Mon, 12 Mar 2012 10:46:47 -0700
7147744: CTW: assert(false) failed: infinite EA connection graph build
Summary: rewrote Connection graph construction code in EA to reduce time spent there.
Reviewed-by: never
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 // Populate Connection Graph with PointsTo nodes and create simple
286 // connection graph edges.
287 void ConnectionGraph::add_node_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
288 assert(!_verify, "this method sould not be called for verification");
289 PhaseGVN* igvn = _igvn;
290 uint n_idx = n->_idx;
291 PointsToNode* n_ptn = ptnode_adr(n_idx);
292 if (n_ptn != NULL)
293 return; // No need to redefine PointsTo node during first iteration.
295 if (n->is_Call()) {
296 // Arguments to allocation and locking don't escape.
297 if (n->is_AbstractLock()) {
298 // Put Lock and Unlock nodes on IGVN worklist to process them during
299 // first IGVN optimization when escape information is still available.
300 record_for_optimizer(n);
301 } else if (n->is_Allocate()) {
302 add_call_node(n->as_Call());
303 record_for_optimizer(n);
304 } else {
305 if (n->is_CallStaticJava()) {
306 const char* name = n->as_CallStaticJava()->_name;
307 if (name != NULL && strcmp(name, "uncommon_trap") == 0)
308 return; // Skip uncommon traps
309 }
310 // Don't mark as processed since call's arguments have to be processed.
311 delayed_worklist->push(n);
312 // Check if a call returns an object.
313 if (n->as_Call()->returns_pointer() &&
314 n->as_Call()->proj_out(TypeFunc::Parms) != NULL) {
315 add_call_node(n->as_Call());
316 }
317 }
318 return;
319 }
320 // Put this check here to process call arguments since some call nodes
321 // point to phantom_obj.
322 if (n_ptn == phantom_obj || n_ptn == null_obj)
323 return; // Skip predefined nodes.
325 int opcode = n->Opcode();
326 switch (opcode) {
327 case Op_AddP: {
328 Node* base = get_addp_base(n);
329 PointsToNode* ptn_base = ptnode_adr(base->_idx);
330 // Field nodes are created for all field types. They are used in
331 // adjust_scalar_replaceable_state() and split_unique_types().
332 // Note, non-oop fields will have only base edges in Connection
333 // Graph because such fields are not used for oop loads and stores.
334 int offset = address_offset(n, igvn);
335 add_field(n, PointsToNode::NoEscape, offset);
336 if (ptn_base == NULL) {
337 delayed_worklist->push(n); // Process it later.
338 } else {
339 n_ptn = ptnode_adr(n_idx);
340 add_base(n_ptn->as_Field(), ptn_base);
341 }
342 break;
343 }
344 case Op_CastX2P: {
345 map_ideal_node(n, phantom_obj);
346 break;
347 }
348 case Op_CastPP:
349 case Op_CheckCastPP:
350 case Op_EncodeP:
351 case Op_DecodeN: {
352 add_local_var_and_edge(n, PointsToNode::NoEscape,
353 n->in(1), delayed_worklist);
354 break;
355 }
356 case Op_CMoveP: {
357 add_local_var(n, PointsToNode::NoEscape);
358 // Do not add edges during first iteration because some could be
359 // not defined yet.
360 delayed_worklist->push(n);
361 break;
362 }
363 case Op_ConP:
364 case Op_ConN: {
365 // assume all oop constants globally escape except for null
366 PointsToNode::EscapeState es;
367 if (igvn->type(n) == TypePtr::NULL_PTR ||
368 igvn->type(n) == TypeNarrowOop::NULL_PTR) {
369 es = PointsToNode::NoEscape;
370 } else {
371 es = PointsToNode::GlobalEscape;
372 }
373 add_java_object(n, es);
374 break;
375 }
376 case Op_CreateEx: {
377 // assume that all exception objects globally escape
378 add_java_object(n, PointsToNode::GlobalEscape);
379 break;
380 }
381 case Op_LoadKlass:
382 case Op_LoadNKlass: {
383 // Unknown class is loaded
384 map_ideal_node(n, phantom_obj);
385 break;
386 }
387 case Op_LoadP:
388 case Op_LoadN:
389 case Op_LoadPLocked: {
390 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
391 // ThreadLocal has RawPrt type.
392 const Type* t = igvn->type(n);
393 if (t->make_ptr() != NULL) {
394 Node* adr = n->in(MemNode::Address);
395 #ifdef ASSERT
396 if (!adr->is_AddP()) {
397 assert(igvn->type(adr)->isa_rawptr(), "sanity");
398 } else {
399 assert((ptnode_adr(adr->_idx) == NULL ||
400 ptnode_adr(adr->_idx)->as_Field()->is_oop()), "sanity");
401 }
402 #endif
403 add_local_var_and_edge(n, PointsToNode::NoEscape,
404 adr, delayed_worklist);
405 }
406 break;
407 }
408 case Op_Parm: {
409 map_ideal_node(n, phantom_obj);
410 break;
411 }
412 case Op_PartialSubtypeCheck: {
413 // Produces Null or notNull and is used in only in CmpP so
414 // phantom_obj could be used.
415 map_ideal_node(n, phantom_obj); // Result is unknown
416 break;
417 }
418 case Op_Phi: {
419 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
420 // ThreadLocal has RawPrt type.
421 const Type* t = n->as_Phi()->type();
422 if (t->make_ptr() != NULL) {
423 add_local_var(n, PointsToNode::NoEscape);
424 // Do not add edges during first iteration because some could be
425 // not defined yet.
426 delayed_worklist->push(n);
427 }
428 break;
429 }
430 case Op_Proj: {
431 // we are only interested in the oop result projection from a call
432 if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
433 n->in(0)->as_Call()->returns_pointer()) {
434 add_local_var_and_edge(n, PointsToNode::NoEscape,
435 n->in(0), delayed_worklist);
436 }
437 break;
438 }
439 case Op_Rethrow: // Exception object escapes
440 case Op_Return: {
441 if (n->req() > TypeFunc::Parms &&
442 igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
443 // Treat Return value as LocalVar with GlobalEscape escape state.
444 add_local_var_and_edge(n, PointsToNode::GlobalEscape,
445 n->in(TypeFunc::Parms), delayed_worklist);
446 }
447 break;
448 }
449 case Op_StoreP:
450 case Op_StoreN:
451 case Op_StorePConditional:
452 case Op_CompareAndSwapP:
453 case Op_CompareAndSwapN: {
454 Node* adr = n->in(MemNode::Address);
455 const Type *adr_type = igvn->type(adr);
456 adr_type = adr_type->make_ptr();
457 if (adr_type->isa_oopptr() ||
458 (opcode == Op_StoreP || opcode == Op_StoreN) &&
459 (adr_type == TypeRawPtr::NOTNULL &&
460 adr->in(AddPNode::Address)->is_Proj() &&
461 adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
462 delayed_worklist->push(n); // Process it later.
463 #ifdef ASSERT
464 assert(adr->is_AddP(), "expecting an AddP");
465 if (adr_type == TypeRawPtr::NOTNULL) {
466 // Verify a raw address for a store captured by Initialize node.
467 int offs = (int)igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
468 assert(offs != Type::OffsetBot, "offset must be a constant");
469 }
470 } else {
471 // Ignore copy the displaced header to the BoxNode (OSR compilation).
472 if (adr->is_BoxLock())
473 break;
475 if (!adr->is_AddP()) {
476 n->dump(1);
477 assert(adr->is_AddP(), "expecting an AddP");
478 }
479 // Ignore G1 barrier's stores.
480 if (!UseG1GC || (opcode != Op_StoreP) ||
481 (adr_type != TypeRawPtr::BOTTOM)) {
482 n->dump(1);
483 assert(false, "not G1 barrier raw StoreP");
484 }
485 #endif
486 }
487 break;
488 }
489 case Op_AryEq:
490 case Op_StrComp:
491 case Op_StrEquals:
492 case Op_StrIndexOf: {
493 add_local_var(n, PointsToNode::ArgEscape);
494 delayed_worklist->push(n); // Process it later.
495 break;
496 }
497 case Op_ThreadLocal: {
498 add_java_object(n, PointsToNode::ArgEscape);
499 break;
500 }
501 default:
502 ; // Do nothing for nodes not related to EA.
503 }
504 return;
505 }
507 #ifdef ASSERT
508 #define ELSE_FAIL(name) \
509 /* Should not be called for not pointer type. */ \
510 n->dump(1); \
511 assert(false, name); \
512 break;
513 #else
514 #define ELSE_FAIL(name) \
515 break;
516 #endif
518 // Add final simple edges to graph.
519 void ConnectionGraph::add_final_edges(Node *n) {
520 PointsToNode* n_ptn = ptnode_adr(n->_idx);
521 #ifdef ASSERT
522 if (_verify && n_ptn->is_JavaObject())
523 return; // This method does not change graph for JavaObject.
524 #endif
526 if (n->is_Call()) {
527 process_call_arguments(n->as_Call());
528 return;
529 }
530 assert(n->is_Store() || n->is_LoadStore() ||
531 (n_ptn != NULL) && (n_ptn->ideal_node() != NULL),
532 "node should be registered already");
533 int opcode = n->Opcode();
534 switch (opcode) {
535 case Op_AddP: {
536 Node* base = get_addp_base(n);
537 PointsToNode* ptn_base = ptnode_adr(base->_idx);
538 assert(ptn_base != NULL, "field's base should be registered");
539 add_base(n_ptn->as_Field(), ptn_base);
540 break;
541 }
542 case Op_CastPP:
543 case Op_CheckCastPP:
544 case Op_EncodeP:
545 case Op_DecodeN: {
546 add_local_var_and_edge(n, PointsToNode::NoEscape,
547 n->in(1), NULL);
548 break;
549 }
550 case Op_CMoveP: {
551 for (uint i = CMoveNode::IfFalse; i < n->req(); i++) {
552 Node* in = n->in(i);
553 if (in == NULL)
554 continue; // ignore NULL
555 Node* uncast_in = in->uncast();
556 if (uncast_in->is_top() || uncast_in == n)
557 continue; // ignore top or inputs which go back this node
558 PointsToNode* ptn = ptnode_adr(in->_idx);
559 assert(ptn != NULL, "node should be registered");
560 add_edge(n_ptn, ptn);
561 }
562 break;
563 }
564 case Op_LoadP:
565 case Op_LoadN:
566 case Op_LoadPLocked: {
567 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
568 // ThreadLocal has RawPrt type.
569 const Type* t = _igvn->type(n);
570 if (t->make_ptr() != NULL) {
571 Node* adr = n->in(MemNode::Address);
572 add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
573 break;
574 }
575 ELSE_FAIL("Op_LoadP");
576 }
577 case Op_Phi: {
578 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
579 // ThreadLocal has RawPrt type.
580 const Type* t = n->as_Phi()->type();
581 if (t->make_ptr() != NULL) {
582 for (uint i = 1; i < n->req(); i++) {
583 Node* in = n->in(i);
584 if (in == NULL)
585 continue; // ignore NULL
586 Node* uncast_in = in->uncast();
587 if (uncast_in->is_top() || uncast_in == n)
588 continue; // ignore top or inputs which go back this node
589 PointsToNode* ptn = ptnode_adr(in->_idx);
590 assert(ptn != NULL, "node should be registered");
591 add_edge(n_ptn, ptn);
592 }
593 break;
594 }
595 ELSE_FAIL("Op_Phi");
596 }
597 case Op_Proj: {
598 // we are only interested in the oop result projection from a call
599 if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
600 n->in(0)->as_Call()->returns_pointer()) {
601 add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(0), NULL);
602 break;
603 }
604 ELSE_FAIL("Op_Proj");
605 }
606 case Op_Rethrow: // Exception object escapes
607 case Op_Return: {
608 if (n->req() > TypeFunc::Parms &&
609 _igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
610 // Treat Return value as LocalVar with GlobalEscape escape state.
611 add_local_var_and_edge(n, PointsToNode::GlobalEscape,
612 n->in(TypeFunc::Parms), NULL);
613 break;
614 }
615 ELSE_FAIL("Op_Return");
616 }
617 case Op_StoreP:
618 case Op_StoreN:
619 case Op_StorePConditional:
620 case Op_CompareAndSwapP:
621 case Op_CompareAndSwapN: {
622 Node* adr = n->in(MemNode::Address);
623 const Type *adr_type = _igvn->type(adr);
624 adr_type = adr_type->make_ptr();
625 if (adr_type->isa_oopptr() ||
626 (opcode == Op_StoreP || opcode == Op_StoreN) &&
627 (adr_type == TypeRawPtr::NOTNULL &&
628 adr->in(AddPNode::Address)->is_Proj() &&
629 adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
630 // Point Address to Value
631 PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
632 assert(adr_ptn != NULL &&
633 adr_ptn->as_Field()->is_oop(), "node should be registered");
634 Node *val = n->in(MemNode::ValueIn);
635 PointsToNode* ptn = ptnode_adr(val->_idx);
636 assert(ptn != NULL, "node should be registered");
637 add_edge(adr_ptn, ptn);
638 break;
639 }
640 ELSE_FAIL("Op_StoreP");
641 }
642 case Op_AryEq:
643 case Op_StrComp:
644 case Op_StrEquals:
645 case Op_StrIndexOf: {
646 // char[] arrays passed to string intrinsic do not escape but
647 // they are not scalar replaceable. Adjust escape state for them.
648 // Start from in(2) edge since in(1) is memory edge.
649 for (uint i = 2; i < n->req(); i++) {
650 Node* adr = n->in(i);
651 const Type* at = _igvn->type(adr);
652 if (!adr->is_top() && at->isa_ptr()) {
653 assert(at == Type::TOP || at == TypePtr::NULL_PTR ||
654 at->isa_ptr() != NULL, "expecting a pointer");
655 if (adr->is_AddP()) {
656 adr = get_addp_base(adr);
657 }
658 PointsToNode* ptn = ptnode_adr(adr->_idx);
659 assert(ptn != NULL, "node should be registered");
660 add_edge(n_ptn, ptn);
661 }
662 }
663 break;
664 }
665 default: {
666 // This method should be called only for EA specific nodes which may
667 // miss some edges when they were created.
668 #ifdef ASSERT
669 n->dump(1);
670 #endif
671 guarantee(false, "unknown node");
672 }
673 }
674 return;
675 }
677 void ConnectionGraph::add_call_node(CallNode* call) {
678 assert(call->returns_pointer(), "only for call which returns pointer");
679 uint call_idx = call->_idx;
680 if (call->is_Allocate()) {
681 Node* k = call->in(AllocateNode::KlassNode);
682 const TypeKlassPtr* kt = k->bottom_type()->isa_klassptr();
683 assert(kt != NULL, "TypeKlassPtr required.");
684 ciKlass* cik = kt->klass();
685 PointsToNode::EscapeState es = PointsToNode::NoEscape;
686 bool scalar_replaceable = true;
687 if (call->is_AllocateArray()) {
688 if (!cik->is_array_klass()) { // StressReflectiveCode
689 es = PointsToNode::GlobalEscape;
690 } else {
691 int length = call->in(AllocateNode::ALength)->find_int_con(-1);
692 if (length < 0 || length > EliminateAllocationArraySizeLimit) {
693 // Not scalar replaceable if the length is not constant or too big.
694 scalar_replaceable = false;
695 }
696 }
697 } else { // Allocate instance
698 if (cik->is_subclass_of(_compile->env()->Thread_klass()) ||
699 !cik->is_instance_klass() || // StressReflectiveCode
700 cik->as_instance_klass()->has_finalizer()) {
701 es = PointsToNode::GlobalEscape;
702 }
703 }
704 add_java_object(call, es);
705 PointsToNode* ptn = ptnode_adr(call_idx);
706 if (!scalar_replaceable && ptn->scalar_replaceable()) {
707 ptn->set_scalar_replaceable(false);
708 }
709 } else if (call->is_CallStaticJava()) {
710 // Call nodes could be different types:
711 //
712 // 1. CallDynamicJavaNode (what happened during call is unknown):
713 //
714 // - mapped to GlobalEscape JavaObject node if oop is returned;
715 //
716 // - all oop arguments are escaping globally;
717 //
718 // 2. CallStaticJavaNode (execute bytecode analysis if possible):
719 //
720 // - the same as CallDynamicJavaNode if can't do bytecode analysis;
721 //
722 // - mapped to GlobalEscape JavaObject node if unknown oop is returned;
723 // - mapped to NoEscape JavaObject node if non-escaping object allocated
724 // during call is returned;
725 // - mapped to ArgEscape LocalVar node pointed to object arguments
726 // which are returned and does not escape during call;
727 //
728 // - oop arguments escaping status is defined by bytecode analysis;
729 //
730 // For a static call, we know exactly what method is being called.
731 // Use bytecode estimator to record whether the call's return value escapes.
732 ciMethod* meth = call->as_CallJava()->method();
733 if (meth == NULL) {
734 const char* name = call->as_CallStaticJava()->_name;
735 assert(strncmp(name, "_multianewarray", 15) == 0, "TODO: add failed case check");
736 // Returns a newly allocated unescaped object.
737 add_java_object(call, PointsToNode::NoEscape);
738 ptnode_adr(call_idx)->set_scalar_replaceable(false);
739 } else {
740 BCEscapeAnalyzer* call_analyzer = meth->get_bcea();
741 call_analyzer->copy_dependencies(_compile->dependencies());
742 if (call_analyzer->is_return_allocated()) {
743 // Returns a newly allocated unescaped object, simply
744 // update dependency information.
745 // Mark it as NoEscape so that objects referenced by
746 // it's fields will be marked as NoEscape at least.
747 add_java_object(call, PointsToNode::NoEscape);
748 ptnode_adr(call_idx)->set_scalar_replaceable(false);
749 } else {
750 // Determine whether any arguments are returned.
751 const TypeTuple* d = call->tf()->domain();
752 bool ret_arg = false;
753 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
754 if (d->field_at(i)->isa_ptr() != NULL &&
755 call_analyzer->is_arg_returned(i - TypeFunc::Parms)) {
756 ret_arg = true;
757 break;
758 }
759 }
760 if (ret_arg) {
761 add_local_var(call, PointsToNode::ArgEscape);
762 } else {
763 // Returns unknown object.
764 map_ideal_node(call, phantom_obj);
765 }
766 }
767 }
768 } else {
769 // An other type of call, assume the worst case:
770 // returned value is unknown and globally escapes.
771 assert(call->Opcode() == Op_CallDynamicJava, "add failed case check");
772 map_ideal_node(call, phantom_obj);
773 }
774 }
776 void ConnectionGraph::process_call_arguments(CallNode *call) {
777 bool is_arraycopy = false;
778 switch (call->Opcode()) {
779 #ifdef ASSERT
780 case Op_Allocate:
781 case Op_AllocateArray:
782 case Op_Lock:
783 case Op_Unlock:
784 assert(false, "should be done already");
785 break;
786 #endif
787 case Op_CallLeafNoFP:
788 is_arraycopy = (call->as_CallLeaf()->_name != NULL &&
789 strstr(call->as_CallLeaf()->_name, "arraycopy") != 0);
790 // fall through
791 case Op_CallLeaf: {
792 // Stub calls, objects do not escape but they are not scale replaceable.
793 // Adjust escape state for outgoing arguments.
794 const TypeTuple * d = call->tf()->domain();
795 bool src_has_oops = false;
796 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
797 const Type* at = d->field_at(i);
798 Node *arg = call->in(i);
799 const Type *aat = _igvn->type(arg);
800 if (arg->is_top() || !at->isa_ptr() || !aat->isa_ptr())
801 continue;
802 if (arg->is_AddP()) {
803 //
804 // The inline_native_clone() case when the arraycopy stub is called
805 // after the allocation before Initialize and CheckCastPP nodes.
806 // Or normal arraycopy for object arrays case.
807 //
808 // Set AddP's base (Allocate) as not scalar replaceable since
809 // pointer to the base (with offset) is passed as argument.
810 //
811 arg = get_addp_base(arg);
812 }
813 PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
814 assert(arg_ptn != NULL, "should be registered");
815 PointsToNode::EscapeState arg_esc = arg_ptn->escape_state();
816 if (is_arraycopy || arg_esc < PointsToNode::ArgEscape) {
817 assert(aat == Type::TOP || aat == TypePtr::NULL_PTR ||
818 aat->isa_ptr() != NULL, "expecting an Ptr");
819 bool arg_has_oops = aat->isa_oopptr() &&
820 (aat->isa_oopptr()->klass() == NULL || aat->isa_instptr() ||
821 (aat->isa_aryptr() && aat->isa_aryptr()->klass()->is_obj_array_klass()));
822 if (i == TypeFunc::Parms) {
823 src_has_oops = arg_has_oops;
824 }
825 //
826 // src or dst could be j.l.Object when other is basic type array:
827 //
828 // arraycopy(char[],0,Object*,0,size);
829 // arraycopy(Object*,0,char[],0,size);
830 //
831 // Don't add edges in such cases.
832 //
833 bool arg_is_arraycopy_dest = src_has_oops && is_arraycopy &&
834 arg_has_oops && (i > TypeFunc::Parms);
835 #ifdef ASSERT
836 if (!(is_arraycopy ||
837 call->as_CallLeaf()->_name != NULL &&
838 (strcmp(call->as_CallLeaf()->_name, "g1_wb_pre") == 0 ||
839 strcmp(call->as_CallLeaf()->_name, "g1_wb_post") == 0 ))
840 ) {
841 call->dump();
842 assert(false, "EA: unexpected CallLeaf");
843 }
844 #endif
845 // Always process arraycopy's destination object since
846 // we need to add all possible edges to references in
847 // source object.
848 if (arg_esc >= PointsToNode::ArgEscape &&
849 !arg_is_arraycopy_dest) {
850 continue;
851 }
852 set_escape_state(arg_ptn, PointsToNode::ArgEscape);
853 if (arg_is_arraycopy_dest) {
854 Node* src = call->in(TypeFunc::Parms);
855 if (src->is_AddP()) {
856 src = get_addp_base(src);
857 }
858 PointsToNode* src_ptn = ptnode_adr(src->_idx);
859 assert(src_ptn != NULL, "should be registered");
860 if (arg_ptn != src_ptn) {
861 // Special arraycopy edge:
862 // A destination object's field can't have the source object
863 // as base since objects escape states are not related.
864 // Only escape state of destination object's fields affects
865 // escape state of fields in source object.
866 add_arraycopy(call, PointsToNode::ArgEscape, src_ptn, arg_ptn);
867 }
868 }
869 }
870 }
871 break;
872 }
873 case Op_CallStaticJava: {
874 // For a static call, we know exactly what method is being called.
875 // Use bytecode estimator to record the call's escape affects
876 #ifdef ASSERT
877 const char* name = call->as_CallStaticJava()->_name;
878 assert((name == NULL || strcmp(name, "uncommon_trap") != 0), "normal calls only");
879 #endif
880 ciMethod* meth = call->as_CallJava()->method();
881 BCEscapeAnalyzer* call_analyzer = (meth !=NULL) ? meth->get_bcea() : NULL;
882 // fall-through if not a Java method or no analyzer information
883 if (call_analyzer != NULL) {
884 PointsToNode* call_ptn = ptnode_adr(call->_idx);
885 const TypeTuple* d = call->tf()->domain();
886 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
887 const Type* at = d->field_at(i);
888 int k = i - TypeFunc::Parms;
889 Node* arg = call->in(i);
890 PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
891 if (at->isa_ptr() != NULL &&
892 call_analyzer->is_arg_returned(k)) {
893 // The call returns arguments.
894 if (call_ptn != NULL) { // Is call's result used?
895 assert(call_ptn->is_LocalVar(), "node should be registered");
896 assert(arg_ptn != NULL, "node should be registered");
897 add_edge(call_ptn, arg_ptn);
898 }
899 }
900 if (at->isa_oopptr() != NULL &&
901 arg_ptn->escape_state() < PointsToNode::GlobalEscape) {
902 if (!call_analyzer->is_arg_stack(k)) {
903 // The argument global escapes
904 set_escape_state(arg_ptn, PointsToNode::GlobalEscape);
905 } else {
906 set_escape_state(arg_ptn, PointsToNode::ArgEscape);
907 if (!call_analyzer->is_arg_local(k)) {
908 // The argument itself doesn't escape, but any fields might
909 set_fields_escape_state(arg_ptn, PointsToNode::GlobalEscape);
910 }
911 }
912 }
913 }
914 if (call_ptn != NULL && call_ptn->is_LocalVar()) {
915 // The call returns arguments.
916 assert(call_ptn->edge_count() > 0, "sanity");
917 if (!call_analyzer->is_return_local()) {
918 // Returns also unknown object.
919 add_edge(call_ptn, phantom_obj);
920 }
921 }
922 break;
923 }
924 }
925 default: {
926 // Fall-through here if not a Java method or no analyzer information
927 // or some other type of call, assume the worst case: all arguments
928 // globally escape.
929 const TypeTuple* d = call->tf()->domain();
930 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
931 const Type* at = d->field_at(i);
932 if (at->isa_oopptr() != NULL) {
933 Node* arg = call->in(i);
934 if (arg->is_AddP()) {
935 arg = get_addp_base(arg);
936 }
937 assert(ptnode_adr(arg->_idx) != NULL, "should be defined already");
938 set_escape_state(ptnode_adr(arg->_idx), PointsToNode::GlobalEscape);
939 }
940 }
941 }
942 }
943 }
946 // Finish Graph construction.
947 bool ConnectionGraph::complete_connection_graph(
948 GrowableArray<PointsToNode*>& ptnodes_worklist,
949 GrowableArray<JavaObjectNode*>& non_escaped_worklist,
950 GrowableArray<JavaObjectNode*>& java_objects_worklist,
951 GrowableArray<FieldNode*>& oop_fields_worklist) {
952 // Normally only 1-3 passes needed to build Connection Graph depending
953 // on graph complexity. Observed 8 passes in jvm2008 compiler.compiler.
954 // Set limit to 20 to catch situation when something did go wrong and
955 // bailout Escape Analysis.
956 // Also limit build time to 30 sec (60 in debug VM).
957 #define CG_BUILD_ITER_LIMIT 20
958 #ifdef ASSERT
959 #define CG_BUILD_TIME_LIMIT 60.0
960 #else
961 #define CG_BUILD_TIME_LIMIT 30.0
962 #endif
964 // Propagate GlobalEscape and ArgEscape escape states and check that
965 // we still have non-escaping objects. The method pushs on _worklist
966 // Field nodes which reference phantom_object.
967 if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
968 return false; // Nothing to do.
969 }
970 // Now propagate references to all JavaObject nodes.
971 int java_objects_length = java_objects_worklist.length();
972 elapsedTimer time;
973 int new_edges = 1;
974 int iterations = 0;
975 do {
976 while ((new_edges > 0) &&
977 (iterations++ < CG_BUILD_ITER_LIMIT) &&
978 (time.seconds() < CG_BUILD_TIME_LIMIT)) {
979 time.start();
980 new_edges = 0;
981 // Propagate references to phantom_object for nodes pushed on _worklist
982 // by find_non_escaped_objects() and find_field_value().
983 new_edges += add_java_object_edges(phantom_obj, false);
984 for (int next = 0; next < java_objects_length; ++next) {
985 JavaObjectNode* ptn = java_objects_worklist.at(next);
986 new_edges += add_java_object_edges(ptn, true);
987 }
988 if (new_edges > 0) {
989 // Update escape states on each iteration if graph was updated.
990 if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
991 return false; // Nothing to do.
992 }
993 }
994 time.stop();
995 }
996 if ((iterations < CG_BUILD_ITER_LIMIT) &&
997 (time.seconds() < CG_BUILD_TIME_LIMIT)) {
998 time.start();
999 // Find fields which have unknown value.
1000 int fields_length = oop_fields_worklist.length();
1001 for (int next = 0; next < fields_length; next++) {
1002 FieldNode* field = oop_fields_worklist.at(next);
1003 if (field->edge_count() == 0) {
1004 new_edges += find_field_value(field);
1005 // This code may added new edges to phantom_object.
1006 // Need an other cycle to propagate references to phantom_object.
1007 }
1008 }
1009 time.stop();
1010 } else {
1011 new_edges = 0; // Bailout
1012 }
1013 } while (new_edges > 0);
1015 // Bailout if passed limits.
1016 if ((iterations >= CG_BUILD_ITER_LIMIT) ||
1017 (time.seconds() >= CG_BUILD_TIME_LIMIT)) {
1018 Compile* C = _compile;
1019 if (C->log() != NULL) {
1020 C->log()->begin_elem("connectionGraph_bailout reason='reached ");
1021 C->log()->text("%s", (iterations >= CG_BUILD_ITER_LIMIT) ? "iterations" : "time");
1022 C->log()->end_elem(" limit'");
1023 }
1024 assert(false, err_msg("infinite EA connection graph build (%f sec, %d iterations) with %d nodes and worklist size %d",
1025 time.seconds(), iterations, nodes_size(), ptnodes_worklist.length()));
1026 // Possible infinite build_connection_graph loop,
1027 // bailout (no changes to ideal graph were made).
1028 return false;
1029 }
1030 #ifdef ASSERT
1031 if (Verbose && PrintEscapeAnalysis) {
1032 tty->print_cr("EA: %d iterations to build connection graph with %d nodes and worklist size %d",
1033 iterations, nodes_size(), ptnodes_worklist.length());
1034 }
1035 #endif
1037 #undef CG_BUILD_ITER_LIMIT
1038 #undef CG_BUILD_TIME_LIMIT
1040 // Find fields initialized by NULL for non-escaping Allocations.
1041 int non_escaped_length = non_escaped_worklist.length();
1042 for (int next = 0; next < non_escaped_length; next++) {
1043 JavaObjectNode* ptn = non_escaped_worklist.at(next);
1044 PointsToNode::EscapeState es = ptn->escape_state();
1045 assert(es <= PointsToNode::ArgEscape, "sanity");
1046 if (es == PointsToNode::NoEscape) {
1047 if (find_init_values(ptn, null_obj, _igvn) > 0) {
1048 // Adding references to NULL object does not change escape states
1049 // since it does not escape. Also no fields are added to NULL object.
1050 add_java_object_edges(null_obj, false);
1051 }
1052 }
1053 Node* n = ptn->ideal_node();
1054 if (n->is_Allocate()) {
1055 // The object allocated by this Allocate node will never be
1056 // seen by an other thread. Mark it so that when it is
1057 // expanded no MemBarStoreStore is added.
1058 InitializeNode* ini = n->as_Allocate()->initialization();
1059 if (ini != NULL)
1060 ini->set_does_not_escape();
1061 }
1062 }
1063 return true; // Finished graph construction.
1064 }
1066 // Propagate GlobalEscape and ArgEscape escape states to all nodes
1067 // and check that we still have non-escaping java objects.
1068 bool ConnectionGraph::find_non_escaped_objects(GrowableArray<PointsToNode*>& ptnodes_worklist,
1069 GrowableArray<JavaObjectNode*>& non_escaped_worklist) {
1070 GrowableArray<PointsToNode*> escape_worklist;
1071 // First, put all nodes with GlobalEscape and ArgEscape states on worklist.
1072 int ptnodes_length = ptnodes_worklist.length();
1073 for (int next = 0; next < ptnodes_length; ++next) {
1074 PointsToNode* ptn = ptnodes_worklist.at(next);
1075 if (ptn->escape_state() >= PointsToNode::ArgEscape ||
1076 ptn->fields_escape_state() >= PointsToNode::ArgEscape) {
1077 escape_worklist.push(ptn);
1078 }
1079 }
1080 // Set escape states to referenced nodes (edges list).
1081 while (escape_worklist.length() > 0) {
1082 PointsToNode* ptn = escape_worklist.pop();
1083 PointsToNode::EscapeState es = ptn->escape_state();
1084 PointsToNode::EscapeState field_es = ptn->fields_escape_state();
1085 if (ptn->is_Field() && ptn->as_Field()->is_oop() &&
1086 es >= PointsToNode::ArgEscape) {
1087 // GlobalEscape or ArgEscape state of field means it has unknown value.
1088 if (add_edge(ptn, phantom_obj)) {
1089 // New edge was added
1090 add_field_uses_to_worklist(ptn->as_Field());
1091 }
1092 }
1093 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1094 PointsToNode* e = i.get();
1095 if (e->is_Arraycopy()) {
1096 assert(ptn->arraycopy_dst(), "sanity");
1097 // Propagate only fields escape state through arraycopy edge.
1098 if (e->fields_escape_state() < field_es) {
1099 set_fields_escape_state(e, field_es);
1100 escape_worklist.push(e);
1101 }
1102 } else if (es >= field_es) {
1103 // fields_escape_state is also set to 'es' if it is less than 'es'.
1104 if (e->escape_state() < es) {
1105 set_escape_state(e, es);
1106 escape_worklist.push(e);
1107 }
1108 } else {
1109 // Propagate field escape state.
1110 bool es_changed = false;
1111 if (e->fields_escape_state() < field_es) {
1112 set_fields_escape_state(e, field_es);
1113 es_changed = true;
1114 }
1115 if ((e->escape_state() < field_es) &&
1116 e->is_Field() && ptn->is_JavaObject() &&
1117 e->as_Field()->is_oop()) {
1118 // Change escape state of referenced fileds.
1119 set_escape_state(e, field_es);
1120 es_changed = true;;
1121 } else if (e->escape_state() < es) {
1122 set_escape_state(e, es);
1123 es_changed = true;;
1124 }
1125 if (es_changed) {
1126 escape_worklist.push(e);
1127 }
1128 }
1129 }
1130 }
1131 // Remove escaped objects from non_escaped list.
1132 for (int next = non_escaped_worklist.length()-1; next >= 0 ; --next) {
1133 JavaObjectNode* ptn = non_escaped_worklist.at(next);
1134 if (ptn->escape_state() >= PointsToNode::GlobalEscape) {
1135 non_escaped_worklist.delete_at(next);
1136 }
1137 if (ptn->escape_state() == PointsToNode::NoEscape) {
1138 // Find fields in non-escaped allocations which have unknown value.
1139 find_init_values(ptn, phantom_obj, NULL);
1140 }
1141 }
1142 return (non_escaped_worklist.length() > 0);
1143 }
1145 // Add all references to JavaObject node by walking over all uses.
1146 int ConnectionGraph::add_java_object_edges(JavaObjectNode* jobj, bool populate_worklist) {
1147 int new_edges = 0;
1148 if (populate_worklist) {
1149 // Populate _worklist by uses of jobj's uses.
1150 for (UseIterator i(jobj); i.has_next(); i.next()) {
1151 PointsToNode* use = i.get();
1152 if (use->is_Arraycopy())
1153 continue;
1154 add_uses_to_worklist(use);
1155 if (use->is_Field() && use->as_Field()->is_oop()) {
1156 // Put on worklist all field's uses (loads) and
1157 // related field nodes (same base and offset).
1158 add_field_uses_to_worklist(use->as_Field());
1159 }
1160 }
1161 }
1162 while(_worklist.length() > 0) {
1163 PointsToNode* use = _worklist.pop();
1164 if (PointsToNode::is_base_use(use)) {
1165 // Add reference from jobj to field and from field to jobj (field's base).
1166 use = PointsToNode::get_use_node(use)->as_Field();
1167 if (add_base(use->as_Field(), jobj)) {
1168 new_edges++;
1169 }
1170 continue;
1171 }
1172 assert(!use->is_JavaObject(), "sanity");
1173 if (use->is_Arraycopy()) {
1174 if (jobj == null_obj) // NULL object does not have field edges
1175 continue;
1176 // Added edge from Arraycopy node to arraycopy's source java object
1177 if (add_edge(use, jobj)) {
1178 jobj->set_arraycopy_src();
1179 new_edges++;
1180 }
1181 // and stop here.
1182 continue;
1183 }
1184 if (!add_edge(use, jobj))
1185 continue; // No new edge added, there was such edge already.
1186 new_edges++;
1187 if (use->is_LocalVar()) {
1188 add_uses_to_worklist(use);
1189 if (use->arraycopy_dst()) {
1190 for (EdgeIterator i(use); i.has_next(); i.next()) {
1191 PointsToNode* e = i.get();
1192 if (e->is_Arraycopy()) {
1193 if (jobj == null_obj) // NULL object does not have field edges
1194 continue;
1195 // Add edge from arraycopy's destination java object to Arraycopy node.
1196 if (add_edge(jobj, e)) {
1197 new_edges++;
1198 jobj->set_arraycopy_dst();
1199 }
1200 }
1201 }
1202 }
1203 } else {
1204 // Added new edge to stored in field values.
1205 // Put on worklist all field's uses (loads) and
1206 // related field nodes (same base and offset).
1207 add_field_uses_to_worklist(use->as_Field());
1208 }
1209 }
1210 return new_edges;
1211 }
1213 // Put on worklist all related field nodes.
1214 void ConnectionGraph::add_field_uses_to_worklist(FieldNode* field) {
1215 assert(field->is_oop(), "sanity");
1216 int offset = field->offset();
1217 add_uses_to_worklist(field);
1218 // Loop over all bases of this field and push on worklist Field nodes
1219 // with the same offset and base (since they may reference the same field).
1220 for (BaseIterator i(field); i.has_next(); i.next()) {
1221 PointsToNode* base = i.get();
1222 add_fields_to_worklist(field, base);
1223 // Check if the base was source object of arraycopy and go over arraycopy's
1224 // destination objects since values stored to a field of source object are
1225 // accessable by uses (loads) of fields of destination objects.
1226 if (base->arraycopy_src()) {
1227 for (UseIterator j(base); j.has_next(); j.next()) {
1228 PointsToNode* arycp = j.get();
1229 if (arycp->is_Arraycopy()) {
1230 for (UseIterator k(arycp); k.has_next(); k.next()) {
1231 PointsToNode* abase = k.get();
1232 if (abase->arraycopy_dst() && abase != base) {
1233 // Look for the same arracopy reference.
1234 add_fields_to_worklist(field, abase);
1235 }
1236 }
1237 }
1238 }
1239 }
1240 }
1241 }
1243 // Put on worklist all related field nodes.
1244 void ConnectionGraph::add_fields_to_worklist(FieldNode* field, PointsToNode* base) {
1245 int offset = field->offset();
1246 if (base->is_LocalVar()) {
1247 for (UseIterator j(base); j.has_next(); j.next()) {
1248 PointsToNode* f = j.get();
1249 if (PointsToNode::is_base_use(f)) { // Field
1250 f = PointsToNode::get_use_node(f);
1251 if (f == field || !f->as_Field()->is_oop())
1252 continue;
1253 int offs = f->as_Field()->offset();
1254 if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1255 add_to_worklist(f);
1256 }
1257 }
1258 }
1259 } else {
1260 assert(base->is_JavaObject(), "sanity");
1261 if (// Skip phantom_object since it is only used to indicate that
1262 // this field's content globally escapes.
1263 (base != phantom_obj) &&
1264 // NULL object node does not have fields.
1265 (base != null_obj)) {
1266 for (EdgeIterator i(base); i.has_next(); i.next()) {
1267 PointsToNode* f = i.get();
1268 // Skip arraycopy edge since store to destination object field
1269 // does not update value in source object field.
1270 if (f->is_Arraycopy()) {
1271 assert(base->arraycopy_dst(), "sanity");
1272 continue;
1273 }
1274 if (f == field || !f->as_Field()->is_oop())
1275 continue;
1276 int offs = f->as_Field()->offset();
1277 if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1278 add_to_worklist(f);
1279 }
1280 }
1281 }
1282 }
1283 }
1285 // Find fields which have unknown value.
1286 int ConnectionGraph::find_field_value(FieldNode* field) {
1287 // Escaped fields should have init value already.
1288 assert(field->escape_state() == PointsToNode::NoEscape, "sanity");
1289 int new_edges = 0;
1290 for (BaseIterator i(field); i.has_next(); i.next()) {
1291 PointsToNode* base = i.get();
1292 if (base->is_JavaObject()) {
1293 // Skip Allocate's fields which will be processed later.
1294 if (base->ideal_node()->is_Allocate())
1295 return 0;
1296 assert(base == null_obj, "only NULL ptr base expected here");
1297 }
1298 }
1299 if (add_edge(field, phantom_obj)) {
1300 // New edge was added
1301 new_edges++;
1302 add_field_uses_to_worklist(field);
1303 }
1304 return new_edges;
1305 }
1307 // Find fields initializing values for allocations.
1308 int ConnectionGraph::find_init_values(JavaObjectNode* pta, PointsToNode* init_val, PhaseTransform* phase) {
1309 assert(pta->escape_state() == PointsToNode::NoEscape, "Not escaped Allocate nodes only");
1310 int new_edges = 0;
1311 Node* alloc = pta->ideal_node();
1312 if (init_val == phantom_obj) {
1313 // Do nothing for Allocate nodes since its fields values are "known".
1314 if (alloc->is_Allocate())
1315 return 0;
1316 assert(alloc->as_CallStaticJava(), "sanity");
1317 #ifdef ASSERT
1318 if (alloc->as_CallStaticJava()->method() == NULL) {
1319 const char* name = alloc->as_CallStaticJava()->_name;
1320 assert(strncmp(name, "_multianewarray", 15) == 0, "sanity");
1321 }
1322 #endif
1323 // Non-escaped allocation returned from Java or runtime call have
1324 // unknown values in fields.
1325 for (EdgeIterator i(pta); i.has_next(); i.next()) {
1326 PointsToNode* ptn = i.get();
1327 if (ptn->is_Field() && ptn->as_Field()->is_oop()) {
1328 if (add_edge(ptn, phantom_obj)) {
1329 // New edge was added
1330 new_edges++;
1331 add_field_uses_to_worklist(ptn->as_Field());
1332 }
1333 }
1334 }
1335 return new_edges;
1336 }
1337 assert(init_val == null_obj, "sanity");
1338 // Do nothing for Call nodes since its fields values are unknown.
1339 if (!alloc->is_Allocate())
1340 return 0;
1342 InitializeNode* ini = alloc->as_Allocate()->initialization();
1343 Compile* C = _compile;
1344 bool visited_bottom_offset = false;
1345 GrowableArray<int> offsets_worklist;
1347 // Check if an oop field's initializing value is recorded and add
1348 // a corresponding NULL if field's value if it is not recorded.
1349 // Connection Graph does not record a default initialization by NULL
1350 // captured by Initialize node.
1351 //
1352 for (EdgeIterator i(pta); i.has_next(); i.next()) {
1353 PointsToNode* ptn = i.get(); // Field (AddP)
1354 if (!ptn->is_Field() || !ptn->as_Field()->is_oop())
1355 continue; // Not oop field
1356 int offset = ptn->as_Field()->offset();
1357 if (offset == Type::OffsetBot) {
1358 if (!visited_bottom_offset) {
1359 // OffsetBot is used to reference array's element,
1360 // always add reference to NULL to all Field nodes since we don't
1361 // known which element is referenced.
1362 if (add_edge(ptn, null_obj)) {
1363 // New edge was added
1364 new_edges++;
1365 add_field_uses_to_worklist(ptn->as_Field());
1366 visited_bottom_offset = true;
1367 }
1368 }
1369 } else {
1370 // Check only oop fields.
1371 const Type* adr_type = ptn->ideal_node()->as_AddP()->bottom_type();
1372 if (adr_type->isa_rawptr()) {
1373 #ifdef ASSERT
1374 // Raw pointers are used for initializing stores so skip it
1375 // since it should be recorded already
1376 Node* base = get_addp_base(ptn->ideal_node());
1377 assert(adr_type->isa_rawptr() && base->is_Proj() &&
1378 (base->in(0) == alloc),"unexpected pointer type");
1379 #endif
1380 continue;
1381 }
1382 if (!offsets_worklist.contains(offset)) {
1383 offsets_worklist.append(offset);
1384 Node* value = NULL;
1385 if (ini != NULL) {
1386 BasicType ft = UseCompressedOops ? T_NARROWOOP : T_OBJECT;
1387 Node* store = ini->find_captured_store(offset, type2aelembytes(ft), phase);
1388 if (store != NULL && store->is_Store()) {
1389 value = store->in(MemNode::ValueIn);
1390 } else {
1391 // There could be initializing stores which follow allocation.
1392 // For example, a volatile field store is not collected
1393 // by Initialize node.
1394 //
1395 // Need to check for dependent loads to separate such stores from
1396 // stores which follow loads. For now, add initial value NULL so
1397 // that compare pointers optimization works correctly.
1398 }
1399 }
1400 if (value == NULL) {
1401 // A field's initializing value was not recorded. Add NULL.
1402 if (add_edge(ptn, null_obj)) {
1403 // New edge was added
1404 new_edges++;
1405 add_field_uses_to_worklist(ptn->as_Field());
1406 }
1407 }
1408 }
1409 }
1410 }
1411 return new_edges;
1412 }
1414 // Adjust scalar_replaceable state after Connection Graph is built.
1415 void ConnectionGraph::adjust_scalar_replaceable_state(JavaObjectNode* jobj) {
1416 // Search for non-escaping objects which are not scalar replaceable
1417 // and mark them to propagate the state to referenced objects.
1419 // 1. An object is not scalar replaceable if the field into which it is
1420 // stored has unknown offset (stored into unknown element of an array).
1421 //
1422 for (UseIterator i(jobj); i.has_next(); i.next()) {
1423 PointsToNode* use = i.get();
1424 assert(!use->is_Arraycopy(), "sanity");
1425 if (use->is_Field()) {
1426 FieldNode* field = use->as_Field();
1427 assert(field->is_oop() && field->scalar_replaceable() &&
1428 field->fields_escape_state() == PointsToNode::NoEscape, "sanity");
1429 if (field->offset() == Type::OffsetBot) {
1430 jobj->set_scalar_replaceable(false);
1431 return;
1432 }
1433 }
1434 assert(use->is_Field() || use->is_LocalVar(), "sanity");
1435 // 2. An object is not scalar replaceable if it is merged with other objects.
1436 for (EdgeIterator j(use); j.has_next(); j.next()) {
1437 PointsToNode* ptn = j.get();
1438 if (ptn->is_JavaObject() && ptn != jobj) {
1439 // Mark all objects.
1440 jobj->set_scalar_replaceable(false);
1441 ptn->set_scalar_replaceable(false);
1442 }
1443 }
1444 if (!jobj->scalar_replaceable()) {
1445 return;
1446 }
1447 }
1449 for (EdgeIterator j(jobj); j.has_next(); j.next()) {
1450 // Non-escaping object node should point only to field nodes.
1451 FieldNode* field = j.get()->as_Field();
1452 int offset = field->as_Field()->offset();
1454 // 3. An object is not scalar replaceable if it has a field with unknown
1455 // offset (array's element is accessed in loop).
1456 if (offset == Type::OffsetBot) {
1457 jobj->set_scalar_replaceable(false);
1458 return;
1459 }
1460 // 4. Currently an object is not scalar replaceable if a LoadStore node
1461 // access its field since the field value is unknown after it.
1462 //
1463 Node* n = field->ideal_node();
1464 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1465 if (n->fast_out(i)->is_LoadStore()) {
1466 jobj->set_scalar_replaceable(false);
1467 return;
1468 }
1469 }
1471 // 5. Or the address may point to more then one object. This may produce
1472 // the false positive result (set not scalar replaceable)
1473 // since the flow-insensitive escape analysis can't separate
1474 // the case when stores overwrite the field's value from the case
1475 // when stores happened on different control branches.
1476 //
1477 // Note: it will disable scalar replacement in some cases:
1478 //
1479 // Point p[] = new Point[1];
1480 // p[0] = new Point(); // Will be not scalar replaced
1481 //
1482 // but it will save us from incorrect optimizations in next cases:
1483 //
1484 // Point p[] = new Point[1];
1485 // if ( x ) p[0] = new Point(); // Will be not scalar replaced
1486 //
1487 if (field->base_count() > 1) {
1488 for (BaseIterator i(field); i.has_next(); i.next()) {
1489 PointsToNode* base = i.get();
1490 // Don't take into account LocalVar nodes which
1491 // may point to only one object which should be also
1492 // this field's base by now.
1493 if (base->is_JavaObject() && base != jobj) {
1494 // Mark all bases.
1495 jobj->set_scalar_replaceable(false);
1496 base->set_scalar_replaceable(false);
1497 }
1498 }
1499 }
1500 }
1501 }
1503 #ifdef ASSERT
1504 void ConnectionGraph::verify_connection_graph(
1505 GrowableArray<PointsToNode*>& ptnodes_worklist,
1506 GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1507 GrowableArray<JavaObjectNode*>& java_objects_worklist,
1508 GrowableArray<Node*>& addp_worklist) {
1509 // Verify that graph is complete - no new edges could be added.
1510 int java_objects_length = java_objects_worklist.length();
1511 int non_escaped_length = non_escaped_worklist.length();
1512 int new_edges = 0;
1513 for (int next = 0; next < java_objects_length; ++next) {
1514 JavaObjectNode* ptn = java_objects_worklist.at(next);
1515 new_edges += add_java_object_edges(ptn, true);
1516 }
1517 assert(new_edges == 0, "graph was not complete");
1518 // Verify that escape state is final.
1519 int length = non_escaped_worklist.length();
1520 find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist);
1521 assert((non_escaped_length == non_escaped_worklist.length()) &&
1522 (non_escaped_length == length) &&
1523 (_worklist.length() == 0), "escape state was not final");
1525 // Verify fields information.
1526 int addp_length = addp_worklist.length();
1527 for (int next = 0; next < addp_length; ++next ) {
1528 Node* n = addp_worklist.at(next);
1529 FieldNode* field = ptnode_adr(n->_idx)->as_Field();
1530 if (field->is_oop()) {
1531 // Verify that field has all bases
1532 Node* base = get_addp_base(n);
1533 PointsToNode* ptn = ptnode_adr(base->_idx);
1534 if (ptn->is_JavaObject()) {
1535 assert(field->has_base(ptn->as_JavaObject()), "sanity");
1536 } else {
1537 assert(ptn->is_LocalVar(), "sanity");
1538 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1539 PointsToNode* e = i.get();
1540 if (e->is_JavaObject()) {
1541 assert(field->has_base(e->as_JavaObject()), "sanity");
1542 }
1543 }
1544 }
1545 // Verify that all fields have initializing values.
1546 if (field->edge_count() == 0) {
1547 field->dump();
1548 assert(field->edge_count() > 0, "sanity");
1549 }
1550 }
1551 }
1552 }
1553 #endif
1555 // Optimize ideal graph.
1556 void ConnectionGraph::optimize_ideal_graph(GrowableArray<Node*>& ptr_cmp_worklist,
1557 GrowableArray<Node*>& storestore_worklist) {
1558 Compile* C = _compile;
1559 PhaseIterGVN* igvn = _igvn;
1560 if (EliminateLocks) {
1561 // Mark locks before changing ideal graph.
1562 int cnt = C->macro_count();
1563 for( int i=0; i < cnt; i++ ) {
1564 Node *n = C->macro_node(i);
1565 if (n->is_AbstractLock()) { // Lock and Unlock nodes
1566 AbstractLockNode* alock = n->as_AbstractLock();
1567 if (!alock->is_non_esc_obj()) {
1568 if (not_global_escape(alock->obj_node())) {
1569 assert(!alock->is_eliminated() || alock->is_coarsened(), "sanity");
1570 // The lock could be marked eliminated by lock coarsening
1571 // code during first IGVN before EA. Replace coarsened flag
1572 // to eliminate all associated locks/unlocks.
1573 alock->set_non_esc_obj();
1574 }
1575 }
1576 }
1577 }
1578 }
1580 if (OptimizePtrCompare) {
1581 // Add ConI(#CC_GT) and ConI(#CC_EQ).
1582 _pcmp_neq = igvn->makecon(TypeInt::CC_GT);
1583 _pcmp_eq = igvn->makecon(TypeInt::CC_EQ);
1584 // Optimize objects compare.
1585 while (ptr_cmp_worklist.length() != 0) {
1586 Node *n = ptr_cmp_worklist.pop();
1587 Node *res = optimize_ptr_compare(n);
1588 if (res != NULL) {
1589 #ifndef PRODUCT
1590 if (PrintOptimizePtrCompare) {
1591 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"));
1592 if (Verbose) {
1593 n->dump(1);
1594 }
1595 }
1596 #endif
1597 igvn->replace_node(n, res);
1598 }
1599 }
1600 // cleanup
1601 if (_pcmp_neq->outcnt() == 0)
1602 igvn->hash_delete(_pcmp_neq);
1603 if (_pcmp_eq->outcnt() == 0)
1604 igvn->hash_delete(_pcmp_eq);
1605 }
1607 // For MemBarStoreStore nodes added in library_call.cpp, check
1608 // escape status of associated AllocateNode and optimize out
1609 // MemBarStoreStore node if the allocated object never escapes.
1610 while (storestore_worklist.length() != 0) {
1611 Node *n = storestore_worklist.pop();
1612 MemBarStoreStoreNode *storestore = n ->as_MemBarStoreStore();
1613 Node *alloc = storestore->in(MemBarNode::Precedent)->in(0);
1614 assert (alloc->is_Allocate(), "storestore should point to AllocateNode");
1615 if (not_global_escape(alloc)) {
1616 MemBarNode* mb = MemBarNode::make(C, Op_MemBarCPUOrder, Compile::AliasIdxBot);
1617 mb->init_req(TypeFunc::Memory, storestore->in(TypeFunc::Memory));
1618 mb->init_req(TypeFunc::Control, storestore->in(TypeFunc::Control));
1619 igvn->register_new_node_with_optimizer(mb);
1620 igvn->replace_node(storestore, mb);
1621 }
1622 }
1623 }
1625 // Optimize objects compare.
1626 Node* ConnectionGraph::optimize_ptr_compare(Node* n) {
1627 assert(OptimizePtrCompare, "sanity");
1628 PointsToNode* ptn1 = ptnode_adr(n->in(1)->_idx);
1629 PointsToNode* ptn2 = ptnode_adr(n->in(2)->_idx);
1630 JavaObjectNode* jobj1 = unique_java_object(n->in(1));
1631 JavaObjectNode* jobj2 = unique_java_object(n->in(2));
1632 assert(ptn1->is_JavaObject() || ptn1->is_LocalVar(), "sanity");
1633 assert(ptn2->is_JavaObject() || ptn2->is_LocalVar(), "sanity");
1635 // Check simple cases first.
1636 if (jobj1 != NULL) {
1637 if (jobj1->escape_state() == PointsToNode::NoEscape) {
1638 if (jobj1 == jobj2) {
1639 // Comparing the same not escaping object.
1640 return _pcmp_eq;
1641 }
1642 Node* obj = jobj1->ideal_node();
1643 // Comparing not escaping allocation.
1644 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1645 !ptn2->points_to(jobj1)) {
1646 return _pcmp_neq; // This includes nullness check.
1647 }
1648 }
1649 }
1650 if (jobj2 != NULL) {
1651 if (jobj2->escape_state() == PointsToNode::NoEscape) {
1652 Node* obj = jobj2->ideal_node();
1653 // Comparing not escaping allocation.
1654 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1655 !ptn1->points_to(jobj2)) {
1656 return _pcmp_neq; // This includes nullness check.
1657 }
1658 }
1659 }
1660 if (jobj1 != NULL && jobj1 != phantom_obj &&
1661 jobj2 != NULL && jobj2 != phantom_obj &&
1662 jobj1->ideal_node()->is_Con() &&
1663 jobj2->ideal_node()->is_Con()) {
1664 // Klass or String constants compare. Need to be careful with
1665 // compressed pointers - compare types of ConN and ConP instead of nodes.
1666 const Type* t1 = jobj1->ideal_node()->bottom_type()->make_ptr();
1667 const Type* t2 = jobj2->ideal_node()->bottom_type()->make_ptr();
1668 assert(t1 != NULL && t2 != NULL, "sanity");
1669 if (t1->make_ptr() == t2->make_ptr()) {
1670 return _pcmp_eq;
1671 } else {
1672 return _pcmp_neq;
1673 }
1674 }
1675 if (ptn1->meet(ptn2)) {
1676 return NULL; // Sets are not disjoint
1677 }
1679 // Sets are disjoint.
1680 bool set1_has_unknown_ptr = ptn1->points_to(phantom_obj);
1681 bool set2_has_unknown_ptr = ptn2->points_to(phantom_obj);
1682 bool set1_has_null_ptr = ptn1->points_to(null_obj);
1683 bool set2_has_null_ptr = ptn2->points_to(null_obj);
1684 if (set1_has_unknown_ptr && set2_has_null_ptr ||
1685 set2_has_unknown_ptr && set1_has_null_ptr) {
1686 // Check nullness of unknown object.
1687 return NULL;
1688 }
1690 // Disjointness by itself is not sufficient since
1691 // alias analysis is not complete for escaped objects.
1692 // Disjoint sets are definitely unrelated only when
1693 // at least one set has only not escaping allocations.
1694 if (!set1_has_unknown_ptr && !set1_has_null_ptr) {
1695 if (ptn1->non_escaping_allocation()) {
1696 return _pcmp_neq;
1697 }
1698 }
1699 if (!set2_has_unknown_ptr && !set2_has_null_ptr) {
1700 if (ptn2->non_escaping_allocation()) {
1701 return _pcmp_neq;
1702 }
1703 }
1704 return NULL;
1705 }
1707 // Connection Graph constuction functions.
1709 void ConnectionGraph::add_local_var(Node *n, PointsToNode::EscapeState es) {
1710 PointsToNode* ptadr = _nodes.at(n->_idx);
1711 if (ptadr != NULL) {
1712 assert(ptadr->is_LocalVar() && ptadr->ideal_node() == n, "sanity");
1713 return;
1714 }
1715 Compile* C = _compile;
1716 ptadr = new (C->comp_arena()) LocalVarNode(C, n, es);
1717 _nodes.at_put(n->_idx, ptadr);
1718 }
1720 void ConnectionGraph::add_java_object(Node *n, PointsToNode::EscapeState es) {
1721 PointsToNode* ptadr = _nodes.at(n->_idx);
1722 if (ptadr != NULL) {
1723 assert(ptadr->is_JavaObject() && ptadr->ideal_node() == n, "sanity");
1724 return;
1725 }
1726 Compile* C = _compile;
1727 ptadr = new (C->comp_arena()) JavaObjectNode(C, n, es);
1728 _nodes.at_put(n->_idx, ptadr);
1729 }
1731 void ConnectionGraph::add_field(Node *n, PointsToNode::EscapeState es, int offset) {
1732 PointsToNode* ptadr = _nodes.at(n->_idx);
1733 if (ptadr != NULL) {
1734 assert(ptadr->is_Field() && ptadr->ideal_node() == n, "sanity");
1735 return;
1736 }
1737 Compile* C = _compile;
1738 bool is_oop = is_oop_field(n, offset);
1739 FieldNode* field = new (C->comp_arena()) FieldNode(C, n, es, offset, is_oop);
1740 _nodes.at_put(n->_idx, field);
1741 }
1743 void ConnectionGraph::add_arraycopy(Node *n, PointsToNode::EscapeState es,
1744 PointsToNode* src, PointsToNode* dst) {
1745 assert(!src->is_Field() && !dst->is_Field(), "only for JavaObject and LocalVar");
1746 assert((src != null_obj) && (dst != null_obj), "not for ConP NULL");
1747 PointsToNode* ptadr = _nodes.at(n->_idx);
1748 if (ptadr != NULL) {
1749 assert(ptadr->is_Arraycopy() && ptadr->ideal_node() == n, "sanity");
1750 return;
1751 }
1752 Compile* C = _compile;
1753 ptadr = new (C->comp_arena()) ArraycopyNode(C, n, es);
1754 _nodes.at_put(n->_idx, ptadr);
1755 // Add edge from arraycopy node to source object.
1756 (void)add_edge(ptadr, src);
1757 src->set_arraycopy_src();
1758 // Add edge from destination object to arraycopy node.
1759 (void)add_edge(dst, ptadr);
1760 dst->set_arraycopy_dst();
1761 }
1763 bool ConnectionGraph::is_oop_field(Node* n, int offset) {
1764 const Type* adr_type = n->as_AddP()->bottom_type();
1765 BasicType bt = T_INT;
1766 if (offset == Type::OffsetBot) {
1767 // Check only oop fields.
1768 if (!adr_type->isa_aryptr() ||
1769 (adr_type->isa_aryptr()->klass() == NULL) ||
1770 adr_type->isa_aryptr()->klass()->is_obj_array_klass()) {
1771 // OffsetBot is used to reference array's element. Ignore first AddP.
1772 if (find_second_addp(n, n->in(AddPNode::Base)) == NULL) {
1773 bt = T_OBJECT;
1774 }
1775 }
1776 } else if (offset != oopDesc::klass_offset_in_bytes()) {
1777 if (adr_type->isa_instptr()) {
1778 ciField* field = _compile->alias_type(adr_type->isa_instptr())->field();
1779 if (field != NULL) {
1780 bt = field->layout_type();
1781 } else {
1782 // Ignore non field load (for example, klass load)
1783 }
1784 } else if (adr_type->isa_aryptr()) {
1785 if (offset == arrayOopDesc::length_offset_in_bytes()) {
1786 // Ignore array length load.
1787 } else if (find_second_addp(n, n->in(AddPNode::Base)) != NULL) {
1788 // Ignore first AddP.
1789 } else {
1790 const Type* elemtype = adr_type->isa_aryptr()->elem();
1791 bt = elemtype->array_element_basic_type();
1792 }
1793 } else if (adr_type->isa_rawptr() || adr_type->isa_klassptr()) {
1794 // Allocation initialization, ThreadLocal field access, unsafe access
1795 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1796 int opcode = n->fast_out(i)->Opcode();
1797 if (opcode == Op_StoreP || opcode == Op_LoadP ||
1798 opcode == Op_StoreN || opcode == Op_LoadN) {
1799 bt = T_OBJECT;
1800 }
1801 }
1802 }
1803 }
1804 return (bt == T_OBJECT || bt == T_NARROWOOP || bt == T_ARRAY);
1805 }
1807 // Returns unique pointed java object or NULL.
1808 JavaObjectNode* ConnectionGraph::unique_java_object(Node *n) {
1809 assert(!_collecting, "should not call when contructed graph");
1810 // If the node was created after the escape computation we can't answer.
1811 uint idx = n->_idx;
1812 if (idx >= nodes_size()) {
1813 return NULL;
1814 }
1815 PointsToNode* ptn = ptnode_adr(idx);
1816 if (ptn->is_JavaObject()) {
1817 return ptn->as_JavaObject();
1818 }
1819 assert(ptn->is_LocalVar(), "sanity");
1820 // Check all java objects it points to.
1821 JavaObjectNode* jobj = NULL;
1822 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1823 PointsToNode* e = i.get();
1824 if (e->is_JavaObject()) {
1825 if (jobj == NULL) {
1826 jobj = e->as_JavaObject();
1827 } else if (jobj != e) {
1828 return NULL;
1829 }
1830 }
1831 }
1832 return jobj;
1833 }
1835 // Return true if this node points only to non-escaping allocations.
1836 bool PointsToNode::non_escaping_allocation() {
1837 if (is_JavaObject()) {
1838 Node* n = ideal_node();
1839 if (n->is_Allocate() || n->is_CallStaticJava()) {
1840 return (escape_state() == PointsToNode::NoEscape);
1841 } else {
1842 return false;
1843 }
1844 }
1845 assert(is_LocalVar(), "sanity");
1846 // Check all java objects it points to.
1847 for (EdgeIterator i(this); i.has_next(); i.next()) {
1848 PointsToNode* e = i.get();
1849 if (e->is_JavaObject()) {
1850 Node* n = e->ideal_node();
1851 if ((e->escape_state() != PointsToNode::NoEscape) ||
1852 !(n->is_Allocate() || n->is_CallStaticJava())) {
1853 return false;
1854 }
1855 }
1856 }
1857 return true;
1858 }
1860 // Return true if we know the node does not escape globally.
1861 bool ConnectionGraph::not_global_escape(Node *n) {
1862 assert(!_collecting, "should not call during graph construction");
1863 // If the node was created after the escape computation we can't answer.
1864 uint idx = n->_idx;
1865 if (idx >= nodes_size()) {
1866 return false;
1867 }
1868 PointsToNode* ptn = ptnode_adr(idx);
1869 PointsToNode::EscapeState es = ptn->escape_state();
1870 // If we have already computed a value, return it.
1871 if (es >= PointsToNode::GlobalEscape)
1872 return false;
1873 if (ptn->is_JavaObject()) {
1874 return true; // (es < PointsToNode::GlobalEscape);
1875 }
1876 assert(ptn->is_LocalVar(), "sanity");
1877 // Check all java objects it points to.
1878 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1879 if (i.get()->escape_state() >= PointsToNode::GlobalEscape)
1880 return false;
1881 }
1882 return true;
1883 }
1886 // Helper functions
1888 // Return true if this node points to specified node or nodes it points to.
1889 bool PointsToNode::points_to(JavaObjectNode* ptn) const {
1890 if (is_JavaObject()) {
1891 return (this == ptn);
1892 }
1893 assert(is_LocalVar(), "sanity");
1894 for (EdgeIterator i(this); i.has_next(); i.next()) {
1895 if (i.get() == ptn)
1896 return true;
1897 }
1898 return false;
1899 }
1901 // Return true if one node points to an other.
1902 bool PointsToNode::meet(PointsToNode* ptn) {
1903 if (this == ptn) {
1904 return true;
1905 } else if (ptn->is_JavaObject()) {
1906 return this->points_to(ptn->as_JavaObject());
1907 } else if (this->is_JavaObject()) {
1908 return ptn->points_to(this->as_JavaObject());
1909 }
1910 assert(this->is_LocalVar() && ptn->is_LocalVar(), "sanity");
1911 int ptn_count = ptn->edge_count();
1912 for (EdgeIterator i(this); i.has_next(); i.next()) {
1913 PointsToNode* this_e = i.get();
1914 for (int j = 0; j < ptn_count; j++) {
1915 if (this_e == ptn->edge(j))
1916 return true;
1917 }
1918 }
1919 return false;
1920 }
1922 #ifdef ASSERT
1923 // Return true if bases point to this java object.
1924 bool FieldNode::has_base(JavaObjectNode* jobj) const {
1925 for (BaseIterator i(this); i.has_next(); i.next()) {
1926 if (i.get() == jobj)
1927 return true;
1928 }
1929 return false;
1930 }
1931 #endif
1933 int ConnectionGraph::address_offset(Node* adr, PhaseTransform *phase) {
1934 const Type *adr_type = phase->type(adr);
1935 if (adr->is_AddP() && adr_type->isa_oopptr() == NULL &&
1936 adr->in(AddPNode::Address)->is_Proj() &&
1937 adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
1938 // We are computing a raw address for a store captured by an Initialize
1939 // compute an appropriate address type. AddP cases #3 and #5 (see below).
1940 int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
1941 assert(offs != Type::OffsetBot ||
1942 adr->in(AddPNode::Address)->in(0)->is_AllocateArray(),
1943 "offset must be a constant or it is initialization of array");
1944 return offs;
1945 }
1946 const TypePtr *t_ptr = adr_type->isa_ptr();
1947 assert(t_ptr != NULL, "must be a pointer type");
1948 return t_ptr->offset();
1949 }
1951 Node* ConnectionGraph::get_addp_base(Node *addp) {
1952 assert(addp->is_AddP(), "must be AddP");
1953 //
1954 // AddP cases for Base and Address inputs:
1955 // case #1. Direct object's field reference:
1956 // Allocate
1957 // |
1958 // Proj #5 ( oop result )
1959 // |
1960 // CheckCastPP (cast to instance type)
1961 // | |
1962 // AddP ( base == address )
1963 //
1964 // case #2. Indirect object's field reference:
1965 // Phi
1966 // |
1967 // CastPP (cast to instance type)
1968 // | |
1969 // AddP ( base == address )
1970 //
1971 // case #3. Raw object's field reference for Initialize node:
1972 // Allocate
1973 // |
1974 // Proj #5 ( oop result )
1975 // top |
1976 // \ |
1977 // AddP ( base == top )
1978 //
1979 // case #4. Array's element reference:
1980 // {CheckCastPP | CastPP}
1981 // | | |
1982 // | AddP ( array's element offset )
1983 // | |
1984 // AddP ( array's offset )
1985 //
1986 // case #5. Raw object's field reference for arraycopy stub call:
1987 // The inline_native_clone() case when the arraycopy stub is called
1988 // after the allocation before Initialize and CheckCastPP nodes.
1989 // Allocate
1990 // |
1991 // Proj #5 ( oop result )
1992 // | |
1993 // AddP ( base == address )
1994 //
1995 // case #6. Constant Pool, ThreadLocal, CastX2P or
1996 // Raw object's field reference:
1997 // {ConP, ThreadLocal, CastX2P, raw Load}
1998 // top |
1999 // \ |
2000 // AddP ( base == top )
2001 //
2002 // case #7. Klass's field reference.
2003 // LoadKlass
2004 // | |
2005 // AddP ( base == address )
2006 //
2007 // case #8. narrow Klass's field reference.
2008 // LoadNKlass
2009 // |
2010 // DecodeN
2011 // | |
2012 // AddP ( base == address )
2013 //
2014 Node *base = addp->in(AddPNode::Base);
2015 if (base->uncast()->is_top()) { // The AddP case #3 and #6.
2016 base = addp->in(AddPNode::Address);
2017 while (base->is_AddP()) {
2018 // Case #6 (unsafe access) may have several chained AddP nodes.
2019 assert(base->in(AddPNode::Base)->uncast()->is_top(), "expected unsafe access address only");
2020 base = base->in(AddPNode::Address);
2021 }
2022 Node* uncast_base = base->uncast();
2023 int opcode = uncast_base->Opcode();
2024 assert(opcode == Op_ConP || opcode == Op_ThreadLocal ||
2025 opcode == Op_CastX2P || uncast_base->is_DecodeN() ||
2026 (uncast_base->is_Mem() && uncast_base->bottom_type() == TypeRawPtr::NOTNULL) ||
2027 (uncast_base->is_Proj() && uncast_base->in(0)->is_Allocate()), "sanity");
2028 }
2029 return base;
2030 }
2032 Node* ConnectionGraph::find_second_addp(Node* addp, Node* n) {
2033 assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
2034 Node* addp2 = addp->raw_out(0);
2035 if (addp->outcnt() == 1 && addp2->is_AddP() &&
2036 addp2->in(AddPNode::Base) == n &&
2037 addp2->in(AddPNode::Address) == addp) {
2038 assert(addp->in(AddPNode::Base) == n, "expecting the same base");
2039 //
2040 // Find array's offset to push it on worklist first and
2041 // as result process an array's element offset first (pushed second)
2042 // to avoid CastPP for the array's offset.
2043 // Otherwise the inserted CastPP (LocalVar) will point to what
2044 // the AddP (Field) points to. Which would be wrong since
2045 // the algorithm expects the CastPP has the same point as
2046 // as AddP's base CheckCastPP (LocalVar).
2047 //
2048 // ArrayAllocation
2049 // |
2050 // CheckCastPP
2051 // |
2052 // memProj (from ArrayAllocation CheckCastPP)
2053 // | ||
2054 // | || Int (element index)
2055 // | || | ConI (log(element size))
2056 // | || | /
2057 // | || LShift
2058 // | || /
2059 // | AddP (array's element offset)
2060 // | |
2061 // | | ConI (array's offset: #12(32-bits) or #24(64-bits))
2062 // | / /
2063 // AddP (array's offset)
2064 // |
2065 // Load/Store (memory operation on array's element)
2066 //
2067 return addp2;
2068 }
2069 return NULL;
2070 }
2072 //
2073 // Adjust the type and inputs of an AddP which computes the
2074 // address of a field of an instance
2075 //
2076 bool ConnectionGraph::split_AddP(Node *addp, Node *base) {
2077 PhaseGVN* igvn = _igvn;
2078 const TypeOopPtr *base_t = igvn->type(base)->isa_oopptr();
2079 assert(base_t != NULL && base_t->is_known_instance(), "expecting instance oopptr");
2080 const TypeOopPtr *t = igvn->type(addp)->isa_oopptr();
2081 if (t == NULL) {
2082 // We are computing a raw address for a store captured by an Initialize
2083 // compute an appropriate address type (cases #3 and #5).
2084 assert(igvn->type(addp) == TypeRawPtr::NOTNULL, "must be raw pointer");
2085 assert(addp->in(AddPNode::Address)->is_Proj(), "base of raw address must be result projection from allocation");
2086 intptr_t offs = (int)igvn->find_intptr_t_con(addp->in(AddPNode::Offset), Type::OffsetBot);
2087 assert(offs != Type::OffsetBot, "offset must be a constant");
2088 t = base_t->add_offset(offs)->is_oopptr();
2089 }
2090 int inst_id = base_t->instance_id();
2091 assert(!t->is_known_instance() || t->instance_id() == inst_id,
2092 "old type must be non-instance or match new type");
2094 // The type 't' could be subclass of 'base_t'.
2095 // As result t->offset() could be large then base_t's size and it will
2096 // cause the failure in add_offset() with narrow oops since TypeOopPtr()
2097 // constructor verifies correctness of the offset.
2098 //
2099 // It could happened on subclass's branch (from the type profiling
2100 // inlining) which was not eliminated during parsing since the exactness
2101 // of the allocation type was not propagated to the subclass type check.
2102 //
2103 // Or the type 't' could be not related to 'base_t' at all.
2104 // It could happened when CHA type is different from MDO type on a dead path
2105 // (for example, from instanceof check) which is not collapsed during parsing.
2106 //
2107 // Do nothing for such AddP node and don't process its users since
2108 // this code branch will go away.
2109 //
2110 if (!t->is_known_instance() &&
2111 !base_t->klass()->is_subtype_of(t->klass())) {
2112 return false; // bail out
2113 }
2114 const TypeOopPtr *tinst = base_t->add_offset(t->offset())->is_oopptr();
2115 // Do NOT remove the next line: ensure a new alias index is allocated
2116 // for the instance type. Note: C++ will not remove it since the call
2117 // has side effect.
2118 int alias_idx = _compile->get_alias_index(tinst);
2119 igvn->set_type(addp, tinst);
2120 // record the allocation in the node map
2121 set_map(addp, get_map(base->_idx));
2122 // Set addp's Base and Address to 'base'.
2123 Node *abase = addp->in(AddPNode::Base);
2124 Node *adr = addp->in(AddPNode::Address);
2125 if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
2126 adr->in(0)->_idx == (uint)inst_id) {
2127 // Skip AddP cases #3 and #5.
2128 } else {
2129 assert(!abase->is_top(), "sanity"); // AddP case #3
2130 if (abase != base) {
2131 igvn->hash_delete(addp);
2132 addp->set_req(AddPNode::Base, base);
2133 if (abase == adr) {
2134 addp->set_req(AddPNode::Address, base);
2135 } else {
2136 // AddP case #4 (adr is array's element offset AddP node)
2137 #ifdef ASSERT
2138 const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
2139 assert(adr->is_AddP() && atype != NULL &&
2140 atype->instance_id() == inst_id, "array's element offset should be processed first");
2141 #endif
2142 }
2143 igvn->hash_insert(addp);
2144 }
2145 }
2146 // Put on IGVN worklist since at least addp's type was changed above.
2147 record_for_optimizer(addp);
2148 return true;
2149 }
2151 //
2152 // Create a new version of orig_phi if necessary. Returns either the newly
2153 // created phi or an existing phi. Sets create_new to indicate whether a new
2154 // phi was created. Cache the last newly created phi in the node map.
2155 //
2156 PhiNode *ConnectionGraph::create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist, bool &new_created) {
2157 Compile *C = _compile;
2158 PhaseGVN* igvn = _igvn;
2159 new_created = false;
2160 int phi_alias_idx = C->get_alias_index(orig_phi->adr_type());
2161 // nothing to do if orig_phi is bottom memory or matches alias_idx
2162 if (phi_alias_idx == alias_idx) {
2163 return orig_phi;
2164 }
2165 // Have we recently created a Phi for this alias index?
2166 PhiNode *result = get_map_phi(orig_phi->_idx);
2167 if (result != NULL && C->get_alias_index(result->adr_type()) == alias_idx) {
2168 return result;
2169 }
2170 // Previous check may fail when the same wide memory Phi was split into Phis
2171 // for different memory slices. Search all Phis for this region.
2172 if (result != NULL) {
2173 Node* region = orig_phi->in(0);
2174 for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
2175 Node* phi = region->fast_out(i);
2176 if (phi->is_Phi() &&
2177 C->get_alias_index(phi->as_Phi()->adr_type()) == alias_idx) {
2178 assert(phi->_idx >= nodes_size(), "only new Phi per instance memory slice");
2179 return phi->as_Phi();
2180 }
2181 }
2182 }
2183 if ((int)C->unique() + 2*NodeLimitFudgeFactor > MaxNodeLimit) {
2184 if (C->do_escape_analysis() == true && !C->failing()) {
2185 // Retry compilation without escape analysis.
2186 // If this is the first failure, the sentinel string will "stick"
2187 // to the Compile object, and the C2Compiler will see it and retry.
2188 C->record_failure(C2Compiler::retry_no_escape_analysis());
2189 }
2190 return NULL;
2191 }
2192 orig_phi_worklist.append_if_missing(orig_phi);
2193 const TypePtr *atype = C->get_adr_type(alias_idx);
2194 result = PhiNode::make(orig_phi->in(0), NULL, Type::MEMORY, atype);
2195 C->copy_node_notes_to(result, orig_phi);
2196 igvn->set_type(result, result->bottom_type());
2197 record_for_optimizer(result);
2198 set_map(orig_phi, result);
2199 new_created = true;
2200 return result;
2201 }
2203 //
2204 // Return a new version of Memory Phi "orig_phi" with the inputs having the
2205 // specified alias index.
2206 //
2207 PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist) {
2208 assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
2209 Compile *C = _compile;
2210 PhaseGVN* igvn = _igvn;
2211 bool new_phi_created;
2212 PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, new_phi_created);
2213 if (!new_phi_created) {
2214 return result;
2215 }
2216 GrowableArray<PhiNode *> phi_list;
2217 GrowableArray<uint> cur_input;
2218 PhiNode *phi = orig_phi;
2219 uint idx = 1;
2220 bool finished = false;
2221 while(!finished) {
2222 while (idx < phi->req()) {
2223 Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist);
2224 if (mem != NULL && mem->is_Phi()) {
2225 PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, new_phi_created);
2226 if (new_phi_created) {
2227 // found an phi for which we created a new split, push current one on worklist and begin
2228 // processing new one
2229 phi_list.push(phi);
2230 cur_input.push(idx);
2231 phi = mem->as_Phi();
2232 result = newphi;
2233 idx = 1;
2234 continue;
2235 } else {
2236 mem = newphi;
2237 }
2238 }
2239 if (C->failing()) {
2240 return NULL;
2241 }
2242 result->set_req(idx++, mem);
2243 }
2244 #ifdef ASSERT
2245 // verify that the new Phi has an input for each input of the original
2246 assert( phi->req() == result->req(), "must have same number of inputs.");
2247 assert( result->in(0) != NULL && result->in(0) == phi->in(0), "regions must match");
2248 #endif
2249 // Check if all new phi's inputs have specified alias index.
2250 // Otherwise use old phi.
2251 for (uint i = 1; i < phi->req(); i++) {
2252 Node* in = result->in(i);
2253 assert((phi->in(i) == NULL) == (in == NULL), "inputs must correspond.");
2254 }
2255 // we have finished processing a Phi, see if there are any more to do
2256 finished = (phi_list.length() == 0 );
2257 if (!finished) {
2258 phi = phi_list.pop();
2259 idx = cur_input.pop();
2260 PhiNode *prev_result = get_map_phi(phi->_idx);
2261 prev_result->set_req(idx++, result);
2262 result = prev_result;
2263 }
2264 }
2265 return result;
2266 }
2268 //
2269 // The next methods are derived from methods in MemNode.
2270 //
2271 Node* ConnectionGraph::step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *toop) {
2272 Node *mem = mmem;
2273 // TypeOopPtr::NOTNULL+any is an OOP with unknown offset - generally
2274 // means an array I have not precisely typed yet. Do not do any
2275 // alias stuff with it any time soon.
2276 if (toop->base() != Type::AnyPtr &&
2277 !(toop->klass() != NULL &&
2278 toop->klass()->is_java_lang_Object() &&
2279 toop->offset() == Type::OffsetBot)) {
2280 mem = mmem->memory_at(alias_idx);
2281 // Update input if it is progress over what we have now
2282 }
2283 return mem;
2284 }
2286 //
2287 // Move memory users to their memory slices.
2288 //
2289 void ConnectionGraph::move_inst_mem(Node* n, GrowableArray<PhiNode *> &orig_phis) {
2290 Compile* C = _compile;
2291 PhaseGVN* igvn = _igvn;
2292 const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr();
2293 assert(tp != NULL, "ptr type");
2294 int alias_idx = C->get_alias_index(tp);
2295 int general_idx = C->get_general_index(alias_idx);
2297 // Move users first
2298 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2299 Node* use = n->fast_out(i);
2300 if (use->is_MergeMem()) {
2301 MergeMemNode* mmem = use->as_MergeMem();
2302 assert(n == mmem->memory_at(alias_idx), "should be on instance memory slice");
2303 if (n != mmem->memory_at(general_idx) || alias_idx == general_idx) {
2304 continue; // Nothing to do
2305 }
2306 // Replace previous general reference to mem node.
2307 uint orig_uniq = C->unique();
2308 Node* m = find_inst_mem(n, general_idx, orig_phis);
2309 assert(orig_uniq == C->unique(), "no new nodes");
2310 mmem->set_memory_at(general_idx, m);
2311 --imax;
2312 --i;
2313 } else if (use->is_MemBar()) {
2314 assert(!use->is_Initialize(), "initializing stores should not be moved");
2315 if (use->req() > MemBarNode::Precedent &&
2316 use->in(MemBarNode::Precedent) == n) {
2317 // Don't move related membars.
2318 record_for_optimizer(use);
2319 continue;
2320 }
2321 tp = use->as_MemBar()->adr_type()->isa_ptr();
2322 if (tp != NULL && C->get_alias_index(tp) == alias_idx ||
2323 alias_idx == general_idx) {
2324 continue; // Nothing to do
2325 }
2326 // Move to general memory slice.
2327 uint orig_uniq = C->unique();
2328 Node* m = find_inst_mem(n, general_idx, orig_phis);
2329 assert(orig_uniq == C->unique(), "no new nodes");
2330 igvn->hash_delete(use);
2331 imax -= use->replace_edge(n, m);
2332 igvn->hash_insert(use);
2333 record_for_optimizer(use);
2334 --i;
2335 #ifdef ASSERT
2336 } else if (use->is_Mem()) {
2337 if (use->Opcode() == Op_StoreCM && use->in(MemNode::OopStore) == n) {
2338 // Don't move related cardmark.
2339 continue;
2340 }
2341 // Memory nodes should have new memory input.
2342 tp = igvn->type(use->in(MemNode::Address))->isa_ptr();
2343 assert(tp != NULL, "ptr type");
2344 int idx = C->get_alias_index(tp);
2345 assert(get_map(use->_idx) != NULL || idx == alias_idx,
2346 "Following memory nodes should have new memory input or be on the same memory slice");
2347 } else if (use->is_Phi()) {
2348 // Phi nodes should be split and moved already.
2349 tp = use->as_Phi()->adr_type()->isa_ptr();
2350 assert(tp != NULL, "ptr type");
2351 int idx = C->get_alias_index(tp);
2352 assert(idx == alias_idx, "Following Phi nodes should be on the same memory slice");
2353 } else {
2354 use->dump();
2355 assert(false, "should not be here");
2356 #endif
2357 }
2358 }
2359 }
2361 //
2362 // Search memory chain of "mem" to find a MemNode whose address
2363 // is the specified alias index.
2364 //
2365 Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArray<PhiNode *> &orig_phis) {
2366 if (orig_mem == NULL)
2367 return orig_mem;
2368 Compile* C = _compile;
2369 PhaseGVN* igvn = _igvn;
2370 const TypeOopPtr *toop = C->get_adr_type(alias_idx)->isa_oopptr();
2371 bool is_instance = (toop != NULL) && toop->is_known_instance();
2372 Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
2373 Node *prev = NULL;
2374 Node *result = orig_mem;
2375 while (prev != result) {
2376 prev = result;
2377 if (result == start_mem)
2378 break; // hit one of our sentinels
2379 if (result->is_Mem()) {
2380 const Type *at = igvn->type(result->in(MemNode::Address));
2381 if (at == Type::TOP)
2382 break; // Dead
2383 assert (at->isa_ptr() != NULL, "pointer type required.");
2384 int idx = C->get_alias_index(at->is_ptr());
2385 if (idx == alias_idx)
2386 break; // Found
2387 if (!is_instance && (at->isa_oopptr() == NULL ||
2388 !at->is_oopptr()->is_known_instance())) {
2389 break; // Do not skip store to general memory slice.
2390 }
2391 result = result->in(MemNode::Memory);
2392 }
2393 if (!is_instance)
2394 continue; // don't search further for non-instance types
2395 // skip over a call which does not affect this memory slice
2396 if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) {
2397 Node *proj_in = result->in(0);
2398 if (proj_in->is_Allocate() && proj_in->_idx == (uint)toop->instance_id()) {
2399 break; // hit one of our sentinels
2400 } else if (proj_in->is_Call()) {
2401 CallNode *call = proj_in->as_Call();
2402 if (!call->may_modify(toop, igvn)) {
2403 result = call->in(TypeFunc::Memory);
2404 }
2405 } else if (proj_in->is_Initialize()) {
2406 AllocateNode* alloc = proj_in->as_Initialize()->allocation();
2407 // Stop if this is the initialization for the object instance which
2408 // which contains this memory slice, otherwise skip over it.
2409 if (alloc == NULL || alloc->_idx != (uint)toop->instance_id()) {
2410 result = proj_in->in(TypeFunc::Memory);
2411 }
2412 } else if (proj_in->is_MemBar()) {
2413 result = proj_in->in(TypeFunc::Memory);
2414 }
2415 } else if (result->is_MergeMem()) {
2416 MergeMemNode *mmem = result->as_MergeMem();
2417 result = step_through_mergemem(mmem, alias_idx, toop);
2418 if (result == mmem->base_memory()) {
2419 // Didn't find instance memory, search through general slice recursively.
2420 result = mmem->memory_at(C->get_general_index(alias_idx));
2421 result = find_inst_mem(result, alias_idx, orig_phis);
2422 if (C->failing()) {
2423 return NULL;
2424 }
2425 mmem->set_memory_at(alias_idx, result);
2426 }
2427 } else if (result->is_Phi() &&
2428 C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) {
2429 Node *un = result->as_Phi()->unique_input(igvn);
2430 if (un != NULL) {
2431 orig_phis.append_if_missing(result->as_Phi());
2432 result = un;
2433 } else {
2434 break;
2435 }
2436 } else if (result->is_ClearArray()) {
2437 if (!ClearArrayNode::step_through(&result, (uint)toop->instance_id(), igvn)) {
2438 // Can not bypass initialization of the instance
2439 // we are looking for.
2440 break;
2441 }
2442 // Otherwise skip it (the call updated 'result' value).
2443 } else if (result->Opcode() == Op_SCMemProj) {
2444 assert(result->in(0)->is_LoadStore(), "sanity");
2445 const Type *at = igvn->type(result->in(0)->in(MemNode::Address));
2446 if (at != Type::TOP) {
2447 assert (at->isa_ptr() != NULL, "pointer type required.");
2448 int idx = C->get_alias_index(at->is_ptr());
2449 assert(idx != alias_idx, "Object is not scalar replaceable if a LoadStore node access its field");
2450 break;
2451 }
2452 result = result->in(0)->in(MemNode::Memory);
2453 }
2454 }
2455 if (result->is_Phi()) {
2456 PhiNode *mphi = result->as_Phi();
2457 assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
2458 const TypePtr *t = mphi->adr_type();
2459 if (!is_instance) {
2460 // Push all non-instance Phis on the orig_phis worklist to update inputs
2461 // during Phase 4 if needed.
2462 orig_phis.append_if_missing(mphi);
2463 } else if (C->get_alias_index(t) != alias_idx) {
2464 // Create a new Phi with the specified alias index type.
2465 result = split_memory_phi(mphi, alias_idx, orig_phis);
2466 }
2467 }
2468 // the result is either MemNode, PhiNode, InitializeNode.
2469 return result;
2470 }
2472 //
2473 // Convert the types of unescaped object to instance types where possible,
2474 // propagate the new type information through the graph, and update memory
2475 // edges and MergeMem inputs to reflect the new type.
2476 //
2477 // We start with allocations (and calls which may be allocations) on alloc_worklist.
2478 // The processing is done in 4 phases:
2479 //
2480 // Phase 1: Process possible allocations from alloc_worklist. Create instance
2481 // types for the CheckCastPP for allocations where possible.
2482 // Propagate the the new types through users as follows:
2483 // casts and Phi: push users on alloc_worklist
2484 // AddP: cast Base and Address inputs to the instance type
2485 // push any AddP users on alloc_worklist and push any memnode
2486 // users onto memnode_worklist.
2487 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
2488 // search the Memory chain for a store with the appropriate type
2489 // address type. If a Phi is found, create a new version with
2490 // the appropriate memory slices from each of the Phi inputs.
2491 // For stores, process the users as follows:
2492 // MemNode: push on memnode_worklist
2493 // MergeMem: push on mergemem_worklist
2494 // Phase 3: Process MergeMem nodes from mergemem_worklist. Walk each memory slice
2495 // moving the first node encountered of each instance type to the
2496 // the input corresponding to its alias index.
2497 // appropriate memory slice.
2498 // Phase 4: Update the inputs of non-instance memory Phis and the Memory input of memnodes.
2499 //
2500 // In the following example, the CheckCastPP nodes are the cast of allocation
2501 // results and the allocation of node 29 is unescaped and eligible to be an
2502 // instance type.
2503 //
2504 // We start with:
2505 //
2506 // 7 Parm #memory
2507 // 10 ConI "12"
2508 // 19 CheckCastPP "Foo"
2509 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2510 // 29 CheckCastPP "Foo"
2511 // 30 AddP _ 29 29 10 Foo+12 alias_index=4
2512 //
2513 // 40 StoreP 25 7 20 ... alias_index=4
2514 // 50 StoreP 35 40 30 ... alias_index=4
2515 // 60 StoreP 45 50 20 ... alias_index=4
2516 // 70 LoadP _ 60 30 ... alias_index=4
2517 // 80 Phi 75 50 60 Memory alias_index=4
2518 // 90 LoadP _ 80 30 ... alias_index=4
2519 // 100 LoadP _ 80 20 ... alias_index=4
2520 //
2521 //
2522 // Phase 1 creates an instance type for node 29 assigning it an instance id of 24
2523 // and creating a new alias index for node 30. This gives:
2524 //
2525 // 7 Parm #memory
2526 // 10 ConI "12"
2527 // 19 CheckCastPP "Foo"
2528 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2529 // 29 CheckCastPP "Foo" iid=24
2530 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
2531 //
2532 // 40 StoreP 25 7 20 ... alias_index=4
2533 // 50 StoreP 35 40 30 ... alias_index=6
2534 // 60 StoreP 45 50 20 ... alias_index=4
2535 // 70 LoadP _ 60 30 ... alias_index=6
2536 // 80 Phi 75 50 60 Memory alias_index=4
2537 // 90 LoadP _ 80 30 ... alias_index=6
2538 // 100 LoadP _ 80 20 ... alias_index=4
2539 //
2540 // In phase 2, new memory inputs are computed for the loads and stores,
2541 // And a new version of the phi is created. In phase 4, the inputs to
2542 // node 80 are updated and then the memory nodes are updated with the
2543 // values computed in phase 2. This results in:
2544 //
2545 // 7 Parm #memory
2546 // 10 ConI "12"
2547 // 19 CheckCastPP "Foo"
2548 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2549 // 29 CheckCastPP "Foo" iid=24
2550 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
2551 //
2552 // 40 StoreP 25 7 20 ... alias_index=4
2553 // 50 StoreP 35 7 30 ... alias_index=6
2554 // 60 StoreP 45 40 20 ... alias_index=4
2555 // 70 LoadP _ 50 30 ... alias_index=6
2556 // 80 Phi 75 40 60 Memory alias_index=4
2557 // 120 Phi 75 50 50 Memory alias_index=6
2558 // 90 LoadP _ 120 30 ... alias_index=6
2559 // 100 LoadP _ 80 20 ... alias_index=4
2560 //
2561 void ConnectionGraph::split_unique_types(GrowableArray<Node *> &alloc_worklist) {
2562 GrowableArray<Node *> memnode_worklist;
2563 GrowableArray<PhiNode *> orig_phis;
2564 PhaseIterGVN *igvn = _igvn;
2565 uint new_index_start = (uint) _compile->num_alias_types();
2566 Arena* arena = Thread::current()->resource_area();
2567 VectorSet visited(arena);
2568 ideal_nodes.clear(); // Reset for use with set_map/get_map.
2569 uint unique_old = _compile->unique();
2571 // Phase 1: Process possible allocations from alloc_worklist.
2572 // Create instance types for the CheckCastPP for allocations where possible.
2573 //
2574 // (Note: don't forget to change the order of the second AddP node on
2575 // the alloc_worklist if the order of the worklist processing is changed,
2576 // see the comment in find_second_addp().)
2577 //
2578 while (alloc_worklist.length() != 0) {
2579 Node *n = alloc_worklist.pop();
2580 uint ni = n->_idx;
2581 if (n->is_Call()) {
2582 CallNode *alloc = n->as_Call();
2583 // copy escape information to call node
2584 PointsToNode* ptn = ptnode_adr(alloc->_idx);
2585 PointsToNode::EscapeState es = ptn->escape_state();
2586 // We have an allocation or call which returns a Java object,
2587 // see if it is unescaped.
2588 if (es != PointsToNode::NoEscape || !ptn->scalar_replaceable())
2589 continue;
2590 // Find CheckCastPP for the allocate or for the return value of a call
2591 n = alloc->result_cast();
2592 if (n == NULL) { // No uses except Initialize node
2593 if (alloc->is_Allocate()) {
2594 // Set the scalar_replaceable flag for allocation
2595 // so it could be eliminated if it has no uses.
2596 alloc->as_Allocate()->_is_scalar_replaceable = true;
2597 }
2598 continue;
2599 }
2600 if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
2601 assert(!alloc->is_Allocate(), "allocation should have unique type");
2602 continue;
2603 }
2605 // The inline code for Object.clone() casts the allocation result to
2606 // java.lang.Object and then to the actual type of the allocated
2607 // object. Detect this case and use the second cast.
2608 // Also detect j.l.reflect.Array.newInstance(jobject, jint) case when
2609 // the allocation result is cast to java.lang.Object and then
2610 // to the actual Array type.
2611 if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL
2612 && (alloc->is_AllocateArray() ||
2613 igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeKlassPtr::OBJECT)) {
2614 Node *cast2 = NULL;
2615 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2616 Node *use = n->fast_out(i);
2617 if (use->is_CheckCastPP()) {
2618 cast2 = use;
2619 break;
2620 }
2621 }
2622 if (cast2 != NULL) {
2623 n = cast2;
2624 } else {
2625 // Non-scalar replaceable if the allocation type is unknown statically
2626 // (reflection allocation), the object can't be restored during
2627 // deoptimization without precise type.
2628 continue;
2629 }
2630 }
2631 if (alloc->is_Allocate()) {
2632 // Set the scalar_replaceable flag for allocation
2633 // so it could be eliminated.
2634 alloc->as_Allocate()->_is_scalar_replaceable = true;
2635 }
2636 set_escape_state(ptnode_adr(n->_idx), es); // CheckCastPP escape state
2637 // in order for an object to be scalar-replaceable, it must be:
2638 // - a direct allocation (not a call returning an object)
2639 // - non-escaping
2640 // - eligible to be a unique type
2641 // - not determined to be ineligible by escape analysis
2642 set_map(alloc, n);
2643 set_map(n, alloc);
2644 const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
2645 if (t == NULL)
2646 continue; // not a TypeOopPtr
2647 const TypeOopPtr* tinst = t->cast_to_exactness(true)->is_oopptr()->cast_to_instance_id(ni);
2648 igvn->hash_delete(n);
2649 igvn->set_type(n, tinst);
2650 n->raise_bottom_type(tinst);
2651 igvn->hash_insert(n);
2652 record_for_optimizer(n);
2653 if (alloc->is_Allocate() && (t->isa_instptr() || t->isa_aryptr())) {
2655 // First, put on the worklist all Field edges from Connection Graph
2656 // which is more accurate then putting immediate users from Ideal Graph.
2657 for (EdgeIterator e(ptn); e.has_next(); e.next()) {
2658 PointsToNode* tgt = e.get();
2659 Node* use = tgt->ideal_node();
2660 assert(tgt->is_Field() && use->is_AddP(),
2661 "only AddP nodes are Field edges in CG");
2662 if (use->outcnt() > 0) { // Don't process dead nodes
2663 Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
2664 if (addp2 != NULL) {
2665 assert(alloc->is_AllocateArray(),"array allocation was expected");
2666 alloc_worklist.append_if_missing(addp2);
2667 }
2668 alloc_worklist.append_if_missing(use);
2669 }
2670 }
2672 // An allocation may have an Initialize which has raw stores. Scan
2673 // the users of the raw allocation result and push AddP users
2674 // on alloc_worklist.
2675 Node *raw_result = alloc->proj_out(TypeFunc::Parms);
2676 assert (raw_result != NULL, "must have an allocation result");
2677 for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
2678 Node *use = raw_result->fast_out(i);
2679 if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
2680 Node* addp2 = find_second_addp(use, raw_result);
2681 if (addp2 != NULL) {
2682 assert(alloc->is_AllocateArray(),"array allocation was expected");
2683 alloc_worklist.append_if_missing(addp2);
2684 }
2685 alloc_worklist.append_if_missing(use);
2686 } else if (use->is_MemBar()) {
2687 memnode_worklist.append_if_missing(use);
2688 }
2689 }
2690 }
2691 } else if (n->is_AddP()) {
2692 JavaObjectNode* jobj = unique_java_object(get_addp_base(n));
2693 if (jobj == NULL || jobj == phantom_obj) {
2694 #ifdef ASSERT
2695 ptnode_adr(get_addp_base(n)->_idx)->dump();
2696 ptnode_adr(n->_idx)->dump();
2697 assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
2698 #endif
2699 _compile->record_failure(C2Compiler::retry_no_escape_analysis());
2700 return;
2701 }
2702 Node *base = get_map(jobj->idx()); // CheckCastPP node
2703 if (!split_AddP(n, base)) continue; // wrong type from dead path
2704 } else if (n->is_Phi() ||
2705 n->is_CheckCastPP() ||
2706 n->is_EncodeP() ||
2707 n->is_DecodeN() ||
2708 (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
2709 if (visited.test_set(n->_idx)) {
2710 assert(n->is_Phi(), "loops only through Phi's");
2711 continue; // already processed
2712 }
2713 JavaObjectNode* jobj = unique_java_object(n);
2714 if (jobj == NULL || jobj == phantom_obj) {
2715 #ifdef ASSERT
2716 ptnode_adr(n->_idx)->dump();
2717 assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
2718 #endif
2719 _compile->record_failure(C2Compiler::retry_no_escape_analysis());
2720 return;
2721 } else {
2722 Node *val = get_map(jobj->idx()); // CheckCastPP node
2723 TypeNode *tn = n->as_Type();
2724 const TypeOopPtr* tinst = igvn->type(val)->isa_oopptr();
2725 assert(tinst != NULL && tinst->is_known_instance() &&
2726 tinst->instance_id() == jobj->idx() , "instance type expected.");
2728 const Type *tn_type = igvn->type(tn);
2729 const TypeOopPtr *tn_t;
2730 if (tn_type->isa_narrowoop()) {
2731 tn_t = tn_type->make_ptr()->isa_oopptr();
2732 } else {
2733 tn_t = tn_type->isa_oopptr();
2734 }
2735 if (tn_t != NULL && tinst->klass()->is_subtype_of(tn_t->klass())) {
2736 if (tn_type->isa_narrowoop()) {
2737 tn_type = tinst->make_narrowoop();
2738 } else {
2739 tn_type = tinst;
2740 }
2741 igvn->hash_delete(tn);
2742 igvn->set_type(tn, tn_type);
2743 tn->set_type(tn_type);
2744 igvn->hash_insert(tn);
2745 record_for_optimizer(n);
2746 } else {
2747 assert(tn_type == TypePtr::NULL_PTR ||
2748 tn_t != NULL && !tinst->klass()->is_subtype_of(tn_t->klass()),
2749 "unexpected type");
2750 continue; // Skip dead path with different type
2751 }
2752 }
2753 } else {
2754 debug_only(n->dump();)
2755 assert(false, "EA: unexpected node");
2756 continue;
2757 }
2758 // push allocation's users on appropriate worklist
2759 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2760 Node *use = n->fast_out(i);
2761 if(use->is_Mem() && use->in(MemNode::Address) == n) {
2762 // Load/store to instance's field
2763 memnode_worklist.append_if_missing(use);
2764 } else if (use->is_MemBar()) {
2765 memnode_worklist.append_if_missing(use);
2766 } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
2767 Node* addp2 = find_second_addp(use, n);
2768 if (addp2 != NULL) {
2769 alloc_worklist.append_if_missing(addp2);
2770 }
2771 alloc_worklist.append_if_missing(use);
2772 } else if (use->is_Phi() ||
2773 use->is_CheckCastPP() ||
2774 use->is_EncodeP() ||
2775 use->is_DecodeN() ||
2776 (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
2777 alloc_worklist.append_if_missing(use);
2778 #ifdef ASSERT
2779 } else if (use->is_Mem()) {
2780 assert(use->in(MemNode::Address) != n, "EA: missing allocation reference path");
2781 } else if (use->is_MergeMem()) {
2782 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
2783 } else if (use->is_SafePoint()) {
2784 // Look for MergeMem nodes for calls which reference unique allocation
2785 // (through CheckCastPP nodes) even for debug info.
2786 Node* m = use->in(TypeFunc::Memory);
2787 if (m->is_MergeMem()) {
2788 assert(_mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
2789 }
2790 } else {
2791 uint op = use->Opcode();
2792 if (!(op == Op_CmpP || op == Op_Conv2B ||
2793 op == Op_CastP2X || op == Op_StoreCM ||
2794 op == Op_FastLock || op == Op_AryEq || op == Op_StrComp ||
2795 op == Op_StrEquals || op == Op_StrIndexOf)) {
2796 n->dump();
2797 use->dump();
2798 assert(false, "EA: missing allocation reference path");
2799 }
2800 #endif
2801 }
2802 }
2804 }
2805 // New alias types were created in split_AddP().
2806 uint new_index_end = (uint) _compile->num_alias_types();
2807 assert(unique_old == _compile->unique(), "there should be no new ideal nodes after Phase 1");
2809 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
2810 // compute new values for Memory inputs (the Memory inputs are not
2811 // actually updated until phase 4.)
2812 if (memnode_worklist.length() == 0)
2813 return; // nothing to do
2814 while (memnode_worklist.length() != 0) {
2815 Node *n = memnode_worklist.pop();
2816 if (visited.test_set(n->_idx))
2817 continue;
2818 if (n->is_Phi() || n->is_ClearArray()) {
2819 // we don't need to do anything, but the users must be pushed
2820 } else if (n->is_MemBar()) { // Initialize, MemBar nodes
2821 // we don't need to do anything, but the users must be pushed
2822 n = n->as_MemBar()->proj_out(TypeFunc::Memory);
2823 if (n == NULL)
2824 continue;
2825 } else {
2826 assert(n->is_Mem(), "memory node required.");
2827 Node *addr = n->in(MemNode::Address);
2828 const Type *addr_t = igvn->type(addr);
2829 if (addr_t == Type::TOP)
2830 continue;
2831 assert (addr_t->isa_ptr() != NULL, "pointer type required.");
2832 int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
2833 assert ((uint)alias_idx < new_index_end, "wrong alias index");
2834 Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis);
2835 if (_compile->failing()) {
2836 return;
2837 }
2838 if (mem != n->in(MemNode::Memory)) {
2839 // We delay the memory edge update since we need old one in
2840 // MergeMem code below when instances memory slices are separated.
2841 set_map(n, mem);
2842 }
2843 if (n->is_Load()) {
2844 continue; // don't push users
2845 } else if (n->is_LoadStore()) {
2846 // get the memory projection
2847 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2848 Node *use = n->fast_out(i);
2849 if (use->Opcode() == Op_SCMemProj) {
2850 n = use;
2851 break;
2852 }
2853 }
2854 assert(n->Opcode() == Op_SCMemProj, "memory projection required");
2855 }
2856 }
2857 // push user on appropriate worklist
2858 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2859 Node *use = n->fast_out(i);
2860 if (use->is_Phi() || use->is_ClearArray()) {
2861 memnode_worklist.append_if_missing(use);
2862 } else if(use->is_Mem() && use->in(MemNode::Memory) == n) {
2863 if (use->Opcode() == Op_StoreCM) // Ignore cardmark stores
2864 continue;
2865 memnode_worklist.append_if_missing(use);
2866 } else if (use->is_MemBar()) {
2867 memnode_worklist.append_if_missing(use);
2868 #ifdef ASSERT
2869 } else if(use->is_Mem()) {
2870 assert(use->in(MemNode::Memory) != n, "EA: missing memory path");
2871 } else if (use->is_MergeMem()) {
2872 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
2873 } else {
2874 uint op = use->Opcode();
2875 if (!(op == Op_StoreCM ||
2876 (op == Op_CallLeaf && use->as_CallLeaf()->_name != NULL &&
2877 strcmp(use->as_CallLeaf()->_name, "g1_wb_pre") == 0) ||
2878 op == Op_AryEq || op == Op_StrComp ||
2879 op == Op_StrEquals || op == Op_StrIndexOf)) {
2880 n->dump();
2881 use->dump();
2882 assert(false, "EA: missing memory path");
2883 }
2884 #endif
2885 }
2886 }
2887 }
2889 // Phase 3: Process MergeMem nodes from mergemem_worklist.
2890 // Walk each memory slice moving the first node encountered of each
2891 // instance type to the the input corresponding to its alias index.
2892 uint length = _mergemem_worklist.length();
2893 for( uint next = 0; next < length; ++next ) {
2894 MergeMemNode* nmm = _mergemem_worklist.at(next);
2895 assert(!visited.test_set(nmm->_idx), "should not be visited before");
2896 // Note: we don't want to use MergeMemStream here because we only want to
2897 // scan inputs which exist at the start, not ones we add during processing.
2898 // Note 2: MergeMem may already contains instance memory slices added
2899 // during find_inst_mem() call when memory nodes were processed above.
2900 igvn->hash_delete(nmm);
2901 uint nslices = nmm->req();
2902 for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) {
2903 Node* mem = nmm->in(i);
2904 Node* cur = NULL;
2905 if (mem == NULL || mem->is_top())
2906 continue;
2907 // First, update mergemem by moving memory nodes to corresponding slices
2908 // if their type became more precise since this mergemem was created.
2909 while (mem->is_Mem()) {
2910 const Type *at = igvn->type(mem->in(MemNode::Address));
2911 if (at != Type::TOP) {
2912 assert (at->isa_ptr() != NULL, "pointer type required.");
2913 uint idx = (uint)_compile->get_alias_index(at->is_ptr());
2914 if (idx == i) {
2915 if (cur == NULL)
2916 cur = mem;
2917 } else {
2918 if (idx >= nmm->req() || nmm->is_empty_memory(nmm->in(idx))) {
2919 nmm->set_memory_at(idx, mem);
2920 }
2921 }
2922 }
2923 mem = mem->in(MemNode::Memory);
2924 }
2925 nmm->set_memory_at(i, (cur != NULL) ? cur : mem);
2926 // Find any instance of the current type if we haven't encountered
2927 // already a memory slice of the instance along the memory chain.
2928 for (uint ni = new_index_start; ni < new_index_end; ni++) {
2929 if((uint)_compile->get_general_index(ni) == i) {
2930 Node *m = (ni >= nmm->req()) ? nmm->empty_memory() : nmm->in(ni);
2931 if (nmm->is_empty_memory(m)) {
2932 Node* result = find_inst_mem(mem, ni, orig_phis);
2933 if (_compile->failing()) {
2934 return;
2935 }
2936 nmm->set_memory_at(ni, result);
2937 }
2938 }
2939 }
2940 }
2941 // Find the rest of instances values
2942 for (uint ni = new_index_start; ni < new_index_end; ni++) {
2943 const TypeOopPtr *tinst = _compile->get_adr_type(ni)->isa_oopptr();
2944 Node* result = step_through_mergemem(nmm, ni, tinst);
2945 if (result == nmm->base_memory()) {
2946 // Didn't find instance memory, search through general slice recursively.
2947 result = nmm->memory_at(_compile->get_general_index(ni));
2948 result = find_inst_mem(result, ni, orig_phis);
2949 if (_compile->failing()) {
2950 return;
2951 }
2952 nmm->set_memory_at(ni, result);
2953 }
2954 }
2955 igvn->hash_insert(nmm);
2956 record_for_optimizer(nmm);
2957 }
2959 // Phase 4: Update the inputs of non-instance memory Phis and
2960 // the Memory input of memnodes
2961 // First update the inputs of any non-instance Phi's from
2962 // which we split out an instance Phi. Note we don't have
2963 // to recursively process Phi's encounted on the input memory
2964 // chains as is done in split_memory_phi() since they will
2965 // also be processed here.
2966 for (int j = 0; j < orig_phis.length(); j++) {
2967 PhiNode *phi = orig_phis.at(j);
2968 int alias_idx = _compile->get_alias_index(phi->adr_type());
2969 igvn->hash_delete(phi);
2970 for (uint i = 1; i < phi->req(); i++) {
2971 Node *mem = phi->in(i);
2972 Node *new_mem = find_inst_mem(mem, alias_idx, orig_phis);
2973 if (_compile->failing()) {
2974 return;
2975 }
2976 if (mem != new_mem) {
2977 phi->set_req(i, new_mem);
2978 }
2979 }
2980 igvn->hash_insert(phi);
2981 record_for_optimizer(phi);
2982 }
2984 // Update the memory inputs of MemNodes with the value we computed
2985 // in Phase 2 and move stores memory users to corresponding memory slices.
2986 // Disable memory split verification code until the fix for 6984348.
2987 // Currently it produces false negative results since it does not cover all cases.
2988 #if 0 // ifdef ASSERT
2989 visited.Reset();
2990 Node_Stack old_mems(arena, _compile->unique() >> 2);
2991 #endif
2992 for (uint i = 0; i < ideal_nodes.size(); i++) {
2993 Node* n = ideal_nodes.at(i);
2994 Node* nmem = get_map(n->_idx);
2995 assert(nmem != NULL, "sanity");
2996 if (n->is_Mem()) {
2997 #if 0 // ifdef ASSERT
2998 Node* old_mem = n->in(MemNode::Memory);
2999 if (!visited.test_set(old_mem->_idx)) {
3000 old_mems.push(old_mem, old_mem->outcnt());
3001 }
3002 #endif
3003 assert(n->in(MemNode::Memory) != nmem, "sanity");
3004 if (!n->is_Load()) {
3005 // Move memory users of a store first.
3006 move_inst_mem(n, orig_phis);
3007 }
3008 // Now update memory input
3009 igvn->hash_delete(n);
3010 n->set_req(MemNode::Memory, nmem);
3011 igvn->hash_insert(n);
3012 record_for_optimizer(n);
3013 } else {
3014 assert(n->is_Allocate() || n->is_CheckCastPP() ||
3015 n->is_AddP() || n->is_Phi(), "unknown node used for set_map()");
3016 }
3017 }
3018 #if 0 // ifdef ASSERT
3019 // Verify that memory was split correctly
3020 while (old_mems.is_nonempty()) {
3021 Node* old_mem = old_mems.node();
3022 uint old_cnt = old_mems.index();
3023 old_mems.pop();
3024 assert(old_cnt == old_mem->outcnt(), "old mem could be lost");
3025 }
3026 #endif
3027 }
3029 #ifndef PRODUCT
3030 static const char *node_type_names[] = {
3031 "UnknownType",
3032 "JavaObject",
3033 "LocalVar",
3034 "Field",
3035 "Arraycopy"
3036 };
3038 static const char *esc_names[] = {
3039 "UnknownEscape",
3040 "NoEscape",
3041 "ArgEscape",
3042 "GlobalEscape"
3043 };
3045 void PointsToNode::dump(bool print_state) const {
3046 NodeType nt = node_type();
3047 tty->print("%s ", node_type_names[(int) nt]);
3048 if (print_state) {
3049 EscapeState es = escape_state();
3050 EscapeState fields_es = fields_escape_state();
3051 tty->print("%s(%s) ", esc_names[(int)es], esc_names[(int)fields_es]);
3052 if (nt == PointsToNode::JavaObject && !this->scalar_replaceable())
3053 tty->print("NSR");
3054 }
3055 if (is_Field()) {
3056 FieldNode* f = (FieldNode*)this;
3057 tty->print("(");
3058 for (BaseIterator i(f); i.has_next(); i.next()) {
3059 PointsToNode* b = i.get();
3060 tty->print(" %d%s", b->idx(),(b->is_JavaObject() ? "P" : ""));
3061 }
3062 tty->print(" )");
3063 }
3064 tty->print("[");
3065 for (EdgeIterator i(this); i.has_next(); i.next()) {
3066 PointsToNode* e = i.get();
3067 tty->print(" %d%s%s", e->idx(),(e->is_JavaObject() ? "P" : (e->is_Field() ? "F" : "")), e->is_Arraycopy() ? "cp" : "");
3068 }
3069 tty->print(" [");
3070 for (UseIterator i(this); i.has_next(); i.next()) {
3071 PointsToNode* u = i.get();
3072 bool is_base = false;
3073 if (PointsToNode::is_base_use(u)) {
3074 is_base = true;
3075 u = PointsToNode::get_use_node(u)->as_Field();
3076 }
3077 tty->print(" %d%s%s", u->idx(), is_base ? "b" : "", u->is_Arraycopy() ? "cp" : "");
3078 }
3079 tty->print(" ]] ");
3080 if (_node == NULL)
3081 tty->print_cr("<null>");
3082 else
3083 _node->dump();
3084 }
3086 void ConnectionGraph::dump(GrowableArray<PointsToNode*>& ptnodes_worklist) {
3087 bool first = true;
3088 int ptnodes_length = ptnodes_worklist.length();
3089 for (int i = 0; i < ptnodes_length; i++) {
3090 PointsToNode *ptn = ptnodes_worklist.at(i);
3091 if (ptn == NULL || !ptn->is_JavaObject())
3092 continue;
3093 PointsToNode::EscapeState es = ptn->escape_state();
3094 if (ptn->ideal_node()->is_Allocate() && (es == PointsToNode::NoEscape || Verbose)) {
3095 if (first) {
3096 tty->cr();
3097 tty->print("======== Connection graph for ");
3098 _compile->method()->print_short_name();
3099 tty->cr();
3100 first = false;
3101 }
3102 ptn->dump();
3103 // Print all locals and fields which reference this allocation
3104 for (UseIterator j(ptn); j.has_next(); j.next()) {
3105 PointsToNode* use = j.get();
3106 if (use->is_LocalVar()) {
3107 use->dump(Verbose);
3108 } else if (Verbose) {
3109 use->dump();
3110 }
3111 }
3112 tty->cr();
3113 }
3114 }
3115 }
3116 #endif