1 /*
2 * Copyright (c) 1997, 2026, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
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16 * 2 along with this work; if not, write to the Free Software Foundation,
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23 */
24
25 #ifndef SHARE_OPTO_CFGNODE_HPP
26 #define SHARE_OPTO_CFGNODE_HPP
27
28 #include "opto/multnode.hpp"
29 #include "opto/node.hpp"
30 #include "opto/opcodes.hpp"
31 #include "opto/predicates_enums.hpp"
32 #include "opto/type.hpp"
33 #include "runtime/arguments.hpp"
34
35 // Portions of code courtesy of Clifford Click
36
37 // Optimization - Graph Style
38
39 class Matcher;
40 class Node;
41 class RegionNode;
42 class TypeNode;
43 class PhiNode;
44 class GotoNode;
45 class MultiNode;
46 class MultiBranchNode;
47 class IfNode;
48 class PCTableNode;
49 class JumpNode;
50 class CatchNode;
51 class NeverBranchNode;
52 class BlackholeNode;
53 class ProjNode;
54 class CProjNode;
55 class IfTrueNode;
56 class IfFalseNode;
57 class CatchProjNode;
58 class JProjNode;
59 class JumpProjNode;
60 class SCMemProjNode;
61 class PhaseIdealLoop;
62 enum class AssertionPredicateType;
63 enum class PredicateState;
64
65 //------------------------------RegionNode-------------------------------------
66 // The class of RegionNodes, which can be mapped to basic blocks in the
67 // program. Their inputs point to Control sources. PhiNodes (described
68 // below) have an input point to a RegionNode. Merged data inputs to PhiNodes
69 // correspond 1-to-1 with RegionNode inputs. The zero input of a PhiNode is
70 // the RegionNode, and the zero input of the RegionNode is itself.
71 class RegionNode : public Node {
72 public:
73 enum LoopStatus {
74 // No guarantee: the region may be an irreducible loop entry, thus we have to
75 // be careful when removing entry control to it.
76 MaybeIrreducibleEntry,
77 // Limited guarantee: this region may be (nested) inside an irreducible loop,
78 // but it will never be an irreducible loop entry.
79 NeverIrreducibleEntry,
80 // Strong guarantee: this region is not (nested) inside an irreducible loop.
81 Reducible,
82 };
83
84 private:
85 bool _is_unreachable_region;
86 LoopStatus _loop_status;
87
88 bool is_possible_unsafe_loop() const;
89 bool is_unreachable_from_root(const PhaseGVN* phase) const;
90 public:
91 // Node layout (parallels PhiNode):
92 enum { Region, // Generally points to self.
93 Control // Control arcs are [1..len)
94 };
95
96 RegionNode(uint required)
97 : Node(required),
98 _is_unreachable_region(false),
99 _loop_status(LoopStatus::NeverIrreducibleEntry)
100 {
101 init_class_id(Class_Region);
102 init_req(0, this);
103 }
104
105 Node* is_copy() const {
106 const Node* r = _in[Region];
107 if (r == nullptr)
108 return nonnull_req();
109 return nullptr; // not a copy!
110 }
111 PhiNode* has_phi() const; // returns an arbitrary phi user, or null
112 PhiNode* has_unique_phi() const; // returns the unique phi user, or null
113 // Is this region node unreachable from root?
114 bool is_unreachable_region(const PhaseGVN* phase);
115 #ifdef ASSERT
116 bool is_in_infinite_subgraph();
117 static bool are_all_nodes_in_infinite_subgraph(Unique_Node_List& worklist);
118 #endif //ASSERT
119 LoopStatus loop_status() const { return _loop_status; };
120 void set_loop_status(LoopStatus status);
121 bool can_be_irreducible_entry() const;
122
123 virtual int Opcode() const;
124 virtual uint size_of() const { return sizeof(*this); }
125 virtual bool pinned() const { return (const Node*)in(0) == this; }
126 virtual bool is_CFG() const { return true; }
127 virtual uint hash() const { return NO_HASH; } // CFG nodes do not hash
128 virtual const Type* bottom_type() const { return Type::CONTROL; }
129 virtual const Type* Value(PhaseGVN* phase) const;
130 virtual Node* Identity(PhaseGVN* phase);
131 virtual Node* Ideal(PhaseGVN* phase, bool can_reshape);
132 void remove_unreachable_subgraph(PhaseIterGVN* igvn);
133 virtual const RegMask &out_RegMask() const;
134 bool is_diamond() const;
135 void try_clean_mem_phis(PhaseIterGVN* phase);
136 bool optimize_trichotomy(PhaseIterGVN* igvn);
137 NOT_PRODUCT(virtual void dump_spec(outputStream* st) const;)
138 };
139
140 //------------------------------JProjNode--------------------------------------
141 // jump projection for node that produces multiple control-flow paths
142 class JProjNode : public ProjNode {
143 public:
144 JProjNode( Node* ctrl, uint idx ) : ProjNode(ctrl,idx) {}
145 virtual int Opcode() const;
146 virtual bool is_CFG() const { return true; }
147 virtual uint hash() const { return NO_HASH; } // CFG nodes do not hash
148 virtual const Node* is_block_proj() const { return in(0); }
149 virtual const RegMask& out_RegMask() const;
150 virtual uint ideal_reg() const { return 0; }
151 };
152
153 //------------------------------PhiNode----------------------------------------
154 // PhiNodes merge values from different Control paths. Slot 0 points to the
155 // controlling RegionNode. Other slots map 1-for-1 with incoming control flow
156 // paths to the RegionNode.
157 class PhiNode : public TypeNode {
158 friend class PhaseRenumberLive;
159
160 const TypePtr* const _adr_type; // non-null only for Type::MEMORY nodes.
161 // The following fields are only used for data PhiNodes to indicate
162 // that the PhiNode represents the value of a known instance field.
163 int _inst_mem_id; // Instance memory id (node index of the memory Phi)
164 int _inst_id; // Instance id of the memory slice.
165 const int _inst_index; // Alias index of the instance memory slice.
166 // Array elements references have the same alias_idx but different offset.
167 const int _inst_offset; // Offset of the instance memory slice.
168 // Size is bigger to hold the _adr_type field.
169 virtual uint hash() const; // Check the type
170 virtual bool cmp( const Node &n ) const;
171 virtual uint size_of() const { return sizeof(*this); }
172
173 // Determine if CMoveNode::is_cmove_id can be used at this join point.
174 Node* is_cmove_id(PhaseTransform* phase, int true_path);
175 bool wait_for_region_igvn(PhaseGVN* phase);
176 bool is_data_loop(RegionNode* r, Node* uin, const PhaseGVN* phase);
177
178 static Node* clone_through_phi(Node* root_phi, const Type* t, uint c, PhaseIterGVN* igvn);
179 static Node* merge_through_phi(Node* root_phi, PhaseIterGVN* igvn);
180
181 bool must_wait_for_region_in_irreducible_loop(PhaseGVN* phase) const;
182
183 bool can_push_inline_types_down(PhaseGVN* phase, bool can_reshape, ciInlineKlass*& inline_klass);
184 InlineTypeNode* push_inline_types_down(PhaseGVN* phase, bool can_reshape, ciInlineKlass* inline_klass);
185
186 bool is_split_through_mergemem_terminating() const;
187
188 void verify_type_stability(const PhaseGVN* phase, const Type* union_of_input_types, const Type* new_type) const NOT_DEBUG_RETURN;
189 bool wait_for_cast_input_igvn(const PhaseIterGVN* igvn) const;
190
191 public:
192 // Node layout (parallels RegionNode):
193 enum { Region, // Control input is the Phi's region.
194 Input // Input values are [1..len)
195 };
196
197 PhiNode( Node *r, const Type *t, const TypePtr* at = nullptr,
198 const int imid = -1,
199 const int iid = TypeOopPtr::InstanceTop,
200 const int iidx = Compile::AliasIdxTop,
201 const int ioffs = Type::OffsetTop )
202 : TypeNode(t,r->req()),
203 _adr_type(at),
204 _inst_mem_id(imid),
205 _inst_id(iid),
206 _inst_index(iidx),
207 _inst_offset(ioffs)
208 {
209 init_class_id(Class_Phi);
210 init_req(0, r);
211 verify_adr_type();
212 }
213 // create a new phi with in edges matching r and set (initially) to x
214 static PhiNode* make( Node* r, Node* x );
215 // extra type arguments override the new phi's bottom_type and adr_type
216 static PhiNode* make( Node* r, Node* x, const Type *t, const TypePtr* at = nullptr );
217 // create a new phi with narrowed memory type
218 PhiNode* slice_memory(const TypePtr* adr_type) const;
219 PhiNode* split_out_instance(const TypePtr* at, PhaseIterGVN *igvn) const;
220 // like make(r, x), but does not initialize the in edges to x
221 static PhiNode* make_blank( Node* r, Node* x );
222
223 // Accessors
224 RegionNode* region() const { Node* r = in(Region); assert(!r || r->is_Region(), ""); return (RegionNode*)r; }
225
226 bool is_tripcount(BasicType bt) const;
227
228 // Determine a unique non-trivial input, if any.
229 // Ignore casts if it helps. Return null on failure.
230 Node* unique_input(PhaseValues* phase, bool uncast);
231 Node* unique_input(PhaseValues* phase) {
232 Node* uin = unique_input(phase, false);
233 if (uin == nullptr) {
234 uin = unique_input(phase, true);
235 }
236 return uin;
237 }
238 Node* unique_constant_input_recursive(PhaseGVN* phase);
239
240 // Check for a simple dead loop.
241 enum LoopSafety { Safe = 0, Unsafe, UnsafeLoop };
242 LoopSafety simple_data_loop_check(Node *in) const;
243 // Is it unsafe data loop? It becomes a dead loop if this phi node removed.
244 bool is_unsafe_data_reference(Node *in) const;
245 int is_diamond_phi() const;
246 bool try_clean_memory_phi(PhaseIterGVN* igvn);
247 virtual int Opcode() const;
248 virtual bool pinned() const { return in(0) != nullptr; }
249 virtual const TypePtr *adr_type() const { verify_adr_type(true); return _adr_type; }
250
251 void set_inst_mem_id(int inst_mem_id) { _inst_mem_id = inst_mem_id; }
252 int inst_mem_id() const { return _inst_mem_id; }
253 int inst_id() const { return _inst_id; }
254 int inst_index() const { return _inst_index; }
255 int inst_offset() const { return _inst_offset; }
256 bool is_same_inst_field(const Type* tp, int mem_id, int id, int index, int offset) {
257 return type()->basic_type() == tp->basic_type() &&
258 inst_mem_id() == mem_id &&
259 inst_id() == id &&
260 inst_index() == index &&
261 inst_offset() == offset &&
262 type()->higher_equal(tp);
263 }
264
265 bool can_be_inline_type() const {
266 return Arguments::is_valhalla_enabled() && _type->isa_instptr() && _type->is_instptr()->can_be_inline_type();
267 }
268
269 Node* try_push_inline_types_down(PhaseGVN* phase, bool can_reshape);
270 DEBUG_ONLY(bool can_push_inline_types_down(PhaseGVN* phase);)
271
272 virtual const Type* Value(PhaseGVN* phase) const;
273 virtual Node* Identity(PhaseGVN* phase);
274 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
275 virtual const RegMask &out_RegMask() const;
276 virtual const RegMask &in_RegMask(uint) const;
277 #ifndef PRODUCT
278 virtual void dump_spec(outputStream *st) const;
279 #endif
280 #ifdef ASSERT
281 void verify_adr_type(VectorSet& visited, const TypePtr* at) const;
282 void verify_adr_type(bool recursive = false) const;
283 #else //ASSERT
284 void verify_adr_type(bool recursive = false) const {}
285 #endif //ASSERT
286
287 const TypeTuple* collect_types(PhaseGVN* phase) const;
288 bool can_be_replaced_by(const PhiNode* other) const;
289 };
290
291 //------------------------------GotoNode---------------------------------------
292 // GotoNodes perform direct branches.
293 class GotoNode : public Node {
294 public:
295 GotoNode( Node *control ) : Node(control) {}
296 virtual int Opcode() const;
297 virtual bool pinned() const { return true; }
298 virtual bool is_CFG() const { return true; }
299 virtual uint hash() const { return NO_HASH; } // CFG nodes do not hash
300 virtual const Node *is_block_proj() const { return this; }
301 virtual const Type *bottom_type() const { return Type::CONTROL; }
302 virtual const Type* Value(PhaseGVN* phase) const;
303 virtual Node* Identity(PhaseGVN* phase);
304 virtual const RegMask &out_RegMask() const;
305 };
306
307 //------------------------------CProjNode--------------------------------------
308 // control projection for node that produces multiple control-flow paths
309 class CProjNode : public ProjNode {
310 public:
311 CProjNode( Node *ctrl, uint idx ) : ProjNode(ctrl,idx) {}
312 virtual int Opcode() const;
313 virtual bool is_CFG() const { return true; }
314 virtual uint hash() const { return NO_HASH; } // CFG nodes do not hash
315 virtual const Node *is_block_proj() const { return in(0); }
316 virtual const RegMask &out_RegMask() const;
317 virtual uint ideal_reg() const { return 0; }
318 };
319
320 //---------------------------MultiBranchNode-----------------------------------
321 // This class defines a MultiBranchNode, a MultiNode which yields multiple
322 // control values. These are distinguished from other types of MultiNodes
323 // which yield multiple values, but control is always and only projection #0.
324 class MultiBranchNode : public MultiNode {
325 public:
326 MultiBranchNode( uint required ) : MultiNode(required) {
327 init_class_id(Class_MultiBranch);
328 }
329 // returns required number of users to be well formed.
330 virtual uint required_outcnt() const = 0;
331 };
332
333 //------------------------------IfNode-----------------------------------------
334 // Output selected Control, based on a boolean test
335 class IfNode : public MultiBranchNode {
336 public:
337 float _prob; // Probability of true path being taken.
338 float _fcnt; // Frequency counter
339
340 private:
341 AssertionPredicateType _assertion_predicate_type;
342
343 void init_node(Node* control, Node* bol) {
344 init_class_id(Class_If);
345 init_req(0, control);
346 init_req(1, bol);
347 }
348
349 // Size is bigger to hold the probability field. However, _prob does not
350 // change the semantics so it does not appear in the hash & cmp functions.
351 virtual uint size_of() const { return sizeof(*this); }
352
353 // Helper methods for fold_compares
354 bool cmpi_folds(PhaseIterGVN* igvn, bool fold_ne = false);
355 bool is_ctrl_folds(Node* ctrl, PhaseIterGVN* igvn);
356 bool has_shared_region(IfProjNode* proj, IfProjNode*& success, IfProjNode*& fail) const;
357 bool has_only_uncommon_traps(IfProjNode* proj, IfProjNode*& success, IfProjNode*& fail, PhaseIterGVN* igvn) const;
358 Node* merge_uncommon_traps(IfProjNode* proj, IfProjNode* success, IfProjNode* fail, PhaseIterGVN* igvn);
359 static void improve_address_types(Node* l, Node* r, ProjNode* fail, PhaseIterGVN* igvn);
360 bool is_cmp_with_loadrange(IfProjNode* proj) const;
361 bool is_null_check(IfProjNode* proj, PhaseIterGVN* igvn) const;
362 bool is_side_effect_free_test(IfProjNode* proj, PhaseIterGVN* igvn) const;
363 static void reroute_side_effect_free_unc(IfProjNode* proj, IfProjNode* dom_proj, PhaseIterGVN* igvn);
364 bool fold_compares_helper(IfProjNode* proj, IfProjNode* success, IfProjNode* fail, PhaseIterGVN* igvn);
365 static bool is_dominator_unc(CallStaticJavaNode* dom_unc, CallStaticJavaNode* unc);
366
367 protected:
368 IfProjNode* range_check_trap_proj(int& flip, Node*& l, Node*& r) const;
369 Node* Ideal_common(PhaseGVN *phase, bool can_reshape);
370 Node* search_identical(int dist, PhaseIterGVN* igvn);
371
372 Node* simple_subsuming(PhaseIterGVN* igvn);
373
374 public:
375
376 // Degrees of branch prediction probability by order of magnitude:
377 // PROB_UNLIKELY_1e(N) is a 1 in 1eN chance.
378 // PROB_LIKELY_1e(N) is a 1 - PROB_UNLIKELY_1e(N)
379 #define PROB_UNLIKELY_MAG(N) (1e- ## N ## f)
380 #define PROB_LIKELY_MAG(N) (1.0f-PROB_UNLIKELY_MAG(N))
381
382 // Maximum and minimum branch prediction probabilties
383 // 1 in 1,000,000 (magnitude 6)
384 //
385 // Although PROB_NEVER == PROB_MIN and PROB_ALWAYS == PROB_MAX
386 // they are used to distinguish different situations:
387 //
388 // The name PROB_MAX (PROB_MIN) is for probabilities which correspond to
389 // very likely (unlikely) but with a concrete possibility of a rare
390 // contrary case. These constants would be used for pinning
391 // measurements, and as measures for assertions that have high
392 // confidence, but some evidence of occasional failure.
393 //
394 // The name PROB_ALWAYS (PROB_NEVER) is to stand for situations for which
395 // there is no evidence at all that the contrary case has ever occurred.
396
397 #define PROB_NEVER PROB_UNLIKELY_MAG(6)
398 #define PROB_ALWAYS PROB_LIKELY_MAG(6)
399
400 #define PROB_MIN PROB_UNLIKELY_MAG(6)
401 #define PROB_MAX PROB_LIKELY_MAG(6)
402
403 // Static branch prediction probabilities
404 // 1 in 10 (magnitude 1)
405 #define PROB_STATIC_INFREQUENT PROB_UNLIKELY_MAG(1)
406 #define PROB_STATIC_FREQUENT PROB_LIKELY_MAG(1)
407
408 // Fair probability 50/50
409 #define PROB_FAIR (0.5f)
410
411 // Unknown probability sentinel
412 #define PROB_UNKNOWN (-1.0f)
413
414 // Probability "constructors", to distinguish as a probability any manifest
415 // constant without a names
416 #define PROB_LIKELY(x) ((float) (x))
417 #define PROB_UNLIKELY(x) (1.0f - (float)(x))
418
419 // Other probabilities in use, but without a unique name, are documented
420 // here for lack of a better place:
421 //
422 // 1 in 1000 probabilities (magnitude 3):
423 // threshold for converting to conditional move
424 // likelihood of null check failure if a null HAS been seen before
425 // likelihood of slow path taken in library calls
426 //
427 // 1 in 10,000 probabilities (magnitude 4):
428 // threshold for making an uncommon trap probability more extreme
429 // threshold for for making a null check implicit
430 // likelihood of needing a gc if eden top moves during an allocation
431 // likelihood of a predicted call failure
432 //
433 // 1 in 100,000 probabilities (magnitude 5):
434 // threshold for ignoring counts when estimating path frequency
435 // likelihood of FP clipping failure
436 // likelihood of catching an exception from a try block
437 // likelihood of null check failure if a null has NOT been seen before
438 //
439 // Magic manifest probabilities such as 0.83, 0.7, ... can be found in
440 // gen_subtype_check() and catch_inline_exceptions().
441
442 IfNode(Node* control, Node* bol, float p, float fcnt);
443 IfNode(Node* control, Node* bol, float p, float fcnt, AssertionPredicateType assertion_predicate_type);
444
445 static IfNode* make_with_same_profile(IfNode* if_node_profile, Node* ctrl, Node* bol);
446
447 IfTrueNode* true_proj() const {
448 return proj_out(true)->as_IfTrue();
449 }
450
451 IfTrueNode* true_proj_or_null() const {
452 ProjNode* true_proj = proj_out_or_null(true);
453 return true_proj == nullptr ? nullptr : true_proj->as_IfTrue();
454 }
455
456 IfFalseNode* false_proj() const {
457 return proj_out(false)->as_IfFalse();
458 }
459
460 IfFalseNode* false_proj_or_null() const {
461 ProjNode* false_proj = proj_out_or_null(false);
462 return false_proj == nullptr ? nullptr : false_proj->as_IfFalse();
463 }
464
465 virtual int Opcode() const;
466 virtual bool pinned() const { return true; }
467 virtual const Type *bottom_type() const { return TypeTuple::IFBOTH; }
468 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
469 virtual const Type* Value(PhaseGVN* phase) const;
470 virtual uint required_outcnt() const { return 2; }
471 virtual const RegMask &out_RegMask() const;
472 Node* fold_compares(PhaseIterGVN* phase);
473 static Node* up_one_dom(Node* curr, bool linear_only = false);
474 bool is_zero_trip_guard() const;
475 Node* dominated_by(Node* prev_dom, PhaseIterGVN* igvn, bool prev_dom_not_imply_this);
476 ProjNode* uncommon_trap_proj(CallStaticJavaNode*& call, Deoptimization::DeoptReason reason = Deoptimization::Reason_none) const;
477
478 // Takes the type of val and filters it through the test represented
479 // by if_proj and returns a more refined type if one is produced.
480 // Returns null is it couldn't improve the type.
481 static const TypeInt* filtered_int_type(PhaseGVN* phase, Node* val, Node* if_proj);
482
483 bool is_flat_array_check(PhaseTransform* phase, Node** array = nullptr);
484
485 AssertionPredicateType assertion_predicate_type() const {
486 return _assertion_predicate_type;
487 }
488
489 #ifndef PRODUCT
490 virtual void dump_spec(outputStream *st) const;
491 #endif
492
493 bool same_condition(const Node* dom, PhaseIterGVN* igvn) const;
494 void mark_projections_unsafe_for_fold_compare() const;
495 };
496
497 class RangeCheckNode : public IfNode {
498 private:
499 int is_range_check(Node*& range, Node*& index, jint& offset);
500
501 public:
502 RangeCheckNode(Node* control, Node* bol, float p, float fcnt) : IfNode(control, bol, p, fcnt) {
503 init_class_id(Class_RangeCheck);
504 }
505
506 RangeCheckNode(Node* control, Node* bol, float p, float fcnt, AssertionPredicateType assertion_predicate_type)
507 : IfNode(control, bol, p, fcnt, assertion_predicate_type) {
508 init_class_id(Class_RangeCheck);
509 }
510
511 virtual int Opcode() const;
512 virtual Node* Ideal(PhaseGVN *phase, bool can_reshape);
513 };
514
515 // Special node that denotes a Parse Predicate added during parsing. A Parse Predicate serves as placeholder to later
516 // create Regular Predicates (Runtime Predicates with possible Assertion Predicates) above it. Together they form a
517 // Predicate Block. The Parse Predicate and Regular Predicates share the same uncommon trap.
518 // There are three kinds of Parse Predicates:
519 // Loop Parse Predicate, Profiled Loop Parse Predicate (both used by Loop Predication), and Loop Limit Check Parse
520 // Predicate (used for integer overflow checks when creating a counted loop).
521 // More information about predicates can be found in loopPredicate.cpp.
522 class ParsePredicateNode : public IfNode {
523 Deoptimization::DeoptReason _deopt_reason;
524
525 // When a Parse Predicate loses its connection to a loop head, it will be marked useless by
526 // EliminateUselessPredicates and cleaned up by Value(). It can also become useless when cloning it to both loops
527 // during Loop Multiversioning - we no longer use the old version.
528 PredicateState _predicate_state;
529 public:
530 ParsePredicateNode(Node* control, Deoptimization::DeoptReason deopt_reason, PhaseGVN* gvn);
531 virtual int Opcode() const;
532 virtual uint size_of() const { return sizeof(*this); }
533
534 Deoptimization::DeoptReason deopt_reason() const {
535 return _deopt_reason;
536 }
537
538 bool is_useless() const {
539 return _predicate_state == PredicateState::Useless;
540 }
541
542 void mark_useless(PhaseIterGVN& igvn);
543
544 void mark_maybe_useful() {
545 _predicate_state = PredicateState::MaybeUseful;
546 }
547
548 bool is_useful() const {
549 return _predicate_state == PredicateState::Useful;
550 }
551
552 void mark_useful() {
553 _predicate_state = PredicateState::Useful;
554 }
555
556 // Return the uncommon trap If projection of this Parse Predicate.
557 ParsePredicateUncommonProj* uncommon_proj() const {
558 return false_proj();
559 }
560
561 Node* uncommon_trap() const;
562
563 Node* Ideal(PhaseGVN* phase, bool can_reshape) {
564 return nullptr; // Don't optimize
565 }
566
567 const Type* Value(PhaseGVN* phase) const;
568 NOT_PRODUCT(void dump_spec(outputStream* st) const;)
569 };
570
571 class IfProjNode : public CProjNode {
572 public:
573 IfProjNode(IfNode *ifnode, uint idx) : CProjNode(ifnode,idx) {}
574 virtual Node* Identity(PhaseGVN* phase);
575
576 // Return the other IfProj node.
577 IfProjNode* other_if_proj() const {
578 return in(0)->as_If()->proj_out(1 - _con)->as_IfProj();
579 }
580
581 void pin_dependent_nodes(PhaseIterGVN* igvn);
582
583 protected:
584 // Type of If input when this branch is always taken
585 virtual bool always_taken(const TypeTuple* t) const = 0;
586 };
587
588 class IfTrueNode : public IfProjNode {
589 public:
590 IfTrueNode( IfNode *ifnode ) : IfProjNode(ifnode,1) {
591 init_class_id(Class_IfTrue);
592 }
593 virtual int Opcode() const;
594
595 protected:
596 virtual bool always_taken(const TypeTuple* t) const { return t == TypeTuple::IFTRUE; }
597 };
598
599 class IfFalseNode : public IfProjNode {
600 public:
601 IfFalseNode( IfNode *ifnode ) : IfProjNode(ifnode,0) {
602 init_class_id(Class_IfFalse);
603 }
604 virtual int Opcode() const;
605
606 protected:
607 virtual bool always_taken(const TypeTuple* t) const { return t == TypeTuple::IFFALSE; }
608 };
609
610
611 //------------------------------PCTableNode------------------------------------
612 // Build an indirect branch table. Given a control and a table index,
613 // control is passed to the Projection matching the table index. Used to
614 // implement switch statements and exception-handling capabilities.
615 // Undefined behavior if passed-in index is not inside the table.
616 class PCTableNode : public MultiBranchNode {
617 virtual uint hash() const; // Target count; table size
618 virtual bool cmp( const Node &n ) const;
619 virtual uint size_of() const { return sizeof(*this); }
620
621 public:
622 const uint _size; // Number of targets
623
624 PCTableNode( Node *ctrl, Node *idx, uint size ) : MultiBranchNode(2), _size(size) {
625 init_class_id(Class_PCTable);
626 init_req(0, ctrl);
627 init_req(1, idx);
628 }
629 virtual int Opcode() const;
630 virtual const Type* Value(PhaseGVN* phase) const;
631 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
632 virtual const Type *bottom_type() const;
633 virtual bool pinned() const { return true; }
634 virtual uint required_outcnt() const { return _size; }
635 };
636
637 //------------------------------JumpNode---------------------------------------
638 // Indirect branch. Uses PCTable above to implement a switch statement.
639 // It emits as a table load and local branch.
640 class JumpNode : public PCTableNode {
641 virtual uint size_of() const { return sizeof(*this); }
642 public:
643 float* _probs; // probability of each projection
644 float _fcnt; // total number of times this Jump was executed
645 JumpNode( Node* control, Node* switch_val, uint size, float* probs, float cnt)
646 : PCTableNode(control, switch_val, size),
647 _probs(probs), _fcnt(cnt) {
648 init_class_id(Class_Jump);
649 }
650 virtual int Opcode() const;
651 virtual const RegMask& out_RegMask() const;
652 virtual const Node* is_block_proj() const { return this; }
653 };
654
655 class JumpProjNode : public JProjNode {
656 virtual uint hash() const;
657 virtual bool cmp( const Node &n ) const;
658 virtual uint size_of() const { return sizeof(*this); }
659
660 private:
661 const int _dest_bci;
662 const uint _proj_no;
663 const int _switch_val;
664 public:
665 JumpProjNode(Node* jumpnode, uint proj_no, int dest_bci, int switch_val)
666 : JProjNode(jumpnode, proj_no), _dest_bci(dest_bci), _proj_no(proj_no), _switch_val(switch_val) {
667 init_class_id(Class_JumpProj);
668 }
669
670 virtual int Opcode() const;
671 virtual const Type* bottom_type() const { return Type::CONTROL; }
672 int dest_bci() const { return _dest_bci; }
673 int switch_val() const { return _switch_val; }
674 uint proj_no() const { return _proj_no; }
675 #ifndef PRODUCT
676 virtual void dump_spec(outputStream *st) const;
677 virtual void dump_compact_spec(outputStream *st) const;
678 #endif
679 };
680
681 //------------------------------CatchNode--------------------------------------
682 // Helper node to fork exceptions. "Catch" catches any exceptions thrown by
683 // a just-prior call. Looks like a PCTableNode but emits no code - just the
684 // table. The table lookup and branch is implemented by RethrowNode.
685 class CatchNode : public PCTableNode {
686 public:
687 CatchNode( Node *ctrl, Node *idx, uint size ) : PCTableNode(ctrl,idx,size){
688 init_class_id(Class_Catch);
689 }
690 virtual int Opcode() const;
691 virtual const Type* Value(PhaseGVN* phase) const;
692 };
693
694 // CatchProjNode controls which exception handler is targeted after a call.
695 // It is passed in the bci of the target handler, or no_handler_bci in case
696 // the projection doesn't lead to an exception handler.
697 class CatchProjNode : public CProjNode {
698 virtual uint hash() const;
699 virtual bool cmp( const Node &n ) const;
700 virtual uint size_of() const { return sizeof(*this); }
701
702 private:
703 const int _handler_bci;
704
705 public:
706 enum {
707 fall_through_index = 0, // the fall through projection index
708 catch_all_index = 1, // the projection index for catch-alls
709 no_handler_bci = -1 // the bci for fall through or catch-all projs
710 };
711
712 CatchProjNode(Node* catchnode, uint proj_no, int handler_bci)
713 : CProjNode(catchnode, proj_no), _handler_bci(handler_bci) {
714 init_class_id(Class_CatchProj);
715 assert(proj_no != fall_through_index || handler_bci < 0, "fall through case must have bci < 0");
716 }
717
718 virtual int Opcode() const;
719 virtual Node* Identity(PhaseGVN* phase);
720 virtual const Type *bottom_type() const { return Type::CONTROL; }
721 int handler_bci() const { return _handler_bci; }
722 bool is_handler_proj() const { return _handler_bci >= 0; }
723 #ifndef PRODUCT
724 virtual void dump_spec(outputStream *st) const;
725 #endif
726 };
727
728
729 //---------------------------------CreateExNode--------------------------------
730 // Helper node to create the exception coming back from a call
731 class CreateExNode : public TypeNode {
732 public:
733 CreateExNode(const Type* t, Node* control, Node* i_o) : TypeNode(t, 2) {
734 init_req(0, control);
735 init_req(1, i_o);
736 }
737 virtual int Opcode() const;
738 virtual Node* Identity(PhaseGVN* phase);
739 virtual bool pinned() const { return true; }
740 uint match_edge(uint idx) const { return 0; }
741 virtual uint ideal_reg() const { return Op_RegP; }
742 };
743
744 //------------------------------NeverBranchNode-------------------------------
745 // The never-taken branch. Used to give the appearance of exiting infinite
746 // loops to those algorithms that like all paths to be reachable. Encodes
747 // empty.
748 class NeverBranchNode : public MultiBranchNode {
749 public:
750 NeverBranchNode(Node* ctrl) : MultiBranchNode(1) {
751 init_req(0, ctrl);
752 init_class_id(Class_NeverBranch);
753 }
754 virtual int Opcode() const;
755 virtual bool pinned() const { return true; };
756 virtual const Type *bottom_type() const { return TypeTuple::IFBOTH; }
757 virtual const Type* Value(PhaseGVN* phase) const;
758 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
759 virtual uint required_outcnt() const { return 2; }
760 virtual void emit(C2_MacroAssembler *masm, PhaseRegAlloc *ra_) const { }
761 virtual uint size(PhaseRegAlloc *ra_) const { return 0; }
762 #ifndef PRODUCT
763 virtual void format( PhaseRegAlloc *, outputStream *st ) const;
764 #endif
765 };
766
767 //------------------------------BlackholeNode----------------------------
768 // Blackhole all arguments. This node would survive through the compiler
769 // the effects on its arguments, and would be finally matched to nothing.
770 class BlackholeNode : public MultiNode {
771 public:
772 BlackholeNode(Node* ctrl) : MultiNode(1) {
773 init_req(TypeFunc::Control, ctrl);
774 init_class_id(Class_Blackhole);
775 }
776 virtual int Opcode() const;
777 virtual uint ideal_reg() const { return 0; } // not matched in the AD file
778 virtual const Type* bottom_type() const { return TypeTuple::MEMBAR; }
779 virtual Node* Ideal(PhaseGVN* phase, bool can_reshape);
780
781 const RegMask &in_RegMask(uint idx) const {
782 // Fake the incoming arguments mask for blackholes: accept all registers
783 // and all stack slots. This would avoid any redundant register moves
784 // for blackhole inputs.
785 return RegMask::ALL;
786 }
787 #ifndef PRODUCT
788 virtual void format(PhaseRegAlloc* ra, outputStream* st) const;
789 #endif
790 };
791
792
793 #endif // SHARE_OPTO_CFGNODE_HPP