1 /*
   2  * Copyright (c) 1997, 2019, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "compiler/compileLog.hpp"
  27 #include "interpreter/linkResolver.hpp"
  28 #include "memory/resourceArea.hpp"
  29 #include "oops/method.hpp"
  30 #include "opto/addnode.hpp"
  31 #include "opto/c2compiler.hpp"
  32 #include "opto/castnode.hpp"
  33 #include "opto/idealGraphPrinter.hpp"
  34 #include "opto/locknode.hpp"
  35 #include "opto/memnode.hpp"
  36 #include "opto/opaquenode.hpp"
  37 #include "opto/parse.hpp"
  38 #include "opto/rootnode.hpp"
  39 #include "opto/runtime.hpp"
  40 #include "runtime/arguments.hpp"
  41 #include "runtime/handles.inline.hpp"
  42 #include "runtime/safepointMechanism.hpp"
  43 #include "runtime/sharedRuntime.hpp"
  44 #include "utilities/copy.hpp"
  45 
  46 // Static array so we can figure out which bytecodes stop us from compiling
  47 // the most. Some of the non-static variables are needed in bytecodeInfo.cpp
  48 // and eventually should be encapsulated in a proper class (gri 8/18/98).
  49 
  50 #ifndef PRODUCT
  51 int nodes_created              = 0;
  52 int methods_parsed             = 0;
  53 int methods_seen               = 0;
  54 int blocks_parsed              = 0;
  55 int blocks_seen                = 0;
  56 
  57 int explicit_null_checks_inserted = 0;
  58 int explicit_null_checks_elided   = 0;
  59 int all_null_checks_found         = 0;
  60 int implicit_null_checks          = 0;
  61 
  62 bool Parse::BytecodeParseHistogram::_initialized = false;
  63 uint Parse::BytecodeParseHistogram::_bytecodes_parsed [Bytecodes::number_of_codes];
  64 uint Parse::BytecodeParseHistogram::_nodes_constructed[Bytecodes::number_of_codes];
  65 uint Parse::BytecodeParseHistogram::_nodes_transformed[Bytecodes::number_of_codes];
  66 uint Parse::BytecodeParseHistogram::_new_values       [Bytecodes::number_of_codes];
  67 
  68 //------------------------------print_statistics-------------------------------
  69 void Parse::print_statistics() {
  70   tty->print_cr("--- Compiler Statistics ---");
  71   tty->print("Methods seen: %d  Methods parsed: %d", methods_seen, methods_parsed);
  72   tty->print("  Nodes created: %d", nodes_created);
  73   tty->cr();
  74   if (methods_seen != methods_parsed) {
  75     tty->print_cr("Reasons for parse failures (NOT cumulative):");
  76   }
  77   tty->print_cr("Blocks parsed: %d  Blocks seen: %d", blocks_parsed, blocks_seen);
  78 
  79   if (explicit_null_checks_inserted) {
  80     tty->print_cr("%d original NULL checks - %d elided (%2d%%); optimizer leaves %d,",
  81                   explicit_null_checks_inserted, explicit_null_checks_elided,
  82                   (100*explicit_null_checks_elided)/explicit_null_checks_inserted,
  83                   all_null_checks_found);
  84   }
  85   if (all_null_checks_found) {
  86     tty->print_cr("%d made implicit (%2d%%)", implicit_null_checks,
  87                   (100*implicit_null_checks)/all_null_checks_found);
  88   }
  89   if (SharedRuntime::_implicit_null_throws) {
  90     tty->print_cr("%d implicit null exceptions at runtime",
  91                   SharedRuntime::_implicit_null_throws);
  92   }
  93 
  94   if (PrintParseStatistics && BytecodeParseHistogram::initialized()) {
  95     BytecodeParseHistogram::print();
  96   }
  97 }
  98 #endif
  99 
 100 //------------------------------ON STACK REPLACEMENT---------------------------
 101 
 102 // Construct a node which can be used to get incoming state for
 103 // on stack replacement.
 104 Node *Parse::fetch_interpreter_state(int index,
 105                                      BasicType bt,
 106                                      Node *local_addrs,
 107                                      Node *local_addrs_base) {
 108   Node *mem = memory(Compile::AliasIdxRaw);
 109   Node *adr = basic_plus_adr( local_addrs_base, local_addrs, -index*wordSize );
 110   Node *ctl = control();
 111 
 112   // Very similar to LoadNode::make, except we handle un-aligned longs and
 113   // doubles on Sparc.  Intel can handle them just fine directly.
 114   Node *l = NULL;
 115   switch (bt) {                // Signature is flattened
 116   case T_INT:     l = new LoadINode(ctl, mem, adr, TypeRawPtr::BOTTOM, TypeInt::INT,        MemNode::unordered); break;
 117   case T_FLOAT:   l = new LoadFNode(ctl, mem, adr, TypeRawPtr::BOTTOM, Type::FLOAT,         MemNode::unordered); break;
 118   case T_ADDRESS: l = new LoadPNode(ctl, mem, adr, TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM,  MemNode::unordered); break;
 119   case T_OBJECT:  l = new LoadPNode(ctl, mem, adr, TypeRawPtr::BOTTOM, TypeInstPtr::BOTTOM, MemNode::unordered); break;
 120   case T_LONG:
 121   case T_DOUBLE: {
 122     // Since arguments are in reverse order, the argument address 'adr'
 123     // refers to the back half of the long/double.  Recompute adr.
 124     adr = basic_plus_adr(local_addrs_base, local_addrs, -(index+1)*wordSize);
 125     if (Matcher::misaligned_doubles_ok) {
 126       l = (bt == T_DOUBLE)
 127         ? (Node*)new LoadDNode(ctl, mem, adr, TypeRawPtr::BOTTOM, Type::DOUBLE, MemNode::unordered)
 128         : (Node*)new LoadLNode(ctl, mem, adr, TypeRawPtr::BOTTOM, TypeLong::LONG, MemNode::unordered);
 129     } else {
 130       l = (bt == T_DOUBLE)
 131         ? (Node*)new LoadD_unalignedNode(ctl, mem, adr, TypeRawPtr::BOTTOM, MemNode::unordered)
 132         : (Node*)new LoadL_unalignedNode(ctl, mem, adr, TypeRawPtr::BOTTOM, MemNode::unordered);
 133     }
 134     break;
 135   }
 136   default: ShouldNotReachHere();
 137   }
 138   return _gvn.transform(l);
 139 }
 140 
 141 // Helper routine to prevent the interpreter from handing
 142 // unexpected typestate to an OSR method.
 143 // The Node l is a value newly dug out of the interpreter frame.
 144 // The type is the type predicted by ciTypeFlow.  Note that it is
 145 // not a general type, but can only come from Type::get_typeflow_type.
 146 // The safepoint is a map which will feed an uncommon trap.
 147 Node* Parse::check_interpreter_type(Node* l, const Type* type,
 148                                     SafePointNode* &bad_type_exit) {
 149 
 150   const TypeOopPtr* tp = type->isa_oopptr();
 151 
 152   // TypeFlow may assert null-ness if a type appears unloaded.
 153   if (type == TypePtr::NULL_PTR ||
 154       (tp != NULL && !tp->klass()->is_loaded())) {
 155     // Value must be null, not a real oop.
 156     Node* chk = _gvn.transform( new CmpPNode(l, null()) );
 157     Node* tst = _gvn.transform( new BoolNode(chk, BoolTest::eq) );
 158     IfNode* iff = create_and_map_if(control(), tst, PROB_MAX, COUNT_UNKNOWN);
 159     set_control(_gvn.transform( new IfTrueNode(iff) ));
 160     Node* bad_type = _gvn.transform( new IfFalseNode(iff) );
 161     bad_type_exit->control()->add_req(bad_type);
 162     l = null();
 163   }
 164 
 165   // Typeflow can also cut off paths from the CFG, based on
 166   // types which appear unloaded, or call sites which appear unlinked.
 167   // When paths are cut off, values at later merge points can rise
 168   // toward more specific classes.  Make sure these specific classes
 169   // are still in effect.
 170   if (tp != NULL && tp->klass() != C->env()->Object_klass()) {
 171     // TypeFlow asserted a specific object type.  Value must have that type.
 172     Node* bad_type_ctrl = NULL;
 173     l = gen_checkcast(l, makecon(TypeKlassPtr::make(tp->klass())), &bad_type_ctrl);
 174     bad_type_exit->control()->add_req(bad_type_ctrl);
 175   }
 176 
 177   BasicType bt_l = _gvn.type(l)->basic_type();
 178   BasicType bt_t = type->basic_type();
 179   assert(_gvn.type(l)->higher_equal(type), "must constrain OSR typestate");
 180   return l;
 181 }
 182 
 183 // Helper routine which sets up elements of the initial parser map when
 184 // performing a parse for on stack replacement.  Add values into map.
 185 // The only parameter contains the address of a interpreter arguments.
 186 void Parse::load_interpreter_state(Node* osr_buf) {
 187   int index;
 188   int max_locals = jvms()->loc_size();
 189   int max_stack  = jvms()->stk_size();
 190 
 191 
 192   // Mismatch between method and jvms can occur since map briefly held
 193   // an OSR entry state (which takes up one RawPtr word).
 194   assert(max_locals == method()->max_locals(), "sanity");
 195   assert(max_stack  >= method()->max_stack(),  "sanity");
 196   assert((int)jvms()->endoff() == TypeFunc::Parms + max_locals + max_stack, "sanity");
 197   assert((int)jvms()->endoff() == (int)map()->req(), "sanity");
 198 
 199   // Find the start block.
 200   Block* osr_block = start_block();
 201   assert(osr_block->start() == osr_bci(), "sanity");
 202 
 203   // Set initial BCI.
 204   set_parse_bci(osr_block->start());
 205 
 206   // Set initial stack depth.
 207   set_sp(osr_block->start_sp());
 208 
 209   // Check bailouts.  We currently do not perform on stack replacement
 210   // of loops in catch blocks or loops which branch with a non-empty stack.
 211   if (sp() != 0) {
 212     C->record_method_not_compilable("OSR starts with non-empty stack");
 213     return;
 214   }
 215   // Do not OSR inside finally clauses:
 216   if (osr_block->has_trap_at(osr_block->start())) {
 217     C->record_method_not_compilable("OSR starts with an immediate trap");
 218     return;
 219   }
 220 
 221   // Commute monitors from interpreter frame to compiler frame.
 222   assert(jvms()->monitor_depth() == 0, "should be no active locks at beginning of osr");
 223   int mcnt = osr_block->flow()->monitor_count();
 224   Node *monitors_addr = basic_plus_adr(osr_buf, osr_buf, (max_locals+mcnt*2-1)*wordSize);
 225   for (index = 0; index < mcnt; index++) {
 226     // Make a BoxLockNode for the monitor.
 227     Node *box = _gvn.transform(new BoxLockNode(next_monitor()));
 228 
 229 
 230     // Displaced headers and locked objects are interleaved in the
 231     // temp OSR buffer.  We only copy the locked objects out here.
 232     // Fetch the locked object from the OSR temp buffer and copy to our fastlock node.
 233     Node *lock_object = fetch_interpreter_state(index*2, T_OBJECT, monitors_addr, osr_buf);
 234     // Try and copy the displaced header to the BoxNode
 235     Node *displaced_hdr = fetch_interpreter_state((index*2) + 1, T_ADDRESS, monitors_addr, osr_buf);
 236 
 237 
 238     store_to_memory(control(), box, displaced_hdr, T_ADDRESS, Compile::AliasIdxRaw, MemNode::unordered);
 239 
 240     // Build a bogus FastLockNode (no code will be generated) and push the
 241     // monitor into our debug info.
 242     const FastLockNode *flock = _gvn.transform(new FastLockNode( 0, lock_object, box ))->as_FastLock();
 243     map()->push_monitor(flock);
 244 
 245     // If the lock is our method synchronization lock, tuck it away in
 246     // _sync_lock for return and rethrow exit paths.
 247     if (index == 0 && method()->is_synchronized()) {
 248       _synch_lock = flock;
 249     }
 250   }
 251 
 252   // Use the raw liveness computation to make sure that unexpected
 253   // values don't propagate into the OSR frame.
 254   MethodLivenessResult live_locals = method()->liveness_at_bci(osr_bci());
 255   if (!live_locals.is_valid()) {
 256     // Degenerate or breakpointed method.
 257     C->record_method_not_compilable("OSR in empty or breakpointed method");
 258     return;
 259   }
 260 
 261   // Extract the needed locals from the interpreter frame.
 262   Node *locals_addr = basic_plus_adr(osr_buf, osr_buf, (max_locals-1)*wordSize);
 263 
 264   // find all the locals that the interpreter thinks contain live oops
 265   const ResourceBitMap live_oops = method()->live_local_oops_at_bci(osr_bci());
 266   for (index = 0; index < max_locals; index++) {
 267 
 268     if (!live_locals.at(index)) {
 269       continue;
 270     }
 271 
 272     const Type *type = osr_block->local_type_at(index);
 273 
 274     if (type->isa_oopptr() != NULL) {
 275 
 276       // 6403625: Verify that the interpreter oopMap thinks that the oop is live
 277       // else we might load a stale oop if the MethodLiveness disagrees with the
 278       // result of the interpreter. If the interpreter says it is dead we agree
 279       // by making the value go to top.
 280       //
 281 
 282       if (!live_oops.at(index)) {
 283         if (C->log() != NULL) {
 284           C->log()->elem("OSR_mismatch local_index='%d'",index);
 285         }
 286         set_local(index, null());
 287         // and ignore it for the loads
 288         continue;
 289       }
 290     }
 291 
 292     // Filter out TOP, HALF, and BOTTOM.  (Cf. ensure_phi.)
 293     if (type == Type::TOP || type == Type::HALF) {
 294       continue;
 295     }
 296     // If the type falls to bottom, then this must be a local that
 297     // is mixing ints and oops or some such.  Forcing it to top
 298     // makes it go dead.
 299     if (type == Type::BOTTOM) {
 300       continue;
 301     }
 302     // Construct code to access the appropriate local.
 303     BasicType bt = type->basic_type();
 304     if (type == TypePtr::NULL_PTR) {
 305       // Ptr types are mixed together with T_ADDRESS but NULL is
 306       // really for T_OBJECT types so correct it.
 307       bt = T_OBJECT;
 308     }
 309     Node *value = fetch_interpreter_state(index, bt, locals_addr, osr_buf);
 310     set_local(index, value);
 311   }
 312 
 313   // Extract the needed stack entries from the interpreter frame.
 314   for (index = 0; index < sp(); index++) {
 315     const Type *type = osr_block->stack_type_at(index);
 316     if (type != Type::TOP) {
 317       // Currently the compiler bails out when attempting to on stack replace
 318       // at a bci with a non-empty stack.  We should not reach here.
 319       ShouldNotReachHere();
 320     }
 321   }
 322 
 323   // End the OSR migration
 324   make_runtime_call(RC_LEAF, OptoRuntime::osr_end_Type(),
 325                     CAST_FROM_FN_PTR(address, SharedRuntime::OSR_migration_end),
 326                     "OSR_migration_end", TypeRawPtr::BOTTOM,
 327                     osr_buf);
 328 
 329   // Now that the interpreter state is loaded, make sure it will match
 330   // at execution time what the compiler is expecting now:
 331   SafePointNode* bad_type_exit = clone_map();
 332   bad_type_exit->set_control(new RegionNode(1));
 333 
 334   assert(osr_block->flow()->jsrs()->size() == 0, "should be no jsrs live at osr point");
 335   for (index = 0; index < max_locals; index++) {
 336     if (stopped())  break;
 337     Node* l = local(index);
 338     if (l->is_top())  continue;  // nothing here
 339     const Type *type = osr_block->local_type_at(index);
 340     if (type->isa_oopptr() != NULL) {
 341       if (!live_oops.at(index)) {
 342         // skip type check for dead oops
 343         continue;
 344       }
 345     }
 346     if (osr_block->flow()->local_type_at(index)->is_return_address()) {
 347       // In our current system it's illegal for jsr addresses to be
 348       // live into an OSR entry point because the compiler performs
 349       // inlining of jsrs.  ciTypeFlow has a bailout that detect this
 350       // case and aborts the compile if addresses are live into an OSR
 351       // entry point.  Because of that we can assume that any address
 352       // locals at the OSR entry point are dead.  Method liveness
 353       // isn't precise enought to figure out that they are dead in all
 354       // cases so simply skip checking address locals all
 355       // together. Any type check is guaranteed to fail since the
 356       // interpreter type is the result of a load which might have any
 357       // value and the expected type is a constant.
 358       continue;
 359     }
 360     set_local(index, check_interpreter_type(l, type, bad_type_exit));
 361   }
 362 
 363   for (index = 0; index < sp(); index++) {
 364     if (stopped())  break;
 365     Node* l = stack(index);
 366     if (l->is_top())  continue;  // nothing here
 367     const Type *type = osr_block->stack_type_at(index);
 368     set_stack(index, check_interpreter_type(l, type, bad_type_exit));
 369   }
 370 
 371   if (bad_type_exit->control()->req() > 1) {
 372     // Build an uncommon trap here, if any inputs can be unexpected.
 373     bad_type_exit->set_control(_gvn.transform( bad_type_exit->control() ));
 374     record_for_igvn(bad_type_exit->control());
 375     SafePointNode* types_are_good = map();
 376     set_map(bad_type_exit);
 377     // The unexpected type happens because a new edge is active
 378     // in the CFG, which typeflow had previously ignored.
 379     // E.g., Object x = coldAtFirst() && notReached()? "str": new Integer(123).
 380     // This x will be typed as Integer if notReached is not yet linked.
 381     // It could also happen due to a problem in ciTypeFlow analysis.
 382     uncommon_trap(Deoptimization::Reason_constraint,
 383                   Deoptimization::Action_reinterpret);
 384     set_map(types_are_good);
 385   }
 386 }
 387 
 388 //------------------------------Parse------------------------------------------
 389 // Main parser constructor.
 390 Parse::Parse(JVMState* caller, ciMethod* parse_method, float expected_uses)
 391   : _exits(caller)
 392 {
 393   // Init some variables
 394   _caller = caller;
 395   _method = parse_method;
 396   _expected_uses = expected_uses;
 397   _depth = 1 + (caller->has_method() ? caller->depth() : 0);
 398   _wrote_final = false;
 399   _wrote_volatile = false;
 400   _wrote_stable = false;
 401   _wrote_fields = false;
 402   _alloc_with_final = NULL;
 403   _entry_bci = InvocationEntryBci;
 404   _tf = NULL;
 405   _block = NULL;
 406   _first_return = true;
 407   _replaced_nodes_for_exceptions = false;
 408   _new_idx = C->unique();
 409   debug_only(_block_count = -1);
 410   debug_only(_blocks = (Block*)-1);
 411 #ifndef PRODUCT
 412   if (PrintCompilation || PrintOpto) {
 413     // Make sure I have an inline tree, so I can print messages about it.
 414     JVMState* ilt_caller = is_osr_parse() ? caller->caller() : caller;
 415     InlineTree::find_subtree_from_root(C->ilt(), ilt_caller, parse_method);
 416   }
 417   _max_switch_depth = 0;
 418   _est_switch_depth = 0;
 419 #endif
 420 
 421   if (parse_method->has_reserved_stack_access()) {
 422     C->set_has_reserved_stack_access(true);
 423   }
 424 
 425   _tf = TypeFunc::make(method());
 426   _iter.reset_to_method(method());
 427   _flow = method()->get_flow_analysis();
 428   if (_flow->failing()) {
 429     C->record_method_not_compilable(_flow->failure_reason());
 430   }
 431 
 432 #ifndef PRODUCT
 433   if (_flow->has_irreducible_entry()) {
 434     C->set_parsed_irreducible_loop(true);
 435   }
 436 #endif
 437 
 438   if (_expected_uses <= 0) {
 439     _prof_factor = 1;
 440   } else {
 441     float prof_total = parse_method->interpreter_invocation_count();
 442     if (prof_total <= _expected_uses) {
 443       _prof_factor = 1;
 444     } else {
 445       _prof_factor = _expected_uses / prof_total;
 446     }
 447   }
 448 
 449   CompileLog* log = C->log();
 450   if (log != NULL) {
 451     log->begin_head("parse method='%d' uses='%f'",
 452                     log->identify(parse_method), expected_uses);
 453     if (depth() == 1 && C->is_osr_compilation()) {
 454       log->print(" osr_bci='%d'", C->entry_bci());
 455     }
 456     log->stamp();
 457     log->end_head();
 458   }
 459 
 460   // Accumulate deoptimization counts.
 461   // (The range_check and store_check counts are checked elsewhere.)
 462   ciMethodData* md = method()->method_data();
 463   for (uint reason = 0; reason < md->trap_reason_limit(); reason++) {
 464     uint md_count = md->trap_count(reason);
 465     if (md_count != 0) {
 466       if (md_count == md->trap_count_limit())
 467         md_count += md->overflow_trap_count();
 468       uint total_count = C->trap_count(reason);
 469       uint old_count   = total_count;
 470       total_count += md_count;
 471       // Saturate the add if it overflows.
 472       if (total_count < old_count || total_count < md_count)
 473         total_count = (uint)-1;
 474       C->set_trap_count(reason, total_count);
 475       if (log != NULL)
 476         log->elem("observe trap='%s' count='%d' total='%d'",
 477                   Deoptimization::trap_reason_name(reason),
 478                   md_count, total_count);
 479     }
 480   }
 481   // Accumulate total sum of decompilations, also.
 482   C->set_decompile_count(C->decompile_count() + md->decompile_count());
 483 
 484   _count_invocations = C->do_count_invocations();
 485   _method_data_update = C->do_method_data_update();
 486 
 487   if (log != NULL && method()->has_exception_handlers()) {
 488     log->elem("observe that='has_exception_handlers'");
 489   }
 490 
 491   assert(InlineTree::check_can_parse(method()) == NULL, "Can not parse this method, cutout earlier");
 492   assert(method()->has_balanced_monitors(), "Can not parse unbalanced monitors, cutout earlier");
 493 
 494   // Always register dependence if JVMTI is enabled, because
 495   // either breakpoint setting or hotswapping of methods may
 496   // cause deoptimization.
 497   if (C->env()->jvmti_can_hotswap_or_post_breakpoint()) {
 498     C->dependencies()->assert_evol_method(method());
 499   }
 500 
 501   NOT_PRODUCT(methods_seen++);
 502 
 503   // Do some special top-level things.
 504   if (depth() == 1 && C->is_osr_compilation()) {
 505     _entry_bci = C->entry_bci();
 506     _flow = method()->get_osr_flow_analysis(osr_bci());
 507     if (_flow->failing()) {
 508       C->record_method_not_compilable(_flow->failure_reason());
 509 #ifndef PRODUCT
 510       if (PrintOpto && (Verbose || WizardMode)) {
 511         tty->print_cr("OSR @%d type flow bailout: %s", _entry_bci, _flow->failure_reason());
 512         if (Verbose) {
 513           method()->print();
 514           method()->print_codes();
 515           _flow->print();
 516         }
 517       }
 518 #endif
 519     }
 520     _tf = C->tf();     // the OSR entry type is different
 521   }
 522 
 523 #ifdef ASSERT
 524   if (depth() == 1) {
 525     assert(C->is_osr_compilation() == this->is_osr_parse(), "OSR in sync");
 526     if (C->tf() != tf()) {
 527       assert(C->env()->system_dictionary_modification_counter_changed(),
 528              "Must invalidate if TypeFuncs differ");
 529     }
 530   } else {
 531     assert(!this->is_osr_parse(), "no recursive OSR");
 532   }
 533 #endif
 534 
 535 #ifndef PRODUCT
 536   methods_parsed++;
 537   // add method size here to guarantee that inlined methods are added too
 538   if (CITime)
 539     _total_bytes_compiled += method()->code_size();
 540 
 541   show_parse_info();
 542 #endif
 543 
 544   if (failing()) {
 545     if (log)  log->done("parse");
 546     return;
 547   }
 548 
 549   gvn().set_type(root(), root()->bottom_type());
 550   gvn().transform(top());
 551 
 552   // Import the results of the ciTypeFlow.
 553   init_blocks();
 554 
 555   // Merge point for all normal exits
 556   build_exits();
 557 
 558   // Setup the initial JVM state map.
 559   SafePointNode* entry_map = create_entry_map();
 560 
 561   // Check for bailouts during map initialization
 562   if (failing() || entry_map == NULL) {
 563     if (log)  log->done("parse");
 564     return;
 565   }
 566 
 567   Node_Notes* caller_nn = C->default_node_notes();
 568   // Collect debug info for inlined calls unless -XX:-DebugInlinedCalls.
 569   if (DebugInlinedCalls || depth() == 1) {
 570     C->set_default_node_notes(make_node_notes(caller_nn));
 571   }
 572 
 573   if (is_osr_parse()) {
 574     Node* osr_buf = entry_map->in(TypeFunc::Parms+0);
 575     entry_map->set_req(TypeFunc::Parms+0, top());
 576     set_map(entry_map);
 577     load_interpreter_state(osr_buf);
 578   } else {
 579     set_map(entry_map);
 580     do_method_entry();
 581     if (depth() == 1 && C->age_code()) {
 582       decrement_age();
 583     }
 584   }
 585 
 586   if (depth() == 1 && !failing()) {
 587     if (C->clinit_barrier_on_entry()) {
 588       // Add check to deoptimize the nmethod once the holder class is fully initialized
 589       clinit_deopt();
 590     }
 591 
 592     // Add check to deoptimize the nmethod if RTM state was changed
 593     rtm_deopt();
 594   }
 595 
 596   // Check for bailouts during method entry or RTM state check setup.
 597   if (failing()) {
 598     if (log)  log->done("parse");
 599     C->set_default_node_notes(caller_nn);
 600     return;
 601   }
 602 
 603   entry_map = map();  // capture any changes performed by method setup code
 604   assert(jvms()->endoff() == map()->req(), "map matches JVMS layout");
 605 
 606   // We begin parsing as if we have just encountered a jump to the
 607   // method entry.
 608   Block* entry_block = start_block();
 609   assert(entry_block->start() == (is_osr_parse() ? osr_bci() : 0), "");
 610   set_map_clone(entry_map);
 611   merge_common(entry_block, entry_block->next_path_num());
 612 
 613 #ifndef PRODUCT
 614   BytecodeParseHistogram *parse_histogram_obj = new (C->env()->arena()) BytecodeParseHistogram(this, C);
 615   set_parse_histogram( parse_histogram_obj );
 616 #endif
 617 
 618   // Parse all the basic blocks.
 619   do_all_blocks();
 620 
 621   C->set_default_node_notes(caller_nn);
 622 
 623   // Check for bailouts during conversion to graph
 624   if (failing()) {
 625     if (log)  log->done("parse");
 626     return;
 627   }
 628 
 629   // Fix up all exiting control flow.
 630   set_map(entry_map);
 631   do_exits();
 632 
 633   if (log)  log->done("parse nodes='%d' live='%d' memory='" SIZE_FORMAT "'",
 634                       C->unique(), C->live_nodes(), C->node_arena()->used());
 635 }
 636 
 637 //---------------------------do_all_blocks-------------------------------------
 638 void Parse::do_all_blocks() {
 639   bool has_irreducible = flow()->has_irreducible_entry();
 640 
 641   // Walk over all blocks in Reverse Post-Order.
 642   while (true) {
 643     bool progress = false;
 644     for (int rpo = 0; rpo < block_count(); rpo++) {
 645       Block* block = rpo_at(rpo);
 646 
 647       if (block->is_parsed()) continue;
 648 
 649       if (!block->is_merged()) {
 650         // Dead block, no state reaches this block
 651         continue;
 652       }
 653 
 654       // Prepare to parse this block.
 655       load_state_from(block);
 656 
 657       if (stopped()) {
 658         // Block is dead.
 659         continue;
 660       }
 661 
 662       NOT_PRODUCT(blocks_parsed++);
 663 
 664       progress = true;
 665       if (block->is_loop_head() || block->is_handler() || (has_irreducible && !block->is_ready())) {
 666         // Not all preds have been parsed.  We must build phis everywhere.
 667         // (Note that dead locals do not get phis built, ever.)
 668         ensure_phis_everywhere();
 669 
 670         if (block->is_SEL_head()) {
 671           // Add predicate to single entry (not irreducible) loop head.
 672           assert(!block->has_merged_backedge(), "only entry paths should be merged for now");
 673           // Predicates may have been added after a dominating if
 674           if (!block->has_predicates()) {
 675             // Need correct bci for predicate.
 676             // It is fine to set it here since do_one_block() will set it anyway.
 677             set_parse_bci(block->start());
 678             add_predicate();
 679           }
 680           // Add new region for back branches.
 681           int edges = block->pred_count() - block->preds_parsed() + 1; // +1 for original region
 682           RegionNode *r = new RegionNode(edges+1);
 683           _gvn.set_type(r, Type::CONTROL);
 684           record_for_igvn(r);
 685           r->init_req(edges, control());
 686           set_control(r);
 687           // Add new phis.
 688           ensure_phis_everywhere();
 689         }
 690 
 691         // Leave behind an undisturbed copy of the map, for future merges.
 692         set_map(clone_map());
 693       }
 694 
 695       if (control()->is_Region() && !block->is_loop_head() && !has_irreducible && !block->is_handler()) {
 696         // In the absence of irreducible loops, the Region and Phis
 697         // associated with a merge that doesn't involve a backedge can
 698         // be simplified now since the RPO parsing order guarantees
 699         // that any path which was supposed to reach here has already
 700         // been parsed or must be dead.
 701         Node* c = control();
 702         Node* result = _gvn.transform_no_reclaim(control());
 703         if (c != result && TraceOptoParse) {
 704           tty->print_cr("Block #%d replace %d with %d", block->rpo(), c->_idx, result->_idx);
 705         }
 706         if (result != top()) {
 707           record_for_igvn(result);
 708         }
 709       }
 710 
 711       // Parse the block.
 712       do_one_block();
 713 
 714       // Check for bailouts.
 715       if (failing())  return;
 716     }
 717 
 718     // with irreducible loops multiple passes might be necessary to parse everything
 719     if (!has_irreducible || !progress) {
 720       break;
 721     }
 722   }
 723 
 724 #ifndef PRODUCT
 725   blocks_seen += block_count();
 726 
 727   // Make sure there are no half-processed blocks remaining.
 728   // Every remaining unprocessed block is dead and may be ignored now.
 729   for (int rpo = 0; rpo < block_count(); rpo++) {
 730     Block* block = rpo_at(rpo);
 731     if (!block->is_parsed()) {
 732       if (TraceOptoParse) {
 733         tty->print_cr("Skipped dead block %d at bci:%d", rpo, block->start());
 734       }
 735       assert(!block->is_merged(), "no half-processed blocks");
 736     }
 737   }
 738 #endif
 739 }
 740 
 741 static Node* mask_int_value(Node* v, BasicType bt, PhaseGVN* gvn) {
 742   switch (bt) {
 743   case T_BYTE:
 744     v = gvn->transform(new LShiftINode(v, gvn->intcon(24)));
 745     v = gvn->transform(new RShiftINode(v, gvn->intcon(24)));
 746     break;
 747   case T_SHORT:
 748     v = gvn->transform(new LShiftINode(v, gvn->intcon(16)));
 749     v = gvn->transform(new RShiftINode(v, gvn->intcon(16)));
 750     break;
 751   case T_CHAR:
 752     v = gvn->transform(new AndINode(v, gvn->intcon(0xFFFF)));
 753     break;
 754   case T_BOOLEAN:
 755     v = gvn->transform(new AndINode(v, gvn->intcon(0x1)));
 756     break;
 757   default:
 758     break;
 759   }
 760   return v;
 761 }
 762 
 763 //-------------------------------build_exits----------------------------------
 764 // Build normal and exceptional exit merge points.
 765 void Parse::build_exits() {
 766   // make a clone of caller to prevent sharing of side-effects
 767   _exits.set_map(_exits.clone_map());
 768   _exits.clean_stack(_exits.sp());
 769   _exits.sync_jvms();
 770 
 771   RegionNode* region = new RegionNode(1);
 772   record_for_igvn(region);
 773   gvn().set_type_bottom(region);
 774   _exits.set_control(region);
 775 
 776   // Note:  iophi and memphi are not transformed until do_exits.
 777   Node* iophi  = new PhiNode(region, Type::ABIO);
 778   Node* memphi = new PhiNode(region, Type::MEMORY, TypePtr::BOTTOM);
 779   gvn().set_type_bottom(iophi);
 780   gvn().set_type_bottom(memphi);
 781   _exits.set_i_o(iophi);
 782   _exits.set_all_memory(memphi);
 783 
 784   // Add a return value to the exit state.  (Do not push it yet.)
 785   if (tf()->range()->cnt() > TypeFunc::Parms) {
 786     const Type* ret_type = tf()->range()->field_at(TypeFunc::Parms);
 787     if (ret_type->isa_int()) {
 788       BasicType ret_bt = method()->return_type()->basic_type();
 789       if (ret_bt == T_BOOLEAN ||
 790           ret_bt == T_CHAR ||
 791           ret_bt == T_BYTE ||
 792           ret_bt == T_SHORT) {
 793         ret_type = TypeInt::INT;
 794       }
 795     }
 796 
 797     // Don't "bind" an unloaded return klass to the ret_phi. If the klass
 798     // becomes loaded during the subsequent parsing, the loaded and unloaded
 799     // types will not join when we transform and push in do_exits().
 800     const TypeOopPtr* ret_oop_type = ret_type->isa_oopptr();
 801     if (ret_oop_type && !ret_oop_type->klass()->is_loaded()) {
 802       ret_type = TypeOopPtr::BOTTOM;
 803     }
 804     int         ret_size = type2size[ret_type->basic_type()];
 805     Node*       ret_phi  = new PhiNode(region, ret_type);
 806     gvn().set_type_bottom(ret_phi);
 807     _exits.ensure_stack(ret_size);
 808     assert((int)(tf()->range()->cnt() - TypeFunc::Parms) == ret_size, "good tf range");
 809     assert(method()->return_type()->size() == ret_size, "tf agrees w/ method");
 810     _exits.set_argument(0, ret_phi);  // here is where the parser finds it
 811     // Note:  ret_phi is not yet pushed, until do_exits.
 812   }
 813 }
 814 
 815 
 816 //----------------------------build_start_state-------------------------------
 817 // Construct a state which contains only the incoming arguments from an
 818 // unknown caller.  The method & bci will be NULL & InvocationEntryBci.
 819 JVMState* Compile::build_start_state(StartNode* start, const TypeFunc* tf) {
 820   int        arg_size = tf->domain()->cnt();
 821   int        max_size = MAX2(arg_size, (int)tf->range()->cnt());
 822   JVMState*  jvms     = new (this) JVMState(max_size - TypeFunc::Parms);
 823   SafePointNode* map  = new SafePointNode(max_size, NULL);
 824   record_for_igvn(map);
 825   assert(arg_size == TypeFunc::Parms + (is_osr_compilation() ? 1 : method()->arg_size()), "correct arg_size");
 826   Node_Notes* old_nn = default_node_notes();
 827   if (old_nn != NULL && has_method()) {
 828     Node_Notes* entry_nn = old_nn->clone(this);
 829     JVMState* entry_jvms = new(this) JVMState(method(), old_nn->jvms());
 830     entry_jvms->set_offsets(0);
 831     entry_jvms->set_bci(entry_bci());
 832     entry_nn->set_jvms(entry_jvms);
 833     set_default_node_notes(entry_nn);
 834   }
 835   uint i;
 836   for (i = 0; i < (uint)arg_size; i++) {
 837     Node* parm = initial_gvn()->transform(new ParmNode(start, i));
 838     map->init_req(i, parm);
 839     // Record all these guys for later GVN.
 840     record_for_igvn(parm);
 841   }
 842   for (; i < map->req(); i++) {
 843     map->init_req(i, top());
 844   }
 845   assert(jvms->argoff() == TypeFunc::Parms, "parser gets arguments here");
 846   set_default_node_notes(old_nn);
 847   map->set_jvms(jvms);
 848   jvms->set_map(map);
 849   return jvms;
 850 }
 851 
 852 //-----------------------------make_node_notes---------------------------------
 853 Node_Notes* Parse::make_node_notes(Node_Notes* caller_nn) {
 854   if (caller_nn == NULL)  return NULL;
 855   Node_Notes* nn = caller_nn->clone(C);
 856   JVMState* caller_jvms = nn->jvms();
 857   JVMState* jvms = new (C) JVMState(method(), caller_jvms);
 858   jvms->set_offsets(0);
 859   jvms->set_bci(_entry_bci);
 860   nn->set_jvms(jvms);
 861   return nn;
 862 }
 863 
 864 
 865 //--------------------------return_values--------------------------------------
 866 void Compile::return_values(JVMState* jvms) {
 867   GraphKit kit(jvms);
 868   Node* ret = new ReturnNode(TypeFunc::Parms,
 869                              kit.control(),
 870                              kit.i_o(),
 871                              kit.reset_memory(),
 872                              kit.frameptr(),
 873                              kit.returnadr());
 874   // Add zero or 1 return values
 875   int ret_size = tf()->range()->cnt() - TypeFunc::Parms;
 876   if (ret_size > 0) {
 877     kit.inc_sp(-ret_size);  // pop the return value(s)
 878     kit.sync_jvms();
 879     ret->add_req(kit.argument(0));
 880     // Note:  The second dummy edge is not needed by a ReturnNode.
 881   }
 882   // bind it to root
 883   root()->add_req(ret);
 884   record_for_igvn(ret);
 885   initial_gvn()->transform_no_reclaim(ret);
 886 }
 887 
 888 //------------------------rethrow_exceptions-----------------------------------
 889 // Bind all exception states in the list into a single RethrowNode.
 890 void Compile::rethrow_exceptions(JVMState* jvms) {
 891   GraphKit kit(jvms);
 892   if (!kit.has_exceptions())  return;  // nothing to generate
 893   // Load my combined exception state into the kit, with all phis transformed:
 894   SafePointNode* ex_map = kit.combine_and_pop_all_exception_states();
 895   Node* ex_oop = kit.use_exception_state(ex_map);
 896   RethrowNode* exit = new RethrowNode(kit.control(),
 897                                       kit.i_o(), kit.reset_memory(),
 898                                       kit.frameptr(), kit.returnadr(),
 899                                       // like a return but with exception input
 900                                       ex_oop);
 901   // bind to root
 902   root()->add_req(exit);
 903   record_for_igvn(exit);
 904   initial_gvn()->transform_no_reclaim(exit);
 905 }
 906 
 907 //---------------------------do_exceptions-------------------------------------
 908 // Process exceptions arising from the current bytecode.
 909 // Send caught exceptions to the proper handler within this method.
 910 // Unhandled exceptions feed into _exit.
 911 void Parse::do_exceptions() {
 912   if (!has_exceptions())  return;
 913 
 914   if (failing()) {
 915     // Pop them all off and throw them away.
 916     while (pop_exception_state() != NULL) ;
 917     return;
 918   }
 919 
 920   PreserveJVMState pjvms(this, false);
 921 
 922   SafePointNode* ex_map;
 923   while ((ex_map = pop_exception_state()) != NULL) {
 924     if (!method()->has_exception_handlers()) {
 925       // Common case:  Transfer control outward.
 926       // Doing it this early allows the exceptions to common up
 927       // even between adjacent method calls.
 928       throw_to_exit(ex_map);
 929     } else {
 930       // Have to look at the exception first.
 931       assert(stopped(), "catch_inline_exceptions trashes the map");
 932       catch_inline_exceptions(ex_map);
 933       stop_and_kill_map();      // we used up this exception state; kill it
 934     }
 935   }
 936 
 937   // We now return to our regularly scheduled program:
 938 }
 939 
 940 //---------------------------throw_to_exit-------------------------------------
 941 // Merge the given map into an exception exit from this method.
 942 // The exception exit will handle any unlocking of receiver.
 943 // The ex_oop must be saved within the ex_map, unlike merge_exception.
 944 void Parse::throw_to_exit(SafePointNode* ex_map) {
 945   // Pop the JVMS to (a copy of) the caller.
 946   GraphKit caller;
 947   caller.set_map_clone(_caller->map());
 948   caller.set_bci(_caller->bci());
 949   caller.set_sp(_caller->sp());
 950   // Copy out the standard machine state:
 951   for (uint i = 0; i < TypeFunc::Parms; i++) {
 952     caller.map()->set_req(i, ex_map->in(i));
 953   }
 954   if (ex_map->has_replaced_nodes()) {
 955     _replaced_nodes_for_exceptions = true;
 956   }
 957   caller.map()->transfer_replaced_nodes_from(ex_map, _new_idx);
 958   // ...and the exception:
 959   Node*          ex_oop        = saved_ex_oop(ex_map);
 960   SafePointNode* caller_ex_map = caller.make_exception_state(ex_oop);
 961   // Finally, collect the new exception state in my exits:
 962   _exits.add_exception_state(caller_ex_map);
 963 }
 964 
 965 //------------------------------do_exits---------------------------------------
 966 void Parse::do_exits() {
 967   set_parse_bci(InvocationEntryBci);
 968 
 969   // Now peephole on the return bits
 970   Node* region = _exits.control();
 971   _exits.set_control(gvn().transform(region));
 972 
 973   Node* iophi = _exits.i_o();
 974   _exits.set_i_o(gvn().transform(iophi));
 975 
 976   // Figure out if we need to emit the trailing barrier. The barrier is only
 977   // needed in the constructors, and only in three cases:
 978   //
 979   // 1. The constructor wrote a final. The effects of all initializations
 980   //    must be committed to memory before any code after the constructor
 981   //    publishes the reference to the newly constructed object. Rather
 982   //    than wait for the publication, we simply block the writes here.
 983   //    Rather than put a barrier on only those writes which are required
 984   //    to complete, we force all writes to complete.
 985   //
 986   // 2. On PPC64, also add MemBarRelease for constructors which write
 987   //    volatile fields. As support_IRIW_for_not_multiple_copy_atomic_cpu
 988   //    is set on PPC64, no sync instruction is issued after volatile
 989   //    stores. We want to guarantee the same behavior as on platforms
 990   //    with total store order, although this is not required by the Java
 991   //    memory model. So as with finals, we add a barrier here.
 992   //
 993   // 3. Experimental VM option is used to force the barrier if any field
 994   //    was written out in the constructor.
 995   //
 996   // "All bets are off" unless the first publication occurs after a
 997   // normal return from the constructor.  We do not attempt to detect
 998   // such unusual early publications.  But no barrier is needed on
 999   // exceptional returns, since they cannot publish normally.
1000   //
1001   if (method()->is_initializer() &&
1002         (wrote_final() ||
1003            PPC64_ONLY(wrote_volatile() ||)
1004            (AlwaysSafeConstructors && wrote_fields()))) {
1005     _exits.insert_mem_bar(Op_MemBarRelease, alloc_with_final());
1006 
1007     // If Memory barrier is created for final fields write
1008     // and allocation node does not escape the initialize method,
1009     // then barrier introduced by allocation node can be removed.
1010     if (DoEscapeAnalysis && alloc_with_final()) {
1011       AllocateNode *alloc = AllocateNode::Ideal_allocation(alloc_with_final(), &_gvn);
1012       alloc->compute_MemBar_redundancy(method());
1013     }
1014     if (PrintOpto && (Verbose || WizardMode)) {
1015       method()->print_name();
1016       tty->print_cr(" writes finals and needs a memory barrier");
1017     }
1018   }
1019 
1020   // Any method can write a @Stable field; insert memory barriers
1021   // after those also. Can't bind predecessor allocation node (if any)
1022   // with barrier because allocation doesn't always dominate
1023   // MemBarRelease.
1024   if (wrote_stable()) {
1025     _exits.insert_mem_bar(Op_MemBarRelease);
1026     if (PrintOpto && (Verbose || WizardMode)) {
1027       method()->print_name();
1028       tty->print_cr(" writes @Stable and needs a memory barrier");
1029     }
1030   }
1031 
1032   for (MergeMemStream mms(_exits.merged_memory()); mms.next_non_empty(); ) {
1033     // transform each slice of the original memphi:
1034     mms.set_memory(_gvn.transform(mms.memory()));
1035   }
1036   // Clean up input MergeMems created by transforming the slices
1037   _gvn.transform(_exits.merged_memory());
1038 
1039   if (tf()->range()->cnt() > TypeFunc::Parms) {
1040     const Type* ret_type = tf()->range()->field_at(TypeFunc::Parms);
1041     Node*       ret_phi  = _gvn.transform( _exits.argument(0) );
1042     if (!_exits.control()->is_top() && _gvn.type(ret_phi)->empty()) {
1043       // In case of concurrent class loading, the type we set for the
1044       // ret_phi in build_exits() may have been too optimistic and the
1045       // ret_phi may be top now.
1046       // Otherwise, we've encountered an error and have to mark the method as
1047       // not compilable. Just using an assertion instead would be dangerous
1048       // as this could lead to an infinite compile loop in non-debug builds.
1049       {
1050         if (C->env()->system_dictionary_modification_counter_changed()) {
1051           C->record_failure(C2Compiler::retry_class_loading_during_parsing());
1052         } else {
1053           C->record_method_not_compilable("Can't determine return type.");
1054         }
1055       }
1056       return;
1057     }
1058     if (ret_type->isa_int()) {
1059       BasicType ret_bt = method()->return_type()->basic_type();
1060       ret_phi = mask_int_value(ret_phi, ret_bt, &_gvn);
1061     }
1062     _exits.push_node(ret_type->basic_type(), ret_phi);
1063   }
1064 
1065   // Note:  Logic for creating and optimizing the ReturnNode is in Compile.
1066 
1067   // Unlock along the exceptional paths.
1068   // This is done late so that we can common up equivalent exceptions
1069   // (e.g., null checks) arising from multiple points within this method.
1070   // See GraphKit::add_exception_state, which performs the commoning.
1071   bool do_synch = method()->is_synchronized() && GenerateSynchronizationCode;
1072 
1073   // record exit from a method if compiled while Dtrace is turned on.
1074   if (do_synch || C->env()->dtrace_method_probes() || _replaced_nodes_for_exceptions) {
1075     // First move the exception list out of _exits:
1076     GraphKit kit(_exits.transfer_exceptions_into_jvms());
1077     SafePointNode* normal_map = kit.map();  // keep this guy safe
1078     // Now re-collect the exceptions into _exits:
1079     SafePointNode* ex_map;
1080     while ((ex_map = kit.pop_exception_state()) != NULL) {
1081       Node* ex_oop = kit.use_exception_state(ex_map);
1082       // Force the exiting JVM state to have this method at InvocationEntryBci.
1083       // The exiting JVM state is otherwise a copy of the calling JVMS.
1084       JVMState* caller = kit.jvms();
1085       JVMState* ex_jvms = caller->clone_shallow(C);
1086       ex_jvms->set_map(kit.clone_map());
1087       ex_jvms->map()->set_jvms(ex_jvms);
1088       ex_jvms->set_bci(   InvocationEntryBci);
1089       kit.set_jvms(ex_jvms);
1090       if (do_synch) {
1091         // Add on the synchronized-method box/object combo
1092         kit.map()->push_monitor(_synch_lock);
1093         // Unlock!
1094         kit.shared_unlock(_synch_lock->box_node(), _synch_lock->obj_node());
1095       }
1096       if (C->env()->dtrace_method_probes()) {
1097         kit.make_dtrace_method_exit(method());
1098       }
1099       if (_replaced_nodes_for_exceptions) {
1100         kit.map()->apply_replaced_nodes(_new_idx);
1101       }
1102       // Done with exception-path processing.
1103       ex_map = kit.make_exception_state(ex_oop);
1104       assert(ex_jvms->same_calls_as(ex_map->jvms()), "sanity");
1105       // Pop the last vestige of this method:
1106       ex_map->set_jvms(caller->clone_shallow(C));
1107       ex_map->jvms()->set_map(ex_map);
1108       _exits.push_exception_state(ex_map);
1109     }
1110     assert(_exits.map() == normal_map, "keep the same return state");
1111   }
1112 
1113   {
1114     // Capture very early exceptions (receiver null checks) from caller JVMS
1115     GraphKit caller(_caller);
1116     SafePointNode* ex_map;
1117     while ((ex_map = caller.pop_exception_state()) != NULL) {
1118       _exits.add_exception_state(ex_map);
1119     }
1120   }
1121   _exits.map()->apply_replaced_nodes(_new_idx);
1122 }
1123 
1124 //-----------------------------create_entry_map-------------------------------
1125 // Initialize our parser map to contain the types at method entry.
1126 // For OSR, the map contains a single RawPtr parameter.
1127 // Initial monitor locking for sync. methods is performed by do_method_entry.
1128 SafePointNode* Parse::create_entry_map() {
1129   // Check for really stupid bail-out cases.
1130   uint len = TypeFunc::Parms + method()->max_locals() + method()->max_stack();
1131   if (len >= 32760) {
1132     C->record_method_not_compilable("too many local variables");
1133     return NULL;
1134   }
1135 
1136   // clear current replaced nodes that are of no use from here on (map was cloned in build_exits).
1137   _caller->map()->delete_replaced_nodes();
1138 
1139   // If this is an inlined method, we may have to do a receiver null check.
1140   if (_caller->has_method() && is_normal_parse() && !method()->is_static()) {
1141     GraphKit kit(_caller);
1142     kit.null_check_receiver_before_call(method());
1143     _caller = kit.transfer_exceptions_into_jvms();
1144     if (kit.stopped()) {
1145       _exits.add_exception_states_from(_caller);
1146       _exits.set_jvms(_caller);
1147       return NULL;
1148     }
1149   }
1150 
1151   assert(method() != NULL, "parser must have a method");
1152 
1153   // Create an initial safepoint to hold JVM state during parsing
1154   JVMState* jvms = new (C) JVMState(method(), _caller->has_method() ? _caller : NULL);
1155   set_map(new SafePointNode(len, jvms));
1156   jvms->set_map(map());
1157   record_for_igvn(map());
1158   assert(jvms->endoff() == len, "correct jvms sizing");
1159 
1160   SafePointNode* inmap = _caller->map();
1161   assert(inmap != NULL, "must have inmap");
1162   // In case of null check on receiver above
1163   map()->transfer_replaced_nodes_from(inmap, _new_idx);
1164 
1165   uint i;
1166 
1167   // Pass thru the predefined input parameters.
1168   for (i = 0; i < TypeFunc::Parms; i++) {
1169     map()->init_req(i, inmap->in(i));
1170   }
1171 
1172   if (depth() == 1) {
1173     assert(map()->memory()->Opcode() == Op_Parm, "");
1174     // Insert the memory aliasing node
1175     set_all_memory(reset_memory());
1176   }
1177   assert(merged_memory(), "");
1178 
1179   // Now add the locals which are initially bound to arguments:
1180   uint arg_size = tf()->domain()->cnt();
1181   ensure_stack(arg_size - TypeFunc::Parms);  // OSR methods have funny args
1182   for (i = TypeFunc::Parms; i < arg_size; i++) {
1183     map()->init_req(i, inmap->argument(_caller, i - TypeFunc::Parms));
1184   }
1185 
1186   // Clear out the rest of the map (locals and stack)
1187   for (i = arg_size; i < len; i++) {
1188     map()->init_req(i, top());
1189   }
1190 
1191   SafePointNode* entry_map = stop();
1192   return entry_map;
1193 }
1194 
1195 //-----------------------------do_method_entry--------------------------------
1196 // Emit any code needed in the pseudo-block before BCI zero.
1197 // The main thing to do is lock the receiver of a synchronized method.
1198 void Parse::do_method_entry() {
1199   set_parse_bci(InvocationEntryBci); // Pseudo-BCP
1200   set_sp(0);                         // Java Stack Pointer
1201 
1202   NOT_PRODUCT( count_compiled_calls(true/*at_method_entry*/, false/*is_inline*/); )
1203 
1204   if (C->env()->dtrace_method_probes()) {
1205     make_dtrace_method_entry(method());
1206   }
1207 
1208   // If the method is synchronized, we need to construct a lock node, attach
1209   // it to the Start node, and pin it there.
1210   if (method()->is_synchronized()) {
1211     // Insert a FastLockNode right after the Start which takes as arguments
1212     // the current thread pointer, the "this" pointer & the address of the
1213     // stack slot pair used for the lock.  The "this" pointer is a projection
1214     // off the start node, but the locking spot has to be constructed by
1215     // creating a ConLNode of 0, and boxing it with a BoxLockNode.  The BoxLockNode
1216     // becomes the second argument to the FastLockNode call.  The
1217     // FastLockNode becomes the new control parent to pin it to the start.
1218 
1219     // Setup Object Pointer
1220     Node *lock_obj = NULL;
1221     if(method()->is_static()) {
1222       ciInstance* mirror = _method->holder()->java_mirror();
1223       const TypeInstPtr *t_lock = TypeInstPtr::make(mirror);
1224       lock_obj = makecon(t_lock);
1225     } else {                  // Else pass the "this" pointer,
1226       lock_obj = local(0);    // which is Parm0 from StartNode
1227     }
1228     // Clear out dead values from the debug info.
1229     kill_dead_locals();
1230     // Build the FastLockNode
1231     _synch_lock = shared_lock(lock_obj);
1232   }
1233 
1234   // Feed profiling data for parameters to the type system so it can
1235   // propagate it as speculative types
1236   record_profiled_parameters_for_speculation();
1237 
1238   if (depth() == 1) {
1239     increment_and_test_invocation_counter(Tier2CompileThreshold);
1240   }
1241 }
1242 
1243 //------------------------------init_blocks------------------------------------
1244 // Initialize our parser map to contain the types/monitors at method entry.
1245 void Parse::init_blocks() {
1246   // Create the blocks.
1247   _block_count = flow()->block_count();
1248   _blocks = NEW_RESOURCE_ARRAY(Block, _block_count);
1249 
1250   // Initialize the structs.
1251   for (int rpo = 0; rpo < block_count(); rpo++) {
1252     Block* block = rpo_at(rpo);
1253     new(block) Block(this, rpo);
1254   }
1255 
1256   // Collect predecessor and successor information.
1257   for (int rpo = 0; rpo < block_count(); rpo++) {
1258     Block* block = rpo_at(rpo);
1259     block->init_graph(this);
1260   }
1261 }
1262 
1263 //-------------------------------init_node-------------------------------------
1264 Parse::Block::Block(Parse* outer, int rpo) : _live_locals() {
1265   _flow = outer->flow()->rpo_at(rpo);
1266   _pred_count = 0;
1267   _preds_parsed = 0;
1268   _count = 0;
1269   _is_parsed = false;
1270   _is_handler = false;
1271   _has_merged_backedge = false;
1272   _start_map = NULL;
1273   _has_predicates = false;
1274   _num_successors = 0;
1275   _all_successors = 0;
1276   _successors = NULL;
1277   assert(pred_count() == 0 && preds_parsed() == 0, "sanity");
1278   assert(!(is_merged() || is_parsed() || is_handler() || has_merged_backedge()), "sanity");
1279   assert(_live_locals.size() == 0, "sanity");
1280 
1281   // entry point has additional predecessor
1282   if (flow()->is_start())  _pred_count++;
1283   assert(flow()->is_start() == (this == outer->start_block()), "");
1284 }
1285 
1286 //-------------------------------init_graph------------------------------------
1287 void Parse::Block::init_graph(Parse* outer) {
1288   // Create the successor list for this parser block.
1289   GrowableArray<ciTypeFlow::Block*>* tfs = flow()->successors();
1290   GrowableArray<ciTypeFlow::Block*>* tfe = flow()->exceptions();
1291   int ns = tfs->length();
1292   int ne = tfe->length();
1293   _num_successors = ns;
1294   _all_successors = ns+ne;
1295   _successors = (ns+ne == 0) ? NULL : NEW_RESOURCE_ARRAY(Block*, ns+ne);
1296   int p = 0;
1297   for (int i = 0; i < ns+ne; i++) {
1298     ciTypeFlow::Block* tf2 = (i < ns) ? tfs->at(i) : tfe->at(i-ns);
1299     Block* block2 = outer->rpo_at(tf2->rpo());
1300     _successors[i] = block2;
1301 
1302     // Accumulate pred info for the other block, too.
1303     if (i < ns) {
1304       block2->_pred_count++;
1305     } else {
1306       block2->_is_handler = true;
1307     }
1308 
1309     #ifdef ASSERT
1310     // A block's successors must be distinguishable by BCI.
1311     // That is, no bytecode is allowed to branch to two different
1312     // clones of the same code location.
1313     for (int j = 0; j < i; j++) {
1314       Block* block1 = _successors[j];
1315       if (block1 == block2)  continue;  // duplicates are OK
1316       assert(block1->start() != block2->start(), "successors have unique bcis");
1317     }
1318     #endif
1319   }
1320 
1321   // Note: We never call next_path_num along exception paths, so they
1322   // never get processed as "ready".  Also, the input phis of exception
1323   // handlers get specially processed, so that
1324 }
1325 
1326 //---------------------------successor_for_bci---------------------------------
1327 Parse::Block* Parse::Block::successor_for_bci(int bci) {
1328   for (int i = 0; i < all_successors(); i++) {
1329     Block* block2 = successor_at(i);
1330     if (block2->start() == bci)  return block2;
1331   }
1332   // We can actually reach here if ciTypeFlow traps out a block
1333   // due to an unloaded class, and concurrently with compilation the
1334   // class is then loaded, so that a later phase of the parser is
1335   // able to see more of the bytecode CFG.  Or, the flow pass and
1336   // the parser can have a minor difference of opinion about executability
1337   // of bytecodes.  For example, "obj.field = null" is executable even
1338   // if the field's type is an unloaded class; the flow pass used to
1339   // make a trap for such code.
1340   return NULL;
1341 }
1342 
1343 
1344 //-----------------------------stack_type_at-----------------------------------
1345 const Type* Parse::Block::stack_type_at(int i) const {
1346   return get_type(flow()->stack_type_at(i));
1347 }
1348 
1349 
1350 //-----------------------------local_type_at-----------------------------------
1351 const Type* Parse::Block::local_type_at(int i) const {
1352   // Make dead locals fall to bottom.
1353   if (_live_locals.size() == 0) {
1354     MethodLivenessResult live_locals = flow()->outer()->method()->liveness_at_bci(start());
1355     // This bitmap can be zero length if we saw a breakpoint.
1356     // In such cases, pretend they are all live.
1357     ((Block*)this)->_live_locals = live_locals;
1358   }
1359   if (_live_locals.size() > 0 && !_live_locals.at(i))
1360     return Type::BOTTOM;
1361 
1362   return get_type(flow()->local_type_at(i));
1363 }
1364 
1365 
1366 #ifndef PRODUCT
1367 
1368 //----------------------------name_for_bc--------------------------------------
1369 // helper method for BytecodeParseHistogram
1370 static const char* name_for_bc(int i) {
1371   return Bytecodes::is_defined(i) ? Bytecodes::name(Bytecodes::cast(i)) : "xxxunusedxxx";
1372 }
1373 
1374 //----------------------------BytecodeParseHistogram------------------------------------
1375 Parse::BytecodeParseHistogram::BytecodeParseHistogram(Parse *p, Compile *c) {
1376   _parser   = p;
1377   _compiler = c;
1378   if( ! _initialized ) { _initialized = true; reset(); }
1379 }
1380 
1381 //----------------------------current_count------------------------------------
1382 int Parse::BytecodeParseHistogram::current_count(BPHType bph_type) {
1383   switch( bph_type ) {
1384   case BPH_transforms: { return _parser->gvn().made_progress(); }
1385   case BPH_values:     { return _parser->gvn().made_new_values(); }
1386   default: { ShouldNotReachHere(); return 0; }
1387   }
1388 }
1389 
1390 //----------------------------initialized--------------------------------------
1391 bool Parse::BytecodeParseHistogram::initialized() { return _initialized; }
1392 
1393 //----------------------------reset--------------------------------------------
1394 void Parse::BytecodeParseHistogram::reset() {
1395   int i = Bytecodes::number_of_codes;
1396   while (i-- > 0) { _bytecodes_parsed[i] = 0; _nodes_constructed[i] = 0; _nodes_transformed[i] = 0; _new_values[i] = 0; }
1397 }
1398 
1399 //----------------------------set_initial_state--------------------------------
1400 // Record info when starting to parse one bytecode
1401 void Parse::BytecodeParseHistogram::set_initial_state( Bytecodes::Code bc ) {
1402   if( PrintParseStatistics && !_parser->is_osr_parse() ) {
1403     _initial_bytecode    = bc;
1404     _initial_node_count  = _compiler->unique();
1405     _initial_transforms  = current_count(BPH_transforms);
1406     _initial_values      = current_count(BPH_values);
1407   }
1408 }
1409 
1410 //----------------------------record_change--------------------------------
1411 // Record results of parsing one bytecode
1412 void Parse::BytecodeParseHistogram::record_change() {
1413   if( PrintParseStatistics && !_parser->is_osr_parse() ) {
1414     ++_bytecodes_parsed[_initial_bytecode];
1415     _nodes_constructed [_initial_bytecode] += (_compiler->unique() - _initial_node_count);
1416     _nodes_transformed [_initial_bytecode] += (current_count(BPH_transforms) - _initial_transforms);
1417     _new_values        [_initial_bytecode] += (current_count(BPH_values)     - _initial_values);
1418   }
1419 }
1420 
1421 
1422 //----------------------------print--------------------------------------------
1423 void Parse::BytecodeParseHistogram::print(float cutoff) {
1424   ResourceMark rm;
1425   // print profile
1426   int total  = 0;
1427   int i      = 0;
1428   for( i = 0; i < Bytecodes::number_of_codes; ++i ) { total += _bytecodes_parsed[i]; }
1429   int abs_sum = 0;
1430   tty->cr();   //0123456789012345678901234567890123456789012345678901234567890123456789
1431   tty->print_cr("Histogram of %d parsed bytecodes:", total);
1432   if( total == 0 ) { return; }
1433   tty->cr();
1434   tty->print_cr("absolute:  count of compiled bytecodes of this type");
1435   tty->print_cr("relative:  percentage contribution to compiled nodes");
1436   tty->print_cr("nodes   :  Average number of nodes constructed per bytecode");
1437   tty->print_cr("rnodes  :  Significance towards total nodes constructed, (nodes*relative)");
1438   tty->print_cr("transforms: Average amount of tranform progress per bytecode compiled");
1439   tty->print_cr("values  :  Average number of node values improved per bytecode");
1440   tty->print_cr("name    :  Bytecode name");
1441   tty->cr();
1442   tty->print_cr("  absolute  relative   nodes  rnodes  transforms  values   name");
1443   tty->print_cr("----------------------------------------------------------------------");
1444   while (--i > 0) {
1445     int       abs = _bytecodes_parsed[i];
1446     float     rel = abs * 100.0F / total;
1447     float   nodes = _bytecodes_parsed[i] == 0 ? 0 : (1.0F * _nodes_constructed[i])/_bytecodes_parsed[i];
1448     float  rnodes = _bytecodes_parsed[i] == 0 ? 0 :  rel * nodes;
1449     float  xforms = _bytecodes_parsed[i] == 0 ? 0 : (1.0F * _nodes_transformed[i])/_bytecodes_parsed[i];
1450     float  values = _bytecodes_parsed[i] == 0 ? 0 : (1.0F * _new_values       [i])/_bytecodes_parsed[i];
1451     if (cutoff <= rel) {
1452       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));
1453       abs_sum += abs;
1454     }
1455   }
1456   tty->print_cr("----------------------------------------------------------------------");
1457   float rel_sum = abs_sum * 100.0F / total;
1458   tty->print_cr("%10d  %7.2f%%    (cutoff = %.2f%%)", abs_sum, rel_sum, cutoff);
1459   tty->print_cr("----------------------------------------------------------------------");
1460   tty->cr();
1461 }
1462 #endif
1463 
1464 //----------------------------load_state_from----------------------------------
1465 // Load block/map/sp.  But not do not touch iter/bci.
1466 void Parse::load_state_from(Block* block) {
1467   set_block(block);
1468   // load the block's JVM state:
1469   set_map(block->start_map());
1470   set_sp( block->start_sp());
1471 }
1472 
1473 
1474 //-----------------------------record_state------------------------------------
1475 void Parse::Block::record_state(Parse* p) {
1476   assert(!is_merged(), "can only record state once, on 1st inflow");
1477   assert(start_sp() == p->sp(), "stack pointer must agree with ciTypeFlow");
1478   set_start_map(p->stop());
1479 }
1480 
1481 
1482 //------------------------------do_one_block-----------------------------------
1483 void Parse::do_one_block() {
1484   if (TraceOptoParse) {
1485     Block *b = block();
1486     int ns = b->num_successors();
1487     int nt = b->all_successors();
1488 
1489     tty->print("Parsing block #%d at bci [%d,%d), successors: ",
1490                   block()->rpo(), block()->start(), block()->limit());
1491     for (int i = 0; i < nt; i++) {
1492       tty->print((( i < ns) ? " %d" : " %d(e)"), b->successor_at(i)->rpo());
1493     }
1494     if (b->is_loop_head()) tty->print("  lphd");
1495     tty->cr();
1496   }
1497 
1498   assert(block()->is_merged(), "must be merged before being parsed");
1499   block()->mark_parsed();
1500 
1501   // Set iterator to start of block.
1502   iter().reset_to_bci(block()->start());
1503 
1504   CompileLog* log = C->log();
1505 
1506   // Parse bytecodes
1507   while (!stopped() && !failing()) {
1508     iter().next();
1509 
1510     // Learn the current bci from the iterator:
1511     set_parse_bci(iter().cur_bci());
1512 
1513     if (bci() == block()->limit()) {
1514       // Do not walk into the next block until directed by do_all_blocks.
1515       merge(bci());
1516       break;
1517     }
1518     assert(bci() < block()->limit(), "bci still in block");
1519 
1520     if (log != NULL) {
1521       // Output an optional context marker, to help place actions
1522       // that occur during parsing of this BC.  If there is no log
1523       // output until the next context string, this context string
1524       // will be silently ignored.
1525       log->set_context("bc code='%d' bci='%d'", (int)bc(), bci());
1526     }
1527 
1528     if (block()->has_trap_at(bci())) {
1529       // We must respect the flow pass's traps, because it will refuse
1530       // to produce successors for trapping blocks.
1531       int trap_index = block()->flow()->trap_index();
1532       assert(trap_index != 0, "trap index must be valid");
1533       uncommon_trap(trap_index);
1534       break;
1535     }
1536 
1537     NOT_PRODUCT( parse_histogram()->set_initial_state(bc()); );
1538 
1539 #ifdef ASSERT
1540     int pre_bc_sp = sp();
1541     int inputs, depth;
1542     bool have_se = !stopped() && compute_stack_effects(inputs, depth);
1543     assert(!have_se || pre_bc_sp >= inputs, "have enough stack to execute this BC: pre_bc_sp=%d, inputs=%d", pre_bc_sp, inputs);
1544 #endif //ASSERT
1545 
1546     do_one_bytecode();
1547 
1548     assert(!have_se || stopped() || failing() || (sp() - pre_bc_sp) == depth,
1549            "incorrect depth prediction: sp=%d, pre_bc_sp=%d, depth=%d", sp(), pre_bc_sp, depth);
1550 
1551     do_exceptions();
1552 
1553     NOT_PRODUCT( parse_histogram()->record_change(); );
1554 
1555     if (log != NULL)
1556       log->clear_context();  // skip marker if nothing was printed
1557 
1558     // Fall into next bytecode.  Each bytecode normally has 1 sequential
1559     // successor which is typically made ready by visiting this bytecode.
1560     // If the successor has several predecessors, then it is a merge
1561     // point, starts a new basic block, and is handled like other basic blocks.
1562   }
1563 }
1564 
1565 
1566 //------------------------------merge------------------------------------------
1567 void Parse::set_parse_bci(int bci) {
1568   set_bci(bci);
1569   Node_Notes* nn = C->default_node_notes();
1570   if (nn == NULL)  return;
1571 
1572   // Collect debug info for inlined calls unless -XX:-DebugInlinedCalls.
1573   if (!DebugInlinedCalls && depth() > 1) {
1574     return;
1575   }
1576 
1577   // Update the JVMS annotation, if present.
1578   JVMState* jvms = nn->jvms();
1579   if (jvms != NULL && jvms->bci() != bci) {
1580     // Update the JVMS.
1581     jvms = jvms->clone_shallow(C);
1582     jvms->set_bci(bci);
1583     nn->set_jvms(jvms);
1584   }
1585 }
1586 
1587 //------------------------------merge------------------------------------------
1588 // Merge the current mapping into the basic block starting at bci
1589 void Parse::merge(int target_bci) {
1590   Block* target = successor_for_bci(target_bci);
1591   if (target == NULL) { handle_missing_successor(target_bci); return; }
1592   assert(!target->is_ready(), "our arrival must be expected");
1593   int pnum = target->next_path_num();
1594   merge_common(target, pnum);
1595 }
1596 
1597 //-------------------------merge_new_path--------------------------------------
1598 // Merge the current mapping into the basic block, using a new path
1599 void Parse::merge_new_path(int target_bci) {
1600   Block* target = successor_for_bci(target_bci);
1601   if (target == NULL) { handle_missing_successor(target_bci); return; }
1602   assert(!target->is_ready(), "new path into frozen graph");
1603   int pnum = target->add_new_path();
1604   merge_common(target, pnum);
1605 }
1606 
1607 //-------------------------merge_exception-------------------------------------
1608 // Merge the current mapping into the basic block starting at bci
1609 // The ex_oop must be pushed on the stack, unlike throw_to_exit.
1610 void Parse::merge_exception(int target_bci) {
1611   assert(sp() == 1, "must have only the throw exception on the stack");
1612   Block* target = successor_for_bci(target_bci);
1613   if (target == NULL) { handle_missing_successor(target_bci); return; }
1614   assert(target->is_handler(), "exceptions are handled by special blocks");
1615   int pnum = target->add_new_path();
1616   merge_common(target, pnum);
1617 }
1618 
1619 //--------------------handle_missing_successor---------------------------------
1620 void Parse::handle_missing_successor(int target_bci) {
1621 #ifndef PRODUCT
1622   Block* b = block();
1623   int trap_bci = b->flow()->has_trap()? b->flow()->trap_bci(): -1;
1624   tty->print_cr("### Missing successor at bci:%d for block #%d (trap_bci:%d)", target_bci, b->rpo(), trap_bci);
1625 #endif
1626   ShouldNotReachHere();
1627 }
1628 
1629 //--------------------------merge_common---------------------------------------
1630 void Parse::merge_common(Parse::Block* target, int pnum) {
1631   if (TraceOptoParse) {
1632     tty->print("Merging state at block #%d bci:%d", target->rpo(), target->start());
1633   }
1634 
1635   // Zap extra stack slots to top
1636   assert(sp() == target->start_sp(), "");
1637   clean_stack(sp());
1638 
1639   if (!target->is_merged()) {   // No prior mapping at this bci
1640     if (TraceOptoParse) { tty->print(" with empty state");  }
1641 
1642     // If this path is dead, do not bother capturing it as a merge.
1643     // It is "as if" we had 1 fewer predecessors from the beginning.
1644     if (stopped()) {
1645       if (TraceOptoParse)  tty->print_cr(", but path is dead and doesn't count");
1646       return;
1647     }
1648 
1649     // Make a region if we know there are multiple or unpredictable inputs.
1650     // (Also, if this is a plain fall-through, we might see another region,
1651     // which must not be allowed into this block's map.)
1652     if (pnum > PhiNode::Input         // Known multiple inputs.
1653         || target->is_handler()       // These have unpredictable inputs.
1654         || target->is_loop_head()     // Known multiple inputs
1655         || control()->is_Region()) {  // We must hide this guy.
1656 
1657       int current_bci = bci();
1658       set_parse_bci(target->start()); // Set target bci
1659       if (target->is_SEL_head()) {
1660         DEBUG_ONLY( target->mark_merged_backedge(block()); )
1661         if (target->start() == 0) {
1662           // Add loop predicate for the special case when
1663           // there are backbranches to the method entry.
1664           add_predicate();
1665         }
1666       }
1667       // Add a Region to start the new basic block.  Phis will be added
1668       // later lazily.
1669       int edges = target->pred_count();
1670       if (edges < pnum)  edges = pnum;  // might be a new path!
1671       RegionNode *r = new RegionNode(edges+1);
1672       gvn().set_type(r, Type::CONTROL);
1673       record_for_igvn(r);
1674       // zap all inputs to NULL for debugging (done in Node(uint) constructor)
1675       // for (int j = 1; j < edges+1; j++) { r->init_req(j, NULL); }
1676       r->init_req(pnum, control());
1677       set_control(r);
1678       set_parse_bci(current_bci); // Restore bci
1679     }
1680 
1681     // Convert the existing Parser mapping into a mapping at this bci.
1682     store_state_to(target);
1683     assert(target->is_merged(), "do not come here twice");
1684 
1685   } else {                      // Prior mapping at this bci
1686     if (TraceOptoParse) {  tty->print(" with previous state"); }
1687 #ifdef ASSERT
1688     if (target->is_SEL_head()) {
1689       target->mark_merged_backedge(block());
1690     }
1691 #endif
1692     // We must not manufacture more phis if the target is already parsed.
1693     bool nophi = target->is_parsed();
1694 
1695     SafePointNode* newin = map();// Hang on to incoming mapping
1696     Block* save_block = block(); // Hang on to incoming block;
1697     load_state_from(target);    // Get prior mapping
1698 
1699     assert(newin->jvms()->locoff() == jvms()->locoff(), "JVMS layouts agree");
1700     assert(newin->jvms()->stkoff() == jvms()->stkoff(), "JVMS layouts agree");
1701     assert(newin->jvms()->monoff() == jvms()->monoff(), "JVMS layouts agree");
1702     assert(newin->jvms()->endoff() == jvms()->endoff(), "JVMS layouts agree");
1703 
1704     // Iterate over my current mapping and the old mapping.
1705     // Where different, insert Phi functions.
1706     // Use any existing Phi functions.
1707     assert(control()->is_Region(), "must be merging to a region");
1708     RegionNode* r = control()->as_Region();
1709 
1710     // Compute where to merge into
1711     // Merge incoming control path
1712     r->init_req(pnum, newin->control());
1713 
1714     if (pnum == 1) {            // Last merge for this Region?
1715       if (!block()->flow()->is_irreducible_entry()) {
1716         Node* result = _gvn.transform_no_reclaim(r);
1717         if (r != result && TraceOptoParse) {
1718           tty->print_cr("Block #%d replace %d with %d", block()->rpo(), r->_idx, result->_idx);
1719         }
1720       }
1721       record_for_igvn(r);
1722     }
1723 
1724     // Update all the non-control inputs to map:
1725     assert(TypeFunc::Parms == newin->jvms()->locoff(), "parser map should contain only youngest jvms");
1726     bool check_elide_phi = target->is_SEL_backedge(save_block);
1727     for (uint j = 1; j < newin->req(); j++) {
1728       Node* m = map()->in(j);   // Current state of target.
1729       Node* n = newin->in(j);   // Incoming change to target state.
1730       PhiNode* phi;
1731       if (m->is_Phi() && m->as_Phi()->region() == r)
1732         phi = m->as_Phi();
1733       else
1734         phi = NULL;
1735       if (m != n) {             // Different; must merge
1736         switch (j) {
1737         // Frame pointer and Return Address never changes
1738         case TypeFunc::FramePtr:// Drop m, use the original value
1739         case TypeFunc::ReturnAdr:
1740           break;
1741         case TypeFunc::Memory:  // Merge inputs to the MergeMem node
1742           assert(phi == NULL, "the merge contains phis, not vice versa");
1743           merge_memory_edges(n->as_MergeMem(), pnum, nophi);
1744           continue;
1745         default:                // All normal stuff
1746           if (phi == NULL) {
1747             const JVMState* jvms = map()->jvms();
1748             if (EliminateNestedLocks &&
1749                 jvms->is_mon(j) && jvms->is_monitor_box(j)) {
1750               // BoxLock nodes are not commoning.
1751               // Use old BoxLock node as merged box.
1752               assert(newin->jvms()->is_monitor_box(j), "sanity");
1753               // This assert also tests that nodes are BoxLock.
1754               assert(BoxLockNode::same_slot(n, m), "sanity");
1755               C->gvn_replace_by(n, m);
1756             } else if (!check_elide_phi || !target->can_elide_SEL_phi(j)) {
1757               phi = ensure_phi(j, nophi);
1758             }
1759           }
1760           break;
1761         }
1762       }
1763       // At this point, n might be top if:
1764       //  - there is no phi (because TypeFlow detected a conflict), or
1765       //  - the corresponding control edges is top (a dead incoming path)
1766       // It is a bug if we create a phi which sees a garbage value on a live path.
1767 
1768       if (phi != NULL) {
1769         assert(n != top() || r->in(pnum) == top(), "live value must not be garbage");
1770         assert(phi->region() == r, "");
1771         phi->set_req(pnum, n);  // Then add 'n' to the merge
1772         if (pnum == PhiNode::Input) {
1773           // Last merge for this Phi.
1774           // So far, Phis have had a reasonable type from ciTypeFlow.
1775           // Now _gvn will join that with the meet of current inputs.
1776           // BOTTOM is never permissible here, 'cause pessimistically
1777           // Phis of pointers cannot lose the basic pointer type.
1778           debug_only(const Type* bt1 = phi->bottom_type());
1779           assert(bt1 != Type::BOTTOM, "should not be building conflict phis");
1780           map()->set_req(j, _gvn.transform_no_reclaim(phi));
1781           debug_only(const Type* bt2 = phi->bottom_type());
1782           assert(bt2->higher_equal_speculative(bt1), "must be consistent with type-flow");
1783           record_for_igvn(phi);
1784         }
1785       }
1786     } // End of for all values to be merged
1787 
1788     if (pnum == PhiNode::Input &&
1789         !r->in(0)) {         // The occasional useless Region
1790       assert(control() == r, "");
1791       set_control(r->nonnull_req());
1792     }
1793 
1794     map()->merge_replaced_nodes_with(newin);
1795 
1796     // newin has been subsumed into the lazy merge, and is now dead.
1797     set_block(save_block);
1798 
1799     stop();                     // done with this guy, for now
1800   }
1801 
1802   if (TraceOptoParse) {
1803     tty->print_cr(" on path %d", pnum);
1804   }
1805 
1806   // Done with this parser state.
1807   assert(stopped(), "");
1808 }
1809 
1810 
1811 //--------------------------merge_memory_edges---------------------------------
1812 void Parse::merge_memory_edges(MergeMemNode* n, int pnum, bool nophi) {
1813   // (nophi means we must not create phis, because we already parsed here)
1814   assert(n != NULL, "");
1815   // Merge the inputs to the MergeMems
1816   MergeMemNode* m = merged_memory();
1817 
1818   assert(control()->is_Region(), "must be merging to a region");
1819   RegionNode* r = control()->as_Region();
1820 
1821   PhiNode* base = NULL;
1822   MergeMemNode* remerge = NULL;
1823   for (MergeMemStream mms(m, n); mms.next_non_empty2(); ) {
1824     Node *p = mms.force_memory();
1825     Node *q = mms.memory2();
1826     if (mms.is_empty() && nophi) {
1827       // Trouble:  No new splits allowed after a loop body is parsed.
1828       // Instead, wire the new split into a MergeMem on the backedge.
1829       // The optimizer will sort it out, slicing the phi.
1830       if (remerge == NULL) {
1831         guarantee(base != NULL, "");
1832         assert(base->in(0) != NULL, "should not be xformed away");
1833         remerge = MergeMemNode::make(base->in(pnum));
1834         gvn().set_type(remerge, Type::MEMORY);
1835         base->set_req(pnum, remerge);
1836       }
1837       remerge->set_memory_at(mms.alias_idx(), q);
1838       continue;
1839     }
1840     assert(!q->is_MergeMem(), "");
1841     PhiNode* phi;
1842     if (p != q) {
1843       phi = ensure_memory_phi(mms.alias_idx(), nophi);
1844     } else {
1845       if (p->is_Phi() && p->as_Phi()->region() == r)
1846         phi = p->as_Phi();
1847       else
1848         phi = NULL;
1849     }
1850     // Insert q into local phi
1851     if (phi != NULL) {
1852       assert(phi->region() == r, "");
1853       p = phi;
1854       phi->set_req(pnum, q);
1855       if (mms.at_base_memory()) {
1856         base = phi;  // delay transforming it
1857       } else if (pnum == 1) {
1858         record_for_igvn(phi);
1859         p = _gvn.transform_no_reclaim(phi);
1860       }
1861       mms.set_memory(p);// store back through the iterator
1862     }
1863   }
1864   // Transform base last, in case we must fiddle with remerging.
1865   if (base != NULL && pnum == 1) {
1866     record_for_igvn(base);
1867     m->set_base_memory( _gvn.transform_no_reclaim(base) );
1868   }
1869 }
1870 
1871 
1872 //------------------------ensure_phis_everywhere-------------------------------
1873 void Parse::ensure_phis_everywhere() {
1874   ensure_phi(TypeFunc::I_O);
1875 
1876   // Ensure a phi on all currently known memories.
1877   for (MergeMemStream mms(merged_memory()); mms.next_non_empty(); ) {
1878     ensure_memory_phi(mms.alias_idx());
1879     debug_only(mms.set_memory());  // keep the iterator happy
1880   }
1881 
1882   // Note:  This is our only chance to create phis for memory slices.
1883   // If we miss a slice that crops up later, it will have to be
1884   // merged into the base-memory phi that we are building here.
1885   // Later, the optimizer will comb out the knot, and build separate
1886   // phi-loops for each memory slice that matters.
1887 
1888   // Monitors must nest nicely and not get confused amongst themselves.
1889   // Phi-ify everything up to the monitors, though.
1890   uint monoff = map()->jvms()->monoff();
1891   uint nof_monitors = map()->jvms()->nof_monitors();
1892 
1893   assert(TypeFunc::Parms == map()->jvms()->locoff(), "parser map should contain only youngest jvms");
1894   bool check_elide_phi = block()->is_SEL_head();
1895   for (uint i = TypeFunc::Parms; i < monoff; i++) {
1896     if (!check_elide_phi || !block()->can_elide_SEL_phi(i)) {
1897       ensure_phi(i);
1898     }
1899   }
1900 
1901   // Even monitors need Phis, though they are well-structured.
1902   // This is true for OSR methods, and also for the rare cases where
1903   // a monitor object is the subject of a replace_in_map operation.
1904   // See bugs 4426707 and 5043395.
1905   for (uint m = 0; m < nof_monitors; m++) {
1906     ensure_phi(map()->jvms()->monitor_obj_offset(m));
1907   }
1908 }
1909 
1910 
1911 //-----------------------------add_new_path------------------------------------
1912 // Add a previously unaccounted predecessor to this block.
1913 int Parse::Block::add_new_path() {
1914   // If there is no map, return the lowest unused path number.
1915   if (!is_merged())  return pred_count()+1;  // there will be a map shortly
1916 
1917   SafePointNode* map = start_map();
1918   if (!map->control()->is_Region())
1919     return pred_count()+1;  // there may be a region some day
1920   RegionNode* r = map->control()->as_Region();
1921 
1922   // Add new path to the region.
1923   uint pnum = r->req();
1924   r->add_req(NULL);
1925 
1926   for (uint i = 1; i < map->req(); i++) {
1927     Node* n = map->in(i);
1928     if (i == TypeFunc::Memory) {
1929       // Ensure a phi on all currently known memories.
1930       for (MergeMemStream mms(n->as_MergeMem()); mms.next_non_empty(); ) {
1931         Node* phi = mms.memory();
1932         if (phi->is_Phi() && phi->as_Phi()->region() == r) {
1933           assert(phi->req() == pnum, "must be same size as region");
1934           phi->add_req(NULL);
1935         }
1936       }
1937     } else {
1938       if (n->is_Phi() && n->as_Phi()->region() == r) {
1939         assert(n->req() == pnum, "must be same size as region");
1940         n->add_req(NULL);
1941       }
1942     }
1943   }
1944 
1945   return pnum;
1946 }
1947 
1948 //------------------------------ensure_phi-------------------------------------
1949 // Turn the idx'th entry of the current map into a Phi
1950 PhiNode *Parse::ensure_phi(int idx, bool nocreate) {
1951   SafePointNode* map = this->map();
1952   Node* region = map->control();
1953   assert(region->is_Region(), "");
1954 
1955   Node* o = map->in(idx);
1956   assert(o != NULL, "");
1957 
1958   if (o == top())  return NULL; // TOP always merges into TOP
1959 
1960   if (o->is_Phi() && o->as_Phi()->region() == region) {
1961     return o->as_Phi();
1962   }
1963 
1964   // Now use a Phi here for merging
1965   assert(!nocreate, "Cannot build a phi for a block already parsed.");
1966   const JVMState* jvms = map->jvms();
1967   const Type* t = NULL;
1968   if (jvms->is_loc(idx)) {
1969     t = block()->local_type_at(idx - jvms->locoff());
1970   } else if (jvms->is_stk(idx)) {
1971     t = block()->stack_type_at(idx - jvms->stkoff());
1972   } else if (jvms->is_mon(idx)) {
1973     assert(!jvms->is_monitor_box(idx), "no phis for boxes");
1974     t = TypeInstPtr::BOTTOM; // this is sufficient for a lock object
1975   } else if ((uint)idx < TypeFunc::Parms) {
1976     t = o->bottom_type();  // Type::RETURN_ADDRESS or such-like.
1977   } else {
1978     assert(false, "no type information for this phi");
1979   }
1980 
1981   // If the type falls to bottom, then this must be a local that
1982   // is mixing ints and oops or some such.  Forcing it to top
1983   // makes it go dead.
1984   if (t == Type::BOTTOM) {
1985     map->set_req(idx, top());
1986     return NULL;
1987   }
1988 
1989   // Do not create phis for top either.
1990   // A top on a non-null control flow must be an unused even after the.phi.
1991   if (t == Type::TOP || t == Type::HALF) {
1992     map->set_req(idx, top());
1993     return NULL;
1994   }
1995 
1996   PhiNode* phi = PhiNode::make(region, o, t);
1997   gvn().set_type(phi, t);
1998   if (C->do_escape_analysis()) record_for_igvn(phi);
1999   map->set_req(idx, phi);
2000   return phi;
2001 }
2002 
2003 //--------------------------ensure_memory_phi----------------------------------
2004 // Turn the idx'th slice of the current memory into a Phi
2005 PhiNode *Parse::ensure_memory_phi(int idx, bool nocreate) {
2006   MergeMemNode* mem = merged_memory();
2007   Node* region = control();
2008   assert(region->is_Region(), "");
2009 
2010   Node *o = (idx == Compile::AliasIdxBot)? mem->base_memory(): mem->memory_at(idx);
2011   assert(o != NULL && o != top(), "");
2012 
2013   PhiNode* phi;
2014   if (o->is_Phi() && o->as_Phi()->region() == region) {
2015     phi = o->as_Phi();
2016     if (phi == mem->base_memory() && idx >= Compile::AliasIdxRaw) {
2017       // clone the shared base memory phi to make a new memory split
2018       assert(!nocreate, "Cannot build a phi for a block already parsed.");
2019       const Type* t = phi->bottom_type();
2020       const TypePtr* adr_type = C->get_adr_type(idx);
2021       phi = phi->slice_memory(adr_type);
2022       gvn().set_type(phi, t);
2023     }
2024     return phi;
2025   }
2026 
2027   // Now use a Phi here for merging
2028   assert(!nocreate, "Cannot build a phi for a block already parsed.");
2029   const Type* t = o->bottom_type();
2030   const TypePtr* adr_type = C->get_adr_type(idx);
2031   phi = PhiNode::make(region, o, t, adr_type);
2032   gvn().set_type(phi, t);
2033   if (idx == Compile::AliasIdxBot)
2034     mem->set_base_memory(phi);
2035   else
2036     mem->set_memory_at(idx, phi);
2037   return phi;
2038 }
2039 
2040 //------------------------------call_register_finalizer-----------------------
2041 // Check the klass of the receiver and call register_finalizer if the
2042 // class need finalization.
2043 void Parse::call_register_finalizer() {
2044   Node* receiver = local(0);
2045   assert(receiver != NULL && receiver->bottom_type()->isa_instptr() != NULL,
2046          "must have non-null instance type");
2047 
2048   const TypeInstPtr *tinst = receiver->bottom_type()->isa_instptr();
2049   if (tinst != NULL && tinst->klass()->is_loaded() && !tinst->klass_is_exact()) {
2050     // The type isn't known exactly so see if CHA tells us anything.
2051     ciInstanceKlass* ik = tinst->klass()->as_instance_klass();
2052     if (!Dependencies::has_finalizable_subclass(ik)) {
2053       // No finalizable subclasses so skip the dynamic check.
2054       C->dependencies()->assert_has_no_finalizable_subclasses(ik);
2055       return;
2056     }
2057   }
2058 
2059   // Insert a dynamic test for whether the instance needs
2060   // finalization.  In general this will fold up since the concrete
2061   // class is often visible so the access flags are constant.
2062   Node* klass_addr = basic_plus_adr( receiver, receiver, oopDesc::klass_offset_in_bytes() );
2063   Node* klass = _gvn.transform(LoadKlassNode::make(_gvn, NULL, immutable_memory(), klass_addr, TypeInstPtr::KLASS));
2064 
2065   Node* access_flags_addr = basic_plus_adr(klass, klass, in_bytes(Klass::access_flags_offset()));
2066   Node* access_flags = make_load(NULL, access_flags_addr, TypeInt::INT, T_INT, MemNode::unordered);
2067 
2068   Node* mask  = _gvn.transform(new AndINode(access_flags, intcon(JVM_ACC_HAS_FINALIZER)));
2069   Node* check = _gvn.transform(new CmpINode(mask, intcon(0)));
2070   Node* test  = _gvn.transform(new BoolNode(check, BoolTest::ne));
2071 
2072   IfNode* iff = create_and_map_if(control(), test, PROB_MAX, COUNT_UNKNOWN);
2073 
2074   RegionNode* result_rgn = new RegionNode(3);
2075   record_for_igvn(result_rgn);
2076 
2077   Node *skip_register = _gvn.transform(new IfFalseNode(iff));
2078   result_rgn->init_req(1, skip_register);
2079 
2080   Node *needs_register = _gvn.transform(new IfTrueNode(iff));
2081   set_control(needs_register);
2082   if (stopped()) {
2083     // There is no slow path.
2084     result_rgn->init_req(2, top());
2085   } else {
2086     Node *call = make_runtime_call(RC_NO_LEAF,
2087                                    OptoRuntime::register_finalizer_Type(),
2088                                    OptoRuntime::register_finalizer_Java(),
2089                                    NULL, TypePtr::BOTTOM,
2090                                    receiver);
2091     make_slow_call_ex(call, env()->Throwable_klass(), true);
2092 
2093     Node* fast_io  = call->in(TypeFunc::I_O);
2094     Node* fast_mem = call->in(TypeFunc::Memory);
2095     // These two phis are pre-filled with copies of of the fast IO and Memory
2096     Node* io_phi   = PhiNode::make(result_rgn, fast_io,  Type::ABIO);
2097     Node* mem_phi  = PhiNode::make(result_rgn, fast_mem, Type::MEMORY, TypePtr::BOTTOM);
2098 
2099     result_rgn->init_req(2, control());
2100     io_phi    ->init_req(2, i_o());
2101     mem_phi   ->init_req(2, reset_memory());
2102 
2103     set_all_memory( _gvn.transform(mem_phi) );
2104     set_i_o(        _gvn.transform(io_phi) );
2105   }
2106 
2107   set_control( _gvn.transform(result_rgn) );
2108 }
2109 
2110 // Add check to deoptimize once holder klass is fully initialized.
2111 void Parse::clinit_deopt() {
2112   assert(C->has_method(), "only for normal compilations");
2113   assert(depth() == 1, "only for main compiled method");
2114   assert(is_normal_parse(), "no barrier needed on osr entry");
2115   assert(method()->needs_clinit_barrier(), "barrier not needed");
2116   assert(method()->holder()->is_being_initialized(), "barrier not needed");
2117 
2118   set_parse_bci(0);
2119 
2120   Node* holder = makecon(TypeKlassPtr::make(method()->holder()));
2121   int init_state_off = in_bytes(InstanceKlass::init_state_offset());
2122   const Type* t = TypeKlassPtr::make(method()->holder(), init_state_off);
2123   Node* adr = basic_plus_adr(top(), holder, init_state_off);
2124   Node* init_state = make_load(control(), adr, TypeInt::BYTE, T_BYTE, MemNode::unordered);
2125 
2126   Node* fully_initialized_state = makecon(TypeInt::make(InstanceKlass::fully_initialized));
2127 
2128   Node* chk = gvn().transform(new CmpINode(init_state, fully_initialized_state));
2129   Node* tst = gvn().transform(new BoolNode(chk, BoolTest::ne));
2130 
2131   { BuildCutout unless(this, tst, PROB_MAX);
2132     uncommon_trap(Deoptimization::Reason_initialized, Deoptimization::Action_reinterpret);
2133   }
2134 }
2135 
2136 // Add check to deoptimize if RTM state is not ProfileRTM
2137 void Parse::rtm_deopt() {
2138 #if INCLUDE_RTM_OPT
2139   if (C->profile_rtm()) {
2140     assert(C->has_method(), "only for normal compilations");
2141     assert(!C->method()->method_data()->is_empty(), "MDO is needed to record RTM state");
2142     assert(depth() == 1, "generate check only for main compiled method");
2143 
2144     // Set starting bci for uncommon trap.
2145     set_parse_bci(is_osr_parse() ? osr_bci() : 0);
2146 
2147     // Load the rtm_state from the MethodData.
2148     const TypePtr* adr_type = TypeMetadataPtr::make(C->method()->method_data());
2149     Node* mdo = makecon(adr_type);
2150     int offset = MethodData::rtm_state_offset_in_bytes();
2151     Node* adr_node = basic_plus_adr(mdo, mdo, offset);
2152     Node* rtm_state = make_load(control(), adr_node, TypeInt::INT, T_INT, adr_type, MemNode::unordered);
2153 
2154     // Separate Load from Cmp by Opaque.
2155     // In expand_macro_nodes() it will be replaced either
2156     // with this load when there are locks in the code
2157     // or with ProfileRTM (cmp->in(2)) otherwise so that
2158     // the check will fold.
2159     Node* profile_state = makecon(TypeInt::make(ProfileRTM));
2160     Node* opq   = _gvn.transform( new Opaque3Node(C, rtm_state, Opaque3Node::RTM_OPT) );
2161     Node* chk   = _gvn.transform( new CmpINode(opq, profile_state) );
2162     Node* tst   = _gvn.transform( new BoolNode(chk, BoolTest::eq) );
2163     // Branch to failure if state was changed
2164     { BuildCutout unless(this, tst, PROB_ALWAYS);
2165       uncommon_trap(Deoptimization::Reason_rtm_state_change,
2166                     Deoptimization::Action_make_not_entrant);
2167     }
2168   }
2169 #endif
2170 }
2171 
2172 void Parse::decrement_age() {
2173   MethodCounters* mc = method()->ensure_method_counters();
2174   if (mc == NULL) {
2175     C->record_failure("Must have MCs");
2176     return;
2177   }
2178   assert(!is_osr_parse(), "Not doing this for OSRs");
2179 
2180   // Set starting bci for uncommon trap.
2181   set_parse_bci(0);
2182 
2183   const TypePtr* adr_type = TypeRawPtr::make((address)mc);
2184   Node* mc_adr = makecon(adr_type);
2185   Node* cnt_adr = basic_plus_adr(mc_adr, mc_adr, in_bytes(MethodCounters::nmethod_age_offset()));
2186   Node* cnt = make_load(control(), cnt_adr, TypeInt::INT, T_INT, adr_type, MemNode::unordered);
2187   Node* decr = _gvn.transform(new SubINode(cnt, makecon(TypeInt::ONE)));
2188   store_to_memory(control(), cnt_adr, decr, T_INT, adr_type, MemNode::unordered);
2189   Node *chk   = _gvn.transform(new CmpINode(decr, makecon(TypeInt::ZERO)));
2190   Node* tst   = _gvn.transform(new BoolNode(chk, BoolTest::gt));
2191   { BuildCutout unless(this, tst, PROB_ALWAYS);
2192     uncommon_trap(Deoptimization::Reason_tenured,
2193                   Deoptimization::Action_make_not_entrant);
2194   }
2195 }
2196 
2197 //------------------------------return_current---------------------------------
2198 // Append current _map to _exit_return
2199 void Parse::return_current(Node* value) {
2200   if (RegisterFinalizersAtInit &&
2201       method()->intrinsic_id() == vmIntrinsics::_Object_init) {
2202     call_register_finalizer();
2203   }
2204 
2205   // Do not set_parse_bci, so that return goo is credited to the return insn.
2206   set_bci(InvocationEntryBci);
2207   if (method()->is_synchronized() && GenerateSynchronizationCode) {
2208     shared_unlock(_synch_lock->box_node(), _synch_lock->obj_node());
2209   }
2210   if (C->env()->dtrace_method_probes()) {
2211     make_dtrace_method_exit(method());
2212   }
2213   SafePointNode* exit_return = _exits.map();
2214   exit_return->in( TypeFunc::Control  )->add_req( control() );
2215   exit_return->in( TypeFunc::I_O      )->add_req( i_o    () );
2216   Node *mem = exit_return->in( TypeFunc::Memory   );
2217   for (MergeMemStream mms(mem->as_MergeMem(), merged_memory()); mms.next_non_empty2(); ) {
2218     if (mms.is_empty()) {
2219       // get a copy of the base memory, and patch just this one input
2220       const TypePtr* adr_type = mms.adr_type(C);
2221       Node* phi = mms.force_memory()->as_Phi()->slice_memory(adr_type);
2222       assert(phi->as_Phi()->region() == mms.base_memory()->in(0), "");
2223       gvn().set_type_bottom(phi);
2224       phi->del_req(phi->req()-1);  // prepare to re-patch
2225       mms.set_memory(phi);
2226     }
2227     mms.memory()->add_req(mms.memory2());
2228   }
2229 
2230   // frame pointer is always same, already captured
2231   if (value != NULL) {
2232     // If returning oops to an interface-return, there is a silent free
2233     // cast from oop to interface allowed by the Verifier.  Make it explicit
2234     // here.
2235     Node* phi = _exits.argument(0);
2236     const TypeInstPtr *tr = phi->bottom_type()->isa_instptr();
2237     if (tr && tr->klass()->is_loaded() &&
2238         tr->klass()->is_interface()) {
2239       const TypeInstPtr *tp = value->bottom_type()->isa_instptr();
2240       if (tp && tp->klass()->is_loaded() &&
2241           !tp->klass()->is_interface()) {
2242         // sharpen the type eagerly; this eases certain assert checking
2243         if (tp->higher_equal(TypeInstPtr::NOTNULL))
2244           tr = tr->join_speculative(TypeInstPtr::NOTNULL)->is_instptr();
2245         value = _gvn.transform(new CheckCastPPNode(0, value, tr));
2246       }
2247     } else {
2248       // Also handle returns of oop-arrays to an arrays-of-interface return
2249       const TypeInstPtr* phi_tip;
2250       const TypeInstPtr* val_tip;
2251       Type::get_arrays_base_elements(phi->bottom_type(), value->bottom_type(), &phi_tip, &val_tip);
2252       if (phi_tip != NULL && phi_tip->is_loaded() && phi_tip->klass()->is_interface() &&
2253           val_tip != NULL && val_tip->is_loaded() && !val_tip->klass()->is_interface()) {
2254         value = _gvn.transform(new CheckCastPPNode(0, value, phi->bottom_type()));
2255       }
2256     }
2257     phi->add_req(value);
2258   }
2259 
2260   if (_first_return) {
2261     _exits.map()->transfer_replaced_nodes_from(map(), _new_idx);
2262     _first_return = false;
2263   } else {
2264     _exits.map()->merge_replaced_nodes_with(map());
2265   }
2266 
2267   stop_and_kill_map();          // This CFG path dies here
2268 }
2269 
2270 
2271 //------------------------------add_safepoint----------------------------------
2272 void Parse::add_safepoint() {
2273   // See if we can avoid this safepoint.  No need for a SafePoint immediately
2274   // after a Call (except Leaf Call) or another SafePoint.
2275   Node *proj = control();
2276   bool add_poll_param = SafePointNode::needs_polling_address_input();
2277   uint parms = add_poll_param ? TypeFunc::Parms+1 : TypeFunc::Parms;
2278   if( proj->is_Proj() ) {
2279     Node *n0 = proj->in(0);
2280     if( n0->is_Catch() ) {
2281       n0 = n0->in(0)->in(0);
2282       assert( n0->is_Call(), "expect a call here" );
2283     }
2284     if( n0->is_Call() ) {
2285       if( n0->as_Call()->guaranteed_safepoint() )
2286         return;
2287     } else if( n0->is_SafePoint() && n0->req() >= parms ) {
2288       return;
2289     }
2290   }
2291 
2292   // Clear out dead values from the debug info.
2293   kill_dead_locals();
2294 
2295   // Clone the JVM State
2296   SafePointNode *sfpnt = new SafePointNode(parms, NULL);
2297 
2298   // Capture memory state BEFORE a SafePoint.  Since we can block at a
2299   // SafePoint we need our GC state to be safe; i.e. we need all our current
2300   // write barriers (card marks) to not float down after the SafePoint so we
2301   // must read raw memory.  Likewise we need all oop stores to match the card
2302   // marks.  If deopt can happen, we need ALL stores (we need the correct JVM
2303   // state on a deopt).
2304 
2305   // We do not need to WRITE the memory state after a SafePoint.  The control
2306   // edge will keep card-marks and oop-stores from floating up from below a
2307   // SafePoint and our true dependency added here will keep them from floating
2308   // down below a SafePoint.
2309 
2310   // Clone the current memory state
2311   Node* mem = MergeMemNode::make(map()->memory());
2312 
2313   mem = _gvn.transform(mem);
2314 
2315   // Pass control through the safepoint
2316   sfpnt->init_req(TypeFunc::Control  , control());
2317   // Fix edges normally used by a call
2318   sfpnt->init_req(TypeFunc::I_O      , top() );
2319   sfpnt->init_req(TypeFunc::Memory   , mem   );
2320   sfpnt->init_req(TypeFunc::ReturnAdr, top() );
2321   sfpnt->init_req(TypeFunc::FramePtr , top() );
2322 
2323   // Create a node for the polling address
2324   if( add_poll_param ) {
2325     Node *polladr;
2326     if (SafepointMechanism::uses_thread_local_poll()) {
2327       Node *thread = _gvn.transform(new ThreadLocalNode());
2328       Node *polling_page_load_addr = _gvn.transform(basic_plus_adr(top(), thread, in_bytes(Thread::polling_page_offset())));
2329       polladr = make_load(control(), polling_page_load_addr, TypeRawPtr::BOTTOM, T_ADDRESS, Compile::AliasIdxRaw, MemNode::unordered);
2330     } else {
2331       polladr = ConPNode::make((address)os::get_polling_page());
2332     }
2333     sfpnt->init_req(TypeFunc::Parms+0, _gvn.transform(polladr));
2334   }
2335 
2336   // Fix up the JVM State edges
2337   add_safepoint_edges(sfpnt);
2338   Node *transformed_sfpnt = _gvn.transform(sfpnt);
2339   set_control(transformed_sfpnt);
2340 
2341   // Provide an edge from root to safepoint.  This makes the safepoint
2342   // appear useful until the parse has completed.
2343   if( OptoRemoveUseless && transformed_sfpnt->is_SafePoint() ) {
2344     assert(C->root() != NULL, "Expect parse is still valid");
2345     C->root()->add_prec(transformed_sfpnt);
2346   }
2347 }
2348 
2349 #ifndef PRODUCT
2350 //------------------------show_parse_info--------------------------------------
2351 void Parse::show_parse_info() {
2352   InlineTree* ilt = NULL;
2353   if (C->ilt() != NULL) {
2354     JVMState* caller_jvms = is_osr_parse() ? caller()->caller() : caller();
2355     ilt = InlineTree::find_subtree_from_root(C->ilt(), caller_jvms, method());
2356   }
2357   if (PrintCompilation && Verbose) {
2358     if (depth() == 1) {
2359       if( ilt->count_inlines() ) {
2360         tty->print("    __inlined %d (%d bytes)", ilt->count_inlines(),
2361                      ilt->count_inline_bcs());
2362         tty->cr();
2363       }
2364     } else {
2365       if (method()->is_synchronized())         tty->print("s");
2366       if (method()->has_exception_handlers())  tty->print("!");
2367       // Check this is not the final compiled version
2368       if (C->trap_can_recompile()) {
2369         tty->print("-");
2370       } else {
2371         tty->print(" ");
2372       }
2373       method()->print_short_name();
2374       if (is_osr_parse()) {
2375         tty->print(" @ %d", osr_bci());
2376       }
2377       tty->print(" (%d bytes)",method()->code_size());
2378       if (ilt->count_inlines()) {
2379         tty->print(" __inlined %d (%d bytes)", ilt->count_inlines(),
2380                    ilt->count_inline_bcs());
2381       }
2382       tty->cr();
2383     }
2384   }
2385   if (PrintOpto && (depth() == 1 || PrintOptoInlining)) {
2386     // Print that we succeeded; suppress this message on the first osr parse.
2387 
2388     if (method()->is_synchronized())         tty->print("s");
2389     if (method()->has_exception_handlers())  tty->print("!");
2390     // Check this is not the final compiled version
2391     if (C->trap_can_recompile() && depth() == 1) {
2392       tty->print("-");
2393     } else {
2394       tty->print(" ");
2395     }
2396     if( depth() != 1 ) { tty->print("   "); }  // missing compile count
2397     for (int i = 1; i < depth(); ++i) { tty->print("  "); }
2398     method()->print_short_name();
2399     if (is_osr_parse()) {
2400       tty->print(" @ %d", osr_bci());
2401     }
2402     if (ilt->caller_bci() != -1) {
2403       tty->print(" @ %d", ilt->caller_bci());
2404     }
2405     tty->print(" (%d bytes)",method()->code_size());
2406     if (ilt->count_inlines()) {
2407       tty->print(" __inlined %d (%d bytes)", ilt->count_inlines(),
2408                  ilt->count_inline_bcs());
2409     }
2410     tty->cr();
2411   }
2412 }
2413 
2414 
2415 //------------------------------dump-------------------------------------------
2416 // Dump information associated with the bytecodes of current _method
2417 void Parse::dump() {
2418   if( method() != NULL ) {
2419     // Iterate over bytecodes
2420     ciBytecodeStream iter(method());
2421     for( Bytecodes::Code bc = iter.next(); bc != ciBytecodeStream::EOBC() ; bc = iter.next() ) {
2422       dump_bci( iter.cur_bci() );
2423       tty->cr();
2424     }
2425   }
2426 }
2427 
2428 // Dump information associated with a byte code index, 'bci'
2429 void Parse::dump_bci(int bci) {
2430   // Output info on merge-points, cloning, and within _jsr..._ret
2431   // NYI
2432   tty->print(" bci:%d", bci);
2433 }
2434 
2435 #endif