1 /* 2 * Copyright (c) 1997, 2024, 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 * 15 * You should have received a copy of the GNU General Public License version 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. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 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 enum class AssertionPredicateType; 61 62 // The success projection of a Parse Predicate is always an IfTrueNode and the uncommon projection an IfFalseNode 63 typedef IfTrueNode ParsePredicateSuccessProj; 64 typedef IfFalseNode ParsePredicateUncommonProj; 65 66 //------------------------------RegionNode------------------------------------- 67 // The class of RegionNodes, which can be mapped to basic blocks in the 68 // program. Their inputs point to Control sources. PhiNodes (described 69 // below) have an input point to a RegionNode. Merged data inputs to PhiNodes 70 // correspond 1-to-1 with RegionNode inputs. The zero input of a PhiNode is 71 // the RegionNode, and the zero input of the RegionNode is itself. 72 class RegionNode : public Node { 73 public: 74 enum LoopStatus { 75 // No guarantee: the region may be an irreducible loop entry, thus we have to 76 // be careful when removing entry control to it. 77 MaybeIrreducibleEntry, 78 // Limited guarantee: this region may be (nested) inside an irreducible loop, 79 // but it will never be an irreducible loop entry. 80 NeverIrreducibleEntry, 81 // Strong guarantee: this region is not (nested) inside an irreducible loop. 82 Reducible, 83 }; 84 85 private: 86 bool _is_unreachable_region; 87 LoopStatus _loop_status; 88 89 bool is_possible_unsafe_loop(const PhaseGVN* phase) const; 90 bool is_unreachable_from_root(const PhaseGVN* phase) const; 91 public: 92 // Node layout (parallels PhiNode): 93 enum { Region, // Generally points to self. 94 Control // Control arcs are [1..len) 95 }; 96 97 RegionNode(uint required) 98 : Node(required), 99 _is_unreachable_region(false), 100 _loop_status(LoopStatus::NeverIrreducibleEntry) 101 { 102 init_class_id(Class_Region); 103 init_req(0, this); 104 } 105 106 Node* is_copy() const { 107 const Node* r = _in[Region]; 108 if (r == nullptr) 109 return nonnull_req(); 110 return nullptr; // not a copy! 111 } 112 PhiNode* has_phi() const; // returns an arbitrary phi user, or null 113 PhiNode* has_unique_phi() const; // returns the unique phi user, or null 114 // Is this region node unreachable from root? 115 bool is_unreachable_region(const PhaseGVN* phase); 116 #ifdef ASSERT 117 bool is_in_infinite_subgraph(); 118 static bool are_all_nodes_in_infinite_subgraph(Unique_Node_List& worklist); 119 #endif //ASSERT 120 LoopStatus loop_status() const { return _loop_status; }; 121 void set_loop_status(LoopStatus status); 122 DEBUG_ONLY(void verify_can_be_irreducible_entry() const;) 123 124 virtual int Opcode() const; 125 virtual uint size_of() const { return sizeof(*this); } 126 virtual bool pinned() const { return (const Node*)in(0) == this; } 127 virtual bool is_CFG() const { return true; } 128 virtual uint hash() const { return NO_HASH; } // CFG nodes do not hash 129 virtual bool depends_only_on_test() const { return false; } 130 virtual const Type* bottom_type() const { return Type::CONTROL; } 131 virtual const Type* Value(PhaseGVN* phase) const; 132 virtual Node* Identity(PhaseGVN* phase); 133 virtual Node* Ideal(PhaseGVN* phase, bool can_reshape); 134 void remove_unreachable_subgraph(PhaseIterGVN* igvn); 135 virtual const RegMask &out_RegMask() const; 136 bool is_diamond() const; 137 void try_clean_mem_phis(PhaseIterGVN* phase); 138 bool optimize_trichotomy(PhaseIterGVN* igvn); 139 NOT_PRODUCT(virtual void dump_spec(outputStream* st) const;) 140 }; 141 142 //------------------------------JProjNode-------------------------------------- 143 // jump projection for node that produces multiple control-flow paths 144 class JProjNode : public ProjNode { 145 public: 146 JProjNode( Node* ctrl, uint idx ) : ProjNode(ctrl,idx) {} 147 virtual int Opcode() const; 148 virtual bool is_CFG() const { return true; } 149 virtual uint hash() const { return NO_HASH; } // CFG nodes do not hash 150 virtual const Node* is_block_proj() const { return in(0); } 151 virtual const RegMask& out_RegMask() const; 152 virtual uint ideal_reg() const { return 0; } 153 }; 154 155 //------------------------------PhiNode---------------------------------------- 156 // PhiNodes merge values from different Control paths. Slot 0 points to the 157 // controlling RegionNode. Other slots map 1-for-1 with incoming control flow 158 // paths to the RegionNode. 159 class PhiNode : public TypeNode { 160 friend class PhaseRenumberLive; 161 162 const TypePtr* const _adr_type; // non-null only for Type::MEMORY nodes. 163 // The following fields are only used for data PhiNodes to indicate 164 // that the PhiNode represents the value of a known instance field. 165 int _inst_mem_id; // Instance memory id (node index of the memory Phi) 166 int _inst_id; // Instance id of the memory slice. 167 const int _inst_index; // Alias index of the instance memory slice. 168 // Array elements references have the same alias_idx but different offset. 169 const int _inst_offset; // Offset of the instance memory slice. 170 // Size is bigger to hold the _adr_type field. 171 virtual uint hash() const; // Check the type 172 virtual bool cmp( const Node &n ) const; 173 virtual uint size_of() const { return sizeof(*this); } 174 175 // Determine if CMoveNode::is_cmove_id can be used at this join point. 176 Node* is_cmove_id(PhaseTransform* phase, int true_path); 177 bool wait_for_region_igvn(PhaseGVN* phase); 178 bool is_data_loop(RegionNode* r, Node* uin, const PhaseGVN* phase); 179 180 static Node* clone_through_phi(Node* root_phi, const Type* t, uint c, PhaseIterGVN* igvn); 181 static Node* merge_through_phi(Node* root_phi, PhaseIterGVN* igvn); 182 183 bool must_wait_for_region_in_irreducible_loop(PhaseGVN* phase) const; 184 185 bool can_push_inline_types_down(PhaseGVN* phase, bool can_reshape, ciInlineKlass*& inline_klass); 186 InlineTypeNode* push_inline_types_down(PhaseGVN* phase, bool can_reshape, ciInlineKlass* inline_klass); 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 } 235 236 // Check for a simple dead loop. 237 enum LoopSafety { Safe = 0, Unsafe, UnsafeLoop }; 238 LoopSafety simple_data_loop_check(Node *in) const; 239 // Is it unsafe data loop? It becomes a dead loop if this phi node removed. 240 bool is_unsafe_data_reference(Node *in) const; 241 int is_diamond_phi() const; 242 bool try_clean_memory_phi(PhaseIterGVN* igvn); 243 virtual int Opcode() const; 244 virtual bool pinned() const { return in(0) != nullptr; } 245 virtual const TypePtr *adr_type() const { verify_adr_type(true); return _adr_type; } 246 247 void set_inst_mem_id(int inst_mem_id) { _inst_mem_id = inst_mem_id; } 248 int inst_mem_id() const { return _inst_mem_id; } 249 int inst_id() const { return _inst_id; } 250 int inst_index() const { return _inst_index; } 251 int inst_offset() const { return _inst_offset; } 252 bool is_same_inst_field(const Type* tp, int mem_id, int id, int index, int offset) { 253 return type()->basic_type() == tp->basic_type() && 254 inst_mem_id() == mem_id && 255 inst_id() == id && 256 inst_index() == index && 257 inst_offset() == offset && 258 type()->higher_equal(tp); 259 } 260 261 bool can_be_inline_type() const { 262 return EnableValhalla && _type->isa_instptr() && _type->is_instptr()->can_be_inline_type(); 263 } 264 265 Node* try_push_inline_types_down(PhaseGVN* phase, bool can_reshape); 266 DEBUG_ONLY(bool can_push_inline_types_down(PhaseGVN* phase);) 267 268 virtual const Type* Value(PhaseGVN* phase) const; 269 virtual Node* Identity(PhaseGVN* phase); 270 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape); 271 virtual const RegMask &out_RegMask() const; 272 virtual const RegMask &in_RegMask(uint) const; 273 #ifndef PRODUCT 274 virtual void dump_spec(outputStream *st) const; 275 #endif 276 #ifdef ASSERT 277 void verify_adr_type(VectorSet& visited, const TypePtr* at) const; 278 void verify_adr_type(bool recursive = false) const; 279 #else //ASSERT 280 void verify_adr_type(bool recursive = false) const {} 281 #endif //ASSERT 282 283 const TypeTuple* collect_types(PhaseGVN* phase) const; 284 }; 285 286 //------------------------------GotoNode--------------------------------------- 287 // GotoNodes perform direct branches. 288 class GotoNode : public Node { 289 public: 290 GotoNode( Node *control ) : Node(control) {} 291 virtual int Opcode() const; 292 virtual bool pinned() const { return true; } 293 virtual bool is_CFG() const { return true; } 294 virtual uint hash() const { return NO_HASH; } // CFG nodes do not hash 295 virtual const Node *is_block_proj() const { return this; } 296 virtual bool depends_only_on_test() const { return false; } 297 virtual const Type *bottom_type() const { return Type::CONTROL; } 298 virtual const Type* Value(PhaseGVN* phase) const; 299 virtual Node* Identity(PhaseGVN* phase); 300 virtual const RegMask &out_RegMask() const; 301 }; 302 303 //------------------------------CProjNode-------------------------------------- 304 // control projection for node that produces multiple control-flow paths 305 class CProjNode : public ProjNode { 306 public: 307 CProjNode( Node *ctrl, uint idx ) : ProjNode(ctrl,idx) {} 308 virtual int Opcode() const; 309 virtual bool is_CFG() const { return true; } 310 virtual uint hash() const { return NO_HASH; } // CFG nodes do not hash 311 virtual const Node *is_block_proj() const { return in(0); } 312 virtual const RegMask &out_RegMask() const; 313 virtual uint ideal_reg() const { return 0; } 314 }; 315 316 //---------------------------MultiBranchNode----------------------------------- 317 // This class defines a MultiBranchNode, a MultiNode which yields multiple 318 // control values. These are distinguished from other types of MultiNodes 319 // which yield multiple values, but control is always and only projection #0. 320 class MultiBranchNode : public MultiNode { 321 public: 322 MultiBranchNode( uint required ) : MultiNode(required) { 323 init_class_id(Class_MultiBranch); 324 } 325 // returns required number of users to be well formed. 326 virtual int required_outcnt() const = 0; 327 }; 328 329 //------------------------------IfNode----------------------------------------- 330 // Output selected Control, based on a boolean test 331 class IfNode : public MultiBranchNode { 332 public: 333 float _prob; // Probability of true path being taken. 334 float _fcnt; // Frequency counter 335 336 private: 337 AssertionPredicateType _assertion_predicate_type; 338 339 void init_node(Node* control, Node* bol) { 340 init_class_id(Class_If); 341 init_req(0, control); 342 init_req(1, bol); 343 } 344 345 // Size is bigger to hold the probability field. However, _prob does not 346 // change the semantics so it does not appear in the hash & cmp functions. 347 virtual uint size_of() const { return sizeof(*this); } 348 349 // Helper methods for fold_compares 350 bool cmpi_folds(PhaseIterGVN* igvn, bool fold_ne = false); 351 bool is_ctrl_folds(Node* ctrl, PhaseIterGVN* igvn); 352 bool has_shared_region(ProjNode* proj, ProjNode*& success, ProjNode*& fail); 353 bool has_only_uncommon_traps(ProjNode* proj, ProjNode*& success, ProjNode*& fail, PhaseIterGVN* igvn); 354 Node* merge_uncommon_traps(ProjNode* proj, ProjNode* success, ProjNode* fail, PhaseIterGVN* igvn); 355 static void improve_address_types(Node* l, Node* r, ProjNode* fail, PhaseIterGVN* igvn); 356 bool is_cmp_with_loadrange(ProjNode* proj); 357 bool is_null_check(ProjNode* proj, PhaseIterGVN* igvn); 358 bool is_side_effect_free_test(ProjNode* proj, PhaseIterGVN* igvn); 359 void reroute_side_effect_free_unc(ProjNode* proj, ProjNode* dom_proj, PhaseIterGVN* igvn); 360 bool fold_compares_helper(ProjNode* proj, ProjNode* success, ProjNode* fail, PhaseIterGVN* igvn); 361 static bool is_dominator_unc(CallStaticJavaNode* dom_unc, CallStaticJavaNode* unc); 362 363 protected: 364 ProjNode* range_check_trap_proj(int& flip, Node*& l, Node*& r); 365 Node* Ideal_common(PhaseGVN *phase, bool can_reshape); 366 Node* search_identical(int dist, PhaseIterGVN* igvn); 367 368 Node* simple_subsuming(PhaseIterGVN* igvn); 369 370 public: 371 372 // Degrees of branch prediction probability by order of magnitude: 373 // PROB_UNLIKELY_1e(N) is a 1 in 1eN chance. 374 // PROB_LIKELY_1e(N) is a 1 - PROB_UNLIKELY_1e(N) 375 #define PROB_UNLIKELY_MAG(N) (1e- ## N ## f) 376 #define PROB_LIKELY_MAG(N) (1.0f-PROB_UNLIKELY_MAG(N)) 377 378 // Maximum and minimum branch prediction probabilties 379 // 1 in 1,000,000 (magnitude 6) 380 // 381 // Although PROB_NEVER == PROB_MIN and PROB_ALWAYS == PROB_MAX 382 // they are used to distinguish different situations: 383 // 384 // The name PROB_MAX (PROB_MIN) is for probabilities which correspond to 385 // very likely (unlikely) but with a concrete possibility of a rare 386 // contrary case. These constants would be used for pinning 387 // measurements, and as measures for assertions that have high 388 // confidence, but some evidence of occasional failure. 389 // 390 // The name PROB_ALWAYS (PROB_NEVER) is to stand for situations for which 391 // there is no evidence at all that the contrary case has ever occurred. 392 393 #define PROB_NEVER PROB_UNLIKELY_MAG(6) 394 #define PROB_ALWAYS PROB_LIKELY_MAG(6) 395 396 #define PROB_MIN PROB_UNLIKELY_MAG(6) 397 #define PROB_MAX PROB_LIKELY_MAG(6) 398 399 // Static branch prediction probabilities 400 // 1 in 10 (magnitude 1) 401 #define PROB_STATIC_INFREQUENT PROB_UNLIKELY_MAG(1) 402 #define PROB_STATIC_FREQUENT PROB_LIKELY_MAG(1) 403 404 // Fair probability 50/50 405 #define PROB_FAIR (0.5f) 406 407 // Unknown probability sentinel 408 #define PROB_UNKNOWN (-1.0f) 409 410 // Probability "constructors", to distinguish as a probability any manifest 411 // constant without a names 412 #define PROB_LIKELY(x) ((float) (x)) 413 #define PROB_UNLIKELY(x) (1.0f - (float)(x)) 414 415 // Other probabilities in use, but without a unique name, are documented 416 // here for lack of a better place: 417 // 418 // 1 in 1000 probabilities (magnitude 3): 419 // threshold for converting to conditional move 420 // likelihood of null check failure if a null HAS been seen before 421 // likelihood of slow path taken in library calls 422 // 423 // 1 in 10,000 probabilities (magnitude 4): 424 // threshold for making an uncommon trap probability more extreme 425 // threshold for for making a null check implicit 426 // likelihood of needing a gc if eden top moves during an allocation 427 // likelihood of a predicted call failure 428 // 429 // 1 in 100,000 probabilities (magnitude 5): 430 // threshold for ignoring counts when estimating path frequency 431 // likelihood of FP clipping failure 432 // likelihood of catching an exception from a try block 433 // likelihood of null check failure if a null has NOT been seen before 434 // 435 // Magic manifest probabilities such as 0.83, 0.7, ... can be found in 436 // gen_subtype_check() and catch_inline_exceptions(). 437 438 IfNode(Node* control, Node* bol, float p, float fcnt); 439 IfNode(Node* control, Node* bol, float p, float fcnt, AssertionPredicateType assertion_predicate_type); 440 441 static IfNode* make_with_same_profile(IfNode* if_node_profile, Node* ctrl, BoolNode* bol); 442 443 virtual int Opcode() const; 444 virtual bool pinned() const { return true; } 445 virtual const Type *bottom_type() const { return TypeTuple::IFBOTH; } 446 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape); 447 virtual const Type* Value(PhaseGVN* phase) const; 448 virtual int required_outcnt() const { return 2; } 449 virtual const RegMask &out_RegMask() const; 450 Node* fold_compares(PhaseIterGVN* phase); 451 static Node* up_one_dom(Node* curr, bool linear_only = false); 452 bool is_zero_trip_guard() const; 453 Node* dominated_by(Node* prev_dom, PhaseIterGVN* igvn, bool pin_array_access_nodes); 454 ProjNode* uncommon_trap_proj(CallStaticJavaNode*& call, Deoptimization::DeoptReason reason = Deoptimization::Reason_none) const; 455 456 // Takes the type of val and filters it through the test represented 457 // by if_proj and returns a more refined type if one is produced. 458 // Returns null is it couldn't improve the type. 459 static const TypeInt* filtered_int_type(PhaseGVN* phase, Node* val, Node* if_proj); 460 461 bool is_flat_array_check(PhaseTransform* phase, Node** array = nullptr); 462 463 AssertionPredicateType assertion_predicate_type() const { 464 return _assertion_predicate_type; 465 } 466 467 #ifndef PRODUCT 468 virtual void dump_spec(outputStream *st) const; 469 #endif 470 471 bool same_condition(const Node* dom, PhaseIterGVN* igvn) const; 472 }; 473 474 class RangeCheckNode : public IfNode { 475 private: 476 int is_range_check(Node*& range, Node*& index, jint& offset); 477 478 public: 479 RangeCheckNode(Node* control, Node* bol, float p, float fcnt) : IfNode(control, bol, p, fcnt) { 480 init_class_id(Class_RangeCheck); 481 } 482 483 RangeCheckNode(Node* control, Node* bol, float p, float fcnt, AssertionPredicateType assertion_predicate_type) 484 : IfNode(control, bol, p, fcnt, assertion_predicate_type) { 485 init_class_id(Class_RangeCheck); 486 } 487 488 virtual int Opcode() const; 489 virtual Node* Ideal(PhaseGVN *phase, bool can_reshape); 490 }; 491 492 // Special node that denotes a Parse Predicate added during parsing. A Parse Predicate serves as placeholder to later 493 // create Regular Predicates (Runtime Predicates with possible Assertion Predicates) above it. Together they form a 494 // Predicate Block. The Parse Predicate and Regular Predicates share the same uncommon trap. 495 // There are three kinds of Parse Predicates: 496 // Loop Parse Predicate, Profiled Loop Parse Predicate (both used by Loop Predication), and Loop Limit Check Parse 497 // Predicate (used for integer overflow checks when creating a counted loop). 498 // More information about predicates can be found in loopPredicate.cpp. 499 class ParsePredicateNode : public IfNode { 500 Deoptimization::DeoptReason _deopt_reason; 501 bool _useless; // If the associated loop dies, this parse predicate becomes useless and can be cleaned up by Value(). 502 public: 503 ParsePredicateNode(Node* control, Deoptimization::DeoptReason deopt_reason, PhaseGVN* gvn); 504 virtual int Opcode() const; 505 virtual uint size_of() const { return sizeof(*this); } 506 507 Deoptimization::DeoptReason deopt_reason() const { 508 return _deopt_reason; 509 } 510 511 bool is_useless() const { 512 return _useless; 513 } 514 515 void mark_useless() { 516 _useless = true; 517 } 518 519 void mark_useful() { 520 _useless = false; 521 } 522 523 // Return the uncommon trap If projection of this Parse Predicate. 524 ParsePredicateUncommonProj* uncommon_proj() const { 525 return proj_out(0)->as_IfFalse(); 526 } 527 528 Node* uncommon_trap() const; 529 530 Node* Ideal(PhaseGVN* phase, bool can_reshape) { 531 return nullptr; // Don't optimize 532 } 533 534 const Type* Value(PhaseGVN* phase) const; 535 NOT_PRODUCT(void dump_spec(outputStream* st) const;) 536 }; 537 538 class IfProjNode : public CProjNode { 539 public: 540 IfProjNode(IfNode *ifnode, uint idx) : CProjNode(ifnode,idx) {} 541 virtual Node* Identity(PhaseGVN* phase); 542 543 void pin_array_access_nodes(PhaseIterGVN* igvn); 544 545 protected: 546 // Type of If input when this branch is always taken 547 virtual bool always_taken(const TypeTuple* t) const = 0; 548 }; 549 550 class IfTrueNode : public IfProjNode { 551 public: 552 IfTrueNode( IfNode *ifnode ) : IfProjNode(ifnode,1) { 553 init_class_id(Class_IfTrue); 554 } 555 virtual int Opcode() const; 556 557 protected: 558 virtual bool always_taken(const TypeTuple* t) const { return t == TypeTuple::IFTRUE; } 559 }; 560 561 class IfFalseNode : public IfProjNode { 562 public: 563 IfFalseNode( IfNode *ifnode ) : IfProjNode(ifnode,0) { 564 init_class_id(Class_IfFalse); 565 } 566 virtual int Opcode() const; 567 568 protected: 569 virtual bool always_taken(const TypeTuple* t) const { return t == TypeTuple::IFFALSE; } 570 }; 571 572 573 //------------------------------PCTableNode------------------------------------ 574 // Build an indirect branch table. Given a control and a table index, 575 // control is passed to the Projection matching the table index. Used to 576 // implement switch statements and exception-handling capabilities. 577 // Undefined behavior if passed-in index is not inside the table. 578 class PCTableNode : public MultiBranchNode { 579 virtual uint hash() const; // Target count; table size 580 virtual bool cmp( const Node &n ) const; 581 virtual uint size_of() const { return sizeof(*this); } 582 583 public: 584 const uint _size; // Number of targets 585 586 PCTableNode( Node *ctrl, Node *idx, uint size ) : MultiBranchNode(2), _size(size) { 587 init_class_id(Class_PCTable); 588 init_req(0, ctrl); 589 init_req(1, idx); 590 } 591 virtual int Opcode() const; 592 virtual const Type* Value(PhaseGVN* phase) const; 593 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape); 594 virtual const Type *bottom_type() const; 595 virtual bool pinned() const { return true; } 596 virtual int required_outcnt() const { return _size; } 597 }; 598 599 //------------------------------JumpNode--------------------------------------- 600 // Indirect branch. Uses PCTable above to implement a switch statement. 601 // It emits as a table load and local branch. 602 class JumpNode : public PCTableNode { 603 virtual uint size_of() const { return sizeof(*this); } 604 public: 605 float* _probs; // probability of each projection 606 float _fcnt; // total number of times this Jump was executed 607 JumpNode( Node* control, Node* switch_val, uint size, float* probs, float cnt) 608 : PCTableNode(control, switch_val, size), 609 _probs(probs), _fcnt(cnt) { 610 init_class_id(Class_Jump); 611 } 612 virtual int Opcode() const; 613 virtual const RegMask& out_RegMask() const; 614 virtual const Node* is_block_proj() const { return this; } 615 }; 616 617 class JumpProjNode : public JProjNode { 618 virtual uint hash() const; 619 virtual bool cmp( const Node &n ) const; 620 virtual uint size_of() const { return sizeof(*this); } 621 622 private: 623 const int _dest_bci; 624 const uint _proj_no; 625 const int _switch_val; 626 public: 627 JumpProjNode(Node* jumpnode, uint proj_no, int dest_bci, int switch_val) 628 : JProjNode(jumpnode, proj_no), _dest_bci(dest_bci), _proj_no(proj_no), _switch_val(switch_val) { 629 init_class_id(Class_JumpProj); 630 } 631 632 virtual int Opcode() const; 633 virtual const Type* bottom_type() const { return Type::CONTROL; } 634 int dest_bci() const { return _dest_bci; } 635 int switch_val() const { return _switch_val; } 636 uint proj_no() const { return _proj_no; } 637 #ifndef PRODUCT 638 virtual void dump_spec(outputStream *st) const; 639 virtual void dump_compact_spec(outputStream *st) const; 640 #endif 641 }; 642 643 //------------------------------CatchNode-------------------------------------- 644 // Helper node to fork exceptions. "Catch" catches any exceptions thrown by 645 // a just-prior call. Looks like a PCTableNode but emits no code - just the 646 // table. The table lookup and branch is implemented by RethrowNode. 647 class CatchNode : public PCTableNode { 648 public: 649 CatchNode( Node *ctrl, Node *idx, uint size ) : PCTableNode(ctrl,idx,size){ 650 init_class_id(Class_Catch); 651 } 652 virtual int Opcode() const; 653 virtual const Type* Value(PhaseGVN* phase) const; 654 }; 655 656 // CatchProjNode controls which exception handler is targeted after a call. 657 // It is passed in the bci of the target handler, or no_handler_bci in case 658 // the projection doesn't lead to an exception handler. 659 class CatchProjNode : public CProjNode { 660 virtual uint hash() const; 661 virtual bool cmp( const Node &n ) const; 662 virtual uint size_of() const { return sizeof(*this); } 663 664 private: 665 const int _handler_bci; 666 667 public: 668 enum { 669 fall_through_index = 0, // the fall through projection index 670 catch_all_index = 1, // the projection index for catch-alls 671 no_handler_bci = -1 // the bci for fall through or catch-all projs 672 }; 673 674 CatchProjNode(Node* catchnode, uint proj_no, int handler_bci) 675 : CProjNode(catchnode, proj_no), _handler_bci(handler_bci) { 676 init_class_id(Class_CatchProj); 677 assert(proj_no != fall_through_index || handler_bci < 0, "fall through case must have bci < 0"); 678 } 679 680 virtual int Opcode() const; 681 virtual Node* Identity(PhaseGVN* phase); 682 virtual const Type *bottom_type() const { return Type::CONTROL; } 683 int handler_bci() const { return _handler_bci; } 684 bool is_handler_proj() const { return _handler_bci >= 0; } 685 #ifndef PRODUCT 686 virtual void dump_spec(outputStream *st) const; 687 #endif 688 }; 689 690 691 //---------------------------------CreateExNode-------------------------------- 692 // Helper node to create the exception coming back from a call 693 class CreateExNode : public TypeNode { 694 public: 695 CreateExNode(const Type* t, Node* control, Node* i_o) : TypeNode(t, 2) { 696 init_req(0, control); 697 init_req(1, i_o); 698 } 699 virtual int Opcode() const; 700 virtual Node* Identity(PhaseGVN* phase); 701 virtual bool pinned() const { return true; } 702 uint match_edge(uint idx) const { return 0; } 703 virtual uint ideal_reg() const { return Op_RegP; } 704 }; 705 706 //------------------------------NeverBranchNode------------------------------- 707 // The never-taken branch. Used to give the appearance of exiting infinite 708 // loops to those algorithms that like all paths to be reachable. Encodes 709 // empty. 710 class NeverBranchNode : public MultiBranchNode { 711 public: 712 NeverBranchNode(Node* ctrl) : MultiBranchNode(1) { 713 init_req(0, ctrl); 714 init_class_id(Class_NeverBranch); 715 } 716 virtual int Opcode() const; 717 virtual bool pinned() const { return true; }; 718 virtual const Type *bottom_type() const { return TypeTuple::IFBOTH; } 719 virtual const Type* Value(PhaseGVN* phase) const; 720 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape); 721 virtual int required_outcnt() const { return 2; } 722 virtual void emit(C2_MacroAssembler *masm, PhaseRegAlloc *ra_) const { } 723 virtual uint size(PhaseRegAlloc *ra_) const { return 0; } 724 #ifndef PRODUCT 725 virtual void format( PhaseRegAlloc *, outputStream *st ) const; 726 #endif 727 }; 728 729 //------------------------------BlackholeNode---------------------------- 730 // Blackhole all arguments. This node would survive through the compiler 731 // the effects on its arguments, and would be finally matched to nothing. 732 class BlackholeNode : public MultiNode { 733 public: 734 BlackholeNode(Node* ctrl) : MultiNode(1) { 735 init_req(TypeFunc::Control, ctrl); 736 init_class_id(Class_Blackhole); 737 } 738 virtual int Opcode() const; 739 virtual uint ideal_reg() const { return 0; } // not matched in the AD file 740 virtual const Type* bottom_type() const { return TypeTuple::MEMBAR; } 741 742 const RegMask &in_RegMask(uint idx) const { 743 // Fake the incoming arguments mask for blackholes: accept all registers 744 // and all stack slots. This would avoid any redundant register moves 745 // for blackhole inputs. 746 return RegMask::All; 747 } 748 #ifndef PRODUCT 749 virtual void format(PhaseRegAlloc* ra, outputStream* st) const; 750 #endif 751 }; 752 753 754 #endif // SHARE_OPTO_CFGNODE_HPP