1 /*
2 * Copyright (c) 1997, 2013, 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
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
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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 public:
79 // Helpers for the optimizer. Documented in memnode.cpp.
80 static bool detect_ptr_independence(Node* p1, AllocateNode* a1,
81 Node* p2, AllocateNode* a2,
82 PhaseTransform* phase);
83 static bool adr_phi_is_loop_invariant(Node* adr_phi, Node* cast);
84
85 static Node *optimize_simple_memory_chain(Node *mchain, const TypeOopPtr *t_oop, Node *load, PhaseGVN *phase);
86 static Node *optimize_memory_chain(Node *mchain, const TypePtr *t_adr, Node *load, PhaseGVN *phase);
87 // This one should probably be a phase-specific function:
88 static bool all_controls_dominate(Node* dom, Node* sub);
89
90 // Find any cast-away of null-ness and keep its control.
91 static Node *Ideal_common_DU_postCCP( PhaseCCP *ccp, Node* n, Node* adr );
92 virtual Node *Ideal_DU_postCCP( PhaseCCP *ccp );
93
94 virtual const class TypePtr *adr_type() const; // returns bottom_type of address
95
96 // Shared code for Ideal methods:
97 Node *Ideal_common(PhaseGVN *phase, bool can_reshape); // Return -1 for short-circuit NULL.
98
99 // Helper function for adr_type() implementations.
100 static const TypePtr* calculate_adr_type(const Type* t, const TypePtr* cross_check = NULL);
101
102 // Raw access function, to allow copying of adr_type efficiently in
103 // product builds and retain the debug info for debug builds.
104 const TypePtr *raw_adr_type() const {
105 #ifdef ASSERT
106 return _adr_type;
107 #else
108 return 0;
109 #endif
110 }
111
112 // Map a load or store opcode to its corresponding store opcode.
113 // (Return -1 if unknown.)
114 virtual int store_Opcode() const { return -1; }
115
116 // What is the type of the value in memory? (T_VOID mean "unspecified".)
117 virtual BasicType memory_type() const = 0;
118 virtual int memory_size() const {
119 #ifdef ASSERT
120 return type2aelembytes(memory_type(), true);
121 #else
122 return type2aelembytes(memory_type());
123 #endif
124 }
125
126 // Search through memory states which precede this node (load or store).
127 // Look for an exact match for the address, with no intervening
128 // aliased stores.
129 Node* find_previous_store(PhaseTransform* phase);
130
131 // Can this node (load or store) accurately see a stored value in
132 // the given memory state? (The state may or may not be in(Memory).)
133 Node* can_see_stored_value(Node* st, PhaseTransform* phase) const;
134
135 void set_unaligned_access() { _unaligned_access = true; }
136 bool is_unaligned_access() const { return _unaligned_access; }
137 void set_mismatched_access() { _mismatched_access = true; }
138 bool is_mismatched_access() const { return _mismatched_access; }
139
140 #ifndef PRODUCT
141 static void dump_adr_type(const Node* mem, const TypePtr* adr_type, outputStream *st);
142 virtual void dump_spec(outputStream *st) const;
143 #endif
144 };
145
146 //------------------------------LoadNode---------------------------------------
147 // Load value; requires Memory and Address
148 class LoadNode : public MemNode {
149 public:
150 // Some loads (from unsafe) should be pinned: they don't depend only
151 // on the dominating test. The boolean field _depends_only_on_test
152 // below records whether that node depends only on the dominating
153 // test.
154 // Methods used to build LoadNodes pass an argument of type enum
155 // ControlDependency instead of a boolean because those methods
156 // typically have multiple boolean parameters with default values:
157 // passing the wrong boolean to one of these parameters by mistake
158 // goes easily unnoticed. Using an enum, the compiler can check that
159 // the type of a value and the type of the parameter match.
160 enum ControlDependency {
161 Pinned,
162 DependsOnlyOnTest
163 };
164 private:
165 // LoadNode::hash() doesn't take the _depends_only_on_test field
166 // into account: If the graph already has a non-pinned LoadNode and
167 // we add a pinned LoadNode with the same inputs, it's safe for GVN
168 // to replace the pinned LoadNode with the non-pinned LoadNode,
169 // otherwise it wouldn't be safe to have a non pinned LoadNode with
170 // those inputs in the first place. If the graph already has a
171 // pinned LoadNode and we add a non pinned LoadNode with the same
172 // inputs, it's safe (but suboptimal) for GVN to replace the
173 // non-pinned LoadNode by the pinned LoadNode.
174 bool _depends_only_on_test;
175
176 // On platforms with weak memory ordering (e.g., PPC, Ia64) we distinguish
177 // loads that can be reordered, and such requiring acquire semantics to
178 // adhere to the Java specification. The required behaviour is stored in
179 // this field.
180 const MemOrd _mo;
181
182 protected:
183 virtual uint cmp(const Node &n) const;
184 virtual uint size_of() const; // Size is bigger
185 // Should LoadNode::Ideal() attempt to remove control edges?
186 virtual bool can_remove_control() const;
187 const Type* const _type; // What kind of value is loaded?
188 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
205 virtual uint hash() const; // Check the type
206
207 // Handle algebraic identities here. If we have an identity, return the Node
208 // we are equivalent to. We look for Load of a Store.
209 virtual Node *Identity( PhaseTransform *phase );
210
211 // If the load is from Field memory and the pointer is non-null, it might be possible to
212 // zero out the control input.
213 // If the offset is constant and the base is an object allocation,
214 // try to hook me up to the exact initializing store.
215 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
216
217 // Split instance field load through Phi.
218 Node* split_through_phi(PhaseGVN *phase);
219
220 // Recover original value from boxed values
221 Node *eliminate_autobox(PhaseGVN *phase);
222
223 // Compute a new Type for this node. Basically we just do the pre-check,
224 // then call the virtual add() to set the type.
225 virtual const Type *Value( PhaseTransform *phase ) const;
226
227 // Common methods for LoadKlass and LoadNKlass nodes.
228 const Type *klass_value_common( PhaseTransform *phase ) const;
229 Node *klass_identity_common( PhaseTransform *phase );
230
231 virtual uint ideal_reg() const;
232 virtual const Type *bottom_type() const;
233 // Following method is copied from TypeNode:
234 void set_type(const Type* t) {
235 assert(t != NULL, "sanity");
236 debug_only(uint check_hash = (VerifyHashTableKeys && _hash_lock) ? hash() : NO_HASH);
237 *(const Type**)&_type = t; // cast away const-ness
238 // If this node is in the hash table, make sure it doesn't need a rehash.
239 assert(check_hash == NO_HASH || check_hash == hash(), "type change must preserve hash code");
240 }
241 const Type* type() const { assert(_type != NULL, "sanity"); return _type; };
242
243 // Do not match memory edge
244 virtual uint match_edge(uint idx) const;
245
246 // Map a load opcode to its corresponding store opcode.
247 virtual int store_Opcode() const = 0;
248
249 // Check if the load's memory input is a Phi node with the same control.
250 bool is_instance_field_load_with_local_phi(Node* ctrl);
251
252 #ifndef PRODUCT
253 virtual void dump_spec(outputStream *st) const;
254 #endif
255 #ifdef ASSERT
256 // Helper function to allow a raw load without control edge for some cases
257 static bool is_immutable_value(Node* adr);
258 #endif
259 protected:
260 const Type* load_array_final_field(const TypeKlassPtr *tkls,
261 ciKlass* klass) const;
262 // depends_only_on_test is almost always true, and needs to be almost always
263 // true to enable key hoisting & commoning optimizations. However, for the
264 // special case of RawPtr loads from TLS top & end, and other loads performed by
265 // GC barriers, the control edge carries the dependence preventing hoisting past
266 // a Safepoint instead of the memory edge. (An unfortunate consequence of having
267 // Safepoints not set Raw Memory; itself an unfortunate consequence of having Nodes
268 // which produce results (new raw memory state) inside of loops preventing all
269 // manner of other optimizations). Basically, it's ugly but so is the alternative.
270 // See comment in macro.cpp, around line 125 expand_allocate_common().
271 virtual bool depends_only_on_test() const { return adr_type() != TypeRawPtr::BOTTOM && _depends_only_on_test; }
272 };
273
274 //------------------------------LoadBNode--------------------------------------
275 // Load a byte (8bits signed) from memory
276 class LoadBNode : public LoadNode {
277 public:
278 LoadBNode(Node *c, Node *mem, Node *adr, const TypePtr* at, const TypeInt *ti, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
279 : LoadNode(c, mem, adr, at, ti, mo, control_dependency) {}
280 virtual int Opcode() const;
281 virtual uint ideal_reg() const { return Op_RegI; }
282 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
283 virtual const Type *Value(PhaseTransform *phase) const;
284 virtual int store_Opcode() const { return Op_StoreB; }
285 virtual BasicType memory_type() const { return T_BYTE; }
286 };
287
288 //------------------------------LoadUBNode-------------------------------------
289 // Load a unsigned byte (8bits unsigned) from memory
290 class LoadUBNode : public LoadNode {
291 public:
292 LoadUBNode(Node* c, Node* mem, Node* adr, const TypePtr* at, const TypeInt* ti, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
293 : LoadNode(c, mem, adr, at, ti, mo, control_dependency) {}
294 virtual int Opcode() const;
295 virtual uint ideal_reg() const { return Op_RegI; }
296 virtual Node* Ideal(PhaseGVN *phase, bool can_reshape);
297 virtual const Type *Value(PhaseTransform *phase) const;
298 virtual int store_Opcode() const { return Op_StoreB; }
299 virtual BasicType memory_type() const { return T_BYTE; }
300 };
301
302 //------------------------------LoadUSNode-------------------------------------
303 // Load an unsigned short/char (16bits unsigned) from memory
304 class LoadUSNode : public LoadNode {
305 public:
306 LoadUSNode(Node *c, Node *mem, Node *adr, const TypePtr* at, const TypeInt *ti, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
307 : LoadNode(c, mem, adr, at, ti, mo, control_dependency) {}
308 virtual int Opcode() const;
309 virtual uint ideal_reg() const { return Op_RegI; }
310 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
311 virtual const Type *Value(PhaseTransform *phase) const;
312 virtual int store_Opcode() const { return Op_StoreC; }
313 virtual BasicType memory_type() const { return T_CHAR; }
314 };
315
316 //------------------------------LoadSNode--------------------------------------
317 // Load a short (16bits signed) from memory
318 class LoadSNode : public LoadNode {
319 public:
320 LoadSNode(Node *c, Node *mem, Node *adr, const TypePtr* at, const TypeInt *ti, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
321 : LoadNode(c, mem, adr, at, ti, mo, control_dependency) {}
322 virtual int Opcode() const;
323 virtual uint ideal_reg() const { return Op_RegI; }
324 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
325 virtual const Type *Value(PhaseTransform *phase) const;
326 virtual int store_Opcode() const { return Op_StoreC; }
327 virtual BasicType memory_type() const { return T_SHORT; }
328 };
329
330 //------------------------------LoadINode--------------------------------------
331 // Load an integer from memory
332 class LoadINode : public LoadNode {
333 public:
334 LoadINode(Node *c, Node *mem, Node *adr, const TypePtr* at, const TypeInt *ti, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
335 : LoadNode(c, mem, adr, at, ti, mo, control_dependency) {}
336 virtual int Opcode() const;
337 virtual uint ideal_reg() const { return Op_RegI; }
338 virtual int store_Opcode() const { return Op_StoreI; }
339 virtual BasicType memory_type() const { return T_INT; }
340 };
341
342 //------------------------------LoadRangeNode----------------------------------
343 // Load an array length from the array
344 class LoadRangeNode : public LoadINode {
345 public:
346 LoadRangeNode(Node *c, Node *mem, Node *adr, const TypeInt *ti = TypeInt::POS)
347 : LoadINode(c, mem, adr, TypeAryPtr::RANGE, ti, MemNode::unordered) {}
348 virtual int Opcode() const;
349 virtual const Type *Value( PhaseTransform *phase ) const;
350 virtual Node *Identity( PhaseTransform *phase );
351 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
352 };
353
354 //------------------------------LoadLNode--------------------------------------
355 // Load a long from memory
356 class LoadLNode : public LoadNode {
357 virtual uint hash() const { return LoadNode::hash() + _require_atomic_access; }
358 virtual uint cmp( const Node &n ) const {
359 return _require_atomic_access == ((LoadLNode&)n)._require_atomic_access
360 && LoadNode::cmp(n);
361 }
362 virtual uint size_of() const { return sizeof(*this); }
363 const bool _require_atomic_access; // is piecewise load forbidden?
364
365 public:
366 LoadLNode(Node *c, Node *mem, Node *adr, const TypePtr* at, const TypeLong *tl,
367 MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest, bool require_atomic_access = false)
368 : LoadNode(c, mem, adr, at, tl, mo, control_dependency), _require_atomic_access(require_atomic_access) {}
369 virtual int Opcode() const;
370 virtual uint ideal_reg() const { return Op_RegL; }
371 virtual int store_Opcode() const { return Op_StoreL; }
372 virtual BasicType memory_type() const { return T_LONG; }
373 bool require_atomic_access() const { return _require_atomic_access; }
374 static LoadLNode* make_atomic(Compile *C, Node* ctl, Node* mem, Node* adr, const TypePtr* adr_type,
375 const Type* rt, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest);
376 #ifndef PRODUCT
377 virtual void dump_spec(outputStream *st) const {
378 LoadNode::dump_spec(st);
379 if (_require_atomic_access) st->print(" Atomic!");
380 }
381 #endif
382 };
383
384 //------------------------------LoadL_unalignedNode----------------------------
385 // Load a long from unaligned memory
386 class LoadL_unalignedNode : public LoadLNode {
387 public:
388 LoadL_unalignedNode(Node *c, Node *mem, Node *adr, const TypePtr* at, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
389 : LoadLNode(c, mem, adr, at, TypeLong::LONG, mo, control_dependency) {}
390 virtual int Opcode() const;
391 };
392
393 //------------------------------LoadFNode--------------------------------------
394 // Load a float (64 bits) from memory
395 class LoadFNode : public LoadNode {
396 public:
397 LoadFNode(Node *c, Node *mem, Node *adr, const TypePtr* at, const Type *t, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
398 : LoadNode(c, mem, adr, at, t, mo, control_dependency) {}
399 virtual int Opcode() const;
400 virtual uint ideal_reg() const { return Op_RegF; }
401 virtual int store_Opcode() const { return Op_StoreF; }
402 virtual BasicType memory_type() const { return T_FLOAT; }
403 };
404
405 //------------------------------LoadDNode--------------------------------------
406 // Load a double (64 bits) from memory
407 class LoadDNode : public LoadNode {
408 virtual uint hash() const { return LoadNode::hash() + _require_atomic_access; }
409 virtual uint cmp( const Node &n ) const {
410 return _require_atomic_access == ((LoadDNode&)n)._require_atomic_access
411 && LoadNode::cmp(n);
412 }
413 virtual uint size_of() const { return sizeof(*this); }
414 const bool _require_atomic_access; // is piecewise load forbidden?
415
416 public:
417 LoadDNode(Node *c, Node *mem, Node *adr, const TypePtr* at, const Type *t,
418 MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest, bool require_atomic_access = false)
419 : LoadNode(c, mem, adr, at, t, mo, control_dependency), _require_atomic_access(require_atomic_access) {}
420 virtual int Opcode() const;
421 virtual uint ideal_reg() const { return Op_RegD; }
422 virtual int store_Opcode() const { return Op_StoreD; }
423 virtual BasicType memory_type() const { return T_DOUBLE; }
424 bool require_atomic_access() const { return _require_atomic_access; }
425 static LoadDNode* make_atomic(Compile *C, Node* ctl, Node* mem, Node* adr, const TypePtr* adr_type,
426 const Type* rt, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest);
427 #ifndef PRODUCT
428 virtual void dump_spec(outputStream *st) const {
429 LoadNode::dump_spec(st);
430 if (_require_atomic_access) st->print(" Atomic!");
431 }
432 #endif
433 };
434
435 //------------------------------LoadD_unalignedNode----------------------------
436 // Load a double from unaligned memory
437 class LoadD_unalignedNode : public LoadDNode {
438 public:
439 LoadD_unalignedNode(Node *c, Node *mem, Node *adr, const TypePtr* at, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
440 : LoadDNode(c, mem, adr, at, Type::DOUBLE, mo, control_dependency) {}
441 virtual int Opcode() const;
442 };
443
444 //------------------------------LoadPNode--------------------------------------
445 // Load a pointer from memory (either object or array)
446 class LoadPNode : public LoadNode {
447 public:
448 LoadPNode(Node *c, Node *mem, Node *adr, const TypePtr *at, const TypePtr* t, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
449 : LoadNode(c, mem, adr, at, t, mo, control_dependency) {}
450 virtual int Opcode() const;
451 virtual uint ideal_reg() const { return Op_RegP; }
452 virtual int store_Opcode() const { return Op_StoreP; }
453 virtual BasicType memory_type() const { return T_ADDRESS; }
454 };
455
456
457 //------------------------------LoadNNode--------------------------------------
458 // Load a narrow oop from memory (either object or array)
459 class LoadNNode : public LoadNode {
460 public:
461 LoadNNode(Node *c, Node *mem, Node *adr, const TypePtr *at, const Type* t, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
462 : LoadNode(c, mem, adr, at, t, mo, control_dependency) {}
463 virtual int Opcode() const;
464 virtual uint ideal_reg() const { return Op_RegN; }
465 virtual int store_Opcode() const { return Op_StoreN; }
466 virtual BasicType memory_type() const { return T_NARROWOOP; }
467 };
468
469 //------------------------------LoadKlassNode----------------------------------
470 // Load a Klass from an object
471 class LoadKlassNode : public LoadPNode {
472 protected:
473 // In most cases, LoadKlassNode does not have the control input set. If the control
474 // input is set, it must not be removed (by LoadNode::Ideal()).
475 virtual bool can_remove_control() const;
476 public:
477 LoadKlassNode(Node *c, Node *mem, Node *adr, const TypePtr *at, const TypeKlassPtr *tk, MemOrd mo)
478 : LoadPNode(c, mem, adr, at, tk, mo) {}
479 virtual int Opcode() const;
480 virtual const Type *Value( PhaseTransform *phase ) const;
481 virtual Node *Identity( PhaseTransform *phase );
482 virtual bool depends_only_on_test() const { return true; }
483
484 // Polymorphic factory method:
485 static Node* make(PhaseGVN& gvn, Node* ctl, Node* mem, Node* adr, const TypePtr* at,
486 const TypeKlassPtr* tk = TypeKlassPtr::OBJECT);
487 };
488
489 //------------------------------LoadNKlassNode---------------------------------
490 // Load a narrow Klass from an object.
491 class LoadNKlassNode : public LoadNNode {
492 public:
493 LoadNKlassNode(Node *c, Node *mem, Node *adr, const TypePtr *at, const TypeNarrowKlass *tk, MemOrd mo)
494 : LoadNNode(c, mem, adr, at, tk, mo) {}
495 virtual int Opcode() const;
496 virtual uint ideal_reg() const { return Op_RegN; }
497 virtual int store_Opcode() const { return Op_StoreNKlass; }
498 virtual BasicType memory_type() const { return T_NARROWKLASS; }
499
500 virtual const Type *Value( PhaseTransform *phase ) const;
501 virtual Node *Identity( PhaseTransform *phase );
502 virtual bool depends_only_on_test() const { return true; }
503 };
504
505
506 //------------------------------StoreNode--------------------------------------
507 // Store value; requires Store, Address and Value
508 class StoreNode : public MemNode {
509 private:
510 // On platforms with weak memory ordering (e.g., PPC, Ia64) we distinguish
511 // stores that can be reordered, and such requiring release semantics to
512 // adhere to the Java specification. The required behaviour is stored in
513 // this field.
514 const MemOrd _mo;
515 // Needed for proper cloning.
516 virtual uint size_of() const { return sizeof(*this); }
517 protected:
518 virtual uint cmp( const Node &n ) const;
519 virtual bool depends_only_on_test() const { return false; }
520
521 Node *Ideal_masked_input (PhaseGVN *phase, uint mask);
522 Node *Ideal_sign_extended_input(PhaseGVN *phase, int num_bits);
523
524 public:
525 // We must ensure that stores of object references will be visible
526 // only after the object's initialization. So the callers of this
527 // procedure must indicate that the store requires `release'
528 // semantics, if the stored value is an object reference that might
529 // point to a new object and may become externally visible.
530 StoreNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, MemOrd mo)
531 : MemNode(c, mem, adr, at, val), _mo(mo) {
532 init_class_id(Class_Store);
533 }
534 StoreNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, Node *oop_store, MemOrd mo)
535 : MemNode(c, mem, adr, at, val, oop_store), _mo(mo) {
536 init_class_id(Class_Store);
537 }
538
539 inline bool is_unordered() const { return !is_release(); }
540 inline bool is_release() const {
541 assert((_mo == unordered || _mo == release), "unexpected");
542 return _mo == release;
543 }
544
545 // Conservatively release stores of object references in order to
546 // ensure visibility of object initialization.
547 static inline MemOrd release_if_reference(const BasicType t) {
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 }
553
554 // Polymorphic factory method
555 //
556 // We must ensure that stores of object references will be visible
557 // only after the object's initialization. So the callers of this
558 // procedure must indicate that the store requires `release'
559 // semantics, if the stored value is an object reference that might
560 // point to a new object and may become externally visible.
561 static StoreNode* make(PhaseGVN& gvn, Node *c, Node *mem, Node *adr,
562 const TypePtr* at, Node *val, BasicType bt, MemOrd mo);
563
564 virtual uint hash() const; // Check the type
565
566 // If the store is to Field memory and the pointer is non-null, we can
567 // zero out the control input.
568 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
569
570 // Compute a new Type for this node. Basically we just do the pre-check,
571 // then call the virtual add() to set the type.
572 virtual const Type *Value( PhaseTransform *phase ) const;
573
574 // Check for identity function on memory (Load then Store at same address)
575 virtual Node *Identity( PhaseTransform *phase );
576
577 // Do not match memory edge
578 virtual uint match_edge(uint idx) const;
579
580 virtual const Type *bottom_type() const; // returns Type::MEMORY
581
582 // Map a store opcode to its corresponding own opcode, trivially.
583 virtual int store_Opcode() const { return Opcode(); }
584
585 // have all possible loads of the value stored been optimized away?
586 bool value_never_loaded(PhaseTransform *phase) const;
587 };
588
589 //------------------------------StoreBNode-------------------------------------
590 // Store byte to memory
591 class StoreBNode : public StoreNode {
592 public:
593 StoreBNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, MemOrd mo)
594 : StoreNode(c, mem, adr, at, val, mo) {}
595 virtual int Opcode() const;
596 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
597 virtual BasicType memory_type() const { return T_BYTE; }
598 };
599
600 //------------------------------StoreCNode-------------------------------------
601 // Store char/short to memory
602 class StoreCNode : public StoreNode {
603 public:
604 StoreCNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, MemOrd mo)
605 : StoreNode(c, mem, adr, at, val, mo) {}
606 virtual int Opcode() const;
607 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
608 virtual BasicType memory_type() const { return T_CHAR; }
609 };
610
611 //------------------------------StoreINode-------------------------------------
612 // Store int to memory
613 class StoreINode : public StoreNode {
614 public:
615 StoreINode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, MemOrd mo)
616 : StoreNode(c, mem, adr, at, val, mo) {}
617 virtual int Opcode() const;
618 virtual BasicType memory_type() const { return T_INT; }
619 };
620
621 //------------------------------StoreLNode-------------------------------------
622 // Store long to memory
623 class StoreLNode : public StoreNode {
624 virtual uint hash() const { return StoreNode::hash() + _require_atomic_access; }
625 virtual uint cmp( const Node &n ) const {
626 return _require_atomic_access == ((StoreLNode&)n)._require_atomic_access
627 && StoreNode::cmp(n);
628 }
629 virtual uint size_of() const { return sizeof(*this); }
630 const bool _require_atomic_access; // is piecewise store forbidden?
631
632 public:
633 StoreLNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, MemOrd mo, bool require_atomic_access = false)
634 : StoreNode(c, mem, adr, at, val, mo), _require_atomic_access(require_atomic_access) {}
635 virtual int Opcode() const;
636 virtual BasicType memory_type() const { return T_LONG; }
637 bool require_atomic_access() const { return _require_atomic_access; }
638 static StoreLNode* make_atomic(Compile *C, Node* ctl, Node* mem, Node* adr, const TypePtr* adr_type, Node* val, MemOrd mo);
639 #ifndef PRODUCT
640 virtual void dump_spec(outputStream *st) const {
641 StoreNode::dump_spec(st);
642 if (_require_atomic_access) st->print(" Atomic!");
643 }
644 #endif
645 };
646
647 //------------------------------StoreFNode-------------------------------------
648 // Store float to memory
649 class StoreFNode : public StoreNode {
650 public:
651 StoreFNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, MemOrd mo)
652 : StoreNode(c, mem, adr, at, val, mo) {}
653 virtual int Opcode() const;
654 virtual BasicType memory_type() const { return T_FLOAT; }
655 };
656
657 //------------------------------StoreDNode-------------------------------------
658 // Store double to memory
659 class StoreDNode : public StoreNode {
660 virtual uint hash() const { return StoreNode::hash() + _require_atomic_access; }
661 virtual uint cmp( const Node &n ) const {
662 return _require_atomic_access == ((StoreDNode&)n)._require_atomic_access
663 && StoreNode::cmp(n);
664 }
665 virtual uint size_of() const { return sizeof(*this); }
666 const bool _require_atomic_access; // is piecewise store forbidden?
667 public:
668 StoreDNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val,
669 MemOrd mo, bool require_atomic_access = false)
670 : StoreNode(c, mem, adr, at, val, mo), _require_atomic_access(require_atomic_access) {}
671 virtual int Opcode() const;
672 virtual BasicType memory_type() const { return T_DOUBLE; }
673 bool require_atomic_access() const { return _require_atomic_access; }
674 static StoreDNode* make_atomic(Compile *C, Node* ctl, Node* mem, Node* adr, const TypePtr* adr_type, Node* val, MemOrd mo);
675 #ifndef PRODUCT
676 virtual void dump_spec(outputStream *st) const {
677 StoreNode::dump_spec(st);
678 if (_require_atomic_access) st->print(" Atomic!");
679 }
680 #endif
681
682 };
683
684 //------------------------------StorePNode-------------------------------------
685 // Store pointer to memory
686 class StorePNode : public StoreNode {
687 public:
688 StorePNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, MemOrd mo)
689 : StoreNode(c, mem, adr, at, val, mo) {}
690 virtual int Opcode() const;
691 virtual BasicType memory_type() const { return T_ADDRESS; }
692 };
693
694 //------------------------------StoreNNode-------------------------------------
695 // Store narrow oop to memory
696 class StoreNNode : public StoreNode {
697 public:
698 StoreNNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, MemOrd mo)
699 : StoreNode(c, mem, adr, at, val, mo) {}
700 virtual int Opcode() const;
701 virtual BasicType memory_type() const { return T_NARROWOOP; }
702 };
703
704 //------------------------------StoreNKlassNode--------------------------------------
705 // Store narrow klass to memory
706 class StoreNKlassNode : public StoreNNode {
707 public:
708 StoreNKlassNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, MemOrd mo)
709 : StoreNNode(c, mem, adr, at, val, mo) {}
710 virtual int Opcode() const;
711 virtual BasicType memory_type() const { return T_NARROWKLASS; }
712 };
713
714 //------------------------------StoreCMNode-----------------------------------
715 // Store card-mark byte to memory for CM
716 // The last StoreCM before a SafePoint must be preserved and occur after its "oop" store
717 // Preceeding equivalent StoreCMs may be eliminated.
718 class StoreCMNode : public StoreNode {
719 private:
720 virtual uint hash() const { return StoreNode::hash() + _oop_alias_idx; }
721 virtual uint cmp( const Node &n ) const {
722 return _oop_alias_idx == ((StoreCMNode&)n)._oop_alias_idx
723 && StoreNode::cmp(n);
724 }
725 virtual uint size_of() const { return sizeof(*this); }
726 int _oop_alias_idx; // The alias_idx of OopStore
727
728 public:
729 StoreCMNode( Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, Node *oop_store, int oop_alias_idx ) :
730 StoreNode(c, mem, adr, at, val, oop_store, MemNode::release),
731 _oop_alias_idx(oop_alias_idx) {
732 assert(_oop_alias_idx >= Compile::AliasIdxRaw ||
733 _oop_alias_idx == Compile::AliasIdxBot && Compile::current()->AliasLevel() == 0,
734 "bad oop alias idx");
735 }
736 virtual int Opcode() const;
737 virtual Node *Identity( PhaseTransform *phase );
738 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
739 virtual const Type *Value( PhaseTransform *phase ) const;
740 virtual BasicType memory_type() const { return T_VOID; } // unspecific
741 int oop_alias_idx() const { return _oop_alias_idx; }
742 };
743
744 //------------------------------LoadPLockedNode---------------------------------
745 // Load-locked a pointer from memory (either object or array).
746 // On Sparc & Intel this is implemented as a normal pointer load.
747 // On PowerPC and friends it's a real load-locked.
748 class LoadPLockedNode : public LoadPNode {
749 public:
750 LoadPLockedNode(Node *c, Node *mem, Node *adr, MemOrd mo)
751 : LoadPNode(c, mem, adr, TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM, mo) {}
752 virtual int Opcode() const;
753 virtual int store_Opcode() const { return Op_StorePConditional; }
754 virtual bool depends_only_on_test() const { return true; }
755 };
756
757 //------------------------------SCMemProjNode---------------------------------------
758 // This class defines a projection of the memory state of a store conditional node.
759 // These nodes return a value, but also update memory.
760 class SCMemProjNode : public ProjNode {
761 public:
762 enum {SCMEMPROJCON = (uint)-2};
763 SCMemProjNode( Node *src) : ProjNode( src, SCMEMPROJCON) { }
764 virtual int Opcode() const;
765 virtual bool is_CFG() const { return false; }
766 virtual const Type *bottom_type() const {return Type::MEMORY;}
767 virtual const TypePtr *adr_type() const { return in(0)->in(MemNode::Memory)->adr_type();}
768 virtual uint ideal_reg() const { return 0;} // memory projections don't have a register
769 virtual const Type *Value( PhaseTransform *phase ) const;
770 #ifndef PRODUCT
771 virtual void dump_spec(outputStream *st) const {};
772 #endif
773 };
774
775 //------------------------------LoadStoreNode---------------------------
776 // Note: is_Mem() method returns 'true' for this class.
777 class LoadStoreNode : public Node {
778 private:
779 const Type* const _type; // What kind of value is loaded?
780 const TypePtr* _adr_type; // What kind of memory is being addressed?
781 virtual uint size_of() const; // Size is bigger
782 public:
783 LoadStoreNode( Node *c, Node *mem, Node *adr, Node *val, const TypePtr* at, const Type* rt, uint required );
784 virtual bool depends_only_on_test() const { return false; }
785 virtual uint match_edge(uint idx) const { return idx == MemNode::Address || idx == MemNode::ValueIn; }
786
787 virtual const Type *bottom_type() const { return _type; }
788 virtual uint ideal_reg() const;
789 virtual const class TypePtr *adr_type() const { return _adr_type; } // returns bottom_type of address
790
791 bool result_not_used() const;
792 };
793
794 class LoadStoreConditionalNode : public LoadStoreNode {
795 public:
796 enum {
797 ExpectedIn = MemNode::ValueIn+1 // One more input than MemNode
798 };
799 LoadStoreConditionalNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex);
800 };
801
802 //------------------------------StorePConditionalNode---------------------------
803 // Conditionally store pointer to memory, if no change since prior
804 // load-locked. Sets flags for success or failure of the store.
805 class StorePConditionalNode : public LoadStoreConditionalNode {
806 public:
807 StorePConditionalNode( Node *c, Node *mem, Node *adr, Node *val, Node *ll ) : LoadStoreConditionalNode(c, mem, adr, val, ll) { }
808 virtual int Opcode() const;
809 // Produces flags
810 virtual uint ideal_reg() const { return Op_RegFlags; }
811 };
812
813 //------------------------------StoreIConditionalNode---------------------------
814 // Conditionally store int to memory, if no change since prior
815 // load-locked. Sets flags for success or failure of the store.
816 class StoreIConditionalNode : public LoadStoreConditionalNode {
817 public:
818 StoreIConditionalNode( Node *c, Node *mem, Node *adr, Node *val, Node *ii ) : LoadStoreConditionalNode(c, mem, adr, val, ii) { }
819 virtual int Opcode() const;
820 // Produces flags
821 virtual uint ideal_reg() const { return Op_RegFlags; }
822 };
823
824 //------------------------------StoreLConditionalNode---------------------------
825 // Conditionally store long to memory, if no change since prior
826 // load-locked. Sets flags for success or failure of the store.
827 class StoreLConditionalNode : public LoadStoreConditionalNode {
828 public:
829 StoreLConditionalNode( Node *c, Node *mem, Node *adr, Node *val, Node *ll ) : LoadStoreConditionalNode(c, mem, adr, val, ll) { }
830 virtual int Opcode() const;
831 // Produces flags
832 virtual uint ideal_reg() const { return Op_RegFlags; }
833 };
834
835
836 //------------------------------CompareAndSwapLNode---------------------------
837 class CompareAndSwapLNode : public LoadStoreConditionalNode {
838 public:
839 CompareAndSwapLNode( Node *c, Node *mem, Node *adr, Node *val, Node *ex) : LoadStoreConditionalNode(c, mem, adr, val, ex) { }
840 virtual int Opcode() const;
841 };
842
843
844 //------------------------------CompareAndSwapINode---------------------------
845 class CompareAndSwapINode : public LoadStoreConditionalNode {
846 public:
847 CompareAndSwapINode( Node *c, Node *mem, Node *adr, Node *val, Node *ex) : LoadStoreConditionalNode(c, mem, adr, val, ex) { }
848 virtual int Opcode() const;
849 };
850
851
852 //------------------------------CompareAndSwapPNode---------------------------
853 class CompareAndSwapPNode : public LoadStoreConditionalNode {
854 public:
855 CompareAndSwapPNode( Node *c, Node *mem, Node *adr, Node *val, Node *ex) : LoadStoreConditionalNode(c, mem, adr, val, ex) { }
856 virtual int Opcode() const;
857 };
858
859 //------------------------------CompareAndSwapNNode---------------------------
860 class CompareAndSwapNNode : public LoadStoreConditionalNode {
861 public:
862 CompareAndSwapNNode( Node *c, Node *mem, Node *adr, Node *val, Node *ex) : LoadStoreConditionalNode(c, mem, adr, val, ex) { }
863 virtual int Opcode() const;
864 };
865
866 //------------------------------GetAndAddINode---------------------------
867 class GetAndAddINode : public LoadStoreNode {
868 public:
869 GetAndAddINode( Node *c, Node *mem, Node *adr, Node *val, const TypePtr* at ) : LoadStoreNode(c, mem, adr, val, at, TypeInt::INT, 4) { }
870 virtual int Opcode() const;
871 };
872
873 //------------------------------GetAndAddLNode---------------------------
874 class GetAndAddLNode : public LoadStoreNode {
875 public:
876 GetAndAddLNode( Node *c, Node *mem, Node *adr, Node *val, const TypePtr* at ) : LoadStoreNode(c, mem, adr, val, at, TypeLong::LONG, 4) { }
877 virtual int Opcode() const;
878 };
879
880
881 //------------------------------GetAndSetINode---------------------------
882 class GetAndSetINode : public LoadStoreNode {
883 public:
884 GetAndSetINode( Node *c, Node *mem, Node *adr, Node *val, const TypePtr* at ) : LoadStoreNode(c, mem, adr, val, at, TypeInt::INT, 4) { }
885 virtual int Opcode() const;
886 };
887
888 //------------------------------GetAndSetINode---------------------------
889 class GetAndSetLNode : public LoadStoreNode {
890 public:
891 GetAndSetLNode( Node *c, Node *mem, Node *adr, Node *val, const TypePtr* at ) : LoadStoreNode(c, mem, adr, val, at, TypeLong::LONG, 4) { }
892 virtual int Opcode() const;
893 };
894
895 //------------------------------GetAndSetPNode---------------------------
896 class GetAndSetPNode : public LoadStoreNode {
897 public:
898 GetAndSetPNode( Node *c, Node *mem, Node *adr, Node *val, const TypePtr* at, const Type* t ) : LoadStoreNode(c, mem, adr, val, at, t, 4) { }
899 virtual int Opcode() const;
900 };
901
902 //------------------------------GetAndSetNNode---------------------------
903 class GetAndSetNNode : public LoadStoreNode {
904 public:
905 GetAndSetNNode( Node *c, Node *mem, Node *adr, Node *val, const TypePtr* at, const Type* t ) : LoadStoreNode(c, mem, adr, val, at, t, 4) { }
906 virtual int Opcode() const;
907 };
908
909 //------------------------------ClearArray-------------------------------------
910 class ClearArrayNode: public Node {
911 public:
912 ClearArrayNode( Node *ctrl, Node *arymem, Node *word_cnt, Node *base )
913 : Node(ctrl,arymem,word_cnt,base) {
914 init_class_id(Class_ClearArray);
915 }
916 virtual int Opcode() const;
917 virtual const Type *bottom_type() const { return Type::MEMORY; }
918 // ClearArray modifies array elements, and so affects only the
919 // array memory addressed by the bottom_type of its base address.
920 virtual const class TypePtr *adr_type() const;
921 virtual Node *Identity( PhaseTransform *phase );
922 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
923 virtual uint match_edge(uint idx) const;
924
925 // Clear the given area of an object or array.
926 // The start offset must always be aligned mod BytesPerInt.
927 // The end offset must always be aligned mod BytesPerLong.
928 // Return the new memory.
929 static Node* clear_memory(Node* control, Node* mem, Node* dest,
930 intptr_t start_offset,
931 intptr_t end_offset,
932 PhaseGVN* phase);
933 static Node* clear_memory(Node* control, Node* mem, Node* dest,
934 intptr_t start_offset,
935 Node* end_offset,
936 PhaseGVN* phase);
937 static Node* clear_memory(Node* control, Node* mem, Node* dest,
938 Node* start_offset,
939 Node* end_offset,
940 PhaseGVN* phase);
941 // Return allocation input memory edge if it is different instance
942 // or itself if it is the one we are looking for.
943 static bool step_through(Node** np, uint instance_id, PhaseTransform* phase);
944 };
945
946 //------------------------------StrIntrinsic-------------------------------
947 // Base class for Ideal nodes used in String instrinsic code.
948 class StrIntrinsicNode: public Node {
949 public:
950 StrIntrinsicNode(Node* control, Node* char_array_mem,
951 Node* s1, Node* c1, Node* s2, Node* c2):
952 Node(control, char_array_mem, s1, c1, s2, c2) {
953 }
954
955 StrIntrinsicNode(Node* control, Node* char_array_mem,
956 Node* s1, Node* s2, Node* c):
957 Node(control, char_array_mem, s1, s2, c) {
958 }
959
960 StrIntrinsicNode(Node* control, Node* char_array_mem,
961 Node* s1, Node* s2):
962 Node(control, char_array_mem, s1, s2) {
963 }
964
965 virtual bool depends_only_on_test() const { return false; }
966 virtual const TypePtr* adr_type() const { return TypeAryPtr::CHARS; }
967 virtual uint match_edge(uint idx) const;
968 virtual uint ideal_reg() const { return Op_RegI; }
969 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
970 virtual const Type *Value(PhaseTransform *phase) const;
971 };
972
973 //------------------------------StrComp-------------------------------------
974 class StrCompNode: public StrIntrinsicNode {
975 public:
976 StrCompNode(Node* control, Node* char_array_mem,
977 Node* s1, Node* c1, Node* s2, Node* c2):
978 StrIntrinsicNode(control, char_array_mem, s1, c1, s2, c2) {};
979 virtual int Opcode() const;
980 virtual const Type* bottom_type() const { return TypeInt::INT; }
981 };
982
983 //------------------------------StrEquals-------------------------------------
984 class StrEqualsNode: public StrIntrinsicNode {
985 public:
986 StrEqualsNode(Node* control, Node* char_array_mem,
987 Node* s1, Node* s2, Node* c):
988 StrIntrinsicNode(control, char_array_mem, s1, s2, c) {};
989 virtual int Opcode() const;
990 virtual const Type* bottom_type() const { return TypeInt::BOOL; }
991 };
992
993 //------------------------------StrIndexOf-------------------------------------
994 class StrIndexOfNode: public StrIntrinsicNode {
995 public:
996 StrIndexOfNode(Node* control, Node* char_array_mem,
997 Node* s1, Node* c1, Node* s2, Node* c2):
998 StrIntrinsicNode(control, char_array_mem, s1, c1, s2, c2) {};
999 virtual int Opcode() const;
1000 virtual const Type* bottom_type() const { return TypeInt::INT; }
1001 };
1002
1003 //------------------------------AryEq---------------------------------------
1004 class AryEqNode: public StrIntrinsicNode {
1005 public:
1006 AryEqNode(Node* control, Node* char_array_mem, Node* s1, Node* s2):
1007 StrIntrinsicNode(control, char_array_mem, s1, s2) {};
1008 virtual int Opcode() const;
1009 virtual const Type* bottom_type() const { return TypeInt::BOOL; }
1010 };
1011
1012
1013 //------------------------------EncodeISOArray--------------------------------
1014 // encode char[] to byte[] in ISO_8859_1
1015 class EncodeISOArrayNode: public Node {
1016 public:
1017 EncodeISOArrayNode(Node *control, Node* arymem, Node* s1, Node* s2, Node* c): Node(control, arymem, s1, s2, c) {};
1018 virtual int Opcode() const;
1019 virtual bool depends_only_on_test() const { return false; }
1020 virtual const Type* bottom_type() const { return TypeInt::INT; }
1021 virtual const TypePtr* adr_type() const { return TypePtr::BOTTOM; }
1022 virtual uint match_edge(uint idx) const;
1023 virtual uint ideal_reg() const { return Op_RegI; }
1024 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
1025 virtual const Type *Value(PhaseTransform *phase) const;
1026 };
1027
1028 //------------------------------MemBar-----------------------------------------
1029 // There are different flavors of Memory Barriers to match the Java Memory
1030 // Model. Monitor-enter and volatile-load act as Aquires: no following ref
1031 // can be moved to before them. We insert a MemBar-Acquire after a FastLock or
1032 // volatile-load. Monitor-exit and volatile-store act as Release: no
1033 // preceding ref can be moved to after them. We insert a MemBar-Release
1034 // before a FastUnlock or volatile-store. All volatiles need to be
1035 // serialized, so we follow all volatile-stores with a MemBar-Volatile to
1036 // separate it from any following volatile-load.
1037 class MemBarNode: public MultiNode {
1038 virtual uint hash() const ; // { return NO_HASH; }
1039 virtual uint cmp( const Node &n ) const ; // Always fail, except on self
1040
1041 virtual uint size_of() const { return sizeof(*this); }
1042 // Memory type this node is serializing. Usually either rawptr or bottom.
1043 const TypePtr* _adr_type;
1044
1045 public:
1046 enum {
1047 Precedent = TypeFunc::Parms // optional edge to force precedence
1048 };
1049 MemBarNode(Compile* C, int alias_idx, Node* precedent);
1050 virtual int Opcode() const = 0;
1051 virtual const class TypePtr *adr_type() const { return _adr_type; }
1052 virtual const Type *Value( PhaseTransform *phase ) const;
1053 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
1054 virtual uint match_edge(uint idx) const { return 0; }
1055 virtual const Type *bottom_type() const { return TypeTuple::MEMBAR; }
1056 virtual Node *match( const ProjNode *proj, const Matcher *m );
1057 // Factory method. Builds a wide or narrow membar.
1058 // Optional 'precedent' becomes an extra edge if not null.
1059 static MemBarNode* make(Compile* C, int opcode,
1060 int alias_idx = Compile::AliasIdxBot,
1061 Node* precedent = NULL);
1062 };
1063
1064 // "Acquire" - no following ref can move before (but earlier refs can
1065 // follow, like an early Load stalled in cache). Requires multi-cpu
1066 // visibility. Inserted after a volatile load.
1067 class MemBarAcquireNode: public MemBarNode {
1068 public:
1069 MemBarAcquireNode(Compile* C, int alias_idx, Node* precedent)
1070 : MemBarNode(C, alias_idx, precedent) {}
1071 virtual int Opcode() const;
1072 };
1073
1074 // "Acquire" - no following ref can move before (but earlier refs can
1075 // follow, like an early Load stalled in cache). Requires multi-cpu
1076 // visibility. Inserted independ of any load, as required
1077 // for intrinsic sun.misc.Unsafe.loadFence().
1078 class LoadFenceNode: public MemBarNode {
1079 public:
1080 LoadFenceNode(Compile* C, int alias_idx, Node* precedent)
1081 : MemBarNode(C, alias_idx, precedent) {}
1082 virtual int Opcode() const;
1083 };
1084
1085 // "Release" - no earlier ref can move after (but later refs can move
1086 // up, like a speculative pipelined cache-hitting Load). Requires
1087 // multi-cpu visibility. Inserted before a volatile store.
1088 class MemBarReleaseNode: public MemBarNode {
1089 public:
1090 MemBarReleaseNode(Compile* C, int alias_idx, Node* precedent)
1091 : MemBarNode(C, alias_idx, precedent) {}
1092 virtual int Opcode() const;
1093 };
1094
1095 // "Release" - no earlier ref can move after (but later refs can move
1096 // up, like a speculative pipelined cache-hitting Load). Requires
1097 // multi-cpu visibility. Inserted independent of any store, as required
1098 // for intrinsic sun.misc.Unsafe.storeFence().
1099 class StoreFenceNode: public MemBarNode {
1100 public:
1101 StoreFenceNode(Compile* C, int alias_idx, Node* precedent)
1102 : MemBarNode(C, alias_idx, precedent) {}
1103 virtual int Opcode() const;
1104 };
1105
1106 // "Acquire" - no following ref can move before (but earlier refs can
1107 // follow, like an early Load stalled in cache). Requires multi-cpu
1108 // visibility. Inserted after a FastLock.
1109 class MemBarAcquireLockNode: public MemBarNode {
1110 public:
1111 MemBarAcquireLockNode(Compile* C, int alias_idx, Node* precedent)
1112 : MemBarNode(C, alias_idx, precedent) {}
1113 virtual int Opcode() const;
1114 };
1115
1116 // "Release" - no earlier ref can move after (but later refs can move
1117 // up, like a speculative pipelined cache-hitting Load). Requires
1118 // multi-cpu visibility. Inserted before a FastUnLock.
1119 class MemBarReleaseLockNode: public MemBarNode {
1120 public:
1121 MemBarReleaseLockNode(Compile* C, int alias_idx, Node* precedent)
1122 : MemBarNode(C, alias_idx, precedent) {}
1123 virtual int Opcode() const;
1124 };
1125
1126 class MemBarStoreStoreNode: public MemBarNode {
1127 public:
1128 MemBarStoreStoreNode(Compile* C, int alias_idx, Node* precedent)
1129 : MemBarNode(C, alias_idx, precedent) {
1130 init_class_id(Class_MemBarStoreStore);
1131 }
1132 virtual int Opcode() const;
1133 };
1134
1135 // Ordering between a volatile store and a following volatile load.
1136 // Requires multi-CPU visibility?
1137 class MemBarVolatileNode: public MemBarNode {
1138 public:
1139 MemBarVolatileNode(Compile* C, int alias_idx, Node* precedent)
1140 : MemBarNode(C, alias_idx, precedent) {}
1141 virtual int Opcode() const;
1142 };
1143
1144 // Ordering within the same CPU. Used to order unsafe memory references
1145 // inside the compiler when we lack alias info. Not needed "outside" the
1146 // compiler because the CPU does all the ordering for us.
1147 class MemBarCPUOrderNode: public MemBarNode {
1148 public:
1149 MemBarCPUOrderNode(Compile* C, int alias_idx, Node* precedent)
1150 : MemBarNode(C, alias_idx, precedent) {}
1151 virtual int Opcode() const;
1152 virtual uint ideal_reg() const { return 0; } // not matched in the AD file
1153 };
1154
1155 // Isolation of object setup after an AllocateNode and before next safepoint.
1156 // (See comment in memnode.cpp near InitializeNode::InitializeNode for semantics.)
1157 class InitializeNode: public MemBarNode {
1158 friend class AllocateNode;
1159
1160 enum {
1161 Incomplete = 0,
1162 Complete = 1,
1163 WithArraycopy = 2
1164 };
1165 int _is_complete;
1166
1167 bool _does_not_escape;
1168
1169 public:
1170 enum {
1171 Control = TypeFunc::Control,
1172 Memory = TypeFunc::Memory, // MergeMem for states affected by this op
1173 RawAddress = TypeFunc::Parms+0, // the newly-allocated raw address
1174 RawStores = TypeFunc::Parms+1 // zero or more stores (or TOP)
1175 };
1176
1177 InitializeNode(Compile* C, int adr_type, Node* rawoop);
1178 virtual int Opcode() const;
1179 virtual uint size_of() const { return sizeof(*this); }
1180 virtual uint ideal_reg() const { return 0; } // not matched in the AD file
1181 virtual const RegMask &in_RegMask(uint) const; // mask for RawAddress
1182
1183 // Manage incoming memory edges via a MergeMem on in(Memory):
1184 Node* memory(uint alias_idx);
1185
1186 // The raw memory edge coming directly from the Allocation.
1187 // The contents of this memory are *always* all-zero-bits.
1188 Node* zero_memory() { return memory(Compile::AliasIdxRaw); }
1189
1190 // Return the corresponding allocation for this initialization (or null if none).
1191 // (Note: Both InitializeNode::allocation and AllocateNode::initialization
1192 // are defined in graphKit.cpp, which sets up the bidirectional relation.)
1193 AllocateNode* allocation();
1194
1195 // Anything other than zeroing in this init?
1196 bool is_non_zero();
1197
1198 // An InitializeNode must completed before macro expansion is done.
1199 // Completion requires that the AllocateNode must be followed by
1200 // initialization of the new memory to zero, then to any initializers.
1201 bool is_complete() { return _is_complete != Incomplete; }
1202 bool is_complete_with_arraycopy() { return (_is_complete & WithArraycopy) != 0; }
1203
1204 // Mark complete. (Must not yet be complete.)
1205 void set_complete(PhaseGVN* phase);
1206 void set_complete_with_arraycopy() { _is_complete = Complete | WithArraycopy; }
1207
1208 bool does_not_escape() { return _does_not_escape; }
1209 void set_does_not_escape() { _does_not_escape = true; }
1210
1211 #ifdef ASSERT
1212 // ensure all non-degenerate stores are ordered and non-overlapping
1213 bool stores_are_sane(PhaseTransform* phase);
1214 #endif //ASSERT
1215
1216 // See if this store can be captured; return offset where it initializes.
1217 // Return 0 if the store cannot be moved (any sort of problem).
1218 intptr_t can_capture_store(StoreNode* st, PhaseTransform* phase, bool can_reshape);
1219
1220 // Capture another store; reformat it to write my internal raw memory.
1221 // Return the captured copy, else NULL if there is some sort of problem.
1222 Node* capture_store(StoreNode* st, intptr_t start, PhaseTransform* phase, bool can_reshape);
1223
1224 // Find captured store which corresponds to the range [start..start+size).
1225 // Return my own memory projection (meaning the initial zero bits)
1226 // if there is no such store. Return NULL if there is a problem.
1227 Node* find_captured_store(intptr_t start, int size_in_bytes, PhaseTransform* phase);
1228
1229 // Called when the associated AllocateNode is expanded into CFG.
1230 Node* complete_stores(Node* rawctl, Node* rawmem, Node* rawptr,
1231 intptr_t header_size, Node* size_in_bytes,
1232 PhaseGVN* phase);
1233
1234 private:
1235 void remove_extra_zeroes();
1236
1237 // Find out where a captured store should be placed (or already is placed).
1238 int captured_store_insertion_point(intptr_t start, int size_in_bytes,
1239 PhaseTransform* phase);
1240
1241 static intptr_t get_store_offset(Node* st, PhaseTransform* phase);
1242
1243 Node* make_raw_address(intptr_t offset, PhaseTransform* phase);
1244
1245 bool detect_init_independence(Node* n, int& count);
1246
1247 void coalesce_subword_stores(intptr_t header_size, Node* size_in_bytes,
1248 PhaseGVN* phase);
1249
1250 intptr_t find_next_fullword_store(uint i, PhaseGVN* phase);
1251 };
1252
1253 //------------------------------MergeMem---------------------------------------
1254 // (See comment in memnode.cpp near MergeMemNode::MergeMemNode for semantics.)
1255 class MergeMemNode: public Node {
1256 virtual uint hash() const ; // { return NO_HASH; }
1257 virtual uint cmp( const Node &n ) const ; // Always fail, except on self
1258 friend class MergeMemStream;
1259 MergeMemNode(Node* def); // clients use MergeMemNode::make
1260
1261 public:
1262 // If the input is a whole memory state, clone it with all its slices intact.
1263 // Otherwise, make a new memory state with just that base memory input.
1264 // In either case, the result is a newly created MergeMem.
1265 static MergeMemNode* make(Compile* C, Node* base_memory);
1266
1267 virtual int Opcode() const;
1268 virtual Node *Identity( PhaseTransform *phase );
1269 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
1270 virtual uint ideal_reg() const { return NotAMachineReg; }
1271 virtual uint match_edge(uint idx) const { return 0; }
1272 virtual const RegMask &out_RegMask() const;
1273 virtual const Type *bottom_type() const { return Type::MEMORY; }
1274 virtual const TypePtr *adr_type() const { return TypePtr::BOTTOM; }
1275 // sparse accessors
1276 // Fetch the previously stored "set_memory_at", or else the base memory.
1277 // (Caller should clone it if it is a phi-nest.)
1278 Node* memory_at(uint alias_idx) const;
1279 // set the memory, regardless of its previous value
1280 void set_memory_at(uint alias_idx, Node* n);
1281 // the "base" is the memory that provides the non-finite support
1282 Node* base_memory() const { return in(Compile::AliasIdxBot); }
1283 // warning: setting the base can implicitly set any of the other slices too
1284 void set_base_memory(Node* def);
1285 // sentinel value which denotes a copy of the base memory:
1286 Node* empty_memory() const { return in(Compile::AliasIdxTop); }
1287 static Node* make_empty_memory(); // where the sentinel comes from
1288 bool is_empty_memory(Node* n) const { assert((n == empty_memory()) == n->is_top(), "sanity"); return n->is_top(); }
1289 // hook for the iterator, to perform any necessary setup
1290 void iteration_setup(const MergeMemNode* other = NULL);
1291 // push sentinels until I am at least as long as the other (semantic no-op)
1292 void grow_to_match(const MergeMemNode* other);
1293 bool verify_sparse() const PRODUCT_RETURN0;
1294 #ifndef PRODUCT
1295 virtual void dump_spec(outputStream *st) const;
1296 #endif
1297 };
1298
1299 class MergeMemStream : public StackObj {
1300 private:
1301 MergeMemNode* _mm;
1302 const MergeMemNode* _mm2; // optional second guy, contributes non-empty iterations
1303 Node* _mm_base; // loop-invariant base memory of _mm
1304 int _idx;
1305 int _cnt;
1306 Node* _mem;
1307 Node* _mem2;
1308 int _cnt2;
1309
1310 void init(MergeMemNode* mm, const MergeMemNode* mm2 = NULL) {
1311 // subsume_node will break sparseness at times, whenever a memory slice
1312 // folds down to a copy of the base ("fat") memory. In such a case,
1313 // the raw edge will update to base, although it should be top.
1314 // This iterator will recognize either top or base_memory as an
1315 // "empty" slice. See is_empty, is_empty2, and next below.
1316 //
1317 // The sparseness property is repaired in MergeMemNode::Ideal.
1318 // As long as access to a MergeMem goes through this iterator
1319 // or the memory_at accessor, flaws in the sparseness will
1320 // never be observed.
1321 //
1322 // Also, iteration_setup repairs sparseness.
1323 assert(mm->verify_sparse(), "please, no dups of base");
1324 assert(mm2==NULL || mm2->verify_sparse(), "please, no dups of base");
1325
1326 _mm = mm;
1327 _mm_base = mm->base_memory();
1328 _mm2 = mm2;
1329 _cnt = mm->req();
1330 _idx = Compile::AliasIdxBot-1; // start at the base memory
1331 _mem = NULL;
1332 _mem2 = NULL;
1333 }
1334
1335 #ifdef ASSERT
1336 Node* check_memory() const {
1337 if (at_base_memory())
1338 return _mm->base_memory();
1339 else if ((uint)_idx < _mm->req() && !_mm->in(_idx)->is_top())
1340 return _mm->memory_at(_idx);
1341 else
1342 return _mm_base;
1343 }
1344 Node* check_memory2() const {
1345 return at_base_memory()? _mm2->base_memory(): _mm2->memory_at(_idx);
1346 }
1347 #endif
1348
1349 static bool match_memory(Node* mem, const MergeMemNode* mm, int idx) PRODUCT_RETURN0;
1350 void assert_synch() const {
1351 assert(!_mem || _idx >= _cnt || match_memory(_mem, _mm, _idx),
1352 "no side-effects except through the stream");
1353 }
1354
1355 public:
1356
1357 // expected usages:
1358 // for (MergeMemStream mms(mem->is_MergeMem()); next_non_empty(); ) { ... }
1359 // for (MergeMemStream mms(mem1, mem2); next_non_empty2(); ) { ... }
1360
1361 // iterate over one merge
1362 MergeMemStream(MergeMemNode* mm) {
1363 mm->iteration_setup();
1364 init(mm);
1365 debug_only(_cnt2 = 999);
1366 }
1367 // iterate in parallel over two merges
1368 // only iterates through non-empty elements of mm2
1369 MergeMemStream(MergeMemNode* mm, const MergeMemNode* mm2) {
1370 assert(mm2, "second argument must be a MergeMem also");
1371 ((MergeMemNode*)mm2)->iteration_setup(); // update hidden state
1372 mm->iteration_setup(mm2);
1373 init(mm, mm2);
1374 _cnt2 = mm2->req();
1375 }
1376 #ifdef ASSERT
1377 ~MergeMemStream() {
1378 assert_synch();
1379 }
1380 #endif
1381
1382 MergeMemNode* all_memory() const {
1383 return _mm;
1384 }
1385 Node* base_memory() const {
1386 assert(_mm_base == _mm->base_memory(), "no update to base memory, please");
1387 return _mm_base;
1388 }
1389 const MergeMemNode* all_memory2() const {
1390 assert(_mm2 != NULL, "");
1391 return _mm2;
1392 }
1393 bool at_base_memory() const {
1394 return _idx == Compile::AliasIdxBot;
1395 }
1396 int alias_idx() const {
1397 assert(_mem, "must call next 1st");
1398 return _idx;
1399 }
1400
1401 const TypePtr* adr_type() const {
1402 return Compile::current()->get_adr_type(alias_idx());
1403 }
1404
1405 const TypePtr* adr_type(Compile* C) const {
1406 return C->get_adr_type(alias_idx());
1407 }
1408 bool is_empty() const {
1409 assert(_mem, "must call next 1st");
1410 assert(_mem->is_top() == (_mem==_mm->empty_memory()), "correct sentinel");
1411 return _mem->is_top();
1412 }
1413 bool is_empty2() const {
1414 assert(_mem2, "must call next 1st");
1415 assert(_mem2->is_top() == (_mem2==_mm2->empty_memory()), "correct sentinel");
1416 return _mem2->is_top();
1417 }
1418 Node* memory() const {
1419 assert(!is_empty(), "must not be empty");
1420 assert_synch();
1421 return _mem;
1422 }
1423 // get the current memory, regardless of empty or non-empty status
1424 Node* force_memory() const {
1425 assert(!is_empty() || !at_base_memory(), "");
1426 // Use _mm_base to defend against updates to _mem->base_memory().
1427 Node *mem = _mem->is_top() ? _mm_base : _mem;
1428 assert(mem == check_memory(), "");
1429 return mem;
1430 }
1431 Node* memory2() const {
1432 assert(_mem2 == check_memory2(), "");
1433 return _mem2;
1434 }
1435 void set_memory(Node* mem) {
1436 if (at_base_memory()) {
1437 // Note that this does not change the invariant _mm_base.
1438 _mm->set_base_memory(mem);
1439 } else {
1440 _mm->set_memory_at(_idx, mem);
1441 }
1442 _mem = mem;
1443 assert_synch();
1444 }
1445
1446 // Recover from a side effect to the MergeMemNode.
1447 void set_memory() {
1448 _mem = _mm->in(_idx);
1449 }
1450
1451 bool next() { return next(false); }
1452 bool next2() { return next(true); }
1453
1454 bool next_non_empty() { return next_non_empty(false); }
1455 bool next_non_empty2() { return next_non_empty(true); }
1456 // next_non_empty2 can yield states where is_empty() is true
1457
1458 private:
1459 // find the next item, which might be empty
1460 bool next(bool have_mm2) {
1461 assert((_mm2 != NULL) == have_mm2, "use other next");
1462 assert_synch();
1463 if (++_idx < _cnt) {
1464 // Note: This iterator allows _mm to be non-sparse.
1465 // It behaves the same whether _mem is top or base_memory.
1466 _mem = _mm->in(_idx);
1467 if (have_mm2)
1468 _mem2 = _mm2->in((_idx < _cnt2) ? _idx : Compile::AliasIdxTop);
1469 return true;
1470 }
1471 return false;
1472 }
1473
1474 // find the next non-empty item
1475 bool next_non_empty(bool have_mm2) {
1476 while (next(have_mm2)) {
1477 if (!is_empty()) {
1478 // make sure _mem2 is filled in sensibly
1479 if (have_mm2 && _mem2->is_top()) _mem2 = _mm2->base_memory();
1480 return true;
1481 } else if (have_mm2 && !is_empty2()) {
1482 return true; // is_empty() == true
1483 }
1484 }
1485 return false;
1486 }
1487 };
1488
1489 //------------------------------Prefetch---------------------------------------
1490
1491 // Non-faulting prefetch load. Prefetch for many reads.
1492 class PrefetchReadNode : public Node {
1493 public:
1494 PrefetchReadNode(Node *abio, Node *adr) : Node(0,abio,adr) {}
1495 virtual int Opcode() const;
1496 virtual uint ideal_reg() const { return NotAMachineReg; }
1497 virtual uint match_edge(uint idx) const { return idx==2; }
1498 virtual const Type *bottom_type() const { return Type::ABIO; }
1499 };
1500
1501 // Non-faulting prefetch load. Prefetch for many reads & many writes.
1502 class PrefetchWriteNode : public Node {
1503 public:
1504 PrefetchWriteNode(Node *abio, Node *adr) : Node(0,abio,adr) {}
1505 virtual int Opcode() const;
1506 virtual uint ideal_reg() const { return NotAMachineReg; }
1507 virtual uint match_edge(uint idx) const { return idx==2; }
1508 virtual const Type *bottom_type() const { return Type::ABIO; }
1509 };
1510
1511 // Allocation prefetch which may fault, TLAB size have to be adjusted.
1512 class PrefetchAllocationNode : public Node {
1513 public:
1514 PrefetchAllocationNode(Node *mem, Node *adr) : Node(0,mem,adr) {}
1515 virtual int Opcode() const;
1516 virtual uint ideal_reg() const { return NotAMachineReg; }
1517 virtual uint match_edge(uint idx) const { return idx==2; }
1518 virtual const Type *bottom_type() const { return ( AllocatePrefetchStyle == 3 ) ? Type::MEMORY : Type::ABIO; }
1519 };
1520
1521 #endif // SHARE_VM_OPTO_MEMNODE_HPP