1 /*
   2  * Copyright (c) 1997, 2013, 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 protected:
  43 #ifdef ASSERT
  44   const TypePtr* _adr_type;     // What kind of memory is being addressed?
  45 #endif
  46   virtual uint size_of() const; // Size is bigger (ASSERT only)
  47 public:
  48   enum { Control,               // When is it safe to do this load?
  49          Memory,                // Chunk of memory is being loaded from
  50          Address,               // Actually address, derived from base
  51          ValueIn,               // Value to store
  52          OopStore               // Preceeding oop store, only in StoreCM
  53   };
  54   typedef enum { unordered = 0,
  55                  acquire,       // Load has to acquire or be succeeded by MemBarAcquire.
  56                  release        // Store has to release or be preceded by MemBarRelease.
  57   } MemOrd;
  58 protected:
  59   MemNode( Node *c0, Node *c1, Node *c2, const TypePtr* at )
  60     : Node(c0,c1,c2   ) {
  61     init_class_id(Class_Mem);
  62     debug_only(_adr_type=at; adr_type();)
  63   }
  64   MemNode( Node *c0, Node *c1, Node *c2, const TypePtr* at, Node *c3 )
  65     : Node(c0,c1,c2,c3) {
  66     init_class_id(Class_Mem);
  67     debug_only(_adr_type=at; adr_type();)
  68   }
  69   MemNode( Node *c0, Node *c1, Node *c2, const TypePtr* at, Node *c3, Node *c4)
  70     : Node(c0,c1,c2,c3,c4) {
  71     init_class_id(Class_Mem);
  72     debug_only(_adr_type=at; adr_type();)
  73   }
  74 
  75 public:
  76   // Helpers for the optimizer.  Documented in memnode.cpp.
  77   static bool detect_ptr_independence(Node* p1, AllocateNode* a1,
  78                                       Node* p2, AllocateNode* a2,
  79                                       PhaseTransform* phase);
  80   static bool adr_phi_is_loop_invariant(Node* adr_phi, Node* cast);
  81 
  82   static Node *optimize_simple_memory_chain(Node *mchain, const TypeOopPtr *t_oop, Node *load, PhaseGVN *phase);
  83   static Node *optimize_memory_chain(Node *mchain, const TypePtr *t_adr, Node *load, PhaseGVN *phase);
  84   // This one should probably be a phase-specific function:
  85   static bool all_controls_dominate(Node* dom, Node* sub);
  86 
  87   // Find any cast-away of null-ness and keep its control.
  88   static  Node *Ideal_common_DU_postCCP( PhaseCCP *ccp, Node* n, Node* adr );
  89   virtual Node *Ideal_DU_postCCP( PhaseCCP *ccp );
  90 
  91   virtual const class TypePtr *adr_type() const;  // returns bottom_type of address
  92 
  93   // Shared code for Ideal methods:
  94   Node *Ideal_common(PhaseGVN *phase, bool can_reshape);  // Return -1 for short-circuit NULL.
  95 
  96   // Helper function for adr_type() implementations.
  97   static const TypePtr* calculate_adr_type(const Type* t, const TypePtr* cross_check = NULL);
  98 
  99   // Raw access function, to allow copying of adr_type efficiently in
 100   // product builds and retain the debug info for debug builds.
 101   const TypePtr *raw_adr_type() const {
 102 #ifdef ASSERT
 103     return _adr_type;
 104 #else
 105     return 0;
 106 #endif
 107   }
 108 
 109   // Map a load or store opcode to its corresponding store opcode.
 110   // (Return -1 if unknown.)
 111   virtual int store_Opcode() const { return -1; }
 112 
 113   // What is the type of the value in memory?  (T_VOID mean "unspecified".)
 114   virtual BasicType memory_type() const = 0;
 115   virtual int memory_size() const {
 116 #ifdef ASSERT
 117     return type2aelembytes(memory_type(), true);
 118 #else
 119     return type2aelembytes(memory_type());
 120 #endif
 121   }
 122 
 123   // Search through memory states which precede this node (load or store).
 124   // Look for an exact match for the address, with no intervening
 125   // aliased stores.
 126   Node* find_previous_store(PhaseTransform* phase);
 127 
 128   // Can this node (load or store) accurately see a stored value in
 129   // the given memory state?  (The state may or may not be in(Memory).)
 130   Node* can_see_stored_value(Node* st, PhaseTransform* phase) const;
 131 
 132 #ifndef PRODUCT
 133   static void dump_adr_type(const Node* mem, const TypePtr* adr_type, outputStream *st);
 134   virtual void dump_spec(outputStream *st) const;
 135 #endif
 136 };
 137 
 138 //------------------------------LoadNode---------------------------------------
 139 // Load value; requires Memory and Address
 140 class LoadNode : public MemNode {
 141 private:
 142   // On platforms with weak memory ordering (e.g., PPC, Ia64) we distinguish
 143   // loads that can be reordered, and such requiring acquire semantics to
 144   // adhere to the Java specification.  The required behaviour is stored in
 145   // this field.
 146   const MemOrd _mo;
 147 
 148 protected:
 149   virtual uint cmp(const Node &n) const;
 150   virtual uint size_of() const; // Size is bigger
 151   const Type* const _type;      // What kind of value is loaded?
 152 public:
 153 
 154   LoadNode(Node *c, Node *mem, Node *adr, const TypePtr* at, const Type *rt, MemOrd mo)
 155     : MemNode(c,mem,adr,at), _type(rt), _mo(mo) {
 156     init_class_id(Class_Load);
 157   }
 158   inline bool is_unordered() const { return !is_acquire(); }
 159   inline bool is_acquire() const {
 160     assert(_mo == unordered || _mo == acquire, "unexpected");
 161     return _mo == acquire;
 162   }
 163 
 164   // Polymorphic factory method:
 165    static Node* make(PhaseGVN& gvn, Node *c, Node *mem, Node *adr,
 166                      const TypePtr* at, const Type *rt, BasicType bt, MemOrd mo);
 167 
 168   virtual uint hash()   const;  // Check the type
 169 
 170   // Handle algebraic identities here.  If we have an identity, return the Node
 171   // we are equivalent to.  We look for Load of a Store.
 172   virtual Node *Identity( PhaseTransform *phase );
 173 
 174   // If the load is from Field memory and the pointer is non-null, we can
 175   // zero out the control input.
 176   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
 177 
 178   // Split instance field load through Phi.
 179   Node* split_through_phi(PhaseGVN *phase);
 180 
 181   // Recover original value from boxed values
 182   Node *eliminate_autobox(PhaseGVN *phase);
 183 
 184   // Compute a new Type for this node.  Basically we just do the pre-check,
 185   // then call the virtual add() to set the type.
 186   virtual const Type *Value( PhaseTransform *phase ) const;
 187 
 188   // Common methods for LoadKlass and LoadNKlass nodes.
 189   const Type *klass_value_common( PhaseTransform *phase ) const;
 190   Node *klass_identity_common( PhaseTransform *phase );
 191 
 192   virtual uint ideal_reg() const;
 193   virtual const Type *bottom_type() const;
 194   // Following method is copied from TypeNode:
 195   void set_type(const Type* t) {
 196     assert(t != NULL, "sanity");
 197     debug_only(uint check_hash = (VerifyHashTableKeys && _hash_lock) ? hash() : NO_HASH);
 198     *(const Type**)&_type = t;   // cast away const-ness
 199     // If this node is in the hash table, make sure it doesn't need a rehash.
 200     assert(check_hash == NO_HASH || check_hash == hash(), "type change must preserve hash code");
 201   }
 202   const Type* type() const { assert(_type != NULL, "sanity"); return _type; };
 203 
 204   // Do not match memory edge
 205   virtual uint match_edge(uint idx) const;
 206 
 207   // Map a load opcode to its corresponding store opcode.
 208   virtual int store_Opcode() const = 0;
 209 
 210   // Check if the load's memory input is a Phi node with the same control.
 211   bool is_instance_field_load_with_local_phi(Node* ctrl);
 212 
 213 #ifndef PRODUCT
 214   virtual void dump_spec(outputStream *st) const;
 215 #endif
 216 #ifdef ASSERT
 217   // Helper function to allow a raw load without control edge for some cases
 218   static bool is_immutable_value(Node* adr);
 219 #endif
 220 protected:
 221   const Type* load_array_final_field(const TypeKlassPtr *tkls,
 222                                      ciKlass* klass) const;
 223   // depends_only_on_test is almost always true, and needs to be almost always
 224   // true to enable key hoisting & commoning optimizations.  However, for the
 225   // special case of RawPtr loads from TLS top & end, and other loads performed by
 226   // GC barriers, the control edge carries the dependence preventing hoisting past
 227   // a Safepoint instead of the memory edge.  (An unfortunate consequence of having
 228   // Safepoints not set Raw Memory; itself an unfortunate consequence of having Nodes
 229   // which produce results (new raw memory state) inside of loops preventing all
 230   // manner of other optimizations).  Basically, it's ugly but so is the alternative.
 231   // See comment in macro.cpp, around line 125 expand_allocate_common().
 232   virtual bool depends_only_on_test() const { return adr_type() != TypeRawPtr::BOTTOM; }
 233 
 234 };
 235 
 236 //------------------------------LoadBNode--------------------------------------
 237 // Load a byte (8bits signed) from memory
 238 class LoadBNode : public LoadNode {
 239 public:
 240   LoadBNode(Node *c, Node *mem, Node *adr, const TypePtr* at, const TypeInt *ti, MemOrd mo)
 241     : LoadNode(c, mem, adr, at, ti, mo) {}
 242   virtual int Opcode() const;
 243   virtual uint ideal_reg() const { return Op_RegI; }
 244   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
 245   virtual const Type *Value(PhaseTransform *phase) const;
 246   virtual int store_Opcode() const { return Op_StoreB; }
 247   virtual BasicType memory_type() const { return T_BYTE; }
 248 };
 249 
 250 //------------------------------LoadUBNode-------------------------------------
 251 // Load a unsigned byte (8bits unsigned) from memory
 252 class LoadUBNode : public LoadNode {
 253 public:
 254   LoadUBNode(Node* c, Node* mem, Node* adr, const TypePtr* at, const TypeInt* ti, MemOrd mo)
 255     : LoadNode(c, mem, adr, at, ti, mo) {}
 256   virtual int Opcode() const;
 257   virtual uint ideal_reg() const { return Op_RegI; }
 258   virtual Node* Ideal(PhaseGVN *phase, bool can_reshape);
 259   virtual const Type *Value(PhaseTransform *phase) const;
 260   virtual int store_Opcode() const { return Op_StoreB; }
 261   virtual BasicType memory_type() const { return T_BYTE; }
 262 };
 263 
 264 //------------------------------LoadUSNode-------------------------------------
 265 // Load an unsigned short/char (16bits unsigned) from memory
 266 class LoadUSNode : public LoadNode {
 267 public:
 268   LoadUSNode(Node *c, Node *mem, Node *adr, const TypePtr* at, const TypeInt *ti, MemOrd mo)
 269     : LoadNode(c, mem, adr, at, ti, mo) {}
 270   virtual int Opcode() const;
 271   virtual uint ideal_reg() const { return Op_RegI; }
 272   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
 273   virtual const Type *Value(PhaseTransform *phase) const;
 274   virtual int store_Opcode() const { return Op_StoreC; }
 275   virtual BasicType memory_type() const { return T_CHAR; }
 276 };
 277 
 278 //------------------------------LoadSNode--------------------------------------
 279 // Load a short (16bits signed) from memory
 280 class LoadSNode : public LoadNode {
 281 public:
 282   LoadSNode(Node *c, Node *mem, Node *adr, const TypePtr* at, const TypeInt *ti, MemOrd mo)
 283     : LoadNode(c, mem, adr, at, ti, mo) {}
 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_StoreC; }
 289   virtual BasicType memory_type() const { return T_SHORT; }
 290 };
 291 
 292 //------------------------------LoadINode--------------------------------------
 293 // Load an integer from memory
 294 class LoadINode : public LoadNode {
 295 public:
 296   LoadINode(Node *c, Node *mem, Node *adr, const TypePtr* at, const TypeInt *ti, MemOrd mo)
 297     : LoadNode(c, mem, adr, at, ti, mo) {}
 298   virtual int Opcode() const;
 299   virtual uint ideal_reg() const { return Op_RegI; }
 300   virtual int store_Opcode() const { return Op_StoreI; }
 301   virtual BasicType memory_type() const { return T_INT; }
 302 };
 303 
 304 //------------------------------LoadRangeNode----------------------------------
 305 // Load an array length from the array
 306 class LoadRangeNode : public LoadINode {
 307 public:
 308   LoadRangeNode(Node *c, Node *mem, Node *adr, const TypeInt *ti = TypeInt::POS)
 309     : LoadINode(c, mem, adr, TypeAryPtr::RANGE, ti, MemNode::unordered) {}
 310   virtual int Opcode() const;
 311   virtual const Type *Value( PhaseTransform *phase ) const;
 312   virtual Node *Identity( PhaseTransform *phase );
 313   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
 314 };
 315 
 316 //------------------------------LoadLNode--------------------------------------
 317 // Load a long from memory
 318 class LoadLNode : public LoadNode {
 319   virtual uint hash() const { return LoadNode::hash() + _require_atomic_access; }
 320   virtual uint cmp( const Node &n ) const {
 321     return _require_atomic_access == ((LoadLNode&)n)._require_atomic_access
 322       && LoadNode::cmp(n);
 323   }
 324   virtual uint size_of() const { return sizeof(*this); }
 325   const bool _require_atomic_access;  // is piecewise load forbidden?
 326 
 327 public:
 328   LoadLNode(Node *c, Node *mem, Node *adr, const TypePtr* at, const TypeLong *tl,
 329             MemOrd mo, bool require_atomic_access = false)
 330     : LoadNode(c, mem, adr, at, tl, mo), _require_atomic_access(require_atomic_access) {}
 331   virtual int Opcode() const;
 332   virtual uint ideal_reg() const { return Op_RegL; }
 333   virtual int store_Opcode() const { return Op_StoreL; }
 334   virtual BasicType memory_type() const { return T_LONG; }
 335   bool require_atomic_access() { return _require_atomic_access; }
 336   static LoadLNode* make_atomic(Compile *C, Node* ctl, Node* mem, Node* adr, const TypePtr* adr_type,
 337                                 const Type* rt, MemOrd mo);
 338 #ifndef PRODUCT
 339   virtual void dump_spec(outputStream *st) const {
 340     LoadNode::dump_spec(st);
 341     if (_require_atomic_access)  st->print(" Atomic!");
 342   }
 343 #endif
 344 };
 345 
 346 //------------------------------LoadL_unalignedNode----------------------------
 347 // Load a long from unaligned memory
 348 class LoadL_unalignedNode : public LoadLNode {
 349 public:
 350   LoadL_unalignedNode(Node *c, Node *mem, Node *adr, const TypePtr* at, MemOrd mo)
 351     : LoadLNode(c, mem, adr, at, TypeLong::LONG, mo) {}
 352   virtual int Opcode() const;
 353 };
 354 
 355 //------------------------------LoadFNode--------------------------------------
 356 // Load a float (64 bits) from memory
 357 class LoadFNode : public LoadNode {
 358 public:
 359   LoadFNode(Node *c, Node *mem, Node *adr, const TypePtr* at, const Type *t, MemOrd mo)
 360     : LoadNode(c, mem, adr, at, t, mo) {}
 361   virtual int Opcode() const;
 362   virtual uint ideal_reg() const { return Op_RegF; }
 363   virtual int store_Opcode() const { return Op_StoreF; }
 364   virtual BasicType memory_type() const { return T_FLOAT; }
 365 };
 366 
 367 //------------------------------LoadDNode--------------------------------------
 368 // Load a double (64 bits) from memory
 369 class LoadDNode : public LoadNode {








 370 public:
 371   LoadDNode(Node *c, Node *mem, Node *adr, const TypePtr* at, const Type *t, MemOrd mo)
 372     : LoadNode(c, mem, adr, at, t, mo) {}

 373   virtual int Opcode() const;
 374   virtual uint ideal_reg() const { return Op_RegD; }
 375   virtual int store_Opcode() const { return Op_StoreD; }
 376   virtual BasicType memory_type() const { return T_DOUBLE; }









 377 };
 378 
 379 //------------------------------LoadD_unalignedNode----------------------------
 380 // Load a double from unaligned memory
 381 class LoadD_unalignedNode : public LoadDNode {
 382 public:
 383   LoadD_unalignedNode(Node *c, Node *mem, Node *adr, const TypePtr* at, MemOrd mo)
 384     : LoadDNode(c, mem, adr, at, Type::DOUBLE, mo) {}
 385   virtual int Opcode() const;
 386 };
 387 
 388 //------------------------------LoadPNode--------------------------------------
 389 // Load a pointer from memory (either object or array)
 390 class LoadPNode : public LoadNode {
 391 public:
 392   LoadPNode(Node *c, Node *mem, Node *adr, const TypePtr *at, const TypePtr* t, MemOrd mo)
 393     : LoadNode(c, mem, adr, at, t, mo) {}
 394   virtual int Opcode() const;
 395   virtual uint ideal_reg() const { return Op_RegP; }
 396   virtual int store_Opcode() const { return Op_StoreP; }
 397   virtual BasicType memory_type() const { return T_ADDRESS; }
 398 };
 399 
 400 
 401 //------------------------------LoadNNode--------------------------------------
 402 // Load a narrow oop from memory (either object or array)
 403 class LoadNNode : public LoadNode {
 404 public:
 405   LoadNNode(Node *c, Node *mem, Node *adr, const TypePtr *at, const Type* t, MemOrd mo)
 406     : LoadNode(c, mem, adr, at, t, mo) {}
 407   virtual int Opcode() const;
 408   virtual uint ideal_reg() const { return Op_RegN; }
 409   virtual int store_Opcode() const { return Op_StoreN; }
 410   virtual BasicType memory_type() const { return T_NARROWOOP; }
 411 };
 412 
 413 //------------------------------LoadKlassNode----------------------------------
 414 // Load a Klass from an object
 415 class LoadKlassNode : public LoadPNode {
 416 public:
 417   LoadKlassNode(Node *c, Node *mem, Node *adr, const TypePtr *at, const TypeKlassPtr *tk, MemOrd mo)
 418     : LoadPNode(c, mem, adr, at, tk, mo) {}
 419   virtual int Opcode() const;
 420   virtual const Type *Value( PhaseTransform *phase ) const;
 421   virtual Node *Identity( PhaseTransform *phase );
 422   virtual bool depends_only_on_test() const { return true; }
 423 
 424   // Polymorphic factory method:
 425   static Node* make( PhaseGVN& gvn, Node *mem, Node *adr, const TypePtr* at,
 426                      const TypeKlassPtr *tk = TypeKlassPtr::OBJECT );
 427 };
 428 
 429 //------------------------------LoadNKlassNode---------------------------------
 430 // Load a narrow Klass from an object.
 431 class LoadNKlassNode : public LoadNNode {
 432 public:
 433   LoadNKlassNode(Node *c, Node *mem, Node *adr, const TypePtr *at, const TypeNarrowKlass *tk, MemOrd mo)
 434     : LoadNNode(c, mem, adr, at, tk, mo) {}
 435   virtual int Opcode() const;
 436   virtual uint ideal_reg() const { return Op_RegN; }
 437   virtual int store_Opcode() const { return Op_StoreNKlass; }
 438   virtual BasicType memory_type() const { return T_NARROWKLASS; }
 439 
 440   virtual const Type *Value( PhaseTransform *phase ) const;
 441   virtual Node *Identity( PhaseTransform *phase );
 442   virtual bool depends_only_on_test() const { return true; }
 443 };
 444 
 445 
 446 //------------------------------StoreNode--------------------------------------
 447 // Store value; requires Store, Address and Value
 448 class StoreNode : public MemNode {
 449 private:
 450   // On platforms with weak memory ordering (e.g., PPC, Ia64) we distinguish
 451   // stores that can be reordered, and such requiring release semantics to
 452   // adhere to the Java specification.  The required behaviour is stored in
 453   // this field.
 454   const MemOrd _mo;
 455   // Needed for proper cloning.
 456   virtual uint size_of() const { return sizeof(*this); }
 457 protected:
 458   virtual uint cmp( const Node &n ) const;
 459   virtual bool depends_only_on_test() const { return false; }
 460 
 461   Node *Ideal_masked_input       (PhaseGVN *phase, uint mask);
 462   Node *Ideal_sign_extended_input(PhaseGVN *phase, int  num_bits);
 463 
 464 public:
 465   // We must ensure that stores of object references will be visible
 466   // only after the object's initialization. So the callers of this
 467   // procedure must indicate that the store requires `release'
 468   // semantics, if the stored value is an object reference that might
 469   // point to a new object and may become externally visible.
 470   StoreNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, MemOrd mo)
 471     : MemNode(c, mem, adr, at, val), _mo(mo) {
 472     init_class_id(Class_Store);
 473   }
 474   StoreNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, Node *oop_store, MemOrd mo)
 475     : MemNode(c, mem, adr, at, val, oop_store), _mo(mo) {
 476     init_class_id(Class_Store);
 477   }
 478 
 479   inline bool is_unordered() const { return !is_release(); }
 480   inline bool is_release() const {
 481     assert((_mo == unordered || _mo == release), "unexpected");
 482     return _mo == release;
 483   }
 484 
 485   // Conservatively release stores of object references in order to
 486   // ensure visibility of object initialization.
 487   static inline MemOrd release_if_reference(const BasicType t) {
 488     const MemOrd mo = (t == T_ARRAY ||
 489                        t == T_ADDRESS || // Might be the address of an object reference (`boxing').
 490                        t == T_OBJECT) ? release : unordered;
 491     return mo;
 492   }
 493 
 494   // Polymorphic factory method
 495   //
 496   // We must ensure that stores of object references will be visible
 497   // only after the object's initialization. So the callers of this
 498   // procedure must indicate that the store requires `release'
 499   // semantics, if the stored value is an object reference that might
 500   // point to a new object and may become externally visible.
 501   static StoreNode* make(PhaseGVN& gvn, Node *c, Node *mem, Node *adr,
 502                          const TypePtr* at, Node *val, BasicType bt, MemOrd mo);
 503 
 504   virtual uint hash() const;    // Check the type
 505 
 506   // If the store is to Field memory and the pointer is non-null, we can
 507   // zero out the control input.
 508   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
 509 
 510   // Compute a new Type for this node.  Basically we just do the pre-check,
 511   // then call the virtual add() to set the type.
 512   virtual const Type *Value( PhaseTransform *phase ) const;
 513 
 514   // Check for identity function on memory (Load then Store at same address)
 515   virtual Node *Identity( PhaseTransform *phase );
 516 
 517   // Do not match memory edge
 518   virtual uint match_edge(uint idx) const;
 519 
 520   virtual const Type *bottom_type() const;  // returns Type::MEMORY
 521 
 522   // Map a store opcode to its corresponding own opcode, trivially.
 523   virtual int store_Opcode() const { return Opcode(); }
 524 
 525   // have all possible loads of the value stored been optimized away?
 526   bool value_never_loaded(PhaseTransform *phase) const;
 527 };
 528 
 529 //------------------------------StoreBNode-------------------------------------
 530 // Store byte to memory
 531 class StoreBNode : public StoreNode {
 532 public:
 533   StoreBNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, MemOrd mo)
 534     : StoreNode(c, mem, adr, at, val, mo) {}
 535   virtual int Opcode() const;
 536   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
 537   virtual BasicType memory_type() const { return T_BYTE; }
 538 };
 539 
 540 //------------------------------StoreCNode-------------------------------------
 541 // Store char/short to memory
 542 class StoreCNode : public StoreNode {
 543 public:
 544   StoreCNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, MemOrd mo)
 545     : StoreNode(c, mem, adr, at, val, mo) {}
 546   virtual int Opcode() const;
 547   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
 548   virtual BasicType memory_type() const { return T_CHAR; }
 549 };
 550 
 551 //------------------------------StoreINode-------------------------------------
 552 // Store int to memory
 553 class StoreINode : public StoreNode {
 554 public:
 555   StoreINode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, MemOrd mo)
 556     : StoreNode(c, mem, adr, at, val, mo) {}
 557   virtual int Opcode() const;
 558   virtual BasicType memory_type() const { return T_INT; }
 559 };
 560 
 561 //------------------------------StoreLNode-------------------------------------
 562 // Store long to memory
 563 class StoreLNode : public StoreNode {
 564   virtual uint hash() const { return StoreNode::hash() + _require_atomic_access; }
 565   virtual uint cmp( const Node &n ) const {
 566     return _require_atomic_access == ((StoreLNode&)n)._require_atomic_access
 567       && StoreNode::cmp(n);
 568   }
 569   virtual uint size_of() const { return sizeof(*this); }
 570   const bool _require_atomic_access;  // is piecewise store forbidden?
 571 
 572 public:
 573   StoreLNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, MemOrd mo, bool require_atomic_access = false)
 574     : StoreNode(c, mem, adr, at, val, mo), _require_atomic_access(require_atomic_access) {}
 575   virtual int Opcode() const;
 576   virtual BasicType memory_type() const { return T_LONG; }
 577   bool require_atomic_access() { return _require_atomic_access; }
 578   static StoreLNode* make_atomic(Compile *C, Node* ctl, Node* mem, Node* adr, const TypePtr* adr_type, Node* val, MemOrd mo);
 579 #ifndef PRODUCT
 580   virtual void dump_spec(outputStream *st) const {
 581     StoreNode::dump_spec(st);
 582     if (_require_atomic_access)  st->print(" Atomic!");
 583   }
 584 #endif
 585 };
 586 
 587 //------------------------------StoreFNode-------------------------------------
 588 // Store float to memory
 589 class StoreFNode : public StoreNode {
 590 public:
 591   StoreFNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, MemOrd mo)
 592     : StoreNode(c, mem, adr, at, val, mo) {}
 593   virtual int Opcode() const;
 594   virtual BasicType memory_type() const { return T_FLOAT; }
 595 };
 596 
 597 //------------------------------StoreDNode-------------------------------------
 598 // Store double to memory
 599 class StoreDNode : public StoreNode {







 600 public:
 601   StoreDNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, MemOrd mo)
 602     : StoreNode(c, mem, adr, at, val, mo) {}

 603   virtual int Opcode() const;
 604   virtual BasicType memory_type() const { return T_DOUBLE; }









 605 };
 606 
 607 //------------------------------StorePNode-------------------------------------
 608 // Store pointer to memory
 609 class StorePNode : public StoreNode {
 610 public:
 611   StorePNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, MemOrd mo)
 612     : StoreNode(c, mem, adr, at, val, mo) {}
 613   virtual int Opcode() const;
 614   virtual BasicType memory_type() const { return T_ADDRESS; }
 615 };
 616 
 617 //------------------------------StoreNNode-------------------------------------
 618 // Store narrow oop to memory
 619 class StoreNNode : public StoreNode {
 620 public:
 621   StoreNNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, MemOrd mo)
 622     : StoreNode(c, mem, adr, at, val, mo) {}
 623   virtual int Opcode() const;
 624   virtual BasicType memory_type() const { return T_NARROWOOP; }
 625 };
 626 
 627 //------------------------------StoreNKlassNode--------------------------------------
 628 // Store narrow klass to memory
 629 class StoreNKlassNode : public StoreNNode {
 630 public:
 631   StoreNKlassNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, MemOrd mo)
 632     : StoreNNode(c, mem, adr, at, val, mo) {}
 633   virtual int Opcode() const;
 634   virtual BasicType memory_type() const { return T_NARROWKLASS; }
 635 };
 636 
 637 //------------------------------StoreCMNode-----------------------------------
 638 // Store card-mark byte to memory for CM
 639 // The last StoreCM before a SafePoint must be preserved and occur after its "oop" store
 640 // Preceeding equivalent StoreCMs may be eliminated.
 641 class StoreCMNode : public StoreNode {
 642  private:
 643   virtual uint hash() const { return StoreNode::hash() + _oop_alias_idx; }
 644   virtual uint cmp( const Node &n ) const {
 645     return _oop_alias_idx == ((StoreCMNode&)n)._oop_alias_idx
 646       && StoreNode::cmp(n);
 647   }
 648   virtual uint size_of() const { return sizeof(*this); }
 649   int _oop_alias_idx;   // The alias_idx of OopStore
 650 
 651 public:
 652   StoreCMNode( Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, Node *oop_store, int oop_alias_idx ) :
 653     StoreNode(c, mem, adr, at, val, oop_store, MemNode::release),
 654     _oop_alias_idx(oop_alias_idx) {
 655     assert(_oop_alias_idx >= Compile::AliasIdxRaw ||
 656            _oop_alias_idx == Compile::AliasIdxBot && Compile::current()->AliasLevel() == 0,
 657            "bad oop alias idx");
 658   }
 659   virtual int Opcode() const;
 660   virtual Node *Identity( PhaseTransform *phase );
 661   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
 662   virtual const Type *Value( PhaseTransform *phase ) const;
 663   virtual BasicType memory_type() const { return T_VOID; } // unspecific
 664   int oop_alias_idx() const { return _oop_alias_idx; }
 665 };
 666 
 667 //------------------------------LoadPLockedNode---------------------------------
 668 // Load-locked a pointer from memory (either object or array).
 669 // On Sparc & Intel this is implemented as a normal pointer load.
 670 // On PowerPC and friends it's a real load-locked.
 671 class LoadPLockedNode : public LoadPNode {
 672 public:
 673   LoadPLockedNode(Node *c, Node *mem, Node *adr, MemOrd mo)
 674     : LoadPNode(c, mem, adr, TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM, mo) {}
 675   virtual int Opcode() const;
 676   virtual int store_Opcode() const { return Op_StorePConditional; }
 677   virtual bool depends_only_on_test() const { return true; }
 678 };
 679 
 680 //------------------------------SCMemProjNode---------------------------------------
 681 // This class defines a projection of the memory  state of a store conditional node.
 682 // These nodes return a value, but also update memory.
 683 class SCMemProjNode : public ProjNode {
 684 public:
 685   enum {SCMEMPROJCON = (uint)-2};
 686   SCMemProjNode( Node *src) : ProjNode( src, SCMEMPROJCON) { }
 687   virtual int Opcode() const;
 688   virtual bool      is_CFG() const  { return false; }
 689   virtual const Type *bottom_type() const {return Type::MEMORY;}
 690   virtual const TypePtr *adr_type() const { return in(0)->in(MemNode::Memory)->adr_type();}
 691   virtual uint ideal_reg() const { return 0;} // memory projections don't have a register
 692   virtual const Type *Value( PhaseTransform *phase ) const;
 693 #ifndef PRODUCT
 694   virtual void dump_spec(outputStream *st) const {};
 695 #endif
 696 };
 697 
 698 //------------------------------LoadStoreNode---------------------------
 699 // Note: is_Mem() method returns 'true' for this class.
 700 class LoadStoreNode : public Node {
 701 private:
 702   const Type* const _type;      // What kind of value is loaded?
 703   const TypePtr* _adr_type;     // What kind of memory is being addressed?
 704   virtual uint size_of() const; // Size is bigger
 705 public:
 706   LoadStoreNode( Node *c, Node *mem, Node *adr, Node *val, const TypePtr* at, const Type* rt, uint required );
 707   virtual bool depends_only_on_test() const { return false; }
 708   virtual uint match_edge(uint idx) const { return idx == MemNode::Address || idx == MemNode::ValueIn; }
 709 
 710   virtual const Type *bottom_type() const { return _type; }
 711   virtual uint ideal_reg() const;
 712   virtual const class TypePtr *adr_type() const { return _adr_type; }  // returns bottom_type of address
 713 
 714   bool result_not_used() const;
 715 };
 716 
 717 class LoadStoreConditionalNode : public LoadStoreNode {
 718 public:
 719   enum {
 720     ExpectedIn = MemNode::ValueIn+1 // One more input than MemNode
 721   };
 722   LoadStoreConditionalNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex);
 723 };
 724 
 725 //------------------------------StorePConditionalNode---------------------------
 726 // Conditionally store pointer to memory, if no change since prior
 727 // load-locked.  Sets flags for success or failure of the store.
 728 class StorePConditionalNode : public LoadStoreConditionalNode {
 729 public:
 730   StorePConditionalNode( Node *c, Node *mem, Node *adr, Node *val, Node *ll ) : LoadStoreConditionalNode(c, mem, adr, val, ll) { }
 731   virtual int Opcode() const;
 732   // Produces flags
 733   virtual uint ideal_reg() const { return Op_RegFlags; }
 734 };
 735 
 736 //------------------------------StoreIConditionalNode---------------------------
 737 // Conditionally store int to memory, if no change since prior
 738 // load-locked.  Sets flags for success or failure of the store.
 739 class StoreIConditionalNode : public LoadStoreConditionalNode {
 740 public:
 741   StoreIConditionalNode( Node *c, Node *mem, Node *adr, Node *val, Node *ii ) : LoadStoreConditionalNode(c, mem, adr, val, ii) { }
 742   virtual int Opcode() const;
 743   // Produces flags
 744   virtual uint ideal_reg() const { return Op_RegFlags; }
 745 };
 746 
 747 //------------------------------StoreLConditionalNode---------------------------
 748 // Conditionally store long to memory, if no change since prior
 749 // load-locked.  Sets flags for success or failure of the store.
 750 class StoreLConditionalNode : public LoadStoreConditionalNode {
 751 public:
 752   StoreLConditionalNode( Node *c, Node *mem, Node *adr, Node *val, Node *ll ) : LoadStoreConditionalNode(c, mem, adr, val, ll) { }
 753   virtual int Opcode() const;
 754   // Produces flags
 755   virtual uint ideal_reg() const { return Op_RegFlags; }
 756 };
 757 
 758 
 759 //------------------------------CompareAndSwapLNode---------------------------
 760 class CompareAndSwapLNode : public LoadStoreConditionalNode {
 761 public:
 762   CompareAndSwapLNode( Node *c, Node *mem, Node *adr, Node *val, Node *ex) : LoadStoreConditionalNode(c, mem, adr, val, ex) { }
 763   virtual int Opcode() const;
 764 };
 765 
 766 
 767 //------------------------------CompareAndSwapINode---------------------------
 768 class CompareAndSwapINode : public LoadStoreConditionalNode {
 769 public:
 770   CompareAndSwapINode( Node *c, Node *mem, Node *adr, Node *val, Node *ex) : LoadStoreConditionalNode(c, mem, adr, val, ex) { }
 771   virtual int Opcode() const;
 772 };
 773 
 774 
 775 //------------------------------CompareAndSwapPNode---------------------------
 776 class CompareAndSwapPNode : public LoadStoreConditionalNode {
 777 public:
 778   CompareAndSwapPNode( Node *c, Node *mem, Node *adr, Node *val, Node *ex) : LoadStoreConditionalNode(c, mem, adr, val, ex) { }
 779   virtual int Opcode() const;
 780 };
 781 
 782 //------------------------------CompareAndSwapNNode---------------------------
 783 class CompareAndSwapNNode : public LoadStoreConditionalNode {
 784 public:
 785   CompareAndSwapNNode( Node *c, Node *mem, Node *adr, Node *val, Node *ex) : LoadStoreConditionalNode(c, mem, adr, val, ex) { }
 786   virtual int Opcode() const;
 787 };
 788 
 789 //------------------------------GetAndAddINode---------------------------
 790 class GetAndAddINode : public LoadStoreNode {
 791 public:
 792   GetAndAddINode( Node *c, Node *mem, Node *adr, Node *val, const TypePtr* at ) : LoadStoreNode(c, mem, adr, val, at, TypeInt::INT, 4) { }
 793   virtual int Opcode() const;
 794 };
 795 
 796 //------------------------------GetAndAddLNode---------------------------
 797 class GetAndAddLNode : public LoadStoreNode {
 798 public:
 799   GetAndAddLNode( Node *c, Node *mem, Node *adr, Node *val, const TypePtr* at ) : LoadStoreNode(c, mem, adr, val, at, TypeLong::LONG, 4) { }
 800   virtual int Opcode() const;
 801 };
 802 
 803 
 804 //------------------------------GetAndSetINode---------------------------
 805 class GetAndSetINode : public LoadStoreNode {
 806 public:
 807   GetAndSetINode( Node *c, Node *mem, Node *adr, Node *val, const TypePtr* at ) : LoadStoreNode(c, mem, adr, val, at, TypeInt::INT, 4) { }
 808   virtual int Opcode() const;
 809 };
 810 
 811 //------------------------------GetAndSetINode---------------------------
 812 class GetAndSetLNode : public LoadStoreNode {
 813 public:
 814   GetAndSetLNode( Node *c, Node *mem, Node *adr, Node *val, const TypePtr* at ) : LoadStoreNode(c, mem, adr, val, at, TypeLong::LONG, 4) { }
 815   virtual int Opcode() const;
 816 };
 817 
 818 //------------------------------GetAndSetPNode---------------------------
 819 class GetAndSetPNode : public LoadStoreNode {
 820 public:
 821   GetAndSetPNode( Node *c, Node *mem, Node *adr, Node *val, const TypePtr* at, const Type* t ) : LoadStoreNode(c, mem, adr, val, at, t, 4) { }
 822   virtual int Opcode() const;
 823 };
 824 
 825 //------------------------------GetAndSetNNode---------------------------
 826 class GetAndSetNNode : public LoadStoreNode {
 827 public:
 828   GetAndSetNNode( Node *c, Node *mem, Node *adr, Node *val, const TypePtr* at, const Type* t ) : LoadStoreNode(c, mem, adr, val, at, t, 4) { }
 829   virtual int Opcode() const;
 830 };
 831 
 832 //------------------------------ClearArray-------------------------------------
 833 class ClearArrayNode: public Node {
 834 public:
 835   ClearArrayNode( Node *ctrl, Node *arymem, Node *word_cnt, Node *base )
 836     : Node(ctrl,arymem,word_cnt,base) {
 837     init_class_id(Class_ClearArray);
 838   }
 839   virtual int         Opcode() const;
 840   virtual const Type *bottom_type() const { return Type::MEMORY; }
 841   // ClearArray modifies array elements, and so affects only the
 842   // array memory addressed by the bottom_type of its base address.
 843   virtual const class TypePtr *adr_type() const;
 844   virtual Node *Identity( PhaseTransform *phase );
 845   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
 846   virtual uint match_edge(uint idx) const;
 847 
 848   // Clear the given area of an object or array.
 849   // The start offset must always be aligned mod BytesPerInt.
 850   // The end offset must always be aligned mod BytesPerLong.
 851   // Return the new memory.
 852   static Node* clear_memory(Node* control, Node* mem, Node* dest,
 853                             intptr_t start_offset,
 854                             intptr_t end_offset,
 855                             PhaseGVN* phase);
 856   static Node* clear_memory(Node* control, Node* mem, Node* dest,
 857                             intptr_t start_offset,
 858                             Node* end_offset,
 859                             PhaseGVN* phase);
 860   static Node* clear_memory(Node* control, Node* mem, Node* dest,
 861                             Node* start_offset,
 862                             Node* end_offset,
 863                             PhaseGVN* phase);
 864   // Return allocation input memory edge if it is different instance
 865   // or itself if it is the one we are looking for.
 866   static bool step_through(Node** np, uint instance_id, PhaseTransform* phase);
 867 };
 868 
 869 //------------------------------MemBar-----------------------------------------
 870 // There are different flavors of Memory Barriers to match the Java Memory
 871 // Model.  Monitor-enter and volatile-load act as Aquires: no following ref
 872 // can be moved to before them.  We insert a MemBar-Acquire after a FastLock or
 873 // volatile-load.  Monitor-exit and volatile-store act as Release: no
 874 // preceding ref can be moved to after them.  We insert a MemBar-Release
 875 // before a FastUnlock or volatile-store.  All volatiles need to be
 876 // serialized, so we follow all volatile-stores with a MemBar-Volatile to
 877 // separate it from any following volatile-load.
 878 class MemBarNode: public MultiNode {
 879   virtual uint hash() const ;                  // { return NO_HASH; }
 880   virtual uint cmp( const Node &n ) const ;    // Always fail, except on self
 881 
 882   virtual uint size_of() const { return sizeof(*this); }
 883   // Memory type this node is serializing.  Usually either rawptr or bottom.
 884   const TypePtr* _adr_type;
 885 
 886 public:
 887   enum {
 888     Precedent = TypeFunc::Parms  // optional edge to force precedence
 889   };
 890   MemBarNode(Compile* C, int alias_idx, Node* precedent);
 891   virtual int Opcode() const = 0;
 892   virtual const class TypePtr *adr_type() const { return _adr_type; }
 893   virtual const Type *Value( PhaseTransform *phase ) const;
 894   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
 895   virtual uint match_edge(uint idx) const { return 0; }
 896   virtual const Type *bottom_type() const { return TypeTuple::MEMBAR; }
 897   virtual Node *match( const ProjNode *proj, const Matcher *m );
 898   // Factory method.  Builds a wide or narrow membar.
 899   // Optional 'precedent' becomes an extra edge if not null.
 900   static MemBarNode* make(Compile* C, int opcode,
 901                           int alias_idx = Compile::AliasIdxBot,
 902                           Node* precedent = NULL);
 903 };
 904 
 905 // "Acquire" - no following ref can move before (but earlier refs can
 906 // follow, like an early Load stalled in cache).  Requires multi-cpu
 907 // visibility.  Inserted after a volatile load.
 908 class MemBarAcquireNode: public MemBarNode {
 909 public:
 910   MemBarAcquireNode(Compile* C, int alias_idx, Node* precedent)
 911     : MemBarNode(C, alias_idx, precedent) {}
 912   virtual int Opcode() const;
 913 };
 914 
 915 // "Acquire" - no following ref can move before (but earlier refs can
 916 // follow, like an early Load stalled in cache).  Requires multi-cpu
 917 // visibility.  Inserted independ of any load, as required
 918 // for intrinsic sun.misc.Unsafe.loadFence().
 919 class LoadFenceNode: public MemBarNode {
 920 public:
 921   LoadFenceNode(Compile* C, int alias_idx, Node* precedent)
 922     : MemBarNode(C, alias_idx, precedent) {}
 923   virtual int Opcode() const;
 924 };
 925 
 926 // "Release" - no earlier ref can move after (but later refs can move
 927 // up, like a speculative pipelined cache-hitting Load).  Requires
 928 // multi-cpu visibility.  Inserted before a volatile store.
 929 class MemBarReleaseNode: public MemBarNode {
 930 public:
 931   MemBarReleaseNode(Compile* C, int alias_idx, Node* precedent)
 932     : MemBarNode(C, alias_idx, precedent) {}
 933   virtual int Opcode() const;
 934 };
 935 
 936 // "Release" - no earlier ref can move after (but later refs can move
 937 // up, like a speculative pipelined cache-hitting Load).  Requires
 938 // multi-cpu visibility.  Inserted independent of any store, as required
 939 // for intrinsic sun.misc.Unsafe.storeFence().
 940 class StoreFenceNode: public MemBarNode {
 941 public:
 942   StoreFenceNode(Compile* C, int alias_idx, Node* precedent)
 943     : MemBarNode(C, alias_idx, precedent) {}
 944   virtual int Opcode() const;
 945 };
 946 
 947 // "Acquire" - no following ref can move before (but earlier refs can
 948 // follow, like an early Load stalled in cache).  Requires multi-cpu
 949 // visibility.  Inserted after a FastLock.
 950 class MemBarAcquireLockNode: public MemBarNode {
 951 public:
 952   MemBarAcquireLockNode(Compile* C, int alias_idx, Node* precedent)
 953     : MemBarNode(C, alias_idx, precedent) {}
 954   virtual int Opcode() const;
 955 };
 956 
 957 // "Release" - no earlier ref can move after (but later refs can move
 958 // up, like a speculative pipelined cache-hitting Load).  Requires
 959 // multi-cpu visibility.  Inserted before a FastUnLock.
 960 class MemBarReleaseLockNode: public MemBarNode {
 961 public:
 962   MemBarReleaseLockNode(Compile* C, int alias_idx, Node* precedent)
 963     : MemBarNode(C, alias_idx, precedent) {}
 964   virtual int Opcode() const;
 965 };
 966 
 967 class MemBarStoreStoreNode: public MemBarNode {
 968 public:
 969   MemBarStoreStoreNode(Compile* C, int alias_idx, Node* precedent)
 970     : MemBarNode(C, alias_idx, precedent) {
 971     init_class_id(Class_MemBarStoreStore);
 972   }
 973   virtual int Opcode() const;
 974 };
 975 
 976 // Ordering between a volatile store and a following volatile load.
 977 // Requires multi-CPU visibility?
 978 class MemBarVolatileNode: public MemBarNode {
 979 public:
 980   MemBarVolatileNode(Compile* C, int alias_idx, Node* precedent)
 981     : MemBarNode(C, alias_idx, precedent) {}
 982   virtual int Opcode() const;
 983 };
 984 
 985 // Ordering within the same CPU.  Used to order unsafe memory references
 986 // inside the compiler when we lack alias info.  Not needed "outside" the
 987 // compiler because the CPU does all the ordering for us.
 988 class MemBarCPUOrderNode: public MemBarNode {
 989 public:
 990   MemBarCPUOrderNode(Compile* C, int alias_idx, Node* precedent)
 991     : MemBarNode(C, alias_idx, precedent) {}
 992   virtual int Opcode() const;
 993   virtual uint ideal_reg() const { return 0; } // not matched in the AD file
 994 };
 995 
 996 // Isolation of object setup after an AllocateNode and before next safepoint.
 997 // (See comment in memnode.cpp near InitializeNode::InitializeNode for semantics.)
 998 class InitializeNode: public MemBarNode {
 999   friend class AllocateNode;
1000 
1001   enum {
1002     Incomplete    = 0,
1003     Complete      = 1,
1004     WithArraycopy = 2
1005   };
1006   int _is_complete;
1007 
1008   bool _does_not_escape;
1009 
1010 public:
1011   enum {
1012     Control    = TypeFunc::Control,
1013     Memory     = TypeFunc::Memory,     // MergeMem for states affected by this op
1014     RawAddress = TypeFunc::Parms+0,    // the newly-allocated raw address
1015     RawStores  = TypeFunc::Parms+1     // zero or more stores (or TOP)
1016   };
1017 
1018   InitializeNode(Compile* C, int adr_type, Node* rawoop);
1019   virtual int Opcode() const;
1020   virtual uint size_of() const { return sizeof(*this); }
1021   virtual uint ideal_reg() const { return 0; } // not matched in the AD file
1022   virtual const RegMask &in_RegMask(uint) const;  // mask for RawAddress
1023 
1024   // Manage incoming memory edges via a MergeMem on in(Memory):
1025   Node* memory(uint alias_idx);
1026 
1027   // The raw memory edge coming directly from the Allocation.
1028   // The contents of this memory are *always* all-zero-bits.
1029   Node* zero_memory() { return memory(Compile::AliasIdxRaw); }
1030 
1031   // Return the corresponding allocation for this initialization (or null if none).
1032   // (Note: Both InitializeNode::allocation and AllocateNode::initialization
1033   // are defined in graphKit.cpp, which sets up the bidirectional relation.)
1034   AllocateNode* allocation();
1035 
1036   // Anything other than zeroing in this init?
1037   bool is_non_zero();
1038 
1039   // An InitializeNode must completed before macro expansion is done.
1040   // Completion requires that the AllocateNode must be followed by
1041   // initialization of the new memory to zero, then to any initializers.
1042   bool is_complete() { return _is_complete != Incomplete; }
1043   bool is_complete_with_arraycopy() { return (_is_complete & WithArraycopy) != 0; }
1044 
1045   // Mark complete.  (Must not yet be complete.)
1046   void set_complete(PhaseGVN* phase);
1047   void set_complete_with_arraycopy() { _is_complete = Complete | WithArraycopy; }
1048 
1049   bool does_not_escape() { return _does_not_escape; }
1050   void set_does_not_escape() { _does_not_escape = true; }
1051 
1052 #ifdef ASSERT
1053   // ensure all non-degenerate stores are ordered and non-overlapping
1054   bool stores_are_sane(PhaseTransform* phase);
1055 #endif //ASSERT
1056 
1057   // See if this store can be captured; return offset where it initializes.
1058   // Return 0 if the store cannot be moved (any sort of problem).
1059   intptr_t can_capture_store(StoreNode* st, PhaseTransform* phase, bool can_reshape);
1060 
1061   // Capture another store; reformat it to write my internal raw memory.
1062   // Return the captured copy, else NULL if there is some sort of problem.
1063   Node* capture_store(StoreNode* st, intptr_t start, PhaseTransform* phase, bool can_reshape);
1064 
1065   // Find captured store which corresponds to the range [start..start+size).
1066   // Return my own memory projection (meaning the initial zero bits)
1067   // if there is no such store.  Return NULL if there is a problem.
1068   Node* find_captured_store(intptr_t start, int size_in_bytes, PhaseTransform* phase);
1069 
1070   // Called when the associated AllocateNode is expanded into CFG.
1071   Node* complete_stores(Node* rawctl, Node* rawmem, Node* rawptr,
1072                         intptr_t header_size, Node* size_in_bytes,
1073                         PhaseGVN* phase);
1074 
1075  private:
1076   void remove_extra_zeroes();
1077 
1078   // Find out where a captured store should be placed (or already is placed).
1079   int captured_store_insertion_point(intptr_t start, int size_in_bytes,
1080                                      PhaseTransform* phase);
1081 
1082   static intptr_t get_store_offset(Node* st, PhaseTransform* phase);
1083 
1084   Node* make_raw_address(intptr_t offset, PhaseTransform* phase);
1085 
1086   bool detect_init_independence(Node* n, int& count);
1087 
1088   void coalesce_subword_stores(intptr_t header_size, Node* size_in_bytes,
1089                                PhaseGVN* phase);
1090 
1091   intptr_t find_next_fullword_store(uint i, PhaseGVN* phase);
1092 };
1093 
1094 //------------------------------MergeMem---------------------------------------
1095 // (See comment in memnode.cpp near MergeMemNode::MergeMemNode for semantics.)
1096 class MergeMemNode: public Node {
1097   virtual uint hash() const ;                  // { return NO_HASH; }
1098   virtual uint cmp( const Node &n ) const ;    // Always fail, except on self
1099   friend class MergeMemStream;
1100   MergeMemNode(Node* def);  // clients use MergeMemNode::make
1101 
1102 public:
1103   // If the input is a whole memory state, clone it with all its slices intact.
1104   // Otherwise, make a new memory state with just that base memory input.
1105   // In either case, the result is a newly created MergeMem.
1106   static MergeMemNode* make(Compile* C, Node* base_memory);
1107 
1108   virtual int Opcode() const;
1109   virtual Node *Identity( PhaseTransform *phase );
1110   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
1111   virtual uint ideal_reg() const { return NotAMachineReg; }
1112   virtual uint match_edge(uint idx) const { return 0; }
1113   virtual const RegMask &out_RegMask() const;
1114   virtual const Type *bottom_type() const { return Type::MEMORY; }
1115   virtual const TypePtr *adr_type() const { return TypePtr::BOTTOM; }
1116   // sparse accessors
1117   // Fetch the previously stored "set_memory_at", or else the base memory.
1118   // (Caller should clone it if it is a phi-nest.)
1119   Node* memory_at(uint alias_idx) const;
1120   // set the memory, regardless of its previous value
1121   void set_memory_at(uint alias_idx, Node* n);
1122   // the "base" is the memory that provides the non-finite support
1123   Node* base_memory() const       { return in(Compile::AliasIdxBot); }
1124   // warning: setting the base can implicitly set any of the other slices too
1125   void set_base_memory(Node* def);
1126   // sentinel value which denotes a copy of the base memory:
1127   Node*   empty_memory() const    { return in(Compile::AliasIdxTop); }
1128   static Node* make_empty_memory(); // where the sentinel comes from
1129   bool is_empty_memory(Node* n) const { assert((n == empty_memory()) == n->is_top(), "sanity"); return n->is_top(); }
1130   // hook for the iterator, to perform any necessary setup
1131   void iteration_setup(const MergeMemNode* other = NULL);
1132   // push sentinels until I am at least as long as the other (semantic no-op)
1133   void grow_to_match(const MergeMemNode* other);
1134   bool verify_sparse() const PRODUCT_RETURN0;
1135 #ifndef PRODUCT
1136   virtual void dump_spec(outputStream *st) const;
1137 #endif
1138 };
1139 
1140 class MergeMemStream : public StackObj {
1141  private:
1142   MergeMemNode*       _mm;
1143   const MergeMemNode* _mm2;  // optional second guy, contributes non-empty iterations
1144   Node*               _mm_base;  // loop-invariant base memory of _mm
1145   int                 _idx;
1146   int                 _cnt;
1147   Node*               _mem;
1148   Node*               _mem2;
1149   int                 _cnt2;
1150 
1151   void init(MergeMemNode* mm, const MergeMemNode* mm2 = NULL) {
1152     // subsume_node will break sparseness at times, whenever a memory slice
1153     // folds down to a copy of the base ("fat") memory.  In such a case,
1154     // the raw edge will update to base, although it should be top.
1155     // This iterator will recognize either top or base_memory as an
1156     // "empty" slice.  See is_empty, is_empty2, and next below.
1157     //
1158     // The sparseness property is repaired in MergeMemNode::Ideal.
1159     // As long as access to a MergeMem goes through this iterator
1160     // or the memory_at accessor, flaws in the sparseness will
1161     // never be observed.
1162     //
1163     // Also, iteration_setup repairs sparseness.
1164     assert(mm->verify_sparse(), "please, no dups of base");
1165     assert(mm2==NULL || mm2->verify_sparse(), "please, no dups of base");
1166 
1167     _mm  = mm;
1168     _mm_base = mm->base_memory();
1169     _mm2 = mm2;
1170     _cnt = mm->req();
1171     _idx = Compile::AliasIdxBot-1; // start at the base memory
1172     _mem = NULL;
1173     _mem2 = NULL;
1174   }
1175 
1176 #ifdef ASSERT
1177   Node* check_memory() const {
1178     if (at_base_memory())
1179       return _mm->base_memory();
1180     else if ((uint)_idx < _mm->req() && !_mm->in(_idx)->is_top())
1181       return _mm->memory_at(_idx);
1182     else
1183       return _mm_base;
1184   }
1185   Node* check_memory2() const {
1186     return at_base_memory()? _mm2->base_memory(): _mm2->memory_at(_idx);
1187   }
1188 #endif
1189 
1190   static bool match_memory(Node* mem, const MergeMemNode* mm, int idx) PRODUCT_RETURN0;
1191   void assert_synch() const {
1192     assert(!_mem || _idx >= _cnt || match_memory(_mem, _mm, _idx),
1193            "no side-effects except through the stream");
1194   }
1195 
1196  public:
1197 
1198   // expected usages:
1199   // for (MergeMemStream mms(mem->is_MergeMem()); next_non_empty(); ) { ... }
1200   // for (MergeMemStream mms(mem1, mem2); next_non_empty2(); ) { ... }
1201 
1202   // iterate over one merge
1203   MergeMemStream(MergeMemNode* mm) {
1204     mm->iteration_setup();
1205     init(mm);
1206     debug_only(_cnt2 = 999);
1207   }
1208   // iterate in parallel over two merges
1209   // only iterates through non-empty elements of mm2
1210   MergeMemStream(MergeMemNode* mm, const MergeMemNode* mm2) {
1211     assert(mm2, "second argument must be a MergeMem also");
1212     ((MergeMemNode*)mm2)->iteration_setup();  // update hidden state
1213     mm->iteration_setup(mm2);
1214     init(mm, mm2);
1215     _cnt2 = mm2->req();
1216   }
1217 #ifdef ASSERT
1218   ~MergeMemStream() {
1219     assert_synch();
1220   }
1221 #endif
1222 
1223   MergeMemNode* all_memory() const {
1224     return _mm;
1225   }
1226   Node* base_memory() const {
1227     assert(_mm_base == _mm->base_memory(), "no update to base memory, please");
1228     return _mm_base;
1229   }
1230   const MergeMemNode* all_memory2() const {
1231     assert(_mm2 != NULL, "");
1232     return _mm2;
1233   }
1234   bool at_base_memory() const {
1235     return _idx == Compile::AliasIdxBot;
1236   }
1237   int alias_idx() const {
1238     assert(_mem, "must call next 1st");
1239     return _idx;
1240   }
1241 
1242   const TypePtr* adr_type() const {
1243     return Compile::current()->get_adr_type(alias_idx());
1244   }
1245 
1246   const TypePtr* adr_type(Compile* C) const {
1247     return C->get_adr_type(alias_idx());
1248   }
1249   bool is_empty() const {
1250     assert(_mem, "must call next 1st");
1251     assert(_mem->is_top() == (_mem==_mm->empty_memory()), "correct sentinel");
1252     return _mem->is_top();
1253   }
1254   bool is_empty2() const {
1255     assert(_mem2, "must call next 1st");
1256     assert(_mem2->is_top() == (_mem2==_mm2->empty_memory()), "correct sentinel");
1257     return _mem2->is_top();
1258   }
1259   Node* memory() const {
1260     assert(!is_empty(), "must not be empty");
1261     assert_synch();
1262     return _mem;
1263   }
1264   // get the current memory, regardless of empty or non-empty status
1265   Node* force_memory() const {
1266     assert(!is_empty() || !at_base_memory(), "");
1267     // Use _mm_base to defend against updates to _mem->base_memory().
1268     Node *mem = _mem->is_top() ? _mm_base : _mem;
1269     assert(mem == check_memory(), "");
1270     return mem;
1271   }
1272   Node* memory2() const {
1273     assert(_mem2 == check_memory2(), "");
1274     return _mem2;
1275   }
1276   void set_memory(Node* mem) {
1277     if (at_base_memory()) {
1278       // Note that this does not change the invariant _mm_base.
1279       _mm->set_base_memory(mem);
1280     } else {
1281       _mm->set_memory_at(_idx, mem);
1282     }
1283     _mem = mem;
1284     assert_synch();
1285   }
1286 
1287   // Recover from a side effect to the MergeMemNode.
1288   void set_memory() {
1289     _mem = _mm->in(_idx);
1290   }
1291 
1292   bool next()  { return next(false); }
1293   bool next2() { return next(true); }
1294 
1295   bool next_non_empty()  { return next_non_empty(false); }
1296   bool next_non_empty2() { return next_non_empty(true); }
1297   // next_non_empty2 can yield states where is_empty() is true
1298 
1299  private:
1300   // find the next item, which might be empty
1301   bool next(bool have_mm2) {
1302     assert((_mm2 != NULL) == have_mm2, "use other next");
1303     assert_synch();
1304     if (++_idx < _cnt) {
1305       // Note:  This iterator allows _mm to be non-sparse.
1306       // It behaves the same whether _mem is top or base_memory.
1307       _mem = _mm->in(_idx);
1308       if (have_mm2)
1309         _mem2 = _mm2->in((_idx < _cnt2) ? _idx : Compile::AliasIdxTop);
1310       return true;
1311     }
1312     return false;
1313   }
1314 
1315   // find the next non-empty item
1316   bool next_non_empty(bool have_mm2) {
1317     while (next(have_mm2)) {
1318       if (!is_empty()) {
1319         // make sure _mem2 is filled in sensibly
1320         if (have_mm2 && _mem2->is_top())  _mem2 = _mm2->base_memory();
1321         return true;
1322       } else if (have_mm2 && !is_empty2()) {
1323         return true;   // is_empty() == true
1324       }
1325     }
1326     return false;
1327   }
1328 };
1329 
1330 //------------------------------Prefetch---------------------------------------
1331 
1332 // Non-faulting prefetch load.  Prefetch for many reads.
1333 class PrefetchReadNode : public Node {
1334 public:
1335   PrefetchReadNode(Node *abio, Node *adr) : Node(0,abio,adr) {}
1336   virtual int Opcode() const;
1337   virtual uint ideal_reg() const { return NotAMachineReg; }
1338   virtual uint match_edge(uint idx) const { return idx==2; }
1339   virtual const Type *bottom_type() const { return Type::ABIO; }
1340 };
1341 
1342 // Non-faulting prefetch load.  Prefetch for many reads & many writes.
1343 class PrefetchWriteNode : public Node {
1344 public:
1345   PrefetchWriteNode(Node *abio, Node *adr) : Node(0,abio,adr) {}
1346   virtual int Opcode() const;
1347   virtual uint ideal_reg() const { return NotAMachineReg; }
1348   virtual uint match_edge(uint idx) const { return idx==2; }
1349   virtual const Type *bottom_type() const { return Type::ABIO; }
1350 };
1351 
1352 // Allocation prefetch which may fault, TLAB size have to be adjusted.
1353 class PrefetchAllocationNode : public Node {
1354 public:
1355   PrefetchAllocationNode(Node *mem, Node *adr) : Node(0,mem,adr) {}
1356   virtual int Opcode() const;
1357   virtual uint ideal_reg() const { return NotAMachineReg; }
1358   virtual uint match_edge(uint idx) const { return idx==2; }
1359   virtual const Type *bottom_type() const { return ( AllocatePrefetchStyle == 3 ) ? Type::MEMORY : Type::ABIO; }
1360 };
1361 
1362 #endif // SHARE_VM_OPTO_MEMNODE_HPP
--- EOF ---