Thu, 02 Oct 2008 08:37:44 -0700
6667595: Set probability FAIR for pre-, post- loops and ALWAYS for main loop
Summary: Fix loop's probability. Add optimizations to avoid spilling. Change InlineSmallCode to product flag.
Reviewed-by: never
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.
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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 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
245 };
247 //------------------------------LoadLNode--------------------------------------
248 // Load a long from memory
249 class LoadLNode : public LoadNode {
250 virtual uint hash() const { return LoadNode::hash() + _require_atomic_access; }
251 virtual uint cmp( const Node &n ) const {
252 return _require_atomic_access == ((LoadLNode&)n)._require_atomic_access
253 && LoadNode::cmp(n);
254 }
255 virtual uint size_of() const { return sizeof(*this); }
256 const bool _require_atomic_access; // is piecewise load forbidden?
258 public:
259 LoadLNode( Node *c, Node *mem, Node *adr, const TypePtr* at,
260 const TypeLong *tl = TypeLong::LONG,
261 bool require_atomic_access = false )
262 : LoadNode(c,mem,adr,at,tl)
263 , _require_atomic_access(require_atomic_access)
264 {}
265 virtual int Opcode() const;
266 virtual uint ideal_reg() const { return Op_RegL; }
267 virtual int store_Opcode() const { return Op_StoreL; }
268 virtual BasicType memory_type() const { return T_LONG; }
269 bool require_atomic_access() { return _require_atomic_access; }
270 static LoadLNode* make_atomic(Compile *C, Node* ctl, Node* mem, Node* adr, const TypePtr* adr_type, const Type* rt);
271 #ifndef PRODUCT
272 virtual void dump_spec(outputStream *st) const {
273 LoadNode::dump_spec(st);
274 if (_require_atomic_access) st->print(" Atomic!");
275 }
276 #endif
277 };
279 //------------------------------LoadL_unalignedNode----------------------------
280 // Load a long from unaligned memory
281 class LoadL_unalignedNode : public LoadLNode {
282 public:
283 LoadL_unalignedNode( Node *c, Node *mem, Node *adr, const TypePtr* at )
284 : LoadLNode(c,mem,adr,at) {}
285 virtual int Opcode() const;
286 };
288 //------------------------------LoadFNode--------------------------------------
289 // Load a float (64 bits) from memory
290 class LoadFNode : public LoadNode {
291 public:
292 LoadFNode( Node *c, Node *mem, Node *adr, const TypePtr* at, const Type *t = Type::FLOAT )
293 : LoadNode(c,mem,adr,at,t) {}
294 virtual int Opcode() const;
295 virtual uint ideal_reg() const { return Op_RegF; }
296 virtual int store_Opcode() const { return Op_StoreF; }
297 virtual BasicType memory_type() const { return T_FLOAT; }
298 };
300 //------------------------------LoadDNode--------------------------------------
301 // Load a double (64 bits) from memory
302 class LoadDNode : public LoadNode {
303 public:
304 LoadDNode( Node *c, Node *mem, Node *adr, const TypePtr* at, const Type *t = Type::DOUBLE )
305 : LoadNode(c,mem,adr,at,t) {}
306 virtual int Opcode() const;
307 virtual uint ideal_reg() const { return Op_RegD; }
308 virtual int store_Opcode() const { return Op_StoreD; }
309 virtual BasicType memory_type() const { return T_DOUBLE; }
310 };
312 //------------------------------LoadD_unalignedNode----------------------------
313 // Load a double from unaligned memory
314 class LoadD_unalignedNode : public LoadDNode {
315 public:
316 LoadD_unalignedNode( Node *c, Node *mem, Node *adr, const TypePtr* at )
317 : LoadDNode(c,mem,adr,at) {}
318 virtual int Opcode() const;
319 };
321 //------------------------------LoadPNode--------------------------------------
322 // Load a pointer from memory (either object or array)
323 class LoadPNode : public LoadNode {
324 public:
325 LoadPNode( Node *c, Node *mem, Node *adr, const TypePtr *at, const TypePtr* t )
326 : LoadNode(c,mem,adr,at,t) {}
327 virtual int Opcode() const;
328 virtual uint ideal_reg() const { return Op_RegP; }
329 virtual int store_Opcode() const { return Op_StoreP; }
330 virtual BasicType memory_type() const { return T_ADDRESS; }
331 // depends_only_on_test is almost always true, and needs to be almost always
332 // true to enable key hoisting & commoning optimizations. However, for the
333 // special case of RawPtr loads from TLS top & end, the control edge carries
334 // the dependence preventing hoisting past a Safepoint instead of the memory
335 // edge. (An unfortunate consequence of having Safepoints not set Raw
336 // Memory; itself an unfortunate consequence of having Nodes which produce
337 // results (new raw memory state) inside of loops preventing all manner of
338 // other optimizations). Basically, it's ugly but so is the alternative.
339 // See comment in macro.cpp, around line 125 expand_allocate_common().
340 virtual bool depends_only_on_test() const { return adr_type() != TypeRawPtr::BOTTOM; }
341 };
344 //------------------------------LoadNNode--------------------------------------
345 // Load a narrow oop from memory (either object or array)
346 class LoadNNode : public LoadNode {
347 public:
348 LoadNNode( Node *c, Node *mem, Node *adr, const TypePtr *at, const Type* t )
349 : LoadNode(c,mem,adr,at,t) {}
350 virtual int Opcode() const;
351 virtual uint ideal_reg() const { return Op_RegN; }
352 virtual int store_Opcode() const { return Op_StoreN; }
353 virtual BasicType memory_type() const { return T_NARROWOOP; }
354 // depends_only_on_test is almost always true, and needs to be almost always
355 // true to enable key hoisting & commoning optimizations. However, for the
356 // special case of RawPtr loads from TLS top & end, the control edge carries
357 // the dependence preventing hoisting past a Safepoint instead of the memory
358 // edge. (An unfortunate consequence of having Safepoints not set Raw
359 // Memory; itself an unfortunate consequence of having Nodes which produce
360 // results (new raw memory state) inside of loops preventing all manner of
361 // other optimizations). Basically, it's ugly but so is the alternative.
362 // See comment in macro.cpp, around line 125 expand_allocate_common().
363 virtual bool depends_only_on_test() const { return adr_type() != TypeRawPtr::BOTTOM; }
364 };
366 //------------------------------LoadKlassNode----------------------------------
367 // Load a Klass from an object
368 class LoadKlassNode : public LoadPNode {
369 public:
370 LoadKlassNode( Node *c, Node *mem, Node *adr, const TypePtr *at, const TypeKlassPtr *tk )
371 : LoadPNode(c,mem,adr,at,tk) {}
372 virtual int Opcode() const;
373 virtual const Type *Value( PhaseTransform *phase ) const;
374 virtual Node *Identity( PhaseTransform *phase );
375 virtual bool depends_only_on_test() const { return true; }
377 // Polymorphic factory method:
378 static Node* make( PhaseGVN& gvn, Node *mem, Node *adr, const TypePtr* at,
379 const TypeKlassPtr *tk = TypeKlassPtr::OBJECT );
380 };
382 //------------------------------LoadNKlassNode---------------------------------
383 // Load a narrow Klass from an object.
384 class LoadNKlassNode : public LoadNNode {
385 public:
386 LoadNKlassNode( Node *c, Node *mem, Node *adr, const TypePtr *at, const TypeNarrowOop *tk )
387 : LoadNNode(c,mem,adr,at,tk) {}
388 virtual int Opcode() const;
389 virtual uint ideal_reg() const { return Op_RegN; }
390 virtual int store_Opcode() const { return Op_StoreN; }
391 virtual BasicType memory_type() const { return T_NARROWOOP; }
393 virtual const Type *Value( PhaseTransform *phase ) const;
394 virtual Node *Identity( PhaseTransform *phase );
395 virtual bool depends_only_on_test() const { return true; }
396 };
399 //------------------------------LoadSNode--------------------------------------
400 // Load a short (16bits signed) from memory
401 class LoadSNode : public LoadNode {
402 public:
403 LoadSNode( Node *c, Node *mem, Node *adr, const TypePtr* at, const TypeInt *ti = TypeInt::SHORT )
404 : LoadNode(c,mem,adr,at,ti) {}
405 virtual int Opcode() const;
406 virtual uint ideal_reg() const { return Op_RegI; }
407 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
408 virtual int store_Opcode() const { return Op_StoreC; }
409 virtual BasicType memory_type() const { return T_SHORT; }
410 };
412 //------------------------------StoreNode--------------------------------------
413 // Store value; requires Store, Address and Value
414 class StoreNode : public MemNode {
415 protected:
416 virtual uint cmp( const Node &n ) const;
417 virtual bool depends_only_on_test() const { return false; }
419 Node *Ideal_masked_input (PhaseGVN *phase, uint mask);
420 Node *Ideal_sign_extended_input(PhaseGVN *phase, int num_bits);
422 public:
423 StoreNode( Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val )
424 : MemNode(c,mem,adr,at,val) {
425 init_class_id(Class_Store);
426 }
427 StoreNode( Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, Node *oop_store )
428 : MemNode(c,mem,adr,at,val,oop_store) {
429 init_class_id(Class_Store);
430 }
432 // Polymorphic factory method:
433 static StoreNode* make( PhaseGVN& gvn, Node *c, Node *mem, Node *adr,
434 const TypePtr* at, Node *val, BasicType bt );
436 virtual uint hash() const; // Check the type
438 // If the store is to Field memory and the pointer is non-null, we can
439 // zero out the control input.
440 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
442 // Compute a new Type for this node. Basically we just do the pre-check,
443 // then call the virtual add() to set the type.
444 virtual const Type *Value( PhaseTransform *phase ) const;
446 // Check for identity function on memory (Load then Store at same address)
447 virtual Node *Identity( PhaseTransform *phase );
449 // Do not match memory edge
450 virtual uint match_edge(uint idx) const;
452 virtual const Type *bottom_type() const; // returns Type::MEMORY
454 // Map a store opcode to its corresponding own opcode, trivially.
455 virtual int store_Opcode() const { return Opcode(); }
457 // have all possible loads of the value stored been optimized away?
458 bool value_never_loaded(PhaseTransform *phase) const;
459 };
461 //------------------------------StoreBNode-------------------------------------
462 // Store byte to memory
463 class StoreBNode : public StoreNode {
464 public:
465 StoreBNode( Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val ) : StoreNode(c,mem,adr,at,val) {}
466 virtual int Opcode() const;
467 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
468 virtual BasicType memory_type() const { return T_BYTE; }
469 };
471 //------------------------------StoreCNode-------------------------------------
472 // Store char/short to memory
473 class StoreCNode : public StoreNode {
474 public:
475 StoreCNode( Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val ) : StoreNode(c,mem,adr,at,val) {}
476 virtual int Opcode() const;
477 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
478 virtual BasicType memory_type() const { return T_CHAR; }
479 };
481 //------------------------------StoreINode-------------------------------------
482 // Store int to memory
483 class StoreINode : public StoreNode {
484 public:
485 StoreINode( Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val ) : StoreNode(c,mem,adr,at,val) {}
486 virtual int Opcode() const;
487 virtual BasicType memory_type() const { return T_INT; }
488 };
490 //------------------------------StoreLNode-------------------------------------
491 // Store long to memory
492 class StoreLNode : public StoreNode {
493 virtual uint hash() const { return StoreNode::hash() + _require_atomic_access; }
494 virtual uint cmp( const Node &n ) const {
495 return _require_atomic_access == ((StoreLNode&)n)._require_atomic_access
496 && StoreNode::cmp(n);
497 }
498 virtual uint size_of() const { return sizeof(*this); }
499 const bool _require_atomic_access; // is piecewise store forbidden?
501 public:
502 StoreLNode( Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val,
503 bool require_atomic_access = false )
504 : StoreNode(c,mem,adr,at,val)
505 , _require_atomic_access(require_atomic_access)
506 {}
507 virtual int Opcode() const;
508 virtual BasicType memory_type() const { return T_LONG; }
509 bool require_atomic_access() { return _require_atomic_access; }
510 static StoreLNode* make_atomic(Compile *C, Node* ctl, Node* mem, Node* adr, const TypePtr* adr_type, Node* val);
511 #ifndef PRODUCT
512 virtual void dump_spec(outputStream *st) const {
513 StoreNode::dump_spec(st);
514 if (_require_atomic_access) st->print(" Atomic!");
515 }
516 #endif
517 };
519 //------------------------------StoreFNode-------------------------------------
520 // Store float to memory
521 class StoreFNode : public StoreNode {
522 public:
523 StoreFNode( Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val ) : StoreNode(c,mem,adr,at,val) {}
524 virtual int Opcode() const;
525 virtual BasicType memory_type() const { return T_FLOAT; }
526 };
528 //------------------------------StoreDNode-------------------------------------
529 // Store double to memory
530 class StoreDNode : public StoreNode {
531 public:
532 StoreDNode( Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val ) : StoreNode(c,mem,adr,at,val) {}
533 virtual int Opcode() const;
534 virtual BasicType memory_type() const { return T_DOUBLE; }
535 };
537 //------------------------------StorePNode-------------------------------------
538 // Store pointer to memory
539 class StorePNode : public StoreNode {
540 public:
541 StorePNode( Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val ) : StoreNode(c,mem,adr,at,val) {}
542 virtual int Opcode() const;
543 virtual BasicType memory_type() const { return T_ADDRESS; }
544 };
546 //------------------------------StoreNNode-------------------------------------
547 // Store narrow oop to memory
548 class StoreNNode : public StoreNode {
549 public:
550 StoreNNode( Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val ) : StoreNode(c,mem,adr,at,val) {}
551 virtual int Opcode() const;
552 virtual BasicType memory_type() const { return T_NARROWOOP; }
553 };
555 //------------------------------StoreCMNode-----------------------------------
556 // Store card-mark byte to memory for CM
557 // The last StoreCM before a SafePoint must be preserved and occur after its "oop" store
558 // Preceeding equivalent StoreCMs may be eliminated.
559 class StoreCMNode : public StoreNode {
560 public:
561 StoreCMNode( Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, Node *oop_store ) : StoreNode(c,mem,adr,at,val,oop_store) {}
562 virtual int Opcode() const;
563 virtual Node *Identity( PhaseTransform *phase );
564 virtual const Type *Value( PhaseTransform *phase ) const;
565 virtual BasicType memory_type() const { return T_VOID; } // unspecific
566 };
568 //------------------------------LoadPLockedNode---------------------------------
569 // Load-locked a pointer from memory (either object or array).
570 // On Sparc & Intel this is implemented as a normal pointer load.
571 // On PowerPC and friends it's a real load-locked.
572 class LoadPLockedNode : public LoadPNode {
573 public:
574 LoadPLockedNode( Node *c, Node *mem, Node *adr )
575 : LoadPNode(c,mem,adr,TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM) {}
576 virtual int Opcode() const;
577 virtual int store_Opcode() const { return Op_StorePConditional; }
578 virtual bool depends_only_on_test() const { return true; }
579 };
581 //------------------------------LoadLLockedNode---------------------------------
582 // Load-locked a pointer from memory (either object or array).
583 // On Sparc & Intel this is implemented as a normal long load.
584 class LoadLLockedNode : public LoadLNode {
585 public:
586 LoadLLockedNode( Node *c, Node *mem, Node *adr )
587 : LoadLNode(c,mem,adr,TypeRawPtr::BOTTOM, TypeLong::LONG) {}
588 virtual int Opcode() const;
589 virtual int store_Opcode() const { return Op_StoreLConditional; }
590 };
592 //------------------------------SCMemProjNode---------------------------------------
593 // This class defines a projection of the memory state of a store conditional node.
594 // These nodes return a value, but also update memory.
595 class SCMemProjNode : public ProjNode {
596 public:
597 enum {SCMEMPROJCON = (uint)-2};
598 SCMemProjNode( Node *src) : ProjNode( src, SCMEMPROJCON) { }
599 virtual int Opcode() const;
600 virtual bool is_CFG() const { return false; }
601 virtual const Type *bottom_type() const {return Type::MEMORY;}
602 virtual const TypePtr *adr_type() const { return in(0)->in(MemNode::Memory)->adr_type();}
603 virtual uint ideal_reg() const { return 0;} // memory projections don't have a register
604 virtual const Type *Value( PhaseTransform *phase ) const;
605 #ifndef PRODUCT
606 virtual void dump_spec(outputStream *st) const {};
607 #endif
608 };
610 //------------------------------LoadStoreNode---------------------------
611 // Note: is_Mem() method returns 'true' for this class.
612 class LoadStoreNode : public Node {
613 public:
614 enum {
615 ExpectedIn = MemNode::ValueIn+1 // One more input than MemNode
616 };
617 LoadStoreNode( Node *c, Node *mem, Node *adr, Node *val, Node *ex);
618 virtual bool depends_only_on_test() const { return false; }
619 virtual const Type *bottom_type() const { return TypeInt::BOOL; }
620 virtual uint ideal_reg() const { return Op_RegI; }
621 virtual uint match_edge(uint idx) const { return idx == MemNode::Address || idx == MemNode::ValueIn; }
622 };
624 //------------------------------StorePConditionalNode---------------------------
625 // Conditionally store pointer to memory, if no change since prior
626 // load-locked. Sets flags for success or failure of the store.
627 class StorePConditionalNode : public LoadStoreNode {
628 public:
629 StorePConditionalNode( Node *c, Node *mem, Node *adr, Node *val, Node *ll ) : LoadStoreNode(c, mem, adr, val, ll) { }
630 virtual int Opcode() const;
631 // Produces flags
632 virtual uint ideal_reg() const { return Op_RegFlags; }
633 };
635 //------------------------------StoreLConditionalNode---------------------------
636 // Conditionally store long to memory, if no change since prior
637 // load-locked. Sets flags for success or failure of the store.
638 class StoreLConditionalNode : public LoadStoreNode {
639 public:
640 StoreLConditionalNode( Node *c, Node *mem, Node *adr, Node *val, Node *ll ) : LoadStoreNode(c, mem, adr, val, ll) { }
641 virtual int Opcode() const;
642 };
645 //------------------------------CompareAndSwapLNode---------------------------
646 class CompareAndSwapLNode : public LoadStoreNode {
647 public:
648 CompareAndSwapLNode( Node *c, Node *mem, Node *adr, Node *val, Node *ex) : LoadStoreNode(c, mem, adr, val, ex) { }
649 virtual int Opcode() const;
650 };
653 //------------------------------CompareAndSwapINode---------------------------
654 class CompareAndSwapINode : public LoadStoreNode {
655 public:
656 CompareAndSwapINode( Node *c, Node *mem, Node *adr, Node *val, Node *ex) : LoadStoreNode(c, mem, adr, val, ex) { }
657 virtual int Opcode() const;
658 };
661 //------------------------------CompareAndSwapPNode---------------------------
662 class CompareAndSwapPNode : public LoadStoreNode {
663 public:
664 CompareAndSwapPNode( Node *c, Node *mem, Node *adr, Node *val, Node *ex) : LoadStoreNode(c, mem, adr, val, ex) { }
665 virtual int Opcode() const;
666 };
668 //------------------------------CompareAndSwapNNode---------------------------
669 class CompareAndSwapNNode : public LoadStoreNode {
670 public:
671 CompareAndSwapNNode( Node *c, Node *mem, Node *adr, Node *val, Node *ex) : LoadStoreNode(c, mem, adr, val, ex) { }
672 virtual int Opcode() const;
673 };
675 //------------------------------ClearArray-------------------------------------
676 class ClearArrayNode: public Node {
677 public:
678 ClearArrayNode( Node *ctrl, Node *arymem, Node *word_cnt, Node *base ) : Node(ctrl,arymem,word_cnt,base) {}
679 virtual int Opcode() const;
680 virtual const Type *bottom_type() const { return Type::MEMORY; }
681 // ClearArray modifies array elements, and so affects only the
682 // array memory addressed by the bottom_type of its base address.
683 virtual const class TypePtr *adr_type() const;
684 virtual Node *Identity( PhaseTransform *phase );
685 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
686 virtual uint match_edge(uint idx) const;
688 // Clear the given area of an object or array.
689 // The start offset must always be aligned mod BytesPerInt.
690 // The end offset must always be aligned mod BytesPerLong.
691 // Return the new memory.
692 static Node* clear_memory(Node* control, Node* mem, Node* dest,
693 intptr_t start_offset,
694 intptr_t end_offset,
695 PhaseGVN* phase);
696 static Node* clear_memory(Node* control, Node* mem, Node* dest,
697 intptr_t start_offset,
698 Node* end_offset,
699 PhaseGVN* phase);
700 static Node* clear_memory(Node* control, Node* mem, Node* dest,
701 Node* start_offset,
702 Node* end_offset,
703 PhaseGVN* phase);
704 };
706 //------------------------------StrComp-------------------------------------
707 class StrCompNode: public Node {
708 public:
709 StrCompNode(Node *control,
710 Node* char_array_mem,
711 Node* value_mem,
712 Node* count_mem,
713 Node* offset_mem,
714 Node* s1, Node* s2): Node(control,
715 char_array_mem,
716 value_mem,
717 count_mem,
718 offset_mem,
719 s1, s2) {};
720 virtual int Opcode() const;
721 virtual bool depends_only_on_test() const { return false; }
722 virtual const Type* bottom_type() const { return TypeInt::INT; }
723 // a StrCompNode (conservatively) aliases with everything:
724 virtual const TypePtr* adr_type() const { return TypePtr::BOTTOM; }
725 virtual uint match_edge(uint idx) const;
726 virtual uint ideal_reg() const { return Op_RegI; }
727 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
728 };
730 //------------------------------AryEq---------------------------------------
731 class AryEqNode: public Node {
732 public:
733 AryEqNode(Node *control, Node* s1, Node* s2): Node(control, s1, s2) {};
734 virtual int Opcode() const;
735 virtual bool depends_only_on_test() const { return false; }
736 virtual const Type* bottom_type() const { return TypeInt::BOOL; }
737 virtual const TypePtr* adr_type() const { return TypeAryPtr::CHARS; }
738 virtual uint ideal_reg() const { return Op_RegI; }
739 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
740 };
742 //------------------------------MemBar-----------------------------------------
743 // There are different flavors of Memory Barriers to match the Java Memory
744 // Model. Monitor-enter and volatile-load act as Aquires: no following ref
745 // can be moved to before them. We insert a MemBar-Acquire after a FastLock or
746 // volatile-load. Monitor-exit and volatile-store act as Release: no
747 // preceeding ref can be moved to after them. We insert a MemBar-Release
748 // before a FastUnlock or volatile-store. All volatiles need to be
749 // serialized, so we follow all volatile-stores with a MemBar-Volatile to
750 // seperate it from any following volatile-load.
751 class MemBarNode: public MultiNode {
752 virtual uint hash() const ; // { return NO_HASH; }
753 virtual uint cmp( const Node &n ) const ; // Always fail, except on self
755 virtual uint size_of() const { return sizeof(*this); }
756 // Memory type this node is serializing. Usually either rawptr or bottom.
757 const TypePtr* _adr_type;
759 public:
760 enum {
761 Precedent = TypeFunc::Parms // optional edge to force precedence
762 };
763 MemBarNode(Compile* C, int alias_idx, Node* precedent);
764 virtual int Opcode() const = 0;
765 virtual const class TypePtr *adr_type() const { return _adr_type; }
766 virtual const Type *Value( PhaseTransform *phase ) const;
767 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
768 virtual uint match_edge(uint idx) const { return 0; }
769 virtual const Type *bottom_type() const { return TypeTuple::MEMBAR; }
770 virtual Node *match( const ProjNode *proj, const Matcher *m );
771 // Factory method. Builds a wide or narrow membar.
772 // Optional 'precedent' becomes an extra edge if not null.
773 static MemBarNode* make(Compile* C, int opcode,
774 int alias_idx = Compile::AliasIdxBot,
775 Node* precedent = NULL);
776 };
778 // "Acquire" - no following ref can move before (but earlier refs can
779 // follow, like an early Load stalled in cache). Requires multi-cpu
780 // visibility. Inserted after a volatile load or FastLock.
781 class MemBarAcquireNode: public MemBarNode {
782 public:
783 MemBarAcquireNode(Compile* C, int alias_idx, Node* precedent)
784 : MemBarNode(C, alias_idx, precedent) {}
785 virtual int Opcode() const;
786 };
788 // "Release" - no earlier ref can move after (but later refs can move
789 // up, like a speculative pipelined cache-hitting Load). Requires
790 // multi-cpu visibility. Inserted before a volatile store or FastUnLock.
791 class MemBarReleaseNode: public MemBarNode {
792 public:
793 MemBarReleaseNode(Compile* C, int alias_idx, Node* precedent)
794 : MemBarNode(C, alias_idx, precedent) {}
795 virtual int Opcode() const;
796 };
798 // Ordering between a volatile store and a following volatile load.
799 // Requires multi-CPU visibility?
800 class MemBarVolatileNode: public MemBarNode {
801 public:
802 MemBarVolatileNode(Compile* C, int alias_idx, Node* precedent)
803 : MemBarNode(C, alias_idx, precedent) {}
804 virtual int Opcode() const;
805 };
807 // Ordering within the same CPU. Used to order unsafe memory references
808 // inside the compiler when we lack alias info. Not needed "outside" the
809 // compiler because the CPU does all the ordering for us.
810 class MemBarCPUOrderNode: public MemBarNode {
811 public:
812 MemBarCPUOrderNode(Compile* C, int alias_idx, Node* precedent)
813 : MemBarNode(C, alias_idx, precedent) {}
814 virtual int Opcode() const;
815 virtual uint ideal_reg() const { return 0; } // not matched in the AD file
816 };
818 // Isolation of object setup after an AllocateNode and before next safepoint.
819 // (See comment in memnode.cpp near InitializeNode::InitializeNode for semantics.)
820 class InitializeNode: public MemBarNode {
821 friend class AllocateNode;
823 bool _is_complete;
825 public:
826 enum {
827 Control = TypeFunc::Control,
828 Memory = TypeFunc::Memory, // MergeMem for states affected by this op
829 RawAddress = TypeFunc::Parms+0, // the newly-allocated raw address
830 RawStores = TypeFunc::Parms+1 // zero or more stores (or TOP)
831 };
833 InitializeNode(Compile* C, int adr_type, Node* rawoop);
834 virtual int Opcode() const;
835 virtual uint size_of() const { return sizeof(*this); }
836 virtual uint ideal_reg() const { return 0; } // not matched in the AD file
837 virtual const RegMask &in_RegMask(uint) const; // mask for RawAddress
839 // Manage incoming memory edges via a MergeMem on in(Memory):
840 Node* memory(uint alias_idx);
842 // The raw memory edge coming directly from the Allocation.
843 // The contents of this memory are *always* all-zero-bits.
844 Node* zero_memory() { return memory(Compile::AliasIdxRaw); }
846 // Return the corresponding allocation for this initialization (or null if none).
847 // (Note: Both InitializeNode::allocation and AllocateNode::initialization
848 // are defined in graphKit.cpp, which sets up the bidirectional relation.)
849 AllocateNode* allocation();
851 // Anything other than zeroing in this init?
852 bool is_non_zero();
854 // An InitializeNode must completed before macro expansion is done.
855 // Completion requires that the AllocateNode must be followed by
856 // initialization of the new memory to zero, then to any initializers.
857 bool is_complete() { return _is_complete; }
859 // Mark complete. (Must not yet be complete.)
860 void set_complete(PhaseGVN* phase);
862 #ifdef ASSERT
863 // ensure all non-degenerate stores are ordered and non-overlapping
864 bool stores_are_sane(PhaseTransform* phase);
865 #endif //ASSERT
867 // See if this store can be captured; return offset where it initializes.
868 // Return 0 if the store cannot be moved (any sort of problem).
869 intptr_t can_capture_store(StoreNode* st, PhaseTransform* phase);
871 // Capture another store; reformat it to write my internal raw memory.
872 // Return the captured copy, else NULL if there is some sort of problem.
873 Node* capture_store(StoreNode* st, intptr_t start, PhaseTransform* phase);
875 // Find captured store which corresponds to the range [start..start+size).
876 // Return my own memory projection (meaning the initial zero bits)
877 // if there is no such store. Return NULL if there is a problem.
878 Node* find_captured_store(intptr_t start, int size_in_bytes, PhaseTransform* phase);
880 // Called when the associated AllocateNode is expanded into CFG.
881 Node* complete_stores(Node* rawctl, Node* rawmem, Node* rawptr,
882 intptr_t header_size, Node* size_in_bytes,
883 PhaseGVN* phase);
885 private:
886 void remove_extra_zeroes();
888 // Find out where a captured store should be placed (or already is placed).
889 int captured_store_insertion_point(intptr_t start, int size_in_bytes,
890 PhaseTransform* phase);
892 static intptr_t get_store_offset(Node* st, PhaseTransform* phase);
894 Node* make_raw_address(intptr_t offset, PhaseTransform* phase);
896 bool detect_init_independence(Node* n, bool st_is_pinned, int& count);
898 void coalesce_subword_stores(intptr_t header_size, Node* size_in_bytes,
899 PhaseGVN* phase);
901 intptr_t find_next_fullword_store(uint i, PhaseGVN* phase);
902 };
904 //------------------------------MergeMem---------------------------------------
905 // (See comment in memnode.cpp near MergeMemNode::MergeMemNode for semantics.)
906 class MergeMemNode: public Node {
907 virtual uint hash() const ; // { return NO_HASH; }
908 virtual uint cmp( const Node &n ) const ; // Always fail, except on self
909 friend class MergeMemStream;
910 MergeMemNode(Node* def); // clients use MergeMemNode::make
912 public:
913 // If the input is a whole memory state, clone it with all its slices intact.
914 // Otherwise, make a new memory state with just that base memory input.
915 // In either case, the result is a newly created MergeMem.
916 static MergeMemNode* make(Compile* C, Node* base_memory);
918 virtual int Opcode() const;
919 virtual Node *Identity( PhaseTransform *phase );
920 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
921 virtual uint ideal_reg() const { return NotAMachineReg; }
922 virtual uint match_edge(uint idx) const { return 0; }
923 virtual const RegMask &out_RegMask() const;
924 virtual const Type *bottom_type() const { return Type::MEMORY; }
925 virtual const TypePtr *adr_type() const { return TypePtr::BOTTOM; }
926 // sparse accessors
927 // Fetch the previously stored "set_memory_at", or else the base memory.
928 // (Caller should clone it if it is a phi-nest.)
929 Node* memory_at(uint alias_idx) const;
930 // set the memory, regardless of its previous value
931 void set_memory_at(uint alias_idx, Node* n);
932 // the "base" is the memory that provides the non-finite support
933 Node* base_memory() const { return in(Compile::AliasIdxBot); }
934 // warning: setting the base can implicitly set any of the other slices too
935 void set_base_memory(Node* def);
936 // sentinel value which denotes a copy of the base memory:
937 Node* empty_memory() const { return in(Compile::AliasIdxTop); }
938 static Node* make_empty_memory(); // where the sentinel comes from
939 bool is_empty_memory(Node* n) const { assert((n == empty_memory()) == n->is_top(), "sanity"); return n->is_top(); }
940 // hook for the iterator, to perform any necessary setup
941 void iteration_setup(const MergeMemNode* other = NULL);
942 // push sentinels until I am at least as long as the other (semantic no-op)
943 void grow_to_match(const MergeMemNode* other);
944 bool verify_sparse() const PRODUCT_RETURN0;
945 #ifndef PRODUCT
946 virtual void dump_spec(outputStream *st) const;
947 #endif
948 };
950 class MergeMemStream : public StackObj {
951 private:
952 MergeMemNode* _mm;
953 const MergeMemNode* _mm2; // optional second guy, contributes non-empty iterations
954 Node* _mm_base; // loop-invariant base memory of _mm
955 int _idx;
956 int _cnt;
957 Node* _mem;
958 Node* _mem2;
959 int _cnt2;
961 void init(MergeMemNode* mm, const MergeMemNode* mm2 = NULL) {
962 // subsume_node will break sparseness at times, whenever a memory slice
963 // folds down to a copy of the base ("fat") memory. In such a case,
964 // the raw edge will update to base, although it should be top.
965 // This iterator will recognize either top or base_memory as an
966 // "empty" slice. See is_empty, is_empty2, and next below.
967 //
968 // The sparseness property is repaired in MergeMemNode::Ideal.
969 // As long as access to a MergeMem goes through this iterator
970 // or the memory_at accessor, flaws in the sparseness will
971 // never be observed.
972 //
973 // Also, iteration_setup repairs sparseness.
974 assert(mm->verify_sparse(), "please, no dups of base");
975 assert(mm2==NULL || mm2->verify_sparse(), "please, no dups of base");
977 _mm = mm;
978 _mm_base = mm->base_memory();
979 _mm2 = mm2;
980 _cnt = mm->req();
981 _idx = Compile::AliasIdxBot-1; // start at the base memory
982 _mem = NULL;
983 _mem2 = NULL;
984 }
986 #ifdef ASSERT
987 Node* check_memory() const {
988 if (at_base_memory())
989 return _mm->base_memory();
990 else if ((uint)_idx < _mm->req() && !_mm->in(_idx)->is_top())
991 return _mm->memory_at(_idx);
992 else
993 return _mm_base;
994 }
995 Node* check_memory2() const {
996 return at_base_memory()? _mm2->base_memory(): _mm2->memory_at(_idx);
997 }
998 #endif
1000 static bool match_memory(Node* mem, const MergeMemNode* mm, int idx) PRODUCT_RETURN0;
1001 void assert_synch() const {
1002 assert(!_mem || _idx >= _cnt || match_memory(_mem, _mm, _idx),
1003 "no side-effects except through the stream");
1004 }
1006 public:
1008 // expected usages:
1009 // for (MergeMemStream mms(mem->is_MergeMem()); next_non_empty(); ) { ... }
1010 // for (MergeMemStream mms(mem1, mem2); next_non_empty2(); ) { ... }
1012 // iterate over one merge
1013 MergeMemStream(MergeMemNode* mm) {
1014 mm->iteration_setup();
1015 init(mm);
1016 debug_only(_cnt2 = 999);
1017 }
1018 // iterate in parallel over two merges
1019 // only iterates through non-empty elements of mm2
1020 MergeMemStream(MergeMemNode* mm, const MergeMemNode* mm2) {
1021 assert(mm2, "second argument must be a MergeMem also");
1022 ((MergeMemNode*)mm2)->iteration_setup(); // update hidden state
1023 mm->iteration_setup(mm2);
1024 init(mm, mm2);
1025 _cnt2 = mm2->req();
1026 }
1027 #ifdef ASSERT
1028 ~MergeMemStream() {
1029 assert_synch();
1030 }
1031 #endif
1033 MergeMemNode* all_memory() const {
1034 return _mm;
1035 }
1036 Node* base_memory() const {
1037 assert(_mm_base == _mm->base_memory(), "no update to base memory, please");
1038 return _mm_base;
1039 }
1040 const MergeMemNode* all_memory2() const {
1041 assert(_mm2 != NULL, "");
1042 return _mm2;
1043 }
1044 bool at_base_memory() const {
1045 return _idx == Compile::AliasIdxBot;
1046 }
1047 int alias_idx() const {
1048 assert(_mem, "must call next 1st");
1049 return _idx;
1050 }
1052 const TypePtr* adr_type() const {
1053 return Compile::current()->get_adr_type(alias_idx());
1054 }
1056 const TypePtr* adr_type(Compile* C) const {
1057 return C->get_adr_type(alias_idx());
1058 }
1059 bool is_empty() const {
1060 assert(_mem, "must call next 1st");
1061 assert(_mem->is_top() == (_mem==_mm->empty_memory()), "correct sentinel");
1062 return _mem->is_top();
1063 }
1064 bool is_empty2() const {
1065 assert(_mem2, "must call next 1st");
1066 assert(_mem2->is_top() == (_mem2==_mm2->empty_memory()), "correct sentinel");
1067 return _mem2->is_top();
1068 }
1069 Node* memory() const {
1070 assert(!is_empty(), "must not be empty");
1071 assert_synch();
1072 return _mem;
1073 }
1074 // get the current memory, regardless of empty or non-empty status
1075 Node* force_memory() const {
1076 assert(!is_empty() || !at_base_memory(), "");
1077 // Use _mm_base to defend against updates to _mem->base_memory().
1078 Node *mem = _mem->is_top() ? _mm_base : _mem;
1079 assert(mem == check_memory(), "");
1080 return mem;
1081 }
1082 Node* memory2() const {
1083 assert(_mem2 == check_memory2(), "");
1084 return _mem2;
1085 }
1086 void set_memory(Node* mem) {
1087 if (at_base_memory()) {
1088 // Note that this does not change the invariant _mm_base.
1089 _mm->set_base_memory(mem);
1090 } else {
1091 _mm->set_memory_at(_idx, mem);
1092 }
1093 _mem = mem;
1094 assert_synch();
1095 }
1097 // Recover from a side effect to the MergeMemNode.
1098 void set_memory() {
1099 _mem = _mm->in(_idx);
1100 }
1102 bool next() { return next(false); }
1103 bool next2() { return next(true); }
1105 bool next_non_empty() { return next_non_empty(false); }
1106 bool next_non_empty2() { return next_non_empty(true); }
1107 // next_non_empty2 can yield states where is_empty() is true
1109 private:
1110 // find the next item, which might be empty
1111 bool next(bool have_mm2) {
1112 assert((_mm2 != NULL) == have_mm2, "use other next");
1113 assert_synch();
1114 if (++_idx < _cnt) {
1115 // Note: This iterator allows _mm to be non-sparse.
1116 // It behaves the same whether _mem is top or base_memory.
1117 _mem = _mm->in(_idx);
1118 if (have_mm2)
1119 _mem2 = _mm2->in((_idx < _cnt2) ? _idx : Compile::AliasIdxTop);
1120 return true;
1121 }
1122 return false;
1123 }
1125 // find the next non-empty item
1126 bool next_non_empty(bool have_mm2) {
1127 while (next(have_mm2)) {
1128 if (!is_empty()) {
1129 // make sure _mem2 is filled in sensibly
1130 if (have_mm2 && _mem2->is_top()) _mem2 = _mm2->base_memory();
1131 return true;
1132 } else if (have_mm2 && !is_empty2()) {
1133 return true; // is_empty() == true
1134 }
1135 }
1136 return false;
1137 }
1138 };
1140 //------------------------------Prefetch---------------------------------------
1142 // Non-faulting prefetch load. Prefetch for many reads.
1143 class PrefetchReadNode : public Node {
1144 public:
1145 PrefetchReadNode(Node *abio, Node *adr) : Node(0,abio,adr) {}
1146 virtual int Opcode() const;
1147 virtual uint ideal_reg() const { return NotAMachineReg; }
1148 virtual uint match_edge(uint idx) const { return idx==2; }
1149 virtual const Type *bottom_type() const { return Type::ABIO; }
1150 };
1152 // Non-faulting prefetch load. Prefetch for many reads & many writes.
1153 class PrefetchWriteNode : public Node {
1154 public:
1155 PrefetchWriteNode(Node *abio, Node *adr) : Node(0,abio,adr) {}
1156 virtual int Opcode() const;
1157 virtual uint ideal_reg() const { return NotAMachineReg; }
1158 virtual uint match_edge(uint idx) const { return idx==2; }
1159 virtual const Type *bottom_type() const { return Type::ABIO; }
1160 };