1 /*
   2  * Copyright (c) 1997, 2026, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "ci/ciObjArrayKlass.hpp"
  26 #include "ci/ciSignature.hpp"
  27 #include "compiler/compileLog.hpp"
  28 #include "interpreter/linkResolver.hpp"
  29 #include "memory/resourceArea.hpp"
  30 #include "oops/method.hpp"
  31 #include "opto/addnode.hpp"
  32 #include "opto/c2compiler.hpp"
  33 #include "opto/castnode.hpp"
  34 #include "opto/convertnode.hpp"
  35 #include "opto/idealGraphPrinter.hpp"
  36 #include "opto/inlinetypenode.hpp"
  37 #include "opto/locknode.hpp"
  38 #include "opto/memnode.hpp"
  39 #include "opto/opaquenode.hpp"
  40 #include "opto/parse.hpp"
  41 #include "opto/rootnode.hpp"
  42 #include "opto/runtime.hpp"
  43 #include "opto/type.hpp"
  44 #include "runtime/arguments.hpp"
  45 #include "runtime/handles.inline.hpp"
  46 #include "runtime/safepointMechanism.hpp"
  47 #include "runtime/sharedRuntime.hpp"
  48 #include "utilities/bitMap.inline.hpp"
  49 #include "utilities/copy.hpp"
  50 
  51 // Static array so we can figure out which bytecodes stop us from compiling
  52 // the most. Some of the non-static variables are needed in bytecodeInfo.cpp
  53 // and eventually should be encapsulated in a proper class (gri 8/18/98).
  54 
  55 #ifndef PRODUCT
  56 uint nodes_created             = 0;
  57 uint methods_parsed            = 0;
  58 uint methods_seen              = 0;
  59 uint blocks_parsed             = 0;
  60 uint blocks_seen               = 0;
  61 
  62 uint explicit_null_checks_inserted = 0;
  63 uint explicit_null_checks_elided   = 0;
  64 uint all_null_checks_found         = 0;
  65 uint implicit_null_checks          = 0;
  66 
  67 bool Parse::BytecodeParseHistogram::_initialized = false;
  68 uint Parse::BytecodeParseHistogram::_bytecodes_parsed [Bytecodes::number_of_codes];
  69 uint Parse::BytecodeParseHistogram::_nodes_constructed[Bytecodes::number_of_codes];
  70 uint Parse::BytecodeParseHistogram::_nodes_transformed[Bytecodes::number_of_codes];
  71 uint Parse::BytecodeParseHistogram::_new_values       [Bytecodes::number_of_codes];
  72 
  73 //------------------------------print_statistics-------------------------------
  74 void Parse::print_statistics() {
  75   tty->print_cr("--- Compiler Statistics ---");
  76   tty->print("Methods seen: %u  Methods parsed: %u", methods_seen, methods_parsed);
  77   tty->print("  Nodes created: %u", nodes_created);
  78   tty->cr();
  79   if (methods_seen != methods_parsed) {
  80     tty->print_cr("Reasons for parse failures (NOT cumulative):");
  81   }
  82   tty->print_cr("Blocks parsed: %u  Blocks seen: %u", blocks_parsed, blocks_seen);
  83 
  84   if (explicit_null_checks_inserted) {
  85     tty->print_cr("%u original null checks - %u elided (%2u%%); optimizer leaves %u,",
  86                   explicit_null_checks_inserted, explicit_null_checks_elided,
  87                   (100*explicit_null_checks_elided)/explicit_null_checks_inserted,
  88                   all_null_checks_found);
  89   }
  90   if (all_null_checks_found) {
  91     tty->print_cr("%u made implicit (%2u%%)", implicit_null_checks,
  92                   (100*implicit_null_checks)/all_null_checks_found);
  93   }
  94   if (SharedRuntime::_implicit_null_throws) {
  95     tty->print_cr("%u implicit null exceptions at runtime",
  96                   SharedRuntime::_implicit_null_throws);
  97   }
  98 
  99   if (PrintParseStatistics && BytecodeParseHistogram::initialized()) {
 100     BytecodeParseHistogram::print();
 101   }
 102 }
 103 #endif
 104 
 105 //------------------------------ON STACK REPLACEMENT---------------------------
 106 
 107 // Construct a node which can be used to get incoming state for
 108 // on stack replacement.
 109 Node* Parse::fetch_interpreter_state(int index,
 110                                      const Type* type,
 111                                      Node* local_addrs) {
 112   BasicType bt = type->basic_type();
 113   if (type == TypePtr::NULL_PTR) {
 114     // Ptr types are mixed together with T_ADDRESS but nullptr is
 115     // really for T_OBJECT types so correct it.
 116     bt = T_OBJECT;
 117   }
 118   Node *mem = memory(Compile::AliasIdxRaw);
 119   Node *adr = basic_plus_adr(top(), local_addrs, -index*wordSize);
 120   Node *ctl = control();
 121 
 122   // Very similar to LoadNode::make, except we handle un-aligned longs and
 123   // doubles on Sparc.  Intel can handle them just fine directly.
 124   Node *l = nullptr;
 125   switch (bt) {                // Signature is flattened
 126   case T_INT:     l = new LoadINode(ctl, mem, adr, TypeRawPtr::BOTTOM, TypeInt::INT,        MemNode::unordered); break;
 127   case T_FLOAT:   l = new LoadFNode(ctl, mem, adr, TypeRawPtr::BOTTOM, Type::FLOAT,         MemNode::unordered); break;
 128   case T_ADDRESS: l = new LoadPNode(ctl, mem, adr, TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM,  MemNode::unordered); break;
 129   case T_OBJECT:  l = new LoadPNode(ctl, mem, adr, TypeRawPtr::BOTTOM, TypeInstPtr::BOTTOM, MemNode::unordered); break;
 130   case T_LONG:
 131   case T_DOUBLE: {
 132     // Since arguments are in reverse order, the argument address 'adr'
 133     // refers to the back half of the long/double.  Recompute adr.
 134     adr = basic_plus_adr(top(), local_addrs, -(index+1)*wordSize);
 135     if (Matcher::misaligned_doubles_ok) {
 136       l = (bt == T_DOUBLE)
 137         ? (Node*)new LoadDNode(ctl, mem, adr, TypeRawPtr::BOTTOM, Type::DOUBLE, MemNode::unordered)
 138         : (Node*)new LoadLNode(ctl, mem, adr, TypeRawPtr::BOTTOM, TypeLong::LONG, MemNode::unordered);
 139     } else {
 140       l = (bt == T_DOUBLE)
 141         ? (Node*)new LoadD_unalignedNode(ctl, mem, adr, TypeRawPtr::BOTTOM, MemNode::unordered)
 142         : (Node*)new LoadL_unalignedNode(ctl, mem, adr, TypeRawPtr::BOTTOM, MemNode::unordered);
 143     }
 144     break;
 145   }
 146   default: ShouldNotReachHere();
 147   }
 148   return _gvn.transform(l);
 149 }
 150 
 151 // Helper routine to prevent the interpreter from handing
 152 // unexpected typestate to an OSR method.
 153 // The Node l is a value newly dug out of the interpreter frame.
 154 // The type is the type predicted by ciTypeFlow.  Note that it is
 155 // not a general type, but can only come from Type::get_typeflow_type.
 156 // The safepoint is a map which will feed an uncommon trap.
 157 Node* Parse::check_interpreter_type(Node* l, const Type* type, const TypeKlassPtr* klass_type,
 158                                     SafePointNode* &bad_type_exit, bool is_early_larval) {
 159   const TypeOopPtr* tp = type->isa_oopptr();
 160 
 161   // TypeFlow may assert null-ness if a type appears unloaded.
 162   if (type == TypePtr::NULL_PTR ||
 163       (tp != nullptr && !tp->is_loaded())) {
 164     // Value must be null, not a real oop.
 165     Node* chk = _gvn.transform( new CmpPNode(l, null()) );
 166     Node* tst = _gvn.transform( new BoolNode(chk, BoolTest::eq) );
 167     IfNode* iff = create_and_map_if(control(), tst, PROB_MAX, COUNT_UNKNOWN);
 168     set_control(_gvn.transform( new IfTrueNode(iff) ));
 169     Node* bad_type = _gvn.transform( new IfFalseNode(iff) );
 170     bad_type_exit->control()->add_req(bad_type);
 171     l = null();
 172   }
 173 
 174   // Typeflow can also cut off paths from the CFG, based on
 175   // types which appear unloaded, or call sites which appear unlinked.
 176   // When paths are cut off, values at later merge points can rise
 177   // toward more specific classes.  Make sure these specific classes
 178   // are still in effect.
 179   if (tp != nullptr && !tp->is_same_java_type_as(TypeInstPtr::BOTTOM)) {
 180     // TypeFlow asserted a specific object type.  Value must have that type.
 181     Node* bad_type_ctrl = nullptr;
 182     if (tp->is_inlinetypeptr() && !tp->maybe_null()) {
 183       // Check inline types for null here to prevent checkcast from adding an
 184       // exception state before the bytecode entry (use 'bad_type_ctrl' instead).
 185       l = null_check_oop(l, &bad_type_ctrl);
 186       bad_type_exit->control()->add_req(bad_type_ctrl);
 187     }
 188 
 189     l = gen_checkcast(l, makecon(klass_type), &bad_type_ctrl, false, is_early_larval);
 190     bad_type_exit->control()->add_req(bad_type_ctrl);
 191   }
 192 
 193   assert(_gvn.type(l)->higher_equal(type), "must constrain OSR typestate");
 194   return l;
 195 }
 196 
 197 // Helper routine which sets up elements of the initial parser map when
 198 // performing a parse for on stack replacement.  Add values into map.
 199 // The only parameter contains the address of a interpreter arguments.
 200 void Parse::load_interpreter_state(Node* osr_buf) {
 201   int index;
 202   int max_locals = jvms()->loc_size();
 203   int max_stack  = jvms()->stk_size();
 204 
 205   // Mismatch between method and jvms can occur since map briefly held
 206   // an OSR entry state (which takes up one RawPtr word).
 207   assert(max_locals == method()->max_locals(), "sanity");
 208   assert(max_stack  >= method()->max_stack(),  "sanity");
 209   assert((int)jvms()->endoff() == TypeFunc::Parms + max_locals + max_stack, "sanity");
 210   assert((int)jvms()->endoff() == (int)map()->req(), "sanity");
 211 
 212   // Find the start block.
 213   Block* osr_block = start_block();
 214   assert(osr_block->start() == osr_bci(), "sanity");
 215 
 216   // Set initial BCI.
 217   set_parse_bci(osr_block->start());
 218 
 219   // Set initial stack depth.
 220   set_sp(osr_block->start_sp());
 221 
 222   // Check bailouts.  We currently do not perform on stack replacement
 223   // of loops in catch blocks or loops which branch with a non-empty stack.
 224   if (sp() != 0) {
 225     C->record_method_not_compilable("OSR starts with non-empty stack");
 226     return;
 227   }
 228   // Do not OSR inside finally clauses:
 229   if (osr_block->has_trap_at(osr_block->start())) {
 230     assert(false, "OSR starts with an immediate trap");
 231     C->record_method_not_compilable("OSR starts with an immediate trap");
 232     return;
 233   }
 234 
 235   // Commute monitors from interpreter frame to compiler frame.
 236   assert(jvms()->monitor_depth() == 0, "should be no active locks at beginning of osr");
 237   int mcnt = osr_block->flow()->monitor_count();
 238   Node *monitors_addr = basic_plus_adr(top(), osr_buf, (max_locals+mcnt*2-1)*wordSize);
 239   for (index = 0; index < mcnt; index++) {
 240     // Make a BoxLockNode for the monitor.
 241     BoxLockNode* osr_box = new BoxLockNode(next_monitor());
 242     // Check for bailout after new BoxLockNode
 243     if (failing()) { return; }
 244 
 245     // This OSR locking region is unbalanced because it does not have Lock node:
 246     // locking was done in Interpreter.
 247     // This is similar to Coarsened case when Lock node is eliminated
 248     // and as result the region is marked as Unbalanced.
 249 
 250     // Emulate Coarsened state transition from Regular to Unbalanced.
 251     osr_box->set_coarsened();
 252     osr_box->set_unbalanced();
 253 
 254     Node* box = _gvn.transform(osr_box);
 255 
 256     // Displaced headers and locked objects are interleaved in the
 257     // temp OSR buffer.  We only copy the locked objects out here.
 258     // Fetch the locked object from the OSR temp buffer and copy to our fastlock node.
 259     Node* lock_object = fetch_interpreter_state(index*2, Type::get_const_basic_type(T_OBJECT), monitors_addr);
 260     // Try and copy the displaced header to the BoxNode
 261     Node* displaced_hdr = fetch_interpreter_state((index*2) + 1, Type::get_const_basic_type(T_ADDRESS), monitors_addr);
 262 
 263     store_to_memory(control(), box, displaced_hdr, T_ADDRESS, MemNode::unordered);
 264 
 265     // Build a bogus FastLockNode (no code will be generated) and push the
 266     // monitor into our debug info.
 267     const FastLockNode *flock = _gvn.transform(new FastLockNode( nullptr, lock_object, box ))->as_FastLock();
 268     map()->push_monitor(flock);
 269 
 270     // If the lock is our method synchronization lock, tuck it away in
 271     // _sync_lock for return and rethrow exit paths.
 272     if (index == 0 && method()->is_synchronized()) {
 273       _synch_lock = flock;
 274     }
 275   }
 276 
 277   // Use the raw liveness computation to make sure that unexpected
 278   // values don't propagate into the OSR frame.
 279   MethodLivenessResult live_locals = method()->liveness_at_bci(osr_bci());
 280   if (!live_locals.is_valid()) {
 281     // Degenerate or breakpointed method.
 282     assert(false, "OSR in empty or breakpointed method");
 283     C->record_method_not_compilable("OSR in empty or breakpointed method");
 284     return;
 285   }
 286 
 287   // Extract the needed locals from the interpreter frame.
 288   Node *locals_addr = basic_plus_adr(top(), osr_buf, (max_locals-1)*wordSize);
 289 
 290   // find all the locals that the interpreter thinks contain live oops
 291   const ResourceBitMap live_oops = method()->live_local_oops_at_bci(osr_bci());
 292   for (index = 0; index < max_locals; index++) {
 293 
 294     if (!live_locals.at(index)) {
 295       continue;
 296     }
 297 
 298     const Type *type = osr_block->local_type_at(index);
 299 
 300     if (type->isa_oopptr() != nullptr) {
 301 
 302       // 6403625: Verify that the interpreter oopMap thinks that the oop is live
 303       // else we might load a stale oop if the MethodLiveness disagrees with the
 304       // result of the interpreter. If the interpreter says it is dead we agree
 305       // by making the value go to top.
 306       //
 307 
 308       if (!live_oops.at(index)) {
 309         if (C->log() != nullptr) {
 310           C->log()->elem("OSR_mismatch local_index='%d'",index);
 311         }
 312         set_local(index, null());
 313         // and ignore it for the loads
 314         continue;
 315       }
 316     }
 317 
 318     // Filter out TOP, HALF, and BOTTOM.  (Cf. ensure_phi.)
 319     if (type == Type::TOP || type == Type::HALF) {
 320       continue;
 321     }
 322     // If the type falls to bottom, then this must be a local that
 323     // is mixing ints and oops or some such.  Forcing it to top
 324     // makes it go dead.
 325     if (type == Type::BOTTOM) {
 326       continue;
 327     }
 328     // Construct code to access the appropriate local.
 329     Node* value = fetch_interpreter_state(index, type, locals_addr);
 330     set_local(index, value);
 331   }
 332 
 333   // Extract the needed stack entries from the interpreter frame.
 334   for (index = 0; index < sp(); index++) {
 335     const Type *type = osr_block->stack_type_at(index);
 336     if (type != Type::TOP) {
 337       // Currently the compiler bails out when attempting to on stack replace
 338       // at a bci with a non-empty stack.  We should not reach here.
 339       ShouldNotReachHere();
 340     }
 341   }
 342 
 343   // End the OSR migration
 344   make_runtime_call(RC_LEAF, OptoRuntime::osr_end_Type(),
 345                     CAST_FROM_FN_PTR(address, SharedRuntime::OSR_migration_end),
 346                     "OSR_migration_end", TypeRawPtr::BOTTOM,
 347                     osr_buf);
 348 
 349   // Now that the interpreter state is loaded, make sure it will match
 350   // at execution time what the compiler is expecting now:
 351   SafePointNode* bad_type_exit = clone_map();
 352   bad_type_exit->set_control(new RegionNode(1));
 353 
 354   assert(osr_block->flow()->jsrs()->size() == 0, "should be no jsrs live at osr point");
 355   for (index = 0; index < max_locals; index++) {
 356     if (stopped())  break;
 357     Node* l = local(index);
 358     if (l->is_top())  continue;  // nothing here
 359     const Type *type = osr_block->local_type_at(index);
 360     if (type->isa_oopptr() != nullptr) {
 361       if (!live_oops.at(index)) {
 362         // skip type check for dead oops
 363         continue;
 364       }
 365     }
 366     if (osr_block->flow()->local_type_at(index)->is_return_address()) {
 367       // In our current system it's illegal for jsr addresses to be
 368       // live into an OSR entry point because the compiler performs
 369       // inlining of jsrs.  ciTypeFlow has a bailout that detect this
 370       // case and aborts the compile if addresses are live into an OSR
 371       // entry point.  Because of that we can assume that any address
 372       // locals at the OSR entry point are dead.  Method liveness
 373       // isn't precise enough to figure out that they are dead in all
 374       // cases so simply skip checking address locals all
 375       // together. Any type check is guaranteed to fail since the
 376       // interpreter type is the result of a load which might have any
 377       // value and the expected type is a constant.
 378       continue;
 379     }
 380     const TypeKlassPtr* klass_type = nullptr;
 381     if (type->isa_oopptr()) {
 382       klass_type = TypeKlassPtr::make(osr_block->flow()->local_type_at(index)->unwrap()->as_klass(), Type::ignore_interfaces);
 383       klass_type = klass_type->try_improve();
 384     }
 385     bool is_early_larval = osr_block->flow()->local_type_at(index)->is_early_larval();
 386     set_local(index, check_interpreter_type(l, type, klass_type, bad_type_exit, is_early_larval));
 387   }
 388 
 389   for (index = 0; index < sp(); index++) {
 390     if (stopped())  break;
 391     Node* l = stack(index);
 392     if (l->is_top())  continue;  // nothing here
 393     const Type* type = osr_block->stack_type_at(index);
 394     const TypeKlassPtr* klass_type = nullptr;
 395     if (type->isa_oopptr()) {
 396       klass_type = TypeKlassPtr::make(osr_block->flow()->stack_type_at(index)->unwrap()->as_klass(), Type::ignore_interfaces);
 397       klass_type = klass_type->try_improve();
 398     }
 399     bool is_early_larval = osr_block->flow()->stack_type_at(index)->is_early_larval();
 400     set_stack(index, check_interpreter_type(l, type, klass_type, bad_type_exit, is_early_larval));
 401   }
 402 
 403   if (bad_type_exit->control()->req() > 1) {
 404     // Build an uncommon trap here, if any inputs can be unexpected.
 405     bad_type_exit->set_control(_gvn.transform( bad_type_exit->control() ));
 406     record_for_igvn(bad_type_exit->control());
 407     SafePointNode* types_are_good = map();
 408     set_map(bad_type_exit);
 409     // The unexpected type happens because a new edge is active
 410     // in the CFG, which typeflow had previously ignored.
 411     // E.g., Object x = coldAtFirst() && notReached()? "str": new Integer(123).
 412     // This x will be typed as Integer if notReached is not yet linked.
 413     // It could also happen due to a problem in ciTypeFlow analysis.
 414     uncommon_trap(Deoptimization::Reason_constraint,
 415                   Deoptimization::Action_reinterpret);
 416     set_map(types_are_good);
 417   }
 418 }
 419 
 420 //------------------------------Parse------------------------------------------
 421 // Main parser constructor.
 422 Parse::Parse(JVMState* caller, ciMethod* parse_method, float expected_uses)
 423   : _exits(caller)
 424 {
 425   // Init some variables
 426   _caller = caller;
 427   _method = parse_method;
 428   _expected_uses = expected_uses;
 429   _depth = 1 + (caller->has_method() ? caller->depth() : 0);
 430   _wrote_final = false;
 431   _wrote_volatile = false;
 432   _wrote_stable = false;
 433   _wrote_fields = false;
 434   _alloc_with_final_or_stable = nullptr;
 435   _block = nullptr;
 436   _first_return = true;
 437   _replaced_nodes_for_exceptions = false;
 438   _new_idx = C->unique();
 439   DEBUG_ONLY(_entry_bci = UnknownBci);
 440   DEBUG_ONLY(_block_count = -1);
 441   DEBUG_ONLY(_blocks = (Block*)-1);
 442 #ifndef PRODUCT
 443   if (PrintCompilation || PrintOpto) {
 444     // Make sure I have an inline tree, so I can print messages about it.
 445     InlineTree::find_subtree_from_root(C->ilt(), caller, parse_method);
 446   }
 447   _max_switch_depth = 0;
 448   _est_switch_depth = 0;
 449 #endif
 450 
 451   if (parse_method->has_reserved_stack_access()) {
 452     C->set_has_reserved_stack_access(true);
 453   }
 454 
 455   if (parse_method->is_synchronized() || parse_method->has_monitor_bytecodes()) {
 456     C->set_has_monitors(true);
 457   }
 458 
 459   if (parse_method->is_scoped()) {
 460     C->set_has_scoped_access(true);
 461   }
 462 
 463   _iter.reset_to_method(method());
 464   C->set_has_loops(C->has_loops() || method()->has_loops());
 465 
 466   if (_expected_uses <= 0) {
 467     _prof_factor = 1;
 468   } else {
 469     float prof_total = parse_method->interpreter_invocation_count();
 470     if (prof_total <= _expected_uses) {
 471       _prof_factor = 1;
 472     } else {
 473       _prof_factor = _expected_uses / prof_total;
 474     }
 475   }
 476 
 477   CompileLog* log = C->log();
 478   if (log != nullptr) {
 479     log->begin_head("parse method='%d' uses='%f'",
 480                     log->identify(parse_method), expected_uses);
 481     if (depth() == 1 && C->is_osr_compilation()) {
 482       log->print(" osr_bci='%d'", C->entry_bci());
 483     }
 484     log->stamp();
 485     log->end_head();
 486   }
 487 
 488   // Accumulate deoptimization counts.
 489   // (The range_check and store_check counts are checked elsewhere.)
 490   ciMethodData* md = method()->method_data();
 491   for (uint reason = 0; reason < md->trap_reason_limit(); reason++) {
 492     uint md_count = md->trap_count(reason);
 493     if (md_count != 0) {
 494       if (md_count >= md->trap_count_limit()) {
 495         md_count = md->trap_count_limit() + md->overflow_trap_count();
 496       }
 497       uint total_count = C->trap_count(reason);
 498       uint old_count   = total_count;
 499       total_count += md_count;
 500       // Saturate the add if it overflows.
 501       if (total_count < old_count || total_count < md_count)
 502         total_count = (uint)-1;
 503       C->set_trap_count(reason, total_count);
 504       if (log != nullptr)
 505         log->elem("observe trap='%s' count='%d' total='%d'",
 506                   Deoptimization::trap_reason_name(reason),
 507                   md_count, total_count);
 508     }
 509   }
 510   // Accumulate total sum of decompilations, also.
 511   C->set_decompile_count(C->decompile_count() + md->decompile_count());
 512 
 513   if (log != nullptr && method()->has_exception_handlers()) {
 514     log->elem("observe that='has_exception_handlers'");
 515   }
 516 
 517   assert(InlineTree::check_can_parse(method()) == nullptr, "Can not parse this method, cutout earlier");
 518   assert(method()->has_balanced_monitors(), "Can not parse unbalanced monitors, cutout earlier");
 519 
 520   // Always register dependence if JVMTI is enabled, because
 521   // either breakpoint setting or hotswapping of methods may
 522   // cause deoptimization.
 523   if (C->env()->jvmti_can_hotswap_or_post_breakpoint()) {
 524     C->dependencies()->assert_evol_method(method());
 525   }
 526 
 527   NOT_PRODUCT(methods_seen++);
 528 
 529   // Do some special top-level things.
 530   if (depth() == 1 && C->is_osr_compilation()) {
 531     _tf = C->tf();     // the OSR entry type is different
 532     _entry_bci = C->entry_bci();
 533     _flow = method()->get_osr_flow_analysis(osr_bci());
 534   } else {
 535     _tf = TypeFunc::make(method());
 536     _entry_bci = InvocationEntryBci;
 537     _flow = method()->get_flow_analysis();
 538   }
 539 
 540   if (_flow->failing()) {
 541     // TODO Adding a trap due to an unloaded return type in ciTypeFlow::StateVector::do_invoke
 542     // can lead to this. Re-enable once 8284443 is fixed.
 543     //assert(false, "type flow analysis failed during parsing");
 544     C->record_method_not_compilable(_flow->failure_reason());
 545 #ifndef PRODUCT
 546       if (PrintOpto && (Verbose || WizardMode)) {
 547         if (is_osr_parse()) {
 548           tty->print_cr("OSR @%d type flow bailout: %s", _entry_bci, _flow->failure_reason());
 549         } else {
 550           tty->print_cr("type flow bailout: %s", _flow->failure_reason());
 551         }
 552         if (Verbose) {
 553           method()->print();
 554           method()->print_codes();
 555           _flow->print();
 556         }
 557       }
 558 #endif
 559   }
 560 
 561 #ifdef ASSERT
 562   if (depth() == 1) {
 563     assert(C->is_osr_compilation() == this->is_osr_parse(), "OSR in sync");
 564   } else {
 565     assert(!this->is_osr_parse(), "no recursive OSR");
 566   }
 567 #endif
 568 
 569 #ifndef PRODUCT
 570   if (_flow->has_irreducible_entry()) {
 571     C->set_parsed_irreducible_loop(true);
 572   }
 573 
 574   methods_parsed++;
 575   // add method size here to guarantee that inlined methods are added too
 576   if (CITime)
 577     _total_bytes_compiled += method()->code_size();
 578 
 579   show_parse_info();
 580 #endif
 581 
 582   if (failing()) {
 583     if (log)  log->done("parse");
 584     return;
 585   }
 586 
 587   gvn().transform(top());
 588 
 589   // Import the results of the ciTypeFlow.
 590   init_blocks();
 591 
 592   // Merge point for all normal exits
 593   build_exits();
 594 
 595   // Setup the initial JVM state map.
 596   SafePointNode* entry_map = create_entry_map();
 597 
 598   // Check for bailouts during map initialization
 599   if (failing() || entry_map == nullptr) {
 600     if (log)  log->done("parse");
 601     return;
 602   }
 603 
 604   Node_Notes* caller_nn = C->default_node_notes();
 605   // Collect debug info for inlined calls unless -XX:-DebugInlinedCalls.
 606   if (DebugInlinedCalls || depth() == 1) {
 607     C->set_default_node_notes(make_node_notes(caller_nn));
 608   }
 609 
 610   if (is_osr_parse()) {
 611     Node* osr_buf = entry_map->in(TypeFunc::Parms+0);
 612     entry_map->set_req(TypeFunc::Parms+0, top());
 613     set_map(entry_map);
 614     load_interpreter_state(osr_buf);
 615   } else {
 616     set_map(entry_map);
 617     do_method_entry();
 618   }
 619 
 620   if (depth() == 1 && !failing()) {
 621     if (C->clinit_barrier_on_entry()) {
 622       // Add check to deoptimize the nmethod once the holder class is fully initialized
 623       clinit_deopt();
 624     }
 625   }
 626 
 627   // Check for bailouts during method entry.
 628   if (failing()) {
 629     if (log)  log->done("parse");
 630     C->set_default_node_notes(caller_nn);
 631     return;
 632   }
 633 
 634   entry_map = map();  // capture any changes performed by method setup code
 635   assert(jvms()->endoff() == map()->req(), "map matches JVMS layout");
 636 
 637   // We begin parsing as if we have just encountered a jump to the
 638   // method entry.
 639   Block* entry_block = start_block();
 640   assert(entry_block->start() == (is_osr_parse() ? osr_bci() : 0), "");
 641   set_map_clone(entry_map);
 642   merge_common(entry_block, entry_block->next_path_num());
 643 
 644 #ifndef PRODUCT
 645   BytecodeParseHistogram *parse_histogram_obj = new (C->env()->arena()) BytecodeParseHistogram(this, C);
 646   set_parse_histogram( parse_histogram_obj );
 647 #endif
 648 
 649   // Parse all the basic blocks.
 650   do_all_blocks();
 651 
 652   // Check for bailouts during conversion to graph
 653   if (failing()) {
 654     if (log)  log->done("parse");
 655     return;
 656   }
 657 
 658   // Fix up all exiting control flow.
 659   set_map(entry_map);
 660   do_exits();
 661 
 662   // Only reset this now, to make sure that debug information emitted
 663   // for exiting control flow still refers to the inlined method.
 664   C->set_default_node_notes(caller_nn);
 665 
 666   if (log)  log->done("parse nodes='%d' live='%d' memory='%zu'",
 667                       C->unique(), C->live_nodes(), C->node_arena()->used());
 668 }
 669 
 670 //---------------------------do_all_blocks-------------------------------------
 671 void Parse::do_all_blocks() {
 672   bool has_irreducible = flow()->has_irreducible_entry();
 673 
 674   // Walk over all blocks in Reverse Post-Order.
 675   while (true) {
 676     bool progress = false;
 677     for (int rpo = 0; rpo < block_count(); rpo++) {
 678       Block* block = rpo_at(rpo);
 679 
 680       if (block->is_parsed()) continue;
 681 
 682       if (!block->is_merged()) {
 683         // Dead block, no state reaches this block
 684         continue;
 685       }
 686 
 687       // Prepare to parse this block.
 688       load_state_from(block);
 689 
 690       if (stopped()) {
 691         // Block is dead.
 692         continue;
 693       }
 694 
 695       NOT_PRODUCT(blocks_parsed++);
 696 
 697       progress = true;
 698       if (block->is_loop_head() || block->is_handler() || (has_irreducible && !block->is_ready())) {
 699         // Not all preds have been parsed.  We must build phis everywhere.
 700         // (Note that dead locals do not get phis built, ever.)
 701         ensure_phis_everywhere();
 702 
 703         if (block->is_SEL_head()) {
 704           // Add predicate to single entry (not irreducible) loop head.
 705           assert(!block->has_merged_backedge(), "only entry paths should be merged for now");
 706           // Predicates may have been added after a dominating if
 707           if (!block->has_predicates()) {
 708             // Need correct bci for predicate.
 709             // It is fine to set it here since do_one_block() will set it anyway.
 710             set_parse_bci(block->start());
 711             add_parse_predicates();
 712           }
 713           // Add new region for back branches.
 714           int edges = block->pred_count() - block->preds_parsed() + 1; // +1 for original region
 715           RegionNode *r = new RegionNode(edges+1);
 716           _gvn.set_type(r, Type::CONTROL);
 717           record_for_igvn(r);
 718           r->init_req(edges, control());
 719           set_control(r);
 720           block->copy_irreducible_status_to(r, jvms());
 721           // Add new phis.
 722           ensure_phis_everywhere();
 723         }
 724 
 725         // Leave behind an undisturbed copy of the map, for future merges.
 726         set_map(clone_map());
 727       }
 728 
 729       if (control()->is_Region() && !block->is_loop_head() && !has_irreducible && !block->is_handler()) {
 730         // In the absence of irreducible loops, the Region and Phis
 731         // associated with a merge that doesn't involve a backedge can
 732         // be simplified now since the RPO parsing order guarantees
 733         // that any path which was supposed to reach here has already
 734         // been parsed or must be dead.
 735         Node* c = control();
 736         Node* result = _gvn.transform(control());
 737         if (c != result && TraceOptoParse) {
 738           tty->print_cr("Block #%d replace %d with %d", block->rpo(), c->_idx, result->_idx);
 739         }
 740         if (result != top()) {
 741           record_for_igvn(result);
 742         }
 743       }
 744 
 745       // Parse the block.
 746       do_one_block();
 747 
 748       // Check for bailouts.
 749       if (failing())  return;
 750     }
 751 
 752     // with irreducible loops multiple passes might be necessary to parse everything
 753     if (!has_irreducible || !progress) {
 754       break;
 755     }
 756   }
 757 
 758 #ifndef PRODUCT
 759   blocks_seen += block_count();
 760 
 761   // Make sure there are no half-processed blocks remaining.
 762   // Every remaining unprocessed block is dead and may be ignored now.
 763   for (int rpo = 0; rpo < block_count(); rpo++) {
 764     Block* block = rpo_at(rpo);
 765     if (!block->is_parsed()) {
 766       if (TraceOptoParse) {
 767         tty->print_cr("Skipped dead block %d at bci:%d", rpo, block->start());
 768       }
 769       assert(!block->is_merged(), "no half-processed blocks");
 770     }
 771   }
 772 #endif
 773 }
 774 
 775 static Node* mask_int_value(Node* v, BasicType bt, PhaseGVN* gvn) {
 776   switch (bt) {
 777   case T_BYTE:
 778     v = gvn->transform(new LShiftINode(v, gvn->intcon(24)));
 779     v = gvn->transform(new RShiftINode(v, gvn->intcon(24)));
 780     break;
 781   case T_SHORT:
 782     v = gvn->transform(new LShiftINode(v, gvn->intcon(16)));
 783     v = gvn->transform(new RShiftINode(v, gvn->intcon(16)));
 784     break;
 785   case T_CHAR:
 786     v = gvn->transform(new AndINode(v, gvn->intcon(0xFFFF)));
 787     break;
 788   case T_BOOLEAN:
 789     v = gvn->transform(new AndINode(v, gvn->intcon(0x1)));
 790     break;
 791   default:
 792     break;
 793   }
 794   return v;
 795 }
 796 
 797 //-------------------------------build_exits----------------------------------
 798 // Build normal and exceptional exit merge points.
 799 void Parse::build_exits() {
 800   // make a clone of caller to prevent sharing of side-effects
 801   _exits.set_map(_exits.clone_map());
 802   _exits.clean_stack(_exits.sp());
 803   _exits.sync_jvms();
 804 
 805   RegionNode* region = new RegionNode(1);
 806   record_for_igvn(region);
 807   gvn().set_type_bottom(region);
 808   _exits.set_control(region);
 809 
 810   // Note:  iophi and memphi are not transformed until do_exits.
 811   Node* iophi  = new PhiNode(region, Type::ABIO);
 812   Node* memphi = new PhiNode(region, Type::MEMORY, TypePtr::BOTTOM);
 813   gvn().set_type_bottom(iophi);
 814   gvn().set_type_bottom(memphi);
 815   _exits.set_i_o(iophi);
 816   _exits.set_all_memory(memphi);
 817 
 818   // Add a return value to the exit state.  (Do not push it yet.)
 819   if (tf()->range_sig()->cnt() > TypeFunc::Parms) {
 820     const Type* ret_type = tf()->range_sig()->field_at(TypeFunc::Parms);
 821     if (ret_type->isa_int()) {
 822       BasicType ret_bt = method()->return_type()->basic_type();
 823       if (ret_bt == T_BOOLEAN ||
 824           ret_bt == T_CHAR ||
 825           ret_bt == T_BYTE ||
 826           ret_bt == T_SHORT) {
 827         ret_type = TypeInt::INT;
 828       }
 829     }
 830 
 831     // Don't "bind" an unloaded return klass to the ret_phi. If the klass
 832     // becomes loaded during the subsequent parsing, the loaded and unloaded
 833     // types will not join when we transform and push in do_exits().
 834     const TypeOopPtr* ret_oop_type = ret_type->isa_oopptr();
 835     if (ret_oop_type && !ret_oop_type->is_loaded()) {
 836       ret_type = TypeOopPtr::BOTTOM;
 837     }
 838     int         ret_size = type2size[ret_type->basic_type()];
 839     Node*       ret_phi  = new PhiNode(region, ret_type);
 840     gvn().set_type_bottom(ret_phi);
 841     _exits.ensure_stack(ret_size);
 842     assert((int)(tf()->range_sig()->cnt() - TypeFunc::Parms) == ret_size, "good tf range");
 843     assert(method()->return_type()->size() == ret_size, "tf agrees w/ method");
 844     _exits.set_argument(0, ret_phi);  // here is where the parser finds it
 845     // Note:  ret_phi is not yet pushed, until do_exits.
 846   }
 847 }
 848 
 849 //----------------------------build_start_state-------------------------------
 850 // Construct a state which contains only the incoming arguments from an
 851 // unknown caller.  The method & bci will be null & InvocationEntryBci.
 852 JVMState* Compile::build_start_state(StartNode* start, const TypeFunc* tf) {
 853   int        arg_size = tf->domain_sig()->cnt();
 854   int        max_size = MAX2(arg_size, (int)tf->range_cc()->cnt());
 855   JVMState*  jvms     = new (this) JVMState(max_size - TypeFunc::Parms);
 856   SafePointNode* map  = new SafePointNode(max_size, jvms);
 857   jvms->set_map(map);
 858   record_for_igvn(map);
 859   assert(arg_size == TypeFunc::Parms + (is_osr_compilation() ? 1 : method()->arg_size()), "correct arg_size");
 860   Node_Notes* old_nn = default_node_notes();
 861   if (old_nn != nullptr && has_method()) {
 862     Node_Notes* entry_nn = old_nn->clone(this);
 863     JVMState* entry_jvms = new(this) JVMState(method(), old_nn->jvms());
 864     entry_jvms->set_offsets(0);
 865     entry_jvms->set_bci(entry_bci());
 866     entry_nn->set_jvms(entry_jvms);
 867     set_default_node_notes(entry_nn);
 868   }
 869   PhaseGVN& gvn = *initial_gvn();
 870   uint i = 0;
 871   int arg_num = 0;
 872   for (uint j = 0; i < (uint)arg_size; i++) {
 873     const Type* t = tf->domain_sig()->field_at(i);
 874     Node* parm = nullptr;
 875     if (t->is_inlinetypeptr() && method()->is_scalarized_arg(arg_num)) {
 876       // Inline type arguments are not passed by reference: we get an argument per
 877       // field of the inline type. Build InlineTypeNodes from the inline type arguments.
 878       GraphKit kit(jvms, &gvn);
 879       kit.set_control(map->control());
 880       Node* old_mem = map->memory();
 881       // Use immutable memory for inline type loads and restore it below
 882       kit.set_all_memory(C->immutable_memory());
 883       parm = InlineTypeNode::make_from_multi(&kit, start, t->inline_klass(), j, /* in= */ true, /* null_free= */ !t->maybe_null());
 884       map->set_control(kit.control());
 885       map->set_memory(old_mem);
 886     } else {
 887       parm = gvn.transform(new ParmNode(start, j++));
 888     }
 889     map->init_req(i, parm);
 890     // Record all these guys for later GVN.
 891     record_for_igvn(parm);
 892     if (i >= TypeFunc::Parms && t != Type::HALF) {
 893       arg_num++;
 894     }
 895   }
 896   for (; i < map->req(); i++) {
 897     map->init_req(i, top());
 898   }
 899   assert(jvms->argoff() == TypeFunc::Parms, "parser gets arguments here");
 900   set_default_node_notes(old_nn);
 901   return jvms;
 902 }
 903 
 904 //-----------------------------make_node_notes---------------------------------
 905 Node_Notes* Parse::make_node_notes(Node_Notes* caller_nn) {
 906   if (caller_nn == nullptr)  return nullptr;
 907   Node_Notes* nn = caller_nn->clone(C);
 908   JVMState* caller_jvms = nn->jvms();
 909   JVMState* jvms = new (C) JVMState(method(), caller_jvms);
 910   jvms->set_offsets(0);
 911   jvms->set_bci(_entry_bci);
 912   nn->set_jvms(jvms);
 913   return nn;
 914 }
 915 
 916 
 917 //--------------------------return_values--------------------------------------
 918 void Compile::return_values(JVMState* jvms) {
 919   GraphKit kit(jvms);
 920   Node* ret = new ReturnNode(TypeFunc::Parms,
 921                              kit.control(),
 922                              kit.i_o(),
 923                              kit.reset_memory(),
 924                              kit.frameptr(),
 925                              kit.returnadr());
 926   // Add zero or 1 return values
 927   int ret_size = tf()->range_sig()->cnt() - TypeFunc::Parms;
 928   if (ret_size > 0) {
 929     kit.inc_sp(-ret_size);  // pop the return value(s)
 930     kit.sync_jvms();
 931     Node* res = kit.argument(0);
 932     if (tf()->returns_inline_type_as_fields()) {
 933       // Multiple return values (inline type fields): add as many edges
 934       // to the Return node as returned values.
 935       InlineTypeNode* vt = res->as_InlineType();
 936       ret->add_req_batch(nullptr, tf()->range_cc()->cnt() - TypeFunc::Parms);
 937       if (vt->is_allocated(&kit.gvn()) && !StressCallingConvention) {
 938         ret->init_req(TypeFunc::Parms, vt);
 939       } else {
 940         // Return the tagged klass pointer to signal scalarization to the caller
 941         Node* tagged_klass = vt->tagged_klass(kit.gvn());
 942         // Return null if the inline type is null (null marker field is not set)
 943         Node* conv   = kit.gvn().transform(new ConvI2LNode(vt->get_null_marker()));
 944         Node* shl    = kit.gvn().transform(new LShiftLNode(conv, kit.intcon(63)));
 945         Node* shr    = kit.gvn().transform(new RShiftLNode(shl, kit.intcon(63)));
 946         tagged_klass = kit.gvn().transform(new AndLNode(tagged_klass, shr));
 947         ret->init_req(TypeFunc::Parms, tagged_klass);
 948       }
 949       uint idx = TypeFunc::Parms + 1;
 950       vt->pass_fields(&kit, ret, idx, false, false);
 951     } else {
 952       ret->add_req(res);
 953       // Note:  The second dummy edge is not needed by a ReturnNode.
 954     }
 955   }
 956   // bind it to root
 957   root()->add_req(ret);
 958   record_for_igvn(ret);
 959   initial_gvn()->transform(ret);
 960 }
 961 
 962 //------------------------rethrow_exceptions-----------------------------------
 963 // Bind all exception states in the list into a single RethrowNode.
 964 void Compile::rethrow_exceptions(JVMState* jvms) {
 965   GraphKit kit(jvms);
 966   if (!kit.has_exceptions())  return;  // nothing to generate
 967   // Load my combined exception state into the kit, with all phis transformed:
 968   SafePointNode* ex_map = kit.combine_and_pop_all_exception_states();
 969   Node* ex_oop = kit.use_exception_state(ex_map);
 970   RethrowNode* exit = new RethrowNode(kit.control(),
 971                                       kit.i_o(), kit.reset_memory(),
 972                                       kit.frameptr(), kit.returnadr(),
 973                                       // like a return but with exception input
 974                                       ex_oop);
 975   // bind to root
 976   root()->add_req(exit);
 977   record_for_igvn(exit);
 978   initial_gvn()->transform(exit);
 979 }
 980 
 981 //---------------------------do_exceptions-------------------------------------
 982 // Process exceptions arising from the current bytecode.
 983 // Send caught exceptions to the proper handler within this method.
 984 // Unhandled exceptions feed into _exit.
 985 void Parse::do_exceptions() {
 986   if (!has_exceptions())  return;
 987 
 988   if (failing()) {
 989     // Pop them all off and throw them away.
 990     while (pop_exception_state() != nullptr) ;
 991     return;
 992   }
 993 
 994   PreserveJVMState pjvms(this, false);
 995 
 996   SafePointNode* ex_map;
 997   while ((ex_map = pop_exception_state()) != nullptr) {
 998     if (!method()->has_exception_handlers()) {
 999       // Common case:  Transfer control outward.
1000       // Doing it this early allows the exceptions to common up
1001       // even between adjacent method calls.
1002       throw_to_exit(ex_map);
1003     } else {
1004       // Have to look at the exception first.
1005       assert(stopped(), "catch_inline_exceptions trashes the map");
1006       catch_inline_exceptions(ex_map);
1007       stop_and_kill_map();      // we used up this exception state; kill it
1008     }
1009   }
1010 
1011   // We now return to our regularly scheduled program:
1012 }
1013 
1014 //---------------------------throw_to_exit-------------------------------------
1015 // Merge the given map into an exception exit from this method.
1016 // The exception exit will handle any unlocking of receiver.
1017 // The ex_oop must be saved within the ex_map, unlike merge_exception.
1018 void Parse::throw_to_exit(SafePointNode* ex_map) {
1019   // Pop the JVMS to (a copy of) the caller.
1020   GraphKit caller;
1021   caller.set_map_clone(_caller->map());
1022   caller.set_bci(_caller->bci());
1023   caller.set_sp(_caller->sp());
1024   // Copy out the standard machine state:
1025   for (uint i = 0; i < TypeFunc::Parms; i++) {
1026     caller.map()->set_req(i, ex_map->in(i));
1027   }
1028   if (ex_map->has_replaced_nodes()) {
1029     _replaced_nodes_for_exceptions = true;
1030   }
1031   caller.map()->transfer_replaced_nodes_from(ex_map, _new_idx);
1032   // ...and the exception:
1033   Node*          ex_oop        = saved_ex_oop(ex_map);
1034   SafePointNode* caller_ex_map = caller.make_exception_state(ex_oop);
1035   // Finally, collect the new exception state in my exits:
1036   _exits.add_exception_state(caller_ex_map);
1037 }
1038 
1039 //------------------------------do_exits---------------------------------------
1040 void Parse::do_exits() {
1041   set_parse_bci(InvocationEntryBci);
1042 
1043   // Now peephole on the return bits
1044   Node* region = _exits.control();
1045   _exits.set_control(gvn().transform(region));
1046 
1047   Node* iophi = _exits.i_o();
1048   _exits.set_i_o(gvn().transform(iophi));
1049 
1050   // Figure out if we need to emit the trailing barrier. The barrier is only
1051   // needed in the constructors, and only in three cases:
1052   //
1053   // 1. The constructor wrote a final or a @Stable field. All these
1054   //    initializations must be ordered before any code after the constructor
1055   //    publishes the reference to the newly constructed object. Rather
1056   //    than wait for the publication, we simply block the writes here.
1057   //    Rather than put a barrier on only those writes which are required
1058   //    to complete, we force all writes to complete.
1059   //
1060   // 2. Experimental VM option is used to force the barrier if any field
1061   //    was written out in the constructor.
1062   //
1063   // 3. On processors which are not CPU_MULTI_COPY_ATOMIC (e.g. PPC64),
1064   //    support_IRIW_for_not_multiple_copy_atomic_cpu selects that
1065   //    MemBarVolatile is used before volatile load instead of after volatile
1066   //    store, so there's no barrier after the store.
1067   //    We want to guarantee the same behavior as on platforms with total store
1068   //    order, although this is not required by the Java memory model.
1069   //    In this case, we want to enforce visibility of volatile field
1070   //    initializations which are performed in constructors.
1071   //    So as with finals, we add a barrier here.
1072   //
1073   // "All bets are off" unless the first publication occurs after a
1074   // normal return from the constructor.  We do not attempt to detect
1075   // such unusual early publications.  But no barrier is needed on
1076   // exceptional returns, since they cannot publish normally.
1077   //
1078   if ((method()->is_object_constructor() || method()->is_class_initializer()) &&
1079        (wrote_final() || wrote_stable() ||
1080          (AlwaysSafeConstructors && wrote_fields()) ||
1081          (support_IRIW_for_not_multiple_copy_atomic_cpu && wrote_volatile()))) {
1082     Node* recorded_alloc = alloc_with_final_or_stable();
1083     _exits.insert_mem_bar(UseStoreStoreForCtor ? Op_MemBarStoreStore : Op_MemBarRelease,
1084                           recorded_alloc);
1085 
1086     // If Memory barrier is created for final fields write
1087     // and allocation node does not escape the initialize method,
1088     // then barrier introduced by allocation node can be removed.
1089     if (DoEscapeAnalysis && (recorded_alloc != nullptr)) {
1090       AllocateNode* alloc = AllocateNode::Ideal_allocation(recorded_alloc);
1091       alloc->compute_MemBar_redundancy(method());
1092     }
1093     if (PrintOpto && (Verbose || WizardMode)) {
1094       method()->print_name();
1095       tty->print_cr(" writes finals/@Stable and needs a memory barrier");
1096     }
1097   }
1098 
1099   for (MergeMemStream mms(_exits.merged_memory()); mms.next_non_empty(); ) {
1100     // transform each slice of the original memphi:
1101     mms.set_memory(_gvn.transform(mms.memory()));
1102   }
1103   // Clean up input MergeMems created by transforming the slices
1104   _gvn.transform(_exits.merged_memory());
1105 
1106   if (tf()->range_sig()->cnt() > TypeFunc::Parms) {
1107     const Type* ret_type = tf()->range_sig()->field_at(TypeFunc::Parms);
1108     Node*       ret_phi  = _gvn.transform( _exits.argument(0) );
1109     if (!_exits.control()->is_top() && _gvn.type(ret_phi)->empty()) {
1110       // If the type we set for the ret_phi in build_exits() is too optimistic and
1111       // the ret_phi is top now, there's an extremely small chance that it may be due to class
1112       // loading.  It could also be due to an error, so mark this method as not compilable because
1113       // otherwise this could lead to an infinite compile loop.
1114       // In any case, this code path is rarely (and never in my testing) reached.
1115       C->record_method_not_compilable("Can't determine return type.");
1116       return;
1117     }
1118     if (ret_type->isa_int()) {
1119       BasicType ret_bt = method()->return_type()->basic_type();
1120       ret_phi = mask_int_value(ret_phi, ret_bt, &_gvn);
1121     }
1122     _exits.push_node(ret_type->basic_type(), ret_phi);
1123   }
1124 
1125   // Note:  Logic for creating and optimizing the ReturnNode is in Compile.
1126 
1127   // Unlock along the exceptional paths.
1128   // This is done late so that we can common up equivalent exceptions
1129   // (e.g., null checks) arising from multiple points within this method.
1130   // See GraphKit::add_exception_state, which performs the commoning.
1131   bool do_synch = method()->is_synchronized();
1132 
1133   // record exit from a method if compiled while Dtrace is turned on.
1134   if (do_synch || C->env()->dtrace_method_probes() || _replaced_nodes_for_exceptions) {
1135     // First move the exception list out of _exits:
1136     GraphKit kit(_exits.transfer_exceptions_into_jvms());
1137     SafePointNode* normal_map = kit.map();  // keep this guy safe
1138     // Now re-collect the exceptions into _exits:
1139     SafePointNode* ex_map;
1140     while ((ex_map = kit.pop_exception_state()) != nullptr) {
1141       Node* ex_oop = kit.use_exception_state(ex_map);
1142       // Force the exiting JVM state to have this method at InvocationEntryBci.
1143       // The exiting JVM state is otherwise a copy of the calling JVMS.
1144       JVMState* caller = kit.jvms();
1145       JVMState* ex_jvms = caller->clone_shallow(C);
1146       ex_jvms->bind_map(kit.clone_map());
1147       ex_jvms->set_bci(   InvocationEntryBci);
1148       kit.set_jvms(ex_jvms);
1149       if (do_synch) {
1150         // Add on the synchronized-method box/object combo
1151         kit.map()->push_monitor(_synch_lock);
1152         // Unlock!
1153         kit.shared_unlock(_synch_lock->box_node(), _synch_lock->obj_node());
1154       }
1155       if (C->env()->dtrace_method_probes()) {
1156         kit.make_dtrace_method_exit(method());
1157       }
1158       if (_replaced_nodes_for_exceptions) {
1159         kit.map()->apply_replaced_nodes(_new_idx);
1160       }
1161       // Done with exception-path processing.
1162       ex_map = kit.make_exception_state(ex_oop);
1163       assert(ex_jvms->same_calls_as(ex_map->jvms()), "sanity");
1164       // Pop the last vestige of this method:
1165       caller->clone_shallow(C)->bind_map(ex_map);
1166       _exits.push_exception_state(ex_map);
1167     }
1168     assert(_exits.map() == normal_map, "keep the same return state");
1169   }
1170 
1171   {
1172     // Capture very early exceptions (receiver null checks) from caller JVMS
1173     GraphKit caller(_caller);
1174     SafePointNode* ex_map;
1175     while ((ex_map = caller.pop_exception_state()) != nullptr) {
1176       _exits.add_exception_state(ex_map);
1177     }
1178   }
1179   _exits.map()->apply_replaced_nodes(_new_idx);
1180 }
1181 
1182 //-----------------------------create_entry_map-------------------------------
1183 // Initialize our parser map to contain the types at method entry.
1184 // For OSR, the map contains a single RawPtr parameter.
1185 // Initial monitor locking for sync. methods is performed by do_method_entry.
1186 SafePointNode* Parse::create_entry_map() {
1187   // Check for really stupid bail-out cases.
1188   uint len = TypeFunc::Parms + method()->max_locals() + method()->max_stack();
1189   if (len >= 32760) {
1190     // Bailout expected, this is a very rare edge case.
1191     C->record_method_not_compilable("too many local variables");
1192     return nullptr;
1193   }
1194 
1195   // clear current replaced nodes that are of no use from here on (map was cloned in build_exits).
1196   _caller->map()->delete_replaced_nodes();
1197 
1198   // If this is an inlined method, we may have to do a receiver null check.
1199   if (_caller->has_method() && is_normal_parse() && !method()->is_static()) {
1200     GraphKit kit(_caller);
1201     Node* receiver = kit.argument(0);
1202     Node* null_free = kit.null_check_receiver_before_call(method());
1203     _caller = kit.transfer_exceptions_into_jvms();
1204 
1205     if (kit.stopped()) {
1206       _exits.add_exception_states_from(_caller);
1207       _exits.set_jvms(_caller);
1208       return nullptr;
1209     }
1210   }
1211 
1212   assert(method() != nullptr, "parser must have a method");
1213 
1214   // Create an initial safepoint to hold JVM state during parsing
1215   JVMState* jvms = new (C) JVMState(method(), _caller->has_method() ? _caller : nullptr);
1216   set_map(new SafePointNode(len, jvms));
1217 
1218   // Capture receiver info for compiled lambda forms.
1219   if (method()->is_compiled_lambda_form()) {
1220     ciInstance* recv_info = _caller->compute_receiver_info(method());
1221     jvms->set_receiver_info(recv_info);
1222   }
1223 
1224   jvms->set_map(map());
1225   record_for_igvn(map());
1226   assert(jvms->endoff() == len, "correct jvms sizing");
1227 
1228   SafePointNode* inmap = _caller->map();
1229   assert(inmap != nullptr, "must have inmap");
1230   // In case of null check on receiver above
1231   map()->transfer_replaced_nodes_from(inmap, _new_idx);
1232 
1233   uint i;
1234 
1235   // Pass thru the predefined input parameters.
1236   for (i = 0; i < TypeFunc::Parms; i++) {
1237     map()->init_req(i, inmap->in(i));
1238   }
1239 
1240   if (depth() == 1) {
1241     assert(map()->memory()->Opcode() == Op_Parm, "");
1242     // Insert the memory aliasing node
1243     set_all_memory(reset_memory());
1244   }
1245   assert(merged_memory(), "");
1246 
1247   // Now add the locals which are initially bound to arguments:
1248   uint arg_size = tf()->domain_sig()->cnt();
1249   ensure_stack(arg_size - TypeFunc::Parms);  // OSR methods have funny args
1250   for (i = TypeFunc::Parms; i < arg_size; i++) {
1251     map()->init_req(i, inmap->argument(_caller, i - TypeFunc::Parms));
1252   }
1253 
1254   // Clear out the rest of the map (locals and stack)
1255   for (i = arg_size; i < len; i++) {
1256     map()->init_req(i, top());
1257   }
1258 
1259   SafePointNode* entry_map = stop();
1260   return entry_map;
1261 }
1262 
1263 //-----------------------------do_method_entry--------------------------------
1264 // Emit any code needed in the pseudo-block before BCI zero.
1265 // The main thing to do is lock the receiver of a synchronized method.
1266 void Parse::do_method_entry() {
1267   set_parse_bci(InvocationEntryBci); // Pseudo-BCP
1268   set_sp(0);                         // Java Stack Pointer
1269 
1270   NOT_PRODUCT( count_compiled_calls(true/*at_method_entry*/, false/*is_inline*/); )
1271 
1272   // Check if we need a membar at the beginning of the java.lang.Object
1273   // constructor to satisfy the memory model for strict fields.
1274   if (Arguments::is_valhalla_enabled() && method()->intrinsic_id() == vmIntrinsics::_Object_init) {
1275     Node* receiver_obj = local(0);
1276     const TypeInstPtr* receiver_type = _gvn.type(receiver_obj)->isa_instptr();
1277     // If there's no exact type, check if the declared type has no implementors and add a dependency
1278     const TypeKlassPtr* klass_ptr = receiver_type->as_klass_type(/* try_for_exact= */ true);
1279     ciType* klass = klass_ptr->klass_is_exact() ? klass_ptr->exact_klass() : nullptr;
1280     if (klass != nullptr && klass->is_instance_klass()) {
1281       // Exact receiver type, check if there is a strict field
1282       ciInstanceKlass* holder = klass->as_instance_klass();
1283       for (int i = 0; i < holder->nof_nonstatic_fields(); i++) {
1284         ciField* field = holder->nonstatic_field_at(i);
1285         if (field->is_strict()) {
1286           // Found a strict field, a membar is needed
1287           AllocateNode* alloc = AllocateNode::Ideal_allocation(receiver_obj);
1288           insert_mem_bar(UseStoreStoreForCtor ? Op_MemBarStoreStore : Op_MemBarRelease, receiver_obj);
1289           if (DoEscapeAnalysis && (alloc != nullptr)) {
1290             alloc->compute_MemBar_redundancy(method());
1291           }
1292           break;
1293         }
1294       }
1295     } else if (klass == nullptr) {
1296       // We can't statically determine the type of the receiver and therefore need
1297       // to put a membar here because it could have a strict field.
1298       insert_mem_bar(UseStoreStoreForCtor ? Op_MemBarStoreStore : Op_MemBarRelease);
1299     }
1300   }
1301 
1302   if (C->env()->dtrace_method_probes()) {
1303     make_dtrace_method_entry(method());
1304   }
1305 
1306 #ifdef ASSERT
1307   // Narrow receiver type when it is too broad for the method being parsed.
1308   if (!method()->is_static()) {
1309     ciInstanceKlass* callee_holder = method()->holder();
1310     const Type* holder_type = TypeInstPtr::make(TypePtr::BotPTR, callee_holder, Type::trust_interfaces);
1311 
1312     Node* receiver_obj = local(0);
1313     const TypeInstPtr* receiver_type = _gvn.type(receiver_obj)->isa_instptr();
1314 
1315     if (receiver_type != nullptr && !receiver_type->higher_equal(holder_type)) {
1316       // Receiver should always be a subtype of callee holder.
1317       // But, since C2 type system doesn't properly track interfaces,
1318       // the invariant can't be expressed in the type system for default methods.
1319       // Example: for unrelated C <: I and D <: I, (C `meet` D) = Object </: I.
1320       assert(callee_holder->is_interface(), "missing subtype check");
1321 
1322       // Perform dynamic receiver subtype check against callee holder class w/ a halt on failure.
1323       Node* holder_klass = _gvn.makecon(TypeKlassPtr::make(callee_holder, Type::trust_interfaces));
1324       Node* not_subtype_ctrl = gen_subtype_check(receiver_obj, holder_klass);
1325       assert(!stopped(), "not a subtype");
1326 
1327       halt(not_subtype_ctrl, frameptr(), "failed receiver subtype check");
1328     }
1329   }
1330 #endif // ASSERT
1331 
1332   // If the method is synchronized, we need to construct a lock node, attach
1333   // it to the Start node, and pin it there.
1334   if (method()->is_synchronized()) {
1335     // Insert a FastLockNode right after the Start which takes as arguments
1336     // the current thread pointer, the "this" pointer & the address of the
1337     // stack slot pair used for the lock.  The "this" pointer is a projection
1338     // off the start node, but the locking spot has to be constructed by
1339     // creating a ConLNode of 0, and boxing it with a BoxLockNode.  The BoxLockNode
1340     // becomes the second argument to the FastLockNode call.  The
1341     // FastLockNode becomes the new control parent to pin it to the start.
1342 
1343     // Setup Object Pointer
1344     Node *lock_obj = nullptr;
1345     if (method()->is_static()) {
1346       ciInstance* mirror = _method->holder()->java_mirror();
1347       const TypeInstPtr *t_lock = TypeInstPtr::make(mirror);
1348       lock_obj = makecon(t_lock);
1349     } else {                  // Else pass the "this" pointer,
1350       lock_obj = local(0);    // which is Parm0 from StartNode
1351       assert(!_gvn.type(lock_obj)->make_oopptr()->can_be_inline_type(), "can't be an inline type");
1352     }
1353     // Clear out dead values from the debug info.
1354     kill_dead_locals();
1355     // Build the FastLockNode
1356     _synch_lock = shared_lock(lock_obj);
1357     // Check for bailout in shared_lock
1358     if (failing()) { return; }
1359   }
1360 
1361   // Feed profiling data for parameters to the type system so it can
1362   // propagate it as speculative types
1363   record_profiled_parameters_for_speculation();
1364 
1365   // More argument handling
1366   int arg_size = method()->arg_size();
1367   for (int i = 0; i < arg_size; i++) {
1368     Node* parm = local(i);
1369     const Type* t = _gvn.type(parm);
1370     if (t->is_inlinetypeptr()) {
1371       // If the parameter is a value object, try to scalarize it if we know that it is unrestricted (not early larval)
1372       // Parameters are non-larval except the receiver of a constructor, which must be an early larval object.
1373       if (!(method()->is_object_constructor() && i == 0)) {
1374         // Create InlineTypeNode from the oop and replace the parameter
1375         Node* vt = InlineTypeNode::make_from_oop(this, parm, t->inline_klass());
1376         replace_in_map(parm, vt);
1377       }
1378     } else if (UseTypeSpeculation && (i == (arg_size - 1)) && depth() == 1 && method()->has_vararg() && t->isa_aryptr()) {
1379       // Speculate on varargs Object array being the default array refined type. The assumption is
1380       // that a vararg method test(Object... o) is often called as test(o1, o2, o3). javac will
1381       // translate the call so that the caller will create a new default array of Object, put o1,
1382       // o2, o3 into the newly created array, then invoke the method test. This only makes sense if
1383       // the method we are parsing is the top-level method of the compilation unit. Otherwise, if
1384       // it is truly called according to our assumption, we must know the exact type of the
1385       // argument because the allocation happens inside the compilation unit.
1386       const TypePtr* spec_type = (t->speculative() != nullptr) ? t->speculative() : t->remove_speculative()->is_aryptr();
1387       ciSignature* method_signature = method()->signature();
1388       ciType* parm_citype = method_signature->type_at(method_signature->count() - 1);
1389       if (!parm_citype->is_obj_array_klass()) {
1390         continue;
1391       }
1392 
1393       ciObjArrayKlass* spec_citype = ciObjArrayKlass::make(parm_citype->as_obj_array_klass()->element_klass(), true);
1394       const Type* improved_spec_type = TypeKlassPtr::make(spec_citype, Type::trust_interfaces)->as_instance_type();
1395       improved_spec_type = improved_spec_type->join(spec_type)->join(TypePtr::NOTNULL);
1396       if (improved_spec_type->empty()) {
1397         continue;
1398       }
1399 
1400       const TypePtr* improved_type = TypeOopPtr::make(TypePtr::BotPTR, Type::Offset::bottom, TypeOopPtr::InstanceBot, improved_spec_type->is_ptr());
1401       improved_type = improved_type->join_speculative(t)->is_ptr();
1402       if (improved_type != t) {
1403         Node* cast = _gvn.transform(new CheckCastPPNode(control(), parm, improved_type, ConstraintCastNode::DependencyType::NonFloatingNarrowing));
1404         replace_in_map(parm, cast);
1405       }
1406     }
1407   }
1408 }
1409 
1410 //------------------------------init_blocks------------------------------------
1411 // Initialize our parser map to contain the types/monitors at method entry.
1412 void Parse::init_blocks() {
1413   // Create the blocks.
1414   _block_count = flow()->block_count();
1415   _blocks = NEW_RESOURCE_ARRAY(Block, _block_count);
1416 
1417   // Initialize the structs.
1418   for (int rpo = 0; rpo < block_count(); rpo++) {
1419     Block* block = rpo_at(rpo);
1420     new(block) Block(this, rpo);
1421   }
1422 
1423   // Collect predecessor and successor information.
1424   for (int rpo = 0; rpo < block_count(); rpo++) {
1425     Block* block = rpo_at(rpo);
1426     block->init_graph(this);
1427   }
1428 }
1429 
1430 //-------------------------------init_node-------------------------------------
1431 Parse::Block::Block(Parse* outer, int rpo) : _live_locals() {
1432   _flow = outer->flow()->rpo_at(rpo);
1433   _pred_count = 0;
1434   _preds_parsed = 0;
1435   _count = 0;
1436   _is_parsed = false;
1437   _is_handler = false;
1438   _has_merged_backedge = false;
1439   _start_map = nullptr;
1440   _has_predicates = false;
1441   _num_successors = 0;
1442   _all_successors = 0;
1443   _successors = nullptr;
1444   assert(pred_count() == 0 && preds_parsed() == 0, "sanity");
1445   assert(!(is_merged() || is_parsed() || is_handler() || has_merged_backedge()), "sanity");
1446   assert(_live_locals.size() == 0, "sanity");
1447 
1448   // entry point has additional predecessor
1449   if (flow()->is_start())  _pred_count++;
1450   assert(flow()->is_start() == (this == outer->start_block()), "");
1451 }
1452 
1453 //-------------------------------init_graph------------------------------------
1454 void Parse::Block::init_graph(Parse* outer) {
1455   // Create the successor list for this parser block.
1456   GrowableArray<ciTypeFlow::Block*>* tfs = flow()->successors();
1457   GrowableArray<ciTypeFlow::Block*>* tfe = flow()->exceptions();
1458   int ns = tfs->length();
1459   int ne = tfe->length();
1460   _num_successors = ns;
1461   _all_successors = ns+ne;
1462   _successors = (ns+ne == 0) ? nullptr : NEW_RESOURCE_ARRAY(Block*, ns+ne);
1463   int p = 0;
1464   for (int i = 0; i < ns+ne; i++) {
1465     ciTypeFlow::Block* tf2 = (i < ns) ? tfs->at(i) : tfe->at(i-ns);
1466     Block* block2 = outer->rpo_at(tf2->rpo());
1467     _successors[i] = block2;
1468 
1469     // Accumulate pred info for the other block, too.
1470     // Note: We also need to set _pred_count for exception blocks since they could
1471     // also have normal predecessors (reached without athrow by an explicit jump).
1472     // This also means that next_path_num can be called along exception paths.
1473     block2->_pred_count++;
1474     if (i >= ns) {
1475       block2->_is_handler = true;
1476     }
1477 
1478     #ifdef ASSERT
1479     // A block's successors must be distinguishable by BCI.
1480     // That is, no bytecode is allowed to branch to two different
1481     // clones of the same code location.
1482     for (int j = 0; j < i; j++) {
1483       Block* block1 = _successors[j];
1484       if (block1 == block2)  continue;  // duplicates are OK
1485       assert(block1->start() != block2->start(), "successors have unique bcis");
1486     }
1487     #endif
1488   }
1489 }
1490 
1491 //---------------------------successor_for_bci---------------------------------
1492 Parse::Block* Parse::Block::successor_for_bci(int bci) {
1493   for (int i = 0; i < all_successors(); i++) {
1494     Block* block2 = successor_at(i);
1495     if (block2->start() == bci)  return block2;
1496   }
1497   // We can actually reach here if ciTypeFlow traps out a block
1498   // due to an unloaded class, and concurrently with compilation the
1499   // class is then loaded, so that a later phase of the parser is
1500   // able to see more of the bytecode CFG.  Or, the flow pass and
1501   // the parser can have a minor difference of opinion about executability
1502   // of bytecodes.  For example, "obj.field = null" is executable even
1503   // if the field's type is an unloaded class; the flow pass used to
1504   // make a trap for such code.
1505   return nullptr;
1506 }
1507 
1508 
1509 //-----------------------------stack_type_at-----------------------------------
1510 const Type* Parse::Block::stack_type_at(int i) const {
1511   return get_type(flow()->stack_type_at(i));
1512 }
1513 
1514 
1515 //-----------------------------local_type_at-----------------------------------
1516 const Type* Parse::Block::local_type_at(int i) const {
1517   // Make dead locals fall to bottom.
1518   if (_live_locals.size() == 0) {
1519     MethodLivenessResult live_locals = flow()->outer()->method()->liveness_at_bci(start());
1520     // This bitmap can be zero length if we saw a breakpoint.
1521     // In such cases, pretend they are all live.
1522     ((Block*)this)->_live_locals = live_locals;
1523   }
1524   if (_live_locals.size() > 0 && !_live_locals.at(i))
1525     return Type::BOTTOM;
1526 
1527   return get_type(flow()->local_type_at(i));
1528 }
1529 
1530 
1531 #ifndef PRODUCT
1532 
1533 //----------------------------name_for_bc--------------------------------------
1534 // helper method for BytecodeParseHistogram
1535 static const char* name_for_bc(int i) {
1536   return Bytecodes::is_defined(i) ? Bytecodes::name(Bytecodes::cast(i)) : "xxxunusedxxx";
1537 }
1538 
1539 //----------------------------BytecodeParseHistogram------------------------------------
1540 Parse::BytecodeParseHistogram::BytecodeParseHistogram(Parse *p, Compile *c) {
1541   _parser   = p;
1542   _compiler = c;
1543   if( ! _initialized ) { _initialized = true; reset(); }
1544 }
1545 
1546 //----------------------------current_count------------------------------------
1547 int Parse::BytecodeParseHistogram::current_count(BPHType bph_type) {
1548   switch( bph_type ) {
1549   case BPH_transforms: { return _parser->gvn().made_progress(); }
1550   case BPH_values:     { return _parser->gvn().made_new_values(); }
1551   default: { ShouldNotReachHere(); return 0; }
1552   }
1553 }
1554 
1555 //----------------------------initialized--------------------------------------
1556 bool Parse::BytecodeParseHistogram::initialized() { return _initialized; }
1557 
1558 //----------------------------reset--------------------------------------------
1559 void Parse::BytecodeParseHistogram::reset() {
1560   int i = Bytecodes::number_of_codes;
1561   while (i-- > 0) { _bytecodes_parsed[i] = 0; _nodes_constructed[i] = 0; _nodes_transformed[i] = 0; _new_values[i] = 0; }
1562 }
1563 
1564 //----------------------------set_initial_state--------------------------------
1565 // Record info when starting to parse one bytecode
1566 void Parse::BytecodeParseHistogram::set_initial_state( Bytecodes::Code bc ) {
1567   if( PrintParseStatistics && !_parser->is_osr_parse() ) {
1568     _initial_bytecode    = bc;
1569     _initial_node_count  = _compiler->unique();
1570     _initial_transforms  = current_count(BPH_transforms);
1571     _initial_values      = current_count(BPH_values);
1572   }
1573 }
1574 
1575 //----------------------------record_change--------------------------------
1576 // Record results of parsing one bytecode
1577 void Parse::BytecodeParseHistogram::record_change() {
1578   if( PrintParseStatistics && !_parser->is_osr_parse() ) {
1579     ++_bytecodes_parsed[_initial_bytecode];
1580     _nodes_constructed [_initial_bytecode] += (_compiler->unique() - _initial_node_count);
1581     _nodes_transformed [_initial_bytecode] += (current_count(BPH_transforms) - _initial_transforms);
1582     _new_values        [_initial_bytecode] += (current_count(BPH_values)     - _initial_values);
1583   }
1584 }
1585 
1586 
1587 //----------------------------print--------------------------------------------
1588 void Parse::BytecodeParseHistogram::print(float cutoff) {
1589   ResourceMark rm;
1590   // print profile
1591   int total  = 0;
1592   int i      = 0;
1593   for( i = 0; i < Bytecodes::number_of_codes; ++i ) { total += _bytecodes_parsed[i]; }
1594   int abs_sum = 0;
1595   tty->cr();   //0123456789012345678901234567890123456789012345678901234567890123456789
1596   tty->print_cr("Histogram of %d parsed bytecodes:", total);
1597   if( total == 0 ) { return; }
1598   tty->cr();
1599   tty->print_cr("absolute:  count of compiled bytecodes of this type");
1600   tty->print_cr("relative:  percentage contribution to compiled nodes");
1601   tty->print_cr("nodes   :  Average number of nodes constructed per bytecode");
1602   tty->print_cr("rnodes  :  Significance towards total nodes constructed, (nodes*relative)");
1603   tty->print_cr("transforms: Average amount of transform progress per bytecode compiled");
1604   tty->print_cr("values  :  Average number of node values improved per bytecode");
1605   tty->print_cr("name    :  Bytecode name");
1606   tty->cr();
1607   tty->print_cr("  absolute  relative   nodes  rnodes  transforms  values   name");
1608   tty->print_cr("----------------------------------------------------------------------");
1609   while (--i > 0) {
1610     int       abs = _bytecodes_parsed[i];
1611     float     rel = abs * 100.0F / total;
1612     float   nodes = _bytecodes_parsed[i] == 0 ? 0 : (1.0F * _nodes_constructed[i])/_bytecodes_parsed[i];
1613     float  rnodes = _bytecodes_parsed[i] == 0 ? 0 :  rel * nodes;
1614     float  xforms = _bytecodes_parsed[i] == 0 ? 0 : (1.0F * _nodes_transformed[i])/_bytecodes_parsed[i];
1615     float  values = _bytecodes_parsed[i] == 0 ? 0 : (1.0F * _new_values       [i])/_bytecodes_parsed[i];
1616     if (cutoff <= rel) {
1617       tty->print_cr("%10d  %7.2f%%  %6.1f  %6.2f   %6.1f   %6.1f     %s", abs, rel, nodes, rnodes, xforms, values, name_for_bc(i));
1618       abs_sum += abs;
1619     }
1620   }
1621   tty->print_cr("----------------------------------------------------------------------");
1622   float rel_sum = abs_sum * 100.0F / total;
1623   tty->print_cr("%10d  %7.2f%%    (cutoff = %.2f%%)", abs_sum, rel_sum, cutoff);
1624   tty->print_cr("----------------------------------------------------------------------");
1625   tty->cr();
1626 }
1627 #endif
1628 
1629 //----------------------------load_state_from----------------------------------
1630 // Load block/map/sp.  But not do not touch iter/bci.
1631 void Parse::load_state_from(Block* block) {
1632   set_block(block);
1633   // load the block's JVM state:
1634   set_map(block->start_map());
1635   set_sp( block->start_sp());
1636 }
1637 
1638 
1639 //-----------------------------record_state------------------------------------
1640 void Parse::Block::record_state(Parse* p) {
1641   assert(!is_merged(), "can only record state once, on 1st inflow");
1642   assert(start_sp() == p->sp(), "stack pointer must agree with ciTypeFlow");
1643   set_start_map(p->stop());
1644 }
1645 
1646 
1647 //------------------------------do_one_block-----------------------------------
1648 void Parse::do_one_block() {
1649   if (TraceOptoParse) {
1650     Block *b = block();
1651     int ns = b->num_successors();
1652     int nt = b->all_successors();
1653 
1654     tty->print("Parsing block #%d at bci [%d,%d), successors:",
1655                   block()->rpo(), block()->start(), block()->limit());
1656     for (int i = 0; i < nt; i++) {
1657       tty->print((( i < ns) ? " %d" : " %d(exception block)"), b->successor_at(i)->rpo());
1658     }
1659     if (b->is_loop_head()) {
1660       tty->print("  loop head");
1661     }
1662     if (b->is_irreducible_loop_entry()) {
1663       tty->print("  irreducible");
1664     }
1665     tty->cr();
1666   }
1667 
1668   assert(block()->is_merged(), "must be merged before being parsed");
1669   block()->mark_parsed();
1670 
1671   // Set iterator to start of block.
1672   iter().reset_to_bci(block()->start());
1673 
1674   if (ProfileExceptionHandlers && block()->is_handler()) {
1675     ciMethodData* methodData = method()->method_data();
1676     if (methodData->is_mature()) {
1677       ciBitData data = methodData->exception_handler_bci_to_data(block()->start());
1678       if (!data.exception_handler_entered() || StressPrunedExceptionHandlers) {
1679         // dead catch block
1680         // Emit an uncommon trap instead of processing the block.
1681         set_parse_bci(block()->start());
1682         uncommon_trap(Deoptimization::Reason_unreached,
1683                       Deoptimization::Action_reinterpret,
1684                       nullptr, "dead catch block");
1685         return;
1686       }
1687     }
1688   }
1689 
1690   CompileLog* log = C->log();
1691 
1692   // Parse bytecodes
1693   while (!stopped() && !failing()) {
1694     iter().next();
1695 
1696     // Learn the current bci from the iterator:
1697     set_parse_bci(iter().cur_bci());
1698 
1699     if (bci() == block()->limit()) {
1700       // Do not walk into the next block until directed by do_all_blocks.
1701       merge(bci());
1702       break;
1703     }
1704     assert(bci() < block()->limit(), "bci still in block");
1705 
1706     if (log != nullptr) {
1707       // Output an optional context marker, to help place actions
1708       // that occur during parsing of this BC.  If there is no log
1709       // output until the next context string, this context string
1710       // will be silently ignored.
1711       log->set_context("bc code='%d' bci='%d'", (int)bc(), bci());
1712     }
1713 
1714     if (block()->has_trap_at(bci())) {
1715       // We must respect the flow pass's traps, because it will refuse
1716       // to produce successors for trapping blocks.
1717       int trap_index = block()->flow()->trap_index();
1718       assert(trap_index != 0, "trap index must be valid");
1719       uncommon_trap(trap_index);
1720       break;
1721     }
1722 
1723     NOT_PRODUCT( parse_histogram()->set_initial_state(bc()); );
1724 
1725 #ifdef ASSERT
1726     int pre_bc_sp = sp();
1727     int inputs, depth;
1728     bool have_se = !stopped() && compute_stack_effects(inputs, depth);
1729     assert(!have_se || pre_bc_sp >= inputs, "have enough stack to execute this BC: pre_bc_sp=%d, inputs=%d", pre_bc_sp, inputs);
1730 #endif //ASSERT
1731 
1732     do_one_bytecode();
1733     if (failing()) return;
1734 
1735     assert(!have_se || stopped() || failing() || (sp() - pre_bc_sp) == depth,
1736            "incorrect depth prediction: sp=%d, pre_bc_sp=%d, depth=%d", sp(), pre_bc_sp, depth);
1737 
1738     do_exceptions();
1739 
1740     NOT_PRODUCT( parse_histogram()->record_change(); );
1741 
1742     if (log != nullptr)
1743       log->clear_context();  // skip marker if nothing was printed
1744 
1745     // Fall into next bytecode.  Each bytecode normally has 1 sequential
1746     // successor which is typically made ready by visiting this bytecode.
1747     // If the successor has several predecessors, then it is a merge
1748     // point, starts a new basic block, and is handled like other basic blocks.
1749   }
1750 }
1751 
1752 
1753 //------------------------------merge------------------------------------------
1754 void Parse::set_parse_bci(int bci) {
1755   set_bci(bci);
1756   Node_Notes* nn = C->default_node_notes();
1757   if (nn == nullptr)  return;
1758 
1759   // Collect debug info for inlined calls unless -XX:-DebugInlinedCalls.
1760   if (!DebugInlinedCalls && depth() > 1) {
1761     return;
1762   }
1763 
1764   // Update the JVMS annotation, if present.
1765   JVMState* jvms = nn->jvms();
1766   if (jvms != nullptr && jvms->bci() != bci) {
1767     // Update the JVMS.
1768     jvms = jvms->clone_shallow(C);
1769     jvms->set_bci(bci);
1770     nn->set_jvms(jvms);
1771   }
1772 }
1773 
1774 //------------------------------merge------------------------------------------
1775 // Merge the current mapping into the basic block starting at bci
1776 void Parse::merge(int target_bci) {
1777   Block* target = successor_for_bci(target_bci);
1778   if (target == nullptr) { handle_missing_successor(target_bci); return; }
1779   assert(!target->is_ready(), "our arrival must be expected");
1780   int pnum = target->next_path_num();
1781   merge_common(target, pnum);
1782 }
1783 
1784 //-------------------------merge_new_path--------------------------------------
1785 // Merge the current mapping into the basic block, using a new path
1786 void Parse::merge_new_path(int target_bci) {
1787   Block* target = successor_for_bci(target_bci);
1788   if (target == nullptr) { handle_missing_successor(target_bci); return; }
1789   assert(!target->is_ready(), "new path into frozen graph");
1790   int pnum = target->add_new_path();
1791   merge_common(target, pnum);
1792 }
1793 
1794 //-------------------------merge_exception-------------------------------------
1795 // Merge the current mapping into the basic block starting at bci
1796 // The ex_oop must be pushed on the stack, unlike throw_to_exit.
1797 void Parse::merge_exception(int target_bci) {
1798 #ifdef ASSERT
1799   if (target_bci <= bci()) {
1800     C->set_exception_backedge();
1801   }
1802 #endif
1803   assert(sp() == 1, "must have only the throw exception on the stack");
1804   Block* target = successor_for_bci(target_bci);
1805   if (target == nullptr) { handle_missing_successor(target_bci); return; }
1806   assert(target->is_handler(), "exceptions are handled by special blocks");
1807   int pnum = target->add_new_path();
1808   merge_common(target, pnum);
1809 }
1810 
1811 //--------------------handle_missing_successor---------------------------------
1812 void Parse::handle_missing_successor(int target_bci) {
1813 #ifndef PRODUCT
1814   Block* b = block();
1815   int trap_bci = b->flow()->has_trap()? b->flow()->trap_bci(): -1;
1816   tty->print_cr("### Missing successor at bci:%d for block #%d (trap_bci:%d)", target_bci, b->rpo(), trap_bci);
1817 #endif
1818   ShouldNotReachHere();
1819 }
1820 
1821 //--------------------------merge_common---------------------------------------
1822 void Parse::merge_common(Parse::Block* target, int pnum) {
1823   if (TraceOptoParse) {
1824     tty->print("Merging state at block #%d bci:%d", target->rpo(), target->start());
1825   }
1826 
1827   // Zap extra stack slots to top
1828   assert(sp() == target->start_sp(), "");
1829   clean_stack(sp());
1830 
1831   // Check for merge conflicts involving inline types
1832   JVMState* old_jvms = map()->jvms();
1833   int old_bci = bci();
1834   JVMState* tmp_jvms = old_jvms->clone_shallow(C);
1835   tmp_jvms->set_should_reexecute(true);
1836   tmp_jvms->bind_map(map());
1837   // Execution needs to restart a the next bytecode (entry of next
1838   // block)
1839   if (target->is_merged() ||
1840       pnum > PhiNode::Input ||
1841       target->is_handler() ||
1842       target->is_loop_head()) {
1843     set_parse_bci(target->start());
1844     for (uint j = TypeFunc::Parms; j < map()->req(); j++) {
1845       Node* n = map()->in(j);                 // Incoming change to target state.
1846       const Type* t = nullptr;
1847       ciType* ct = nullptr;
1848       if (tmp_jvms->is_loc(j)) {
1849         int loc_idx = j - tmp_jvms->locoff();
1850         t = target->local_type_at(loc_idx);
1851         ct = target->flow()->local_type_at(loc_idx);
1852       } else if (tmp_jvms->is_stk(j) && j < (uint)sp() + tmp_jvms->stkoff()) {
1853         int stk_idx = j - tmp_jvms->stkoff();
1854         t = target->stack_type_at(stk_idx);
1855         ct = target->flow()->stack_type_at(stk_idx);
1856       }
1857       if (t != nullptr && t != Type::BOTTOM) {
1858         // An object can appear in the JVMS as either an oop or an InlineTypeNode. If the merge is
1859         // an InlineTypeNode, we need all the merge inputs to be InlineTypeNodes. Else, if the
1860         // merge is an oop, each merge input needs to be either an oop or an buffered
1861         // InlineTypeNode.
1862         if (!t->is_inlinetypeptr()) {
1863           // The merge cannot be an InlineTypeNode, ensure the input is buffered if it is an
1864           // InlineTypeNode
1865           if (n->is_InlineType()) {
1866             map()->set_req(j, n->as_InlineType()->buffer(this));
1867           }
1868         } else {
1869           // Scalarize the value object if it is not larval
1870           if (!n->is_InlineType() && !ct->is_early_larval()) {
1871             assert(_gvn.type(n) == TypePtr::NULL_PTR, "must be a null constant");
1872             map()->set_req(j, InlineTypeNode::make_null(_gvn, t->inline_klass()));
1873           }
1874         }
1875       }
1876     }
1877   }
1878   old_jvms->bind_map(map());
1879   set_parse_bci(old_bci);
1880 
1881   if (!target->is_merged()) {   // No prior mapping at this bci
1882     if (TraceOptoParse) { tty->print(" with empty state");  }
1883 
1884     // If this path is dead, do not bother capturing it as a merge.
1885     // It is "as if" we had 1 fewer predecessors from the beginning.
1886     if (stopped()) {
1887       if (TraceOptoParse)  tty->print_cr(", but path is dead and doesn't count");
1888       return;
1889     }
1890 
1891     // Make a region if we know there are multiple or unpredictable inputs.
1892     // (Also, if this is a plain fall-through, we might see another region,
1893     // which must not be allowed into this block's map.)
1894     if (pnum > PhiNode::Input         // Known multiple inputs.
1895         || target->is_handler()       // These have unpredictable inputs.
1896         || target->is_loop_head()     // Known multiple inputs
1897         || control()->is_Region()) {  // We must hide this guy.
1898 
1899       int current_bci = bci();
1900       set_parse_bci(target->start()); // Set target bci
1901       if (target->is_SEL_head()) {
1902         DEBUG_ONLY( target->mark_merged_backedge(block()); )
1903         if (target->start() == 0) {
1904           // Add Parse Predicates for the special case when
1905           // there are backbranches to the method entry.
1906           add_parse_predicates();
1907         }
1908       }
1909       // Add a Region to start the new basic block.  Phis will be added
1910       // later lazily.
1911       int edges = target->pred_count();
1912       if (edges < pnum)  edges = pnum;  // might be a new path!
1913       RegionNode *r = new RegionNode(edges+1);
1914       gvn().set_type(r, Type::CONTROL);
1915       record_for_igvn(r);
1916       // zap all inputs to null for debugging (done in Node(uint) constructor)
1917       // for (int j = 1; j < edges+1; j++) { r->init_req(j, nullptr); }
1918       r->init_req(pnum, control());
1919       set_control(r);
1920       target->copy_irreducible_status_to(r, jvms());
1921       set_parse_bci(current_bci); // Restore bci
1922     }
1923 
1924     // Convert the existing Parser mapping into a mapping at this bci.
1925     store_state_to(target);
1926     assert(target->is_merged(), "do not come here twice");
1927 
1928   } else {                      // Prior mapping at this bci
1929     if (TraceOptoParse) {  tty->print(" with previous state"); }
1930 #ifdef ASSERT
1931     if (target->is_SEL_head()) {
1932       target->mark_merged_backedge(block());
1933     }
1934 #endif
1935 
1936     // We must not manufacture more phis if the target is already parsed.
1937     bool nophi = target->is_parsed();
1938 
1939     SafePointNode* newin = map();// Hang on to incoming mapping
1940     Block* save_block = block(); // Hang on to incoming block;
1941     load_state_from(target);    // Get prior mapping
1942 
1943     assert(newin->jvms()->locoff() == jvms()->locoff(), "JVMS layouts agree");
1944     assert(newin->jvms()->stkoff() == jvms()->stkoff(), "JVMS layouts agree");
1945     assert(newin->jvms()->monoff() == jvms()->monoff(), "JVMS layouts agree");
1946     assert(newin->jvms()->endoff() == jvms()->endoff(), "JVMS layouts agree");
1947 
1948     // Iterate over my current mapping and the old mapping.
1949     // Where different, insert Phi functions.
1950     // Use any existing Phi functions.
1951     assert(control()->is_Region(), "must be merging to a region");
1952     RegionNode* r = control()->as_Region();
1953 
1954     // Compute where to merge into
1955     // Merge incoming control path
1956     r->init_req(pnum, newin->control());
1957 
1958     if (pnum == 1) {            // Last merge for this Region?
1959       if (!block()->flow()->is_irreducible_loop_secondary_entry()) {
1960         Node* result = _gvn.transform(r);
1961         if (r != result && TraceOptoParse) {
1962           tty->print_cr("Block #%d replace %d with %d", block()->rpo(), r->_idx, result->_idx);
1963         }
1964       }
1965       record_for_igvn(r);
1966     }
1967 
1968     // Update all the non-control inputs to map:
1969     assert(TypeFunc::Parms == newin->jvms()->locoff(), "parser map should contain only youngest jvms");
1970     bool check_elide_phi = target->is_SEL_backedge(save_block);
1971     bool last_merge = (pnum == PhiNode::Input);
1972     for (uint j = 1; j < newin->req(); j++) {
1973       Node* m = map()->in(j);   // Current state of target.
1974       Node* n = newin->in(j);   // Incoming change to target state.
1975       Node* phi;
1976       if (m->is_Phi() && m->as_Phi()->region() == r) {
1977         phi = m;
1978       } else if (m->is_InlineType() && m->as_InlineType()->has_phi_inputs(r)) {
1979         phi = m;
1980       } else {
1981         phi = nullptr;
1982       }
1983       if (m != n) {             // Different; must merge
1984         switch (j) {
1985         // Frame pointer and Return Address never changes
1986         case TypeFunc::FramePtr:// Drop m, use the original value
1987         case TypeFunc::ReturnAdr:
1988           break;
1989         case TypeFunc::Memory:  // Merge inputs to the MergeMem node
1990           assert(phi == nullptr, "the merge contains phis, not vice versa");
1991           merge_memory_edges(n->as_MergeMem(), pnum, nophi);
1992           continue;
1993         default:                // All normal stuff
1994           if (phi == nullptr) {
1995             const JVMState* jvms = map()->jvms();
1996             if (EliminateNestedLocks &&
1997                 jvms->is_mon(j) && jvms->is_monitor_box(j)) {
1998               // BoxLock nodes are not commoning when EliminateNestedLocks is on.
1999               // Use old BoxLock node as merged box.
2000               assert(newin->jvms()->is_monitor_box(j), "sanity");
2001               // This assert also tests that nodes are BoxLock.
2002               assert(BoxLockNode::same_slot(n, m), "sanity");
2003               BoxLockNode* old_box = m->as_BoxLock();
2004               if (n->as_BoxLock()->is_unbalanced() && !old_box->is_unbalanced()) {
2005                 // Preserve Unbalanced status.
2006                 //
2007                 // `old_box` can have only Regular or Coarsened status
2008                 // because this code is executed only during Parse phase and
2009                 // Incremental Inlining before EA and Macro nodes elimination.
2010                 //
2011                 // Incremental Inlining is executed after IGVN optimizations
2012                 // during which BoxLock can be marked as Coarsened.
2013                 old_box->set_coarsened(); // Verifies state
2014                 old_box->set_unbalanced();
2015               }
2016               C->gvn_replace_by(n, m);
2017             } else if (!check_elide_phi || !target->can_elide_SEL_phi(j)) {
2018               phi = ensure_phi(j, nophi);
2019             }
2020           }
2021           break;
2022         }
2023       }
2024       // At this point, n might be top if:
2025       //  - there is no phi (because TypeFlow detected a conflict), or
2026       //  - the corresponding control edges is top (a dead incoming path)
2027       // It is a bug if we create a phi which sees a garbage value on a live path.
2028 
2029       // Merging two inline types?
2030       if (phi != nullptr && phi->is_InlineType()) {
2031         // Reload current state because it may have been updated by ensure_phi
2032         assert(phi == map()->in(j), "unexpected value in map");
2033         assert(phi->as_InlineType()->has_phi_inputs(r), "");
2034         InlineTypeNode* vtm = phi->as_InlineType(); // Current inline type
2035         InlineTypeNode* vtn = n->as_InlineType(); // Incoming inline type
2036         assert(vtm == phi, "Inline type should have Phi input");
2037 
2038 #ifdef ASSERT
2039         if (TraceOptoParse) {
2040           tty->print_cr("\nMerging inline types");
2041           tty->print_cr("Current:");
2042           vtm->dump(2);
2043           tty->print_cr("Incoming:");
2044           vtn->dump(2);
2045           tty->cr();
2046         }
2047 #endif
2048         // Do the merge
2049         vtm->merge_with(&_gvn, vtn, pnum, last_merge);
2050         if (last_merge) {
2051           map()->set_req(j, _gvn.transform(vtm));
2052           record_for_igvn(vtm);
2053         }
2054       } else if (phi != nullptr) {
2055         assert(n != top() || r->in(pnum) == top(), "live value must not be garbage");
2056         assert(phi->as_Phi()->region() == r, "");
2057         phi->set_req(pnum, n);  // Then add 'n' to the merge
2058         if (last_merge) {
2059           // Last merge for this Phi.
2060           // So far, Phis have had a reasonable type from ciTypeFlow.
2061           // Now _gvn will join that with the meet of current inputs.
2062           // BOTTOM is never permissible here, 'cause pessimistically
2063           // Phis of pointers cannot lose the basic pointer type.
2064           DEBUG_ONLY(const Type* bt1 = phi->bottom_type());
2065           assert(bt1 != Type::BOTTOM, "should not be building conflict phis");
2066           map()->set_req(j, _gvn.transform(phi));
2067           DEBUG_ONLY(const Type* bt2 = phi->bottom_type());
2068           assert(bt2->higher_equal_speculative(bt1), "must be consistent with type-flow");
2069           record_for_igvn(phi);
2070         }
2071       }
2072     } // End of for all values to be merged
2073 
2074     if (last_merge && !r->in(0)) {         // The occasional useless Region
2075       assert(control() == r, "");
2076       set_control(r->nonnull_req());
2077     }
2078 
2079     map()->merge_replaced_nodes_with(newin);
2080 
2081     // newin has been subsumed into the lazy merge, and is now dead.
2082     set_block(save_block);
2083 
2084     stop();                     // done with this guy, for now
2085   }
2086 
2087   if (TraceOptoParse) {
2088     tty->print_cr(" on path %d", pnum);
2089   }
2090 
2091   // Done with this parser state.
2092   assert(stopped(), "");
2093 }
2094 
2095 
2096 //--------------------------merge_memory_edges---------------------------------
2097 void Parse::merge_memory_edges(MergeMemNode* n, int pnum, bool nophi) {
2098   // (nophi means we must not create phis, because we already parsed here)
2099   assert(n != nullptr, "");
2100   // Merge the inputs to the MergeMems
2101   MergeMemNode* m = merged_memory();
2102 
2103   assert(control()->is_Region(), "must be merging to a region");
2104   RegionNode* r = control()->as_Region();
2105 
2106   PhiNode* base = nullptr;
2107   MergeMemNode* remerge = nullptr;
2108   for (MergeMemStream mms(m, n); mms.next_non_empty2(); ) {
2109     Node *p = mms.force_memory();
2110     Node *q = mms.memory2();
2111     if (mms.is_empty() && nophi) {
2112       // Trouble:  No new splits allowed after a loop body is parsed.
2113       // Instead, wire the new split into a MergeMem on the backedge.
2114       // The optimizer will sort it out, slicing the phi.
2115       if (remerge == nullptr) {
2116         guarantee(base != nullptr, "");
2117         assert(base->in(0) != nullptr, "should not be xformed away");
2118         remerge = MergeMemNode::make(base->in(pnum));
2119         gvn().set_type(remerge, Type::MEMORY);
2120         base->set_req(pnum, remerge);
2121       }
2122       remerge->set_memory_at(mms.alias_idx(), q);
2123       continue;
2124     }
2125     assert(!q->is_MergeMem(), "");
2126     PhiNode* phi;
2127     if (p != q) {
2128       phi = ensure_memory_phi(mms.alias_idx(), nophi);
2129     } else {
2130       if (p->is_Phi() && p->as_Phi()->region() == r)
2131         phi = p->as_Phi();
2132       else
2133         phi = nullptr;
2134     }
2135     // Insert q into local phi
2136     if (phi != nullptr) {
2137       assert(phi->region() == r, "");
2138       p = phi;
2139       phi->set_req(pnum, q);
2140       if (mms.at_base_memory()) {
2141         base = phi;  // delay transforming it
2142       } else if (pnum == 1) {
2143         record_for_igvn(phi);
2144         p = _gvn.transform(phi);
2145       }
2146       mms.set_memory(p);// store back through the iterator
2147     }
2148   }
2149   // Transform base last, in case we must fiddle with remerging.
2150   if (base != nullptr && pnum == 1) {
2151     record_for_igvn(base);
2152     m->set_base_memory(_gvn.transform(base));
2153   }
2154 }
2155 
2156 
2157 //------------------------ensure_phis_everywhere-------------------------------
2158 void Parse::ensure_phis_everywhere() {
2159   ensure_phi(TypeFunc::I_O);
2160 
2161   // Ensure a phi on all currently known memories.
2162   for (MergeMemStream mms(merged_memory()); mms.next_non_empty(); ) {
2163     ensure_memory_phi(mms.alias_idx());
2164     DEBUG_ONLY(mms.set_memory());  // keep the iterator happy
2165   }
2166 
2167   // Note:  This is our only chance to create phis for memory slices.
2168   // If we miss a slice that crops up later, it will have to be
2169   // merged into the base-memory phi that we are building here.
2170   // Later, the optimizer will comb out the knot, and build separate
2171   // phi-loops for each memory slice that matters.
2172 
2173   // Monitors must nest nicely and not get confused amongst themselves.
2174   // Phi-ify everything up to the monitors, though.
2175   uint monoff = map()->jvms()->monoff();
2176   uint nof_monitors = map()->jvms()->nof_monitors();
2177 
2178   assert(TypeFunc::Parms == map()->jvms()->locoff(), "parser map should contain only youngest jvms");
2179   bool check_elide_phi = block()->is_SEL_head();
2180   for (uint i = TypeFunc::Parms; i < monoff; i++) {
2181     if (!check_elide_phi || !block()->can_elide_SEL_phi(i)) {
2182       ensure_phi(i);
2183     }
2184   }
2185 
2186   // Even monitors need Phis, though they are well-structured.
2187   // This is true for OSR methods, and also for the rare cases where
2188   // a monitor object is the subject of a replace_in_map operation.
2189   // See bugs 4426707 and 5043395.
2190   for (uint m = 0; m < nof_monitors; m++) {
2191     ensure_phi(map()->jvms()->monitor_obj_offset(m));
2192   }
2193 }
2194 
2195 
2196 //-----------------------------add_new_path------------------------------------
2197 // Add a previously unaccounted predecessor to this block.
2198 int Parse::Block::add_new_path() {
2199   // If there is no map, return the lowest unused path number.
2200   if (!is_merged())  return pred_count()+1;  // there will be a map shortly
2201 
2202   SafePointNode* map = start_map();
2203   if (!map->control()->is_Region())
2204     return pred_count()+1;  // there may be a region some day
2205   RegionNode* r = map->control()->as_Region();
2206 
2207   // Add new path to the region.
2208   uint pnum = r->req();
2209   r->add_req(nullptr);
2210 
2211   for (uint i = 1; i < map->req(); i++) {
2212     Node* n = map->in(i);
2213     if (i == TypeFunc::Memory) {
2214       // Ensure a phi on all currently known memories.
2215       for (MergeMemStream mms(n->as_MergeMem()); mms.next_non_empty(); ) {
2216         Node* phi = mms.memory();
2217         if (phi->is_Phi() && phi->as_Phi()->region() == r) {
2218           assert(phi->req() == pnum, "must be same size as region");
2219           phi->add_req(nullptr);
2220         }
2221       }
2222     } else {
2223       if (n->is_Phi() && n->as_Phi()->region() == r) {
2224         assert(n->req() == pnum, "must be same size as region");
2225         n->add_req(nullptr);
2226       } else if (n->is_InlineType() && n->as_InlineType()->has_phi_inputs(r)) {
2227         n->as_InlineType()->add_new_path(r);
2228       }
2229     }
2230   }
2231 
2232   return pnum;
2233 }
2234 
2235 //------------------------------ensure_phi-------------------------------------
2236 // Turn the idx'th entry of the current map into a Phi
2237 Node* Parse::ensure_phi(int idx, bool nocreate) {
2238   SafePointNode* map = this->map();
2239   Node* region = map->control();
2240   assert(region->is_Region(), "");
2241 
2242   Node* o = map->in(idx);
2243   assert(o != nullptr, "");
2244 
2245   if (o == top())  return nullptr; // TOP always merges into TOP
2246 
2247   if (o->is_Phi() && o->as_Phi()->region() == region) {
2248     return o->as_Phi();
2249   }
2250   InlineTypeNode* vt = o->isa_InlineType();
2251   if (vt != nullptr && vt->has_phi_inputs(region)) {
2252     return vt;
2253   }
2254 
2255   // Now use a Phi here for merging
2256   assert(!nocreate, "Cannot build a phi for a block already parsed.");
2257   const JVMState* jvms = map->jvms();
2258   const Type* t = nullptr;
2259   if (jvms->is_loc(idx)) {
2260     t = block()->local_type_at(idx - jvms->locoff());
2261   } else if (jvms->is_stk(idx)) {
2262     t = block()->stack_type_at(idx - jvms->stkoff());
2263   } else if (jvms->is_mon(idx)) {
2264     assert(!jvms->is_monitor_box(idx), "no phis for boxes");
2265     t = TypeInstPtr::BOTTOM; // this is sufficient for a lock object
2266   } else if ((uint)idx < TypeFunc::Parms) {
2267     t = o->bottom_type();  // Type::RETURN_ADDRESS or such-like.
2268   } else {
2269     assert(false, "no type information for this phi");
2270   }
2271 
2272   // If the type falls to bottom, then this must be a local that
2273   // is already dead or is mixing ints and oops or some such.
2274   // Forcing it to top makes it go dead.
2275   if (t == Type::BOTTOM) {
2276     map->set_req(idx, top());
2277     return nullptr;
2278   }
2279 
2280   // Do not create phis for top either.
2281   // A top on a non-null control flow must be an unused even after the.phi.
2282   if (t == Type::TOP || t == Type::HALF) {
2283     map->set_req(idx, top());
2284     return nullptr;
2285   }
2286 
2287   if (vt != nullptr && t->is_inlinetypeptr()) {
2288     // Inline types are merged by merging their field values.
2289     // Create a cloned InlineTypeNode with phi inputs that
2290     // represents the merged inline type and update the map.
2291     vt = vt->clone_with_phis(&_gvn, region);
2292     map->set_req(idx, vt);
2293     return vt;
2294   } else {
2295     PhiNode* phi = PhiNode::make(region, o, t);
2296     gvn().set_type(phi, t);
2297     if (C->do_escape_analysis()) record_for_igvn(phi);
2298     map->set_req(idx, phi);
2299     return phi;
2300   }
2301 }
2302 
2303 //--------------------------ensure_memory_phi----------------------------------
2304 // Turn the idx'th slice of the current memory into a Phi
2305 PhiNode *Parse::ensure_memory_phi(int idx, bool nocreate) {
2306   MergeMemNode* mem = merged_memory();
2307   Node* region = control();
2308   assert(region->is_Region(), "");
2309 
2310   Node *o = (idx == Compile::AliasIdxBot)? mem->base_memory(): mem->memory_at(idx);
2311   assert(o != nullptr && o != top(), "");
2312 
2313   PhiNode* phi;
2314   if (o->is_Phi() && o->as_Phi()->region() == region) {
2315     phi = o->as_Phi();
2316     if (phi == mem->base_memory() && idx >= Compile::AliasIdxRaw) {
2317       // clone the shared base memory phi to make a new memory split
2318       assert(!nocreate, "Cannot build a phi for a block already parsed.");
2319       const Type* t = phi->bottom_type();
2320       const TypePtr* adr_type = C->get_adr_type(idx);
2321       phi = phi->slice_memory(adr_type);
2322       gvn().set_type(phi, t);
2323     }
2324     return phi;
2325   }
2326 
2327   // Now use a Phi here for merging
2328   assert(!nocreate, "Cannot build a phi for a block already parsed.");
2329   const Type* t = o->bottom_type();
2330   const TypePtr* adr_type = C->get_adr_type(idx);
2331   phi = PhiNode::make(region, o, t, adr_type);
2332   gvn().set_type(phi, t);
2333   if (idx == Compile::AliasIdxBot)
2334     mem->set_base_memory(phi);
2335   else
2336     mem->set_memory_at(idx, phi);
2337   return phi;
2338 }
2339 
2340 //------------------------------call_register_finalizer-----------------------
2341 // Check the klass of the receiver and call register_finalizer if the
2342 // class need finalization.
2343 void Parse::call_register_finalizer() {
2344   Node* receiver = local(0);
2345   assert(receiver != nullptr && receiver->bottom_type()->isa_instptr() != nullptr,
2346          "must have non-null instance type");
2347 
2348   const TypeInstPtr *tinst = receiver->bottom_type()->isa_instptr();
2349   if (tinst != nullptr && tinst->is_loaded() && !tinst->klass_is_exact()) {
2350     // The type isn't known exactly so see if CHA tells us anything.
2351     ciInstanceKlass* ik = tinst->instance_klass();
2352     if (!Dependencies::has_finalizable_subclass(ik)) {
2353       // No finalizable subclasses so skip the dynamic check.
2354       C->dependencies()->assert_has_no_finalizable_subclasses(ik);
2355       return;
2356     }
2357   }
2358 
2359   // Insert a dynamic test for whether the instance needs
2360   // finalization.  In general this will fold up since the concrete
2361   // class is often visible so the access flags are constant.
2362   Node* klass_addr = basic_plus_adr( receiver, receiver, oopDesc::klass_offset_in_bytes() );
2363   Node* klass = _gvn.transform(LoadKlassNode::make(_gvn, immutable_memory(), klass_addr, TypeInstPtr::KLASS));
2364 
2365   Node* access_flags_addr = basic_plus_adr(top(), klass, in_bytes(Klass::misc_flags_offset()));
2366   Node* access_flags = make_load(nullptr, access_flags_addr, TypeInt::UBYTE, T_BOOLEAN, MemNode::unordered);
2367 
2368   Node* mask  = _gvn.transform(new AndINode(access_flags, intcon(KlassFlags::_misc_has_finalizer)));
2369   Node* check = _gvn.transform(new CmpINode(mask, intcon(0)));
2370   Node* test  = _gvn.transform(new BoolNode(check, BoolTest::ne));
2371 
2372   IfNode* iff = create_and_map_if(control(), test, PROB_MAX, COUNT_UNKNOWN);
2373 
2374   RegionNode* result_rgn = new RegionNode(3);
2375   record_for_igvn(result_rgn);
2376 
2377   Node *skip_register = _gvn.transform(new IfFalseNode(iff));
2378   result_rgn->init_req(1, skip_register);
2379 
2380   Node *needs_register = _gvn.transform(new IfTrueNode(iff));
2381   set_control(needs_register);
2382   if (stopped()) {
2383     // There is no slow path.
2384     result_rgn->init_req(2, top());
2385   } else {
2386     Node *call = make_runtime_call(RC_NO_LEAF,
2387                                    OptoRuntime::register_finalizer_Type(),
2388                                    OptoRuntime::register_finalizer_Java(),
2389                                    nullptr, TypePtr::BOTTOM,
2390                                    receiver);
2391     make_slow_call_ex(call, env()->Throwable_klass(), true);
2392 
2393     Node* fast_io  = call->in(TypeFunc::I_O);
2394     Node* fast_mem = call->in(TypeFunc::Memory);
2395     // These two phis are pre-filled with copies of of the fast IO and Memory
2396     Node* io_phi   = PhiNode::make(result_rgn, fast_io,  Type::ABIO);
2397     Node* mem_phi  = PhiNode::make(result_rgn, fast_mem, Type::MEMORY, TypePtr::BOTTOM);
2398 
2399     result_rgn->init_req(2, control());
2400     io_phi    ->init_req(2, i_o());
2401     mem_phi   ->init_req(2, reset_memory());
2402 
2403     set_all_memory( _gvn.transform(mem_phi) );
2404     set_i_o(        _gvn.transform(io_phi) );
2405   }
2406 
2407   set_control( _gvn.transform(result_rgn) );
2408 }
2409 
2410 // Add check to deoptimize once holder klass is fully initialized.
2411 void Parse::clinit_deopt() {
2412   assert(C->has_method(), "only for normal compilations");
2413   assert(depth() == 1, "only for main compiled method");
2414   assert(is_normal_parse(), "no barrier needed on osr entry");
2415   assert(!method()->holder()->is_not_initialized(), "initialization should have been started");
2416 
2417   set_parse_bci(0);
2418 
2419   Node* holder = makecon(TypeKlassPtr::make(method()->holder(), Type::trust_interfaces));
2420   guard_klass_being_initialized(holder);
2421 }
2422 
2423 //------------------------------return_current---------------------------------
2424 // Append current _map to _exit_return
2425 void Parse::return_current(Node* value) {
2426   if (method()->intrinsic_id() == vmIntrinsics::_Object_init) {
2427     call_register_finalizer();
2428   }
2429 
2430   // frame pointer is always same, already captured
2431   if (value != nullptr) {
2432     Node* phi = _exits.argument(0);
2433     const Type* return_type = phi->bottom_type();
2434     const TypeInstPtr* tr = return_type->isa_instptr();
2435     if ((tf()->returns_inline_type_as_fields() || (_caller->has_method() && !Compile::current()->inlining_incrementally())) &&
2436         return_type->is_inlinetypeptr()) {
2437       // Inline type is returned as fields, make sure it is scalarized
2438       if (!value->is_InlineType()) {
2439         value = InlineTypeNode::make_from_oop(this, value, return_type->inline_klass());
2440       }
2441       if (!_caller->has_method() || Compile::current()->inlining_incrementally()) {
2442         // Returning from root or an incrementally inlined method. Make sure all non-flat
2443         // fields are buffered and re-execute if allocation triggers deoptimization.
2444         PreserveReexecuteState preexecs(this);
2445         assert(tf()->returns_inline_type_as_fields(), "must be returned as fields");
2446         jvms()->set_should_reexecute(true);
2447         inc_sp(1);
2448         value = value->as_InlineType()->allocate_fields(this);
2449       }
2450     } else if (value->is_InlineType()) {
2451       // Inline type is returned as oop, make sure it is buffered and re-execute
2452       // if allocation triggers deoptimization.
2453       PreserveReexecuteState preexecs(this);
2454       jvms()->set_should_reexecute(true);
2455       inc_sp(1);
2456       value = value->as_InlineType()->buffer(this);
2457     }
2458     // ...else
2459     // If returning oops to an interface-return, there is a silent free
2460     // cast from oop to interface allowed by the Verifier. Make it explicit here.
2461     phi->add_req(value);
2462   }
2463 
2464   // Do not set_parse_bci, so that return goo is credited to the return insn.
2465   set_bci(InvocationEntryBci);
2466   if (method()->is_synchronized()) {
2467     shared_unlock(_synch_lock->box_node(), _synch_lock->obj_node());
2468   }
2469   if (C->env()->dtrace_method_probes()) {
2470     make_dtrace_method_exit(method());
2471   }
2472 
2473   SafePointNode* exit_return = _exits.map();
2474   exit_return->in( TypeFunc::Control  )->add_req( control() );
2475   exit_return->in( TypeFunc::I_O      )->add_req( i_o    () );
2476   Node *mem = exit_return->in( TypeFunc::Memory   );
2477   for (MergeMemStream mms(mem->as_MergeMem(), merged_memory()); mms.next_non_empty2(); ) {
2478     if (mms.is_empty()) {
2479       // get a copy of the base memory, and patch just this one input
2480       const TypePtr* adr_type = mms.adr_type(C);
2481       Node* phi = mms.force_memory()->as_Phi()->slice_memory(adr_type);
2482       assert(phi->as_Phi()->region() == mms.base_memory()->in(0), "");
2483       gvn().set_type_bottom(phi);
2484       phi->del_req(phi->req()-1);  // prepare to re-patch
2485       mms.set_memory(phi);
2486     }
2487     mms.memory()->add_req(mms.memory2());
2488   }
2489 
2490   if (_first_return) {
2491     _exits.map()->transfer_replaced_nodes_from(map(), _new_idx);
2492     _first_return = false;
2493   } else {
2494     _exits.map()->merge_replaced_nodes_with(map());
2495   }
2496 
2497   stop_and_kill_map();          // This CFG path dies here
2498 }
2499 
2500 
2501 //------------------------------add_safepoint----------------------------------
2502 void Parse::add_safepoint() {
2503   uint parms = TypeFunc::Parms+1;
2504 
2505   // Clear out dead values from the debug info.
2506   kill_dead_locals();
2507 
2508   // Clone the JVM State
2509   SafePointNode *sfpnt = new SafePointNode(parms, nullptr);
2510 
2511   // Capture memory state BEFORE a SafePoint.  Since we can block at a
2512   // SafePoint we need our GC state to be safe; i.e. we need all our current
2513   // write barriers (card marks) to not float down after the SafePoint so we
2514   // must read raw memory.  Likewise we need all oop stores to match the card
2515   // marks.  If deopt can happen, we need ALL stores (we need the correct JVM
2516   // state on a deopt).
2517 
2518   // We do not need to WRITE the memory state after a SafePoint.  The control
2519   // edge will keep card-marks and oop-stores from floating up from below a
2520   // SafePoint and our true dependency added here will keep them from floating
2521   // down below a SafePoint.
2522 
2523   // Clone the current memory state
2524   Node* mem = MergeMemNode::make(map()->memory());
2525 
2526   mem = _gvn.transform(mem);
2527 
2528   // Pass control through the safepoint
2529   sfpnt->init_req(TypeFunc::Control  , control());
2530   // Fix edges normally used by a call
2531   sfpnt->init_req(TypeFunc::I_O      , top() );
2532   sfpnt->init_req(TypeFunc::Memory   , mem   );
2533   sfpnt->init_req(TypeFunc::ReturnAdr, top() );
2534   sfpnt->init_req(TypeFunc::FramePtr , top() );
2535 
2536   // Create a node for the polling address
2537   Node *polladr;
2538   Node *thread = _gvn.transform(new ThreadLocalNode());
2539   Node *polling_page_load_addr = _gvn.transform(basic_plus_adr(top(), thread, in_bytes(JavaThread::polling_page_offset())));
2540   polladr = make_load(control(), polling_page_load_addr, TypeRawPtr::BOTTOM, T_ADDRESS, MemNode::unordered);
2541   sfpnt->init_req(TypeFunc::Parms+0, _gvn.transform(polladr));
2542 
2543   // Fix up the JVM State edges
2544   add_safepoint_edges(sfpnt);
2545   Node *transformed_sfpnt = _gvn.transform(sfpnt);
2546   set_control(transformed_sfpnt);
2547 
2548   // Provide an edge from root to safepoint.  This makes the safepoint
2549   // appear useful until the parse has completed.
2550   if (transformed_sfpnt->is_SafePoint()) {
2551     assert(C->root() != nullptr, "Expect parse is still valid");
2552     C->root()->add_prec(transformed_sfpnt);
2553   }
2554 }
2555 
2556 #ifndef PRODUCT
2557 //------------------------show_parse_info--------------------------------------
2558 void Parse::show_parse_info() {
2559   InlineTree* ilt = nullptr;
2560   if (C->ilt() != nullptr) {
2561     JVMState* caller_jvms = is_osr_parse() ? caller()->caller() : caller();
2562     ilt = InlineTree::find_subtree_from_root(C->ilt(), caller_jvms, method());
2563   }
2564   if (PrintCompilation && Verbose) {
2565     if (depth() == 1) {
2566       if( ilt->count_inlines() ) {
2567         tty->print("    __inlined %d (%d bytes)", ilt->count_inlines(),
2568                      ilt->count_inline_bcs());
2569         tty->cr();
2570       }
2571     } else {
2572       if (method()->is_synchronized())         tty->print("s");
2573       if (method()->has_exception_handlers())  tty->print("!");
2574       // Check this is not the final compiled version
2575       if (C->trap_can_recompile()) {
2576         tty->print("-");
2577       } else {
2578         tty->print(" ");
2579       }
2580       method()->print_short_name();
2581       if (is_osr_parse()) {
2582         tty->print(" @ %d", osr_bci());
2583       }
2584       tty->print(" (%d bytes)",method()->code_size());
2585       if (ilt->count_inlines()) {
2586         tty->print(" __inlined %d (%d bytes)", ilt->count_inlines(),
2587                    ilt->count_inline_bcs());
2588       }
2589       tty->cr();
2590     }
2591   }
2592   if (PrintOpto && (depth() == 1 || PrintOptoInlining)) {
2593     // Print that we succeeded; suppress this message on the first osr parse.
2594 
2595     if (method()->is_synchronized())         tty->print("s");
2596     if (method()->has_exception_handlers())  tty->print("!");
2597     // Check this is not the final compiled version
2598     if (C->trap_can_recompile() && depth() == 1) {
2599       tty->print("-");
2600     } else {
2601       tty->print(" ");
2602     }
2603     if( depth() != 1 ) { tty->print("   "); }  // missing compile count
2604     for (int i = 1; i < depth(); ++i) { tty->print("  "); }
2605     method()->print_short_name();
2606     if (is_osr_parse()) {
2607       tty->print(" @ %d", osr_bci());
2608     }
2609     if (ilt->caller_bci() != -1) {
2610       tty->print(" @ %d", ilt->caller_bci());
2611     }
2612     tty->print(" (%d bytes)",method()->code_size());
2613     if (ilt->count_inlines()) {
2614       tty->print(" __inlined %d (%d bytes)", ilt->count_inlines(),
2615                  ilt->count_inline_bcs());
2616     }
2617     tty->cr();
2618   }
2619 }
2620 
2621 
2622 //------------------------------dump-------------------------------------------
2623 // Dump information associated with the bytecodes of current _method
2624 void Parse::dump() {
2625   if( method() != nullptr ) {
2626     // Iterate over bytecodes
2627     ciBytecodeStream iter(method());
2628     for( Bytecodes::Code bc = iter.next(); bc != ciBytecodeStream::EOBC() ; bc = iter.next() ) {
2629       dump_bci( iter.cur_bci() );
2630       tty->cr();
2631     }
2632   }
2633 }
2634 
2635 // Dump information associated with a byte code index, 'bci'
2636 void Parse::dump_bci(int bci) {
2637   // Output info on merge-points, cloning, and within _jsr..._ret
2638   // NYI
2639   tty->print(" bci:%d", bci);
2640 }
2641 
2642 #endif