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 *
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).
14 *
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16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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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 is_diamond() const;
136 void try_clean_mem_phis(PhaseIterGVN* phase);
137 bool optimize_trichotomy(PhaseIterGVN* igvn);
138 NOT_PRODUCT(virtual void dump_spec(outputStream* st) const;)
139 };
140
141 //------------------------------JProjNode--------------------------------------
142 // jump projection for node that produces multiple control-flow paths
143 class JProjNode : public ProjNode {
144 public:
145 JProjNode( Node* ctrl, uint idx ) : ProjNode(ctrl,idx) {}
146 virtual int Opcode() const;
147 virtual bool is_CFG() const { return true; }
148 virtual uint hash() const { return NO_HASH; } // CFG nodes do not hash
149 virtual const Node* is_block_proj() const { return in(0); }
150 virtual const RegMask& out_RegMask() const;
151 virtual uint ideal_reg() const { return 0; }
152 };
153
154 //------------------------------PhiNode----------------------------------------
155 // PhiNodes merge values from different Control paths. Slot 0 points to the
156 // controlling RegionNode. Other slots map 1-for-1 with incoming control flow
157 // paths to the RegionNode.
158 class PhiNode : public TypeNode {
159 friend class PhaseRenumberLive;
160
161 const TypePtr* const _adr_type; // non-null only for Type::MEMORY nodes.
162 // The following fields are only used for data PhiNodes to indicate
163 // that the PhiNode represents the value of a known instance field.
164 int _inst_mem_id; // Instance memory id (node index of the memory Phi)
165 int _inst_id; // Instance id of the memory slice.
166 const int _inst_index; // Alias index of the instance memory slice.
167 // Array elements references have the same alias_idx but different offset.
168 const int _inst_offset; // Offset of the instance memory slice.
169 // Size is bigger to hold the _adr_type field.
170 virtual uint hash() const; // Check the type
171 virtual bool cmp( const Node &n ) const;
172 virtual uint size_of() const { return sizeof(*this); }
173
174 // Determine if CMoveNode::is_cmove_id can be used at this join point.
175 Node* is_cmove_id(PhaseTransform* phase, int true_path);
176 bool wait_for_region_igvn(PhaseGVN* phase);
177 bool is_data_loop(RegionNode* r, Node* uin, const PhaseGVN* phase);
178
179 static Node* clone_through_phi(Node* root_phi, const Type* t, uint c, PhaseIterGVN* igvn);
180 static Node* merge_through_phi(Node* root_phi, PhaseIterGVN* igvn);
181
182 bool must_wait_for_region_in_irreducible_loop(PhaseGVN* phase) const;
183
184 bool can_push_inline_types_down(PhaseGVN* phase, bool can_reshape, ciInlineKlass*& inline_klass);
185 InlineTypeNode* push_inline_types_down(PhaseGVN* phase, bool can_reshape, ciInlineKlass* inline_klass);
186
187 public:
188 // Node layout (parallels RegionNode):
189 enum { Region, // Control input is the Phi's region.
190 Input // Input values are [1..len)
191 };
192
193 PhiNode( Node *r, const Type *t, const TypePtr* at = nullptr,
194 const int imid = -1,
195 const int iid = TypeOopPtr::InstanceTop,
196 const int iidx = Compile::AliasIdxTop,
197 const int ioffs = Type::OffsetTop )
198 : TypeNode(t,r->req()),
199 _adr_type(at),
200 _inst_mem_id(imid),
201 _inst_id(iid),
202 _inst_index(iidx),
203 _inst_offset(ioffs)
204 {
205 init_class_id(Class_Phi);
206 init_req(0, r);
207 verify_adr_type();
208 }
209 // create a new phi with in edges matching r and set (initially) to x
210 static PhiNode* make( Node* r, Node* x );
211 // extra type arguments override the new phi's bottom_type and adr_type
212 static PhiNode* make( Node* r, Node* x, const Type *t, const TypePtr* at = nullptr );
213 // create a new phi with narrowed memory type
214 PhiNode* slice_memory(const TypePtr* adr_type) const;
215 PhiNode* split_out_instance(const TypePtr* at, PhaseIterGVN *igvn) const;
216 // like make(r, x), but does not initialize the in edges to x
217 static PhiNode* make_blank( Node* r, Node* x );
218
219 // Accessors
220 RegionNode* region() const { Node* r = in(Region); assert(!r || r->is_Region(), ""); return (RegionNode*)r; }
221
222 bool is_tripcount(BasicType bt) const;
223
224 // Determine a unique non-trivial input, if any.
225 // Ignore casts if it helps. Return null on failure.
226 Node* unique_input(PhaseValues* phase, bool uncast);
227 Node* unique_input(PhaseValues* phase) {
228 Node* uin = unique_input(phase, false);
229 if (uin == nullptr) {
230 uin = unique_input(phase, true);
231 }
232 return uin;
233 }
234
235 // Check for a simple dead loop.
236 enum LoopSafety { Safe = 0, Unsafe, UnsafeLoop };
237 LoopSafety simple_data_loop_check(Node *in) const;
238 // Is it unsafe data loop? It becomes a dead loop if this phi node removed.
239 bool is_unsafe_data_reference(Node *in) const;
240 int is_diamond_phi() const;
241 bool try_clean_memory_phi(PhaseIterGVN* igvn);
242 virtual int Opcode() const;
243 virtual bool pinned() const { return in(0) != 0; }
244 virtual const TypePtr *adr_type() const { verify_adr_type(true); return _adr_type; }
245
246 void set_inst_mem_id(int inst_mem_id) { _inst_mem_id = inst_mem_id; }
247 int inst_mem_id() const { return _inst_mem_id; }
248 int inst_id() const { return _inst_id; }
249 int inst_index() const { return _inst_index; }
250 int inst_offset() const { return _inst_offset; }
251 bool is_same_inst_field(const Type* tp, int mem_id, int id, int index, int offset) {
252 return type()->basic_type() == tp->basic_type() &&
253 inst_mem_id() == mem_id &&
254 inst_id() == id &&
255 inst_index() == index &&
256 inst_offset() == offset &&
257 type()->higher_equal(tp);
258 }
259
260 bool can_be_inline_type() const {
261 return EnableValhalla && _type->isa_instptr() && _type->is_instptr()->can_be_inline_type();
262 }
263
264 Node* try_push_inline_types_down(PhaseGVN* phase, bool can_reshape);
265
266 virtual const Type* Value(PhaseGVN* phase) const;
267 virtual Node* Identity(PhaseGVN* phase);
268 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
269 virtual const RegMask &out_RegMask() const;
270 virtual const RegMask &in_RegMask(uint) const;
271 #ifndef PRODUCT
272 virtual void dump_spec(outputStream *st) const;
273 #endif
274 #ifdef ASSERT
275 void verify_adr_type(VectorSet& visited, const TypePtr* at) const;
276 void verify_adr_type(bool recursive = false) const;
277 #else //ASSERT
278 void verify_adr_type(bool recursive = false) const {}
279 #endif //ASSERT
280
281 const TypeTuple* collect_types(PhaseGVN* phase) const;
282 };
283
284 //------------------------------GotoNode---------------------------------------
285 // GotoNodes perform direct branches.
286 class GotoNode : public Node {
287 public:
288 GotoNode( Node *control ) : Node(control) {}
289 virtual int Opcode() const;
290 virtual bool pinned() const { return true; }
291 virtual bool is_CFG() const { return true; }
292 virtual uint hash() const { return NO_HASH; } // CFG nodes do not hash
293 virtual const Node *is_block_proj() const { return this; }
294 virtual bool depends_only_on_test() const { return false; }
295 virtual const Type *bottom_type() const { return Type::CONTROL; }
296 virtual const Type* Value(PhaseGVN* phase) const;
297 virtual Node* Identity(PhaseGVN* phase);
298 virtual const RegMask &out_RegMask() const;
299 };
300
301 //------------------------------CProjNode--------------------------------------
302 // control projection for node that produces multiple control-flow paths
303 class CProjNode : public ProjNode {
304 public:
305 CProjNode( Node *ctrl, uint idx ) : ProjNode(ctrl,idx) {}
306 virtual int Opcode() const;
307 virtual bool is_CFG() const { return true; }
308 virtual uint hash() const { return NO_HASH; } // CFG nodes do not hash
309 virtual const Node *is_block_proj() const { return in(0); }
310 virtual const RegMask &out_RegMask() const;
311 virtual uint ideal_reg() const { return 0; }
312 };
313
314 //---------------------------MultiBranchNode-----------------------------------
315 // This class defines a MultiBranchNode, a MultiNode which yields multiple
316 // control values. These are distinguished from other types of MultiNodes
317 // which yield multiple values, but control is always and only projection #0.
318 class MultiBranchNode : public MultiNode {
319 public:
320 MultiBranchNode( uint required ) : MultiNode(required) {
321 init_class_id(Class_MultiBranch);
322 }
323 // returns required number of users to be well formed.
324 virtual int required_outcnt() const = 0;
325 };
326
327 //------------------------------IfNode-----------------------------------------
328 // Output selected Control, based on a boolean test
329 class IfNode : public MultiBranchNode {
330 // Size is bigger to hold the probability field. However, _prob does not
331 // change the semantics so it does not appear in the hash & cmp functions.
332 virtual uint size_of() const { return sizeof(*this); }
333
334 private:
335 // Helper methods for fold_compares
336 bool cmpi_folds(PhaseIterGVN* igvn, bool fold_ne = false);
337 bool is_ctrl_folds(Node* ctrl, PhaseIterGVN* igvn);
338 bool has_shared_region(ProjNode* proj, ProjNode*& success, ProjNode*& fail);
339 bool has_only_uncommon_traps(ProjNode* proj, ProjNode*& success, ProjNode*& fail, PhaseIterGVN* igvn);
340 Node* merge_uncommon_traps(ProjNode* proj, ProjNode* success, ProjNode* fail, PhaseIterGVN* igvn);
341 static void improve_address_types(Node* l, Node* r, ProjNode* fail, PhaseIterGVN* igvn);
342 bool is_cmp_with_loadrange(ProjNode* proj);
343 bool is_null_check(ProjNode* proj, PhaseIterGVN* igvn);
344 bool is_side_effect_free_test(ProjNode* proj, PhaseIterGVN* igvn);
345 void reroute_side_effect_free_unc(ProjNode* proj, ProjNode* dom_proj, PhaseIterGVN* igvn);
346 ProjNode* uncommon_trap_proj(CallStaticJavaNode*& call) const;
347 bool fold_compares_helper(ProjNode* proj, ProjNode* success, ProjNode* fail, PhaseIterGVN* igvn);
348 static bool is_dominator_unc(CallStaticJavaNode* dom_unc, CallStaticJavaNode* unc);
349
350 protected:
351 ProjNode* range_check_trap_proj(int& flip, Node*& l, Node*& r);
352 Node* Ideal_common(PhaseGVN *phase, bool can_reshape);
353 Node* search_identical(int dist, PhaseIterGVN* igvn);
354
355 Node* simple_subsuming(PhaseIterGVN* igvn);
356
357 public:
358
359 // Degrees of branch prediction probability by order of magnitude:
360 // PROB_UNLIKELY_1e(N) is a 1 in 1eN chance.
361 // PROB_LIKELY_1e(N) is a 1 - PROB_UNLIKELY_1e(N)
362 #define PROB_UNLIKELY_MAG(N) (1e- ## N ## f)
363 #define PROB_LIKELY_MAG(N) (1.0f-PROB_UNLIKELY_MAG(N))
364
365 // Maximum and minimum branch prediction probabilties
366 // 1 in 1,000,000 (magnitude 6)
367 //
368 // Although PROB_NEVER == PROB_MIN and PROB_ALWAYS == PROB_MAX
369 // they are used to distinguish different situations:
370 //
371 // The name PROB_MAX (PROB_MIN) is for probabilities which correspond to
372 // very likely (unlikely) but with a concrete possibility of a rare
373 // contrary case. These constants would be used for pinning
374 // measurements, and as measures for assertions that have high
375 // confidence, but some evidence of occasional failure.
376 //
377 // The name PROB_ALWAYS (PROB_NEVER) is to stand for situations for which
378 // there is no evidence at all that the contrary case has ever occurred.
379
380 #define PROB_NEVER PROB_UNLIKELY_MAG(6)
381 #define PROB_ALWAYS PROB_LIKELY_MAG(6)
382
383 #define PROB_MIN PROB_UNLIKELY_MAG(6)
384 #define PROB_MAX PROB_LIKELY_MAG(6)
385
386 // Static branch prediction probabilities
387 // 1 in 10 (magnitude 1)
388 #define PROB_STATIC_INFREQUENT PROB_UNLIKELY_MAG(1)
389 #define PROB_STATIC_FREQUENT PROB_LIKELY_MAG(1)
390
391 // Fair probability 50/50
392 #define PROB_FAIR (0.5f)
393
394 // Unknown probability sentinel
395 #define PROB_UNKNOWN (-1.0f)
396
397 // Probability "constructors", to distinguish as a probability any manifest
398 // constant without a names
399 #define PROB_LIKELY(x) ((float) (x))
400 #define PROB_UNLIKELY(x) (1.0f - (float)(x))
401
402 // Other probabilities in use, but without a unique name, are documented
403 // here for lack of a better place:
404 //
405 // 1 in 1000 probabilities (magnitude 3):
406 // threshold for converting to conditional move
407 // likelihood of null check failure if a null HAS been seen before
408 // likelihood of slow path taken in library calls
409 //
410 // 1 in 10,000 probabilities (magnitude 4):
411 // threshold for making an uncommon trap probability more extreme
412 // threshold for for making a null check implicit
413 // likelihood of needing a gc if eden top moves during an allocation
414 // likelihood of a predicted call failure
415 //
416 // 1 in 100,000 probabilities (magnitude 5):
417 // threshold for ignoring counts when estimating path frequency
418 // likelihood of FP clipping failure
419 // likelihood of catching an exception from a try block
420 // likelihood of null check failure if a null has NOT been seen before
421 //
422 // Magic manifest probabilities such as 0.83, 0.7, ... can be found in
423 // gen_subtype_check() and catch_inline_exceptions().
424
425 float _prob; // Probability of true path being taken.
426 float _fcnt; // Frequency counter
427 IfNode( Node *control, Node *b, float p, float fcnt )
428 : MultiBranchNode(2), _prob(p), _fcnt(fcnt) {
429 init_class_id(Class_If);
430 init_req(0,control);
431 init_req(1,b);
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 Node* dominated_by(Node* prev_dom, PhaseIterGVN* igvn);
443 bool is_zero_trip_guard() const;
444
445 // Takes the type of val and filters it through the test represented
446 // by if_proj and returns a more refined type if one is produced.
447 // Returns null is it couldn't improve the type.
448 static const TypeInt* filtered_int_type(PhaseGVN* phase, Node* val, Node* if_proj);
449
450 bool is_flat_array_check(PhaseTransform* phase, Node** array = nullptr);
451
452 #ifndef PRODUCT
453 virtual void dump_spec(outputStream *st) const;
454 #endif
455
456 bool same_condition(const Node* dom, PhaseIterGVN* igvn) const;
457 };
458
459 class RangeCheckNode : public IfNode {
460 private:
461 int is_range_check(Node* &range, Node* &index, jint &offset);
462
463 public:
464 RangeCheckNode(Node* control, Node *b, float p, float fcnt)
465 : IfNode(control, b, p, fcnt) {
466 init_class_id(Class_RangeCheck);
467 }
468
469 virtual int Opcode() const;
470 virtual Node* Ideal(PhaseGVN *phase, bool can_reshape);
471 };
472
473 // Special node that denotes a Parse Predicate added during parsing. A Parse Predicate serves as placeholder to later
474 // create Regular Predicates (Runtime Predicates with possible Assertion Predicates) above it. Together they form a
475 // Predicate Block. The Parse Predicate and Regular Predicates share the same uncommon trap.
476 // There are three kinds of Parse Predicates:
477 // Loop Parse Predicate, Profiled Loop Parse Predicate (both used by Loop Predication), and Loop Limit Check Parse
478 // Predicate (used for integer overflow checks when creating a counted loop).
479 // More information about predicates can be found in loopPredicate.cpp.
480 class ParsePredicateNode : public IfNode {
481 Deoptimization::DeoptReason _deopt_reason;
482 bool _useless; // If the associated loop dies, this parse predicate becomes useless and can be cleaned up by Value().
483 public:
484 ParsePredicateNode(Node* control, Deoptimization::DeoptReason deopt_reason, PhaseGVN* gvn);
485 virtual int Opcode() const;
486 virtual uint size_of() const { return sizeof(*this); }
487
488 Deoptimization::DeoptReason deopt_reason() const {
489 return _deopt_reason;
490 }
491
492 bool is_useless() const {
493 return _useless;
494 }
495
496 void mark_useless() {
497 _useless = true;
498 }
499
500 void mark_useful() {
501 _useless = false;
502 }
503
504 Node* uncommon_trap() const;
505
506 Node* Ideal(PhaseGVN* phase, bool can_reshape) {
507 return nullptr; // Don't optimize
508 }
509
510 const Type* Value(PhaseGVN* phase) const;
511 NOT_PRODUCT(void dump_spec(outputStream* st) const;)
512 };
513
514 class IfProjNode : public CProjNode {
515 public:
516 IfProjNode(IfNode *ifnode, uint idx) : CProjNode(ifnode,idx) {}
517 virtual Node* Identity(PhaseGVN* phase);
518
519 protected:
520 // Type of If input when this branch is always taken
521 virtual bool always_taken(const TypeTuple* t) const = 0;
522 };
523
524 class IfTrueNode : public IfProjNode {
525 public:
526 IfTrueNode( IfNode *ifnode ) : IfProjNode(ifnode,1) {
527 init_class_id(Class_IfTrue);
528 }
529 virtual int Opcode() const;
530
531 protected:
532 virtual bool always_taken(const TypeTuple* t) const { return t == TypeTuple::IFTRUE; }
533 };
534
535 class IfFalseNode : public IfProjNode {
536 public:
537 IfFalseNode( IfNode *ifnode ) : IfProjNode(ifnode,0) {
538 init_class_id(Class_IfFalse);
539 }
540 virtual int Opcode() const;
541
542 protected:
543 virtual bool always_taken(const TypeTuple* t) const { return t == TypeTuple::IFFALSE; }
544 };
545
546
547 //------------------------------PCTableNode------------------------------------
548 // Build an indirect branch table. Given a control and a table index,
549 // control is passed to the Projection matching the table index. Used to
550 // implement switch statements and exception-handling capabilities.
551 // Undefined behavior if passed-in index is not inside the table.
552 class PCTableNode : public MultiBranchNode {
553 virtual uint hash() const; // Target count; table size
554 virtual bool cmp( const Node &n ) const;
555 virtual uint size_of() const { return sizeof(*this); }
556
557 public:
558 const uint _size; // Number of targets
559
560 PCTableNode( Node *ctrl, Node *idx, uint size ) : MultiBranchNode(2), _size(size) {
561 init_class_id(Class_PCTable);
562 init_req(0, ctrl);
563 init_req(1, idx);
564 }
565 virtual int Opcode() const;
566 virtual const Type* Value(PhaseGVN* phase) const;
567 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
568 virtual const Type *bottom_type() const;
569 virtual bool pinned() const { return true; }
570 virtual int required_outcnt() const { return _size; }
571 };
572
573 //------------------------------JumpNode---------------------------------------
574 // Indirect branch. Uses PCTable above to implement a switch statement.
575 // It emits as a table load and local branch.
576 class JumpNode : public PCTableNode {
577 virtual uint size_of() const { return sizeof(*this); }
578 public:
579 float* _probs; // probability of each projection
580 float _fcnt; // total number of times this Jump was executed
581 JumpNode( Node* control, Node* switch_val, uint size, float* probs, float cnt)
582 : PCTableNode(control, switch_val, size),
583 _probs(probs), _fcnt(cnt) {
584 init_class_id(Class_Jump);
585 }
586 virtual int Opcode() const;
587 virtual const RegMask& out_RegMask() const;
588 virtual const Node* is_block_proj() const { return this; }
589 };
590
591 class JumpProjNode : public JProjNode {
592 virtual uint hash() const;
593 virtual bool cmp( const Node &n ) const;
594 virtual uint size_of() const { return sizeof(*this); }
595
596 private:
597 const int _dest_bci;
598 const uint _proj_no;
599 const int _switch_val;
600 public:
601 JumpProjNode(Node* jumpnode, uint proj_no, int dest_bci, int switch_val)
602 : JProjNode(jumpnode, proj_no), _dest_bci(dest_bci), _proj_no(proj_no), _switch_val(switch_val) {
603 init_class_id(Class_JumpProj);
604 }
605
606 virtual int Opcode() const;
607 virtual const Type* bottom_type() const { return Type::CONTROL; }
608 int dest_bci() const { return _dest_bci; }
609 int switch_val() const { return _switch_val; }
610 uint proj_no() const { return _proj_no; }
611 #ifndef PRODUCT
612 virtual void dump_spec(outputStream *st) const;
613 virtual void dump_compact_spec(outputStream *st) const;
614 #endif
615 };
616
617 //------------------------------CatchNode--------------------------------------
618 // Helper node to fork exceptions. "Catch" catches any exceptions thrown by
619 // a just-prior call. Looks like a PCTableNode but emits no code - just the
620 // table. The table lookup and branch is implemented by RethrowNode.
621 class CatchNode : public PCTableNode {
622 public:
623 CatchNode( Node *ctrl, Node *idx, uint size ) : PCTableNode(ctrl,idx,size){
624 init_class_id(Class_Catch);
625 }
626 virtual int Opcode() const;
627 virtual const Type* Value(PhaseGVN* phase) const;
628 };
629
630 // CatchProjNode controls which exception handler is targeted after a call.
631 // It is passed in the bci of the target handler, or no_handler_bci in case
632 // the projection doesn't lead to an exception handler.
633 class CatchProjNode : public CProjNode {
634 virtual uint hash() const;
635 virtual bool cmp( const Node &n ) const;
636 virtual uint size_of() const { return sizeof(*this); }
637
638 private:
639 const int _handler_bci;
640
641 public:
642 enum {
643 fall_through_index = 0, // the fall through projection index
644 catch_all_index = 1, // the projection index for catch-alls
645 no_handler_bci = -1 // the bci for fall through or catch-all projs
646 };
647
648 CatchProjNode(Node* catchnode, uint proj_no, int handler_bci)
649 : CProjNode(catchnode, proj_no), _handler_bci(handler_bci) {
650 init_class_id(Class_CatchProj);
651 assert(proj_no != fall_through_index || handler_bci < 0, "fall through case must have bci < 0");
652 }
653
654 virtual int Opcode() const;
655 virtual Node* Identity(PhaseGVN* phase);
656 virtual const Type *bottom_type() const { return Type::CONTROL; }
657 int handler_bci() const { return _handler_bci; }
658 bool is_handler_proj() const { return _handler_bci >= 0; }
659 #ifndef PRODUCT
660 virtual void dump_spec(outputStream *st) const;
661 #endif
662 };
663
664
665 //---------------------------------CreateExNode--------------------------------
666 // Helper node to create the exception coming back from a call
667 class CreateExNode : public TypeNode {
668 public:
669 CreateExNode(const Type* t, Node* control, Node* i_o) : TypeNode(t, 2) {
670 init_req(0, control);
671 init_req(1, i_o);
672 }
673 virtual int Opcode() const;
674 virtual Node* Identity(PhaseGVN* phase);
675 virtual bool pinned() const { return true; }
676 uint match_edge(uint idx) const { return 0; }
677 virtual uint ideal_reg() const { return Op_RegP; }
678 };
679
680 //------------------------------NeverBranchNode-------------------------------
681 // The never-taken branch. Used to give the appearance of exiting infinite
682 // loops to those algorithms that like all paths to be reachable. Encodes
683 // empty.
684 class NeverBranchNode : public MultiBranchNode {
685 public:
686 NeverBranchNode(Node* ctrl) : MultiBranchNode(1) {
687 init_req(0, ctrl);
688 init_class_id(Class_NeverBranch);
689 }
690 virtual int Opcode() const;
691 virtual bool pinned() const { return true; };
692 virtual const Type *bottom_type() const { return TypeTuple::IFBOTH; }
693 virtual const Type* Value(PhaseGVN* phase) const;
694 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
695 virtual int required_outcnt() const { return 2; }
696 virtual void emit(CodeBuffer &cbuf, PhaseRegAlloc *ra_) const { }
697 virtual uint size(PhaseRegAlloc *ra_) const { return 0; }
698 #ifndef PRODUCT
699 virtual void format( PhaseRegAlloc *, outputStream *st ) const;
700 #endif
701 };
702
703 //------------------------------BlackholeNode----------------------------
704 // Blackhole all arguments. This node would survive through the compiler
705 // the effects on its arguments, and would be finally matched to nothing.
706 class BlackholeNode : public MultiNode {
707 public:
708 BlackholeNode(Node* ctrl) : MultiNode(1) {
709 init_req(TypeFunc::Control, ctrl);
710 init_class_id(Class_Blackhole);
711 }
712 virtual int Opcode() const;
713 virtual uint ideal_reg() const { return 0; } // not matched in the AD file
714 virtual const Type* bottom_type() const { return TypeTuple::MEMBAR; }
715
716 const RegMask &in_RegMask(uint idx) const {
717 // Fake the incoming arguments mask for blackholes: accept all registers
718 // and all stack slots. This would avoid any redundant register moves
719 // for blackhole inputs.
720 return RegMask::All;
721 }
722 #ifndef PRODUCT
723 virtual void format(PhaseRegAlloc* ra, outputStream* st) const;
724 #endif
725 };
726
727
728 #endif // SHARE_OPTO_CFGNODE_HPP