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
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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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
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
263 Node* can_see_arraycopy_value(Node* st, PhaseTransform* phase) const;
264
265 // depends_only_on_test is almost always true, and needs to be almost always
266 // true to enable key hoisting & commoning optimizations. However, for the
267 // special case of RawPtr loads from TLS top & end, and other loads performed by
268 // GC barriers, the control edge carries the dependence preventing hoisting past
269 // a Safepoint instead of the memory edge. (An unfortunate consequence of having
270 // Safepoints not set Raw Memory; itself an unfortunate consequence of having Nodes
271 // which produce results (new raw memory state) inside of loops preventing all
272 // manner of other optimizations). Basically, it's ugly but so is the alternative.
273 // See comment in macro.cpp, around line 125 expand_allocate_common().
274 virtual bool depends_only_on_test() const { return adr_type() != TypeRawPtr::BOTTOM && _depends_only_on_test; }
275 };
276
277 //------------------------------LoadBNode--------------------------------------
278 // Load a byte (8bits signed) from memory
279 class LoadBNode : public LoadNode {
280 public:
281 LoadBNode(Node *c, Node *mem, Node *adr, const TypePtr* at, const TypeInt *ti, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
282 : LoadNode(c, mem, adr, at, ti, mo, control_dependency) {}
283 virtual int Opcode() const;
284 virtual uint ideal_reg() const { return Op_RegI; }
285 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
286 virtual const Type *Value(PhaseTransform *phase) const;
287 virtual int store_Opcode() const { return Op_StoreB; }
288 virtual BasicType memory_type() const { return T_BYTE; }
289 };
290
291 //------------------------------LoadUBNode-------------------------------------
292 // Load a unsigned byte (8bits unsigned) from memory
293 class LoadUBNode : public LoadNode {
294 public:
295 LoadUBNode(Node* c, Node* mem, Node* adr, const TypePtr* at, const TypeInt* ti, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
296 : LoadNode(c, mem, adr, at, ti, mo, control_dependency) {}
297 virtual int Opcode() const;
298 virtual uint ideal_reg() const { return Op_RegI; }
299 virtual Node* Ideal(PhaseGVN *phase, bool can_reshape);
300 virtual const Type *Value(PhaseTransform *phase) const;
301 virtual int store_Opcode() const { return Op_StoreB; }
302 virtual BasicType memory_type() const { return T_BYTE; }
303 };
304
305 //------------------------------LoadUSNode-------------------------------------
306 // Load an unsigned short/char (16bits unsigned) from memory
307 class LoadUSNode : public LoadNode {
308 public:
309 LoadUSNode(Node *c, Node *mem, Node *adr, const TypePtr* at, const TypeInt *ti, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
310 : LoadNode(c, mem, adr, at, ti, mo, control_dependency) {}
311 virtual int Opcode() const;
312 virtual uint ideal_reg() const { return Op_RegI; }
313 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
314 virtual const Type *Value(PhaseTransform *phase) const;
315 virtual int store_Opcode() const { return Op_StoreC; }
316 virtual BasicType memory_type() const { return T_CHAR; }
317 };
318
319 //------------------------------LoadSNode--------------------------------------
320 // Load a short (16bits signed) from memory
321 class LoadSNode : public LoadNode {
322 public:
323 LoadSNode(Node *c, Node *mem, Node *adr, const TypePtr* at, const TypeInt *ti, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
324 : LoadNode(c, mem, adr, at, ti, mo, control_dependency) {}
325 virtual int Opcode() const;
326 virtual uint ideal_reg() const { return Op_RegI; }
327 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
328 virtual const Type *Value(PhaseTransform *phase) const;
329 virtual int store_Opcode() const { return Op_StoreC; }
330 virtual BasicType memory_type() const { return T_SHORT; }
331 };
332
333 //------------------------------LoadINode--------------------------------------
334 // Load an integer from memory
335 class LoadINode : public LoadNode {
336 public:
337 LoadINode(Node *c, Node *mem, Node *adr, const TypePtr* at, const TypeInt *ti, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
338 : LoadNode(c, mem, adr, at, ti, mo, control_dependency) {}
339 virtual int Opcode() const;
340 virtual uint ideal_reg() const { return Op_RegI; }
341 virtual int store_Opcode() const { return Op_StoreI; }
342 virtual BasicType memory_type() const { return T_INT; }
343 };
344
345 //------------------------------LoadRangeNode----------------------------------
346 // Load an array length from the array
347 class LoadRangeNode : public LoadINode {
348 public:
349 LoadRangeNode(Node *c, Node *mem, Node *adr, const TypeInt *ti = TypeInt::POS)
350 : LoadINode(c, mem, adr, TypeAryPtr::RANGE, ti, MemNode::unordered) {}
351 virtual int Opcode() const;
352 virtual const Type *Value( PhaseTransform *phase ) const;
353 virtual Node *Identity( PhaseTransform *phase );
354 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
355 };
356
357 //------------------------------LoadLNode--------------------------------------
358 // Load a long from memory
359 class LoadLNode : public LoadNode {
360 virtual uint hash() const { return LoadNode::hash() + _require_atomic_access; }
361 virtual uint cmp( const Node &n ) const {
362 return _require_atomic_access == ((LoadLNode&)n)._require_atomic_access
363 && LoadNode::cmp(n);
364 }
365 virtual uint size_of() const { return sizeof(*this); }
366 const bool _require_atomic_access; // is piecewise load forbidden?
367
368 public:
369 LoadLNode(Node *c, Node *mem, Node *adr, const TypePtr* at, const TypeLong *tl,
370 MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest, bool require_atomic_access = false)
371 : LoadNode(c, mem, adr, at, tl, mo, control_dependency), _require_atomic_access(require_atomic_access) {}
372 virtual int Opcode() const;
373 virtual uint ideal_reg() const { return Op_RegL; }
374 virtual int store_Opcode() const { return Op_StoreL; }
375 virtual BasicType memory_type() const { return T_LONG; }
376 bool require_atomic_access() const { return _require_atomic_access; }
377 static LoadLNode* make_atomic(Node* ctl, Node* mem, Node* adr, const TypePtr* adr_type,
378 const Type* rt, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest);
379 #ifndef PRODUCT
380 virtual void dump_spec(outputStream *st) const {
381 LoadNode::dump_spec(st);
382 if (_require_atomic_access) st->print(" Atomic!");
383 }
384 #endif
385 };
386
387 //------------------------------LoadL_unalignedNode----------------------------
388 // Load a long from unaligned memory
389 class LoadL_unalignedNode : public LoadLNode {
390 public:
391 LoadL_unalignedNode(Node *c, Node *mem, Node *adr, const TypePtr* at, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
392 : LoadLNode(c, mem, adr, at, TypeLong::LONG, mo, control_dependency) {}
393 virtual int Opcode() const;
394 };
395
396 //------------------------------LoadFNode--------------------------------------
397 // Load a float (64 bits) from memory
398 class LoadFNode : public LoadNode {
399 public:
400 LoadFNode(Node *c, Node *mem, Node *adr, const TypePtr* at, const Type *t, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
401 : LoadNode(c, mem, adr, at, t, mo, control_dependency) {}
402 virtual int Opcode() const;
403 virtual uint ideal_reg() const { return Op_RegF; }
404 virtual int store_Opcode() const { return Op_StoreF; }
405 virtual BasicType memory_type() const { return T_FLOAT; }
406 };
407
408 //------------------------------LoadDNode--------------------------------------
409 // Load a double (64 bits) from memory
410 class LoadDNode : public LoadNode {
411 virtual uint hash() const { return LoadNode::hash() + _require_atomic_access; }
412 virtual uint cmp( const Node &n ) const {
413 return _require_atomic_access == ((LoadDNode&)n)._require_atomic_access
414 && LoadNode::cmp(n);
415 }
416 virtual uint size_of() const { return sizeof(*this); }
417 const bool _require_atomic_access; // is piecewise load forbidden?
418
419 public:
420 LoadDNode(Node *c, Node *mem, Node *adr, const TypePtr* at, const Type *t,
421 MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest, bool require_atomic_access = false)
422 : LoadNode(c, mem, adr, at, t, mo, control_dependency), _require_atomic_access(require_atomic_access) {}
423 virtual int Opcode() const;
424 virtual uint ideal_reg() const { return Op_RegD; }
425 virtual int store_Opcode() const { return Op_StoreD; }
426 virtual BasicType memory_type() const { return T_DOUBLE; }
427 bool require_atomic_access() const { return _require_atomic_access; }
428 static LoadDNode* make_atomic(Node* ctl, Node* mem, Node* adr, const TypePtr* adr_type,
429 const Type* rt, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest);
430 #ifndef PRODUCT
431 virtual void dump_spec(outputStream *st) const {
432 LoadNode::dump_spec(st);
433 if (_require_atomic_access) st->print(" Atomic!");
434 }
435 #endif
436 };
437
438 //------------------------------LoadD_unalignedNode----------------------------
439 // Load a double from unaligned memory
440 class LoadD_unalignedNode : public LoadDNode {
441 public:
442 LoadD_unalignedNode(Node *c, Node *mem, Node *adr, const TypePtr* at, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
443 : LoadDNode(c, mem, adr, at, Type::DOUBLE, mo, control_dependency) {}
444 virtual int Opcode() const;
445 };
446
447 //------------------------------LoadPNode--------------------------------------
448 // Load a pointer from memory (either object or array)
449 class LoadPNode : public LoadNode {
450 public:
451 LoadPNode(Node *c, Node *mem, Node *adr, const TypePtr *at, const TypePtr* t, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
452 : LoadNode(c, mem, adr, at, t, mo, control_dependency) {}
453 virtual int Opcode() const;
454 virtual uint ideal_reg() const { return Op_RegP; }
455 virtual int store_Opcode() const { return Op_StoreP; }
456 virtual BasicType memory_type() const { return T_ADDRESS; }
457 };
458
459
460 //------------------------------LoadNNode--------------------------------------
461 // Load a narrow oop from memory (either object or array)
462 class LoadNNode : public LoadNode {
463 public:
464 LoadNNode(Node *c, Node *mem, Node *adr, const TypePtr *at, const Type* t, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
465 : LoadNode(c, mem, adr, at, t, mo, control_dependency) {}
466 virtual int Opcode() const;
467 virtual uint ideal_reg() const { return Op_RegN; }
468 virtual int store_Opcode() const { return Op_StoreN; }
469 virtual BasicType memory_type() const { return T_NARROWOOP; }
470 };
471
472 //------------------------------LoadKlassNode----------------------------------
473 // Load a Klass from an object
474 class LoadKlassNode : public LoadPNode {
475 protected:
476 // In most cases, LoadKlassNode does not have the control input set. If the control
477 // input is set, it must not be removed (by LoadNode::Ideal()).
478 virtual bool can_remove_control() const;
479 public:
480 LoadKlassNode(Node *c, Node *mem, Node *adr, const TypePtr *at, const TypeKlassPtr *tk, MemOrd mo)
481 : LoadPNode(c, mem, adr, at, tk, mo) {}
482 virtual int Opcode() const;
483 virtual const Type *Value( PhaseTransform *phase ) const;
484 virtual Node *Identity( PhaseTransform *phase );
485 virtual bool depends_only_on_test() const { return true; }
486
487 // Polymorphic factory method:
488 static Node* make(PhaseGVN& gvn, Node* ctl, Node* mem, Node* adr, const TypePtr* at,
489 const TypeKlassPtr* tk = TypeKlassPtr::OBJECT);
490 };
491
492 //------------------------------LoadNKlassNode---------------------------------
493 // Load a narrow Klass from an object.
494 class LoadNKlassNode : public LoadNNode {
495 public:
496 LoadNKlassNode(Node *c, Node *mem, Node *adr, const TypePtr *at, const TypeNarrowKlass *tk, MemOrd mo)
497 : LoadNNode(c, mem, adr, at, tk, mo) {}
498 virtual int Opcode() const;
499 virtual uint ideal_reg() const { return Op_RegN; }
500 virtual int store_Opcode() const { return Op_StoreNKlass; }
501 virtual BasicType memory_type() const { return T_NARROWKLASS; }
502
503 virtual const Type *Value( PhaseTransform *phase ) const;
504 virtual Node *Identity( PhaseTransform *phase );
505 virtual bool depends_only_on_test() const { return true; }
506 };
507
508
509 //------------------------------StoreNode--------------------------------------
510 // Store value; requires Store, Address and Value
511 class StoreNode : public MemNode {
512 private:
513 // On platforms with weak memory ordering (e.g., PPC, Ia64) we distinguish
514 // stores that can be reordered, and such requiring release semantics to
515 // adhere to the Java specification. The required behaviour is stored in
516 // this field.
517 const MemOrd _mo;
518 // Needed for proper cloning.
519 virtual uint size_of() const { return sizeof(*this); }
520 protected:
521 virtual uint cmp( const Node &n ) const;
522 virtual bool depends_only_on_test() const { return false; }
523
524 Node *Ideal_masked_input (PhaseGVN *phase, uint mask);
525 Node *Ideal_sign_extended_input(PhaseGVN *phase, int num_bits);
526
527 public:
528 // We must ensure that stores of object references will be visible
529 // only after the object's initialization. So the callers of this
530 // procedure must indicate that the store requires `release'
531 // semantics, if the stored value is an object reference that might
532 // point to a new object and may become externally visible.
533 StoreNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, MemOrd mo)
534 : MemNode(c, mem, adr, at, val), _mo(mo) {
535 init_class_id(Class_Store);
536 }
537 StoreNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, Node *oop_store, MemOrd mo)
538 : MemNode(c, mem, adr, at, val, oop_store), _mo(mo) {
539 init_class_id(Class_Store);
540 }
541
542 inline bool is_unordered() const { return !is_release(); }
543 inline bool is_release() const {
544 assert((_mo == unordered || _mo == release), "unexpected");
545 return _mo == release;
546 }
547
548 // Conservatively release stores of object references in order to
549 // ensure visibility of object initialization.
550 static inline MemOrd release_if_reference(const BasicType t) {
551 #ifdef AARCH64
552 // AArch64 doesn't need a release store here because object
553 // initialization contains the necessary barriers.
554 return unordered;
555 #else
556 const MemOrd mo = (t == T_ARRAY ||
557 t == T_ADDRESS || // Might be the address of an object reference (`boxing').
558 t == T_OBJECT) ? release : unordered;
559 return mo;
560 #endif
561 }
562
563 // Polymorphic factory method
564 //
565 // We must ensure that stores of object references will be visible
566 // only after the object's initialization. So the callers of this
567 // procedure must indicate that the store requires `release'
568 // semantics, if the stored value is an object reference that might
569 // point to a new object and may become externally visible.
570 static StoreNode* make(PhaseGVN& gvn, Node *c, Node *mem, Node *adr,
571 const TypePtr* at, Node *val, BasicType bt, MemOrd mo);
572
573 virtual uint hash() const; // Check the type
574
575 // If the store is to Field memory and the pointer is non-null, we can
576 // zero out the control input.
577 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
578
579 // Compute a new Type for this node. Basically we just do the pre-check,
580 // then call the virtual add() to set the type.
581 virtual const Type *Value( PhaseTransform *phase ) const;
582
583 // Check for identity function on memory (Load then Store at same address)
584 virtual Node *Identity( PhaseTransform *phase );
585
586 // Do not match memory edge
587 virtual uint match_edge(uint idx) const;
588
589 virtual const Type *bottom_type() const; // returns Type::MEMORY
590
591 // Map a store opcode to its corresponding own opcode, trivially.
592 virtual int store_Opcode() const { return Opcode(); }
593
594 // have all possible loads of the value stored been optimized away?
595 bool value_never_loaded(PhaseTransform *phase) const;
596 };
597
598 //------------------------------StoreBNode-------------------------------------
599 // Store byte to memory
600 class StoreBNode : public StoreNode {
601 public:
602 StoreBNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, MemOrd mo)
603 : StoreNode(c, mem, adr, at, val, mo) {}
604 virtual int Opcode() const;
605 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
606 virtual BasicType memory_type() const { return T_BYTE; }
607 };
608
609 //------------------------------StoreCNode-------------------------------------
610 // Store char/short to memory
611 class StoreCNode : public StoreNode {
612 public:
613 StoreCNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, MemOrd mo)
614 : StoreNode(c, mem, adr, at, val, mo) {}
615 virtual int Opcode() const;
616 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
617 virtual BasicType memory_type() const { return T_CHAR; }
618 };
619
620 //------------------------------StoreINode-------------------------------------
621 // Store int to memory
622 class StoreINode : public StoreNode {
623 public:
624 StoreINode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, MemOrd mo)
625 : StoreNode(c, mem, adr, at, val, mo) {}
626 virtual int Opcode() const;
627 virtual BasicType memory_type() const { return T_INT; }
628 };
629
630 //------------------------------StoreLNode-------------------------------------
631 // Store long to memory
632 class StoreLNode : public StoreNode {
633 virtual uint hash() const { return StoreNode::hash() + _require_atomic_access; }
634 virtual uint cmp( const Node &n ) const {
635 return _require_atomic_access == ((StoreLNode&)n)._require_atomic_access
636 && StoreNode::cmp(n);
637 }
638 virtual uint size_of() const { return sizeof(*this); }
639 const bool _require_atomic_access; // is piecewise store forbidden?
640
641 public:
642 StoreLNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, MemOrd mo, bool require_atomic_access = false)
643 : StoreNode(c, mem, adr, at, val, mo), _require_atomic_access(require_atomic_access) {}
644 virtual int Opcode() const;
645 virtual BasicType memory_type() const { return T_LONG; }
646 bool require_atomic_access() const { return _require_atomic_access; }
647 static StoreLNode* make_atomic(Node* ctl, Node* mem, Node* adr, const TypePtr* adr_type, Node* val, MemOrd mo);
648 #ifndef PRODUCT
649 virtual void dump_spec(outputStream *st) const {
650 StoreNode::dump_spec(st);
651 if (_require_atomic_access) st->print(" Atomic!");
652 }
653 #endif
654 };
655
656 //------------------------------StoreFNode-------------------------------------
657 // Store float to memory
658 class StoreFNode : public StoreNode {
659 public:
660 StoreFNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, MemOrd mo)
661 : StoreNode(c, mem, adr, at, val, mo) {}
662 virtual int Opcode() const;
663 virtual BasicType memory_type() const { return T_FLOAT; }
664 };
665
666 //------------------------------StoreDNode-------------------------------------
667 // Store double to memory
668 class StoreDNode : public StoreNode {
669 virtual uint hash() const { return StoreNode::hash() + _require_atomic_access; }
670 virtual uint cmp( const Node &n ) const {
671 return _require_atomic_access == ((StoreDNode&)n)._require_atomic_access
672 && StoreNode::cmp(n);
673 }
674 virtual uint size_of() const { return sizeof(*this); }
675 const bool _require_atomic_access; // is piecewise store forbidden?
676 public:
677 StoreDNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val,
678 MemOrd mo, bool require_atomic_access = false)
679 : StoreNode(c, mem, adr, at, val, mo), _require_atomic_access(require_atomic_access) {}
680 virtual int Opcode() const;
681 virtual BasicType memory_type() const { return T_DOUBLE; }
682 bool require_atomic_access() const { return _require_atomic_access; }
683 static StoreDNode* make_atomic(Node* ctl, Node* mem, Node* adr, const TypePtr* adr_type, Node* val, MemOrd mo);
684 #ifndef PRODUCT
685 virtual void dump_spec(outputStream *st) const {
686 StoreNode::dump_spec(st);
687 if (_require_atomic_access) st->print(" Atomic!");
688 }
689 #endif
690
691 };
692
693 //------------------------------StorePNode-------------------------------------
694 // Store pointer to memory
695 class StorePNode : public StoreNode {
696 public:
697 StorePNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, MemOrd mo)
698 : StoreNode(c, mem, adr, at, val, mo) {}
699 virtual int Opcode() const;
700 virtual BasicType memory_type() const { return T_ADDRESS; }
701 };
702
703 //------------------------------StoreNNode-------------------------------------
704 // Store narrow oop to memory
705 class StoreNNode : public StoreNode {
706 public:
707 StoreNNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, MemOrd mo)
708 : StoreNode(c, mem, adr, at, val, mo) {}
709 virtual int Opcode() const;
710 virtual BasicType memory_type() const { return T_NARROWOOP; }
711 };
712
713 //------------------------------StoreNKlassNode--------------------------------------
714 // Store narrow klass to memory
715 class StoreNKlassNode : public StoreNNode {
716 public:
717 StoreNKlassNode(Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, MemOrd mo)
718 : StoreNNode(c, mem, adr, at, val, mo) {}
719 virtual int Opcode() const;
720 virtual BasicType memory_type() const { return T_NARROWKLASS; }
721 };
722
723 //------------------------------StoreCMNode-----------------------------------
724 // Store card-mark byte to memory for CM
725 // The last StoreCM before a SafePoint must be preserved and occur after its "oop" store
726 // Preceeding equivalent StoreCMs may be eliminated.
727 class StoreCMNode : public StoreNode {
728 private:
729 virtual uint hash() const { return StoreNode::hash() + _oop_alias_idx; }
730 virtual uint cmp( const Node &n ) const {
731 return _oop_alias_idx == ((StoreCMNode&)n)._oop_alias_idx
732 && StoreNode::cmp(n);
733 }
734 virtual uint size_of() const { return sizeof(*this); }
735 int _oop_alias_idx; // The alias_idx of OopStore
736
737 public:
738 StoreCMNode( Node *c, Node *mem, Node *adr, const TypePtr* at, Node *val, Node *oop_store, int oop_alias_idx ) :
739 StoreNode(c, mem, adr, at, val, oop_store, MemNode::release),
740 _oop_alias_idx(oop_alias_idx) {
741 assert(_oop_alias_idx >= Compile::AliasIdxRaw ||
742 _oop_alias_idx == Compile::AliasIdxBot && Compile::current()->AliasLevel() == 0,
743 "bad oop alias idx");
744 }
745 virtual int Opcode() const;
746 virtual Node *Identity( PhaseTransform *phase );
747 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
748 virtual const Type *Value( PhaseTransform *phase ) const;
749 virtual BasicType memory_type() const { return T_VOID; } // unspecific
750 int oop_alias_idx() const { return _oop_alias_idx; }
751 };
752
753 //------------------------------LoadPLockedNode---------------------------------
754 // Load-locked a pointer from memory (either object or array).
755 // On Sparc & Intel this is implemented as a normal pointer load.
756 // On PowerPC and friends it's a real load-locked.
757 class LoadPLockedNode : public LoadPNode {
758 public:
759 LoadPLockedNode(Node *c, Node *mem, Node *adr, MemOrd mo)
760 : LoadPNode(c, mem, adr, TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM, mo) {}
761 virtual int Opcode() const;
762 virtual int store_Opcode() const { return Op_StorePConditional; }
763 virtual bool depends_only_on_test() const { return true; }
764 };
765
766 //------------------------------SCMemProjNode---------------------------------------
767 // This class defines a projection of the memory state of a store conditional node.
768 // These nodes return a value, but also update memory.
769 class SCMemProjNode : public ProjNode {
770 public:
771 enum {SCMEMPROJCON = (uint)-2};
772 SCMemProjNode( Node *src) : ProjNode( src, SCMEMPROJCON) { }
773 virtual int Opcode() const;
774 virtual bool is_CFG() const { return false; }
775 virtual const Type *bottom_type() const {return Type::MEMORY;}
776 virtual const TypePtr *adr_type() const {
777 Node* ctrl = in(0);
778 if (ctrl == NULL) return NULL; // node is dead
779 return ctrl->in(MemNode::Memory)->adr_type();
780 }
781 virtual uint ideal_reg() const { return 0;} // memory projections don't have a register
782 virtual const Type *Value( PhaseTransform *phase ) const;
783 #ifndef PRODUCT
784 virtual void dump_spec(outputStream *st) const {};
785 #endif
786 };
787
788 //------------------------------LoadStoreNode---------------------------
789 // Note: is_Mem() method returns 'true' for this class.
790 class LoadStoreNode : public Node {
791 private:
792 const Type* const _type; // What kind of value is loaded?
793 const TypePtr* _adr_type; // What kind of memory is being addressed?
794 virtual uint size_of() const; // Size is bigger
795 public:
796 LoadStoreNode( Node *c, Node *mem, Node *adr, Node *val, const TypePtr* at, const Type* rt, uint required );
797 virtual bool depends_only_on_test() const { return false; }
798 virtual uint match_edge(uint idx) const { return idx == MemNode::Address || idx == MemNode::ValueIn; }
799
800 virtual const Type *bottom_type() const { return _type; }
801 virtual uint ideal_reg() const;
802 virtual const class TypePtr *adr_type() const { return _adr_type; } // returns bottom_type of address
803
804 bool result_not_used() const;
805 };
806
807 class LoadStoreConditionalNode : public LoadStoreNode {
808 public:
809 enum {
810 ExpectedIn = MemNode::ValueIn+1 // One more input than MemNode
811 };
812 LoadStoreConditionalNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex);
813 };
814
815 //------------------------------StorePConditionalNode---------------------------
816 // Conditionally store pointer to memory, if no change since prior
817 // load-locked. Sets flags for success or failure of the store.
818 class StorePConditionalNode : public LoadStoreConditionalNode {
819 public:
820 StorePConditionalNode( Node *c, Node *mem, Node *adr, Node *val, Node *ll ) : LoadStoreConditionalNode(c, mem, adr, val, ll) { }
821 virtual int Opcode() const;
822 // Produces flags
823 virtual uint ideal_reg() const { return Op_RegFlags; }
824 };
825
826 //------------------------------StoreIConditionalNode---------------------------
827 // Conditionally store int to memory, if no change since prior
828 // load-locked. Sets flags for success or failure of the store.
829 class StoreIConditionalNode : public LoadStoreConditionalNode {
830 public:
831 StoreIConditionalNode( Node *c, Node *mem, Node *adr, Node *val, Node *ii ) : LoadStoreConditionalNode(c, mem, adr, val, ii) { }
832 virtual int Opcode() const;
833 // Produces flags
834 virtual uint ideal_reg() const { return Op_RegFlags; }
835 };
836
837 //------------------------------StoreLConditionalNode---------------------------
838 // Conditionally store long to memory, if no change since prior
839 // load-locked. Sets flags for success or failure of the store.
840 class StoreLConditionalNode : public LoadStoreConditionalNode {
841 public:
842 StoreLConditionalNode( Node *c, Node *mem, Node *adr, Node *val, Node *ll ) : LoadStoreConditionalNode(c, mem, adr, val, ll) { }
843 virtual int Opcode() const;
844 // Produces flags
845 virtual uint ideal_reg() const { return Op_RegFlags; }
846 };
847
848
849 //------------------------------CompareAndSwapLNode---------------------------
850 class CompareAndSwapLNode : public LoadStoreConditionalNode {
851 public:
852 CompareAndSwapLNode( Node *c, Node *mem, Node *adr, Node *val, Node *ex) : LoadStoreConditionalNode(c, mem, adr, val, ex) { }
853 virtual int Opcode() const;
854 };
855
856
857 //------------------------------CompareAndSwapINode---------------------------
858 class CompareAndSwapINode : public LoadStoreConditionalNode {
859 public:
860 CompareAndSwapINode( Node *c, Node *mem, Node *adr, Node *val, Node *ex) : LoadStoreConditionalNode(c, mem, adr, val, ex) { }
861 virtual int Opcode() const;
862 };
863
864
865 //------------------------------CompareAndSwapPNode---------------------------
866 class CompareAndSwapPNode : public LoadStoreConditionalNode {
867 public:
868 CompareAndSwapPNode( Node *c, Node *mem, Node *adr, Node *val, Node *ex) : LoadStoreConditionalNode(c, mem, adr, val, ex) { }
869 virtual int Opcode() const;
870 };
871
872 //------------------------------CompareAndSwapNNode---------------------------
873 class CompareAndSwapNNode : public LoadStoreConditionalNode {
874 public:
875 CompareAndSwapNNode( Node *c, Node *mem, Node *adr, Node *val, Node *ex) : LoadStoreConditionalNode(c, mem, adr, val, ex) { }
876 virtual int Opcode() const;
877 };
878
879 //------------------------------GetAndAddINode---------------------------
880 class GetAndAddINode : public LoadStoreNode {
881 public:
882 GetAndAddINode( Node *c, Node *mem, Node *adr, Node *val, const TypePtr* at ) : LoadStoreNode(c, mem, adr, val, at, TypeInt::INT, 4) { }
883 virtual int Opcode() const;
884 };
885
886 //------------------------------GetAndAddLNode---------------------------
887 class GetAndAddLNode : public LoadStoreNode {
888 public:
889 GetAndAddLNode( Node *c, Node *mem, Node *adr, Node *val, const TypePtr* at ) : LoadStoreNode(c, mem, adr, val, at, TypeLong::LONG, 4) { }
890 virtual int Opcode() const;
891 };
892
893
894 //------------------------------GetAndSetINode---------------------------
895 class GetAndSetINode : public LoadStoreNode {
896 public:
897 GetAndSetINode( Node *c, Node *mem, Node *adr, Node *val, const TypePtr* at ) : LoadStoreNode(c, mem, adr, val, at, TypeInt::INT, 4) { }
898 virtual int Opcode() const;
899 };
900
901 //------------------------------GetAndSetINode---------------------------
902 class GetAndSetLNode : public LoadStoreNode {
903 public:
904 GetAndSetLNode( Node *c, Node *mem, Node *adr, Node *val, const TypePtr* at ) : LoadStoreNode(c, mem, adr, val, at, TypeLong::LONG, 4) { }
905 virtual int Opcode() const;
906 };
907
908 //------------------------------GetAndSetPNode---------------------------
909 class GetAndSetPNode : public LoadStoreNode {
910 public:
911 GetAndSetPNode( Node *c, Node *mem, Node *adr, Node *val, const TypePtr* at, const Type* t ) : LoadStoreNode(c, mem, adr, val, at, t, 4) { }
912 virtual int Opcode() const;
913 };
914
915 //------------------------------GetAndSetNNode---------------------------
916 class GetAndSetNNode : public LoadStoreNode {
917 public:
918 GetAndSetNNode( Node *c, Node *mem, Node *adr, Node *val, const TypePtr* at, const Type* t ) : LoadStoreNode(c, mem, adr, val, at, t, 4) { }
919 virtual int Opcode() const;
920 };
921
922 //------------------------------ClearArray-------------------------------------
923 class ClearArrayNode: public Node {
924 public:
925 ClearArrayNode( Node *ctrl, Node *arymem, Node *word_cnt, Node *base )
926 : Node(ctrl,arymem,word_cnt,base) {
927 init_class_id(Class_ClearArray);
928 }
929 virtual int Opcode() const;
930 virtual const Type *bottom_type() const { return Type::MEMORY; }
931 // ClearArray modifies array elements, and so affects only the
932 // array memory addressed by the bottom_type of its base address.
933 virtual const class TypePtr *adr_type() const;
934 virtual Node *Identity( PhaseTransform *phase );
935 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
936 virtual uint match_edge(uint idx) const;
937
938 // Clear the given area of an object or array.
939 // The start offset must always be aligned mod BytesPerInt.
940 // The end offset must always be aligned mod BytesPerLong.
941 // Return the new memory.
942 static Node* clear_memory(Node* control, Node* mem, Node* dest,
943 intptr_t start_offset,
944 intptr_t end_offset,
945 PhaseGVN* phase);
946 static Node* clear_memory(Node* control, Node* mem, Node* dest,
947 intptr_t start_offset,
948 Node* end_offset,
949 PhaseGVN* phase);
950 static Node* clear_memory(Node* control, Node* mem, Node* dest,
951 Node* start_offset,
952 Node* end_offset,
953 PhaseGVN* phase);
954 // Return allocation input memory edge if it is different instance
955 // or itself if it is the one we are looking for.
956 static bool step_through(Node** np, uint instance_id, PhaseTransform* phase);
957 };
958
959 //------------------------------MemBar-----------------------------------------
960 // There are different flavors of Memory Barriers to match the Java Memory
961 // Model. Monitor-enter and volatile-load act as Aquires: no following ref
962 // can be moved to before them. We insert a MemBar-Acquire after a FastLock or
963 // volatile-load. Monitor-exit and volatile-store act as Release: no
964 // preceding ref can be moved to after them. We insert a MemBar-Release
965 // before a FastUnlock or volatile-store. All volatiles need to be
966 // serialized, so we follow all volatile-stores with a MemBar-Volatile to
967 // separate it from any following volatile-load.
968 class MemBarNode: public MultiNode {
969 virtual uint hash() const ; // { return NO_HASH; }
970 virtual uint cmp( const Node &n ) const ; // Always fail, except on self
971
972 virtual uint size_of() const { return sizeof(*this); }
973 // Memory type this node is serializing. Usually either rawptr or bottom.
974 const TypePtr* _adr_type;
975
976 public:
977 enum {
978 Precedent = TypeFunc::Parms // optional edge to force precedence
979 };
980 MemBarNode(Compile* C, int alias_idx, Node* precedent);
981 virtual int Opcode() const = 0;
982 virtual const class TypePtr *adr_type() const { return _adr_type; }
983 virtual const Type *Value( PhaseTransform *phase ) const;
984 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
985 virtual uint match_edge(uint idx) const { return 0; }
986 virtual const Type *bottom_type() const { return TypeTuple::MEMBAR; }
987 virtual Node *match( const ProjNode *proj, const Matcher *m );
988 // Factory method. Builds a wide or narrow membar.
989 // Optional 'precedent' becomes an extra edge if not null.
990 static MemBarNode* make(Compile* C, int opcode,
991 int alias_idx = Compile::AliasIdxBot,
992 Node* precedent = NULL);
993 };
994
995 // "Acquire" - no following ref can move before (but earlier refs can
996 // follow, like an early Load stalled in cache). Requires multi-cpu
997 // visibility. Inserted after a volatile load.
998 class MemBarAcquireNode: public MemBarNode {
999 public:
1000 MemBarAcquireNode(Compile* C, int alias_idx, Node* precedent)
1001 : MemBarNode(C, alias_idx, precedent) {}
1002 virtual int Opcode() const;
1003 };
1004
1005 // "Acquire" - no following ref can move before (but earlier refs can
1006 // follow, like an early Load stalled in cache). Requires multi-cpu
1007 // visibility. Inserted independ of any load, as required
1008 // for intrinsic sun.misc.Unsafe.loadFence().
1009 class LoadFenceNode: public MemBarNode {
1010 public:
1011 LoadFenceNode(Compile* C, int alias_idx, Node* precedent)
1012 : MemBarNode(C, alias_idx, precedent) {}
1013 virtual int Opcode() const;
1014 };
1015
1016 // "Release" - no earlier ref can move after (but later refs can move
1017 // up, like a speculative pipelined cache-hitting Load). Requires
1018 // multi-cpu visibility. Inserted before a volatile store.
1019 class MemBarReleaseNode: public MemBarNode {
1020 public:
1021 MemBarReleaseNode(Compile* C, int alias_idx, Node* precedent)
1022 : MemBarNode(C, alias_idx, precedent) {}
1023 virtual int Opcode() const;
1024 };
1025
1026 // "Release" - no earlier ref can move after (but later refs can move
1027 // up, like a speculative pipelined cache-hitting Load). Requires
1028 // multi-cpu visibility. Inserted independent of any store, as required
1029 // for intrinsic sun.misc.Unsafe.storeFence().
1030 class StoreFenceNode: public MemBarNode {
1031 public:
1032 StoreFenceNode(Compile* C, int alias_idx, Node* precedent)
1033 : MemBarNode(C, alias_idx, precedent) {}
1034 virtual int Opcode() const;
1035 };
1036
1037 // "Acquire" - no following ref can move before (but earlier refs can
1038 // follow, like an early Load stalled in cache). Requires multi-cpu
1039 // visibility. Inserted after a FastLock.
1040 class MemBarAcquireLockNode: public MemBarNode {
1041 public:
1042 MemBarAcquireLockNode(Compile* C, int alias_idx, Node* precedent)
1043 : MemBarNode(C, alias_idx, precedent) {}
1044 virtual int Opcode() const;
1045 };
1046
1047 // "Release" - no earlier ref can move after (but later refs can move
1048 // up, like a speculative pipelined cache-hitting Load). Requires
1049 // multi-cpu visibility. Inserted before a FastUnLock.
1050 class MemBarReleaseLockNode: public MemBarNode {
1051 public:
1052 MemBarReleaseLockNode(Compile* C, int alias_idx, Node* precedent)
1053 : MemBarNode(C, alias_idx, precedent) {}
1054 virtual int Opcode() const;
1055 };
1056
1057 class MemBarStoreStoreNode: public MemBarNode {
1058 public:
1059 MemBarStoreStoreNode(Compile* C, int alias_idx, Node* precedent)
1060 : MemBarNode(C, alias_idx, precedent) {
1061 init_class_id(Class_MemBarStoreStore);
1062 }
1063 virtual int Opcode() const;
1064 };
1065
1066 // Ordering between a volatile store and a following volatile load.
1067 // Requires multi-CPU visibility?
1068 class MemBarVolatileNode: public MemBarNode {
1069 public:
1070 MemBarVolatileNode(Compile* C, int alias_idx, Node* precedent)
1071 : MemBarNode(C, alias_idx, precedent) {}
1072 virtual int Opcode() const;
1073 };
1074
1075 // Ordering within the same CPU. Used to order unsafe memory references
1076 // inside the compiler when we lack alias info. Not needed "outside" the
1077 // compiler because the CPU does all the ordering for us.
1078 class MemBarCPUOrderNode: public MemBarNode {
1079 public:
1080 MemBarCPUOrderNode(Compile* C, int alias_idx, Node* precedent)
1081 : MemBarNode(C, alias_idx, precedent) {}
1082 virtual int Opcode() const;
1083 virtual uint ideal_reg() const { return 0; } // not matched in the AD file
1084 };
1085
1086 // Isolation of object setup after an AllocateNode and before next safepoint.
1087 // (See comment in memnode.cpp near InitializeNode::InitializeNode for semantics.)
1088 class InitializeNode: public MemBarNode {
1089 friend class AllocateNode;
1090
1091 enum {
1092 Incomplete = 0,
1093 Complete = 1,
1094 WithArraycopy = 2
1095 };
1096 int _is_complete;
1097
1098 bool _does_not_escape;
1099
1100 public:
1101 enum {
1102 Control = TypeFunc::Control,
1103 Memory = TypeFunc::Memory, // MergeMem for states affected by this op
1104 RawAddress = TypeFunc::Parms+0, // the newly-allocated raw address
1105 RawStores = TypeFunc::Parms+1 // zero or more stores (or TOP)
1106 };
1107
1108 InitializeNode(Compile* C, int adr_type, Node* rawoop);
1109 virtual int Opcode() const;
1110 virtual uint size_of() const { return sizeof(*this); }
1111 virtual uint ideal_reg() const { return 0; } // not matched in the AD file
1112 virtual const RegMask &in_RegMask(uint) const; // mask for RawAddress
1113
1114 // Manage incoming memory edges via a MergeMem on in(Memory):
1115 Node* memory(uint alias_idx);
1116
1117 // The raw memory edge coming directly from the Allocation.
1118 // The contents of this memory are *always* all-zero-bits.
1119 Node* zero_memory() { return memory(Compile::AliasIdxRaw); }
1120
1121 // Return the corresponding allocation for this initialization (or null if none).
1122 // (Note: Both InitializeNode::allocation and AllocateNode::initialization
1123 // are defined in graphKit.cpp, which sets up the bidirectional relation.)
1124 AllocateNode* allocation();
1125
1126 // Anything other than zeroing in this init?
1127 bool is_non_zero();
1128
1129 // An InitializeNode must completed before macro expansion is done.
1130 // Completion requires that the AllocateNode must be followed by
1131 // initialization of the new memory to zero, then to any initializers.
1132 bool is_complete() { return _is_complete != Incomplete; }
1133 bool is_complete_with_arraycopy() { return (_is_complete & WithArraycopy) != 0; }
1134
1135 // Mark complete. (Must not yet be complete.)
1136 void set_complete(PhaseGVN* phase);
1137 void set_complete_with_arraycopy() { _is_complete = Complete | WithArraycopy; }
1138
1139 bool does_not_escape() { return _does_not_escape; }
1140 void set_does_not_escape() { _does_not_escape = true; }
1141
1142 #ifdef ASSERT
1143 // ensure all non-degenerate stores are ordered and non-overlapping
1144 bool stores_are_sane(PhaseTransform* phase);
1145 #endif //ASSERT
1146
1147 // See if this store can be captured; return offset where it initializes.
1148 // Return 0 if the store cannot be moved (any sort of problem).
1149 intptr_t can_capture_store(StoreNode* st, PhaseTransform* phase, bool can_reshape);
1150
1151 // Capture another store; reformat it to write my internal raw memory.
1152 // Return the captured copy, else NULL if there is some sort of problem.
1153 Node* capture_store(StoreNode* st, intptr_t start, PhaseTransform* phase, bool can_reshape);
1154
1155 // Find captured store which corresponds to the range [start..start+size).
1156 // Return my own memory projection (meaning the initial zero bits)
1157 // if there is no such store. Return NULL if there is a problem.
1158 Node* find_captured_store(intptr_t start, int size_in_bytes, PhaseTransform* phase);
1159
1160 // Called when the associated AllocateNode is expanded into CFG.
1161 Node* complete_stores(Node* rawctl, Node* rawmem, Node* rawptr,
1162 intptr_t header_size, Node* size_in_bytes,
1163 PhaseGVN* phase);
1164
1165 private:
1166 void remove_extra_zeroes();
1167
1168 // Find out where a captured store should be placed (or already is placed).
1169 int captured_store_insertion_point(intptr_t start, int size_in_bytes,
1170 PhaseTransform* phase);
1171
1172 static intptr_t get_store_offset(Node* st, PhaseTransform* phase);
1173
1174 Node* make_raw_address(intptr_t offset, PhaseTransform* phase);
1175
1176 bool detect_init_independence(Node* n, int& count);
1177
1178 void coalesce_subword_stores(intptr_t header_size, Node* size_in_bytes,
1179 PhaseGVN* phase);
1180
1181 intptr_t find_next_fullword_store(uint i, PhaseGVN* phase);
1182 };
1183
1184 //------------------------------MergeMem---------------------------------------
1185 // (See comment in memnode.cpp near MergeMemNode::MergeMemNode for semantics.)
1186 class MergeMemNode: public Node {
1187 virtual uint hash() const ; // { return NO_HASH; }
1188 virtual uint cmp( const Node &n ) const ; // Always fail, except on self
1189 friend class MergeMemStream;
1190 MergeMemNode(Node* def); // clients use MergeMemNode::make
1191
1192 public:
1193 // If the input is a whole memory state, clone it with all its slices intact.
1194 // Otherwise, make a new memory state with just that base memory input.
1195 // In either case, the result is a newly created MergeMem.
1196 static MergeMemNode* make(Node* base_memory);
1197
1198 virtual int Opcode() const;
1199 virtual Node *Identity( PhaseTransform *phase );
1200 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
1201 virtual uint ideal_reg() const { return NotAMachineReg; }
1202 virtual uint match_edge(uint idx) const { return 0; }
1203 virtual const RegMask &out_RegMask() const;
1204 virtual const Type *bottom_type() const { return Type::MEMORY; }
1205 virtual const TypePtr *adr_type() const { return TypePtr::BOTTOM; }
1206 // sparse accessors
1207 // Fetch the previously stored "set_memory_at", or else the base memory.
1208 // (Caller should clone it if it is a phi-nest.)
1209 Node* memory_at(uint alias_idx) const;
1210 // set the memory, regardless of its previous value
1211 void set_memory_at(uint alias_idx, Node* n);
1212 // the "base" is the memory that provides the non-finite support
1213 Node* base_memory() const { return in(Compile::AliasIdxBot); }
1214 // warning: setting the base can implicitly set any of the other slices too
1215 void set_base_memory(Node* def);
1216 // sentinel value which denotes a copy of the base memory:
1217 Node* empty_memory() const { return in(Compile::AliasIdxTop); }
1218 static Node* make_empty_memory(); // where the sentinel comes from
1219 bool is_empty_memory(Node* n) const { assert((n == empty_memory()) == n->is_top(), "sanity"); return n->is_top(); }
1220 // hook for the iterator, to perform any necessary setup
1221 void iteration_setup(const MergeMemNode* other = NULL);
1222 // push sentinels until I am at least as long as the other (semantic no-op)
1223 void grow_to_match(const MergeMemNode* other);
1224 bool verify_sparse() const PRODUCT_RETURN0;
1225 #ifndef PRODUCT
1226 virtual void dump_spec(outputStream *st) const;
1227 #endif
1228 };
1229
1230 class MergeMemStream : public StackObj {
1231 private:
1232 MergeMemNode* _mm;
1233 const MergeMemNode* _mm2; // optional second guy, contributes non-empty iterations
1234 Node* _mm_base; // loop-invariant base memory of _mm
1235 int _idx;
1236 int _cnt;
1237 Node* _mem;
1238 Node* _mem2;
1239 int _cnt2;
1240
1241 void init(MergeMemNode* mm, const MergeMemNode* mm2 = NULL) {
1242 // subsume_node will break sparseness at times, whenever a memory slice
1243 // folds down to a copy of the base ("fat") memory. In such a case,
1244 // the raw edge will update to base, although it should be top.
1245 // This iterator will recognize either top or base_memory as an
1246 // "empty" slice. See is_empty, is_empty2, and next below.
1247 //
1248 // The sparseness property is repaired in MergeMemNode::Ideal.
1249 // As long as access to a MergeMem goes through this iterator
1250 // or the memory_at accessor, flaws in the sparseness will
1251 // never be observed.
1252 //
1253 // Also, iteration_setup repairs sparseness.
1254 assert(mm->verify_sparse(), "please, no dups of base");
1255 assert(mm2==NULL || mm2->verify_sparse(), "please, no dups of base");
1256
1257 _mm = mm;
1258 _mm_base = mm->base_memory();
1259 _mm2 = mm2;
1260 _cnt = mm->req();
1261 _idx = Compile::AliasIdxBot-1; // start at the base memory
1262 _mem = NULL;
1263 _mem2 = NULL;
1264 }
1265
1266 #ifdef ASSERT
1267 Node* check_memory() const {
1268 if (at_base_memory())
1269 return _mm->base_memory();
1270 else if ((uint)_idx < _mm->req() && !_mm->in(_idx)->is_top())
1271 return _mm->memory_at(_idx);
1272 else
1273 return _mm_base;
1274 }
1275 Node* check_memory2() const {
1276 return at_base_memory()? _mm2->base_memory(): _mm2->memory_at(_idx);
1277 }
1278 #endif
1279
1280 static bool match_memory(Node* mem, const MergeMemNode* mm, int idx) PRODUCT_RETURN0;
1281 void assert_synch() const {
1282 assert(!_mem || _idx >= _cnt || match_memory(_mem, _mm, _idx),
1283 "no side-effects except through the stream");
1284 }
1285
1286 public:
1287
1288 // expected usages:
1289 // for (MergeMemStream mms(mem->is_MergeMem()); next_non_empty(); ) { ... }
1290 // for (MergeMemStream mms(mem1, mem2); next_non_empty2(); ) { ... }
1291
1292 // iterate over one merge
1293 MergeMemStream(MergeMemNode* mm) {
1294 mm->iteration_setup();
1295 init(mm);
1296 debug_only(_cnt2 = 999);
1297 }
1298 // iterate in parallel over two merges
1299 // only iterates through non-empty elements of mm2
1300 MergeMemStream(MergeMemNode* mm, const MergeMemNode* mm2) {
1301 assert(mm2, "second argument must be a MergeMem also");
1302 ((MergeMemNode*)mm2)->iteration_setup(); // update hidden state
1303 mm->iteration_setup(mm2);
1304 init(mm, mm2);
1305 _cnt2 = mm2->req();
1306 }
1307 #ifdef ASSERT
1308 ~MergeMemStream() {
1309 assert_synch();
1310 }
1311 #endif
1312
1313 MergeMemNode* all_memory() const {
1314 return _mm;
1315 }
1316 Node* base_memory() const {
1317 assert(_mm_base == _mm->base_memory(), "no update to base memory, please");
1318 return _mm_base;
1319 }
1320 const MergeMemNode* all_memory2() const {
1321 assert(_mm2 != NULL, "");
1322 return _mm2;
1323 }
1324 bool at_base_memory() const {
1325 return _idx == Compile::AliasIdxBot;
1326 }
1327 int alias_idx() const {
1328 assert(_mem, "must call next 1st");
1329 return _idx;
1330 }
1331
1332 const TypePtr* adr_type() const {
1333 return Compile::current()->get_adr_type(alias_idx());
1334 }
1335
1336 const TypePtr* adr_type(Compile* C) const {
1337 return C->get_adr_type(alias_idx());
1338 }
1339 bool is_empty() const {
1340 assert(_mem, "must call next 1st");
1341 assert(_mem->is_top() == (_mem==_mm->empty_memory()), "correct sentinel");
1342 return _mem->is_top();
1343 }
1344 bool is_empty2() const {
1345 assert(_mem2, "must call next 1st");
1346 assert(_mem2->is_top() == (_mem2==_mm2->empty_memory()), "correct sentinel");
1347 return _mem2->is_top();
1348 }
1349 Node* memory() const {
1350 assert(!is_empty(), "must not be empty");
1351 assert_synch();
1352 return _mem;
1353 }
1354 // get the current memory, regardless of empty or non-empty status
1355 Node* force_memory() const {
1356 assert(!is_empty() || !at_base_memory(), "");
1357 // Use _mm_base to defend against updates to _mem->base_memory().
1358 Node *mem = _mem->is_top() ? _mm_base : _mem;
1359 assert(mem == check_memory(), "");
1360 return mem;
1361 }
1362 Node* memory2() const {
1363 assert(_mem2 == check_memory2(), "");
1364 return _mem2;
1365 }
1366 void set_memory(Node* mem) {
1367 if (at_base_memory()) {
1368 // Note that this does not change the invariant _mm_base.
1369 _mm->set_base_memory(mem);
1370 } else {
1371 _mm->set_memory_at(_idx, mem);
1372 }
1373 _mem = mem;
1374 assert_synch();
1375 }
1376
1377 // Recover from a side effect to the MergeMemNode.
1378 void set_memory() {
1379 _mem = _mm->in(_idx);
1380 }
1381
1382 bool next() { return next(false); }
1383 bool next2() { return next(true); }
1384
1385 bool next_non_empty() { return next_non_empty(false); }
1386 bool next_non_empty2() { return next_non_empty(true); }
1387 // next_non_empty2 can yield states where is_empty() is true
1388
1389 private:
1390 // find the next item, which might be empty
1391 bool next(bool have_mm2) {
1392 assert((_mm2 != NULL) == have_mm2, "use other next");
1393 assert_synch();
1394 if (++_idx < _cnt) {
1395 // Note: This iterator allows _mm to be non-sparse.
1396 // It behaves the same whether _mem is top or base_memory.
1397 _mem = _mm->in(_idx);
1398 if (have_mm2)
1399 _mem2 = _mm2->in((_idx < _cnt2) ? _idx : Compile::AliasIdxTop);
1400 return true;
1401 }
1402 return false;
1403 }
1404
1405 // find the next non-empty item
1406 bool next_non_empty(bool have_mm2) {
1407 while (next(have_mm2)) {
1408 if (!is_empty()) {
1409 // make sure _mem2 is filled in sensibly
1410 if (have_mm2 && _mem2->is_top()) _mem2 = _mm2->base_memory();
1411 return true;
1412 } else if (have_mm2 && !is_empty2()) {
1413 return true; // is_empty() == true
1414 }
1415 }
1416 return false;
1417 }
1418 };
1419
1420 //------------------------------Prefetch---------------------------------------
1421
1422 // Allocation prefetch which may fault, TLAB size have to be adjusted.
1423 class PrefetchAllocationNode : public Node {
1424 public:
1425 PrefetchAllocationNode(Node *mem, Node *adr) : Node(0,mem,adr) {}
1426 virtual int Opcode() const;
1427 virtual uint ideal_reg() const { return NotAMachineReg; }
1428 virtual uint match_edge(uint idx) const { return idx==2; }
1429 virtual const Type *bottom_type() const { return ( AllocatePrefetchStyle == 3 ) ? Type::MEMORY : Type::ABIO; }
1430 };
1431
1432 #endif // SHARE_VM_OPTO_MEMNODE_HPP