (last_stmt (edge_to_cancel
->src
));
910 force_edge_cold (edge_to_cancel
, true);
911 if (edge_to_cancel
->flags
& EDGE_TRUE_VALUE
)
912 gimple_cond_make_false (cond
);
914 gimple_cond_make_true (cond
);
916 /* Do not remove the path, as doing so may remove outer loop and
917 confuse bookkeeping code in tree_unroll_loops_completely. */
920 /* Store the loop for later unlooping and exit removal. */
921 loops_to_unloop
.safe_push (loop
);
922 loops_to_unloop_nunroll
.safe_push (n_unroll
);
924 if (dump_enabled_p ())
927 dump_printf_loc (MSG_OPTIMIZED_LOCATIONS
| TDF_DETAILS
, locus
,
928 "loop turned into non-loop; it never loops\n");
931 dump_printf_loc (MSG_OPTIMIZED_LOCATIONS
| TDF_DETAILS
, locus
,
932 "loop with %d iterations completely unrolled",
934 if (loop
->header
->count
.initialized_p ())
935 dump_printf (MSG_OPTIMIZED_LOCATIONS
| TDF_DETAILS
,
936 " (header execution count %d)",
937 (int)loop
->header
->count
.to_gcov_type ());
938 dump_printf (MSG_OPTIMIZED_LOCATIONS
| TDF_DETAILS
, "\n");
942 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
945 fprintf (dump_file
, "Exit condition of peeled iterations was "
948 fprintf (dump_file
, "Last iteration exit edge was proved true.\n");
950 fprintf (dump_file
, "Latch of last iteration was marked by "
951 "__builtin_unreachable ().\n");
957 /* Return number of instructions after peeling. */
958 static unsigned HOST_WIDE_INT
959 estimated_peeled_sequence_size (struct loop_size
*size
,
960 unsigned HOST_WIDE_INT npeel
)
962 return MAX (npeel
* (HOST_WIDE_INT
) (size
->overall
963 - size
->eliminated_by_peeling
), 1);
966 /* If the loop is expected to iterate N times and is
967 small enough, duplicate the loop body N+1 times before
968 the loop itself. This way the hot path will never
970 Parameters are the same as for try_unroll_loops_completely */
973 try_peel_loop (struct loop
*loop
,
974 edge exit
, tree niter
,
975 HOST_WIDE_INT maxiter
)
978 struct loop_size size
;
982 || PARAM_VALUE (PARAM_MAX_PEEL_TIMES
) <= 0
986 if (bitmap_bit_p (peeled_loops
, loop
->num
))
989 fprintf (dump_file
, "Not peeling: loop is already peeled\n");
993 /* We don't peel loops that will be unrolled as this can duplicate a
994 loop more times than the user requested. */
998 fprintf (dump_file
, "Not peeling: user didn't want it peeled.\n");
1002 /* Peel only innermost loops.
1003 While the code is perfectly capable of peeling non-innermost loops,
1004 the heuristics would probably need some improvements. */
1008 fprintf (dump_file
, "Not peeling: outer loop\n");
1012 if (!optimize_loop_for_speed_p (loop
))
1015 fprintf (dump_file
, "Not peeling: cold loop\n");
1019 /* Check if there is an estimate on the number of iterations. */
1020 npeel
= estimated_loop_iterations_int (loop
);
1022 npeel
= likely_max_loop_iterations_int (loop
);
1026 fprintf (dump_file
, "Not peeling: number of iterations is not "
1030 if (maxiter
>= 0 && maxiter
<= npeel
)
1033 fprintf (dump_file
, "Not peeling: upper bound is known so can "
1034 "unroll completely\n");
1038 /* We want to peel estimated number of iterations + 1 (so we never
1039 enter the loop on quick path). Check against PARAM_MAX_PEEL_TIMES
1040 and be sure to avoid overflows. */
1041 if (npeel
> PARAM_VALUE (PARAM_MAX_PEEL_TIMES
) - 1)
1044 fprintf (dump_file
, "Not peeling: rolls too much "
1045 "(%i + 1 > --param max-peel-times)\n", (int) npeel
);
1050 /* Check peeled loops size. */
1051 tree_estimate_loop_size (loop
, exit
, NULL
, &size
,
1052 PARAM_VALUE (PARAM_MAX_PEELED_INSNS
));
1053 if ((peeled_size
= estimated_peeled_sequence_size (&size
, (int) npeel
))
1054 > PARAM_VALUE (PARAM_MAX_PEELED_INSNS
))
1057 fprintf (dump_file
, "Not peeling: peeled sequence size is too large "
1058 "(%i insns > --param max-peel-insns)", peeled_size
);
1062 /* Duplicate possibly eliminating the exits. */
1063 initialize_original_copy_tables ();
1064 auto_sbitmap
wont_exit (npeel
+ 1);
1066 && TREE_CODE (niter
) == INTEGER_CST
1067 && wi::leu_p (npeel
, wi::to_widest (niter
)))
1069 bitmap_ones (wont_exit
);
1070 bitmap_clear_bit (wont_exit
, 0);
1075 bitmap_clear (wont_exit
);
1077 if (!gimple_duplicate_loop_to_header_edge (loop
, loop_preheader_edge (loop
),
1079 exit
, &edges_to_remove
,
1080 DLTHE_FLAG_UPDATE_FREQ
))
1082 free_original_copy_tables ();
1085 free_original_copy_tables ();
1086 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
1088 fprintf (dump_file
, "Peeled loop %d, %i times.\n",
1089 loop
->num
, (int) npeel
);
1091 if (loop
->any_estimate
)
1093 if (wi::ltu_p (npeel
, loop
->nb_iterations_estimate
))
1094 loop
->nb_iterations_estimate
-= npeel
;
1096 loop
->nb_iterations_estimate
= 0;
1098 if (loop
->any_upper_bound
)
1100 if (wi::ltu_p (npeel
, loop
->nb_iterations_upper_bound
))
1101 loop
->nb_iterations_upper_bound
-= npeel
;
1103 loop
->nb_iterations_upper_bound
= 0;
1105 if (loop
->any_likely_upper_bound
)
1107 if (wi::ltu_p (npeel
, loop
->nb_iterations_likely_upper_bound
))
1108 loop
->nb_iterations_likely_upper_bound
-= npeel
;
1111 loop
->any_estimate
= true;
1112 loop
->nb_iterations_estimate
= 0;
1113 loop
->nb_iterations_likely_upper_bound
= 0;
1116 profile_count entry_count
= profile_count::zero ();
1120 FOR_EACH_EDGE (e
, ei
, loop
->header
->preds
)
1121 if (e
->src
!= loop
->latch
)
1123 if (e
->src
->count
.initialized_p ())
1124 entry_count
= e
->src
->count
+ e
->src
->count
;
1125 gcc_assert (!flow_bb_inside_loop_p (loop
, e
->src
));
1127 profile_probability p
= profile_probability::very_unlikely ();
1128 p
= entry_count
.probability_in (loop
->header
->count
);
1129 scale_loop_profile (loop
, p
, 0);
1130 bitmap_set_bit (peeled_loops
, loop
->num
);
1133 /* Adds a canonical induction variable to LOOP if suitable.
1134 CREATE_IV is true if we may create a new iv. UL determines
1135 which loops we are allowed to completely unroll. If TRY_EVAL is true, we try
1136 to determine the number of iterations of a loop by direct evaluation.
1137 Returns true if cfg is changed. */
1140 canonicalize_loop_induction_variables (struct loop
*loop
,
1141 bool create_iv
, enum unroll_level ul
,
1146 HOST_WIDE_INT maxiter
;
1147 bool modified
= false;
1148 location_t locus
= UNKNOWN_LOCATION
;
1150 niter
= number_of_latch_executions (loop
);
1151 exit
= single_exit (loop
);
1152 if (TREE_CODE (niter
) == INTEGER_CST
)
1153 locus
= gimple_location (last_stmt (exit
->src
));
1156 /* If the loop has more than one exit, try checking all of them
1157 for # of iterations determinable through scev. */
1159 niter
= find_loop_niter (loop
, &exit
);
1161 /* Finally if everything else fails, try brute force evaluation. */
1163 && (chrec_contains_undetermined (niter
)
1164 || TREE_CODE (niter
) != INTEGER_CST
))
1165 niter
= find_loop_niter_by_eval (loop
, &exit
);
1168 locus
= gimple_location (last_stmt (exit
->src
));
1170 if (TREE_CODE (niter
) != INTEGER_CST
)
1174 /* We work exceptionally hard here to estimate the bound
1175 by find_loop_niter_by_eval. Be sure to keep it for future. */
1176 if (niter
&& TREE_CODE (niter
) == INTEGER_CST
)
1178 record_niter_bound (loop
, wi::to_widest (niter
),
1179 exit
== single_likely_exit (loop
), true);
1182 /* Force re-computation of loop bounds so we can remove redundant exits. */
1183 maxiter
= max_loop_iterations_int (loop
);
1185 if (dump_file
&& (dump_flags
& TDF_DETAILS
)
1186 && TREE_CODE (niter
) == INTEGER_CST
)
1188 fprintf (dump_file
, "Loop %d iterates ", loop
->num
);
1189 print_generic_expr (dump_file
, niter
, TDF_SLIM
);
1190 fprintf (dump_file
, " times.\n");
1192 if (dump_file
&& (dump_flags
& TDF_DETAILS
)
1195 fprintf (dump_file
, "Loop %d iterates at most %i times.\n", loop
->num
,
1198 if (dump_file
&& (dump_flags
& TDF_DETAILS
)
1199 && likely_max_loop_iterations_int (loop
) >= 0)
1201 fprintf (dump_file
, "Loop %d likely iterates at most %i times.\n",
1202 loop
->num
, (int)likely_max_loop_iterations_int (loop
));
1205 /* Remove exits that are known to be never taken based on loop bound.
1206 Needs to be called after compilation of max_loop_iterations_int that
1207 populates the loop bounds. */
1208 modified
|= remove_redundant_iv_tests (loop
);
1210 if (try_unroll_loop_completely (loop
, exit
, niter
, ul
, maxiter
, locus
))
1214 && niter
&& !chrec_contains_undetermined (niter
)
1215 && exit
&& just_once_each_iteration_p (loop
, exit
->src
))
1216 create_canonical_iv (loop
, exit
, niter
);
1219 modified
|= try_peel_loop (loop
, exit
, niter
, maxiter
);
1224 /* The main entry point of the pass. Adds canonical induction variables
1225 to the suitable loops. */
1228 canonicalize_induction_variables (void)
1231 bool changed
= false;
1232 bool irred_invalidated
= false;
1233 bitmap loop_closed_ssa_invalidated
= BITMAP_ALLOC (NULL
);
1235 estimate_numbers_of_iterations (cfun
);
1237 FOR_EACH_LOOP (loop
, LI_FROM_INNERMOST
)
1239 changed
|= canonicalize_loop_induction_variables (loop
,
1240 true, UL_SINGLE_ITER
,
1243 gcc_assert (!need_ssa_update_p (cfun
));
1245 unloop_loops (loop_closed_ssa_invalidated
, &irred_invalidated
);
1246 if (irred_invalidated
1247 && loops_state_satisfies_p (LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS
))
1248 mark_irreducible_loops ();
1250 /* Clean up the information about numbers of iterations, since brute force
1251 evaluation could reveal new information. */
1252 free_numbers_of_iterations_estimates (cfun
);
1255 if (!bitmap_empty_p (loop_closed_ssa_invalidated
))
1257 gcc_checking_assert (loops_state_satisfies_p (LOOP_CLOSED_SSA
));
1258 rewrite_into_loop_closed_ssa (NULL
, TODO_update_ssa
);
1260 BITMAP_FREE (loop_closed_ssa_invalidated
);
1263 return TODO_cleanup_cfg
;
1267 /* Propagate constant SSA_NAMEs defined in basic block BB. */
1270 propagate_constants_for_unrolling (basic_block bb
)
1272 /* Look for degenerate PHI nodes with constant argument. */
1273 for (gphi_iterator gsi
= gsi_start_phis (bb
); !gsi_end_p (gsi
); )
1275 gphi
*phi
= gsi
.phi ();
1276 tree result
= gimple_phi_result (phi
);
1277 tree arg
= gimple_phi_arg_def (phi
, 0);
1279 if (! SSA_NAME_OCCURS_IN_ABNORMAL_PHI (result
)
1280 && gimple_phi_num_args (phi
) == 1
1281 && CONSTANT_CLASS_P (arg
))
1283 replace_uses_by (result
, arg
);
1284 gsi_remove (&gsi
, true);
1285 release_ssa_name (result
);
1291 /* Look for assignments to SSA names with constant RHS. */
1292 for (gimple_stmt_iterator gsi
= gsi_start_bb (bb
); !gsi_end_p (gsi
); )
1294 gimple
*stmt
= gsi_stmt (gsi
);
1297 if (is_gimple_assign (stmt
)
1298 && TREE_CODE_CLASS (gimple_assign_rhs_code (stmt
)) == tcc_constant
1299 && (lhs
= gimple_assign_lhs (stmt
), TREE_CODE (lhs
) == SSA_NAME
)
1300 && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs
))
1302 replace_uses_by (lhs
, gimple_assign_rhs1 (stmt
));
1303 gsi_remove (&gsi
, true);
1304 release_ssa_name (lhs
);
1311 /* Process loops from innermost to outer, stopping at the innermost
1312 loop we unrolled. */
1315 tree_unroll_loops_completely_1 (bool may_increase_size
, bool unroll_outer
,
1316 bitmap father_bbs
, struct loop
*loop
)
1318 struct loop
*loop_father
;
1319 bool changed
= false;
1321 enum unroll_level ul
;
1323 /* Process inner loops first. */
1324 for (inner
= loop
->inner
; inner
!= NULL
; inner
= inner
->next
)
1325 changed
|= tree_unroll_loops_completely_1 (may_increase_size
,
1326 unroll_outer
, father_bbs
,
1329 /* If we changed an inner loop we cannot process outer loops in this
1330 iteration because SSA form is not up-to-date. Continue with
1331 siblings of outer loops instead. */
1335 /* Don't unroll #pragma omp simd loops until the vectorizer
1336 attempts to vectorize those. */
1337 if (loop
->force_vectorize
)
1340 /* Try to unroll this loop. */
1341 loop_father
= loop_outer (loop
);
1345 if (loop
->unroll
> 1)
1347 else if (may_increase_size
&& optimize_loop_nest_for_speed_p (loop
)
1348 /* Unroll outermost loops only if asked to do so or they do
1349 not cause code growth. */
1350 && (unroll_outer
|| loop_outer (loop_father
)))
1355 if (canonicalize_loop_induction_variables
1356 (loop
, false, ul
, !flag_tree_loop_ivcanon
))
1358 /* If we'll continue unrolling, we need to propagate constants
1359 within the new basic blocks to fold away induction variable
1360 computations; otherwise, the size might blow up before the
1361 iteration is complete and the IR eventually cleaned up. */
1362 if (loop_outer (loop_father
))
1363 bitmap_set_bit (father_bbs
, loop_father
->header
->index
);
1371 /* Unroll LOOPS completely if they iterate just few times. Unless
1372 MAY_INCREASE_SIZE is true, perform the unrolling only if the
1373 size of the code does not increase. */
1376 tree_unroll_loops_completely (bool may_increase_size
, bool unroll_outer
)
1378 bitmap father_bbs
= BITMAP_ALLOC (NULL
);
1381 bool irred_invalidated
= false;
1383 estimate_numbers_of_iterations (cfun
);
1388 bitmap loop_closed_ssa_invalidated
= NULL
;
1390 if (loops_state_satisfies_p (LOOP_CLOSED_SSA
))
1391 loop_closed_ssa_invalidated
= BITMAP_ALLOC (NULL
);
1393 free_numbers_of_iterations_estimates (cfun
);
1394 estimate_numbers_of_iterations (cfun
);
1396 changed
= tree_unroll_loops_completely_1 (may_increase_size
,
1397 unroll_outer
, father_bbs
,
1398 current_loops
->tree_root
);
1403 unloop_loops (loop_closed_ssa_invalidated
, &irred_invalidated
);
1405 /* We can not use TODO_update_ssa_no_phi because VOPS gets confused. */
1406 if (loop_closed_ssa_invalidated
1407 && !bitmap_empty_p (loop_closed_ssa_invalidated
))
1408 rewrite_into_loop_closed_ssa (loop_closed_ssa_invalidated
,
1411 update_ssa (TODO_update_ssa
);
1413 /* father_bbs is a bitmap of loop father header BB indices.
1414 Translate that to what non-root loops these BBs belong to now. */
1416 bitmap fathers
= BITMAP_ALLOC (NULL
);
1417 EXECUTE_IF_SET_IN_BITMAP (father_bbs
, 0, i
, bi
)
1419 basic_block unrolled_loop_bb
= BASIC_BLOCK_FOR_FN (cfun
, i
);
1420 if (! unrolled_loop_bb
)
1422 if (loop_outer (unrolled_loop_bb
->loop_father
))
1423 bitmap_set_bit (fathers
,
1424 unrolled_loop_bb
->loop_father
->num
);
1426 bitmap_clear (father_bbs
);
1427 /* Propagate the constants within the new basic blocks. */
1428 EXECUTE_IF_SET_IN_BITMAP (fathers
, 0, i
, bi
)
1430 loop_p father
= get_loop (cfun
, i
);
1431 basic_block
*body
= get_loop_body_in_dom_order (father
);
1432 for (unsigned j
= 0; j
< father
->num_nodes
; j
++)
1433 propagate_constants_for_unrolling (body
[j
]);
1436 BITMAP_FREE (fathers
);
1438 /* This will take care of removing completely unrolled loops
1439 from the loop structures so we can continue unrolling now
1441 if (cleanup_tree_cfg ())
1442 update_ssa (TODO_update_ssa_only_virtuals
);
1444 /* Clean up the information about numbers of iterations, since
1445 complete unrolling might have invalidated it. */
1447 if (flag_checking
&& loops_state_satisfies_p (LOOP_CLOSED_SSA
))
1448 verify_loop_closed_ssa (true);
1450 if (loop_closed_ssa_invalidated
)
1451 BITMAP_FREE (loop_closed_ssa_invalidated
);
1454 && ++iteration
<= PARAM_VALUE (PARAM_MAX_UNROLL_ITERATIONS
));
1456 BITMAP_FREE (father_bbs
);
1458 if (irred_invalidated
1459 && loops_state_satisfies_p (LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS
))
1460 mark_irreducible_loops ();
1465 /* Canonical induction variable creation pass. */
1469 const pass_data pass_data_iv_canon
=
1471 GIMPLE_PASS
, /* type */
1472 "ivcanon", /* name */
1473 OPTGROUP_LOOP
, /* optinfo_flags */
1474 TV_TREE_LOOP_IVCANON
, /* tv_id */
1475 ( PROP_cfg
| PROP_ssa
), /* properties_required */
1476 0, /* properties_provided */
1477 0, /* properties_destroyed */
1478 0, /* todo_flags_start */
1479 0, /* todo_flags_finish */
1482 class pass_iv_canon
: public gimple_opt_pass
1485 pass_iv_canon (gcc::context
*ctxt
)
1486 : gimple_opt_pass (pass_data_iv_canon
, ctxt
)
1489 /* opt_pass methods: */
1490 virtual bool gate (function
*) { return flag_tree_loop_ivcanon
!= 0; }
1491 virtual unsigned int execute (function
*fun
);
1493 }; // class pass_iv_canon
1496 pass_iv_canon::execute (function
*fun
)
1498 if (number_of_loops (fun
) <= 1)
1501 return canonicalize_induction_variables ();
1507 make_pass_iv_canon (gcc::context
*ctxt
)
1509 return new pass_iv_canon (ctxt
);
1512 /* Complete unrolling of loops. */
1516 const pass_data pass_data_complete_unroll
=
1518 GIMPLE_PASS
, /* type */
1519 "cunroll", /* name */
1520 OPTGROUP_LOOP
, /* optinfo_flags */
1521 TV_COMPLETE_UNROLL
, /* tv_id */
1522 ( PROP_cfg
| PROP_ssa
), /* properties_required */
1523 0, /* properties_provided */
1524 0, /* properties_destroyed */
1525 0, /* todo_flags_start */
1526 0, /* todo_flags_finish */
1529 class pass_complete_unroll
: public gimple_opt_pass
1532 pass_complete_unroll (gcc::context
*ctxt
)
1533 : gimple_opt_pass (pass_data_complete_unroll
, ctxt
)
1536 /* opt_pass methods: */
1537 virtual unsigned int execute (function
*);
1539 }; // class pass_complete_unroll
1542 pass_complete_unroll::execute (function
*fun
)
1544 if (number_of_loops (fun
) <= 1)
1547 /* If we ever decide to run loop peeling more than once, we will need to
1548 track loops already peeled in loop structures themselves to avoid
1549 re-peeling the same loop multiple times. */
1550 if (flag_peel_loops
)
1551 peeled_loops
= BITMAP_ALLOC (NULL
);
1552 unsigned int val
= tree_unroll_loops_completely (flag_unroll_loops
1554 || optimize
>= 3, true);
1557 BITMAP_FREE (peeled_loops
);
1558 peeled_loops
= NULL
;
1566 make_pass_complete_unroll (gcc::context
*ctxt
)
1568 return new pass_complete_unroll (ctxt
);
1571 /* Complete unrolling of inner loops. */
1575 const pass_data pass_data_complete_unrolli
=
1577 GIMPLE_PASS
, /* type */
1578 "cunrolli", /* name */
1579 OPTGROUP_LOOP
, /* optinfo_flags */
1580 TV_COMPLETE_UNROLL
, /* tv_id */
1581 ( PROP_cfg
| PROP_ssa
), /* properties_required */
1582 0, /* properties_provided */
1583 0, /* properties_destroyed */
1584 0, /* todo_flags_start */
1585 0, /* todo_flags_finish */
1588 class pass_complete_unrolli
: public gimple_opt_pass
1591 pass_complete_unrolli (gcc::context
*ctxt
)
1592 : gimple_opt_pass (pass_data_complete_unrolli
, ctxt
)
1595 /* opt_pass methods: */
1596 virtual bool gate (function
*) { return optimize
>= 2; }
1597 virtual unsigned int execute (function
*);
1599 }; // class pass_complete_unrolli
1602 pass_complete_unrolli::execute (function
*fun
)
1606 loop_optimizer_init (LOOPS_NORMAL
| LOOPS_HAVE_RECORDED_EXITS
);
1607 if (number_of_loops (fun
) > 1)
1610 ret
= tree_unroll_loops_completely (optimize
>= 3, false);
1613 loop_optimizer_finalize ();
1621 make_pass_complete_unrolli (gcc::context
*ctxt
)
1623 return new pass_complete_unrolli (ctxt
);