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