1 /*
   2  * Copyright (c) 1997, 2026, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "ci/ciObjArrayKlass.hpp"
  26 #include "ci/ciSignature.hpp"
  27 #include "ci/ciTypeFlow.hpp"
  28 #include "compiler/compileLog.hpp"
  29 #include "interpreter/linkResolver.hpp"
  30 #include "memory/resourceArea.hpp"
  31 #include "oops/method.hpp"
  32 #include "opto/addnode.hpp"
  33 #include "opto/c2compiler.hpp"
  34 #include "opto/castnode.hpp"
  35 #include "opto/convertnode.hpp"
  36 #include "opto/idealGraphPrinter.hpp"
  37 #include "opto/inlinetypenode.hpp"
  38 #include "opto/locknode.hpp"
  39 #include "opto/memnode.hpp"
  40 #include "opto/opaquenode.hpp"
  41 #include "opto/parse.hpp"
  42 #include "opto/rootnode.hpp"
  43 #include "opto/runtime.hpp"
  44 #include "opto/type.hpp"
  45 #include "runtime/arguments.hpp"
  46 #include "runtime/handles.inline.hpp"
  47 #include "runtime/safepointMechanism.hpp"
  48 #include "runtime/sharedRuntime.hpp"
  49 #include "utilities/bitMap.inline.hpp"
  50 #include "utilities/copy.hpp"
  51 
  52 // Static array so we can figure out which bytecodes stop us from compiling
  53 // the most. Some of the non-static variables are needed in bytecodeInfo.cpp
  54 // and eventually should be encapsulated in a proper class (gri 8/18/98).
  55 
  56 #ifndef PRODUCT
  57 uint nodes_created             = 0;
  58 uint methods_parsed            = 0;
  59 uint methods_seen              = 0;
  60 uint blocks_parsed             = 0;
  61 uint blocks_seen               = 0;
  62 
  63 uint explicit_null_checks_inserted = 0;
  64 uint explicit_null_checks_elided   = 0;
  65 uint all_null_checks_found         = 0;
  66 uint implicit_null_checks          = 0;
  67 
  68 bool Parse::BytecodeParseHistogram::_initialized = false;
  69 uint Parse::BytecodeParseHistogram::_bytecodes_parsed [Bytecodes::number_of_codes];
  70 uint Parse::BytecodeParseHistogram::_nodes_constructed[Bytecodes::number_of_codes];
  71 uint Parse::BytecodeParseHistogram::_nodes_transformed[Bytecodes::number_of_codes];
  72 uint Parse::BytecodeParseHistogram::_new_values       [Bytecodes::number_of_codes];
  73 
  74 //------------------------------print_statistics-------------------------------
  75 void Parse::print_statistics() {
  76   tty->print_cr("--- Compiler Statistics ---");
  77   tty->print("Methods seen: %u  Methods parsed: %u", methods_seen, methods_parsed);
  78   tty->print("  Nodes created: %u", nodes_created);
  79   tty->cr();
  80   if (methods_seen != methods_parsed) {
  81     tty->print_cr("Reasons for parse failures (NOT cumulative):");
  82   }
  83   tty->print_cr("Blocks parsed: %u  Blocks seen: %u", blocks_parsed, blocks_seen);
  84 
  85   if (explicit_null_checks_inserted) {
  86     tty->print_cr("%u original null checks - %u elided (%2u%%); optimizer leaves %u,",
  87                   explicit_null_checks_inserted, explicit_null_checks_elided,
  88                   (100*explicit_null_checks_elided)/explicit_null_checks_inserted,
  89                   all_null_checks_found);
  90   }
  91   if (all_null_checks_found) {
  92     tty->print_cr("%u made implicit (%2u%%)", implicit_null_checks,
  93                   (100*implicit_null_checks)/all_null_checks_found);
  94   }
  95   if (SharedRuntime::_implicit_null_throws) {
  96     tty->print_cr("%u implicit null exceptions at runtime",
  97                   SharedRuntime::_implicit_null_throws);
  98   }
  99 
 100   if (PrintParseStatistics && BytecodeParseHistogram::initialized()) {
 101     BytecodeParseHistogram::print();
 102   }
 103 }
 104 #endif
 105 
 106 //------------------------------ON STACK REPLACEMENT---------------------------
 107 
 108 // Construct a node which can be used to get incoming state for
 109 // on stack replacement.
 110 Node* Parse::fetch_interpreter_state(int index,
 111                                      const Type* type,
 112                                      Node* local_addrs) {
 113   BasicType bt = type->basic_type();
 114   if (type == TypePtr::NULL_PTR) {
 115     // Ptr types are mixed together with T_ADDRESS but nullptr is
 116     // really for T_OBJECT types so correct it.
 117     bt = T_OBJECT;
 118   }
 119   Node* mem = memory(Compile::AliasIdxRaw);
 120   Node* adr = off_heap_plus_addr(local_addrs, -index*wordSize);
 121   Node* ctl = control();
 122 
 123   // Very similar to LoadNode::make, except we handle un-aligned longs and
 124   // doubles on Sparc.  Intel can handle them just fine directly.
 125   Node *l = nullptr;
 126   switch (bt) {                // Signature is flattened
 127   case T_INT:     l = new LoadINode(ctl, mem, adr, TypeRawPtr::BOTTOM, TypeInt::INT,        MemNode::unordered); break;
 128   case T_FLOAT:   l = new LoadFNode(ctl, mem, adr, TypeRawPtr::BOTTOM, Type::FLOAT,         MemNode::unordered); break;
 129   case T_ADDRESS: l = new LoadPNode(ctl, mem, adr, TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM,  MemNode::unordered); break;
 130   case T_OBJECT:  l = new LoadPNode(ctl, mem, adr, TypeRawPtr::BOTTOM, TypeInstPtr::BOTTOM, MemNode::unordered); break;
 131   case T_LONG:
 132   case T_DOUBLE: {
 133     // Since arguments are in reverse order, the argument address 'adr'
 134     // refers to the back half of the long/double.  Recompute adr.
 135     adr = off_heap_plus_addr(local_addrs, -(index+1)*wordSize);
 136     if (Matcher::misaligned_doubles_ok) {
 137       l = (bt == T_DOUBLE)
 138         ? (Node*)new LoadDNode(ctl, mem, adr, TypeRawPtr::BOTTOM, Type::DOUBLE, MemNode::unordered)
 139         : (Node*)new LoadLNode(ctl, mem, adr, TypeRawPtr::BOTTOM, TypeLong::LONG, MemNode::unordered);
 140     } else {
 141       l = (bt == T_DOUBLE)
 142         ? (Node*)new LoadD_unalignedNode(ctl, mem, adr, TypeRawPtr::BOTTOM, MemNode::unordered)
 143         : (Node*)new LoadL_unalignedNode(ctl, mem, adr, TypeRawPtr::BOTTOM, MemNode::unordered);
 144     }
 145     break;
 146   }
 147   default: ShouldNotReachHere();
 148   }
 149   return _gvn.transform(l);
 150 }
 151 
 152 // Helper routine to prevent the interpreter from handing
 153 // unexpected typestate to an OSR method.
 154 // The Node l is a value newly dug out of the interpreter frame.
 155 // The type is the type predicted by ciTypeFlow.  Note that it is
 156 // not a general type, but can only come from Type::get_typeflow_type.
 157 // The safepoint is a map which will feed an uncommon trap.
 158 Node* Parse::check_interpreter_type(Node* l, ciType* ci_type, SafePointNode* &bad_type_exit) {
 159   ciType* unwrapped_ci_type = ci_type->unwrap();
 160 
 161   // TypeFlow may assert null-ness if a type appears unloaded.
 162   if (int(unwrapped_ci_type->basic_type()) == int(ciTypeFlow::StateVector::T_NULL) ||
 163       !unwrapped_ci_type->is_loaded()) {
 164     // Value must be null, not a real oop.
 165     Node* chk = _gvn.transform(new CmpPNode(l, null()));
 166     Node* tst = _gvn.transform(new BoolNode(chk, BoolTest::eq));
 167     IfNode* iff = create_and_map_if(control(), tst, PROB_MAX, COUNT_UNKNOWN);
 168     set_control(_gvn.transform(new IfTrueNode(iff)));
 169     Node* bad_type = _gvn.transform(new IfFalseNode(iff));
 170     bad_type_exit->control()->add_req(bad_type);
 171     l = null();
 172   }
 173 
 174   // Typeflow can also cut off paths from the CFG, based on
 175   // types which appear unloaded, or call sites which appear unlinked.
 176   // When paths are cut off, values at later merge points can rise
 177   // toward more specific classes.  Make sure these specific classes
 178   // are still in effect.
 179   if (unwrapped_ci_type->is_klass()) {
 180     // TypeFlow asserted a specific object type. Value must have that type.
 181     assert(_gvn.type(l) == TypePtr::NULL_PTR || _gvn.type(l)->isa_oopptr(), "must be an oop");
 182     if (ci_type->is_null_free()) {
 183       // Check inline types for null here to prevent checkcast from adding an
 184       // exception state before the bytecode entry (use 'bad_type_ctrl' instead).
 185       Node* bad_type_ctrl = nullptr;
 186       l = null_check_oop(l, &bad_type_ctrl);
 187       bad_type_exit->control()->add_req(bad_type_ctrl);
 188     }
 189 
 190     const TypeKlassPtr* klass_type = TypeKlassPtr::make(unwrapped_ci_type->as_klass(), Type::ignore_interfaces);
 191     klass_type = klass_type->try_improve();
 192     bool is_early_larval = ci_type->is_early_larval();
 193     Node* bad_type_ctrl = nullptr;
 194     l = gen_checkcast(l, makecon(klass_type), &bad_type_ctrl, nullptr, false, is_early_larval);
 195     bad_type_exit->control()->add_req(bad_type_ctrl);
 196   } else {
 197     const Type* type = Type::get_typeflow_type(ci_type);
 198     assert(_gvn.type(l)->higher_equal(type), "must match");
 199   }
 200 
 201   return l;
 202 }
 203 
 204 // Helper routine which sets up elements of the initial parser map when
 205 // performing a parse for on stack replacement.  Add values into map.
 206 // The only parameter contains the address of a interpreter arguments.
 207 void Parse::load_interpreter_state(Node* osr_buf) {
 208   int index;
 209   int max_locals = jvms()->loc_size();
 210   int max_stack  = jvms()->stk_size();
 211 
 212   // Mismatch between method and jvms can occur since map briefly held
 213   // an OSR entry state (which takes up one RawPtr word).
 214   assert(max_locals == method()->max_locals(), "sanity");
 215   assert(max_stack  >= method()->max_stack(),  "sanity");
 216   assert((int)jvms()->endoff() == TypeFunc::Parms + max_locals + max_stack, "sanity");
 217   assert((int)jvms()->endoff() == (int)map()->req(), "sanity");
 218 
 219   // Find the start block.
 220   Block* osr_block = start_block();
 221   assert(osr_block->start() == osr_bci(), "sanity");
 222 
 223   // Set initial BCI.
 224   set_parse_bci(osr_block->start());
 225 
 226   // Set initial stack depth.
 227   set_sp(osr_block->start_sp());
 228 
 229   // Check bailouts.  We currently do not perform on stack replacement
 230   // of loops in catch blocks or loops which branch with a non-empty stack.
 231   if (sp() != 0) {
 232     C->record_method_not_compilable("OSR starts with non-empty stack");
 233     return;
 234   }
 235   // Do not OSR inside finally clauses:
 236   if (osr_block->has_trap_at(osr_block->start())) {
 237     assert(false, "OSR starts with an immediate trap");
 238     C->record_method_not_compilable("OSR starts with an immediate trap");
 239     return;
 240   }
 241 
 242   // Commute monitors from interpreter frame to compiler frame.
 243   assert(jvms()->monitor_depth() == 0, "should be no active locks at beginning of osr");
 244   int mcnt = osr_block->flow()->monitor_count();
 245   Node* monitors_addr = off_heap_plus_addr(osr_buf, (max_locals+mcnt*2-1)*wordSize);
 246   for (index = 0; index < mcnt; index++) {
 247     // Make a BoxLockNode for the monitor.
 248     BoxLockNode* osr_box = new BoxLockNode(next_monitor());
 249     // Check for bailout after new BoxLockNode
 250     if (failing()) { return; }
 251 
 252     // This OSR locking region is unbalanced because it does not have Lock node:
 253     // locking was done in Interpreter.
 254     // This is similar to Coarsened case when Lock node is eliminated
 255     // and as result the region is marked as Unbalanced.
 256 
 257     // Emulate Coarsened state transition from Regular to Unbalanced.
 258     osr_box->set_coarsened();
 259     osr_box->set_unbalanced();
 260 
 261     Node* box = _gvn.transform(osr_box);
 262 
 263     // Displaced headers and locked objects are interleaved in the
 264     // temp OSR buffer.  We only copy the locked objects out here.
 265     // Fetch the locked object from the OSR temp buffer and copy to our fastlock node.
 266     Node* lock_object = fetch_interpreter_state(index*2, Type::get_const_basic_type(T_OBJECT), monitors_addr);
 267     // Try and copy the displaced header to the BoxNode
 268     Node* displaced_hdr = fetch_interpreter_state((index*2) + 1, Type::get_const_basic_type(T_ADDRESS), monitors_addr);
 269 
 270     store_to_memory(control(), box, displaced_hdr, T_ADDRESS, MemNode::unordered);
 271 
 272     // Build a bogus FastLockNode (no code will be generated) and push the
 273     // monitor into our debug info.
 274     const FastLockNode *flock = _gvn.transform(new FastLockNode( nullptr, lock_object, box ))->as_FastLock();
 275     map()->push_monitor(flock);
 276 
 277     // If the lock is our method synchronization lock, tuck it away in
 278     // _sync_lock for return and rethrow exit paths.
 279     if (index == 0 && method()->is_synchronized()) {
 280       _synch_lock = flock;
 281     }
 282   }
 283 
 284   // Use the raw liveness computation to make sure that unexpected
 285   // values don't propagate into the OSR frame.
 286   MethodLivenessResult live_locals = method()->liveness_at_bci(osr_bci());
 287   if (!live_locals.is_valid()) {
 288     // Degenerate or breakpointed method.
 289     assert(false, "OSR in empty or breakpointed method");
 290     C->record_method_not_compilable("OSR in empty or breakpointed method");
 291     return;
 292   }
 293 
 294   // Extract the needed locals from the interpreter frame.
 295   Node* locals_addr = off_heap_plus_addr(osr_buf, (max_locals-1)*wordSize);
 296 
 297   // find all the locals that the interpreter thinks contain live oops
 298   const ResourceBitMap live_oops = method()->live_local_oops_at_bci(osr_bci());
 299   for (index = 0; index < max_locals; index++) {
 300 
 301     if (!live_locals.at(index)) {
 302       continue;
 303     }
 304 
 305     const Type *type = osr_block->local_type_at(index);
 306 
 307     if (type->isa_oopptr() != nullptr) {
 308 
 309       // 6403625: Verify that the interpreter oopMap thinks that the oop is live
 310       // else we might load a stale oop if the MethodLiveness disagrees with the
 311       // result of the interpreter. If the interpreter says it is dead we agree
 312       // by making the value go to top.
 313       //
 314 
 315       if (!live_oops.at(index)) {
 316         if (C->log() != nullptr) {
 317           C->log()->elem("OSR_mismatch local_index='%d'",index);
 318         }
 319         set_local(index, null());
 320         // and ignore it for the loads
 321         continue;
 322       }
 323     }
 324 
 325     // Filter out TOP, HALF, and BOTTOM.  (Cf. ensure_phi.)
 326     if (type == Type::TOP || type == Type::HALF) {
 327       continue;
 328     }
 329     // If the type falls to bottom, then this must be a local that
 330     // is mixing ints and oops or some such.  Forcing it to top
 331     // makes it go dead.
 332     if (type == Type::BOTTOM) {
 333       continue;
 334     }
 335     // Construct code to access the appropriate local.
 336     Node* value = fetch_interpreter_state(index, type, locals_addr);
 337     set_local(index, value);
 338   }
 339 
 340   // Extract the needed stack entries from the interpreter frame.
 341   for (index = 0; index < sp(); index++) {
 342     const Type *type = osr_block->stack_type_at(index);
 343     if (type != Type::TOP) {
 344       // Currently the compiler bails out when attempting to on stack replace
 345       // at a bci with a non-empty stack.  We should not reach here.
 346       ShouldNotReachHere();
 347     }
 348   }
 349 
 350   // End the OSR migration
 351   make_runtime_call(RC_LEAF, OptoRuntime::osr_end_Type(),
 352                     CAST_FROM_FN_PTR(address, SharedRuntime::OSR_migration_end),
 353                     "OSR_migration_end", TypeRawPtr::BOTTOM,
 354                     osr_buf);
 355 
 356   // Now that the interpreter state is loaded, make sure it will match
 357   // at execution time what the compiler is expecting now:
 358   SafePointNode* bad_type_exit = clone_map();
 359   bad_type_exit->set_control(new RegionNode(1));
 360 
 361   assert(osr_block->flow()->jsrs()->size() == 0, "should be no jsrs live at osr point");
 362   for (index = 0; index < max_locals; index++) {
 363     if (stopped()) {
 364       break;
 365     }
 366     const Type *type = osr_block->local_type_at(index);
 367     Node* l = local(index);
 368     if (l->is_top()) {
 369       continue;
 370     }
 371 
 372     ciType* ci_type = osr_block->flow()->local_type_at(index);
 373     if (ci_type->unwrap()->is_klass() && !live_oops.at(index)) {
 374       // skip type check for dead oops
 375       continue;
 376     }
 377 
 378     if (ci_type->is_return_address()) {
 379       // In our current system it's illegal for jsr addresses to be
 380       // live into an OSR entry point because the compiler performs
 381       // inlining of jsrs.  ciTypeFlow has a bailout that detect this
 382       // case and aborts the compile if addresses are live into an OSR
 383       // entry point.  Because of that we can assume that any address
 384       // locals at the OSR entry point are dead.  Method liveness
 385       // isn't precise enough to figure out that they are dead in all
 386       // cases so simply skip checking address locals all
 387       // together. Any type check is guaranteed to fail since the
 388       // interpreter type is the result of a load which might have any
 389       // value and the expected type is a constant.
 390       continue;
 391     }
 392     if (StressReachabilityFences && type->isa_oopptr() != nullptr) {
 393       // Keep all oop locals alive until the method returns as if there are
 394       // reachability fences for them at the end of the method.
 395       Node* loc = local(index);
 396       if (loc->bottom_type() != TypePtr::NULL_PTR) {
 397         assert(loc->bottom_type()->isa_oopptr() != nullptr, "%s", Type::str(loc->bottom_type()));
 398         _stress_rf_hook->add_req(loc);
 399       }
 400     }
 401     set_local(index, check_interpreter_type(l, ci_type, bad_type_exit));
 402   }
 403 
 404   for (index = 0; index < sp(); index++) {
 405     if (stopped()) {
 406       break;
 407     }
 408     const Type *type = osr_block->local_type_at(index);
 409     if (StressReachabilityFences && type->isa_oopptr() != nullptr) {
 410       // Keep all oops on stack alive until the method returns as if there are
 411       // reachability fences for them at the end of the method.
 412       Node* stk = stack(index);
 413       if (stk->bottom_type() != TypePtr::NULL_PTR) {
 414         assert(stk->bottom_type()->isa_oopptr() != nullptr, "%s", Type::str(stk->bottom_type()));
 415         _stress_rf_hook->add_req(stk);
 416       }
 417     }
 418 
 419     Node* l = stack(index);
 420     if (l->is_top()) {
 421       continue;
 422     }
 423 
 424     ciType* ci_type = osr_block->flow()->stack_type_at(index);
 425     set_stack(index, check_interpreter_type(l, ci_type, bad_type_exit));
 426   }
 427 
 428   if (bad_type_exit->control()->req() > 1) {
 429     // Build an uncommon trap here, if any inputs can be unexpected.
 430     bad_type_exit->set_control(_gvn.transform( bad_type_exit->control() ));
 431     record_for_igvn(bad_type_exit->control());
 432     SafePointNode* types_are_good = map();
 433     set_map(bad_type_exit);
 434     // The unexpected type happens because a new edge is active
 435     // in the CFG, which typeflow had previously ignored.
 436     // E.g., Object x = coldAtFirst() && notReached()? "str": new Integer(123).
 437     // This x will be typed as Integer if notReached is not yet linked.
 438     // It could also happen due to a problem in ciTypeFlow analysis.
 439     uncommon_trap(Deoptimization::Reason_constraint,
 440                   Deoptimization::Action_reinterpret);
 441     set_map(types_are_good);
 442   }
 443 }
 444 
 445 //------------------------------Parse------------------------------------------
 446 // Main parser constructor.
 447 Parse::Parse(JVMState* caller, ciMethod* parse_method, float expected_uses)
 448   : _exits(caller)
 449 {
 450   // Init some variables
 451   _caller = caller;
 452   _method = parse_method;
 453   _expected_uses = expected_uses;
 454   _depth = 1 + (caller->has_method() ? caller->depth() : 0);
 455   _wrote_non_strict_final = false;
 456   _wrote_volatile = false;
 457   _wrote_stable = false;
 458   _wrote_fields = false;
 459   _alloc_with_final_or_stable = nullptr;
 460   _stress_rf_hook = (StressReachabilityFences ? new Node(1) : nullptr);
 461   _block = nullptr;
 462   _first_return = true;
 463   _replaced_nodes_for_exceptions = false;
 464   _new_idx = C->unique();
 465   DEBUG_ONLY(_entry_bci = UnknownBci);
 466   DEBUG_ONLY(_block_count = -1);
 467   DEBUG_ONLY(_blocks = (Block*)-1);
 468 #ifndef PRODUCT
 469   if (PrintCompilation || PrintOpto) {
 470     // Make sure I have an inline tree, so I can print messages about it.
 471     InlineTree::find_subtree_from_root(C->ilt(), caller, parse_method);
 472   }
 473   _max_switch_depth = 0;
 474   _est_switch_depth = 0;
 475 #endif
 476 
 477   if (parse_method->has_reserved_stack_access()) {
 478     C->set_has_reserved_stack_access(true);
 479   }
 480 
 481   if (parse_method->is_synchronized() || parse_method->has_monitor_bytecodes()) {
 482     C->set_has_monitors(true);
 483   }
 484 
 485   if (parse_method->is_scoped()) {
 486     C->set_has_scoped_access(true);
 487   }
 488 
 489   _iter.reset_to_method(method());
 490   C->set_has_loops(C->has_loops() || method()->has_loops());
 491 
 492   if (_expected_uses <= 0) {
 493     _prof_factor = 1;
 494   } else {
 495     float prof_total = parse_method->interpreter_invocation_count();
 496     if (prof_total <= _expected_uses) {
 497       _prof_factor = 1;
 498     } else {
 499       _prof_factor = _expected_uses / prof_total;
 500     }
 501   }
 502 
 503   CompileLog* log = C->log();
 504   if (log != nullptr) {
 505     log->begin_head("parse method='%d' uses='%f'",
 506                     log->identify(parse_method), expected_uses);
 507     if (depth() == 1 && C->is_osr_compilation()) {
 508       log->print(" osr_bci='%d'", C->entry_bci());
 509     }
 510     log->stamp();
 511     log->end_head();
 512   }
 513 
 514   // Accumulate deoptimization counts.
 515   // (The range_check and store_check counts are checked elsewhere.)
 516   ciMethodData* md = method()->method_data();
 517   for (uint reason = 0; reason < md->trap_reason_limit(); reason++) {
 518     uint md_count = md->trap_count(reason);
 519     if (md_count != 0) {
 520       if (md_count >= md->trap_count_limit()) {
 521         md_count = md->trap_count_limit() + md->overflow_trap_count();
 522       }
 523       uint total_count = C->trap_count(reason);
 524       uint old_count   = total_count;
 525       total_count += md_count;
 526       // Saturate the add if it overflows.
 527       if (total_count < old_count || total_count < md_count)
 528         total_count = (uint)-1;
 529       C->set_trap_count(reason, total_count);
 530       if (log != nullptr)
 531         log->elem("observe trap='%s' count='%d' total='%d'",
 532                   Deoptimization::trap_reason_name(reason),
 533                   md_count, total_count);
 534     }
 535   }
 536   // Accumulate total sum of decompilations, also.
 537   C->set_decompile_count(C->decompile_count() + md->decompile_count());
 538 
 539   if (log != nullptr && method()->has_exception_handlers()) {
 540     log->elem("observe that='has_exception_handlers'");
 541   }
 542 
 543   assert(InlineTree::check_can_parse(method()) == nullptr, "Can not parse this method, cutout earlier");
 544   assert(method()->has_balanced_monitors(), "Can not parse unbalanced monitors, cutout earlier");
 545 
 546   // Always register dependence if JVMTI is enabled, because
 547   // either breakpoint setting or hotswapping of methods may
 548   // cause deoptimization.
 549   if (C->env()->jvmti_can_hotswap_or_post_breakpoint()) {
 550     C->dependencies()->assert_evol_method(method());
 551   }
 552 
 553   NOT_PRODUCT(methods_seen++);
 554 
 555   // Do some special top-level things.
 556   if (depth() == 1 && C->is_osr_compilation()) {
 557     _tf = C->tf();     // the OSR entry type is different
 558     _entry_bci = C->entry_bci();
 559     _flow = method()->get_osr_flow_analysis(osr_bci());
 560   } else {
 561     _tf = TypeFunc::make(method(), false);
 562     _entry_bci = InvocationEntryBci;
 563     _flow = method()->get_flow_analysis();
 564   }
 565 
 566   if (_flow->failing()) {
 567     assert(false, "type flow analysis failed during parsing");
 568     C->record_method_not_compilable(_flow->failure_reason());
 569 #ifndef PRODUCT
 570       if (PrintOpto && (Verbose || WizardMode)) {
 571         if (is_osr_parse()) {
 572           tty->print_cr("OSR @%d type flow bailout: %s", _entry_bci, _flow->failure_reason());
 573         } else {
 574           tty->print_cr("type flow bailout: %s", _flow->failure_reason());
 575         }
 576         if (Verbose) {
 577           method()->print();
 578           method()->print_codes();
 579           _flow->print();
 580         }
 581       }
 582 #endif
 583   }
 584 
 585 #ifdef ASSERT
 586   if (depth() == 1) {
 587     assert(C->is_osr_compilation() == this->is_osr_parse(), "OSR in sync");
 588   } else {
 589     assert(!this->is_osr_parse(), "no recursive OSR");
 590   }
 591 #endif
 592 
 593 #ifndef PRODUCT
 594   if (_flow->has_irreducible_entry()) {
 595     C->set_parsed_irreducible_loop(true);
 596   }
 597 
 598   methods_parsed++;
 599   // add method size here to guarantee that inlined methods are added too
 600   if (CITime)
 601     _total_bytes_compiled += method()->code_size();
 602 
 603   show_parse_info();
 604 #endif
 605 
 606   if (failing()) {
 607     if (log)  log->done("parse");
 608     return;
 609   }
 610 
 611   gvn().transform(top());
 612 
 613   // Import the results of the ciTypeFlow.
 614   init_blocks();
 615 
 616   // Merge point for all normal exits
 617   build_exits();
 618 
 619   // Setup the initial JVM state map.
 620   SafePointNode* entry_map = create_entry_map();
 621 
 622   // Check for bailouts during map initialization
 623   if (failing() || entry_map == nullptr) {
 624     if (log)  log->done("parse");
 625     return;
 626   }
 627 
 628   Node_Notes* caller_nn = C->default_node_notes();
 629   // Collect debug info for inlined calls unless -XX:-DebugInlinedCalls.
 630   if (DebugInlinedCalls || depth() == 1) {
 631     C->set_default_node_notes(make_node_notes(caller_nn));
 632   }
 633 
 634   if (is_osr_parse()) {
 635     Node* osr_buf = entry_map->in(TypeFunc::Parms+0);
 636     entry_map->set_req(TypeFunc::Parms+0, top());
 637     set_map(entry_map);
 638     load_interpreter_state(osr_buf);
 639   } else {
 640     set_map(entry_map);
 641     do_method_entry();
 642   }
 643 
 644   if (depth() == 1 && !failing()) {
 645     if (C->clinit_barrier_on_entry()) {
 646       // Add check to deoptimize the nmethod once the holder class is fully initialized
 647       clinit_deopt();
 648     }
 649   }
 650 
 651   // Check for bailouts during method entry.
 652   if (failing()) {
 653     if (log)  log->done("parse");
 654     C->set_default_node_notes(caller_nn);
 655     return;
 656   }
 657 
 658   entry_map = map();  // capture any changes performed by method setup code
 659   assert(jvms()->endoff() == map()->req(), "map matches JVMS layout");
 660 
 661   // We begin parsing as if we have just encountered a jump to the
 662   // method entry.
 663   Block* entry_block = start_block();
 664   assert(entry_block->start() == (is_osr_parse() ? osr_bci() : 0), "");
 665   set_map_clone(entry_map);
 666   merge_common(entry_block, entry_block->next_path_num());
 667 
 668 #ifndef PRODUCT
 669   BytecodeParseHistogram *parse_histogram_obj = new (C->env()->arena()) BytecodeParseHistogram(this, C);
 670   set_parse_histogram( parse_histogram_obj );
 671 #endif
 672 
 673   // Parse all the basic blocks.
 674   do_all_blocks();
 675 
 676   // Check for bailouts during conversion to graph
 677   if (failing()) {
 678     if (log)  log->done("parse");
 679     return;
 680   }
 681 
 682   // Fix up all exiting control flow.
 683   set_map(entry_map);
 684   do_exits();
 685 
 686   // Only reset this now, to make sure that debug information emitted
 687   // for exiting control flow still refers to the inlined method.
 688   C->set_default_node_notes(caller_nn);
 689 
 690   if (log)  log->done("parse nodes='%d' live='%d' memory='%zu'",
 691                       C->unique(), C->live_nodes(), C->node_arena()->used());
 692 
 693   if (StressReachabilityFences) {
 694     _stress_rf_hook->destruct(&_gvn);
 695     _stress_rf_hook = nullptr;
 696   }
 697 }
 698 
 699 //---------------------------do_all_blocks-------------------------------------
 700 void Parse::do_all_blocks() {
 701   bool has_irreducible = flow()->has_irreducible_entry();
 702 
 703   // Walk over all blocks in Reverse Post-Order.
 704   while (true) {
 705     bool progress = false;
 706     for (int rpo = 0; rpo < block_count(); rpo++) {
 707       Block* block = rpo_at(rpo);
 708 
 709       if (block->is_parsed()) continue;
 710 
 711       if (!block->is_merged()) {
 712         // Dead block, no state reaches this block
 713         continue;
 714       }
 715 
 716       // Prepare to parse this block.
 717       load_state_from(block);
 718 
 719       if (stopped()) {
 720         // Block is dead.
 721         continue;
 722       }
 723 
 724       NOT_PRODUCT(blocks_parsed++);
 725 
 726       progress = true;
 727       if (block->is_loop_head() || block->is_handler() || (has_irreducible && !block->is_ready())) {
 728         // Not all preds have been parsed.  We must build phis everywhere.
 729         // (Note that dead locals do not get phis built, ever.)
 730         ensure_phis_everywhere();
 731 
 732         if (block->is_SEL_head()) {
 733           // Add predicate to single entry (not irreducible) loop head.
 734           assert(!block->has_merged_backedge(), "only entry paths should be merged for now");
 735           // Predicates may have been added after a dominating if
 736           if (!block->has_predicates()) {
 737             // Need correct bci for predicate.
 738             // It is fine to set it here since do_one_block() will set it anyway.
 739             set_parse_bci(block->start());
 740             add_parse_predicates();
 741           }
 742           // Add new region for back branches.
 743           int edges = block->pred_count() - block->preds_parsed() + 1; // +1 for original region
 744           RegionNode *r = new RegionNode(edges+1);
 745           _gvn.set_type(r, Type::CONTROL);
 746           record_for_igvn(r);
 747           r->init_req(edges, control());
 748           set_control(r);
 749           block->copy_irreducible_status_to(r, jvms());
 750           // Add new phis.
 751           ensure_phis_everywhere();
 752         }
 753 
 754         // Leave behind an undisturbed copy of the map, for future merges.
 755         set_map(clone_map());
 756       }
 757 
 758       if (control()->is_Region() && !block->is_loop_head() && !has_irreducible && !block->is_handler()) {
 759         // In the absence of irreducible loops, the Region and Phis
 760         // associated with a merge that doesn't involve a backedge can
 761         // be simplified now since the RPO parsing order guarantees
 762         // that any path which was supposed to reach here has already
 763         // been parsed or must be dead.
 764         Node* c = control();
 765         Node* result = _gvn.transform(control());
 766         if (c != result && TraceOptoParse) {
 767           tty->print_cr("Block #%d replace %d with %d", block->rpo(), c->_idx, result->_idx);
 768         }
 769         if (result != top()) {
 770           record_for_igvn(result);
 771         }
 772       }
 773 
 774       // Parse the block.
 775       do_one_block();
 776 
 777       // Check for bailouts.
 778       if (failing())  return;
 779     }
 780 
 781     // with irreducible loops multiple passes might be necessary to parse everything
 782     if (!has_irreducible || !progress) {
 783       break;
 784     }
 785   }
 786 
 787 #ifndef PRODUCT
 788   blocks_seen += block_count();
 789 
 790   // Make sure there are no half-processed blocks remaining.
 791   // Every remaining unprocessed block is dead and may be ignored now.
 792   for (int rpo = 0; rpo < block_count(); rpo++) {
 793     Block* block = rpo_at(rpo);
 794     if (!block->is_parsed()) {
 795       if (TraceOptoParse) {
 796         tty->print_cr("Skipped dead block %d at bci:%d", rpo, block->start());
 797       }
 798       assert(!block->is_merged(), "no half-processed blocks");
 799     }
 800   }
 801 #endif
 802 }
 803 
 804 static Node* mask_int_value(Node* v, BasicType bt, PhaseGVN* gvn) {
 805   switch (bt) {
 806   case T_BYTE:
 807     v = gvn->transform(new LShiftINode(v, gvn->intcon(24)));
 808     v = gvn->transform(new RShiftINode(v, gvn->intcon(24)));
 809     break;
 810   case T_SHORT:
 811     v = gvn->transform(new LShiftINode(v, gvn->intcon(16)));
 812     v = gvn->transform(new RShiftINode(v, gvn->intcon(16)));
 813     break;
 814   case T_CHAR:
 815     v = gvn->transform(new AndINode(v, gvn->intcon(0xFFFF)));
 816     break;
 817   case T_BOOLEAN:
 818     v = gvn->transform(new AndINode(v, gvn->intcon(0x1)));
 819     break;
 820   default:
 821     break;
 822   }
 823   return v;
 824 }
 825 
 826 //-------------------------------build_exits----------------------------------
 827 // Build normal and exceptional exit merge points.
 828 void Parse::build_exits() {
 829   // make a clone of caller to prevent sharing of side-effects
 830   _exits.set_map(_exits.clone_map());
 831   _exits.clean_stack(_exits.sp());
 832   _exits.sync_jvms();
 833 
 834   RegionNode* region = new RegionNode(1);
 835   record_for_igvn(region);
 836   gvn().set_type_bottom(region);
 837   _exits.set_control(region);
 838 
 839   // Note:  iophi and memphi are not transformed until do_exits.
 840   Node* iophi  = new PhiNode(region, Type::ABIO);
 841   Node* memphi = new PhiNode(region, Type::MEMORY, TypePtr::BOTTOM);
 842   gvn().set_type_bottom(iophi);
 843   gvn().set_type_bottom(memphi);
 844   _exits.set_i_o(iophi);
 845   _exits.set_all_memory(memphi);
 846 
 847   // Add a return value to the exit state.  (Do not push it yet.)
 848   if (tf()->range_sig()->cnt() > TypeFunc::Parms) {
 849     const Type* ret_type = tf()->range_sig()->field_at(TypeFunc::Parms);
 850     if (ret_type->isa_int()) {
 851       BasicType ret_bt = method()->return_type()->basic_type();
 852       if (ret_bt == T_BOOLEAN ||
 853           ret_bt == T_CHAR ||
 854           ret_bt == T_BYTE ||
 855           ret_bt == T_SHORT) {
 856         ret_type = TypeInt::INT;
 857       }
 858     }
 859 
 860     // Don't "bind" an unloaded return klass to the ret_phi. If the klass
 861     // becomes loaded during the subsequent parsing, the loaded and unloaded
 862     // types will not join when we transform and push in do_exits().
 863     const TypeOopPtr* ret_oop_type = ret_type->isa_oopptr();
 864     if (ret_oop_type && !ret_oop_type->is_loaded()) {
 865       ret_type = TypeOopPtr::BOTTOM;
 866     }
 867     int         ret_size = type2size[ret_type->basic_type()];
 868     Node*       ret_phi  = new PhiNode(region, ret_type);
 869     gvn().set_type_bottom(ret_phi);
 870     _exits.ensure_stack(ret_size);
 871     assert((int)(tf()->range_sig()->cnt() - TypeFunc::Parms) == ret_size, "good tf range");
 872     assert(method()->return_type()->size() == ret_size, "tf agrees w/ method");
 873     _exits.set_argument(0, ret_phi);  // here is where the parser finds it
 874     // Note:  ret_phi is not yet pushed, until do_exits.
 875   }
 876 }
 877 
 878 //----------------------------build_start_state-------------------------------
 879 // Construct a state which contains only the incoming arguments from an
 880 // unknown caller.  The method & bci will be null & InvocationEntryBci.
 881 JVMState* Compile::build_start_state(StartNode* start, const TypeFunc* tf) {
 882   int        arg_size = tf->domain_sig()->cnt();
 883   int        max_size = MAX2(arg_size, (int)tf->range_cc()->cnt());
 884   JVMState*  jvms     = new (this) JVMState(max_size - TypeFunc::Parms);
 885   SafePointNode* map  = new SafePointNode(max_size, jvms);
 886   jvms->set_map(map);
 887   record_for_igvn(map);
 888   assert(arg_size == TypeFunc::Parms + (is_osr_compilation() ? 1 : method()->arg_size()), "correct arg_size");
 889   Node_Notes* old_nn = default_node_notes();
 890   if (old_nn != nullptr && has_method()) {
 891     Node_Notes* entry_nn = old_nn->clone(this);
 892     JVMState* entry_jvms = new(this) JVMState(method(), old_nn->jvms());
 893     entry_jvms->set_offsets(0);
 894     entry_jvms->set_bci(entry_bci());
 895     entry_nn->set_jvms(entry_jvms);
 896     set_default_node_notes(entry_nn);
 897   }
 898   PhaseGVN& gvn = *initial_gvn();
 899   uint i = 0;
 900   int arg_num = 0;
 901   for (uint j = 0; i < (uint)arg_size; i++) {
 902     const Type* t = tf->domain_sig()->field_at(i);
 903     Node* parm = nullptr;
 904     if (t->is_inlinetypeptr() && method()->is_scalarized_arg(arg_num)) {
 905       // Inline type arguments are not passed by reference: we get an argument per
 906       // field of the inline type. Build InlineTypeNodes from the inline type arguments.
 907       GraphKit kit(jvms, &gvn);
 908       kit.set_control(map->control());
 909       Node* old_mem = map->memory();
 910       // Use immutable memory for inline type loads and restore it below
 911       kit.set_all_memory(C->immutable_memory());
 912       parm = InlineTypeNode::make_from_multi(&kit, start, t->inline_klass(), j, /* in= */ true, /* null_free= */ !t->maybe_null());
 913       assert(map == kit.map(), "broken if map changes");
 914       map->set_control(kit.control());
 915       map->set_memory(old_mem);
 916     } else {
 917       parm = gvn.transform(new ParmNode(start, j++));
 918     }
 919     map->init_req(i, parm);
 920     // Record all these guys for later GVN.
 921     record_for_igvn(parm);
 922     if (i >= TypeFunc::Parms && t != Type::HALF) {
 923       arg_num++;
 924     }
 925   }
 926   for (; i < map->req(); i++) {
 927     map->init_req(i, top());
 928   }
 929   assert(jvms->argoff() == TypeFunc::Parms, "parser gets arguments here");
 930   set_default_node_notes(old_nn);
 931   return jvms;
 932 }
 933 
 934 //-----------------------------make_node_notes---------------------------------
 935 Node_Notes* Parse::make_node_notes(Node_Notes* caller_nn) {
 936   if (caller_nn == nullptr)  return nullptr;
 937   Node_Notes* nn = caller_nn->clone(C);
 938   JVMState* caller_jvms = nn->jvms();
 939   JVMState* jvms = new (C) JVMState(method(), caller_jvms);
 940   jvms->set_offsets(0);
 941   jvms->set_bci(_entry_bci);
 942   nn->set_jvms(jvms);
 943   return nn;
 944 }
 945 
 946 
 947 //--------------------------return_values--------------------------------------
 948 void Compile::return_values(JVMState* jvms) {
 949   GraphKit kit(jvms);
 950   Node* ret = new ReturnNode(TypeFunc::Parms,
 951                              kit.control(),
 952                              kit.i_o(),
 953                              kit.reset_memory(),
 954                              kit.frameptr(),
 955                              kit.returnadr());
 956   // Add zero or 1 return values
 957   int ret_size = tf()->range_sig()->cnt() - TypeFunc::Parms;
 958   if (ret_size > 0) {
 959     kit.inc_sp(-ret_size);  // pop the return value(s)
 960     kit.sync_jvms();
 961     Node* res = kit.argument(0);
 962     if (tf()->returns_inline_type_as_fields()) {
 963       // Multiple return values (inline type fields): add as many edges
 964       // to the Return node as returned values.
 965       InlineTypeNode* vt = res->as_InlineType();
 966       ret->add_req_batch(nullptr, tf()->range_cc()->cnt() - TypeFunc::Parms);
 967       if (vt->is_allocated(&kit.gvn()) && !StressCallingConvention) {
 968         ret->init_req(TypeFunc::Parms, vt);
 969       } else {
 970         // Return the tagged klass pointer to signal scalarization to the caller
 971         Node* tagged_klass = vt->tagged_klass(kit.gvn());
 972         // Return null if the inline type is null (null marker field is not set)
 973         Node* conv   = kit.gvn().transform(new ConvI2LNode(vt->get_null_marker()));
 974         Node* shl    = kit.gvn().transform(new LShiftLNode(conv, kit.intcon(63)));
 975         Node* shr    = kit.gvn().transform(new RShiftLNode(shl, kit.intcon(63)));
 976         tagged_klass = kit.gvn().transform(new AndLNode(tagged_klass, shr));
 977         ret->init_req(TypeFunc::Parms, tagged_klass);
 978       }
 979       uint idx = TypeFunc::Parms + 1;
 980       vt->pass_fields(&kit, ret, idx, false, false);
 981     } else {
 982       ret->add_req(res);
 983       // Note:  The second dummy edge is not needed by a ReturnNode.
 984     }
 985   }
 986   // bind it to root
 987   root()->add_req(ret);
 988   record_for_igvn(ret);
 989   initial_gvn()->transform(ret);
 990 }
 991 
 992 //------------------------rethrow_exceptions-----------------------------------
 993 // Bind all exception states in the list into a single RethrowNode.
 994 void Compile::rethrow_exceptions(JVMState* jvms) {
 995   GraphKit kit(jvms);
 996   if (!kit.has_exceptions())  return;  // nothing to generate
 997   // Load my combined exception state into the kit, with all phis transformed:
 998   SafePointNode* ex_map = kit.combine_and_pop_all_exception_states();
 999   Node* ex_oop = kit.use_exception_state(ex_map);
1000   RethrowNode* exit = new RethrowNode(kit.control(),
1001                                       kit.i_o(), kit.reset_memory(),
1002                                       kit.frameptr(), kit.returnadr(),
1003                                       // like a return but with exception input
1004                                       ex_oop);
1005   // bind to root
1006   root()->add_req(exit);
1007   record_for_igvn(exit);
1008   initial_gvn()->transform(exit);
1009 }
1010 
1011 //---------------------------do_exceptions-------------------------------------
1012 // Process exceptions arising from the current bytecode.
1013 // Send caught exceptions to the proper handler within this method.
1014 // Unhandled exceptions feed into _exit.
1015 void Parse::do_exceptions() {
1016   if (!has_exceptions())  return;
1017 
1018   if (failing()) {
1019     // Pop them all off and throw them away.
1020     while (pop_exception_state() != nullptr) ;
1021     return;
1022   }
1023 
1024   PreserveJVMState pjvms(this, false);
1025 
1026   SafePointNode* ex_map;
1027   while ((ex_map = pop_exception_state()) != nullptr) {
1028     if (!method()->has_exception_handlers()) {
1029       // Common case:  Transfer control outward.
1030       // Doing it this early allows the exceptions to common up
1031       // even between adjacent method calls.
1032       throw_to_exit(ex_map);
1033     } else {
1034       // Have to look at the exception first.
1035       assert(stopped(), "catch_inline_exceptions trashes the map");
1036       catch_inline_exceptions(ex_map);
1037       stop_and_kill_map();      // we used up this exception state; kill it
1038     }
1039   }
1040 
1041   // We now return to our regularly scheduled program:
1042 }
1043 
1044 //---------------------------throw_to_exit-------------------------------------
1045 // Merge the given map into an exception exit from this method.
1046 // The exception exit will handle any unlocking of receiver.
1047 // The ex_oop must be saved within the ex_map, unlike merge_exception.
1048 void Parse::throw_to_exit(SafePointNode* ex_map) {
1049   // Pop the JVMS to (a copy of) the caller.
1050   GraphKit caller;
1051   caller.set_map_clone(_caller->map());
1052   caller.set_bci(_caller->bci());
1053   caller.set_sp(_caller->sp());
1054   // Copy out the standard machine state:
1055   for (uint i = 0; i < TypeFunc::Parms; i++) {
1056     caller.map()->set_req(i, ex_map->in(i));
1057   }
1058   if (ex_map->has_replaced_nodes()) {
1059     _replaced_nodes_for_exceptions = true;
1060   }
1061   caller.map()->transfer_replaced_nodes_from(ex_map, _new_idx);
1062   // ...and the exception:
1063   Node*          ex_oop        = saved_ex_oop(ex_map);
1064   SafePointNode* caller_ex_map = caller.make_exception_state(ex_oop);
1065   // Finally, collect the new exception state in my exits:
1066   _exits.add_exception_state(caller_ex_map);
1067 }
1068 
1069 //------------------------------do_exits---------------------------------------
1070 void Parse::do_exits() {
1071   set_parse_bci(InvocationEntryBci);
1072 
1073   // Now peephole on the return bits
1074   Node* region = _exits.control();
1075   _exits.set_control(gvn().transform(region));
1076 
1077   Node* iophi = _exits.i_o();
1078   _exits.set_i_o(gvn().transform(iophi));
1079 
1080   // Figure out if we need to emit the trailing barrier. The barrier is only
1081   // needed in the constructors, and only in three cases:
1082   //
1083   // 1. The constructor wrote a final or a @Stable field. All these
1084   //    initializations must be ordered before any code after the constructor
1085   //    publishes the reference to the newly constructed object. Rather
1086   //    than wait for the publication, we simply block the writes here.
1087   //    Rather than put a barrier on only those writes which are required
1088   //    to complete, we force all writes to complete.
1089   //
1090   // 2. Experimental VM option is used to force the barrier if any field
1091   //    was written out in the constructor.
1092   //
1093   // 3. On processors which are not CPU_MULTI_COPY_ATOMIC (e.g. PPC64),
1094   //    support_IRIW_for_not_multiple_copy_atomic_cpu selects that
1095   //    MemBarVolatile is used before volatile load instead of after volatile
1096   //    store, so there's no barrier after the store.
1097   //    We want to guarantee the same behavior as on platforms with total store
1098   //    order, although this is not required by the Java memory model.
1099   //    In this case, we want to enforce visibility of volatile field
1100   //    initializations which are performed in constructors.
1101   //    So as with finals, we add a barrier here.
1102   //
1103   // "All bets are off" unless the first publication occurs after a
1104   // normal return from the constructor.  We do not attempt to detect
1105   // such unusual early publications.  But no barrier is needed on
1106   // exceptional returns, since they cannot publish normally.
1107   //
1108   if ((method()->is_object_constructor() || method()->is_class_initializer()) &&
1109        (wrote_non_strict_final() || wrote_stable() ||
1110          (AlwaysSafeConstructors && wrote_fields()) ||
1111          (support_IRIW_for_not_multiple_copy_atomic_cpu && wrote_volatile()))) {
1112     Node* recorded_alloc = alloc_with_final_or_stable();
1113     _exits.insert_mem_bar(UseStoreStoreForCtor ? Op_MemBarStoreStore : Op_MemBarRelease,
1114                           recorded_alloc);
1115 
1116     // If Memory barrier is created for final fields write
1117     // and allocation node does not escape the initialize method,
1118     // then barrier introduced by allocation node can be removed.
1119     if (DoEscapeAnalysis && (recorded_alloc != nullptr)) {
1120       AllocateNode* alloc = AllocateNode::Ideal_allocation(recorded_alloc);
1121       alloc->compute_MemBar_redundancy(method());
1122     }
1123     if (PrintOpto && (Verbose || WizardMode)) {
1124       method()->print_name();
1125       tty->print_cr(" writes finals/@Stable and needs a memory barrier");
1126     }
1127   }
1128 
1129   for (MergeMemStream mms(_exits.merged_memory()); mms.next_non_empty(); ) {
1130     // transform each slice of the original memphi:
1131     mms.set_memory(_gvn.transform(mms.memory()));
1132   }
1133   // Clean up input MergeMems created by transforming the slices
1134   _gvn.transform(_exits.merged_memory());
1135 
1136   if (tf()->range_sig()->cnt() > TypeFunc::Parms) {
1137     const Type* ret_type = tf()->range_sig()->field_at(TypeFunc::Parms);
1138     Node*       ret_phi  = _gvn.transform( _exits.argument(0) );
1139     if (!_exits.control()->is_top() && _gvn.type(ret_phi)->empty()) {
1140       // If the type we set for the ret_phi in build_exits() is too optimistic and
1141       // the ret_phi is top now, there's an extremely small chance that it may be due to class
1142       // loading.  It could also be due to an error, so mark this method as not compilable because
1143       // otherwise this could lead to an infinite compile loop.
1144       // In any case, this code path is rarely (and never in my testing) reached.
1145       C->record_method_not_compilable("Can't determine return type.");
1146       return;
1147     }
1148     if (ret_type->isa_int()) {
1149       BasicType ret_bt = method()->return_type()->basic_type();
1150       ret_phi = mask_int_value(ret_phi, ret_bt, &_gvn);
1151     }
1152     _exits.push_node(ret_type->basic_type(), ret_phi);
1153   }
1154 
1155   // Note:  Logic for creating and optimizing the ReturnNode is in Compile.
1156 
1157   // Unlock along the exceptional paths.
1158   // This is done late so that we can common up equivalent exceptions
1159   // (e.g., null checks) arising from multiple points within this method.
1160   // See GraphKit::add_exception_state, which performs the commoning.
1161   bool do_synch = method()->is_synchronized();
1162 
1163   // record exit from a method if compiled while Dtrace is turned on.
1164   if (do_synch || C->env()->dtrace_method_probes() || _replaced_nodes_for_exceptions) {
1165     // First move the exception list out of _exits:
1166     GraphKit kit(_exits.transfer_exceptions_into_jvms());
1167     SafePointNode* normal_map = kit.map();  // keep this guy safe
1168     // Now re-collect the exceptions into _exits:
1169     SafePointNode* ex_map;
1170     while ((ex_map = kit.pop_exception_state()) != nullptr) {
1171       Node* ex_oop = kit.use_exception_state(ex_map);
1172       // Force the exiting JVM state to have this method at InvocationEntryBci.
1173       // The exiting JVM state is otherwise a copy of the calling JVMS.
1174       JVMState* caller = kit.jvms();
1175       JVMState* ex_jvms = caller->clone_shallow(C);
1176       ex_jvms->bind_map(kit.clone_map());
1177       ex_jvms->set_bci(   InvocationEntryBci);
1178       kit.set_jvms(ex_jvms);
1179       if (do_synch) {
1180         // Add on the synchronized-method box/object combo
1181         kit.map()->push_monitor(_synch_lock);
1182         // Unlock!
1183         kit.shared_unlock(_synch_lock->box_node(), _synch_lock->obj_node());
1184       }
1185       if (C->env()->dtrace_method_probes()) {
1186         kit.make_dtrace_method_exit(method());
1187       }
1188       if (_replaced_nodes_for_exceptions) {
1189         kit.map()->apply_replaced_nodes(_new_idx);
1190       }
1191       // Done with exception-path processing.
1192       ex_map = kit.make_exception_state(ex_oop);
1193       assert(ex_jvms->same_calls_as(ex_map->jvms()), "sanity");
1194       // Pop the last vestige of this method:
1195       caller->clone_shallow(C)->bind_map(ex_map);
1196       _exits.push_exception_state(ex_map);
1197     }
1198     assert(_exits.map() == normal_map, "keep the same return state");
1199   }
1200 
1201   {
1202     // Capture very early exceptions (receiver null checks) from caller JVMS
1203     GraphKit caller(_caller);
1204     SafePointNode* ex_map;
1205     while ((ex_map = caller.pop_exception_state()) != nullptr) {
1206       _exits.add_exception_state(ex_map);
1207     }
1208   }
1209   _exits.map()->apply_replaced_nodes(_new_idx);
1210 }
1211 
1212 //-----------------------------create_entry_map-------------------------------
1213 // Initialize our parser map to contain the types at method entry.
1214 // For OSR, the map contains a single RawPtr parameter.
1215 // Initial monitor locking for sync. methods is performed by do_method_entry.
1216 SafePointNode* Parse::create_entry_map() {
1217   // Check for really stupid bail-out cases.
1218   uint len = TypeFunc::Parms + method()->max_locals() + method()->max_stack();
1219   if (len >= 32760) {
1220     // Bailout expected, this is a very rare edge case.
1221     C->record_method_not_compilable("too many local variables");
1222     return nullptr;
1223   }
1224 
1225   // clear current replaced nodes that are of no use from here on (map was cloned in build_exits).
1226   _caller->map()->delete_replaced_nodes();
1227 
1228   // If this is an inlined method, we may have to do a receiver null check.
1229   if (_caller->has_method() && is_normal_parse() && !method()->is_static()) {
1230     GraphKit kit(_caller);
1231     kit.null_check_receiver_before_call(method());
1232     _caller = kit.transfer_exceptions_into_jvms();
1233 
1234     if (kit.stopped()) {
1235       _exits.add_exception_states_from(_caller);
1236       _exits.set_jvms(_caller);
1237       return nullptr;
1238     }
1239   }
1240 
1241   assert(method() != nullptr, "parser must have a method");
1242 
1243   // Create an initial safepoint to hold JVM state during parsing
1244   JVMState* jvms = new (C) JVMState(method(), _caller->has_method() ? _caller : nullptr);
1245   set_map(new SafePointNode(len, jvms));
1246 
1247   // Capture receiver info for compiled lambda forms.
1248   if (method()->is_compiled_lambda_form()) {
1249     ciInstance* recv_info = _caller->compute_receiver_info(method());
1250     jvms->set_receiver_info(recv_info);
1251   }
1252 
1253   jvms->set_map(map());
1254   record_for_igvn(map());
1255   assert(jvms->endoff() == len, "correct jvms sizing");
1256 
1257   SafePointNode* inmap = _caller->map();
1258   assert(inmap != nullptr, "must have inmap");
1259   // In case of null check on receiver above
1260   map()->transfer_replaced_nodes_from(inmap, _new_idx);
1261 
1262   uint i;
1263 
1264   // Pass thru the predefined input parameters.
1265   for (i = 0; i < TypeFunc::Parms; i++) {
1266     map()->init_req(i, inmap->in(i));
1267   }
1268 
1269   if (depth() == 1) {
1270     assert(map()->memory()->Opcode() == Op_Parm, "");
1271     // Insert the memory aliasing node
1272     set_all_memory(reset_memory());
1273   }
1274   assert(merged_memory(), "");
1275 
1276   // Now add the locals which are initially bound to arguments:
1277   uint arg_size = tf()->domain_sig()->cnt();
1278   ensure_stack(arg_size - TypeFunc::Parms);  // OSR methods have funny args
1279   for (i = TypeFunc::Parms; i < arg_size; i++) {
1280     map()->init_req(i, inmap->argument(_caller, i - TypeFunc::Parms));
1281   }
1282 
1283   // Clear out the rest of the map (locals and stack)
1284   for (i = arg_size; i < len; i++) {
1285     map()->init_req(i, top());
1286   }
1287 
1288   SafePointNode* entry_map = stop();
1289   return entry_map;
1290 }
1291 
1292 //-----------------------is_auto_boxed_primitive------------------------------
1293 // Helper method to detect auto-boxed primitives (result of valueOf() call).
1294 static bool is_auto_boxed_primitive(Node* n) {
1295   return (n->is_Proj() && n->as_Proj()->_con == TypeFunc::Parms &&
1296           n->in(0)->is_CallJava() &&
1297           n->in(0)->as_CallJava()->method()->is_boxing_method());
1298 }
1299 
1300 //-----------------------------do_method_entry--------------------------------
1301 // Emit any code needed in the pseudo-block before BCI zero.
1302 // The main thing to do is lock the receiver of a synchronized method.
1303 void Parse::do_method_entry() {
1304   set_parse_bci(InvocationEntryBci); // Pseudo-BCP
1305   set_sp(0);                         // Java Stack Pointer
1306 
1307   NOT_PRODUCT( count_compiled_calls(true/*at_method_entry*/, false/*is_inline*/); )
1308 
1309   // Check if we need a membar at the beginning of the java.lang.Object
1310   // constructor to satisfy the memory model for strict fields.
1311   if (Arguments::is_valhalla_enabled() && method()->intrinsic_id() == vmIntrinsics::_Object_init) {
1312     Node* receiver_obj = local(0);
1313     const TypeInstPtr* receiver_type = _gvn.type(receiver_obj)->isa_instptr();
1314     // If there's no exact type, check if the declared type has no implementors and add a dependency
1315     const TypeKlassPtr* klass_ptr = receiver_type->as_klass_type(/* try_for_exact= */ true);
1316     ciType* klass = klass_ptr->klass_is_exact() ? klass_ptr->exact_klass() : nullptr;
1317     if (klass != nullptr && klass->is_instance_klass()) {
1318       // Exact receiver type, check if there is a strict field
1319       ciInstanceKlass* holder = klass->as_instance_klass();
1320       for (int i = 0; i < holder->nof_nonstatic_fields(); i++) {
1321         ciField* field = holder->nonstatic_field_at(i);
1322         if (field->is_strict()) {
1323           // Found a strict field, a membar is needed
1324           AllocateNode* alloc = AllocateNode::Ideal_allocation(receiver_obj);
1325           insert_mem_bar(UseStoreStoreForCtor ? Op_MemBarStoreStore : Op_MemBarRelease, receiver_obj);
1326           if (DoEscapeAnalysis && (alloc != nullptr)) {
1327             alloc->compute_MemBar_redundancy(method());
1328           }
1329           break;
1330         }
1331       }
1332     } else if (klass == nullptr) {
1333       // We can't statically determine the type of the receiver and therefore need
1334       // to put a membar here because it could have a strict field.
1335       insert_mem_bar(UseStoreStoreForCtor ? Op_MemBarStoreStore : Op_MemBarRelease);
1336     }
1337   }
1338 
1339   if (C->env()->dtrace_method_probes()) {
1340     make_dtrace_method_entry(method());
1341   }
1342 
1343   if (StressReachabilityFences) {
1344     // Keep all oop arguments alive until the method returns as if there are
1345     // reachability fences for them at the end of the method.
1346     int max_locals = jvms()->loc_size();
1347     for (int idx = 0; idx < max_locals; idx++) {
1348       Node* loc = local(idx);
1349       if (loc->bottom_type()->isa_oopptr() != nullptr &&
1350           !is_auto_boxed_primitive(loc)) { // ignore auto-boxed primitives
1351         _stress_rf_hook->add_req(loc);
1352       }
1353     }
1354   }
1355 
1356 #ifdef ASSERT
1357   // Narrow receiver type when it is too broad for the method being parsed.
1358   if (!method()->is_static()) {
1359     ciInstanceKlass* callee_holder = method()->holder();
1360     const Type* holder_type = TypeInstPtr::make(TypePtr::BotPTR, callee_holder, Type::trust_interfaces);
1361 
1362     Node* receiver_obj = local(0);
1363     const TypeInstPtr* receiver_type = _gvn.type(receiver_obj)->isa_instptr();
1364 
1365     if (receiver_type != nullptr && !receiver_type->higher_equal(holder_type)) {
1366       // Receiver should always be a subtype of callee holder.
1367       // But, since C2 type system doesn't properly track interfaces,
1368       // the invariant can't be expressed in the type system for default methods.
1369       // Example: for unrelated C <: I and D <: I, (C `meet` D) = Object </: I.
1370       assert(callee_holder->is_interface(), "missing subtype check");
1371 
1372       // Perform dynamic receiver subtype check against callee holder class w/ a halt on failure.
1373       Node* holder_klass = _gvn.makecon(TypeKlassPtr::make(callee_holder, Type::trust_interfaces));
1374       Node* not_subtype_ctrl = gen_subtype_check(receiver_obj, holder_klass);
1375       assert(!stopped(), "not a subtype");
1376 
1377       halt(not_subtype_ctrl, frameptr(), "failed receiver subtype check");
1378     }
1379   }
1380 #endif // ASSERT
1381 
1382   // If the method is synchronized, we need to construct a lock node, attach
1383   // it to the Start node, and pin it there.
1384   if (method()->is_synchronized()) {
1385     // Insert a FastLockNode right after the Start which takes as arguments
1386     // the current thread pointer, the "this" pointer & the address of the
1387     // stack slot pair used for the lock.  The "this" pointer is a projection
1388     // off the start node, but the locking spot has to be constructed by
1389     // creating a ConLNode of 0, and boxing it with a BoxLockNode.  The BoxLockNode
1390     // becomes the second argument to the FastLockNode call.  The
1391     // FastLockNode becomes the new control parent to pin it to the start.
1392 
1393     // Setup Object Pointer
1394     Node *lock_obj = nullptr;
1395     if (method()->is_static()) {
1396       ciInstance* mirror = _method->holder()->java_mirror();
1397       const TypeInstPtr *t_lock = TypeInstPtr::make(mirror);
1398       lock_obj = makecon(t_lock);
1399     } else {                  // Else pass the "this" pointer,
1400       lock_obj = local(0);    // which is Parm0 from StartNode
1401       assert(!_gvn.type(lock_obj)->make_oopptr()->can_be_inline_type(), "can't be an inline type");
1402     }
1403     // Clear out dead values from the debug info.
1404     kill_dead_locals();
1405     // Build the FastLockNode
1406     _synch_lock = shared_lock(lock_obj);
1407     // Check for bailout in shared_lock
1408     if (failing()) { return; }
1409   }
1410 
1411   // Feed profiling data for parameters to the type system so it can
1412   // propagate it as speculative types
1413   record_profiled_parameters_for_speculation();
1414 
1415   // More argument handling
1416   int arg_size = method()->arg_size();
1417   for (int i = 0; i < arg_size; i++) {
1418     Node* parm = local(i);
1419     const Type* t = _gvn.type(parm);
1420     if (t->is_inlinetypeptr()) {
1421       // If the parameter is a value object, try to scalarize it if we know that it is unrestricted (not early larval)
1422       // Parameters are non-larval except the receiver of a constructor, which must be an early larval object.
1423       if (!(i == 0 && method()->receiver_maybe_larval())) {
1424         // Create InlineTypeNode from the oop and replace the parameter
1425         Node* vt = InlineTypeNode::make_from_oop(this, parm, t->inline_klass());
1426         replace_in_map(parm, vt);
1427       }
1428     } else if (UseTypeSpeculation && (i == (arg_size - 1)) && depth() == 1 && method()->has_vararg() && t->isa_aryptr()) {
1429       // Speculate on varargs Object array being the default array refined type. The assumption is
1430       // that a vararg method test(Object... o) is often called as test(o1, o2, o3). javac will
1431       // translate the call so that the caller will create a new default array of Object, put o1,
1432       // o2, o3 into the newly created array, then invoke the method test. This only makes sense if
1433       // the method we are parsing is the top-level method of the compilation unit. Otherwise, if
1434       // it is truly called according to our assumption, we must know the exact type of the
1435       // argument because the allocation happens inside the compilation unit.
1436       const TypePtr* spec_type = (t->speculative() != nullptr) ? t->speculative() : t->remove_speculative()->is_aryptr();
1437       ciSignature* method_signature = method()->signature();
1438       ciType* parm_citype = method_signature->type_at(method_signature->count() - 1);
1439       if (!parm_citype->is_obj_array_klass()) {
1440         continue;
1441       }
1442 
1443       ciObjArrayKlass* spec_citype = ciObjArrayKlass::make(parm_citype->as_obj_array_klass()->element_klass(), true);
1444       const Type* improved_spec_type = TypeKlassPtr::make(spec_citype, Type::trust_interfaces)->as_instance_type();
1445       improved_spec_type = improved_spec_type->join(spec_type)->join(TypePtr::NOTNULL);
1446       if (improved_spec_type->empty()) {
1447         continue;
1448       }
1449 
1450       const TypePtr* improved_type = TypeOopPtr::make(TypePtr::BotPTR, Type::Offset::bottom, TypeOopPtr::InstanceBot, improved_spec_type->is_ptr());
1451       improved_type = improved_type->join_speculative(t)->is_ptr();
1452       if (improved_type != t) {
1453         Node* cast = _gvn.transform(new CheckCastPPNode(control(), parm, improved_type, ConstraintCastNode::DependencyType::NonFloatingNarrowing));
1454         replace_in_map(parm, cast);
1455       }
1456     }
1457   }
1458 }
1459 
1460 //------------------------------init_blocks------------------------------------
1461 // Initialize our parser map to contain the types/monitors at method entry.
1462 void Parse::init_blocks() {
1463   // Create the blocks.
1464   _block_count = flow()->block_count();
1465   _blocks = NEW_RESOURCE_ARRAY(Block, _block_count);
1466 
1467   // Initialize the structs.
1468   for (int rpo = 0; rpo < block_count(); rpo++) {
1469     Block* block = rpo_at(rpo);
1470     new(block) Block(this, rpo);
1471   }
1472 
1473   // Collect predecessor and successor information.
1474   for (int rpo = 0; rpo < block_count(); rpo++) {
1475     Block* block = rpo_at(rpo);
1476     block->init_graph(this);
1477   }
1478 }
1479 
1480 //-------------------------------init_node-------------------------------------
1481 Parse::Block::Block(Parse* outer, int rpo) : _live_locals() {
1482   _flow = outer->flow()->rpo_at(rpo);
1483   _pred_count = 0;
1484   _preds_parsed = 0;
1485   _count = 0;
1486   _is_parsed = false;
1487   _is_handler = false;
1488   _has_merged_backedge = false;
1489   _start_map = nullptr;
1490   _has_predicates = false;
1491   _num_successors = 0;
1492   _all_successors = 0;
1493   _successors = nullptr;
1494   assert(pred_count() == 0 && preds_parsed() == 0, "sanity");
1495   assert(!(is_merged() || is_parsed() || is_handler() || has_merged_backedge()), "sanity");
1496   assert(_live_locals.size() == 0, "sanity");
1497 
1498   // entry point has additional predecessor
1499   if (flow()->is_start())  _pred_count++;
1500   assert(flow()->is_start() == (this == outer->start_block()), "");
1501 }
1502 
1503 //-------------------------------init_graph------------------------------------
1504 void Parse::Block::init_graph(Parse* outer) {
1505   // Create the successor list for this parser block.
1506   GrowableArray<ciTypeFlow::Block*>* tfs = flow()->successors();
1507   GrowableArray<ciTypeFlow::Block*>* tfe = flow()->exceptions();
1508   int ns = tfs->length();
1509   int ne = tfe->length();
1510   _num_successors = ns;
1511   _all_successors = ns+ne;
1512   _successors = (ns+ne == 0) ? nullptr : NEW_RESOURCE_ARRAY(Block*, ns+ne);
1513   int p = 0;
1514   for (int i = 0; i < ns+ne; i++) {
1515     ciTypeFlow::Block* tf2 = (i < ns) ? tfs->at(i) : tfe->at(i-ns);
1516     Block* block2 = outer->rpo_at(tf2->rpo());
1517     _successors[i] = block2;
1518 
1519     // Accumulate pred info for the other block, too.
1520     // Note: We also need to set _pred_count for exception blocks since they could
1521     // also have normal predecessors (reached without athrow by an explicit jump).
1522     // This also means that next_path_num can be called along exception paths.
1523     block2->_pred_count++;
1524     if (i >= ns) {
1525       block2->_is_handler = true;
1526     }
1527 
1528     #ifdef ASSERT
1529     // A block's successors must be distinguishable by BCI.
1530     // That is, no bytecode is allowed to branch to two different
1531     // clones of the same code location.
1532     for (int j = 0; j < i; j++) {
1533       Block* block1 = _successors[j];
1534       if (block1 == block2)  continue;  // duplicates are OK
1535       assert(block1->start() != block2->start(), "successors have unique bcis");
1536     }
1537     #endif
1538   }
1539 }
1540 
1541 //---------------------------successor_for_bci---------------------------------
1542 Parse::Block* Parse::Block::successor_for_bci(int bci) {
1543   for (int i = 0; i < all_successors(); i++) {
1544     Block* block2 = successor_at(i);
1545     if (block2->start() == bci)  return block2;
1546   }
1547   // We can actually reach here if ciTypeFlow traps out a block
1548   // due to an unloaded class, and concurrently with compilation the
1549   // class is then loaded, so that a later phase of the parser is
1550   // able to see more of the bytecode CFG.  Or, the flow pass and
1551   // the parser can have a minor difference of opinion about executability
1552   // of bytecodes.  For example, "obj.field = null" is executable even
1553   // if the field's type is an unloaded class; the flow pass used to
1554   // make a trap for such code.
1555   return nullptr;
1556 }
1557 
1558 
1559 //-----------------------------stack_type_at-----------------------------------
1560 const Type* Parse::Block::stack_type_at(int i) const {
1561   return get_type(flow()->stack_type_at(i));
1562 }
1563 
1564 
1565 //-----------------------------local_type_at-----------------------------------
1566 const Type* Parse::Block::local_type_at(int i) const {
1567   // Make dead locals fall to bottom.
1568   if (_live_locals.size() == 0) {
1569     MethodLivenessResult live_locals = flow()->outer()->method()->liveness_at_bci(start());
1570     // This bitmap can be zero length if we saw a breakpoint.
1571     // In such cases, pretend they are all live.
1572     ((Block*)this)->_live_locals = live_locals;
1573   }
1574   if (_live_locals.size() > 0 && !_live_locals.at(i))
1575     return Type::BOTTOM;
1576 
1577   return get_type(flow()->local_type_at(i));
1578 }
1579 
1580 
1581 #ifndef PRODUCT
1582 
1583 //----------------------------name_for_bc--------------------------------------
1584 // helper method for BytecodeParseHistogram
1585 static const char* name_for_bc(int i) {
1586   return Bytecodes::is_defined(i) ? Bytecodes::name(Bytecodes::cast(i)) : "xxxunusedxxx";
1587 }
1588 
1589 //----------------------------BytecodeParseHistogram------------------------------------
1590 Parse::BytecodeParseHistogram::BytecodeParseHistogram(Parse *p, Compile *c) {
1591   _parser   = p;
1592   _compiler = c;
1593   if( ! _initialized ) { _initialized = true; reset(); }
1594 }
1595 
1596 //----------------------------current_count------------------------------------
1597 int Parse::BytecodeParseHistogram::current_count(BPHType bph_type) {
1598   switch( bph_type ) {
1599   case BPH_transforms: { return _parser->gvn().made_progress(); }
1600   case BPH_values:     { return _parser->gvn().made_new_values(); }
1601   default: { ShouldNotReachHere(); return 0; }
1602   }
1603 }
1604 
1605 //----------------------------initialized--------------------------------------
1606 bool Parse::BytecodeParseHistogram::initialized() { return _initialized; }
1607 
1608 //----------------------------reset--------------------------------------------
1609 void Parse::BytecodeParseHistogram::reset() {
1610   int i = Bytecodes::number_of_codes;
1611   while (i-- > 0) { _bytecodes_parsed[i] = 0; _nodes_constructed[i] = 0; _nodes_transformed[i] = 0; _new_values[i] = 0; }
1612 }
1613 
1614 //----------------------------set_initial_state--------------------------------
1615 // Record info when starting to parse one bytecode
1616 void Parse::BytecodeParseHistogram::set_initial_state( Bytecodes::Code bc ) {
1617   if( PrintParseStatistics && !_parser->is_osr_parse() ) {
1618     _initial_bytecode    = bc;
1619     _initial_node_count  = _compiler->unique();
1620     _initial_transforms  = current_count(BPH_transforms);
1621     _initial_values      = current_count(BPH_values);
1622   }
1623 }
1624 
1625 //----------------------------record_change--------------------------------
1626 // Record results of parsing one bytecode
1627 void Parse::BytecodeParseHistogram::record_change() {
1628   if( PrintParseStatistics && !_parser->is_osr_parse() ) {
1629     ++_bytecodes_parsed[_initial_bytecode];
1630     _nodes_constructed [_initial_bytecode] += (_compiler->unique() - _initial_node_count);
1631     _nodes_transformed [_initial_bytecode] += (current_count(BPH_transforms) - _initial_transforms);
1632     _new_values        [_initial_bytecode] += (current_count(BPH_values)     - _initial_values);
1633   }
1634 }
1635 
1636 
1637 //----------------------------print--------------------------------------------
1638 void Parse::BytecodeParseHistogram::print(float cutoff) {
1639   ResourceMark rm;
1640   // print profile
1641   int total  = 0;
1642   int i      = 0;
1643   for( i = 0; i < Bytecodes::number_of_codes; ++i ) { total += _bytecodes_parsed[i]; }
1644   int abs_sum = 0;
1645   tty->cr();   //0123456789012345678901234567890123456789012345678901234567890123456789
1646   tty->print_cr("Histogram of %d parsed bytecodes:", total);
1647   if( total == 0 ) { return; }
1648   tty->cr();
1649   tty->print_cr("absolute:  count of compiled bytecodes of this type");
1650   tty->print_cr("relative:  percentage contribution to compiled nodes");
1651   tty->print_cr("nodes   :  Average number of nodes constructed per bytecode");
1652   tty->print_cr("rnodes  :  Significance towards total nodes constructed, (nodes*relative)");
1653   tty->print_cr("transforms: Average amount of transform progress per bytecode compiled");
1654   tty->print_cr("values  :  Average number of node values improved per bytecode");
1655   tty->print_cr("name    :  Bytecode name");
1656   tty->cr();
1657   tty->print_cr("  absolute  relative   nodes  rnodes  transforms  values   name");
1658   tty->print_cr("----------------------------------------------------------------------");
1659   while (--i > 0) {
1660     int       abs = _bytecodes_parsed[i];
1661     float     rel = abs * 100.0F / total;
1662     float   nodes = _bytecodes_parsed[i] == 0 ? 0 : (1.0F * _nodes_constructed[i])/_bytecodes_parsed[i];
1663     float  rnodes = _bytecodes_parsed[i] == 0 ? 0 :  rel * nodes;
1664     float  xforms = _bytecodes_parsed[i] == 0 ? 0 : (1.0F * _nodes_transformed[i])/_bytecodes_parsed[i];
1665     float  values = _bytecodes_parsed[i] == 0 ? 0 : (1.0F * _new_values       [i])/_bytecodes_parsed[i];
1666     if (cutoff <= rel) {
1667       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));
1668       abs_sum += abs;
1669     }
1670   }
1671   tty->print_cr("----------------------------------------------------------------------");
1672   float rel_sum = abs_sum * 100.0F / total;
1673   tty->print_cr("%10d  %7.2f%%    (cutoff = %.2f%%)", abs_sum, rel_sum, cutoff);
1674   tty->print_cr("----------------------------------------------------------------------");
1675   tty->cr();
1676 }
1677 #endif
1678 
1679 //----------------------------load_state_from----------------------------------
1680 // Load block/map/sp.  But not do not touch iter/bci.
1681 void Parse::load_state_from(Block* block) {
1682   set_block(block);
1683   // load the block's JVM state:
1684   set_map(block->start_map());
1685   set_sp( block->start_sp());
1686 }
1687 
1688 
1689 //-----------------------------record_state------------------------------------
1690 void Parse::Block::record_state(Parse* p) {
1691   assert(!is_merged(), "can only record state once, on 1st inflow");
1692   assert(start_sp() == p->sp(), "stack pointer must agree with ciTypeFlow");
1693   set_start_map(p->stop());
1694 }
1695 
1696 
1697 //------------------------------do_one_block-----------------------------------
1698 void Parse::do_one_block() {
1699   if (TraceOptoParse) {
1700     Block *b = block();
1701     int ns = b->num_successors();
1702     int nt = b->all_successors();
1703 
1704     tty->print("Parsing block #%d at bci [%d,%d), successors:",
1705                   block()->rpo(), block()->start(), block()->limit());
1706     for (int i = 0; i < nt; i++) {
1707       tty->print((( i < ns) ? " %d" : " %d(exception block)"), b->successor_at(i)->rpo());
1708     }
1709     if (b->is_loop_head()) {
1710       tty->print("  loop head");
1711     }
1712     if (b->is_irreducible_loop_entry()) {
1713       tty->print("  irreducible");
1714     }
1715     tty->cr();
1716   }
1717 
1718   assert(block()->is_merged(), "must be merged before being parsed");
1719   block()->mark_parsed();
1720 
1721   // Set iterator to start of block.
1722   iter().reset_to_bci(block()->start());
1723 
1724   if (ProfileExceptionHandlers && block()->is_handler()) {
1725     ciMethodData* methodData = method()->method_data();
1726     if (methodData->is_mature()) {
1727       ciBitData data = methodData->exception_handler_bci_to_data(block()->start());
1728       if (!data.exception_handler_entered() || StressPrunedExceptionHandlers) {
1729         // dead catch block
1730         // Emit an uncommon trap instead of processing the block.
1731         set_parse_bci(block()->start());
1732         uncommon_trap(Deoptimization::Reason_unreached,
1733                       Deoptimization::Action_reinterpret,
1734                       nullptr, "dead catch block");
1735         return;
1736       }
1737     }
1738   }
1739 
1740   CompileLog* log = C->log();
1741 
1742   // Parse bytecodes
1743   while (!stopped() && !failing()) {
1744     iter().next();
1745 
1746     // Learn the current bci from the iterator:
1747     set_parse_bci(iter().cur_bci());
1748 
1749     if (bci() == block()->limit()) {
1750       // Do not walk into the next block until directed by do_all_blocks.
1751       merge(bci());
1752       break;
1753     }
1754     assert(bci() < block()->limit(), "bci still in block");
1755 
1756     if (log != nullptr) {
1757       // Output an optional context marker, to help place actions
1758       // that occur during parsing of this BC.  If there is no log
1759       // output until the next context string, this context string
1760       // will be silently ignored.
1761       log->set_context("bc code='%d' bci='%d'", (int)bc(), bci());
1762     }
1763 
1764     if (block()->has_trap_at(bci())) {
1765       // We must respect the flow pass's traps, because it will refuse
1766       // to produce successors for trapping blocks.
1767       int trap_index = block()->flow()->trap_index();
1768       assert(trap_index != 0, "trap index must be valid");
1769       uncommon_trap(trap_index);
1770       break;
1771     }
1772 
1773     NOT_PRODUCT( parse_histogram()->set_initial_state(bc()); );
1774 
1775 #ifdef ASSERT
1776     int pre_bc_sp = sp();
1777     int inputs, depth;
1778     bool have_se = !stopped() && compute_stack_effects(inputs, depth);
1779     assert(!have_se || pre_bc_sp >= inputs, "have enough stack to execute this BC: pre_bc_sp=%d, inputs=%d", pre_bc_sp, inputs);
1780 #endif //ASSERT
1781 
1782     do_one_bytecode();
1783     if (failing()) return;
1784 
1785     assert(!have_se || stopped() || failing() || (sp() - pre_bc_sp) == depth,
1786            "incorrect depth prediction: sp=%d, pre_bc_sp=%d, depth=%d", sp(), pre_bc_sp, depth);
1787 
1788     do_exceptions();
1789 
1790     NOT_PRODUCT( parse_histogram()->record_change(); );
1791 
1792     if (log != nullptr)
1793       log->clear_context();  // skip marker if nothing was printed
1794 
1795     // Fall into next bytecode.  Each bytecode normally has 1 sequential
1796     // successor which is typically made ready by visiting this bytecode.
1797     // If the successor has several predecessors, then it is a merge
1798     // point, starts a new basic block, and is handled like other basic blocks.
1799   }
1800 }
1801 
1802 
1803 //------------------------------merge------------------------------------------
1804 void Parse::set_parse_bci(int bci) {
1805   set_bci(bci);
1806   Node_Notes* nn = C->default_node_notes();
1807   if (nn == nullptr)  return;
1808 
1809   // Collect debug info for inlined calls unless -XX:-DebugInlinedCalls.
1810   if (!DebugInlinedCalls && depth() > 1) {
1811     return;
1812   }
1813 
1814   // Update the JVMS annotation, if present.
1815   JVMState* jvms = nn->jvms();
1816   if (jvms != nullptr && jvms->bci() != bci) {
1817     // Update the JVMS.
1818     jvms = jvms->clone_shallow(C);
1819     jvms->set_bci(bci);
1820     nn->set_jvms(jvms);
1821   }
1822 }
1823 
1824 //------------------------------merge------------------------------------------
1825 // Merge the current mapping into the basic block starting at bci
1826 void Parse::merge(int target_bci) {
1827   Block* target = successor_for_bci(target_bci);
1828   if (target == nullptr) { handle_missing_successor(target_bci); return; }
1829   assert(!target->is_ready(), "our arrival must be expected");
1830   int pnum = target->next_path_num();
1831   merge_common(target, pnum);
1832 }
1833 
1834 //-------------------------merge_new_path--------------------------------------
1835 // Merge the current mapping into the basic block, using a new path
1836 void Parse::merge_new_path(int target_bci) {
1837   Block* target = successor_for_bci(target_bci);
1838   if (target == nullptr) { handle_missing_successor(target_bci); return; }
1839   assert(!target->is_ready(), "new path into frozen graph");
1840   int pnum = target->add_new_path();
1841   merge_common(target, pnum);
1842 }
1843 
1844 //-------------------------merge_exception-------------------------------------
1845 // Push the given ex_oop onto the stack, then merge the current mapping into
1846 // the basic block starting at target_bci.
1847 void Parse::push_and_merge_exception(int target_bci, Node* ex_oop) {
1848   // Add the safepoint before trimming the stack and pushing the exception oop.
1849   // We could add the safepoint after, but then the bci would also need to be
1850   // advanced to target_bci first, so the stack state matches.
1851   maybe_add_safepoint(target_bci);
1852   push_ex_oop(ex_oop);      // Push exception oop for handler
1853 #ifdef ASSERT
1854   if (target_bci <= bci()) {
1855     C->set_exception_backedge();
1856   }
1857 #endif
1858   assert(sp() == 1, "must have only the throw exception on the stack");
1859   Block* target = successor_for_bci(target_bci);
1860   if (target == nullptr) { handle_missing_successor(target_bci); return; }
1861   assert(target->is_handler(), "exceptions are handled by special blocks");
1862   int pnum = target->add_new_path();
1863   merge_common(target, pnum);
1864 }
1865 
1866 //--------------------handle_missing_successor---------------------------------
1867 void Parse::handle_missing_successor(int target_bci) {
1868 #ifndef PRODUCT
1869   Block* b = block();
1870   int trap_bci = b->flow()->has_trap()? b->flow()->trap_bci(): -1;
1871   tty->print_cr("### Missing successor at bci:%d for block #%d (trap_bci:%d)", target_bci, b->rpo(), trap_bci);
1872 #endif
1873   ShouldNotReachHere();
1874 }
1875 
1876 //--------------------------merge_common---------------------------------------
1877 void Parse::merge_common(Parse::Block* target, int pnum) {
1878   if (TraceOptoParse) {
1879     tty->print("Merging state at block #%d bci:%d", target->rpo(), target->start());
1880   }
1881 
1882   // Zap extra stack slots to top
1883   assert(sp() == target->start_sp(), "");
1884   clean_stack(sp());
1885 
1886   // Check for merge conflicts involving inline types
1887   JVMState* old_jvms = map()->jvms();
1888   int old_bci = bci();
1889   JVMState* tmp_jvms = old_jvms->clone_shallow(C);
1890   tmp_jvms->set_should_reexecute(true);
1891   tmp_jvms->bind_map(map());
1892   // Execution needs to restart a the next bytecode (entry of next
1893   // block)
1894   if (target->is_merged() ||
1895       pnum > PhiNode::Input ||
1896       target->is_handler() ||
1897       target->is_loop_head()) {
1898     set_parse_bci(target->start());
1899     for (uint j = TypeFunc::Parms; j < map()->req(); j++) {
1900       Node* n = map()->in(j);                 // Incoming change to target state.
1901       const Type* t = nullptr;
1902       ciType* ct = nullptr;
1903       if (tmp_jvms->is_loc(j)) {
1904         int loc_idx = j - tmp_jvms->locoff();
1905         t = target->local_type_at(loc_idx);
1906         ct = target->flow()->local_type_at(loc_idx);
1907       } else if (tmp_jvms->is_stk(j) && j < (uint)sp() + tmp_jvms->stkoff()) {
1908         int stk_idx = j - tmp_jvms->stkoff();
1909         t = target->stack_type_at(stk_idx);
1910         ct = target->flow()->stack_type_at(stk_idx);
1911       }
1912       if (t != nullptr && t != Type::BOTTOM) {
1913         // An object can appear in the JVMS as either an oop or an InlineTypeNode. If the merge is
1914         // an InlineTypeNode, we need all the merge inputs to be InlineTypeNodes. Else, if the
1915         // merge is an oop, each merge input needs to be either an oop or an buffered
1916         // InlineTypeNode.
1917         if (!t->is_inlinetypeptr()) {
1918           // The merge cannot be an InlineTypeNode, ensure the input is buffered if it is an
1919           // InlineTypeNode
1920           if (n->is_InlineType()) {
1921             map()->set_req(j, n->as_InlineType()->buffer(this));
1922           }
1923         } else {
1924           // Scalarize the value object if it is not larval
1925           if (!n->is_InlineType() && !ct->is_early_larval()) {
1926             assert(_gvn.type(n) == TypePtr::NULL_PTR, "must be a null constant");
1927             map()->set_req(j, InlineTypeNode::make_null(_gvn, t->inline_klass()));
1928           }
1929         }
1930       }
1931     }
1932   }
1933   old_jvms->bind_map(map());
1934   set_parse_bci(old_bci);
1935 
1936   if (!target->is_merged()) {   // No prior mapping at this bci
1937     if (TraceOptoParse) { tty->print(" with empty state");  }
1938 
1939     // If this path is dead, do not bother capturing it as a merge.
1940     // It is "as if" we had 1 fewer predecessors from the beginning.
1941     if (stopped()) {
1942       if (TraceOptoParse)  tty->print_cr(", but path is dead and doesn't count");
1943       return;
1944     }
1945 
1946     // Make a region if we know there are multiple or unpredictable inputs.
1947     // (Also, if this is a plain fall-through, we might see another region,
1948     // which must not be allowed into this block's map.)
1949     if (pnum > PhiNode::Input         // Known multiple inputs.
1950         || target->is_handler()       // These have unpredictable inputs.
1951         || target->is_loop_head()     // Known multiple inputs
1952         || control()->is_Region()) {  // We must hide this guy.
1953 
1954       int current_bci = bci();
1955       set_parse_bci(target->start()); // Set target bci
1956       if (target->is_SEL_head()) {
1957         DEBUG_ONLY( target->mark_merged_backedge(block()); )
1958         if (target->start() == 0) {
1959           // Add Parse Predicates for the special case when
1960           // there are backbranches to the method entry.
1961           add_parse_predicates();
1962         }
1963       }
1964       // Add a Region to start the new basic block.  Phis will be added
1965       // later lazily.
1966       int edges = target->pred_count();
1967       if (edges < pnum)  edges = pnum;  // might be a new path!
1968       RegionNode *r = new RegionNode(edges+1);
1969       gvn().set_type(r, Type::CONTROL);
1970       record_for_igvn(r);
1971       // zap all inputs to null for debugging (done in Node(uint) constructor)
1972       // for (int j = 1; j < edges+1; j++) { r->init_req(j, nullptr); }
1973       r->init_req(pnum, control());
1974       set_control(r);
1975       target->copy_irreducible_status_to(r, jvms());
1976       set_parse_bci(current_bci); // Restore bci
1977     }
1978 
1979     // Convert the existing Parser mapping into a mapping at this bci.
1980     store_state_to(target);
1981     assert(target->is_merged(), "do not come here twice");
1982 
1983   } else {                      // Prior mapping at this bci
1984     if (TraceOptoParse) {  tty->print(" with previous state"); }
1985 #ifdef ASSERT
1986     if (target->is_SEL_head()) {
1987       target->mark_merged_backedge(block());
1988     }
1989 #endif
1990 
1991     // We must not manufacture more phis if the target is already parsed.
1992     bool nophi = target->is_parsed();
1993 
1994     SafePointNode* newin = map();// Hang on to incoming mapping
1995     Block* save_block = block(); // Hang on to incoming block;
1996     load_state_from(target);    // Get prior mapping
1997 
1998     assert(newin->jvms()->locoff() == jvms()->locoff(), "JVMS layouts agree");
1999     assert(newin->jvms()->stkoff() == jvms()->stkoff(), "JVMS layouts agree");
2000     assert(newin->jvms()->monoff() == jvms()->monoff(), "JVMS layouts agree");
2001     assert(newin->jvms()->endoff() == jvms()->endoff(), "JVMS layouts agree");
2002 
2003     // Iterate over my current mapping and the old mapping.
2004     // Where different, insert Phi functions.
2005     // Use any existing Phi functions.
2006     assert(control()->is_Region(), "must be merging to a region");
2007     RegionNode* r = control()->as_Region();
2008 
2009     // Compute where to merge into
2010     // Merge incoming control path
2011     r->init_req(pnum, newin->control());
2012 
2013     if (pnum == 1) {            // Last merge for this Region?
2014       if (!block()->flow()->is_irreducible_loop_secondary_entry()) {
2015         Node* result = _gvn.transform(r);
2016         if (r != result && TraceOptoParse) {
2017           tty->print_cr("Block #%d replace %d with %d", block()->rpo(), r->_idx, result->_idx);
2018         }
2019       }
2020       record_for_igvn(r);
2021     }
2022 
2023     // Update all the non-control inputs to map:
2024     assert(TypeFunc::Parms == newin->jvms()->locoff(), "parser map should contain only youngest jvms");
2025     bool check_elide_phi = target->is_SEL_backedge(save_block);
2026     bool last_merge = (pnum == PhiNode::Input);
2027     for (uint j = 1; j < newin->req(); j++) {
2028       Node* m = map()->in(j);   // Current state of target.
2029       Node* n = newin->in(j);   // Incoming change to target state.
2030       Node* phi;
2031       if (m->is_Phi() && m->as_Phi()->region() == r) {
2032         phi = m;
2033       } else if (m->is_InlineType() && m->as_InlineType()->has_phi_inputs(r)) {
2034         phi = m;
2035       } else {
2036         phi = nullptr;
2037       }
2038       if (m != n) {             // Different; must merge
2039         switch (j) {
2040         // Frame pointer and Return Address never changes
2041         case TypeFunc::FramePtr:// Drop m, use the original value
2042         case TypeFunc::ReturnAdr:
2043           break;
2044         case TypeFunc::Memory:  // Merge inputs to the MergeMem node
2045           assert(phi == nullptr, "the merge contains phis, not vice versa");
2046           merge_memory_edges(n->as_MergeMem(), pnum, nophi);
2047           continue;
2048         default:                // All normal stuff
2049           if (phi == nullptr) {
2050             const JVMState* jvms = map()->jvms();
2051             if (EliminateNestedLocks &&
2052                 jvms->is_mon(j) && jvms->is_monitor_box(j)) {
2053               // BoxLock nodes are not commoning when EliminateNestedLocks is on.
2054               // Use old BoxLock node as merged box.
2055               assert(newin->jvms()->is_monitor_box(j), "sanity");
2056               // This assert also tests that nodes are BoxLock.
2057               assert(BoxLockNode::same_slot(n, m), "sanity");
2058               BoxLockNode* old_box = m->as_BoxLock();
2059               if (n->as_BoxLock()->is_unbalanced() && !old_box->is_unbalanced()) {
2060                 // Preserve Unbalanced status.
2061                 //
2062                 // `old_box` can have only Regular or Coarsened status
2063                 // because this code is executed only during Parse phase and
2064                 // Incremental Inlining before EA and Macro nodes elimination.
2065                 //
2066                 // Incremental Inlining is executed after IGVN optimizations
2067                 // during which BoxLock can be marked as Coarsened.
2068                 old_box->set_coarsened(); // Verifies state
2069                 old_box->set_unbalanced();
2070               }
2071               C->gvn_replace_by(n, m);
2072             } else if (!check_elide_phi || !target->can_elide_SEL_phi(j)) {
2073               phi = ensure_phi(j, nophi);
2074             }
2075           }
2076           break;
2077         }
2078       }
2079       // At this point, n might be top if:
2080       //  - there is no phi (because TypeFlow detected a conflict), or
2081       //  - the corresponding control edges is top (a dead incoming path)
2082       // It is a bug if we create a phi which sees a garbage value on a live path.
2083 
2084       // Merging two inline types?
2085       if (phi != nullptr && phi->is_InlineType()) {
2086         // Reload current state because it may have been updated by ensure_phi
2087         assert(phi == map()->in(j), "unexpected value in map");
2088         assert(phi->as_InlineType()->has_phi_inputs(r), "");
2089         InlineTypeNode* vtm = phi->as_InlineType(); // Current inline type
2090         InlineTypeNode* vtn = n->as_InlineType(); // Incoming inline type
2091         assert(vtm == phi, "Inline type should have Phi input");
2092 
2093 #ifdef ASSERT
2094         if (TraceOptoParse) {
2095           tty->print_cr("\nMerging inline types");
2096           tty->print_cr("Current:");
2097           vtm->dump(2);
2098           tty->print_cr("Incoming:");
2099           vtn->dump(2);
2100           tty->cr();
2101         }
2102 #endif
2103         // Do the merge
2104         vtm->merge_with(&_gvn, vtn, pnum, last_merge);
2105         if (last_merge) {
2106           map()->set_req(j, _gvn.transform(vtm));
2107           record_for_igvn(vtm);
2108         }
2109       } else if (phi != nullptr) {
2110         assert(n != top() || r->in(pnum) == top(), "live value must not be garbage");
2111         assert(phi->as_Phi()->region() == r, "");
2112         phi->set_req(pnum, n);  // Then add 'n' to the merge
2113         if (last_merge) {
2114           // Last merge for this Phi.
2115           // So far, Phis have had a reasonable type from ciTypeFlow.
2116           // Now _gvn will join that with the meet of current inputs.
2117           // BOTTOM is never permissible here, 'cause pessimistically
2118           // Phis of pointers cannot lose the basic pointer type.
2119           DEBUG_ONLY(const Type* bt1 = phi->bottom_type());
2120           assert(bt1 != Type::BOTTOM, "should not be building conflict phis");
2121           map()->set_req(j, _gvn.transform(phi));
2122           DEBUG_ONLY(const Type* bt2 = phi->bottom_type());
2123           assert(bt2->higher_equal_speculative(bt1), "must be consistent with type-flow");
2124           record_for_igvn(phi);
2125         }
2126       }
2127     } // End of for all values to be merged
2128 
2129     if (last_merge && !r->in(0)) {         // The occasional useless Region
2130       assert(control() == r, "");
2131       set_control(r->nonnull_req());
2132     }
2133 
2134     map()->merge_replaced_nodes_with(newin);
2135 
2136     // newin has been subsumed into the lazy merge, and is now dead.
2137     set_block(save_block);
2138 
2139     stop();                     // done with this guy, for now
2140   }
2141 
2142   if (TraceOptoParse) {
2143     tty->print_cr(" on path %d", pnum);
2144   }
2145 
2146   // Done with this parser state.
2147   assert(stopped(), "");
2148 }
2149 
2150 
2151 //--------------------------merge_memory_edges---------------------------------
2152 void Parse::merge_memory_edges(MergeMemNode* n, int pnum, bool nophi) {
2153   // (nophi means we must not create phis, because we already parsed here)
2154   assert(n != nullptr, "");
2155   // Merge the inputs to the MergeMems
2156   MergeMemNode* m = merged_memory();
2157 
2158   assert(control()->is_Region(), "must be merging to a region");
2159   RegionNode* r = control()->as_Region();
2160 
2161   PhiNode* base = nullptr;
2162   MergeMemNode* remerge = nullptr;
2163   for (MergeMemStream mms(m, n); mms.next_non_empty2(); ) {
2164     Node *p = mms.force_memory();
2165     Node *q = mms.memory2();
2166     if (mms.is_empty() && nophi) {
2167       // Trouble:  No new splits allowed after a loop body is parsed.
2168       // Instead, wire the new split into a MergeMem on the backedge.
2169       // The optimizer will sort it out, slicing the phi.
2170       if (remerge == nullptr) {
2171         guarantee(base != nullptr, "");
2172         assert(base->in(0) != nullptr, "should not be xformed away");
2173         remerge = MergeMemNode::make(base->in(pnum));
2174         gvn().set_type(remerge, Type::MEMORY);
2175         base->set_req(pnum, remerge);
2176       }
2177       remerge->set_memory_at(mms.alias_idx(), q);
2178       continue;
2179     }
2180     assert(!q->is_MergeMem(), "");
2181     PhiNode* phi;
2182     if (p != q) {
2183       phi = ensure_memory_phi(mms.alias_idx(), nophi);
2184     } else {
2185       if (p->is_Phi() && p->as_Phi()->region() == r)
2186         phi = p->as_Phi();
2187       else
2188         phi = nullptr;
2189     }
2190     // Insert q into local phi
2191     if (phi != nullptr) {
2192       assert(phi->region() == r, "");
2193       p = phi;
2194       phi->set_req(pnum, q);
2195       if (mms.at_base_memory()) {
2196         base = phi;  // delay transforming it
2197       } else if (pnum == 1) {
2198         record_for_igvn(phi);
2199         p = _gvn.transform(phi);
2200       }
2201       mms.set_memory(p);// store back through the iterator
2202     }
2203   }
2204   // Transform base last, in case we must fiddle with remerging.
2205   if (base != nullptr && pnum == 1) {
2206     record_for_igvn(base);
2207     m->set_base_memory(_gvn.transform(base));
2208   }
2209 }
2210 
2211 
2212 //------------------------ensure_phis_everywhere-------------------------------
2213 void Parse::ensure_phis_everywhere() {
2214   ensure_phi(TypeFunc::I_O);
2215 
2216   // Ensure a phi on all currently known memories.
2217   for (MergeMemStream mms(merged_memory()); mms.next_non_empty(); ) {
2218     ensure_memory_phi(mms.alias_idx());
2219     DEBUG_ONLY(mms.set_memory());  // keep the iterator happy
2220   }
2221 
2222   // Note:  This is our only chance to create phis for memory slices.
2223   // If we miss a slice that crops up later, it will have to be
2224   // merged into the base-memory phi that we are building here.
2225   // Later, the optimizer will comb out the knot, and build separate
2226   // phi-loops for each memory slice that matters.
2227 
2228   // Monitors must nest nicely and not get confused amongst themselves.
2229   // Phi-ify everything up to the monitors, though.
2230   uint monoff = map()->jvms()->monoff();
2231   uint nof_monitors = map()->jvms()->nof_monitors();
2232 
2233   assert(TypeFunc::Parms == map()->jvms()->locoff(), "parser map should contain only youngest jvms");
2234   bool check_elide_phi = block()->is_SEL_head();
2235   for (uint i = TypeFunc::Parms; i < monoff; i++) {
2236     if (!check_elide_phi || !block()->can_elide_SEL_phi(i)) {
2237       ensure_phi(i);
2238     }
2239   }
2240 
2241   // Even monitors need Phis, though they are well-structured.
2242   // This is true for OSR methods, and also for the rare cases where
2243   // a monitor object is the subject of a replace_in_map operation.
2244   // See bugs 4426707 and 5043395.
2245   for (uint m = 0; m < nof_monitors; m++) {
2246     ensure_phi(map()->jvms()->monitor_obj_offset(m));
2247   }
2248 }
2249 
2250 
2251 //-----------------------------add_new_path------------------------------------
2252 // Add a previously unaccounted predecessor to this block.
2253 int Parse::Block::add_new_path() {
2254   // If there is no map, return the lowest unused path number.
2255   if (!is_merged())  return pred_count()+1;  // there will be a map shortly
2256 
2257   SafePointNode* map = start_map();
2258   if (!map->control()->is_Region())
2259     return pred_count()+1;  // there may be a region some day
2260   RegionNode* r = map->control()->as_Region();
2261 
2262   // Add new path to the region.
2263   uint pnum = r->req();
2264   r->add_req(nullptr);
2265 
2266   for (uint i = 1; i < map->req(); i++) {
2267     Node* n = map->in(i);
2268     if (i == TypeFunc::Memory) {
2269       // Ensure a phi on all currently known memories.
2270       for (MergeMemStream mms(n->as_MergeMem()); mms.next_non_empty(); ) {
2271         Node* phi = mms.memory();
2272         if (phi->is_Phi() && phi->as_Phi()->region() == r) {
2273           assert(phi->req() == pnum, "must be same size as region");
2274           phi->add_req(nullptr);
2275         }
2276       }
2277     } else {
2278       if (n->is_Phi() && n->as_Phi()->region() == r) {
2279         assert(n->req() == pnum, "must be same size as region");
2280         n->add_req(nullptr);
2281       } else if (n->is_InlineType() && n->as_InlineType()->has_phi_inputs(r)) {
2282         n->as_InlineType()->add_new_path(r);
2283       }
2284     }
2285   }
2286 
2287   return pnum;
2288 }
2289 
2290 //------------------------------ensure_phi-------------------------------------
2291 // Turn the idx'th entry of the current map into a Phi
2292 Node* Parse::ensure_phi(int idx, bool nocreate) {
2293   SafePointNode* map = this->map();
2294   Node* region = map->control();
2295   assert(region->is_Region(), "");
2296 
2297   Node* o = map->in(idx);
2298   assert(o != nullptr, "");
2299 
2300   if (o == top())  return nullptr; // TOP always merges into TOP
2301 
2302   if (o->is_Phi() && o->as_Phi()->region() == region) {
2303     return o->as_Phi();
2304   }
2305   InlineTypeNode* vt = o->isa_InlineType();
2306   if (vt != nullptr && vt->has_phi_inputs(region)) {
2307     return vt;
2308   }
2309 
2310   // Now use a Phi here for merging
2311   assert(!nocreate, "Cannot build a phi for a block already parsed.");
2312   const JVMState* jvms = map->jvms();
2313   const Type* t = nullptr;
2314   if (jvms->is_loc(idx)) {
2315     t = block()->local_type_at(idx - jvms->locoff());
2316   } else if (jvms->is_stk(idx)) {
2317     t = block()->stack_type_at(idx - jvms->stkoff());
2318   } else if (jvms->is_mon(idx)) {
2319     assert(!jvms->is_monitor_box(idx), "no phis for boxes");
2320     t = TypeInstPtr::BOTTOM; // this is sufficient for a lock object
2321   } else if ((uint)idx < TypeFunc::Parms) {
2322     t = o->bottom_type();  // Type::RETURN_ADDRESS or such-like.
2323   } else {
2324     assert(false, "no type information for this phi");
2325   }
2326 
2327   // If the type falls to bottom, then this must be a local that
2328   // is already dead or is mixing ints and oops or some such.
2329   // Forcing it to top makes it go dead.
2330   if (t == Type::BOTTOM) {
2331     map->set_req(idx, top());
2332     return nullptr;
2333   }
2334 
2335   // Do not create phis for top either.
2336   // A top on a non-null control flow must be an unused even after the.phi.
2337   if (t == Type::TOP || t == Type::HALF) {
2338     map->set_req(idx, top());
2339     return nullptr;
2340   }
2341 
2342   if (vt != nullptr && t->is_inlinetypeptr()) {
2343     // Inline types are merged by merging their field values.
2344     // Create a cloned InlineTypeNode with phi inputs that
2345     // represents the merged inline type and update the map.
2346     vt = vt->clone_with_phis(&_gvn, region);
2347     map->set_req(idx, vt);
2348     return vt;
2349   } else {
2350     PhiNode* phi = PhiNode::make(region, o, t);
2351     gvn().set_type(phi, t);
2352     if (C->do_escape_analysis()) record_for_igvn(phi);
2353     map->set_req(idx, phi);
2354     return phi;
2355   }
2356 }
2357 
2358 //--------------------------ensure_memory_phi----------------------------------
2359 // Turn the idx'th slice of the current memory into a Phi
2360 PhiNode *Parse::ensure_memory_phi(int idx, bool nocreate) {
2361   MergeMemNode* mem = merged_memory();
2362   Node* region = control();
2363   assert(region->is_Region(), "");
2364 
2365   Node *o = (idx == Compile::AliasIdxBot)? mem->base_memory(): mem->memory_at(idx);
2366   assert(o != nullptr && o != top(), "");
2367 
2368   PhiNode* phi;
2369   if (o->is_Phi() && o->as_Phi()->region() == region) {
2370     phi = o->as_Phi();
2371     if (phi == mem->base_memory() && idx >= Compile::AliasIdxRaw) {
2372       // clone the shared base memory phi to make a new memory split
2373       assert(!nocreate, "Cannot build a phi for a block already parsed.");
2374       const Type* t = phi->bottom_type();
2375       const TypePtr* adr_type = C->get_adr_type(idx);
2376       phi = phi->slice_memory(adr_type);
2377       gvn().set_type(phi, t);
2378     }
2379     return phi;
2380   }
2381 
2382   // Now use a Phi here for merging
2383   assert(!nocreate, "Cannot build a phi for a block already parsed.");
2384   const Type* t = o->bottom_type();
2385   const TypePtr* adr_type = C->get_adr_type(idx);
2386   phi = PhiNode::make(region, o, t, adr_type);
2387   gvn().set_type(phi, t);
2388   if (idx == Compile::AliasIdxBot)
2389     mem->set_base_memory(phi);
2390   else
2391     mem->set_memory_at(idx, phi);
2392   return phi;
2393 }
2394 
2395 //------------------------------call_register_finalizer-----------------------
2396 // Check the klass of the receiver and call register_finalizer if the
2397 // class need finalization.
2398 void Parse::call_register_finalizer() {
2399   Node* receiver = local(0);
2400   assert(receiver != nullptr && receiver->bottom_type()->isa_instptr() != nullptr,
2401          "must have non-null instance type");
2402 
2403   const TypeInstPtr *tinst = receiver->bottom_type()->isa_instptr();
2404   if (tinst != nullptr && tinst->is_loaded() && !tinst->klass_is_exact()) {
2405     // The type isn't known exactly so see if CHA tells us anything.
2406     ciInstanceKlass* ik = tinst->instance_klass();
2407     if (!Dependencies::has_finalizable_subclass(ik)) {
2408       // No finalizable subclasses so skip the dynamic check.
2409       C->dependencies()->assert_has_no_finalizable_subclasses(ik);
2410       return;
2411     }
2412   }
2413 
2414   // Insert a dynamic test for whether the instance needs
2415   // finalization.  In general this will fold up since the concrete
2416   // class is often visible so the access flags are constant.
2417   Node* klass_addr = basic_plus_adr( receiver, receiver, oopDesc::klass_offset_in_bytes() );
2418   Node* klass = _gvn.transform(LoadKlassNode::make(_gvn, immutable_memory(), klass_addr, TypeInstPtr::KLASS));
2419 
2420   Node* access_flags_addr = off_heap_plus_addr(klass, in_bytes(Klass::misc_flags_offset()));
2421   Node* access_flags = make_load(nullptr, access_flags_addr, TypeInt::UBYTE, T_BOOLEAN, MemNode::unordered);
2422 
2423   Node* mask  = _gvn.transform(new AndINode(access_flags, intcon(KlassFlags::_misc_has_finalizer)));
2424   Node* check = _gvn.transform(new CmpINode(mask, intcon(0)));
2425   Node* test  = _gvn.transform(new BoolNode(check, BoolTest::ne));
2426 
2427   IfNode* iff = create_and_map_if(control(), test, PROB_MAX, COUNT_UNKNOWN);
2428 
2429   RegionNode* result_rgn = new RegionNode(3);
2430   record_for_igvn(result_rgn);
2431 
2432   Node *skip_register = _gvn.transform(new IfFalseNode(iff));
2433   result_rgn->init_req(1, skip_register);
2434 
2435   Node *needs_register = _gvn.transform(new IfTrueNode(iff));
2436   set_control(needs_register);
2437   if (stopped()) {
2438     // There is no slow path.
2439     result_rgn->init_req(2, top());
2440   } else {
2441     Node *call = make_runtime_call(RC_NO_LEAF,
2442                                    OptoRuntime::register_finalizer_Type(),
2443                                    OptoRuntime::register_finalizer_Java(),
2444                                    nullptr, TypePtr::BOTTOM,
2445                                    receiver);
2446     make_slow_call_ex(call, env()->Throwable_klass(), true);
2447 
2448     Node* fast_io  = call->in(TypeFunc::I_O);
2449     Node* fast_mem = call->in(TypeFunc::Memory);
2450     // These two phis are pre-filled with copies of of the fast IO and Memory
2451     Node* io_phi   = PhiNode::make(result_rgn, fast_io,  Type::ABIO);
2452     Node* mem_phi  = PhiNode::make(result_rgn, fast_mem, Type::MEMORY, TypePtr::BOTTOM);
2453 
2454     result_rgn->init_req(2, control());
2455     io_phi    ->init_req(2, i_o());
2456     mem_phi   ->init_req(2, reset_memory());
2457 
2458     set_all_memory( _gvn.transform(mem_phi) );
2459     set_i_o(        _gvn.transform(io_phi) );
2460   }
2461 
2462   set_control( _gvn.transform(result_rgn) );
2463 }
2464 
2465 // Add check to deoptimize once holder klass is fully initialized.
2466 void Parse::clinit_deopt() {
2467   assert(C->has_method(), "only for normal compilations");
2468   assert(depth() == 1, "only for main compiled method");
2469   assert(is_normal_parse(), "no barrier needed on osr entry");
2470   assert(!method()->holder()->is_not_initialized(), "initialization should have been started");
2471 
2472   set_parse_bci(0);
2473 
2474   Node* holder = makecon(TypeKlassPtr::make(method()->holder(), Type::trust_interfaces));
2475   guard_klass_being_initialized(holder);
2476 }
2477 
2478 //------------------------------return_current---------------------------------
2479 // Append current _map to _exit_return
2480 void Parse::return_current(Node* value) {
2481   if (method()->intrinsic_id() == vmIntrinsics::_Object_init) {
2482     call_register_finalizer();
2483   }
2484 
2485   // frame pointer is always same, already captured
2486   if (value != nullptr) {
2487     Node* phi = _exits.argument(0);
2488     const Type* return_type = phi->bottom_type();
2489     if ((tf()->returns_inline_type_as_fields() || (_caller->has_method() && !Compile::current()->inlining_incrementally())) &&
2490         return_type->is_inlinetypeptr()) {
2491       // Inline type is returned as fields, make sure it is scalarized
2492       if (!value->is_InlineType()) {
2493         value = InlineTypeNode::make_from_oop(this, value, return_type->inline_klass());
2494       }
2495       if (!_caller->has_method() || Compile::current()->inlining_incrementally()) {
2496         // Returning from root or an incrementally inlined method. Make sure all non-flat
2497         // fields are buffered and re-execute if allocation triggers deoptimization.
2498         PreserveReexecuteState preexecs(this);
2499         assert(tf()->returns_inline_type_as_fields(), "must be returned as fields");
2500         jvms()->set_should_reexecute(true);
2501         inc_sp(1);
2502         value = value->as_InlineType()->allocate_fields(this);
2503       }
2504     } else if (value->is_InlineType()) {
2505       // Inline type is returned as oop, make sure it is buffered and re-execute
2506       // if allocation triggers deoptimization.
2507       PreserveReexecuteState preexecs(this);
2508       jvms()->set_should_reexecute(true);
2509       inc_sp(1);
2510       value = value->as_InlineType()->buffer(this);
2511     }
2512     // ...else
2513     // If returning oops to an interface-return, there is a silent free
2514     // cast from oop to interface allowed by the Verifier. Make it explicit here.
2515     phi->add_req(value);
2516   }
2517 
2518   if (StressReachabilityFences) {
2519     // Insert reachability fences for all oop arguments at the end of the method.
2520     for (uint i = 1; i < _stress_rf_hook->req(); i++) {
2521       Node* referent = _stress_rf_hook->in(i);
2522       assert(referent->bottom_type()->isa_oopptr(), "%s", Type::str(referent->bottom_type()));
2523       insert_reachability_fence(referent);
2524     }
2525   }
2526 
2527   // Do not set_parse_bci, so that return goo is credited to the return insn.
2528   set_bci(InvocationEntryBci);
2529   if (method()->is_synchronized()) {
2530     shared_unlock(_synch_lock->box_node(), _synch_lock->obj_node());
2531   }
2532   if (C->env()->dtrace_method_probes()) {
2533     make_dtrace_method_exit(method());
2534   }
2535 
2536   SafePointNode* exit_return = _exits.map();
2537   exit_return->in( TypeFunc::Control  )->add_req( control() );
2538   exit_return->in( TypeFunc::I_O      )->add_req( i_o    () );
2539   Node *mem = exit_return->in( TypeFunc::Memory   );
2540   for (MergeMemStream mms(mem->as_MergeMem(), merged_memory()); mms.next_non_empty2(); ) {
2541     if (mms.is_empty()) {
2542       // get a copy of the base memory, and patch just this one input
2543       const TypePtr* adr_type = mms.adr_type(C);
2544       Node* phi = mms.force_memory()->as_Phi()->slice_memory(adr_type);
2545       assert(phi->as_Phi()->region() == mms.base_memory()->in(0), "");
2546       gvn().set_type_bottom(phi);
2547       phi->del_req(phi->req()-1);  // prepare to re-patch
2548       mms.set_memory(phi);
2549     }
2550     mms.memory()->add_req(mms.memory2());
2551   }
2552 
2553   if (_first_return) {
2554     _exits.map()->transfer_replaced_nodes_from(map(), _new_idx);
2555     _first_return = false;
2556   } else {
2557     _exits.map()->merge_replaced_nodes_with(map());
2558   }
2559 
2560   stop_and_kill_map();          // This CFG path dies here
2561 }
2562 
2563 
2564 //------------------------------add_safepoint----------------------------------
2565 void Parse::add_safepoint() {
2566   uint parms = TypeFunc::Parms+1;
2567 
2568   // Clear out dead values from the debug info.
2569   kill_dead_locals();
2570 
2571   // Clone the JVM State
2572   SafePointNode *sfpnt = new SafePointNode(parms, nullptr);
2573 
2574   // Capture memory state BEFORE a SafePoint.  Since we can block at a
2575   // SafePoint we need our GC state to be safe; i.e. we need all our current
2576   // write barriers (card marks) to not float down after the SafePoint so we
2577   // must read raw memory.  Likewise we need all oop stores to match the card
2578   // marks.  If deopt can happen, we need ALL stores (we need the correct JVM
2579   // state on a deopt).
2580 
2581   // We do not need to WRITE the memory state after a SafePoint.  The control
2582   // edge will keep card-marks and oop-stores from floating up from below a
2583   // SafePoint and our true dependency added here will keep them from floating
2584   // down below a SafePoint.
2585 
2586   // Clone the current memory state
2587   Node* mem = MergeMemNode::make(map()->memory());
2588 
2589   mem = _gvn.transform(mem);
2590 
2591   // Pass control through the safepoint
2592   sfpnt->init_req(TypeFunc::Control  , control());
2593   // Fix edges normally used by a call
2594   sfpnt->init_req(TypeFunc::I_O      , top() );
2595   sfpnt->init_req(TypeFunc::Memory   , mem   );
2596   sfpnt->init_req(TypeFunc::ReturnAdr, top() );
2597   sfpnt->init_req(TypeFunc::FramePtr , top() );
2598 
2599   // Create a node for the polling address
2600   Node* polladr;
2601   Node* thread = _gvn.transform(new ThreadLocalNode());
2602   Node* polling_page_load_addr = _gvn.transform(off_heap_plus_addr(thread, in_bytes(JavaThread::polling_page_offset())));
2603   polladr = make_load(control(), polling_page_load_addr, TypeRawPtr::BOTTOM, T_ADDRESS, MemNode::unordered);
2604   sfpnt->init_req(TypeFunc::Parms+0, _gvn.transform(polladr));
2605 
2606   // Fix up the JVM State edges
2607   add_safepoint_edges(sfpnt);
2608   Node *transformed_sfpnt = _gvn.transform(sfpnt);
2609   set_control(transformed_sfpnt);
2610 
2611   // Provide an edge from root to safepoint.  This makes the safepoint
2612   // appear useful until the parse has completed.
2613   if (transformed_sfpnt->is_SafePoint()) {
2614     assert(C->root() != nullptr, "Expect parse is still valid");
2615     C->root()->add_prec(transformed_sfpnt);
2616   }
2617 }
2618 
2619 #ifndef PRODUCT
2620 //------------------------show_parse_info--------------------------------------
2621 void Parse::show_parse_info() {
2622   InlineTree* ilt = nullptr;
2623   if (C->ilt() != nullptr) {
2624     JVMState* caller_jvms = is_osr_parse() ? caller()->caller() : caller();
2625     ilt = InlineTree::find_subtree_from_root(C->ilt(), caller_jvms, method());
2626   }
2627   if (PrintCompilation && Verbose) {
2628     if (depth() == 1) {
2629       if( ilt->count_inlines() ) {
2630         tty->print("    __inlined %d (%d bytes)", ilt->count_inlines(),
2631                      ilt->count_inline_bcs());
2632         tty->cr();
2633       }
2634     } else {
2635       if (method()->is_synchronized())         tty->print("s");
2636       if (method()->has_exception_handlers())  tty->print("!");
2637       // Check this is not the final compiled version
2638       if (C->trap_can_recompile()) {
2639         tty->print("-");
2640       } else {
2641         tty->print(" ");
2642       }
2643       method()->print_short_name();
2644       if (is_osr_parse()) {
2645         tty->print(" @ %d", osr_bci());
2646       }
2647       tty->print(" (%d bytes)",method()->code_size());
2648       if (ilt->count_inlines()) {
2649         tty->print(" __inlined %d (%d bytes)", ilt->count_inlines(),
2650                    ilt->count_inline_bcs());
2651       }
2652       tty->cr();
2653     }
2654   }
2655   if (PrintOpto && (depth() == 1 || PrintOptoInlining)) {
2656     // Print that we succeeded; suppress this message on the first osr parse.
2657 
2658     if (method()->is_synchronized())         tty->print("s");
2659     if (method()->has_exception_handlers())  tty->print("!");
2660     // Check this is not the final compiled version
2661     if (C->trap_can_recompile() && depth() == 1) {
2662       tty->print("-");
2663     } else {
2664       tty->print(" ");
2665     }
2666     if( depth() != 1 ) { tty->print("   "); }  // missing compile count
2667     for (int i = 1; i < depth(); ++i) { tty->print("  "); }
2668     method()->print_short_name();
2669     if (is_osr_parse()) {
2670       tty->print(" @ %d", osr_bci());
2671     }
2672     if (ilt->caller_bci() != -1) {
2673       tty->print(" @ %d", ilt->caller_bci());
2674     }
2675     tty->print(" (%d bytes)",method()->code_size());
2676     if (ilt->count_inlines()) {
2677       tty->print(" __inlined %d (%d bytes)", ilt->count_inlines(),
2678                  ilt->count_inline_bcs());
2679     }
2680     tty->cr();
2681   }
2682 }
2683 
2684 
2685 //------------------------------dump-------------------------------------------
2686 // Dump information associated with the bytecodes of current _method
2687 void Parse::dump() {
2688   if( method() != nullptr ) {
2689     // Iterate over bytecodes
2690     ciBytecodeStream iter(method());
2691     for( Bytecodes::Code bc = iter.next(); bc != ciBytecodeStream::EOBC() ; bc = iter.next() ) {
2692       dump_bci( iter.cur_bci() );
2693       tty->cr();
2694     }
2695   }
2696 }
2697 
2698 // Dump information associated with a byte code index, 'bci'
2699 void Parse::dump_bci(int bci) {
2700   // Output info on merge-points, cloning, and within _jsr..._ret
2701   // NYI
2702   tty->print(" bci:%d", bci);
2703 }
2704 
2705 #endif