Wed, 02 Jul 2008 12:55:16 -0700
6719955: Update copyright year
Summary: Update copyright year for files that have been modified in 2008
Reviewed-by: ohair, tbell
1 /*
2 * Copyright 1997-2008 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 //------------------------------LoadCNode--------------------------------------
211 // Load a char (16bits unsigned) from memory
212 class LoadCNode : public LoadNode {
213 public:
214 LoadCNode( Node *c, Node *mem, Node *adr, const TypePtr* at, const TypeInt *ti = TypeInt::CHAR )
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_StoreC; }
220 virtual BasicType memory_type() const { return T_CHAR; }
221 };
223 //------------------------------LoadINode--------------------------------------
224 // Load an integer from memory
225 class LoadINode : public LoadNode {
226 public:
227 LoadINode( Node *c, Node *mem, Node *adr, const TypePtr* at, const TypeInt *ti = TypeInt::INT )
228 : LoadNode(c,mem,adr,at,ti) {}
229 virtual int Opcode() const;
230 virtual uint ideal_reg() const { return Op_RegI; }
231 virtual int store_Opcode() const { return Op_StoreI; }
232 virtual BasicType memory_type() const { return T_INT; }
233 };
235 //------------------------------LoadRangeNode----------------------------------
236 // Load an array length from the array
237 class LoadRangeNode : public LoadINode {
238 public:
239 LoadRangeNode( Node *c, Node *mem, Node *adr, const TypeInt *ti = TypeInt::POS )
240 : LoadINode(c,mem,adr,TypeAryPtr::RANGE,ti) {}
241 virtual int Opcode() const;
242 virtual const Type *Value( PhaseTransform *phase ) const;
243 virtual Node *Identity( PhaseTransform *phase );
244 };
246 //------------------------------LoadLNode--------------------------------------
247 // Load a long from memory
248 class LoadLNode : public LoadNode {
249 virtual uint hash() const { return LoadNode::hash() + _require_atomic_access; }
250 virtual uint cmp( const Node &n ) const {
251 return _require_atomic_access == ((LoadLNode&)n)._require_atomic_access
252 && LoadNode::cmp(n);
253 }
254 virtual uint size_of() const { return sizeof(*this); }
255 const bool _require_atomic_access; // is piecewise load forbidden?
257 public:
258 LoadLNode( Node *c, Node *mem, Node *adr, const TypePtr* at,
259 const TypeLong *tl = TypeLong::LONG,
260 bool require_atomic_access = false )
261 : LoadNode(c,mem,adr,at,tl)
262 , _require_atomic_access(require_atomic_access)
263 {}
264 virtual int Opcode() const;
265 virtual uint ideal_reg() const { return Op_RegL; }
266 virtual int store_Opcode() const { return Op_StoreL; }
267 virtual BasicType memory_type() const { return T_LONG; }
268 bool require_atomic_access() { return _require_atomic_access; }
269 static LoadLNode* make_atomic(Compile *C, Node* ctl, Node* mem, Node* adr, const TypePtr* adr_type, const Type* rt);
270 #ifndef PRODUCT
271 virtual void dump_spec(outputStream *st) const {
272 LoadNode::dump_spec(st);
273 if (_require_atomic_access) st->print(" Atomic!");
274 }
275 #endif
276 };
278 //------------------------------LoadL_unalignedNode----------------------------
279 // Load a long from unaligned memory
280 class LoadL_unalignedNode : public LoadLNode {
281 public:
282 LoadL_unalignedNode( Node *c, Node *mem, Node *adr, const TypePtr* at )
283 : LoadLNode(c,mem,adr,at) {}
284 virtual int Opcode() const;
285 };
287 //------------------------------LoadFNode--------------------------------------
288 // Load a float (64 bits) from memory
289 class LoadFNode : public LoadNode {
290 public:
291 LoadFNode( Node *c, Node *mem, Node *adr, const TypePtr* at, const Type *t = Type::FLOAT )
292 : LoadNode(c,mem,adr,at,t) {}
293 virtual int Opcode() const;
294 virtual uint ideal_reg() const { return Op_RegF; }
295 virtual int store_Opcode() const { return Op_StoreF; }
296 virtual BasicType memory_type() const { return T_FLOAT; }
297 };
299 //------------------------------LoadDNode--------------------------------------
300 // Load a double (64 bits) from memory
301 class LoadDNode : public LoadNode {
302 public:
303 LoadDNode( Node *c, Node *mem, Node *adr, const TypePtr* at, const Type *t = Type::DOUBLE )
304 : LoadNode(c,mem,adr,at,t) {}
305 virtual int Opcode() const;
306 virtual uint ideal_reg() const { return Op_RegD; }
307 virtual int store_Opcode() const { return Op_StoreD; }
308 virtual BasicType memory_type() const { return T_DOUBLE; }
309 };
311 //------------------------------LoadD_unalignedNode----------------------------
312 // Load a double from unaligned memory
313 class LoadD_unalignedNode : public LoadDNode {
314 public:
315 LoadD_unalignedNode( Node *c, Node *mem, Node *adr, const TypePtr* at )
316 : LoadDNode(c,mem,adr,at) {}
317 virtual int Opcode() const;
318 };
320 //------------------------------LoadPNode--------------------------------------
321 // Load a pointer from memory (either object or array)
322 class LoadPNode : public LoadNode {
323 public:
324 LoadPNode( Node *c, Node *mem, Node *adr, const TypePtr *at, const TypePtr* t )
325 : LoadNode(c,mem,adr,at,t) {}
326 virtual int Opcode() const;
327 virtual uint ideal_reg() const { return Op_RegP; }
328 virtual int store_Opcode() const { return Op_StoreP; }
329 virtual BasicType memory_type() const { return T_ADDRESS; }
330 // depends_only_on_test is almost always true, and needs to be almost always
331 // true to enable key hoisting & commoning optimizations. However, for the
332 // special case of RawPtr loads from TLS top & end, the control edge carries
333 // the dependence preventing hoisting past a Safepoint instead of the memory
334 // edge. (An unfortunate consequence of having Safepoints not set Raw
335 // Memory; itself an unfortunate consequence of having Nodes which produce
336 // results (new raw memory state) inside of loops preventing all manner of
337 // other optimizations). Basically, it's ugly but so is the alternative.
338 // See comment in macro.cpp, around line 125 expand_allocate_common().
339 virtual bool depends_only_on_test() const { return adr_type() != TypeRawPtr::BOTTOM; }
340 };
343 //------------------------------LoadNNode--------------------------------------
344 // Load a narrow oop from memory (either object or array)
345 class LoadNNode : public LoadNode {
346 public:
347 LoadNNode( Node *c, Node *mem, Node *adr, const TypePtr *at, const Type* t )
348 : LoadNode(c,mem,adr,at,t) {}
349 virtual int Opcode() const;
350 virtual uint ideal_reg() const { return Op_RegN; }
351 virtual int store_Opcode() const { return Op_StoreN; }
352 virtual BasicType memory_type() const { return T_NARROWOOP; }
353 // depends_only_on_test is almost always true, and needs to be almost always
354 // true to enable key hoisting & commoning optimizations. However, for the
355 // special case of RawPtr loads from TLS top & end, the control edge carries
356 // the dependence preventing hoisting past a Safepoint instead of the memory
357 // edge. (An unfortunate consequence of having Safepoints not set Raw
358 // Memory; itself an unfortunate consequence of having Nodes which produce
359 // results (new raw memory state) inside of loops preventing all manner of
360 // other optimizations). Basically, it's ugly but so is the alternative.
361 // See comment in macro.cpp, around line 125 expand_allocate_common().
362 virtual bool depends_only_on_test() const { return adr_type() != TypeRawPtr::BOTTOM; }
363 };
365 //------------------------------LoadKlassNode----------------------------------
366 // Load a Klass from an object
367 class LoadKlassNode : public LoadPNode {
368 public:
369 LoadKlassNode( Node *c, Node *mem, Node *adr, const TypePtr *at, const TypeKlassPtr *tk )
370 : LoadPNode(c,mem,adr,at,tk) {}
371 virtual int Opcode() const;
372 virtual const Type *Value( PhaseTransform *phase ) const;
373 virtual Node *Identity( PhaseTransform *phase );
374 virtual bool depends_only_on_test() const { return true; }
376 // Polymorphic factory method:
377 static Node* make( PhaseGVN& gvn, Node *mem, Node *adr, const TypePtr* at,
378 const TypeKlassPtr *tk = TypeKlassPtr::OBJECT );
379 };
381 //------------------------------LoadNKlassNode---------------------------------
382 // Load a narrow Klass from an object.
383 class LoadNKlassNode : public LoadNNode {
384 public:
385 LoadNKlassNode( Node *c, Node *mem, Node *adr, const TypePtr *at, const TypeNarrowOop *tk )
386 : LoadNNode(c,mem,adr,at,tk) {}
387 virtual int Opcode() const;
388 virtual uint ideal_reg() const { return Op_RegN; }
389 virtual int store_Opcode() const { return Op_StoreN; }
390 virtual BasicType memory_type() const { return T_NARROWOOP; }
392 virtual const Type *Value( PhaseTransform *phase ) const;
393 virtual Node *Identity( PhaseTransform *phase );
394 virtual bool depends_only_on_test() const { return true; }
395 };
398 //------------------------------LoadSNode--------------------------------------
399 // Load a short (16bits signed) from memory
400 class LoadSNode : public LoadNode {
401 public:
402 LoadSNode( Node *c, Node *mem, Node *adr, const TypePtr* at, const TypeInt *ti = TypeInt::SHORT )
403 : LoadNode(c,mem,adr,at,ti) {}
404 virtual int Opcode() const;
405 virtual uint ideal_reg() const { return Op_RegI; }
406 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
407 virtual int store_Opcode() const { return Op_StoreC; }
408 virtual BasicType memory_type() const { return T_SHORT; }
409 };
411 //------------------------------StoreNode--------------------------------------
412 // Store value; requires Store, Address and Value
413 class StoreNode : public MemNode {
414 protected:
415 virtual uint cmp( const Node &n ) const;
416 virtual bool depends_only_on_test() const { return false; }
418 Node *Ideal_masked_input (PhaseGVN *phase, uint mask);
419 Node *Ideal_sign_extended_input(PhaseGVN *phase, int num_bits);
421 public:
422 StoreNode( Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val )
423 : MemNode(c,mem,adr,at,val) {
424 init_class_id(Class_Store);
425 }
426 StoreNode( Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, Node *oop_store )
427 : MemNode(c,mem,adr,at,val,oop_store) {
428 init_class_id(Class_Store);
429 }
431 // Polymorphic factory method:
432 static StoreNode* make( PhaseGVN& gvn, Node *c, Node *mem, Node *adr,
433 const TypePtr* at, Node *val, BasicType bt );
435 virtual uint hash() const; // Check the type
437 // If the store is to Field memory and the pointer is non-null, we can
438 // zero out the control input.
439 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
441 // Compute a new Type for this node. Basically we just do the pre-check,
442 // then call the virtual add() to set the type.
443 virtual const Type *Value( PhaseTransform *phase ) const;
445 // Check for identity function on memory (Load then Store at same address)
446 virtual Node *Identity( PhaseTransform *phase );
448 // Do not match memory edge
449 virtual uint match_edge(uint idx) const;
451 virtual const Type *bottom_type() const; // returns Type::MEMORY
453 // Map a store opcode to its corresponding own opcode, trivially.
454 virtual int store_Opcode() const { return Opcode(); }
456 // have all possible loads of the value stored been optimized away?
457 bool value_never_loaded(PhaseTransform *phase) const;
458 };
460 //------------------------------StoreBNode-------------------------------------
461 // Store byte to memory
462 class StoreBNode : public StoreNode {
463 public:
464 StoreBNode( Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val ) : StoreNode(c,mem,adr,at,val) {}
465 virtual int Opcode() const;
466 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
467 virtual BasicType memory_type() const { return T_BYTE; }
468 };
470 //------------------------------StoreCNode-------------------------------------
471 // Store char/short to memory
472 class StoreCNode : public StoreNode {
473 public:
474 StoreCNode( Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val ) : StoreNode(c,mem,adr,at,val) {}
475 virtual int Opcode() const;
476 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
477 virtual BasicType memory_type() const { return T_CHAR; }
478 };
480 //------------------------------StoreINode-------------------------------------
481 // Store int to memory
482 class StoreINode : public StoreNode {
483 public:
484 StoreINode( Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val ) : StoreNode(c,mem,adr,at,val) {}
485 virtual int Opcode() const;
486 virtual BasicType memory_type() const { return T_INT; }
487 };
489 //------------------------------StoreLNode-------------------------------------
490 // Store long to memory
491 class StoreLNode : public StoreNode {
492 virtual uint hash() const { return StoreNode::hash() + _require_atomic_access; }
493 virtual uint cmp( const Node &n ) const {
494 return _require_atomic_access == ((StoreLNode&)n)._require_atomic_access
495 && StoreNode::cmp(n);
496 }
497 virtual uint size_of() const { return sizeof(*this); }
498 const bool _require_atomic_access; // is piecewise store forbidden?
500 public:
501 StoreLNode( Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val,
502 bool require_atomic_access = false )
503 : StoreNode(c,mem,adr,at,val)
504 , _require_atomic_access(require_atomic_access)
505 {}
506 virtual int Opcode() const;
507 virtual BasicType memory_type() const { return T_LONG; }
508 bool require_atomic_access() { return _require_atomic_access; }
509 static StoreLNode* make_atomic(Compile *C, Node* ctl, Node* mem, Node* adr, const TypePtr* adr_type, Node* val);
510 #ifndef PRODUCT
511 virtual void dump_spec(outputStream *st) const {
512 StoreNode::dump_spec(st);
513 if (_require_atomic_access) st->print(" Atomic!");
514 }
515 #endif
516 };
518 //------------------------------StoreFNode-------------------------------------
519 // Store float to memory
520 class StoreFNode : public StoreNode {
521 public:
522 StoreFNode( Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val ) : StoreNode(c,mem,adr,at,val) {}
523 virtual int Opcode() const;
524 virtual BasicType memory_type() const { return T_FLOAT; }
525 };
527 //------------------------------StoreDNode-------------------------------------
528 // Store double to memory
529 class StoreDNode : public StoreNode {
530 public:
531 StoreDNode( Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val ) : StoreNode(c,mem,adr,at,val) {}
532 virtual int Opcode() const;
533 virtual BasicType memory_type() const { return T_DOUBLE; }
534 };
536 //------------------------------StorePNode-------------------------------------
537 // Store pointer to memory
538 class StorePNode : public StoreNode {
539 public:
540 StorePNode( Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val ) : StoreNode(c,mem,adr,at,val) {}
541 virtual int Opcode() const;
542 virtual BasicType memory_type() const { return T_ADDRESS; }
543 };
545 //------------------------------StoreNNode-------------------------------------
546 // Store narrow oop to memory
547 class StoreNNode : public StoreNode {
548 public:
549 StoreNNode( Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val ) : StoreNode(c,mem,adr,at,val) {}
550 virtual int Opcode() const;
551 virtual BasicType memory_type() const { return T_NARROWOOP; }
552 };
554 //------------------------------StoreCMNode-----------------------------------
555 // Store card-mark byte to memory for CM
556 // The last StoreCM before a SafePoint must be preserved and occur after its "oop" store
557 // Preceeding equivalent StoreCMs may be eliminated.
558 class StoreCMNode : public StoreNode {
559 public:
560 StoreCMNode( Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, Node *oop_store ) : StoreNode(c,mem,adr,at,val,oop_store) {}
561 virtual int Opcode() const;
562 virtual Node *Identity( PhaseTransform *phase );
563 virtual const Type *Value( PhaseTransform *phase ) const;
564 virtual BasicType memory_type() const { return T_VOID; } // unspecific
565 };
567 //------------------------------LoadPLockedNode---------------------------------
568 // Load-locked a pointer from memory (either object or array).
569 // On Sparc & Intel this is implemented as a normal pointer load.
570 // On PowerPC and friends it's a real load-locked.
571 class LoadPLockedNode : public LoadPNode {
572 public:
573 LoadPLockedNode( Node *c, Node *mem, Node *adr )
574 : LoadPNode(c,mem,adr,TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM) {}
575 virtual int Opcode() const;
576 virtual int store_Opcode() const { return Op_StorePConditional; }
577 virtual bool depends_only_on_test() const { return true; }
578 };
580 //------------------------------LoadLLockedNode---------------------------------
581 // Load-locked a pointer from memory (either object or array).
582 // On Sparc & Intel this is implemented as a normal long load.
583 class LoadLLockedNode : public LoadLNode {
584 public:
585 LoadLLockedNode( Node *c, Node *mem, Node *adr )
586 : LoadLNode(c,mem,adr,TypeRawPtr::BOTTOM, TypeLong::LONG) {}
587 virtual int Opcode() const;
588 virtual int store_Opcode() const { return Op_StoreLConditional; }
589 };
591 //------------------------------SCMemProjNode---------------------------------------
592 // This class defines a projection of the memory state of a store conditional node.
593 // These nodes return a value, but also update memory.
594 class SCMemProjNode : public ProjNode {
595 public:
596 enum {SCMEMPROJCON = (uint)-2};
597 SCMemProjNode( Node *src) : ProjNode( src, SCMEMPROJCON) { }
598 virtual int Opcode() const;
599 virtual bool is_CFG() const { return false; }
600 virtual const Type *bottom_type() const {return Type::MEMORY;}
601 virtual const TypePtr *adr_type() const { return in(0)->in(MemNode::Memory)->adr_type();}
602 virtual uint ideal_reg() const { return 0;} // memory projections don't have a register
603 virtual const Type *Value( PhaseTransform *phase ) const;
604 #ifndef PRODUCT
605 virtual void dump_spec(outputStream *st) const {};
606 #endif
607 };
609 //------------------------------LoadStoreNode---------------------------
610 class LoadStoreNode : public Node {
611 public:
612 enum {
613 ExpectedIn = MemNode::ValueIn+1 // One more input than MemNode
614 };
615 LoadStoreNode( Node *c, Node *mem, Node *adr, Node *val, Node *ex);
616 virtual bool depends_only_on_test() const { return false; }
617 virtual const Type *bottom_type() const { return TypeInt::BOOL; }
618 virtual uint ideal_reg() const { return Op_RegI; }
619 virtual uint match_edge(uint idx) const { return idx == MemNode::Address || idx == MemNode::ValueIn; }
620 };
622 //------------------------------StorePConditionalNode---------------------------
623 // Conditionally store pointer to memory, if no change since prior
624 // load-locked. Sets flags for success or failure of the store.
625 class StorePConditionalNode : public LoadStoreNode {
626 public:
627 StorePConditionalNode( Node *c, Node *mem, Node *adr, Node *val, Node *ll ) : LoadStoreNode(c, mem, adr, val, ll) { }
628 virtual int Opcode() const;
629 // Produces flags
630 virtual uint ideal_reg() const { return Op_RegFlags; }
631 };
633 //------------------------------StoreLConditionalNode---------------------------
634 // Conditionally store long to memory, if no change since prior
635 // load-locked. Sets flags for success or failure of the store.
636 class StoreLConditionalNode : public LoadStoreNode {
637 public:
638 StoreLConditionalNode( Node *c, Node *mem, Node *adr, Node *val, Node *ll ) : LoadStoreNode(c, mem, adr, val, ll) { }
639 virtual int Opcode() const;
640 };
643 //------------------------------CompareAndSwapLNode---------------------------
644 class CompareAndSwapLNode : public LoadStoreNode {
645 public:
646 CompareAndSwapLNode( Node *c, Node *mem, Node *adr, Node *val, Node *ex) : LoadStoreNode(c, mem, adr, val, ex) { }
647 virtual int Opcode() const;
648 };
651 //------------------------------CompareAndSwapINode---------------------------
652 class CompareAndSwapINode : public LoadStoreNode {
653 public:
654 CompareAndSwapINode( Node *c, Node *mem, Node *adr, Node *val, Node *ex) : LoadStoreNode(c, mem, adr, val, ex) { }
655 virtual int Opcode() const;
656 };
659 //------------------------------CompareAndSwapPNode---------------------------
660 class CompareAndSwapPNode : public LoadStoreNode {
661 public:
662 CompareAndSwapPNode( Node *c, Node *mem, Node *adr, Node *val, Node *ex) : LoadStoreNode(c, mem, adr, val, ex) { }
663 virtual int Opcode() const;
664 };
666 //------------------------------CompareAndSwapNNode---------------------------
667 class CompareAndSwapNNode : public LoadStoreNode {
668 public:
669 CompareAndSwapNNode( Node *c, Node *mem, Node *adr, Node *val, Node *ex) : LoadStoreNode(c, mem, adr, val, ex) { }
670 virtual int Opcode() const;
671 };
673 //------------------------------ClearArray-------------------------------------
674 class ClearArrayNode: public Node {
675 public:
676 ClearArrayNode( Node *ctrl, Node *arymem, Node *word_cnt, Node *base ) : Node(ctrl,arymem,word_cnt,base) {}
677 virtual int Opcode() const;
678 virtual const Type *bottom_type() const { return Type::MEMORY; }
679 // ClearArray modifies array elements, and so affects only the
680 // array memory addressed by the bottom_type of its base address.
681 virtual const class TypePtr *adr_type() const;
682 virtual Node *Identity( PhaseTransform *phase );
683 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
684 virtual uint match_edge(uint idx) const;
686 // Clear the given area of an object or array.
687 // The start offset must always be aligned mod BytesPerInt.
688 // The end offset must always be aligned mod BytesPerLong.
689 // Return the new memory.
690 static Node* clear_memory(Node* control, Node* mem, Node* dest,
691 intptr_t start_offset,
692 intptr_t end_offset,
693 PhaseGVN* phase);
694 static Node* clear_memory(Node* control, Node* mem, Node* dest,
695 intptr_t start_offset,
696 Node* end_offset,
697 PhaseGVN* phase);
698 static Node* clear_memory(Node* control, Node* mem, Node* dest,
699 Node* start_offset,
700 Node* end_offset,
701 PhaseGVN* phase);
702 };
704 //------------------------------StrComp-------------------------------------
705 class StrCompNode: public Node {
706 public:
707 StrCompNode(Node *control,
708 Node* char_array_mem,
709 Node* value_mem,
710 Node* count_mem,
711 Node* offset_mem,
712 Node* s1, Node* s2): Node(control,
713 char_array_mem,
714 value_mem,
715 count_mem,
716 offset_mem,
717 s1, s2) {};
718 virtual int Opcode() const;
719 virtual bool depends_only_on_test() const { return false; }
720 virtual const Type* bottom_type() const { return TypeInt::INT; }
721 // a StrCompNode (conservatively) aliases with everything:
722 virtual const TypePtr* adr_type() const { return TypePtr::BOTTOM; }
723 virtual uint match_edge(uint idx) const;
724 virtual uint ideal_reg() const { return Op_RegI; }
725 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
726 };
728 //------------------------------AryEq---------------------------------------
729 class AryEqNode: public Node {
730 public:
731 AryEqNode(Node *control, Node* s1, Node* s2): Node(control, s1, s2) {};
732 virtual int Opcode() const;
733 virtual bool depends_only_on_test() const { return false; }
734 virtual const Type* bottom_type() const { return TypeInt::BOOL; }
735 virtual const TypePtr* adr_type() const { return TypeAryPtr::CHARS; }
736 virtual uint ideal_reg() const { return Op_RegI; }
737 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
738 };
740 //------------------------------MemBar-----------------------------------------
741 // There are different flavors of Memory Barriers to match the Java Memory
742 // Model. Monitor-enter and volatile-load act as Aquires: no following ref
743 // can be moved to before them. We insert a MemBar-Acquire after a FastLock or
744 // volatile-load. Monitor-exit and volatile-store act as Release: no
745 // preceeding ref can be moved to after them. We insert a MemBar-Release
746 // before a FastUnlock or volatile-store. All volatiles need to be
747 // serialized, so we follow all volatile-stores with a MemBar-Volatile to
748 // seperate it from any following volatile-load.
749 class MemBarNode: public MultiNode {
750 virtual uint hash() const ; // { return NO_HASH; }
751 virtual uint cmp( const Node &n ) const ; // Always fail, except on self
753 virtual uint size_of() const { return sizeof(*this); }
754 // Memory type this node is serializing. Usually either rawptr or bottom.
755 const TypePtr* _adr_type;
757 public:
758 enum {
759 Precedent = TypeFunc::Parms // optional edge to force precedence
760 };
761 MemBarNode(Compile* C, int alias_idx, Node* precedent);
762 virtual int Opcode() const = 0;
763 virtual const class TypePtr *adr_type() const { return _adr_type; }
764 virtual const Type *Value( PhaseTransform *phase ) const;
765 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
766 virtual uint match_edge(uint idx) const { return 0; }
767 virtual const Type *bottom_type() const { return TypeTuple::MEMBAR; }
768 virtual Node *match( const ProjNode *proj, const Matcher *m );
769 // Factory method. Builds a wide or narrow membar.
770 // Optional 'precedent' becomes an extra edge if not null.
771 static MemBarNode* make(Compile* C, int opcode,
772 int alias_idx = Compile::AliasIdxBot,
773 Node* precedent = NULL);
774 };
776 // "Acquire" - no following ref can move before (but earlier refs can
777 // follow, like an early Load stalled in cache). Requires multi-cpu
778 // visibility. Inserted after a volatile load or FastLock.
779 class MemBarAcquireNode: public MemBarNode {
780 public:
781 MemBarAcquireNode(Compile* C, int alias_idx, Node* precedent)
782 : MemBarNode(C, alias_idx, precedent) {}
783 virtual int Opcode() const;
784 };
786 // "Release" - no earlier ref can move after (but later refs can move
787 // up, like a speculative pipelined cache-hitting Load). Requires
788 // multi-cpu visibility. Inserted before a volatile store or FastUnLock.
789 class MemBarReleaseNode: public MemBarNode {
790 public:
791 MemBarReleaseNode(Compile* C, int alias_idx, Node* precedent)
792 : MemBarNode(C, alias_idx, precedent) {}
793 virtual int Opcode() const;
794 };
796 // Ordering between a volatile store and a following volatile load.
797 // Requires multi-CPU visibility?
798 class MemBarVolatileNode: public MemBarNode {
799 public:
800 MemBarVolatileNode(Compile* C, int alias_idx, Node* precedent)
801 : MemBarNode(C, alias_idx, precedent) {}
802 virtual int Opcode() const;
803 };
805 // Ordering within the same CPU. Used to order unsafe memory references
806 // inside the compiler when we lack alias info. Not needed "outside" the
807 // compiler because the CPU does all the ordering for us.
808 class MemBarCPUOrderNode: public MemBarNode {
809 public:
810 MemBarCPUOrderNode(Compile* C, int alias_idx, Node* precedent)
811 : MemBarNode(C, alias_idx, precedent) {}
812 virtual int Opcode() const;
813 virtual uint ideal_reg() const { return 0; } // not matched in the AD file
814 };
816 // Isolation of object setup after an AllocateNode and before next safepoint.
817 // (See comment in memnode.cpp near InitializeNode::InitializeNode for semantics.)
818 class InitializeNode: public MemBarNode {
819 friend class AllocateNode;
821 bool _is_complete;
823 public:
824 enum {
825 Control = TypeFunc::Control,
826 Memory = TypeFunc::Memory, // MergeMem for states affected by this op
827 RawAddress = TypeFunc::Parms+0, // the newly-allocated raw address
828 RawStores = TypeFunc::Parms+1 // zero or more stores (or TOP)
829 };
831 InitializeNode(Compile* C, int adr_type, Node* rawoop);
832 virtual int Opcode() const;
833 virtual uint size_of() const { return sizeof(*this); }
834 virtual uint ideal_reg() const { return 0; } // not matched in the AD file
835 virtual const RegMask &in_RegMask(uint) const; // mask for RawAddress
837 // Manage incoming memory edges via a MergeMem on in(Memory):
838 Node* memory(uint alias_idx);
840 // The raw memory edge coming directly from the Allocation.
841 // The contents of this memory are *always* all-zero-bits.
842 Node* zero_memory() { return memory(Compile::AliasIdxRaw); }
844 // Return the corresponding allocation for this initialization (or null if none).
845 // (Note: Both InitializeNode::allocation and AllocateNode::initialization
846 // are defined in graphKit.cpp, which sets up the bidirectional relation.)
847 AllocateNode* allocation();
849 // Anything other than zeroing in this init?
850 bool is_non_zero();
852 // An InitializeNode must completed before macro expansion is done.
853 // Completion requires that the AllocateNode must be followed by
854 // initialization of the new memory to zero, then to any initializers.
855 bool is_complete() { return _is_complete; }
857 // Mark complete. (Must not yet be complete.)
858 void set_complete(PhaseGVN* phase);
860 #ifdef ASSERT
861 // ensure all non-degenerate stores are ordered and non-overlapping
862 bool stores_are_sane(PhaseTransform* phase);
863 #endif //ASSERT
865 // See if this store can be captured; return offset where it initializes.
866 // Return 0 if the store cannot be moved (any sort of problem).
867 intptr_t can_capture_store(StoreNode* st, PhaseTransform* phase);
869 // Capture another store; reformat it to write my internal raw memory.
870 // Return the captured copy, else NULL if there is some sort of problem.
871 Node* capture_store(StoreNode* st, intptr_t start, PhaseTransform* phase);
873 // Find captured store which corresponds to the range [start..start+size).
874 // Return my own memory projection (meaning the initial zero bits)
875 // if there is no such store. Return NULL if there is a problem.
876 Node* find_captured_store(intptr_t start, int size_in_bytes, PhaseTransform* phase);
878 // Called when the associated AllocateNode is expanded into CFG.
879 Node* complete_stores(Node* rawctl, Node* rawmem, Node* rawptr,
880 intptr_t header_size, Node* size_in_bytes,
881 PhaseGVN* phase);
883 private:
884 void remove_extra_zeroes();
886 // Find out where a captured store should be placed (or already is placed).
887 int captured_store_insertion_point(intptr_t start, int size_in_bytes,
888 PhaseTransform* phase);
890 static intptr_t get_store_offset(Node* st, PhaseTransform* phase);
892 Node* make_raw_address(intptr_t offset, PhaseTransform* phase);
894 bool detect_init_independence(Node* n, bool st_is_pinned, int& count);
896 void coalesce_subword_stores(intptr_t header_size, Node* size_in_bytes,
897 PhaseGVN* phase);
899 intptr_t find_next_fullword_store(uint i, PhaseGVN* phase);
900 };
902 //------------------------------MergeMem---------------------------------------
903 // (See comment in memnode.cpp near MergeMemNode::MergeMemNode for semantics.)
904 class MergeMemNode: public Node {
905 virtual uint hash() const ; // { return NO_HASH; }
906 virtual uint cmp( const Node &n ) const ; // Always fail, except on self
907 friend class MergeMemStream;
908 MergeMemNode(Node* def); // clients use MergeMemNode::make
910 public:
911 // If the input is a whole memory state, clone it with all its slices intact.
912 // Otherwise, make a new memory state with just that base memory input.
913 // In either case, the result is a newly created MergeMem.
914 static MergeMemNode* make(Compile* C, Node* base_memory);
916 virtual int Opcode() const;
917 virtual Node *Identity( PhaseTransform *phase );
918 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
919 virtual uint ideal_reg() const { return NotAMachineReg; }
920 virtual uint match_edge(uint idx) const { return 0; }
921 virtual const RegMask &out_RegMask() const;
922 virtual const Type *bottom_type() const { return Type::MEMORY; }
923 virtual const TypePtr *adr_type() const { return TypePtr::BOTTOM; }
924 // sparse accessors
925 // Fetch the previously stored "set_memory_at", or else the base memory.
926 // (Caller should clone it if it is a phi-nest.)
927 Node* memory_at(uint alias_idx) const;
928 // set the memory, regardless of its previous value
929 void set_memory_at(uint alias_idx, Node* n);
930 // the "base" is the memory that provides the non-finite support
931 Node* base_memory() const { return in(Compile::AliasIdxBot); }
932 // warning: setting the base can implicitly set any of the other slices too
933 void set_base_memory(Node* def);
934 // sentinel value which denotes a copy of the base memory:
935 Node* empty_memory() const { return in(Compile::AliasIdxTop); }
936 static Node* make_empty_memory(); // where the sentinel comes from
937 bool is_empty_memory(Node* n) const { assert((n == empty_memory()) == n->is_top(), "sanity"); return n->is_top(); }
938 // hook for the iterator, to perform any necessary setup
939 void iteration_setup(const MergeMemNode* other = NULL);
940 // push sentinels until I am at least as long as the other (semantic no-op)
941 void grow_to_match(const MergeMemNode* other);
942 bool verify_sparse() const PRODUCT_RETURN0;
943 #ifndef PRODUCT
944 virtual void dump_spec(outputStream *st) const;
945 #endif
946 };
948 class MergeMemStream : public StackObj {
949 private:
950 MergeMemNode* _mm;
951 const MergeMemNode* _mm2; // optional second guy, contributes non-empty iterations
952 Node* _mm_base; // loop-invariant base memory of _mm
953 int _idx;
954 int _cnt;
955 Node* _mem;
956 Node* _mem2;
957 int _cnt2;
959 void init(MergeMemNode* mm, const MergeMemNode* mm2 = NULL) {
960 // subsume_node will break sparseness at times, whenever a memory slice
961 // folds down to a copy of the base ("fat") memory. In such a case,
962 // the raw edge will update to base, although it should be top.
963 // This iterator will recognize either top or base_memory as an
964 // "empty" slice. See is_empty, is_empty2, and next below.
965 //
966 // The sparseness property is repaired in MergeMemNode::Ideal.
967 // As long as access to a MergeMem goes through this iterator
968 // or the memory_at accessor, flaws in the sparseness will
969 // never be observed.
970 //
971 // Also, iteration_setup repairs sparseness.
972 assert(mm->verify_sparse(), "please, no dups of base");
973 assert(mm2==NULL || mm2->verify_sparse(), "please, no dups of base");
975 _mm = mm;
976 _mm_base = mm->base_memory();
977 _mm2 = mm2;
978 _cnt = mm->req();
979 _idx = Compile::AliasIdxBot-1; // start at the base memory
980 _mem = NULL;
981 _mem2 = NULL;
982 }
984 #ifdef ASSERT
985 Node* check_memory() const {
986 if (at_base_memory())
987 return _mm->base_memory();
988 else if ((uint)_idx < _mm->req() && !_mm->in(_idx)->is_top())
989 return _mm->memory_at(_idx);
990 else
991 return _mm_base;
992 }
993 Node* check_memory2() const {
994 return at_base_memory()? _mm2->base_memory(): _mm2->memory_at(_idx);
995 }
996 #endif
998 static bool match_memory(Node* mem, const MergeMemNode* mm, int idx) PRODUCT_RETURN0;
999 void assert_synch() const {
1000 assert(!_mem || _idx >= _cnt || match_memory(_mem, _mm, _idx),
1001 "no side-effects except through the stream");
1002 }
1004 public:
1006 // expected usages:
1007 // for (MergeMemStream mms(mem->is_MergeMem()); next_non_empty(); ) { ... }
1008 // for (MergeMemStream mms(mem1, mem2); next_non_empty2(); ) { ... }
1010 // iterate over one merge
1011 MergeMemStream(MergeMemNode* mm) {
1012 mm->iteration_setup();
1013 init(mm);
1014 debug_only(_cnt2 = 999);
1015 }
1016 // iterate in parallel over two merges
1017 // only iterates through non-empty elements of mm2
1018 MergeMemStream(MergeMemNode* mm, const MergeMemNode* mm2) {
1019 assert(mm2, "second argument must be a MergeMem also");
1020 ((MergeMemNode*)mm2)->iteration_setup(); // update hidden state
1021 mm->iteration_setup(mm2);
1022 init(mm, mm2);
1023 _cnt2 = mm2->req();
1024 }
1025 #ifdef ASSERT
1026 ~MergeMemStream() {
1027 assert_synch();
1028 }
1029 #endif
1031 MergeMemNode* all_memory() const {
1032 return _mm;
1033 }
1034 Node* base_memory() const {
1035 assert(_mm_base == _mm->base_memory(), "no update to base memory, please");
1036 return _mm_base;
1037 }
1038 const MergeMemNode* all_memory2() const {
1039 assert(_mm2 != NULL, "");
1040 return _mm2;
1041 }
1042 bool at_base_memory() const {
1043 return _idx == Compile::AliasIdxBot;
1044 }
1045 int alias_idx() const {
1046 assert(_mem, "must call next 1st");
1047 return _idx;
1048 }
1050 const TypePtr* adr_type() const {
1051 return Compile::current()->get_adr_type(alias_idx());
1052 }
1054 const TypePtr* adr_type(Compile* C) const {
1055 return C->get_adr_type(alias_idx());
1056 }
1057 bool is_empty() const {
1058 assert(_mem, "must call next 1st");
1059 assert(_mem->is_top() == (_mem==_mm->empty_memory()), "correct sentinel");
1060 return _mem->is_top();
1061 }
1062 bool is_empty2() const {
1063 assert(_mem2, "must call next 1st");
1064 assert(_mem2->is_top() == (_mem2==_mm2->empty_memory()), "correct sentinel");
1065 return _mem2->is_top();
1066 }
1067 Node* memory() const {
1068 assert(!is_empty(), "must not be empty");
1069 assert_synch();
1070 return _mem;
1071 }
1072 // get the current memory, regardless of empty or non-empty status
1073 Node* force_memory() const {
1074 assert(!is_empty() || !at_base_memory(), "");
1075 // Use _mm_base to defend against updates to _mem->base_memory().
1076 Node *mem = _mem->is_top() ? _mm_base : _mem;
1077 assert(mem == check_memory(), "");
1078 return mem;
1079 }
1080 Node* memory2() const {
1081 assert(_mem2 == check_memory2(), "");
1082 return _mem2;
1083 }
1084 void set_memory(Node* mem) {
1085 if (at_base_memory()) {
1086 // Note that this does not change the invariant _mm_base.
1087 _mm->set_base_memory(mem);
1088 } else {
1089 _mm->set_memory_at(_idx, mem);
1090 }
1091 _mem = mem;
1092 assert_synch();
1093 }
1095 // Recover from a side effect to the MergeMemNode.
1096 void set_memory() {
1097 _mem = _mm->in(_idx);
1098 }
1100 bool next() { return next(false); }
1101 bool next2() { return next(true); }
1103 bool next_non_empty() { return next_non_empty(false); }
1104 bool next_non_empty2() { return next_non_empty(true); }
1105 // next_non_empty2 can yield states where is_empty() is true
1107 private:
1108 // find the next item, which might be empty
1109 bool next(bool have_mm2) {
1110 assert((_mm2 != NULL) == have_mm2, "use other next");
1111 assert_synch();
1112 if (++_idx < _cnt) {
1113 // Note: This iterator allows _mm to be non-sparse.
1114 // It behaves the same whether _mem is top or base_memory.
1115 _mem = _mm->in(_idx);
1116 if (have_mm2)
1117 _mem2 = _mm2->in((_idx < _cnt2) ? _idx : Compile::AliasIdxTop);
1118 return true;
1119 }
1120 return false;
1121 }
1123 // find the next non-empty item
1124 bool next_non_empty(bool have_mm2) {
1125 while (next(have_mm2)) {
1126 if (!is_empty()) {
1127 // make sure _mem2 is filled in sensibly
1128 if (have_mm2 && _mem2->is_top()) _mem2 = _mm2->base_memory();
1129 return true;
1130 } else if (have_mm2 && !is_empty2()) {
1131 return true; // is_empty() == true
1132 }
1133 }
1134 return false;
1135 }
1136 };
1138 //------------------------------Prefetch---------------------------------------
1140 // Non-faulting prefetch load. Prefetch for many reads.
1141 class PrefetchReadNode : public Node {
1142 public:
1143 PrefetchReadNode(Node *abio, Node *adr) : Node(0,abio,adr) {}
1144 virtual int Opcode() const;
1145 virtual uint ideal_reg() const { return NotAMachineReg; }
1146 virtual uint match_edge(uint idx) const { return idx==2; }
1147 virtual const Type *bottom_type() const { return Type::ABIO; }
1148 };
1150 // Non-faulting prefetch load. Prefetch for many reads & many writes.
1151 class PrefetchWriteNode : public Node {
1152 public:
1153 PrefetchWriteNode(Node *abio, Node *adr) : Node(0,abio,adr) {}
1154 virtual int Opcode() const;
1155 virtual uint ideal_reg() const { return NotAMachineReg; }
1156 virtual uint match_edge(uint idx) const { return idx==2; }
1157 virtual const Type *bottom_type() const { return Type::ABIO; }
1158 };