1 /*
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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5 * This code is free software; you can redistribute it and/or modify it
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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 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 public:
189 // Node layout (parallels RegionNode):
190 enum { Region, // Control input is the Phi's region.
191 Input // Input values are [1..len)
192 };
193
194 PhiNode( Node *r, const Type *t, const TypePtr* at = nullptr,
195 const int imid = -1,
196 const int iid = TypeOopPtr::InstanceTop,
197 const int iidx = Compile::AliasIdxTop,
198 const int ioffs = Type::OffsetTop )
199 : TypeNode(t,r->req()),
200 _adr_type(at),
201 _inst_mem_id(imid),
202 _inst_id(iid),
203 _inst_index(iidx),
204 _inst_offset(ioffs)
205 {
206 init_class_id(Class_Phi);
207 init_req(0, r);
208 verify_adr_type();
209 }
210 // create a new phi with in edges matching r and set (initially) to x
211 static PhiNode* make( Node* r, Node* x );
212 // extra type arguments override the new phi's bottom_type and adr_type
213 static PhiNode* make( Node* r, Node* x, const Type *t, const TypePtr* at = nullptr );
214 // create a new phi with narrowed memory type
215 PhiNode* slice_memory(const TypePtr* adr_type) const;
216 PhiNode* split_out_instance(const TypePtr* at, PhaseIterGVN *igvn) const;
217 // like make(r, x), but does not initialize the in edges to x
218 static PhiNode* make_blank( Node* r, Node* x );
219
220 // Accessors
221 RegionNode* region() const { Node* r = in(Region); assert(!r || r->is_Region(), ""); return (RegionNode*)r; }
222
223 bool is_tripcount(BasicType bt) const;
224
225 // Determine a unique non-trivial input, if any.
226 // Ignore casts if it helps. Return null on failure.
227 Node* unique_input(PhaseValues* phase, bool uncast);
228 Node* unique_input(PhaseValues* phase) {
229 Node* uin = unique_input(phase, false);
230 if (uin == nullptr) {
231 uin = unique_input(phase, true);
232 }
233 return uin;
234 }
235 Node* unique_input_recursive(PhaseGVN* phase);
236
237 // Check for a simple dead loop.
238 enum LoopSafety { Safe = 0, Unsafe, UnsafeLoop };
239 LoopSafety simple_data_loop_check(Node *in) const;
240 // Is it unsafe data loop? It becomes a dead loop if this phi node removed.
241 bool is_unsafe_data_reference(Node *in) const;
242 int is_diamond_phi() const;
243 bool try_clean_memory_phi(PhaseIterGVN* igvn);
244 virtual int Opcode() const;
245 virtual bool pinned() const { return in(0) != nullptr; }
246 virtual const TypePtr *adr_type() const { verify_adr_type(true); return _adr_type; }
247
248 void set_inst_mem_id(int inst_mem_id) { _inst_mem_id = inst_mem_id; }
249 int inst_mem_id() const { return _inst_mem_id; }
250 int inst_id() const { return _inst_id; }
251 int inst_index() const { return _inst_index; }
252 int inst_offset() const { return _inst_offset; }
253 bool is_same_inst_field(const Type* tp, int mem_id, int id, int index, int offset) {
254 return type()->basic_type() == tp->basic_type() &&
255 inst_mem_id() == mem_id &&
256 inst_id() == id &&
257 inst_index() == index &&
258 inst_offset() == offset &&
259 type()->higher_equal(tp);
260 }
261
262 bool can_be_inline_type() const {
263 return EnableValhalla && _type->isa_instptr() && _type->is_instptr()->can_be_inline_type();
264 }
265
266 Node* try_push_inline_types_down(PhaseGVN* phase, bool can_reshape);
267 DEBUG_ONLY(bool can_push_inline_types_down(PhaseGVN* phase);)
268
269 virtual const Type* Value(PhaseGVN* phase) const;
270 virtual Node* Identity(PhaseGVN* phase);
271 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
272 virtual const RegMask &out_RegMask() const;
273 virtual const RegMask &in_RegMask(uint) const;
274 #ifndef PRODUCT
275 virtual void dump_spec(outputStream *st) const;
276 #endif
277 #ifdef ASSERT
278 void verify_adr_type(VectorSet& visited, const TypePtr* at) const;
279 void verify_adr_type(bool recursive = false) const;
280 #else //ASSERT
281 void verify_adr_type(bool recursive = false) const {}
282 #endif //ASSERT
283
284 const TypeTuple* collect_types(PhaseGVN* phase) const;
285 };
286
287 //------------------------------GotoNode---------------------------------------
288 // GotoNodes perform direct branches.
289 class GotoNode : public Node {
290 public:
291 GotoNode( Node *control ) : Node(control) {}
292 virtual int Opcode() const;
293 virtual bool pinned() const { return true; }
294 virtual bool is_CFG() const { return true; }
295 virtual uint hash() const { return NO_HASH; } // CFG nodes do not hash
296 virtual const Node *is_block_proj() const { return this; }
297 virtual bool depends_only_on_test() const { return false; }
298 virtual const Type *bottom_type() const { return Type::CONTROL; }
299 virtual const Type* Value(PhaseGVN* phase) const;
300 virtual Node* Identity(PhaseGVN* phase);
301 virtual const RegMask &out_RegMask() const;
302 };
303
304 //------------------------------CProjNode--------------------------------------
305 // control projection for node that produces multiple control-flow paths
306 class CProjNode : public ProjNode {
307 public:
308 CProjNode( Node *ctrl, uint idx ) : ProjNode(ctrl,idx) {}
309 virtual int Opcode() const;
310 virtual bool is_CFG() const { return true; }
311 virtual uint hash() const { return NO_HASH; } // CFG nodes do not hash
312 virtual const Node *is_block_proj() const { return in(0); }
313 virtual const RegMask &out_RegMask() const;
314 virtual uint ideal_reg() const { return 0; }
315 };
316
317 //---------------------------MultiBranchNode-----------------------------------
318 // This class defines a MultiBranchNode, a MultiNode which yields multiple
319 // control values. These are distinguished from other types of MultiNodes
320 // which yield multiple values, but control is always and only projection #0.
321 class MultiBranchNode : public MultiNode {
322 public:
323 MultiBranchNode( uint required ) : MultiNode(required) {
324 init_class_id(Class_MultiBranch);
325 }
326 // returns required number of users to be well formed.
327 virtual int required_outcnt() const = 0;
328 };
329
330 //------------------------------IfNode-----------------------------------------
331 // Output selected Control, based on a boolean test
332 class IfNode : public MultiBranchNode {
333 public:
334 float _prob; // Probability of true path being taken.
335 float _fcnt; // Frequency counter
336
337 private:
338 AssertionPredicateType _assertion_predicate_type;
339
340 void init_node(Node* control, Node* bol) {
341 init_class_id(Class_If);
342 init_req(0, control);
343 init_req(1, bol);
344 }
345
346 // Size is bigger to hold the probability field. However, _prob does not
347 // change the semantics so it does not appear in the hash & cmp functions.
348 virtual uint size_of() const { return sizeof(*this); }
349
350 // Helper methods for fold_compares
351 bool cmpi_folds(PhaseIterGVN* igvn, bool fold_ne = false);
352 bool is_ctrl_folds(Node* ctrl, PhaseIterGVN* igvn);
353 bool has_shared_region(ProjNode* proj, ProjNode*& success, ProjNode*& fail);
354 bool has_only_uncommon_traps(ProjNode* proj, ProjNode*& success, ProjNode*& fail, PhaseIterGVN* igvn);
355 Node* merge_uncommon_traps(ProjNode* proj, ProjNode* success, ProjNode* fail, PhaseIterGVN* igvn);
356 static void improve_address_types(Node* l, Node* r, ProjNode* fail, PhaseIterGVN* igvn);
357 bool is_cmp_with_loadrange(ProjNode* proj);
358 bool is_null_check(ProjNode* proj, PhaseIterGVN* igvn);
359 bool is_side_effect_free_test(ProjNode* proj, PhaseIterGVN* igvn);
360 void reroute_side_effect_free_unc(ProjNode* proj, ProjNode* dom_proj, PhaseIterGVN* igvn);
361 bool fold_compares_helper(ProjNode* proj, ProjNode* success, ProjNode* fail, PhaseIterGVN* igvn);
362 static bool is_dominator_unc(CallStaticJavaNode* dom_unc, CallStaticJavaNode* unc);
363
364 protected:
365 ProjNode* range_check_trap_proj(int& flip, Node*& l, Node*& r);
366 Node* Ideal_common(PhaseGVN *phase, bool can_reshape);
367 Node* search_identical(int dist, PhaseIterGVN* igvn);
368
369 Node* simple_subsuming(PhaseIterGVN* igvn);
370
371 public:
372
373 // Degrees of branch prediction probability by order of magnitude:
374 // PROB_UNLIKELY_1e(N) is a 1 in 1eN chance.
375 // PROB_LIKELY_1e(N) is a 1 - PROB_UNLIKELY_1e(N)
376 #define PROB_UNLIKELY_MAG(N) (1e- ## N ## f)
377 #define PROB_LIKELY_MAG(N) (1.0f-PROB_UNLIKELY_MAG(N))
378
379 // Maximum and minimum branch prediction probabilties
380 // 1 in 1,000,000 (magnitude 6)
381 //
382 // Although PROB_NEVER == PROB_MIN and PROB_ALWAYS == PROB_MAX
383 // they are used to distinguish different situations:
384 //
385 // The name PROB_MAX (PROB_MIN) is for probabilities which correspond to
386 // very likely (unlikely) but with a concrete possibility of a rare
387 // contrary case. These constants would be used for pinning
388 // measurements, and as measures for assertions that have high
389 // confidence, but some evidence of occasional failure.
390 //
391 // The name PROB_ALWAYS (PROB_NEVER) is to stand for situations for which
392 // there is no evidence at all that the contrary case has ever occurred.
393
394 #define PROB_NEVER PROB_UNLIKELY_MAG(6)
395 #define PROB_ALWAYS PROB_LIKELY_MAG(6)
396
397 #define PROB_MIN PROB_UNLIKELY_MAG(6)
398 #define PROB_MAX PROB_LIKELY_MAG(6)
399
400 // Static branch prediction probabilities
401 // 1 in 10 (magnitude 1)
402 #define PROB_STATIC_INFREQUENT PROB_UNLIKELY_MAG(1)
403 #define PROB_STATIC_FREQUENT PROB_LIKELY_MAG(1)
404
405 // Fair probability 50/50
406 #define PROB_FAIR (0.5f)
407
408 // Unknown probability sentinel
409 #define PROB_UNKNOWN (-1.0f)
410
411 // Probability "constructors", to distinguish as a probability any manifest
412 // constant without a names
413 #define PROB_LIKELY(x) ((float) (x))
414 #define PROB_UNLIKELY(x) (1.0f - (float)(x))
415
416 // Other probabilities in use, but without a unique name, are documented
417 // here for lack of a better place:
418 //
419 // 1 in 1000 probabilities (magnitude 3):
420 // threshold for converting to conditional move
421 // likelihood of null check failure if a null HAS been seen before
422 // likelihood of slow path taken in library calls
423 //
424 // 1 in 10,000 probabilities (magnitude 4):
425 // threshold for making an uncommon trap probability more extreme
426 // threshold for for making a null check implicit
427 // likelihood of needing a gc if eden top moves during an allocation
428 // likelihood of a predicted call failure
429 //
430 // 1 in 100,000 probabilities (magnitude 5):
431 // threshold for ignoring counts when estimating path frequency
432 // likelihood of FP clipping failure
433 // likelihood of catching an exception from a try block
434 // likelihood of null check failure if a null has NOT been seen before
435 //
436 // Magic manifest probabilities such as 0.83, 0.7, ... can be found in
437 // gen_subtype_check() and catch_inline_exceptions().
438
439 IfNode(Node* control, Node* bol, float p, float fcnt);
440 IfNode(Node* control, Node* bol, float p, float fcnt, AssertionPredicateType assertion_predicate_type);
441
442 static IfNode* make_with_same_profile(IfNode* if_node_profile, Node* ctrl, Node* bol);
443
444 virtual int Opcode() const;
445 virtual bool pinned() const { return true; }
446 virtual const Type *bottom_type() const { return TypeTuple::IFBOTH; }
447 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
448 virtual const Type* Value(PhaseGVN* phase) const;
449 virtual int required_outcnt() const { return 2; }
450 virtual const RegMask &out_RegMask() const;
451 Node* fold_compares(PhaseIterGVN* phase);
452 static Node* up_one_dom(Node* curr, bool linear_only = false);
453 bool is_zero_trip_guard() const;
454 Node* dominated_by(Node* prev_dom, PhaseIterGVN* igvn, bool pin_array_access_nodes);
455 ProjNode* uncommon_trap_proj(CallStaticJavaNode*& call, Deoptimization::DeoptReason reason = Deoptimization::Reason_none) const;
456
457 // Takes the type of val and filters it through the test represented
458 // by if_proj and returns a more refined type if one is produced.
459 // Returns null is it couldn't improve the type.
460 static const TypeInt* filtered_int_type(PhaseGVN* phase, Node* val, Node* if_proj);
461
462 bool is_flat_array_check(PhaseTransform* phase, Node** array = nullptr);
463
464 AssertionPredicateType assertion_predicate_type() const {
465 return _assertion_predicate_type;
466 }
467
468 #ifndef PRODUCT
469 virtual void dump_spec(outputStream *st) const;
470 #endif
471
472 bool same_condition(const Node* dom, PhaseIterGVN* igvn) const;
473 };
474
475 class RangeCheckNode : public IfNode {
476 private:
477 int is_range_check(Node*& range, Node*& index, jint& offset);
478
479 public:
480 RangeCheckNode(Node* control, Node* bol, float p, float fcnt) : IfNode(control, bol, p, fcnt) {
481 init_class_id(Class_RangeCheck);
482 }
483
484 RangeCheckNode(Node* control, Node* bol, float p, float fcnt, AssertionPredicateType assertion_predicate_type)
485 : IfNode(control, bol, p, fcnt, assertion_predicate_type) {
486 init_class_id(Class_RangeCheck);
487 }
488
489 virtual int Opcode() const;
490 virtual Node* Ideal(PhaseGVN *phase, bool can_reshape);
491 };
492
493 // Special node that denotes a Parse Predicate added during parsing. A Parse Predicate serves as placeholder to later
494 // create Regular Predicates (Runtime Predicates with possible Assertion Predicates) above it. Together they form a
495 // Predicate Block. The Parse Predicate and Regular Predicates share the same uncommon trap.
496 // There are three kinds of Parse Predicates:
497 // Loop Parse Predicate, Profiled Loop Parse Predicate (both used by Loop Predication), and Loop Limit Check Parse
498 // Predicate (used for integer overflow checks when creating a counted loop).
499 // More information about predicates can be found in loopPredicate.cpp.
500 class ParsePredicateNode : public IfNode {
501 Deoptimization::DeoptReason _deopt_reason;
502
503 // When a Parse Predicate loses its connection to a loop head, it will be marked useless by
504 // EliminateUselessPredicates and cleaned up by Value(). It can also become useless when cloning it to both loops
505 // during Loop Multiversioning - we no longer use the old version.
506 PredicateState _predicate_state;
507 public:
508 ParsePredicateNode(Node* control, Deoptimization::DeoptReason deopt_reason, PhaseGVN* gvn);
509 virtual int Opcode() const;
510 virtual uint size_of() const { return sizeof(*this); }
511
512 Deoptimization::DeoptReason deopt_reason() const {
513 return _deopt_reason;
514 }
515
516 bool is_useless() const {
517 return _predicate_state == PredicateState::Useless;
518 }
519
520 void mark_useless(PhaseIterGVN& igvn);
521
522 void mark_maybe_useful() {
523 _predicate_state = PredicateState::MaybeUseful;
524 }
525
526 bool is_useful() const {
527 return _predicate_state == PredicateState::Useful;
528 }
529
530 void mark_useful() {
531 _predicate_state = PredicateState::Useful;
532 }
533
534 // Return the uncommon trap If projection of this Parse Predicate.
535 ParsePredicateUncommonProj* uncommon_proj() const {
536 return proj_out(0)->as_IfFalse();
537 }
538
539 Node* uncommon_trap() const;
540
541 Node* Ideal(PhaseGVN* phase, bool can_reshape) {
542 return nullptr; // Don't optimize
543 }
544
545 const Type* Value(PhaseGVN* phase) const;
546 NOT_PRODUCT(void dump_spec(outputStream* st) const;)
547 };
548
549 class IfProjNode : public CProjNode {
550 public:
551 IfProjNode(IfNode *ifnode, uint idx) : CProjNode(ifnode,idx) {}
552 virtual Node* Identity(PhaseGVN* phase);
553
554 void pin_array_access_nodes(PhaseIterGVN* igvn);
555
556 protected:
557 // Type of If input when this branch is always taken
558 virtual bool always_taken(const TypeTuple* t) const = 0;
559 };
560
561 class IfTrueNode : public IfProjNode {
562 public:
563 IfTrueNode( IfNode *ifnode ) : IfProjNode(ifnode,1) {
564 init_class_id(Class_IfTrue);
565 }
566 virtual int Opcode() const;
567
568 protected:
569 virtual bool always_taken(const TypeTuple* t) const { return t == TypeTuple::IFTRUE; }
570 };
571
572 class IfFalseNode : public IfProjNode {
573 public:
574 IfFalseNode( IfNode *ifnode ) : IfProjNode(ifnode,0) {
575 init_class_id(Class_IfFalse);
576 }
577 virtual int Opcode() const;
578
579 protected:
580 virtual bool always_taken(const TypeTuple* t) const { return t == TypeTuple::IFFALSE; }
581 };
582
583
584 //------------------------------PCTableNode------------------------------------
585 // Build an indirect branch table. Given a control and a table index,
586 // control is passed to the Projection matching the table index. Used to
587 // implement switch statements and exception-handling capabilities.
588 // Undefined behavior if passed-in index is not inside the table.
589 class PCTableNode : public MultiBranchNode {
590 virtual uint hash() const; // Target count; table size
591 virtual bool cmp( const Node &n ) const;
592 virtual uint size_of() const { return sizeof(*this); }
593
594 public:
595 const uint _size; // Number of targets
596
597 PCTableNode( Node *ctrl, Node *idx, uint size ) : MultiBranchNode(2), _size(size) {
598 init_class_id(Class_PCTable);
599 init_req(0, ctrl);
600 init_req(1, idx);
601 }
602 virtual int Opcode() const;
603 virtual const Type* Value(PhaseGVN* phase) const;
604 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
605 virtual const Type *bottom_type() const;
606 virtual bool pinned() const { return true; }
607 virtual int required_outcnt() const { return _size; }
608 };
609
610 //------------------------------JumpNode---------------------------------------
611 // Indirect branch. Uses PCTable above to implement a switch statement.
612 // It emits as a table load and local branch.
613 class JumpNode : public PCTableNode {
614 virtual uint size_of() const { return sizeof(*this); }
615 public:
616 float* _probs; // probability of each projection
617 float _fcnt; // total number of times this Jump was executed
618 JumpNode( Node* control, Node* switch_val, uint size, float* probs, float cnt)
619 : PCTableNode(control, switch_val, size),
620 _probs(probs), _fcnt(cnt) {
621 init_class_id(Class_Jump);
622 }
623 virtual int Opcode() const;
624 virtual const RegMask& out_RegMask() const;
625 virtual const Node* is_block_proj() const { return this; }
626 };
627
628 class JumpProjNode : public JProjNode {
629 virtual uint hash() const;
630 virtual bool cmp( const Node &n ) const;
631 virtual uint size_of() const { return sizeof(*this); }
632
633 private:
634 const int _dest_bci;
635 const uint _proj_no;
636 const int _switch_val;
637 public:
638 JumpProjNode(Node* jumpnode, uint proj_no, int dest_bci, int switch_val)
639 : JProjNode(jumpnode, proj_no), _dest_bci(dest_bci), _proj_no(proj_no), _switch_val(switch_val) {
640 init_class_id(Class_JumpProj);
641 }
642
643 virtual int Opcode() const;
644 virtual const Type* bottom_type() const { return Type::CONTROL; }
645 int dest_bci() const { return _dest_bci; }
646 int switch_val() const { return _switch_val; }
647 uint proj_no() const { return _proj_no; }
648 #ifndef PRODUCT
649 virtual void dump_spec(outputStream *st) const;
650 virtual void dump_compact_spec(outputStream *st) const;
651 #endif
652 };
653
654 //------------------------------CatchNode--------------------------------------
655 // Helper node to fork exceptions. "Catch" catches any exceptions thrown by
656 // a just-prior call. Looks like a PCTableNode but emits no code - just the
657 // table. The table lookup and branch is implemented by RethrowNode.
658 class CatchNode : public PCTableNode {
659 public:
660 CatchNode( Node *ctrl, Node *idx, uint size ) : PCTableNode(ctrl,idx,size){
661 init_class_id(Class_Catch);
662 }
663 virtual int Opcode() const;
664 virtual const Type* Value(PhaseGVN* phase) const;
665 };
666
667 // CatchProjNode controls which exception handler is targeted after a call.
668 // It is passed in the bci of the target handler, or no_handler_bci in case
669 // the projection doesn't lead to an exception handler.
670 class CatchProjNode : public CProjNode {
671 virtual uint hash() const;
672 virtual bool cmp( const Node &n ) const;
673 virtual uint size_of() const { return sizeof(*this); }
674
675 private:
676 const int _handler_bci;
677
678 public:
679 enum {
680 fall_through_index = 0, // the fall through projection index
681 catch_all_index = 1, // the projection index for catch-alls
682 no_handler_bci = -1 // the bci for fall through or catch-all projs
683 };
684
685 CatchProjNode(Node* catchnode, uint proj_no, int handler_bci)
686 : CProjNode(catchnode, proj_no), _handler_bci(handler_bci) {
687 init_class_id(Class_CatchProj);
688 assert(proj_no != fall_through_index || handler_bci < 0, "fall through case must have bci < 0");
689 }
690
691 virtual int Opcode() const;
692 virtual Node* Identity(PhaseGVN* phase);
693 virtual const Type *bottom_type() const { return Type::CONTROL; }
694 int handler_bci() const { return _handler_bci; }
695 bool is_handler_proj() const { return _handler_bci >= 0; }
696 #ifndef PRODUCT
697 virtual void dump_spec(outputStream *st) const;
698 #endif
699 };
700
701
702 //---------------------------------CreateExNode--------------------------------
703 // Helper node to create the exception coming back from a call
704 class CreateExNode : public TypeNode {
705 public:
706 CreateExNode(const Type* t, Node* control, Node* i_o) : TypeNode(t, 2) {
707 init_req(0, control);
708 init_req(1, i_o);
709 }
710 virtual int Opcode() const;
711 virtual Node* Identity(PhaseGVN* phase);
712 virtual bool pinned() const { return true; }
713 uint match_edge(uint idx) const { return 0; }
714 virtual uint ideal_reg() const { return Op_RegP; }
715 };
716
717 //------------------------------NeverBranchNode-------------------------------
718 // The never-taken branch. Used to give the appearance of exiting infinite
719 // loops to those algorithms that like all paths to be reachable. Encodes
720 // empty.
721 class NeverBranchNode : public MultiBranchNode {
722 public:
723 NeverBranchNode(Node* ctrl) : MultiBranchNode(1) {
724 init_req(0, ctrl);
725 init_class_id(Class_NeverBranch);
726 }
727 virtual int Opcode() const;
728 virtual bool pinned() const { return true; };
729 virtual const Type *bottom_type() const { return TypeTuple::IFBOTH; }
730 virtual const Type* Value(PhaseGVN* phase) const;
731 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
732 virtual int required_outcnt() const { return 2; }
733 virtual void emit(C2_MacroAssembler *masm, PhaseRegAlloc *ra_) const { }
734 virtual uint size(PhaseRegAlloc *ra_) const { return 0; }
735 #ifndef PRODUCT
736 virtual void format( PhaseRegAlloc *, outputStream *st ) const;
737 #endif
738 };
739
740 //------------------------------BlackholeNode----------------------------
741 // Blackhole all arguments. This node would survive through the compiler
742 // the effects on its arguments, and would be finally matched to nothing.
743 class BlackholeNode : public MultiNode {
744 public:
745 BlackholeNode(Node* ctrl) : MultiNode(1) {
746 init_req(TypeFunc::Control, ctrl);
747 init_class_id(Class_Blackhole);
748 }
749 virtual int Opcode() const;
750 virtual uint ideal_reg() const { return 0; } // not matched in the AD file
751 virtual const Type* bottom_type() const { return TypeTuple::MEMBAR; }
752 virtual Node* Ideal(PhaseGVN* phase, bool can_reshape);
753
754 const RegMask &in_RegMask(uint idx) const {
755 // Fake the incoming arguments mask for blackholes: accept all registers
756 // and all stack slots. This would avoid any redundant register moves
757 // for blackhole inputs.
758 return RegMask::All;
759 }
760 #ifndef PRODUCT
761 virtual void format(PhaseRegAlloc* ra, outputStream* st) const;
762 #endif
763 };
764
765
766 #endif // SHARE_OPTO_CFGNODE_HPP