1 /*
2 * Copyright (c) 1997, 2023, 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 *
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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).
14 *
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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/type.hpp"
32
33 // Portions of code courtesy of Clifford Click
34
35 // Optimization - Graph Style
36
37 class Matcher;
38 class Node;
39 class RegionNode;
40 class TypeNode;
41 class PhiNode;
42 class GotoNode;
43 class MultiNode;
44 class MultiBranchNode;
45 class IfNode;
46 class PCTableNode;
47 class JumpNode;
48 class CatchNode;
49 class NeverBranchNode;
50 class BlackholeNode;
51 class ProjNode;
52 class CProjNode;
53 class IfTrueNode;
54 class IfFalseNode;
55 class CatchProjNode;
56 class JProjNode;
57 class JumpProjNode;
58 class SCMemProjNode;
59 class PhaseIdealLoop;
60
61 // The success projection of a Parse Predicate is always an IfTrueNode and the uncommon projection an IfFalseNode
62 typedef IfTrueNode ParsePredicateSuccessProj;
63 typedef IfFalseNode ParsePredicateUncommonProj;
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 PhaseGVN* phase) 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 DEBUG_ONLY(void verify_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 bool depends_only_on_test() const { return false; }
129 virtual const Type* bottom_type() const { return Type::CONTROL; }
130 virtual const Type* Value(PhaseGVN* phase) const;
131 virtual Node* Identity(PhaseGVN* phase);
132 virtual Node* Ideal(PhaseGVN* phase, bool can_reshape);
133 void remove_unreachable_subgraph(PhaseIterGVN* igvn);
134 virtual const RegMask &out_RegMask() const;
135 bool optimize_trichotomy(PhaseIterGVN* igvn);
136 NOT_PRODUCT(virtual void dump_spec(outputStream* st) const;)
137 };
138
139 //------------------------------JProjNode--------------------------------------
140 // jump projection for node that produces multiple control-flow paths
141 class JProjNode : public ProjNode {
142 public:
143 JProjNode( Node* ctrl, uint idx ) : ProjNode(ctrl,idx) {}
144 virtual int Opcode() const;
145 virtual bool is_CFG() const { return true; }
146 virtual uint hash() const { return NO_HASH; } // CFG nodes do not hash
147 virtual const Node* is_block_proj() const { return in(0); }
148 virtual const RegMask& out_RegMask() const;
149 virtual uint ideal_reg() const { return 0; }
150 };
151
152 //------------------------------PhiNode----------------------------------------
153 // PhiNodes merge values from different Control paths. Slot 0 points to the
154 // controlling RegionNode. Other slots map 1-for-1 with incoming control flow
155 // paths to the RegionNode.
156 class PhiNode : public TypeNode {
157 friend class PhaseRenumberLive;
158
159 const TypePtr* const _adr_type; // non-null only for Type::MEMORY nodes.
160 // The following fields are only used for data PhiNodes to indicate
161 // that the PhiNode represents the value of a known instance field.
162 int _inst_mem_id; // Instance memory id (node index of the memory Phi)
163 int _inst_id; // Instance id of the memory slice.
164 const int _inst_index; // Alias index of the instance memory slice.
165 // Array elements references have the same alias_idx but different offset.
166 const int _inst_offset; // Offset of the instance memory slice.
167 // Size is bigger to hold the _adr_type field.
168 virtual uint hash() const; // Check the type
169 virtual bool cmp( const Node &n ) const;
170 virtual uint size_of() const { return sizeof(*this); }
171
172 // Determine if CMoveNode::is_cmove_id can be used at this join point.
173 Node* is_cmove_id(PhaseTransform* phase, int true_path);
174 bool wait_for_region_igvn(PhaseGVN* phase);
175 bool is_data_loop(RegionNode* r, Node* uin, const PhaseGVN* phase);
176
177 static Node* clone_through_phi(Node* root_phi, const Type* t, uint c, PhaseIterGVN* igvn);
178 static Node* merge_through_phi(Node* root_phi, PhaseIterGVN* igvn);
179
180 bool must_wait_for_region_in_irreducible_loop(PhaseGVN* phase) const;
181
182 public:
183 // Node layout (parallels RegionNode):
184 enum { Region, // Control input is the Phi's region.
185 Input // Input values are [1..len)
186 };
187
188 PhiNode( Node *r, const Type *t, const TypePtr* at = nullptr,
189 const int imid = -1,
190 const int iid = TypeOopPtr::InstanceTop,
191 const int iidx = Compile::AliasIdxTop,
192 const int ioffs = Type::OffsetTop )
193 : TypeNode(t,r->req()),
194 _adr_type(at),
195 _inst_mem_id(imid),
196 _inst_id(iid),
197 _inst_index(iidx),
198 _inst_offset(ioffs)
199 {
200 init_class_id(Class_Phi);
201 init_req(0, r);
202 verify_adr_type();
203 }
204 // create a new phi with in edges matching r and set (initially) to x
205 static PhiNode* make( Node* r, Node* x );
206 // extra type arguments override the new phi's bottom_type and adr_type
207 static PhiNode* make( Node* r, Node* x, const Type *t, const TypePtr* at = nullptr );
208 // create a new phi with narrowed memory type
209 PhiNode* slice_memory(const TypePtr* adr_type) const;
210 PhiNode* split_out_instance(const TypePtr* at, PhaseIterGVN *igvn) const;
211 // like make(r, x), but does not initialize the in edges to x
212 static PhiNode* make_blank( Node* r, Node* x );
213
214 // Accessors
215 RegionNode* region() const { Node* r = in(Region); assert(!r || r->is_Region(), ""); return (RegionNode*)r; }
216
217 bool is_tripcount(BasicType bt) const;
218
219 // Determine a unique non-trivial input, if any.
220 // Ignore casts if it helps. Return null on failure.
221 Node* unique_input(PhaseTransform *phase, bool uncast);
222 Node* unique_input(PhaseTransform *phase) {
223 Node* uin = unique_input(phase, false);
224 if (uin == nullptr) {
225 uin = unique_input(phase, true);
226 }
227 return uin;
228 }
229
230 // Check for a simple dead loop.
231 enum LoopSafety { Safe = 0, Unsafe, UnsafeLoop };
232 LoopSafety simple_data_loop_check(Node *in) const;
233 // Is it unsafe data loop? It becomes a dead loop if this phi node removed.
234 bool is_unsafe_data_reference(Node *in) const;
235 int is_diamond_phi(bool check_control_only = false) const;
236 virtual int Opcode() const;
237 virtual bool pinned() const { return in(0) != 0; }
238 virtual const TypePtr *adr_type() const { verify_adr_type(true); return _adr_type; }
239
240 void set_inst_mem_id(int inst_mem_id) { _inst_mem_id = inst_mem_id; }
241 const int inst_mem_id() const { return _inst_mem_id; }
242 const int inst_id() const { return _inst_id; }
243 const int inst_index() const { return _inst_index; }
244 const int inst_offset() const { return _inst_offset; }
245 bool is_same_inst_field(const Type* tp, int mem_id, int id, int index, int offset) {
246 return type()->basic_type() == tp->basic_type() &&
247 inst_mem_id() == mem_id &&
248 inst_id() == id &&
249 inst_index() == index &&
250 inst_offset() == offset &&
251 type()->higher_equal(tp);
252 }
253 Node* try_clean_mem_phi(PhaseGVN *phase);
254
255 InlineTypeNode* push_inline_types_through(PhaseGVN* phase, bool can_reshape, ciInlineKlass* vk, bool is_init);
256
257 virtual const Type* Value(PhaseGVN* phase) const;
258 virtual Node* Identity(PhaseGVN* phase);
259 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
260 virtual const RegMask &out_RegMask() const;
261 virtual const RegMask &in_RegMask(uint) const;
262 #ifndef PRODUCT
263 virtual void dump_spec(outputStream *st) const;
264 #endif
265 #ifdef ASSERT
266 void verify_adr_type(VectorSet& visited, const TypePtr* at) const;
267 void verify_adr_type(bool recursive = false) const;
268 #else //ASSERT
269 void verify_adr_type(bool recursive = false) const {}
270 #endif //ASSERT
271 };
272
273 //------------------------------GotoNode---------------------------------------
274 // GotoNodes perform direct branches.
275 class GotoNode : public Node {
276 public:
277 GotoNode( Node *control ) : Node(control) {}
278 virtual int Opcode() const;
279 virtual bool pinned() const { return true; }
280 virtual bool is_CFG() const { return true; }
281 virtual uint hash() const { return NO_HASH; } // CFG nodes do not hash
282 virtual const Node *is_block_proj() const { return this; }
283 virtual bool depends_only_on_test() const { return false; }
284 virtual const Type *bottom_type() const { return Type::CONTROL; }
285 virtual const Type* Value(PhaseGVN* phase) const;
286 virtual Node* Identity(PhaseGVN* phase);
287 virtual const RegMask &out_RegMask() const;
288 };
289
290 //------------------------------CProjNode--------------------------------------
291 // control projection for node that produces multiple control-flow paths
292 class CProjNode : public ProjNode {
293 public:
294 CProjNode( Node *ctrl, uint idx ) : ProjNode(ctrl,idx) {}
295 virtual int Opcode() const;
296 virtual bool is_CFG() const { return true; }
297 virtual uint hash() const { return NO_HASH; } // CFG nodes do not hash
298 virtual const Node *is_block_proj() const { return in(0); }
299 virtual const RegMask &out_RegMask() const;
300 virtual uint ideal_reg() const { return 0; }
301 };
302
303 //---------------------------MultiBranchNode-----------------------------------
304 // This class defines a MultiBranchNode, a MultiNode which yields multiple
305 // control values. These are distinguished from other types of MultiNodes
306 // which yield multiple values, but control is always and only projection #0.
307 class MultiBranchNode : public MultiNode {
308 public:
309 MultiBranchNode( uint required ) : MultiNode(required) {
310 init_class_id(Class_MultiBranch);
311 }
312 // returns required number of users to be well formed.
313 virtual int required_outcnt() const = 0;
314 };
315
316 //------------------------------IfNode-----------------------------------------
317 // Output selected Control, based on a boolean test
318 class IfNode : public MultiBranchNode {
319 // Size is bigger to hold the probability field. However, _prob does not
320 // change the semantics so it does not appear in the hash & cmp functions.
321 virtual uint size_of() const { return sizeof(*this); }
322
323 private:
324 // Helper methods for fold_compares
325 bool cmpi_folds(PhaseIterGVN* igvn, bool fold_ne = false);
326 bool is_ctrl_folds(Node* ctrl, PhaseIterGVN* igvn);
327 bool has_shared_region(ProjNode* proj, ProjNode*& success, ProjNode*& fail);
328 bool has_only_uncommon_traps(ProjNode* proj, ProjNode*& success, ProjNode*& fail, PhaseIterGVN* igvn);
329 Node* merge_uncommon_traps(ProjNode* proj, ProjNode* success, ProjNode* fail, PhaseIterGVN* igvn);
330 static void improve_address_types(Node* l, Node* r, ProjNode* fail, PhaseIterGVN* igvn);
331 bool is_cmp_with_loadrange(ProjNode* proj);
332 bool is_null_check(ProjNode* proj, PhaseIterGVN* igvn);
333 bool is_side_effect_free_test(ProjNode* proj, PhaseIterGVN* igvn);
334 void reroute_side_effect_free_unc(ProjNode* proj, ProjNode* dom_proj, PhaseIterGVN* igvn);
335 ProjNode* uncommon_trap_proj(CallStaticJavaNode*& call) const;
336 bool fold_compares_helper(ProjNode* proj, ProjNode* success, ProjNode* fail, PhaseIterGVN* igvn);
337 static bool is_dominator_unc(CallStaticJavaNode* dom_unc, CallStaticJavaNode* unc);
338
339 protected:
340 ProjNode* range_check_trap_proj(int& flip, Node*& l, Node*& r);
341 Node* Ideal_common(PhaseGVN *phase, bool can_reshape);
342 Node* search_identical(int dist);
343
344 Node* simple_subsuming(PhaseIterGVN* igvn);
345
346 public:
347
348 // Degrees of branch prediction probability by order of magnitude:
349 // PROB_UNLIKELY_1e(N) is a 1 in 1eN chance.
350 // PROB_LIKELY_1e(N) is a 1 - PROB_UNLIKELY_1e(N)
351 #define PROB_UNLIKELY_MAG(N) (1e- ## N ## f)
352 #define PROB_LIKELY_MAG(N) (1.0f-PROB_UNLIKELY_MAG(N))
353
354 // Maximum and minimum branch prediction probabilties
355 // 1 in 1,000,000 (magnitude 6)
356 //
357 // Although PROB_NEVER == PROB_MIN and PROB_ALWAYS == PROB_MAX
358 // they are used to distinguish different situations:
359 //
360 // The name PROB_MAX (PROB_MIN) is for probabilities which correspond to
361 // very likely (unlikely) but with a concrete possibility of a rare
362 // contrary case. These constants would be used for pinning
363 // measurements, and as measures for assertions that have high
364 // confidence, but some evidence of occasional failure.
365 //
366 // The name PROB_ALWAYS (PROB_NEVER) is to stand for situations for which
367 // there is no evidence at all that the contrary case has ever occurred.
368
369 #define PROB_NEVER PROB_UNLIKELY_MAG(6)
370 #define PROB_ALWAYS PROB_LIKELY_MAG(6)
371
372 #define PROB_MIN PROB_UNLIKELY_MAG(6)
373 #define PROB_MAX PROB_LIKELY_MAG(6)
374
375 // Static branch prediction probabilities
376 // 1 in 10 (magnitude 1)
377 #define PROB_STATIC_INFREQUENT PROB_UNLIKELY_MAG(1)
378 #define PROB_STATIC_FREQUENT PROB_LIKELY_MAG(1)
379
380 // Fair probability 50/50
381 #define PROB_FAIR (0.5f)
382
383 // Unknown probability sentinel
384 #define PROB_UNKNOWN (-1.0f)
385
386 // Probability "constructors", to distinguish as a probability any manifest
387 // constant without a names
388 #define PROB_LIKELY(x) ((float) (x))
389 #define PROB_UNLIKELY(x) (1.0f - (float)(x))
390
391 // Other probabilities in use, but without a unique name, are documented
392 // here for lack of a better place:
393 //
394 // 1 in 1000 probabilities (magnitude 3):
395 // threshold for converting to conditional move
396 // likelihood of null check failure if a null HAS been seen before
397 // likelihood of slow path taken in library calls
398 //
399 // 1 in 10,000 probabilities (magnitude 4):
400 // threshold for making an uncommon trap probability more extreme
401 // threshold for for making a null check implicit
402 // likelihood of needing a gc if eden top moves during an allocation
403 // likelihood of a predicted call failure
404 //
405 // 1 in 100,000 probabilities (magnitude 5):
406 // threshold for ignoring counts when estimating path frequency
407 // likelihood of FP clipping failure
408 // likelihood of catching an exception from a try block
409 // likelihood of null check failure if a null has NOT been seen before
410 //
411 // Magic manifest probabilities such as 0.83, 0.7, ... can be found in
412 // gen_subtype_check() and catch_inline_exceptions().
413
414 float _prob; // Probability of true path being taken.
415 float _fcnt; // Frequency counter
416 IfNode( Node *control, Node *b, float p, float fcnt )
417 : MultiBranchNode(2), _prob(p), _fcnt(fcnt) {
418 init_class_id(Class_If);
419 init_req(0,control);
420 init_req(1,b);
421 }
422 virtual int Opcode() const;
423 virtual bool pinned() const { return true; }
424 virtual const Type *bottom_type() const { return TypeTuple::IFBOTH; }
425 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
426 virtual const Type* Value(PhaseGVN* phase) const;
427 virtual int required_outcnt() const { return 2; }
428 virtual const RegMask &out_RegMask() const;
429 Node* fold_compares(PhaseIterGVN* phase);
430 static Node* up_one_dom(Node* curr, bool linear_only = false);
431 Node* dominated_by(Node* prev_dom, PhaseIterGVN* igvn);
432
433 // Takes the type of val and filters it through the test represented
434 // by if_proj and returns a more refined type if one is produced.
435 // Returns null is it couldn't improve the type.
436 static const TypeInt* filtered_int_type(PhaseGVN* phase, Node* val, Node* if_proj);
437
438 bool is_flat_array_check(PhaseTransform* phase, Node** array = NULL);
439
440 #ifndef PRODUCT
441 virtual void dump_spec(outputStream *st) const;
442 #endif
443 };
444
445 class RangeCheckNode : public IfNode {
446 private:
447 int is_range_check(Node* &range, Node* &index, jint &offset);
448
449 public:
450 RangeCheckNode(Node* control, Node *b, float p, float fcnt)
451 : IfNode(control, b, p, fcnt) {
452 init_class_id(Class_RangeCheck);
453 }
454
455 virtual int Opcode() const;
456 virtual Node* Ideal(PhaseGVN *phase, bool can_reshape);
457 };
458
459 class IfProjNode : public CProjNode {
460 public:
461 IfProjNode(IfNode *ifnode, uint idx) : CProjNode(ifnode,idx) {}
462 virtual Node* Identity(PhaseGVN* phase);
463
464 protected:
465 // Type of If input when this branch is always taken
466 virtual bool always_taken(const TypeTuple* t) const = 0;
467 };
468
469 class IfTrueNode : public IfProjNode {
470 public:
471 IfTrueNode( IfNode *ifnode ) : IfProjNode(ifnode,1) {
472 init_class_id(Class_IfTrue);
473 }
474 virtual int Opcode() const;
475
476 protected:
477 virtual bool always_taken(const TypeTuple* t) const { return t == TypeTuple::IFTRUE; }
478 };
479
480 class IfFalseNode : public IfProjNode {
481 public:
482 IfFalseNode( IfNode *ifnode ) : IfProjNode(ifnode,0) {
483 init_class_id(Class_IfFalse);
484 }
485 virtual int Opcode() const;
486
487 protected:
488 virtual bool always_taken(const TypeTuple* t) const { return t == TypeTuple::IFFALSE; }
489 };
490
491
492 //------------------------------PCTableNode------------------------------------
493 // Build an indirect branch table. Given a control and a table index,
494 // control is passed to the Projection matching the table index. Used to
495 // implement switch statements and exception-handling capabilities.
496 // Undefined behavior if passed-in index is not inside the table.
497 class PCTableNode : public MultiBranchNode {
498 virtual uint hash() const; // Target count; table size
499 virtual bool cmp( const Node &n ) const;
500 virtual uint size_of() const { return sizeof(*this); }
501
502 public:
503 const uint _size; // Number of targets
504
505 PCTableNode( Node *ctrl, Node *idx, uint size ) : MultiBranchNode(2), _size(size) {
506 init_class_id(Class_PCTable);
507 init_req(0, ctrl);
508 init_req(1, idx);
509 }
510 virtual int Opcode() const;
511 virtual const Type* Value(PhaseGVN* phase) const;
512 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
513 virtual const Type *bottom_type() const;
514 virtual bool pinned() const { return true; }
515 virtual int required_outcnt() const { return _size; }
516 };
517
518 //------------------------------JumpNode---------------------------------------
519 // Indirect branch. Uses PCTable above to implement a switch statement.
520 // It emits as a table load and local branch.
521 class JumpNode : public PCTableNode {
522 virtual uint size_of() const { return sizeof(*this); }
523 public:
524 float* _probs; // probability of each projection
525 float _fcnt; // total number of times this Jump was executed
526 JumpNode( Node* control, Node* switch_val, uint size, float* probs, float cnt)
527 : PCTableNode(control, switch_val, size),
528 _probs(probs), _fcnt(cnt) {
529 init_class_id(Class_Jump);
530 }
531 virtual int Opcode() const;
532 virtual const RegMask& out_RegMask() const;
533 virtual const Node* is_block_proj() const { return this; }
534 };
535
536 class JumpProjNode : public JProjNode {
537 virtual uint hash() const;
538 virtual bool cmp( const Node &n ) const;
539 virtual uint size_of() const { return sizeof(*this); }
540
541 private:
542 const int _dest_bci;
543 const uint _proj_no;
544 const int _switch_val;
545 public:
546 JumpProjNode(Node* jumpnode, uint proj_no, int dest_bci, int switch_val)
547 : JProjNode(jumpnode, proj_no), _dest_bci(dest_bci), _proj_no(proj_no), _switch_val(switch_val) {
548 init_class_id(Class_JumpProj);
549 }
550
551 virtual int Opcode() const;
552 virtual const Type* bottom_type() const { return Type::CONTROL; }
553 int dest_bci() const { return _dest_bci; }
554 int switch_val() const { return _switch_val; }
555 uint proj_no() const { return _proj_no; }
556 #ifndef PRODUCT
557 virtual void dump_spec(outputStream *st) const;
558 virtual void dump_compact_spec(outputStream *st) const;
559 #endif
560 };
561
562 //------------------------------CatchNode--------------------------------------
563 // Helper node to fork exceptions. "Catch" catches any exceptions thrown by
564 // a just-prior call. Looks like a PCTableNode but emits no code - just the
565 // table. The table lookup and branch is implemented by RethrowNode.
566 class CatchNode : public PCTableNode {
567 public:
568 CatchNode( Node *ctrl, Node *idx, uint size ) : PCTableNode(ctrl,idx,size){
569 init_class_id(Class_Catch);
570 }
571 virtual int Opcode() const;
572 virtual const Type* Value(PhaseGVN* phase) const;
573 };
574
575 // CatchProjNode controls which exception handler is targeted after a call.
576 // It is passed in the bci of the target handler, or no_handler_bci in case
577 // the projection doesn't lead to an exception handler.
578 class CatchProjNode : public CProjNode {
579 virtual uint hash() const;
580 virtual bool cmp( const Node &n ) const;
581 virtual uint size_of() const { return sizeof(*this); }
582
583 private:
584 const int _handler_bci;
585
586 public:
587 enum {
588 fall_through_index = 0, // the fall through projection index
589 catch_all_index = 1, // the projection index for catch-alls
590 no_handler_bci = -1 // the bci for fall through or catch-all projs
591 };
592
593 CatchProjNode(Node* catchnode, uint proj_no, int handler_bci)
594 : CProjNode(catchnode, proj_no), _handler_bci(handler_bci) {
595 init_class_id(Class_CatchProj);
596 assert(proj_no != fall_through_index || handler_bci < 0, "fall through case must have bci < 0");
597 }
598
599 virtual int Opcode() const;
600 virtual Node* Identity(PhaseGVN* phase);
601 virtual const Type *bottom_type() const { return Type::CONTROL; }
602 int handler_bci() const { return _handler_bci; }
603 bool is_handler_proj() const { return _handler_bci >= 0; }
604 #ifndef PRODUCT
605 virtual void dump_spec(outputStream *st) const;
606 #endif
607 };
608
609
610 //---------------------------------CreateExNode--------------------------------
611 // Helper node to create the exception coming back from a call
612 class CreateExNode : public TypeNode {
613 public:
614 CreateExNode(const Type* t, Node* control, Node* i_o) : TypeNode(t, 2) {
615 init_req(0, control);
616 init_req(1, i_o);
617 }
618 virtual int Opcode() const;
619 virtual Node* Identity(PhaseGVN* phase);
620 virtual bool pinned() const { return true; }
621 uint match_edge(uint idx) const { return 0; }
622 virtual uint ideal_reg() const { return Op_RegP; }
623 };
624
625 //------------------------------NeverBranchNode-------------------------------
626 // The never-taken branch. Used to give the appearance of exiting infinite
627 // loops to those algorithms that like all paths to be reachable. Encodes
628 // empty.
629 class NeverBranchNode : public MultiBranchNode {
630 public:
631 NeverBranchNode(Node* ctrl) : MultiBranchNode(1) {
632 init_req(0, ctrl);
633 init_class_id(Class_NeverBranch);
634 }
635 virtual int Opcode() const;
636 virtual bool pinned() const { return true; };
637 virtual const Type *bottom_type() const { return TypeTuple::IFBOTH; }
638 virtual const Type* Value(PhaseGVN* phase) const;
639 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
640 virtual int required_outcnt() const { return 2; }
641 virtual void emit(CodeBuffer &cbuf, PhaseRegAlloc *ra_) const { }
642 virtual uint size(PhaseRegAlloc *ra_) const { return 0; }
643 #ifndef PRODUCT
644 virtual void format( PhaseRegAlloc *, outputStream *st ) const;
645 #endif
646 };
647
648 //------------------------------BlackholeNode----------------------------
649 // Blackhole all arguments. This node would survive through the compiler
650 // the effects on its arguments, and would be finally matched to nothing.
651 class BlackholeNode : public MultiNode {
652 public:
653 BlackholeNode(Node* ctrl) : MultiNode(1) {
654 init_req(TypeFunc::Control, ctrl);
655 init_class_id(Class_Blackhole);
656 }
657 virtual int Opcode() const;
658 virtual uint ideal_reg() const { return 0; } // not matched in the AD file
659 virtual const Type* bottom_type() const { return TypeTuple::MEMBAR; }
660
661 const RegMask &in_RegMask(uint idx) const {
662 // Fake the incoming arguments mask for blackholes: accept all registers
663 // and all stack slots. This would avoid any redundant register moves
664 // for blackhole inputs.
665 return RegMask::All;
666 }
667 #ifndef PRODUCT
668 virtual void format(PhaseRegAlloc* ra, outputStream* st) const;
669 #endif
670 };
671
672
673 #endif // SHARE_OPTO_CFGNODE_HPP