1 /*
2 * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "compiler/compileLog.hpp"
27 #include "interpreter/linkResolver.hpp"
28 #include "oops/method.hpp"
29 #include "opto/addnode.hpp"
30 #include "opto/idealGraphPrinter.hpp"
31 #include "opto/locknode.hpp"
32 #include "opto/memnode.hpp"
33 #include "opto/parse.hpp"
34 #include "opto/rootnode.hpp"
35 #include "opto/runtime.hpp"
36 #include "runtime/arguments.hpp"
37 #include "runtime/handles.inline.hpp"
38 #include "runtime/sharedRuntime.hpp"
39 #include "utilities/copy.hpp"
40
41 // Static array so we can figure out which bytecodes stop us from compiling
42 // the most. Some of the non-static variables are needed in bytecodeInfo.cpp
43 // and eventually should be encapsulated in a proper class (gri 8/18/98).
44
45 int nodes_created = 0;
46 int methods_parsed = 0;
47 int methods_seen = 0;
48 int blocks_parsed = 0;
49 int blocks_seen = 0;
50
51 int explicit_null_checks_inserted = 0;
52 int explicit_null_checks_elided = 0;
53 int all_null_checks_found = 0, implicit_null_checks = 0;
54 int implicit_null_throws = 0;
55
56 int reclaim_idx = 0;
57 int reclaim_in = 0;
58 int reclaim_node = 0;
59
60 #ifndef PRODUCT
61 bool Parse::BytecodeParseHistogram::_initialized = false;
62 uint Parse::BytecodeParseHistogram::_bytecodes_parsed [Bytecodes::number_of_codes];
63 uint Parse::BytecodeParseHistogram::_nodes_constructed[Bytecodes::number_of_codes];
64 uint Parse::BytecodeParseHistogram::_nodes_transformed[Bytecodes::number_of_codes];
65 uint Parse::BytecodeParseHistogram::_new_values [Bytecodes::number_of_codes];
66 #endif
67
68 //------------------------------print_statistics-------------------------------
69 #ifndef PRODUCT
70 void Parse::print_statistics() {
71 tty->print_cr("--- Compiler Statistics ---");
72 tty->print("Methods seen: %d Methods parsed: %d", methods_seen, methods_parsed);
73 tty->print(" Nodes created: %d", nodes_created);
74 tty->cr();
75 if (methods_seen != methods_parsed)
76 tty->print_cr("Reasons for parse failures (NOT cumulative):");
77 tty->print_cr("Blocks parsed: %d Blocks seen: %d", blocks_parsed, blocks_seen);
78
79 if( explicit_null_checks_inserted )
80 tty->print_cr("%d original NULL checks - %d elided (%2d%%); optimizer leaves %d,", explicit_null_checks_inserted, explicit_null_checks_elided, (100*explicit_null_checks_elided)/explicit_null_checks_inserted, all_null_checks_found);
81 if( all_null_checks_found )
82 tty->print_cr("%d made implicit (%2d%%)", implicit_null_checks,
83 (100*implicit_null_checks)/all_null_checks_found);
84 if( implicit_null_throws )
85 tty->print_cr("%d implicit null exceptions at runtime",
86 implicit_null_throws);
87
88 if( PrintParseStatistics && BytecodeParseHistogram::initialized() ) {
89 BytecodeParseHistogram::print();
90 }
91 }
92 #endif
93
94 //------------------------------ON STACK REPLACEMENT---------------------------
95
96 // Construct a node which can be used to get incoming state for
97 // on stack replacement.
98 Node *Parse::fetch_interpreter_state(int index,
99 BasicType bt,
100 Node *local_addrs,
101 Node *local_addrs_base) {
102 Node *mem = memory(Compile::AliasIdxRaw);
103 Node *adr = basic_plus_adr( local_addrs_base, local_addrs, -index*wordSize );
104 Node *ctl = control();
105
106 // Very similar to LoadNode::make, except we handle un-aligned longs and
107 // doubles on Sparc. Intel can handle them just fine directly.
108 Node *l;
109 switch( bt ) { // Signature is flattened
110 case T_INT: l = new (C) LoadINode( ctl, mem, adr, TypeRawPtr::BOTTOM ); break;
111 case T_FLOAT: l = new (C) LoadFNode( ctl, mem, adr, TypeRawPtr::BOTTOM ); break;
112 case T_ADDRESS: l = new (C) LoadPNode( ctl, mem, adr, TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM ); break;
113 case T_OBJECT: l = new (C) LoadPNode( ctl, mem, adr, TypeRawPtr::BOTTOM, TypeInstPtr::BOTTOM ); break;
114 case T_LONG:
115 case T_DOUBLE: {
116 // Since arguments are in reverse order, the argument address 'adr'
117 // refers to the back half of the long/double. Recompute adr.
118 adr = basic_plus_adr( local_addrs_base, local_addrs, -(index+1)*wordSize );
119 if( Matcher::misaligned_doubles_ok ) {
120 l = (bt == T_DOUBLE)
121 ? (Node*)new (C) LoadDNode( ctl, mem, adr, TypeRawPtr::BOTTOM )
122 : (Node*)new (C) LoadLNode( ctl, mem, adr, TypeRawPtr::BOTTOM );
123 } else {
124 l = (bt == T_DOUBLE)
125 ? (Node*)new (C) LoadD_unalignedNode( ctl, mem, adr, TypeRawPtr::BOTTOM )
126 : (Node*)new (C) LoadL_unalignedNode( ctl, mem, adr, TypeRawPtr::BOTTOM );
127 }
128 break;
129 }
130 default: ShouldNotReachHere();
131 }
132 return _gvn.transform(l);
133 }
134
135 // Helper routine to prevent the interpreter from handing
136 // unexpected typestate to an OSR method.
137 // The Node l is a value newly dug out of the interpreter frame.
138 // The type is the type predicted by ciTypeFlow. Note that it is
139 // not a general type, but can only come from Type::get_typeflow_type.
140 // The safepoint is a map which will feed an uncommon trap.
141 Node* Parse::check_interpreter_type(Node* l, const Type* type,
142 SafePointNode* &bad_type_exit) {
143
144 const TypeOopPtr* tp = type->isa_oopptr();
145
146 // TypeFlow may assert null-ness if a type appears unloaded.
147 if (type == TypePtr::NULL_PTR ||
148 (tp != NULL && !tp->klass()->is_loaded())) {
149 // Value must be null, not a real oop.
150 Node* chk = _gvn.transform( new (C) CmpPNode(l, null()) );
151 Node* tst = _gvn.transform( new (C) BoolNode(chk, BoolTest::eq) );
152 IfNode* iff = create_and_map_if(control(), tst, PROB_MAX, COUNT_UNKNOWN);
153 set_control(_gvn.transform( new (C) IfTrueNode(iff) ));
154 Node* bad_type = _gvn.transform( new (C) IfFalseNode(iff) );
155 bad_type_exit->control()->add_req(bad_type);
156 l = null();
157 }
158
159 // Typeflow can also cut off paths from the CFG, based on
160 // types which appear unloaded, or call sites which appear unlinked.
161 // When paths are cut off, values at later merge points can rise
162 // toward more specific classes. Make sure these specific classes
163 // are still in effect.
164 if (tp != NULL && tp->klass() != C->env()->Object_klass()) {
165 // TypeFlow asserted a specific object type. Value must have that type.
166 Node* bad_type_ctrl = NULL;
167 l = gen_checkcast(l, makecon(TypeKlassPtr::make(tp->klass())), &bad_type_ctrl);
168 bad_type_exit->control()->add_req(bad_type_ctrl);
169 }
170
171 BasicType bt_l = _gvn.type(l)->basic_type();
172 BasicType bt_t = type->basic_type();
173 assert(_gvn.type(l)->higher_equal(type), "must constrain OSR typestate");
174 return l;
175 }
176
177 // Helper routine which sets up elements of the initial parser map when
178 // performing a parse for on stack replacement. Add values into map.
179 // The only parameter contains the address of a interpreter arguments.
180 void Parse::load_interpreter_state(Node* osr_buf) {
181 int index;
182 int max_locals = jvms()->loc_size();
183 int max_stack = jvms()->stk_size();
184
185
186 // Mismatch between method and jvms can occur since map briefly held
187 // an OSR entry state (which takes up one RawPtr word).
188 assert(max_locals == method()->max_locals(), "sanity");
189 assert(max_stack >= method()->max_stack(), "sanity");
190 assert((int)jvms()->endoff() == TypeFunc::Parms + max_locals + max_stack, "sanity");
191 assert((int)jvms()->endoff() == (int)map()->req(), "sanity");
192
193 // Find the start block.
194 Block* osr_block = start_block();
195 assert(osr_block->start() == osr_bci(), "sanity");
196
197 // Set initial BCI.
198 set_parse_bci(osr_block->start());
199
200 // Set initial stack depth.
201 set_sp(osr_block->start_sp());
202
203 // Check bailouts. We currently do not perform on stack replacement
204 // of loops in catch blocks or loops which branch with a non-empty stack.
205 if (sp() != 0) {
206 C->record_method_not_compilable("OSR starts with non-empty stack");
207 return;
208 }
209 // Do not OSR inside finally clauses:
210 if (osr_block->has_trap_at(osr_block->start())) {
211 C->record_method_not_compilable("OSR starts with an immediate trap");
212 return;
213 }
214
215 // Commute monitors from interpreter frame to compiler frame.
216 assert(jvms()->monitor_depth() == 0, "should be no active locks at beginning of osr");
217 int mcnt = osr_block->flow()->monitor_count();
218 Node *monitors_addr = basic_plus_adr(osr_buf, osr_buf, (max_locals+mcnt*2-1)*wordSize);
219 for (index = 0; index < mcnt; index++) {
220 // Make a BoxLockNode for the monitor.
221 Node *box = _gvn.transform(new (C) BoxLockNode(next_monitor()));
222
223
224 // Displaced headers and locked objects are interleaved in the
225 // temp OSR buffer. We only copy the locked objects out here.
226 // Fetch the locked object from the OSR temp buffer and copy to our fastlock node.
227 Node *lock_object = fetch_interpreter_state(index*2, T_OBJECT, monitors_addr, osr_buf);
228 // Try and copy the displaced header to the BoxNode
229 Node *displaced_hdr = fetch_interpreter_state((index*2) + 1, T_ADDRESS, monitors_addr, osr_buf);
230
231
232 store_to_memory(control(), box, displaced_hdr, T_ADDRESS, Compile::AliasIdxRaw);
233
234 // Build a bogus FastLockNode (no code will be generated) and push the
235 // monitor into our debug info.
236 const FastLockNode *flock = _gvn.transform(new (C) FastLockNode( 0, lock_object, box ))->as_FastLock();
237 map()->push_monitor(flock);
238
239 // If the lock is our method synchronization lock, tuck it away in
240 // _sync_lock for return and rethrow exit paths.
241 if (index == 0 && method()->is_synchronized()) {
242 _synch_lock = flock;
243 }
244 }
245
246 // Use the raw liveness computation to make sure that unexpected
247 // values don't propagate into the OSR frame.
248 MethodLivenessResult live_locals = method()->liveness_at_bci(osr_bci());
249 if (!live_locals.is_valid()) {
250 // Degenerate or breakpointed method.
251 C->record_method_not_compilable("OSR in empty or breakpointed method");
252 return;
253 }
254
255 // Extract the needed locals from the interpreter frame.
256 Node *locals_addr = basic_plus_adr(osr_buf, osr_buf, (max_locals-1)*wordSize);
257
258 // find all the locals that the interpreter thinks contain live oops
259 const BitMap live_oops = method()->live_local_oops_at_bci(osr_bci());
260 for (index = 0; index < max_locals; index++) {
261
262 if (!live_locals.at(index)) {
263 continue;
264 }
265
266 const Type *type = osr_block->local_type_at(index);
267
268 if (type->isa_oopptr() != NULL) {
269
270 // 6403625: Verify that the interpreter oopMap thinks that the oop is live
271 // else we might load a stale oop if the MethodLiveness disagrees with the
272 // result of the interpreter. If the interpreter says it is dead we agree
273 // by making the value go to top.
274 //
275
276 if (!live_oops.at(index)) {
277 if (C->log() != NULL) {
278 C->log()->elem("OSR_mismatch local_index='%d'",index);
279 }
280 set_local(index, null());
281 // and ignore it for the loads
282 continue;
283 }
284 }
285
286 // Filter out TOP, HALF, and BOTTOM. (Cf. ensure_phi.)
287 if (type == Type::TOP || type == Type::HALF) {
288 continue;
289 }
290 // If the type falls to bottom, then this must be a local that
291 // is mixing ints and oops or some such. Forcing it to top
292 // makes it go dead.
293 if (type == Type::BOTTOM) {
294 continue;
295 }
296 // Construct code to access the appropriate local.
297 BasicType bt = type->basic_type();
298 if (type == TypePtr::NULL_PTR) {
299 // Ptr types are mixed together with T_ADDRESS but NULL is
300 // really for T_OBJECT types so correct it.
301 bt = T_OBJECT;
302 }
303 Node *value = fetch_interpreter_state(index, bt, locals_addr, osr_buf);
304 set_local(index, value);
305 }
306
307 // Extract the needed stack entries from the interpreter frame.
308 for (index = 0; index < sp(); index++) {
309 const Type *type = osr_block->stack_type_at(index);
310 if (type != Type::TOP) {
311 // Currently the compiler bails out when attempting to on stack replace
312 // at a bci with a non-empty stack. We should not reach here.
313 ShouldNotReachHere();
314 }
315 }
316
317 // End the OSR migration
318 make_runtime_call(RC_LEAF, OptoRuntime::osr_end_Type(),
319 CAST_FROM_FN_PTR(address, SharedRuntime::OSR_migration_end),
320 "OSR_migration_end", TypeRawPtr::BOTTOM,
321 osr_buf);
322
323 // Now that the interpreter state is loaded, make sure it will match
324 // at execution time what the compiler is expecting now:
325 SafePointNode* bad_type_exit = clone_map();
326 bad_type_exit->set_control(new (C) RegionNode(1));
327
328 assert(osr_block->flow()->jsrs()->size() == 0, "should be no jsrs live at osr point");
329 for (index = 0; index < max_locals; index++) {
330 if (stopped()) break;
331 Node* l = local(index);
332 if (l->is_top()) continue; // nothing here
333 const Type *type = osr_block->local_type_at(index);
334 if (type->isa_oopptr() != NULL) {
335 if (!live_oops.at(index)) {
336 // skip type check for dead oops
337 continue;
338 }
339 }
340 if (osr_block->flow()->local_type_at(index)->is_return_address()) {
341 // In our current system it's illegal for jsr addresses to be
342 // live into an OSR entry point because the compiler performs
343 // inlining of jsrs. ciTypeFlow has a bailout that detect this
344 // case and aborts the compile if addresses are live into an OSR
345 // entry point. Because of that we can assume that any address
346 // locals at the OSR entry point are dead. Method liveness
347 // isn't precise enought to figure out that they are dead in all
348 // cases so simply skip checking address locals all
349 // together. Any type check is guaranteed to fail since the
350 // interpreter type is the result of a load which might have any
351 // value and the expected type is a constant.
352 continue;
353 }
354 set_local(index, check_interpreter_type(l, type, bad_type_exit));
355 }
356
357 for (index = 0; index < sp(); index++) {
358 if (stopped()) break;
359 Node* l = stack(index);
360 if (l->is_top()) continue; // nothing here
361 const Type *type = osr_block->stack_type_at(index);
362 set_stack(index, check_interpreter_type(l, type, bad_type_exit));
363 }
364
365 if (bad_type_exit->control()->req() > 1) {
366 // Build an uncommon trap here, if any inputs can be unexpected.
367 bad_type_exit->set_control(_gvn.transform( bad_type_exit->control() ));
368 record_for_igvn(bad_type_exit->control());
369 SafePointNode* types_are_good = map();
370 set_map(bad_type_exit);
371 // The unexpected type happens because a new edge is active
372 // in the CFG, which typeflow had previously ignored.
373 // E.g., Object x = coldAtFirst() && notReached()? "str": new Integer(123).
374 // This x will be typed as Integer if notReached is not yet linked.
375 // It could also happen due to a problem in ciTypeFlow analysis.
376 uncommon_trap(Deoptimization::Reason_constraint,
377 Deoptimization::Action_reinterpret);
378 set_map(types_are_good);
379 }
380 }
381
382 //------------------------------Parse------------------------------------------
383 // Main parser constructor.
384 Parse::Parse(JVMState* caller, ciMethod* parse_method, float expected_uses)
385 : _exits(caller)
386 {
387 // Init some variables
388 _caller = caller;
389 _method = parse_method;
390 _expected_uses = expected_uses;
391 _depth = 1 + (caller->has_method() ? caller->depth() : 0);
392 _wrote_final = false;
393 _entry_bci = InvocationEntryBci;
394 _tf = NULL;
395 _block = NULL;
396 debug_only(_block_count = -1);
397 debug_only(_blocks = (Block*)-1);
398 #ifndef PRODUCT
399 if (PrintCompilation || PrintOpto) {
400 // Make sure I have an inline tree, so I can print messages about it.
401 JVMState* ilt_caller = is_osr_parse() ? caller->caller() : caller;
402 InlineTree::find_subtree_from_root(C->ilt(), ilt_caller, parse_method);
403 }
404 _max_switch_depth = 0;
405 _est_switch_depth = 0;
406 #endif
407
408 _tf = TypeFunc::make(method());
409 _iter.reset_to_method(method());
410 _flow = method()->get_flow_analysis();
411 if (_flow->failing()) {
412 C->record_method_not_compilable_all_tiers(_flow->failure_reason());
413 }
414
415 #ifndef PRODUCT
416 if (_flow->has_irreducible_entry()) {
417 C->set_parsed_irreducible_loop(true);
418 }
419 #endif
420
421 if (_expected_uses <= 0) {
422 _prof_factor = 1;
423 } else {
424 float prof_total = parse_method->interpreter_invocation_count();
425 if (prof_total <= _expected_uses) {
426 _prof_factor = 1;
427 } else {
428 _prof_factor = _expected_uses / prof_total;
429 }
430 }
431
432 CompileLog* log = C->log();
433 if (log != NULL) {
434 log->begin_head("parse method='%d' uses='%g'",
435 log->identify(parse_method), expected_uses);
436 if (depth() == 1 && C->is_osr_compilation()) {
437 log->print(" osr_bci='%d'", C->entry_bci());
438 }
439 log->stamp();
440 log->end_head();
441 }
442
443 // Accumulate deoptimization counts.
444 // (The range_check and store_check counts are checked elsewhere.)
445 ciMethodData* md = method()->method_data();
446 for (uint reason = 0; reason < md->trap_reason_limit(); reason++) {
447 uint md_count = md->trap_count(reason);
448 if (md_count != 0) {
449 if (md_count == md->trap_count_limit())
450 md_count += md->overflow_trap_count();
451 uint total_count = C->trap_count(reason);
452 uint old_count = total_count;
453 total_count += md_count;
454 // Saturate the add if it overflows.
455 if (total_count < old_count || total_count < md_count)
456 total_count = (uint)-1;
457 C->set_trap_count(reason, total_count);
458 if (log != NULL)
459 log->elem("observe trap='%s' count='%d' total='%d'",
460 Deoptimization::trap_reason_name(reason),
461 md_count, total_count);
462 }
463 }
464 // Accumulate total sum of decompilations, also.
465 C->set_decompile_count(C->decompile_count() + md->decompile_count());
466
467 _count_invocations = C->do_count_invocations();
468 _method_data_update = C->do_method_data_update();
469
470 if (log != NULL && method()->has_exception_handlers()) {
471 log->elem("observe that='has_exception_handlers'");
472 }
473
474 assert(method()->can_be_compiled(), "Can not parse this method, cutout earlier");
475 assert(method()->has_balanced_monitors(), "Can not parse unbalanced monitors, cutout earlier");
476
477 // Always register dependence if JVMTI is enabled, because
478 // either breakpoint setting or hotswapping of methods may
479 // cause deoptimization.
480 if (C->env()->jvmti_can_hotswap_or_post_breakpoint()) {
481 C->dependencies()->assert_evol_method(method());
482 }
483
484 methods_seen++;
485
486 // Do some special top-level things.
487 if (depth() == 1 && C->is_osr_compilation()) {
488 _entry_bci = C->entry_bci();
489 _flow = method()->get_osr_flow_analysis(osr_bci());
490 if (_flow->failing()) {
491 C->record_method_not_compilable(_flow->failure_reason());
492 #ifndef PRODUCT
493 if (PrintOpto && (Verbose || WizardMode)) {
494 tty->print_cr("OSR @%d type flow bailout: %s", _entry_bci, _flow->failure_reason());
495 if (Verbose) {
496 method()->print();
497 method()->print_codes();
498 _flow->print();
499 }
500 }
501 #endif
502 }
503 _tf = C->tf(); // the OSR entry type is different
504 }
505
506 #ifdef ASSERT
507 if (depth() == 1) {
508 assert(C->is_osr_compilation() == this->is_osr_parse(), "OSR in sync");
509 if (C->tf() != tf()) {
510 MutexLockerEx ml(Compile_lock, Mutex::_no_safepoint_check_flag);
511 assert(C->env()->system_dictionary_modification_counter_changed(),
512 "Must invalidate if TypeFuncs differ");
513 }
514 } else {
515 assert(!this->is_osr_parse(), "no recursive OSR");
516 }
517 #endif
518
519 methods_parsed++;
520 #ifndef PRODUCT
521 // add method size here to guarantee that inlined methods are added too
522 if (TimeCompiler)
523 _total_bytes_compiled += method()->code_size();
524
525 show_parse_info();
526 #endif
527
528 if (failing()) {
529 if (log) log->done("parse");
530 return;
531 }
532
533 gvn().set_type(root(), root()->bottom_type());
534 gvn().transform(top());
535
536 // Import the results of the ciTypeFlow.
537 init_blocks();
538
539 // Merge point for all normal exits
540 build_exits();
541
542 // Setup the initial JVM state map.
543 SafePointNode* entry_map = create_entry_map();
544
545 // Check for bailouts during map initialization
546 if (failing() || entry_map == NULL) {
547 if (log) log->done("parse");
548 return;
549 }
550
551 Node_Notes* caller_nn = C->default_node_notes();
552 // Collect debug info for inlined calls unless -XX:-DebugInlinedCalls.
553 if (DebugInlinedCalls || depth() == 1) {
554 C->set_default_node_notes(make_node_notes(caller_nn));
555 }
556
557 if (is_osr_parse()) {
558 Node* osr_buf = entry_map->in(TypeFunc::Parms+0);
559 entry_map->set_req(TypeFunc::Parms+0, top());
560 set_map(entry_map);
561 load_interpreter_state(osr_buf);
562 } else {
563 set_map(entry_map);
564 do_method_entry();
565 }
566
567 // Check for bailouts during method entry.
568 if (failing()) {
569 if (log) log->done("parse");
570 C->set_default_node_notes(caller_nn);
571 return;
572 }
573
574 entry_map = map(); // capture any changes performed by method setup code
575 assert(jvms()->endoff() == map()->req(), "map matches JVMS layout");
576
577 // We begin parsing as if we have just encountered a jump to the
578 // method entry.
579 Block* entry_block = start_block();
580 assert(entry_block->start() == (is_osr_parse() ? osr_bci() : 0), "");
581 set_map_clone(entry_map);
582 merge_common(entry_block, entry_block->next_path_num());
583
584 #ifndef PRODUCT
585 BytecodeParseHistogram *parse_histogram_obj = new (C->env()->arena()) BytecodeParseHistogram(this, C);
586 set_parse_histogram( parse_histogram_obj );
587 #endif
588
589 // Parse all the basic blocks.
590 do_all_blocks();
591
592 C->set_default_node_notes(caller_nn);
593
594 // Check for bailouts during conversion to graph
595 if (failing()) {
596 if (log) log->done("parse");
597 return;
598 }
599
600 // Fix up all exiting control flow.
601 set_map(entry_map);
602 do_exits();
603
604 if (log) log->done("parse nodes='%d' memory='%d'",
605 C->unique(), C->node_arena()->used());
606 }
607
608 //---------------------------do_all_blocks-------------------------------------
609 void Parse::do_all_blocks() {
610 bool has_irreducible = flow()->has_irreducible_entry();
611
612 // Walk over all blocks in Reverse Post-Order.
613 while (true) {
614 bool progress = false;
615 for (int rpo = 0; rpo < block_count(); rpo++) {
616 Block* block = rpo_at(rpo);
617
618 if (block->is_parsed()) continue;
619
620 if (!block->is_merged()) {
621 // Dead block, no state reaches this block
622 continue;
623 }
624
625 // Prepare to parse this block.
626 load_state_from(block);
627
628 if (stopped()) {
629 // Block is dead.
630 continue;
631 }
632
633 blocks_parsed++;
634
635 progress = true;
636 if (block->is_loop_head() || block->is_handler() || has_irreducible && !block->is_ready()) {
637 // Not all preds have been parsed. We must build phis everywhere.
638 // (Note that dead locals do not get phis built, ever.)
639 ensure_phis_everywhere();
640
641 if (block->is_SEL_head() &&
642 (UseLoopPredicate || LoopLimitCheck)) {
643 // Add predicate to single entry (not irreducible) loop head.
644 assert(!block->has_merged_backedge(), "only entry paths should be merged for now");
645 // Need correct bci for predicate.
646 // It is fine to set it here since do_one_block() will set it anyway.
647 set_parse_bci(block->start());
648 add_predicate();
649 // Add new region for back branches.
650 int edges = block->pred_count() - block->preds_parsed() + 1; // +1 for original region
651 RegionNode *r = new (C) RegionNode(edges+1);
652 _gvn.set_type(r, Type::CONTROL);
653 record_for_igvn(r);
654 r->init_req(edges, control());
655 set_control(r);
656 // Add new phis.
657 ensure_phis_everywhere();
658 }
659
660 // Leave behind an undisturbed copy of the map, for future merges.
661 set_map(clone_map());
662 }
663
664 if (control()->is_Region() && !block->is_loop_head() && !has_irreducible && !block->is_handler()) {
665 // In the absence of irreducible loops, the Region and Phis
666 // associated with a merge that doesn't involve a backedge can
667 // be simplified now since the RPO parsing order guarantees
668 // that any path which was supposed to reach here has already
669 // been parsed or must be dead.
670 Node* c = control();
671 Node* result = _gvn.transform_no_reclaim(control());
672 if (c != result && TraceOptoParse) {
673 tty->print_cr("Block #%d replace %d with %d", block->rpo(), c->_idx, result->_idx);
674 }
675 if (result != top()) {
676 record_for_igvn(result);
677 }
678 }
679
680 // Parse the block.
681 do_one_block();
682
683 // Check for bailouts.
684 if (failing()) return;
685 }
686
687 // with irreducible loops multiple passes might be necessary to parse everything
688 if (!has_irreducible || !progress) {
689 break;
690 }
691 }
692
693 blocks_seen += block_count();
694
695 #ifndef PRODUCT
696 // Make sure there are no half-processed blocks remaining.
697 // Every remaining unprocessed block is dead and may be ignored now.
698 for (int rpo = 0; rpo < block_count(); rpo++) {
699 Block* block = rpo_at(rpo);
700 if (!block->is_parsed()) {
701 if (TraceOptoParse) {
702 tty->print_cr("Skipped dead block %d at bci:%d", rpo, block->start());
703 }
704 assert(!block->is_merged(), "no half-processed blocks");
705 }
706 }
707 #endif
708 }
709
710 //-------------------------------build_exits----------------------------------
711 // Build normal and exceptional exit merge points.
712 void Parse::build_exits() {
713 // make a clone of caller to prevent sharing of side-effects
714 _exits.set_map(_exits.clone_map());
715 _exits.clean_stack(_exits.sp());
716 _exits.sync_jvms();
717
718 RegionNode* region = new (C) RegionNode(1);
719 record_for_igvn(region);
720 gvn().set_type_bottom(region);
721 _exits.set_control(region);
722
723 // Note: iophi and memphi are not transformed until do_exits.
724 Node* iophi = new (C) PhiNode(region, Type::ABIO);
725 Node* memphi = new (C) PhiNode(region, Type::MEMORY, TypePtr::BOTTOM);
726 _exits.set_i_o(iophi);
727 _exits.set_all_memory(memphi);
728
729 // Add a return value to the exit state. (Do not push it yet.)
730 if (tf()->range()->cnt() > TypeFunc::Parms) {
731 const Type* ret_type = tf()->range()->field_at(TypeFunc::Parms);
732 // Don't "bind" an unloaded return klass to the ret_phi. If the klass
733 // becomes loaded during the subsequent parsing, the loaded and unloaded
734 // types will not join when we transform and push in do_exits().
735 const TypeOopPtr* ret_oop_type = ret_type->isa_oopptr();
736 if (ret_oop_type && !ret_oop_type->klass()->is_loaded()) {
737 ret_type = TypeOopPtr::BOTTOM;
738 }
739 int ret_size = type2size[ret_type->basic_type()];
740 Node* ret_phi = new (C) PhiNode(region, ret_type);
741 _exits.ensure_stack(ret_size);
742 assert((int)(tf()->range()->cnt() - TypeFunc::Parms) == ret_size, "good tf range");
743 assert(method()->return_type()->size() == ret_size, "tf agrees w/ method");
744 _exits.set_argument(0, ret_phi); // here is where the parser finds it
745 // Note: ret_phi is not yet pushed, until do_exits.
746 }
747 }
748
749
750 //----------------------------build_start_state-------------------------------
751 // Construct a state which contains only the incoming arguments from an
752 // unknown caller. The method & bci will be NULL & InvocationEntryBci.
753 JVMState* Compile::build_start_state(StartNode* start, const TypeFunc* tf) {
754 int arg_size = tf->domain()->cnt();
755 int max_size = MAX2(arg_size, (int)tf->range()->cnt());
756 JVMState* jvms = new (this) JVMState(max_size - TypeFunc::Parms);
757 SafePointNode* map = new (this) SafePointNode(max_size, NULL);
758 record_for_igvn(map);
759 assert(arg_size == TypeFunc::Parms + (is_osr_compilation() ? 1 : method()->arg_size()), "correct arg_size");
760 Node_Notes* old_nn = default_node_notes();
761 if (old_nn != NULL && has_method()) {
762 Node_Notes* entry_nn = old_nn->clone(this);
763 JVMState* entry_jvms = new(this) JVMState(method(), old_nn->jvms());
764 entry_jvms->set_offsets(0);
765 entry_jvms->set_bci(entry_bci());
766 entry_nn->set_jvms(entry_jvms);
767 set_default_node_notes(entry_nn);
768 }
769 uint i;
770 for (i = 0; i < (uint)arg_size; i++) {
771 Node* parm = initial_gvn()->transform(new (this) ParmNode(start, i));
772 map->init_req(i, parm);
773 // Record all these guys for later GVN.
774 record_for_igvn(parm);
775 }
776 for (; i < map->req(); i++) {
777 map->init_req(i, top());
778 }
779 assert(jvms->argoff() == TypeFunc::Parms, "parser gets arguments here");
780 set_default_node_notes(old_nn);
781 map->set_jvms(jvms);
782 jvms->set_map(map);
783 return jvms;
784 }
785
786 //-----------------------------make_node_notes---------------------------------
787 Node_Notes* Parse::make_node_notes(Node_Notes* caller_nn) {
788 if (caller_nn == NULL) return NULL;
789 Node_Notes* nn = caller_nn->clone(C);
790 JVMState* caller_jvms = nn->jvms();
791 JVMState* jvms = new (C) JVMState(method(), caller_jvms);
792 jvms->set_offsets(0);
793 jvms->set_bci(_entry_bci);
794 nn->set_jvms(jvms);
795 return nn;
796 }
797
798
799 //--------------------------return_values--------------------------------------
800 void Compile::return_values(JVMState* jvms) {
801 GraphKit kit(jvms);
802 Node* ret = new (this) ReturnNode(TypeFunc::Parms,
803 kit.control(),
804 kit.i_o(),
805 kit.reset_memory(),
806 kit.frameptr(),
807 kit.returnadr());
808 // Add zero or 1 return values
809 int ret_size = tf()->range()->cnt() - TypeFunc::Parms;
810 if (ret_size > 0) {
811 kit.inc_sp(-ret_size); // pop the return value(s)
812 kit.sync_jvms();
813 ret->add_req(kit.argument(0));
814 // Note: The second dummy edge is not needed by a ReturnNode.
815 }
816 // bind it to root
817 root()->add_req(ret);
818 record_for_igvn(ret);
819 initial_gvn()->transform_no_reclaim(ret);
820 }
821
822 //------------------------rethrow_exceptions-----------------------------------
823 // Bind all exception states in the list into a single RethrowNode.
824 void Compile::rethrow_exceptions(JVMState* jvms) {
825 GraphKit kit(jvms);
826 if (!kit.has_exceptions()) return; // nothing to generate
827 // Load my combined exception state into the kit, with all phis transformed:
828 SafePointNode* ex_map = kit.combine_and_pop_all_exception_states();
829 Node* ex_oop = kit.use_exception_state(ex_map);
830 RethrowNode* exit = new (this) RethrowNode(kit.control(),
831 kit.i_o(), kit.reset_memory(),
832 kit.frameptr(), kit.returnadr(),
833 // like a return but with exception input
834 ex_oop);
835 // bind to root
836 root()->add_req(exit);
837 record_for_igvn(exit);
838 initial_gvn()->transform_no_reclaim(exit);
839 }
840
841 //---------------------------do_exceptions-------------------------------------
842 // Process exceptions arising from the current bytecode.
843 // Send caught exceptions to the proper handler within this method.
844 // Unhandled exceptions feed into _exit.
845 void Parse::do_exceptions() {
846 if (!has_exceptions()) return;
847
848 if (failing()) {
849 // Pop them all off and throw them away.
850 while (pop_exception_state() != NULL) ;
851 return;
852 }
853
854 PreserveJVMState pjvms(this, false);
855
856 SafePointNode* ex_map;
857 while ((ex_map = pop_exception_state()) != NULL) {
858 if (!method()->has_exception_handlers()) {
859 // Common case: Transfer control outward.
860 // Doing it this early allows the exceptions to common up
861 // even between adjacent method calls.
862 throw_to_exit(ex_map);
863 } else {
864 // Have to look at the exception first.
865 assert(stopped(), "catch_inline_exceptions trashes the map");
866 catch_inline_exceptions(ex_map);
867 stop_and_kill_map(); // we used up this exception state; kill it
868 }
869 }
870
871 // We now return to our regularly scheduled program:
872 }
873
874 //---------------------------throw_to_exit-------------------------------------
875 // Merge the given map into an exception exit from this method.
876 // The exception exit will handle any unlocking of receiver.
877 // The ex_oop must be saved within the ex_map, unlike merge_exception.
878 void Parse::throw_to_exit(SafePointNode* ex_map) {
879 // Pop the JVMS to (a copy of) the caller.
880 GraphKit caller;
881 caller.set_map_clone(_caller->map());
882 caller.set_bci(_caller->bci());
883 caller.set_sp(_caller->sp());
884 // Copy out the standard machine state:
885 for (uint i = 0; i < TypeFunc::Parms; i++) {
886 caller.map()->set_req(i, ex_map->in(i));
887 }
888 // ...and the exception:
889 Node* ex_oop = saved_ex_oop(ex_map);
890 SafePointNode* caller_ex_map = caller.make_exception_state(ex_oop);
891 // Finally, collect the new exception state in my exits:
892 _exits.add_exception_state(caller_ex_map);
893 }
894
895 //------------------------------do_exits---------------------------------------
896 void Parse::do_exits() {
897 set_parse_bci(InvocationEntryBci);
898
899 // Now peephole on the return bits
900 Node* region = _exits.control();
901 _exits.set_control(gvn().transform(region));
902
903 Node* iophi = _exits.i_o();
904 _exits.set_i_o(gvn().transform(iophi));
905
906 if (wrote_final()) {
907 // This method (which must be a constructor by the rules of Java)
908 // wrote a final. The effects of all initializations must be
909 // committed to memory before any code after the constructor
910 // publishes the reference to the newly constructor object.
911 // Rather than wait for the publication, we simply block the
912 // writes here. Rather than put a barrier on only those writes
913 // which are required to complete, we force all writes to complete.
914 //
915 // "All bets are off" unless the first publication occurs after a
916 // normal return from the constructor. We do not attempt to detect
917 // such unusual early publications. But no barrier is needed on
918 // exceptional returns, since they cannot publish normally.
919 //
920 _exits.insert_mem_bar(Op_MemBarRelease);
921 #ifndef PRODUCT
922 if (PrintOpto && (Verbose || WizardMode)) {
923 method()->print_name();
924 tty->print_cr(" writes finals and needs a memory barrier");
925 }
926 #endif
927 }
928
929 for (MergeMemStream mms(_exits.merged_memory()); mms.next_non_empty(); ) {
930 // transform each slice of the original memphi:
931 mms.set_memory(_gvn.transform(mms.memory()));
932 }
933
934 if (tf()->range()->cnt() > TypeFunc::Parms) {
935 const Type* ret_type = tf()->range()->field_at(TypeFunc::Parms);
936 Node* ret_phi = _gvn.transform( _exits.argument(0) );
937 assert(_exits.control()->is_top() || !_gvn.type(ret_phi)->empty(), "return value must be well defined");
938 _exits.push_node(ret_type->basic_type(), ret_phi);
939 }
940
941 // Note: Logic for creating and optimizing the ReturnNode is in Compile.
942
943 // Unlock along the exceptional paths.
944 // This is done late so that we can common up equivalent exceptions
945 // (e.g., null checks) arising from multiple points within this method.
946 // See GraphKit::add_exception_state, which performs the commoning.
947 bool do_synch = method()->is_synchronized() && GenerateSynchronizationCode;
948
949 // record exit from a method if compiled while Dtrace is turned on.
950 if (do_synch || C->env()->dtrace_method_probes()) {
951 // First move the exception list out of _exits:
952 GraphKit kit(_exits.transfer_exceptions_into_jvms());
953 SafePointNode* normal_map = kit.map(); // keep this guy safe
954 // Now re-collect the exceptions into _exits:
955 SafePointNode* ex_map;
956 while ((ex_map = kit.pop_exception_state()) != NULL) {
957 Node* ex_oop = kit.use_exception_state(ex_map);
958 // Force the exiting JVM state to have this method at InvocationEntryBci.
959 // The exiting JVM state is otherwise a copy of the calling JVMS.
960 JVMState* caller = kit.jvms();
961 JVMState* ex_jvms = caller->clone_shallow(C);
962 ex_jvms->set_map(kit.clone_map());
963 ex_jvms->map()->set_jvms(ex_jvms);
964 ex_jvms->set_bci( InvocationEntryBci);
965 kit.set_jvms(ex_jvms);
966 if (do_synch) {
967 // Add on the synchronized-method box/object combo
968 kit.map()->push_monitor(_synch_lock);
969 // Unlock!
970 kit.shared_unlock(_synch_lock->box_node(), _synch_lock->obj_node());
971 }
972 if (C->env()->dtrace_method_probes()) {
973 kit.make_dtrace_method_exit(method());
974 }
975 // Done with exception-path processing.
976 ex_map = kit.make_exception_state(ex_oop);
977 assert(ex_jvms->same_calls_as(ex_map->jvms()), "sanity");
978 // Pop the last vestige of this method:
979 ex_map->set_jvms(caller->clone_shallow(C));
980 ex_map->jvms()->set_map(ex_map);
981 _exits.push_exception_state(ex_map);
982 }
983 assert(_exits.map() == normal_map, "keep the same return state");
984 }
985
986 {
987 // Capture very early exceptions (receiver null checks) from caller JVMS
988 GraphKit caller(_caller);
989 SafePointNode* ex_map;
990 while ((ex_map = caller.pop_exception_state()) != NULL) {
991 _exits.add_exception_state(ex_map);
992 }
993 }
994 }
995
996 //-----------------------------create_entry_map-------------------------------
997 // Initialize our parser map to contain the types at method entry.
998 // For OSR, the map contains a single RawPtr parameter.
999 // Initial monitor locking for sync. methods is performed by do_method_entry.
1000 SafePointNode* Parse::create_entry_map() {
1001 // Check for really stupid bail-out cases.
1002 uint len = TypeFunc::Parms + method()->max_locals() + method()->max_stack();
1003 if (len >= 32760) {
1004 C->record_method_not_compilable_all_tiers("too many local variables");
1005 return NULL;
1006 }
1007
1008 // If this is an inlined method, we may have to do a receiver null check.
1009 if (_caller->has_method() && is_normal_parse() && !method()->is_static()) {
1010 GraphKit kit(_caller);
1011 kit.null_check_receiver_before_call(method());
1012 _caller = kit.transfer_exceptions_into_jvms();
1013 if (kit.stopped()) {
1014 _exits.add_exception_states_from(_caller);
1015 _exits.set_jvms(_caller);
1016 return NULL;
1017 }
1018 }
1019
1020 assert(method() != NULL, "parser must have a method");
1021
1022 // Create an initial safepoint to hold JVM state during parsing
1023 JVMState* jvms = new (C) JVMState(method(), _caller->has_method() ? _caller : NULL);
1024 set_map(new (C) SafePointNode(len, jvms));
1025 jvms->set_map(map());
1026 record_for_igvn(map());
1027 assert(jvms->endoff() == len, "correct jvms sizing");
1028
1029 SafePointNode* inmap = _caller->map();
1030 assert(inmap != NULL, "must have inmap");
1031
1032 uint i;
1033
1034 // Pass thru the predefined input parameters.
1035 for (i = 0; i < TypeFunc::Parms; i++) {
1036 map()->init_req(i, inmap->in(i));
1037 }
1038
1039 if (depth() == 1) {
1040 assert(map()->memory()->Opcode() == Op_Parm, "");
1041 // Insert the memory aliasing node
1042 set_all_memory(reset_memory());
1043 }
1044 assert(merged_memory(), "");
1045
1046 // Now add the locals which are initially bound to arguments:
1047 uint arg_size = tf()->domain()->cnt();
1048 ensure_stack(arg_size - TypeFunc::Parms); // OSR methods have funny args
1049 for (i = TypeFunc::Parms; i < arg_size; i++) {
1050 map()->init_req(i, inmap->argument(_caller, i - TypeFunc::Parms));
1051 }
1052
1053 // Clear out the rest of the map (locals and stack)
1054 for (i = arg_size; i < len; i++) {
1055 map()->init_req(i, top());
1056 }
1057
1058 SafePointNode* entry_map = stop();
1059 return entry_map;
1060 }
1061
1062 //-----------------------------do_method_entry--------------------------------
1063 // Emit any code needed in the pseudo-block before BCI zero.
1064 // The main thing to do is lock the receiver of a synchronized method.
1065 void Parse::do_method_entry() {
1066 set_parse_bci(InvocationEntryBci); // Pseudo-BCP
1067 set_sp(0); // Java Stack Pointer
1068
1069 NOT_PRODUCT( count_compiled_calls(true/*at_method_entry*/, false/*is_inline*/); )
1070
1071 if (C->env()->dtrace_method_probes()) {
1072 make_dtrace_method_entry(method());
1073 }
1074
1075 // If the method is synchronized, we need to construct a lock node, attach
1076 // it to the Start node, and pin it there.
1077 if (method()->is_synchronized()) {
1078 // Insert a FastLockNode right after the Start which takes as arguments
1079 // the current thread pointer, the "this" pointer & the address of the
1080 // stack slot pair used for the lock. The "this" pointer is a projection
1081 // off the start node, but the locking spot has to be constructed by
1082 // creating a ConLNode of 0, and boxing it with a BoxLockNode. The BoxLockNode
1083 // becomes the second argument to the FastLockNode call. The
1084 // FastLockNode becomes the new control parent to pin it to the start.
1085
1086 // Setup Object Pointer
1087 Node *lock_obj = NULL;
1088 if(method()->is_static()) {
1089 ciInstance* mirror = _method->holder()->java_mirror();
1090 const TypeInstPtr *t_lock = TypeInstPtr::make(mirror);
1091 lock_obj = makecon(t_lock);
1092 } else { // Else pass the "this" pointer,
1093 lock_obj = local(0); // which is Parm0 from StartNode
1094 }
1095 // Clear out dead values from the debug info.
1096 kill_dead_locals();
1097 // Build the FastLockNode
1098 _synch_lock = shared_lock(lock_obj);
1099 }
1100
1101 if (depth() == 1) {
1102 increment_and_test_invocation_counter(Tier2CompileThreshold);
1103 }
1104 }
1105
1106 //------------------------------init_blocks------------------------------------
1107 // Initialize our parser map to contain the types/monitors at method entry.
1108 void Parse::init_blocks() {
1109 // Create the blocks.
1110 _block_count = flow()->block_count();
1111 _blocks = NEW_RESOURCE_ARRAY(Block, _block_count);
1112 Copy::zero_to_bytes(_blocks, sizeof(Block)*_block_count);
1113
1114 int rpo;
1115
1116 // Initialize the structs.
1117 for (rpo = 0; rpo < block_count(); rpo++) {
1118 Block* block = rpo_at(rpo);
1119 block->init_node(this, rpo);
1120 }
1121
1122 // Collect predecessor and successor information.
1123 for (rpo = 0; rpo < block_count(); rpo++) {
1124 Block* block = rpo_at(rpo);
1125 block->init_graph(this);
1126 }
1127 }
1128
1129 //-------------------------------init_node-------------------------------------
1130 void Parse::Block::init_node(Parse* outer, int rpo) {
1131 _flow = outer->flow()->rpo_at(rpo);
1132 _pred_count = 0;
1133 _preds_parsed = 0;
1134 _count = 0;
1135 assert(pred_count() == 0 && preds_parsed() == 0, "sanity");
1136 assert(!(is_merged() || is_parsed() || is_handler() || has_merged_backedge()), "sanity");
1137 assert(_live_locals.size() == 0, "sanity");
1138
1139 // entry point has additional predecessor
1140 if (flow()->is_start()) _pred_count++;
1141 assert(flow()->is_start() == (this == outer->start_block()), "");
1142 }
1143
1144 //-------------------------------init_graph------------------------------------
1145 void Parse::Block::init_graph(Parse* outer) {
1146 // Create the successor list for this parser block.
1147 GrowableArray<ciTypeFlow::Block*>* tfs = flow()->successors();
1148 GrowableArray<ciTypeFlow::Block*>* tfe = flow()->exceptions();
1149 int ns = tfs->length();
1150 int ne = tfe->length();
1151 _num_successors = ns;
1152 _all_successors = ns+ne;
1153 _successors = (ns+ne == 0) ? NULL : NEW_RESOURCE_ARRAY(Block*, ns+ne);
1154 int p = 0;
1155 for (int i = 0; i < ns+ne; i++) {
1156 ciTypeFlow::Block* tf2 = (i < ns) ? tfs->at(i) : tfe->at(i-ns);
1157 Block* block2 = outer->rpo_at(tf2->rpo());
1158 _successors[i] = block2;
1159
1160 // Accumulate pred info for the other block, too.
1161 if (i < ns) {
1162 block2->_pred_count++;
1163 } else {
1164 block2->_is_handler = true;
1165 }
1166
1167 #ifdef ASSERT
1168 // A block's successors must be distinguishable by BCI.
1169 // That is, no bytecode is allowed to branch to two different
1170 // clones of the same code location.
1171 for (int j = 0; j < i; j++) {
1172 Block* block1 = _successors[j];
1173 if (block1 == block2) continue; // duplicates are OK
1174 assert(block1->start() != block2->start(), "successors have unique bcis");
1175 }
1176 #endif
1177 }
1178
1179 // Note: We never call next_path_num along exception paths, so they
1180 // never get processed as "ready". Also, the input phis of exception
1181 // handlers get specially processed, so that
1182 }
1183
1184 //---------------------------successor_for_bci---------------------------------
1185 Parse::Block* Parse::Block::successor_for_bci(int bci) {
1186 for (int i = 0; i < all_successors(); i++) {
1187 Block* block2 = successor_at(i);
1188 if (block2->start() == bci) return block2;
1189 }
1190 // We can actually reach here if ciTypeFlow traps out a block
1191 // due to an unloaded class, and concurrently with compilation the
1192 // class is then loaded, so that a later phase of the parser is
1193 // able to see more of the bytecode CFG. Or, the flow pass and
1194 // the parser can have a minor difference of opinion about executability
1195 // of bytecodes. For example, "obj.field = null" is executable even
1196 // if the field's type is an unloaded class; the flow pass used to
1197 // make a trap for such code.
1198 return NULL;
1199 }
1200
1201
1202 //-----------------------------stack_type_at-----------------------------------
1203 const Type* Parse::Block::stack_type_at(int i) const {
1204 return get_type(flow()->stack_type_at(i));
1205 }
1206
1207
1208 //-----------------------------local_type_at-----------------------------------
1209 const Type* Parse::Block::local_type_at(int i) const {
1210 // Make dead locals fall to bottom.
1211 if (_live_locals.size() == 0) {
1212 MethodLivenessResult live_locals = flow()->outer()->method()->liveness_at_bci(start());
1213 // This bitmap can be zero length if we saw a breakpoint.
1214 // In such cases, pretend they are all live.
1215 ((Block*)this)->_live_locals = live_locals;
1216 }
1217 if (_live_locals.size() > 0 && !_live_locals.at(i))
1218 return Type::BOTTOM;
1219
1220 return get_type(flow()->local_type_at(i));
1221 }
1222
1223
1224 #ifndef PRODUCT
1225
1226 //----------------------------name_for_bc--------------------------------------
1227 // helper method for BytecodeParseHistogram
1228 static const char* name_for_bc(int i) {
1229 return Bytecodes::is_defined(i) ? Bytecodes::name(Bytecodes::cast(i)) : "xxxunusedxxx";
1230 }
1231
1232 //----------------------------BytecodeParseHistogram------------------------------------
1233 Parse::BytecodeParseHistogram::BytecodeParseHistogram(Parse *p, Compile *c) {
1234 _parser = p;
1235 _compiler = c;
1236 if( ! _initialized ) { _initialized = true; reset(); }
1237 }
1238
1239 //----------------------------current_count------------------------------------
1240 int Parse::BytecodeParseHistogram::current_count(BPHType bph_type) {
1241 switch( bph_type ) {
1242 case BPH_transforms: { return _parser->gvn().made_progress(); }
1243 case BPH_values: { return _parser->gvn().made_new_values(); }
1244 default: { ShouldNotReachHere(); return 0; }
1245 }
1246 }
1247
1248 //----------------------------initialized--------------------------------------
1249 bool Parse::BytecodeParseHistogram::initialized() { return _initialized; }
1250
1251 //----------------------------reset--------------------------------------------
1252 void Parse::BytecodeParseHistogram::reset() {
1253 int i = Bytecodes::number_of_codes;
1254 while (i-- > 0) { _bytecodes_parsed[i] = 0; _nodes_constructed[i] = 0; _nodes_transformed[i] = 0; _new_values[i] = 0; }
1255 }
1256
1257 //----------------------------set_initial_state--------------------------------
1258 // Record info when starting to parse one bytecode
1259 void Parse::BytecodeParseHistogram::set_initial_state( Bytecodes::Code bc ) {
1260 if( PrintParseStatistics && !_parser->is_osr_parse() ) {
1261 _initial_bytecode = bc;
1262 _initial_node_count = _compiler->unique();
1263 _initial_transforms = current_count(BPH_transforms);
1264 _initial_values = current_count(BPH_values);
1265 }
1266 }
1267
1268 //----------------------------record_change--------------------------------
1269 // Record results of parsing one bytecode
1270 void Parse::BytecodeParseHistogram::record_change() {
1271 if( PrintParseStatistics && !_parser->is_osr_parse() ) {
1272 ++_bytecodes_parsed[_initial_bytecode];
1273 _nodes_constructed [_initial_bytecode] += (_compiler->unique() - _initial_node_count);
1274 _nodes_transformed [_initial_bytecode] += (current_count(BPH_transforms) - _initial_transforms);
1275 _new_values [_initial_bytecode] += (current_count(BPH_values) - _initial_values);
1276 }
1277 }
1278
1279
1280 //----------------------------print--------------------------------------------
1281 void Parse::BytecodeParseHistogram::print(float cutoff) {
1282 ResourceMark rm;
1283 // print profile
1284 int total = 0;
1285 int i = 0;
1286 for( i = 0; i < Bytecodes::number_of_codes; ++i ) { total += _bytecodes_parsed[i]; }
1287 int abs_sum = 0;
1288 tty->cr(); //0123456789012345678901234567890123456789012345678901234567890123456789
1289 tty->print_cr("Histogram of %d parsed bytecodes:", total);
1290 if( total == 0 ) { return; }
1291 tty->cr();
1292 tty->print_cr("absolute: count of compiled bytecodes of this type");
1293 tty->print_cr("relative: percentage contribution to compiled nodes");
1294 tty->print_cr("nodes : Average number of nodes constructed per bytecode");
1295 tty->print_cr("rnodes : Significance towards total nodes constructed, (nodes*relative)");
1296 tty->print_cr("transforms: Average amount of tranform progress per bytecode compiled");
1297 tty->print_cr("values : Average number of node values improved per bytecode");
1298 tty->print_cr("name : Bytecode name");
1299 tty->cr();
1300 tty->print_cr(" absolute relative nodes rnodes transforms values name");
1301 tty->print_cr("----------------------------------------------------------------------");
1302 while (--i > 0) {
1303 int abs = _bytecodes_parsed[i];
1304 float rel = abs * 100.0F / total;
1305 float nodes = _bytecodes_parsed[i] == 0 ? 0 : (1.0F * _nodes_constructed[i])/_bytecodes_parsed[i];
1306 float rnodes = _bytecodes_parsed[i] == 0 ? 0 : rel * nodes;
1307 float xforms = _bytecodes_parsed[i] == 0 ? 0 : (1.0F * _nodes_transformed[i])/_bytecodes_parsed[i];
1308 float values = _bytecodes_parsed[i] == 0 ? 0 : (1.0F * _new_values [i])/_bytecodes_parsed[i];
1309 if (cutoff <= rel) {
1310 tty->print_cr("%10d %7.2f%% %6.1f %6.2f %6.1f %6.1f %s", abs, rel, nodes, rnodes, xforms, values, name_for_bc(i));
1311 abs_sum += abs;
1312 }
1313 }
1314 tty->print_cr("----------------------------------------------------------------------");
1315 float rel_sum = abs_sum * 100.0F / total;
1316 tty->print_cr("%10d %7.2f%% (cutoff = %.2f%%)", abs_sum, rel_sum, cutoff);
1317 tty->print_cr("----------------------------------------------------------------------");
1318 tty->cr();
1319 }
1320 #endif
1321
1322 //----------------------------load_state_from----------------------------------
1323 // Load block/map/sp. But not do not touch iter/bci.
1324 void Parse::load_state_from(Block* block) {
1325 set_block(block);
1326 // load the block's JVM state:
1327 set_map(block->start_map());
1328 set_sp( block->start_sp());
1329 }
1330
1331
1332 //-----------------------------record_state------------------------------------
1333 void Parse::Block::record_state(Parse* p) {
1334 assert(!is_merged(), "can only record state once, on 1st inflow");
1335 assert(start_sp() == p->sp(), "stack pointer must agree with ciTypeFlow");
1336 set_start_map(p->stop());
1337 }
1338
1339
1340 //------------------------------do_one_block-----------------------------------
1341 void Parse::do_one_block() {
1342 if (TraceOptoParse) {
1343 Block *b = block();
1344 int ns = b->num_successors();
1345 int nt = b->all_successors();
1346
1347 tty->print("Parsing block #%d at bci [%d,%d), successors: ",
1348 block()->rpo(), block()->start(), block()->limit());
1349 for (int i = 0; i < nt; i++) {
1350 tty->print((( i < ns) ? " %d" : " %d(e)"), b->successor_at(i)->rpo());
1351 }
1352 if (b->is_loop_head()) tty->print(" lphd");
1353 tty->print_cr("");
1354 }
1355
1356 assert(block()->is_merged(), "must be merged before being parsed");
1357 block()->mark_parsed();
1358 ++_blocks_parsed;
1359
1360 // Set iterator to start of block.
1361 iter().reset_to_bci(block()->start());
1362
1363 CompileLog* log = C->log();
1364
1365 // Parse bytecodes
1366 while (!stopped() && !failing()) {
1367 iter().next();
1368
1369 // Learn the current bci from the iterator:
1370 set_parse_bci(iter().cur_bci());
1371
1372 if (bci() == block()->limit()) {
1373 // Do not walk into the next block until directed by do_all_blocks.
1374 merge(bci());
1375 break;
1376 }
1377 assert(bci() < block()->limit(), "bci still in block");
1378
1379 if (log != NULL) {
1380 // Output an optional context marker, to help place actions
1381 // that occur during parsing of this BC. If there is no log
1382 // output until the next context string, this context string
1383 // will be silently ignored.
1384 log->set_context("bc code='%d' bci='%d'", (int)bc(), bci());
1385 }
1386
1387 if (block()->has_trap_at(bci())) {
1388 // We must respect the flow pass's traps, because it will refuse
1389 // to produce successors for trapping blocks.
1390 int trap_index = block()->flow()->trap_index();
1391 assert(trap_index != 0, "trap index must be valid");
1392 uncommon_trap(trap_index);
1393 break;
1394 }
1395
1396 NOT_PRODUCT( parse_histogram()->set_initial_state(bc()); );
1397
1398 #ifdef ASSERT
1399 int pre_bc_sp = sp();
1400 int inputs, depth;
1401 bool have_se = !stopped() && compute_stack_effects(inputs, depth);
1402 assert(!have_se || pre_bc_sp >= inputs, err_msg_res("have enough stack to execute this BC: pre_bc_sp=%d, inputs=%d", pre_bc_sp, inputs));
1403 #endif //ASSERT
1404
1405 do_one_bytecode();
1406
1407 assert(!have_se || stopped() || failing() || (sp() - pre_bc_sp) == depth, "correct depth prediction");
1408
1409 do_exceptions();
1410
1411 NOT_PRODUCT( parse_histogram()->record_change(); );
1412
1413 if (log != NULL)
1414 log->clear_context(); // skip marker if nothing was printed
1415
1416 // Fall into next bytecode. Each bytecode normally has 1 sequential
1417 // successor which is typically made ready by visiting this bytecode.
1418 // If the successor has several predecessors, then it is a merge
1419 // point, starts a new basic block, and is handled like other basic blocks.
1420 }
1421 }
1422
1423
1424 //------------------------------merge------------------------------------------
1425 void Parse::set_parse_bci(int bci) {
1426 set_bci(bci);
1427 Node_Notes* nn = C->default_node_notes();
1428 if (nn == NULL) return;
1429
1430 // Collect debug info for inlined calls unless -XX:-DebugInlinedCalls.
1431 if (!DebugInlinedCalls && depth() > 1) {
1432 return;
1433 }
1434
1435 // Update the JVMS annotation, if present.
1436 JVMState* jvms = nn->jvms();
1437 if (jvms != NULL && jvms->bci() != bci) {
1438 // Update the JVMS.
1439 jvms = jvms->clone_shallow(C);
1440 jvms->set_bci(bci);
1441 nn->set_jvms(jvms);
1442 }
1443 }
1444
1445 //------------------------------merge------------------------------------------
1446 // Merge the current mapping into the basic block starting at bci
1447 void Parse::merge(int target_bci) {
1448 Block* target = successor_for_bci(target_bci);
1449 if (target == NULL) { handle_missing_successor(target_bci); return; }
1450 assert(!target->is_ready(), "our arrival must be expected");
1451 int pnum = target->next_path_num();
1452 merge_common(target, pnum);
1453 }
1454
1455 //-------------------------merge_new_path--------------------------------------
1456 // Merge the current mapping into the basic block, using a new path
1457 void Parse::merge_new_path(int target_bci) {
1458 Block* target = successor_for_bci(target_bci);
1459 if (target == NULL) { handle_missing_successor(target_bci); return; }
1460 assert(!target->is_ready(), "new path into frozen graph");
1461 int pnum = target->add_new_path();
1462 merge_common(target, pnum);
1463 }
1464
1465 //-------------------------merge_exception-------------------------------------
1466 // Merge the current mapping into the basic block starting at bci
1467 // The ex_oop must be pushed on the stack, unlike throw_to_exit.
1468 void Parse::merge_exception(int target_bci) {
1469 assert(sp() == 1, "must have only the throw exception on the stack");
1470 Block* target = successor_for_bci(target_bci);
1471 if (target == NULL) { handle_missing_successor(target_bci); return; }
1472 assert(target->is_handler(), "exceptions are handled by special blocks");
1473 int pnum = target->add_new_path();
1474 merge_common(target, pnum);
1475 }
1476
1477 //--------------------handle_missing_successor---------------------------------
1478 void Parse::handle_missing_successor(int target_bci) {
1479 #ifndef PRODUCT
1480 Block* b = block();
1481 int trap_bci = b->flow()->has_trap()? b->flow()->trap_bci(): -1;
1482 tty->print_cr("### Missing successor at bci:%d for block #%d (trap_bci:%d)", target_bci, b->rpo(), trap_bci);
1483 #endif
1484 ShouldNotReachHere();
1485 }
1486
1487 //--------------------------merge_common---------------------------------------
1488 void Parse::merge_common(Parse::Block* target, int pnum) {
1489 if (TraceOptoParse) {
1490 tty->print("Merging state at block #%d bci:%d", target->rpo(), target->start());
1491 }
1492
1493 // Zap extra stack slots to top
1494 assert(sp() == target->start_sp(), "");
1495 clean_stack(sp());
1496
1497 if (!target->is_merged()) { // No prior mapping at this bci
1498 if (TraceOptoParse) { tty->print(" with empty state"); }
1499
1500 // If this path is dead, do not bother capturing it as a merge.
1501 // It is "as if" we had 1 fewer predecessors from the beginning.
1502 if (stopped()) {
1503 if (TraceOptoParse) tty->print_cr(", but path is dead and doesn't count");
1504 return;
1505 }
1506
1507 // Record that a new block has been merged.
1508 ++_blocks_merged;
1509
1510 // Make a region if we know there are multiple or unpredictable inputs.
1511 // (Also, if this is a plain fall-through, we might see another region,
1512 // which must not be allowed into this block's map.)
1513 if (pnum > PhiNode::Input // Known multiple inputs.
1514 || target->is_handler() // These have unpredictable inputs.
1515 || target->is_loop_head() // Known multiple inputs
1516 || control()->is_Region()) { // We must hide this guy.
1517
1518 int current_bci = bci();
1519 set_parse_bci(target->start()); // Set target bci
1520 if (target->is_SEL_head()) {
1521 DEBUG_ONLY( target->mark_merged_backedge(block()); )
1522 if (target->start() == 0) {
1523 // Add loop predicate for the special case when
1524 // there are backbranches to the method entry.
1525 add_predicate();
1526 }
1527 }
1528 // Add a Region to start the new basic block. Phis will be added
1529 // later lazily.
1530 int edges = target->pred_count();
1531 if (edges < pnum) edges = pnum; // might be a new path!
1532 RegionNode *r = new (C) RegionNode(edges+1);
1533 gvn().set_type(r, Type::CONTROL);
1534 record_for_igvn(r);
1535 // zap all inputs to NULL for debugging (done in Node(uint) constructor)
1536 // for (int j = 1; j < edges+1; j++) { r->init_req(j, NULL); }
1537 r->init_req(pnum, control());
1538 set_control(r);
1539 set_parse_bci(current_bci); // Restore bci
1540 }
1541
1542 // Convert the existing Parser mapping into a mapping at this bci.
1543 store_state_to(target);
1544 assert(target->is_merged(), "do not come here twice");
1545
1546 } else { // Prior mapping at this bci
1547 if (TraceOptoParse) { tty->print(" with previous state"); }
1548 #ifdef ASSERT
1549 if (target->is_SEL_head()) {
1550 target->mark_merged_backedge(block());
1551 }
1552 #endif
1553 // We must not manufacture more phis if the target is already parsed.
1554 bool nophi = target->is_parsed();
1555
1556 SafePointNode* newin = map();// Hang on to incoming mapping
1557 Block* save_block = block(); // Hang on to incoming block;
1558 load_state_from(target); // Get prior mapping
1559
1560 assert(newin->jvms()->locoff() == jvms()->locoff(), "JVMS layouts agree");
1561 assert(newin->jvms()->stkoff() == jvms()->stkoff(), "JVMS layouts agree");
1562 assert(newin->jvms()->monoff() == jvms()->monoff(), "JVMS layouts agree");
1563 assert(newin->jvms()->endoff() == jvms()->endoff(), "JVMS layouts agree");
1564
1565 // Iterate over my current mapping and the old mapping.
1566 // Where different, insert Phi functions.
1567 // Use any existing Phi functions.
1568 assert(control()->is_Region(), "must be merging to a region");
1569 RegionNode* r = control()->as_Region();
1570
1571 // Compute where to merge into
1572 // Merge incoming control path
1573 r->init_req(pnum, newin->control());
1574
1575 if (pnum == 1) { // Last merge for this Region?
1576 if (!block()->flow()->is_irreducible_entry()) {
1577 Node* result = _gvn.transform_no_reclaim(r);
1578 if (r != result && TraceOptoParse) {
1579 tty->print_cr("Block #%d replace %d with %d", block()->rpo(), r->_idx, result->_idx);
1580 }
1581 }
1582 record_for_igvn(r);
1583 }
1584
1585 // Update all the non-control inputs to map:
1586 assert(TypeFunc::Parms == newin->jvms()->locoff(), "parser map should contain only youngest jvms");
1587 bool check_elide_phi = target->is_SEL_backedge(save_block);
1588 for (uint j = 1; j < newin->req(); j++) {
1589 Node* m = map()->in(j); // Current state of target.
1590 Node* n = newin->in(j); // Incoming change to target state.
1591 PhiNode* phi;
1592 if (m->is_Phi() && m->as_Phi()->region() == r)
1593 phi = m->as_Phi();
1594 else
1595 phi = NULL;
1596 if (m != n) { // Different; must merge
1597 switch (j) {
1598 // Frame pointer and Return Address never changes
1599 case TypeFunc::FramePtr:// Drop m, use the original value
1600 case TypeFunc::ReturnAdr:
1601 break;
1602 case TypeFunc::Memory: // Merge inputs to the MergeMem node
1603 assert(phi == NULL, "the merge contains phis, not vice versa");
1604 merge_memory_edges(n->as_MergeMem(), pnum, nophi);
1605 continue;
1606 default: // All normal stuff
1607 if (phi == NULL) {
1608 const JVMState* jvms = map()->jvms();
1609 if (EliminateNestedLocks &&
1610 jvms->is_mon(j) && jvms->is_monitor_box(j)) {
1611 // BoxLock nodes are not commoning.
1612 // Use old BoxLock node as merged box.
1613 assert(newin->jvms()->is_monitor_box(j), "sanity");
1614 // This assert also tests that nodes are BoxLock.
1615 assert(BoxLockNode::same_slot(n, m), "sanity");
1616 C->gvn_replace_by(n, m);
1617 } else if (!check_elide_phi || !target->can_elide_SEL_phi(j)) {
1618 phi = ensure_phi(j, nophi);
1619 }
1620 }
1621 break;
1622 }
1623 }
1624 // At this point, n might be top if:
1625 // - there is no phi (because TypeFlow detected a conflict), or
1626 // - the corresponding control edges is top (a dead incoming path)
1627 // It is a bug if we create a phi which sees a garbage value on a live path.
1628
1629 if (phi != NULL) {
1630 assert(n != top() || r->in(pnum) == top(), "live value must not be garbage");
1631 assert(phi->region() == r, "");
1632 phi->set_req(pnum, n); // Then add 'n' to the merge
1633 if (pnum == PhiNode::Input) {
1634 // Last merge for this Phi.
1635 // So far, Phis have had a reasonable type from ciTypeFlow.
1636 // Now _gvn will join that with the meet of current inputs.
1637 // BOTTOM is never permissible here, 'cause pessimistically
1638 // Phis of pointers cannot lose the basic pointer type.
1639 debug_only(const Type* bt1 = phi->bottom_type());
1640 assert(bt1 != Type::BOTTOM, "should not be building conflict phis");
1641 map()->set_req(j, _gvn.transform_no_reclaim(phi));
1642 debug_only(const Type* bt2 = phi->bottom_type());
1643 assert(bt2->higher_equal(bt1), "must be consistent with type-flow");
1644 record_for_igvn(phi);
1645 }
1646 }
1647 } // End of for all values to be merged
1648
1649 if (pnum == PhiNode::Input &&
1650 !r->in(0)) { // The occasional useless Region
1651 assert(control() == r, "");
1652 set_control(r->nonnull_req());
1653 }
1654
1655 // newin has been subsumed into the lazy merge, and is now dead.
1656 set_block(save_block);
1657
1658 stop(); // done with this guy, for now
1659 }
1660
1661 if (TraceOptoParse) {
1662 tty->print_cr(" on path %d", pnum);
1663 }
1664
1665 // Done with this parser state.
1666 assert(stopped(), "");
1667 }
1668
1669
1670 //--------------------------merge_memory_edges---------------------------------
1671 void Parse::merge_memory_edges(MergeMemNode* n, int pnum, bool nophi) {
1672 // (nophi means we must not create phis, because we already parsed here)
1673 assert(n != NULL, "");
1674 // Merge the inputs to the MergeMems
1675 MergeMemNode* m = merged_memory();
1676
1677 assert(control()->is_Region(), "must be merging to a region");
1678 RegionNode* r = control()->as_Region();
1679
1680 PhiNode* base = NULL;
1681 MergeMemNode* remerge = NULL;
1682 for (MergeMemStream mms(m, n); mms.next_non_empty2(); ) {
1683 Node *p = mms.force_memory();
1684 Node *q = mms.memory2();
1685 if (mms.is_empty() && nophi) {
1686 // Trouble: No new splits allowed after a loop body is parsed.
1687 // Instead, wire the new split into a MergeMem on the backedge.
1688 // The optimizer will sort it out, slicing the phi.
1689 if (remerge == NULL) {
1690 assert(base != NULL, "");
1691 assert(base->in(0) != NULL, "should not be xformed away");
1692 remerge = MergeMemNode::make(C, base->in(pnum));
1693 gvn().set_type(remerge, Type::MEMORY);
1694 base->set_req(pnum, remerge);
1695 }
1696 remerge->set_memory_at(mms.alias_idx(), q);
1697 continue;
1698 }
1699 assert(!q->is_MergeMem(), "");
1700 PhiNode* phi;
1701 if (p != q) {
1702 phi = ensure_memory_phi(mms.alias_idx(), nophi);
1703 } else {
1704 if (p->is_Phi() && p->as_Phi()->region() == r)
1705 phi = p->as_Phi();
1706 else
1707 phi = NULL;
1708 }
1709 // Insert q into local phi
1710 if (phi != NULL) {
1711 assert(phi->region() == r, "");
1712 p = phi;
1713 phi->set_req(pnum, q);
1714 if (mms.at_base_memory()) {
1715 base = phi; // delay transforming it
1716 } else if (pnum == 1) {
1717 record_for_igvn(phi);
1718 p = _gvn.transform_no_reclaim(phi);
1719 }
1720 mms.set_memory(p);// store back through the iterator
1721 }
1722 }
1723 // Transform base last, in case we must fiddle with remerging.
1724 if (base != NULL && pnum == 1) {
1725 record_for_igvn(base);
1726 m->set_base_memory( _gvn.transform_no_reclaim(base) );
1727 }
1728 }
1729
1730
1731 //------------------------ensure_phis_everywhere-------------------------------
1732 void Parse::ensure_phis_everywhere() {
1733 ensure_phi(TypeFunc::I_O);
1734
1735 // Ensure a phi on all currently known memories.
1736 for (MergeMemStream mms(merged_memory()); mms.next_non_empty(); ) {
1737 ensure_memory_phi(mms.alias_idx());
1738 debug_only(mms.set_memory()); // keep the iterator happy
1739 }
1740
1741 // Note: This is our only chance to create phis for memory slices.
1742 // If we miss a slice that crops up later, it will have to be
1743 // merged into the base-memory phi that we are building here.
1744 // Later, the optimizer will comb out the knot, and build separate
1745 // phi-loops for each memory slice that matters.
1746
1747 // Monitors must nest nicely and not get confused amongst themselves.
1748 // Phi-ify everything up to the monitors, though.
1749 uint monoff = map()->jvms()->monoff();
1750 uint nof_monitors = map()->jvms()->nof_monitors();
1751
1752 assert(TypeFunc::Parms == map()->jvms()->locoff(), "parser map should contain only youngest jvms");
1753 bool check_elide_phi = block()->is_SEL_head();
1754 for (uint i = TypeFunc::Parms; i < monoff; i++) {
1755 if (!check_elide_phi || !block()->can_elide_SEL_phi(i)) {
1756 ensure_phi(i);
1757 }
1758 }
1759
1760 // Even monitors need Phis, though they are well-structured.
1761 // This is true for OSR methods, and also for the rare cases where
1762 // a monitor object is the subject of a replace_in_map operation.
1763 // See bugs 4426707 and 5043395.
1764 for (uint m = 0; m < nof_monitors; m++) {
1765 ensure_phi(map()->jvms()->monitor_obj_offset(m));
1766 }
1767 }
1768
1769
1770 //-----------------------------add_new_path------------------------------------
1771 // Add a previously unaccounted predecessor to this block.
1772 int Parse::Block::add_new_path() {
1773 // If there is no map, return the lowest unused path number.
1774 if (!is_merged()) return pred_count()+1; // there will be a map shortly
1775
1776 SafePointNode* map = start_map();
1777 if (!map->control()->is_Region())
1778 return pred_count()+1; // there may be a region some day
1779 RegionNode* r = map->control()->as_Region();
1780
1781 // Add new path to the region.
1782 uint pnum = r->req();
1783 r->add_req(NULL);
1784
1785 for (uint i = 1; i < map->req(); i++) {
1786 Node* n = map->in(i);
1787 if (i == TypeFunc::Memory) {
1788 // Ensure a phi on all currently known memories.
1789 for (MergeMemStream mms(n->as_MergeMem()); mms.next_non_empty(); ) {
1790 Node* phi = mms.memory();
1791 if (phi->is_Phi() && phi->as_Phi()->region() == r) {
1792 assert(phi->req() == pnum, "must be same size as region");
1793 phi->add_req(NULL);
1794 }
1795 }
1796 } else {
1797 if (n->is_Phi() && n->as_Phi()->region() == r) {
1798 assert(n->req() == pnum, "must be same size as region");
1799 n->add_req(NULL);
1800 }
1801 }
1802 }
1803
1804 return pnum;
1805 }
1806
1807 //------------------------------ensure_phi-------------------------------------
1808 // Turn the idx'th entry of the current map into a Phi
1809 PhiNode *Parse::ensure_phi(int idx, bool nocreate) {
1810 SafePointNode* map = this->map();
1811 Node* region = map->control();
1812 assert(region->is_Region(), "");
1813
1814 Node* o = map->in(idx);
1815 assert(o != NULL, "");
1816
1817 if (o == top()) return NULL; // TOP always merges into TOP
1818
1819 if (o->is_Phi() && o->as_Phi()->region() == region) {
1820 return o->as_Phi();
1821 }
1822
1823 // Now use a Phi here for merging
1824 assert(!nocreate, "Cannot build a phi for a block already parsed.");
1825 const JVMState* jvms = map->jvms();
1826 const Type* t;
1827 if (jvms->is_loc(idx)) {
1828 t = block()->local_type_at(idx - jvms->locoff());
1829 } else if (jvms->is_stk(idx)) {
1830 t = block()->stack_type_at(idx - jvms->stkoff());
1831 } else if (jvms->is_mon(idx)) {
1832 assert(!jvms->is_monitor_box(idx), "no phis for boxes");
1833 t = TypeInstPtr::BOTTOM; // this is sufficient for a lock object
1834 } else if ((uint)idx < TypeFunc::Parms) {
1835 t = o->bottom_type(); // Type::RETURN_ADDRESS or such-like.
1836 } else {
1837 assert(false, "no type information for this phi");
1838 }
1839
1840 // If the type falls to bottom, then this must be a local that
1841 // is mixing ints and oops or some such. Forcing it to top
1842 // makes it go dead.
1843 if (t == Type::BOTTOM) {
1844 map->set_req(idx, top());
1845 return NULL;
1846 }
1847
1848 // Do not create phis for top either.
1849 // A top on a non-null control flow must be an unused even after the.phi.
1850 if (t == Type::TOP || t == Type::HALF) {
1851 map->set_req(idx, top());
1852 return NULL;
1853 }
1854
1855 PhiNode* phi = PhiNode::make(region, o, t);
1856 gvn().set_type(phi, t);
1857 if (C->do_escape_analysis()) record_for_igvn(phi);
1858 map->set_req(idx, phi);
1859 return phi;
1860 }
1861
1862 //--------------------------ensure_memory_phi----------------------------------
1863 // Turn the idx'th slice of the current memory into a Phi
1864 PhiNode *Parse::ensure_memory_phi(int idx, bool nocreate) {
1865 MergeMemNode* mem = merged_memory();
1866 Node* region = control();
1867 assert(region->is_Region(), "");
1868
1869 Node *o = (idx == Compile::AliasIdxBot)? mem->base_memory(): mem->memory_at(idx);
1870 assert(o != NULL && o != top(), "");
1871
1872 PhiNode* phi;
1873 if (o->is_Phi() && o->as_Phi()->region() == region) {
1874 phi = o->as_Phi();
1875 if (phi == mem->base_memory() && idx >= Compile::AliasIdxRaw) {
1876 // clone the shared base memory phi to make a new memory split
1877 assert(!nocreate, "Cannot build a phi for a block already parsed.");
1878 const Type* t = phi->bottom_type();
1879 const TypePtr* adr_type = C->get_adr_type(idx);
1880 phi = phi->slice_memory(adr_type);
1881 gvn().set_type(phi, t);
1882 }
1883 return phi;
1884 }
1885
1886 // Now use a Phi here for merging
1887 assert(!nocreate, "Cannot build a phi for a block already parsed.");
1888 const Type* t = o->bottom_type();
1889 const TypePtr* adr_type = C->get_adr_type(idx);
1890 phi = PhiNode::make(region, o, t, adr_type);
1891 gvn().set_type(phi, t);
1892 if (idx == Compile::AliasIdxBot)
1893 mem->set_base_memory(phi);
1894 else
1895 mem->set_memory_at(idx, phi);
1896 return phi;
1897 }
1898
1899 //------------------------------call_register_finalizer-----------------------
1900 // Check the klass of the receiver and call register_finalizer if the
1901 // class need finalization.
1902 void Parse::call_register_finalizer() {
1903 Node* receiver = local(0);
1904 assert(receiver != NULL && receiver->bottom_type()->isa_instptr() != NULL,
1905 "must have non-null instance type");
1906
1907 const TypeInstPtr *tinst = receiver->bottom_type()->isa_instptr();
1908 if (tinst != NULL && tinst->klass()->is_loaded() && !tinst->klass_is_exact()) {
1909 // The type isn't known exactly so see if CHA tells us anything.
1910 ciInstanceKlass* ik = tinst->klass()->as_instance_klass();
1911 if (!Dependencies::has_finalizable_subclass(ik)) {
1912 // No finalizable subclasses so skip the dynamic check.
1913 C->dependencies()->assert_has_no_finalizable_subclasses(ik);
1914 return;
1915 }
1916 }
1917
1918 // Insert a dynamic test for whether the instance needs
1919 // finalization. In general this will fold up since the concrete
1920 // class is often visible so the access flags are constant.
1921 Node* klass_addr = basic_plus_adr( receiver, receiver, oopDesc::klass_offset_in_bytes() );
1922 Node* klass = _gvn.transform( LoadKlassNode::make(_gvn, immutable_memory(), klass_addr, TypeInstPtr::KLASS) );
1923
1924 Node* access_flags_addr = basic_plus_adr(klass, klass, in_bytes(Klass::access_flags_offset()));
1925 Node* access_flags = make_load(NULL, access_flags_addr, TypeInt::INT, T_INT);
1926
1927 Node* mask = _gvn.transform(new (C) AndINode(access_flags, intcon(JVM_ACC_HAS_FINALIZER)));
1928 Node* check = _gvn.transform(new (C) CmpINode(mask, intcon(0)));
1929 Node* test = _gvn.transform(new (C) BoolNode(check, BoolTest::ne));
1930
1931 IfNode* iff = create_and_map_if(control(), test, PROB_MAX, COUNT_UNKNOWN);
1932
1933 RegionNode* result_rgn = new (C) RegionNode(3);
1934 record_for_igvn(result_rgn);
1935
1936 Node *skip_register = _gvn.transform(new (C) IfFalseNode(iff));
1937 result_rgn->init_req(1, skip_register);
1938
1939 Node *needs_register = _gvn.transform(new (C) IfTrueNode(iff));
1940 set_control(needs_register);
1941 if (stopped()) {
1942 // There is no slow path.
1943 result_rgn->init_req(2, top());
1944 } else {
1945 Node *call = make_runtime_call(RC_NO_LEAF,
1946 OptoRuntime::register_finalizer_Type(),
1947 OptoRuntime::register_finalizer_Java(),
1948 NULL, TypePtr::BOTTOM,
1949 receiver);
1950 make_slow_call_ex(call, env()->Throwable_klass(), true);
1951
1952 Node* fast_io = call->in(TypeFunc::I_O);
1953 Node* fast_mem = call->in(TypeFunc::Memory);
1954 // These two phis are pre-filled with copies of of the fast IO and Memory
1955 Node* io_phi = PhiNode::make(result_rgn, fast_io, Type::ABIO);
1956 Node* mem_phi = PhiNode::make(result_rgn, fast_mem, Type::MEMORY, TypePtr::BOTTOM);
1957
1958 result_rgn->init_req(2, control());
1959 io_phi ->init_req(2, i_o());
1960 mem_phi ->init_req(2, reset_memory());
1961
1962 set_all_memory( _gvn.transform(mem_phi) );
1963 set_i_o( _gvn.transform(io_phi) );
1964 }
1965
1966 set_control( _gvn.transform(result_rgn) );
1967 }
1968
1969 //------------------------------return_current---------------------------------
1970 // Append current _map to _exit_return
1971 void Parse::return_current(Node* value) {
1972 if (RegisterFinalizersAtInit &&
1973 method()->intrinsic_id() == vmIntrinsics::_Object_init) {
1974 call_register_finalizer();
1975 }
1976
1977 // Do not set_parse_bci, so that return goo is credited to the return insn.
1978 set_bci(InvocationEntryBci);
1979 if (method()->is_synchronized() && GenerateSynchronizationCode) {
1980 shared_unlock(_synch_lock->box_node(), _synch_lock->obj_node());
1981 }
1982 if (C->env()->dtrace_method_probes()) {
1983 make_dtrace_method_exit(method());
1984 }
1985 SafePointNode* exit_return = _exits.map();
1986 exit_return->in( TypeFunc::Control )->add_req( control() );
1987 exit_return->in( TypeFunc::I_O )->add_req( i_o () );
1988 Node *mem = exit_return->in( TypeFunc::Memory );
1989 for (MergeMemStream mms(mem->as_MergeMem(), merged_memory()); mms.next_non_empty2(); ) {
1990 if (mms.is_empty()) {
1991 // get a copy of the base memory, and patch just this one input
1992 const TypePtr* adr_type = mms.adr_type(C);
1993 Node* phi = mms.force_memory()->as_Phi()->slice_memory(adr_type);
1994 assert(phi->as_Phi()->region() == mms.base_memory()->in(0), "");
1995 gvn().set_type_bottom(phi);
1996 phi->del_req(phi->req()-1); // prepare to re-patch
1997 mms.set_memory(phi);
1998 }
1999 mms.memory()->add_req(mms.memory2());
2000 }
2001
2002 // frame pointer is always same, already captured
2003 if (value != NULL) {
2004 // If returning oops to an interface-return, there is a silent free
2005 // cast from oop to interface allowed by the Verifier. Make it explicit
2006 // here.
2007 Node* phi = _exits.argument(0);
2008 const TypeInstPtr *tr = phi->bottom_type()->isa_instptr();
2009 if( tr && tr->klass()->is_loaded() &&
2010 tr->klass()->is_interface() ) {
2011 const TypeInstPtr *tp = value->bottom_type()->isa_instptr();
2012 if (tp && tp->klass()->is_loaded() &&
2013 !tp->klass()->is_interface()) {
2014 // sharpen the type eagerly; this eases certain assert checking
2015 if (tp->higher_equal(TypeInstPtr::NOTNULL))
2016 tr = tr->join(TypeInstPtr::NOTNULL)->is_instptr();
2017 value = _gvn.transform(new (C) CheckCastPPNode(0,value,tr));
2018 }
2019 }
2020 phi->add_req(value);
2021 }
2022
2023 stop_and_kill_map(); // This CFG path dies here
2024 }
2025
2026
2027 //------------------------------add_safepoint----------------------------------
2028 void Parse::add_safepoint() {
2029 // See if we can avoid this safepoint. No need for a SafePoint immediately
2030 // after a Call (except Leaf Call) or another SafePoint.
2031 Node *proj = control();
2032 bool add_poll_param = SafePointNode::needs_polling_address_input();
2033 uint parms = add_poll_param ? TypeFunc::Parms+1 : TypeFunc::Parms;
2034 if( proj->is_Proj() ) {
2035 Node *n0 = proj->in(0);
2036 if( n0->is_Catch() ) {
2037 n0 = n0->in(0)->in(0);
2038 assert( n0->is_Call(), "expect a call here" );
2039 }
2040 if( n0->is_Call() ) {
2041 if( n0->as_Call()->guaranteed_safepoint() )
2042 return;
2043 } else if( n0->is_SafePoint() && n0->req() >= parms ) {
2044 return;
2045 }
2046 }
2047
2048 // Clear out dead values from the debug info.
2049 kill_dead_locals();
2050
2051 // Clone the JVM State
2052 SafePointNode *sfpnt = new (C) SafePointNode(parms, NULL);
2053
2054 // Capture memory state BEFORE a SafePoint. Since we can block at a
2055 // SafePoint we need our GC state to be safe; i.e. we need all our current
2056 // write barriers (card marks) to not float down after the SafePoint so we
2057 // must read raw memory. Likewise we need all oop stores to match the card
2058 // marks. If deopt can happen, we need ALL stores (we need the correct JVM
2059 // state on a deopt).
2060
2061 // We do not need to WRITE the memory state after a SafePoint. The control
2062 // edge will keep card-marks and oop-stores from floating up from below a
2063 // SafePoint and our true dependency added here will keep them from floating
2064 // down below a SafePoint.
2065
2066 // Clone the current memory state
2067 Node* mem = MergeMemNode::make(C, map()->memory());
2068
2069 mem = _gvn.transform(mem);
2070
2071 // Pass control through the safepoint
2072 sfpnt->init_req(TypeFunc::Control , control());
2073 // Fix edges normally used by a call
2074 sfpnt->init_req(TypeFunc::I_O , top() );
2075 sfpnt->init_req(TypeFunc::Memory , mem );
2076 sfpnt->init_req(TypeFunc::ReturnAdr, top() );
2077 sfpnt->init_req(TypeFunc::FramePtr , top() );
2078
2079 // Create a node for the polling address
2080 if( add_poll_param ) {
2081 Node *polladr = ConPNode::make(C, (address)os::get_polling_page());
2082 sfpnt->init_req(TypeFunc::Parms+0, _gvn.transform(polladr));
2083 }
2084
2085 // Fix up the JVM State edges
2086 add_safepoint_edges(sfpnt);
2087 Node *transformed_sfpnt = _gvn.transform(sfpnt);
2088 set_control(transformed_sfpnt);
2089
2090 // Provide an edge from root to safepoint. This makes the safepoint
2091 // appear useful until the parse has completed.
2092 if( OptoRemoveUseless && transformed_sfpnt->is_SafePoint() ) {
2093 assert(C->root() != NULL, "Expect parse is still valid");
2094 C->root()->add_prec(transformed_sfpnt);
2095 }
2096 }
2097
2098 #ifndef PRODUCT
2099 //------------------------show_parse_info--------------------------------------
2100 void Parse::show_parse_info() {
2101 InlineTree* ilt = NULL;
2102 if (C->ilt() != NULL) {
2103 JVMState* caller_jvms = is_osr_parse() ? caller()->caller() : caller();
2104 ilt = InlineTree::find_subtree_from_root(C->ilt(), caller_jvms, method());
2105 }
2106 if (PrintCompilation && Verbose) {
2107 if (depth() == 1) {
2108 if( ilt->count_inlines() ) {
2109 tty->print(" __inlined %d (%d bytes)", ilt->count_inlines(),
2110 ilt->count_inline_bcs());
2111 tty->cr();
2112 }
2113 } else {
2114 if (method()->is_synchronized()) tty->print("s");
2115 if (method()->has_exception_handlers()) tty->print("!");
2116 // Check this is not the final compiled version
2117 if (C->trap_can_recompile()) {
2118 tty->print("-");
2119 } else {
2120 tty->print(" ");
2121 }
2122 method()->print_short_name();
2123 if (is_osr_parse()) {
2124 tty->print(" @ %d", osr_bci());
2125 }
2126 tty->print(" (%d bytes)",method()->code_size());
2127 if (ilt->count_inlines()) {
2128 tty->print(" __inlined %d (%d bytes)", ilt->count_inlines(),
2129 ilt->count_inline_bcs());
2130 }
2131 tty->cr();
2132 }
2133 }
2134 if (PrintOpto && (depth() == 1 || PrintOptoInlining)) {
2135 // Print that we succeeded; suppress this message on the first osr parse.
2136
2137 if (method()->is_synchronized()) tty->print("s");
2138 if (method()->has_exception_handlers()) tty->print("!");
2139 // Check this is not the final compiled version
2140 if (C->trap_can_recompile() && depth() == 1) {
2141 tty->print("-");
2142 } else {
2143 tty->print(" ");
2144 }
2145 if( depth() != 1 ) { tty->print(" "); } // missing compile count
2146 for (int i = 1; i < depth(); ++i) { tty->print(" "); }
2147 method()->print_short_name();
2148 if (is_osr_parse()) {
2149 tty->print(" @ %d", osr_bci());
2150 }
2151 if (ilt->caller_bci() != -1) {
2152 tty->print(" @ %d", ilt->caller_bci());
2153 }
2154 tty->print(" (%d bytes)",method()->code_size());
2155 if (ilt->count_inlines()) {
2156 tty->print(" __inlined %d (%d bytes)", ilt->count_inlines(),
2157 ilt->count_inline_bcs());
2158 }
2159 tty->cr();
2160 }
2161 }
2162
2163
2164 //------------------------------dump-------------------------------------------
2165 // Dump information associated with the bytecodes of current _method
2166 void Parse::dump() {
2167 if( method() != NULL ) {
2168 // Iterate over bytecodes
2169 ciBytecodeStream iter(method());
2170 for( Bytecodes::Code bc = iter.next(); bc != ciBytecodeStream::EOBC() ; bc = iter.next() ) {
2171 dump_bci( iter.cur_bci() );
2172 tty->cr();
2173 }
2174 }
2175 }
2176
2177 // Dump information associated with a byte code index, 'bci'
2178 void Parse::dump_bci(int bci) {
2179 // Output info on merge-points, cloning, and within _jsr..._ret
2180 // NYI
2181 tty->print(" bci:%d", bci);
2182 }
2183
2184 #endif