1 /*
   2  * Copyright (c) 1997, 2025, 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_CALLNODE_HPP
  26 #define SHARE_OPTO_CALLNODE_HPP
  27 
  28 #include "opto/connode.hpp"
  29 #include "opto/mulnode.hpp"
  30 #include "opto/multnode.hpp"
  31 #include "opto/opcodes.hpp"
  32 #include "opto/phaseX.hpp"
  33 #include "opto/replacednodes.hpp"
  34 #include "opto/type.hpp"
  35 #include "utilities/growableArray.hpp"
  36 
  37 // Portions of code courtesy of Clifford Click
  38 
  39 // Optimization - Graph Style
  40 
  41 class NamedCounter;
  42 class MultiNode;
  43 class  SafePointNode;
  44 class   CallNode;
  45 class     CallJavaNode;
  46 class       CallStaticJavaNode;
  47 class       CallDynamicJavaNode;
  48 class     CallRuntimeNode;
  49 class       CallLeafNode;
  50 class         CallLeafNoFPNode;
  51 class         CallLeafVectorNode;
  52 class     AllocateNode;
  53 class       AllocateArrayNode;
  54 class     AbstractLockNode;
  55 class       LockNode;
  56 class       UnlockNode;
  57 class FastLockNode;
  58 
  59 //------------------------------StartNode--------------------------------------
  60 // The method start node
  61 class StartNode : public MultiNode {
  62   virtual bool cmp( const Node &n ) const;
  63   virtual uint size_of() const; // Size is bigger
  64 public:
  65   const TypeTuple *_domain;
  66   StartNode( Node *root, const TypeTuple *domain ) : MultiNode(2), _domain(domain) {
  67     init_class_id(Class_Start);
  68     init_req(0,this);
  69     init_req(1,root);
  70   }
  71   virtual int Opcode() const;
  72   virtual bool pinned() const { return true; };
  73   virtual const Type *bottom_type() const;
  74   virtual const TypePtr *adr_type() const { return TypePtr::BOTTOM; }
  75   virtual const Type* Value(PhaseGVN* phase) const;
  76   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
  77   virtual void  calling_convention( BasicType* sig_bt, VMRegPair *parm_reg, uint length ) const;
  78   virtual const RegMask &in_RegMask(uint) const;
  79   virtual Node *match(const ProjNode *proj, const Matcher *m, const RegMask* mask);
  80   virtual uint ideal_reg() const { return 0; }
  81 #ifndef PRODUCT
  82   virtual void  dump_spec(outputStream *st) const;
  83   virtual void  dump_compact_spec(outputStream *st) const;
  84 #endif
  85 };
  86 
  87 //------------------------------StartOSRNode-----------------------------------
  88 // The method start node for on stack replacement code
  89 class StartOSRNode : public StartNode {
  90 public:
  91   StartOSRNode( Node *root, const TypeTuple *domain ) : StartNode(root, domain) {}
  92   virtual int   Opcode() const;
  93 };
  94 
  95 
  96 //------------------------------ParmNode---------------------------------------
  97 // Incoming parameters
  98 class ParmNode : public ProjNode {
  99   static const char * const names[TypeFunc::Parms+1];
 100 public:
 101   ParmNode( StartNode *src, uint con ) : ProjNode(src,con) {
 102     init_class_id(Class_Parm);
 103   }
 104   virtual int Opcode() const;
 105   virtual bool  is_CFG() const { return (_con == TypeFunc::Control); }
 106   virtual uint ideal_reg() const;
 107 #ifndef PRODUCT
 108   virtual void dump_spec(outputStream *st) const;
 109   virtual void dump_compact_spec(outputStream *st) const;
 110 #endif
 111 };
 112 
 113 
 114 //------------------------------ReturnNode-------------------------------------
 115 // Return from subroutine node
 116 class ReturnNode : public Node {
 117 public:
 118   ReturnNode( uint edges, Node *cntrl, Node *i_o, Node *memory, Node *retadr, Node *frameptr );
 119   virtual int Opcode() const;
 120   virtual bool  is_CFG() const { return true; }
 121   virtual uint hash() const { return NO_HASH; }  // CFG nodes do not hash
 122   virtual bool depends_only_on_test() const { return false; }
 123   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
 124   virtual const Type* Value(PhaseGVN* phase) const;
 125   virtual uint ideal_reg() const { return NotAMachineReg; }
 126   virtual uint match_edge(uint idx) const;
 127 #ifndef PRODUCT
 128   virtual void dump_req(outputStream *st = tty, DumpConfig* dc = nullptr) const;
 129 #endif
 130 };
 131 
 132 
 133 //------------------------------RethrowNode------------------------------------
 134 // Rethrow of exception at call site.  Ends a procedure before rethrowing;
 135 // ends the current basic block like a ReturnNode.  Restores registers and
 136 // unwinds stack.  Rethrow happens in the caller's method.
 137 class RethrowNode : public Node {
 138  public:
 139   RethrowNode( Node *cntrl, Node *i_o, Node *memory, Node *frameptr, Node *ret_adr, Node *exception );
 140   virtual int Opcode() const;
 141   virtual bool  is_CFG() const { return true; }
 142   virtual uint hash() const { return NO_HASH; }  // CFG nodes do not hash
 143   virtual bool depends_only_on_test() const { return false; }
 144   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
 145   virtual const Type* Value(PhaseGVN* phase) const;
 146   virtual uint match_edge(uint idx) const;
 147   virtual uint ideal_reg() const { return NotAMachineReg; }
 148 #ifndef PRODUCT
 149   virtual void dump_req(outputStream *st = tty, DumpConfig* dc = nullptr) const;
 150 #endif
 151 };
 152 
 153 
 154 //------------------------------ForwardExceptionNode---------------------------
 155 // Pop stack frame and jump to StubRoutines::forward_exception_entry()
 156 class ForwardExceptionNode : public ReturnNode {
 157 public:
 158   ForwardExceptionNode(Node* cntrl, Node* i_o, Node* memory, Node* frameptr, Node* retadr)
 159     : ReturnNode(TypeFunc::Parms, cntrl, i_o, memory, frameptr, retadr) {
 160   }
 161 
 162   virtual int Opcode() const;
 163 };
 164 
 165 //------------------------------TailCallNode-----------------------------------
 166 // Pop stack frame and jump indirect
 167 class TailCallNode : public ReturnNode {
 168 public:
 169   TailCallNode( Node *cntrl, Node *i_o, Node *memory, Node *frameptr, Node *retadr, Node *target, Node *moop )
 170     : ReturnNode( TypeFunc::Parms+2, cntrl, i_o, memory, frameptr, retadr ) {
 171     init_req(TypeFunc::Parms, target);
 172     init_req(TypeFunc::Parms+1, moop);
 173   }
 174 
 175   virtual int Opcode() const;
 176   virtual uint match_edge(uint idx) const;
 177 };
 178 
 179 //------------------------------TailJumpNode-----------------------------------
 180 // Pop stack frame and jump indirect
 181 class TailJumpNode : public ReturnNode {
 182 public:
 183   TailJumpNode( Node *cntrl, Node *i_o, Node *memory, Node *frameptr, Node *target, Node *ex_oop)
 184     : ReturnNode(TypeFunc::Parms+2, cntrl, i_o, memory, frameptr, Compile::current()->top()) {
 185     init_req(TypeFunc::Parms, target);
 186     init_req(TypeFunc::Parms+1, ex_oop);
 187   }
 188 
 189   virtual int Opcode() const;
 190   virtual uint match_edge(uint idx) const;
 191 };
 192 
 193 //-------------------------------JVMState-------------------------------------
 194 // A linked list of JVMState nodes captures the whole interpreter state,
 195 // plus GC roots, for all active calls at some call site in this compilation
 196 // unit.  (If there is no inlining, then the list has exactly one link.)
 197 // This provides a way to map the optimized program back into the interpreter,
 198 // or to let the GC mark the stack.
 199 class JVMState : public ResourceObj {
 200 public:
 201   typedef enum {
 202     Reexecute_Undefined = -1, // not defined -- will be translated into false later
 203     Reexecute_False     =  0, // false       -- do not reexecute
 204     Reexecute_True      =  1  // true        -- reexecute the bytecode
 205   } ReexecuteState; //Reexecute State
 206 
 207 private:
 208   JVMState*         _caller;    // List pointer for forming scope chains
 209   uint              _depth;     // One more than caller depth, or one.
 210   uint              _locoff;    // Offset to locals in input edge mapping
 211   uint              _stkoff;    // Offset to stack in input edge mapping
 212   uint              _monoff;    // Offset to monitors in input edge mapping
 213   uint              _scloff;    // Offset to fields of scalar objs in input edge mapping
 214   uint              _endoff;    // Offset to end of input edge mapping
 215   uint              _sp;        // Java Expression Stack Pointer for this state
 216   int               _bci;       // Byte Code Index of this JVM point
 217   ReexecuteState    _reexecute; // Whether this bytecode need to be re-executed
 218   ciMethod*         _method;    // Method Pointer
 219   SafePointNode*    _map;       // Map node associated with this scope
 220 public:
 221   friend class Compile;
 222   friend class PreserveReexecuteState;
 223 
 224   // Because JVMState objects live over the entire lifetime of the
 225   // Compile object, they are allocated into the comp_arena, which
 226   // does not get resource marked or reset during the compile process
 227   void *operator new( size_t x, Compile* C ) throw() { return C->comp_arena()->Amalloc(x); }
 228   void operator delete( void * ) { } // fast deallocation
 229 
 230   // Create a new JVMState, ready for abstract interpretation.
 231   JVMState(ciMethod* method, JVMState* caller);
 232   JVMState(int stack_size);  // root state; has a null method
 233 
 234   // Access functions for the JVM
 235   // ... --|--- loc ---|--- stk ---|--- arg ---|--- mon ---|--- scl ---|
 236   //       \ locoff    \ stkoff    \ argoff    \ monoff    \ scloff    \ endoff
 237   uint              locoff() const { return _locoff; }
 238   uint              stkoff() const { return _stkoff; }
 239   uint              argoff() const { return _stkoff + _sp; }
 240   uint              monoff() const { return _monoff; }
 241   uint              scloff() const { return _scloff; }
 242   uint              endoff() const { return _endoff; }
 243   uint              oopoff() const { return debug_end(); }
 244 
 245   int            loc_size() const { return stkoff() - locoff(); }
 246   int            stk_size() const { return monoff() - stkoff(); }
 247   int            mon_size() const { return scloff() - monoff(); }
 248   int            scl_size() const { return endoff() - scloff(); }
 249 
 250   bool        is_loc(uint i) const { return locoff() <= i && i < stkoff(); }
 251   bool        is_stk(uint i) const { return stkoff() <= i && i < monoff(); }
 252   bool        is_mon(uint i) const { return monoff() <= i && i < scloff(); }
 253   bool        is_scl(uint i) const { return scloff() <= i && i < endoff(); }
 254 
 255   uint                      sp() const { return _sp; }
 256   int                      bci() const { return _bci; }
 257   bool        should_reexecute() const { return _reexecute==Reexecute_True; }
 258   bool  is_reexecute_undefined() const { return _reexecute==Reexecute_Undefined; }
 259   bool              has_method() const { return _method != nullptr; }
 260   ciMethod*             method() const { assert(has_method(), ""); return _method; }
 261   JVMState*             caller() const { return _caller; }
 262   SafePointNode*           map() const { return _map; }
 263   uint                   depth() const { return _depth; }
 264   uint             debug_start() const; // returns locoff of root caller
 265   uint               debug_end() const; // returns endoff of self
 266   uint              debug_size() const {
 267     return loc_size() + sp() + mon_size() + scl_size();
 268   }
 269   uint        debug_depth()  const; // returns sum of debug_size values at all depths
 270 
 271   // Returns the JVM state at the desired depth (1 == root).
 272   JVMState* of_depth(int d) const;
 273 
 274   // Tells if two JVM states have the same call chain (depth, methods, & bcis).
 275   bool same_calls_as(const JVMState* that) const;
 276 
 277   // Monitors (monitors are stored as (boxNode, objNode) pairs
 278   enum { logMonitorEdges = 1 };
 279   int  nof_monitors()              const { return mon_size() >> logMonitorEdges; }
 280   int  monitor_depth()             const { return nof_monitors() + (caller() ? caller()->monitor_depth() : 0); }
 281   int  monitor_box_offset(int idx) const { return monoff() + (idx << logMonitorEdges) + 0; }
 282   int  monitor_obj_offset(int idx) const { return monoff() + (idx << logMonitorEdges) + 1; }
 283   bool is_monitor_box(uint off)    const {
 284     assert(is_mon(off), "should be called only for monitor edge");
 285     return (0 == bitfield(off - monoff(), 0, logMonitorEdges));
 286   }
 287   bool is_monitor_use(uint off)    const { return (is_mon(off)
 288                                                    && is_monitor_box(off))
 289                                              || (caller() && caller()->is_monitor_use(off)); }
 290 
 291   // Initialization functions for the JVM
 292   void              set_locoff(uint off) { _locoff = off; }
 293   void              set_stkoff(uint off) { _stkoff = off; }
 294   void              set_monoff(uint off) { _monoff = off; }
 295   void              set_scloff(uint off) { _scloff = off; }
 296   void              set_endoff(uint off) { _endoff = off; }
 297   void              set_offsets(uint off) {
 298     _locoff = _stkoff = _monoff = _scloff = _endoff = off;
 299   }
 300   void              set_map(SafePointNode* map) { _map = map; }
 301   void              bind_map(SafePointNode* map); // set_map() and set_jvms() for the SafePointNode
 302   void              set_sp(uint sp) { _sp = sp; }
 303                     // _reexecute is initialized to "undefined" for a new bci
 304   void              set_bci(int bci) {if(_bci != bci)_reexecute=Reexecute_Undefined; _bci = bci; }
 305   void              set_should_reexecute(bool reexec) {_reexecute = reexec ? Reexecute_True : Reexecute_False;}
 306 
 307   // Miscellaneous utility functions
 308   JVMState* clone_deep(Compile* C) const;    // recursively clones caller chain
 309   JVMState* clone_shallow(Compile* C) const; // retains uncloned caller
 310   void      set_map_deep(SafePointNode *map);// reset map for all callers
 311   void      adapt_position(int delta);       // Adapt offsets in in-array after adding an edge.
 312   int       interpreter_frame_size() const;
 313 
 314 #ifndef PRODUCT
 315   void      print_method_with_lineno(outputStream* st, bool show_name) const;
 316   void      format(PhaseRegAlloc *regalloc, const Node *n, outputStream* st) const;
 317   void      dump_spec(outputStream *st) const;
 318   void      dump_on(outputStream* st) const;
 319   void      dump() const {
 320     dump_on(tty);
 321   }
 322 #endif
 323 };
 324 
 325 //------------------------------SafePointNode----------------------------------
 326 // A SafePointNode is a subclass of a MultiNode for convenience (and
 327 // potential code sharing) only - conceptually it is independent of
 328 // the Node semantics.
 329 class SafePointNode : public MultiNode {
 330   friend JVMState;
 331   friend class GraphKit;
 332 
 333   virtual bool           cmp( const Node &n ) const;
 334   virtual uint           size_of() const;       // Size is bigger
 335 
 336 protected:
 337   JVMState* const _jvms;      // Pointer to list of JVM State objects
 338   // Many calls take *all* of memory as input,
 339   // but some produce a limited subset of that memory as output.
 340   // The adr_type reports the call's behavior as a store, not a load.
 341   const TypePtr*  _adr_type;  // What type of memory does this node produce?
 342   ReplacedNodes   _replaced_nodes; // During parsing: list of pair of nodes from calls to GraphKit::replace_in_map()
 343   bool            _has_ea_local_in_scope; // NoEscape or ArgEscape objects in JVM States
 344 
 345   void set_jvms(JVMState* s) {
 346   assert(s != nullptr, "assign null value to _jvms");
 347     *(JVMState**)&_jvms = s;  // override const attribute in the accessor
 348   }
 349 public:
 350   SafePointNode(uint edges, JVMState* jvms,
 351                 // A plain safepoint advertises no memory effects (null):
 352                 const TypePtr* adr_type = nullptr)
 353     : MultiNode( edges ),
 354       _jvms(jvms),
 355       _adr_type(adr_type),
 356       _has_ea_local_in_scope(false)
 357   {
 358     init_class_id(Class_SafePoint);
 359   }
 360 
 361   JVMState* jvms() const { return _jvms; }
 362   virtual bool needs_deep_clone_jvms(Compile* C) { return false; }
 363   void clone_jvms(Compile* C) {
 364     if (jvms() != nullptr) {
 365       if (needs_deep_clone_jvms(C)) {
 366         set_jvms(jvms()->clone_deep(C));
 367         jvms()->set_map_deep(this);
 368       } else {
 369         jvms()->clone_shallow(C)->bind_map(this);
 370       }
 371     }
 372   }
 373 
 374  private:
 375   void verify_input(JVMState* jvms, uint idx) const {
 376     assert(verify_jvms(jvms), "jvms must match");
 377     Node* n = in(idx);
 378     assert((!n->bottom_type()->isa_long() && !n->bottom_type()->isa_double()) ||
 379            in(idx + 1)->is_top(), "2nd half of long/double");
 380   }
 381 
 382  public:
 383   // Functionality from old debug nodes which has changed
 384   Node *local(JVMState* jvms, uint idx) const {
 385     verify_input(jvms, jvms->locoff() + idx);
 386     return in(jvms->locoff() + idx);
 387   }
 388   Node *stack(JVMState* jvms, uint idx) const {
 389     verify_input(jvms, jvms->stkoff() + idx);
 390     return in(jvms->stkoff() + idx);
 391   }
 392   Node *argument(JVMState* jvms, uint idx) const {
 393     verify_input(jvms, jvms->argoff() + idx);
 394     return in(jvms->argoff() + idx);
 395   }
 396   Node *monitor_box(JVMState* jvms, uint idx) const {
 397     assert(verify_jvms(jvms), "jvms must match");
 398     return in(jvms->monitor_box_offset(idx));
 399   }
 400   Node *monitor_obj(JVMState* jvms, uint idx) const {
 401     assert(verify_jvms(jvms), "jvms must match");
 402     return in(jvms->monitor_obj_offset(idx));
 403   }
 404 
 405   void  set_local(JVMState* jvms, uint idx, Node *c);
 406 
 407   void  set_stack(JVMState* jvms, uint idx, Node *c) {
 408     assert(verify_jvms(jvms), "jvms must match");
 409     set_req(jvms->stkoff() + idx, c);
 410   }
 411   void  set_argument(JVMState* jvms, uint idx, Node *c) {
 412     assert(verify_jvms(jvms), "jvms must match");
 413     set_req(jvms->argoff() + idx, c);
 414   }
 415   void ensure_stack(JVMState* jvms, uint stk_size) {
 416     assert(verify_jvms(jvms), "jvms must match");
 417     int grow_by = (int)stk_size - (int)jvms->stk_size();
 418     if (grow_by > 0)  grow_stack(jvms, grow_by);
 419   }
 420   void grow_stack(JVMState* jvms, uint grow_by);
 421   // Handle monitor stack
 422   void push_monitor( const FastLockNode *lock );
 423   void pop_monitor ();
 424   Node *peek_monitor_box() const;
 425   Node *peek_monitor_obj() const;
 426   // Peek Operand Stacks, JVMS 2.6.2
 427   Node* peek_operand(uint off = 0) const;
 428 
 429   // Access functions for the JVM
 430   Node *control  () const { return in(TypeFunc::Control  ); }
 431   Node *i_o      () const { return in(TypeFunc::I_O      ); }
 432   Node *memory   () const { return in(TypeFunc::Memory   ); }
 433   Node *returnadr() const { return in(TypeFunc::ReturnAdr); }
 434   Node *frameptr () const { return in(TypeFunc::FramePtr ); }
 435 
 436   void set_control  ( Node *c ) { set_req(TypeFunc::Control,c); }
 437   void set_i_o      ( Node *c ) { set_req(TypeFunc::I_O    ,c); }
 438   void set_memory   ( Node *c ) { set_req(TypeFunc::Memory ,c); }
 439 
 440   MergeMemNode* merged_memory() const {
 441     return in(TypeFunc::Memory)->as_MergeMem();
 442   }
 443 
 444   // The parser marks useless maps as dead when it's done with them:
 445   bool is_killed() { return in(TypeFunc::Control) == nullptr; }
 446 
 447   // Exception states bubbling out of subgraphs such as inlined calls
 448   // are recorded here.  (There might be more than one, hence the "next".)
 449   // This feature is used only for safepoints which serve as "maps"
 450   // for JVM states during parsing, intrinsic expansion, etc.
 451   SafePointNode*         next_exception() const;
 452   void               set_next_exception(SafePointNode* n);
 453   bool                   has_exceptions() const { return next_exception() != nullptr; }
 454 
 455   // Helper methods to operate on replaced nodes
 456   ReplacedNodes replaced_nodes() const {
 457     return _replaced_nodes;
 458   }
 459 
 460   void set_replaced_nodes(ReplacedNodes replaced_nodes) {
 461     _replaced_nodes = replaced_nodes;
 462   }
 463 
 464   void clone_replaced_nodes() {
 465     _replaced_nodes.clone();
 466   }
 467   void record_replaced_node(Node* initial, Node* improved) {
 468     _replaced_nodes.record(initial, improved);
 469   }
 470   void transfer_replaced_nodes_from(SafePointNode* sfpt, uint idx = 0) {
 471     _replaced_nodes.transfer_from(sfpt->_replaced_nodes, idx);
 472   }
 473   void delete_replaced_nodes() {
 474     _replaced_nodes.reset();
 475   }
 476   void apply_replaced_nodes(uint idx) {
 477     _replaced_nodes.apply(this, idx);
 478   }
 479   void merge_replaced_nodes_with(SafePointNode* sfpt) {
 480     _replaced_nodes.merge_with(sfpt->_replaced_nodes);
 481   }
 482   bool has_replaced_nodes() const {
 483     return !_replaced_nodes.is_empty();
 484   }
 485   void set_has_ea_local_in_scope(bool b) {
 486     _has_ea_local_in_scope = b;
 487   }
 488   bool has_ea_local_in_scope() const {
 489     return _has_ea_local_in_scope;
 490   }
 491 
 492   void disconnect_from_root(PhaseIterGVN *igvn);
 493 
 494   // Standard Node stuff
 495   virtual int            Opcode() const;
 496   virtual bool           pinned() const { return true; }
 497   virtual const Type*    Value(PhaseGVN* phase) const;
 498   virtual const Type*    bottom_type() const { return Type::CONTROL; }
 499   virtual const TypePtr* adr_type() const { return _adr_type; }
 500   void set_adr_type(const TypePtr* adr_type) { _adr_type = adr_type; }
 501   virtual Node          *Ideal(PhaseGVN *phase, bool can_reshape);
 502   virtual Node*          Identity(PhaseGVN* phase);
 503   virtual uint           ideal_reg() const { return 0; }
 504   virtual const RegMask &in_RegMask(uint) const;
 505   virtual const RegMask &out_RegMask() const;
 506   virtual uint           match_edge(uint idx) const;
 507 
 508 #ifndef PRODUCT
 509   virtual void           dump_spec(outputStream *st) const;
 510 #endif
 511 };
 512 
 513 //------------------------------SafePointScalarObjectNode----------------------
 514 // A SafePointScalarObjectNode represents the state of a scalarized object
 515 // at a safepoint.
 516 class SafePointScalarObjectNode: public TypeNode {
 517   uint _first_index;              // First input edge relative index of a SafePoint node where
 518                                   // states of the scalarized object fields are collected.
 519   uint _depth;                    // Depth of the JVM state the _first_index field refers to
 520   uint _n_fields;                 // Number of non-static fields of the scalarized object.
 521 
 522   Node* _alloc;                   // Just for debugging purposes.
 523 
 524   virtual uint hash() const;
 525   virtual bool cmp( const Node &n ) const;
 526 
 527   uint first_index() const { return _first_index; }
 528 
 529 public:
 530   SafePointScalarObjectNode(const TypeOopPtr* tp, Node* alloc, uint first_index, uint depth, uint n_fields);
 531 
 532   virtual int Opcode() const;
 533   virtual uint           ideal_reg() const;
 534   virtual const RegMask &in_RegMask(uint) const;
 535   virtual const RegMask &out_RegMask() const;
 536   virtual uint           match_edge(uint idx) const;
 537 
 538   uint first_index(JVMState* jvms) const {
 539     assert(jvms != nullptr, "missed JVMS");
 540     return jvms->of_depth(_depth)->scloff() + _first_index;
 541   }
 542   uint n_fields()    const { return _n_fields; }
 543 
 544 #ifdef ASSERT
 545   Node* alloc() const { return _alloc; }
 546 #endif
 547 
 548   virtual uint size_of() const { return sizeof(*this); }
 549 
 550   // Assumes that "this" is an argument to a safepoint node "s", and that
 551   // "new_call" is being created to correspond to "s".  But the difference
 552   // between the start index of the jvmstates of "new_call" and "s" is
 553   // "jvms_adj".  Produce and return a SafePointScalarObjectNode that
 554   // corresponds appropriately to "this" in "new_call".  Assumes that
 555   // "sosn_map" is a map, specific to the translation of "s" to "new_call",
 556   // mapping old SafePointScalarObjectNodes to new, to avoid multiple copies.
 557   SafePointScalarObjectNode* clone(Dict* sosn_map, bool& new_node) const;
 558 
 559 #ifndef PRODUCT
 560   virtual void              dump_spec(outputStream *st) const;
 561 #endif
 562 };
 563 
 564 //------------------------------SafePointScalarMergeNode----------------------
 565 //
 566 // This class represents an allocation merge that is used as debug information
 567 // and had at least one of its input scalar replaced.
 568 //
 569 // The required inputs of this node, except the control, are pointers to
 570 // SafePointScalarObjectNodes that describe scalarized inputs of the original
 571 // allocation merge. The other(s) properties of the class are described below.
 572 //
 573 // _merge_pointer_idx : index in the SafePointNode's input array where the
 574 //   description of the _allocation merge_ starts. The index is zero based and
 575 //   relative to the SafePoint's scloff. The two entries in the SafePointNode's
 576 //   input array starting at '_merge_pointer_idx` are Phi nodes representing:
 577 //
 578 //   1) The original merge Phi. During rematerialization this input will only be
 579 //   used if the "selector Phi" (see below) indicates that the execution of the
 580 //   Phi took the path of a non scalarized input.
 581 //
 582 //   2) A "selector Phi". The output of this Phi will be '-1' if the execution
 583 //   of the method exercised a non scalarized input of the original Phi.
 584 //   Otherwise, the output will be >=0, and it will indicate the index-1 in the
 585 //   SafePointScalarMergeNode input array where the description of the
 586 //   scalarized object that should be used is.
 587 //
 588 // As an example, consider a Phi merging 3 inputs, of which the last 2 are
 589 // scalar replaceable.
 590 //
 591 //    Phi(Region, NSR, SR, SR)
 592 //
 593 // During scalar replacement the SR inputs will be changed to null:
 594 //
 595 //    Phi(Region, NSR, nullptr, nullptr)
 596 //
 597 // A corresponding selector Phi will be created with a configuration like this:
 598 //
 599 //    Phi(Region, -1, 0, 1)
 600 //
 601 // During execution of the compiled method, if the execution reaches a Trap, the
 602 // output of the selector Phi will tell if we need to rematerialize one of the
 603 // scalar replaced inputs or if we should just use the pointer returned by the
 604 // original Phi.
 605 
 606 class SafePointScalarMergeNode: public TypeNode {
 607   int _merge_pointer_idx;         // This is the first input edge relative
 608                                   // index of a SafePoint node where metadata information relative
 609                                   // to restoring the merge is stored. The corresponding input
 610                                   // in the associated SafePoint will point to a Phi representing
 611                                   // potential non-scalar replaced objects.
 612 
 613   virtual uint hash() const;
 614   virtual bool cmp( const Node &n ) const;
 615 
 616 public:
 617   SafePointScalarMergeNode(const TypeOopPtr* tp, int merge_pointer_idx);
 618 
 619   virtual int            Opcode() const;
 620   virtual uint           ideal_reg() const;
 621   virtual const RegMask &in_RegMask(uint) const;
 622   virtual const RegMask &out_RegMask() const;
 623   virtual uint           match_edge(uint idx) const;
 624 
 625   virtual uint size_of() const { return sizeof(*this); }
 626 
 627   int merge_pointer_idx(JVMState* jvms) const {
 628     assert(jvms != nullptr, "JVMS reference is null.");
 629     return jvms->scloff() + _merge_pointer_idx;
 630   }
 631 
 632   int selector_idx(JVMState* jvms) const {
 633     assert(jvms != nullptr, "JVMS reference is null.");
 634     return jvms->scloff() + _merge_pointer_idx + 1;
 635   }
 636 
 637   // Assumes that "this" is an argument to a safepoint node "s", and that
 638   // "new_call" is being created to correspond to "s".  But the difference
 639   // between the start index of the jvmstates of "new_call" and "s" is
 640   // "jvms_adj".  Produce and return a SafePointScalarObjectNode that
 641   // corresponds appropriately to "this" in "new_call".  Assumes that
 642   // "sosn_map" is a map, specific to the translation of "s" to "new_call",
 643   // mapping old SafePointScalarObjectNodes to new, to avoid multiple copies.
 644   SafePointScalarMergeNode* clone(Dict* sosn_map, bool& new_node) const;
 645 
 646 #ifndef PRODUCT
 647   virtual void              dump_spec(outputStream *st) const;
 648 #endif
 649 };
 650 
 651 // Simple container for the outgoing projections of a call.  Useful
 652 // for serious surgery on calls.
 653 class CallProjections {
 654 public:
 655   Node* fallthrough_proj;
 656   Node* fallthrough_catchproj;
 657   Node* fallthrough_memproj;
 658   Node* fallthrough_ioproj;
 659   Node* catchall_catchproj;
 660   Node* catchall_memproj;
 661   Node* catchall_ioproj;
 662   Node* exobj;
 663   uint nb_resproj;
 664   Node* resproj[1]; // at least one projection
 665 
 666   CallProjections(uint nbres) {
 667     fallthrough_proj      = nullptr;
 668     fallthrough_catchproj = nullptr;
 669     fallthrough_memproj   = nullptr;
 670     fallthrough_ioproj    = nullptr;
 671     catchall_catchproj    = nullptr;
 672     catchall_memproj      = nullptr;
 673     catchall_ioproj       = nullptr;
 674     exobj                 = nullptr;
 675     nb_resproj            = nbres;
 676     resproj[0]            = nullptr;
 677     for (uint i = 1; i < nb_resproj; i++) {
 678       resproj[i]          = nullptr;
 679     }
 680   }
 681 
 682 };
 683 
 684 class CallGenerator;
 685 
 686 //------------------------------CallNode---------------------------------------
 687 // Call nodes now subsume the function of debug nodes at callsites, so they
 688 // contain the functionality of a full scope chain of debug nodes.
 689 class CallNode : public SafePointNode {
 690 
 691 protected:
 692   bool may_modify_arraycopy_helper(const TypeOopPtr* dest_t, const TypeOopPtr* t_oop, PhaseValues* phase);
 693 
 694 public:
 695   const TypeFunc* _tf;          // Function type
 696   address         _entry_point; // Address of method being called
 697   float           _cnt;         // Estimate of number of times called
 698   CallGenerator*  _generator;   // corresponding CallGenerator for some late inline calls
 699   const char*     _name;        // Printable name, if _method is null
 700 
 701   CallNode(const TypeFunc* tf, address addr, const TypePtr* adr_type, JVMState* jvms = nullptr)
 702     : SafePointNode(tf->domain_cc()->cnt(), jvms, adr_type),
 703       _tf(tf),
 704       _entry_point(addr),
 705       _cnt(COUNT_UNKNOWN),
 706       _generator(nullptr),
 707       _name(nullptr)
 708   {
 709     init_class_id(Class_Call);
 710   }
 711 
 712   const TypeFunc* tf()         const { return _tf; }
 713   address  entry_point()       const { return _entry_point; }
 714   float    cnt()               const { return _cnt; }
 715   CallGenerator* generator()   const { return _generator; }
 716 
 717   void set_tf(const TypeFunc* tf)       { _tf = tf; }
 718   void set_entry_point(address p)       { _entry_point = p; }
 719   void set_cnt(float c)                 { _cnt = c; }
 720   void set_generator(CallGenerator* cg) { _generator = cg; }
 721 
 722   virtual const Type* bottom_type() const;
 723   virtual const Type* Value(PhaseGVN* phase) const;
 724   virtual Node* Ideal(PhaseGVN* phase, bool can_reshape);
 725   virtual Node* Identity(PhaseGVN* phase) { return this; }
 726   virtual bool        cmp(const Node &n) const;
 727   virtual uint        size_of() const = 0;
 728   virtual void        calling_convention(BasicType* sig_bt, VMRegPair* parm_regs, uint argcnt) const;
 729   virtual Node*       match(const ProjNode* proj, const Matcher* m, const RegMask* mask);
 730   virtual uint        ideal_reg() const { return NotAMachineReg; }
 731   // Are we guaranteed that this node is a safepoint?  Not true for leaf calls and
 732   // for some macro nodes whose expansion does not have a safepoint on the fast path.
 733   virtual bool        guaranteed_safepoint()  { return true; }
 734   // For macro nodes, the JVMState gets modified during expansion. If calls
 735   // use MachConstantBase, it gets modified during matching. So when cloning
 736   // the node the JVMState must be deep cloned. Default is to shallow clone.
 737   virtual bool needs_deep_clone_jvms(Compile* C) { return C->needs_deep_clone_jvms(); }
 738 
 739   // Returns true if the call may modify n
 740   virtual bool        may_modify(const TypeOopPtr* t_oop, PhaseValues* phase);
 741   // Does this node have a use of n other than in debug information?
 742   bool                has_non_debug_use(Node* n);
 743   bool                has_debug_use(Node* n);
 744   // Returns the unique CheckCastPP of a call
 745   // or result projection is there are several CheckCastPP
 746   // or returns null if there is no one.
 747   Node* result_cast();
 748   // Does this node returns pointer?
 749   bool returns_pointer() const {
 750     const TypeTuple* r = tf()->range_sig();
 751     return (!tf()->returns_inline_type_as_fields() &&
 752             r->cnt() > TypeFunc::Parms &&
 753             r->field_at(TypeFunc::Parms)->isa_ptr());
 754   }
 755 
 756   // Collect all the interesting edges from a call for use in
 757   // replacing the call by something else.  Used by macro expansion
 758   // and the late inlining support.
 759   CallProjections* extract_projections(bool separate_io_proj, bool do_asserts = true);
 760 
 761   virtual uint match_edge(uint idx) const;
 762 
 763   bool is_call_to_arraycopystub() const;
 764 
 765   virtual void copy_call_debug_info(PhaseIterGVN* phase, SafePointNode* sfpt) {}
 766 
 767 #ifndef PRODUCT
 768   virtual void        dump_req(outputStream* st = tty, DumpConfig* dc = nullptr) const;
 769   virtual void        dump_spec(outputStream* st) const;
 770 #endif
 771 };
 772 
 773 
 774 //------------------------------CallJavaNode-----------------------------------
 775 // Make a static or dynamic subroutine call node using Java calling
 776 // convention.  (The "Java" calling convention is the compiler's calling
 777 // convention, as opposed to the interpreter's or that of native C.)
 778 class CallJavaNode : public CallNode {
 779 protected:
 780   virtual bool cmp( const Node &n ) const;
 781   virtual uint size_of() const; // Size is bigger
 782 
 783   ciMethod* _method;               // Method being direct called
 784   bool    _optimized_virtual;
 785   bool    _method_handle_invoke;
 786   bool    _override_symbolic_info; // Override symbolic call site info from bytecode
 787   bool    _arg_escape;             // ArgEscape in parameter list
 788 public:
 789   CallJavaNode(const TypeFunc* tf , address addr, ciMethod* method)
 790     : CallNode(tf, addr, TypePtr::BOTTOM),
 791       _method(method),
 792       _optimized_virtual(false),
 793       _method_handle_invoke(false),
 794       _override_symbolic_info(false),
 795       _arg_escape(false)
 796   {
 797     init_class_id(Class_CallJava);
 798   }
 799 
 800   virtual int   Opcode() const;
 801   ciMethod* method() const                 { return _method; }
 802   void  set_method(ciMethod *m)            { _method = m; }
 803   void  set_optimized_virtual(bool f)      { _optimized_virtual = f; }
 804   bool  is_optimized_virtual() const       { return _optimized_virtual; }
 805   void  set_method_handle_invoke(bool f)   { _method_handle_invoke = f; }
 806   bool  is_method_handle_invoke() const    { return _method_handle_invoke; }
 807   void  set_override_symbolic_info(bool f) { _override_symbolic_info = f; }
 808   bool  override_symbolic_info() const     { return _override_symbolic_info; }
 809   void  set_arg_escape(bool f)             { _arg_escape = f; }
 810   bool  arg_escape() const                 { return _arg_escape; }
 811   void copy_call_debug_info(PhaseIterGVN* phase, SafePointNode *sfpt);
 812 
 813   DEBUG_ONLY( bool validate_symbolic_info() const; )
 814 
 815 #ifndef PRODUCT
 816   virtual void  dump_spec(outputStream *st) const;
 817   virtual void  dump_compact_spec(outputStream *st) const;
 818 #endif
 819 };
 820 
 821 //------------------------------CallStaticJavaNode-----------------------------
 822 // Make a direct subroutine call using Java calling convention (for static
 823 // calls and optimized virtual calls, plus calls to wrappers for run-time
 824 // routines); generates static stub.
 825 class CallStaticJavaNode : public CallJavaNode {
 826   virtual bool cmp( const Node &n ) const;
 827   virtual uint size_of() const; // Size is bigger
 828 
 829   bool remove_unknown_flat_array_load(PhaseIterGVN* igvn, Node* ctl, Node* mem, Node* unc_arg);
 830 
 831 public:
 832   CallStaticJavaNode(Compile* C, const TypeFunc* tf, address addr, ciMethod* method)
 833     : CallJavaNode(tf, addr, method) {
 834     init_class_id(Class_CallStaticJava);
 835     if (C->eliminate_boxing() && (method != nullptr) && method->is_boxing_method()) {
 836       init_flags(Flag_is_macro);
 837       C->add_macro_node(this);
 838     }
 839     const TypeTuple *r = tf->range_sig();
 840     if (InlineTypeReturnedAsFields &&
 841         method != nullptr &&
 842         method->is_method_handle_intrinsic() &&
 843         r->cnt() > TypeFunc::Parms &&
 844         r->field_at(TypeFunc::Parms)->isa_oopptr() &&
 845         r->field_at(TypeFunc::Parms)->is_oopptr()->can_be_inline_type()) {
 846       // Make sure this call is processed by PhaseMacroExpand::expand_mh_intrinsic_return
 847       init_flags(Flag_is_macro);
 848       C->add_macro_node(this);
 849     }
 850   }
 851   CallStaticJavaNode(const TypeFunc* tf, address addr, const char* name, const TypePtr* adr_type)
 852     : CallJavaNode(tf, addr, nullptr) {
 853     init_class_id(Class_CallStaticJava);
 854     // This node calls a runtime stub, which often has narrow memory effects.
 855     _adr_type = adr_type;
 856     _name = name;
 857   }
 858 
 859   // If this is an uncommon trap, return the request code, else zero.
 860   int uncommon_trap_request() const;
 861   bool is_uncommon_trap() const;
 862   static int extract_uncommon_trap_request(const Node* call);
 863 
 864   bool is_boxing_method() const {
 865     return is_macro() && (method() != nullptr) && method()->is_boxing_method();
 866   }
 867   // Late inlining modifies the JVMState, so we need to deep clone it
 868   // when the call node is cloned (because it is macro node).
 869   virtual bool needs_deep_clone_jvms(Compile* C) {
 870     return is_boxing_method() || CallNode::needs_deep_clone_jvms(C);
 871   }
 872 
 873   virtual int         Opcode() const;
 874   virtual Node* Ideal(PhaseGVN* phase, bool can_reshape);
 875 
 876 #ifndef PRODUCT
 877   virtual void        dump_spec(outputStream *st) const;
 878   virtual void        dump_compact_spec(outputStream *st) const;
 879 #endif
 880 };
 881 
 882 //------------------------------CallDynamicJavaNode----------------------------
 883 // Make a dispatched call using Java calling convention.
 884 class CallDynamicJavaNode : public CallJavaNode {
 885   virtual bool cmp( const Node &n ) const;
 886   virtual uint size_of() const; // Size is bigger
 887 public:
 888   CallDynamicJavaNode(const TypeFunc* tf , address addr, ciMethod* method, int vtable_index)
 889     : CallJavaNode(tf,addr,method), _vtable_index(vtable_index) {
 890     init_class_id(Class_CallDynamicJava);
 891   }
 892 
 893   // Late inlining modifies the JVMState, so we need to deep clone it
 894   // when the call node is cloned.
 895   virtual bool needs_deep_clone_jvms(Compile* C) {
 896     return IncrementalInlineVirtual || CallNode::needs_deep_clone_jvms(C);
 897   }
 898 
 899   int _vtable_index;
 900   virtual int   Opcode() const;
 901   virtual Node* Ideal(PhaseGVN* phase, bool can_reshape);
 902 #ifndef PRODUCT
 903   virtual void  dump_spec(outputStream *st) const;
 904 #endif
 905 };
 906 
 907 //------------------------------CallRuntimeNode--------------------------------
 908 // Make a direct subroutine call node into compiled C++ code.
 909 class CallRuntimeNode : public CallNode {
 910 protected:
 911   virtual bool cmp( const Node &n ) const;
 912   virtual uint size_of() const; // Size is bigger
 913 public:
 914   CallRuntimeNode(const TypeFunc* tf, address addr, const char* name,
 915                   const TypePtr* adr_type, JVMState* jvms = nullptr)
 916     : CallNode(tf, addr, adr_type, jvms)
 917   {
 918     init_class_id(Class_CallRuntime);
 919     _name = name;
 920   }
 921 
 922   virtual int   Opcode() const;
 923   virtual void  calling_convention( BasicType* sig_bt, VMRegPair *parm_regs, uint argcnt ) const;
 924 
 925 #ifndef PRODUCT
 926   virtual void  dump_spec(outputStream *st) const;
 927 #endif
 928 };
 929 
 930 //------------------------------CallLeafNode-----------------------------------
 931 // Make a direct subroutine call node into compiled C++ code, without
 932 // safepoints
 933 class CallLeafNode : public CallRuntimeNode {
 934 public:
 935   CallLeafNode(const TypeFunc* tf, address addr, const char* name,
 936                const TypePtr* adr_type)
 937     : CallRuntimeNode(tf, addr, name, adr_type)
 938   {
 939     init_class_id(Class_CallLeaf);
 940   }
 941   virtual int   Opcode() const;
 942   virtual bool        guaranteed_safepoint()  { return false; }
 943 #ifndef PRODUCT
 944   virtual void  dump_spec(outputStream *st) const;
 945 #endif
 946 };
 947 
 948 //------------------------------CallLeafNoFPNode-------------------------------
 949 // CallLeafNode, not using floating point or using it in the same manner as
 950 // the generated code
 951 class CallLeafNoFPNode : public CallLeafNode {
 952 public:
 953   CallLeafNoFPNode(const TypeFunc* tf, address addr, const char* name,
 954                    const TypePtr* adr_type)
 955     : CallLeafNode(tf, addr, name, adr_type)
 956   {
 957     init_class_id(Class_CallLeafNoFP);
 958   }
 959   virtual int   Opcode() const;
 960   virtual uint match_edge(uint idx) const;
 961 };
 962 
 963 //------------------------------CallLeafVectorNode-------------------------------
 964 // CallLeafNode but calling with vector calling convention instead.
 965 class CallLeafVectorNode : public CallLeafNode {
 966 private:
 967   uint _num_bits;
 968 protected:
 969   virtual bool cmp( const Node &n ) const;
 970   virtual uint size_of() const; // Size is bigger
 971 public:
 972   CallLeafVectorNode(const TypeFunc* tf, address addr, const char* name,
 973                    const TypePtr* adr_type, uint num_bits)
 974     : CallLeafNode(tf, addr, name, adr_type), _num_bits(num_bits)
 975   {
 976   }
 977   virtual int   Opcode() const;
 978   virtual void  calling_convention( BasicType* sig_bt, VMRegPair *parm_regs, uint argcnt ) const;
 979 };
 980 
 981 
 982 //------------------------------Allocate---------------------------------------
 983 // High-level memory allocation
 984 //
 985 //  AllocateNode and AllocateArrayNode are subclasses of CallNode because they will
 986 //  get expanded into a code sequence containing a call.  Unlike other CallNodes,
 987 //  they have 2 memory projections and 2 i_o projections (which are distinguished by
 988 //  the _is_io_use flag in the projection.)  This is needed when expanding the node in
 989 //  order to differentiate the uses of the projection on the normal control path from
 990 //  those on the exception return path.
 991 //
 992 class AllocateNode : public CallNode {
 993 public:
 994   enum {
 995     // Output:
 996     RawAddress  = TypeFunc::Parms,    // the newly-allocated raw address
 997     // Inputs:
 998     AllocSize   = TypeFunc::Parms,    // size (in bytes) of the new object
 999     KlassNode,                        // type (maybe dynamic) of the obj.
1000     InitialTest,                      // slow-path test (may be constant)
1001     ALength,                          // array length (or TOP if none)
1002     ValidLengthTest,
1003     InlineType,                       // InlineTypeNode if this is an inline type allocation
1004     DefaultValue,                     // default value in case of non-flat inline type array
1005     RawDefaultValue,                  // same as above but as raw machine word
1006     ParmLimit
1007   };
1008 
1009   static const TypeFunc* alloc_type(const Type* t) {
1010     const Type** fields = TypeTuple::fields(ParmLimit - TypeFunc::Parms);
1011     fields[AllocSize]   = TypeInt::POS;
1012     fields[KlassNode]   = TypeInstPtr::NOTNULL;
1013     fields[InitialTest] = TypeInt::BOOL;
1014     fields[ALength]     = t;  // length (can be a bad length)
1015     fields[ValidLengthTest] = TypeInt::BOOL;
1016     fields[InlineType] = Type::BOTTOM;
1017     fields[DefaultValue] = TypeInstPtr::NOTNULL;
1018     fields[RawDefaultValue] = TypeX_X;
1019 
1020     const TypeTuple *domain = TypeTuple::make(ParmLimit, fields);
1021 
1022     // create result type (range)
1023     fields = TypeTuple::fields(1);
1024     fields[TypeFunc::Parms+0] = TypeRawPtr::NOTNULL; // Returned oop
1025 
1026     const TypeTuple *range = TypeTuple::make(TypeFunc::Parms+1, fields);
1027 
1028     return TypeFunc::make(domain, range);
1029   }
1030 
1031   // Result of Escape Analysis
1032   bool _is_scalar_replaceable;
1033   bool _is_non_escaping;
1034   // True when MemBar for new is redundant with MemBar at initialzer exit
1035   bool _is_allocation_MemBar_redundant;
1036   bool _larval;
1037 
1038   virtual uint size_of() const; // Size is bigger
1039   AllocateNode(Compile* C, const TypeFunc *atype, Node *ctrl, Node *mem, Node *abio,
1040                Node *size, Node *klass_node, Node *initial_test,
1041                InlineTypeNode* inline_type_node = nullptr);
1042   // Expansion modifies the JVMState, so we need to deep clone it
1043   virtual bool needs_deep_clone_jvms(Compile* C) { return true; }
1044   virtual int Opcode() const;
1045   virtual uint ideal_reg() const { return Op_RegP; }
1046   virtual bool        guaranteed_safepoint()  { return false; }
1047 
1048   // allocations do not modify their arguments
1049   virtual bool        may_modify(const TypeOopPtr* t_oop, PhaseValues* phase) { return false;}
1050 
1051   // Pattern-match a possible usage of AllocateNode.
1052   // Return null if no allocation is recognized.
1053   // The operand is the pointer produced by the (possible) allocation.
1054   // It must be a projection of the Allocate or its subsequent CastPP.
1055   // (Note:  This function is defined in file graphKit.cpp, near
1056   // GraphKit::new_instance/new_array, whose output it recognizes.)
1057   // The 'ptr' may not have an offset unless the 'offset' argument is given.
1058   static AllocateNode* Ideal_allocation(Node* ptr);
1059 
1060   // Fancy version which uses AddPNode::Ideal_base_and_offset to strip
1061   // an offset, which is reported back to the caller.
1062   // (Note:  AllocateNode::Ideal_allocation is defined in graphKit.cpp.)
1063   static AllocateNode* Ideal_allocation(Node* ptr, PhaseValues* phase,
1064                                         intptr_t& offset);
1065 
1066   // Dig the klass operand out of a (possible) allocation site.
1067   static Node* Ideal_klass(Node* ptr, PhaseValues* phase) {
1068     AllocateNode* allo = Ideal_allocation(ptr);
1069     return (allo == nullptr) ? nullptr : allo->in(KlassNode);
1070   }
1071 
1072   // Conservatively small estimate of offset of first non-header byte.
1073   int minimum_header_size() {
1074     return is_AllocateArray() ? arrayOopDesc::base_offset_in_bytes(T_BYTE) :
1075                                 instanceOopDesc::base_offset_in_bytes();
1076   }
1077 
1078   // Return the corresponding initialization barrier (or null if none).
1079   // Walks out edges to find it...
1080   // (Note: Both InitializeNode::allocation and AllocateNode::initialization
1081   // are defined in graphKit.cpp, which sets up the bidirectional relation.)
1082   InitializeNode* initialization();
1083 
1084   // Convenience for initialization->maybe_set_complete(phase)
1085   bool maybe_set_complete(PhaseGVN* phase);
1086 
1087   // Return true if allocation doesn't escape thread, its escape state
1088   // needs be noEscape or ArgEscape. InitializeNode._does_not_escape
1089   // is true when its allocation's escape state is noEscape or
1090   // ArgEscape. In case allocation's InitializeNode is null, check
1091   // AlllocateNode._is_non_escaping flag.
1092   // AlllocateNode._is_non_escaping is true when its escape state is
1093   // noEscape.
1094   bool does_not_escape_thread() {
1095     InitializeNode* init = nullptr;
1096     return _is_non_escaping || (((init = initialization()) != nullptr) && init->does_not_escape());
1097   }
1098 
1099   // If object doesn't escape in <.init> method and there is memory barrier
1100   // inserted at exit of its <.init>, memory barrier for new is not necessary.
1101   // Inovke this method when MemBar at exit of initializer and post-dominate
1102   // allocation node.
1103   void compute_MemBar_redundancy(ciMethod* initializer);
1104   bool is_allocation_MemBar_redundant() { return _is_allocation_MemBar_redundant; }
1105 
1106   Node* make_ideal_mark(PhaseGVN* phase, Node* control, Node* mem);
1107 };
1108 
1109 //------------------------------AllocateArray---------------------------------
1110 //
1111 // High-level array allocation
1112 //
1113 class AllocateArrayNode : public AllocateNode {
1114 public:
1115   AllocateArrayNode(Compile* C, const TypeFunc* atype, Node* ctrl, Node* mem, Node* abio, Node* size, Node* klass_node,
1116                     Node* initial_test, Node* count_val, Node* valid_length_test,
1117                     Node* default_value, Node* raw_default_value)
1118     : AllocateNode(C, atype, ctrl, mem, abio, size, klass_node,
1119                    initial_test)
1120   {
1121     init_class_id(Class_AllocateArray);
1122     set_req(AllocateNode::ALength,        count_val);
1123     set_req(AllocateNode::ValidLengthTest, valid_length_test);
1124     init_req(AllocateNode::DefaultValue,  default_value);
1125     init_req(AllocateNode::RawDefaultValue, raw_default_value);
1126   }
1127   virtual uint size_of() const { return sizeof(*this); }
1128   virtual int Opcode() const;
1129 
1130   // Dig the length operand out of a array allocation site.
1131   Node* Ideal_length() {
1132     return in(AllocateNode::ALength);
1133   }
1134 
1135   // Dig the length operand out of a array allocation site and narrow the
1136   // type with a CastII, if necesssary
1137   Node* make_ideal_length(const TypeOopPtr* ary_type, PhaseValues* phase, bool can_create = true);
1138 
1139   // Pattern-match a possible usage of AllocateArrayNode.
1140   // Return null if no allocation is recognized.
1141   static AllocateArrayNode* Ideal_array_allocation(Node* ptr) {
1142     AllocateNode* allo = Ideal_allocation(ptr);
1143     return (allo == nullptr || !allo->is_AllocateArray())
1144            ? nullptr : allo->as_AllocateArray();
1145   }
1146 };
1147 
1148 //------------------------------AbstractLockNode-----------------------------------
1149 class AbstractLockNode: public CallNode {
1150 private:
1151   enum {
1152     Regular = 0,  // Normal lock
1153     NonEscObj,    // Lock is used for non escaping object
1154     Coarsened,    // Lock was coarsened
1155     Nested        // Nested lock
1156   } _kind;
1157 
1158   static const char* _kind_names[Nested+1];
1159 
1160 #ifndef PRODUCT
1161   NamedCounter* _counter;
1162 #endif
1163 
1164 protected:
1165   // helper functions for lock elimination
1166   //
1167 
1168   bool find_matching_unlock(const Node* ctrl, LockNode* lock,
1169                             GrowableArray<AbstractLockNode*> &lock_ops);
1170   bool find_lock_and_unlock_through_if(Node* node, LockNode* lock,
1171                                        GrowableArray<AbstractLockNode*> &lock_ops);
1172   bool find_unlocks_for_region(const RegionNode* region, LockNode* lock,
1173                                GrowableArray<AbstractLockNode*> &lock_ops);
1174   LockNode *find_matching_lock(UnlockNode* unlock);
1175 
1176   // Update the counter to indicate that this lock was eliminated.
1177   void set_eliminated_lock_counter() PRODUCT_RETURN;
1178 
1179 public:
1180   AbstractLockNode(const TypeFunc *tf)
1181     : CallNode(tf, nullptr, TypeRawPtr::BOTTOM),
1182       _kind(Regular)
1183   {
1184 #ifndef PRODUCT
1185     _counter = nullptr;
1186 #endif
1187   }
1188   virtual int Opcode() const = 0;
1189   Node *   obj_node() const       {return in(TypeFunc::Parms + 0); }
1190   Node *   box_node() const       {return in(TypeFunc::Parms + 1); }
1191   Node *   fastlock_node() const  {return in(TypeFunc::Parms + 2); }
1192   void     set_box_node(Node* box) { set_req(TypeFunc::Parms + 1, box); }
1193 
1194   const Type *sub(const Type *t1, const Type *t2) const { return TypeInt::CC;}
1195 
1196   virtual uint size_of() const { return sizeof(*this); }
1197 
1198   bool is_eliminated()  const { return (_kind != Regular); }
1199   bool is_non_esc_obj() const { return (_kind == NonEscObj); }
1200   bool is_coarsened()   const { return (_kind == Coarsened); }
1201   bool is_nested()      const { return (_kind == Nested); }
1202 
1203   const char * kind_as_string() const;
1204   void log_lock_optimization(Compile* c, const char * tag, Node* bad_lock = nullptr) const;
1205 
1206   void set_non_esc_obj() { _kind = NonEscObj; set_eliminated_lock_counter(); }
1207   void set_coarsened()   { _kind = Coarsened; set_eliminated_lock_counter(); }
1208   void set_nested()      { _kind = Nested; set_eliminated_lock_counter(); }
1209 
1210   // Check that all locks/unlocks associated with object come from balanced regions.
1211   // They can become unbalanced after coarsening optimization or on OSR entry.
1212   bool is_balanced();
1213 
1214   // locking does not modify its arguments
1215   virtual bool may_modify(const TypeOopPtr* t_oop, PhaseValues* phase){ return false; }
1216 
1217 #ifndef PRODUCT
1218   void create_lock_counter(JVMState* s);
1219   NamedCounter* counter() const { return _counter; }
1220   virtual void dump_spec(outputStream* st) const;
1221   virtual void dump_compact_spec(outputStream* st) const;
1222 #endif
1223 };
1224 
1225 //------------------------------Lock---------------------------------------
1226 // High-level lock operation
1227 //
1228 // This is a subclass of CallNode because it is a macro node which gets expanded
1229 // into a code sequence containing a call.  This node takes 3 "parameters":
1230 //    0  -  object to lock
1231 //    1 -   a BoxLockNode
1232 //    2 -   a FastLockNode
1233 //
1234 class LockNode : public AbstractLockNode {
1235   static const TypeFunc* _lock_type_Type;
1236 public:
1237 
1238   static inline const TypeFunc* lock_type() {
1239     assert(_lock_type_Type != nullptr, "should be initialized");
1240     return _lock_type_Type;
1241   }
1242 
1243   static void initialize_lock_Type() {
1244     assert(_lock_type_Type == nullptr, "should be called once");
1245     // create input type (domain)
1246     const Type **fields = TypeTuple::fields(3);
1247     fields[TypeFunc::Parms+0] = TypeInstPtr::NOTNULL;  // Object to be Locked
1248     fields[TypeFunc::Parms+1] = TypeRawPtr::BOTTOM;    // Address of stack location for lock
1249     fields[TypeFunc::Parms+2] = TypeInt::BOOL;         // FastLock
1250     const TypeTuple *domain = TypeTuple::make(TypeFunc::Parms+3,fields);
1251 
1252     // create result type (range)
1253     fields = TypeTuple::fields(0);
1254 
1255     const TypeTuple *range = TypeTuple::make(TypeFunc::Parms+0,fields);
1256 
1257     _lock_type_Type = TypeFunc::make(domain,range);
1258   }
1259 
1260   virtual int Opcode() const;
1261   virtual uint size_of() const; // Size is bigger
1262   LockNode(Compile* C, const TypeFunc *tf) : AbstractLockNode( tf ) {
1263     init_class_id(Class_Lock);
1264     init_flags(Flag_is_macro);
1265     C->add_macro_node(this);
1266   }
1267   virtual bool        guaranteed_safepoint()  { return false; }
1268 
1269   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
1270   // Expansion modifies the JVMState, so we need to deep clone it
1271   virtual bool needs_deep_clone_jvms(Compile* C) { return true; }
1272 
1273   bool is_nested_lock_region(); // Is this Lock nested?
1274   bool is_nested_lock_region(Compile * c); // Why isn't this Lock nested?
1275 };
1276 
1277 //------------------------------Unlock---------------------------------------
1278 // High-level unlock operation
1279 class UnlockNode : public AbstractLockNode {
1280 private:
1281 #ifdef ASSERT
1282   JVMState* const _dbg_jvms;      // Pointer to list of JVM State objects
1283 #endif
1284 public:
1285   virtual int Opcode() const;
1286   virtual uint size_of() const; // Size is bigger
1287   UnlockNode(Compile* C, const TypeFunc *tf) : AbstractLockNode( tf )
1288 #ifdef ASSERT
1289     , _dbg_jvms(nullptr)
1290 #endif
1291   {
1292     init_class_id(Class_Unlock);
1293     init_flags(Flag_is_macro);
1294     C->add_macro_node(this);
1295   }
1296   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
1297   // unlock is never a safepoint
1298   virtual bool        guaranteed_safepoint()  { return false; }
1299 #ifdef ASSERT
1300   void set_dbg_jvms(JVMState* s) {
1301     *(JVMState**)&_dbg_jvms = s;  // override const attribute in the accessor
1302   }
1303   JVMState* dbg_jvms() const { return _dbg_jvms; }
1304 #else
1305   JVMState* dbg_jvms() const { return nullptr; }
1306 #endif
1307 };
1308 #endif // SHARE_OPTO_CALLNODE_HPP