1 /*
2 * Copyright (c) 2005, 2019, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "ci/bcEscapeAnalyzer.hpp"
27 #include "compiler/compileLog.hpp"
28 #include "gc/shared/barrierSet.hpp"
29 #include "gc/shared/c2/barrierSetC2.hpp"
30 #include "libadt/vectset.hpp"
31 #include "memory/allocation.hpp"
32 #include "memory/resourceArea.hpp"
33 #include "opto/c2compiler.hpp"
34 #include "opto/arraycopynode.hpp"
35 #include "opto/callnode.hpp"
36 #include "opto/cfgnode.hpp"
37 #include "opto/compile.hpp"
38 #include "opto/escape.hpp"
39 #include "opto/phaseX.hpp"
40 #include "opto/movenode.hpp"
41 #include "opto/rootnode.hpp"
42 #include "utilities/macros.hpp"
43
44 ConnectionGraph::ConnectionGraph(Compile * C, PhaseIterGVN *igvn) :
45 _nodes(C->comp_arena(), C->unique(), C->unique(), NULL),
46 _in_worklist(C->comp_arena()),
47 _next_pidx(0),
48 _collecting(true),
49 _verify(false),
50 _has_locks(false),
51 _compile(C),
52 _igvn(igvn),
53 _node_map(C->comp_arena()) {
54 // Add unknown java object.
55 add_java_object(C->top(), PointsToNode::GlobalEscape);
56 phantom_obj = ptnode_adr(C->top()->_idx)->as_JavaObject();
57 // Add ConP(#NULL) and ConN(#NULL) nodes.
58 Node* oop_null = igvn->zerocon(T_OBJECT);
59 assert(oop_null->_idx < nodes_size(), "should be created already");
60 add_java_object(oop_null, PointsToNode::NoEscape);
61 null_obj = ptnode_adr(oop_null->_idx)->as_JavaObject();
62 if (UseCompressedOops) {
63 Node* noop_null = igvn->zerocon(T_NARROWOOP);
64 assert(noop_null->_idx < nodes_size(), "should be created already");
65 map_ideal_node(noop_null, null_obj);
66 }
67 _pcmp_neq = NULL; // Should be initialized
68 _pcmp_eq = NULL;
69 }
70
71 bool ConnectionGraph::has_candidates(Compile *C) {
72 // EA brings benefits only when the code has allocations and/or locks which
73 // are represented by ideal Macro nodes.
74 int cnt = C->macro_count();
75 for (int i = 0; i < cnt; i++) {
76 Node *n = C->macro_node(i);
77 if (n->is_Allocate())
78 return true;
79 if (n->is_Lock()) {
80 Node* obj = n->as_Lock()->obj_node()->uncast();
81 if (!(obj->is_Parm() || obj->is_Con()))
82 return true;
83 }
84 if (n->is_CallStaticJava() &&
85 n->as_CallStaticJava()->is_boxing_method()) {
86 return true;
87 }
88 }
89 return false;
90 }
91
92 void ConnectionGraph::do_analysis(Compile *C, PhaseIterGVN *igvn) {
93 Compile::TracePhase tp("escapeAnalysis", &Phase::timers[Phase::_t_escapeAnalysis]);
94 ResourceMark rm;
95
96 // Add ConP#NULL and ConN#NULL nodes before ConnectionGraph construction
97 // to create space for them in ConnectionGraph::_nodes[].
98 Node* oop_null = igvn->zerocon(T_OBJECT);
99 Node* noop_null = igvn->zerocon(T_NARROWOOP);
100 ConnectionGraph* congraph = new(C->comp_arena()) ConnectionGraph(C, igvn);
101 // Perform escape analysis
102 if (congraph->compute_escape()) {
103 // There are non escaping objects.
104 C->set_congraph(congraph);
105 }
106 // Cleanup.
107 if (oop_null->outcnt() == 0)
108 igvn->hash_delete(oop_null);
109 if (noop_null->outcnt() == 0)
110 igvn->hash_delete(noop_null);
111 }
112
113 bool ConnectionGraph::compute_escape() {
114 Compile* C = _compile;
115 PhaseGVN* igvn = _igvn;
116
117 // Worklists used by EA.
118 Unique_Node_List delayed_worklist;
119 GrowableArray<Node*> alloc_worklist;
120 GrowableArray<Node*> ptr_cmp_worklist;
121 GrowableArray<Node*> storestore_worklist;
122 GrowableArray<ArrayCopyNode*> arraycopy_worklist;
123 GrowableArray<PointsToNode*> ptnodes_worklist;
124 GrowableArray<JavaObjectNode*> java_objects_worklist;
125 GrowableArray<JavaObjectNode*> non_escaped_worklist;
126 GrowableArray<FieldNode*> oop_fields_worklist;
127 DEBUG_ONLY( GrowableArray<Node*> addp_worklist; )
128
129 { Compile::TracePhase tp("connectionGraph", &Phase::timers[Phase::_t_connectionGraph]);
130
131 // 1. Populate Connection Graph (CG) with PointsTo nodes.
132 ideal_nodes.map(C->live_nodes(), NULL); // preallocate space
133 // Initialize worklist
134 if (C->root() != NULL) {
135 ideal_nodes.push(C->root());
136 }
137 // Processed ideal nodes are unique on ideal_nodes list
138 // but several ideal nodes are mapped to the phantom_obj.
139 // To avoid duplicated entries on the following worklists
140 // add the phantom_obj only once to them.
141 ptnodes_worklist.append(phantom_obj);
142 java_objects_worklist.append(phantom_obj);
143 for( uint next = 0; next < ideal_nodes.size(); ++next ) {
144 Node* n = ideal_nodes.at(next);
145 // Create PointsTo nodes and add them to Connection Graph. Called
146 // only once per ideal node since ideal_nodes is Unique_Node list.
147 add_node_to_connection_graph(n, &delayed_worklist);
148 PointsToNode* ptn = ptnode_adr(n->_idx);
149 if (ptn != NULL && ptn != phantom_obj) {
150 ptnodes_worklist.append(ptn);
151 if (ptn->is_JavaObject()) {
152 java_objects_worklist.append(ptn->as_JavaObject());
153 if ((n->is_Allocate() || n->is_CallStaticJava()) &&
154 (ptn->escape_state() < PointsToNode::GlobalEscape)) {
155 // Only allocations and java static calls results are interesting.
156 non_escaped_worklist.append(ptn->as_JavaObject());
157 }
158 } else if (ptn->is_Field() && ptn->as_Field()->is_oop()) {
159 oop_fields_worklist.append(ptn->as_Field());
160 }
161 }
162 if (n->is_MergeMem()) {
163 // Collect all MergeMem nodes to add memory slices for
164 // scalar replaceable objects in split_unique_types().
165 _mergemem_worklist.append(n->as_MergeMem());
166 } else if (OptimizePtrCompare && n->is_Cmp() &&
167 (n->Opcode() == Op_CmpP || n->Opcode() == Op_CmpN)) {
168 // Collect compare pointers nodes.
169 ptr_cmp_worklist.append(n);
170 } else if (n->is_MemBarStoreStore()) {
171 // Collect all MemBarStoreStore nodes so that depending on the
172 // escape status of the associated Allocate node some of them
173 // may be eliminated.
174 storestore_worklist.append(n);
175 } else if (n->is_MemBar() && (n->Opcode() == Op_MemBarRelease) &&
176 (n->req() > MemBarNode::Precedent)) {
177 record_for_optimizer(n);
178 #ifdef ASSERT
179 } else if (n->is_AddP()) {
180 // Collect address nodes for graph verification.
181 addp_worklist.append(n);
182 #endif
183 } else if (n->is_ArrayCopy()) {
184 // Keep a list of ArrayCopy nodes so if one of its input is non
185 // escaping, we can record a unique type
186 arraycopy_worklist.append(n->as_ArrayCopy());
187 } else if (n->is_Lock()) {
188 Node* obj = n->as_Lock()->obj_node()->uncast();
189 if (!(obj->is_Parm() || obj->is_Con())) {
190 _has_locks = true;
191 }
192 }
193 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
194 Node* m = n->fast_out(i); // Get user
195 ideal_nodes.push(m);
196 }
197 }
198 if (non_escaped_worklist.length() == 0) {
199 _collecting = false;
200 return false; // Nothing to do.
201 }
202 // Add final simple edges to graph.
203 while(delayed_worklist.size() > 0) {
204 Node* n = delayed_worklist.pop();
205 add_final_edges(n);
206 }
207 int ptnodes_length = ptnodes_worklist.length();
208
209 #ifdef ASSERT
210 if (VerifyConnectionGraph) {
211 // Verify that no new simple edges could be created and all
212 // local vars has edges.
213 _verify = true;
214 for (int next = 0; next < ptnodes_length; ++next) {
215 PointsToNode* ptn = ptnodes_worklist.at(next);
216 add_final_edges(ptn->ideal_node());
217 if (ptn->is_LocalVar() && ptn->edge_count() == 0) {
218 ptn->dump();
219 assert(ptn->as_LocalVar()->edge_count() > 0, "sanity");
220 }
221 }
222 _verify = false;
223 }
224 #endif
225 // Bytecode analyzer BCEscapeAnalyzer, used for Call nodes
226 // processing, calls to CI to resolve symbols (types, fields, methods)
227 // referenced in bytecode. During symbol resolution VM may throw
228 // an exception which CI cleans and converts to compilation failure.
229 if (C->failing()) return false;
230
231 // 2. Finish Graph construction by propagating references to all
232 // java objects through graph.
233 if (!complete_connection_graph(ptnodes_worklist, non_escaped_worklist,
234 java_objects_worklist, oop_fields_worklist)) {
235 // All objects escaped or hit time or iterations limits.
236 _collecting = false;
237 return false;
238 }
239
240 // 3. Adjust scalar_replaceable state of nonescaping objects and push
241 // scalar replaceable allocations on alloc_worklist for processing
242 // in split_unique_types().
243 int non_escaped_length = non_escaped_worklist.length();
244 for (int next = 0; next < non_escaped_length; next++) {
245 JavaObjectNode* ptn = non_escaped_worklist.at(next);
246 bool noescape = (ptn->escape_state() == PointsToNode::NoEscape);
247 Node* n = ptn->ideal_node();
248 if (n->is_Allocate()) {
249 n->as_Allocate()->_is_non_escaping = noescape;
250 }
251 if (n->is_CallStaticJava()) {
252 n->as_CallStaticJava()->_is_non_escaping = noescape;
253 }
254 if (noescape && ptn->scalar_replaceable()) {
255 adjust_scalar_replaceable_state(ptn);
256 if (ptn->scalar_replaceable()) {
257 alloc_worklist.append(ptn->ideal_node());
258 }
259 } else {
260 // Set scalar replaceable to false to for stack allocation analysis below
261 ptn->set_scalar_replaceable(false);
262 }
263 }
264
265 // 4. Perform stack allocation analysis
266 if (C->do_stack_allocation() && (!_has_locks || (EliminateLocks && EliminateNestedLocks))) {
267 if (non_escaped_length > 0) {
268 for (int next = 0; next < non_escaped_length; next++) {
269 JavaObjectNode* ptn = non_escaped_worklist.at(next);
270 PointsToNode::EscapeState es = ptn->escape_state();
271 assert(es < PointsToNode::GlobalEscape, "list can not contain GlobalEscape objects");
272 if (es == PointsToNode::ArgEscape) {
273 #ifndef PRODUCT
274 if (print_escape_analysis() || print_stack_allocation()) {
275 tty->print_cr("---- Alloc node %d can not be stack allocated as it escapes as an argument", ptn->ideal_node()->_idx);
276 }
277 #endif
278 continue;
279 }
280
281 Node* n = ptn->ideal_node();
282 if (!n->is_Allocate()) {
283 continue;
284 }
285
286 n->as_Allocate()->_is_stack_allocateable = eligible_for_stack_allocation(ptn);
287 }
288 }
289
290 // 4.1 Verify that object chains don't contain heap objects pointing
291 // to stack allocated objects. Loop until there are changes in the
292 // state of which objects are allowed to be stack allocated.
293 bool more_work = non_escaped_length > 0;
294 while (more_work) {
295 more_work = verify_stack_allocated_object_chains(non_escaped_worklist, non_escaped_length);
296 }
297
298 #ifndef PRODUCT
299 if (print_escape_analysis() || print_stack_allocation()) {
300 print_stack_allocated_candidates(non_escaped_worklist, non_escaped_length);
301 }
302 #endif
303 }
304
305 #ifdef ASSERT
306 if (VerifyConnectionGraph) {
307 // Verify that graph is complete - no new edges could be added or needed.
308 verify_connection_graph(ptnodes_worklist, non_escaped_worklist,
309 java_objects_worklist, addp_worklist);
310 }
311 assert(C->unique() == nodes_size(), "no new ideal nodes should be added during ConnectionGraph build");
312 assert(null_obj->escape_state() == PointsToNode::NoEscape &&
313 null_obj->edge_count() == 0 &&
314 !null_obj->arraycopy_src() &&
315 !null_obj->arraycopy_dst(), "sanity");
316 #endif
317
318 _collecting = false;
319
320 } // TracePhase t3("connectionGraph")
321
322 // 5. Optimize ideal graph based on EA information.
323 bool has_non_escaping_obj = (non_escaped_worklist.length() > 0);
324 if (has_non_escaping_obj) {
325 optimize_ideal_graph(ptr_cmp_worklist, storestore_worklist);
326 }
327
328 #ifndef PRODUCT
329 if (print_escape_analysis()) {
330 dump(ptnodes_worklist); // Dump ConnectionGraph
331 }
332 #endif
333
334 bool has_scalar_replaceable_candidates = (alloc_worklist.length() > 0);
335 #ifdef ASSERT
336 if (VerifyConnectionGraph) {
337 int alloc_length = alloc_worklist.length();
338 for (int next = 0; next < alloc_length; ++next) {
339 Node* n = alloc_worklist.at(next);
340 PointsToNode* ptn = ptnode_adr(n->_idx);
341 assert(ptn->escape_state() == PointsToNode::NoEscape && ptn->scalar_replaceable(), "sanity");
342 }
343 }
344 #endif
345
346 // 6. Separate memory graph for scalar replaceable allcations.
347 if (has_scalar_replaceable_candidates &&
348 C->AliasLevel() >= 3 && EliminateAllocations) {
349 // Now use the escape information to create unique types for
350 // scalar replaceable objects.
351 split_unique_types(alloc_worklist, arraycopy_worklist);
352 if (C->failing()) return false;
353 C->print_method(PHASE_AFTER_EA, 2);
354
355 #ifdef ASSERT
356 } else if (Verbose && (print_escape_analysis() || print_eliminate_allocations())) {
357 tty->print("=== No allocations eliminated for ");
358 C->method()->print_short_name();
359 if(!EliminateAllocations) {
360 tty->print(" since EliminateAllocations is off ===");
361 } else if(!has_scalar_replaceable_candidates) {
362 tty->print(" since there are no scalar replaceable candidates ===");
363 } else if(C->AliasLevel() < 3) {
364 tty->print(" since AliasLevel < 3 ===");
365 }
366 tty->cr();
367 #endif
368 }
369 return has_non_escaping_obj;
370 }
371
372 // If an allocation is dominated by a loop, check to see if the lifetime of two instances
373 // may overlap. If they do this allocate is not eligible for stack allocation
374 bool ConnectionGraph::allocation_lifetime_overlap(AllocateNode *alloc, PhiNode *phi) {
375 Node *child0 = phi->in(0);
376 if (!child0->is_Loop()) {
377 return false;
378 }
379 // This is very pessimistic... but correct. It could be optimized
380 VectorSet visited(Thread::current()->resource_area());
381 GrowableArray<Node*> node_worklist;
382
383 for (uint i = 1; i < phi->outcnt(); i++) {
384 node_worklist.push(phi->raw_out(i));
385 }
386
387 while(node_worklist.length() != 0) {
388 Node* node = node_worklist.pop();
389 if (visited.test_set(node->_idx)) {
390 continue; // already processed
391 }
392
393 if (node->is_Phi()) {
394 if (phi == node) {
395 return true;
396 }
397 }
398 for (DUIterator_Fast imax, i = node->fast_outs(imax); i < imax; i++) {
399 node_worklist.push(node->fast_out(i));
400 }
401 }
402 return false;
403 }
404
405 // Find if an allocate result may reach an EncodeP
406 bool ConnectionGraph::oop_may_be_compressed(Node* alloc_result) {
407 VectorSet visited(Thread::current()->resource_area());
408 GrowableArray<Node*> node_worklist;
409
410 node_worklist.push(alloc_result);
411 visited.set(alloc_result->_idx);
412
413 while(node_worklist.length() != 0) {
414 Node* node = node_worklist.pop();
415
416 for (DUIterator_Fast imax, i = node->fast_outs(imax); i < imax; i++) {
417 Node *use = node->fast_out(i);
418 if (use->is_Phi()) {
419 if (!visited.test_set(use->_idx)) {
420 node_worklist.push(use);
421 }
422 } else if (use->is_EncodeP()) {
423 return true;
424 }
425 }
426 }
427
428 return false;
429 }
430
431 // Various checks to determine if an alloc is a candidate for stack allocation
432 bool ConnectionGraph::eligible_for_stack_allocation(PointsToNode* ptn) {
433 assert(ptn->ideal_node()->is_Allocate(), "Must be called on allocate or allocate array node");
434
435 AllocateNode *alloc = ptn->ideal_node()->as_Allocate();
436 Node* res = alloc->result_cast();
437 if (res == NULL) {
438 #ifndef PRODUCT
439 if (print_escape_analysis() || print_stack_allocation()) {
440 tty->print_cr("---- Alloc node %d can not be stack allocated due to NULL result_cast", alloc->_idx);
441 }
442 #endif
443 return false;
444 } else if (!res->is_CheckCastPP()) {
445 #ifndef PRODUCT
446 if (print_escape_analysis() || print_stack_allocation()) {
447 tty->print_cr("---- Alloc node %d can not be stack allocated due to an invalid result_cast", alloc->_idx);
448 }
449 #endif
450 return false;
451 }
452
453 Node* size_in_bytes = alloc->in(AllocateNode::AllocSize);
454 intptr_t size_of_object = _igvn->find_intptr_t_con(size_in_bytes, -1);
455 if ((size_of_object == -1) || (size_of_object > AllocateNode::StackAllocSizeLimit)) {
456 // Object has unknown size or is too big so it can not be stack allocated.
457 // No need to find reaching objects since it does not have any fields
458 #ifndef PRODUCT
459 if (print_escape_analysis() || print_stack_allocation()) {
460 tty->print_cr("---- Alloc node %d can not be stack allocated due to an invalid size", alloc->_idx);
461 }
462 #endif
463 return false;
464 }
465
466 if (alloc->is_AllocateArray()) {
467 int length = alloc->in(AllocateNode::ALength)->find_int_con(-1);
468 if (length < 0 || length > EliminateAllocationArraySizeLimit) {
469 // Array does not have a constant length so it can not be stack allocated
470 #ifndef PRODUCT
471 if (print_escape_analysis() || print_stack_allocation()) {
472 tty->print_cr("---- Alloc node %d can not be stack allocated as it is an array with an invalid length", alloc->_idx);
473 }
474 #endif
475 return false;
476 }
477 }
478
479 if (UseCompressedOops && oop_may_be_compressed(res)) {
480 #ifndef PRODUCT
481 if (print_escape_analysis() || print_stack_allocation()) {
482 tty->print_cr("---- Alloc node %d can not be stack allocated due to compress operation on the stack oop", alloc->_idx);
483 }
484 #endif
485 return false;
486 }
487
488 return all_uses_eligible_for_stack_allocation(ptn);
489 }
490
491 // Check if the alloc has uses that make it ineligible for stack allocation
492 bool ConnectionGraph::all_uses_eligible_for_stack_allocation(PointsToNode *ptn) {
493 assert(ptn->ideal_node()->is_Allocate(), "Must be called on allocate or allocate array node");
494
495 AllocateNode *alloc = ptn->ideal_node()->as_Allocate();
496 Node* res = alloc->result_cast();
497
498 assert(res != NULL, "Result cast must not be NULL at this point");
499
500 for (int uses = 0; uses < ptn->use_count(); uses ++) {
501 PointsToNode *use = ptn->use(uses);
502 if (use->is_LocalVar()) {
503 LocalVarNode *local = use->as_LocalVar();
504 Node *node = local->ideal_node();
505 if (node->is_Phi()) {
506 if (allocation_lifetime_overlap(alloc, node->as_Phi())) {
507 #ifndef PRODUCT
508 if (print_escape_analysis() || print_stack_allocation()) {
509 tty->print_cr("---- Alloc node %d can not be stack allocated as it may overlap with older versions of itself", alloc->_idx);
510 }
511 #endif
512 return false;
513 }
514 } else if (node->is_Load() && node->Opcode() == Op_LoadP) {
515 Node *in1 = node->in(1);
516 if ((in1 != NULL) && in1->is_Phi()) {
517 if (allocation_lifetime_overlap(alloc, in1->as_Phi())) {
518 #ifndef PRODUCT
519 if (print_escape_analysis() || print_stack_allocation()) {
520 tty->print_cr("---- Alloc node %d can not be stack allocated as it may overlap with older versions of itself", alloc->_idx);
521 }
522 #endif
523 return false;
524 }
525 }
526 }
527 } else if (use->is_Field()) {
528 if (UseCompressedOops) {
529 #ifndef PRODUCT
530 if (print_escape_analysis() || print_stack_allocation()) {
531 tty->print_cr("---- Alloc node %d can not be stack allocated as it referenced by another object", alloc->_idx);
532 }
533 #endif
534 return false;
535 }
536 } else if (use->is_Arraycopy()) {
537 if (ptn->arraycopy_dst() && alloc->is_AllocateArray()) {
538 Node* klass = alloc->in(AllocateNode::KlassNode);
539 ciKlass* k = _igvn->type(klass)->is_klassptr()->klass();
540 if (k->is_obj_array_klass()) {
541 // The System.arraycopy helper has a post store barrier which does not handle stack allocated objects
542 #ifndef PRODUCT
543 if (print_escape_analysis() || print_stack_allocation()) {
544 tty->print_cr("---- Alloc node %d can not be stack allocated as it is referenced from an arraycopy", alloc->_idx);
545 }
546 #endif
547 return false;
548 }
549 }
550 }
551 }
552
553 return true;
554 }
555
556 bool ConnectionGraph::verify_stack_allocated_object_chains(GrowableArray<JavaObjectNode*> &non_escaped_worklist, int non_escaped_length) {
557 for (int next = 0; next < non_escaped_length; next++) {
558 JavaObjectNode* ptn = non_escaped_worklist.at(next);
559 if (ptn->escape_state() != PointsToNode::NoEscape) {
560 continue;
561 }
562 Node* n = ptn->ideal_node();
563 if (!n->is_Allocate()) {
564 continue;
565 }
566 AllocateNode *alloc = n->as_Allocate();
567 if (!alloc->_is_stack_allocateable) {
568 continue;
569 }
570 for (int uses = 0; uses < ptn->use_count(); uses ++) {
571 PointsToNode *use = ptn->use(uses);
572 if(use->is_Field()) {
573 for (BaseIterator i(use->as_Field()); i.has_next(); i.next()) {
574 PointsToNode* base = i.get();
575 if (base->is_JavaObject()) {
576 JavaObjectNode *new_obj = base->as_JavaObject();
577 if (new_obj == ptn) {
578 continue;
579 }
580 if (!new_obj->ideal_node()->is_Allocate()) {
581 if (new_obj->ideal_node()->Opcode() == Op_ConP) {
582 TypeNode *tn = new_obj->ideal_node()->as_Type();
583 if (tn->type() == TypePtr::NULL_PTR) {
584 // Allow NULL ptr ConP
585 continue;
586 }
587 }
588 alloc->_is_stack_allocateable = false;
589 alloc->_is_referenced_stack_allocation = false;
590 #ifndef PRODUCT
591 if (print_escape_analysis() || print_stack_allocation()) {
592 tty->print_cr("---- Alloc node %d can not be stack allocated, it is referenced by a non allocate object", alloc->_idx);
593 }
594 #endif
595 return true;
596 }
597 AllocateNode *new_alloc = new_obj->ideal_node()->as_Allocate();
598 if (!new_alloc->_is_stack_allocateable && !new_obj->scalar_replaceable()) {
599 alloc->_is_stack_allocateable = false;
600 alloc->_is_referenced_stack_allocation = false;
601 #ifndef PRODUCT
602 if (print_escape_analysis() || print_stack_allocation()) {
603 tty->print_cr("---- Alloc node %d can not be stack allocated, it is referenced by another non SCR/SA object %d", alloc->_idx, new_alloc->_idx);
604 }
605 #endif
606 return true;
607 } else {
608 assert(alloc->_is_stack_allocateable, "has to be stack allocateable");
609 alloc->_is_referenced_stack_allocation = true;
610 }
611 }
612 }
613 }
614 }
615 }
616
617 return false;
618 }
619
620 #ifndef PRODUCT
621 void ConnectionGraph::print_stack_allocated_candidates(GrowableArray<JavaObjectNode*> &non_escaped_worklist, int non_escaped_length) {
622 for (int next = 0; next < non_escaped_length; next++) {
623 JavaObjectNode* ptn = non_escaped_worklist.at(next);
624 Node* n = ptn->ideal_node();
625 if (!n->is_Allocate()) {
626 continue;
627 }
628 AllocateNode *alloc = n->as_Allocate();
629 if (alloc->_is_stack_allocateable) {
630 tty->print_cr("++++ Alloc node %d is marked as stack allocateable is_scalar_replaceable (%d)", n->_idx, ptn->scalar_replaceable());
631 }
632 }
633 }
634 #endif
635
636 // Utility function for nodes that load an object
637 void ConnectionGraph::add_objload_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
638 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
639 // ThreadLocal has RawPtr type.
640 const Type* t = _igvn->type(n);
641 if (t->make_ptr() != NULL) {
642 Node* adr = n->in(MemNode::Address);
643 #ifdef ASSERT
644 if (!adr->is_AddP()) {
645 assert(_igvn->type(adr)->isa_rawptr(), "sanity");
646 } else {
647 assert((ptnode_adr(adr->_idx) == NULL ||
648 ptnode_adr(adr->_idx)->as_Field()->is_oop()), "sanity");
649 }
650 #endif
651 add_local_var_and_edge(n, PointsToNode::NoEscape,
652 adr, delayed_worklist);
653 }
654 }
655
656 // Populate Connection Graph with PointsTo nodes and create simple
657 // connection graph edges.
658 void ConnectionGraph::add_node_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
659 assert(!_verify, "this method should not be called for verification");
660 PhaseGVN* igvn = _igvn;
661 uint n_idx = n->_idx;
662 PointsToNode* n_ptn = ptnode_adr(n_idx);
663 if (n_ptn != NULL)
664 return; // No need to redefine PointsTo node during first iteration.
665
666 int opcode = n->Opcode();
667 bool gc_handled = BarrierSet::barrier_set()->barrier_set_c2()->escape_add_to_con_graph(this, igvn, delayed_worklist, n, opcode);
668 if (gc_handled) {
669 return; // Ignore node if already handled by GC.
670 }
671
672 if (n->is_Call()) {
673 // Arguments to allocation and locking don't escape.
674 if (n->is_AbstractLock()) {
675 // Put Lock and Unlock nodes on IGVN worklist to process them during
676 // first IGVN optimization when escape information is still available.
677 record_for_optimizer(n);
678 } else if (n->is_Allocate()) {
679 add_call_node(n->as_Call());
680 record_for_optimizer(n);
681 } else {
682 if (n->is_CallStaticJava()) {
683 const char* name = n->as_CallStaticJava()->_name;
684 if (name != NULL && strcmp(name, "uncommon_trap") == 0)
685 return; // Skip uncommon traps
686 }
687 // Don't mark as processed since call's arguments have to be processed.
688 delayed_worklist->push(n);
689 // Check if a call returns an object.
690 if ((n->as_Call()->returns_pointer() &&
691 n->as_Call()->proj_out_or_null(TypeFunc::Parms) != NULL) ||
692 (n->is_CallStaticJava() &&
693 n->as_CallStaticJava()->is_boxing_method())) {
694 add_call_node(n->as_Call());
695 }
696 }
697 return;
698 }
699 // Put this check here to process call arguments since some call nodes
700 // point to phantom_obj.
701 if (n_ptn == phantom_obj || n_ptn == null_obj)
702 return; // Skip predefined nodes.
703
704 switch (opcode) {
705 case Op_AddP: {
706 Node* base = get_addp_base(n);
707 PointsToNode* ptn_base = ptnode_adr(base->_idx);
708 // Field nodes are created for all field types. They are used in
709 // adjust_scalar_replaceable_state() and split_unique_types().
710 // Note, non-oop fields will have only base edges in Connection
711 // Graph because such fields are not used for oop loads and stores.
712 int offset = address_offset(n, igvn);
713 add_field(n, PointsToNode::NoEscape, offset);
714 if (ptn_base == NULL) {
715 delayed_worklist->push(n); // Process it later.
716 } else {
717 n_ptn = ptnode_adr(n_idx);
718 add_base(n_ptn->as_Field(), ptn_base);
719 }
720 break;
721 }
722 case Op_CastX2P: {
723 map_ideal_node(n, phantom_obj);
724 break;
725 }
726 case Op_CastPP:
727 case Op_CheckCastPP:
728 case Op_EncodeP:
729 case Op_DecodeN:
730 case Op_EncodePKlass:
731 case Op_DecodeNKlass: {
732 add_local_var_and_edge(n, PointsToNode::NoEscape,
733 n->in(1), delayed_worklist);
734 break;
735 }
736 case Op_CMoveP: {
737 add_local_var(n, PointsToNode::NoEscape);
738 // Do not add edges during first iteration because some could be
739 // not defined yet.
740 delayed_worklist->push(n);
741 break;
742 }
743 case Op_ConP:
744 case Op_ConN:
745 case Op_ConNKlass: {
746 // assume all oop constants globally escape except for null
747 PointsToNode::EscapeState es;
748 const Type* t = igvn->type(n);
749 if (t == TypePtr::NULL_PTR || t == TypeNarrowOop::NULL_PTR) {
750 es = PointsToNode::NoEscape;
751 } else {
752 es = PointsToNode::GlobalEscape;
753 }
754 add_java_object(n, es);
755 break;
756 }
757 case Op_CreateEx: {
758 // assume that all exception objects globally escape
759 map_ideal_node(n, phantom_obj);
760 break;
761 }
762 case Op_LoadKlass:
763 case Op_LoadNKlass: {
764 // Unknown class is loaded
765 map_ideal_node(n, phantom_obj);
766 break;
767 }
768 case Op_LoadP:
769 case Op_LoadN:
770 case Op_LoadPLocked: {
771 add_objload_to_connection_graph(n, delayed_worklist);
772 break;
773 }
774 case Op_Parm: {
775 map_ideal_node(n, phantom_obj);
776 break;
777 }
778 case Op_PartialSubtypeCheck: {
779 // Produces Null or notNull and is used in only in CmpP so
780 // phantom_obj could be used.
781 map_ideal_node(n, phantom_obj); // Result is unknown
782 break;
783 }
784 case Op_Phi: {
785 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
786 // ThreadLocal has RawPtr type.
787 const Type* t = n->as_Phi()->type();
788 if (t->make_ptr() != NULL) {
789 add_local_var(n, PointsToNode::NoEscape);
790 // Do not add edges during first iteration because some could be
791 // not defined yet.
792 delayed_worklist->push(n);
793 }
794 break;
795 }
796 case Op_Proj: {
797 // we are only interested in the oop result projection from a call
798 if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
799 n->in(0)->as_Call()->returns_pointer()) {
800 add_local_var_and_edge(n, PointsToNode::NoEscape,
801 n->in(0), delayed_worklist);
802 }
803 break;
804 }
805 case Op_Rethrow: // Exception object escapes
806 case Op_Return: {
807 if (n->req() > TypeFunc::Parms &&
808 igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
809 // Treat Return value as LocalVar with GlobalEscape escape state.
810 add_local_var_and_edge(n, PointsToNode::GlobalEscape,
811 n->in(TypeFunc::Parms), delayed_worklist);
812 }
813 break;
814 }
815 case Op_CompareAndExchangeP:
816 case Op_CompareAndExchangeN:
817 case Op_GetAndSetP:
818 case Op_GetAndSetN: {
819 add_objload_to_connection_graph(n, delayed_worklist);
820 // fallthrough
821 }
822 case Op_StoreP:
823 case Op_StoreN:
824 case Op_StoreNKlass:
825 case Op_StorePConditional:
826 case Op_WeakCompareAndSwapP:
827 case Op_WeakCompareAndSwapN:
828 case Op_CompareAndSwapP:
829 case Op_CompareAndSwapN: {
830 add_to_congraph_unsafe_access(n, opcode, delayed_worklist);
831 break;
832 }
833 case Op_AryEq:
834 case Op_HasNegatives:
835 case Op_StrComp:
836 case Op_StrEquals:
837 case Op_StrIndexOf:
838 case Op_StrIndexOfChar:
839 case Op_StrInflatedCopy:
840 case Op_StrCompressedCopy:
841 case Op_EncodeISOArray: {
842 add_local_var(n, PointsToNode::ArgEscape);
843 delayed_worklist->push(n); // Process it later.
844 break;
845 }
846 case Op_ThreadLocal: {
847 add_java_object(n, PointsToNode::ArgEscape);
848 break;
849 }
850 default:
851 ; // Do nothing for nodes not related to EA.
852 }
853 return;
854 }
855
856 #ifdef ASSERT
857 #define ELSE_FAIL(name) \
858 /* Should not be called for not pointer type. */ \
859 n->dump(1); \
860 assert(false, name); \
861 break;
862 #else
863 #define ELSE_FAIL(name) \
864 break;
865 #endif
866
867 // Add final simple edges to graph.
868 void ConnectionGraph::add_final_edges(Node *n) {
869 PointsToNode* n_ptn = ptnode_adr(n->_idx);
870 #ifdef ASSERT
871 if (_verify && n_ptn->is_JavaObject())
872 return; // This method does not change graph for JavaObject.
873 #endif
874
875 if (n->is_Call()) {
876 process_call_arguments(n->as_Call());
877 return;
878 }
879 assert(n->is_Store() || n->is_LoadStore() ||
880 (n_ptn != NULL) && (n_ptn->ideal_node() != NULL),
881 "node should be registered already");
882 int opcode = n->Opcode();
883 bool gc_handled = BarrierSet::barrier_set()->barrier_set_c2()->escape_add_final_edges(this, _igvn, n, opcode);
884 if (gc_handled) {
885 return; // Ignore node if already handled by GC.
886 }
887 switch (opcode) {
888 case Op_AddP: {
889 Node* base = get_addp_base(n);
890 PointsToNode* ptn_base = ptnode_adr(base->_idx);
891 assert(ptn_base != NULL, "field's base should be registered");
892 add_base(n_ptn->as_Field(), ptn_base);
893 break;
894 }
895 case Op_CastPP:
896 case Op_CheckCastPP:
897 case Op_EncodeP:
898 case Op_DecodeN:
899 case Op_EncodePKlass:
900 case Op_DecodeNKlass: {
901 add_local_var_and_edge(n, PointsToNode::NoEscape,
902 n->in(1), NULL);
903 break;
904 }
905 case Op_CMoveP: {
906 for (uint i = CMoveNode::IfFalse; i < n->req(); i++) {
907 Node* in = n->in(i);
908 if (in == NULL)
909 continue; // ignore NULL
910 Node* uncast_in = in->uncast();
911 if (uncast_in->is_top() || uncast_in == n)
912 continue; // ignore top or inputs which go back this node
913 PointsToNode* ptn = ptnode_adr(in->_idx);
914 assert(ptn != NULL, "node should be registered");
915 add_edge(n_ptn, ptn);
916 }
917 break;
918 }
919 case Op_LoadP:
920 case Op_LoadN:
921 case Op_LoadPLocked: {
922 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
923 // ThreadLocal has RawPtr type.
924 const Type* t = _igvn->type(n);
925 if (t->make_ptr() != NULL) {
926 Node* adr = n->in(MemNode::Address);
927 add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
928 break;
929 }
930 ELSE_FAIL("Op_LoadP");
931 }
932 case Op_Phi: {
933 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
934 // ThreadLocal has RawPtr type.
935 const Type* t = n->as_Phi()->type();
936 if (t->make_ptr() != NULL) {
937 for (uint i = 1; i < n->req(); i++) {
938 Node* in = n->in(i);
939 if (in == NULL)
940 continue; // ignore NULL
941 Node* uncast_in = in->uncast();
942 if (uncast_in->is_top() || uncast_in == n)
943 continue; // ignore top or inputs which go back this node
944 PointsToNode* ptn = ptnode_adr(in->_idx);
945 assert(ptn != NULL, "node should be registered");
946 add_edge(n_ptn, ptn);
947 }
948 break;
949 }
950 ELSE_FAIL("Op_Phi");
951 }
952 case Op_Proj: {
953 // we are only interested in the oop result projection from a call
954 if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
955 n->in(0)->as_Call()->returns_pointer()) {
956 add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(0), NULL);
957 break;
958 }
959 ELSE_FAIL("Op_Proj");
960 }
961 case Op_Rethrow: // Exception object escapes
962 case Op_Return: {
963 if (n->req() > TypeFunc::Parms &&
964 _igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
965 // Treat Return value as LocalVar with GlobalEscape escape state.
966 add_local_var_and_edge(n, PointsToNode::GlobalEscape,
967 n->in(TypeFunc::Parms), NULL);
968 break;
969 }
970 ELSE_FAIL("Op_Return");
971 }
972 case Op_StoreP:
973 case Op_StoreN:
974 case Op_StoreNKlass:
975 case Op_StorePConditional:
976 case Op_CompareAndExchangeP:
977 case Op_CompareAndExchangeN:
978 case Op_CompareAndSwapP:
979 case Op_CompareAndSwapN:
980 case Op_WeakCompareAndSwapP:
981 case Op_WeakCompareAndSwapN:
982 case Op_GetAndSetP:
983 case Op_GetAndSetN: {
984 if (add_final_edges_unsafe_access(n, opcode)) {
985 break;
986 }
987 ELSE_FAIL("Op_StoreP");
988 }
989 case Op_AryEq:
990 case Op_HasNegatives:
991 case Op_StrComp:
992 case Op_StrEquals:
993 case Op_StrIndexOf:
994 case Op_StrIndexOfChar:
995 case Op_StrInflatedCopy:
996 case Op_StrCompressedCopy:
997 case Op_EncodeISOArray: {
998 // char[]/byte[] arrays passed to string intrinsic do not escape but
999 // they are not scalar replaceable. Adjust escape state for them.
1000 // Start from in(2) edge since in(1) is memory edge.
1001 for (uint i = 2; i < n->req(); i++) {
1002 Node* adr = n->in(i);
1003 const Type* at = _igvn->type(adr);
1004 if (!adr->is_top() && at->isa_ptr()) {
1005 assert(at == Type::TOP || at == TypePtr::NULL_PTR ||
1006 at->isa_ptr() != NULL, "expecting a pointer");
1007 if (adr->is_AddP()) {
1008 adr = get_addp_base(adr);
1009 }
1010 PointsToNode* ptn = ptnode_adr(adr->_idx);
1011 assert(ptn != NULL, "node should be registered");
1012 add_edge(n_ptn, ptn);
1013 }
1014 }
1015 break;
1016 }
1017 default: {
1018 // This method should be called only for EA specific nodes which may
1019 // miss some edges when they were created.
1020 #ifdef ASSERT
1021 n->dump(1);
1022 #endif
1023 guarantee(false, "unknown node");
1024 }
1025 }
1026 return;
1027 }
1028
1029 void ConnectionGraph::add_to_congraph_unsafe_access(Node* n, uint opcode, Unique_Node_List* delayed_worklist) {
1030 Node* adr = n->in(MemNode::Address);
1031 const Type* adr_type = _igvn->type(adr);
1032 adr_type = adr_type->make_ptr();
1033 if (adr_type == NULL) {
1034 return; // skip dead nodes
1035 }
1036 if (adr_type->isa_oopptr()
1037 || ((opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass)
1038 && adr_type == TypeRawPtr::NOTNULL
1039 && adr->in(AddPNode::Address)->is_Proj()
1040 && adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
1041 delayed_worklist->push(n); // Process it later.
1042 #ifdef ASSERT
1043 assert (adr->is_AddP(), "expecting an AddP");
1044 if (adr_type == TypeRawPtr::NOTNULL) {
1045 // Verify a raw address for a store captured by Initialize node.
1046 int offs = (int) _igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
1047 assert(offs != Type::OffsetBot, "offset must be a constant");
1048 }
1049 #endif
1050 } else {
1051 // Ignore copy the displaced header to the BoxNode (OSR compilation).
1052 if (adr->is_BoxLock()) {
1053 return;
1054 }
1055 // Stored value escapes in unsafe access.
1056 if ((opcode == Op_StoreP) && adr_type->isa_rawptr()) {
1057 delayed_worklist->push(n); // Process unsafe access later.
1058 return;
1059 }
1060 #ifdef ASSERT
1061 n->dump(1);
1062 assert(false, "not unsafe");
1063 #endif
1064 }
1065 }
1066
1067 bool ConnectionGraph::add_final_edges_unsafe_access(Node* n, uint opcode) {
1068 Node* adr = n->in(MemNode::Address);
1069 const Type *adr_type = _igvn->type(adr);
1070 adr_type = adr_type->make_ptr();
1071 #ifdef ASSERT
1072 if (adr_type == NULL) {
1073 n->dump(1);
1074 assert(adr_type != NULL, "dead node should not be on list");
1075 return true;
1076 }
1077 #endif
1078
1079 if (opcode == Op_GetAndSetP || opcode == Op_GetAndSetN ||
1080 opcode == Op_CompareAndExchangeN || opcode == Op_CompareAndExchangeP) {
1081 add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
1082 }
1083
1084 if (adr_type->isa_oopptr()
1085 || ((opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass)
1086 && adr_type == TypeRawPtr::NOTNULL
1087 && adr->in(AddPNode::Address)->is_Proj()
1088 && adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
1089 // Point Address to Value
1090 PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
1091 assert(adr_ptn != NULL &&
1092 adr_ptn->as_Field()->is_oop(), "node should be registered");
1093 Node* val = n->in(MemNode::ValueIn);
1094 PointsToNode* ptn = ptnode_adr(val->_idx);
1095 assert(ptn != NULL, "node should be registered");
1096 add_edge(adr_ptn, ptn);
1097 return true;
1098 } else if ((opcode == Op_StoreP) && adr_type->isa_rawptr()) {
1099 // Stored value escapes in unsafe access.
1100 Node* val = n->in(MemNode::ValueIn);
1101 PointsToNode* ptn = ptnode_adr(val->_idx);
1102 assert(ptn != NULL, "node should be registered");
1103 set_escape_state(ptn, PointsToNode::GlobalEscape);
1104 // Add edge to object for unsafe access with offset.
1105 PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
1106 assert(adr_ptn != NULL, "node should be registered");
1107 if (adr_ptn->is_Field()) {
1108 assert(adr_ptn->as_Field()->is_oop(), "should be oop field");
1109 add_edge(adr_ptn, ptn);
1110 }
1111 return true;
1112 }
1113 return false;
1114 }
1115
1116 void ConnectionGraph::add_call_node(CallNode* call) {
1117 assert(call->returns_pointer(), "only for call which returns pointer");
1118 uint call_idx = call->_idx;
1119 if (call->is_Allocate()) {
1120 Node* k = call->in(AllocateNode::KlassNode);
1121 const TypeKlassPtr* kt = k->bottom_type()->isa_klassptr();
1122 assert(kt != NULL, "TypeKlassPtr required.");
1123 ciKlass* cik = kt->klass();
1124 PointsToNode::EscapeState es = PointsToNode::NoEscape;
1125 bool scalar_replaceable = true;
1126 if (call->is_AllocateArray()) {
1127 if (!cik->is_array_klass()) { // StressReflectiveCode
1128 es = PointsToNode::GlobalEscape;
1129 } else {
1130 int length = call->in(AllocateNode::ALength)->find_int_con(-1);
1131 if (length < 0 || length > EliminateAllocationArraySizeLimit) {
1132 // Not scalar replaceable if the length is not constant or too big.
1133 scalar_replaceable = false;
1134 }
1135 }
1136 } else { // Allocate instance
1137 if (cik->is_subclass_of(_compile->env()->Thread_klass()) ||
1138 cik->is_subclass_of(_compile->env()->Reference_klass()) ||
1139 !cik->is_instance_klass() || // StressReflectiveCode
1140 !cik->as_instance_klass()->can_be_instantiated() ||
1141 cik->as_instance_klass()->has_finalizer()) {
1142 es = PointsToNode::GlobalEscape;
1143 }
1144 }
1145 add_java_object(call, es);
1146 PointsToNode* ptn = ptnode_adr(call_idx);
1147 if (!scalar_replaceable && ptn->scalar_replaceable()) {
1148 ptn->set_scalar_replaceable(false);
1149 }
1150 } else if (call->is_CallStaticJava()) {
1151 // Call nodes could be different types:
1152 //
1153 // 1. CallDynamicJavaNode (what happened during call is unknown):
1154 //
1155 // - mapped to GlobalEscape JavaObject node if oop is returned;
1156 //
1157 // - all oop arguments are escaping globally;
1158 //
1159 // 2. CallStaticJavaNode (execute bytecode analysis if possible):
1160 //
1161 // - the same as CallDynamicJavaNode if can't do bytecode analysis;
1162 //
1163 // - mapped to GlobalEscape JavaObject node if unknown oop is returned;
1164 // - mapped to NoEscape JavaObject node if non-escaping object allocated
1165 // during call is returned;
1166 // - mapped to ArgEscape LocalVar node pointed to object arguments
1167 // which are returned and does not escape during call;
1168 //
1169 // - oop arguments escaping status is defined by bytecode analysis;
1170 //
1171 // For a static call, we know exactly what method is being called.
1172 // Use bytecode estimator to record whether the call's return value escapes.
1173 ciMethod* meth = call->as_CallJava()->method();
1174 if (meth == NULL) {
1175 const char* name = call->as_CallStaticJava()->_name;
1176 assert(strncmp(name, "_multianewarray", 15) == 0, "TODO: add failed case check");
1177 // Returns a newly allocated unescaped object.
1178 add_java_object(call, PointsToNode::NoEscape);
1179 ptnode_adr(call_idx)->set_scalar_replaceable(false);
1180 } else if (meth->is_boxing_method()) {
1181 // Returns boxing object
1182 PointsToNode::EscapeState es;
1183 vmIntrinsics::ID intr = meth->intrinsic_id();
1184 if (intr == vmIntrinsics::_floatValue || intr == vmIntrinsics::_doubleValue) {
1185 // It does not escape if object is always allocated.
1186 es = PointsToNode::NoEscape;
1187 } else {
1188 // It escapes globally if object could be loaded from cache.
1189 es = PointsToNode::GlobalEscape;
1190 }
1191 add_java_object(call, es);
1192 } else {
1193 BCEscapeAnalyzer* call_analyzer = meth->get_bcea();
1194 call_analyzer->copy_dependencies(_compile->dependencies());
1195 if (call_analyzer->is_return_allocated()) {
1196 // Returns a newly allocated unescaped object, simply
1197 // update dependency information.
1198 // Mark it as NoEscape so that objects referenced by
1199 // it's fields will be marked as NoEscape at least.
1200 add_java_object(call, PointsToNode::NoEscape);
1201 ptnode_adr(call_idx)->set_scalar_replaceable(false);
1202 } else {
1203 // Determine whether any arguments are returned.
1204 const TypeTuple* d = call->tf()->domain();
1205 bool ret_arg = false;
1206 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1207 if (d->field_at(i)->isa_ptr() != NULL &&
1208 call_analyzer->is_arg_returned(i - TypeFunc::Parms)) {
1209 ret_arg = true;
1210 break;
1211 }
1212 }
1213 if (ret_arg) {
1214 add_local_var(call, PointsToNode::ArgEscape);
1215 } else {
1216 // Returns unknown object.
1217 map_ideal_node(call, phantom_obj);
1218 }
1219 }
1220 }
1221 } else {
1222 // An other type of call, assume the worst case:
1223 // returned value is unknown and globally escapes.
1224 assert(call->Opcode() == Op_CallDynamicJava, "add failed case check");
1225 map_ideal_node(call, phantom_obj);
1226 }
1227 }
1228
1229 void ConnectionGraph::process_call_arguments(CallNode *call) {
1230 bool is_arraycopy = false;
1231 switch (call->Opcode()) {
1232 #ifdef ASSERT
1233 case Op_Allocate:
1234 case Op_AllocateArray:
1235 case Op_Lock:
1236 case Op_Unlock:
1237 assert(false, "should be done already");
1238 break;
1239 #endif
1240 case Op_ArrayCopy:
1241 case Op_CallLeafNoFP:
1242 // Most array copies are ArrayCopy nodes at this point but there
1243 // are still a few direct calls to the copy subroutines (See
1244 // PhaseStringOpts::copy_string())
1245 is_arraycopy = (call->Opcode() == Op_ArrayCopy) ||
1246 call->as_CallLeaf()->is_call_to_arraycopystub();
1247 // fall through
1248 case Op_CallLeaf: {
1249 // Stub calls, objects do not escape but they are not scale replaceable.
1250 // Adjust escape state for outgoing arguments.
1251 const TypeTuple * d = call->tf()->domain();
1252 bool src_has_oops = false;
1253 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1254 const Type* at = d->field_at(i);
1255 Node *arg = call->in(i);
1256 if (arg == NULL) {
1257 continue;
1258 }
1259 const Type *aat = _igvn->type(arg);
1260 if (arg->is_top() || !at->isa_ptr() || !aat->isa_ptr())
1261 continue;
1262 if (arg->is_AddP()) {
1263 //
1264 // The inline_native_clone() case when the arraycopy stub is called
1265 // after the allocation before Initialize and CheckCastPP nodes.
1266 // Or normal arraycopy for object arrays case.
1267 //
1268 // Set AddP's base (Allocate) as not scalar replaceable since
1269 // pointer to the base (with offset) is passed as argument.
1270 //
1271 arg = get_addp_base(arg);
1272 }
1273 PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
1274 assert(arg_ptn != NULL, "should be registered");
1275 PointsToNode::EscapeState arg_esc = arg_ptn->escape_state();
1276 if (is_arraycopy || arg_esc < PointsToNode::ArgEscape) {
1277 assert(aat == Type::TOP || aat == TypePtr::NULL_PTR ||
1278 aat->isa_ptr() != NULL, "expecting an Ptr");
1279 bool arg_has_oops = aat->isa_oopptr() &&
1280 (aat->isa_oopptr()->klass() == NULL || aat->isa_instptr() ||
1281 (aat->isa_aryptr() && aat->isa_aryptr()->klass()->is_obj_array_klass()));
1282 if (i == TypeFunc::Parms) {
1283 src_has_oops = arg_has_oops;
1284 }
1285 //
1286 // src or dst could be j.l.Object when other is basic type array:
1287 //
1288 // arraycopy(char[],0,Object*,0,size);
1289 // arraycopy(Object*,0,char[],0,size);
1290 //
1291 // Don't add edges in such cases.
1292 //
1293 bool arg_is_arraycopy_dest = src_has_oops && is_arraycopy &&
1294 arg_has_oops && (i > TypeFunc::Parms);
1295 #ifdef ASSERT
1296 if (!(is_arraycopy ||
1297 BarrierSet::barrier_set()->barrier_set_c2()->is_gc_barrier_node(call) ||
1298 (call->as_CallLeaf()->_name != NULL &&
1299 (strcmp(call->as_CallLeaf()->_name, "updateBytesCRC32") == 0 ||
1300 strcmp(call->as_CallLeaf()->_name, "updateBytesCRC32C") == 0 ||
1301 strcmp(call->as_CallLeaf()->_name, "updateBytesAdler32") == 0 ||
1302 strcmp(call->as_CallLeaf()->_name, "aescrypt_encryptBlock") == 0 ||
1303 strcmp(call->as_CallLeaf()->_name, "aescrypt_decryptBlock") == 0 ||
1304 strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_encryptAESCrypt") == 0 ||
1305 strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_decryptAESCrypt") == 0 ||
1306 strcmp(call->as_CallLeaf()->_name, "electronicCodeBook_encryptAESCrypt") == 0 ||
1307 strcmp(call->as_CallLeaf()->_name, "electronicCodeBook_decryptAESCrypt") == 0 ||
1308 strcmp(call->as_CallLeaf()->_name, "counterMode_AESCrypt") == 0 ||
1309 strcmp(call->as_CallLeaf()->_name, "ghash_processBlocks") == 0 ||
1310 strcmp(call->as_CallLeaf()->_name, "encodeBlock") == 0 ||
1311 strcmp(call->as_CallLeaf()->_name, "sha1_implCompress") == 0 ||
1312 strcmp(call->as_CallLeaf()->_name, "sha1_implCompressMB") == 0 ||
1313 strcmp(call->as_CallLeaf()->_name, "sha256_implCompress") == 0 ||
1314 strcmp(call->as_CallLeaf()->_name, "sha256_implCompressMB") == 0 ||
1315 strcmp(call->as_CallLeaf()->_name, "sha512_implCompress") == 0 ||
1316 strcmp(call->as_CallLeaf()->_name, "sha512_implCompressMB") == 0 ||
1317 strcmp(call->as_CallLeaf()->_name, "multiplyToLen") == 0 ||
1318 strcmp(call->as_CallLeaf()->_name, "squareToLen") == 0 ||
1319 strcmp(call->as_CallLeaf()->_name, "mulAdd") == 0 ||
1320 strcmp(call->as_CallLeaf()->_name, "montgomery_multiply") == 0 ||
1321 strcmp(call->as_CallLeaf()->_name, "montgomery_square") == 0 ||
1322 strcmp(call->as_CallLeaf()->_name, "bigIntegerRightShiftWorker") == 0 ||
1323 strcmp(call->as_CallLeaf()->_name, "bigIntegerLeftShiftWorker") == 0 ||
1324 strcmp(call->as_CallLeaf()->_name, "vectorizedMismatch") == 0)
1325 ))) {
1326 call->dump();
1327 fatal("EA unexpected CallLeaf %s", call->as_CallLeaf()->_name);
1328 }
1329 #endif
1330 // Always process arraycopy's destination object since
1331 // we need to add all possible edges to references in
1332 // source object.
1333 if (arg_esc >= PointsToNode::ArgEscape &&
1334 !arg_is_arraycopy_dest) {
1335 continue;
1336 }
1337 PointsToNode::EscapeState es = PointsToNode::ArgEscape;
1338 if (call->is_ArrayCopy()) {
1339 ArrayCopyNode* ac = call->as_ArrayCopy();
1340 if (ac->is_clonebasic() ||
1341 ac->is_arraycopy_validated() ||
1342 ac->is_copyof_validated() ||
1343 ac->is_copyofrange_validated()) {
1344 es = PointsToNode::NoEscape;
1345 }
1346 }
1347 set_escape_state(arg_ptn, es);
1348 if (arg_is_arraycopy_dest) {
1349 Node* src = call->in(TypeFunc::Parms);
1350 if (src->is_AddP()) {
1351 src = get_addp_base(src);
1352 }
1353 PointsToNode* src_ptn = ptnode_adr(src->_idx);
1354 assert(src_ptn != NULL, "should be registered");
1355 if (arg_ptn != src_ptn) {
1356 // Special arraycopy edge:
1357 // A destination object's field can't have the source object
1358 // as base since objects escape states are not related.
1359 // Only escape state of destination object's fields affects
1360 // escape state of fields in source object.
1361 add_arraycopy(call, es, src_ptn, arg_ptn);
1362 }
1363 }
1364 }
1365 }
1366 break;
1367 }
1368 case Op_CallStaticJava: {
1369 // For a static call, we know exactly what method is being called.
1370 // Use bytecode estimator to record the call's escape affects
1371 #ifdef ASSERT
1372 const char* name = call->as_CallStaticJava()->_name;
1373 assert((name == NULL || strcmp(name, "uncommon_trap") != 0), "normal calls only");
1374 #endif
1375 ciMethod* meth = call->as_CallJava()->method();
1376 if ((meth != NULL) && meth->is_boxing_method()) {
1377 break; // Boxing methods do not modify any oops.
1378 }
1379 BCEscapeAnalyzer* call_analyzer = (meth !=NULL) ? meth->get_bcea() : NULL;
1380 // fall-through if not a Java method or no analyzer information
1381 if (call_analyzer != NULL) {
1382 PointsToNode* call_ptn = ptnode_adr(call->_idx);
1383 const TypeTuple* d = call->tf()->domain();
1384 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1385 const Type* at = d->field_at(i);
1386 int k = i - TypeFunc::Parms;
1387 Node* arg = call->in(i);
1388 PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
1389 if (at->isa_ptr() != NULL &&
1390 call_analyzer->is_arg_returned(k)) {
1391 // The call returns arguments.
1392 if (call_ptn != NULL) { // Is call's result used?
1393 assert(call_ptn->is_LocalVar(), "node should be registered");
1394 assert(arg_ptn != NULL, "node should be registered");
1395 add_edge(call_ptn, arg_ptn);
1396 }
1397 }
1398 if (at->isa_oopptr() != NULL &&
1399 arg_ptn->escape_state() < PointsToNode::GlobalEscape) {
1400 if (!call_analyzer->is_arg_stack(k)) {
1401 // The argument global escapes
1402 set_escape_state(arg_ptn, PointsToNode::GlobalEscape);
1403 } else {
1404 set_escape_state(arg_ptn, PointsToNode::ArgEscape);
1405 if (!call_analyzer->is_arg_local(k)) {
1406 // The argument itself doesn't escape, but any fields might
1407 set_fields_escape_state(arg_ptn, PointsToNode::GlobalEscape);
1408 }
1409 }
1410 }
1411 }
1412 if (call_ptn != NULL && call_ptn->is_LocalVar()) {
1413 // The call returns arguments.
1414 assert(call_ptn->edge_count() > 0, "sanity");
1415 if (!call_analyzer->is_return_local()) {
1416 // Returns also unknown object.
1417 add_edge(call_ptn, phantom_obj);
1418 }
1419 }
1420 break;
1421 }
1422 }
1423 default: {
1424 // Fall-through here if not a Java method or no analyzer information
1425 // or some other type of call, assume the worst case: all arguments
1426 // globally escape.
1427 const TypeTuple* d = call->tf()->domain();
1428 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1429 const Type* at = d->field_at(i);
1430 if (at->isa_oopptr() != NULL) {
1431 Node* arg = call->in(i);
1432 if (arg->is_AddP()) {
1433 arg = get_addp_base(arg);
1434 }
1435 assert(ptnode_adr(arg->_idx) != NULL, "should be defined already");
1436 set_escape_state(ptnode_adr(arg->_idx), PointsToNode::GlobalEscape);
1437 }
1438 }
1439 }
1440 }
1441 }
1442
1443
1444 // Finish Graph construction.
1445 bool ConnectionGraph::complete_connection_graph(
1446 GrowableArray<PointsToNode*>& ptnodes_worklist,
1447 GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1448 GrowableArray<JavaObjectNode*>& java_objects_worklist,
1449 GrowableArray<FieldNode*>& oop_fields_worklist) {
1450 // Normally only 1-3 passes needed to build Connection Graph depending
1451 // on graph complexity. Observed 8 passes in jvm2008 compiler.compiler.
1452 // Set limit to 20 to catch situation when something did go wrong and
1453 // bailout Escape Analysis.
1454 // Also limit build time to 20 sec (60 in debug VM), EscapeAnalysisTimeout flag.
1455 #define CG_BUILD_ITER_LIMIT 20
1456
1457 // Propagate GlobalEscape and ArgEscape escape states and check that
1458 // we still have non-escaping objects. The method pushs on _worklist
1459 // Field nodes which reference phantom_object.
1460 if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1461 return false; // Nothing to do.
1462 }
1463 // Now propagate references to all JavaObject nodes.
1464 int java_objects_length = java_objects_worklist.length();
1465 elapsedTimer time;
1466 bool timeout = false;
1467 int new_edges = 1;
1468 int iterations = 0;
1469 do {
1470 while ((new_edges > 0) &&
1471 (iterations++ < CG_BUILD_ITER_LIMIT)) {
1472 double start_time = time.seconds();
1473 time.start();
1474 new_edges = 0;
1475 // Propagate references to phantom_object for nodes pushed on _worklist
1476 // by find_non_escaped_objects() and find_field_value().
1477 new_edges += add_java_object_edges(phantom_obj, false);
1478 for (int next = 0; next < java_objects_length; ++next) {
1479 JavaObjectNode* ptn = java_objects_worklist.at(next);
1480 new_edges += add_java_object_edges(ptn, true);
1481
1482 #define SAMPLE_SIZE 4
1483 if ((next % SAMPLE_SIZE) == 0) {
1484 // Each 4 iterations calculate how much time it will take
1485 // to complete graph construction.
1486 time.stop();
1487 // Poll for requests from shutdown mechanism to quiesce compiler
1488 // because Connection graph construction may take long time.
1489 CompileBroker::maybe_block();
1490 double stop_time = time.seconds();
1491 double time_per_iter = (stop_time - start_time) / (double)SAMPLE_SIZE;
1492 double time_until_end = time_per_iter * (double)(java_objects_length - next);
1493 if ((start_time + time_until_end) >= EscapeAnalysisTimeout) {
1494 timeout = true;
1495 break; // Timeout
1496 }
1497 start_time = stop_time;
1498 time.start();
1499 }
1500 #undef SAMPLE_SIZE
1501
1502 }
1503 if (timeout) break;
1504 if (new_edges > 0) {
1505 // Update escape states on each iteration if graph was updated.
1506 if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1507 return false; // Nothing to do.
1508 }
1509 }
1510 time.stop();
1511 if (time.seconds() >= EscapeAnalysisTimeout) {
1512 timeout = true;
1513 break;
1514 }
1515 }
1516 if ((iterations < CG_BUILD_ITER_LIMIT) && !timeout) {
1517 time.start();
1518 // Find fields which have unknown value.
1519 int fields_length = oop_fields_worklist.length();
1520 for (int next = 0; next < fields_length; next++) {
1521 FieldNode* field = oop_fields_worklist.at(next);
1522 if (field->edge_count() == 0) {
1523 new_edges += find_field_value(field);
1524 // This code may added new edges to phantom_object.
1525 // Need an other cycle to propagate references to phantom_object.
1526 }
1527 }
1528 time.stop();
1529 if (time.seconds() >= EscapeAnalysisTimeout) {
1530 timeout = true;
1531 break;
1532 }
1533 } else {
1534 new_edges = 0; // Bailout
1535 }
1536 } while (new_edges > 0);
1537
1538 // Bailout if passed limits.
1539 if ((iterations >= CG_BUILD_ITER_LIMIT) || timeout) {
1540 Compile* C = _compile;
1541 if (C->log() != NULL) {
1542 C->log()->begin_elem("connectionGraph_bailout reason='reached ");
1543 C->log()->text("%s", timeout ? "time" : "iterations");
1544 C->log()->end_elem(" limit'");
1545 }
1546 assert(ExitEscapeAnalysisOnTimeout, "infinite EA connection graph build (%f sec, %d iterations) with %d nodes and worklist size %d",
1547 time.seconds(), iterations, nodes_size(), ptnodes_worklist.length());
1548 // Possible infinite build_connection_graph loop,
1549 // bailout (no changes to ideal graph were made).
1550 return false;
1551 }
1552 #ifdef ASSERT
1553 if (Verbose && print_escape_analysis()) {
1554 tty->print_cr("EA: %d iterations to build connection graph with %d nodes and worklist size %d",
1555 iterations, nodes_size(), ptnodes_worklist.length());
1556 }
1557 #endif
1558
1559 #undef CG_BUILD_ITER_LIMIT
1560
1561 // Find fields initialized by NULL for non-escaping Allocations.
1562 int non_escaped_length = non_escaped_worklist.length();
1563 for (int next = 0; next < non_escaped_length; next++) {
1564 JavaObjectNode* ptn = non_escaped_worklist.at(next);
1565 PointsToNode::EscapeState es = ptn->escape_state();
1566 assert(es <= PointsToNode::ArgEscape, "sanity");
1567 if (es == PointsToNode::NoEscape) {
1568 if (find_init_values(ptn, null_obj, _igvn) > 0) {
1569 // Adding references to NULL object does not change escape states
1570 // since it does not escape. Also no fields are added to NULL object.
1571 add_java_object_edges(null_obj, false);
1572 }
1573 }
1574 Node* n = ptn->ideal_node();
1575 if (n->is_Allocate()) {
1576 // The object allocated by this Allocate node will never be
1577 // seen by an other thread. Mark it so that when it is
1578 // expanded no MemBarStoreStore is added.
1579 InitializeNode* ini = n->as_Allocate()->initialization();
1580 if (ini != NULL)
1581 ini->set_does_not_escape();
1582 }
1583 }
1584 return true; // Finished graph construction.
1585 }
1586
1587 // Propagate GlobalEscape and ArgEscape escape states to all nodes
1588 // and check that we still have non-escaping java objects.
1589 bool ConnectionGraph::find_non_escaped_objects(GrowableArray<PointsToNode*>& ptnodes_worklist,
1590 GrowableArray<JavaObjectNode*>& non_escaped_worklist) {
1591 GrowableArray<PointsToNode*> escape_worklist;
1592 // First, put all nodes with GlobalEscape and ArgEscape states on worklist.
1593 int ptnodes_length = ptnodes_worklist.length();
1594 for (int next = 0; next < ptnodes_length; ++next) {
1595 PointsToNode* ptn = ptnodes_worklist.at(next);
1596 if (ptn->escape_state() >= PointsToNode::ArgEscape ||
1597 ptn->fields_escape_state() >= PointsToNode::ArgEscape) {
1598 escape_worklist.push(ptn);
1599 }
1600 }
1601 // Set escape states to referenced nodes (edges list).
1602 while (escape_worklist.length() > 0) {
1603 PointsToNode* ptn = escape_worklist.pop();
1604 PointsToNode::EscapeState es = ptn->escape_state();
1605 PointsToNode::EscapeState field_es = ptn->fields_escape_state();
1606 if (ptn->is_Field() && ptn->as_Field()->is_oop() &&
1607 es >= PointsToNode::ArgEscape) {
1608 // GlobalEscape or ArgEscape state of field means it has unknown value.
1609 if (add_edge(ptn, phantom_obj)) {
1610 // New edge was added
1611 add_field_uses_to_worklist(ptn->as_Field());
1612 }
1613 }
1614 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1615 PointsToNode* e = i.get();
1616 if (e->is_Arraycopy()) {
1617 assert(ptn->arraycopy_dst(), "sanity");
1618 // Propagate only fields escape state through arraycopy edge.
1619 if (e->fields_escape_state() < field_es) {
1620 set_fields_escape_state(e, field_es);
1621 escape_worklist.push(e);
1622 }
1623 } else if (es >= field_es) {
1624 // fields_escape_state is also set to 'es' if it is less than 'es'.
1625 if (e->escape_state() < es) {
1626 set_escape_state(e, es);
1627 escape_worklist.push(e);
1628 }
1629 } else {
1630 // Propagate field escape state.
1631 bool es_changed = false;
1632 if (e->fields_escape_state() < field_es) {
1633 set_fields_escape_state(e, field_es);
1634 es_changed = true;
1635 }
1636 if ((e->escape_state() < field_es) &&
1637 e->is_Field() && ptn->is_JavaObject() &&
1638 e->as_Field()->is_oop()) {
1639 // Change escape state of referenced fields.
1640 set_escape_state(e, field_es);
1641 es_changed = true;
1642 } else if (e->escape_state() < es) {
1643 set_escape_state(e, es);
1644 es_changed = true;
1645 }
1646 if (es_changed) {
1647 escape_worklist.push(e);
1648 }
1649 }
1650 }
1651 }
1652 // Remove escaped objects from non_escaped list.
1653 for (int next = non_escaped_worklist.length()-1; next >= 0 ; --next) {
1654 JavaObjectNode* ptn = non_escaped_worklist.at(next);
1655 if (ptn->escape_state() >= PointsToNode::GlobalEscape) {
1656 non_escaped_worklist.delete_at(next);
1657 }
1658 if (ptn->escape_state() == PointsToNode::NoEscape) {
1659 // Find fields in non-escaped allocations which have unknown value.
1660 find_init_values(ptn, phantom_obj, NULL);
1661 }
1662 }
1663 return (non_escaped_worklist.length() > 0);
1664 }
1665
1666 // Add all references to JavaObject node by walking over all uses.
1667 int ConnectionGraph::add_java_object_edges(JavaObjectNode* jobj, bool populate_worklist) {
1668 int new_edges = 0;
1669 if (populate_worklist) {
1670 // Populate _worklist by uses of jobj's uses.
1671 for (UseIterator i(jobj); i.has_next(); i.next()) {
1672 PointsToNode* use = i.get();
1673 if (use->is_Arraycopy())
1674 continue;
1675 add_uses_to_worklist(use);
1676 if (use->is_Field() && use->as_Field()->is_oop()) {
1677 // Put on worklist all field's uses (loads) and
1678 // related field nodes (same base and offset).
1679 add_field_uses_to_worklist(use->as_Field());
1680 }
1681 }
1682 }
1683 for (int l = 0; l < _worklist.length(); l++) {
1684 PointsToNode* use = _worklist.at(l);
1685 if (PointsToNode::is_base_use(use)) {
1686 // Add reference from jobj to field and from field to jobj (field's base).
1687 use = PointsToNode::get_use_node(use)->as_Field();
1688 if (add_base(use->as_Field(), jobj)) {
1689 new_edges++;
1690 }
1691 continue;
1692 }
1693 assert(!use->is_JavaObject(), "sanity");
1694 if (use->is_Arraycopy()) {
1695 if (jobj == null_obj) // NULL object does not have field edges
1696 continue;
1697 // Added edge from Arraycopy node to arraycopy's source java object
1698 if (add_edge(use, jobj)) {
1699 jobj->set_arraycopy_src();
1700 new_edges++;
1701 }
1702 // and stop here.
1703 continue;
1704 }
1705 if (!add_edge(use, jobj))
1706 continue; // No new edge added, there was such edge already.
1707 new_edges++;
1708 if (use->is_LocalVar()) {
1709 add_uses_to_worklist(use);
1710 if (use->arraycopy_dst()) {
1711 for (EdgeIterator i(use); i.has_next(); i.next()) {
1712 PointsToNode* e = i.get();
1713 if (e->is_Arraycopy()) {
1714 if (jobj == null_obj) // NULL object does not have field edges
1715 continue;
1716 // Add edge from arraycopy's destination java object to Arraycopy node.
1717 if (add_edge(jobj, e)) {
1718 new_edges++;
1719 jobj->set_arraycopy_dst();
1720 }
1721 }
1722 }
1723 }
1724 } else {
1725 // Added new edge to stored in field values.
1726 // Put on worklist all field's uses (loads) and
1727 // related field nodes (same base and offset).
1728 add_field_uses_to_worklist(use->as_Field());
1729 }
1730 }
1731 _worklist.clear();
1732 _in_worklist.reset();
1733 return new_edges;
1734 }
1735
1736 // Put on worklist all related field nodes.
1737 void ConnectionGraph::add_field_uses_to_worklist(FieldNode* field) {
1738 assert(field->is_oop(), "sanity");
1739 int offset = field->offset();
1740 add_uses_to_worklist(field);
1741 // Loop over all bases of this field and push on worklist Field nodes
1742 // with the same offset and base (since they may reference the same field).
1743 for (BaseIterator i(field); i.has_next(); i.next()) {
1744 PointsToNode* base = i.get();
1745 add_fields_to_worklist(field, base);
1746 // Check if the base was source object of arraycopy and go over arraycopy's
1747 // destination objects since values stored to a field of source object are
1748 // accessable by uses (loads) of fields of destination objects.
1749 if (base->arraycopy_src()) {
1750 for (UseIterator j(base); j.has_next(); j.next()) {
1751 PointsToNode* arycp = j.get();
1752 if (arycp->is_Arraycopy()) {
1753 for (UseIterator k(arycp); k.has_next(); k.next()) {
1754 PointsToNode* abase = k.get();
1755 if (abase->arraycopy_dst() && abase != base) {
1756 // Look for the same arraycopy reference.
1757 add_fields_to_worklist(field, abase);
1758 }
1759 }
1760 }
1761 }
1762 }
1763 }
1764 }
1765
1766 // Put on worklist all related field nodes.
1767 void ConnectionGraph::add_fields_to_worklist(FieldNode* field, PointsToNode* base) {
1768 int offset = field->offset();
1769 if (base->is_LocalVar()) {
1770 for (UseIterator j(base); j.has_next(); j.next()) {
1771 PointsToNode* f = j.get();
1772 if (PointsToNode::is_base_use(f)) { // Field
1773 f = PointsToNode::get_use_node(f);
1774 if (f == field || !f->as_Field()->is_oop())
1775 continue;
1776 int offs = f->as_Field()->offset();
1777 if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1778 add_to_worklist(f);
1779 }
1780 }
1781 }
1782 } else {
1783 assert(base->is_JavaObject(), "sanity");
1784 if (// Skip phantom_object since it is only used to indicate that
1785 // this field's content globally escapes.
1786 (base != phantom_obj) &&
1787 // NULL object node does not have fields.
1788 (base != null_obj)) {
1789 for (EdgeIterator i(base); i.has_next(); i.next()) {
1790 PointsToNode* f = i.get();
1791 // Skip arraycopy edge since store to destination object field
1792 // does not update value in source object field.
1793 if (f->is_Arraycopy()) {
1794 assert(base->arraycopy_dst(), "sanity");
1795 continue;
1796 }
1797 if (f == field || !f->as_Field()->is_oop())
1798 continue;
1799 int offs = f->as_Field()->offset();
1800 if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1801 add_to_worklist(f);
1802 }
1803 }
1804 }
1805 }
1806 }
1807
1808 // Find fields which have unknown value.
1809 int ConnectionGraph::find_field_value(FieldNode* field) {
1810 // Escaped fields should have init value already.
1811 assert(field->escape_state() == PointsToNode::NoEscape, "sanity");
1812 int new_edges = 0;
1813 for (BaseIterator i(field); i.has_next(); i.next()) {
1814 PointsToNode* base = i.get();
1815 if (base->is_JavaObject()) {
1816 // Skip Allocate's fields which will be processed later.
1817 if (base->ideal_node()->is_Allocate())
1818 return 0;
1819 assert(base == null_obj, "only NULL ptr base expected here");
1820 }
1821 }
1822 if (add_edge(field, phantom_obj)) {
1823 // New edge was added
1824 new_edges++;
1825 add_field_uses_to_worklist(field);
1826 }
1827 return new_edges;
1828 }
1829
1830 // Find fields initializing values for allocations.
1831 int ConnectionGraph::find_init_values(JavaObjectNode* pta, PointsToNode* init_val, PhaseTransform* phase) {
1832 assert(pta->escape_state() == PointsToNode::NoEscape, "Not escaped Allocate nodes only");
1833 int new_edges = 0;
1834 Node* alloc = pta->ideal_node();
1835 if (init_val == phantom_obj) {
1836 // Do nothing for Allocate nodes since its fields values are
1837 // "known" unless they are initialized by arraycopy/clone.
1838 if (alloc->is_Allocate() && !pta->arraycopy_dst())
1839 return 0;
1840 assert(pta->arraycopy_dst() || alloc->as_CallStaticJava(), "sanity");
1841 #ifdef ASSERT
1842 if (!pta->arraycopy_dst() && alloc->as_CallStaticJava()->method() == NULL) {
1843 const char* name = alloc->as_CallStaticJava()->_name;
1844 assert(strncmp(name, "_multianewarray", 15) == 0, "sanity");
1845 }
1846 #endif
1847 // Non-escaped allocation returned from Java or runtime call have
1848 // unknown values in fields.
1849 for (EdgeIterator i(pta); i.has_next(); i.next()) {
1850 PointsToNode* field = i.get();
1851 if (field->is_Field() && field->as_Field()->is_oop()) {
1852 if (add_edge(field, phantom_obj)) {
1853 // New edge was added
1854 new_edges++;
1855 add_field_uses_to_worklist(field->as_Field());
1856 }
1857 }
1858 }
1859 return new_edges;
1860 }
1861 assert(init_val == null_obj, "sanity");
1862 // Do nothing for Call nodes since its fields values are unknown.
1863 if (!alloc->is_Allocate())
1864 return 0;
1865
1866 InitializeNode* ini = alloc->as_Allocate()->initialization();
1867 bool visited_bottom_offset = false;
1868 GrowableArray<int> offsets_worklist;
1869
1870 // Check if an oop field's initializing value is recorded and add
1871 // a corresponding NULL if field's value if it is not recorded.
1872 // Connection Graph does not record a default initialization by NULL
1873 // captured by Initialize node.
1874 //
1875 for (EdgeIterator i(pta); i.has_next(); i.next()) {
1876 PointsToNode* field = i.get(); // Field (AddP)
1877 if (!field->is_Field() || !field->as_Field()->is_oop())
1878 continue; // Not oop field
1879 int offset = field->as_Field()->offset();
1880 if (offset == Type::OffsetBot) {
1881 if (!visited_bottom_offset) {
1882 // OffsetBot is used to reference array's element,
1883 // always add reference to NULL to all Field nodes since we don't
1884 // known which element is referenced.
1885 if (add_edge(field, null_obj)) {
1886 // New edge was added
1887 new_edges++;
1888 add_field_uses_to_worklist(field->as_Field());
1889 visited_bottom_offset = true;
1890 }
1891 }
1892 } else {
1893 // Check only oop fields.
1894 const Type* adr_type = field->ideal_node()->as_AddP()->bottom_type();
1895 if (adr_type->isa_rawptr()) {
1896 #ifdef ASSERT
1897 // Raw pointers are used for initializing stores so skip it
1898 // since it should be recorded already
1899 Node* base = get_addp_base(field->ideal_node());
1900 assert(adr_type->isa_rawptr() && base->is_Proj() &&
1901 (base->in(0) == alloc),"unexpected pointer type");
1902 #endif
1903 continue;
1904 }
1905 if (!offsets_worklist.contains(offset)) {
1906 offsets_worklist.append(offset);
1907 Node* value = NULL;
1908 if (ini != NULL) {
1909 // StoreP::memory_type() == T_ADDRESS
1910 BasicType ft = UseCompressedOops ? T_NARROWOOP : T_ADDRESS;
1911 Node* store = ini->find_captured_store(offset, type2aelembytes(ft, true), phase);
1912 // Make sure initializing store has the same type as this AddP.
1913 // This AddP may reference non existing field because it is on a
1914 // dead branch of bimorphic call which is not eliminated yet.
1915 if (store != NULL && store->is_Store() &&
1916 store->as_Store()->memory_type() == ft) {
1917 value = store->in(MemNode::ValueIn);
1918 #ifdef ASSERT
1919 if (VerifyConnectionGraph) {
1920 // Verify that AddP already points to all objects the value points to.
1921 PointsToNode* val = ptnode_adr(value->_idx);
1922 assert((val != NULL), "should be processed already");
1923 PointsToNode* missed_obj = NULL;
1924 if (val->is_JavaObject()) {
1925 if (!field->points_to(val->as_JavaObject())) {
1926 missed_obj = val;
1927 }
1928 } else {
1929 if (!val->is_LocalVar() || (val->edge_count() == 0)) {
1930 tty->print_cr("----------init store has invalid value -----");
1931 store->dump();
1932 val->dump();
1933 assert(val->is_LocalVar() && (val->edge_count() > 0), "should be processed already");
1934 }
1935 for (EdgeIterator j(val); j.has_next(); j.next()) {
1936 PointsToNode* obj = j.get();
1937 if (obj->is_JavaObject()) {
1938 if (!field->points_to(obj->as_JavaObject())) {
1939 missed_obj = obj;
1940 break;
1941 }
1942 }
1943 }
1944 }
1945 if (missed_obj != NULL) {
1946 tty->print_cr("----------field---------------------------------");
1947 field->dump();
1948 tty->print_cr("----------missed referernce to object-----------");
1949 missed_obj->dump();
1950 tty->print_cr("----------object referernced by init store -----");
1951 store->dump();
1952 val->dump();
1953 assert(!field->points_to(missed_obj->as_JavaObject()), "missed JavaObject reference");
1954 }
1955 }
1956 #endif
1957 } else {
1958 // There could be initializing stores which follow allocation.
1959 // For example, a volatile field store is not collected
1960 // by Initialize node.
1961 //
1962 // Need to check for dependent loads to separate such stores from
1963 // stores which follow loads. For now, add initial value NULL so
1964 // that compare pointers optimization works correctly.
1965 }
1966 }
1967 if (value == NULL) {
1968 // A field's initializing value was not recorded. Add NULL.
1969 if (add_edge(field, null_obj)) {
1970 // New edge was added
1971 new_edges++;
1972 add_field_uses_to_worklist(field->as_Field());
1973 }
1974 }
1975 }
1976 }
1977 }
1978 return new_edges;
1979 }
1980
1981 // Adjust scalar_replaceable state after Connection Graph is built.
1982 void ConnectionGraph::adjust_scalar_replaceable_state(JavaObjectNode* jobj) {
1983 // Search for non-escaping objects which are not scalar replaceable
1984 // and mark them to propagate the state to referenced objects.
1985
1986 // 1. An object is not scalar replaceable if the field into which it is
1987 // stored has unknown offset (stored into unknown element of an array).
1988 //
1989 for (UseIterator i(jobj); i.has_next(); i.next()) {
1990 PointsToNode* use = i.get();
1991 if (use->is_Arraycopy()) {
1992 continue;
1993 }
1994 if (use->is_Field()) {
1995 FieldNode* field = use->as_Field();
1996 assert(field->is_oop() && field->scalar_replaceable(), "sanity");
1997 if (field->offset() == Type::OffsetBot) {
1998 jobj->set_scalar_replaceable(false);
1999 return;
2000 }
2001 // 2. An object is not scalar replaceable if the field into which it is
2002 // stored has multiple bases one of which is null.
2003 if (field->base_count() > 1) {
2004 for (BaseIterator i(field); i.has_next(); i.next()) {
2005 PointsToNode* base = i.get();
2006 if (base == null_obj) {
2007 jobj->set_scalar_replaceable(false);
2008 return;
2009 }
2010 }
2011 }
2012 }
2013 assert(use->is_Field() || use->is_LocalVar(), "sanity");
2014 // 3. An object is not scalar replaceable if it is merged with other objects.
2015 for (EdgeIterator j(use); j.has_next(); j.next()) {
2016 PointsToNode* ptn = j.get();
2017 if (ptn->is_JavaObject() && ptn != jobj) {
2018 // Mark all objects.
2019 jobj->set_scalar_replaceable(false);
2020 ptn->set_scalar_replaceable(false);
2021 }
2022 }
2023 if (!jobj->scalar_replaceable()) {
2024 return;
2025 }
2026 }
2027
2028 for (EdgeIterator j(jobj); j.has_next(); j.next()) {
2029 if (j.get()->is_Arraycopy()) {
2030 continue;
2031 }
2032
2033 // Non-escaping object node should point only to field nodes.
2034 FieldNode* field = j.get()->as_Field();
2035 int offset = field->as_Field()->offset();
2036
2037 // 4. An object is not scalar replaceable if it has a field with unknown
2038 // offset (array's element is accessed in loop).
2039 if (offset == Type::OffsetBot) {
2040 jobj->set_scalar_replaceable(false);
2041 return;
2042 }
2043 // 5. Currently an object is not scalar replaceable if a LoadStore node
2044 // access its field since the field value is unknown after it.
2045 //
2046 Node* n = field->ideal_node();
2047
2048 // Test for an unsafe access that was parsed as maybe off heap
2049 // (with a CheckCastPP to raw memory).
2050 assert(n->is_AddP(), "expect an address computation");
2051 if (n->in(AddPNode::Base)->is_top() &&
2052 n->in(AddPNode::Address)->Opcode() == Op_CheckCastPP) {
2053 assert(n->in(AddPNode::Address)->bottom_type()->isa_rawptr(), "raw address so raw cast expected");
2054 assert(_igvn->type(n->in(AddPNode::Address)->in(1))->isa_oopptr(), "cast pattern at unsafe access expected");
2055 jobj->set_scalar_replaceable(false);
2056 return;
2057 }
2058
2059 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2060 Node* u = n->fast_out(i);
2061 if (u->is_LoadStore() || (u->is_Mem() && u->as_Mem()->is_mismatched_access())) {
2062 jobj->set_scalar_replaceable(false);
2063 return;
2064 }
2065 }
2066
2067 // 6. Or the address may point to more then one object. This may produce
2068 // the false positive result (set not scalar replaceable)
2069 // since the flow-insensitive escape analysis can't separate
2070 // the case when stores overwrite the field's value from the case
2071 // when stores happened on different control branches.
2072 //
2073 // Note: it will disable scalar replacement in some cases:
2074 //
2075 // Point p[] = new Point[1];
2076 // p[0] = new Point(); // Will be not scalar replaced
2077 //
2078 // but it will save us from incorrect optimizations in next cases:
2079 //
2080 // Point p[] = new Point[1];
2081 // if ( x ) p[0] = new Point(); // Will be not scalar replaced
2082 //
2083 if (field->base_count() > 1) {
2084 for (BaseIterator i(field); i.has_next(); i.next()) {
2085 PointsToNode* base = i.get();
2086 // Don't take into account LocalVar nodes which
2087 // may point to only one object which should be also
2088 // this field's base by now.
2089 if (base->is_JavaObject() && base != jobj) {
2090 // Mark all bases.
2091 jobj->set_scalar_replaceable(false);
2092 base->set_scalar_replaceable(false);
2093 }
2094 }
2095 }
2096 }
2097 }
2098
2099 #ifdef ASSERT
2100 void ConnectionGraph::verify_connection_graph(
2101 GrowableArray<PointsToNode*>& ptnodes_worklist,
2102 GrowableArray<JavaObjectNode*>& non_escaped_worklist,
2103 GrowableArray<JavaObjectNode*>& java_objects_worklist,
2104 GrowableArray<Node*>& addp_worklist) {
2105 // Verify that graph is complete - no new edges could be added.
2106 int java_objects_length = java_objects_worklist.length();
2107 int non_escaped_length = non_escaped_worklist.length();
2108 int new_edges = 0;
2109 for (int next = 0; next < java_objects_length; ++next) {
2110 JavaObjectNode* ptn = java_objects_worklist.at(next);
2111 new_edges += add_java_object_edges(ptn, true);
2112 }
2113 assert(new_edges == 0, "graph was not complete");
2114 // Verify that escape state is final.
2115 int length = non_escaped_worklist.length();
2116 find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist);
2117 assert((non_escaped_length == non_escaped_worklist.length()) &&
2118 (non_escaped_length == length) &&
2119 (_worklist.length() == 0), "escape state was not final");
2120
2121 // Verify fields information.
2122 int addp_length = addp_worklist.length();
2123 for (int next = 0; next < addp_length; ++next ) {
2124 Node* n = addp_worklist.at(next);
2125 FieldNode* field = ptnode_adr(n->_idx)->as_Field();
2126 if (field->is_oop()) {
2127 // Verify that field has all bases
2128 Node* base = get_addp_base(n);
2129 PointsToNode* ptn = ptnode_adr(base->_idx);
2130 if (ptn->is_JavaObject()) {
2131 assert(field->has_base(ptn->as_JavaObject()), "sanity");
2132 } else {
2133 assert(ptn->is_LocalVar(), "sanity");
2134 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2135 PointsToNode* e = i.get();
2136 if (e->is_JavaObject()) {
2137 assert(field->has_base(e->as_JavaObject()), "sanity");
2138 }
2139 }
2140 }
2141 // Verify that all fields have initializing values.
2142 if (field->edge_count() == 0) {
2143 tty->print_cr("----------field does not have references----------");
2144 field->dump();
2145 for (BaseIterator i(field); i.has_next(); i.next()) {
2146 PointsToNode* base = i.get();
2147 tty->print_cr("----------field has next base---------------------");
2148 base->dump();
2149 if (base->is_JavaObject() && (base != phantom_obj) && (base != null_obj)) {
2150 tty->print_cr("----------base has fields-------------------------");
2151 for (EdgeIterator j(base); j.has_next(); j.next()) {
2152 j.get()->dump();
2153 }
2154 tty->print_cr("----------base has references---------------------");
2155 for (UseIterator j(base); j.has_next(); j.next()) {
2156 j.get()->dump();
2157 }
2158 }
2159 }
2160 for (UseIterator i(field); i.has_next(); i.next()) {
2161 i.get()->dump();
2162 }
2163 assert(field->edge_count() > 0, "sanity");
2164 }
2165 }
2166 }
2167 }
2168 #endif
2169
2170 // Optimize ideal graph.
2171 void ConnectionGraph::optimize_ideal_graph(GrowableArray<Node*>& ptr_cmp_worklist,
2172 GrowableArray<Node*>& storestore_worklist) {
2173 Compile* C = _compile;
2174 PhaseIterGVN* igvn = _igvn;
2175 if (EliminateLocks) {
2176 // Mark locks before changing ideal graph.
2177 int cnt = C->macro_count();
2178 for( int i=0; i < cnt; i++ ) {
2179 Node *n = C->macro_node(i);
2180 if (n->is_AbstractLock()) { // Lock and Unlock nodes
2181 AbstractLockNode* alock = n->as_AbstractLock();
2182 if (!alock->is_non_esc_obj()) {
2183 if (not_global_escape(alock->obj_node())) {
2184 assert(!alock->is_eliminated() || alock->is_coarsened(), "sanity");
2185 // The lock could be marked eliminated by lock coarsening
2186 // code during first IGVN before EA. Replace coarsened flag
2187 // to eliminate all associated locks/unlocks.
2188 #ifdef ASSERT
2189 alock->log_lock_optimization(C, "eliminate_lock_set_non_esc3");
2190 #endif
2191 alock->set_non_esc_obj();
2192 }
2193 }
2194 }
2195 }
2196 }
2197
2198 if (OptimizePtrCompare) {
2199 // Add ConI(#CC_GT) and ConI(#CC_EQ).
2200 _pcmp_neq = igvn->makecon(TypeInt::CC_GT);
2201 _pcmp_eq = igvn->makecon(TypeInt::CC_EQ);
2202 // Optimize objects compare.
2203 while (ptr_cmp_worklist.length() != 0) {
2204 Node *n = ptr_cmp_worklist.pop();
2205 Node *res = optimize_ptr_compare(n);
2206 if (res != NULL) {
2207 #ifndef PRODUCT
2208 if (PrintOptimizePtrCompare) {
2209 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"));
2210 if (Verbose) {
2211 n->dump(1);
2212 }
2213 }
2214 #endif
2215 igvn->replace_node(n, res);
2216 }
2217 }
2218 // cleanup
2219 if (_pcmp_neq->outcnt() == 0)
2220 igvn->hash_delete(_pcmp_neq);
2221 if (_pcmp_eq->outcnt() == 0)
2222 igvn->hash_delete(_pcmp_eq);
2223 }
2224
2225 // For MemBarStoreStore nodes added in library_call.cpp, check
2226 // escape status of associated AllocateNode and optimize out
2227 // MemBarStoreStore node if the allocated object never escapes.
2228 while (storestore_worklist.length() != 0) {
2229 Node *n = storestore_worklist.pop();
2230 MemBarStoreStoreNode *storestore = n ->as_MemBarStoreStore();
2231 Node *alloc = storestore->in(MemBarNode::Precedent)->in(0);
2232 assert (alloc->is_Allocate(), "storestore should point to AllocateNode");
2233 if (not_global_escape(alloc)) {
2234 MemBarNode* mb = MemBarNode::make(C, Op_MemBarCPUOrder, Compile::AliasIdxBot);
2235 mb->init_req(TypeFunc::Memory, storestore->in(TypeFunc::Memory));
2236 mb->init_req(TypeFunc::Control, storestore->in(TypeFunc::Control));
2237 igvn->register_new_node_with_optimizer(mb);
2238 igvn->replace_node(storestore, mb);
2239 }
2240 }
2241 }
2242
2243 // Optimize objects compare.
2244 Node* ConnectionGraph::optimize_ptr_compare(Node* n) {
2245 assert(OptimizePtrCompare, "sanity");
2246 PointsToNode* ptn1 = ptnode_adr(n->in(1)->_idx);
2247 PointsToNode* ptn2 = ptnode_adr(n->in(2)->_idx);
2248 JavaObjectNode* jobj1 = unique_java_object(n->in(1));
2249 JavaObjectNode* jobj2 = unique_java_object(n->in(2));
2250 assert(ptn1->is_JavaObject() || ptn1->is_LocalVar(), "sanity");
2251 assert(ptn2->is_JavaObject() || ptn2->is_LocalVar(), "sanity");
2252
2253 // Check simple cases first.
2254 if (jobj1 != NULL) {
2255 if (jobj1->escape_state() == PointsToNode::NoEscape) {
2256 if (jobj1 == jobj2) {
2257 // Comparing the same not escaping object.
2258 return _pcmp_eq;
2259 }
2260 Node* obj = jobj1->ideal_node();
2261 // Comparing not escaping allocation.
2262 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
2263 !ptn2->points_to(jobj1)) {
2264 return _pcmp_neq; // This includes nullness check.
2265 }
2266 }
2267 }
2268 if (jobj2 != NULL) {
2269 if (jobj2->escape_state() == PointsToNode::NoEscape) {
2270 Node* obj = jobj2->ideal_node();
2271 // Comparing not escaping allocation.
2272 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
2273 !ptn1->points_to(jobj2)) {
2274 return _pcmp_neq; // This includes nullness check.
2275 }
2276 }
2277 }
2278 if (jobj1 != NULL && jobj1 != phantom_obj &&
2279 jobj2 != NULL && jobj2 != phantom_obj &&
2280 jobj1->ideal_node()->is_Con() &&
2281 jobj2->ideal_node()->is_Con()) {
2282 // Klass or String constants compare. Need to be careful with
2283 // compressed pointers - compare types of ConN and ConP instead of nodes.
2284 const Type* t1 = jobj1->ideal_node()->get_ptr_type();
2285 const Type* t2 = jobj2->ideal_node()->get_ptr_type();
2286 if (t1->make_ptr() == t2->make_ptr()) {
2287 return _pcmp_eq;
2288 } else {
2289 return _pcmp_neq;
2290 }
2291 }
2292 if (ptn1->meet(ptn2)) {
2293 return NULL; // Sets are not disjoint
2294 }
2295
2296 // Sets are disjoint.
2297 bool set1_has_unknown_ptr = ptn1->points_to(phantom_obj);
2298 bool set2_has_unknown_ptr = ptn2->points_to(phantom_obj);
2299 bool set1_has_null_ptr = ptn1->points_to(null_obj);
2300 bool set2_has_null_ptr = ptn2->points_to(null_obj);
2301 if ((set1_has_unknown_ptr && set2_has_null_ptr) ||
2302 (set2_has_unknown_ptr && set1_has_null_ptr)) {
2303 // Check nullness of unknown object.
2304 return NULL;
2305 }
2306
2307 // Disjointness by itself is not sufficient since
2308 // alias analysis is not complete for escaped objects.
2309 // Disjoint sets are definitely unrelated only when
2310 // at least one set has only not escaping allocations.
2311 if (!set1_has_unknown_ptr && !set1_has_null_ptr) {
2312 if (ptn1->non_escaping_allocation()) {
2313 return _pcmp_neq;
2314 }
2315 }
2316 if (!set2_has_unknown_ptr && !set2_has_null_ptr) {
2317 if (ptn2->non_escaping_allocation()) {
2318 return _pcmp_neq;
2319 }
2320 }
2321 return NULL;
2322 }
2323
2324 // Connection Graph constuction functions.
2325
2326 void ConnectionGraph::add_local_var(Node *n, PointsToNode::EscapeState es) {
2327 PointsToNode* ptadr = _nodes.at(n->_idx);
2328 if (ptadr != NULL) {
2329 assert(ptadr->is_LocalVar() && ptadr->ideal_node() == n, "sanity");
2330 return;
2331 }
2332 Compile* C = _compile;
2333 ptadr = new (C->comp_arena()) LocalVarNode(this, n, es);
2334 _nodes.at_put(n->_idx, ptadr);
2335 }
2336
2337 void ConnectionGraph::add_java_object(Node *n, PointsToNode::EscapeState es) {
2338 PointsToNode* ptadr = _nodes.at(n->_idx);
2339 if (ptadr != NULL) {
2340 assert(ptadr->is_JavaObject() && ptadr->ideal_node() == n, "sanity");
2341 return;
2342 }
2343 Compile* C = _compile;
2344 ptadr = new (C->comp_arena()) JavaObjectNode(this, n, es);
2345 _nodes.at_put(n->_idx, ptadr);
2346 }
2347
2348 void ConnectionGraph::add_field(Node *n, PointsToNode::EscapeState es, int offset) {
2349 PointsToNode* ptadr = _nodes.at(n->_idx);
2350 if (ptadr != NULL) {
2351 assert(ptadr->is_Field() && ptadr->ideal_node() == n, "sanity");
2352 return;
2353 }
2354 bool unsafe = false;
2355 bool is_oop = is_oop_field(n, offset, &unsafe);
2356 if (unsafe) {
2357 es = PointsToNode::GlobalEscape;
2358 }
2359 Compile* C = _compile;
2360 FieldNode* field = new (C->comp_arena()) FieldNode(this, n, es, offset, is_oop);
2361 _nodes.at_put(n->_idx, field);
2362 }
2363
2364 void ConnectionGraph::add_arraycopy(Node *n, PointsToNode::EscapeState es,
2365 PointsToNode* src, PointsToNode* dst) {
2366 assert(!src->is_Field() && !dst->is_Field(), "only for JavaObject and LocalVar");
2367 assert((src != null_obj) && (dst != null_obj), "not for ConP NULL");
2368 PointsToNode* ptadr = _nodes.at(n->_idx);
2369 if (ptadr != NULL) {
2370 assert(ptadr->is_Arraycopy() && ptadr->ideal_node() == n, "sanity");
2371 return;
2372 }
2373 Compile* C = _compile;
2374 ptadr = new (C->comp_arena()) ArraycopyNode(this, n, es);
2375 _nodes.at_put(n->_idx, ptadr);
2376 // Add edge from arraycopy node to source object.
2377 (void)add_edge(ptadr, src);
2378 src->set_arraycopy_src();
2379 // Add edge from destination object to arraycopy node.
2380 (void)add_edge(dst, ptadr);
2381 dst->set_arraycopy_dst();
2382 }
2383
2384 bool ConnectionGraph::is_oop_field(Node* n, int offset, bool* unsafe) {
2385 const Type* adr_type = n->as_AddP()->bottom_type();
2386 BasicType bt = T_INT;
2387 if (offset == Type::OffsetBot) {
2388 // Check only oop fields.
2389 if (!adr_type->isa_aryptr() ||
2390 (adr_type->isa_aryptr()->klass() == NULL) ||
2391 adr_type->isa_aryptr()->klass()->is_obj_array_klass()) {
2392 // OffsetBot is used to reference array's element. Ignore first AddP.
2393 if (find_second_addp(n, n->in(AddPNode::Base)) == NULL) {
2394 bt = T_OBJECT;
2395 }
2396 }
2397 } else if (offset != oopDesc::klass_offset_in_bytes()) {
2398 if (adr_type->isa_instptr()) {
2399 ciField* field = _compile->alias_type(adr_type->isa_instptr())->field();
2400 if (field != NULL) {
2401 bt = field->layout_type();
2402 } else {
2403 // Check for unsafe oop field access
2404 if (n->has_out_with(Op_StoreP, Op_LoadP, Op_StoreN, Op_LoadN) ||
2405 n->has_out_with(Op_GetAndSetP, Op_GetAndSetN, Op_CompareAndExchangeP, Op_CompareAndExchangeN) ||
2406 n->has_out_with(Op_CompareAndSwapP, Op_CompareAndSwapN, Op_WeakCompareAndSwapP, Op_WeakCompareAndSwapN) ||
2407 BarrierSet::barrier_set()->barrier_set_c2()->escape_has_out_with_unsafe_object(n)) {
2408 bt = T_OBJECT;
2409 (*unsafe) = true;
2410 }
2411 }
2412 } else if (adr_type->isa_aryptr()) {
2413 if (offset == arrayOopDesc::length_offset_in_bytes()) {
2414 // Ignore array length load.
2415 } else if (find_second_addp(n, n->in(AddPNode::Base)) != NULL) {
2416 // Ignore first AddP.
2417 } else {
2418 const Type* elemtype = adr_type->isa_aryptr()->elem();
2419 bt = elemtype->array_element_basic_type();
2420 }
2421 } else if (adr_type->isa_rawptr() || adr_type->isa_klassptr()) {
2422 // Allocation initialization, ThreadLocal field access, unsafe access
2423 if (n->has_out_with(Op_StoreP, Op_LoadP, Op_StoreN, Op_LoadN) ||
2424 n->has_out_with(Op_GetAndSetP, Op_GetAndSetN, Op_CompareAndExchangeP, Op_CompareAndExchangeN) ||
2425 n->has_out_with(Op_CompareAndSwapP, Op_CompareAndSwapN, Op_WeakCompareAndSwapP, Op_WeakCompareAndSwapN) ||
2426 BarrierSet::barrier_set()->barrier_set_c2()->escape_has_out_with_unsafe_object(n)) {
2427 bt = T_OBJECT;
2428 }
2429 }
2430 }
2431 // Note: T_NARROWOOP is not classed as a real reference type
2432 return (is_reference_type(bt) || bt == T_NARROWOOP);
2433 }
2434
2435 // Returns unique pointed java object or NULL.
2436 JavaObjectNode* ConnectionGraph::unique_java_object(Node *n) {
2437 assert(!_collecting, "should not call when contructed graph");
2438 // If the node was created after the escape computation we can't answer.
2439 uint idx = n->_idx;
2440 if (idx >= nodes_size()) {
2441 return NULL;
2442 }
2443 PointsToNode* ptn = ptnode_adr(idx);
2444 if (ptn == NULL) {
2445 return NULL;
2446 }
2447 if (ptn->is_JavaObject()) {
2448 return ptn->as_JavaObject();
2449 }
2450 assert(ptn->is_LocalVar(), "sanity");
2451 // Check all java objects it points to.
2452 JavaObjectNode* jobj = NULL;
2453 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2454 PointsToNode* e = i.get();
2455 if (e->is_JavaObject()) {
2456 if (jobj == NULL) {
2457 jobj = e->as_JavaObject();
2458 } else if (jobj != e) {
2459 return NULL;
2460 }
2461 }
2462 }
2463 return jobj;
2464 }
2465
2466 // Return true if this node points only to non-escaping allocations.
2467 bool PointsToNode::non_escaping_allocation() {
2468 if (is_JavaObject()) {
2469 Node* n = ideal_node();
2470 if (n->is_Allocate() || n->is_CallStaticJava()) {
2471 return (escape_state() == PointsToNode::NoEscape);
2472 } else {
2473 return false;
2474 }
2475 }
2476 assert(is_LocalVar(), "sanity");
2477 // Check all java objects it points to.
2478 for (EdgeIterator i(this); i.has_next(); i.next()) {
2479 PointsToNode* e = i.get();
2480 if (e->is_JavaObject()) {
2481 Node* n = e->ideal_node();
2482 if ((e->escape_state() != PointsToNode::NoEscape) ||
2483 !(n->is_Allocate() || n->is_CallStaticJava())) {
2484 return false;
2485 }
2486 }
2487 }
2488 return true;
2489 }
2490
2491 // Return true if we know the node does not escape globally.
2492 bool ConnectionGraph::not_global_escape(Node *n) {
2493 assert(!_collecting, "should not call during graph construction");
2494 // If the node was created after the escape computation we can't answer.
2495 uint idx = n->_idx;
2496 if (idx >= nodes_size()) {
2497 return false;
2498 }
2499 PointsToNode* ptn = ptnode_adr(idx);
2500 if (ptn == NULL) {
2501 return false; // not in congraph (e.g. ConI)
2502 }
2503 PointsToNode::EscapeState es = ptn->escape_state();
2504 // If we have already computed a value, return it.
2505 if (es >= PointsToNode::GlobalEscape)
2506 return false;
2507 if (ptn->is_JavaObject()) {
2508 return true; // (es < PointsToNode::GlobalEscape);
2509 }
2510 assert(ptn->is_LocalVar(), "sanity");
2511 // Check all java objects it points to.
2512 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2513 if (i.get()->escape_state() >= PointsToNode::GlobalEscape)
2514 return false;
2515 }
2516 return true;
2517 }
2518
2519
2520 // Helper functions
2521
2522 // Return true if this node points to specified node or nodes it points to.
2523 bool PointsToNode::points_to(JavaObjectNode* ptn) const {
2524 if (is_JavaObject()) {
2525 return (this == ptn);
2526 }
2527 assert(is_LocalVar() || is_Field(), "sanity");
2528 for (EdgeIterator i(this); i.has_next(); i.next()) {
2529 if (i.get() == ptn)
2530 return true;
2531 }
2532 return false;
2533 }
2534
2535 // Return true if one node points to an other.
2536 bool PointsToNode::meet(PointsToNode* ptn) {
2537 if (this == ptn) {
2538 return true;
2539 } else if (ptn->is_JavaObject()) {
2540 return this->points_to(ptn->as_JavaObject());
2541 } else if (this->is_JavaObject()) {
2542 return ptn->points_to(this->as_JavaObject());
2543 }
2544 assert(this->is_LocalVar() && ptn->is_LocalVar(), "sanity");
2545 int ptn_count = ptn->edge_count();
2546 for (EdgeIterator i(this); i.has_next(); i.next()) {
2547 PointsToNode* this_e = i.get();
2548 for (int j = 0; j < ptn_count; j++) {
2549 if (this_e == ptn->edge(j))
2550 return true;
2551 }
2552 }
2553 return false;
2554 }
2555
2556 #ifdef ASSERT
2557 // Return true if bases point to this java object.
2558 bool FieldNode::has_base(JavaObjectNode* jobj) const {
2559 for (BaseIterator i(this); i.has_next(); i.next()) {
2560 if (i.get() == jobj)
2561 return true;
2562 }
2563 return false;
2564 }
2565 #endif
2566
2567 int ConnectionGraph::address_offset(Node* adr, PhaseTransform *phase) {
2568 const Type *adr_type = phase->type(adr);
2569 if (adr->is_AddP() && adr_type->isa_oopptr() == NULL &&
2570 adr->in(AddPNode::Address)->is_Proj() &&
2571 adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
2572 // We are computing a raw address for a store captured by an Initialize
2573 // compute an appropriate address type. AddP cases #3 and #5 (see below).
2574 int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
2575 assert(offs != Type::OffsetBot ||
2576 adr->in(AddPNode::Address)->in(0)->is_AllocateArray(),
2577 "offset must be a constant or it is initialization of array");
2578 return offs;
2579 }
2580 const TypePtr *t_ptr = adr_type->isa_ptr();
2581 assert(t_ptr != NULL, "must be a pointer type");
2582 return t_ptr->offset();
2583 }
2584
2585 Node* ConnectionGraph::get_addp_base(Node *addp) {
2586 assert(addp->is_AddP(), "must be AddP");
2587 //
2588 // AddP cases for Base and Address inputs:
2589 // case #1. Direct object's field reference:
2590 // Allocate
2591 // |
2592 // Proj #5 ( oop result )
2593 // |
2594 // CheckCastPP (cast to instance type)
2595 // | |
2596 // AddP ( base == address )
2597 //
2598 // case #2. Indirect object's field reference:
2599 // Phi
2600 // |
2601 // CastPP (cast to instance type)
2602 // | |
2603 // AddP ( base == address )
2604 //
2605 // case #3. Raw object's field reference for Initialize node:
2606 // Allocate
2607 // |
2608 // Proj #5 ( oop result )
2609 // top |
2610 // \ |
2611 // AddP ( base == top )
2612 //
2613 // case #4. Array's element reference:
2614 // {CheckCastPP | CastPP}
2615 // | | |
2616 // | AddP ( array's element offset )
2617 // | |
2618 // AddP ( array's offset )
2619 //
2620 // case #5. Raw object's field reference for arraycopy stub call:
2621 // The inline_native_clone() case when the arraycopy stub is called
2622 // after the allocation before Initialize and CheckCastPP nodes.
2623 // Allocate
2624 // |
2625 // Proj #5 ( oop result )
2626 // | |
2627 // AddP ( base == address )
2628 //
2629 // case #6. Constant Pool, ThreadLocal, CastX2P or
2630 // Raw object's field reference:
2631 // {ConP, ThreadLocal, CastX2P, raw Load}
2632 // top |
2633 // \ |
2634 // AddP ( base == top )
2635 //
2636 // case #7. Klass's field reference.
2637 // LoadKlass
2638 // | |
2639 // AddP ( base == address )
2640 //
2641 // case #8. narrow Klass's field reference.
2642 // LoadNKlass
2643 // |
2644 // DecodeN
2645 // | |
2646 // AddP ( base == address )
2647 //
2648 // case #9. Mixed unsafe access
2649 // {instance}
2650 // |
2651 // CheckCastPP (raw)
2652 // top |
2653 // \ |
2654 // AddP ( base == top )
2655 //
2656 Node *base = addp->in(AddPNode::Base);
2657 if (base->uncast()->is_top()) { // The AddP case #3 and #6 and #9.
2658 base = addp->in(AddPNode::Address);
2659 while (base->is_AddP()) {
2660 // Case #6 (unsafe access) may have several chained AddP nodes.
2661 assert(base->in(AddPNode::Base)->uncast()->is_top(), "expected unsafe access address only");
2662 base = base->in(AddPNode::Address);
2663 }
2664 if (base->Opcode() == Op_CheckCastPP &&
2665 base->bottom_type()->isa_rawptr() &&
2666 _igvn->type(base->in(1))->isa_oopptr()) {
2667 base = base->in(1); // Case #9
2668 } else {
2669 Node* uncast_base = base->uncast();
2670 int opcode = uncast_base->Opcode();
2671 assert(opcode == Op_ConP || opcode == Op_ThreadLocal ||
2672 opcode == Op_CastX2P || uncast_base->is_DecodeNarrowPtr() ||
2673 (uncast_base->is_Mem() && (uncast_base->bottom_type()->isa_rawptr() != NULL)) ||
2674 (uncast_base->is_Proj() && uncast_base->in(0)->is_Allocate()), "sanity");
2675 }
2676 }
2677 return base;
2678 }
2679
2680 Node* ConnectionGraph::find_second_addp(Node* addp, Node* n) {
2681 assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
2682 Node* addp2 = addp->raw_out(0);
2683 if (addp->outcnt() == 1 && addp2->is_AddP() &&
2684 addp2->in(AddPNode::Base) == n &&
2685 addp2->in(AddPNode::Address) == addp) {
2686 assert(addp->in(AddPNode::Base) == n, "expecting the same base");
2687 //
2688 // Find array's offset to push it on worklist first and
2689 // as result process an array's element offset first (pushed second)
2690 // to avoid CastPP for the array's offset.
2691 // Otherwise the inserted CastPP (LocalVar) will point to what
2692 // the AddP (Field) points to. Which would be wrong since
2693 // the algorithm expects the CastPP has the same point as
2694 // as AddP's base CheckCastPP (LocalVar).
2695 //
2696 // ArrayAllocation
2697 // |
2698 // CheckCastPP
2699 // |
2700 // memProj (from ArrayAllocation CheckCastPP)
2701 // | ||
2702 // | || Int (element index)
2703 // | || | ConI (log(element size))
2704 // | || | /
2705 // | || LShift
2706 // | || /
2707 // | AddP (array's element offset)
2708 // | |
2709 // | | ConI (array's offset: #12(32-bits) or #24(64-bits))
2710 // | / /
2711 // AddP (array's offset)
2712 // |
2713 // Load/Store (memory operation on array's element)
2714 //
2715 return addp2;
2716 }
2717 return NULL;
2718 }
2719
2720 //
2721 // Adjust the type and inputs of an AddP which computes the
2722 // address of a field of an instance
2723 //
2724 bool ConnectionGraph::split_AddP(Node *addp, Node *base) {
2725 PhaseGVN* igvn = _igvn;
2726 const TypeOopPtr *base_t = igvn->type(base)->isa_oopptr();
2727 assert(base_t != NULL && base_t->is_known_instance(), "expecting instance oopptr");
2728 const TypeOopPtr *t = igvn->type(addp)->isa_oopptr();
2729 if (t == NULL) {
2730 // We are computing a raw address for a store captured by an Initialize
2731 // compute an appropriate address type (cases #3 and #5).
2732 assert(igvn->type(addp) == TypeRawPtr::NOTNULL, "must be raw pointer");
2733 assert(addp->in(AddPNode::Address)->is_Proj(), "base of raw address must be result projection from allocation");
2734 intptr_t offs = (int)igvn->find_intptr_t_con(addp->in(AddPNode::Offset), Type::OffsetBot);
2735 assert(offs != Type::OffsetBot, "offset must be a constant");
2736 t = base_t->add_offset(offs)->is_oopptr();
2737 }
2738 int inst_id = base_t->instance_id();
2739 assert(!t->is_known_instance() || t->instance_id() == inst_id,
2740 "old type must be non-instance or match new type");
2741
2742 // The type 't' could be subclass of 'base_t'.
2743 // As result t->offset() could be large then base_t's size and it will
2744 // cause the failure in add_offset() with narrow oops since TypeOopPtr()
2745 // constructor verifies correctness of the offset.
2746 //
2747 // It could happened on subclass's branch (from the type profiling
2748 // inlining) which was not eliminated during parsing since the exactness
2749 // of the allocation type was not propagated to the subclass type check.
2750 //
2751 // Or the type 't' could be not related to 'base_t' at all.
2752 // It could happened when CHA type is different from MDO type on a dead path
2753 // (for example, from instanceof check) which is not collapsed during parsing.
2754 //
2755 // Do nothing for such AddP node and don't process its users since
2756 // this code branch will go away.
2757 //
2758 if (!t->is_known_instance() &&
2759 !base_t->klass()->is_subtype_of(t->klass())) {
2760 return false; // bail out
2761 }
2762 const TypeOopPtr *tinst = base_t->add_offset(t->offset())->is_oopptr();
2763 // Do NOT remove the next line: ensure a new alias index is allocated
2764 // for the instance type. Note: C++ will not remove it since the call
2765 // has side effect.
2766 int alias_idx = _compile->get_alias_index(tinst);
2767 igvn->set_type(addp, tinst);
2768 // record the allocation in the node map
2769 set_map(addp, get_map(base->_idx));
2770 // Set addp's Base and Address to 'base'.
2771 Node *abase = addp->in(AddPNode::Base);
2772 Node *adr = addp->in(AddPNode::Address);
2773 if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
2774 adr->in(0)->_idx == (uint)inst_id) {
2775 // Skip AddP cases #3 and #5.
2776 } else {
2777 assert(!abase->is_top(), "sanity"); // AddP case #3
2778 if (abase != base) {
2779 igvn->hash_delete(addp);
2780 addp->set_req(AddPNode::Base, base);
2781 if (abase == adr) {
2782 addp->set_req(AddPNode::Address, base);
2783 } else {
2784 // AddP case #4 (adr is array's element offset AddP node)
2785 #ifdef ASSERT
2786 const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
2787 assert(adr->is_AddP() && atype != NULL &&
2788 atype->instance_id() == inst_id, "array's element offset should be processed first");
2789 #endif
2790 }
2791 igvn->hash_insert(addp);
2792 }
2793 }
2794 // Put on IGVN worklist since at least addp's type was changed above.
2795 record_for_optimizer(addp);
2796 return true;
2797 }
2798
2799 //
2800 // Create a new version of orig_phi if necessary. Returns either the newly
2801 // created phi or an existing phi. Sets create_new to indicate whether a new
2802 // phi was created. Cache the last newly created phi in the node map.
2803 //
2804 PhiNode *ConnectionGraph::create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist, bool &new_created) {
2805 Compile *C = _compile;
2806 PhaseGVN* igvn = _igvn;
2807 new_created = false;
2808 int phi_alias_idx = C->get_alias_index(orig_phi->adr_type());
2809 // nothing to do if orig_phi is bottom memory or matches alias_idx
2810 if (phi_alias_idx == alias_idx) {
2811 return orig_phi;
2812 }
2813 // Have we recently created a Phi for this alias index?
2814 PhiNode *result = get_map_phi(orig_phi->_idx);
2815 if (result != NULL && C->get_alias_index(result->adr_type()) == alias_idx) {
2816 return result;
2817 }
2818 // Previous check may fail when the same wide memory Phi was split into Phis
2819 // for different memory slices. Search all Phis for this region.
2820 if (result != NULL) {
2821 Node* region = orig_phi->in(0);
2822 for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
2823 Node* phi = region->fast_out(i);
2824 if (phi->is_Phi() &&
2825 C->get_alias_index(phi->as_Phi()->adr_type()) == alias_idx) {
2826 assert(phi->_idx >= nodes_size(), "only new Phi per instance memory slice");
2827 return phi->as_Phi();
2828 }
2829 }
2830 }
2831 if (C->live_nodes() + 2*NodeLimitFudgeFactor > C->max_node_limit()) {
2832 if (C->do_escape_analysis() == true && !C->failing()) {
2833 // Retry compilation without escape analysis.
2834 // If this is the first failure, the sentinel string will "stick"
2835 // to the Compile object, and the C2Compiler will see it and retry.
2836 C->record_failure(C2Compiler::retry_no_escape_analysis());
2837 }
2838 return NULL;
2839 }
2840 orig_phi_worklist.append_if_missing(orig_phi);
2841 const TypePtr *atype = C->get_adr_type(alias_idx);
2842 result = PhiNode::make(orig_phi->in(0), NULL, Type::MEMORY, atype);
2843 C->copy_node_notes_to(result, orig_phi);
2844 igvn->set_type(result, result->bottom_type());
2845 record_for_optimizer(result);
2846 set_map(orig_phi, result);
2847 new_created = true;
2848 return result;
2849 }
2850
2851 //
2852 // Return a new version of Memory Phi "orig_phi" with the inputs having the
2853 // specified alias index.
2854 //
2855 PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist) {
2856 assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
2857 Compile *C = _compile;
2858 PhaseGVN* igvn = _igvn;
2859 bool new_phi_created;
2860 PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, new_phi_created);
2861 if (!new_phi_created) {
2862 return result;
2863 }
2864 GrowableArray<PhiNode *> phi_list;
2865 GrowableArray<uint> cur_input;
2866 PhiNode *phi = orig_phi;
2867 uint idx = 1;
2868 bool finished = false;
2869 while(!finished) {
2870 while (idx < phi->req()) {
2871 Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist);
2872 if (mem != NULL && mem->is_Phi()) {
2873 PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, new_phi_created);
2874 if (new_phi_created) {
2875 // found an phi for which we created a new split, push current one on worklist and begin
2876 // processing new one
2877 phi_list.push(phi);
2878 cur_input.push(idx);
2879 phi = mem->as_Phi();
2880 result = newphi;
2881 idx = 1;
2882 continue;
2883 } else {
2884 mem = newphi;
2885 }
2886 }
2887 if (C->failing()) {
2888 return NULL;
2889 }
2890 result->set_req(idx++, mem);
2891 }
2892 #ifdef ASSERT
2893 // verify that the new Phi has an input for each input of the original
2894 assert( phi->req() == result->req(), "must have same number of inputs.");
2895 assert( result->in(0) != NULL && result->in(0) == phi->in(0), "regions must match");
2896 #endif
2897 // Check if all new phi's inputs have specified alias index.
2898 // Otherwise use old phi.
2899 for (uint i = 1; i < phi->req(); i++) {
2900 Node* in = result->in(i);
2901 assert((phi->in(i) == NULL) == (in == NULL), "inputs must correspond.");
2902 }
2903 // we have finished processing a Phi, see if there are any more to do
2904 finished = (phi_list.length() == 0 );
2905 if (!finished) {
2906 phi = phi_list.pop();
2907 idx = cur_input.pop();
2908 PhiNode *prev_result = get_map_phi(phi->_idx);
2909 prev_result->set_req(idx++, result);
2910 result = prev_result;
2911 }
2912 }
2913 return result;
2914 }
2915
2916 //
2917 // The next methods are derived from methods in MemNode.
2918 //
2919 Node* ConnectionGraph::step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *toop) {
2920 Node *mem = mmem;
2921 // TypeOopPtr::NOTNULL+any is an OOP with unknown offset - generally
2922 // means an array I have not precisely typed yet. Do not do any
2923 // alias stuff with it any time soon.
2924 if (toop->base() != Type::AnyPtr &&
2925 !(toop->klass() != NULL &&
2926 toop->klass()->is_java_lang_Object() &&
2927 toop->offset() == Type::OffsetBot)) {
2928 mem = mmem->memory_at(alias_idx);
2929 // Update input if it is progress over what we have now
2930 }
2931 return mem;
2932 }
2933
2934 //
2935 // Move memory users to their memory slices.
2936 //
2937 void ConnectionGraph::move_inst_mem(Node* n, GrowableArray<PhiNode *> &orig_phis) {
2938 Compile* C = _compile;
2939 PhaseGVN* igvn = _igvn;
2940 const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr();
2941 assert(tp != NULL, "ptr type");
2942 int alias_idx = C->get_alias_index(tp);
2943 int general_idx = C->get_general_index(alias_idx);
2944
2945 // Move users first
2946 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2947 Node* use = n->fast_out(i);
2948 if (use->is_MergeMem()) {
2949 MergeMemNode* mmem = use->as_MergeMem();
2950 assert(n == mmem->memory_at(alias_idx), "should be on instance memory slice");
2951 if (n != mmem->memory_at(general_idx) || alias_idx == general_idx) {
2952 continue; // Nothing to do
2953 }
2954 // Replace previous general reference to mem node.
2955 uint orig_uniq = C->unique();
2956 Node* m = find_inst_mem(n, general_idx, orig_phis);
2957 assert(orig_uniq == C->unique(), "no new nodes");
2958 mmem->set_memory_at(general_idx, m);
2959 --imax;
2960 --i;
2961 } else if (use->is_MemBar()) {
2962 assert(!use->is_Initialize(), "initializing stores should not be moved");
2963 if (use->req() > MemBarNode::Precedent &&
2964 use->in(MemBarNode::Precedent) == n) {
2965 // Don't move related membars.
2966 record_for_optimizer(use);
2967 continue;
2968 }
2969 tp = use->as_MemBar()->adr_type()->isa_ptr();
2970 if ((tp != NULL && C->get_alias_index(tp) == alias_idx) ||
2971 alias_idx == general_idx) {
2972 continue; // Nothing to do
2973 }
2974 // Move to general memory slice.
2975 uint orig_uniq = C->unique();
2976 Node* m = find_inst_mem(n, general_idx, orig_phis);
2977 assert(orig_uniq == C->unique(), "no new nodes");
2978 igvn->hash_delete(use);
2979 imax -= use->replace_edge(n, m);
2980 igvn->hash_insert(use);
2981 record_for_optimizer(use);
2982 --i;
2983 #ifdef ASSERT
2984 } else if (use->is_Mem()) {
2985 if (use->Opcode() == Op_StoreCM && use->in(MemNode::OopStore) == n) {
2986 // Don't move related cardmark.
2987 continue;
2988 }
2989 // Memory nodes should have new memory input.
2990 tp = igvn->type(use->in(MemNode::Address))->isa_ptr();
2991 assert(tp != NULL, "ptr type");
2992 int idx = C->get_alias_index(tp);
2993 assert(get_map(use->_idx) != NULL || idx == alias_idx,
2994 "Following memory nodes should have new memory input or be on the same memory slice");
2995 } else if (use->is_Phi()) {
2996 // Phi nodes should be split and moved already.
2997 tp = use->as_Phi()->adr_type()->isa_ptr();
2998 assert(tp != NULL, "ptr type");
2999 int idx = C->get_alias_index(tp);
3000 assert(idx == alias_idx, "Following Phi nodes should be on the same memory slice");
3001 } else {
3002 use->dump();
3003 assert(false, "should not be here");
3004 #endif
3005 }
3006 }
3007 }
3008
3009 //
3010 // Search memory chain of "mem" to find a MemNode whose address
3011 // is the specified alias index.
3012 //
3013 Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArray<PhiNode *> &orig_phis) {
3014 if (orig_mem == NULL)
3015 return orig_mem;
3016 Compile* C = _compile;
3017 PhaseGVN* igvn = _igvn;
3018 const TypeOopPtr *toop = C->get_adr_type(alias_idx)->isa_oopptr();
3019 bool is_instance = (toop != NULL) && toop->is_known_instance();
3020 Node *start_mem = C->start()->proj_out_or_null(TypeFunc::Memory);
3021 Node *prev = NULL;
3022 Node *result = orig_mem;
3023 while (prev != result) {
3024 prev = result;
3025 if (result == start_mem)
3026 break; // hit one of our sentinels
3027 if (result->is_Mem()) {
3028 const Type *at = igvn->type(result->in(MemNode::Address));
3029 if (at == Type::TOP)
3030 break; // Dead
3031 assert (at->isa_ptr() != NULL, "pointer type required.");
3032 int idx = C->get_alias_index(at->is_ptr());
3033 if (idx == alias_idx)
3034 break; // Found
3035 if (!is_instance && (at->isa_oopptr() == NULL ||
3036 !at->is_oopptr()->is_known_instance())) {
3037 break; // Do not skip store to general memory slice.
3038 }
3039 result = result->in(MemNode::Memory);
3040 }
3041 if (!is_instance)
3042 continue; // don't search further for non-instance types
3043 // skip over a call which does not affect this memory slice
3044 if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) {
3045 Node *proj_in = result->in(0);
3046 if (proj_in->is_Allocate() && proj_in->_idx == (uint)toop->instance_id()) {
3047 break; // hit one of our sentinels
3048 } else if (proj_in->is_Call()) {
3049 // ArrayCopy node processed here as well
3050 CallNode *call = proj_in->as_Call();
3051 if (!call->may_modify(toop, igvn)) {
3052 result = call->in(TypeFunc::Memory);
3053 }
3054 } else if (proj_in->is_Initialize()) {
3055 AllocateNode* alloc = proj_in->as_Initialize()->allocation();
3056 // Stop if this is the initialization for the object instance which
3057 // which contains this memory slice, otherwise skip over it.
3058 if (alloc == NULL || alloc->_idx != (uint)toop->instance_id()) {
3059 result = proj_in->in(TypeFunc::Memory);
3060 }
3061 } else if (proj_in->is_MemBar()) {
3062 // Check if there is an array copy for a clone
3063 // Step over GC barrier when ReduceInitialCardMarks is disabled
3064 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
3065 Node* control_proj_ac = bs->step_over_gc_barrier(proj_in->in(0));
3066
3067 if (control_proj_ac->is_Proj() && control_proj_ac->in(0)->is_ArrayCopy()) {
3068 // Stop if it is a clone
3069 ArrayCopyNode* ac = control_proj_ac->in(0)->as_ArrayCopy();
3070 if (ac->may_modify(toop, igvn)) {
3071 break;
3072 }
3073 }
3074 result = proj_in->in(TypeFunc::Memory);
3075 }
3076 } else if (result->is_MergeMem()) {
3077 MergeMemNode *mmem = result->as_MergeMem();
3078 result = step_through_mergemem(mmem, alias_idx, toop);
3079 if (result == mmem->base_memory()) {
3080 // Didn't find instance memory, search through general slice recursively.
3081 result = mmem->memory_at(C->get_general_index(alias_idx));
3082 result = find_inst_mem(result, alias_idx, orig_phis);
3083 if (C->failing()) {
3084 return NULL;
3085 }
3086 mmem->set_memory_at(alias_idx, result);
3087 }
3088 } else if (result->is_Phi() &&
3089 C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) {
3090 Node *un = result->as_Phi()->unique_input(igvn);
3091 if (un != NULL) {
3092 orig_phis.append_if_missing(result->as_Phi());
3093 result = un;
3094 } else {
3095 break;
3096 }
3097 } else if (result->is_ClearArray()) {
3098 intptr_t offset;
3099 AllocateNode* alloc = AllocateNode::Ideal_allocation(result->in(3), igvn, offset);
3100
3101 if ((alloc == NULL) || !ClearArrayNode::step_through(&result, (uint)toop->instance_id(), igvn)) {
3102 // Can not bypass initialization of the instance
3103 // we are looking for.
3104 break;
3105 }
3106 // Otherwise skip it (the call updated 'result' value).
3107 } else if (result->Opcode() == Op_SCMemProj) {
3108 Node* mem = result->in(0);
3109 Node* adr = NULL;
3110 if (mem->is_LoadStore()) {
3111 adr = mem->in(MemNode::Address);
3112 } else {
3113 assert(mem->Opcode() == Op_EncodeISOArray ||
3114 mem->Opcode() == Op_StrCompressedCopy, "sanity");
3115 adr = mem->in(3); // Memory edge corresponds to destination array
3116 }
3117 const Type *at = igvn->type(adr);
3118 if (at != Type::TOP) {
3119 assert(at->isa_ptr() != NULL, "pointer type required.");
3120 int idx = C->get_alias_index(at->is_ptr());
3121 if (idx == alias_idx) {
3122 // Assert in debug mode
3123 assert(false, "Object is not scalar replaceable if a LoadStore node accesses its field");
3124 break; // In product mode return SCMemProj node
3125 }
3126 }
3127 result = mem->in(MemNode::Memory);
3128 } else if (result->Opcode() == Op_StrInflatedCopy) {
3129 Node* adr = result->in(3); // Memory edge corresponds to destination array
3130 const Type *at = igvn->type(adr);
3131 if (at != Type::TOP) {
3132 assert(at->isa_ptr() != NULL, "pointer type required.");
3133 int idx = C->get_alias_index(at->is_ptr());
3134 if (idx == alias_idx) {
3135 // Assert in debug mode
3136 assert(false, "Object is not scalar replaceable if a StrInflatedCopy node accesses its field");
3137 break; // In product mode return SCMemProj node
3138 }
3139 }
3140 result = result->in(MemNode::Memory);
3141 }
3142 }
3143 if (result->is_Phi()) {
3144 PhiNode *mphi = result->as_Phi();
3145 assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
3146 const TypePtr *t = mphi->adr_type();
3147 if (!is_instance) {
3148 // Push all non-instance Phis on the orig_phis worklist to update inputs
3149 // during Phase 4 if needed.
3150 orig_phis.append_if_missing(mphi);
3151 } else if (C->get_alias_index(t) != alias_idx) {
3152 // Create a new Phi with the specified alias index type.
3153 result = split_memory_phi(mphi, alias_idx, orig_phis);
3154 }
3155 }
3156 // the result is either MemNode, PhiNode, InitializeNode.
3157 return result;
3158 }
3159
3160 //
3161 // Convert the types of unescaped object to instance types where possible,
3162 // propagate the new type information through the graph, and update memory
3163 // edges and MergeMem inputs to reflect the new type.
3164 //
3165 // We start with allocations (and calls which may be allocations) on alloc_worklist.
3166 // The processing is done in 4 phases:
3167 //
3168 // Phase 1: Process possible allocations from alloc_worklist. Create instance
3169 // types for the CheckCastPP for allocations where possible.
3170 // Propagate the new types through users as follows:
3171 // casts and Phi: push users on alloc_worklist
3172 // AddP: cast Base and Address inputs to the instance type
3173 // push any AddP users on alloc_worklist and push any memnode
3174 // users onto memnode_worklist.
3175 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
3176 // search the Memory chain for a store with the appropriate type
3177 // address type. If a Phi is found, create a new version with
3178 // the appropriate memory slices from each of the Phi inputs.
3179 // For stores, process the users as follows:
3180 // MemNode: push on memnode_worklist
3181 // MergeMem: push on mergemem_worklist
3182 // Phase 3: Process MergeMem nodes from mergemem_worklist. Walk each memory slice
3183 // moving the first node encountered of each instance type to the
3184 // the input corresponding to its alias index.
3185 // appropriate memory slice.
3186 // Phase 4: Update the inputs of non-instance memory Phis and the Memory input of memnodes.
3187 //
3188 // In the following example, the CheckCastPP nodes are the cast of allocation
3189 // results and the allocation of node 29 is unescaped and eligible to be an
3190 // instance type.
3191 //
3192 // We start with:
3193 //
3194 // 7 Parm #memory
3195 // 10 ConI "12"
3196 // 19 CheckCastPP "Foo"
3197 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
3198 // 29 CheckCastPP "Foo"
3199 // 30 AddP _ 29 29 10 Foo+12 alias_index=4
3200 //
3201 // 40 StoreP 25 7 20 ... alias_index=4
3202 // 50 StoreP 35 40 30 ... alias_index=4
3203 // 60 StoreP 45 50 20 ... alias_index=4
3204 // 70 LoadP _ 60 30 ... alias_index=4
3205 // 80 Phi 75 50 60 Memory alias_index=4
3206 // 90 LoadP _ 80 30 ... alias_index=4
3207 // 100 LoadP _ 80 20 ... alias_index=4
3208 //
3209 //
3210 // Phase 1 creates an instance type for node 29 assigning it an instance id of 24
3211 // and creating a new alias index for node 30. This gives:
3212 //
3213 // 7 Parm #memory
3214 // 10 ConI "12"
3215 // 19 CheckCastPP "Foo"
3216 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
3217 // 29 CheckCastPP "Foo" iid=24
3218 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
3219 //
3220 // 40 StoreP 25 7 20 ... alias_index=4
3221 // 50 StoreP 35 40 30 ... alias_index=6
3222 // 60 StoreP 45 50 20 ... alias_index=4
3223 // 70 LoadP _ 60 30 ... alias_index=6
3224 // 80 Phi 75 50 60 Memory alias_index=4
3225 // 90 LoadP _ 80 30 ... alias_index=6
3226 // 100 LoadP _ 80 20 ... alias_index=4
3227 //
3228 // In phase 2, new memory inputs are computed for the loads and stores,
3229 // And a new version of the phi is created. In phase 4, the inputs to
3230 // node 80 are updated and then the memory nodes are updated with the
3231 // values computed in phase 2. This results in:
3232 //
3233 // 7 Parm #memory
3234 // 10 ConI "12"
3235 // 19 CheckCastPP "Foo"
3236 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
3237 // 29 CheckCastPP "Foo" iid=24
3238 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
3239 //
3240 // 40 StoreP 25 7 20 ... alias_index=4
3241 // 50 StoreP 35 7 30 ... alias_index=6
3242 // 60 StoreP 45 40 20 ... alias_index=4
3243 // 70 LoadP _ 50 30 ... alias_index=6
3244 // 80 Phi 75 40 60 Memory alias_index=4
3245 // 120 Phi 75 50 50 Memory alias_index=6
3246 // 90 LoadP _ 120 30 ... alias_index=6
3247 // 100 LoadP _ 80 20 ... alias_index=4
3248 //
3249 void ConnectionGraph::split_unique_types(GrowableArray<Node *> &alloc_worklist, GrowableArray<ArrayCopyNode*> &arraycopy_worklist) {
3250 GrowableArray<Node *> memnode_worklist;
3251 GrowableArray<PhiNode *> orig_phis;
3252 PhaseIterGVN *igvn = _igvn;
3253 uint new_index_start = (uint) _compile->num_alias_types();
3254 Arena* arena = Thread::current()->resource_area();
3255 VectorSet visited(arena);
3256 ideal_nodes.clear(); // Reset for use with set_map/get_map.
3257 uint unique_old = _compile->unique();
3258
3259 // Phase 1: Process possible allocations from alloc_worklist.
3260 // Create instance types for the CheckCastPP for allocations where possible.
3261 //
3262 // (Note: don't forget to change the order of the second AddP node on
3263 // the alloc_worklist if the order of the worklist processing is changed,
3264 // see the comment in find_second_addp().)
3265 //
3266 while (alloc_worklist.length() != 0) {
3267 Node *n = alloc_worklist.pop();
3268 uint ni = n->_idx;
3269 if (n->is_Call()) {
3270 CallNode *alloc = n->as_Call();
3271 // copy escape information to call node
3272 PointsToNode* ptn = ptnode_adr(alloc->_idx);
3273 PointsToNode::EscapeState es = ptn->escape_state();
3274 // We have an allocation or call which returns a Java object,
3275 // see if it is unescaped.
3276 if (es != PointsToNode::NoEscape || !ptn->scalar_replaceable())
3277 continue;
3278 // Find CheckCastPP for the allocate or for the return value of a call
3279 n = alloc->result_cast();
3280 if (n == NULL) { // No uses except Initialize node
3281 if (alloc->is_Allocate()) {
3282 // Set the scalar_replaceable flag for allocation
3283 // so it could be eliminated if it has no uses.
3284 alloc->as_Allocate()->_is_scalar_replaceable = true;
3285 }
3286 if (alloc->is_CallStaticJava()) {
3287 // Set the scalar_replaceable flag for boxing method
3288 // so it could be eliminated if it has no uses.
3289 alloc->as_CallStaticJava()->_is_scalar_replaceable = true;
3290 }
3291 continue;
3292 }
3293 if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
3294 assert(!alloc->is_Allocate(), "allocation should have unique type");
3295 continue;
3296 }
3297
3298 // The inline code for Object.clone() casts the allocation result to
3299 // java.lang.Object and then to the actual type of the allocated
3300 // object. Detect this case and use the second cast.
3301 // Also detect j.l.reflect.Array.newInstance(jobject, jint) case when
3302 // the allocation result is cast to java.lang.Object and then
3303 // to the actual Array type.
3304 if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL
3305 && (alloc->is_AllocateArray() ||
3306 igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeKlassPtr::OBJECT)) {
3307 Node *cast2 = NULL;
3308 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3309 Node *use = n->fast_out(i);
3310 if (use->is_CheckCastPP()) {
3311 cast2 = use;
3312 break;
3313 }
3314 }
3315 if (cast2 != NULL) {
3316 n = cast2;
3317 } else {
3318 // Non-scalar replaceable if the allocation type is unknown statically
3319 // (reflection allocation), the object can't be restored during
3320 // deoptimization without precise type.
3321 continue;
3322 }
3323 }
3324
3325 const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
3326 if (t == NULL)
3327 continue; // not a TypeOopPtr
3328 if (!t->klass_is_exact())
3329 continue; // not an unique type
3330
3331 if (alloc->is_Allocate()) {
3332 // Set the scalar_replaceable flag for allocation
3333 // so it could be eliminated.
3334 alloc->as_Allocate()->_is_scalar_replaceable = true;
3335 }
3336 if (alloc->is_CallStaticJava()) {
3337 // Set the scalar_replaceable flag for boxing method
3338 // so it could be eliminated.
3339 alloc->as_CallStaticJava()->_is_scalar_replaceable = true;
3340 }
3341 set_escape_state(ptnode_adr(n->_idx), es); // CheckCastPP escape state
3342 // in order for an object to be scalar-replaceable, it must be:
3343 // - a direct allocation (not a call returning an object)
3344 // - non-escaping
3345 // - eligible to be a unique type
3346 // - not determined to be ineligible by escape analysis
3347 set_map(alloc, n);
3348 set_map(n, alloc);
3349 const TypeOopPtr* tinst = t->cast_to_instance_id(ni);
3350 igvn->hash_delete(n);
3351 igvn->set_type(n, tinst);
3352 n->raise_bottom_type(tinst);
3353 igvn->hash_insert(n);
3354 record_for_optimizer(n);
3355 // Allocate an alias index for the header fields. Accesses to
3356 // the header emitted during macro expansion wouldn't have
3357 // correct memory state otherwise.
3358 _compile->get_alias_index(tinst->add_offset(oopDesc::mark_offset_in_bytes()));
3359 _compile->get_alias_index(tinst->add_offset(oopDesc::klass_offset_in_bytes()));
3360 if (alloc->is_Allocate() && (t->isa_instptr() || t->isa_aryptr())) {
3361
3362 // First, put on the worklist all Field edges from Connection Graph
3363 // which is more accurate than putting immediate users from Ideal Graph.
3364 for (EdgeIterator e(ptn); e.has_next(); e.next()) {
3365 PointsToNode* tgt = e.get();
3366 if (tgt->is_Arraycopy()) {
3367 continue;
3368 }
3369 Node* use = tgt->ideal_node();
3370 assert(tgt->is_Field() && use->is_AddP(),
3371 "only AddP nodes are Field edges in CG");
3372 if (use->outcnt() > 0) { // Don't process dead nodes
3373 Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
3374 if (addp2 != NULL) {
3375 assert(alloc->is_AllocateArray(),"array allocation was expected");
3376 alloc_worklist.append_if_missing(addp2);
3377 }
3378 alloc_worklist.append_if_missing(use);
3379 }
3380 }
3381
3382 // An allocation may have an Initialize which has raw stores. Scan
3383 // the users of the raw allocation result and push AddP users
3384 // on alloc_worklist.
3385 Node *raw_result = alloc->proj_out_or_null(TypeFunc::Parms);
3386 assert (raw_result != NULL, "must have an allocation result");
3387 for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
3388 Node *use = raw_result->fast_out(i);
3389 if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
3390 Node* addp2 = find_second_addp(use, raw_result);
3391 if (addp2 != NULL) {
3392 assert(alloc->is_AllocateArray(),"array allocation was expected");
3393 alloc_worklist.append_if_missing(addp2);
3394 }
3395 alloc_worklist.append_if_missing(use);
3396 } else if (use->is_MemBar()) {
3397 memnode_worklist.append_if_missing(use);
3398 }
3399 }
3400 }
3401 } else if (n->is_AddP()) {
3402 JavaObjectNode* jobj = unique_java_object(get_addp_base(n));
3403 if (jobj == NULL || jobj == phantom_obj) {
3404 #ifdef ASSERT
3405 ptnode_adr(get_addp_base(n)->_idx)->dump();
3406 ptnode_adr(n->_idx)->dump();
3407 assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
3408 #endif
3409 _compile->record_failure(C2Compiler::retry_no_escape_analysis());
3410 return;
3411 }
3412 Node *base = get_map(jobj->idx()); // CheckCastPP node
3413 if (!split_AddP(n, base)) continue; // wrong type from dead path
3414 } else if (n->is_Phi() ||
3415 n->is_CheckCastPP() ||
3416 n->is_EncodeP() ||
3417 n->is_DecodeN() ||
3418 (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
3419 if (visited.test_set(n->_idx)) {
3420 assert(n->is_Phi(), "loops only through Phi's");
3421 continue; // already processed
3422 }
3423 JavaObjectNode* jobj = unique_java_object(n);
3424 if (jobj == NULL || jobj == phantom_obj) {
3425 #ifdef ASSERT
3426 ptnode_adr(n->_idx)->dump();
3427 assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
3428 #endif
3429 _compile->record_failure(C2Compiler::retry_no_escape_analysis());
3430 return;
3431 } else {
3432 Node *val = get_map(jobj->idx()); // CheckCastPP node
3433 TypeNode *tn = n->as_Type();
3434 const TypeOopPtr* tinst = igvn->type(val)->isa_oopptr();
3435 assert(tinst != NULL && tinst->is_known_instance() &&
3436 tinst->instance_id() == jobj->idx() , "instance type expected.");
3437
3438 const Type *tn_type = igvn->type(tn);
3439 const TypeOopPtr *tn_t;
3440 if (tn_type->isa_narrowoop()) {
3441 tn_t = tn_type->make_ptr()->isa_oopptr();
3442 } else {
3443 tn_t = tn_type->isa_oopptr();
3444 }
3445 if (tn_t != NULL && tinst->klass()->is_subtype_of(tn_t->klass())) {
3446 if (tn_type->isa_narrowoop()) {
3447 tn_type = tinst->make_narrowoop();
3448 } else {
3449 tn_type = tinst;
3450 }
3451 igvn->hash_delete(tn);
3452 igvn->set_type(tn, tn_type);
3453 tn->set_type(tn_type);
3454 igvn->hash_insert(tn);
3455 record_for_optimizer(n);
3456 } else {
3457 assert(tn_type == TypePtr::NULL_PTR ||
3458 tn_t != NULL && !tinst->klass()->is_subtype_of(tn_t->klass()),
3459 "unexpected type");
3460 continue; // Skip dead path with different type
3461 }
3462 }
3463 } else {
3464 debug_only(n->dump();)
3465 assert(false, "EA: unexpected node");
3466 continue;
3467 }
3468 // push allocation's users on appropriate worklist
3469 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3470 Node *use = n->fast_out(i);
3471 if(use->is_Mem() && use->in(MemNode::Address) == n) {
3472 // Load/store to instance's field
3473 memnode_worklist.append_if_missing(use);
3474 } else if (use->is_MemBar()) {
3475 if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
3476 memnode_worklist.append_if_missing(use);
3477 }
3478 } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
3479 Node* addp2 = find_second_addp(use, n);
3480 if (addp2 != NULL) {
3481 alloc_worklist.append_if_missing(addp2);
3482 }
3483 alloc_worklist.append_if_missing(use);
3484 } else if (use->is_Phi() ||
3485 use->is_CheckCastPP() ||
3486 use->is_EncodeNarrowPtr() ||
3487 use->is_DecodeNarrowPtr() ||
3488 (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
3489 alloc_worklist.append_if_missing(use);
3490 #ifdef ASSERT
3491 } else if (use->is_Mem()) {
3492 assert(use->in(MemNode::Address) != n, "EA: missing allocation reference path");
3493 } else if (use->is_MergeMem()) {
3494 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3495 } else if (use->is_SafePoint()) {
3496 // Look for MergeMem nodes for calls which reference unique allocation
3497 // (through CheckCastPP nodes) even for debug info.
3498 Node* m = use->in(TypeFunc::Memory);
3499 if (m->is_MergeMem()) {
3500 assert(_mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3501 }
3502 } else if (use->Opcode() == Op_EncodeISOArray) {
3503 if (use->in(MemNode::Memory) == n || use->in(3) == n) {
3504 // EncodeISOArray overwrites destination array
3505 memnode_worklist.append_if_missing(use);
3506 }
3507 } else {
3508 uint op = use->Opcode();
3509 if ((op == Op_StrCompressedCopy || op == Op_StrInflatedCopy) &&
3510 (use->in(MemNode::Memory) == n)) {
3511 // They overwrite memory edge corresponding to destination array,
3512 memnode_worklist.append_if_missing(use);
3513 } else if (!(op == Op_CmpP || op == Op_Conv2B ||
3514 op == Op_CastP2X || op == Op_StoreCM ||
3515 op == Op_FastLock || op == Op_AryEq || op == Op_StrComp || op == Op_HasNegatives ||
3516 op == Op_StrCompressedCopy || op == Op_StrInflatedCopy ||
3517 op == Op_StrEquals || op == Op_StrIndexOf || op == Op_StrIndexOfChar ||
3518 op == Op_SubTypeCheck ||
3519 BarrierSet::barrier_set()->barrier_set_c2()->is_gc_barrier_node(use))) {
3520 n->dump();
3521 use->dump();
3522 assert(false, "EA: missing allocation reference path");
3523 }
3524 #endif
3525 }
3526 }
3527
3528 }
3529
3530 // Go over all ArrayCopy nodes and if one of the inputs has a unique
3531 // type, record it in the ArrayCopy node so we know what memory this
3532 // node uses/modified.
3533 for (int next = 0; next < arraycopy_worklist.length(); next++) {
3534 ArrayCopyNode* ac = arraycopy_worklist.at(next);
3535 Node* dest = ac->in(ArrayCopyNode::Dest);
3536 if (dest->is_AddP()) {
3537 dest = get_addp_base(dest);
3538 }
3539 JavaObjectNode* jobj = unique_java_object(dest);
3540 if (jobj != NULL) {
3541 Node *base = get_map(jobj->idx());
3542 if (base != NULL) {
3543 const TypeOopPtr *base_t = _igvn->type(base)->isa_oopptr();
3544 ac->_dest_type = base_t;
3545 }
3546 }
3547 Node* src = ac->in(ArrayCopyNode::Src);
3548 if (src->is_AddP()) {
3549 src = get_addp_base(src);
3550 }
3551 jobj = unique_java_object(src);
3552 if (jobj != NULL) {
3553 Node* base = get_map(jobj->idx());
3554 if (base != NULL) {
3555 const TypeOopPtr *base_t = _igvn->type(base)->isa_oopptr();
3556 ac->_src_type = base_t;
3557 }
3558 }
3559 }
3560
3561 // New alias types were created in split_AddP().
3562 uint new_index_end = (uint) _compile->num_alias_types();
3563 assert(unique_old == _compile->unique(), "there should be no new ideal nodes after Phase 1");
3564
3565 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
3566 // compute new values for Memory inputs (the Memory inputs are not
3567 // actually updated until phase 4.)
3568 if (memnode_worklist.length() == 0)
3569 return; // nothing to do
3570 while (memnode_worklist.length() != 0) {
3571 Node *n = memnode_worklist.pop();
3572 if (visited.test_set(n->_idx))
3573 continue;
3574 if (n->is_Phi() || n->is_ClearArray()) {
3575 // we don't need to do anything, but the users must be pushed
3576 } else if (n->is_MemBar()) { // Initialize, MemBar nodes
3577 // we don't need to do anything, but the users must be pushed
3578 n = n->as_MemBar()->proj_out_or_null(TypeFunc::Memory);
3579 if (n == NULL)
3580 continue;
3581 } else if (n->Opcode() == Op_StrCompressedCopy ||
3582 n->Opcode() == Op_EncodeISOArray) {
3583 // get the memory projection
3584 n = n->find_out_with(Op_SCMemProj);
3585 assert(n != NULL && n->Opcode() == Op_SCMemProj, "memory projection required");
3586 } else {
3587 assert(n->is_Mem(), "memory node required.");
3588 Node *addr = n->in(MemNode::Address);
3589 const Type *addr_t = igvn->type(addr);
3590 if (addr_t == Type::TOP)
3591 continue;
3592 assert (addr_t->isa_ptr() != NULL, "pointer type required.");
3593 int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
3594 assert ((uint)alias_idx < new_index_end, "wrong alias index");
3595 Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis);
3596 if (_compile->failing()) {
3597 return;
3598 }
3599 if (mem != n->in(MemNode::Memory)) {
3600 // We delay the memory edge update since we need old one in
3601 // MergeMem code below when instances memory slices are separated.
3602 set_map(n, mem);
3603 }
3604 if (n->is_Load()) {
3605 continue; // don't push users
3606 } else if (n->is_LoadStore()) {
3607 // get the memory projection
3608 n = n->find_out_with(Op_SCMemProj);
3609 assert(n != NULL && n->Opcode() == Op_SCMemProj, "memory projection required");
3610 }
3611 }
3612 // push user on appropriate worklist
3613 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3614 Node *use = n->fast_out(i);
3615 if (use->is_Phi() || use->is_ClearArray()) {
3616 memnode_worklist.append_if_missing(use);
3617 } else if (use->is_Mem() && use->in(MemNode::Memory) == n) {
3618 if (use->Opcode() == Op_StoreCM) // Ignore cardmark stores
3619 continue;
3620 memnode_worklist.append_if_missing(use);
3621 } else if (use->is_MemBar()) {
3622 if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
3623 memnode_worklist.append_if_missing(use);
3624 }
3625 #ifdef ASSERT
3626 } else if(use->is_Mem()) {
3627 assert(use->in(MemNode::Memory) != n, "EA: missing memory path");
3628 } else if (use->is_MergeMem()) {
3629 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3630 } else if (use->Opcode() == Op_EncodeISOArray) {
3631 if (use->in(MemNode::Memory) == n || use->in(3) == n) {
3632 // EncodeISOArray overwrites destination array
3633 memnode_worklist.append_if_missing(use);
3634 }
3635 } else {
3636 uint op = use->Opcode();
3637 if ((use->in(MemNode::Memory) == n) &&
3638 (op == Op_StrCompressedCopy || op == Op_StrInflatedCopy)) {
3639 // They overwrite memory edge corresponding to destination array,
3640 memnode_worklist.append_if_missing(use);
3641 } else if (!(BarrierSet::barrier_set()->barrier_set_c2()->is_gc_barrier_node(use) ||
3642 op == Op_AryEq || op == Op_StrComp || op == Op_HasNegatives ||
3643 op == Op_StrCompressedCopy || op == Op_StrInflatedCopy ||
3644 op == Op_StrEquals || op == Op_StrIndexOf || op == Op_StrIndexOfChar)) {
3645 n->dump();
3646 use->dump();
3647 assert(false, "EA: missing memory path");
3648 }
3649 #endif
3650 }
3651 }
3652 }
3653
3654 // Phase 3: Process MergeMem nodes from mergemem_worklist.
3655 // Walk each memory slice moving the first node encountered of each
3656 // instance type to the the input corresponding to its alias index.
3657 uint length = _mergemem_worklist.length();
3658 for( uint next = 0; next < length; ++next ) {
3659 MergeMemNode* nmm = _mergemem_worklist.at(next);
3660 assert(!visited.test_set(nmm->_idx), "should not be visited before");
3661 // Note: we don't want to use MergeMemStream here because we only want to
3662 // scan inputs which exist at the start, not ones we add during processing.
3663 // Note 2: MergeMem may already contains instance memory slices added
3664 // during find_inst_mem() call when memory nodes were processed above.
3665 igvn->hash_delete(nmm);
3666 uint nslices = MIN2(nmm->req(), new_index_start);
3667 for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) {
3668 Node* mem = nmm->in(i);
3669 Node* cur = NULL;
3670 if (mem == NULL || mem->is_top())
3671 continue;
3672 // First, update mergemem by moving memory nodes to corresponding slices
3673 // if their type became more precise since this mergemem was created.
3674 while (mem->is_Mem()) {
3675 const Type *at = igvn->type(mem->in(MemNode::Address));
3676 if (at != Type::TOP) {
3677 assert (at->isa_ptr() != NULL, "pointer type required.");
3678 uint idx = (uint)_compile->get_alias_index(at->is_ptr());
3679 if (idx == i) {
3680 if (cur == NULL)
3681 cur = mem;
3682 } else {
3683 if (idx >= nmm->req() || nmm->is_empty_memory(nmm->in(idx))) {
3684 nmm->set_memory_at(idx, mem);
3685 }
3686 }
3687 }
3688 mem = mem->in(MemNode::Memory);
3689 }
3690 nmm->set_memory_at(i, (cur != NULL) ? cur : mem);
3691 // Find any instance of the current type if we haven't encountered
3692 // already a memory slice of the instance along the memory chain.
3693 for (uint ni = new_index_start; ni < new_index_end; ni++) {
3694 if((uint)_compile->get_general_index(ni) == i) {
3695 Node *m = (ni >= nmm->req()) ? nmm->empty_memory() : nmm->in(ni);
3696 if (nmm->is_empty_memory(m)) {
3697 Node* result = find_inst_mem(mem, ni, orig_phis);
3698 if (_compile->failing()) {
3699 return;
3700 }
3701 nmm->set_memory_at(ni, result);
3702 }
3703 }
3704 }
3705 }
3706 // Find the rest of instances values
3707 for (uint ni = new_index_start; ni < new_index_end; ni++) {
3708 const TypeOopPtr *tinst = _compile->get_adr_type(ni)->isa_oopptr();
3709 Node* result = step_through_mergemem(nmm, ni, tinst);
3710 if (result == nmm->base_memory()) {
3711 // Didn't find instance memory, search through general slice recursively.
3712 result = nmm->memory_at(_compile->get_general_index(ni));
3713 result = find_inst_mem(result, ni, orig_phis);
3714 if (_compile->failing()) {
3715 return;
3716 }
3717 nmm->set_memory_at(ni, result);
3718 }
3719 }
3720 igvn->hash_insert(nmm);
3721 record_for_optimizer(nmm);
3722 }
3723
3724 // Phase 4: Update the inputs of non-instance memory Phis and
3725 // the Memory input of memnodes
3726 // First update the inputs of any non-instance Phi's from
3727 // which we split out an instance Phi. Note we don't have
3728 // to recursively process Phi's encounted on the input memory
3729 // chains as is done in split_memory_phi() since they will
3730 // also be processed here.
3731 for (int j = 0; j < orig_phis.length(); j++) {
3732 PhiNode *phi = orig_phis.at(j);
3733 int alias_idx = _compile->get_alias_index(phi->adr_type());
3734 igvn->hash_delete(phi);
3735 for (uint i = 1; i < phi->req(); i++) {
3736 Node *mem = phi->in(i);
3737 Node *new_mem = find_inst_mem(mem, alias_idx, orig_phis);
3738 if (_compile->failing()) {
3739 return;
3740 }
3741 if (mem != new_mem) {
3742 phi->set_req(i, new_mem);
3743 }
3744 }
3745 igvn->hash_insert(phi);
3746 record_for_optimizer(phi);
3747 }
3748
3749 // Update the memory inputs of MemNodes with the value we computed
3750 // in Phase 2 and move stores memory users to corresponding memory slices.
3751 // Disable memory split verification code until the fix for 6984348.
3752 // Currently it produces false negative results since it does not cover all cases.
3753 #if 0 // ifdef ASSERT
3754 visited.Reset();
3755 Node_Stack old_mems(arena, _compile->unique() >> 2);
3756 #endif
3757 for (uint i = 0; i < ideal_nodes.size(); i++) {
3758 Node* n = ideal_nodes.at(i);
3759 Node* nmem = get_map(n->_idx);
3760 assert(nmem != NULL, "sanity");
3761 if (n->is_Mem()) {
3762 #if 0 // ifdef ASSERT
3763 Node* old_mem = n->in(MemNode::Memory);
3764 if (!visited.test_set(old_mem->_idx)) {
3765 old_mems.push(old_mem, old_mem->outcnt());
3766 }
3767 #endif
3768 assert(n->in(MemNode::Memory) != nmem, "sanity");
3769 if (!n->is_Load()) {
3770 // Move memory users of a store first.
3771 move_inst_mem(n, orig_phis);
3772 }
3773 // Now update memory input
3774 igvn->hash_delete(n);
3775 n->set_req(MemNode::Memory, nmem);
3776 igvn->hash_insert(n);
3777 record_for_optimizer(n);
3778 } else {
3779 assert(n->is_Allocate() || n->is_CheckCastPP() ||
3780 n->is_AddP() || n->is_Phi(), "unknown node used for set_map()");
3781 }
3782 }
3783 #if 0 // ifdef ASSERT
3784 // Verify that memory was split correctly
3785 while (old_mems.is_nonempty()) {
3786 Node* old_mem = old_mems.node();
3787 uint old_cnt = old_mems.index();
3788 old_mems.pop();
3789 assert(old_cnt == old_mem->outcnt(), "old mem could be lost");
3790 }
3791 #endif
3792 }
3793
3794 #ifndef PRODUCT
3795 static const char *node_type_names[] = {
3796 "UnknownType",
3797 "JavaObject",
3798 "LocalVar",
3799 "Field",
3800 "Arraycopy"
3801 };
3802
3803 static const char *esc_names[] = {
3804 "UnknownEscape",
3805 "NoEscape",
3806 "ArgEscape",
3807 "GlobalEscape"
3808 };
3809
3810 void PointsToNode::dump(bool print_state) const {
3811 NodeType nt = node_type();
3812 tty->print("%s ", node_type_names[(int) nt]);
3813 if (print_state) {
3814 EscapeState es = escape_state();
3815 EscapeState fields_es = fields_escape_state();
3816 tty->print("%s(%s) ", esc_names[(int)es], esc_names[(int)fields_es]);
3817 if (nt == PointsToNode::JavaObject && !this->scalar_replaceable())
3818 tty->print("NSR ");
3819 }
3820 if (is_Field()) {
3821 FieldNode* f = (FieldNode*)this;
3822 if (f->is_oop())
3823 tty->print("oop ");
3824 if (f->offset() > 0)
3825 tty->print("+%d ", f->offset());
3826 tty->print("(");
3827 for (BaseIterator i(f); i.has_next(); i.next()) {
3828 PointsToNode* b = i.get();
3829 tty->print(" %d%s", b->idx(),(b->is_JavaObject() ? "P" : ""));
3830 }
3831 tty->print(" )");
3832 }
3833 tty->print("[");
3834 for (EdgeIterator i(this); i.has_next(); i.next()) {
3835 PointsToNode* e = i.get();
3836 tty->print(" %d%s%s", e->idx(),(e->is_JavaObject() ? "P" : (e->is_Field() ? "F" : "")), e->is_Arraycopy() ? "cp" : "");
3837 }
3838 tty->print(" [");
3839 for (UseIterator i(this); i.has_next(); i.next()) {
3840 PointsToNode* u = i.get();
3841 bool is_base = false;
3842 if (PointsToNode::is_base_use(u)) {
3843 is_base = true;
3844 u = PointsToNode::get_use_node(u)->as_Field();
3845 }
3846 tty->print(" %d%s%s", u->idx(), is_base ? "b" : "", u->is_Arraycopy() ? "cp" : "");
3847 }
3848 tty->print(" ]] ");
3849 if (_node == NULL)
3850 tty->print_cr("<null>");
3851 else
3852 _node->dump();
3853 }
3854
3855 void ConnectionGraph::dump(GrowableArray<PointsToNode*>& ptnodes_worklist) {
3856 bool first = true;
3857 int ptnodes_length = ptnodes_worklist.length();
3858 for (int i = 0; i < ptnodes_length; i++) {
3859 PointsToNode *ptn = ptnodes_worklist.at(i);
3860 if (ptn == NULL || !ptn->is_JavaObject())
3861 continue;
3862 PointsToNode::EscapeState es = ptn->escape_state();
3863 if ((es != PointsToNode::NoEscape) && !Verbose) {
3864 continue;
3865 }
3866 Node* n = ptn->ideal_node();
3867 if (n->is_Allocate() || (n->is_CallStaticJava() &&
3868 n->as_CallStaticJava()->is_boxing_method())) {
3869 if (first) {
3870 tty->cr();
3871 tty->print("======== Connection graph for ");
3872 _compile->method()->print_short_name();
3873 tty->cr();
3874 first = false;
3875 }
3876 ptn->dump();
3877 // Print all locals and fields which reference this allocation
3878 for (UseIterator j(ptn); j.has_next(); j.next()) {
3879 PointsToNode* use = j.get();
3880 if (use->is_LocalVar()) {
3881 use->dump(Verbose);
3882 } else if (Verbose) {
3883 use->dump();
3884 }
3885 }
3886 tty->cr();
3887 }
3888 }
3889 }
3890 #endif
3891
3892 void ConnectionGraph::record_for_optimizer(Node *n) {
3893 _igvn->_worklist.push(n);
3894 _igvn->add_users_to_worklist(n);
3895 }