1 /*
2 * Copyright (c) 1997, 2025, 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
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11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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13 * accompanied this code).
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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
34 // Portions of code courtesy of Clifford Click
35
36 // Optimization - Graph Style
37
38 class Matcher;
39 class Node;
40 class RegionNode;
41 class TypeNode;
42 class PhiNode;
43 class GotoNode;
44 class MultiNode;
45 class MultiBranchNode;
46 class IfNode;
47 class PCTableNode;
48 class JumpNode;
49 class CatchNode;
50 class NeverBranchNode;
51 class BlackholeNode;
52 class ProjNode;
53 class CProjNode;
54 class IfTrueNode;
55 class IfFalseNode;
56 class CatchProjNode;
57 class JProjNode;
58 class JumpProjNode;
59 class SCMemProjNode;
60 class PhaseIdealLoop;
61 enum class AssertionPredicateType;
62 enum class PredicateState;
63
64 //------------------------------RegionNode-------------------------------------
65 // The class of RegionNodes, which can be mapped to basic blocks in the
66 // program. Their inputs point to Control sources. PhiNodes (described
67 // below) have an input point to a RegionNode. Merged data inputs to PhiNodes
68 // correspond 1-to-1 with RegionNode inputs. The zero input of a PhiNode is
69 // the RegionNode, and the zero input of the RegionNode is itself.
70 class RegionNode : public Node {
71 public:
72 enum LoopStatus {
73 // No guarantee: the region may be an irreducible loop entry, thus we have to
74 // be careful when removing entry control to it.
75 MaybeIrreducibleEntry,
76 // Limited guarantee: this region may be (nested) inside an irreducible loop,
77 // but it will never be an irreducible loop entry.
78 NeverIrreducibleEntry,
79 // Strong guarantee: this region is not (nested) inside an irreducible loop.
80 Reducible,
81 };
82
83 private:
84 bool _is_unreachable_region;
85 LoopStatus _loop_status;
86
87 bool is_possible_unsafe_loop(const PhaseGVN* phase) const;
88 bool is_unreachable_from_root(const PhaseGVN* phase) const;
89 public:
90 // Node layout (parallels PhiNode):
91 enum { Region, // Generally points to self.
92 Control // Control arcs are [1..len)
93 };
94
95 RegionNode(uint required)
96 : Node(required),
97 _is_unreachable_region(false),
98 _loop_status(LoopStatus::NeverIrreducibleEntry)
99 {
100 init_class_id(Class_Region);
101 init_req(0, this);
102 }
103
104 Node* is_copy() const {
105 const Node* r = _in[Region];
106 if (r == nullptr)
107 return nonnull_req();
108 return nullptr; // not a copy!
109 }
110 PhiNode* has_phi() const; // returns an arbitrary phi user, or null
111 PhiNode* has_unique_phi() const; // returns the unique phi user, or null
112 // Is this region node unreachable from root?
113 bool is_unreachable_region(const PhaseGVN* phase);
114 #ifdef ASSERT
115 bool is_in_infinite_subgraph();
116 static bool are_all_nodes_in_infinite_subgraph(Unique_Node_List& worklist);
117 #endif //ASSERT
118 LoopStatus loop_status() const { return _loop_status; };
119 void set_loop_status(LoopStatus status);
120 bool can_be_irreducible_entry() const;
121
122 virtual int Opcode() const;
123 virtual uint size_of() const { return sizeof(*this); }
124 virtual bool pinned() const { return (const Node*)in(0) == this; }
125 virtual bool is_CFG() const { return true; }
126 virtual uint hash() const { return NO_HASH; } // CFG nodes do not hash
127 virtual bool depends_only_on_test() const { return false; }
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 is_split_through_mergemem_terminating() const;
184
185 public:
186 // Node layout (parallels RegionNode):
187 enum { Region, // Control input is the Phi's region.
188 Input // Input values are [1..len)
189 };
190
191 PhiNode( Node *r, const Type *t, const TypePtr* at = nullptr,
192 const int imid = -1,
193 const int iid = TypeOopPtr::InstanceTop,
194 const int iidx = Compile::AliasIdxTop,
195 const int ioffs = Type::OffsetTop )
196 : TypeNode(t,r->req()),
197 _adr_type(at),
198 _inst_mem_id(imid),
199 _inst_id(iid),
200 _inst_index(iidx),
201 _inst_offset(ioffs)
202 {
203 init_class_id(Class_Phi);
204 init_req(0, r);
205 verify_adr_type();
206 }
207 // create a new phi with in edges matching r and set (initially) to x
208 static PhiNode* make( Node* r, Node* x );
209 // extra type arguments override the new phi's bottom_type and adr_type
210 static PhiNode* make( Node* r, Node* x, const Type *t, const TypePtr* at = nullptr );
211 // create a new phi with narrowed memory type
212 PhiNode* slice_memory(const TypePtr* adr_type) const;
213 PhiNode* split_out_instance(const TypePtr* at, PhaseIterGVN *igvn) const;
214 // like make(r, x), but does not initialize the in edges to x
215 static PhiNode* make_blank( Node* r, Node* x );
216
217 // Accessors
218 RegionNode* region() const { Node* r = in(Region); assert(!r || r->is_Region(), ""); return (RegionNode*)r; }
219
220 bool is_tripcount(BasicType bt) const;
221
222 // Determine a unique non-trivial input, if any.
223 // Ignore casts if it helps. Return null on failure.
224 Node* unique_input(PhaseValues* phase, bool uncast);
225 Node* unique_input(PhaseValues* phase) {
226 Node* uin = unique_input(phase, false);
227 if (uin == nullptr) {
228 uin = unique_input(phase, true);
229 }
230 return uin;
231 }
232
233 // Check for a simple dead loop.
234 enum LoopSafety { Safe = 0, Unsafe, UnsafeLoop };
235 LoopSafety simple_data_loop_check(Node *in) const;
236 // Is it unsafe data loop? It becomes a dead loop if this phi node removed.
237 bool is_unsafe_data_reference(Node *in) const;
238 int is_diamond_phi() const;
239 bool try_clean_memory_phi(PhaseIterGVN* igvn);
240 virtual int Opcode() const;
241 virtual bool pinned() const { return in(0) != nullptr; }
242 virtual const TypePtr *adr_type() const { verify_adr_type(true); return _adr_type; }
243
244 void set_inst_mem_id(int inst_mem_id) { _inst_mem_id = inst_mem_id; }
245 int inst_mem_id() const { return _inst_mem_id; }
246 int inst_id() const { return _inst_id; }
247 int inst_index() const { return _inst_index; }
248 int inst_offset() const { return _inst_offset; }
249 bool is_same_inst_field(const Type* tp, int mem_id, int id, int index, int offset) {
250 return type()->basic_type() == tp->basic_type() &&
251 inst_mem_id() == mem_id &&
252 inst_id() == id &&
253 inst_index() == index &&
254 inst_offset() == offset &&
255 type()->higher_equal(tp);
256 }
257
258 virtual const Type* Value(PhaseGVN* phase) const;
259 virtual Node* Identity(PhaseGVN* phase);
260 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
261 virtual const RegMask &out_RegMask() const;
262 virtual const RegMask &in_RegMask(uint) const;
263 #ifndef PRODUCT
264 virtual void dump_spec(outputStream *st) const;
265 #endif
266 #ifdef ASSERT
267 void verify_adr_type(VectorSet& visited, const TypePtr* at) const;
268 void verify_adr_type(bool recursive = false) const;
269 #else //ASSERT
270 void verify_adr_type(bool recursive = false) const {}
271 #endif //ASSERT
272
273 const TypeTuple* collect_types(PhaseGVN* phase) const;
274 };
275
276 //------------------------------GotoNode---------------------------------------
277 // GotoNodes perform direct branches.
278 class GotoNode : public Node {
279 public:
280 GotoNode( Node *control ) : Node(control) {}
281 virtual int Opcode() const;
282 virtual bool pinned() const { return true; }
283 virtual bool is_CFG() const { return true; }
284 virtual uint hash() const { return NO_HASH; } // CFG nodes do not hash
285 virtual const Node *is_block_proj() const { return this; }
286 virtual bool depends_only_on_test() const { return false; }
287 virtual const Type *bottom_type() const { return Type::CONTROL; }
288 virtual const Type* Value(PhaseGVN* phase) const;
289 virtual Node* Identity(PhaseGVN* phase);
290 virtual const RegMask &out_RegMask() const;
291 };
292
293 //------------------------------CProjNode--------------------------------------
294 // control projection for node that produces multiple control-flow paths
295 class CProjNode : public ProjNode {
296 public:
297 CProjNode( Node *ctrl, uint idx ) : ProjNode(ctrl,idx) {}
298 virtual int Opcode() const;
299 virtual bool is_CFG() const { return true; }
300 virtual uint hash() const { return NO_HASH; } // CFG nodes do not hash
301 virtual const Node *is_block_proj() const { return in(0); }
302 virtual const RegMask &out_RegMask() const;
303 virtual uint ideal_reg() const { return 0; }
304 };
305
306 //---------------------------MultiBranchNode-----------------------------------
307 // This class defines a MultiBranchNode, a MultiNode which yields multiple
308 // control values. These are distinguished from other types of MultiNodes
309 // which yield multiple values, but control is always and only projection #0.
310 class MultiBranchNode : public MultiNode {
311 public:
312 MultiBranchNode( uint required ) : MultiNode(required) {
313 init_class_id(Class_MultiBranch);
314 }
315 // returns required number of users to be well formed.
316 virtual int required_outcnt() const = 0;
317 };
318
319 //------------------------------IfNode-----------------------------------------
320 // Output selected Control, based on a boolean test
321 class IfNode : public MultiBranchNode {
322 public:
323 float _prob; // Probability of true path being taken.
324 float _fcnt; // Frequency counter
325
326 private:
327 AssertionPredicateType _assertion_predicate_type;
328
329 void init_node(Node* control, Node* bol) {
330 init_class_id(Class_If);
331 init_req(0, control);
332 init_req(1, bol);
333 }
334
335 // Size is bigger to hold the probability field. However, _prob does not
336 // change the semantics so it does not appear in the hash & cmp functions.
337 virtual uint size_of() const { return sizeof(*this); }
338
339 // Helper methods for fold_compares
340 bool cmpi_folds(PhaseIterGVN* igvn, bool fold_ne = false);
341 bool is_ctrl_folds(Node* ctrl, PhaseIterGVN* igvn);
342 bool has_shared_region(ProjNode* proj, ProjNode*& success, ProjNode*& fail);
343 bool has_only_uncommon_traps(ProjNode* proj, ProjNode*& success, ProjNode*& fail, PhaseIterGVN* igvn);
344 Node* merge_uncommon_traps(ProjNode* proj, ProjNode* success, ProjNode* fail, PhaseIterGVN* igvn);
345 static void improve_address_types(Node* l, Node* r, ProjNode* fail, PhaseIterGVN* igvn);
346 bool is_cmp_with_loadrange(ProjNode* proj);
347 bool is_null_check(ProjNode* proj, PhaseIterGVN* igvn);
348 bool is_side_effect_free_test(ProjNode* proj, PhaseIterGVN* igvn);
349 void reroute_side_effect_free_unc(ProjNode* proj, ProjNode* dom_proj, PhaseIterGVN* igvn);
350 bool fold_compares_helper(ProjNode* proj, ProjNode* success, ProjNode* fail, PhaseIterGVN* igvn);
351 static bool is_dominator_unc(CallStaticJavaNode* dom_unc, CallStaticJavaNode* unc);
352
353 protected:
354 ProjNode* range_check_trap_proj(int& flip, Node*& l, Node*& r);
355 Node* Ideal_common(PhaseGVN *phase, bool can_reshape);
356 Node* search_identical(int dist, PhaseIterGVN* igvn);
357
358 Node* simple_subsuming(PhaseIterGVN* igvn);
359
360 public:
361
362 // Degrees of branch prediction probability by order of magnitude:
363 // PROB_UNLIKELY_1e(N) is a 1 in 1eN chance.
364 // PROB_LIKELY_1e(N) is a 1 - PROB_UNLIKELY_1e(N)
365 #define PROB_UNLIKELY_MAG(N) (1e- ## N ## f)
366 #define PROB_LIKELY_MAG(N) (1.0f-PROB_UNLIKELY_MAG(N))
367
368 // Maximum and minimum branch prediction probabilties
369 // 1 in 1,000,000 (magnitude 6)
370 //
371 // Although PROB_NEVER == PROB_MIN and PROB_ALWAYS == PROB_MAX
372 // they are used to distinguish different situations:
373 //
374 // The name PROB_MAX (PROB_MIN) is for probabilities which correspond to
375 // very likely (unlikely) but with a concrete possibility of a rare
376 // contrary case. These constants would be used for pinning
377 // measurements, and as measures for assertions that have high
378 // confidence, but some evidence of occasional failure.
379 //
380 // The name PROB_ALWAYS (PROB_NEVER) is to stand for situations for which
381 // there is no evidence at all that the contrary case has ever occurred.
382
383 #define PROB_NEVER PROB_UNLIKELY_MAG(6)
384 #define PROB_ALWAYS PROB_LIKELY_MAG(6)
385
386 #define PROB_MIN PROB_UNLIKELY_MAG(6)
387 #define PROB_MAX PROB_LIKELY_MAG(6)
388
389 // Static branch prediction probabilities
390 // 1 in 10 (magnitude 1)
391 #define PROB_STATIC_INFREQUENT PROB_UNLIKELY_MAG(1)
392 #define PROB_STATIC_FREQUENT PROB_LIKELY_MAG(1)
393
394 // Fair probability 50/50
395 #define PROB_FAIR (0.5f)
396
397 // Unknown probability sentinel
398 #define PROB_UNKNOWN (-1.0f)
399
400 // Probability "constructors", to distinguish as a probability any manifest
401 // constant without a names
402 #define PROB_LIKELY(x) ((float) (x))
403 #define PROB_UNLIKELY(x) (1.0f - (float)(x))
404
405 // Other probabilities in use, but without a unique name, are documented
406 // here for lack of a better place:
407 //
408 // 1 in 1000 probabilities (magnitude 3):
409 // threshold for converting to conditional move
410 // likelihood of null check failure if a null HAS been seen before
411 // likelihood of slow path taken in library calls
412 //
413 // 1 in 10,000 probabilities (magnitude 4):
414 // threshold for making an uncommon trap probability more extreme
415 // threshold for for making a null check implicit
416 // likelihood of needing a gc if eden top moves during an allocation
417 // likelihood of a predicted call failure
418 //
419 // 1 in 100,000 probabilities (magnitude 5):
420 // threshold for ignoring counts when estimating path frequency
421 // likelihood of FP clipping failure
422 // likelihood of catching an exception from a try block
423 // likelihood of null check failure if a null has NOT been seen before
424 //
425 // Magic manifest probabilities such as 0.83, 0.7, ... can be found in
426 // gen_subtype_check() and catch_inline_exceptions().
427
428 IfNode(Node* control, Node* bol, float p, float fcnt);
429 IfNode(Node* control, Node* bol, float p, float fcnt, AssertionPredicateType assertion_predicate_type);
430
431 static IfNode* make_with_same_profile(IfNode* if_node_profile, Node* ctrl, Node* bol);
432
433 virtual int Opcode() const;
434 virtual bool pinned() const { return true; }
435 virtual const Type *bottom_type() const { return TypeTuple::IFBOTH; }
436 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
437 virtual const Type* Value(PhaseGVN* phase) const;
438 virtual int required_outcnt() const { return 2; }
439 virtual const RegMask &out_RegMask() const;
440 Node* fold_compares(PhaseIterGVN* phase);
441 static Node* up_one_dom(Node* curr, bool linear_only = false);
442 bool is_zero_trip_guard() const;
443 Node* dominated_by(Node* prev_dom, PhaseIterGVN* igvn, bool pin_array_access_nodes);
444 ProjNode* uncommon_trap_proj(CallStaticJavaNode*& call, Deoptimization::DeoptReason reason = Deoptimization::Reason_none) const;
445
446 // Takes the type of val and filters it through the test represented
447 // by if_proj and returns a more refined type if one is produced.
448 // Returns null is it couldn't improve the type.
449 static const TypeInt* filtered_int_type(PhaseGVN* phase, Node* val, Node* if_proj);
450
451 AssertionPredicateType assertion_predicate_type() const {
452 return _assertion_predicate_type;
453 }
454
455 #ifndef PRODUCT
456 virtual void dump_spec(outputStream *st) const;
457 #endif
458
459 bool same_condition(const Node* dom, PhaseIterGVN* igvn) const;
460 };
461
462 class RangeCheckNode : public IfNode {
463 private:
464 int is_range_check(Node*& range, Node*& index, jint& offset);
465
466 public:
467 RangeCheckNode(Node* control, Node* bol, float p, float fcnt) : IfNode(control, bol, p, fcnt) {
468 init_class_id(Class_RangeCheck);
469 }
470
471 RangeCheckNode(Node* control, Node* bol, float p, float fcnt, AssertionPredicateType assertion_predicate_type)
472 : IfNode(control, bol, p, fcnt, assertion_predicate_type) {
473 init_class_id(Class_RangeCheck);
474 }
475
476 virtual int Opcode() const;
477 virtual Node* Ideal(PhaseGVN *phase, bool can_reshape);
478 };
479
480 // Special node that denotes a Parse Predicate added during parsing. A Parse Predicate serves as placeholder to later
481 // create Regular Predicates (Runtime Predicates with possible Assertion Predicates) above it. Together they form a
482 // Predicate Block. The Parse Predicate and Regular Predicates share the same uncommon trap.
483 // There are three kinds of Parse Predicates:
484 // Loop Parse Predicate, Profiled Loop Parse Predicate (both used by Loop Predication), and Loop Limit Check Parse
485 // Predicate (used for integer overflow checks when creating a counted loop).
486 // More information about predicates can be found in loopPredicate.cpp.
487 class ParsePredicateNode : public IfNode {
488 Deoptimization::DeoptReason _deopt_reason;
489
490 // When a Parse Predicate loses its connection to a loop head, it will be marked useless by
491 // EliminateUselessPredicates and cleaned up by Value(). It can also become useless when cloning it to both loops
492 // during Loop Multiversioning - we no longer use the old version.
493 PredicateState _predicate_state;
494 public:
495 ParsePredicateNode(Node* control, Deoptimization::DeoptReason deopt_reason, PhaseGVN* gvn);
496 virtual int Opcode() const;
497 virtual uint size_of() const { return sizeof(*this); }
498
499 Deoptimization::DeoptReason deopt_reason() const {
500 return _deopt_reason;
501 }
502
503 bool is_useless() const {
504 return _predicate_state == PredicateState::Useless;
505 }
506
507 void mark_useless(PhaseIterGVN& igvn);
508
509 void mark_maybe_useful() {
510 _predicate_state = PredicateState::MaybeUseful;
511 }
512
513 bool is_useful() const {
514 return _predicate_state == PredicateState::Useful;
515 }
516
517 void mark_useful() {
518 _predicate_state = PredicateState::Useful;
519 }
520
521 // Return the uncommon trap If projection of this Parse Predicate.
522 ParsePredicateUncommonProj* uncommon_proj() const {
523 return proj_out(0)->as_IfFalse();
524 }
525
526 Node* uncommon_trap() const;
527
528 Node* Ideal(PhaseGVN* phase, bool can_reshape) {
529 return nullptr; // Don't optimize
530 }
531
532 const Type* Value(PhaseGVN* phase) const;
533 NOT_PRODUCT(void dump_spec(outputStream* st) const;)
534 };
535
536 class IfProjNode : public CProjNode {
537 public:
538 IfProjNode(IfNode *ifnode, uint idx) : CProjNode(ifnode,idx) {}
539 virtual Node* Identity(PhaseGVN* phase);
540
541 void pin_array_access_nodes(PhaseIterGVN* igvn);
542
543 protected:
544 // Type of If input when this branch is always taken
545 virtual bool always_taken(const TypeTuple* t) const = 0;
546 };
547
548 class IfTrueNode : public IfProjNode {
549 public:
550 IfTrueNode( IfNode *ifnode ) : IfProjNode(ifnode,1) {
551 init_class_id(Class_IfTrue);
552 }
553 virtual int Opcode() const;
554
555 protected:
556 virtual bool always_taken(const TypeTuple* t) const { return t == TypeTuple::IFTRUE; }
557 };
558
559 class IfFalseNode : public IfProjNode {
560 public:
561 IfFalseNode( IfNode *ifnode ) : IfProjNode(ifnode,0) {
562 init_class_id(Class_IfFalse);
563 }
564 virtual int Opcode() const;
565
566 protected:
567 virtual bool always_taken(const TypeTuple* t) const { return t == TypeTuple::IFFALSE; }
568 };
569
570
571 //------------------------------PCTableNode------------------------------------
572 // Build an indirect branch table. Given a control and a table index,
573 // control is passed to the Projection matching the table index. Used to
574 // implement switch statements and exception-handling capabilities.
575 // Undefined behavior if passed-in index is not inside the table.
576 class PCTableNode : public MultiBranchNode {
577 virtual uint hash() const; // Target count; table size
578 virtual bool cmp( const Node &n ) const;
579 virtual uint size_of() const { return sizeof(*this); }
580
581 public:
582 const uint _size; // Number of targets
583
584 PCTableNode( Node *ctrl, Node *idx, uint size ) : MultiBranchNode(2), _size(size) {
585 init_class_id(Class_PCTable);
586 init_req(0, ctrl);
587 init_req(1, idx);
588 }
589 virtual int Opcode() const;
590 virtual const Type* Value(PhaseGVN* phase) const;
591 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
592 virtual const Type *bottom_type() const;
593 virtual bool pinned() const { return true; }
594 virtual int required_outcnt() const { return _size; }
595 };
596
597 //------------------------------JumpNode---------------------------------------
598 // Indirect branch. Uses PCTable above to implement a switch statement.
599 // It emits as a table load and local branch.
600 class JumpNode : public PCTableNode {
601 virtual uint size_of() const { return sizeof(*this); }
602 public:
603 float* _probs; // probability of each projection
604 float _fcnt; // total number of times this Jump was executed
605 JumpNode( Node* control, Node* switch_val, uint size, float* probs, float cnt)
606 : PCTableNode(control, switch_val, size),
607 _probs(probs), _fcnt(cnt) {
608 init_class_id(Class_Jump);
609 }
610 virtual int Opcode() const;
611 virtual const RegMask& out_RegMask() const;
612 virtual const Node* is_block_proj() const { return this; }
613 };
614
615 class JumpProjNode : public JProjNode {
616 virtual uint hash() const;
617 virtual bool cmp( const Node &n ) const;
618 virtual uint size_of() const { return sizeof(*this); }
619
620 private:
621 const int _dest_bci;
622 const uint _proj_no;
623 const int _switch_val;
624 public:
625 JumpProjNode(Node* jumpnode, uint proj_no, int dest_bci, int switch_val)
626 : JProjNode(jumpnode, proj_no), _dest_bci(dest_bci), _proj_no(proj_no), _switch_val(switch_val) {
627 init_class_id(Class_JumpProj);
628 }
629
630 virtual int Opcode() const;
631 virtual const Type* bottom_type() const { return Type::CONTROL; }
632 int dest_bci() const { return _dest_bci; }
633 int switch_val() const { return _switch_val; }
634 uint proj_no() const { return _proj_no; }
635 #ifndef PRODUCT
636 virtual void dump_spec(outputStream *st) const;
637 virtual void dump_compact_spec(outputStream *st) const;
638 #endif
639 };
640
641 //------------------------------CatchNode--------------------------------------
642 // Helper node to fork exceptions. "Catch" catches any exceptions thrown by
643 // a just-prior call. Looks like a PCTableNode but emits no code - just the
644 // table. The table lookup and branch is implemented by RethrowNode.
645 class CatchNode : public PCTableNode {
646 public:
647 CatchNode( Node *ctrl, Node *idx, uint size ) : PCTableNode(ctrl,idx,size){
648 init_class_id(Class_Catch);
649 }
650 virtual int Opcode() const;
651 virtual const Type* Value(PhaseGVN* phase) const;
652 };
653
654 // CatchProjNode controls which exception handler is targeted after a call.
655 // It is passed in the bci of the target handler, or no_handler_bci in case
656 // the projection doesn't lead to an exception handler.
657 class CatchProjNode : public CProjNode {
658 virtual uint hash() const;
659 virtual bool cmp( const Node &n ) const;
660 virtual uint size_of() const { return sizeof(*this); }
661
662 private:
663 const int _handler_bci;
664
665 public:
666 enum {
667 fall_through_index = 0, // the fall through projection index
668 catch_all_index = 1, // the projection index for catch-alls
669 no_handler_bci = -1 // the bci for fall through or catch-all projs
670 };
671
672 CatchProjNode(Node* catchnode, uint proj_no, int handler_bci)
673 : CProjNode(catchnode, proj_no), _handler_bci(handler_bci) {
674 init_class_id(Class_CatchProj);
675 assert(proj_no != fall_through_index || handler_bci < 0, "fall through case must have bci < 0");
676 }
677
678 virtual int Opcode() const;
679 virtual Node* Identity(PhaseGVN* phase);
680 virtual const Type *bottom_type() const { return Type::CONTROL; }
681 int handler_bci() const { return _handler_bci; }
682 bool is_handler_proj() const { return _handler_bci >= 0; }
683 #ifndef PRODUCT
684 virtual void dump_spec(outputStream *st) const;
685 #endif
686 };
687
688
689 //---------------------------------CreateExNode--------------------------------
690 // Helper node to create the exception coming back from a call
691 class CreateExNode : public TypeNode {
692 public:
693 CreateExNode(const Type* t, Node* control, Node* i_o) : TypeNode(t, 2) {
694 init_req(0, control);
695 init_req(1, i_o);
696 }
697 virtual int Opcode() const;
698 virtual Node* Identity(PhaseGVN* phase);
699 virtual bool pinned() const { return true; }
700 uint match_edge(uint idx) const { return 0; }
701 virtual uint ideal_reg() const { return Op_RegP; }
702 };
703
704 //------------------------------NeverBranchNode-------------------------------
705 // The never-taken branch. Used to give the appearance of exiting infinite
706 // loops to those algorithms that like all paths to be reachable. Encodes
707 // empty.
708 class NeverBranchNode : public MultiBranchNode {
709 public:
710 NeverBranchNode(Node* ctrl) : MultiBranchNode(1) {
711 init_req(0, ctrl);
712 init_class_id(Class_NeverBranch);
713 }
714 virtual int Opcode() const;
715 virtual bool pinned() const { return true; };
716 virtual const Type *bottom_type() const { return TypeTuple::IFBOTH; }
717 virtual const Type* Value(PhaseGVN* phase) const;
718 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
719 virtual int required_outcnt() const { return 2; }
720 virtual void emit(C2_MacroAssembler *masm, PhaseRegAlloc *ra_) const { }
721 virtual uint size(PhaseRegAlloc *ra_) const { return 0; }
722 #ifndef PRODUCT
723 virtual void format( PhaseRegAlloc *, outputStream *st ) const;
724 #endif
725 };
726
727 //------------------------------BlackholeNode----------------------------
728 // Blackhole all arguments. This node would survive through the compiler
729 // the effects on its arguments, and would be finally matched to nothing.
730 class BlackholeNode : public MultiNode {
731 public:
732 BlackholeNode(Node* ctrl) : MultiNode(1) {
733 init_req(TypeFunc::Control, ctrl);
734 }
735 virtual int Opcode() const;
736 virtual uint ideal_reg() const { return 0; } // not matched in the AD file
737 virtual const Type* bottom_type() const { return TypeTuple::MEMBAR; }
738
739 const RegMask &in_RegMask(uint idx) const {
740 // Fake the incoming arguments mask for blackholes: accept all registers
741 // and all stack slots. This would avoid any redundant register moves
742 // for blackhole inputs.
743 return RegMask::All;
744 }
745 #ifndef PRODUCT
746 virtual void format(PhaseRegAlloc* ra, outputStream* st) const;
747 #endif
748 };
749
750
751 #endif // SHARE_OPTO_CFGNODE_HPP