Tue, 09 Oct 2012 12:40:05 -0700
7199654: Remove LoadUI2LNode
Summary: Removed LoadUI2L node from Ideal nodes, use match rule in .ad files instead.
Reviewed-by: kvn
1 /*
2 * Copyright (c) 2005, 2012, 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 */
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/rootnode.hpp"
38 ConnectionGraph::ConnectionGraph(Compile * C, PhaseIterGVN *igvn) :
39 _nodes(C->comp_arena(), C->unique(), C->unique(), NULL),
40 _collecting(true),
41 _verify(false),
42 _compile(C),
43 _igvn(igvn),
44 _node_map(C->comp_arena()) {
45 // Add unknown java object.
46 add_java_object(C->top(), PointsToNode::GlobalEscape);
47 phantom_obj = ptnode_adr(C->top()->_idx)->as_JavaObject();
48 // Add ConP(#NULL) and ConN(#NULL) nodes.
49 Node* oop_null = igvn->zerocon(T_OBJECT);
50 assert(oop_null->_idx < nodes_size(), "should be created already");
51 add_java_object(oop_null, PointsToNode::NoEscape);
52 null_obj = ptnode_adr(oop_null->_idx)->as_JavaObject();
53 if (UseCompressedOops) {
54 Node* noop_null = igvn->zerocon(T_NARROWOOP);
55 assert(noop_null->_idx < nodes_size(), "should be created already");
56 map_ideal_node(noop_null, null_obj);
57 }
58 _pcmp_neq = NULL; // Should be initialized
59 _pcmp_eq = NULL;
60 }
62 bool ConnectionGraph::has_candidates(Compile *C) {
63 // EA brings benefits only when the code has allocations and/or locks which
64 // are represented by ideal Macro nodes.
65 int cnt = C->macro_count();
66 for( int i=0; i < cnt; i++ ) {
67 Node *n = C->macro_node(i);
68 if ( n->is_Allocate() )
69 return true;
70 if( n->is_Lock() ) {
71 Node* obj = n->as_Lock()->obj_node()->uncast();
72 if( !(obj->is_Parm() || obj->is_Con()) )
73 return true;
74 }
75 }
76 return false;
77 }
79 void ConnectionGraph::do_analysis(Compile *C, PhaseIterGVN *igvn) {
80 Compile::TracePhase t2("escapeAnalysis", &Phase::_t_escapeAnalysis, true);
81 ResourceMark rm;
83 // Add ConP#NULL and ConN#NULL nodes before ConnectionGraph construction
84 // to create space for them in ConnectionGraph::_nodes[].
85 Node* oop_null = igvn->zerocon(T_OBJECT);
86 Node* noop_null = igvn->zerocon(T_NARROWOOP);
87 ConnectionGraph* congraph = new(C->comp_arena()) ConnectionGraph(C, igvn);
88 // Perform escape analysis
89 if (congraph->compute_escape()) {
90 // There are non escaping objects.
91 C->set_congraph(congraph);
92 }
93 // Cleanup.
94 if (oop_null->outcnt() == 0)
95 igvn->hash_delete(oop_null);
96 if (noop_null->outcnt() == 0)
97 igvn->hash_delete(noop_null);
98 }
100 bool ConnectionGraph::compute_escape() {
101 Compile* C = _compile;
102 PhaseGVN* igvn = _igvn;
104 // Worklists used by EA.
105 Unique_Node_List delayed_worklist;
106 GrowableArray<Node*> alloc_worklist;
107 GrowableArray<Node*> ptr_cmp_worklist;
108 GrowableArray<Node*> storestore_worklist;
109 GrowableArray<PointsToNode*> ptnodes_worklist;
110 GrowableArray<JavaObjectNode*> java_objects_worklist;
111 GrowableArray<JavaObjectNode*> non_escaped_worklist;
112 GrowableArray<FieldNode*> oop_fields_worklist;
113 DEBUG_ONLY( GrowableArray<Node*> addp_worklist; )
115 { Compile::TracePhase t3("connectionGraph", &Phase::_t_connectionGraph, true);
117 // 1. Populate Connection Graph (CG) with PointsTo nodes.
118 ideal_nodes.map(C->unique(), NULL); // preallocate space
119 // Initialize worklist
120 if (C->root() != NULL) {
121 ideal_nodes.push(C->root());
122 }
123 for( uint next = 0; next < ideal_nodes.size(); ++next ) {
124 Node* n = ideal_nodes.at(next);
125 // Create PointsTo nodes and add them to Connection Graph. Called
126 // only once per ideal node since ideal_nodes is Unique_Node list.
127 add_node_to_connection_graph(n, &delayed_worklist);
128 PointsToNode* ptn = ptnode_adr(n->_idx);
129 if (ptn != NULL) {
130 ptnodes_worklist.append(ptn);
131 if (ptn->is_JavaObject()) {
132 java_objects_worklist.append(ptn->as_JavaObject());
133 if ((n->is_Allocate() || n->is_CallStaticJava()) &&
134 (ptn->escape_state() < PointsToNode::GlobalEscape)) {
135 // Only allocations and java static calls results are interesting.
136 non_escaped_worklist.append(ptn->as_JavaObject());
137 }
138 } else if (ptn->is_Field() && ptn->as_Field()->is_oop()) {
139 oop_fields_worklist.append(ptn->as_Field());
140 }
141 }
142 if (n->is_MergeMem()) {
143 // Collect all MergeMem nodes to add memory slices for
144 // scalar replaceable objects in split_unique_types().
145 _mergemem_worklist.append(n->as_MergeMem());
146 } else if (OptimizePtrCompare && n->is_Cmp() &&
147 (n->Opcode() == Op_CmpP || n->Opcode() == Op_CmpN)) {
148 // Collect compare pointers nodes.
149 ptr_cmp_worklist.append(n);
150 } else if (n->is_MemBarStoreStore()) {
151 // Collect all MemBarStoreStore nodes so that depending on the
152 // escape status of the associated Allocate node some of them
153 // may be eliminated.
154 storestore_worklist.append(n);
155 #ifdef ASSERT
156 } else if(n->is_AddP()) {
157 // Collect address nodes for graph verification.
158 addp_worklist.append(n);
159 #endif
160 }
161 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
162 Node* m = n->fast_out(i); // Get user
163 ideal_nodes.push(m);
164 }
165 }
166 if (non_escaped_worklist.length() == 0) {
167 _collecting = false;
168 return false; // Nothing to do.
169 }
170 // Add final simple edges to graph.
171 while(delayed_worklist.size() > 0) {
172 Node* n = delayed_worklist.pop();
173 add_final_edges(n);
174 }
175 int ptnodes_length = ptnodes_worklist.length();
177 #ifdef ASSERT
178 if (VerifyConnectionGraph) {
179 // Verify that no new simple edges could be created and all
180 // local vars has edges.
181 _verify = true;
182 for (int next = 0; next < ptnodes_length; ++next) {
183 PointsToNode* ptn = ptnodes_worklist.at(next);
184 add_final_edges(ptn->ideal_node());
185 if (ptn->is_LocalVar() && ptn->edge_count() == 0) {
186 ptn->dump();
187 assert(ptn->as_LocalVar()->edge_count() > 0, "sanity");
188 }
189 }
190 _verify = false;
191 }
192 #endif
194 // 2. Finish Graph construction by propagating references to all
195 // java objects through graph.
196 if (!complete_connection_graph(ptnodes_worklist, non_escaped_worklist,
197 java_objects_worklist, oop_fields_worklist)) {
198 // All objects escaped or hit time or iterations limits.
199 _collecting = false;
200 return false;
201 }
203 // 3. Adjust scalar_replaceable state of nonescaping objects and push
204 // scalar replaceable allocations on alloc_worklist for processing
205 // in split_unique_types().
206 int non_escaped_length = non_escaped_worklist.length();
207 for (int next = 0; next < non_escaped_length; next++) {
208 JavaObjectNode* ptn = non_escaped_worklist.at(next);
209 if (ptn->escape_state() == PointsToNode::NoEscape &&
210 ptn->scalar_replaceable()) {
211 adjust_scalar_replaceable_state(ptn);
212 if (ptn->scalar_replaceable()) {
213 alloc_worklist.append(ptn->ideal_node());
214 }
215 }
216 }
218 #ifdef ASSERT
219 if (VerifyConnectionGraph) {
220 // Verify that graph is complete - no new edges could be added or needed.
221 verify_connection_graph(ptnodes_worklist, non_escaped_worklist,
222 java_objects_worklist, addp_worklist);
223 }
224 assert(C->unique() == nodes_size(), "no new ideal nodes should be added during ConnectionGraph build");
225 assert(null_obj->escape_state() == PointsToNode::NoEscape &&
226 null_obj->edge_count() == 0 &&
227 !null_obj->arraycopy_src() &&
228 !null_obj->arraycopy_dst(), "sanity");
229 #endif
231 _collecting = false;
233 } // TracePhase t3("connectionGraph")
235 // 4. Optimize ideal graph based on EA information.
236 bool has_non_escaping_obj = (non_escaped_worklist.length() > 0);
237 if (has_non_escaping_obj) {
238 optimize_ideal_graph(ptr_cmp_worklist, storestore_worklist);
239 }
241 #ifndef PRODUCT
242 if (PrintEscapeAnalysis) {
243 dump(ptnodes_worklist); // Dump ConnectionGraph
244 }
245 #endif
247 bool has_scalar_replaceable_candidates = (alloc_worklist.length() > 0);
248 #ifdef ASSERT
249 if (VerifyConnectionGraph) {
250 int alloc_length = alloc_worklist.length();
251 for (int next = 0; next < alloc_length; ++next) {
252 Node* n = alloc_worklist.at(next);
253 PointsToNode* ptn = ptnode_adr(n->_idx);
254 assert(ptn->escape_state() == PointsToNode::NoEscape && ptn->scalar_replaceable(), "sanity");
255 }
256 }
257 #endif
259 // 5. Separate memory graph for scalar replaceable allcations.
260 if (has_scalar_replaceable_candidates &&
261 C->AliasLevel() >= 3 && EliminateAllocations) {
262 // Now use the escape information to create unique types for
263 // scalar replaceable objects.
264 split_unique_types(alloc_worklist);
265 if (C->failing()) return false;
266 C->print_method("After Escape Analysis", 2);
268 #ifdef ASSERT
269 } else if (Verbose && (PrintEscapeAnalysis || PrintEliminateAllocations)) {
270 tty->print("=== No allocations eliminated for ");
271 C->method()->print_short_name();
272 if(!EliminateAllocations) {
273 tty->print(" since EliminateAllocations is off ===");
274 } else if(!has_scalar_replaceable_candidates) {
275 tty->print(" since there are no scalar replaceable candidates ===");
276 } else if(C->AliasLevel() < 3) {
277 tty->print(" since AliasLevel < 3 ===");
278 }
279 tty->cr();
280 #endif
281 }
282 return has_non_escaping_obj;
283 }
285 // Utility function for nodes that load an object
286 void ConnectionGraph::add_objload_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
287 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
288 // ThreadLocal has RawPtr type.
289 const Type* t = _igvn->type(n);
290 if (t->make_ptr() != NULL) {
291 Node* adr = n->in(MemNode::Address);
292 #ifdef ASSERT
293 if (!adr->is_AddP()) {
294 assert(_igvn->type(adr)->isa_rawptr(), "sanity");
295 } else {
296 assert((ptnode_adr(adr->_idx) == NULL ||
297 ptnode_adr(adr->_idx)->as_Field()->is_oop()), "sanity");
298 }
299 #endif
300 add_local_var_and_edge(n, PointsToNode::NoEscape,
301 adr, delayed_worklist);
302 }
303 }
305 // Populate Connection Graph with PointsTo nodes and create simple
306 // connection graph edges.
307 void ConnectionGraph::add_node_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
308 assert(!_verify, "this method sould not be called for verification");
309 PhaseGVN* igvn = _igvn;
310 uint n_idx = n->_idx;
311 PointsToNode* n_ptn = ptnode_adr(n_idx);
312 if (n_ptn != NULL)
313 return; // No need to redefine PointsTo node during first iteration.
315 if (n->is_Call()) {
316 // Arguments to allocation and locking don't escape.
317 if (n->is_AbstractLock()) {
318 // Put Lock and Unlock nodes on IGVN worklist to process them during
319 // first IGVN optimization when escape information is still available.
320 record_for_optimizer(n);
321 } else if (n->is_Allocate()) {
322 add_call_node(n->as_Call());
323 record_for_optimizer(n);
324 } else {
325 if (n->is_CallStaticJava()) {
326 const char* name = n->as_CallStaticJava()->_name;
327 if (name != NULL && strcmp(name, "uncommon_trap") == 0)
328 return; // Skip uncommon traps
329 }
330 // Don't mark as processed since call's arguments have to be processed.
331 delayed_worklist->push(n);
332 // Check if a call returns an object.
333 if (n->as_Call()->returns_pointer() &&
334 n->as_Call()->proj_out(TypeFunc::Parms) != NULL) {
335 add_call_node(n->as_Call());
336 }
337 }
338 return;
339 }
340 // Put this check here to process call arguments since some call nodes
341 // point to phantom_obj.
342 if (n_ptn == phantom_obj || n_ptn == null_obj)
343 return; // Skip predefined nodes.
345 int opcode = n->Opcode();
346 switch (opcode) {
347 case Op_AddP: {
348 Node* base = get_addp_base(n);
349 PointsToNode* ptn_base = ptnode_adr(base->_idx);
350 // Field nodes are created for all field types. They are used in
351 // adjust_scalar_replaceable_state() and split_unique_types().
352 // Note, non-oop fields will have only base edges in Connection
353 // Graph because such fields are not used for oop loads and stores.
354 int offset = address_offset(n, igvn);
355 add_field(n, PointsToNode::NoEscape, offset);
356 if (ptn_base == NULL) {
357 delayed_worklist->push(n); // Process it later.
358 } else {
359 n_ptn = ptnode_adr(n_idx);
360 add_base(n_ptn->as_Field(), ptn_base);
361 }
362 break;
363 }
364 case Op_CastX2P: {
365 map_ideal_node(n, phantom_obj);
366 break;
367 }
368 case Op_CastPP:
369 case Op_CheckCastPP:
370 case Op_EncodeP:
371 case Op_DecodeN:
372 case Op_EncodePKlass:
373 case Op_DecodeNKlass: {
374 add_local_var_and_edge(n, PointsToNode::NoEscape,
375 n->in(1), delayed_worklist);
376 break;
377 }
378 case Op_CMoveP: {
379 add_local_var(n, PointsToNode::NoEscape);
380 // Do not add edges during first iteration because some could be
381 // not defined yet.
382 delayed_worklist->push(n);
383 break;
384 }
385 case Op_ConP:
386 case Op_ConN:
387 case Op_ConNKlass: {
388 // assume all oop constants globally escape except for null
389 PointsToNode::EscapeState es;
390 if (igvn->type(n) == TypePtr::NULL_PTR ||
391 igvn->type(n) == TypeNarrowOop::NULL_PTR) {
392 es = PointsToNode::NoEscape;
393 } else {
394 es = PointsToNode::GlobalEscape;
395 }
396 add_java_object(n, es);
397 break;
398 }
399 case Op_CreateEx: {
400 // assume that all exception objects globally escape
401 add_java_object(n, PointsToNode::GlobalEscape);
402 break;
403 }
404 case Op_LoadKlass:
405 case Op_LoadNKlass: {
406 // Unknown class is loaded
407 map_ideal_node(n, phantom_obj);
408 break;
409 }
410 case Op_LoadP:
411 case Op_LoadN:
412 case Op_LoadPLocked: {
413 add_objload_to_connection_graph(n, delayed_worklist);
414 break;
415 }
416 case Op_Parm: {
417 map_ideal_node(n, phantom_obj);
418 break;
419 }
420 case Op_PartialSubtypeCheck: {
421 // Produces Null or notNull and is used in only in CmpP so
422 // phantom_obj could be used.
423 map_ideal_node(n, phantom_obj); // Result is unknown
424 break;
425 }
426 case Op_Phi: {
427 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
428 // ThreadLocal has RawPtr type.
429 const Type* t = n->as_Phi()->type();
430 if (t->make_ptr() != NULL) {
431 add_local_var(n, PointsToNode::NoEscape);
432 // Do not add edges during first iteration because some could be
433 // not defined yet.
434 delayed_worklist->push(n);
435 }
436 break;
437 }
438 case Op_Proj: {
439 // we are only interested in the oop result projection from a call
440 if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
441 n->in(0)->as_Call()->returns_pointer()) {
442 add_local_var_and_edge(n, PointsToNode::NoEscape,
443 n->in(0), delayed_worklist);
444 }
445 break;
446 }
447 case Op_Rethrow: // Exception object escapes
448 case Op_Return: {
449 if (n->req() > TypeFunc::Parms &&
450 igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
451 // Treat Return value as LocalVar with GlobalEscape escape state.
452 add_local_var_and_edge(n, PointsToNode::GlobalEscape,
453 n->in(TypeFunc::Parms), delayed_worklist);
454 }
455 break;
456 }
457 case Op_GetAndSetP:
458 case Op_GetAndSetN: {
459 add_objload_to_connection_graph(n, delayed_worklist);
460 // fallthrough
461 }
462 case Op_StoreP:
463 case Op_StoreN:
464 case Op_StoreNKlass:
465 case Op_StorePConditional:
466 case Op_CompareAndSwapP:
467 case Op_CompareAndSwapN: {
468 Node* adr = n->in(MemNode::Address);
469 const Type *adr_type = igvn->type(adr);
470 adr_type = adr_type->make_ptr();
471 if (adr_type->isa_oopptr() ||
472 (opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass) &&
473 (adr_type == TypeRawPtr::NOTNULL &&
474 adr->in(AddPNode::Address)->is_Proj() &&
475 adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
476 delayed_worklist->push(n); // Process it later.
477 #ifdef ASSERT
478 assert(adr->is_AddP(), "expecting an AddP");
479 if (adr_type == TypeRawPtr::NOTNULL) {
480 // Verify a raw address for a store captured by Initialize node.
481 int offs = (int)igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
482 assert(offs != Type::OffsetBot, "offset must be a constant");
483 }
484 #endif
485 } else {
486 // Ignore copy the displaced header to the BoxNode (OSR compilation).
487 if (adr->is_BoxLock())
488 break;
489 // Stored value escapes in unsafe access.
490 if ((opcode == Op_StoreP) && (adr_type == TypeRawPtr::BOTTOM)) {
491 // Pointer stores in G1 barriers looks like unsafe access.
492 // Ignore such stores to be able scalar replace non-escaping
493 // allocations.
494 if (UseG1GC && adr->is_AddP()) {
495 Node* base = get_addp_base(adr);
496 if (base->Opcode() == Op_LoadP &&
497 base->in(MemNode::Address)->is_AddP()) {
498 adr = base->in(MemNode::Address);
499 Node* tls = get_addp_base(adr);
500 if (tls->Opcode() == Op_ThreadLocal) {
501 int offs = (int)igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
502 if (offs == in_bytes(JavaThread::satb_mark_queue_offset() +
503 PtrQueue::byte_offset_of_buf())) {
504 break; // G1 pre barier previous oop value store.
505 }
506 if (offs == in_bytes(JavaThread::dirty_card_queue_offset() +
507 PtrQueue::byte_offset_of_buf())) {
508 break; // G1 post barier card address store.
509 }
510 }
511 }
512 }
513 delayed_worklist->push(n); // Process unsafe access later.
514 break;
515 }
516 #ifdef ASSERT
517 n->dump(1);
518 assert(false, "not unsafe or G1 barrier raw StoreP");
519 #endif
520 }
521 break;
522 }
523 case Op_AryEq:
524 case Op_StrComp:
525 case Op_StrEquals:
526 case Op_StrIndexOf: {
527 add_local_var(n, PointsToNode::ArgEscape);
528 delayed_worklist->push(n); // Process it later.
529 break;
530 }
531 case Op_ThreadLocal: {
532 add_java_object(n, PointsToNode::ArgEscape);
533 break;
534 }
535 default:
536 ; // Do nothing for nodes not related to EA.
537 }
538 return;
539 }
541 #ifdef ASSERT
542 #define ELSE_FAIL(name) \
543 /* Should not be called for not pointer type. */ \
544 n->dump(1); \
545 assert(false, name); \
546 break;
547 #else
548 #define ELSE_FAIL(name) \
549 break;
550 #endif
552 // Add final simple edges to graph.
553 void ConnectionGraph::add_final_edges(Node *n) {
554 PointsToNode* n_ptn = ptnode_adr(n->_idx);
555 #ifdef ASSERT
556 if (_verify && n_ptn->is_JavaObject())
557 return; // This method does not change graph for JavaObject.
558 #endif
560 if (n->is_Call()) {
561 process_call_arguments(n->as_Call());
562 return;
563 }
564 assert(n->is_Store() || n->is_LoadStore() ||
565 (n_ptn != NULL) && (n_ptn->ideal_node() != NULL),
566 "node should be registered already");
567 int opcode = n->Opcode();
568 switch (opcode) {
569 case Op_AddP: {
570 Node* base = get_addp_base(n);
571 PointsToNode* ptn_base = ptnode_adr(base->_idx);
572 assert(ptn_base != NULL, "field's base should be registered");
573 add_base(n_ptn->as_Field(), ptn_base);
574 break;
575 }
576 case Op_CastPP:
577 case Op_CheckCastPP:
578 case Op_EncodeP:
579 case Op_DecodeN:
580 case Op_EncodePKlass:
581 case Op_DecodeNKlass: {
582 add_local_var_and_edge(n, PointsToNode::NoEscape,
583 n->in(1), NULL);
584 break;
585 }
586 case Op_CMoveP: {
587 for (uint i = CMoveNode::IfFalse; i < n->req(); i++) {
588 Node* in = n->in(i);
589 if (in == NULL)
590 continue; // ignore NULL
591 Node* uncast_in = in->uncast();
592 if (uncast_in->is_top() || uncast_in == n)
593 continue; // ignore top or inputs which go back this node
594 PointsToNode* ptn = ptnode_adr(in->_idx);
595 assert(ptn != NULL, "node should be registered");
596 add_edge(n_ptn, ptn);
597 }
598 break;
599 }
600 case Op_LoadP:
601 case Op_LoadN:
602 case Op_LoadPLocked: {
603 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
604 // ThreadLocal has RawPtr type.
605 const Type* t = _igvn->type(n);
606 if (t->make_ptr() != NULL) {
607 Node* adr = n->in(MemNode::Address);
608 add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
609 break;
610 }
611 ELSE_FAIL("Op_LoadP");
612 }
613 case Op_Phi: {
614 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
615 // ThreadLocal has RawPtr type.
616 const Type* t = n->as_Phi()->type();
617 if (t->make_ptr() != NULL) {
618 for (uint i = 1; i < n->req(); i++) {
619 Node* in = n->in(i);
620 if (in == NULL)
621 continue; // ignore NULL
622 Node* uncast_in = in->uncast();
623 if (uncast_in->is_top() || uncast_in == n)
624 continue; // ignore top or inputs which go back this node
625 PointsToNode* ptn = ptnode_adr(in->_idx);
626 assert(ptn != NULL, "node should be registered");
627 add_edge(n_ptn, ptn);
628 }
629 break;
630 }
631 ELSE_FAIL("Op_Phi");
632 }
633 case Op_Proj: {
634 // we are only interested in the oop result projection from a call
635 if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
636 n->in(0)->as_Call()->returns_pointer()) {
637 add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(0), NULL);
638 break;
639 }
640 ELSE_FAIL("Op_Proj");
641 }
642 case Op_Rethrow: // Exception object escapes
643 case Op_Return: {
644 if (n->req() > TypeFunc::Parms &&
645 _igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
646 // Treat Return value as LocalVar with GlobalEscape escape state.
647 add_local_var_and_edge(n, PointsToNode::GlobalEscape,
648 n->in(TypeFunc::Parms), NULL);
649 break;
650 }
651 ELSE_FAIL("Op_Return");
652 }
653 case Op_StoreP:
654 case Op_StoreN:
655 case Op_StoreNKlass:
656 case Op_StorePConditional:
657 case Op_CompareAndSwapP:
658 case Op_CompareAndSwapN:
659 case Op_GetAndSetP:
660 case Op_GetAndSetN: {
661 Node* adr = n->in(MemNode::Address);
662 if (opcode == Op_GetAndSetP || opcode == Op_GetAndSetN) {
663 const Type* t = _igvn->type(n);
664 if (t->make_ptr() != NULL) {
665 add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
666 }
667 }
668 const Type *adr_type = _igvn->type(adr);
669 adr_type = adr_type->make_ptr();
670 if (adr_type->isa_oopptr() ||
671 (opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass) &&
672 (adr_type == TypeRawPtr::NOTNULL &&
673 adr->in(AddPNode::Address)->is_Proj() &&
674 adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
675 // Point Address to Value
676 PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
677 assert(adr_ptn != NULL &&
678 adr_ptn->as_Field()->is_oop(), "node should be registered");
679 Node *val = n->in(MemNode::ValueIn);
680 PointsToNode* ptn = ptnode_adr(val->_idx);
681 assert(ptn != NULL, "node should be registered");
682 add_edge(adr_ptn, ptn);
683 break;
684 } else if ((opcode == Op_StoreP) && (adr_type == TypeRawPtr::BOTTOM)) {
685 // Stored value escapes in unsafe access.
686 Node *val = n->in(MemNode::ValueIn);
687 PointsToNode* ptn = ptnode_adr(val->_idx);
688 assert(ptn != NULL, "node should be registered");
689 ptn->set_escape_state(PointsToNode::GlobalEscape);
690 // Add edge to object for unsafe access with offset.
691 PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
692 assert(adr_ptn != NULL, "node should be registered");
693 if (adr_ptn->is_Field()) {
694 assert(adr_ptn->as_Field()->is_oop(), "should be oop field");
695 add_edge(adr_ptn, ptn);
696 }
697 break;
698 }
699 ELSE_FAIL("Op_StoreP");
700 }
701 case Op_AryEq:
702 case Op_StrComp:
703 case Op_StrEquals:
704 case Op_StrIndexOf: {
705 // char[] arrays passed to string intrinsic do not escape but
706 // they are not scalar replaceable. Adjust escape state for them.
707 // Start from in(2) edge since in(1) is memory edge.
708 for (uint i = 2; i < n->req(); i++) {
709 Node* adr = n->in(i);
710 const Type* at = _igvn->type(adr);
711 if (!adr->is_top() && at->isa_ptr()) {
712 assert(at == Type::TOP || at == TypePtr::NULL_PTR ||
713 at->isa_ptr() != NULL, "expecting a pointer");
714 if (adr->is_AddP()) {
715 adr = get_addp_base(adr);
716 }
717 PointsToNode* ptn = ptnode_adr(adr->_idx);
718 assert(ptn != NULL, "node should be registered");
719 add_edge(n_ptn, ptn);
720 }
721 }
722 break;
723 }
724 default: {
725 // This method should be called only for EA specific nodes which may
726 // miss some edges when they were created.
727 #ifdef ASSERT
728 n->dump(1);
729 #endif
730 guarantee(false, "unknown node");
731 }
732 }
733 return;
734 }
736 void ConnectionGraph::add_call_node(CallNode* call) {
737 assert(call->returns_pointer(), "only for call which returns pointer");
738 uint call_idx = call->_idx;
739 if (call->is_Allocate()) {
740 Node* k = call->in(AllocateNode::KlassNode);
741 const TypeKlassPtr* kt = k->bottom_type()->isa_klassptr();
742 assert(kt != NULL, "TypeKlassPtr required.");
743 ciKlass* cik = kt->klass();
744 PointsToNode::EscapeState es = PointsToNode::NoEscape;
745 bool scalar_replaceable = true;
746 if (call->is_AllocateArray()) {
747 if (!cik->is_array_klass()) { // StressReflectiveCode
748 es = PointsToNode::GlobalEscape;
749 } else {
750 int length = call->in(AllocateNode::ALength)->find_int_con(-1);
751 if (length < 0 || length > EliminateAllocationArraySizeLimit) {
752 // Not scalar replaceable if the length is not constant or too big.
753 scalar_replaceable = false;
754 }
755 }
756 } else { // Allocate instance
757 if (cik->is_subclass_of(_compile->env()->Thread_klass()) ||
758 !cik->is_instance_klass() || // StressReflectiveCode
759 cik->as_instance_klass()->has_finalizer()) {
760 es = PointsToNode::GlobalEscape;
761 }
762 }
763 add_java_object(call, es);
764 PointsToNode* ptn = ptnode_adr(call_idx);
765 if (!scalar_replaceable && ptn->scalar_replaceable()) {
766 ptn->set_scalar_replaceable(false);
767 }
768 } else if (call->is_CallStaticJava()) {
769 // Call nodes could be different types:
770 //
771 // 1. CallDynamicJavaNode (what happened during call is unknown):
772 //
773 // - mapped to GlobalEscape JavaObject node if oop is returned;
774 //
775 // - all oop arguments are escaping globally;
776 //
777 // 2. CallStaticJavaNode (execute bytecode analysis if possible):
778 //
779 // - the same as CallDynamicJavaNode if can't do bytecode analysis;
780 //
781 // - mapped to GlobalEscape JavaObject node if unknown oop is returned;
782 // - mapped to NoEscape JavaObject node if non-escaping object allocated
783 // during call is returned;
784 // - mapped to ArgEscape LocalVar node pointed to object arguments
785 // which are returned and does not escape during call;
786 //
787 // - oop arguments escaping status is defined by bytecode analysis;
788 //
789 // For a static call, we know exactly what method is being called.
790 // Use bytecode estimator to record whether the call's return value escapes.
791 ciMethod* meth = call->as_CallJava()->method();
792 if (meth == NULL) {
793 const char* name = call->as_CallStaticJava()->_name;
794 assert(strncmp(name, "_multianewarray", 15) == 0, "TODO: add failed case check");
795 // Returns a newly allocated unescaped object.
796 add_java_object(call, PointsToNode::NoEscape);
797 ptnode_adr(call_idx)->set_scalar_replaceable(false);
798 } else {
799 BCEscapeAnalyzer* call_analyzer = meth->get_bcea();
800 call_analyzer->copy_dependencies(_compile->dependencies());
801 if (call_analyzer->is_return_allocated()) {
802 // Returns a newly allocated unescaped object, simply
803 // update dependency information.
804 // Mark it as NoEscape so that objects referenced by
805 // it's fields will be marked as NoEscape at least.
806 add_java_object(call, PointsToNode::NoEscape);
807 ptnode_adr(call_idx)->set_scalar_replaceable(false);
808 } else {
809 // Determine whether any arguments are returned.
810 const TypeTuple* d = call->tf()->domain();
811 bool ret_arg = false;
812 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
813 if (d->field_at(i)->isa_ptr() != NULL &&
814 call_analyzer->is_arg_returned(i - TypeFunc::Parms)) {
815 ret_arg = true;
816 break;
817 }
818 }
819 if (ret_arg) {
820 add_local_var(call, PointsToNode::ArgEscape);
821 } else {
822 // Returns unknown object.
823 map_ideal_node(call, phantom_obj);
824 }
825 }
826 }
827 } else {
828 // An other type of call, assume the worst case:
829 // returned value is unknown and globally escapes.
830 assert(call->Opcode() == Op_CallDynamicJava, "add failed case check");
831 map_ideal_node(call, phantom_obj);
832 }
833 }
835 void ConnectionGraph::process_call_arguments(CallNode *call) {
836 bool is_arraycopy = false;
837 switch (call->Opcode()) {
838 #ifdef ASSERT
839 case Op_Allocate:
840 case Op_AllocateArray:
841 case Op_Lock:
842 case Op_Unlock:
843 assert(false, "should be done already");
844 break;
845 #endif
846 case Op_CallLeafNoFP:
847 is_arraycopy = (call->as_CallLeaf()->_name != NULL &&
848 strstr(call->as_CallLeaf()->_name, "arraycopy") != 0);
849 // fall through
850 case Op_CallLeaf: {
851 // Stub calls, objects do not escape but they are not scale replaceable.
852 // Adjust escape state for outgoing arguments.
853 const TypeTuple * d = call->tf()->domain();
854 bool src_has_oops = false;
855 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
856 const Type* at = d->field_at(i);
857 Node *arg = call->in(i);
858 const Type *aat = _igvn->type(arg);
859 if (arg->is_top() || !at->isa_ptr() || !aat->isa_ptr())
860 continue;
861 if (arg->is_AddP()) {
862 //
863 // The inline_native_clone() case when the arraycopy stub is called
864 // after the allocation before Initialize and CheckCastPP nodes.
865 // Or normal arraycopy for object arrays case.
866 //
867 // Set AddP's base (Allocate) as not scalar replaceable since
868 // pointer to the base (with offset) is passed as argument.
869 //
870 arg = get_addp_base(arg);
871 }
872 PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
873 assert(arg_ptn != NULL, "should be registered");
874 PointsToNode::EscapeState arg_esc = arg_ptn->escape_state();
875 if (is_arraycopy || arg_esc < PointsToNode::ArgEscape) {
876 assert(aat == Type::TOP || aat == TypePtr::NULL_PTR ||
877 aat->isa_ptr() != NULL, "expecting an Ptr");
878 bool arg_has_oops = aat->isa_oopptr() &&
879 (aat->isa_oopptr()->klass() == NULL || aat->isa_instptr() ||
880 (aat->isa_aryptr() && aat->isa_aryptr()->klass()->is_obj_array_klass()));
881 if (i == TypeFunc::Parms) {
882 src_has_oops = arg_has_oops;
883 }
884 //
885 // src or dst could be j.l.Object when other is basic type array:
886 //
887 // arraycopy(char[],0,Object*,0,size);
888 // arraycopy(Object*,0,char[],0,size);
889 //
890 // Don't add edges in such cases.
891 //
892 bool arg_is_arraycopy_dest = src_has_oops && is_arraycopy &&
893 arg_has_oops && (i > TypeFunc::Parms);
894 #ifdef ASSERT
895 if (!(is_arraycopy ||
896 call->as_CallLeaf()->_name != NULL &&
897 (strcmp(call->as_CallLeaf()->_name, "g1_wb_pre") == 0 ||
898 strcmp(call->as_CallLeaf()->_name, "g1_wb_post") == 0 ))
899 ) {
900 call->dump();
901 assert(false, "EA: unexpected CallLeaf");
902 }
903 #endif
904 // Always process arraycopy's destination object since
905 // we need to add all possible edges to references in
906 // source object.
907 if (arg_esc >= PointsToNode::ArgEscape &&
908 !arg_is_arraycopy_dest) {
909 continue;
910 }
911 set_escape_state(arg_ptn, PointsToNode::ArgEscape);
912 if (arg_is_arraycopy_dest) {
913 Node* src = call->in(TypeFunc::Parms);
914 if (src->is_AddP()) {
915 src = get_addp_base(src);
916 }
917 PointsToNode* src_ptn = ptnode_adr(src->_idx);
918 assert(src_ptn != NULL, "should be registered");
919 if (arg_ptn != src_ptn) {
920 // Special arraycopy edge:
921 // A destination object's field can't have the source object
922 // as base since objects escape states are not related.
923 // Only escape state of destination object's fields affects
924 // escape state of fields in source object.
925 add_arraycopy(call, PointsToNode::ArgEscape, src_ptn, arg_ptn);
926 }
927 }
928 }
929 }
930 break;
931 }
932 case Op_CallStaticJava: {
933 // For a static call, we know exactly what method is being called.
934 // Use bytecode estimator to record the call's escape affects
935 #ifdef ASSERT
936 const char* name = call->as_CallStaticJava()->_name;
937 assert((name == NULL || strcmp(name, "uncommon_trap") != 0), "normal calls only");
938 #endif
939 ciMethod* meth = call->as_CallJava()->method();
940 BCEscapeAnalyzer* call_analyzer = (meth !=NULL) ? meth->get_bcea() : NULL;
941 // fall-through if not a Java method or no analyzer information
942 if (call_analyzer != NULL) {
943 PointsToNode* call_ptn = ptnode_adr(call->_idx);
944 const TypeTuple* d = call->tf()->domain();
945 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
946 const Type* at = d->field_at(i);
947 int k = i - TypeFunc::Parms;
948 Node* arg = call->in(i);
949 PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
950 if (at->isa_ptr() != NULL &&
951 call_analyzer->is_arg_returned(k)) {
952 // The call returns arguments.
953 if (call_ptn != NULL) { // Is call's result used?
954 assert(call_ptn->is_LocalVar(), "node should be registered");
955 assert(arg_ptn != NULL, "node should be registered");
956 add_edge(call_ptn, arg_ptn);
957 }
958 }
959 if (at->isa_oopptr() != NULL &&
960 arg_ptn->escape_state() < PointsToNode::GlobalEscape) {
961 if (!call_analyzer->is_arg_stack(k)) {
962 // The argument global escapes
963 set_escape_state(arg_ptn, PointsToNode::GlobalEscape);
964 } else {
965 set_escape_state(arg_ptn, PointsToNode::ArgEscape);
966 if (!call_analyzer->is_arg_local(k)) {
967 // The argument itself doesn't escape, but any fields might
968 set_fields_escape_state(arg_ptn, PointsToNode::GlobalEscape);
969 }
970 }
971 }
972 }
973 if (call_ptn != NULL && call_ptn->is_LocalVar()) {
974 // The call returns arguments.
975 assert(call_ptn->edge_count() > 0, "sanity");
976 if (!call_analyzer->is_return_local()) {
977 // Returns also unknown object.
978 add_edge(call_ptn, phantom_obj);
979 }
980 }
981 break;
982 }
983 }
984 default: {
985 // Fall-through here if not a Java method or no analyzer information
986 // or some other type of call, assume the worst case: all arguments
987 // globally escape.
988 const TypeTuple* d = call->tf()->domain();
989 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
990 const Type* at = d->field_at(i);
991 if (at->isa_oopptr() != NULL) {
992 Node* arg = call->in(i);
993 if (arg->is_AddP()) {
994 arg = get_addp_base(arg);
995 }
996 assert(ptnode_adr(arg->_idx) != NULL, "should be defined already");
997 set_escape_state(ptnode_adr(arg->_idx), PointsToNode::GlobalEscape);
998 }
999 }
1000 }
1001 }
1002 }
1005 // Finish Graph construction.
1006 bool ConnectionGraph::complete_connection_graph(
1007 GrowableArray<PointsToNode*>& ptnodes_worklist,
1008 GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1009 GrowableArray<JavaObjectNode*>& java_objects_worklist,
1010 GrowableArray<FieldNode*>& oop_fields_worklist) {
1011 // Normally only 1-3 passes needed to build Connection Graph depending
1012 // on graph complexity. Observed 8 passes in jvm2008 compiler.compiler.
1013 // Set limit to 20 to catch situation when something did go wrong and
1014 // bailout Escape Analysis.
1015 // Also limit build time to 30 sec (60 in debug VM).
1016 #define CG_BUILD_ITER_LIMIT 20
1017 #ifdef ASSERT
1018 #define CG_BUILD_TIME_LIMIT 60.0
1019 #else
1020 #define CG_BUILD_TIME_LIMIT 30.0
1021 #endif
1023 // Propagate GlobalEscape and ArgEscape escape states and check that
1024 // we still have non-escaping objects. The method pushs on _worklist
1025 // Field nodes which reference phantom_object.
1026 if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1027 return false; // Nothing to do.
1028 }
1029 // Now propagate references to all JavaObject nodes.
1030 int java_objects_length = java_objects_worklist.length();
1031 elapsedTimer time;
1032 int new_edges = 1;
1033 int iterations = 0;
1034 do {
1035 while ((new_edges > 0) &&
1036 (iterations++ < CG_BUILD_ITER_LIMIT) &&
1037 (time.seconds() < CG_BUILD_TIME_LIMIT)) {
1038 time.start();
1039 new_edges = 0;
1040 // Propagate references to phantom_object for nodes pushed on _worklist
1041 // by find_non_escaped_objects() and find_field_value().
1042 new_edges += add_java_object_edges(phantom_obj, false);
1043 for (int next = 0; next < java_objects_length; ++next) {
1044 JavaObjectNode* ptn = java_objects_worklist.at(next);
1045 new_edges += add_java_object_edges(ptn, true);
1046 }
1047 if (new_edges > 0) {
1048 // Update escape states on each iteration if graph was updated.
1049 if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1050 return false; // Nothing to do.
1051 }
1052 }
1053 time.stop();
1054 }
1055 if ((iterations < CG_BUILD_ITER_LIMIT) &&
1056 (time.seconds() < CG_BUILD_TIME_LIMIT)) {
1057 time.start();
1058 // Find fields which have unknown value.
1059 int fields_length = oop_fields_worklist.length();
1060 for (int next = 0; next < fields_length; next++) {
1061 FieldNode* field = oop_fields_worklist.at(next);
1062 if (field->edge_count() == 0) {
1063 new_edges += find_field_value(field);
1064 // This code may added new edges to phantom_object.
1065 // Need an other cycle to propagate references to phantom_object.
1066 }
1067 }
1068 time.stop();
1069 } else {
1070 new_edges = 0; // Bailout
1071 }
1072 } while (new_edges > 0);
1074 // Bailout if passed limits.
1075 if ((iterations >= CG_BUILD_ITER_LIMIT) ||
1076 (time.seconds() >= CG_BUILD_TIME_LIMIT)) {
1077 Compile* C = _compile;
1078 if (C->log() != NULL) {
1079 C->log()->begin_elem("connectionGraph_bailout reason='reached ");
1080 C->log()->text("%s", (iterations >= CG_BUILD_ITER_LIMIT) ? "iterations" : "time");
1081 C->log()->end_elem(" limit'");
1082 }
1083 assert(false, err_msg_res("infinite EA connection graph build (%f sec, %d iterations) with %d nodes and worklist size %d",
1084 time.seconds(), iterations, nodes_size(), ptnodes_worklist.length()));
1085 // Possible infinite build_connection_graph loop,
1086 // bailout (no changes to ideal graph were made).
1087 return false;
1088 }
1089 #ifdef ASSERT
1090 if (Verbose && PrintEscapeAnalysis) {
1091 tty->print_cr("EA: %d iterations to build connection graph with %d nodes and worklist size %d",
1092 iterations, nodes_size(), ptnodes_worklist.length());
1093 }
1094 #endif
1096 #undef CG_BUILD_ITER_LIMIT
1097 #undef CG_BUILD_TIME_LIMIT
1099 // Find fields initialized by NULL for non-escaping Allocations.
1100 int non_escaped_length = non_escaped_worklist.length();
1101 for (int next = 0; next < non_escaped_length; next++) {
1102 JavaObjectNode* ptn = non_escaped_worklist.at(next);
1103 PointsToNode::EscapeState es = ptn->escape_state();
1104 assert(es <= PointsToNode::ArgEscape, "sanity");
1105 if (es == PointsToNode::NoEscape) {
1106 if (find_init_values(ptn, null_obj, _igvn) > 0) {
1107 // Adding references to NULL object does not change escape states
1108 // since it does not escape. Also no fields are added to NULL object.
1109 add_java_object_edges(null_obj, false);
1110 }
1111 }
1112 Node* n = ptn->ideal_node();
1113 if (n->is_Allocate()) {
1114 // The object allocated by this Allocate node will never be
1115 // seen by an other thread. Mark it so that when it is
1116 // expanded no MemBarStoreStore is added.
1117 InitializeNode* ini = n->as_Allocate()->initialization();
1118 if (ini != NULL)
1119 ini->set_does_not_escape();
1120 }
1121 }
1122 return true; // Finished graph construction.
1123 }
1125 // Propagate GlobalEscape and ArgEscape escape states to all nodes
1126 // and check that we still have non-escaping java objects.
1127 bool ConnectionGraph::find_non_escaped_objects(GrowableArray<PointsToNode*>& ptnodes_worklist,
1128 GrowableArray<JavaObjectNode*>& non_escaped_worklist) {
1129 GrowableArray<PointsToNode*> escape_worklist;
1130 // First, put all nodes with GlobalEscape and ArgEscape states on worklist.
1131 int ptnodes_length = ptnodes_worklist.length();
1132 for (int next = 0; next < ptnodes_length; ++next) {
1133 PointsToNode* ptn = ptnodes_worklist.at(next);
1134 if (ptn->escape_state() >= PointsToNode::ArgEscape ||
1135 ptn->fields_escape_state() >= PointsToNode::ArgEscape) {
1136 escape_worklist.push(ptn);
1137 }
1138 }
1139 // Set escape states to referenced nodes (edges list).
1140 while (escape_worklist.length() > 0) {
1141 PointsToNode* ptn = escape_worklist.pop();
1142 PointsToNode::EscapeState es = ptn->escape_state();
1143 PointsToNode::EscapeState field_es = ptn->fields_escape_state();
1144 if (ptn->is_Field() && ptn->as_Field()->is_oop() &&
1145 es >= PointsToNode::ArgEscape) {
1146 // GlobalEscape or ArgEscape state of field means it has unknown value.
1147 if (add_edge(ptn, phantom_obj)) {
1148 // New edge was added
1149 add_field_uses_to_worklist(ptn->as_Field());
1150 }
1151 }
1152 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1153 PointsToNode* e = i.get();
1154 if (e->is_Arraycopy()) {
1155 assert(ptn->arraycopy_dst(), "sanity");
1156 // Propagate only fields escape state through arraycopy edge.
1157 if (e->fields_escape_state() < field_es) {
1158 set_fields_escape_state(e, field_es);
1159 escape_worklist.push(e);
1160 }
1161 } else if (es >= field_es) {
1162 // fields_escape_state is also set to 'es' if it is less than 'es'.
1163 if (e->escape_state() < es) {
1164 set_escape_state(e, es);
1165 escape_worklist.push(e);
1166 }
1167 } else {
1168 // Propagate field escape state.
1169 bool es_changed = false;
1170 if (e->fields_escape_state() < field_es) {
1171 set_fields_escape_state(e, field_es);
1172 es_changed = true;
1173 }
1174 if ((e->escape_state() < field_es) &&
1175 e->is_Field() && ptn->is_JavaObject() &&
1176 e->as_Field()->is_oop()) {
1177 // Change escape state of referenced fileds.
1178 set_escape_state(e, field_es);
1179 es_changed = true;;
1180 } else if (e->escape_state() < es) {
1181 set_escape_state(e, es);
1182 es_changed = true;;
1183 }
1184 if (es_changed) {
1185 escape_worklist.push(e);
1186 }
1187 }
1188 }
1189 }
1190 // Remove escaped objects from non_escaped list.
1191 for (int next = non_escaped_worklist.length()-1; next >= 0 ; --next) {
1192 JavaObjectNode* ptn = non_escaped_worklist.at(next);
1193 if (ptn->escape_state() >= PointsToNode::GlobalEscape) {
1194 non_escaped_worklist.delete_at(next);
1195 }
1196 if (ptn->escape_state() == PointsToNode::NoEscape) {
1197 // Find fields in non-escaped allocations which have unknown value.
1198 find_init_values(ptn, phantom_obj, NULL);
1199 }
1200 }
1201 return (non_escaped_worklist.length() > 0);
1202 }
1204 // Add all references to JavaObject node by walking over all uses.
1205 int ConnectionGraph::add_java_object_edges(JavaObjectNode* jobj, bool populate_worklist) {
1206 int new_edges = 0;
1207 if (populate_worklist) {
1208 // Populate _worklist by uses of jobj's uses.
1209 for (UseIterator i(jobj); i.has_next(); i.next()) {
1210 PointsToNode* use = i.get();
1211 if (use->is_Arraycopy())
1212 continue;
1213 add_uses_to_worklist(use);
1214 if (use->is_Field() && use->as_Field()->is_oop()) {
1215 // Put on worklist all field's uses (loads) and
1216 // related field nodes (same base and offset).
1217 add_field_uses_to_worklist(use->as_Field());
1218 }
1219 }
1220 }
1221 while(_worklist.length() > 0) {
1222 PointsToNode* use = _worklist.pop();
1223 if (PointsToNode::is_base_use(use)) {
1224 // Add reference from jobj to field and from field to jobj (field's base).
1225 use = PointsToNode::get_use_node(use)->as_Field();
1226 if (add_base(use->as_Field(), jobj)) {
1227 new_edges++;
1228 }
1229 continue;
1230 }
1231 assert(!use->is_JavaObject(), "sanity");
1232 if (use->is_Arraycopy()) {
1233 if (jobj == null_obj) // NULL object does not have field edges
1234 continue;
1235 // Added edge from Arraycopy node to arraycopy's source java object
1236 if (add_edge(use, jobj)) {
1237 jobj->set_arraycopy_src();
1238 new_edges++;
1239 }
1240 // and stop here.
1241 continue;
1242 }
1243 if (!add_edge(use, jobj))
1244 continue; // No new edge added, there was such edge already.
1245 new_edges++;
1246 if (use->is_LocalVar()) {
1247 add_uses_to_worklist(use);
1248 if (use->arraycopy_dst()) {
1249 for (EdgeIterator i(use); i.has_next(); i.next()) {
1250 PointsToNode* e = i.get();
1251 if (e->is_Arraycopy()) {
1252 if (jobj == null_obj) // NULL object does not have field edges
1253 continue;
1254 // Add edge from arraycopy's destination java object to Arraycopy node.
1255 if (add_edge(jobj, e)) {
1256 new_edges++;
1257 jobj->set_arraycopy_dst();
1258 }
1259 }
1260 }
1261 }
1262 } else {
1263 // Added new edge to stored in field values.
1264 // Put on worklist all field's uses (loads) and
1265 // related field nodes (same base and offset).
1266 add_field_uses_to_worklist(use->as_Field());
1267 }
1268 }
1269 return new_edges;
1270 }
1272 // Put on worklist all related field nodes.
1273 void ConnectionGraph::add_field_uses_to_worklist(FieldNode* field) {
1274 assert(field->is_oop(), "sanity");
1275 int offset = field->offset();
1276 add_uses_to_worklist(field);
1277 // Loop over all bases of this field and push on worklist Field nodes
1278 // with the same offset and base (since they may reference the same field).
1279 for (BaseIterator i(field); i.has_next(); i.next()) {
1280 PointsToNode* base = i.get();
1281 add_fields_to_worklist(field, base);
1282 // Check if the base was source object of arraycopy and go over arraycopy's
1283 // destination objects since values stored to a field of source object are
1284 // accessable by uses (loads) of fields of destination objects.
1285 if (base->arraycopy_src()) {
1286 for (UseIterator j(base); j.has_next(); j.next()) {
1287 PointsToNode* arycp = j.get();
1288 if (arycp->is_Arraycopy()) {
1289 for (UseIterator k(arycp); k.has_next(); k.next()) {
1290 PointsToNode* abase = k.get();
1291 if (abase->arraycopy_dst() && abase != base) {
1292 // Look for the same arracopy reference.
1293 add_fields_to_worklist(field, abase);
1294 }
1295 }
1296 }
1297 }
1298 }
1299 }
1300 }
1302 // Put on worklist all related field nodes.
1303 void ConnectionGraph::add_fields_to_worklist(FieldNode* field, PointsToNode* base) {
1304 int offset = field->offset();
1305 if (base->is_LocalVar()) {
1306 for (UseIterator j(base); j.has_next(); j.next()) {
1307 PointsToNode* f = j.get();
1308 if (PointsToNode::is_base_use(f)) { // Field
1309 f = PointsToNode::get_use_node(f);
1310 if (f == field || !f->as_Field()->is_oop())
1311 continue;
1312 int offs = f->as_Field()->offset();
1313 if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1314 add_to_worklist(f);
1315 }
1316 }
1317 }
1318 } else {
1319 assert(base->is_JavaObject(), "sanity");
1320 if (// Skip phantom_object since it is only used to indicate that
1321 // this field's content globally escapes.
1322 (base != phantom_obj) &&
1323 // NULL object node does not have fields.
1324 (base != null_obj)) {
1325 for (EdgeIterator i(base); i.has_next(); i.next()) {
1326 PointsToNode* f = i.get();
1327 // Skip arraycopy edge since store to destination object field
1328 // does not update value in source object field.
1329 if (f->is_Arraycopy()) {
1330 assert(base->arraycopy_dst(), "sanity");
1331 continue;
1332 }
1333 if (f == field || !f->as_Field()->is_oop())
1334 continue;
1335 int offs = f->as_Field()->offset();
1336 if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1337 add_to_worklist(f);
1338 }
1339 }
1340 }
1341 }
1342 }
1344 // Find fields which have unknown value.
1345 int ConnectionGraph::find_field_value(FieldNode* field) {
1346 // Escaped fields should have init value already.
1347 assert(field->escape_state() == PointsToNode::NoEscape, "sanity");
1348 int new_edges = 0;
1349 for (BaseIterator i(field); i.has_next(); i.next()) {
1350 PointsToNode* base = i.get();
1351 if (base->is_JavaObject()) {
1352 // Skip Allocate's fields which will be processed later.
1353 if (base->ideal_node()->is_Allocate())
1354 return 0;
1355 assert(base == null_obj, "only NULL ptr base expected here");
1356 }
1357 }
1358 if (add_edge(field, phantom_obj)) {
1359 // New edge was added
1360 new_edges++;
1361 add_field_uses_to_worklist(field);
1362 }
1363 return new_edges;
1364 }
1366 // Find fields initializing values for allocations.
1367 int ConnectionGraph::find_init_values(JavaObjectNode* pta, PointsToNode* init_val, PhaseTransform* phase) {
1368 assert(pta->escape_state() == PointsToNode::NoEscape, "Not escaped Allocate nodes only");
1369 int new_edges = 0;
1370 Node* alloc = pta->ideal_node();
1371 if (init_val == phantom_obj) {
1372 // Do nothing for Allocate nodes since its fields values are "known".
1373 if (alloc->is_Allocate())
1374 return 0;
1375 assert(alloc->as_CallStaticJava(), "sanity");
1376 #ifdef ASSERT
1377 if (alloc->as_CallStaticJava()->method() == NULL) {
1378 const char* name = alloc->as_CallStaticJava()->_name;
1379 assert(strncmp(name, "_multianewarray", 15) == 0, "sanity");
1380 }
1381 #endif
1382 // Non-escaped allocation returned from Java or runtime call have
1383 // unknown values in fields.
1384 for (EdgeIterator i(pta); i.has_next(); i.next()) {
1385 PointsToNode* ptn = i.get();
1386 if (ptn->is_Field() && ptn->as_Field()->is_oop()) {
1387 if (add_edge(ptn, phantom_obj)) {
1388 // New edge was added
1389 new_edges++;
1390 add_field_uses_to_worklist(ptn->as_Field());
1391 }
1392 }
1393 }
1394 return new_edges;
1395 }
1396 assert(init_val == null_obj, "sanity");
1397 // Do nothing for Call nodes since its fields values are unknown.
1398 if (!alloc->is_Allocate())
1399 return 0;
1401 InitializeNode* ini = alloc->as_Allocate()->initialization();
1402 Compile* C = _compile;
1403 bool visited_bottom_offset = false;
1404 GrowableArray<int> offsets_worklist;
1406 // Check if an oop field's initializing value is recorded and add
1407 // a corresponding NULL if field's value if it is not recorded.
1408 // Connection Graph does not record a default initialization by NULL
1409 // captured by Initialize node.
1410 //
1411 for (EdgeIterator i(pta); i.has_next(); i.next()) {
1412 PointsToNode* ptn = i.get(); // Field (AddP)
1413 if (!ptn->is_Field() || !ptn->as_Field()->is_oop())
1414 continue; // Not oop field
1415 int offset = ptn->as_Field()->offset();
1416 if (offset == Type::OffsetBot) {
1417 if (!visited_bottom_offset) {
1418 // OffsetBot is used to reference array's element,
1419 // always add reference to NULL to all Field nodes since we don't
1420 // known which element is referenced.
1421 if (add_edge(ptn, null_obj)) {
1422 // New edge was added
1423 new_edges++;
1424 add_field_uses_to_worklist(ptn->as_Field());
1425 visited_bottom_offset = true;
1426 }
1427 }
1428 } else {
1429 // Check only oop fields.
1430 const Type* adr_type = ptn->ideal_node()->as_AddP()->bottom_type();
1431 if (adr_type->isa_rawptr()) {
1432 #ifdef ASSERT
1433 // Raw pointers are used for initializing stores so skip it
1434 // since it should be recorded already
1435 Node* base = get_addp_base(ptn->ideal_node());
1436 assert(adr_type->isa_rawptr() && base->is_Proj() &&
1437 (base->in(0) == alloc),"unexpected pointer type");
1438 #endif
1439 continue;
1440 }
1441 if (!offsets_worklist.contains(offset)) {
1442 offsets_worklist.append(offset);
1443 Node* value = NULL;
1444 if (ini != NULL) {
1445 BasicType ft = UseCompressedOops ? T_NARROWOOP : T_OBJECT;
1446 Node* store = ini->find_captured_store(offset, type2aelembytes(ft), phase);
1447 if (store != NULL && store->is_Store()) {
1448 value = store->in(MemNode::ValueIn);
1449 } else {
1450 // There could be initializing stores which follow allocation.
1451 // For example, a volatile field store is not collected
1452 // by Initialize node.
1453 //
1454 // Need to check for dependent loads to separate such stores from
1455 // stores which follow loads. For now, add initial value NULL so
1456 // that compare pointers optimization works correctly.
1457 }
1458 }
1459 if (value == NULL) {
1460 // A field's initializing value was not recorded. Add NULL.
1461 if (add_edge(ptn, null_obj)) {
1462 // New edge was added
1463 new_edges++;
1464 add_field_uses_to_worklist(ptn->as_Field());
1465 }
1466 }
1467 }
1468 }
1469 }
1470 return new_edges;
1471 }
1473 // Adjust scalar_replaceable state after Connection Graph is built.
1474 void ConnectionGraph::adjust_scalar_replaceable_state(JavaObjectNode* jobj) {
1475 // Search for non-escaping objects which are not scalar replaceable
1476 // and mark them to propagate the state to referenced objects.
1478 // 1. An object is not scalar replaceable if the field into which it is
1479 // stored has unknown offset (stored into unknown element of an array).
1480 //
1481 for (UseIterator i(jobj); i.has_next(); i.next()) {
1482 PointsToNode* use = i.get();
1483 assert(!use->is_Arraycopy(), "sanity");
1484 if (use->is_Field()) {
1485 FieldNode* field = use->as_Field();
1486 assert(field->is_oop() && field->scalar_replaceable() &&
1487 field->fields_escape_state() == PointsToNode::NoEscape, "sanity");
1488 if (field->offset() == Type::OffsetBot) {
1489 jobj->set_scalar_replaceable(false);
1490 return;
1491 }
1492 }
1493 assert(use->is_Field() || use->is_LocalVar(), "sanity");
1494 // 2. An object is not scalar replaceable if it is merged with other objects.
1495 for (EdgeIterator j(use); j.has_next(); j.next()) {
1496 PointsToNode* ptn = j.get();
1497 if (ptn->is_JavaObject() && ptn != jobj) {
1498 // Mark all objects.
1499 jobj->set_scalar_replaceable(false);
1500 ptn->set_scalar_replaceable(false);
1501 }
1502 }
1503 if (!jobj->scalar_replaceable()) {
1504 return;
1505 }
1506 }
1508 for (EdgeIterator j(jobj); j.has_next(); j.next()) {
1509 // Non-escaping object node should point only to field nodes.
1510 FieldNode* field = j.get()->as_Field();
1511 int offset = field->as_Field()->offset();
1513 // 3. An object is not scalar replaceable if it has a field with unknown
1514 // offset (array's element is accessed in loop).
1515 if (offset == Type::OffsetBot) {
1516 jobj->set_scalar_replaceable(false);
1517 return;
1518 }
1519 // 4. Currently an object is not scalar replaceable if a LoadStore node
1520 // access its field since the field value is unknown after it.
1521 //
1522 Node* n = field->ideal_node();
1523 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1524 if (n->fast_out(i)->is_LoadStore()) {
1525 jobj->set_scalar_replaceable(false);
1526 return;
1527 }
1528 }
1530 // 5. Or the address may point to more then one object. This may produce
1531 // the false positive result (set not scalar replaceable)
1532 // since the flow-insensitive escape analysis can't separate
1533 // the case when stores overwrite the field's value from the case
1534 // when stores happened on different control branches.
1535 //
1536 // Note: it will disable scalar replacement in some cases:
1537 //
1538 // Point p[] = new Point[1];
1539 // p[0] = new Point(); // Will be not scalar replaced
1540 //
1541 // but it will save us from incorrect optimizations in next cases:
1542 //
1543 // Point p[] = new Point[1];
1544 // if ( x ) p[0] = new Point(); // Will be not scalar replaced
1545 //
1546 if (field->base_count() > 1) {
1547 for (BaseIterator i(field); i.has_next(); i.next()) {
1548 PointsToNode* base = i.get();
1549 // Don't take into account LocalVar nodes which
1550 // may point to only one object which should be also
1551 // this field's base by now.
1552 if (base->is_JavaObject() && base != jobj) {
1553 // Mark all bases.
1554 jobj->set_scalar_replaceable(false);
1555 base->set_scalar_replaceable(false);
1556 }
1557 }
1558 }
1559 }
1560 }
1562 #ifdef ASSERT
1563 void ConnectionGraph::verify_connection_graph(
1564 GrowableArray<PointsToNode*>& ptnodes_worklist,
1565 GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1566 GrowableArray<JavaObjectNode*>& java_objects_worklist,
1567 GrowableArray<Node*>& addp_worklist) {
1568 // Verify that graph is complete - no new edges could be added.
1569 int java_objects_length = java_objects_worklist.length();
1570 int non_escaped_length = non_escaped_worklist.length();
1571 int new_edges = 0;
1572 for (int next = 0; next < java_objects_length; ++next) {
1573 JavaObjectNode* ptn = java_objects_worklist.at(next);
1574 new_edges += add_java_object_edges(ptn, true);
1575 }
1576 assert(new_edges == 0, "graph was not complete");
1577 // Verify that escape state is final.
1578 int length = non_escaped_worklist.length();
1579 find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist);
1580 assert((non_escaped_length == non_escaped_worklist.length()) &&
1581 (non_escaped_length == length) &&
1582 (_worklist.length() == 0), "escape state was not final");
1584 // Verify fields information.
1585 int addp_length = addp_worklist.length();
1586 for (int next = 0; next < addp_length; ++next ) {
1587 Node* n = addp_worklist.at(next);
1588 FieldNode* field = ptnode_adr(n->_idx)->as_Field();
1589 if (field->is_oop()) {
1590 // Verify that field has all bases
1591 Node* base = get_addp_base(n);
1592 PointsToNode* ptn = ptnode_adr(base->_idx);
1593 if (ptn->is_JavaObject()) {
1594 assert(field->has_base(ptn->as_JavaObject()), "sanity");
1595 } else {
1596 assert(ptn->is_LocalVar(), "sanity");
1597 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1598 PointsToNode* e = i.get();
1599 if (e->is_JavaObject()) {
1600 assert(field->has_base(e->as_JavaObject()), "sanity");
1601 }
1602 }
1603 }
1604 // Verify that all fields have initializing values.
1605 if (field->edge_count() == 0) {
1606 field->dump();
1607 assert(field->edge_count() > 0, "sanity");
1608 }
1609 }
1610 }
1611 }
1612 #endif
1614 // Optimize ideal graph.
1615 void ConnectionGraph::optimize_ideal_graph(GrowableArray<Node*>& ptr_cmp_worklist,
1616 GrowableArray<Node*>& storestore_worklist) {
1617 Compile* C = _compile;
1618 PhaseIterGVN* igvn = _igvn;
1619 if (EliminateLocks) {
1620 // Mark locks before changing ideal graph.
1621 int cnt = C->macro_count();
1622 for( int i=0; i < cnt; i++ ) {
1623 Node *n = C->macro_node(i);
1624 if (n->is_AbstractLock()) { // Lock and Unlock nodes
1625 AbstractLockNode* alock = n->as_AbstractLock();
1626 if (!alock->is_non_esc_obj()) {
1627 if (not_global_escape(alock->obj_node())) {
1628 assert(!alock->is_eliminated() || alock->is_coarsened(), "sanity");
1629 // The lock could be marked eliminated by lock coarsening
1630 // code during first IGVN before EA. Replace coarsened flag
1631 // to eliminate all associated locks/unlocks.
1632 alock->set_non_esc_obj();
1633 }
1634 }
1635 }
1636 }
1637 }
1639 if (OptimizePtrCompare) {
1640 // Add ConI(#CC_GT) and ConI(#CC_EQ).
1641 _pcmp_neq = igvn->makecon(TypeInt::CC_GT);
1642 _pcmp_eq = igvn->makecon(TypeInt::CC_EQ);
1643 // Optimize objects compare.
1644 while (ptr_cmp_worklist.length() != 0) {
1645 Node *n = ptr_cmp_worklist.pop();
1646 Node *res = optimize_ptr_compare(n);
1647 if (res != NULL) {
1648 #ifndef PRODUCT
1649 if (PrintOptimizePtrCompare) {
1650 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"));
1651 if (Verbose) {
1652 n->dump(1);
1653 }
1654 }
1655 #endif
1656 igvn->replace_node(n, res);
1657 }
1658 }
1659 // cleanup
1660 if (_pcmp_neq->outcnt() == 0)
1661 igvn->hash_delete(_pcmp_neq);
1662 if (_pcmp_eq->outcnt() == 0)
1663 igvn->hash_delete(_pcmp_eq);
1664 }
1666 // For MemBarStoreStore nodes added in library_call.cpp, check
1667 // escape status of associated AllocateNode and optimize out
1668 // MemBarStoreStore node if the allocated object never escapes.
1669 while (storestore_worklist.length() != 0) {
1670 Node *n = storestore_worklist.pop();
1671 MemBarStoreStoreNode *storestore = n ->as_MemBarStoreStore();
1672 Node *alloc = storestore->in(MemBarNode::Precedent)->in(0);
1673 assert (alloc->is_Allocate(), "storestore should point to AllocateNode");
1674 if (not_global_escape(alloc)) {
1675 MemBarNode* mb = MemBarNode::make(C, Op_MemBarCPUOrder, Compile::AliasIdxBot);
1676 mb->init_req(TypeFunc::Memory, storestore->in(TypeFunc::Memory));
1677 mb->init_req(TypeFunc::Control, storestore->in(TypeFunc::Control));
1678 igvn->register_new_node_with_optimizer(mb);
1679 igvn->replace_node(storestore, mb);
1680 }
1681 }
1682 }
1684 // Optimize objects compare.
1685 Node* ConnectionGraph::optimize_ptr_compare(Node* n) {
1686 assert(OptimizePtrCompare, "sanity");
1687 PointsToNode* ptn1 = ptnode_adr(n->in(1)->_idx);
1688 PointsToNode* ptn2 = ptnode_adr(n->in(2)->_idx);
1689 JavaObjectNode* jobj1 = unique_java_object(n->in(1));
1690 JavaObjectNode* jobj2 = unique_java_object(n->in(2));
1691 assert(ptn1->is_JavaObject() || ptn1->is_LocalVar(), "sanity");
1692 assert(ptn2->is_JavaObject() || ptn2->is_LocalVar(), "sanity");
1694 // Check simple cases first.
1695 if (jobj1 != NULL) {
1696 if (jobj1->escape_state() == PointsToNode::NoEscape) {
1697 if (jobj1 == jobj2) {
1698 // Comparing the same not escaping object.
1699 return _pcmp_eq;
1700 }
1701 Node* obj = jobj1->ideal_node();
1702 // Comparing not escaping allocation.
1703 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1704 !ptn2->points_to(jobj1)) {
1705 return _pcmp_neq; // This includes nullness check.
1706 }
1707 }
1708 }
1709 if (jobj2 != NULL) {
1710 if (jobj2->escape_state() == PointsToNode::NoEscape) {
1711 Node* obj = jobj2->ideal_node();
1712 // Comparing not escaping allocation.
1713 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1714 !ptn1->points_to(jobj2)) {
1715 return _pcmp_neq; // This includes nullness check.
1716 }
1717 }
1718 }
1719 if (jobj1 != NULL && jobj1 != phantom_obj &&
1720 jobj2 != NULL && jobj2 != phantom_obj &&
1721 jobj1->ideal_node()->is_Con() &&
1722 jobj2->ideal_node()->is_Con()) {
1723 // Klass or String constants compare. Need to be careful with
1724 // compressed pointers - compare types of ConN and ConP instead of nodes.
1725 const Type* t1 = jobj1->ideal_node()->bottom_type()->make_ptr();
1726 const Type* t2 = jobj2->ideal_node()->bottom_type()->make_ptr();
1727 assert(t1 != NULL && t2 != NULL, "sanity");
1728 if (t1->make_ptr() == t2->make_ptr()) {
1729 return _pcmp_eq;
1730 } else {
1731 return _pcmp_neq;
1732 }
1733 }
1734 if (ptn1->meet(ptn2)) {
1735 return NULL; // Sets are not disjoint
1736 }
1738 // Sets are disjoint.
1739 bool set1_has_unknown_ptr = ptn1->points_to(phantom_obj);
1740 bool set2_has_unknown_ptr = ptn2->points_to(phantom_obj);
1741 bool set1_has_null_ptr = ptn1->points_to(null_obj);
1742 bool set2_has_null_ptr = ptn2->points_to(null_obj);
1743 if (set1_has_unknown_ptr && set2_has_null_ptr ||
1744 set2_has_unknown_ptr && set1_has_null_ptr) {
1745 // Check nullness of unknown object.
1746 return NULL;
1747 }
1749 // Disjointness by itself is not sufficient since
1750 // alias analysis is not complete for escaped objects.
1751 // Disjoint sets are definitely unrelated only when
1752 // at least one set has only not escaping allocations.
1753 if (!set1_has_unknown_ptr && !set1_has_null_ptr) {
1754 if (ptn1->non_escaping_allocation()) {
1755 return _pcmp_neq;
1756 }
1757 }
1758 if (!set2_has_unknown_ptr && !set2_has_null_ptr) {
1759 if (ptn2->non_escaping_allocation()) {
1760 return _pcmp_neq;
1761 }
1762 }
1763 return NULL;
1764 }
1766 // Connection Graph constuction functions.
1768 void ConnectionGraph::add_local_var(Node *n, PointsToNode::EscapeState es) {
1769 PointsToNode* ptadr = _nodes.at(n->_idx);
1770 if (ptadr != NULL) {
1771 assert(ptadr->is_LocalVar() && ptadr->ideal_node() == n, "sanity");
1772 return;
1773 }
1774 Compile* C = _compile;
1775 ptadr = new (C->comp_arena()) LocalVarNode(C, n, es);
1776 _nodes.at_put(n->_idx, ptadr);
1777 }
1779 void ConnectionGraph::add_java_object(Node *n, PointsToNode::EscapeState es) {
1780 PointsToNode* ptadr = _nodes.at(n->_idx);
1781 if (ptadr != NULL) {
1782 assert(ptadr->is_JavaObject() && ptadr->ideal_node() == n, "sanity");
1783 return;
1784 }
1785 Compile* C = _compile;
1786 ptadr = new (C->comp_arena()) JavaObjectNode(C, n, es);
1787 _nodes.at_put(n->_idx, ptadr);
1788 }
1790 void ConnectionGraph::add_field(Node *n, PointsToNode::EscapeState es, int offset) {
1791 PointsToNode* ptadr = _nodes.at(n->_idx);
1792 if (ptadr != NULL) {
1793 assert(ptadr->is_Field() && ptadr->ideal_node() == n, "sanity");
1794 return;
1795 }
1796 bool unsafe = false;
1797 bool is_oop = is_oop_field(n, offset, &unsafe);
1798 if (unsafe) {
1799 es = PointsToNode::GlobalEscape;
1800 }
1801 Compile* C = _compile;
1802 FieldNode* field = new (C->comp_arena()) FieldNode(C, n, es, offset, is_oop);
1803 _nodes.at_put(n->_idx, field);
1804 }
1806 void ConnectionGraph::add_arraycopy(Node *n, PointsToNode::EscapeState es,
1807 PointsToNode* src, PointsToNode* dst) {
1808 assert(!src->is_Field() && !dst->is_Field(), "only for JavaObject and LocalVar");
1809 assert((src != null_obj) && (dst != null_obj), "not for ConP NULL");
1810 PointsToNode* ptadr = _nodes.at(n->_idx);
1811 if (ptadr != NULL) {
1812 assert(ptadr->is_Arraycopy() && ptadr->ideal_node() == n, "sanity");
1813 return;
1814 }
1815 Compile* C = _compile;
1816 ptadr = new (C->comp_arena()) ArraycopyNode(C, n, es);
1817 _nodes.at_put(n->_idx, ptadr);
1818 // Add edge from arraycopy node to source object.
1819 (void)add_edge(ptadr, src);
1820 src->set_arraycopy_src();
1821 // Add edge from destination object to arraycopy node.
1822 (void)add_edge(dst, ptadr);
1823 dst->set_arraycopy_dst();
1824 }
1826 bool ConnectionGraph::is_oop_field(Node* n, int offset, bool* unsafe) {
1827 const Type* adr_type = n->as_AddP()->bottom_type();
1828 BasicType bt = T_INT;
1829 if (offset == Type::OffsetBot) {
1830 // Check only oop fields.
1831 if (!adr_type->isa_aryptr() ||
1832 (adr_type->isa_aryptr()->klass() == NULL) ||
1833 adr_type->isa_aryptr()->klass()->is_obj_array_klass()) {
1834 // OffsetBot is used to reference array's element. Ignore first AddP.
1835 if (find_second_addp(n, n->in(AddPNode::Base)) == NULL) {
1836 bt = T_OBJECT;
1837 }
1838 }
1839 } else if (offset != oopDesc::klass_offset_in_bytes()) {
1840 if (adr_type->isa_instptr()) {
1841 ciField* field = _compile->alias_type(adr_type->isa_instptr())->field();
1842 if (field != NULL) {
1843 bt = field->layout_type();
1844 } else {
1845 // Check for unsafe oop field access
1846 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1847 int opcode = n->fast_out(i)->Opcode();
1848 if (opcode == Op_StoreP || opcode == Op_LoadP ||
1849 opcode == Op_StoreN || opcode == Op_LoadN) {
1850 bt = T_OBJECT;
1851 (*unsafe) = true;
1852 break;
1853 }
1854 }
1855 }
1856 } else if (adr_type->isa_aryptr()) {
1857 if (offset == arrayOopDesc::length_offset_in_bytes()) {
1858 // Ignore array length load.
1859 } else if (find_second_addp(n, n->in(AddPNode::Base)) != NULL) {
1860 // Ignore first AddP.
1861 } else {
1862 const Type* elemtype = adr_type->isa_aryptr()->elem();
1863 bt = elemtype->array_element_basic_type();
1864 }
1865 } else if (adr_type->isa_rawptr() || adr_type->isa_klassptr()) {
1866 // Allocation initialization, ThreadLocal field access, unsafe access
1867 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1868 int opcode = n->fast_out(i)->Opcode();
1869 if (opcode == Op_StoreP || opcode == Op_LoadP ||
1870 opcode == Op_StoreN || opcode == Op_LoadN) {
1871 bt = T_OBJECT;
1872 break;
1873 }
1874 }
1875 }
1876 }
1877 return (bt == T_OBJECT || bt == T_NARROWOOP || bt == T_ARRAY);
1878 }
1880 // Returns unique pointed java object or NULL.
1881 JavaObjectNode* ConnectionGraph::unique_java_object(Node *n) {
1882 assert(!_collecting, "should not call when contructed graph");
1883 // If the node was created after the escape computation we can't answer.
1884 uint idx = n->_idx;
1885 if (idx >= nodes_size()) {
1886 return NULL;
1887 }
1888 PointsToNode* ptn = ptnode_adr(idx);
1889 if (ptn->is_JavaObject()) {
1890 return ptn->as_JavaObject();
1891 }
1892 assert(ptn->is_LocalVar(), "sanity");
1893 // Check all java objects it points to.
1894 JavaObjectNode* jobj = NULL;
1895 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1896 PointsToNode* e = i.get();
1897 if (e->is_JavaObject()) {
1898 if (jobj == NULL) {
1899 jobj = e->as_JavaObject();
1900 } else if (jobj != e) {
1901 return NULL;
1902 }
1903 }
1904 }
1905 return jobj;
1906 }
1908 // Return true if this node points only to non-escaping allocations.
1909 bool PointsToNode::non_escaping_allocation() {
1910 if (is_JavaObject()) {
1911 Node* n = ideal_node();
1912 if (n->is_Allocate() || n->is_CallStaticJava()) {
1913 return (escape_state() == PointsToNode::NoEscape);
1914 } else {
1915 return false;
1916 }
1917 }
1918 assert(is_LocalVar(), "sanity");
1919 // Check all java objects it points to.
1920 for (EdgeIterator i(this); i.has_next(); i.next()) {
1921 PointsToNode* e = i.get();
1922 if (e->is_JavaObject()) {
1923 Node* n = e->ideal_node();
1924 if ((e->escape_state() != PointsToNode::NoEscape) ||
1925 !(n->is_Allocate() || n->is_CallStaticJava())) {
1926 return false;
1927 }
1928 }
1929 }
1930 return true;
1931 }
1933 // Return true if we know the node does not escape globally.
1934 bool ConnectionGraph::not_global_escape(Node *n) {
1935 assert(!_collecting, "should not call during graph construction");
1936 // If the node was created after the escape computation we can't answer.
1937 uint idx = n->_idx;
1938 if (idx >= nodes_size()) {
1939 return false;
1940 }
1941 PointsToNode* ptn = ptnode_adr(idx);
1942 PointsToNode::EscapeState es = ptn->escape_state();
1943 // If we have already computed a value, return it.
1944 if (es >= PointsToNode::GlobalEscape)
1945 return false;
1946 if (ptn->is_JavaObject()) {
1947 return true; // (es < PointsToNode::GlobalEscape);
1948 }
1949 assert(ptn->is_LocalVar(), "sanity");
1950 // Check all java objects it points to.
1951 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1952 if (i.get()->escape_state() >= PointsToNode::GlobalEscape)
1953 return false;
1954 }
1955 return true;
1956 }
1959 // Helper functions
1961 // Return true if this node points to specified node or nodes it points to.
1962 bool PointsToNode::points_to(JavaObjectNode* ptn) const {
1963 if (is_JavaObject()) {
1964 return (this == ptn);
1965 }
1966 assert(is_LocalVar(), "sanity");
1967 for (EdgeIterator i(this); i.has_next(); i.next()) {
1968 if (i.get() == ptn)
1969 return true;
1970 }
1971 return false;
1972 }
1974 // Return true if one node points to an other.
1975 bool PointsToNode::meet(PointsToNode* ptn) {
1976 if (this == ptn) {
1977 return true;
1978 } else if (ptn->is_JavaObject()) {
1979 return this->points_to(ptn->as_JavaObject());
1980 } else if (this->is_JavaObject()) {
1981 return ptn->points_to(this->as_JavaObject());
1982 }
1983 assert(this->is_LocalVar() && ptn->is_LocalVar(), "sanity");
1984 int ptn_count = ptn->edge_count();
1985 for (EdgeIterator i(this); i.has_next(); i.next()) {
1986 PointsToNode* this_e = i.get();
1987 for (int j = 0; j < ptn_count; j++) {
1988 if (this_e == ptn->edge(j))
1989 return true;
1990 }
1991 }
1992 return false;
1993 }
1995 #ifdef ASSERT
1996 // Return true if bases point to this java object.
1997 bool FieldNode::has_base(JavaObjectNode* jobj) const {
1998 for (BaseIterator i(this); i.has_next(); i.next()) {
1999 if (i.get() == jobj)
2000 return true;
2001 }
2002 return false;
2003 }
2004 #endif
2006 int ConnectionGraph::address_offset(Node* adr, PhaseTransform *phase) {
2007 const Type *adr_type = phase->type(adr);
2008 if (adr->is_AddP() && adr_type->isa_oopptr() == NULL &&
2009 adr->in(AddPNode::Address)->is_Proj() &&
2010 adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
2011 // We are computing a raw address for a store captured by an Initialize
2012 // compute an appropriate address type. AddP cases #3 and #5 (see below).
2013 int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
2014 assert(offs != Type::OffsetBot ||
2015 adr->in(AddPNode::Address)->in(0)->is_AllocateArray(),
2016 "offset must be a constant or it is initialization of array");
2017 return offs;
2018 }
2019 const TypePtr *t_ptr = adr_type->isa_ptr();
2020 assert(t_ptr != NULL, "must be a pointer type");
2021 return t_ptr->offset();
2022 }
2024 Node* ConnectionGraph::get_addp_base(Node *addp) {
2025 assert(addp->is_AddP(), "must be AddP");
2026 //
2027 // AddP cases for Base and Address inputs:
2028 // case #1. Direct object's field reference:
2029 // Allocate
2030 // |
2031 // Proj #5 ( oop result )
2032 // |
2033 // CheckCastPP (cast to instance type)
2034 // | |
2035 // AddP ( base == address )
2036 //
2037 // case #2. Indirect object's field reference:
2038 // Phi
2039 // |
2040 // CastPP (cast to instance type)
2041 // | |
2042 // AddP ( base == address )
2043 //
2044 // case #3. Raw object's field reference for Initialize node:
2045 // Allocate
2046 // |
2047 // Proj #5 ( oop result )
2048 // top |
2049 // \ |
2050 // AddP ( base == top )
2051 //
2052 // case #4. Array's element reference:
2053 // {CheckCastPP | CastPP}
2054 // | | |
2055 // | AddP ( array's element offset )
2056 // | |
2057 // AddP ( array's offset )
2058 //
2059 // case #5. Raw object's field reference for arraycopy stub call:
2060 // The inline_native_clone() case when the arraycopy stub is called
2061 // after the allocation before Initialize and CheckCastPP nodes.
2062 // Allocate
2063 // |
2064 // Proj #5 ( oop result )
2065 // | |
2066 // AddP ( base == address )
2067 //
2068 // case #6. Constant Pool, ThreadLocal, CastX2P or
2069 // Raw object's field reference:
2070 // {ConP, ThreadLocal, CastX2P, raw Load}
2071 // top |
2072 // \ |
2073 // AddP ( base == top )
2074 //
2075 // case #7. Klass's field reference.
2076 // LoadKlass
2077 // | |
2078 // AddP ( base == address )
2079 //
2080 // case #8. narrow Klass's field reference.
2081 // LoadNKlass
2082 // |
2083 // DecodeN
2084 // | |
2085 // AddP ( base == address )
2086 //
2087 Node *base = addp->in(AddPNode::Base);
2088 if (base->uncast()->is_top()) { // The AddP case #3 and #6.
2089 base = addp->in(AddPNode::Address);
2090 while (base->is_AddP()) {
2091 // Case #6 (unsafe access) may have several chained AddP nodes.
2092 assert(base->in(AddPNode::Base)->uncast()->is_top(), "expected unsafe access address only");
2093 base = base->in(AddPNode::Address);
2094 }
2095 Node* uncast_base = base->uncast();
2096 int opcode = uncast_base->Opcode();
2097 assert(opcode == Op_ConP || opcode == Op_ThreadLocal ||
2098 opcode == Op_CastX2P || uncast_base->is_DecodeNarrowPtr() ||
2099 (uncast_base->is_Mem() && uncast_base->bottom_type() == TypeRawPtr::NOTNULL) ||
2100 (uncast_base->is_Proj() && uncast_base->in(0)->is_Allocate()), "sanity");
2101 }
2102 return base;
2103 }
2105 Node* ConnectionGraph::find_second_addp(Node* addp, Node* n) {
2106 assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
2107 Node* addp2 = addp->raw_out(0);
2108 if (addp->outcnt() == 1 && addp2->is_AddP() &&
2109 addp2->in(AddPNode::Base) == n &&
2110 addp2->in(AddPNode::Address) == addp) {
2111 assert(addp->in(AddPNode::Base) == n, "expecting the same base");
2112 //
2113 // Find array's offset to push it on worklist first and
2114 // as result process an array's element offset first (pushed second)
2115 // to avoid CastPP for the array's offset.
2116 // Otherwise the inserted CastPP (LocalVar) will point to what
2117 // the AddP (Field) points to. Which would be wrong since
2118 // the algorithm expects the CastPP has the same point as
2119 // as AddP's base CheckCastPP (LocalVar).
2120 //
2121 // ArrayAllocation
2122 // |
2123 // CheckCastPP
2124 // |
2125 // memProj (from ArrayAllocation CheckCastPP)
2126 // | ||
2127 // | || Int (element index)
2128 // | || | ConI (log(element size))
2129 // | || | /
2130 // | || LShift
2131 // | || /
2132 // | AddP (array's element offset)
2133 // | |
2134 // | | ConI (array's offset: #12(32-bits) or #24(64-bits))
2135 // | / /
2136 // AddP (array's offset)
2137 // |
2138 // Load/Store (memory operation on array's element)
2139 //
2140 return addp2;
2141 }
2142 return NULL;
2143 }
2145 //
2146 // Adjust the type and inputs of an AddP which computes the
2147 // address of a field of an instance
2148 //
2149 bool ConnectionGraph::split_AddP(Node *addp, Node *base) {
2150 PhaseGVN* igvn = _igvn;
2151 const TypeOopPtr *base_t = igvn->type(base)->isa_oopptr();
2152 assert(base_t != NULL && base_t->is_known_instance(), "expecting instance oopptr");
2153 const TypeOopPtr *t = igvn->type(addp)->isa_oopptr();
2154 if (t == NULL) {
2155 // We are computing a raw address for a store captured by an Initialize
2156 // compute an appropriate address type (cases #3 and #5).
2157 assert(igvn->type(addp) == TypeRawPtr::NOTNULL, "must be raw pointer");
2158 assert(addp->in(AddPNode::Address)->is_Proj(), "base of raw address must be result projection from allocation");
2159 intptr_t offs = (int)igvn->find_intptr_t_con(addp->in(AddPNode::Offset), Type::OffsetBot);
2160 assert(offs != Type::OffsetBot, "offset must be a constant");
2161 t = base_t->add_offset(offs)->is_oopptr();
2162 }
2163 int inst_id = base_t->instance_id();
2164 assert(!t->is_known_instance() || t->instance_id() == inst_id,
2165 "old type must be non-instance or match new type");
2167 // The type 't' could be subclass of 'base_t'.
2168 // As result t->offset() could be large then base_t's size and it will
2169 // cause the failure in add_offset() with narrow oops since TypeOopPtr()
2170 // constructor verifies correctness of the offset.
2171 //
2172 // It could happened on subclass's branch (from the type profiling
2173 // inlining) which was not eliminated during parsing since the exactness
2174 // of the allocation type was not propagated to the subclass type check.
2175 //
2176 // Or the type 't' could be not related to 'base_t' at all.
2177 // It could happened when CHA type is different from MDO type on a dead path
2178 // (for example, from instanceof check) which is not collapsed during parsing.
2179 //
2180 // Do nothing for such AddP node and don't process its users since
2181 // this code branch will go away.
2182 //
2183 if (!t->is_known_instance() &&
2184 !base_t->klass()->is_subtype_of(t->klass())) {
2185 return false; // bail out
2186 }
2187 const TypeOopPtr *tinst = base_t->add_offset(t->offset())->is_oopptr();
2188 // Do NOT remove the next line: ensure a new alias index is allocated
2189 // for the instance type. Note: C++ will not remove it since the call
2190 // has side effect.
2191 int alias_idx = _compile->get_alias_index(tinst);
2192 igvn->set_type(addp, tinst);
2193 // record the allocation in the node map
2194 set_map(addp, get_map(base->_idx));
2195 // Set addp's Base and Address to 'base'.
2196 Node *abase = addp->in(AddPNode::Base);
2197 Node *adr = addp->in(AddPNode::Address);
2198 if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
2199 adr->in(0)->_idx == (uint)inst_id) {
2200 // Skip AddP cases #3 and #5.
2201 } else {
2202 assert(!abase->is_top(), "sanity"); // AddP case #3
2203 if (abase != base) {
2204 igvn->hash_delete(addp);
2205 addp->set_req(AddPNode::Base, base);
2206 if (abase == adr) {
2207 addp->set_req(AddPNode::Address, base);
2208 } else {
2209 // AddP case #4 (adr is array's element offset AddP node)
2210 #ifdef ASSERT
2211 const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
2212 assert(adr->is_AddP() && atype != NULL &&
2213 atype->instance_id() == inst_id, "array's element offset should be processed first");
2214 #endif
2215 }
2216 igvn->hash_insert(addp);
2217 }
2218 }
2219 // Put on IGVN worklist since at least addp's type was changed above.
2220 record_for_optimizer(addp);
2221 return true;
2222 }
2224 //
2225 // Create a new version of orig_phi if necessary. Returns either the newly
2226 // created phi or an existing phi. Sets create_new to indicate whether a new
2227 // phi was created. Cache the last newly created phi in the node map.
2228 //
2229 PhiNode *ConnectionGraph::create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist, bool &new_created) {
2230 Compile *C = _compile;
2231 PhaseGVN* igvn = _igvn;
2232 new_created = false;
2233 int phi_alias_idx = C->get_alias_index(orig_phi->adr_type());
2234 // nothing to do if orig_phi is bottom memory or matches alias_idx
2235 if (phi_alias_idx == alias_idx) {
2236 return orig_phi;
2237 }
2238 // Have we recently created a Phi for this alias index?
2239 PhiNode *result = get_map_phi(orig_phi->_idx);
2240 if (result != NULL && C->get_alias_index(result->adr_type()) == alias_idx) {
2241 return result;
2242 }
2243 // Previous check may fail when the same wide memory Phi was split into Phis
2244 // for different memory slices. Search all Phis for this region.
2245 if (result != NULL) {
2246 Node* region = orig_phi->in(0);
2247 for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
2248 Node* phi = region->fast_out(i);
2249 if (phi->is_Phi() &&
2250 C->get_alias_index(phi->as_Phi()->adr_type()) == alias_idx) {
2251 assert(phi->_idx >= nodes_size(), "only new Phi per instance memory slice");
2252 return phi->as_Phi();
2253 }
2254 }
2255 }
2256 if ((int)C->unique() + 2*NodeLimitFudgeFactor > MaxNodeLimit) {
2257 if (C->do_escape_analysis() == true && !C->failing()) {
2258 // Retry compilation without escape analysis.
2259 // If this is the first failure, the sentinel string will "stick"
2260 // to the Compile object, and the C2Compiler will see it and retry.
2261 C->record_failure(C2Compiler::retry_no_escape_analysis());
2262 }
2263 return NULL;
2264 }
2265 orig_phi_worklist.append_if_missing(orig_phi);
2266 const TypePtr *atype = C->get_adr_type(alias_idx);
2267 result = PhiNode::make(orig_phi->in(0), NULL, Type::MEMORY, atype);
2268 C->copy_node_notes_to(result, orig_phi);
2269 igvn->set_type(result, result->bottom_type());
2270 record_for_optimizer(result);
2271 set_map(orig_phi, result);
2272 new_created = true;
2273 return result;
2274 }
2276 //
2277 // Return a new version of Memory Phi "orig_phi" with the inputs having the
2278 // specified alias index.
2279 //
2280 PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist) {
2281 assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
2282 Compile *C = _compile;
2283 PhaseGVN* igvn = _igvn;
2284 bool new_phi_created;
2285 PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, new_phi_created);
2286 if (!new_phi_created) {
2287 return result;
2288 }
2289 GrowableArray<PhiNode *> phi_list;
2290 GrowableArray<uint> cur_input;
2291 PhiNode *phi = orig_phi;
2292 uint idx = 1;
2293 bool finished = false;
2294 while(!finished) {
2295 while (idx < phi->req()) {
2296 Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist);
2297 if (mem != NULL && mem->is_Phi()) {
2298 PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, new_phi_created);
2299 if (new_phi_created) {
2300 // found an phi for which we created a new split, push current one on worklist and begin
2301 // processing new one
2302 phi_list.push(phi);
2303 cur_input.push(idx);
2304 phi = mem->as_Phi();
2305 result = newphi;
2306 idx = 1;
2307 continue;
2308 } else {
2309 mem = newphi;
2310 }
2311 }
2312 if (C->failing()) {
2313 return NULL;
2314 }
2315 result->set_req(idx++, mem);
2316 }
2317 #ifdef ASSERT
2318 // verify that the new Phi has an input for each input of the original
2319 assert( phi->req() == result->req(), "must have same number of inputs.");
2320 assert( result->in(0) != NULL && result->in(0) == phi->in(0), "regions must match");
2321 #endif
2322 // Check if all new phi's inputs have specified alias index.
2323 // Otherwise use old phi.
2324 for (uint i = 1; i < phi->req(); i++) {
2325 Node* in = result->in(i);
2326 assert((phi->in(i) == NULL) == (in == NULL), "inputs must correspond.");
2327 }
2328 // we have finished processing a Phi, see if there are any more to do
2329 finished = (phi_list.length() == 0 );
2330 if (!finished) {
2331 phi = phi_list.pop();
2332 idx = cur_input.pop();
2333 PhiNode *prev_result = get_map_phi(phi->_idx);
2334 prev_result->set_req(idx++, result);
2335 result = prev_result;
2336 }
2337 }
2338 return result;
2339 }
2341 //
2342 // The next methods are derived from methods in MemNode.
2343 //
2344 Node* ConnectionGraph::step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *toop) {
2345 Node *mem = mmem;
2346 // TypeOopPtr::NOTNULL+any is an OOP with unknown offset - generally
2347 // means an array I have not precisely typed yet. Do not do any
2348 // alias stuff with it any time soon.
2349 if (toop->base() != Type::AnyPtr &&
2350 !(toop->klass() != NULL &&
2351 toop->klass()->is_java_lang_Object() &&
2352 toop->offset() == Type::OffsetBot)) {
2353 mem = mmem->memory_at(alias_idx);
2354 // Update input if it is progress over what we have now
2355 }
2356 return mem;
2357 }
2359 //
2360 // Move memory users to their memory slices.
2361 //
2362 void ConnectionGraph::move_inst_mem(Node* n, GrowableArray<PhiNode *> &orig_phis) {
2363 Compile* C = _compile;
2364 PhaseGVN* igvn = _igvn;
2365 const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr();
2366 assert(tp != NULL, "ptr type");
2367 int alias_idx = C->get_alias_index(tp);
2368 int general_idx = C->get_general_index(alias_idx);
2370 // Move users first
2371 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2372 Node* use = n->fast_out(i);
2373 if (use->is_MergeMem()) {
2374 MergeMemNode* mmem = use->as_MergeMem();
2375 assert(n == mmem->memory_at(alias_idx), "should be on instance memory slice");
2376 if (n != mmem->memory_at(general_idx) || alias_idx == general_idx) {
2377 continue; // Nothing to do
2378 }
2379 // Replace previous general reference to mem node.
2380 uint orig_uniq = C->unique();
2381 Node* m = find_inst_mem(n, general_idx, orig_phis);
2382 assert(orig_uniq == C->unique(), "no new nodes");
2383 mmem->set_memory_at(general_idx, m);
2384 --imax;
2385 --i;
2386 } else if (use->is_MemBar()) {
2387 assert(!use->is_Initialize(), "initializing stores should not be moved");
2388 if (use->req() > MemBarNode::Precedent &&
2389 use->in(MemBarNode::Precedent) == n) {
2390 // Don't move related membars.
2391 record_for_optimizer(use);
2392 continue;
2393 }
2394 tp = use->as_MemBar()->adr_type()->isa_ptr();
2395 if (tp != NULL && C->get_alias_index(tp) == alias_idx ||
2396 alias_idx == general_idx) {
2397 continue; // Nothing to do
2398 }
2399 // Move to general memory slice.
2400 uint orig_uniq = C->unique();
2401 Node* m = find_inst_mem(n, general_idx, orig_phis);
2402 assert(orig_uniq == C->unique(), "no new nodes");
2403 igvn->hash_delete(use);
2404 imax -= use->replace_edge(n, m);
2405 igvn->hash_insert(use);
2406 record_for_optimizer(use);
2407 --i;
2408 #ifdef ASSERT
2409 } else if (use->is_Mem()) {
2410 if (use->Opcode() == Op_StoreCM && use->in(MemNode::OopStore) == n) {
2411 // Don't move related cardmark.
2412 continue;
2413 }
2414 // Memory nodes should have new memory input.
2415 tp = igvn->type(use->in(MemNode::Address))->isa_ptr();
2416 assert(tp != NULL, "ptr type");
2417 int idx = C->get_alias_index(tp);
2418 assert(get_map(use->_idx) != NULL || idx == alias_idx,
2419 "Following memory nodes should have new memory input or be on the same memory slice");
2420 } else if (use->is_Phi()) {
2421 // Phi nodes should be split and moved already.
2422 tp = use->as_Phi()->adr_type()->isa_ptr();
2423 assert(tp != NULL, "ptr type");
2424 int idx = C->get_alias_index(tp);
2425 assert(idx == alias_idx, "Following Phi nodes should be on the same memory slice");
2426 } else {
2427 use->dump();
2428 assert(false, "should not be here");
2429 #endif
2430 }
2431 }
2432 }
2434 //
2435 // Search memory chain of "mem" to find a MemNode whose address
2436 // is the specified alias index.
2437 //
2438 Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArray<PhiNode *> &orig_phis) {
2439 if (orig_mem == NULL)
2440 return orig_mem;
2441 Compile* C = _compile;
2442 PhaseGVN* igvn = _igvn;
2443 const TypeOopPtr *toop = C->get_adr_type(alias_idx)->isa_oopptr();
2444 bool is_instance = (toop != NULL) && toop->is_known_instance();
2445 Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
2446 Node *prev = NULL;
2447 Node *result = orig_mem;
2448 while (prev != result) {
2449 prev = result;
2450 if (result == start_mem)
2451 break; // hit one of our sentinels
2452 if (result->is_Mem()) {
2453 const Type *at = igvn->type(result->in(MemNode::Address));
2454 if (at == Type::TOP)
2455 break; // Dead
2456 assert (at->isa_ptr() != NULL, "pointer type required.");
2457 int idx = C->get_alias_index(at->is_ptr());
2458 if (idx == alias_idx)
2459 break; // Found
2460 if (!is_instance && (at->isa_oopptr() == NULL ||
2461 !at->is_oopptr()->is_known_instance())) {
2462 break; // Do not skip store to general memory slice.
2463 }
2464 result = result->in(MemNode::Memory);
2465 }
2466 if (!is_instance)
2467 continue; // don't search further for non-instance types
2468 // skip over a call which does not affect this memory slice
2469 if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) {
2470 Node *proj_in = result->in(0);
2471 if (proj_in->is_Allocate() && proj_in->_idx == (uint)toop->instance_id()) {
2472 break; // hit one of our sentinels
2473 } else if (proj_in->is_Call()) {
2474 CallNode *call = proj_in->as_Call();
2475 if (!call->may_modify(toop, igvn)) {
2476 result = call->in(TypeFunc::Memory);
2477 }
2478 } else if (proj_in->is_Initialize()) {
2479 AllocateNode* alloc = proj_in->as_Initialize()->allocation();
2480 // Stop if this is the initialization for the object instance which
2481 // which contains this memory slice, otherwise skip over it.
2482 if (alloc == NULL || alloc->_idx != (uint)toop->instance_id()) {
2483 result = proj_in->in(TypeFunc::Memory);
2484 }
2485 } else if (proj_in->is_MemBar()) {
2486 result = proj_in->in(TypeFunc::Memory);
2487 }
2488 } else if (result->is_MergeMem()) {
2489 MergeMemNode *mmem = result->as_MergeMem();
2490 result = step_through_mergemem(mmem, alias_idx, toop);
2491 if (result == mmem->base_memory()) {
2492 // Didn't find instance memory, search through general slice recursively.
2493 result = mmem->memory_at(C->get_general_index(alias_idx));
2494 result = find_inst_mem(result, alias_idx, orig_phis);
2495 if (C->failing()) {
2496 return NULL;
2497 }
2498 mmem->set_memory_at(alias_idx, result);
2499 }
2500 } else if (result->is_Phi() &&
2501 C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) {
2502 Node *un = result->as_Phi()->unique_input(igvn);
2503 if (un != NULL) {
2504 orig_phis.append_if_missing(result->as_Phi());
2505 result = un;
2506 } else {
2507 break;
2508 }
2509 } else if (result->is_ClearArray()) {
2510 if (!ClearArrayNode::step_through(&result, (uint)toop->instance_id(), igvn)) {
2511 // Can not bypass initialization of the instance
2512 // we are looking for.
2513 break;
2514 }
2515 // Otherwise skip it (the call updated 'result' value).
2516 } else if (result->Opcode() == Op_SCMemProj) {
2517 assert(result->in(0)->is_LoadStore(), "sanity");
2518 const Type *at = igvn->type(result->in(0)->in(MemNode::Address));
2519 if (at != Type::TOP) {
2520 assert (at->isa_ptr() != NULL, "pointer type required.");
2521 int idx = C->get_alias_index(at->is_ptr());
2522 assert(idx != alias_idx, "Object is not scalar replaceable if a LoadStore node access its field");
2523 break;
2524 }
2525 result = result->in(0)->in(MemNode::Memory);
2526 }
2527 }
2528 if (result->is_Phi()) {
2529 PhiNode *mphi = result->as_Phi();
2530 assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
2531 const TypePtr *t = mphi->adr_type();
2532 if (!is_instance) {
2533 // Push all non-instance Phis on the orig_phis worklist to update inputs
2534 // during Phase 4 if needed.
2535 orig_phis.append_if_missing(mphi);
2536 } else if (C->get_alias_index(t) != alias_idx) {
2537 // Create a new Phi with the specified alias index type.
2538 result = split_memory_phi(mphi, alias_idx, orig_phis);
2539 }
2540 }
2541 // the result is either MemNode, PhiNode, InitializeNode.
2542 return result;
2543 }
2545 //
2546 // Convert the types of unescaped object to instance types where possible,
2547 // propagate the new type information through the graph, and update memory
2548 // edges and MergeMem inputs to reflect the new type.
2549 //
2550 // We start with allocations (and calls which may be allocations) on alloc_worklist.
2551 // The processing is done in 4 phases:
2552 //
2553 // Phase 1: Process possible allocations from alloc_worklist. Create instance
2554 // types for the CheckCastPP for allocations where possible.
2555 // Propagate the the new types through users as follows:
2556 // casts and Phi: push users on alloc_worklist
2557 // AddP: cast Base and Address inputs to the instance type
2558 // push any AddP users on alloc_worklist and push any memnode
2559 // users onto memnode_worklist.
2560 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
2561 // search the Memory chain for a store with the appropriate type
2562 // address type. If a Phi is found, create a new version with
2563 // the appropriate memory slices from each of the Phi inputs.
2564 // For stores, process the users as follows:
2565 // MemNode: push on memnode_worklist
2566 // MergeMem: push on mergemem_worklist
2567 // Phase 3: Process MergeMem nodes from mergemem_worklist. Walk each memory slice
2568 // moving the first node encountered of each instance type to the
2569 // the input corresponding to its alias index.
2570 // appropriate memory slice.
2571 // Phase 4: Update the inputs of non-instance memory Phis and the Memory input of memnodes.
2572 //
2573 // In the following example, the CheckCastPP nodes are the cast of allocation
2574 // results and the allocation of node 29 is unescaped and eligible to be an
2575 // instance type.
2576 //
2577 // We start with:
2578 //
2579 // 7 Parm #memory
2580 // 10 ConI "12"
2581 // 19 CheckCastPP "Foo"
2582 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2583 // 29 CheckCastPP "Foo"
2584 // 30 AddP _ 29 29 10 Foo+12 alias_index=4
2585 //
2586 // 40 StoreP 25 7 20 ... alias_index=4
2587 // 50 StoreP 35 40 30 ... alias_index=4
2588 // 60 StoreP 45 50 20 ... alias_index=4
2589 // 70 LoadP _ 60 30 ... alias_index=4
2590 // 80 Phi 75 50 60 Memory alias_index=4
2591 // 90 LoadP _ 80 30 ... alias_index=4
2592 // 100 LoadP _ 80 20 ... alias_index=4
2593 //
2594 //
2595 // Phase 1 creates an instance type for node 29 assigning it an instance id of 24
2596 // and creating a new alias index for node 30. This gives:
2597 //
2598 // 7 Parm #memory
2599 // 10 ConI "12"
2600 // 19 CheckCastPP "Foo"
2601 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2602 // 29 CheckCastPP "Foo" iid=24
2603 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
2604 //
2605 // 40 StoreP 25 7 20 ... alias_index=4
2606 // 50 StoreP 35 40 30 ... alias_index=6
2607 // 60 StoreP 45 50 20 ... alias_index=4
2608 // 70 LoadP _ 60 30 ... alias_index=6
2609 // 80 Phi 75 50 60 Memory alias_index=4
2610 // 90 LoadP _ 80 30 ... alias_index=6
2611 // 100 LoadP _ 80 20 ... alias_index=4
2612 //
2613 // In phase 2, new memory inputs are computed for the loads and stores,
2614 // And a new version of the phi is created. In phase 4, the inputs to
2615 // node 80 are updated and then the memory nodes are updated with the
2616 // values computed in phase 2. This results in:
2617 //
2618 // 7 Parm #memory
2619 // 10 ConI "12"
2620 // 19 CheckCastPP "Foo"
2621 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2622 // 29 CheckCastPP "Foo" iid=24
2623 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
2624 //
2625 // 40 StoreP 25 7 20 ... alias_index=4
2626 // 50 StoreP 35 7 30 ... alias_index=6
2627 // 60 StoreP 45 40 20 ... alias_index=4
2628 // 70 LoadP _ 50 30 ... alias_index=6
2629 // 80 Phi 75 40 60 Memory alias_index=4
2630 // 120 Phi 75 50 50 Memory alias_index=6
2631 // 90 LoadP _ 120 30 ... alias_index=6
2632 // 100 LoadP _ 80 20 ... alias_index=4
2633 //
2634 void ConnectionGraph::split_unique_types(GrowableArray<Node *> &alloc_worklist) {
2635 GrowableArray<Node *> memnode_worklist;
2636 GrowableArray<PhiNode *> orig_phis;
2637 PhaseIterGVN *igvn = _igvn;
2638 uint new_index_start = (uint) _compile->num_alias_types();
2639 Arena* arena = Thread::current()->resource_area();
2640 VectorSet visited(arena);
2641 ideal_nodes.clear(); // Reset for use with set_map/get_map.
2642 uint unique_old = _compile->unique();
2644 // Phase 1: Process possible allocations from alloc_worklist.
2645 // Create instance types for the CheckCastPP for allocations where possible.
2646 //
2647 // (Note: don't forget to change the order of the second AddP node on
2648 // the alloc_worklist if the order of the worklist processing is changed,
2649 // see the comment in find_second_addp().)
2650 //
2651 while (alloc_worklist.length() != 0) {
2652 Node *n = alloc_worklist.pop();
2653 uint ni = n->_idx;
2654 if (n->is_Call()) {
2655 CallNode *alloc = n->as_Call();
2656 // copy escape information to call node
2657 PointsToNode* ptn = ptnode_adr(alloc->_idx);
2658 PointsToNode::EscapeState es = ptn->escape_state();
2659 // We have an allocation or call which returns a Java object,
2660 // see if it is unescaped.
2661 if (es != PointsToNode::NoEscape || !ptn->scalar_replaceable())
2662 continue;
2663 // Find CheckCastPP for the allocate or for the return value of a call
2664 n = alloc->result_cast();
2665 if (n == NULL) { // No uses except Initialize node
2666 if (alloc->is_Allocate()) {
2667 // Set the scalar_replaceable flag for allocation
2668 // so it could be eliminated if it has no uses.
2669 alloc->as_Allocate()->_is_scalar_replaceable = true;
2670 }
2671 continue;
2672 }
2673 if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
2674 assert(!alloc->is_Allocate(), "allocation should have unique type");
2675 continue;
2676 }
2678 // The inline code for Object.clone() casts the allocation result to
2679 // java.lang.Object and then to the actual type of the allocated
2680 // object. Detect this case and use the second cast.
2681 // Also detect j.l.reflect.Array.newInstance(jobject, jint) case when
2682 // the allocation result is cast to java.lang.Object and then
2683 // to the actual Array type.
2684 if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL
2685 && (alloc->is_AllocateArray() ||
2686 igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeKlassPtr::OBJECT)) {
2687 Node *cast2 = NULL;
2688 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2689 Node *use = n->fast_out(i);
2690 if (use->is_CheckCastPP()) {
2691 cast2 = use;
2692 break;
2693 }
2694 }
2695 if (cast2 != NULL) {
2696 n = cast2;
2697 } else {
2698 // Non-scalar replaceable if the allocation type is unknown statically
2699 // (reflection allocation), the object can't be restored during
2700 // deoptimization without precise type.
2701 continue;
2702 }
2703 }
2704 if (alloc->is_Allocate()) {
2705 // Set the scalar_replaceable flag for allocation
2706 // so it could be eliminated.
2707 alloc->as_Allocate()->_is_scalar_replaceable = true;
2708 }
2709 set_escape_state(ptnode_adr(n->_idx), es); // CheckCastPP escape state
2710 // in order for an object to be scalar-replaceable, it must be:
2711 // - a direct allocation (not a call returning an object)
2712 // - non-escaping
2713 // - eligible to be a unique type
2714 // - not determined to be ineligible by escape analysis
2715 set_map(alloc, n);
2716 set_map(n, alloc);
2717 const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
2718 if (t == NULL)
2719 continue; // not a TypeOopPtr
2720 const TypeOopPtr* tinst = t->cast_to_exactness(true)->is_oopptr()->cast_to_instance_id(ni);
2721 igvn->hash_delete(n);
2722 igvn->set_type(n, tinst);
2723 n->raise_bottom_type(tinst);
2724 igvn->hash_insert(n);
2725 record_for_optimizer(n);
2726 if (alloc->is_Allocate() && (t->isa_instptr() || t->isa_aryptr())) {
2728 // First, put on the worklist all Field edges from Connection Graph
2729 // which is more accurate then putting immediate users from Ideal Graph.
2730 for (EdgeIterator e(ptn); e.has_next(); e.next()) {
2731 PointsToNode* tgt = e.get();
2732 Node* use = tgt->ideal_node();
2733 assert(tgt->is_Field() && use->is_AddP(),
2734 "only AddP nodes are Field edges in CG");
2735 if (use->outcnt() > 0) { // Don't process dead nodes
2736 Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
2737 if (addp2 != NULL) {
2738 assert(alloc->is_AllocateArray(),"array allocation was expected");
2739 alloc_worklist.append_if_missing(addp2);
2740 }
2741 alloc_worklist.append_if_missing(use);
2742 }
2743 }
2745 // An allocation may have an Initialize which has raw stores. Scan
2746 // the users of the raw allocation result and push AddP users
2747 // on alloc_worklist.
2748 Node *raw_result = alloc->proj_out(TypeFunc::Parms);
2749 assert (raw_result != NULL, "must have an allocation result");
2750 for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
2751 Node *use = raw_result->fast_out(i);
2752 if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
2753 Node* addp2 = find_second_addp(use, raw_result);
2754 if (addp2 != NULL) {
2755 assert(alloc->is_AllocateArray(),"array allocation was expected");
2756 alloc_worklist.append_if_missing(addp2);
2757 }
2758 alloc_worklist.append_if_missing(use);
2759 } else if (use->is_MemBar()) {
2760 memnode_worklist.append_if_missing(use);
2761 }
2762 }
2763 }
2764 } else if (n->is_AddP()) {
2765 JavaObjectNode* jobj = unique_java_object(get_addp_base(n));
2766 if (jobj == NULL || jobj == phantom_obj) {
2767 #ifdef ASSERT
2768 ptnode_adr(get_addp_base(n)->_idx)->dump();
2769 ptnode_adr(n->_idx)->dump();
2770 assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
2771 #endif
2772 _compile->record_failure(C2Compiler::retry_no_escape_analysis());
2773 return;
2774 }
2775 Node *base = get_map(jobj->idx()); // CheckCastPP node
2776 if (!split_AddP(n, base)) continue; // wrong type from dead path
2777 } else if (n->is_Phi() ||
2778 n->is_CheckCastPP() ||
2779 n->is_EncodeP() ||
2780 n->is_DecodeN() ||
2781 (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
2782 if (visited.test_set(n->_idx)) {
2783 assert(n->is_Phi(), "loops only through Phi's");
2784 continue; // already processed
2785 }
2786 JavaObjectNode* jobj = unique_java_object(n);
2787 if (jobj == NULL || jobj == phantom_obj) {
2788 #ifdef ASSERT
2789 ptnode_adr(n->_idx)->dump();
2790 assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
2791 #endif
2792 _compile->record_failure(C2Compiler::retry_no_escape_analysis());
2793 return;
2794 } else {
2795 Node *val = get_map(jobj->idx()); // CheckCastPP node
2796 TypeNode *tn = n->as_Type();
2797 const TypeOopPtr* tinst = igvn->type(val)->isa_oopptr();
2798 assert(tinst != NULL && tinst->is_known_instance() &&
2799 tinst->instance_id() == jobj->idx() , "instance type expected.");
2801 const Type *tn_type = igvn->type(tn);
2802 const TypeOopPtr *tn_t;
2803 if (tn_type->isa_narrowoop()) {
2804 tn_t = tn_type->make_ptr()->isa_oopptr();
2805 } else {
2806 tn_t = tn_type->isa_oopptr();
2807 }
2808 if (tn_t != NULL && tinst->klass()->is_subtype_of(tn_t->klass())) {
2809 if (tn_type->isa_narrowoop()) {
2810 tn_type = tinst->make_narrowoop();
2811 } else {
2812 tn_type = tinst;
2813 }
2814 igvn->hash_delete(tn);
2815 igvn->set_type(tn, tn_type);
2816 tn->set_type(tn_type);
2817 igvn->hash_insert(tn);
2818 record_for_optimizer(n);
2819 } else {
2820 assert(tn_type == TypePtr::NULL_PTR ||
2821 tn_t != NULL && !tinst->klass()->is_subtype_of(tn_t->klass()),
2822 "unexpected type");
2823 continue; // Skip dead path with different type
2824 }
2825 }
2826 } else {
2827 debug_only(n->dump();)
2828 assert(false, "EA: unexpected node");
2829 continue;
2830 }
2831 // push allocation's users on appropriate worklist
2832 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2833 Node *use = n->fast_out(i);
2834 if(use->is_Mem() && use->in(MemNode::Address) == n) {
2835 // Load/store to instance's field
2836 memnode_worklist.append_if_missing(use);
2837 } else if (use->is_MemBar()) {
2838 memnode_worklist.append_if_missing(use);
2839 } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
2840 Node* addp2 = find_second_addp(use, n);
2841 if (addp2 != NULL) {
2842 alloc_worklist.append_if_missing(addp2);
2843 }
2844 alloc_worklist.append_if_missing(use);
2845 } else if (use->is_Phi() ||
2846 use->is_CheckCastPP() ||
2847 use->is_EncodeNarrowPtr() ||
2848 use->is_DecodeNarrowPtr() ||
2849 (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
2850 alloc_worklist.append_if_missing(use);
2851 #ifdef ASSERT
2852 } else if (use->is_Mem()) {
2853 assert(use->in(MemNode::Address) != n, "EA: missing allocation reference path");
2854 } else if (use->is_MergeMem()) {
2855 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
2856 } else if (use->is_SafePoint()) {
2857 // Look for MergeMem nodes for calls which reference unique allocation
2858 // (through CheckCastPP nodes) even for debug info.
2859 Node* m = use->in(TypeFunc::Memory);
2860 if (m->is_MergeMem()) {
2861 assert(_mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
2862 }
2863 } else {
2864 uint op = use->Opcode();
2865 if (!(op == Op_CmpP || op == Op_Conv2B ||
2866 op == Op_CastP2X || op == Op_StoreCM ||
2867 op == Op_FastLock || op == Op_AryEq || op == Op_StrComp ||
2868 op == Op_StrEquals || op == Op_StrIndexOf)) {
2869 n->dump();
2870 use->dump();
2871 assert(false, "EA: missing allocation reference path");
2872 }
2873 #endif
2874 }
2875 }
2877 }
2878 // New alias types were created in split_AddP().
2879 uint new_index_end = (uint) _compile->num_alias_types();
2880 assert(unique_old == _compile->unique(), "there should be no new ideal nodes after Phase 1");
2882 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
2883 // compute new values for Memory inputs (the Memory inputs are not
2884 // actually updated until phase 4.)
2885 if (memnode_worklist.length() == 0)
2886 return; // nothing to do
2887 while (memnode_worklist.length() != 0) {
2888 Node *n = memnode_worklist.pop();
2889 if (visited.test_set(n->_idx))
2890 continue;
2891 if (n->is_Phi() || n->is_ClearArray()) {
2892 // we don't need to do anything, but the users must be pushed
2893 } else if (n->is_MemBar()) { // Initialize, MemBar nodes
2894 // we don't need to do anything, but the users must be pushed
2895 n = n->as_MemBar()->proj_out(TypeFunc::Memory);
2896 if (n == NULL)
2897 continue;
2898 } else {
2899 assert(n->is_Mem(), "memory node required.");
2900 Node *addr = n->in(MemNode::Address);
2901 const Type *addr_t = igvn->type(addr);
2902 if (addr_t == Type::TOP)
2903 continue;
2904 assert (addr_t->isa_ptr() != NULL, "pointer type required.");
2905 int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
2906 assert ((uint)alias_idx < new_index_end, "wrong alias index");
2907 Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis);
2908 if (_compile->failing()) {
2909 return;
2910 }
2911 if (mem != n->in(MemNode::Memory)) {
2912 // We delay the memory edge update since we need old one in
2913 // MergeMem code below when instances memory slices are separated.
2914 set_map(n, mem);
2915 }
2916 if (n->is_Load()) {
2917 continue; // don't push users
2918 } else if (n->is_LoadStore()) {
2919 // get the memory projection
2920 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2921 Node *use = n->fast_out(i);
2922 if (use->Opcode() == Op_SCMemProj) {
2923 n = use;
2924 break;
2925 }
2926 }
2927 assert(n->Opcode() == Op_SCMemProj, "memory projection required");
2928 }
2929 }
2930 // push user on appropriate worklist
2931 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2932 Node *use = n->fast_out(i);
2933 if (use->is_Phi() || use->is_ClearArray()) {
2934 memnode_worklist.append_if_missing(use);
2935 } else if(use->is_Mem() && use->in(MemNode::Memory) == n) {
2936 if (use->Opcode() == Op_StoreCM) // Ignore cardmark stores
2937 continue;
2938 memnode_worklist.append_if_missing(use);
2939 } else if (use->is_MemBar()) {
2940 memnode_worklist.append_if_missing(use);
2941 #ifdef ASSERT
2942 } else if(use->is_Mem()) {
2943 assert(use->in(MemNode::Memory) != n, "EA: missing memory path");
2944 } else if (use->is_MergeMem()) {
2945 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
2946 } else {
2947 uint op = use->Opcode();
2948 if (!(op == Op_StoreCM ||
2949 (op == Op_CallLeaf && use->as_CallLeaf()->_name != NULL &&
2950 strcmp(use->as_CallLeaf()->_name, "g1_wb_pre") == 0) ||
2951 op == Op_AryEq || op == Op_StrComp ||
2952 op == Op_StrEquals || op == Op_StrIndexOf)) {
2953 n->dump();
2954 use->dump();
2955 assert(false, "EA: missing memory path");
2956 }
2957 #endif
2958 }
2959 }
2960 }
2962 // Phase 3: Process MergeMem nodes from mergemem_worklist.
2963 // Walk each memory slice moving the first node encountered of each
2964 // instance type to the the input corresponding to its alias index.
2965 uint length = _mergemem_worklist.length();
2966 for( uint next = 0; next < length; ++next ) {
2967 MergeMemNode* nmm = _mergemem_worklist.at(next);
2968 assert(!visited.test_set(nmm->_idx), "should not be visited before");
2969 // Note: we don't want to use MergeMemStream here because we only want to
2970 // scan inputs which exist at the start, not ones we add during processing.
2971 // Note 2: MergeMem may already contains instance memory slices added
2972 // during find_inst_mem() call when memory nodes were processed above.
2973 igvn->hash_delete(nmm);
2974 uint nslices = nmm->req();
2975 for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) {
2976 Node* mem = nmm->in(i);
2977 Node* cur = NULL;
2978 if (mem == NULL || mem->is_top())
2979 continue;
2980 // First, update mergemem by moving memory nodes to corresponding slices
2981 // if their type became more precise since this mergemem was created.
2982 while (mem->is_Mem()) {
2983 const Type *at = igvn->type(mem->in(MemNode::Address));
2984 if (at != Type::TOP) {
2985 assert (at->isa_ptr() != NULL, "pointer type required.");
2986 uint idx = (uint)_compile->get_alias_index(at->is_ptr());
2987 if (idx == i) {
2988 if (cur == NULL)
2989 cur = mem;
2990 } else {
2991 if (idx >= nmm->req() || nmm->is_empty_memory(nmm->in(idx))) {
2992 nmm->set_memory_at(idx, mem);
2993 }
2994 }
2995 }
2996 mem = mem->in(MemNode::Memory);
2997 }
2998 nmm->set_memory_at(i, (cur != NULL) ? cur : mem);
2999 // Find any instance of the current type if we haven't encountered
3000 // already a memory slice of the instance along the memory chain.
3001 for (uint ni = new_index_start; ni < new_index_end; ni++) {
3002 if((uint)_compile->get_general_index(ni) == i) {
3003 Node *m = (ni >= nmm->req()) ? nmm->empty_memory() : nmm->in(ni);
3004 if (nmm->is_empty_memory(m)) {
3005 Node* result = find_inst_mem(mem, ni, orig_phis);
3006 if (_compile->failing()) {
3007 return;
3008 }
3009 nmm->set_memory_at(ni, result);
3010 }
3011 }
3012 }
3013 }
3014 // Find the rest of instances values
3015 for (uint ni = new_index_start; ni < new_index_end; ni++) {
3016 const TypeOopPtr *tinst = _compile->get_adr_type(ni)->isa_oopptr();
3017 Node* result = step_through_mergemem(nmm, ni, tinst);
3018 if (result == nmm->base_memory()) {
3019 // Didn't find instance memory, search through general slice recursively.
3020 result = nmm->memory_at(_compile->get_general_index(ni));
3021 result = find_inst_mem(result, ni, orig_phis);
3022 if (_compile->failing()) {
3023 return;
3024 }
3025 nmm->set_memory_at(ni, result);
3026 }
3027 }
3028 igvn->hash_insert(nmm);
3029 record_for_optimizer(nmm);
3030 }
3032 // Phase 4: Update the inputs of non-instance memory Phis and
3033 // the Memory input of memnodes
3034 // First update the inputs of any non-instance Phi's from
3035 // which we split out an instance Phi. Note we don't have
3036 // to recursively process Phi's encounted on the input memory
3037 // chains as is done in split_memory_phi() since they will
3038 // also be processed here.
3039 for (int j = 0; j < orig_phis.length(); j++) {
3040 PhiNode *phi = orig_phis.at(j);
3041 int alias_idx = _compile->get_alias_index(phi->adr_type());
3042 igvn->hash_delete(phi);
3043 for (uint i = 1; i < phi->req(); i++) {
3044 Node *mem = phi->in(i);
3045 Node *new_mem = find_inst_mem(mem, alias_idx, orig_phis);
3046 if (_compile->failing()) {
3047 return;
3048 }
3049 if (mem != new_mem) {
3050 phi->set_req(i, new_mem);
3051 }
3052 }
3053 igvn->hash_insert(phi);
3054 record_for_optimizer(phi);
3055 }
3057 // Update the memory inputs of MemNodes with the value we computed
3058 // in Phase 2 and move stores memory users to corresponding memory slices.
3059 // Disable memory split verification code until the fix for 6984348.
3060 // Currently it produces false negative results since it does not cover all cases.
3061 #if 0 // ifdef ASSERT
3062 visited.Reset();
3063 Node_Stack old_mems(arena, _compile->unique() >> 2);
3064 #endif
3065 for (uint i = 0; i < ideal_nodes.size(); i++) {
3066 Node* n = ideal_nodes.at(i);
3067 Node* nmem = get_map(n->_idx);
3068 assert(nmem != NULL, "sanity");
3069 if (n->is_Mem()) {
3070 #if 0 // ifdef ASSERT
3071 Node* old_mem = n->in(MemNode::Memory);
3072 if (!visited.test_set(old_mem->_idx)) {
3073 old_mems.push(old_mem, old_mem->outcnt());
3074 }
3075 #endif
3076 assert(n->in(MemNode::Memory) != nmem, "sanity");
3077 if (!n->is_Load()) {
3078 // Move memory users of a store first.
3079 move_inst_mem(n, orig_phis);
3080 }
3081 // Now update memory input
3082 igvn->hash_delete(n);
3083 n->set_req(MemNode::Memory, nmem);
3084 igvn->hash_insert(n);
3085 record_for_optimizer(n);
3086 } else {
3087 assert(n->is_Allocate() || n->is_CheckCastPP() ||
3088 n->is_AddP() || n->is_Phi(), "unknown node used for set_map()");
3089 }
3090 }
3091 #if 0 // ifdef ASSERT
3092 // Verify that memory was split correctly
3093 while (old_mems.is_nonempty()) {
3094 Node* old_mem = old_mems.node();
3095 uint old_cnt = old_mems.index();
3096 old_mems.pop();
3097 assert(old_cnt == old_mem->outcnt(), "old mem could be lost");
3098 }
3099 #endif
3100 }
3102 #ifndef PRODUCT
3103 static const char *node_type_names[] = {
3104 "UnknownType",
3105 "JavaObject",
3106 "LocalVar",
3107 "Field",
3108 "Arraycopy"
3109 };
3111 static const char *esc_names[] = {
3112 "UnknownEscape",
3113 "NoEscape",
3114 "ArgEscape",
3115 "GlobalEscape"
3116 };
3118 void PointsToNode::dump(bool print_state) const {
3119 NodeType nt = node_type();
3120 tty->print("%s ", node_type_names[(int) nt]);
3121 if (print_state) {
3122 EscapeState es = escape_state();
3123 EscapeState fields_es = fields_escape_state();
3124 tty->print("%s(%s) ", esc_names[(int)es], esc_names[(int)fields_es]);
3125 if (nt == PointsToNode::JavaObject && !this->scalar_replaceable())
3126 tty->print("NSR");
3127 }
3128 if (is_Field()) {
3129 FieldNode* f = (FieldNode*)this;
3130 tty->print("(");
3131 for (BaseIterator i(f); i.has_next(); i.next()) {
3132 PointsToNode* b = i.get();
3133 tty->print(" %d%s", b->idx(),(b->is_JavaObject() ? "P" : ""));
3134 }
3135 tty->print(" )");
3136 }
3137 tty->print("[");
3138 for (EdgeIterator i(this); i.has_next(); i.next()) {
3139 PointsToNode* e = i.get();
3140 tty->print(" %d%s%s", e->idx(),(e->is_JavaObject() ? "P" : (e->is_Field() ? "F" : "")), e->is_Arraycopy() ? "cp" : "");
3141 }
3142 tty->print(" [");
3143 for (UseIterator i(this); i.has_next(); i.next()) {
3144 PointsToNode* u = i.get();
3145 bool is_base = false;
3146 if (PointsToNode::is_base_use(u)) {
3147 is_base = true;
3148 u = PointsToNode::get_use_node(u)->as_Field();
3149 }
3150 tty->print(" %d%s%s", u->idx(), is_base ? "b" : "", u->is_Arraycopy() ? "cp" : "");
3151 }
3152 tty->print(" ]] ");
3153 if (_node == NULL)
3154 tty->print_cr("<null>");
3155 else
3156 _node->dump();
3157 }
3159 void ConnectionGraph::dump(GrowableArray<PointsToNode*>& ptnodes_worklist) {
3160 bool first = true;
3161 int ptnodes_length = ptnodes_worklist.length();
3162 for (int i = 0; i < ptnodes_length; i++) {
3163 PointsToNode *ptn = ptnodes_worklist.at(i);
3164 if (ptn == NULL || !ptn->is_JavaObject())
3165 continue;
3166 PointsToNode::EscapeState es = ptn->escape_state();
3167 if (ptn->ideal_node()->is_Allocate() && (es == PointsToNode::NoEscape || Verbose)) {
3168 if (first) {
3169 tty->cr();
3170 tty->print("======== Connection graph for ");
3171 _compile->method()->print_short_name();
3172 tty->cr();
3173 first = false;
3174 }
3175 ptn->dump();
3176 // Print all locals and fields which reference this allocation
3177 for (UseIterator j(ptn); j.has_next(); j.next()) {
3178 PointsToNode* use = j.get();
3179 if (use->is_LocalVar()) {
3180 use->dump(Verbose);
3181 } else if (Verbose) {
3182 use->dump();
3183 }
3184 }
3185 tty->cr();
3186 }
3187 }
3188 }
3189 #endif