diff -r fd16c54261b3 -r 489c9b5090e2 hotspot/src/share/vm/opto/memnode.hpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/opto/memnode.hpp	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,1062 @@
+/*
+ * 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
+
+class MultiNode;
+class PhaseCCP;
+class PhaseTransform;
+
+//------------------------------MemNode----------------------------------------
+// Load or Store, possibly throwing a NULL pointer exception
+class MemNode : public Node {
+protected:
+#ifdef ASSERT
+  const TypePtr* _adr_type;     // What kind of memory is being addressed?
+#endif
+  virtual uint size_of() const; // Size is bigger (ASSERT only)
+public:
+  enum { Control,               // When is it safe to do this load?
+         Memory,                // Chunk of memory is being loaded from
+         Address,               // Actually address, derived from base
+         ValueIn,               // Value to store
+         OopStore               // Preceeding oop store, only in StoreCM
+  };
+protected:
+  MemNode( Node *c0, Node *c1, Node *c2, const TypePtr* at )
+    : Node(c0,c1,c2   ) {
+    init_class_id(Class_Mem);
+    debug_only(_adr_type=at; adr_type();)
+  }
+  MemNode( Node *c0, Node *c1, Node *c2, const TypePtr* at, Node *c3 )
+    : Node(c0,c1,c2,c3) {
+    init_class_id(Class_Mem);
+    debug_only(_adr_type=at; adr_type();)
+  }
+  MemNode( Node *c0, Node *c1, Node *c2, const TypePtr* at, Node *c3, Node *c4)
+    : Node(c0,c1,c2,c3,c4) {
+    init_class_id(Class_Mem);
+    debug_only(_adr_type=at; adr_type();)
+  }
+
+  // Helpers for the optimizer.  Documented in memnode.cpp.
+  static bool detect_ptr_independence(Node* p1, AllocateNode* a1,
+                                      Node* p2, AllocateNode* a2,
+                                      PhaseTransform* phase);
+  static bool adr_phi_is_loop_invariant(Node* adr_phi, Node* cast);
+
+public:
+  // This one should probably be a phase-specific function:
+  static bool detect_dominating_control(Node* dom, Node* sub);
+
+  // Is this Node a MemNode or some descendent?  Default is YES.
+  virtual Node *Ideal_DU_postCCP( PhaseCCP *ccp );
+
+  virtual const class TypePtr *adr_type() const;  // returns bottom_type of address
+
+  // Shared code for Ideal methods:
+  Node *Ideal_common(PhaseGVN *phase, bool can_reshape);  // Return -1 for short-circuit NULL.
+
+  // Helper function for adr_type() implementations.
+  static const TypePtr* calculate_adr_type(const Type* t, const TypePtr* cross_check = NULL);
+
+  // Raw access function, to allow copying of adr_type efficiently in
+  // product builds and retain the debug info for debug builds.
+  const TypePtr *raw_adr_type() const {
+#ifdef ASSERT
+    return _adr_type;
+#else
+    return 0;
+#endif
+  }
+
+  // Map a load or store opcode to its corresponding store opcode.
+  // (Return -1 if unknown.)
+  virtual int store_Opcode() const { return -1; }
+
+  // What is the type of the value in memory?  (T_VOID mean "unspecified".)
+  virtual BasicType memory_type() const = 0;
+  virtual int memory_size() const { return type2aelembytes[memory_type()]; }
+
+  // Search through memory states which precede this node (load or store).
+  // Look for an exact match for the address, with no intervening
+  // aliased stores.
+  Node* find_previous_store(PhaseTransform* phase);
+
+  // Can this node (load or store) accurately see a stored value in
+  // the given memory state?  (The state may or may not be in(Memory).)
+  Node* can_see_stored_value(Node* st, PhaseTransform* phase) const;
+
+#ifndef PRODUCT
+  static void dump_adr_type(const Node* mem, const TypePtr* adr_type, outputStream *st);
+  virtual void dump_spec(outputStream *st) const;
+#endif
+};
+
+//------------------------------LoadNode---------------------------------------
+// Load value; requires Memory and Address
+class LoadNode : public MemNode {
+protected:
+  virtual uint cmp( const Node &n ) const;
+  virtual uint size_of() const; // Size is bigger
+  const Type* const _type;      // What kind of value is loaded?
+public:
+
+  LoadNode( Node *c, Node *mem, Node *adr, const TypePtr* at, const Type *rt )
+    : MemNode(c,mem,adr,at), _type(rt) {
+    init_class_id(Class_Load);
+  }
+
+  // Polymorphic factory method:
+  static LoadNode* make( Compile *C, Node *c, Node *mem, Node *adr, const TypePtr* at, const Type *rt, BasicType bt );
+
+  virtual uint hash()   const;  // Check the type
+
+  // Handle algebraic identities here.  If we have an identity, return the Node
+  // we are equivalent to.  We look for Load of a Store.
+  virtual Node *Identity( PhaseTransform *phase );
+
+  // If the load is from Field memory and the pointer is non-null, we can
+  // zero out the control input.
+  virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
+
+  // Compute a new Type for this node.  Basically we just do the pre-check,
+  // then call the virtual add() to set the type.
+  virtual const Type *Value( PhaseTransform *phase ) const;
+
+  virtual uint ideal_reg() const;
+  virtual const Type *bottom_type() const;
+  // Following method is copied from TypeNode:
+  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; };
+
+  // Do not match memory edge
+  virtual uint match_edge(uint idx) const;
+
+  // Map a load opcode to its corresponding store opcode.
+  virtual int store_Opcode() const = 0;
+
+#ifndef PRODUCT
+  virtual void dump_spec(outputStream *st) const;
+#endif
+protected:
+  const Type* load_array_final_field(const TypeKlassPtr *tkls,
+                                     ciKlass* klass) const;
+};
+
+//------------------------------LoadBNode--------------------------------------
+// Load a byte (8bits signed) from memory
+class LoadBNode : public LoadNode {
+public:
+  LoadBNode( Node *c, Node *mem, Node *adr, const TypePtr* at, const TypeInt *ti = TypeInt::BYTE )
+    : LoadNode(c,mem,adr,at,ti) {}
+  virtual int Opcode() const;
+  virtual uint ideal_reg() const { return Op_RegI; }
+  virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
+  virtual int store_Opcode() const { return Op_StoreB; }
+  virtual BasicType memory_type() const { return T_BYTE; }
+};
+
+//------------------------------LoadCNode--------------------------------------
+// Load a char (16bits unsigned) from memory
+class LoadCNode : public LoadNode {
+public:
+  LoadCNode( Node *c, Node *mem, Node *adr, const TypePtr* at, const TypeInt *ti = TypeInt::CHAR )
+    : LoadNode(c,mem,adr,at,ti) {}
+  virtual int Opcode() const;
+  virtual uint ideal_reg() const { return Op_RegI; }
+  virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
+  virtual int store_Opcode() const { return Op_StoreC; }
+  virtual BasicType memory_type() const { return T_CHAR; }
+};
+
+//------------------------------LoadINode--------------------------------------
+// Load an integer from memory
+class LoadINode : public LoadNode {
+public:
+  LoadINode( Node *c, Node *mem, Node *adr, const TypePtr* at, const TypeInt *ti = TypeInt::INT )
+    : LoadNode(c,mem,adr,at,ti) {}
+  virtual int Opcode() const;
+  virtual uint ideal_reg() const { return Op_RegI; }
+  virtual int store_Opcode() const { return Op_StoreI; }
+  virtual BasicType memory_type() const { return T_INT; }
+};
+
+//------------------------------LoadRangeNode----------------------------------
+// Load an array length from the array
+class LoadRangeNode : public LoadINode {
+public:
+  LoadRangeNode( Node *c, Node *mem, Node *adr, const TypeInt *ti = TypeInt::POS )
+    : LoadINode(c,mem,adr,TypeAryPtr::RANGE,ti) {}
+  virtual int Opcode() const;
+  virtual const Type *Value( PhaseTransform *phase ) const;
+  virtual Node *Identity( PhaseTransform *phase );
+};
+
+//------------------------------LoadLNode--------------------------------------
+// Load a long from memory
+class LoadLNode : public LoadNode {
+  virtual uint hash() const { return LoadNode::hash() + _require_atomic_access; }
+  virtual uint cmp( const Node &n ) const {
+    return _require_atomic_access == ((LoadLNode&)n)._require_atomic_access
+      && LoadNode::cmp(n);
+  }
+  virtual uint size_of() const { return sizeof(*this); }
+  const bool _require_atomic_access;  // is piecewise load forbidden?
+
+public:
+  LoadLNode( Node *c, Node *mem, Node *adr, const TypePtr* at,
+             const TypeLong *tl = TypeLong::LONG,
+             bool require_atomic_access = false )
+    : LoadNode(c,mem,adr,at,tl)
+    , _require_atomic_access(require_atomic_access)
+  {}
+  virtual int Opcode() const;
+  virtual uint ideal_reg() const { return Op_RegL; }
+  virtual int store_Opcode() const { return Op_StoreL; }
+  virtual BasicType memory_type() const { return T_LONG; }
+  bool require_atomic_access() { return _require_atomic_access; }
+  static LoadLNode* make_atomic(Compile *C, Node* ctl, Node* mem, Node* adr, const TypePtr* adr_type, const Type* rt);
+#ifndef PRODUCT
+  virtual void dump_spec(outputStream *st) const {
+    LoadNode::dump_spec(st);
+    if (_require_atomic_access)  st->print(" Atomic!");
+  }
+#endif
+};
+
+//------------------------------LoadL_unalignedNode----------------------------
+// Load a long from unaligned memory
+class LoadL_unalignedNode : public LoadLNode {
+public:
+  LoadL_unalignedNode( Node *c, Node *mem, Node *adr, const TypePtr* at )
+    : LoadLNode(c,mem,adr,at) {}
+  virtual int Opcode() const;
+};
+
+//------------------------------LoadFNode--------------------------------------
+// Load a float (64 bits) from memory
+class LoadFNode : public LoadNode {
+public:
+  LoadFNode( Node *c, Node *mem, Node *adr, const TypePtr* at, const Type *t = Type::FLOAT )
+    : LoadNode(c,mem,adr,at,t) {}
+  virtual int Opcode() const;
+  virtual uint ideal_reg() const { return Op_RegF; }
+  virtual int store_Opcode() const { return Op_StoreF; }
+  virtual BasicType memory_type() const { return T_FLOAT; }
+};
+
+//------------------------------LoadDNode--------------------------------------
+// Load a double (64 bits) from memory
+class LoadDNode : public LoadNode {
+public:
+  LoadDNode( Node *c, Node *mem, Node *adr, const TypePtr* at, const Type *t = Type::DOUBLE )
+    : LoadNode(c,mem,adr,at,t) {}
+  virtual int Opcode() const;
+  virtual uint ideal_reg() const { return Op_RegD; }
+  virtual int store_Opcode() const { return Op_StoreD; }
+  virtual BasicType memory_type() const { return T_DOUBLE; }
+};
+
+//------------------------------LoadD_unalignedNode----------------------------
+// Load a double from unaligned memory
+class LoadD_unalignedNode : public LoadDNode {
+public:
+  LoadD_unalignedNode( Node *c, Node *mem, Node *adr, const TypePtr* at )
+    : LoadDNode(c,mem,adr,at) {}
+  virtual int Opcode() const;
+};
+
+//------------------------------LoadPNode--------------------------------------
+// Load a pointer from memory (either object or array)
+class LoadPNode : public LoadNode {
+public:
+  LoadPNode( Node *c, Node *mem, Node *adr, const TypePtr *at, const TypePtr* t )
+    : LoadNode(c,mem,adr,at,t) {}
+  virtual int Opcode() const;
+  virtual uint ideal_reg() const { return Op_RegP; }
+  virtual int store_Opcode() const { return Op_StoreP; }
+  virtual BasicType memory_type() const { return T_ADDRESS; }
+  // depends_only_on_test is almost always true, and needs to be almost always
+  // true to enable key hoisting & commoning optimizations.  However, for the
+  // special case of RawPtr loads from TLS top & end, the control edge carries
+  // the dependence preventing hoisting past a Safepoint instead of the memory
+  // edge.  (An unfortunate consequence of having Safepoints not set Raw
+  // Memory; itself an unfortunate consequence of having Nodes which produce
+  // results (new raw memory state) inside of loops preventing all manner of
+  // other optimizations).  Basically, it's ugly but so is the alternative.
+  // See comment in macro.cpp, around line 125 expand_allocate_common().
+  virtual bool depends_only_on_test() const { return adr_type() != TypeRawPtr::BOTTOM; }
+};
+
+//------------------------------LoadKlassNode----------------------------------
+// Load a Klass from an object
+class LoadKlassNode : public LoadPNode {
+public:
+  LoadKlassNode( Node *c, Node *mem, Node *adr, const TypePtr *at, const TypeKlassPtr *tk = TypeKlassPtr::OBJECT )
+    : LoadPNode(c,mem,adr,at,tk) {}
+  virtual int Opcode() const;
+  virtual const Type *Value( PhaseTransform *phase ) const;
+  virtual Node *Identity( PhaseTransform *phase );
+  virtual bool depends_only_on_test() const { return true; }
+};
+
+//------------------------------LoadSNode--------------------------------------
+// Load a short (16bits signed) from memory
+class LoadSNode : public LoadNode {
+public:
+  LoadSNode( Node *c, Node *mem, Node *adr, const TypePtr* at, const TypeInt *ti = TypeInt::SHORT )
+    : LoadNode(c,mem,adr,at,ti) {}
+  virtual int Opcode() const;
+  virtual uint ideal_reg() const { return Op_RegI; }
+  virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
+  virtual int store_Opcode() const { return Op_StoreC; }
+  virtual BasicType memory_type() const { return T_SHORT; }
+};
+
+//------------------------------StoreNode--------------------------------------
+// Store value; requires Store, Address and Value
+class StoreNode : public MemNode {
+protected:
+  virtual uint cmp( const Node &n ) const;
+  virtual bool depends_only_on_test() const { return false; }
+
+  Node *Ideal_masked_input       (PhaseGVN *phase, uint mask);
+  Node *Ideal_sign_extended_input(PhaseGVN *phase, int  num_bits);
+
+public:
+  StoreNode( Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val )
+    : MemNode(c,mem,adr,at,val) {
+    init_class_id(Class_Store);
+  }
+  StoreNode( Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, Node *oop_store )
+    : MemNode(c,mem,adr,at,val,oop_store) {
+    init_class_id(Class_Store);
+  }
+
+  // Polymorphic factory method:
+  static StoreNode* make( Compile *C, Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, BasicType bt );
+
+  virtual uint hash() const;    // Check the type
+
+  // If the store is to Field memory and the pointer is non-null, we can
+  // zero out the control input.
+  virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
+
+  // Compute a new Type for this node.  Basically we just do the pre-check,
+  // then call the virtual add() to set the type.
+  virtual const Type *Value( PhaseTransform *phase ) const;
+
+  // Check for identity function on memory (Load then Store at same address)
+  virtual Node *Identity( PhaseTransform *phase );
+
+  // Do not match memory edge
+  virtual uint match_edge(uint idx) const;
+
+  virtual const Type *bottom_type() const;  // returns Type::MEMORY
+
+  // Map a store opcode to its corresponding own opcode, trivially.
+  virtual int store_Opcode() const { return Opcode(); }
+
+  // have all possible loads of the value stored been optimized away?
+  bool value_never_loaded(PhaseTransform *phase) const;
+};
+
+//------------------------------StoreBNode-------------------------------------
+// Store byte to memory
+class StoreBNode : public StoreNode {
+public:
+  StoreBNode( Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val ) : StoreNode(c,mem,adr,at,val) {}
+  virtual int Opcode() const;
+  virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
+  virtual BasicType memory_type() const { return T_BYTE; }
+};
+
+//------------------------------StoreCNode-------------------------------------
+// Store char/short to memory
+class StoreCNode : public StoreNode {
+public:
+  StoreCNode( Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val ) : StoreNode(c,mem,adr,at,val) {}
+  virtual int Opcode() const;
+  virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
+  virtual BasicType memory_type() const { return T_CHAR; }
+};
+
+//------------------------------StoreINode-------------------------------------
+// Store int to memory
+class StoreINode : public StoreNode {
+public:
+  StoreINode( Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val ) : StoreNode(c,mem,adr,at,val) {}
+  virtual int Opcode() const;
+  virtual BasicType memory_type() const { return T_INT; }
+};
+
+//------------------------------StoreLNode-------------------------------------
+// Store long to memory
+class StoreLNode : public StoreNode {
+  virtual uint hash() const { return StoreNode::hash() + _require_atomic_access; }
+  virtual uint cmp( const Node &n ) const {
+    return _require_atomic_access == ((StoreLNode&)n)._require_atomic_access
+      && StoreNode::cmp(n);
+  }
+  virtual uint size_of() const { return sizeof(*this); }
+  const bool _require_atomic_access;  // is piecewise store forbidden?
+
+public:
+  StoreLNode( Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val,
+              bool require_atomic_access = false )
+    : StoreNode(c,mem,adr,at,val)
+    , _require_atomic_access(require_atomic_access)
+  {}
+  virtual int Opcode() const;
+  virtual BasicType memory_type() const { return T_LONG; }
+  bool require_atomic_access() { return _require_atomic_access; }
+  static StoreLNode* make_atomic(Compile *C, Node* ctl, Node* mem, Node* adr, const TypePtr* adr_type, Node* val);
+#ifndef PRODUCT
+  virtual void dump_spec(outputStream *st) const {
+    StoreNode::dump_spec(st);
+    if (_require_atomic_access)  st->print(" Atomic!");
+  }
+#endif
+};
+
+//------------------------------StoreFNode-------------------------------------
+// Store float to memory
+class StoreFNode : public StoreNode {
+public:
+  StoreFNode( Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val ) : StoreNode(c,mem,adr,at,val) {}
+  virtual int Opcode() const;
+  virtual BasicType memory_type() const { return T_FLOAT; }
+};
+
+//------------------------------StoreDNode-------------------------------------
+// Store double to memory
+class StoreDNode : public StoreNode {
+public:
+  StoreDNode( Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val ) : StoreNode(c,mem,adr,at,val) {}
+  virtual int Opcode() const;
+  virtual BasicType memory_type() const { return T_DOUBLE; }
+};
+
+//------------------------------StorePNode-------------------------------------
+// Store pointer to memory
+class StorePNode : public StoreNode {
+public:
+  StorePNode( Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val ) : StoreNode(c,mem,adr,at,val) {}
+  virtual int Opcode() const;
+  virtual BasicType memory_type() const { return T_ADDRESS; }
+};
+
+//------------------------------StoreCMNode-----------------------------------
+// Store card-mark byte to memory for CM
+// The last StoreCM before a SafePoint must be preserved and occur after its "oop" store
+// Preceeding equivalent StoreCMs may be eliminated.
+class StoreCMNode : public StoreNode {
+public:
+  StoreCMNode( Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, Node *oop_store ) : StoreNode(c,mem,adr,at,val,oop_store) {}
+  virtual int Opcode() const;
+  virtual Node *Identity( PhaseTransform *phase );
+  virtual const Type *Value( PhaseTransform *phase ) const;
+  virtual BasicType memory_type() const { return T_VOID; } // unspecific
+};
+
+//------------------------------LoadPLockedNode---------------------------------
+// Load-locked a pointer from memory (either object or array).
+// On Sparc & Intel this is implemented as a normal pointer load.
+// On PowerPC and friends it's a real load-locked.
+class LoadPLockedNode : public LoadPNode {
+public:
+  LoadPLockedNode( Node *c, Node *mem, Node *adr )
+    : LoadPNode(c,mem,adr,TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM) {}
+  virtual int Opcode() const;
+  virtual int store_Opcode() const { return Op_StorePConditional; }
+  virtual bool depends_only_on_test() const { return true; }
+};
+
+//------------------------------LoadLLockedNode---------------------------------
+// Load-locked a pointer from memory (either object or array).
+// On Sparc & Intel this is implemented as a normal long load.
+class LoadLLockedNode : public LoadLNode {
+public:
+  LoadLLockedNode( Node *c, Node *mem, Node *adr )
+    : LoadLNode(c,mem,adr,TypeRawPtr::BOTTOM, TypeLong::LONG) {}
+  virtual int Opcode() const;
+  virtual int store_Opcode() const { return Op_StoreLConditional; }
+};
+
+//------------------------------SCMemProjNode---------------------------------------
+// This class defines a projection of the memory  state of a store conditional node.
+// These nodes return a value, but also update memory.
+class SCMemProjNode : public ProjNode {
+public:
+  enum {SCMEMPROJCON = (uint)-2};
+  SCMemProjNode( Node *src) : ProjNode( src, SCMEMPROJCON) { }
+  virtual int Opcode() const;
+  virtual bool      is_CFG() const  { return false; }
+  virtual const Type *bottom_type() const {return Type::MEMORY;}
+  virtual const TypePtr *adr_type() const { return in(0)->in(MemNode::Memory)->adr_type();}
+  virtual uint ideal_reg() const { return 0;} // memory projections don't have a register
+  virtual const Type *Value( PhaseTransform *phase ) const;
+#ifndef PRODUCT
+  virtual void dump_spec(outputStream *st) const {};
+#endif
+};
+
+//------------------------------LoadStoreNode---------------------------
+class LoadStoreNode : public Node {
+public:
+  enum {
+    ExpectedIn = MemNode::ValueIn+1 // One more input than MemNode
+  };
+  LoadStoreNode( Node *c, Node *mem, Node *adr, Node *val, Node *ex);
+  virtual bool depends_only_on_test() const { return false; }
+  virtual const Type *bottom_type() const { return TypeInt::BOOL; }
+  virtual uint ideal_reg() const { return Op_RegI; }
+  virtual uint match_edge(uint idx) const { return idx == MemNode::Address || idx == MemNode::ValueIn; }
+};
+
+//------------------------------StorePConditionalNode---------------------------
+// Conditionally store pointer to memory, if no change since prior
+// load-locked.  Sets flags for success or failure of the store.
+class StorePConditionalNode : public LoadStoreNode {
+public:
+  StorePConditionalNode( Node *c, Node *mem, Node *adr, Node *val, Node *ll ) : LoadStoreNode(c, mem, adr, val, ll) { }
+  virtual int Opcode() const;
+  // Produces flags
+  virtual uint ideal_reg() const { return Op_RegFlags; }
+};
+
+//------------------------------StoreLConditionalNode---------------------------
+// Conditionally store long to memory, if no change since prior
+// load-locked.  Sets flags for success or failure of the store.
+class StoreLConditionalNode : public LoadStoreNode {
+public:
+  StoreLConditionalNode( Node *c, Node *mem, Node *adr, Node *val, Node *ll ) : LoadStoreNode(c, mem, adr, val, ll) { }
+  virtual int Opcode() const;
+};
+
+
+//------------------------------CompareAndSwapLNode---------------------------
+class CompareAndSwapLNode : public LoadStoreNode {
+public:
+  CompareAndSwapLNode( Node *c, Node *mem, Node *adr, Node *val, Node *ex) : LoadStoreNode(c, mem, adr, val, ex) { }
+  virtual int Opcode() const;
+};
+
+
+//------------------------------CompareAndSwapINode---------------------------
+class CompareAndSwapINode : public LoadStoreNode {
+public:
+  CompareAndSwapINode( Node *c, Node *mem, Node *adr, Node *val, Node *ex) : LoadStoreNode(c, mem, adr, val, ex) { }
+  virtual int Opcode() const;
+};
+
+
+//------------------------------CompareAndSwapPNode---------------------------
+class CompareAndSwapPNode : public LoadStoreNode {
+public:
+  CompareAndSwapPNode( Node *c, Node *mem, Node *adr, Node *val, Node *ex) : LoadStoreNode(c, mem, adr, val, ex) { }
+  virtual int Opcode() const;
+};
+
+//------------------------------ClearArray-------------------------------------
+class ClearArrayNode: public Node {
+public:
+  ClearArrayNode( Node *ctrl, Node *arymem, Node *word_cnt, Node *base ) : Node(ctrl,arymem,word_cnt,base) {}
+  virtual int         Opcode() const;
+  virtual const Type *bottom_type() const { return Type::MEMORY; }
+  // ClearArray modifies array elements, and so affects only the
+  // array memory addressed by the bottom_type of its base address.
+  virtual const class TypePtr *adr_type() const;
+  virtual Node *Identity( PhaseTransform *phase );
+  virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
+  virtual uint match_edge(uint idx) const;
+
+  // Clear the given area of an object or array.
+  // The start offset must always be aligned mod BytesPerInt.
+  // The end offset must always be aligned mod BytesPerLong.
+  // Return the new memory.
+  static Node* clear_memory(Node* control, Node* mem, Node* dest,
+                            intptr_t start_offset,
+                            intptr_t end_offset,
+                            PhaseGVN* phase);
+  static Node* clear_memory(Node* control, Node* mem, Node* dest,
+                            intptr_t start_offset,
+                            Node* end_offset,
+                            PhaseGVN* phase);
+  static Node* clear_memory(Node* control, Node* mem, Node* dest,
+                            Node* start_offset,
+                            Node* end_offset,
+                            PhaseGVN* phase);
+};
+
+//------------------------------StrComp-------------------------------------
+class StrCompNode: public Node {
+public:
+  StrCompNode(Node *control,
+              Node* char_array_mem,
+              Node* value_mem,
+              Node* count_mem,
+              Node* offset_mem,
+              Node* s1, Node* s2): Node(control,
+                                        char_array_mem,
+                                        value_mem,
+                                        count_mem,
+                                        offset_mem,
+                                        s1, s2) {};
+  virtual int Opcode() const;
+  virtual bool depends_only_on_test() const { return false; }
+  virtual const Type* bottom_type() const { return TypeInt::INT; }
+  // a StrCompNode (conservatively) aliases with everything:
+  virtual const TypePtr* adr_type() const { return TypePtr::BOTTOM; }
+  virtual uint match_edge(uint idx) const;
+  virtual uint ideal_reg() const { return Op_RegI; }
+  virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
+};
+
+//------------------------------MemBar-----------------------------------------
+// There are different flavors of Memory Barriers to match the Java Memory
+// Model.  Monitor-enter and volatile-load act as Aquires: no following ref
+// can be moved to before them.  We insert a MemBar-Acquire after a FastLock or
+// volatile-load.  Monitor-exit and volatile-store act as Release: no
+// preceeding ref can be moved to after them.  We insert a MemBar-Release
+// before a FastUnlock or volatile-store.  All volatiles need to be
+// serialized, so we follow all volatile-stores with a MemBar-Volatile to
+// seperate it from any following volatile-load.
+class MemBarNode: public MultiNode {
+  virtual uint hash() const ;                  // { return NO_HASH; }
+  virtual uint cmp( const Node &n ) const ;    // Always fail, except on self
+
+  virtual uint size_of() const { return sizeof(*this); }
+  // Memory type this node is serializing.  Usually either rawptr or bottom.
+  const TypePtr* _adr_type;
+
+public:
+  enum {
+    Precedent = TypeFunc::Parms  // optional edge to force precedence
+  };
+  MemBarNode(Compile* C, int alias_idx, Node* precedent);
+  virtual int Opcode() const = 0;
+  virtual const class TypePtr *adr_type() const { return _adr_type; }
+  virtual const Type *Value( PhaseTransform *phase ) const;
+  virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
+  virtual uint match_edge(uint idx) const { return 0; }
+  virtual const Type *bottom_type() const { return TypeTuple::MEMBAR; }
+  virtual Node *match( const ProjNode *proj, const Matcher *m );
+  // Factory method.  Builds a wide or narrow membar.
+  // Optional 'precedent' becomes an extra edge if not null.
+  static MemBarNode* make(Compile* C, int opcode,
+                          int alias_idx = Compile::AliasIdxBot,
+                          Node* precedent = NULL);
+};
+
+// "Acquire" - no following ref can move before (but earlier refs can
+// follow, like an early Load stalled in cache).  Requires multi-cpu
+// visibility.  Inserted after a volatile load or FastLock.
+class MemBarAcquireNode: public MemBarNode {
+public:
+  MemBarAcquireNode(Compile* C, int alias_idx, Node* precedent)
+    : MemBarNode(C, alias_idx, precedent) {}
+  virtual int Opcode() const;
+};
+
+// "Release" - no earlier ref can move after (but later refs can move
+// up, like a speculative pipelined cache-hitting Load).  Requires
+// multi-cpu visibility.  Inserted before a volatile store or FastUnLock.
+class MemBarReleaseNode: public MemBarNode {
+public:
+  MemBarReleaseNode(Compile* C, int alias_idx, Node* precedent)
+    : MemBarNode(C, alias_idx, precedent) {}
+  virtual int Opcode() const;
+};
+
+// Ordering between a volatile store and a following volatile load.
+// Requires multi-CPU visibility?
+class MemBarVolatileNode: public MemBarNode {
+public:
+  MemBarVolatileNode(Compile* C, int alias_idx, Node* precedent)
+    : MemBarNode(C, alias_idx, precedent) {}
+  virtual int Opcode() const;
+};
+
+// Ordering within the same CPU.  Used to order unsafe memory references
+// inside the compiler when we lack alias info.  Not needed "outside" the
+// compiler because the CPU does all the ordering for us.
+class MemBarCPUOrderNode: public MemBarNode {
+public:
+  MemBarCPUOrderNode(Compile* C, int alias_idx, Node* precedent)
+    : MemBarNode(C, alias_idx, precedent) {}
+  virtual int Opcode() const;
+  virtual uint ideal_reg() const { return 0; } // not matched in the AD file
+};
+
+// Isolation of object setup after an AllocateNode and before next safepoint.
+// (See comment in memnode.cpp near InitializeNode::InitializeNode for semantics.)
+class InitializeNode: public MemBarNode {
+  friend class AllocateNode;
+
+  bool _is_complete;
+
+public:
+  enum {
+    Control    = TypeFunc::Control,
+    Memory     = TypeFunc::Memory,     // MergeMem for states affected by this op
+    RawAddress = TypeFunc::Parms+0,    // the newly-allocated raw address
+    RawStores  = TypeFunc::Parms+1     // zero or more stores (or TOP)
+  };
+
+  InitializeNode(Compile* C, int adr_type, Node* rawoop);
+  virtual int Opcode() const;
+  virtual uint size_of() const { return sizeof(*this); }
+  virtual uint ideal_reg() const { return 0; } // not matched in the AD file
+  virtual const RegMask &in_RegMask(uint) const;  // mask for RawAddress
+
+  // Manage incoming memory edges via a MergeMem on in(Memory):
+  Node* memory(uint alias_idx);
+
+  // The raw memory edge coming directly from the Allocation.
+  // The contents of this memory are *always* all-zero-bits.
+  Node* zero_memory() { return memory(Compile::AliasIdxRaw); }
+
+  // Return the corresponding allocation for this initialization (or null if none).
+  // (Note: Both InitializeNode::allocation and AllocateNode::initialization
+  // are defined in graphKit.cpp, which sets up the bidirectional relation.)
+  AllocateNode* allocation();
+
+  // Anything other than zeroing in this init?
+  bool is_non_zero();
+
+  // An InitializeNode must completed before macro expansion is done.
+  // Completion requires that the AllocateNode must be followed by
+  // initialization of the new memory to zero, then to any initializers.
+  bool is_complete() { return _is_complete; }
+
+  // Mark complete.  (Must not yet be complete.)
+  void set_complete(PhaseGVN* phase);
+
+#ifdef ASSERT
+  // ensure all non-degenerate stores are ordered and non-overlapping
+  bool stores_are_sane(PhaseTransform* phase);
+#endif //ASSERT
+
+  // See if this store can be captured; return offset where it initializes.
+  // Return 0 if the store cannot be moved (any sort of problem).
+  intptr_t can_capture_store(StoreNode* st, PhaseTransform* phase);
+
+  // Capture another store; reformat it to write my internal raw memory.
+  // Return the captured copy, else NULL if there is some sort of problem.
+  Node* capture_store(StoreNode* st, intptr_t start, PhaseTransform* phase);
+
+  // Find captured store which corresponds to the range [start..start+size).
+  // Return my own memory projection (meaning the initial zero bits)
+  // if there is no such store.  Return NULL if there is a problem.
+  Node* find_captured_store(intptr_t start, int size_in_bytes, PhaseTransform* phase);
+
+  // Called when the associated AllocateNode is expanded into CFG.
+  Node* complete_stores(Node* rawctl, Node* rawmem, Node* rawptr,
+                        intptr_t header_size, Node* size_in_bytes,
+                        PhaseGVN* phase);
+
+ private:
+  void remove_extra_zeroes();
+
+  // Find out where a captured store should be placed (or already is placed).
+  int captured_store_insertion_point(intptr_t start, int size_in_bytes,
+                                     PhaseTransform* phase);
+
+  static intptr_t get_store_offset(Node* st, PhaseTransform* phase);
+
+  Node* make_raw_address(intptr_t offset, PhaseTransform* phase);
+
+  bool detect_init_independence(Node* n, bool st_is_pinned, int& count);
+
+  void coalesce_subword_stores(intptr_t header_size, Node* size_in_bytes,
+                               PhaseGVN* phase);
+
+  intptr_t find_next_fullword_store(uint i, PhaseGVN* phase);
+};
+
+//------------------------------MergeMem---------------------------------------
+// (See comment in memnode.cpp near MergeMemNode::MergeMemNode for semantics.)
+class MergeMemNode: public Node {
+  virtual uint hash() const ;                  // { return NO_HASH; }
+  virtual uint cmp( const Node &n ) const ;    // Always fail, except on self
+  friend class MergeMemStream;
+  MergeMemNode(Node* def);  // clients use MergeMemNode::make
+
+public:
+  // If the input is a whole memory state, clone it with all its slices intact.
+  // Otherwise, make a new memory state with just that base memory input.
+  // In either case, the result is a newly created MergeMem.
+  static MergeMemNode* make(Compile* C, Node* base_memory);
+
+  virtual int Opcode() const;
+  virtual Node *Identity( PhaseTransform *phase );
+  virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
+  virtual uint ideal_reg() const { return NotAMachineReg; }
+  virtual uint match_edge(uint idx) const { return 0; }
+  virtual const RegMask &out_RegMask() const;
+  virtual const Type *bottom_type() const { return Type::MEMORY; }
+  virtual const TypePtr *adr_type() const { return TypePtr::BOTTOM; }
+  // sparse accessors
+  // Fetch the previously stored "set_memory_at", or else the base memory.
+  // (Caller should clone it if it is a phi-nest.)
+  Node* memory_at(uint alias_idx) const;
+  // set the memory, regardless of its previous value
+  void set_memory_at(uint alias_idx, Node* n);
+  // the "base" is the memory that provides the non-finite support
+  Node* base_memory() const       { return in(Compile::AliasIdxBot); }
+  // warning: setting the base can implicitly set any of the other slices too
+  void set_base_memory(Node* def);
+  // sentinel value which denotes a copy of the base memory:
+  Node*   empty_memory() const    { return in(Compile::AliasIdxTop); }
+  static Node* make_empty_memory(); // where the sentinel comes from
+  bool is_empty_memory(Node* n) const { assert((n == empty_memory()) == n->is_top(), "sanity"); return n->is_top(); }
+  // hook for the iterator, to perform any necessary setup
+  void iteration_setup(const MergeMemNode* other = NULL);
+  // push sentinels until I am at least as long as the other (semantic no-op)
+  void grow_to_match(const MergeMemNode* other);
+  bool verify_sparse() const PRODUCT_RETURN0;
+#ifndef PRODUCT
+  virtual void dump_spec(outputStream *st) const;
+#endif
+};
+
+class MergeMemStream : public StackObj {
+ private:
+  MergeMemNode*       _mm;
+  const MergeMemNode* _mm2;  // optional second guy, contributes non-empty iterations
+  Node*               _mm_base;  // loop-invariant base memory of _mm
+  int                 _idx;
+  int                 _cnt;
+  Node*               _mem;
+  Node*               _mem2;
+  int                 _cnt2;
+
+  void init(MergeMemNode* mm, const MergeMemNode* mm2 = NULL) {
+    // subsume_node will break sparseness at times, whenever a memory slice
+    // folds down to a copy of the base ("fat") memory.  In such a case,
+    // the raw edge will update to base, although it should be top.
+    // This iterator will recognize either top or base_memory as an
+    // "empty" slice.  See is_empty, is_empty2, and next below.
+    //
+    // The sparseness property is repaired in MergeMemNode::Ideal.
+    // As long as access to a MergeMem goes through this iterator
+    // or the memory_at accessor, flaws in the sparseness will
+    // never be observed.
+    //
+    // Also, iteration_setup repairs sparseness.
+    assert(mm->verify_sparse(), "please, no dups of base");
+    assert(mm2==NULL || mm2->verify_sparse(), "please, no dups of base");
+
+    _mm  = mm;
+    _mm_base = mm->base_memory();
+    _mm2 = mm2;
+    _cnt = mm->req();
+    _idx = Compile::AliasIdxBot-1; // start at the base memory
+    _mem = NULL;
+    _mem2 = NULL;
+  }
+
+#ifdef ASSERT
+  Node* check_memory() const {
+    if (at_base_memory())
+      return _mm->base_memory();
+    else if ((uint)_idx < _mm->req() && !_mm->in(_idx)->is_top())
+      return _mm->memory_at(_idx);
+    else
+      return _mm_base;
+  }
+  Node* check_memory2() const {
+    return at_base_memory()? _mm2->base_memory(): _mm2->memory_at(_idx);
+  }
+#endif
+
+  static bool match_memory(Node* mem, const MergeMemNode* mm, int idx) PRODUCT_RETURN0;
+  void assert_synch() const {
+    assert(!_mem || _idx >= _cnt || match_memory(_mem, _mm, _idx),
+           "no side-effects except through the stream");
+  }
+
+ public:
+
+  // expected usages:
+  // for (MergeMemStream mms(mem->is_MergeMem()); next_non_empty(); ) { ... }
+  // for (MergeMemStream mms(mem1, mem2); next_non_empty2(); ) { ... }
+
+  // iterate over one merge
+  MergeMemStream(MergeMemNode* mm) {
+    mm->iteration_setup();
+    init(mm);
+    debug_only(_cnt2 = 999);
+  }
+  // iterate in parallel over two merges
+  // only iterates through non-empty elements of mm2
+  MergeMemStream(MergeMemNode* mm, const MergeMemNode* mm2) {
+    assert(mm2, "second argument must be a MergeMem also");
+    ((MergeMemNode*)mm2)->iteration_setup();  // update hidden state
+    mm->iteration_setup(mm2);
+    init(mm, mm2);
+    _cnt2 = mm2->req();
+  }
+#ifdef ASSERT
+  ~MergeMemStream() {
+    assert_synch();
+  }
+#endif
+
+  MergeMemNode* all_memory() const {
+    return _mm;
+  }
+  Node* base_memory() const {
+    assert(_mm_base == _mm->base_memory(), "no update to base memory, please");
+    return _mm_base;
+  }
+  const MergeMemNode* all_memory2() const {
+    assert(_mm2 != NULL, "");
+    return _mm2;
+  }
+  bool at_base_memory() const {
+    return _idx == Compile::AliasIdxBot;
+  }
+  int alias_idx() const {
+    assert(_mem, "must call next 1st");
+    return _idx;
+  }
+
+  const TypePtr* adr_type() const {
+    return Compile::current()->get_adr_type(alias_idx());
+  }
+
+  const TypePtr* adr_type(Compile* C) const {
+    return C->get_adr_type(alias_idx());
+  }
+  bool is_empty() const {
+    assert(_mem, "must call next 1st");
+    assert(_mem->is_top() == (_mem==_mm->empty_memory()), "correct sentinel");
+    return _mem->is_top();
+  }
+  bool is_empty2() const {
+    assert(_mem2, "must call next 1st");
+    assert(_mem2->is_top() == (_mem2==_mm2->empty_memory()), "correct sentinel");
+    return _mem2->is_top();
+  }
+  Node* memory() const {
+    assert(!is_empty(), "must not be empty");
+    assert_synch();
+    return _mem;
+  }
+  // get the current memory, regardless of empty or non-empty status
+  Node* force_memory() const {
+    assert(!is_empty() || !at_base_memory(), "");
+    // Use _mm_base to defend against updates to _mem->base_memory().
+    Node *mem = _mem->is_top() ? _mm_base : _mem;
+    assert(mem == check_memory(), "");
+    return mem;
+  }
+  Node* memory2() const {
+    assert(_mem2 == check_memory2(), "");
+    return _mem2;
+  }
+  void set_memory(Node* mem) {
+    if (at_base_memory()) {
+      // Note that this does not change the invariant _mm_base.
+      _mm->set_base_memory(mem);
+    } else {
+      _mm->set_memory_at(_idx, mem);
+    }
+    _mem = mem;
+    assert_synch();
+  }
+
+  // Recover from a side effect to the MergeMemNode.
+  void set_memory() {
+    _mem = _mm->in(_idx);
+  }
+
+  bool next()  { return next(false); }
+  bool next2() { return next(true); }
+
+  bool next_non_empty()  { return next_non_empty(false); }
+  bool next_non_empty2() { return next_non_empty(true); }
+  // next_non_empty2 can yield states where is_empty() is true
+
+ private:
+  // find the next item, which might be empty
+  bool next(bool have_mm2) {
+    assert((_mm2 != NULL) == have_mm2, "use other next");
+    assert_synch();
+    if (++_idx < _cnt) {
+      // Note:  This iterator allows _mm to be non-sparse.
+      // It behaves the same whether _mem is top or base_memory.
+      _mem = _mm->in(_idx);
+      if (have_mm2)
+        _mem2 = _mm2->in((_idx < _cnt2) ? _idx : Compile::AliasIdxTop);
+      return true;
+    }
+    return false;
+  }
+
+  // find the next non-empty item
+  bool next_non_empty(bool have_mm2) {
+    while (next(have_mm2)) {
+      if (!is_empty()) {
+        // make sure _mem2 is filled in sensibly
+        if (have_mm2 && _mem2->is_top())  _mem2 = _mm2->base_memory();
+        return true;
+      } else if (have_mm2 && !is_empty2()) {
+        return true;   // is_empty() == true
+      }
+    }
+    return false;
+  }
+};
+
+//------------------------------Prefetch---------------------------------------
+
+// Non-faulting prefetch load.  Prefetch for many reads.
+class PrefetchReadNode : public Node {
+public:
+  PrefetchReadNode(Node *abio, Node *adr) : Node(0,abio,adr) {}
+  virtual int Opcode() const;
+  virtual uint ideal_reg() const { return NotAMachineReg; }
+  virtual uint match_edge(uint idx) const { return idx==2; }
+  virtual const Type *bottom_type() const { return Type::ABIO; }
+};
+
+// Non-faulting prefetch load.  Prefetch for many reads & many writes.
+class PrefetchWriteNode : public Node {
+public:
+  PrefetchWriteNode(Node *abio, Node *adr) : Node(0,abio,adr) {}
+  virtual int Opcode() const;
+  virtual uint ideal_reg() const { return NotAMachineReg; }
+  virtual uint match_edge(uint idx) const { return idx==2; }
+  virtual const Type *bottom_type() const { return Type::ABIO; }
+};