1 /*
2 * Copyright (c) 1997, 2015, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
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7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
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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).
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23 */
24
25 #ifndef SHARE_VM_OPTO_MEMNODE_HPP
26 #define SHARE_VM_OPTO_MEMNODE_HPP
27
28 #include "opto/multnode.hpp"
29 #include "opto/node.hpp"
30 #include "opto/opcodes.hpp"
31 #include "opto/type.hpp"
32
33 // Portions of code courtesy of Clifford Click
34
35 class MultiNode;
36 class PhaseCCP;
37 class PhaseTransform;
38
39 //------------------------------MemNode----------------------------------------
40 // Load or Store, possibly throwing a NULL pointer exception
41 class MemNode : public Node {
42 private:
43 bool _unaligned_access; // Unaligned access from unsafe
44 bool _mismatched_access; // Mismatched access from unsafe: byte read in integer array for instance
45 protected:
46 #ifdef ASSERT
47 const TypePtr* _adr_type; // What kind of memory is being addressed?
48 #endif
49 virtual uint size_of() const;
50 public:
51 enum { Control, // When is it safe to do this load?
52 Memory, // Chunk of memory is being loaded from
53 Address, // Actually address, derived from base
54 ValueIn, // Value to store
55 OopStore // Preceeding oop store, only in StoreCM
56 };
57 typedef enum { unordered = 0,
58 acquire, // Load has to acquire or be succeeded by MemBarAcquire.
59 release, // Store has to release or be preceded by MemBarRelease.
60 seqcst, // LoadStore has to have both acquire and release semantics.
61 unset // The memory ordering is not set (used for testing)
62 } MemOrd;
63 protected:
64 MemNode( Node *c0, Node *c1, Node *c2, const TypePtr* at )
65 : Node(c0,c1,c2 ), _unaligned_access(false), _mismatched_access(false) {
66 init_class_id(Class_Mem);
67 debug_only(_adr_type=at; adr_type();)
68 }
69 MemNode( Node *c0, Node *c1, Node *c2, const TypePtr* at, Node *c3 )
70 : Node(c0,c1,c2,c3), _unaligned_access(false), _mismatched_access(false) {
71 init_class_id(Class_Mem);
72 debug_only(_adr_type=at; adr_type();)
73 }
74 MemNode( Node *c0, Node *c1, Node *c2, const TypePtr* at, Node *c3, Node *c4)
75 : Node(c0,c1,c2,c3,c4), _unaligned_access(false), _mismatched_access(false) {
76 init_class_id(Class_Mem);
77 debug_only(_adr_type=at; adr_type();)
78 }
79
80 virtual Node* find_previous_arraycopy(PhaseTransform* phase, Node* ld_alloc, Node*& mem, bool can_see_stored_value) const { return NULL; }
81 static bool check_if_adr_maybe_raw(Node* adr);
82
83 public:
84 // Helpers for the optimizer. Documented in memnode.cpp.
85 static bool detect_ptr_independence(Node* p1, AllocateNode* a1,
86 Node* p2, AllocateNode* a2,
87 PhaseTransform* phase);
88 static bool adr_phi_is_loop_invariant(Node* adr_phi, Node* cast);
89
90 static Node *optimize_simple_memory_chain(Node *mchain, const TypeOopPtr *t_oop, Node *load, PhaseGVN *phase);
91 static Node *optimize_memory_chain(Node *mchain, const TypePtr *t_adr, Node *load, PhaseGVN *phase);
92 // This one should probably be a phase-specific function:
93 static bool all_controls_dominate(Node* dom, Node* sub);
94
95 virtual const class TypePtr *adr_type() const; // returns bottom_type of address
96
97 // Shared code for Ideal methods:
98 Node *Ideal_common(PhaseGVN *phase, bool can_reshape); // Return -1 for short-circuit NULL.
99
100 // Helper function for adr_type() implementations.
101 static const TypePtr* calculate_adr_type(const Type* t, const TypePtr* cross_check = NULL);
102
103 // Raw access function, to allow copying of adr_type efficiently in
104 // product builds and retain the debug info for debug builds.
105 const TypePtr *raw_adr_type() const {
106 #ifdef ASSERT
107 return _adr_type;
108 #else
109 return 0;
110 #endif
111 }
112
113 // Map a load or store opcode to its corresponding store opcode.
114 // (Return -1 if unknown.)
115 virtual int store_Opcode() const { return -1; }
116
117 // What is the type of the value in memory? (T_VOID mean "unspecified".)
118 virtual BasicType memory_type() const = 0;
119 virtual int memory_size() const {
120 #ifdef ASSERT
121 return type2aelembytes(memory_type(), true);
122 #else
123 return type2aelembytes(memory_type());
124 #endif
125 }
126
127 // Search through memory states which precede this node (load or store).
128 // Look for an exact match for the address, with no intervening
129 // aliased stores.
130 Node* find_previous_store(PhaseTransform* phase);
131
132 // Can this node (load or store) accurately see a stored value in
133 // the given memory state? (The state may or may not be in(Memory).)
134 Node* can_see_stored_value(Node* st, PhaseTransform* phase) const;
135
136 void set_unaligned_access() { _unaligned_access = true; }
137 bool is_unaligned_access() const { return _unaligned_access; }
138 void set_mismatched_access() { _mismatched_access = true; }
139 bool is_mismatched_access() const { return _mismatched_access; }
140
141 #ifndef PRODUCT
142 static void dump_adr_type(const Node* mem, const TypePtr* adr_type, outputStream *st);
143 virtual void dump_spec(outputStream *st) const;
144 #endif
145 };
146
147 //------------------------------LoadNode---------------------------------------
148 // Load value; requires Memory and Address
149 class LoadNode : public MemNode {
150 public:
151 // Some loads (from unsafe) should be pinned: they don't depend only
152 // on the dominating test. The field _control_dependency below records
153 // whether that node depends only on the dominating test.
154 // Methods used to build LoadNodes pass an argument of type enum
155 // ControlDependency instead of a boolean because those methods
156 // typically have multiple boolean parameters with default values:
157 // passing the wrong boolean to one of these parameters by mistake
158 // goes easily unnoticed. Using an enum, the compiler can check that
159 // the type of a value and the type of the parameter match.
160 enum ControlDependency {
161 Pinned,
162 DependsOnlyOnTest
163 };
164 private:
165 // LoadNode::hash() doesn't take the _control_dependency field
166 // into account: If the graph already has a non-pinned LoadNode and
167 // we add a pinned LoadNode with the same inputs, it's safe for GVN
168 // to replace the pinned LoadNode with the non-pinned LoadNode,
169 // otherwise it wouldn't be safe to have a non pinned LoadNode with
170 // those inputs in the first place. If the graph already has a
171 // pinned LoadNode and we add a non pinned LoadNode with the same
172 // inputs, it's safe (but suboptimal) for GVN to replace the
173 // non-pinned LoadNode by the pinned LoadNode.
174 ControlDependency _control_dependency;
175
176 // On platforms with weak memory ordering (e.g., PPC, Ia64) we distinguish
177 // loads that can be reordered, and such requiring acquire semantics to
178 // adhere to the Java specification. The required behaviour is stored in
179 // this field.
180 const MemOrd _mo;
181
182 protected:
183 virtual uint cmp(const Node &n) const;
184 virtual uint size_of() const; // Size is bigger
185 // Should LoadNode::Ideal() attempt to remove control edges?
186 virtual bool can_remove_control() const;
187 const Type* const _type; // What kind of value is loaded?
188
189 virtual Node* find_previous_arraycopy(PhaseTransform* phase, Node* ld_alloc, Node*& mem, bool can_see_stored_value) const;
190 public:
191
192 LoadNode(Node *c, Node *mem, Node *adr, const TypePtr* at, const Type *rt, MemOrd mo, ControlDependency control_dependency)
193 : MemNode(c,mem,adr,at), _type(rt), _mo(mo), _control_dependency(control_dependency) {
194 init_class_id(Class_Load);
195 }
196 inline bool is_unordered() const { return !is_acquire(); }
197 inline bool is_acquire() const {
198 assert(_mo == unordered || _mo == acquire, "unexpected");
199 return _mo == acquire;
200 }
201 inline bool is_unsigned() const {
202 int lop = Opcode();
203 return (lop == Op_LoadUB) || (lop == Op_LoadUS);
204 }
205
206 // Polymorphic factory method:
207 static Node* make(PhaseGVN& gvn, Node *c, Node *mem, Node *adr,
208 const TypePtr* at, const Type *rt, BasicType bt,
209 MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest,
210 bool unaligned = false, bool mismatched = false);
211
212 virtual uint hash() const; // Check the type
213
214 // Handle algebraic identities here. If we have an identity, return the Node
215 // we are equivalent to. We look for Load of a Store.
216 virtual Node* Identity(PhaseGVN* phase);
217
218 // If the load is from Field memory and the pointer is non-null, it might be possible to
219 // zero out the control input.
220 // If the offset is constant and the base is an object allocation,
221 // try to hook me up to the exact initializing store.
222 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
223
224 // Split instance field load through Phi.
225 Node* split_through_phi(PhaseGVN *phase);
226
227 // Recover original value from boxed values
228 Node *eliminate_autobox(PhaseGVN *phase);
229
230 // Compute a new Type for this node. Basically we just do the pre-check,
231 // then call the virtual add() to set the type.
232 virtual const Type* Value(PhaseGVN* phase) const;
233
234 // Common methods for LoadKlass and LoadNKlass nodes.
235 const Type* klass_value_common(PhaseGVN* phase) const;
236 Node* klass_identity_common(PhaseGVN* phase);
237
238 virtual uint ideal_reg() const;
239 virtual const Type *bottom_type() const;
240 // Following method is copied from TypeNode:
241 void set_type(const Type* t) {
242 assert(t != NULL, "sanity");
243 debug_only(uint check_hash = (VerifyHashTableKeys && _hash_lock) ? hash() : NO_HASH);
244 *(const Type**)&_type = t; // cast away const-ness
245 // If this node is in the hash table, make sure it doesn't need a rehash.
246 assert(check_hash == NO_HASH || check_hash == hash(), "type change must preserve hash code");
247 }
248 const Type* type() const { assert(_type != NULL, "sanity"); return _type; };
249
250 // Do not match memory edge
251 virtual uint match_edge(uint idx) const;
252
253 // Map a load opcode to its corresponding store opcode.
254 virtual int store_Opcode() const = 0;
255
256 // Check if the load's memory input is a Phi node with the same control.
257 bool is_instance_field_load_with_local_phi(Node* ctrl);
258
259 Node* convert_to_unsigned_load(PhaseGVN& gvn);
260 Node* convert_to_signed_load(PhaseGVN& gvn);
261
262 #ifndef PRODUCT
263 virtual void dump_spec(outputStream *st) const;
264 #endif
265 #ifdef ASSERT
266 // Helper function to allow a raw load without control edge for some cases
267 static bool is_immutable_value(Node* adr);
268 #endif
269 protected:
270 const Type* load_array_final_field(const TypeKlassPtr *tkls,
271 ciKlass* klass) const;
272
273 Node* can_see_arraycopy_value(Node* st, PhaseTransform* phase) const;
274
275 // depends_only_on_test is almost always true, and needs to be almost always
276 // true to enable key hoisting & commoning optimizations. However, for the
277 // special case of RawPtr loads from TLS top & end, and other loads performed by
278 // GC barriers, the control edge carries the dependence preventing hoisting past
279 // a Safepoint instead of the memory edge. (An unfortunate consequence of having
280 // Safepoints not set Raw Memory; itself an unfortunate consequence of having Nodes
281 // which produce results (new raw memory state) inside of loops preventing all
282 // manner of other optimizations). Basically, it's ugly but so is the alternative.
283 // See comment in macro.cpp, around line 125 expand_allocate_common().
284 virtual bool depends_only_on_test() const {
285 return adr_type() != TypeRawPtr::BOTTOM && _control_dependency == DependsOnlyOnTest;
286 }
287 };
288
289 //------------------------------LoadBNode--------------------------------------
290 // Load a byte (8bits signed) from memory
291 class LoadBNode : public LoadNode {
292 public:
293 LoadBNode(Node *c, Node *mem, Node *adr, const TypePtr* at, const TypeInt *ti, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
294 : LoadNode(c, mem, adr, at, ti, mo, control_dependency) {}
295 virtual int Opcode() const;
296 virtual uint ideal_reg() const { return Op_RegI; }
297 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
298 virtual const Type* Value(PhaseGVN* phase) const;
299 virtual int store_Opcode() const { return Op_StoreB; }
300 virtual BasicType memory_type() const { return T_BYTE; }
301 };
302
303 //------------------------------LoadUBNode-------------------------------------
304 // Load a unsigned byte (8bits unsigned) from memory
305 class LoadUBNode : public LoadNode {
306 public:
307 LoadUBNode(Node* c, Node* mem, Node* adr, const TypePtr* at, const TypeInt* ti, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
308 : LoadNode(c, mem, adr, at, ti, mo, control_dependency) {}
309 virtual int Opcode() const;
310 virtual uint ideal_reg() const { return Op_RegI; }
311 virtual Node* Ideal(PhaseGVN *phase, bool can_reshape);
312 virtual const Type* Value(PhaseGVN* phase) const;
313 virtual int store_Opcode() const { return Op_StoreB; }
314 virtual BasicType memory_type() const { return T_BYTE; }
315 };
316
317 //------------------------------LoadUSNode-------------------------------------
318 // Load an unsigned short/char (16bits unsigned) from memory
319 class LoadUSNode : public LoadNode {
320 public:
321 LoadUSNode(Node *c, Node *mem, Node *adr, const TypePtr* at, const TypeInt *ti, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
322 : LoadNode(c, mem, adr, at, ti, mo, control_dependency) {}
323 virtual int Opcode() const;
324 virtual uint ideal_reg() const { return Op_RegI; }
325 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
326 virtual const Type* Value(PhaseGVN* phase) const;
327 virtual int store_Opcode() const { return Op_StoreC; }
328 virtual BasicType memory_type() const { return T_CHAR; }
329 };
330
331 //------------------------------LoadSNode--------------------------------------
332 // Load a short (16bits signed) from memory
333 class LoadSNode : public LoadNode {
334 public:
335 LoadSNode(Node *c, Node *mem, Node *adr, const TypePtr* at, const TypeInt *ti, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
336 : LoadNode(c, mem, adr, at, ti, mo, control_dependency) {}
337 virtual int Opcode() const;
338 virtual uint ideal_reg() const { return Op_RegI; }
339 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
340 virtual const Type* Value(PhaseGVN* phase) const;
341 virtual int store_Opcode() const { return Op_StoreC; }
342 virtual BasicType memory_type() const { return T_SHORT; }
343 };
344
345 //------------------------------LoadINode--------------------------------------
346 // Load an integer from memory
347 class LoadINode : public LoadNode {
348 public:
349 LoadINode(Node *c, Node *mem, Node *adr, const TypePtr* at, const TypeInt *ti, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
350 : LoadNode(c, mem, adr, at, ti, mo, control_dependency) {}
351 virtual int Opcode() const;
352 virtual uint ideal_reg() const { return Op_RegI; }
353 virtual int store_Opcode() const { return Op_StoreI; }
354 virtual BasicType memory_type() const { return T_INT; }
355 };
356
357 //------------------------------LoadRangeNode----------------------------------
358 // Load an array length from the array
359 class LoadRangeNode : public LoadINode {
360 public:
361 LoadRangeNode(Node *c, Node *mem, Node *adr, const TypeInt *ti = TypeInt::POS)
362 : LoadINode(c, mem, adr, TypeAryPtr::RANGE, ti, MemNode::unordered) {}
363 virtual int Opcode() const;
364 virtual const Type* Value(PhaseGVN* phase) const;
365 virtual Node* Identity(PhaseGVN* phase);
366 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
367 };
368
369 //------------------------------LoadLNode--------------------------------------
370 // Load a long from memory
371 class LoadLNode : public LoadNode {
372 virtual uint hash() const { return LoadNode::hash() + _require_atomic_access; }
373 virtual uint cmp( const Node &n ) const {
374 return _require_atomic_access == ((LoadLNode&)n)._require_atomic_access
375 && LoadNode::cmp(n);
376 }
377 virtual uint size_of() const { return sizeof(*this); }
378 const bool _require_atomic_access; // is piecewise load forbidden?
379
380 public:
381 LoadLNode(Node *c, Node *mem, Node *adr, const TypePtr* at, const TypeLong *tl,
382 MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest, bool require_atomic_access = false)
383 : LoadNode(c, mem, adr, at, tl, mo, control_dependency), _require_atomic_access(require_atomic_access) {}
384 virtual int Opcode() const;
385 virtual uint ideal_reg() const { return Op_RegL; }
386 virtual int store_Opcode() const { return Op_StoreL; }
387 virtual BasicType memory_type() const { return T_LONG; }
388 bool require_atomic_access() const { return _require_atomic_access; }
389 static LoadLNode* make_atomic(Node* ctl, Node* mem, Node* adr, const TypePtr* adr_type,
390 const Type* rt, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest,
391 bool unaligned = false, bool mismatched = false);
392 #ifndef PRODUCT
393 virtual void dump_spec(outputStream *st) const {
394 LoadNode::dump_spec(st);
395 if (_require_atomic_access) st->print(" Atomic!");
396 }
397 #endif
398 };
399
400 //------------------------------LoadL_unalignedNode----------------------------
401 // Load a long from unaligned memory
402 class LoadL_unalignedNode : public LoadLNode {
403 public:
404 LoadL_unalignedNode(Node *c, Node *mem, Node *adr, const TypePtr* at, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
405 : LoadLNode(c, mem, adr, at, TypeLong::LONG, mo, control_dependency) {}
406 virtual int Opcode() const;
407 };
408
409 //------------------------------LoadFNode--------------------------------------
410 // Load a float (64 bits) from memory
411 class LoadFNode : public LoadNode {
412 public:
413 LoadFNode(Node *c, Node *mem, Node *adr, const TypePtr* at, const Type *t, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
414 : LoadNode(c, mem, adr, at, t, mo, control_dependency) {}
415 virtual int Opcode() const;
416 virtual uint ideal_reg() const { return Op_RegF; }
417 virtual int store_Opcode() const { return Op_StoreF; }
418 virtual BasicType memory_type() const { return T_FLOAT; }
419 };
420
421 //------------------------------LoadDNode--------------------------------------
422 // Load a double (64 bits) from memory
423 class LoadDNode : public LoadNode {
424 virtual uint hash() const { return LoadNode::hash() + _require_atomic_access; }
425 virtual uint cmp( const Node &n ) const {
426 return _require_atomic_access == ((LoadDNode&)n)._require_atomic_access
427 && LoadNode::cmp(n);
428 }
429 virtual uint size_of() const { return sizeof(*this); }
430 const bool _require_atomic_access; // is piecewise load forbidden?
431
432 public:
433 LoadDNode(Node *c, Node *mem, Node *adr, const TypePtr* at, const Type *t,
434 MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest, bool require_atomic_access = false)
435 : LoadNode(c, mem, adr, at, t, mo, control_dependency), _require_atomic_access(require_atomic_access) {}
436 virtual int Opcode() const;
437 virtual uint ideal_reg() const { return Op_RegD; }
438 virtual int store_Opcode() const { return Op_StoreD; }
439 virtual BasicType memory_type() const { return T_DOUBLE; }
440 bool require_atomic_access() const { return _require_atomic_access; }
441 static LoadDNode* make_atomic(Node* ctl, Node* mem, Node* adr, const TypePtr* adr_type,
442 const Type* rt, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest,
443 bool unaligned = false, bool mismatched = false);
444 #ifndef PRODUCT
445 virtual void dump_spec(outputStream *st) const {
446 LoadNode::dump_spec(st);
447 if (_require_atomic_access) st->print(" Atomic!");
448 }
449 #endif
450 };
451
452 //------------------------------LoadD_unalignedNode----------------------------
453 // Load a double from unaligned memory
454 class LoadD_unalignedNode : public LoadDNode {
455 public:
456 LoadD_unalignedNode(Node *c, Node *mem, Node *adr, const TypePtr* at, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
457 : LoadDNode(c, mem, adr, at, Type::DOUBLE, mo, control_dependency) {}
458 virtual int Opcode() const;
459 };
460
461 //------------------------------LoadPNode--------------------------------------
462 // Load a pointer from memory (either object or array)
463 class LoadPNode : public LoadNode {
464 public:
465 LoadPNode(Node *c, Node *mem, Node *adr, const TypePtr *at, const TypePtr* t, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
466 : LoadNode(c, mem, adr, at, t, mo, control_dependency) {}
467 virtual int Opcode() const;
468 virtual uint ideal_reg() const { return Op_RegP; }
469 virtual int store_Opcode() const { return Op_StoreP; }
470 virtual BasicType memory_type() const { return T_ADDRESS; }
471 };
472
473
474 //------------------------------LoadNNode--------------------------------------
475 // Load a narrow oop from memory (either object or array)
476 class LoadNNode : public LoadNode {
477 public:
478 LoadNNode(Node *c, Node *mem, Node *adr, const TypePtr *at, const Type* t, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
479 : LoadNode(c, mem, adr, at, t, mo, control_dependency) {}
480 virtual int Opcode() const;
481 virtual uint ideal_reg() const { return Op_RegN; }
482 virtual int store_Opcode() const { return Op_StoreN; }
483 virtual BasicType memory_type() const { return T_NARROWOOP; }
484 };
485
486 //------------------------------LoadKlassNode----------------------------------
487 // Load a Klass from an object
488 class LoadKlassNode : public LoadPNode {
489 protected:
490 // In most cases, LoadKlassNode does not have the control input set. If the control
491 // input is set, it must not be removed (by LoadNode::Ideal()).
492 virtual bool can_remove_control() const;
493 public:
494 LoadKlassNode(Node *c, Node *mem, Node *adr, const TypePtr *at, const TypeKlassPtr *tk, MemOrd mo)
495 : LoadPNode(c, mem, adr, at, tk, mo) {}
496 virtual int Opcode() const;
497 virtual const Type* Value(PhaseGVN* phase) const;
498 virtual Node* Identity(PhaseGVN* phase);
499 virtual bool depends_only_on_test() const { return true; }
500
501 // Polymorphic factory method:
502 static Node* make(PhaseGVN& gvn, Node* ctl, Node* mem, Node* adr, const TypePtr* at,
503 const TypeKlassPtr* tk = TypeKlassPtr::OBJECT);
504 };
505
506 //------------------------------LoadNKlassNode---------------------------------
507 // Load a narrow Klass from an object.
508 class LoadNKlassNode : public LoadNNode {
509 public:
510 LoadNKlassNode(Node *c, Node *mem, Node *adr, const TypePtr *at, const TypeNarrowKlass *tk, MemOrd mo)
511 : LoadNNode(c, mem, adr, at, tk, mo) {}
512 virtual int Opcode() const;
513 virtual uint ideal_reg() const { return Op_RegN; }
514 virtual int store_Opcode() const { return Op_StoreNKlass; }
515 virtual BasicType memory_type() const { return T_NARROWKLASS; }
516
517 virtual const Type* Value(PhaseGVN* phase) const;
518 virtual Node* Identity(PhaseGVN* phase);
519 virtual bool depends_only_on_test() const { return true; }
520 };
521
522
523 //------------------------------StoreNode--------------------------------------
524 // Store value; requires Store, Address and Value
525 class StoreNode : public MemNode {
526 private:
527 // On platforms with weak memory ordering (e.g., PPC, Ia64) we distinguish
528 // stores that can be reordered, and such requiring release semantics to
529 // adhere to the Java specification. The required behaviour is stored in
530 // this field.
531 const MemOrd _mo;
532 // Needed for proper cloning.
533 virtual uint size_of() const { return sizeof(*this); }
534 protected:
535 virtual uint cmp( const Node &n ) const;
536 virtual bool depends_only_on_test() const { return false; }
537
538 Node *Ideal_masked_input (PhaseGVN *phase, uint mask);
539 Node *Ideal_sign_extended_input(PhaseGVN *phase, int num_bits);
540
541 public:
542 // We must ensure that stores of object references will be visible
543 // only after the object's initialization. So the callers of this
544 // procedure must indicate that the store requires `release'
545 // semantics, if the stored value is an object reference that might
546 // point to a new object and may become externally visible.
547 StoreNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, MemOrd mo)
548 : MemNode(c, mem, adr, at, val), _mo(mo) {
549 init_class_id(Class_Store);
550 }
551 StoreNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, Node *oop_store, MemOrd mo)
552 : MemNode(c, mem, adr, at, val, oop_store), _mo(mo) {
553 init_class_id(Class_Store);
554 }
555
556 inline bool is_unordered() const { return !is_release(); }
557 inline bool is_release() const {
558 assert((_mo == unordered || _mo == release), "unexpected");
559 return _mo == release;
560 }
561
562 // Conservatively release stores of object references in order to
563 // ensure visibility of object initialization.
564 static inline MemOrd release_if_reference(const BasicType t) {
565 #ifdef AARCH64
566 // AArch64 doesn't need a release store here because object
567 // initialization contains the necessary barriers.
568 return unordered;
569 #else
570 const MemOrd mo = (t == T_ARRAY ||
571 t == T_ADDRESS || // Might be the address of an object reference (`boxing').
572 t == T_OBJECT) ? release : unordered;
573 return mo;
574 #endif
575 }
576
577 // Polymorphic factory method
578 //
579 // We must ensure that stores of object references will be visible
580 // only after the object's initialization. So the callers of this
581 // procedure must indicate that the store requires `release'
582 // semantics, if the stored value is an object reference that might
583 // point to a new object and may become externally visible.
584 static StoreNode* make(PhaseGVN& gvn, Node *c, Node *mem, Node *adr,
585 const TypePtr* at, Node *val, BasicType bt, MemOrd mo);
586
587 virtual uint hash() const; // Check the type
588
589 // If the store is to Field memory and the pointer is non-null, we can
590 // zero out the control input.
591 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
592
593 // Compute a new Type for this node. Basically we just do the pre-check,
594 // then call the virtual add() to set the type.
595 virtual const Type* Value(PhaseGVN* phase) const;
596
597 // Check for identity function on memory (Load then Store at same address)
598 virtual Node* Identity(PhaseGVN* phase);
599
600 // Do not match memory edge
601 virtual uint match_edge(uint idx) const;
602
603 virtual const Type *bottom_type() const; // returns Type::MEMORY
604
605 // Map a store opcode to its corresponding own opcode, trivially.
606 virtual int store_Opcode() const { return Opcode(); }
607
608 // have all possible loads of the value stored been optimized away?
609 bool value_never_loaded(PhaseTransform *phase) const;
610 };
611
612 //------------------------------StoreBNode-------------------------------------
613 // Store byte to memory
614 class StoreBNode : public StoreNode {
615 public:
616 StoreBNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, MemOrd mo)
617 : StoreNode(c, mem, adr, at, val, mo) {}
618 virtual int Opcode() const;
619 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
620 virtual BasicType memory_type() const { return T_BYTE; }
621 };
622
623 //------------------------------StoreCNode-------------------------------------
624 // Store char/short to memory
625 class StoreCNode : public StoreNode {
626 public:
627 StoreCNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, MemOrd mo)
628 : StoreNode(c, mem, adr, at, val, mo) {}
629 virtual int Opcode() const;
630 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
631 virtual BasicType memory_type() const { return T_CHAR; }
632 };
633
634 //------------------------------StoreINode-------------------------------------
635 // Store int to memory
636 class StoreINode : public StoreNode {
637 public:
638 StoreINode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, MemOrd mo)
639 : StoreNode(c, mem, adr, at, val, mo) {}
640 virtual int Opcode() const;
641 virtual BasicType memory_type() const { return T_INT; }
642 };
643
644 //------------------------------StoreLNode-------------------------------------
645 // Store long to memory
646 class StoreLNode : public StoreNode {
647 virtual uint hash() const { return StoreNode::hash() + _require_atomic_access; }
648 virtual uint cmp( const Node &n ) const {
649 return _require_atomic_access == ((StoreLNode&)n)._require_atomic_access
650 && StoreNode::cmp(n);
651 }
652 virtual uint size_of() const { return sizeof(*this); }
653 const bool _require_atomic_access; // is piecewise store forbidden?
654
655 public:
656 StoreLNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, MemOrd mo, bool require_atomic_access = false)
657 : StoreNode(c, mem, adr, at, val, mo), _require_atomic_access(require_atomic_access) {}
658 virtual int Opcode() const;
659 virtual BasicType memory_type() const { return T_LONG; }
660 bool require_atomic_access() const { return _require_atomic_access; }
661 static StoreLNode* make_atomic(Node* ctl, Node* mem, Node* adr, const TypePtr* adr_type, Node* val, MemOrd mo);
662 #ifndef PRODUCT
663 virtual void dump_spec(outputStream *st) const {
664 StoreNode::dump_spec(st);
665 if (_require_atomic_access) st->print(" Atomic!");
666 }
667 #endif
668 };
669
670 //------------------------------StoreFNode-------------------------------------
671 // Store float to memory
672 class StoreFNode : public StoreNode {
673 public:
674 StoreFNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, MemOrd mo)
675 : StoreNode(c, mem, adr, at, val, mo) {}
676 virtual int Opcode() const;
677 virtual BasicType memory_type() const { return T_FLOAT; }
678 };
679
680 //------------------------------StoreDNode-------------------------------------
681 // Store double to memory
682 class StoreDNode : public StoreNode {
683 virtual uint hash() const { return StoreNode::hash() + _require_atomic_access; }
684 virtual uint cmp( const Node &n ) const {
685 return _require_atomic_access == ((StoreDNode&)n)._require_atomic_access
686 && StoreNode::cmp(n);
687 }
688 virtual uint size_of() const { return sizeof(*this); }
689 const bool _require_atomic_access; // is piecewise store forbidden?
690 public:
691 StoreDNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val,
692 MemOrd mo, bool require_atomic_access = false)
693 : StoreNode(c, mem, adr, at, val, mo), _require_atomic_access(require_atomic_access) {}
694 virtual int Opcode() const;
695 virtual BasicType memory_type() const { return T_DOUBLE; }
696 bool require_atomic_access() const { return _require_atomic_access; }
697 static StoreDNode* make_atomic(Node* ctl, Node* mem, Node* adr, const TypePtr* adr_type, Node* val, MemOrd mo);
698 #ifndef PRODUCT
699 virtual void dump_spec(outputStream *st) const {
700 StoreNode::dump_spec(st);
701 if (_require_atomic_access) st->print(" Atomic!");
702 }
703 #endif
704
705 };
706
707 //------------------------------StorePNode-------------------------------------
708 // Store pointer to memory
709 class StorePNode : public StoreNode {
710 public:
711 StorePNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, MemOrd mo)
712 : StoreNode(c, mem, adr, at, val, mo) {}
713 virtual int Opcode() const;
714 virtual BasicType memory_type() const { return T_ADDRESS; }
715 };
716
717 //------------------------------StoreNNode-------------------------------------
718 // Store narrow oop to memory
719 class StoreNNode : public StoreNode {
720 public:
721 StoreNNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, MemOrd mo)
722 : StoreNode(c, mem, adr, at, val, mo) {}
723 virtual int Opcode() const;
724 virtual BasicType memory_type() const { return T_NARROWOOP; }
725 };
726
727 //------------------------------StoreNKlassNode--------------------------------------
728 // Store narrow klass to memory
729 class StoreNKlassNode : public StoreNNode {
730 public:
731 StoreNKlassNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, MemOrd mo)
732 : StoreNNode(c, mem, adr, at, val, mo) {}
733 virtual int Opcode() const;
734 virtual BasicType memory_type() const { return T_NARROWKLASS; }
735 };
736
737 //------------------------------StoreCMNode-----------------------------------
738 // Store card-mark byte to memory for CM
739 // The last StoreCM before a SafePoint must be preserved and occur after its "oop" store
740 // Preceeding equivalent StoreCMs may be eliminated.
741 class StoreCMNode : public StoreNode {
742 private:
743 virtual uint hash() const { return StoreNode::hash() + _oop_alias_idx; }
744 virtual uint cmp( const Node &n ) const {
745 return _oop_alias_idx == ((StoreCMNode&)n)._oop_alias_idx
746 && StoreNode::cmp(n);
747 }
748 virtual uint size_of() const { return sizeof(*this); }
749 int _oop_alias_idx; // The alias_idx of OopStore
750
751 public:
752 StoreCMNode( Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, Node *oop_store, int oop_alias_idx ) :
753 StoreNode(c, mem, adr, at, val, oop_store, MemNode::release),
754 _oop_alias_idx(oop_alias_idx) {
755 assert(_oop_alias_idx >= Compile::AliasIdxRaw ||
756 _oop_alias_idx == Compile::AliasIdxBot && Compile::current()->AliasLevel() == 0,
757 "bad oop alias idx");
758 }
759 virtual int Opcode() const;
760 virtual Node* Identity(PhaseGVN* phase);
761 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
762 virtual const Type* Value(PhaseGVN* phase) const;
763 virtual BasicType memory_type() const { return T_VOID; } // unspecific
764 int oop_alias_idx() const { return _oop_alias_idx; }
765 };
766
767 //------------------------------LoadPLockedNode---------------------------------
768 // Load-locked a pointer from memory (either object or array).
769 // On Sparc & Intel this is implemented as a normal pointer load.
770 // On PowerPC and friends it's a real load-locked.
771 class LoadPLockedNode : public LoadPNode {
772 public:
773 LoadPLockedNode(Node *c, Node *mem, Node *adr, MemOrd mo)
774 : LoadPNode(c, mem, adr, TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM, mo) {}
775 virtual int Opcode() const;
776 virtual int store_Opcode() const { return Op_StorePConditional; }
777 virtual bool depends_only_on_test() const { return true; }
778 };
779
780 //------------------------------SCMemProjNode---------------------------------------
781 // This class defines a projection of the memory state of a store conditional node.
782 // These nodes return a value, but also update memory.
783 class SCMemProjNode : public ProjNode {
784 public:
785 enum {SCMEMPROJCON = (uint)-2};
786 SCMemProjNode( Node *src) : ProjNode( src, SCMEMPROJCON) { }
787 virtual int Opcode() const;
788 virtual bool is_CFG() const { return false; }
789 virtual const Type *bottom_type() const {return Type::MEMORY;}
790 virtual const TypePtr *adr_type() const {
791 Node* ctrl = in(0);
792 if (ctrl == NULL) return NULL; // node is dead
793 return ctrl->in(MemNode::Memory)->adr_type();
794 }
795 virtual uint ideal_reg() const { return 0;} // memory projections don't have a register
796 virtual const Type* Value(PhaseGVN* phase) const;
797 #ifndef PRODUCT
798 virtual void dump_spec(outputStream *st) const {};
799 #endif
800 };
801
802 //------------------------------LoadStoreNode---------------------------
803 // Note: is_Mem() method returns 'true' for this class.
804 class LoadStoreNode : public Node {
805 private:
806 const Type* const _type; // What kind of value is loaded?
807 const TypePtr* _adr_type; // What kind of memory is being addressed?
808 virtual uint size_of() const; // Size is bigger
809 public:
810 LoadStoreNode( Node *c, Node *mem, Node *adr, Node *val, const TypePtr* at, const Type* rt, uint required );
811 virtual bool depends_only_on_test() const { return false; }
812 virtual uint match_edge(uint idx) const { return idx == MemNode::Address || idx == MemNode::ValueIn; }
813
814 virtual const Type *bottom_type() const { return _type; }
815 virtual uint ideal_reg() const;
816 virtual const class TypePtr *adr_type() const { return _adr_type; } // returns bottom_type of address
817
818 bool result_not_used() const;
819 };
820
821 class LoadStoreConditionalNode : public LoadStoreNode {
822 public:
823 enum {
824 ExpectedIn = MemNode::ValueIn+1 // One more input than MemNode
825 };
826 LoadStoreConditionalNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex);
827 };
828
829 //------------------------------StorePConditionalNode---------------------------
830 // Conditionally store pointer to memory, if no change since prior
831 // load-locked. Sets flags for success or failure of the store.
832 class StorePConditionalNode : public LoadStoreConditionalNode {
833 public:
834 StorePConditionalNode( Node *c, Node *mem, Node *adr, Node *val, Node *ll ) : LoadStoreConditionalNode(c, mem, adr, val, ll) { }
835 virtual int Opcode() const;
836 // Produces flags
837 virtual uint ideal_reg() const { return Op_RegFlags; }
838 };
839
840 //------------------------------StoreIConditionalNode---------------------------
841 // Conditionally store int to memory, if no change since prior
842 // load-locked. Sets flags for success or failure of the store.
843 class StoreIConditionalNode : public LoadStoreConditionalNode {
844 public:
845 StoreIConditionalNode( Node *c, Node *mem, Node *adr, Node *val, Node *ii ) : LoadStoreConditionalNode(c, mem, adr, val, ii) { }
846 virtual int Opcode() const;
847 // Produces flags
848 virtual uint ideal_reg() const { return Op_RegFlags; }
849 };
850
851 //------------------------------StoreLConditionalNode---------------------------
852 // Conditionally store long to memory, if no change since prior
853 // load-locked. Sets flags for success or failure of the store.
854 class StoreLConditionalNode : public LoadStoreConditionalNode {
855 public:
856 StoreLConditionalNode( Node *c, Node *mem, Node *adr, Node *val, Node *ll ) : LoadStoreConditionalNode(c, mem, adr, val, ll) { }
857 virtual int Opcode() const;
858 // Produces flags
859 virtual uint ideal_reg() const { return Op_RegFlags; }
860 };
861
862 class CompareAndSwapNode : public LoadStoreConditionalNode {
863 private:
864 const MemNode::MemOrd _mem_ord;
865 public:
866 CompareAndSwapNode( Node *c, Node *mem, Node *adr, Node *val, Node *ex, MemNode::MemOrd mem_ord) : LoadStoreConditionalNode(c, mem, adr, val, ex), _mem_ord(mem_ord) {}
867 MemNode::MemOrd order() const {
868 return _mem_ord;
869 }
870 };
871
872 class CompareAndExchangeNode : public LoadStoreNode {
873 private:
874 const MemNode::MemOrd _mem_ord;
875 public:
876 enum {
877 ExpectedIn = MemNode::ValueIn+1 // One more input than MemNode
878 };
879 CompareAndExchangeNode( Node *c, Node *mem, Node *adr, Node *val, Node *ex, MemNode::MemOrd mem_ord, const TypePtr* at, const Type* t) :
880 LoadStoreNode(c, mem, adr, val, at, t, 5), _mem_ord(mem_ord) {
881 init_req(ExpectedIn, ex );
882 }
883
884 MemNode::MemOrd order() const {
885 return _mem_ord;
886 }
887 };
888
889 //------------------------------CompareAndSwapBNode---------------------------
890 class CompareAndSwapBNode : public CompareAndSwapNode {
891 public:
892 CompareAndSwapBNode( Node *c, Node *mem, Node *adr, Node *val, Node *ex, MemNode::MemOrd mem_ord) : CompareAndSwapNode(c, mem, adr, val, ex, mem_ord) { }
893 virtual int Opcode() const;
894 };
895
896 //------------------------------CompareAndSwapSNode---------------------------
897 class CompareAndSwapSNode : public CompareAndSwapNode {
898 public:
899 CompareAndSwapSNode( Node *c, Node *mem, Node *adr, Node *val, Node *ex, MemNode::MemOrd mem_ord) : CompareAndSwapNode(c, mem, adr, val, ex, mem_ord) { }
900 virtual int Opcode() const;
901 };
902
903 //------------------------------CompareAndSwapINode---------------------------
904 class CompareAndSwapINode : public CompareAndSwapNode {
905 public:
906 CompareAndSwapINode( Node *c, Node *mem, Node *adr, Node *val, Node *ex, MemNode::MemOrd mem_ord) : CompareAndSwapNode(c, mem, adr, val, ex, mem_ord) { }
907 virtual int Opcode() const;
908 };
909
910 //------------------------------CompareAndSwapLNode---------------------------
911 class CompareAndSwapLNode : public CompareAndSwapNode {
912 public:
913 CompareAndSwapLNode( Node *c, Node *mem, Node *adr, Node *val, Node *ex, MemNode::MemOrd mem_ord) : CompareAndSwapNode(c, mem, adr, val, ex, mem_ord) { }
914 virtual int Opcode() const;
915 };
916
917 //------------------------------CompareAndSwapPNode---------------------------
918 class CompareAndSwapPNode : public CompareAndSwapNode {
919 public:
920 CompareAndSwapPNode( Node *c, Node *mem, Node *adr, Node *val, Node *ex, MemNode::MemOrd mem_ord) : CompareAndSwapNode(c, mem, adr, val, ex, mem_ord) { }
921 virtual int Opcode() const;
922 };
923
924 //------------------------------CompareAndSwapNNode---------------------------
925 class CompareAndSwapNNode : public CompareAndSwapNode {
926 public:
927 CompareAndSwapNNode( Node *c, Node *mem, Node *adr, Node *val, Node *ex, MemNode::MemOrd mem_ord) : CompareAndSwapNode(c, mem, adr, val, ex, mem_ord) { }
928 virtual int Opcode() const;
929 };
930
931 //------------------------------WeakCompareAndSwapBNode---------------------------
932 class WeakCompareAndSwapBNode : public CompareAndSwapNode {
933 public:
934 WeakCompareAndSwapBNode( Node *c, Node *mem, Node *adr, Node *val, Node *ex, MemNode::MemOrd mem_ord) : CompareAndSwapNode(c, mem, adr, val, ex, mem_ord) { }
935 virtual int Opcode() const;
936 };
937
938 //------------------------------WeakCompareAndSwapSNode---------------------------
939 class WeakCompareAndSwapSNode : public CompareAndSwapNode {
940 public:
941 WeakCompareAndSwapSNode( Node *c, Node *mem, Node *adr, Node *val, Node *ex, MemNode::MemOrd mem_ord) : CompareAndSwapNode(c, mem, adr, val, ex, mem_ord) { }
942 virtual int Opcode() const;
943 };
944
945 //------------------------------WeakCompareAndSwapINode---------------------------
946 class WeakCompareAndSwapINode : public CompareAndSwapNode {
947 public:
948 WeakCompareAndSwapINode( Node *c, Node *mem, Node *adr, Node *val, Node *ex, MemNode::MemOrd mem_ord) : CompareAndSwapNode(c, mem, adr, val, ex, mem_ord) { }
949 virtual int Opcode() const;
950 };
951
952 //------------------------------WeakCompareAndSwapLNode---------------------------
953 class WeakCompareAndSwapLNode : public CompareAndSwapNode {
954 public:
955 WeakCompareAndSwapLNode( Node *c, Node *mem, Node *adr, Node *val, Node *ex, MemNode::MemOrd mem_ord) : CompareAndSwapNode(c, mem, adr, val, ex, mem_ord) { }
956 virtual int Opcode() const;
957 };
958
959 //------------------------------WeakCompareAndSwapPNode---------------------------
960 class WeakCompareAndSwapPNode : public CompareAndSwapNode {
961 public:
962 WeakCompareAndSwapPNode( Node *c, Node *mem, Node *adr, Node *val, Node *ex, MemNode::MemOrd mem_ord) : CompareAndSwapNode(c, mem, adr, val, ex, mem_ord) { }
963 virtual int Opcode() const;
964 };
965
966 //------------------------------WeakCompareAndSwapNNode---------------------------
967 class WeakCompareAndSwapNNode : public CompareAndSwapNode {
968 public:
969 WeakCompareAndSwapNNode( Node *c, Node *mem, Node *adr, Node *val, Node *ex, MemNode::MemOrd mem_ord) : CompareAndSwapNode(c, mem, adr, val, ex, mem_ord) { }
970 virtual int Opcode() const;
971 };
972
973 //------------------------------CompareAndExchangeBNode---------------------------
974 class CompareAndExchangeBNode : public CompareAndExchangeNode {
975 public:
976 CompareAndExchangeBNode( Node *c, Node *mem, Node *adr, Node *val, Node *ex, const TypePtr* at, MemNode::MemOrd mem_ord) : CompareAndExchangeNode(c, mem, adr, val, ex, mem_ord, at, TypeInt::BYTE) { }
977 virtual int Opcode() const;
978 };
979
980
981 //------------------------------CompareAndExchangeSNode---------------------------
982 class CompareAndExchangeSNode : public CompareAndExchangeNode {
983 public:
984 CompareAndExchangeSNode( Node *c, Node *mem, Node *adr, Node *val, Node *ex, const TypePtr* at, MemNode::MemOrd mem_ord) : CompareAndExchangeNode(c, mem, adr, val, ex, mem_ord, at, TypeInt::SHORT) { }
985 virtual int Opcode() const;
986 };
987
988 //------------------------------CompareAndExchangeLNode---------------------------
989 class CompareAndExchangeLNode : public CompareAndExchangeNode {
990 public:
991 CompareAndExchangeLNode( Node *c, Node *mem, Node *adr, Node *val, Node *ex, const TypePtr* at, MemNode::MemOrd mem_ord) : CompareAndExchangeNode(c, mem, adr, val, ex, mem_ord, at, TypeLong::LONG) { }
992 virtual int Opcode() const;
993 };
994
995
996 //------------------------------CompareAndExchangeINode---------------------------
997 class CompareAndExchangeINode : public CompareAndExchangeNode {
998 public:
999 CompareAndExchangeINode( Node *c, Node *mem, Node *adr, Node *val, Node *ex, const TypePtr* at, MemNode::MemOrd mem_ord) : CompareAndExchangeNode(c, mem, adr, val, ex, mem_ord, at, TypeInt::INT) { }
1000 virtual int Opcode() const;
1001 };
1002
1003
1004 //------------------------------CompareAndExchangePNode---------------------------
1005 class CompareAndExchangePNode : public CompareAndExchangeNode {
1006 public:
1007 CompareAndExchangePNode( Node *c, Node *mem, Node *adr, Node *val, Node *ex, const TypePtr* at, const Type* t, MemNode::MemOrd mem_ord) : CompareAndExchangeNode(c, mem, adr, val, ex, mem_ord, at, t) { }
1008 virtual int Opcode() const;
1009 };
1010
1011 //------------------------------CompareAndExchangeNNode---------------------------
1012 class CompareAndExchangeNNode : public CompareAndExchangeNode {
1013 public:
1014 CompareAndExchangeNNode( Node *c, Node *mem, Node *adr, Node *val, Node *ex, const TypePtr* at, const Type* t, MemNode::MemOrd mem_ord) : CompareAndExchangeNode(c, mem, adr, val, ex, mem_ord, at, t) { }
1015 virtual int Opcode() const;
1016 };
1017
1018 //------------------------------GetAndAddBNode---------------------------
1019 class GetAndAddBNode : public LoadStoreNode {
1020 public:
1021 GetAndAddBNode( Node *c, Node *mem, Node *adr, Node *val, const TypePtr* at ) : LoadStoreNode(c, mem, adr, val, at, TypeInt::BYTE, 4) { }
1022 virtual int Opcode() const;
1023 };
1024
1025 //------------------------------GetAndAddSNode---------------------------
1026 class GetAndAddSNode : public LoadStoreNode {
1027 public:
1028 GetAndAddSNode( Node *c, Node *mem, Node *adr, Node *val, const TypePtr* at ) : LoadStoreNode(c, mem, adr, val, at, TypeInt::SHORT, 4) { }
1029 virtual int Opcode() const;
1030 };
1031
1032 //------------------------------GetAndAddINode---------------------------
1033 class GetAndAddINode : public LoadStoreNode {
1034 public:
1035 GetAndAddINode( Node *c, Node *mem, Node *adr, Node *val, const TypePtr* at ) : LoadStoreNode(c, mem, adr, val, at, TypeInt::INT, 4) { }
1036 virtual int Opcode() const;
1037 };
1038
1039 //------------------------------GetAndAddLNode---------------------------
1040 class GetAndAddLNode : public LoadStoreNode {
1041 public:
1042 GetAndAddLNode( Node *c, Node *mem, Node *adr, Node *val, const TypePtr* at ) : LoadStoreNode(c, mem, adr, val, at, TypeLong::LONG, 4) { }
1043 virtual int Opcode() const;
1044 };
1045
1046 //------------------------------GetAndSetBNode---------------------------
1047 class GetAndSetBNode : public LoadStoreNode {
1048 public:
1049 GetAndSetBNode( Node *c, Node *mem, Node *adr, Node *val, const TypePtr* at ) : LoadStoreNode(c, mem, adr, val, at, TypeInt::BYTE, 4) { }
1050 virtual int Opcode() const;
1051 };
1052
1053 //------------------------------GetAndSetSNode---------------------------
1054 class GetAndSetSNode : public LoadStoreNode {
1055 public:
1056 GetAndSetSNode( Node *c, Node *mem, Node *adr, Node *val, const TypePtr* at ) : LoadStoreNode(c, mem, adr, val, at, TypeInt::SHORT, 4) { }
1057 virtual int Opcode() const;
1058 };
1059
1060 //------------------------------GetAndSetINode---------------------------
1061 class GetAndSetINode : public LoadStoreNode {
1062 public:
1063 GetAndSetINode( Node *c, Node *mem, Node *adr, Node *val, const TypePtr* at ) : LoadStoreNode(c, mem, adr, val, at, TypeInt::INT, 4) { }
1064 virtual int Opcode() const;
1065 };
1066
1067 //------------------------------GetAndSetLNode---------------------------
1068 class GetAndSetLNode : public LoadStoreNode {
1069 public:
1070 GetAndSetLNode( Node *c, Node *mem, Node *adr, Node *val, const TypePtr* at ) : LoadStoreNode(c, mem, adr, val, at, TypeLong::LONG, 4) { }
1071 virtual int Opcode() const;
1072 };
1073
1074 //------------------------------GetAndSetPNode---------------------------
1075 class GetAndSetPNode : public LoadStoreNode {
1076 public:
1077 GetAndSetPNode( Node *c, Node *mem, Node *adr, Node *val, const TypePtr* at, const Type* t ) : LoadStoreNode(c, mem, adr, val, at, t, 4) { }
1078 virtual int Opcode() const;
1079 };
1080
1081 //------------------------------GetAndSetNNode---------------------------
1082 class GetAndSetNNode : public LoadStoreNode {
1083 public:
1084 GetAndSetNNode( Node *c, Node *mem, Node *adr, Node *val, const TypePtr* at, const Type* t ) : LoadStoreNode(c, mem, adr, val, at, t, 4) { }
1085 virtual int Opcode() const;
1086 };
1087
1088 //------------------------------ClearArray-------------------------------------
1089 class ClearArrayNode: public Node {
1090 private:
1091 bool _is_large;
1092 public:
1093 ClearArrayNode( Node *ctrl, Node *arymem, Node *word_cnt, Node *base, bool is_large)
1094 : Node(ctrl,arymem,word_cnt,base), _is_large(is_large) {
1095 init_class_id(Class_ClearArray);
1096 }
1097 virtual int Opcode() const;
1098 virtual const Type *bottom_type() const { return Type::MEMORY; }
1099 // ClearArray modifies array elements, and so affects only the
1100 // array memory addressed by the bottom_type of its base address.
1101 virtual const class TypePtr *adr_type() const;
1102 virtual Node* Identity(PhaseGVN* phase);
1103 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
1104 virtual uint match_edge(uint idx) const;
1105 bool is_large() const { return _is_large; }
1106
1107 // Clear the given area of an object or array.
1108 // The start offset must always be aligned mod BytesPerInt.
1109 // The end offset must always be aligned mod BytesPerLong.
1110 // Return the new memory.
1111 static Node* clear_memory(Node* control, Node* mem, Node* dest,
1112 intptr_t start_offset,
1113 intptr_t end_offset,
1114 PhaseGVN* phase);
1115 static Node* clear_memory(Node* control, Node* mem, Node* dest,
1116 intptr_t start_offset,
1117 Node* end_offset,
1118 PhaseGVN* phase);
1119 static Node* clear_memory(Node* control, Node* mem, Node* dest,
1120 Node* start_offset,
1121 Node* end_offset,
1122 PhaseGVN* phase);
1123 // Return allocation input memory edge if it is different instance
1124 // or itself if it is the one we are looking for.
1125 static bool step_through(Node** np, uint instance_id, PhaseTransform* phase);
1126 };
1127
1128 //------------------------------MemBar-----------------------------------------
1129 // There are different flavors of Memory Barriers to match the Java Memory
1130 // Model. Monitor-enter and volatile-load act as Aquires: no following ref
1131 // can be moved to before them. We insert a MemBar-Acquire after a FastLock or
1132 // volatile-load. Monitor-exit and volatile-store act as Release: no
1133 // preceding ref can be moved to after them. We insert a MemBar-Release
1134 // before a FastUnlock or volatile-store. All volatiles need to be
1135 // serialized, so we follow all volatile-stores with a MemBar-Volatile to
1136 // separate it from any following volatile-load.
1137 class MemBarNode: public MultiNode {
1138 virtual uint hash() const ; // { return NO_HASH; }
1139 virtual uint cmp( const Node &n ) const ; // Always fail, except on self
1140
1141 virtual uint size_of() const { return sizeof(*this); }
1142 // Memory type this node is serializing. Usually either rawptr or bottom.
1143 const TypePtr* _adr_type;
1144
1145 public:
1146 enum {
1147 Precedent = TypeFunc::Parms // optional edge to force precedence
1148 };
1149 MemBarNode(Compile* C, int alias_idx, Node* precedent);
1150 virtual int Opcode() const = 0;
1151 virtual const class TypePtr *adr_type() const { return _adr_type; }
1152 virtual const Type* Value(PhaseGVN* phase) const;
1153 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
1154 virtual uint match_edge(uint idx) const { return 0; }
1155 virtual const Type *bottom_type() const { return TypeTuple::MEMBAR; }
1156 virtual Node *match(const ProjNode *proj, const Matcher *m, const RegMask* mask);
1157 // Factory method. Builds a wide or narrow membar.
1158 // Optional 'precedent' becomes an extra edge if not null.
1159 static MemBarNode* make(Compile* C, int opcode,
1160 int alias_idx = Compile::AliasIdxBot,
1161 Node* precedent = NULL);
1162 };
1163
1164 // "Acquire" - no following ref can move before (but earlier refs can
1165 // follow, like an early Load stalled in cache). Requires multi-cpu
1166 // visibility. Inserted after a volatile load.
1167 class MemBarAcquireNode: public MemBarNode {
1168 public:
1169 MemBarAcquireNode(Compile* C, int alias_idx, Node* precedent)
1170 : MemBarNode(C, alias_idx, precedent) {}
1171 virtual int Opcode() const;
1172 };
1173
1174 // "Acquire" - no following ref can move before (but earlier refs can
1175 // follow, like an early Load stalled in cache). Requires multi-cpu
1176 // visibility. Inserted independ of any load, as required
1177 // for intrinsic Unsafe.loadFence().
1178 class LoadFenceNode: public MemBarNode {
1179 public:
1180 LoadFenceNode(Compile* C, int alias_idx, Node* precedent)
1181 : MemBarNode(C, alias_idx, precedent) {}
1182 virtual int Opcode() const;
1183 };
1184
1185 // "Release" - no earlier ref can move after (but later refs can move
1186 // up, like a speculative pipelined cache-hitting Load). Requires
1187 // multi-cpu visibility. Inserted before a volatile store.
1188 class MemBarReleaseNode: public MemBarNode {
1189 public:
1190 MemBarReleaseNode(Compile* C, int alias_idx, Node* precedent)
1191 : MemBarNode(C, alias_idx, precedent) {}
1192 virtual int Opcode() const;
1193 };
1194
1195 // "Release" - no earlier ref can move after (but later refs can move
1196 // up, like a speculative pipelined cache-hitting Load). Requires
1197 // multi-cpu visibility. Inserted independent of any store, as required
1198 // for intrinsic Unsafe.storeFence().
1199 class StoreFenceNode: public MemBarNode {
1200 public:
1201 StoreFenceNode(Compile* C, int alias_idx, Node* precedent)
1202 : MemBarNode(C, alias_idx, precedent) {}
1203 virtual int Opcode() const;
1204 };
1205
1206 // "Acquire" - no following ref can move before (but earlier refs can
1207 // follow, like an early Load stalled in cache). Requires multi-cpu
1208 // visibility. Inserted after a FastLock.
1209 class MemBarAcquireLockNode: public MemBarNode {
1210 public:
1211 MemBarAcquireLockNode(Compile* C, int alias_idx, Node* precedent)
1212 : MemBarNode(C, alias_idx, precedent) {}
1213 virtual int Opcode() const;
1214 };
1215
1216 // "Release" - no earlier ref can move after (but later refs can move
1217 // up, like a speculative pipelined cache-hitting Load). Requires
1218 // multi-cpu visibility. Inserted before a FastUnLock.
1219 class MemBarReleaseLockNode: public MemBarNode {
1220 public:
1221 MemBarReleaseLockNode(Compile* C, int alias_idx, Node* precedent)
1222 : MemBarNode(C, alias_idx, precedent) {}
1223 virtual int Opcode() const;
1224 };
1225
1226 class MemBarStoreStoreNode: public MemBarNode {
1227 public:
1228 MemBarStoreStoreNode(Compile* C, int alias_idx, Node* precedent)
1229 : MemBarNode(C, alias_idx, precedent) {
1230 init_class_id(Class_MemBarStoreStore);
1231 }
1232 virtual int Opcode() const;
1233 };
1234
1235 // Ordering between a volatile store and a following volatile load.
1236 // Requires multi-CPU visibility?
1237 class MemBarVolatileNode: public MemBarNode {
1238 public:
1239 MemBarVolatileNode(Compile* C, int alias_idx, Node* precedent)
1240 : MemBarNode(C, alias_idx, precedent) {}
1241 virtual int Opcode() const;
1242 };
1243
1244 // Ordering within the same CPU. Used to order unsafe memory references
1245 // inside the compiler when we lack alias info. Not needed "outside" the
1246 // compiler because the CPU does all the ordering for us.
1247 class MemBarCPUOrderNode: public MemBarNode {
1248 public:
1249 MemBarCPUOrderNode(Compile* C, int alias_idx, Node* precedent)
1250 : MemBarNode(C, alias_idx, precedent) {}
1251 virtual int Opcode() const;
1252 virtual uint ideal_reg() const { return 0; } // not matched in the AD file
1253 };
1254
1255 class OnSpinWaitNode: public MemBarNode {
1256 public:
1257 OnSpinWaitNode(Compile* C, int alias_idx, Node* precedent)
1258 : MemBarNode(C, alias_idx, precedent) {}
1259 virtual int Opcode() const;
1260 };
1261
1262 // Isolation of object setup after an AllocateNode and before next safepoint.
1263 // (See comment in memnode.cpp near InitializeNode::InitializeNode for semantics.)
1264 class InitializeNode: public MemBarNode {
1265 friend class AllocateNode;
1266
1267 enum {
1268 Incomplete = 0,
1269 Complete = 1,
1270 WithArraycopy = 2
1271 };
1272 int _is_complete;
1273
1274 bool _does_not_escape;
1275
1276 public:
1277 enum {
1278 Control = TypeFunc::Control,
1279 Memory = TypeFunc::Memory, // MergeMem for states affected by this op
1280 RawAddress = TypeFunc::Parms+0, // the newly-allocated raw address
1281 RawStores = TypeFunc::Parms+1 // zero or more stores (or TOP)
1282 };
1283
1284 InitializeNode(Compile* C, int adr_type, Node* rawoop);
1285 virtual int Opcode() const;
1286 virtual uint size_of() const { return sizeof(*this); }
1287 virtual uint ideal_reg() const { return 0; } // not matched in the AD file
1288 virtual const RegMask &in_RegMask(uint) const; // mask for RawAddress
1289
1290 // Manage incoming memory edges via a MergeMem on in(Memory):
1291 Node* memory(uint alias_idx);
1292
1293 // The raw memory edge coming directly from the Allocation.
1294 // The contents of this memory are *always* all-zero-bits.
1295 Node* zero_memory() { return memory(Compile::AliasIdxRaw); }
1296
1297 // Return the corresponding allocation for this initialization (or null if none).
1298 // (Note: Both InitializeNode::allocation and AllocateNode::initialization
1299 // are defined in graphKit.cpp, which sets up the bidirectional relation.)
1300 AllocateNode* allocation();
1301
1302 // Anything other than zeroing in this init?
1303 bool is_non_zero();
1304
1305 // An InitializeNode must completed before macro expansion is done.
1306 // Completion requires that the AllocateNode must be followed by
1307 // initialization of the new memory to zero, then to any initializers.
1308 bool is_complete() { return _is_complete != Incomplete; }
1309 bool is_complete_with_arraycopy() { return (_is_complete & WithArraycopy) != 0; }
1310
1311 // Mark complete. (Must not yet be complete.)
1312 void set_complete(PhaseGVN* phase);
1313 void set_complete_with_arraycopy() { _is_complete = Complete | WithArraycopy; }
1314
1315 bool does_not_escape() { return _does_not_escape; }
1316 void set_does_not_escape() { _does_not_escape = true; }
1317
1318 #ifdef ASSERT
1319 // ensure all non-degenerate stores are ordered and non-overlapping
1320 bool stores_are_sane(PhaseTransform* phase);
1321 #endif //ASSERT
1322
1323 // See if this store can be captured; return offset where it initializes.
1324 // Return 0 if the store cannot be moved (any sort of problem).
1325 intptr_t can_capture_store(StoreNode* st, PhaseTransform* phase, bool can_reshape);
1326
1327 // Capture another store; reformat it to write my internal raw memory.
1328 // Return the captured copy, else NULL if there is some sort of problem.
1329 Node* capture_store(StoreNode* st, intptr_t start, PhaseTransform* phase, bool can_reshape);
1330
1331 // Find captured store which corresponds to the range [start..start+size).
1332 // Return my own memory projection (meaning the initial zero bits)
1333 // if there is no such store. Return NULL if there is a problem.
1334 Node* find_captured_store(intptr_t start, int size_in_bytes, PhaseTransform* phase);
1335
1336 // Called when the associated AllocateNode is expanded into CFG.
1337 Node* complete_stores(Node* rawctl, Node* rawmem, Node* rawptr,
1338 intptr_t header_size, Node* size_in_bytes,
1339 PhaseGVN* phase);
1340
1341 private:
1342 void remove_extra_zeroes();
1343
1344 // Find out where a captured store should be placed (or already is placed).
1345 int captured_store_insertion_point(intptr_t start, int size_in_bytes,
1346 PhaseTransform* phase);
1347
1348 static intptr_t get_store_offset(Node* st, PhaseTransform* phase);
1349
1350 Node* make_raw_address(intptr_t offset, PhaseTransform* phase);
1351
1352 bool detect_init_independence(Node* n, int& count);
1353
1354 void coalesce_subword_stores(intptr_t header_size, Node* size_in_bytes,
1355 PhaseGVN* phase);
1356
1357 intptr_t find_next_fullword_store(uint i, PhaseGVN* phase);
1358 };
1359
1360 //------------------------------MergeMem---------------------------------------
1361 // (See comment in memnode.cpp near MergeMemNode::MergeMemNode for semantics.)
1362 class MergeMemNode: public Node {
1363 virtual uint hash() const ; // { return NO_HASH; }
1364 virtual uint cmp( const Node &n ) const ; // Always fail, except on self
1365 friend class MergeMemStream;
1366 MergeMemNode(Node* def); // clients use MergeMemNode::make
1367
1368 public:
1369 // If the input is a whole memory state, clone it with all its slices intact.
1370 // Otherwise, make a new memory state with just that base memory input.
1371 // In either case, the result is a newly created MergeMem.
1372 static MergeMemNode* make(Node* base_memory);
1373
1374 virtual int Opcode() const;
1375 virtual Node* Identity(PhaseGVN* phase);
1376 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
1377 virtual uint ideal_reg() const { return NotAMachineReg; }
1378 virtual uint match_edge(uint idx) const { return 0; }
1379 virtual const RegMask &out_RegMask() const;
1380 virtual const Type *bottom_type() const { return Type::MEMORY; }
1381 virtual const TypePtr *adr_type() const { return TypePtr::BOTTOM; }
1382 // sparse accessors
1383 // Fetch the previously stored "set_memory_at", or else the base memory.
1384 // (Caller should clone it if it is a phi-nest.)
1385 Node* memory_at(uint alias_idx) const;
1386 // set the memory, regardless of its previous value
1387 void set_memory_at(uint alias_idx, Node* n);
1388 // the "base" is the memory that provides the non-finite support
1389 Node* base_memory() const { return in(Compile::AliasIdxBot); }
1390 // warning: setting the base can implicitly set any of the other slices too
1391 void set_base_memory(Node* def);
1392 // sentinel value which denotes a copy of the base memory:
1393 Node* empty_memory() const { return in(Compile::AliasIdxTop); }
1394 static Node* make_empty_memory(); // where the sentinel comes from
1395 bool is_empty_memory(Node* n) const { assert((n == empty_memory()) == n->is_top(), "sanity"); return n->is_top(); }
1396 // hook for the iterator, to perform any necessary setup
1397 void iteration_setup(const MergeMemNode* other = NULL);
1398 // push sentinels until I am at least as long as the other (semantic no-op)
1399 void grow_to_match(const MergeMemNode* other);
1400 bool verify_sparse() const PRODUCT_RETURN0;
1401 #ifndef PRODUCT
1402 virtual void dump_spec(outputStream *st) const;
1403 #endif
1404 };
1405
1406 class MergeMemStream : public StackObj {
1407 private:
1408 MergeMemNode* _mm;
1409 const MergeMemNode* _mm2; // optional second guy, contributes non-empty iterations
1410 Node* _mm_base; // loop-invariant base memory of _mm
1411 int _idx;
1412 int _cnt;
1413 Node* _mem;
1414 Node* _mem2;
1415 int _cnt2;
1416
1417 void init(MergeMemNode* mm, const MergeMemNode* mm2 = NULL) {
1418 // subsume_node will break sparseness at times, whenever a memory slice
1419 // folds down to a copy of the base ("fat") memory. In such a case,
1420 // the raw edge will update to base, although it should be top.
1421 // This iterator will recognize either top or base_memory as an
1422 // "empty" slice. See is_empty, is_empty2, and next below.
1423 //
1424 // The sparseness property is repaired in MergeMemNode::Ideal.
1425 // As long as access to a MergeMem goes through this iterator
1426 // or the memory_at accessor, flaws in the sparseness will
1427 // never be observed.
1428 //
1429 // Also, iteration_setup repairs sparseness.
1430 assert(mm->verify_sparse(), "please, no dups of base");
1431 assert(mm2==NULL || mm2->verify_sparse(), "please, no dups of base");
1432
1433 _mm = mm;
1434 _mm_base = mm->base_memory();
1435 _mm2 = mm2;
1436 _cnt = mm->req();
1437 _idx = Compile::AliasIdxBot-1; // start at the base memory
1438 _mem = NULL;
1439 _mem2 = NULL;
1440 }
1441
1442 #ifdef ASSERT
1443 Node* check_memory() const {
1444 if (at_base_memory())
1445 return _mm->base_memory();
1446 else if ((uint)_idx < _mm->req() && !_mm->in(_idx)->is_top())
1447 return _mm->memory_at(_idx);
1448 else
1449 return _mm_base;
1450 }
1451 Node* check_memory2() const {
1452 return at_base_memory()? _mm2->base_memory(): _mm2->memory_at(_idx);
1453 }
1454 #endif
1455
1456 static bool match_memory(Node* mem, const MergeMemNode* mm, int idx) PRODUCT_RETURN0;
1457 void assert_synch() const {
1458 assert(!_mem || _idx >= _cnt || match_memory(_mem, _mm, _idx),
1459 "no side-effects except through the stream");
1460 }
1461
1462 public:
1463
1464 // expected usages:
1465 // for (MergeMemStream mms(mem->is_MergeMem()); next_non_empty(); ) { ... }
1466 // for (MergeMemStream mms(mem1, mem2); next_non_empty2(); ) { ... }
1467
1468 // iterate over one merge
1469 MergeMemStream(MergeMemNode* mm) {
1470 mm->iteration_setup();
1471 init(mm);
1472 debug_only(_cnt2 = 999);
1473 }
1474 // iterate in parallel over two merges
1475 // only iterates through non-empty elements of mm2
1476 MergeMemStream(MergeMemNode* mm, const MergeMemNode* mm2) {
1477 assert(mm2, "second argument must be a MergeMem also");
1478 ((MergeMemNode*)mm2)->iteration_setup(); // update hidden state
1479 mm->iteration_setup(mm2);
1480 init(mm, mm2);
1481 _cnt2 = mm2->req();
1482 }
1483 #ifdef ASSERT
1484 ~MergeMemStream() {
1485 assert_synch();
1486 }
1487 #endif
1488
1489 MergeMemNode* all_memory() const {
1490 return _mm;
1491 }
1492 Node* base_memory() const {
1493 assert(_mm_base == _mm->base_memory(), "no update to base memory, please");
1494 return _mm_base;
1495 }
1496 const MergeMemNode* all_memory2() const {
1497 assert(_mm2 != NULL, "");
1498 return _mm2;
1499 }
1500 bool at_base_memory() const {
1501 return _idx == Compile::AliasIdxBot;
1502 }
1503 int alias_idx() const {
1504 assert(_mem, "must call next 1st");
1505 return _idx;
1506 }
1507
1508 const TypePtr* adr_type() const {
1509 return Compile::current()->get_adr_type(alias_idx());
1510 }
1511
1512 const TypePtr* adr_type(Compile* C) const {
1513 return C->get_adr_type(alias_idx());
1514 }
1515 bool is_empty() const {
1516 assert(_mem, "must call next 1st");
1517 assert(_mem->is_top() == (_mem==_mm->empty_memory()), "correct sentinel");
1518 return _mem->is_top();
1519 }
1520 bool is_empty2() const {
1521 assert(_mem2, "must call next 1st");
1522 assert(_mem2->is_top() == (_mem2==_mm2->empty_memory()), "correct sentinel");
1523 return _mem2->is_top();
1524 }
1525 Node* memory() const {
1526 assert(!is_empty(), "must not be empty");
1527 assert_synch();
1528 return _mem;
1529 }
1530 // get the current memory, regardless of empty or non-empty status
1531 Node* force_memory() const {
1532 assert(!is_empty() || !at_base_memory(), "");
1533 // Use _mm_base to defend against updates to _mem->base_memory().
1534 Node *mem = _mem->is_top() ? _mm_base : _mem;
1535 assert(mem == check_memory(), "");
1536 return mem;
1537 }
1538 Node* memory2() const {
1539 assert(_mem2 == check_memory2(), "");
1540 return _mem2;
1541 }
1542 void set_memory(Node* mem) {
1543 if (at_base_memory()) {
1544 // Note that this does not change the invariant _mm_base.
1545 _mm->set_base_memory(mem);
1546 } else {
1547 _mm->set_memory_at(_idx, mem);
1548 }
1549 _mem = mem;
1550 assert_synch();
1551 }
1552
1553 // Recover from a side effect to the MergeMemNode.
1554 void set_memory() {
1555 _mem = _mm->in(_idx);
1556 }
1557
1558 bool next() { return next(false); }
1559 bool next2() { return next(true); }
1560
1561 bool next_non_empty() { return next_non_empty(false); }
1562 bool next_non_empty2() { return next_non_empty(true); }
1563 // next_non_empty2 can yield states where is_empty() is true
1564
1565 private:
1566 // find the next item, which might be empty
1567 bool next(bool have_mm2) {
1568 assert((_mm2 != NULL) == have_mm2, "use other next");
1569 assert_synch();
1570 if (++_idx < _cnt) {
1571 // Note: This iterator allows _mm to be non-sparse.
1572 // It behaves the same whether _mem is top or base_memory.
1573 _mem = _mm->in(_idx);
1574 if (have_mm2)
1575 _mem2 = _mm2->in((_idx < _cnt2) ? _idx : Compile::AliasIdxTop);
1576 return true;
1577 }
1578 return false;
1579 }
1580
1581 // find the next non-empty item
1582 bool next_non_empty(bool have_mm2) {
1583 while (next(have_mm2)) {
1584 if (!is_empty()) {
1585 // make sure _mem2 is filled in sensibly
1586 if (have_mm2 && _mem2->is_top()) _mem2 = _mm2->base_memory();
1587 return true;
1588 } else if (have_mm2 && !is_empty2()) {
1589 return true; // is_empty() == true
1590 }
1591 }
1592 return false;
1593 }
1594 };
1595
1596 //------------------------------Prefetch---------------------------------------
1597
1598 // Allocation prefetch which may fault, TLAB size have to be adjusted.
1599 class PrefetchAllocationNode : public Node {
1600 public:
1601 PrefetchAllocationNode(Node *mem, Node *adr) : Node(0,mem,adr) {}
1602 virtual int Opcode() const;
1603 virtual uint ideal_reg() const { return NotAMachineReg; }
1604 virtual uint match_edge(uint idx) const { return idx==2; }
1605 virtual const Type *bottom_type() const { return ( AllocatePrefetchStyle == 3 ) ? Type::MEMORY : Type::ABIO; }
1606 };
1607
1608 #endif // SHARE_VM_OPTO_MEMNODE_HPP