hotspot/src/share/vm/opto/node.hpp
changeset 1 489c9b5090e2
child 206 d61cf247afd5
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/opto/node.hpp	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,1492 @@
+/*
+ * Copyright 1997-2007 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+// Portions of code courtesy of Clifford Click
+
+// Optimization - Graph Style
+
+
+class AbstractLockNode;
+class AddNode;
+class AddPNode;
+class AliasInfo;
+class AllocateArrayNode;
+class AllocateNode;
+class Block;
+class Block_Array;
+class BoolNode;
+class BoxLockNode;
+class CMoveNode;
+class CallDynamicJavaNode;
+class CallJavaNode;
+class CallLeafNode;
+class CallNode;
+class CallRuntimeNode;
+class CallStaticJavaNode;
+class CatchNode;
+class CatchProjNode;
+class CheckCastPPNode;
+class CmpNode;
+class CodeBuffer;
+class ConstraintCastNode;
+class ConNode;
+class CountedLoopNode;
+class CountedLoopEndNode;
+class FastLockNode;
+class FastUnlockNode;
+class IfNode;
+class InitializeNode;
+class JVMState;
+class JumpNode;
+class JumpProjNode;
+class LoadNode;
+class LoadStoreNode;
+class LockNode;
+class LoopNode;
+class MachCallDynamicJavaNode;
+class MachCallJavaNode;
+class MachCallLeafNode;
+class MachCallNode;
+class MachCallRuntimeNode;
+class MachCallStaticJavaNode;
+class MachIfNode;
+class MachNode;
+class MachNullCheckNode;
+class MachReturnNode;
+class MachSafePointNode;
+class MachSpillCopyNode;
+class MachTempNode;
+class Matcher;
+class MemBarNode;
+class MemNode;
+class MergeMemNode;
+class MulNode;
+class MultiNode;
+class MultiBranchNode;
+class NeverBranchNode;
+class Node;
+class Node_Array;
+class Node_List;
+class Node_Stack;
+class NullCheckNode;
+class OopMap;
+class PCTableNode;
+class PhaseCCP;
+class PhaseGVN;
+class PhaseIterGVN;
+class PhaseRegAlloc;
+class PhaseTransform;
+class PhaseValues;
+class PhiNode;
+class Pipeline;
+class ProjNode;
+class RegMask;
+class RegionNode;
+class RootNode;
+class SafePointNode;
+class StartNode;
+class State;
+class StoreNode;
+class SubNode;
+class Type;
+class TypeNode;
+class UnlockNode;
+class VectorSet;
+class IfTrueNode;
+class IfFalseNode;
+typedef void (*NFunc)(Node&,void*);
+extern "C" {
+  typedef int (*C_sort_func_t)(const void *, const void *);
+}
+
+// The type of all node counts and indexes.
+// It must hold at least 16 bits, but must also be fast to load and store.
+// This type, if less than 32 bits, could limit the number of possible nodes.
+// (To make this type platform-specific, move to globalDefinitions_xxx.hpp.)
+typedef unsigned int node_idx_t;
+
+
+#ifndef OPTO_DU_ITERATOR_ASSERT
+#ifdef ASSERT
+#define OPTO_DU_ITERATOR_ASSERT 1
+#else
+#define OPTO_DU_ITERATOR_ASSERT 0
+#endif
+#endif //OPTO_DU_ITERATOR_ASSERT
+
+#if OPTO_DU_ITERATOR_ASSERT
+class DUIterator;
+class DUIterator_Fast;
+class DUIterator_Last;
+#else
+typedef uint   DUIterator;
+typedef Node** DUIterator_Fast;
+typedef Node** DUIterator_Last;
+#endif
+
+// Node Sentinel
+#define NodeSentinel (Node*)-1
+
+// Unknown count frequency
+#define COUNT_UNKNOWN (-1.0f)
+
+//------------------------------Node-------------------------------------------
+// Nodes define actions in the program.  They create values, which have types.
+// They are both vertices in a directed graph and program primitives.  Nodes
+// are labeled; the label is the "opcode", the primitive function in the lambda
+// calculus sense that gives meaning to the Node.  Node inputs are ordered (so
+// that "a-b" is different from "b-a").  The inputs to a Node are the inputs to
+// the Node's function.  These inputs also define a Type equation for the Node.
+// Solving these Type equations amounts to doing dataflow analysis.
+// Control and data are uniformly represented in the graph.  Finally, Nodes
+// have a unique dense integer index which is used to index into side arrays
+// whenever I have phase-specific information.
+
+class Node {
+  // Lots of restrictions on cloning Nodes
+  Node(const Node&);            // not defined; linker error to use these
+  Node &operator=(const Node &rhs);
+
+public:
+  friend class Compile;
+  #if OPTO_DU_ITERATOR_ASSERT
+  friend class DUIterator_Common;
+  friend class DUIterator;
+  friend class DUIterator_Fast;
+  friend class DUIterator_Last;
+  #endif
+
+  // Because Nodes come and go, I define an Arena of Node structures to pull
+  // from.  This should allow fast access to node creation & deletion.  This
+  // field is a local cache of a value defined in some "program fragment" for
+  // which these Nodes are just a part of.
+
+  // New Operator that takes a Compile pointer, this will eventually
+  // be the "new" New operator.
+  inline void* operator new( size_t x, Compile* C) {
+    Node* n = (Node*)C->node_arena()->Amalloc_D(x);
+#ifdef ASSERT
+    n->_in = (Node**)n; // magic cookie for assertion check
+#endif
+    n->_out = (Node**)C;
+    return (void*)n;
+  }
+
+  // New Operator that takes a Compile pointer, this will eventually
+  // be the "new" New operator.
+  inline void* operator new( size_t x, Compile* C, int y) {
+    Node* n = (Node*)C->node_arena()->Amalloc_D(x + y*sizeof(void*));
+    n->_in = (Node**)(((char*)n) + x);
+#ifdef ASSERT
+    n->_in[y-1] = n; // magic cookie for assertion check
+#endif
+    n->_out = (Node**)C;
+    return (void*)n;
+  }
+
+  // Delete is a NOP
+  void operator delete( void *ptr ) {}
+  // Fancy destructor; eagerly attempt to reclaim Node numberings and storage
+  void destruct();
+
+  // Create a new Node.  Required is the number is of inputs required for
+  // semantic correctness.
+  Node( uint required );
+
+  // Create a new Node with given input edges.
+  // This version requires use of the "edge-count" new.
+  // E.g.  new (C,3) FooNode( C, NULL, left, right );
+  Node( Node *n0 );
+  Node( Node *n0, Node *n1 );
+  Node( Node *n0, Node *n1, Node *n2 );
+  Node( Node *n0, Node *n1, Node *n2, Node *n3 );
+  Node( Node *n0, Node *n1, Node *n2, Node *n3, Node *n4 );
+  Node( Node *n0, Node *n1, Node *n2, Node *n3, Node *n4, Node *n5 );
+  Node( Node *n0, Node *n1, Node *n2, Node *n3,
+            Node *n4, Node *n5, Node *n6 );
+
+  // Clone an inherited Node given only the base Node type.
+  Node* clone() const;
+
+  // Clone a Node, immediately supplying one or two new edges.
+  // The first and second arguments, if non-null, replace in(1) and in(2),
+  // respectively.
+  Node* clone_with_data_edge(Node* in1, Node* in2 = NULL) const {
+    Node* nn = clone();
+    if (in1 != NULL)  nn->set_req(1, in1);
+    if (in2 != NULL)  nn->set_req(2, in2);
+    return nn;
+  }
+
+private:
+  // Shared setup for the above constructors.
+  // Handles all interactions with Compile::current.
+  // Puts initial values in all Node fields except _idx.
+  // Returns the initial value for _idx, which cannot
+  // be initialized by assignment.
+  inline int Init(int req, Compile* C);
+
+//----------------- input edge handling
+protected:
+  friend class PhaseCFG;        // Access to address of _in array elements
+  Node **_in;                   // Array of use-def references to Nodes
+  Node **_out;                  // Array of def-use references to Nodes
+
+  // Input edges are split into two catagories.  Required edges are required
+  // for semantic correctness; order is important and NULLs are allowed.
+  // Precedence edges are used to help determine execution order and are
+  // added, e.g., for scheduling purposes.  They are unordered and not
+  // duplicated; they have no embedded NULLs.  Edges from 0 to _cnt-1
+  // are required, from _cnt to _max-1 are precedence edges.
+  node_idx_t _cnt;              // Total number of required Node inputs.
+
+  node_idx_t _max;              // Actual length of input array.
+
+  // Output edges are an unordered list of def-use edges which exactly
+  // correspond to required input edges which point from other nodes
+  // to this one.  Thus the count of the output edges is the number of
+  // users of this node.
+  node_idx_t _outcnt;           // Total number of Node outputs.
+
+  node_idx_t _outmax;           // Actual length of output array.
+
+  // Grow the actual input array to the next larger power-of-2 bigger than len.
+  void grow( uint len );
+  // Grow the output array to the next larger power-of-2 bigger than len.
+  void out_grow( uint len );
+
+ public:
+  // Each Node is assigned a unique small/dense number.  This number is used
+  // to index into auxiliary arrays of data and bitvectors.
+  // It is declared const to defend against inadvertant assignment,
+  // since it is used by clients as a naked field.
+  const node_idx_t _idx;
+
+  // Get the (read-only) number of input edges
+  uint req() const { return _cnt; }
+  uint len() const { return _max; }
+  // Get the (read-only) number of output edges
+  uint outcnt() const { return _outcnt; }
+
+#if OPTO_DU_ITERATOR_ASSERT
+  // Iterate over the out-edges of this node.  Deletions are illegal.
+  inline DUIterator outs() const;
+  // Use this when the out array might have changed to suppress asserts.
+  inline DUIterator& refresh_out_pos(DUIterator& i) const;
+  // Does the node have an out at this position?  (Used for iteration.)
+  inline bool has_out(DUIterator& i) const;
+  inline Node*    out(DUIterator& i) const;
+  // Iterate over the out-edges of this node.  All changes are illegal.
+  inline DUIterator_Fast fast_outs(DUIterator_Fast& max) const;
+  inline Node*    fast_out(DUIterator_Fast& i) const;
+  // Iterate over the out-edges of this node, deleting one at a time.
+  inline DUIterator_Last last_outs(DUIterator_Last& min) const;
+  inline Node*    last_out(DUIterator_Last& i) const;
+  // The inline bodies of all these methods are after the iterator definitions.
+#else
+  // Iterate over the out-edges of this node.  Deletions are illegal.
+  // This iteration uses integral indexes, to decouple from array reallocations.
+  DUIterator outs() const  { return 0; }
+  // Use this when the out array might have changed to suppress asserts.
+  DUIterator refresh_out_pos(DUIterator i) const { return i; }
+
+  // Reference to the i'th output Node.  Error if out of bounds.
+  Node*    out(DUIterator i) const { assert(i < _outcnt, "oob"); return _out[i]; }
+  // Does the node have an out at this position?  (Used for iteration.)
+  bool has_out(DUIterator i) const { return i < _outcnt; }
+
+  // Iterate over the out-edges of this node.  All changes are illegal.
+  // This iteration uses a pointer internal to the out array.
+  DUIterator_Fast fast_outs(DUIterator_Fast& max) const {
+    Node** out = _out;
+    // Assign a limit pointer to the reference argument:
+    max = out + (ptrdiff_t)_outcnt;
+    // Return the base pointer:
+    return out;
+  }
+  Node*    fast_out(DUIterator_Fast i) const  { return *i; }
+  // Iterate over the out-edges of this node, deleting one at a time.
+  // This iteration uses a pointer internal to the out array.
+  DUIterator_Last last_outs(DUIterator_Last& min) const {
+    Node** out = _out;
+    // Assign a limit pointer to the reference argument:
+    min = out;
+    // Return the pointer to the start of the iteration:
+    return out + (ptrdiff_t)_outcnt - 1;
+  }
+  Node*    last_out(DUIterator_Last i) const  { return *i; }
+#endif
+
+  // Reference to the i'th input Node.  Error if out of bounds.
+  Node* in(uint i) const { assert(i < _max,"oob"); return _in[i]; }
+  // Reference to the i'th output Node.  Error if out of bounds.
+  // Use this accessor sparingly.  We are going trying to use iterators instead.
+  Node* raw_out(uint i) const { assert(i < _outcnt,"oob"); return _out[i]; }
+  // Return the unique out edge.
+  Node* unique_out() const { assert(_outcnt==1,"not unique"); return _out[0]; }
+  // Delete out edge at position 'i' by moving last out edge to position 'i'
+  void  raw_del_out(uint i) {
+    assert(i < _outcnt,"oob");
+    assert(_outcnt > 0,"oob");
+    #if OPTO_DU_ITERATOR_ASSERT
+    // Record that a change happened here.
+    debug_only(_last_del = _out[i]; ++_del_tick);
+    #endif
+    _out[i] = _out[--_outcnt];
+    // Smash the old edge so it can't be used accidentally.
+    debug_only(_out[_outcnt] = (Node *)(uintptr_t)0xdeadbeef);
+  }
+
+#ifdef ASSERT
+  bool is_dead() const;
+#define is_not_dead(n) ((n) == NULL || !VerifyIterativeGVN || !((n)->is_dead()))
+#endif
+
+  // Set a required input edge, also updates corresponding output edge
+  void add_req( Node *n ); // Append a NEW required input
+  void add_req_batch( Node* n, uint m ); // Append m NEW required inputs (all n).
+  void del_req( uint idx ); // Delete required edge & compact
+  void ins_req( uint i, Node *n ); // Insert a NEW required input
+  void set_req( uint i, Node *n ) {
+    assert( is_not_dead(n), "can not use dead node");
+    assert( i < _cnt, "oob");
+    assert( !VerifyHashTableKeys || _hash_lock == 0,
+            "remove node from hash table before modifying it");
+    Node** p = &_in[i];    // cache this._in, across the del_out call
+    if (*p != NULL)  (*p)->del_out((Node *)this);
+    (*p) = n;
+    if (n != NULL)      n->add_out((Node *)this);
+  }
+  // Light version of set_req() to init inputs after node creation.
+  void init_req( uint i, Node *n ) {
+    assert( i == 0 && this == n ||
+            is_not_dead(n), "can not use dead node");
+    assert( i < _cnt, "oob");
+    assert( !VerifyHashTableKeys || _hash_lock == 0,
+            "remove node from hash table before modifying it");
+    assert( _in[i] == NULL, "sanity");
+    _in[i] = n;
+    if (n != NULL)      n->add_out((Node *)this);
+  }
+  // Find first occurrence of n among my edges:
+  int find_edge(Node* n);
+  int replace_edge(Node* old, Node* neww);
+  // NULL out all inputs to eliminate incoming Def-Use edges.
+  // Return the number of edges between 'n' and 'this'
+  int  disconnect_inputs(Node *n);
+
+  // Quickly, return true if and only if I am Compile::current()->top().
+  bool is_top() const {
+    assert((this == (Node*) Compile::current()->top()) == (_out == NULL), "");
+    return (_out == NULL);
+  }
+  // Reaffirm invariants for is_top.  (Only from Compile::set_cached_top_node.)
+  void setup_is_top();
+
+  // Strip away casting.  (It is depth-limited.)
+  Node* uncast() const;
+
+private:
+  static Node* uncast_helper(const Node* n);
+
+  // Add an output edge to the end of the list
+  void add_out( Node *n ) {
+    if (is_top())  return;
+    if( _outcnt == _outmax ) out_grow(_outcnt);
+    _out[_outcnt++] = n;
+  }
+  // Delete an output edge
+  void del_out( Node *n ) {
+    if (is_top())  return;
+    Node** outp = &_out[_outcnt];
+    // Find and remove n
+    do {
+      assert(outp > _out, "Missing Def-Use edge");
+    } while (*--outp != n);
+    *outp = _out[--_outcnt];
+    // Smash the old edge so it can't be used accidentally.
+    debug_only(_out[_outcnt] = (Node *)(uintptr_t)0xdeadbeef);
+    // Record that a change happened here.
+    #if OPTO_DU_ITERATOR_ASSERT
+    debug_only(_last_del = n; ++_del_tick);
+    #endif
+  }
+
+public:
+  // Globally replace this node by a given new node, updating all uses.
+  void replace_by(Node* new_node);
+  void set_req_X( uint i, Node *n, PhaseIterGVN *igvn );
+  // Find the one non-null required input.  RegionNode only
+  Node *nonnull_req() const;
+  // Add or remove precedence edges
+  void add_prec( Node *n );
+  void rm_prec( uint i );
+  void set_prec( uint i, Node *n ) {
+    assert( is_not_dead(n), "can not use dead node");
+    assert( i >= _cnt, "not a precedence edge");
+    if (_in[i] != NULL) _in[i]->del_out((Node *)this);
+    _in[i] = n;
+    if (n != NULL) n->add_out((Node *)this);
+  }
+  // Set this node's index, used by cisc_version to replace current node
+  void set_idx(uint new_idx) {
+    const node_idx_t* ref = &_idx;
+    *(node_idx_t*)ref = new_idx;
+  }
+  // Swap input edge order.  (Edge indexes i1 and i2 are usually 1 and 2.)
+  void swap_edges(uint i1, uint i2) {
+    debug_only(uint check_hash = (VerifyHashTableKeys && _hash_lock) ? hash() : NO_HASH);
+    // Def-Use info is unchanged
+    Node* n1 = in(i1);
+    Node* n2 = in(i2);
+    _in[i1] = n2;
+    _in[i2] = n1;
+    // If this node is in the hash table, make sure it doesn't need a rehash.
+    assert(check_hash == NO_HASH || check_hash == hash(), "edge swap must preserve hash code");
+  }
+
+  // Iterators over input Nodes for a Node X are written as:
+  // for( i = 0; i < X.req(); i++ ) ... X[i] ...
+  // NOTE: Required edges can contain embedded NULL pointers.
+
+//----------------- Other Node Properties
+
+  // Generate class id for some ideal nodes to avoid virtual query
+  // methods is_<Node>().
+  // Class id is the set of bits corresponded to the node class and all its
+  // super classes so that queries for super classes are also valid.
+  // Subclasses of the same super class have different assigned bit
+  // (the third parameter in the macro DEFINE_CLASS_ID).
+  // Classes with deeper hierarchy are declared first.
+  // Classes with the same hierarchy depth are sorted by usage frequency.
+  //
+  // The query method masks the bits to cut off bits of subclasses
+  // and then compare the result with the class id
+  // (see the macro DEFINE_CLASS_QUERY below).
+  //
+  //  Class_MachCall=30, ClassMask_MachCall=31
+  // 12               8               4               0
+  //  0   0   0   0   0   0   0   0   1   1   1   1   0
+  //                                  |   |   |   |
+  //                                  |   |   |   Bit_Mach=2
+  //                                  |   |   Bit_MachReturn=4
+  //                                  |   Bit_MachSafePoint=8
+  //                                  Bit_MachCall=16
+  //
+  //  Class_CountedLoop=56, ClassMask_CountedLoop=63
+  // 12               8               4               0
+  //  0   0   0   0   0   0   0   1   1   1   0   0   0
+  //                              |   |   |
+  //                              |   |   Bit_Region=8
+  //                              |   Bit_Loop=16
+  //                              Bit_CountedLoop=32
+
+  #define DEFINE_CLASS_ID(cl, supcl, subn) \
+  Bit_##cl = (Class_##supcl == 0) ? 1 << subn : (Bit_##supcl) << (1 + subn) , \
+  Class_##cl = Class_##supcl + Bit_##cl , \
+  ClassMask_##cl = ((Bit_##cl << 1) - 1) ,
+
+  // This enum is used only for C2 ideal and mach nodes with is_<node>() methods
+  // so that it's values fits into 16 bits.
+  enum NodeClasses {
+    Bit_Node   = 0x0000,
+    Class_Node = 0x0000,
+    ClassMask_Node = 0xFFFF,
+
+    DEFINE_CLASS_ID(Multi, Node, 0)
+      DEFINE_CLASS_ID(SafePoint, Multi, 0)
+        DEFINE_CLASS_ID(Call,      SafePoint, 0)
+          DEFINE_CLASS_ID(CallJava,         Call, 0)
+            DEFINE_CLASS_ID(CallStaticJava,   CallJava, 0)
+            DEFINE_CLASS_ID(CallDynamicJava,  CallJava, 1)
+          DEFINE_CLASS_ID(CallRuntime,      Call, 1)
+            DEFINE_CLASS_ID(CallLeaf,         CallRuntime, 0)
+          DEFINE_CLASS_ID(Allocate,         Call, 2)
+            DEFINE_CLASS_ID(AllocateArray,    Allocate, 0)
+          DEFINE_CLASS_ID(AbstractLock,     Call, 3)
+            DEFINE_CLASS_ID(Lock,             AbstractLock, 0)
+            DEFINE_CLASS_ID(Unlock,           AbstractLock, 1)
+      DEFINE_CLASS_ID(MultiBranch, Multi, 1)
+        DEFINE_CLASS_ID(PCTable,     MultiBranch, 0)
+          DEFINE_CLASS_ID(Catch,       PCTable, 0)
+          DEFINE_CLASS_ID(Jump,        PCTable, 1)
+        DEFINE_CLASS_ID(If,          MultiBranch, 1)
+          DEFINE_CLASS_ID(CountedLoopEnd, If, 0)
+        DEFINE_CLASS_ID(NeverBranch, MultiBranch, 2)
+      DEFINE_CLASS_ID(Start,       Multi, 2)
+      DEFINE_CLASS_ID(MemBar,      Multi, 3)
+        DEFINE_CLASS_ID(Initialize,    MemBar, 0)
+
+    DEFINE_CLASS_ID(Mach,  Node, 1)
+      DEFINE_CLASS_ID(MachReturn, Mach, 0)
+        DEFINE_CLASS_ID(MachSafePoint, MachReturn, 0)
+          DEFINE_CLASS_ID(MachCall, MachSafePoint, 0)
+            DEFINE_CLASS_ID(MachCallJava,         MachCall, 0)
+              DEFINE_CLASS_ID(MachCallStaticJava,   MachCallJava, 0)
+              DEFINE_CLASS_ID(MachCallDynamicJava,  MachCallJava, 1)
+            DEFINE_CLASS_ID(MachCallRuntime,      MachCall, 1)
+              DEFINE_CLASS_ID(MachCallLeaf,         MachCallRuntime, 0)
+      DEFINE_CLASS_ID(MachSpillCopy, Mach, 1)
+      DEFINE_CLASS_ID(MachNullCheck, Mach, 2)
+      DEFINE_CLASS_ID(MachIf,        Mach, 3)
+      DEFINE_CLASS_ID(MachTemp,      Mach, 4)
+
+    DEFINE_CLASS_ID(Proj,  Node, 2)
+      DEFINE_CLASS_ID(CatchProj, Proj, 0)
+      DEFINE_CLASS_ID(JumpProj,  Proj, 1)
+      DEFINE_CLASS_ID(IfTrue,    Proj, 2)
+      DEFINE_CLASS_ID(IfFalse,   Proj, 3)
+
+    DEFINE_CLASS_ID(Region, Node, 3)
+      DEFINE_CLASS_ID(Loop, Region, 0)
+        DEFINE_CLASS_ID(Root,        Loop, 0)
+        DEFINE_CLASS_ID(CountedLoop, Loop, 1)
+
+    DEFINE_CLASS_ID(Sub,   Node, 4)
+      DEFINE_CLASS_ID(Cmp,   Sub, 0)
+        DEFINE_CLASS_ID(FastLock,   Cmp, 0)
+        DEFINE_CLASS_ID(FastUnlock, Cmp, 1)
+
+    DEFINE_CLASS_ID(Type,  Node, 5)
+      DEFINE_CLASS_ID(Phi,   Type, 0)
+      DEFINE_CLASS_ID(ConstraintCast, Type, 1)
+      DEFINE_CLASS_ID(CheckCastPP, Type, 2)
+      DEFINE_CLASS_ID(CMove, Type, 3)
+
+    DEFINE_CLASS_ID(Mem,   Node, 6)
+      DEFINE_CLASS_ID(Load,  Mem, 0)
+      DEFINE_CLASS_ID(Store, Mem, 1)
+      DEFINE_CLASS_ID(LoadStore, Mem, 2)
+
+    DEFINE_CLASS_ID(MergeMem, Node, 7)
+    DEFINE_CLASS_ID(Bool,     Node, 8)
+    DEFINE_CLASS_ID(AddP,     Node, 9)
+    DEFINE_CLASS_ID(BoxLock,  Node, 10)
+    DEFINE_CLASS_ID(Add,      Node, 11)
+    DEFINE_CLASS_ID(Mul,      Node, 12)
+
+    _max_classes  = ClassMask_Mul
+  };
+  #undef DEFINE_CLASS_ID
+
+  // Flags are sorted by usage frequency.
+  enum NodeFlags {
+    Flag_is_Copy             = 0x01, // should be first bit to avoid shift
+    Flag_is_Call             = Flag_is_Copy << 1,
+    Flag_rematerialize       = Flag_is_Call << 1,
+    Flag_needs_anti_dependence_check = Flag_rematerialize << 1,
+    Flag_is_macro            = Flag_needs_anti_dependence_check << 1,
+    Flag_is_Con              = Flag_is_macro << 1,
+    Flag_is_cisc_alternate   = Flag_is_Con << 1,
+    Flag_is_Branch           = Flag_is_cisc_alternate << 1,
+    Flag_is_block_start      = Flag_is_Branch << 1,
+    Flag_is_Goto             = Flag_is_block_start << 1,
+    Flag_is_dead_loop_safe   = Flag_is_Goto << 1,
+    Flag_may_be_short_branch = Flag_is_dead_loop_safe << 1,
+    Flag_is_safepoint_node   = Flag_may_be_short_branch << 1,
+    Flag_is_pc_relative      = Flag_is_safepoint_node << 1,
+    Flag_is_Vector           = Flag_is_pc_relative << 1,
+    _max_flags = (Flag_is_Vector << 1) - 1 // allow flags combination
+  };
+
+private:
+  jushort _class_id;
+  jushort _flags;
+
+protected:
+  // These methods should be called from constructors only.
+  void init_class_id(jushort c) {
+    assert(c <= _max_classes, "invalid node class");
+    _class_id = c; // cast out const
+  }
+  void init_flags(jushort fl) {
+    assert(fl <= _max_flags, "invalid node flag");
+    _flags |= fl;
+  }
+  void clear_flag(jushort fl) {
+    assert(fl <= _max_flags, "invalid node flag");
+    _flags &= ~fl;
+  }
+
+public:
+  const jushort class_id() const { return _class_id; }
+
+  const jushort flags() const { return _flags; }
+
+  // Return a dense integer opcode number
+  virtual int Opcode() const;
+
+  // Virtual inherited Node size
+  virtual uint size_of() const;
+
+  // Other interesting Node properties
+
+  // Special case: is_Call() returns true for both CallNode and MachCallNode.
+  bool is_Call() const {
+    return (_flags & Flag_is_Call) != 0;
+  }
+
+  CallNode *as_Call() const { // Only for CallNode (not for MachCallNode)
+    assert((_class_id & ClassMask_Call) == Class_Call, "invalid node class");
+    return (CallNode*)this;
+  }
+
+  #define DEFINE_CLASS_QUERY(type) \
+  bool is_##type() const { \
+    return ((_class_id & ClassMask_##type) == Class_##type); \
+  } \
+  type##Node *as_##type() const { \
+    assert(is_##type(), "invalid node class"); \
+    return (type##Node*)this; \
+  }
+
+  DEFINE_CLASS_QUERY(AbstractLock)
+  DEFINE_CLASS_QUERY(Add)
+  DEFINE_CLASS_QUERY(AddP)
+  DEFINE_CLASS_QUERY(Allocate)
+  DEFINE_CLASS_QUERY(AllocateArray)
+  DEFINE_CLASS_QUERY(Bool)
+  DEFINE_CLASS_QUERY(BoxLock)
+  DEFINE_CLASS_QUERY(CallDynamicJava)
+  DEFINE_CLASS_QUERY(CallJava)
+  DEFINE_CLASS_QUERY(CallLeaf)
+  DEFINE_CLASS_QUERY(CallRuntime)
+  DEFINE_CLASS_QUERY(CallStaticJava)
+  DEFINE_CLASS_QUERY(Catch)
+  DEFINE_CLASS_QUERY(CatchProj)
+  DEFINE_CLASS_QUERY(CheckCastPP)
+  DEFINE_CLASS_QUERY(ConstraintCast)
+  DEFINE_CLASS_QUERY(CMove)
+  DEFINE_CLASS_QUERY(Cmp)
+  DEFINE_CLASS_QUERY(CountedLoop)
+  DEFINE_CLASS_QUERY(CountedLoopEnd)
+  DEFINE_CLASS_QUERY(FastLock)
+  DEFINE_CLASS_QUERY(FastUnlock)
+  DEFINE_CLASS_QUERY(If)
+  DEFINE_CLASS_QUERY(IfFalse)
+  DEFINE_CLASS_QUERY(IfTrue)
+  DEFINE_CLASS_QUERY(Initialize)
+  DEFINE_CLASS_QUERY(Jump)
+  DEFINE_CLASS_QUERY(JumpProj)
+  DEFINE_CLASS_QUERY(Load)
+  DEFINE_CLASS_QUERY(LoadStore)
+  DEFINE_CLASS_QUERY(Lock)
+  DEFINE_CLASS_QUERY(Loop)
+  DEFINE_CLASS_QUERY(Mach)
+  DEFINE_CLASS_QUERY(MachCall)
+  DEFINE_CLASS_QUERY(MachCallDynamicJava)
+  DEFINE_CLASS_QUERY(MachCallJava)
+  DEFINE_CLASS_QUERY(MachCallLeaf)
+  DEFINE_CLASS_QUERY(MachCallRuntime)
+  DEFINE_CLASS_QUERY(MachCallStaticJava)
+  DEFINE_CLASS_QUERY(MachIf)
+  DEFINE_CLASS_QUERY(MachNullCheck)
+  DEFINE_CLASS_QUERY(MachReturn)
+  DEFINE_CLASS_QUERY(MachSafePoint)
+  DEFINE_CLASS_QUERY(MachSpillCopy)
+  DEFINE_CLASS_QUERY(MachTemp)
+  DEFINE_CLASS_QUERY(Mem)
+  DEFINE_CLASS_QUERY(MemBar)
+  DEFINE_CLASS_QUERY(MergeMem)
+  DEFINE_CLASS_QUERY(Mul)
+  DEFINE_CLASS_QUERY(Multi)
+  DEFINE_CLASS_QUERY(MultiBranch)
+  DEFINE_CLASS_QUERY(PCTable)
+  DEFINE_CLASS_QUERY(Phi)
+  DEFINE_CLASS_QUERY(Proj)
+  DEFINE_CLASS_QUERY(Region)
+  DEFINE_CLASS_QUERY(Root)
+  DEFINE_CLASS_QUERY(SafePoint)
+  DEFINE_CLASS_QUERY(Start)
+  DEFINE_CLASS_QUERY(Store)
+  DEFINE_CLASS_QUERY(Sub)
+  DEFINE_CLASS_QUERY(Type)
+  DEFINE_CLASS_QUERY(Unlock)
+
+  #undef DEFINE_CLASS_QUERY
+
+  // duplicate of is_MachSpillCopy()
+  bool is_SpillCopy () const {
+    return ((_class_id & ClassMask_MachSpillCopy) == Class_MachSpillCopy);
+  }
+
+  bool is_Con () const { return (_flags & Flag_is_Con) != 0; }
+  bool is_Goto() const { return (_flags & Flag_is_Goto) != 0; }
+  // The data node which is safe to leave in dead loop during IGVN optimization.
+  bool is_dead_loop_safe() const {
+    return is_Phi() || is_Proj() ||
+           (_flags & (Flag_is_dead_loop_safe | Flag_is_Con)) != 0;
+  }
+
+  // is_Copy() returns copied edge index (0 or 1)
+  uint is_Copy() const { return (_flags & Flag_is_Copy); }
+
+  virtual bool is_CFG() const { return false; }
+
+  // If this node is control-dependent on a test, can it be
+  // rerouted to a dominating equivalent test?  This is usually
+  // true of non-CFG nodes, but can be false for operations which
+  // depend for their correct sequencing on more than one test.
+  // (In that case, hoisting to a dominating test may silently
+  // skip some other important test.)
+  virtual bool depends_only_on_test() const { assert(!is_CFG(), ""); return true; };
+
+  // defined for MachNodes that match 'If' | 'Goto' | 'CountedLoopEnd'
+  bool is_Branch() const { return (_flags & Flag_is_Branch) != 0; }
+
+  // When building basic blocks, I need to have a notion of block beginning
+  // Nodes, next block selector Nodes (block enders), and next block
+  // projections.  These calls need to work on their machine equivalents.  The
+  // Ideal beginning Nodes are RootNode, RegionNode and StartNode.
+  bool is_block_start() const {
+    if ( is_Region() )
+      return this == (const Node*)in(0);
+    else
+      return (_flags & Flag_is_block_start) != 0;
+  }
+
+  // The Ideal control projection Nodes are IfTrue/IfFalse, JumpProjNode, Root,
+  // Goto and Return.  This call also returns the block ending Node.
+  virtual const Node *is_block_proj() const;
+
+  // The node is a "macro" node which needs to be expanded before matching
+  bool is_macro() const { return (_flags & Flag_is_macro) != 0; }
+
+  // Value is a vector of primitive values
+  bool is_Vector() const { return (_flags & Flag_is_Vector) != 0; }
+
+//----------------- Optimization
+
+  // Get the worst-case Type output for this Node.
+  virtual const class Type *bottom_type() const;
+
+  // If we find a better type for a node, try to record it permanently.
+  // Return true if this node actually changed.
+  // Be sure to do the hash_delete game in the "rehash" variant.
+  void raise_bottom_type(const Type* new_type);
+
+  // Get the address type with which this node uses and/or defs memory,
+  // or NULL if none.  The address type is conservatively wide.
+  // Returns non-null for calls, membars, loads, stores, etc.
+  // Returns TypePtr::BOTTOM if the node touches memory "broadly".
+  virtual const class TypePtr *adr_type() const { return NULL; }
+
+  // Return an existing node which computes the same function as this node.
+  // The optimistic combined algorithm requires this to return a Node which
+  // is a small number of steps away (e.g., one of my inputs).
+  virtual Node *Identity( PhaseTransform *phase );
+
+  // Return the set of values this Node can take on at runtime.
+  virtual const Type *Value( PhaseTransform *phase ) const;
+
+  // Return a node which is more "ideal" than the current node.
+  // The invariants on this call are subtle.  If in doubt, read the
+  // treatise in node.cpp above the default implemention AND TEST WITH
+  // +VerifyIterativeGVN!
+  virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
+
+  // Some nodes have specific Ideal subgraph transformations only if they are
+  // unique users of specific nodes. Such nodes should be put on IGVN worklist
+  // for the transformations to happen.
+  bool has_special_unique_user() const;
+
+protected:
+  bool remove_dead_region(PhaseGVN *phase, bool can_reshape);
+public:
+
+  // Idealize graph, using DU info.  Done after constant propagation
+  virtual Node *Ideal_DU_postCCP( PhaseCCP *ccp );
+
+  // See if there is valid pipeline info
+  static  const Pipeline *pipeline_class();
+  virtual const Pipeline *pipeline() const;
+
+  // Compute the latency from the def to this instruction of the ith input node
+  uint latency(uint i);
+
+  // Hash & compare functions, for pessimistic value numbering
+
+  // If the hash function returns the special sentinel value NO_HASH,
+  // the node is guaranteed never to compare equal to any other node.
+  // If we accidently generate a hash with value NO_HASH the node
+  // won't go into the table and we'll lose a little optimization.
+  enum { NO_HASH = 0 };
+  virtual uint hash() const;
+  virtual uint cmp( const Node &n ) const;
+
+  // Operation appears to be iteratively computed (such as an induction variable)
+  // It is possible for this operation to return false for a loop-varying
+  // value, if it appears (by local graph inspection) to be computed by a simple conditional.
+  bool is_iteratively_computed();
+
+  // Determine if a node is Counted loop induction variable.
+  // The method is defined in loopnode.cpp.
+  const Node* is_loop_iv() const;
+
+  // Return a node with opcode "opc" and same inputs as "this" if one can
+  // be found; Otherwise return NULL;
+  Node* find_similar(int opc);
+
+  // Return the unique control out if only one. Null if none or more than one.
+  Node* unique_ctrl_out();
+
+//----------------- Code Generation
+
+  // Ideal register class for Matching.  Zero means unmatched instruction
+  // (these are cloned instead of converted to machine nodes).
+  virtual uint ideal_reg() const;
+
+  static const uint NotAMachineReg;   // must be > max. machine register
+
+  // Do we Match on this edge index or not?  Generally false for Control
+  // and true for everything else.  Weird for calls & returns.
+  virtual uint match_edge(uint idx) const;
+
+  // Register class output is returned in
+  virtual const RegMask &out_RegMask() const;
+  // Register class input is expected in
+  virtual const RegMask &in_RegMask(uint) const;
+  // Should we clone rather than spill this instruction?
+  bool rematerialize() const;
+
+  // Return JVM State Object if this Node carries debug info, or NULL otherwise
+  virtual JVMState* jvms() const;
+
+  // Print as assembly
+  virtual void format( PhaseRegAlloc *, outputStream* st = tty ) const;
+  // Emit bytes starting at parameter 'ptr'
+  // Bump 'ptr' by the number of output bytes
+  virtual void emit(CodeBuffer &cbuf, PhaseRegAlloc *ra_) const;
+  // Size of instruction in bytes
+  virtual uint size(PhaseRegAlloc *ra_) const;
+
+  // Convenience function to extract an integer constant from a node.
+  // If it is not an integer constant (either Con, CastII, or Mach),
+  // return value_if_unknown.
+  jint find_int_con(jint value_if_unknown) const {
+    const TypeInt* t = find_int_type();
+    return (t != NULL && t->is_con()) ? t->get_con() : value_if_unknown;
+  }
+  // Return the constant, knowing it is an integer constant already
+  jint get_int() const {
+    const TypeInt* t = find_int_type();
+    guarantee(t != NULL, "must be con");
+    return t->get_con();
+  }
+  // Here's where the work is done.  Can produce non-constant int types too.
+  const TypeInt* find_int_type() const;
+
+  // Same thing for long (and intptr_t, via type.hpp):
+  jlong get_long() const {
+    const TypeLong* t = find_long_type();
+    guarantee(t != NULL, "must be con");
+    return t->get_con();
+  }
+  jlong find_long_con(jint value_if_unknown) const {
+    const TypeLong* t = find_long_type();
+    return (t != NULL && t->is_con()) ? t->get_con() : value_if_unknown;
+  }
+  const TypeLong* find_long_type() const;
+
+  // These guys are called by code generated by ADLC:
+  intptr_t get_ptr() const;
+  jdouble getd() const;
+  jfloat getf() const;
+
+  // Nodes which are pinned into basic blocks
+  virtual bool pinned() const { return false; }
+
+  // Nodes which use memory without consuming it, hence need antidependences
+  // More specifically, needs_anti_dependence_check returns true iff the node
+  // (a) does a load, and (b) does not perform a store (except perhaps to a
+  // stack slot or some other unaliased location).
+  bool needs_anti_dependence_check() const;
+
+  // Return which operand this instruction may cisc-spill. In other words,
+  // return operand position that can convert from reg to memory access
+  virtual int cisc_operand() const { return AdlcVMDeps::Not_cisc_spillable; }
+  bool is_cisc_alternate() const { return (_flags & Flag_is_cisc_alternate) != 0; }
+
+//----------------- Graph walking
+public:
+  // Walk and apply member functions recursively.
+  // Supplied (this) pointer is root.
+  void walk(NFunc pre, NFunc post, void *env);
+  static void nop(Node &, void*); // Dummy empty function
+  static void packregion( Node &n, void* );
+private:
+  void walk_(NFunc pre, NFunc post, void *env, VectorSet &visited);
+
+//----------------- Printing, etc
+public:
+#ifndef PRODUCT
+  Node* find(int idx) const;         // Search the graph for the given idx.
+  Node* find_ctrl(int idx) const;    // Search control ancestors for the given idx.
+  void dump() const;                 // Print this node,
+  void dump(int depth) const;        // Print this node, recursively to depth d
+  void dump_ctrl(int depth) const;   // Print control nodes, to depth d
+  virtual void dump_req() const;     // Print required-edge info
+  virtual void dump_prec() const;    // Print precedence-edge info
+  virtual void dump_out() const;     // Print the output edge info
+  virtual void dump_spec(outputStream *st) const {}; // Print per-node info
+  void verify_edges(Unique_Node_List &visited); // Verify bi-directional edges
+  void verify() const;               // Check Def-Use info for my subgraph
+  static void verify_recur(const Node *n, int verify_depth, VectorSet &old_space, VectorSet &new_space);
+
+  // This call defines a class-unique string used to identify class instances
+  virtual const char *Name() const;
+
+  void dump_format(PhaseRegAlloc *ra) const; // debug access to MachNode::format(...)
+  // RegMask Print Functions
+  void dump_in_regmask(int idx) { in_RegMask(idx).dump(); }
+  void dump_out_regmask() { out_RegMask().dump(); }
+  static int _in_dump_cnt;
+  static bool in_dump() { return _in_dump_cnt > 0; }
+  void fast_dump() const {
+    tty->print("%4d: %-17s", _idx, Name());
+    for (uint i = 0; i < len(); i++)
+      if (in(i))
+        tty->print(" %4d", in(i)->_idx);
+      else
+        tty->print(" NULL");
+    tty->print("\n");
+  }
+#endif
+#ifdef ASSERT
+  void verify_construction();
+  bool verify_jvms(const JVMState* jvms) const;
+  int  _debug_idx;                     // Unique value assigned to every node.
+  int   debug_idx() const              { return _debug_idx; }
+  void  set_debug_idx( int debug_idx ) { _debug_idx = debug_idx; }
+
+  Node* _debug_orig;                   // Original version of this, if any.
+  Node*  debug_orig() const            { return _debug_orig; }
+  void   set_debug_orig(Node* orig);   // _debug_orig = orig
+
+  int        _hash_lock;               // Barrier to modifications of nodes in the hash table
+  void  enter_hash_lock() { ++_hash_lock; assert(_hash_lock < 99, "in too many hash tables?"); }
+  void   exit_hash_lock() { --_hash_lock; assert(_hash_lock >= 0, "mispaired hash locks"); }
+
+  static void init_NodeProperty();
+
+  #if OPTO_DU_ITERATOR_ASSERT
+  const Node* _last_del;               // The last deleted node.
+  uint        _del_tick;               // Bumped when a deletion happens..
+  #endif
+#endif
+};
+
+//-----------------------------------------------------------------------------
+// Iterators over DU info, and associated Node functions.
+
+#if OPTO_DU_ITERATOR_ASSERT
+
+// Common code for assertion checking on DU iterators.
+class DUIterator_Common VALUE_OBJ_CLASS_SPEC {
+#ifdef ASSERT
+ protected:
+  bool         _vdui;               // cached value of VerifyDUIterators
+  const Node*  _node;               // the node containing the _out array
+  uint         _outcnt;             // cached node->_outcnt
+  uint         _del_tick;           // cached node->_del_tick
+  Node*        _last;               // last value produced by the iterator
+
+  void sample(const Node* node);    // used by c'tor to set up for verifies
+  void verify(const Node* node, bool at_end_ok = false);
+  void verify_resync();
+  void reset(const DUIterator_Common& that);
+
+// The VDUI_ONLY macro protects code conditionalized on VerifyDUIterators
+  #define I_VDUI_ONLY(i,x) { if ((i)._vdui) { x; } }
+#else
+  #define I_VDUI_ONLY(i,x) { }
+#endif //ASSERT
+};
+
+#define VDUI_ONLY(x)     I_VDUI_ONLY(*this, x)
+
+// Default DU iterator.  Allows appends onto the out array.
+// Allows deletion from the out array only at the current point.
+// Usage:
+//  for (DUIterator i = x->outs(); x->has_out(i); i++) {
+//    Node* y = x->out(i);
+//    ...
+//  }
+// Compiles in product mode to a unsigned integer index, which indexes
+// onto a repeatedly reloaded base pointer of x->_out.  The loop predicate
+// also reloads x->_outcnt.  If you delete, you must perform "--i" just
+// before continuing the loop.  You must delete only the last-produced
+// edge.  You must delete only a single copy of the last-produced edge,
+// or else you must delete all copies at once (the first time the edge
+// is produced by the iterator).
+class DUIterator : public DUIterator_Common {
+  friend class Node;
+
+  // This is the index which provides the product-mode behavior.
+  // Whatever the product-mode version of the system does to the
+  // DUI index is done to this index.  All other fields in
+  // this class are used only for assertion checking.
+  uint         _idx;
+
+  #ifdef ASSERT
+  uint         _refresh_tick;    // Records the refresh activity.
+
+  void sample(const Node* node); // Initialize _refresh_tick etc.
+  void verify(const Node* node, bool at_end_ok = false);
+  void verify_increment();       // Verify an increment operation.
+  void verify_resync();          // Verify that we can back up over a deletion.
+  void verify_finish();          // Verify that the loop terminated properly.
+  void refresh();                // Resample verification info.
+  void reset(const DUIterator& that);  // Resample after assignment.
+  #endif
+
+  DUIterator(const Node* node, int dummy_to_avoid_conversion)
+    { _idx = 0;                         debug_only(sample(node)); }
+
+ public:
+  // initialize to garbage; clear _vdui to disable asserts
+  DUIterator()
+    { /*initialize to garbage*/         debug_only(_vdui = false); }
+
+  void operator++(int dummy_to_specify_postfix_op)
+    { _idx++;                           VDUI_ONLY(verify_increment()); }
+
+  void operator--()
+    { VDUI_ONLY(verify_resync());       --_idx; }
+
+  ~DUIterator()
+    { VDUI_ONLY(verify_finish()); }
+
+  void operator=(const DUIterator& that)
+    { _idx = that._idx;                 debug_only(reset(that)); }
+};
+
+DUIterator Node::outs() const
+  { return DUIterator(this, 0); }
+DUIterator& Node::refresh_out_pos(DUIterator& i) const
+  { I_VDUI_ONLY(i, i.refresh());        return i; }
+bool Node::has_out(DUIterator& i) const
+  { I_VDUI_ONLY(i, i.verify(this,true));return i._idx < _outcnt; }
+Node*    Node::out(DUIterator& i) const
+  { I_VDUI_ONLY(i, i.verify(this));     return debug_only(i._last=) _out[i._idx]; }
+
+
+// Faster DU iterator.  Disallows insertions into the out array.
+// Allows deletion from the out array only at the current point.
+// Usage:
+//  for (DUIterator_Fast imax, i = x->fast_outs(imax); i < imax; i++) {
+//    Node* y = x->fast_out(i);
+//    ...
+//  }
+// Compiles in product mode to raw Node** pointer arithmetic, with
+// no reloading of pointers from the original node x.  If you delete,
+// you must perform "--i; --imax" just before continuing the loop.
+// If you delete multiple copies of the same edge, you must decrement
+// imax, but not i, multiple times:  "--i, imax -= num_edges".
+class DUIterator_Fast : public DUIterator_Common {
+  friend class Node;
+  friend class DUIterator_Last;
+
+  // This is the pointer which provides the product-mode behavior.
+  // Whatever the product-mode version of the system does to the
+  // DUI pointer is done to this pointer.  All other fields in
+  // this class are used only for assertion checking.
+  Node**       _outp;
+
+  #ifdef ASSERT
+  void verify(const Node* node, bool at_end_ok = false);
+  void verify_limit();
+  void verify_resync();
+  void verify_relimit(uint n);
+  void reset(const DUIterator_Fast& that);
+  #endif
+
+  // Note:  offset must be signed, since -1 is sometimes passed
+  DUIterator_Fast(const Node* node, ptrdiff_t offset)
+    { _outp = node->_out + offset;      debug_only(sample(node)); }
+
+ public:
+  // initialize to garbage; clear _vdui to disable asserts
+  DUIterator_Fast()
+    { /*initialize to garbage*/         debug_only(_vdui = false); }
+
+  void operator++(int dummy_to_specify_postfix_op)
+    { _outp++;                          VDUI_ONLY(verify(_node, true)); }
+
+  void operator--()
+    { VDUI_ONLY(verify_resync());       --_outp; }
+
+  void operator-=(uint n)   // applied to the limit only
+    { _outp -= n;           VDUI_ONLY(verify_relimit(n));  }
+
+  bool operator<(DUIterator_Fast& limit) {
+    I_VDUI_ONLY(*this, this->verify(_node, true));
+    I_VDUI_ONLY(limit, limit.verify_limit());
+    return _outp < limit._outp;
+  }
+
+  void operator=(const DUIterator_Fast& that)
+    { _outp = that._outp;               debug_only(reset(that)); }
+};
+
+DUIterator_Fast Node::fast_outs(DUIterator_Fast& imax) const {
+  // Assign a limit pointer to the reference argument:
+  imax = DUIterator_Fast(this, (ptrdiff_t)_outcnt);
+  // Return the base pointer:
+  return DUIterator_Fast(this, 0);
+}
+Node* Node::fast_out(DUIterator_Fast& i) const {
+  I_VDUI_ONLY(i, i.verify(this));
+  return debug_only(i._last=) *i._outp;
+}
+
+
+// Faster DU iterator.  Requires each successive edge to be removed.
+// Does not allow insertion of any edges.
+// Usage:
+//  for (DUIterator_Last imin, i = x->last_outs(imin); i >= imin; i -= num_edges) {
+//    Node* y = x->last_out(i);
+//    ...
+//  }
+// Compiles in product mode to raw Node** pointer arithmetic, with
+// no reloading of pointers from the original node x.
+class DUIterator_Last : private DUIterator_Fast {
+  friend class Node;
+
+  #ifdef ASSERT
+  void verify(const Node* node, bool at_end_ok = false);
+  void verify_limit();
+  void verify_step(uint num_edges);
+  #endif
+
+  // Note:  offset must be signed, since -1 is sometimes passed
+  DUIterator_Last(const Node* node, ptrdiff_t offset)
+    : DUIterator_Fast(node, offset) { }
+
+  void operator++(int dummy_to_specify_postfix_op) {} // do not use
+  void operator<(int)                              {} // do not use
+
+ public:
+  DUIterator_Last() { }
+  // initialize to garbage
+
+  void operator--()
+    { _outp--;              VDUI_ONLY(verify_step(1));  }
+
+  void operator-=(uint n)
+    { _outp -= n;           VDUI_ONLY(verify_step(n));  }
+
+  bool operator>=(DUIterator_Last& limit) {
+    I_VDUI_ONLY(*this, this->verify(_node, true));
+    I_VDUI_ONLY(limit, limit.verify_limit());
+    return _outp >= limit._outp;
+  }
+
+  void operator=(const DUIterator_Last& that)
+    { DUIterator_Fast::operator=(that); }
+};
+
+DUIterator_Last Node::last_outs(DUIterator_Last& imin) const {
+  // Assign a limit pointer to the reference argument:
+  imin = DUIterator_Last(this, 0);
+  // Return the initial pointer:
+  return DUIterator_Last(this, (ptrdiff_t)_outcnt - 1);
+}
+Node* Node::last_out(DUIterator_Last& i) const {
+  I_VDUI_ONLY(i, i.verify(this));
+  return debug_only(i._last=) *i._outp;
+}
+
+#endif //OPTO_DU_ITERATOR_ASSERT
+
+#undef I_VDUI_ONLY
+#undef VDUI_ONLY
+
+
+//-----------------------------------------------------------------------------
+// Map dense integer indices to Nodes.  Uses classic doubling-array trick.
+// Abstractly provides an infinite array of Node*'s, initialized to NULL.
+// Note that the constructor just zeros things, and since I use Arena
+// allocation I do not need a destructor to reclaim storage.
+class Node_Array : public ResourceObj {
+protected:
+  Arena *_a;                    // Arena to allocate in
+  uint   _max;
+  Node **_nodes;
+  void   grow( uint i );        // Grow array node to fit
+public:
+  Node_Array(Arena *a) : _a(a), _max(OptoNodeListSize) {
+    _nodes = NEW_ARENA_ARRAY( a, Node *, OptoNodeListSize );
+    for( int i = 0; i < OptoNodeListSize; i++ ) {
+      _nodes[i] = NULL;
+    }
+  }
+
+  Node_Array(Node_Array *na) : _a(na->_a), _max(na->_max), _nodes(na->_nodes) {}
+  Node *operator[] ( uint i ) const // Lookup, or NULL for not mapped
+  { return (i<_max) ? _nodes[i] : (Node*)NULL; }
+  Node *at( uint i ) const { assert(i<_max,"oob"); return _nodes[i]; }
+  Node **adr() { return _nodes; }
+  // Extend the mapping: index i maps to Node *n.
+  void map( uint i, Node *n ) { if( i>=_max ) grow(i); _nodes[i] = n; }
+  void insert( uint i, Node *n );
+  void remove( uint i );        // Remove, preserving order
+  void sort( C_sort_func_t func);
+  void reset( Arena *new_a );   // Zap mapping to empty; reclaim storage
+  void clear();                 // Set all entries to NULL, keep storage
+  uint Size() const { return _max; }
+  void dump() const;
+};
+
+class Node_List : public Node_Array {
+  uint _cnt;
+public:
+  Node_List() : Node_Array(Thread::current()->resource_area()), _cnt(0) {}
+  Node_List(Arena *a) : Node_Array(a), _cnt(0) {}
+  void insert( uint i, Node *n ) { Node_Array::insert(i,n); _cnt++; }
+  void remove( uint i ) { Node_Array::remove(i); _cnt--; }
+  void push( Node *b ) { map(_cnt++,b); }
+  void yank( Node *n );         // Find and remove
+  Node *pop() { return _nodes[--_cnt]; }
+  Node *rpop() { Node *b = _nodes[0]; _nodes[0]=_nodes[--_cnt]; return b;}
+  void clear() { _cnt = 0; Node_Array::clear(); } // retain storage
+  uint size() const { return _cnt; }
+  void dump() const;
+};
+
+//------------------------------Unique_Node_List-------------------------------
+class Unique_Node_List : public Node_List {
+  VectorSet _in_worklist;
+  uint _clock_index;            // Index in list where to pop from next
+public:
+  Unique_Node_List() : Node_List(), _in_worklist(Thread::current()->resource_area()), _clock_index(0) {}
+  Unique_Node_List(Arena *a) : Node_List(a), _in_worklist(a), _clock_index(0) {}
+
+  void remove( Node *n );
+  bool member( Node *n ) { return _in_worklist.test(n->_idx) != 0; }
+  VectorSet &member_set(){ return _in_worklist; }
+
+  void push( Node *b ) {
+    if( !_in_worklist.test_set(b->_idx) )
+      Node_List::push(b);
+  }
+  Node *pop() {
+    if( _clock_index >= size() ) _clock_index = 0;
+    Node *b = at(_clock_index);
+    map( _clock_index++, Node_List::pop());
+    _in_worklist >>= b->_idx;
+    return b;
+  }
+  Node *remove( uint i ) {
+    Node *b = Node_List::at(i);
+    _in_worklist >>= b->_idx;
+    map(i,Node_List::pop());
+    return b;
+  }
+  void yank( Node *n ) { _in_worklist >>= n->_idx; Node_List::yank(n); }
+  void  clear() {
+    _in_worklist.Clear();        // Discards storage but grows automatically
+    Node_List::clear();
+    _clock_index = 0;
+  }
+
+  // Used after parsing to remove useless nodes before Iterative GVN
+  void remove_useless_nodes(VectorSet &useful);
+
+#ifndef PRODUCT
+  void print_set() const { _in_worklist.print(); }
+#endif
+};
+
+// Inline definition of Compile::record_for_igvn must be deferred to this point.
+inline void Compile::record_for_igvn(Node* n) {
+  _for_igvn->push(n);
+  record_for_escape_analysis(n);
+}
+
+//------------------------------Node_Stack-------------------------------------
+class Node_Stack {
+protected:
+  struct INode {
+    Node *node; // Processed node
+    uint  indx; // Index of next node's child
+  };
+  INode *_inode_top; // tos, stack grows up
+  INode *_inode_max; // End of _inodes == _inodes + _max
+  INode *_inodes;    // Array storage for the stack
+  Arena *_a;         // Arena to allocate in
+  void grow();
+public:
+  Node_Stack(int size) {
+    size_t max = (size > OptoNodeListSize) ? size : OptoNodeListSize;
+    _a = Thread::current()->resource_area();
+    _inodes = NEW_ARENA_ARRAY( _a, INode, max );
+    _inode_max = _inodes + max;
+    _inode_top = _inodes - 1; // stack is empty
+  }
+
+  Node_Stack(Arena *a, int size) : _a(a) {
+    size_t max = (size > OptoNodeListSize) ? size : OptoNodeListSize;
+    _inodes = NEW_ARENA_ARRAY( _a, INode, max );
+    _inode_max = _inodes + max;
+    _inode_top = _inodes - 1; // stack is empty
+  }
+
+  void pop() {
+    assert(_inode_top >= _inodes, "node stack underflow");
+    --_inode_top;
+  }
+  void push(Node *n, uint i) {
+    ++_inode_top;
+    if (_inode_top >= _inode_max) grow();
+    INode *top = _inode_top; // optimization
+    top->node = n;
+    top->indx = i;
+  }
+  Node *node() const {
+    return _inode_top->node;
+  }
+  Node* node_at(uint i) const {
+    assert(_inodes + i <= _inode_top, "in range");
+    return _inodes[i].node;
+  }
+  uint index() const {
+    return _inode_top->indx;
+  }
+  void set_node(Node *n) {
+    _inode_top->node = n;
+  }
+  void set_index(uint i) {
+    _inode_top->indx = i;
+  }
+  uint size_max() const { return (uint)pointer_delta(_inode_max, _inodes,  sizeof(INode)); } // Max size
+  uint size() const { return (uint)pointer_delta(_inode_top, _inodes,  sizeof(INode)) + 1; } // Current size
+  bool is_nonempty() const { return (_inode_top >= _inodes); }
+  bool is_empty() const { return (_inode_top < _inodes); }
+  void clear() { _inode_top = _inodes - 1; } // retain storage
+};
+
+
+//-----------------------------Node_Notes--------------------------------------
+// Debugging or profiling annotations loosely and sparsely associated
+// with some nodes.  See Compile::node_notes_at for the accessor.
+class Node_Notes VALUE_OBJ_CLASS_SPEC {
+  JVMState* _jvms;
+
+public:
+  Node_Notes(JVMState* jvms = NULL) {
+    _jvms = jvms;
+  }
+
+  JVMState* jvms()            { return _jvms; }
+  void  set_jvms(JVMState* x) {        _jvms = x; }
+
+  // True if there is nothing here.
+  bool is_clear() {
+    return (_jvms == NULL);
+  }
+
+  // Make there be nothing here.
+  void clear() {
+    _jvms = NULL;
+  }
+
+  // Make a new, clean node notes.
+  static Node_Notes* make(Compile* C) {
+    Node_Notes* nn = NEW_ARENA_ARRAY(C->comp_arena(), Node_Notes, 1);
+    nn->clear();
+    return nn;
+  }
+
+  Node_Notes* clone(Compile* C) {
+    Node_Notes* nn = NEW_ARENA_ARRAY(C->comp_arena(), Node_Notes, 1);
+    (*nn) = (*this);
+    return nn;
+  }
+
+  // Absorb any information from source.
+  bool update_from(Node_Notes* source) {
+    bool changed = false;
+    if (source != NULL) {
+      if (source->jvms() != NULL) {
+        set_jvms(source->jvms());
+        changed = true;
+      }
+    }
+    return changed;
+  }
+};
+
+// Inlined accessors for Compile::node_nodes that require the preceding class:
+inline Node_Notes*
+Compile::locate_node_notes(GrowableArray<Node_Notes*>* arr,
+                           int idx, bool can_grow) {
+  assert(idx >= 0, "oob");
+  int block_idx = (idx >> _log2_node_notes_block_size);
+  int grow_by = (block_idx - (arr == NULL? 0: arr->length()));
+  if (grow_by >= 0) {
+    if (!can_grow)  return NULL;
+    grow_node_notes(arr, grow_by + 1);
+  }
+  // (Every element of arr is a sub-array of length _node_notes_block_size.)
+  return arr->at(block_idx) + (idx & (_node_notes_block_size-1));
+}
+
+inline bool
+Compile::set_node_notes_at(int idx, Node_Notes* value) {
+  if (value == NULL || value->is_clear())
+    return false;  // nothing to write => write nothing
+  Node_Notes* loc = locate_node_notes(_node_note_array, idx, true);
+  assert(loc != NULL, "");
+  return loc->update_from(value);
+}
+
+
+//------------------------------TypeNode---------------------------------------
+// Node with a Type constant.
+class TypeNode : public Node {
+protected:
+  virtual uint hash() const;    // Check the type
+  virtual uint cmp( const Node &n ) const;
+  virtual uint size_of() const; // Size is bigger
+  const Type* const _type;
+public:
+  void set_type(const Type* t) {
+    assert(t != NULL, "sanity");
+    debug_only(uint check_hash = (VerifyHashTableKeys && _hash_lock) ? hash() : NO_HASH);
+    *(const Type**)&_type = t;   // cast away const-ness
+    // If this node is in the hash table, make sure it doesn't need a rehash.
+    assert(check_hash == NO_HASH || check_hash == hash(), "type change must preserve hash code");
+  }
+  const Type* type() const { assert(_type != NULL, "sanity"); return _type; };
+  TypeNode( const Type *t, uint required ) : Node(required), _type(t) {
+    init_class_id(Class_Type);
+  }
+  virtual const Type *Value( PhaseTransform *phase ) const;
+  virtual const Type *bottom_type() const;
+  virtual       uint  ideal_reg() const;
+#ifndef PRODUCT
+  virtual void dump_spec(outputStream *st) const;
+#endif
+};