1 /* Optimization of PHI nodes by converting them into straightline code.
2 Copyright (C) 2004-2021 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/>. */
22 #include "coretypes.h"
24 #include "insn-codes.h"
29 #include "tree-pass.h"
32 #include "optabs-tree.h"
33 #include "insn-config.h"
34 #include "gimple-pretty-print.h"
35 #include "fold-const.h"
36 #include "stor-layout.h"
39 #include "gimple-iterator.h"
40 #include "gimplify-me.h"
45 #include "tree-data-ref.h"
46 #include "tree-scalar-evolution.h"
47 #include "tree-inline.h"
48 #include "case-cfn-macros.h"
50 #include "gimple-fold.h"
51 #include "internal-fn.h"
52 #include "gimple-range.h"
53 #include "gimple-match.h"
55 static unsigned int tree_ssa_phiopt_worker (bool, bool, bool);
56 static bool two_value_replacement (basic_block
, basic_block
, edge
, gphi
*,
58 static bool match_simplify_replacement (basic_block
, basic_block
,
59 edge
, edge
, gphi
*, tree
, tree
, bool);
60 static gphi
*factor_out_conditional_conversion (edge
, edge
, gphi
*, tree
, tree
,
62 static int value_replacement (basic_block
, basic_block
,
63 edge
, edge
, gphi
*, tree
, tree
);
64 static bool minmax_replacement (basic_block
, basic_block
,
65 edge
, edge
, gphi
*, tree
, tree
);
66 static bool abs_replacement (basic_block
, basic_block
,
67 edge
, edge
, gphi
*, tree
, tree
);
68 static bool spaceship_replacement (basic_block
, basic_block
,
69 edge
, edge
, gphi
*, tree
, tree
);
70 static bool cond_removal_in_popcount_clz_ctz_pattern (basic_block
, basic_block
,
73 static bool cond_store_replacement (basic_block
, basic_block
, edge
, edge
,
75 static bool cond_if_else_store_replacement (basic_block
, basic_block
, basic_block
);
76 static hash_set
<tree
> * get_non_trapping ();
77 static void replace_phi_edge_with_variable (basic_block
, edge
, gphi
*, tree
);
78 static void hoist_adjacent_loads (basic_block
, basic_block
,
79 basic_block
, basic_block
);
80 static bool gate_hoist_loads (void);
82 /* This pass tries to transform conditional stores into unconditional
83 ones, enabling further simplifications with the simpler then and else
84 blocks. In particular it replaces this:
87 if (cond) goto bb2; else goto bb1;
95 if (cond) goto bb1; else goto bb2;
99 condtmp = PHI <RHS, condtmp'>
102 This transformation can only be done under several constraints,
103 documented below. It also replaces:
106 if (cond) goto bb2; else goto bb1;
117 if (cond) goto bb3; else goto bb1;
120 condtmp = PHI <RHS1, RHS2>
124 tree_ssa_cs_elim (void)
127 /* ??? We are not interested in loop related info, but the following
128 will create it, ICEing as we didn't init loops with pre-headers.
129 An interfacing issue of find_data_references_in_bb. */
130 loop_optimizer_init (LOOPS_NORMAL
);
132 todo
= tree_ssa_phiopt_worker (true, false, false);
134 loop_optimizer_finalize ();
138 /* Return the singleton PHI in the SEQ of PHIs for edges E0 and E1. */
141 single_non_singleton_phi_for_edges (gimple_seq seq
, edge e0
, edge e1
)
143 gimple_stmt_iterator i
;
145 if (gimple_seq_singleton_p (seq
))
146 return as_a
<gphi
*> (gsi_stmt (gsi_start (seq
)));
147 for (i
= gsi_start (seq
); !gsi_end_p (i
); gsi_next (&i
))
149 gphi
*p
= as_a
<gphi
*> (gsi_stmt (i
));
150 /* If the PHI arguments are equal then we can skip this PHI. */
151 if (operand_equal_for_phi_arg_p (gimple_phi_arg_def (p
, e0
->dest_idx
),
152 gimple_phi_arg_def (p
, e1
->dest_idx
)))
155 /* If we already have a PHI that has the two edge arguments are
156 different, then return it is not a singleton for these PHIs. */
165 /* The core routine of conditional store replacement and normal
166 phi optimizations. Both share much of the infrastructure in how
167 to match applicable basic block patterns. DO_STORE_ELIM is true
168 when we want to do conditional store replacement, false otherwise.
169 DO_HOIST_LOADS is true when we want to hoist adjacent loads out
170 of diamond control flow patterns, false otherwise. */
172 tree_ssa_phiopt_worker (bool do_store_elim
, bool do_hoist_loads
, bool early_p
)
175 basic_block
*bb_order
;
177 bool cfgchanged
= false;
178 hash_set
<tree
> *nontrap
= 0;
180 calculate_dominance_info (CDI_DOMINATORS
);
183 /* Calculate the set of non-trapping memory accesses. */
184 nontrap
= get_non_trapping ();
186 /* Search every basic block for COND_EXPR we may be able to optimize.
188 We walk the blocks in order that guarantees that a block with
189 a single predecessor is processed before the predecessor.
190 This ensures that we collapse inner ifs before visiting the
191 outer ones, and also that we do not try to visit a removed
193 bb_order
= single_pred_before_succ_order ();
194 n
= n_basic_blocks_for_fn (cfun
) - NUM_FIXED_BLOCKS
;
196 for (i
= 0; i
< n
; i
++)
200 basic_block bb1
, bb2
;
206 cond_stmt
= last_stmt (bb
);
207 /* Check to see if the last statement is a GIMPLE_COND. */
209 || gimple_code (cond_stmt
) != GIMPLE_COND
)
212 e1
= EDGE_SUCC (bb
, 0);
214 e2
= EDGE_SUCC (bb
, 1);
217 /* We cannot do the optimization on abnormal edges. */
218 if ((e1
->flags
& EDGE_ABNORMAL
) != 0
219 || (e2
->flags
& EDGE_ABNORMAL
) != 0)
222 /* If either bb1's succ or bb2 or bb2's succ is non NULL. */
223 if (EDGE_COUNT (bb1
->succs
) == 0
225 || EDGE_COUNT (bb2
->succs
) == 0)
228 /* Find the bb which is the fall through to the other. */
229 if (EDGE_SUCC (bb1
, 0)->dest
== bb2
)
231 else if (EDGE_SUCC (bb2
, 0)->dest
== bb1
)
233 std::swap (bb1
, bb2
);
236 else if (do_store_elim
237 && EDGE_SUCC (bb1
, 0)->dest
== EDGE_SUCC (bb2
, 0)->dest
)
239 basic_block bb3
= EDGE_SUCC (bb1
, 0)->dest
;
241 if (!single_succ_p (bb1
)
242 || (EDGE_SUCC (bb1
, 0)->flags
& EDGE_FALLTHRU
) == 0
243 || !single_succ_p (bb2
)
244 || (EDGE_SUCC (bb2
, 0)->flags
& EDGE_FALLTHRU
) == 0
245 || EDGE_COUNT (bb3
->preds
) != 2)
247 if (cond_if_else_store_replacement (bb1
, bb2
, bb3
))
251 else if (do_hoist_loads
252 && EDGE_SUCC (bb1
, 0)->dest
== EDGE_SUCC (bb2
, 0)->dest
)
254 basic_block bb3
= EDGE_SUCC (bb1
, 0)->dest
;
256 if (!FLOAT_TYPE_P (TREE_TYPE (gimple_cond_lhs (cond_stmt
)))
257 && single_succ_p (bb1
)
258 && single_succ_p (bb2
)
259 && single_pred_p (bb1
)
260 && single_pred_p (bb2
)
261 && EDGE_COUNT (bb
->succs
) == 2
262 && EDGE_COUNT (bb3
->preds
) == 2
263 /* If one edge or the other is dominant, a conditional move
264 is likely to perform worse than the well-predicted branch. */
265 && !predictable_edge_p (EDGE_SUCC (bb
, 0))
266 && !predictable_edge_p (EDGE_SUCC (bb
, 1)))
267 hoist_adjacent_loads (bb
, bb1
, bb2
, bb3
);
273 e1
= EDGE_SUCC (bb1
, 0);
275 /* Make sure that bb1 is just a fall through. */
276 if (!single_succ_p (bb1
)
277 || (e1
->flags
& EDGE_FALLTHRU
) == 0)
280 /* Also make sure that bb1 only have one predecessor and that it
282 if (!single_pred_p (bb1
)
283 || single_pred (bb1
) != bb
)
288 /* bb1 is the middle block, bb2 the join block, bb the split block,
289 e1 the fallthrough edge from bb1 to bb2. We can't do the
290 optimization if the join block has more than two predecessors. */
291 if (EDGE_COUNT (bb2
->preds
) > 2)
293 if (cond_store_replacement (bb1
, bb2
, e1
, e2
, nontrap
))
298 gimple_seq phis
= phi_nodes (bb2
);
299 gimple_stmt_iterator gsi
;
300 bool candorest
= true;
302 /* Value replacement can work with more than one PHI
303 so try that first. */
305 for (gsi
= gsi_start (phis
); !gsi_end_p (gsi
); gsi_next (&gsi
))
307 phi
= as_a
<gphi
*> (gsi_stmt (gsi
));
308 arg0
= gimple_phi_arg_def (phi
, e1
->dest_idx
);
309 arg1
= gimple_phi_arg_def (phi
, e2
->dest_idx
);
310 if (value_replacement (bb
, bb1
, e1
, e2
, phi
, arg0
, arg1
) == 2)
321 phi
= single_non_singleton_phi_for_edges (phis
, e1
, e2
);
325 arg0
= gimple_phi_arg_def (phi
, e1
->dest_idx
);
326 arg1
= gimple_phi_arg_def (phi
, e2
->dest_idx
);
328 /* Something is wrong if we cannot find the arguments in the PHI
330 gcc_assert (arg0
!= NULL_TREE
&& arg1
!= NULL_TREE
);
332 gphi
*newphi
= factor_out_conditional_conversion (e1
, e2
, phi
,
338 /* factor_out_conditional_conversion may create a new PHI in
339 BB2 and eliminate an existing PHI in BB2. Recompute values
340 that may be affected by that change. */
341 arg0
= gimple_phi_arg_def (phi
, e1
->dest_idx
);
342 arg1
= gimple_phi_arg_def (phi
, e2
->dest_idx
);
343 gcc_assert (arg0
!= NULL_TREE
&& arg1
!= NULL_TREE
);
346 /* Do the replacement of conditional if it can be done. */
347 if (!early_p
&& two_value_replacement (bb
, bb1
, e2
, phi
, arg0
, arg1
))
349 else if (match_simplify_replacement (bb
, bb1
, e1
, e2
, phi
,
353 else if (abs_replacement (bb
, bb1
, e1
, e2
, phi
, arg0
, arg1
))
356 && cond_removal_in_popcount_clz_ctz_pattern (bb
, bb1
, e1
,
360 else if (minmax_replacement (bb
, bb1
, e1
, e2
, phi
, arg0
, arg1
))
362 else if (spaceship_replacement (bb
, bb1
, e1
, e2
, phi
, arg0
, arg1
))
371 /* If the CFG has changed, we should cleanup the CFG. */
372 if (cfgchanged
&& do_store_elim
)
374 /* In cond-store replacement we have added some loads on edges
375 and new VOPS (as we moved the store, and created a load). */
376 gsi_commit_edge_inserts ();
377 return TODO_cleanup_cfg
| TODO_update_ssa_only_virtuals
;
380 return TODO_cleanup_cfg
;
384 /* Replace PHI node element whose edge is E in block BB with variable NEW.
385 Remove the edge from COND_BLOCK which does not lead to BB (COND_BLOCK
386 is known to have two edges, one of which must reach BB). */
389 replace_phi_edge_with_variable (basic_block cond_block
,
390 edge e
, gphi
*phi
, tree new_tree
)
392 basic_block bb
= gimple_bb (phi
);
393 basic_block block_to_remove
;
394 gimple_stmt_iterator gsi
;
395 tree phi_result
= PHI_RESULT (phi
);
397 /* Duplicate range info if we're the only things setting the target PHI.
398 This is needed as later on, the new_tree will be replacing
399 The assignement of the PHI.
410 And _4 gets prograted into the use of a_3 and losing the range info.
411 This can't be done for more than 2 incoming edges as the progration
413 if (TREE_CODE (new_tree
) == SSA_NAME
414 && EDGE_COUNT (gimple_bb (phi
)->preds
) == 2
415 && INTEGRAL_TYPE_P (TREE_TYPE (phi_result
))
416 && !SSA_NAME_RANGE_INFO (new_tree
)
417 && SSA_NAME_RANGE_INFO (phi_result
))
418 duplicate_ssa_name_range_info (new_tree
,
419 SSA_NAME_RANGE_TYPE (phi_result
),
420 SSA_NAME_RANGE_INFO (phi_result
));
422 /* Change the PHI argument to new. */
423 SET_USE (PHI_ARG_DEF_PTR (phi
, e
->dest_idx
), new_tree
);
425 /* Remove the empty basic block. */
426 if (EDGE_SUCC (cond_block
, 0)->dest
== bb
)
428 EDGE_SUCC (cond_block
, 0)->flags
|= EDGE_FALLTHRU
;
429 EDGE_SUCC (cond_block
, 0)->flags
&= ~(EDGE_TRUE_VALUE
| EDGE_FALSE_VALUE
);
430 EDGE_SUCC (cond_block
, 0)->probability
= profile_probability::always ();
432 block_to_remove
= EDGE_SUCC (cond_block
, 1)->dest
;
436 EDGE_SUCC (cond_block
, 1)->flags
|= EDGE_FALLTHRU
;
437 EDGE_SUCC (cond_block
, 1)->flags
438 &= ~(EDGE_TRUE_VALUE
| EDGE_FALSE_VALUE
);
439 EDGE_SUCC (cond_block
, 1)->probability
= profile_probability::always ();
441 block_to_remove
= EDGE_SUCC (cond_block
, 0)->dest
;
443 delete_basic_block (block_to_remove
);
445 /* Eliminate the COND_EXPR at the end of COND_BLOCK. */
446 gsi
= gsi_last_bb (cond_block
);
447 gsi_remove (&gsi
, true);
449 statistics_counter_event (cfun
, "Replace PHI with variable", 1);
451 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
453 "COND_EXPR in block %d and PHI in block %d converted to straightline code.\n",
458 /* PR66726: Factor conversion out of COND_EXPR. If the arguments of the PHI
459 stmt are CONVERT_STMT, factor out the conversion and perform the conversion
460 to the result of PHI stmt. COND_STMT is the controlling predicate.
461 Return the newly-created PHI, if any. */
464 factor_out_conditional_conversion (edge e0
, edge e1
, gphi
*phi
,
465 tree arg0
, tree arg1
, gimple
*cond_stmt
)
467 gimple
*arg0_def_stmt
= NULL
, *arg1_def_stmt
= NULL
, *new_stmt
;
468 tree new_arg0
= NULL_TREE
, new_arg1
= NULL_TREE
;
471 gimple_stmt_iterator gsi
, gsi_for_def
;
472 location_t locus
= gimple_location (phi
);
473 enum tree_code convert_code
;
475 /* Handle only PHI statements with two arguments. TODO: If all
476 other arguments to PHI are INTEGER_CST or if their defining
477 statement have the same unary operation, we can handle more
478 than two arguments too. */
479 if (gimple_phi_num_args (phi
) != 2)
482 /* First canonicalize to simplify tests. */
483 if (TREE_CODE (arg0
) != SSA_NAME
)
485 std::swap (arg0
, arg1
);
489 if (TREE_CODE (arg0
) != SSA_NAME
490 || (TREE_CODE (arg1
) != SSA_NAME
491 && TREE_CODE (arg1
) != INTEGER_CST
))
494 /* Check if arg0 is an SSA_NAME and the stmt which defines arg0 is
496 arg0_def_stmt
= SSA_NAME_DEF_STMT (arg0
);
497 if (!gimple_assign_cast_p (arg0_def_stmt
))
500 /* Use the RHS as new_arg0. */
501 convert_code
= gimple_assign_rhs_code (arg0_def_stmt
);
502 new_arg0
= gimple_assign_rhs1 (arg0_def_stmt
);
503 if (convert_code
== VIEW_CONVERT_EXPR
)
505 new_arg0
= TREE_OPERAND (new_arg0
, 0);
506 if (!is_gimple_reg_type (TREE_TYPE (new_arg0
)))
509 if (TREE_CODE (new_arg0
) == SSA_NAME
510 && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (new_arg0
))
513 if (TREE_CODE (arg1
) == SSA_NAME
)
515 /* Check if arg1 is an SSA_NAME and the stmt which defines arg1
517 arg1_def_stmt
= SSA_NAME_DEF_STMT (arg1
);
518 if (!is_gimple_assign (arg1_def_stmt
)
519 || gimple_assign_rhs_code (arg1_def_stmt
) != convert_code
)
522 /* Either arg1_def_stmt or arg0_def_stmt should be conditional. */
523 if (dominated_by_p (CDI_DOMINATORS
, gimple_bb (phi
), gimple_bb (arg0_def_stmt
))
524 && dominated_by_p (CDI_DOMINATORS
,
525 gimple_bb (phi
), gimple_bb (arg1_def_stmt
)))
528 /* Use the RHS as new_arg1. */
529 new_arg1
= gimple_assign_rhs1 (arg1_def_stmt
);
530 if (convert_code
== VIEW_CONVERT_EXPR
)
531 new_arg1
= TREE_OPERAND (new_arg1
, 0);
532 if (TREE_CODE (new_arg1
) == SSA_NAME
533 && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (new_arg1
))
538 /* arg0_def_stmt should be conditional. */
539 if (dominated_by_p (CDI_DOMINATORS
, gimple_bb (phi
), gimple_bb (arg0_def_stmt
)))
541 /* If arg1 is an INTEGER_CST, fold it to new type. */
542 if (INTEGRAL_TYPE_P (TREE_TYPE (new_arg0
))
543 && int_fits_type_p (arg1
, TREE_TYPE (new_arg0
)))
545 if (gimple_assign_cast_p (arg0_def_stmt
))
547 /* For the INTEGER_CST case, we are just moving the
548 conversion from one place to another, which can often
549 hurt as the conversion moves further away from the
550 statement that computes the value. So, perform this
551 only if new_arg0 is an operand of COND_STMT, or
552 if arg0_def_stmt is the only non-debug stmt in
553 its basic block, because then it is possible this
554 could enable further optimizations (minmax replacement
555 etc.). See PR71016. */
556 if (new_arg0
!= gimple_cond_lhs (cond_stmt
)
557 && new_arg0
!= gimple_cond_rhs (cond_stmt
)
558 && gimple_bb (arg0_def_stmt
) == e0
->src
)
560 gsi
= gsi_for_stmt (arg0_def_stmt
);
561 gsi_prev_nondebug (&gsi
);
562 if (!gsi_end_p (gsi
))
565 = dyn_cast
<gassign
*> (gsi_stmt (gsi
)))
567 tree lhs
= gimple_assign_lhs (assign
);
568 enum tree_code ass_code
569 = gimple_assign_rhs_code (assign
);
570 if (ass_code
!= MAX_EXPR
&& ass_code
!= MIN_EXPR
)
572 if (lhs
!= gimple_assign_rhs1 (arg0_def_stmt
))
574 gsi_prev_nondebug (&gsi
);
575 if (!gsi_end_p (gsi
))
581 gsi
= gsi_for_stmt (arg0_def_stmt
);
582 gsi_next_nondebug (&gsi
);
583 if (!gsi_end_p (gsi
))
586 new_arg1
= fold_convert (TREE_TYPE (new_arg0
), arg1
);
595 /* If arg0/arg1 have > 1 use, then this transformation actually increases
596 the number of expressions evaluated at runtime. */
597 if (!has_single_use (arg0
)
598 || (arg1_def_stmt
&& !has_single_use (arg1
)))
601 /* If types of new_arg0 and new_arg1 are different bailout. */
602 if (!types_compatible_p (TREE_TYPE (new_arg0
), TREE_TYPE (new_arg1
)))
605 /* Create a new PHI stmt. */
606 result
= PHI_RESULT (phi
);
607 temp
= make_ssa_name (TREE_TYPE (new_arg0
), NULL
);
608 newphi
= create_phi_node (temp
, gimple_bb (phi
));
610 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
612 fprintf (dump_file
, "PHI ");
613 print_generic_expr (dump_file
, gimple_phi_result (phi
));
615 " changed to factor conversion out from COND_EXPR.\n");
616 fprintf (dump_file
, "New stmt with CAST that defines ");
617 print_generic_expr (dump_file
, result
);
618 fprintf (dump_file
, ".\n");
621 /* Remove the old cast(s) that has single use. */
622 gsi_for_def
= gsi_for_stmt (arg0_def_stmt
);
623 gsi_remove (&gsi_for_def
, true);
624 release_defs (arg0_def_stmt
);
628 gsi_for_def
= gsi_for_stmt (arg1_def_stmt
);
629 gsi_remove (&gsi_for_def
, true);
630 release_defs (arg1_def_stmt
);
633 add_phi_arg (newphi
, new_arg0
, e0
, locus
);
634 add_phi_arg (newphi
, new_arg1
, e1
, locus
);
636 /* Create the conversion stmt and insert it. */
637 if (convert_code
== VIEW_CONVERT_EXPR
)
639 temp
= fold_build1 (VIEW_CONVERT_EXPR
, TREE_TYPE (result
), temp
);
640 new_stmt
= gimple_build_assign (result
, temp
);
643 new_stmt
= gimple_build_assign (result
, convert_code
, temp
);
644 gsi
= gsi_after_labels (gimple_bb (phi
));
645 gsi_insert_before (&gsi
, new_stmt
, GSI_SAME_STMT
);
647 /* Remove the original PHI stmt. */
648 gsi
= gsi_for_stmt (phi
);
649 gsi_remove (&gsi
, true);
651 statistics_counter_event (cfun
, "factored out cast", 1);
657 # x_5 in range [cst1, cst2] where cst2 = cst1 + 1
658 if (x_5 op cstN) # where op is == or != and N is 1 or 2
664 # r_6 = PHI<cst3(2), cst4(3)> # where cst3 == cst4 + 1 or cst4 == cst3 + 1
666 to r_6 = x_5 + (min (cst3, cst4) - cst1) or
667 r_6 = (min (cst3, cst4) + cst1) - x_5 depending on op, N and which
668 of cst3 and cst4 is smaller. */
671 two_value_replacement (basic_block cond_bb
, basic_block middle_bb
,
672 edge e1
, gphi
*phi
, tree arg0
, tree arg1
)
674 /* Only look for adjacent integer constants. */
675 if (!INTEGRAL_TYPE_P (TREE_TYPE (arg0
))
676 || !INTEGRAL_TYPE_P (TREE_TYPE (arg1
))
677 || TREE_CODE (arg0
) != INTEGER_CST
678 || TREE_CODE (arg1
) != INTEGER_CST
679 || (tree_int_cst_lt (arg0
, arg1
)
680 ? wi::to_widest (arg0
) + 1 != wi::to_widest (arg1
)
681 : wi::to_widest (arg1
) + 1 != wi::to_widest (arg0
)))
684 if (!empty_block_p (middle_bb
))
687 gimple
*stmt
= last_stmt (cond_bb
);
688 tree lhs
= gimple_cond_lhs (stmt
);
689 tree rhs
= gimple_cond_rhs (stmt
);
691 if (TREE_CODE (lhs
) != SSA_NAME
692 || !INTEGRAL_TYPE_P (TREE_TYPE (lhs
))
693 || TREE_CODE (rhs
) != INTEGER_CST
)
696 switch (gimple_cond_code (stmt
))
705 /* Defer boolean x ? 0 : {1,-1} or x ? {1,-1} : 0 to
706 match_simplify_replacement. */
707 if (TREE_CODE (TREE_TYPE (lhs
)) == BOOLEAN_TYPE
708 && (integer_zerop (arg0
)
709 || integer_zerop (arg1
)
710 || TREE_CODE (TREE_TYPE (arg0
)) == BOOLEAN_TYPE
711 || (TYPE_PRECISION (TREE_TYPE (arg0
))
712 <= TYPE_PRECISION (TREE_TYPE (lhs
)))))
717 get_range_query (cfun
)->range_of_expr (r
, lhs
);
719 if (r
.kind () == VR_RANGE
)
721 min
= r
.lower_bound ();
722 max
= r
.upper_bound ();
726 int prec
= TYPE_PRECISION (TREE_TYPE (lhs
));
727 signop sgn
= TYPE_SIGN (TREE_TYPE (lhs
));
728 min
= wi::min_value (prec
, sgn
);
729 max
= wi::max_value (prec
, sgn
);
732 || (wi::to_wide (rhs
) != min
733 && wi::to_wide (rhs
) != max
))
736 /* We need to know which is the true edge and which is the false
737 edge so that we know when to invert the condition below. */
738 edge true_edge
, false_edge
;
739 extract_true_false_edges_from_block (cond_bb
, &true_edge
, &false_edge
);
740 if ((gimple_cond_code (stmt
) == EQ_EXPR
)
741 ^ (wi::to_wide (rhs
) == max
)
742 ^ (e1
== false_edge
))
743 std::swap (arg0
, arg1
);
746 if (TYPE_PRECISION (TREE_TYPE (lhs
)) == TYPE_PRECISION (TREE_TYPE (arg0
)))
748 /* Avoid performing the arithmetics in bool type which has different
749 semantics, otherwise prefer unsigned types from the two with
750 the same precision. */
751 if (TREE_CODE (TREE_TYPE (arg0
)) == BOOLEAN_TYPE
752 || !TYPE_UNSIGNED (TREE_TYPE (arg0
)))
753 type
= TREE_TYPE (lhs
);
755 type
= TREE_TYPE (arg0
);
757 else if (TYPE_PRECISION (TREE_TYPE (lhs
)) > TYPE_PRECISION (TREE_TYPE (arg0
)))
758 type
= TREE_TYPE (lhs
);
760 type
= TREE_TYPE (arg0
);
762 min
= wide_int::from (min
, TYPE_PRECISION (type
),
763 TYPE_SIGN (TREE_TYPE (lhs
)));
764 wide_int a
= wide_int::from (wi::to_wide (arg0
), TYPE_PRECISION (type
),
765 TYPE_SIGN (TREE_TYPE (arg0
)));
767 wi::overflow_type ovf
;
768 if (tree_int_cst_lt (arg0
, arg1
))
772 if (!TYPE_UNSIGNED (type
))
774 /* lhs is known to be in range [min, min+1] and we want to add a
775 to it. Check if that operation can overflow for those 2 values
776 and if yes, force unsigned type. */
777 wi::add (min
+ (wi::neg_p (a
) ? 0 : 1), a
, SIGNED
, &ovf
);
779 type
= unsigned_type_for (type
);
786 if (!TYPE_UNSIGNED (type
))
788 /* lhs is known to be in range [min, min+1] and we want to subtract
789 it from a. Check if that operation can overflow for those 2
790 values and if yes, force unsigned type. */
791 wi::sub (a
, min
+ (wi::neg_p (min
) ? 0 : 1), SIGNED
, &ovf
);
793 type
= unsigned_type_for (type
);
797 tree arg
= wide_int_to_tree (type
, a
);
798 gimple_seq stmts
= NULL
;
799 lhs
= gimple_convert (&stmts
, type
, lhs
);
801 if (code
== PLUS_EXPR
)
802 new_rhs
= gimple_build (&stmts
, PLUS_EXPR
, type
, lhs
, arg
);
804 new_rhs
= gimple_build (&stmts
, MINUS_EXPR
, type
, arg
, lhs
);
805 new_rhs
= gimple_convert (&stmts
, TREE_TYPE (arg0
), new_rhs
);
806 gimple_stmt_iterator gsi
= gsi_for_stmt (stmt
);
807 gsi_insert_seq_before (&gsi
, stmts
, GSI_SAME_STMT
);
809 replace_phi_edge_with_variable (cond_bb
, e1
, phi
, new_rhs
);
811 /* Note that we optimized this PHI. */
815 /* Return TRUE if CODE should be allowed during early phiopt.
816 Currently this is to allow MIN/MAX and ABS/NEGATE. */
818 phiopt_early_allow (enum tree_code code
)
834 /* gimple_simplify_phiopt is like gimple_simplify but designed for PHIOPT.
835 Return NULL if nothing can be simplified or the resulting simplified value
836 with parts pushed if EARLY_P was true. Also rejects non allowed tree code
838 Takes the comparison from COMP_STMT and two args, ARG0 and ARG1 and tries
839 to simplify CMP ? ARG0 : ARG1.
840 Also try to simplify (!CMP) ? ARG1 : ARG0 if the non-inverse failed. */
842 gimple_simplify_phiopt (bool early_p
, tree type
, gimple
*comp_stmt
,
843 tree arg0
, tree arg1
,
847 enum tree_code comp_code
= gimple_cond_code (comp_stmt
);
848 location_t loc
= gimple_location (comp_stmt
);
849 tree cmp0
= gimple_cond_lhs (comp_stmt
);
850 tree cmp1
= gimple_cond_rhs (comp_stmt
);
851 /* To handle special cases like floating point comparison, it is easier and
852 less error-prone to build a tree and gimplify it on the fly though it is
854 Don't use fold_build2 here as that might create (bool)a instead of just
856 tree cond
= build2_loc (loc
, comp_code
, boolean_type_node
,
858 gimple_match_op
op (gimple_match_cond::UNCOND
,
859 COND_EXPR
, type
, cond
, arg0
, arg1
);
861 if (op
.resimplify (early_p
? NULL
: seq
, follow_all_ssa_edges
))
863 /* Early we want only to allow some generated tree codes. */
865 || op
.code
.is_tree_code ()
866 || phiopt_early_allow ((tree_code
)op
.code
))
868 result
= maybe_push_res_to_seq (&op
, seq
);
873 /* Try the inverted comparison, that is !COMP ? ARG1 : ARG0. */
874 comp_code
= invert_tree_comparison (comp_code
, HONOR_NANS (cmp0
));
876 if (comp_code
== ERROR_MARK
)
879 cond
= build2_loc (loc
,
880 comp_code
, boolean_type_node
,
882 gimple_match_op
op1 (gimple_match_cond::UNCOND
,
883 COND_EXPR
, type
, cond
, arg1
, arg0
);
885 if (op1
.resimplify (early_p
? NULL
: seq
, follow_all_ssa_edges
))
887 /* Early we want only to allow some generated tree codes. */
889 || op1
.code
.is_tree_code ()
890 || phiopt_early_allow ((tree_code
)op1
.code
))
892 result
= maybe_push_res_to_seq (&op1
, seq
);
901 /* The function match_simplify_replacement does the main work of doing the
902 replacement using match and simplify. Return true if the replacement is done.
903 Otherwise return false.
904 BB is the basic block where the replacement is going to be done on. ARG0
905 is argument 0 from PHI. Likewise for ARG1. */
908 match_simplify_replacement (basic_block cond_bb
, basic_block middle_bb
,
909 edge e0
, edge e1
, gphi
*phi
,
910 tree arg0
, tree arg1
, bool early_p
)
913 gimple_stmt_iterator gsi
;
914 edge true_edge
, false_edge
;
915 gimple_seq seq
= NULL
;
917 gimple
*stmt_to_move
= NULL
;
919 /* Special case A ? B : B as this will always simplify to B. */
920 if (operand_equal_for_phi_arg_p (arg0
, arg1
))
923 /* If the basic block only has a cheap preparation statement,
924 allow it and move it once the transformation is done. */
925 if (!empty_block_p (middle_bb
))
927 stmt_to_move
= last_and_only_stmt (middle_bb
);
931 if (gimple_vuse (stmt_to_move
))
934 if (gimple_could_trap_p (stmt_to_move
)
935 || gimple_has_side_effects (stmt_to_move
))
938 if (gimple_uses_undefined_value_p (stmt_to_move
))
941 /* Allow assignments and not no calls.
942 As const calls don't match any of the above, yet they could
943 still have some side-effects - they could contain
944 gimple_could_trap_p statements, like floating point
945 exceptions or integer division by zero. See PR70586.
946 FIXME: perhaps gimple_has_side_effects or gimple_could_trap_p
947 should handle this. */
948 if (!is_gimple_assign (stmt_to_move
))
951 tree lhs
= gimple_assign_lhs (stmt_to_move
);
955 /* Allow only a statement which feeds into the phi. */
956 if (!lhs
|| TREE_CODE (lhs
) != SSA_NAME
957 || !single_imm_use (lhs
, &use_p
, &use_stmt
)
962 /* At this point we know we have a GIMPLE_COND with two successors.
963 One successor is BB, the other successor is an empty block which
964 falls through into BB.
966 There is a single PHI node at the join point (BB).
968 So, given the condition COND, and the two PHI arguments, match and simplify
969 can happen on (COND) ? arg0 : arg1. */
971 stmt
= last_stmt (cond_bb
);
973 /* We need to know which is the true edge and which is the false
974 edge so that we know when to invert the condition below. */
975 extract_true_false_edges_from_block (cond_bb
, &true_edge
, &false_edge
);
976 if (e1
== true_edge
|| e0
== false_edge
)
977 std::swap (arg0
, arg1
);
979 tree type
= TREE_TYPE (gimple_phi_result (phi
));
980 result
= gimple_simplify_phiopt (early_p
, type
, stmt
,
986 gsi
= gsi_last_bb (cond_bb
);
989 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
991 fprintf (dump_file
, "statement un-sinked:\n");
992 print_gimple_stmt (dump_file
, stmt_to_move
, 0,
993 TDF_VOPS
|TDF_MEMSYMS
);
995 gimple_stmt_iterator gsi1
= gsi_for_stmt (stmt_to_move
);
996 gsi_move_before (&gsi1
, &gsi
);
997 reset_flow_sensitive_info (gimple_assign_lhs (stmt_to_move
));
1000 gsi_insert_seq_before (&gsi
, seq
, GSI_SAME_STMT
);
1002 replace_phi_edge_with_variable (cond_bb
, e1
, phi
, result
);
1004 /* Add Statistic here even though replace_phi_edge_with_variable already
1005 does it as we want to be able to count when match-simplify happens vs
1007 statistics_counter_event (cfun
, "match-simplify PHI replacement", 1);
1009 /* Note that we optimized this PHI. */
1013 /* Update *ARG which is defined in STMT so that it contains the
1014 computed value if that seems profitable. Return true if the
1015 statement is made dead by that rewriting. */
1018 jump_function_from_stmt (tree
*arg
, gimple
*stmt
)
1020 enum tree_code code
= gimple_assign_rhs_code (stmt
);
1021 if (code
== ADDR_EXPR
)
1023 /* For arg = &p->i transform it to p, if possible. */
1024 tree rhs1
= gimple_assign_rhs1 (stmt
);
1026 tree tem
= get_addr_base_and_unit_offset (TREE_OPERAND (rhs1
, 0),
1029 && TREE_CODE (tem
) == MEM_REF
1030 && known_eq (mem_ref_offset (tem
) + offset
, 0))
1032 *arg
= TREE_OPERAND (tem
, 0);
1036 /* TODO: Much like IPA-CP jump-functions we want to handle constant
1037 additions symbolically here, and we'd need to update the comparison
1038 code that compares the arg + cst tuples in our caller. For now the
1039 code above exactly handles the VEC_BASE pattern from vec.h. */
1043 /* RHS is a source argument in a BIT_AND_EXPR which feeds a conditional
1044 of the form SSA_NAME NE 0.
1046 If RHS is fed by a simple EQ_EXPR comparison of two values, see if
1047 the two input values of the EQ_EXPR match arg0 and arg1.
1049 If so update *code and return TRUE. Otherwise return FALSE. */
1052 rhs_is_fed_for_value_replacement (const_tree arg0
, const_tree arg1
,
1053 enum tree_code
*code
, const_tree rhs
)
1055 /* Obviously if RHS is not an SSA_NAME, we can't look at the defining
1057 if (TREE_CODE (rhs
) == SSA_NAME
)
1059 gimple
*def1
= SSA_NAME_DEF_STMT (rhs
);
1061 /* Verify the defining statement has an EQ_EXPR on the RHS. */
1062 if (is_gimple_assign (def1
) && gimple_assign_rhs_code (def1
) == EQ_EXPR
)
1064 /* Finally verify the source operands of the EQ_EXPR are equal
1065 to arg0 and arg1. */
1066 tree op0
= gimple_assign_rhs1 (def1
);
1067 tree op1
= gimple_assign_rhs2 (def1
);
1068 if ((operand_equal_for_phi_arg_p (arg0
, op0
)
1069 && operand_equal_for_phi_arg_p (arg1
, op1
))
1070 || (operand_equal_for_phi_arg_p (arg0
, op1
)
1071 && operand_equal_for_phi_arg_p (arg1
, op0
)))
1073 /* We will perform the optimization. */
1074 *code
= gimple_assign_rhs_code (def1
);
1082 /* Return TRUE if arg0/arg1 are equal to the rhs/lhs or lhs/rhs of COND.
1084 Also return TRUE if arg0/arg1 are equal to the source arguments of a
1085 an EQ comparison feeding a BIT_AND_EXPR which feeds COND.
1087 Return FALSE otherwise. */
1090 operand_equal_for_value_replacement (const_tree arg0
, const_tree arg1
,
1091 enum tree_code
*code
, gimple
*cond
)
1094 tree lhs
= gimple_cond_lhs (cond
);
1095 tree rhs
= gimple_cond_rhs (cond
);
1097 if ((operand_equal_for_phi_arg_p (arg0
, lhs
)
1098 && operand_equal_for_phi_arg_p (arg1
, rhs
))
1099 || (operand_equal_for_phi_arg_p (arg1
, lhs
)
1100 && operand_equal_for_phi_arg_p (arg0
, rhs
)))
1103 /* Now handle more complex case where we have an EQ comparison
1104 which feeds a BIT_AND_EXPR which feeds COND.
1106 First verify that COND is of the form SSA_NAME NE 0. */
1107 if (*code
!= NE_EXPR
|| !integer_zerop (rhs
)
1108 || TREE_CODE (lhs
) != SSA_NAME
)
1111 /* Now ensure that SSA_NAME is set by a BIT_AND_EXPR. */
1112 def
= SSA_NAME_DEF_STMT (lhs
);
1113 if (!is_gimple_assign (def
) || gimple_assign_rhs_code (def
) != BIT_AND_EXPR
)
1116 /* Now verify arg0/arg1 correspond to the source arguments of an
1117 EQ comparison feeding the BIT_AND_EXPR. */
1119 tree tmp
= gimple_assign_rhs1 (def
);
1120 if (rhs_is_fed_for_value_replacement (arg0
, arg1
, code
, tmp
))
1123 tmp
= gimple_assign_rhs2 (def
);
1124 if (rhs_is_fed_for_value_replacement (arg0
, arg1
, code
, tmp
))
1130 /* Returns true if ARG is a neutral element for operation CODE
1131 on the RIGHT side. */
1134 neutral_element_p (tree_code code
, tree arg
, bool right
)
1141 return integer_zerop (arg
);
1148 case POINTER_PLUS_EXPR
:
1149 return right
&& integer_zerop (arg
);
1152 return integer_onep (arg
);
1154 case TRUNC_DIV_EXPR
:
1156 case FLOOR_DIV_EXPR
:
1157 case ROUND_DIV_EXPR
:
1158 case EXACT_DIV_EXPR
:
1159 return right
&& integer_onep (arg
);
1162 return integer_all_onesp (arg
);
1169 /* Returns true if ARG is an absorbing element for operation CODE. */
1172 absorbing_element_p (tree_code code
, tree arg
, bool right
, tree rval
)
1177 return integer_all_onesp (arg
);
1181 return integer_zerop (arg
);
1187 return !right
&& integer_zerop (arg
);
1189 case TRUNC_DIV_EXPR
:
1191 case FLOOR_DIV_EXPR
:
1192 case ROUND_DIV_EXPR
:
1193 case EXACT_DIV_EXPR
:
1194 case TRUNC_MOD_EXPR
:
1196 case FLOOR_MOD_EXPR
:
1197 case ROUND_MOD_EXPR
:
1199 && integer_zerop (arg
)
1200 && tree_single_nonzero_warnv_p (rval
, NULL
));
1207 /* The function value_replacement does the main work of doing the value
1208 replacement. Return non-zero if the replacement is done. Otherwise return
1209 0. If we remove the middle basic block, return 2.
1210 BB is the basic block where the replacement is going to be done on. ARG0
1211 is argument 0 from the PHI. Likewise for ARG1. */
1214 value_replacement (basic_block cond_bb
, basic_block middle_bb
,
1215 edge e0
, edge e1
, gphi
*phi
, tree arg0
, tree arg1
)
1217 gimple_stmt_iterator gsi
;
1219 edge true_edge
, false_edge
;
1220 enum tree_code code
;
1221 bool empty_or_with_defined_p
= true;
1223 /* If the type says honor signed zeros we cannot do this
1225 if (HONOR_SIGNED_ZEROS (arg1
))
1228 /* If there is a statement in MIDDLE_BB that defines one of the PHI
1229 arguments, then adjust arg0 or arg1. */
1230 gsi
= gsi_start_nondebug_after_labels_bb (middle_bb
);
1231 while (!gsi_end_p (gsi
))
1233 gimple
*stmt
= gsi_stmt (gsi
);
1235 gsi_next_nondebug (&gsi
);
1236 if (!is_gimple_assign (stmt
))
1238 if (gimple_code (stmt
) != GIMPLE_PREDICT
1239 && gimple_code (stmt
) != GIMPLE_NOP
)
1240 empty_or_with_defined_p
= false;
1243 /* Now try to adjust arg0 or arg1 according to the computation
1244 in the statement. */
1245 lhs
= gimple_assign_lhs (stmt
);
1247 && jump_function_from_stmt (&arg0
, stmt
))
1249 && jump_function_from_stmt (&arg1
, stmt
)))
1250 empty_or_with_defined_p
= false;
1253 cond
= last_stmt (cond_bb
);
1254 code
= gimple_cond_code (cond
);
1256 /* This transformation is only valid for equality comparisons. */
1257 if (code
!= NE_EXPR
&& code
!= EQ_EXPR
)
1260 /* We need to know which is the true edge and which is the false
1261 edge so that we know if have abs or negative abs. */
1262 extract_true_false_edges_from_block (cond_bb
, &true_edge
, &false_edge
);
1264 /* At this point we know we have a COND_EXPR with two successors.
1265 One successor is BB, the other successor is an empty block which
1266 falls through into BB.
1268 The condition for the COND_EXPR is known to be NE_EXPR or EQ_EXPR.
1270 There is a single PHI node at the join point (BB) with two arguments.
1272 We now need to verify that the two arguments in the PHI node match
1273 the two arguments to the equality comparison. */
1275 if (operand_equal_for_value_replacement (arg0
, arg1
, &code
, cond
))
1280 /* For NE_EXPR, we want to build an assignment result = arg where
1281 arg is the PHI argument associated with the true edge. For
1282 EQ_EXPR we want the PHI argument associated with the false edge. */
1283 e
= (code
== NE_EXPR
? true_edge
: false_edge
);
1285 /* Unfortunately, E may not reach BB (it may instead have gone to
1286 OTHER_BLOCK). If that is the case, then we want the single outgoing
1287 edge from OTHER_BLOCK which reaches BB and represents the desired
1288 path from COND_BLOCK. */
1289 if (e
->dest
== middle_bb
)
1290 e
= single_succ_edge (e
->dest
);
1292 /* Now we know the incoming edge to BB that has the argument for the
1293 RHS of our new assignment statement. */
1299 /* If the middle basic block was empty or is defining the
1300 PHI arguments and this is a single phi where the args are different
1301 for the edges e0 and e1 then we can remove the middle basic block. */
1302 if (empty_or_with_defined_p
1303 && single_non_singleton_phi_for_edges (phi_nodes (gimple_bb (phi
)),
1306 replace_phi_edge_with_variable (cond_bb
, e1
, phi
, arg
);
1307 /* Note that we optimized this PHI. */
1312 statistics_counter_event (cfun
, "Replace PHI with variable/value_replacement", 1);
1314 /* Replace the PHI arguments with arg. */
1315 SET_PHI_ARG_DEF (phi
, e0
->dest_idx
, arg
);
1316 SET_PHI_ARG_DEF (phi
, e1
->dest_idx
, arg
);
1317 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
1319 fprintf (dump_file
, "PHI ");
1320 print_generic_expr (dump_file
, gimple_phi_result (phi
));
1321 fprintf (dump_file
, " reduced for COND_EXPR in block %d to ",
1323 print_generic_expr (dump_file
, arg
);
1324 fprintf (dump_file
, ".\n");
1331 /* Now optimize (x != 0) ? x + y : y to just x + y. */
1332 gsi
= gsi_last_nondebug_bb (middle_bb
);
1333 if (gsi_end_p (gsi
))
1336 gimple
*assign
= gsi_stmt (gsi
);
1337 if (!is_gimple_assign (assign
)
1338 || gimple_assign_rhs_class (assign
) != GIMPLE_BINARY_RHS
1339 || (!INTEGRAL_TYPE_P (TREE_TYPE (arg0
))
1340 && !POINTER_TYPE_P (TREE_TYPE (arg0
))))
1343 /* Punt if there are (degenerate) PHIs in middle_bb, there should not be. */
1344 if (!gimple_seq_empty_p (phi_nodes (middle_bb
)))
1347 /* Allow up to 2 cheap preparation statements that prepare argument
1355 iftmp.0_6 = x_5(D) r<< _1;
1357 # iftmp.0_2 = PHI <iftmp.0_6(3), x_5(D)(2)>
1368 # _2 = PHI <x_5(D)(2), _6(3)> */
1369 gimple
*prep_stmt
[2] = { NULL
, NULL
};
1371 for (prep_cnt
= 0; ; prep_cnt
++)
1373 gsi_prev_nondebug (&gsi
);
1374 if (gsi_end_p (gsi
))
1377 gimple
*g
= gsi_stmt (gsi
);
1378 if (gimple_code (g
) == GIMPLE_LABEL
)
1381 if (prep_cnt
== 2 || !is_gimple_assign (g
))
1384 tree lhs
= gimple_assign_lhs (g
);
1385 tree rhs1
= gimple_assign_rhs1 (g
);
1386 use_operand_p use_p
;
1388 if (TREE_CODE (lhs
) != SSA_NAME
1389 || TREE_CODE (rhs1
) != SSA_NAME
1390 || !INTEGRAL_TYPE_P (TREE_TYPE (lhs
))
1391 || !INTEGRAL_TYPE_P (TREE_TYPE (rhs1
))
1392 || !single_imm_use (lhs
, &use_p
, &use_stmt
)
1393 || use_stmt
!= (prep_cnt
? prep_stmt
[prep_cnt
- 1] : assign
))
1395 switch (gimple_assign_rhs_code (g
))
1403 if (TREE_CODE (gimple_assign_rhs2 (g
)) != INTEGER_CST
)
1409 prep_stmt
[prep_cnt
] = g
;
1412 /* Only transform if it removes the condition. */
1413 if (!single_non_singleton_phi_for_edges (phi_nodes (gimple_bb (phi
)), e0
, e1
))
1416 /* Size-wise, this is always profitable. */
1417 if (optimize_bb_for_speed_p (cond_bb
)
1418 /* The special case is useless if it has a low probability. */
1419 && profile_status_for_fn (cfun
) != PROFILE_ABSENT
1420 && EDGE_PRED (middle_bb
, 0)->probability
< profile_probability::even ()
1421 /* If assign is cheap, there is no point avoiding it. */
1422 && estimate_num_insns_seq (bb_seq (middle_bb
), &eni_time_weights
)
1423 >= 3 * estimate_num_insns (cond
, &eni_time_weights
))
1426 tree lhs
= gimple_assign_lhs (assign
);
1427 tree rhs1
= gimple_assign_rhs1 (assign
);
1428 tree rhs2
= gimple_assign_rhs2 (assign
);
1429 enum tree_code code_def
= gimple_assign_rhs_code (assign
);
1430 tree cond_lhs
= gimple_cond_lhs (cond
);
1431 tree cond_rhs
= gimple_cond_rhs (cond
);
1433 /* Propagate the cond_rhs constant through preparation stmts,
1434 make sure UB isn't invoked while doing that. */
1435 for (int i
= prep_cnt
- 1; i
>= 0; --i
)
1437 gimple
*g
= prep_stmt
[i
];
1438 tree grhs1
= gimple_assign_rhs1 (g
);
1439 if (!operand_equal_for_phi_arg_p (cond_lhs
, grhs1
))
1441 cond_lhs
= gimple_assign_lhs (g
);
1442 cond_rhs
= fold_convert (TREE_TYPE (grhs1
), cond_rhs
);
1443 if (TREE_CODE (cond_rhs
) != INTEGER_CST
1444 || TREE_OVERFLOW (cond_rhs
))
1446 if (gimple_assign_rhs_class (g
) == GIMPLE_BINARY_RHS
)
1448 cond_rhs
= int_const_binop (gimple_assign_rhs_code (g
), cond_rhs
,
1449 gimple_assign_rhs2 (g
));
1450 if (TREE_OVERFLOW (cond_rhs
))
1453 cond_rhs
= fold_convert (TREE_TYPE (cond_lhs
), cond_rhs
);
1454 if (TREE_CODE (cond_rhs
) != INTEGER_CST
1455 || TREE_OVERFLOW (cond_rhs
))
1459 if (((code
== NE_EXPR
&& e1
== false_edge
)
1460 || (code
== EQ_EXPR
&& e1
== true_edge
))
1463 && operand_equal_for_phi_arg_p (rhs2
, cond_lhs
)
1464 && neutral_element_p (code_def
, cond_rhs
, true))
1466 && operand_equal_for_phi_arg_p (rhs1
, cond_lhs
)
1467 && neutral_element_p (code_def
, cond_rhs
, false))
1468 || (operand_equal_for_phi_arg_p (arg1
, cond_rhs
)
1469 && ((operand_equal_for_phi_arg_p (rhs2
, cond_lhs
)
1470 && absorbing_element_p (code_def
, cond_rhs
, true, rhs2
))
1471 || (operand_equal_for_phi_arg_p (rhs1
, cond_lhs
)
1472 && absorbing_element_p (code_def
,
1473 cond_rhs
, false, rhs2
))))))
1475 gsi
= gsi_for_stmt (cond
);
1476 /* Moving ASSIGN might change VR of lhs, e.g. when moving u_6
1484 # RANGE [0, 4294967294]
1485 u_6 = n_5 + 4294967295;
1488 # u_3 = PHI <u_6(3), 4294967295(2)> */
1489 reset_flow_sensitive_info (lhs
);
1490 gimple_stmt_iterator gsi_from
;
1491 for (int i
= prep_cnt
- 1; i
>= 0; --i
)
1493 tree plhs
= gimple_assign_lhs (prep_stmt
[i
]);
1494 reset_flow_sensitive_info (plhs
);
1495 gsi_from
= gsi_for_stmt (prep_stmt
[i
]);
1496 gsi_move_before (&gsi_from
, &gsi
);
1498 gsi_from
= gsi_for_stmt (assign
);
1499 gsi_move_before (&gsi_from
, &gsi
);
1500 replace_phi_edge_with_variable (cond_bb
, e1
, phi
, lhs
);
1507 /* The function minmax_replacement does the main work of doing the minmax
1508 replacement. Return true if the replacement is done. Otherwise return
1510 BB is the basic block where the replacement is going to be done on. ARG0
1511 is argument 0 from the PHI. Likewise for ARG1. */
1514 minmax_replacement (basic_block cond_bb
, basic_block middle_bb
,
1515 edge e0
, edge e1
, gphi
*phi
, tree arg0
, tree arg1
)
1518 edge true_edge
, false_edge
;
1519 enum tree_code minmax
, ass_code
;
1520 tree smaller
, larger
, arg_true
, arg_false
;
1521 gimple_stmt_iterator gsi
, gsi_from
;
1523 tree type
= TREE_TYPE (PHI_RESULT (phi
));
1525 /* The optimization may be unsafe due to NaNs. */
1526 if (HONOR_NANS (type
) || HONOR_SIGNED_ZEROS (type
))
1529 gcond
*cond
= as_a
<gcond
*> (last_stmt (cond_bb
));
1530 enum tree_code cmp
= gimple_cond_code (cond
);
1531 tree rhs
= gimple_cond_rhs (cond
);
1533 /* Turn EQ/NE of extreme values to order comparisons. */
1534 if ((cmp
== NE_EXPR
|| cmp
== EQ_EXPR
)
1535 && TREE_CODE (rhs
) == INTEGER_CST
1536 && INTEGRAL_TYPE_P (TREE_TYPE (rhs
)))
1538 if (wi::eq_p (wi::to_wide (rhs
), wi::min_value (TREE_TYPE (rhs
))))
1540 cmp
= (cmp
== EQ_EXPR
) ? LT_EXPR
: GE_EXPR
;
1541 rhs
= wide_int_to_tree (TREE_TYPE (rhs
),
1542 wi::min_value (TREE_TYPE (rhs
)) + 1);
1544 else if (wi::eq_p (wi::to_wide (rhs
), wi::max_value (TREE_TYPE (rhs
))))
1546 cmp
= (cmp
== EQ_EXPR
) ? GT_EXPR
: LE_EXPR
;
1547 rhs
= wide_int_to_tree (TREE_TYPE (rhs
),
1548 wi::max_value (TREE_TYPE (rhs
)) - 1);
1552 /* This transformation is only valid for order comparisons. Record which
1553 operand is smaller/larger if the result of the comparison is true. */
1554 tree alt_smaller
= NULL_TREE
;
1555 tree alt_larger
= NULL_TREE
;
1556 if (cmp
== LT_EXPR
|| cmp
== LE_EXPR
)
1558 smaller
= gimple_cond_lhs (cond
);
1560 /* If we have smaller < CST it is equivalent to smaller <= CST-1.
1561 Likewise smaller <= CST is equivalent to smaller < CST+1. */
1562 if (TREE_CODE (larger
) == INTEGER_CST
1563 && INTEGRAL_TYPE_P (TREE_TYPE (larger
)))
1567 wi::overflow_type overflow
;
1568 wide_int alt
= wi::sub (wi::to_wide (larger
), 1,
1569 TYPE_SIGN (TREE_TYPE (larger
)),
1572 alt_larger
= wide_int_to_tree (TREE_TYPE (larger
), alt
);
1576 wi::overflow_type overflow
;
1577 wide_int alt
= wi::add (wi::to_wide (larger
), 1,
1578 TYPE_SIGN (TREE_TYPE (larger
)),
1581 alt_larger
= wide_int_to_tree (TREE_TYPE (larger
), alt
);
1585 else if (cmp
== GT_EXPR
|| cmp
== GE_EXPR
)
1588 larger
= gimple_cond_lhs (cond
);
1589 /* If we have larger > CST it is equivalent to larger >= CST+1.
1590 Likewise larger >= CST is equivalent to larger > CST-1. */
1591 if (TREE_CODE (smaller
) == INTEGER_CST
1592 && INTEGRAL_TYPE_P (TREE_TYPE (smaller
)))
1594 wi::overflow_type overflow
;
1597 wide_int alt
= wi::add (wi::to_wide (smaller
), 1,
1598 TYPE_SIGN (TREE_TYPE (smaller
)),
1601 alt_smaller
= wide_int_to_tree (TREE_TYPE (smaller
), alt
);
1605 wide_int alt
= wi::sub (wi::to_wide (smaller
), 1,
1606 TYPE_SIGN (TREE_TYPE (smaller
)),
1609 alt_smaller
= wide_int_to_tree (TREE_TYPE (smaller
), alt
);
1616 /* Handle the special case of (signed_type)x < 0 being equivalent
1617 to x > MAX_VAL(signed_type) and (signed_type)x >= 0 equivalent
1618 to x <= MAX_VAL(signed_type). */
1619 if ((cmp
== GE_EXPR
|| cmp
== LT_EXPR
)
1620 && INTEGRAL_TYPE_P (type
)
1621 && TYPE_UNSIGNED (type
)
1622 && integer_zerop (rhs
))
1624 tree op
= gimple_cond_lhs (cond
);
1625 if (TREE_CODE (op
) == SSA_NAME
1626 && INTEGRAL_TYPE_P (TREE_TYPE (op
))
1627 && !TYPE_UNSIGNED (TREE_TYPE (op
)))
1629 gimple
*def_stmt
= SSA_NAME_DEF_STMT (op
);
1630 if (gimple_assign_cast_p (def_stmt
))
1632 tree op1
= gimple_assign_rhs1 (def_stmt
);
1633 if (INTEGRAL_TYPE_P (TREE_TYPE (op1
))
1634 && TYPE_UNSIGNED (TREE_TYPE (op1
))
1635 && (TYPE_PRECISION (TREE_TYPE (op
))
1636 == TYPE_PRECISION (TREE_TYPE (op1
)))
1637 && useless_type_conversion_p (type
, TREE_TYPE (op1
)))
1639 wide_int w1
= wi::max_value (TREE_TYPE (op
));
1640 wide_int w2
= wi::add (w1
, 1);
1644 smaller
= wide_int_to_tree (TREE_TYPE (op1
), w1
);
1645 alt_smaller
= wide_int_to_tree (TREE_TYPE (op1
), w2
);
1646 alt_larger
= NULL_TREE
;
1651 larger
= wide_int_to_tree (TREE_TYPE (op1
), w1
);
1652 alt_larger
= wide_int_to_tree (TREE_TYPE (op1
), w2
);
1653 alt_smaller
= NULL_TREE
;
1660 /* We need to know which is the true edge and which is the false
1661 edge so that we know if have abs or negative abs. */
1662 extract_true_false_edges_from_block (cond_bb
, &true_edge
, &false_edge
);
1664 /* Forward the edges over the middle basic block. */
1665 if (true_edge
->dest
== middle_bb
)
1666 true_edge
= EDGE_SUCC (true_edge
->dest
, 0);
1667 if (false_edge
->dest
== middle_bb
)
1668 false_edge
= EDGE_SUCC (false_edge
->dest
, 0);
1670 if (true_edge
== e0
)
1672 gcc_assert (false_edge
== e1
);
1678 gcc_assert (false_edge
== e0
);
1679 gcc_assert (true_edge
== e1
);
1684 if (empty_block_p (middle_bb
))
1686 if ((operand_equal_for_phi_arg_p (arg_true
, smaller
)
1688 && operand_equal_for_phi_arg_p (arg_true
, alt_smaller
)))
1689 && (operand_equal_for_phi_arg_p (arg_false
, larger
)
1691 && operand_equal_for_phi_arg_p (arg_true
, alt_larger
))))
1695 if (smaller < larger)
1701 else if ((operand_equal_for_phi_arg_p (arg_false
, smaller
)
1703 && operand_equal_for_phi_arg_p (arg_false
, alt_smaller
)))
1704 && (operand_equal_for_phi_arg_p (arg_true
, larger
)
1706 && operand_equal_for_phi_arg_p (arg_true
, alt_larger
))))
1713 /* Recognize the following case, assuming d <= u:
1719 This is equivalent to
1724 gimple
*assign
= last_and_only_stmt (middle_bb
);
1725 tree lhs
, op0
, op1
, bound
;
1728 || gimple_code (assign
) != GIMPLE_ASSIGN
)
1731 lhs
= gimple_assign_lhs (assign
);
1732 ass_code
= gimple_assign_rhs_code (assign
);
1733 if (ass_code
!= MAX_EXPR
&& ass_code
!= MIN_EXPR
)
1735 op0
= gimple_assign_rhs1 (assign
);
1736 op1
= gimple_assign_rhs2 (assign
);
1738 if (true_edge
->src
== middle_bb
)
1740 /* We got here if the condition is true, i.e., SMALLER < LARGER. */
1741 if (!operand_equal_for_phi_arg_p (lhs
, arg_true
))
1744 if (operand_equal_for_phi_arg_p (arg_false
, larger
)
1746 && operand_equal_for_phi_arg_p (arg_false
, alt_larger
)))
1750 if (smaller < larger)
1752 r' = MAX_EXPR (smaller, bound)
1754 r = PHI <r', larger> --> to be turned to MIN_EXPR. */
1755 if (ass_code
!= MAX_EXPR
)
1759 if (operand_equal_for_phi_arg_p (op0
, smaller
)
1761 && operand_equal_for_phi_arg_p (op0
, alt_smaller
)))
1763 else if (operand_equal_for_phi_arg_p (op1
, smaller
)
1765 && operand_equal_for_phi_arg_p (op1
, alt_smaller
)))
1770 /* We need BOUND <= LARGER. */
1771 if (!integer_nonzerop (fold_build2 (LE_EXPR
, boolean_type_node
,
1775 else if (operand_equal_for_phi_arg_p (arg_false
, smaller
)
1777 && operand_equal_for_phi_arg_p (arg_false
, alt_smaller
)))
1781 if (smaller < larger)
1783 r' = MIN_EXPR (larger, bound)
1785 r = PHI <r', smaller> --> to be turned to MAX_EXPR. */
1786 if (ass_code
!= MIN_EXPR
)
1790 if (operand_equal_for_phi_arg_p (op0
, larger
)
1792 && operand_equal_for_phi_arg_p (op0
, alt_larger
)))
1794 else if (operand_equal_for_phi_arg_p (op1
, larger
)
1796 && operand_equal_for_phi_arg_p (op1
, alt_larger
)))
1801 /* We need BOUND >= SMALLER. */
1802 if (!integer_nonzerop (fold_build2 (GE_EXPR
, boolean_type_node
,
1811 /* We got here if the condition is false, i.e., SMALLER > LARGER. */
1812 if (!operand_equal_for_phi_arg_p (lhs
, arg_false
))
1815 if (operand_equal_for_phi_arg_p (arg_true
, larger
)
1817 && operand_equal_for_phi_arg_p (arg_true
, alt_larger
)))
1821 if (smaller > larger)
1823 r' = MIN_EXPR (smaller, bound)
1825 r = PHI <r', larger> --> to be turned to MAX_EXPR. */
1826 if (ass_code
!= MIN_EXPR
)
1830 if (operand_equal_for_phi_arg_p (op0
, smaller
)
1832 && operand_equal_for_phi_arg_p (op0
, alt_smaller
)))
1834 else if (operand_equal_for_phi_arg_p (op1
, smaller
)
1836 && operand_equal_for_phi_arg_p (op1
, alt_smaller
)))
1841 /* We need BOUND >= LARGER. */
1842 if (!integer_nonzerop (fold_build2 (GE_EXPR
, boolean_type_node
,
1846 else if (operand_equal_for_phi_arg_p (arg_true
, smaller
)
1848 && operand_equal_for_phi_arg_p (arg_true
, alt_smaller
)))
1852 if (smaller > larger)
1854 r' = MAX_EXPR (larger, bound)
1856 r = PHI <r', smaller> --> to be turned to MIN_EXPR. */
1857 if (ass_code
!= MAX_EXPR
)
1861 if (operand_equal_for_phi_arg_p (op0
, larger
))
1863 else if (operand_equal_for_phi_arg_p (op1
, larger
))
1868 /* We need BOUND <= SMALLER. */
1869 if (!integer_nonzerop (fold_build2 (LE_EXPR
, boolean_type_node
,
1877 /* Move the statement from the middle block. */
1878 gsi
= gsi_last_bb (cond_bb
);
1879 gsi_from
= gsi_last_nondebug_bb (middle_bb
);
1880 reset_flow_sensitive_info (SINGLE_SSA_TREE_OPERAND (gsi_stmt (gsi_from
),
1882 gsi_move_before (&gsi_from
, &gsi
);
1885 /* Emit the statement to compute min/max. */
1886 gimple_seq stmts
= NULL
;
1887 tree phi_result
= PHI_RESULT (phi
);
1888 result
= gimple_build (&stmts
, minmax
, TREE_TYPE (phi_result
), arg0
, arg1
);
1890 gsi
= gsi_last_bb (cond_bb
);
1891 gsi_insert_seq_before (&gsi
, stmts
, GSI_NEW_STMT
);
1893 replace_phi_edge_with_variable (cond_bb
, e1
, phi
, result
);
1898 /* Return true if the only executable statement in BB is a GIMPLE_COND. */
1901 cond_only_block_p (basic_block bb
)
1903 /* BB must have no executable statements. */
1904 gimple_stmt_iterator gsi
= gsi_after_labels (bb
);
1907 while (!gsi_end_p (gsi
))
1909 gimple
*stmt
= gsi_stmt (gsi
);
1910 if (is_gimple_debug (stmt
))
1912 else if (gimple_code (stmt
) == GIMPLE_NOP
1913 || gimple_code (stmt
) == GIMPLE_PREDICT
1914 || gimple_code (stmt
) == GIMPLE_COND
)
1923 /* Attempt to optimize (x <=> y) cmp 0 and similar comparisons.
1924 For strong ordering <=> try to match something like:
1925 <bb 2> : // cond3_bb (== cond2_bb)
1926 if (x_4(D) != y_5(D))
1932 if (x_4(D) < y_5(D))
1937 <bb 4> : // middle_bb
1940 # iftmp.0_2 = PHI <1(4), 0(2), -1(3)>
1941 _1 = iftmp.0_2 == 0;
1943 and for partial ordering <=> something like:
1945 <bb 2> : // cond3_bb
1946 if (a_3(D) == b_5(D))
1947 goto <bb 6>; [50.00%]
1949 goto <bb 3>; [50.00%]
1951 <bb 3> [local count: 536870913]: // cond2_bb
1952 if (a_3(D) < b_5(D))
1953 goto <bb 6>; [50.00%]
1955 goto <bb 4>; [50.00%]
1957 <bb 4> [local count: 268435456]: // cond_bb
1958 if (a_3(D) > b_5(D))
1959 goto <bb 6>; [50.00%]
1961 goto <bb 5>; [50.00%]
1963 <bb 5> [local count: 134217728]: // middle_bb
1965 <bb 6> [local count: 1073741824]: // phi_bb
1966 # SR.27_4 = PHI <0(2), -1(3), 1(4), 2(5)>
1967 _2 = SR.27_4 > 0; */
1970 spaceship_replacement (basic_block cond_bb
, basic_block middle_bb
,
1971 edge e0
, edge e1
, gphi
*phi
,
1972 tree arg0
, tree arg1
)
1974 tree phires
= PHI_RESULT (phi
);
1975 if (!INTEGRAL_TYPE_P (TREE_TYPE (phires
))
1976 || TYPE_UNSIGNED (TREE_TYPE (phires
))
1977 || !tree_fits_shwi_p (arg0
)
1978 || !tree_fits_shwi_p (arg1
)
1979 || !IN_RANGE (tree_to_shwi (arg0
), -1, 2)
1980 || !IN_RANGE (tree_to_shwi (arg1
), -1, 2))
1983 basic_block phi_bb
= gimple_bb (phi
);
1984 gcc_assert (phi_bb
== e0
->dest
&& phi_bb
== e1
->dest
);
1985 if (!IN_RANGE (EDGE_COUNT (phi_bb
->preds
), 3, 4))
1988 use_operand_p use_p
;
1990 if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (phires
))
1992 if (!single_imm_use (phires
, &use_p
, &use_stmt
))
1996 gimple
*orig_use_stmt
= use_stmt
;
1997 tree orig_use_lhs
= NULL_TREE
;
1998 int prec
= TYPE_PRECISION (TREE_TYPE (phires
));
1999 if (is_gimple_assign (use_stmt
)
2000 && gimple_assign_rhs_code (use_stmt
) == BIT_AND_EXPR
2001 && TREE_CODE (gimple_assign_rhs2 (use_stmt
)) == INTEGER_CST
2002 && (wi::to_wide (gimple_assign_rhs2 (use_stmt
))
2003 == wi::shifted_mask (1, prec
- 1, false, prec
)))
2005 /* For partial_ordering result operator>= with unspec as second
2006 argument is (res & 1) == res, folded by match.pd into
2008 orig_use_lhs
= gimple_assign_lhs (use_stmt
);
2009 if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (orig_use_lhs
))
2011 if (EDGE_COUNT (phi_bb
->preds
) != 4)
2013 if (!single_imm_use (orig_use_lhs
, &use_p
, &use_stmt
))
2016 if (gimple_code (use_stmt
) == GIMPLE_COND
)
2018 cmp
= gimple_cond_code (use_stmt
);
2019 lhs
= gimple_cond_lhs (use_stmt
);
2020 rhs
= gimple_cond_rhs (use_stmt
);
2022 else if (is_gimple_assign (use_stmt
))
2024 if (gimple_assign_rhs_class (use_stmt
) == GIMPLE_BINARY_RHS
)
2026 cmp
= gimple_assign_rhs_code (use_stmt
);
2027 lhs
= gimple_assign_rhs1 (use_stmt
);
2028 rhs
= gimple_assign_rhs2 (use_stmt
);
2030 else if (gimple_assign_rhs_code (use_stmt
) == COND_EXPR
)
2032 tree cond
= gimple_assign_rhs1 (use_stmt
);
2033 if (!COMPARISON_CLASS_P (cond
))
2035 cmp
= TREE_CODE (cond
);
2036 lhs
= TREE_OPERAND (cond
, 0);
2037 rhs
= TREE_OPERAND (cond
, 1);
2056 if (lhs
!= (orig_use_lhs
? orig_use_lhs
: phires
)
2057 || !tree_fits_shwi_p (rhs
)
2058 || !IN_RANGE (tree_to_shwi (rhs
), -1, 1))
2062 if ((cmp
!= EQ_EXPR
&& cmp
!= NE_EXPR
) || !integer_zerop (rhs
))
2064 /* As for -ffast-math we assume the 2 return to be
2065 impossible, canonicalize (res & ~1) == 0 into
2066 res >= 0 and (res & ~1) != 0 as res < 0. */
2067 cmp
= cmp
== EQ_EXPR
? GE_EXPR
: LT_EXPR
;
2070 if (!empty_block_p (middle_bb
))
2073 gcond
*cond1
= as_a
<gcond
*> (last_stmt (cond_bb
));
2074 enum tree_code cmp1
= gimple_cond_code (cond1
);
2085 tree lhs1
= gimple_cond_lhs (cond1
);
2086 tree rhs1
= gimple_cond_rhs (cond1
);
2087 /* The optimization may be unsafe due to NaNs. */
2088 if (HONOR_NANS (TREE_TYPE (lhs1
)))
2090 if (TREE_CODE (lhs1
) == SSA_NAME
&& SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs1
))
2092 if (TREE_CODE (rhs1
) == SSA_NAME
&& SSA_NAME_OCCURS_IN_ABNORMAL_PHI (rhs1
))
2095 if (!single_pred_p (cond_bb
) || !cond_only_block_p (cond_bb
))
2098 basic_block cond2_bb
= single_pred (cond_bb
);
2099 if (EDGE_COUNT (cond2_bb
->succs
) != 2)
2101 edge cond2_phi_edge
;
2102 if (EDGE_SUCC (cond2_bb
, 0)->dest
== cond_bb
)
2104 if (EDGE_SUCC (cond2_bb
, 1)->dest
!= phi_bb
)
2106 cond2_phi_edge
= EDGE_SUCC (cond2_bb
, 1);
2108 else if (EDGE_SUCC (cond2_bb
, 0)->dest
!= phi_bb
)
2111 cond2_phi_edge
= EDGE_SUCC (cond2_bb
, 0);
2112 tree arg2
= gimple_phi_arg_def (phi
, cond2_phi_edge
->dest_idx
);
2113 if (!tree_fits_shwi_p (arg2
))
2115 gimple
*cond2
= last_stmt (cond2_bb
);
2116 if (cond2
== NULL
|| gimple_code (cond2
) != GIMPLE_COND
)
2118 enum tree_code cmp2
= gimple_cond_code (cond2
);
2119 tree lhs2
= gimple_cond_lhs (cond2
);
2120 tree rhs2
= gimple_cond_rhs (cond2
);
2123 if (!operand_equal_p (rhs2
, rhs1
, 0))
2125 if ((cmp2
== EQ_EXPR
|| cmp2
== NE_EXPR
)
2126 && TREE_CODE (rhs1
) == INTEGER_CST
2127 && TREE_CODE (rhs2
) == INTEGER_CST
)
2129 /* For integers, we can have cond2 x == 5
2130 and cond1 x < 5, x <= 4, x <= 5, x < 6,
2131 x > 5, x >= 6, x >= 5 or x > 4. */
2132 if (tree_int_cst_lt (rhs1
, rhs2
))
2134 if (wi::ne_p (wi::to_wide (rhs1
) + 1, wi::to_wide (rhs2
)))
2136 if (cmp1
== LE_EXPR
)
2138 else if (cmp1
== GT_EXPR
)
2145 gcc_checking_assert (tree_int_cst_lt (rhs2
, rhs1
));
2146 if (wi::ne_p (wi::to_wide (rhs2
) + 1, wi::to_wide (rhs1
)))
2148 if (cmp1
== LT_EXPR
)
2150 else if (cmp1
== GE_EXPR
)
2161 else if (lhs2
== rhs1
)
2170 basic_block cond3_bb
= cond2_bb
;
2171 edge cond3_phi_edge
= cond2_phi_edge
;
2172 gimple
*cond3
= cond2
;
2173 enum tree_code cmp3
= cmp2
;
2176 if (EDGE_COUNT (phi_bb
->preds
) == 4)
2178 if (absu_hwi (tree_to_shwi (arg2
)) != 1)
2180 if (e1
->flags
& EDGE_TRUE_VALUE
)
2182 if (tree_to_shwi (arg0
) != 2
2183 || absu_hwi (tree_to_shwi (arg1
)) != 1
2184 || wi::to_widest (arg1
) == wi::to_widest (arg2
))
2187 else if (tree_to_shwi (arg1
) != 2
2188 || absu_hwi (tree_to_shwi (arg0
)) != 1
2189 || wi::to_widest (arg0
) == wi::to_widest (arg1
))
2201 /* if (x < y) goto phi_bb; else fallthru;
2202 if (x > y) goto phi_bb; else fallthru;
2205 is ok, but if x and y are swapped in one of the comparisons,
2206 or the comparisons are the same and operands not swapped,
2207 or the true and false edges are swapped, it is not. */
2209 ^ (((cond2_phi_edge
->flags
2210 & ((cmp2
== LT_EXPR
|| cmp2
== LE_EXPR
)
2211 ? EDGE_TRUE_VALUE
: EDGE_FALSE_VALUE
)) != 0)
2213 & ((cmp1
== LT_EXPR
|| cmp1
== LE_EXPR
)
2214 ? EDGE_TRUE_VALUE
: EDGE_FALSE_VALUE
)) != 0)))
2216 if (!single_pred_p (cond2_bb
) || !cond_only_block_p (cond2_bb
))
2218 cond3_bb
= single_pred (cond2_bb
);
2219 if (EDGE_COUNT (cond2_bb
->succs
) != 2)
2221 if (EDGE_SUCC (cond3_bb
, 0)->dest
== cond2_bb
)
2223 if (EDGE_SUCC (cond3_bb
, 1)->dest
!= phi_bb
)
2225 cond3_phi_edge
= EDGE_SUCC (cond3_bb
, 1);
2227 else if (EDGE_SUCC (cond3_bb
, 0)->dest
!= phi_bb
)
2230 cond3_phi_edge
= EDGE_SUCC (cond3_bb
, 0);
2231 arg3
= gimple_phi_arg_def (phi
, cond3_phi_edge
->dest_idx
);
2232 cond3
= last_stmt (cond3_bb
);
2233 if (cond3
== NULL
|| gimple_code (cond3
) != GIMPLE_COND
)
2235 cmp3
= gimple_cond_code (cond3
);
2236 lhs3
= gimple_cond_lhs (cond3
);
2237 rhs3
= gimple_cond_rhs (cond3
);
2240 if (!operand_equal_p (rhs3
, rhs1
, 0))
2243 else if (lhs3
== rhs1
)
2251 else if (absu_hwi (tree_to_shwi (arg0
)) != 1
2252 || absu_hwi (tree_to_shwi (arg1
)) != 1
2253 || wi::to_widest (arg0
) == wi::to_widest (arg1
))
2256 if (!integer_zerop (arg3
) || (cmp3
!= EQ_EXPR
&& cmp3
!= NE_EXPR
))
2258 if ((cond3_phi_edge
->flags
& (cmp3
== EQ_EXPR
2259 ? EDGE_TRUE_VALUE
: EDGE_FALSE_VALUE
)) == 0)
2262 /* lhs1 one_cmp rhs1 results in phires of 1. */
2263 enum tree_code one_cmp
;
2264 if ((cmp1
== LT_EXPR
|| cmp1
== LE_EXPR
)
2265 ^ (!integer_onep ((e1
->flags
& EDGE_TRUE_VALUE
) ? arg1
: arg0
)))
2270 enum tree_code res_cmp
;
2274 if (integer_zerop (rhs
))
2276 else if (integer_minus_onep (rhs
))
2277 res_cmp
= one_cmp
== LT_EXPR
? GT_EXPR
: LT_EXPR
;
2278 else if (integer_onep (rhs
))
2284 if (integer_zerop (rhs
))
2286 else if (integer_minus_onep (rhs
))
2287 res_cmp
= one_cmp
== LT_EXPR
? LE_EXPR
: GE_EXPR
;
2288 else if (integer_onep (rhs
))
2289 res_cmp
= one_cmp
== LT_EXPR
? GE_EXPR
: LE_EXPR
;
2294 if (integer_onep (rhs
))
2295 res_cmp
= one_cmp
== LT_EXPR
? GE_EXPR
: LE_EXPR
;
2296 else if (integer_zerop (rhs
))
2297 res_cmp
= one_cmp
== LT_EXPR
? GT_EXPR
: LT_EXPR
;
2302 if (integer_zerop (rhs
))
2303 res_cmp
= one_cmp
== LT_EXPR
? GE_EXPR
: LE_EXPR
;
2304 else if (integer_minus_onep (rhs
))
2305 res_cmp
= one_cmp
== LT_EXPR
? GT_EXPR
: LT_EXPR
;
2310 if (integer_minus_onep (rhs
))
2311 res_cmp
= one_cmp
== LT_EXPR
? LE_EXPR
: GE_EXPR
;
2312 else if (integer_zerop (rhs
))
2318 if (integer_zerop (rhs
))
2319 res_cmp
= one_cmp
== LT_EXPR
? LE_EXPR
: GE_EXPR
;
2320 else if (integer_onep (rhs
))
2329 if (gimple_code (use_stmt
) == GIMPLE_COND
)
2331 gcond
*use_cond
= as_a
<gcond
*> (use_stmt
);
2332 gimple_cond_set_code (use_cond
, res_cmp
);
2333 gimple_cond_set_lhs (use_cond
, lhs1
);
2334 gimple_cond_set_rhs (use_cond
, rhs1
);
2336 else if (gimple_assign_rhs_class (use_stmt
) == GIMPLE_BINARY_RHS
)
2338 gimple_assign_set_rhs_code (use_stmt
, res_cmp
);
2339 gimple_assign_set_rhs1 (use_stmt
, lhs1
);
2340 gimple_assign_set_rhs2 (use_stmt
, rhs1
);
2344 tree cond
= build2 (res_cmp
, TREE_TYPE (gimple_assign_rhs1 (use_stmt
)),
2346 gimple_assign_set_rhs1 (use_stmt
, cond
);
2348 update_stmt (use_stmt
);
2350 if (MAY_HAVE_DEBUG_BIND_STMTS
)
2352 use_operand_p use_p
;
2353 imm_use_iterator iter
;
2354 bool has_debug_uses
= false;
2355 FOR_EACH_IMM_USE_FAST (use_p
, iter
, phires
)
2357 gimple
*use_stmt
= USE_STMT (use_p
);
2358 if (orig_use_lhs
&& use_stmt
== orig_use_stmt
)
2360 gcc_assert (is_gimple_debug (use_stmt
));
2361 has_debug_uses
= true;
2366 if (!has_debug_uses
)
2367 FOR_EACH_IMM_USE_FAST (use_p
, iter
, orig_use_lhs
)
2369 gimple
*use_stmt
= USE_STMT (use_p
);
2370 gcc_assert (is_gimple_debug (use_stmt
));
2371 has_debug_uses
= true;
2373 gimple_stmt_iterator gsi
= gsi_for_stmt (orig_use_stmt
);
2374 tree zero
= build_zero_cst (TREE_TYPE (orig_use_lhs
));
2375 gimple_assign_set_rhs_with_ops (&gsi
, INTEGER_CST
, zero
);
2376 update_stmt (orig_use_stmt
);
2381 /* If there are debug uses, emit something like:
2382 # DEBUG D#1 => i_2(D) > j_3(D) ? 1 : -1
2383 # DEBUG D#2 => i_2(D) == j_3(D) ? 0 : D#1
2384 where > stands for the comparison that yielded 1
2385 and replace debug uses of phi result with that D#2.
2386 Ignore the value of 2, because if NaNs aren't expected,
2387 all floating point numbers should be comparable. */
2388 gimple_stmt_iterator gsi
= gsi_after_labels (gimple_bb (phi
));
2389 tree type
= TREE_TYPE (phires
);
2390 tree temp1
= make_node (DEBUG_EXPR_DECL
);
2391 DECL_ARTIFICIAL (temp1
) = 1;
2392 TREE_TYPE (temp1
) = type
;
2393 SET_DECL_MODE (temp1
, TYPE_MODE (type
));
2394 tree t
= build2 (one_cmp
, boolean_type_node
, lhs1
, rhs2
);
2395 t
= build3 (COND_EXPR
, type
, t
, build_one_cst (type
),
2396 build_int_cst (type
, -1));
2397 gimple
*g
= gimple_build_debug_bind (temp1
, t
, phi
);
2398 gsi_insert_before (&gsi
, g
, GSI_SAME_STMT
);
2399 tree temp2
= make_node (DEBUG_EXPR_DECL
);
2400 DECL_ARTIFICIAL (temp2
) = 1;
2401 TREE_TYPE (temp2
) = type
;
2402 SET_DECL_MODE (temp2
, TYPE_MODE (type
));
2403 t
= build2 (EQ_EXPR
, boolean_type_node
, lhs1
, rhs2
);
2404 t
= build3 (COND_EXPR
, type
, t
, build_zero_cst (type
), temp1
);
2405 g
= gimple_build_debug_bind (temp2
, t
, phi
);
2406 gsi_insert_before (&gsi
, g
, GSI_SAME_STMT
);
2407 replace_uses_by (phires
, temp2
);
2409 replace_uses_by (orig_use_lhs
, temp2
);
2415 gimple_stmt_iterator gsi
= gsi_for_stmt (orig_use_stmt
);
2416 gsi_remove (&gsi
, true);
2419 gimple_stmt_iterator psi
= gsi_for_stmt (phi
);
2420 remove_phi_node (&psi
, true);
2421 statistics_counter_event (cfun
, "spaceship replacement", 1);
2435 _2 = (unsigned long) b_4(D);
2436 _9 = __builtin_popcountl (_2);
2438 _9 = __builtin_popcountl (b_4(D));
2441 c_12 = PHI <0(2), _9(3)>
2445 _2 = (unsigned long) b_4(D);
2446 _9 = __builtin_popcountl (_2);
2448 _9 = __builtin_popcountl (b_4(D));
2453 Similarly for __builtin_clz or __builtin_ctz if
2454 C?Z_DEFINED_VALUE_AT_ZERO is 2, optab is present and
2455 instead of 0 above it uses the value from that macro. */
2458 cond_removal_in_popcount_clz_ctz_pattern (basic_block cond_bb
,
2459 basic_block middle_bb
,
2460 edge e1
, edge e2
, gphi
*phi
,
2461 tree arg0
, tree arg1
)
2464 gimple_stmt_iterator gsi
, gsi_from
;
2466 gimple
*cast
= NULL
;
2470 _2 = (unsigned long) b_4(D);
2471 _9 = __builtin_popcountl (_2);
2473 _9 = __builtin_popcountl (b_4(D));
2474 are the only stmts in the middle_bb. */
2476 gsi
= gsi_start_nondebug_after_labels_bb (middle_bb
);
2477 if (gsi_end_p (gsi
))
2479 cast
= gsi_stmt (gsi
);
2480 gsi_next_nondebug (&gsi
);
2481 if (!gsi_end_p (gsi
))
2483 call
= gsi_stmt (gsi
);
2484 gsi_next_nondebug (&gsi
);
2485 if (!gsi_end_p (gsi
))
2494 /* Check that we have a popcount/clz/ctz builtin. */
2495 if (!is_gimple_call (call
) || gimple_call_num_args (call
) != 1)
2498 arg
= gimple_call_arg (call
, 0);
2499 lhs
= gimple_get_lhs (call
);
2501 if (lhs
== NULL_TREE
)
2504 combined_fn cfn
= gimple_call_combined_fn (call
);
2505 internal_fn ifn
= IFN_LAST
;
2512 if (INTEGRAL_TYPE_P (TREE_TYPE (arg
)))
2514 tree type
= TREE_TYPE (arg
);
2515 if (direct_internal_fn_supported_p (IFN_CLZ
, type
, OPTIMIZE_FOR_BOTH
)
2516 && CLZ_DEFINED_VALUE_AT_ZERO (SCALAR_INT_TYPE_MODE (type
),
2525 if (INTEGRAL_TYPE_P (TREE_TYPE (arg
)))
2527 tree type
= TREE_TYPE (arg
);
2528 if (direct_internal_fn_supported_p (IFN_CTZ
, type
, OPTIMIZE_FOR_BOTH
)
2529 && CTZ_DEFINED_VALUE_AT_ZERO (SCALAR_INT_TYPE_MODE (type
),
2543 /* We have a cast stmt feeding popcount/clz/ctz builtin. */
2544 /* Check that we have a cast prior to that. */
2545 if (gimple_code (cast
) != GIMPLE_ASSIGN
2546 || !CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (cast
)))
2548 /* Result of the cast stmt is the argument to the builtin. */
2549 if (arg
!= gimple_assign_lhs (cast
))
2551 arg
= gimple_assign_rhs1 (cast
);
2554 cond
= last_stmt (cond_bb
);
2556 /* Cond_bb has a check for b_4 [!=|==] 0 before calling the popcount/clz/ctz
2558 if (gimple_code (cond
) != GIMPLE_COND
2559 || (gimple_cond_code (cond
) != NE_EXPR
2560 && gimple_cond_code (cond
) != EQ_EXPR
)
2561 || !integer_zerop (gimple_cond_rhs (cond
))
2562 || arg
!= gimple_cond_lhs (cond
))
2566 if ((e2
->flags
& EDGE_TRUE_VALUE
2567 && gimple_cond_code (cond
) == NE_EXPR
)
2568 || (e1
->flags
& EDGE_TRUE_VALUE
2569 && gimple_cond_code (cond
) == EQ_EXPR
))
2571 std::swap (arg0
, arg1
);
2575 /* Check PHI arguments. */
2577 || TREE_CODE (arg1
) != INTEGER_CST
2578 || wi::to_wide (arg1
) != val
)
2581 /* And insert the popcount/clz/ctz builtin and cast stmt before the
2583 gsi
= gsi_last_bb (cond_bb
);
2586 gsi_from
= gsi_for_stmt (cast
);
2587 gsi_move_before (&gsi_from
, &gsi
);
2588 reset_flow_sensitive_info (gimple_get_lhs (cast
));
2590 gsi_from
= gsi_for_stmt (call
);
2591 if (ifn
== IFN_LAST
|| gimple_call_internal_p (call
))
2592 gsi_move_before (&gsi_from
, &gsi
);
2595 /* For __builtin_c[lt]z* force .C[LT]Z ifn, because only
2596 the latter is well defined at zero. */
2597 call
= gimple_build_call_internal (ifn
, 1, gimple_call_arg (call
, 0));
2598 gimple_call_set_lhs (call
, lhs
);
2599 gsi_insert_before (&gsi
, call
, GSI_SAME_STMT
);
2600 gsi_remove (&gsi_from
, true);
2602 reset_flow_sensitive_info (lhs
);
2604 /* Now update the PHI and remove unneeded bbs. */
2605 replace_phi_edge_with_variable (cond_bb
, e2
, phi
, lhs
);
2609 /* The function absolute_replacement does the main work of doing the absolute
2610 replacement. Return true if the replacement is done. Otherwise return
2612 bb is the basic block where the replacement is going to be done on. arg0
2613 is argument 0 from the phi. Likewise for arg1. */
2616 abs_replacement (basic_block cond_bb
, basic_block middle_bb
,
2617 edge e0 ATTRIBUTE_UNUSED
, edge e1
,
2618 gphi
*phi
, tree arg0
, tree arg1
)
2623 gimple_stmt_iterator gsi
;
2624 edge true_edge
, false_edge
;
2629 enum tree_code cond_code
;
2631 /* If the type says honor signed zeros we cannot do this
2633 if (HONOR_SIGNED_ZEROS (arg1
))
2636 /* OTHER_BLOCK must have only one executable statement which must have the
2637 form arg0 = -arg1 or arg1 = -arg0. */
2639 assign
= last_and_only_stmt (middle_bb
);
2640 /* If we did not find the proper negation assignment, then we cannot
2645 /* If we got here, then we have found the only executable statement
2646 in OTHER_BLOCK. If it is anything other than arg = -arg1 or
2647 arg1 = -arg0, then we cannot optimize. */
2648 if (gimple_code (assign
) != GIMPLE_ASSIGN
)
2651 lhs
= gimple_assign_lhs (assign
);
2653 if (gimple_assign_rhs_code (assign
) != NEGATE_EXPR
)
2656 rhs
= gimple_assign_rhs1 (assign
);
2658 /* The assignment has to be arg0 = -arg1 or arg1 = -arg0. */
2659 if (!(lhs
== arg0
&& rhs
== arg1
)
2660 && !(lhs
== arg1
&& rhs
== arg0
))
2663 cond
= last_stmt (cond_bb
);
2664 result
= PHI_RESULT (phi
);
2666 /* Only relationals comparing arg[01] against zero are interesting. */
2667 cond_code
= gimple_cond_code (cond
);
2668 if (cond_code
!= GT_EXPR
&& cond_code
!= GE_EXPR
2669 && cond_code
!= LT_EXPR
&& cond_code
!= LE_EXPR
)
2672 /* Make sure the conditional is arg[01] OP y. */
2673 if (gimple_cond_lhs (cond
) != rhs
)
2676 if (FLOAT_TYPE_P (TREE_TYPE (gimple_cond_rhs (cond
)))
2677 ? real_zerop (gimple_cond_rhs (cond
))
2678 : integer_zerop (gimple_cond_rhs (cond
)))
2683 /* We need to know which is the true edge and which is the false
2684 edge so that we know if have abs or negative abs. */
2685 extract_true_false_edges_from_block (cond_bb
, &true_edge
, &false_edge
);
2687 /* For GT_EXPR/GE_EXPR, if the true edge goes to OTHER_BLOCK, then we
2688 will need to negate the result. Similarly for LT_EXPR/LE_EXPR if
2689 the false edge goes to OTHER_BLOCK. */
2690 if (cond_code
== GT_EXPR
|| cond_code
== GE_EXPR
)
2695 if (e
->dest
== middle_bb
)
2700 /* If the code negates only iff positive then make sure to not
2701 introduce undefined behavior when negating or computing the absolute.
2702 ??? We could use range info if present to check for arg1 == INT_MIN. */
2704 && (ANY_INTEGRAL_TYPE_P (TREE_TYPE (arg1
))
2705 && ! TYPE_OVERFLOW_WRAPS (TREE_TYPE (arg1
))))
2708 result
= duplicate_ssa_name (result
, NULL
);
2711 lhs
= make_ssa_name (TREE_TYPE (result
));
2715 /* Build the modify expression with abs expression. */
2716 new_stmt
= gimple_build_assign (lhs
, ABS_EXPR
, rhs
);
2718 gsi
= gsi_last_bb (cond_bb
);
2719 gsi_insert_before (&gsi
, new_stmt
, GSI_NEW_STMT
);
2723 /* Get the right GSI. We want to insert after the recently
2724 added ABS_EXPR statement (which we know is the first statement
2726 new_stmt
= gimple_build_assign (result
, NEGATE_EXPR
, lhs
);
2728 gsi_insert_after (&gsi
, new_stmt
, GSI_NEW_STMT
);
2731 replace_phi_edge_with_variable (cond_bb
, e1
, phi
, result
);
2733 /* Note that we optimized this PHI. */
2737 /* Auxiliary functions to determine the set of memory accesses which
2738 can't trap because they are preceded by accesses to the same memory
2739 portion. We do that for MEM_REFs, so we only need to track
2740 the SSA_NAME of the pointer indirectly referenced. The algorithm
2741 simply is a walk over all instructions in dominator order. When
2742 we see an MEM_REF we determine if we've already seen a same
2743 ref anywhere up to the root of the dominator tree. If we do the
2744 current access can't trap. If we don't see any dominating access
2745 the current access might trap, but might also make later accesses
2746 non-trapping, so we remember it. We need to be careful with loads
2747 or stores, for instance a load might not trap, while a store would,
2748 so if we see a dominating read access this doesn't mean that a later
2749 write access would not trap. Hence we also need to differentiate the
2750 type of access(es) seen.
2752 ??? We currently are very conservative and assume that a load might
2753 trap even if a store doesn't (write-only memory). This probably is
2754 overly conservative.
2756 We currently support a special case that for !TREE_ADDRESSABLE automatic
2757 variables, it could ignore whether something is a load or store because the
2758 local stack should be always writable. */
2760 /* A hash-table of references (MEM_REF/ARRAY_REF/COMPONENT_REF), and in which
2761 basic block an *_REF through it was seen, which would constitute a
2762 no-trap region for same accesses.
2764 Size is needed to support 2 MEM_REFs of different types, like
2765 MEM<double>(s_1) and MEM<long>(s_1), which would compare equal with
2775 /* Hashtable helpers. */
2777 struct refs_hasher
: free_ptr_hash
<ref_to_bb
>
2779 static inline hashval_t
hash (const ref_to_bb
*);
2780 static inline bool equal (const ref_to_bb
*, const ref_to_bb
*);
2783 /* Used for quick clearing of the hash-table when we see calls.
2784 Hash entries with phase < nt_call_phase are invalid. */
2785 static unsigned int nt_call_phase
;
2787 /* The hash function. */
2790 refs_hasher::hash (const ref_to_bb
*n
)
2792 inchash::hash hstate
;
2793 inchash::add_expr (n
->exp
, hstate
, OEP_ADDRESS_OF
);
2794 hstate
.add_hwi (n
->size
);
2795 return hstate
.end ();
2798 /* The equality function of *P1 and *P2. */
2801 refs_hasher::equal (const ref_to_bb
*n1
, const ref_to_bb
*n2
)
2803 return operand_equal_p (n1
->exp
, n2
->exp
, OEP_ADDRESS_OF
)
2804 && n1
->size
== n2
->size
;
2807 class nontrapping_dom_walker
: public dom_walker
2810 nontrapping_dom_walker (cdi_direction direction
, hash_set
<tree
> *ps
)
2811 : dom_walker (direction
), m_nontrapping (ps
), m_seen_refs (128)
2814 virtual edge
before_dom_children (basic_block
);
2815 virtual void after_dom_children (basic_block
);
2819 /* We see the expression EXP in basic block BB. If it's an interesting
2820 expression (an MEM_REF through an SSA_NAME) possibly insert the
2821 expression into the set NONTRAP or the hash table of seen expressions.
2822 STORE is true if this expression is on the LHS, otherwise it's on
2824 void add_or_mark_expr (basic_block
, tree
, bool);
2826 hash_set
<tree
> *m_nontrapping
;
2828 /* The hash table for remembering what we've seen. */
2829 hash_table
<refs_hasher
> m_seen_refs
;
2832 /* Called by walk_dominator_tree, when entering the block BB. */
2834 nontrapping_dom_walker::before_dom_children (basic_block bb
)
2838 gimple_stmt_iterator gsi
;
2840 /* If we haven't seen all our predecessors, clear the hash-table. */
2841 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
2842 if ((((size_t)e
->src
->aux
) & 2) == 0)
2848 /* Mark this BB as being on the path to dominator root and as visited. */
2849 bb
->aux
= (void*)(1 | 2);
2851 /* And walk the statements in order. */
2852 for (gsi
= gsi_start_bb (bb
); !gsi_end_p (gsi
); gsi_next (&gsi
))
2854 gimple
*stmt
= gsi_stmt (gsi
);
2856 if ((gimple_code (stmt
) == GIMPLE_ASM
&& gimple_vdef (stmt
))
2857 || (is_gimple_call (stmt
)
2858 && (!nonfreeing_call_p (stmt
) || !nonbarrier_call_p (stmt
))))
2860 else if (gimple_assign_single_p (stmt
) && !gimple_has_volatile_ops (stmt
))
2862 add_or_mark_expr (bb
, gimple_assign_lhs (stmt
), true);
2863 add_or_mark_expr (bb
, gimple_assign_rhs1 (stmt
), false);
2869 /* Called by walk_dominator_tree, when basic block BB is exited. */
2871 nontrapping_dom_walker::after_dom_children (basic_block bb
)
2873 /* This BB isn't on the path to dominator root anymore. */
2877 /* We see the expression EXP in basic block BB. If it's an interesting
2882 possibly insert the expression into the set NONTRAP or the hash table
2883 of seen expressions. STORE is true if this expression is on the LHS,
2884 otherwise it's on the RHS. */
2886 nontrapping_dom_walker::add_or_mark_expr (basic_block bb
, tree exp
, bool store
)
2890 if ((TREE_CODE (exp
) == MEM_REF
|| TREE_CODE (exp
) == ARRAY_REF
2891 || TREE_CODE (exp
) == COMPONENT_REF
)
2892 && (size
= int_size_in_bytes (TREE_TYPE (exp
))) > 0)
2894 struct ref_to_bb map
;
2896 struct ref_to_bb
*r2bb
;
2897 basic_block found_bb
= 0;
2901 tree base
= get_base_address (exp
);
2902 /* Only record a LOAD of a local variable without address-taken, as
2903 the local stack is always writable. This allows cselim on a STORE
2904 with a dominating LOAD. */
2905 if (!auto_var_p (base
) || TREE_ADDRESSABLE (base
))
2909 /* Try to find the last seen *_REF, which can trap. */
2912 slot
= m_seen_refs
.find_slot (&map
, INSERT
);
2914 if (r2bb
&& r2bb
->phase
>= nt_call_phase
)
2915 found_bb
= r2bb
->bb
;
2917 /* If we've found a trapping *_REF, _and_ it dominates EXP
2918 (it's in a basic block on the path from us to the dominator root)
2919 then we can't trap. */
2920 if (found_bb
&& (((size_t)found_bb
->aux
) & 1) == 1)
2922 m_nontrapping
->add (exp
);
2926 /* EXP might trap, so insert it into the hash table. */
2929 r2bb
->phase
= nt_call_phase
;
2934 r2bb
= XNEW (struct ref_to_bb
);
2935 r2bb
->phase
= nt_call_phase
;
2945 /* This is the entry point of gathering non trapping memory accesses.
2946 It will do a dominator walk over the whole function, and it will
2947 make use of the bb->aux pointers. It returns a set of trees
2948 (the MEM_REFs itself) which can't trap. */
2949 static hash_set
<tree
> *
2950 get_non_trapping (void)
2953 hash_set
<tree
> *nontrap
= new hash_set
<tree
>;
2955 nontrapping_dom_walker (CDI_DOMINATORS
, nontrap
)
2956 .walk (cfun
->cfg
->x_entry_block_ptr
);
2958 clear_aux_for_blocks ();
2962 /* Do the main work of conditional store replacement. We already know
2963 that the recognized pattern looks like so:
2966 if (cond) goto MIDDLE_BB; else goto JOIN_BB (edge E1)
2969 fallthrough (edge E0)
2973 We check that MIDDLE_BB contains only one store, that that store
2974 doesn't trap (not via NOTRAP, but via checking if an access to the same
2975 memory location dominates us, or the store is to a local addressable
2976 object) and that the store has a "simple" RHS. */
2979 cond_store_replacement (basic_block middle_bb
, basic_block join_bb
,
2980 edge e0
, edge e1
, hash_set
<tree
> *nontrap
)
2982 gimple
*assign
= last_and_only_stmt (middle_bb
);
2983 tree lhs
, rhs
, name
, name2
;
2986 gimple_stmt_iterator gsi
;
2989 /* Check if middle_bb contains of only one store. */
2991 || !gimple_assign_single_p (assign
)
2992 || gimple_has_volatile_ops (assign
))
2995 /* And no PHI nodes so all uses in the single stmt are also
2996 available where we insert to. */
2997 if (!gimple_seq_empty_p (phi_nodes (middle_bb
)))
3000 locus
= gimple_location (assign
);
3001 lhs
= gimple_assign_lhs (assign
);
3002 rhs
= gimple_assign_rhs1 (assign
);
3003 if ((!REFERENCE_CLASS_P (lhs
)
3005 || !is_gimple_reg_type (TREE_TYPE (lhs
)))
3008 /* Prove that we can move the store down. We could also check
3009 TREE_THIS_NOTRAP here, but in that case we also could move stores,
3010 whose value is not available readily, which we want to avoid. */
3011 if (!nontrap
->contains (lhs
))
3013 /* If LHS is an access to a local variable without address-taken
3014 (or when we allow data races) and known not to trap, we could
3015 always safely move down the store. */
3016 tree base
= get_base_address (lhs
);
3017 if (!auto_var_p (base
)
3018 || (TREE_ADDRESSABLE (base
) && !flag_store_data_races
)
3019 || tree_could_trap_p (lhs
))
3023 /* Now we've checked the constraints, so do the transformation:
3024 1) Remove the single store. */
3025 gsi
= gsi_for_stmt (assign
);
3026 unlink_stmt_vdef (assign
);
3027 gsi_remove (&gsi
, true);
3028 release_defs (assign
);
3030 /* Make both store and load use alias-set zero as we have to
3031 deal with the case of the store being a conditional change
3032 of the dynamic type. */
3033 lhs
= unshare_expr (lhs
);
3035 while (handled_component_p (*basep
))
3036 basep
= &TREE_OPERAND (*basep
, 0);
3037 if (TREE_CODE (*basep
) == MEM_REF
3038 || TREE_CODE (*basep
) == TARGET_MEM_REF
)
3039 TREE_OPERAND (*basep
, 1)
3040 = fold_convert (ptr_type_node
, TREE_OPERAND (*basep
, 1));
3042 *basep
= build2 (MEM_REF
, TREE_TYPE (*basep
),
3043 build_fold_addr_expr (*basep
),
3044 build_zero_cst (ptr_type_node
));
3046 /* 2) Insert a load from the memory of the store to the temporary
3047 on the edge which did not contain the store. */
3048 name
= make_temp_ssa_name (TREE_TYPE (lhs
), NULL
, "cstore");
3049 new_stmt
= gimple_build_assign (name
, lhs
);
3050 gimple_set_location (new_stmt
, locus
);
3051 lhs
= unshare_expr (lhs
);
3053 /* Set the no-warning bit on the rhs of the load to avoid uninit
3055 tree rhs1
= gimple_assign_rhs1 (new_stmt
);
3056 suppress_warning (rhs1
, OPT_Wuninitialized
);
3058 gsi_insert_on_edge (e1
, new_stmt
);
3060 /* 3) Create a PHI node at the join block, with one argument
3061 holding the old RHS, and the other holding the temporary
3062 where we stored the old memory contents. */
3063 name2
= make_temp_ssa_name (TREE_TYPE (lhs
), NULL
, "cstore");
3064 newphi
= create_phi_node (name2
, join_bb
);
3065 add_phi_arg (newphi
, rhs
, e0
, locus
);
3066 add_phi_arg (newphi
, name
, e1
, locus
);
3068 new_stmt
= gimple_build_assign (lhs
, PHI_RESULT (newphi
));
3070 /* 4) Insert that PHI node. */
3071 gsi
= gsi_after_labels (join_bb
);
3072 if (gsi_end_p (gsi
))
3074 gsi
= gsi_last_bb (join_bb
);
3075 gsi_insert_after (&gsi
, new_stmt
, GSI_NEW_STMT
);
3078 gsi_insert_before (&gsi
, new_stmt
, GSI_NEW_STMT
);
3080 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3082 fprintf (dump_file
, "\nConditional store replacement happened!");
3083 fprintf (dump_file
, "\nReplaced the store with a load.");
3084 fprintf (dump_file
, "\nInserted a new PHI statement in joint block:\n");
3085 print_gimple_stmt (dump_file
, new_stmt
, 0, TDF_VOPS
|TDF_MEMSYMS
);
3087 statistics_counter_event (cfun
, "conditional store replacement", 1);
3092 /* Do the main work of conditional store replacement. */
3095 cond_if_else_store_replacement_1 (basic_block then_bb
, basic_block else_bb
,
3096 basic_block join_bb
, gimple
*then_assign
,
3097 gimple
*else_assign
)
3099 tree lhs_base
, lhs
, then_rhs
, else_rhs
, name
;
3100 location_t then_locus
, else_locus
;
3101 gimple_stmt_iterator gsi
;
3105 if (then_assign
== NULL
3106 || !gimple_assign_single_p (then_assign
)
3107 || gimple_clobber_p (then_assign
)
3108 || gimple_has_volatile_ops (then_assign
)
3109 || else_assign
== NULL
3110 || !gimple_assign_single_p (else_assign
)
3111 || gimple_clobber_p (else_assign
)
3112 || gimple_has_volatile_ops (else_assign
))
3115 lhs
= gimple_assign_lhs (then_assign
);
3116 if (!is_gimple_reg_type (TREE_TYPE (lhs
))
3117 || !operand_equal_p (lhs
, gimple_assign_lhs (else_assign
), 0))
3120 lhs_base
= get_base_address (lhs
);
3121 if (lhs_base
== NULL_TREE
3122 || (!DECL_P (lhs_base
) && TREE_CODE (lhs_base
) != MEM_REF
))
3125 then_rhs
= gimple_assign_rhs1 (then_assign
);
3126 else_rhs
= gimple_assign_rhs1 (else_assign
);
3127 then_locus
= gimple_location (then_assign
);
3128 else_locus
= gimple_location (else_assign
);
3130 /* Now we've checked the constraints, so do the transformation:
3131 1) Remove the stores. */
3132 gsi
= gsi_for_stmt (then_assign
);
3133 unlink_stmt_vdef (then_assign
);
3134 gsi_remove (&gsi
, true);
3135 release_defs (then_assign
);
3137 gsi
= gsi_for_stmt (else_assign
);
3138 unlink_stmt_vdef (else_assign
);
3139 gsi_remove (&gsi
, true);
3140 release_defs (else_assign
);
3142 /* 2) Create a PHI node at the join block, with one argument
3143 holding the old RHS, and the other holding the temporary
3144 where we stored the old memory contents. */
3145 name
= make_temp_ssa_name (TREE_TYPE (lhs
), NULL
, "cstore");
3146 newphi
= create_phi_node (name
, join_bb
);
3147 add_phi_arg (newphi
, then_rhs
, EDGE_SUCC (then_bb
, 0), then_locus
);
3148 add_phi_arg (newphi
, else_rhs
, EDGE_SUCC (else_bb
, 0), else_locus
);
3150 new_stmt
= gimple_build_assign (lhs
, PHI_RESULT (newphi
));
3152 /* 3) Insert that PHI node. */
3153 gsi
= gsi_after_labels (join_bb
);
3154 if (gsi_end_p (gsi
))
3156 gsi
= gsi_last_bb (join_bb
);
3157 gsi_insert_after (&gsi
, new_stmt
, GSI_NEW_STMT
);
3160 gsi_insert_before (&gsi
, new_stmt
, GSI_NEW_STMT
);
3162 statistics_counter_event (cfun
, "if-then-else store replacement", 1);
3167 /* Return the single store in BB with VDEF or NULL if there are
3168 other stores in the BB or loads following the store. */
3171 single_trailing_store_in_bb (basic_block bb
, tree vdef
)
3173 if (SSA_NAME_IS_DEFAULT_DEF (vdef
))
3175 gimple
*store
= SSA_NAME_DEF_STMT (vdef
);
3176 if (gimple_bb (store
) != bb
3177 || gimple_code (store
) == GIMPLE_PHI
)
3180 /* Verify there is no other store in this BB. */
3181 if (!SSA_NAME_IS_DEFAULT_DEF (gimple_vuse (store
))
3182 && gimple_bb (SSA_NAME_DEF_STMT (gimple_vuse (store
))) == bb
3183 && gimple_code (SSA_NAME_DEF_STMT (gimple_vuse (store
))) != GIMPLE_PHI
)
3186 /* Verify there is no load or store after the store. */
3187 use_operand_p use_p
;
3188 imm_use_iterator imm_iter
;
3189 FOR_EACH_IMM_USE_FAST (use_p
, imm_iter
, gimple_vdef (store
))
3190 if (USE_STMT (use_p
) != store
3191 && gimple_bb (USE_STMT (use_p
)) == bb
)
3197 /* Conditional store replacement. We already know
3198 that the recognized pattern looks like so:
3201 if (cond) goto THEN_BB; else goto ELSE_BB (edge E1)
3211 fallthrough (edge E0)
3215 We check that it is safe to sink the store to JOIN_BB by verifying that
3216 there are no read-after-write or write-after-write dependencies in
3217 THEN_BB and ELSE_BB. */
3220 cond_if_else_store_replacement (basic_block then_bb
, basic_block else_bb
,
3221 basic_block join_bb
)
3223 vec
<data_reference_p
> then_datarefs
, else_datarefs
;
3224 vec
<ddr_p
> then_ddrs
, else_ddrs
;
3225 gimple
*then_store
, *else_store
;
3226 bool found
, ok
= false, res
;
3227 struct data_dependence_relation
*ddr
;
3228 data_reference_p then_dr
, else_dr
;
3230 tree then_lhs
, else_lhs
;
3231 basic_block blocks
[3];
3233 /* Handle the case with single store in THEN_BB and ELSE_BB. That is
3234 cheap enough to always handle as it allows us to elide dependence
3237 for (gphi_iterator si
= gsi_start_phis (join_bb
); !gsi_end_p (si
);
3239 if (virtual_operand_p (gimple_phi_result (si
.phi ())))
3246 tree then_vdef
= PHI_ARG_DEF_FROM_EDGE (vphi
, single_succ_edge (then_bb
));
3247 tree else_vdef
= PHI_ARG_DEF_FROM_EDGE (vphi
, single_succ_edge (else_bb
));
3248 gimple
*then_assign
= single_trailing_store_in_bb (then_bb
, then_vdef
);
3251 gimple
*else_assign
= single_trailing_store_in_bb (else_bb
, else_vdef
);
3253 return cond_if_else_store_replacement_1 (then_bb
, else_bb
, join_bb
,
3254 then_assign
, else_assign
);
3257 /* If either vectorization or if-conversion is disabled then do
3258 not sink any stores. */
3259 if (param_max_stores_to_sink
== 0
3260 || (!flag_tree_loop_vectorize
&& !flag_tree_slp_vectorize
)
3261 || !flag_tree_loop_if_convert
)
3264 /* Find data references. */
3265 then_datarefs
.create (1);
3266 else_datarefs
.create (1);
3267 if ((find_data_references_in_bb (NULL
, then_bb
, &then_datarefs
)
3269 || !then_datarefs
.length ()
3270 || (find_data_references_in_bb (NULL
, else_bb
, &else_datarefs
)
3272 || !else_datarefs
.length ())
3274 free_data_refs (then_datarefs
);
3275 free_data_refs (else_datarefs
);
3279 /* Find pairs of stores with equal LHS. */
3280 auto_vec
<gimple
*, 1> then_stores
, else_stores
;
3281 FOR_EACH_VEC_ELT (then_datarefs
, i
, then_dr
)
3283 if (DR_IS_READ (then_dr
))
3286 then_store
= DR_STMT (then_dr
);
3287 then_lhs
= gimple_get_lhs (then_store
);
3288 if (then_lhs
== NULL_TREE
)
3292 FOR_EACH_VEC_ELT (else_datarefs
, j
, else_dr
)
3294 if (DR_IS_READ (else_dr
))
3297 else_store
= DR_STMT (else_dr
);
3298 else_lhs
= gimple_get_lhs (else_store
);
3299 if (else_lhs
== NULL_TREE
)
3302 if (operand_equal_p (then_lhs
, else_lhs
, 0))
3312 then_stores
.safe_push (then_store
);
3313 else_stores
.safe_push (else_store
);
3316 /* No pairs of stores found. */
3317 if (!then_stores
.length ()
3318 || then_stores
.length () > (unsigned) param_max_stores_to_sink
)
3320 free_data_refs (then_datarefs
);
3321 free_data_refs (else_datarefs
);
3325 /* Compute and check data dependencies in both basic blocks. */
3326 then_ddrs
.create (1);
3327 else_ddrs
.create (1);
3328 if (!compute_all_dependences (then_datarefs
, &then_ddrs
,
3330 || !compute_all_dependences (else_datarefs
, &else_ddrs
,
3333 free_dependence_relations (then_ddrs
);
3334 free_dependence_relations (else_ddrs
);
3335 free_data_refs (then_datarefs
);
3336 free_data_refs (else_datarefs
);
3339 blocks
[0] = then_bb
;
3340 blocks
[1] = else_bb
;
3341 blocks
[2] = join_bb
;
3342 renumber_gimple_stmt_uids_in_blocks (blocks
, 3);
3344 /* Check that there are no read-after-write or write-after-write dependencies
3346 FOR_EACH_VEC_ELT (then_ddrs
, i
, ddr
)
3348 struct data_reference
*dra
= DDR_A (ddr
);
3349 struct data_reference
*drb
= DDR_B (ddr
);
3351 if (DDR_ARE_DEPENDENT (ddr
) != chrec_known
3352 && ((DR_IS_READ (dra
) && DR_IS_WRITE (drb
)
3353 && gimple_uid (DR_STMT (dra
)) > gimple_uid (DR_STMT (drb
)))
3354 || (DR_IS_READ (drb
) && DR_IS_WRITE (dra
)
3355 && gimple_uid (DR_STMT (drb
)) > gimple_uid (DR_STMT (dra
)))
3356 || (DR_IS_WRITE (dra
) && DR_IS_WRITE (drb
))))
3358 free_dependence_relations (then_ddrs
);
3359 free_dependence_relations (else_ddrs
);
3360 free_data_refs (then_datarefs
);
3361 free_data_refs (else_datarefs
);
3366 /* Check that there are no read-after-write or write-after-write dependencies
3368 FOR_EACH_VEC_ELT (else_ddrs
, i
, ddr
)
3370 struct data_reference
*dra
= DDR_A (ddr
);
3371 struct data_reference
*drb
= DDR_B (ddr
);
3373 if (DDR_ARE_DEPENDENT (ddr
) != chrec_known
3374 && ((DR_IS_READ (dra
) && DR_IS_WRITE (drb
)
3375 && gimple_uid (DR_STMT (dra
)) > gimple_uid (DR_STMT (drb
)))
3376 || (DR_IS_READ (drb
) && DR_IS_WRITE (dra
)
3377 && gimple_uid (DR_STMT (drb
)) > gimple_uid (DR_STMT (dra
)))
3378 || (DR_IS_WRITE (dra
) && DR_IS_WRITE (drb
))))
3380 free_dependence_relations (then_ddrs
);
3381 free_dependence_relations (else_ddrs
);
3382 free_data_refs (then_datarefs
);
3383 free_data_refs (else_datarefs
);
3388 /* Sink stores with same LHS. */
3389 FOR_EACH_VEC_ELT (then_stores
, i
, then_store
)
3391 else_store
= else_stores
[i
];
3392 res
= cond_if_else_store_replacement_1 (then_bb
, else_bb
, join_bb
,
3393 then_store
, else_store
);
3397 free_dependence_relations (then_ddrs
);
3398 free_dependence_relations (else_ddrs
);
3399 free_data_refs (then_datarefs
);
3400 free_data_refs (else_datarefs
);
3405 /* Return TRUE if STMT has a VUSE whose corresponding VDEF is in BB. */
3408 local_mem_dependence (gimple
*stmt
, basic_block bb
)
3410 tree vuse
= gimple_vuse (stmt
);
3416 def
= SSA_NAME_DEF_STMT (vuse
);
3417 return (def
&& gimple_bb (def
) == bb
);
3420 /* Given a "diamond" control-flow pattern where BB0 tests a condition,
3421 BB1 and BB2 are "then" and "else" blocks dependent on this test,
3422 and BB3 rejoins control flow following BB1 and BB2, look for
3423 opportunities to hoist loads as follows. If BB3 contains a PHI of
3424 two loads, one each occurring in BB1 and BB2, and the loads are
3425 provably of adjacent fields in the same structure, then move both
3426 loads into BB0. Of course this can only be done if there are no
3427 dependencies preventing such motion.
3429 One of the hoisted loads will always be speculative, so the
3430 transformation is currently conservative:
3432 - The fields must be strictly adjacent.
3433 - The two fields must occupy a single memory block that is
3434 guaranteed to not cross a page boundary.
3436 The last is difficult to prove, as such memory blocks should be
3437 aligned on the minimum of the stack alignment boundary and the
3438 alignment guaranteed by heap allocation interfaces. Thus we rely
3439 on a parameter for the alignment value.
3441 Provided a good value is used for the last case, the first
3442 restriction could possibly be relaxed. */
3445 hoist_adjacent_loads (basic_block bb0
, basic_block bb1
,
3446 basic_block bb2
, basic_block bb3
)
3448 int param_align
= param_l1_cache_line_size
;
3449 unsigned param_align_bits
= (unsigned) (param_align
* BITS_PER_UNIT
);
3452 /* Walk the phis in bb3 looking for an opportunity. We are looking
3453 for phis of two SSA names, one each of which is defined in bb1 and
3455 for (gsi
= gsi_start_phis (bb3
); !gsi_end_p (gsi
); gsi_next (&gsi
))
3457 gphi
*phi_stmt
= gsi
.phi ();
3458 gimple
*def1
, *def2
;
3459 tree arg1
, arg2
, ref1
, ref2
, field1
, field2
;
3460 tree tree_offset1
, tree_offset2
, tree_size2
, next
;
3461 int offset1
, offset2
, size2
;
3463 gimple_stmt_iterator gsi2
;
3464 basic_block bb_for_def1
, bb_for_def2
;
3466 if (gimple_phi_num_args (phi_stmt
) != 2
3467 || virtual_operand_p (gimple_phi_result (phi_stmt
)))
3470 arg1
= gimple_phi_arg_def (phi_stmt
, 0);
3471 arg2
= gimple_phi_arg_def (phi_stmt
, 1);
3473 if (TREE_CODE (arg1
) != SSA_NAME
3474 || TREE_CODE (arg2
) != SSA_NAME
3475 || SSA_NAME_IS_DEFAULT_DEF (arg1
)
3476 || SSA_NAME_IS_DEFAULT_DEF (arg2
))
3479 def1
= SSA_NAME_DEF_STMT (arg1
);
3480 def2
= SSA_NAME_DEF_STMT (arg2
);
3482 if ((gimple_bb (def1
) != bb1
|| gimple_bb (def2
) != bb2
)
3483 && (gimple_bb (def2
) != bb1
|| gimple_bb (def1
) != bb2
))
3486 /* Check the mode of the arguments to be sure a conditional move
3487 can be generated for it. */
3488 if (optab_handler (movcc_optab
, TYPE_MODE (TREE_TYPE (arg1
)))
3489 == CODE_FOR_nothing
)
3492 /* Both statements must be assignments whose RHS is a COMPONENT_REF. */
3493 if (!gimple_assign_single_p (def1
)
3494 || !gimple_assign_single_p (def2
)
3495 || gimple_has_volatile_ops (def1
)
3496 || gimple_has_volatile_ops (def2
))
3499 ref1
= gimple_assign_rhs1 (def1
);
3500 ref2
= gimple_assign_rhs1 (def2
);
3502 if (TREE_CODE (ref1
) != COMPONENT_REF
3503 || TREE_CODE (ref2
) != COMPONENT_REF
)
3506 /* The zeroth operand of the two component references must be
3507 identical. It is not sufficient to compare get_base_address of
3508 the two references, because this could allow for different
3509 elements of the same array in the two trees. It is not safe to
3510 assume that the existence of one array element implies the
3511 existence of a different one. */
3512 if (!operand_equal_p (TREE_OPERAND (ref1
, 0), TREE_OPERAND (ref2
, 0), 0))
3515 field1
= TREE_OPERAND (ref1
, 1);
3516 field2
= TREE_OPERAND (ref2
, 1);
3518 /* Check for field adjacency, and ensure field1 comes first. */
3519 for (next
= DECL_CHAIN (field1
);
3520 next
&& TREE_CODE (next
) != FIELD_DECL
;
3521 next
= DECL_CHAIN (next
))
3526 for (next
= DECL_CHAIN (field2
);
3527 next
&& TREE_CODE (next
) != FIELD_DECL
;
3528 next
= DECL_CHAIN (next
))
3534 std::swap (field1
, field2
);
3535 std::swap (def1
, def2
);
3538 bb_for_def1
= gimple_bb (def1
);
3539 bb_for_def2
= gimple_bb (def2
);
3541 /* Check for proper alignment of the first field. */
3542 tree_offset1
= bit_position (field1
);
3543 tree_offset2
= bit_position (field2
);
3544 tree_size2
= DECL_SIZE (field2
);
3546 if (!tree_fits_uhwi_p (tree_offset1
)
3547 || !tree_fits_uhwi_p (tree_offset2
)
3548 || !tree_fits_uhwi_p (tree_size2
))
3551 offset1
= tree_to_uhwi (tree_offset1
);
3552 offset2
= tree_to_uhwi (tree_offset2
);
3553 size2
= tree_to_uhwi (tree_size2
);
3554 align1
= DECL_ALIGN (field1
) % param_align_bits
;
3556 if (offset1
% BITS_PER_UNIT
!= 0)
3559 /* For profitability, the two field references should fit within
3560 a single cache line. */
3561 if (align1
+ offset2
- offset1
+ size2
> param_align_bits
)
3564 /* The two expressions cannot be dependent upon vdefs defined
3566 if (local_mem_dependence (def1
, bb_for_def1
)
3567 || local_mem_dependence (def2
, bb_for_def2
))
3570 /* The conditions are satisfied; hoist the loads from bb1 and bb2 into
3571 bb0. We hoist the first one first so that a cache miss is handled
3572 efficiently regardless of hardware cache-fill policy. */
3573 gsi2
= gsi_for_stmt (def1
);
3574 gsi_move_to_bb_end (&gsi2
, bb0
);
3575 gsi2
= gsi_for_stmt (def2
);
3576 gsi_move_to_bb_end (&gsi2
, bb0
);
3577 statistics_counter_event (cfun
, "hoisted loads", 1);
3579 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3582 "\nHoisting adjacent loads from %d and %d into %d: \n",
3583 bb_for_def1
->index
, bb_for_def2
->index
, bb0
->index
);
3584 print_gimple_stmt (dump_file
, def1
, 0, TDF_VOPS
|TDF_MEMSYMS
);
3585 print_gimple_stmt (dump_file
, def2
, 0, TDF_VOPS
|TDF_MEMSYMS
);
3590 /* Determine whether we should attempt to hoist adjacent loads out of
3591 diamond patterns in pass_phiopt. Always hoist loads if
3592 -fhoist-adjacent-loads is specified and the target machine has
3593 both a conditional move instruction and a defined cache line size. */
3596 gate_hoist_loads (void)
3598 return (flag_hoist_adjacent_loads
== 1
3599 && param_l1_cache_line_size
3600 && HAVE_conditional_move
);
3603 /* This pass tries to replaces an if-then-else block with an
3604 assignment. We have four kinds of transformations. Some of these
3605 transformations are also performed by the ifcvt RTL optimizer.
3607 Conditional Replacement
3608 -----------------------
3610 This transformation, implemented in match_simplify_replacement,
3614 if (cond) goto bb2; else goto bb1;
3617 x = PHI <0 (bb1), 1 (bb0), ...>;
3625 x = PHI <x' (bb0), ...>;
3627 We remove bb1 as it becomes unreachable. This occurs often due to
3628 gimplification of conditionals.
3633 This transformation, implemented in value_replacement, replaces
3636 if (a != b) goto bb2; else goto bb1;
3639 x = PHI <a (bb1), b (bb0), ...>;
3645 x = PHI <b (bb0), ...>;
3647 This opportunity can sometimes occur as a result of other
3651 Another case caught by value replacement looks like this:
3657 if (t3 != 0) goto bb1; else goto bb2;
3673 This transformation, implemented in abs_replacement, replaces
3676 if (a >= 0) goto bb2; else goto bb1;
3680 x = PHI <x (bb1), a (bb0), ...>;
3687 x = PHI <x' (bb0), ...>;
3692 This transformation, minmax_replacement replaces
3695 if (a <= b) goto bb2; else goto bb1;
3698 x = PHI <b (bb1), a (bb0), ...>;
3703 x' = MIN_EXPR (a, b)
3705 x = PHI <x' (bb0), ...>;
3707 A similar transformation is done for MAX_EXPR.
3710 This pass also performs a fifth transformation of a slightly different
3713 Factor conversion in COND_EXPR
3714 ------------------------------
3716 This transformation factors the conversion out of COND_EXPR with
3717 factor_out_conditional_conversion.
3720 if (a <= CST) goto <bb 3>; else goto <bb 4>;
3724 tmp = PHI <tmp, CST>
3727 if (a <= CST) goto <bb 3>; else goto <bb 4>;
3733 Adjacent Load Hoisting
3734 ----------------------
3736 This transformation replaces
3739 if (...) goto bb2; else goto bb1;
3741 x1 = (<expr>).field1;
3744 x2 = (<expr>).field2;
3751 x1 = (<expr>).field1;
3752 x2 = (<expr>).field2;
3753 if (...) goto bb2; else goto bb1;
3760 The purpose of this transformation is to enable generation of conditional
3761 move instructions such as Intel CMOVE or PowerPC ISEL. Because one of
3762 the loads is speculative, the transformation is restricted to very
3763 specific cases to avoid introducing a page fault. We are looking for
3771 where left and right are typically adjacent pointers in a tree structure. */
3775 const pass_data pass_data_phiopt
=
3777 GIMPLE_PASS
, /* type */
3778 "phiopt", /* name */
3779 OPTGROUP_NONE
, /* optinfo_flags */
3780 TV_TREE_PHIOPT
, /* tv_id */
3781 ( PROP_cfg
| PROP_ssa
), /* properties_required */
3782 0, /* properties_provided */
3783 0, /* properties_destroyed */
3784 0, /* todo_flags_start */
3785 0, /* todo_flags_finish */
3788 class pass_phiopt
: public gimple_opt_pass
3791 pass_phiopt (gcc::context
*ctxt
)
3792 : gimple_opt_pass (pass_data_phiopt
, ctxt
), early_p (false)
3795 /* opt_pass methods: */
3796 opt_pass
* clone () { return new pass_phiopt (m_ctxt
); }
3797 void set_pass_param (unsigned n
, bool param
)
3799 gcc_assert (n
== 0);
3802 virtual bool gate (function
*) { return flag_ssa_phiopt
; }
3803 virtual unsigned int execute (function
*)
3805 return tree_ssa_phiopt_worker (false,
3806 !early_p
? gate_hoist_loads () : false,
3812 }; // class pass_phiopt
3817 make_pass_phiopt (gcc::context
*ctxt
)
3819 return new pass_phiopt (ctxt
);
3824 const pass_data pass_data_cselim
=
3826 GIMPLE_PASS
, /* type */
3827 "cselim", /* name */
3828 OPTGROUP_NONE
, /* optinfo_flags */
3829 TV_TREE_PHIOPT
, /* tv_id */
3830 ( PROP_cfg
| PROP_ssa
), /* properties_required */
3831 0, /* properties_provided */
3832 0, /* properties_destroyed */
3833 0, /* todo_flags_start */
3834 0, /* todo_flags_finish */
3837 class pass_cselim
: public gimple_opt_pass
3840 pass_cselim (gcc::context
*ctxt
)
3841 : gimple_opt_pass (pass_data_cselim
, ctxt
)
3844 /* opt_pass methods: */
3845 virtual bool gate (function
*) { return flag_tree_cselim
; }
3846 virtual unsigned int execute (function
*) { return tree_ssa_cs_elim (); }
3848 }; // class pass_cselim
3853 make_pass_cselim (gcc::context
*ctxt
)
3855 return new pass_cselim (ctxt
);