1 /*
   2  * Copyright (c) 1997, 2010, 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_NODE_HPP
  26 #define SHARE_VM_OPTO_NODE_HPP
  27 
  28 #include "libadt/port.hpp"
  29 #include "libadt/vectset.hpp"
  30 #include "opto/compile.hpp"
  31 #include "opto/type.hpp"
  32 
  33 // Portions of code courtesy of Clifford Click
  34 
  35 // Optimization - Graph Style
  36 
  37 
  38 class AbstractLockNode;
  39 class AddNode;
  40 class AddPNode;
  41 class AliasInfo;
  42 class AllocateArrayNode;
  43 class AllocateNode;
  44 class Block;
  45 class Block_Array;
  46 class BoolNode;
  47 class BoxLockNode;
  48 class CMoveNode;
  49 class CallDynamicJavaNode;
  50 class CallJavaNode;
  51 class CallLeafNode;
  52 class CallNode;
  53 class CallRuntimeNode;
  54 class CallStaticJavaNode;
  55 class CatchNode;
  56 class CatchProjNode;
  57 class CheckCastPPNode;
  58 class ClearArrayNode;
  59 class CmpNode;
  60 class CodeBuffer;
  61 class ConstraintCastNode;
  62 class ConNode;
  63 class CountedLoopNode;
  64 class CountedLoopEndNode;
  65 class DecodeNNode;
  66 class EncodePNode;
  67 class FastLockNode;
  68 class FastUnlockNode;
  69 class IfNode;
  70 class InitializeNode;
  71 class JVMState;
  72 class JumpNode;
  73 class JumpProjNode;
  74 class LoadNode;
  75 class LoadStoreNode;
  76 class LockNode;
  77 class LoopNode;
  78 class MachCallDynamicJavaNode;
  79 class MachCallJavaNode;
  80 class MachCallLeafNode;
  81 class MachCallNode;
  82 class MachCallRuntimeNode;
  83 class MachCallStaticJavaNode;
  84 class MachConstantBaseNode;
  85 class MachConstantNode;
  86 class MachIfNode;
  87 class MachNode;
  88 class MachNullCheckNode;
  89 class MachReturnNode;
  90 class MachSafePointNode;
  91 class MachSpillCopyNode;
  92 class MachTempNode;
  93 class Matcher;
  94 class MemBarNode;
  95 class MemNode;
  96 class MergeMemNode;
  97 class MulNode;
  98 class MultiNode;
  99 class MultiBranchNode;
 100 class NeverBranchNode;
 101 class Node;
 102 class Node_Array;
 103 class Node_List;
 104 class Node_Stack;
 105 class NullCheckNode;
 106 class OopMap;
 107 class ParmNode;
 108 class PCTableNode;
 109 class PhaseCCP;
 110 class PhaseGVN;
 111 class PhaseIterGVN;
 112 class PhaseRegAlloc;
 113 class PhaseTransform;
 114 class PhaseValues;
 115 class PhiNode;
 116 class Pipeline;
 117 class ProjNode;
 118 class RegMask;
 119 class RegionNode;
 120 class RootNode;
 121 class SafePointNode;
 122 class SafePointScalarObjectNode;
 123 class StartNode;
 124 class State;
 125 class StoreNode;
 126 class SubNode;
 127 class Type;
 128 class TypeNode;
 129 class UnlockNode;
 130 class VectorSet;
 131 class IfTrueNode;
 132 class IfFalseNode;
 133 typedef void (*NFunc)(Node&,void*);
 134 extern "C" {
 135   typedef int (*C_sort_func_t)(const void *, const void *);
 136 }
 137 
 138 // The type of all node counts and indexes.
 139 // It must hold at least 16 bits, but must also be fast to load and store.
 140 // This type, if less than 32 bits, could limit the number of possible nodes.
 141 // (To make this type platform-specific, move to globalDefinitions_xxx.hpp.)
 142 typedef unsigned int node_idx_t;
 143 
 144 
 145 #ifndef OPTO_DU_ITERATOR_ASSERT
 146 #ifdef ASSERT
 147 #define OPTO_DU_ITERATOR_ASSERT 1
 148 #else
 149 #define OPTO_DU_ITERATOR_ASSERT 0
 150 #endif
 151 #endif //OPTO_DU_ITERATOR_ASSERT
 152 
 153 #if OPTO_DU_ITERATOR_ASSERT
 154 class DUIterator;
 155 class DUIterator_Fast;
 156 class DUIterator_Last;
 157 #else
 158 typedef uint   DUIterator;
 159 typedef Node** DUIterator_Fast;
 160 typedef Node** DUIterator_Last;
 161 #endif
 162 
 163 // Node Sentinel
 164 #define NodeSentinel (Node*)-1
 165 
 166 // Unknown count frequency
 167 #define COUNT_UNKNOWN (-1.0f)
 168 
 169 //------------------------------Node-------------------------------------------
 170 // Nodes define actions in the program.  They create values, which have types.
 171 // They are both vertices in a directed graph and program primitives.  Nodes
 172 // are labeled; the label is the "opcode", the primitive function in the lambda
 173 // calculus sense that gives meaning to the Node.  Node inputs are ordered (so
 174 // that "a-b" is different from "b-a").  The inputs to a Node are the inputs to
 175 // the Node's function.  These inputs also define a Type equation for the Node.
 176 // Solving these Type equations amounts to doing dataflow analysis.
 177 // Control and data are uniformly represented in the graph.  Finally, Nodes
 178 // have a unique dense integer index which is used to index into side arrays
 179 // whenever I have phase-specific information.
 180 
 181 class Node {
 182   // Lots of restrictions on cloning Nodes
 183   Node(const Node&);            // not defined; linker error to use these
 184   Node &operator=(const Node &rhs);
 185 
 186 public:
 187   friend class Compile;
 188   #if OPTO_DU_ITERATOR_ASSERT
 189   friend class DUIterator_Common;
 190   friend class DUIterator;
 191   friend class DUIterator_Fast;
 192   friend class DUIterator_Last;
 193   #endif
 194 
 195   // Because Nodes come and go, I define an Arena of Node structures to pull
 196   // from.  This should allow fast access to node creation & deletion.  This
 197   // field is a local cache of a value defined in some "program fragment" for
 198   // which these Nodes are just a part of.
 199 
 200   // New Operator that takes a Compile pointer, this will eventually
 201   // be the "new" New operator.
 202   inline void* operator new( size_t x, Compile* C) {
 203     Node* n = (Node*)C->node_arena()->Amalloc_D(x);
 204 #ifdef ASSERT
 205     n->_in = (Node**)n; // magic cookie for assertion check
 206 #endif
 207     n->_out = (Node**)C;
 208     return (void*)n;
 209   }
 210 
 211   // New Operator that takes a Compile pointer, this will eventually
 212   // be the "new" New operator.
 213   inline void* operator new( size_t x, Compile* C, int y) {
 214     Node* n = (Node*)C->node_arena()->Amalloc_D(x + y*sizeof(void*));
 215     n->_in = (Node**)(((char*)n) + x);
 216 #ifdef ASSERT
 217     n->_in[y-1] = n; // magic cookie for assertion check
 218 #endif
 219     n->_out = (Node**)C;
 220     return (void*)n;
 221   }
 222 
 223   // Delete is a NOP
 224   void operator delete( void *ptr ) {}
 225   // Fancy destructor; eagerly attempt to reclaim Node numberings and storage
 226   void destruct();
 227 
 228   // Create a new Node.  Required is the number is of inputs required for
 229   // semantic correctness.
 230   Node( uint required );
 231 
 232   // Create a new Node with given input edges.
 233   // This version requires use of the "edge-count" new.
 234   // E.g.  new (C,3) FooNode( C, NULL, left, right );
 235   Node( Node *n0 );
 236   Node( Node *n0, Node *n1 );
 237   Node( Node *n0, Node *n1, Node *n2 );
 238   Node( Node *n0, Node *n1, Node *n2, Node *n3 );
 239   Node( Node *n0, Node *n1, Node *n2, Node *n3, Node *n4 );
 240   Node( Node *n0, Node *n1, Node *n2, Node *n3, Node *n4, Node *n5 );
 241   Node( Node *n0, Node *n1, Node *n2, Node *n3,
 242             Node *n4, Node *n5, Node *n6 );
 243 
 244   // Clone an inherited Node given only the base Node type.
 245   Node* clone() const;
 246 
 247   // Clone a Node, immediately supplying one or two new edges.
 248   // The first and second arguments, if non-null, replace in(1) and in(2),
 249   // respectively.
 250   Node* clone_with_data_edge(Node* in1, Node* in2 = NULL) const {
 251     Node* nn = clone();
 252     if (in1 != NULL)  nn->set_req(1, in1);
 253     if (in2 != NULL)  nn->set_req(2, in2);
 254     return nn;
 255   }
 256 
 257 private:
 258   // Shared setup for the above constructors.
 259   // Handles all interactions with Compile::current.
 260   // Puts initial values in all Node fields except _idx.
 261   // Returns the initial value for _idx, which cannot
 262   // be initialized by assignment.
 263   inline int Init(int req, Compile* C);
 264 
 265 //----------------- input edge handling
 266 protected:
 267   friend class PhaseCFG;        // Access to address of _in array elements
 268   Node **_in;                   // Array of use-def references to Nodes
 269   Node **_out;                  // Array of def-use references to Nodes
 270 
 271   // Input edges are split into two categories.  Required edges are required
 272   // for semantic correctness; order is important and NULLs are allowed.
 273   // Precedence edges are used to help determine execution order and are
 274   // added, e.g., for scheduling purposes.  They are unordered and not
 275   // duplicated; they have no embedded NULLs.  Edges from 0 to _cnt-1
 276   // are required, from _cnt to _max-1 are precedence edges.
 277   node_idx_t _cnt;              // Total number of required Node inputs.
 278 
 279   node_idx_t _max;              // Actual length of input array.
 280 
 281   // Output edges are an unordered list of def-use edges which exactly
 282   // correspond to required input edges which point from other nodes
 283   // to this one.  Thus the count of the output edges is the number of
 284   // users of this node.
 285   node_idx_t _outcnt;           // Total number of Node outputs.
 286 
 287   node_idx_t _outmax;           // Actual length of output array.
 288 
 289   // Grow the actual input array to the next larger power-of-2 bigger than len.
 290   void grow( uint len );
 291   // Grow the output array to the next larger power-of-2 bigger than len.
 292   void out_grow( uint len );
 293 
 294  public:
 295   // Each Node is assigned a unique small/dense number.  This number is used
 296   // to index into auxiliary arrays of data and bitvectors.
 297   // It is declared const to defend against inadvertant assignment,
 298   // since it is used by clients as a naked field.
 299   const node_idx_t _idx;
 300 
 301   // Get the (read-only) number of input edges
 302   uint req() const { return _cnt; }
 303   uint len() const { return _max; }
 304   // Get the (read-only) number of output edges
 305   uint outcnt() const { return _outcnt; }
 306 
 307 #if OPTO_DU_ITERATOR_ASSERT
 308   // Iterate over the out-edges of this node.  Deletions are illegal.
 309   inline DUIterator outs() const;
 310   // Use this when the out array might have changed to suppress asserts.
 311   inline DUIterator& refresh_out_pos(DUIterator& i) const;
 312   // Does the node have an out at this position?  (Used for iteration.)
 313   inline bool has_out(DUIterator& i) const;
 314   inline Node*    out(DUIterator& i) const;
 315   // Iterate over the out-edges of this node.  All changes are illegal.
 316   inline DUIterator_Fast fast_outs(DUIterator_Fast& max) const;
 317   inline Node*    fast_out(DUIterator_Fast& i) const;
 318   // Iterate over the out-edges of this node, deleting one at a time.
 319   inline DUIterator_Last last_outs(DUIterator_Last& min) const;
 320   inline Node*    last_out(DUIterator_Last& i) const;
 321   // The inline bodies of all these methods are after the iterator definitions.
 322 #else
 323   // Iterate over the out-edges of this node.  Deletions are illegal.
 324   // This iteration uses integral indexes, to decouple from array reallocations.
 325   DUIterator outs() const  { return 0; }
 326   // Use this when the out array might have changed to suppress asserts.
 327   DUIterator refresh_out_pos(DUIterator i) const { return i; }
 328 
 329   // Reference to the i'th output Node.  Error if out of bounds.
 330   Node*    out(DUIterator i) const { assert(i < _outcnt, "oob"); return _out[i]; }
 331   // Does the node have an out at this position?  (Used for iteration.)
 332   bool has_out(DUIterator i) const { return i < _outcnt; }
 333 
 334   // Iterate over the out-edges of this node.  All changes are illegal.
 335   // This iteration uses a pointer internal to the out array.
 336   DUIterator_Fast fast_outs(DUIterator_Fast& max) const {
 337     Node** out = _out;
 338     // Assign a limit pointer to the reference argument:
 339     max = out + (ptrdiff_t)_outcnt;
 340     // Return the base pointer:
 341     return out;
 342   }
 343   Node*    fast_out(DUIterator_Fast i) const  { return *i; }
 344   // Iterate over the out-edges of this node, deleting one at a time.
 345   // This iteration uses a pointer internal to the out array.
 346   DUIterator_Last last_outs(DUIterator_Last& min) const {
 347     Node** out = _out;
 348     // Assign a limit pointer to the reference argument:
 349     min = out;
 350     // Return the pointer to the start of the iteration:
 351     return out + (ptrdiff_t)_outcnt - 1;
 352   }
 353   Node*    last_out(DUIterator_Last i) const  { return *i; }
 354 #endif
 355 
 356   // Reference to the i'th input Node.  Error if out of bounds.
 357   Node* in(uint i) const { assert(i < _max,"oob"); return _in[i]; }
 358   // Reference to the i'th output Node.  Error if out of bounds.
 359   // Use this accessor sparingly.  We are going trying to use iterators instead.
 360   Node* raw_out(uint i) const { assert(i < _outcnt,"oob"); return _out[i]; }
 361   // Return the unique out edge.
 362   Node* unique_out() const { assert(_outcnt==1,"not unique"); return _out[0]; }
 363   // Delete out edge at position 'i' by moving last out edge to position 'i'
 364   void  raw_del_out(uint i) {
 365     assert(i < _outcnt,"oob");
 366     assert(_outcnt > 0,"oob");
 367     #if OPTO_DU_ITERATOR_ASSERT
 368     // Record that a change happened here.
 369     debug_only(_last_del = _out[i]; ++_del_tick);
 370     #endif
 371     _out[i] = _out[--_outcnt];
 372     // Smash the old edge so it can't be used accidentally.
 373     debug_only(_out[_outcnt] = (Node *)(uintptr_t)0xdeadbeef);
 374   }
 375 
 376 #ifdef ASSERT
 377   bool is_dead() const;
 378 #define is_not_dead(n) ((n) == NULL || !VerifyIterativeGVN || !((n)->is_dead()))
 379 #endif
 380 
 381   // Set a required input edge, also updates corresponding output edge
 382   void add_req( Node *n ); // Append a NEW required input
 383   void add_req_batch( Node* n, uint m ); // Append m NEW required inputs (all n).
 384   void del_req( uint idx ); // Delete required edge & compact
 385   void ins_req( uint i, Node *n ); // Insert a NEW required input
 386   void set_req( uint i, Node *n ) {
 387     assert( is_not_dead(n), "can not use dead node");
 388     assert( i < _cnt, "oob");
 389     assert( !VerifyHashTableKeys || _hash_lock == 0,
 390             "remove node from hash table before modifying it");
 391     Node** p = &_in[i];    // cache this._in, across the del_out call
 392     if (*p != NULL)  (*p)->del_out((Node *)this);
 393     (*p) = n;
 394     if (n != NULL)      n->add_out((Node *)this);
 395   }
 396   // Light version of set_req() to init inputs after node creation.
 397   void init_req( uint i, Node *n ) {
 398     assert( i == 0 && this == n ||
 399             is_not_dead(n), "can not use dead node");
 400     assert( i < _cnt, "oob");
 401     assert( !VerifyHashTableKeys || _hash_lock == 0,
 402             "remove node from hash table before modifying it");
 403     assert( _in[i] == NULL, "sanity");
 404     _in[i] = n;
 405     if (n != NULL)      n->add_out((Node *)this);
 406   }
 407   // Find first occurrence of n among my edges:
 408   int find_edge(Node* n);
 409   int replace_edge(Node* old, Node* neww);
 410   // NULL out all inputs to eliminate incoming Def-Use edges.
 411   // Return the number of edges between 'n' and 'this'
 412   int  disconnect_inputs(Node *n);
 413 
 414   // Quickly, return true if and only if I am Compile::current()->top().
 415   bool is_top() const {
 416     assert((this == (Node*) Compile::current()->top()) == (_out == NULL), "");
 417     return (_out == NULL);
 418   }
 419   // Reaffirm invariants for is_top.  (Only from Compile::set_cached_top_node.)
 420   void setup_is_top();
 421 
 422   // Strip away casting.  (It is depth-limited.)
 423   Node* uncast() const;
 424 
 425 private:
 426   static Node* uncast_helper(const Node* n);
 427 
 428   // Add an output edge to the end of the list
 429   void add_out( Node *n ) {
 430     if (is_top())  return;
 431     if( _outcnt == _outmax ) out_grow(_outcnt);
 432     _out[_outcnt++] = n;
 433   }
 434   // Delete an output edge
 435   void del_out( Node *n ) {
 436     if (is_top())  return;
 437     Node** outp = &_out[_outcnt];
 438     // Find and remove n
 439     do {
 440       assert(outp > _out, "Missing Def-Use edge");
 441     } while (*--outp != n);
 442     *outp = _out[--_outcnt];
 443     // Smash the old edge so it can't be used accidentally.
 444     debug_only(_out[_outcnt] = (Node *)(uintptr_t)0xdeadbeef);
 445     // Record that a change happened here.
 446     #if OPTO_DU_ITERATOR_ASSERT
 447     debug_only(_last_del = n; ++_del_tick);
 448     #endif
 449   }
 450 
 451 public:
 452   // Globally replace this node by a given new node, updating all uses.
 453   void replace_by(Node* new_node);
 454   // Globally replace this node by a given new node, updating all uses
 455   // and cutting input edges of old node.
 456   void subsume_by(Node* new_node) {
 457     replace_by(new_node);
 458     disconnect_inputs(NULL);
 459   }
 460   void set_req_X( uint i, Node *n, PhaseIterGVN *igvn );
 461   // Find the one non-null required input.  RegionNode only
 462   Node *nonnull_req() const;
 463   // Add or remove precedence edges
 464   void add_prec( Node *n );
 465   void rm_prec( uint i );
 466   void set_prec( uint i, Node *n ) {
 467     assert( is_not_dead(n), "can not use dead node");
 468     assert( i >= _cnt, "not a precedence edge");
 469     if (_in[i] != NULL) _in[i]->del_out((Node *)this);
 470     _in[i] = n;
 471     if (n != NULL) n->add_out((Node *)this);
 472   }
 473   // Set this node's index, used by cisc_version to replace current node
 474   void set_idx(uint new_idx) {
 475     const node_idx_t* ref = &_idx;
 476     *(node_idx_t*)ref = new_idx;
 477   }
 478   // Swap input edge order.  (Edge indexes i1 and i2 are usually 1 and 2.)
 479   void swap_edges(uint i1, uint i2) {
 480     debug_only(uint check_hash = (VerifyHashTableKeys && _hash_lock) ? hash() : NO_HASH);
 481     // Def-Use info is unchanged
 482     Node* n1 = in(i1);
 483     Node* n2 = in(i2);
 484     _in[i1] = n2;
 485     _in[i2] = n1;
 486     // If this node is in the hash table, make sure it doesn't need a rehash.
 487     assert(check_hash == NO_HASH || check_hash == hash(), "edge swap must preserve hash code");
 488   }
 489 
 490   // Iterators over input Nodes for a Node X are written as:
 491   // for( i = 0; i < X.req(); i++ ) ... X[i] ...
 492   // NOTE: Required edges can contain embedded NULL pointers.
 493 
 494 //----------------- Other Node Properties
 495 
 496   // Generate class id for some ideal nodes to avoid virtual query
 497   // methods is_<Node>().
 498   // Class id is the set of bits corresponded to the node class and all its
 499   // super classes so that queries for super classes are also valid.
 500   // Subclasses of the same super class have different assigned bit
 501   // (the third parameter in the macro DEFINE_CLASS_ID).
 502   // Classes with deeper hierarchy are declared first.
 503   // Classes with the same hierarchy depth are sorted by usage frequency.
 504   //
 505   // The query method masks the bits to cut off bits of subclasses
 506   // and then compare the result with the class id
 507   // (see the macro DEFINE_CLASS_QUERY below).
 508   //
 509   //  Class_MachCall=30, ClassMask_MachCall=31
 510   // 12               8               4               0
 511   //  0   0   0   0   0   0   0   0   1   1   1   1   0
 512   //                                  |   |   |   |
 513   //                                  |   |   |   Bit_Mach=2
 514   //                                  |   |   Bit_MachReturn=4
 515   //                                  |   Bit_MachSafePoint=8
 516   //                                  Bit_MachCall=16
 517   //
 518   //  Class_CountedLoop=56, ClassMask_CountedLoop=63
 519   // 12               8               4               0
 520   //  0   0   0   0   0   0   0   1   1   1   0   0   0
 521   //                              |   |   |
 522   //                              |   |   Bit_Region=8
 523   //                              |   Bit_Loop=16
 524   //                              Bit_CountedLoop=32
 525 
 526   #define DEFINE_CLASS_ID(cl, supcl, subn) \
 527   Bit_##cl = (Class_##supcl == 0) ? 1 << subn : (Bit_##supcl) << (1 + subn) , \
 528   Class_##cl = Class_##supcl + Bit_##cl , \
 529   ClassMask_##cl = ((Bit_##cl << 1) - 1) ,
 530 
 531   // This enum is used only for C2 ideal and mach nodes with is_<node>() methods
 532   // so that it's values fits into 16 bits.
 533   enum NodeClasses {
 534     Bit_Node   = 0x0000,
 535     Class_Node = 0x0000,
 536     ClassMask_Node = 0xFFFF,
 537 
 538     DEFINE_CLASS_ID(Multi, Node, 0)
 539       DEFINE_CLASS_ID(SafePoint, Multi, 0)
 540         DEFINE_CLASS_ID(Call,      SafePoint, 0)
 541           DEFINE_CLASS_ID(CallJava,         Call, 0)
 542             DEFINE_CLASS_ID(CallStaticJava,   CallJava, 0)
 543             DEFINE_CLASS_ID(CallDynamicJava,  CallJava, 1)
 544           DEFINE_CLASS_ID(CallRuntime,      Call, 1)
 545             DEFINE_CLASS_ID(CallLeaf,         CallRuntime, 0)
 546           DEFINE_CLASS_ID(Allocate,         Call, 2)
 547             DEFINE_CLASS_ID(AllocateArray,    Allocate, 0)
 548           DEFINE_CLASS_ID(AbstractLock,     Call, 3)
 549             DEFINE_CLASS_ID(Lock,             AbstractLock, 0)
 550             DEFINE_CLASS_ID(Unlock,           AbstractLock, 1)
 551       DEFINE_CLASS_ID(MultiBranch, Multi, 1)
 552         DEFINE_CLASS_ID(PCTable,     MultiBranch, 0)
 553           DEFINE_CLASS_ID(Catch,       PCTable, 0)
 554           DEFINE_CLASS_ID(Jump,        PCTable, 1)
 555         DEFINE_CLASS_ID(If,          MultiBranch, 1)
 556           DEFINE_CLASS_ID(CountedLoopEnd, If, 0)
 557         DEFINE_CLASS_ID(NeverBranch, MultiBranch, 2)
 558       DEFINE_CLASS_ID(Start,       Multi, 2)
 559       DEFINE_CLASS_ID(MemBar,      Multi, 3)
 560         DEFINE_CLASS_ID(Initialize,    MemBar, 0)
 561 
 562     DEFINE_CLASS_ID(Mach,  Node, 1)
 563       DEFINE_CLASS_ID(MachReturn, Mach, 0)
 564         DEFINE_CLASS_ID(MachSafePoint, MachReturn, 0)
 565           DEFINE_CLASS_ID(MachCall, MachSafePoint, 0)
 566             DEFINE_CLASS_ID(MachCallJava,         MachCall, 0)
 567               DEFINE_CLASS_ID(MachCallStaticJava,   MachCallJava, 0)
 568               DEFINE_CLASS_ID(MachCallDynamicJava,  MachCallJava, 1)
 569             DEFINE_CLASS_ID(MachCallRuntime,      MachCall, 1)
 570               DEFINE_CLASS_ID(MachCallLeaf,         MachCallRuntime, 0)
 571       DEFINE_CLASS_ID(MachSpillCopy,    Mach, 1)
 572       DEFINE_CLASS_ID(MachNullCheck,    Mach, 2)
 573       DEFINE_CLASS_ID(MachIf,           Mach, 3)
 574       DEFINE_CLASS_ID(MachTemp,         Mach, 4)
 575       DEFINE_CLASS_ID(MachConstantBase, Mach, 5)
 576       DEFINE_CLASS_ID(MachConstant,     Mach, 6)
 577 
 578     DEFINE_CLASS_ID(Proj,  Node, 2)
 579       DEFINE_CLASS_ID(CatchProj, Proj, 0)
 580       DEFINE_CLASS_ID(JumpProj,  Proj, 1)
 581       DEFINE_CLASS_ID(IfTrue,    Proj, 2)
 582       DEFINE_CLASS_ID(IfFalse,   Proj, 3)
 583       DEFINE_CLASS_ID(Parm,      Proj, 4)
 584 
 585     DEFINE_CLASS_ID(Region, Node, 3)
 586       DEFINE_CLASS_ID(Loop, Region, 0)
 587         DEFINE_CLASS_ID(Root,        Loop, 0)
 588         DEFINE_CLASS_ID(CountedLoop, Loop, 1)
 589 
 590     DEFINE_CLASS_ID(Sub,   Node, 4)
 591       DEFINE_CLASS_ID(Cmp,   Sub, 0)
 592         DEFINE_CLASS_ID(FastLock,   Cmp, 0)
 593         DEFINE_CLASS_ID(FastUnlock, Cmp, 1)
 594 
 595     DEFINE_CLASS_ID(Type,  Node, 5)
 596       DEFINE_CLASS_ID(Phi,   Type, 0)
 597       DEFINE_CLASS_ID(ConstraintCast, Type, 1)
 598       DEFINE_CLASS_ID(CheckCastPP, Type, 2)
 599       DEFINE_CLASS_ID(CMove, Type, 3)
 600       DEFINE_CLASS_ID(SafePointScalarObject, Type, 4)
 601       DEFINE_CLASS_ID(DecodeN, Type, 5)
 602       DEFINE_CLASS_ID(EncodeP, Type, 6)
 603 
 604     DEFINE_CLASS_ID(Mem,   Node, 6)
 605       DEFINE_CLASS_ID(Load,  Mem, 0)
 606       DEFINE_CLASS_ID(Store, Mem, 1)
 607       DEFINE_CLASS_ID(LoadStore, Mem, 2)
 608 
 609     DEFINE_CLASS_ID(MergeMem, Node, 7)
 610     DEFINE_CLASS_ID(Bool,     Node, 8)
 611     DEFINE_CLASS_ID(AddP,     Node, 9)
 612     DEFINE_CLASS_ID(BoxLock,  Node, 10)
 613     DEFINE_CLASS_ID(Add,      Node, 11)
 614     DEFINE_CLASS_ID(Mul,      Node, 12)
 615     DEFINE_CLASS_ID(ClearArray, Node, 13)
 616 
 617     _max_classes  = ClassMask_ClearArray
 618   };
 619   #undef DEFINE_CLASS_ID
 620 
 621   // Flags are sorted by usage frequency.
 622   enum NodeFlags {
 623     Flag_is_Copy             = 0x01, // should be first bit to avoid shift
 624     Flag_is_Call             = Flag_is_Copy << 1,
 625     Flag_rematerialize       = Flag_is_Call << 1,
 626     Flag_needs_anti_dependence_check = Flag_rematerialize << 1,
 627     Flag_is_macro            = Flag_needs_anti_dependence_check << 1,
 628     Flag_is_Con              = Flag_is_macro << 1,
 629     Flag_is_cisc_alternate   = Flag_is_Con << 1,
 630     Flag_is_Branch           = Flag_is_cisc_alternate << 1,
 631     Flag_is_block_start      = Flag_is_Branch << 1,
 632     Flag_is_Goto             = Flag_is_block_start << 1,
 633     Flag_is_dead_loop_safe   = Flag_is_Goto << 1,
 634     Flag_may_be_short_branch = Flag_is_dead_loop_safe << 1,
 635     Flag_is_safepoint_node   = Flag_may_be_short_branch << 1,
 636     Flag_is_pc_relative      = Flag_is_safepoint_node << 1,
 637     Flag_is_Vector           = Flag_is_pc_relative << 1,
 638     _max_flags = (Flag_is_Vector << 1) - 1 // allow flags combination
 639   };
 640 
 641 private:
 642   jushort _class_id;
 643   jushort _flags;
 644 
 645 protected:
 646   // These methods should be called from constructors only.
 647   void init_class_id(jushort c) {
 648     assert(c <= _max_classes, "invalid node class");
 649     _class_id = c; // cast out const
 650   }
 651   void init_flags(jushort fl) {
 652     assert(fl <= _max_flags, "invalid node flag");
 653     _flags |= fl;
 654   }
 655   void clear_flag(jushort fl) {
 656     assert(fl <= _max_flags, "invalid node flag");
 657     _flags &= ~fl;
 658   }
 659 
 660 public:
 661   const jushort class_id() const { return _class_id; }
 662 
 663   const jushort flags() const { return _flags; }
 664 
 665   // Return a dense integer opcode number
 666   virtual int Opcode() const;
 667 
 668   // Virtual inherited Node size
 669   virtual uint size_of() const;
 670 
 671   // Other interesting Node properties
 672 
 673   // Special case: is_Call() returns true for both CallNode and MachCallNode.
 674   bool is_Call() const {
 675     return (_flags & Flag_is_Call) != 0;
 676   }
 677 
 678   CallNode* isa_Call() const {
 679     return is_Call() ? as_Call() : NULL;
 680   }
 681 
 682   CallNode *as_Call() const { // Only for CallNode (not for MachCallNode)
 683     assert((_class_id & ClassMask_Call) == Class_Call, "invalid node class");
 684     return (CallNode*)this;
 685   }
 686 
 687   #define DEFINE_CLASS_QUERY(type)                           \
 688   bool is_##type() const {                                   \
 689     return ((_class_id & ClassMask_##type) == Class_##type); \
 690   }                                                          \
 691   type##Node *as_##type() const {                            \
 692     assert(is_##type(), "invalid node class");               \
 693     return (type##Node*)this;                                \
 694   }                                                          \
 695   type##Node* isa_##type() const {                           \
 696     return (is_##type()) ? as_##type() : NULL;               \
 697   }
 698 
 699   DEFINE_CLASS_QUERY(AbstractLock)
 700   DEFINE_CLASS_QUERY(Add)
 701   DEFINE_CLASS_QUERY(AddP)
 702   DEFINE_CLASS_QUERY(Allocate)
 703   DEFINE_CLASS_QUERY(AllocateArray)
 704   DEFINE_CLASS_QUERY(Bool)
 705   DEFINE_CLASS_QUERY(BoxLock)
 706   DEFINE_CLASS_QUERY(CallDynamicJava)
 707   DEFINE_CLASS_QUERY(CallJava)
 708   DEFINE_CLASS_QUERY(CallLeaf)
 709   DEFINE_CLASS_QUERY(CallRuntime)
 710   DEFINE_CLASS_QUERY(CallStaticJava)
 711   DEFINE_CLASS_QUERY(Catch)
 712   DEFINE_CLASS_QUERY(CatchProj)
 713   DEFINE_CLASS_QUERY(CheckCastPP)
 714   DEFINE_CLASS_QUERY(ConstraintCast)
 715   DEFINE_CLASS_QUERY(ClearArray)
 716   DEFINE_CLASS_QUERY(CMove)
 717   DEFINE_CLASS_QUERY(Cmp)
 718   DEFINE_CLASS_QUERY(CountedLoop)
 719   DEFINE_CLASS_QUERY(CountedLoopEnd)
 720   DEFINE_CLASS_QUERY(DecodeN)
 721   DEFINE_CLASS_QUERY(EncodeP)
 722   DEFINE_CLASS_QUERY(FastLock)
 723   DEFINE_CLASS_QUERY(FastUnlock)
 724   DEFINE_CLASS_QUERY(If)
 725   DEFINE_CLASS_QUERY(IfFalse)
 726   DEFINE_CLASS_QUERY(IfTrue)
 727   DEFINE_CLASS_QUERY(Initialize)
 728   DEFINE_CLASS_QUERY(Jump)
 729   DEFINE_CLASS_QUERY(JumpProj)
 730   DEFINE_CLASS_QUERY(Load)
 731   DEFINE_CLASS_QUERY(LoadStore)
 732   DEFINE_CLASS_QUERY(Lock)
 733   DEFINE_CLASS_QUERY(Loop)
 734   DEFINE_CLASS_QUERY(Mach)
 735   DEFINE_CLASS_QUERY(MachCall)
 736   DEFINE_CLASS_QUERY(MachCallDynamicJava)
 737   DEFINE_CLASS_QUERY(MachCallJava)
 738   DEFINE_CLASS_QUERY(MachCallLeaf)
 739   DEFINE_CLASS_QUERY(MachCallRuntime)
 740   DEFINE_CLASS_QUERY(MachCallStaticJava)
 741   DEFINE_CLASS_QUERY(MachConstantBase)
 742   DEFINE_CLASS_QUERY(MachConstant)
 743   DEFINE_CLASS_QUERY(MachIf)
 744   DEFINE_CLASS_QUERY(MachNullCheck)
 745   DEFINE_CLASS_QUERY(MachReturn)
 746   DEFINE_CLASS_QUERY(MachSafePoint)
 747   DEFINE_CLASS_QUERY(MachSpillCopy)
 748   DEFINE_CLASS_QUERY(MachTemp)
 749   DEFINE_CLASS_QUERY(Mem)
 750   DEFINE_CLASS_QUERY(MemBar)
 751   DEFINE_CLASS_QUERY(MergeMem)
 752   DEFINE_CLASS_QUERY(Mul)
 753   DEFINE_CLASS_QUERY(Multi)
 754   DEFINE_CLASS_QUERY(MultiBranch)
 755   DEFINE_CLASS_QUERY(Parm)
 756   DEFINE_CLASS_QUERY(PCTable)
 757   DEFINE_CLASS_QUERY(Phi)
 758   DEFINE_CLASS_QUERY(Proj)
 759   DEFINE_CLASS_QUERY(Region)
 760   DEFINE_CLASS_QUERY(Root)
 761   DEFINE_CLASS_QUERY(SafePoint)
 762   DEFINE_CLASS_QUERY(SafePointScalarObject)
 763   DEFINE_CLASS_QUERY(Start)
 764   DEFINE_CLASS_QUERY(Store)
 765   DEFINE_CLASS_QUERY(Sub)
 766   DEFINE_CLASS_QUERY(Type)
 767   DEFINE_CLASS_QUERY(Unlock)
 768 
 769   #undef DEFINE_CLASS_QUERY
 770 
 771   // duplicate of is_MachSpillCopy()
 772   bool is_SpillCopy () const {
 773     return ((_class_id & ClassMask_MachSpillCopy) == Class_MachSpillCopy);
 774   }
 775 
 776   bool is_Con () const { return (_flags & Flag_is_Con) != 0; }
 777   bool is_Goto() const { return (_flags & Flag_is_Goto) != 0; }
 778   // The data node which is safe to leave in dead loop during IGVN optimization.
 779   bool is_dead_loop_safe() const {
 780     return is_Phi() || (is_Proj() && in(0) == NULL) ||
 781            ((_flags & (Flag_is_dead_loop_safe | Flag_is_Con)) != 0 &&
 782             (!is_Proj() || !in(0)->is_Allocate()));
 783   }
 784 
 785   // is_Copy() returns copied edge index (0 or 1)
 786   uint is_Copy() const { return (_flags & Flag_is_Copy); }
 787 
 788   virtual bool is_CFG() const { return false; }
 789 
 790   // If this node is control-dependent on a test, can it be
 791   // rerouted to a dominating equivalent test?  This is usually
 792   // true of non-CFG nodes, but can be false for operations which
 793   // depend for their correct sequencing on more than one test.
 794   // (In that case, hoisting to a dominating test may silently
 795   // skip some other important test.)
 796   virtual bool depends_only_on_test() const { assert(!is_CFG(), ""); return true; };
 797 
 798   // defined for MachNodes that match 'If' | 'Goto' | 'CountedLoopEnd'
 799   bool is_Branch() const { return (_flags & Flag_is_Branch) != 0; }
 800 
 801   // When building basic blocks, I need to have a notion of block beginning
 802   // Nodes, next block selector Nodes (block enders), and next block
 803   // projections.  These calls need to work on their machine equivalents.  The
 804   // Ideal beginning Nodes are RootNode, RegionNode and StartNode.
 805   bool is_block_start() const {
 806     if ( is_Region() )
 807       return this == (const Node*)in(0);
 808     else
 809       return (_flags & Flag_is_block_start) != 0;
 810   }
 811 
 812   // The Ideal control projection Nodes are IfTrue/IfFalse, JumpProjNode, Root,
 813   // Goto and Return.  This call also returns the block ending Node.
 814   virtual const Node *is_block_proj() const;
 815 
 816   // The node is a "macro" node which needs to be expanded before matching
 817   bool is_macro() const { return (_flags & Flag_is_macro) != 0; }
 818 
 819   // Value is a vector of primitive values
 820   bool is_Vector() const { return (_flags & Flag_is_Vector) != 0; }
 821 
 822 //----------------- Optimization
 823 
 824   // Get the worst-case Type output for this Node.
 825   virtual const class Type *bottom_type() const;
 826 
 827   // If we find a better type for a node, try to record it permanently.
 828   // Return true if this node actually changed.
 829   // Be sure to do the hash_delete game in the "rehash" variant.
 830   void raise_bottom_type(const Type* new_type);
 831 
 832   // Get the address type with which this node uses and/or defs memory,
 833   // or NULL if none.  The address type is conservatively wide.
 834   // Returns non-null for calls, membars, loads, stores, etc.
 835   // Returns TypePtr::BOTTOM if the node touches memory "broadly".
 836   virtual const class TypePtr *adr_type() const { return NULL; }
 837 
 838   // Return an existing node which computes the same function as this node.
 839   // The optimistic combined algorithm requires this to return a Node which
 840   // is a small number of steps away (e.g., one of my inputs).
 841   virtual Node *Identity( PhaseTransform *phase );
 842 
 843   // Return the set of values this Node can take on at runtime.
 844   virtual const Type *Value( PhaseTransform *phase ) const;
 845 
 846   // Return a node which is more "ideal" than the current node.
 847   // The invariants on this call are subtle.  If in doubt, read the
 848   // treatise in node.cpp above the default implemention AND TEST WITH
 849   // +VerifyIterativeGVN!
 850   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
 851 
 852   // Some nodes have specific Ideal subgraph transformations only if they are
 853   // unique users of specific nodes. Such nodes should be put on IGVN worklist
 854   // for the transformations to happen.
 855   bool has_special_unique_user() const;
 856 
 857   // Skip Proj and CatchProj nodes chains. Check for Null and Top.
 858   Node* find_exact_control(Node* ctrl);
 859 
 860   // Check if 'this' node dominates or equal to 'sub'.
 861   bool dominates(Node* sub, Node_List &nlist);
 862 
 863 protected:
 864   bool remove_dead_region(PhaseGVN *phase, bool can_reshape);
 865 public:
 866 
 867   // Idealize graph, using DU info.  Done after constant propagation
 868   virtual Node *Ideal_DU_postCCP( PhaseCCP *ccp );
 869 
 870   // See if there is valid pipeline info
 871   static  const Pipeline *pipeline_class();
 872   virtual const Pipeline *pipeline() const;
 873 
 874   // Compute the latency from the def to this instruction of the ith input node
 875   uint latency(uint i);
 876 
 877   // Hash & compare functions, for pessimistic value numbering
 878 
 879   // If the hash function returns the special sentinel value NO_HASH,
 880   // the node is guaranteed never to compare equal to any other node.
 881   // If we accidentally generate a hash with value NO_HASH the node
 882   // won't go into the table and we'll lose a little optimization.
 883   enum { NO_HASH = 0 };
 884   virtual uint hash() const;
 885   virtual uint cmp( const Node &n ) const;
 886 
 887   // Operation appears to be iteratively computed (such as an induction variable)
 888   // It is possible for this operation to return false for a loop-varying
 889   // value, if it appears (by local graph inspection) to be computed by a simple conditional.
 890   bool is_iteratively_computed();
 891 
 892   // Determine if a node is Counted loop induction variable.
 893   // The method is defined in loopnode.cpp.
 894   const Node* is_loop_iv() const;
 895 
 896   // Return a node with opcode "opc" and same inputs as "this" if one can
 897   // be found; Otherwise return NULL;
 898   Node* find_similar(int opc);
 899 
 900   // Return the unique control out if only one. Null if none or more than one.
 901   Node* unique_ctrl_out();
 902 
 903 //----------------- Code Generation
 904 
 905   // Ideal register class for Matching.  Zero means unmatched instruction
 906   // (these are cloned instead of converted to machine nodes).
 907   virtual uint ideal_reg() const;
 908 
 909   static const uint NotAMachineReg;   // must be > max. machine register
 910 
 911   // Do we Match on this edge index or not?  Generally false for Control
 912   // and true for everything else.  Weird for calls & returns.
 913   virtual uint match_edge(uint idx) const;
 914 
 915   // Register class output is returned in
 916   virtual const RegMask &out_RegMask() const;
 917   // Register class input is expected in
 918   virtual const RegMask &in_RegMask(uint) const;
 919   // Should we clone rather than spill this instruction?
 920   bool rematerialize() const;
 921 
 922   // Return JVM State Object if this Node carries debug info, or NULL otherwise
 923   virtual JVMState* jvms() const;
 924 
 925   // Print as assembly
 926   virtual void format( PhaseRegAlloc *, outputStream* st = tty ) const;
 927   // Emit bytes starting at parameter 'ptr'
 928   // Bump 'ptr' by the number of output bytes
 929   virtual void emit(CodeBuffer &cbuf, PhaseRegAlloc *ra_) const;
 930   // Size of instruction in bytes
 931   virtual uint size(PhaseRegAlloc *ra_) const;
 932 
 933   // Convenience function to extract an integer constant from a node.
 934   // If it is not an integer constant (either Con, CastII, or Mach),
 935   // return value_if_unknown.
 936   jint find_int_con(jint value_if_unknown) const {
 937     const TypeInt* t = find_int_type();
 938     return (t != NULL && t->is_con()) ? t->get_con() : value_if_unknown;
 939   }
 940   // Return the constant, knowing it is an integer constant already
 941   jint get_int() const {
 942     const TypeInt* t = find_int_type();
 943     guarantee(t != NULL, "must be con");
 944     return t->get_con();
 945   }
 946   // Here's where the work is done.  Can produce non-constant int types too.
 947   const TypeInt* find_int_type() const;
 948 
 949   // Same thing for long (and intptr_t, via type.hpp):
 950   jlong get_long() const {
 951     const TypeLong* t = find_long_type();
 952     guarantee(t != NULL, "must be con");
 953     return t->get_con();
 954   }
 955   jlong find_long_con(jint value_if_unknown) const {
 956     const TypeLong* t = find_long_type();
 957     return (t != NULL && t->is_con()) ? t->get_con() : value_if_unknown;
 958   }
 959   const TypeLong* find_long_type() const;
 960 
 961   // These guys are called by code generated by ADLC:
 962   intptr_t get_ptr() const;
 963   intptr_t get_narrowcon() const;
 964   jdouble getd() const;
 965   jfloat getf() const;
 966 
 967   // Nodes which are pinned into basic blocks
 968   virtual bool pinned() const { return false; }
 969 
 970   // Nodes which use memory without consuming it, hence need antidependences
 971   // More specifically, needs_anti_dependence_check returns true iff the node
 972   // (a) does a load, and (b) does not perform a store (except perhaps to a
 973   // stack slot or some other unaliased location).
 974   bool needs_anti_dependence_check() const;
 975 
 976   // Return which operand this instruction may cisc-spill. In other words,
 977   // return operand position that can convert from reg to memory access
 978   virtual int cisc_operand() const { return AdlcVMDeps::Not_cisc_spillable; }
 979   bool is_cisc_alternate() const { return (_flags & Flag_is_cisc_alternate) != 0; }
 980 
 981 //----------------- Graph walking
 982 public:
 983   // Walk and apply member functions recursively.
 984   // Supplied (this) pointer is root.
 985   void walk(NFunc pre, NFunc post, void *env);
 986   static void nop(Node &, void*); // Dummy empty function
 987   static void packregion( Node &n, void* );
 988 private:
 989   void walk_(NFunc pre, NFunc post, void *env, VectorSet &visited);
 990 
 991 //----------------- Printing, etc
 992 public:
 993 #ifndef PRODUCT
 994   Node* find(int idx) const;         // Search the graph for the given idx.
 995   Node* find_ctrl(int idx) const;    // Search control ancestors for the given idx.
 996   void dump() const;                 // Print this node,
 997   void dump(int depth) const;        // Print this node, recursively to depth d
 998   void dump_ctrl(int depth) const;   // Print control nodes, to depth d
 999   virtual void dump_req() const;     // Print required-edge info
1000   virtual void dump_prec() const;    // Print precedence-edge info
1001   virtual void dump_out() const;     // Print the output edge info
1002   virtual void dump_spec(outputStream *st) const {}; // Print per-node info
1003   void verify_edges(Unique_Node_List &visited); // Verify bi-directional edges
1004   void verify() const;               // Check Def-Use info for my subgraph
1005   static void verify_recur(const Node *n, int verify_depth, VectorSet &old_space, VectorSet &new_space);
1006 
1007   // This call defines a class-unique string used to identify class instances
1008   virtual const char *Name() const;
1009 
1010   void dump_format(PhaseRegAlloc *ra) const; // debug access to MachNode::format(...)
1011   // RegMask Print Functions
1012   void dump_in_regmask(int idx) { in_RegMask(idx).dump(); }
1013   void dump_out_regmask() { out_RegMask().dump(); }
1014   static int _in_dump_cnt;
1015   static bool in_dump() { return _in_dump_cnt > 0; }
1016   void fast_dump() const {
1017     tty->print("%4d: %-17s", _idx, Name());
1018     for (uint i = 0; i < len(); i++)
1019       if (in(i))
1020         tty->print(" %4d", in(i)->_idx);
1021       else
1022         tty->print(" NULL");
1023     tty->print("\n");
1024   }
1025 #endif
1026 #ifdef ASSERT
1027   void verify_construction();
1028   bool verify_jvms(const JVMState* jvms) const;
1029   int  _debug_idx;                     // Unique value assigned to every node.
1030   int   debug_idx() const              { return _debug_idx; }
1031   void  set_debug_idx( int debug_idx ) { _debug_idx = debug_idx; }
1032 
1033   Node* _debug_orig;                   // Original version of this, if any.
1034   Node*  debug_orig() const            { return _debug_orig; }
1035   void   set_debug_orig(Node* orig);   // _debug_orig = orig
1036 
1037   int        _hash_lock;               // Barrier to modifications of nodes in the hash table
1038   void  enter_hash_lock() { ++_hash_lock; assert(_hash_lock < 99, "in too many hash tables?"); }
1039   void   exit_hash_lock() { --_hash_lock; assert(_hash_lock >= 0, "mispaired hash locks"); }
1040 
1041   static void init_NodeProperty();
1042 
1043   #if OPTO_DU_ITERATOR_ASSERT
1044   const Node* _last_del;               // The last deleted node.
1045   uint        _del_tick;               // Bumped when a deletion happens..
1046   #endif
1047 #endif
1048 };
1049 
1050 //-----------------------------------------------------------------------------
1051 // Iterators over DU info, and associated Node functions.
1052 
1053 #if OPTO_DU_ITERATOR_ASSERT
1054 
1055 // Common code for assertion checking on DU iterators.
1056 class DUIterator_Common VALUE_OBJ_CLASS_SPEC {
1057 #ifdef ASSERT
1058  protected:
1059   bool         _vdui;               // cached value of VerifyDUIterators
1060   const Node*  _node;               // the node containing the _out array
1061   uint         _outcnt;             // cached node->_outcnt
1062   uint         _del_tick;           // cached node->_del_tick
1063   Node*        _last;               // last value produced by the iterator
1064 
1065   void sample(const Node* node);    // used by c'tor to set up for verifies
1066   void verify(const Node* node, bool at_end_ok = false);
1067   void verify_resync();
1068   void reset(const DUIterator_Common& that);
1069 
1070 // The VDUI_ONLY macro protects code conditionalized on VerifyDUIterators
1071   #define I_VDUI_ONLY(i,x) { if ((i)._vdui) { x; } }
1072 #else
1073   #define I_VDUI_ONLY(i,x) { }
1074 #endif //ASSERT
1075 };
1076 
1077 #define VDUI_ONLY(x)     I_VDUI_ONLY(*this, x)
1078 
1079 // Default DU iterator.  Allows appends onto the out array.
1080 // Allows deletion from the out array only at the current point.
1081 // Usage:
1082 //  for (DUIterator i = x->outs(); x->has_out(i); i++) {
1083 //    Node* y = x->out(i);
1084 //    ...
1085 //  }
1086 // Compiles in product mode to a unsigned integer index, which indexes
1087 // onto a repeatedly reloaded base pointer of x->_out.  The loop predicate
1088 // also reloads x->_outcnt.  If you delete, you must perform "--i" just
1089 // before continuing the loop.  You must delete only the last-produced
1090 // edge.  You must delete only a single copy of the last-produced edge,
1091 // or else you must delete all copies at once (the first time the edge
1092 // is produced by the iterator).
1093 class DUIterator : public DUIterator_Common {
1094   friend class Node;
1095 
1096   // This is the index which provides the product-mode behavior.
1097   // Whatever the product-mode version of the system does to the
1098   // DUI index is done to this index.  All other fields in
1099   // this class are used only for assertion checking.
1100   uint         _idx;
1101 
1102   #ifdef ASSERT
1103   uint         _refresh_tick;    // Records the refresh activity.
1104 
1105   void sample(const Node* node); // Initialize _refresh_tick etc.
1106   void verify(const Node* node, bool at_end_ok = false);
1107   void verify_increment();       // Verify an increment operation.
1108   void verify_resync();          // Verify that we can back up over a deletion.
1109   void verify_finish();          // Verify that the loop terminated properly.
1110   void refresh();                // Resample verification info.
1111   void reset(const DUIterator& that);  // Resample after assignment.
1112   #endif
1113 
1114   DUIterator(const Node* node, int dummy_to_avoid_conversion)
1115     { _idx = 0;                         debug_only(sample(node)); }
1116 
1117  public:
1118   // initialize to garbage; clear _vdui to disable asserts
1119   DUIterator()
1120     { /*initialize to garbage*/         debug_only(_vdui = false); }
1121 
1122   void operator++(int dummy_to_specify_postfix_op)
1123     { _idx++;                           VDUI_ONLY(verify_increment()); }
1124 
1125   void operator--()
1126     { VDUI_ONLY(verify_resync());       --_idx; }
1127 
1128   ~DUIterator()
1129     { VDUI_ONLY(verify_finish()); }
1130 
1131   void operator=(const DUIterator& that)
1132     { _idx = that._idx;                 debug_only(reset(that)); }
1133 };
1134 
1135 DUIterator Node::outs() const
1136   { return DUIterator(this, 0); }
1137 DUIterator& Node::refresh_out_pos(DUIterator& i) const
1138   { I_VDUI_ONLY(i, i.refresh());        return i; }
1139 bool Node::has_out(DUIterator& i) const
1140   { I_VDUI_ONLY(i, i.verify(this,true));return i._idx < _outcnt; }
1141 Node*    Node::out(DUIterator& i) const
1142   { I_VDUI_ONLY(i, i.verify(this));     return debug_only(i._last=) _out[i._idx]; }
1143 
1144 
1145 // Faster DU iterator.  Disallows insertions into the out array.
1146 // Allows deletion from the out array only at the current point.
1147 // Usage:
1148 //  for (DUIterator_Fast imax, i = x->fast_outs(imax); i < imax; i++) {
1149 //    Node* y = x->fast_out(i);
1150 //    ...
1151 //  }
1152 // Compiles in product mode to raw Node** pointer arithmetic, with
1153 // no reloading of pointers from the original node x.  If you delete,
1154 // you must perform "--i; --imax" just before continuing the loop.
1155 // If you delete multiple copies of the same edge, you must decrement
1156 // imax, but not i, multiple times:  "--i, imax -= num_edges".
1157 class DUIterator_Fast : public DUIterator_Common {
1158   friend class Node;
1159   friend class DUIterator_Last;
1160 
1161   // This is the pointer which provides the product-mode behavior.
1162   // Whatever the product-mode version of the system does to the
1163   // DUI pointer is done to this pointer.  All other fields in
1164   // this class are used only for assertion checking.
1165   Node**       _outp;
1166 
1167   #ifdef ASSERT
1168   void verify(const Node* node, bool at_end_ok = false);
1169   void verify_limit();
1170   void verify_resync();
1171   void verify_relimit(uint n);
1172   void reset(const DUIterator_Fast& that);
1173   #endif
1174 
1175   // Note:  offset must be signed, since -1 is sometimes passed
1176   DUIterator_Fast(const Node* node, ptrdiff_t offset)
1177     { _outp = node->_out + offset;      debug_only(sample(node)); }
1178 
1179  public:
1180   // initialize to garbage; clear _vdui to disable asserts
1181   DUIterator_Fast()
1182     { /*initialize to garbage*/         debug_only(_vdui = false); }
1183 
1184   void operator++(int dummy_to_specify_postfix_op)
1185     { _outp++;                          VDUI_ONLY(verify(_node, true)); }
1186 
1187   void operator--()
1188     { VDUI_ONLY(verify_resync());       --_outp; }
1189 
1190   void operator-=(uint n)   // applied to the limit only
1191     { _outp -= n;           VDUI_ONLY(verify_relimit(n));  }
1192 
1193   bool operator<(DUIterator_Fast& limit) {
1194     I_VDUI_ONLY(*this, this->verify(_node, true));
1195     I_VDUI_ONLY(limit, limit.verify_limit());
1196     return _outp < limit._outp;
1197   }
1198 
1199   void operator=(const DUIterator_Fast& that)
1200     { _outp = that._outp;               debug_only(reset(that)); }
1201 };
1202 
1203 DUIterator_Fast Node::fast_outs(DUIterator_Fast& imax) const {
1204   // Assign a limit pointer to the reference argument:
1205   imax = DUIterator_Fast(this, (ptrdiff_t)_outcnt);
1206   // Return the base pointer:
1207   return DUIterator_Fast(this, 0);
1208 }
1209 Node* Node::fast_out(DUIterator_Fast& i) const {
1210   I_VDUI_ONLY(i, i.verify(this));
1211   return debug_only(i._last=) *i._outp;
1212 }
1213 
1214 
1215 // Faster DU iterator.  Requires each successive edge to be removed.
1216 // Does not allow insertion of any edges.
1217 // Usage:
1218 //  for (DUIterator_Last imin, i = x->last_outs(imin); i >= imin; i -= num_edges) {
1219 //    Node* y = x->last_out(i);
1220 //    ...
1221 //  }
1222 // Compiles in product mode to raw Node** pointer arithmetic, with
1223 // no reloading of pointers from the original node x.
1224 class DUIterator_Last : private DUIterator_Fast {
1225   friend class Node;
1226 
1227   #ifdef ASSERT
1228   void verify(const Node* node, bool at_end_ok = false);
1229   void verify_limit();
1230   void verify_step(uint num_edges);
1231   #endif
1232 
1233   // Note:  offset must be signed, since -1 is sometimes passed
1234   DUIterator_Last(const Node* node, ptrdiff_t offset)
1235     : DUIterator_Fast(node, offset) { }
1236 
1237   void operator++(int dummy_to_specify_postfix_op) {} // do not use
1238   void operator<(int)                              {} // do not use
1239 
1240  public:
1241   DUIterator_Last() { }
1242   // initialize to garbage
1243 
1244   void operator--()
1245     { _outp--;              VDUI_ONLY(verify_step(1));  }
1246 
1247   void operator-=(uint n)
1248     { _outp -= n;           VDUI_ONLY(verify_step(n));  }
1249 
1250   bool operator>=(DUIterator_Last& limit) {
1251     I_VDUI_ONLY(*this, this->verify(_node, true));
1252     I_VDUI_ONLY(limit, limit.verify_limit());
1253     return _outp >= limit._outp;
1254   }
1255 
1256   void operator=(const DUIterator_Last& that)
1257     { DUIterator_Fast::operator=(that); }
1258 };
1259 
1260 DUIterator_Last Node::last_outs(DUIterator_Last& imin) const {
1261   // Assign a limit pointer to the reference argument:
1262   imin = DUIterator_Last(this, 0);
1263   // Return the initial pointer:
1264   return DUIterator_Last(this, (ptrdiff_t)_outcnt - 1);
1265 }
1266 Node* Node::last_out(DUIterator_Last& i) const {
1267   I_VDUI_ONLY(i, i.verify(this));
1268   return debug_only(i._last=) *i._outp;
1269 }
1270 
1271 #endif //OPTO_DU_ITERATOR_ASSERT
1272 
1273 #undef I_VDUI_ONLY
1274 #undef VDUI_ONLY
1275 
1276 // An Iterator that truly follows the iterator pattern.  Doesn't
1277 // support deletion but could be made to.
1278 //
1279 //   for (SimpleDUIterator i(n); i.has_next(); i.next()) {
1280 //     Node* m = i.get();
1281 //
1282 class SimpleDUIterator : public StackObj {
1283  private:
1284   Node* node;
1285   DUIterator_Fast i;
1286   DUIterator_Fast imax;
1287  public:
1288   SimpleDUIterator(Node* n): node(n), i(n->fast_outs(imax)) {}
1289   bool has_next() { return i < imax; }
1290   void next() { i++; }
1291   Node* get() { return node->fast_out(i); }
1292 };
1293 
1294 
1295 //-----------------------------------------------------------------------------
1296 // Map dense integer indices to Nodes.  Uses classic doubling-array trick.
1297 // Abstractly provides an infinite array of Node*'s, initialized to NULL.
1298 // Note that the constructor just zeros things, and since I use Arena
1299 // allocation I do not need a destructor to reclaim storage.
1300 class Node_Array : public ResourceObj {
1301 protected:
1302   Arena *_a;                    // Arena to allocate in
1303   uint   _max;
1304   Node **_nodes;
1305   void   grow( uint i );        // Grow array node to fit
1306 public:
1307   Node_Array(Arena *a) : _a(a), _max(OptoNodeListSize) {
1308     _nodes = NEW_ARENA_ARRAY( a, Node *, OptoNodeListSize );
1309     for( int i = 0; i < OptoNodeListSize; i++ ) {
1310       _nodes[i] = NULL;
1311     }
1312   }
1313 
1314   Node_Array(Node_Array *na) : _a(na->_a), _max(na->_max), _nodes(na->_nodes) {}
1315   Node *operator[] ( uint i ) const // Lookup, or NULL for not mapped
1316   { return (i<_max) ? _nodes[i] : (Node*)NULL; }
1317   Node *at( uint i ) const { assert(i<_max,"oob"); return _nodes[i]; }
1318   Node **adr() { return _nodes; }
1319   // Extend the mapping: index i maps to Node *n.
1320   void map( uint i, Node *n ) { if( i>=_max ) grow(i); _nodes[i] = n; }
1321   void insert( uint i, Node *n );
1322   void remove( uint i );        // Remove, preserving order
1323   void sort( C_sort_func_t func);
1324   void reset( Arena *new_a );   // Zap mapping to empty; reclaim storage
1325   void clear();                 // Set all entries to NULL, keep storage
1326   uint Size() const { return _max; }
1327   void dump() const;
1328 };
1329 
1330 class Node_List : public Node_Array {
1331   uint _cnt;
1332 public:
1333   Node_List() : Node_Array(Thread::current()->resource_area()), _cnt(0) {}
1334   Node_List(Arena *a) : Node_Array(a), _cnt(0) {}
1335   bool contains(Node* n) {
1336     for (uint e = 0; e < size(); e++) {
1337       if (at(e) == n) return true;
1338     }
1339     return false;
1340   }
1341   void insert( uint i, Node *n ) { Node_Array::insert(i,n); _cnt++; }
1342   void remove( uint i ) { Node_Array::remove(i); _cnt--; }
1343   void push( Node *b ) { map(_cnt++,b); }
1344   void yank( Node *n );         // Find and remove
1345   Node *pop() { return _nodes[--_cnt]; }
1346   Node *rpop() { Node *b = _nodes[0]; _nodes[0]=_nodes[--_cnt]; return b;}
1347   void clear() { _cnt = 0; Node_Array::clear(); } // retain storage
1348   uint size() const { return _cnt; }
1349   void dump() const;
1350 };
1351 
1352 //------------------------------Unique_Node_List-------------------------------
1353 class Unique_Node_List : public Node_List {
1354   VectorSet _in_worklist;
1355   uint _clock_index;            // Index in list where to pop from next
1356 public:
1357   Unique_Node_List() : Node_List(), _in_worklist(Thread::current()->resource_area()), _clock_index(0) {}
1358   Unique_Node_List(Arena *a) : Node_List(a), _in_worklist(a), _clock_index(0) {}
1359 
1360   void remove( Node *n );
1361   bool member( Node *n ) { return _in_worklist.test(n->_idx) != 0; }
1362   VectorSet &member_set(){ return _in_worklist; }
1363 
1364   void push( Node *b ) {
1365     if( !_in_worklist.test_set(b->_idx) )
1366       Node_List::push(b);
1367   }
1368   Node *pop() {
1369     if( _clock_index >= size() ) _clock_index = 0;
1370     Node *b = at(_clock_index);
1371     map( _clock_index, Node_List::pop());
1372     if (size() != 0) _clock_index++; // Always start from 0
1373     _in_worklist >>= b->_idx;
1374     return b;
1375   }
1376   Node *remove( uint i ) {
1377     Node *b = Node_List::at(i);
1378     _in_worklist >>= b->_idx;
1379     map(i,Node_List::pop());
1380     return b;
1381   }
1382   void yank( Node *n ) { _in_worklist >>= n->_idx; Node_List::yank(n); }
1383   void  clear() {
1384     _in_worklist.Clear();        // Discards storage but grows automatically
1385     Node_List::clear();
1386     _clock_index = 0;
1387   }
1388 
1389   // Used after parsing to remove useless nodes before Iterative GVN
1390   void remove_useless_nodes(VectorSet &useful);
1391 
1392 #ifndef PRODUCT
1393   void print_set() const { _in_worklist.print(); }
1394 #endif
1395 };
1396 
1397 // Inline definition of Compile::record_for_igvn must be deferred to this point.
1398 inline void Compile::record_for_igvn(Node* n) {
1399   _for_igvn->push(n);
1400 }
1401 
1402 //------------------------------Node_Stack-------------------------------------
1403 class Node_Stack {
1404 protected:
1405   struct INode {
1406     Node *node; // Processed node
1407     uint  indx; // Index of next node's child
1408   };
1409   INode *_inode_top; // tos, stack grows up
1410   INode *_inode_max; // End of _inodes == _inodes + _max
1411   INode *_inodes;    // Array storage for the stack
1412   Arena *_a;         // Arena to allocate in
1413   void grow();
1414 public:
1415   Node_Stack(int size) {
1416     size_t max = (size > OptoNodeListSize) ? size : OptoNodeListSize;
1417     _a = Thread::current()->resource_area();
1418     _inodes = NEW_ARENA_ARRAY( _a, INode, max );
1419     _inode_max = _inodes + max;
1420     _inode_top = _inodes - 1; // stack is empty
1421   }
1422 
1423   Node_Stack(Arena *a, int size) : _a(a) {
1424     size_t max = (size > OptoNodeListSize) ? size : OptoNodeListSize;
1425     _inodes = NEW_ARENA_ARRAY( _a, INode, max );
1426     _inode_max = _inodes + max;
1427     _inode_top = _inodes - 1; // stack is empty
1428   }
1429 
1430   void pop() {
1431     assert(_inode_top >= _inodes, "node stack underflow");
1432     --_inode_top;
1433   }
1434   void push(Node *n, uint i) {
1435     ++_inode_top;
1436     if (_inode_top >= _inode_max) grow();
1437     INode *top = _inode_top; // optimization
1438     top->node = n;
1439     top->indx = i;
1440   }
1441   Node *node() const {
1442     return _inode_top->node;
1443   }
1444   Node* node_at(uint i) const {
1445     assert(_inodes + i <= _inode_top, "in range");
1446     return _inodes[i].node;
1447   }
1448   uint index() const {
1449     return _inode_top->indx;
1450   }
1451   uint index_at(uint i) const {
1452     assert(_inodes + i <= _inode_top, "in range");
1453     return _inodes[i].indx;
1454   }
1455   void set_node(Node *n) {
1456     _inode_top->node = n;
1457   }
1458   void set_index(uint i) {
1459     _inode_top->indx = i;
1460   }
1461   uint size_max() const { return (uint)pointer_delta(_inode_max, _inodes,  sizeof(INode)); } // Max size
1462   uint size() const { return (uint)pointer_delta((_inode_top+1), _inodes,  sizeof(INode)); } // Current size
1463   bool is_nonempty() const { return (_inode_top >= _inodes); }
1464   bool is_empty() const { return (_inode_top < _inodes); }
1465   void clear() { _inode_top = _inodes - 1; } // retain storage
1466 
1467   // Node_Stack is used to map nodes.
1468   Node* find(uint idx) const;
1469 };
1470 
1471 
1472 //-----------------------------Node_Notes--------------------------------------
1473 // Debugging or profiling annotations loosely and sparsely associated
1474 // with some nodes.  See Compile::node_notes_at for the accessor.
1475 class Node_Notes VALUE_OBJ_CLASS_SPEC {
1476   JVMState* _jvms;
1477 
1478 public:
1479   Node_Notes(JVMState* jvms = NULL) {
1480     _jvms = jvms;
1481   }
1482 
1483   JVMState* jvms()            { return _jvms; }
1484   void  set_jvms(JVMState* x) {        _jvms = x; }
1485 
1486   // True if there is nothing here.
1487   bool is_clear() {
1488     return (_jvms == NULL);
1489   }
1490 
1491   // Make there be nothing here.
1492   void clear() {
1493     _jvms = NULL;
1494   }
1495 
1496   // Make a new, clean node notes.
1497   static Node_Notes* make(Compile* C) {
1498     Node_Notes* nn = NEW_ARENA_ARRAY(C->comp_arena(), Node_Notes, 1);
1499     nn->clear();
1500     return nn;
1501   }
1502 
1503   Node_Notes* clone(Compile* C) {
1504     Node_Notes* nn = NEW_ARENA_ARRAY(C->comp_arena(), Node_Notes, 1);
1505     (*nn) = (*this);
1506     return nn;
1507   }
1508 
1509   // Absorb any information from source.
1510   bool update_from(Node_Notes* source) {
1511     bool changed = false;
1512     if (source != NULL) {
1513       if (source->jvms() != NULL) {
1514         set_jvms(source->jvms());
1515         changed = true;
1516       }
1517     }
1518     return changed;
1519   }
1520 };
1521 
1522 // Inlined accessors for Compile::node_nodes that require the preceding class:
1523 inline Node_Notes*
1524 Compile::locate_node_notes(GrowableArray<Node_Notes*>* arr,
1525                            int idx, bool can_grow) {
1526   assert(idx >= 0, "oob");
1527   int block_idx = (idx >> _log2_node_notes_block_size);
1528   int grow_by = (block_idx - (arr == NULL? 0: arr->length()));
1529   if (grow_by >= 0) {
1530     if (!can_grow)  return NULL;
1531     grow_node_notes(arr, grow_by + 1);
1532   }
1533   // (Every element of arr is a sub-array of length _node_notes_block_size.)
1534   return arr->at(block_idx) + (idx & (_node_notes_block_size-1));
1535 }
1536 
1537 inline bool
1538 Compile::set_node_notes_at(int idx, Node_Notes* value) {
1539   if (value == NULL || value->is_clear())
1540     return false;  // nothing to write => write nothing
1541   Node_Notes* loc = locate_node_notes(_node_note_array, idx, true);
1542   assert(loc != NULL, "");
1543   return loc->update_from(value);
1544 }
1545 
1546 
1547 //------------------------------TypeNode---------------------------------------
1548 // Node with a Type constant.
1549 class TypeNode : public Node {
1550 protected:
1551   virtual uint hash() const;    // Check the type
1552   virtual uint cmp( const Node &n ) const;
1553   virtual uint size_of() const; // Size is bigger
1554   const Type* const _type;
1555 public:
1556   void set_type(const Type* t) {
1557     assert(t != NULL, "sanity");
1558     debug_only(uint check_hash = (VerifyHashTableKeys && _hash_lock) ? hash() : NO_HASH);
1559     *(const Type**)&_type = t;   // cast away const-ness
1560     // If this node is in the hash table, make sure it doesn't need a rehash.
1561     assert(check_hash == NO_HASH || check_hash == hash(), "type change must preserve hash code");
1562   }
1563   const Type* type() const { assert(_type != NULL, "sanity"); return _type; };
1564   TypeNode( const Type *t, uint required ) : Node(required), _type(t) {
1565     init_class_id(Class_Type);
1566   }
1567   virtual const Type *Value( PhaseTransform *phase ) const;
1568   virtual const Type *bottom_type() const;
1569   virtual       uint  ideal_reg() const;
1570 #ifndef PRODUCT
1571   virtual void dump_spec(outputStream *st) const;
1572 #endif
1573 };
1574 
1575 #endif // SHARE_VM_OPTO_NODE_HPP