1/* 2 * Copyright (c) 1997, 2015, 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_VM_OPTO_CFGNODE_HPP 26#define SHARE_VM_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 37class Matcher; 38class Node; 39class RegionNode; 40class TypeNode; 41class PhiNode; 42class GotoNode; 43class MultiNode; 44class MultiBranchNode; 45class IfNode; 46class PCTableNode; 47class JumpNode; 48class CatchNode; 49class NeverBranchNode; 50class ProjNode; 51class CProjNode; 52class IfTrueNode; 53class IfFalseNode; 54class CatchProjNode; 55class JProjNode; 56class JumpProjNode; 57class SCMemProjNode; 58class PhaseIdealLoop; 59 60//------------------------------RegionNode------------------------------------- 61// The class of RegionNodes, which can be mapped to basic blocks in the 62// program. Their inputs point to Control sources. PhiNodes (described 63// below) have an input point to a RegionNode. Merged data inputs to PhiNodes 64// correspond 1-to-1 with RegionNode inputs. The zero input of a PhiNode is 65// the RegionNode, and the zero input of the RegionNode is itself. 66class RegionNode : public Node { 67public: 68 // Node layout (parallels PhiNode): 69 enum { Region, // Generally points to self. 70 Control // Control arcs are [1..len) 71 }; 72 73 RegionNode( uint required ) : Node(required) { 74 init_class_id(Class_Region); 75 init_req(0,this); 76 } 77 78 Node* is_copy() const { 79 const Node* r = _in[Region]; 80 if (r == NULL) 81 return nonnull_req(); 82 return NULL; // not a copy! 83 } 84 PhiNode* has_phi() const; // returns an arbitrary phi user, or NULL 85 PhiNode* has_unique_phi() const; // returns the unique phi user, or NULL 86 // Is this region node unreachable from root? 87 bool is_unreachable_region(PhaseGVN *phase) const; 88 virtual int Opcode() const; 89 virtual bool pinned() const { return (const Node *)in(0) == this; } 90 virtual bool is_CFG () const { return true; } 91 virtual uint hash() const { return NO_HASH; } // CFG nodes do not hash 92 virtual bool depends_only_on_test() const { return false; } 93 virtual const Type *bottom_type() const { return Type::CONTROL; } 94 virtual const Type* Value(PhaseGVN* phase) const; 95 virtual Node* Identity(PhaseGVN* phase); 96 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape); 97 virtual const RegMask &out_RegMask() const; 98 bool try_clean_mem_phi(PhaseGVN *phase); 99}; 100 101//------------------------------JProjNode-------------------------------------- 102// jump projection for node that produces multiple control-flow paths 103class JProjNode : public ProjNode { 104 public: 105 JProjNode( Node* ctrl, uint idx ) : ProjNode(ctrl,idx) {} 106 virtual int Opcode() const; 107 virtual bool is_CFG() const { return true; } 108 virtual uint hash() const { return NO_HASH; } // CFG nodes do not hash 109 virtual const Node* is_block_proj() const { return in(0); } 110 virtual const RegMask& out_RegMask() const; 111 virtual uint ideal_reg() const { return 0; } 112}; 113 114//------------------------------PhiNode---------------------------------------- 115// PhiNodes merge values from different Control paths. Slot 0 points to the 116// controlling RegionNode. Other slots map 1-for-1 with incoming control flow 117// paths to the RegionNode. For speed reasons (to avoid another pass) we 118// can turn PhiNodes into copys in-place by NULL'ing out their RegionNode 119// input in slot 0. 120class PhiNode : public TypeNode { 121 const TypePtr* const _adr_type; // non-null only for Type::MEMORY nodes. 122 // The following fields are only used for data PhiNodes to indicate 123 // that the PhiNode represents the value of a known instance field. 124 int _inst_mem_id; // Instance memory id (node index of the memory Phi) 125 const int _inst_id; // Instance id of the memory slice. 126 const int _inst_index; // Alias index of the instance memory slice. 127 // Array elements references have the same alias_idx but different offset. 128 const int _inst_offset; // Offset of the instance memory slice. 129 // Size is bigger to hold the _adr_type field. 130 virtual uint hash() const; // Check the type 131 virtual uint cmp( const Node &n ) const; 132 virtual uint size_of() const { return sizeof(*this); } 133 134 // Determine if CMoveNode::is_cmove_id can be used at this join point. 135 Node* is_cmove_id(PhaseTransform* phase, int true_path); 136 137public: 138 // Node layout (parallels RegionNode): 139 enum { Region, // Control input is the Phi's region. 140 Input // Input values are [1..len) 141 }; 142 143 PhiNode( Node *r, const Type *t, const TypePtr* at = NULL, 144 const int imid = -1, 145 const int iid = TypeOopPtr::InstanceTop, 146 const int iidx = Compile::AliasIdxTop, 147 const int ioffs = Type::OffsetTop ) 148 : TypeNode(t,r->req()), 149 _adr_type(at), 150 _inst_mem_id(imid), 151 _inst_id(iid), 152 _inst_index(iidx), 153 _inst_offset(ioffs) 154 { 155 init_class_id(Class_Phi); 156 init_req(0, r); 157 verify_adr_type(); 158 } 159 // create a new phi with in edges matching r and set (initially) to x 160 static PhiNode* make( Node* r, Node* x ); 161 // extra type arguments override the new phi's bottom_type and adr_type 162 static PhiNode* make( Node* r, Node* x, const Type *t, const TypePtr* at = NULL ); 163 // create a new phi with narrowed memory type 164 PhiNode* slice_memory(const TypePtr* adr_type) const; 165 PhiNode* split_out_instance(const TypePtr* at, PhaseIterGVN *igvn) const; 166 // like make(r, x), but does not initialize the in edges to x 167 static PhiNode* make_blank( Node* r, Node* x ); 168 169 // Accessors 170 RegionNode* region() const { Node* r = in(Region); assert(!r || r->is_Region(), ""); return (RegionNode*)r; } 171 172 Node* is_copy() const { 173 // The node is a real phi if _in[0] is a Region node. 174 DEBUG_ONLY(const Node* r = _in[Region];) 175 assert(r != NULL && r->is_Region(), "Not valid control"); 176 return NULL; // not a copy! 177 } 178 179 bool is_tripcount() const; 180 181 // Determine a unique non-trivial input, if any. 182 // Ignore casts if it helps. Return NULL on failure. 183 Node* unique_input(PhaseTransform *phase, bool uncast); 184 Node* unique_input(PhaseTransform *phase) { 185 Node* uin = unique_input(phase, false); 186 if (uin == NULL) { 187 uin = unique_input(phase, true); 188 } 189 return uin; 190 } 191 192 // Check for a simple dead loop. 193 enum LoopSafety { Safe = 0, Unsafe, UnsafeLoop }; 194 LoopSafety simple_data_loop_check(Node *in) const; 195 // Is it unsafe data loop? It becomes a dead loop if this phi node removed. 196 bool is_unsafe_data_reference(Node *in) const; 197 int is_diamond_phi(bool check_control_only = false) const; 198 virtual int Opcode() const; 199 virtual bool pinned() const { return in(0) != 0; } 200 virtual const TypePtr *adr_type() const { verify_adr_type(true); return _adr_type; } 201 202 void set_inst_mem_id(int inst_mem_id) { _inst_mem_id = inst_mem_id; } 203 const int inst_mem_id() const { return _inst_mem_id; } 204 const int inst_id() const { return _inst_id; } 205 const int inst_index() const { return _inst_index; } 206 const int inst_offset() const { return _inst_offset; } 207 bool is_same_inst_field(const Type* tp, int mem_id, int id, int index, int offset) { 208 return type()->basic_type() == tp->basic_type() && 209 inst_mem_id() == mem_id && 210 inst_id() == id && 211 inst_index() == index && 212 inst_offset() == offset && 213 type()->higher_equal(tp); 214 } 215 216 virtual const Type* Value(PhaseGVN* phase) const; 217 virtual Node* Identity(PhaseGVN* phase); 218 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape); 219 virtual const RegMask &out_RegMask() const; 220 virtual const RegMask &in_RegMask(uint) const; 221#ifndef PRODUCT 222 virtual void related(GrowableArray<Node*> *in_rel, GrowableArray<Node*> *out_rel, bool compact) const; 223 virtual void dump_spec(outputStream *st) const; 224#endif 225#ifdef ASSERT 226 void verify_adr_type(VectorSet& visited, const TypePtr* at) const; 227 void verify_adr_type(bool recursive = false) const; 228#else //ASSERT 229 void verify_adr_type(bool recursive = false) const {} 230#endif //ASSERT 231}; 232 233//------------------------------GotoNode--------------------------------------- 234// GotoNodes perform direct branches. 235class GotoNode : public Node { 236public: 237 GotoNode( Node *control ) : Node(control) {} 238 virtual int Opcode() const; 239 virtual bool pinned() const { return true; } 240 virtual bool is_CFG() const { return true; } 241 virtual uint hash() const { return NO_HASH; } // CFG nodes do not hash 242 virtual const Node *is_block_proj() const { return this; } 243 virtual bool depends_only_on_test() const { return false; } 244 virtual const Type *bottom_type() const { return Type::CONTROL; } 245 virtual const Type* Value(PhaseGVN* phase) const; 246 virtual Node* Identity(PhaseGVN* phase); 247 virtual const RegMask &out_RegMask() const; 248 249#ifndef PRODUCT 250 virtual void related(GrowableArray<Node*> *in_rel, GrowableArray<Node*> *out_rel, bool compact) const; 251#endif 252}; 253 254//------------------------------CProjNode-------------------------------------- 255// control projection for node that produces multiple control-flow paths 256class CProjNode : public ProjNode { 257public: 258 CProjNode( Node *ctrl, uint idx ) : ProjNode(ctrl,idx) {} 259 virtual int Opcode() const; 260 virtual bool is_CFG() const { return true; } 261 virtual uint hash() const { return NO_HASH; } // CFG nodes do not hash 262 virtual const Node *is_block_proj() const { return in(0); } 263 virtual const RegMask &out_RegMask() const; 264 virtual uint ideal_reg() const { return 0; } 265}; 266 267//---------------------------MultiBranchNode----------------------------------- 268// This class defines a MultiBranchNode, a MultiNode which yields multiple 269// control values. These are distinguished from other types of MultiNodes 270// which yield multiple values, but control is always and only projection #0. 271class MultiBranchNode : public MultiNode { 272public: 273 MultiBranchNode( uint required ) : MultiNode(required) { 274 init_class_id(Class_MultiBranch); 275 } 276 // returns required number of users to be well formed. 277 virtual int required_outcnt() const = 0; 278}; 279 280//------------------------------IfNode----------------------------------------- 281// Output selected Control, based on a boolean test 282class IfNode : public MultiBranchNode { 283 // Size is bigger to hold the probability field. However, _prob does not 284 // change the semantics so it does not appear in the hash & cmp functions. 285 virtual uint size_of() const { return sizeof(*this); } 286 287private: 288 // Helper methods for fold_compares 289 bool cmpi_folds(PhaseIterGVN* igvn); 290 bool is_ctrl_folds(Node* ctrl, PhaseIterGVN* igvn); 291 bool has_shared_region(ProjNode* proj, ProjNode*& success, ProjNode*& fail); 292 bool has_only_uncommon_traps(ProjNode* proj, ProjNode*& success, ProjNode*& fail, PhaseIterGVN* igvn); 293 Node* merge_uncommon_traps(ProjNode* proj, ProjNode* success, ProjNode* fail, PhaseIterGVN* igvn); 294 static void improve_address_types(Node* l, Node* r, ProjNode* fail, PhaseIterGVN* igvn); 295 bool is_cmp_with_loadrange(ProjNode* proj); 296 bool is_null_check(ProjNode* proj, PhaseIterGVN* igvn); 297 bool is_side_effect_free_test(ProjNode* proj, PhaseIterGVN* igvn); 298 void reroute_side_effect_free_unc(ProjNode* proj, ProjNode* dom_proj, PhaseIterGVN* igvn); 299 ProjNode* uncommon_trap_proj(CallStaticJavaNode*& call) const; 300 bool fold_compares_helper(ProjNode* proj, ProjNode* success, ProjNode* fail, PhaseIterGVN* igvn); 301 302protected: 303 ProjNode* range_check_trap_proj(int& flip, Node*& l, Node*& r); 304 Node* Ideal_common(PhaseGVN *phase, bool can_reshape); 305 Node* dominated_by(Node* prev_dom, PhaseIterGVN* igvn); 306 Node* search_identical(int dist); 307 308public: 309 310 // Degrees of branch prediction probability by order of magnitude: 311 // PROB_UNLIKELY_1e(N) is a 1 in 1eN chance. 312 // PROB_LIKELY_1e(N) is a 1 - PROB_UNLIKELY_1e(N) 313#define PROB_UNLIKELY_MAG(N) (1e- ## N ## f) 314#define PROB_LIKELY_MAG(N) (1.0f-PROB_UNLIKELY_MAG(N)) 315 316 // Maximum and minimum branch prediction probabilties 317 // 1 in 1,000,000 (magnitude 6) 318 // 319 // Although PROB_NEVER == PROB_MIN and PROB_ALWAYS == PROB_MAX 320 // they are used to distinguish different situations: 321 // 322 // The name PROB_MAX (PROB_MIN) is for probabilities which correspond to 323 // very likely (unlikely) but with a concrete possibility of a rare 324 // contrary case. These constants would be used for pinning 325 // measurements, and as measures for assertions that have high 326 // confidence, but some evidence of occasional failure. 327 // 328 // The name PROB_ALWAYS (PROB_NEVER) is to stand for situations for which 329 // there is no evidence at all that the contrary case has ever occurred. 330 331#define PROB_NEVER PROB_UNLIKELY_MAG(6) 332#define PROB_ALWAYS PROB_LIKELY_MAG(6) 333 334#define PROB_MIN PROB_UNLIKELY_MAG(6) 335#define PROB_MAX PROB_LIKELY_MAG(6) 336 337 // Static branch prediction probabilities 338 // 1 in 10 (magnitude 1) 339#define PROB_STATIC_INFREQUENT PROB_UNLIKELY_MAG(1) 340#define PROB_STATIC_FREQUENT PROB_LIKELY_MAG(1) 341 342 // Fair probability 50/50 343#define PROB_FAIR (0.5f) 344 345 // Unknown probability sentinel 346#define PROB_UNKNOWN (-1.0f) 347 348 // Probability "constructors", to distinguish as a probability any manifest 349 // constant without a names 350#define PROB_LIKELY(x) ((float) (x)) 351#define PROB_UNLIKELY(x) (1.0f - (float)(x)) 352 353 // Other probabilities in use, but without a unique name, are documented 354 // here for lack of a better place: 355 // 356 // 1 in 1000 probabilities (magnitude 3): 357 // threshold for converting to conditional move 358 // likelihood of null check failure if a null HAS been seen before 359 // likelihood of slow path taken in library calls 360 // 361 // 1 in 10,000 probabilities (magnitude 4): 362 // threshold for making an uncommon trap probability more extreme 363 // threshold for for making a null check implicit 364 // likelihood of needing a gc if eden top moves during an allocation 365 // likelihood of a predicted call failure 366 // 367 // 1 in 100,000 probabilities (magnitude 5): 368 // threshold for ignoring counts when estimating path frequency 369 // likelihood of FP clipping failure 370 // likelihood of catching an exception from a try block 371 // likelihood of null check failure if a null has NOT been seen before 372 // 373 // Magic manifest probabilities such as 0.83, 0.7, ... can be found in 374 // gen_subtype_check() and catch_inline_exceptions(). 375 376 float _prob; // Probability of true path being taken. 377 float _fcnt; // Frequency counter 378 IfNode( Node *control, Node *b, float p, float fcnt ) 379 : MultiBranchNode(2), _prob(p), _fcnt(fcnt) { 380 init_class_id(Class_If); 381 init_req(0,control); 382 init_req(1,b); 383 } 384 virtual int Opcode() const; 385 virtual bool pinned() const { return true; } 386 virtual const Type *bottom_type() const { return TypeTuple::IFBOTH; } 387 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape); 388 virtual const Type* Value(PhaseGVN* phase) const; 389 virtual int required_outcnt() const { return 2; } 390 virtual const RegMask &out_RegMask() const; 391 Node* fold_compares(PhaseIterGVN* phase); 392 static Node* up_one_dom(Node* curr, bool linear_only = false); 393 394 // Takes the type of val and filters it through the test represented 395 // by if_proj and returns a more refined type if one is produced. 396 // Returns NULL is it couldn't improve the type. 397 static const TypeInt* filtered_int_type(PhaseGVN* phase, Node* val, Node* if_proj); 398 399#ifndef PRODUCT 400 virtual void dump_spec(outputStream *st) const; 401 virtual void related(GrowableArray <Node *> *in_rel, GrowableArray <Node *> *out_rel, bool compact) const; 402#endif 403}; 404 405class RangeCheckNode : public IfNode { 406private: 407 int is_range_check(Node* &range, Node* &index, jint &offset); 408 409public: 410 RangeCheckNode(Node* control, Node *b, float p, float fcnt) 411 : IfNode(control, b, p, fcnt) { 412 init_class_id(Class_RangeCheck); 413 } 414 415 virtual int Opcode() const; 416 virtual Node* Ideal(PhaseGVN *phase, bool can_reshape); 417}; 418 419class IfProjNode : public CProjNode { 420public: 421 IfProjNode(IfNode *ifnode, uint idx) : CProjNode(ifnode,idx) {} 422 virtual Node* Identity(PhaseGVN* phase); 423 424protected: 425 // Type of If input when this branch is always taken 426 virtual bool always_taken(const TypeTuple* t) const = 0; 427 428#ifndef PRODUCT 429public: 430 virtual void related(GrowableArray<Node*> *in_rel, GrowableArray<Node*> *out_rel, bool compact) const; 431#endif 432}; 433 434class IfTrueNode : public IfProjNode { 435public: 436 IfTrueNode( IfNode *ifnode ) : IfProjNode(ifnode,1) { 437 init_class_id(Class_IfTrue); 438 } 439 virtual int Opcode() const; 440 441protected: 442 virtual bool always_taken(const TypeTuple* t) const { return t == TypeTuple::IFTRUE; } 443}; 444 445class IfFalseNode : public IfProjNode { 446public: 447 IfFalseNode( IfNode *ifnode ) : IfProjNode(ifnode,0) { 448 init_class_id(Class_IfFalse); 449 } 450 virtual int Opcode() const; 451 452protected: 453 virtual bool always_taken(const TypeTuple* t) const { return t == TypeTuple::IFFALSE; } 454}; 455 456 457//------------------------------PCTableNode------------------------------------ 458// Build an indirect branch table. Given a control and a table index, 459// control is passed to the Projection matching the table index. Used to 460// implement switch statements and exception-handling capabilities. 461// Undefined behavior if passed-in index is not inside the table. 462class PCTableNode : public MultiBranchNode { 463 virtual uint hash() const; // Target count; table size 464 virtual uint cmp( const Node &n ) const; 465 virtual uint size_of() const { return sizeof(*this); } 466 467public: 468 const uint _size; // Number of targets 469 470 PCTableNode( Node *ctrl, Node *idx, uint size ) : MultiBranchNode(2), _size(size) { 471 init_class_id(Class_PCTable); 472 init_req(0, ctrl); 473 init_req(1, idx); 474 } 475 virtual int Opcode() const; 476 virtual const Type* Value(PhaseGVN* phase) const; 477 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape); 478 virtual const Type *bottom_type() const; 479 virtual bool pinned() const { return true; } 480 virtual int required_outcnt() const { return _size; } 481}; 482 483//------------------------------JumpNode--------------------------------------- 484// Indirect branch. Uses PCTable above to implement a switch statement. 485// It emits as a table load and local branch. 486class JumpNode : public PCTableNode { 487public: 488 JumpNode( Node* control, Node* switch_val, uint size) : PCTableNode(control, switch_val, size) { 489 init_class_id(Class_Jump); 490 } 491 virtual int Opcode() const; 492 virtual const RegMask& out_RegMask() const; 493 virtual const Node* is_block_proj() const { return this; } 494#ifndef PRODUCT 495 virtual void related(GrowableArray<Node*> *in_rel, GrowableArray<Node*> *out_rel, bool compact) const; 496#endif 497}; 498 499class JumpProjNode : public JProjNode { 500 virtual uint hash() const; 501 virtual uint cmp( const Node &n ) const; 502 virtual uint size_of() const { return sizeof(*this); } 503 504 private: 505 const int _dest_bci; 506 const uint _proj_no; 507 const int _switch_val; 508 public: 509 JumpProjNode(Node* jumpnode, uint proj_no, int dest_bci, int switch_val) 510 : JProjNode(jumpnode, proj_no), _dest_bci(dest_bci), _proj_no(proj_no), _switch_val(switch_val) { 511 init_class_id(Class_JumpProj); 512 } 513 514 virtual int Opcode() const; 515 virtual const Type* bottom_type() const { return Type::CONTROL; } 516 int dest_bci() const { return _dest_bci; } 517 int switch_val() const { return _switch_val; } 518 uint proj_no() const { return _proj_no; } 519#ifndef PRODUCT 520 virtual void dump_spec(outputStream *st) const; 521 virtual void dump_compact_spec(outputStream *st) const; 522 virtual void related(GrowableArray<Node*> *in_rel, GrowableArray<Node*> *out_rel, bool compact) const; 523#endif 524}; 525 526//------------------------------CatchNode-------------------------------------- 527// Helper node to fork exceptions. "Catch" catches any exceptions thrown by 528// a just-prior call. Looks like a PCTableNode but emits no code - just the 529// table. The table lookup and branch is implemented by RethrowNode. 530class CatchNode : public PCTableNode { 531public: 532 CatchNode( Node *ctrl, Node *idx, uint size ) : PCTableNode(ctrl,idx,size){ 533 init_class_id(Class_Catch); 534 } 535 virtual int Opcode() const; 536 virtual const Type* Value(PhaseGVN* phase) const; 537}; 538 539// CatchProjNode controls which exception handler is targetted after a call. 540// It is passed in the bci of the target handler, or no_handler_bci in case 541// the projection doesn't lead to an exception handler. 542class CatchProjNode : public CProjNode { 543 virtual uint hash() const; 544 virtual uint cmp( const Node &n ) const; 545 virtual uint size_of() const { return sizeof(*this); } 546 547private: 548 const int _handler_bci; 549 550public: 551 enum { 552 fall_through_index = 0, // the fall through projection index 553 catch_all_index = 1, // the projection index for catch-alls 554 no_handler_bci = -1 // the bci for fall through or catch-all projs 555 }; 556 557 CatchProjNode(Node* catchnode, uint proj_no, int handler_bci) 558 : CProjNode(catchnode, proj_no), _handler_bci(handler_bci) { 559 init_class_id(Class_CatchProj); 560 assert(proj_no != fall_through_index || handler_bci < 0, "fall through case must have bci < 0"); 561 } 562 563 virtual int Opcode() const; 564 virtual Node* Identity(PhaseGVN* phase); 565 virtual const Type *bottom_type() const { return Type::CONTROL; } 566 int handler_bci() const { return _handler_bci; } 567 bool is_handler_proj() const { return _handler_bci >= 0; } 568#ifndef PRODUCT 569 virtual void dump_spec(outputStream *st) const; 570#endif 571}; 572 573 574//---------------------------------CreateExNode-------------------------------- 575// Helper node to create the exception coming back from a call 576class CreateExNode : public TypeNode { 577public: 578 CreateExNode(const Type* t, Node* control, Node* i_o) : TypeNode(t, 2) { 579 init_req(0, control); 580 init_req(1, i_o); 581 } 582 virtual int Opcode() const; 583 virtual Node* Identity(PhaseGVN* phase); 584 virtual bool pinned() const { return true; } 585 uint match_edge(uint idx) const { return 0; } 586 virtual uint ideal_reg() const { return Op_RegP; } 587}; 588 589//------------------------------NeverBranchNode------------------------------- 590// The never-taken branch. Used to give the appearance of exiting infinite 591// loops to those algorithms that like all paths to be reachable. Encodes 592// empty. 593class NeverBranchNode : public MultiBranchNode { 594public: 595 NeverBranchNode( Node *ctrl ) : MultiBranchNode(1) { init_req(0,ctrl); } 596 virtual int Opcode() const; 597 virtual bool pinned() const { return true; }; 598 virtual const Type *bottom_type() const { return TypeTuple::IFBOTH; } 599 virtual const Type* Value(PhaseGVN* phase) const; 600 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape); 601 virtual int required_outcnt() const { return 2; } 602 virtual void emit(CodeBuffer &cbuf, PhaseRegAlloc *ra_) const { } 603 virtual uint size(PhaseRegAlloc *ra_) const { return 0; } 604#ifndef PRODUCT 605 virtual void format( PhaseRegAlloc *, outputStream *st ) const; 606#endif 607}; 608 609#endif // SHARE_VM_OPTO_CFGNODE_HPP 610