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