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 * 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 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 } 433 434 static IfNode* make_with_same_profile(IfNode* if_node_profile, Node* ctrl, BoolNode* bol); 435 436 virtual int Opcode() const; 437 virtual bool pinned() const { return true; } 438 virtual const Type *bottom_type() const { return TypeTuple::IFBOTH; } 439 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape); 440 virtual const Type* Value(PhaseGVN* phase) const; 441 virtual int required_outcnt() const { return 2; } 442 virtual const RegMask &out_RegMask() const; 443 Node* fold_compares(PhaseIterGVN* phase); 444 static Node* up_one_dom(Node* curr, bool linear_only = false); 445 bool is_zero_trip_guard() const; 446 Node* dominated_by(Node* prev_dom, PhaseIterGVN* igvn, bool pin_array_access_nodes); 447 448 // Takes the type of val and filters it through the test represented 449 // by if_proj and returns a more refined type if one is produced. 450 // Returns null is it couldn't improve the type. 451 static const TypeInt* filtered_int_type(PhaseGVN* phase, Node* val, Node* if_proj); 452 453 bool is_flat_array_check(PhaseTransform* phase, Node** array = nullptr); 454 455 #ifndef PRODUCT 456 virtual void dump_spec(outputStream *st) const; 457 #endif 458 459 bool same_condition(const Node* dom, PhaseIterGVN* igvn) const; 460 }; 461 462 class RangeCheckNode : public IfNode { 463 private: 464 int is_range_check(Node* &range, Node* &index, jint &offset); 465 466 public: 467 RangeCheckNode(Node* control, Node *b, float p, float fcnt) 468 : IfNode(control, b, p, fcnt) { 469 init_class_id(Class_RangeCheck); 470 } 471 472 virtual int Opcode() const; 473 virtual Node* Ideal(PhaseGVN *phase, bool can_reshape); 474 }; 475 476 // Special node that denotes a Parse Predicate added during parsing. A Parse Predicate serves as placeholder to later 477 // create Regular Predicates (Runtime Predicates with possible Assertion Predicates) above it. Together they form a 478 // Predicate Block. The Parse Predicate and Regular Predicates share the same uncommon trap. 479 // There are three kinds of Parse Predicates: 480 // Loop Parse Predicate, Profiled Loop Parse Predicate (both used by Loop Predication), and Loop Limit Check Parse 481 // Predicate (used for integer overflow checks when creating a counted loop). 482 // More information about predicates can be found in loopPredicate.cpp. 483 class ParsePredicateNode : public IfNode { 484 Deoptimization::DeoptReason _deopt_reason; 485 bool _useless; // If the associated loop dies, this parse predicate becomes useless and can be cleaned up by Value(). 486 public: 487 ParsePredicateNode(Node* control, Deoptimization::DeoptReason deopt_reason, PhaseGVN* gvn); 488 virtual int Opcode() const; 489 virtual uint size_of() const { return sizeof(*this); } 490 491 Deoptimization::DeoptReason deopt_reason() const { 492 return _deopt_reason; 493 } 494 495 bool is_useless() const { 496 return _useless; 497 } 498 499 void mark_useless() { 500 _useless = true; 501 } 502 503 void mark_useful() { 504 _useless = false; 505 } 506 507 // Return the uncommon trap If projection of this Parse Predicate. 508 ParsePredicateUncommonProj* uncommon_proj() const { 509 return proj_out(0)->as_IfFalse(); 510 } 511 512 Node* uncommon_trap() const; 513 514 Node* Ideal(PhaseGVN* phase, bool can_reshape) { 515 return nullptr; // Don't optimize 516 } 517 518 const Type* Value(PhaseGVN* phase) const; 519 NOT_PRODUCT(void dump_spec(outputStream* st) const;) 520 }; 521 522 class IfProjNode : public CProjNode { 523 public: 524 IfProjNode(IfNode *ifnode, uint idx) : CProjNode(ifnode,idx) {} 525 virtual Node* Identity(PhaseGVN* phase); 526 527 void pin_array_access_nodes(PhaseIterGVN* igvn); 528 529 protected: 530 // Type of If input when this branch is always taken 531 virtual bool always_taken(const TypeTuple* t) const = 0; 532 }; 533 534 class IfTrueNode : public IfProjNode { 535 public: 536 IfTrueNode( IfNode *ifnode ) : IfProjNode(ifnode,1) { 537 init_class_id(Class_IfTrue); 538 } 539 virtual int Opcode() const; 540 541 protected: 542 virtual bool always_taken(const TypeTuple* t) const { return t == TypeTuple::IFTRUE; } 543 }; 544 545 class IfFalseNode : public IfProjNode { 546 public: 547 IfFalseNode( IfNode *ifnode ) : IfProjNode(ifnode,0) { 548 init_class_id(Class_IfFalse); 549 } 550 virtual int Opcode() const; 551 552 protected: 553 virtual bool always_taken(const TypeTuple* t) const { return t == TypeTuple::IFFALSE; } 554 }; 555 556 557 //------------------------------PCTableNode------------------------------------ 558 // Build an indirect branch table. Given a control and a table index, 559 // control is passed to the Projection matching the table index. Used to 560 // implement switch statements and exception-handling capabilities. 561 // Undefined behavior if passed-in index is not inside the table. 562 class PCTableNode : public MultiBranchNode { 563 virtual uint hash() const; // Target count; table size 564 virtual bool cmp( const Node &n ) const; 565 virtual uint size_of() const { return sizeof(*this); } 566 567 public: 568 const uint _size; // Number of targets 569 570 PCTableNode( Node *ctrl, Node *idx, uint size ) : MultiBranchNode(2), _size(size) { 571 init_class_id(Class_PCTable); 572 init_req(0, ctrl); 573 init_req(1, idx); 574 } 575 virtual int Opcode() const; 576 virtual const Type* Value(PhaseGVN* phase) const; 577 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape); 578 virtual const Type *bottom_type() const; 579 virtual bool pinned() const { return true; } 580 virtual int required_outcnt() const { return _size; } 581 }; 582 583 //------------------------------JumpNode--------------------------------------- 584 // Indirect branch. Uses PCTable above to implement a switch statement. 585 // It emits as a table load and local branch. 586 class JumpNode : public PCTableNode { 587 virtual uint size_of() const { return sizeof(*this); } 588 public: 589 float* _probs; // probability of each projection 590 float _fcnt; // total number of times this Jump was executed 591 JumpNode( Node* control, Node* switch_val, uint size, float* probs, float cnt) 592 : PCTableNode(control, switch_val, size), 593 _probs(probs), _fcnt(cnt) { 594 init_class_id(Class_Jump); 595 } 596 virtual int Opcode() const; 597 virtual const RegMask& out_RegMask() const; 598 virtual const Node* is_block_proj() const { return this; } 599 }; 600 601 class JumpProjNode : public JProjNode { 602 virtual uint hash() const; 603 virtual bool cmp( const Node &n ) const; 604 virtual uint size_of() const { return sizeof(*this); } 605 606 private: 607 const int _dest_bci; 608 const uint _proj_no; 609 const int _switch_val; 610 public: 611 JumpProjNode(Node* jumpnode, uint proj_no, int dest_bci, int switch_val) 612 : JProjNode(jumpnode, proj_no), _dest_bci(dest_bci), _proj_no(proj_no), _switch_val(switch_val) { 613 init_class_id(Class_JumpProj); 614 } 615 616 virtual int Opcode() const; 617 virtual const Type* bottom_type() const { return Type::CONTROL; } 618 int dest_bci() const { return _dest_bci; } 619 int switch_val() const { return _switch_val; } 620 uint proj_no() const { return _proj_no; } 621 #ifndef PRODUCT 622 virtual void dump_spec(outputStream *st) const; 623 virtual void dump_compact_spec(outputStream *st) const; 624 #endif 625 }; 626 627 //------------------------------CatchNode-------------------------------------- 628 // Helper node to fork exceptions. "Catch" catches any exceptions thrown by 629 // a just-prior call. Looks like a PCTableNode but emits no code - just the 630 // table. The table lookup and branch is implemented by RethrowNode. 631 class CatchNode : public PCTableNode { 632 public: 633 CatchNode( Node *ctrl, Node *idx, uint size ) : PCTableNode(ctrl,idx,size){ 634 init_class_id(Class_Catch); 635 } 636 virtual int Opcode() const; 637 virtual const Type* Value(PhaseGVN* phase) const; 638 }; 639 640 // CatchProjNode controls which exception handler is targeted after a call. 641 // It is passed in the bci of the target handler, or no_handler_bci in case 642 // the projection doesn't lead to an exception handler. 643 class CatchProjNode : public CProjNode { 644 virtual uint hash() const; 645 virtual bool cmp( const Node &n ) const; 646 virtual uint size_of() const { return sizeof(*this); } 647 648 private: 649 const int _handler_bci; 650 651 public: 652 enum { 653 fall_through_index = 0, // the fall through projection index 654 catch_all_index = 1, // the projection index for catch-alls 655 no_handler_bci = -1 // the bci for fall through or catch-all projs 656 }; 657 658 CatchProjNode(Node* catchnode, uint proj_no, int handler_bci) 659 : CProjNode(catchnode, proj_no), _handler_bci(handler_bci) { 660 init_class_id(Class_CatchProj); 661 assert(proj_no != fall_through_index || handler_bci < 0, "fall through case must have bci < 0"); 662 } 663 664 virtual int Opcode() const; 665 virtual Node* Identity(PhaseGVN* phase); 666 virtual const Type *bottom_type() const { return Type::CONTROL; } 667 int handler_bci() const { return _handler_bci; } 668 bool is_handler_proj() const { return _handler_bci >= 0; } 669 #ifndef PRODUCT 670 virtual void dump_spec(outputStream *st) const; 671 #endif 672 }; 673 674 675 //---------------------------------CreateExNode-------------------------------- 676 // Helper node to create the exception coming back from a call 677 class CreateExNode : public TypeNode { 678 public: 679 CreateExNode(const Type* t, Node* control, Node* i_o) : TypeNode(t, 2) { 680 init_req(0, control); 681 init_req(1, i_o); 682 } 683 virtual int Opcode() const; 684 virtual Node* Identity(PhaseGVN* phase); 685 virtual bool pinned() const { return true; } 686 uint match_edge(uint idx) const { return 0; } 687 virtual uint ideal_reg() const { return Op_RegP; } 688 }; 689 690 //------------------------------NeverBranchNode------------------------------- 691 // The never-taken branch. Used to give the appearance of exiting infinite 692 // loops to those algorithms that like all paths to be reachable. Encodes 693 // empty. 694 class NeverBranchNode : public MultiBranchNode { 695 public: 696 NeverBranchNode(Node* ctrl) : MultiBranchNode(1) { 697 init_req(0, ctrl); 698 init_class_id(Class_NeverBranch); 699 } 700 virtual int Opcode() const; 701 virtual bool pinned() const { return true; }; 702 virtual const Type *bottom_type() const { return TypeTuple::IFBOTH; } 703 virtual const Type* Value(PhaseGVN* phase) const; 704 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape); 705 virtual int required_outcnt() const { return 2; } 706 virtual void emit(C2_MacroAssembler *masm, PhaseRegAlloc *ra_) const { } 707 virtual uint size(PhaseRegAlloc *ra_) const { return 0; } 708 #ifndef PRODUCT 709 virtual void format( PhaseRegAlloc *, outputStream *st ) const; 710 #endif 711 }; 712 713 //------------------------------BlackholeNode---------------------------- 714 // Blackhole all arguments. This node would survive through the compiler 715 // the effects on its arguments, and would be finally matched to nothing. 716 class BlackholeNode : public MultiNode { 717 public: 718 BlackholeNode(Node* ctrl) : MultiNode(1) { 719 init_req(TypeFunc::Control, ctrl); 720 init_class_id(Class_Blackhole); 721 } 722 virtual int Opcode() const; 723 virtual uint ideal_reg() const { return 0; } // not matched in the AD file 724 virtual const Type* bottom_type() const { return TypeTuple::MEMBAR; } 725 726 const RegMask &in_RegMask(uint idx) const { 727 // Fake the incoming arguments mask for blackholes: accept all registers 728 // and all stack slots. This would avoid any redundant register moves 729 // for blackhole inputs. 730 return RegMask::All; 731 } 732 #ifndef PRODUCT 733 virtual void format(PhaseRegAlloc* ra, outputStream* st) const; 734 #endif 735 }; 736 737 738 #endif // SHARE_OPTO_CFGNODE_HPP