1 /* Optimization of PHI nodes by converting them into straightline code.
2 Copyright (C) 2004-2020 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"
31 #include "optabs-tree.h"
32 #include "insn-config.h"
33 #include "gimple-pretty-print.h"
34 #include "fold-const.h"
35 #include "stor-layout.h"
38 #include "gimple-iterator.h"
39 #include "gimplify-me.h"
44 #include "tree-data-ref.h"
45 #include "tree-scalar-evolution.h"
46 #include "tree-inline.h"
47 #include "case-cfn-macros.h"
49 #include "gimple-fold.h"
50 #include "internal-fn.h"
52 static unsigned int tree_ssa_phiopt_worker (bool, bool, bool);
53 static bool two_value_replacement (basic_block
, basic_block
, edge
, gphi
*,
55 static bool conditional_replacement (basic_block
, basic_block
,
56 edge
, edge
, gphi
*, tree
, tree
);
57 static gphi
*factor_out_conditional_conversion (edge
, edge
, gphi
*, tree
, tree
,
59 static int value_replacement (basic_block
, basic_block
,
60 edge
, edge
, gimple
*, tree
, tree
);
61 static bool minmax_replacement (basic_block
, basic_block
,
62 edge
, edge
, gimple
*, tree
, tree
);
63 static bool abs_replacement (basic_block
, basic_block
,
64 edge
, edge
, gimple
*, tree
, tree
);
65 static bool cond_removal_in_popcount_clz_ctz_pattern (basic_block
, basic_block
,
68 static bool cond_store_replacement (basic_block
, basic_block
, edge
, edge
,
70 static bool cond_if_else_store_replacement (basic_block
, basic_block
, basic_block
);
71 static hash_set
<tree
> * get_non_trapping ();
72 static void replace_phi_edge_with_variable (basic_block
, edge
, gimple
*, tree
);
73 static void hoist_adjacent_loads (basic_block
, basic_block
,
74 basic_block
, basic_block
);
75 static bool gate_hoist_loads (void);
77 /* This pass tries to transform conditional stores into unconditional
78 ones, enabling further simplifications with the simpler then and else
79 blocks. In particular it replaces this:
82 if (cond) goto bb2; else goto bb1;
90 if (cond) goto bb1; else goto bb2;
94 condtmp = PHI <RHS, condtmp'>
97 This transformation can only be done under several constraints,
98 documented below. It also replaces:
101 if (cond) goto bb2; else goto bb1;
112 if (cond) goto bb3; else goto bb1;
115 condtmp = PHI <RHS1, RHS2>
119 tree_ssa_cs_elim (void)
122 /* ??? We are not interested in loop related info, but the following
123 will create it, ICEing as we didn't init loops with pre-headers.
124 An interfacing issue of find_data_references_in_bb. */
125 loop_optimizer_init (LOOPS_NORMAL
);
127 todo
= tree_ssa_phiopt_worker (true, false, false);
129 loop_optimizer_finalize ();
133 /* Return the singleton PHI in the SEQ of PHIs for edges E0 and E1. */
136 single_non_singleton_phi_for_edges (gimple_seq seq
, edge e0
, edge e1
)
138 gimple_stmt_iterator i
;
140 if (gimple_seq_singleton_p (seq
))
141 return as_a
<gphi
*> (gsi_stmt (gsi_start (seq
)));
142 for (i
= gsi_start (seq
); !gsi_end_p (i
); gsi_next (&i
))
144 gphi
*p
= as_a
<gphi
*> (gsi_stmt (i
));
145 /* If the PHI arguments are equal then we can skip this PHI. */
146 if (operand_equal_for_phi_arg_p (gimple_phi_arg_def (p
, e0
->dest_idx
),
147 gimple_phi_arg_def (p
, e1
->dest_idx
)))
150 /* If we already have a PHI that has the two edge arguments are
151 different, then return it is not a singleton for these PHIs. */
160 /* The core routine of conditional store replacement and normal
161 phi optimizations. Both share much of the infrastructure in how
162 to match applicable basic block patterns. DO_STORE_ELIM is true
163 when we want to do conditional store replacement, false otherwise.
164 DO_HOIST_LOADS is true when we want to hoist adjacent loads out
165 of diamond control flow patterns, false otherwise. */
167 tree_ssa_phiopt_worker (bool do_store_elim
, bool do_hoist_loads
, bool early_p
)
170 basic_block
*bb_order
;
172 bool cfgchanged
= false;
173 hash_set
<tree
> *nontrap
= 0;
176 /* Calculate the set of non-trapping memory accesses. */
177 nontrap
= get_non_trapping ();
179 /* Search every basic block for COND_EXPR we may be able to optimize.
181 We walk the blocks in order that guarantees that a block with
182 a single predecessor is processed before the predecessor.
183 This ensures that we collapse inner ifs before visiting the
184 outer ones, and also that we do not try to visit a removed
186 bb_order
= single_pred_before_succ_order ();
187 n
= n_basic_blocks_for_fn (cfun
) - NUM_FIXED_BLOCKS
;
189 for (i
= 0; i
< n
; i
++)
193 basic_block bb1
, bb2
;
199 cond_stmt
= last_stmt (bb
);
200 /* Check to see if the last statement is a GIMPLE_COND. */
202 || gimple_code (cond_stmt
) != GIMPLE_COND
)
205 e1
= EDGE_SUCC (bb
, 0);
207 e2
= EDGE_SUCC (bb
, 1);
210 /* We cannot do the optimization on abnormal edges. */
211 if ((e1
->flags
& EDGE_ABNORMAL
) != 0
212 || (e2
->flags
& EDGE_ABNORMAL
) != 0)
215 /* If either bb1's succ or bb2 or bb2's succ is non NULL. */
216 if (EDGE_COUNT (bb1
->succs
) == 0
218 || EDGE_COUNT (bb2
->succs
) == 0)
221 /* Find the bb which is the fall through to the other. */
222 if (EDGE_SUCC (bb1
, 0)->dest
== bb2
)
224 else if (EDGE_SUCC (bb2
, 0)->dest
== bb1
)
226 std::swap (bb1
, bb2
);
229 else if (do_store_elim
230 && EDGE_SUCC (bb1
, 0)->dest
== EDGE_SUCC (bb2
, 0)->dest
)
232 basic_block bb3
= EDGE_SUCC (bb1
, 0)->dest
;
234 if (!single_succ_p (bb1
)
235 || (EDGE_SUCC (bb1
, 0)->flags
& EDGE_FALLTHRU
) == 0
236 || !single_succ_p (bb2
)
237 || (EDGE_SUCC (bb2
, 0)->flags
& EDGE_FALLTHRU
) == 0
238 || EDGE_COUNT (bb3
->preds
) != 2)
240 if (cond_if_else_store_replacement (bb1
, bb2
, bb3
))
244 else if (do_hoist_loads
245 && EDGE_SUCC (bb1
, 0)->dest
== EDGE_SUCC (bb2
, 0)->dest
)
247 basic_block bb3
= EDGE_SUCC (bb1
, 0)->dest
;
249 if (!FLOAT_TYPE_P (TREE_TYPE (gimple_cond_lhs (cond_stmt
)))
250 && single_succ_p (bb1
)
251 && single_succ_p (bb2
)
252 && single_pred_p (bb1
)
253 && single_pred_p (bb2
)
254 && EDGE_COUNT (bb
->succs
) == 2
255 && EDGE_COUNT (bb3
->preds
) == 2
256 /* If one edge or the other is dominant, a conditional move
257 is likely to perform worse than the well-predicted branch. */
258 && !predictable_edge_p (EDGE_SUCC (bb
, 0))
259 && !predictable_edge_p (EDGE_SUCC (bb
, 1)))
260 hoist_adjacent_loads (bb
, bb1
, bb2
, bb3
);
266 e1
= EDGE_SUCC (bb1
, 0);
268 /* Make sure that bb1 is just a fall through. */
269 if (!single_succ_p (bb1
)
270 || (e1
->flags
& EDGE_FALLTHRU
) == 0)
273 /* Also make sure that bb1 only have one predecessor and that it
275 if (!single_pred_p (bb1
)
276 || single_pred (bb1
) != bb
)
281 /* bb1 is the middle block, bb2 the join block, bb the split block,
282 e1 the fallthrough edge from bb1 to bb2. We can't do the
283 optimization if the join block has more than two predecessors. */
284 if (EDGE_COUNT (bb2
->preds
) > 2)
286 if (cond_store_replacement (bb1
, bb2
, e1
, e2
, nontrap
))
291 gimple_seq phis
= phi_nodes (bb2
);
292 gimple_stmt_iterator gsi
;
293 bool candorest
= true;
295 /* Value replacement can work with more than one PHI
296 so try that first. */
298 for (gsi
= gsi_start (phis
); !gsi_end_p (gsi
); gsi_next (&gsi
))
300 phi
= as_a
<gphi
*> (gsi_stmt (gsi
));
301 arg0
= gimple_phi_arg_def (phi
, e1
->dest_idx
);
302 arg1
= gimple_phi_arg_def (phi
, e2
->dest_idx
);
303 if (value_replacement (bb
, bb1
, e1
, e2
, phi
, arg0
, arg1
) == 2)
314 phi
= single_non_singleton_phi_for_edges (phis
, e1
, e2
);
318 arg0
= gimple_phi_arg_def (phi
, e1
->dest_idx
);
319 arg1
= gimple_phi_arg_def (phi
, e2
->dest_idx
);
321 /* Something is wrong if we cannot find the arguments in the PHI
323 gcc_assert (arg0
!= NULL_TREE
&& arg1
!= NULL_TREE
);
325 gphi
*newphi
= factor_out_conditional_conversion (e1
, e2
, phi
,
331 /* factor_out_conditional_conversion may create a new PHI in
332 BB2 and eliminate an existing PHI in BB2. Recompute values
333 that may be affected by that change. */
334 arg0
= gimple_phi_arg_def (phi
, e1
->dest_idx
);
335 arg1
= gimple_phi_arg_def (phi
, e2
->dest_idx
);
336 gcc_assert (arg0
!= NULL_TREE
&& arg1
!= NULL_TREE
);
339 /* Do the replacement of conditional if it can be done. */
340 if (two_value_replacement (bb
, bb1
, e2
, phi
, arg0
, arg1
))
343 && conditional_replacement (bb
, bb1
, e1
, e2
, phi
,
346 else if (abs_replacement (bb
, bb1
, e1
, e2
, phi
, arg0
, arg1
))
349 && cond_removal_in_popcount_clz_ctz_pattern (bb
, bb1
, e1
,
353 else if (minmax_replacement (bb
, bb1
, e1
, e2
, phi
, arg0
, arg1
))
362 /* If the CFG has changed, we should cleanup the CFG. */
363 if (cfgchanged
&& do_store_elim
)
365 /* In cond-store replacement we have added some loads on edges
366 and new VOPS (as we moved the store, and created a load). */
367 gsi_commit_edge_inserts ();
368 return TODO_cleanup_cfg
| TODO_update_ssa_only_virtuals
;
371 return TODO_cleanup_cfg
;
375 /* Replace PHI node element whose edge is E in block BB with variable NEW.
376 Remove the edge from COND_BLOCK which does not lead to BB (COND_BLOCK
377 is known to have two edges, one of which must reach BB). */
380 replace_phi_edge_with_variable (basic_block cond_block
,
381 edge e
, gimple
*phi
, tree new_tree
)
383 basic_block bb
= gimple_bb (phi
);
384 basic_block block_to_remove
;
385 gimple_stmt_iterator gsi
;
387 /* Change the PHI argument to new. */
388 SET_USE (PHI_ARG_DEF_PTR (phi
, e
->dest_idx
), new_tree
);
390 /* Remove the empty basic block. */
391 if (EDGE_SUCC (cond_block
, 0)->dest
== bb
)
393 EDGE_SUCC (cond_block
, 0)->flags
|= EDGE_FALLTHRU
;
394 EDGE_SUCC (cond_block
, 0)->flags
&= ~(EDGE_TRUE_VALUE
| EDGE_FALSE_VALUE
);
395 EDGE_SUCC (cond_block
, 0)->probability
= profile_probability::always ();
397 block_to_remove
= EDGE_SUCC (cond_block
, 1)->dest
;
401 EDGE_SUCC (cond_block
, 1)->flags
|= EDGE_FALLTHRU
;
402 EDGE_SUCC (cond_block
, 1)->flags
403 &= ~(EDGE_TRUE_VALUE
| EDGE_FALSE_VALUE
);
404 EDGE_SUCC (cond_block
, 1)->probability
= profile_probability::always ();
406 block_to_remove
= EDGE_SUCC (cond_block
, 0)->dest
;
408 delete_basic_block (block_to_remove
);
410 /* Eliminate the COND_EXPR at the end of COND_BLOCK. */
411 gsi
= gsi_last_bb (cond_block
);
412 gsi_remove (&gsi
, true);
414 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
416 "COND_EXPR in block %d and PHI in block %d converted to straightline code.\n",
421 /* PR66726: Factor conversion out of COND_EXPR. If the arguments of the PHI
422 stmt are CONVERT_STMT, factor out the conversion and perform the conversion
423 to the result of PHI stmt. COND_STMT is the controlling predicate.
424 Return the newly-created PHI, if any. */
427 factor_out_conditional_conversion (edge e0
, edge e1
, gphi
*phi
,
428 tree arg0
, tree arg1
, gimple
*cond_stmt
)
430 gimple
*arg0_def_stmt
= NULL
, *arg1_def_stmt
= NULL
, *new_stmt
;
431 tree new_arg0
= NULL_TREE
, new_arg1
= NULL_TREE
;
434 gimple_stmt_iterator gsi
, gsi_for_def
;
435 location_t locus
= gimple_location (phi
);
436 enum tree_code convert_code
;
438 /* Handle only PHI statements with two arguments. TODO: If all
439 other arguments to PHI are INTEGER_CST or if their defining
440 statement have the same unary operation, we can handle more
441 than two arguments too. */
442 if (gimple_phi_num_args (phi
) != 2)
445 /* First canonicalize to simplify tests. */
446 if (TREE_CODE (arg0
) != SSA_NAME
)
448 std::swap (arg0
, arg1
);
452 if (TREE_CODE (arg0
) != SSA_NAME
453 || (TREE_CODE (arg1
) != SSA_NAME
454 && TREE_CODE (arg1
) != INTEGER_CST
))
457 /* Check if arg0 is an SSA_NAME and the stmt which defines arg0 is
459 arg0_def_stmt
= SSA_NAME_DEF_STMT (arg0
);
460 if (!gimple_assign_cast_p (arg0_def_stmt
))
463 /* Use the RHS as new_arg0. */
464 convert_code
= gimple_assign_rhs_code (arg0_def_stmt
);
465 new_arg0
= gimple_assign_rhs1 (arg0_def_stmt
);
466 if (convert_code
== VIEW_CONVERT_EXPR
)
468 new_arg0
= TREE_OPERAND (new_arg0
, 0);
469 if (!is_gimple_reg_type (TREE_TYPE (new_arg0
)))
473 if (TREE_CODE (arg1
) == SSA_NAME
)
475 /* Check if arg1 is an SSA_NAME and the stmt which defines arg1
477 arg1_def_stmt
= SSA_NAME_DEF_STMT (arg1
);
478 if (!is_gimple_assign (arg1_def_stmt
)
479 || gimple_assign_rhs_code (arg1_def_stmt
) != convert_code
)
482 /* Use the RHS as new_arg1. */
483 new_arg1
= gimple_assign_rhs1 (arg1_def_stmt
);
484 if (convert_code
== VIEW_CONVERT_EXPR
)
485 new_arg1
= TREE_OPERAND (new_arg1
, 0);
489 /* If arg1 is an INTEGER_CST, fold it to new type. */
490 if (INTEGRAL_TYPE_P (TREE_TYPE (new_arg0
))
491 && int_fits_type_p (arg1
, TREE_TYPE (new_arg0
)))
493 if (gimple_assign_cast_p (arg0_def_stmt
))
495 /* For the INTEGER_CST case, we are just moving the
496 conversion from one place to another, which can often
497 hurt as the conversion moves further away from the
498 statement that computes the value. So, perform this
499 only if new_arg0 is an operand of COND_STMT, or
500 if arg0_def_stmt is the only non-debug stmt in
501 its basic block, because then it is possible this
502 could enable further optimizations (minmax replacement
503 etc.). See PR71016. */
504 if (new_arg0
!= gimple_cond_lhs (cond_stmt
)
505 && new_arg0
!= gimple_cond_rhs (cond_stmt
)
506 && gimple_bb (arg0_def_stmt
) == e0
->src
)
508 gsi
= gsi_for_stmt (arg0_def_stmt
);
509 gsi_prev_nondebug (&gsi
);
510 if (!gsi_end_p (gsi
))
513 = dyn_cast
<gassign
*> (gsi_stmt (gsi
)))
515 tree lhs
= gimple_assign_lhs (assign
);
516 enum tree_code ass_code
517 = gimple_assign_rhs_code (assign
);
518 if (ass_code
!= MAX_EXPR
&& ass_code
!= MIN_EXPR
)
520 if (lhs
!= gimple_assign_rhs1 (arg0_def_stmt
))
522 gsi_prev_nondebug (&gsi
);
523 if (!gsi_end_p (gsi
))
529 gsi
= gsi_for_stmt (arg0_def_stmt
);
530 gsi_next_nondebug (&gsi
);
531 if (!gsi_end_p (gsi
))
534 new_arg1
= fold_convert (TREE_TYPE (new_arg0
), arg1
);
543 /* If arg0/arg1 have > 1 use, then this transformation actually increases
544 the number of expressions evaluated at runtime. */
545 if (!has_single_use (arg0
)
546 || (arg1_def_stmt
&& !has_single_use (arg1
)))
549 /* If types of new_arg0 and new_arg1 are different bailout. */
550 if (!types_compatible_p (TREE_TYPE (new_arg0
), TREE_TYPE (new_arg1
)))
553 /* Create a new PHI stmt. */
554 result
= PHI_RESULT (phi
);
555 temp
= make_ssa_name (TREE_TYPE (new_arg0
), NULL
);
556 newphi
= create_phi_node (temp
, gimple_bb (phi
));
558 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
560 fprintf (dump_file
, "PHI ");
561 print_generic_expr (dump_file
, gimple_phi_result (phi
));
563 " changed to factor conversion out from COND_EXPR.\n");
564 fprintf (dump_file
, "New stmt with CAST that defines ");
565 print_generic_expr (dump_file
, result
);
566 fprintf (dump_file
, ".\n");
569 /* Remove the old cast(s) that has single use. */
570 gsi_for_def
= gsi_for_stmt (arg0_def_stmt
);
571 gsi_remove (&gsi_for_def
, true);
572 release_defs (arg0_def_stmt
);
576 gsi_for_def
= gsi_for_stmt (arg1_def_stmt
);
577 gsi_remove (&gsi_for_def
, true);
578 release_defs (arg1_def_stmt
);
581 add_phi_arg (newphi
, new_arg0
, e0
, locus
);
582 add_phi_arg (newphi
, new_arg1
, e1
, locus
);
584 /* Create the conversion stmt and insert it. */
585 if (convert_code
== VIEW_CONVERT_EXPR
)
587 temp
= fold_build1 (VIEW_CONVERT_EXPR
, TREE_TYPE (result
), temp
);
588 new_stmt
= gimple_build_assign (result
, temp
);
591 new_stmt
= gimple_build_assign (result
, convert_code
, temp
);
592 gsi
= gsi_after_labels (gimple_bb (phi
));
593 gsi_insert_before (&gsi
, new_stmt
, GSI_SAME_STMT
);
595 /* Remove the original PHI stmt. */
596 gsi
= gsi_for_stmt (phi
);
597 gsi_remove (&gsi
, true);
602 # x_5 in range [cst1, cst2] where cst2 = cst1 + 1
603 if (x_5 op cstN) # where op is == or != and N is 1 or 2
609 # r_6 = PHI<cst3(2), cst4(3)> # where cst3 == cst4 + 1 or cst4 == cst3 + 1
611 to r_6 = x_5 + (min (cst3, cst4) - cst1) or
612 r_6 = (min (cst3, cst4) + cst1) - x_5 depending on op, N and which
613 of cst3 and cst4 is smaller. */
616 two_value_replacement (basic_block cond_bb
, basic_block middle_bb
,
617 edge e1
, gphi
*phi
, tree arg0
, tree arg1
)
619 /* Only look for adjacent integer constants. */
620 if (!INTEGRAL_TYPE_P (TREE_TYPE (arg0
))
621 || !INTEGRAL_TYPE_P (TREE_TYPE (arg1
))
622 || TREE_CODE (arg0
) != INTEGER_CST
623 || TREE_CODE (arg1
) != INTEGER_CST
624 || (tree_int_cst_lt (arg0
, arg1
)
625 ? wi::to_widest (arg0
) + 1 != wi::to_widest (arg1
)
626 : wi::to_widest (arg1
) + 1 != wi::to_widest (arg0
)))
629 if (!empty_block_p (middle_bb
))
632 gimple
*stmt
= last_stmt (cond_bb
);
633 tree lhs
= gimple_cond_lhs (stmt
);
634 tree rhs
= gimple_cond_rhs (stmt
);
636 if (TREE_CODE (lhs
) != SSA_NAME
637 || !INTEGRAL_TYPE_P (TREE_TYPE (lhs
))
638 || TREE_CODE (TREE_TYPE (lhs
)) == BOOLEAN_TYPE
639 || TREE_CODE (rhs
) != INTEGER_CST
)
642 switch (gimple_cond_code (stmt
))
652 if (get_range_info (lhs
, &min
, &max
) != VR_RANGE
654 || (wi::to_wide (rhs
) != min
655 && wi::to_wide (rhs
) != max
))
658 /* We need to know which is the true edge and which is the false
659 edge so that we know when to invert the condition below. */
660 edge true_edge
, false_edge
;
661 extract_true_false_edges_from_block (cond_bb
, &true_edge
, &false_edge
);
662 if ((gimple_cond_code (stmt
) == EQ_EXPR
)
663 ^ (wi::to_wide (rhs
) == max
)
664 ^ (e1
== false_edge
))
665 std::swap (arg0
, arg1
);
668 if (TYPE_PRECISION (TREE_TYPE (lhs
)) == TYPE_PRECISION (TREE_TYPE (arg0
)))
670 /* Avoid performing the arithmetics in bool type which has different
671 semantics, otherwise prefer unsigned types from the two with
672 the same precision. */
673 if (TREE_CODE (TREE_TYPE (arg0
)) == BOOLEAN_TYPE
674 || !TYPE_UNSIGNED (TREE_TYPE (arg0
)))
675 type
= TREE_TYPE (lhs
);
677 type
= TREE_TYPE (arg0
);
679 else if (TYPE_PRECISION (TREE_TYPE (lhs
)) > TYPE_PRECISION (TREE_TYPE (arg0
)))
680 type
= TREE_TYPE (lhs
);
682 type
= TREE_TYPE (arg0
);
684 min
= wide_int::from (min
, TYPE_PRECISION (type
),
685 TYPE_SIGN (TREE_TYPE (lhs
)));
686 wide_int a
= wide_int::from (wi::to_wide (arg0
), TYPE_PRECISION (type
),
687 TYPE_SIGN (TREE_TYPE (arg0
)));
689 wi::overflow_type ovf
;
690 if (tree_int_cst_lt (arg0
, arg1
))
694 if (!TYPE_UNSIGNED (type
))
696 /* lhs is known to be in range [min, min+1] and we want to add a
697 to it. Check if that operation can overflow for those 2 values
698 and if yes, force unsigned type. */
699 wi::add (min
+ (wi::neg_p (a
) ? 0 : 1), a
, SIGNED
, &ovf
);
701 type
= unsigned_type_for (type
);
708 if (!TYPE_UNSIGNED (type
))
710 /* lhs is known to be in range [min, min+1] and we want to subtract
711 it from a. Check if that operation can overflow for those 2
712 values and if yes, force unsigned type. */
713 wi::sub (a
, min
+ (wi::neg_p (min
) ? 0 : 1), SIGNED
, &ovf
);
715 type
= unsigned_type_for (type
);
719 tree arg
= wide_int_to_tree (type
, a
);
720 gimple_stmt_iterator gsi
= gsi_for_stmt (stmt
);
721 if (!useless_type_conversion_p (type
, TREE_TYPE (lhs
)))
722 lhs
= gimplify_build1 (&gsi
, NOP_EXPR
, type
, lhs
);
724 if (code
== PLUS_EXPR
)
725 new_rhs
= gimplify_build2 (&gsi
, PLUS_EXPR
, type
, lhs
, arg
);
727 new_rhs
= gimplify_build2 (&gsi
, MINUS_EXPR
, type
, arg
, lhs
);
728 if (!useless_type_conversion_p (TREE_TYPE (arg0
), type
))
729 new_rhs
= gimplify_build1 (&gsi
, NOP_EXPR
, TREE_TYPE (arg0
), new_rhs
);
731 replace_phi_edge_with_variable (cond_bb
, e1
, phi
, new_rhs
);
733 /* Note that we optimized this PHI. */
737 /* The function conditional_replacement does the main work of doing the
738 conditional replacement. Return true if the replacement is done.
739 Otherwise return false.
740 BB is the basic block where the replacement is going to be done on. ARG0
741 is argument 0 from PHI. Likewise for ARG1. */
744 conditional_replacement (basic_block cond_bb
, basic_block middle_bb
,
745 edge e0
, edge e1
, gphi
*phi
,
746 tree arg0
, tree arg1
)
752 gimple_stmt_iterator gsi
;
753 edge true_edge
, false_edge
;
754 tree new_var
, new_var2
;
759 /* FIXME: Gimplification of complex type is too hard for now. */
760 /* We aren't prepared to handle vectors either (and it is a question
761 if it would be worthwhile anyway). */
762 if (!(INTEGRAL_TYPE_P (TREE_TYPE (arg0
))
763 || POINTER_TYPE_P (TREE_TYPE (arg0
)))
764 || !(INTEGRAL_TYPE_P (TREE_TYPE (arg1
))
765 || POINTER_TYPE_P (TREE_TYPE (arg1
))))
768 /* The PHI arguments have the constants 0 and 1, or 0 and -1 or
769 0 and (1 << cst), then convert it to the conditional. */
770 if (integer_zerop (arg0
))
772 else if (integer_zerop (arg1
))
776 if (integer_all_onesp (nonzero_arg
))
778 else if (integer_pow2p (nonzero_arg
))
780 shift
= tree_log2 (nonzero_arg
);
781 if (shift
&& POINTER_TYPE_P (TREE_TYPE (nonzero_arg
)))
787 if (!empty_block_p (middle_bb
))
790 /* At this point we know we have a GIMPLE_COND with two successors.
791 One successor is BB, the other successor is an empty block which
792 falls through into BB.
794 There is a single PHI node at the join point (BB) and its arguments
795 are constants (0, 1) or (0, -1) or (0, (1 << shift)).
797 So, given the condition COND, and the two PHI arguments, we can
798 rewrite this PHI into non-branching code:
800 dest = (COND) or dest = COND' or dest = (COND) << shift
802 We use the condition as-is if the argument associated with the
803 true edge has the value one or the argument associated with the
804 false edge as the value zero. Note that those conditions are not
805 the same since only one of the outgoing edges from the GIMPLE_COND
806 will directly reach BB and thus be associated with an argument. */
808 stmt
= last_stmt (cond_bb
);
809 result
= PHI_RESULT (phi
);
811 /* To handle special cases like floating point comparison, it is easier and
812 less error-prone to build a tree and gimplify it on the fly though it is
814 cond
= fold_build2_loc (gimple_location (stmt
),
815 gimple_cond_code (stmt
), boolean_type_node
,
816 gimple_cond_lhs (stmt
), gimple_cond_rhs (stmt
));
818 /* We need to know which is the true edge and which is the false
819 edge so that we know when to invert the condition below. */
820 extract_true_false_edges_from_block (cond_bb
, &true_edge
, &false_edge
);
821 if ((e0
== true_edge
&& integer_zerop (arg0
))
822 || (e0
== false_edge
&& !integer_zerop (arg0
))
823 || (e1
== true_edge
&& integer_zerop (arg1
))
824 || (e1
== false_edge
&& !integer_zerop (arg1
)))
825 cond
= fold_build1_loc (gimple_location (stmt
),
826 TRUTH_NOT_EXPR
, TREE_TYPE (cond
), cond
);
830 cond
= fold_convert_loc (gimple_location (stmt
),
831 TREE_TYPE (result
), cond
);
832 cond
= fold_build1_loc (gimple_location (stmt
),
833 NEGATE_EXPR
, TREE_TYPE (cond
), cond
);
837 cond
= fold_convert_loc (gimple_location (stmt
),
838 TREE_TYPE (result
), cond
);
839 cond
= fold_build2_loc (gimple_location (stmt
),
840 LSHIFT_EXPR
, TREE_TYPE (cond
), cond
,
841 build_int_cst (integer_type_node
, shift
));
844 /* Insert our new statements at the end of conditional block before the
846 gsi
= gsi_for_stmt (stmt
);
847 new_var
= force_gimple_operand_gsi (&gsi
, cond
, true, NULL
, true,
850 if (!useless_type_conversion_p (TREE_TYPE (result
), TREE_TYPE (new_var
)))
852 location_t locus_0
, locus_1
;
854 new_var2
= make_ssa_name (TREE_TYPE (result
));
855 new_stmt
= gimple_build_assign (new_var2
, CONVERT_EXPR
, new_var
);
856 gsi_insert_before (&gsi
, new_stmt
, GSI_SAME_STMT
);
859 /* Set the locus to the first argument, unless is doesn't have one. */
860 locus_0
= gimple_phi_arg_location (phi
, 0);
861 locus_1
= gimple_phi_arg_location (phi
, 1);
862 if (locus_0
== UNKNOWN_LOCATION
)
864 gimple_set_location (new_stmt
, locus_0
);
867 replace_phi_edge_with_variable (cond_bb
, e1
, phi
, new_var
);
869 /* Note that we optimized this PHI. */
873 /* Update *ARG which is defined in STMT so that it contains the
874 computed value if that seems profitable. Return true if the
875 statement is made dead by that rewriting. */
878 jump_function_from_stmt (tree
*arg
, gimple
*stmt
)
880 enum tree_code code
= gimple_assign_rhs_code (stmt
);
881 if (code
== ADDR_EXPR
)
883 /* For arg = &p->i transform it to p, if possible. */
884 tree rhs1
= gimple_assign_rhs1 (stmt
);
886 tree tem
= get_addr_base_and_unit_offset (TREE_OPERAND (rhs1
, 0),
889 && TREE_CODE (tem
) == MEM_REF
890 && known_eq (mem_ref_offset (tem
) + offset
, 0))
892 *arg
= TREE_OPERAND (tem
, 0);
896 /* TODO: Much like IPA-CP jump-functions we want to handle constant
897 additions symbolically here, and we'd need to update the comparison
898 code that compares the arg + cst tuples in our caller. For now the
899 code above exactly handles the VEC_BASE pattern from vec.h. */
903 /* RHS is a source argument in a BIT_AND_EXPR which feeds a conditional
904 of the form SSA_NAME NE 0.
906 If RHS is fed by a simple EQ_EXPR comparison of two values, see if
907 the two input values of the EQ_EXPR match arg0 and arg1.
909 If so update *code and return TRUE. Otherwise return FALSE. */
912 rhs_is_fed_for_value_replacement (const_tree arg0
, const_tree arg1
,
913 enum tree_code
*code
, const_tree rhs
)
915 /* Obviously if RHS is not an SSA_NAME, we can't look at the defining
917 if (TREE_CODE (rhs
) == SSA_NAME
)
919 gimple
*def1
= SSA_NAME_DEF_STMT (rhs
);
921 /* Verify the defining statement has an EQ_EXPR on the RHS. */
922 if (is_gimple_assign (def1
) && gimple_assign_rhs_code (def1
) == EQ_EXPR
)
924 /* Finally verify the source operands of the EQ_EXPR are equal
926 tree op0
= gimple_assign_rhs1 (def1
);
927 tree op1
= gimple_assign_rhs2 (def1
);
928 if ((operand_equal_for_phi_arg_p (arg0
, op0
)
929 && operand_equal_for_phi_arg_p (arg1
, op1
))
930 || (operand_equal_for_phi_arg_p (arg0
, op1
)
931 && operand_equal_for_phi_arg_p (arg1
, op0
)))
933 /* We will perform the optimization. */
934 *code
= gimple_assign_rhs_code (def1
);
942 /* Return TRUE if arg0/arg1 are equal to the rhs/lhs or lhs/rhs of COND.
944 Also return TRUE if arg0/arg1 are equal to the source arguments of a
945 an EQ comparison feeding a BIT_AND_EXPR which feeds COND.
947 Return FALSE otherwise. */
950 operand_equal_for_value_replacement (const_tree arg0
, const_tree arg1
,
951 enum tree_code
*code
, gimple
*cond
)
954 tree lhs
= gimple_cond_lhs (cond
);
955 tree rhs
= gimple_cond_rhs (cond
);
957 if ((operand_equal_for_phi_arg_p (arg0
, lhs
)
958 && operand_equal_for_phi_arg_p (arg1
, rhs
))
959 || (operand_equal_for_phi_arg_p (arg1
, lhs
)
960 && operand_equal_for_phi_arg_p (arg0
, rhs
)))
963 /* Now handle more complex case where we have an EQ comparison
964 which feeds a BIT_AND_EXPR which feeds COND.
966 First verify that COND is of the form SSA_NAME NE 0. */
967 if (*code
!= NE_EXPR
|| !integer_zerop (rhs
)
968 || TREE_CODE (lhs
) != SSA_NAME
)
971 /* Now ensure that SSA_NAME is set by a BIT_AND_EXPR. */
972 def
= SSA_NAME_DEF_STMT (lhs
);
973 if (!is_gimple_assign (def
) || gimple_assign_rhs_code (def
) != BIT_AND_EXPR
)
976 /* Now verify arg0/arg1 correspond to the source arguments of an
977 EQ comparison feeding the BIT_AND_EXPR. */
979 tree tmp
= gimple_assign_rhs1 (def
);
980 if (rhs_is_fed_for_value_replacement (arg0
, arg1
, code
, tmp
))
983 tmp
= gimple_assign_rhs2 (def
);
984 if (rhs_is_fed_for_value_replacement (arg0
, arg1
, code
, tmp
))
990 /* Returns true if ARG is a neutral element for operation CODE
991 on the RIGHT side. */
994 neutral_element_p (tree_code code
, tree arg
, bool right
)
1001 return integer_zerop (arg
);
1008 case POINTER_PLUS_EXPR
:
1009 return right
&& integer_zerop (arg
);
1012 return integer_onep (arg
);
1014 case TRUNC_DIV_EXPR
:
1016 case FLOOR_DIV_EXPR
:
1017 case ROUND_DIV_EXPR
:
1018 case EXACT_DIV_EXPR
:
1019 return right
&& integer_onep (arg
);
1022 return integer_all_onesp (arg
);
1029 /* Returns true if ARG is an absorbing element for operation CODE. */
1032 absorbing_element_p (tree_code code
, tree arg
, bool right
, tree rval
)
1037 return integer_all_onesp (arg
);
1041 return integer_zerop (arg
);
1047 return !right
&& integer_zerop (arg
);
1049 case TRUNC_DIV_EXPR
:
1051 case FLOOR_DIV_EXPR
:
1052 case ROUND_DIV_EXPR
:
1053 case EXACT_DIV_EXPR
:
1054 case TRUNC_MOD_EXPR
:
1056 case FLOOR_MOD_EXPR
:
1057 case ROUND_MOD_EXPR
:
1059 && integer_zerop (arg
)
1060 && tree_single_nonzero_warnv_p (rval
, NULL
));
1067 /* The function value_replacement does the main work of doing the value
1068 replacement. Return non-zero if the replacement is done. Otherwise return
1069 0. If we remove the middle basic block, return 2.
1070 BB is the basic block where the replacement is going to be done on. ARG0
1071 is argument 0 from the PHI. Likewise for ARG1. */
1074 value_replacement (basic_block cond_bb
, basic_block middle_bb
,
1075 edge e0
, edge e1
, gimple
*phi
,
1076 tree arg0
, tree arg1
)
1078 gimple_stmt_iterator gsi
;
1080 edge true_edge
, false_edge
;
1081 enum tree_code code
;
1082 bool empty_or_with_defined_p
= true;
1084 /* If the type says honor signed zeros we cannot do this
1086 if (HONOR_SIGNED_ZEROS (arg1
))
1089 /* If there is a statement in MIDDLE_BB that defines one of the PHI
1090 arguments, then adjust arg0 or arg1. */
1091 gsi
= gsi_start_nondebug_after_labels_bb (middle_bb
);
1092 while (!gsi_end_p (gsi
))
1094 gimple
*stmt
= gsi_stmt (gsi
);
1096 gsi_next_nondebug (&gsi
);
1097 if (!is_gimple_assign (stmt
))
1099 if (gimple_code (stmt
) != GIMPLE_PREDICT
1100 && gimple_code (stmt
) != GIMPLE_NOP
)
1101 empty_or_with_defined_p
= false;
1104 /* Now try to adjust arg0 or arg1 according to the computation
1105 in the statement. */
1106 lhs
= gimple_assign_lhs (stmt
);
1108 && jump_function_from_stmt (&arg0
, stmt
))
1110 && jump_function_from_stmt (&arg1
, stmt
)))
1111 empty_or_with_defined_p
= false;
1114 cond
= last_stmt (cond_bb
);
1115 code
= gimple_cond_code (cond
);
1117 /* This transformation is only valid for equality comparisons. */
1118 if (code
!= NE_EXPR
&& code
!= EQ_EXPR
)
1121 /* We need to know which is the true edge and which is the false
1122 edge so that we know if have abs or negative abs. */
1123 extract_true_false_edges_from_block (cond_bb
, &true_edge
, &false_edge
);
1125 /* At this point we know we have a COND_EXPR with two successors.
1126 One successor is BB, the other successor is an empty block which
1127 falls through into BB.
1129 The condition for the COND_EXPR is known to be NE_EXPR or EQ_EXPR.
1131 There is a single PHI node at the join point (BB) with two arguments.
1133 We now need to verify that the two arguments in the PHI node match
1134 the two arguments to the equality comparison. */
1136 if (operand_equal_for_value_replacement (arg0
, arg1
, &code
, cond
))
1141 /* For NE_EXPR, we want to build an assignment result = arg where
1142 arg is the PHI argument associated with the true edge. For
1143 EQ_EXPR we want the PHI argument associated with the false edge. */
1144 e
= (code
== NE_EXPR
? true_edge
: false_edge
);
1146 /* Unfortunately, E may not reach BB (it may instead have gone to
1147 OTHER_BLOCK). If that is the case, then we want the single outgoing
1148 edge from OTHER_BLOCK which reaches BB and represents the desired
1149 path from COND_BLOCK. */
1150 if (e
->dest
== middle_bb
)
1151 e
= single_succ_edge (e
->dest
);
1153 /* Now we know the incoming edge to BB that has the argument for the
1154 RHS of our new assignment statement. */
1160 /* If the middle basic block was empty or is defining the
1161 PHI arguments and this is a single phi where the args are different
1162 for the edges e0 and e1 then we can remove the middle basic block. */
1163 if (empty_or_with_defined_p
1164 && single_non_singleton_phi_for_edges (phi_nodes (gimple_bb (phi
)),
1167 replace_phi_edge_with_variable (cond_bb
, e1
, phi
, arg
);
1168 /* Note that we optimized this PHI. */
1173 /* Replace the PHI arguments with arg. */
1174 SET_PHI_ARG_DEF (phi
, e0
->dest_idx
, arg
);
1175 SET_PHI_ARG_DEF (phi
, e1
->dest_idx
, arg
);
1176 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
1178 fprintf (dump_file
, "PHI ");
1179 print_generic_expr (dump_file
, gimple_phi_result (phi
));
1180 fprintf (dump_file
, " reduced for COND_EXPR in block %d to ",
1182 print_generic_expr (dump_file
, arg
);
1183 fprintf (dump_file
, ".\n");
1190 /* Now optimize (x != 0) ? x + y : y to just x + y. */
1191 gsi
= gsi_last_nondebug_bb (middle_bb
);
1192 if (gsi_end_p (gsi
))
1195 gimple
*assign
= gsi_stmt (gsi
);
1196 if (!is_gimple_assign (assign
)
1197 || gimple_assign_rhs_class (assign
) != GIMPLE_BINARY_RHS
1198 || (!INTEGRAL_TYPE_P (TREE_TYPE (arg0
))
1199 && !POINTER_TYPE_P (TREE_TYPE (arg0
))))
1202 /* Punt if there are (degenerate) PHIs in middle_bb, there should not be. */
1203 if (!gimple_seq_empty_p (phi_nodes (middle_bb
)))
1206 /* Allow up to 2 cheap preparation statements that prepare argument
1214 iftmp.0_6 = x_5(D) r<< _1;
1216 # iftmp.0_2 = PHI <iftmp.0_6(3), x_5(D)(2)>
1227 # _2 = PHI <x_5(D)(2), _6(3)> */
1228 gimple
*prep_stmt
[2] = { NULL
, NULL
};
1230 for (prep_cnt
= 0; ; prep_cnt
++)
1232 gsi_prev_nondebug (&gsi
);
1233 if (gsi_end_p (gsi
))
1236 gimple
*g
= gsi_stmt (gsi
);
1237 if (gimple_code (g
) == GIMPLE_LABEL
)
1240 if (prep_cnt
== 2 || !is_gimple_assign (g
))
1243 tree lhs
= gimple_assign_lhs (g
);
1244 tree rhs1
= gimple_assign_rhs1 (g
);
1245 use_operand_p use_p
;
1247 if (TREE_CODE (lhs
) != SSA_NAME
1248 || TREE_CODE (rhs1
) != SSA_NAME
1249 || !INTEGRAL_TYPE_P (TREE_TYPE (lhs
))
1250 || !INTEGRAL_TYPE_P (TREE_TYPE (rhs1
))
1251 || !single_imm_use (lhs
, &use_p
, &use_stmt
)
1252 || use_stmt
!= (prep_cnt
? prep_stmt
[prep_cnt
- 1] : assign
))
1254 switch (gimple_assign_rhs_code (g
))
1262 if (TREE_CODE (gimple_assign_rhs2 (g
)) != INTEGER_CST
)
1268 prep_stmt
[prep_cnt
] = g
;
1271 /* Only transform if it removes the condition. */
1272 if (!single_non_singleton_phi_for_edges (phi_nodes (gimple_bb (phi
)), e0
, e1
))
1275 /* Size-wise, this is always profitable. */
1276 if (optimize_bb_for_speed_p (cond_bb
)
1277 /* The special case is useless if it has a low probability. */
1278 && profile_status_for_fn (cfun
) != PROFILE_ABSENT
1279 && EDGE_PRED (middle_bb
, 0)->probability
< profile_probability::even ()
1280 /* If assign is cheap, there is no point avoiding it. */
1281 && estimate_num_insns_seq (bb_seq (middle_bb
), &eni_time_weights
)
1282 >= 3 * estimate_num_insns (cond
, &eni_time_weights
))
1285 tree lhs
= gimple_assign_lhs (assign
);
1286 tree rhs1
= gimple_assign_rhs1 (assign
);
1287 tree rhs2
= gimple_assign_rhs2 (assign
);
1288 enum tree_code code_def
= gimple_assign_rhs_code (assign
);
1289 tree cond_lhs
= gimple_cond_lhs (cond
);
1290 tree cond_rhs
= gimple_cond_rhs (cond
);
1292 /* Propagate the cond_rhs constant through preparation stmts,
1293 make sure UB isn't invoked while doing that. */
1294 for (int i
= prep_cnt
- 1; i
>= 0; --i
)
1296 gimple
*g
= prep_stmt
[i
];
1297 tree grhs1
= gimple_assign_rhs1 (g
);
1298 if (!operand_equal_for_phi_arg_p (cond_lhs
, grhs1
))
1300 cond_lhs
= gimple_assign_lhs (g
);
1301 cond_rhs
= fold_convert (TREE_TYPE (grhs1
), cond_rhs
);
1302 if (TREE_CODE (cond_rhs
) != INTEGER_CST
1303 || TREE_OVERFLOW (cond_rhs
))
1305 if (gimple_assign_rhs_class (g
) == GIMPLE_BINARY_RHS
)
1307 cond_rhs
= int_const_binop (gimple_assign_rhs_code (g
), cond_rhs
,
1308 gimple_assign_rhs2 (g
));
1309 if (TREE_OVERFLOW (cond_rhs
))
1312 cond_rhs
= fold_convert (TREE_TYPE (cond_lhs
), cond_rhs
);
1313 if (TREE_CODE (cond_rhs
) != INTEGER_CST
1314 || TREE_OVERFLOW (cond_rhs
))
1318 if (((code
== NE_EXPR
&& e1
== false_edge
)
1319 || (code
== EQ_EXPR
&& e1
== true_edge
))
1322 && operand_equal_for_phi_arg_p (rhs2
, cond_lhs
)
1323 && neutral_element_p (code_def
, cond_rhs
, true))
1325 && operand_equal_for_phi_arg_p (rhs1
, cond_lhs
)
1326 && neutral_element_p (code_def
, cond_rhs
, false))
1327 || (operand_equal_for_phi_arg_p (arg1
, cond_rhs
)
1328 && ((operand_equal_for_phi_arg_p (rhs2
, cond_lhs
)
1329 && absorbing_element_p (code_def
, cond_rhs
, true, rhs2
))
1330 || (operand_equal_for_phi_arg_p (rhs1
, cond_lhs
)
1331 && absorbing_element_p (code_def
,
1332 cond_rhs
, false, rhs2
))))))
1334 gsi
= gsi_for_stmt (cond
);
1335 /* Moving ASSIGN might change VR of lhs, e.g. when moving u_6
1343 # RANGE [0, 4294967294]
1344 u_6 = n_5 + 4294967295;
1347 # u_3 = PHI <u_6(3), 4294967295(2)> */
1348 reset_flow_sensitive_info (lhs
);
1349 if (INTEGRAL_TYPE_P (TREE_TYPE (lhs
)))
1351 /* If available, we can use VR of phi result at least. */
1352 tree phires
= gimple_phi_result (phi
);
1353 struct range_info_def
*phires_range_info
1354 = SSA_NAME_RANGE_INFO (phires
);
1355 if (phires_range_info
)
1356 duplicate_ssa_name_range_info (lhs
, SSA_NAME_RANGE_TYPE (phires
),
1359 gimple_stmt_iterator gsi_from
;
1360 for (int i
= prep_cnt
- 1; i
>= 0; --i
)
1362 tree plhs
= gimple_assign_lhs (prep_stmt
[i
]);
1363 reset_flow_sensitive_info (plhs
);
1364 gsi_from
= gsi_for_stmt (prep_stmt
[i
]);
1365 gsi_move_before (&gsi_from
, &gsi
);
1367 gsi_from
= gsi_for_stmt (assign
);
1368 gsi_move_before (&gsi_from
, &gsi
);
1369 replace_phi_edge_with_variable (cond_bb
, e1
, phi
, lhs
);
1376 /* The function minmax_replacement does the main work of doing the minmax
1377 replacement. Return true if the replacement is done. Otherwise return
1379 BB is the basic block where the replacement is going to be done on. ARG0
1380 is argument 0 from the PHI. Likewise for ARG1. */
1383 minmax_replacement (basic_block cond_bb
, basic_block middle_bb
,
1384 edge e0
, edge e1
, gimple
*phi
,
1385 tree arg0
, tree arg1
)
1388 edge true_edge
, false_edge
;
1389 enum tree_code minmax
, ass_code
;
1390 tree smaller
, larger
, arg_true
, arg_false
;
1391 gimple_stmt_iterator gsi
, gsi_from
;
1393 tree type
= TREE_TYPE (PHI_RESULT (phi
));
1395 /* The optimization may be unsafe due to NaNs. */
1396 if (HONOR_NANS (type
) || HONOR_SIGNED_ZEROS (type
))
1399 gcond
*cond
= as_a
<gcond
*> (last_stmt (cond_bb
));
1400 enum tree_code cmp
= gimple_cond_code (cond
);
1401 tree rhs
= gimple_cond_rhs (cond
);
1403 /* Turn EQ/NE of extreme values to order comparisons. */
1404 if ((cmp
== NE_EXPR
|| cmp
== EQ_EXPR
)
1405 && TREE_CODE (rhs
) == INTEGER_CST
1406 && INTEGRAL_TYPE_P (TREE_TYPE (rhs
)))
1408 if (wi::eq_p (wi::to_wide (rhs
), wi::min_value (TREE_TYPE (rhs
))))
1410 cmp
= (cmp
== EQ_EXPR
) ? LT_EXPR
: GE_EXPR
;
1411 rhs
= wide_int_to_tree (TREE_TYPE (rhs
),
1412 wi::min_value (TREE_TYPE (rhs
)) + 1);
1414 else if (wi::eq_p (wi::to_wide (rhs
), wi::max_value (TREE_TYPE (rhs
))))
1416 cmp
= (cmp
== EQ_EXPR
) ? GT_EXPR
: LE_EXPR
;
1417 rhs
= wide_int_to_tree (TREE_TYPE (rhs
),
1418 wi::max_value (TREE_TYPE (rhs
)) - 1);
1422 /* This transformation is only valid for order comparisons. Record which
1423 operand is smaller/larger if the result of the comparison is true. */
1424 tree alt_smaller
= NULL_TREE
;
1425 tree alt_larger
= NULL_TREE
;
1426 if (cmp
== LT_EXPR
|| cmp
== LE_EXPR
)
1428 smaller
= gimple_cond_lhs (cond
);
1430 /* If we have smaller < CST it is equivalent to smaller <= CST-1.
1431 Likewise smaller <= CST is equivalent to smaller < CST+1. */
1432 if (TREE_CODE (larger
) == INTEGER_CST
1433 && INTEGRAL_TYPE_P (TREE_TYPE (larger
)))
1437 wi::overflow_type overflow
;
1438 wide_int alt
= wi::sub (wi::to_wide (larger
), 1,
1439 TYPE_SIGN (TREE_TYPE (larger
)),
1442 alt_larger
= wide_int_to_tree (TREE_TYPE (larger
), alt
);
1446 wi::overflow_type overflow
;
1447 wide_int alt
= wi::add (wi::to_wide (larger
), 1,
1448 TYPE_SIGN (TREE_TYPE (larger
)),
1451 alt_larger
= wide_int_to_tree (TREE_TYPE (larger
), alt
);
1455 else if (cmp
== GT_EXPR
|| cmp
== GE_EXPR
)
1458 larger
= gimple_cond_lhs (cond
);
1459 /* If we have larger > CST it is equivalent to larger >= CST+1.
1460 Likewise larger >= CST is equivalent to larger > CST-1. */
1461 if (TREE_CODE (smaller
) == INTEGER_CST
1462 && INTEGRAL_TYPE_P (TREE_TYPE (smaller
)))
1464 wi::overflow_type overflow
;
1467 wide_int alt
= wi::add (wi::to_wide (smaller
), 1,
1468 TYPE_SIGN (TREE_TYPE (smaller
)),
1471 alt_smaller
= wide_int_to_tree (TREE_TYPE (smaller
), alt
);
1475 wide_int alt
= wi::sub (wi::to_wide (smaller
), 1,
1476 TYPE_SIGN (TREE_TYPE (smaller
)),
1479 alt_smaller
= wide_int_to_tree (TREE_TYPE (smaller
), alt
);
1486 /* Handle the special case of (signed_type)x < 0 being equivalent
1487 to x > MAX_VAL(signed_type) and (signed_type)x >= 0 equivalent
1488 to x <= MAX_VAL(signed_type). */
1489 if ((cmp
== GE_EXPR
|| cmp
== LT_EXPR
)
1490 && INTEGRAL_TYPE_P (type
)
1491 && TYPE_UNSIGNED (type
)
1492 && integer_zerop (rhs
))
1494 tree op
= gimple_cond_lhs (cond
);
1495 if (TREE_CODE (op
) == SSA_NAME
1496 && INTEGRAL_TYPE_P (TREE_TYPE (op
))
1497 && !TYPE_UNSIGNED (TREE_TYPE (op
)))
1499 gimple
*def_stmt
= SSA_NAME_DEF_STMT (op
);
1500 if (gimple_assign_cast_p (def_stmt
))
1502 tree op1
= gimple_assign_rhs1 (def_stmt
);
1503 if (INTEGRAL_TYPE_P (TREE_TYPE (op1
))
1504 && TYPE_UNSIGNED (TREE_TYPE (op1
))
1505 && (TYPE_PRECISION (TREE_TYPE (op
))
1506 == TYPE_PRECISION (TREE_TYPE (op1
)))
1507 && useless_type_conversion_p (type
, TREE_TYPE (op1
)))
1509 wide_int w1
= wi::max_value (TREE_TYPE (op
));
1510 wide_int w2
= wi::add (w1
, 1);
1514 smaller
= wide_int_to_tree (TREE_TYPE (op1
), w1
);
1515 alt_smaller
= wide_int_to_tree (TREE_TYPE (op1
), w2
);
1516 alt_larger
= NULL_TREE
;
1521 larger
= wide_int_to_tree (TREE_TYPE (op1
), w1
);
1522 alt_larger
= wide_int_to_tree (TREE_TYPE (op1
), w2
);
1523 alt_smaller
= NULL_TREE
;
1530 /* We need to know which is the true edge and which is the false
1531 edge so that we know if have abs or negative abs. */
1532 extract_true_false_edges_from_block (cond_bb
, &true_edge
, &false_edge
);
1534 /* Forward the edges over the middle basic block. */
1535 if (true_edge
->dest
== middle_bb
)
1536 true_edge
= EDGE_SUCC (true_edge
->dest
, 0);
1537 if (false_edge
->dest
== middle_bb
)
1538 false_edge
= EDGE_SUCC (false_edge
->dest
, 0);
1540 if (true_edge
== e0
)
1542 gcc_assert (false_edge
== e1
);
1548 gcc_assert (false_edge
== e0
);
1549 gcc_assert (true_edge
== e1
);
1554 if (empty_block_p (middle_bb
))
1556 if ((operand_equal_for_phi_arg_p (arg_true
, smaller
)
1558 && operand_equal_for_phi_arg_p (arg_true
, alt_smaller
)))
1559 && (operand_equal_for_phi_arg_p (arg_false
, larger
)
1561 && operand_equal_for_phi_arg_p (arg_true
, alt_larger
))))
1565 if (smaller < larger)
1571 else if ((operand_equal_for_phi_arg_p (arg_false
, smaller
)
1573 && operand_equal_for_phi_arg_p (arg_false
, alt_smaller
)))
1574 && (operand_equal_for_phi_arg_p (arg_true
, larger
)
1576 && operand_equal_for_phi_arg_p (arg_true
, alt_larger
))))
1583 /* Recognize the following case, assuming d <= u:
1589 This is equivalent to
1594 gimple
*assign
= last_and_only_stmt (middle_bb
);
1595 tree lhs
, op0
, op1
, bound
;
1598 || gimple_code (assign
) != GIMPLE_ASSIGN
)
1601 lhs
= gimple_assign_lhs (assign
);
1602 ass_code
= gimple_assign_rhs_code (assign
);
1603 if (ass_code
!= MAX_EXPR
&& ass_code
!= MIN_EXPR
)
1605 op0
= gimple_assign_rhs1 (assign
);
1606 op1
= gimple_assign_rhs2 (assign
);
1608 if (true_edge
->src
== middle_bb
)
1610 /* We got here if the condition is true, i.e., SMALLER < LARGER. */
1611 if (!operand_equal_for_phi_arg_p (lhs
, arg_true
))
1614 if (operand_equal_for_phi_arg_p (arg_false
, larger
)
1616 && operand_equal_for_phi_arg_p (arg_false
, alt_larger
)))
1620 if (smaller < larger)
1622 r' = MAX_EXPR (smaller, bound)
1624 r = PHI <r', larger> --> to be turned to MIN_EXPR. */
1625 if (ass_code
!= MAX_EXPR
)
1629 if (operand_equal_for_phi_arg_p (op0
, smaller
)
1631 && operand_equal_for_phi_arg_p (op0
, alt_smaller
)))
1633 else if (operand_equal_for_phi_arg_p (op1
, smaller
)
1635 && operand_equal_for_phi_arg_p (op1
, alt_smaller
)))
1640 /* We need BOUND <= LARGER. */
1641 if (!integer_nonzerop (fold_build2 (LE_EXPR
, boolean_type_node
,
1645 else if (operand_equal_for_phi_arg_p (arg_false
, smaller
)
1647 && operand_equal_for_phi_arg_p (arg_false
, alt_smaller
)))
1651 if (smaller < larger)
1653 r' = MIN_EXPR (larger, bound)
1655 r = PHI <r', smaller> --> to be turned to MAX_EXPR. */
1656 if (ass_code
!= MIN_EXPR
)
1660 if (operand_equal_for_phi_arg_p (op0
, larger
)
1662 && operand_equal_for_phi_arg_p (op0
, alt_larger
)))
1664 else if (operand_equal_for_phi_arg_p (op1
, larger
)
1666 && operand_equal_for_phi_arg_p (op1
, alt_larger
)))
1671 /* We need BOUND >= SMALLER. */
1672 if (!integer_nonzerop (fold_build2 (GE_EXPR
, boolean_type_node
,
1681 /* We got here if the condition is false, i.e., SMALLER > LARGER. */
1682 if (!operand_equal_for_phi_arg_p (lhs
, arg_false
))
1685 if (operand_equal_for_phi_arg_p (arg_true
, larger
)
1687 && operand_equal_for_phi_arg_p (arg_true
, alt_larger
)))
1691 if (smaller > larger)
1693 r' = MIN_EXPR (smaller, bound)
1695 r = PHI <r', larger> --> to be turned to MAX_EXPR. */
1696 if (ass_code
!= MIN_EXPR
)
1700 if (operand_equal_for_phi_arg_p (op0
, smaller
)
1702 && operand_equal_for_phi_arg_p (op0
, alt_smaller
)))
1704 else if (operand_equal_for_phi_arg_p (op1
, smaller
)
1706 && operand_equal_for_phi_arg_p (op1
, alt_smaller
)))
1711 /* We need BOUND >= LARGER. */
1712 if (!integer_nonzerop (fold_build2 (GE_EXPR
, boolean_type_node
,
1716 else if (operand_equal_for_phi_arg_p (arg_true
, smaller
)
1718 && operand_equal_for_phi_arg_p (arg_true
, alt_smaller
)))
1722 if (smaller > larger)
1724 r' = MAX_EXPR (larger, bound)
1726 r = PHI <r', smaller> --> to be turned to MIN_EXPR. */
1727 if (ass_code
!= MAX_EXPR
)
1731 if (operand_equal_for_phi_arg_p (op0
, larger
))
1733 else if (operand_equal_for_phi_arg_p (op1
, larger
))
1738 /* We need BOUND <= SMALLER. */
1739 if (!integer_nonzerop (fold_build2 (LE_EXPR
, boolean_type_node
,
1747 /* Move the statement from the middle block. */
1748 gsi
= gsi_last_bb (cond_bb
);
1749 gsi_from
= gsi_last_nondebug_bb (middle_bb
);
1750 reset_flow_sensitive_info (SINGLE_SSA_TREE_OPERAND (gsi_stmt (gsi_from
),
1752 gsi_move_before (&gsi_from
, &gsi
);
1755 /* Emit the statement to compute min/max. */
1756 gimple_seq stmts
= NULL
;
1757 tree phi_result
= PHI_RESULT (phi
);
1758 result
= gimple_build (&stmts
, minmax
, TREE_TYPE (phi_result
), arg0
, arg1
);
1759 /* Duplicate range info if we're the only things setting the target PHI. */
1760 if (!gimple_seq_empty_p (stmts
)
1761 && EDGE_COUNT (gimple_bb (phi
)->preds
) == 2
1762 && !POINTER_TYPE_P (TREE_TYPE (phi_result
))
1763 && SSA_NAME_RANGE_INFO (phi_result
))
1764 duplicate_ssa_name_range_info (result
, SSA_NAME_RANGE_TYPE (phi_result
),
1765 SSA_NAME_RANGE_INFO (phi_result
));
1767 gsi
= gsi_last_bb (cond_bb
);
1768 gsi_insert_seq_before (&gsi
, stmts
, GSI_NEW_STMT
);
1770 replace_phi_edge_with_variable (cond_bb
, e1
, phi
, result
);
1784 _2 = (unsigned long) b_4(D);
1785 _9 = __builtin_popcountl (_2);
1787 _9 = __builtin_popcountl (b_4(D));
1790 c_12 = PHI <0(2), _9(3)>
1794 _2 = (unsigned long) b_4(D);
1795 _9 = __builtin_popcountl (_2);
1797 _9 = __builtin_popcountl (b_4(D));
1802 Similarly for __builtin_clz or __builtin_ctz if
1803 C?Z_DEFINED_VALUE_AT_ZERO is 2, optab is present and
1804 instead of 0 above it uses the value from that macro. */
1807 cond_removal_in_popcount_clz_ctz_pattern (basic_block cond_bb
,
1808 basic_block middle_bb
,
1809 edge e1
, edge e2
, gimple
*phi
,
1810 tree arg0
, tree arg1
)
1813 gimple_stmt_iterator gsi
, gsi_from
;
1815 gimple
*cast
= NULL
;
1819 _2 = (unsigned long) b_4(D);
1820 _9 = __builtin_popcountl (_2);
1822 _9 = __builtin_popcountl (b_4(D));
1823 are the only stmts in the middle_bb. */
1825 gsi
= gsi_start_nondebug_after_labels_bb (middle_bb
);
1826 if (gsi_end_p (gsi
))
1828 cast
= gsi_stmt (gsi
);
1829 gsi_next_nondebug (&gsi
);
1830 if (!gsi_end_p (gsi
))
1832 call
= gsi_stmt (gsi
);
1833 gsi_next_nondebug (&gsi
);
1834 if (!gsi_end_p (gsi
))
1843 /* Check that we have a popcount/clz/ctz builtin. */
1844 if (!is_gimple_call (call
) || gimple_call_num_args (call
) != 1)
1847 arg
= gimple_call_arg (call
, 0);
1848 lhs
= gimple_get_lhs (call
);
1850 if (lhs
== NULL_TREE
)
1853 combined_fn cfn
= gimple_call_combined_fn (call
);
1854 internal_fn ifn
= IFN_LAST
;
1861 if (INTEGRAL_TYPE_P (TREE_TYPE (arg
)))
1863 tree type
= TREE_TYPE (arg
);
1864 if (direct_internal_fn_supported_p (IFN_CLZ
, type
, OPTIMIZE_FOR_BOTH
)
1865 && CLZ_DEFINED_VALUE_AT_ZERO (SCALAR_INT_TYPE_MODE (type
),
1874 if (INTEGRAL_TYPE_P (TREE_TYPE (arg
)))
1876 tree type
= TREE_TYPE (arg
);
1877 if (direct_internal_fn_supported_p (IFN_CTZ
, type
, OPTIMIZE_FOR_BOTH
)
1878 && CTZ_DEFINED_VALUE_AT_ZERO (SCALAR_INT_TYPE_MODE (type
),
1892 /* We have a cast stmt feeding popcount/clz/ctz builtin. */
1893 /* Check that we have a cast prior to that. */
1894 if (gimple_code (cast
) != GIMPLE_ASSIGN
1895 || !CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (cast
)))
1897 /* Result of the cast stmt is the argument to the builtin. */
1898 if (arg
!= gimple_assign_lhs (cast
))
1900 arg
= gimple_assign_rhs1 (cast
);
1903 cond
= last_stmt (cond_bb
);
1905 /* Cond_bb has a check for b_4 [!=|==] 0 before calling the popcount/clz/ctz
1907 if (gimple_code (cond
) != GIMPLE_COND
1908 || (gimple_cond_code (cond
) != NE_EXPR
1909 && gimple_cond_code (cond
) != EQ_EXPR
)
1910 || !integer_zerop (gimple_cond_rhs (cond
))
1911 || arg
!= gimple_cond_lhs (cond
))
1915 if ((e2
->flags
& EDGE_TRUE_VALUE
1916 && gimple_cond_code (cond
) == NE_EXPR
)
1917 || (e1
->flags
& EDGE_TRUE_VALUE
1918 && gimple_cond_code (cond
) == EQ_EXPR
))
1920 std::swap (arg0
, arg1
);
1924 /* Check PHI arguments. */
1926 || TREE_CODE (arg1
) != INTEGER_CST
1927 || wi::to_wide (arg1
) != val
)
1930 /* And insert the popcount/clz/ctz builtin and cast stmt before the
1932 gsi
= gsi_last_bb (cond_bb
);
1935 gsi_from
= gsi_for_stmt (cast
);
1936 gsi_move_before (&gsi_from
, &gsi
);
1937 reset_flow_sensitive_info (gimple_get_lhs (cast
));
1939 gsi_from
= gsi_for_stmt (call
);
1940 if (ifn
== IFN_LAST
|| gimple_call_internal_p (call
))
1941 gsi_move_before (&gsi_from
, &gsi
);
1944 /* For __builtin_c[lt]z* force .C[LT]Z ifn, because only
1945 the latter is well defined at zero. */
1946 call
= gimple_build_call_internal (ifn
, 1, gimple_call_arg (call
, 0));
1947 gimple_call_set_lhs (call
, lhs
);
1948 gsi_insert_before (&gsi
, call
, GSI_SAME_STMT
);
1949 gsi_remove (&gsi_from
, true);
1951 reset_flow_sensitive_info (lhs
);
1953 /* Now update the PHI and remove unneeded bbs. */
1954 replace_phi_edge_with_variable (cond_bb
, e2
, phi
, lhs
);
1958 /* The function absolute_replacement does the main work of doing the absolute
1959 replacement. Return true if the replacement is done. Otherwise return
1961 bb is the basic block where the replacement is going to be done on. arg0
1962 is argument 0 from the phi. Likewise for arg1. */
1965 abs_replacement (basic_block cond_bb
, basic_block middle_bb
,
1966 edge e0 ATTRIBUTE_UNUSED
, edge e1
,
1967 gimple
*phi
, tree arg0
, tree arg1
)
1972 gimple_stmt_iterator gsi
;
1973 edge true_edge
, false_edge
;
1978 enum tree_code cond_code
;
1980 /* If the type says honor signed zeros we cannot do this
1982 if (HONOR_SIGNED_ZEROS (arg1
))
1985 /* OTHER_BLOCK must have only one executable statement which must have the
1986 form arg0 = -arg1 or arg1 = -arg0. */
1988 assign
= last_and_only_stmt (middle_bb
);
1989 /* If we did not find the proper negation assignment, then we cannot
1994 /* If we got here, then we have found the only executable statement
1995 in OTHER_BLOCK. If it is anything other than arg = -arg1 or
1996 arg1 = -arg0, then we cannot optimize. */
1997 if (gimple_code (assign
) != GIMPLE_ASSIGN
)
2000 lhs
= gimple_assign_lhs (assign
);
2002 if (gimple_assign_rhs_code (assign
) != NEGATE_EXPR
)
2005 rhs
= gimple_assign_rhs1 (assign
);
2007 /* The assignment has to be arg0 = -arg1 or arg1 = -arg0. */
2008 if (!(lhs
== arg0
&& rhs
== arg1
)
2009 && !(lhs
== arg1
&& rhs
== arg0
))
2012 cond
= last_stmt (cond_bb
);
2013 result
= PHI_RESULT (phi
);
2015 /* Only relationals comparing arg[01] against zero are interesting. */
2016 cond_code
= gimple_cond_code (cond
);
2017 if (cond_code
!= GT_EXPR
&& cond_code
!= GE_EXPR
2018 && cond_code
!= LT_EXPR
&& cond_code
!= LE_EXPR
)
2021 /* Make sure the conditional is arg[01] OP y. */
2022 if (gimple_cond_lhs (cond
) != rhs
)
2025 if (FLOAT_TYPE_P (TREE_TYPE (gimple_cond_rhs (cond
)))
2026 ? real_zerop (gimple_cond_rhs (cond
))
2027 : integer_zerop (gimple_cond_rhs (cond
)))
2032 /* We need to know which is the true edge and which is the false
2033 edge so that we know if have abs or negative abs. */
2034 extract_true_false_edges_from_block (cond_bb
, &true_edge
, &false_edge
);
2036 /* For GT_EXPR/GE_EXPR, if the true edge goes to OTHER_BLOCK, then we
2037 will need to negate the result. Similarly for LT_EXPR/LE_EXPR if
2038 the false edge goes to OTHER_BLOCK. */
2039 if (cond_code
== GT_EXPR
|| cond_code
== GE_EXPR
)
2044 if (e
->dest
== middle_bb
)
2049 /* If the code negates only iff positive then make sure to not
2050 introduce undefined behavior when negating or computing the absolute.
2051 ??? We could use range info if present to check for arg1 == INT_MIN. */
2053 && (ANY_INTEGRAL_TYPE_P (TREE_TYPE (arg1
))
2054 && ! TYPE_OVERFLOW_WRAPS (TREE_TYPE (arg1
))))
2057 result
= duplicate_ssa_name (result
, NULL
);
2060 lhs
= make_ssa_name (TREE_TYPE (result
));
2064 /* Build the modify expression with abs expression. */
2065 new_stmt
= gimple_build_assign (lhs
, ABS_EXPR
, rhs
);
2067 gsi
= gsi_last_bb (cond_bb
);
2068 gsi_insert_before (&gsi
, new_stmt
, GSI_NEW_STMT
);
2072 /* Get the right GSI. We want to insert after the recently
2073 added ABS_EXPR statement (which we know is the first statement
2075 new_stmt
= gimple_build_assign (result
, NEGATE_EXPR
, lhs
);
2077 gsi_insert_after (&gsi
, new_stmt
, GSI_NEW_STMT
);
2080 replace_phi_edge_with_variable (cond_bb
, e1
, phi
, result
);
2082 /* Note that we optimized this PHI. */
2086 /* Auxiliary functions to determine the set of memory accesses which
2087 can't trap because they are preceded by accesses to the same memory
2088 portion. We do that for MEM_REFs, so we only need to track
2089 the SSA_NAME of the pointer indirectly referenced. The algorithm
2090 simply is a walk over all instructions in dominator order. When
2091 we see an MEM_REF we determine if we've already seen a same
2092 ref anywhere up to the root of the dominator tree. If we do the
2093 current access can't trap. If we don't see any dominating access
2094 the current access might trap, but might also make later accesses
2095 non-trapping, so we remember it. We need to be careful with loads
2096 or stores, for instance a load might not trap, while a store would,
2097 so if we see a dominating read access this doesn't mean that a later
2098 write access would not trap. Hence we also need to differentiate the
2099 type of access(es) seen.
2101 ??? We currently are very conservative and assume that a load might
2102 trap even if a store doesn't (write-only memory). This probably is
2103 overly conservative.
2105 We currently support a special case that for !TREE_ADDRESSABLE automatic
2106 variables, it could ignore whether something is a load or store because the
2107 local stack should be always writable. */
2109 /* A hash-table of references (MEM_REF/ARRAY_REF/COMPONENT_REF), and in which
2110 basic block an *_REF through it was seen, which would constitute a
2111 no-trap region for same accesses.
2113 Size is needed to support 2 MEM_REFs of different types, like
2114 MEM<double>(s_1) and MEM<long>(s_1), which would compare equal with
2124 /* Hashtable helpers. */
2126 struct refs_hasher
: free_ptr_hash
<ref_to_bb
>
2128 static inline hashval_t
hash (const ref_to_bb
*);
2129 static inline bool equal (const ref_to_bb
*, const ref_to_bb
*);
2132 /* Used for quick clearing of the hash-table when we see calls.
2133 Hash entries with phase < nt_call_phase are invalid. */
2134 static unsigned int nt_call_phase
;
2136 /* The hash function. */
2139 refs_hasher::hash (const ref_to_bb
*n
)
2141 inchash::hash hstate
;
2142 inchash::add_expr (n
->exp
, hstate
, OEP_ADDRESS_OF
);
2143 hstate
.add_hwi (n
->size
);
2144 return hstate
.end ();
2147 /* The equality function of *P1 and *P2. */
2150 refs_hasher::equal (const ref_to_bb
*n1
, const ref_to_bb
*n2
)
2152 return operand_equal_p (n1
->exp
, n2
->exp
, OEP_ADDRESS_OF
)
2153 && n1
->size
== n2
->size
;
2156 class nontrapping_dom_walker
: public dom_walker
2159 nontrapping_dom_walker (cdi_direction direction
, hash_set
<tree
> *ps
)
2160 : dom_walker (direction
), m_nontrapping (ps
), m_seen_refs (128)
2163 virtual edge
before_dom_children (basic_block
);
2164 virtual void after_dom_children (basic_block
);
2168 /* We see the expression EXP in basic block BB. If it's an interesting
2169 expression (an MEM_REF through an SSA_NAME) possibly insert the
2170 expression into the set NONTRAP or the hash table of seen expressions.
2171 STORE is true if this expression is on the LHS, otherwise it's on
2173 void add_or_mark_expr (basic_block
, tree
, bool);
2175 hash_set
<tree
> *m_nontrapping
;
2177 /* The hash table for remembering what we've seen. */
2178 hash_table
<refs_hasher
> m_seen_refs
;
2181 /* Called by walk_dominator_tree, when entering the block BB. */
2183 nontrapping_dom_walker::before_dom_children (basic_block bb
)
2187 gimple_stmt_iterator gsi
;
2189 /* If we haven't seen all our predecessors, clear the hash-table. */
2190 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
2191 if ((((size_t)e
->src
->aux
) & 2) == 0)
2197 /* Mark this BB as being on the path to dominator root and as visited. */
2198 bb
->aux
= (void*)(1 | 2);
2200 /* And walk the statements in order. */
2201 for (gsi
= gsi_start_bb (bb
); !gsi_end_p (gsi
); gsi_next (&gsi
))
2203 gimple
*stmt
= gsi_stmt (gsi
);
2205 if ((gimple_code (stmt
) == GIMPLE_ASM
&& gimple_vdef (stmt
))
2206 || (is_gimple_call (stmt
)
2207 && (!nonfreeing_call_p (stmt
) || !nonbarrier_call_p (stmt
))))
2209 else if (gimple_assign_single_p (stmt
) && !gimple_has_volatile_ops (stmt
))
2211 add_or_mark_expr (bb
, gimple_assign_lhs (stmt
), true);
2212 add_or_mark_expr (bb
, gimple_assign_rhs1 (stmt
), false);
2218 /* Called by walk_dominator_tree, when basic block BB is exited. */
2220 nontrapping_dom_walker::after_dom_children (basic_block bb
)
2222 /* This BB isn't on the path to dominator root anymore. */
2226 /* We see the expression EXP in basic block BB. If it's an interesting
2231 possibly insert the expression into the set NONTRAP or the hash table
2232 of seen expressions. STORE is true if this expression is on the LHS,
2233 otherwise it's on the RHS. */
2235 nontrapping_dom_walker::add_or_mark_expr (basic_block bb
, tree exp
, bool store
)
2239 if ((TREE_CODE (exp
) == MEM_REF
|| TREE_CODE (exp
) == ARRAY_REF
2240 || TREE_CODE (exp
) == COMPONENT_REF
)
2241 && (size
= int_size_in_bytes (TREE_TYPE (exp
))) > 0)
2243 struct ref_to_bb map
;
2245 struct ref_to_bb
*r2bb
;
2246 basic_block found_bb
= 0;
2250 tree base
= get_base_address (exp
);
2251 /* Only record a LOAD of a local variable without address-taken, as
2252 the local stack is always writable. This allows cselim on a STORE
2253 with a dominating LOAD. */
2254 if (!auto_var_p (base
) || TREE_ADDRESSABLE (base
))
2258 /* Try to find the last seen *_REF, which can trap. */
2261 slot
= m_seen_refs
.find_slot (&map
, INSERT
);
2263 if (r2bb
&& r2bb
->phase
>= nt_call_phase
)
2264 found_bb
= r2bb
->bb
;
2266 /* If we've found a trapping *_REF, _and_ it dominates EXP
2267 (it's in a basic block on the path from us to the dominator root)
2268 then we can't trap. */
2269 if (found_bb
&& (((size_t)found_bb
->aux
) & 1) == 1)
2271 m_nontrapping
->add (exp
);
2275 /* EXP might trap, so insert it into the hash table. */
2278 r2bb
->phase
= nt_call_phase
;
2283 r2bb
= XNEW (struct ref_to_bb
);
2284 r2bb
->phase
= nt_call_phase
;
2294 /* This is the entry point of gathering non trapping memory accesses.
2295 It will do a dominator walk over the whole function, and it will
2296 make use of the bb->aux pointers. It returns a set of trees
2297 (the MEM_REFs itself) which can't trap. */
2298 static hash_set
<tree
> *
2299 get_non_trapping (void)
2302 hash_set
<tree
> *nontrap
= new hash_set
<tree
>;
2303 /* We're going to do a dominator walk, so ensure that we have
2304 dominance information. */
2305 calculate_dominance_info (CDI_DOMINATORS
);
2307 nontrapping_dom_walker (CDI_DOMINATORS
, nontrap
)
2308 .walk (cfun
->cfg
->x_entry_block_ptr
);
2310 clear_aux_for_blocks ();
2314 /* Do the main work of conditional store replacement. We already know
2315 that the recognized pattern looks like so:
2318 if (cond) goto MIDDLE_BB; else goto JOIN_BB (edge E1)
2321 fallthrough (edge E0)
2325 We check that MIDDLE_BB contains only one store, that that store
2326 doesn't trap (not via NOTRAP, but via checking if an access to the same
2327 memory location dominates us, or the store is to a local addressable
2328 object) and that the store has a "simple" RHS. */
2331 cond_store_replacement (basic_block middle_bb
, basic_block join_bb
,
2332 edge e0
, edge e1
, hash_set
<tree
> *nontrap
)
2334 gimple
*assign
= last_and_only_stmt (middle_bb
);
2335 tree lhs
, rhs
, name
, name2
;
2338 gimple_stmt_iterator gsi
;
2341 /* Check if middle_bb contains of only one store. */
2343 || !gimple_assign_single_p (assign
)
2344 || gimple_has_volatile_ops (assign
))
2347 /* And no PHI nodes so all uses in the single stmt are also
2348 available where we insert to. */
2349 if (!gimple_seq_empty_p (phi_nodes (middle_bb
)))
2352 locus
= gimple_location (assign
);
2353 lhs
= gimple_assign_lhs (assign
);
2354 rhs
= gimple_assign_rhs1 (assign
);
2355 if ((TREE_CODE (lhs
) != MEM_REF
2356 && TREE_CODE (lhs
) != ARRAY_REF
2357 && TREE_CODE (lhs
) != COMPONENT_REF
)
2358 || !is_gimple_reg_type (TREE_TYPE (lhs
)))
2361 /* Prove that we can move the store down. We could also check
2362 TREE_THIS_NOTRAP here, but in that case we also could move stores,
2363 whose value is not available readily, which we want to avoid. */
2364 if (!nontrap
->contains (lhs
))
2366 /* If LHS is an access to a local variable without address-taken
2367 (or when we allow data races) and known not to trap, we could
2368 always safely move down the store. */
2369 tree base
= get_base_address (lhs
);
2370 if (!auto_var_p (base
)
2371 || (TREE_ADDRESSABLE (base
) && !flag_store_data_races
)
2372 || tree_could_trap_p (lhs
))
2376 /* Now we've checked the constraints, so do the transformation:
2377 1) Remove the single store. */
2378 gsi
= gsi_for_stmt (assign
);
2379 unlink_stmt_vdef (assign
);
2380 gsi_remove (&gsi
, true);
2381 release_defs (assign
);
2383 /* Make both store and load use alias-set zero as we have to
2384 deal with the case of the store being a conditional change
2385 of the dynamic type. */
2386 lhs
= unshare_expr (lhs
);
2388 while (handled_component_p (*basep
))
2389 basep
= &TREE_OPERAND (*basep
, 0);
2390 if (TREE_CODE (*basep
) == MEM_REF
2391 || TREE_CODE (*basep
) == TARGET_MEM_REF
)
2392 TREE_OPERAND (*basep
, 1)
2393 = fold_convert (ptr_type_node
, TREE_OPERAND (*basep
, 1));
2395 *basep
= build2 (MEM_REF
, TREE_TYPE (*basep
),
2396 build_fold_addr_expr (*basep
),
2397 build_zero_cst (ptr_type_node
));
2399 /* 2) Insert a load from the memory of the store to the temporary
2400 on the edge which did not contain the store. */
2401 name
= make_temp_ssa_name (TREE_TYPE (lhs
), NULL
, "cstore");
2402 new_stmt
= gimple_build_assign (name
, lhs
);
2403 gimple_set_location (new_stmt
, locus
);
2404 lhs
= unshare_expr (lhs
);
2405 /* Set TREE_NO_WARNING on the rhs of the load to avoid uninit
2407 TREE_NO_WARNING (gimple_assign_rhs1 (new_stmt
)) = 1;
2408 gsi_insert_on_edge (e1
, new_stmt
);
2410 /* 3) Create a PHI node at the join block, with one argument
2411 holding the old RHS, and the other holding the temporary
2412 where we stored the old memory contents. */
2413 name2
= make_temp_ssa_name (TREE_TYPE (lhs
), NULL
, "cstore");
2414 newphi
= create_phi_node (name2
, join_bb
);
2415 add_phi_arg (newphi
, rhs
, e0
, locus
);
2416 add_phi_arg (newphi
, name
, e1
, locus
);
2418 new_stmt
= gimple_build_assign (lhs
, PHI_RESULT (newphi
));
2420 /* 4) Insert that PHI node. */
2421 gsi
= gsi_after_labels (join_bb
);
2422 if (gsi_end_p (gsi
))
2424 gsi
= gsi_last_bb (join_bb
);
2425 gsi_insert_after (&gsi
, new_stmt
, GSI_NEW_STMT
);
2428 gsi_insert_before (&gsi
, new_stmt
, GSI_NEW_STMT
);
2430 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2432 fprintf (dump_file
, "\nConditional store replacement happened!");
2433 fprintf (dump_file
, "\nReplaced the store with a load.");
2434 fprintf (dump_file
, "\nInserted a new PHI statement in joint block:\n");
2435 print_gimple_stmt (dump_file
, new_stmt
, 0, TDF_VOPS
|TDF_MEMSYMS
);
2441 /* Do the main work of conditional store replacement. */
2444 cond_if_else_store_replacement_1 (basic_block then_bb
, basic_block else_bb
,
2445 basic_block join_bb
, gimple
*then_assign
,
2446 gimple
*else_assign
)
2448 tree lhs_base
, lhs
, then_rhs
, else_rhs
, name
;
2449 location_t then_locus
, else_locus
;
2450 gimple_stmt_iterator gsi
;
2454 if (then_assign
== NULL
2455 || !gimple_assign_single_p (then_assign
)
2456 || gimple_clobber_p (then_assign
)
2457 || gimple_has_volatile_ops (then_assign
)
2458 || else_assign
== NULL
2459 || !gimple_assign_single_p (else_assign
)
2460 || gimple_clobber_p (else_assign
)
2461 || gimple_has_volatile_ops (else_assign
))
2464 lhs
= gimple_assign_lhs (then_assign
);
2465 if (!is_gimple_reg_type (TREE_TYPE (lhs
))
2466 || !operand_equal_p (lhs
, gimple_assign_lhs (else_assign
), 0))
2469 lhs_base
= get_base_address (lhs
);
2470 if (lhs_base
== NULL_TREE
2471 || (!DECL_P (lhs_base
) && TREE_CODE (lhs_base
) != MEM_REF
))
2474 then_rhs
= gimple_assign_rhs1 (then_assign
);
2475 else_rhs
= gimple_assign_rhs1 (else_assign
);
2476 then_locus
= gimple_location (then_assign
);
2477 else_locus
= gimple_location (else_assign
);
2479 /* Now we've checked the constraints, so do the transformation:
2480 1) Remove the stores. */
2481 gsi
= gsi_for_stmt (then_assign
);
2482 unlink_stmt_vdef (then_assign
);
2483 gsi_remove (&gsi
, true);
2484 release_defs (then_assign
);
2486 gsi
= gsi_for_stmt (else_assign
);
2487 unlink_stmt_vdef (else_assign
);
2488 gsi_remove (&gsi
, true);
2489 release_defs (else_assign
);
2491 /* 2) Create a PHI node at the join block, with one argument
2492 holding the old RHS, and the other holding the temporary
2493 where we stored the old memory contents. */
2494 name
= make_temp_ssa_name (TREE_TYPE (lhs
), NULL
, "cstore");
2495 newphi
= create_phi_node (name
, join_bb
);
2496 add_phi_arg (newphi
, then_rhs
, EDGE_SUCC (then_bb
, 0), then_locus
);
2497 add_phi_arg (newphi
, else_rhs
, EDGE_SUCC (else_bb
, 0), else_locus
);
2499 new_stmt
= gimple_build_assign (lhs
, PHI_RESULT (newphi
));
2501 /* 3) Insert that PHI node. */
2502 gsi
= gsi_after_labels (join_bb
);
2503 if (gsi_end_p (gsi
))
2505 gsi
= gsi_last_bb (join_bb
);
2506 gsi_insert_after (&gsi
, new_stmt
, GSI_NEW_STMT
);
2509 gsi_insert_before (&gsi
, new_stmt
, GSI_NEW_STMT
);
2514 /* Return the single store in BB with VDEF or NULL if there are
2515 other stores in the BB or loads following the store. */
2518 single_trailing_store_in_bb (basic_block bb
, tree vdef
)
2520 if (SSA_NAME_IS_DEFAULT_DEF (vdef
))
2522 gimple
*store
= SSA_NAME_DEF_STMT (vdef
);
2523 if (gimple_bb (store
) != bb
2524 || gimple_code (store
) == GIMPLE_PHI
)
2527 /* Verify there is no other store in this BB. */
2528 if (!SSA_NAME_IS_DEFAULT_DEF (gimple_vuse (store
))
2529 && gimple_bb (SSA_NAME_DEF_STMT (gimple_vuse (store
))) == bb
2530 && gimple_code (SSA_NAME_DEF_STMT (gimple_vuse (store
))) != GIMPLE_PHI
)
2533 /* Verify there is no load or store after the store. */
2534 use_operand_p use_p
;
2535 imm_use_iterator imm_iter
;
2536 FOR_EACH_IMM_USE_FAST (use_p
, imm_iter
, gimple_vdef (store
))
2537 if (USE_STMT (use_p
) != store
2538 && gimple_bb (USE_STMT (use_p
)) == bb
)
2544 /* Conditional store replacement. We already know
2545 that the recognized pattern looks like so:
2548 if (cond) goto THEN_BB; else goto ELSE_BB (edge E1)
2558 fallthrough (edge E0)
2562 We check that it is safe to sink the store to JOIN_BB by verifying that
2563 there are no read-after-write or write-after-write dependencies in
2564 THEN_BB and ELSE_BB. */
2567 cond_if_else_store_replacement (basic_block then_bb
, basic_block else_bb
,
2568 basic_block join_bb
)
2570 vec
<data_reference_p
> then_datarefs
, else_datarefs
;
2571 vec
<ddr_p
> then_ddrs
, else_ddrs
;
2572 gimple
*then_store
, *else_store
;
2573 bool found
, ok
= false, res
;
2574 struct data_dependence_relation
*ddr
;
2575 data_reference_p then_dr
, else_dr
;
2577 tree then_lhs
, else_lhs
;
2578 basic_block blocks
[3];
2580 /* Handle the case with single store in THEN_BB and ELSE_BB. That is
2581 cheap enough to always handle as it allows us to elide dependence
2584 for (gphi_iterator si
= gsi_start_phis (join_bb
); !gsi_end_p (si
);
2586 if (virtual_operand_p (gimple_phi_result (si
.phi ())))
2593 tree then_vdef
= PHI_ARG_DEF_FROM_EDGE (vphi
, single_succ_edge (then_bb
));
2594 tree else_vdef
= PHI_ARG_DEF_FROM_EDGE (vphi
, single_succ_edge (else_bb
));
2595 gimple
*then_assign
= single_trailing_store_in_bb (then_bb
, then_vdef
);
2598 gimple
*else_assign
= single_trailing_store_in_bb (else_bb
, else_vdef
);
2600 return cond_if_else_store_replacement_1 (then_bb
, else_bb
, join_bb
,
2601 then_assign
, else_assign
);
2604 /* If either vectorization or if-conversion is disabled then do
2605 not sink any stores. */
2606 if (param_max_stores_to_sink
== 0
2607 || (!flag_tree_loop_vectorize
&& !flag_tree_slp_vectorize
)
2608 || !flag_tree_loop_if_convert
)
2611 /* Find data references. */
2612 then_datarefs
.create (1);
2613 else_datarefs
.create (1);
2614 if ((find_data_references_in_bb (NULL
, then_bb
, &then_datarefs
)
2616 || !then_datarefs
.length ()
2617 || (find_data_references_in_bb (NULL
, else_bb
, &else_datarefs
)
2619 || !else_datarefs
.length ())
2621 free_data_refs (then_datarefs
);
2622 free_data_refs (else_datarefs
);
2626 /* Find pairs of stores with equal LHS. */
2627 auto_vec
<gimple
*, 1> then_stores
, else_stores
;
2628 FOR_EACH_VEC_ELT (then_datarefs
, i
, then_dr
)
2630 if (DR_IS_READ (then_dr
))
2633 then_store
= DR_STMT (then_dr
);
2634 then_lhs
= gimple_get_lhs (then_store
);
2635 if (then_lhs
== NULL_TREE
)
2639 FOR_EACH_VEC_ELT (else_datarefs
, j
, else_dr
)
2641 if (DR_IS_READ (else_dr
))
2644 else_store
= DR_STMT (else_dr
);
2645 else_lhs
= gimple_get_lhs (else_store
);
2646 if (else_lhs
== NULL_TREE
)
2649 if (operand_equal_p (then_lhs
, else_lhs
, 0))
2659 then_stores
.safe_push (then_store
);
2660 else_stores
.safe_push (else_store
);
2663 /* No pairs of stores found. */
2664 if (!then_stores
.length ()
2665 || then_stores
.length () > (unsigned) param_max_stores_to_sink
)
2667 free_data_refs (then_datarefs
);
2668 free_data_refs (else_datarefs
);
2672 /* Compute and check data dependencies in both basic blocks. */
2673 then_ddrs
.create (1);
2674 else_ddrs
.create (1);
2675 if (!compute_all_dependences (then_datarefs
, &then_ddrs
,
2677 || !compute_all_dependences (else_datarefs
, &else_ddrs
,
2680 free_dependence_relations (then_ddrs
);
2681 free_dependence_relations (else_ddrs
);
2682 free_data_refs (then_datarefs
);
2683 free_data_refs (else_datarefs
);
2686 blocks
[0] = then_bb
;
2687 blocks
[1] = else_bb
;
2688 blocks
[2] = join_bb
;
2689 renumber_gimple_stmt_uids_in_blocks (blocks
, 3);
2691 /* Check that there are no read-after-write or write-after-write dependencies
2693 FOR_EACH_VEC_ELT (then_ddrs
, i
, ddr
)
2695 struct data_reference
*dra
= DDR_A (ddr
);
2696 struct data_reference
*drb
= DDR_B (ddr
);
2698 if (DDR_ARE_DEPENDENT (ddr
) != chrec_known
2699 && ((DR_IS_READ (dra
) && DR_IS_WRITE (drb
)
2700 && gimple_uid (DR_STMT (dra
)) > gimple_uid (DR_STMT (drb
)))
2701 || (DR_IS_READ (drb
) && DR_IS_WRITE (dra
)
2702 && gimple_uid (DR_STMT (drb
)) > gimple_uid (DR_STMT (dra
)))
2703 || (DR_IS_WRITE (dra
) && DR_IS_WRITE (drb
))))
2705 free_dependence_relations (then_ddrs
);
2706 free_dependence_relations (else_ddrs
);
2707 free_data_refs (then_datarefs
);
2708 free_data_refs (else_datarefs
);
2713 /* Check that there are no read-after-write or write-after-write dependencies
2715 FOR_EACH_VEC_ELT (else_ddrs
, i
, ddr
)
2717 struct data_reference
*dra
= DDR_A (ddr
);
2718 struct data_reference
*drb
= DDR_B (ddr
);
2720 if (DDR_ARE_DEPENDENT (ddr
) != chrec_known
2721 && ((DR_IS_READ (dra
) && DR_IS_WRITE (drb
)
2722 && gimple_uid (DR_STMT (dra
)) > gimple_uid (DR_STMT (drb
)))
2723 || (DR_IS_READ (drb
) && DR_IS_WRITE (dra
)
2724 && gimple_uid (DR_STMT (drb
)) > gimple_uid (DR_STMT (dra
)))
2725 || (DR_IS_WRITE (dra
) && DR_IS_WRITE (drb
))))
2727 free_dependence_relations (then_ddrs
);
2728 free_dependence_relations (else_ddrs
);
2729 free_data_refs (then_datarefs
);
2730 free_data_refs (else_datarefs
);
2735 /* Sink stores with same LHS. */
2736 FOR_EACH_VEC_ELT (then_stores
, i
, then_store
)
2738 else_store
= else_stores
[i
];
2739 res
= cond_if_else_store_replacement_1 (then_bb
, else_bb
, join_bb
,
2740 then_store
, else_store
);
2744 free_dependence_relations (then_ddrs
);
2745 free_dependence_relations (else_ddrs
);
2746 free_data_refs (then_datarefs
);
2747 free_data_refs (else_datarefs
);
2752 /* Return TRUE if STMT has a VUSE whose corresponding VDEF is in BB. */
2755 local_mem_dependence (gimple
*stmt
, basic_block bb
)
2757 tree vuse
= gimple_vuse (stmt
);
2763 def
= SSA_NAME_DEF_STMT (vuse
);
2764 return (def
&& gimple_bb (def
) == bb
);
2767 /* Given a "diamond" control-flow pattern where BB0 tests a condition,
2768 BB1 and BB2 are "then" and "else" blocks dependent on this test,
2769 and BB3 rejoins control flow following BB1 and BB2, look for
2770 opportunities to hoist loads as follows. If BB3 contains a PHI of
2771 two loads, one each occurring in BB1 and BB2, and the loads are
2772 provably of adjacent fields in the same structure, then move both
2773 loads into BB0. Of course this can only be done if there are no
2774 dependencies preventing such motion.
2776 One of the hoisted loads will always be speculative, so the
2777 transformation is currently conservative:
2779 - The fields must be strictly adjacent.
2780 - The two fields must occupy a single memory block that is
2781 guaranteed to not cross a page boundary.
2783 The last is difficult to prove, as such memory blocks should be
2784 aligned on the minimum of the stack alignment boundary and the
2785 alignment guaranteed by heap allocation interfaces. Thus we rely
2786 on a parameter for the alignment value.
2788 Provided a good value is used for the last case, the first
2789 restriction could possibly be relaxed. */
2792 hoist_adjacent_loads (basic_block bb0
, basic_block bb1
,
2793 basic_block bb2
, basic_block bb3
)
2795 int param_align
= param_l1_cache_line_size
;
2796 unsigned param_align_bits
= (unsigned) (param_align
* BITS_PER_UNIT
);
2799 /* Walk the phis in bb3 looking for an opportunity. We are looking
2800 for phis of two SSA names, one each of which is defined in bb1 and
2802 for (gsi
= gsi_start_phis (bb3
); !gsi_end_p (gsi
); gsi_next (&gsi
))
2804 gphi
*phi_stmt
= gsi
.phi ();
2805 gimple
*def1
, *def2
;
2806 tree arg1
, arg2
, ref1
, ref2
, field1
, field2
;
2807 tree tree_offset1
, tree_offset2
, tree_size2
, next
;
2808 int offset1
, offset2
, size2
;
2810 gimple_stmt_iterator gsi2
;
2811 basic_block bb_for_def1
, bb_for_def2
;
2813 if (gimple_phi_num_args (phi_stmt
) != 2
2814 || virtual_operand_p (gimple_phi_result (phi_stmt
)))
2817 arg1
= gimple_phi_arg_def (phi_stmt
, 0);
2818 arg2
= gimple_phi_arg_def (phi_stmt
, 1);
2820 if (TREE_CODE (arg1
) != SSA_NAME
2821 || TREE_CODE (arg2
) != SSA_NAME
2822 || SSA_NAME_IS_DEFAULT_DEF (arg1
)
2823 || SSA_NAME_IS_DEFAULT_DEF (arg2
))
2826 def1
= SSA_NAME_DEF_STMT (arg1
);
2827 def2
= SSA_NAME_DEF_STMT (arg2
);
2829 if ((gimple_bb (def1
) != bb1
|| gimple_bb (def2
) != bb2
)
2830 && (gimple_bb (def2
) != bb1
|| gimple_bb (def1
) != bb2
))
2833 /* Check the mode of the arguments to be sure a conditional move
2834 can be generated for it. */
2835 if (optab_handler (movcc_optab
, TYPE_MODE (TREE_TYPE (arg1
)))
2836 == CODE_FOR_nothing
)
2839 /* Both statements must be assignments whose RHS is a COMPONENT_REF. */
2840 if (!gimple_assign_single_p (def1
)
2841 || !gimple_assign_single_p (def2
)
2842 || gimple_has_volatile_ops (def1
)
2843 || gimple_has_volatile_ops (def2
))
2846 ref1
= gimple_assign_rhs1 (def1
);
2847 ref2
= gimple_assign_rhs1 (def2
);
2849 if (TREE_CODE (ref1
) != COMPONENT_REF
2850 || TREE_CODE (ref2
) != COMPONENT_REF
)
2853 /* The zeroth operand of the two component references must be
2854 identical. It is not sufficient to compare get_base_address of
2855 the two references, because this could allow for different
2856 elements of the same array in the two trees. It is not safe to
2857 assume that the existence of one array element implies the
2858 existence of a different one. */
2859 if (!operand_equal_p (TREE_OPERAND (ref1
, 0), TREE_OPERAND (ref2
, 0), 0))
2862 field1
= TREE_OPERAND (ref1
, 1);
2863 field2
= TREE_OPERAND (ref2
, 1);
2865 /* Check for field adjacency, and ensure field1 comes first. */
2866 for (next
= DECL_CHAIN (field1
);
2867 next
&& TREE_CODE (next
) != FIELD_DECL
;
2868 next
= DECL_CHAIN (next
))
2873 for (next
= DECL_CHAIN (field2
);
2874 next
&& TREE_CODE (next
) != FIELD_DECL
;
2875 next
= DECL_CHAIN (next
))
2881 std::swap (field1
, field2
);
2882 std::swap (def1
, def2
);
2885 bb_for_def1
= gimple_bb (def1
);
2886 bb_for_def2
= gimple_bb (def2
);
2888 /* Check for proper alignment of the first field. */
2889 tree_offset1
= bit_position (field1
);
2890 tree_offset2
= bit_position (field2
);
2891 tree_size2
= DECL_SIZE (field2
);
2893 if (!tree_fits_uhwi_p (tree_offset1
)
2894 || !tree_fits_uhwi_p (tree_offset2
)
2895 || !tree_fits_uhwi_p (tree_size2
))
2898 offset1
= tree_to_uhwi (tree_offset1
);
2899 offset2
= tree_to_uhwi (tree_offset2
);
2900 size2
= tree_to_uhwi (tree_size2
);
2901 align1
= DECL_ALIGN (field1
) % param_align_bits
;
2903 if (offset1
% BITS_PER_UNIT
!= 0)
2906 /* For profitability, the two field references should fit within
2907 a single cache line. */
2908 if (align1
+ offset2
- offset1
+ size2
> param_align_bits
)
2911 /* The two expressions cannot be dependent upon vdefs defined
2913 if (local_mem_dependence (def1
, bb_for_def1
)
2914 || local_mem_dependence (def2
, bb_for_def2
))
2917 /* The conditions are satisfied; hoist the loads from bb1 and bb2 into
2918 bb0. We hoist the first one first so that a cache miss is handled
2919 efficiently regardless of hardware cache-fill policy. */
2920 gsi2
= gsi_for_stmt (def1
);
2921 gsi_move_to_bb_end (&gsi2
, bb0
);
2922 gsi2
= gsi_for_stmt (def2
);
2923 gsi_move_to_bb_end (&gsi2
, bb0
);
2925 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2928 "\nHoisting adjacent loads from %d and %d into %d: \n",
2929 bb_for_def1
->index
, bb_for_def2
->index
, bb0
->index
);
2930 print_gimple_stmt (dump_file
, def1
, 0, TDF_VOPS
|TDF_MEMSYMS
);
2931 print_gimple_stmt (dump_file
, def2
, 0, TDF_VOPS
|TDF_MEMSYMS
);
2936 /* Determine whether we should attempt to hoist adjacent loads out of
2937 diamond patterns in pass_phiopt. Always hoist loads if
2938 -fhoist-adjacent-loads is specified and the target machine has
2939 both a conditional move instruction and a defined cache line size. */
2942 gate_hoist_loads (void)
2944 return (flag_hoist_adjacent_loads
== 1
2945 && param_l1_cache_line_size
2946 && HAVE_conditional_move
);
2949 /* This pass tries to replaces an if-then-else block with an
2950 assignment. We have four kinds of transformations. Some of these
2951 transformations are also performed by the ifcvt RTL optimizer.
2953 Conditional Replacement
2954 -----------------------
2956 This transformation, implemented in conditional_replacement,
2960 if (cond) goto bb2; else goto bb1;
2963 x = PHI <0 (bb1), 1 (bb0), ...>;
2971 x = PHI <x' (bb0), ...>;
2973 We remove bb1 as it becomes unreachable. This occurs often due to
2974 gimplification of conditionals.
2979 This transformation, implemented in value_replacement, replaces
2982 if (a != b) goto bb2; else goto bb1;
2985 x = PHI <a (bb1), b (bb0), ...>;
2991 x = PHI <b (bb0), ...>;
2993 This opportunity can sometimes occur as a result of other
2997 Another case caught by value replacement looks like this:
3003 if (t3 != 0) goto bb1; else goto bb2;
3019 This transformation, implemented in abs_replacement, replaces
3022 if (a >= 0) goto bb2; else goto bb1;
3026 x = PHI <x (bb1), a (bb0), ...>;
3033 x = PHI <x' (bb0), ...>;
3038 This transformation, minmax_replacement replaces
3041 if (a <= b) goto bb2; else goto bb1;
3044 x = PHI <b (bb1), a (bb0), ...>;
3049 x' = MIN_EXPR (a, b)
3051 x = PHI <x' (bb0), ...>;
3053 A similar transformation is done for MAX_EXPR.
3056 This pass also performs a fifth transformation of a slightly different
3059 Factor conversion in COND_EXPR
3060 ------------------------------
3062 This transformation factors the conversion out of COND_EXPR with
3063 factor_out_conditional_conversion.
3066 if (a <= CST) goto <bb 3>; else goto <bb 4>;
3070 tmp = PHI <tmp, CST>
3073 if (a <= CST) goto <bb 3>; else goto <bb 4>;
3079 Adjacent Load Hoisting
3080 ----------------------
3082 This transformation replaces
3085 if (...) goto bb2; else goto bb1;
3087 x1 = (<expr>).field1;
3090 x2 = (<expr>).field2;
3097 x1 = (<expr>).field1;
3098 x2 = (<expr>).field2;
3099 if (...) goto bb2; else goto bb1;
3106 The purpose of this transformation is to enable generation of conditional
3107 move instructions such as Intel CMOVE or PowerPC ISEL. Because one of
3108 the loads is speculative, the transformation is restricted to very
3109 specific cases to avoid introducing a page fault. We are looking for
3117 where left and right are typically adjacent pointers in a tree structure. */
3121 const pass_data pass_data_phiopt
=
3123 GIMPLE_PASS
, /* type */
3124 "phiopt", /* name */
3125 OPTGROUP_NONE
, /* optinfo_flags */
3126 TV_TREE_PHIOPT
, /* tv_id */
3127 ( PROP_cfg
| PROP_ssa
), /* properties_required */
3128 0, /* properties_provided */
3129 0, /* properties_destroyed */
3130 0, /* todo_flags_start */
3131 0, /* todo_flags_finish */
3134 class pass_phiopt
: public gimple_opt_pass
3137 pass_phiopt (gcc::context
*ctxt
)
3138 : gimple_opt_pass (pass_data_phiopt
, ctxt
), early_p (false)
3141 /* opt_pass methods: */
3142 opt_pass
* clone () { return new pass_phiopt (m_ctxt
); }
3143 void set_pass_param (unsigned n
, bool param
)
3145 gcc_assert (n
== 0);
3148 virtual bool gate (function
*) { return flag_ssa_phiopt
; }
3149 virtual unsigned int execute (function
*)
3151 return tree_ssa_phiopt_worker (false,
3152 !early_p
? gate_hoist_loads () : false,
3158 }; // class pass_phiopt
3163 make_pass_phiopt (gcc::context
*ctxt
)
3165 return new pass_phiopt (ctxt
);
3170 const pass_data pass_data_cselim
=
3172 GIMPLE_PASS
, /* type */
3173 "cselim", /* name */
3174 OPTGROUP_NONE
, /* optinfo_flags */
3175 TV_TREE_PHIOPT
, /* tv_id */
3176 ( PROP_cfg
| PROP_ssa
), /* properties_required */
3177 0, /* properties_provided */
3178 0, /* properties_destroyed */
3179 0, /* todo_flags_start */
3180 0, /* todo_flags_finish */
3183 class pass_cselim
: public gimple_opt_pass
3186 pass_cselim (gcc::context
*ctxt
)
3187 : gimple_opt_pass (pass_data_cselim
, ctxt
)
3190 /* opt_pass methods: */
3191 virtual bool gate (function
*) { return flag_tree_cselim
; }
3192 virtual unsigned int execute (function
*) { return tree_ssa_cs_elim (); }
3194 }; // class pass_cselim
3199 make_pass_cselim (gcc::context
*ctxt
)
3201 return new pass_cselim (ctxt
);