1 /*
2 * Copyright (c) 2005, 2025, 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 "ci/bcEscapeAnalyzer.hpp"
26 #include "compiler/compileLog.hpp"
27 #include "gc/shared/barrierSet.hpp"
28 #include "gc/shared/c2/barrierSetC2.hpp"
29 #include "libadt/vectset.hpp"
30 #include "memory/allocation.hpp"
31 #include "memory/resourceArea.hpp"
32 #include "opto/c2compiler.hpp"
33 #include "opto/arraycopynode.hpp"
34 #include "opto/callnode.hpp"
35 #include "opto/cfgnode.hpp"
36 #include "opto/compile.hpp"
37 #include "opto/escape.hpp"
38 #include "opto/macro.hpp"
39 #include "opto/locknode.hpp"
40 #include "opto/phaseX.hpp"
41 #include "opto/movenode.hpp"
42 #include "opto/narrowptrnode.hpp"
43 #include "opto/castnode.hpp"
44 #include "opto/rootnode.hpp"
45 #include "utilities/macros.hpp"
46
47 ConnectionGraph::ConnectionGraph(Compile * C, PhaseIterGVN *igvn, int invocation) :
48 // If ReduceAllocationMerges is enabled we might call split_through_phi during
49 // split_unique_types and that will create additional nodes that need to be
50 // pushed to the ConnectionGraph. The code below bumps the initial capacity of
51 // _nodes by 10% to account for these additional nodes. If capacity is exceeded
52 // the array will be reallocated.
53 _nodes(C->comp_arena(), C->do_reduce_allocation_merges() ? C->unique()*1.10 : C->unique(), C->unique(), nullptr),
54 _in_worklist(C->comp_arena()),
55 _next_pidx(0),
56 _collecting(true),
57 _verify(false),
58 _compile(C),
59 _igvn(igvn),
60 _invocation(invocation),
61 _build_iterations(0),
62 _build_time(0.),
63 _node_map(C->comp_arena()) {
64 // Add unknown java object.
65 add_java_object(C->top(), PointsToNode::GlobalEscape);
66 phantom_obj = ptnode_adr(C->top()->_idx)->as_JavaObject();
67 set_not_scalar_replaceable(phantom_obj NOT_PRODUCT(COMMA "Phantom object"));
68 // Add ConP and ConN null oop nodes
69 Node* oop_null = igvn->zerocon(T_OBJECT);
70 assert(oop_null->_idx < nodes_size(), "should be created already");
71 add_java_object(oop_null, PointsToNode::NoEscape);
72 null_obj = ptnode_adr(oop_null->_idx)->as_JavaObject();
73 set_not_scalar_replaceable(null_obj NOT_PRODUCT(COMMA "Null object"));
74 if (UseCompressedOops) {
75 Node* noop_null = igvn->zerocon(T_NARROWOOP);
76 assert(noop_null->_idx < nodes_size(), "should be created already");
77 map_ideal_node(noop_null, null_obj);
78 }
79 }
80
81 bool ConnectionGraph::has_candidates(Compile *C) {
82 // EA brings benefits only when the code has allocations and/or locks which
83 // are represented by ideal Macro nodes.
84 int cnt = C->macro_count();
85 for (int i = 0; i < cnt; i++) {
86 Node *n = C->macro_node(i);
87 if (n->is_Allocate()) {
88 return true;
89 }
90 if (n->is_Lock()) {
91 Node* obj = n->as_Lock()->obj_node()->uncast();
92 if (!(obj->is_Parm() || obj->is_Con())) {
93 return true;
94 }
95 }
96 if (n->is_CallStaticJava() &&
97 n->as_CallStaticJava()->is_boxing_method()) {
98 return true;
99 }
100 }
101 return false;
102 }
103
104 void ConnectionGraph::do_analysis(Compile *C, PhaseIterGVN *igvn) {
105 Compile::TracePhase tp(Phase::_t_escapeAnalysis);
106 ResourceMark rm;
107
108 // Add ConP and ConN null oop nodes before ConnectionGraph construction
109 // to create space for them in ConnectionGraph::_nodes[].
110 Node* oop_null = igvn->zerocon(T_OBJECT);
111 Node* noop_null = igvn->zerocon(T_NARROWOOP);
112 int invocation = 0;
113 if (C->congraph() != nullptr) {
114 invocation = C->congraph()->_invocation + 1;
115 }
116 ConnectionGraph* congraph = new(C->comp_arena()) ConnectionGraph(C, igvn, invocation);
117 // Perform escape analysis
118 if (congraph->compute_escape()) {
119 // There are non escaping objects.
120 C->set_congraph(congraph);
121 }
122 // Cleanup.
123 if (oop_null->outcnt() == 0) {
124 igvn->hash_delete(oop_null);
125 }
126 if (noop_null->outcnt() == 0) {
127 igvn->hash_delete(noop_null);
128 }
129 }
130
131 bool ConnectionGraph::compute_escape() {
132 Compile* C = _compile;
133 PhaseGVN* igvn = _igvn;
134
135 // Worklists used by EA.
136 Unique_Node_List delayed_worklist;
137 Unique_Node_List reducible_merges;
138 GrowableArray<Node*> alloc_worklist;
139 GrowableArray<Node*> ptr_cmp_worklist;
140 GrowableArray<MemBarStoreStoreNode*> storestore_worklist;
141 GrowableArray<ArrayCopyNode*> arraycopy_worklist;
142 GrowableArray<PointsToNode*> ptnodes_worklist;
143 GrowableArray<JavaObjectNode*> java_objects_worklist;
144 GrowableArray<JavaObjectNode*> non_escaped_allocs_worklist;
145 GrowableArray<FieldNode*> oop_fields_worklist;
146 GrowableArray<SafePointNode*> sfn_worklist;
147 GrowableArray<MergeMemNode*> mergemem_worklist;
148 DEBUG_ONLY( GrowableArray<Node*> addp_worklist; )
149
150 { Compile::TracePhase tp(Phase::_t_connectionGraph);
151
152 // 1. Populate Connection Graph (CG) with PointsTo nodes.
153 ideal_nodes.map(C->live_nodes(), nullptr); // preallocate space
154 // Initialize worklist
155 if (C->root() != nullptr) {
156 ideal_nodes.push(C->root());
157 }
158 // Processed ideal nodes are unique on ideal_nodes list
159 // but several ideal nodes are mapped to the phantom_obj.
160 // To avoid duplicated entries on the following worklists
161 // add the phantom_obj only once to them.
162 ptnodes_worklist.append(phantom_obj);
163 java_objects_worklist.append(phantom_obj);
164 for( uint next = 0; next < ideal_nodes.size(); ++next ) {
165 Node* n = ideal_nodes.at(next);
166 // Create PointsTo nodes and add them to Connection Graph. Called
167 // only once per ideal node since ideal_nodes is Unique_Node list.
168 add_node_to_connection_graph(n, &delayed_worklist);
169 PointsToNode* ptn = ptnode_adr(n->_idx);
170 if (ptn != nullptr && ptn != phantom_obj) {
171 ptnodes_worklist.append(ptn);
172 if (ptn->is_JavaObject()) {
173 java_objects_worklist.append(ptn->as_JavaObject());
174 if ((n->is_Allocate() || n->is_CallStaticJava()) &&
175 (ptn->escape_state() < PointsToNode::GlobalEscape)) {
176 // Only allocations and java static calls results are interesting.
177 non_escaped_allocs_worklist.append(ptn->as_JavaObject());
178 }
179 } else if (ptn->is_Field() && ptn->as_Field()->is_oop()) {
180 oop_fields_worklist.append(ptn->as_Field());
181 }
182 }
183 // Collect some interesting nodes for further use.
184 switch (n->Opcode()) {
185 case Op_MergeMem:
186 // Collect all MergeMem nodes to add memory slices for
187 // scalar replaceable objects in split_unique_types().
188 mergemem_worklist.append(n->as_MergeMem());
189 break;
190 case Op_CmpP:
191 case Op_CmpN:
192 // Collect compare pointers nodes.
193 if (OptimizePtrCompare) {
194 ptr_cmp_worklist.append(n);
195 }
196 break;
197 case Op_MemBarStoreStore:
198 // Collect all MemBarStoreStore nodes so that depending on the
199 // escape status of the associated Allocate node some of them
200 // may be eliminated.
201 if (!UseStoreStoreForCtor || n->req() > MemBarNode::Precedent) {
202 storestore_worklist.append(n->as_MemBarStoreStore());
203 }
204 break;
205 case Op_MemBarRelease:
206 if (n->req() > MemBarNode::Precedent) {
207 record_for_optimizer(n);
208 }
209 break;
210 #ifdef ASSERT
211 case Op_AddP:
212 // Collect address nodes for graph verification.
213 addp_worklist.append(n);
214 break;
215 #endif
216 case Op_ArrayCopy:
217 // Keep a list of ArrayCopy nodes so if one of its input is non
218 // escaping, we can record a unique type
219 arraycopy_worklist.append(n->as_ArrayCopy());
220 break;
221 default:
222 // not interested now, ignore...
223 break;
224 }
225 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
226 Node* m = n->fast_out(i); // Get user
227 ideal_nodes.push(m);
228 }
229 if (n->is_SafePoint()) {
230 sfn_worklist.append(n->as_SafePoint());
231 }
232 }
233
234 #ifndef PRODUCT
235 if (_compile->directive()->TraceEscapeAnalysisOption) {
236 tty->print("+++++ Initial worklist for ");
237 _compile->method()->print_name();
238 tty->print_cr(" (ea_inv=%d)", _invocation);
239 for (int i = 0; i < ptnodes_worklist.length(); i++) {
240 PointsToNode* ptn = ptnodes_worklist.at(i);
241 ptn->dump();
242 }
243 tty->print_cr("+++++ Calculating escape states and scalar replaceability");
244 }
245 #endif
246
247 if (non_escaped_allocs_worklist.length() == 0) {
248 _collecting = false;
249 NOT_PRODUCT(escape_state_statistics(java_objects_worklist);)
250 return false; // Nothing to do.
251 }
252 // Add final simple edges to graph.
253 while(delayed_worklist.size() > 0) {
254 Node* n = delayed_worklist.pop();
255 add_final_edges(n);
256 }
257
258 #ifdef ASSERT
259 if (VerifyConnectionGraph) {
260 // Verify that no new simple edges could be created and all
261 // local vars has edges.
262 _verify = true;
263 int ptnodes_length = ptnodes_worklist.length();
264 for (int next = 0; next < ptnodes_length; ++next) {
265 PointsToNode* ptn = ptnodes_worklist.at(next);
266 add_final_edges(ptn->ideal_node());
267 if (ptn->is_LocalVar() && ptn->edge_count() == 0) {
268 ptn->dump();
269 assert(ptn->as_LocalVar()->edge_count() > 0, "sanity");
270 }
271 }
272 _verify = false;
273 }
274 #endif
275 // Bytecode analyzer BCEscapeAnalyzer, used for Call nodes
276 // processing, calls to CI to resolve symbols (types, fields, methods)
277 // referenced in bytecode. During symbol resolution VM may throw
278 // an exception which CI cleans and converts to compilation failure.
279 if (C->failing()) {
280 NOT_PRODUCT(escape_state_statistics(java_objects_worklist);)
281 return false;
282 }
283
284 // 2. Finish Graph construction by propagating references to all
285 // java objects through graph.
286 if (!complete_connection_graph(ptnodes_worklist, non_escaped_allocs_worklist,
287 java_objects_worklist, oop_fields_worklist)) {
288 // All objects escaped or hit time or iterations limits.
289 _collecting = false;
290 NOT_PRODUCT(escape_state_statistics(java_objects_worklist);)
291 return false;
292 }
293
294 // 3. Adjust scalar_replaceable state of nonescaping objects and push
295 // scalar replaceable allocations on alloc_worklist for processing
296 // in split_unique_types().
297 GrowableArray<JavaObjectNode*> jobj_worklist;
298 int non_escaped_length = non_escaped_allocs_worklist.length();
299 bool found_nsr_alloc = false;
300 for (int next = 0; next < non_escaped_length; next++) {
301 JavaObjectNode* ptn = non_escaped_allocs_worklist.at(next);
302 bool noescape = (ptn->escape_state() == PointsToNode::NoEscape);
303 Node* n = ptn->ideal_node();
304 if (n->is_Allocate()) {
305 n->as_Allocate()->_is_non_escaping = noescape;
306 }
307 if (noescape && ptn->scalar_replaceable()) {
308 adjust_scalar_replaceable_state(ptn, reducible_merges);
309 if (ptn->scalar_replaceable()) {
310 jobj_worklist.push(ptn);
311 } else {
312 found_nsr_alloc = true;
313 }
314 }
315 }
316
317 // Propagate NSR (Not Scalar Replaceable) state.
318 if (found_nsr_alloc) {
319 find_scalar_replaceable_allocs(jobj_worklist, reducible_merges);
320 }
321
322 // alloc_worklist will be processed in reverse push order.
323 // Therefore the reducible Phis will be processed for last and that's what we
324 // want because by then the scalarizable inputs of the merge will already have
325 // an unique instance type.
326 for (uint i = 0; i < reducible_merges.size(); i++ ) {
327 Node* n = reducible_merges.at(i);
328 alloc_worklist.append(n);
329 }
330
331 for (int next = 0; next < jobj_worklist.length(); ++next) {
332 JavaObjectNode* jobj = jobj_worklist.at(next);
333 if (jobj->scalar_replaceable()) {
334 alloc_worklist.append(jobj->ideal_node());
335 }
336 }
337
338 #ifdef ASSERT
339 if (VerifyConnectionGraph) {
340 // Verify that graph is complete - no new edges could be added or needed.
341 verify_connection_graph(ptnodes_worklist, non_escaped_allocs_worklist,
342 java_objects_worklist, addp_worklist);
343 }
344 assert(C->unique() == nodes_size(), "no new ideal nodes should be added during ConnectionGraph build");
345 assert(null_obj->escape_state() == PointsToNode::NoEscape &&
346 null_obj->edge_count() == 0 &&
347 !null_obj->arraycopy_src() &&
348 !null_obj->arraycopy_dst(), "sanity");
349 #endif
350
351 _collecting = false;
352
353 } // TracePhase t3("connectionGraph")
354
355 // 4. Optimize ideal graph based on EA information.
356 bool has_non_escaping_obj = (non_escaped_allocs_worklist.length() > 0);
357 if (has_non_escaping_obj) {
358 optimize_ideal_graph(ptr_cmp_worklist, storestore_worklist);
359 }
360
361 #ifndef PRODUCT
362 if (PrintEscapeAnalysis) {
363 dump(ptnodes_worklist); // Dump ConnectionGraph
364 }
365 #endif
366
367 #ifdef ASSERT
368 if (VerifyConnectionGraph) {
369 int alloc_length = alloc_worklist.length();
370 for (int next = 0; next < alloc_length; ++next) {
371 Node* n = alloc_worklist.at(next);
372 PointsToNode* ptn = ptnode_adr(n->_idx);
373 assert(ptn->escape_state() == PointsToNode::NoEscape && ptn->scalar_replaceable(), "sanity");
374 }
375 }
376
377 if (VerifyReduceAllocationMerges) {
378 for (uint i = 0; i < reducible_merges.size(); i++ ) {
379 Node* n = reducible_merges.at(i);
380 if (!can_reduce_phi(n->as_Phi())) {
381 TraceReduceAllocationMerges = true;
382 n->dump(2);
383 n->dump(-2);
384 assert(can_reduce_phi(n->as_Phi()), "Sanity: previous reducible Phi is no longer reducible before SUT.");
385 }
386 }
387 }
388 #endif
389
390 // 5. Separate memory graph for scalar replaceable allcations.
391 bool has_scalar_replaceable_candidates = (alloc_worklist.length() > 0);
392 if (has_scalar_replaceable_candidates && EliminateAllocations) {
393 assert(C->do_aliasing(), "Aliasing should be enabled");
394 // Now use the escape information to create unique types for
395 // scalar replaceable objects.
396 split_unique_types(alloc_worklist, arraycopy_worklist, mergemem_worklist, reducible_merges);
397 if (C->failing()) {
398 NOT_PRODUCT(escape_state_statistics(java_objects_worklist);)
399 return false;
400 }
401 C->print_method(PHASE_AFTER_EA, 2);
402
403 #ifdef ASSERT
404 } else if (Verbose && (PrintEscapeAnalysis || PrintEliminateAllocations)) {
405 tty->print("=== No allocations eliminated for ");
406 C->method()->print_short_name();
407 if (!EliminateAllocations) {
408 tty->print(" since EliminateAllocations is off ===");
409 } else if(!has_scalar_replaceable_candidates) {
410 tty->print(" since there are no scalar replaceable candidates ===");
411 }
412 tty->cr();
413 #endif
414 }
415
416 // 6. Reduce allocation merges used as debug information. This is done after
417 // split_unique_types because the methods used to create SafePointScalarObject
418 // need to traverse the memory graph to find values for object fields. We also
419 // set to null the scalarized inputs of reducible Phis so that the Allocate
420 // that they point can be later scalar replaced.
421 bool delay = _igvn->delay_transform();
422 _igvn->set_delay_transform(true);
423 for (uint i = 0; i < reducible_merges.size(); i++) {
424 Node* n = reducible_merges.at(i);
425 if (n->outcnt() > 0) {
426 if (!reduce_phi_on_safepoints(n->as_Phi())) {
427 NOT_PRODUCT(escape_state_statistics(java_objects_worklist);)
428 C->record_failure(C2Compiler::retry_no_reduce_allocation_merges());
429 return false;
430 }
431
432 // Now we set the scalar replaceable inputs of ophi to null, which is
433 // the last piece that would prevent it from being scalar replaceable.
434 reset_scalar_replaceable_entries(n->as_Phi());
435 }
436 }
437 _igvn->set_delay_transform(delay);
438
439 // Annotate at safepoints if they have <= ArgEscape objects in their scope and at
440 // java calls if they pass ArgEscape objects as parameters.
441 if (has_non_escaping_obj &&
442 (C->env()->should_retain_local_variables() ||
443 C->env()->jvmti_can_get_owned_monitor_info() ||
444 C->env()->jvmti_can_walk_any_space() ||
445 DeoptimizeObjectsALot)) {
446 int sfn_length = sfn_worklist.length();
447 for (int next = 0; next < sfn_length; next++) {
448 SafePointNode* sfn = sfn_worklist.at(next);
449 sfn->set_has_ea_local_in_scope(has_ea_local_in_scope(sfn));
450 if (sfn->is_CallJava()) {
451 CallJavaNode* call = sfn->as_CallJava();
452 call->set_arg_escape(has_arg_escape(call));
453 }
454 }
455 }
456
457 NOT_PRODUCT(escape_state_statistics(java_objects_worklist);)
458 return has_non_escaping_obj;
459 }
460
461 // Check if it's profitable to reduce the Phi passed as parameter. Returns true
462 // if at least one scalar replaceable allocation participates in the merge.
463 bool ConnectionGraph::can_reduce_phi_check_inputs(PhiNode* ophi) const {
464 bool found_sr_allocate = false;
465
466 for (uint i = 1; i < ophi->req(); i++) {
467 JavaObjectNode* ptn = unique_java_object(ophi->in(i));
468 if (ptn != nullptr && ptn->scalar_replaceable()) {
469 AllocateNode* alloc = ptn->ideal_node()->as_Allocate();
470
471 // Don't handle arrays.
472 if (alloc->Opcode() != Op_Allocate) {
473 assert(alloc->Opcode() == Op_AllocateArray, "Unexpected type of allocation.");
474 continue;
475 }
476
477 if (PhaseMacroExpand::can_eliminate_allocation(_igvn, alloc, nullptr)) {
478 found_sr_allocate = true;
479 } else {
480 NOT_PRODUCT(if (TraceReduceAllocationMerges) tty->print_cr("%dth input of Phi %d is SR but can't be eliminated.", i, ophi->_idx);)
481 ptn->set_scalar_replaceable(false);
482 }
483 }
484 }
485
486 NOT_PRODUCT(if (TraceReduceAllocationMerges && !found_sr_allocate) tty->print_cr("Can NOT reduce Phi %d on invocation %d. No SR Allocate as input.", ophi->_idx, _invocation);)
487 return found_sr_allocate;
488 }
489
490 // We can reduce the Cmp if it's a comparison between the Phi and a constant.
491 // I require the 'other' input to be a constant so that I can move the Cmp
492 // around safely.
493 bool ConnectionGraph::can_reduce_cmp(Node* n, Node* cmp) const {
494 assert(cmp->Opcode() == Op_CmpP || cmp->Opcode() == Op_CmpN, "not expected node: %s", cmp->Name());
495 Node* left = cmp->in(1);
496 Node* right = cmp->in(2);
497
498 return (left == n || right == n) &&
499 (left->is_Con() || right->is_Con()) &&
500 cmp->outcnt() == 1;
501 }
502
503 // We are going to check if any of the SafePointScalarMerge entries
504 // in the SafePoint reference the Phi that we are checking.
505 bool ConnectionGraph::has_been_reduced(PhiNode* n, SafePointNode* sfpt) const {
506 JVMState *jvms = sfpt->jvms();
507
508 for (uint i = jvms->debug_start(); i < jvms->debug_end(); i++) {
509 Node* sfpt_in = sfpt->in(i);
510 if (sfpt_in->is_SafePointScalarMerge()) {
511 SafePointScalarMergeNode* smerge = sfpt_in->as_SafePointScalarMerge();
512 Node* nsr_ptr = sfpt->in(smerge->merge_pointer_idx(jvms));
513 if (nsr_ptr == n) {
514 return true;
515 }
516 }
517 }
518
519 return false;
520 }
521
522 // Check if we are able to untangle the merge. The following patterns are
523 // supported:
524 // - Phi -> SafePoints
525 // - Phi -> CmpP/N
526 // - Phi -> AddP -> Load
527 // - Phi -> CastPP -> SafePoints
528 // - Phi -> CastPP -> AddP -> Load
529 bool ConnectionGraph::can_reduce_check_users(Node* n, uint nesting) const {
530 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
531 Node* use = n->fast_out(i);
532
533 if (use->is_SafePoint()) {
534 if (use->is_Call() && use->as_Call()->has_non_debug_use(n)) {
535 NOT_PRODUCT(if (TraceReduceAllocationMerges) tty->print_cr("Can NOT reduce Phi %d on invocation %d. Call has non_debug_use().", n->_idx, _invocation);)
536 return false;
537 } else if (has_been_reduced(n->is_Phi() ? n->as_Phi() : n->as_CastPP()->in(1)->as_Phi(), use->as_SafePoint())) {
538 NOT_PRODUCT(if (TraceReduceAllocationMerges) tty->print_cr("Can NOT reduce Phi %d on invocation %d. It has already been reduced.", n->_idx, _invocation);)
539 return false;
540 }
541 } else if (use->is_AddP()) {
542 Node* addp = use;
543 for (DUIterator_Fast jmax, j = addp->fast_outs(jmax); j < jmax; j++) {
544 Node* use_use = addp->fast_out(j);
545 const Type* load_type = _igvn->type(use_use);
546
547 if (!use_use->is_Load() || !use_use->as_Load()->can_split_through_phi_base(_igvn)) {
548 NOT_PRODUCT(if (TraceReduceAllocationMerges) tty->print_cr("Can NOT reduce Phi %d on invocation %d. AddP user isn't a [splittable] Load(): %s", n->_idx, _invocation, use_use->Name());)
549 return false;
550 } else if (load_type->isa_narrowklass() || load_type->isa_klassptr()) {
551 NOT_PRODUCT(if (TraceReduceAllocationMerges) tty->print_cr("Can NOT reduce Phi %d on invocation %d. [Narrow] Klass Load: %s", n->_idx, _invocation, use_use->Name());)
552 return false;
553 }
554 }
555 } else if (nesting > 0) {
556 NOT_PRODUCT(if (TraceReduceAllocationMerges) tty->print_cr("Can NOT reduce Phi %d on invocation %d. Unsupported user %s at nesting level %d.", n->_idx, _invocation, use->Name(), nesting);)
557 return false;
558 } else if (use->is_CastPP()) {
559 const Type* cast_t = _igvn->type(use);
560 if (cast_t == nullptr || cast_t->make_ptr()->isa_instptr() == nullptr) {
561 #ifndef PRODUCT
562 if (TraceReduceAllocationMerges) {
563 tty->print_cr("Can NOT reduce Phi %d on invocation %d. CastPP is not to an instance.", n->_idx, _invocation);
564 use->dump();
565 }
566 #endif
567 return false;
568 }
569
570 bool is_trivial_control = use->in(0) == nullptr || use->in(0) == n->in(0);
571 if (!is_trivial_control) {
572 // If it's not a trivial control then we check if we can reduce the
573 // CmpP/N used by the If controlling the cast.
574 if (use->in(0)->is_IfTrue() || use->in(0)->is_IfFalse()) {
575 Node* iff = use->in(0)->in(0);
576 // We may have an OpaqueNotNull node between If and Bool nodes. But we could also have a sub class of IfNode,
577 // for example, an OuterStripMinedLoopEnd or a Parse Predicate. Bail out in all these cases.
578 bool can_reduce = (iff->Opcode() == Op_If) && iff->in(1)->is_Bool() && iff->in(1)->in(1)->is_Cmp();
579 if (can_reduce) {
580 Node* iff_cmp = iff->in(1)->in(1);
581 int opc = iff_cmp->Opcode();
582 can_reduce = (opc == Op_CmpP || opc == Op_CmpN) && can_reduce_cmp(n, iff_cmp);
583 }
584 if (!can_reduce) {
585 #ifndef PRODUCT
586 if (TraceReduceAllocationMerges) {
587 tty->print_cr("Can NOT reduce Phi %d on invocation %d. CastPP %d doesn't have simple control.", n->_idx, _invocation, use->_idx);
588 n->dump(5);
589 }
590 #endif
591 return false;
592 }
593 }
594 }
595
596 if (!can_reduce_check_users(use, nesting+1)) {
597 return false;
598 }
599 } else if (use->Opcode() == Op_CmpP || use->Opcode() == Op_CmpN) {
600 if (!can_reduce_cmp(n, use)) {
601 NOT_PRODUCT(if (TraceReduceAllocationMerges) tty->print_cr("Can NOT reduce Phi %d on invocation %d. CmpP/N %d isn't reducible.", n->_idx, _invocation, use->_idx);)
602 return false;
603 }
604 } else {
605 NOT_PRODUCT(if (TraceReduceAllocationMerges) tty->print_cr("Can NOT reduce Phi %d on invocation %d. One of the uses is: %d %s", n->_idx, _invocation, use->_idx, use->Name());)
606 return false;
607 }
608 }
609
610 return true;
611 }
612
613 // Returns true if: 1) It's profitable to reduce the merge, and 2) The Phi is
614 // only used in some certain code shapes. Check comments in
615 // 'can_reduce_phi_inputs' and 'can_reduce_phi_users' for more
616 // details.
617 bool ConnectionGraph::can_reduce_phi(PhiNode* ophi) const {
618 // If there was an error attempting to reduce allocation merges for this
619 // method we might have disabled the compilation and be retrying with RAM
620 // disabled.
621 if (!_compile->do_reduce_allocation_merges() || ophi->region()->Opcode() != Op_Region) {
622 return false;
623 }
624
625 const Type* phi_t = _igvn->type(ophi);
626 if (phi_t == nullptr ||
627 phi_t->make_ptr() == nullptr ||
628 phi_t->make_ptr()->isa_aryptr() != nullptr) {
629 return false;
630 }
631
632 if (!can_reduce_phi_check_inputs(ophi) || !can_reduce_check_users(ophi, /* nesting: */ 0)) {
633 return false;
634 }
635
636 NOT_PRODUCT(if (TraceReduceAllocationMerges) { tty->print_cr("Can reduce Phi %d during invocation %d: ", ophi->_idx, _invocation); })
637 return true;
638 }
639
640 // This method will return a CmpP/N that we need to use on the If controlling a
641 // CastPP after it was split. This method is only called on bases that are
642 // nullable therefore we always need a controlling if for the splitted CastPP.
643 //
644 // 'curr_ctrl' is the control of the CastPP that we want to split through phi.
645 // If the CastPP currently doesn't have a control then the CmpP/N will be
646 // against the null constant, otherwise it will be against the constant input of
647 // the existing CmpP/N. It's guaranteed that there will be a CmpP/N in the later
648 // case because we have constraints on it and because the CastPP has a control
649 // input.
650 Node* ConnectionGraph::specialize_cmp(Node* base, Node* curr_ctrl) {
651 const Type* t = base->bottom_type();
652 Node* con = nullptr;
653
654 if (curr_ctrl == nullptr || curr_ctrl->is_Region()) {
655 con = _igvn->zerocon(t->basic_type());
656 } else {
657 // can_reduce_check_users() verified graph: true/false -> if -> bool -> cmp
658 assert(curr_ctrl->in(0)->Opcode() == Op_If, "unexpected node %s", curr_ctrl->in(0)->Name());
659 Node* bol = curr_ctrl->in(0)->in(1);
660 assert(bol->is_Bool(), "unexpected node %s", bol->Name());
661 Node* curr_cmp = bol->in(1);
662 assert(curr_cmp->Opcode() == Op_CmpP || curr_cmp->Opcode() == Op_CmpN, "unexpected node %s", curr_cmp->Name());
663 con = curr_cmp->in(1)->is_Con() ? curr_cmp->in(1) : curr_cmp->in(2);
664 }
665
666 return CmpNode::make(base, con, t->basic_type());
667 }
668
669 // This method 'specializes' the CastPP passed as parameter to the base passed
670 // as parameter. Note that the existing CastPP input is a Phi. "Specialize"
671 // means that the CastPP now will be specific for a given base instead of a Phi.
672 // An If-Then-Else-Region block is inserted to control the CastPP. The control
673 // of the CastPP is a copy of the current one (if there is one) or a check
674 // against null.
675 //
676 // Before:
677 //
678 // C1 C2 ... Cn
679 // \ | /
680 // \ | /
681 // \ | /
682 // \ | /
683 // \ | /
684 // \ | /
685 // \|/
686 // Region B1 B2 ... Bn
687 // | \ | /
688 // | \ | /
689 // | \ | /
690 // | \ | /
691 // | \ | /
692 // | \ | /
693 // ---------------> Phi
694 // |
695 // X |
696 // | |
697 // | |
698 // ------> CastPP
699 //
700 // After (only partial illustration; base = B2, current_control = C2):
701 //
702 // C2
703 // |
704 // If
705 // / \
706 // / \
707 // T F
708 // /\ /
709 // / \ /
710 // / \ /
711 // C1 CastPP Reg Cn
712 // | | |
713 // | | |
714 // | | |
715 // -------------- | ----------
716 // | | |
717 // Region
718 //
719 Node* ConnectionGraph::specialize_castpp(Node* castpp, Node* base, Node* current_control) {
720 Node* control_successor = current_control->unique_ctrl_out();
721 Node* cmp = _igvn->transform(specialize_cmp(base, castpp->in(0)));
722 Node* bol = _igvn->transform(new BoolNode(cmp, BoolTest::ne));
723 IfNode* if_ne = _igvn->transform(new IfNode(current_control, bol, PROB_MIN, COUNT_UNKNOWN))->as_If();
724 Node* not_eq_control = _igvn->transform(new IfTrueNode(if_ne));
725 Node* yes_eq_control = _igvn->transform(new IfFalseNode(if_ne));
726 Node* end_region = _igvn->transform(new RegionNode(3));
727
728 // Insert the new if-else-region block into the graph
729 end_region->set_req(1, not_eq_control);
730 end_region->set_req(2, yes_eq_control);
731 control_successor->replace_edge(current_control, end_region, _igvn);
732
733 _igvn->_worklist.push(current_control);
734 _igvn->_worklist.push(control_successor);
735
736 return _igvn->transform(ConstraintCastNode::make_cast_for_type(not_eq_control, base, _igvn->type(castpp), ConstraintCastNode::UnconditionalDependency, nullptr));
737 }
738
739 Node* ConnectionGraph::split_castpp_load_through_phi(Node* curr_addp, Node* curr_load, Node* region, GrowableArray<Node*>* bases_for_loads, GrowableArray<Node *> &alloc_worklist) {
740 const Type* load_type = _igvn->type(curr_load);
741 Node* nsr_value = _igvn->zerocon(load_type->basic_type());
742 Node* memory = curr_load->in(MemNode::Memory);
743
744 // The data_phi merging the loads needs to be nullable if
745 // we are loading pointers.
746 if (load_type->make_ptr() != nullptr) {
747 if (load_type->isa_narrowoop()) {
748 load_type = load_type->meet(TypeNarrowOop::NULL_PTR);
749 } else if (load_type->isa_ptr()) {
750 load_type = load_type->meet(TypePtr::NULL_PTR);
751 } else {
752 assert(false, "Unexpected load ptr type.");
753 }
754 }
755
756 Node* data_phi = PhiNode::make(region, nsr_value, load_type);
757
758 for (int i = 1; i < bases_for_loads->length(); i++) {
759 Node* base = bases_for_loads->at(i);
760 Node* cmp_region = nullptr;
761 if (base != nullptr) {
762 if (base->is_CFG()) { // means that we added a CastPP as child of this CFG node
763 cmp_region = base->unique_ctrl_out_or_null();
764 assert(cmp_region != nullptr, "There should be.");
765 base = base->find_out_with(Op_CastPP);
766 }
767
768 Node* addr = _igvn->transform(new AddPNode(base, base, curr_addp->in(AddPNode::Offset)));
769 Node* mem = (memory->is_Phi() && (memory->in(0) == region)) ? memory->in(i) : memory;
770 Node* load = curr_load->clone();
771 load->set_req(0, nullptr);
772 load->set_req(1, mem);
773 load->set_req(2, addr);
774
775 if (cmp_region != nullptr) { // see comment on previous if
776 Node* intermediate_phi = PhiNode::make(cmp_region, nsr_value, load_type);
777 intermediate_phi->set_req(1, _igvn->transform(load));
778 load = intermediate_phi;
779 }
780
781 data_phi->set_req(i, _igvn->transform(load));
782 } else {
783 // Just use the default, which is already in phi
784 }
785 }
786
787 // Takes care of updating CG and split_unique_types worklists due
788 // to cloned AddP->Load.
789 updates_after_load_split(data_phi, curr_load, alloc_worklist);
790
791 return _igvn->transform(data_phi);
792 }
793
794 // This method only reduces CastPP fields loads; SafePoints are handled
795 // separately. The idea here is basically to clone the CastPP and place copies
796 // on each input of the Phi, including non-scalar replaceable inputs.
797 // Experimentation shows that the resulting IR graph is simpler that way than if
798 // we just split the cast through scalar-replaceable inputs.
799 //
800 // The reduction process requires that CastPP's control be one of:
801 // 1) no control,
802 // 2) the same region as Ophi, or
803 // 3) an IfTrue/IfFalse coming from an CmpP/N between Ophi and a constant.
804 //
805 // After splitting the CastPP we'll put it under an If-Then-Else-Region control
806 // flow. If the CastPP originally had an IfTrue/False control input then we'll
807 // use a similar CmpP/N to control the new If-Then-Else-Region. Otherwise, we'll
808 // juse use a CmpP/N against the null constant.
809 //
810 // The If-Then-Else-Region isn't always needed. For instance, if input to
811 // splitted cast was not nullable (or if it was the null constant) then we don't
812 // need (shouldn't) use a CastPP at all.
813 //
814 // After the casts are splitted we'll split the AddP->Loads through the Phi and
815 // connect them to the just split CastPPs.
816 //
817 // Before (CastPP control is same as Phi):
818 //
819 // Region Allocate Null Call
820 // | \ | /
821 // | \ | /
822 // | \ | /
823 // | \ | /
824 // | \ | /
825 // | \ | /
826 // ------------------> Phi # Oop Phi
827 // | |
828 // | |
829 // | |
830 // | |
831 // ----------------> CastPP
832 // |
833 // AddP
834 // |
835 // Load
836 //
837 // After (Very much simplified):
838 //
839 // Call Null
840 // \ /
841 // CmpP
842 // |
843 // Bool#NE
844 // |
845 // If
846 // / \
847 // T F
848 // / \ /
849 // / R
850 // CastPP |
851 // | |
852 // AddP |
853 // | |
854 // Load |
855 // \ | 0
856 // Allocate \ | /
857 // \ \ | /
858 // AddP Phi
859 // \ /
860 // Load /
861 // \ 0 /
862 // \ | /
863 // \|/
864 // Phi # "Field" Phi
865 //
866 void ConnectionGraph::reduce_phi_on_castpp_field_load(Node* curr_castpp, GrowableArray<Node *> &alloc_worklist, GrowableArray<Node *> &memnode_worklist) {
867 Node* ophi = curr_castpp->in(1);
868 assert(ophi->is_Phi(), "Expected this to be a Phi node.");
869
870 // Identify which base should be used for AddP->Load later when spliting the
871 // CastPP->Loads through ophi. Three kind of values may be stored in this
872 // array, depending on the nullability status of the corresponding input in
873 // ophi.
874 //
875 // - nullptr: Meaning that the base is actually the null constant and therefore
876 // we won't try to load from it.
877 //
878 // - CFG Node: Meaning that the base is a CastPP that was specialized for
879 // this input of Ophi. I.e., we added an If->Then->Else-Region
880 // that will 'activate' the CastPp only when the input is not Null.
881 //
882 // - Other Node: Meaning that the base is not nullable and therefore we'll try
883 // to load directly from it.
884 GrowableArray<Node*> bases_for_loads(ophi->req(), ophi->req(), nullptr);
885
886 for (uint i = 1; i < ophi->req(); i++) {
887 Node* base = ophi->in(i);
888 const Type* base_t = _igvn->type(base);
889
890 if (base_t->maybe_null()) {
891 if (base->is_Con()) {
892 // Nothing todo as bases_for_loads[i] is already null
893 } else {
894 Node* new_castpp = specialize_castpp(curr_castpp, base, ophi->in(0)->in(i));
895 bases_for_loads.at_put(i, new_castpp->in(0)); // Use the ctrl of the new node just as a flag
896 }
897 } else {
898 bases_for_loads.at_put(i, base);
899 }
900 }
901
902 // Now let's split the CastPP->Loads through the Phi
903 for (int i = curr_castpp->outcnt()-1; i >= 0;) {
904 Node* use = curr_castpp->raw_out(i);
905 if (use->is_AddP()) {
906 for (int j = use->outcnt()-1; j >= 0;) {
907 Node* use_use = use->raw_out(j);
908 assert(use_use->is_Load(), "Expected this to be a Load node.");
909
910 // We can't make an unconditional load from a nullable input. The
911 // 'split_castpp_load_through_phi` method will add an
912 // 'If-Then-Else-Region` around nullable bases and only load from them
913 // when the input is not null.
914 Node* phi = split_castpp_load_through_phi(use, use_use, ophi->in(0), &bases_for_loads, alloc_worklist);
915 _igvn->replace_node(use_use, phi);
916
917 --j;
918 j = MIN2(j, (int)use->outcnt()-1);
919 }
920
921 _igvn->remove_dead_node(use);
922 }
923 --i;
924 i = MIN2(i, (int)curr_castpp->outcnt()-1);
925 }
926 }
927
928 // This method split a given CmpP/N through the Phi used in one of its inputs.
929 // As a result we convert a comparison with a pointer to a comparison with an
930 // integer.
931 // The only requirement is that one of the inputs of the CmpP/N must be a Phi
932 // while the other must be a constant.
933 // The splitting process is basically just cloning the CmpP/N above the input
934 // Phi. However, some (most) of the cloned CmpP/Ns won't be requred because we
935 // can prove at compile time the result of the comparison.
936 //
937 // Before:
938 //
939 // in1 in2 ... inN
940 // \ | /
941 // \ | /
942 // \ | /
943 // \ | /
944 // \ | /
945 // \ | /
946 // Phi
947 // | Other
948 // | /
949 // | /
950 // | /
951 // CmpP/N
952 //
953 // After:
954 //
955 // in1 Other in2 Other inN Other
956 // | | | | | |
957 // \ | | | | |
958 // \ / | / | /
959 // CmpP/N CmpP/N CmpP/N
960 // Bool Bool Bool
961 // \ | /
962 // \ | /
963 // \ | /
964 // \ | /
965 // \ | /
966 // \ | /
967 // \ | /
968 // \ | /
969 // Phi
970 // |
971 // | Zero
972 // | /
973 // | /
974 // | /
975 // CmpI
976 //
977 //
978 void ConnectionGraph::reduce_phi_on_cmp(Node* cmp) {
979 Node* ophi = cmp->in(1)->is_Con() ? cmp->in(2) : cmp->in(1);
980 assert(ophi->is_Phi(), "Expected this to be a Phi node.");
981
982 Node* other = cmp->in(1)->is_Con() ? cmp->in(1) : cmp->in(2);
983 Node* zero = _igvn->intcon(0);
984 Node* one = _igvn->intcon(1);
985 BoolTest::mask mask = cmp->unique_out()->as_Bool()->_test._test;
986
987 // This Phi will merge the result of the Cmps split through the Phi
988 Node* res_phi = PhiNode::make(ophi->in(0), zero, TypeInt::INT);
989
990 for (uint i=1; i<ophi->req(); i++) {
991 Node* ophi_input = ophi->in(i);
992 Node* res_phi_input = nullptr;
993
994 const TypeInt* tcmp = optimize_ptr_compare(ophi_input, other);
995 if (tcmp->singleton()) {
996 if ((mask == BoolTest::mask::eq && tcmp == TypeInt::CC_EQ) ||
997 (mask == BoolTest::mask::ne && tcmp == TypeInt::CC_GT)) {
998 res_phi_input = one;
999 } else {
1000 res_phi_input = zero;
1001 }
1002 } else {
1003 Node* ncmp = _igvn->transform(cmp->clone());
1004 ncmp->set_req(1, ophi_input);
1005 ncmp->set_req(2, other);
1006 Node* bol = _igvn->transform(new BoolNode(ncmp, mask));
1007 res_phi_input = bol->as_Bool()->as_int_value(_igvn);
1008 }
1009
1010 res_phi->set_req(i, res_phi_input);
1011 }
1012
1013 // This CMP always compares whether the output of "res_phi" is TRUE as far as the "mask".
1014 Node* new_cmp = _igvn->transform(new CmpINode(_igvn->transform(res_phi), (mask == BoolTest::mask::eq) ? one : zero));
1015 _igvn->replace_node(cmp, new_cmp);
1016 }
1017
1018 // Push the newly created AddP on alloc_worklist and patch
1019 // the connection graph. Note that the changes in the CG below
1020 // won't affect the ES of objects since the new nodes have the
1021 // same status as the old ones.
1022 void ConnectionGraph::updates_after_load_split(Node* data_phi, Node* previous_load, GrowableArray<Node *> &alloc_worklist) {
1023 assert(data_phi != nullptr, "Output of split_through_phi is null.");
1024 assert(data_phi != previous_load, "Output of split_through_phi is same as input.");
1025 assert(data_phi->is_Phi(), "Output of split_through_phi isn't a Phi.");
1026
1027 if (data_phi == nullptr || !data_phi->is_Phi()) {
1028 // Make this a retry?
1029 return ;
1030 }
1031
1032 Node* previous_addp = previous_load->in(MemNode::Address);
1033 FieldNode* fn = ptnode_adr(previous_addp->_idx)->as_Field();
1034 for (uint i = 1; i < data_phi->req(); i++) {
1035 Node* new_load = data_phi->in(i);
1036
1037 if (new_load->is_Phi()) {
1038 // new_load is currently the "intermediate_phi" from an specialized
1039 // CastPP.
1040 new_load = new_load->in(1);
1041 }
1042
1043 // "new_load" might actually be a constant, parameter, etc.
1044 if (new_load->is_Load()) {
1045 Node* new_addp = new_load->in(MemNode::Address);
1046 Node* base = get_addp_base(new_addp);
1047
1048 // The base might not be something that we can create an unique
1049 // type for. If that's the case we are done with that input.
1050 PointsToNode* jobj_ptn = unique_java_object(base);
1051 if (jobj_ptn == nullptr || !jobj_ptn->scalar_replaceable()) {
1052 continue;
1053 }
1054
1055 // Push to alloc_worklist since the base has an unique_type
1056 alloc_worklist.append_if_missing(new_addp);
1057
1058 // Now let's add the node to the connection graph
1059 _nodes.at_grow(new_addp->_idx, nullptr);
1060 add_field(new_addp, fn->escape_state(), fn->offset());
1061 add_base(ptnode_adr(new_addp->_idx)->as_Field(), ptnode_adr(base->_idx));
1062
1063 // If the load doesn't load an object then it won't be
1064 // part of the connection graph
1065 PointsToNode* curr_load_ptn = ptnode_adr(previous_load->_idx);
1066 if (curr_load_ptn != nullptr) {
1067 _nodes.at_grow(new_load->_idx, nullptr);
1068 add_local_var(new_load, curr_load_ptn->escape_state());
1069 add_edge(ptnode_adr(new_load->_idx), ptnode_adr(new_addp->_idx)->as_Field());
1070 }
1071 }
1072 }
1073 }
1074
1075 void ConnectionGraph::reduce_phi_on_field_access(Node* previous_addp, GrowableArray<Node *> &alloc_worklist) {
1076 // We'll pass this to 'split_through_phi' so that it'll do the split even
1077 // though the load doesn't have an unique instance type.
1078 bool ignore_missing_instance_id = true;
1079
1080 // All AddPs are present in the connection graph
1081 FieldNode* fn = ptnode_adr(previous_addp->_idx)->as_Field();
1082
1083 // Iterate over AddP looking for a Load
1084 for (int k = previous_addp->outcnt()-1; k >= 0;) {
1085 Node* previous_load = previous_addp->raw_out(k);
1086 if (previous_load->is_Load()) {
1087 Node* data_phi = previous_load->as_Load()->split_through_phi(_igvn, ignore_missing_instance_id);
1088
1089 // Takes care of updating CG and split_unique_types worklists due to cloned
1090 // AddP->Load.
1091 updates_after_load_split(data_phi, previous_load, alloc_worklist);
1092
1093 _igvn->replace_node(previous_load, data_phi);
1094 }
1095 --k;
1096 k = MIN2(k, (int)previous_addp->outcnt()-1);
1097 }
1098
1099 // Remove the old AddP from the processing list because it's dead now
1100 assert(previous_addp->outcnt() == 0, "AddP should be dead now.");
1101 alloc_worklist.remove_if_existing(previous_addp);
1102 }
1103
1104 // Create a 'selector' Phi based on the inputs of 'ophi'. If index 'i' of the
1105 // selector is:
1106 // -> a '-1' constant, the i'th input of the original Phi is NSR.
1107 // -> a 'x' constant >=0, the i'th input of of original Phi will be SR and
1108 // the info about the scalarized object will be at index x of ObjectMergeValue::possible_objects
1109 PhiNode* ConnectionGraph::create_selector(PhiNode* ophi) const {
1110 Node* minus_one = _igvn->register_new_node_with_optimizer(ConINode::make(-1));
1111 Node* selector = _igvn->register_new_node_with_optimizer(PhiNode::make(ophi->region(), minus_one, TypeInt::INT));
1112 uint number_of_sr_objects = 0;
1113 for (uint i = 1; i < ophi->req(); i++) {
1114 Node* base = ophi->in(i);
1115 JavaObjectNode* ptn = unique_java_object(base);
1116
1117 if (ptn != nullptr && ptn->scalar_replaceable()) {
1118 Node* sr_obj_idx = _igvn->register_new_node_with_optimizer(ConINode::make(number_of_sr_objects));
1119 selector->set_req(i, sr_obj_idx);
1120 number_of_sr_objects++;
1121 }
1122 }
1123
1124 return selector->as_Phi();
1125 }
1126
1127 // Returns true if the AddP node 'n' has at least one base that is a reducible
1128 // merge. If the base is a CastPP/CheckCastPP then the input of the cast is
1129 // checked instead.
1130 bool ConnectionGraph::has_reducible_merge_base(AddPNode* n, Unique_Node_List &reducible_merges) {
1131 PointsToNode* ptn = ptnode_adr(n->_idx);
1132 if (ptn == nullptr || !ptn->is_Field() || ptn->as_Field()->base_count() < 2) {
1133 return false;
1134 }
1135
1136 for (BaseIterator i(ptn->as_Field()); i.has_next(); i.next()) {
1137 Node* base = i.get()->ideal_node();
1138
1139 if (reducible_merges.member(base)) {
1140 return true;
1141 }
1142
1143 if (base->is_CastPP() || base->is_CheckCastPP()) {
1144 base = base->in(1);
1145 if (reducible_merges.member(base)) {
1146 return true;
1147 }
1148 }
1149 }
1150
1151 return false;
1152 }
1153
1154 // This method will call its helper method to reduce SafePoint nodes that use
1155 // 'ophi' or a casted version of 'ophi'. All SafePoint nodes using the same
1156 // "version" of Phi use the same debug information (regarding the Phi).
1157 // Therefore, I collect all safepoints and patch them all at once.
1158 //
1159 // The safepoints using the Phi node have to be processed before safepoints of
1160 // CastPP nodes. The reason is, when reducing a CastPP we add a reference (the
1161 // NSR merge pointer) to the input of the CastPP (i.e., the Phi) in the
1162 // safepoint. If we process CastPP's safepoints before Phi's safepoints the
1163 // algorithm that process Phi's safepoints will think that the added Phi
1164 // reference is a regular reference.
1165 bool ConnectionGraph::reduce_phi_on_safepoints(PhiNode* ophi) {
1166 PhiNode* selector = create_selector(ophi);
1167 Unique_Node_List safepoints;
1168 Unique_Node_List casts;
1169
1170 // Just collect the users of the Phis for later processing
1171 // in the needed order.
1172 for (uint i = 0; i < ophi->outcnt(); i++) {
1173 Node* use = ophi->raw_out(i);
1174 if (use->is_SafePoint()) {
1175 safepoints.push(use);
1176 } else if (use->is_CastPP()) {
1177 casts.push(use);
1178 } else {
1179 assert(use->outcnt() == 0, "Only CastPP & SafePoint users should be left.");
1180 }
1181 }
1182
1183 // Need to process safepoints using the Phi first
1184 if (!reduce_phi_on_safepoints_helper(ophi, nullptr, selector, safepoints)) {
1185 return false;
1186 }
1187
1188 // Now process CastPP->safepoints
1189 for (uint i = 0; i < casts.size(); i++) {
1190 Node* cast = casts.at(i);
1191 Unique_Node_List cast_sfpts;
1192
1193 for (DUIterator_Fast jmax, j = cast->fast_outs(jmax); j < jmax; j++) {
1194 Node* use_use = cast->fast_out(j);
1195 if (use_use->is_SafePoint()) {
1196 cast_sfpts.push(use_use);
1197 } else {
1198 assert(use_use->outcnt() == 0, "Only SafePoint users should be left.");
1199 }
1200 }
1201
1202 if (!reduce_phi_on_safepoints_helper(ophi, cast, selector, cast_sfpts)) {
1203 return false;
1204 }
1205 }
1206
1207 return true;
1208 }
1209
1210 // This method will create a SafePointScalarMERGEnode for each SafePoint in
1211 // 'safepoints'. It then will iterate on the inputs of 'ophi' and create a
1212 // SafePointScalarObjectNode for each scalar replaceable input. Each
1213 // SafePointScalarMergeNode may describe multiple scalar replaced objects -
1214 // check detailed description in SafePointScalarMergeNode class header.
1215 bool ConnectionGraph::reduce_phi_on_safepoints_helper(Node* ophi, Node* cast, Node* selector, Unique_Node_List& safepoints) {
1216 PhaseMacroExpand mexp(*_igvn);
1217 Node* original_sfpt_parent = cast != nullptr ? cast : ophi;
1218 const TypeOopPtr* merge_t = _igvn->type(original_sfpt_parent)->make_oopptr();
1219
1220 Node* nsr_merge_pointer = ophi;
1221 if (cast != nullptr) {
1222 const Type* new_t = merge_t->meet(TypePtr::NULL_PTR);
1223 nsr_merge_pointer = _igvn->transform(ConstraintCastNode::make_cast_for_type(cast->in(0), cast->in(1), new_t, ConstraintCastNode::RegularDependency, nullptr));
1224 }
1225
1226 for (uint spi = 0; spi < safepoints.size(); spi++) {
1227 SafePointNode* sfpt = safepoints.at(spi)->as_SafePoint();
1228 JVMState *jvms = sfpt->jvms();
1229 uint merge_idx = (sfpt->req() - jvms->scloff());
1230 int debug_start = jvms->debug_start();
1231
1232 SafePointScalarMergeNode* smerge = new SafePointScalarMergeNode(merge_t, merge_idx);
1233 smerge->init_req(0, _compile->root());
1234 _igvn->register_new_node_with_optimizer(smerge);
1235
1236 // The next two inputs are:
1237 // (1) A copy of the original pointer to NSR objects.
1238 // (2) A selector, used to decide if we need to rematerialize an object
1239 // or use the pointer to a NSR object.
1240 // See more details of these fields in the declaration of SafePointScalarMergeNode
1241 sfpt->add_req(nsr_merge_pointer);
1242 sfpt->add_req(selector);
1243
1244 for (uint i = 1; i < ophi->req(); i++) {
1245 Node* base = ophi->in(i);
1246 JavaObjectNode* ptn = unique_java_object(base);
1247
1248 // If the base is not scalar replaceable we don't need to register information about
1249 // it at this time.
1250 if (ptn == nullptr || !ptn->scalar_replaceable()) {
1251 continue;
1252 }
1253
1254 AllocateNode* alloc = ptn->ideal_node()->as_Allocate();
1255 SafePointScalarObjectNode* sobj = mexp.create_scalarized_object_description(alloc, sfpt);
1256 if (sobj == nullptr) {
1257 return false;
1258 }
1259
1260 // Now make a pass over the debug information replacing any references
1261 // to the allocated object with "sobj"
1262 Node* ccpp = alloc->result_cast();
1263 sfpt->replace_edges_in_range(ccpp, sobj, debug_start, jvms->debug_end(), _igvn);
1264
1265 // Register the scalarized object as a candidate for reallocation
1266 smerge->add_req(sobj);
1267 }
1268
1269 // Replaces debug information references to "original_sfpt_parent" in "sfpt" with references to "smerge"
1270 sfpt->replace_edges_in_range(original_sfpt_parent, smerge, debug_start, jvms->debug_end(), _igvn);
1271
1272 // The call to 'replace_edges_in_range' above might have removed the
1273 // reference to ophi that we need at _merge_pointer_idx. The line below make
1274 // sure the reference is maintained.
1275 sfpt->set_req(smerge->merge_pointer_idx(jvms), nsr_merge_pointer);
1276 _igvn->_worklist.push(sfpt);
1277 }
1278
1279 return true;
1280 }
1281
1282 void ConnectionGraph::reduce_phi(PhiNode* ophi, GrowableArray<Node *> &alloc_worklist, GrowableArray<Node *> &memnode_worklist) {
1283 bool delay = _igvn->delay_transform();
1284 _igvn->set_delay_transform(true);
1285 _igvn->hash_delete(ophi);
1286
1287 // Copying all users first because some will be removed and others won't.
1288 // Ophi also may acquire some new users as part of Cast reduction.
1289 // CastPPs also need to be processed before CmpPs.
1290 Unique_Node_List castpps;
1291 Unique_Node_List others;
1292 for (DUIterator_Fast imax, i = ophi->fast_outs(imax); i < imax; i++) {
1293 Node* use = ophi->fast_out(i);
1294
1295 if (use->is_CastPP()) {
1296 castpps.push(use);
1297 } else if (use->is_AddP() || use->is_Cmp()) {
1298 others.push(use);
1299 } else if (use->is_SafePoint()) {
1300 // processed later
1301 } else {
1302 assert(use->is_SafePoint(), "Unexpected user of reducible Phi %d -> %d:%s:%d", ophi->_idx, use->_idx, use->Name(), use->outcnt());
1303 }
1304 }
1305
1306 // CastPPs need to be processed before Cmps because during the process of
1307 // splitting CastPPs we make reference to the inputs of the Cmp that is used
1308 // by the If controlling the CastPP.
1309 for (uint i = 0; i < castpps.size(); i++) {
1310 reduce_phi_on_castpp_field_load(castpps.at(i), alloc_worklist, memnode_worklist);
1311 }
1312
1313 for (uint i = 0; i < others.size(); i++) {
1314 Node* use = others.at(i);
1315
1316 if (use->is_AddP()) {
1317 reduce_phi_on_field_access(use, alloc_worklist);
1318 } else if(use->is_Cmp()) {
1319 reduce_phi_on_cmp(use);
1320 }
1321 }
1322
1323 _igvn->set_delay_transform(delay);
1324 }
1325
1326 void ConnectionGraph::reset_scalar_replaceable_entries(PhiNode* ophi) {
1327 Node* null_ptr = _igvn->makecon(TypePtr::NULL_PTR);
1328 const TypeOopPtr* merge_t = _igvn->type(ophi)->make_oopptr();
1329 const Type* new_t = merge_t->meet(TypePtr::NULL_PTR);
1330 Node* new_phi = _igvn->register_new_node_with_optimizer(PhiNode::make(ophi->region(), null_ptr, new_t));
1331
1332 for (uint i = 1; i < ophi->req(); i++) {
1333 Node* base = ophi->in(i);
1334 JavaObjectNode* ptn = unique_java_object(base);
1335
1336 if (ptn != nullptr && ptn->scalar_replaceable()) {
1337 new_phi->set_req(i, null_ptr);
1338 } else {
1339 new_phi->set_req(i, ophi->in(i));
1340 }
1341 }
1342
1343 for (int i = ophi->outcnt()-1; i >= 0;) {
1344 Node* out = ophi->raw_out(i);
1345
1346 if (out->is_ConstraintCast()) {
1347 const Type* out_t = _igvn->type(out)->make_ptr();
1348 const Type* out_new_t = out_t->meet(TypePtr::NULL_PTR);
1349 bool change = out_new_t != out_t;
1350
1351 for (int j = out->outcnt()-1; change && j >= 0; --j) {
1352 Node* out2 = out->raw_out(j);
1353 if (!out2->is_SafePoint()) {
1354 change = false;
1355 break;
1356 }
1357 }
1358
1359 if (change) {
1360 Node* new_cast = ConstraintCastNode::make_cast_for_type(out->in(0), out->in(1), out_new_t, ConstraintCastNode::StrongDependency, nullptr);
1361 _igvn->replace_node(out, new_cast);
1362 _igvn->register_new_node_with_optimizer(new_cast);
1363 }
1364 }
1365
1366 --i;
1367 i = MIN2(i, (int)ophi->outcnt()-1);
1368 }
1369
1370 _igvn->replace_node(ophi, new_phi);
1371 }
1372
1373 void ConnectionGraph::verify_ram_nodes(Compile* C, Node* root) {
1374 if (!C->do_reduce_allocation_merges()) return;
1375
1376 Unique_Node_List ideal_nodes;
1377 ideal_nodes.map(C->live_nodes(), nullptr); // preallocate space
1378 ideal_nodes.push(root);
1379
1380 for (uint next = 0; next < ideal_nodes.size(); ++next) {
1381 Node* n = ideal_nodes.at(next);
1382
1383 if (n->is_SafePointScalarMerge()) {
1384 SafePointScalarMergeNode* merge = n->as_SafePointScalarMerge();
1385
1386 // Validate inputs of merge
1387 for (uint i = 1; i < merge->req(); i++) {
1388 if (merge->in(i) != nullptr && !merge->in(i)->is_top() && !merge->in(i)->is_SafePointScalarObject()) {
1389 assert(false, "SafePointScalarMerge inputs should be null/top or SafePointScalarObject.");
1390 C->record_failure(C2Compiler::retry_no_reduce_allocation_merges());
1391 }
1392 }
1393
1394 // Validate users of merge
1395 for (DUIterator_Fast imax, i = merge->fast_outs(imax); i < imax; i++) {
1396 Node* sfpt = merge->fast_out(i);
1397 if (sfpt->is_SafePoint()) {
1398 int merge_idx = merge->merge_pointer_idx(sfpt->as_SafePoint()->jvms());
1399
1400 if (sfpt->in(merge_idx) != nullptr && sfpt->in(merge_idx)->is_SafePointScalarMerge()) {
1401 assert(false, "SafePointScalarMerge nodes can't be nested.");
1402 C->record_failure(C2Compiler::retry_no_reduce_allocation_merges());
1403 }
1404 } else {
1405 assert(false, "Only safepoints can use SafePointScalarMerge nodes.");
1406 C->record_failure(C2Compiler::retry_no_reduce_allocation_merges());
1407 }
1408 }
1409 }
1410
1411 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1412 Node* m = n->fast_out(i);
1413 ideal_nodes.push(m);
1414 }
1415 }
1416 }
1417
1418 // Returns true if there is an object in the scope of sfn that does not escape globally.
1419 bool ConnectionGraph::has_ea_local_in_scope(SafePointNode* sfn) {
1420 Compile* C = _compile;
1421 for (JVMState* jvms = sfn->jvms(); jvms != nullptr; jvms = jvms->caller()) {
1422 if (C->env()->should_retain_local_variables() || C->env()->jvmti_can_walk_any_space() ||
1423 DeoptimizeObjectsALot) {
1424 // Jvmti agents can access locals. Must provide info about local objects at runtime.
1425 int num_locs = jvms->loc_size();
1426 for (int idx = 0; idx < num_locs; idx++) {
1427 Node* l = sfn->local(jvms, idx);
1428 if (not_global_escape(l)) {
1429 return true;
1430 }
1431 }
1432 }
1433 if (C->env()->jvmti_can_get_owned_monitor_info() ||
1434 C->env()->jvmti_can_walk_any_space() || DeoptimizeObjectsALot) {
1435 // Jvmti agents can read monitors. Must provide info about locked objects at runtime.
1436 int num_mon = jvms->nof_monitors();
1437 for (int idx = 0; idx < num_mon; idx++) {
1438 Node* m = sfn->monitor_obj(jvms, idx);
1439 if (m != nullptr && not_global_escape(m)) {
1440 return true;
1441 }
1442 }
1443 }
1444 }
1445 return false;
1446 }
1447
1448 // Returns true if at least one of the arguments to the call is an object
1449 // that does not escape globally.
1450 bool ConnectionGraph::has_arg_escape(CallJavaNode* call) {
1451 if (call->method() != nullptr) {
1452 uint max_idx = TypeFunc::Parms + call->method()->arg_size();
1453 for (uint idx = TypeFunc::Parms; idx < max_idx; idx++) {
1454 Node* p = call->in(idx);
1455 if (not_global_escape(p)) {
1456 return true;
1457 }
1458 }
1459 } else {
1460 const char* name = call->as_CallStaticJava()->_name;
1461 assert(name != nullptr, "no name");
1462 // no arg escapes through uncommon traps
1463 if (strcmp(name, "uncommon_trap") != 0) {
1464 // process_call_arguments() assumes that all arguments escape globally
1465 const TypeTuple* d = call->tf()->domain();
1466 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1467 const Type* at = d->field_at(i);
1468 if (at->isa_oopptr() != nullptr) {
1469 return true;
1470 }
1471 }
1472 }
1473 }
1474 return false;
1475 }
1476
1477
1478
1479 // Utility function for nodes that load an object
1480 void ConnectionGraph::add_objload_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
1481 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
1482 // ThreadLocal has RawPtr type.
1483 const Type* t = _igvn->type(n);
1484 if (t->make_ptr() != nullptr) {
1485 Node* adr = n->in(MemNode::Address);
1486 #ifdef ASSERT
1487 if (!adr->is_AddP()) {
1488 assert(_igvn->type(adr)->isa_rawptr(), "sanity");
1489 } else {
1490 assert((ptnode_adr(adr->_idx) == nullptr ||
1491 ptnode_adr(adr->_idx)->as_Field()->is_oop()), "sanity");
1492 }
1493 #endif
1494 add_local_var_and_edge(n, PointsToNode::NoEscape,
1495 adr, delayed_worklist);
1496 }
1497 }
1498
1499 // Populate Connection Graph with PointsTo nodes and create simple
1500 // connection graph edges.
1501 void ConnectionGraph::add_node_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
1502 assert(!_verify, "this method should not be called for verification");
1503 PhaseGVN* igvn = _igvn;
1504 uint n_idx = n->_idx;
1505 PointsToNode* n_ptn = ptnode_adr(n_idx);
1506 if (n_ptn != nullptr) {
1507 return; // No need to redefine PointsTo node during first iteration.
1508 }
1509 int opcode = n->Opcode();
1510 bool gc_handled = BarrierSet::barrier_set()->barrier_set_c2()->escape_add_to_con_graph(this, igvn, delayed_worklist, n, opcode);
1511 if (gc_handled) {
1512 return; // Ignore node if already handled by GC.
1513 }
1514
1515 if (n->is_Call()) {
1516 // Arguments to allocation and locking don't escape.
1517 if (n->is_AbstractLock()) {
1518 // Put Lock and Unlock nodes on IGVN worklist to process them during
1519 // first IGVN optimization when escape information is still available.
1520 record_for_optimizer(n);
1521 } else if (n->is_Allocate()) {
1522 add_call_node(n->as_Call());
1523 record_for_optimizer(n);
1524 } else {
1525 if (n->is_CallStaticJava()) {
1526 const char* name = n->as_CallStaticJava()->_name;
1527 if (name != nullptr && strcmp(name, "uncommon_trap") == 0) {
1528 return; // Skip uncommon traps
1529 }
1530 }
1531 // Don't mark as processed since call's arguments have to be processed.
1532 delayed_worklist->push(n);
1533 // Check if a call returns an object.
1534 if ((n->as_Call()->returns_pointer() &&
1535 n->as_Call()->proj_out_or_null(TypeFunc::Parms) != nullptr) ||
1536 (n->is_CallStaticJava() &&
1537 n->as_CallStaticJava()->is_boxing_method())) {
1538 add_call_node(n->as_Call());
1539 }
1540 }
1541 return;
1542 }
1543 // Put this check here to process call arguments since some call nodes
1544 // point to phantom_obj.
1545 if (n_ptn == phantom_obj || n_ptn == null_obj) {
1546 return; // Skip predefined nodes.
1547 }
1548 switch (opcode) {
1549 case Op_AddP: {
1550 Node* base = get_addp_base(n);
1551 PointsToNode* ptn_base = ptnode_adr(base->_idx);
1552 // Field nodes are created for all field types. They are used in
1553 // adjust_scalar_replaceable_state() and split_unique_types().
1554 // Note, non-oop fields will have only base edges in Connection
1555 // Graph because such fields are not used for oop loads and stores.
1556 int offset = address_offset(n, igvn);
1557 add_field(n, PointsToNode::NoEscape, offset);
1558 if (ptn_base == nullptr) {
1559 delayed_worklist->push(n); // Process it later.
1560 } else {
1561 n_ptn = ptnode_adr(n_idx);
1562 add_base(n_ptn->as_Field(), ptn_base);
1563 }
1564 break;
1565 }
1566 case Op_CastX2P: {
1567 map_ideal_node(n, phantom_obj);
1568 break;
1569 }
1570 case Op_CastPP:
1571 case Op_CheckCastPP:
1572 case Op_EncodeP:
1573 case Op_DecodeN:
1574 case Op_EncodePKlass:
1575 case Op_DecodeNKlass: {
1576 add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(1), delayed_worklist);
1577 break;
1578 }
1579 case Op_CMoveP: {
1580 add_local_var(n, PointsToNode::NoEscape);
1581 // Do not add edges during first iteration because some could be
1582 // not defined yet.
1583 delayed_worklist->push(n);
1584 break;
1585 }
1586 case Op_ConP:
1587 case Op_ConN:
1588 case Op_ConNKlass: {
1589 // assume all oop constants globally escape except for null
1590 PointsToNode::EscapeState es;
1591 const Type* t = igvn->type(n);
1592 if (t == TypePtr::NULL_PTR || t == TypeNarrowOop::NULL_PTR) {
1593 es = PointsToNode::NoEscape;
1594 } else {
1595 es = PointsToNode::GlobalEscape;
1596 }
1597 PointsToNode* ptn_con = add_java_object(n, es);
1598 set_not_scalar_replaceable(ptn_con NOT_PRODUCT(COMMA "Constant pointer"));
1599 break;
1600 }
1601 case Op_CreateEx: {
1602 // assume that all exception objects globally escape
1603 map_ideal_node(n, phantom_obj);
1604 break;
1605 }
1606 case Op_LoadKlass:
1607 case Op_LoadNKlass: {
1608 // Unknown class is loaded
1609 map_ideal_node(n, phantom_obj);
1610 break;
1611 }
1612 case Op_LoadP:
1613 case Op_LoadN: {
1614 add_objload_to_connection_graph(n, delayed_worklist);
1615 break;
1616 }
1617 case Op_Parm: {
1618 map_ideal_node(n, phantom_obj);
1619 break;
1620 }
1621 case Op_PartialSubtypeCheck: {
1622 // Produces Null or notNull and is used in only in CmpP so
1623 // phantom_obj could be used.
1624 map_ideal_node(n, phantom_obj); // Result is unknown
1625 break;
1626 }
1627 case Op_Phi: {
1628 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
1629 // ThreadLocal has RawPtr type.
1630 const Type* t = n->as_Phi()->type();
1631 if (t->make_ptr() != nullptr) {
1632 add_local_var(n, PointsToNode::NoEscape);
1633 // Do not add edges during first iteration because some could be
1634 // not defined yet.
1635 delayed_worklist->push(n);
1636 }
1637 break;
1638 }
1639 case Op_Proj: {
1640 // we are only interested in the oop result projection from a call
1641 if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
1642 n->in(0)->as_Call()->returns_pointer()) {
1643 add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(0), delayed_worklist);
1644 }
1645 break;
1646 }
1647 case Op_Rethrow: // Exception object escapes
1648 case Op_Return: {
1649 if (n->req() > TypeFunc::Parms &&
1650 igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
1651 // Treat Return value as LocalVar with GlobalEscape escape state.
1652 add_local_var_and_edge(n, PointsToNode::GlobalEscape, n->in(TypeFunc::Parms), delayed_worklist);
1653 }
1654 break;
1655 }
1656 case Op_CompareAndExchangeP:
1657 case Op_CompareAndExchangeN:
1658 case Op_GetAndSetP:
1659 case Op_GetAndSetN: {
1660 add_objload_to_connection_graph(n, delayed_worklist);
1661 // fall-through
1662 }
1663 case Op_StoreP:
1664 case Op_StoreN:
1665 case Op_StoreNKlass:
1666 case Op_WeakCompareAndSwapP:
1667 case Op_WeakCompareAndSwapN:
1668 case Op_CompareAndSwapP:
1669 case Op_CompareAndSwapN: {
1670 add_to_congraph_unsafe_access(n, opcode, delayed_worklist);
1671 break;
1672 }
1673 case Op_AryEq:
1674 case Op_CountPositives:
1675 case Op_StrComp:
1676 case Op_StrEquals:
1677 case Op_StrIndexOf:
1678 case Op_StrIndexOfChar:
1679 case Op_StrInflatedCopy:
1680 case Op_StrCompressedCopy:
1681 case Op_VectorizedHashCode:
1682 case Op_EncodeISOArray: {
1683 add_local_var(n, PointsToNode::ArgEscape);
1684 delayed_worklist->push(n); // Process it later.
1685 break;
1686 }
1687 case Op_ThreadLocal: {
1688 PointsToNode* ptn_thr = add_java_object(n, PointsToNode::ArgEscape);
1689 set_not_scalar_replaceable(ptn_thr NOT_PRODUCT(COMMA "Constant pointer"));
1690 break;
1691 }
1692 case Op_Blackhole: {
1693 // All blackhole pointer arguments are globally escaping.
1694 // Only do this if there is at least one pointer argument.
1695 // Do not add edges during first iteration because some could be
1696 // not defined yet, defer to final step.
1697 for (uint i = 0; i < n->req(); i++) {
1698 Node* in = n->in(i);
1699 if (in != nullptr) {
1700 const Type* at = _igvn->type(in);
1701 if (!at->isa_ptr()) continue;
1702
1703 add_local_var(n, PointsToNode::GlobalEscape);
1704 delayed_worklist->push(n);
1705 break;
1706 }
1707 }
1708 break;
1709 }
1710 default:
1711 ; // Do nothing for nodes not related to EA.
1712 }
1713 return;
1714 }
1715
1716 // Add final simple edges to graph.
1717 void ConnectionGraph::add_final_edges(Node *n) {
1718 PointsToNode* n_ptn = ptnode_adr(n->_idx);
1719 #ifdef ASSERT
1720 if (_verify && n_ptn->is_JavaObject())
1721 return; // This method does not change graph for JavaObject.
1722 #endif
1723
1724 if (n->is_Call()) {
1725 process_call_arguments(n->as_Call());
1726 return;
1727 }
1728 assert(n->is_Store() || n->is_LoadStore() ||
1729 ((n_ptn != nullptr) && (n_ptn->ideal_node() != nullptr)),
1730 "node should be registered already");
1731 int opcode = n->Opcode();
1732 bool gc_handled = BarrierSet::barrier_set()->barrier_set_c2()->escape_add_final_edges(this, _igvn, n, opcode);
1733 if (gc_handled) {
1734 return; // Ignore node if already handled by GC.
1735 }
1736 switch (opcode) {
1737 case Op_AddP: {
1738 Node* base = get_addp_base(n);
1739 PointsToNode* ptn_base = ptnode_adr(base->_idx);
1740 assert(ptn_base != nullptr, "field's base should be registered");
1741 add_base(n_ptn->as_Field(), ptn_base);
1742 break;
1743 }
1744 case Op_CastPP:
1745 case Op_CheckCastPP:
1746 case Op_EncodeP:
1747 case Op_DecodeN:
1748 case Op_EncodePKlass:
1749 case Op_DecodeNKlass: {
1750 add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(1), nullptr);
1751 break;
1752 }
1753 case Op_CMoveP: {
1754 for (uint i = CMoveNode::IfFalse; i < n->req(); i++) {
1755 Node* in = n->in(i);
1756 if (in == nullptr) {
1757 continue; // ignore null
1758 }
1759 Node* uncast_in = in->uncast();
1760 if (uncast_in->is_top() || uncast_in == n) {
1761 continue; // ignore top or inputs which go back this node
1762 }
1763 PointsToNode* ptn = ptnode_adr(in->_idx);
1764 assert(ptn != nullptr, "node should be registered");
1765 add_edge(n_ptn, ptn);
1766 }
1767 break;
1768 }
1769 case Op_LoadP:
1770 case Op_LoadN: {
1771 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
1772 // ThreadLocal has RawPtr type.
1773 assert(_igvn->type(n)->make_ptr() != nullptr, "Unexpected node type");
1774 add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(MemNode::Address), nullptr);
1775 break;
1776 }
1777 case Op_Phi: {
1778 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
1779 // ThreadLocal has RawPtr type.
1780 assert(n->as_Phi()->type()->make_ptr() != nullptr, "Unexpected node type");
1781 for (uint i = 1; i < n->req(); i++) {
1782 Node* in = n->in(i);
1783 if (in == nullptr) {
1784 continue; // ignore null
1785 }
1786 Node* uncast_in = in->uncast();
1787 if (uncast_in->is_top() || uncast_in == n) {
1788 continue; // ignore top or inputs which go back this node
1789 }
1790 PointsToNode* ptn = ptnode_adr(in->_idx);
1791 assert(ptn != nullptr, "node should be registered");
1792 add_edge(n_ptn, ptn);
1793 }
1794 break;
1795 }
1796 case Op_Proj: {
1797 // we are only interested in the oop result projection from a call
1798 assert(n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
1799 n->in(0)->as_Call()->returns_pointer(), "Unexpected node type");
1800 add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(0), nullptr);
1801 break;
1802 }
1803 case Op_Rethrow: // Exception object escapes
1804 case Op_Return: {
1805 assert(n->req() > TypeFunc::Parms && _igvn->type(n->in(TypeFunc::Parms))->isa_oopptr(),
1806 "Unexpected node type");
1807 // Treat Return value as LocalVar with GlobalEscape escape state.
1808 add_local_var_and_edge(n, PointsToNode::GlobalEscape, n->in(TypeFunc::Parms), nullptr);
1809 break;
1810 }
1811 case Op_CompareAndExchangeP:
1812 case Op_CompareAndExchangeN:
1813 case Op_GetAndSetP:
1814 case Op_GetAndSetN:{
1815 assert(_igvn->type(n)->make_ptr() != nullptr, "Unexpected node type");
1816 add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(MemNode::Address), nullptr);
1817 // fall-through
1818 }
1819 case Op_CompareAndSwapP:
1820 case Op_CompareAndSwapN:
1821 case Op_WeakCompareAndSwapP:
1822 case Op_WeakCompareAndSwapN:
1823 case Op_StoreP:
1824 case Op_StoreN:
1825 case Op_StoreNKlass:{
1826 add_final_edges_unsafe_access(n, opcode);
1827 break;
1828 }
1829 case Op_VectorizedHashCode:
1830 case Op_AryEq:
1831 case Op_CountPositives:
1832 case Op_StrComp:
1833 case Op_StrEquals:
1834 case Op_StrIndexOf:
1835 case Op_StrIndexOfChar:
1836 case Op_StrInflatedCopy:
1837 case Op_StrCompressedCopy:
1838 case Op_EncodeISOArray: {
1839 // char[]/byte[] arrays passed to string intrinsic do not escape but
1840 // they are not scalar replaceable. Adjust escape state for them.
1841 // Start from in(2) edge since in(1) is memory edge.
1842 for (uint i = 2; i < n->req(); i++) {
1843 Node* adr = n->in(i);
1844 const Type* at = _igvn->type(adr);
1845 if (!adr->is_top() && at->isa_ptr()) {
1846 assert(at == Type::TOP || at == TypePtr::NULL_PTR ||
1847 at->isa_ptr() != nullptr, "expecting a pointer");
1848 if (adr->is_AddP()) {
1849 adr = get_addp_base(adr);
1850 }
1851 PointsToNode* ptn = ptnode_adr(adr->_idx);
1852 assert(ptn != nullptr, "node should be registered");
1853 add_edge(n_ptn, ptn);
1854 }
1855 }
1856 break;
1857 }
1858 case Op_Blackhole: {
1859 // All blackhole pointer arguments are globally escaping.
1860 for (uint i = 0; i < n->req(); i++) {
1861 Node* in = n->in(i);
1862 if (in != nullptr) {
1863 const Type* at = _igvn->type(in);
1864 if (!at->isa_ptr()) continue;
1865
1866 if (in->is_AddP()) {
1867 in = get_addp_base(in);
1868 }
1869
1870 PointsToNode* ptn = ptnode_adr(in->_idx);
1871 assert(ptn != nullptr, "should be defined already");
1872 set_escape_state(ptn, PointsToNode::GlobalEscape NOT_PRODUCT(COMMA "blackhole"));
1873 add_edge(n_ptn, ptn);
1874 }
1875 }
1876 break;
1877 }
1878 default: {
1879 // This method should be called only for EA specific nodes which may
1880 // miss some edges when they were created.
1881 #ifdef ASSERT
1882 n->dump(1);
1883 #endif
1884 guarantee(false, "unknown node");
1885 }
1886 }
1887 return;
1888 }
1889
1890 void ConnectionGraph::add_to_congraph_unsafe_access(Node* n, uint opcode, Unique_Node_List* delayed_worklist) {
1891 Node* adr = n->in(MemNode::Address);
1892 const Type* adr_type = _igvn->type(adr);
1893 adr_type = adr_type->make_ptr();
1894 if (adr_type == nullptr) {
1895 return; // skip dead nodes
1896 }
1897 if (adr_type->isa_oopptr()
1898 || ((opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass)
1899 && adr_type == TypeRawPtr::NOTNULL
1900 && is_captured_store_address(adr))) {
1901 delayed_worklist->push(n); // Process it later.
1902 #ifdef ASSERT
1903 assert (adr->is_AddP(), "expecting an AddP");
1904 if (adr_type == TypeRawPtr::NOTNULL) {
1905 // Verify a raw address for a store captured by Initialize node.
1906 int offs = (int) _igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
1907 assert(offs != Type::OffsetBot, "offset must be a constant");
1908 }
1909 #endif
1910 } else {
1911 // Ignore copy the displaced header to the BoxNode (OSR compilation).
1912 if (adr->is_BoxLock()) {
1913 return;
1914 }
1915 // Stored value escapes in unsafe access.
1916 if ((opcode == Op_StoreP) && adr_type->isa_rawptr()) {
1917 delayed_worklist->push(n); // Process unsafe access later.
1918 return;
1919 }
1920 #ifdef ASSERT
1921 n->dump(1);
1922 assert(false, "not unsafe");
1923 #endif
1924 }
1925 }
1926
1927 bool ConnectionGraph::add_final_edges_unsafe_access(Node* n, uint opcode) {
1928 Node* adr = n->in(MemNode::Address);
1929 const Type *adr_type = _igvn->type(adr);
1930 adr_type = adr_type->make_ptr();
1931 #ifdef ASSERT
1932 if (adr_type == nullptr) {
1933 n->dump(1);
1934 assert(adr_type != nullptr, "dead node should not be on list");
1935 return true;
1936 }
1937 #endif
1938
1939 if (adr_type->isa_oopptr()
1940 || ((opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass)
1941 && adr_type == TypeRawPtr::NOTNULL
1942 && is_captured_store_address(adr))) {
1943 // Point Address to Value
1944 PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
1945 assert(adr_ptn != nullptr &&
1946 adr_ptn->as_Field()->is_oop(), "node should be registered");
1947 Node* val = n->in(MemNode::ValueIn);
1948 PointsToNode* ptn = ptnode_adr(val->_idx);
1949 assert(ptn != nullptr, "node should be registered");
1950 add_edge(adr_ptn, ptn);
1951 return true;
1952 } else if ((opcode == Op_StoreP) && adr_type->isa_rawptr()) {
1953 // Stored value escapes in unsafe access.
1954 Node* val = n->in(MemNode::ValueIn);
1955 PointsToNode* ptn = ptnode_adr(val->_idx);
1956 assert(ptn != nullptr, "node should be registered");
1957 set_escape_state(ptn, PointsToNode::GlobalEscape NOT_PRODUCT(COMMA "stored at raw address"));
1958 // Add edge to object for unsafe access with offset.
1959 PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
1960 assert(adr_ptn != nullptr, "node should be registered");
1961 if (adr_ptn->is_Field()) {
1962 assert(adr_ptn->as_Field()->is_oop(), "should be oop field");
1963 add_edge(adr_ptn, ptn);
1964 }
1965 return true;
1966 }
1967 #ifdef ASSERT
1968 n->dump(1);
1969 assert(false, "not unsafe");
1970 #endif
1971 return false;
1972 }
1973
1974 void ConnectionGraph::add_call_node(CallNode* call) {
1975 assert(call->returns_pointer(), "only for call which returns pointer");
1976 uint call_idx = call->_idx;
1977 if (call->is_Allocate()) {
1978 Node* k = call->in(AllocateNode::KlassNode);
1979 const TypeKlassPtr* kt = k->bottom_type()->isa_klassptr();
1980 assert(kt != nullptr, "TypeKlassPtr required.");
1981 PointsToNode::EscapeState es = PointsToNode::NoEscape;
1982 bool scalar_replaceable = true;
1983 NOT_PRODUCT(const char* nsr_reason = "");
1984 if (call->is_AllocateArray()) {
1985 if (!kt->isa_aryklassptr()) { // StressReflectiveCode
1986 es = PointsToNode::GlobalEscape;
1987 } else {
1988 int length = call->in(AllocateNode::ALength)->find_int_con(-1);
1989 if (length < 0) {
1990 // Not scalar replaceable if the length is not constant.
1991 scalar_replaceable = false;
1992 NOT_PRODUCT(nsr_reason = "has a non-constant length");
1993 } else if (length > EliminateAllocationArraySizeLimit) {
1994 // Not scalar replaceable if the length is too big.
1995 scalar_replaceable = false;
1996 NOT_PRODUCT(nsr_reason = "has a length that is too big");
1997 }
1998 }
1999 } else { // Allocate instance
2000 if (!kt->isa_instklassptr()) { // StressReflectiveCode
2001 es = PointsToNode::GlobalEscape;
2002 } else {
2003 const TypeInstKlassPtr* ikt = kt->is_instklassptr();
2004 ciInstanceKlass* ik = ikt->klass_is_exact() ? ikt->exact_klass()->as_instance_klass() : ikt->instance_klass();
2005 if (ik->is_subclass_of(_compile->env()->Thread_klass()) ||
2006 ik->is_subclass_of(_compile->env()->Reference_klass()) ||
2007 !ik->can_be_instantiated() ||
2008 ik->has_finalizer()) {
2009 es = PointsToNode::GlobalEscape;
2010 } else {
2011 int nfields = ik->as_instance_klass()->nof_nonstatic_fields();
2012 if (nfields > EliminateAllocationFieldsLimit) {
2013 // Not scalar replaceable if there are too many fields.
2014 scalar_replaceable = false;
2015 NOT_PRODUCT(nsr_reason = "has too many fields");
2016 }
2017 }
2018 }
2019 }
2020 add_java_object(call, es);
2021 PointsToNode* ptn = ptnode_adr(call_idx);
2022 if (!scalar_replaceable && ptn->scalar_replaceable()) {
2023 set_not_scalar_replaceable(ptn NOT_PRODUCT(COMMA nsr_reason));
2024 }
2025 } else if (call->is_CallStaticJava()) {
2026 // Call nodes could be different types:
2027 //
2028 // 1. CallDynamicJavaNode (what happened during call is unknown):
2029 //
2030 // - mapped to GlobalEscape JavaObject node if oop is returned;
2031 //
2032 // - all oop arguments are escaping globally;
2033 //
2034 // 2. CallStaticJavaNode (execute bytecode analysis if possible):
2035 //
2036 // - the same as CallDynamicJavaNode if can't do bytecode analysis;
2037 //
2038 // - mapped to GlobalEscape JavaObject node if unknown oop is returned;
2039 // - mapped to NoEscape JavaObject node if non-escaping object allocated
2040 // during call is returned;
2041 // - mapped to ArgEscape LocalVar node pointed to object arguments
2042 // which are returned and does not escape during call;
2043 //
2044 // - oop arguments escaping status is defined by bytecode analysis;
2045 //
2046 // For a static call, we know exactly what method is being called.
2047 // Use bytecode estimator to record whether the call's return value escapes.
2048 ciMethod* meth = call->as_CallJava()->method();
2049 if (meth == nullptr) {
2050 const char* name = call->as_CallStaticJava()->_name;
2051 assert(strncmp(name, "C2 Runtime multianewarray", 25) == 0, "TODO: add failed case check");
2052 // Returns a newly allocated non-escaped object.
2053 add_java_object(call, PointsToNode::NoEscape);
2054 set_not_scalar_replaceable(ptnode_adr(call_idx) NOT_PRODUCT(COMMA "is result of multinewarray"));
2055 } else if (meth->is_boxing_method()) {
2056 // Returns boxing object
2057 PointsToNode::EscapeState es;
2058 vmIntrinsics::ID intr = meth->intrinsic_id();
2059 if (intr == vmIntrinsics::_floatValue || intr == vmIntrinsics::_doubleValue) {
2060 // It does not escape if object is always allocated.
2061 es = PointsToNode::NoEscape;
2062 } else {
2063 // It escapes globally if object could be loaded from cache.
2064 es = PointsToNode::GlobalEscape;
2065 }
2066 add_java_object(call, es);
2067 if (es == PointsToNode::GlobalEscape) {
2068 set_not_scalar_replaceable(ptnode_adr(call->_idx) NOT_PRODUCT(COMMA "object can be loaded from boxing cache"));
2069 }
2070 } else {
2071 BCEscapeAnalyzer* call_analyzer = meth->get_bcea();
2072 call_analyzer->copy_dependencies(_compile->dependencies());
2073 if (call_analyzer->is_return_allocated()) {
2074 // Returns a newly allocated non-escaped object, simply
2075 // update dependency information.
2076 // Mark it as NoEscape so that objects referenced by
2077 // it's fields will be marked as NoEscape at least.
2078 add_java_object(call, PointsToNode::NoEscape);
2079 set_not_scalar_replaceable(ptnode_adr(call_idx) NOT_PRODUCT(COMMA "is result of call"));
2080 } else {
2081 // Determine whether any arguments are returned.
2082 const TypeTuple* d = call->tf()->domain();
2083 bool ret_arg = false;
2084 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
2085 if (d->field_at(i)->isa_ptr() != nullptr &&
2086 call_analyzer->is_arg_returned(i - TypeFunc::Parms)) {
2087 ret_arg = true;
2088 break;
2089 }
2090 }
2091 if (ret_arg) {
2092 add_local_var(call, PointsToNode::ArgEscape);
2093 } else {
2094 // Returns unknown object.
2095 map_ideal_node(call, phantom_obj);
2096 }
2097 }
2098 }
2099 } else {
2100 // An other type of call, assume the worst case:
2101 // returned value is unknown and globally escapes.
2102 assert(call->Opcode() == Op_CallDynamicJava, "add failed case check");
2103 map_ideal_node(call, phantom_obj);
2104 }
2105 }
2106
2107 void ConnectionGraph::process_call_arguments(CallNode *call) {
2108 bool is_arraycopy = false;
2109 switch (call->Opcode()) {
2110 #ifdef ASSERT
2111 case Op_Allocate:
2112 case Op_AllocateArray:
2113 case Op_Lock:
2114 case Op_Unlock:
2115 assert(false, "should be done already");
2116 break;
2117 #endif
2118 case Op_ArrayCopy:
2119 case Op_CallLeafNoFP:
2120 // Most array copies are ArrayCopy nodes at this point but there
2121 // are still a few direct calls to the copy subroutines (See
2122 // PhaseStringOpts::copy_string())
2123 is_arraycopy = (call->Opcode() == Op_ArrayCopy) ||
2124 call->as_CallLeaf()->is_call_to_arraycopystub();
2125 // fall through
2126 case Op_CallLeafVector:
2127 case Op_CallLeaf: {
2128 // Stub calls, objects do not escape but they are not scale replaceable.
2129 // Adjust escape state for outgoing arguments.
2130 const TypeTuple * d = call->tf()->domain();
2131 bool src_has_oops = false;
2132 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
2133 const Type* at = d->field_at(i);
2134 Node *arg = call->in(i);
2135 if (arg == nullptr) {
2136 continue;
2137 }
2138 const Type *aat = _igvn->type(arg);
2139 if (arg->is_top() || !at->isa_ptr() || !aat->isa_ptr()) {
2140 continue;
2141 }
2142 if (arg->is_AddP()) {
2143 //
2144 // The inline_native_clone() case when the arraycopy stub is called
2145 // after the allocation before Initialize and CheckCastPP nodes.
2146 // Or normal arraycopy for object arrays case.
2147 //
2148 // Set AddP's base (Allocate) as not scalar replaceable since
2149 // pointer to the base (with offset) is passed as argument.
2150 //
2151 arg = get_addp_base(arg);
2152 }
2153 PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
2154 assert(arg_ptn != nullptr, "should be registered");
2155 PointsToNode::EscapeState arg_esc = arg_ptn->escape_state();
2156 if (is_arraycopy || arg_esc < PointsToNode::ArgEscape) {
2157 assert(aat == Type::TOP || aat == TypePtr::NULL_PTR ||
2158 aat->isa_ptr() != nullptr, "expecting an Ptr");
2159 bool arg_has_oops = aat->isa_oopptr() &&
2160 (aat->isa_instptr() ||
2161 (aat->isa_aryptr() && (aat->isa_aryptr()->elem() == Type::BOTTOM || aat->isa_aryptr()->elem()->make_oopptr() != nullptr)));
2162 if (i == TypeFunc::Parms) {
2163 src_has_oops = arg_has_oops;
2164 }
2165 //
2166 // src or dst could be j.l.Object when other is basic type array:
2167 //
2168 // arraycopy(char[],0,Object*,0,size);
2169 // arraycopy(Object*,0,char[],0,size);
2170 //
2171 // Don't add edges in such cases.
2172 //
2173 bool arg_is_arraycopy_dest = src_has_oops && is_arraycopy &&
2174 arg_has_oops && (i > TypeFunc::Parms);
2175 #ifdef ASSERT
2176 if (!(is_arraycopy ||
2177 BarrierSet::barrier_set()->barrier_set_c2()->is_gc_barrier_node(call) ||
2178 (call->as_CallLeaf()->_name != nullptr &&
2179 (strcmp(call->as_CallLeaf()->_name, "updateBytesCRC32") == 0 ||
2180 strcmp(call->as_CallLeaf()->_name, "updateBytesCRC32C") == 0 ||
2181 strcmp(call->as_CallLeaf()->_name, "updateBytesAdler32") == 0 ||
2182 strcmp(call->as_CallLeaf()->_name, "aescrypt_encryptBlock") == 0 ||
2183 strcmp(call->as_CallLeaf()->_name, "aescrypt_decryptBlock") == 0 ||
2184 strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_encryptAESCrypt") == 0 ||
2185 strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_decryptAESCrypt") == 0 ||
2186 strcmp(call->as_CallLeaf()->_name, "electronicCodeBook_encryptAESCrypt") == 0 ||
2187 strcmp(call->as_CallLeaf()->_name, "electronicCodeBook_decryptAESCrypt") == 0 ||
2188 strcmp(call->as_CallLeaf()->_name, "counterMode_AESCrypt") == 0 ||
2189 strcmp(call->as_CallLeaf()->_name, "galoisCounterMode_AESCrypt") == 0 ||
2190 strcmp(call->as_CallLeaf()->_name, "poly1305_processBlocks") == 0 ||
2191 strcmp(call->as_CallLeaf()->_name, "intpoly_montgomeryMult_P256") == 0 ||
2192 strcmp(call->as_CallLeaf()->_name, "intpoly_assign") == 0 ||
2193 strcmp(call->as_CallLeaf()->_name, "ghash_processBlocks") == 0 ||
2194 strcmp(call->as_CallLeaf()->_name, "chacha20Block") == 0 ||
2195 strcmp(call->as_CallLeaf()->_name, "dilithiumAlmostNtt") == 0 ||
2196 strcmp(call->as_CallLeaf()->_name, "dilithiumAlmostInverseNtt") == 0 ||
2197 strcmp(call->as_CallLeaf()->_name, "dilithiumNttMult") == 0 ||
2198 strcmp(call->as_CallLeaf()->_name, "dilithiumMontMulByConstant") == 0 ||
2199 strcmp(call->as_CallLeaf()->_name, "dilithiumDecomposePoly") == 0 ||
2200 strcmp(call->as_CallLeaf()->_name, "encodeBlock") == 0 ||
2201 strcmp(call->as_CallLeaf()->_name, "decodeBlock") == 0 ||
2202 strcmp(call->as_CallLeaf()->_name, "md5_implCompress") == 0 ||
2203 strcmp(call->as_CallLeaf()->_name, "md5_implCompressMB") == 0 ||
2204 strcmp(call->as_CallLeaf()->_name, "sha1_implCompress") == 0 ||
2205 strcmp(call->as_CallLeaf()->_name, "sha1_implCompressMB") == 0 ||
2206 strcmp(call->as_CallLeaf()->_name, "sha256_implCompress") == 0 ||
2207 strcmp(call->as_CallLeaf()->_name, "sha256_implCompressMB") == 0 ||
2208 strcmp(call->as_CallLeaf()->_name, "sha512_implCompress") == 0 ||
2209 strcmp(call->as_CallLeaf()->_name, "sha512_implCompressMB") == 0 ||
2210 strcmp(call->as_CallLeaf()->_name, "sha3_implCompress") == 0 ||
2211 strcmp(call->as_CallLeaf()->_name, "double_keccak") == 0 ||
2212 strcmp(call->as_CallLeaf()->_name, "sha3_implCompressMB") == 0 ||
2213 strcmp(call->as_CallLeaf()->_name, "multiplyToLen") == 0 ||
2214 strcmp(call->as_CallLeaf()->_name, "squareToLen") == 0 ||
2215 strcmp(call->as_CallLeaf()->_name, "mulAdd") == 0 ||
2216 strcmp(call->as_CallLeaf()->_name, "montgomery_multiply") == 0 ||
2217 strcmp(call->as_CallLeaf()->_name, "montgomery_square") == 0 ||
2218 strcmp(call->as_CallLeaf()->_name, "bigIntegerRightShiftWorker") == 0 ||
2219 strcmp(call->as_CallLeaf()->_name, "bigIntegerLeftShiftWorker") == 0 ||
2220 strcmp(call->as_CallLeaf()->_name, "vectorizedMismatch") == 0 ||
2221 strcmp(call->as_CallLeaf()->_name, "stringIndexOf") == 0 ||
2222 strcmp(call->as_CallLeaf()->_name, "arraysort_stub") == 0 ||
2223 strcmp(call->as_CallLeaf()->_name, "array_partition_stub") == 0 ||
2224 strcmp(call->as_CallLeaf()->_name, "get_class_id_intrinsic") == 0 ||
2225 strcmp(call->as_CallLeaf()->_name, "unsafe_setmemory") == 0)
2226 ))) {
2227 call->dump();
2228 fatal("EA unexpected CallLeaf %s", call->as_CallLeaf()->_name);
2229 }
2230 #endif
2231 // Always process arraycopy's destination object since
2232 // we need to add all possible edges to references in
2233 // source object.
2234 if (arg_esc >= PointsToNode::ArgEscape &&
2235 !arg_is_arraycopy_dest) {
2236 continue;
2237 }
2238 PointsToNode::EscapeState es = PointsToNode::ArgEscape;
2239 if (call->is_ArrayCopy()) {
2240 ArrayCopyNode* ac = call->as_ArrayCopy();
2241 if (ac->is_clonebasic() ||
2242 ac->is_arraycopy_validated() ||
2243 ac->is_copyof_validated() ||
2244 ac->is_copyofrange_validated()) {
2245 es = PointsToNode::NoEscape;
2246 }
2247 }
2248 set_escape_state(arg_ptn, es NOT_PRODUCT(COMMA trace_arg_escape_message(call)));
2249 if (arg_is_arraycopy_dest) {
2250 Node* src = call->in(TypeFunc::Parms);
2251 if (src->is_AddP()) {
2252 src = get_addp_base(src);
2253 }
2254 PointsToNode* src_ptn = ptnode_adr(src->_idx);
2255 assert(src_ptn != nullptr, "should be registered");
2256 if (arg_ptn != src_ptn) {
2257 // Special arraycopy edge:
2258 // A destination object's field can't have the source object
2259 // as base since objects escape states are not related.
2260 // Only escape state of destination object's fields affects
2261 // escape state of fields in source object.
2262 add_arraycopy(call, es, src_ptn, arg_ptn);
2263 }
2264 }
2265 }
2266 }
2267 break;
2268 }
2269 case Op_CallStaticJava: {
2270 // For a static call, we know exactly what method is being called.
2271 // Use bytecode estimator to record the call's escape affects
2272 #ifdef ASSERT
2273 const char* name = call->as_CallStaticJava()->_name;
2274 assert((name == nullptr || strcmp(name, "uncommon_trap") != 0), "normal calls only");
2275 #endif
2276 ciMethod* meth = call->as_CallJava()->method();
2277 if ((meth != nullptr) && meth->is_boxing_method()) {
2278 break; // Boxing methods do not modify any oops.
2279 }
2280 BCEscapeAnalyzer* call_analyzer = (meth !=nullptr) ? meth->get_bcea() : nullptr;
2281 // fall-through if not a Java method or no analyzer information
2282 if (call_analyzer != nullptr) {
2283 PointsToNode* call_ptn = ptnode_adr(call->_idx);
2284 const TypeTuple* d = call->tf()->domain();
2285 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
2286 const Type* at = d->field_at(i);
2287 int k = i - TypeFunc::Parms;
2288 Node* arg = call->in(i);
2289 PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
2290 if (at->isa_ptr() != nullptr &&
2291 call_analyzer->is_arg_returned(k)) {
2292 // The call returns arguments.
2293 if (call_ptn != nullptr) { // Is call's result used?
2294 assert(call_ptn->is_LocalVar(), "node should be registered");
2295 assert(arg_ptn != nullptr, "node should be registered");
2296 add_edge(call_ptn, arg_ptn);
2297 }
2298 }
2299 if (at->isa_oopptr() != nullptr &&
2300 arg_ptn->escape_state() < PointsToNode::GlobalEscape) {
2301 if (!call_analyzer->is_arg_stack(k)) {
2302 // The argument global escapes
2303 set_escape_state(arg_ptn, PointsToNode::GlobalEscape NOT_PRODUCT(COMMA trace_arg_escape_message(call)));
2304 } else {
2305 set_escape_state(arg_ptn, PointsToNode::ArgEscape NOT_PRODUCT(COMMA trace_arg_escape_message(call)));
2306 if (!call_analyzer->is_arg_local(k)) {
2307 // The argument itself doesn't escape, but any fields might
2308 set_fields_escape_state(arg_ptn, PointsToNode::GlobalEscape NOT_PRODUCT(COMMA trace_arg_escape_message(call)));
2309 }
2310 }
2311 }
2312 }
2313 if (call_ptn != nullptr && call_ptn->is_LocalVar()) {
2314 // The call returns arguments.
2315 assert(call_ptn->edge_count() > 0, "sanity");
2316 if (!call_analyzer->is_return_local()) {
2317 // Returns also unknown object.
2318 add_edge(call_ptn, phantom_obj);
2319 }
2320 }
2321 break;
2322 }
2323 }
2324 default: {
2325 // Fall-through here if not a Java method or no analyzer information
2326 // or some other type of call, assume the worst case: all arguments
2327 // globally escape.
2328 const TypeTuple* d = call->tf()->domain();
2329 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
2330 const Type* at = d->field_at(i);
2331 if (at->isa_oopptr() != nullptr) {
2332 Node* arg = call->in(i);
2333 if (arg->is_AddP()) {
2334 arg = get_addp_base(arg);
2335 }
2336 assert(ptnode_adr(arg->_idx) != nullptr, "should be defined already");
2337 set_escape_state(ptnode_adr(arg->_idx), PointsToNode::GlobalEscape NOT_PRODUCT(COMMA trace_arg_escape_message(call)));
2338 }
2339 }
2340 }
2341 }
2342 }
2343
2344
2345 // Finish Graph construction.
2346 bool ConnectionGraph::complete_connection_graph(
2347 GrowableArray<PointsToNode*>& ptnodes_worklist,
2348 GrowableArray<JavaObjectNode*>& non_escaped_allocs_worklist,
2349 GrowableArray<JavaObjectNode*>& java_objects_worklist,
2350 GrowableArray<FieldNode*>& oop_fields_worklist) {
2351 // Normally only 1-3 passes needed to build Connection Graph depending
2352 // on graph complexity. Observed 8 passes in jvm2008 compiler.compiler.
2353 // Set limit to 20 to catch situation when something did go wrong and
2354 // bailout Escape Analysis.
2355 // Also limit build time to 20 sec (60 in debug VM), EscapeAnalysisTimeout flag.
2356 #define GRAPH_BUILD_ITER_LIMIT 20
2357
2358 // Propagate GlobalEscape and ArgEscape escape states and check that
2359 // we still have non-escaping objects. The method pushs on _worklist
2360 // Field nodes which reference phantom_object.
2361 if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_allocs_worklist)) {
2362 return false; // Nothing to do.
2363 }
2364 // Now propagate references to all JavaObject nodes.
2365 int java_objects_length = java_objects_worklist.length();
2366 elapsedTimer build_time;
2367 build_time.start();
2368 elapsedTimer time;
2369 bool timeout = false;
2370 int new_edges = 1;
2371 int iterations = 0;
2372 do {
2373 while ((new_edges > 0) &&
2374 (iterations++ < GRAPH_BUILD_ITER_LIMIT)) {
2375 double start_time = time.seconds();
2376 time.start();
2377 new_edges = 0;
2378 // Propagate references to phantom_object for nodes pushed on _worklist
2379 // by find_non_escaped_objects() and find_field_value().
2380 new_edges += add_java_object_edges(phantom_obj, false);
2381 for (int next = 0; next < java_objects_length; ++next) {
2382 JavaObjectNode* ptn = java_objects_worklist.at(next);
2383 new_edges += add_java_object_edges(ptn, true);
2384
2385 #define SAMPLE_SIZE 4
2386 if ((next % SAMPLE_SIZE) == 0) {
2387 // Each 4 iterations calculate how much time it will take
2388 // to complete graph construction.
2389 time.stop();
2390 // Poll for requests from shutdown mechanism to quiesce compiler
2391 // because Connection graph construction may take long time.
2392 CompileBroker::maybe_block();
2393 double stop_time = time.seconds();
2394 double time_per_iter = (stop_time - start_time) / (double)SAMPLE_SIZE;
2395 double time_until_end = time_per_iter * (double)(java_objects_length - next);
2396 if ((start_time + time_until_end) >= EscapeAnalysisTimeout) {
2397 timeout = true;
2398 break; // Timeout
2399 }
2400 start_time = stop_time;
2401 time.start();
2402 }
2403 #undef SAMPLE_SIZE
2404
2405 }
2406 if (timeout) break;
2407 if (new_edges > 0) {
2408 // Update escape states on each iteration if graph was updated.
2409 if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_allocs_worklist)) {
2410 return false; // Nothing to do.
2411 }
2412 }
2413 time.stop();
2414 if (time.seconds() >= EscapeAnalysisTimeout) {
2415 timeout = true;
2416 break;
2417 }
2418 }
2419 if ((iterations < GRAPH_BUILD_ITER_LIMIT) && !timeout) {
2420 time.start();
2421 // Find fields which have unknown value.
2422 int fields_length = oop_fields_worklist.length();
2423 for (int next = 0; next < fields_length; next++) {
2424 FieldNode* field = oop_fields_worklist.at(next);
2425 if (field->edge_count() == 0) {
2426 new_edges += find_field_value(field);
2427 // This code may added new edges to phantom_object.
2428 // Need an other cycle to propagate references to phantom_object.
2429 }
2430 }
2431 time.stop();
2432 if (time.seconds() >= EscapeAnalysisTimeout) {
2433 timeout = true;
2434 break;
2435 }
2436 } else {
2437 new_edges = 0; // Bailout
2438 }
2439 } while (new_edges > 0);
2440
2441 build_time.stop();
2442 _build_time = build_time.seconds();
2443 _build_iterations = iterations;
2444
2445 // Bailout if passed limits.
2446 if ((iterations >= GRAPH_BUILD_ITER_LIMIT) || timeout) {
2447 Compile* C = _compile;
2448 if (C->log() != nullptr) {
2449 C->log()->begin_elem("connectionGraph_bailout reason='reached ");
2450 C->log()->text("%s", timeout ? "time" : "iterations");
2451 C->log()->end_elem(" limit'");
2452 }
2453 assert(ExitEscapeAnalysisOnTimeout, "infinite EA connection graph build during invocation %d (%f sec, %d iterations) with %d nodes and worklist size %d",
2454 _invocation, _build_time, _build_iterations, nodes_size(), ptnodes_worklist.length());
2455 // Possible infinite build_connection_graph loop,
2456 // bailout (no changes to ideal graph were made).
2457 return false;
2458 }
2459
2460 #undef GRAPH_BUILD_ITER_LIMIT
2461
2462 // Find fields initialized by null for non-escaping Allocations.
2463 int non_escaped_length = non_escaped_allocs_worklist.length();
2464 for (int next = 0; next < non_escaped_length; next++) {
2465 JavaObjectNode* ptn = non_escaped_allocs_worklist.at(next);
2466 PointsToNode::EscapeState es = ptn->escape_state();
2467 assert(es <= PointsToNode::ArgEscape, "sanity");
2468 if (es == PointsToNode::NoEscape) {
2469 if (find_init_values_null(ptn, _igvn) > 0) {
2470 // Adding references to null object does not change escape states
2471 // since it does not escape. Also no fields are added to null object.
2472 add_java_object_edges(null_obj, false);
2473 }
2474 }
2475 Node* n = ptn->ideal_node();
2476 if (n->is_Allocate()) {
2477 // The object allocated by this Allocate node will never be
2478 // seen by an other thread. Mark it so that when it is
2479 // expanded no MemBarStoreStore is added.
2480 InitializeNode* ini = n->as_Allocate()->initialization();
2481 if (ini != nullptr)
2482 ini->set_does_not_escape();
2483 }
2484 }
2485 return true; // Finished graph construction.
2486 }
2487
2488 // Propagate GlobalEscape and ArgEscape escape states to all nodes
2489 // and check that we still have non-escaping java objects.
2490 bool ConnectionGraph::find_non_escaped_objects(GrowableArray<PointsToNode*>& ptnodes_worklist,
2491 GrowableArray<JavaObjectNode*>& non_escaped_allocs_worklist) {
2492 GrowableArray<PointsToNode*> escape_worklist;
2493 // First, put all nodes with GlobalEscape and ArgEscape states on worklist.
2494 int ptnodes_length = ptnodes_worklist.length();
2495 for (int next = 0; next < ptnodes_length; ++next) {
2496 PointsToNode* ptn = ptnodes_worklist.at(next);
2497 if (ptn->escape_state() >= PointsToNode::ArgEscape ||
2498 ptn->fields_escape_state() >= PointsToNode::ArgEscape) {
2499 escape_worklist.push(ptn);
2500 }
2501 }
2502 // Set escape states to referenced nodes (edges list).
2503 while (escape_worklist.length() > 0) {
2504 PointsToNode* ptn = escape_worklist.pop();
2505 PointsToNode::EscapeState es = ptn->escape_state();
2506 PointsToNode::EscapeState field_es = ptn->fields_escape_state();
2507 if (ptn->is_Field() && ptn->as_Field()->is_oop() &&
2508 es >= PointsToNode::ArgEscape) {
2509 // GlobalEscape or ArgEscape state of field means it has unknown value.
2510 if (add_edge(ptn, phantom_obj)) {
2511 // New edge was added
2512 add_field_uses_to_worklist(ptn->as_Field());
2513 }
2514 }
2515 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2516 PointsToNode* e = i.get();
2517 if (e->is_Arraycopy()) {
2518 assert(ptn->arraycopy_dst(), "sanity");
2519 // Propagate only fields escape state through arraycopy edge.
2520 if (e->fields_escape_state() < field_es) {
2521 set_fields_escape_state(e, field_es NOT_PRODUCT(COMMA trace_propagate_message(ptn)));
2522 escape_worklist.push(e);
2523 }
2524 } else if (es >= field_es) {
2525 // fields_escape_state is also set to 'es' if it is less than 'es'.
2526 if (e->escape_state() < es) {
2527 set_escape_state(e, es NOT_PRODUCT(COMMA trace_propagate_message(ptn)));
2528 escape_worklist.push(e);
2529 }
2530 } else {
2531 // Propagate field escape state.
2532 bool es_changed = false;
2533 if (e->fields_escape_state() < field_es) {
2534 set_fields_escape_state(e, field_es NOT_PRODUCT(COMMA trace_propagate_message(ptn)));
2535 es_changed = true;
2536 }
2537 if ((e->escape_state() < field_es) &&
2538 e->is_Field() && ptn->is_JavaObject() &&
2539 e->as_Field()->is_oop()) {
2540 // Change escape state of referenced fields.
2541 set_escape_state(e, field_es NOT_PRODUCT(COMMA trace_propagate_message(ptn)));
2542 es_changed = true;
2543 } else if (e->escape_state() < es) {
2544 set_escape_state(e, es NOT_PRODUCT(COMMA trace_propagate_message(ptn)));
2545 es_changed = true;
2546 }
2547 if (es_changed) {
2548 escape_worklist.push(e);
2549 }
2550 }
2551 }
2552 }
2553 // Remove escaped objects from non_escaped list.
2554 for (int next = non_escaped_allocs_worklist.length()-1; next >= 0 ; --next) {
2555 JavaObjectNode* ptn = non_escaped_allocs_worklist.at(next);
2556 if (ptn->escape_state() >= PointsToNode::GlobalEscape) {
2557 non_escaped_allocs_worklist.delete_at(next);
2558 }
2559 if (ptn->escape_state() == PointsToNode::NoEscape) {
2560 // Find fields in non-escaped allocations which have unknown value.
2561 find_init_values_phantom(ptn);
2562 }
2563 }
2564 return (non_escaped_allocs_worklist.length() > 0);
2565 }
2566
2567 // Add all references to JavaObject node by walking over all uses.
2568 int ConnectionGraph::add_java_object_edges(JavaObjectNode* jobj, bool populate_worklist) {
2569 int new_edges = 0;
2570 if (populate_worklist) {
2571 // Populate _worklist by uses of jobj's uses.
2572 for (UseIterator i(jobj); i.has_next(); i.next()) {
2573 PointsToNode* use = i.get();
2574 if (use->is_Arraycopy()) {
2575 continue;
2576 }
2577 add_uses_to_worklist(use);
2578 if (use->is_Field() && use->as_Field()->is_oop()) {
2579 // Put on worklist all field's uses (loads) and
2580 // related field nodes (same base and offset).
2581 add_field_uses_to_worklist(use->as_Field());
2582 }
2583 }
2584 }
2585 for (int l = 0; l < _worklist.length(); l++) {
2586 PointsToNode* use = _worklist.at(l);
2587 if (PointsToNode::is_base_use(use)) {
2588 // Add reference from jobj to field and from field to jobj (field's base).
2589 use = PointsToNode::get_use_node(use)->as_Field();
2590 if (add_base(use->as_Field(), jobj)) {
2591 new_edges++;
2592 }
2593 continue;
2594 }
2595 assert(!use->is_JavaObject(), "sanity");
2596 if (use->is_Arraycopy()) {
2597 if (jobj == null_obj) { // null object does not have field edges
2598 continue;
2599 }
2600 // Added edge from Arraycopy node to arraycopy's source java object
2601 if (add_edge(use, jobj)) {
2602 jobj->set_arraycopy_src();
2603 new_edges++;
2604 }
2605 // and stop here.
2606 continue;
2607 }
2608 if (!add_edge(use, jobj)) {
2609 continue; // No new edge added, there was such edge already.
2610 }
2611 new_edges++;
2612 if (use->is_LocalVar()) {
2613 add_uses_to_worklist(use);
2614 if (use->arraycopy_dst()) {
2615 for (EdgeIterator i(use); i.has_next(); i.next()) {
2616 PointsToNode* e = i.get();
2617 if (e->is_Arraycopy()) {
2618 if (jobj == null_obj) { // null object does not have field edges
2619 continue;
2620 }
2621 // Add edge from arraycopy's destination java object to Arraycopy node.
2622 if (add_edge(jobj, e)) {
2623 new_edges++;
2624 jobj->set_arraycopy_dst();
2625 }
2626 }
2627 }
2628 }
2629 } else {
2630 // Added new edge to stored in field values.
2631 // Put on worklist all field's uses (loads) and
2632 // related field nodes (same base and offset).
2633 add_field_uses_to_worklist(use->as_Field());
2634 }
2635 }
2636 _worklist.clear();
2637 _in_worklist.reset();
2638 return new_edges;
2639 }
2640
2641 // Put on worklist all related field nodes.
2642 void ConnectionGraph::add_field_uses_to_worklist(FieldNode* field) {
2643 assert(field->is_oop(), "sanity");
2644 int offset = field->offset();
2645 add_uses_to_worklist(field);
2646 // Loop over all bases of this field and push on worklist Field nodes
2647 // with the same offset and base (since they may reference the same field).
2648 for (BaseIterator i(field); i.has_next(); i.next()) {
2649 PointsToNode* base = i.get();
2650 add_fields_to_worklist(field, base);
2651 // Check if the base was source object of arraycopy and go over arraycopy's
2652 // destination objects since values stored to a field of source object are
2653 // accessible by uses (loads) of fields of destination objects.
2654 if (base->arraycopy_src()) {
2655 for (UseIterator j(base); j.has_next(); j.next()) {
2656 PointsToNode* arycp = j.get();
2657 if (arycp->is_Arraycopy()) {
2658 for (UseIterator k(arycp); k.has_next(); k.next()) {
2659 PointsToNode* abase = k.get();
2660 if (abase->arraycopy_dst() && abase != base) {
2661 // Look for the same arraycopy reference.
2662 add_fields_to_worklist(field, abase);
2663 }
2664 }
2665 }
2666 }
2667 }
2668 }
2669 }
2670
2671 // Put on worklist all related field nodes.
2672 void ConnectionGraph::add_fields_to_worklist(FieldNode* field, PointsToNode* base) {
2673 int offset = field->offset();
2674 if (base->is_LocalVar()) {
2675 for (UseIterator j(base); j.has_next(); j.next()) {
2676 PointsToNode* f = j.get();
2677 if (PointsToNode::is_base_use(f)) { // Field
2678 f = PointsToNode::get_use_node(f);
2679 if (f == field || !f->as_Field()->is_oop()) {
2680 continue;
2681 }
2682 int offs = f->as_Field()->offset();
2683 if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
2684 add_to_worklist(f);
2685 }
2686 }
2687 }
2688 } else {
2689 assert(base->is_JavaObject(), "sanity");
2690 if (// Skip phantom_object since it is only used to indicate that
2691 // this field's content globally escapes.
2692 (base != phantom_obj) &&
2693 // null object node does not have fields.
2694 (base != null_obj)) {
2695 for (EdgeIterator i(base); i.has_next(); i.next()) {
2696 PointsToNode* f = i.get();
2697 // Skip arraycopy edge since store to destination object field
2698 // does not update value in source object field.
2699 if (f->is_Arraycopy()) {
2700 assert(base->arraycopy_dst(), "sanity");
2701 continue;
2702 }
2703 if (f == field || !f->as_Field()->is_oop()) {
2704 continue;
2705 }
2706 int offs = f->as_Field()->offset();
2707 if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
2708 add_to_worklist(f);
2709 }
2710 }
2711 }
2712 }
2713 }
2714
2715 // Find fields which have unknown value.
2716 int ConnectionGraph::find_field_value(FieldNode* field) {
2717 // Escaped fields should have init value already.
2718 assert(field->escape_state() == PointsToNode::NoEscape, "sanity");
2719 int new_edges = 0;
2720 for (BaseIterator i(field); i.has_next(); i.next()) {
2721 PointsToNode* base = i.get();
2722 if (base->is_JavaObject()) {
2723 // Skip Allocate's fields which will be processed later.
2724 if (base->ideal_node()->is_Allocate()) {
2725 return 0;
2726 }
2727 assert(base == null_obj, "only null ptr base expected here");
2728 }
2729 }
2730 if (add_edge(field, phantom_obj)) {
2731 // New edge was added
2732 new_edges++;
2733 add_field_uses_to_worklist(field);
2734 }
2735 return new_edges;
2736 }
2737
2738 // Find fields initializing values for allocations.
2739 int ConnectionGraph::find_init_values_phantom(JavaObjectNode* pta) {
2740 assert(pta->escape_state() == PointsToNode::NoEscape, "Not escaped Allocate nodes only");
2741 Node* alloc = pta->ideal_node();
2742
2743 // Do nothing for Allocate nodes since its fields values are
2744 // "known" unless they are initialized by arraycopy/clone.
2745 if (alloc->is_Allocate() && !pta->arraycopy_dst()) {
2746 return 0;
2747 }
2748 assert(pta->arraycopy_dst() || alloc->as_CallStaticJava(), "sanity");
2749 #ifdef ASSERT
2750 if (!pta->arraycopy_dst() && alloc->as_CallStaticJava()->method() == nullptr) {
2751 const char* name = alloc->as_CallStaticJava()->_name;
2752 assert(strncmp(name, "C2 Runtime multianewarray", 25) == 0, "sanity");
2753 }
2754 #endif
2755 // Non-escaped allocation returned from Java or runtime call have unknown values in fields.
2756 int new_edges = 0;
2757 for (EdgeIterator i(pta); i.has_next(); i.next()) {
2758 PointsToNode* field = i.get();
2759 if (field->is_Field() && field->as_Field()->is_oop()) {
2760 if (add_edge(field, phantom_obj)) {
2761 // New edge was added
2762 new_edges++;
2763 add_field_uses_to_worklist(field->as_Field());
2764 }
2765 }
2766 }
2767 return new_edges;
2768 }
2769
2770 // Find fields initializing values for allocations.
2771 int ConnectionGraph::find_init_values_null(JavaObjectNode* pta, PhaseValues* phase) {
2772 assert(pta->escape_state() == PointsToNode::NoEscape, "Not escaped Allocate nodes only");
2773 Node* alloc = pta->ideal_node();
2774 // Do nothing for Call nodes since its fields values are unknown.
2775 if (!alloc->is_Allocate()) {
2776 return 0;
2777 }
2778 InitializeNode* ini = alloc->as_Allocate()->initialization();
2779 bool visited_bottom_offset = false;
2780 GrowableArray<int> offsets_worklist;
2781 int new_edges = 0;
2782
2783 // Check if an oop field's initializing value is recorded and add
2784 // a corresponding null if field's value if it is not recorded.
2785 // Connection Graph does not record a default initialization by null
2786 // captured by Initialize node.
2787 //
2788 for (EdgeIterator i(pta); i.has_next(); i.next()) {
2789 PointsToNode* field = i.get(); // Field (AddP)
2790 if (!field->is_Field() || !field->as_Field()->is_oop()) {
2791 continue; // Not oop field
2792 }
2793 int offset = field->as_Field()->offset();
2794 if (offset == Type::OffsetBot) {
2795 if (!visited_bottom_offset) {
2796 // OffsetBot is used to reference array's element,
2797 // always add reference to null to all Field nodes since we don't
2798 // known which element is referenced.
2799 if (add_edge(field, null_obj)) {
2800 // New edge was added
2801 new_edges++;
2802 add_field_uses_to_worklist(field->as_Field());
2803 visited_bottom_offset = true;
2804 }
2805 }
2806 } else {
2807 // Check only oop fields.
2808 const Type* adr_type = field->ideal_node()->as_AddP()->bottom_type();
2809 if (adr_type->isa_rawptr()) {
2810 #ifdef ASSERT
2811 // Raw pointers are used for initializing stores so skip it
2812 // since it should be recorded already
2813 Node* base = get_addp_base(field->ideal_node());
2814 assert(adr_type->isa_rawptr() && is_captured_store_address(field->ideal_node()), "unexpected pointer type");
2815 #endif
2816 continue;
2817 }
2818 if (!offsets_worklist.contains(offset)) {
2819 offsets_worklist.append(offset);
2820 Node* value = nullptr;
2821 if (ini != nullptr) {
2822 // StoreP::memory_type() == T_ADDRESS
2823 BasicType ft = UseCompressedOops ? T_NARROWOOP : T_ADDRESS;
2824 Node* store = ini->find_captured_store(offset, type2aelembytes(ft, true), phase);
2825 // Make sure initializing store has the same type as this AddP.
2826 // This AddP may reference non existing field because it is on a
2827 // dead branch of bimorphic call which is not eliminated yet.
2828 if (store != nullptr && store->is_Store() &&
2829 store->as_Store()->memory_type() == ft) {
2830 value = store->in(MemNode::ValueIn);
2831 #ifdef ASSERT
2832 if (VerifyConnectionGraph) {
2833 // Verify that AddP already points to all objects the value points to.
2834 PointsToNode* val = ptnode_adr(value->_idx);
2835 assert((val != nullptr), "should be processed already");
2836 PointsToNode* missed_obj = nullptr;
2837 if (val->is_JavaObject()) {
2838 if (!field->points_to(val->as_JavaObject())) {
2839 missed_obj = val;
2840 }
2841 } else {
2842 if (!val->is_LocalVar() || (val->edge_count() == 0)) {
2843 tty->print_cr("----------init store has invalid value -----");
2844 store->dump();
2845 val->dump();
2846 assert(val->is_LocalVar() && (val->edge_count() > 0), "should be processed already");
2847 }
2848 for (EdgeIterator j(val); j.has_next(); j.next()) {
2849 PointsToNode* obj = j.get();
2850 if (obj->is_JavaObject()) {
2851 if (!field->points_to(obj->as_JavaObject())) {
2852 missed_obj = obj;
2853 break;
2854 }
2855 }
2856 }
2857 }
2858 if (missed_obj != nullptr) {
2859 tty->print_cr("----------field---------------------------------");
2860 field->dump();
2861 tty->print_cr("----------missed referernce to object-----------");
2862 missed_obj->dump();
2863 tty->print_cr("----------object referernced by init store -----");
2864 store->dump();
2865 val->dump();
2866 assert(!field->points_to(missed_obj->as_JavaObject()), "missed JavaObject reference");
2867 }
2868 }
2869 #endif
2870 } else {
2871 // There could be initializing stores which follow allocation.
2872 // For example, a volatile field store is not collected
2873 // by Initialize node.
2874 //
2875 // Need to check for dependent loads to separate such stores from
2876 // stores which follow loads. For now, add initial value null so
2877 // that compare pointers optimization works correctly.
2878 }
2879 }
2880 if (value == nullptr) {
2881 // A field's initializing value was not recorded. Add null.
2882 if (add_edge(field, null_obj)) {
2883 // New edge was added
2884 new_edges++;
2885 add_field_uses_to_worklist(field->as_Field());
2886 }
2887 }
2888 }
2889 }
2890 }
2891 return new_edges;
2892 }
2893
2894 // Adjust scalar_replaceable state after Connection Graph is built.
2895 void ConnectionGraph::adjust_scalar_replaceable_state(JavaObjectNode* jobj, Unique_Node_List &reducible_merges) {
2896 // A Phi 'x' is a _candidate_ to be reducible if 'can_reduce_phi(x)'
2897 // returns true. If one of the constraints in this method set 'jobj' to NSR
2898 // then the candidate Phi is discarded. If the Phi has another SR 'jobj' as
2899 // input, 'adjust_scalar_replaceable_state' will eventually be called with
2900 // that other object and the Phi will become a reducible Phi.
2901 // There could be multiple merges involving the same jobj.
2902 Unique_Node_List candidates;
2903
2904 // Search for non-escaping objects which are not scalar replaceable
2905 // and mark them to propagate the state to referenced objects.
2906
2907 for (UseIterator i(jobj); i.has_next(); i.next()) {
2908 PointsToNode* use = i.get();
2909 if (use->is_Arraycopy()) {
2910 continue;
2911 }
2912 if (use->is_Field()) {
2913 FieldNode* field = use->as_Field();
2914 assert(field->is_oop() && field->scalar_replaceable(), "sanity");
2915 // 1. An object is not scalar replaceable if the field into which it is
2916 // stored has unknown offset (stored into unknown element of an array).
2917 if (field->offset() == Type::OffsetBot) {
2918 set_not_scalar_replaceable(jobj NOT_PRODUCT(COMMA "is stored at unknown offset"));
2919 return;
2920 }
2921 for (BaseIterator i(field); i.has_next(); i.next()) {
2922 PointsToNode* base = i.get();
2923 // 2. An object is not scalar replaceable if the field into which it is
2924 // stored has multiple bases one of which is null.
2925 if ((base == null_obj) && (field->base_count() > 1)) {
2926 set_not_scalar_replaceable(jobj NOT_PRODUCT(COMMA "is stored into field with potentially null base"));
2927 return;
2928 }
2929 // 2.5. An object is not scalar replaceable if the field into which it is
2930 // stored has NSR base.
2931 if (!base->scalar_replaceable()) {
2932 set_not_scalar_replaceable(jobj NOT_PRODUCT(COMMA "is stored into field with NSR base"));
2933 return;
2934 }
2935 }
2936 }
2937 assert(use->is_Field() || use->is_LocalVar(), "sanity");
2938 // 3. An object is not scalar replaceable if it is merged with other objects
2939 // and we can't remove the merge
2940 for (EdgeIterator j(use); j.has_next(); j.next()) {
2941 PointsToNode* ptn = j.get();
2942 if (ptn->is_JavaObject() && ptn != jobj) {
2943 Node* use_n = use->ideal_node();
2944
2945 // These other local vars may point to multiple objects through a Phi
2946 // In this case we skip them and see if we can reduce the Phi.
2947 if (use_n->is_CastPP() || use_n->is_CheckCastPP()) {
2948 use_n = use_n->in(1);
2949 }
2950
2951 // If it's already a candidate or confirmed reducible merge we can skip verification
2952 if (candidates.member(use_n) || reducible_merges.member(use_n)) {
2953 continue;
2954 }
2955
2956 if (use_n->is_Phi() && can_reduce_phi(use_n->as_Phi())) {
2957 candidates.push(use_n);
2958 } else {
2959 // Mark all objects as NSR if we can't remove the merge
2960 set_not_scalar_replaceable(jobj NOT_PRODUCT(COMMA trace_merged_message(ptn)));
2961 set_not_scalar_replaceable(ptn NOT_PRODUCT(COMMA trace_merged_message(jobj)));
2962 }
2963 }
2964 }
2965 if (!jobj->scalar_replaceable()) {
2966 return;
2967 }
2968 }
2969
2970 for (EdgeIterator j(jobj); j.has_next(); j.next()) {
2971 if (j.get()->is_Arraycopy()) {
2972 continue;
2973 }
2974
2975 // Non-escaping object node should point only to field nodes.
2976 FieldNode* field = j.get()->as_Field();
2977 int offset = field->as_Field()->offset();
2978
2979 // 4. An object is not scalar replaceable if it has a field with unknown
2980 // offset (array's element is accessed in loop).
2981 if (offset == Type::OffsetBot) {
2982 set_not_scalar_replaceable(jobj NOT_PRODUCT(COMMA "has field with unknown offset"));
2983 return;
2984 }
2985 // 5. Currently an object is not scalar replaceable if a LoadStore node
2986 // access its field since the field value is unknown after it.
2987 //
2988 Node* n = field->ideal_node();
2989
2990 // Test for an unsafe access that was parsed as maybe off heap
2991 // (with a CheckCastPP to raw memory).
2992 assert(n->is_AddP(), "expect an address computation");
2993 if (n->in(AddPNode::Base)->is_top() &&
2994 n->in(AddPNode::Address)->Opcode() == Op_CheckCastPP) {
2995 assert(n->in(AddPNode::Address)->bottom_type()->isa_rawptr(), "raw address so raw cast expected");
2996 assert(_igvn->type(n->in(AddPNode::Address)->in(1))->isa_oopptr(), "cast pattern at unsafe access expected");
2997 set_not_scalar_replaceable(jobj NOT_PRODUCT(COMMA "is used as base of mixed unsafe access"));
2998 return;
2999 }
3000
3001 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3002 Node* u = n->fast_out(i);
3003 if (u->is_LoadStore() || (u->is_Mem() && u->as_Mem()->is_mismatched_access())) {
3004 set_not_scalar_replaceable(jobj NOT_PRODUCT(COMMA "is used in LoadStore or mismatched access"));
3005 return;
3006 }
3007 }
3008
3009 // 6. Or the address may point to more then one object. This may produce
3010 // the false positive result (set not scalar replaceable)
3011 // since the flow-insensitive escape analysis can't separate
3012 // the case when stores overwrite the field's value from the case
3013 // when stores happened on different control branches.
3014 //
3015 // Note: it will disable scalar replacement in some cases:
3016 //
3017 // Point p[] = new Point[1];
3018 // p[0] = new Point(); // Will be not scalar replaced
3019 //
3020 // but it will save us from incorrect optimizations in next cases:
3021 //
3022 // Point p[] = new Point[1];
3023 // if ( x ) p[0] = new Point(); // Will be not scalar replaced
3024 //
3025 if (field->base_count() > 1 && candidates.size() == 0) {
3026 if (has_non_reducible_merge(field, reducible_merges)) {
3027 for (BaseIterator i(field); i.has_next(); i.next()) {
3028 PointsToNode* base = i.get();
3029 // Don't take into account LocalVar nodes which
3030 // may point to only one object which should be also
3031 // this field's base by now.
3032 if (base->is_JavaObject() && base != jobj) {
3033 // Mark all bases.
3034 set_not_scalar_replaceable(jobj NOT_PRODUCT(COMMA "may point to more than one object"));
3035 set_not_scalar_replaceable(base NOT_PRODUCT(COMMA "may point to more than one object"));
3036 }
3037 }
3038
3039 if (!jobj->scalar_replaceable()) {
3040 return;
3041 }
3042 }
3043 }
3044 }
3045
3046 // The candidate is truly a reducible merge only if none of the other
3047 // constraints ruled it as NSR. There could be multiple merges involving the
3048 // same jobj.
3049 assert(jobj->scalar_replaceable(), "sanity");
3050 for (uint i = 0; i < candidates.size(); i++ ) {
3051 Node* candidate = candidates.at(i);
3052 reducible_merges.push(candidate);
3053 }
3054 }
3055
3056 bool ConnectionGraph::has_non_reducible_merge(FieldNode* field, Unique_Node_List& reducible_merges) {
3057 for (BaseIterator i(field); i.has_next(); i.next()) {
3058 Node* base = i.get()->ideal_node();
3059 if (base->is_Phi() && !reducible_merges.member(base)) {
3060 return true;
3061 }
3062 }
3063 return false;
3064 }
3065
3066 void ConnectionGraph::revisit_reducible_phi_status(JavaObjectNode* jobj, Unique_Node_List& reducible_merges) {
3067 assert(jobj != nullptr && !jobj->scalar_replaceable(), "jobj should be set as NSR before calling this function.");
3068
3069 // Look for 'phis' that refer to 'jobj' as the last
3070 // remaining scalar replaceable input.
3071 uint reducible_merges_cnt = reducible_merges.size();
3072 for (uint i = 0; i < reducible_merges_cnt; i++) {
3073 Node* phi = reducible_merges.at(i);
3074
3075 // This 'Phi' will be a 'good' if it still points to
3076 // at least one scalar replaceable object. Note that 'obj'
3077 // was/should be marked as NSR before calling this function.
3078 bool good_phi = false;
3079
3080 for (uint j = 1; j < phi->req(); j++) {
3081 JavaObjectNode* phi_in_obj = unique_java_object(phi->in(j));
3082 if (phi_in_obj != nullptr && phi_in_obj->scalar_replaceable()) {
3083 good_phi = true;
3084 break;
3085 }
3086 }
3087
3088 if (!good_phi) {
3089 NOT_PRODUCT(if (TraceReduceAllocationMerges) tty->print_cr("Phi %d became non-reducible after node %d became NSR.", phi->_idx, jobj->ideal_node()->_idx);)
3090 reducible_merges.remove(i);
3091
3092 // Decrement the index because the 'remove' call above actually
3093 // moves the last entry of the list to position 'i'.
3094 i--;
3095
3096 reducible_merges_cnt--;
3097 }
3098 }
3099 }
3100
3101 // Propagate NSR (Not scalar replaceable) state.
3102 void ConnectionGraph::find_scalar_replaceable_allocs(GrowableArray<JavaObjectNode*>& jobj_worklist, Unique_Node_List &reducible_merges) {
3103 int jobj_length = jobj_worklist.length();
3104 bool found_nsr_alloc = true;
3105 while (found_nsr_alloc) {
3106 found_nsr_alloc = false;
3107 for (int next = 0; next < jobj_length; ++next) {
3108 JavaObjectNode* jobj = jobj_worklist.at(next);
3109 for (UseIterator i(jobj); (jobj->scalar_replaceable() && i.has_next()); i.next()) {
3110 PointsToNode* use = i.get();
3111 if (use->is_Field()) {
3112 FieldNode* field = use->as_Field();
3113 assert(field->is_oop() && field->scalar_replaceable(), "sanity");
3114 assert(field->offset() != Type::OffsetBot, "sanity");
3115 for (BaseIterator i(field); i.has_next(); i.next()) {
3116 PointsToNode* base = i.get();
3117 // An object is not scalar replaceable if the field into which
3118 // it is stored has NSR base.
3119 if ((base != null_obj) && !base->scalar_replaceable()) {
3120 set_not_scalar_replaceable(jobj NOT_PRODUCT(COMMA "is stored into field with NSR base"));
3121 // Any merge that had only 'jobj' as scalar-replaceable will now be non-reducible,
3122 // because there is no point in reducing a Phi that won't improve the number of SR
3123 // objects.
3124 revisit_reducible_phi_status(jobj, reducible_merges);
3125 found_nsr_alloc = true;
3126 break;
3127 }
3128 }
3129 }
3130 }
3131 }
3132 }
3133 }
3134
3135 #ifdef ASSERT
3136 void ConnectionGraph::verify_connection_graph(
3137 GrowableArray<PointsToNode*>& ptnodes_worklist,
3138 GrowableArray<JavaObjectNode*>& non_escaped_allocs_worklist,
3139 GrowableArray<JavaObjectNode*>& java_objects_worklist,
3140 GrowableArray<Node*>& addp_worklist) {
3141 // Verify that graph is complete - no new edges could be added.
3142 int java_objects_length = java_objects_worklist.length();
3143 int non_escaped_length = non_escaped_allocs_worklist.length();
3144 int new_edges = 0;
3145 for (int next = 0; next < java_objects_length; ++next) {
3146 JavaObjectNode* ptn = java_objects_worklist.at(next);
3147 new_edges += add_java_object_edges(ptn, true);
3148 }
3149 assert(new_edges == 0, "graph was not complete");
3150 // Verify that escape state is final.
3151 int length = non_escaped_allocs_worklist.length();
3152 find_non_escaped_objects(ptnodes_worklist, non_escaped_allocs_worklist);
3153 assert((non_escaped_length == non_escaped_allocs_worklist.length()) &&
3154 (non_escaped_length == length) &&
3155 (_worklist.length() == 0), "escape state was not final");
3156
3157 // Verify fields information.
3158 int addp_length = addp_worklist.length();
3159 for (int next = 0; next < addp_length; ++next ) {
3160 Node* n = addp_worklist.at(next);
3161 FieldNode* field = ptnode_adr(n->_idx)->as_Field();
3162 if (field->is_oop()) {
3163 // Verify that field has all bases
3164 Node* base = get_addp_base(n);
3165 PointsToNode* ptn = ptnode_adr(base->_idx);
3166 if (ptn->is_JavaObject()) {
3167 assert(field->has_base(ptn->as_JavaObject()), "sanity");
3168 } else {
3169 assert(ptn->is_LocalVar(), "sanity");
3170 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
3171 PointsToNode* e = i.get();
3172 if (e->is_JavaObject()) {
3173 assert(field->has_base(e->as_JavaObject()), "sanity");
3174 }
3175 }
3176 }
3177 // Verify that all fields have initializing values.
3178 if (field->edge_count() == 0) {
3179 tty->print_cr("----------field does not have references----------");
3180 field->dump();
3181 for (BaseIterator i(field); i.has_next(); i.next()) {
3182 PointsToNode* base = i.get();
3183 tty->print_cr("----------field has next base---------------------");
3184 base->dump();
3185 if (base->is_JavaObject() && (base != phantom_obj) && (base != null_obj)) {
3186 tty->print_cr("----------base has fields-------------------------");
3187 for (EdgeIterator j(base); j.has_next(); j.next()) {
3188 j.get()->dump();
3189 }
3190 tty->print_cr("----------base has references---------------------");
3191 for (UseIterator j(base); j.has_next(); j.next()) {
3192 j.get()->dump();
3193 }
3194 }
3195 }
3196 for (UseIterator i(field); i.has_next(); i.next()) {
3197 i.get()->dump();
3198 }
3199 assert(field->edge_count() > 0, "sanity");
3200 }
3201 }
3202 }
3203 }
3204 #endif
3205
3206 // Optimize ideal graph.
3207 void ConnectionGraph::optimize_ideal_graph(GrowableArray<Node*>& ptr_cmp_worklist,
3208 GrowableArray<MemBarStoreStoreNode*>& storestore_worklist) {
3209 Compile* C = _compile;
3210 PhaseIterGVN* igvn = _igvn;
3211 if (EliminateLocks) {
3212 // Mark locks before changing ideal graph.
3213 int cnt = C->macro_count();
3214 for (int i = 0; i < cnt; i++) {
3215 Node *n = C->macro_node(i);
3216 if (n->is_AbstractLock()) { // Lock and Unlock nodes
3217 AbstractLockNode* alock = n->as_AbstractLock();
3218 if (!alock->is_non_esc_obj()) {
3219 if (can_eliminate_lock(alock)) {
3220 assert(!alock->is_eliminated() || alock->is_coarsened(), "sanity");
3221 // The lock could be marked eliminated by lock coarsening
3222 // code during first IGVN before EA. Replace coarsened flag
3223 // to eliminate all associated locks/unlocks.
3224 #ifdef ASSERT
3225 alock->log_lock_optimization(C, "eliminate_lock_set_non_esc3");
3226 #endif
3227 alock->set_non_esc_obj();
3228 }
3229 }
3230 }
3231 }
3232 }
3233
3234 if (OptimizePtrCompare) {
3235 for (int i = 0; i < ptr_cmp_worklist.length(); i++) {
3236 Node *n = ptr_cmp_worklist.at(i);
3237 assert(n->Opcode() == Op_CmpN || n->Opcode() == Op_CmpP, "must be");
3238 const TypeInt* tcmp = optimize_ptr_compare(n->in(1), n->in(2));
3239 if (tcmp->singleton()) {
3240 Node* cmp = igvn->makecon(tcmp);
3241 #ifndef PRODUCT
3242 if (PrintOptimizePtrCompare) {
3243 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, (tcmp == TypeInt::CC_EQ ? "EQ" : "NotEQ"));
3244 if (Verbose) {
3245 n->dump(1);
3246 }
3247 }
3248 #endif
3249 igvn->replace_node(n, cmp);
3250 }
3251 }
3252 }
3253
3254 // For MemBarStoreStore nodes added in library_call.cpp, check
3255 // escape status of associated AllocateNode and optimize out
3256 // MemBarStoreStore node if the allocated object never escapes.
3257 for (int i = 0; i < storestore_worklist.length(); i++) {
3258 Node* storestore = storestore_worklist.at(i);
3259 Node* alloc = storestore->in(MemBarNode::Precedent)->in(0);
3260 if (alloc->is_Allocate() && not_global_escape(alloc)) {
3261 MemBarNode* mb = MemBarNode::make(C, Op_MemBarCPUOrder, Compile::AliasIdxBot);
3262 mb->init_req(TypeFunc::Memory, storestore->in(TypeFunc::Memory));
3263 mb->init_req(TypeFunc::Control, storestore->in(TypeFunc::Control));
3264 igvn->register_new_node_with_optimizer(mb);
3265 igvn->replace_node(storestore, mb);
3266 }
3267 }
3268 }
3269
3270 // Optimize objects compare.
3271 const TypeInt* ConnectionGraph::optimize_ptr_compare(Node* left, Node* right) {
3272 assert(OptimizePtrCompare, "sanity");
3273 const TypeInt* EQ = TypeInt::CC_EQ; // [0] == ZERO
3274 const TypeInt* NE = TypeInt::CC_GT; // [1] == ONE
3275 const TypeInt* UNKNOWN = TypeInt::CC; // [-1, 0,1]
3276
3277 PointsToNode* ptn1 = ptnode_adr(left->_idx);
3278 PointsToNode* ptn2 = ptnode_adr(right->_idx);
3279 JavaObjectNode* jobj1 = unique_java_object(left);
3280 JavaObjectNode* jobj2 = unique_java_object(right);
3281
3282 // The use of this method during allocation merge reduction may cause 'left'
3283 // or 'right' be something (e.g., a Phi) that isn't in the connection graph or
3284 // that doesn't reference an unique java object.
3285 if (ptn1 == nullptr || ptn2 == nullptr ||
3286 jobj1 == nullptr || jobj2 == nullptr) {
3287 return UNKNOWN;
3288 }
3289
3290 assert(ptn1->is_JavaObject() || ptn1->is_LocalVar(), "sanity");
3291 assert(ptn2->is_JavaObject() || ptn2->is_LocalVar(), "sanity");
3292
3293 // Check simple cases first.
3294 if (jobj1 != nullptr) {
3295 if (jobj1->escape_state() == PointsToNode::NoEscape) {
3296 if (jobj1 == jobj2) {
3297 // Comparing the same not escaping object.
3298 return EQ;
3299 }
3300 Node* obj = jobj1->ideal_node();
3301 // Comparing not escaping allocation.
3302 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
3303 !ptn2->points_to(jobj1)) {
3304 return NE; // This includes nullness check.
3305 }
3306 }
3307 }
3308 if (jobj2 != nullptr) {
3309 if (jobj2->escape_state() == PointsToNode::NoEscape) {
3310 Node* obj = jobj2->ideal_node();
3311 // Comparing not escaping allocation.
3312 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
3313 !ptn1->points_to(jobj2)) {
3314 return NE; // This includes nullness check.
3315 }
3316 }
3317 }
3318 if (jobj1 != nullptr && jobj1 != phantom_obj &&
3319 jobj2 != nullptr && jobj2 != phantom_obj &&
3320 jobj1->ideal_node()->is_Con() &&
3321 jobj2->ideal_node()->is_Con()) {
3322 // Klass or String constants compare. Need to be careful with
3323 // compressed pointers - compare types of ConN and ConP instead of nodes.
3324 const Type* t1 = jobj1->ideal_node()->get_ptr_type();
3325 const Type* t2 = jobj2->ideal_node()->get_ptr_type();
3326 if (t1->make_ptr() == t2->make_ptr()) {
3327 return EQ;
3328 } else {
3329 return NE;
3330 }
3331 }
3332 if (ptn1->meet(ptn2)) {
3333 return UNKNOWN; // Sets are not disjoint
3334 }
3335
3336 // Sets are disjoint.
3337 bool set1_has_unknown_ptr = ptn1->points_to(phantom_obj);
3338 bool set2_has_unknown_ptr = ptn2->points_to(phantom_obj);
3339 bool set1_has_null_ptr = ptn1->points_to(null_obj);
3340 bool set2_has_null_ptr = ptn2->points_to(null_obj);
3341 if ((set1_has_unknown_ptr && set2_has_null_ptr) ||
3342 (set2_has_unknown_ptr && set1_has_null_ptr)) {
3343 // Check nullness of unknown object.
3344 return UNKNOWN;
3345 }
3346
3347 // Disjointness by itself is not sufficient since
3348 // alias analysis is not complete for escaped objects.
3349 // Disjoint sets are definitely unrelated only when
3350 // at least one set has only not escaping allocations.
3351 if (!set1_has_unknown_ptr && !set1_has_null_ptr) {
3352 if (ptn1->non_escaping_allocation()) {
3353 return NE;
3354 }
3355 }
3356 if (!set2_has_unknown_ptr && !set2_has_null_ptr) {
3357 if (ptn2->non_escaping_allocation()) {
3358 return NE;
3359 }
3360 }
3361 return UNKNOWN;
3362 }
3363
3364 // Connection Graph construction functions.
3365
3366 void ConnectionGraph::add_local_var(Node *n, PointsToNode::EscapeState es) {
3367 PointsToNode* ptadr = _nodes.at(n->_idx);
3368 if (ptadr != nullptr) {
3369 assert(ptadr->is_LocalVar() && ptadr->ideal_node() == n, "sanity");
3370 return;
3371 }
3372 Compile* C = _compile;
3373 ptadr = new (C->comp_arena()) LocalVarNode(this, n, es);
3374 map_ideal_node(n, ptadr);
3375 }
3376
3377 PointsToNode* ConnectionGraph::add_java_object(Node *n, PointsToNode::EscapeState es) {
3378 PointsToNode* ptadr = _nodes.at(n->_idx);
3379 if (ptadr != nullptr) {
3380 assert(ptadr->is_JavaObject() && ptadr->ideal_node() == n, "sanity");
3381 return ptadr;
3382 }
3383 Compile* C = _compile;
3384 ptadr = new (C->comp_arena()) JavaObjectNode(this, n, es);
3385 map_ideal_node(n, ptadr);
3386 return ptadr;
3387 }
3388
3389 void ConnectionGraph::add_field(Node *n, PointsToNode::EscapeState es, int offset) {
3390 PointsToNode* ptadr = _nodes.at(n->_idx);
3391 if (ptadr != nullptr) {
3392 assert(ptadr->is_Field() && ptadr->ideal_node() == n, "sanity");
3393 return;
3394 }
3395 bool unsafe = false;
3396 bool is_oop = is_oop_field(n, offset, &unsafe);
3397 if (unsafe) {
3398 es = PointsToNode::GlobalEscape;
3399 }
3400 Compile* C = _compile;
3401 FieldNode* field = new (C->comp_arena()) FieldNode(this, n, es, offset, is_oop);
3402 map_ideal_node(n, field);
3403 }
3404
3405 void ConnectionGraph::add_arraycopy(Node *n, PointsToNode::EscapeState es,
3406 PointsToNode* src, PointsToNode* dst) {
3407 assert(!src->is_Field() && !dst->is_Field(), "only for JavaObject and LocalVar");
3408 assert((src != null_obj) && (dst != null_obj), "not for ConP null");
3409 PointsToNode* ptadr = _nodes.at(n->_idx);
3410 if (ptadr != nullptr) {
3411 assert(ptadr->is_Arraycopy() && ptadr->ideal_node() == n, "sanity");
3412 return;
3413 }
3414 Compile* C = _compile;
3415 ptadr = new (C->comp_arena()) ArraycopyNode(this, n, es);
3416 map_ideal_node(n, ptadr);
3417 // Add edge from arraycopy node to source object.
3418 (void)add_edge(ptadr, src);
3419 src->set_arraycopy_src();
3420 // Add edge from destination object to arraycopy node.
3421 (void)add_edge(dst, ptadr);
3422 dst->set_arraycopy_dst();
3423 }
3424
3425 bool ConnectionGraph::is_oop_field(Node* n, int offset, bool* unsafe) {
3426 const Type* adr_type = n->as_AddP()->bottom_type();
3427 BasicType bt = T_INT;
3428 if (offset == Type::OffsetBot) {
3429 // Check only oop fields.
3430 if (!adr_type->isa_aryptr() ||
3431 adr_type->isa_aryptr()->elem() == Type::BOTTOM ||
3432 adr_type->isa_aryptr()->elem()->make_oopptr() != nullptr) {
3433 // OffsetBot is used to reference array's element. Ignore first AddP.
3434 if (find_second_addp(n, n->in(AddPNode::Base)) == nullptr) {
3435 bt = T_OBJECT;
3436 }
3437 }
3438 } else if (offset != Type::klass_offset()) {
3439 if (adr_type->isa_instptr()) {
3440 ciField* field = _compile->alias_type(adr_type->isa_instptr())->field();
3441 if (field != nullptr) {
3442 bt = field->layout_type();
3443 } else {
3444 // Check for unsafe oop field access
3445 if (n->has_out_with(Op_StoreP, Op_LoadP, Op_StoreN, Op_LoadN) ||
3446 n->has_out_with(Op_GetAndSetP, Op_GetAndSetN, Op_CompareAndExchangeP, Op_CompareAndExchangeN) ||
3447 n->has_out_with(Op_CompareAndSwapP, Op_CompareAndSwapN, Op_WeakCompareAndSwapP, Op_WeakCompareAndSwapN) ||
3448 BarrierSet::barrier_set()->barrier_set_c2()->escape_has_out_with_unsafe_object(n)) {
3449 bt = T_OBJECT;
3450 (*unsafe) = true;
3451 }
3452 }
3453 } else if (adr_type->isa_aryptr()) {
3454 if (offset == arrayOopDesc::length_offset_in_bytes()) {
3455 // Ignore array length load.
3456 } else if (find_second_addp(n, n->in(AddPNode::Base)) != nullptr) {
3457 // Ignore first AddP.
3458 } else {
3459 const Type* elemtype = adr_type->isa_aryptr()->elem();
3460 bt = elemtype->array_element_basic_type();
3461 }
3462 } else if (adr_type->isa_rawptr() || adr_type->isa_klassptr()) {
3463 // Allocation initialization, ThreadLocal field access, unsafe access
3464 if (n->has_out_with(Op_StoreP, Op_LoadP, Op_StoreN, Op_LoadN) ||
3465 n->has_out_with(Op_GetAndSetP, Op_GetAndSetN, Op_CompareAndExchangeP, Op_CompareAndExchangeN) ||
3466 n->has_out_with(Op_CompareAndSwapP, Op_CompareAndSwapN, Op_WeakCompareAndSwapP, Op_WeakCompareAndSwapN) ||
3467 BarrierSet::barrier_set()->barrier_set_c2()->escape_has_out_with_unsafe_object(n)) {
3468 bt = T_OBJECT;
3469 }
3470 }
3471 }
3472 // Note: T_NARROWOOP is not classed as a real reference type
3473 return (is_reference_type(bt) || bt == T_NARROWOOP);
3474 }
3475
3476 // Returns unique pointed java object or null.
3477 JavaObjectNode* ConnectionGraph::unique_java_object(Node *n) const {
3478 // If the node was created after the escape computation we can't answer.
3479 uint idx = n->_idx;
3480 if (idx >= nodes_size()) {
3481 return nullptr;
3482 }
3483 PointsToNode* ptn = ptnode_adr(idx);
3484 if (ptn == nullptr) {
3485 return nullptr;
3486 }
3487 if (ptn->is_JavaObject()) {
3488 return ptn->as_JavaObject();
3489 }
3490 assert(ptn->is_LocalVar(), "sanity");
3491 // Check all java objects it points to.
3492 JavaObjectNode* jobj = nullptr;
3493 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
3494 PointsToNode* e = i.get();
3495 if (e->is_JavaObject()) {
3496 if (jobj == nullptr) {
3497 jobj = e->as_JavaObject();
3498 } else if (jobj != e) {
3499 return nullptr;
3500 }
3501 }
3502 }
3503 return jobj;
3504 }
3505
3506 // Return true if this node points only to non-escaping allocations.
3507 bool PointsToNode::non_escaping_allocation() {
3508 if (is_JavaObject()) {
3509 Node* n = ideal_node();
3510 if (n->is_Allocate() || n->is_CallStaticJava()) {
3511 return (escape_state() == PointsToNode::NoEscape);
3512 } else {
3513 return false;
3514 }
3515 }
3516 assert(is_LocalVar(), "sanity");
3517 // Check all java objects it points to.
3518 for (EdgeIterator i(this); i.has_next(); i.next()) {
3519 PointsToNode* e = i.get();
3520 if (e->is_JavaObject()) {
3521 Node* n = e->ideal_node();
3522 if ((e->escape_state() != PointsToNode::NoEscape) ||
3523 !(n->is_Allocate() || n->is_CallStaticJava())) {
3524 return false;
3525 }
3526 }
3527 }
3528 return true;
3529 }
3530
3531 // Return true if we know the node does not escape globally.
3532 bool ConnectionGraph::not_global_escape(Node *n) {
3533 assert(!_collecting, "should not call during graph construction");
3534 // If the node was created after the escape computation we can't answer.
3535 uint idx = n->_idx;
3536 if (idx >= nodes_size()) {
3537 return false;
3538 }
3539 PointsToNode* ptn = ptnode_adr(idx);
3540 if (ptn == nullptr) {
3541 return false; // not in congraph (e.g. ConI)
3542 }
3543 PointsToNode::EscapeState es = ptn->escape_state();
3544 // If we have already computed a value, return it.
3545 if (es >= PointsToNode::GlobalEscape) {
3546 return false;
3547 }
3548 if (ptn->is_JavaObject()) {
3549 return true; // (es < PointsToNode::GlobalEscape);
3550 }
3551 assert(ptn->is_LocalVar(), "sanity");
3552 // Check all java objects it points to.
3553 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
3554 if (i.get()->escape_state() >= PointsToNode::GlobalEscape) {
3555 return false;
3556 }
3557 }
3558 return true;
3559 }
3560
3561 // Return true if locked object does not escape globally
3562 // and locked code region (identified by BoxLockNode) is balanced:
3563 // all compiled code paths have corresponding Lock/Unlock pairs.
3564 bool ConnectionGraph::can_eliminate_lock(AbstractLockNode* alock) {
3565 if (alock->is_balanced() && not_global_escape(alock->obj_node())) {
3566 if (EliminateNestedLocks) {
3567 // We can mark whole locking region as Local only when only
3568 // one object is used for locking.
3569 alock->box_node()->as_BoxLock()->set_local();
3570 }
3571 return true;
3572 }
3573 return false;
3574 }
3575
3576 // Helper functions
3577
3578 // Return true if this node points to specified node or nodes it points to.
3579 bool PointsToNode::points_to(JavaObjectNode* ptn) const {
3580 if (is_JavaObject()) {
3581 return (this == ptn);
3582 }
3583 assert(is_LocalVar() || is_Field(), "sanity");
3584 for (EdgeIterator i(this); i.has_next(); i.next()) {
3585 if (i.get() == ptn) {
3586 return true;
3587 }
3588 }
3589 return false;
3590 }
3591
3592 // Return true if one node points to an other.
3593 bool PointsToNode::meet(PointsToNode* ptn) {
3594 if (this == ptn) {
3595 return true;
3596 } else if (ptn->is_JavaObject()) {
3597 return this->points_to(ptn->as_JavaObject());
3598 } else if (this->is_JavaObject()) {
3599 return ptn->points_to(this->as_JavaObject());
3600 }
3601 assert(this->is_LocalVar() && ptn->is_LocalVar(), "sanity");
3602 int ptn_count = ptn->edge_count();
3603 for (EdgeIterator i(this); i.has_next(); i.next()) {
3604 PointsToNode* this_e = i.get();
3605 for (int j = 0; j < ptn_count; j++) {
3606 if (this_e == ptn->edge(j)) {
3607 return true;
3608 }
3609 }
3610 }
3611 return false;
3612 }
3613
3614 #ifdef ASSERT
3615 // Return true if bases point to this java object.
3616 bool FieldNode::has_base(JavaObjectNode* jobj) const {
3617 for (BaseIterator i(this); i.has_next(); i.next()) {
3618 if (i.get() == jobj) {
3619 return true;
3620 }
3621 }
3622 return false;
3623 }
3624 #endif
3625
3626 bool ConnectionGraph::is_captured_store_address(Node* addp) {
3627 // Handle simple case first.
3628 assert(_igvn->type(addp)->isa_oopptr() == nullptr, "should be raw access");
3629 if (addp->in(AddPNode::Address)->is_Proj() && addp->in(AddPNode::Address)->in(0)->is_Allocate()) {
3630 return true;
3631 } else if (addp->in(AddPNode::Address)->is_Phi()) {
3632 for (DUIterator_Fast imax, i = addp->fast_outs(imax); i < imax; i++) {
3633 Node* addp_use = addp->fast_out(i);
3634 if (addp_use->is_Store()) {
3635 for (DUIterator_Fast jmax, j = addp_use->fast_outs(jmax); j < jmax; j++) {
3636 if (addp_use->fast_out(j)->is_Initialize()) {
3637 return true;
3638 }
3639 }
3640 }
3641 }
3642 }
3643 return false;
3644 }
3645
3646 int ConnectionGraph::address_offset(Node* adr, PhaseValues* phase) {
3647 const Type *adr_type = phase->type(adr);
3648 if (adr->is_AddP() && adr_type->isa_oopptr() == nullptr && is_captured_store_address(adr)) {
3649 // We are computing a raw address for a store captured by an Initialize
3650 // compute an appropriate address type. AddP cases #3 and #5 (see below).
3651 int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
3652 assert(offs != Type::OffsetBot ||
3653 adr->in(AddPNode::Address)->in(0)->is_AllocateArray(),
3654 "offset must be a constant or it is initialization of array");
3655 return offs;
3656 }
3657 const TypePtr *t_ptr = adr_type->isa_ptr();
3658 assert(t_ptr != nullptr, "must be a pointer type");
3659 return t_ptr->offset();
3660 }
3661
3662 Node* ConnectionGraph::get_addp_base(Node *addp) {
3663 assert(addp->is_AddP(), "must be AddP");
3664 //
3665 // AddP cases for Base and Address inputs:
3666 // case #1. Direct object's field reference:
3667 // Allocate
3668 // |
3669 // Proj #5 ( oop result )
3670 // |
3671 // CheckCastPP (cast to instance type)
3672 // | |
3673 // AddP ( base == address )
3674 //
3675 // case #2. Indirect object's field reference:
3676 // Phi
3677 // |
3678 // CastPP (cast to instance type)
3679 // | |
3680 // AddP ( base == address )
3681 //
3682 // case #3. Raw object's field reference for Initialize node:
3683 // Allocate
3684 // |
3685 // Proj #5 ( oop result )
3686 // top |
3687 // \ |
3688 // AddP ( base == top )
3689 //
3690 // case #4. Array's element reference:
3691 // {CheckCastPP | CastPP}
3692 // | | |
3693 // | AddP ( array's element offset )
3694 // | |
3695 // AddP ( array's offset )
3696 //
3697 // case #5. Raw object's field reference for arraycopy stub call:
3698 // The inline_native_clone() case when the arraycopy stub is called
3699 // after the allocation before Initialize and CheckCastPP nodes.
3700 // Allocate
3701 // |
3702 // Proj #5 ( oop result )
3703 // | |
3704 // AddP ( base == address )
3705 //
3706 // case #6. Constant Pool, ThreadLocal, CastX2P or
3707 // Raw object's field reference:
3708 // {ConP, ThreadLocal, CastX2P, raw Load}
3709 // top |
3710 // \ |
3711 // AddP ( base == top )
3712 //
3713 // case #7. Klass's field reference.
3714 // LoadKlass
3715 // | |
3716 // AddP ( base == address )
3717 //
3718 // case #8. narrow Klass's field reference.
3719 // LoadNKlass
3720 // |
3721 // DecodeN
3722 // | |
3723 // AddP ( base == address )
3724 //
3725 // case #9. Mixed unsafe access
3726 // {instance}
3727 // |
3728 // CheckCastPP (raw)
3729 // top |
3730 // \ |
3731 // AddP ( base == top )
3732 //
3733 Node *base = addp->in(AddPNode::Base);
3734 if (base->uncast()->is_top()) { // The AddP case #3 and #6 and #9.
3735 base = addp->in(AddPNode::Address);
3736 while (base->is_AddP()) {
3737 // Case #6 (unsafe access) may have several chained AddP nodes.
3738 assert(base->in(AddPNode::Base)->uncast()->is_top(), "expected unsafe access address only");
3739 base = base->in(AddPNode::Address);
3740 }
3741 if (base->Opcode() == Op_CheckCastPP &&
3742 base->bottom_type()->isa_rawptr() &&
3743 _igvn->type(base->in(1))->isa_oopptr()) {
3744 base = base->in(1); // Case #9
3745 } else {
3746 Node* uncast_base = base->uncast();
3747 int opcode = uncast_base->Opcode();
3748 assert(opcode == Op_ConP || opcode == Op_ThreadLocal ||
3749 opcode == Op_CastX2P || uncast_base->is_DecodeNarrowPtr() ||
3750 (uncast_base->is_Mem() && (uncast_base->bottom_type()->isa_rawptr() != nullptr)) ||
3751 is_captured_store_address(addp), "sanity");
3752 }
3753 }
3754 return base;
3755 }
3756
3757 Node* ConnectionGraph::find_second_addp(Node* addp, Node* n) {
3758 assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
3759 Node* addp2 = addp->raw_out(0);
3760 if (addp->outcnt() == 1 && addp2->is_AddP() &&
3761 addp2->in(AddPNode::Base) == n &&
3762 addp2->in(AddPNode::Address) == addp) {
3763 assert(addp->in(AddPNode::Base) == n, "expecting the same base");
3764 //
3765 // Find array's offset to push it on worklist first and
3766 // as result process an array's element offset first (pushed second)
3767 // to avoid CastPP for the array's offset.
3768 // Otherwise the inserted CastPP (LocalVar) will point to what
3769 // the AddP (Field) points to. Which would be wrong since
3770 // the algorithm expects the CastPP has the same point as
3771 // as AddP's base CheckCastPP (LocalVar).
3772 //
3773 // ArrayAllocation
3774 // |
3775 // CheckCastPP
3776 // |
3777 // memProj (from ArrayAllocation CheckCastPP)
3778 // | ||
3779 // | || Int (element index)
3780 // | || | ConI (log(element size))
3781 // | || | /
3782 // | || LShift
3783 // | || /
3784 // | AddP (array's element offset)
3785 // | |
3786 // | | ConI (array's offset: #12(32-bits) or #24(64-bits))
3787 // | / /
3788 // AddP (array's offset)
3789 // |
3790 // Load/Store (memory operation on array's element)
3791 //
3792 return addp2;
3793 }
3794 return nullptr;
3795 }
3796
3797 //
3798 // Adjust the type and inputs of an AddP which computes the
3799 // address of a field of an instance
3800 //
3801 bool ConnectionGraph::split_AddP(Node *addp, Node *base) {
3802 PhaseGVN* igvn = _igvn;
3803 const TypeOopPtr *base_t = igvn->type(base)->isa_oopptr();
3804 assert(base_t != nullptr && base_t->is_known_instance(), "expecting instance oopptr");
3805 const TypeOopPtr *t = igvn->type(addp)->isa_oopptr();
3806 if (t == nullptr) {
3807 // We are computing a raw address for a store captured by an Initialize
3808 // compute an appropriate address type (cases #3 and #5).
3809 assert(igvn->type(addp) == TypeRawPtr::NOTNULL, "must be raw pointer");
3810 assert(addp->in(AddPNode::Address)->is_Proj(), "base of raw address must be result projection from allocation");
3811 intptr_t offs = (int)igvn->find_intptr_t_con(addp->in(AddPNode::Offset), Type::OffsetBot);
3812 assert(offs != Type::OffsetBot, "offset must be a constant");
3813 t = base_t->add_offset(offs)->is_oopptr();
3814 }
3815 int inst_id = base_t->instance_id();
3816 assert(!t->is_known_instance() || t->instance_id() == inst_id,
3817 "old type must be non-instance or match new type");
3818
3819 // The type 't' could be subclass of 'base_t'.
3820 // As result t->offset() could be large then base_t's size and it will
3821 // cause the failure in add_offset() with narrow oops since TypeOopPtr()
3822 // constructor verifies correctness of the offset.
3823 //
3824 // It could happened on subclass's branch (from the type profiling
3825 // inlining) which was not eliminated during parsing since the exactness
3826 // of the allocation type was not propagated to the subclass type check.
3827 //
3828 // Or the type 't' could be not related to 'base_t' at all.
3829 // It could happened when CHA type is different from MDO type on a dead path
3830 // (for example, from instanceof check) which is not collapsed during parsing.
3831 //
3832 // Do nothing for such AddP node and don't process its users since
3833 // this code branch will go away.
3834 //
3835 if (!t->is_known_instance() &&
3836 !base_t->maybe_java_subtype_of(t)) {
3837 return false; // bail out
3838 }
3839 const TypeOopPtr *tinst = base_t->add_offset(t->offset())->is_oopptr();
3840 // Do NOT remove the next line: ensure a new alias index is allocated
3841 // for the instance type. Note: C++ will not remove it since the call
3842 // has side effect.
3843 int alias_idx = _compile->get_alias_index(tinst);
3844 igvn->set_type(addp, tinst);
3845 // record the allocation in the node map
3846 set_map(addp, get_map(base->_idx));
3847 // Set addp's Base and Address to 'base'.
3848 Node *abase = addp->in(AddPNode::Base);
3849 Node *adr = addp->in(AddPNode::Address);
3850 if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
3851 adr->in(0)->_idx == (uint)inst_id) {
3852 // Skip AddP cases #3 and #5.
3853 } else {
3854 assert(!abase->is_top(), "sanity"); // AddP case #3
3855 if (abase != base) {
3856 igvn->hash_delete(addp);
3857 addp->set_req(AddPNode::Base, base);
3858 if (abase == adr) {
3859 addp->set_req(AddPNode::Address, base);
3860 } else {
3861 // AddP case #4 (adr is array's element offset AddP node)
3862 #ifdef ASSERT
3863 const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
3864 assert(adr->is_AddP() && atype != nullptr &&
3865 atype->instance_id() == inst_id, "array's element offset should be processed first");
3866 #endif
3867 }
3868 igvn->hash_insert(addp);
3869 }
3870 }
3871 // Put on IGVN worklist since at least addp's type was changed above.
3872 record_for_optimizer(addp);
3873 return true;
3874 }
3875
3876 //
3877 // Create a new version of orig_phi if necessary. Returns either the newly
3878 // created phi or an existing phi. Sets create_new to indicate whether a new
3879 // phi was created. Cache the last newly created phi in the node map.
3880 //
3881 PhiNode *ConnectionGraph::create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist, bool &new_created) {
3882 Compile *C = _compile;
3883 PhaseGVN* igvn = _igvn;
3884 new_created = false;
3885 int phi_alias_idx = C->get_alias_index(orig_phi->adr_type());
3886 // nothing to do if orig_phi is bottom memory or matches alias_idx
3887 if (phi_alias_idx == alias_idx) {
3888 return orig_phi;
3889 }
3890 // Have we recently created a Phi for this alias index?
3891 PhiNode *result = get_map_phi(orig_phi->_idx);
3892 if (result != nullptr && C->get_alias_index(result->adr_type()) == alias_idx) {
3893 return result;
3894 }
3895 // Previous check may fail when the same wide memory Phi was split into Phis
3896 // for different memory slices. Search all Phis for this region.
3897 if (result != nullptr) {
3898 Node* region = orig_phi->in(0);
3899 for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
3900 Node* phi = region->fast_out(i);
3901 if (phi->is_Phi() &&
3902 C->get_alias_index(phi->as_Phi()->adr_type()) == alias_idx) {
3903 assert(phi->_idx >= nodes_size(), "only new Phi per instance memory slice");
3904 return phi->as_Phi();
3905 }
3906 }
3907 }
3908 if (C->live_nodes() + 2*NodeLimitFudgeFactor > C->max_node_limit()) {
3909 if (C->do_escape_analysis() == true && !C->failing()) {
3910 // Retry compilation without escape analysis.
3911 // If this is the first failure, the sentinel string will "stick"
3912 // to the Compile object, and the C2Compiler will see it and retry.
3913 C->record_failure(_invocation > 0 ? C2Compiler::retry_no_iterative_escape_analysis() : C2Compiler::retry_no_escape_analysis());
3914 }
3915 return nullptr;
3916 }
3917 orig_phi_worklist.append_if_missing(orig_phi);
3918 const TypePtr *atype = C->get_adr_type(alias_idx);
3919 result = PhiNode::make(orig_phi->in(0), nullptr, Type::MEMORY, atype);
3920 C->copy_node_notes_to(result, orig_phi);
3921 igvn->set_type(result, result->bottom_type());
3922 record_for_optimizer(result);
3923 set_map(orig_phi, result);
3924 new_created = true;
3925 return result;
3926 }
3927
3928 //
3929 // Return a new version of Memory Phi "orig_phi" with the inputs having the
3930 // specified alias index.
3931 //
3932 PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist, uint rec_depth) {
3933 assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
3934 Compile *C = _compile;
3935 PhaseGVN* igvn = _igvn;
3936 bool new_phi_created;
3937 PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, new_phi_created);
3938 if (!new_phi_created) {
3939 return result;
3940 }
3941 GrowableArray<PhiNode *> phi_list;
3942 GrowableArray<uint> cur_input;
3943 PhiNode *phi = orig_phi;
3944 uint idx = 1;
3945 bool finished = false;
3946 while(!finished) {
3947 while (idx < phi->req()) {
3948 Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist, rec_depth + 1);
3949 if (mem != nullptr && mem->is_Phi()) {
3950 PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, new_phi_created);
3951 if (new_phi_created) {
3952 // found an phi for which we created a new split, push current one on worklist and begin
3953 // processing new one
3954 phi_list.push(phi);
3955 cur_input.push(idx);
3956 phi = mem->as_Phi();
3957 result = newphi;
3958 idx = 1;
3959 continue;
3960 } else {
3961 mem = newphi;
3962 }
3963 }
3964 if (C->failing()) {
3965 return nullptr;
3966 }
3967 result->set_req(idx++, mem);
3968 }
3969 #ifdef ASSERT
3970 // verify that the new Phi has an input for each input of the original
3971 assert( phi->req() == result->req(), "must have same number of inputs.");
3972 assert( result->in(0) != nullptr && result->in(0) == phi->in(0), "regions must match");
3973 #endif
3974 // Check if all new phi's inputs have specified alias index.
3975 // Otherwise use old phi.
3976 for (uint i = 1; i < phi->req(); i++) {
3977 Node* in = result->in(i);
3978 assert((phi->in(i) == nullptr) == (in == nullptr), "inputs must correspond.");
3979 }
3980 // we have finished processing a Phi, see if there are any more to do
3981 finished = (phi_list.length() == 0 );
3982 if (!finished) {
3983 phi = phi_list.pop();
3984 idx = cur_input.pop();
3985 PhiNode *prev_result = get_map_phi(phi->_idx);
3986 prev_result->set_req(idx++, result);
3987 result = prev_result;
3988 }
3989 }
3990 return result;
3991 }
3992
3993 //
3994 // The next methods are derived from methods in MemNode.
3995 //
3996 Node* ConnectionGraph::step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *toop) {
3997 Node *mem = mmem;
3998 // TypeOopPtr::NOTNULL+any is an OOP with unknown offset - generally
3999 // means an array I have not precisely typed yet. Do not do any
4000 // alias stuff with it any time soon.
4001 if (toop->base() != Type::AnyPtr &&
4002 !(toop->isa_instptr() &&
4003 toop->is_instptr()->instance_klass()->is_java_lang_Object() &&
4004 toop->offset() == Type::OffsetBot)) {
4005 mem = mmem->memory_at(alias_idx);
4006 // Update input if it is progress over what we have now
4007 }
4008 return mem;
4009 }
4010
4011 //
4012 // Move memory users to their memory slices.
4013 //
4014 void ConnectionGraph::move_inst_mem(Node* n, GrowableArray<PhiNode *> &orig_phis) {
4015 Compile* C = _compile;
4016 PhaseGVN* igvn = _igvn;
4017 const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr();
4018 assert(tp != nullptr, "ptr type");
4019 int alias_idx = C->get_alias_index(tp);
4020 int general_idx = C->get_general_index(alias_idx);
4021
4022 // Move users first
4023 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
4024 Node* use = n->fast_out(i);
4025 if (use->is_MergeMem()) {
4026 MergeMemNode* mmem = use->as_MergeMem();
4027 assert(n == mmem->memory_at(alias_idx), "should be on instance memory slice");
4028 if (n != mmem->memory_at(general_idx) || alias_idx == general_idx) {
4029 continue; // Nothing to do
4030 }
4031 // Replace previous general reference to mem node.
4032 uint orig_uniq = C->unique();
4033 Node* m = find_inst_mem(n, general_idx, orig_phis);
4034 assert(orig_uniq == C->unique(), "no new nodes");
4035 mmem->set_memory_at(general_idx, m);
4036 --imax;
4037 --i;
4038 } else if (use->is_MemBar()) {
4039 assert(!use->is_Initialize(), "initializing stores should not be moved");
4040 if (use->req() > MemBarNode::Precedent &&
4041 use->in(MemBarNode::Precedent) == n) {
4042 // Don't move related membars.
4043 record_for_optimizer(use);
4044 continue;
4045 }
4046 tp = use->as_MemBar()->adr_type()->isa_ptr();
4047 if ((tp != nullptr && C->get_alias_index(tp) == alias_idx) ||
4048 alias_idx == general_idx) {
4049 continue; // Nothing to do
4050 }
4051 // Move to general memory slice.
4052 uint orig_uniq = C->unique();
4053 Node* m = find_inst_mem(n, general_idx, orig_phis);
4054 assert(orig_uniq == C->unique(), "no new nodes");
4055 igvn->hash_delete(use);
4056 imax -= use->replace_edge(n, m, igvn);
4057 igvn->hash_insert(use);
4058 record_for_optimizer(use);
4059 --i;
4060 #ifdef ASSERT
4061 } else if (use->is_Mem()) {
4062 // Memory nodes should have new memory input.
4063 tp = igvn->type(use->in(MemNode::Address))->isa_ptr();
4064 assert(tp != nullptr, "ptr type");
4065 int idx = C->get_alias_index(tp);
4066 assert(get_map(use->_idx) != nullptr || idx == alias_idx,
4067 "Following memory nodes should have new memory input or be on the same memory slice");
4068 } else if (use->is_Phi()) {
4069 // Phi nodes should be split and moved already.
4070 tp = use->as_Phi()->adr_type()->isa_ptr();
4071 assert(tp != nullptr, "ptr type");
4072 int idx = C->get_alias_index(tp);
4073 assert(idx == alias_idx, "Following Phi nodes should be on the same memory slice");
4074 } else {
4075 use->dump();
4076 assert(false, "should not be here");
4077 #endif
4078 }
4079 }
4080 }
4081
4082 //
4083 // Search memory chain of "mem" to find a MemNode whose address
4084 // is the specified alias index.
4085 //
4086 #define FIND_INST_MEM_RECURSION_DEPTH_LIMIT 1000
4087 Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArray<PhiNode *> &orig_phis, uint rec_depth) {
4088 if (rec_depth > FIND_INST_MEM_RECURSION_DEPTH_LIMIT) {
4089 _compile->record_failure(_invocation > 0 ? C2Compiler::retry_no_iterative_escape_analysis() : C2Compiler::retry_no_escape_analysis());
4090 return nullptr;
4091 }
4092 if (orig_mem == nullptr) {
4093 return orig_mem;
4094 }
4095 Compile* C = _compile;
4096 PhaseGVN* igvn = _igvn;
4097 const TypeOopPtr *toop = C->get_adr_type(alias_idx)->isa_oopptr();
4098 bool is_instance = (toop != nullptr) && toop->is_known_instance();
4099 Node *start_mem = C->start()->proj_out_or_null(TypeFunc::Memory);
4100 Node *prev = nullptr;
4101 Node *result = orig_mem;
4102 while (prev != result) {
4103 prev = result;
4104 if (result == start_mem) {
4105 break; // hit one of our sentinels
4106 }
4107 if (result->is_Mem()) {
4108 const Type *at = igvn->type(result->in(MemNode::Address));
4109 if (at == Type::TOP) {
4110 break; // Dead
4111 }
4112 assert (at->isa_ptr() != nullptr, "pointer type required.");
4113 int idx = C->get_alias_index(at->is_ptr());
4114 if (idx == alias_idx) {
4115 break; // Found
4116 }
4117 if (!is_instance && (at->isa_oopptr() == nullptr ||
4118 !at->is_oopptr()->is_known_instance())) {
4119 break; // Do not skip store to general memory slice.
4120 }
4121 result = result->in(MemNode::Memory);
4122 }
4123 if (!is_instance) {
4124 continue; // don't search further for non-instance types
4125 }
4126 // skip over a call which does not affect this memory slice
4127 if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) {
4128 Node *proj_in = result->in(0);
4129 if (proj_in->is_Allocate() && proj_in->_idx == (uint)toop->instance_id()) {
4130 break; // hit one of our sentinels
4131 } else if (proj_in->is_Call()) {
4132 // ArrayCopy node processed here as well
4133 CallNode *call = proj_in->as_Call();
4134 if (!call->may_modify(toop, igvn)) {
4135 result = call->in(TypeFunc::Memory);
4136 }
4137 } else if (proj_in->is_Initialize()) {
4138 AllocateNode* alloc = proj_in->as_Initialize()->allocation();
4139 // Stop if this is the initialization for the object instance which
4140 // which contains this memory slice, otherwise skip over it.
4141 if (alloc == nullptr || alloc->_idx != (uint)toop->instance_id()) {
4142 result = proj_in->in(TypeFunc::Memory);
4143 }
4144 } else if (proj_in->is_MemBar()) {
4145 // Check if there is an array copy for a clone
4146 // Step over GC barrier when ReduceInitialCardMarks is disabled
4147 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
4148 Node* control_proj_ac = bs->step_over_gc_barrier(proj_in->in(0));
4149
4150 if (control_proj_ac->is_Proj() && control_proj_ac->in(0)->is_ArrayCopy()) {
4151 // Stop if it is a clone
4152 ArrayCopyNode* ac = control_proj_ac->in(0)->as_ArrayCopy();
4153 if (ac->may_modify(toop, igvn)) {
4154 break;
4155 }
4156 }
4157 result = proj_in->in(TypeFunc::Memory);
4158 }
4159 } else if (result->is_MergeMem()) {
4160 MergeMemNode *mmem = result->as_MergeMem();
4161 result = step_through_mergemem(mmem, alias_idx, toop);
4162 if (result == mmem->base_memory()) {
4163 // Didn't find instance memory, search through general slice recursively.
4164 result = mmem->memory_at(C->get_general_index(alias_idx));
4165 result = find_inst_mem(result, alias_idx, orig_phis, rec_depth + 1);
4166 if (C->failing()) {
4167 return nullptr;
4168 }
4169 mmem->set_memory_at(alias_idx, result);
4170 }
4171 } else if (result->is_Phi() &&
4172 C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) {
4173 Node *un = result->as_Phi()->unique_input(igvn);
4174 if (un != nullptr) {
4175 orig_phis.append_if_missing(result->as_Phi());
4176 result = un;
4177 } else {
4178 break;
4179 }
4180 } else if (result->is_ClearArray()) {
4181 if (!ClearArrayNode::step_through(&result, (uint)toop->instance_id(), igvn)) {
4182 // Can not bypass initialization of the instance
4183 // we are looking for.
4184 break;
4185 }
4186 // Otherwise skip it (the call updated 'result' value).
4187 } else if (result->Opcode() == Op_SCMemProj) {
4188 Node* mem = result->in(0);
4189 Node* adr = nullptr;
4190 if (mem->is_LoadStore()) {
4191 adr = mem->in(MemNode::Address);
4192 } else {
4193 assert(mem->Opcode() == Op_EncodeISOArray ||
4194 mem->Opcode() == Op_StrCompressedCopy, "sanity");
4195 adr = mem->in(3); // Memory edge corresponds to destination array
4196 }
4197 const Type *at = igvn->type(adr);
4198 if (at != Type::TOP) {
4199 assert(at->isa_ptr() != nullptr, "pointer type required.");
4200 int idx = C->get_alias_index(at->is_ptr());
4201 if (idx == alias_idx) {
4202 // Assert in debug mode
4203 assert(false, "Object is not scalar replaceable if a LoadStore node accesses its field");
4204 break; // In product mode return SCMemProj node
4205 }
4206 }
4207 result = mem->in(MemNode::Memory);
4208 } else if (result->Opcode() == Op_StrInflatedCopy) {
4209 Node* adr = result->in(3); // Memory edge corresponds to destination array
4210 const Type *at = igvn->type(adr);
4211 if (at != Type::TOP) {
4212 assert(at->isa_ptr() != nullptr, "pointer type required.");
4213 int idx = C->get_alias_index(at->is_ptr());
4214 if (idx == alias_idx) {
4215 // Assert in debug mode
4216 assert(false, "Object is not scalar replaceable if a StrInflatedCopy node accesses its field");
4217 break; // In product mode return SCMemProj node
4218 }
4219 }
4220 result = result->in(MemNode::Memory);
4221 }
4222 }
4223 if (result->is_Phi()) {
4224 PhiNode *mphi = result->as_Phi();
4225 assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
4226 const TypePtr *t = mphi->adr_type();
4227 if (!is_instance) {
4228 // Push all non-instance Phis on the orig_phis worklist to update inputs
4229 // during Phase 4 if needed.
4230 orig_phis.append_if_missing(mphi);
4231 } else if (C->get_alias_index(t) != alias_idx) {
4232 // Create a new Phi with the specified alias index type.
4233 result = split_memory_phi(mphi, alias_idx, orig_phis, rec_depth + 1);
4234 }
4235 }
4236 // the result is either MemNode, PhiNode, InitializeNode.
4237 return result;
4238 }
4239
4240 //
4241 // Convert the types of non-escaped object to instance types where possible,
4242 // propagate the new type information through the graph, and update memory
4243 // edges and MergeMem inputs to reflect the new type.
4244 //
4245 // We start with allocations (and calls which may be allocations) on alloc_worklist.
4246 // The processing is done in 4 phases:
4247 //
4248 // Phase 1: Process possible allocations from alloc_worklist. Create instance
4249 // types for the CheckCastPP for allocations where possible.
4250 // Propagate the new types through users as follows:
4251 // casts and Phi: push users on alloc_worklist
4252 // AddP: cast Base and Address inputs to the instance type
4253 // push any AddP users on alloc_worklist and push any memnode
4254 // users onto memnode_worklist.
4255 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
4256 // search the Memory chain for a store with the appropriate type
4257 // address type. If a Phi is found, create a new version with
4258 // the appropriate memory slices from each of the Phi inputs.
4259 // For stores, process the users as follows:
4260 // MemNode: push on memnode_worklist
4261 // MergeMem: push on mergemem_worklist
4262 // Phase 3: Process MergeMem nodes from mergemem_worklist. Walk each memory slice
4263 // moving the first node encountered of each instance type to the
4264 // the input corresponding to its alias index.
4265 // appropriate memory slice.
4266 // Phase 4: Update the inputs of non-instance memory Phis and the Memory input of memnodes.
4267 //
4268 // In the following example, the CheckCastPP nodes are the cast of allocation
4269 // results and the allocation of node 29 is non-escaped and eligible to be an
4270 // instance type.
4271 //
4272 // We start with:
4273 //
4274 // 7 Parm #memory
4275 // 10 ConI "12"
4276 // 19 CheckCastPP "Foo"
4277 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
4278 // 29 CheckCastPP "Foo"
4279 // 30 AddP _ 29 29 10 Foo+12 alias_index=4
4280 //
4281 // 40 StoreP 25 7 20 ... alias_index=4
4282 // 50 StoreP 35 40 30 ... alias_index=4
4283 // 60 StoreP 45 50 20 ... alias_index=4
4284 // 70 LoadP _ 60 30 ... alias_index=4
4285 // 80 Phi 75 50 60 Memory alias_index=4
4286 // 90 LoadP _ 80 30 ... alias_index=4
4287 // 100 LoadP _ 80 20 ... alias_index=4
4288 //
4289 //
4290 // Phase 1 creates an instance type for node 29 assigning it an instance id of 24
4291 // and creating a new alias index for node 30. This gives:
4292 //
4293 // 7 Parm #memory
4294 // 10 ConI "12"
4295 // 19 CheckCastPP "Foo"
4296 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
4297 // 29 CheckCastPP "Foo" iid=24
4298 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
4299 //
4300 // 40 StoreP 25 7 20 ... alias_index=4
4301 // 50 StoreP 35 40 30 ... alias_index=6
4302 // 60 StoreP 45 50 20 ... alias_index=4
4303 // 70 LoadP _ 60 30 ... alias_index=6
4304 // 80 Phi 75 50 60 Memory alias_index=4
4305 // 90 LoadP _ 80 30 ... alias_index=6
4306 // 100 LoadP _ 80 20 ... alias_index=4
4307 //
4308 // In phase 2, new memory inputs are computed for the loads and stores,
4309 // And a new version of the phi is created. In phase 4, the inputs to
4310 // node 80 are updated and then the memory nodes are updated with the
4311 // values computed in phase 2. This results in:
4312 //
4313 // 7 Parm #memory
4314 // 10 ConI "12"
4315 // 19 CheckCastPP "Foo"
4316 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
4317 // 29 CheckCastPP "Foo" iid=24
4318 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
4319 //
4320 // 40 StoreP 25 7 20 ... alias_index=4
4321 // 50 StoreP 35 7 30 ... alias_index=6
4322 // 60 StoreP 45 40 20 ... alias_index=4
4323 // 70 LoadP _ 50 30 ... alias_index=6
4324 // 80 Phi 75 40 60 Memory alias_index=4
4325 // 120 Phi 75 50 50 Memory alias_index=6
4326 // 90 LoadP _ 120 30 ... alias_index=6
4327 // 100 LoadP _ 80 20 ... alias_index=4
4328 //
4329 void ConnectionGraph::split_unique_types(GrowableArray<Node *> &alloc_worklist,
4330 GrowableArray<ArrayCopyNode*> &arraycopy_worklist,
4331 GrowableArray<MergeMemNode*> &mergemem_worklist,
4332 Unique_Node_List &reducible_merges) {
4333 DEBUG_ONLY(Unique_Node_List reduced_merges;)
4334 GrowableArray<Node *> memnode_worklist;
4335 GrowableArray<PhiNode *> orig_phis;
4336 PhaseIterGVN *igvn = _igvn;
4337 uint new_index_start = (uint) _compile->num_alias_types();
4338 VectorSet visited;
4339 ideal_nodes.clear(); // Reset for use with set_map/get_map.
4340 uint unique_old = _compile->unique();
4341
4342 // Phase 1: Process possible allocations from alloc_worklist.
4343 // Create instance types for the CheckCastPP for allocations where possible.
4344 //
4345 // (Note: don't forget to change the order of the second AddP node on
4346 // the alloc_worklist if the order of the worklist processing is changed,
4347 // see the comment in find_second_addp().)
4348 //
4349 while (alloc_worklist.length() != 0) {
4350 Node *n = alloc_worklist.pop();
4351 uint ni = n->_idx;
4352 if (n->is_Call()) {
4353 CallNode *alloc = n->as_Call();
4354 // copy escape information to call node
4355 PointsToNode* ptn = ptnode_adr(alloc->_idx);
4356 PointsToNode::EscapeState es = ptn->escape_state();
4357 // We have an allocation or call which returns a Java object,
4358 // see if it is non-escaped.
4359 if (es != PointsToNode::NoEscape || !ptn->scalar_replaceable()) {
4360 continue;
4361 }
4362 // Find CheckCastPP for the allocate or for the return value of a call
4363 n = alloc->result_cast();
4364 if (n == nullptr) { // No uses except Initialize node
4365 if (alloc->is_Allocate()) {
4366 // Set the scalar_replaceable flag for allocation
4367 // so it could be eliminated if it has no uses.
4368 alloc->as_Allocate()->_is_scalar_replaceable = true;
4369 }
4370 continue;
4371 }
4372 if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
4373 // we could reach here for allocate case if one init is associated with many allocs.
4374 if (alloc->is_Allocate()) {
4375 alloc->as_Allocate()->_is_scalar_replaceable = false;
4376 }
4377 continue;
4378 }
4379
4380 // The inline code for Object.clone() casts the allocation result to
4381 // java.lang.Object and then to the actual type of the allocated
4382 // object. Detect this case and use the second cast.
4383 // Also detect j.l.reflect.Array.newInstance(jobject, jint) case when
4384 // the allocation result is cast to java.lang.Object and then
4385 // to the actual Array type.
4386 if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL
4387 && (alloc->is_AllocateArray() ||
4388 igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeInstKlassPtr::OBJECT)) {
4389 Node *cast2 = nullptr;
4390 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
4391 Node *use = n->fast_out(i);
4392 if (use->is_CheckCastPP()) {
4393 cast2 = use;
4394 break;
4395 }
4396 }
4397 if (cast2 != nullptr) {
4398 n = cast2;
4399 } else {
4400 // Non-scalar replaceable if the allocation type is unknown statically
4401 // (reflection allocation), the object can't be restored during
4402 // deoptimization without precise type.
4403 continue;
4404 }
4405 }
4406
4407 const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
4408 if (t == nullptr) {
4409 continue; // not a TypeOopPtr
4410 }
4411 if (!t->klass_is_exact()) {
4412 continue; // not an unique type
4413 }
4414 if (alloc->is_Allocate()) {
4415 // Set the scalar_replaceable flag for allocation
4416 // so it could be eliminated.
4417 alloc->as_Allocate()->_is_scalar_replaceable = true;
4418 }
4419 set_escape_state(ptnode_adr(n->_idx), es NOT_PRODUCT(COMMA trace_propagate_message(ptn))); // CheckCastPP escape state
4420 // in order for an object to be scalar-replaceable, it must be:
4421 // - a direct allocation (not a call returning an object)
4422 // - non-escaping
4423 // - eligible to be a unique type
4424 // - not determined to be ineligible by escape analysis
4425 set_map(alloc, n);
4426 set_map(n, alloc);
4427 const TypeOopPtr* tinst = t->cast_to_instance_id(ni);
4428 igvn->hash_delete(n);
4429 igvn->set_type(n, tinst);
4430 n->raise_bottom_type(tinst);
4431 igvn->hash_insert(n);
4432 record_for_optimizer(n);
4433 // Allocate an alias index for the header fields. Accesses to
4434 // the header emitted during macro expansion wouldn't have
4435 // correct memory state otherwise.
4436 _compile->get_alias_index(tinst->add_offset(oopDesc::mark_offset_in_bytes()));
4437 _compile->get_alias_index(tinst->add_offset(Type::klass_offset()));
4438 if (alloc->is_Allocate() && (t->isa_instptr() || t->isa_aryptr())) {
4439
4440 // First, put on the worklist all Field edges from Connection Graph
4441 // which is more accurate than putting immediate users from Ideal Graph.
4442 for (EdgeIterator e(ptn); e.has_next(); e.next()) {
4443 PointsToNode* tgt = e.get();
4444 if (tgt->is_Arraycopy()) {
4445 continue;
4446 }
4447 Node* use = tgt->ideal_node();
4448 assert(tgt->is_Field() && use->is_AddP(),
4449 "only AddP nodes are Field edges in CG");
4450 if (use->outcnt() > 0) { // Don't process dead nodes
4451 Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
4452 if (addp2 != nullptr) {
4453 assert(alloc->is_AllocateArray(),"array allocation was expected");
4454 alloc_worklist.append_if_missing(addp2);
4455 }
4456 alloc_worklist.append_if_missing(use);
4457 }
4458 }
4459
4460 // An allocation may have an Initialize which has raw stores. Scan
4461 // the users of the raw allocation result and push AddP users
4462 // on alloc_worklist.
4463 Node *raw_result = alloc->proj_out_or_null(TypeFunc::Parms);
4464 assert (raw_result != nullptr, "must have an allocation result");
4465 for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
4466 Node *use = raw_result->fast_out(i);
4467 if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
4468 Node* addp2 = find_second_addp(use, raw_result);
4469 if (addp2 != nullptr) {
4470 assert(alloc->is_AllocateArray(),"array allocation was expected");
4471 alloc_worklist.append_if_missing(addp2);
4472 }
4473 alloc_worklist.append_if_missing(use);
4474 } else if (use->is_MemBar()) {
4475 memnode_worklist.append_if_missing(use);
4476 }
4477 }
4478 }
4479 } else if (n->is_AddP()) {
4480 if (has_reducible_merge_base(n->as_AddP(), reducible_merges)) {
4481 // This AddP will go away when we reduce the Phi
4482 continue;
4483 }
4484 Node* addp_base = get_addp_base(n);
4485 JavaObjectNode* jobj = unique_java_object(addp_base);
4486 if (jobj == nullptr || jobj == phantom_obj) {
4487 #ifdef ASSERT
4488 ptnode_adr(get_addp_base(n)->_idx)->dump();
4489 ptnode_adr(n->_idx)->dump();
4490 assert(jobj != nullptr && jobj != phantom_obj, "escaped allocation");
4491 #endif
4492 _compile->record_failure(_invocation > 0 ? C2Compiler::retry_no_iterative_escape_analysis() : C2Compiler::retry_no_escape_analysis());
4493 return;
4494 }
4495 Node *base = get_map(jobj->idx()); // CheckCastPP node
4496 if (!split_AddP(n, base)) continue; // wrong type from dead path
4497 } else if (n->is_Phi() ||
4498 n->is_CheckCastPP() ||
4499 n->is_EncodeP() ||
4500 n->is_DecodeN() ||
4501 (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
4502 if (visited.test_set(n->_idx)) {
4503 assert(n->is_Phi(), "loops only through Phi's");
4504 continue; // already processed
4505 }
4506 // Reducible Phi's will be removed from the graph after split_unique_types
4507 // finishes. For now we just try to split out the SR inputs of the merge.
4508 Node* parent = n->in(1);
4509 if (reducible_merges.member(n)) {
4510 reduce_phi(n->as_Phi(), alloc_worklist, memnode_worklist);
4511 #ifdef ASSERT
4512 if (VerifyReduceAllocationMerges) {
4513 reduced_merges.push(n);
4514 }
4515 #endif
4516 continue;
4517 } else if (reducible_merges.member(parent)) {
4518 // 'n' is an user of a reducible merge (a Phi). It will be simplified as
4519 // part of reduce_merge.
4520 continue;
4521 }
4522 JavaObjectNode* jobj = unique_java_object(n);
4523 if (jobj == nullptr || jobj == phantom_obj) {
4524 #ifdef ASSERT
4525 ptnode_adr(n->_idx)->dump();
4526 assert(jobj != nullptr && jobj != phantom_obj, "escaped allocation");
4527 #endif
4528 _compile->record_failure(_invocation > 0 ? C2Compiler::retry_no_iterative_escape_analysis() : C2Compiler::retry_no_escape_analysis());
4529 return;
4530 } else {
4531 Node *val = get_map(jobj->idx()); // CheckCastPP node
4532 TypeNode *tn = n->as_Type();
4533 const TypeOopPtr* tinst = igvn->type(val)->isa_oopptr();
4534 assert(tinst != nullptr && tinst->is_known_instance() &&
4535 tinst->instance_id() == jobj->idx() , "instance type expected.");
4536
4537 const Type *tn_type = igvn->type(tn);
4538 const TypeOopPtr *tn_t;
4539 if (tn_type->isa_narrowoop()) {
4540 tn_t = tn_type->make_ptr()->isa_oopptr();
4541 } else {
4542 tn_t = tn_type->isa_oopptr();
4543 }
4544 if (tn_t != nullptr && tinst->maybe_java_subtype_of(tn_t)) {
4545 if (tn_type->isa_narrowoop()) {
4546 tn_type = tinst->make_narrowoop();
4547 } else {
4548 tn_type = tinst;
4549 }
4550 igvn->hash_delete(tn);
4551 igvn->set_type(tn, tn_type);
4552 tn->set_type(tn_type);
4553 igvn->hash_insert(tn);
4554 record_for_optimizer(n);
4555 } else {
4556 assert(tn_type == TypePtr::NULL_PTR ||
4557 (tn_t != nullptr && !tinst->maybe_java_subtype_of(tn_t)),
4558 "unexpected type");
4559 continue; // Skip dead path with different type
4560 }
4561 }
4562 } else {
4563 debug_only(n->dump();)
4564 assert(false, "EA: unexpected node");
4565 continue;
4566 }
4567 // push allocation's users on appropriate worklist
4568 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
4569 Node *use = n->fast_out(i);
4570 if(use->is_Mem() && use->in(MemNode::Address) == n) {
4571 // Load/store to instance's field
4572 memnode_worklist.append_if_missing(use);
4573 } else if (use->is_MemBar()) {
4574 if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
4575 memnode_worklist.append_if_missing(use);
4576 }
4577 } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
4578 Node* addp2 = find_second_addp(use, n);
4579 if (addp2 != nullptr) {
4580 alloc_worklist.append_if_missing(addp2);
4581 }
4582 alloc_worklist.append_if_missing(use);
4583 } else if (use->is_Phi() ||
4584 use->is_CheckCastPP() ||
4585 use->is_EncodeNarrowPtr() ||
4586 use->is_DecodeNarrowPtr() ||
4587 (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
4588 alloc_worklist.append_if_missing(use);
4589 #ifdef ASSERT
4590 } else if (use->is_Mem()) {
4591 assert(use->in(MemNode::Address) != n, "EA: missing allocation reference path");
4592 } else if (use->is_MergeMem()) {
4593 assert(mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
4594 } else if (use->is_SafePoint()) {
4595 // Look for MergeMem nodes for calls which reference unique allocation
4596 // (through CheckCastPP nodes) even for debug info.
4597 Node* m = use->in(TypeFunc::Memory);
4598 if (m->is_MergeMem()) {
4599 assert(mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
4600 }
4601 } else if (use->Opcode() == Op_EncodeISOArray) {
4602 if (use->in(MemNode::Memory) == n || use->in(3) == n) {
4603 // EncodeISOArray overwrites destination array
4604 memnode_worklist.append_if_missing(use);
4605 }
4606 } else {
4607 uint op = use->Opcode();
4608 if ((op == Op_StrCompressedCopy || op == Op_StrInflatedCopy) &&
4609 (use->in(MemNode::Memory) == n)) {
4610 // They overwrite memory edge corresponding to destination array,
4611 memnode_worklist.append_if_missing(use);
4612 } else if (!(op == Op_CmpP || op == Op_Conv2B ||
4613 op == Op_CastP2X ||
4614 op == Op_FastLock || op == Op_AryEq ||
4615 op == Op_StrComp || op == Op_CountPositives ||
4616 op == Op_StrCompressedCopy || op == Op_StrInflatedCopy ||
4617 op == Op_StrEquals || op == Op_VectorizedHashCode ||
4618 op == Op_StrIndexOf || op == Op_StrIndexOfChar ||
4619 op == Op_SubTypeCheck ||
4620 op == Op_ReinterpretS2HF ||
4621 BarrierSet::barrier_set()->barrier_set_c2()->is_gc_barrier_node(use))) {
4622 n->dump();
4623 use->dump();
4624 assert(false, "EA: missing allocation reference path");
4625 }
4626 #endif
4627 }
4628 }
4629
4630 }
4631
4632 #ifdef ASSERT
4633 if (VerifyReduceAllocationMerges) {
4634 for (uint i = 0; i < reducible_merges.size(); i++) {
4635 Node* phi = reducible_merges.at(i);
4636
4637 if (!reduced_merges.member(phi)) {
4638 phi->dump(2);
4639 phi->dump(-2);
4640 assert(false, "This reducible merge wasn't reduced.");
4641 }
4642
4643 // At this point reducible Phis shouldn't have AddP users anymore; only SafePoints or Casts.
4644 for (DUIterator_Fast jmax, j = phi->fast_outs(jmax); j < jmax; j++) {
4645 Node* use = phi->fast_out(j);
4646 if (!use->is_SafePoint() && !use->is_CastPP()) {
4647 phi->dump(2);
4648 phi->dump(-2);
4649 assert(false, "Unexpected user of reducible Phi -> %d:%s:%d", use->_idx, use->Name(), use->outcnt());
4650 }
4651 }
4652 }
4653 }
4654 #endif
4655
4656 // Go over all ArrayCopy nodes and if one of the inputs has a unique
4657 // type, record it in the ArrayCopy node so we know what memory this
4658 // node uses/modified.
4659 for (int next = 0; next < arraycopy_worklist.length(); next++) {
4660 ArrayCopyNode* ac = arraycopy_worklist.at(next);
4661 Node* dest = ac->in(ArrayCopyNode::Dest);
4662 if (dest->is_AddP()) {
4663 dest = get_addp_base(dest);
4664 }
4665 JavaObjectNode* jobj = unique_java_object(dest);
4666 if (jobj != nullptr) {
4667 Node *base = get_map(jobj->idx());
4668 if (base != nullptr) {
4669 const TypeOopPtr *base_t = _igvn->type(base)->isa_oopptr();
4670 ac->_dest_type = base_t;
4671 }
4672 }
4673 Node* src = ac->in(ArrayCopyNode::Src);
4674 if (src->is_AddP()) {
4675 src = get_addp_base(src);
4676 }
4677 jobj = unique_java_object(src);
4678 if (jobj != nullptr) {
4679 Node* base = get_map(jobj->idx());
4680 if (base != nullptr) {
4681 const TypeOopPtr *base_t = _igvn->type(base)->isa_oopptr();
4682 ac->_src_type = base_t;
4683 }
4684 }
4685 }
4686
4687 // New alias types were created in split_AddP().
4688 uint new_index_end = (uint) _compile->num_alias_types();
4689
4690 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
4691 // compute new values for Memory inputs (the Memory inputs are not
4692 // actually updated until phase 4.)
4693 if (memnode_worklist.length() == 0)
4694 return; // nothing to do
4695 while (memnode_worklist.length() != 0) {
4696 Node *n = memnode_worklist.pop();
4697 if (visited.test_set(n->_idx)) {
4698 continue;
4699 }
4700 if (n->is_Phi() || n->is_ClearArray()) {
4701 // we don't need to do anything, but the users must be pushed
4702 } else if (n->is_MemBar()) { // Initialize, MemBar nodes
4703 // we don't need to do anything, but the users must be pushed
4704 n = n->as_MemBar()->proj_out_or_null(TypeFunc::Memory);
4705 if (n == nullptr) {
4706 continue;
4707 }
4708 } else if (n->is_CallLeaf()) {
4709 // Runtime calls with narrow memory input (no MergeMem node)
4710 // get the memory projection
4711 n = n->as_Call()->proj_out_or_null(TypeFunc::Memory);
4712 if (n == nullptr) {
4713 continue;
4714 }
4715 } else if (n->Opcode() == Op_StrInflatedCopy) {
4716 // Check direct uses of StrInflatedCopy.
4717 // It is memory type Node - no special SCMemProj node.
4718 } else if (n->Opcode() == Op_StrCompressedCopy ||
4719 n->Opcode() == Op_EncodeISOArray) {
4720 // get the memory projection
4721 n = n->find_out_with(Op_SCMemProj);
4722 assert(n != nullptr && n->Opcode() == Op_SCMemProj, "memory projection required");
4723 } else {
4724 #ifdef ASSERT
4725 if (!n->is_Mem()) {
4726 n->dump();
4727 }
4728 assert(n->is_Mem(), "memory node required.");
4729 #endif
4730 Node *addr = n->in(MemNode::Address);
4731 const Type *addr_t = igvn->type(addr);
4732 if (addr_t == Type::TOP) {
4733 continue;
4734 }
4735 assert (addr_t->isa_ptr() != nullptr, "pointer type required.");
4736 int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
4737 assert ((uint)alias_idx < new_index_end, "wrong alias index");
4738 Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis);
4739 if (_compile->failing()) {
4740 return;
4741 }
4742 if (mem != n->in(MemNode::Memory)) {
4743 // We delay the memory edge update since we need old one in
4744 // MergeMem code below when instances memory slices are separated.
4745 set_map(n, mem);
4746 }
4747 if (n->is_Load()) {
4748 continue; // don't push users
4749 } else if (n->is_LoadStore()) {
4750 // get the memory projection
4751 n = n->find_out_with(Op_SCMemProj);
4752 assert(n != nullptr && n->Opcode() == Op_SCMemProj, "memory projection required");
4753 }
4754 }
4755 // push user on appropriate worklist
4756 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
4757 Node *use = n->fast_out(i);
4758 if (use->is_Phi() || use->is_ClearArray()) {
4759 memnode_worklist.append_if_missing(use);
4760 } else if (use->is_Mem() && use->in(MemNode::Memory) == n) {
4761 memnode_worklist.append_if_missing(use);
4762 } else if (use->is_MemBar() || use->is_CallLeaf()) {
4763 if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
4764 memnode_worklist.append_if_missing(use);
4765 }
4766 #ifdef ASSERT
4767 } else if(use->is_Mem()) {
4768 assert(use->in(MemNode::Memory) != n, "EA: missing memory path");
4769 } else if (use->is_MergeMem()) {
4770 assert(mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
4771 } else if (use->Opcode() == Op_EncodeISOArray) {
4772 if (use->in(MemNode::Memory) == n || use->in(3) == n) {
4773 // EncodeISOArray overwrites destination array
4774 memnode_worklist.append_if_missing(use);
4775 }
4776 } else {
4777 uint op = use->Opcode();
4778 if ((use->in(MemNode::Memory) == n) &&
4779 (op == Op_StrCompressedCopy || op == Op_StrInflatedCopy)) {
4780 // They overwrite memory edge corresponding to destination array,
4781 memnode_worklist.append_if_missing(use);
4782 } else if (!(BarrierSet::barrier_set()->barrier_set_c2()->is_gc_barrier_node(use) ||
4783 op == Op_AryEq || op == Op_StrComp || op == Op_CountPositives ||
4784 op == Op_StrCompressedCopy || op == Op_StrInflatedCopy || op == Op_VectorizedHashCode ||
4785 op == Op_StrEquals || op == Op_StrIndexOf || op == Op_StrIndexOfChar)) {
4786 n->dump();
4787 use->dump();
4788 assert(false, "EA: missing memory path");
4789 }
4790 #endif
4791 }
4792 }
4793 }
4794
4795 // Phase 3: Process MergeMem nodes from mergemem_worklist.
4796 // Walk each memory slice moving the first node encountered of each
4797 // instance type to the input corresponding to its alias index.
4798 uint length = mergemem_worklist.length();
4799 for( uint next = 0; next < length; ++next ) {
4800 MergeMemNode* nmm = mergemem_worklist.at(next);
4801 assert(!visited.test_set(nmm->_idx), "should not be visited before");
4802 // Note: we don't want to use MergeMemStream here because we only want to
4803 // scan inputs which exist at the start, not ones we add during processing.
4804 // Note 2: MergeMem may already contains instance memory slices added
4805 // during find_inst_mem() call when memory nodes were processed above.
4806 igvn->hash_delete(nmm);
4807 uint nslices = MIN2(nmm->req(), new_index_start);
4808 for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) {
4809 Node* mem = nmm->in(i);
4810 Node* cur = nullptr;
4811 if (mem == nullptr || mem->is_top()) {
4812 continue;
4813 }
4814 // First, update mergemem by moving memory nodes to corresponding slices
4815 // if their type became more precise since this mergemem was created.
4816 while (mem->is_Mem()) {
4817 const Type *at = igvn->type(mem->in(MemNode::Address));
4818 if (at != Type::TOP) {
4819 assert (at->isa_ptr() != nullptr, "pointer type required.");
4820 uint idx = (uint)_compile->get_alias_index(at->is_ptr());
4821 if (idx == i) {
4822 if (cur == nullptr) {
4823 cur = mem;
4824 }
4825 } else {
4826 if (idx >= nmm->req() || nmm->is_empty_memory(nmm->in(idx))) {
4827 nmm->set_memory_at(idx, mem);
4828 }
4829 }
4830 }
4831 mem = mem->in(MemNode::Memory);
4832 }
4833 nmm->set_memory_at(i, (cur != nullptr) ? cur : mem);
4834 // Find any instance of the current type if we haven't encountered
4835 // already a memory slice of the instance along the memory chain.
4836 for (uint ni = new_index_start; ni < new_index_end; ni++) {
4837 if((uint)_compile->get_general_index(ni) == i) {
4838 Node *m = (ni >= nmm->req()) ? nmm->empty_memory() : nmm->in(ni);
4839 if (nmm->is_empty_memory(m)) {
4840 Node* result = find_inst_mem(mem, ni, orig_phis);
4841 if (_compile->failing()) {
4842 return;
4843 }
4844 nmm->set_memory_at(ni, result);
4845 }
4846 }
4847 }
4848 }
4849 // Find the rest of instances values
4850 for (uint ni = new_index_start; ni < new_index_end; ni++) {
4851 const TypeOopPtr *tinst = _compile->get_adr_type(ni)->isa_oopptr();
4852 Node* result = step_through_mergemem(nmm, ni, tinst);
4853 if (result == nmm->base_memory()) {
4854 // Didn't find instance memory, search through general slice recursively.
4855 result = nmm->memory_at(_compile->get_general_index(ni));
4856 result = find_inst_mem(result, ni, orig_phis);
4857 if (_compile->failing()) {
4858 return;
4859 }
4860 nmm->set_memory_at(ni, result);
4861 }
4862 }
4863
4864 // If we have crossed the 3/4 point of max node limit it's too risky
4865 // to continue with EA/SR because we might hit the max node limit.
4866 if (_compile->live_nodes() >= _compile->max_node_limit() * 0.75) {
4867 if (_compile->do_reduce_allocation_merges()) {
4868 _compile->record_failure(C2Compiler::retry_no_reduce_allocation_merges());
4869 } else if (_invocation > 0) {
4870 _compile->record_failure(C2Compiler::retry_no_iterative_escape_analysis());
4871 } else {
4872 _compile->record_failure(C2Compiler::retry_no_escape_analysis());
4873 }
4874 return;
4875 }
4876
4877 igvn->hash_insert(nmm);
4878 record_for_optimizer(nmm);
4879 }
4880
4881 // Phase 4: Update the inputs of non-instance memory Phis and
4882 // the Memory input of memnodes
4883 // First update the inputs of any non-instance Phi's from
4884 // which we split out an instance Phi. Note we don't have
4885 // to recursively process Phi's encountered on the input memory
4886 // chains as is done in split_memory_phi() since they will
4887 // also be processed here.
4888 for (int j = 0; j < orig_phis.length(); j++) {
4889 PhiNode *phi = orig_phis.at(j);
4890 int alias_idx = _compile->get_alias_index(phi->adr_type());
4891 igvn->hash_delete(phi);
4892 for (uint i = 1; i < phi->req(); i++) {
4893 Node *mem = phi->in(i);
4894 Node *new_mem = find_inst_mem(mem, alias_idx, orig_phis);
4895 if (_compile->failing()) {
4896 return;
4897 }
4898 if (mem != new_mem) {
4899 phi->set_req(i, new_mem);
4900 }
4901 }
4902 igvn->hash_insert(phi);
4903 record_for_optimizer(phi);
4904 }
4905
4906 // Update the memory inputs of MemNodes with the value we computed
4907 // in Phase 2 and move stores memory users to corresponding memory slices.
4908 // Disable memory split verification code until the fix for 6984348.
4909 // Currently it produces false negative results since it does not cover all cases.
4910 #if 0 // ifdef ASSERT
4911 visited.Reset();
4912 Node_Stack old_mems(arena, _compile->unique() >> 2);
4913 #endif
4914 for (uint i = 0; i < ideal_nodes.size(); i++) {
4915 Node* n = ideal_nodes.at(i);
4916 Node* nmem = get_map(n->_idx);
4917 assert(nmem != nullptr, "sanity");
4918 if (n->is_Mem()) {
4919 #if 0 // ifdef ASSERT
4920 Node* old_mem = n->in(MemNode::Memory);
4921 if (!visited.test_set(old_mem->_idx)) {
4922 old_mems.push(old_mem, old_mem->outcnt());
4923 }
4924 #endif
4925 assert(n->in(MemNode::Memory) != nmem, "sanity");
4926 if (!n->is_Load()) {
4927 // Move memory users of a store first.
4928 move_inst_mem(n, orig_phis);
4929 }
4930 // Now update memory input
4931 igvn->hash_delete(n);
4932 n->set_req(MemNode::Memory, nmem);
4933 igvn->hash_insert(n);
4934 record_for_optimizer(n);
4935 } else {
4936 assert(n->is_Allocate() || n->is_CheckCastPP() ||
4937 n->is_AddP() || n->is_Phi(), "unknown node used for set_map()");
4938 }
4939 }
4940 #if 0 // ifdef ASSERT
4941 // Verify that memory was split correctly
4942 while (old_mems.is_nonempty()) {
4943 Node* old_mem = old_mems.node();
4944 uint old_cnt = old_mems.index();
4945 old_mems.pop();
4946 assert(old_cnt == old_mem->outcnt(), "old mem could be lost");
4947 }
4948 #endif
4949 }
4950
4951 #ifndef PRODUCT
4952 int ConnectionGraph::_no_escape_counter = 0;
4953 int ConnectionGraph::_arg_escape_counter = 0;
4954 int ConnectionGraph::_global_escape_counter = 0;
4955
4956 static const char *node_type_names[] = {
4957 "UnknownType",
4958 "JavaObject",
4959 "LocalVar",
4960 "Field",
4961 "Arraycopy"
4962 };
4963
4964 static const char *esc_names[] = {
4965 "UnknownEscape",
4966 "NoEscape",
4967 "ArgEscape",
4968 "GlobalEscape"
4969 };
4970
4971 void PointsToNode::dump_header(bool print_state, outputStream* out) const {
4972 NodeType nt = node_type();
4973 out->print("%s(%d) ", node_type_names[(int) nt], _pidx);
4974 if (print_state) {
4975 EscapeState es = escape_state();
4976 EscapeState fields_es = fields_escape_state();
4977 out->print("%s(%s) ", esc_names[(int)es], esc_names[(int)fields_es]);
4978 if (nt == PointsToNode::JavaObject && !this->scalar_replaceable()) {
4979 out->print("NSR ");
4980 }
4981 }
4982 }
4983
4984 void PointsToNode::dump(bool print_state, outputStream* out, bool newline) const {
4985 dump_header(print_state, out);
4986 if (is_Field()) {
4987 FieldNode* f = (FieldNode*)this;
4988 if (f->is_oop()) {
4989 out->print("oop ");
4990 }
4991 if (f->offset() > 0) {
4992 out->print("+%d ", f->offset());
4993 }
4994 out->print("(");
4995 for (BaseIterator i(f); i.has_next(); i.next()) {
4996 PointsToNode* b = i.get();
4997 out->print(" %d%s", b->idx(),(b->is_JavaObject() ? "P" : ""));
4998 }
4999 out->print(" )");
5000 }
5001 out->print("[");
5002 for (EdgeIterator i(this); i.has_next(); i.next()) {
5003 PointsToNode* e = i.get();
5004 out->print(" %d%s%s", e->idx(),(e->is_JavaObject() ? "P" : (e->is_Field() ? "F" : "")), e->is_Arraycopy() ? "cp" : "");
5005 }
5006 out->print(" [");
5007 for (UseIterator i(this); i.has_next(); i.next()) {
5008 PointsToNode* u = i.get();
5009 bool is_base = false;
5010 if (PointsToNode::is_base_use(u)) {
5011 is_base = true;
5012 u = PointsToNode::get_use_node(u)->as_Field();
5013 }
5014 out->print(" %d%s%s", u->idx(), is_base ? "b" : "", u->is_Arraycopy() ? "cp" : "");
5015 }
5016 out->print(" ]] ");
5017 if (_node == nullptr) {
5018 out->print("<null>%s", newline ? "\n" : "");
5019 } else {
5020 _node->dump(newline ? "\n" : "", false, out);
5021 }
5022 }
5023
5024 void ConnectionGraph::dump(GrowableArray<PointsToNode*>& ptnodes_worklist) {
5025 bool first = true;
5026 int ptnodes_length = ptnodes_worklist.length();
5027 for (int i = 0; i < ptnodes_length; i++) {
5028 PointsToNode *ptn = ptnodes_worklist.at(i);
5029 if (ptn == nullptr || !ptn->is_JavaObject()) {
5030 continue;
5031 }
5032 PointsToNode::EscapeState es = ptn->escape_state();
5033 if ((es != PointsToNode::NoEscape) && !Verbose) {
5034 continue;
5035 }
5036 Node* n = ptn->ideal_node();
5037 if (n->is_Allocate() || (n->is_CallStaticJava() &&
5038 n->as_CallStaticJava()->is_boxing_method())) {
5039 if (first) {
5040 tty->cr();
5041 tty->print("======== Connection graph for ");
5042 _compile->method()->print_short_name();
5043 tty->cr();
5044 tty->print_cr("invocation #%d: %d iterations and %f sec to build connection graph with %d nodes and worklist size %d",
5045 _invocation, _build_iterations, _build_time, nodes_size(), ptnodes_worklist.length());
5046 tty->cr();
5047 first = false;
5048 }
5049 ptn->dump();
5050 // Print all locals and fields which reference this allocation
5051 for (UseIterator j(ptn); j.has_next(); j.next()) {
5052 PointsToNode* use = j.get();
5053 if (use->is_LocalVar()) {
5054 use->dump(Verbose);
5055 } else if (Verbose) {
5056 use->dump();
5057 }
5058 }
5059 tty->cr();
5060 }
5061 }
5062 }
5063
5064 void ConnectionGraph::print_statistics() {
5065 tty->print_cr("No escape = %d, Arg escape = %d, Global escape = %d", Atomic::load(&_no_escape_counter), Atomic::load(&_arg_escape_counter), Atomic::load(&_global_escape_counter));
5066 }
5067
5068 void ConnectionGraph::escape_state_statistics(GrowableArray<JavaObjectNode*>& java_objects_worklist) {
5069 if (!PrintOptoStatistics || (_invocation > 0)) { // Collect data only for the first invocation
5070 return;
5071 }
5072 for (int next = 0; next < java_objects_worklist.length(); ++next) {
5073 JavaObjectNode* ptn = java_objects_worklist.at(next);
5074 if (ptn->ideal_node()->is_Allocate()) {
5075 if (ptn->escape_state() == PointsToNode::NoEscape) {
5076 Atomic::inc(&ConnectionGraph::_no_escape_counter);
5077 } else if (ptn->escape_state() == PointsToNode::ArgEscape) {
5078 Atomic::inc(&ConnectionGraph::_arg_escape_counter);
5079 } else if (ptn->escape_state() == PointsToNode::GlobalEscape) {
5080 Atomic::inc(&ConnectionGraph::_global_escape_counter);
5081 } else {
5082 assert(false, "Unexpected Escape State");
5083 }
5084 }
5085 }
5086 }
5087
5088 void ConnectionGraph::trace_es_update_helper(PointsToNode* ptn, PointsToNode::EscapeState es, bool fields, const char* reason) const {
5089 if (_compile->directive()->TraceEscapeAnalysisOption) {
5090 assert(ptn != nullptr, "should not be null");
5091 assert(reason != nullptr, "should not be null");
5092 ptn->dump_header(true);
5093 PointsToNode::EscapeState new_es = fields ? ptn->escape_state() : es;
5094 PointsToNode::EscapeState new_fields_es = fields ? es : ptn->fields_escape_state();
5095 tty->print_cr("-> %s(%s) %s", esc_names[(int)new_es], esc_names[(int)new_fields_es], reason);
5096 }
5097 }
5098
5099 const char* ConnectionGraph::trace_propagate_message(PointsToNode* from) const {
5100 if (_compile->directive()->TraceEscapeAnalysisOption) {
5101 stringStream ss;
5102 ss.print("propagated from: ");
5103 from->dump(true, &ss, false);
5104 return ss.as_string();
5105 } else {
5106 return nullptr;
5107 }
5108 }
5109
5110 const char* ConnectionGraph::trace_arg_escape_message(CallNode* call) const {
5111 if (_compile->directive()->TraceEscapeAnalysisOption) {
5112 stringStream ss;
5113 ss.print("escapes as arg to:");
5114 call->dump("", false, &ss);
5115 return ss.as_string();
5116 } else {
5117 return nullptr;
5118 }
5119 }
5120
5121 const char* ConnectionGraph::trace_merged_message(PointsToNode* other) const {
5122 if (_compile->directive()->TraceEscapeAnalysisOption) {
5123 stringStream ss;
5124 ss.print("is merged with other object: ");
5125 other->dump_header(true, &ss);
5126 return ss.as_string();
5127 } else {
5128 return nullptr;
5129 }
5130 }
5131
5132 #endif
5133
5134 void ConnectionGraph::record_for_optimizer(Node *n) {
5135 _igvn->_worklist.push(n);
5136 _igvn->add_users_to_worklist(n);
5137 }