1 /*
   2  * Copyright (c) 1997, 2012, 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 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 CatchNode;
  55 class CatchProjNode;
  56 class CheckCastPPNode;
  57 class ClearArrayNode;
  58 class CmpNode;
  59 class CodeBuffer;
  60 class ConstraintCastNode;
  61 class ConNode;
  62 class CountedLoopNode;
  63 class CountedLoopEndNode;
  64 class DecodeNarrowPtrNode;
  65 class DecodeNNode;
  66 class DecodeNKlassNode;
  67 class EncodeNarrowPtrNode;
  68 class EncodePNode;
  69 class EncodePKlassNode;
  70 class FastLockNode;
  71 class FastUnlockNode;
  72 class IfNode;
  73 class IfFalseNode;
  74 class IfTrueNode;
  75 class InitializeNode;
  76 class JVMState;
  77 class JumpNode;
  78 class JumpProjNode;
  79 class LoadNode;
  80 class LoadStoreNode;
  81 class LockNode;
  82 class LoopNode;
  83 class MachBranchNode;
  84 class MachCallDynamicJavaNode;
  85 class MachCallJavaNode;
  86 class MachCallLeafNode;
  87 class MachCallNode;
  88 class MachCallRuntimeNode;
  89 class MachCallStaticJavaNode;
  90 class MachConstantBaseNode;
  91 class MachConstantNode;
  92 class MachGotoNode;
  93 class MachIfNode;
  94 class MachNode;
  95 class MachNullCheckNode;
  96 class MachProjNode;
  97 class MachReturnNode;
  98 class MachSafePointNode;
  99 class MachSpillCopyNode;
 100 class MachTempNode;
 101 class Matcher;
 102 class MemBarNode;
 103 class MemBarStoreStoreNode;
 104 class MemNode;
 105 class MergeMemNode;
 106 class MulNode;
 107 class MultiNode;
 108 class MultiBranchNode;
 109 class NeverBranchNode;
 110 class Node;
 111 class Node_Array;
 112 class Node_List;
 113 class Node_Stack;
 114 class NullCheckNode;
 115 class OopMap;
 116 class ParmNode;
 117 class PCTableNode;
 118 class PhaseCCP;
 119 class PhaseGVN;
 120 class PhaseIterGVN;
 121 class PhaseRegAlloc;
 122 class PhaseTransform;
 123 class PhaseValues;
 124 class PhiNode;
 125 class Pipeline;
 126 class ProjNode;
 127 class RegMask;
 128 class RegionNode;
 129 class RootNode;
 130 class SafePointNode;
 131 class SafePointScalarObjectNode;
 132 class StartNode;
 133 class State;
 134 class StoreNode;
 135 class SubNode;
 136 class Type;
 137 class TypeNode;
 138 class UnlockNode;
 139 class VectorNode;
 140 class LoadVectorNode;
 141 class StoreVectorNode;
 142 class VectorSet;
 143 typedef void (*NFunc)(Node&,void*);
 144 extern "C" {
 145   typedef int (*C_sort_func_t)(const void *, const void *);
 146 }
 147 
 148 // The type of all node counts and indexes.
 149 // It must hold at least 16 bits, but must also be fast to load and store.
 150 // This type, if less than 32 bits, could limit the number of possible nodes.
 151 // (To make this type platform-specific, move to globalDefinitions_xxx.hpp.)
 152 typedef unsigned int node_idx_t;
 153 
 154 
 155 #ifndef OPTO_DU_ITERATOR_ASSERT
 156 #ifdef ASSERT
 157 #define OPTO_DU_ITERATOR_ASSERT 1
 158 #else
 159 #define OPTO_DU_ITERATOR_ASSERT 0
 160 #endif
 161 #endif //OPTO_DU_ITERATOR_ASSERT
 162 
 163 #if OPTO_DU_ITERATOR_ASSERT
 164 class DUIterator;
 165 class DUIterator_Fast;
 166 class DUIterator_Last;
 167 #else
 168 typedef uint   DUIterator;
 169 typedef Node** DUIterator_Fast;
 170 typedef Node** DUIterator_Last;
 171 #endif
 172 
 173 // Node Sentinel
 174 #define NodeSentinel (Node*)-1
 175 
 176 // Unknown count frequency
 177 #define COUNT_UNKNOWN (-1.0f)
 178 
 179 //------------------------------Node-------------------------------------------
 180 // Nodes define actions in the program.  They create values, which have types.
 181 // They are both vertices in a directed graph and program primitives.  Nodes
 182 // are labeled; the label is the "opcode", the primitive function in the lambda
 183 // calculus sense that gives meaning to the Node.  Node inputs are ordered (so
 184 // that "a-b" is different from "b-a").  The inputs to a Node are the inputs to
 185 // the Node's function.  These inputs also define a Type equation for the Node.
 186 // Solving these Type equations amounts to doing dataflow analysis.
 187 // Control and data are uniformly represented in the graph.  Finally, Nodes
 188 // have a unique dense integer index which is used to index into side arrays
 189 // whenever I have phase-specific information.
 190 
 191 class Node {
 192   friend class VMStructs;
 193 
 194   // Lots of restrictions on cloning Nodes
 195   Node(const Node&);            // not defined; linker error to use these
 196   Node &operator=(const Node &rhs);
 197 
 198 public:
 199   friend class Compile;
 200   #if OPTO_DU_ITERATOR_ASSERT
 201   friend class DUIterator_Common;
 202   friend class DUIterator;
 203   friend class DUIterator_Fast;
 204   friend class DUIterator_Last;
 205   #endif
 206 
 207   // Because Nodes come and go, I define an Arena of Node structures to pull
 208   // from.  This should allow fast access to node creation & deletion.  This
 209   // field is a local cache of a value defined in some "program fragment" for
 210   // which these Nodes are just a part of.
 211 
 212   // New Operator that takes a Compile pointer, this will eventually
 213   // be the "new" New operator.
 214   inline void* operator new( size_t x, Compile* C) {
 215     Node* n = (Node*)C->node_arena()->Amalloc_D(x);
 216 #ifdef ASSERT
 217     n->_in = (Node**)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, err_msg_res("oob: i=%d, _max=%d", i, _max)); 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   // Check whether node has become unreachable
 381   bool is_unreachable(PhaseIterGVN &igvn) const;
 382 
 383   // Set a required input edge, also updates corresponding output edge
 384   void add_req( Node *n ); // Append a NEW required input
 385   void add_req_batch( Node* n, uint m ); // Append m NEW required inputs (all n).
 386   void del_req( uint idx ); // Delete required edge & compact
 387   void del_req_ordered( uint idx ); // Delete required edge & compact with preserved order
 388   void ins_req( uint i, Node *n ); // Insert a NEW required input
 389   void set_req( uint i, Node *n ) {
 390     assert( is_not_dead(n), "can not use dead node");
 391     assert( i < _cnt, err_msg_res("oob: i=%d, _cnt=%d", i, _cnt));
 392     assert( !VerifyHashTableKeys || _hash_lock == 0,
 393             "remove node from hash table before modifying it");
 394     Node** p = &_in[i];    // cache this._in, across the del_out call
 395     if (*p != NULL)  (*p)->del_out((Node *)this);
 396     (*p) = n;
 397     if (n != NULL)      n->add_out((Node *)this);
 398   }
 399   // Light version of set_req() to init inputs after node creation.
 400   void init_req( uint i, Node *n ) {
 401     assert( i == 0 && this == n ||
 402             is_not_dead(n), "can not use dead node");
 403     assert( i < _cnt, "oob");
 404     assert( !VerifyHashTableKeys || _hash_lock == 0,
 405             "remove node from hash table before modifying it");
 406     assert( _in[i] == NULL, "sanity");
 407     _in[i] = n;
 408     if (n != NULL)      n->add_out((Node *)this);
 409   }
 410   // Find first occurrence of n among my edges:
 411   int find_edge(Node* n);
 412   int replace_edge(Node* old, Node* neww);
 413   int replace_edges_in_range(Node* old, Node* neww, int start, int end);
 414   // NULL out all inputs to eliminate incoming Def-Use edges.
 415   // Return the number of edges between 'n' and 'this'
 416   int  disconnect_inputs(Node *n, Compile *c);
 417 
 418   // Quickly, return true if and only if I am Compile::current()->top().
 419   bool is_top() const {
 420     assert((this == (Node*) Compile::current()->top()) == (_out == NULL), "");
 421     return (_out == NULL);
 422   }
 423   // Reaffirm invariants for is_top.  (Only from Compile::set_cached_top_node.)
 424   void setup_is_top();
 425 
 426   // Strip away casting.  (It is depth-limited.)
 427   Node* uncast() const;
 428   // Return whether two Nodes are equivalent, after stripping casting.
 429   bool eqv_uncast(const Node* n) const {
 430     return (this->uncast() == n->uncast());
 431   }
 432 
 433 private:
 434   static Node* uncast_helper(const Node* n);
 435 
 436   // Add an output edge to the end of the list
 437   void add_out( Node *n ) {
 438     if (is_top())  return;
 439     if( _outcnt == _outmax ) out_grow(_outcnt);
 440     _out[_outcnt++] = n;
 441   }
 442   // Delete an output edge
 443   void del_out( Node *n ) {
 444     if (is_top())  return;
 445     Node** outp = &_out[_outcnt];
 446     // Find and remove n
 447     do {
 448       assert(outp > _out, "Missing Def-Use edge");
 449     } while (*--outp != n);
 450     *outp = _out[--_outcnt];
 451     // Smash the old edge so it can't be used accidentally.
 452     debug_only(_out[_outcnt] = (Node *)(uintptr_t)0xdeadbeef);
 453     // Record that a change happened here.
 454     #if OPTO_DU_ITERATOR_ASSERT
 455     debug_only(_last_del = n; ++_del_tick);
 456     #endif
 457   }
 458 
 459 public:
 460   // Globally replace this node by a given new node, updating all uses.
 461   void replace_by(Node* new_node);
 462   // Globally replace this node by a given new node, updating all uses
 463   // and cutting input edges of old node.
 464   void subsume_by(Node* new_node, Compile* c) {
 465     replace_by(new_node);
 466     disconnect_inputs(NULL, c);
 467   }
 468   void set_req_X( uint i, Node *n, PhaseIterGVN *igvn );
 469   // Find the one non-null required input.  RegionNode only
 470   Node *nonnull_req() const;
 471   // Add or remove precedence edges
 472   void add_prec( Node *n );
 473   void rm_prec( uint i );
 474   void set_prec( uint i, Node *n ) {
 475     assert( is_not_dead(n), "can not use dead node");
 476     assert( i >= _cnt, "not a precedence edge");
 477     if (_in[i] != NULL) _in[i]->del_out((Node *)this);
 478     _in[i] = n;
 479     if (n != NULL) n->add_out((Node *)this);
 480   }
 481   // Set this node's index, used by cisc_version to replace current node
 482   void set_idx(uint new_idx) {
 483     const node_idx_t* ref = &_idx;
 484     *(node_idx_t*)ref = new_idx;
 485   }
 486   // Swap input edge order.  (Edge indexes i1 and i2 are usually 1 and 2.)
 487   void swap_edges(uint i1, uint i2) {
 488     debug_only(uint check_hash = (VerifyHashTableKeys && _hash_lock) ? hash() : NO_HASH);
 489     // Def-Use info is unchanged
 490     Node* n1 = in(i1);
 491     Node* n2 = in(i2);
 492     _in[i1] = n2;
 493     _in[i2] = n1;
 494     // If this node is in the hash table, make sure it doesn't need a rehash.
 495     assert(check_hash == NO_HASH || check_hash == hash(), "edge swap must preserve hash code");
 496   }
 497 
 498   // Iterators over input Nodes for a Node X are written as:
 499   // for( i = 0; i < X.req(); i++ ) ... X[i] ...
 500   // NOTE: Required edges can contain embedded NULL pointers.
 501 
 502 //----------------- Other Node Properties
 503 
 504   // Generate class id for some ideal nodes to avoid virtual query
 505   // methods is_<Node>().
 506   // Class id is the set of bits corresponded to the node class and all its
 507   // super classes so that queries for super classes are also valid.
 508   // Subclasses of the same super class have different assigned bit
 509   // (the third parameter in the macro DEFINE_CLASS_ID).
 510   // Classes with deeper hierarchy are declared first.
 511   // Classes with the same hierarchy depth are sorted by usage frequency.
 512   //
 513   // The query method masks the bits to cut off bits of subclasses
 514   // and then compare the result with the class id
 515   // (see the macro DEFINE_CLASS_QUERY below).
 516   //
 517   //  Class_MachCall=30, ClassMask_MachCall=31
 518   // 12               8               4               0
 519   //  0   0   0   0   0   0   0   0   1   1   1   1   0
 520   //                                  |   |   |   |
 521   //                                  |   |   |   Bit_Mach=2
 522   //                                  |   |   Bit_MachReturn=4
 523   //                                  |   Bit_MachSafePoint=8
 524   //                                  Bit_MachCall=16
 525   //
 526   //  Class_CountedLoop=56, ClassMask_CountedLoop=63
 527   // 12               8               4               0
 528   //  0   0   0   0   0   0   0   1   1   1   0   0   0
 529   //                              |   |   |
 530   //                              |   |   Bit_Region=8
 531   //                              |   Bit_Loop=16
 532   //                              Bit_CountedLoop=32
 533 
 534   #define DEFINE_CLASS_ID(cl, supcl, subn) \
 535   Bit_##cl = (Class_##supcl == 0) ? 1 << subn : (Bit_##supcl) << (1 + subn) , \
 536   Class_##cl = Class_##supcl + Bit_##cl , \
 537   ClassMask_##cl = ((Bit_##cl << 1) - 1) ,
 538 
 539   // This enum is used only for C2 ideal and mach nodes with is_<node>() methods
 540   // so that it's values fits into 16 bits.
 541   enum NodeClasses {
 542     Bit_Node   = 0x0000,
 543     Class_Node = 0x0000,
 544     ClassMask_Node = 0xFFFF,
 545 
 546     DEFINE_CLASS_ID(Multi, Node, 0)
 547       DEFINE_CLASS_ID(SafePoint, Multi, 0)
 548         DEFINE_CLASS_ID(Call,      SafePoint, 0)
 549           DEFINE_CLASS_ID(CallJava,         Call, 0)
 550             DEFINE_CLASS_ID(CallStaticJava,   CallJava, 0)
 551             DEFINE_CLASS_ID(CallDynamicJava,  CallJava, 1)
 552           DEFINE_CLASS_ID(CallRuntime,      Call, 1)
 553             DEFINE_CLASS_ID(CallLeaf,         CallRuntime, 0)
 554           DEFINE_CLASS_ID(Allocate,         Call, 2)
 555             DEFINE_CLASS_ID(AllocateArray,    Allocate, 0)
 556           DEFINE_CLASS_ID(AbstractLock,     Call, 3)
 557             DEFINE_CLASS_ID(Lock,             AbstractLock, 0)
 558             DEFINE_CLASS_ID(Unlock,           AbstractLock, 1)
 559       DEFINE_CLASS_ID(MultiBranch, Multi, 1)
 560         DEFINE_CLASS_ID(PCTable,     MultiBranch, 0)
 561           DEFINE_CLASS_ID(Catch,       PCTable, 0)
 562           DEFINE_CLASS_ID(Jump,        PCTable, 1)
 563         DEFINE_CLASS_ID(If,          MultiBranch, 1)
 564           DEFINE_CLASS_ID(CountedLoopEnd, If, 0)
 565         DEFINE_CLASS_ID(NeverBranch, MultiBranch, 2)
 566       DEFINE_CLASS_ID(Start,       Multi, 2)
 567       DEFINE_CLASS_ID(MemBar,      Multi, 3)
 568         DEFINE_CLASS_ID(Initialize,       MemBar, 0)
 569         DEFINE_CLASS_ID(MemBarStoreStore, MemBar, 1)
 570 
 571     DEFINE_CLASS_ID(Mach,  Node, 1)
 572       DEFINE_CLASS_ID(MachReturn, Mach, 0)
 573         DEFINE_CLASS_ID(MachSafePoint, MachReturn, 0)
 574           DEFINE_CLASS_ID(MachCall, MachSafePoint, 0)
 575             DEFINE_CLASS_ID(MachCallJava,         MachCall, 0)
 576               DEFINE_CLASS_ID(MachCallStaticJava,   MachCallJava, 0)
 577               DEFINE_CLASS_ID(MachCallDynamicJava,  MachCallJava, 1)
 578             DEFINE_CLASS_ID(MachCallRuntime,      MachCall, 1)
 579               DEFINE_CLASS_ID(MachCallLeaf,         MachCallRuntime, 0)
 580       DEFINE_CLASS_ID(MachBranch, Mach, 1)
 581         DEFINE_CLASS_ID(MachIf,         MachBranch, 0)
 582         DEFINE_CLASS_ID(MachGoto,       MachBranch, 1)
 583         DEFINE_CLASS_ID(MachNullCheck,  MachBranch, 2)
 584       DEFINE_CLASS_ID(MachSpillCopy,    Mach, 2)
 585       DEFINE_CLASS_ID(MachTemp,         Mach, 3)
 586       DEFINE_CLASS_ID(MachConstantBase, Mach, 4)
 587       DEFINE_CLASS_ID(MachConstant,     Mach, 5)
 588 
 589     DEFINE_CLASS_ID(Type,  Node, 2)
 590       DEFINE_CLASS_ID(Phi,   Type, 0)
 591       DEFINE_CLASS_ID(ConstraintCast, Type, 1)
 592       DEFINE_CLASS_ID(CheckCastPP, Type, 2)
 593       DEFINE_CLASS_ID(CMove, Type, 3)
 594       DEFINE_CLASS_ID(SafePointScalarObject, Type, 4)
 595       DEFINE_CLASS_ID(DecodeNarrowPtr, Type, 5)
 596         DEFINE_CLASS_ID(DecodeN, DecodeNarrowPtr, 0)
 597         DEFINE_CLASS_ID(DecodeNKlass, DecodeNarrowPtr, 1)
 598       DEFINE_CLASS_ID(EncodeNarrowPtr, Type, 6)
 599         DEFINE_CLASS_ID(EncodeP, EncodeNarrowPtr, 0)
 600         DEFINE_CLASS_ID(EncodePKlass, EncodeNarrowPtr, 1)
 601 
 602     DEFINE_CLASS_ID(Proj,  Node, 3)
 603       DEFINE_CLASS_ID(CatchProj, Proj, 0)
 604       DEFINE_CLASS_ID(JumpProj,  Proj, 1)
 605       DEFINE_CLASS_ID(IfTrue,    Proj, 2)
 606       DEFINE_CLASS_ID(IfFalse,   Proj, 3)
 607       DEFINE_CLASS_ID(Parm,      Proj, 4)
 608       DEFINE_CLASS_ID(MachProj,  Proj, 5)
 609 
 610     DEFINE_CLASS_ID(Mem,   Node, 4)
 611       DEFINE_CLASS_ID(Load,  Mem, 0)
 612         DEFINE_CLASS_ID(LoadVector,  Load, 0)
 613       DEFINE_CLASS_ID(Store, Mem, 1)
 614         DEFINE_CLASS_ID(StoreVector, Store, 0)
 615       DEFINE_CLASS_ID(LoadStore, Mem, 2)
 616 
 617     DEFINE_CLASS_ID(Region, Node, 5)
 618       DEFINE_CLASS_ID(Loop, Region, 0)
 619         DEFINE_CLASS_ID(Root,        Loop, 0)
 620         DEFINE_CLASS_ID(CountedLoop, Loop, 1)
 621 
 622     DEFINE_CLASS_ID(Sub,   Node, 6)
 623       DEFINE_CLASS_ID(Cmp,   Sub, 0)
 624         DEFINE_CLASS_ID(FastLock,   Cmp, 0)
 625         DEFINE_CLASS_ID(FastUnlock, Cmp, 1)
 626 
 627     DEFINE_CLASS_ID(MergeMem, Node, 7)
 628     DEFINE_CLASS_ID(Bool,     Node, 8)
 629     DEFINE_CLASS_ID(AddP,     Node, 9)
 630     DEFINE_CLASS_ID(BoxLock,  Node, 10)
 631     DEFINE_CLASS_ID(Add,      Node, 11)
 632     DEFINE_CLASS_ID(Mul,      Node, 12)
 633     DEFINE_CLASS_ID(Vector,   Node, 13)
 634     DEFINE_CLASS_ID(ClearArray, Node, 14)
 635 
 636     _max_classes  = ClassMask_ClearArray
 637   };
 638   #undef DEFINE_CLASS_ID
 639 
 640   // Flags are sorted by usage frequency.
 641   enum NodeFlags {
 642     Flag_is_Copy             = 0x01, // should be first bit to avoid shift
 643     Flag_rematerialize       = Flag_is_Copy << 1,
 644     Flag_needs_anti_dependence_check = Flag_rematerialize << 1,
 645     Flag_is_macro            = Flag_needs_anti_dependence_check << 1,
 646     Flag_is_Con              = Flag_is_macro << 1,
 647     Flag_is_cisc_alternate   = Flag_is_Con << 1,
 648     Flag_is_dead_loop_safe   = Flag_is_cisc_alternate << 1,
 649     Flag_may_be_short_branch = Flag_is_dead_loop_safe << 1,
 650     Flag_avoid_back_to_back  = Flag_may_be_short_branch << 1,
 651     Flag_has_call            = Flag_avoid_back_to_back << 1,
 652     Flag_is_expensive        = Flag_has_call << 1,
 653     _max_flags = (Flag_is_expensive << 1) - 1 // allow flags combination
 654   };
 655 
 656 private:
 657   jushort _class_id;
 658   jushort _flags;
 659 
 660 protected:
 661   // These methods should be called from constructors only.
 662   void init_class_id(jushort c) {
 663     assert(c <= _max_classes, "invalid node class");
 664     _class_id = c; // cast out const
 665   }
 666   void init_flags(jushort fl) {
 667     assert(fl <= _max_flags, "invalid node flag");
 668     _flags |= fl;
 669   }
 670   void clear_flag(jushort fl) {
 671     assert(fl <= _max_flags, "invalid node flag");
 672     _flags &= ~fl;
 673   }
 674 
 675 public:
 676   const jushort class_id() const { return _class_id; }
 677 
 678   const jushort flags() const { return _flags; }
 679 
 680   // Return a dense integer opcode number
 681   virtual int Opcode() const;
 682 
 683   // Virtual inherited Node size
 684   virtual uint size_of() const;
 685 
 686   // Other interesting Node properties
 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(Call)
 707   DEFINE_CLASS_QUERY(CallDynamicJava)
 708   DEFINE_CLASS_QUERY(CallJava)
 709   DEFINE_CLASS_QUERY(CallLeaf)
 710   DEFINE_CLASS_QUERY(CallRuntime)
 711   DEFINE_CLASS_QUERY(CallStaticJava)
 712   DEFINE_CLASS_QUERY(Catch)
 713   DEFINE_CLASS_QUERY(CatchProj)
 714   DEFINE_CLASS_QUERY(CheckCastPP)
 715   DEFINE_CLASS_QUERY(ConstraintCast)
 716   DEFINE_CLASS_QUERY(ClearArray)
 717   DEFINE_CLASS_QUERY(CMove)
 718   DEFINE_CLASS_QUERY(Cmp)
 719   DEFINE_CLASS_QUERY(CountedLoop)
 720   DEFINE_CLASS_QUERY(CountedLoopEnd)
 721   DEFINE_CLASS_QUERY(DecodeNarrowPtr)
 722   DEFINE_CLASS_QUERY(DecodeN)
 723   DEFINE_CLASS_QUERY(DecodeNKlass)
 724   DEFINE_CLASS_QUERY(EncodeNarrowPtr)
 725   DEFINE_CLASS_QUERY(EncodeP)
 726   DEFINE_CLASS_QUERY(EncodePKlass)
 727   DEFINE_CLASS_QUERY(FastLock)
 728   DEFINE_CLASS_QUERY(FastUnlock)
 729   DEFINE_CLASS_QUERY(If)
 730   DEFINE_CLASS_QUERY(IfFalse)
 731   DEFINE_CLASS_QUERY(IfTrue)
 732   DEFINE_CLASS_QUERY(Initialize)
 733   DEFINE_CLASS_QUERY(Jump)
 734   DEFINE_CLASS_QUERY(JumpProj)
 735   DEFINE_CLASS_QUERY(Load)
 736   DEFINE_CLASS_QUERY(LoadStore)
 737   DEFINE_CLASS_QUERY(Lock)
 738   DEFINE_CLASS_QUERY(Loop)
 739   DEFINE_CLASS_QUERY(Mach)
 740   DEFINE_CLASS_QUERY(MachBranch)
 741   DEFINE_CLASS_QUERY(MachCall)
 742   DEFINE_CLASS_QUERY(MachCallDynamicJava)
 743   DEFINE_CLASS_QUERY(MachCallJava)
 744   DEFINE_CLASS_QUERY(MachCallLeaf)
 745   DEFINE_CLASS_QUERY(MachCallRuntime)
 746   DEFINE_CLASS_QUERY(MachCallStaticJava)
 747   DEFINE_CLASS_QUERY(MachConstantBase)
 748   DEFINE_CLASS_QUERY(MachConstant)
 749   DEFINE_CLASS_QUERY(MachGoto)
 750   DEFINE_CLASS_QUERY(MachIf)
 751   DEFINE_CLASS_QUERY(MachNullCheck)
 752   DEFINE_CLASS_QUERY(MachProj)
 753   DEFINE_CLASS_QUERY(MachReturn)
 754   DEFINE_CLASS_QUERY(MachSafePoint)
 755   DEFINE_CLASS_QUERY(MachSpillCopy)
 756   DEFINE_CLASS_QUERY(MachTemp)
 757   DEFINE_CLASS_QUERY(Mem)
 758   DEFINE_CLASS_QUERY(MemBar)
 759   DEFINE_CLASS_QUERY(MemBarStoreStore)
 760   DEFINE_CLASS_QUERY(MergeMem)
 761   DEFINE_CLASS_QUERY(Mul)
 762   DEFINE_CLASS_QUERY(Multi)
 763   DEFINE_CLASS_QUERY(MultiBranch)
 764   DEFINE_CLASS_QUERY(Parm)
 765   DEFINE_CLASS_QUERY(PCTable)
 766   DEFINE_CLASS_QUERY(Phi)
 767   DEFINE_CLASS_QUERY(Proj)
 768   DEFINE_CLASS_QUERY(Region)
 769   DEFINE_CLASS_QUERY(Root)
 770   DEFINE_CLASS_QUERY(SafePoint)
 771   DEFINE_CLASS_QUERY(SafePointScalarObject)
 772   DEFINE_CLASS_QUERY(Start)
 773   DEFINE_CLASS_QUERY(Store)
 774   DEFINE_CLASS_QUERY(Sub)
 775   DEFINE_CLASS_QUERY(Type)
 776   DEFINE_CLASS_QUERY(Vector)
 777   DEFINE_CLASS_QUERY(LoadVector)
 778   DEFINE_CLASS_QUERY(StoreVector)
 779   DEFINE_CLASS_QUERY(Unlock)
 780 
 781   #undef DEFINE_CLASS_QUERY
 782 
 783   // duplicate of is_MachSpillCopy()
 784   bool is_SpillCopy () const {
 785     return ((_class_id & ClassMask_MachSpillCopy) == Class_MachSpillCopy);
 786   }
 787 
 788   bool is_Con () const { return (_flags & Flag_is_Con) != 0; }
 789   // The data node which is safe to leave in dead loop during IGVN optimization.
 790   bool is_dead_loop_safe() const {
 791     return is_Phi() || (is_Proj() && in(0) == NULL) ||
 792            ((_flags & (Flag_is_dead_loop_safe | Flag_is_Con)) != 0 &&
 793             (!is_Proj() || !in(0)->is_Allocate()));
 794   }
 795 
 796   // is_Copy() returns copied edge index (0 or 1)
 797   uint is_Copy() const { return (_flags & Flag_is_Copy); }
 798 
 799   virtual bool is_CFG() const { return false; }
 800 
 801   // If this node is control-dependent on a test, can it be
 802   // rerouted to a dominating equivalent test?  This is usually
 803   // true of non-CFG nodes, but can be false for operations which
 804   // depend for their correct sequencing on more than one test.
 805   // (In that case, hoisting to a dominating test may silently
 806   // skip some other important test.)
 807   virtual bool depends_only_on_test() const { assert(!is_CFG(), ""); return true; };
 808 
 809   // When building basic blocks, I need to have a notion of block beginning
 810   // Nodes, next block selector Nodes (block enders), and next block
 811   // projections.  These calls need to work on their machine equivalents.  The
 812   // Ideal beginning Nodes are RootNode, RegionNode and StartNode.
 813   bool is_block_start() const {
 814     if ( is_Region() )
 815       return this == (const Node*)in(0);
 816     else
 817       return is_Start();
 818   }
 819 
 820   // The Ideal control projection Nodes are IfTrue/IfFalse, JumpProjNode, Root,
 821   // Goto and Return.  This call also returns the block ending Node.
 822   virtual const Node *is_block_proj() const;
 823 
 824   // The node is a "macro" node which needs to be expanded before matching
 825   bool is_macro() const { return (_flags & Flag_is_macro) != 0; }
 826   // The node is expensive: the best control is set during loop opts
 827   bool is_expensive() const { return (_flags & Flag_is_expensive) != 0 && in(0) != NULL; }
 828 
 829 //----------------- Optimization
 830 
 831   // Get the worst-case Type output for this Node.
 832   virtual const class Type *bottom_type() const;
 833 
 834   // If we find a better type for a node, try to record it permanently.
 835   // Return true if this node actually changed.
 836   // Be sure to do the hash_delete game in the "rehash" variant.
 837   void raise_bottom_type(const Type* new_type);
 838 
 839   // Get the address type with which this node uses and/or defs memory,
 840   // or NULL if none.  The address type is conservatively wide.
 841   // Returns non-null for calls, membars, loads, stores, etc.
 842   // Returns TypePtr::BOTTOM if the node touches memory "broadly".
 843   virtual const class TypePtr *adr_type() const { return NULL; }
 844 
 845   // Return an existing node which computes the same function as this node.
 846   // The optimistic combined algorithm requires this to return a Node which
 847   // is a small number of steps away (e.g., one of my inputs).
 848   virtual Node *Identity( PhaseTransform *phase );
 849 
 850   // Return the set of values this Node can take on at runtime.
 851   virtual const Type *Value( PhaseTransform *phase ) const;
 852 
 853   // Return a node which is more "ideal" than the current node.
 854   // The invariants on this call are subtle.  If in doubt, read the
 855   // treatise in node.cpp above the default implemention AND TEST WITH
 856   // +VerifyIterativeGVN!
 857   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
 858 
 859   // Some nodes have specific Ideal subgraph transformations only if they are
 860   // unique users of specific nodes. Such nodes should be put on IGVN worklist
 861   // for the transformations to happen.
 862   bool has_special_unique_user() const;
 863 
 864   // Skip Proj and CatchProj nodes chains. Check for Null and Top.
 865   Node* find_exact_control(Node* ctrl);
 866 
 867   // Check if 'this' node dominates or equal to 'sub'.
 868   bool dominates(Node* sub, Node_List &nlist);
 869 
 870 protected:
 871   bool remove_dead_region(PhaseGVN *phase, bool can_reshape);
 872 public:
 873 
 874   // Idealize graph, using DU info.  Done after constant propagation
 875   virtual Node *Ideal_DU_postCCP( PhaseCCP *ccp );
 876 
 877   // See if there is valid pipeline info
 878   static  const Pipeline *pipeline_class();
 879   virtual const Pipeline *pipeline() const;
 880 
 881   // Compute the latency from the def to this instruction of the ith input node
 882   uint latency(uint i);
 883 
 884   // Hash & compare functions, for pessimistic value numbering
 885 
 886   // If the hash function returns the special sentinel value NO_HASH,
 887   // the node is guaranteed never to compare equal to any other node.
 888   // If we accidentally generate a hash with value NO_HASH the node
 889   // won't go into the table and we'll lose a little optimization.
 890   enum { NO_HASH = 0 };
 891   virtual uint hash() const;
 892   virtual uint cmp( const Node &n ) const;
 893 
 894   // Operation appears to be iteratively computed (such as an induction variable)
 895   // It is possible for this operation to return false for a loop-varying
 896   // value, if it appears (by local graph inspection) to be computed by a simple conditional.
 897   bool is_iteratively_computed();
 898 
 899   // Determine if a node is Counted loop induction variable.
 900   // The method is defined in loopnode.cpp.
 901   const Node* is_loop_iv() const;
 902 
 903   // Return a node with opcode "opc" and same inputs as "this" if one can
 904   // be found; Otherwise return NULL;
 905   Node* find_similar(int opc);
 906 
 907   // Return the unique control out if only one. Null if none or more than one.
 908   Node* unique_ctrl_out();
 909 
 910 //----------------- Code Generation
 911 
 912   // Ideal register class for Matching.  Zero means unmatched instruction
 913   // (these are cloned instead of converted to machine nodes).
 914   virtual uint ideal_reg() const;
 915 
 916   static const uint NotAMachineReg;   // must be > max. machine register
 917 
 918   // Do we Match on this edge index or not?  Generally false for Control
 919   // and true for everything else.  Weird for calls & returns.
 920   virtual uint match_edge(uint idx) const;
 921 
 922   // Register class output is returned in
 923   virtual const RegMask &out_RegMask() const;
 924   // Register class input is expected in
 925   virtual const RegMask &in_RegMask(uint) const;
 926   // Should we clone rather than spill this instruction?
 927   bool rematerialize() const;
 928 
 929   // Return JVM State Object if this Node carries debug info, or NULL otherwise
 930   virtual JVMState* jvms() const;
 931 
 932   // Print as assembly
 933   virtual void format( PhaseRegAlloc *, outputStream* st = tty ) const;
 934   // Emit bytes starting at parameter 'ptr'
 935   // Bump 'ptr' by the number of output bytes
 936   virtual void emit(CodeBuffer &cbuf, PhaseRegAlloc *ra_) const;
 937   // Size of instruction in bytes
 938   virtual uint size(PhaseRegAlloc *ra_) const;
 939 
 940   // Convenience function to extract an integer constant from a node.
 941   // If it is not an integer constant (either Con, CastII, or Mach),
 942   // return value_if_unknown.
 943   jint find_int_con(jint value_if_unknown) const {
 944     const TypeInt* t = find_int_type();
 945     return (t != NULL && t->is_con()) ? t->get_con() : value_if_unknown;
 946   }
 947   // Return the constant, knowing it is an integer constant already
 948   jint get_int() const {
 949     const TypeInt* t = find_int_type();
 950     guarantee(t != NULL, "must be con");
 951     return t->get_con();
 952   }
 953   // Here's where the work is done.  Can produce non-constant int types too.
 954   const TypeInt* find_int_type() const;
 955 
 956   // Same thing for long (and intptr_t, via type.hpp):
 957   jlong get_long() const {
 958     const TypeLong* t = find_long_type();
 959     guarantee(t != NULL, "must be con");
 960     return t->get_con();
 961   }
 962   jlong find_long_con(jint value_if_unknown) const {
 963     const TypeLong* t = find_long_type();
 964     return (t != NULL && t->is_con()) ? t->get_con() : value_if_unknown;
 965   }
 966   const TypeLong* find_long_type() const;
 967 
 968   const TypePtr* get_ptr_type() const;
 969 
 970   // These guys are called by code generated by ADLC:
 971   intptr_t get_ptr() const;
 972   intptr_t get_narrowcon() const;
 973   jdouble getd() const;
 974   jfloat getf() const;
 975 
 976   // Nodes which are pinned into basic blocks
 977   virtual bool pinned() const { return false; }
 978 
 979   // Nodes which use memory without consuming it, hence need antidependences
 980   // More specifically, needs_anti_dependence_check returns true iff the node
 981   // (a) does a load, and (b) does not perform a store (except perhaps to a
 982   // stack slot or some other unaliased location).
 983   bool needs_anti_dependence_check() const;
 984 
 985   // Return which operand this instruction may cisc-spill. In other words,
 986   // return operand position that can convert from reg to memory access
 987   virtual int cisc_operand() const { return AdlcVMDeps::Not_cisc_spillable; }
 988   bool is_cisc_alternate() const { return (_flags & Flag_is_cisc_alternate) != 0; }
 989 
 990 //----------------- Graph walking
 991 public:
 992   // Walk and apply member functions recursively.
 993   // Supplied (this) pointer is root.
 994   void walk(NFunc pre, NFunc post, void *env);
 995   static void nop(Node &, void*); // Dummy empty function
 996   static void packregion( Node &n, void* );
 997 private:
 998   void walk_(NFunc pre, NFunc post, void *env, VectorSet &visited);
 999 
1000 //----------------- Printing, etc
1001 public:
1002 #ifndef PRODUCT
1003   Node* find(int idx) const;         // Search the graph for the given idx.
1004   Node* find_ctrl(int idx) const;    // Search control ancestors for the given idx.
1005   void dump() const { dump("\n"); }  // Print this node.
1006   void dump(const char* suffix, outputStream *st = tty) const;// Print this node.
1007   void dump(int depth) const;        // Print this node, recursively to depth d
1008   void dump_ctrl(int depth) const;   // Print control nodes, to depth d
1009   virtual void dump_req(outputStream *st = tty) const;     // Print required-edge info
1010   virtual void dump_prec(outputStream *st = tty) const;    // Print precedence-edge info
1011   virtual void dump_out(outputStream *st = tty) const;     // Print the output edge info
1012   virtual void dump_spec(outputStream *st) const {}; // Print per-node info
1013   void verify_edges(Unique_Node_List &visited); // Verify bi-directional edges
1014   void verify() const;               // Check Def-Use info for my subgraph
1015   static void verify_recur(const Node *n, int verify_depth, VectorSet &old_space, VectorSet &new_space);
1016 
1017   // This call defines a class-unique string used to identify class instances
1018   virtual const char *Name() const;
1019 
1020   void dump_format(PhaseRegAlloc *ra) const; // debug access to MachNode::format(...)
1021   // RegMask Print Functions
1022   void dump_in_regmask(int idx) { in_RegMask(idx).dump(); }
1023   void dump_out_regmask() { out_RegMask().dump(); }
1024   static int _in_dump_cnt;
1025   static bool in_dump() { return _in_dump_cnt > 0; }
1026   void fast_dump() const {
1027     tty->print("%4d: %-17s", _idx, Name());
1028     for (uint i = 0; i < len(); i++)
1029       if (in(i))
1030         tty->print(" %4d", in(i)->_idx);
1031       else
1032         tty->print(" NULL");
1033     tty->print("\n");
1034   }
1035 #endif
1036 #ifdef ASSERT
1037   void verify_construction();
1038   bool verify_jvms(const JVMState* jvms) const;
1039   int  _debug_idx;                     // Unique value assigned to every node.
1040   int   debug_idx() const              { return _debug_idx; }
1041   void  set_debug_idx( int debug_idx ) { _debug_idx = debug_idx; }
1042 
1043   Node* _debug_orig;                   // Original version of this, if any.
1044   Node*  debug_orig() const            { return _debug_orig; }
1045   void   set_debug_orig(Node* orig);   // _debug_orig = orig
1046 
1047   int        _hash_lock;               // Barrier to modifications of nodes in the hash table
1048   void  enter_hash_lock() { ++_hash_lock; assert(_hash_lock < 99, "in too many hash tables?"); }
1049   void   exit_hash_lock() { --_hash_lock; assert(_hash_lock >= 0, "mispaired hash locks"); }
1050 
1051   static void init_NodeProperty();
1052 
1053   #if OPTO_DU_ITERATOR_ASSERT
1054   const Node* _last_del;               // The last deleted node.
1055   uint        _del_tick;               // Bumped when a deletion happens..
1056   #endif
1057 #endif
1058 };
1059 
1060 //-----------------------------------------------------------------------------
1061 // Iterators over DU info, and associated Node functions.
1062 
1063 #if OPTO_DU_ITERATOR_ASSERT
1064 
1065 // Common code for assertion checking on DU iterators.
1066 class DUIterator_Common VALUE_OBJ_CLASS_SPEC {
1067 #ifdef ASSERT
1068  protected:
1069   bool         _vdui;               // cached value of VerifyDUIterators
1070   const Node*  _node;               // the node containing the _out array
1071   uint         _outcnt;             // cached node->_outcnt
1072   uint         _del_tick;           // cached node->_del_tick
1073   Node*        _last;               // last value produced by the iterator
1074 
1075   void sample(const Node* node);    // used by c'tor to set up for verifies
1076   void verify(const Node* node, bool at_end_ok = false);
1077   void verify_resync();
1078   void reset(const DUIterator_Common& that);
1079 
1080 // The VDUI_ONLY macro protects code conditionalized on VerifyDUIterators
1081   #define I_VDUI_ONLY(i,x) { if ((i)._vdui) { x; } }
1082 #else
1083   #define I_VDUI_ONLY(i,x) { }
1084 #endif //ASSERT
1085 };
1086 
1087 #define VDUI_ONLY(x)     I_VDUI_ONLY(*this, x)
1088 
1089 // Default DU iterator.  Allows appends onto the out array.
1090 // Allows deletion from the out array only at the current point.
1091 // Usage:
1092 //  for (DUIterator i = x->outs(); x->has_out(i); i++) {
1093 //    Node* y = x->out(i);
1094 //    ...
1095 //  }
1096 // Compiles in product mode to a unsigned integer index, which indexes
1097 // onto a repeatedly reloaded base pointer of x->_out.  The loop predicate
1098 // also reloads x->_outcnt.  If you delete, you must perform "--i" just
1099 // before continuing the loop.  You must delete only the last-produced
1100 // edge.  You must delete only a single copy of the last-produced edge,
1101 // or else you must delete all copies at once (the first time the edge
1102 // is produced by the iterator).
1103 class DUIterator : public DUIterator_Common {
1104   friend class Node;
1105 
1106   // This is the index which provides the product-mode behavior.
1107   // Whatever the product-mode version of the system does to the
1108   // DUI index is done to this index.  All other fields in
1109   // this class are used only for assertion checking.
1110   uint         _idx;
1111 
1112   #ifdef ASSERT
1113   uint         _refresh_tick;    // Records the refresh activity.
1114 
1115   void sample(const Node* node); // Initialize _refresh_tick etc.
1116   void verify(const Node* node, bool at_end_ok = false);
1117   void verify_increment();       // Verify an increment operation.
1118   void verify_resync();          // Verify that we can back up over a deletion.
1119   void verify_finish();          // Verify that the loop terminated properly.
1120   void refresh();                // Resample verification info.
1121   void reset(const DUIterator& that);  // Resample after assignment.
1122   #endif
1123 
1124   DUIterator(const Node* node, int dummy_to_avoid_conversion)
1125     { _idx = 0;                         debug_only(sample(node)); }
1126 
1127  public:
1128   // initialize to garbage; clear _vdui to disable asserts
1129   DUIterator()
1130     { /*initialize to garbage*/         debug_only(_vdui = false); }
1131 
1132   void operator++(int dummy_to_specify_postfix_op)
1133     { _idx++;                           VDUI_ONLY(verify_increment()); }
1134 
1135   void operator--()
1136     { VDUI_ONLY(verify_resync());       --_idx; }
1137 
1138   ~DUIterator()
1139     { VDUI_ONLY(verify_finish()); }
1140 
1141   void operator=(const DUIterator& that)
1142     { _idx = that._idx;                 debug_only(reset(that)); }
1143 };
1144 
1145 DUIterator Node::outs() const
1146   { return DUIterator(this, 0); }
1147 DUIterator& Node::refresh_out_pos(DUIterator& i) const
1148   { I_VDUI_ONLY(i, i.refresh());        return i; }
1149 bool Node::has_out(DUIterator& i) const
1150   { I_VDUI_ONLY(i, i.verify(this,true));return i._idx < _outcnt; }
1151 Node*    Node::out(DUIterator& i) const
1152   { I_VDUI_ONLY(i, i.verify(this));     return debug_only(i._last=) _out[i._idx]; }
1153 
1154 
1155 // Faster DU iterator.  Disallows insertions into the out array.
1156 // Allows deletion from the out array only at the current point.
1157 // Usage:
1158 //  for (DUIterator_Fast imax, i = x->fast_outs(imax); i < imax; i++) {
1159 //    Node* y = x->fast_out(i);
1160 //    ...
1161 //  }
1162 // Compiles in product mode to raw Node** pointer arithmetic, with
1163 // no reloading of pointers from the original node x.  If you delete,
1164 // you must perform "--i; --imax" just before continuing the loop.
1165 // If you delete multiple copies of the same edge, you must decrement
1166 // imax, but not i, multiple times:  "--i, imax -= num_edges".
1167 class DUIterator_Fast : public DUIterator_Common {
1168   friend class Node;
1169   friend class DUIterator_Last;
1170 
1171   // This is the pointer which provides the product-mode behavior.
1172   // Whatever the product-mode version of the system does to the
1173   // DUI pointer is done to this pointer.  All other fields in
1174   // this class are used only for assertion checking.
1175   Node**       _outp;
1176 
1177   #ifdef ASSERT
1178   void verify(const Node* node, bool at_end_ok = false);
1179   void verify_limit();
1180   void verify_resync();
1181   void verify_relimit(uint n);
1182   void reset(const DUIterator_Fast& that);
1183   #endif
1184 
1185   // Note:  offset must be signed, since -1 is sometimes passed
1186   DUIterator_Fast(const Node* node, ptrdiff_t offset)
1187     { _outp = node->_out + offset;      debug_only(sample(node)); }
1188 
1189  public:
1190   // initialize to garbage; clear _vdui to disable asserts
1191   DUIterator_Fast()
1192     { /*initialize to garbage*/         debug_only(_vdui = false); }
1193 
1194   void operator++(int dummy_to_specify_postfix_op)
1195     { _outp++;                          VDUI_ONLY(verify(_node, true)); }
1196 
1197   void operator--()
1198     { VDUI_ONLY(verify_resync());       --_outp; }
1199 
1200   void operator-=(uint n)   // applied to the limit only
1201     { _outp -= n;           VDUI_ONLY(verify_relimit(n));  }
1202 
1203   bool operator<(DUIterator_Fast& limit) {
1204     I_VDUI_ONLY(*this, this->verify(_node, true));
1205     I_VDUI_ONLY(limit, limit.verify_limit());
1206     return _outp < limit._outp;
1207   }
1208 
1209   void operator=(const DUIterator_Fast& that)
1210     { _outp = that._outp;               debug_only(reset(that)); }
1211 };
1212 
1213 DUIterator_Fast Node::fast_outs(DUIterator_Fast& imax) const {
1214   // Assign a limit pointer to the reference argument:
1215   imax = DUIterator_Fast(this, (ptrdiff_t)_outcnt);
1216   // Return the base pointer:
1217   return DUIterator_Fast(this, 0);
1218 }
1219 Node* Node::fast_out(DUIterator_Fast& i) const {
1220   I_VDUI_ONLY(i, i.verify(this));
1221   return debug_only(i._last=) *i._outp;
1222 }
1223 
1224 
1225 // Faster DU iterator.  Requires each successive edge to be removed.
1226 // Does not allow insertion of any edges.
1227 // Usage:
1228 //  for (DUIterator_Last imin, i = x->last_outs(imin); i >= imin; i -= num_edges) {
1229 //    Node* y = x->last_out(i);
1230 //    ...
1231 //  }
1232 // Compiles in product mode to raw Node** pointer arithmetic, with
1233 // no reloading of pointers from the original node x.
1234 class DUIterator_Last : private DUIterator_Fast {
1235   friend class Node;
1236 
1237   #ifdef ASSERT
1238   void verify(const Node* node, bool at_end_ok = false);
1239   void verify_limit();
1240   void verify_step(uint num_edges);
1241   #endif
1242 
1243   // Note:  offset must be signed, since -1 is sometimes passed
1244   DUIterator_Last(const Node* node, ptrdiff_t offset)
1245     : DUIterator_Fast(node, offset) { }
1246 
1247   void operator++(int dummy_to_specify_postfix_op) {} // do not use
1248   void operator<(int)                              {} // do not use
1249 
1250  public:
1251   DUIterator_Last() { }
1252   // initialize to garbage
1253 
1254   void operator--()
1255     { _outp--;              VDUI_ONLY(verify_step(1));  }
1256 
1257   void operator-=(uint n)
1258     { _outp -= n;           VDUI_ONLY(verify_step(n));  }
1259 
1260   bool operator>=(DUIterator_Last& limit) {
1261     I_VDUI_ONLY(*this, this->verify(_node, true));
1262     I_VDUI_ONLY(limit, limit.verify_limit());
1263     return _outp >= limit._outp;
1264   }
1265 
1266   void operator=(const DUIterator_Last& that)
1267     { DUIterator_Fast::operator=(that); }
1268 };
1269 
1270 DUIterator_Last Node::last_outs(DUIterator_Last& imin) const {
1271   // Assign a limit pointer to the reference argument:
1272   imin = DUIterator_Last(this, 0);
1273   // Return the initial pointer:
1274   return DUIterator_Last(this, (ptrdiff_t)_outcnt - 1);
1275 }
1276 Node* Node::last_out(DUIterator_Last& i) const {
1277   I_VDUI_ONLY(i, i.verify(this));
1278   return debug_only(i._last=) *i._outp;
1279 }
1280 
1281 #endif //OPTO_DU_ITERATOR_ASSERT
1282 
1283 #undef I_VDUI_ONLY
1284 #undef VDUI_ONLY
1285 
1286 // An Iterator that truly follows the iterator pattern.  Doesn't
1287 // support deletion but could be made to.
1288 //
1289 //   for (SimpleDUIterator i(n); i.has_next(); i.next()) {
1290 //     Node* m = i.get();
1291 //
1292 class SimpleDUIterator : public StackObj {
1293  private:
1294   Node* node;
1295   DUIterator_Fast i;
1296   DUIterator_Fast imax;
1297  public:
1298   SimpleDUIterator(Node* n): node(n), i(n->fast_outs(imax)) {}
1299   bool has_next() { return i < imax; }
1300   void next() { i++; }
1301   Node* get() { return node->fast_out(i); }
1302 };
1303 
1304 
1305 //-----------------------------------------------------------------------------
1306 // Map dense integer indices to Nodes.  Uses classic doubling-array trick.
1307 // Abstractly provides an infinite array of Node*'s, initialized to NULL.
1308 // Note that the constructor just zeros things, and since I use Arena
1309 // allocation I do not need a destructor to reclaim storage.
1310 class Node_Array : public ResourceObj {
1311   friend class VMStructs;
1312 protected:
1313   Arena *_a;                    // Arena to allocate in
1314   uint   _max;
1315   Node **_nodes;
1316   void   grow( uint i );        // Grow array node to fit
1317 public:
1318   Node_Array(Arena *a) : _a(a), _max(OptoNodeListSize) {
1319     _nodes = NEW_ARENA_ARRAY( a, Node *, OptoNodeListSize );
1320     for( int i = 0; i < OptoNodeListSize; i++ ) {
1321       _nodes[i] = NULL;
1322     }
1323   }
1324 
1325   Node_Array(Node_Array *na) : _a(na->_a), _max(na->_max), _nodes(na->_nodes) {}
1326   Node *operator[] ( uint i ) const // Lookup, or NULL for not mapped
1327   { return (i<_max) ? _nodes[i] : (Node*)NULL; }
1328   Node *at( uint i ) const { assert(i<_max,"oob"); return _nodes[i]; }
1329   Node **adr() { return _nodes; }
1330   // Extend the mapping: index i maps to Node *n.
1331   void map( uint i, Node *n ) { if( i>=_max ) grow(i); _nodes[i] = n; }
1332   void insert( uint i, Node *n );
1333   void remove( uint i );        // Remove, preserving order
1334   void sort( C_sort_func_t func);
1335   void reset( Arena *new_a );   // Zap mapping to empty; reclaim storage
1336   void clear();                 // Set all entries to NULL, keep storage
1337   uint Size() const { return _max; }
1338   void dump() const;
1339 };
1340 
1341 class Node_List : public Node_Array {
1342   friend class VMStructs;
1343   uint _cnt;
1344 public:
1345   Node_List() : Node_Array(Thread::current()->resource_area()), _cnt(0) {}
1346   Node_List(Arena *a) : Node_Array(a), _cnt(0) {}
1347   bool contains(Node* n) {
1348     for (uint e = 0; e < size(); e++) {
1349       if (at(e) == n) return true;
1350     }
1351     return false;
1352   }
1353   void insert( uint i, Node *n ) { Node_Array::insert(i,n); _cnt++; }
1354   void remove( uint i ) { Node_Array::remove(i); _cnt--; }
1355   void push( Node *b ) { map(_cnt++,b); }
1356   void yank( Node *n );         // Find and remove
1357   Node *pop() { return _nodes[--_cnt]; }
1358   Node *rpop() { Node *b = _nodes[0]; _nodes[0]=_nodes[--_cnt]; return b;}
1359   void clear() { _cnt = 0; Node_Array::clear(); } // retain storage
1360   uint size() const { return _cnt; }
1361   void dump() const;
1362 };
1363 
1364 //------------------------------Unique_Node_List-------------------------------
1365 class Unique_Node_List : public Node_List {
1366   friend class VMStructs;
1367   VectorSet _in_worklist;
1368   uint _clock_index;            // Index in list where to pop from next
1369 public:
1370   Unique_Node_List() : Node_List(), _in_worklist(Thread::current()->resource_area()), _clock_index(0) {}
1371   Unique_Node_List(Arena *a) : Node_List(a), _in_worklist(a), _clock_index(0) {}
1372 
1373   void remove( Node *n );
1374   bool member( Node *n ) { return _in_worklist.test(n->_idx) != 0; }
1375   VectorSet &member_set(){ return _in_worklist; }
1376 
1377   void push( Node *b ) {
1378     if( !_in_worklist.test_set(b->_idx) )
1379       Node_List::push(b);
1380   }
1381   Node *pop() {
1382     if( _clock_index >= size() ) _clock_index = 0;
1383     Node *b = at(_clock_index);
1384     map( _clock_index, Node_List::pop());
1385     if (size() != 0) _clock_index++; // Always start from 0
1386     _in_worklist >>= b->_idx;
1387     return b;
1388   }
1389   Node *remove( uint i ) {
1390     Node *b = Node_List::at(i);
1391     _in_worklist >>= b->_idx;
1392     map(i,Node_List::pop());
1393     return b;
1394   }
1395   void yank( Node *n ) { _in_worklist >>= n->_idx; Node_List::yank(n); }
1396   void  clear() {
1397     _in_worklist.Clear();        // Discards storage but grows automatically
1398     Node_List::clear();
1399     _clock_index = 0;
1400   }
1401 
1402   // Used after parsing to remove useless nodes before Iterative GVN
1403   void remove_useless_nodes(VectorSet &useful);
1404 
1405 #ifndef PRODUCT
1406   void print_set() const { _in_worklist.print(); }
1407 #endif
1408 };
1409 
1410 // Inline definition of Compile::record_for_igvn must be deferred to this point.
1411 inline void Compile::record_for_igvn(Node* n) {
1412   _for_igvn->push(n);
1413 }
1414 
1415 //------------------------------Node_Stack-------------------------------------
1416 class Node_Stack {
1417   friend class VMStructs;
1418 protected:
1419   struct INode {
1420     Node *node; // Processed node
1421     uint  indx; // Index of next node's child
1422   };
1423   INode *_inode_top; // tos, stack grows up
1424   INode *_inode_max; // End of _inodes == _inodes + _max
1425   INode *_inodes;    // Array storage for the stack
1426   Arena *_a;         // Arena to allocate in
1427   void grow();
1428 public:
1429   Node_Stack(int size) {
1430     size_t max = (size > OptoNodeListSize) ? size : OptoNodeListSize;
1431     _a = Thread::current()->resource_area();
1432     _inodes = NEW_ARENA_ARRAY( _a, INode, max );
1433     _inode_max = _inodes + max;
1434     _inode_top = _inodes - 1; // stack is empty
1435   }
1436 
1437   Node_Stack(Arena *a, int size) : _a(a) {
1438     size_t max = (size > OptoNodeListSize) ? size : OptoNodeListSize;
1439     _inodes = NEW_ARENA_ARRAY( _a, INode, max );
1440     _inode_max = _inodes + max;
1441     _inode_top = _inodes - 1; // stack is empty
1442   }
1443 
1444   void pop() {
1445     assert(_inode_top >= _inodes, "node stack underflow");
1446     --_inode_top;
1447   }
1448   void push(Node *n, uint i) {
1449     ++_inode_top;
1450     if (_inode_top >= _inode_max) grow();
1451     INode *top = _inode_top; // optimization
1452     top->node = n;
1453     top->indx = i;
1454   }
1455   Node *node() const {
1456     return _inode_top->node;
1457   }
1458   Node* node_at(uint i) const {
1459     assert(_inodes + i <= _inode_top, "in range");
1460     return _inodes[i].node;
1461   }
1462   uint index() const {
1463     return _inode_top->indx;
1464   }
1465   uint index_at(uint i) const {
1466     assert(_inodes + i <= _inode_top, "in range");
1467     return _inodes[i].indx;
1468   }
1469   void set_node(Node *n) {
1470     _inode_top->node = n;
1471   }
1472   void set_index(uint i) {
1473     _inode_top->indx = i;
1474   }
1475   uint size_max() const { return (uint)pointer_delta(_inode_max, _inodes,  sizeof(INode)); } // Max size
1476   uint size() const { return (uint)pointer_delta((_inode_top+1), _inodes,  sizeof(INode)); } // Current size
1477   bool is_nonempty() const { return (_inode_top >= _inodes); }
1478   bool is_empty() const { return (_inode_top < _inodes); }
1479   void clear() { _inode_top = _inodes - 1; } // retain storage
1480 
1481   // Node_Stack is used to map nodes.
1482   Node* find(uint idx) const;
1483 };
1484 
1485 
1486 //-----------------------------Node_Notes--------------------------------------
1487 // Debugging or profiling annotations loosely and sparsely associated
1488 // with some nodes.  See Compile::node_notes_at for the accessor.
1489 class Node_Notes VALUE_OBJ_CLASS_SPEC {
1490   friend class VMStructs;
1491   JVMState* _jvms;
1492 
1493 public:
1494   Node_Notes(JVMState* jvms = NULL) {
1495     _jvms = jvms;
1496   }
1497 
1498   JVMState* jvms()            { return _jvms; }
1499   void  set_jvms(JVMState* x) {        _jvms = x; }
1500 
1501   // True if there is nothing here.
1502   bool is_clear() {
1503     return (_jvms == NULL);
1504   }
1505 
1506   // Make there be nothing here.
1507   void clear() {
1508     _jvms = NULL;
1509   }
1510 
1511   // Make a new, clean node notes.
1512   static Node_Notes* make(Compile* C) {
1513     Node_Notes* nn = NEW_ARENA_ARRAY(C->comp_arena(), Node_Notes, 1);
1514     nn->clear();
1515     return nn;
1516   }
1517 
1518   Node_Notes* clone(Compile* C) {
1519     Node_Notes* nn = NEW_ARENA_ARRAY(C->comp_arena(), Node_Notes, 1);
1520     (*nn) = (*this);
1521     return nn;
1522   }
1523 
1524   // Absorb any information from source.
1525   bool update_from(Node_Notes* source) {
1526     bool changed = false;
1527     if (source != NULL) {
1528       if (source->jvms() != NULL) {
1529         set_jvms(source->jvms());
1530         changed = true;
1531       }
1532     }
1533     return changed;
1534   }
1535 };
1536 
1537 // Inlined accessors for Compile::node_nodes that require the preceding class:
1538 inline Node_Notes*
1539 Compile::locate_node_notes(GrowableArray<Node_Notes*>* arr,
1540                            int idx, bool can_grow) {
1541   assert(idx >= 0, "oob");
1542   int block_idx = (idx >> _log2_node_notes_block_size);
1543   int grow_by = (block_idx - (arr == NULL? 0: arr->length()));
1544   if (grow_by >= 0) {
1545     if (!can_grow)  return NULL;
1546     grow_node_notes(arr, grow_by + 1);
1547   }
1548   // (Every element of arr is a sub-array of length _node_notes_block_size.)
1549   return arr->at(block_idx) + (idx & (_node_notes_block_size-1));
1550 }
1551 
1552 inline bool
1553 Compile::set_node_notes_at(int idx, Node_Notes* value) {
1554   if (value == NULL || value->is_clear())
1555     return false;  // nothing to write => write nothing
1556   Node_Notes* loc = locate_node_notes(_node_note_array, idx, true);
1557   assert(loc != NULL, "");
1558   return loc->update_from(value);
1559 }
1560 
1561 
1562 //------------------------------TypeNode---------------------------------------
1563 // Node with a Type constant.
1564 class TypeNode : public Node {
1565 protected:
1566   virtual uint hash() const;    // Check the type
1567   virtual uint cmp( const Node &n ) const;
1568   virtual uint size_of() const; // Size is bigger
1569   const Type* const _type;
1570 public:
1571   void set_type(const Type* t) {
1572     assert(t != NULL, "sanity");
1573     debug_only(uint check_hash = (VerifyHashTableKeys && _hash_lock) ? hash() : NO_HASH);
1574     *(const Type**)&_type = t;   // cast away const-ness
1575     // If this node is in the hash table, make sure it doesn't need a rehash.
1576     assert(check_hash == NO_HASH || check_hash == hash(), "type change must preserve hash code");
1577   }
1578   const Type* type() const { assert(_type != NULL, "sanity"); return _type; };
1579   TypeNode( const Type *t, uint required ) : Node(required), _type(t) {
1580     init_class_id(Class_Type);
1581   }
1582   virtual const Type *Value( PhaseTransform *phase ) const;
1583   virtual const Type *bottom_type() const;
1584   virtual       uint  ideal_reg() const;
1585 #ifndef PRODUCT
1586   virtual void dump_spec(outputStream *st) const;
1587 #endif
1588 };
1589 
1590 #endif // SHARE_VM_OPTO_NODE_HPP