1 /*
   2  * Copyright (c) 1997, 2016, 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/vectset.hpp"
  29 #include "opto/compile.hpp"
  30 #include "opto/type.hpp"
  31 
  32 // Portions of code courtesy of Clifford Click
  33 
  34 // Optimization - Graph Style
  35 
  36 
  37 class AbstractLockNode;
  38 class AddNode;
  39 class AddPNode;
  40 class AliasInfo;
  41 class AllocateArrayNode;
  42 class AllocateNode;
  43 class ArrayCopyNode;
  44 class Block;
  45 class BoolNode;
  46 class BoxLockNode;
  47 class CMoveNode;
  48 class CallDynamicJavaNode;
  49 class CallJavaNode;
  50 class CallLeafNode;
  51 class CallNode;
  52 class CallRuntimeNode;
  53 class CallStaticJavaNode;
  54 class CastIINode;
  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 CompareAndSwapNode;
  64 class CompareAndExchangeNode;
  65 class CountedLoopNode;
  66 class CountedLoopEndNode;
  67 class DecodeNarrowPtrNode;
  68 class DecodeNNode;
  69 class DecodeNKlassNode;
  70 class EncodeNarrowPtrNode;
  71 class EncodePNode;
  72 class EncodePKlassNode;
  73 class FastLockNode;
  74 class FastUnlockNode;
  75 class IfNode;
  76 class IfFalseNode;
  77 class IfTrueNode;
  78 class InitializeNode;
  79 class JVMState;
  80 class JumpNode;
  81 class JumpProjNode;
  82 class LoadNode;
  83 class LoadStoreNode;
  84 class LockNode;
  85 class LoopNode;
  86 class MachBranchNode;
  87 class MachCallDynamicJavaNode;
  88 class MachCallJavaNode;
  89 class MachCallLeafNode;
  90 class MachCallNode;
  91 class MachCallRuntimeNode;
  92 class MachCallStaticJavaNode;
  93 class MachConstantBaseNode;
  94 class MachConstantNode;
  95 class MachGotoNode;
  96 class MachIfNode;
  97 class MachNode;
  98 class MachNullCheckNode;
  99 class MachProjNode;
 100 class MachReturnNode;
 101 class MachSafePointNode;
 102 class MachSpillCopyNode;
 103 class MachTempNode;
 104 class MachMergeNode;
 105 class Matcher;
 106 class MemBarNode;
 107 class MemBarStoreStoreNode;
 108 class MemNode;
 109 class MergeMemNode;
 110 class MulNode;
 111 class MultiNode;
 112 class MultiBranchNode;
 113 class NeverBranchNode;
 114 class OuterStripMinedLoopNode;
 115 class OuterStripMinedLoopEndNode;
 116 class Node;
 117 class Node_Array;
 118 class Node_List;
 119 class Node_Stack;
 120 class NullCheckNode;
 121 class OopMap;
 122 class ParmNode;
 123 class PCTableNode;
 124 class PhaseCCP;
 125 class PhaseGVN;
 126 class PhaseIterGVN;
 127 class PhaseRegAlloc;
 128 class PhaseTransform;
 129 class PhaseValues;
 130 class PhiNode;
 131 class Pipeline;
 132 class ProjNode;
 133 class RangeCheckNode;
 134 class RegMask;
 135 class RegionNode;
 136 class RootNode;
 137 class SafePointNode;
 138 class SafePointScalarObjectNode;
 139 class StartNode;
 140 class State;
 141 class StoreNode;
 142 class SubNode;
 143 class Type;
 144 class TypeNode;
 145 class UnlockNode;
 146 class VectorNode;
 147 class LoadVectorNode;
 148 class StoreVectorNode;
 149 class VectorSet;
 150 typedef void (*NFunc)(Node&,void*);
 151 extern "C" {
 152   typedef int (*C_sort_func_t)(const void *, const void *);
 153 }
 154 
 155 // The type of all node counts and indexes.
 156 // It must hold at least 16 bits, but must also be fast to load and store.
 157 // This type, if less than 32 bits, could limit the number of possible nodes.
 158 // (To make this type platform-specific, move to globalDefinitions_xxx.hpp.)
 159 typedef unsigned int node_idx_t;
 160 
 161 
 162 #ifndef OPTO_DU_ITERATOR_ASSERT
 163 #ifdef ASSERT
 164 #define OPTO_DU_ITERATOR_ASSERT 1
 165 #else
 166 #define OPTO_DU_ITERATOR_ASSERT 0
 167 #endif
 168 #endif //OPTO_DU_ITERATOR_ASSERT
 169 
 170 #if OPTO_DU_ITERATOR_ASSERT
 171 class DUIterator;
 172 class DUIterator_Fast;
 173 class DUIterator_Last;
 174 #else
 175 typedef uint   DUIterator;
 176 typedef Node** DUIterator_Fast;
 177 typedef Node** DUIterator_Last;
 178 #endif
 179 
 180 // Node Sentinel
 181 #define NodeSentinel (Node*)-1
 182 
 183 // Unknown count frequency
 184 #define COUNT_UNKNOWN (-1.0f)
 185 
 186 //------------------------------Node-------------------------------------------
 187 // Nodes define actions in the program.  They create values, which have types.
 188 // They are both vertices in a directed graph and program primitives.  Nodes
 189 // are labeled; the label is the "opcode", the primitive function in the lambda
 190 // calculus sense that gives meaning to the Node.  Node inputs are ordered (so
 191 // that "a-b" is different from "b-a").  The inputs to a Node are the inputs to
 192 // the Node's function.  These inputs also define a Type equation for the Node.
 193 // Solving these Type equations amounts to doing dataflow analysis.
 194 // Control and data are uniformly represented in the graph.  Finally, Nodes
 195 // have a unique dense integer index which is used to index into side arrays
 196 // whenever I have phase-specific information.
 197 
 198 class Node {
 199   friend class VMStructs;
 200 
 201   // Lots of restrictions on cloning Nodes
 202   Node(const Node&);            // not defined; linker error to use these
 203   Node &operator=(const Node &rhs);
 204 
 205 public:
 206   friend class Compile;
 207   #if OPTO_DU_ITERATOR_ASSERT
 208   friend class DUIterator_Common;
 209   friend class DUIterator;
 210   friend class DUIterator_Fast;
 211   friend class DUIterator_Last;
 212   #endif
 213 
 214   // Because Nodes come and go, I define an Arena of Node structures to pull
 215   // from.  This should allow fast access to node creation & deletion.  This
 216   // field is a local cache of a value defined in some "program fragment" for
 217   // which these Nodes are just a part of.
 218 
 219   inline void* operator new(size_t x) throw() {
 220     Compile* C = Compile::current();
 221     Node* n = (Node*)C->node_arena()->Amalloc_D(x);
 222     return (void*)n;
 223   }
 224 
 225   // Delete is a NOP
 226   void operator delete( void *ptr ) {}
 227   // Fancy destructor; eagerly attempt to reclaim Node numberings and storage
 228   void destruct();
 229 
 230   // Create a new Node.  Required is the number is of inputs required for
 231   // semantic correctness.
 232   Node( uint required );
 233 
 234   // Create a new Node with given input edges.
 235   // This version requires use of the "edge-count" new.
 236   // E.g.  new (C,3) FooNode( C, NULL, left, right );
 237   Node( Node *n0 );
 238   Node( Node *n0, Node *n1 );
 239   Node( Node *n0, Node *n1, Node *n2 );
 240   Node( Node *n0, Node *n1, Node *n2, Node *n3 );
 241   Node( Node *n0, Node *n1, Node *n2, Node *n3, Node *n4 );
 242   Node( Node *n0, Node *n1, Node *n2, Node *n3, Node *n4, Node *n5 );
 243   Node( Node *n0, Node *n1, Node *n2, Node *n3,
 244             Node *n4, Node *n5, Node *n6 );
 245 
 246   // Clone an inherited Node given only the base Node type.
 247   Node* clone() const;
 248 
 249   // Clone a Node, immediately supplying one or two new edges.
 250   // The first and second arguments, if non-null, replace in(1) and in(2),
 251   // respectively.
 252   Node* clone_with_data_edge(Node* in1, Node* in2 = NULL) const {
 253     Node* nn = clone();
 254     if (in1 != NULL)  nn->set_req(1, in1);
 255     if (in2 != NULL)  nn->set_req(2, in2);
 256     return nn;
 257   }
 258 
 259 private:
 260   // Shared setup for the above constructors.
 261   // Handles all interactions with Compile::current.
 262   // Puts initial values in all Node fields except _idx.
 263   // Returns the initial value for _idx, which cannot
 264   // be initialized by assignment.
 265   inline int Init(int req);
 266 
 267 //----------------- input edge handling
 268 protected:
 269   friend class PhaseCFG;        // Access to address of _in array elements
 270   Node **_in;                   // Array of use-def references to Nodes
 271   Node **_out;                  // Array of def-use references to Nodes
 272 
 273   // Input edges are split into two categories.  Required edges are required
 274   // for semantic correctness; order is important and NULLs are allowed.
 275   // Precedence edges are used to help determine execution order and are
 276   // added, e.g., for scheduling purposes.  They are unordered and not
 277   // duplicated; they have no embedded NULLs.  Edges from 0 to _cnt-1
 278   // are required, from _cnt to _max-1 are precedence edges.
 279   node_idx_t _cnt;              // Total number of required Node inputs.
 280 
 281   node_idx_t _max;              // Actual length of input array.
 282 
 283   // Output edges are an unordered list of def-use edges which exactly
 284   // correspond to required input edges which point from other nodes
 285   // to this one.  Thus the count of the output edges is the number of
 286   // users of this node.
 287   node_idx_t _outcnt;           // Total number of Node outputs.
 288 
 289   node_idx_t _outmax;           // Actual length of output array.
 290 
 291   // Grow the actual input array to the next larger power-of-2 bigger than len.
 292   void grow( uint len );
 293   // Grow the output array to the next larger power-of-2 bigger than len.
 294   void out_grow( uint len );
 295 
 296  public:
 297   // Each Node is assigned a unique small/dense number.  This number is used
 298   // to index into auxiliary arrays of data and bit vectors.
 299   // The field _idx is declared constant to defend against inadvertent assignments,
 300   // since it is used by clients as a naked field. However, the field's value can be
 301   // changed using the set_idx() method.
 302   //
 303   // The PhaseRenumberLive phase renumbers nodes based on liveness information.
 304   // Therefore, it updates the value of the _idx field. The parse-time _idx is
 305   // preserved in _parse_idx.
 306   const node_idx_t _idx;
 307   DEBUG_ONLY(const node_idx_t _parse_idx;)
 308 
 309   // Get the (read-only) number of input edges
 310   uint req() const { return _cnt; }
 311   uint len() const { return _max; }
 312   // Get the (read-only) number of output edges
 313   uint outcnt() const { return _outcnt; }
 314 
 315 #if OPTO_DU_ITERATOR_ASSERT
 316   // Iterate over the out-edges of this node.  Deletions are illegal.
 317   inline DUIterator outs() const;
 318   // Use this when the out array might have changed to suppress asserts.
 319   inline DUIterator& refresh_out_pos(DUIterator& i) const;
 320   // Does the node have an out at this position?  (Used for iteration.)
 321   inline bool has_out(DUIterator& i) const;
 322   inline Node*    out(DUIterator& i) const;
 323   // Iterate over the out-edges of this node.  All changes are illegal.
 324   inline DUIterator_Fast fast_outs(DUIterator_Fast& max) const;
 325   inline Node*    fast_out(DUIterator_Fast& i) const;
 326   // Iterate over the out-edges of this node, deleting one at a time.
 327   inline DUIterator_Last last_outs(DUIterator_Last& min) const;
 328   inline Node*    last_out(DUIterator_Last& i) const;
 329   // The inline bodies of all these methods are after the iterator definitions.
 330 #else
 331   // Iterate over the out-edges of this node.  Deletions are illegal.
 332   // This iteration uses integral indexes, to decouple from array reallocations.
 333   DUIterator outs() const  { return 0; }
 334   // Use this when the out array might have changed to suppress asserts.
 335   DUIterator refresh_out_pos(DUIterator i) const { return i; }
 336 
 337   // Reference to the i'th output Node.  Error if out of bounds.
 338   Node*    out(DUIterator i) const { assert(i < _outcnt, "oob"); return _out[i]; }
 339   // Does the node have an out at this position?  (Used for iteration.)
 340   bool has_out(DUIterator i) const { return i < _outcnt; }
 341 
 342   // Iterate over the out-edges of this node.  All changes are illegal.
 343   // This iteration uses a pointer internal to the out array.
 344   DUIterator_Fast fast_outs(DUIterator_Fast& max) const {
 345     Node** out = _out;
 346     // Assign a limit pointer to the reference argument:
 347     max = out + (ptrdiff_t)_outcnt;
 348     // Return the base pointer:
 349     return out;
 350   }
 351   Node*    fast_out(DUIterator_Fast i) const  { return *i; }
 352   // Iterate over the out-edges of this node, deleting one at a time.
 353   // This iteration uses a pointer internal to the out array.
 354   DUIterator_Last last_outs(DUIterator_Last& min) const {
 355     Node** out = _out;
 356     // Assign a limit pointer to the reference argument:
 357     min = out;
 358     // Return the pointer to the start of the iteration:
 359     return out + (ptrdiff_t)_outcnt - 1;
 360   }
 361   Node*    last_out(DUIterator_Last i) const  { return *i; }
 362 #endif
 363 
 364   // Reference to the i'th input Node.  Error if out of bounds.
 365   Node* in(uint i) const { assert(i < _max, "oob: i=%d, _max=%d", i, _max); return _in[i]; }
 366   // Reference to the i'th input Node.  NULL if out of bounds.
 367   Node* lookup(uint i) const { return ((i < _max) ? _in[i] : NULL); }
 368   // Reference to the i'th output Node.  Error if out of bounds.
 369   // Use this accessor sparingly.  We are going trying to use iterators instead.
 370   Node* raw_out(uint i) const { assert(i < _outcnt,"oob"); return _out[i]; }
 371   // Return the unique out edge.
 372   Node* unique_out() const { assert(_outcnt==1,"not unique"); return _out[0]; }
 373   // Delete out edge at position 'i' by moving last out edge to position 'i'
 374   void  raw_del_out(uint i) {
 375     assert(i < _outcnt,"oob");
 376     assert(_outcnt > 0,"oob");
 377     #if OPTO_DU_ITERATOR_ASSERT
 378     // Record that a change happened here.
 379     debug_only(_last_del = _out[i]; ++_del_tick);
 380     #endif
 381     _out[i] = _out[--_outcnt];
 382     // Smash the old edge so it can't be used accidentally.
 383     debug_only(_out[_outcnt] = (Node *)(uintptr_t)0xdeadbeef);
 384   }
 385 
 386 #ifdef ASSERT
 387   bool is_dead() const;
 388 #define is_not_dead(n) ((n) == NULL || !VerifyIterativeGVN || !((n)->is_dead()))
 389 #endif
 390   // Check whether node has become unreachable
 391   bool is_unreachable(PhaseIterGVN &igvn) const;
 392 
 393   // Set a required input edge, also updates corresponding output edge
 394   void add_req( Node *n ); // Append a NEW required input
 395   void add_req( Node *n0, Node *n1 ) {
 396     add_req(n0); add_req(n1); }
 397   void add_req( Node *n0, Node *n1, Node *n2 ) {
 398     add_req(n0); add_req(n1); add_req(n2); }
 399   void add_req_batch( Node* n, uint m ); // Append m NEW required inputs (all n).
 400   void del_req( uint idx ); // Delete required edge & compact
 401   void del_req_ordered( uint idx ); // Delete required edge & compact with preserved order
 402   void ins_req( uint i, Node *n ); // Insert a NEW required input
 403   void set_req( uint i, Node *n ) {
 404     assert( is_not_dead(n), "can not use dead node");
 405     assert( i < _cnt, "oob: i=%d, _cnt=%d", i, _cnt);
 406     assert( !VerifyHashTableKeys || _hash_lock == 0,
 407             "remove node from hash table before modifying it");
 408     Node** p = &_in[i];    // cache this._in, across the del_out call
 409     if (*p != NULL)  (*p)->del_out((Node *)this);
 410     (*p) = n;
 411     if (n != NULL)      n->add_out((Node *)this);
 412     Compile::current()->record_modified_node(this);
 413   }
 414   // Light version of set_req() to init inputs after node creation.
 415   void init_req( uint i, Node *n ) {
 416     assert( i == 0 && this == n ||
 417             is_not_dead(n), "can not use dead node");
 418     assert( i < _cnt, "oob");
 419     assert( !VerifyHashTableKeys || _hash_lock == 0,
 420             "remove node from hash table before modifying it");
 421     assert( _in[i] == NULL, "sanity");
 422     _in[i] = n;
 423     if (n != NULL)      n->add_out((Node *)this);
 424     Compile::current()->record_modified_node(this);
 425   }
 426   // Find first occurrence of n among my edges:
 427   int find_edge(Node* n);
 428   int find_prec_edge(Node* n) {
 429     for (uint i = req(); i < len(); i++) {
 430       if (_in[i] == n) return i;
 431       if (_in[i] == NULL) {
 432         DEBUG_ONLY( while ((++i) < len()) assert(_in[i] == NULL, "Gap in prec edges!"); )
 433         break;
 434       }
 435     }
 436     return -1;
 437   }
 438   int replace_edge(Node* old, Node* neww);
 439   int replace_edges_in_range(Node* old, Node* neww, int start, int end);
 440   // NULL out all inputs to eliminate incoming Def-Use edges.
 441   // Return the number of edges between 'n' and 'this'
 442   int  disconnect_inputs(Node *n, Compile *c);
 443 
 444   // Quickly, return true if and only if I am Compile::current()->top().
 445   bool is_top() const {
 446     assert((this == (Node*) Compile::current()->top()) == (_out == NULL), "");
 447     return (_out == NULL);
 448   }
 449   // Reaffirm invariants for is_top.  (Only from Compile::set_cached_top_node.)
 450   void setup_is_top();
 451 
 452   // Strip away casting.  (It is depth-limited.)
 453   Node* uncast() const;
 454   // Return whether two Nodes are equivalent, after stripping casting.
 455   bool eqv_uncast(const Node* n) const {
 456     return (this->uncast() == n->uncast());
 457   }
 458 
 459   // Find out of current node that matches opcode.
 460   Node* find_out_with(int opcode);
 461   // Return true if the current node has an out that matches opcode.
 462   bool has_out_with(int opcode);
 463   // Return true if the current node has an out that matches any of the opcodes.
 464   bool has_out_with(int opcode1, int opcode2, int opcode3, int opcode4);
 465 
 466 private:
 467   static Node* uncast_helper(const Node* n);
 468 
 469   // Add an output edge to the end of the list
 470   void add_out( Node *n ) {
 471     if (is_top())  return;
 472     if( _outcnt == _outmax ) out_grow(_outcnt);
 473     _out[_outcnt++] = n;
 474   }
 475   // Delete an output edge
 476   void del_out( Node *n ) {
 477     if (is_top())  return;
 478     Node** outp = &_out[_outcnt];
 479     // Find and remove n
 480     do {
 481       assert(outp > _out, "Missing Def-Use edge");
 482     } while (*--outp != n);
 483     *outp = _out[--_outcnt];
 484     // Smash the old edge so it can't be used accidentally.
 485     debug_only(_out[_outcnt] = (Node *)(uintptr_t)0xdeadbeef);
 486     // Record that a change happened here.
 487     #if OPTO_DU_ITERATOR_ASSERT
 488     debug_only(_last_del = n; ++_del_tick);
 489     #endif
 490   }
 491   // Close gap after removing edge.
 492   void close_prec_gap_at(uint gap) {
 493     assert(_cnt <= gap && gap < _max, "no valid prec edge");
 494     uint i = gap;
 495     Node *last = NULL;
 496     for (; i < _max-1; ++i) {
 497       Node *next = _in[i+1];
 498       if (next == NULL) break;
 499       last = next;
 500     }
 501     _in[gap] = last; // Move last slot to empty one.
 502     _in[i] = NULL;   // NULL out last slot.
 503   }
 504 
 505 public:
 506   // Globally replace this node by a given new node, updating all uses.
 507   void replace_by(Node* new_node);
 508   // Globally replace this node by a given new node, updating all uses
 509   // and cutting input edges of old node.
 510   void subsume_by(Node* new_node, Compile* c) {
 511     replace_by(new_node);
 512     disconnect_inputs(NULL, c);
 513   }
 514   void set_req_X( uint i, Node *n, PhaseIterGVN *igvn );
 515   // Find the one non-null required input.  RegionNode only
 516   Node *nonnull_req() const;
 517   // Add or remove precedence edges
 518   void add_prec( Node *n );
 519   void rm_prec( uint i );
 520 
 521   // Note: prec(i) will not necessarily point to n if edge already exists.
 522   void set_prec( uint i, Node *n ) {
 523     assert(i < _max, "oob: i=%d, _max=%d", i, _max);
 524     assert(is_not_dead(n), "can not use dead node");
 525     assert(i >= _cnt, "not a precedence edge");
 526     // Avoid spec violation: duplicated prec edge.
 527     if (_in[i] == n) return;
 528     if (n == NULL || find_prec_edge(n) != -1) {
 529       rm_prec(i);
 530       return;
 531     }
 532     if (_in[i] != NULL) _in[i]->del_out((Node *)this);
 533     _in[i] = n;
 534     if (n != NULL) n->add_out((Node *)this);
 535   }
 536 
 537   // Set this node's index, used by cisc_version to replace current node
 538   void set_idx(uint new_idx) {
 539     const node_idx_t* ref = &_idx;
 540     *(node_idx_t*)ref = new_idx;
 541   }
 542   // Swap input edge order.  (Edge indexes i1 and i2 are usually 1 and 2.)
 543   void swap_edges(uint i1, uint i2) {
 544     debug_only(uint check_hash = (VerifyHashTableKeys && _hash_lock) ? hash() : NO_HASH);
 545     // Def-Use info is unchanged
 546     Node* n1 = in(i1);
 547     Node* n2 = in(i2);
 548     _in[i1] = n2;
 549     _in[i2] = n1;
 550     // If this node is in the hash table, make sure it doesn't need a rehash.
 551     assert(check_hash == NO_HASH || check_hash == hash(), "edge swap must preserve hash code");
 552   }
 553 
 554   // Iterators over input Nodes for a Node X are written as:
 555   // for( i = 0; i < X.req(); i++ ) ... X[i] ...
 556   // NOTE: Required edges can contain embedded NULL pointers.
 557 
 558 //----------------- Other Node Properties
 559 
 560   // Generate class IDs for (some) ideal nodes so that it is possible to determine
 561   // the type of a node using a non-virtual method call (the method is_<Node>() below).
 562   //
 563   // A class ID of an ideal node is a set of bits. In a class ID, a single bit determines
 564   // the type of the node the ID represents; another subset of an ID's bits are reserved
 565   // for the superclasses of the node represented by the ID.
 566   //
 567   // By design, if A is a supertype of B, A.is_B() returns true and B.is_A()
 568   // returns false. A.is_A() returns true.
 569   //
 570   // If two classes, A and B, have the same superclass, a different bit of A's class id
 571   // is reserved for A's type than for B's type. That bit is specified by the third
 572   // parameter in the macro DEFINE_CLASS_ID.
 573   //
 574   // By convention, classes with deeper hierarchy are declared first. Moreover,
 575   // classes with the same hierarchy depth are sorted by usage frequency.
 576   //
 577   // The query method masks the bits to cut off bits of subclasses and then compares
 578   // the result with the class id (see the macro DEFINE_CLASS_QUERY below).
 579   //
 580   //  Class_MachCall=30, ClassMask_MachCall=31
 581   // 12               8               4               0
 582   //  0   0   0   0   0   0   0   0   1   1   1   1   0
 583   //                                  |   |   |   |
 584   //                                  |   |   |   Bit_Mach=2
 585   //                                  |   |   Bit_MachReturn=4
 586   //                                  |   Bit_MachSafePoint=8
 587   //                                  Bit_MachCall=16
 588   //
 589   //  Class_CountedLoop=56, ClassMask_CountedLoop=63
 590   // 12               8               4               0
 591   //  0   0   0   0   0   0   0   1   1   1   0   0   0
 592   //                              |   |   |
 593   //                              |   |   Bit_Region=8
 594   //                              |   Bit_Loop=16
 595   //                              Bit_CountedLoop=32
 596 
 597   #define DEFINE_CLASS_ID(cl, supcl, subn) \
 598   Bit_##cl = (Class_##supcl == 0) ? 1 << subn : (Bit_##supcl) << (1 + subn) , \
 599   Class_##cl = Class_##supcl + Bit_##cl , \
 600   ClassMask_##cl = ((Bit_##cl << 1) - 1) ,
 601 
 602   // This enum is used only for C2 ideal and mach nodes with is_<node>() methods
 603   // so that it's values fits into 16 bits.
 604   enum NodeClasses {
 605     Bit_Node   = 0x0000,
 606     Class_Node = 0x0000,
 607     ClassMask_Node = 0xFFFF,
 608 
 609     DEFINE_CLASS_ID(Multi, Node, 0)
 610       DEFINE_CLASS_ID(SafePoint, Multi, 0)
 611         DEFINE_CLASS_ID(Call,      SafePoint, 0)
 612           DEFINE_CLASS_ID(CallJava,         Call, 0)
 613             DEFINE_CLASS_ID(CallStaticJava,   CallJava, 0)
 614             DEFINE_CLASS_ID(CallDynamicJava,  CallJava, 1)
 615           DEFINE_CLASS_ID(CallRuntime,      Call, 1)
 616             DEFINE_CLASS_ID(CallLeaf,         CallRuntime, 0)
 617           DEFINE_CLASS_ID(Allocate,         Call, 2)
 618             DEFINE_CLASS_ID(AllocateArray,    Allocate, 0)
 619           DEFINE_CLASS_ID(AbstractLock,     Call, 3)
 620             DEFINE_CLASS_ID(Lock,             AbstractLock, 0)
 621             DEFINE_CLASS_ID(Unlock,           AbstractLock, 1)
 622           DEFINE_CLASS_ID(ArrayCopy,        Call, 4)
 623       DEFINE_CLASS_ID(MultiBranch, Multi, 1)
 624         DEFINE_CLASS_ID(PCTable,     MultiBranch, 0)
 625           DEFINE_CLASS_ID(Catch,       PCTable, 0)
 626           DEFINE_CLASS_ID(Jump,        PCTable, 1)
 627         DEFINE_CLASS_ID(If,          MultiBranch, 1)
 628           DEFINE_CLASS_ID(CountedLoopEnd,         If, 0)
 629           DEFINE_CLASS_ID(RangeCheck,             If, 1)
 630           DEFINE_CLASS_ID(OuterStripMinedLoopEnd, If, 2)
 631         DEFINE_CLASS_ID(NeverBranch, MultiBranch, 2)
 632       DEFINE_CLASS_ID(Start,       Multi, 2)
 633       DEFINE_CLASS_ID(MemBar,      Multi, 3)
 634         DEFINE_CLASS_ID(Initialize,       MemBar, 0)
 635         DEFINE_CLASS_ID(MemBarStoreStore, MemBar, 1)
 636 
 637     DEFINE_CLASS_ID(Mach,  Node, 1)
 638       DEFINE_CLASS_ID(MachReturn, Mach, 0)
 639         DEFINE_CLASS_ID(MachSafePoint, MachReturn, 0)
 640           DEFINE_CLASS_ID(MachCall, MachSafePoint, 0)
 641             DEFINE_CLASS_ID(MachCallJava,         MachCall, 0)
 642               DEFINE_CLASS_ID(MachCallStaticJava,   MachCallJava, 0)
 643               DEFINE_CLASS_ID(MachCallDynamicJava,  MachCallJava, 1)
 644             DEFINE_CLASS_ID(MachCallRuntime,      MachCall, 1)
 645               DEFINE_CLASS_ID(MachCallLeaf,         MachCallRuntime, 0)
 646       DEFINE_CLASS_ID(MachBranch, Mach, 1)
 647         DEFINE_CLASS_ID(MachIf,         MachBranch, 0)
 648         DEFINE_CLASS_ID(MachGoto,       MachBranch, 1)
 649         DEFINE_CLASS_ID(MachNullCheck,  MachBranch, 2)
 650       DEFINE_CLASS_ID(MachSpillCopy,    Mach, 2)
 651       DEFINE_CLASS_ID(MachTemp,         Mach, 3)
 652       DEFINE_CLASS_ID(MachConstantBase, Mach, 4)
 653       DEFINE_CLASS_ID(MachConstant,     Mach, 5)
 654       DEFINE_CLASS_ID(MachMerge,        Mach, 6)
 655 
 656     DEFINE_CLASS_ID(Type,  Node, 2)
 657       DEFINE_CLASS_ID(Phi,   Type, 0)
 658       DEFINE_CLASS_ID(ConstraintCast, Type, 1)
 659         DEFINE_CLASS_ID(CastII, ConstraintCast, 0)
 660         DEFINE_CLASS_ID(CheckCastPP, ConstraintCast, 1)
 661       DEFINE_CLASS_ID(CMove, Type, 3)
 662       DEFINE_CLASS_ID(SafePointScalarObject, Type, 4)
 663       DEFINE_CLASS_ID(DecodeNarrowPtr, Type, 5)
 664         DEFINE_CLASS_ID(DecodeN, DecodeNarrowPtr, 0)
 665         DEFINE_CLASS_ID(DecodeNKlass, DecodeNarrowPtr, 1)
 666       DEFINE_CLASS_ID(EncodeNarrowPtr, Type, 6)
 667         DEFINE_CLASS_ID(EncodeP, EncodeNarrowPtr, 0)
 668         DEFINE_CLASS_ID(EncodePKlass, EncodeNarrowPtr, 1)
 669 
 670     DEFINE_CLASS_ID(Proj,  Node, 3)
 671       DEFINE_CLASS_ID(CatchProj, Proj, 0)
 672       DEFINE_CLASS_ID(JumpProj,  Proj, 1)
 673       DEFINE_CLASS_ID(IfTrue,    Proj, 2)
 674       DEFINE_CLASS_ID(IfFalse,   Proj, 3)
 675       DEFINE_CLASS_ID(Parm,      Proj, 4)
 676       DEFINE_CLASS_ID(MachProj,  Proj, 5)
 677 
 678     DEFINE_CLASS_ID(Mem,   Node, 4)
 679       DEFINE_CLASS_ID(Load,  Mem, 0)
 680         DEFINE_CLASS_ID(LoadVector,  Load, 0)
 681       DEFINE_CLASS_ID(Store, Mem, 1)
 682         DEFINE_CLASS_ID(StoreVector, Store, 0)
 683       DEFINE_CLASS_ID(LoadStore, Mem, 2)
 684         DEFINE_CLASS_ID(LoadStoreConditional, LoadStore, 0)
 685           DEFINE_CLASS_ID(CompareAndSwap, LoadStoreConditional, 0)
 686         DEFINE_CLASS_ID(CompareAndExchangeNode, LoadStore, 1)
 687 
 688     DEFINE_CLASS_ID(Region, Node, 5)
 689       DEFINE_CLASS_ID(Loop, Region, 0)
 690         DEFINE_CLASS_ID(Root,                Loop, 0)
 691         DEFINE_CLASS_ID(CountedLoop,         Loop, 1)
 692         DEFINE_CLASS_ID(OuterStripMinedLoop, Loop, 2)
 693 
 694     DEFINE_CLASS_ID(Sub,   Node, 6)
 695       DEFINE_CLASS_ID(Cmp,   Sub, 0)
 696         DEFINE_CLASS_ID(FastLock,   Cmp, 0)
 697         DEFINE_CLASS_ID(FastUnlock, Cmp, 1)
 698 
 699     DEFINE_CLASS_ID(MergeMem, Node, 7)
 700     DEFINE_CLASS_ID(Bool,     Node, 8)
 701     DEFINE_CLASS_ID(AddP,     Node, 9)
 702     DEFINE_CLASS_ID(BoxLock,  Node, 10)
 703     DEFINE_CLASS_ID(Add,      Node, 11)
 704     DEFINE_CLASS_ID(Mul,      Node, 12)
 705     DEFINE_CLASS_ID(Vector,   Node, 13)
 706     DEFINE_CLASS_ID(ClearArray, Node, 14)
 707 
 708     _max_classes  = ClassMask_ClearArray
 709   };
 710   #undef DEFINE_CLASS_ID
 711 
 712   // Flags are sorted by usage frequency.
 713   enum NodeFlags {
 714     Flag_is_Copy                     = 0x01, // should be first bit to avoid shift
 715     Flag_rematerialize               = Flag_is_Copy << 1,
 716     Flag_needs_anti_dependence_check = Flag_rematerialize << 1,
 717     Flag_is_macro                    = Flag_needs_anti_dependence_check << 1,
 718     Flag_is_Con                      = Flag_is_macro << 1,
 719     Flag_is_cisc_alternate           = Flag_is_Con << 1,
 720     Flag_is_dead_loop_safe           = Flag_is_cisc_alternate << 1,
 721     Flag_may_be_short_branch         = Flag_is_dead_loop_safe << 1,
 722     Flag_avoid_back_to_back_before   = Flag_may_be_short_branch << 1,
 723     Flag_avoid_back_to_back_after    = Flag_avoid_back_to_back_before << 1,
 724     Flag_has_call                    = Flag_avoid_back_to_back_after << 1,
 725     Flag_is_reduction                = Flag_has_call << 1,
 726     Flag_is_scheduled                = Flag_is_reduction << 1,
 727     Flag_has_vector_mask_set         = Flag_is_scheduled << 1,
 728     Flag_is_expensive                = Flag_has_vector_mask_set << 1,
 729     _max_flags = (Flag_is_expensive << 1) - 1 // allow flags combination
 730   };
 731 
 732 private:
 733   jushort _class_id;
 734   jushort _flags;
 735 
 736 protected:
 737   // These methods should be called from constructors only.
 738   void init_class_id(jushort c) {
 739     assert(c <= _max_classes, "invalid node class");
 740     _class_id = c; // cast out const
 741   }
 742   void init_flags(jushort fl) {
 743     assert(fl <= _max_flags, "invalid node flag");
 744     _flags |= fl;
 745   }
 746   void clear_flag(jushort fl) {
 747     assert(fl <= _max_flags, "invalid node flag");
 748     _flags &= ~fl;
 749   }
 750 
 751 public:
 752   const jushort class_id() const { return _class_id; }
 753 
 754   const jushort flags() const { return _flags; }
 755 
 756   void add_flag(jushort fl) { init_flags(fl); }
 757 
 758   void remove_flag(jushort fl) { clear_flag(fl); }
 759 
 760   // Return a dense integer opcode number
 761   virtual int Opcode() const;
 762 
 763   // Virtual inherited Node size
 764   virtual uint size_of() const;
 765 
 766   // Other interesting Node properties
 767   #define DEFINE_CLASS_QUERY(type)                           \
 768   bool is_##type() const {                                   \
 769     return ((_class_id & ClassMask_##type) == Class_##type); \
 770   }                                                          \
 771   type##Node *as_##type() const {                            \
 772     assert(is_##type(), "invalid node class");               \
 773     return (type##Node*)this;                                \
 774   }                                                          \
 775   type##Node* isa_##type() const {                           \
 776     return (is_##type()) ? as_##type() : NULL;               \
 777   }
 778 
 779   DEFINE_CLASS_QUERY(AbstractLock)
 780   DEFINE_CLASS_QUERY(Add)
 781   DEFINE_CLASS_QUERY(AddP)
 782   DEFINE_CLASS_QUERY(Allocate)
 783   DEFINE_CLASS_QUERY(AllocateArray)
 784   DEFINE_CLASS_QUERY(ArrayCopy)
 785   DEFINE_CLASS_QUERY(Bool)
 786   DEFINE_CLASS_QUERY(BoxLock)
 787   DEFINE_CLASS_QUERY(Call)
 788   DEFINE_CLASS_QUERY(CallDynamicJava)
 789   DEFINE_CLASS_QUERY(CallJava)
 790   DEFINE_CLASS_QUERY(CallLeaf)
 791   DEFINE_CLASS_QUERY(CallRuntime)
 792   DEFINE_CLASS_QUERY(CallStaticJava)
 793   DEFINE_CLASS_QUERY(Catch)
 794   DEFINE_CLASS_QUERY(CatchProj)
 795   DEFINE_CLASS_QUERY(CheckCastPP)
 796   DEFINE_CLASS_QUERY(CastII)
 797   DEFINE_CLASS_QUERY(ConstraintCast)
 798   DEFINE_CLASS_QUERY(ClearArray)
 799   DEFINE_CLASS_QUERY(CMove)
 800   DEFINE_CLASS_QUERY(Cmp)
 801   DEFINE_CLASS_QUERY(CountedLoop)
 802   DEFINE_CLASS_QUERY(CountedLoopEnd)
 803   DEFINE_CLASS_QUERY(DecodeNarrowPtr)
 804   DEFINE_CLASS_QUERY(DecodeN)
 805   DEFINE_CLASS_QUERY(DecodeNKlass)
 806   DEFINE_CLASS_QUERY(EncodeNarrowPtr)
 807   DEFINE_CLASS_QUERY(EncodeP)
 808   DEFINE_CLASS_QUERY(EncodePKlass)
 809   DEFINE_CLASS_QUERY(FastLock)
 810   DEFINE_CLASS_QUERY(FastUnlock)
 811   DEFINE_CLASS_QUERY(If)
 812   DEFINE_CLASS_QUERY(RangeCheck)
 813   DEFINE_CLASS_QUERY(IfFalse)
 814   DEFINE_CLASS_QUERY(IfTrue)
 815   DEFINE_CLASS_QUERY(Initialize)
 816   DEFINE_CLASS_QUERY(Jump)
 817   DEFINE_CLASS_QUERY(JumpProj)
 818   DEFINE_CLASS_QUERY(Load)
 819   DEFINE_CLASS_QUERY(LoadStore)
 820   DEFINE_CLASS_QUERY(Lock)
 821   DEFINE_CLASS_QUERY(Loop)
 822   DEFINE_CLASS_QUERY(Mach)
 823   DEFINE_CLASS_QUERY(MachBranch)
 824   DEFINE_CLASS_QUERY(MachCall)
 825   DEFINE_CLASS_QUERY(MachCallDynamicJava)
 826   DEFINE_CLASS_QUERY(MachCallJava)
 827   DEFINE_CLASS_QUERY(MachCallLeaf)
 828   DEFINE_CLASS_QUERY(MachCallRuntime)
 829   DEFINE_CLASS_QUERY(MachCallStaticJava)
 830   DEFINE_CLASS_QUERY(MachConstantBase)
 831   DEFINE_CLASS_QUERY(MachConstant)
 832   DEFINE_CLASS_QUERY(MachGoto)
 833   DEFINE_CLASS_QUERY(MachIf)
 834   DEFINE_CLASS_QUERY(MachNullCheck)
 835   DEFINE_CLASS_QUERY(MachProj)
 836   DEFINE_CLASS_QUERY(MachReturn)
 837   DEFINE_CLASS_QUERY(MachSafePoint)
 838   DEFINE_CLASS_QUERY(MachSpillCopy)
 839   DEFINE_CLASS_QUERY(MachTemp)
 840   DEFINE_CLASS_QUERY(MachMerge)
 841   DEFINE_CLASS_QUERY(Mem)
 842   DEFINE_CLASS_QUERY(MemBar)
 843   DEFINE_CLASS_QUERY(MemBarStoreStore)
 844   DEFINE_CLASS_QUERY(MergeMem)
 845   DEFINE_CLASS_QUERY(Mul)
 846   DEFINE_CLASS_QUERY(Multi)
 847   DEFINE_CLASS_QUERY(MultiBranch)
 848   DEFINE_CLASS_QUERY(OuterStripMinedLoop)
 849   DEFINE_CLASS_QUERY(OuterStripMinedLoopEnd)
 850   DEFINE_CLASS_QUERY(Parm)
 851   DEFINE_CLASS_QUERY(PCTable)
 852   DEFINE_CLASS_QUERY(Phi)
 853   DEFINE_CLASS_QUERY(Proj)
 854   DEFINE_CLASS_QUERY(Region)
 855   DEFINE_CLASS_QUERY(Root)
 856   DEFINE_CLASS_QUERY(SafePoint)
 857   DEFINE_CLASS_QUERY(SafePointScalarObject)
 858   DEFINE_CLASS_QUERY(Start)
 859   DEFINE_CLASS_QUERY(Store)
 860   DEFINE_CLASS_QUERY(Sub)
 861   DEFINE_CLASS_QUERY(Type)
 862   DEFINE_CLASS_QUERY(Vector)
 863   DEFINE_CLASS_QUERY(LoadVector)
 864   DEFINE_CLASS_QUERY(StoreVector)
 865   DEFINE_CLASS_QUERY(Unlock)
 866 
 867   #undef DEFINE_CLASS_QUERY
 868 
 869   // duplicate of is_MachSpillCopy()
 870   bool is_SpillCopy () const {
 871     return ((_class_id & ClassMask_MachSpillCopy) == Class_MachSpillCopy);
 872   }
 873 
 874   bool is_Con () const { return (_flags & Flag_is_Con) != 0; }
 875   // The data node which is safe to leave in dead loop during IGVN optimization.
 876   bool is_dead_loop_safe() const {
 877     return is_Phi() || (is_Proj() && in(0) == NULL) ||
 878            ((_flags & (Flag_is_dead_loop_safe | Flag_is_Con)) != 0 &&
 879             (!is_Proj() || !in(0)->is_Allocate()));
 880   }
 881 
 882   // is_Copy() returns copied edge index (0 or 1)
 883   uint is_Copy() const { return (_flags & Flag_is_Copy); }
 884 
 885   virtual bool is_CFG() const { return false; }
 886 
 887   // If this node is control-dependent on a test, can it be
 888   // rerouted to a dominating equivalent test?  This is usually
 889   // true of non-CFG nodes, but can be false for operations which
 890   // depend for their correct sequencing on more than one test.
 891   // (In that case, hoisting to a dominating test may silently
 892   // skip some other important test.)
 893   virtual bool depends_only_on_test() const { assert(!is_CFG(), ""); return true; };
 894 
 895   // When building basic blocks, I need to have a notion of block beginning
 896   // Nodes, next block selector Nodes (block enders), and next block
 897   // projections.  These calls need to work on their machine equivalents.  The
 898   // Ideal beginning Nodes are RootNode, RegionNode and StartNode.
 899   bool is_block_start() const {
 900     if ( is_Region() )
 901       return this == (const Node*)in(0);
 902     else
 903       return is_Start();
 904   }
 905 
 906   // The Ideal control projection Nodes are IfTrue/IfFalse, JumpProjNode, Root,
 907   // Goto and Return.  This call also returns the block ending Node.
 908   virtual const Node *is_block_proj() const;
 909 
 910   // The node is a "macro" node which needs to be expanded before matching
 911   bool is_macro() const { return (_flags & Flag_is_macro) != 0; }
 912   // The node is expensive: the best control is set during loop opts
 913   bool is_expensive() const { return (_flags & Flag_is_expensive) != 0 && in(0) != NULL; }
 914 
 915   // An arithmetic node which accumulates a data in a loop.
 916   // It must have the loop's phi as input and provide a def to the phi.
 917   bool is_reduction() const { return (_flags & Flag_is_reduction) != 0; }
 918 
 919   // The node is a CountedLoopEnd with a mask annotation so as to emit a restore context
 920   bool has_vector_mask_set() const { return (_flags & Flag_has_vector_mask_set) != 0; }
 921 
 922   // Used in lcm to mark nodes that have scheduled
 923   bool is_scheduled() const { return (_flags & Flag_is_scheduled) != 0; }
 924 
 925 //----------------- Optimization
 926 
 927   // Get the worst-case Type output for this Node.
 928   virtual const class Type *bottom_type() const;
 929 
 930   // If we find a better type for a node, try to record it permanently.
 931   // Return true if this node actually changed.
 932   // Be sure to do the hash_delete game in the "rehash" variant.
 933   void raise_bottom_type(const Type* new_type);
 934 
 935   // Get the address type with which this node uses and/or defs memory,
 936   // or NULL if none.  The address type is conservatively wide.
 937   // Returns non-null for calls, membars, loads, stores, etc.
 938   // Returns TypePtr::BOTTOM if the node touches memory "broadly".
 939   virtual const class TypePtr *adr_type() const { return NULL; }
 940 
 941   // Return an existing node which computes the same function as this node.
 942   // The optimistic combined algorithm requires this to return a Node which
 943   // is a small number of steps away (e.g., one of my inputs).
 944   virtual Node* Identity(PhaseGVN* phase);
 945 
 946   // Return the set of values this Node can take on at runtime.
 947   virtual const Type* Value(PhaseGVN* phase) const;
 948 
 949   // Return a node which is more "ideal" than the current node.
 950   // The invariants on this call are subtle.  If in doubt, read the
 951   // treatise in node.cpp above the default implemention AND TEST WITH
 952   // +VerifyIterativeGVN!
 953   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
 954 
 955   // Some nodes have specific Ideal subgraph transformations only if they are
 956   // unique users of specific nodes. Such nodes should be put on IGVN worklist
 957   // for the transformations to happen.
 958   bool has_special_unique_user() const;
 959 
 960   // Skip Proj and CatchProj nodes chains. Check for Null and Top.
 961   Node* find_exact_control(Node* ctrl);
 962 
 963   // Check if 'this' node dominates or equal to 'sub'.
 964   bool dominates(Node* sub, Node_List &nlist);
 965 
 966 protected:
 967   bool remove_dead_region(PhaseGVN *phase, bool can_reshape);
 968 public:
 969 
 970   // See if there is valid pipeline info
 971   static  const Pipeline *pipeline_class();
 972   virtual const Pipeline *pipeline() const;
 973 
 974   // Compute the latency from the def to this instruction of the ith input node
 975   uint latency(uint i);
 976 
 977   // Hash & compare functions, for pessimistic value numbering
 978 
 979   // If the hash function returns the special sentinel value NO_HASH,
 980   // the node is guaranteed never to compare equal to any other node.
 981   // If we accidentally generate a hash with value NO_HASH the node
 982   // won't go into the table and we'll lose a little optimization.
 983   enum { NO_HASH = 0 };
 984   virtual uint hash() const;
 985   virtual uint cmp( const Node &n ) const;
 986 
 987   // Operation appears to be iteratively computed (such as an induction variable)
 988   // It is possible for this operation to return false for a loop-varying
 989   // value, if it appears (by local graph inspection) to be computed by a simple conditional.
 990   bool is_iteratively_computed();
 991 
 992   // Determine if a node is Counted loop induction variable.
 993   // The method is defined in loopnode.cpp.
 994   const Node* is_loop_iv() const;
 995 
 996   // Return a node with opcode "opc" and same inputs as "this" if one can
 997   // be found; Otherwise return NULL;
 998   Node* find_similar(int opc);
 999 
1000   // Return the unique control out if only one. Null if none or more than one.
1001   Node* unique_ctrl_out() const;
1002 
1003   // Set control or add control as precedence edge
1004   void ensure_control_or_add_prec(Node* c);
1005 
1006 //----------------- Code Generation
1007 
1008   // Ideal register class for Matching.  Zero means unmatched instruction
1009   // (these are cloned instead of converted to machine nodes).
1010   virtual uint ideal_reg() const;
1011 
1012   static const uint NotAMachineReg;   // must be > max. machine register
1013 
1014   // Do we Match on this edge index or not?  Generally false for Control
1015   // and true for everything else.  Weird for calls & returns.
1016   virtual uint match_edge(uint idx) const;
1017 
1018   // Register class output is returned in
1019   virtual const RegMask &out_RegMask() const;
1020   // Register class input is expected in
1021   virtual const RegMask &in_RegMask(uint) const;
1022   // Should we clone rather than spill this instruction?
1023   bool rematerialize() const;
1024 
1025   // Return JVM State Object if this Node carries debug info, or NULL otherwise
1026   virtual JVMState* jvms() const;
1027 
1028   // Print as assembly
1029   virtual void format( PhaseRegAlloc *, outputStream* st = tty ) const;
1030   // Emit bytes starting at parameter 'ptr'
1031   // Bump 'ptr' by the number of output bytes
1032   virtual void emit(CodeBuffer &cbuf, PhaseRegAlloc *ra_) const;
1033   // Size of instruction in bytes
1034   virtual uint size(PhaseRegAlloc *ra_) const;
1035 
1036   // Convenience function to extract an integer constant from a node.
1037   // If it is not an integer constant (either Con, CastII, or Mach),
1038   // return value_if_unknown.
1039   jint find_int_con(jint value_if_unknown) const {
1040     const TypeInt* t = find_int_type();
1041     return (t != NULL && t->is_con()) ? t->get_con() : value_if_unknown;
1042   }
1043   // Return the constant, knowing it is an integer constant already
1044   jint get_int() const {
1045     const TypeInt* t = find_int_type();
1046     guarantee(t != NULL, "must be con");
1047     return t->get_con();
1048   }
1049   // Here's where the work is done.  Can produce non-constant int types too.
1050   const TypeInt* find_int_type() const;
1051 
1052   // Same thing for long (and intptr_t, via type.hpp):
1053   jlong get_long() const {
1054     const TypeLong* t = find_long_type();
1055     guarantee(t != NULL, "must be con");
1056     return t->get_con();
1057   }
1058   jlong find_long_con(jint value_if_unknown) const {
1059     const TypeLong* t = find_long_type();
1060     return (t != NULL && t->is_con()) ? t->get_con() : value_if_unknown;
1061   }
1062   const TypeLong* find_long_type() const;
1063 
1064   const TypePtr* get_ptr_type() const;
1065 
1066   // These guys are called by code generated by ADLC:
1067   intptr_t get_ptr() const;
1068   intptr_t get_narrowcon() const;
1069   jdouble getd() const;
1070   jfloat getf() const;
1071 
1072   // Nodes which are pinned into basic blocks
1073   virtual bool pinned() const { return false; }
1074 
1075   // Nodes which use memory without consuming it, hence need antidependences
1076   // More specifically, needs_anti_dependence_check returns true iff the node
1077   // (a) does a load, and (b) does not perform a store (except perhaps to a
1078   // stack slot or some other unaliased location).
1079   bool needs_anti_dependence_check() const;
1080 
1081   // Return which operand this instruction may cisc-spill. In other words,
1082   // return operand position that can convert from reg to memory access
1083   virtual int cisc_operand() const { return AdlcVMDeps::Not_cisc_spillable; }
1084   bool is_cisc_alternate() const { return (_flags & Flag_is_cisc_alternate) != 0; }
1085 
1086 //----------------- Graph walking
1087 public:
1088   // Walk and apply member functions recursively.
1089   // Supplied (this) pointer is root.
1090   void walk(NFunc pre, NFunc post, void *env);
1091   static void nop(Node &, void*); // Dummy empty function
1092   static void packregion( Node &n, void* );
1093 private:
1094   void walk_(NFunc pre, NFunc post, void *env, VectorSet &visited);
1095 
1096 //----------------- Printing, etc
1097 public:
1098 #ifndef PRODUCT
1099   Node* find(int idx) const;         // Search the graph for the given idx.
1100   Node* find_ctrl(int idx) const;    // Search control ancestors for the given idx.
1101   void dump() const { dump("\n"); }  // Print this node.
1102   void dump(const char* suffix, bool mark = false, outputStream *st = tty) const; // Print this node.
1103   void dump(int depth) const;        // Print this node, recursively to depth d
1104   void dump_ctrl(int depth) const;   // Print control nodes, to depth d
1105   void dump_comp() const;            // Print this node in compact representation.
1106   // Print this node in compact representation.
1107   void dump_comp(const char* suffix, outputStream *st = tty) const;
1108   virtual void dump_req(outputStream *st = tty) const;    // Print required-edge info
1109   virtual void dump_prec(outputStream *st = tty) const;   // Print precedence-edge info
1110   virtual void dump_out(outputStream *st = tty) const;    // Print the output edge info
1111   virtual void dump_spec(outputStream *st) const {};      // Print per-node info
1112   // Print compact per-node info
1113   virtual void dump_compact_spec(outputStream *st) const { dump_spec(st); }
1114   void dump_related() const;             // Print related nodes (depends on node at hand).
1115   // Print related nodes up to given depths for input and output nodes.
1116   void dump_related(uint d_in, uint d_out) const;
1117   void dump_related_compact() const;     // Print related nodes in compact representation.
1118   // Collect related nodes.
1119   virtual void related(GrowableArray<Node*> *in_rel, GrowableArray<Node*> *out_rel, bool compact) const;
1120   // Collect nodes starting from this node, explicitly including/excluding control and data links.
1121   void collect_nodes(GrowableArray<Node*> *ns, int d, bool ctrl, bool data) const;
1122 
1123   // Node collectors, to be used in implementations of Node::rel().
1124   // Collect the entire data input graph. Include control inputs if requested.
1125   void collect_nodes_in_all_data(GrowableArray<Node*> *ns, bool ctrl) const;
1126   // Collect the entire control input graph. Include data inputs if requested.
1127   void collect_nodes_in_all_ctrl(GrowableArray<Node*> *ns, bool data) const;
1128   // Collect the entire output graph until hitting and including control nodes.
1129   void collect_nodes_out_all_ctrl_boundary(GrowableArray<Node*> *ns) const;
1130 
1131   void verify_edges(Unique_Node_List &visited); // Verify bi-directional edges
1132   void verify() const;               // Check Def-Use info for my subgraph
1133   static void verify_recur(const Node *n, int verify_depth, VectorSet &old_space, VectorSet &new_space);
1134 
1135   // This call defines a class-unique string used to identify class instances
1136   virtual const char *Name() const;
1137 
1138   void dump_format(PhaseRegAlloc *ra) const; // debug access to MachNode::format(...)
1139   // RegMask Print Functions
1140   void dump_in_regmask(int idx) { in_RegMask(idx).dump(); }
1141   void dump_out_regmask() { out_RegMask().dump(); }
1142   static bool in_dump() { return Compile::current()->_in_dump_cnt > 0; }
1143   void fast_dump() const {
1144     tty->print("%4d: %-17s", _idx, Name());
1145     for (uint i = 0; i < len(); i++)
1146       if (in(i))
1147         tty->print(" %4d", in(i)->_idx);
1148       else
1149         tty->print(" NULL");
1150     tty->print("\n");
1151   }
1152 #endif
1153 #ifdef ASSERT
1154   void verify_construction();
1155   bool verify_jvms(const JVMState* jvms) const;
1156   int  _debug_idx;                     // Unique value assigned to every node.
1157   int   debug_idx() const              { return _debug_idx; }
1158   void  set_debug_idx( int debug_idx ) { _debug_idx = debug_idx; }
1159 
1160   Node* _debug_orig;                   // Original version of this, if any.
1161   Node*  debug_orig() const            { return _debug_orig; }
1162   void   set_debug_orig(Node* orig);   // _debug_orig = orig
1163 
1164   int        _hash_lock;               // Barrier to modifications of nodes in the hash table
1165   void  enter_hash_lock() { ++_hash_lock; assert(_hash_lock < 99, "in too many hash tables?"); }
1166   void   exit_hash_lock() { --_hash_lock; assert(_hash_lock >= 0, "mispaired hash locks"); }
1167 
1168   static void init_NodeProperty();
1169 
1170   #if OPTO_DU_ITERATOR_ASSERT
1171   const Node* _last_del;               // The last deleted node.
1172   uint        _del_tick;               // Bumped when a deletion happens..
1173   #endif
1174 #endif
1175 };
1176 
1177 
1178 #ifndef PRODUCT
1179 
1180 // Used in debugging code to avoid walking across dead or uninitialized edges.
1181 inline bool NotANode(const Node* n) {
1182   if (n == NULL)                   return true;
1183   if (((intptr_t)n & 1) != 0)      return true;  // uninitialized, etc.
1184   if (*(address*)n == badAddress)  return true;  // kill by Node::destruct
1185   return false;
1186 }
1187 
1188 #endif
1189 
1190 
1191 //-----------------------------------------------------------------------------
1192 // Iterators over DU info, and associated Node functions.
1193 
1194 #if OPTO_DU_ITERATOR_ASSERT
1195 
1196 // Common code for assertion checking on DU iterators.
1197 class DUIterator_Common VALUE_OBJ_CLASS_SPEC {
1198 #ifdef ASSERT
1199  protected:
1200   bool         _vdui;               // cached value of VerifyDUIterators
1201   const Node*  _node;               // the node containing the _out array
1202   uint         _outcnt;             // cached node->_outcnt
1203   uint         _del_tick;           // cached node->_del_tick
1204   Node*        _last;               // last value produced by the iterator
1205 
1206   void sample(const Node* node);    // used by c'tor to set up for verifies
1207   void verify(const Node* node, bool at_end_ok = false);
1208   void verify_resync();
1209   void reset(const DUIterator_Common& that);
1210 
1211 // The VDUI_ONLY macro protects code conditionalized on VerifyDUIterators
1212   #define I_VDUI_ONLY(i,x) { if ((i)._vdui) { x; } }
1213 #else
1214   #define I_VDUI_ONLY(i,x) { }
1215 #endif //ASSERT
1216 };
1217 
1218 #define VDUI_ONLY(x)     I_VDUI_ONLY(*this, x)
1219 
1220 // Default DU iterator.  Allows appends onto the out array.
1221 // Allows deletion from the out array only at the current point.
1222 // Usage:
1223 //  for (DUIterator i = x->outs(); x->has_out(i); i++) {
1224 //    Node* y = x->out(i);
1225 //    ...
1226 //  }
1227 // Compiles in product mode to a unsigned integer index, which indexes
1228 // onto a repeatedly reloaded base pointer of x->_out.  The loop predicate
1229 // also reloads x->_outcnt.  If you delete, you must perform "--i" just
1230 // before continuing the loop.  You must delete only the last-produced
1231 // edge.  You must delete only a single copy of the last-produced edge,
1232 // or else you must delete all copies at once (the first time the edge
1233 // is produced by the iterator).
1234 class DUIterator : public DUIterator_Common {
1235   friend class Node;
1236 
1237   // This is the index which provides the product-mode behavior.
1238   // Whatever the product-mode version of the system does to the
1239   // DUI index is done to this index.  All other fields in
1240   // this class are used only for assertion checking.
1241   uint         _idx;
1242 
1243   #ifdef ASSERT
1244   uint         _refresh_tick;    // Records the refresh activity.
1245 
1246   void sample(const Node* node); // Initialize _refresh_tick etc.
1247   void verify(const Node* node, bool at_end_ok = false);
1248   void verify_increment();       // Verify an increment operation.
1249   void verify_resync();          // Verify that we can back up over a deletion.
1250   void verify_finish();          // Verify that the loop terminated properly.
1251   void refresh();                // Resample verification info.
1252   void reset(const DUIterator& that);  // Resample after assignment.
1253   #endif
1254 
1255   DUIterator(const Node* node, int dummy_to_avoid_conversion)
1256     { _idx = 0;                         debug_only(sample(node)); }
1257 
1258  public:
1259   // initialize to garbage; clear _vdui to disable asserts
1260   DUIterator()
1261     { /*initialize to garbage*/         debug_only(_vdui = false); }
1262 
1263   void operator++(int dummy_to_specify_postfix_op)
1264     { _idx++;                           VDUI_ONLY(verify_increment()); }
1265 
1266   void operator--()
1267     { VDUI_ONLY(verify_resync());       --_idx; }
1268 
1269   ~DUIterator()
1270     { VDUI_ONLY(verify_finish()); }
1271 
1272   void operator=(const DUIterator& that)
1273     { _idx = that._idx;                 debug_only(reset(that)); }
1274 };
1275 
1276 DUIterator Node::outs() const
1277   { return DUIterator(this, 0); }
1278 DUIterator& Node::refresh_out_pos(DUIterator& i) const
1279   { I_VDUI_ONLY(i, i.refresh());        return i; }
1280 bool Node::has_out(DUIterator& i) const
1281   { I_VDUI_ONLY(i, i.verify(this,true));return i._idx < _outcnt; }
1282 Node*    Node::out(DUIterator& i) const
1283   { I_VDUI_ONLY(i, i.verify(this));     return debug_only(i._last=) _out[i._idx]; }
1284 
1285 
1286 // Faster DU iterator.  Disallows insertions into the out array.
1287 // Allows deletion from the out array only at the current point.
1288 // Usage:
1289 //  for (DUIterator_Fast imax, i = x->fast_outs(imax); i < imax; i++) {
1290 //    Node* y = x->fast_out(i);
1291 //    ...
1292 //  }
1293 // Compiles in product mode to raw Node** pointer arithmetic, with
1294 // no reloading of pointers from the original node x.  If you delete,
1295 // you must perform "--i; --imax" just before continuing the loop.
1296 // If you delete multiple copies of the same edge, you must decrement
1297 // imax, but not i, multiple times:  "--i, imax -= num_edges".
1298 class DUIterator_Fast : public DUIterator_Common {
1299   friend class Node;
1300   friend class DUIterator_Last;
1301 
1302   // This is the pointer which provides the product-mode behavior.
1303   // Whatever the product-mode version of the system does to the
1304   // DUI pointer is done to this pointer.  All other fields in
1305   // this class are used only for assertion checking.
1306   Node**       _outp;
1307 
1308   #ifdef ASSERT
1309   void verify(const Node* node, bool at_end_ok = false);
1310   void verify_limit();
1311   void verify_resync();
1312   void verify_relimit(uint n);
1313   void reset(const DUIterator_Fast& that);
1314   #endif
1315 
1316   // Note:  offset must be signed, since -1 is sometimes passed
1317   DUIterator_Fast(const Node* node, ptrdiff_t offset)
1318     { _outp = node->_out + offset;      debug_only(sample(node)); }
1319 
1320  public:
1321   // initialize to garbage; clear _vdui to disable asserts
1322   DUIterator_Fast()
1323     { /*initialize to garbage*/         debug_only(_vdui = false); }
1324 
1325   void operator++(int dummy_to_specify_postfix_op)
1326     { _outp++;                          VDUI_ONLY(verify(_node, true)); }
1327 
1328   void operator--()
1329     { VDUI_ONLY(verify_resync());       --_outp; }
1330 
1331   void operator-=(uint n)   // applied to the limit only
1332     { _outp -= n;           VDUI_ONLY(verify_relimit(n));  }
1333 
1334   bool operator<(DUIterator_Fast& limit) {
1335     I_VDUI_ONLY(*this, this->verify(_node, true));
1336     I_VDUI_ONLY(limit, limit.verify_limit());
1337     return _outp < limit._outp;
1338   }
1339 
1340   void operator=(const DUIterator_Fast& that)
1341     { _outp = that._outp;               debug_only(reset(that)); }
1342 };
1343 
1344 DUIterator_Fast Node::fast_outs(DUIterator_Fast& imax) const {
1345   // Assign a limit pointer to the reference argument:
1346   imax = DUIterator_Fast(this, (ptrdiff_t)_outcnt);
1347   // Return the base pointer:
1348   return DUIterator_Fast(this, 0);
1349 }
1350 Node* Node::fast_out(DUIterator_Fast& i) const {
1351   I_VDUI_ONLY(i, i.verify(this));
1352   return debug_only(i._last=) *i._outp;
1353 }
1354 
1355 
1356 // Faster DU iterator.  Requires each successive edge to be removed.
1357 // Does not allow insertion of any edges.
1358 // Usage:
1359 //  for (DUIterator_Last imin, i = x->last_outs(imin); i >= imin; i -= num_edges) {
1360 //    Node* y = x->last_out(i);
1361 //    ...
1362 //  }
1363 // Compiles in product mode to raw Node** pointer arithmetic, with
1364 // no reloading of pointers from the original node x.
1365 class DUIterator_Last : private DUIterator_Fast {
1366   friend class Node;
1367 
1368   #ifdef ASSERT
1369   void verify(const Node* node, bool at_end_ok = false);
1370   void verify_limit();
1371   void verify_step(uint num_edges);
1372   #endif
1373 
1374   // Note:  offset must be signed, since -1 is sometimes passed
1375   DUIterator_Last(const Node* node, ptrdiff_t offset)
1376     : DUIterator_Fast(node, offset) { }
1377 
1378   void operator++(int dummy_to_specify_postfix_op) {} // do not use
1379   void operator<(int)                              {} // do not use
1380 
1381  public:
1382   DUIterator_Last() { }
1383   // initialize to garbage
1384 
1385   void operator--()
1386     { _outp--;              VDUI_ONLY(verify_step(1));  }
1387 
1388   void operator-=(uint n)
1389     { _outp -= n;           VDUI_ONLY(verify_step(n));  }
1390 
1391   bool operator>=(DUIterator_Last& limit) {
1392     I_VDUI_ONLY(*this, this->verify(_node, true));
1393     I_VDUI_ONLY(limit, limit.verify_limit());
1394     return _outp >= limit._outp;
1395   }
1396 
1397   void operator=(const DUIterator_Last& that)
1398     { DUIterator_Fast::operator=(that); }
1399 };
1400 
1401 DUIterator_Last Node::last_outs(DUIterator_Last& imin) const {
1402   // Assign a limit pointer to the reference argument:
1403   imin = DUIterator_Last(this, 0);
1404   // Return the initial pointer:
1405   return DUIterator_Last(this, (ptrdiff_t)_outcnt - 1);
1406 }
1407 Node* Node::last_out(DUIterator_Last& i) const {
1408   I_VDUI_ONLY(i, i.verify(this));
1409   return debug_only(i._last=) *i._outp;
1410 }
1411 
1412 #endif //OPTO_DU_ITERATOR_ASSERT
1413 
1414 #undef I_VDUI_ONLY
1415 #undef VDUI_ONLY
1416 
1417 // An Iterator that truly follows the iterator pattern.  Doesn't
1418 // support deletion but could be made to.
1419 //
1420 //   for (SimpleDUIterator i(n); i.has_next(); i.next()) {
1421 //     Node* m = i.get();
1422 //
1423 class SimpleDUIterator : public StackObj {
1424  private:
1425   Node* node;
1426   DUIterator_Fast i;
1427   DUIterator_Fast imax;
1428  public:
1429   SimpleDUIterator(Node* n): node(n), i(n->fast_outs(imax)) {}
1430   bool has_next() { return i < imax; }
1431   void next() { i++; }
1432   Node* get() { return node->fast_out(i); }
1433 };
1434 
1435 
1436 //-----------------------------------------------------------------------------
1437 // Map dense integer indices to Nodes.  Uses classic doubling-array trick.
1438 // Abstractly provides an infinite array of Node*'s, initialized to NULL.
1439 // Note that the constructor just zeros things, and since I use Arena
1440 // allocation I do not need a destructor to reclaim storage.
1441 class Node_Array : public ResourceObj {
1442   friend class VMStructs;
1443 protected:
1444   Arena *_a;                    // Arena to allocate in
1445   uint   _max;
1446   Node **_nodes;
1447   void   grow( uint i );        // Grow array node to fit
1448 public:
1449   Node_Array(Arena *a) : _a(a), _max(OptoNodeListSize) {
1450     _nodes = NEW_ARENA_ARRAY( a, Node *, OptoNodeListSize );
1451     for( int i = 0; i < OptoNodeListSize; i++ ) {
1452       _nodes[i] = NULL;
1453     }
1454   }
1455 
1456   Node_Array(Node_Array *na) : _a(na->_a), _max(na->_max), _nodes(na->_nodes) {}
1457   Node *operator[] ( uint i ) const // Lookup, or NULL for not mapped
1458   { return (i<_max) ? _nodes[i] : (Node*)NULL; }
1459   Node *at( uint i ) const { assert(i<_max,"oob"); return _nodes[i]; }
1460   Node **adr() { return _nodes; }
1461   // Extend the mapping: index i maps to Node *n.
1462   void map( uint i, Node *n ) { if( i>=_max ) grow(i); _nodes[i] = n; }
1463   void insert( uint i, Node *n );
1464   void remove( uint i );        // Remove, preserving order
1465   void sort( C_sort_func_t func);
1466   void reset( Arena *new_a );   // Zap mapping to empty; reclaim storage
1467   void clear();                 // Set all entries to NULL, keep storage
1468   uint Size() const { return _max; }
1469   void dump() const;
1470 };
1471 
1472 class Node_List : public Node_Array {
1473   friend class VMStructs;
1474   uint _cnt;
1475 public:
1476   Node_List() : Node_Array(Thread::current()->resource_area()), _cnt(0) {}
1477   Node_List(Arena *a) : Node_Array(a), _cnt(0) {}
1478   bool contains(const Node* n) const {
1479     for (uint e = 0; e < size(); e++) {
1480       if (at(e) == n) return true;
1481     }
1482     return false;
1483   }
1484   void insert( uint i, Node *n ) { Node_Array::insert(i,n); _cnt++; }
1485   void remove( uint i ) { Node_Array::remove(i); _cnt--; }
1486   void push( Node *b ) { map(_cnt++,b); }
1487   void yank( Node *n );         // Find and remove
1488   Node *pop() { return _nodes[--_cnt]; }
1489   Node *rpop() { Node *b = _nodes[0]; _nodes[0]=_nodes[--_cnt]; return b;}
1490   void clear() { _cnt = 0; Node_Array::clear(); } // retain storage
1491   uint size() const { return _cnt; }
1492   void dump() const;
1493   void dump_simple() const;
1494 };
1495 
1496 //------------------------------Unique_Node_List-------------------------------
1497 class Unique_Node_List : public Node_List {
1498   friend class VMStructs;
1499   VectorSet _in_worklist;
1500   uint _clock_index;            // Index in list where to pop from next
1501 public:
1502   Unique_Node_List() : Node_List(), _in_worklist(Thread::current()->resource_area()), _clock_index(0) {}
1503   Unique_Node_List(Arena *a) : Node_List(a), _in_worklist(a), _clock_index(0) {}
1504 
1505   void remove( Node *n );
1506   bool member( Node *n ) { return _in_worklist.test(n->_idx) != 0; }
1507   VectorSet &member_set(){ return _in_worklist; }
1508 
1509   void push( Node *b ) {
1510     if( !_in_worklist.test_set(b->_idx) )
1511       Node_List::push(b);
1512   }
1513   Node *pop() {
1514     if( _clock_index >= size() ) _clock_index = 0;
1515     Node *b = at(_clock_index);
1516     map( _clock_index, Node_List::pop());
1517     if (size() != 0) _clock_index++; // Always start from 0
1518     _in_worklist >>= b->_idx;
1519     return b;
1520   }
1521   Node *remove( uint i ) {
1522     Node *b = Node_List::at(i);
1523     _in_worklist >>= b->_idx;
1524     map(i,Node_List::pop());
1525     return b;
1526   }
1527   void yank( Node *n ) { _in_worklist >>= n->_idx; Node_List::yank(n); }
1528   void  clear() {
1529     _in_worklist.Clear();        // Discards storage but grows automatically
1530     Node_List::clear();
1531     _clock_index = 0;
1532   }
1533 
1534   // Used after parsing to remove useless nodes before Iterative GVN
1535   void remove_useless_nodes(VectorSet &useful);
1536 
1537 #ifndef PRODUCT
1538   void print_set() const { _in_worklist.print(); }
1539 #endif
1540 };
1541 
1542 // Inline definition of Compile::record_for_igvn must be deferred to this point.
1543 inline void Compile::record_for_igvn(Node* n) {
1544   _for_igvn->push(n);
1545 }
1546 
1547 //------------------------------Node_Stack-------------------------------------
1548 class Node_Stack {
1549   friend class VMStructs;
1550 protected:
1551   struct INode {
1552     Node *node; // Processed node
1553     uint  indx; // Index of next node's child
1554   };
1555   INode *_inode_top; // tos, stack grows up
1556   INode *_inode_max; // End of _inodes == _inodes + _max
1557   INode *_inodes;    // Array storage for the stack
1558   Arena *_a;         // Arena to allocate in
1559   void grow();
1560 public:
1561   Node_Stack(int size) {
1562     size_t max = (size > OptoNodeListSize) ? size : OptoNodeListSize;
1563     _a = Thread::current()->resource_area();
1564     _inodes = NEW_ARENA_ARRAY( _a, INode, max );
1565     _inode_max = _inodes + max;
1566     _inode_top = _inodes - 1; // stack is empty
1567   }
1568 
1569   Node_Stack(Arena *a, int size) : _a(a) {
1570     size_t max = (size > OptoNodeListSize) ? size : OptoNodeListSize;
1571     _inodes = NEW_ARENA_ARRAY( _a, INode, max );
1572     _inode_max = _inodes + max;
1573     _inode_top = _inodes - 1; // stack is empty
1574   }
1575 
1576   void pop() {
1577     assert(_inode_top >= _inodes, "node stack underflow");
1578     --_inode_top;
1579   }
1580   void push(Node *n, uint i) {
1581     ++_inode_top;
1582     if (_inode_top >= _inode_max) grow();
1583     INode *top = _inode_top; // optimization
1584     top->node = n;
1585     top->indx = i;
1586   }
1587   Node *node() const {
1588     return _inode_top->node;
1589   }
1590   Node* node_at(uint i) const {
1591     assert(_inodes + i <= _inode_top, "in range");
1592     return _inodes[i].node;
1593   }
1594   uint index() const {
1595     return _inode_top->indx;
1596   }
1597   uint index_at(uint i) const {
1598     assert(_inodes + i <= _inode_top, "in range");
1599     return _inodes[i].indx;
1600   }
1601   void set_node(Node *n) {
1602     _inode_top->node = n;
1603   }
1604   void set_index(uint i) {
1605     _inode_top->indx = i;
1606   }
1607   uint size_max() const { return (uint)pointer_delta(_inode_max, _inodes,  sizeof(INode)); } // Max size
1608   uint size() const { return (uint)pointer_delta((_inode_top+1), _inodes,  sizeof(INode)); } // Current size
1609   bool is_nonempty() const { return (_inode_top >= _inodes); }
1610   bool is_empty() const { return (_inode_top < _inodes); }
1611   void clear() { _inode_top = _inodes - 1; } // retain storage
1612 
1613   // Node_Stack is used to map nodes.
1614   Node* find(uint idx) const;
1615 };
1616 
1617 
1618 //-----------------------------Node_Notes--------------------------------------
1619 // Debugging or profiling annotations loosely and sparsely associated
1620 // with some nodes.  See Compile::node_notes_at for the accessor.
1621 class Node_Notes VALUE_OBJ_CLASS_SPEC {
1622   friend class VMStructs;
1623   JVMState* _jvms;
1624 
1625 public:
1626   Node_Notes(JVMState* jvms = NULL) {
1627     _jvms = jvms;
1628   }
1629 
1630   JVMState* jvms()            { return _jvms; }
1631   void  set_jvms(JVMState* x) {        _jvms = x; }
1632 
1633   // True if there is nothing here.
1634   bool is_clear() {
1635     return (_jvms == NULL);
1636   }
1637 
1638   // Make there be nothing here.
1639   void clear() {
1640     _jvms = NULL;
1641   }
1642 
1643   // Make a new, clean node notes.
1644   static Node_Notes* make(Compile* C) {
1645     Node_Notes* nn = NEW_ARENA_ARRAY(C->comp_arena(), Node_Notes, 1);
1646     nn->clear();
1647     return nn;
1648   }
1649 
1650   Node_Notes* clone(Compile* C) {
1651     Node_Notes* nn = NEW_ARENA_ARRAY(C->comp_arena(), Node_Notes, 1);
1652     (*nn) = (*this);
1653     return nn;
1654   }
1655 
1656   // Absorb any information from source.
1657   bool update_from(Node_Notes* source) {
1658     bool changed = false;
1659     if (source != NULL) {
1660       if (source->jvms() != NULL) {
1661         set_jvms(source->jvms());
1662         changed = true;
1663       }
1664     }
1665     return changed;
1666   }
1667 };
1668 
1669 // Inlined accessors for Compile::node_nodes that require the preceding class:
1670 inline Node_Notes*
1671 Compile::locate_node_notes(GrowableArray<Node_Notes*>* arr,
1672                            int idx, bool can_grow) {
1673   assert(idx >= 0, "oob");
1674   int block_idx = (idx >> _log2_node_notes_block_size);
1675   int grow_by = (block_idx - (arr == NULL? 0: arr->length()));
1676   if (grow_by >= 0) {
1677     if (!can_grow)  return NULL;
1678     grow_node_notes(arr, grow_by + 1);
1679   }
1680   // (Every element of arr is a sub-array of length _node_notes_block_size.)
1681   return arr->at(block_idx) + (idx & (_node_notes_block_size-1));
1682 }
1683 
1684 inline bool
1685 Compile::set_node_notes_at(int idx, Node_Notes* value) {
1686   if (value == NULL || value->is_clear())
1687     return false;  // nothing to write => write nothing
1688   Node_Notes* loc = locate_node_notes(_node_note_array, idx, true);
1689   assert(loc != NULL, "");
1690   return loc->update_from(value);
1691 }
1692 
1693 
1694 //------------------------------TypeNode---------------------------------------
1695 // Node with a Type constant.
1696 class TypeNode : public Node {
1697 protected:
1698   virtual uint hash() const;    // Check the type
1699   virtual uint cmp( const Node &n ) const;
1700   virtual uint size_of() const; // Size is bigger
1701   const Type* const _type;
1702 public:
1703   void set_type(const Type* t) {
1704     assert(t != NULL, "sanity");
1705     debug_only(uint check_hash = (VerifyHashTableKeys && _hash_lock) ? hash() : NO_HASH);
1706     *(const Type**)&_type = t;   // cast away const-ness
1707     // If this node is in the hash table, make sure it doesn't need a rehash.
1708     assert(check_hash == NO_HASH || check_hash == hash(), "type change must preserve hash code");
1709   }
1710   const Type* type() const { assert(_type != NULL, "sanity"); return _type; };
1711   TypeNode( const Type *t, uint required ) : Node(required), _type(t) {
1712     init_class_id(Class_Type);
1713   }
1714   virtual const Type* Value(PhaseGVN* phase) const;
1715   virtual const Type *bottom_type() const;
1716   virtual       uint  ideal_reg() const;
1717 #ifndef PRODUCT
1718   virtual void dump_spec(outputStream *st) const;
1719   virtual void dump_compact_spec(outputStream *st) const;
1720 #endif
1721 };
1722 
1723 #endif // SHARE_VM_OPTO_NODE_HPP
--- EOF ---