Thu, 19 Mar 2009 09:13:24 -0700
Merge
1 /*
2 * Copyright 1997-2009 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 * have any questions.
22 *
23 */
25 // Portions of code courtesy of Clifford Click
27 class MultiNode;
28 class PhaseCCP;
29 class PhaseTransform;
31 //------------------------------MemNode----------------------------------------
32 // Load or Store, possibly throwing a NULL pointer exception
33 class MemNode : public Node {
34 protected:
35 #ifdef ASSERT
36 const TypePtr* _adr_type; // What kind of memory is being addressed?
37 #endif
38 virtual uint size_of() const; // Size is bigger (ASSERT only)
39 public:
40 enum { Control, // When is it safe to do this load?
41 Memory, // Chunk of memory is being loaded from
42 Address, // Actually address, derived from base
43 ValueIn, // Value to store
44 OopStore // Preceeding oop store, only in StoreCM
45 };
46 protected:
47 MemNode( Node *c0, Node *c1, Node *c2, const TypePtr* at )
48 : Node(c0,c1,c2 ) {
49 init_class_id(Class_Mem);
50 debug_only(_adr_type=at; adr_type();)
51 }
52 MemNode( Node *c0, Node *c1, Node *c2, const TypePtr* at, Node *c3 )
53 : Node(c0,c1,c2,c3) {
54 init_class_id(Class_Mem);
55 debug_only(_adr_type=at; adr_type();)
56 }
57 MemNode( Node *c0, Node *c1, Node *c2, const TypePtr* at, Node *c3, Node *c4)
58 : Node(c0,c1,c2,c3,c4) {
59 init_class_id(Class_Mem);
60 debug_only(_adr_type=at; adr_type();)
61 }
63 public:
64 // Helpers for the optimizer. Documented in memnode.cpp.
65 static bool detect_ptr_independence(Node* p1, AllocateNode* a1,
66 Node* p2, AllocateNode* a2,
67 PhaseTransform* phase);
68 static bool adr_phi_is_loop_invariant(Node* adr_phi, Node* cast);
70 static Node *optimize_simple_memory_chain(Node *mchain, const TypePtr *t_adr, PhaseGVN *phase);
71 static Node *optimize_memory_chain(Node *mchain, const TypePtr *t_adr, PhaseGVN *phase);
72 // This one should probably be a phase-specific function:
73 static bool all_controls_dominate(Node* dom, Node* sub);
75 // Find any cast-away of null-ness and keep its control.
76 static Node *Ideal_common_DU_postCCP( PhaseCCP *ccp, Node* n, Node* adr );
77 virtual Node *Ideal_DU_postCCP( PhaseCCP *ccp );
79 virtual const class TypePtr *adr_type() const; // returns bottom_type of address
81 // Shared code for Ideal methods:
82 Node *Ideal_common(PhaseGVN *phase, bool can_reshape); // Return -1 for short-circuit NULL.
84 // Helper function for adr_type() implementations.
85 static const TypePtr* calculate_adr_type(const Type* t, const TypePtr* cross_check = NULL);
87 // Raw access function, to allow copying of adr_type efficiently in
88 // product builds and retain the debug info for debug builds.
89 const TypePtr *raw_adr_type() const {
90 #ifdef ASSERT
91 return _adr_type;
92 #else
93 return 0;
94 #endif
95 }
97 // Map a load or store opcode to its corresponding store opcode.
98 // (Return -1 if unknown.)
99 virtual int store_Opcode() const { return -1; }
101 // What is the type of the value in memory? (T_VOID mean "unspecified".)
102 virtual BasicType memory_type() const = 0;
103 virtual int memory_size() const {
104 #ifdef ASSERT
105 return type2aelembytes(memory_type(), true);
106 #else
107 return type2aelembytes(memory_type());
108 #endif
109 }
111 // Search through memory states which precede this node (load or store).
112 // Look for an exact match for the address, with no intervening
113 // aliased stores.
114 Node* find_previous_store(PhaseTransform* phase);
116 // Can this node (load or store) accurately see a stored value in
117 // the given memory state? (The state may or may not be in(Memory).)
118 Node* can_see_stored_value(Node* st, PhaseTransform* phase) const;
120 #ifndef PRODUCT
121 static void dump_adr_type(const Node* mem, const TypePtr* adr_type, outputStream *st);
122 virtual void dump_spec(outputStream *st) const;
123 #endif
124 };
126 //------------------------------LoadNode---------------------------------------
127 // Load value; requires Memory and Address
128 class LoadNode : public MemNode {
129 protected:
130 virtual uint cmp( const Node &n ) const;
131 virtual uint size_of() const; // Size is bigger
132 const Type* const _type; // What kind of value is loaded?
133 public:
135 LoadNode( Node *c, Node *mem, Node *adr, const TypePtr* at, const Type *rt )
136 : MemNode(c,mem,adr,at), _type(rt) {
137 init_class_id(Class_Load);
138 }
140 // Polymorphic factory method:
141 static Node* make( PhaseGVN& gvn, Node *c, Node *mem, Node *adr,
142 const TypePtr* at, const Type *rt, BasicType bt );
144 virtual uint hash() const; // Check the type
146 // Handle algebraic identities here. If we have an identity, return the Node
147 // we are equivalent to. We look for Load of a Store.
148 virtual Node *Identity( PhaseTransform *phase );
150 // If the load is from Field memory and the pointer is non-null, we can
151 // zero out the control input.
152 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
154 // Split instance field load through Phi.
155 Node* split_through_phi(PhaseGVN *phase);
157 // Recover original value from boxed values
158 Node *eliminate_autobox(PhaseGVN *phase);
160 // Compute a new Type for this node. Basically we just do the pre-check,
161 // then call the virtual add() to set the type.
162 virtual const Type *Value( PhaseTransform *phase ) const;
164 // Common methods for LoadKlass and LoadNKlass nodes.
165 const Type *klass_value_common( PhaseTransform *phase ) const;
166 Node *klass_identity_common( PhaseTransform *phase );
168 virtual uint ideal_reg() const;
169 virtual const Type *bottom_type() const;
170 // Following method is copied from TypeNode:
171 void set_type(const Type* t) {
172 assert(t != NULL, "sanity");
173 debug_only(uint check_hash = (VerifyHashTableKeys && _hash_lock) ? hash() : NO_HASH);
174 *(const Type**)&_type = t; // cast away const-ness
175 // If this node is in the hash table, make sure it doesn't need a rehash.
176 assert(check_hash == NO_HASH || check_hash == hash(), "type change must preserve hash code");
177 }
178 const Type* type() const { assert(_type != NULL, "sanity"); return _type; };
180 // Do not match memory edge
181 virtual uint match_edge(uint idx) const;
183 // Map a load opcode to its corresponding store opcode.
184 virtual int store_Opcode() const = 0;
186 // Check if the load's memory input is a Phi node with the same control.
187 bool is_instance_field_load_with_local_phi(Node* ctrl);
189 #ifndef PRODUCT
190 virtual void dump_spec(outputStream *st) const;
191 #endif
192 protected:
193 const Type* load_array_final_field(const TypeKlassPtr *tkls,
194 ciKlass* klass) const;
195 };
197 //------------------------------LoadBNode--------------------------------------
198 // Load a byte (8bits signed) from memory
199 class LoadBNode : public LoadNode {
200 public:
201 LoadBNode( Node *c, Node *mem, Node *adr, const TypePtr* at, const TypeInt *ti = TypeInt::BYTE )
202 : LoadNode(c,mem,adr,at,ti) {}
203 virtual int Opcode() const;
204 virtual uint ideal_reg() const { return Op_RegI; }
205 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
206 virtual int store_Opcode() const { return Op_StoreB; }
207 virtual BasicType memory_type() const { return T_BYTE; }
208 };
210 //------------------------------LoadUBNode-------------------------------------
211 // Load a unsigned byte (8bits unsigned) from memory
212 class LoadUBNode : public LoadNode {
213 public:
214 LoadUBNode(Node* c, Node* mem, Node* adr, const TypePtr* at, const TypeInt* ti = TypeInt::UBYTE )
215 : LoadNode(c, mem, adr, at, ti) {}
216 virtual int Opcode() const;
217 virtual uint ideal_reg() const { return Op_RegI; }
218 virtual Node* Ideal(PhaseGVN *phase, bool can_reshape);
219 virtual int store_Opcode() const { return Op_StoreB; }
220 virtual BasicType memory_type() const { return T_BYTE; }
221 };
223 //------------------------------LoadUSNode-------------------------------------
224 // Load an unsigned short/char (16bits unsigned) from memory
225 class LoadUSNode : public LoadNode {
226 public:
227 LoadUSNode( Node *c, Node *mem, Node *adr, const TypePtr* at, const TypeInt *ti = TypeInt::CHAR )
228 : LoadNode(c,mem,adr,at,ti) {}
229 virtual int Opcode() const;
230 virtual uint ideal_reg() const { return Op_RegI; }
231 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
232 virtual int store_Opcode() const { return Op_StoreC; }
233 virtual BasicType memory_type() const { return T_CHAR; }
234 };
236 //------------------------------LoadINode--------------------------------------
237 // Load an integer from memory
238 class LoadINode : public LoadNode {
239 public:
240 LoadINode( Node *c, Node *mem, Node *adr, const TypePtr* at, const TypeInt *ti = TypeInt::INT )
241 : LoadNode(c,mem,adr,at,ti) {}
242 virtual int Opcode() const;
243 virtual uint ideal_reg() const { return Op_RegI; }
244 virtual int store_Opcode() const { return Op_StoreI; }
245 virtual BasicType memory_type() const { return T_INT; }
246 };
248 //------------------------------LoadUI2LNode-----------------------------------
249 // Load an unsigned integer into long from memory
250 class LoadUI2LNode : public LoadNode {
251 public:
252 LoadUI2LNode(Node* c, Node* mem, Node* adr, const TypePtr* at, const TypeLong* t = TypeLong::UINT)
253 : LoadNode(c, mem, adr, at, t) {}
254 virtual int Opcode() const;
255 virtual uint ideal_reg() const { return Op_RegL; }
256 virtual int store_Opcode() const { return Op_StoreL; }
257 virtual BasicType memory_type() const { return T_LONG; }
258 };
260 //------------------------------LoadRangeNode----------------------------------
261 // Load an array length from the array
262 class LoadRangeNode : public LoadINode {
263 public:
264 LoadRangeNode( Node *c, Node *mem, Node *adr, const TypeInt *ti = TypeInt::POS )
265 : LoadINode(c,mem,adr,TypeAryPtr::RANGE,ti) {}
266 virtual int Opcode() const;
267 virtual const Type *Value( PhaseTransform *phase ) const;
268 virtual Node *Identity( PhaseTransform *phase );
269 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
270 };
272 //------------------------------LoadLNode--------------------------------------
273 // Load a long from memory
274 class LoadLNode : public LoadNode {
275 virtual uint hash() const { return LoadNode::hash() + _require_atomic_access; }
276 virtual uint cmp( const Node &n ) const {
277 return _require_atomic_access == ((LoadLNode&)n)._require_atomic_access
278 && LoadNode::cmp(n);
279 }
280 virtual uint size_of() const { return sizeof(*this); }
281 const bool _require_atomic_access; // is piecewise load forbidden?
283 public:
284 LoadLNode( Node *c, Node *mem, Node *adr, const TypePtr* at,
285 const TypeLong *tl = TypeLong::LONG,
286 bool require_atomic_access = false )
287 : LoadNode(c,mem,adr,at,tl)
288 , _require_atomic_access(require_atomic_access)
289 {}
290 virtual int Opcode() const;
291 virtual uint ideal_reg() const { return Op_RegL; }
292 virtual int store_Opcode() const { return Op_StoreL; }
293 virtual BasicType memory_type() const { return T_LONG; }
294 bool require_atomic_access() { return _require_atomic_access; }
295 static LoadLNode* make_atomic(Compile *C, Node* ctl, Node* mem, Node* adr, const TypePtr* adr_type, const Type* rt);
296 #ifndef PRODUCT
297 virtual void dump_spec(outputStream *st) const {
298 LoadNode::dump_spec(st);
299 if (_require_atomic_access) st->print(" Atomic!");
300 }
301 #endif
302 };
304 //------------------------------LoadL_unalignedNode----------------------------
305 // Load a long from unaligned memory
306 class LoadL_unalignedNode : public LoadLNode {
307 public:
308 LoadL_unalignedNode( Node *c, Node *mem, Node *adr, const TypePtr* at )
309 : LoadLNode(c,mem,adr,at) {}
310 virtual int Opcode() const;
311 };
313 //------------------------------LoadFNode--------------------------------------
314 // Load a float (64 bits) from memory
315 class LoadFNode : public LoadNode {
316 public:
317 LoadFNode( Node *c, Node *mem, Node *adr, const TypePtr* at, const Type *t = Type::FLOAT )
318 : LoadNode(c,mem,adr,at,t) {}
319 virtual int Opcode() const;
320 virtual uint ideal_reg() const { return Op_RegF; }
321 virtual int store_Opcode() const { return Op_StoreF; }
322 virtual BasicType memory_type() const { return T_FLOAT; }
323 };
325 //------------------------------LoadDNode--------------------------------------
326 // Load a double (64 bits) from memory
327 class LoadDNode : public LoadNode {
328 public:
329 LoadDNode( Node *c, Node *mem, Node *adr, const TypePtr* at, const Type *t = Type::DOUBLE )
330 : LoadNode(c,mem,adr,at,t) {}
331 virtual int Opcode() const;
332 virtual uint ideal_reg() const { return Op_RegD; }
333 virtual int store_Opcode() const { return Op_StoreD; }
334 virtual BasicType memory_type() const { return T_DOUBLE; }
335 };
337 //------------------------------LoadD_unalignedNode----------------------------
338 // Load a double from unaligned memory
339 class LoadD_unalignedNode : public LoadDNode {
340 public:
341 LoadD_unalignedNode( Node *c, Node *mem, Node *adr, const TypePtr* at )
342 : LoadDNode(c,mem,adr,at) {}
343 virtual int Opcode() const;
344 };
346 //------------------------------LoadPNode--------------------------------------
347 // Load a pointer from memory (either object or array)
348 class LoadPNode : public LoadNode {
349 public:
350 LoadPNode( Node *c, Node *mem, Node *adr, const TypePtr *at, const TypePtr* t )
351 : LoadNode(c,mem,adr,at,t) {}
352 virtual int Opcode() const;
353 virtual uint ideal_reg() const { return Op_RegP; }
354 virtual int store_Opcode() const { return Op_StoreP; }
355 virtual BasicType memory_type() const { return T_ADDRESS; }
356 // depends_only_on_test is almost always true, and needs to be almost always
357 // true to enable key hoisting & commoning optimizations. However, for the
358 // special case of RawPtr loads from TLS top & end, the control edge carries
359 // the dependence preventing hoisting past a Safepoint instead of the memory
360 // edge. (An unfortunate consequence of having Safepoints not set Raw
361 // Memory; itself an unfortunate consequence of having Nodes which produce
362 // results (new raw memory state) inside of loops preventing all manner of
363 // other optimizations). Basically, it's ugly but so is the alternative.
364 // See comment in macro.cpp, around line 125 expand_allocate_common().
365 virtual bool depends_only_on_test() const { return adr_type() != TypeRawPtr::BOTTOM; }
366 };
369 //------------------------------LoadNNode--------------------------------------
370 // Load a narrow oop from memory (either object or array)
371 class LoadNNode : public LoadNode {
372 public:
373 LoadNNode( Node *c, Node *mem, Node *adr, const TypePtr *at, const Type* t )
374 : LoadNode(c,mem,adr,at,t) {}
375 virtual int Opcode() const;
376 virtual uint ideal_reg() const { return Op_RegN; }
377 virtual int store_Opcode() const { return Op_StoreN; }
378 virtual BasicType memory_type() const { return T_NARROWOOP; }
379 // depends_only_on_test is almost always true, and needs to be almost always
380 // true to enable key hoisting & commoning optimizations. However, for the
381 // special case of RawPtr loads from TLS top & end, the control edge carries
382 // the dependence preventing hoisting past a Safepoint instead of the memory
383 // edge. (An unfortunate consequence of having Safepoints not set Raw
384 // Memory; itself an unfortunate consequence of having Nodes which produce
385 // results (new raw memory state) inside of loops preventing all manner of
386 // other optimizations). Basically, it's ugly but so is the alternative.
387 // See comment in macro.cpp, around line 125 expand_allocate_common().
388 virtual bool depends_only_on_test() const { return adr_type() != TypeRawPtr::BOTTOM; }
389 };
391 //------------------------------LoadKlassNode----------------------------------
392 // Load a Klass from an object
393 class LoadKlassNode : public LoadPNode {
394 public:
395 LoadKlassNode( Node *c, Node *mem, Node *adr, const TypePtr *at, const TypeKlassPtr *tk )
396 : LoadPNode(c,mem,adr,at,tk) {}
397 virtual int Opcode() const;
398 virtual const Type *Value( PhaseTransform *phase ) const;
399 virtual Node *Identity( PhaseTransform *phase );
400 virtual bool depends_only_on_test() const { return true; }
402 // Polymorphic factory method:
403 static Node* make( PhaseGVN& gvn, Node *mem, Node *adr, const TypePtr* at,
404 const TypeKlassPtr *tk = TypeKlassPtr::OBJECT );
405 };
407 //------------------------------LoadNKlassNode---------------------------------
408 // Load a narrow Klass from an object.
409 class LoadNKlassNode : public LoadNNode {
410 public:
411 LoadNKlassNode( Node *c, Node *mem, Node *adr, const TypePtr *at, const TypeNarrowOop *tk )
412 : LoadNNode(c,mem,adr,at,tk) {}
413 virtual int Opcode() const;
414 virtual uint ideal_reg() const { return Op_RegN; }
415 virtual int store_Opcode() const { return Op_StoreN; }
416 virtual BasicType memory_type() const { return T_NARROWOOP; }
418 virtual const Type *Value( PhaseTransform *phase ) const;
419 virtual Node *Identity( PhaseTransform *phase );
420 virtual bool depends_only_on_test() const { return true; }
421 };
424 //------------------------------LoadSNode--------------------------------------
425 // Load a short (16bits signed) from memory
426 class LoadSNode : public LoadNode {
427 public:
428 LoadSNode( Node *c, Node *mem, Node *adr, const TypePtr* at, const TypeInt *ti = TypeInt::SHORT )
429 : LoadNode(c,mem,adr,at,ti) {}
430 virtual int Opcode() const;
431 virtual uint ideal_reg() const { return Op_RegI; }
432 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
433 virtual int store_Opcode() const { return Op_StoreC; }
434 virtual BasicType memory_type() const { return T_SHORT; }
435 };
437 //------------------------------StoreNode--------------------------------------
438 // Store value; requires Store, Address and Value
439 class StoreNode : public MemNode {
440 protected:
441 virtual uint cmp( const Node &n ) const;
442 virtual bool depends_only_on_test() const { return false; }
444 Node *Ideal_masked_input (PhaseGVN *phase, uint mask);
445 Node *Ideal_sign_extended_input(PhaseGVN *phase, int num_bits);
447 public:
448 StoreNode( Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val )
449 : MemNode(c,mem,adr,at,val) {
450 init_class_id(Class_Store);
451 }
452 StoreNode( Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, Node *oop_store )
453 : MemNode(c,mem,adr,at,val,oop_store) {
454 init_class_id(Class_Store);
455 }
457 // Polymorphic factory method:
458 static StoreNode* make( PhaseGVN& gvn, Node *c, Node *mem, Node *adr,
459 const TypePtr* at, Node *val, BasicType bt );
461 virtual uint hash() const; // Check the type
463 // If the store is to Field memory and the pointer is non-null, we can
464 // zero out the control input.
465 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
467 // Compute a new Type for this node. Basically we just do the pre-check,
468 // then call the virtual add() to set the type.
469 virtual const Type *Value( PhaseTransform *phase ) const;
471 // Check for identity function on memory (Load then Store at same address)
472 virtual Node *Identity( PhaseTransform *phase );
474 // Do not match memory edge
475 virtual uint match_edge(uint idx) const;
477 virtual const Type *bottom_type() const; // returns Type::MEMORY
479 // Map a store opcode to its corresponding own opcode, trivially.
480 virtual int store_Opcode() const { return Opcode(); }
482 // have all possible loads of the value stored been optimized away?
483 bool value_never_loaded(PhaseTransform *phase) const;
484 };
486 //------------------------------StoreBNode-------------------------------------
487 // Store byte to memory
488 class StoreBNode : public StoreNode {
489 public:
490 StoreBNode( Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val ) : StoreNode(c,mem,adr,at,val) {}
491 virtual int Opcode() const;
492 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
493 virtual BasicType memory_type() const { return T_BYTE; }
494 };
496 //------------------------------StoreCNode-------------------------------------
497 // Store char/short to memory
498 class StoreCNode : public StoreNode {
499 public:
500 StoreCNode( Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val ) : StoreNode(c,mem,adr,at,val) {}
501 virtual int Opcode() const;
502 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
503 virtual BasicType memory_type() const { return T_CHAR; }
504 };
506 //------------------------------StoreINode-------------------------------------
507 // Store int to memory
508 class StoreINode : public StoreNode {
509 public:
510 StoreINode( Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val ) : StoreNode(c,mem,adr,at,val) {}
511 virtual int Opcode() const;
512 virtual BasicType memory_type() const { return T_INT; }
513 };
515 //------------------------------StoreLNode-------------------------------------
516 // Store long to memory
517 class StoreLNode : public StoreNode {
518 virtual uint hash() const { return StoreNode::hash() + _require_atomic_access; }
519 virtual uint cmp( const Node &n ) const {
520 return _require_atomic_access == ((StoreLNode&)n)._require_atomic_access
521 && StoreNode::cmp(n);
522 }
523 virtual uint size_of() const { return sizeof(*this); }
524 const bool _require_atomic_access; // is piecewise store forbidden?
526 public:
527 StoreLNode( Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val,
528 bool require_atomic_access = false )
529 : StoreNode(c,mem,adr,at,val)
530 , _require_atomic_access(require_atomic_access)
531 {}
532 virtual int Opcode() const;
533 virtual BasicType memory_type() const { return T_LONG; }
534 bool require_atomic_access() { return _require_atomic_access; }
535 static StoreLNode* make_atomic(Compile *C, Node* ctl, Node* mem, Node* adr, const TypePtr* adr_type, Node* val);
536 #ifndef PRODUCT
537 virtual void dump_spec(outputStream *st) const {
538 StoreNode::dump_spec(st);
539 if (_require_atomic_access) st->print(" Atomic!");
540 }
541 #endif
542 };
544 //------------------------------StoreFNode-------------------------------------
545 // Store float to memory
546 class StoreFNode : public StoreNode {
547 public:
548 StoreFNode( Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val ) : StoreNode(c,mem,adr,at,val) {}
549 virtual int Opcode() const;
550 virtual BasicType memory_type() const { return T_FLOAT; }
551 };
553 //------------------------------StoreDNode-------------------------------------
554 // Store double to memory
555 class StoreDNode : public StoreNode {
556 public:
557 StoreDNode( Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val ) : StoreNode(c,mem,adr,at,val) {}
558 virtual int Opcode() const;
559 virtual BasicType memory_type() const { return T_DOUBLE; }
560 };
562 //------------------------------StorePNode-------------------------------------
563 // Store pointer to memory
564 class StorePNode : public StoreNode {
565 public:
566 StorePNode( Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val ) : StoreNode(c,mem,adr,at,val) {}
567 virtual int Opcode() const;
568 virtual BasicType memory_type() const { return T_ADDRESS; }
569 };
571 //------------------------------StoreNNode-------------------------------------
572 // Store narrow oop to memory
573 class StoreNNode : public StoreNode {
574 public:
575 StoreNNode( Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val ) : StoreNode(c,mem,adr,at,val) {}
576 virtual int Opcode() const;
577 virtual BasicType memory_type() const { return T_NARROWOOP; }
578 };
580 //------------------------------StoreCMNode-----------------------------------
581 // Store card-mark byte to memory for CM
582 // The last StoreCM before a SafePoint must be preserved and occur after its "oop" store
583 // Preceeding equivalent StoreCMs may be eliminated.
584 class StoreCMNode : public StoreNode {
585 public:
586 StoreCMNode( Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, Node *oop_store ) : StoreNode(c,mem,adr,at,val,oop_store) {}
587 virtual int Opcode() const;
588 virtual Node *Identity( PhaseTransform *phase );
589 virtual const Type *Value( PhaseTransform *phase ) const;
590 virtual BasicType memory_type() const { return T_VOID; } // unspecific
591 };
593 //------------------------------LoadPLockedNode---------------------------------
594 // Load-locked a pointer from memory (either object or array).
595 // On Sparc & Intel this is implemented as a normal pointer load.
596 // On PowerPC and friends it's a real load-locked.
597 class LoadPLockedNode : public LoadPNode {
598 public:
599 LoadPLockedNode( Node *c, Node *mem, Node *adr )
600 : LoadPNode(c,mem,adr,TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM) {}
601 virtual int Opcode() const;
602 virtual int store_Opcode() const { return Op_StorePConditional; }
603 virtual bool depends_only_on_test() const { return true; }
604 };
606 //------------------------------LoadLLockedNode---------------------------------
607 // Load-locked a pointer from memory (either object or array).
608 // On Sparc & Intel this is implemented as a normal long load.
609 class LoadLLockedNode : public LoadLNode {
610 public:
611 LoadLLockedNode( Node *c, Node *mem, Node *adr )
612 : LoadLNode(c,mem,adr,TypeRawPtr::BOTTOM, TypeLong::LONG) {}
613 virtual int Opcode() const;
614 virtual int store_Opcode() const { return Op_StoreLConditional; }
615 };
617 //------------------------------SCMemProjNode---------------------------------------
618 // This class defines a projection of the memory state of a store conditional node.
619 // These nodes return a value, but also update memory.
620 class SCMemProjNode : public ProjNode {
621 public:
622 enum {SCMEMPROJCON = (uint)-2};
623 SCMemProjNode( Node *src) : ProjNode( src, SCMEMPROJCON) { }
624 virtual int Opcode() const;
625 virtual bool is_CFG() const { return false; }
626 virtual const Type *bottom_type() const {return Type::MEMORY;}
627 virtual const TypePtr *adr_type() const { return in(0)->in(MemNode::Memory)->adr_type();}
628 virtual uint ideal_reg() const { return 0;} // memory projections don't have a register
629 virtual const Type *Value( PhaseTransform *phase ) const;
630 #ifndef PRODUCT
631 virtual void dump_spec(outputStream *st) const {};
632 #endif
633 };
635 //------------------------------LoadStoreNode---------------------------
636 // Note: is_Mem() method returns 'true' for this class.
637 class LoadStoreNode : public Node {
638 public:
639 enum {
640 ExpectedIn = MemNode::ValueIn+1 // One more input than MemNode
641 };
642 LoadStoreNode( Node *c, Node *mem, Node *adr, Node *val, Node *ex);
643 virtual bool depends_only_on_test() const { return false; }
644 virtual const Type *bottom_type() const { return TypeInt::BOOL; }
645 virtual uint ideal_reg() const { return Op_RegI; }
646 virtual uint match_edge(uint idx) const { return idx == MemNode::Address || idx == MemNode::ValueIn; }
647 };
649 //------------------------------StorePConditionalNode---------------------------
650 // Conditionally store pointer to memory, if no change since prior
651 // load-locked. Sets flags for success or failure of the store.
652 class StorePConditionalNode : public LoadStoreNode {
653 public:
654 StorePConditionalNode( Node *c, Node *mem, Node *adr, Node *val, Node *ll ) : LoadStoreNode(c, mem, adr, val, ll) { }
655 virtual int Opcode() const;
656 // Produces flags
657 virtual uint ideal_reg() const { return Op_RegFlags; }
658 };
660 //------------------------------StoreIConditionalNode---------------------------
661 // Conditionally store int to memory, if no change since prior
662 // load-locked. Sets flags for success or failure of the store.
663 class StoreIConditionalNode : public LoadStoreNode {
664 public:
665 StoreIConditionalNode( Node *c, Node *mem, Node *adr, Node *val, Node *ii ) : LoadStoreNode(c, mem, adr, val, ii) { }
666 virtual int Opcode() const;
667 // Produces flags
668 virtual uint ideal_reg() const { return Op_RegFlags; }
669 };
671 //------------------------------StoreLConditionalNode---------------------------
672 // Conditionally store long to memory, if no change since prior
673 // load-locked. Sets flags for success or failure of the store.
674 class StoreLConditionalNode : public LoadStoreNode {
675 public:
676 StoreLConditionalNode( Node *c, Node *mem, Node *adr, Node *val, Node *ll ) : LoadStoreNode(c, mem, adr, val, ll) { }
677 virtual int Opcode() const;
678 // Produces flags
679 virtual uint ideal_reg() const { return Op_RegFlags; }
680 };
683 //------------------------------CompareAndSwapLNode---------------------------
684 class CompareAndSwapLNode : public LoadStoreNode {
685 public:
686 CompareAndSwapLNode( Node *c, Node *mem, Node *adr, Node *val, Node *ex) : LoadStoreNode(c, mem, adr, val, ex) { }
687 virtual int Opcode() const;
688 };
691 //------------------------------CompareAndSwapINode---------------------------
692 class CompareAndSwapINode : public LoadStoreNode {
693 public:
694 CompareAndSwapINode( Node *c, Node *mem, Node *adr, Node *val, Node *ex) : LoadStoreNode(c, mem, adr, val, ex) { }
695 virtual int Opcode() const;
696 };
699 //------------------------------CompareAndSwapPNode---------------------------
700 class CompareAndSwapPNode : public LoadStoreNode {
701 public:
702 CompareAndSwapPNode( Node *c, Node *mem, Node *adr, Node *val, Node *ex) : LoadStoreNode(c, mem, adr, val, ex) { }
703 virtual int Opcode() const;
704 };
706 //------------------------------CompareAndSwapNNode---------------------------
707 class CompareAndSwapNNode : public LoadStoreNode {
708 public:
709 CompareAndSwapNNode( Node *c, Node *mem, Node *adr, Node *val, Node *ex) : LoadStoreNode(c, mem, adr, val, ex) { }
710 virtual int Opcode() const;
711 };
713 //------------------------------ClearArray-------------------------------------
714 class ClearArrayNode: public Node {
715 public:
716 ClearArrayNode( Node *ctrl, Node *arymem, Node *word_cnt, Node *base ) : Node(ctrl,arymem,word_cnt,base) {}
717 virtual int Opcode() const;
718 virtual const Type *bottom_type() const { return Type::MEMORY; }
719 // ClearArray modifies array elements, and so affects only the
720 // array memory addressed by the bottom_type of its base address.
721 virtual const class TypePtr *adr_type() const;
722 virtual Node *Identity( PhaseTransform *phase );
723 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
724 virtual uint match_edge(uint idx) const;
726 // Clear the given area of an object or array.
727 // The start offset must always be aligned mod BytesPerInt.
728 // The end offset must always be aligned mod BytesPerLong.
729 // Return the new memory.
730 static Node* clear_memory(Node* control, Node* mem, Node* dest,
731 intptr_t start_offset,
732 intptr_t end_offset,
733 PhaseGVN* phase);
734 static Node* clear_memory(Node* control, Node* mem, Node* dest,
735 intptr_t start_offset,
736 Node* end_offset,
737 PhaseGVN* phase);
738 static Node* clear_memory(Node* control, Node* mem, Node* dest,
739 Node* start_offset,
740 Node* end_offset,
741 PhaseGVN* phase);
742 };
744 //------------------------------StrComp-------------------------------------
745 class StrCompNode: public Node {
746 public:
747 StrCompNode(Node *control,
748 Node* char_array_mem,
749 Node* value_mem,
750 Node* count_mem,
751 Node* offset_mem,
752 Node* s1, Node* s2): Node(control,
753 char_array_mem,
754 value_mem,
755 count_mem,
756 offset_mem,
757 s1, s2) {};
758 virtual int Opcode() const;
759 virtual bool depends_only_on_test() const { return false; }
760 virtual const Type* bottom_type() const { return TypeInt::INT; }
761 // a StrCompNode (conservatively) aliases with everything:
762 virtual const TypePtr* adr_type() const { return TypePtr::BOTTOM; }
763 virtual uint match_edge(uint idx) const;
764 virtual uint ideal_reg() const { return Op_RegI; }
765 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
766 };
768 //------------------------------AryEq---------------------------------------
769 class AryEqNode: public Node {
770 public:
771 AryEqNode(Node *control, Node* s1, Node* s2): Node(control, s1, s2) {};
772 virtual int Opcode() const;
773 virtual bool depends_only_on_test() const { return false; }
774 virtual const Type* bottom_type() const { return TypeInt::BOOL; }
775 virtual const TypePtr* adr_type() const { return TypeAryPtr::CHARS; }
776 virtual uint ideal_reg() const { return Op_RegI; }
777 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
778 };
780 //------------------------------MemBar-----------------------------------------
781 // There are different flavors of Memory Barriers to match the Java Memory
782 // Model. Monitor-enter and volatile-load act as Aquires: no following ref
783 // can be moved to before them. We insert a MemBar-Acquire after a FastLock or
784 // volatile-load. Monitor-exit and volatile-store act as Release: no
785 // preceding ref can be moved to after them. We insert a MemBar-Release
786 // before a FastUnlock or volatile-store. All volatiles need to be
787 // serialized, so we follow all volatile-stores with a MemBar-Volatile to
788 // separate it from any following volatile-load.
789 class MemBarNode: public MultiNode {
790 virtual uint hash() const ; // { return NO_HASH; }
791 virtual uint cmp( const Node &n ) const ; // Always fail, except on self
793 virtual uint size_of() const { return sizeof(*this); }
794 // Memory type this node is serializing. Usually either rawptr or bottom.
795 const TypePtr* _adr_type;
797 public:
798 enum {
799 Precedent = TypeFunc::Parms // optional edge to force precedence
800 };
801 MemBarNode(Compile* C, int alias_idx, Node* precedent);
802 virtual int Opcode() const = 0;
803 virtual const class TypePtr *adr_type() const { return _adr_type; }
804 virtual const Type *Value( PhaseTransform *phase ) const;
805 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
806 virtual uint match_edge(uint idx) const { return 0; }
807 virtual const Type *bottom_type() const { return TypeTuple::MEMBAR; }
808 virtual Node *match( const ProjNode *proj, const Matcher *m );
809 // Factory method. Builds a wide or narrow membar.
810 // Optional 'precedent' becomes an extra edge if not null.
811 static MemBarNode* make(Compile* C, int opcode,
812 int alias_idx = Compile::AliasIdxBot,
813 Node* precedent = NULL);
814 };
816 // "Acquire" - no following ref can move before (but earlier refs can
817 // follow, like an early Load stalled in cache). Requires multi-cpu
818 // visibility. Inserted after a volatile load or FastLock.
819 class MemBarAcquireNode: public MemBarNode {
820 public:
821 MemBarAcquireNode(Compile* C, int alias_idx, Node* precedent)
822 : MemBarNode(C, alias_idx, precedent) {}
823 virtual int Opcode() const;
824 };
826 // "Release" - no earlier ref can move after (but later refs can move
827 // up, like a speculative pipelined cache-hitting Load). Requires
828 // multi-cpu visibility. Inserted before a volatile store or FastUnLock.
829 class MemBarReleaseNode: public MemBarNode {
830 public:
831 MemBarReleaseNode(Compile* C, int alias_idx, Node* precedent)
832 : MemBarNode(C, alias_idx, precedent) {}
833 virtual int Opcode() const;
834 };
836 // Ordering between a volatile store and a following volatile load.
837 // Requires multi-CPU visibility?
838 class MemBarVolatileNode: public MemBarNode {
839 public:
840 MemBarVolatileNode(Compile* C, int alias_idx, Node* precedent)
841 : MemBarNode(C, alias_idx, precedent) {}
842 virtual int Opcode() const;
843 };
845 // Ordering within the same CPU. Used to order unsafe memory references
846 // inside the compiler when we lack alias info. Not needed "outside" the
847 // compiler because the CPU does all the ordering for us.
848 class MemBarCPUOrderNode: public MemBarNode {
849 public:
850 MemBarCPUOrderNode(Compile* C, int alias_idx, Node* precedent)
851 : MemBarNode(C, alias_idx, precedent) {}
852 virtual int Opcode() const;
853 virtual uint ideal_reg() const { return 0; } // not matched in the AD file
854 };
856 // Isolation of object setup after an AllocateNode and before next safepoint.
857 // (See comment in memnode.cpp near InitializeNode::InitializeNode for semantics.)
858 class InitializeNode: public MemBarNode {
859 friend class AllocateNode;
861 bool _is_complete;
863 public:
864 enum {
865 Control = TypeFunc::Control,
866 Memory = TypeFunc::Memory, // MergeMem for states affected by this op
867 RawAddress = TypeFunc::Parms+0, // the newly-allocated raw address
868 RawStores = TypeFunc::Parms+1 // zero or more stores (or TOP)
869 };
871 InitializeNode(Compile* C, int adr_type, Node* rawoop);
872 virtual int Opcode() const;
873 virtual uint size_of() const { return sizeof(*this); }
874 virtual uint ideal_reg() const { return 0; } // not matched in the AD file
875 virtual const RegMask &in_RegMask(uint) const; // mask for RawAddress
877 // Manage incoming memory edges via a MergeMem on in(Memory):
878 Node* memory(uint alias_idx);
880 // The raw memory edge coming directly from the Allocation.
881 // The contents of this memory are *always* all-zero-bits.
882 Node* zero_memory() { return memory(Compile::AliasIdxRaw); }
884 // Return the corresponding allocation for this initialization (or null if none).
885 // (Note: Both InitializeNode::allocation and AllocateNode::initialization
886 // are defined in graphKit.cpp, which sets up the bidirectional relation.)
887 AllocateNode* allocation();
889 // Anything other than zeroing in this init?
890 bool is_non_zero();
892 // An InitializeNode must completed before macro expansion is done.
893 // Completion requires that the AllocateNode must be followed by
894 // initialization of the new memory to zero, then to any initializers.
895 bool is_complete() { return _is_complete; }
897 // Mark complete. (Must not yet be complete.)
898 void set_complete(PhaseGVN* phase);
900 #ifdef ASSERT
901 // ensure all non-degenerate stores are ordered and non-overlapping
902 bool stores_are_sane(PhaseTransform* phase);
903 #endif //ASSERT
905 // See if this store can be captured; return offset where it initializes.
906 // Return 0 if the store cannot be moved (any sort of problem).
907 intptr_t can_capture_store(StoreNode* st, PhaseTransform* phase);
909 // Capture another store; reformat it to write my internal raw memory.
910 // Return the captured copy, else NULL if there is some sort of problem.
911 Node* capture_store(StoreNode* st, intptr_t start, PhaseTransform* phase);
913 // Find captured store which corresponds to the range [start..start+size).
914 // Return my own memory projection (meaning the initial zero bits)
915 // if there is no such store. Return NULL if there is a problem.
916 Node* find_captured_store(intptr_t start, int size_in_bytes, PhaseTransform* phase);
918 // Called when the associated AllocateNode is expanded into CFG.
919 Node* complete_stores(Node* rawctl, Node* rawmem, Node* rawptr,
920 intptr_t header_size, Node* size_in_bytes,
921 PhaseGVN* phase);
923 private:
924 void remove_extra_zeroes();
926 // Find out where a captured store should be placed (or already is placed).
927 int captured_store_insertion_point(intptr_t start, int size_in_bytes,
928 PhaseTransform* phase);
930 static intptr_t get_store_offset(Node* st, PhaseTransform* phase);
932 Node* make_raw_address(intptr_t offset, PhaseTransform* phase);
934 bool detect_init_independence(Node* n, bool st_is_pinned, int& count);
936 void coalesce_subword_stores(intptr_t header_size, Node* size_in_bytes,
937 PhaseGVN* phase);
939 intptr_t find_next_fullword_store(uint i, PhaseGVN* phase);
940 };
942 //------------------------------MergeMem---------------------------------------
943 // (See comment in memnode.cpp near MergeMemNode::MergeMemNode for semantics.)
944 class MergeMemNode: public Node {
945 virtual uint hash() const ; // { return NO_HASH; }
946 virtual uint cmp( const Node &n ) const ; // Always fail, except on self
947 friend class MergeMemStream;
948 MergeMemNode(Node* def); // clients use MergeMemNode::make
950 public:
951 // If the input is a whole memory state, clone it with all its slices intact.
952 // Otherwise, make a new memory state with just that base memory input.
953 // In either case, the result is a newly created MergeMem.
954 static MergeMemNode* make(Compile* C, Node* base_memory);
956 virtual int Opcode() const;
957 virtual Node *Identity( PhaseTransform *phase );
958 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
959 virtual uint ideal_reg() const { return NotAMachineReg; }
960 virtual uint match_edge(uint idx) const { return 0; }
961 virtual const RegMask &out_RegMask() const;
962 virtual const Type *bottom_type() const { return Type::MEMORY; }
963 virtual const TypePtr *adr_type() const { return TypePtr::BOTTOM; }
964 // sparse accessors
965 // Fetch the previously stored "set_memory_at", or else the base memory.
966 // (Caller should clone it if it is a phi-nest.)
967 Node* memory_at(uint alias_idx) const;
968 // set the memory, regardless of its previous value
969 void set_memory_at(uint alias_idx, Node* n);
970 // the "base" is the memory that provides the non-finite support
971 Node* base_memory() const { return in(Compile::AliasIdxBot); }
972 // warning: setting the base can implicitly set any of the other slices too
973 void set_base_memory(Node* def);
974 // sentinel value which denotes a copy of the base memory:
975 Node* empty_memory() const { return in(Compile::AliasIdxTop); }
976 static Node* make_empty_memory(); // where the sentinel comes from
977 bool is_empty_memory(Node* n) const { assert((n == empty_memory()) == n->is_top(), "sanity"); return n->is_top(); }
978 // hook for the iterator, to perform any necessary setup
979 void iteration_setup(const MergeMemNode* other = NULL);
980 // push sentinels until I am at least as long as the other (semantic no-op)
981 void grow_to_match(const MergeMemNode* other);
982 bool verify_sparse() const PRODUCT_RETURN0;
983 #ifndef PRODUCT
984 virtual void dump_spec(outputStream *st) const;
985 #endif
986 };
988 class MergeMemStream : public StackObj {
989 private:
990 MergeMemNode* _mm;
991 const MergeMemNode* _mm2; // optional second guy, contributes non-empty iterations
992 Node* _mm_base; // loop-invariant base memory of _mm
993 int _idx;
994 int _cnt;
995 Node* _mem;
996 Node* _mem2;
997 int _cnt2;
999 void init(MergeMemNode* mm, const MergeMemNode* mm2 = NULL) {
1000 // subsume_node will break sparseness at times, whenever a memory slice
1001 // folds down to a copy of the base ("fat") memory. In such a case,
1002 // the raw edge will update to base, although it should be top.
1003 // This iterator will recognize either top or base_memory as an
1004 // "empty" slice. See is_empty, is_empty2, and next below.
1005 //
1006 // The sparseness property is repaired in MergeMemNode::Ideal.
1007 // As long as access to a MergeMem goes through this iterator
1008 // or the memory_at accessor, flaws in the sparseness will
1009 // never be observed.
1010 //
1011 // Also, iteration_setup repairs sparseness.
1012 assert(mm->verify_sparse(), "please, no dups of base");
1013 assert(mm2==NULL || mm2->verify_sparse(), "please, no dups of base");
1015 _mm = mm;
1016 _mm_base = mm->base_memory();
1017 _mm2 = mm2;
1018 _cnt = mm->req();
1019 _idx = Compile::AliasIdxBot-1; // start at the base memory
1020 _mem = NULL;
1021 _mem2 = NULL;
1022 }
1024 #ifdef ASSERT
1025 Node* check_memory() const {
1026 if (at_base_memory())
1027 return _mm->base_memory();
1028 else if ((uint)_idx < _mm->req() && !_mm->in(_idx)->is_top())
1029 return _mm->memory_at(_idx);
1030 else
1031 return _mm_base;
1032 }
1033 Node* check_memory2() const {
1034 return at_base_memory()? _mm2->base_memory(): _mm2->memory_at(_idx);
1035 }
1036 #endif
1038 static bool match_memory(Node* mem, const MergeMemNode* mm, int idx) PRODUCT_RETURN0;
1039 void assert_synch() const {
1040 assert(!_mem || _idx >= _cnt || match_memory(_mem, _mm, _idx),
1041 "no side-effects except through the stream");
1042 }
1044 public:
1046 // expected usages:
1047 // for (MergeMemStream mms(mem->is_MergeMem()); next_non_empty(); ) { ... }
1048 // for (MergeMemStream mms(mem1, mem2); next_non_empty2(); ) { ... }
1050 // iterate over one merge
1051 MergeMemStream(MergeMemNode* mm) {
1052 mm->iteration_setup();
1053 init(mm);
1054 debug_only(_cnt2 = 999);
1055 }
1056 // iterate in parallel over two merges
1057 // only iterates through non-empty elements of mm2
1058 MergeMemStream(MergeMemNode* mm, const MergeMemNode* mm2) {
1059 assert(mm2, "second argument must be a MergeMem also");
1060 ((MergeMemNode*)mm2)->iteration_setup(); // update hidden state
1061 mm->iteration_setup(mm2);
1062 init(mm, mm2);
1063 _cnt2 = mm2->req();
1064 }
1065 #ifdef ASSERT
1066 ~MergeMemStream() {
1067 assert_synch();
1068 }
1069 #endif
1071 MergeMemNode* all_memory() const {
1072 return _mm;
1073 }
1074 Node* base_memory() const {
1075 assert(_mm_base == _mm->base_memory(), "no update to base memory, please");
1076 return _mm_base;
1077 }
1078 const MergeMemNode* all_memory2() const {
1079 assert(_mm2 != NULL, "");
1080 return _mm2;
1081 }
1082 bool at_base_memory() const {
1083 return _idx == Compile::AliasIdxBot;
1084 }
1085 int alias_idx() const {
1086 assert(_mem, "must call next 1st");
1087 return _idx;
1088 }
1090 const TypePtr* adr_type() const {
1091 return Compile::current()->get_adr_type(alias_idx());
1092 }
1094 const TypePtr* adr_type(Compile* C) const {
1095 return C->get_adr_type(alias_idx());
1096 }
1097 bool is_empty() const {
1098 assert(_mem, "must call next 1st");
1099 assert(_mem->is_top() == (_mem==_mm->empty_memory()), "correct sentinel");
1100 return _mem->is_top();
1101 }
1102 bool is_empty2() const {
1103 assert(_mem2, "must call next 1st");
1104 assert(_mem2->is_top() == (_mem2==_mm2->empty_memory()), "correct sentinel");
1105 return _mem2->is_top();
1106 }
1107 Node* memory() const {
1108 assert(!is_empty(), "must not be empty");
1109 assert_synch();
1110 return _mem;
1111 }
1112 // get the current memory, regardless of empty or non-empty status
1113 Node* force_memory() const {
1114 assert(!is_empty() || !at_base_memory(), "");
1115 // Use _mm_base to defend against updates to _mem->base_memory().
1116 Node *mem = _mem->is_top() ? _mm_base : _mem;
1117 assert(mem == check_memory(), "");
1118 return mem;
1119 }
1120 Node* memory2() const {
1121 assert(_mem2 == check_memory2(), "");
1122 return _mem2;
1123 }
1124 void set_memory(Node* mem) {
1125 if (at_base_memory()) {
1126 // Note that this does not change the invariant _mm_base.
1127 _mm->set_base_memory(mem);
1128 } else {
1129 _mm->set_memory_at(_idx, mem);
1130 }
1131 _mem = mem;
1132 assert_synch();
1133 }
1135 // Recover from a side effect to the MergeMemNode.
1136 void set_memory() {
1137 _mem = _mm->in(_idx);
1138 }
1140 bool next() { return next(false); }
1141 bool next2() { return next(true); }
1143 bool next_non_empty() { return next_non_empty(false); }
1144 bool next_non_empty2() { return next_non_empty(true); }
1145 // next_non_empty2 can yield states where is_empty() is true
1147 private:
1148 // find the next item, which might be empty
1149 bool next(bool have_mm2) {
1150 assert((_mm2 != NULL) == have_mm2, "use other next");
1151 assert_synch();
1152 if (++_idx < _cnt) {
1153 // Note: This iterator allows _mm to be non-sparse.
1154 // It behaves the same whether _mem is top or base_memory.
1155 _mem = _mm->in(_idx);
1156 if (have_mm2)
1157 _mem2 = _mm2->in((_idx < _cnt2) ? _idx : Compile::AliasIdxTop);
1158 return true;
1159 }
1160 return false;
1161 }
1163 // find the next non-empty item
1164 bool next_non_empty(bool have_mm2) {
1165 while (next(have_mm2)) {
1166 if (!is_empty()) {
1167 // make sure _mem2 is filled in sensibly
1168 if (have_mm2 && _mem2->is_top()) _mem2 = _mm2->base_memory();
1169 return true;
1170 } else if (have_mm2 && !is_empty2()) {
1171 return true; // is_empty() == true
1172 }
1173 }
1174 return false;
1175 }
1176 };
1178 //------------------------------Prefetch---------------------------------------
1180 // Non-faulting prefetch load. Prefetch for many reads.
1181 class PrefetchReadNode : public Node {
1182 public:
1183 PrefetchReadNode(Node *abio, Node *adr) : Node(0,abio,adr) {}
1184 virtual int Opcode() const;
1185 virtual uint ideal_reg() const { return NotAMachineReg; }
1186 virtual uint match_edge(uint idx) const { return idx==2; }
1187 virtual const Type *bottom_type() const { return Type::ABIO; }
1188 };
1190 // Non-faulting prefetch load. Prefetch for many reads & many writes.
1191 class PrefetchWriteNode : public Node {
1192 public:
1193 PrefetchWriteNode(Node *abio, Node *adr) : Node(0,abio,adr) {}
1194 virtual int Opcode() const;
1195 virtual uint ideal_reg() const { return NotAMachineReg; }
1196 virtual uint match_edge(uint idx) const { return idx==2; }
1197 virtual const Type *bottom_type() const { return Type::ABIO; }
1198 };