1 /* Code sinking for trees
2 Copyright (C) 2001-2022 Free Software Foundation, Inc.
3 Contributed by Daniel Berlin <dan@dberlin.org>
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3, or (at your option)
12 GCC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
23 #include "coretypes.h"
28 #include "tree-pass.h"
30 #include "gimple-pretty-print.h"
31 #include "fold-const.h"
32 #include "stor-layout.h"
34 #include "gimple-iterator.h"
40 1. Sinking store only using scalar promotion (IE without moving the RHS):
60 Store copy propagation will take care of the store elimination above.
63 2. Sinking using Partial Dead Code Elimination. */
68 /* The number of statements sunk down the flowgraph by code sinking. */
71 /* The number of stores commoned and sunk down by store commoning. */
76 /* Given a PHI, and one of its arguments (DEF), find the edge for
77 that argument and return it. If the argument occurs twice in the PHI node,
81 find_bb_for_arg (gphi
*phi
, tree def
)
84 bool foundone
= false;
85 basic_block result
= NULL
;
86 for (i
= 0; i
< gimple_phi_num_args (phi
); i
++)
87 if (PHI_ARG_DEF (phi
, i
) == def
)
92 result
= gimple_phi_arg_edge (phi
, i
)->src
;
97 /* When the first immediate use is in a statement, then return true if all
98 immediate uses in IMM are in the same statement.
99 We could also do the case where the first immediate use is in a phi node,
100 and all the other uses are in phis in the same basic block, but this
101 requires some expensive checking later (you have to make sure no def/vdef
102 in the statement occurs for multiple edges in the various phi nodes it's
103 used in, so that you only have one place you can sink it to. */
106 all_immediate_uses_same_place (def_operand_p def_p
)
108 tree var
= DEF_FROM_PTR (def_p
);
109 imm_use_iterator imm_iter
;
112 gimple
*firstuse
= NULL
;
113 FOR_EACH_IMM_USE_FAST (use_p
, imm_iter
, var
)
115 if (is_gimple_debug (USE_STMT (use_p
)))
117 if (firstuse
== NULL
)
118 firstuse
= USE_STMT (use_p
);
120 if (firstuse
!= USE_STMT (use_p
))
127 /* Find the nearest common dominator of all of the immediate uses in IMM. */
130 nearest_common_dominator_of_uses (def_operand_p def_p
, bool *debug_stmts
)
132 tree var
= DEF_FROM_PTR (def_p
);
134 basic_block commondom
;
137 imm_use_iterator imm_iter
;
140 FOR_EACH_IMM_USE_FAST (use_p
, imm_iter
, var
)
142 gimple
*usestmt
= USE_STMT (use_p
);
143 basic_block useblock
;
145 if (gphi
*phi
= dyn_cast
<gphi
*> (usestmt
))
147 int idx
= PHI_ARG_INDEX_FROM_USE (use_p
);
149 useblock
= gimple_phi_arg_edge (phi
, idx
)->src
;
151 else if (is_gimple_debug (usestmt
))
158 useblock
= gimple_bb (usestmt
);
161 /* Short circuit. Nothing dominates the entry block. */
162 if (useblock
== ENTRY_BLOCK_PTR_FOR_FN (cfun
))
165 bitmap_set_bit (blocks
, useblock
->index
);
167 commondom
= BASIC_BLOCK_FOR_FN (cfun
, bitmap_first_set_bit (blocks
));
168 EXECUTE_IF_SET_IN_BITMAP (blocks
, 0, j
, bi
)
169 commondom
= nearest_common_dominator (CDI_DOMINATORS
, commondom
,
170 BASIC_BLOCK_FOR_FN (cfun
, j
));
174 /* Given EARLY_BB and LATE_BB, two blocks in a path through the dominator
175 tree, return the best basic block between them (inclusive) to place
178 We want the most control dependent block in the shallowest loop nest.
180 If the resulting block is in a shallower loop nest, then use it. Else
181 only use the resulting block if it has significantly lower execution
182 frequency than EARLY_BB to avoid gratuitous statement movement. We
183 consider statements with VOPS more desirable to move.
185 This pass would obviously benefit from PDO as it utilizes block
186 frequencies. It would also benefit from recomputing frequencies
187 if profile data is not available since frequencies often get out
188 of sync with reality. */
191 select_best_block (basic_block early_bb
,
195 basic_block best_bb
= late_bb
;
196 basic_block temp_bb
= late_bb
;
199 while (temp_bb
!= early_bb
)
201 /* If we've moved into a lower loop nest, then that becomes
203 if (bb_loop_depth (temp_bb
) < bb_loop_depth (best_bb
))
206 /* Walk up the dominator tree, hopefully we'll find a shallower
208 temp_bb
= get_immediate_dominator (CDI_DOMINATORS
, temp_bb
);
211 /* If we found a shallower loop nest, then we always consider that
212 a win. This will always give us the most control dependent block
213 within that loop nest. */
214 if (bb_loop_depth (best_bb
) < bb_loop_depth (early_bb
))
217 /* Get the sinking threshold. If the statement to be moved has memory
218 operands, then increase the threshold by 7% as those are even more
219 profitable to avoid, clamping at 100%. */
220 threshold
= param_sink_frequency_threshold
;
221 if (gimple_vuse (stmt
) || gimple_vdef (stmt
))
228 /* If BEST_BB is at the same nesting level, then require it to have
229 significantly lower execution frequency to avoid gratuitous movement. */
230 if (bb_loop_depth (best_bb
) == bb_loop_depth (early_bb
)
231 /* If result of comparsion is unknown, prefer EARLY_BB.
232 Thus use !(...>=..) rather than (...<...) */
233 && !(best_bb
->count
.apply_scale (100, 1)
234 >= early_bb
->count
.apply_scale (threshold
, 1)))
237 /* No better block found, so return EARLY_BB, which happens to be the
238 statement's original block. */
242 /* Given a statement (STMT) and the basic block it is currently in (FROMBB),
243 determine the location to sink the statement to, if any.
244 Returns true if there is such location; in that case, TOGSI points to the
245 statement before that STMT should be moved. */
248 statement_sink_location (gimple
*stmt
, basic_block frombb
,
249 gimple_stmt_iterator
*togsi
, bool *zero_uses_p
)
252 use_operand_p one_use
= NULL_USE_OPERAND_P
;
257 imm_use_iterator imm_iter
;
259 *zero_uses_p
= false;
261 /* We only can sink assignments and non-looping const/pure calls. */
263 if (!is_gimple_assign (stmt
)
264 && (!is_gimple_call (stmt
)
265 || !((cf
= gimple_call_flags (stmt
)) & (ECF_CONST
|ECF_PURE
))
266 || (cf
& ECF_LOOPING_CONST_OR_PURE
)))
269 /* We only can sink stmts with a single definition. */
270 def_p
= single_ssa_def_operand (stmt
, SSA_OP_ALL_DEFS
);
271 if (def_p
== NULL_DEF_OPERAND_P
)
274 /* There are a few classes of things we can't or don't move, some because we
275 don't have code to handle it, some because it's not profitable and some
276 because it's not legal.
278 We can't sink things that may be global stores, at least not without
279 calculating a lot more information, because we may cause it to no longer
280 be seen by an external routine that needs it depending on where it gets
283 We can't sink statements that end basic blocks without splitting the
284 incoming edge for the sink location to place it there.
286 We can't sink statements that have volatile operands.
288 We don't want to sink dead code, so anything with 0 immediate uses is not
291 Don't sink BLKmode assignments if current function has any local explicit
292 register variables, as BLKmode assignments may involve memcpy or memset
293 calls or, on some targets, inline expansion thereof that sometimes need
294 to use specific hard registers.
297 if (stmt_ends_bb_p (stmt
)
298 || gimple_has_side_effects (stmt
)
299 || (cfun
->has_local_explicit_reg_vars
300 && TYPE_MODE (TREE_TYPE (gimple_get_lhs (stmt
))) == BLKmode
))
303 /* Return if there are no immediate uses of this stmt. */
304 if (has_zero_uses (DEF_FROM_PTR (def_p
)))
310 if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (DEF_FROM_PTR (def_p
)))
313 FOR_EACH_SSA_USE_OPERAND (use_p
, stmt
, iter
, SSA_OP_ALL_USES
)
315 tree use
= USE_FROM_PTR (use_p
);
316 if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (use
))
322 /* If stmt is a store the one and only use needs to be the VOP
324 if (virtual_operand_p (DEF_FROM_PTR (def_p
)))
326 FOR_EACH_IMM_USE_FAST (use_p
, imm_iter
, DEF_FROM_PTR (def_p
))
328 gimple
*use_stmt
= USE_STMT (use_p
);
330 /* A killing definition is not a use. */
331 if ((gimple_has_lhs (use_stmt
)
332 && operand_equal_p (gimple_get_lhs (stmt
),
333 gimple_get_lhs (use_stmt
), 0))
334 || stmt_kills_ref_p (use_stmt
, gimple_get_lhs (stmt
)))
336 /* If use_stmt is or might be a nop assignment then USE_STMT
337 acts as a use as well as definition. */
339 && ref_maybe_used_by_stmt_p (use_stmt
,
340 gimple_get_lhs (stmt
)))
345 if (gimple_code (use_stmt
) != GIMPLE_PHI
)
357 /* If all the immediate uses are not in the same place, find the nearest
358 common dominator of all the immediate uses. For PHI nodes, we have to
359 find the nearest common dominator of all of the predecessor blocks, since
360 that is where insertion would have to take place. */
361 else if (gimple_vuse (stmt
)
362 || !all_immediate_uses_same_place (def_p
))
364 bool debug_stmts
= false;
365 basic_block commondom
= nearest_common_dominator_of_uses (def_p
,
368 if (commondom
== frombb
)
371 /* If this is a load then do not sink past any stores.
372 Look for virtual definitions in the path from frombb to the sink
373 location computed from the real uses and if found, adjust
374 that it a common dominator. */
375 if (gimple_vuse (stmt
))
377 /* Do not sink loads from hard registers. */
378 if (gimple_assign_single_p (stmt
)
379 && TREE_CODE (gimple_assign_rhs1 (stmt
)) == VAR_DECL
380 && DECL_HARD_REGISTER (gimple_assign_rhs1 (stmt
)))
383 imm_use_iterator imm_iter
;
385 FOR_EACH_IMM_USE_FAST (use_p
, imm_iter
, gimple_vuse (stmt
))
387 gimple
*use_stmt
= USE_STMT (use_p
);
388 basic_block bb
= gimple_bb (use_stmt
);
389 /* For PHI nodes the block we know sth about is the incoming block
391 if (gimple_code (use_stmt
) == GIMPLE_PHI
)
393 /* If the PHI defines the virtual operand, ignore it. */
394 if (gimple_phi_result (use_stmt
) == gimple_vuse (stmt
))
396 /* In case the PHI node post-dominates the current insert
397 location we can disregard it. But make sure it is not
398 dominating it as well as can happen in a CFG cycle. */
400 && !dominated_by_p (CDI_DOMINATORS
, commondom
, bb
)
401 && dominated_by_p (CDI_POST_DOMINATORS
, commondom
, bb
)
402 /* If the blocks are possibly within the same irreducible
403 cycle the above check breaks down. */
404 && !((bb
->flags
& commondom
->flags
& BB_IRREDUCIBLE_LOOP
)
405 && bb
->loop_father
== commondom
->loop_father
)
406 && !((commondom
->flags
& BB_IRREDUCIBLE_LOOP
)
407 && flow_loop_nested_p (commondom
->loop_father
,
409 && !((bb
->flags
& BB_IRREDUCIBLE_LOOP
)
410 && flow_loop_nested_p (bb
->loop_father
,
411 commondom
->loop_father
)))
413 bb
= EDGE_PRED (bb
, PHI_ARG_INDEX_FROM_USE (use_p
))->src
;
415 else if (!gimple_vdef (use_stmt
))
417 /* If the use is not dominated by the path entry it is not on
419 if (!dominated_by_p (CDI_DOMINATORS
, bb
, frombb
))
421 /* There is no easy way to disregard defs not on the path from
422 frombb to commondom so just consider them all. */
423 commondom
= nearest_common_dominator (CDI_DOMINATORS
,
425 if (commondom
== frombb
)
430 /* Our common dominator has to be dominated by frombb in order to be a
431 trivially safe place to put this statement, since it has multiple
433 if (!dominated_by_p (CDI_DOMINATORS
, commondom
, frombb
))
436 commondom
= select_best_block (frombb
, commondom
, stmt
);
438 if (commondom
== frombb
)
441 *togsi
= gsi_after_labels (commondom
);
447 FOR_EACH_IMM_USE_FAST (one_use
, imm_iter
, DEF_FROM_PTR (def_p
))
449 if (is_gimple_debug (USE_STMT (one_use
)))
453 use
= USE_STMT (one_use
);
455 if (gimple_code (use
) != GIMPLE_PHI
)
457 sinkbb
= select_best_block (frombb
, gimple_bb (use
), stmt
);
459 if (sinkbb
== frombb
)
462 if (sinkbb
== gimple_bb (use
))
463 *togsi
= gsi_for_stmt (use
);
465 *togsi
= gsi_after_labels (sinkbb
);
471 sinkbb
= find_bb_for_arg (as_a
<gphi
*> (use
), DEF_FROM_PTR (def_p
));
473 /* This can happen if there are multiple uses in a PHI. */
477 sinkbb
= select_best_block (frombb
, sinkbb
, stmt
);
478 if (!sinkbb
|| sinkbb
== frombb
)
481 /* If the latch block is empty, don't make it non-empty by sinking
482 something into it. */
483 if (sinkbb
== frombb
->loop_father
->latch
484 && empty_block_p (sinkbb
))
487 *togsi
= gsi_after_labels (sinkbb
);
492 /* Very simplistic code to sink common stores from the predecessor through
493 our virtual PHI. We do this before sinking stmts from BB as it might
494 expose sinking opportunities of the merged stores.
495 Once we have partial dead code elimination through sth like SSU-PRE this
496 should be moved there. */
499 sink_common_stores_to_bb (basic_block bb
)
504 if (EDGE_COUNT (bb
->preds
) > 1
505 && (phi
= get_virtual_phi (bb
)))
507 /* Repeat until no more common stores are found. */
510 gimple
*first_store
= NULL
;
511 auto_vec
<tree
, 5> vdefs
;
512 gimple_stmt_iterator gsi
;
514 /* Search for common stores defined by all virtual PHI args.
515 ??? Common stores not present in all predecessors could
516 be handled by inserting a forwarder to sink to. Generally
517 this involves deciding which stores to do this for if
518 multiple common stores are present for different sets of
519 predecessors. See PR11832 for an interesting case. */
520 for (unsigned i
= 0; i
< gimple_phi_num_args (phi
); ++i
)
522 tree arg
= gimple_phi_arg_def (phi
, i
);
523 gimple
*def
= SSA_NAME_DEF_STMT (arg
);
524 if (! is_gimple_assign (def
)
525 || stmt_can_throw_internal (cfun
, def
)
526 || (gimple_phi_arg_edge (phi
, i
)->flags
& EDGE_ABNORMAL
))
528 /* ??? We could handle some cascading with the def being
529 another PHI. We'd have to insert multiple PHIs for
530 the rhs then though (if they are not all equal). */
534 /* ??? Do not try to do anything fancy with aliasing, thus
535 do not sink across non-aliased loads (or even stores,
536 so different store order will make the sinking fail). */
537 bool all_uses_on_phi
= true;
538 imm_use_iterator iter
;
540 FOR_EACH_IMM_USE_FAST (use_p
, iter
, arg
)
541 if (USE_STMT (use_p
) != phi
)
543 all_uses_on_phi
= false;
546 if (! all_uses_on_phi
)
551 /* Check all stores are to the same LHS. */
554 /* ??? We could handle differing SSA uses in the LHS by inserting
556 else if (! operand_equal_p (gimple_assign_lhs (first_store
),
557 gimple_assign_lhs (def
), 0)
558 || (gimple_clobber_p (first_store
)
559 != gimple_clobber_p (def
)))
564 vdefs
.safe_push (arg
);
569 /* Check if we need a PHI node to merge the stored values. */
571 if (!gimple_clobber_p (first_store
))
572 for (unsigned i
= 1; i
< vdefs
.length (); ++i
)
574 gimple
*def
= SSA_NAME_DEF_STMT (vdefs
[i
]);
575 if (! operand_equal_p (gimple_assign_rhs1 (first_store
),
576 gimple_assign_rhs1 (def
), 0))
583 /* We cannot handle aggregate values if we need to merge them. */
584 tree type
= TREE_TYPE (gimple_assign_lhs (first_store
));
586 && ! is_gimple_reg_type (type
))
589 if (dump_enabled_p ())
591 dump_printf_loc (MSG_OPTIMIZED_LOCATIONS
,
593 "sinking common stores %sto ",
594 allsame
? "with same value " : "");
595 dump_generic_expr (MSG_OPTIMIZED_LOCATIONS
, TDF_SLIM
,
596 gimple_assign_lhs (first_store
));
597 dump_printf (MSG_OPTIMIZED_LOCATIONS
, "\n");
600 /* Insert a PHI to merge differing stored values if necessary.
601 Note that in general inserting PHIs isn't a very good idea as
602 it makes the job of coalescing and register allocation harder.
603 Even common SSA uses on the rhs/lhs might extend their lifetime
604 across multiple edges by this code motion which makes
605 register allocation harder. */
609 from
= make_ssa_name (type
);
610 gphi
*newphi
= create_phi_node (from
, bb
);
611 for (unsigned i
= 0; i
< vdefs
.length (); ++i
)
613 gimple
*def
= SSA_NAME_DEF_STMT (vdefs
[i
]);
614 add_phi_arg (newphi
, gimple_assign_rhs1 (def
),
615 EDGE_PRED (bb
, i
), UNKNOWN_LOCATION
);
619 from
= gimple_assign_rhs1 (first_store
);
621 /* Remove all stores. */
622 for (unsigned i
= 0; i
< vdefs
.length (); ++i
)
623 TREE_VISITED (vdefs
[i
]) = 1;
624 for (unsigned i
= 0; i
< vdefs
.length (); ++i
)
625 /* If we have more than one use of a VDEF on the PHI make sure
626 we remove the defining stmt only once. */
627 if (TREE_VISITED (vdefs
[i
]))
629 TREE_VISITED (vdefs
[i
]) = 0;
630 gimple
*def
= SSA_NAME_DEF_STMT (vdefs
[i
]);
631 gsi
= gsi_for_stmt (def
);
632 unlink_stmt_vdef (def
);
633 gsi_remove (&gsi
, true);
637 /* Insert the first store at the beginning of the merge BB. */
638 gimple_set_vdef (first_store
, gimple_phi_result (phi
));
639 SSA_NAME_DEF_STMT (gimple_vdef (first_store
)) = first_store
;
640 gimple_phi_set_result (phi
, make_ssa_name (gimple_vop (cfun
)));
641 gimple_set_vuse (first_store
, gimple_phi_result (phi
));
642 gimple_assign_set_rhs1 (first_store
, from
);
643 /* ??? Should we reset first_stores location? */
644 gsi
= gsi_after_labels (bb
);
645 gsi_insert_before (&gsi
, first_store
, GSI_SAME_STMT
);
646 sink_stats
.commoned
++;
648 todo
|= TODO_cleanup_cfg
;
651 /* We could now have empty predecessors that we could remove,
652 forming a proper CFG for further sinking. Note that even
653 CFG cleanup doesn't do this fully at the moment and it
654 doesn't preserve post-dominators in the process either.
655 The mergephi pass might do it though. gcc.dg/tree-ssa/ssa-sink-13.c
656 shows this nicely if you disable tail merging or (same effect)
657 make the stored values unequal. */
663 /* Perform code sinking on BB */
666 sink_code_in_bb (basic_block bb
)
669 gimple_stmt_iterator gsi
;
675 /* Sink common stores from the predecessor through our virtual PHI. */
676 todo
|= sink_common_stores_to_bb (bb
);
678 /* If this block doesn't dominate anything, there can't be any place to sink
679 the statements to. */
680 if (first_dom_son (CDI_DOMINATORS
, bb
) == NULL
)
683 /* We can't move things across abnormal edges, so don't try. */
684 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
685 if (e
->flags
& EDGE_ABNORMAL
)
688 for (gsi
= gsi_last_bb (bb
); !gsi_end_p (gsi
);)
690 gimple
*stmt
= gsi_stmt (gsi
);
691 gimple_stmt_iterator togsi
;
694 if (!statement_sink_location (stmt
, bb
, &togsi
, &zero_uses_p
))
696 gimple_stmt_iterator saved
= gsi
;
697 if (!gsi_end_p (gsi
))
699 /* If we face a dead stmt remove it as it possibly blocks
702 && !gimple_vdef (stmt
)
703 && (cfun
->can_delete_dead_exceptions
704 || !stmt_could_throw_p (cfun
, stmt
)))
706 gsi_remove (&saved
, true);
715 fprintf (dump_file
, "Sinking ");
716 print_gimple_stmt (dump_file
, stmt
, 0, TDF_VOPS
);
717 fprintf (dump_file
, " from bb %d to bb %d\n",
718 bb
->index
, (gsi_bb (togsi
))->index
);
721 /* Update virtual operands of statements in the path we
723 if (gimple_vdef (stmt
))
725 imm_use_iterator iter
;
729 FOR_EACH_IMM_USE_STMT (vuse_stmt
, iter
, gimple_vdef (stmt
))
730 if (gimple_code (vuse_stmt
) != GIMPLE_PHI
)
731 FOR_EACH_IMM_USE_ON_STMT (use_p
, iter
)
732 SET_USE (use_p
, gimple_vuse (stmt
));
735 /* If this is the end of the basic block, we need to insert at the end
736 of the basic block. */
737 if (gsi_end_p (togsi
))
738 gsi_move_to_bb_end (&gsi
, gsi_bb (togsi
));
740 gsi_move_before (&gsi
, &togsi
);
744 /* If we've just removed the last statement of the BB, the
745 gsi_end_p() test below would fail, but gsi_prev() would have
746 succeeded, and we want it to succeed. So we keep track of
747 whether we're at the last statement and pick up the new last
751 gsi
= gsi_last_bb (bb
);
756 if (!gsi_end_p (gsi
))
761 for (son
= first_dom_son (CDI_POST_DOMINATORS
, bb
);
763 son
= next_dom_son (CDI_POST_DOMINATORS
, son
))
765 todo
|= sink_code_in_bb (son
);
771 /* Perform code sinking.
772 This moves code down the flowgraph when we know it would be
773 profitable to do so, or it wouldn't increase the number of
774 executions of the statement.
787 a_6 = PHI (a_5, a_1);
790 we'll transform this into:
801 a_6 = PHI (a_5, a_1);
804 Note that this reduces the number of computations of a = b + c to 1
805 when we take the else edge, instead of 2.
809 const pass_data pass_data_sink_code
=
811 GIMPLE_PASS
, /* type */
813 OPTGROUP_NONE
, /* optinfo_flags */
814 TV_TREE_SINK
, /* tv_id */
815 /* PROP_no_crit_edges is ensured by running split_edges_for_insertion in
816 pass_data_sink_code::execute (). */
817 ( PROP_cfg
| PROP_ssa
), /* properties_required */
818 0, /* properties_provided */
819 0, /* properties_destroyed */
820 0, /* todo_flags_start */
821 TODO_update_ssa
, /* todo_flags_finish */
824 class pass_sink_code
: public gimple_opt_pass
827 pass_sink_code (gcc::context
*ctxt
)
828 : gimple_opt_pass (pass_data_sink_code
, ctxt
), unsplit_edges (false)
831 /* opt_pass methods: */
832 virtual bool gate (function
*) { return flag_tree_sink
!= 0; }
833 virtual unsigned int execute (function
*);
834 opt_pass
*clone (void) { return new pass_sink_code (m_ctxt
); }
835 void set_pass_param (unsigned n
, bool param
)
838 unsplit_edges
= param
;
843 }; // class pass_sink_code
846 pass_sink_code::execute (function
*fun
)
848 loop_optimizer_init (LOOPS_NORMAL
);
849 split_edges_for_insertion ();
850 /* Arrange for the critical edge splitting to be undone if requested. */
851 unsigned todo
= unsplit_edges
? TODO_cleanup_cfg
: 0;
852 connect_infinite_loops_to_exit ();
853 memset (&sink_stats
, 0, sizeof (sink_stats
));
854 calculate_dominance_info (CDI_DOMINATORS
);
855 calculate_dominance_info (CDI_POST_DOMINATORS
);
856 todo
|= sink_code_in_bb (EXIT_BLOCK_PTR_FOR_FN (fun
));
857 statistics_counter_event (fun
, "Sunk statements", sink_stats
.sunk
);
858 statistics_counter_event (fun
, "Commoned stores", sink_stats
.commoned
);
859 free_dominance_info (CDI_POST_DOMINATORS
);
860 remove_fake_exit_edges ();
861 loop_optimizer_finalize ();
869 make_pass_sink_code (gcc::context
*ctxt
)
871 return new pass_sink_code (ctxt
);