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"
51 static unsigned int tree_ssa_phiopt_worker (bool, bool, bool);
52 static bool two_value_replacement (basic_block
, basic_block
, edge
, gphi
*,
54 static bool conditional_replacement (basic_block
, basic_block
,
55 edge
, edge
, gphi
*, tree
, tree
);
56 static gphi
*factor_out_conditional_conversion (edge
, edge
, gphi
*, tree
, tree
,
58 static int value_replacement (basic_block
, basic_block
,
59 edge
, edge
, gimple
*, tree
, tree
);
60 static bool minmax_replacement (basic_block
, basic_block
,
61 edge
, edge
, gimple
*, tree
, tree
);
62 static bool abs_replacement (basic_block
, basic_block
,
63 edge
, edge
, gimple
*, tree
, tree
);
64 static bool cond_removal_in_popcount_pattern (basic_block
, basic_block
,
65 edge
, edge
, gimple
*, tree
, tree
);
66 static bool cond_store_replacement (basic_block
, basic_block
, edge
, edge
,
68 static bool cond_if_else_store_replacement (basic_block
, basic_block
, basic_block
);
69 static hash_set
<tree
> * get_non_trapping ();
70 static void replace_phi_edge_with_variable (basic_block
, edge
, gimple
*, tree
);
71 static void hoist_adjacent_loads (basic_block
, basic_block
,
72 basic_block
, basic_block
);
73 static bool gate_hoist_loads (void);
75 /* This pass tries to transform conditional stores into unconditional
76 ones, enabling further simplifications with the simpler then and else
77 blocks. In particular it replaces this:
80 if (cond) goto bb2; else goto bb1;
88 if (cond) goto bb1; else goto bb2;
92 condtmp = PHI <RHS, condtmp'>
95 This transformation can only be done under several constraints,
96 documented below. It also replaces:
99 if (cond) goto bb2; else goto bb1;
110 if (cond) goto bb3; else goto bb1;
113 condtmp = PHI <RHS1, RHS2>
117 tree_ssa_cs_elim (void)
120 /* ??? We are not interested in loop related info, but the following
121 will create it, ICEing as we didn't init loops with pre-headers.
122 An interfacing issue of find_data_references_in_bb. */
123 loop_optimizer_init (LOOPS_NORMAL
);
125 todo
= tree_ssa_phiopt_worker (true, false, false);
127 loop_optimizer_finalize ();
131 /* Return the singleton PHI in the SEQ of PHIs for edges E0 and E1. */
134 single_non_singleton_phi_for_edges (gimple_seq seq
, edge e0
, edge e1
)
136 gimple_stmt_iterator i
;
138 if (gimple_seq_singleton_p (seq
))
139 return as_a
<gphi
*> (gsi_stmt (gsi_start (seq
)));
140 for (i
= gsi_start (seq
); !gsi_end_p (i
); gsi_next (&i
))
142 gphi
*p
= as_a
<gphi
*> (gsi_stmt (i
));
143 /* If the PHI arguments are equal then we can skip this PHI. */
144 if (operand_equal_for_phi_arg_p (gimple_phi_arg_def (p
, e0
->dest_idx
),
145 gimple_phi_arg_def (p
, e1
->dest_idx
)))
148 /* If we already have a PHI that has the two edge arguments are
149 different, then return it is not a singleton for these PHIs. */
158 /* The core routine of conditional store replacement and normal
159 phi optimizations. Both share much of the infrastructure in how
160 to match applicable basic block patterns. DO_STORE_ELIM is true
161 when we want to do conditional store replacement, false otherwise.
162 DO_HOIST_LOADS is true when we want to hoist adjacent loads out
163 of diamond control flow patterns, false otherwise. */
165 tree_ssa_phiopt_worker (bool do_store_elim
, bool do_hoist_loads
, bool early_p
)
168 basic_block
*bb_order
;
170 bool cfgchanged
= false;
171 hash_set
<tree
> *nontrap
= 0;
174 /* Calculate the set of non-trapping memory accesses. */
175 nontrap
= get_non_trapping ();
177 /* Search every basic block for COND_EXPR we may be able to optimize.
179 We walk the blocks in order that guarantees that a block with
180 a single predecessor is processed before the predecessor.
181 This ensures that we collapse inner ifs before visiting the
182 outer ones, and also that we do not try to visit a removed
184 bb_order
= single_pred_before_succ_order ();
185 n
= n_basic_blocks_for_fn (cfun
) - NUM_FIXED_BLOCKS
;
187 for (i
= 0; i
< n
; i
++)
191 basic_block bb1
, bb2
;
197 cond_stmt
= last_stmt (bb
);
198 /* Check to see if the last statement is a GIMPLE_COND. */
200 || gimple_code (cond_stmt
) != GIMPLE_COND
)
203 e1
= EDGE_SUCC (bb
, 0);
205 e2
= EDGE_SUCC (bb
, 1);
208 /* We cannot do the optimization on abnormal edges. */
209 if ((e1
->flags
& EDGE_ABNORMAL
) != 0
210 || (e2
->flags
& EDGE_ABNORMAL
) != 0)
213 /* If either bb1's succ or bb2 or bb2's succ is non NULL. */
214 if (EDGE_COUNT (bb1
->succs
) == 0
216 || EDGE_COUNT (bb2
->succs
) == 0)
219 /* Find the bb which is the fall through to the other. */
220 if (EDGE_SUCC (bb1
, 0)->dest
== bb2
)
222 else if (EDGE_SUCC (bb2
, 0)->dest
== bb1
)
224 std::swap (bb1
, bb2
);
227 else if (do_store_elim
228 && EDGE_SUCC (bb1
, 0)->dest
== EDGE_SUCC (bb2
, 0)->dest
)
230 basic_block bb3
= EDGE_SUCC (bb1
, 0)->dest
;
232 if (!single_succ_p (bb1
)
233 || (EDGE_SUCC (bb1
, 0)->flags
& EDGE_FALLTHRU
) == 0
234 || !single_succ_p (bb2
)
235 || (EDGE_SUCC (bb2
, 0)->flags
& EDGE_FALLTHRU
) == 0
236 || EDGE_COUNT (bb3
->preds
) != 2)
238 if (cond_if_else_store_replacement (bb1
, bb2
, bb3
))
242 else if (do_hoist_loads
243 && EDGE_SUCC (bb1
, 0)->dest
== EDGE_SUCC (bb2
, 0)->dest
)
245 basic_block bb3
= EDGE_SUCC (bb1
, 0)->dest
;
247 if (!FLOAT_TYPE_P (TREE_TYPE (gimple_cond_lhs (cond_stmt
)))
248 && single_succ_p (bb1
)
249 && single_succ_p (bb2
)
250 && single_pred_p (bb1
)
251 && single_pred_p (bb2
)
252 && EDGE_COUNT (bb
->succs
) == 2
253 && EDGE_COUNT (bb3
->preds
) == 2
254 /* If one edge or the other is dominant, a conditional move
255 is likely to perform worse than the well-predicted branch. */
256 && !predictable_edge_p (EDGE_SUCC (bb
, 0))
257 && !predictable_edge_p (EDGE_SUCC (bb
, 1)))
258 hoist_adjacent_loads (bb
, bb1
, bb2
, bb3
);
264 e1
= EDGE_SUCC (bb1
, 0);
266 /* Make sure that bb1 is just a fall through. */
267 if (!single_succ_p (bb1
)
268 || (e1
->flags
& EDGE_FALLTHRU
) == 0)
271 /* Also make sure that bb1 only have one predecessor and that it
273 if (!single_pred_p (bb1
)
274 || single_pred (bb1
) != bb
)
279 /* bb1 is the middle block, bb2 the join block, bb the split block,
280 e1 the fallthrough edge from bb1 to bb2. We can't do the
281 optimization if the join block has more than two predecessors. */
282 if (EDGE_COUNT (bb2
->preds
) > 2)
284 if (cond_store_replacement (bb1
, bb2
, e1
, e2
, nontrap
))
289 gimple_seq phis
= phi_nodes (bb2
);
290 gimple_stmt_iterator gsi
;
291 bool candorest
= true;
293 /* Value replacement can work with more than one PHI
294 so try that first. */
296 for (gsi
= gsi_start (phis
); !gsi_end_p (gsi
); gsi_next (&gsi
))
298 phi
= as_a
<gphi
*> (gsi_stmt (gsi
));
299 arg0
= gimple_phi_arg_def (phi
, e1
->dest_idx
);
300 arg1
= gimple_phi_arg_def (phi
, e2
->dest_idx
);
301 if (value_replacement (bb
, bb1
, e1
, e2
, phi
, arg0
, arg1
) == 2)
312 phi
= single_non_singleton_phi_for_edges (phis
, e1
, e2
);
316 arg0
= gimple_phi_arg_def (phi
, e1
->dest_idx
);
317 arg1
= gimple_phi_arg_def (phi
, e2
->dest_idx
);
319 /* Something is wrong if we cannot find the arguments in the PHI
321 gcc_assert (arg0
!= NULL_TREE
&& arg1
!= NULL_TREE
);
323 gphi
*newphi
= factor_out_conditional_conversion (e1
, e2
, phi
,
329 /* factor_out_conditional_conversion may create a new PHI in
330 BB2 and eliminate an existing PHI in BB2. Recompute values
331 that may be affected by that change. */
332 arg0
= gimple_phi_arg_def (phi
, e1
->dest_idx
);
333 arg1
= gimple_phi_arg_def (phi
, e2
->dest_idx
);
334 gcc_assert (arg0
!= NULL_TREE
&& arg1
!= NULL_TREE
);
337 /* Do the replacement of conditional if it can be done. */
338 if (two_value_replacement (bb
, bb1
, e2
, phi
, arg0
, arg1
))
341 && conditional_replacement (bb
, bb1
, e1
, e2
, phi
,
344 else if (abs_replacement (bb
, bb1
, e1
, e2
, phi
, arg0
, arg1
))
347 && cond_removal_in_popcount_pattern (bb
, bb1
, e1
, e2
,
350 else if (minmax_replacement (bb
, bb1
, e1
, e2
, phi
, arg0
, arg1
))
359 /* If the CFG has changed, we should cleanup the CFG. */
360 if (cfgchanged
&& do_store_elim
)
362 /* In cond-store replacement we have added some loads on edges
363 and new VOPS (as we moved the store, and created a load). */
364 gsi_commit_edge_inserts ();
365 return TODO_cleanup_cfg
| TODO_update_ssa_only_virtuals
;
368 return TODO_cleanup_cfg
;
372 /* Replace PHI node element whose edge is E in block BB with variable NEW.
373 Remove the edge from COND_BLOCK which does not lead to BB (COND_BLOCK
374 is known to have two edges, one of which must reach BB). */
377 replace_phi_edge_with_variable (basic_block cond_block
,
378 edge e
, gimple
*phi
, tree new_tree
)
380 basic_block bb
= gimple_bb (phi
);
381 basic_block block_to_remove
;
382 gimple_stmt_iterator gsi
;
384 /* Change the PHI argument to new. */
385 SET_USE (PHI_ARG_DEF_PTR (phi
, e
->dest_idx
), new_tree
);
387 /* Remove the empty basic block. */
388 if (EDGE_SUCC (cond_block
, 0)->dest
== bb
)
390 EDGE_SUCC (cond_block
, 0)->flags
|= EDGE_FALLTHRU
;
391 EDGE_SUCC (cond_block
, 0)->flags
&= ~(EDGE_TRUE_VALUE
| EDGE_FALSE_VALUE
);
392 EDGE_SUCC (cond_block
, 0)->probability
= profile_probability::always ();
394 block_to_remove
= EDGE_SUCC (cond_block
, 1)->dest
;
398 EDGE_SUCC (cond_block
, 1)->flags
|= EDGE_FALLTHRU
;
399 EDGE_SUCC (cond_block
, 1)->flags
400 &= ~(EDGE_TRUE_VALUE
| EDGE_FALSE_VALUE
);
401 EDGE_SUCC (cond_block
, 1)->probability
= profile_probability::always ();
403 block_to_remove
= EDGE_SUCC (cond_block
, 0)->dest
;
405 delete_basic_block (block_to_remove
);
407 /* Eliminate the COND_EXPR at the end of COND_BLOCK. */
408 gsi
= gsi_last_bb (cond_block
);
409 gsi_remove (&gsi
, true);
411 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
413 "COND_EXPR in block %d and PHI in block %d converted to straightline code.\n",
418 /* PR66726: Factor conversion out of COND_EXPR. If the arguments of the PHI
419 stmt are CONVERT_STMT, factor out the conversion and perform the conversion
420 to the result of PHI stmt. COND_STMT is the controlling predicate.
421 Return the newly-created PHI, if any. */
424 factor_out_conditional_conversion (edge e0
, edge e1
, gphi
*phi
,
425 tree arg0
, tree arg1
, gimple
*cond_stmt
)
427 gimple
*arg0_def_stmt
= NULL
, *arg1_def_stmt
= NULL
, *new_stmt
;
428 tree new_arg0
= NULL_TREE
, new_arg1
= NULL_TREE
;
431 gimple_stmt_iterator gsi
, gsi_for_def
;
432 location_t locus
= gimple_location (phi
);
433 enum tree_code convert_code
;
435 /* Handle only PHI statements with two arguments. TODO: If all
436 other arguments to PHI are INTEGER_CST or if their defining
437 statement have the same unary operation, we can handle more
438 than two arguments too. */
439 if (gimple_phi_num_args (phi
) != 2)
442 /* First canonicalize to simplify tests. */
443 if (TREE_CODE (arg0
) != SSA_NAME
)
445 std::swap (arg0
, arg1
);
449 if (TREE_CODE (arg0
) != SSA_NAME
450 || (TREE_CODE (arg1
) != SSA_NAME
451 && TREE_CODE (arg1
) != INTEGER_CST
))
454 /* Check if arg0 is an SSA_NAME and the stmt which defines arg0 is
456 arg0_def_stmt
= SSA_NAME_DEF_STMT (arg0
);
457 if (!gimple_assign_cast_p (arg0_def_stmt
))
460 /* Use the RHS as new_arg0. */
461 convert_code
= gimple_assign_rhs_code (arg0_def_stmt
);
462 new_arg0
= gimple_assign_rhs1 (arg0_def_stmt
);
463 if (convert_code
== VIEW_CONVERT_EXPR
)
465 new_arg0
= TREE_OPERAND (new_arg0
, 0);
466 if (!is_gimple_reg_type (TREE_TYPE (new_arg0
)))
470 if (TREE_CODE (arg1
) == SSA_NAME
)
472 /* Check if arg1 is an SSA_NAME and the stmt which defines arg1
474 arg1_def_stmt
= SSA_NAME_DEF_STMT (arg1
);
475 if (!is_gimple_assign (arg1_def_stmt
)
476 || gimple_assign_rhs_code (arg1_def_stmt
) != convert_code
)
479 /* Use the RHS as new_arg1. */
480 new_arg1
= gimple_assign_rhs1 (arg1_def_stmt
);
481 if (convert_code
== VIEW_CONVERT_EXPR
)
482 new_arg1
= TREE_OPERAND (new_arg1
, 0);
486 /* If arg1 is an INTEGER_CST, fold it to new type. */
487 if (INTEGRAL_TYPE_P (TREE_TYPE (new_arg0
))
488 && int_fits_type_p (arg1
, TREE_TYPE (new_arg0
)))
490 if (gimple_assign_cast_p (arg0_def_stmt
))
492 /* For the INTEGER_CST case, we are just moving the
493 conversion from one place to another, which can often
494 hurt as the conversion moves further away from the
495 statement that computes the value. So, perform this
496 only if new_arg0 is an operand of COND_STMT, or
497 if arg0_def_stmt is the only non-debug stmt in
498 its basic block, because then it is possible this
499 could enable further optimizations (minmax replacement
500 etc.). See PR71016. */
501 if (new_arg0
!= gimple_cond_lhs (cond_stmt
)
502 && new_arg0
!= gimple_cond_rhs (cond_stmt
)
503 && gimple_bb (arg0_def_stmt
) == e0
->src
)
505 gsi
= gsi_for_stmt (arg0_def_stmt
);
506 gsi_prev_nondebug (&gsi
);
507 if (!gsi_end_p (gsi
))
510 = dyn_cast
<gassign
*> (gsi_stmt (gsi
)))
512 tree lhs
= gimple_assign_lhs (assign
);
513 enum tree_code ass_code
514 = gimple_assign_rhs_code (assign
);
515 if (ass_code
!= MAX_EXPR
&& ass_code
!= MIN_EXPR
)
517 if (lhs
!= gimple_assign_rhs1 (arg0_def_stmt
))
519 gsi_prev_nondebug (&gsi
);
520 if (!gsi_end_p (gsi
))
526 gsi
= gsi_for_stmt (arg0_def_stmt
);
527 gsi_next_nondebug (&gsi
);
528 if (!gsi_end_p (gsi
))
531 new_arg1
= fold_convert (TREE_TYPE (new_arg0
), arg1
);
540 /* If arg0/arg1 have > 1 use, then this transformation actually increases
541 the number of expressions evaluated at runtime. */
542 if (!has_single_use (arg0
)
543 || (arg1_def_stmt
&& !has_single_use (arg1
)))
546 /* If types of new_arg0 and new_arg1 are different bailout. */
547 if (!types_compatible_p (TREE_TYPE (new_arg0
), TREE_TYPE (new_arg1
)))
550 /* Create a new PHI stmt. */
551 result
= PHI_RESULT (phi
);
552 temp
= make_ssa_name (TREE_TYPE (new_arg0
), NULL
);
553 newphi
= create_phi_node (temp
, gimple_bb (phi
));
555 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
557 fprintf (dump_file
, "PHI ");
558 print_generic_expr (dump_file
, gimple_phi_result (phi
));
560 " changed to factor conversion out from COND_EXPR.\n");
561 fprintf (dump_file
, "New stmt with CAST that defines ");
562 print_generic_expr (dump_file
, result
);
563 fprintf (dump_file
, ".\n");
566 /* Remove the old cast(s) that has single use. */
567 gsi_for_def
= gsi_for_stmt (arg0_def_stmt
);
568 gsi_remove (&gsi_for_def
, true);
569 release_defs (arg0_def_stmt
);
573 gsi_for_def
= gsi_for_stmt (arg1_def_stmt
);
574 gsi_remove (&gsi_for_def
, true);
575 release_defs (arg1_def_stmt
);
578 add_phi_arg (newphi
, new_arg0
, e0
, locus
);
579 add_phi_arg (newphi
, new_arg1
, e1
, locus
);
581 /* Create the conversion stmt and insert it. */
582 if (convert_code
== VIEW_CONVERT_EXPR
)
584 temp
= fold_build1 (VIEW_CONVERT_EXPR
, TREE_TYPE (result
), temp
);
585 new_stmt
= gimple_build_assign (result
, temp
);
588 new_stmt
= gimple_build_assign (result
, convert_code
, temp
);
589 gsi
= gsi_after_labels (gimple_bb (phi
));
590 gsi_insert_before (&gsi
, new_stmt
, GSI_SAME_STMT
);
592 /* Remove the original PHI stmt. */
593 gsi
= gsi_for_stmt (phi
);
594 gsi_remove (&gsi
, true);
599 # x_5 in range [cst1, cst2] where cst2 = cst1 + 1
600 if (x_5 op cstN) # where op is == or != and N is 1 or 2
606 # r_6 = PHI<cst3(2), cst4(3)> # where cst3 == cst4 + 1 or cst4 == cst3 + 1
608 to r_6 = x_5 + (min (cst3, cst4) - cst1) or
609 r_6 = (min (cst3, cst4) + cst1) - x_5 depending on op, N and which
610 of cst3 and cst4 is smaller. */
613 two_value_replacement (basic_block cond_bb
, basic_block middle_bb
,
614 edge e1
, gphi
*phi
, tree arg0
, tree arg1
)
616 /* Only look for adjacent integer constants. */
617 if (!INTEGRAL_TYPE_P (TREE_TYPE (arg0
))
618 || !INTEGRAL_TYPE_P (TREE_TYPE (arg1
))
619 || TREE_CODE (arg0
) != INTEGER_CST
620 || TREE_CODE (arg1
) != INTEGER_CST
621 || (tree_int_cst_lt (arg0
, arg1
)
622 ? wi::to_widest (arg0
) + 1 != wi::to_widest (arg1
)
623 : wi::to_widest (arg1
) + 1 != wi::to_widest (arg0
)))
626 if (!empty_block_p (middle_bb
))
629 gimple
*stmt
= last_stmt (cond_bb
);
630 tree lhs
= gimple_cond_lhs (stmt
);
631 tree rhs
= gimple_cond_rhs (stmt
);
633 if (TREE_CODE (lhs
) != SSA_NAME
634 || !INTEGRAL_TYPE_P (TREE_TYPE (lhs
))
635 || TREE_CODE (TREE_TYPE (lhs
)) == BOOLEAN_TYPE
636 || TREE_CODE (rhs
) != INTEGER_CST
)
639 switch (gimple_cond_code (stmt
))
649 if (get_range_info (lhs
, &min
, &max
) != VR_RANGE
651 || (wi::to_wide (rhs
) != min
652 && wi::to_wide (rhs
) != max
))
655 /* We need to know which is the true edge and which is the false
656 edge so that we know when to invert the condition below. */
657 edge true_edge
, false_edge
;
658 extract_true_false_edges_from_block (cond_bb
, &true_edge
, &false_edge
);
659 if ((gimple_cond_code (stmt
) == EQ_EXPR
)
660 ^ (wi::to_wide (rhs
) == max
)
661 ^ (e1
== false_edge
))
662 std::swap (arg0
, arg1
);
665 if (TYPE_PRECISION (TREE_TYPE (lhs
)) == TYPE_PRECISION (TREE_TYPE (arg0
)))
667 /* Avoid performing the arithmetics in bool type which has different
668 semantics, otherwise prefer unsigned types from the two with
669 the same precision. */
670 if (TREE_CODE (TREE_TYPE (arg0
)) == BOOLEAN_TYPE
671 || !TYPE_UNSIGNED (TREE_TYPE (arg0
)))
672 type
= TREE_TYPE (lhs
);
674 type
= TREE_TYPE (arg0
);
676 else if (TYPE_PRECISION (TREE_TYPE (lhs
)) > TYPE_PRECISION (TREE_TYPE (arg0
)))
677 type
= TREE_TYPE (lhs
);
679 type
= TREE_TYPE (arg0
);
681 min
= wide_int::from (min
, TYPE_PRECISION (type
),
682 TYPE_SIGN (TREE_TYPE (lhs
)));
683 wide_int a
= wide_int::from (wi::to_wide (arg0
), TYPE_PRECISION (type
),
684 TYPE_SIGN (TREE_TYPE (arg0
)));
686 wi::overflow_type ovf
;
687 if (tree_int_cst_lt (arg0
, arg1
))
691 if (!TYPE_UNSIGNED (type
))
693 /* lhs is known to be in range [min, min+1] and we want to add a
694 to it. Check if that operation can overflow for those 2 values
695 and if yes, force unsigned type. */
696 wi::add (min
+ (wi::neg_p (a
) ? 0 : 1), a
, SIGNED
, &ovf
);
698 type
= unsigned_type_for (type
);
705 if (!TYPE_UNSIGNED (type
))
707 /* lhs is known to be in range [min, min+1] and we want to subtract
708 it from a. Check if that operation can overflow for those 2
709 values and if yes, force unsigned type. */
710 wi::sub (a
, min
+ (wi::neg_p (min
) ? 0 : 1), SIGNED
, &ovf
);
712 type
= unsigned_type_for (type
);
716 tree arg
= wide_int_to_tree (type
, a
);
717 gimple_stmt_iterator gsi
= gsi_for_stmt (stmt
);
718 if (!useless_type_conversion_p (type
, TREE_TYPE (lhs
)))
719 lhs
= gimplify_build1 (&gsi
, NOP_EXPR
, type
, lhs
);
721 if (code
== PLUS_EXPR
)
722 new_rhs
= gimplify_build2 (&gsi
, PLUS_EXPR
, type
, lhs
, arg
);
724 new_rhs
= gimplify_build2 (&gsi
, MINUS_EXPR
, type
, arg
, lhs
);
725 if (!useless_type_conversion_p (TREE_TYPE (arg0
), type
))
726 new_rhs
= gimplify_build1 (&gsi
, NOP_EXPR
, TREE_TYPE (arg0
), new_rhs
);
728 replace_phi_edge_with_variable (cond_bb
, e1
, phi
, new_rhs
);
730 /* Note that we optimized this PHI. */
734 /* The function conditional_replacement does the main work of doing the
735 conditional replacement. Return true if the replacement is done.
736 Otherwise return false.
737 BB is the basic block where the replacement is going to be done on. ARG0
738 is argument 0 from PHI. Likewise for ARG1. */
741 conditional_replacement (basic_block cond_bb
, basic_block middle_bb
,
742 edge e0
, edge e1
, gphi
*phi
,
743 tree arg0
, tree arg1
)
749 gimple_stmt_iterator gsi
;
750 edge true_edge
, false_edge
;
751 tree new_var
, new_var2
;
754 /* FIXME: Gimplification of complex type is too hard for now. */
755 /* We aren't prepared to handle vectors either (and it is a question
756 if it would be worthwhile anyway). */
757 if (!(INTEGRAL_TYPE_P (TREE_TYPE (arg0
))
758 || POINTER_TYPE_P (TREE_TYPE (arg0
)))
759 || !(INTEGRAL_TYPE_P (TREE_TYPE (arg1
))
760 || POINTER_TYPE_P (TREE_TYPE (arg1
))))
763 /* The PHI arguments have the constants 0 and 1, or 0 and -1, then
764 convert it to the conditional. */
765 if ((integer_zerop (arg0
) && integer_onep (arg1
))
766 || (integer_zerop (arg1
) && integer_onep (arg0
)))
768 else if ((integer_zerop (arg0
) && integer_all_onesp (arg1
))
769 || (integer_zerop (arg1
) && integer_all_onesp (arg0
)))
774 if (!empty_block_p (middle_bb
))
777 /* At this point we know we have a GIMPLE_COND with two successors.
778 One successor is BB, the other successor is an empty block which
779 falls through into BB.
781 There is a single PHI node at the join point (BB) and its arguments
782 are constants (0, 1) or (0, -1).
784 So, given the condition COND, and the two PHI arguments, we can
785 rewrite this PHI into non-branching code:
787 dest = (COND) or dest = COND'
789 We use the condition as-is if the argument associated with the
790 true edge has the value one or the argument associated with the
791 false edge as the value zero. Note that those conditions are not
792 the same since only one of the outgoing edges from the GIMPLE_COND
793 will directly reach BB and thus be associated with an argument. */
795 stmt
= last_stmt (cond_bb
);
796 result
= PHI_RESULT (phi
);
798 /* To handle special cases like floating point comparison, it is easier and
799 less error-prone to build a tree and gimplify it on the fly though it is
801 cond
= fold_build2_loc (gimple_location (stmt
),
802 gimple_cond_code (stmt
), boolean_type_node
,
803 gimple_cond_lhs (stmt
), gimple_cond_rhs (stmt
));
805 /* We need to know which is the true edge and which is the false
806 edge so that we know when to invert the condition below. */
807 extract_true_false_edges_from_block (cond_bb
, &true_edge
, &false_edge
);
808 if ((e0
== true_edge
&& integer_zerop (arg0
))
809 || (e0
== false_edge
&& !integer_zerop (arg0
))
810 || (e1
== true_edge
&& integer_zerop (arg1
))
811 || (e1
== false_edge
&& !integer_zerop (arg1
)))
812 cond
= fold_build1_loc (gimple_location (stmt
),
813 TRUTH_NOT_EXPR
, TREE_TYPE (cond
), cond
);
817 cond
= fold_convert_loc (gimple_location (stmt
),
818 TREE_TYPE (result
), cond
);
819 cond
= fold_build1_loc (gimple_location (stmt
),
820 NEGATE_EXPR
, TREE_TYPE (cond
), cond
);
823 /* Insert our new statements at the end of conditional block before the
825 gsi
= gsi_for_stmt (stmt
);
826 new_var
= force_gimple_operand_gsi (&gsi
, cond
, true, NULL
, true,
829 if (!useless_type_conversion_p (TREE_TYPE (result
), TREE_TYPE (new_var
)))
831 location_t locus_0
, locus_1
;
833 new_var2
= make_ssa_name (TREE_TYPE (result
));
834 new_stmt
= gimple_build_assign (new_var2
, CONVERT_EXPR
, new_var
);
835 gsi_insert_before (&gsi
, new_stmt
, GSI_SAME_STMT
);
838 /* Set the locus to the first argument, unless is doesn't have one. */
839 locus_0
= gimple_phi_arg_location (phi
, 0);
840 locus_1
= gimple_phi_arg_location (phi
, 1);
841 if (locus_0
== UNKNOWN_LOCATION
)
843 gimple_set_location (new_stmt
, locus_0
);
846 replace_phi_edge_with_variable (cond_bb
, e1
, phi
, new_var
);
848 /* Note that we optimized this PHI. */
852 /* Update *ARG which is defined in STMT so that it contains the
853 computed value if that seems profitable. Return true if the
854 statement is made dead by that rewriting. */
857 jump_function_from_stmt (tree
*arg
, gimple
*stmt
)
859 enum tree_code code
= gimple_assign_rhs_code (stmt
);
860 if (code
== ADDR_EXPR
)
862 /* For arg = &p->i transform it to p, if possible. */
863 tree rhs1
= gimple_assign_rhs1 (stmt
);
865 tree tem
= get_addr_base_and_unit_offset (TREE_OPERAND (rhs1
, 0),
868 && TREE_CODE (tem
) == MEM_REF
869 && known_eq (mem_ref_offset (tem
) + offset
, 0))
871 *arg
= TREE_OPERAND (tem
, 0);
875 /* TODO: Much like IPA-CP jump-functions we want to handle constant
876 additions symbolically here, and we'd need to update the comparison
877 code that compares the arg + cst tuples in our caller. For now the
878 code above exactly handles the VEC_BASE pattern from vec.h. */
882 /* RHS is a source argument in a BIT_AND_EXPR which feeds a conditional
883 of the form SSA_NAME NE 0.
885 If RHS is fed by a simple EQ_EXPR comparison of two values, see if
886 the two input values of the EQ_EXPR match arg0 and arg1.
888 If so update *code and return TRUE. Otherwise return FALSE. */
891 rhs_is_fed_for_value_replacement (const_tree arg0
, const_tree arg1
,
892 enum tree_code
*code
, const_tree rhs
)
894 /* Obviously if RHS is not an SSA_NAME, we can't look at the defining
896 if (TREE_CODE (rhs
) == SSA_NAME
)
898 gimple
*def1
= SSA_NAME_DEF_STMT (rhs
);
900 /* Verify the defining statement has an EQ_EXPR on the RHS. */
901 if (is_gimple_assign (def1
) && gimple_assign_rhs_code (def1
) == EQ_EXPR
)
903 /* Finally verify the source operands of the EQ_EXPR are equal
905 tree op0
= gimple_assign_rhs1 (def1
);
906 tree op1
= gimple_assign_rhs2 (def1
);
907 if ((operand_equal_for_phi_arg_p (arg0
, op0
)
908 && operand_equal_for_phi_arg_p (arg1
, op1
))
909 || (operand_equal_for_phi_arg_p (arg0
, op1
)
910 && operand_equal_for_phi_arg_p (arg1
, op0
)))
912 /* We will perform the optimization. */
913 *code
= gimple_assign_rhs_code (def1
);
921 /* Return TRUE if arg0/arg1 are equal to the rhs/lhs or lhs/rhs of COND.
923 Also return TRUE if arg0/arg1 are equal to the source arguments of a
924 an EQ comparison feeding a BIT_AND_EXPR which feeds COND.
926 Return FALSE otherwise. */
929 operand_equal_for_value_replacement (const_tree arg0
, const_tree arg1
,
930 enum tree_code
*code
, gimple
*cond
)
933 tree lhs
= gimple_cond_lhs (cond
);
934 tree rhs
= gimple_cond_rhs (cond
);
936 if ((operand_equal_for_phi_arg_p (arg0
, lhs
)
937 && operand_equal_for_phi_arg_p (arg1
, rhs
))
938 || (operand_equal_for_phi_arg_p (arg1
, lhs
)
939 && operand_equal_for_phi_arg_p (arg0
, rhs
)))
942 /* Now handle more complex case where we have an EQ comparison
943 which feeds a BIT_AND_EXPR which feeds COND.
945 First verify that COND is of the form SSA_NAME NE 0. */
946 if (*code
!= NE_EXPR
|| !integer_zerop (rhs
)
947 || TREE_CODE (lhs
) != SSA_NAME
)
950 /* Now ensure that SSA_NAME is set by a BIT_AND_EXPR. */
951 def
= SSA_NAME_DEF_STMT (lhs
);
952 if (!is_gimple_assign (def
) || gimple_assign_rhs_code (def
) != BIT_AND_EXPR
)
955 /* Now verify arg0/arg1 correspond to the source arguments of an
956 EQ comparison feeding the BIT_AND_EXPR. */
958 tree tmp
= gimple_assign_rhs1 (def
);
959 if (rhs_is_fed_for_value_replacement (arg0
, arg1
, code
, tmp
))
962 tmp
= gimple_assign_rhs2 (def
);
963 if (rhs_is_fed_for_value_replacement (arg0
, arg1
, code
, tmp
))
969 /* Returns true if ARG is a neutral element for operation CODE
970 on the RIGHT side. */
973 neutral_element_p (tree_code code
, tree arg
, bool right
)
980 return integer_zerop (arg
);
987 case POINTER_PLUS_EXPR
:
988 return right
&& integer_zerop (arg
);
991 return integer_onep (arg
);
998 return right
&& integer_onep (arg
);
1001 return integer_all_onesp (arg
);
1008 /* Returns true if ARG is an absorbing element for operation CODE. */
1011 absorbing_element_p (tree_code code
, tree arg
, bool right
, tree rval
)
1016 return integer_all_onesp (arg
);
1020 return integer_zerop (arg
);
1026 return !right
&& integer_zerop (arg
);
1028 case TRUNC_DIV_EXPR
:
1030 case FLOOR_DIV_EXPR
:
1031 case ROUND_DIV_EXPR
:
1032 case EXACT_DIV_EXPR
:
1033 case TRUNC_MOD_EXPR
:
1035 case FLOOR_MOD_EXPR
:
1036 case ROUND_MOD_EXPR
:
1038 && integer_zerop (arg
)
1039 && tree_single_nonzero_warnv_p (rval
, NULL
));
1046 /* The function value_replacement does the main work of doing the value
1047 replacement. Return non-zero if the replacement is done. Otherwise return
1048 0. If we remove the middle basic block, return 2.
1049 BB is the basic block where the replacement is going to be done on. ARG0
1050 is argument 0 from the PHI. Likewise for ARG1. */
1053 value_replacement (basic_block cond_bb
, basic_block middle_bb
,
1054 edge e0
, edge e1
, gimple
*phi
,
1055 tree arg0
, tree arg1
)
1057 gimple_stmt_iterator gsi
;
1059 edge true_edge
, false_edge
;
1060 enum tree_code code
;
1061 bool empty_or_with_defined_p
= true;
1063 /* If the type says honor signed zeros we cannot do this
1065 if (HONOR_SIGNED_ZEROS (arg1
))
1068 /* If there is a statement in MIDDLE_BB that defines one of the PHI
1069 arguments, then adjust arg0 or arg1. */
1070 gsi
= gsi_start_nondebug_after_labels_bb (middle_bb
);
1071 while (!gsi_end_p (gsi
))
1073 gimple
*stmt
= gsi_stmt (gsi
);
1075 gsi_next_nondebug (&gsi
);
1076 if (!is_gimple_assign (stmt
))
1078 if (gimple_code (stmt
) != GIMPLE_PREDICT
1079 && gimple_code (stmt
) != GIMPLE_NOP
)
1080 empty_or_with_defined_p
= false;
1083 /* Now try to adjust arg0 or arg1 according to the computation
1084 in the statement. */
1085 lhs
= gimple_assign_lhs (stmt
);
1087 && jump_function_from_stmt (&arg0
, stmt
))
1089 && jump_function_from_stmt (&arg1
, stmt
)))
1090 empty_or_with_defined_p
= false;
1093 cond
= last_stmt (cond_bb
);
1094 code
= gimple_cond_code (cond
);
1096 /* This transformation is only valid for equality comparisons. */
1097 if (code
!= NE_EXPR
&& code
!= EQ_EXPR
)
1100 /* We need to know which is the true edge and which is the false
1101 edge so that we know if have abs or negative abs. */
1102 extract_true_false_edges_from_block (cond_bb
, &true_edge
, &false_edge
);
1104 /* At this point we know we have a COND_EXPR with two successors.
1105 One successor is BB, the other successor is an empty block which
1106 falls through into BB.
1108 The condition for the COND_EXPR is known to be NE_EXPR or EQ_EXPR.
1110 There is a single PHI node at the join point (BB) with two arguments.
1112 We now need to verify that the two arguments in the PHI node match
1113 the two arguments to the equality comparison. */
1115 if (operand_equal_for_value_replacement (arg0
, arg1
, &code
, cond
))
1120 /* For NE_EXPR, we want to build an assignment result = arg where
1121 arg is the PHI argument associated with the true edge. For
1122 EQ_EXPR we want the PHI argument associated with the false edge. */
1123 e
= (code
== NE_EXPR
? true_edge
: false_edge
);
1125 /* Unfortunately, E may not reach BB (it may instead have gone to
1126 OTHER_BLOCK). If that is the case, then we want the single outgoing
1127 edge from OTHER_BLOCK which reaches BB and represents the desired
1128 path from COND_BLOCK. */
1129 if (e
->dest
== middle_bb
)
1130 e
= single_succ_edge (e
->dest
);
1132 /* Now we know the incoming edge to BB that has the argument for the
1133 RHS of our new assignment statement. */
1139 /* If the middle basic block was empty or is defining the
1140 PHI arguments and this is a single phi where the args are different
1141 for the edges e0 and e1 then we can remove the middle basic block. */
1142 if (empty_or_with_defined_p
1143 && single_non_singleton_phi_for_edges (phi_nodes (gimple_bb (phi
)),
1146 replace_phi_edge_with_variable (cond_bb
, e1
, phi
, arg
);
1147 /* Note that we optimized this PHI. */
1152 /* Replace the PHI arguments with arg. */
1153 SET_PHI_ARG_DEF (phi
, e0
->dest_idx
, arg
);
1154 SET_PHI_ARG_DEF (phi
, e1
->dest_idx
, arg
);
1155 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
1157 fprintf (dump_file
, "PHI ");
1158 print_generic_expr (dump_file
, gimple_phi_result (phi
));
1159 fprintf (dump_file
, " reduced for COND_EXPR in block %d to ",
1161 print_generic_expr (dump_file
, arg
);
1162 fprintf (dump_file
, ".\n");
1169 /* Now optimize (x != 0) ? x + y : y to just x + y. */
1170 gsi
= gsi_last_nondebug_bb (middle_bb
);
1171 if (gsi_end_p (gsi
))
1174 gimple
*assign
= gsi_stmt (gsi
);
1175 if (!is_gimple_assign (assign
)
1176 || gimple_assign_rhs_class (assign
) != GIMPLE_BINARY_RHS
1177 || (!INTEGRAL_TYPE_P (TREE_TYPE (arg0
))
1178 && !POINTER_TYPE_P (TREE_TYPE (arg0
))))
1181 /* Punt if there are (degenerate) PHIs in middle_bb, there should not be. */
1182 if (!gimple_seq_empty_p (phi_nodes (middle_bb
)))
1185 /* Allow up to 2 cheap preparation statements that prepare argument
1193 iftmp.0_6 = x_5(D) r<< _1;
1195 # iftmp.0_2 = PHI <iftmp.0_6(3), x_5(D)(2)>
1206 # _2 = PHI <x_5(D)(2), _6(3)> */
1207 gimple
*prep_stmt
[2] = { NULL
, NULL
};
1209 for (prep_cnt
= 0; ; prep_cnt
++)
1211 gsi_prev_nondebug (&gsi
);
1212 if (gsi_end_p (gsi
))
1215 gimple
*g
= gsi_stmt (gsi
);
1216 if (gimple_code (g
) == GIMPLE_LABEL
)
1219 if (prep_cnt
== 2 || !is_gimple_assign (g
))
1222 tree lhs
= gimple_assign_lhs (g
);
1223 tree rhs1
= gimple_assign_rhs1 (g
);
1224 use_operand_p use_p
;
1226 if (TREE_CODE (lhs
) != SSA_NAME
1227 || TREE_CODE (rhs1
) != SSA_NAME
1228 || !INTEGRAL_TYPE_P (TREE_TYPE (lhs
))
1229 || !INTEGRAL_TYPE_P (TREE_TYPE (rhs1
))
1230 || !single_imm_use (lhs
, &use_p
, &use_stmt
)
1231 || use_stmt
!= (prep_cnt
? prep_stmt
[prep_cnt
- 1] : assign
))
1233 switch (gimple_assign_rhs_code (g
))
1241 if (TREE_CODE (gimple_assign_rhs2 (g
)) != INTEGER_CST
)
1247 prep_stmt
[prep_cnt
] = g
;
1250 /* Only transform if it removes the condition. */
1251 if (!single_non_singleton_phi_for_edges (phi_nodes (gimple_bb (phi
)), e0
, e1
))
1254 /* Size-wise, this is always profitable. */
1255 if (optimize_bb_for_speed_p (cond_bb
)
1256 /* The special case is useless if it has a low probability. */
1257 && profile_status_for_fn (cfun
) != PROFILE_ABSENT
1258 && EDGE_PRED (middle_bb
, 0)->probability
< profile_probability::even ()
1259 /* If assign is cheap, there is no point avoiding it. */
1260 && estimate_num_insns_seq (bb_seq (middle_bb
), &eni_time_weights
)
1261 >= 3 * estimate_num_insns (cond
, &eni_time_weights
))
1264 tree lhs
= gimple_assign_lhs (assign
);
1265 tree rhs1
= gimple_assign_rhs1 (assign
);
1266 tree rhs2
= gimple_assign_rhs2 (assign
);
1267 enum tree_code code_def
= gimple_assign_rhs_code (assign
);
1268 tree cond_lhs
= gimple_cond_lhs (cond
);
1269 tree cond_rhs
= gimple_cond_rhs (cond
);
1271 /* Propagate the cond_rhs constant through preparation stmts,
1272 make sure UB isn't invoked while doing that. */
1273 for (int i
= prep_cnt
- 1; i
>= 0; --i
)
1275 gimple
*g
= prep_stmt
[i
];
1276 tree grhs1
= gimple_assign_rhs1 (g
);
1277 if (!operand_equal_for_phi_arg_p (cond_lhs
, grhs1
))
1279 cond_lhs
= gimple_assign_lhs (g
);
1280 cond_rhs
= fold_convert (TREE_TYPE (grhs1
), cond_rhs
);
1281 if (TREE_CODE (cond_rhs
) != INTEGER_CST
1282 || TREE_OVERFLOW (cond_rhs
))
1284 if (gimple_assign_rhs_class (g
) == GIMPLE_BINARY_RHS
)
1286 cond_rhs
= int_const_binop (gimple_assign_rhs_code (g
), cond_rhs
,
1287 gimple_assign_rhs2 (g
));
1288 if (TREE_OVERFLOW (cond_rhs
))
1291 cond_rhs
= fold_convert (TREE_TYPE (cond_lhs
), cond_rhs
);
1292 if (TREE_CODE (cond_rhs
) != INTEGER_CST
1293 || TREE_OVERFLOW (cond_rhs
))
1297 if (((code
== NE_EXPR
&& e1
== false_edge
)
1298 || (code
== EQ_EXPR
&& e1
== true_edge
))
1301 && operand_equal_for_phi_arg_p (rhs2
, cond_lhs
)
1302 && neutral_element_p (code_def
, cond_rhs
, true))
1304 && operand_equal_for_phi_arg_p (rhs1
, cond_lhs
)
1305 && neutral_element_p (code_def
, cond_rhs
, false))
1306 || (operand_equal_for_phi_arg_p (arg1
, cond_rhs
)
1307 && ((operand_equal_for_phi_arg_p (rhs2
, cond_lhs
)
1308 && absorbing_element_p (code_def
, cond_rhs
, true, rhs2
))
1309 || (operand_equal_for_phi_arg_p (rhs1
, cond_lhs
)
1310 && absorbing_element_p (code_def
,
1311 cond_rhs
, false, rhs2
))))))
1313 gsi
= gsi_for_stmt (cond
);
1314 /* Moving ASSIGN might change VR of lhs, e.g. when moving u_6
1322 # RANGE [0, 4294967294]
1323 u_6 = n_5 + 4294967295;
1326 # u_3 = PHI <u_6(3), 4294967295(2)> */
1327 reset_flow_sensitive_info (lhs
);
1328 if (INTEGRAL_TYPE_P (TREE_TYPE (lhs
)))
1330 /* If available, we can use VR of phi result at least. */
1331 tree phires
= gimple_phi_result (phi
);
1332 struct range_info_def
*phires_range_info
1333 = SSA_NAME_RANGE_INFO (phires
);
1334 if (phires_range_info
)
1335 duplicate_ssa_name_range_info (lhs
, SSA_NAME_RANGE_TYPE (phires
),
1338 gimple_stmt_iterator gsi_from
;
1339 for (int i
= prep_cnt
- 1; i
>= 0; --i
)
1341 tree plhs
= gimple_assign_lhs (prep_stmt
[i
]);
1342 reset_flow_sensitive_info (plhs
);
1343 gsi_from
= gsi_for_stmt (prep_stmt
[i
]);
1344 gsi_move_before (&gsi_from
, &gsi
);
1346 gsi_from
= gsi_for_stmt (assign
);
1347 gsi_move_before (&gsi_from
, &gsi
);
1348 replace_phi_edge_with_variable (cond_bb
, e1
, phi
, lhs
);
1355 /* The function minmax_replacement does the main work of doing the minmax
1356 replacement. Return true if the replacement is done. Otherwise return
1358 BB is the basic block where the replacement is going to be done on. ARG0
1359 is argument 0 from the PHI. Likewise for ARG1. */
1362 minmax_replacement (basic_block cond_bb
, basic_block middle_bb
,
1363 edge e0
, edge e1
, gimple
*phi
,
1364 tree arg0
, tree arg1
)
1367 edge true_edge
, false_edge
;
1368 enum tree_code minmax
, ass_code
;
1369 tree smaller
, larger
, arg_true
, arg_false
;
1370 gimple_stmt_iterator gsi
, gsi_from
;
1372 tree type
= TREE_TYPE (PHI_RESULT (phi
));
1374 /* The optimization may be unsafe due to NaNs. */
1375 if (HONOR_NANS (type
) || HONOR_SIGNED_ZEROS (type
))
1378 gcond
*cond
= as_a
<gcond
*> (last_stmt (cond_bb
));
1379 enum tree_code cmp
= gimple_cond_code (cond
);
1380 tree rhs
= gimple_cond_rhs (cond
);
1382 /* Turn EQ/NE of extreme values to order comparisons. */
1383 if ((cmp
== NE_EXPR
|| cmp
== EQ_EXPR
)
1384 && TREE_CODE (rhs
) == INTEGER_CST
1385 && INTEGRAL_TYPE_P (TREE_TYPE (rhs
)))
1387 if (wi::eq_p (wi::to_wide (rhs
), wi::min_value (TREE_TYPE (rhs
))))
1389 cmp
= (cmp
== EQ_EXPR
) ? LT_EXPR
: GE_EXPR
;
1390 rhs
= wide_int_to_tree (TREE_TYPE (rhs
),
1391 wi::min_value (TREE_TYPE (rhs
)) + 1);
1393 else if (wi::eq_p (wi::to_wide (rhs
), wi::max_value (TREE_TYPE (rhs
))))
1395 cmp
= (cmp
== EQ_EXPR
) ? GT_EXPR
: LE_EXPR
;
1396 rhs
= wide_int_to_tree (TREE_TYPE (rhs
),
1397 wi::max_value (TREE_TYPE (rhs
)) - 1);
1401 /* This transformation is only valid for order comparisons. Record which
1402 operand is smaller/larger if the result of the comparison is true. */
1403 tree alt_smaller
= NULL_TREE
;
1404 tree alt_larger
= NULL_TREE
;
1405 if (cmp
== LT_EXPR
|| cmp
== LE_EXPR
)
1407 smaller
= gimple_cond_lhs (cond
);
1409 /* If we have smaller < CST it is equivalent to smaller <= CST-1.
1410 Likewise smaller <= CST is equivalent to smaller < CST+1. */
1411 if (TREE_CODE (larger
) == INTEGER_CST
1412 && INTEGRAL_TYPE_P (TREE_TYPE (larger
)))
1416 wi::overflow_type overflow
;
1417 wide_int alt
= wi::sub (wi::to_wide (larger
), 1,
1418 TYPE_SIGN (TREE_TYPE (larger
)),
1421 alt_larger
= wide_int_to_tree (TREE_TYPE (larger
), alt
);
1425 wi::overflow_type overflow
;
1426 wide_int alt
= wi::add (wi::to_wide (larger
), 1,
1427 TYPE_SIGN (TREE_TYPE (larger
)),
1430 alt_larger
= wide_int_to_tree (TREE_TYPE (larger
), alt
);
1434 else if (cmp
== GT_EXPR
|| cmp
== GE_EXPR
)
1437 larger
= gimple_cond_lhs (cond
);
1438 /* If we have larger > CST it is equivalent to larger >= CST+1.
1439 Likewise larger >= CST is equivalent to larger > CST-1. */
1440 if (TREE_CODE (smaller
) == INTEGER_CST
1441 && INTEGRAL_TYPE_P (TREE_TYPE (smaller
)))
1443 wi::overflow_type overflow
;
1446 wide_int alt
= wi::add (wi::to_wide (smaller
), 1,
1447 TYPE_SIGN (TREE_TYPE (smaller
)),
1450 alt_smaller
= wide_int_to_tree (TREE_TYPE (smaller
), alt
);
1454 wide_int alt
= wi::sub (wi::to_wide (smaller
), 1,
1455 TYPE_SIGN (TREE_TYPE (smaller
)),
1458 alt_smaller
= wide_int_to_tree (TREE_TYPE (smaller
), alt
);
1465 /* Handle the special case of (signed_type)x < 0 being equivalent
1466 to x > MAX_VAL(signed_type) and (signed_type)x >= 0 equivalent
1467 to x <= MAX_VAL(signed_type). */
1468 if ((cmp
== GE_EXPR
|| cmp
== LT_EXPR
)
1469 && INTEGRAL_TYPE_P (type
)
1470 && TYPE_UNSIGNED (type
)
1471 && integer_zerop (rhs
))
1473 tree op
= gimple_cond_lhs (cond
);
1474 if (TREE_CODE (op
) == SSA_NAME
1475 && INTEGRAL_TYPE_P (TREE_TYPE (op
))
1476 && !TYPE_UNSIGNED (TREE_TYPE (op
)))
1478 gimple
*def_stmt
= SSA_NAME_DEF_STMT (op
);
1479 if (gimple_assign_cast_p (def_stmt
))
1481 tree op1
= gimple_assign_rhs1 (def_stmt
);
1482 if (INTEGRAL_TYPE_P (TREE_TYPE (op1
))
1483 && TYPE_UNSIGNED (TREE_TYPE (op1
))
1484 && (TYPE_PRECISION (TREE_TYPE (op
))
1485 == TYPE_PRECISION (TREE_TYPE (op1
)))
1486 && useless_type_conversion_p (type
, TREE_TYPE (op1
)))
1488 wide_int w1
= wi::max_value (TREE_TYPE (op
));
1489 wide_int w2
= wi::add (w1
, 1);
1493 smaller
= wide_int_to_tree (TREE_TYPE (op1
), w1
);
1494 alt_smaller
= wide_int_to_tree (TREE_TYPE (op1
), w2
);
1495 alt_larger
= NULL_TREE
;
1500 larger
= wide_int_to_tree (TREE_TYPE (op1
), w1
);
1501 alt_larger
= wide_int_to_tree (TREE_TYPE (op1
), w2
);
1502 alt_smaller
= NULL_TREE
;
1509 /* We need to know which is the true edge and which is the false
1510 edge so that we know if have abs or negative abs. */
1511 extract_true_false_edges_from_block (cond_bb
, &true_edge
, &false_edge
);
1513 /* Forward the edges over the middle basic block. */
1514 if (true_edge
->dest
== middle_bb
)
1515 true_edge
= EDGE_SUCC (true_edge
->dest
, 0);
1516 if (false_edge
->dest
== middle_bb
)
1517 false_edge
= EDGE_SUCC (false_edge
->dest
, 0);
1519 if (true_edge
== e0
)
1521 gcc_assert (false_edge
== e1
);
1527 gcc_assert (false_edge
== e0
);
1528 gcc_assert (true_edge
== e1
);
1533 if (empty_block_p (middle_bb
))
1535 if ((operand_equal_for_phi_arg_p (arg_true
, smaller
)
1537 && operand_equal_for_phi_arg_p (arg_true
, alt_smaller
)))
1538 && (operand_equal_for_phi_arg_p (arg_false
, larger
)
1540 && operand_equal_for_phi_arg_p (arg_true
, alt_larger
))))
1544 if (smaller < larger)
1550 else if ((operand_equal_for_phi_arg_p (arg_false
, smaller
)
1552 && operand_equal_for_phi_arg_p (arg_false
, alt_smaller
)))
1553 && (operand_equal_for_phi_arg_p (arg_true
, larger
)
1555 && operand_equal_for_phi_arg_p (arg_true
, alt_larger
))))
1562 /* Recognize the following case, assuming d <= u:
1568 This is equivalent to
1573 gimple
*assign
= last_and_only_stmt (middle_bb
);
1574 tree lhs
, op0
, op1
, bound
;
1577 || gimple_code (assign
) != GIMPLE_ASSIGN
)
1580 lhs
= gimple_assign_lhs (assign
);
1581 ass_code
= gimple_assign_rhs_code (assign
);
1582 if (ass_code
!= MAX_EXPR
&& ass_code
!= MIN_EXPR
)
1584 op0
= gimple_assign_rhs1 (assign
);
1585 op1
= gimple_assign_rhs2 (assign
);
1587 if (true_edge
->src
== middle_bb
)
1589 /* We got here if the condition is true, i.e., SMALLER < LARGER. */
1590 if (!operand_equal_for_phi_arg_p (lhs
, arg_true
))
1593 if (operand_equal_for_phi_arg_p (arg_false
, larger
)
1595 && operand_equal_for_phi_arg_p (arg_false
, alt_larger
)))
1599 if (smaller < larger)
1601 r' = MAX_EXPR (smaller, bound)
1603 r = PHI <r', larger> --> to be turned to MIN_EXPR. */
1604 if (ass_code
!= MAX_EXPR
)
1608 if (operand_equal_for_phi_arg_p (op0
, smaller
)
1610 && operand_equal_for_phi_arg_p (op0
, alt_smaller
)))
1612 else if (operand_equal_for_phi_arg_p (op1
, smaller
)
1614 && operand_equal_for_phi_arg_p (op1
, alt_smaller
)))
1619 /* We need BOUND <= LARGER. */
1620 if (!integer_nonzerop (fold_build2 (LE_EXPR
, boolean_type_node
,
1624 else if (operand_equal_for_phi_arg_p (arg_false
, smaller
)
1626 && operand_equal_for_phi_arg_p (arg_false
, alt_smaller
)))
1630 if (smaller < larger)
1632 r' = MIN_EXPR (larger, bound)
1634 r = PHI <r', smaller> --> to be turned to MAX_EXPR. */
1635 if (ass_code
!= MIN_EXPR
)
1639 if (operand_equal_for_phi_arg_p (op0
, larger
)
1641 && operand_equal_for_phi_arg_p (op0
, alt_larger
)))
1643 else if (operand_equal_for_phi_arg_p (op1
, larger
)
1645 && operand_equal_for_phi_arg_p (op1
, alt_larger
)))
1650 /* We need BOUND >= SMALLER. */
1651 if (!integer_nonzerop (fold_build2 (GE_EXPR
, boolean_type_node
,
1660 /* We got here if the condition is false, i.e., SMALLER > LARGER. */
1661 if (!operand_equal_for_phi_arg_p (lhs
, arg_false
))
1664 if (operand_equal_for_phi_arg_p (arg_true
, larger
)
1666 && operand_equal_for_phi_arg_p (arg_true
, alt_larger
)))
1670 if (smaller > larger)
1672 r' = MIN_EXPR (smaller, bound)
1674 r = PHI <r', larger> --> to be turned to MAX_EXPR. */
1675 if (ass_code
!= MIN_EXPR
)
1679 if (operand_equal_for_phi_arg_p (op0
, smaller
)
1681 && operand_equal_for_phi_arg_p (op0
, alt_smaller
)))
1683 else if (operand_equal_for_phi_arg_p (op1
, smaller
)
1685 && operand_equal_for_phi_arg_p (op1
, alt_smaller
)))
1690 /* We need BOUND >= LARGER. */
1691 if (!integer_nonzerop (fold_build2 (GE_EXPR
, boolean_type_node
,
1695 else if (operand_equal_for_phi_arg_p (arg_true
, smaller
)
1697 && operand_equal_for_phi_arg_p (arg_true
, alt_smaller
)))
1701 if (smaller > larger)
1703 r' = MAX_EXPR (larger, bound)
1705 r = PHI <r', smaller> --> to be turned to MIN_EXPR. */
1706 if (ass_code
!= MAX_EXPR
)
1710 if (operand_equal_for_phi_arg_p (op0
, larger
))
1712 else if (operand_equal_for_phi_arg_p (op1
, larger
))
1717 /* We need BOUND <= SMALLER. */
1718 if (!integer_nonzerop (fold_build2 (LE_EXPR
, boolean_type_node
,
1726 /* Move the statement from the middle block. */
1727 gsi
= gsi_last_bb (cond_bb
);
1728 gsi_from
= gsi_last_nondebug_bb (middle_bb
);
1729 reset_flow_sensitive_info (SINGLE_SSA_TREE_OPERAND (gsi_stmt (gsi_from
),
1731 gsi_move_before (&gsi_from
, &gsi
);
1734 /* Emit the statement to compute min/max. */
1735 gimple_seq stmts
= NULL
;
1736 tree phi_result
= PHI_RESULT (phi
);
1737 result
= gimple_build (&stmts
, minmax
, TREE_TYPE (phi_result
), arg0
, arg1
);
1738 /* Duplicate range info if we're the only things setting the target PHI. */
1739 if (!gimple_seq_empty_p (stmts
)
1740 && EDGE_COUNT (gimple_bb (phi
)->preds
) == 2
1741 && !POINTER_TYPE_P (TREE_TYPE (phi_result
))
1742 && SSA_NAME_RANGE_INFO (phi_result
))
1743 duplicate_ssa_name_range_info (result
, SSA_NAME_RANGE_TYPE (phi_result
),
1744 SSA_NAME_RANGE_INFO (phi_result
));
1746 gsi
= gsi_last_bb (cond_bb
);
1747 gsi_insert_seq_before (&gsi
, stmts
, GSI_NEW_STMT
);
1749 replace_phi_edge_with_variable (cond_bb
, e1
, phi
, result
);
1763 _2 = (unsigned long) b_4(D);
1764 _9 = __builtin_popcountl (_2);
1766 _9 = __builtin_popcountl (b_4(D));
1769 c_12 = PHI <0(2), _9(3)>
1773 _2 = (unsigned long) b_4(D);
1774 _9 = __builtin_popcountl (_2);
1776 _9 = __builtin_popcountl (b_4(D));
1783 cond_removal_in_popcount_pattern (basic_block cond_bb
, basic_block middle_bb
,
1785 gimple
*phi
, tree arg0
, tree arg1
)
1788 gimple_stmt_iterator gsi
, gsi_from
;
1790 gimple
*cast
= NULL
;
1794 _2 = (unsigned long) b_4(D);
1795 _9 = __builtin_popcountl (_2);
1797 _9 = __builtin_popcountl (b_4(D));
1798 are the only stmts in the middle_bb. */
1800 gsi
= gsi_start_nondebug_after_labels_bb (middle_bb
);
1801 if (gsi_end_p (gsi
))
1803 cast
= gsi_stmt (gsi
);
1804 gsi_next_nondebug (&gsi
);
1805 if (!gsi_end_p (gsi
))
1807 popcount
= gsi_stmt (gsi
);
1808 gsi_next_nondebug (&gsi
);
1809 if (!gsi_end_p (gsi
))
1818 /* Check that we have a popcount builtin. */
1819 if (!is_gimple_call (popcount
))
1821 combined_fn cfn
= gimple_call_combined_fn (popcount
);
1830 arg
= gimple_call_arg (popcount
, 0);
1831 lhs
= gimple_get_lhs (popcount
);
1835 /* We have a cast stmt feeding popcount builtin. */
1836 /* Check that we have a cast prior to that. */
1837 if (gimple_code (cast
) != GIMPLE_ASSIGN
1838 || !CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (cast
)))
1840 /* Result of the cast stmt is the argument to the builtin. */
1841 if (arg
!= gimple_assign_lhs (cast
))
1843 arg
= gimple_assign_rhs1 (cast
);
1846 cond
= last_stmt (cond_bb
);
1848 /* Cond_bb has a check for b_4 [!=|==] 0 before calling the popcount
1850 if (gimple_code (cond
) != GIMPLE_COND
1851 || (gimple_cond_code (cond
) != NE_EXPR
1852 && gimple_cond_code (cond
) != EQ_EXPR
)
1853 || !integer_zerop (gimple_cond_rhs (cond
))
1854 || arg
!= gimple_cond_lhs (cond
))
1858 if ((e2
->flags
& EDGE_TRUE_VALUE
1859 && gimple_cond_code (cond
) == NE_EXPR
)
1860 || (e1
->flags
& EDGE_TRUE_VALUE
1861 && gimple_cond_code (cond
) == EQ_EXPR
))
1863 std::swap (arg0
, arg1
);
1867 /* Check PHI arguments. */
1868 if (lhs
!= arg0
|| !integer_zerop (arg1
))
1871 /* And insert the popcount builtin and cast stmt before the cond_bb. */
1872 gsi
= gsi_last_bb (cond_bb
);
1875 gsi_from
= gsi_for_stmt (cast
);
1876 gsi_move_before (&gsi_from
, &gsi
);
1877 reset_flow_sensitive_info (gimple_get_lhs (cast
));
1879 gsi_from
= gsi_for_stmt (popcount
);
1880 gsi_move_before (&gsi_from
, &gsi
);
1881 reset_flow_sensitive_info (gimple_get_lhs (popcount
));
1883 /* Now update the PHI and remove unneeded bbs. */
1884 replace_phi_edge_with_variable (cond_bb
, e2
, phi
, lhs
);
1888 /* The function absolute_replacement does the main work of doing the absolute
1889 replacement. Return true if the replacement is done. Otherwise return
1891 bb is the basic block where the replacement is going to be done on. arg0
1892 is argument 0 from the phi. Likewise for arg1. */
1895 abs_replacement (basic_block cond_bb
, basic_block middle_bb
,
1896 edge e0 ATTRIBUTE_UNUSED
, edge e1
,
1897 gimple
*phi
, tree arg0
, tree arg1
)
1902 gimple_stmt_iterator gsi
;
1903 edge true_edge
, false_edge
;
1908 enum tree_code cond_code
;
1910 /* If the type says honor signed zeros we cannot do this
1912 if (HONOR_SIGNED_ZEROS (arg1
))
1915 /* OTHER_BLOCK must have only one executable statement which must have the
1916 form arg0 = -arg1 or arg1 = -arg0. */
1918 assign
= last_and_only_stmt (middle_bb
);
1919 /* If we did not find the proper negation assignment, then we cannot
1924 /* If we got here, then we have found the only executable statement
1925 in OTHER_BLOCK. If it is anything other than arg = -arg1 or
1926 arg1 = -arg0, then we cannot optimize. */
1927 if (gimple_code (assign
) != GIMPLE_ASSIGN
)
1930 lhs
= gimple_assign_lhs (assign
);
1932 if (gimple_assign_rhs_code (assign
) != NEGATE_EXPR
)
1935 rhs
= gimple_assign_rhs1 (assign
);
1937 /* The assignment has to be arg0 = -arg1 or arg1 = -arg0. */
1938 if (!(lhs
== arg0
&& rhs
== arg1
)
1939 && !(lhs
== arg1
&& rhs
== arg0
))
1942 cond
= last_stmt (cond_bb
);
1943 result
= PHI_RESULT (phi
);
1945 /* Only relationals comparing arg[01] against zero are interesting. */
1946 cond_code
= gimple_cond_code (cond
);
1947 if (cond_code
!= GT_EXPR
&& cond_code
!= GE_EXPR
1948 && cond_code
!= LT_EXPR
&& cond_code
!= LE_EXPR
)
1951 /* Make sure the conditional is arg[01] OP y. */
1952 if (gimple_cond_lhs (cond
) != rhs
)
1955 if (FLOAT_TYPE_P (TREE_TYPE (gimple_cond_rhs (cond
)))
1956 ? real_zerop (gimple_cond_rhs (cond
))
1957 : integer_zerop (gimple_cond_rhs (cond
)))
1962 /* We need to know which is the true edge and which is the false
1963 edge so that we know if have abs or negative abs. */
1964 extract_true_false_edges_from_block (cond_bb
, &true_edge
, &false_edge
);
1966 /* For GT_EXPR/GE_EXPR, if the true edge goes to OTHER_BLOCK, then we
1967 will need to negate the result. Similarly for LT_EXPR/LE_EXPR if
1968 the false edge goes to OTHER_BLOCK. */
1969 if (cond_code
== GT_EXPR
|| cond_code
== GE_EXPR
)
1974 if (e
->dest
== middle_bb
)
1979 /* If the code negates only iff positive then make sure to not
1980 introduce undefined behavior when negating or computing the absolute.
1981 ??? We could use range info if present to check for arg1 == INT_MIN. */
1983 && (ANY_INTEGRAL_TYPE_P (TREE_TYPE (arg1
))
1984 && ! TYPE_OVERFLOW_WRAPS (TREE_TYPE (arg1
))))
1987 result
= duplicate_ssa_name (result
, NULL
);
1990 lhs
= make_ssa_name (TREE_TYPE (result
));
1994 /* Build the modify expression with abs expression. */
1995 new_stmt
= gimple_build_assign (lhs
, ABS_EXPR
, rhs
);
1997 gsi
= gsi_last_bb (cond_bb
);
1998 gsi_insert_before (&gsi
, new_stmt
, GSI_NEW_STMT
);
2002 /* Get the right GSI. We want to insert after the recently
2003 added ABS_EXPR statement (which we know is the first statement
2005 new_stmt
= gimple_build_assign (result
, NEGATE_EXPR
, lhs
);
2007 gsi_insert_after (&gsi
, new_stmt
, GSI_NEW_STMT
);
2010 replace_phi_edge_with_variable (cond_bb
, e1
, phi
, result
);
2012 /* Note that we optimized this PHI. */
2016 /* Auxiliary functions to determine the set of memory accesses which
2017 can't trap because they are preceded by accesses to the same memory
2018 portion. We do that for MEM_REFs, so we only need to track
2019 the SSA_NAME of the pointer indirectly referenced. The algorithm
2020 simply is a walk over all instructions in dominator order. When
2021 we see an MEM_REF we determine if we've already seen a same
2022 ref anywhere up to the root of the dominator tree. If we do the
2023 current access can't trap. If we don't see any dominating access
2024 the current access might trap, but might also make later accesses
2025 non-trapping, so we remember it. We need to be careful with loads
2026 or stores, for instance a load might not trap, while a store would,
2027 so if we see a dominating read access this doesn't mean that a later
2028 write access would not trap. Hence we also need to differentiate the
2029 type of access(es) seen.
2031 ??? We currently are very conservative and assume that a load might
2032 trap even if a store doesn't (write-only memory). This probably is
2033 overly conservative.
2035 We currently support a special case that for !TREE_ADDRESSABLE automatic
2036 variables, it could ignore whether something is a load or store because the
2037 local stack should be always writable. */
2039 /* A hash-table of references (MEM_REF/ARRAY_REF/COMPONENT_REF), and in which
2040 basic block an *_REF through it was seen, which would constitute a
2041 no-trap region for same accesses.
2043 Size is needed to support 2 MEM_REFs of different types, like
2044 MEM<double>(s_1) and MEM<long>(s_1), which would compare equal with
2054 /* Hashtable helpers. */
2056 struct refs_hasher
: free_ptr_hash
<ref_to_bb
>
2058 static inline hashval_t
hash (const ref_to_bb
*);
2059 static inline bool equal (const ref_to_bb
*, const ref_to_bb
*);
2062 /* Used for quick clearing of the hash-table when we see calls.
2063 Hash entries with phase < nt_call_phase are invalid. */
2064 static unsigned int nt_call_phase
;
2066 /* The hash function. */
2069 refs_hasher::hash (const ref_to_bb
*n
)
2071 inchash::hash hstate
;
2072 inchash::add_expr (n
->exp
, hstate
, OEP_ADDRESS_OF
);
2073 hstate
.add_hwi (n
->size
);
2074 return hstate
.end ();
2077 /* The equality function of *P1 and *P2. */
2080 refs_hasher::equal (const ref_to_bb
*n1
, const ref_to_bb
*n2
)
2082 return operand_equal_p (n1
->exp
, n2
->exp
, OEP_ADDRESS_OF
)
2083 && n1
->size
== n2
->size
;
2086 class nontrapping_dom_walker
: public dom_walker
2089 nontrapping_dom_walker (cdi_direction direction
, hash_set
<tree
> *ps
)
2090 : dom_walker (direction
), m_nontrapping (ps
), m_seen_refs (128)
2093 virtual edge
before_dom_children (basic_block
);
2094 virtual void after_dom_children (basic_block
);
2098 /* We see the expression EXP in basic block BB. If it's an interesting
2099 expression (an MEM_REF through an SSA_NAME) possibly insert the
2100 expression into the set NONTRAP or the hash table of seen expressions.
2101 STORE is true if this expression is on the LHS, otherwise it's on
2103 void add_or_mark_expr (basic_block
, tree
, bool);
2105 hash_set
<tree
> *m_nontrapping
;
2107 /* The hash table for remembering what we've seen. */
2108 hash_table
<refs_hasher
> m_seen_refs
;
2111 /* Called by walk_dominator_tree, when entering the block BB. */
2113 nontrapping_dom_walker::before_dom_children (basic_block bb
)
2117 gimple_stmt_iterator gsi
;
2119 /* If we haven't seen all our predecessors, clear the hash-table. */
2120 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
2121 if ((((size_t)e
->src
->aux
) & 2) == 0)
2127 /* Mark this BB as being on the path to dominator root and as visited. */
2128 bb
->aux
= (void*)(1 | 2);
2130 /* And walk the statements in order. */
2131 for (gsi
= gsi_start_bb (bb
); !gsi_end_p (gsi
); gsi_next (&gsi
))
2133 gimple
*stmt
= gsi_stmt (gsi
);
2135 if ((gimple_code (stmt
) == GIMPLE_ASM
&& gimple_vdef (stmt
))
2136 || (is_gimple_call (stmt
)
2137 && (!nonfreeing_call_p (stmt
) || !nonbarrier_call_p (stmt
))))
2139 else if (gimple_assign_single_p (stmt
) && !gimple_has_volatile_ops (stmt
))
2141 add_or_mark_expr (bb
, gimple_assign_lhs (stmt
), true);
2142 add_or_mark_expr (bb
, gimple_assign_rhs1 (stmt
), false);
2148 /* Called by walk_dominator_tree, when basic block BB is exited. */
2150 nontrapping_dom_walker::after_dom_children (basic_block bb
)
2152 /* This BB isn't on the path to dominator root anymore. */
2156 /* We see the expression EXP in basic block BB. If it's an interesting
2161 possibly insert the expression into the set NONTRAP or the hash table
2162 of seen expressions. STORE is true if this expression is on the LHS,
2163 otherwise it's on the RHS. */
2165 nontrapping_dom_walker::add_or_mark_expr (basic_block bb
, tree exp
, bool store
)
2169 if ((TREE_CODE (exp
) == MEM_REF
|| TREE_CODE (exp
) == ARRAY_REF
2170 || TREE_CODE (exp
) == COMPONENT_REF
)
2171 && (size
= int_size_in_bytes (TREE_TYPE (exp
))) > 0)
2173 struct ref_to_bb map
;
2175 struct ref_to_bb
*r2bb
;
2176 basic_block found_bb
= 0;
2180 tree base
= get_base_address (exp
);
2181 /* Only record a LOAD of a local variable without address-taken, as
2182 the local stack is always writable. This allows cselim on a STORE
2183 with a dominating LOAD. */
2184 if (!auto_var_p (base
) || TREE_ADDRESSABLE (base
))
2188 /* Try to find the last seen *_REF, which can trap. */
2191 slot
= m_seen_refs
.find_slot (&map
, INSERT
);
2193 if (r2bb
&& r2bb
->phase
>= nt_call_phase
)
2194 found_bb
= r2bb
->bb
;
2196 /* If we've found a trapping *_REF, _and_ it dominates EXP
2197 (it's in a basic block on the path from us to the dominator root)
2198 then we can't trap. */
2199 if (found_bb
&& (((size_t)found_bb
->aux
) & 1) == 1)
2201 m_nontrapping
->add (exp
);
2205 /* EXP might trap, so insert it into the hash table. */
2208 r2bb
->phase
= nt_call_phase
;
2213 r2bb
= XNEW (struct ref_to_bb
);
2214 r2bb
->phase
= nt_call_phase
;
2224 /* This is the entry point of gathering non trapping memory accesses.
2225 It will do a dominator walk over the whole function, and it will
2226 make use of the bb->aux pointers. It returns a set of trees
2227 (the MEM_REFs itself) which can't trap. */
2228 static hash_set
<tree
> *
2229 get_non_trapping (void)
2232 hash_set
<tree
> *nontrap
= new hash_set
<tree
>;
2233 /* We're going to do a dominator walk, so ensure that we have
2234 dominance information. */
2235 calculate_dominance_info (CDI_DOMINATORS
);
2237 nontrapping_dom_walker (CDI_DOMINATORS
, nontrap
)
2238 .walk (cfun
->cfg
->x_entry_block_ptr
);
2240 clear_aux_for_blocks ();
2244 /* Do the main work of conditional store replacement. We already know
2245 that the recognized pattern looks like so:
2248 if (cond) goto MIDDLE_BB; else goto JOIN_BB (edge E1)
2251 fallthrough (edge E0)
2255 We check that MIDDLE_BB contains only one store, that that store
2256 doesn't trap (not via NOTRAP, but via checking if an access to the same
2257 memory location dominates us, or the store is to a local addressable
2258 object) and that the store has a "simple" RHS. */
2261 cond_store_replacement (basic_block middle_bb
, basic_block join_bb
,
2262 edge e0
, edge e1
, hash_set
<tree
> *nontrap
)
2264 gimple
*assign
= last_and_only_stmt (middle_bb
);
2265 tree lhs
, rhs
, name
, name2
;
2268 gimple_stmt_iterator gsi
;
2271 /* Check if middle_bb contains of only one store. */
2273 || !gimple_assign_single_p (assign
)
2274 || gimple_has_volatile_ops (assign
))
2277 /* And no PHI nodes so all uses in the single stmt are also
2278 available where we insert to. */
2279 if (!gimple_seq_empty_p (phi_nodes (middle_bb
)))
2282 locus
= gimple_location (assign
);
2283 lhs
= gimple_assign_lhs (assign
);
2284 rhs
= gimple_assign_rhs1 (assign
);
2285 if ((TREE_CODE (lhs
) != MEM_REF
2286 && TREE_CODE (lhs
) != ARRAY_REF
2287 && TREE_CODE (lhs
) != COMPONENT_REF
)
2288 || !is_gimple_reg_type (TREE_TYPE (lhs
)))
2291 /* Prove that we can move the store down. We could also check
2292 TREE_THIS_NOTRAP here, but in that case we also could move stores,
2293 whose value is not available readily, which we want to avoid. */
2294 if (!nontrap
->contains (lhs
))
2296 /* If LHS is an access to a local variable without address-taken
2297 (or when we allow data races) and known not to trap, we could
2298 always safely move down the store. */
2299 tree base
= get_base_address (lhs
);
2300 if (!auto_var_p (base
)
2301 || (TREE_ADDRESSABLE (base
) && !flag_store_data_races
)
2302 || tree_could_trap_p (lhs
))
2306 /* Now we've checked the constraints, so do the transformation:
2307 1) Remove the single store. */
2308 gsi
= gsi_for_stmt (assign
);
2309 unlink_stmt_vdef (assign
);
2310 gsi_remove (&gsi
, true);
2311 release_defs (assign
);
2313 /* Make both store and load use alias-set zero as we have to
2314 deal with the case of the store being a conditional change
2315 of the dynamic type. */
2316 lhs
= unshare_expr (lhs
);
2318 while (handled_component_p (*basep
))
2319 basep
= &TREE_OPERAND (*basep
, 0);
2320 if (TREE_CODE (*basep
) == MEM_REF
2321 || TREE_CODE (*basep
) == TARGET_MEM_REF
)
2322 TREE_OPERAND (*basep
, 1)
2323 = fold_convert (ptr_type_node
, TREE_OPERAND (*basep
, 1));
2325 *basep
= build2 (MEM_REF
, TREE_TYPE (*basep
),
2326 build_fold_addr_expr (*basep
),
2327 build_zero_cst (ptr_type_node
));
2329 /* 2) Insert a load from the memory of the store to the temporary
2330 on the edge which did not contain the store. */
2331 name
= make_temp_ssa_name (TREE_TYPE (lhs
), NULL
, "cstore");
2332 new_stmt
= gimple_build_assign (name
, lhs
);
2333 gimple_set_location (new_stmt
, locus
);
2334 lhs
= unshare_expr (lhs
);
2335 /* Set TREE_NO_WARNING on the rhs of the load to avoid uninit
2337 TREE_NO_WARNING (gimple_assign_rhs1 (new_stmt
)) = 1;
2338 gsi_insert_on_edge (e1
, new_stmt
);
2340 /* 3) Create a PHI node at the join block, with one argument
2341 holding the old RHS, and the other holding the temporary
2342 where we stored the old memory contents. */
2343 name2
= make_temp_ssa_name (TREE_TYPE (lhs
), NULL
, "cstore");
2344 newphi
= create_phi_node (name2
, join_bb
);
2345 add_phi_arg (newphi
, rhs
, e0
, locus
);
2346 add_phi_arg (newphi
, name
, e1
, locus
);
2348 new_stmt
= gimple_build_assign (lhs
, PHI_RESULT (newphi
));
2350 /* 4) Insert that PHI node. */
2351 gsi
= gsi_after_labels (join_bb
);
2352 if (gsi_end_p (gsi
))
2354 gsi
= gsi_last_bb (join_bb
);
2355 gsi_insert_after (&gsi
, new_stmt
, GSI_NEW_STMT
);
2358 gsi_insert_before (&gsi
, new_stmt
, GSI_NEW_STMT
);
2360 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2362 fprintf (dump_file
, "\nConditional store replacement happened!");
2363 fprintf (dump_file
, "\nReplaced the store with a load.");
2364 fprintf (dump_file
, "\nInserted a new PHI statement in joint block:\n");
2365 print_gimple_stmt (dump_file
, new_stmt
, 0, TDF_VOPS
|TDF_MEMSYMS
);
2371 /* Do the main work of conditional store replacement. */
2374 cond_if_else_store_replacement_1 (basic_block then_bb
, basic_block else_bb
,
2375 basic_block join_bb
, gimple
*then_assign
,
2376 gimple
*else_assign
)
2378 tree lhs_base
, lhs
, then_rhs
, else_rhs
, name
;
2379 location_t then_locus
, else_locus
;
2380 gimple_stmt_iterator gsi
;
2384 if (then_assign
== NULL
2385 || !gimple_assign_single_p (then_assign
)
2386 || gimple_clobber_p (then_assign
)
2387 || gimple_has_volatile_ops (then_assign
)
2388 || else_assign
== NULL
2389 || !gimple_assign_single_p (else_assign
)
2390 || gimple_clobber_p (else_assign
)
2391 || gimple_has_volatile_ops (else_assign
))
2394 lhs
= gimple_assign_lhs (then_assign
);
2395 if (!is_gimple_reg_type (TREE_TYPE (lhs
))
2396 || !operand_equal_p (lhs
, gimple_assign_lhs (else_assign
), 0))
2399 lhs_base
= get_base_address (lhs
);
2400 if (lhs_base
== NULL_TREE
2401 || (!DECL_P (lhs_base
) && TREE_CODE (lhs_base
) != MEM_REF
))
2404 then_rhs
= gimple_assign_rhs1 (then_assign
);
2405 else_rhs
= gimple_assign_rhs1 (else_assign
);
2406 then_locus
= gimple_location (then_assign
);
2407 else_locus
= gimple_location (else_assign
);
2409 /* Now we've checked the constraints, so do the transformation:
2410 1) Remove the stores. */
2411 gsi
= gsi_for_stmt (then_assign
);
2412 unlink_stmt_vdef (then_assign
);
2413 gsi_remove (&gsi
, true);
2414 release_defs (then_assign
);
2416 gsi
= gsi_for_stmt (else_assign
);
2417 unlink_stmt_vdef (else_assign
);
2418 gsi_remove (&gsi
, true);
2419 release_defs (else_assign
);
2421 /* 2) Create a PHI node at the join block, with one argument
2422 holding the old RHS, and the other holding the temporary
2423 where we stored the old memory contents. */
2424 name
= make_temp_ssa_name (TREE_TYPE (lhs
), NULL
, "cstore");
2425 newphi
= create_phi_node (name
, join_bb
);
2426 add_phi_arg (newphi
, then_rhs
, EDGE_SUCC (then_bb
, 0), then_locus
);
2427 add_phi_arg (newphi
, else_rhs
, EDGE_SUCC (else_bb
, 0), else_locus
);
2429 new_stmt
= gimple_build_assign (lhs
, PHI_RESULT (newphi
));
2431 /* 3) Insert that PHI node. */
2432 gsi
= gsi_after_labels (join_bb
);
2433 if (gsi_end_p (gsi
))
2435 gsi
= gsi_last_bb (join_bb
);
2436 gsi_insert_after (&gsi
, new_stmt
, GSI_NEW_STMT
);
2439 gsi_insert_before (&gsi
, new_stmt
, GSI_NEW_STMT
);
2444 /* Return the single store in BB with VDEF or NULL if there are
2445 other stores in the BB or loads following the store. */
2448 single_trailing_store_in_bb (basic_block bb
, tree vdef
)
2450 if (SSA_NAME_IS_DEFAULT_DEF (vdef
))
2452 gimple
*store
= SSA_NAME_DEF_STMT (vdef
);
2453 if (gimple_bb (store
) != bb
2454 || gimple_code (store
) == GIMPLE_PHI
)
2457 /* Verify there is no other store in this BB. */
2458 if (!SSA_NAME_IS_DEFAULT_DEF (gimple_vuse (store
))
2459 && gimple_bb (SSA_NAME_DEF_STMT (gimple_vuse (store
))) == bb
2460 && gimple_code (SSA_NAME_DEF_STMT (gimple_vuse (store
))) != GIMPLE_PHI
)
2463 /* Verify there is no load or store after the store. */
2464 use_operand_p use_p
;
2465 imm_use_iterator imm_iter
;
2466 FOR_EACH_IMM_USE_FAST (use_p
, imm_iter
, gimple_vdef (store
))
2467 if (USE_STMT (use_p
) != store
2468 && gimple_bb (USE_STMT (use_p
)) == bb
)
2474 /* Conditional store replacement. We already know
2475 that the recognized pattern looks like so:
2478 if (cond) goto THEN_BB; else goto ELSE_BB (edge E1)
2488 fallthrough (edge E0)
2492 We check that it is safe to sink the store to JOIN_BB by verifying that
2493 there are no read-after-write or write-after-write dependencies in
2494 THEN_BB and ELSE_BB. */
2497 cond_if_else_store_replacement (basic_block then_bb
, basic_block else_bb
,
2498 basic_block join_bb
)
2500 vec
<data_reference_p
> then_datarefs
, else_datarefs
;
2501 vec
<ddr_p
> then_ddrs
, else_ddrs
;
2502 gimple
*then_store
, *else_store
;
2503 bool found
, ok
= false, res
;
2504 struct data_dependence_relation
*ddr
;
2505 data_reference_p then_dr
, else_dr
;
2507 tree then_lhs
, else_lhs
;
2508 basic_block blocks
[3];
2510 /* Handle the case with single store in THEN_BB and ELSE_BB. That is
2511 cheap enough to always handle as it allows us to elide dependence
2514 for (gphi_iterator si
= gsi_start_phis (join_bb
); !gsi_end_p (si
);
2516 if (virtual_operand_p (gimple_phi_result (si
.phi ())))
2523 tree then_vdef
= PHI_ARG_DEF_FROM_EDGE (vphi
, single_succ_edge (then_bb
));
2524 tree else_vdef
= PHI_ARG_DEF_FROM_EDGE (vphi
, single_succ_edge (else_bb
));
2525 gimple
*then_assign
= single_trailing_store_in_bb (then_bb
, then_vdef
);
2528 gimple
*else_assign
= single_trailing_store_in_bb (else_bb
, else_vdef
);
2530 return cond_if_else_store_replacement_1 (then_bb
, else_bb
, join_bb
,
2531 then_assign
, else_assign
);
2534 /* If either vectorization or if-conversion is disabled then do
2535 not sink any stores. */
2536 if (param_max_stores_to_sink
== 0
2537 || (!flag_tree_loop_vectorize
&& !flag_tree_slp_vectorize
)
2538 || !flag_tree_loop_if_convert
)
2541 /* Find data references. */
2542 then_datarefs
.create (1);
2543 else_datarefs
.create (1);
2544 if ((find_data_references_in_bb (NULL
, then_bb
, &then_datarefs
)
2546 || !then_datarefs
.length ()
2547 || (find_data_references_in_bb (NULL
, else_bb
, &else_datarefs
)
2549 || !else_datarefs
.length ())
2551 free_data_refs (then_datarefs
);
2552 free_data_refs (else_datarefs
);
2556 /* Find pairs of stores with equal LHS. */
2557 auto_vec
<gimple
*, 1> then_stores
, else_stores
;
2558 FOR_EACH_VEC_ELT (then_datarefs
, i
, then_dr
)
2560 if (DR_IS_READ (then_dr
))
2563 then_store
= DR_STMT (then_dr
);
2564 then_lhs
= gimple_get_lhs (then_store
);
2565 if (then_lhs
== NULL_TREE
)
2569 FOR_EACH_VEC_ELT (else_datarefs
, j
, else_dr
)
2571 if (DR_IS_READ (else_dr
))
2574 else_store
= DR_STMT (else_dr
);
2575 else_lhs
= gimple_get_lhs (else_store
);
2576 if (else_lhs
== NULL_TREE
)
2579 if (operand_equal_p (then_lhs
, else_lhs
, 0))
2589 then_stores
.safe_push (then_store
);
2590 else_stores
.safe_push (else_store
);
2593 /* No pairs of stores found. */
2594 if (!then_stores
.length ()
2595 || then_stores
.length () > (unsigned) param_max_stores_to_sink
)
2597 free_data_refs (then_datarefs
);
2598 free_data_refs (else_datarefs
);
2602 /* Compute and check data dependencies in both basic blocks. */
2603 then_ddrs
.create (1);
2604 else_ddrs
.create (1);
2605 if (!compute_all_dependences (then_datarefs
, &then_ddrs
,
2607 || !compute_all_dependences (else_datarefs
, &else_ddrs
,
2610 free_dependence_relations (then_ddrs
);
2611 free_dependence_relations (else_ddrs
);
2612 free_data_refs (then_datarefs
);
2613 free_data_refs (else_datarefs
);
2616 blocks
[0] = then_bb
;
2617 blocks
[1] = else_bb
;
2618 blocks
[2] = join_bb
;
2619 renumber_gimple_stmt_uids_in_blocks (blocks
, 3);
2621 /* Check that there are no read-after-write or write-after-write dependencies
2623 FOR_EACH_VEC_ELT (then_ddrs
, i
, ddr
)
2625 struct data_reference
*dra
= DDR_A (ddr
);
2626 struct data_reference
*drb
= DDR_B (ddr
);
2628 if (DDR_ARE_DEPENDENT (ddr
) != chrec_known
2629 && ((DR_IS_READ (dra
) && DR_IS_WRITE (drb
)
2630 && gimple_uid (DR_STMT (dra
)) > gimple_uid (DR_STMT (drb
)))
2631 || (DR_IS_READ (drb
) && DR_IS_WRITE (dra
)
2632 && gimple_uid (DR_STMT (drb
)) > gimple_uid (DR_STMT (dra
)))
2633 || (DR_IS_WRITE (dra
) && DR_IS_WRITE (drb
))))
2635 free_dependence_relations (then_ddrs
);
2636 free_dependence_relations (else_ddrs
);
2637 free_data_refs (then_datarefs
);
2638 free_data_refs (else_datarefs
);
2643 /* Check that there are no read-after-write or write-after-write dependencies
2645 FOR_EACH_VEC_ELT (else_ddrs
, i
, ddr
)
2647 struct data_reference
*dra
= DDR_A (ddr
);
2648 struct data_reference
*drb
= DDR_B (ddr
);
2650 if (DDR_ARE_DEPENDENT (ddr
) != chrec_known
2651 && ((DR_IS_READ (dra
) && DR_IS_WRITE (drb
)
2652 && gimple_uid (DR_STMT (dra
)) > gimple_uid (DR_STMT (drb
)))
2653 || (DR_IS_READ (drb
) && DR_IS_WRITE (dra
)
2654 && gimple_uid (DR_STMT (drb
)) > gimple_uid (DR_STMT (dra
)))
2655 || (DR_IS_WRITE (dra
) && DR_IS_WRITE (drb
))))
2657 free_dependence_relations (then_ddrs
);
2658 free_dependence_relations (else_ddrs
);
2659 free_data_refs (then_datarefs
);
2660 free_data_refs (else_datarefs
);
2665 /* Sink stores with same LHS. */
2666 FOR_EACH_VEC_ELT (then_stores
, i
, then_store
)
2668 else_store
= else_stores
[i
];
2669 res
= cond_if_else_store_replacement_1 (then_bb
, else_bb
, join_bb
,
2670 then_store
, else_store
);
2674 free_dependence_relations (then_ddrs
);
2675 free_dependence_relations (else_ddrs
);
2676 free_data_refs (then_datarefs
);
2677 free_data_refs (else_datarefs
);
2682 /* Return TRUE if STMT has a VUSE whose corresponding VDEF is in BB. */
2685 local_mem_dependence (gimple
*stmt
, basic_block bb
)
2687 tree vuse
= gimple_vuse (stmt
);
2693 def
= SSA_NAME_DEF_STMT (vuse
);
2694 return (def
&& gimple_bb (def
) == bb
);
2697 /* Given a "diamond" control-flow pattern where BB0 tests a condition,
2698 BB1 and BB2 are "then" and "else" blocks dependent on this test,
2699 and BB3 rejoins control flow following BB1 and BB2, look for
2700 opportunities to hoist loads as follows. If BB3 contains a PHI of
2701 two loads, one each occurring in BB1 and BB2, and the loads are
2702 provably of adjacent fields in the same structure, then move both
2703 loads into BB0. Of course this can only be done if there are no
2704 dependencies preventing such motion.
2706 One of the hoisted loads will always be speculative, so the
2707 transformation is currently conservative:
2709 - The fields must be strictly adjacent.
2710 - The two fields must occupy a single memory block that is
2711 guaranteed to not cross a page boundary.
2713 The last is difficult to prove, as such memory blocks should be
2714 aligned on the minimum of the stack alignment boundary and the
2715 alignment guaranteed by heap allocation interfaces. Thus we rely
2716 on a parameter for the alignment value.
2718 Provided a good value is used for the last case, the first
2719 restriction could possibly be relaxed. */
2722 hoist_adjacent_loads (basic_block bb0
, basic_block bb1
,
2723 basic_block bb2
, basic_block bb3
)
2725 int param_align
= param_l1_cache_line_size
;
2726 unsigned param_align_bits
= (unsigned) (param_align
* BITS_PER_UNIT
);
2729 /* Walk the phis in bb3 looking for an opportunity. We are looking
2730 for phis of two SSA names, one each of which is defined in bb1 and
2732 for (gsi
= gsi_start_phis (bb3
); !gsi_end_p (gsi
); gsi_next (&gsi
))
2734 gphi
*phi_stmt
= gsi
.phi ();
2735 gimple
*def1
, *def2
;
2736 tree arg1
, arg2
, ref1
, ref2
, field1
, field2
;
2737 tree tree_offset1
, tree_offset2
, tree_size2
, next
;
2738 int offset1
, offset2
, size2
;
2740 gimple_stmt_iterator gsi2
;
2741 basic_block bb_for_def1
, bb_for_def2
;
2743 if (gimple_phi_num_args (phi_stmt
) != 2
2744 || virtual_operand_p (gimple_phi_result (phi_stmt
)))
2747 arg1
= gimple_phi_arg_def (phi_stmt
, 0);
2748 arg2
= gimple_phi_arg_def (phi_stmt
, 1);
2750 if (TREE_CODE (arg1
) != SSA_NAME
2751 || TREE_CODE (arg2
) != SSA_NAME
2752 || SSA_NAME_IS_DEFAULT_DEF (arg1
)
2753 || SSA_NAME_IS_DEFAULT_DEF (arg2
))
2756 def1
= SSA_NAME_DEF_STMT (arg1
);
2757 def2
= SSA_NAME_DEF_STMT (arg2
);
2759 if ((gimple_bb (def1
) != bb1
|| gimple_bb (def2
) != bb2
)
2760 && (gimple_bb (def2
) != bb1
|| gimple_bb (def1
) != bb2
))
2763 /* Check the mode of the arguments to be sure a conditional move
2764 can be generated for it. */
2765 if (optab_handler (movcc_optab
, TYPE_MODE (TREE_TYPE (arg1
)))
2766 == CODE_FOR_nothing
)
2769 /* Both statements must be assignments whose RHS is a COMPONENT_REF. */
2770 if (!gimple_assign_single_p (def1
)
2771 || !gimple_assign_single_p (def2
)
2772 || gimple_has_volatile_ops (def1
)
2773 || gimple_has_volatile_ops (def2
))
2776 ref1
= gimple_assign_rhs1 (def1
);
2777 ref2
= gimple_assign_rhs1 (def2
);
2779 if (TREE_CODE (ref1
) != COMPONENT_REF
2780 || TREE_CODE (ref2
) != COMPONENT_REF
)
2783 /* The zeroth operand of the two component references must be
2784 identical. It is not sufficient to compare get_base_address of
2785 the two references, because this could allow for different
2786 elements of the same array in the two trees. It is not safe to
2787 assume that the existence of one array element implies the
2788 existence of a different one. */
2789 if (!operand_equal_p (TREE_OPERAND (ref1
, 0), TREE_OPERAND (ref2
, 0), 0))
2792 field1
= TREE_OPERAND (ref1
, 1);
2793 field2
= TREE_OPERAND (ref2
, 1);
2795 /* Check for field adjacency, and ensure field1 comes first. */
2796 for (next
= DECL_CHAIN (field1
);
2797 next
&& TREE_CODE (next
) != FIELD_DECL
;
2798 next
= DECL_CHAIN (next
))
2803 for (next
= DECL_CHAIN (field2
);
2804 next
&& TREE_CODE (next
) != FIELD_DECL
;
2805 next
= DECL_CHAIN (next
))
2811 std::swap (field1
, field2
);
2812 std::swap (def1
, def2
);
2815 bb_for_def1
= gimple_bb (def1
);
2816 bb_for_def2
= gimple_bb (def2
);
2818 /* Check for proper alignment of the first field. */
2819 tree_offset1
= bit_position (field1
);
2820 tree_offset2
= bit_position (field2
);
2821 tree_size2
= DECL_SIZE (field2
);
2823 if (!tree_fits_uhwi_p (tree_offset1
)
2824 || !tree_fits_uhwi_p (tree_offset2
)
2825 || !tree_fits_uhwi_p (tree_size2
))
2828 offset1
= tree_to_uhwi (tree_offset1
);
2829 offset2
= tree_to_uhwi (tree_offset2
);
2830 size2
= tree_to_uhwi (tree_size2
);
2831 align1
= DECL_ALIGN (field1
) % param_align_bits
;
2833 if (offset1
% BITS_PER_UNIT
!= 0)
2836 /* For profitability, the two field references should fit within
2837 a single cache line. */
2838 if (align1
+ offset2
- offset1
+ size2
> param_align_bits
)
2841 /* The two expressions cannot be dependent upon vdefs defined
2843 if (local_mem_dependence (def1
, bb_for_def1
)
2844 || local_mem_dependence (def2
, bb_for_def2
))
2847 /* The conditions are satisfied; hoist the loads from bb1 and bb2 into
2848 bb0. We hoist the first one first so that a cache miss is handled
2849 efficiently regardless of hardware cache-fill policy. */
2850 gsi2
= gsi_for_stmt (def1
);
2851 gsi_move_to_bb_end (&gsi2
, bb0
);
2852 gsi2
= gsi_for_stmt (def2
);
2853 gsi_move_to_bb_end (&gsi2
, bb0
);
2855 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2858 "\nHoisting adjacent loads from %d and %d into %d: \n",
2859 bb_for_def1
->index
, bb_for_def2
->index
, bb0
->index
);
2860 print_gimple_stmt (dump_file
, def1
, 0, TDF_VOPS
|TDF_MEMSYMS
);
2861 print_gimple_stmt (dump_file
, def2
, 0, TDF_VOPS
|TDF_MEMSYMS
);
2866 /* Determine whether we should attempt to hoist adjacent loads out of
2867 diamond patterns in pass_phiopt. Always hoist loads if
2868 -fhoist-adjacent-loads is specified and the target machine has
2869 both a conditional move instruction and a defined cache line size. */
2872 gate_hoist_loads (void)
2874 return (flag_hoist_adjacent_loads
== 1
2875 && param_l1_cache_line_size
2876 && HAVE_conditional_move
);
2879 /* This pass tries to replaces an if-then-else block with an
2880 assignment. We have four kinds of transformations. Some of these
2881 transformations are also performed by the ifcvt RTL optimizer.
2883 Conditional Replacement
2884 -----------------------
2886 This transformation, implemented in conditional_replacement,
2890 if (cond) goto bb2; else goto bb1;
2893 x = PHI <0 (bb1), 1 (bb0), ...>;
2901 x = PHI <x' (bb0), ...>;
2903 We remove bb1 as it becomes unreachable. This occurs often due to
2904 gimplification of conditionals.
2909 This transformation, implemented in value_replacement, replaces
2912 if (a != b) goto bb2; else goto bb1;
2915 x = PHI <a (bb1), b (bb0), ...>;
2921 x = PHI <b (bb0), ...>;
2923 This opportunity can sometimes occur as a result of other
2927 Another case caught by value replacement looks like this:
2933 if (t3 != 0) goto bb1; else goto bb2;
2949 This transformation, implemented in abs_replacement, replaces
2952 if (a >= 0) goto bb2; else goto bb1;
2956 x = PHI <x (bb1), a (bb0), ...>;
2963 x = PHI <x' (bb0), ...>;
2968 This transformation, minmax_replacement replaces
2971 if (a <= b) goto bb2; else goto bb1;
2974 x = PHI <b (bb1), a (bb0), ...>;
2979 x' = MIN_EXPR (a, b)
2981 x = PHI <x' (bb0), ...>;
2983 A similar transformation is done for MAX_EXPR.
2986 This pass also performs a fifth transformation of a slightly different
2989 Factor conversion in COND_EXPR
2990 ------------------------------
2992 This transformation factors the conversion out of COND_EXPR with
2993 factor_out_conditional_conversion.
2996 if (a <= CST) goto <bb 3>; else goto <bb 4>;
3000 tmp = PHI <tmp, CST>
3003 if (a <= CST) goto <bb 3>; else goto <bb 4>;
3009 Adjacent Load Hoisting
3010 ----------------------
3012 This transformation replaces
3015 if (...) goto bb2; else goto bb1;
3017 x1 = (<expr>).field1;
3020 x2 = (<expr>).field2;
3027 x1 = (<expr>).field1;
3028 x2 = (<expr>).field2;
3029 if (...) goto bb2; else goto bb1;
3036 The purpose of this transformation is to enable generation of conditional
3037 move instructions such as Intel CMOVE or PowerPC ISEL. Because one of
3038 the loads is speculative, the transformation is restricted to very
3039 specific cases to avoid introducing a page fault. We are looking for
3047 where left and right are typically adjacent pointers in a tree structure. */
3051 const pass_data pass_data_phiopt
=
3053 GIMPLE_PASS
, /* type */
3054 "phiopt", /* name */
3055 OPTGROUP_NONE
, /* optinfo_flags */
3056 TV_TREE_PHIOPT
, /* tv_id */
3057 ( PROP_cfg
| PROP_ssa
), /* properties_required */
3058 0, /* properties_provided */
3059 0, /* properties_destroyed */
3060 0, /* todo_flags_start */
3061 0, /* todo_flags_finish */
3064 class pass_phiopt
: public gimple_opt_pass
3067 pass_phiopt (gcc::context
*ctxt
)
3068 : gimple_opt_pass (pass_data_phiopt
, ctxt
), early_p (false)
3071 /* opt_pass methods: */
3072 opt_pass
* clone () { return new pass_phiopt (m_ctxt
); }
3073 void set_pass_param (unsigned n
, bool param
)
3075 gcc_assert (n
== 0);
3078 virtual bool gate (function
*) { return flag_ssa_phiopt
; }
3079 virtual unsigned int execute (function
*)
3081 return tree_ssa_phiopt_worker (false,
3082 !early_p
? gate_hoist_loads () : false,
3088 }; // class pass_phiopt
3093 make_pass_phiopt (gcc::context
*ctxt
)
3095 return new pass_phiopt (ctxt
);
3100 const pass_data pass_data_cselim
=
3102 GIMPLE_PASS
, /* type */
3103 "cselim", /* name */
3104 OPTGROUP_NONE
, /* optinfo_flags */
3105 TV_TREE_PHIOPT
, /* tv_id */
3106 ( PROP_cfg
| PROP_ssa
), /* properties_required */
3107 0, /* properties_provided */
3108 0, /* properties_destroyed */
3109 0, /* todo_flags_start */
3110 0, /* todo_flags_finish */
3113 class pass_cselim
: public gimple_opt_pass
3116 pass_cselim (gcc::context
*ctxt
)
3117 : gimple_opt_pass (pass_data_cselim
, ctxt
)
3120 /* opt_pass methods: */
3121 virtual bool gate (function
*) { return flag_tree_cselim
; }
3122 virtual unsigned int execute (function
*) { return tree_ssa_cs_elim (); }
3124 }; // class pass_cselim
3129 make_pass_cselim (gcc::context
*ctxt
)
3131 return new pass_cselim (ctxt
);