1 /*
   2  * Copyright (c) 1997, 2015, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_VM_OPTO_MEMNODE_HPP
  26 #define SHARE_VM_OPTO_MEMNODE_HPP
  27 
  28 #include "opto/multnode.hpp"
  29 #include "opto/node.hpp"
  30 #include "opto/opcodes.hpp"
  31 #include "opto/type.hpp"
  32 
  33 // Portions of code courtesy of Clifford Click
  34 
  35 class MultiNode;
  36 class PhaseCCP;
  37 class PhaseTransform;
  38 
  39 //------------------------------MemNode----------------------------------------
  40 // Load or Store, possibly throwing a NULL pointer exception
  41 class MemNode : public Node {
  42 private:
  43   bool _unaligned_access; // Unaligned access from unsafe
  44   bool _mismatched_access; // Mismatched access from unsafe: byte read in integer array for instance
  45 protected:
  46 #ifdef ASSERT
  47   const TypePtr* _adr_type;     // What kind of memory is being addressed?
  48 #endif
  49   virtual uint size_of() const;
  50 public:
  51   enum { Control,               // When is it safe to do this load?
  52          Memory,                // Chunk of memory is being loaded from
  53          Address,               // Actually address, derived from base
  54          ValueIn,               // Value to store
  55          OopStore               // Preceeding oop store, only in StoreCM
  56   };
  57   typedef enum { unordered = 0,
  58                  acquire,       // Load has to acquire or be succeeded by MemBarAcquire.
  59                  release        // Store has to release or be preceded by MemBarRelease.
  60   } MemOrd;
  61 protected:
  62   MemNode( Node *c0, Node *c1, Node *c2, const TypePtr* at )
  63     : Node(c0,c1,c2   ), _unaligned_access(false), _mismatched_access(false) {
  64     init_class_id(Class_Mem);
  65     debug_only(_adr_type=at; adr_type();)
  66   }
  67   MemNode( Node *c0, Node *c1, Node *c2, const TypePtr* at, Node *c3 )
  68     : Node(c0,c1,c2,c3), _unaligned_access(false), _mismatched_access(false) {
  69     init_class_id(Class_Mem);
  70     debug_only(_adr_type=at; adr_type();)
  71   }
  72   MemNode( Node *c0, Node *c1, Node *c2, const TypePtr* at, Node *c3, Node *c4)
  73     : Node(c0,c1,c2,c3,c4), _unaligned_access(false), _mismatched_access(false) {
  74     init_class_id(Class_Mem);
  75     debug_only(_adr_type=at; adr_type();)
  76   }
  77 
  78   virtual Node* find_previous_arraycopy(PhaseTransform* phase, Node* ld_alloc, Node*& mem, bool can_see_stored_value) const { return NULL; }
  79 
  80 public:
  81   // Helpers for the optimizer.  Documented in memnode.cpp.
  82   static bool detect_ptr_independence(Node* p1, AllocateNode* a1,
  83                                       Node* p2, AllocateNode* a2,
  84                                       PhaseTransform* phase);
  85   static bool adr_phi_is_loop_invariant(Node* adr_phi, Node* cast);
  86 
  87   static Node *optimize_simple_memory_chain(Node *mchain, const TypeOopPtr *t_oop, Node *load, PhaseGVN *phase);
  88   static Node *optimize_memory_chain(Node *mchain, const TypePtr *t_adr, Node *load, PhaseGVN *phase);
  89   // This one should probably be a phase-specific function:
  90   static bool all_controls_dominate(Node* dom, Node* sub);
  91 
  92   virtual const class TypePtr *adr_type() const;  // returns bottom_type of address
  93 
  94   // Shared code for Ideal methods:
  95   Node *Ideal_common(PhaseGVN *phase, bool can_reshape);  // Return -1 for short-circuit NULL.
  96 
  97   // Helper function for adr_type() implementations.
  98   static const TypePtr* calculate_adr_type(const Type* t, const TypePtr* cross_check = NULL);
  99 
 100   // Raw access function, to allow copying of adr_type efficiently in
 101   // product builds and retain the debug info for debug builds.
 102   const TypePtr *raw_adr_type() const {
 103 #ifdef ASSERT
 104     return _adr_type;
 105 #else
 106     return 0;
 107 #endif
 108   }
 109 
 110   // Map a load or store opcode to its corresponding store opcode.
 111   // (Return -1 if unknown.)
 112   virtual int store_Opcode() const { return -1; }
 113 
 114   // What is the type of the value in memory?  (T_VOID mean "unspecified".)
 115   virtual BasicType memory_type() const = 0;
 116   virtual int memory_size() const {
 117 #ifdef ASSERT
 118     return type2aelembytes(memory_type(), true);
 119 #else
 120     return type2aelembytes(memory_type());
 121 #endif
 122   }
 123 
 124   // Search through memory states which precede this node (load or store).
 125   // Look for an exact match for the address, with no intervening
 126   // aliased stores.
 127   Node* find_previous_store(PhaseTransform* phase);
 128 
 129   // Can this node (load or store) accurately see a stored value in
 130   // the given memory state?  (The state may or may not be in(Memory).)
 131   Node* can_see_stored_value(Node* st, PhaseTransform* phase) const;
 132 
 133   void set_unaligned_access() { _unaligned_access = true; }
 134   bool is_unaligned_access() const { return _unaligned_access; }
 135   void set_mismatched_access() { _mismatched_access = true; }
 136   bool is_mismatched_access() const { return _mismatched_access; }
 137 
 138 #ifndef PRODUCT
 139   static void dump_adr_type(const Node* mem, const TypePtr* adr_type, outputStream *st);
 140   virtual void dump_spec(outputStream *st) const;
 141 #endif
 142 };
 143 
 144 //------------------------------LoadNode---------------------------------------
 145 // Load value; requires Memory and Address
 146 class LoadNode : public MemNode {
 147 public:
 148   // Some loads (from unsafe) should be pinned: they don't depend only
 149   // on the dominating test.  The boolean field _depends_only_on_test
 150   // below records whether that node depends only on the dominating
 151   // test.
 152   // Methods used to build LoadNodes pass an argument of type enum
 153   // ControlDependency instead of a boolean because those methods
 154   // typically have multiple boolean parameters with default values:
 155   // passing the wrong boolean to one of these parameters by mistake
 156   // goes easily unnoticed. Using an enum, the compiler can check that
 157   // the type of a value and the type of the parameter match.
 158   enum ControlDependency {
 159     Pinned,
 160     DependsOnlyOnTest
 161   };
 162 private:
 163   // LoadNode::hash() doesn't take the _depends_only_on_test field
 164   // into account: If the graph already has a non-pinned LoadNode and
 165   // we add a pinned LoadNode with the same inputs, it's safe for GVN
 166   // to replace the pinned LoadNode with the non-pinned LoadNode,
 167   // otherwise it wouldn't be safe to have a non pinned LoadNode with
 168   // those inputs in the first place. If the graph already has a
 169   // pinned LoadNode and we add a non pinned LoadNode with the same
 170   // inputs, it's safe (but suboptimal) for GVN to replace the
 171   // non-pinned LoadNode by the pinned LoadNode.
 172   bool _depends_only_on_test;
 173 
 174   // On platforms with weak memory ordering (e.g., PPC, Ia64) we distinguish
 175   // loads that can be reordered, and such requiring acquire semantics to
 176   // adhere to the Java specification.  The required behaviour is stored in
 177   // this field.
 178   const MemOrd _mo;
 179 
 180 protected:
 181   virtual uint cmp(const Node &n) const;
 182   virtual uint size_of() const; // Size is bigger
 183   // Should LoadNode::Ideal() attempt to remove control edges?
 184   virtual bool can_remove_control() const;
 185   const Type* const _type;      // What kind of value is loaded?
 186 
 187   virtual Node* find_previous_arraycopy(PhaseTransform* phase, Node* ld_alloc, Node*& mem, bool can_see_stored_value) const;
 188 public:
 189 
 190   LoadNode(Node *c, Node *mem, Node *adr, const TypePtr* at, const Type *rt, MemOrd mo, ControlDependency control_dependency)
 191     : MemNode(c,mem,adr,at), _type(rt), _mo(mo), _depends_only_on_test(control_dependency == DependsOnlyOnTest) {
 192     init_class_id(Class_Load);
 193   }
 194   inline bool is_unordered() const { return !is_acquire(); }
 195   inline bool is_acquire() const {
 196     assert(_mo == unordered || _mo == acquire, "unexpected");
 197     return _mo == acquire;
 198   }
 199 
 200   // Polymorphic factory method:
 201   static Node* make(PhaseGVN& gvn, Node *c, Node *mem, Node *adr,
 202                     const TypePtr* at, const Type *rt, BasicType bt,
 203                     MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest,
 204                     bool unaligned = false, bool mismatched = false);
 205 
 206   virtual uint hash()   const;  // Check the type
 207 
 208   // Handle algebraic identities here.  If we have an identity, return the Node
 209   // we are equivalent to.  We look for Load of a Store.
 210   virtual Node *Identity( PhaseTransform *phase );
 211 
 212   // If the load is from Field memory and the pointer is non-null, it might be possible to
 213   // zero out the control input.
 214   // If the offset is constant and the base is an object allocation,
 215   // try to hook me up to the exact initializing store.
 216   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
 217 
 218   // Split instance field load through Phi.
 219   Node* split_through_phi(PhaseGVN *phase);
 220 
 221   // Recover original value from boxed values
 222   Node *eliminate_autobox(PhaseGVN *phase);
 223 
 224   // Compute a new Type for this node.  Basically we just do the pre-check,
 225   // then call the virtual add() to set the type.
 226   virtual const Type *Value( PhaseTransform *phase ) const;
 227 
 228   // Common methods for LoadKlass and LoadNKlass nodes.
 229   const Type *klass_value_common( PhaseTransform *phase ) const;
 230   Node *klass_identity_common( PhaseTransform *phase );
 231 
 232   virtual uint ideal_reg() const;
 233   virtual const Type *bottom_type() const;
 234   // Following method is copied from TypeNode:
 235   void set_type(const Type* t) {
 236     assert(t != NULL, "sanity");
 237     debug_only(uint check_hash = (VerifyHashTableKeys && _hash_lock) ? hash() : NO_HASH);
 238     *(const Type**)&_type = t;   // cast away const-ness
 239     // If this node is in the hash table, make sure it doesn't need a rehash.
 240     assert(check_hash == NO_HASH || check_hash == hash(), "type change must preserve hash code");
 241   }
 242   const Type* type() const { assert(_type != NULL, "sanity"); return _type; };
 243 
 244   // Do not match memory edge
 245   virtual uint match_edge(uint idx) const;
 246 
 247   // Map a load opcode to its corresponding store opcode.
 248   virtual int store_Opcode() const = 0;
 249 
 250   // Check if the load's memory input is a Phi node with the same control.
 251   bool is_instance_field_load_with_local_phi(Node* ctrl);
 252 
 253 #ifndef PRODUCT
 254   virtual void dump_spec(outputStream *st) const;
 255 #endif
 256 #ifdef ASSERT
 257   // Helper function to allow a raw load without control edge for some cases
 258   static bool is_immutable_value(Node* adr);
 259 #endif
 260 protected:
 261   const Type* load_array_final_field(const TypeKlassPtr *tkls,
 262                                      ciKlass* klass) const;
 263 
 264   Node* can_see_arraycopy_value(Node* st, PhaseTransform* phase) const;
 265 
 266   // depends_only_on_test is almost always true, and needs to be almost always
 267   // true to enable key hoisting & commoning optimizations.  However, for the
 268   // special case of RawPtr loads from TLS top & end, and other loads performed by
 269   // GC barriers, the control edge carries the dependence preventing hoisting past
 270   // a Safepoint instead of the memory edge.  (An unfortunate consequence of having
 271   // Safepoints not set Raw Memory; itself an unfortunate consequence of having Nodes
 272   // which produce results (new raw memory state) inside of loops preventing all
 273   // manner of other optimizations).  Basically, it's ugly but so is the alternative.
 274   // See comment in macro.cpp, around line 125 expand_allocate_common().
 275   virtual bool depends_only_on_test() const { return adr_type() != TypeRawPtr::BOTTOM && _depends_only_on_test; }
 276 };
 277 
 278 //------------------------------LoadBNode--------------------------------------
 279 // Load a byte (8bits signed) from memory
 280 class LoadBNode : public LoadNode {
 281 public:
 282   LoadBNode(Node *c, Node *mem, Node *adr, const TypePtr* at, const TypeInt *ti, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
 283     : LoadNode(c, mem, adr, at, ti, mo, control_dependency) {}
 284   virtual int Opcode() const;
 285   virtual uint ideal_reg() const { return Op_RegI; }
 286   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
 287   virtual const Type *Value(PhaseTransform *phase) const;
 288   virtual int store_Opcode() const { return Op_StoreB; }
 289   virtual BasicType memory_type() const { return T_BYTE; }
 290 };
 291 
 292 //------------------------------LoadUBNode-------------------------------------
 293 // Load a unsigned byte (8bits unsigned) from memory
 294 class LoadUBNode : public LoadNode {
 295 public:
 296   LoadUBNode(Node* c, Node* mem, Node* adr, const TypePtr* at, const TypeInt* ti, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
 297     : LoadNode(c, mem, adr, at, ti, mo, control_dependency) {}
 298   virtual int Opcode() const;
 299   virtual uint ideal_reg() const { return Op_RegI; }
 300   virtual Node* Ideal(PhaseGVN *phase, bool can_reshape);
 301   virtual const Type *Value(PhaseTransform *phase) const;
 302   virtual int store_Opcode() const { return Op_StoreB; }
 303   virtual BasicType memory_type() const { return T_BYTE; }
 304 };
 305 
 306 //------------------------------LoadUSNode-------------------------------------
 307 // Load an unsigned short/char (16bits unsigned) from memory
 308 class LoadUSNode : public LoadNode {
 309 public:
 310   LoadUSNode(Node *c, Node *mem, Node *adr, const TypePtr* at, const TypeInt *ti, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
 311     : LoadNode(c, mem, adr, at, ti, mo, control_dependency) {}
 312   virtual int Opcode() const;
 313   virtual uint ideal_reg() const { return Op_RegI; }
 314   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
 315   virtual const Type *Value(PhaseTransform *phase) const;
 316   virtual int store_Opcode() const { return Op_StoreC; }
 317   virtual BasicType memory_type() const { return T_CHAR; }
 318 };
 319 
 320 //------------------------------LoadSNode--------------------------------------
 321 // Load a short (16bits signed) from memory
 322 class LoadSNode : public LoadNode {
 323 public:
 324   LoadSNode(Node *c, Node *mem, Node *adr, const TypePtr* at, const TypeInt *ti, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
 325     : LoadNode(c, mem, adr, at, ti, mo, control_dependency) {}
 326   virtual int Opcode() const;
 327   virtual uint ideal_reg() const { return Op_RegI; }
 328   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
 329   virtual const Type *Value(PhaseTransform *phase) const;
 330   virtual int store_Opcode() const { return Op_StoreC; }
 331   virtual BasicType memory_type() const { return T_SHORT; }
 332 };
 333 
 334 //------------------------------LoadINode--------------------------------------
 335 // Load an integer from memory
 336 class LoadINode : public LoadNode {
 337 public:
 338   LoadINode(Node *c, Node *mem, Node *adr, const TypePtr* at, const TypeInt *ti, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
 339     : LoadNode(c, mem, adr, at, ti, mo, control_dependency) {}
 340   virtual int Opcode() const;
 341   virtual uint ideal_reg() const { return Op_RegI; }
 342   virtual int store_Opcode() const { return Op_StoreI; }
 343   virtual BasicType memory_type() const { return T_INT; }
 344 };
 345 
 346 //------------------------------LoadRangeNode----------------------------------
 347 // Load an array length from the array
 348 class LoadRangeNode : public LoadINode {
 349 public:
 350   LoadRangeNode(Node *c, Node *mem, Node *adr, const TypeInt *ti = TypeInt::POS)
 351     : LoadINode(c, mem, adr, TypeAryPtr::RANGE, ti, MemNode::unordered) {}
 352   virtual int Opcode() const;
 353   virtual const Type *Value( PhaseTransform *phase ) const;
 354   virtual Node *Identity( PhaseTransform *phase );
 355   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
 356 };
 357 
 358 //------------------------------LoadLNode--------------------------------------
 359 // Load a long from memory
 360 class LoadLNode : public LoadNode {
 361   virtual uint hash() const { return LoadNode::hash() + _require_atomic_access; }
 362   virtual uint cmp( const Node &n ) const {
 363     return _require_atomic_access == ((LoadLNode&)n)._require_atomic_access
 364       && LoadNode::cmp(n);
 365   }
 366   virtual uint size_of() const { return sizeof(*this); }
 367   const bool _require_atomic_access;  // is piecewise load forbidden?
 368 
 369 public:
 370   LoadLNode(Node *c, Node *mem, Node *adr, const TypePtr* at, const TypeLong *tl,
 371             MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest, bool require_atomic_access = false)
 372     : LoadNode(c, mem, adr, at, tl, mo, control_dependency), _require_atomic_access(require_atomic_access) {}
 373   virtual int Opcode() const;
 374   virtual uint ideal_reg() const { return Op_RegL; }
 375   virtual int store_Opcode() const { return Op_StoreL; }
 376   virtual BasicType memory_type() const { return T_LONG; }
 377   bool require_atomic_access() const { return _require_atomic_access; }
 378   static LoadLNode* make_atomic(Node* ctl, Node* mem, Node* adr, const TypePtr* adr_type,
 379                                 const Type* rt, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest,
 380                                 bool unaligned = false, bool mismatched = false);
 381 #ifndef PRODUCT
 382   virtual void dump_spec(outputStream *st) const {
 383     LoadNode::dump_spec(st);
 384     if (_require_atomic_access)  st->print(" Atomic!");
 385   }
 386 #endif
 387 };
 388 
 389 //------------------------------LoadL_unalignedNode----------------------------
 390 // Load a long from unaligned memory
 391 class LoadL_unalignedNode : public LoadLNode {
 392 public:
 393   LoadL_unalignedNode(Node *c, Node *mem, Node *adr, const TypePtr* at, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
 394     : LoadLNode(c, mem, adr, at, TypeLong::LONG, mo, control_dependency) {}
 395   virtual int Opcode() const;
 396 };
 397 
 398 //------------------------------LoadFNode--------------------------------------
 399 // Load a float (64 bits) from memory
 400 class LoadFNode : public LoadNode {
 401 public:
 402   LoadFNode(Node *c, Node *mem, Node *adr, const TypePtr* at, const Type *t, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
 403     : LoadNode(c, mem, adr, at, t, mo, control_dependency) {}
 404   virtual int Opcode() const;
 405   virtual uint ideal_reg() const { return Op_RegF; }
 406   virtual int store_Opcode() const { return Op_StoreF; }
 407   virtual BasicType memory_type() const { return T_FLOAT; }
 408 };
 409 
 410 //------------------------------LoadDNode--------------------------------------
 411 // Load a double (64 bits) from memory
 412 class LoadDNode : public LoadNode {
 413   virtual uint hash() const { return LoadNode::hash() + _require_atomic_access; }
 414   virtual uint cmp( const Node &n ) const {
 415     return _require_atomic_access == ((LoadDNode&)n)._require_atomic_access
 416       && LoadNode::cmp(n);
 417   }
 418   virtual uint size_of() const { return sizeof(*this); }
 419   const bool _require_atomic_access;  // is piecewise load forbidden?
 420 
 421 public:
 422   LoadDNode(Node *c, Node *mem, Node *adr, const TypePtr* at, const Type *t,
 423             MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest, bool require_atomic_access = false)
 424     : LoadNode(c, mem, adr, at, t, mo, control_dependency), _require_atomic_access(require_atomic_access) {}
 425   virtual int Opcode() const;
 426   virtual uint ideal_reg() const { return Op_RegD; }
 427   virtual int store_Opcode() const { return Op_StoreD; }
 428   virtual BasicType memory_type() const { return T_DOUBLE; }
 429   bool require_atomic_access() const { return _require_atomic_access; }
 430   static LoadDNode* make_atomic(Node* ctl, Node* mem, Node* adr, const TypePtr* adr_type,
 431                                 const Type* rt, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest,
 432                                 bool unaligned = false, bool mismatched = false);
 433 #ifndef PRODUCT
 434   virtual void dump_spec(outputStream *st) const {
 435     LoadNode::dump_spec(st);
 436     if (_require_atomic_access)  st->print(" Atomic!");
 437   }
 438 #endif
 439 };
 440 
 441 //------------------------------LoadD_unalignedNode----------------------------
 442 // Load a double from unaligned memory
 443 class LoadD_unalignedNode : public LoadDNode {
 444 public:
 445   LoadD_unalignedNode(Node *c, Node *mem, Node *adr, const TypePtr* at, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
 446     : LoadDNode(c, mem, adr, at, Type::DOUBLE, mo, control_dependency) {}
 447   virtual int Opcode() const;
 448 };
 449 
 450 //------------------------------LoadPNode--------------------------------------
 451 // Load a pointer from memory (either object or array)
 452 class LoadPNode : public LoadNode {
 453 public:
 454   LoadPNode(Node *c, Node *mem, Node *adr, const TypePtr *at, const TypePtr* t, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
 455     : LoadNode(c, mem, adr, at, t, mo, control_dependency) {}
 456   virtual int Opcode() const;
 457   virtual uint ideal_reg() const { return Op_RegP; }
 458   virtual int store_Opcode() const { return Op_StoreP; }
 459   virtual BasicType memory_type() const { return T_ADDRESS; }
 460 };
 461 
 462 
 463 //------------------------------LoadNNode--------------------------------------
 464 // Load a narrow oop from memory (either object or array)
 465 class LoadNNode : public LoadNode {
 466 public:
 467   LoadNNode(Node *c, Node *mem, Node *adr, const TypePtr *at, const Type* t, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
 468     : LoadNode(c, mem, adr, at, t, mo, control_dependency) {}
 469   virtual int Opcode() const;
 470   virtual uint ideal_reg() const { return Op_RegN; }
 471   virtual int store_Opcode() const { return Op_StoreN; }
 472   virtual BasicType memory_type() const { return T_NARROWOOP; }
 473 };
 474 
 475 //------------------------------LoadKlassNode----------------------------------
 476 // Load a Klass from an object
 477 class LoadKlassNode : public LoadPNode {
 478 protected:
 479   // In most cases, LoadKlassNode does not have the control input set. If the control
 480   // input is set, it must not be removed (by LoadNode::Ideal()).
 481   virtual bool can_remove_control() const;
 482 public:
 483   LoadKlassNode(Node *c, Node *mem, Node *adr, const TypePtr *at, const TypeKlassPtr *tk, MemOrd mo)
 484     : LoadPNode(c, mem, adr, at, tk, mo) {}
 485   virtual int Opcode() const;
 486   virtual const Type *Value( PhaseTransform *phase ) const;
 487   virtual Node *Identity( PhaseTransform *phase );
 488   virtual bool depends_only_on_test() const { return true; }
 489 
 490   // Polymorphic factory method:
 491   static Node* make(PhaseGVN& gvn, Node* ctl, Node* mem, Node* adr, const TypePtr* at,
 492                     const TypeKlassPtr* tk = TypeKlassPtr::OBJECT);
 493 };
 494 
 495 //------------------------------LoadNKlassNode---------------------------------
 496 // Load a narrow Klass from an object.
 497 class LoadNKlassNode : public LoadNNode {
 498 public:
 499   LoadNKlassNode(Node *c, Node *mem, Node *adr, const TypePtr *at, const TypeNarrowKlass *tk, MemOrd mo)
 500     : LoadNNode(c, mem, adr, at, tk, mo) {}
 501   virtual int Opcode() const;
 502   virtual uint ideal_reg() const { return Op_RegN; }
 503   virtual int store_Opcode() const { return Op_StoreNKlass; }
 504   virtual BasicType memory_type() const { return T_NARROWKLASS; }
 505 
 506   virtual const Type *Value( PhaseTransform *phase ) const;
 507   virtual Node *Identity( PhaseTransform *phase );
 508   virtual bool depends_only_on_test() const { return true; }
 509 };
 510 
 511 
 512 //------------------------------StoreNode--------------------------------------
 513 // Store value; requires Store, Address and Value
 514 class StoreNode : public MemNode {
 515 private:
 516   // On platforms with weak memory ordering (e.g., PPC, Ia64) we distinguish
 517   // stores that can be reordered, and such requiring release semantics to
 518   // adhere to the Java specification.  The required behaviour is stored in
 519   // this field.
 520   const MemOrd _mo;
 521   // Needed for proper cloning.
 522   virtual uint size_of() const { return sizeof(*this); }
 523 protected:
 524   virtual uint cmp( const Node &n ) const;
 525   virtual bool depends_only_on_test() const { return false; }
 526 
 527   Node *Ideal_masked_input       (PhaseGVN *phase, uint mask);
 528   Node *Ideal_sign_extended_input(PhaseGVN *phase, int  num_bits);
 529 
 530 public:
 531   // We must ensure that stores of object references will be visible
 532   // only after the object's initialization. So the callers of this
 533   // procedure must indicate that the store requires `release'
 534   // semantics, if the stored value is an object reference that might
 535   // point to a new object and may become externally visible.
 536   StoreNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, MemOrd mo)
 537     : MemNode(c, mem, adr, at, val), _mo(mo) {
 538     init_class_id(Class_Store);
 539   }
 540   StoreNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, Node *oop_store, MemOrd mo)
 541     : MemNode(c, mem, adr, at, val, oop_store), _mo(mo) {
 542     init_class_id(Class_Store);
 543   }
 544 
 545   inline bool is_unordered() const { return !is_release(); }
 546   inline bool is_release() const {
 547     assert((_mo == unordered || _mo == release), "unexpected");
 548     return _mo == release;
 549   }
 550 
 551   // Conservatively release stores of object references in order to
 552   // ensure visibility of object initialization.
 553   static inline MemOrd release_if_reference(const BasicType t) {
 554 #ifdef AARCH64
 555     // AArch64 doesn't need a release store here because object
 556     // initialization contains the necessary barriers.
 557     return unordered;
 558 #else
 559     const MemOrd mo = (t == T_ARRAY ||
 560                        t == T_ADDRESS || // Might be the address of an object reference (`boxing').
 561                        t == T_OBJECT) ? release : unordered;
 562     return mo;
 563 #endif
 564   }
 565 
 566   // Polymorphic factory method
 567   //
 568   // We must ensure that stores of object references will be visible
 569   // only after the object's initialization. So the callers of this
 570   // procedure must indicate that the store requires `release'
 571   // semantics, if the stored value is an object reference that might
 572   // point to a new object and may become externally visible.
 573   static StoreNode* make(PhaseGVN& gvn, Node *c, Node *mem, Node *adr,
 574                          const TypePtr* at, Node *val, BasicType bt, MemOrd mo);
 575 
 576   virtual uint hash() const;    // Check the type
 577 
 578   // If the store is to Field memory and the pointer is non-null, we can
 579   // zero out the control input.
 580   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
 581 
 582   // Compute a new Type for this node.  Basically we just do the pre-check,
 583   // then call the virtual add() to set the type.
 584   virtual const Type *Value( PhaseTransform *phase ) const;
 585 
 586   // Check for identity function on memory (Load then Store at same address)
 587   virtual Node *Identity( PhaseTransform *phase );
 588 
 589   // Do not match memory edge
 590   virtual uint match_edge(uint idx) const;
 591 
 592   virtual const Type *bottom_type() const;  // returns Type::MEMORY
 593 
 594   // Map a store opcode to its corresponding own opcode, trivially.
 595   virtual int store_Opcode() const { return Opcode(); }
 596 
 597   // have all possible loads of the value stored been optimized away?
 598   bool value_never_loaded(PhaseTransform *phase) const;
 599 };
 600 
 601 //------------------------------StoreBNode-------------------------------------
 602 // Store byte to memory
 603 class StoreBNode : public StoreNode {
 604 public:
 605   StoreBNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, MemOrd mo)
 606     : StoreNode(c, mem, adr, at, val, mo) {}
 607   virtual int Opcode() const;
 608   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
 609   virtual BasicType memory_type() const { return T_BYTE; }
 610 };
 611 
 612 //------------------------------StoreCNode-------------------------------------
 613 // Store char/short to memory
 614 class StoreCNode : public StoreNode {
 615 public:
 616   StoreCNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, MemOrd mo)
 617     : StoreNode(c, mem, adr, at, val, mo) {}
 618   virtual int Opcode() const;
 619   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
 620   virtual BasicType memory_type() const { return T_CHAR; }
 621 };
 622 
 623 //------------------------------StoreINode-------------------------------------
 624 // Store int to memory
 625 class StoreINode : public StoreNode {
 626 public:
 627   StoreINode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, MemOrd mo)
 628     : StoreNode(c, mem, adr, at, val, mo) {}
 629   virtual int Opcode() const;
 630   virtual BasicType memory_type() const { return T_INT; }
 631 };
 632 
 633 //------------------------------StoreLNode-------------------------------------
 634 // Store long to memory
 635 class StoreLNode : public StoreNode {
 636   virtual uint hash() const { return StoreNode::hash() + _require_atomic_access; }
 637   virtual uint cmp( const Node &n ) const {
 638     return _require_atomic_access == ((StoreLNode&)n)._require_atomic_access
 639       && StoreNode::cmp(n);
 640   }
 641   virtual uint size_of() const { return sizeof(*this); }
 642   const bool _require_atomic_access;  // is piecewise store forbidden?
 643 
 644 public:
 645   StoreLNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, MemOrd mo, bool require_atomic_access = false)
 646     : StoreNode(c, mem, adr, at, val, mo), _require_atomic_access(require_atomic_access) {}
 647   virtual int Opcode() const;
 648   virtual BasicType memory_type() const { return T_LONG; }
 649   bool require_atomic_access() const { return _require_atomic_access; }
 650   static StoreLNode* make_atomic(Node* ctl, Node* mem, Node* adr, const TypePtr* adr_type, Node* val, MemOrd mo);
 651 #ifndef PRODUCT
 652   virtual void dump_spec(outputStream *st) const {
 653     StoreNode::dump_spec(st);
 654     if (_require_atomic_access)  st->print(" Atomic!");
 655   }
 656 #endif
 657 };
 658 
 659 //------------------------------StoreFNode-------------------------------------
 660 // Store float to memory
 661 class StoreFNode : public StoreNode {
 662 public:
 663   StoreFNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, MemOrd mo)
 664     : StoreNode(c, mem, adr, at, val, mo) {}
 665   virtual int Opcode() const;
 666   virtual BasicType memory_type() const { return T_FLOAT; }
 667 };
 668 
 669 //------------------------------StoreDNode-------------------------------------
 670 // Store double to memory
 671 class StoreDNode : public StoreNode {
 672   virtual uint hash() const { return StoreNode::hash() + _require_atomic_access; }
 673   virtual uint cmp( const Node &n ) const {
 674     return _require_atomic_access == ((StoreDNode&)n)._require_atomic_access
 675       && StoreNode::cmp(n);
 676   }
 677   virtual uint size_of() const { return sizeof(*this); }
 678   const bool _require_atomic_access;  // is piecewise store forbidden?
 679 public:
 680   StoreDNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val,
 681              MemOrd mo, bool require_atomic_access = false)
 682     : StoreNode(c, mem, adr, at, val, mo), _require_atomic_access(require_atomic_access) {}
 683   virtual int Opcode() const;
 684   virtual BasicType memory_type() const { return T_DOUBLE; }
 685   bool require_atomic_access() const { return _require_atomic_access; }
 686   static StoreDNode* make_atomic(Node* ctl, Node* mem, Node* adr, const TypePtr* adr_type, Node* val, MemOrd mo);
 687 #ifndef PRODUCT
 688   virtual void dump_spec(outputStream *st) const {
 689     StoreNode::dump_spec(st);
 690     if (_require_atomic_access)  st->print(" Atomic!");
 691   }
 692 #endif
 693 
 694 };
 695 
 696 //------------------------------StorePNode-------------------------------------
 697 // Store pointer to memory
 698 class StorePNode : public StoreNode {
 699 public:
 700   StorePNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, MemOrd mo)
 701     : StoreNode(c, mem, adr, at, val, mo) {}
 702   virtual int Opcode() const;
 703   virtual BasicType memory_type() const { return T_ADDRESS; }
 704 };
 705 
 706 //------------------------------StoreNNode-------------------------------------
 707 // Store narrow oop to memory
 708 class StoreNNode : public StoreNode {
 709 public:
 710   StoreNNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, MemOrd mo)
 711     : StoreNode(c, mem, adr, at, val, mo) {}
 712   virtual int Opcode() const;
 713   virtual BasicType memory_type() const { return T_NARROWOOP; }
 714 };
 715 
 716 //------------------------------StoreNKlassNode--------------------------------------
 717 // Store narrow klass to memory
 718 class StoreNKlassNode : public StoreNNode {
 719 public:
 720   StoreNKlassNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, MemOrd mo)
 721     : StoreNNode(c, mem, adr, at, val, mo) {}
 722   virtual int Opcode() const;
 723   virtual BasicType memory_type() const { return T_NARROWKLASS; }
 724 };
 725 
 726 //------------------------------StoreCMNode-----------------------------------
 727 // Store card-mark byte to memory for CM
 728 // The last StoreCM before a SafePoint must be preserved and occur after its "oop" store
 729 // Preceeding equivalent StoreCMs may be eliminated.
 730 class StoreCMNode : public StoreNode {
 731  private:
 732   virtual uint hash() const { return StoreNode::hash() + _oop_alias_idx; }
 733   virtual uint cmp( const Node &n ) const {
 734     return _oop_alias_idx == ((StoreCMNode&)n)._oop_alias_idx
 735       && StoreNode::cmp(n);
 736   }
 737   virtual uint size_of() const { return sizeof(*this); }
 738   int _oop_alias_idx;   // The alias_idx of OopStore
 739 
 740 public:
 741   StoreCMNode( Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, Node *oop_store, int oop_alias_idx ) :
 742     StoreNode(c, mem, adr, at, val, oop_store, MemNode::release),
 743     _oop_alias_idx(oop_alias_idx) {
 744     assert(_oop_alias_idx >= Compile::AliasIdxRaw ||
 745            _oop_alias_idx == Compile::AliasIdxBot && Compile::current()->AliasLevel() == 0,
 746            "bad oop alias idx");
 747   }
 748   virtual int Opcode() const;
 749   virtual Node *Identity( PhaseTransform *phase );
 750   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
 751   virtual const Type *Value( PhaseTransform *phase ) const;
 752   virtual BasicType memory_type() const { return T_VOID; } // unspecific
 753   int oop_alias_idx() const { return _oop_alias_idx; }
 754 };
 755 
 756 //------------------------------LoadPLockedNode---------------------------------
 757 // Load-locked a pointer from memory (either object or array).
 758 // On Sparc & Intel this is implemented as a normal pointer load.
 759 // On PowerPC and friends it's a real load-locked.
 760 class LoadPLockedNode : public LoadPNode {
 761 public:
 762   LoadPLockedNode(Node *c, Node *mem, Node *adr, MemOrd mo)
 763     : LoadPNode(c, mem, adr, TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM, mo) {}
 764   virtual int Opcode() const;
 765   virtual int store_Opcode() const { return Op_StorePConditional; }
 766   virtual bool depends_only_on_test() const { return true; }
 767 };
 768 
 769 //------------------------------SCMemProjNode---------------------------------------
 770 // This class defines a projection of the memory  state of a store conditional node.
 771 // These nodes return a value, but also update memory.
 772 class SCMemProjNode : public ProjNode {
 773 public:
 774   enum {SCMEMPROJCON = (uint)-2};
 775   SCMemProjNode( Node *src) : ProjNode( src, SCMEMPROJCON) { }
 776   virtual int Opcode() const;
 777   virtual bool      is_CFG() const  { return false; }
 778   virtual const Type *bottom_type() const {return Type::MEMORY;}
 779   virtual const TypePtr *adr_type() const {
 780     Node* ctrl = in(0);
 781     if (ctrl == NULL)  return NULL; // node is dead
 782     return ctrl->in(MemNode::Memory)->adr_type();
 783   }
 784   virtual uint ideal_reg() const { return 0;} // memory projections don't have a register
 785   virtual const Type *Value( PhaseTransform *phase ) const;
 786 #ifndef PRODUCT
 787   virtual void dump_spec(outputStream *st) const {};
 788 #endif
 789 };
 790 
 791 //------------------------------LoadStoreNode---------------------------
 792 // Note: is_Mem() method returns 'true' for this class.
 793 class LoadStoreNode : public Node {
 794 private:
 795   const Type* const _type;      // What kind of value is loaded?
 796   const TypePtr* _adr_type;     // What kind of memory is being addressed?
 797   virtual uint size_of() const; // Size is bigger
 798 public:
 799   LoadStoreNode( Node *c, Node *mem, Node *adr, Node *val, const TypePtr* at, const Type* rt, uint required );
 800   virtual bool depends_only_on_test() const { return false; }
 801   virtual uint match_edge(uint idx) const { return idx == MemNode::Address || idx == MemNode::ValueIn; }
 802 
 803   virtual const Type *bottom_type() const { return _type; }
 804   virtual uint ideal_reg() const;
 805   virtual const class TypePtr *adr_type() const { return _adr_type; }  // returns bottom_type of address
 806 
 807   bool result_not_used() const;
 808 };
 809 
 810 class LoadStoreConditionalNode : public LoadStoreNode {
 811 public:
 812   enum {
 813     ExpectedIn = MemNode::ValueIn+1 // One more input than MemNode
 814   };
 815   LoadStoreConditionalNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex);
 816 };
 817 
 818 //------------------------------StorePConditionalNode---------------------------
 819 // Conditionally store pointer to memory, if no change since prior
 820 // load-locked.  Sets flags for success or failure of the store.
 821 class StorePConditionalNode : public LoadStoreConditionalNode {
 822 public:
 823   StorePConditionalNode( Node *c, Node *mem, Node *adr, Node *val, Node *ll ) : LoadStoreConditionalNode(c, mem, adr, val, ll) { }
 824   virtual int Opcode() const;
 825   // Produces flags
 826   virtual uint ideal_reg() const { return Op_RegFlags; }
 827 };
 828 
 829 //------------------------------StoreIConditionalNode---------------------------
 830 // Conditionally store int to memory, if no change since prior
 831 // load-locked.  Sets flags for success or failure of the store.
 832 class StoreIConditionalNode : public LoadStoreConditionalNode {
 833 public:
 834   StoreIConditionalNode( Node *c, Node *mem, Node *adr, Node *val, Node *ii ) : LoadStoreConditionalNode(c, mem, adr, val, ii) { }
 835   virtual int Opcode() const;
 836   // Produces flags
 837   virtual uint ideal_reg() const { return Op_RegFlags; }
 838 };
 839 
 840 //------------------------------StoreLConditionalNode---------------------------
 841 // Conditionally store long to memory, if no change since prior
 842 // load-locked.  Sets flags for success or failure of the store.
 843 class StoreLConditionalNode : public LoadStoreConditionalNode {
 844 public:
 845   StoreLConditionalNode( Node *c, Node *mem, Node *adr, Node *val, Node *ll ) : LoadStoreConditionalNode(c, mem, adr, val, ll) { }
 846   virtual int Opcode() const;
 847   // Produces flags
 848   virtual uint ideal_reg() const { return Op_RegFlags; }
 849 };
 850 
 851 
 852 //------------------------------CompareAndSwapLNode---------------------------
 853 class CompareAndSwapLNode : public LoadStoreConditionalNode {
 854 public:
 855   CompareAndSwapLNode( Node *c, Node *mem, Node *adr, Node *val, Node *ex) : LoadStoreConditionalNode(c, mem, adr, val, ex) { }
 856   virtual int Opcode() const;
 857 };
 858 
 859 
 860 //------------------------------CompareAndSwapINode---------------------------
 861 class CompareAndSwapINode : public LoadStoreConditionalNode {
 862 public:
 863   CompareAndSwapINode( Node *c, Node *mem, Node *adr, Node *val, Node *ex) : LoadStoreConditionalNode(c, mem, adr, val, ex) { }
 864   virtual int Opcode() const;
 865 };
 866 
 867 
 868 //------------------------------CompareAndSwapPNode---------------------------
 869 class CompareAndSwapPNode : public LoadStoreConditionalNode {
 870 public:
 871   CompareAndSwapPNode( Node *c, Node *mem, Node *adr, Node *val, Node *ex) : LoadStoreConditionalNode(c, mem, adr, val, ex) { }
 872   virtual int Opcode() const;
 873 };
 874 
 875 //------------------------------CompareAndSwapNNode---------------------------
 876 class CompareAndSwapNNode : public LoadStoreConditionalNode {
 877 public:
 878   CompareAndSwapNNode( Node *c, Node *mem, Node *adr, Node *val, Node *ex) : LoadStoreConditionalNode(c, mem, adr, val, ex) { }
 879   virtual int Opcode() const;
 880 };
 881 
 882 //------------------------------GetAndAddINode---------------------------
 883 class GetAndAddINode : public LoadStoreNode {
 884 public:
 885   GetAndAddINode( Node *c, Node *mem, Node *adr, Node *val, const TypePtr* at ) : LoadStoreNode(c, mem, adr, val, at, TypeInt::INT, 4) { }
 886   virtual int Opcode() const;
 887 };
 888 
 889 //------------------------------GetAndAddLNode---------------------------
 890 class GetAndAddLNode : public LoadStoreNode {
 891 public:
 892   GetAndAddLNode( Node *c, Node *mem, Node *adr, Node *val, const TypePtr* at ) : LoadStoreNode(c, mem, adr, val, at, TypeLong::LONG, 4) { }
 893   virtual int Opcode() const;
 894 };
 895 
 896 
 897 //------------------------------GetAndSetINode---------------------------
 898 class GetAndSetINode : public LoadStoreNode {
 899 public:
 900   GetAndSetINode( Node *c, Node *mem, Node *adr, Node *val, const TypePtr* at ) : LoadStoreNode(c, mem, adr, val, at, TypeInt::INT, 4) { }
 901   virtual int Opcode() const;
 902 };
 903 
 904 //------------------------------GetAndSetINode---------------------------
 905 class GetAndSetLNode : public LoadStoreNode {
 906 public:
 907   GetAndSetLNode( Node *c, Node *mem, Node *adr, Node *val, const TypePtr* at ) : LoadStoreNode(c, mem, adr, val, at, TypeLong::LONG, 4) { }
 908   virtual int Opcode() const;
 909 };
 910 
 911 //------------------------------GetAndSetPNode---------------------------
 912 class GetAndSetPNode : public LoadStoreNode {
 913 public:
 914   GetAndSetPNode( Node *c, Node *mem, Node *adr, Node *val, const TypePtr* at, const Type* t ) : LoadStoreNode(c, mem, adr, val, at, t, 4) { }
 915   virtual int Opcode() const;
 916 };
 917 
 918 //------------------------------GetAndSetNNode---------------------------
 919 class GetAndSetNNode : public LoadStoreNode {
 920 public:
 921   GetAndSetNNode( Node *c, Node *mem, Node *adr, Node *val, const TypePtr* at, const Type* t ) : LoadStoreNode(c, mem, adr, val, at, t, 4) { }
 922   virtual int Opcode() const;
 923 };
 924 
 925 //------------------------------ClearArray-------------------------------------
 926 class ClearArrayNode: public Node {
 927 public:
 928   ClearArrayNode( Node *ctrl, Node *arymem, Node *word_cnt, Node *base )
 929     : Node(ctrl,arymem,word_cnt,base) {
 930     init_class_id(Class_ClearArray);
 931   }
 932   virtual int         Opcode() const;
 933   virtual const Type *bottom_type() const { return Type::MEMORY; }
 934   // ClearArray modifies array elements, and so affects only the
 935   // array memory addressed by the bottom_type of its base address.
 936   virtual const class TypePtr *adr_type() const;
 937   virtual Node *Identity( PhaseTransform *phase );
 938   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
 939   virtual uint match_edge(uint idx) const;
 940 
 941   // Clear the given area of an object or array.
 942   // The start offset must always be aligned mod BytesPerInt.
 943   // The end offset must always be aligned mod BytesPerLong.
 944   // Return the new memory.
 945   static Node* clear_memory(Node* control, Node* mem, Node* dest,
 946                             intptr_t start_offset,
 947                             intptr_t end_offset,
 948                             PhaseGVN* phase);
 949   static Node* clear_memory(Node* control, Node* mem, Node* dest,
 950                             intptr_t start_offset,
 951                             Node* end_offset,
 952                             PhaseGVN* phase);
 953   static Node* clear_memory(Node* control, Node* mem, Node* dest,
 954                             Node* start_offset,
 955                             Node* end_offset,
 956                             PhaseGVN* phase);
 957   // Return allocation input memory edge if it is different instance
 958   // or itself if it is the one we are looking for.
 959   static bool step_through(Node** np, uint instance_id, PhaseTransform* phase);
 960 };
 961 
 962 //------------------------------MemBar-----------------------------------------
 963 // There are different flavors of Memory Barriers to match the Java Memory
 964 // Model.  Monitor-enter and volatile-load act as Aquires: no following ref
 965 // can be moved to before them.  We insert a MemBar-Acquire after a FastLock or
 966 // volatile-load.  Monitor-exit and volatile-store act as Release: no
 967 // preceding ref can be moved to after them.  We insert a MemBar-Release
 968 // before a FastUnlock or volatile-store.  All volatiles need to be
 969 // serialized, so we follow all volatile-stores with a MemBar-Volatile to
 970 // separate it from any following volatile-load.
 971 class MemBarNode: public MultiNode {
 972   virtual uint hash() const ;                  // { return NO_HASH; }
 973   virtual uint cmp( const Node &n ) const ;    // Always fail, except on self
 974 
 975   virtual uint size_of() const { return sizeof(*this); }
 976   // Memory type this node is serializing.  Usually either rawptr or bottom.
 977   const TypePtr* _adr_type;
 978 
 979 public:
 980   enum {
 981     Precedent = TypeFunc::Parms  // optional edge to force precedence
 982   };
 983   MemBarNode(Compile* C, int alias_idx, Node* precedent);
 984   virtual int Opcode() const = 0;
 985   virtual const class TypePtr *adr_type() const { return _adr_type; }
 986   virtual const Type *Value( PhaseTransform *phase ) const;
 987   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
 988   virtual uint match_edge(uint idx) const { return 0; }
 989   virtual const Type *bottom_type() const { return TypeTuple::MEMBAR; }
 990   virtual Node *match( const ProjNode *proj, const Matcher *m );
 991   // Factory method.  Builds a wide or narrow membar.
 992   // Optional 'precedent' becomes an extra edge if not null.
 993   static MemBarNode* make(Compile* C, int opcode,
 994                           int alias_idx = Compile::AliasIdxBot,
 995                           Node* precedent = NULL);
 996 };
 997 
 998 // "Acquire" - no following ref can move before (but earlier refs can
 999 // follow, like an early Load stalled in cache).  Requires multi-cpu
1000 // visibility.  Inserted after a volatile load.
1001 class MemBarAcquireNode: public MemBarNode {
1002 public:
1003   MemBarAcquireNode(Compile* C, int alias_idx, Node* precedent)
1004     : MemBarNode(C, alias_idx, precedent) {}
1005   virtual int Opcode() const;
1006 };
1007 
1008 // "Acquire" - no following ref can move before (but earlier refs can
1009 // follow, like an early Load stalled in cache).  Requires multi-cpu
1010 // visibility.  Inserted independ of any load, as required
1011 // for intrinsic Unsafe.loadFence().
1012 class LoadFenceNode: public MemBarNode {
1013 public:
1014   LoadFenceNode(Compile* C, int alias_idx, Node* precedent)
1015     : MemBarNode(C, alias_idx, precedent) {}
1016   virtual int Opcode() const;
1017 };
1018 
1019 // "Release" - no earlier ref can move after (but later refs can move
1020 // up, like a speculative pipelined cache-hitting Load).  Requires
1021 // multi-cpu visibility.  Inserted before a volatile store.
1022 class MemBarReleaseNode: public MemBarNode {
1023 public:
1024   MemBarReleaseNode(Compile* C, int alias_idx, Node* precedent)
1025     : MemBarNode(C, alias_idx, precedent) {}
1026   virtual int Opcode() const;
1027 };
1028 
1029 // "Release" - no earlier ref can move after (but later refs can move
1030 // up, like a speculative pipelined cache-hitting Load).  Requires
1031 // multi-cpu visibility.  Inserted independent of any store, as required
1032 // for intrinsic Unsafe.storeFence().
1033 class StoreFenceNode: public MemBarNode {
1034 public:
1035   StoreFenceNode(Compile* C, int alias_idx, Node* precedent)
1036     : MemBarNode(C, alias_idx, precedent) {}
1037   virtual int Opcode() const;
1038 };
1039 
1040 // "Acquire" - no following ref can move before (but earlier refs can
1041 // follow, like an early Load stalled in cache).  Requires multi-cpu
1042 // visibility.  Inserted after a FastLock.
1043 class MemBarAcquireLockNode: public MemBarNode {
1044 public:
1045   MemBarAcquireLockNode(Compile* C, int alias_idx, Node* precedent)
1046     : MemBarNode(C, alias_idx, precedent) {}
1047   virtual int Opcode() const;
1048 };
1049 
1050 // "Release" - no earlier ref can move after (but later refs can move
1051 // up, like a speculative pipelined cache-hitting Load).  Requires
1052 // multi-cpu visibility.  Inserted before a FastUnLock.
1053 class MemBarReleaseLockNode: public MemBarNode {
1054 public:
1055   MemBarReleaseLockNode(Compile* C, int alias_idx, Node* precedent)
1056     : MemBarNode(C, alias_idx, precedent) {}
1057   virtual int Opcode() const;
1058 };
1059 
1060 class MemBarStoreStoreNode: public MemBarNode {
1061 public:
1062   MemBarStoreStoreNode(Compile* C, int alias_idx, Node* precedent)
1063     : MemBarNode(C, alias_idx, precedent) {
1064     init_class_id(Class_MemBarStoreStore);
1065   }
1066   virtual int Opcode() const;
1067 };
1068 
1069 // Ordering between a volatile store and a following volatile load.
1070 // Requires multi-CPU visibility?
1071 class MemBarVolatileNode: public MemBarNode {
1072 public:
1073   MemBarVolatileNode(Compile* C, int alias_idx, Node* precedent)
1074     : MemBarNode(C, alias_idx, precedent) {}
1075   virtual int Opcode() const;
1076 };
1077 
1078 // Ordering within the same CPU.  Used to order unsafe memory references
1079 // inside the compiler when we lack alias info.  Not needed "outside" the
1080 // compiler because the CPU does all the ordering for us.
1081 class MemBarCPUOrderNode: public MemBarNode {
1082 public:
1083   MemBarCPUOrderNode(Compile* C, int alias_idx, Node* precedent)
1084     : MemBarNode(C, alias_idx, precedent) {}
1085   virtual int Opcode() const;
1086   virtual uint ideal_reg() const { return 0; } // not matched in the AD file
1087 };
1088 
1089 class OnSpinWaitNode: public MemBarNode {
1090 public:
1091   OnSpinWaitNode(Compile* C, int alias_idx, Node* precedent)
1092     : MemBarNode(C, alias_idx, precedent) {}
1093   virtual int Opcode() const;
1094 };
1095 
1096 // Isolation of object setup after an AllocateNode and before next safepoint.
1097 // (See comment in memnode.cpp near InitializeNode::InitializeNode for semantics.)
1098 class InitializeNode: public MemBarNode {
1099   friend class AllocateNode;
1100 
1101   enum {
1102     Incomplete    = 0,
1103     Complete      = 1,
1104     WithArraycopy = 2
1105   };
1106   int _is_complete;
1107 
1108   bool _does_not_escape;
1109 
1110 public:
1111   enum {
1112     Control    = TypeFunc::Control,
1113     Memory     = TypeFunc::Memory,     // MergeMem for states affected by this op
1114     RawAddress = TypeFunc::Parms+0,    // the newly-allocated raw address
1115     RawStores  = TypeFunc::Parms+1     // zero or more stores (or TOP)
1116   };
1117 
1118   InitializeNode(Compile* C, int adr_type, Node* rawoop);
1119   virtual int Opcode() const;
1120   virtual uint size_of() const { return sizeof(*this); }
1121   virtual uint ideal_reg() const { return 0; } // not matched in the AD file
1122   virtual const RegMask &in_RegMask(uint) const;  // mask for RawAddress
1123 
1124   // Manage incoming memory edges via a MergeMem on in(Memory):
1125   Node* memory(uint alias_idx);
1126 
1127   // The raw memory edge coming directly from the Allocation.
1128   // The contents of this memory are *always* all-zero-bits.
1129   Node* zero_memory() { return memory(Compile::AliasIdxRaw); }
1130 
1131   // Return the corresponding allocation for this initialization (or null if none).
1132   // (Note: Both InitializeNode::allocation and AllocateNode::initialization
1133   // are defined in graphKit.cpp, which sets up the bidirectional relation.)
1134   AllocateNode* allocation();
1135 
1136   // Anything other than zeroing in this init?
1137   bool is_non_zero();
1138 
1139   // An InitializeNode must completed before macro expansion is done.
1140   // Completion requires that the AllocateNode must be followed by
1141   // initialization of the new memory to zero, then to any initializers.
1142   bool is_complete() { return _is_complete != Incomplete; }
1143   bool is_complete_with_arraycopy() { return (_is_complete & WithArraycopy) != 0; }
1144 
1145   // Mark complete.  (Must not yet be complete.)
1146   void set_complete(PhaseGVN* phase);
1147   void set_complete_with_arraycopy() { _is_complete = Complete | WithArraycopy; }
1148 
1149   bool does_not_escape() { return _does_not_escape; }
1150   void set_does_not_escape() { _does_not_escape = true; }
1151 
1152 #ifdef ASSERT
1153   // ensure all non-degenerate stores are ordered and non-overlapping
1154   bool stores_are_sane(PhaseTransform* phase);
1155 #endif //ASSERT
1156 
1157   // See if this store can be captured; return offset where it initializes.
1158   // Return 0 if the store cannot be moved (any sort of problem).
1159   intptr_t can_capture_store(StoreNode* st, PhaseTransform* phase, bool can_reshape);
1160 
1161   // Capture another store; reformat it to write my internal raw memory.
1162   // Return the captured copy, else NULL if there is some sort of problem.
1163   Node* capture_store(StoreNode* st, intptr_t start, PhaseTransform* phase, bool can_reshape);
1164 
1165   // Find captured store which corresponds to the range [start..start+size).
1166   // Return my own memory projection (meaning the initial zero bits)
1167   // if there is no such store.  Return NULL if there is a problem.
1168   Node* find_captured_store(intptr_t start, int size_in_bytes, PhaseTransform* phase);
1169 
1170   // Called when the associated AllocateNode is expanded into CFG.
1171   Node* complete_stores(Node* rawctl, Node* rawmem, Node* rawptr,
1172                         intptr_t header_size, Node* size_in_bytes,
1173                         PhaseGVN* phase);
1174 
1175  private:
1176   void remove_extra_zeroes();
1177 
1178   // Find out where a captured store should be placed (or already is placed).
1179   int captured_store_insertion_point(intptr_t start, int size_in_bytes,
1180                                      PhaseTransform* phase);
1181 
1182   static intptr_t get_store_offset(Node* st, PhaseTransform* phase);
1183 
1184   Node* make_raw_address(intptr_t offset, PhaseTransform* phase);
1185 
1186   bool detect_init_independence(Node* n, int& count);
1187 
1188   void coalesce_subword_stores(intptr_t header_size, Node* size_in_bytes,
1189                                PhaseGVN* phase);
1190 
1191   intptr_t find_next_fullword_store(uint i, PhaseGVN* phase);
1192 };
1193 
1194 //------------------------------MergeMem---------------------------------------
1195 // (See comment in memnode.cpp near MergeMemNode::MergeMemNode for semantics.)
1196 class MergeMemNode: public Node {
1197   virtual uint hash() const ;                  // { return NO_HASH; }
1198   virtual uint cmp( const Node &n ) const ;    // Always fail, except on self
1199   friend class MergeMemStream;
1200   MergeMemNode(Node* def);  // clients use MergeMemNode::make
1201 
1202 public:
1203   // If the input is a whole memory state, clone it with all its slices intact.
1204   // Otherwise, make a new memory state with just that base memory input.
1205   // In either case, the result is a newly created MergeMem.
1206   static MergeMemNode* make(Node* base_memory);
1207 
1208   virtual int Opcode() const;
1209   virtual Node *Identity( PhaseTransform *phase );
1210   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
1211   virtual uint ideal_reg() const { return NotAMachineReg; }
1212   virtual uint match_edge(uint idx) const { return 0; }
1213   virtual const RegMask &out_RegMask() const;
1214   virtual const Type *bottom_type() const { return Type::MEMORY; }
1215   virtual const TypePtr *adr_type() const { return TypePtr::BOTTOM; }
1216   // sparse accessors
1217   // Fetch the previously stored "set_memory_at", or else the base memory.
1218   // (Caller should clone it if it is a phi-nest.)
1219   Node* memory_at(uint alias_idx) const;
1220   // set the memory, regardless of its previous value
1221   void set_memory_at(uint alias_idx, Node* n);
1222   // the "base" is the memory that provides the non-finite support
1223   Node* base_memory() const       { return in(Compile::AliasIdxBot); }
1224   // warning: setting the base can implicitly set any of the other slices too
1225   void set_base_memory(Node* def);
1226   // sentinel value which denotes a copy of the base memory:
1227   Node*   empty_memory() const    { return in(Compile::AliasIdxTop); }
1228   static Node* make_empty_memory(); // where the sentinel comes from
1229   bool is_empty_memory(Node* n) const { assert((n == empty_memory()) == n->is_top(), "sanity"); return n->is_top(); }
1230   // hook for the iterator, to perform any necessary setup
1231   void iteration_setup(const MergeMemNode* other = NULL);
1232   // push sentinels until I am at least as long as the other (semantic no-op)
1233   void grow_to_match(const MergeMemNode* other);
1234   bool verify_sparse() const PRODUCT_RETURN0;
1235 #ifndef PRODUCT
1236   virtual void dump_spec(outputStream *st) const;
1237 #endif
1238 };
1239 
1240 class MergeMemStream : public StackObj {
1241  private:
1242   MergeMemNode*       _mm;
1243   const MergeMemNode* _mm2;  // optional second guy, contributes non-empty iterations
1244   Node*               _mm_base;  // loop-invariant base memory of _mm
1245   int                 _idx;
1246   int                 _cnt;
1247   Node*               _mem;
1248   Node*               _mem2;
1249   int                 _cnt2;
1250 
1251   void init(MergeMemNode* mm, const MergeMemNode* mm2 = NULL) {
1252     // subsume_node will break sparseness at times, whenever a memory slice
1253     // folds down to a copy of the base ("fat") memory.  In such a case,
1254     // the raw edge will update to base, although it should be top.
1255     // This iterator will recognize either top or base_memory as an
1256     // "empty" slice.  See is_empty, is_empty2, and next below.
1257     //
1258     // The sparseness property is repaired in MergeMemNode::Ideal.
1259     // As long as access to a MergeMem goes through this iterator
1260     // or the memory_at accessor, flaws in the sparseness will
1261     // never be observed.
1262     //
1263     // Also, iteration_setup repairs sparseness.
1264     assert(mm->verify_sparse(), "please, no dups of base");
1265     assert(mm2==NULL || mm2->verify_sparse(), "please, no dups of base");
1266 
1267     _mm  = mm;
1268     _mm_base = mm->base_memory();
1269     _mm2 = mm2;
1270     _cnt = mm->req();
1271     _idx = Compile::AliasIdxBot-1; // start at the base memory
1272     _mem = NULL;
1273     _mem2 = NULL;
1274   }
1275 
1276 #ifdef ASSERT
1277   Node* check_memory() const {
1278     if (at_base_memory())
1279       return _mm->base_memory();
1280     else if ((uint)_idx < _mm->req() && !_mm->in(_idx)->is_top())
1281       return _mm->memory_at(_idx);
1282     else
1283       return _mm_base;
1284   }
1285   Node* check_memory2() const {
1286     return at_base_memory()? _mm2->base_memory(): _mm2->memory_at(_idx);
1287   }
1288 #endif
1289 
1290   static bool match_memory(Node* mem, const MergeMemNode* mm, int idx) PRODUCT_RETURN0;
1291   void assert_synch() const {
1292     assert(!_mem || _idx >= _cnt || match_memory(_mem, _mm, _idx),
1293            "no side-effects except through the stream");
1294   }
1295 
1296  public:
1297 
1298   // expected usages:
1299   // for (MergeMemStream mms(mem->is_MergeMem()); next_non_empty(); ) { ... }
1300   // for (MergeMemStream mms(mem1, mem2); next_non_empty2(); ) { ... }
1301 
1302   // iterate over one merge
1303   MergeMemStream(MergeMemNode* mm) {
1304     mm->iteration_setup();
1305     init(mm);
1306     debug_only(_cnt2 = 999);
1307   }
1308   // iterate in parallel over two merges
1309   // only iterates through non-empty elements of mm2
1310   MergeMemStream(MergeMemNode* mm, const MergeMemNode* mm2) {
1311     assert(mm2, "second argument must be a MergeMem also");
1312     ((MergeMemNode*)mm2)->iteration_setup();  // update hidden state
1313     mm->iteration_setup(mm2);
1314     init(mm, mm2);
1315     _cnt2 = mm2->req();
1316   }
1317 #ifdef ASSERT
1318   ~MergeMemStream() {
1319     assert_synch();
1320   }
1321 #endif
1322 
1323   MergeMemNode* all_memory() const {
1324     return _mm;
1325   }
1326   Node* base_memory() const {
1327     assert(_mm_base == _mm->base_memory(), "no update to base memory, please");
1328     return _mm_base;
1329   }
1330   const MergeMemNode* all_memory2() const {
1331     assert(_mm2 != NULL, "");
1332     return _mm2;
1333   }
1334   bool at_base_memory() const {
1335     return _idx == Compile::AliasIdxBot;
1336   }
1337   int alias_idx() const {
1338     assert(_mem, "must call next 1st");
1339     return _idx;
1340   }
1341 
1342   const TypePtr* adr_type() const {
1343     return Compile::current()->get_adr_type(alias_idx());
1344   }
1345 
1346   const TypePtr* adr_type(Compile* C) const {
1347     return C->get_adr_type(alias_idx());
1348   }
1349   bool is_empty() const {
1350     assert(_mem, "must call next 1st");
1351     assert(_mem->is_top() == (_mem==_mm->empty_memory()), "correct sentinel");
1352     return _mem->is_top();
1353   }
1354   bool is_empty2() const {
1355     assert(_mem2, "must call next 1st");
1356     assert(_mem2->is_top() == (_mem2==_mm2->empty_memory()), "correct sentinel");
1357     return _mem2->is_top();
1358   }
1359   Node* memory() const {
1360     assert(!is_empty(), "must not be empty");
1361     assert_synch();
1362     return _mem;
1363   }
1364   // get the current memory, regardless of empty or non-empty status
1365   Node* force_memory() const {
1366     assert(!is_empty() || !at_base_memory(), "");
1367     // Use _mm_base to defend against updates to _mem->base_memory().
1368     Node *mem = _mem->is_top() ? _mm_base : _mem;
1369     assert(mem == check_memory(), "");
1370     return mem;
1371   }
1372   Node* memory2() const {
1373     assert(_mem2 == check_memory2(), "");
1374     return _mem2;
1375   }
1376   void set_memory(Node* mem) {
1377     if (at_base_memory()) {
1378       // Note that this does not change the invariant _mm_base.
1379       _mm->set_base_memory(mem);
1380     } else {
1381       _mm->set_memory_at(_idx, mem);
1382     }
1383     _mem = mem;
1384     assert_synch();
1385   }
1386 
1387   // Recover from a side effect to the MergeMemNode.
1388   void set_memory() {
1389     _mem = _mm->in(_idx);
1390   }
1391 
1392   bool next()  { return next(false); }
1393   bool next2() { return next(true); }
1394 
1395   bool next_non_empty()  { return next_non_empty(false); }
1396   bool next_non_empty2() { return next_non_empty(true); }
1397   // next_non_empty2 can yield states where is_empty() is true
1398 
1399  private:
1400   // find the next item, which might be empty
1401   bool next(bool have_mm2) {
1402     assert((_mm2 != NULL) == have_mm2, "use other next");
1403     assert_synch();
1404     if (++_idx < _cnt) {
1405       // Note:  This iterator allows _mm to be non-sparse.
1406       // It behaves the same whether _mem is top or base_memory.
1407       _mem = _mm->in(_idx);
1408       if (have_mm2)
1409         _mem2 = _mm2->in((_idx < _cnt2) ? _idx : Compile::AliasIdxTop);
1410       return true;
1411     }
1412     return false;
1413   }
1414 
1415   // find the next non-empty item
1416   bool next_non_empty(bool have_mm2) {
1417     while (next(have_mm2)) {
1418       if (!is_empty()) {
1419         // make sure _mem2 is filled in sensibly
1420         if (have_mm2 && _mem2->is_top())  _mem2 = _mm2->base_memory();
1421         return true;
1422       } else if (have_mm2 && !is_empty2()) {
1423         return true;   // is_empty() == true
1424       }
1425     }
1426     return false;
1427   }
1428 };
1429 
1430 //------------------------------Prefetch---------------------------------------
1431 
1432 // Allocation prefetch which may fault, TLAB size have to be adjusted.
1433 class PrefetchAllocationNode : public Node {
1434 public:
1435   PrefetchAllocationNode(Node *mem, Node *adr) : Node(0,mem,adr) {}
1436   virtual int Opcode() const;
1437   virtual uint ideal_reg() const { return NotAMachineReg; }
1438   virtual uint match_edge(uint idx) const { return idx==2; }
1439   virtual const Type *bottom_type() const { return ( AllocatePrefetchStyle == 3 ) ? Type::MEMORY : Type::ABIO; }
1440 };
1441 
1442 #endif // SHARE_VM_OPTO_MEMNODE_HPP
--- EOF ---