1 /*
   2  * Copyright (c) 1997, 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 "compiler/compileLog.hpp"
  26 #include "interpreter/linkResolver.hpp"
  27 #include "memory/resourceArea.hpp"
  28 #include "oops/method.hpp"
  29 #include "opto/addnode.hpp"
  30 #include "opto/c2compiler.hpp"
  31 #include "opto/castnode.hpp"
  32 #include "opto/idealGraphPrinter.hpp"
  33 #include "opto/locknode.hpp"
  34 #include "opto/memnode.hpp"
  35 #include "opto/opaquenode.hpp"
  36 #include "opto/parse.hpp"
  37 #include "opto/rootnode.hpp"
  38 #include "opto/runtime.hpp"
  39 #include "opto/type.hpp"
  40 #include "runtime/handles.inline.hpp"
  41 #include "runtime/safepointMechanism.hpp"
  42 #include "runtime/sharedRuntime.hpp"
  43 #include "utilities/bitMap.inline.hpp"
  44 #include "utilities/copy.hpp"
  45 
  46 // Static array so we can figure out which bytecodes stop us from compiling
  47 // the most. Some of the non-static variables are needed in bytecodeInfo.cpp
  48 // and eventually should be encapsulated in a proper class (gri 8/18/98).
  49 
  50 #ifndef PRODUCT
  51 uint nodes_created             = 0;
  52 uint methods_parsed            = 0;
  53 uint methods_seen              = 0;
  54 uint blocks_parsed             = 0;
  55 uint blocks_seen               = 0;
  56 
  57 uint explicit_null_checks_inserted = 0;
  58 uint explicit_null_checks_elided   = 0;
  59 uint all_null_checks_found         = 0;
  60 uint implicit_null_checks          = 0;
  61 
  62 bool Parse::BytecodeParseHistogram::_initialized = false;
  63 uint Parse::BytecodeParseHistogram::_bytecodes_parsed [Bytecodes::number_of_codes];
  64 uint Parse::BytecodeParseHistogram::_nodes_constructed[Bytecodes::number_of_codes];
  65 uint Parse::BytecodeParseHistogram::_nodes_transformed[Bytecodes::number_of_codes];
  66 uint Parse::BytecodeParseHistogram::_new_values       [Bytecodes::number_of_codes];
  67 
  68 //------------------------------print_statistics-------------------------------
  69 void Parse::print_statistics() {
  70   tty->print_cr("--- Compiler Statistics ---");
  71   tty->print("Methods seen: %u  Methods parsed: %u", methods_seen, methods_parsed);
  72   tty->print("  Nodes created: %u", nodes_created);
  73   tty->cr();
  74   if (methods_seen != methods_parsed) {
  75     tty->print_cr("Reasons for parse failures (NOT cumulative):");
  76   }
  77   tty->print_cr("Blocks parsed: %u  Blocks seen: %u", blocks_parsed, blocks_seen);
  78 
  79   if (explicit_null_checks_inserted) {
  80     tty->print_cr("%u original null checks - %u elided (%2u%%); optimizer leaves %u,",
  81                   explicit_null_checks_inserted, explicit_null_checks_elided,
  82                   (100*explicit_null_checks_elided)/explicit_null_checks_inserted,
  83                   all_null_checks_found);
  84   }
  85   if (all_null_checks_found) {
  86     tty->print_cr("%u made implicit (%2u%%)", implicit_null_checks,
  87                   (100*implicit_null_checks)/all_null_checks_found);
  88   }
  89   if (SharedRuntime::_implicit_null_throws) {
  90     tty->print_cr("%u implicit null exceptions at runtime",
  91                   SharedRuntime::_implicit_null_throws);
  92   }
  93 
  94   if (PrintParseStatistics && BytecodeParseHistogram::initialized()) {
  95     BytecodeParseHistogram::print();
  96   }
  97 }
  98 #endif
  99 
 100 //------------------------------ON STACK REPLACEMENT---------------------------
 101 
 102 // Construct a node which can be used to get incoming state for
 103 // on stack replacement.
 104 Node *Parse::fetch_interpreter_state(int index,
 105                                      BasicType bt,
 106                                      Node* local_addrs) {
 107   Node *mem = memory(Compile::AliasIdxRaw);
 108   Node *adr = basic_plus_adr(top(), local_addrs, -index*wordSize);
 109   Node *ctl = control();
 110 
 111   // Very similar to LoadNode::make, except we handle un-aligned longs and
 112   // doubles on Sparc.  Intel can handle them just fine directly.
 113   Node *l = nullptr;
 114   switch (bt) {                // Signature is flattened
 115   case T_INT:     l = new LoadINode(ctl, mem, adr, TypeRawPtr::BOTTOM, TypeInt::INT,        MemNode::unordered); break;
 116   case T_FLOAT:   l = new LoadFNode(ctl, mem, adr, TypeRawPtr::BOTTOM, Type::FLOAT,         MemNode::unordered); break;
 117   case T_ADDRESS: l = new LoadPNode(ctl, mem, adr, TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM,  MemNode::unordered); break;
 118   case T_OBJECT:  l = new LoadPNode(ctl, mem, adr, TypeRawPtr::BOTTOM, TypeInstPtr::BOTTOM, MemNode::unordered); break;
 119   case T_LONG:
 120   case T_DOUBLE: {
 121     // Since arguments are in reverse order, the argument address 'adr'
 122     // refers to the back half of the long/double.  Recompute adr.
 123     adr = basic_plus_adr(top(), local_addrs, -(index+1)*wordSize);
 124     if (Matcher::misaligned_doubles_ok) {
 125       l = (bt == T_DOUBLE)
 126         ? (Node*)new LoadDNode(ctl, mem, adr, TypeRawPtr::BOTTOM, Type::DOUBLE, MemNode::unordered)
 127         : (Node*)new LoadLNode(ctl, mem, adr, TypeRawPtr::BOTTOM, TypeLong::LONG, MemNode::unordered);
 128     } else {
 129       l = (bt == T_DOUBLE)
 130         ? (Node*)new LoadD_unalignedNode(ctl, mem, adr, TypeRawPtr::BOTTOM, MemNode::unordered)
 131         : (Node*)new LoadL_unalignedNode(ctl, mem, adr, TypeRawPtr::BOTTOM, MemNode::unordered);
 132     }
 133     break;
 134   }
 135   default: ShouldNotReachHere();
 136   }
 137   return _gvn.transform(l);
 138 }
 139 
 140 // Helper routine to prevent the interpreter from handing
 141 // unexpected typestate to an OSR method.
 142 // The Node l is a value newly dug out of the interpreter frame.
 143 // The type is the type predicted by ciTypeFlow.  Note that it is
 144 // not a general type, but can only come from Type::get_typeflow_type.
 145 // The safepoint is a map which will feed an uncommon trap.
 146 Node* Parse::check_interpreter_type(Node* l, const Type* type,
 147                                     SafePointNode* &bad_type_exit) {
 148 
 149   const TypeOopPtr* tp = type->isa_oopptr();
 150 
 151   // TypeFlow may assert null-ness if a type appears unloaded.
 152   if (type == TypePtr::NULL_PTR ||
 153       (tp != nullptr && !tp->is_loaded())) {
 154     // Value must be null, not a real oop.
 155     Node* chk = _gvn.transform( new CmpPNode(l, null()) );
 156     Node* tst = _gvn.transform( new BoolNode(chk, BoolTest::eq) );
 157     IfNode* iff = create_and_map_if(control(), tst, PROB_MAX, COUNT_UNKNOWN);
 158     set_control(_gvn.transform( new IfTrueNode(iff) ));
 159     Node* bad_type = _gvn.transform( new IfFalseNode(iff) );
 160     bad_type_exit->control()->add_req(bad_type);
 161     l = null();
 162   }
 163 
 164   // Typeflow can also cut off paths from the CFG, based on
 165   // types which appear unloaded, or call sites which appear unlinked.
 166   // When paths are cut off, values at later merge points can rise
 167   // toward more specific classes.  Make sure these specific classes
 168   // are still in effect.
 169   if (tp != nullptr && !tp->is_same_java_type_as(TypeInstPtr::BOTTOM)) {
 170     // TypeFlow asserted a specific object type.  Value must have that type.
 171     Node* bad_type_ctrl = nullptr;
 172     l = gen_checkcast(l, makecon(tp->as_klass_type()->cast_to_exactness(true)), &bad_type_ctrl);
 173     bad_type_exit->control()->add_req(bad_type_ctrl);
 174   }
 175 
 176   assert(_gvn.type(l)->higher_equal(type), "must constrain OSR typestate");
 177   return l;
 178 }
 179 
 180 // Helper routine which sets up elements of the initial parser map when
 181 // performing a parse for on stack replacement.  Add values into map.
 182 // The only parameter contains the address of a interpreter arguments.
 183 void Parse::load_interpreter_state(Node* osr_buf) {
 184   int index;
 185   int max_locals = jvms()->loc_size();
 186   int max_stack  = jvms()->stk_size();
 187 
 188 
 189   // Mismatch between method and jvms can occur since map briefly held
 190   // an OSR entry state (which takes up one RawPtr word).
 191   assert(max_locals == method()->max_locals(), "sanity");
 192   assert(max_stack  >= method()->max_stack(),  "sanity");
 193   assert((int)jvms()->endoff() == TypeFunc::Parms + max_locals + max_stack, "sanity");
 194   assert((int)jvms()->endoff() == (int)map()->req(), "sanity");
 195 
 196   // Find the start block.
 197   Block* osr_block = start_block();
 198   assert(osr_block->start() == osr_bci(), "sanity");
 199 
 200   // Set initial BCI.
 201   set_parse_bci(osr_block->start());
 202 
 203   // Set initial stack depth.
 204   set_sp(osr_block->start_sp());
 205 
 206   // Check bailouts.  We currently do not perform on stack replacement
 207   // of loops in catch blocks or loops which branch with a non-empty stack.
 208   if (sp() != 0) {
 209     C->record_method_not_compilable("OSR starts with non-empty stack");
 210     return;
 211   }
 212   // Do not OSR inside finally clauses:
 213   if (osr_block->has_trap_at(osr_block->start())) {
 214     assert(false, "OSR starts with an immediate trap");
 215     C->record_method_not_compilable("OSR starts with an immediate trap");
 216     return;
 217   }
 218 
 219   // Commute monitors from interpreter frame to compiler frame.
 220   assert(jvms()->monitor_depth() == 0, "should be no active locks at beginning of osr");
 221   int mcnt = osr_block->flow()->monitor_count();
 222   Node *monitors_addr = basic_plus_adr(top(), osr_buf, (max_locals+mcnt*2-1)*wordSize);
 223   for (index = 0; index < mcnt; index++) {
 224     // Make a BoxLockNode for the monitor.
 225     BoxLockNode* osr_box = new BoxLockNode(next_monitor());
 226     // Check for bailout after new BoxLockNode
 227     if (failing()) { return; }
 228 
 229     // This OSR locking region is unbalanced because it does not have Lock node:
 230     // locking was done in Interpreter.
 231     // This is similar to Coarsened case when Lock node is eliminated
 232     // and as result the region is marked as Unbalanced.
 233 
 234     // Emulate Coarsened state transition from Regular to Unbalanced.
 235     osr_box->set_coarsened();
 236     osr_box->set_unbalanced();
 237 
 238     Node* box = _gvn.transform(osr_box);
 239 
 240     // Displaced headers and locked objects are interleaved in the
 241     // temp OSR buffer.  We only copy the locked objects out here.
 242     // Fetch the locked object from the OSR temp buffer and copy to our fastlock node.
 243     Node *lock_object = fetch_interpreter_state(index*2, T_OBJECT, monitors_addr);
 244     // Try and copy the displaced header to the BoxNode
 245     Node *displaced_hdr = fetch_interpreter_state((index*2) + 1, T_ADDRESS, monitors_addr);
 246 
 247 
 248     store_to_memory(control(), box, displaced_hdr, T_ADDRESS, MemNode::unordered);
 249 
 250     // Build a bogus FastLockNode (no code will be generated) and push the
 251     // monitor into our debug info.
 252     const FastLockNode *flock = _gvn.transform(new FastLockNode( nullptr, lock_object, box ))->as_FastLock();
 253     map()->push_monitor(flock);
 254 
 255     // If the lock is our method synchronization lock, tuck it away in
 256     // _sync_lock for return and rethrow exit paths.
 257     if (index == 0 && method()->is_synchronized()) {
 258       _synch_lock = flock;
 259     }
 260   }
 261 
 262   // Use the raw liveness computation to make sure that unexpected
 263   // values don't propagate into the OSR frame.
 264   MethodLivenessResult live_locals = method()->liveness_at_bci(osr_bci());
 265   if (!live_locals.is_valid()) {
 266     // Degenerate or breakpointed method.
 267     assert(false, "OSR in empty or breakpointed method");
 268     C->record_method_not_compilable("OSR in empty or breakpointed method");
 269     return;
 270   }
 271 
 272   // Extract the needed locals from the interpreter frame.
 273   Node *locals_addr = basic_plus_adr(top(), osr_buf, (max_locals-1)*wordSize);
 274 
 275   // find all the locals that the interpreter thinks contain live oops
 276   const ResourceBitMap live_oops = method()->live_local_oops_at_bci(osr_bci());
 277   for (index = 0; index < max_locals; index++) {
 278 
 279     if (!live_locals.at(index)) {
 280       continue;
 281     }
 282 
 283     const Type *type = osr_block->local_type_at(index);
 284 
 285     if (type->isa_oopptr() != nullptr) {
 286 
 287       // 6403625: Verify that the interpreter oopMap thinks that the oop is live
 288       // else we might load a stale oop if the MethodLiveness disagrees with the
 289       // result of the interpreter. If the interpreter says it is dead we agree
 290       // by making the value go to top.
 291       //
 292 
 293       if (!live_oops.at(index)) {
 294         if (C->log() != nullptr) {
 295           C->log()->elem("OSR_mismatch local_index='%d'",index);
 296         }
 297         set_local(index, null());
 298         // and ignore it for the loads
 299         continue;
 300       }
 301     }
 302 
 303     // Filter out TOP, HALF, and BOTTOM.  (Cf. ensure_phi.)
 304     if (type == Type::TOP || type == Type::HALF) {
 305       continue;
 306     }
 307     // If the type falls to bottom, then this must be a local that
 308     // is mixing ints and oops or some such.  Forcing it to top
 309     // makes it go dead.
 310     if (type == Type::BOTTOM) {
 311       continue;
 312     }
 313     // Construct code to access the appropriate local.
 314     BasicType bt = type->basic_type();
 315     if (type == TypePtr::NULL_PTR) {
 316       // Ptr types are mixed together with T_ADDRESS but null is
 317       // really for T_OBJECT types so correct it.
 318       bt = T_OBJECT;
 319     }
 320     Node *value = fetch_interpreter_state(index, bt, locals_addr);
 321     set_local(index, value);
 322   }
 323 
 324   // Extract the needed stack entries from the interpreter frame.
 325   for (index = 0; index < sp(); index++) {
 326     const Type *type = osr_block->stack_type_at(index);
 327     if (type != Type::TOP) {
 328       // Currently the compiler bails out when attempting to on stack replace
 329       // at a bci with a non-empty stack.  We should not reach here.
 330       ShouldNotReachHere();
 331     }
 332   }
 333 
 334   // End the OSR migration
 335   make_runtime_call(RC_LEAF, OptoRuntime::osr_end_Type(),
 336                     CAST_FROM_FN_PTR(address, SharedRuntime::OSR_migration_end),
 337                     "OSR_migration_end", TypeRawPtr::BOTTOM,
 338                     osr_buf);
 339 
 340   // Now that the interpreter state is loaded, make sure it will match
 341   // at execution time what the compiler is expecting now:
 342   SafePointNode* bad_type_exit = clone_map();
 343   bad_type_exit->set_control(new RegionNode(1));
 344 
 345   assert(osr_block->flow()->jsrs()->size() == 0, "should be no jsrs live at osr point");
 346   for (index = 0; index < max_locals; index++) {
 347     if (stopped())  break;
 348     Node* l = local(index);
 349     if (l->is_top())  continue;  // nothing here
 350     const Type *type = osr_block->local_type_at(index);
 351     if (type->isa_oopptr() != nullptr) {
 352       if (!live_oops.at(index)) {
 353         // skip type check for dead oops
 354         continue;
 355       }
 356     }
 357     if (osr_block->flow()->local_type_at(index)->is_return_address()) {
 358       // In our current system it's illegal for jsr addresses to be
 359       // live into an OSR entry point because the compiler performs
 360       // inlining of jsrs.  ciTypeFlow has a bailout that detect this
 361       // case and aborts the compile if addresses are live into an OSR
 362       // entry point.  Because of that we can assume that any address
 363       // locals at the OSR entry point are dead.  Method liveness
 364       // isn't precise enough to figure out that they are dead in all
 365       // cases so simply skip checking address locals all
 366       // together. Any type check is guaranteed to fail since the
 367       // interpreter type is the result of a load which might have any
 368       // value and the expected type is a constant.
 369       continue;
 370     }
 371     set_local(index, check_interpreter_type(l, type, bad_type_exit));
 372   }
 373 
 374   for (index = 0; index < sp(); index++) {
 375     if (stopped())  break;
 376     Node* l = stack(index);
 377     if (l->is_top())  continue;  // nothing here
 378     const Type *type = osr_block->stack_type_at(index);
 379     set_stack(index, check_interpreter_type(l, type, bad_type_exit));
 380   }
 381 
 382   if (bad_type_exit->control()->req() > 1) {
 383     // Build an uncommon trap here, if any inputs can be unexpected.
 384     bad_type_exit->set_control(_gvn.transform( bad_type_exit->control() ));
 385     record_for_igvn(bad_type_exit->control());
 386     SafePointNode* types_are_good = map();
 387     set_map(bad_type_exit);
 388     // The unexpected type happens because a new edge is active
 389     // in the CFG, which typeflow had previously ignored.
 390     // E.g., Object x = coldAtFirst() && notReached()? "str": new Integer(123).
 391     // This x will be typed as Integer if notReached is not yet linked.
 392     // It could also happen due to a problem in ciTypeFlow analysis.
 393     uncommon_trap(Deoptimization::Reason_constraint,
 394                   Deoptimization::Action_reinterpret);
 395     set_map(types_are_good);
 396   }
 397 }
 398 
 399 //------------------------------Parse------------------------------------------
 400 // Main parser constructor.
 401 Parse::Parse(JVMState* caller, ciMethod* parse_method, float expected_uses)
 402   : _exits(caller)
 403 {
 404   // Init some variables
 405   _caller = caller;
 406   _method = parse_method;
 407   _expected_uses = expected_uses;
 408   _depth = 1 + (caller->has_method() ? caller->depth() : 0);
 409   _wrote_final = false;
 410   _wrote_volatile = false;
 411   _wrote_stable = false;
 412   _wrote_fields = false;
 413   _alloc_with_final_or_stable = nullptr;
 414   _block = nullptr;
 415   _first_return = true;
 416   _replaced_nodes_for_exceptions = false;
 417   _new_idx = C->unique();
 418   DEBUG_ONLY(_entry_bci = UnknownBci);
 419   DEBUG_ONLY(_block_count = -1);
 420   DEBUG_ONLY(_blocks = (Block*)-1);
 421 #ifndef PRODUCT
 422   if (PrintCompilation || PrintOpto) {
 423     // Make sure I have an inline tree, so I can print messages about it.
 424     InlineTree::find_subtree_from_root(C->ilt(), caller, parse_method);
 425   }
 426   _max_switch_depth = 0;
 427   _est_switch_depth = 0;
 428 #endif
 429 
 430   if (parse_method->has_reserved_stack_access()) {
 431     C->set_has_reserved_stack_access(true);
 432   }
 433 
 434   if (parse_method->is_synchronized() || parse_method->has_monitor_bytecodes()) {
 435     C->set_has_monitors(true);
 436   }
 437 
 438   if (parse_method->is_scoped()) {
 439     C->set_has_scoped_access(true);
 440   }
 441 
 442   _iter.reset_to_method(method());
 443   C->set_has_loops(C->has_loops() || method()->has_loops());
 444 
 445   if (_expected_uses <= 0) {
 446     _prof_factor = 1;
 447   } else {
 448     float prof_total = parse_method->interpreter_invocation_count();
 449     if (prof_total <= _expected_uses) {
 450       _prof_factor = 1;
 451     } else {
 452       _prof_factor = _expected_uses / prof_total;
 453     }
 454   }
 455 
 456   CompileLog* log = C->log();
 457   if (log != nullptr) {
 458     log->begin_head("parse method='%d' uses='%f'",
 459                     log->identify(parse_method), expected_uses);
 460     if (depth() == 1 && C->is_osr_compilation()) {
 461       log->print(" osr_bci='%d'", C->entry_bci());
 462     }
 463     log->stamp();
 464     log->end_head();
 465   }
 466 
 467   // Accumulate deoptimization counts.
 468   // (The range_check and store_check counts are checked elsewhere.)
 469   ciMethodData* md = method()->method_data();
 470   for (uint reason = 0; reason < md->trap_reason_limit(); reason++) {
 471     uint md_count = md->trap_count(reason);
 472     if (md_count != 0) {
 473       if (md_count >= md->trap_count_limit()) {
 474         md_count = md->trap_count_limit() + md->overflow_trap_count();
 475       }
 476       uint total_count = C->trap_count(reason);
 477       uint old_count   = total_count;
 478       total_count += md_count;
 479       // Saturate the add if it overflows.
 480       if (total_count < old_count || total_count < md_count)
 481         total_count = (uint)-1;
 482       C->set_trap_count(reason, total_count);
 483       if (log != nullptr)
 484         log->elem("observe trap='%s' count='%d' total='%d'",
 485                   Deoptimization::trap_reason_name(reason),
 486                   md_count, total_count);
 487     }
 488   }
 489   // Accumulate total sum of decompilations, also.
 490   C->set_decompile_count(C->decompile_count() + md->decompile_count());
 491 
 492   if (log != nullptr && method()->has_exception_handlers()) {
 493     log->elem("observe that='has_exception_handlers'");
 494   }
 495 
 496   assert(InlineTree::check_can_parse(method()) == nullptr, "Can not parse this method, cutout earlier");
 497   assert(method()->has_balanced_monitors(), "Can not parse unbalanced monitors, cutout earlier");
 498 
 499   // Always register dependence if JVMTI is enabled, because
 500   // either breakpoint setting or hotswapping of methods may
 501   // cause deoptimization.
 502   if (C->env()->jvmti_can_hotswap_or_post_breakpoint()) {
 503     C->dependencies()->assert_evol_method(method());
 504   }
 505 
 506   NOT_PRODUCT(methods_seen++);
 507 
 508   // Do some special top-level things.
 509   if (depth() == 1 && C->is_osr_compilation()) {
 510     _tf = C->tf();     // the OSR entry type is different
 511     _entry_bci = C->entry_bci();
 512     _flow = method()->get_osr_flow_analysis(osr_bci());
 513   } else {
 514     _tf = TypeFunc::make(method());
 515     _entry_bci = InvocationEntryBci;
 516     _flow = method()->get_flow_analysis();
 517   }
 518 
 519   if (_flow->failing()) {
 520     assert(false, "type flow analysis failed during parsing");
 521     C->record_method_not_compilable(_flow->failure_reason());
 522 #ifndef PRODUCT
 523       if (PrintOpto && (Verbose || WizardMode)) {
 524         if (is_osr_parse()) {
 525           tty->print_cr("OSR @%d type flow bailout: %s", _entry_bci, _flow->failure_reason());
 526         } else {
 527           tty->print_cr("type flow bailout: %s", _flow->failure_reason());
 528         }
 529         if (Verbose) {
 530           method()->print();
 531           method()->print_codes();
 532           _flow->print();
 533         }
 534       }
 535 #endif
 536   }
 537 
 538 #ifdef ASSERT
 539   if (depth() == 1) {
 540     assert(C->is_osr_compilation() == this->is_osr_parse(), "OSR in sync");
 541   } else {
 542     assert(!this->is_osr_parse(), "no recursive OSR");
 543   }
 544 #endif
 545 
 546 #ifndef PRODUCT
 547   if (_flow->has_irreducible_entry()) {
 548     C->set_parsed_irreducible_loop(true);
 549   }
 550 
 551   methods_parsed++;
 552   // add method size here to guarantee that inlined methods are added too
 553   if (CITime)
 554     _total_bytes_compiled += method()->code_size();
 555 
 556   show_parse_info();
 557 #endif
 558 
 559   if (failing()) {
 560     if (log)  log->done("parse");
 561     return;
 562   }
 563 
 564   gvn().transform(top());
 565 
 566   // Import the results of the ciTypeFlow.
 567   init_blocks();
 568 
 569   // Merge point for all normal exits
 570   build_exits();
 571 
 572   // Setup the initial JVM state map.
 573   SafePointNode* entry_map = create_entry_map();
 574 
 575   // Check for bailouts during map initialization
 576   if (failing() || entry_map == nullptr) {
 577     if (log)  log->done("parse");
 578     return;
 579   }
 580 
 581   Node_Notes* caller_nn = C->default_node_notes();
 582   // Collect debug info for inlined calls unless -XX:-DebugInlinedCalls.
 583   if (DebugInlinedCalls || depth() == 1) {
 584     C->set_default_node_notes(make_node_notes(caller_nn));
 585   }
 586 
 587   if (is_osr_parse()) {
 588     Node* osr_buf = entry_map->in(TypeFunc::Parms+0);
 589     entry_map->set_req(TypeFunc::Parms+0, top());
 590     set_map(entry_map);
 591     load_interpreter_state(osr_buf);
 592   } else {
 593     set_map(entry_map);
 594     do_method_entry();
 595   }
 596 
 597   if (depth() == 1 && !failing()) {
 598     if (C->clinit_barrier_on_entry()) {
 599       // Add check to deoptimize the nmethod once the holder class is fully initialized
 600       clinit_deopt();
 601     }
 602   }
 603 
 604   // Check for bailouts during method entry.
 605   if (failing()) {
 606     if (log)  log->done("parse");
 607     C->set_default_node_notes(caller_nn);
 608     return;
 609   }
 610 
 611   entry_map = map();  // capture any changes performed by method setup code
 612   assert(jvms()->endoff() == map()->req(), "map matches JVMS layout");
 613 
 614   // We begin parsing as if we have just encountered a jump to the
 615   // method entry.
 616   Block* entry_block = start_block();
 617   assert(entry_block->start() == (is_osr_parse() ? osr_bci() : 0), "");
 618   set_map_clone(entry_map);
 619   merge_common(entry_block, entry_block->next_path_num());
 620 
 621 #ifndef PRODUCT
 622   BytecodeParseHistogram *parse_histogram_obj = new (C->env()->arena()) BytecodeParseHistogram(this, C);
 623   set_parse_histogram( parse_histogram_obj );
 624 #endif
 625 
 626   // Parse all the basic blocks.
 627   do_all_blocks();
 628 
 629   // Check for bailouts during conversion to graph
 630   if (failing()) {
 631     if (log)  log->done("parse");
 632     return;
 633   }
 634 
 635   // Fix up all exiting control flow.
 636   set_map(entry_map);
 637   do_exits();
 638 
 639   // Only reset this now, to make sure that debug information emitted
 640   // for exiting control flow still refers to the inlined method.
 641   C->set_default_node_notes(caller_nn);
 642 
 643   if (log)  log->done("parse nodes='%d' live='%d' memory='%zu'",
 644                       C->unique(), C->live_nodes(), C->node_arena()->used());
 645 }
 646 
 647 //---------------------------do_all_blocks-------------------------------------
 648 void Parse::do_all_blocks() {
 649   bool has_irreducible = flow()->has_irreducible_entry();
 650 
 651   // Walk over all blocks in Reverse Post-Order.
 652   while (true) {
 653     bool progress = false;
 654     for (int rpo = 0; rpo < block_count(); rpo++) {
 655       Block* block = rpo_at(rpo);
 656 
 657       if (block->is_parsed()) continue;
 658 
 659       if (!block->is_merged()) {
 660         // Dead block, no state reaches this block
 661         continue;
 662       }
 663 
 664       // Prepare to parse this block.
 665       load_state_from(block);
 666 
 667       if (stopped()) {
 668         // Block is dead.
 669         continue;
 670       }
 671 
 672       NOT_PRODUCT(blocks_parsed++);
 673 
 674       progress = true;
 675       if (block->is_loop_head() || block->is_handler() || (has_irreducible && !block->is_ready())) {
 676         // Not all preds have been parsed.  We must build phis everywhere.
 677         // (Note that dead locals do not get phis built, ever.)
 678         ensure_phis_everywhere();
 679 
 680         if (block->is_SEL_head()) {
 681           // Add predicate to single entry (not irreducible) loop head.
 682           assert(!block->has_merged_backedge(), "only entry paths should be merged for now");
 683           // Predicates may have been added after a dominating if
 684           if (!block->has_predicates()) {
 685             // Need correct bci for predicate.
 686             // It is fine to set it here since do_one_block() will set it anyway.
 687             set_parse_bci(block->start());
 688             add_parse_predicates();
 689           }
 690           // Add new region for back branches.
 691           int edges = block->pred_count() - block->preds_parsed() + 1; // +1 for original region
 692           RegionNode *r = new RegionNode(edges+1);
 693           _gvn.set_type(r, Type::CONTROL);
 694           record_for_igvn(r);
 695           r->init_req(edges, control());
 696           set_control(r);
 697           block->copy_irreducible_status_to(r, jvms());
 698           // Add new phis.
 699           ensure_phis_everywhere();
 700         }
 701 
 702         // Leave behind an undisturbed copy of the map, for future merges.
 703         set_map(clone_map());
 704       }
 705 
 706       if (control()->is_Region() && !block->is_loop_head() && !has_irreducible && !block->is_handler()) {
 707         // In the absence of irreducible loops, the Region and Phis
 708         // associated with a merge that doesn't involve a backedge can
 709         // be simplified now since the RPO parsing order guarantees
 710         // that any path which was supposed to reach here has already
 711         // been parsed or must be dead.
 712         Node* c = control();
 713         Node* result = _gvn.transform(control());
 714         if (c != result && TraceOptoParse) {
 715           tty->print_cr("Block #%d replace %d with %d", block->rpo(), c->_idx, result->_idx);
 716         }
 717         if (result != top()) {
 718           record_for_igvn(result);
 719         }
 720       }
 721 
 722       // Parse the block.
 723       do_one_block();
 724 
 725       // Check for bailouts.
 726       if (failing())  return;
 727     }
 728 
 729     // with irreducible loops multiple passes might be necessary to parse everything
 730     if (!has_irreducible || !progress) {
 731       break;
 732     }
 733   }
 734 
 735 #ifndef PRODUCT
 736   blocks_seen += block_count();
 737 
 738   // Make sure there are no half-processed blocks remaining.
 739   // Every remaining unprocessed block is dead and may be ignored now.
 740   for (int rpo = 0; rpo < block_count(); rpo++) {
 741     Block* block = rpo_at(rpo);
 742     if (!block->is_parsed()) {
 743       if (TraceOptoParse) {
 744         tty->print_cr("Skipped dead block %d at bci:%d", rpo, block->start());
 745       }
 746       assert(!block->is_merged(), "no half-processed blocks");
 747     }
 748   }
 749 #endif
 750 }
 751 
 752 static Node* mask_int_value(Node* v, BasicType bt, PhaseGVN* gvn) {
 753   switch (bt) {
 754   case T_BYTE:
 755     v = gvn->transform(new LShiftINode(v, gvn->intcon(24)));
 756     v = gvn->transform(new RShiftINode(v, gvn->intcon(24)));
 757     break;
 758   case T_SHORT:
 759     v = gvn->transform(new LShiftINode(v, gvn->intcon(16)));
 760     v = gvn->transform(new RShiftINode(v, gvn->intcon(16)));
 761     break;
 762   case T_CHAR:
 763     v = gvn->transform(new AndINode(v, gvn->intcon(0xFFFF)));
 764     break;
 765   case T_BOOLEAN:
 766     v = gvn->transform(new AndINode(v, gvn->intcon(0x1)));
 767     break;
 768   default:
 769     break;
 770   }
 771   return v;
 772 }
 773 
 774 //-------------------------------build_exits----------------------------------
 775 // Build normal and exceptional exit merge points.
 776 void Parse::build_exits() {
 777   // make a clone of caller to prevent sharing of side-effects
 778   _exits.set_map(_exits.clone_map());
 779   _exits.clean_stack(_exits.sp());
 780   _exits.sync_jvms();
 781 
 782   RegionNode* region = new RegionNode(1);
 783   record_for_igvn(region);
 784   gvn().set_type_bottom(region);
 785   _exits.set_control(region);
 786 
 787   // Note:  iophi and memphi are not transformed until do_exits.
 788   Node* iophi  = new PhiNode(region, Type::ABIO);
 789   Node* memphi = new PhiNode(region, Type::MEMORY, TypePtr::BOTTOM);
 790   gvn().set_type_bottom(iophi);
 791   gvn().set_type_bottom(memphi);
 792   _exits.set_i_o(iophi);
 793   _exits.set_all_memory(memphi);
 794 
 795   // Add a return value to the exit state.  (Do not push it yet.)
 796   if (tf()->range()->cnt() > TypeFunc::Parms) {
 797     const Type* ret_type = tf()->range()->field_at(TypeFunc::Parms);
 798     if (ret_type->isa_int()) {
 799       BasicType ret_bt = method()->return_type()->basic_type();
 800       if (ret_bt == T_BOOLEAN ||
 801           ret_bt == T_CHAR ||
 802           ret_bt == T_BYTE ||
 803           ret_bt == T_SHORT) {
 804         ret_type = TypeInt::INT;
 805       }
 806     }
 807 
 808     // Don't "bind" an unloaded return klass to the ret_phi. If the klass
 809     // becomes loaded during the subsequent parsing, the loaded and unloaded
 810     // types will not join when we transform and push in do_exits().
 811     const TypeOopPtr* ret_oop_type = ret_type->isa_oopptr();
 812     if (ret_oop_type && !ret_oop_type->is_loaded()) {
 813       ret_type = TypeOopPtr::BOTTOM;
 814     }
 815     int         ret_size = type2size[ret_type->basic_type()];
 816     Node*       ret_phi  = new PhiNode(region, ret_type);
 817     gvn().set_type_bottom(ret_phi);
 818     _exits.ensure_stack(ret_size);
 819     assert((int)(tf()->range()->cnt() - TypeFunc::Parms) == ret_size, "good tf range");
 820     assert(method()->return_type()->size() == ret_size, "tf agrees w/ method");
 821     _exits.set_argument(0, ret_phi);  // here is where the parser finds it
 822     // Note:  ret_phi is not yet pushed, until do_exits.
 823   }
 824 }
 825 
 826 
 827 //----------------------------build_start_state-------------------------------
 828 // Construct a state which contains only the incoming arguments from an
 829 // unknown caller.  The method & bci will be null & InvocationEntryBci.
 830 JVMState* Compile::build_start_state(StartNode* start, const TypeFunc* tf) {
 831   int        arg_size = tf->domain()->cnt();
 832   int        max_size = MAX2(arg_size, (int)tf->range()->cnt());
 833   JVMState*  jvms     = new (this) JVMState(max_size - TypeFunc::Parms);
 834   SafePointNode* map  = new SafePointNode(max_size, jvms);
 835   record_for_igvn(map);
 836   assert(arg_size == TypeFunc::Parms + (is_osr_compilation() ? 1 : method()->arg_size()), "correct arg_size");
 837   Node_Notes* old_nn = default_node_notes();
 838   if (old_nn != nullptr && has_method()) {
 839     Node_Notes* entry_nn = old_nn->clone(this);
 840     JVMState* entry_jvms = new(this) JVMState(method(), old_nn->jvms());
 841     entry_jvms->set_offsets(0);
 842     entry_jvms->set_bci(entry_bci());
 843     entry_nn->set_jvms(entry_jvms);
 844     set_default_node_notes(entry_nn);
 845   }
 846   uint i;
 847   for (i = 0; i < (uint)arg_size; i++) {
 848     Node* parm = initial_gvn()->transform(new ParmNode(start, i));
 849     map->init_req(i, parm);
 850     // Record all these guys for later GVN.
 851     record_for_igvn(parm);
 852   }
 853   for (; i < map->req(); i++) {
 854     map->init_req(i, top());
 855   }
 856   assert(jvms->argoff() == TypeFunc::Parms, "parser gets arguments here");
 857   set_default_node_notes(old_nn);
 858   jvms->set_map(map);
 859   return jvms;
 860 }
 861 
 862 //-----------------------------make_node_notes---------------------------------
 863 Node_Notes* Parse::make_node_notes(Node_Notes* caller_nn) {
 864   if (caller_nn == nullptr)  return nullptr;
 865   Node_Notes* nn = caller_nn->clone(C);
 866   JVMState* caller_jvms = nn->jvms();
 867   JVMState* jvms = new (C) JVMState(method(), caller_jvms);
 868   jvms->set_offsets(0);
 869   jvms->set_bci(_entry_bci);
 870   nn->set_jvms(jvms);
 871   return nn;
 872 }
 873 
 874 
 875 //--------------------------return_values--------------------------------------
 876 void Compile::return_values(JVMState* jvms) {
 877   GraphKit kit(jvms);
 878   Node* ret = new ReturnNode(TypeFunc::Parms,
 879                              kit.control(),
 880                              kit.i_o(),
 881                              kit.reset_memory(),
 882                              kit.frameptr(),
 883                              kit.returnadr());
 884   // Add zero or 1 return values
 885   int ret_size = tf()->range()->cnt() - TypeFunc::Parms;
 886   if (ret_size > 0) {
 887     kit.inc_sp(-ret_size);  // pop the return value(s)
 888     kit.sync_jvms();
 889     ret->add_req(kit.argument(0));
 890     // Note:  The second dummy edge is not needed by a ReturnNode.
 891   }
 892   // bind it to root
 893   root()->add_req(ret);
 894   record_for_igvn(ret);
 895   initial_gvn()->transform(ret);
 896 }
 897 
 898 //------------------------rethrow_exceptions-----------------------------------
 899 // Bind all exception states in the list into a single RethrowNode.
 900 void Compile::rethrow_exceptions(JVMState* jvms) {
 901   GraphKit kit(jvms);
 902   if (!kit.has_exceptions())  return;  // nothing to generate
 903   // Load my combined exception state into the kit, with all phis transformed:
 904   SafePointNode* ex_map = kit.combine_and_pop_all_exception_states();
 905   Node* ex_oop = kit.use_exception_state(ex_map);
 906   RethrowNode* exit = new RethrowNode(kit.control(),
 907                                       kit.i_o(), kit.reset_memory(),
 908                                       kit.frameptr(), kit.returnadr(),
 909                                       // like a return but with exception input
 910                                       ex_oop);
 911   // bind to root
 912   root()->add_req(exit);
 913   record_for_igvn(exit);
 914   initial_gvn()->transform(exit);
 915 }
 916 
 917 //---------------------------do_exceptions-------------------------------------
 918 // Process exceptions arising from the current bytecode.
 919 // Send caught exceptions to the proper handler within this method.
 920 // Unhandled exceptions feed into _exit.
 921 void Parse::do_exceptions() {
 922   if (!has_exceptions())  return;
 923 
 924   if (failing()) {
 925     // Pop them all off and throw them away.
 926     while (pop_exception_state() != nullptr) ;
 927     return;
 928   }
 929 
 930   PreserveJVMState pjvms(this, false);
 931 
 932   SafePointNode* ex_map;
 933   while ((ex_map = pop_exception_state()) != nullptr) {
 934     if (!method()->has_exception_handlers()) {
 935       // Common case:  Transfer control outward.
 936       // Doing it this early allows the exceptions to common up
 937       // even between adjacent method calls.
 938       throw_to_exit(ex_map);
 939     } else {
 940       // Have to look at the exception first.
 941       assert(stopped(), "catch_inline_exceptions trashes the map");
 942       catch_inline_exceptions(ex_map);
 943       stop_and_kill_map();      // we used up this exception state; kill it
 944     }
 945   }
 946 
 947   // We now return to our regularly scheduled program:
 948 }
 949 
 950 //---------------------------throw_to_exit-------------------------------------
 951 // Merge the given map into an exception exit from this method.
 952 // The exception exit will handle any unlocking of receiver.
 953 // The ex_oop must be saved within the ex_map, unlike merge_exception.
 954 void Parse::throw_to_exit(SafePointNode* ex_map) {
 955   // Pop the JVMS to (a copy of) the caller.
 956   GraphKit caller;
 957   caller.set_map_clone(_caller->map());
 958   caller.set_bci(_caller->bci());
 959   caller.set_sp(_caller->sp());
 960   // Copy out the standard machine state:
 961   for (uint i = 0; i < TypeFunc::Parms; i++) {
 962     caller.map()->set_req(i, ex_map->in(i));
 963   }
 964   if (ex_map->has_replaced_nodes()) {
 965     _replaced_nodes_for_exceptions = true;
 966   }
 967   caller.map()->transfer_replaced_nodes_from(ex_map, _new_idx);
 968   // ...and the exception:
 969   Node*          ex_oop        = saved_ex_oop(ex_map);
 970   SafePointNode* caller_ex_map = caller.make_exception_state(ex_oop);
 971   // Finally, collect the new exception state in my exits:
 972   _exits.add_exception_state(caller_ex_map);
 973 }
 974 
 975 //------------------------------do_exits---------------------------------------
 976 void Parse::do_exits() {
 977   set_parse_bci(InvocationEntryBci);
 978 
 979   // Now peephole on the return bits
 980   Node* region = _exits.control();
 981   _exits.set_control(gvn().transform(region));
 982 
 983   Node* iophi = _exits.i_o();
 984   _exits.set_i_o(gvn().transform(iophi));
 985 
 986   // Figure out if we need to emit the trailing barrier. The barrier is only
 987   // needed in the constructors, and only in three cases:
 988   //
 989   // 1. The constructor wrote a final or a @Stable field. All these
 990   //    initializations must be ordered before any code after the constructor
 991   //    publishes the reference to the newly constructed object. Rather
 992   //    than wait for the publication, we simply block the writes here.
 993   //    Rather than put a barrier on only those writes which are required
 994   //    to complete, we force all writes to complete.
 995   //
 996   // 2. Experimental VM option is used to force the barrier if any field
 997   //    was written out in the constructor.
 998   //
 999   // 3. On processors which are not CPU_MULTI_COPY_ATOMIC (e.g. PPC64),
1000   //    support_IRIW_for_not_multiple_copy_atomic_cpu selects that
1001   //    MemBarVolatile is used before volatile load instead of after volatile
1002   //    store, so there's no barrier after the store.
1003   //    We want to guarantee the same behavior as on platforms with total store
1004   //    order, although this is not required by the Java memory model.
1005   //    In this case, we want to enforce visibility of volatile field
1006   //    initializations which are performed in constructors.
1007   //    So as with finals, we add a barrier here.
1008   //
1009   // "All bets are off" unless the first publication occurs after a
1010   // normal return from the constructor.  We do not attempt to detect
1011   // such unusual early publications.  But no barrier is needed on
1012   // exceptional returns, since they cannot publish normally.
1013   //
1014   if (method()->is_object_initializer() &&
1015        (wrote_final() || wrote_stable() ||
1016          (AlwaysSafeConstructors && wrote_fields()) ||
1017          (support_IRIW_for_not_multiple_copy_atomic_cpu && wrote_volatile()))) {
1018     Node* recorded_alloc = alloc_with_final_or_stable();
1019     _exits.insert_mem_bar(UseStoreStoreForCtor ? Op_MemBarStoreStore : Op_MemBarRelease,
1020                           recorded_alloc);
1021 
1022     // If Memory barrier is created for final fields write
1023     // and allocation node does not escape the initialize method,
1024     // then barrier introduced by allocation node can be removed.
1025     if (DoEscapeAnalysis && (recorded_alloc != nullptr)) {
1026       AllocateNode* alloc = AllocateNode::Ideal_allocation(recorded_alloc);
1027       alloc->compute_MemBar_redundancy(method());
1028     }
1029     if (PrintOpto && (Verbose || WizardMode)) {
1030       method()->print_name();
1031       tty->print_cr(" writes finals/@Stable and needs a memory barrier");
1032     }
1033   }
1034 
1035   for (MergeMemStream mms(_exits.merged_memory()); mms.next_non_empty(); ) {
1036     // transform each slice of the original memphi:
1037     mms.set_memory(_gvn.transform(mms.memory()));
1038   }
1039   // Clean up input MergeMems created by transforming the slices
1040   _gvn.transform(_exits.merged_memory());
1041 
1042   if (tf()->range()->cnt() > TypeFunc::Parms) {
1043     const Type* ret_type = tf()->range()->field_at(TypeFunc::Parms);
1044     Node*       ret_phi  = _gvn.transform( _exits.argument(0) );
1045     if (!_exits.control()->is_top() && _gvn.type(ret_phi)->empty()) {
1046       // If the type we set for the ret_phi in build_exits() is too optimistic and
1047       // the ret_phi is top now, there's an extremely small chance that it may be due to class
1048       // loading.  It could also be due to an error, so mark this method as not compilable because
1049       // otherwise this could lead to an infinite compile loop.
1050       // In any case, this code path is rarely (and never in my testing) reached.
1051       C->record_method_not_compilable("Can't determine return type.");
1052       return;
1053     }
1054     if (ret_type->isa_int()) {
1055       BasicType ret_bt = method()->return_type()->basic_type();
1056       ret_phi = mask_int_value(ret_phi, ret_bt, &_gvn);
1057     }
1058     _exits.push_node(ret_type->basic_type(), ret_phi);
1059   }
1060 
1061   // Note:  Logic for creating and optimizing the ReturnNode is in Compile.
1062 
1063   // Unlock along the exceptional paths.
1064   // This is done late so that we can common up equivalent exceptions
1065   // (e.g., null checks) arising from multiple points within this method.
1066   // See GraphKit::add_exception_state, which performs the commoning.
1067   bool do_synch = method()->is_synchronized();
1068 
1069   // record exit from a method if compiled while Dtrace is turned on.
1070   if (do_synch || C->env()->dtrace_method_probes() || _replaced_nodes_for_exceptions) {
1071     // First move the exception list out of _exits:
1072     GraphKit kit(_exits.transfer_exceptions_into_jvms());
1073     SafePointNode* normal_map = kit.map();  // keep this guy safe
1074     // Now re-collect the exceptions into _exits:
1075     SafePointNode* ex_map;
1076     while ((ex_map = kit.pop_exception_state()) != nullptr) {
1077       Node* ex_oop = kit.use_exception_state(ex_map);
1078       // Force the exiting JVM state to have this method at InvocationEntryBci.
1079       // The exiting JVM state is otherwise a copy of the calling JVMS.
1080       JVMState* caller = kit.jvms();
1081       JVMState* ex_jvms = caller->clone_shallow(C);
1082       ex_jvms->bind_map(kit.clone_map());
1083       ex_jvms->set_bci(   InvocationEntryBci);
1084       kit.set_jvms(ex_jvms);
1085       if (do_synch) {
1086         // Add on the synchronized-method box/object combo
1087         kit.map()->push_monitor(_synch_lock);
1088         // Unlock!
1089         kit.shared_unlock(_synch_lock->box_node(), _synch_lock->obj_node());
1090       }
1091       if (C->env()->dtrace_method_probes()) {
1092         kit.make_dtrace_method_exit(method());
1093       }
1094       if (_replaced_nodes_for_exceptions) {
1095         kit.map()->apply_replaced_nodes(_new_idx);
1096       }
1097       // Done with exception-path processing.
1098       ex_map = kit.make_exception_state(ex_oop);
1099       assert(ex_jvms->same_calls_as(ex_map->jvms()), "sanity");
1100       // Pop the last vestige of this method:
1101       caller->clone_shallow(C)->bind_map(ex_map);
1102       _exits.push_exception_state(ex_map);
1103     }
1104     assert(_exits.map() == normal_map, "keep the same return state");
1105   }
1106 
1107   {
1108     // Capture very early exceptions (receiver null checks) from caller JVMS
1109     GraphKit caller(_caller);
1110     SafePointNode* ex_map;
1111     while ((ex_map = caller.pop_exception_state()) != nullptr) {
1112       _exits.add_exception_state(ex_map);
1113     }
1114   }
1115   _exits.map()->apply_replaced_nodes(_new_idx);
1116 }
1117 
1118 //-----------------------------create_entry_map-------------------------------
1119 // Initialize our parser map to contain the types at method entry.
1120 // For OSR, the map contains a single RawPtr parameter.
1121 // Initial monitor locking for sync. methods is performed by do_method_entry.
1122 SafePointNode* Parse::create_entry_map() {
1123   // Check for really stupid bail-out cases.
1124   uint len = TypeFunc::Parms + method()->max_locals() + method()->max_stack();
1125   if (len >= 32760) {
1126     // Bailout expected, this is a very rare edge case.
1127     C->record_method_not_compilable("too many local variables");
1128     return nullptr;
1129   }
1130 
1131   // clear current replaced nodes that are of no use from here on (map was cloned in build_exits).
1132   _caller->map()->delete_replaced_nodes();
1133 
1134   // If this is an inlined method, we may have to do a receiver null check.
1135   if (_caller->has_method() && is_normal_parse() && !method()->is_static()) {
1136     GraphKit kit(_caller);
1137     kit.null_check_receiver_before_call(method());
1138     _caller = kit.transfer_exceptions_into_jvms();
1139     if (kit.stopped()) {
1140       _exits.add_exception_states_from(_caller);
1141       _exits.set_jvms(_caller);
1142       return nullptr;
1143     }
1144   }
1145 
1146   assert(method() != nullptr, "parser must have a method");
1147 
1148   // Create an initial safepoint to hold JVM state during parsing
1149   JVMState* jvms = new (C) JVMState(method(), _caller->has_method() ? _caller : nullptr);
1150   set_map(new SafePointNode(len, jvms));
1151 
1152   // Capture receiver info for compiled lambda forms.
1153   if (method()->is_compiled_lambda_form()) {
1154     ciInstance* recv_info = _caller->compute_receiver_info(method());
1155     jvms->set_receiver_info(recv_info);
1156   }
1157 
1158   jvms->set_map(map());
1159   record_for_igvn(map());
1160   assert(jvms->endoff() == len, "correct jvms sizing");
1161 
1162   SafePointNode* inmap = _caller->map();
1163   assert(inmap != nullptr, "must have inmap");
1164   // In case of null check on receiver above
1165   map()->transfer_replaced_nodes_from(inmap, _new_idx);
1166 
1167   uint i;
1168 
1169   // Pass thru the predefined input parameters.
1170   for (i = 0; i < TypeFunc::Parms; i++) {
1171     map()->init_req(i, inmap->in(i));
1172   }
1173 
1174   if (depth() == 1) {
1175     assert(map()->memory()->Opcode() == Op_Parm, "");
1176     // Insert the memory aliasing node
1177     set_all_memory(reset_memory());
1178   }
1179   assert(merged_memory(), "");
1180 
1181   // Now add the locals which are initially bound to arguments:
1182   uint arg_size = tf()->domain()->cnt();
1183   ensure_stack(arg_size - TypeFunc::Parms);  // OSR methods have funny args
1184   for (i = TypeFunc::Parms; i < arg_size; i++) {
1185     map()->init_req(i, inmap->argument(_caller, i - TypeFunc::Parms));
1186   }
1187 
1188   // Clear out the rest of the map (locals and stack)
1189   for (i = arg_size; i < len; i++) {
1190     map()->init_req(i, top());
1191   }
1192 
1193   SafePointNode* entry_map = stop();
1194   return entry_map;
1195 }
1196 
1197 //-----------------------------do_method_entry--------------------------------
1198 // Emit any code needed in the pseudo-block before BCI zero.
1199 // The main thing to do is lock the receiver of a synchronized method.
1200 void Parse::do_method_entry() {
1201   set_parse_bci(InvocationEntryBci); // Pseudo-BCP
1202   set_sp(0);                         // Java Stack Pointer
1203 
1204   NOT_PRODUCT( count_compiled_calls(true/*at_method_entry*/, false/*is_inline*/); )
1205 
1206   if (C->env()->dtrace_method_probes()) {
1207     make_dtrace_method_entry(method());
1208   }
1209 
1210 #ifdef ASSERT
1211   // Narrow receiver type when it is too broad for the method being parsed.
1212   if (!method()->is_static()) {
1213     ciInstanceKlass* callee_holder = method()->holder();
1214     const Type* holder_type = TypeInstPtr::make(TypePtr::BotPTR, callee_holder, Type::trust_interfaces);
1215 
1216     Node* receiver_obj = local(0);
1217     const TypeInstPtr* receiver_type = _gvn.type(receiver_obj)->isa_instptr();
1218 
1219     if (receiver_type != nullptr && !receiver_type->higher_equal(holder_type)) {
1220       // Receiver should always be a subtype of callee holder.
1221       // But, since C2 type system doesn't properly track interfaces,
1222       // the invariant can't be expressed in the type system for default methods.
1223       // Example: for unrelated C <: I and D <: I, (C `meet` D) = Object </: I.
1224       assert(callee_holder->is_interface(), "missing subtype check");
1225 
1226       // Perform dynamic receiver subtype check against callee holder class w/ a halt on failure.
1227       Node* holder_klass = _gvn.makecon(TypeKlassPtr::make(callee_holder, Type::trust_interfaces));
1228       Node* not_subtype_ctrl = gen_subtype_check(receiver_obj, holder_klass);
1229       assert(!stopped(), "not a subtype");
1230 
1231       halt(not_subtype_ctrl, frameptr(), "failed receiver subtype check");
1232     }
1233   }
1234 #endif // ASSERT
1235 
1236   // If the method is synchronized, we need to construct a lock node, attach
1237   // it to the Start node, and pin it there.
1238   if (method()->is_synchronized()) {
1239     // Insert a FastLockNode right after the Start which takes as arguments
1240     // the current thread pointer, the "this" pointer & the address of the
1241     // stack slot pair used for the lock.  The "this" pointer is a projection
1242     // off the start node, but the locking spot has to be constructed by
1243     // creating a ConLNode of 0, and boxing it with a BoxLockNode.  The BoxLockNode
1244     // becomes the second argument to the FastLockNode call.  The
1245     // FastLockNode becomes the new control parent to pin it to the start.
1246 
1247     // Setup Object Pointer
1248     Node *lock_obj = nullptr;
1249     if (method()->is_static()) {
1250       ciInstance* mirror = _method->holder()->java_mirror();
1251       const TypeInstPtr *t_lock = TypeInstPtr::make(mirror);
1252       lock_obj = makecon(t_lock);
1253     } else {                  // Else pass the "this" pointer,
1254       lock_obj = local(0);    // which is Parm0 from StartNode
1255     }
1256     // Clear out dead values from the debug info.
1257     kill_dead_locals();
1258     // Build the FastLockNode
1259     _synch_lock = shared_lock(lock_obj);
1260     // Check for bailout in shared_lock
1261     if (failing()) { return; }
1262   }
1263 
1264   // Feed profiling data for parameters to the type system so it can
1265   // propagate it as speculative types
1266   record_profiled_parameters_for_speculation();
1267 }
1268 
1269 //------------------------------init_blocks------------------------------------
1270 // Initialize our parser map to contain the types/monitors at method entry.
1271 void Parse::init_blocks() {
1272   // Create the blocks.
1273   _block_count = flow()->block_count();
1274   _blocks = NEW_RESOURCE_ARRAY(Block, _block_count);
1275 
1276   // Initialize the structs.
1277   for (int rpo = 0; rpo < block_count(); rpo++) {
1278     Block* block = rpo_at(rpo);
1279     new(block) Block(this, rpo);
1280   }
1281 
1282   // Collect predecessor and successor information.
1283   for (int rpo = 0; rpo < block_count(); rpo++) {
1284     Block* block = rpo_at(rpo);
1285     block->init_graph(this);
1286   }
1287 }
1288 
1289 //-------------------------------init_node-------------------------------------
1290 Parse::Block::Block(Parse* outer, int rpo) : _live_locals() {
1291   _flow = outer->flow()->rpo_at(rpo);
1292   _pred_count = 0;
1293   _preds_parsed = 0;
1294   _count = 0;
1295   _is_parsed = false;
1296   _is_handler = false;
1297   _has_merged_backedge = false;
1298   _start_map = nullptr;
1299   _has_predicates = false;
1300   _num_successors = 0;
1301   _all_successors = 0;
1302   _successors = nullptr;
1303   assert(pred_count() == 0 && preds_parsed() == 0, "sanity");
1304   assert(!(is_merged() || is_parsed() || is_handler() || has_merged_backedge()), "sanity");
1305   assert(_live_locals.size() == 0, "sanity");
1306 
1307   // entry point has additional predecessor
1308   if (flow()->is_start())  _pred_count++;
1309   assert(flow()->is_start() == (this == outer->start_block()), "");
1310 }
1311 
1312 //-------------------------------init_graph------------------------------------
1313 void Parse::Block::init_graph(Parse* outer) {
1314   // Create the successor list for this parser block.
1315   GrowableArray<ciTypeFlow::Block*>* tfs = flow()->successors();
1316   GrowableArray<ciTypeFlow::Block*>* tfe = flow()->exceptions();
1317   int ns = tfs->length();
1318   int ne = tfe->length();
1319   _num_successors = ns;
1320   _all_successors = ns+ne;
1321   _successors = (ns+ne == 0) ? nullptr : NEW_RESOURCE_ARRAY(Block*, ns+ne);
1322   int p = 0;
1323   for (int i = 0; i < ns+ne; i++) {
1324     ciTypeFlow::Block* tf2 = (i < ns) ? tfs->at(i) : tfe->at(i-ns);
1325     Block* block2 = outer->rpo_at(tf2->rpo());
1326     _successors[i] = block2;
1327 
1328     // Accumulate pred info for the other block, too.
1329     // Note: We also need to set _pred_count for exception blocks since they could
1330     // also have normal predecessors (reached without athrow by an explicit jump).
1331     // This also means that next_path_num can be called along exception paths.
1332     block2->_pred_count++;
1333     if (i >= ns) {
1334       block2->_is_handler = true;
1335     }
1336 
1337     #ifdef ASSERT
1338     // A block's successors must be distinguishable by BCI.
1339     // That is, no bytecode is allowed to branch to two different
1340     // clones of the same code location.
1341     for (int j = 0; j < i; j++) {
1342       Block* block1 = _successors[j];
1343       if (block1 == block2)  continue;  // duplicates are OK
1344       assert(block1->start() != block2->start(), "successors have unique bcis");
1345     }
1346     #endif
1347   }
1348 }
1349 
1350 //---------------------------successor_for_bci---------------------------------
1351 Parse::Block* Parse::Block::successor_for_bci(int bci) {
1352   for (int i = 0; i < all_successors(); i++) {
1353     Block* block2 = successor_at(i);
1354     if (block2->start() == bci)  return block2;
1355   }
1356   // We can actually reach here if ciTypeFlow traps out a block
1357   // due to an unloaded class, and concurrently with compilation the
1358   // class is then loaded, so that a later phase of the parser is
1359   // able to see more of the bytecode CFG.  Or, the flow pass and
1360   // the parser can have a minor difference of opinion about executability
1361   // of bytecodes.  For example, "obj.field = null" is executable even
1362   // if the field's type is an unloaded class; the flow pass used to
1363   // make a trap for such code.
1364   return nullptr;
1365 }
1366 
1367 
1368 //-----------------------------stack_type_at-----------------------------------
1369 const Type* Parse::Block::stack_type_at(int i) const {
1370   return get_type(flow()->stack_type_at(i));
1371 }
1372 
1373 
1374 //-----------------------------local_type_at-----------------------------------
1375 const Type* Parse::Block::local_type_at(int i) const {
1376   // Make dead locals fall to bottom.
1377   if (_live_locals.size() == 0) {
1378     MethodLivenessResult live_locals = flow()->outer()->method()->liveness_at_bci(start());
1379     // This bitmap can be zero length if we saw a breakpoint.
1380     // In such cases, pretend they are all live.
1381     ((Block*)this)->_live_locals = live_locals;
1382   }
1383   if (_live_locals.size() > 0 && !_live_locals.at(i))
1384     return Type::BOTTOM;
1385 
1386   return get_type(flow()->local_type_at(i));
1387 }
1388 
1389 
1390 #ifndef PRODUCT
1391 
1392 //----------------------------name_for_bc--------------------------------------
1393 // helper method for BytecodeParseHistogram
1394 static const char* name_for_bc(int i) {
1395   return Bytecodes::is_defined(i) ? Bytecodes::name(Bytecodes::cast(i)) : "xxxunusedxxx";
1396 }
1397 
1398 //----------------------------BytecodeParseHistogram------------------------------------
1399 Parse::BytecodeParseHistogram::BytecodeParseHistogram(Parse *p, Compile *c) {
1400   _parser   = p;
1401   _compiler = c;
1402   if( ! _initialized ) { _initialized = true; reset(); }
1403 }
1404 
1405 //----------------------------current_count------------------------------------
1406 int Parse::BytecodeParseHistogram::current_count(BPHType bph_type) {
1407   switch( bph_type ) {
1408   case BPH_transforms: { return _parser->gvn().made_progress(); }
1409   case BPH_values:     { return _parser->gvn().made_new_values(); }
1410   default: { ShouldNotReachHere(); return 0; }
1411   }
1412 }
1413 
1414 //----------------------------initialized--------------------------------------
1415 bool Parse::BytecodeParseHistogram::initialized() { return _initialized; }
1416 
1417 //----------------------------reset--------------------------------------------
1418 void Parse::BytecodeParseHistogram::reset() {
1419   int i = Bytecodes::number_of_codes;
1420   while (i-- > 0) { _bytecodes_parsed[i] = 0; _nodes_constructed[i] = 0; _nodes_transformed[i] = 0; _new_values[i] = 0; }
1421 }
1422 
1423 //----------------------------set_initial_state--------------------------------
1424 // Record info when starting to parse one bytecode
1425 void Parse::BytecodeParseHistogram::set_initial_state( Bytecodes::Code bc ) {
1426   if( PrintParseStatistics && !_parser->is_osr_parse() ) {
1427     _initial_bytecode    = bc;
1428     _initial_node_count  = _compiler->unique();
1429     _initial_transforms  = current_count(BPH_transforms);
1430     _initial_values      = current_count(BPH_values);
1431   }
1432 }
1433 
1434 //----------------------------record_change--------------------------------
1435 // Record results of parsing one bytecode
1436 void Parse::BytecodeParseHistogram::record_change() {
1437   if( PrintParseStatistics && !_parser->is_osr_parse() ) {
1438     ++_bytecodes_parsed[_initial_bytecode];
1439     _nodes_constructed [_initial_bytecode] += (_compiler->unique() - _initial_node_count);
1440     _nodes_transformed [_initial_bytecode] += (current_count(BPH_transforms) - _initial_transforms);
1441     _new_values        [_initial_bytecode] += (current_count(BPH_values)     - _initial_values);
1442   }
1443 }
1444 
1445 
1446 //----------------------------print--------------------------------------------
1447 void Parse::BytecodeParseHistogram::print(float cutoff) {
1448   ResourceMark rm;
1449   // print profile
1450   int total  = 0;
1451   int i      = 0;
1452   for( i = 0; i < Bytecodes::number_of_codes; ++i ) { total += _bytecodes_parsed[i]; }
1453   int abs_sum = 0;
1454   tty->cr();   //0123456789012345678901234567890123456789012345678901234567890123456789
1455   tty->print_cr("Histogram of %d parsed bytecodes:", total);
1456   if( total == 0 ) { return; }
1457   tty->cr();
1458   tty->print_cr("absolute:  count of compiled bytecodes of this type");
1459   tty->print_cr("relative:  percentage contribution to compiled nodes");
1460   tty->print_cr("nodes   :  Average number of nodes constructed per bytecode");
1461   tty->print_cr("rnodes  :  Significance towards total nodes constructed, (nodes*relative)");
1462   tty->print_cr("transforms: Average amount of transform progress per bytecode compiled");
1463   tty->print_cr("values  :  Average number of node values improved per bytecode");
1464   tty->print_cr("name    :  Bytecode name");
1465   tty->cr();
1466   tty->print_cr("  absolute  relative   nodes  rnodes  transforms  values   name");
1467   tty->print_cr("----------------------------------------------------------------------");
1468   while (--i > 0) {
1469     int       abs = _bytecodes_parsed[i];
1470     float     rel = abs * 100.0F / total;
1471     float   nodes = _bytecodes_parsed[i] == 0 ? 0 : (1.0F * _nodes_constructed[i])/_bytecodes_parsed[i];
1472     float  rnodes = _bytecodes_parsed[i] == 0 ? 0 :  rel * nodes;
1473     float  xforms = _bytecodes_parsed[i] == 0 ? 0 : (1.0F * _nodes_transformed[i])/_bytecodes_parsed[i];
1474     float  values = _bytecodes_parsed[i] == 0 ? 0 : (1.0F * _new_values       [i])/_bytecodes_parsed[i];
1475     if (cutoff <= rel) {
1476       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));
1477       abs_sum += abs;
1478     }
1479   }
1480   tty->print_cr("----------------------------------------------------------------------");
1481   float rel_sum = abs_sum * 100.0F / total;
1482   tty->print_cr("%10d  %7.2f%%    (cutoff = %.2f%%)", abs_sum, rel_sum, cutoff);
1483   tty->print_cr("----------------------------------------------------------------------");
1484   tty->cr();
1485 }
1486 #endif
1487 
1488 //----------------------------load_state_from----------------------------------
1489 // Load block/map/sp.  But not do not touch iter/bci.
1490 void Parse::load_state_from(Block* block) {
1491   set_block(block);
1492   // load the block's JVM state:
1493   set_map(block->start_map());
1494   set_sp( block->start_sp());
1495 }
1496 
1497 
1498 //-----------------------------record_state------------------------------------
1499 void Parse::Block::record_state(Parse* p) {
1500   assert(!is_merged(), "can only record state once, on 1st inflow");
1501   assert(start_sp() == p->sp(), "stack pointer must agree with ciTypeFlow");
1502   set_start_map(p->stop());
1503 }
1504 
1505 
1506 //------------------------------do_one_block-----------------------------------
1507 void Parse::do_one_block() {
1508   if (TraceOptoParse) {
1509     Block *b = block();
1510     int ns = b->num_successors();
1511     int nt = b->all_successors();
1512 
1513     tty->print("Parsing block #%d at bci [%d,%d), successors:",
1514                   block()->rpo(), block()->start(), block()->limit());
1515     for (int i = 0; i < nt; i++) {
1516       tty->print((( i < ns) ? " %d" : " %d(exception block)"), b->successor_at(i)->rpo());
1517     }
1518     if (b->is_loop_head()) {
1519       tty->print("  loop head");
1520     }
1521     if (b->is_irreducible_loop_entry()) {
1522       tty->print("  irreducible");
1523     }
1524     tty->cr();
1525   }
1526 
1527   assert(block()->is_merged(), "must be merged before being parsed");
1528   block()->mark_parsed();
1529 
1530   // Set iterator to start of block.
1531   iter().reset_to_bci(block()->start());
1532 
1533   if (ProfileExceptionHandlers && block()->is_handler()) {
1534     ciMethodData* methodData = method()->method_data();
1535     if (methodData->is_mature()) {
1536       ciBitData data = methodData->exception_handler_bci_to_data(block()->start());
1537       if (!data.exception_handler_entered() || StressPrunedExceptionHandlers) {
1538         // dead catch block
1539         // Emit an uncommon trap instead of processing the block.
1540         set_parse_bci(block()->start());
1541         uncommon_trap(Deoptimization::Reason_unreached,
1542                       Deoptimization::Action_reinterpret,
1543                       nullptr, "dead catch block");
1544         return;
1545       }
1546     }
1547   }
1548 
1549   CompileLog* log = C->log();
1550 
1551   // Parse bytecodes
1552   while (!stopped() && !failing()) {
1553     iter().next();
1554 
1555     // Learn the current bci from the iterator:
1556     set_parse_bci(iter().cur_bci());
1557 
1558     if (bci() == block()->limit()) {
1559       // Do not walk into the next block until directed by do_all_blocks.
1560       merge(bci());
1561       break;
1562     }
1563     assert(bci() < block()->limit(), "bci still in block");
1564 
1565     if (log != nullptr) {
1566       // Output an optional context marker, to help place actions
1567       // that occur during parsing of this BC.  If there is no log
1568       // output until the next context string, this context string
1569       // will be silently ignored.
1570       log->set_context("bc code='%d' bci='%d'", (int)bc(), bci());
1571     }
1572 
1573     if (block()->has_trap_at(bci())) {
1574       // We must respect the flow pass's traps, because it will refuse
1575       // to produce successors for trapping blocks.
1576       int trap_index = block()->flow()->trap_index();
1577       assert(trap_index != 0, "trap index must be valid");
1578       uncommon_trap(trap_index);
1579       break;
1580     }
1581 
1582     NOT_PRODUCT( parse_histogram()->set_initial_state(bc()); );
1583 
1584 #ifdef ASSERT
1585     int pre_bc_sp = sp();
1586     int inputs, depth;
1587     bool have_se = !stopped() && compute_stack_effects(inputs, depth);
1588     assert(!have_se || pre_bc_sp >= inputs, "have enough stack to execute this BC: pre_bc_sp=%d, inputs=%d", pre_bc_sp, inputs);
1589 #endif //ASSERT
1590 
1591     do_one_bytecode();
1592     if (failing()) return;
1593 
1594     assert(!have_se || stopped() || failing() || (sp() - pre_bc_sp) == depth,
1595            "incorrect depth prediction: sp=%d, pre_bc_sp=%d, depth=%d", sp(), pre_bc_sp, depth);
1596 
1597     do_exceptions();
1598 
1599     NOT_PRODUCT( parse_histogram()->record_change(); );
1600 
1601     if (log != nullptr)
1602       log->clear_context();  // skip marker if nothing was printed
1603 
1604     // Fall into next bytecode.  Each bytecode normally has 1 sequential
1605     // successor which is typically made ready by visiting this bytecode.
1606     // If the successor has several predecessors, then it is a merge
1607     // point, starts a new basic block, and is handled like other basic blocks.
1608   }
1609 }
1610 
1611 
1612 //------------------------------merge------------------------------------------
1613 void Parse::set_parse_bci(int bci) {
1614   set_bci(bci);
1615   Node_Notes* nn = C->default_node_notes();
1616   if (nn == nullptr)  return;
1617 
1618   // Collect debug info for inlined calls unless -XX:-DebugInlinedCalls.
1619   if (!DebugInlinedCalls && depth() > 1) {
1620     return;
1621   }
1622 
1623   // Update the JVMS annotation, if present.
1624   JVMState* jvms = nn->jvms();
1625   if (jvms != nullptr && jvms->bci() != bci) {
1626     // Update the JVMS.
1627     jvms = jvms->clone_shallow(C);
1628     jvms->set_bci(bci);
1629     nn->set_jvms(jvms);
1630   }
1631 }
1632 
1633 //------------------------------merge------------------------------------------
1634 // Merge the current mapping into the basic block starting at bci
1635 void Parse::merge(int target_bci) {
1636   Block* target = successor_for_bci(target_bci);
1637   if (target == nullptr) { handle_missing_successor(target_bci); return; }
1638   assert(!target->is_ready(), "our arrival must be expected");
1639   int pnum = target->next_path_num();
1640   merge_common(target, pnum);
1641 }
1642 
1643 //-------------------------merge_new_path--------------------------------------
1644 // Merge the current mapping into the basic block, using a new path
1645 void Parse::merge_new_path(int target_bci) {
1646   Block* target = successor_for_bci(target_bci);
1647   if (target == nullptr) { handle_missing_successor(target_bci); return; }
1648   assert(!target->is_ready(), "new path into frozen graph");
1649   int pnum = target->add_new_path();
1650   merge_common(target, pnum);
1651 }
1652 
1653 //-------------------------merge_exception-------------------------------------
1654 // Merge the current mapping into the basic block starting at bci
1655 // The ex_oop must be pushed on the stack, unlike throw_to_exit.
1656 void Parse::merge_exception(int target_bci) {
1657 #ifdef ASSERT
1658   if (target_bci <= bci()) {
1659     C->set_exception_backedge();
1660   }
1661 #endif
1662   assert(sp() == 1, "must have only the throw exception on the stack");
1663   Block* target = successor_for_bci(target_bci);
1664   if (target == nullptr) { handle_missing_successor(target_bci); return; }
1665   assert(target->is_handler(), "exceptions are handled by special blocks");
1666   int pnum = target->add_new_path();
1667   merge_common(target, pnum);
1668 }
1669 
1670 //--------------------handle_missing_successor---------------------------------
1671 void Parse::handle_missing_successor(int target_bci) {
1672 #ifndef PRODUCT
1673   Block* b = block();
1674   int trap_bci = b->flow()->has_trap()? b->flow()->trap_bci(): -1;
1675   tty->print_cr("### Missing successor at bci:%d for block #%d (trap_bci:%d)", target_bci, b->rpo(), trap_bci);
1676 #endif
1677   ShouldNotReachHere();
1678 }
1679 
1680 //--------------------------merge_common---------------------------------------
1681 void Parse::merge_common(Parse::Block* target, int pnum) {
1682   if (TraceOptoParse) {
1683     tty->print("Merging state at block #%d bci:%d", target->rpo(), target->start());
1684   }
1685 
1686   // Zap extra stack slots to top
1687   assert(sp() == target->start_sp(), "");
1688   clean_stack(sp());
1689 
1690   if (!target->is_merged()) {   // No prior mapping at this bci
1691     if (TraceOptoParse) { tty->print(" with empty state");  }
1692 
1693     // If this path is dead, do not bother capturing it as a merge.
1694     // It is "as if" we had 1 fewer predecessors from the beginning.
1695     if (stopped()) {
1696       if (TraceOptoParse)  tty->print_cr(", but path is dead and doesn't count");
1697       return;
1698     }
1699 
1700     // Make a region if we know there are multiple or unpredictable inputs.
1701     // (Also, if this is a plain fall-through, we might see another region,
1702     // which must not be allowed into this block's map.)
1703     if (pnum > PhiNode::Input         // Known multiple inputs.
1704         || target->is_handler()       // These have unpredictable inputs.
1705         || target->is_loop_head()     // Known multiple inputs
1706         || control()->is_Region()) {  // We must hide this guy.
1707 
1708       int current_bci = bci();
1709       set_parse_bci(target->start()); // Set target bci
1710       if (target->is_SEL_head()) {
1711         DEBUG_ONLY( target->mark_merged_backedge(block()); )
1712         if (target->start() == 0) {
1713           // Add Parse Predicates for the special case when
1714           // there are backbranches to the method entry.
1715           add_parse_predicates();
1716         }
1717       }
1718       // Add a Region to start the new basic block.  Phis will be added
1719       // later lazily.
1720       int edges = target->pred_count();
1721       if (edges < pnum)  edges = pnum;  // might be a new path!
1722       RegionNode *r = new RegionNode(edges+1);
1723       gvn().set_type(r, Type::CONTROL);
1724       record_for_igvn(r);
1725       // zap all inputs to null for debugging (done in Node(uint) constructor)
1726       // for (int j = 1; j < edges+1; j++) { r->init_req(j, nullptr); }
1727       r->init_req(pnum, control());
1728       set_control(r);
1729       target->copy_irreducible_status_to(r, jvms());
1730       set_parse_bci(current_bci); // Restore bci
1731     }
1732 
1733     // Convert the existing Parser mapping into a mapping at this bci.
1734     store_state_to(target);
1735     assert(target->is_merged(), "do not come here twice");
1736 
1737   } else {                      // Prior mapping at this bci
1738     if (TraceOptoParse) {  tty->print(" with previous state"); }
1739 #ifdef ASSERT
1740     if (target->is_SEL_head()) {
1741       target->mark_merged_backedge(block());
1742     }
1743 #endif
1744     // We must not manufacture more phis if the target is already parsed.
1745     bool nophi = target->is_parsed();
1746 
1747     SafePointNode* newin = map();// Hang on to incoming mapping
1748     Block* save_block = block(); // Hang on to incoming block;
1749     load_state_from(target);    // Get prior mapping
1750 
1751     assert(newin->jvms()->locoff() == jvms()->locoff(), "JVMS layouts agree");
1752     assert(newin->jvms()->stkoff() == jvms()->stkoff(), "JVMS layouts agree");
1753     assert(newin->jvms()->monoff() == jvms()->monoff(), "JVMS layouts agree");
1754     assert(newin->jvms()->endoff() == jvms()->endoff(), "JVMS layouts agree");
1755 
1756     // Iterate over my current mapping and the old mapping.
1757     // Where different, insert Phi functions.
1758     // Use any existing Phi functions.
1759     assert(control()->is_Region(), "must be merging to a region");
1760     RegionNode* r = control()->as_Region();
1761 
1762     // Compute where to merge into
1763     // Merge incoming control path
1764     r->init_req(pnum, newin->control());
1765 
1766     if (pnum == 1) {            // Last merge for this Region?
1767       if (!block()->flow()->is_irreducible_loop_secondary_entry()) {
1768         Node* result = _gvn.transform(r);
1769         if (r != result && TraceOptoParse) {
1770           tty->print_cr("Block #%d replace %d with %d", block()->rpo(), r->_idx, result->_idx);
1771         }
1772       }
1773       record_for_igvn(r);
1774     }
1775 
1776     // Update all the non-control inputs to map:
1777     assert(TypeFunc::Parms == newin->jvms()->locoff(), "parser map should contain only youngest jvms");
1778     bool check_elide_phi = target->is_SEL_backedge(save_block);
1779     for (uint j = 1; j < newin->req(); j++) {
1780       Node* m = map()->in(j);   // Current state of target.
1781       Node* n = newin->in(j);   // Incoming change to target state.
1782       PhiNode* phi;
1783       if (m->is_Phi() && m->as_Phi()->region() == r)
1784         phi = m->as_Phi();
1785       else
1786         phi = nullptr;
1787       if (m != n) {             // Different; must merge
1788         switch (j) {
1789         // Frame pointer and Return Address never changes
1790         case TypeFunc::FramePtr:// Drop m, use the original value
1791         case TypeFunc::ReturnAdr:
1792           break;
1793         case TypeFunc::Memory:  // Merge inputs to the MergeMem node
1794           assert(phi == nullptr, "the merge contains phis, not vice versa");
1795           merge_memory_edges(n->as_MergeMem(), pnum, nophi);
1796           continue;
1797         default:                // All normal stuff
1798           if (phi == nullptr) {
1799             const JVMState* jvms = map()->jvms();
1800             if (EliminateNestedLocks &&
1801                 jvms->is_mon(j) && jvms->is_monitor_box(j)) {
1802               // BoxLock nodes are not commoning when EliminateNestedLocks is on.
1803               // Use old BoxLock node as merged box.
1804               assert(newin->jvms()->is_monitor_box(j), "sanity");
1805               // This assert also tests that nodes are BoxLock.
1806               assert(BoxLockNode::same_slot(n, m), "sanity");
1807               BoxLockNode* old_box = m->as_BoxLock();
1808               if (n->as_BoxLock()->is_unbalanced() && !old_box->is_unbalanced()) {
1809                 // Preserve Unbalanced status.
1810                 //
1811                 // `old_box` can have only Regular or Coarsened status
1812                 // because this code is executed only during Parse phase and
1813                 // Incremental Inlining before EA and Macro nodes elimination.
1814                 //
1815                 // Incremental Inlining is executed after IGVN optimizations
1816                 // during which BoxLock can be marked as Coarsened.
1817                 old_box->set_coarsened(); // Verifies state
1818                 old_box->set_unbalanced();
1819               }
1820               C->gvn_replace_by(n, m);
1821             } else if (!check_elide_phi || !target->can_elide_SEL_phi(j)) {
1822               phi = ensure_phi(j, nophi);
1823             }
1824           }
1825           break;
1826         }
1827       }
1828       // At this point, n might be top if:
1829       //  - there is no phi (because TypeFlow detected a conflict), or
1830       //  - the corresponding control edges is top (a dead incoming path)
1831       // It is a bug if we create a phi which sees a garbage value on a live path.
1832 
1833       if (phi != nullptr) {
1834         assert(n != top() || r->in(pnum) == top(), "live value must not be garbage");
1835         assert(phi->region() == r, "");
1836         phi->set_req(pnum, n);  // Then add 'n' to the merge
1837         if (pnum == PhiNode::Input) {
1838           // Last merge for this Phi.
1839           // So far, Phis have had a reasonable type from ciTypeFlow.
1840           // Now _gvn will join that with the meet of current inputs.
1841           // BOTTOM is never permissible here, 'cause pessimistically
1842           // Phis of pointers cannot lose the basic pointer type.
1843           DEBUG_ONLY(const Type* bt1 = phi->bottom_type());
1844           assert(bt1 != Type::BOTTOM, "should not be building conflict phis");
1845           map()->set_req(j, _gvn.transform(phi));
1846           DEBUG_ONLY(const Type* bt2 = phi->bottom_type());
1847           assert(bt2->higher_equal_speculative(bt1), "must be consistent with type-flow");
1848           record_for_igvn(phi);
1849         }
1850       }
1851     } // End of for all values to be merged
1852 
1853     if (pnum == PhiNode::Input &&
1854         !r->in(0)) {         // The occasional useless Region
1855       assert(control() == r, "");
1856       set_control(r->nonnull_req());
1857     }
1858 
1859     map()->merge_replaced_nodes_with(newin);
1860 
1861     // newin has been subsumed into the lazy merge, and is now dead.
1862     set_block(save_block);
1863 
1864     stop();                     // done with this guy, for now
1865   }
1866 
1867   if (TraceOptoParse) {
1868     tty->print_cr(" on path %d", pnum);
1869   }
1870 
1871   // Done with this parser state.
1872   assert(stopped(), "");
1873 }
1874 
1875 
1876 //--------------------------merge_memory_edges---------------------------------
1877 void Parse::merge_memory_edges(MergeMemNode* n, int pnum, bool nophi) {
1878   // (nophi means we must not create phis, because we already parsed here)
1879   assert(n != nullptr, "");
1880   // Merge the inputs to the MergeMems
1881   MergeMemNode* m = merged_memory();
1882 
1883   assert(control()->is_Region(), "must be merging to a region");
1884   RegionNode* r = control()->as_Region();
1885 
1886   PhiNode* base = nullptr;
1887   MergeMemNode* remerge = nullptr;
1888   for (MergeMemStream mms(m, n); mms.next_non_empty2(); ) {
1889     Node *p = mms.force_memory();
1890     Node *q = mms.memory2();
1891     if (mms.is_empty() && nophi) {
1892       // Trouble:  No new splits allowed after a loop body is parsed.
1893       // Instead, wire the new split into a MergeMem on the backedge.
1894       // The optimizer will sort it out, slicing the phi.
1895       if (remerge == nullptr) {
1896         guarantee(base != nullptr, "");
1897         assert(base->in(0) != nullptr, "should not be xformed away");
1898         remerge = MergeMemNode::make(base->in(pnum));
1899         gvn().set_type(remerge, Type::MEMORY);
1900         base->set_req(pnum, remerge);
1901       }
1902       remerge->set_memory_at(mms.alias_idx(), q);
1903       continue;
1904     }
1905     assert(!q->is_MergeMem(), "");
1906     PhiNode* phi;
1907     if (p != q) {
1908       phi = ensure_memory_phi(mms.alias_idx(), nophi);
1909     } else {
1910       if (p->is_Phi() && p->as_Phi()->region() == r)
1911         phi = p->as_Phi();
1912       else
1913         phi = nullptr;
1914     }
1915     // Insert q into local phi
1916     if (phi != nullptr) {
1917       assert(phi->region() == r, "");
1918       p = phi;
1919       phi->set_req(pnum, q);
1920       if (mms.at_base_memory()) {
1921         base = phi;  // delay transforming it
1922       } else if (pnum == 1) {
1923         record_for_igvn(phi);
1924         p = _gvn.transform(phi);
1925       }
1926       mms.set_memory(p);// store back through the iterator
1927     }
1928   }
1929   // Transform base last, in case we must fiddle with remerging.
1930   if (base != nullptr && pnum == 1) {
1931     record_for_igvn(base);
1932     m->set_base_memory(_gvn.transform(base));
1933   }
1934 }
1935 
1936 
1937 //------------------------ensure_phis_everywhere-------------------------------
1938 void Parse::ensure_phis_everywhere() {
1939   ensure_phi(TypeFunc::I_O);
1940 
1941   // Ensure a phi on all currently known memories.
1942   for (MergeMemStream mms(merged_memory()); mms.next_non_empty(); ) {
1943     ensure_memory_phi(mms.alias_idx());
1944     DEBUG_ONLY(mms.set_memory());  // keep the iterator happy
1945   }
1946 
1947   // Note:  This is our only chance to create phis for memory slices.
1948   // If we miss a slice that crops up later, it will have to be
1949   // merged into the base-memory phi that we are building here.
1950   // Later, the optimizer will comb out the knot, and build separate
1951   // phi-loops for each memory slice that matters.
1952 
1953   // Monitors must nest nicely and not get confused amongst themselves.
1954   // Phi-ify everything up to the monitors, though.
1955   uint monoff = map()->jvms()->monoff();
1956   uint nof_monitors = map()->jvms()->nof_monitors();
1957 
1958   assert(TypeFunc::Parms == map()->jvms()->locoff(), "parser map should contain only youngest jvms");
1959   bool check_elide_phi = block()->is_SEL_head();
1960   for (uint i = TypeFunc::Parms; i < monoff; i++) {
1961     if (!check_elide_phi || !block()->can_elide_SEL_phi(i)) {
1962       ensure_phi(i);
1963     }
1964   }
1965 
1966   // Even monitors need Phis, though they are well-structured.
1967   // This is true for OSR methods, and also for the rare cases where
1968   // a monitor object is the subject of a replace_in_map operation.
1969   // See bugs 4426707 and 5043395.
1970   for (uint m = 0; m < nof_monitors; m++) {
1971     ensure_phi(map()->jvms()->monitor_obj_offset(m));
1972   }
1973 }
1974 
1975 
1976 //-----------------------------add_new_path------------------------------------
1977 // Add a previously unaccounted predecessor to this block.
1978 int Parse::Block::add_new_path() {
1979   // If there is no map, return the lowest unused path number.
1980   if (!is_merged())  return pred_count()+1;  // there will be a map shortly
1981 
1982   SafePointNode* map = start_map();
1983   if (!map->control()->is_Region())
1984     return pred_count()+1;  // there may be a region some day
1985   RegionNode* r = map->control()->as_Region();
1986 
1987   // Add new path to the region.
1988   uint pnum = r->req();
1989   r->add_req(nullptr);
1990 
1991   for (uint i = 1; i < map->req(); i++) {
1992     Node* n = map->in(i);
1993     if (i == TypeFunc::Memory) {
1994       // Ensure a phi on all currently known memories.
1995       for (MergeMemStream mms(n->as_MergeMem()); mms.next_non_empty(); ) {
1996         Node* phi = mms.memory();
1997         if (phi->is_Phi() && phi->as_Phi()->region() == r) {
1998           assert(phi->req() == pnum, "must be same size as region");
1999           phi->add_req(nullptr);
2000         }
2001       }
2002     } else {
2003       if (n->is_Phi() && n->as_Phi()->region() == r) {
2004         assert(n->req() == pnum, "must be same size as region");
2005         n->add_req(nullptr);
2006       }
2007     }
2008   }
2009 
2010   return pnum;
2011 }
2012 
2013 //------------------------------ensure_phi-------------------------------------
2014 // Turn the idx'th entry of the current map into a Phi
2015 PhiNode *Parse::ensure_phi(int idx, bool nocreate) {
2016   SafePointNode* map = this->map();
2017   Node* region = map->control();
2018   assert(region->is_Region(), "");
2019 
2020   Node* o = map->in(idx);
2021   assert(o != nullptr, "");
2022 
2023   if (o == top())  return nullptr; // TOP always merges into TOP
2024 
2025   if (o->is_Phi() && o->as_Phi()->region() == region) {
2026     return o->as_Phi();
2027   }
2028 
2029   // Now use a Phi here for merging
2030   assert(!nocreate, "Cannot build a phi for a block already parsed.");
2031   const JVMState* jvms = map->jvms();
2032   const Type* t = nullptr;
2033   if (jvms->is_loc(idx)) {
2034     t = block()->local_type_at(idx - jvms->locoff());
2035   } else if (jvms->is_stk(idx)) {
2036     t = block()->stack_type_at(idx - jvms->stkoff());
2037   } else if (jvms->is_mon(idx)) {
2038     assert(!jvms->is_monitor_box(idx), "no phis for boxes");
2039     t = TypeInstPtr::BOTTOM; // this is sufficient for a lock object
2040   } else if ((uint)idx < TypeFunc::Parms) {
2041     t = o->bottom_type();  // Type::RETURN_ADDRESS or such-like.
2042   } else {
2043     assert(false, "no type information for this phi");
2044   }
2045 
2046   // If the type falls to bottom, then this must be a local that
2047   // is mixing ints and oops or some such.  Forcing it to top
2048   // makes it go dead.
2049   if (t == Type::BOTTOM) {
2050     map->set_req(idx, top());
2051     return nullptr;
2052   }
2053 
2054   // Do not create phis for top either.
2055   // A top on a non-null control flow must be an unused even after the.phi.
2056   if (t == Type::TOP || t == Type::HALF) {
2057     map->set_req(idx, top());
2058     return nullptr;
2059   }
2060 
2061   PhiNode* phi = PhiNode::make(region, o, t);
2062   gvn().set_type(phi, t);
2063   if (C->do_escape_analysis()) record_for_igvn(phi);
2064   map->set_req(idx, phi);
2065   return phi;
2066 }
2067 
2068 //--------------------------ensure_memory_phi----------------------------------
2069 // Turn the idx'th slice of the current memory into a Phi
2070 PhiNode *Parse::ensure_memory_phi(int idx, bool nocreate) {
2071   MergeMemNode* mem = merged_memory();
2072   Node* region = control();
2073   assert(region->is_Region(), "");
2074 
2075   Node *o = (idx == Compile::AliasIdxBot)? mem->base_memory(): mem->memory_at(idx);
2076   assert(o != nullptr && o != top(), "");
2077 
2078   PhiNode* phi;
2079   if (o->is_Phi() && o->as_Phi()->region() == region) {
2080     phi = o->as_Phi();
2081     if (phi == mem->base_memory() && idx >= Compile::AliasIdxRaw) {
2082       // clone the shared base memory phi to make a new memory split
2083       assert(!nocreate, "Cannot build a phi for a block already parsed.");
2084       const Type* t = phi->bottom_type();
2085       const TypePtr* adr_type = C->get_adr_type(idx);
2086       phi = phi->slice_memory(adr_type);
2087       gvn().set_type(phi, t);
2088     }
2089     return phi;
2090   }
2091 
2092   // Now use a Phi here for merging
2093   assert(!nocreate, "Cannot build a phi for a block already parsed.");
2094   const Type* t = o->bottom_type();
2095   const TypePtr* adr_type = C->get_adr_type(idx);
2096   phi = PhiNode::make(region, o, t, adr_type);
2097   gvn().set_type(phi, t);
2098   if (idx == Compile::AliasIdxBot)
2099     mem->set_base_memory(phi);
2100   else
2101     mem->set_memory_at(idx, phi);
2102   return phi;
2103 }
2104 
2105 //------------------------------call_register_finalizer-----------------------
2106 // Check the klass of the receiver and call register_finalizer if the
2107 // class need finalization.
2108 void Parse::call_register_finalizer() {
2109   Node* receiver = local(0);
2110   assert(receiver != nullptr && receiver->bottom_type()->isa_instptr() != nullptr,
2111          "must have non-null instance type");
2112 
2113   const TypeInstPtr *tinst = receiver->bottom_type()->isa_instptr();
2114   if (tinst != nullptr && tinst->is_loaded() && !tinst->klass_is_exact()) {
2115     // The type isn't known exactly so see if CHA tells us anything.
2116     ciInstanceKlass* ik = tinst->instance_klass();
2117     if (!Dependencies::has_finalizable_subclass(ik)) {
2118       // No finalizable subclasses so skip the dynamic check.
2119       C->dependencies()->assert_has_no_finalizable_subclasses(ik);
2120       return;
2121     }
2122   }
2123 
2124   // Insert a dynamic test for whether the instance needs
2125   // finalization.  In general this will fold up since the concrete
2126   // class is often visible so the access flags are constant.
2127   Node* klass_addr = basic_plus_adr( receiver, receiver, oopDesc::klass_offset_in_bytes() );
2128   Node* klass = _gvn.transform(LoadKlassNode::make(_gvn, immutable_memory(), klass_addr, TypeInstPtr::KLASS));
2129 
2130   Node* access_flags_addr = basic_plus_adr(top(), klass, in_bytes(Klass::misc_flags_offset()));
2131   Node* access_flags = make_load(nullptr, access_flags_addr, TypeInt::UBYTE, T_BOOLEAN, MemNode::unordered);
2132 
2133   Node* mask  = _gvn.transform(new AndINode(access_flags, intcon(KlassFlags::_misc_has_finalizer)));
2134   Node* check = _gvn.transform(new CmpINode(mask, intcon(0)));
2135   Node* test  = _gvn.transform(new BoolNode(check, BoolTest::ne));
2136 
2137   IfNode* iff = create_and_map_if(control(), test, PROB_MAX, COUNT_UNKNOWN);
2138 
2139   RegionNode* result_rgn = new RegionNode(3);
2140   record_for_igvn(result_rgn);
2141 
2142   Node *skip_register = _gvn.transform(new IfFalseNode(iff));
2143   result_rgn->init_req(1, skip_register);
2144 
2145   Node *needs_register = _gvn.transform(new IfTrueNode(iff));
2146   set_control(needs_register);
2147   if (stopped()) {
2148     // There is no slow path.
2149     result_rgn->init_req(2, top());
2150   } else {
2151     Node *call = make_runtime_call(RC_NO_LEAF,
2152                                    OptoRuntime::register_finalizer_Type(),
2153                                    OptoRuntime::register_finalizer_Java(),
2154                                    nullptr, TypePtr::BOTTOM,
2155                                    receiver);
2156     make_slow_call_ex(call, env()->Throwable_klass(), true);
2157 
2158     Node* fast_io  = call->in(TypeFunc::I_O);
2159     Node* fast_mem = call->in(TypeFunc::Memory);
2160     // These two phis are pre-filled with copies of of the fast IO and Memory
2161     Node* io_phi   = PhiNode::make(result_rgn, fast_io,  Type::ABIO);
2162     Node* mem_phi  = PhiNode::make(result_rgn, fast_mem, Type::MEMORY, TypePtr::BOTTOM);
2163 
2164     result_rgn->init_req(2, control());
2165     io_phi    ->init_req(2, i_o());
2166     mem_phi   ->init_req(2, reset_memory());
2167 
2168     set_all_memory( _gvn.transform(mem_phi) );
2169     set_i_o(        _gvn.transform(io_phi) );
2170   }
2171 
2172   set_control( _gvn.transform(result_rgn) );
2173 }
2174 
2175 // Add check to deoptimize once holder klass is fully initialized.
2176 void Parse::clinit_deopt() {
2177   assert(C->has_method(), "only for normal compilations");
2178   assert(depth() == 1, "only for main compiled method");
2179   assert(is_normal_parse(), "no barrier needed on osr entry");
2180   assert(!method()->holder()->is_not_initialized(), "initialization should have been started");
2181 
2182   set_parse_bci(0);
2183 
2184   Node* holder = makecon(TypeKlassPtr::make(method()->holder(), Type::trust_interfaces));
2185   guard_klass_being_initialized(holder);
2186 }
2187 
2188 //------------------------------return_current---------------------------------
2189 // Append current _map to _exit_return
2190 void Parse::return_current(Node* value) {
2191   if (method()->intrinsic_id() == vmIntrinsics::_Object_init) {
2192     call_register_finalizer();
2193   }
2194 
2195   // Do not set_parse_bci, so that return goo is credited to the return insn.
2196   set_bci(InvocationEntryBci);
2197   if (method()->is_synchronized()) {
2198     shared_unlock(_synch_lock->box_node(), _synch_lock->obj_node());
2199   }
2200   if (C->env()->dtrace_method_probes()) {
2201     make_dtrace_method_exit(method());
2202   }
2203   SafePointNode* exit_return = _exits.map();
2204   exit_return->in( TypeFunc::Control  )->add_req( control() );
2205   exit_return->in( TypeFunc::I_O      )->add_req( i_o    () );
2206   Node *mem = exit_return->in( TypeFunc::Memory   );
2207   for (MergeMemStream mms(mem->as_MergeMem(), merged_memory()); mms.next_non_empty2(); ) {
2208     if (mms.is_empty()) {
2209       // get a copy of the base memory, and patch just this one input
2210       const TypePtr* adr_type = mms.adr_type(C);
2211       Node* phi = mms.force_memory()->as_Phi()->slice_memory(adr_type);
2212       assert(phi->as_Phi()->region() == mms.base_memory()->in(0), "");
2213       gvn().set_type_bottom(phi);
2214       phi->del_req(phi->req()-1);  // prepare to re-patch
2215       mms.set_memory(phi);
2216     }
2217     mms.memory()->add_req(mms.memory2());
2218   }
2219 
2220   // frame pointer is always same, already captured
2221   if (value != nullptr) {
2222     // If returning oops to an interface-return, there is a silent free
2223     // cast from oop to interface allowed by the Verifier.  Make it explicit
2224     // here.
2225     Node* phi = _exits.argument(0);
2226     phi->add_req(value);
2227   }
2228 
2229   if (_first_return) {
2230     _exits.map()->transfer_replaced_nodes_from(map(), _new_idx);
2231     _first_return = false;
2232   } else {
2233     _exits.map()->merge_replaced_nodes_with(map());
2234   }
2235 
2236   stop_and_kill_map();          // This CFG path dies here
2237 }
2238 
2239 
2240 //------------------------------add_safepoint----------------------------------
2241 void Parse::add_safepoint() {
2242   uint parms = TypeFunc::Parms+1;
2243 
2244   // Clear out dead values from the debug info.
2245   kill_dead_locals();
2246 
2247   // Clone the JVM State
2248   SafePointNode *sfpnt = new SafePointNode(parms, nullptr);
2249 
2250   // Capture memory state BEFORE a SafePoint.  Since we can block at a
2251   // SafePoint we need our GC state to be safe; i.e. we need all our current
2252   // write barriers (card marks) to not float down after the SafePoint so we
2253   // must read raw memory.  Likewise we need all oop stores to match the card
2254   // marks.  If deopt can happen, we need ALL stores (we need the correct JVM
2255   // state on a deopt).
2256 
2257   // We do not need to WRITE the memory state after a SafePoint.  The control
2258   // edge will keep card-marks and oop-stores from floating up from below a
2259   // SafePoint and our true dependency added here will keep them from floating
2260   // down below a SafePoint.
2261 
2262   // Clone the current memory state
2263   Node* mem = MergeMemNode::make(map()->memory());
2264 
2265   mem = _gvn.transform(mem);
2266 
2267   // Pass control through the safepoint
2268   sfpnt->init_req(TypeFunc::Control  , control());
2269   // Fix edges normally used by a call
2270   sfpnt->init_req(TypeFunc::I_O      , top() );
2271   sfpnt->init_req(TypeFunc::Memory   , mem   );
2272   sfpnt->init_req(TypeFunc::ReturnAdr, top() );
2273   sfpnt->init_req(TypeFunc::FramePtr , top() );
2274 
2275   // Create a node for the polling address
2276   Node *polladr;
2277   Node *thread = _gvn.transform(new ThreadLocalNode());
2278   Node *polling_page_load_addr = _gvn.transform(basic_plus_adr(top(), thread, in_bytes(JavaThread::polling_page_offset())));
2279   polladr = make_load(control(), polling_page_load_addr, TypeRawPtr::BOTTOM, T_ADDRESS, MemNode::unordered);
2280   sfpnt->init_req(TypeFunc::Parms+0, _gvn.transform(polladr));
2281 
2282   // Fix up the JVM State edges
2283   add_safepoint_edges(sfpnt);
2284   Node *transformed_sfpnt = _gvn.transform(sfpnt);
2285   set_control(transformed_sfpnt);
2286 
2287   // Provide an edge from root to safepoint.  This makes the safepoint
2288   // appear useful until the parse has completed.
2289   if (transformed_sfpnt->is_SafePoint()) {
2290     assert(C->root() != nullptr, "Expect parse is still valid");
2291     C->root()->add_prec(transformed_sfpnt);
2292   }
2293 }
2294 
2295 #ifndef PRODUCT
2296 //------------------------show_parse_info--------------------------------------
2297 void Parse::show_parse_info() {
2298   InlineTree* ilt = nullptr;
2299   if (C->ilt() != nullptr) {
2300     JVMState* caller_jvms = is_osr_parse() ? caller()->caller() : caller();
2301     ilt = InlineTree::find_subtree_from_root(C->ilt(), caller_jvms, method());
2302   }
2303   if (PrintCompilation && Verbose) {
2304     if (depth() == 1) {
2305       if( ilt->count_inlines() ) {
2306         tty->print("    __inlined %d (%d bytes)", ilt->count_inlines(),
2307                      ilt->count_inline_bcs());
2308         tty->cr();
2309       }
2310     } else {
2311       if (method()->is_synchronized())         tty->print("s");
2312       if (method()->has_exception_handlers())  tty->print("!");
2313       // Check this is not the final compiled version
2314       if (C->trap_can_recompile()) {
2315         tty->print("-");
2316       } else {
2317         tty->print(" ");
2318       }
2319       method()->print_short_name();
2320       if (is_osr_parse()) {
2321         tty->print(" @ %d", osr_bci());
2322       }
2323       tty->print(" (%d bytes)",method()->code_size());
2324       if (ilt->count_inlines()) {
2325         tty->print(" __inlined %d (%d bytes)", ilt->count_inlines(),
2326                    ilt->count_inline_bcs());
2327       }
2328       tty->cr();
2329     }
2330   }
2331   if (PrintOpto && (depth() == 1 || PrintOptoInlining)) {
2332     // Print that we succeeded; suppress this message on the first osr parse.
2333 
2334     if (method()->is_synchronized())         tty->print("s");
2335     if (method()->has_exception_handlers())  tty->print("!");
2336     // Check this is not the final compiled version
2337     if (C->trap_can_recompile() && depth() == 1) {
2338       tty->print("-");
2339     } else {
2340       tty->print(" ");
2341     }
2342     if( depth() != 1 ) { tty->print("   "); }  // missing compile count
2343     for (int i = 1; i < depth(); ++i) { tty->print("  "); }
2344     method()->print_short_name();
2345     if (is_osr_parse()) {
2346       tty->print(" @ %d", osr_bci());
2347     }
2348     if (ilt->caller_bci() != -1) {
2349       tty->print(" @ %d", ilt->caller_bci());
2350     }
2351     tty->print(" (%d bytes)",method()->code_size());
2352     if (ilt->count_inlines()) {
2353       tty->print(" __inlined %d (%d bytes)", ilt->count_inlines(),
2354                  ilt->count_inline_bcs());
2355     }
2356     tty->cr();
2357   }
2358 }
2359 
2360 
2361 //------------------------------dump-------------------------------------------
2362 // Dump information associated with the bytecodes of current _method
2363 void Parse::dump() {
2364   if( method() != nullptr ) {
2365     // Iterate over bytecodes
2366     ciBytecodeStream iter(method());
2367     for( Bytecodes::Code bc = iter.next(); bc != ciBytecodeStream::EOBC() ; bc = iter.next() ) {
2368       dump_bci( iter.cur_bci() );
2369       tty->cr();
2370     }
2371   }
2372 }
2373 
2374 // Dump information associated with a byte code index, 'bci'
2375 void Parse::dump_bci(int bci) {
2376   // Output info on merge-points, cloning, and within _jsr..._ret
2377   // NYI
2378   tty->print(" bci:%d", bci);
2379 }
2380 
2381 #endif