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src/hotspot/share/opto/parse1.cpp

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  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "compiler/compileLog.hpp"
  26 #include "interpreter/linkResolver.hpp"
  27 #include "memory/resourceArea.hpp"
  28 #include "oops/method.hpp"
  29 #include "opto/addnode.hpp"
  30 #include "opto/c2compiler.hpp"
  31 #include "opto/castnode.hpp"

  32 #include "opto/idealGraphPrinter.hpp"

  33 #include "opto/locknode.hpp"
  34 #include "opto/memnode.hpp"
  35 #include "opto/opaquenode.hpp"
  36 #include "opto/parse.hpp"
  37 #include "opto/rootnode.hpp"
  38 #include "opto/runtime.hpp"
  39 #include "opto/type.hpp"
  40 #include "runtime/handles.inline.hpp"
  41 #include "runtime/safepointMechanism.hpp"
  42 #include "runtime/sharedRuntime.hpp"
  43 #include "utilities/bitMap.inline.hpp"
  44 #include "utilities/copy.hpp"
  45 
  46 // Static array so we can figure out which bytecodes stop us from compiling
  47 // the most. Some of the non-static variables are needed in bytecodeInfo.cpp
  48 // and eventually should be encapsulated in a proper class (gri 8/18/98).
  49 
  50 #ifndef PRODUCT
  51 uint nodes_created             = 0;
  52 uint methods_parsed            = 0;

  84   }
  85   if (all_null_checks_found) {
  86     tty->print_cr("%u made implicit (%2u%%)", implicit_null_checks,
  87                   (100*implicit_null_checks)/all_null_checks_found);
  88   }
  89   if (SharedRuntime::_implicit_null_throws) {
  90     tty->print_cr("%u implicit null exceptions at runtime",
  91                   SharedRuntime::_implicit_null_throws);
  92   }
  93 
  94   if (PrintParseStatistics && BytecodeParseHistogram::initialized()) {
  95     BytecodeParseHistogram::print();
  96   }
  97 }
  98 #endif
  99 
 100 //------------------------------ON STACK REPLACEMENT---------------------------
 101 
 102 // Construct a node which can be used to get incoming state for
 103 // on stack replacement.
 104 Node *Parse::fetch_interpreter_state(int index,
 105                                      BasicType bt,
 106                                      Node *local_addrs,
 107                                      Node *local_addrs_base) {






 108   Node *mem = memory(Compile::AliasIdxRaw);
 109   Node *adr = basic_plus_adr( local_addrs_base, local_addrs, -index*wordSize );
 110   Node *ctl = control();
 111 
 112   // Very similar to LoadNode::make, except we handle un-aligned longs and
 113   // doubles on Sparc.  Intel can handle them just fine directly.
 114   Node *l = nullptr;
 115   switch (bt) {                // Signature is flattened
 116   case T_INT:     l = new LoadINode(ctl, mem, adr, TypeRawPtr::BOTTOM, TypeInt::INT,        MemNode::unordered); break;
 117   case T_FLOAT:   l = new LoadFNode(ctl, mem, adr, TypeRawPtr::BOTTOM, Type::FLOAT,         MemNode::unordered); break;
 118   case T_ADDRESS: l = new LoadPNode(ctl, mem, adr, TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM,  MemNode::unordered); break;
 119   case T_OBJECT:  l = new LoadPNode(ctl, mem, adr, TypeRawPtr::BOTTOM, TypeInstPtr::BOTTOM, MemNode::unordered); break;
 120   case T_LONG:
 121   case T_DOUBLE: {
 122     // Since arguments are in reverse order, the argument address 'adr'
 123     // refers to the back half of the long/double.  Recompute adr.
 124     adr = basic_plus_adr(local_addrs_base, local_addrs, -(index+1)*wordSize);
 125     if (Matcher::misaligned_doubles_ok) {
 126       l = (bt == T_DOUBLE)
 127         ? (Node*)new LoadDNode(ctl, mem, adr, TypeRawPtr::BOTTOM, Type::DOUBLE, MemNode::unordered)
 128         : (Node*)new LoadLNode(ctl, mem, adr, TypeRawPtr::BOTTOM, TypeLong::LONG, MemNode::unordered);
 129     } else {
 130       l = (bt == T_DOUBLE)
 131         ? (Node*)new LoadD_unalignedNode(ctl, mem, adr, TypeRawPtr::BOTTOM, MemNode::unordered)
 132         : (Node*)new LoadL_unalignedNode(ctl, mem, adr, TypeRawPtr::BOTTOM, MemNode::unordered);
 133     }
 134     break;
 135   }
 136   default: ShouldNotReachHere();
 137   }
 138   return _gvn.transform(l);
 139 }
 140 
 141 // Helper routine to prevent the interpreter from handing
 142 // unexpected typestate to an OSR method.
 143 // The Node l is a value newly dug out of the interpreter frame.
 144 // The type is the type predicted by ciTypeFlow.  Note that it is
 145 // not a general type, but can only come from Type::get_typeflow_type.
 146 // The safepoint is a map which will feed an uncommon trap.
 147 Node* Parse::check_interpreter_type(Node* l, const Type* type,
 148                                     SafePointNode* &bad_type_exit) {
 149 
 150   const TypeOopPtr* tp = type->isa_oopptr();
 151 
 152   // TypeFlow may assert null-ness if a type appears unloaded.
 153   if (type == TypePtr::NULL_PTR ||
 154       (tp != nullptr && !tp->is_loaded())) {
 155     // Value must be null, not a real oop.
 156     Node* chk = _gvn.transform( new CmpPNode(l, null()) );
 157     Node* tst = _gvn.transform( new BoolNode(chk, BoolTest::eq) );
 158     IfNode* iff = create_and_map_if(control(), tst, PROB_MAX, COUNT_UNKNOWN);
 159     set_control(_gvn.transform( new IfTrueNode(iff) ));
 160     Node* bad_type = _gvn.transform( new IfFalseNode(iff) );
 161     bad_type_exit->control()->add_req(bad_type);
 162     l = null();
 163   }
 164 
 165   // Typeflow can also cut off paths from the CFG, based on
 166   // types which appear unloaded, or call sites which appear unlinked.
 167   // When paths are cut off, values at later merge points can rise
 168   // toward more specific classes.  Make sure these specific classes
 169   // are still in effect.
 170   if (tp != nullptr && !tp->is_same_java_type_as(TypeInstPtr::BOTTOM)) {
 171     // TypeFlow asserted a specific object type.  Value must have that type.
 172     Node* bad_type_ctrl = nullptr;
 173     l = gen_checkcast(l, makecon(tp->as_klass_type()->cast_to_exactness(true)), &bad_type_ctrl);







 174     bad_type_exit->control()->add_req(bad_type_ctrl);
 175   }
 176 
 177   assert(_gvn.type(l)->higher_equal(type), "must constrain OSR typestate");
 178   return l;
 179 }
 180 
 181 // Helper routine which sets up elements of the initial parser map when
 182 // performing a parse for on stack replacement.  Add values into map.
 183 // The only parameter contains the address of a interpreter arguments.
 184 void Parse::load_interpreter_state(Node* osr_buf) {
 185   int index;
 186   int max_locals = jvms()->loc_size();
 187   int max_stack  = jvms()->stk_size();
 188 
 189 
 190   // Mismatch between method and jvms can occur since map briefly held
 191   // an OSR entry state (which takes up one RawPtr word).
 192   assert(max_locals == method()->max_locals(), "sanity");
 193   assert(max_stack  >= method()->max_stack(),  "sanity");
 194   assert((int)jvms()->endoff() == TypeFunc::Parms + max_locals + max_stack, "sanity");
 195   assert((int)jvms()->endoff() == (int)map()->req(), "sanity");
 196 
 197   // Find the start block.
 198   Block* osr_block = start_block();
 199   assert(osr_block->start() == osr_bci(), "sanity");
 200 
 201   // Set initial BCI.
 202   set_parse_bci(osr_block->start());
 203 
 204   // Set initial stack depth.
 205   set_sp(osr_block->start_sp());
 206 
 207   // Check bailouts.  We currently do not perform on stack replacement
 208   // of loops in catch blocks or loops which branch with a non-empty stack.
 209   if (sp() != 0) {

 224   for (index = 0; index < mcnt; index++) {
 225     // Make a BoxLockNode for the monitor.
 226     BoxLockNode* osr_box = new BoxLockNode(next_monitor());
 227     // Check for bailout after new BoxLockNode
 228     if (failing()) { return; }
 229 
 230     // This OSR locking region is unbalanced because it does not have Lock node:
 231     // locking was done in Interpreter.
 232     // This is similar to Coarsened case when Lock node is eliminated
 233     // and as result the region is marked as Unbalanced.
 234 
 235     // Emulate Coarsened state transition from Regular to Unbalanced.
 236     osr_box->set_coarsened();
 237     osr_box->set_unbalanced();
 238 
 239     Node* box = _gvn.transform(osr_box);
 240 
 241     // Displaced headers and locked objects are interleaved in the
 242     // temp OSR buffer.  We only copy the locked objects out here.
 243     // Fetch the locked object from the OSR temp buffer and copy to our fastlock node.
 244     Node *lock_object = fetch_interpreter_state(index*2, T_OBJECT, monitors_addr, osr_buf);
 245     // Try and copy the displaced header to the BoxNode
 246     Node *displaced_hdr = fetch_interpreter_state((index*2) + 1, T_ADDRESS, monitors_addr, osr_buf);
 247 
 248 
 249     store_to_memory(control(), box, displaced_hdr, T_ADDRESS, MemNode::unordered);
 250 
 251     // Build a bogus FastLockNode (no code will be generated) and push the
 252     // monitor into our debug info.
 253     const FastLockNode *flock = _gvn.transform(new FastLockNode( nullptr, lock_object, box ))->as_FastLock();
 254     map()->push_monitor(flock);
 255 
 256     // If the lock is our method synchronization lock, tuck it away in
 257     // _sync_lock for return and rethrow exit paths.
 258     if (index == 0 && method()->is_synchronized()) {
 259       _synch_lock = flock;
 260     }
 261   }
 262 
 263   // Use the raw liveness computation to make sure that unexpected
 264   // values don't propagate into the OSR frame.
 265   MethodLivenessResult live_locals = method()->liveness_at_bci(osr_bci());
 266   if (!live_locals.is_valid()) {
 267     // Degenerate or breakpointed method.

 295         if (C->log() != nullptr) {
 296           C->log()->elem("OSR_mismatch local_index='%d'",index);
 297         }
 298         set_local(index, null());
 299         // and ignore it for the loads
 300         continue;
 301       }
 302     }
 303 
 304     // Filter out TOP, HALF, and BOTTOM.  (Cf. ensure_phi.)
 305     if (type == Type::TOP || type == Type::HALF) {
 306       continue;
 307     }
 308     // If the type falls to bottom, then this must be a local that
 309     // is mixing ints and oops or some such.  Forcing it to top
 310     // makes it go dead.
 311     if (type == Type::BOTTOM) {
 312       continue;
 313     }
 314     // Construct code to access the appropriate local.
 315     BasicType bt = type->basic_type();
 316     if (type == TypePtr::NULL_PTR) {
 317       // Ptr types are mixed together with T_ADDRESS but null is
 318       // really for T_OBJECT types so correct it.
 319       bt = T_OBJECT;
 320     }
 321     Node *value = fetch_interpreter_state(index, bt, locals_addr, osr_buf);
 322     set_local(index, value);
 323   }
 324 
 325   // Extract the needed stack entries from the interpreter frame.
 326   for (index = 0; index < sp(); index++) {
 327     const Type *type = osr_block->stack_type_at(index);
 328     if (type != Type::TOP) {
 329       // Currently the compiler bails out when attempting to on stack replace
 330       // at a bci with a non-empty stack.  We should not reach here.
 331       ShouldNotReachHere();
 332     }
 333   }
 334 
 335   // End the OSR migration
 336   make_runtime_call(RC_LEAF, OptoRuntime::osr_end_Type(),
 337                     CAST_FROM_FN_PTR(address, SharedRuntime::OSR_migration_end),
 338                     "OSR_migration_end", TypeRawPtr::BOTTOM,
 339                     osr_buf);
 340 
 341   // Now that the interpreter state is loaded, make sure it will match

 352     if (type->isa_oopptr() != nullptr) {
 353       if (!live_oops.at(index)) {
 354         // skip type check for dead oops
 355         continue;
 356       }
 357     }
 358     if (osr_block->flow()->local_type_at(index)->is_return_address()) {
 359       // In our current system it's illegal for jsr addresses to be
 360       // live into an OSR entry point because the compiler performs
 361       // inlining of jsrs.  ciTypeFlow has a bailout that detect this
 362       // case and aborts the compile if addresses are live into an OSR
 363       // entry point.  Because of that we can assume that any address
 364       // locals at the OSR entry point are dead.  Method liveness
 365       // isn't precise enough to figure out that they are dead in all
 366       // cases so simply skip checking address locals all
 367       // together. Any type check is guaranteed to fail since the
 368       // interpreter type is the result of a load which might have any
 369       // value and the expected type is a constant.
 370       continue;
 371     }
 372     set_local(index, check_interpreter_type(l, type, bad_type_exit));

 373   }
 374 
 375   for (index = 0; index < sp(); index++) {
 376     if (stopped())  break;
 377     Node* l = stack(index);
 378     if (l->is_top())  continue;  // nothing here
 379     const Type *type = osr_block->stack_type_at(index);
 380     set_stack(index, check_interpreter_type(l, type, bad_type_exit));

 381   }
 382 
 383   if (bad_type_exit->control()->req() > 1) {
 384     // Build an uncommon trap here, if any inputs can be unexpected.
 385     bad_type_exit->set_control(_gvn.transform( bad_type_exit->control() ));
 386     record_for_igvn(bad_type_exit->control());
 387     SafePointNode* types_are_good = map();
 388     set_map(bad_type_exit);
 389     // The unexpected type happens because a new edge is active
 390     // in the CFG, which typeflow had previously ignored.
 391     // E.g., Object x = coldAtFirst() && notReached()? "str": new Integer(123).
 392     // This x will be typed as Integer if notReached is not yet linked.
 393     // It could also happen due to a problem in ciTypeFlow analysis.
 394     uncommon_trap(Deoptimization::Reason_constraint,
 395                   Deoptimization::Action_reinterpret);
 396     set_map(types_are_good);
 397   }
 398 }
 399 
 400 //------------------------------Parse------------------------------------------

 501   // either breakpoint setting or hotswapping of methods may
 502   // cause deoptimization.
 503   if (C->env()->jvmti_can_hotswap_or_post_breakpoint()) {
 504     C->dependencies()->assert_evol_method(method());
 505   }
 506 
 507   NOT_PRODUCT(methods_seen++);
 508 
 509   // Do some special top-level things.
 510   if (depth() == 1 && C->is_osr_compilation()) {
 511     _tf = C->tf();     // the OSR entry type is different
 512     _entry_bci = C->entry_bci();
 513     _flow = method()->get_osr_flow_analysis(osr_bci());
 514   } else {
 515     _tf = TypeFunc::make(method());
 516     _entry_bci = InvocationEntryBci;
 517     _flow = method()->get_flow_analysis();
 518   }
 519 
 520   if (_flow->failing()) {
 521     assert(false, "type flow analysis failed during parsing");


 522     C->record_method_not_compilable(_flow->failure_reason());
 523 #ifndef PRODUCT
 524       if (PrintOpto && (Verbose || WizardMode)) {
 525         if (is_osr_parse()) {
 526           tty->print_cr("OSR @%d type flow bailout: %s", _entry_bci, _flow->failure_reason());
 527         } else {
 528           tty->print_cr("type flow bailout: %s", _flow->failure_reason());
 529         }
 530         if (Verbose) {
 531           method()->print();
 532           method()->print_codes();
 533           _flow->print();
 534         }
 535       }
 536 #endif
 537   }
 538 
 539 #ifdef ASSERT
 540   if (depth() == 1) {
 541     assert(C->is_osr_compilation() == this->is_osr_parse(), "OSR in sync");

 592     load_interpreter_state(osr_buf);
 593   } else {
 594     set_map(entry_map);
 595     do_method_entry();
 596   }
 597 
 598   if (depth() == 1 && !failing()) {
 599     if (C->clinit_barrier_on_entry()) {
 600       // Add check to deoptimize the nmethod once the holder class is fully initialized
 601       clinit_deopt();
 602     }
 603   }
 604 
 605   // Check for bailouts during method entry.
 606   if (failing()) {
 607     if (log)  log->done("parse");
 608     C->set_default_node_notes(caller_nn);
 609     return;
 610   }
 611 


























 612   entry_map = map();  // capture any changes performed by method setup code
 613   assert(jvms()->endoff() == map()->req(), "map matches JVMS layout");
 614 
 615   // We begin parsing as if we have just encountered a jump to the
 616   // method entry.
 617   Block* entry_block = start_block();
 618   assert(entry_block->start() == (is_osr_parse() ? osr_bci() : 0), "");
 619   set_map_clone(entry_map);
 620   merge_common(entry_block, entry_block->next_path_num());
 621 
 622 #ifndef PRODUCT
 623   BytecodeParseHistogram *parse_histogram_obj = new (C->env()->arena()) BytecodeParseHistogram(this, C);
 624   set_parse_histogram( parse_histogram_obj );
 625 #endif
 626 
 627   // Parse all the basic blocks.
 628   do_all_blocks();
 629 
 630   // Check for bailouts during conversion to graph
 631   if (failing()) {

 777 void Parse::build_exits() {
 778   // make a clone of caller to prevent sharing of side-effects
 779   _exits.set_map(_exits.clone_map());
 780   _exits.clean_stack(_exits.sp());
 781   _exits.sync_jvms();
 782 
 783   RegionNode* region = new RegionNode(1);
 784   record_for_igvn(region);
 785   gvn().set_type_bottom(region);
 786   _exits.set_control(region);
 787 
 788   // Note:  iophi and memphi are not transformed until do_exits.
 789   Node* iophi  = new PhiNode(region, Type::ABIO);
 790   Node* memphi = new PhiNode(region, Type::MEMORY, TypePtr::BOTTOM);
 791   gvn().set_type_bottom(iophi);
 792   gvn().set_type_bottom(memphi);
 793   _exits.set_i_o(iophi);
 794   _exits.set_all_memory(memphi);
 795 
 796   // Add a return value to the exit state.  (Do not push it yet.)
 797   if (tf()->range()->cnt() > TypeFunc::Parms) {
 798     const Type* ret_type = tf()->range()->field_at(TypeFunc::Parms);
 799     if (ret_type->isa_int()) {
 800       BasicType ret_bt = method()->return_type()->basic_type();
 801       if (ret_bt == T_BOOLEAN ||
 802           ret_bt == T_CHAR ||
 803           ret_bt == T_BYTE ||
 804           ret_bt == T_SHORT) {
 805         ret_type = TypeInt::INT;
 806       }
 807     }
 808 
 809     // Don't "bind" an unloaded return klass to the ret_phi. If the klass
 810     // becomes loaded during the subsequent parsing, the loaded and unloaded
 811     // types will not join when we transform and push in do_exits().
 812     const TypeOopPtr* ret_oop_type = ret_type->isa_oopptr();
 813     if (ret_oop_type && !ret_oop_type->is_loaded()) {
 814       ret_type = TypeOopPtr::BOTTOM;
 815     }
 816     int         ret_size = type2size[ret_type->basic_type()];
 817     Node*       ret_phi  = new PhiNode(region, ret_type);
 818     gvn().set_type_bottom(ret_phi);
 819     _exits.ensure_stack(ret_size);
 820     assert((int)(tf()->range()->cnt() - TypeFunc::Parms) == ret_size, "good tf range");
 821     assert(method()->return_type()->size() == ret_size, "tf agrees w/ method");
 822     _exits.set_argument(0, ret_phi);  // here is where the parser finds it
 823     // Note:  ret_phi is not yet pushed, until do_exits.
 824   }
 825 }
 826 
 827 
 828 //----------------------------build_start_state-------------------------------
 829 // Construct a state which contains only the incoming arguments from an
 830 // unknown caller.  The method & bci will be null & InvocationEntryBci.
 831 JVMState* Compile::build_start_state(StartNode* start, const TypeFunc* tf) {
 832   int        arg_size = tf->domain()->cnt();
 833   int        max_size = MAX2(arg_size, (int)tf->range()->cnt());
 834   JVMState*  jvms     = new (this) JVMState(max_size - TypeFunc::Parms);
 835   SafePointNode* map  = new SafePointNode(max_size, jvms);

 836   record_for_igvn(map);
 837   assert(arg_size == TypeFunc::Parms + (is_osr_compilation() ? 1 : method()->arg_size()), "correct arg_size");
 838   Node_Notes* old_nn = default_node_notes();
 839   if (old_nn != nullptr && has_method()) {
 840     Node_Notes* entry_nn = old_nn->clone(this);
 841     JVMState* entry_jvms = new(this) JVMState(method(), old_nn->jvms());
 842     entry_jvms->set_offsets(0);
 843     entry_jvms->set_bci(entry_bci());
 844     entry_nn->set_jvms(entry_jvms);
 845     set_default_node_notes(entry_nn);
 846   }
 847   uint i;
 848   for (i = 0; i < (uint)arg_size; i++) {
 849     Node* parm = initial_gvn()->transform(new ParmNode(start, i));

















 850     map->init_req(i, parm);
 851     // Record all these guys for later GVN.
 852     record_for_igvn(parm);



 853   }
 854   for (; i < map->req(); i++) {
 855     map->init_req(i, top());
 856   }
 857   assert(jvms->argoff() == TypeFunc::Parms, "parser gets arguments here");
 858   set_default_node_notes(old_nn);
 859   jvms->set_map(map);
 860   return jvms;
 861 }
 862 
 863 //-----------------------------make_node_notes---------------------------------
 864 Node_Notes* Parse::make_node_notes(Node_Notes* caller_nn) {
 865   if (caller_nn == nullptr)  return nullptr;
 866   Node_Notes* nn = caller_nn->clone(C);
 867   JVMState* caller_jvms = nn->jvms();
 868   JVMState* jvms = new (C) JVMState(method(), caller_jvms);
 869   jvms->set_offsets(0);
 870   jvms->set_bci(_entry_bci);
 871   nn->set_jvms(jvms);
 872   return nn;
 873 }
 874 
 875 
 876 //--------------------------return_values--------------------------------------
 877 void Compile::return_values(JVMState* jvms) {
 878   GraphKit kit(jvms);
 879   Node* ret = new ReturnNode(TypeFunc::Parms,
 880                              kit.control(),
 881                              kit.i_o(),
 882                              kit.reset_memory(),
 883                              kit.frameptr(),
 884                              kit.returnadr());
 885   // Add zero or 1 return values
 886   int ret_size = tf()->range()->cnt() - TypeFunc::Parms;
 887   if (ret_size > 0) {
 888     kit.inc_sp(-ret_size);  // pop the return value(s)
 889     kit.sync_jvms();
 890     ret->add_req(kit.argument(0));
 891     // Note:  The second dummy edge is not needed by a ReturnNode.






















 892   }
 893   // bind it to root
 894   root()->add_req(ret);
 895   record_for_igvn(ret);
 896   initial_gvn()->transform(ret);
 897 }
 898 
 899 //------------------------rethrow_exceptions-----------------------------------
 900 // Bind all exception states in the list into a single RethrowNode.
 901 void Compile::rethrow_exceptions(JVMState* jvms) {
 902   GraphKit kit(jvms);
 903   if (!kit.has_exceptions())  return;  // nothing to generate
 904   // Load my combined exception state into the kit, with all phis transformed:
 905   SafePointNode* ex_map = kit.combine_and_pop_all_exception_states();
 906   Node* ex_oop = kit.use_exception_state(ex_map);
 907   RethrowNode* exit = new RethrowNode(kit.control(),
 908                                       kit.i_o(), kit.reset_memory(),
 909                                       kit.frameptr(), kit.returnadr(),
 910                                       // like a return but with exception input
 911                                       ex_oop);

 995   //    to complete, we force all writes to complete.
 996   //
 997   // 2. Experimental VM option is used to force the barrier if any field
 998   //    was written out in the constructor.
 999   //
1000   // 3. On processors which are not CPU_MULTI_COPY_ATOMIC (e.g. PPC64),
1001   //    support_IRIW_for_not_multiple_copy_atomic_cpu selects that
1002   //    MemBarVolatile is used before volatile load instead of after volatile
1003   //    store, so there's no barrier after the store.
1004   //    We want to guarantee the same behavior as on platforms with total store
1005   //    order, although this is not required by the Java memory model.
1006   //    In this case, we want to enforce visibility of volatile field
1007   //    initializations which are performed in constructors.
1008   //    So as with finals, we add a barrier here.
1009   //
1010   // "All bets are off" unless the first publication occurs after a
1011   // normal return from the constructor.  We do not attempt to detect
1012   // such unusual early publications.  But no barrier is needed on
1013   // exceptional returns, since they cannot publish normally.
1014   //
1015   if (method()->is_object_initializer() &&
1016        (wrote_final() || wrote_stable() ||
1017          (AlwaysSafeConstructors && wrote_fields()) ||
1018          (support_IRIW_for_not_multiple_copy_atomic_cpu && wrote_volatile()))) {
1019     Node* recorded_alloc = alloc_with_final_or_stable();
1020     _exits.insert_mem_bar(UseStoreStoreForCtor ? Op_MemBarStoreStore : Op_MemBarRelease,
1021                           recorded_alloc);
1022 
1023     // If Memory barrier is created for final fields write
1024     // and allocation node does not escape the initialize method,
1025     // then barrier introduced by allocation node can be removed.
1026     if (DoEscapeAnalysis && (recorded_alloc != nullptr)) {
1027       AllocateNode* alloc = AllocateNode::Ideal_allocation(recorded_alloc);
1028       alloc->compute_MemBar_redundancy(method());
1029     }
1030     if (PrintOpto && (Verbose || WizardMode)) {
1031       method()->print_name();
1032       tty->print_cr(" writes finals/@Stable and needs a memory barrier");
1033     }
1034   }
1035 
1036   for (MergeMemStream mms(_exits.merged_memory()); mms.next_non_empty(); ) {
1037     // transform each slice of the original memphi:
1038     mms.set_memory(_gvn.transform(mms.memory()));
1039   }
1040   // Clean up input MergeMems created by transforming the slices
1041   _gvn.transform(_exits.merged_memory());
1042 
1043   if (tf()->range()->cnt() > TypeFunc::Parms) {
1044     const Type* ret_type = tf()->range()->field_at(TypeFunc::Parms);
1045     Node*       ret_phi  = _gvn.transform( _exits.argument(0) );
1046     if (!_exits.control()->is_top() && _gvn.type(ret_phi)->empty()) {
1047       // If the type we set for the ret_phi in build_exits() is too optimistic and
1048       // the ret_phi is top now, there's an extremely small chance that it may be due to class
1049       // loading.  It could also be due to an error, so mark this method as not compilable because
1050       // otherwise this could lead to an infinite compile loop.
1051       // In any case, this code path is rarely (and never in my testing) reached.
1052       C->record_method_not_compilable("Can't determine return type.");
1053       return;
1054     }
1055     if (ret_type->isa_int()) {
1056       BasicType ret_bt = method()->return_type()->basic_type();
1057       ret_phi = mask_int_value(ret_phi, ret_bt, &_gvn);
1058     }
1059     _exits.push_node(ret_type->basic_type(), ret_phi);
1060   }
1061 
1062   // Note:  Logic for creating and optimizing the ReturnNode is in Compile.
1063 
1064   // Unlock along the exceptional paths.

1118 
1119 //-----------------------------create_entry_map-------------------------------
1120 // Initialize our parser map to contain the types at method entry.
1121 // For OSR, the map contains a single RawPtr parameter.
1122 // Initial monitor locking for sync. methods is performed by do_method_entry.
1123 SafePointNode* Parse::create_entry_map() {
1124   // Check for really stupid bail-out cases.
1125   uint len = TypeFunc::Parms + method()->max_locals() + method()->max_stack();
1126   if (len >= 32760) {
1127     // Bailout expected, this is a very rare edge case.
1128     C->record_method_not_compilable("too many local variables");
1129     return nullptr;
1130   }
1131 
1132   // clear current replaced nodes that are of no use from here on (map was cloned in build_exits).
1133   _caller->map()->delete_replaced_nodes();
1134 
1135   // If this is an inlined method, we may have to do a receiver null check.
1136   if (_caller->has_method() && is_normal_parse() && !method()->is_static()) {
1137     GraphKit kit(_caller);
1138     kit.null_check_receiver_before_call(method());

1139     _caller = kit.transfer_exceptions_into_jvms();

1140     if (kit.stopped()) {
1141       _exits.add_exception_states_from(_caller);
1142       _exits.set_jvms(_caller);
1143       return nullptr;
1144     }
1145   }
1146 
1147   assert(method() != nullptr, "parser must have a method");
1148 
1149   // Create an initial safepoint to hold JVM state during parsing
1150   JVMState* jvms = new (C) JVMState(method(), _caller->has_method() ? _caller : nullptr);
1151   set_map(new SafePointNode(len, jvms));
1152   jvms->set_map(map());
1153   record_for_igvn(map());
1154   assert(jvms->endoff() == len, "correct jvms sizing");
1155 
1156   SafePointNode* inmap = _caller->map();
1157   assert(inmap != nullptr, "must have inmap");
1158   // In case of null check on receiver above
1159   map()->transfer_replaced_nodes_from(inmap, _new_idx);
1160 
1161   uint i;
1162 
1163   // Pass thru the predefined input parameters.
1164   for (i = 0; i < TypeFunc::Parms; i++) {
1165     map()->init_req(i, inmap->in(i));
1166   }
1167 
1168   if (depth() == 1) {
1169     assert(map()->memory()->Opcode() == Op_Parm, "");
1170     // Insert the memory aliasing node
1171     set_all_memory(reset_memory());
1172   }
1173   assert(merged_memory(), "");
1174 
1175   // Now add the locals which are initially bound to arguments:
1176   uint arg_size = tf()->domain()->cnt();
1177   ensure_stack(arg_size - TypeFunc::Parms);  // OSR methods have funny args
1178   for (i = TypeFunc::Parms; i < arg_size; i++) {
1179     map()->init_req(i, inmap->argument(_caller, i - TypeFunc::Parms));
1180   }
1181 
1182   // Clear out the rest of the map (locals and stack)
1183   for (i = arg_size; i < len; i++) {
1184     map()->init_req(i, top());
1185   }
1186 
1187   SafePointNode* entry_map = stop();
1188   return entry_map;
1189 }
1190 
1191 //-----------------------------do_method_entry--------------------------------
1192 // Emit any code needed in the pseudo-block before BCI zero.
1193 // The main thing to do is lock the receiver of a synchronized method.
1194 void Parse::do_method_entry() {
1195   set_parse_bci(InvocationEntryBci); // Pseudo-BCP
1196   set_sp(0);                         // Java Stack Pointer

1230 
1231   // If the method is synchronized, we need to construct a lock node, attach
1232   // it to the Start node, and pin it there.
1233   if (method()->is_synchronized()) {
1234     // Insert a FastLockNode right after the Start which takes as arguments
1235     // the current thread pointer, the "this" pointer & the address of the
1236     // stack slot pair used for the lock.  The "this" pointer is a projection
1237     // off the start node, but the locking spot has to be constructed by
1238     // creating a ConLNode of 0, and boxing it with a BoxLockNode.  The BoxLockNode
1239     // becomes the second argument to the FastLockNode call.  The
1240     // FastLockNode becomes the new control parent to pin it to the start.
1241 
1242     // Setup Object Pointer
1243     Node *lock_obj = nullptr;
1244     if (method()->is_static()) {
1245       ciInstance* mirror = _method->holder()->java_mirror();
1246       const TypeInstPtr *t_lock = TypeInstPtr::make(mirror);
1247       lock_obj = makecon(t_lock);
1248     } else {                  // Else pass the "this" pointer,
1249       lock_obj = local(0);    // which is Parm0 from StartNode

1250     }
1251     // Clear out dead values from the debug info.
1252     kill_dead_locals();
1253     // Build the FastLockNode
1254     _synch_lock = shared_lock(lock_obj);
1255     // Check for bailout in shared_lock
1256     if (failing()) { return; }
1257   }
1258 
1259   // Feed profiling data for parameters to the type system so it can
1260   // propagate it as speculative types
1261   record_profiled_parameters_for_speculation();
1262 }
1263 
1264 //------------------------------init_blocks------------------------------------
1265 // Initialize our parser map to contain the types/monitors at method entry.
1266 void Parse::init_blocks() {
1267   // Create the blocks.
1268   _block_count = flow()->block_count();
1269   _blocks = NEW_RESOURCE_ARRAY(Block, _block_count);

1665 //--------------------handle_missing_successor---------------------------------
1666 void Parse::handle_missing_successor(int target_bci) {
1667 #ifndef PRODUCT
1668   Block* b = block();
1669   int trap_bci = b->flow()->has_trap()? b->flow()->trap_bci(): -1;
1670   tty->print_cr("### Missing successor at bci:%d for block #%d (trap_bci:%d)", target_bci, b->rpo(), trap_bci);
1671 #endif
1672   ShouldNotReachHere();
1673 }
1674 
1675 //--------------------------merge_common---------------------------------------
1676 void Parse::merge_common(Parse::Block* target, int pnum) {
1677   if (TraceOptoParse) {
1678     tty->print("Merging state at block #%d bci:%d", target->rpo(), target->start());
1679   }
1680 
1681   // Zap extra stack slots to top
1682   assert(sp() == target->start_sp(), "");
1683   clean_stack(sp());
1684 


































































1685   if (!target->is_merged()) {   // No prior mapping at this bci
1686     if (TraceOptoParse) { tty->print(" with empty state");  }
1687 
1688     // If this path is dead, do not bother capturing it as a merge.
1689     // It is "as if" we had 1 fewer predecessors from the beginning.
1690     if (stopped()) {
1691       if (TraceOptoParse)  tty->print_cr(", but path is dead and doesn't count");
1692       return;
1693     }
1694 
1695     // Make a region if we know there are multiple or unpredictable inputs.
1696     // (Also, if this is a plain fall-through, we might see another region,
1697     // which must not be allowed into this block's map.)
1698     if (pnum > PhiNode::Input         // Known multiple inputs.
1699         || target->is_handler()       // These have unpredictable inputs.
1700         || target->is_loop_head()     // Known multiple inputs
1701         || control()->is_Region()) {  // We must hide this guy.
1702 
1703       int current_bci = bci();
1704       set_parse_bci(target->start()); // Set target bci

1719       record_for_igvn(r);
1720       // zap all inputs to null for debugging (done in Node(uint) constructor)
1721       // for (int j = 1; j < edges+1; j++) { r->init_req(j, nullptr); }
1722       r->init_req(pnum, control());
1723       set_control(r);
1724       target->copy_irreducible_status_to(r, jvms());
1725       set_parse_bci(current_bci); // Restore bci
1726     }
1727 
1728     // Convert the existing Parser mapping into a mapping at this bci.
1729     store_state_to(target);
1730     assert(target->is_merged(), "do not come here twice");
1731 
1732   } else {                      // Prior mapping at this bci
1733     if (TraceOptoParse) {  tty->print(" with previous state"); }
1734 #ifdef ASSERT
1735     if (target->is_SEL_head()) {
1736       target->mark_merged_backedge(block());
1737     }
1738 #endif

1739     // We must not manufacture more phis if the target is already parsed.
1740     bool nophi = target->is_parsed();
1741 
1742     SafePointNode* newin = map();// Hang on to incoming mapping
1743     Block* save_block = block(); // Hang on to incoming block;
1744     load_state_from(target);    // Get prior mapping
1745 
1746     assert(newin->jvms()->locoff() == jvms()->locoff(), "JVMS layouts agree");
1747     assert(newin->jvms()->stkoff() == jvms()->stkoff(), "JVMS layouts agree");
1748     assert(newin->jvms()->monoff() == jvms()->monoff(), "JVMS layouts agree");
1749     assert(newin->jvms()->endoff() == jvms()->endoff(), "JVMS layouts agree");
1750 
1751     // Iterate over my current mapping and the old mapping.
1752     // Where different, insert Phi functions.
1753     // Use any existing Phi functions.
1754     assert(control()->is_Region(), "must be merging to a region");
1755     RegionNode* r = control()->as_Region();
1756 
1757     // Compute where to merge into
1758     // Merge incoming control path
1759     r->init_req(pnum, newin->control());
1760 
1761     if (pnum == 1) {            // Last merge for this Region?
1762       if (!block()->flow()->is_irreducible_loop_secondary_entry()) {
1763         Node* result = _gvn.transform(r);
1764         if (r != result && TraceOptoParse) {
1765           tty->print_cr("Block #%d replace %d with %d", block()->rpo(), r->_idx, result->_idx);
1766         }
1767       }
1768       record_for_igvn(r);
1769     }
1770 
1771     // Update all the non-control inputs to map:
1772     assert(TypeFunc::Parms == newin->jvms()->locoff(), "parser map should contain only youngest jvms");
1773     bool check_elide_phi = target->is_SEL_backedge(save_block);

1774     for (uint j = 1; j < newin->req(); j++) {
1775       Node* m = map()->in(j);   // Current state of target.
1776       Node* n = newin->in(j);   // Incoming change to target state.
1777       PhiNode* phi;
1778       if (m->is_Phi() && m->as_Phi()->region() == r)
1779         phi = m->as_Phi();
1780       else


1781         phi = nullptr;

1782       if (m != n) {             // Different; must merge
1783         switch (j) {
1784         // Frame pointer and Return Address never changes
1785         case TypeFunc::FramePtr:// Drop m, use the original value
1786         case TypeFunc::ReturnAdr:
1787           break;
1788         case TypeFunc::Memory:  // Merge inputs to the MergeMem node
1789           assert(phi == nullptr, "the merge contains phis, not vice versa");
1790           merge_memory_edges(n->as_MergeMem(), pnum, nophi);
1791           continue;
1792         default:                // All normal stuff
1793           if (phi == nullptr) {
1794             const JVMState* jvms = map()->jvms();
1795             if (EliminateNestedLocks &&
1796                 jvms->is_mon(j) && jvms->is_monitor_box(j)) {
1797               // BoxLock nodes are not commoning when EliminateNestedLocks is on.
1798               // Use old BoxLock node as merged box.
1799               assert(newin->jvms()->is_monitor_box(j), "sanity");
1800               // This assert also tests that nodes are BoxLock.
1801               assert(BoxLockNode::same_slot(n, m), "sanity");

1808                 // Incremental Inlining before EA and Macro nodes elimination.
1809                 //
1810                 // Incremental Inlining is executed after IGVN optimizations
1811                 // during which BoxLock can be marked as Coarsened.
1812                 old_box->set_coarsened(); // Verifies state
1813                 old_box->set_unbalanced();
1814               }
1815               C->gvn_replace_by(n, m);
1816             } else if (!check_elide_phi || !target->can_elide_SEL_phi(j)) {
1817               phi = ensure_phi(j, nophi);
1818             }
1819           }
1820           break;
1821         }
1822       }
1823       // At this point, n might be top if:
1824       //  - there is no phi (because TypeFlow detected a conflict), or
1825       //  - the corresponding control edges is top (a dead incoming path)
1826       // It is a bug if we create a phi which sees a garbage value on a live path.
1827 
1828       if (phi != nullptr) {

























1829         assert(n != top() || r->in(pnum) == top(), "live value must not be garbage");
1830         assert(phi->region() == r, "");
1831         phi->set_req(pnum, n);  // Then add 'n' to the merge
1832         if (pnum == PhiNode::Input) {
1833           // Last merge for this Phi.
1834           // So far, Phis have had a reasonable type from ciTypeFlow.
1835           // Now _gvn will join that with the meet of current inputs.
1836           // BOTTOM is never permissible here, 'cause pessimistically
1837           // Phis of pointers cannot lose the basic pointer type.
1838           DEBUG_ONLY(const Type* bt1 = phi->bottom_type());
1839           assert(bt1 != Type::BOTTOM, "should not be building conflict phis");
1840           map()->set_req(j, _gvn.transform(phi));
1841           DEBUG_ONLY(const Type* bt2 = phi->bottom_type());
1842           assert(bt2->higher_equal_speculative(bt1), "must be consistent with type-flow");
1843           record_for_igvn(phi);
1844         }
1845       }
1846     } // End of for all values to be merged
1847 
1848     if (pnum == PhiNode::Input &&
1849         !r->in(0)) {         // The occasional useless Region
1850       assert(control() == r, "");
1851       set_control(r->nonnull_req());
1852     }
1853 
1854     map()->merge_replaced_nodes_with(newin);
1855 
1856     // newin has been subsumed into the lazy merge, and is now dead.
1857     set_block(save_block);
1858 
1859     stop();                     // done with this guy, for now
1860   }
1861 
1862   if (TraceOptoParse) {
1863     tty->print_cr(" on path %d", pnum);
1864   }
1865 
1866   // Done with this parser state.
1867   assert(stopped(), "");
1868 }
1869 

1981 
1982   // Add new path to the region.
1983   uint pnum = r->req();
1984   r->add_req(nullptr);
1985 
1986   for (uint i = 1; i < map->req(); i++) {
1987     Node* n = map->in(i);
1988     if (i == TypeFunc::Memory) {
1989       // Ensure a phi on all currently known memories.
1990       for (MergeMemStream mms(n->as_MergeMem()); mms.next_non_empty(); ) {
1991         Node* phi = mms.memory();
1992         if (phi->is_Phi() && phi->as_Phi()->region() == r) {
1993           assert(phi->req() == pnum, "must be same size as region");
1994           phi->add_req(nullptr);
1995         }
1996       }
1997     } else {
1998       if (n->is_Phi() && n->as_Phi()->region() == r) {
1999         assert(n->req() == pnum, "must be same size as region");
2000         n->add_req(nullptr);


2001       }
2002     }
2003   }
2004 
2005   return pnum;
2006 }
2007 
2008 //------------------------------ensure_phi-------------------------------------
2009 // Turn the idx'th entry of the current map into a Phi
2010 PhiNode *Parse::ensure_phi(int idx, bool nocreate) {
2011   SafePointNode* map = this->map();
2012   Node* region = map->control();
2013   assert(region->is_Region(), "");
2014 
2015   Node* o = map->in(idx);
2016   assert(o != nullptr, "");
2017 
2018   if (o == top())  return nullptr; // TOP always merges into TOP
2019 
2020   if (o->is_Phi() && o->as_Phi()->region() == region) {
2021     return o->as_Phi();
2022   }




2023 
2024   // Now use a Phi here for merging
2025   assert(!nocreate, "Cannot build a phi for a block already parsed.");
2026   const JVMState* jvms = map->jvms();
2027   const Type* t = nullptr;
2028   if (jvms->is_loc(idx)) {
2029     t = block()->local_type_at(idx - jvms->locoff());
2030   } else if (jvms->is_stk(idx)) {
2031     t = block()->stack_type_at(idx - jvms->stkoff());
2032   } else if (jvms->is_mon(idx)) {
2033     assert(!jvms->is_monitor_box(idx), "no phis for boxes");
2034     t = TypeInstPtr::BOTTOM; // this is sufficient for a lock object
2035   } else if ((uint)idx < TypeFunc::Parms) {
2036     t = o->bottom_type();  // Type::RETURN_ADDRESS or such-like.
2037   } else {
2038     assert(false, "no type information for this phi");
2039   }
2040 
2041   // If the type falls to bottom, then this must be a local that
2042   // is mixing ints and oops or some such.  Forcing it to top
2043   // makes it go dead.
2044   if (t == Type::BOTTOM) {
2045     map->set_req(idx, top());
2046     return nullptr;
2047   }
2048 
2049   // Do not create phis for top either.
2050   // A top on a non-null control flow must be an unused even after the.phi.
2051   if (t == Type::TOP || t == Type::HALF) {
2052     map->set_req(idx, top());
2053     return nullptr;
2054   }
2055 
2056   PhiNode* phi = PhiNode::make(region, o, t);
2057   gvn().set_type(phi, t);
2058   if (C->do_escape_analysis()) record_for_igvn(phi);
2059   map->set_req(idx, phi);
2060   return phi;









2061 }
2062 
2063 //--------------------------ensure_memory_phi----------------------------------
2064 // Turn the idx'th slice of the current memory into a Phi
2065 PhiNode *Parse::ensure_memory_phi(int idx, bool nocreate) {
2066   MergeMemNode* mem = merged_memory();
2067   Node* region = control();
2068   assert(region->is_Region(), "");
2069 
2070   Node *o = (idx == Compile::AliasIdxBot)? mem->base_memory(): mem->memory_at(idx);
2071   assert(o != nullptr && o != top(), "");
2072 
2073   PhiNode* phi;
2074   if (o->is_Phi() && o->as_Phi()->region() == region) {
2075     phi = o->as_Phi();
2076     if (phi == mem->base_memory() && idx >= Compile::AliasIdxRaw) {
2077       // clone the shared base memory phi to make a new memory split
2078       assert(!nocreate, "Cannot build a phi for a block already parsed.");
2079       const Type* t = phi->bottom_type();
2080       const TypePtr* adr_type = C->get_adr_type(idx);

2170 // Add check to deoptimize once holder klass is fully initialized.
2171 void Parse::clinit_deopt() {
2172   assert(C->has_method(), "only for normal compilations");
2173   assert(depth() == 1, "only for main compiled method");
2174   assert(is_normal_parse(), "no barrier needed on osr entry");
2175   assert(!method()->holder()->is_not_initialized(), "initialization should have been started");
2176 
2177   set_parse_bci(0);
2178 
2179   Node* holder = makecon(TypeKlassPtr::make(method()->holder(), Type::trust_interfaces));
2180   guard_klass_being_initialized(holder);
2181 }
2182 
2183 //------------------------------return_current---------------------------------
2184 // Append current _map to _exit_return
2185 void Parse::return_current(Node* value) {
2186   if (method()->intrinsic_id() == vmIntrinsics::_Object_init) {
2187     call_register_finalizer();
2188   }
2189 


































2190   // Do not set_parse_bci, so that return goo is credited to the return insn.
2191   set_bci(InvocationEntryBci);
2192   if (method()->is_synchronized() && GenerateSynchronizationCode) {
2193     shared_unlock(_synch_lock->box_node(), _synch_lock->obj_node());
2194   }
2195   if (C->env()->dtrace_method_probes()) {
2196     make_dtrace_method_exit(method());
2197   }

2198   SafePointNode* exit_return = _exits.map();
2199   exit_return->in( TypeFunc::Control  )->add_req( control() );
2200   exit_return->in( TypeFunc::I_O      )->add_req( i_o    () );
2201   Node *mem = exit_return->in( TypeFunc::Memory   );
2202   for (MergeMemStream mms(mem->as_MergeMem(), merged_memory()); mms.next_non_empty2(); ) {
2203     if (mms.is_empty()) {
2204       // get a copy of the base memory, and patch just this one input
2205       const TypePtr* adr_type = mms.adr_type(C);
2206       Node* phi = mms.force_memory()->as_Phi()->slice_memory(adr_type);
2207       assert(phi->as_Phi()->region() == mms.base_memory()->in(0), "");
2208       gvn().set_type_bottom(phi);
2209       phi->del_req(phi->req()-1);  // prepare to re-patch
2210       mms.set_memory(phi);
2211     }
2212     mms.memory()->add_req(mms.memory2());
2213   }
2214 
2215   // frame pointer is always same, already captured
2216   if (value != nullptr) {
2217     // If returning oops to an interface-return, there is a silent free
2218     // cast from oop to interface allowed by the Verifier.  Make it explicit
2219     // here.
2220     Node* phi = _exits.argument(0);
2221     phi->add_req(value);
2222   }
2223 
2224   if (_first_return) {
2225     _exits.map()->transfer_replaced_nodes_from(map(), _new_idx);
2226     _first_return = false;
2227   } else {
2228     _exits.map()->merge_replaced_nodes_with(map());
2229   }
2230 
2231   stop_and_kill_map();          // This CFG path dies here
2232 }
2233 
2234 
2235 //------------------------------add_safepoint----------------------------------
2236 void Parse::add_safepoint() {
2237   uint parms = TypeFunc::Parms+1;
2238 
2239   // Clear out dead values from the debug info.
2240   kill_dead_locals();
2241 
2242   // Clone the JVM State
2243   SafePointNode *sfpnt = new SafePointNode(parms, nullptr);

  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "compiler/compileLog.hpp"
  26 #include "interpreter/linkResolver.hpp"
  27 #include "memory/resourceArea.hpp"
  28 #include "oops/method.hpp"
  29 #include "opto/addnode.hpp"
  30 #include "opto/c2compiler.hpp"
  31 #include "opto/castnode.hpp"
  32 #include "opto/convertnode.hpp"
  33 #include "opto/idealGraphPrinter.hpp"
  34 #include "opto/inlinetypenode.hpp"
  35 #include "opto/locknode.hpp"
  36 #include "opto/memnode.hpp"
  37 #include "opto/opaquenode.hpp"
  38 #include "opto/parse.hpp"
  39 #include "opto/rootnode.hpp"
  40 #include "opto/runtime.hpp"
  41 #include "opto/type.hpp"
  42 #include "runtime/handles.inline.hpp"
  43 #include "runtime/safepointMechanism.hpp"
  44 #include "runtime/sharedRuntime.hpp"
  45 #include "utilities/bitMap.inline.hpp"
  46 #include "utilities/copy.hpp"
  47 
  48 // Static array so we can figure out which bytecodes stop us from compiling
  49 // the most. Some of the non-static variables are needed in bytecodeInfo.cpp
  50 // and eventually should be encapsulated in a proper class (gri 8/18/98).
  51 
  52 #ifndef PRODUCT
  53 uint nodes_created             = 0;
  54 uint methods_parsed            = 0;

  86   }
  87   if (all_null_checks_found) {
  88     tty->print_cr("%u made implicit (%2u%%)", implicit_null_checks,
  89                   (100*implicit_null_checks)/all_null_checks_found);
  90   }
  91   if (SharedRuntime::_implicit_null_throws) {
  92     tty->print_cr("%u implicit null exceptions at runtime",
  93                   SharedRuntime::_implicit_null_throws);
  94   }
  95 
  96   if (PrintParseStatistics && BytecodeParseHistogram::initialized()) {
  97     BytecodeParseHistogram::print();
  98   }
  99 }
 100 #endif
 101 
 102 //------------------------------ON STACK REPLACEMENT---------------------------
 103 
 104 // Construct a node which can be used to get incoming state for
 105 // on stack replacement.
 106 Node* Parse::fetch_interpreter_state(int index,
 107                                      const Type* type,
 108                                      Node* local_addrs,
 109                                      Node* local_addrs_base) {
 110   BasicType bt = type->basic_type();
 111   if (type == TypePtr::NULL_PTR) {
 112     // Ptr types are mixed together with T_ADDRESS but nullptr is
 113     // really for T_OBJECT types so correct it.
 114     bt = T_OBJECT;
 115   }
 116   Node *mem = memory(Compile::AliasIdxRaw);
 117   Node *adr = basic_plus_adr( local_addrs_base, local_addrs, -index*wordSize );
 118   Node *ctl = control();
 119 
 120   // Very similar to LoadNode::make, except we handle un-aligned longs and
 121   // doubles on Sparc.  Intel can handle them just fine directly.
 122   Node *l = nullptr;
 123   switch (bt) {                // Signature is flattened
 124   case T_INT:     l = new LoadINode(ctl, mem, adr, TypeRawPtr::BOTTOM, TypeInt::INT,        MemNode::unordered); break;
 125   case T_FLOAT:   l = new LoadFNode(ctl, mem, adr, TypeRawPtr::BOTTOM, Type::FLOAT,         MemNode::unordered); break;
 126   case T_ADDRESS: l = new LoadPNode(ctl, mem, adr, TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM,  MemNode::unordered); break;
 127   case T_OBJECT:  l = new LoadPNode(ctl, mem, adr, TypeRawPtr::BOTTOM, TypeInstPtr::BOTTOM, MemNode::unordered); break;
 128   case T_LONG:
 129   case T_DOUBLE: {
 130     // Since arguments are in reverse order, the argument address 'adr'
 131     // refers to the back half of the long/double.  Recompute adr.
 132     adr = basic_plus_adr(local_addrs_base, local_addrs, -(index+1)*wordSize);
 133     if (Matcher::misaligned_doubles_ok) {
 134       l = (bt == T_DOUBLE)
 135         ? (Node*)new LoadDNode(ctl, mem, adr, TypeRawPtr::BOTTOM, Type::DOUBLE, MemNode::unordered)
 136         : (Node*)new LoadLNode(ctl, mem, adr, TypeRawPtr::BOTTOM, TypeLong::LONG, MemNode::unordered);
 137     } else {
 138       l = (bt == T_DOUBLE)
 139         ? (Node*)new LoadD_unalignedNode(ctl, mem, adr, TypeRawPtr::BOTTOM, MemNode::unordered)
 140         : (Node*)new LoadL_unalignedNode(ctl, mem, adr, TypeRawPtr::BOTTOM, MemNode::unordered);
 141     }
 142     break;
 143   }
 144   default: ShouldNotReachHere();
 145   }
 146   return _gvn.transform(l);
 147 }
 148 
 149 // Helper routine to prevent the interpreter from handing
 150 // unexpected typestate to an OSR method.
 151 // The Node l is a value newly dug out of the interpreter frame.
 152 // The type is the type predicted by ciTypeFlow.  Note that it is
 153 // not a general type, but can only come from Type::get_typeflow_type.
 154 // The safepoint is a map which will feed an uncommon trap.
 155 Node* Parse::check_interpreter_type(Node* l, const Type* type,
 156                                     SafePointNode* &bad_type_exit, bool is_early_larval) {

 157   const TypeOopPtr* tp = type->isa_oopptr();
 158 
 159   // TypeFlow may assert null-ness if a type appears unloaded.
 160   if (type == TypePtr::NULL_PTR ||
 161       (tp != nullptr && !tp->is_loaded())) {
 162     // Value must be null, not a real oop.
 163     Node* chk = _gvn.transform( new CmpPNode(l, null()) );
 164     Node* tst = _gvn.transform( new BoolNode(chk, BoolTest::eq) );
 165     IfNode* iff = create_and_map_if(control(), tst, PROB_MAX, COUNT_UNKNOWN);
 166     set_control(_gvn.transform( new IfTrueNode(iff) ));
 167     Node* bad_type = _gvn.transform( new IfFalseNode(iff) );
 168     bad_type_exit->control()->add_req(bad_type);
 169     l = null();
 170   }
 171 
 172   // Typeflow can also cut off paths from the CFG, based on
 173   // types which appear unloaded, or call sites which appear unlinked.
 174   // When paths are cut off, values at later merge points can rise
 175   // toward more specific classes.  Make sure these specific classes
 176   // are still in effect.
 177   if (tp != nullptr && !tp->is_same_java_type_as(TypeInstPtr::BOTTOM)) {
 178     // TypeFlow asserted a specific object type.  Value must have that type.
 179     Node* bad_type_ctrl = nullptr;
 180     if (tp->is_inlinetypeptr() && !tp->maybe_null()) {
 181       // Check inline types for null here to prevent checkcast from adding an
 182       // exception state before the bytecode entry (use 'bad_type_ctrl' instead).
 183       l = null_check_oop(l, &bad_type_ctrl);
 184       bad_type_exit->control()->add_req(bad_type_ctrl);
 185     }
 186 
 187     l = gen_checkcast(l, makecon(tp->as_klass_type()->cast_to_exactness(true)), &bad_type_ctrl, false, is_early_larval);
 188     bad_type_exit->control()->add_req(bad_type_ctrl);
 189   }
 190 
 191   assert(_gvn.type(l)->higher_equal(type), "must constrain OSR typestate");
 192   return l;
 193 }
 194 
 195 // Helper routine which sets up elements of the initial parser map when
 196 // performing a parse for on stack replacement.  Add values into map.
 197 // The only parameter contains the address of a interpreter arguments.
 198 void Parse::load_interpreter_state(Node* osr_buf) {
 199   int index;
 200   int max_locals = jvms()->loc_size();
 201   int max_stack  = jvms()->stk_size();
 202 

 203   // Mismatch between method and jvms can occur since map briefly held
 204   // an OSR entry state (which takes up one RawPtr word).
 205   assert(max_locals == method()->max_locals(), "sanity");
 206   assert(max_stack  >= method()->max_stack(),  "sanity");
 207   assert((int)jvms()->endoff() == TypeFunc::Parms + max_locals + max_stack, "sanity");
 208   assert((int)jvms()->endoff() == (int)map()->req(), "sanity");
 209 
 210   // Find the start block.
 211   Block* osr_block = start_block();
 212   assert(osr_block->start() == osr_bci(), "sanity");
 213 
 214   // Set initial BCI.
 215   set_parse_bci(osr_block->start());
 216 
 217   // Set initial stack depth.
 218   set_sp(osr_block->start_sp());
 219 
 220   // Check bailouts.  We currently do not perform on stack replacement
 221   // of loops in catch blocks or loops which branch with a non-empty stack.
 222   if (sp() != 0) {

 237   for (index = 0; index < mcnt; index++) {
 238     // Make a BoxLockNode for the monitor.
 239     BoxLockNode* osr_box = new BoxLockNode(next_monitor());
 240     // Check for bailout after new BoxLockNode
 241     if (failing()) { return; }
 242 
 243     // This OSR locking region is unbalanced because it does not have Lock node:
 244     // locking was done in Interpreter.
 245     // This is similar to Coarsened case when Lock node is eliminated
 246     // and as result the region is marked as Unbalanced.
 247 
 248     // Emulate Coarsened state transition from Regular to Unbalanced.
 249     osr_box->set_coarsened();
 250     osr_box->set_unbalanced();
 251 
 252     Node* box = _gvn.transform(osr_box);
 253 
 254     // Displaced headers and locked objects are interleaved in the
 255     // temp OSR buffer.  We only copy the locked objects out here.
 256     // Fetch the locked object from the OSR temp buffer and copy to our fastlock node.
 257     Node* lock_object = fetch_interpreter_state(index*2, Type::get_const_basic_type(T_OBJECT), monitors_addr, osr_buf);
 258     // Try and copy the displaced header to the BoxNode
 259     Node* displaced_hdr = fetch_interpreter_state((index*2) + 1, Type::get_const_basic_type(T_ADDRESS), monitors_addr, osr_buf);

 260 
 261     store_to_memory(control(), box, displaced_hdr, T_ADDRESS, MemNode::unordered);
 262 
 263     // Build a bogus FastLockNode (no code will be generated) and push the
 264     // monitor into our debug info.
 265     const FastLockNode *flock = _gvn.transform(new FastLockNode( nullptr, lock_object, box ))->as_FastLock();
 266     map()->push_monitor(flock);
 267 
 268     // If the lock is our method synchronization lock, tuck it away in
 269     // _sync_lock for return and rethrow exit paths.
 270     if (index == 0 && method()->is_synchronized()) {
 271       _synch_lock = flock;
 272     }
 273   }
 274 
 275   // Use the raw liveness computation to make sure that unexpected
 276   // values don't propagate into the OSR frame.
 277   MethodLivenessResult live_locals = method()->liveness_at_bci(osr_bci());
 278   if (!live_locals.is_valid()) {
 279     // Degenerate or breakpointed method.

 307         if (C->log() != nullptr) {
 308           C->log()->elem("OSR_mismatch local_index='%d'",index);
 309         }
 310         set_local(index, null());
 311         // and ignore it for the loads
 312         continue;
 313       }
 314     }
 315 
 316     // Filter out TOP, HALF, and BOTTOM.  (Cf. ensure_phi.)
 317     if (type == Type::TOP || type == Type::HALF) {
 318       continue;
 319     }
 320     // If the type falls to bottom, then this must be a local that
 321     // is mixing ints and oops or some such.  Forcing it to top
 322     // makes it go dead.
 323     if (type == Type::BOTTOM) {
 324       continue;
 325     }
 326     // Construct code to access the appropriate local.
 327     Node* value = fetch_interpreter_state(index, type, locals_addr, osr_buf);






 328     set_local(index, value);
 329   }
 330 
 331   // Extract the needed stack entries from the interpreter frame.
 332   for (index = 0; index < sp(); index++) {
 333     const Type *type = osr_block->stack_type_at(index);
 334     if (type != Type::TOP) {
 335       // Currently the compiler bails out when attempting to on stack replace
 336       // at a bci with a non-empty stack.  We should not reach here.
 337       ShouldNotReachHere();
 338     }
 339   }
 340 
 341   // End the OSR migration
 342   make_runtime_call(RC_LEAF, OptoRuntime::osr_end_Type(),
 343                     CAST_FROM_FN_PTR(address, SharedRuntime::OSR_migration_end),
 344                     "OSR_migration_end", TypeRawPtr::BOTTOM,
 345                     osr_buf);
 346 
 347   // Now that the interpreter state is loaded, make sure it will match

 358     if (type->isa_oopptr() != nullptr) {
 359       if (!live_oops.at(index)) {
 360         // skip type check for dead oops
 361         continue;
 362       }
 363     }
 364     if (osr_block->flow()->local_type_at(index)->is_return_address()) {
 365       // In our current system it's illegal for jsr addresses to be
 366       // live into an OSR entry point because the compiler performs
 367       // inlining of jsrs.  ciTypeFlow has a bailout that detect this
 368       // case and aborts the compile if addresses are live into an OSR
 369       // entry point.  Because of that we can assume that any address
 370       // locals at the OSR entry point are dead.  Method liveness
 371       // isn't precise enough to figure out that they are dead in all
 372       // cases so simply skip checking address locals all
 373       // together. Any type check is guaranteed to fail since the
 374       // interpreter type is the result of a load which might have any
 375       // value and the expected type is a constant.
 376       continue;
 377     }
 378     bool is_early_larval = osr_block->flow()->local_type_at(index)->is_early_larval();
 379     set_local(index, check_interpreter_type(l, type, bad_type_exit, is_early_larval));
 380   }
 381 
 382   for (index = 0; index < sp(); index++) {
 383     if (stopped())  break;
 384     Node* l = stack(index);
 385     if (l->is_top())  continue;  // nothing here
 386     const Type *type = osr_block->stack_type_at(index);
 387     bool is_early_larval = osr_block->flow()->stack_type_at(index)->is_early_larval();
 388     set_stack(index, check_interpreter_type(l, type, bad_type_exit, is_early_larval));
 389   }
 390 
 391   if (bad_type_exit->control()->req() > 1) {
 392     // Build an uncommon trap here, if any inputs can be unexpected.
 393     bad_type_exit->set_control(_gvn.transform( bad_type_exit->control() ));
 394     record_for_igvn(bad_type_exit->control());
 395     SafePointNode* types_are_good = map();
 396     set_map(bad_type_exit);
 397     // The unexpected type happens because a new edge is active
 398     // in the CFG, which typeflow had previously ignored.
 399     // E.g., Object x = coldAtFirst() && notReached()? "str": new Integer(123).
 400     // This x will be typed as Integer if notReached is not yet linked.
 401     // It could also happen due to a problem in ciTypeFlow analysis.
 402     uncommon_trap(Deoptimization::Reason_constraint,
 403                   Deoptimization::Action_reinterpret);
 404     set_map(types_are_good);
 405   }
 406 }
 407 
 408 //------------------------------Parse------------------------------------------

 509   // either breakpoint setting or hotswapping of methods may
 510   // cause deoptimization.
 511   if (C->env()->jvmti_can_hotswap_or_post_breakpoint()) {
 512     C->dependencies()->assert_evol_method(method());
 513   }
 514 
 515   NOT_PRODUCT(methods_seen++);
 516 
 517   // Do some special top-level things.
 518   if (depth() == 1 && C->is_osr_compilation()) {
 519     _tf = C->tf();     // the OSR entry type is different
 520     _entry_bci = C->entry_bci();
 521     _flow = method()->get_osr_flow_analysis(osr_bci());
 522   } else {
 523     _tf = TypeFunc::make(method());
 524     _entry_bci = InvocationEntryBci;
 525     _flow = method()->get_flow_analysis();
 526   }
 527 
 528   if (_flow->failing()) {
 529     // TODO Adding a trap due to an unloaded return type in ciTypeFlow::StateVector::do_invoke
 530     // can lead to this. Re-enable once 8284443 is fixed.
 531     //assert(false, "type flow analysis failed during parsing");
 532     C->record_method_not_compilable(_flow->failure_reason());
 533 #ifndef PRODUCT
 534       if (PrintOpto && (Verbose || WizardMode)) {
 535         if (is_osr_parse()) {
 536           tty->print_cr("OSR @%d type flow bailout: %s", _entry_bci, _flow->failure_reason());
 537         } else {
 538           tty->print_cr("type flow bailout: %s", _flow->failure_reason());
 539         }
 540         if (Verbose) {
 541           method()->print();
 542           method()->print_codes();
 543           _flow->print();
 544         }
 545       }
 546 #endif
 547   }
 548 
 549 #ifdef ASSERT
 550   if (depth() == 1) {
 551     assert(C->is_osr_compilation() == this->is_osr_parse(), "OSR in sync");

 602     load_interpreter_state(osr_buf);
 603   } else {
 604     set_map(entry_map);
 605     do_method_entry();
 606   }
 607 
 608   if (depth() == 1 && !failing()) {
 609     if (C->clinit_barrier_on_entry()) {
 610       // Add check to deoptimize the nmethod once the holder class is fully initialized
 611       clinit_deopt();
 612     }
 613   }
 614 
 615   // Check for bailouts during method entry.
 616   if (failing()) {
 617     if (log)  log->done("parse");
 618     C->set_default_node_notes(caller_nn);
 619     return;
 620   }
 621 
 622   // Handle inline type arguments
 623   int arg_size = method()->arg_size();
 624   for (int i = 0; i < arg_size; i++) {
 625     Node* parm = local(i);
 626     const Type* t = _gvn.type(parm);
 627     if (t->is_inlinetypeptr()) {
 628       // If the parameter is a value object, try to scalarize it if we know that it is unrestricted (not early larval)
 629       // Parameters are non-larval except the receiver of a constructor, which must be an early larval object.
 630       if (!(method()->is_object_constructor() && i == 0)) {
 631         // Create InlineTypeNode from the oop and replace the parameter
 632         Node* vt = InlineTypeNode::make_from_oop(this, parm, t->inline_klass());
 633         replace_in_map(parm, vt);
 634       }
 635     } else if (UseTypeSpeculation && (i == (arg_size - 1)) && !is_osr_parse() && method()->has_vararg() &&
 636                t->isa_aryptr() != nullptr && !t->is_aryptr()->is_null_free() && !t->is_aryptr()->is_flat() &&
 637                (!t->is_aryptr()->is_not_null_free() || !t->is_aryptr()->is_not_flat())) {
 638       // Speculate on varargs Object array being not null-free and not flat
 639       const TypePtr* spec_type = t->speculative();
 640       spec_type = (spec_type != nullptr && spec_type->isa_aryptr() != nullptr) ? spec_type : t->is_aryptr();
 641       spec_type = spec_type->remove_speculative()->is_aryptr()->cast_to_not_null_free()->cast_to_not_flat();
 642       spec_type = TypeOopPtr::make(TypePtr::BotPTR, Type::Offset::bottom, TypeOopPtr::InstanceBot, spec_type);
 643       Node* cast = _gvn.transform(new CheckCastPPNode(control(), parm, t->join_speculative(spec_type)));
 644       replace_in_map(parm, cast);
 645     }
 646   }
 647 
 648   entry_map = map();  // capture any changes performed by method setup code
 649   assert(jvms()->endoff() == map()->req(), "map matches JVMS layout");
 650 
 651   // We begin parsing as if we have just encountered a jump to the
 652   // method entry.
 653   Block* entry_block = start_block();
 654   assert(entry_block->start() == (is_osr_parse() ? osr_bci() : 0), "");
 655   set_map_clone(entry_map);
 656   merge_common(entry_block, entry_block->next_path_num());
 657 
 658 #ifndef PRODUCT
 659   BytecodeParseHistogram *parse_histogram_obj = new (C->env()->arena()) BytecodeParseHistogram(this, C);
 660   set_parse_histogram( parse_histogram_obj );
 661 #endif
 662 
 663   // Parse all the basic blocks.
 664   do_all_blocks();
 665 
 666   // Check for bailouts during conversion to graph
 667   if (failing()) {

 813 void Parse::build_exits() {
 814   // make a clone of caller to prevent sharing of side-effects
 815   _exits.set_map(_exits.clone_map());
 816   _exits.clean_stack(_exits.sp());
 817   _exits.sync_jvms();
 818 
 819   RegionNode* region = new RegionNode(1);
 820   record_for_igvn(region);
 821   gvn().set_type_bottom(region);
 822   _exits.set_control(region);
 823 
 824   // Note:  iophi and memphi are not transformed until do_exits.
 825   Node* iophi  = new PhiNode(region, Type::ABIO);
 826   Node* memphi = new PhiNode(region, Type::MEMORY, TypePtr::BOTTOM);
 827   gvn().set_type_bottom(iophi);
 828   gvn().set_type_bottom(memphi);
 829   _exits.set_i_o(iophi);
 830   _exits.set_all_memory(memphi);
 831 
 832   // Add a return value to the exit state.  (Do not push it yet.)
 833   if (tf()->range_sig()->cnt() > TypeFunc::Parms) {
 834     const Type* ret_type = tf()->range_sig()->field_at(TypeFunc::Parms);
 835     if (ret_type->isa_int()) {
 836       BasicType ret_bt = method()->return_type()->basic_type();
 837       if (ret_bt == T_BOOLEAN ||
 838           ret_bt == T_CHAR ||
 839           ret_bt == T_BYTE ||
 840           ret_bt == T_SHORT) {
 841         ret_type = TypeInt::INT;
 842       }
 843     }
 844 
 845     // Don't "bind" an unloaded return klass to the ret_phi. If the klass
 846     // becomes loaded during the subsequent parsing, the loaded and unloaded
 847     // types will not join when we transform and push in do_exits().
 848     const TypeOopPtr* ret_oop_type = ret_type->isa_oopptr();
 849     if (ret_oop_type && !ret_oop_type->is_loaded()) {
 850       ret_type = TypeOopPtr::BOTTOM;
 851     }
 852     int         ret_size = type2size[ret_type->basic_type()];
 853     Node*       ret_phi  = new PhiNode(region, ret_type);
 854     gvn().set_type_bottom(ret_phi);
 855     _exits.ensure_stack(ret_size);
 856     assert((int)(tf()->range_sig()->cnt() - TypeFunc::Parms) == ret_size, "good tf range");
 857     assert(method()->return_type()->size() == ret_size, "tf agrees w/ method");
 858     _exits.set_argument(0, ret_phi);  // here is where the parser finds it
 859     // Note:  ret_phi is not yet pushed, until do_exits.
 860   }
 861 }
 862 

 863 //----------------------------build_start_state-------------------------------
 864 // Construct a state which contains only the incoming arguments from an
 865 // unknown caller.  The method & bci will be null & InvocationEntryBci.
 866 JVMState* Compile::build_start_state(StartNode* start, const TypeFunc* tf) {
 867   int        arg_size = tf->domain_sig()->cnt();
 868   int        max_size = MAX2(arg_size, (int)tf->range_cc()->cnt());
 869   JVMState*  jvms     = new (this) JVMState(max_size - TypeFunc::Parms);
 870   SafePointNode* map  = new SafePointNode(max_size, jvms);
 871   jvms->set_map(map);
 872   record_for_igvn(map);
 873   assert(arg_size == TypeFunc::Parms + (is_osr_compilation() ? 1 : method()->arg_size()), "correct arg_size");
 874   Node_Notes* old_nn = default_node_notes();
 875   if (old_nn != nullptr && has_method()) {
 876     Node_Notes* entry_nn = old_nn->clone(this);
 877     JVMState* entry_jvms = new(this) JVMState(method(), old_nn->jvms());
 878     entry_jvms->set_offsets(0);
 879     entry_jvms->set_bci(entry_bci());
 880     entry_nn->set_jvms(entry_jvms);
 881     set_default_node_notes(entry_nn);
 882   }
 883   PhaseGVN& gvn = *initial_gvn();
 884   uint i = 0;
 885   int arg_num = 0;
 886   for (uint j = 0; i < (uint)arg_size; i++) {
 887     const Type* t = tf->domain_sig()->field_at(i);
 888     Node* parm = nullptr;
 889     if (t->is_inlinetypeptr() && method()->is_scalarized_arg(arg_num)) {
 890       // Inline type arguments are not passed by reference: we get an argument per
 891       // field of the inline type. Build InlineTypeNodes from the inline type arguments.
 892       GraphKit kit(jvms, &gvn);
 893       kit.set_control(map->control());
 894       Node* old_mem = map->memory();
 895       // Use immutable memory for inline type loads and restore it below
 896       kit.set_all_memory(C->immutable_memory());
 897       parm = InlineTypeNode::make_from_multi(&kit, start, t->inline_klass(), j, /* in= */ true, /* null_free= */ !t->maybe_null());
 898       map->set_control(kit.control());
 899       map->set_memory(old_mem);
 900     } else {
 901       parm = gvn.transform(new ParmNode(start, j++));
 902     }
 903     map->init_req(i, parm);
 904     // Record all these guys for later GVN.
 905     record_for_igvn(parm);
 906     if (i >= TypeFunc::Parms && t != Type::HALF) {
 907       arg_num++;
 908     }
 909   }
 910   for (; i < map->req(); i++) {
 911     map->init_req(i, top());
 912   }
 913   assert(jvms->argoff() == TypeFunc::Parms, "parser gets arguments here");
 914   set_default_node_notes(old_nn);

 915   return jvms;
 916 }
 917 
 918 //-----------------------------make_node_notes---------------------------------
 919 Node_Notes* Parse::make_node_notes(Node_Notes* caller_nn) {
 920   if (caller_nn == nullptr)  return nullptr;
 921   Node_Notes* nn = caller_nn->clone(C);
 922   JVMState* caller_jvms = nn->jvms();
 923   JVMState* jvms = new (C) JVMState(method(), caller_jvms);
 924   jvms->set_offsets(0);
 925   jvms->set_bci(_entry_bci);
 926   nn->set_jvms(jvms);
 927   return nn;
 928 }
 929 
 930 
 931 //--------------------------return_values--------------------------------------
 932 void Compile::return_values(JVMState* jvms) {
 933   GraphKit kit(jvms);
 934   Node* ret = new ReturnNode(TypeFunc::Parms,
 935                              kit.control(),
 936                              kit.i_o(),
 937                              kit.reset_memory(),
 938                              kit.frameptr(),
 939                              kit.returnadr());
 940   // Add zero or 1 return values
 941   int ret_size = tf()->range_sig()->cnt() - TypeFunc::Parms;
 942   if (ret_size > 0) {
 943     kit.inc_sp(-ret_size);  // pop the return value(s)
 944     kit.sync_jvms();
 945     Node* res = kit.argument(0);
 946     if (tf()->returns_inline_type_as_fields()) {
 947       // Multiple return values (inline type fields): add as many edges
 948       // to the Return node as returned values.
 949       InlineTypeNode* vt = res->as_InlineType();
 950       ret->add_req_batch(nullptr, tf()->range_cc()->cnt() - TypeFunc::Parms);
 951       if (vt->is_allocated(&kit.gvn()) && !StressCallingConvention) {
 952         ret->init_req(TypeFunc::Parms, vt);
 953       } else {
 954         // Return the tagged klass pointer to signal scalarization to the caller
 955         Node* tagged_klass = vt->tagged_klass(kit.gvn());
 956         // Return null if the inline type is null (null marker field is not set)
 957         Node* conv   = kit.gvn().transform(new ConvI2LNode(vt->get_null_marker()));
 958         Node* shl    = kit.gvn().transform(new LShiftLNode(conv, kit.intcon(63)));
 959         Node* shr    = kit.gvn().transform(new RShiftLNode(shl, kit.intcon(63)));
 960         tagged_klass = kit.gvn().transform(new AndLNode(tagged_klass, shr));
 961         ret->init_req(TypeFunc::Parms, tagged_klass);
 962       }
 963       uint idx = TypeFunc::Parms + 1;
 964       vt->pass_fields(&kit, ret, idx, false, false);
 965     } else {
 966       ret->add_req(res);
 967       // Note:  The second dummy edge is not needed by a ReturnNode.
 968     }
 969   }
 970   // bind it to root
 971   root()->add_req(ret);
 972   record_for_igvn(ret);
 973   initial_gvn()->transform(ret);
 974 }
 975 
 976 //------------------------rethrow_exceptions-----------------------------------
 977 // Bind all exception states in the list into a single RethrowNode.
 978 void Compile::rethrow_exceptions(JVMState* jvms) {
 979   GraphKit kit(jvms);
 980   if (!kit.has_exceptions())  return;  // nothing to generate
 981   // Load my combined exception state into the kit, with all phis transformed:
 982   SafePointNode* ex_map = kit.combine_and_pop_all_exception_states();
 983   Node* ex_oop = kit.use_exception_state(ex_map);
 984   RethrowNode* exit = new RethrowNode(kit.control(),
 985                                       kit.i_o(), kit.reset_memory(),
 986                                       kit.frameptr(), kit.returnadr(),
 987                                       // like a return but with exception input
 988                                       ex_oop);

1072   //    to complete, we force all writes to complete.
1073   //
1074   // 2. Experimental VM option is used to force the barrier if any field
1075   //    was written out in the constructor.
1076   //
1077   // 3. On processors which are not CPU_MULTI_COPY_ATOMIC (e.g. PPC64),
1078   //    support_IRIW_for_not_multiple_copy_atomic_cpu selects that
1079   //    MemBarVolatile is used before volatile load instead of after volatile
1080   //    store, so there's no barrier after the store.
1081   //    We want to guarantee the same behavior as on platforms with total store
1082   //    order, although this is not required by the Java memory model.
1083   //    In this case, we want to enforce visibility of volatile field
1084   //    initializations which are performed in constructors.
1085   //    So as with finals, we add a barrier here.
1086   //
1087   // "All bets are off" unless the first publication occurs after a
1088   // normal return from the constructor.  We do not attempt to detect
1089   // such unusual early publications.  But no barrier is needed on
1090   // exceptional returns, since they cannot publish normally.
1091   //
1092   if ((method()->is_object_constructor() || method()->is_class_initializer()) &&
1093        (wrote_final() || wrote_stable() ||
1094          (AlwaysSafeConstructors && wrote_fields()) ||
1095          (support_IRIW_for_not_multiple_copy_atomic_cpu && wrote_volatile()))) {
1096     Node* recorded_alloc = alloc_with_final_or_stable();
1097     _exits.insert_mem_bar(UseStoreStoreForCtor ? Op_MemBarStoreStore : Op_MemBarRelease,
1098                           recorded_alloc);
1099 
1100     // If Memory barrier is created for final fields write
1101     // and allocation node does not escape the initialize method,
1102     // then barrier introduced by allocation node can be removed.
1103     if (DoEscapeAnalysis && (recorded_alloc != nullptr)) {
1104       AllocateNode* alloc = AllocateNode::Ideal_allocation(recorded_alloc);
1105       alloc->compute_MemBar_redundancy(method());
1106     }
1107     if (PrintOpto && (Verbose || WizardMode)) {
1108       method()->print_name();
1109       tty->print_cr(" writes finals/@Stable and needs a memory barrier");
1110     }
1111   }
1112 
1113   for (MergeMemStream mms(_exits.merged_memory()); mms.next_non_empty(); ) {
1114     // transform each slice of the original memphi:
1115     mms.set_memory(_gvn.transform(mms.memory()));
1116   }
1117   // Clean up input MergeMems created by transforming the slices
1118   _gvn.transform(_exits.merged_memory());
1119 
1120   if (tf()->range_sig()->cnt() > TypeFunc::Parms) {
1121     const Type* ret_type = tf()->range_sig()->field_at(TypeFunc::Parms);
1122     Node*       ret_phi  = _gvn.transform( _exits.argument(0) );
1123     if (!_exits.control()->is_top() && _gvn.type(ret_phi)->empty()) {
1124       // If the type we set for the ret_phi in build_exits() is too optimistic and
1125       // the ret_phi is top now, there's an extremely small chance that it may be due to class
1126       // loading.  It could also be due to an error, so mark this method as not compilable because
1127       // otherwise this could lead to an infinite compile loop.
1128       // In any case, this code path is rarely (and never in my testing) reached.
1129       C->record_method_not_compilable("Can't determine return type.");
1130       return;
1131     }
1132     if (ret_type->isa_int()) {
1133       BasicType ret_bt = method()->return_type()->basic_type();
1134       ret_phi = mask_int_value(ret_phi, ret_bt, &_gvn);
1135     }
1136     _exits.push_node(ret_type->basic_type(), ret_phi);
1137   }
1138 
1139   // Note:  Logic for creating and optimizing the ReturnNode is in Compile.
1140 
1141   // Unlock along the exceptional paths.

1195 
1196 //-----------------------------create_entry_map-------------------------------
1197 // Initialize our parser map to contain the types at method entry.
1198 // For OSR, the map contains a single RawPtr parameter.
1199 // Initial monitor locking for sync. methods is performed by do_method_entry.
1200 SafePointNode* Parse::create_entry_map() {
1201   // Check for really stupid bail-out cases.
1202   uint len = TypeFunc::Parms + method()->max_locals() + method()->max_stack();
1203   if (len >= 32760) {
1204     // Bailout expected, this is a very rare edge case.
1205     C->record_method_not_compilable("too many local variables");
1206     return nullptr;
1207   }
1208 
1209   // clear current replaced nodes that are of no use from here on (map was cloned in build_exits).
1210   _caller->map()->delete_replaced_nodes();
1211 
1212   // If this is an inlined method, we may have to do a receiver null check.
1213   if (_caller->has_method() && is_normal_parse() && !method()->is_static()) {
1214     GraphKit kit(_caller);
1215     Node* receiver = kit.argument(0);
1216     Node* null_free = kit.null_check_receiver_before_call(method());
1217     _caller = kit.transfer_exceptions_into_jvms();
1218 
1219     if (kit.stopped()) {
1220       _exits.add_exception_states_from(_caller);
1221       _exits.set_jvms(_caller);
1222       return nullptr;
1223     }
1224   }
1225 
1226   assert(method() != nullptr, "parser must have a method");
1227 
1228   // Create an initial safepoint to hold JVM state during parsing
1229   JVMState* jvms = new (C) JVMState(method(), _caller->has_method() ? _caller : nullptr);
1230   set_map(new SafePointNode(len, jvms));
1231   jvms->set_map(map());
1232   record_for_igvn(map());
1233   assert(jvms->endoff() == len, "correct jvms sizing");
1234 
1235   SafePointNode* inmap = _caller->map();
1236   assert(inmap != nullptr, "must have inmap");
1237   // In case of null check on receiver above
1238   map()->transfer_replaced_nodes_from(inmap, _new_idx);
1239 
1240   uint i;
1241 
1242   // Pass thru the predefined input parameters.
1243   for (i = 0; i < TypeFunc::Parms; i++) {
1244     map()->init_req(i, inmap->in(i));
1245   }
1246 
1247   if (depth() == 1) {
1248     assert(map()->memory()->Opcode() == Op_Parm, "");
1249     // Insert the memory aliasing node
1250     set_all_memory(reset_memory());
1251   }
1252   assert(merged_memory(), "");
1253 
1254   // Now add the locals which are initially bound to arguments:
1255   uint arg_size = tf()->domain_sig()->cnt();
1256   ensure_stack(arg_size - TypeFunc::Parms);  // OSR methods have funny args
1257   for (i = TypeFunc::Parms; i < arg_size; i++) {
1258     map()->init_req(i, inmap->argument(_caller, i - TypeFunc::Parms));
1259   }
1260 
1261   // Clear out the rest of the map (locals and stack)
1262   for (i = arg_size; i < len; i++) {
1263     map()->init_req(i, top());
1264   }
1265 
1266   SafePointNode* entry_map = stop();
1267   return entry_map;
1268 }
1269 
1270 //-----------------------------do_method_entry--------------------------------
1271 // Emit any code needed in the pseudo-block before BCI zero.
1272 // The main thing to do is lock the receiver of a synchronized method.
1273 void Parse::do_method_entry() {
1274   set_parse_bci(InvocationEntryBci); // Pseudo-BCP
1275   set_sp(0);                         // Java Stack Pointer

1309 
1310   // If the method is synchronized, we need to construct a lock node, attach
1311   // it to the Start node, and pin it there.
1312   if (method()->is_synchronized()) {
1313     // Insert a FastLockNode right after the Start which takes as arguments
1314     // the current thread pointer, the "this" pointer & the address of the
1315     // stack slot pair used for the lock.  The "this" pointer is a projection
1316     // off the start node, but the locking spot has to be constructed by
1317     // creating a ConLNode of 0, and boxing it with a BoxLockNode.  The BoxLockNode
1318     // becomes the second argument to the FastLockNode call.  The
1319     // FastLockNode becomes the new control parent to pin it to the start.
1320 
1321     // Setup Object Pointer
1322     Node *lock_obj = nullptr;
1323     if (method()->is_static()) {
1324       ciInstance* mirror = _method->holder()->java_mirror();
1325       const TypeInstPtr *t_lock = TypeInstPtr::make(mirror);
1326       lock_obj = makecon(t_lock);
1327     } else {                  // Else pass the "this" pointer,
1328       lock_obj = local(0);    // which is Parm0 from StartNode
1329       assert(!_gvn.type(lock_obj)->make_oopptr()->can_be_inline_type(), "can't be an inline type");
1330     }
1331     // Clear out dead values from the debug info.
1332     kill_dead_locals();
1333     // Build the FastLockNode
1334     _synch_lock = shared_lock(lock_obj);
1335     // Check for bailout in shared_lock
1336     if (failing()) { return; }
1337   }
1338 
1339   // Feed profiling data for parameters to the type system so it can
1340   // propagate it as speculative types
1341   record_profiled_parameters_for_speculation();
1342 }
1343 
1344 //------------------------------init_blocks------------------------------------
1345 // Initialize our parser map to contain the types/monitors at method entry.
1346 void Parse::init_blocks() {
1347   // Create the blocks.
1348   _block_count = flow()->block_count();
1349   _blocks = NEW_RESOURCE_ARRAY(Block, _block_count);

1745 //--------------------handle_missing_successor---------------------------------
1746 void Parse::handle_missing_successor(int target_bci) {
1747 #ifndef PRODUCT
1748   Block* b = block();
1749   int trap_bci = b->flow()->has_trap()? b->flow()->trap_bci(): -1;
1750   tty->print_cr("### Missing successor at bci:%d for block #%d (trap_bci:%d)", target_bci, b->rpo(), trap_bci);
1751 #endif
1752   ShouldNotReachHere();
1753 }
1754 
1755 //--------------------------merge_common---------------------------------------
1756 void Parse::merge_common(Parse::Block* target, int pnum) {
1757   if (TraceOptoParse) {
1758     tty->print("Merging state at block #%d bci:%d", target->rpo(), target->start());
1759   }
1760 
1761   // Zap extra stack slots to top
1762   assert(sp() == target->start_sp(), "");
1763   clean_stack(sp());
1764 
1765   // Check for merge conflicts involving inline types
1766   JVMState* old_jvms = map()->jvms();
1767   int old_bci = bci();
1768   JVMState* tmp_jvms = old_jvms->clone_shallow(C);
1769   tmp_jvms->set_should_reexecute(true);
1770   tmp_jvms->bind_map(map());
1771   // Execution needs to restart a the next bytecode (entry of next
1772   // block)
1773   if (target->is_merged() ||
1774       pnum > PhiNode::Input ||
1775       target->is_handler() ||
1776       target->is_loop_head()) {
1777     set_parse_bci(target->start());
1778     for (uint j = TypeFunc::Parms; j < map()->req(); j++) {
1779       Node* n = map()->in(j);                 // Incoming change to target state.
1780       const Type* t = nullptr;
1781       if (tmp_jvms->is_loc(j)) {
1782         t = target->local_type_at(j - tmp_jvms->locoff());
1783       } else if (tmp_jvms->is_stk(j) && j < (uint)sp() + tmp_jvms->stkoff()) {
1784         t = target->stack_type_at(j - tmp_jvms->stkoff());
1785       }
1786       if (t != nullptr && t != Type::BOTTOM) {
1787         // An object can appear in the JVMS as either an oop or an InlineTypeNode. If the merge is
1788         // an InlineTypeNode, we need all the merge inputs to be InlineTypeNodes. Else, if the
1789         // merge is an oop, each merge input needs to be either an oop or an buffered
1790         // InlineTypeNode.
1791         if (!t->is_inlinetypeptr()) {
1792           // The merge cannot be an InlineTypeNode, ensure the input is buffered if it is an
1793           // InlineTypeNode
1794           if (n->is_InlineType()) {
1795             map()->set_req(j, n->as_InlineType()->buffer(this));
1796           }
1797         } else {
1798           // Since the merge is a value object, it can either be an oop or an InlineTypeNode
1799           if (!target->is_merged()) {
1800             // This is the first processed input of the merge. If it is an InlineTypeNode, the
1801             // merge will be an InlineTypeNode. Else, try to scalarize so the merge can be
1802             // scalarized as well. However, we cannot blindly scalarize an inline type oop here
1803             // since it may be larval
1804             if (!n->is_InlineType() && gvn().type(n)->is_zero_type()) {
1805               // Null constant implies that this is not a larval object
1806               map()->set_req(j, InlineTypeNode::make_null(gvn(), t->inline_klass()));
1807             }
1808           } else {
1809             Node* phi = target->start_map()->in(j);
1810             if (phi->is_InlineType()) {
1811               // Larval oops cannot be merged with non-larval ones, and since the merge point is
1812               // non-larval, n must be non-larval as well. As a result, we can scalarize n to merge
1813               // into phi
1814               if (!n->is_InlineType()) {
1815                 map()->set_req(j, InlineTypeNode::make_from_oop(this, n, t->inline_klass()));
1816               }
1817             } else {
1818               // The merge is an oop phi, ensure the input is buffered if it is an InlineTypeNode
1819               if (n->is_InlineType()) {
1820                 map()->set_req(j, n->as_InlineType()->buffer(this));
1821               }
1822             }
1823           }
1824         }
1825       }
1826     }
1827   }
1828   old_jvms->bind_map(map());
1829   set_parse_bci(old_bci);
1830 
1831   if (!target->is_merged()) {   // No prior mapping at this bci
1832     if (TraceOptoParse) { tty->print(" with empty state");  }
1833 
1834     // If this path is dead, do not bother capturing it as a merge.
1835     // It is "as if" we had 1 fewer predecessors from the beginning.
1836     if (stopped()) {
1837       if (TraceOptoParse)  tty->print_cr(", but path is dead and doesn't count");
1838       return;
1839     }
1840 
1841     // Make a region if we know there are multiple or unpredictable inputs.
1842     // (Also, if this is a plain fall-through, we might see another region,
1843     // which must not be allowed into this block's map.)
1844     if (pnum > PhiNode::Input         // Known multiple inputs.
1845         || target->is_handler()       // These have unpredictable inputs.
1846         || target->is_loop_head()     // Known multiple inputs
1847         || control()->is_Region()) {  // We must hide this guy.
1848 
1849       int current_bci = bci();
1850       set_parse_bci(target->start()); // Set target bci

1865       record_for_igvn(r);
1866       // zap all inputs to null for debugging (done in Node(uint) constructor)
1867       // for (int j = 1; j < edges+1; j++) { r->init_req(j, nullptr); }
1868       r->init_req(pnum, control());
1869       set_control(r);
1870       target->copy_irreducible_status_to(r, jvms());
1871       set_parse_bci(current_bci); // Restore bci
1872     }
1873 
1874     // Convert the existing Parser mapping into a mapping at this bci.
1875     store_state_to(target);
1876     assert(target->is_merged(), "do not come here twice");
1877 
1878   } else {                      // Prior mapping at this bci
1879     if (TraceOptoParse) {  tty->print(" with previous state"); }
1880 #ifdef ASSERT
1881     if (target->is_SEL_head()) {
1882       target->mark_merged_backedge(block());
1883     }
1884 #endif
1885 
1886     // We must not manufacture more phis if the target is already parsed.
1887     bool nophi = target->is_parsed();
1888 
1889     SafePointNode* newin = map();// Hang on to incoming mapping
1890     Block* save_block = block(); // Hang on to incoming block;
1891     load_state_from(target);    // Get prior mapping
1892 
1893     assert(newin->jvms()->locoff() == jvms()->locoff(), "JVMS layouts agree");
1894     assert(newin->jvms()->stkoff() == jvms()->stkoff(), "JVMS layouts agree");
1895     assert(newin->jvms()->monoff() == jvms()->monoff(), "JVMS layouts agree");
1896     assert(newin->jvms()->endoff() == jvms()->endoff(), "JVMS layouts agree");
1897 
1898     // Iterate over my current mapping and the old mapping.
1899     // Where different, insert Phi functions.
1900     // Use any existing Phi functions.
1901     assert(control()->is_Region(), "must be merging to a region");
1902     RegionNode* r = control()->as_Region();
1903 
1904     // Compute where to merge into
1905     // Merge incoming control path
1906     r->init_req(pnum, newin->control());
1907 
1908     if (pnum == 1) {            // Last merge for this Region?
1909       if (!block()->flow()->is_irreducible_loop_secondary_entry()) {
1910         Node* result = _gvn.transform(r);
1911         if (r != result && TraceOptoParse) {
1912           tty->print_cr("Block #%d replace %d with %d", block()->rpo(), r->_idx, result->_idx);
1913         }
1914       }
1915       record_for_igvn(r);
1916     }
1917 
1918     // Update all the non-control inputs to map:
1919     assert(TypeFunc::Parms == newin->jvms()->locoff(), "parser map should contain only youngest jvms");
1920     bool check_elide_phi = target->is_SEL_backedge(save_block);
1921     bool last_merge = (pnum == PhiNode::Input);
1922     for (uint j = 1; j < newin->req(); j++) {
1923       Node* m = map()->in(j);   // Current state of target.
1924       Node* n = newin->in(j);   // Incoming change to target state.
1925       Node* phi;
1926       if (m->is_Phi() && m->as_Phi()->region() == r) {
1927         phi = m;
1928       } else if (m->is_InlineType() && m->as_InlineType()->has_phi_inputs(r)) {
1929         phi = m;
1930       } else {
1931         phi = nullptr;
1932       }
1933       if (m != n) {             // Different; must merge
1934         switch (j) {
1935         // Frame pointer and Return Address never changes
1936         case TypeFunc::FramePtr:// Drop m, use the original value
1937         case TypeFunc::ReturnAdr:
1938           break;
1939         case TypeFunc::Memory:  // Merge inputs to the MergeMem node
1940           assert(phi == nullptr, "the merge contains phis, not vice versa");
1941           merge_memory_edges(n->as_MergeMem(), pnum, nophi);
1942           continue;
1943         default:                // All normal stuff
1944           if (phi == nullptr) {
1945             const JVMState* jvms = map()->jvms();
1946             if (EliminateNestedLocks &&
1947                 jvms->is_mon(j) && jvms->is_monitor_box(j)) {
1948               // BoxLock nodes are not commoning when EliminateNestedLocks is on.
1949               // Use old BoxLock node as merged box.
1950               assert(newin->jvms()->is_monitor_box(j), "sanity");
1951               // This assert also tests that nodes are BoxLock.
1952               assert(BoxLockNode::same_slot(n, m), "sanity");

1959                 // Incremental Inlining before EA and Macro nodes elimination.
1960                 //
1961                 // Incremental Inlining is executed after IGVN optimizations
1962                 // during which BoxLock can be marked as Coarsened.
1963                 old_box->set_coarsened(); // Verifies state
1964                 old_box->set_unbalanced();
1965               }
1966               C->gvn_replace_by(n, m);
1967             } else if (!check_elide_phi || !target->can_elide_SEL_phi(j)) {
1968               phi = ensure_phi(j, nophi);
1969             }
1970           }
1971           break;
1972         }
1973       }
1974       // At this point, n might be top if:
1975       //  - there is no phi (because TypeFlow detected a conflict), or
1976       //  - the corresponding control edges is top (a dead incoming path)
1977       // It is a bug if we create a phi which sees a garbage value on a live path.
1978 
1979       // Merging two inline types?
1980       if (phi != nullptr && phi->is_InlineType()) {
1981         // Reload current state because it may have been updated by ensure_phi
1982         assert(phi == map()->in(j), "unexpected value in map");
1983         assert(phi->as_InlineType()->has_phi_inputs(r), "");
1984         InlineTypeNode* vtm = phi->as_InlineType(); // Current inline type
1985         InlineTypeNode* vtn = n->as_InlineType(); // Incoming inline type
1986         assert(vtm == phi, "Inline type should have Phi input");
1987 
1988 #ifdef ASSERT
1989         if (TraceOptoParse) {
1990           tty->print_cr("\nMerging inline types");
1991           tty->print_cr("Current:");
1992           vtm->dump(2);
1993           tty->print_cr("Incoming:");
1994           vtn->dump(2);
1995           tty->cr();
1996         }
1997 #endif
1998         // Do the merge
1999         vtm->merge_with(&_gvn, vtn, pnum, last_merge);
2000         if (last_merge) {
2001           map()->set_req(j, _gvn.transform(vtm));
2002           record_for_igvn(vtm);
2003         }
2004       } else if (phi != nullptr) {
2005         assert(n != top() || r->in(pnum) == top(), "live value must not be garbage");
2006         assert(phi->as_Phi()->region() == r, "");
2007         phi->set_req(pnum, n);  // Then add 'n' to the merge
2008         if (last_merge) {
2009           // Last merge for this Phi.
2010           // So far, Phis have had a reasonable type from ciTypeFlow.
2011           // Now _gvn will join that with the meet of current inputs.
2012           // BOTTOM is never permissible here, 'cause pessimistically
2013           // Phis of pointers cannot lose the basic pointer type.
2014           DEBUG_ONLY(const Type* bt1 = phi->bottom_type());
2015           assert(bt1 != Type::BOTTOM, "should not be building conflict phis");
2016           map()->set_req(j, _gvn.transform(phi));
2017           DEBUG_ONLY(const Type* bt2 = phi->bottom_type());
2018           assert(bt2->higher_equal_speculative(bt1), "must be consistent with type-flow");
2019           record_for_igvn(phi);
2020         }
2021       }
2022     } // End of for all values to be merged
2023 
2024     if (last_merge && !r->in(0)) {         // The occasional useless Region

2025       assert(control() == r, "");
2026       set_control(r->nonnull_req());
2027     }
2028 
2029     map()->merge_replaced_nodes_with(newin);
2030 
2031     // newin has been subsumed into the lazy merge, and is now dead.
2032     set_block(save_block);
2033 
2034     stop();                     // done with this guy, for now
2035   }
2036 
2037   if (TraceOptoParse) {
2038     tty->print_cr(" on path %d", pnum);
2039   }
2040 
2041   // Done with this parser state.
2042   assert(stopped(), "");
2043 }
2044 

2156 
2157   // Add new path to the region.
2158   uint pnum = r->req();
2159   r->add_req(nullptr);
2160 
2161   for (uint i = 1; i < map->req(); i++) {
2162     Node* n = map->in(i);
2163     if (i == TypeFunc::Memory) {
2164       // Ensure a phi on all currently known memories.
2165       for (MergeMemStream mms(n->as_MergeMem()); mms.next_non_empty(); ) {
2166         Node* phi = mms.memory();
2167         if (phi->is_Phi() && phi->as_Phi()->region() == r) {
2168           assert(phi->req() == pnum, "must be same size as region");
2169           phi->add_req(nullptr);
2170         }
2171       }
2172     } else {
2173       if (n->is_Phi() && n->as_Phi()->region() == r) {
2174         assert(n->req() == pnum, "must be same size as region");
2175         n->add_req(nullptr);
2176       } else if (n->is_InlineType() && n->as_InlineType()->has_phi_inputs(r)) {
2177         n->as_InlineType()->add_new_path(r);
2178       }
2179     }
2180   }
2181 
2182   return pnum;
2183 }
2184 
2185 //------------------------------ensure_phi-------------------------------------
2186 // Turn the idx'th entry of the current map into a Phi
2187 Node* Parse::ensure_phi(int idx, bool nocreate) {
2188   SafePointNode* map = this->map();
2189   Node* region = map->control();
2190   assert(region->is_Region(), "");
2191 
2192   Node* o = map->in(idx);
2193   assert(o != nullptr, "");
2194 
2195   if (o == top())  return nullptr; // TOP always merges into TOP
2196 
2197   if (o->is_Phi() && o->as_Phi()->region() == region) {
2198     return o->as_Phi();
2199   }
2200   InlineTypeNode* vt = o->isa_InlineType();
2201   if (vt != nullptr && vt->has_phi_inputs(region)) {
2202     return vt;
2203   }
2204 
2205   // Now use a Phi here for merging
2206   assert(!nocreate, "Cannot build a phi for a block already parsed.");
2207   const JVMState* jvms = map->jvms();
2208   const Type* t = nullptr;
2209   if (jvms->is_loc(idx)) {
2210     t = block()->local_type_at(idx - jvms->locoff());
2211   } else if (jvms->is_stk(idx)) {
2212     t = block()->stack_type_at(idx - jvms->stkoff());
2213   } else if (jvms->is_mon(idx)) {
2214     assert(!jvms->is_monitor_box(idx), "no phis for boxes");
2215     t = TypeInstPtr::BOTTOM; // this is sufficient for a lock object
2216   } else if ((uint)idx < TypeFunc::Parms) {
2217     t = o->bottom_type();  // Type::RETURN_ADDRESS or such-like.
2218   } else {
2219     assert(false, "no type information for this phi");
2220   }
2221 
2222   // If the type falls to bottom, then this must be a local that
2223   // is already dead or is mixing ints and oops or some such.
2224   // Forcing it to top makes it go dead.
2225   if (t == Type::BOTTOM) {
2226     map->set_req(idx, top());
2227     return nullptr;
2228   }
2229 
2230   // Do not create phis for top either.
2231   // A top on a non-null control flow must be an unused even after the.phi.
2232   if (t == Type::TOP || t == Type::HALF) {
2233     map->set_req(idx, top());
2234     return nullptr;
2235   }
2236 
2237   if (vt != nullptr && t->is_inlinetypeptr()) {
2238     // Inline types are merged by merging their field values.
2239     // Create a cloned InlineTypeNode with phi inputs that
2240     // represents the merged inline type and update the map.
2241     vt = vt->clone_with_phis(&_gvn, region);
2242     map->set_req(idx, vt);
2243     return vt;
2244   } else {
2245     PhiNode* phi = PhiNode::make(region, o, t);
2246     gvn().set_type(phi, t);
2247     if (C->do_escape_analysis()) record_for_igvn(phi);
2248     map->set_req(idx, phi);
2249     return phi;
2250   }
2251 }
2252 
2253 //--------------------------ensure_memory_phi----------------------------------
2254 // Turn the idx'th slice of the current memory into a Phi
2255 PhiNode *Parse::ensure_memory_phi(int idx, bool nocreate) {
2256   MergeMemNode* mem = merged_memory();
2257   Node* region = control();
2258   assert(region->is_Region(), "");
2259 
2260   Node *o = (idx == Compile::AliasIdxBot)? mem->base_memory(): mem->memory_at(idx);
2261   assert(o != nullptr && o != top(), "");
2262 
2263   PhiNode* phi;
2264   if (o->is_Phi() && o->as_Phi()->region() == region) {
2265     phi = o->as_Phi();
2266     if (phi == mem->base_memory() && idx >= Compile::AliasIdxRaw) {
2267       // clone the shared base memory phi to make a new memory split
2268       assert(!nocreate, "Cannot build a phi for a block already parsed.");
2269       const Type* t = phi->bottom_type();
2270       const TypePtr* adr_type = C->get_adr_type(idx);

2360 // Add check to deoptimize once holder klass is fully initialized.
2361 void Parse::clinit_deopt() {
2362   assert(C->has_method(), "only for normal compilations");
2363   assert(depth() == 1, "only for main compiled method");
2364   assert(is_normal_parse(), "no barrier needed on osr entry");
2365   assert(!method()->holder()->is_not_initialized(), "initialization should have been started");
2366 
2367   set_parse_bci(0);
2368 
2369   Node* holder = makecon(TypeKlassPtr::make(method()->holder(), Type::trust_interfaces));
2370   guard_klass_being_initialized(holder);
2371 }
2372 
2373 //------------------------------return_current---------------------------------
2374 // Append current _map to _exit_return
2375 void Parse::return_current(Node* value) {
2376   if (method()->intrinsic_id() == vmIntrinsics::_Object_init) {
2377     call_register_finalizer();
2378   }
2379 
2380   // frame pointer is always same, already captured
2381   if (value != nullptr) {
2382     Node* phi = _exits.argument(0);
2383     const Type* return_type = phi->bottom_type();
2384     const TypeInstPtr* tr = return_type->isa_instptr();
2385     if ((tf()->returns_inline_type_as_fields() || (_caller->has_method() && !Compile::current()->inlining_incrementally())) &&
2386         return_type->is_inlinetypeptr()) {
2387       // Inline type is returned as fields, make sure it is scalarized
2388       if (!value->is_InlineType()) {
2389         value = InlineTypeNode::make_from_oop(this, value, return_type->inline_klass());
2390       }
2391       if (!_caller->has_method() || Compile::current()->inlining_incrementally()) {
2392         // Returning from root or an incrementally inlined method. Make sure all non-flat
2393         // fields are buffered and re-execute if allocation triggers deoptimization.
2394         PreserveReexecuteState preexecs(this);
2395         assert(tf()->returns_inline_type_as_fields(), "must be returned as fields");
2396         jvms()->set_should_reexecute(true);
2397         inc_sp(1);
2398         value = value->as_InlineType()->allocate_fields(this);
2399       }
2400     } else if (value->is_InlineType()) {
2401       // Inline type is returned as oop, make sure it is buffered and re-execute
2402       // if allocation triggers deoptimization.
2403       PreserveReexecuteState preexecs(this);
2404       jvms()->set_should_reexecute(true);
2405       inc_sp(1);
2406       value = value->as_InlineType()->buffer(this);
2407     }
2408     // ...else
2409     // If returning oops to an interface-return, there is a silent free
2410     // cast from oop to interface allowed by the Verifier. Make it explicit here.
2411     phi->add_req(value);
2412   }
2413 
2414   // Do not set_parse_bci, so that return goo is credited to the return insn.
2415   set_bci(InvocationEntryBci);
2416   if (method()->is_synchronized() && GenerateSynchronizationCode) {
2417     shared_unlock(_synch_lock->box_node(), _synch_lock->obj_node());
2418   }
2419   if (C->env()->dtrace_method_probes()) {
2420     make_dtrace_method_exit(method());
2421   }
2422 
2423   SafePointNode* exit_return = _exits.map();
2424   exit_return->in( TypeFunc::Control  )->add_req( control() );
2425   exit_return->in( TypeFunc::I_O      )->add_req( i_o    () );
2426   Node *mem = exit_return->in( TypeFunc::Memory   );
2427   for (MergeMemStream mms(mem->as_MergeMem(), merged_memory()); mms.next_non_empty2(); ) {
2428     if (mms.is_empty()) {
2429       // get a copy of the base memory, and patch just this one input
2430       const TypePtr* adr_type = mms.adr_type(C);
2431       Node* phi = mms.force_memory()->as_Phi()->slice_memory(adr_type);
2432       assert(phi->as_Phi()->region() == mms.base_memory()->in(0), "");
2433       gvn().set_type_bottom(phi);
2434       phi->del_req(phi->req()-1);  // prepare to re-patch
2435       mms.set_memory(phi);
2436     }
2437     mms.memory()->add_req(mms.memory2());
2438   }
2439 









2440   if (_first_return) {
2441     _exits.map()->transfer_replaced_nodes_from(map(), _new_idx);
2442     _first_return = false;
2443   } else {
2444     _exits.map()->merge_replaced_nodes_with(map());
2445   }
2446 
2447   stop_and_kill_map();          // This CFG path dies here
2448 }
2449 
2450 
2451 //------------------------------add_safepoint----------------------------------
2452 void Parse::add_safepoint() {
2453   uint parms = TypeFunc::Parms+1;
2454 
2455   // Clear out dead values from the debug info.
2456   kill_dead_locals();
2457 
2458   // Clone the JVM State
2459   SafePointNode *sfpnt = new SafePointNode(parms, nullptr);
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