1 /*
2 * Copyright (c) 2005, 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).
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.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "ci/bcEscapeAnalyzer.hpp"
27 #include "compiler/compileLog.hpp"
28 #include "libadt/vectset.hpp"
29 #include "memory/allocation.hpp"
30 #include "opto/c2compiler.hpp"
31 #include "opto/callnode.hpp"
32 #include "opto/cfgnode.hpp"
33 #include "opto/compile.hpp"
34 #include "opto/escape.hpp"
35 #include "opto/phaseX.hpp"
36 #include "opto/movenode.hpp"
37 #include "opto/rootnode.hpp"
38
39 ConnectionGraph::ConnectionGraph(Compile * C, PhaseIterGVN *igvn) :
40 _nodes(C->comp_arena(), C->unique(), C->unique(), NULL),
41 _collecting(true),
42 _verify(false),
43 _compile(C),
44 _igvn(igvn),
45 _node_map(C->comp_arena()) {
46 // Add unknown java object.
47 add_java_object(C->top(), PointsToNode::GlobalEscape);
48 phantom_obj = ptnode_adr(C->top()->_idx)->as_JavaObject();
49 // Add ConP(#NULL) and ConN(#NULL) nodes.
50 Node* oop_null = igvn->zerocon(T_OBJECT);
51 assert(oop_null->_idx < nodes_size(), "should be created already");
52 add_java_object(oop_null, PointsToNode::NoEscape);
53 null_obj = ptnode_adr(oop_null->_idx)->as_JavaObject();
54 if (UseCompressedOops) {
55 Node* noop_null = igvn->zerocon(T_NARROWOOP);
56 assert(noop_null->_idx < nodes_size(), "should be created already");
57 map_ideal_node(noop_null, null_obj);
58 }
59 _pcmp_neq = NULL; // Should be initialized
60 _pcmp_eq = NULL;
61 }
62
63 bool ConnectionGraph::has_candidates(Compile *C) {
64 // EA brings benefits only when the code has allocations and/or locks which
65 // are represented by ideal Macro nodes.
66 int cnt = C->macro_count();
67 for (int i = 0; i < cnt; i++) {
68 Node *n = C->macro_node(i);
69 if (n->is_Allocate())
70 return true;
71 if (n->is_Lock()) {
72 Node* obj = n->as_Lock()->obj_node()->uncast();
73 if (!(obj->is_Parm() || obj->is_Con()))
74 return true;
75 }
76 if (n->is_CallStaticJava() &&
77 n->as_CallStaticJava()->is_boxing_method()) {
78 return true;
79 }
80 }
81 return false;
82 }
83
84 void ConnectionGraph::do_analysis(Compile *C, PhaseIterGVN *igvn) {
85 Compile::TracePhase t2("escapeAnalysis", &Phase::_t_escapeAnalysis, true);
86 ResourceMark rm;
87
88 // Add ConP#NULL and ConN#NULL nodes before ConnectionGraph construction
89 // to create space for them in ConnectionGraph::_nodes[].
90 Node* oop_null = igvn->zerocon(T_OBJECT);
91 Node* noop_null = igvn->zerocon(T_NARROWOOP);
92 ConnectionGraph* congraph = new(C->comp_arena()) ConnectionGraph(C, igvn);
93 // Perform escape analysis
94 if (congraph->compute_escape()) {
95 // There are non escaping objects.
96 C->set_congraph(congraph);
97 }
98 // Cleanup.
99 if (oop_null->outcnt() == 0)
100 igvn->hash_delete(oop_null);
101 if (noop_null->outcnt() == 0)
102 igvn->hash_delete(noop_null);
103 }
104
105 bool ConnectionGraph::compute_escape() {
106 Compile* C = _compile;
107 PhaseGVN* igvn = _igvn;
108
109 // Worklists used by EA.
110 Unique_Node_List delayed_worklist;
111 GrowableArray<Node*> alloc_worklist;
112 GrowableArray<Node*> ptr_cmp_worklist;
113 GrowableArray<Node*> storestore_worklist;
114 GrowableArray<PointsToNode*> ptnodes_worklist;
115 GrowableArray<JavaObjectNode*> java_objects_worklist;
116 GrowableArray<JavaObjectNode*> non_escaped_worklist;
117 GrowableArray<FieldNode*> oop_fields_worklist;
118 DEBUG_ONLY( GrowableArray<Node*> addp_worklist; )
119
120 { Compile::TracePhase t3("connectionGraph", &Phase::_t_connectionGraph, true);
121
122 // 1. Populate Connection Graph (CG) with PointsTo nodes.
123 ideal_nodes.map(C->live_nodes(), NULL); // preallocate space
124 // Initialize worklist
125 if (C->root() != NULL) {
126 ideal_nodes.push(C->root());
127 }
128 for( uint next = 0; next < ideal_nodes.size(); ++next ) {
129 Node* n = ideal_nodes.at(next);
130 // Create PointsTo nodes and add them to Connection Graph. Called
131 // only once per ideal node since ideal_nodes is Unique_Node list.
132 add_node_to_connection_graph(n, &delayed_worklist);
133 PointsToNode* ptn = ptnode_adr(n->_idx);
134 if (ptn != NULL) {
135 ptnodes_worklist.append(ptn);
136 if (ptn->is_JavaObject()) {
137 java_objects_worklist.append(ptn->as_JavaObject());
138 if ((n->is_Allocate() || n->is_CallStaticJava()) &&
139 (ptn->escape_state() < PointsToNode::GlobalEscape)) {
140 // Only allocations and java static calls results are interesting.
141 non_escaped_worklist.append(ptn->as_JavaObject());
142 }
143 } else if (ptn->is_Field() && ptn->as_Field()->is_oop()) {
144 oop_fields_worklist.append(ptn->as_Field());
145 }
146 }
147 if (n->is_MergeMem()) {
148 // Collect all MergeMem nodes to add memory slices for
149 // scalar replaceable objects in split_unique_types().
150 _mergemem_worklist.append(n->as_MergeMem());
151 } else if (OptimizePtrCompare && n->is_Cmp() &&
152 (n->Opcode() == Op_CmpP || n->Opcode() == Op_CmpN)) {
153 // Collect compare pointers nodes.
154 ptr_cmp_worklist.append(n);
155 } else if (n->is_MemBarStoreStore()) {
156 // Collect all MemBarStoreStore nodes so that depending on the
157 // escape status of the associated Allocate node some of them
158 // may be eliminated.
159 storestore_worklist.append(n);
160 } else if (n->is_MemBar() && (n->Opcode() == Op_MemBarRelease) &&
161 (n->req() > MemBarNode::Precedent)) {
162 record_for_optimizer(n);
163 #ifdef ASSERT
164 } else if (n->is_AddP()) {
165 // Collect address nodes for graph verification.
166 addp_worklist.append(n);
167 #endif
168 }
169 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
170 Node* m = n->fast_out(i); // Get user
171 ideal_nodes.push(m);
172 }
173 }
174 if (non_escaped_worklist.length() == 0) {
175 _collecting = false;
176 return false; // Nothing to do.
177 }
178 // Add final simple edges to graph.
179 while(delayed_worklist.size() > 0) {
180 Node* n = delayed_worklist.pop();
181 add_final_edges(n);
182 }
183 int ptnodes_length = ptnodes_worklist.length();
184
185 #ifdef ASSERT
186 if (VerifyConnectionGraph) {
187 // Verify that no new simple edges could be created and all
188 // local vars has edges.
189 _verify = true;
190 for (int next = 0; next < ptnodes_length; ++next) {
191 PointsToNode* ptn = ptnodes_worklist.at(next);
192 add_final_edges(ptn->ideal_node());
193 if (ptn->is_LocalVar() && ptn->edge_count() == 0) {
194 ptn->dump();
195 assert(ptn->as_LocalVar()->edge_count() > 0, "sanity");
196 }
197 }
198 _verify = false;
199 }
200 #endif
201
202 // 2. Finish Graph construction by propagating references to all
203 // java objects through graph.
204 if (!complete_connection_graph(ptnodes_worklist, non_escaped_worklist,
205 java_objects_worklist, oop_fields_worklist)) {
206 // All objects escaped or hit time or iterations limits.
207 _collecting = false;
208 return false;
209 }
210
211 // 3. Adjust scalar_replaceable state of nonescaping objects and push
212 // scalar replaceable allocations on alloc_worklist for processing
213 // in split_unique_types().
214 int non_escaped_length = non_escaped_worklist.length();
215 for (int next = 0; next < non_escaped_length; next++) {
216 JavaObjectNode* ptn = non_escaped_worklist.at(next);
217 bool noescape = (ptn->escape_state() == PointsToNode::NoEscape);
218 Node* n = ptn->ideal_node();
219 if (n->is_Allocate()) {
220 n->as_Allocate()->_is_non_escaping = noescape;
221 }
222 if (n->is_CallStaticJava()) {
223 n->as_CallStaticJava()->_is_non_escaping = noescape;
224 }
225 if (noescape && ptn->scalar_replaceable()) {
226 adjust_scalar_replaceable_state(ptn);
227 if (ptn->scalar_replaceable()) {
228 alloc_worklist.append(ptn->ideal_node());
229 }
230 }
231 }
232
233 #ifdef ASSERT
234 if (VerifyConnectionGraph) {
235 // Verify that graph is complete - no new edges could be added or needed.
236 verify_connection_graph(ptnodes_worklist, non_escaped_worklist,
237 java_objects_worklist, addp_worklist);
238 }
239 assert(C->unique() == nodes_size(), "no new ideal nodes should be added during ConnectionGraph build");
240 assert(null_obj->escape_state() == PointsToNode::NoEscape &&
241 null_obj->edge_count() == 0 &&
242 !null_obj->arraycopy_src() &&
243 !null_obj->arraycopy_dst(), "sanity");
244 #endif
245
246 _collecting = false;
247
248 } // TracePhase t3("connectionGraph")
249
250 // 4. Optimize ideal graph based on EA information.
251 bool has_non_escaping_obj = (non_escaped_worklist.length() > 0);
252 if (has_non_escaping_obj) {
253 optimize_ideal_graph(ptr_cmp_worklist, storestore_worklist);
254 }
255
256 #ifndef PRODUCT
257 if (PrintEscapeAnalysis) {
258 dump(ptnodes_worklist); // Dump ConnectionGraph
259 }
260 #endif
261
262 bool has_scalar_replaceable_candidates = (alloc_worklist.length() > 0);
263 #ifdef ASSERT
264 if (VerifyConnectionGraph) {
265 int alloc_length = alloc_worklist.length();
266 for (int next = 0; next < alloc_length; ++next) {
267 Node* n = alloc_worklist.at(next);
268 PointsToNode* ptn = ptnode_adr(n->_idx);
269 assert(ptn->escape_state() == PointsToNode::NoEscape && ptn->scalar_replaceable(), "sanity");
270 }
271 }
272 #endif
273
274 // 5. Separate memory graph for scalar replaceable allcations.
275 if (has_scalar_replaceable_candidates &&
276 C->AliasLevel() >= 3 && EliminateAllocations) {
277 // Now use the escape information to create unique types for
278 // scalar replaceable objects.
279 split_unique_types(alloc_worklist);
280 if (C->failing()) return false;
281 C->print_method(PHASE_AFTER_EA, 2);
282
283 #ifdef ASSERT
284 } else if (Verbose && (PrintEscapeAnalysis || PrintEliminateAllocations)) {
285 tty->print("=== No allocations eliminated for ");
286 C->method()->print_short_name();
287 if(!EliminateAllocations) {
288 tty->print(" since EliminateAllocations is off ===");
289 } else if(!has_scalar_replaceable_candidates) {
290 tty->print(" since there are no scalar replaceable candidates ===");
291 } else if(C->AliasLevel() < 3) {
292 tty->print(" since AliasLevel < 3 ===");
293 }
294 tty->cr();
295 #endif
296 }
297 return has_non_escaping_obj;
298 }
299
300 // Utility function for nodes that load an object
301 void ConnectionGraph::add_objload_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
302 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
303 // ThreadLocal has RawPtr type.
304 const Type* t = _igvn->type(n);
305 if (t->make_ptr() != NULL) {
306 Node* adr = n->in(MemNode::Address);
307 #ifdef ASSERT
308 if (!adr->is_AddP()) {
309 assert(_igvn->type(adr)->isa_rawptr(), "sanity");
310 } else {
311 assert((ptnode_adr(adr->_idx) == NULL ||
312 ptnode_adr(adr->_idx)->as_Field()->is_oop()), "sanity");
313 }
314 #endif
315 add_local_var_and_edge(n, PointsToNode::NoEscape,
316 adr, delayed_worklist);
317 }
318 }
319
320 // Populate Connection Graph with PointsTo nodes and create simple
321 // connection graph edges.
322 void ConnectionGraph::add_node_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
323 assert(!_verify, "this method sould not be called for verification");
324 PhaseGVN* igvn = _igvn;
325 uint n_idx = n->_idx;
326 PointsToNode* n_ptn = ptnode_adr(n_idx);
327 if (n_ptn != NULL)
328 return; // No need to redefine PointsTo node during first iteration.
329
330 if (n->is_Call()) {
331 // Arguments to allocation and locking don't escape.
332 if (n->is_AbstractLock()) {
333 // Put Lock and Unlock nodes on IGVN worklist to process them during
334 // first IGVN optimization when escape information is still available.
335 record_for_optimizer(n);
336 } else if (n->is_Allocate()) {
337 add_call_node(n->as_Call());
338 record_for_optimizer(n);
339 } else {
340 if (n->is_CallStaticJava()) {
341 const char* name = n->as_CallStaticJava()->_name;
342 if (name != NULL && strcmp(name, "uncommon_trap") == 0)
343 return; // Skip uncommon traps
344 }
345 // Don't mark as processed since call's arguments have to be processed.
346 delayed_worklist->push(n);
347 // Check if a call returns an object.
348 if ((n->as_Call()->returns_pointer() &&
349 n->as_Call()->proj_out(TypeFunc::Parms) != NULL) ||
350 (n->is_CallStaticJava() &&
351 n->as_CallStaticJava()->is_boxing_method())) {
352 add_call_node(n->as_Call());
353 }
354 }
355 return;
356 }
357 // Put this check here to process call arguments since some call nodes
358 // point to phantom_obj.
359 if (n_ptn == phantom_obj || n_ptn == null_obj)
360 return; // Skip predefined nodes.
361
362 int opcode = n->Opcode();
363 switch (opcode) {
364 case Op_AddP: {
365 Node* base = get_addp_base(n);
366 PointsToNode* ptn_base = ptnode_adr(base->_idx);
367 // Field nodes are created for all field types. They are used in
368 // adjust_scalar_replaceable_state() and split_unique_types().
369 // Note, non-oop fields will have only base edges in Connection
370 // Graph because such fields are not used for oop loads and stores.
371 int offset = address_offset(n, igvn);
372 add_field(n, PointsToNode::NoEscape, offset);
373 if (ptn_base == NULL) {
374 delayed_worklist->push(n); // Process it later.
375 } else {
376 n_ptn = ptnode_adr(n_idx);
377 add_base(n_ptn->as_Field(), ptn_base);
378 }
379 break;
380 }
381 case Op_CastX2P: {
382 map_ideal_node(n, phantom_obj);
383 break;
384 }
385 case Op_CastPP:
386 case Op_CheckCastPP:
387 case Op_EncodeP:
388 case Op_DecodeN:
389 case Op_EncodePKlass:
390 case Op_DecodeNKlass: {
391 add_local_var_and_edge(n, PointsToNode::NoEscape,
392 n->in(1), delayed_worklist);
393 break;
394 }
395 case Op_CMoveP: {
396 add_local_var(n, PointsToNode::NoEscape);
397 // Do not add edges during first iteration because some could be
398 // not defined yet.
399 delayed_worklist->push(n);
400 break;
401 }
402 case Op_ConP:
403 case Op_ConN:
404 case Op_ConNKlass: {
405 // assume all oop constants globally escape except for null
406 PointsToNode::EscapeState es;
407 const Type* t = igvn->type(n);
408 if (t == TypePtr::NULL_PTR || t == TypeNarrowOop::NULL_PTR) {
409 es = PointsToNode::NoEscape;
410 } else {
411 es = PointsToNode::GlobalEscape;
412 }
413 add_java_object(n, es);
414 break;
415 }
416 case Op_CreateEx: {
417 // assume that all exception objects globally escape
418 add_java_object(n, PointsToNode::GlobalEscape);
419 break;
420 }
421 case Op_LoadKlass:
422 case Op_LoadNKlass: {
423 // Unknown class is loaded
424 map_ideal_node(n, phantom_obj);
425 break;
426 }
427 case Op_LoadP:
428 case Op_LoadN:
429 case Op_LoadPLocked: {
430 add_objload_to_connection_graph(n, delayed_worklist);
431 break;
432 }
433 case Op_Parm: {
434 map_ideal_node(n, phantom_obj);
435 break;
436 }
437 case Op_PartialSubtypeCheck: {
438 // Produces Null or notNull and is used in only in CmpP so
439 // phantom_obj could be used.
440 map_ideal_node(n, phantom_obj); // Result is unknown
441 break;
442 }
443 case Op_Phi: {
444 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
445 // ThreadLocal has RawPtr type.
446 const Type* t = n->as_Phi()->type();
447 if (t->make_ptr() != NULL) {
448 add_local_var(n, PointsToNode::NoEscape);
449 // Do not add edges during first iteration because some could be
450 // not defined yet.
451 delayed_worklist->push(n);
452 }
453 break;
454 }
455 case Op_Proj: {
456 // we are only interested in the oop result projection from a call
457 if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
458 n->in(0)->as_Call()->returns_pointer()) {
459 add_local_var_and_edge(n, PointsToNode::NoEscape,
460 n->in(0), delayed_worklist);
461 }
462 break;
463 }
464 case Op_Rethrow: // Exception object escapes
465 case Op_Return: {
466 if (n->req() > TypeFunc::Parms &&
467 igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
468 // Treat Return value as LocalVar with GlobalEscape escape state.
469 add_local_var_and_edge(n, PointsToNode::GlobalEscape,
470 n->in(TypeFunc::Parms), delayed_worklist);
471 }
472 break;
473 }
474 case Op_GetAndSetP:
475 case Op_GetAndSetN: {
476 add_objload_to_connection_graph(n, delayed_worklist);
477 // fallthrough
478 }
479 case Op_StoreP:
480 case Op_StoreN:
481 case Op_StoreNKlass:
482 case Op_StorePConditional:
483 case Op_CompareAndSwapP:
484 case Op_CompareAndSwapN: {
485 Node* adr = n->in(MemNode::Address);
486 const Type *adr_type = igvn->type(adr);
487 adr_type = adr_type->make_ptr();
488 if (adr_type == NULL) {
489 break; // skip dead nodes
490 }
491 if (adr_type->isa_oopptr() ||
492 (opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass) &&
493 (adr_type == TypeRawPtr::NOTNULL &&
494 adr->in(AddPNode::Address)->is_Proj() &&
495 adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
496 delayed_worklist->push(n); // Process it later.
497 #ifdef ASSERT
498 assert(adr->is_AddP(), "expecting an AddP");
499 if (adr_type == TypeRawPtr::NOTNULL) {
500 // Verify a raw address for a store captured by Initialize node.
501 int offs = (int)igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
502 assert(offs != Type::OffsetBot, "offset must be a constant");
503 }
504 #endif
505 } else {
506 // Ignore copy the displaced header to the BoxNode (OSR compilation).
507 if (adr->is_BoxLock())
508 break;
509 // Stored value escapes in unsafe access.
510 if ((opcode == Op_StoreP) && (adr_type == TypeRawPtr::BOTTOM)) {
511 // Pointer stores in G1 barriers looks like unsafe access.
512 // Ignore such stores to be able scalar replace non-escaping
513 // allocations.
514 if (UseG1GC && adr->is_AddP()) {
515 Node* base = get_addp_base(adr);
516 if (base->Opcode() == Op_LoadP &&
517 base->in(MemNode::Address)->is_AddP()) {
518 adr = base->in(MemNode::Address);
519 Node* tls = get_addp_base(adr);
520 if (tls->Opcode() == Op_ThreadLocal) {
521 int offs = (int)igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
522 if (offs == in_bytes(JavaThread::satb_mark_queue_offset() +
523 PtrQueue::byte_offset_of_buf())) {
524 break; // G1 pre barier previous oop value store.
525 }
526 if (offs == in_bytes(JavaThread::dirty_card_queue_offset() +
527 PtrQueue::byte_offset_of_buf())) {
528 break; // G1 post barier card address store.
529 }
530 }
531 }
532 }
533 delayed_worklist->push(n); // Process unsafe access later.
534 break;
535 }
536 #ifdef ASSERT
537 n->dump(1);
538 assert(false, "not unsafe or G1 barrier raw StoreP");
539 #endif
540 }
541 break;
542 }
543 case Op_AryEq:
544 case Op_StrComp:
545 case Op_StrEquals:
546 case Op_StrIndexOf:
547 case Op_EncodeISOArray: {
548 add_local_var(n, PointsToNode::ArgEscape);
549 delayed_worklist->push(n); // Process it later.
550 break;
551 }
552 case Op_ThreadLocal: {
553 add_java_object(n, PointsToNode::ArgEscape);
554 break;
555 }
556 default:
557 ; // Do nothing for nodes not related to EA.
558 }
559 return;
560 }
561
562 #ifdef ASSERT
563 #define ELSE_FAIL(name) \
564 /* Should not be called for not pointer type. */ \
565 n->dump(1); \
566 assert(false, name); \
567 break;
568 #else
569 #define ELSE_FAIL(name) \
570 break;
571 #endif
572
573 // Add final simple edges to graph.
574 void ConnectionGraph::add_final_edges(Node *n) {
575 PointsToNode* n_ptn = ptnode_adr(n->_idx);
576 #ifdef ASSERT
577 if (_verify && n_ptn->is_JavaObject())
578 return; // This method does not change graph for JavaObject.
579 #endif
580
581 if (n->is_Call()) {
582 process_call_arguments(n->as_Call());
583 return;
584 }
585 assert(n->is_Store() || n->is_LoadStore() ||
586 (n_ptn != NULL) && (n_ptn->ideal_node() != NULL),
587 "node should be registered already");
588 int opcode = n->Opcode();
589 switch (opcode) {
590 case Op_AddP: {
591 Node* base = get_addp_base(n);
592 PointsToNode* ptn_base = ptnode_adr(base->_idx);
593 assert(ptn_base != NULL, "field's base should be registered");
594 add_base(n_ptn->as_Field(), ptn_base);
595 break;
596 }
597 case Op_CastPP:
598 case Op_CheckCastPP:
599 case Op_EncodeP:
600 case Op_DecodeN:
601 case Op_EncodePKlass:
602 case Op_DecodeNKlass: {
603 add_local_var_and_edge(n, PointsToNode::NoEscape,
604 n->in(1), NULL);
605 break;
606 }
607 case Op_CMoveP: {
608 for (uint i = CMoveNode::IfFalse; i < n->req(); i++) {
609 Node* in = n->in(i);
610 if (in == NULL)
611 continue; // ignore NULL
612 Node* uncast_in = in->uncast();
613 if (uncast_in->is_top() || uncast_in == n)
614 continue; // ignore top or inputs which go back this node
615 PointsToNode* ptn = ptnode_adr(in->_idx);
616 assert(ptn != NULL, "node should be registered");
617 add_edge(n_ptn, ptn);
618 }
619 break;
620 }
621 case Op_LoadP:
622 case Op_LoadN:
623 case Op_LoadPLocked: {
624 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
625 // ThreadLocal has RawPtr type.
626 const Type* t = _igvn->type(n);
627 if (t->make_ptr() != NULL) {
628 Node* adr = n->in(MemNode::Address);
629 add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
630 break;
631 }
632 ELSE_FAIL("Op_LoadP");
633 }
634 case Op_Phi: {
635 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
636 // ThreadLocal has RawPtr type.
637 const Type* t = n->as_Phi()->type();
638 if (t->make_ptr() != NULL) {
639 for (uint i = 1; i < n->req(); i++) {
640 Node* in = n->in(i);
641 if (in == NULL)
642 continue; // ignore NULL
643 Node* uncast_in = in->uncast();
644 if (uncast_in->is_top() || uncast_in == n)
645 continue; // ignore top or inputs which go back this node
646 PointsToNode* ptn = ptnode_adr(in->_idx);
647 assert(ptn != NULL, "node should be registered");
648 add_edge(n_ptn, ptn);
649 }
650 break;
651 }
652 ELSE_FAIL("Op_Phi");
653 }
654 case Op_Proj: {
655 // we are only interested in the oop result projection from a call
656 if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
657 n->in(0)->as_Call()->returns_pointer()) {
658 add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(0), NULL);
659 break;
660 }
661 ELSE_FAIL("Op_Proj");
662 }
663 case Op_Rethrow: // Exception object escapes
664 case Op_Return: {
665 if (n->req() > TypeFunc::Parms &&
666 _igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
667 // Treat Return value as LocalVar with GlobalEscape escape state.
668 add_local_var_and_edge(n, PointsToNode::GlobalEscape,
669 n->in(TypeFunc::Parms), NULL);
670 break;
671 }
672 ELSE_FAIL("Op_Return");
673 }
674 case Op_StoreP:
675 case Op_StoreN:
676 case Op_StoreNKlass:
677 case Op_StorePConditional:
678 case Op_CompareAndSwapP:
679 case Op_CompareAndSwapN:
680 case Op_GetAndSetP:
681 case Op_GetAndSetN: {
682 Node* adr = n->in(MemNode::Address);
683 const Type *adr_type = _igvn->type(adr);
684 adr_type = adr_type->make_ptr();
685 #ifdef ASSERT
686 if (adr_type == NULL) {
687 n->dump(1);
688 assert(adr_type != NULL, "dead node should not be on list");
689 break;
690 }
691 #endif
692 if (opcode == Op_GetAndSetP || opcode == Op_GetAndSetN) {
693 add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
694 }
695 if (adr_type->isa_oopptr() ||
696 (opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass) &&
697 (adr_type == TypeRawPtr::NOTNULL &&
698 adr->in(AddPNode::Address)->is_Proj() &&
699 adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
700 // Point Address to Value
701 PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
702 assert(adr_ptn != NULL &&
703 adr_ptn->as_Field()->is_oop(), "node should be registered");
704 Node *val = n->in(MemNode::ValueIn);
705 PointsToNode* ptn = ptnode_adr(val->_idx);
706 assert(ptn != NULL, "node should be registered");
707 add_edge(adr_ptn, ptn);
708 break;
709 } else if ((opcode == Op_StoreP) && (adr_type == TypeRawPtr::BOTTOM)) {
710 // Stored value escapes in unsafe access.
711 Node *val = n->in(MemNode::ValueIn);
712 PointsToNode* ptn = ptnode_adr(val->_idx);
713 assert(ptn != NULL, "node should be registered");
714 ptn->set_escape_state(PointsToNode::GlobalEscape);
715 // Add edge to object for unsafe access with offset.
716 PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
717 assert(adr_ptn != NULL, "node should be registered");
718 if (adr_ptn->is_Field()) {
719 assert(adr_ptn->as_Field()->is_oop(), "should be oop field");
720 add_edge(adr_ptn, ptn);
721 }
722 break;
723 }
724 ELSE_FAIL("Op_StoreP");
725 }
726 case Op_AryEq:
727 case Op_StrComp:
728 case Op_StrEquals:
729 case Op_StrIndexOf:
730 case Op_EncodeISOArray: {
731 // char[] arrays passed to string intrinsic do not escape but
732 // they are not scalar replaceable. Adjust escape state for them.
733 // Start from in(2) edge since in(1) is memory edge.
734 for (uint i = 2; i < n->req(); i++) {
735 Node* adr = n->in(i);
736 const Type* at = _igvn->type(adr);
737 if (!adr->is_top() && at->isa_ptr()) {
738 assert(at == Type::TOP || at == TypePtr::NULL_PTR ||
739 at->isa_ptr() != NULL, "expecting a pointer");
740 if (adr->is_AddP()) {
741 adr = get_addp_base(adr);
742 }
743 PointsToNode* ptn = ptnode_adr(adr->_idx);
744 assert(ptn != NULL, "node should be registered");
745 add_edge(n_ptn, ptn);
746 }
747 }
748 break;
749 }
750 default: {
751 // This method should be called only for EA specific nodes which may
752 // miss some edges when they were created.
753 #ifdef ASSERT
754 n->dump(1);
755 #endif
756 guarantee(false, "unknown node");
757 }
758 }
759 return;
760 }
761
762 void ConnectionGraph::add_call_node(CallNode* call) {
763 assert(call->returns_pointer(), "only for call which returns pointer");
764 uint call_idx = call->_idx;
765 if (call->is_Allocate()) {
766 Node* k = call->in(AllocateNode::KlassNode);
767 const TypeKlassPtr* kt = k->bottom_type()->isa_klassptr();
768 assert(kt != NULL, "TypeKlassPtr required.");
769 ciKlass* cik = kt->klass();
770 PointsToNode::EscapeState es = PointsToNode::NoEscape;
771 bool scalar_replaceable = true;
772 if (call->is_AllocateArray()) {
773 if (!cik->is_array_klass()) { // StressReflectiveCode
774 es = PointsToNode::GlobalEscape;
775 } else {
776 int length = call->in(AllocateNode::ALength)->find_int_con(-1);
777 if (length < 0 || length > EliminateAllocationArraySizeLimit) {
778 // Not scalar replaceable if the length is not constant or too big.
779 scalar_replaceable = false;
780 }
781 }
782 } else { // Allocate instance
783 if (cik->is_subclass_of(_compile->env()->Thread_klass()) ||
784 cik->is_subclass_of(_compile->env()->Reference_klass()) ||
785 !cik->is_instance_klass() || // StressReflectiveCode
786 cik->as_instance_klass()->has_finalizer()) {
787 es = PointsToNode::GlobalEscape;
788 }
789 }
790 add_java_object(call, es);
791 PointsToNode* ptn = ptnode_adr(call_idx);
792 if (!scalar_replaceable && ptn->scalar_replaceable()) {
793 ptn->set_scalar_replaceable(false);
794 }
795 } else if (call->is_CallStaticJava()) {
796 // Call nodes could be different types:
797 //
798 // 1. CallDynamicJavaNode (what happened during call is unknown):
799 //
800 // - mapped to GlobalEscape JavaObject node if oop is returned;
801 //
802 // - all oop arguments are escaping globally;
803 //
804 // 2. CallStaticJavaNode (execute bytecode analysis if possible):
805 //
806 // - the same as CallDynamicJavaNode if can't do bytecode analysis;
807 //
808 // - mapped to GlobalEscape JavaObject node if unknown oop is returned;
809 // - mapped to NoEscape JavaObject node if non-escaping object allocated
810 // during call is returned;
811 // - mapped to ArgEscape LocalVar node pointed to object arguments
812 // which are returned and does not escape during call;
813 //
814 // - oop arguments escaping status is defined by bytecode analysis;
815 //
816 // For a static call, we know exactly what method is being called.
817 // Use bytecode estimator to record whether the call's return value escapes.
818 ciMethod* meth = call->as_CallJava()->method();
819 if (meth == NULL) {
820 const char* name = call->as_CallStaticJava()->_name;
821 assert(strncmp(name, "_multianewarray", 15) == 0, "TODO: add failed case check");
822 // Returns a newly allocated unescaped object.
823 add_java_object(call, PointsToNode::NoEscape);
824 ptnode_adr(call_idx)->set_scalar_replaceable(false);
825 } else if (meth->is_boxing_method()) {
826 // Returns boxing object
827 PointsToNode::EscapeState es;
828 vmIntrinsics::ID intr = meth->intrinsic_id();
829 if (intr == vmIntrinsics::_floatValue || intr == vmIntrinsics::_doubleValue) {
830 // It does not escape if object is always allocated.
831 es = PointsToNode::NoEscape;
832 } else {
833 // It escapes globally if object could be loaded from cache.
834 es = PointsToNode::GlobalEscape;
835 }
836 add_java_object(call, es);
837 } else {
838 BCEscapeAnalyzer* call_analyzer = meth->get_bcea();
839 call_analyzer->copy_dependencies(_compile->dependencies());
840 if (call_analyzer->is_return_allocated()) {
841 // Returns a newly allocated unescaped object, simply
842 // update dependency information.
843 // Mark it as NoEscape so that objects referenced by
844 // it's fields will be marked as NoEscape at least.
845 add_java_object(call, PointsToNode::NoEscape);
846 ptnode_adr(call_idx)->set_scalar_replaceable(false);
847 } else {
848 // Determine whether any arguments are returned.
849 const TypeTuple* d = call->tf()->domain();
850 bool ret_arg = false;
851 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
852 if (d->field_at(i)->isa_ptr() != NULL &&
853 call_analyzer->is_arg_returned(i - TypeFunc::Parms)) {
854 ret_arg = true;
855 break;
856 }
857 }
858 if (ret_arg) {
859 add_local_var(call, PointsToNode::ArgEscape);
860 } else {
861 // Returns unknown object.
862 map_ideal_node(call, phantom_obj);
863 }
864 }
865 }
866 } else {
867 // An other type of call, assume the worst case:
868 // returned value is unknown and globally escapes.
869 assert(call->Opcode() == Op_CallDynamicJava, "add failed case check");
870 map_ideal_node(call, phantom_obj);
871 }
872 }
873
874 void ConnectionGraph::process_call_arguments(CallNode *call) {
875 bool is_arraycopy = false;
876 switch (call->Opcode()) {
877 #ifdef ASSERT
878 case Op_Allocate:
879 case Op_AllocateArray:
880 case Op_Lock:
881 case Op_Unlock:
882 assert(false, "should be done already");
883 break;
884 #endif
885 case Op_CallLeafNoFP:
886 is_arraycopy = (call->as_CallLeaf()->_name != NULL &&
887 strstr(call->as_CallLeaf()->_name, "arraycopy") != 0);
888 // fall through
889 case Op_CallLeaf: {
890 // Stub calls, objects do not escape but they are not scale replaceable.
891 // Adjust escape state for outgoing arguments.
892 const TypeTuple * d = call->tf()->domain();
893 bool src_has_oops = false;
894 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
895 const Type* at = d->field_at(i);
896 Node *arg = call->in(i);
897 const Type *aat = _igvn->type(arg);
898 if (arg->is_top() || !at->isa_ptr() || !aat->isa_ptr())
899 continue;
900 if (arg->is_AddP()) {
901 //
902 // The inline_native_clone() case when the arraycopy stub is called
903 // after the allocation before Initialize and CheckCastPP nodes.
904 // Or normal arraycopy for object arrays case.
905 //
906 // Set AddP's base (Allocate) as not scalar replaceable since
907 // pointer to the base (with offset) is passed as argument.
908 //
909 arg = get_addp_base(arg);
910 }
911 PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
912 assert(arg_ptn != NULL, "should be registered");
913 PointsToNode::EscapeState arg_esc = arg_ptn->escape_state();
914 if (is_arraycopy || arg_esc < PointsToNode::ArgEscape) {
915 assert(aat == Type::TOP || aat == TypePtr::NULL_PTR ||
916 aat->isa_ptr() != NULL, "expecting an Ptr");
917 bool arg_has_oops = aat->isa_oopptr() &&
918 (aat->isa_oopptr()->klass() == NULL || aat->isa_instptr() ||
919 (aat->isa_aryptr() && aat->isa_aryptr()->klass()->is_obj_array_klass()));
920 if (i == TypeFunc::Parms) {
921 src_has_oops = arg_has_oops;
922 }
923 //
924 // src or dst could be j.l.Object when other is basic type array:
925 //
926 // arraycopy(char[],0,Object*,0,size);
927 // arraycopy(Object*,0,char[],0,size);
928 //
929 // Don't add edges in such cases.
930 //
931 bool arg_is_arraycopy_dest = src_has_oops && is_arraycopy &&
932 arg_has_oops && (i > TypeFunc::Parms);
933 #ifdef ASSERT
934 if (!(is_arraycopy ||
935 (call->as_CallLeaf()->_name != NULL &&
936 (strcmp(call->as_CallLeaf()->_name, "g1_wb_pre") == 0 ||
937 strcmp(call->as_CallLeaf()->_name, "g1_wb_post") == 0 ||
938 strcmp(call->as_CallLeaf()->_name, "updateBytesCRC32") == 0 ||
939 strcmp(call->as_CallLeaf()->_name, "aescrypt_encryptBlock") == 0 ||
940 strcmp(call->as_CallLeaf()->_name, "aescrypt_decryptBlock") == 0 ||
941 strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_encryptAESCrypt") == 0 ||
942 strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_decryptAESCrypt") == 0)
943 ))) {
944 call->dump();
945 fatal(err_msg_res("EA unexpected CallLeaf %s", call->as_CallLeaf()->_name));
946 }
947 #endif
948 // Always process arraycopy's destination object since
949 // we need to add all possible edges to references in
950 // source object.
951 if (arg_esc >= PointsToNode::ArgEscape &&
952 !arg_is_arraycopy_dest) {
953 continue;
954 }
955 set_escape_state(arg_ptn, PointsToNode::ArgEscape);
956 if (arg_is_arraycopy_dest) {
957 Node* src = call->in(TypeFunc::Parms);
958 if (src->is_AddP()) {
959 src = get_addp_base(src);
960 }
961 PointsToNode* src_ptn = ptnode_adr(src->_idx);
962 assert(src_ptn != NULL, "should be registered");
963 if (arg_ptn != src_ptn) {
964 // Special arraycopy edge:
965 // A destination object's field can't have the source object
966 // as base since objects escape states are not related.
967 // Only escape state of destination object's fields affects
968 // escape state of fields in source object.
969 add_arraycopy(call, PointsToNode::ArgEscape, src_ptn, arg_ptn);
970 }
971 }
972 }
973 }
974 break;
975 }
976 case Op_CallStaticJava: {
977 // For a static call, we know exactly what method is being called.
978 // Use bytecode estimator to record the call's escape affects
979 #ifdef ASSERT
980 const char* name = call->as_CallStaticJava()->_name;
981 assert((name == NULL || strcmp(name, "uncommon_trap") != 0), "normal calls only");
982 #endif
983 ciMethod* meth = call->as_CallJava()->method();
984 if ((meth != NULL) && meth->is_boxing_method()) {
985 break; // Boxing methods do not modify any oops.
986 }
987 BCEscapeAnalyzer* call_analyzer = (meth !=NULL) ? meth->get_bcea() : NULL;
988 // fall-through if not a Java method or no analyzer information
989 if (call_analyzer != NULL) {
990 PointsToNode* call_ptn = ptnode_adr(call->_idx);
991 const TypeTuple* d = call->tf()->domain();
992 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
993 const Type* at = d->field_at(i);
994 int k = i - TypeFunc::Parms;
995 Node* arg = call->in(i);
996 PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
997 if (at->isa_ptr() != NULL &&
998 call_analyzer->is_arg_returned(k)) {
999 // The call returns arguments.
1000 if (call_ptn != NULL) { // Is call's result used?
1001 assert(call_ptn->is_LocalVar(), "node should be registered");
1002 assert(arg_ptn != NULL, "node should be registered");
1003 add_edge(call_ptn, arg_ptn);
1004 }
1005 }
1006 if (at->isa_oopptr() != NULL &&
1007 arg_ptn->escape_state() < PointsToNode::GlobalEscape) {
1008 if (!call_analyzer->is_arg_stack(k)) {
1009 // The argument global escapes
1010 set_escape_state(arg_ptn, PointsToNode::GlobalEscape);
1011 } else {
1012 set_escape_state(arg_ptn, PointsToNode::ArgEscape);
1013 if (!call_analyzer->is_arg_local(k)) {
1014 // The argument itself doesn't escape, but any fields might
1015 set_fields_escape_state(arg_ptn, PointsToNode::GlobalEscape);
1016 }
1017 }
1018 }
1019 }
1020 if (call_ptn != NULL && call_ptn->is_LocalVar()) {
1021 // The call returns arguments.
1022 assert(call_ptn->edge_count() > 0, "sanity");
1023 if (!call_analyzer->is_return_local()) {
1024 // Returns also unknown object.
1025 add_edge(call_ptn, phantom_obj);
1026 }
1027 }
1028 break;
1029 }
1030 }
1031 default: {
1032 // Fall-through here if not a Java method or no analyzer information
1033 // or some other type of call, assume the worst case: all arguments
1034 // globally escape.
1035 const TypeTuple* d = call->tf()->domain();
1036 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1037 const Type* at = d->field_at(i);
1038 if (at->isa_oopptr() != NULL) {
1039 Node* arg = call->in(i);
1040 if (arg->is_AddP()) {
1041 arg = get_addp_base(arg);
1042 }
1043 assert(ptnode_adr(arg->_idx) != NULL, "should be defined already");
1044 set_escape_state(ptnode_adr(arg->_idx), PointsToNode::GlobalEscape);
1045 }
1046 }
1047 }
1048 }
1049 }
1050
1051
1052 // Finish Graph construction.
1053 bool ConnectionGraph::complete_connection_graph(
1054 GrowableArray<PointsToNode*>& ptnodes_worklist,
1055 GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1056 GrowableArray<JavaObjectNode*>& java_objects_worklist,
1057 GrowableArray<FieldNode*>& oop_fields_worklist) {
1058 // Normally only 1-3 passes needed to build Connection Graph depending
1059 // on graph complexity. Observed 8 passes in jvm2008 compiler.compiler.
1060 // Set limit to 20 to catch situation when something did go wrong and
1061 // bailout Escape Analysis.
1062 // Also limit build time to 30 sec (60 in debug VM).
1063 #define CG_BUILD_ITER_LIMIT 20
1064 #ifdef ASSERT
1065 #define CG_BUILD_TIME_LIMIT 60.0
1066 #else
1067 #define CG_BUILD_TIME_LIMIT 30.0
1068 #endif
1069
1070 // Propagate GlobalEscape and ArgEscape escape states and check that
1071 // we still have non-escaping objects. The method pushs on _worklist
1072 // Field nodes which reference phantom_object.
1073 if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1074 return false; // Nothing to do.
1075 }
1076 // Now propagate references to all JavaObject nodes.
1077 int java_objects_length = java_objects_worklist.length();
1078 elapsedTimer time;
1079 int new_edges = 1;
1080 int iterations = 0;
1081 do {
1082 while ((new_edges > 0) &&
1083 (iterations++ < CG_BUILD_ITER_LIMIT) &&
1084 (time.seconds() < CG_BUILD_TIME_LIMIT)) {
1085 time.start();
1086 new_edges = 0;
1087 // Propagate references to phantom_object for nodes pushed on _worklist
1088 // by find_non_escaped_objects() and find_field_value().
1089 new_edges += add_java_object_edges(phantom_obj, false);
1090 for (int next = 0; next < java_objects_length; ++next) {
1091 JavaObjectNode* ptn = java_objects_worklist.at(next);
1092 new_edges += add_java_object_edges(ptn, true);
1093 }
1094 if (new_edges > 0) {
1095 // Update escape states on each iteration if graph was updated.
1096 if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1097 return false; // Nothing to do.
1098 }
1099 }
1100 time.stop();
1101 }
1102 if ((iterations < CG_BUILD_ITER_LIMIT) &&
1103 (time.seconds() < CG_BUILD_TIME_LIMIT)) {
1104 time.start();
1105 // Find fields which have unknown value.
1106 int fields_length = oop_fields_worklist.length();
1107 for (int next = 0; next < fields_length; next++) {
1108 FieldNode* field = oop_fields_worklist.at(next);
1109 if (field->edge_count() == 0) {
1110 new_edges += find_field_value(field);
1111 // This code may added new edges to phantom_object.
1112 // Need an other cycle to propagate references to phantom_object.
1113 }
1114 }
1115 time.stop();
1116 } else {
1117 new_edges = 0; // Bailout
1118 }
1119 } while (new_edges > 0);
1120
1121 // Bailout if passed limits.
1122 if ((iterations >= CG_BUILD_ITER_LIMIT) ||
1123 (time.seconds() >= CG_BUILD_TIME_LIMIT)) {
1124 Compile* C = _compile;
1125 if (C->log() != NULL) {
1126 C->log()->begin_elem("connectionGraph_bailout reason='reached ");
1127 C->log()->text("%s", (iterations >= CG_BUILD_ITER_LIMIT) ? "iterations" : "time");
1128 C->log()->end_elem(" limit'");
1129 }
1130 assert(ExitEscapeAnalysisOnTimeout, err_msg_res("infinite EA connection graph build (%f sec, %d iterations) with %d nodes and worklist size %d",
1131 time.seconds(), iterations, nodes_size(), ptnodes_worklist.length()));
1132 // Possible infinite build_connection_graph loop,
1133 // bailout (no changes to ideal graph were made).
1134 return false;
1135 }
1136 #ifdef ASSERT
1137 if (Verbose && PrintEscapeAnalysis) {
1138 tty->print_cr("EA: %d iterations to build connection graph with %d nodes and worklist size %d",
1139 iterations, nodes_size(), ptnodes_worklist.length());
1140 }
1141 #endif
1142
1143 #undef CG_BUILD_ITER_LIMIT
1144 #undef CG_BUILD_TIME_LIMIT
1145
1146 // Find fields initialized by NULL for non-escaping Allocations.
1147 int non_escaped_length = non_escaped_worklist.length();
1148 for (int next = 0; next < non_escaped_length; next++) {
1149 JavaObjectNode* ptn = non_escaped_worklist.at(next);
1150 PointsToNode::EscapeState es = ptn->escape_state();
1151 assert(es <= PointsToNode::ArgEscape, "sanity");
1152 if (es == PointsToNode::NoEscape) {
1153 if (find_init_values(ptn, null_obj, _igvn) > 0) {
1154 // Adding references to NULL object does not change escape states
1155 // since it does not escape. Also no fields are added to NULL object.
1156 add_java_object_edges(null_obj, false);
1157 }
1158 }
1159 Node* n = ptn->ideal_node();
1160 if (n->is_Allocate()) {
1161 // The object allocated by this Allocate node will never be
1162 // seen by an other thread. Mark it so that when it is
1163 // expanded no MemBarStoreStore is added.
1164 InitializeNode* ini = n->as_Allocate()->initialization();
1165 if (ini != NULL)
1166 ini->set_does_not_escape();
1167 }
1168 }
1169 return true; // Finished graph construction.
1170 }
1171
1172 // Propagate GlobalEscape and ArgEscape escape states to all nodes
1173 // and check that we still have non-escaping java objects.
1174 bool ConnectionGraph::find_non_escaped_objects(GrowableArray<PointsToNode*>& ptnodes_worklist,
1175 GrowableArray<JavaObjectNode*>& non_escaped_worklist) {
1176 GrowableArray<PointsToNode*> escape_worklist;
1177 // First, put all nodes with GlobalEscape and ArgEscape states on worklist.
1178 int ptnodes_length = ptnodes_worklist.length();
1179 for (int next = 0; next < ptnodes_length; ++next) {
1180 PointsToNode* ptn = ptnodes_worklist.at(next);
1181 if (ptn->escape_state() >= PointsToNode::ArgEscape ||
1182 ptn->fields_escape_state() >= PointsToNode::ArgEscape) {
1183 escape_worklist.push(ptn);
1184 }
1185 }
1186 // Set escape states to referenced nodes (edges list).
1187 while (escape_worklist.length() > 0) {
1188 PointsToNode* ptn = escape_worklist.pop();
1189 PointsToNode::EscapeState es = ptn->escape_state();
1190 PointsToNode::EscapeState field_es = ptn->fields_escape_state();
1191 if (ptn->is_Field() && ptn->as_Field()->is_oop() &&
1192 es >= PointsToNode::ArgEscape) {
1193 // GlobalEscape or ArgEscape state of field means it has unknown value.
1194 if (add_edge(ptn, phantom_obj)) {
1195 // New edge was added
1196 add_field_uses_to_worklist(ptn->as_Field());
1197 }
1198 }
1199 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1200 PointsToNode* e = i.get();
1201 if (e->is_Arraycopy()) {
1202 assert(ptn->arraycopy_dst(), "sanity");
1203 // Propagate only fields escape state through arraycopy edge.
1204 if (e->fields_escape_state() < field_es) {
1205 set_fields_escape_state(e, field_es);
1206 escape_worklist.push(e);
1207 }
1208 } else if (es >= field_es) {
1209 // fields_escape_state is also set to 'es' if it is less than 'es'.
1210 if (e->escape_state() < es) {
1211 set_escape_state(e, es);
1212 escape_worklist.push(e);
1213 }
1214 } else {
1215 // Propagate field escape state.
1216 bool es_changed = false;
1217 if (e->fields_escape_state() < field_es) {
1218 set_fields_escape_state(e, field_es);
1219 es_changed = true;
1220 }
1221 if ((e->escape_state() < field_es) &&
1222 e->is_Field() && ptn->is_JavaObject() &&
1223 e->as_Field()->is_oop()) {
1224 // Change escape state of referenced fileds.
1225 set_escape_state(e, field_es);
1226 es_changed = true;;
1227 } else if (e->escape_state() < es) {
1228 set_escape_state(e, es);
1229 es_changed = true;;
1230 }
1231 if (es_changed) {
1232 escape_worklist.push(e);
1233 }
1234 }
1235 }
1236 }
1237 // Remove escaped objects from non_escaped list.
1238 for (int next = non_escaped_worklist.length()-1; next >= 0 ; --next) {
1239 JavaObjectNode* ptn = non_escaped_worklist.at(next);
1240 if (ptn->escape_state() >= PointsToNode::GlobalEscape) {
1241 non_escaped_worklist.delete_at(next);
1242 }
1243 if (ptn->escape_state() == PointsToNode::NoEscape) {
1244 // Find fields in non-escaped allocations which have unknown value.
1245 find_init_values(ptn, phantom_obj, NULL);
1246 }
1247 }
1248 return (non_escaped_worklist.length() > 0);
1249 }
1250
1251 // Add all references to JavaObject node by walking over all uses.
1252 int ConnectionGraph::add_java_object_edges(JavaObjectNode* jobj, bool populate_worklist) {
1253 int new_edges = 0;
1254 if (populate_worklist) {
1255 // Populate _worklist by uses of jobj's uses.
1256 for (UseIterator i(jobj); i.has_next(); i.next()) {
1257 PointsToNode* use = i.get();
1258 if (use->is_Arraycopy())
1259 continue;
1260 add_uses_to_worklist(use);
1261 if (use->is_Field() && use->as_Field()->is_oop()) {
1262 // Put on worklist all field's uses (loads) and
1263 // related field nodes (same base and offset).
1264 add_field_uses_to_worklist(use->as_Field());
1265 }
1266 }
1267 }
1268 while(_worklist.length() > 0) {
1269 PointsToNode* use = _worklist.pop();
1270 if (PointsToNode::is_base_use(use)) {
1271 // Add reference from jobj to field and from field to jobj (field's base).
1272 use = PointsToNode::get_use_node(use)->as_Field();
1273 if (add_base(use->as_Field(), jobj)) {
1274 new_edges++;
1275 }
1276 continue;
1277 }
1278 assert(!use->is_JavaObject(), "sanity");
1279 if (use->is_Arraycopy()) {
1280 if (jobj == null_obj) // NULL object does not have field edges
1281 continue;
1282 // Added edge from Arraycopy node to arraycopy's source java object
1283 if (add_edge(use, jobj)) {
1284 jobj->set_arraycopy_src();
1285 new_edges++;
1286 }
1287 // and stop here.
1288 continue;
1289 }
1290 if (!add_edge(use, jobj))
1291 continue; // No new edge added, there was such edge already.
1292 new_edges++;
1293 if (use->is_LocalVar()) {
1294 add_uses_to_worklist(use);
1295 if (use->arraycopy_dst()) {
1296 for (EdgeIterator i(use); i.has_next(); i.next()) {
1297 PointsToNode* e = i.get();
1298 if (e->is_Arraycopy()) {
1299 if (jobj == null_obj) // NULL object does not have field edges
1300 continue;
1301 // Add edge from arraycopy's destination java object to Arraycopy node.
1302 if (add_edge(jobj, e)) {
1303 new_edges++;
1304 jobj->set_arraycopy_dst();
1305 }
1306 }
1307 }
1308 }
1309 } else {
1310 // Added new edge to stored in field values.
1311 // Put on worklist all field's uses (loads) and
1312 // related field nodes (same base and offset).
1313 add_field_uses_to_worklist(use->as_Field());
1314 }
1315 }
1316 return new_edges;
1317 }
1318
1319 // Put on worklist all related field nodes.
1320 void ConnectionGraph::add_field_uses_to_worklist(FieldNode* field) {
1321 assert(field->is_oop(), "sanity");
1322 int offset = field->offset();
1323 add_uses_to_worklist(field);
1324 // Loop over all bases of this field and push on worklist Field nodes
1325 // with the same offset and base (since they may reference the same field).
1326 for (BaseIterator i(field); i.has_next(); i.next()) {
1327 PointsToNode* base = i.get();
1328 add_fields_to_worklist(field, base);
1329 // Check if the base was source object of arraycopy and go over arraycopy's
1330 // destination objects since values stored to a field of source object are
1331 // accessable by uses (loads) of fields of destination objects.
1332 if (base->arraycopy_src()) {
1333 for (UseIterator j(base); j.has_next(); j.next()) {
1334 PointsToNode* arycp = j.get();
1335 if (arycp->is_Arraycopy()) {
1336 for (UseIterator k(arycp); k.has_next(); k.next()) {
1337 PointsToNode* abase = k.get();
1338 if (abase->arraycopy_dst() && abase != base) {
1339 // Look for the same arracopy reference.
1340 add_fields_to_worklist(field, abase);
1341 }
1342 }
1343 }
1344 }
1345 }
1346 }
1347 }
1348
1349 // Put on worklist all related field nodes.
1350 void ConnectionGraph::add_fields_to_worklist(FieldNode* field, PointsToNode* base) {
1351 int offset = field->offset();
1352 if (base->is_LocalVar()) {
1353 for (UseIterator j(base); j.has_next(); j.next()) {
1354 PointsToNode* f = j.get();
1355 if (PointsToNode::is_base_use(f)) { // Field
1356 f = PointsToNode::get_use_node(f);
1357 if (f == field || !f->as_Field()->is_oop())
1358 continue;
1359 int offs = f->as_Field()->offset();
1360 if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1361 add_to_worklist(f);
1362 }
1363 }
1364 }
1365 } else {
1366 assert(base->is_JavaObject(), "sanity");
1367 if (// Skip phantom_object since it is only used to indicate that
1368 // this field's content globally escapes.
1369 (base != phantom_obj) &&
1370 // NULL object node does not have fields.
1371 (base != null_obj)) {
1372 for (EdgeIterator i(base); i.has_next(); i.next()) {
1373 PointsToNode* f = i.get();
1374 // Skip arraycopy edge since store to destination object field
1375 // does not update value in source object field.
1376 if (f->is_Arraycopy()) {
1377 assert(base->arraycopy_dst(), "sanity");
1378 continue;
1379 }
1380 if (f == field || !f->as_Field()->is_oop())
1381 continue;
1382 int offs = f->as_Field()->offset();
1383 if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1384 add_to_worklist(f);
1385 }
1386 }
1387 }
1388 }
1389 }
1390
1391 // Find fields which have unknown value.
1392 int ConnectionGraph::find_field_value(FieldNode* field) {
1393 // Escaped fields should have init value already.
1394 assert(field->escape_state() == PointsToNode::NoEscape, "sanity");
1395 int new_edges = 0;
1396 for (BaseIterator i(field); i.has_next(); i.next()) {
1397 PointsToNode* base = i.get();
1398 if (base->is_JavaObject()) {
1399 // Skip Allocate's fields which will be processed later.
1400 if (base->ideal_node()->is_Allocate())
1401 return 0;
1402 assert(base == null_obj, "only NULL ptr base expected here");
1403 }
1404 }
1405 if (add_edge(field, phantom_obj)) {
1406 // New edge was added
1407 new_edges++;
1408 add_field_uses_to_worklist(field);
1409 }
1410 return new_edges;
1411 }
1412
1413 // Find fields initializing values for allocations.
1414 int ConnectionGraph::find_init_values(JavaObjectNode* pta, PointsToNode* init_val, PhaseTransform* phase) {
1415 assert(pta->escape_state() == PointsToNode::NoEscape, "Not escaped Allocate nodes only");
1416 int new_edges = 0;
1417 Node* alloc = pta->ideal_node();
1418 if (init_val == phantom_obj) {
1419 // Do nothing for Allocate nodes since its fields values are "known".
1420 if (alloc->is_Allocate())
1421 return 0;
1422 assert(alloc->as_CallStaticJava(), "sanity");
1423 #ifdef ASSERT
1424 if (alloc->as_CallStaticJava()->method() == NULL) {
1425 const char* name = alloc->as_CallStaticJava()->_name;
1426 assert(strncmp(name, "_multianewarray", 15) == 0, "sanity");
1427 }
1428 #endif
1429 // Non-escaped allocation returned from Java or runtime call have
1430 // unknown values in fields.
1431 for (EdgeIterator i(pta); i.has_next(); i.next()) {
1432 PointsToNode* field = i.get();
1433 if (field->is_Field() && field->as_Field()->is_oop()) {
1434 if (add_edge(field, phantom_obj)) {
1435 // New edge was added
1436 new_edges++;
1437 add_field_uses_to_worklist(field->as_Field());
1438 }
1439 }
1440 }
1441 return new_edges;
1442 }
1443 assert(init_val == null_obj, "sanity");
1444 // Do nothing for Call nodes since its fields values are unknown.
1445 if (!alloc->is_Allocate())
1446 return 0;
1447
1448 InitializeNode* ini = alloc->as_Allocate()->initialization();
1449 Compile* C = _compile;
1450 bool visited_bottom_offset = false;
1451 GrowableArray<int> offsets_worklist;
1452
1453 // Check if an oop field's initializing value is recorded and add
1454 // a corresponding NULL if field's value if it is not recorded.
1455 // Connection Graph does not record a default initialization by NULL
1456 // captured by Initialize node.
1457 //
1458 for (EdgeIterator i(pta); i.has_next(); i.next()) {
1459 PointsToNode* field = i.get(); // Field (AddP)
1460 if (!field->is_Field() || !field->as_Field()->is_oop())
1461 continue; // Not oop field
1462 int offset = field->as_Field()->offset();
1463 if (offset == Type::OffsetBot) {
1464 if (!visited_bottom_offset) {
1465 // OffsetBot is used to reference array's element,
1466 // always add reference to NULL to all Field nodes since we don't
1467 // known which element is referenced.
1468 if (add_edge(field, null_obj)) {
1469 // New edge was added
1470 new_edges++;
1471 add_field_uses_to_worklist(field->as_Field());
1472 visited_bottom_offset = true;
1473 }
1474 }
1475 } else {
1476 // Check only oop fields.
1477 const Type* adr_type = field->ideal_node()->as_AddP()->bottom_type();
1478 if (adr_type->isa_rawptr()) {
1479 #ifdef ASSERT
1480 // Raw pointers are used for initializing stores so skip it
1481 // since it should be recorded already
1482 Node* base = get_addp_base(field->ideal_node());
1483 assert(adr_type->isa_rawptr() && base->is_Proj() &&
1484 (base->in(0) == alloc),"unexpected pointer type");
1485 #endif
1486 continue;
1487 }
1488 if (!offsets_worklist.contains(offset)) {
1489 offsets_worklist.append(offset);
1490 Node* value = NULL;
1491 if (ini != NULL) {
1492 // StoreP::memory_type() == T_ADDRESS
1493 BasicType ft = UseCompressedOops ? T_NARROWOOP : T_ADDRESS;
1494 Node* store = ini->find_captured_store(offset, type2aelembytes(ft, true), phase);
1495 // Make sure initializing store has the same type as this AddP.
1496 // This AddP may reference non existing field because it is on a
1497 // dead branch of bimorphic call which is not eliminated yet.
1498 if (store != NULL && store->is_Store() &&
1499 store->as_Store()->memory_type() == ft) {
1500 value = store->in(MemNode::ValueIn);
1501 #ifdef ASSERT
1502 if (VerifyConnectionGraph) {
1503 // Verify that AddP already points to all objects the value points to.
1504 PointsToNode* val = ptnode_adr(value->_idx);
1505 assert((val != NULL), "should be processed already");
1506 PointsToNode* missed_obj = NULL;
1507 if (val->is_JavaObject()) {
1508 if (!field->points_to(val->as_JavaObject())) {
1509 missed_obj = val;
1510 }
1511 } else {
1512 if (!val->is_LocalVar() || (val->edge_count() == 0)) {
1513 tty->print_cr("----------init store has invalid value -----");
1514 store->dump();
1515 val->dump();
1516 assert(val->is_LocalVar() && (val->edge_count() > 0), "should be processed already");
1517 }
1518 for (EdgeIterator j(val); j.has_next(); j.next()) {
1519 PointsToNode* obj = j.get();
1520 if (obj->is_JavaObject()) {
1521 if (!field->points_to(obj->as_JavaObject())) {
1522 missed_obj = obj;
1523 break;
1524 }
1525 }
1526 }
1527 }
1528 if (missed_obj != NULL) {
1529 tty->print_cr("----------field---------------------------------");
1530 field->dump();
1531 tty->print_cr("----------missed referernce to object-----------");
1532 missed_obj->dump();
1533 tty->print_cr("----------object referernced by init store -----");
1534 store->dump();
1535 val->dump();
1536 assert(!field->points_to(missed_obj->as_JavaObject()), "missed JavaObject reference");
1537 }
1538 }
1539 #endif
1540 } else {
1541 // There could be initializing stores which follow allocation.
1542 // For example, a volatile field store is not collected
1543 // by Initialize node.
1544 //
1545 // Need to check for dependent loads to separate such stores from
1546 // stores which follow loads. For now, add initial value NULL so
1547 // that compare pointers optimization works correctly.
1548 }
1549 }
1550 if (value == NULL) {
1551 // A field's initializing value was not recorded. Add NULL.
1552 if (add_edge(field, null_obj)) {
1553 // New edge was added
1554 new_edges++;
1555 add_field_uses_to_worklist(field->as_Field());
1556 }
1557 }
1558 }
1559 }
1560 }
1561 return new_edges;
1562 }
1563
1564 // Adjust scalar_replaceable state after Connection Graph is built.
1565 void ConnectionGraph::adjust_scalar_replaceable_state(JavaObjectNode* jobj) {
1566 // Search for non-escaping objects which are not scalar replaceable
1567 // and mark them to propagate the state to referenced objects.
1568
1569 // 1. An object is not scalar replaceable if the field into which it is
1570 // stored has unknown offset (stored into unknown element of an array).
1571 //
1572 for (UseIterator i(jobj); i.has_next(); i.next()) {
1573 PointsToNode* use = i.get();
1574 assert(!use->is_Arraycopy(), "sanity");
1575 if (use->is_Field()) {
1576 FieldNode* field = use->as_Field();
1577 assert(field->is_oop() && field->scalar_replaceable() &&
1578 field->fields_escape_state() == PointsToNode::NoEscape, "sanity");
1579 if (field->offset() == Type::OffsetBot) {
1580 jobj->set_scalar_replaceable(false);
1581 return;
1582 }
1583 // 2. An object is not scalar replaceable if the field into which it is
1584 // stored has multiple bases one of which is null.
1585 if (field->base_count() > 1) {
1586 for (BaseIterator i(field); i.has_next(); i.next()) {
1587 PointsToNode* base = i.get();
1588 if (base == null_obj) {
1589 jobj->set_scalar_replaceable(false);
1590 return;
1591 }
1592 }
1593 }
1594 }
1595 assert(use->is_Field() || use->is_LocalVar(), "sanity");
1596 // 3. An object is not scalar replaceable if it is merged with other objects.
1597 for (EdgeIterator j(use); j.has_next(); j.next()) {
1598 PointsToNode* ptn = j.get();
1599 if (ptn->is_JavaObject() && ptn != jobj) {
1600 // Mark all objects.
1601 jobj->set_scalar_replaceable(false);
1602 ptn->set_scalar_replaceable(false);
1603 }
1604 }
1605 if (!jobj->scalar_replaceable()) {
1606 return;
1607 }
1608 }
1609
1610 for (EdgeIterator j(jobj); j.has_next(); j.next()) {
1611 // Non-escaping object node should point only to field nodes.
1612 FieldNode* field = j.get()->as_Field();
1613 int offset = field->as_Field()->offset();
1614
1615 // 4. An object is not scalar replaceable if it has a field with unknown
1616 // offset (array's element is accessed in loop).
1617 if (offset == Type::OffsetBot) {
1618 jobj->set_scalar_replaceable(false);
1619 return;
1620 }
1621 // 5. Currently an object is not scalar replaceable if a LoadStore node
1622 // access its field since the field value is unknown after it.
1623 //
1624 Node* n = field->ideal_node();
1625 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1626 if (n->fast_out(i)->is_LoadStore()) {
1627 jobj->set_scalar_replaceable(false);
1628 return;
1629 }
1630 }
1631
1632 // 6. Or the address may point to more then one object. This may produce
1633 // the false positive result (set not scalar replaceable)
1634 // since the flow-insensitive escape analysis can't separate
1635 // the case when stores overwrite the field's value from the case
1636 // when stores happened on different control branches.
1637 //
1638 // Note: it will disable scalar replacement in some cases:
1639 //
1640 // Point p[] = new Point[1];
1641 // p[0] = new Point(); // Will be not scalar replaced
1642 //
1643 // but it will save us from incorrect optimizations in next cases:
1644 //
1645 // Point p[] = new Point[1];
1646 // if ( x ) p[0] = new Point(); // Will be not scalar replaced
1647 //
1648 if (field->base_count() > 1) {
1649 for (BaseIterator i(field); i.has_next(); i.next()) {
1650 PointsToNode* base = i.get();
1651 // Don't take into account LocalVar nodes which
1652 // may point to only one object which should be also
1653 // this field's base by now.
1654 if (base->is_JavaObject() && base != jobj) {
1655 // Mark all bases.
1656 jobj->set_scalar_replaceable(false);
1657 base->set_scalar_replaceable(false);
1658 }
1659 }
1660 }
1661 }
1662 }
1663
1664 #ifdef ASSERT
1665 void ConnectionGraph::verify_connection_graph(
1666 GrowableArray<PointsToNode*>& ptnodes_worklist,
1667 GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1668 GrowableArray<JavaObjectNode*>& java_objects_worklist,
1669 GrowableArray<Node*>& addp_worklist) {
1670 // Verify that graph is complete - no new edges could be added.
1671 int java_objects_length = java_objects_worklist.length();
1672 int non_escaped_length = non_escaped_worklist.length();
1673 int new_edges = 0;
1674 for (int next = 0; next < java_objects_length; ++next) {
1675 JavaObjectNode* ptn = java_objects_worklist.at(next);
1676 new_edges += add_java_object_edges(ptn, true);
1677 }
1678 assert(new_edges == 0, "graph was not complete");
1679 // Verify that escape state is final.
1680 int length = non_escaped_worklist.length();
1681 find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist);
1682 assert((non_escaped_length == non_escaped_worklist.length()) &&
1683 (non_escaped_length == length) &&
1684 (_worklist.length() == 0), "escape state was not final");
1685
1686 // Verify fields information.
1687 int addp_length = addp_worklist.length();
1688 for (int next = 0; next < addp_length; ++next ) {
1689 Node* n = addp_worklist.at(next);
1690 FieldNode* field = ptnode_adr(n->_idx)->as_Field();
1691 if (field->is_oop()) {
1692 // Verify that field has all bases
1693 Node* base = get_addp_base(n);
1694 PointsToNode* ptn = ptnode_adr(base->_idx);
1695 if (ptn->is_JavaObject()) {
1696 assert(field->has_base(ptn->as_JavaObject()), "sanity");
1697 } else {
1698 assert(ptn->is_LocalVar(), "sanity");
1699 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1700 PointsToNode* e = i.get();
1701 if (e->is_JavaObject()) {
1702 assert(field->has_base(e->as_JavaObject()), "sanity");
1703 }
1704 }
1705 }
1706 // Verify that all fields have initializing values.
1707 if (field->edge_count() == 0) {
1708 tty->print_cr("----------field does not have references----------");
1709 field->dump();
1710 for (BaseIterator i(field); i.has_next(); i.next()) {
1711 PointsToNode* base = i.get();
1712 tty->print_cr("----------field has next base---------------------");
1713 base->dump();
1714 if (base->is_JavaObject() && (base != phantom_obj) && (base != null_obj)) {
1715 tty->print_cr("----------base has fields-------------------------");
1716 for (EdgeIterator j(base); j.has_next(); j.next()) {
1717 j.get()->dump();
1718 }
1719 tty->print_cr("----------base has references---------------------");
1720 for (UseIterator j(base); j.has_next(); j.next()) {
1721 j.get()->dump();
1722 }
1723 }
1724 }
1725 for (UseIterator i(field); i.has_next(); i.next()) {
1726 i.get()->dump();
1727 }
1728 assert(field->edge_count() > 0, "sanity");
1729 }
1730 }
1731 }
1732 }
1733 #endif
1734
1735 // Optimize ideal graph.
1736 void ConnectionGraph::optimize_ideal_graph(GrowableArray<Node*>& ptr_cmp_worklist,
1737 GrowableArray<Node*>& storestore_worklist) {
1738 Compile* C = _compile;
1739 PhaseIterGVN* igvn = _igvn;
1740 if (EliminateLocks) {
1741 // Mark locks before changing ideal graph.
1742 int cnt = C->macro_count();
1743 for( int i=0; i < cnt; i++ ) {
1744 Node *n = C->macro_node(i);
1745 if (n->is_AbstractLock()) { // Lock and Unlock nodes
1746 AbstractLockNode* alock = n->as_AbstractLock();
1747 if (!alock->is_non_esc_obj()) {
1748 if (not_global_escape(alock->obj_node())) {
1749 assert(!alock->is_eliminated() || alock->is_coarsened(), "sanity");
1750 // The lock could be marked eliminated by lock coarsening
1751 // code during first IGVN before EA. Replace coarsened flag
1752 // to eliminate all associated locks/unlocks.
1753 alock->set_non_esc_obj();
1754 }
1755 }
1756 }
1757 }
1758 }
1759
1760 if (OptimizePtrCompare) {
1761 // Add ConI(#CC_GT) and ConI(#CC_EQ).
1762 _pcmp_neq = igvn->makecon(TypeInt::CC_GT);
1763 _pcmp_eq = igvn->makecon(TypeInt::CC_EQ);
1764 // Optimize objects compare.
1765 while (ptr_cmp_worklist.length() != 0) {
1766 Node *n = ptr_cmp_worklist.pop();
1767 Node *res = optimize_ptr_compare(n);
1768 if (res != NULL) {
1769 #ifndef PRODUCT
1770 if (PrintOptimizePtrCompare) {
1771 tty->print_cr("++++ Replaced: %d %s(%d,%d) --> %s", n->_idx, (n->Opcode() == Op_CmpP ? "CmpP" : "CmpN"), n->in(1)->_idx, n->in(2)->_idx, (res == _pcmp_eq ? "EQ" : "NotEQ"));
1772 if (Verbose) {
1773 n->dump(1);
1774 }
1775 }
1776 #endif
1777 igvn->replace_node(n, res);
1778 }
1779 }
1780 // cleanup
1781 if (_pcmp_neq->outcnt() == 0)
1782 igvn->hash_delete(_pcmp_neq);
1783 if (_pcmp_eq->outcnt() == 0)
1784 igvn->hash_delete(_pcmp_eq);
1785 }
1786
1787 // For MemBarStoreStore nodes added in library_call.cpp, check
1788 // escape status of associated AllocateNode and optimize out
1789 // MemBarStoreStore node if the allocated object never escapes.
1790 while (storestore_worklist.length() != 0) {
1791 Node *n = storestore_worklist.pop();
1792 MemBarStoreStoreNode *storestore = n ->as_MemBarStoreStore();
1793 Node *alloc = storestore->in(MemBarNode::Precedent)->in(0);
1794 assert (alloc->is_Allocate(), "storestore should point to AllocateNode");
1795 if (not_global_escape(alloc)) {
1796 MemBarNode* mb = MemBarNode::make(C, Op_MemBarCPUOrder, Compile::AliasIdxBot);
1797 mb->init_req(TypeFunc::Memory, storestore->in(TypeFunc::Memory));
1798 mb->init_req(TypeFunc::Control, storestore->in(TypeFunc::Control));
1799 igvn->register_new_node_with_optimizer(mb);
1800 igvn->replace_node(storestore, mb);
1801 }
1802 }
1803 }
1804
1805 // Optimize objects compare.
1806 Node* ConnectionGraph::optimize_ptr_compare(Node* n) {
1807 assert(OptimizePtrCompare, "sanity");
1808 PointsToNode* ptn1 = ptnode_adr(n->in(1)->_idx);
1809 PointsToNode* ptn2 = ptnode_adr(n->in(2)->_idx);
1810 JavaObjectNode* jobj1 = unique_java_object(n->in(1));
1811 JavaObjectNode* jobj2 = unique_java_object(n->in(2));
1812 assert(ptn1->is_JavaObject() || ptn1->is_LocalVar(), "sanity");
1813 assert(ptn2->is_JavaObject() || ptn2->is_LocalVar(), "sanity");
1814
1815 // Check simple cases first.
1816 if (jobj1 != NULL) {
1817 if (jobj1->escape_state() == PointsToNode::NoEscape) {
1818 if (jobj1 == jobj2) {
1819 // Comparing the same not escaping object.
1820 return _pcmp_eq;
1821 }
1822 Node* obj = jobj1->ideal_node();
1823 // Comparing not escaping allocation.
1824 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1825 !ptn2->points_to(jobj1)) {
1826 return _pcmp_neq; // This includes nullness check.
1827 }
1828 }
1829 }
1830 if (jobj2 != NULL) {
1831 if (jobj2->escape_state() == PointsToNode::NoEscape) {
1832 Node* obj = jobj2->ideal_node();
1833 // Comparing not escaping allocation.
1834 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1835 !ptn1->points_to(jobj2)) {
1836 return _pcmp_neq; // This includes nullness check.
1837 }
1838 }
1839 }
1840 if (jobj1 != NULL && jobj1 != phantom_obj &&
1841 jobj2 != NULL && jobj2 != phantom_obj &&
1842 jobj1->ideal_node()->is_Con() &&
1843 jobj2->ideal_node()->is_Con()) {
1844 // Klass or String constants compare. Need to be careful with
1845 // compressed pointers - compare types of ConN and ConP instead of nodes.
1846 const Type* t1 = jobj1->ideal_node()->get_ptr_type();
1847 const Type* t2 = jobj2->ideal_node()->get_ptr_type();
1848 if (t1->make_ptr() == t2->make_ptr()) {
1849 return _pcmp_eq;
1850 } else {
1851 return _pcmp_neq;
1852 }
1853 }
1854 if (ptn1->meet(ptn2)) {
1855 return NULL; // Sets are not disjoint
1856 }
1857
1858 // Sets are disjoint.
1859 bool set1_has_unknown_ptr = ptn1->points_to(phantom_obj);
1860 bool set2_has_unknown_ptr = ptn2->points_to(phantom_obj);
1861 bool set1_has_null_ptr = ptn1->points_to(null_obj);
1862 bool set2_has_null_ptr = ptn2->points_to(null_obj);
1863 if (set1_has_unknown_ptr && set2_has_null_ptr ||
1864 set2_has_unknown_ptr && set1_has_null_ptr) {
1865 // Check nullness of unknown object.
1866 return NULL;
1867 }
1868
1869 // Disjointness by itself is not sufficient since
1870 // alias analysis is not complete for escaped objects.
1871 // Disjoint sets are definitely unrelated only when
1872 // at least one set has only not escaping allocations.
1873 if (!set1_has_unknown_ptr && !set1_has_null_ptr) {
1874 if (ptn1->non_escaping_allocation()) {
1875 return _pcmp_neq;
1876 }
1877 }
1878 if (!set2_has_unknown_ptr && !set2_has_null_ptr) {
1879 if (ptn2->non_escaping_allocation()) {
1880 return _pcmp_neq;
1881 }
1882 }
1883 return NULL;
1884 }
1885
1886 // Connection Graph constuction functions.
1887
1888 void ConnectionGraph::add_local_var(Node *n, PointsToNode::EscapeState es) {
1889 PointsToNode* ptadr = _nodes.at(n->_idx);
1890 if (ptadr != NULL) {
1891 assert(ptadr->is_LocalVar() && ptadr->ideal_node() == n, "sanity");
1892 return;
1893 }
1894 Compile* C = _compile;
1895 ptadr = new (C->comp_arena()) LocalVarNode(C, n, es);
1896 _nodes.at_put(n->_idx, ptadr);
1897 }
1898
1899 void ConnectionGraph::add_java_object(Node *n, PointsToNode::EscapeState es) {
1900 PointsToNode* ptadr = _nodes.at(n->_idx);
1901 if (ptadr != NULL) {
1902 assert(ptadr->is_JavaObject() && ptadr->ideal_node() == n, "sanity");
1903 return;
1904 }
1905 Compile* C = _compile;
1906 ptadr = new (C->comp_arena()) JavaObjectNode(C, n, es);
1907 _nodes.at_put(n->_idx, ptadr);
1908 }
1909
1910 void ConnectionGraph::add_field(Node *n, PointsToNode::EscapeState es, int offset) {
1911 PointsToNode* ptadr = _nodes.at(n->_idx);
1912 if (ptadr != NULL) {
1913 assert(ptadr->is_Field() && ptadr->ideal_node() == n, "sanity");
1914 return;
1915 }
1916 bool unsafe = false;
1917 bool is_oop = is_oop_field(n, offset, &unsafe);
1918 if (unsafe) {
1919 es = PointsToNode::GlobalEscape;
1920 }
1921 Compile* C = _compile;
1922 FieldNode* field = new (C->comp_arena()) FieldNode(C, n, es, offset, is_oop);
1923 _nodes.at_put(n->_idx, field);
1924 }
1925
1926 void ConnectionGraph::add_arraycopy(Node *n, PointsToNode::EscapeState es,
1927 PointsToNode* src, PointsToNode* dst) {
1928 assert(!src->is_Field() && !dst->is_Field(), "only for JavaObject and LocalVar");
1929 assert((src != null_obj) && (dst != null_obj), "not for ConP NULL");
1930 PointsToNode* ptadr = _nodes.at(n->_idx);
1931 if (ptadr != NULL) {
1932 assert(ptadr->is_Arraycopy() && ptadr->ideal_node() == n, "sanity");
1933 return;
1934 }
1935 Compile* C = _compile;
1936 ptadr = new (C->comp_arena()) ArraycopyNode(C, n, es);
1937 _nodes.at_put(n->_idx, ptadr);
1938 // Add edge from arraycopy node to source object.
1939 (void)add_edge(ptadr, src);
1940 src->set_arraycopy_src();
1941 // Add edge from destination object to arraycopy node.
1942 (void)add_edge(dst, ptadr);
1943 dst->set_arraycopy_dst();
1944 }
1945
1946 bool ConnectionGraph::is_oop_field(Node* n, int offset, bool* unsafe) {
1947 const Type* adr_type = n->as_AddP()->bottom_type();
1948 BasicType bt = T_INT;
1949 if (offset == Type::OffsetBot) {
1950 // Check only oop fields.
1951 if (!adr_type->isa_aryptr() ||
1952 (adr_type->isa_aryptr()->klass() == NULL) ||
1953 adr_type->isa_aryptr()->klass()->is_obj_array_klass()) {
1954 // OffsetBot is used to reference array's element. Ignore first AddP.
1955 if (find_second_addp(n, n->in(AddPNode::Base)) == NULL) {
1956 bt = T_OBJECT;
1957 }
1958 }
1959 } else if (offset != oopDesc::klass_offset_in_bytes()) {
1960 if (adr_type->isa_instptr()) {
1961 ciField* field = _compile->alias_type(adr_type->isa_instptr())->field();
1962 if (field != NULL) {
1963 bt = field->layout_type();
1964 } else {
1965 // Check for unsafe oop field access
1966 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1967 int opcode = n->fast_out(i)->Opcode();
1968 if (opcode == Op_StoreP || opcode == Op_LoadP ||
1969 opcode == Op_StoreN || opcode == Op_LoadN) {
1970 bt = T_OBJECT;
1971 (*unsafe) = true;
1972 break;
1973 }
1974 }
1975 }
1976 } else if (adr_type->isa_aryptr()) {
1977 if (offset == arrayOopDesc::length_offset_in_bytes()) {
1978 // Ignore array length load.
1979 } else if (find_second_addp(n, n->in(AddPNode::Base)) != NULL) {
1980 // Ignore first AddP.
1981 } else {
1982 const Type* elemtype = adr_type->isa_aryptr()->elem();
1983 bt = elemtype->array_element_basic_type();
1984 }
1985 } else if (adr_type->isa_rawptr() || adr_type->isa_klassptr()) {
1986 // Allocation initialization, ThreadLocal field access, unsafe access
1987 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1988 int opcode = n->fast_out(i)->Opcode();
1989 if (opcode == Op_StoreP || opcode == Op_LoadP ||
1990 opcode == Op_StoreN || opcode == Op_LoadN) {
1991 bt = T_OBJECT;
1992 break;
1993 }
1994 }
1995 }
1996 }
1997 return (bt == T_OBJECT || bt == T_NARROWOOP || bt == T_ARRAY);
1998 }
1999
2000 // Returns unique pointed java object or NULL.
2001 JavaObjectNode* ConnectionGraph::unique_java_object(Node *n) {
2002 assert(!_collecting, "should not call when contructed graph");
2003 // If the node was created after the escape computation we can't answer.
2004 uint idx = n->_idx;
2005 if (idx >= nodes_size()) {
2006 return NULL;
2007 }
2008 PointsToNode* ptn = ptnode_adr(idx);
2009 if (ptn->is_JavaObject()) {
2010 return ptn->as_JavaObject();
2011 }
2012 assert(ptn->is_LocalVar(), "sanity");
2013 // Check all java objects it points to.
2014 JavaObjectNode* jobj = NULL;
2015 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2016 PointsToNode* e = i.get();
2017 if (e->is_JavaObject()) {
2018 if (jobj == NULL) {
2019 jobj = e->as_JavaObject();
2020 } else if (jobj != e) {
2021 return NULL;
2022 }
2023 }
2024 }
2025 return jobj;
2026 }
2027
2028 // Return true if this node points only to non-escaping allocations.
2029 bool PointsToNode::non_escaping_allocation() {
2030 if (is_JavaObject()) {
2031 Node* n = ideal_node();
2032 if (n->is_Allocate() || n->is_CallStaticJava()) {
2033 return (escape_state() == PointsToNode::NoEscape);
2034 } else {
2035 return false;
2036 }
2037 }
2038 assert(is_LocalVar(), "sanity");
2039 // Check all java objects it points to.
2040 for (EdgeIterator i(this); i.has_next(); i.next()) {
2041 PointsToNode* e = i.get();
2042 if (e->is_JavaObject()) {
2043 Node* n = e->ideal_node();
2044 if ((e->escape_state() != PointsToNode::NoEscape) ||
2045 !(n->is_Allocate() || n->is_CallStaticJava())) {
2046 return false;
2047 }
2048 }
2049 }
2050 return true;
2051 }
2052
2053 // Return true if we know the node does not escape globally.
2054 bool ConnectionGraph::not_global_escape(Node *n) {
2055 assert(!_collecting, "should not call during graph construction");
2056 // If the node was created after the escape computation we can't answer.
2057 uint idx = n->_idx;
2058 if (idx >= nodes_size()) {
2059 return false;
2060 }
2061 PointsToNode* ptn = ptnode_adr(idx);
2062 PointsToNode::EscapeState es = ptn->escape_state();
2063 // If we have already computed a value, return it.
2064 if (es >= PointsToNode::GlobalEscape)
2065 return false;
2066 if (ptn->is_JavaObject()) {
2067 return true; // (es < PointsToNode::GlobalEscape);
2068 }
2069 assert(ptn->is_LocalVar(), "sanity");
2070 // Check all java objects it points to.
2071 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2072 if (i.get()->escape_state() >= PointsToNode::GlobalEscape)
2073 return false;
2074 }
2075 return true;
2076 }
2077
2078
2079 // Helper functions
2080
2081 // Return true if this node points to specified node or nodes it points to.
2082 bool PointsToNode::points_to(JavaObjectNode* ptn) const {
2083 if (is_JavaObject()) {
2084 return (this == ptn);
2085 }
2086 assert(is_LocalVar() || is_Field(), "sanity");
2087 for (EdgeIterator i(this); i.has_next(); i.next()) {
2088 if (i.get() == ptn)
2089 return true;
2090 }
2091 return false;
2092 }
2093
2094 // Return true if one node points to an other.
2095 bool PointsToNode::meet(PointsToNode* ptn) {
2096 if (this == ptn) {
2097 return true;
2098 } else if (ptn->is_JavaObject()) {
2099 return this->points_to(ptn->as_JavaObject());
2100 } else if (this->is_JavaObject()) {
2101 return ptn->points_to(this->as_JavaObject());
2102 }
2103 assert(this->is_LocalVar() && ptn->is_LocalVar(), "sanity");
2104 int ptn_count = ptn->edge_count();
2105 for (EdgeIterator i(this); i.has_next(); i.next()) {
2106 PointsToNode* this_e = i.get();
2107 for (int j = 0; j < ptn_count; j++) {
2108 if (this_e == ptn->edge(j))
2109 return true;
2110 }
2111 }
2112 return false;
2113 }
2114
2115 #ifdef ASSERT
2116 // Return true if bases point to this java object.
2117 bool FieldNode::has_base(JavaObjectNode* jobj) const {
2118 for (BaseIterator i(this); i.has_next(); i.next()) {
2119 if (i.get() == jobj)
2120 return true;
2121 }
2122 return false;
2123 }
2124 #endif
2125
2126 int ConnectionGraph::address_offset(Node* adr, PhaseTransform *phase) {
2127 const Type *adr_type = phase->type(adr);
2128 if (adr->is_AddP() && adr_type->isa_oopptr() == NULL &&
2129 adr->in(AddPNode::Address)->is_Proj() &&
2130 adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
2131 // We are computing a raw address for a store captured by an Initialize
2132 // compute an appropriate address type. AddP cases #3 and #5 (see below).
2133 int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
2134 assert(offs != Type::OffsetBot ||
2135 adr->in(AddPNode::Address)->in(0)->is_AllocateArray(),
2136 "offset must be a constant or it is initialization of array");
2137 return offs;
2138 }
2139 const TypePtr *t_ptr = adr_type->isa_ptr();
2140 assert(t_ptr != NULL, "must be a pointer type");
2141 return t_ptr->offset();
2142 }
2143
2144 Node* ConnectionGraph::get_addp_base(Node *addp) {
2145 assert(addp->is_AddP(), "must be AddP");
2146 //
2147 // AddP cases for Base and Address inputs:
2148 // case #1. Direct object's field reference:
2149 // Allocate
2150 // |
2151 // Proj #5 ( oop result )
2152 // |
2153 // CheckCastPP (cast to instance type)
2154 // | |
2155 // AddP ( base == address )
2156 //
2157 // case #2. Indirect object's field reference:
2158 // Phi
2159 // |
2160 // CastPP (cast to instance type)
2161 // | |
2162 // AddP ( base == address )
2163 //
2164 // case #3. Raw object's field reference for Initialize node:
2165 // Allocate
2166 // |
2167 // Proj #5 ( oop result )
2168 // top |
2169 // \ |
2170 // AddP ( base == top )
2171 //
2172 // case #4. Array's element reference:
2173 // {CheckCastPP | CastPP}
2174 // | | |
2175 // | AddP ( array's element offset )
2176 // | |
2177 // AddP ( array's offset )
2178 //
2179 // case #5. Raw object's field reference for arraycopy stub call:
2180 // The inline_native_clone() case when the arraycopy stub is called
2181 // after the allocation before Initialize and CheckCastPP nodes.
2182 // Allocate
2183 // |
2184 // Proj #5 ( oop result )
2185 // | |
2186 // AddP ( base == address )
2187 //
2188 // case #6. Constant Pool, ThreadLocal, CastX2P or
2189 // Raw object's field reference:
2190 // {ConP, ThreadLocal, CastX2P, raw Load}
2191 // top |
2192 // \ |
2193 // AddP ( base == top )
2194 //
2195 // case #7. Klass's field reference.
2196 // LoadKlass
2197 // | |
2198 // AddP ( base == address )
2199 //
2200 // case #8. narrow Klass's field reference.
2201 // LoadNKlass
2202 // |
2203 // DecodeN
2204 // | |
2205 // AddP ( base == address )
2206 //
2207 Node *base = addp->in(AddPNode::Base);
2208 if (base->uncast()->is_top()) { // The AddP case #3 and #6.
2209 base = addp->in(AddPNode::Address);
2210 while (base->is_AddP()) {
2211 // Case #6 (unsafe access) may have several chained AddP nodes.
2212 assert(base->in(AddPNode::Base)->uncast()->is_top(), "expected unsafe access address only");
2213 base = base->in(AddPNode::Address);
2214 }
2215 Node* uncast_base = base->uncast();
2216 int opcode = uncast_base->Opcode();
2217 assert(opcode == Op_ConP || opcode == Op_ThreadLocal ||
2218 opcode == Op_CastX2P || uncast_base->is_DecodeNarrowPtr() ||
2219 (uncast_base->is_Mem() && (uncast_base->bottom_type()->isa_rawptr() != NULL)) ||
2220 (uncast_base->is_Proj() && uncast_base->in(0)->is_Allocate()), "sanity");
2221 }
2222 return base;
2223 }
2224
2225 Node* ConnectionGraph::find_second_addp(Node* addp, Node* n) {
2226 assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
2227 Node* addp2 = addp->raw_out(0);
2228 if (addp->outcnt() == 1 && addp2->is_AddP() &&
2229 addp2->in(AddPNode::Base) == n &&
2230 addp2->in(AddPNode::Address) == addp) {
2231 assert(addp->in(AddPNode::Base) == n, "expecting the same base");
2232 //
2233 // Find array's offset to push it on worklist first and
2234 // as result process an array's element offset first (pushed second)
2235 // to avoid CastPP for the array's offset.
2236 // Otherwise the inserted CastPP (LocalVar) will point to what
2237 // the AddP (Field) points to. Which would be wrong since
2238 // the algorithm expects the CastPP has the same point as
2239 // as AddP's base CheckCastPP (LocalVar).
2240 //
2241 // ArrayAllocation
2242 // |
2243 // CheckCastPP
2244 // |
2245 // memProj (from ArrayAllocation CheckCastPP)
2246 // | ||
2247 // | || Int (element index)
2248 // | || | ConI (log(element size))
2249 // | || | /
2250 // | || LShift
2251 // | || /
2252 // | AddP (array's element offset)
2253 // | |
2254 // | | ConI (array's offset: #12(32-bits) or #24(64-bits))
2255 // | / /
2256 // AddP (array's offset)
2257 // |
2258 // Load/Store (memory operation on array's element)
2259 //
2260 return addp2;
2261 }
2262 return NULL;
2263 }
2264
2265 //
2266 // Adjust the type and inputs of an AddP which computes the
2267 // address of a field of an instance
2268 //
2269 bool ConnectionGraph::split_AddP(Node *addp, Node *base) {
2270 PhaseGVN* igvn = _igvn;
2271 const TypeOopPtr *base_t = igvn->type(base)->isa_oopptr();
2272 assert(base_t != NULL && base_t->is_known_instance(), "expecting instance oopptr");
2273 const TypeOopPtr *t = igvn->type(addp)->isa_oopptr();
2274 if (t == NULL) {
2275 // We are computing a raw address for a store captured by an Initialize
2276 // compute an appropriate address type (cases #3 and #5).
2277 assert(igvn->type(addp) == TypeRawPtr::NOTNULL, "must be raw pointer");
2278 assert(addp->in(AddPNode::Address)->is_Proj(), "base of raw address must be result projection from allocation");
2279 intptr_t offs = (int)igvn->find_intptr_t_con(addp->in(AddPNode::Offset), Type::OffsetBot);
2280 assert(offs != Type::OffsetBot, "offset must be a constant");
2281 t = base_t->add_offset(offs)->is_oopptr();
2282 }
2283 int inst_id = base_t->instance_id();
2284 assert(!t->is_known_instance() || t->instance_id() == inst_id,
2285 "old type must be non-instance or match new type");
2286
2287 // The type 't' could be subclass of 'base_t'.
2288 // As result t->offset() could be large then base_t's size and it will
2289 // cause the failure in add_offset() with narrow oops since TypeOopPtr()
2290 // constructor verifies correctness of the offset.
2291 //
2292 // It could happened on subclass's branch (from the type profiling
2293 // inlining) which was not eliminated during parsing since the exactness
2294 // of the allocation type was not propagated to the subclass type check.
2295 //
2296 // Or the type 't' could be not related to 'base_t' at all.
2297 // It could happened when CHA type is different from MDO type on a dead path
2298 // (for example, from instanceof check) which is not collapsed during parsing.
2299 //
2300 // Do nothing for such AddP node and don't process its users since
2301 // this code branch will go away.
2302 //
2303 if (!t->is_known_instance() &&
2304 !base_t->klass()->is_subtype_of(t->klass())) {
2305 return false; // bail out
2306 }
2307 const TypeOopPtr *tinst = base_t->add_offset(t->offset())->is_oopptr();
2308 // Do NOT remove the next line: ensure a new alias index is allocated
2309 // for the instance type. Note: C++ will not remove it since the call
2310 // has side effect.
2311 int alias_idx = _compile->get_alias_index(tinst);
2312 igvn->set_type(addp, tinst);
2313 // record the allocation in the node map
2314 set_map(addp, get_map(base->_idx));
2315 // Set addp's Base and Address to 'base'.
2316 Node *abase = addp->in(AddPNode::Base);
2317 Node *adr = addp->in(AddPNode::Address);
2318 if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
2319 adr->in(0)->_idx == (uint)inst_id) {
2320 // Skip AddP cases #3 and #5.
2321 } else {
2322 assert(!abase->is_top(), "sanity"); // AddP case #3
2323 if (abase != base) {
2324 igvn->hash_delete(addp);
2325 addp->set_req(AddPNode::Base, base);
2326 if (abase == adr) {
2327 addp->set_req(AddPNode::Address, base);
2328 } else {
2329 // AddP case #4 (adr is array's element offset AddP node)
2330 #ifdef ASSERT
2331 const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
2332 assert(adr->is_AddP() && atype != NULL &&
2333 atype->instance_id() == inst_id, "array's element offset should be processed first");
2334 #endif
2335 }
2336 igvn->hash_insert(addp);
2337 }
2338 }
2339 // Put on IGVN worklist since at least addp's type was changed above.
2340 record_for_optimizer(addp);
2341 return true;
2342 }
2343
2344 //
2345 // Create a new version of orig_phi if necessary. Returns either the newly
2346 // created phi or an existing phi. Sets create_new to indicate whether a new
2347 // phi was created. Cache the last newly created phi in the node map.
2348 //
2349 PhiNode *ConnectionGraph::create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist, bool &new_created) {
2350 Compile *C = _compile;
2351 PhaseGVN* igvn = _igvn;
2352 new_created = false;
2353 int phi_alias_idx = C->get_alias_index(orig_phi->adr_type());
2354 // nothing to do if orig_phi is bottom memory or matches alias_idx
2355 if (phi_alias_idx == alias_idx) {
2356 return orig_phi;
2357 }
2358 // Have we recently created a Phi for this alias index?
2359 PhiNode *result = get_map_phi(orig_phi->_idx);
2360 if (result != NULL && C->get_alias_index(result->adr_type()) == alias_idx) {
2361 return result;
2362 }
2363 // Previous check may fail when the same wide memory Phi was split into Phis
2364 // for different memory slices. Search all Phis for this region.
2365 if (result != NULL) {
2366 Node* region = orig_phi->in(0);
2367 for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
2368 Node* phi = region->fast_out(i);
2369 if (phi->is_Phi() &&
2370 C->get_alias_index(phi->as_Phi()->adr_type()) == alias_idx) {
2371 assert(phi->_idx >= nodes_size(), "only new Phi per instance memory slice");
2372 return phi->as_Phi();
2373 }
2374 }
2375 }
2376 if ((int) (C->live_nodes() + 2*NodeLimitFudgeFactor) > MaxNodeLimit) {
2377 if (C->do_escape_analysis() == true && !C->failing()) {
2378 // Retry compilation without escape analysis.
2379 // If this is the first failure, the sentinel string will "stick"
2380 // to the Compile object, and the C2Compiler will see it and retry.
2381 C->record_failure(C2Compiler::retry_no_escape_analysis());
2382 }
2383 return NULL;
2384 }
2385 orig_phi_worklist.append_if_missing(orig_phi);
2386 const TypePtr *atype = C->get_adr_type(alias_idx);
2387 result = PhiNode::make(orig_phi->in(0), NULL, Type::MEMORY, atype);
2388 C->copy_node_notes_to(result, orig_phi);
2389 igvn->set_type(result, result->bottom_type());
2390 record_for_optimizer(result);
2391 set_map(orig_phi, result);
2392 new_created = true;
2393 return result;
2394 }
2395
2396 //
2397 // Return a new version of Memory Phi "orig_phi" with the inputs having the
2398 // specified alias index.
2399 //
2400 PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist) {
2401 assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
2402 Compile *C = _compile;
2403 PhaseGVN* igvn = _igvn;
2404 bool new_phi_created;
2405 PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, new_phi_created);
2406 if (!new_phi_created) {
2407 return result;
2408 }
2409 GrowableArray<PhiNode *> phi_list;
2410 GrowableArray<uint> cur_input;
2411 PhiNode *phi = orig_phi;
2412 uint idx = 1;
2413 bool finished = false;
2414 while(!finished) {
2415 while (idx < phi->req()) {
2416 Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist);
2417 if (mem != NULL && mem->is_Phi()) {
2418 PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, new_phi_created);
2419 if (new_phi_created) {
2420 // found an phi for which we created a new split, push current one on worklist and begin
2421 // processing new one
2422 phi_list.push(phi);
2423 cur_input.push(idx);
2424 phi = mem->as_Phi();
2425 result = newphi;
2426 idx = 1;
2427 continue;
2428 } else {
2429 mem = newphi;
2430 }
2431 }
2432 if (C->failing()) {
2433 return NULL;
2434 }
2435 result->set_req(idx++, mem);
2436 }
2437 #ifdef ASSERT
2438 // verify that the new Phi has an input for each input of the original
2439 assert( phi->req() == result->req(), "must have same number of inputs.");
2440 assert( result->in(0) != NULL && result->in(0) == phi->in(0), "regions must match");
2441 #endif
2442 // Check if all new phi's inputs have specified alias index.
2443 // Otherwise use old phi.
2444 for (uint i = 1; i < phi->req(); i++) {
2445 Node* in = result->in(i);
2446 assert((phi->in(i) == NULL) == (in == NULL), "inputs must correspond.");
2447 }
2448 // we have finished processing a Phi, see if there are any more to do
2449 finished = (phi_list.length() == 0 );
2450 if (!finished) {
2451 phi = phi_list.pop();
2452 idx = cur_input.pop();
2453 PhiNode *prev_result = get_map_phi(phi->_idx);
2454 prev_result->set_req(idx++, result);
2455 result = prev_result;
2456 }
2457 }
2458 return result;
2459 }
2460
2461 //
2462 // The next methods are derived from methods in MemNode.
2463 //
2464 Node* ConnectionGraph::step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *toop) {
2465 Node *mem = mmem;
2466 // TypeOopPtr::NOTNULL+any is an OOP with unknown offset - generally
2467 // means an array I have not precisely typed yet. Do not do any
2468 // alias stuff with it any time soon.
2469 if (toop->base() != Type::AnyPtr &&
2470 !(toop->klass() != NULL &&
2471 toop->klass()->is_java_lang_Object() &&
2472 toop->offset() == Type::OffsetBot)) {
2473 mem = mmem->memory_at(alias_idx);
2474 // Update input if it is progress over what we have now
2475 }
2476 return mem;
2477 }
2478
2479 //
2480 // Move memory users to their memory slices.
2481 //
2482 void ConnectionGraph::move_inst_mem(Node* n, GrowableArray<PhiNode *> &orig_phis) {
2483 Compile* C = _compile;
2484 PhaseGVN* igvn = _igvn;
2485 const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr();
2486 assert(tp != NULL, "ptr type");
2487 int alias_idx = C->get_alias_index(tp);
2488 int general_idx = C->get_general_index(alias_idx);
2489
2490 // Move users first
2491 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2492 Node* use = n->fast_out(i);
2493 if (use->is_MergeMem()) {
2494 MergeMemNode* mmem = use->as_MergeMem();
2495 assert(n == mmem->memory_at(alias_idx), "should be on instance memory slice");
2496 if (n != mmem->memory_at(general_idx) || alias_idx == general_idx) {
2497 continue; // Nothing to do
2498 }
2499 // Replace previous general reference to mem node.
2500 uint orig_uniq = C->unique();
2501 Node* m = find_inst_mem(n, general_idx, orig_phis);
2502 assert(orig_uniq == C->unique(), "no new nodes");
2503 mmem->set_memory_at(general_idx, m);
2504 --imax;
2505 --i;
2506 } else if (use->is_MemBar()) {
2507 assert(!use->is_Initialize(), "initializing stores should not be moved");
2508 if (use->req() > MemBarNode::Precedent &&
2509 use->in(MemBarNode::Precedent) == n) {
2510 // Don't move related membars.
2511 record_for_optimizer(use);
2512 continue;
2513 }
2514 tp = use->as_MemBar()->adr_type()->isa_ptr();
2515 if (tp != NULL && C->get_alias_index(tp) == alias_idx ||
2516 alias_idx == general_idx) {
2517 continue; // Nothing to do
2518 }
2519 // Move to general memory slice.
2520 uint orig_uniq = C->unique();
2521 Node* m = find_inst_mem(n, general_idx, orig_phis);
2522 assert(orig_uniq == C->unique(), "no new nodes");
2523 igvn->hash_delete(use);
2524 imax -= use->replace_edge(n, m);
2525 igvn->hash_insert(use);
2526 record_for_optimizer(use);
2527 --i;
2528 #ifdef ASSERT
2529 } else if (use->is_Mem()) {
2530 if (use->Opcode() == Op_StoreCM && use->in(MemNode::OopStore) == n) {
2531 // Don't move related cardmark.
2532 continue;
2533 }
2534 // Memory nodes should have new memory input.
2535 tp = igvn->type(use->in(MemNode::Address))->isa_ptr();
2536 assert(tp != NULL, "ptr type");
2537 int idx = C->get_alias_index(tp);
2538 assert(get_map(use->_idx) != NULL || idx == alias_idx,
2539 "Following memory nodes should have new memory input or be on the same memory slice");
2540 } else if (use->is_Phi()) {
2541 // Phi nodes should be split and moved already.
2542 tp = use->as_Phi()->adr_type()->isa_ptr();
2543 assert(tp != NULL, "ptr type");
2544 int idx = C->get_alias_index(tp);
2545 assert(idx == alias_idx, "Following Phi nodes should be on the same memory slice");
2546 } else {
2547 use->dump();
2548 assert(false, "should not be here");
2549 #endif
2550 }
2551 }
2552 }
2553
2554 //
2555 // Search memory chain of "mem" to find a MemNode whose address
2556 // is the specified alias index.
2557 //
2558 Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArray<PhiNode *> &orig_phis) {
2559 if (orig_mem == NULL)
2560 return orig_mem;
2561 Compile* C = _compile;
2562 PhaseGVN* igvn = _igvn;
2563 const TypeOopPtr *toop = C->get_adr_type(alias_idx)->isa_oopptr();
2564 bool is_instance = (toop != NULL) && toop->is_known_instance();
2565 Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
2566 Node *prev = NULL;
2567 Node *result = orig_mem;
2568 while (prev != result) {
2569 prev = result;
2570 if (result == start_mem)
2571 break; // hit one of our sentinels
2572 if (result->is_Mem()) {
2573 const Type *at = igvn->type(result->in(MemNode::Address));
2574 if (at == Type::TOP)
2575 break; // Dead
2576 assert (at->isa_ptr() != NULL, "pointer type required.");
2577 int idx = C->get_alias_index(at->is_ptr());
2578 if (idx == alias_idx)
2579 break; // Found
2580 if (!is_instance && (at->isa_oopptr() == NULL ||
2581 !at->is_oopptr()->is_known_instance())) {
2582 break; // Do not skip store to general memory slice.
2583 }
2584 result = result->in(MemNode::Memory);
2585 }
2586 if (!is_instance)
2587 continue; // don't search further for non-instance types
2588 // skip over a call which does not affect this memory slice
2589 if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) {
2590 Node *proj_in = result->in(0);
2591 if (proj_in->is_Allocate() && proj_in->_idx == (uint)toop->instance_id()) {
2592 break; // hit one of our sentinels
2593 } else if (proj_in->is_Call()) {
2594 CallNode *call = proj_in->as_Call();
2595 if (!call->may_modify(toop, igvn)) {
2596 result = call->in(TypeFunc::Memory);
2597 }
2598 } else if (proj_in->is_Initialize()) {
2599 AllocateNode* alloc = proj_in->as_Initialize()->allocation();
2600 // Stop if this is the initialization for the object instance which
2601 // which contains this memory slice, otherwise skip over it.
2602 if (alloc == NULL || alloc->_idx != (uint)toop->instance_id()) {
2603 result = proj_in->in(TypeFunc::Memory);
2604 }
2605 } else if (proj_in->is_MemBar()) {
2606 result = proj_in->in(TypeFunc::Memory);
2607 }
2608 } else if (result->is_MergeMem()) {
2609 MergeMemNode *mmem = result->as_MergeMem();
2610 result = step_through_mergemem(mmem, alias_idx, toop);
2611 if (result == mmem->base_memory()) {
2612 // Didn't find instance memory, search through general slice recursively.
2613 result = mmem->memory_at(C->get_general_index(alias_idx));
2614 result = find_inst_mem(result, alias_idx, orig_phis);
2615 if (C->failing()) {
2616 return NULL;
2617 }
2618 mmem->set_memory_at(alias_idx, result);
2619 }
2620 } else if (result->is_Phi() &&
2621 C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) {
2622 Node *un = result->as_Phi()->unique_input(igvn);
2623 if (un != NULL) {
2624 orig_phis.append_if_missing(result->as_Phi());
2625 result = un;
2626 } else {
2627 break;
2628 }
2629 } else if (result->is_ClearArray()) {
2630 if (!ClearArrayNode::step_through(&result, (uint)toop->instance_id(), igvn)) {
2631 // Can not bypass initialization of the instance
2632 // we are looking for.
2633 break;
2634 }
2635 // Otherwise skip it (the call updated 'result' value).
2636 } else if (result->Opcode() == Op_SCMemProj) {
2637 Node* mem = result->in(0);
2638 Node* adr = NULL;
2639 if (mem->is_LoadStore()) {
2640 adr = mem->in(MemNode::Address);
2641 } else {
2642 assert(mem->Opcode() == Op_EncodeISOArray, "sanity");
2643 adr = mem->in(3); // Memory edge corresponds to destination array
2644 }
2645 const Type *at = igvn->type(adr);
2646 if (at != Type::TOP) {
2647 assert (at->isa_ptr() != NULL, "pointer type required.");
2648 int idx = C->get_alias_index(at->is_ptr());
2649 assert(idx != alias_idx, "Object is not scalar replaceable if a LoadStore node access its field");
2650 break;
2651 }
2652 result = mem->in(MemNode::Memory);
2653 }
2654 }
2655 if (result->is_Phi()) {
2656 PhiNode *mphi = result->as_Phi();
2657 assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
2658 const TypePtr *t = mphi->adr_type();
2659 if (!is_instance) {
2660 // Push all non-instance Phis on the orig_phis worklist to update inputs
2661 // during Phase 4 if needed.
2662 orig_phis.append_if_missing(mphi);
2663 } else if (C->get_alias_index(t) != alias_idx) {
2664 // Create a new Phi with the specified alias index type.
2665 result = split_memory_phi(mphi, alias_idx, orig_phis);
2666 }
2667 }
2668 // the result is either MemNode, PhiNode, InitializeNode.
2669 return result;
2670 }
2671
2672 //
2673 // Convert the types of unescaped object to instance types where possible,
2674 // propagate the new type information through the graph, and update memory
2675 // edges and MergeMem inputs to reflect the new type.
2676 //
2677 // We start with allocations (and calls which may be allocations) on alloc_worklist.
2678 // The processing is done in 4 phases:
2679 //
2680 // Phase 1: Process possible allocations from alloc_worklist. Create instance
2681 // types for the CheckCastPP for allocations where possible.
2682 // Propagate the the new types through users as follows:
2683 // casts and Phi: push users on alloc_worklist
2684 // AddP: cast Base and Address inputs to the instance type
2685 // push any AddP users on alloc_worklist and push any memnode
2686 // users onto memnode_worklist.
2687 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
2688 // search the Memory chain for a store with the appropriate type
2689 // address type. If a Phi is found, create a new version with
2690 // the appropriate memory slices from each of the Phi inputs.
2691 // For stores, process the users as follows:
2692 // MemNode: push on memnode_worklist
2693 // MergeMem: push on mergemem_worklist
2694 // Phase 3: Process MergeMem nodes from mergemem_worklist. Walk each memory slice
2695 // moving the first node encountered of each instance type to the
2696 // the input corresponding to its alias index.
2697 // appropriate memory slice.
2698 // Phase 4: Update the inputs of non-instance memory Phis and the Memory input of memnodes.
2699 //
2700 // In the following example, the CheckCastPP nodes are the cast of allocation
2701 // results and the allocation of node 29 is unescaped and eligible to be an
2702 // instance type.
2703 //
2704 // We start with:
2705 //
2706 // 7 Parm #memory
2707 // 10 ConI "12"
2708 // 19 CheckCastPP "Foo"
2709 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2710 // 29 CheckCastPP "Foo"
2711 // 30 AddP _ 29 29 10 Foo+12 alias_index=4
2712 //
2713 // 40 StoreP 25 7 20 ... alias_index=4
2714 // 50 StoreP 35 40 30 ... alias_index=4
2715 // 60 StoreP 45 50 20 ... alias_index=4
2716 // 70 LoadP _ 60 30 ... alias_index=4
2717 // 80 Phi 75 50 60 Memory alias_index=4
2718 // 90 LoadP _ 80 30 ... alias_index=4
2719 // 100 LoadP _ 80 20 ... alias_index=4
2720 //
2721 //
2722 // Phase 1 creates an instance type for node 29 assigning it an instance id of 24
2723 // and creating a new alias index for node 30. This gives:
2724 //
2725 // 7 Parm #memory
2726 // 10 ConI "12"
2727 // 19 CheckCastPP "Foo"
2728 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2729 // 29 CheckCastPP "Foo" iid=24
2730 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
2731 //
2732 // 40 StoreP 25 7 20 ... alias_index=4
2733 // 50 StoreP 35 40 30 ... alias_index=6
2734 // 60 StoreP 45 50 20 ... alias_index=4
2735 // 70 LoadP _ 60 30 ... alias_index=6
2736 // 80 Phi 75 50 60 Memory alias_index=4
2737 // 90 LoadP _ 80 30 ... alias_index=6
2738 // 100 LoadP _ 80 20 ... alias_index=4
2739 //
2740 // In phase 2, new memory inputs are computed for the loads and stores,
2741 // And a new version of the phi is created. In phase 4, the inputs to
2742 // node 80 are updated and then the memory nodes are updated with the
2743 // values computed in phase 2. This results in:
2744 //
2745 // 7 Parm #memory
2746 // 10 ConI "12"
2747 // 19 CheckCastPP "Foo"
2748 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2749 // 29 CheckCastPP "Foo" iid=24
2750 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
2751 //
2752 // 40 StoreP 25 7 20 ... alias_index=4
2753 // 50 StoreP 35 7 30 ... alias_index=6
2754 // 60 StoreP 45 40 20 ... alias_index=4
2755 // 70 LoadP _ 50 30 ... alias_index=6
2756 // 80 Phi 75 40 60 Memory alias_index=4
2757 // 120 Phi 75 50 50 Memory alias_index=6
2758 // 90 LoadP _ 120 30 ... alias_index=6
2759 // 100 LoadP _ 80 20 ... alias_index=4
2760 //
2761 void ConnectionGraph::split_unique_types(GrowableArray<Node *> &alloc_worklist) {
2762 GrowableArray<Node *> memnode_worklist;
2763 GrowableArray<PhiNode *> orig_phis;
2764 PhaseIterGVN *igvn = _igvn;
2765 uint new_index_start = (uint) _compile->num_alias_types();
2766 Arena* arena = Thread::current()->resource_area();
2767 VectorSet visited(arena);
2768 ideal_nodes.clear(); // Reset for use with set_map/get_map.
2769 uint unique_old = _compile->unique();
2770
2771 // Phase 1: Process possible allocations from alloc_worklist.
2772 // Create instance types for the CheckCastPP for allocations where possible.
2773 //
2774 // (Note: don't forget to change the order of the second AddP node on
2775 // the alloc_worklist if the order of the worklist processing is changed,
2776 // see the comment in find_second_addp().)
2777 //
2778 while (alloc_worklist.length() != 0) {
2779 Node *n = alloc_worklist.pop();
2780 uint ni = n->_idx;
2781 if (n->is_Call()) {
2782 CallNode *alloc = n->as_Call();
2783 // copy escape information to call node
2784 PointsToNode* ptn = ptnode_adr(alloc->_idx);
2785 PointsToNode::EscapeState es = ptn->escape_state();
2786 // We have an allocation or call which returns a Java object,
2787 // see if it is unescaped.
2788 if (es != PointsToNode::NoEscape || !ptn->scalar_replaceable())
2789 continue;
2790 // Find CheckCastPP for the allocate or for the return value of a call
2791 n = alloc->result_cast();
2792 if (n == NULL) { // No uses except Initialize node
2793 if (alloc->is_Allocate()) {
2794 // Set the scalar_replaceable flag for allocation
2795 // so it could be eliminated if it has no uses.
2796 alloc->as_Allocate()->_is_scalar_replaceable = true;
2797 }
2798 if (alloc->is_CallStaticJava()) {
2799 // Set the scalar_replaceable flag for boxing method
2800 // so it could be eliminated if it has no uses.
2801 alloc->as_CallStaticJava()->_is_scalar_replaceable = true;
2802 }
2803 continue;
2804 }
2805 if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
2806 assert(!alloc->is_Allocate(), "allocation should have unique type");
2807 continue;
2808 }
2809
2810 // The inline code for Object.clone() casts the allocation result to
2811 // java.lang.Object and then to the actual type of the allocated
2812 // object. Detect this case and use the second cast.
2813 // Also detect j.l.reflect.Array.newInstance(jobject, jint) case when
2814 // the allocation result is cast to java.lang.Object and then
2815 // to the actual Array type.
2816 if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL
2817 && (alloc->is_AllocateArray() ||
2818 igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeKlassPtr::OBJECT)) {
2819 Node *cast2 = NULL;
2820 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2821 Node *use = n->fast_out(i);
2822 if (use->is_CheckCastPP()) {
2823 cast2 = use;
2824 break;
2825 }
2826 }
2827 if (cast2 != NULL) {
2828 n = cast2;
2829 } else {
2830 // Non-scalar replaceable if the allocation type is unknown statically
2831 // (reflection allocation), the object can't be restored during
2832 // deoptimization without precise type.
2833 continue;
2834 }
2835 }
2836 if (alloc->is_Allocate()) {
2837 // Set the scalar_replaceable flag for allocation
2838 // so it could be eliminated.
2839 alloc->as_Allocate()->_is_scalar_replaceable = true;
2840 }
2841 if (alloc->is_CallStaticJava()) {
2842 // Set the scalar_replaceable flag for boxing method
2843 // so it could be eliminated.
2844 alloc->as_CallStaticJava()->_is_scalar_replaceable = true;
2845 }
2846 set_escape_state(ptnode_adr(n->_idx), es); // CheckCastPP escape state
2847 // in order for an object to be scalar-replaceable, it must be:
2848 // - a direct allocation (not a call returning an object)
2849 // - non-escaping
2850 // - eligible to be a unique type
2851 // - not determined to be ineligible by escape analysis
2852 set_map(alloc, n);
2853 set_map(n, alloc);
2854 const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
2855 if (t == NULL)
2856 continue; // not a TypeOopPtr
2857 const TypeOopPtr* tinst = t->cast_to_exactness(true)->is_oopptr()->cast_to_instance_id(ni);
2858 igvn->hash_delete(n);
2859 igvn->set_type(n, tinst);
2860 n->raise_bottom_type(tinst);
2861 igvn->hash_insert(n);
2862 record_for_optimizer(n);
2863 if (alloc->is_Allocate() && (t->isa_instptr() || t->isa_aryptr())) {
2864
2865 // First, put on the worklist all Field edges from Connection Graph
2866 // which is more accurate then putting immediate users from Ideal Graph.
2867 for (EdgeIterator e(ptn); e.has_next(); e.next()) {
2868 PointsToNode* tgt = e.get();
2869 Node* use = tgt->ideal_node();
2870 assert(tgt->is_Field() && use->is_AddP(),
2871 "only AddP nodes are Field edges in CG");
2872 if (use->outcnt() > 0) { // Don't process dead nodes
2873 Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
2874 if (addp2 != NULL) {
2875 assert(alloc->is_AllocateArray(),"array allocation was expected");
2876 alloc_worklist.append_if_missing(addp2);
2877 }
2878 alloc_worklist.append_if_missing(use);
2879 }
2880 }
2881
2882 // An allocation may have an Initialize which has raw stores. Scan
2883 // the users of the raw allocation result and push AddP users
2884 // on alloc_worklist.
2885 Node *raw_result = alloc->proj_out(TypeFunc::Parms);
2886 assert (raw_result != NULL, "must have an allocation result");
2887 for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
2888 Node *use = raw_result->fast_out(i);
2889 if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
2890 Node* addp2 = find_second_addp(use, raw_result);
2891 if (addp2 != NULL) {
2892 assert(alloc->is_AllocateArray(),"array allocation was expected");
2893 alloc_worklist.append_if_missing(addp2);
2894 }
2895 alloc_worklist.append_if_missing(use);
2896 } else if (use->is_MemBar()) {
2897 memnode_worklist.append_if_missing(use);
2898 }
2899 }
2900 }
2901 } else if (n->is_AddP()) {
2902 JavaObjectNode* jobj = unique_java_object(get_addp_base(n));
2903 if (jobj == NULL || jobj == phantom_obj) {
2904 #ifdef ASSERT
2905 ptnode_adr(get_addp_base(n)->_idx)->dump();
2906 ptnode_adr(n->_idx)->dump();
2907 assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
2908 #endif
2909 _compile->record_failure(C2Compiler::retry_no_escape_analysis());
2910 return;
2911 }
2912 Node *base = get_map(jobj->idx()); // CheckCastPP node
2913 if (!split_AddP(n, base)) continue; // wrong type from dead path
2914 } else if (n->is_Phi() ||
2915 n->is_CheckCastPP() ||
2916 n->is_EncodeP() ||
2917 n->is_DecodeN() ||
2918 (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
2919 if (visited.test_set(n->_idx)) {
2920 assert(n->is_Phi(), "loops only through Phi's");
2921 continue; // already processed
2922 }
2923 JavaObjectNode* jobj = unique_java_object(n);
2924 if (jobj == NULL || jobj == phantom_obj) {
2925 #ifdef ASSERT
2926 ptnode_adr(n->_idx)->dump();
2927 assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
2928 #endif
2929 _compile->record_failure(C2Compiler::retry_no_escape_analysis());
2930 return;
2931 } else {
2932 Node *val = get_map(jobj->idx()); // CheckCastPP node
2933 TypeNode *tn = n->as_Type();
2934 const TypeOopPtr* tinst = igvn->type(val)->isa_oopptr();
2935 assert(tinst != NULL && tinst->is_known_instance() &&
2936 tinst->instance_id() == jobj->idx() , "instance type expected.");
2937
2938 const Type *tn_type = igvn->type(tn);
2939 const TypeOopPtr *tn_t;
2940 if (tn_type->isa_narrowoop()) {
2941 tn_t = tn_type->make_ptr()->isa_oopptr();
2942 } else {
2943 tn_t = tn_type->isa_oopptr();
2944 }
2945 if (tn_t != NULL && tinst->klass()->is_subtype_of(tn_t->klass())) {
2946 if (tn_type->isa_narrowoop()) {
2947 tn_type = tinst->make_narrowoop();
2948 } else {
2949 tn_type = tinst;
2950 }
2951 igvn->hash_delete(tn);
2952 igvn->set_type(tn, tn_type);
2953 tn->set_type(tn_type);
2954 igvn->hash_insert(tn);
2955 record_for_optimizer(n);
2956 } else {
2957 assert(tn_type == TypePtr::NULL_PTR ||
2958 tn_t != NULL && !tinst->klass()->is_subtype_of(tn_t->klass()),
2959 "unexpected type");
2960 continue; // Skip dead path with different type
2961 }
2962 }
2963 } else {
2964 debug_only(n->dump();)
2965 assert(false, "EA: unexpected node");
2966 continue;
2967 }
2968 // push allocation's users on appropriate worklist
2969 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2970 Node *use = n->fast_out(i);
2971 if(use->is_Mem() && use->in(MemNode::Address) == n) {
2972 // Load/store to instance's field
2973 memnode_worklist.append_if_missing(use);
2974 } else if (use->is_MemBar()) {
2975 if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
2976 memnode_worklist.append_if_missing(use);
2977 }
2978 } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
2979 Node* addp2 = find_second_addp(use, n);
2980 if (addp2 != NULL) {
2981 alloc_worklist.append_if_missing(addp2);
2982 }
2983 alloc_worklist.append_if_missing(use);
2984 } else if (use->is_Phi() ||
2985 use->is_CheckCastPP() ||
2986 use->is_EncodeNarrowPtr() ||
2987 use->is_DecodeNarrowPtr() ||
2988 (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
2989 alloc_worklist.append_if_missing(use);
2990 #ifdef ASSERT
2991 } else if (use->is_Mem()) {
2992 assert(use->in(MemNode::Address) != n, "EA: missing allocation reference path");
2993 } else if (use->is_MergeMem()) {
2994 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
2995 } else if (use->is_SafePoint()) {
2996 // Look for MergeMem nodes for calls which reference unique allocation
2997 // (through CheckCastPP nodes) even for debug info.
2998 Node* m = use->in(TypeFunc::Memory);
2999 if (m->is_MergeMem()) {
3000 assert(_mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3001 }
3002 } else if (use->Opcode() == Op_EncodeISOArray) {
3003 if (use->in(MemNode::Memory) == n || use->in(3) == n) {
3004 // EncodeISOArray overwrites destination array
3005 memnode_worklist.append_if_missing(use);
3006 }
3007 } else {
3008 uint op = use->Opcode();
3009 if (!(op == Op_CmpP || op == Op_Conv2B ||
3010 op == Op_CastP2X || op == Op_StoreCM ||
3011 op == Op_FastLock || op == Op_AryEq || op == Op_StrComp ||
3012 op == Op_StrEquals || op == Op_StrIndexOf)) {
3013 n->dump();
3014 use->dump();
3015 assert(false, "EA: missing allocation reference path");
3016 }
3017 #endif
3018 }
3019 }
3020
3021 }
3022 // New alias types were created in split_AddP().
3023 uint new_index_end = (uint) _compile->num_alias_types();
3024 assert(unique_old == _compile->unique(), "there should be no new ideal nodes after Phase 1");
3025
3026 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
3027 // compute new values for Memory inputs (the Memory inputs are not
3028 // actually updated until phase 4.)
3029 if (memnode_worklist.length() == 0)
3030 return; // nothing to do
3031 while (memnode_worklist.length() != 0) {
3032 Node *n = memnode_worklist.pop();
3033 if (visited.test_set(n->_idx))
3034 continue;
3035 if (n->is_Phi() || n->is_ClearArray()) {
3036 // we don't need to do anything, but the users must be pushed
3037 } else if (n->is_MemBar()) { // Initialize, MemBar nodes
3038 // we don't need to do anything, but the users must be pushed
3039 n = n->as_MemBar()->proj_out(TypeFunc::Memory);
3040 if (n == NULL)
3041 continue;
3042 } else if (n->Opcode() == Op_EncodeISOArray) {
3043 // get the memory projection
3044 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3045 Node *use = n->fast_out(i);
3046 if (use->Opcode() == Op_SCMemProj) {
3047 n = use;
3048 break;
3049 }
3050 }
3051 assert(n->Opcode() == Op_SCMemProj, "memory projection required");
3052 } else {
3053 assert(n->is_Mem(), "memory node required.");
3054 Node *addr = n->in(MemNode::Address);
3055 const Type *addr_t = igvn->type(addr);
3056 if (addr_t == Type::TOP)
3057 continue;
3058 assert (addr_t->isa_ptr() != NULL, "pointer type required.");
3059 int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
3060 assert ((uint)alias_idx < new_index_end, "wrong alias index");
3061 Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis);
3062 if (_compile->failing()) {
3063 return;
3064 }
3065 if (mem != n->in(MemNode::Memory)) {
3066 // We delay the memory edge update since we need old one in
3067 // MergeMem code below when instances memory slices are separated.
3068 set_map(n, mem);
3069 }
3070 if (n->is_Load()) {
3071 continue; // don't push users
3072 } else if (n->is_LoadStore()) {
3073 // get the memory projection
3074 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3075 Node *use = n->fast_out(i);
3076 if (use->Opcode() == Op_SCMemProj) {
3077 n = use;
3078 break;
3079 }
3080 }
3081 assert(n->Opcode() == Op_SCMemProj, "memory projection required");
3082 }
3083 }
3084 // push user on appropriate worklist
3085 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3086 Node *use = n->fast_out(i);
3087 if (use->is_Phi() || use->is_ClearArray()) {
3088 memnode_worklist.append_if_missing(use);
3089 } else if (use->is_Mem() && use->in(MemNode::Memory) == n) {
3090 if (use->Opcode() == Op_StoreCM) // Ignore cardmark stores
3091 continue;
3092 memnode_worklist.append_if_missing(use);
3093 } else if (use->is_MemBar()) {
3094 if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
3095 memnode_worklist.append_if_missing(use);
3096 }
3097 #ifdef ASSERT
3098 } else if(use->is_Mem()) {
3099 assert(use->in(MemNode::Memory) != n, "EA: missing memory path");
3100 } else if (use->is_MergeMem()) {
3101 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3102 } else if (use->Opcode() == Op_EncodeISOArray) {
3103 if (use->in(MemNode::Memory) == n || use->in(3) == n) {
3104 // EncodeISOArray overwrites destination array
3105 memnode_worklist.append_if_missing(use);
3106 }
3107 } else {
3108 uint op = use->Opcode();
3109 if (!(op == Op_StoreCM ||
3110 (op == Op_CallLeaf && use->as_CallLeaf()->_name != NULL &&
3111 strcmp(use->as_CallLeaf()->_name, "g1_wb_pre") == 0) ||
3112 op == Op_AryEq || op == Op_StrComp ||
3113 op == Op_StrEquals || op == Op_StrIndexOf)) {
3114 n->dump();
3115 use->dump();
3116 assert(false, "EA: missing memory path");
3117 }
3118 #endif
3119 }
3120 }
3121 }
3122
3123 // Phase 3: Process MergeMem nodes from mergemem_worklist.
3124 // Walk each memory slice moving the first node encountered of each
3125 // instance type to the the input corresponding to its alias index.
3126 uint length = _mergemem_worklist.length();
3127 for( uint next = 0; next < length; ++next ) {
3128 MergeMemNode* nmm = _mergemem_worklist.at(next);
3129 assert(!visited.test_set(nmm->_idx), "should not be visited before");
3130 // Note: we don't want to use MergeMemStream here because we only want to
3131 // scan inputs which exist at the start, not ones we add during processing.
3132 // Note 2: MergeMem may already contains instance memory slices added
3133 // during find_inst_mem() call when memory nodes were processed above.
3134 igvn->hash_delete(nmm);
3135 uint nslices = nmm->req();
3136 for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) {
3137 Node* mem = nmm->in(i);
3138 Node* cur = NULL;
3139 if (mem == NULL || mem->is_top())
3140 continue;
3141 // First, update mergemem by moving memory nodes to corresponding slices
3142 // if their type became more precise since this mergemem was created.
3143 while (mem->is_Mem()) {
3144 const Type *at = igvn->type(mem->in(MemNode::Address));
3145 if (at != Type::TOP) {
3146 assert (at->isa_ptr() != NULL, "pointer type required.");
3147 uint idx = (uint)_compile->get_alias_index(at->is_ptr());
3148 if (idx == i) {
3149 if (cur == NULL)
3150 cur = mem;
3151 } else {
3152 if (idx >= nmm->req() || nmm->is_empty_memory(nmm->in(idx))) {
3153 nmm->set_memory_at(idx, mem);
3154 }
3155 }
3156 }
3157 mem = mem->in(MemNode::Memory);
3158 }
3159 nmm->set_memory_at(i, (cur != NULL) ? cur : mem);
3160 // Find any instance of the current type if we haven't encountered
3161 // already a memory slice of the instance along the memory chain.
3162 for (uint ni = new_index_start; ni < new_index_end; ni++) {
3163 if((uint)_compile->get_general_index(ni) == i) {
3164 Node *m = (ni >= nmm->req()) ? nmm->empty_memory() : nmm->in(ni);
3165 if (nmm->is_empty_memory(m)) {
3166 Node* result = find_inst_mem(mem, ni, orig_phis);
3167 if (_compile->failing()) {
3168 return;
3169 }
3170 nmm->set_memory_at(ni, result);
3171 }
3172 }
3173 }
3174 }
3175 // Find the rest of instances values
3176 for (uint ni = new_index_start; ni < new_index_end; ni++) {
3177 const TypeOopPtr *tinst = _compile->get_adr_type(ni)->isa_oopptr();
3178 Node* result = step_through_mergemem(nmm, ni, tinst);
3179 if (result == nmm->base_memory()) {
3180 // Didn't find instance memory, search through general slice recursively.
3181 result = nmm->memory_at(_compile->get_general_index(ni));
3182 result = find_inst_mem(result, ni, orig_phis);
3183 if (_compile->failing()) {
3184 return;
3185 }
3186 nmm->set_memory_at(ni, result);
3187 }
3188 }
3189 igvn->hash_insert(nmm);
3190 record_for_optimizer(nmm);
3191 }
3192
3193 // Phase 4: Update the inputs of non-instance memory Phis and
3194 // the Memory input of memnodes
3195 // First update the inputs of any non-instance Phi's from
3196 // which we split out an instance Phi. Note we don't have
3197 // to recursively process Phi's encounted on the input memory
3198 // chains as is done in split_memory_phi() since they will
3199 // also be processed here.
3200 for (int j = 0; j < orig_phis.length(); j++) {
3201 PhiNode *phi = orig_phis.at(j);
3202 int alias_idx = _compile->get_alias_index(phi->adr_type());
3203 igvn->hash_delete(phi);
3204 for (uint i = 1; i < phi->req(); i++) {
3205 Node *mem = phi->in(i);
3206 Node *new_mem = find_inst_mem(mem, alias_idx, orig_phis);
3207 if (_compile->failing()) {
3208 return;
3209 }
3210 if (mem != new_mem) {
3211 phi->set_req(i, new_mem);
3212 }
3213 }
3214 igvn->hash_insert(phi);
3215 record_for_optimizer(phi);
3216 }
3217
3218 // Update the memory inputs of MemNodes with the value we computed
3219 // in Phase 2 and move stores memory users to corresponding memory slices.
3220 // Disable memory split verification code until the fix for 6984348.
3221 // Currently it produces false negative results since it does not cover all cases.
3222 #if 0 // ifdef ASSERT
3223 visited.Reset();
3224 Node_Stack old_mems(arena, _compile->unique() >> 2);
3225 #endif
3226 for (uint i = 0; i < ideal_nodes.size(); i++) {
3227 Node* n = ideal_nodes.at(i);
3228 Node* nmem = get_map(n->_idx);
3229 assert(nmem != NULL, "sanity");
3230 if (n->is_Mem()) {
3231 #if 0 // ifdef ASSERT
3232 Node* old_mem = n->in(MemNode::Memory);
3233 if (!visited.test_set(old_mem->_idx)) {
3234 old_mems.push(old_mem, old_mem->outcnt());
3235 }
3236 #endif
3237 assert(n->in(MemNode::Memory) != nmem, "sanity");
3238 if (!n->is_Load()) {
3239 // Move memory users of a store first.
3240 move_inst_mem(n, orig_phis);
3241 }
3242 // Now update memory input
3243 igvn->hash_delete(n);
3244 n->set_req(MemNode::Memory, nmem);
3245 igvn->hash_insert(n);
3246 record_for_optimizer(n);
3247 } else {
3248 assert(n->is_Allocate() || n->is_CheckCastPP() ||
3249 n->is_AddP() || n->is_Phi(), "unknown node used for set_map()");
3250 }
3251 }
3252 #if 0 // ifdef ASSERT
3253 // Verify that memory was split correctly
3254 while (old_mems.is_nonempty()) {
3255 Node* old_mem = old_mems.node();
3256 uint old_cnt = old_mems.index();
3257 old_mems.pop();
3258 assert(old_cnt == old_mem->outcnt(), "old mem could be lost");
3259 }
3260 #endif
3261 }
3262
3263 #ifndef PRODUCT
3264 static const char *node_type_names[] = {
3265 "UnknownType",
3266 "JavaObject",
3267 "LocalVar",
3268 "Field",
3269 "Arraycopy"
3270 };
3271
3272 static const char *esc_names[] = {
3273 "UnknownEscape",
3274 "NoEscape",
3275 "ArgEscape",
3276 "GlobalEscape"
3277 };
3278
3279 void PointsToNode::dump(bool print_state) const {
3280 NodeType nt = node_type();
3281 tty->print("%s ", node_type_names[(int) nt]);
3282 if (print_state) {
3283 EscapeState es = escape_state();
3284 EscapeState fields_es = fields_escape_state();
3285 tty->print("%s(%s) ", esc_names[(int)es], esc_names[(int)fields_es]);
3286 if (nt == PointsToNode::JavaObject && !this->scalar_replaceable())
3287 tty->print("NSR ");
3288 }
3289 if (is_Field()) {
3290 FieldNode* f = (FieldNode*)this;
3291 if (f->is_oop())
3292 tty->print("oop ");
3293 if (f->offset() > 0)
3294 tty->print("+%d ", f->offset());
3295 tty->print("(");
3296 for (BaseIterator i(f); i.has_next(); i.next()) {
3297 PointsToNode* b = i.get();
3298 tty->print(" %d%s", b->idx(),(b->is_JavaObject() ? "P" : ""));
3299 }
3300 tty->print(" )");
3301 }
3302 tty->print("[");
3303 for (EdgeIterator i(this); i.has_next(); i.next()) {
3304 PointsToNode* e = i.get();
3305 tty->print(" %d%s%s", e->idx(),(e->is_JavaObject() ? "P" : (e->is_Field() ? "F" : "")), e->is_Arraycopy() ? "cp" : "");
3306 }
3307 tty->print(" [");
3308 for (UseIterator i(this); i.has_next(); i.next()) {
3309 PointsToNode* u = i.get();
3310 bool is_base = false;
3311 if (PointsToNode::is_base_use(u)) {
3312 is_base = true;
3313 u = PointsToNode::get_use_node(u)->as_Field();
3314 }
3315 tty->print(" %d%s%s", u->idx(), is_base ? "b" : "", u->is_Arraycopy() ? "cp" : "");
3316 }
3317 tty->print(" ]] ");
3318 if (_node == NULL)
3319 tty->print_cr("<null>");
3320 else
3321 _node->dump();
3322 }
3323
3324 void ConnectionGraph::dump(GrowableArray<PointsToNode*>& ptnodes_worklist) {
3325 bool first = true;
3326 int ptnodes_length = ptnodes_worklist.length();
3327 for (int i = 0; i < ptnodes_length; i++) {
3328 PointsToNode *ptn = ptnodes_worklist.at(i);
3329 if (ptn == NULL || !ptn->is_JavaObject())
3330 continue;
3331 PointsToNode::EscapeState es = ptn->escape_state();
3332 if ((es != PointsToNode::NoEscape) && !Verbose) {
3333 continue;
3334 }
3335 Node* n = ptn->ideal_node();
3336 if (n->is_Allocate() || (n->is_CallStaticJava() &&
3337 n->as_CallStaticJava()->is_boxing_method())) {
3338 if (first) {
3339 tty->cr();
3340 tty->print("======== Connection graph for ");
3341 _compile->method()->print_short_name();
3342 tty->cr();
3343 first = false;
3344 }
3345 ptn->dump();
3346 // Print all locals and fields which reference this allocation
3347 for (UseIterator j(ptn); j.has_next(); j.next()) {
3348 PointsToNode* use = j.get();
3349 if (use->is_LocalVar()) {
3350 use->dump(Verbose);
3351 } else if (Verbose) {
3352 use->dump();
3353 }
3354 }
3355 tty->cr();
3356 }
3357 }
3358 }
3359 #endif