1 /*
   2  * Copyright (c) 1997, 2022, 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 "opto/type.hpp"
  41 #include "runtime/handles.inline.hpp"
  42 #include "runtime/safepointMechanism.hpp"
  43 #include "runtime/sharedRuntime.hpp"
  44 #include "utilities/bitMap.inline.hpp"
  45 #include "utilities/copy.hpp"
  46 
  47 // Static array so we can figure out which bytecodes stop us from compiling
  48 // the most. Some of the non-static variables are needed in bytecodeInfo.cpp
  49 // and eventually should be encapsulated in a proper class (gri 8/18/98).
  50 
  51 #ifndef PRODUCT
  52 int nodes_created              = 0;
  53 int methods_parsed             = 0;
  54 int methods_seen               = 0;
  55 int blocks_parsed              = 0;
  56 int blocks_seen                = 0;
  57 
  58 int explicit_null_checks_inserted = 0;
  59 int explicit_null_checks_elided   = 0;
  60 int all_null_checks_found         = 0;
  61 int implicit_null_checks          = 0;
  62 
  63 bool Parse::BytecodeParseHistogram::_initialized = false;
  64 uint Parse::BytecodeParseHistogram::_bytecodes_parsed [Bytecodes::number_of_codes];
  65 uint Parse::BytecodeParseHistogram::_nodes_constructed[Bytecodes::number_of_codes];
  66 uint Parse::BytecodeParseHistogram::_nodes_transformed[Bytecodes::number_of_codes];
  67 uint Parse::BytecodeParseHistogram::_new_values       [Bytecodes::number_of_codes];
  68 
  69 //------------------------------print_statistics-------------------------------
  70 void Parse::print_statistics() {
  71   tty->print_cr("--- Compiler Statistics ---");
  72   tty->print("Methods seen: %d  Methods parsed: %d", methods_seen, methods_parsed);
  73   tty->print("  Nodes created: %d", nodes_created);
  74   tty->cr();
  75   if (methods_seen != methods_parsed) {
  76     tty->print_cr("Reasons for parse failures (NOT cumulative):");
  77   }
  78   tty->print_cr("Blocks parsed: %d  Blocks seen: %d", blocks_parsed, blocks_seen);
  79 
  80   if (explicit_null_checks_inserted) {
  81     tty->print_cr("%d original NULL checks - %d elided (%2d%%); optimizer leaves %d,",
  82                   explicit_null_checks_inserted, explicit_null_checks_elided,
  83                   (100*explicit_null_checks_elided)/explicit_null_checks_inserted,
  84                   all_null_checks_found);
  85   }
  86   if (all_null_checks_found) {
  87     tty->print_cr("%d made implicit (%2d%%)", implicit_null_checks,
  88                   (100*implicit_null_checks)/all_null_checks_found);
  89   }
  90   if (SharedRuntime::_implicit_null_throws) {
  91     tty->print_cr("%d implicit null exceptions at runtime",
  92                   SharedRuntime::_implicit_null_throws);
  93   }
  94 
  95   if (PrintParseStatistics && BytecodeParseHistogram::initialized()) {
  96     BytecodeParseHistogram::print();
  97   }
  98 }
  99 #endif
 100 
 101 //------------------------------ON STACK REPLACEMENT---------------------------
 102 
 103 // Construct a node which can be used to get incoming state for
 104 // on stack replacement.
 105 Node *Parse::fetch_interpreter_state(int index,
 106                                      BasicType bt,
 107                                      Node *local_addrs,
 108                                      Node *local_addrs_base) {
 109   Node *mem = memory(Compile::AliasIdxRaw);
 110   Node *adr = basic_plus_adr( local_addrs_base, local_addrs, -index*wordSize );
 111   Node *ctl = control();
 112 
 113   // Very similar to LoadNode::make, except we handle un-aligned longs and
 114   // doubles on Sparc.  Intel can handle them just fine directly.
 115   Node *l = NULL;
 116   switch (bt) {                // Signature is flattened
 117   case T_INT:     l = new LoadINode(ctl, mem, adr, TypeRawPtr::BOTTOM, TypeInt::INT,        MemNode::unordered); break;
 118   case T_FLOAT:   l = new LoadFNode(ctl, mem, adr, TypeRawPtr::BOTTOM, Type::FLOAT,         MemNode::unordered); break;
 119   case T_ADDRESS: l = new LoadPNode(ctl, mem, adr, TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM,  MemNode::unordered); break;
 120   case T_OBJECT:  l = new LoadPNode(ctl, mem, adr, TypeRawPtr::BOTTOM, TypeInstPtr::BOTTOM, MemNode::unordered); break;
 121   case T_LONG:
 122   case T_DOUBLE: {
 123     // Since arguments are in reverse order, the argument address 'adr'
 124     // refers to the back half of the long/double.  Recompute adr.
 125     adr = basic_plus_adr(local_addrs_base, local_addrs, -(index+1)*wordSize);
 126     if (Matcher::misaligned_doubles_ok) {
 127       l = (bt == T_DOUBLE)
 128         ? (Node*)new LoadDNode(ctl, mem, adr, TypeRawPtr::BOTTOM, Type::DOUBLE, MemNode::unordered)
 129         : (Node*)new LoadLNode(ctl, mem, adr, TypeRawPtr::BOTTOM, TypeLong::LONG, MemNode::unordered);
 130     } else {
 131       l = (bt == T_DOUBLE)
 132         ? (Node*)new LoadD_unalignedNode(ctl, mem, adr, TypeRawPtr::BOTTOM, MemNode::unordered)
 133         : (Node*)new LoadL_unalignedNode(ctl, mem, adr, TypeRawPtr::BOTTOM, MemNode::unordered);
 134     }
 135     break;
 136   }
 137   default: ShouldNotReachHere();
 138   }
 139   return _gvn.transform(l);
 140 }
 141 
 142 // Helper routine to prevent the interpreter from handing
 143 // unexpected typestate to an OSR method.
 144 // The Node l is a value newly dug out of the interpreter frame.
 145 // The type is the type predicted by ciTypeFlow.  Note that it is
 146 // not a general type, but can only come from Type::get_typeflow_type.
 147 // The safepoint is a map which will feed an uncommon trap.
 148 Node* Parse::check_interpreter_type(Node* l, const Type* type,
 149                                     SafePointNode* &bad_type_exit) {
 150 
 151   const TypeOopPtr* tp = type->isa_oopptr();
 152 
 153   // TypeFlow may assert null-ness if a type appears unloaded.
 154   if (type == TypePtr::NULL_PTR ||
 155       (tp != NULL && !tp->is_loaded())) {
 156     // Value must be null, not a real oop.
 157     Node* chk = _gvn.transform( new CmpPNode(l, null()) );
 158     Node* tst = _gvn.transform( new BoolNode(chk, BoolTest::eq) );
 159     IfNode* iff = create_and_map_if(control(), tst, PROB_MAX, COUNT_UNKNOWN);
 160     set_control(_gvn.transform( new IfTrueNode(iff) ));
 161     Node* bad_type = _gvn.transform( new IfFalseNode(iff) );
 162     bad_type_exit->control()->add_req(bad_type);
 163     l = null();
 164   }
 165 
 166   // Typeflow can also cut off paths from the CFG, based on
 167   // types which appear unloaded, or call sites which appear unlinked.
 168   // When paths are cut off, values at later merge points can rise
 169   // toward more specific classes.  Make sure these specific classes
 170   // are still in effect.
 171   if (tp != NULL && !tp->is_same_java_type_as(TypeInstPtr::BOTTOM)) {
 172     // TypeFlow asserted a specific object type.  Value must have that type.
 173     Node* bad_type_ctrl = NULL;
 174     l = gen_checkcast(l, makecon(tp->as_klass_type()->cast_to_exactness(true)), &bad_type_ctrl);
 175     bad_type_exit->control()->add_req(bad_type_ctrl);
 176   }
 177 
 178   BasicType bt_l = _gvn.type(l)->basic_type();
 179   BasicType bt_t = type->basic_type();
 180   assert(_gvn.type(l)->higher_equal(type), "must constrain OSR typestate");
 181   return l;
 182 }
 183 
 184 // Helper routine which sets up elements of the initial parser map when
 185 // performing a parse for on stack replacement.  Add values into map.
 186 // The only parameter contains the address of a interpreter arguments.
 187 void Parse::load_interpreter_state(Node* osr_buf) {
 188   int index;
 189   int max_locals = jvms()->loc_size();
 190   int max_stack  = jvms()->stk_size();
 191 
 192 
 193   // Mismatch between method and jvms can occur since map briefly held
 194   // an OSR entry state (which takes up one RawPtr word).
 195   assert(max_locals == method()->max_locals(), "sanity");
 196   assert(max_stack  >= method()->max_stack(),  "sanity");
 197   assert((int)jvms()->endoff() == TypeFunc::Parms + max_locals + max_stack, "sanity");
 198   assert((int)jvms()->endoff() == (int)map()->req(), "sanity");
 199 
 200   // Find the start block.
 201   Block* osr_block = start_block();
 202   assert(osr_block->start() == osr_bci(), "sanity");
 203 
 204   // Set initial BCI.
 205   set_parse_bci(osr_block->start());
 206 
 207   // Set initial stack depth.
 208   set_sp(osr_block->start_sp());
 209 
 210   // Check bailouts.  We currently do not perform on stack replacement
 211   // of loops in catch blocks or loops which branch with a non-empty stack.
 212   if (sp() != 0) {
 213     C->record_method_not_compilable("OSR starts with non-empty stack");
 214     return;
 215   }
 216   // Do not OSR inside finally clauses:
 217   if (osr_block->has_trap_at(osr_block->start())) {
 218     C->record_method_not_compilable("OSR starts with an immediate trap");
 219     return;
 220   }
 221 
 222   // Commute monitors from interpreter frame to compiler frame.
 223   assert(jvms()->monitor_depth() == 0, "should be no active locks at beginning of osr");
 224   int mcnt = osr_block->flow()->monitor_count();
 225   Node *monitors_addr = basic_plus_adr(osr_buf, osr_buf, (max_locals+mcnt*2-1)*wordSize);
 226   for (index = 0; index < mcnt; index++) {
 227     // Make a BoxLockNode for the monitor.
 228     Node *box = _gvn.transform(new BoxLockNode(next_monitor()));
 229 
 230 
 231     // Displaced headers and locked objects are interleaved in the
 232     // temp OSR buffer.  We only copy the locked objects out here.
 233     // Fetch the locked object from the OSR temp buffer and copy to our fastlock node.
 234     Node *lock_object = fetch_interpreter_state(index*2, T_OBJECT, monitors_addr, osr_buf);
 235     // Try and copy the displaced header to the BoxNode
 236     Node *displaced_hdr = fetch_interpreter_state((index*2) + 1, T_ADDRESS, monitors_addr, osr_buf);
 237 
 238 
 239     store_to_memory(control(), box, displaced_hdr, T_ADDRESS, Compile::AliasIdxRaw, MemNode::unordered);
 240 
 241     // Build a bogus FastLockNode (no code will be generated) and push the
 242     // monitor into our debug info.
 243     const FastLockNode *flock = _gvn.transform(new FastLockNode( 0, lock_object, box ))->as_FastLock();
 244     map()->push_monitor(flock);
 245 
 246     // If the lock is our method synchronization lock, tuck it away in
 247     // _sync_lock for return and rethrow exit paths.
 248     if (index == 0 && method()->is_synchronized()) {
 249       _synch_lock = flock;
 250     }
 251   }
 252 
 253   // Use the raw liveness computation to make sure that unexpected
 254   // values don't propagate into the OSR frame.
 255   MethodLivenessResult live_locals = method()->liveness_at_bci(osr_bci());
 256   if (!live_locals.is_valid()) {
 257     // Degenerate or breakpointed method.
 258     C->record_method_not_compilable("OSR in empty or breakpointed method");
 259     return;
 260   }
 261 
 262   // Extract the needed locals from the interpreter frame.
 263   Node *locals_addr = basic_plus_adr(osr_buf, osr_buf, (max_locals-1)*wordSize);
 264 
 265   // find all the locals that the interpreter thinks contain live oops
 266   const ResourceBitMap live_oops = method()->live_local_oops_at_bci(osr_bci());
 267   for (index = 0; index < max_locals; index++) {
 268 
 269     if (!live_locals.at(index)) {
 270       continue;
 271     }
 272 
 273     const Type *type = osr_block->local_type_at(index);
 274 
 275     if (type->isa_oopptr() != NULL) {
 276 
 277       // 6403625: Verify that the interpreter oopMap thinks that the oop is live
 278       // else we might load a stale oop if the MethodLiveness disagrees with the
 279       // result of the interpreter. If the interpreter says it is dead we agree
 280       // by making the value go to top.
 281       //
 282 
 283       if (!live_oops.at(index)) {
 284         if (C->log() != NULL) {
 285           C->log()->elem("OSR_mismatch local_index='%d'",index);
 286         }
 287         set_local(index, null());
 288         // and ignore it for the loads
 289         continue;
 290       }
 291     }
 292 
 293     // Filter out TOP, HALF, and BOTTOM.  (Cf. ensure_phi.)
 294     if (type == Type::TOP || type == Type::HALF) {
 295       continue;
 296     }
 297     // If the type falls to bottom, then this must be a local that
 298     // is mixing ints and oops or some such.  Forcing it to top
 299     // makes it go dead.
 300     if (type == Type::BOTTOM) {
 301       continue;
 302     }
 303     // Construct code to access the appropriate local.
 304     BasicType bt = type->basic_type();
 305     if (type == TypePtr::NULL_PTR) {
 306       // Ptr types are mixed together with T_ADDRESS but NULL is
 307       // really for T_OBJECT types so correct it.
 308       bt = T_OBJECT;
 309     }
 310     Node *value = fetch_interpreter_state(index, bt, locals_addr, osr_buf);
 311     set_local(index, value);
 312   }
 313 
 314   // Extract the needed stack entries from the interpreter frame.
 315   for (index = 0; index < sp(); index++) {
 316     const Type *type = osr_block->stack_type_at(index);
 317     if (type != Type::TOP) {
 318       // Currently the compiler bails out when attempting to on stack replace
 319       // at a bci with a non-empty stack.  We should not reach here.
 320       ShouldNotReachHere();
 321     }
 322   }
 323 
 324   // End the OSR migration
 325   make_runtime_call(RC_LEAF, OptoRuntime::osr_end_Type(),
 326                     CAST_FROM_FN_PTR(address, SharedRuntime::OSR_migration_end),
 327                     "OSR_migration_end", TypeRawPtr::BOTTOM,
 328                     osr_buf);
 329 
 330   // Now that the interpreter state is loaded, make sure it will match
 331   // at execution time what the compiler is expecting now:
 332   SafePointNode* bad_type_exit = clone_map();
 333   bad_type_exit->set_control(new RegionNode(1));
 334 
 335   assert(osr_block->flow()->jsrs()->size() == 0, "should be no jsrs live at osr point");
 336   for (index = 0; index < max_locals; index++) {
 337     if (stopped())  break;
 338     Node* l = local(index);
 339     if (l->is_top())  continue;  // nothing here
 340     const Type *type = osr_block->local_type_at(index);
 341     if (type->isa_oopptr() != NULL) {
 342       if (!live_oops.at(index)) {
 343         // skip type check for dead oops
 344         continue;
 345       }
 346     }
 347     if (osr_block->flow()->local_type_at(index)->is_return_address()) {
 348       // In our current system it's illegal for jsr addresses to be
 349       // live into an OSR entry point because the compiler performs
 350       // inlining of jsrs.  ciTypeFlow has a bailout that detect this
 351       // case and aborts the compile if addresses are live into an OSR
 352       // entry point.  Because of that we can assume that any address
 353       // locals at the OSR entry point are dead.  Method liveness
 354       // isn't precise enough to figure out that they are dead in all
 355       // cases so simply skip checking address locals all
 356       // together. Any type check is guaranteed to fail since the
 357       // interpreter type is the result of a load which might have any
 358       // value and the expected type is a constant.
 359       continue;
 360     }
 361     set_local(index, check_interpreter_type(l, type, bad_type_exit));
 362   }
 363 
 364   for (index = 0; index < sp(); index++) {
 365     if (stopped())  break;
 366     Node* l = stack(index);
 367     if (l->is_top())  continue;  // nothing here
 368     const Type *type = osr_block->stack_type_at(index);
 369     set_stack(index, check_interpreter_type(l, type, bad_type_exit));
 370   }
 371 
 372   if (bad_type_exit->control()->req() > 1) {
 373     // Build an uncommon trap here, if any inputs can be unexpected.
 374     bad_type_exit->set_control(_gvn.transform( bad_type_exit->control() ));
 375     record_for_igvn(bad_type_exit->control());
 376     SafePointNode* types_are_good = map();
 377     set_map(bad_type_exit);
 378     // The unexpected type happens because a new edge is active
 379     // in the CFG, which typeflow had previously ignored.
 380     // E.g., Object x = coldAtFirst() && notReached()? "str": new Integer(123).
 381     // This x will be typed as Integer if notReached is not yet linked.
 382     // It could also happen due to a problem in ciTypeFlow analysis.
 383     uncommon_trap(Deoptimization::Reason_constraint,
 384                   Deoptimization::Action_reinterpret);
 385     set_map(types_are_good);
 386   }
 387 }
 388 
 389 //------------------------------Parse------------------------------------------
 390 // Main parser constructor.
 391 Parse::Parse(JVMState* caller, ciMethod* parse_method, float expected_uses)
 392   : _exits(caller)
 393 {
 394   // Init some variables
 395   _caller = caller;
 396   _method = parse_method;
 397   _expected_uses = expected_uses;
 398   _depth = 1 + (caller->has_method() ? caller->depth() : 0);
 399   _wrote_final = false;
 400   _wrote_volatile = false;
 401   _wrote_stable = false;
 402   _wrote_fields = false;
 403   _alloc_with_final = NULL;
 404   _entry_bci = InvocationEntryBci;
 405   _tf = NULL;
 406   _block = NULL;
 407   _first_return = true;
 408   _replaced_nodes_for_exceptions = false;
 409   _new_idx = C->unique();
 410   debug_only(_block_count = -1);
 411   debug_only(_blocks = (Block*)-1);
 412 #ifndef PRODUCT
 413   if (PrintCompilation || PrintOpto) {
 414     // Make sure I have an inline tree, so I can print messages about it.
 415     JVMState* ilt_caller = is_osr_parse() ? caller->caller() : caller;
 416     InlineTree::find_subtree_from_root(C->ilt(), ilt_caller, parse_method);
 417   }
 418   _max_switch_depth = 0;
 419   _est_switch_depth = 0;
 420 #endif
 421 
 422   if (parse_method->has_reserved_stack_access()) {
 423     C->set_has_reserved_stack_access(true);
 424   }
 425 
 426   if (parse_method->is_synchronized()) {
 427     C->set_has_monitors(true);
 428   }
 429 
 430   _tf = TypeFunc::make(method());
 431   _iter.reset_to_method(method());
 432   _flow = method()->get_flow_analysis();
 433   if (_flow->failing()) {
 434     C->record_method_not_compilable(_flow->failure_reason());
 435   }
 436 
 437 #ifndef PRODUCT
 438   if (_flow->has_irreducible_entry()) {
 439     C->set_parsed_irreducible_loop(true);
 440   }
 441 #endif
 442   C->set_has_loops(C->has_loops() || method()->has_loops());
 443 
 444   if (_expected_uses <= 0) {
 445     _prof_factor = 1;
 446   } else {
 447     float prof_total = parse_method->interpreter_invocation_count();
 448     if (prof_total <= _expected_uses) {
 449       _prof_factor = 1;
 450     } else {
 451       _prof_factor = _expected_uses / prof_total;
 452     }
 453   }
 454 
 455   CompileLog* log = C->log();
 456   if (log != NULL) {
 457     log->begin_head("parse method='%d' uses='%f'",
 458                     log->identify(parse_method), expected_uses);
 459     if (depth() == 1 && C->is_osr_compilation()) {
 460       log->print(" osr_bci='%d'", C->entry_bci());
 461     }
 462     log->stamp();
 463     log->end_head();
 464   }
 465 
 466   // Accumulate deoptimization counts.
 467   // (The range_check and store_check counts are checked elsewhere.)
 468   ciMethodData* md = method()->method_data();
 469   for (uint reason = 0; reason < md->trap_reason_limit(); reason++) {
 470     uint md_count = md->trap_count(reason);
 471     if (md_count != 0) {
 472       if (md_count == md->trap_count_limit())
 473         md_count += md->overflow_trap_count();
 474       uint total_count = C->trap_count(reason);
 475       uint old_count   = total_count;
 476       total_count += md_count;
 477       // Saturate the add if it overflows.
 478       if (total_count < old_count || total_count < md_count)
 479         total_count = (uint)-1;
 480       C->set_trap_count(reason, total_count);
 481       if (log != NULL)
 482         log->elem("observe trap='%s' count='%d' total='%d'",
 483                   Deoptimization::trap_reason_name(reason),
 484                   md_count, total_count);
 485     }
 486   }
 487   // Accumulate total sum of decompilations, also.
 488   C->set_decompile_count(C->decompile_count() + md->decompile_count());
 489 
 490   if (log != NULL && method()->has_exception_handlers()) {
 491     log->elem("observe that='has_exception_handlers'");
 492   }
 493 
 494   assert(InlineTree::check_can_parse(method()) == NULL, "Can not parse this method, cutout earlier");
 495   assert(method()->has_balanced_monitors(), "Can not parse unbalanced monitors, cutout earlier");
 496 
 497   // Always register dependence if JVMTI is enabled, because
 498   // either breakpoint setting or hotswapping of methods may
 499   // cause deoptimization.
 500   if (C->env()->jvmti_can_hotswap_or_post_breakpoint()) {
 501     C->dependencies()->assert_evol_method(method());
 502   }
 503 
 504   NOT_PRODUCT(methods_seen++);
 505 
 506   // Do some special top-level things.
 507   if (depth() == 1 && C->is_osr_compilation()) {
 508     _entry_bci = C->entry_bci();
 509     _flow = method()->get_osr_flow_analysis(osr_bci());
 510     if (_flow->failing()) {
 511       C->record_method_not_compilable(_flow->failure_reason());
 512 #ifndef PRODUCT
 513       if (PrintOpto && (Verbose || WizardMode)) {
 514         tty->print_cr("OSR @%d type flow bailout: %s", _entry_bci, _flow->failure_reason());
 515         if (Verbose) {
 516           method()->print();
 517           method()->print_codes();
 518           _flow->print();
 519         }
 520       }
 521 #endif
 522     }
 523     _tf = C->tf();     // the OSR entry type is different
 524   }
 525 
 526 #ifdef ASSERT
 527   if (depth() == 1) {
 528     assert(C->is_osr_compilation() == this->is_osr_parse(), "OSR in sync");
 529   } else {
 530     assert(!this->is_osr_parse(), "no recursive OSR");
 531   }
 532 #endif
 533 
 534 #ifndef PRODUCT
 535   methods_parsed++;
 536   // add method size here to guarantee that inlined methods are added too
 537   if (CITime)
 538     _total_bytes_compiled += method()->code_size();
 539 
 540   show_parse_info();
 541 #endif
 542 
 543   if (failing()) {
 544     if (log)  log->done("parse");
 545     return;
 546   }
 547 
 548   gvn().set_type(root(), root()->bottom_type());
 549   gvn().transform(top());
 550 
 551   // Import the results of the ciTypeFlow.
 552   init_blocks();
 553 
 554   // Merge point for all normal exits
 555   build_exits();
 556 
 557   // Setup the initial JVM state map.
 558   SafePointNode* entry_map = create_entry_map();
 559 
 560   // Check for bailouts during map initialization
 561   if (failing() || entry_map == NULL) {
 562     if (log)  log->done("parse");
 563     return;
 564   }
 565 
 566   Node_Notes* caller_nn = C->default_node_notes();
 567   // Collect debug info for inlined calls unless -XX:-DebugInlinedCalls.
 568   if (DebugInlinedCalls || depth() == 1) {
 569     C->set_default_node_notes(make_node_notes(caller_nn));
 570   }
 571 
 572   if (is_osr_parse()) {
 573     Node* osr_buf = entry_map->in(TypeFunc::Parms+0);
 574     entry_map->set_req(TypeFunc::Parms+0, top());
 575     set_map(entry_map);
 576     load_interpreter_state(osr_buf);
 577   } else {
 578     set_map(entry_map);
 579     do_method_entry();
 580   }
 581 
 582   if (depth() == 1 && !failing()) {
 583     if (C->clinit_barrier_on_entry()) {
 584       // Add check to deoptimize the nmethod once the holder class is fully initialized
 585       clinit_deopt();
 586     }
 587 
 588     // Add check to deoptimize the nmethod if RTM state was changed
 589     rtm_deopt();
 590   }
 591 
 592   // Check for bailouts during method entry or RTM state check setup.
 593   if (failing()) {
 594     if (log)  log->done("parse");
 595     C->set_default_node_notes(caller_nn);
 596     return;
 597   }
 598 
 599   entry_map = map();  // capture any changes performed by method setup code
 600   assert(jvms()->endoff() == map()->req(), "map matches JVMS layout");
 601 
 602   // We begin parsing as if we have just encountered a jump to the
 603   // method entry.
 604   Block* entry_block = start_block();
 605   assert(entry_block->start() == (is_osr_parse() ? osr_bci() : 0), "");
 606   set_map_clone(entry_map);
 607   merge_common(entry_block, entry_block->next_path_num());
 608 
 609 #ifndef PRODUCT
 610   BytecodeParseHistogram *parse_histogram_obj = new (C->env()->arena()) BytecodeParseHistogram(this, C);
 611   set_parse_histogram( parse_histogram_obj );
 612 #endif
 613 
 614   // Parse all the basic blocks.
 615   do_all_blocks();
 616 
 617   C->set_default_node_notes(caller_nn);
 618 
 619   // Check for bailouts during conversion to graph
 620   if (failing()) {
 621     if (log)  log->done("parse");
 622     return;
 623   }
 624 
 625   // Fix up all exiting control flow.
 626   set_map(entry_map);
 627   do_exits();
 628 
 629   if (log)  log->done("parse nodes='%d' live='%d' memory='" SIZE_FORMAT "'",
 630                       C->unique(), C->live_nodes(), C->node_arena()->used());
 631 }
 632 
 633 //---------------------------do_all_blocks-------------------------------------
 634 void Parse::do_all_blocks() {
 635   bool has_irreducible = flow()->has_irreducible_entry();
 636 
 637   // Walk over all blocks in Reverse Post-Order.
 638   while (true) {
 639     bool progress = false;
 640     for (int rpo = 0; rpo < block_count(); rpo++) {
 641       Block* block = rpo_at(rpo);
 642 
 643       if (block->is_parsed()) continue;
 644 
 645       if (!block->is_merged()) {
 646         // Dead block, no state reaches this block
 647         continue;
 648       }
 649 
 650       // Prepare to parse this block.
 651       load_state_from(block);
 652 
 653       if (stopped()) {
 654         // Block is dead.
 655         continue;
 656       }
 657 
 658       NOT_PRODUCT(blocks_parsed++);
 659 
 660       progress = true;
 661       if (block->is_loop_head() || block->is_handler() || (has_irreducible && !block->is_ready())) {
 662         // Not all preds have been parsed.  We must build phis everywhere.
 663         // (Note that dead locals do not get phis built, ever.)
 664         ensure_phis_everywhere();
 665 
 666         if (block->is_SEL_head()) {
 667           // Add predicate to single entry (not irreducible) loop head.
 668           assert(!block->has_merged_backedge(), "only entry paths should be merged for now");
 669           // Predicates may have been added after a dominating if
 670           if (!block->has_predicates()) {
 671             // Need correct bci for predicate.
 672             // It is fine to set it here since do_one_block() will set it anyway.
 673             set_parse_bci(block->start());
 674             add_empty_predicates();
 675           }
 676           // Add new region for back branches.
 677           int edges = block->pred_count() - block->preds_parsed() + 1; // +1 for original region
 678           RegionNode *r = new RegionNode(edges+1);
 679           _gvn.set_type(r, Type::CONTROL);
 680           record_for_igvn(r);
 681           r->init_req(edges, control());
 682           set_control(r);
 683           // Add new phis.
 684           ensure_phis_everywhere();
 685         }
 686 
 687         // Leave behind an undisturbed copy of the map, for future merges.
 688         set_map(clone_map());
 689       }
 690 
 691       if (control()->is_Region() && !block->is_loop_head() && !has_irreducible && !block->is_handler()) {
 692         // In the absence of irreducible loops, the Region and Phis
 693         // associated with a merge that doesn't involve a backedge can
 694         // be simplified now since the RPO parsing order guarantees
 695         // that any path which was supposed to reach here has already
 696         // been parsed or must be dead.
 697         Node* c = control();
 698         Node* result = _gvn.transform_no_reclaim(control());
 699         if (c != result && TraceOptoParse) {
 700           tty->print_cr("Block #%d replace %d with %d", block->rpo(), c->_idx, result->_idx);
 701         }
 702         if (result != top()) {
 703           record_for_igvn(result);
 704         }
 705       }
 706 
 707       // Parse the block.
 708       do_one_block();
 709 
 710       // Check for bailouts.
 711       if (failing())  return;
 712     }
 713 
 714     // with irreducible loops multiple passes might be necessary to parse everything
 715     if (!has_irreducible || !progress) {
 716       break;
 717     }
 718   }
 719 
 720 #ifndef PRODUCT
 721   blocks_seen += block_count();
 722 
 723   // Make sure there are no half-processed blocks remaining.
 724   // Every remaining unprocessed block is dead and may be ignored now.
 725   for (int rpo = 0; rpo < block_count(); rpo++) {
 726     Block* block = rpo_at(rpo);
 727     if (!block->is_parsed()) {
 728       if (TraceOptoParse) {
 729         tty->print_cr("Skipped dead block %d at bci:%d", rpo, block->start());
 730       }
 731       assert(!block->is_merged(), "no half-processed blocks");
 732     }
 733   }
 734 #endif
 735 }
 736 
 737 static Node* mask_int_value(Node* v, BasicType bt, PhaseGVN* gvn) {
 738   switch (bt) {
 739   case T_BYTE:
 740     v = gvn->transform(new LShiftINode(v, gvn->intcon(24)));
 741     v = gvn->transform(new RShiftINode(v, gvn->intcon(24)));
 742     break;
 743   case T_SHORT:
 744     v = gvn->transform(new LShiftINode(v, gvn->intcon(16)));
 745     v = gvn->transform(new RShiftINode(v, gvn->intcon(16)));
 746     break;
 747   case T_CHAR:
 748     v = gvn->transform(new AndINode(v, gvn->intcon(0xFFFF)));
 749     break;
 750   case T_BOOLEAN:
 751     v = gvn->transform(new AndINode(v, gvn->intcon(0x1)));
 752     break;
 753   default:
 754     break;
 755   }
 756   return v;
 757 }
 758 
 759 //-------------------------------build_exits----------------------------------
 760 // Build normal and exceptional exit merge points.
 761 void Parse::build_exits() {
 762   // make a clone of caller to prevent sharing of side-effects
 763   _exits.set_map(_exits.clone_map());
 764   _exits.clean_stack(_exits.sp());
 765   _exits.sync_jvms();
 766 
 767   RegionNode* region = new RegionNode(1);
 768   record_for_igvn(region);
 769   gvn().set_type_bottom(region);
 770   _exits.set_control(region);
 771 
 772   // Note:  iophi and memphi are not transformed until do_exits.
 773   Node* iophi  = new PhiNode(region, Type::ABIO);
 774   Node* memphi = new PhiNode(region, Type::MEMORY, TypePtr::BOTTOM);
 775   gvn().set_type_bottom(iophi);
 776   gvn().set_type_bottom(memphi);
 777   _exits.set_i_o(iophi);
 778   _exits.set_all_memory(memphi);
 779 
 780   // Add a return value to the exit state.  (Do not push it yet.)
 781   if (tf()->range()->cnt() > TypeFunc::Parms) {
 782     const Type* ret_type = tf()->range()->field_at(TypeFunc::Parms);
 783     if (ret_type->isa_int()) {
 784       BasicType ret_bt = method()->return_type()->basic_type();
 785       if (ret_bt == T_BOOLEAN ||
 786           ret_bt == T_CHAR ||
 787           ret_bt == T_BYTE ||
 788           ret_bt == T_SHORT) {
 789         ret_type = TypeInt::INT;
 790       }
 791     }
 792 
 793     // Don't "bind" an unloaded return klass to the ret_phi. If the klass
 794     // becomes loaded during the subsequent parsing, the loaded and unloaded
 795     // types will not join when we transform and push in do_exits().
 796     const TypeOopPtr* ret_oop_type = ret_type->isa_oopptr();
 797     if (ret_oop_type && !ret_oop_type->is_loaded()) {
 798       ret_type = TypeOopPtr::BOTTOM;
 799     }
 800     int         ret_size = type2size[ret_type->basic_type()];
 801     Node*       ret_phi  = new PhiNode(region, ret_type);
 802     gvn().set_type_bottom(ret_phi);
 803     _exits.ensure_stack(ret_size);
 804     assert((int)(tf()->range()->cnt() - TypeFunc::Parms) == ret_size, "good tf range");
 805     assert(method()->return_type()->size() == ret_size, "tf agrees w/ method");
 806     _exits.set_argument(0, ret_phi);  // here is where the parser finds it
 807     // Note:  ret_phi is not yet pushed, until do_exits.
 808   }
 809 }
 810 
 811 
 812 //----------------------------build_start_state-------------------------------
 813 // Construct a state which contains only the incoming arguments from an
 814 // unknown caller.  The method & bci will be NULL & InvocationEntryBci.
 815 JVMState* Compile::build_start_state(StartNode* start, const TypeFunc* tf) {
 816   int        arg_size = tf->domain()->cnt();
 817   int        max_size = MAX2(arg_size, (int)tf->range()->cnt());
 818   JVMState*  jvms     = new (this) JVMState(max_size - TypeFunc::Parms);
 819   SafePointNode* map  = new SafePointNode(max_size, jvms);
 820   record_for_igvn(map);
 821   assert(arg_size == TypeFunc::Parms + (is_osr_compilation() ? 1 : method()->arg_size()), "correct arg_size");
 822   Node_Notes* old_nn = default_node_notes();
 823   if (old_nn != NULL && has_method()) {
 824     Node_Notes* entry_nn = old_nn->clone(this);
 825     JVMState* entry_jvms = new(this) JVMState(method(), old_nn->jvms());
 826     entry_jvms->set_offsets(0);
 827     entry_jvms->set_bci(entry_bci());
 828     entry_nn->set_jvms(entry_jvms);
 829     set_default_node_notes(entry_nn);
 830   }
 831   uint i;
 832   for (i = 0; i < (uint)arg_size; i++) {
 833     Node* parm = initial_gvn()->transform(new ParmNode(start, i));
 834     map->init_req(i, parm);
 835     // Record all these guys for later GVN.
 836     record_for_igvn(parm);
 837   }
 838   for (; i < map->req(); i++) {
 839     map->init_req(i, top());
 840   }
 841   assert(jvms->argoff() == TypeFunc::Parms, "parser gets arguments here");
 842   set_default_node_notes(old_nn);
 843   jvms->set_map(map);
 844   return jvms;
 845 }
 846 
 847 //-----------------------------make_node_notes---------------------------------
 848 Node_Notes* Parse::make_node_notes(Node_Notes* caller_nn) {
 849   if (caller_nn == NULL)  return NULL;
 850   Node_Notes* nn = caller_nn->clone(C);
 851   JVMState* caller_jvms = nn->jvms();
 852   JVMState* jvms = new (C) JVMState(method(), caller_jvms);
 853   jvms->set_offsets(0);
 854   jvms->set_bci(_entry_bci);
 855   nn->set_jvms(jvms);
 856   return nn;
 857 }
 858 
 859 
 860 //--------------------------return_values--------------------------------------
 861 void Compile::return_values(JVMState* jvms) {
 862   GraphKit kit(jvms);
 863   Node* ret = new ReturnNode(TypeFunc::Parms,
 864                              kit.control(),
 865                              kit.i_o(),
 866                              kit.reset_memory(),
 867                              kit.frameptr(),
 868                              kit.returnadr());
 869   // Add zero or 1 return values
 870   int ret_size = tf()->range()->cnt() - TypeFunc::Parms;
 871   if (ret_size > 0) {
 872     kit.inc_sp(-ret_size);  // pop the return value(s)
 873     kit.sync_jvms();
 874     ret->add_req(kit.argument(0));
 875     // Note:  The second dummy edge is not needed by a ReturnNode.
 876   }
 877   // bind it to root
 878   root()->add_req(ret);
 879   record_for_igvn(ret);
 880   initial_gvn()->transform_no_reclaim(ret);
 881 }
 882 
 883 //------------------------rethrow_exceptions-----------------------------------
 884 // Bind all exception states in the list into a single RethrowNode.
 885 void Compile::rethrow_exceptions(JVMState* jvms) {
 886   GraphKit kit(jvms);
 887   if (!kit.has_exceptions())  return;  // nothing to generate
 888   // Load my combined exception state into the kit, with all phis transformed:
 889   SafePointNode* ex_map = kit.combine_and_pop_all_exception_states();
 890   Node* ex_oop = kit.use_exception_state(ex_map);
 891   RethrowNode* exit = new RethrowNode(kit.control(),
 892                                       kit.i_o(), kit.reset_memory(),
 893                                       kit.frameptr(), kit.returnadr(),
 894                                       // like a return but with exception input
 895                                       ex_oop);
 896   // bind to root
 897   root()->add_req(exit);
 898   record_for_igvn(exit);
 899   initial_gvn()->transform_no_reclaim(exit);
 900 }
 901 
 902 //---------------------------do_exceptions-------------------------------------
 903 // Process exceptions arising from the current bytecode.
 904 // Send caught exceptions to the proper handler within this method.
 905 // Unhandled exceptions feed into _exit.
 906 void Parse::do_exceptions() {
 907   if (!has_exceptions())  return;
 908 
 909   if (failing()) {
 910     // Pop them all off and throw them away.
 911     while (pop_exception_state() != NULL) ;
 912     return;
 913   }
 914 
 915   PreserveJVMState pjvms(this, false);
 916 
 917   SafePointNode* ex_map;
 918   while ((ex_map = pop_exception_state()) != NULL) {
 919     if (!method()->has_exception_handlers()) {
 920       // Common case:  Transfer control outward.
 921       // Doing it this early allows the exceptions to common up
 922       // even between adjacent method calls.
 923       throw_to_exit(ex_map);
 924     } else {
 925       // Have to look at the exception first.
 926       assert(stopped(), "catch_inline_exceptions trashes the map");
 927       catch_inline_exceptions(ex_map);
 928       stop_and_kill_map();      // we used up this exception state; kill it
 929     }
 930   }
 931 
 932   // We now return to our regularly scheduled program:
 933 }
 934 
 935 //---------------------------throw_to_exit-------------------------------------
 936 // Merge the given map into an exception exit from this method.
 937 // The exception exit will handle any unlocking of receiver.
 938 // The ex_oop must be saved within the ex_map, unlike merge_exception.
 939 void Parse::throw_to_exit(SafePointNode* ex_map) {
 940   // Pop the JVMS to (a copy of) the caller.
 941   GraphKit caller;
 942   caller.set_map_clone(_caller->map());
 943   caller.set_bci(_caller->bci());
 944   caller.set_sp(_caller->sp());
 945   // Copy out the standard machine state:
 946   for (uint i = 0; i < TypeFunc::Parms; i++) {
 947     caller.map()->set_req(i, ex_map->in(i));
 948   }
 949   if (ex_map->has_replaced_nodes()) {
 950     _replaced_nodes_for_exceptions = true;
 951   }
 952   caller.map()->transfer_replaced_nodes_from(ex_map, _new_idx);
 953   // ...and the exception:
 954   Node*          ex_oop        = saved_ex_oop(ex_map);
 955   SafePointNode* caller_ex_map = caller.make_exception_state(ex_oop);
 956   // Finally, collect the new exception state in my exits:
 957   _exits.add_exception_state(caller_ex_map);
 958 }
 959 
 960 //------------------------------do_exits---------------------------------------
 961 void Parse::do_exits() {
 962   set_parse_bci(InvocationEntryBci);
 963 
 964   // Now peephole on the return bits
 965   Node* region = _exits.control();
 966   _exits.set_control(gvn().transform(region));
 967 
 968   Node* iophi = _exits.i_o();
 969   _exits.set_i_o(gvn().transform(iophi));
 970 
 971   // Figure out if we need to emit the trailing barrier. The barrier is only
 972   // needed in the constructors, and only in three cases:
 973   //
 974   // 1. The constructor wrote a final. The effects of all initializations
 975   //    must be committed to memory before any code after the constructor
 976   //    publishes the reference to the newly constructed object. Rather
 977   //    than wait for the publication, we simply block the writes here.
 978   //    Rather than put a barrier on only those writes which are required
 979   //    to complete, we force all writes to complete.
 980   //
 981   // 2. Experimental VM option is used to force the barrier if any field
 982   //    was written out in the constructor.
 983   //
 984   // 3. On processors which are not CPU_MULTI_COPY_ATOMIC (e.g. PPC64),
 985   //    support_IRIW_for_not_multiple_copy_atomic_cpu selects that
 986   //    MemBarVolatile is used before volatile load instead of after volatile
 987   //    store, so there's no barrier after the store.
 988   //    We want to guarantee the same behavior as on platforms with total store
 989   //    order, although this is not required by the Java memory model.
 990   //    In this case, we want to enforce visibility of volatile field
 991   //    initializations which are performed in constructors.
 992   //    So as with finals, we add a barrier here.
 993   //
 994   // "All bets are off" unless the first publication occurs after a
 995   // normal return from the constructor.  We do not attempt to detect
 996   // such unusual early publications.  But no barrier is needed on
 997   // exceptional returns, since they cannot publish normally.
 998   //
 999   if (method()->is_initializer() &&
1000        (wrote_final() ||
1001          (AlwaysSafeConstructors && wrote_fields()) ||
1002          (support_IRIW_for_not_multiple_copy_atomic_cpu && wrote_volatile()))) {
1003     _exits.insert_mem_bar(Op_MemBarRelease, alloc_with_final());
1004 
1005     // If Memory barrier is created for final fields write
1006     // and allocation node does not escape the initialize method,
1007     // then barrier introduced by allocation node can be removed.
1008     if (DoEscapeAnalysis && alloc_with_final()) {
1009       AllocateNode *alloc = AllocateNode::Ideal_allocation(alloc_with_final(), &_gvn);
1010       alloc->compute_MemBar_redundancy(method());
1011     }
1012     if (PrintOpto && (Verbose || WizardMode)) {
1013       method()->print_name();
1014       tty->print_cr(" writes finals and needs a memory barrier");
1015     }
1016   }
1017 
1018   // Any method can write a @Stable field; insert memory barriers
1019   // after those also. Can't bind predecessor allocation node (if any)
1020   // with barrier because allocation doesn't always dominate
1021   // MemBarRelease.
1022   if (wrote_stable()) {
1023     _exits.insert_mem_bar(Op_MemBarRelease);
1024     if (PrintOpto && (Verbose || WizardMode)) {
1025       method()->print_name();
1026       tty->print_cr(" writes @Stable and needs a memory barrier");
1027     }
1028   }
1029 
1030   for (MergeMemStream mms(_exits.merged_memory()); mms.next_non_empty(); ) {
1031     // transform each slice of the original memphi:
1032     mms.set_memory(_gvn.transform(mms.memory()));
1033   }
1034   // Clean up input MergeMems created by transforming the slices
1035   _gvn.transform(_exits.merged_memory());
1036 
1037   if (tf()->range()->cnt() > TypeFunc::Parms) {
1038     const Type* ret_type = tf()->range()->field_at(TypeFunc::Parms);
1039     Node*       ret_phi  = _gvn.transform( _exits.argument(0) );
1040     if (!_exits.control()->is_top() && _gvn.type(ret_phi)->empty()) {
1041       // If the type we set for the ret_phi in build_exits() is too optimistic and
1042       // the ret_phi is top now, there's an extremely small chance that it may be due to class
1043       // loading.  It could also be due to an error, so mark this method as not compilable because
1044       // otherwise this could lead to an infinite compile loop.
1045       // In any case, this code path is rarely (and never in my testing) reached.
1046       C->record_method_not_compilable("Can't determine return type.");
1047       return;
1048     }
1049     if (ret_type->isa_int()) {
1050       BasicType ret_bt = method()->return_type()->basic_type();
1051       ret_phi = mask_int_value(ret_phi, ret_bt, &_gvn);
1052     }
1053     _exits.push_node(ret_type->basic_type(), ret_phi);
1054   }
1055 
1056   // Note:  Logic for creating and optimizing the ReturnNode is in Compile.
1057 
1058   // Unlock along the exceptional paths.
1059   // This is done late so that we can common up equivalent exceptions
1060   // (e.g., null checks) arising from multiple points within this method.
1061   // See GraphKit::add_exception_state, which performs the commoning.
1062   bool do_synch = method()->is_synchronized() && GenerateSynchronizationCode;
1063 
1064   // record exit from a method if compiled while Dtrace is turned on.
1065   if (do_synch || C->env()->dtrace_method_probes() || _replaced_nodes_for_exceptions) {
1066     // First move the exception list out of _exits:
1067     GraphKit kit(_exits.transfer_exceptions_into_jvms());
1068     SafePointNode* normal_map = kit.map();  // keep this guy safe
1069     // Now re-collect the exceptions into _exits:
1070     SafePointNode* ex_map;
1071     while ((ex_map = kit.pop_exception_state()) != NULL) {
1072       Node* ex_oop = kit.use_exception_state(ex_map);
1073       // Force the exiting JVM state to have this method at InvocationEntryBci.
1074       // The exiting JVM state is otherwise a copy of the calling JVMS.
1075       JVMState* caller = kit.jvms();
1076       JVMState* ex_jvms = caller->clone_shallow(C);
1077       ex_jvms->bind_map(kit.clone_map());
1078       ex_jvms->set_bci(   InvocationEntryBci);
1079       kit.set_jvms(ex_jvms);
1080       if (do_synch) {
1081         // Add on the synchronized-method box/object combo
1082         kit.map()->push_monitor(_synch_lock);
1083         // Unlock!
1084         kit.shared_unlock(_synch_lock->box_node(), _synch_lock->obj_node());
1085       }
1086       if (C->env()->dtrace_method_probes()) {
1087         kit.make_dtrace_method_exit(method());
1088       }
1089       if (_replaced_nodes_for_exceptions) {
1090         kit.map()->apply_replaced_nodes(_new_idx);
1091       }
1092       // Done with exception-path processing.
1093       ex_map = kit.make_exception_state(ex_oop);
1094       assert(ex_jvms->same_calls_as(ex_map->jvms()), "sanity");
1095       // Pop the last vestige of this method:
1096       caller->clone_shallow(C)->bind_map(ex_map);
1097       _exits.push_exception_state(ex_map);
1098     }
1099     assert(_exits.map() == normal_map, "keep the same return state");
1100   }
1101 
1102   {
1103     // Capture very early exceptions (receiver null checks) from caller JVMS
1104     GraphKit caller(_caller);
1105     SafePointNode* ex_map;
1106     while ((ex_map = caller.pop_exception_state()) != NULL) {
1107       _exits.add_exception_state(ex_map);
1108     }
1109   }
1110   _exits.map()->apply_replaced_nodes(_new_idx);
1111 }
1112 
1113 //-----------------------------create_entry_map-------------------------------
1114 // Initialize our parser map to contain the types at method entry.
1115 // For OSR, the map contains a single RawPtr parameter.
1116 // Initial monitor locking for sync. methods is performed by do_method_entry.
1117 SafePointNode* Parse::create_entry_map() {
1118   // Check for really stupid bail-out cases.
1119   uint len = TypeFunc::Parms + method()->max_locals() + method()->max_stack();
1120   if (len >= 32760) {
1121     C->record_method_not_compilable("too many local variables");
1122     return NULL;
1123   }
1124 
1125   // clear current replaced nodes that are of no use from here on (map was cloned in build_exits).
1126   _caller->map()->delete_replaced_nodes();
1127 
1128   // If this is an inlined method, we may have to do a receiver null check.
1129   if (_caller->has_method() && is_normal_parse() && !method()->is_static()) {
1130     GraphKit kit(_caller);
1131     kit.null_check_receiver_before_call(method());
1132     _caller = kit.transfer_exceptions_into_jvms();
1133     if (kit.stopped()) {
1134       _exits.add_exception_states_from(_caller);
1135       _exits.set_jvms(_caller);
1136       return NULL;
1137     }
1138   }
1139 
1140   assert(method() != NULL, "parser must have a method");
1141 
1142   // Create an initial safepoint to hold JVM state during parsing
1143   JVMState* jvms = new (C) JVMState(method(), _caller->has_method() ? _caller : NULL);
1144   set_map(new SafePointNode(len, jvms));
1145   jvms->set_map(map());
1146   record_for_igvn(map());
1147   assert(jvms->endoff() == len, "correct jvms sizing");
1148 
1149   SafePointNode* inmap = _caller->map();
1150   assert(inmap != NULL, "must have inmap");
1151   // In case of null check on receiver above
1152   map()->transfer_replaced_nodes_from(inmap, _new_idx);
1153 
1154   uint i;
1155 
1156   // Pass thru the predefined input parameters.
1157   for (i = 0; i < TypeFunc::Parms; i++) {
1158     map()->init_req(i, inmap->in(i));
1159   }
1160 
1161   if (depth() == 1) {
1162     assert(map()->memory()->Opcode() == Op_Parm, "");
1163     // Insert the memory aliasing node
1164     set_all_memory(reset_memory());
1165   }
1166   assert(merged_memory(), "");
1167 
1168   // Now add the locals which are initially bound to arguments:
1169   uint arg_size = tf()->domain()->cnt();
1170   ensure_stack(arg_size - TypeFunc::Parms);  // OSR methods have funny args
1171   for (i = TypeFunc::Parms; i < arg_size; i++) {
1172     map()->init_req(i, inmap->argument(_caller, i - TypeFunc::Parms));
1173   }
1174 
1175   // Clear out the rest of the map (locals and stack)
1176   for (i = arg_size; i < len; i++) {
1177     map()->init_req(i, top());
1178   }
1179 
1180   SafePointNode* entry_map = stop();
1181   return entry_map;
1182 }
1183 
1184 //-----------------------------do_method_entry--------------------------------
1185 // Emit any code needed in the pseudo-block before BCI zero.
1186 // The main thing to do is lock the receiver of a synchronized method.
1187 void Parse::do_method_entry() {
1188   set_parse_bci(InvocationEntryBci); // Pseudo-BCP
1189   set_sp(0);                         // Java Stack Pointer
1190 
1191   NOT_PRODUCT( count_compiled_calls(true/*at_method_entry*/, false/*is_inline*/); )
1192 
1193   if (C->env()->dtrace_method_probes()) {
1194     make_dtrace_method_entry(method());
1195   }
1196 
1197 #ifdef ASSERT
1198   // Narrow receiver type when it is too broad for the method being parsed.
1199   if (!method()->is_static()) {
1200     ciInstanceKlass* callee_holder = method()->holder();
1201     const Type* holder_type = TypeInstPtr::make(TypePtr::BotPTR, callee_holder);
1202 
1203     Node* receiver_obj = local(0);
1204     const TypeInstPtr* receiver_type = _gvn.type(receiver_obj)->isa_instptr();
1205 
1206     if (receiver_type != NULL && !receiver_type->higher_equal(holder_type)) {
1207       // Receiver should always be a subtype of callee holder.
1208       // But, since C2 type system doesn't properly track interfaces,
1209       // the invariant can't be expressed in the type system for default methods.
1210       // Example: for unrelated C <: I and D <: I, (C `meet` D) = Object </: I.
1211       assert(callee_holder->is_interface(), "missing subtype check");
1212 
1213       // Perform dynamic receiver subtype check against callee holder class w/ a halt on failure.
1214       Node* holder_klass = _gvn.makecon(TypeKlassPtr::make(callee_holder));
1215       Node* not_subtype_ctrl = gen_subtype_check(receiver_obj, holder_klass);
1216       assert(!stopped(), "not a subtype");
1217 
1218       Node* halt = _gvn.transform(new HaltNode(not_subtype_ctrl, frameptr(), "failed receiver subtype check"));
1219       C->root()->add_req(halt);
1220     }
1221   }
1222 #endif // ASSERT
1223 
1224   // If the method is synchronized, we need to construct a lock node, attach
1225   // it to the Start node, and pin it there.
1226   if (method()->is_synchronized()) {
1227     // Insert a FastLockNode right after the Start which takes as arguments
1228     // the current thread pointer, the "this" pointer & the address of the
1229     // stack slot pair used for the lock.  The "this" pointer is a projection
1230     // off the start node, but the locking spot has to be constructed by
1231     // creating a ConLNode of 0, and boxing it with a BoxLockNode.  The BoxLockNode
1232     // becomes the second argument to the FastLockNode call.  The
1233     // FastLockNode becomes the new control parent to pin it to the start.
1234 
1235     // Setup Object Pointer
1236     Node *lock_obj = NULL;
1237     if (method()->is_static()) {
1238       ciInstance* mirror = _method->holder()->java_mirror();
1239       const TypeInstPtr *t_lock = TypeInstPtr::make(mirror);
1240       lock_obj = makecon(t_lock);
1241     } else {                  // Else pass the "this" pointer,
1242       lock_obj = local(0);    // which is Parm0 from StartNode
1243     }
1244     // Clear out dead values from the debug info.
1245     kill_dead_locals();
1246     // Build the FastLockNode
1247     _synch_lock = shared_lock(lock_obj);
1248   }
1249 
1250   // Feed profiling data for parameters to the type system so it can
1251   // propagate it as speculative types
1252   record_profiled_parameters_for_speculation();
1253 }
1254 
1255 //------------------------------init_blocks------------------------------------
1256 // Initialize our parser map to contain the types/monitors at method entry.
1257 void Parse::init_blocks() {
1258   // Create the blocks.
1259   _block_count = flow()->block_count();
1260   _blocks = NEW_RESOURCE_ARRAY(Block, _block_count);
1261 
1262   // Initialize the structs.
1263   for (int rpo = 0; rpo < block_count(); rpo++) {
1264     Block* block = rpo_at(rpo);
1265     new(block) Block(this, rpo);
1266   }
1267 
1268   // Collect predecessor and successor information.
1269   for (int rpo = 0; rpo < block_count(); rpo++) {
1270     Block* block = rpo_at(rpo);
1271     block->init_graph(this);
1272   }
1273 }
1274 
1275 //-------------------------------init_node-------------------------------------
1276 Parse::Block::Block(Parse* outer, int rpo) : _live_locals() {
1277   _flow = outer->flow()->rpo_at(rpo);
1278   _pred_count = 0;
1279   _preds_parsed = 0;
1280   _count = 0;
1281   _is_parsed = false;
1282   _is_handler = false;
1283   _has_merged_backedge = false;
1284   _start_map = NULL;
1285   _has_predicates = false;
1286   _num_successors = 0;
1287   _all_successors = 0;
1288   _successors = NULL;
1289   assert(pred_count() == 0 && preds_parsed() == 0, "sanity");
1290   assert(!(is_merged() || is_parsed() || is_handler() || has_merged_backedge()), "sanity");
1291   assert(_live_locals.size() == 0, "sanity");
1292 
1293   // entry point has additional predecessor
1294   if (flow()->is_start())  _pred_count++;
1295   assert(flow()->is_start() == (this == outer->start_block()), "");
1296 }
1297 
1298 //-------------------------------init_graph------------------------------------
1299 void Parse::Block::init_graph(Parse* outer) {
1300   // Create the successor list for this parser block.
1301   GrowableArray<ciTypeFlow::Block*>* tfs = flow()->successors();
1302   GrowableArray<ciTypeFlow::Block*>* tfe = flow()->exceptions();
1303   int ns = tfs->length();
1304   int ne = tfe->length();
1305   _num_successors = ns;
1306   _all_successors = ns+ne;
1307   _successors = (ns+ne == 0) ? NULL : NEW_RESOURCE_ARRAY(Block*, ns+ne);
1308   int p = 0;
1309   for (int i = 0; i < ns+ne; i++) {
1310     ciTypeFlow::Block* tf2 = (i < ns) ? tfs->at(i) : tfe->at(i-ns);
1311     Block* block2 = outer->rpo_at(tf2->rpo());
1312     _successors[i] = block2;
1313 
1314     // Accumulate pred info for the other block, too.
1315     // Note: We also need to set _pred_count for exception blocks since they could
1316     // also have normal predecessors (reached without athrow by an explicit jump).
1317     // This also means that next_path_num can be called along exception paths.
1318     block2->_pred_count++;
1319     if (i >= ns) {
1320       block2->_is_handler = true;
1321     }
1322 
1323     #ifdef ASSERT
1324     // A block's successors must be distinguishable by BCI.
1325     // That is, no bytecode is allowed to branch to two different
1326     // clones of the same code location.
1327     for (int j = 0; j < i; j++) {
1328       Block* block1 = _successors[j];
1329       if (block1 == block2)  continue;  // duplicates are OK
1330       assert(block1->start() != block2->start(), "successors have unique bcis");
1331     }
1332     #endif
1333   }
1334 }
1335 
1336 //---------------------------successor_for_bci---------------------------------
1337 Parse::Block* Parse::Block::successor_for_bci(int bci) {
1338   for (int i = 0; i < all_successors(); i++) {
1339     Block* block2 = successor_at(i);
1340     if (block2->start() == bci)  return block2;
1341   }
1342   // We can actually reach here if ciTypeFlow traps out a block
1343   // due to an unloaded class, and concurrently with compilation the
1344   // class is then loaded, so that a later phase of the parser is
1345   // able to see more of the bytecode CFG.  Or, the flow pass and
1346   // the parser can have a minor difference of opinion about executability
1347   // of bytecodes.  For example, "obj.field = null" is executable even
1348   // if the field's type is an unloaded class; the flow pass used to
1349   // make a trap for such code.
1350   return NULL;
1351 }
1352 
1353 
1354 //-----------------------------stack_type_at-----------------------------------
1355 const Type* Parse::Block::stack_type_at(int i) const {
1356   return get_type(flow()->stack_type_at(i));
1357 }
1358 
1359 
1360 //-----------------------------local_type_at-----------------------------------
1361 const Type* Parse::Block::local_type_at(int i) const {
1362   // Make dead locals fall to bottom.
1363   if (_live_locals.size() == 0) {
1364     MethodLivenessResult live_locals = flow()->outer()->method()->liveness_at_bci(start());
1365     // This bitmap can be zero length if we saw a breakpoint.
1366     // In such cases, pretend they are all live.
1367     ((Block*)this)->_live_locals = live_locals;
1368   }
1369   if (_live_locals.size() > 0 && !_live_locals.at(i))
1370     return Type::BOTTOM;
1371 
1372   return get_type(flow()->local_type_at(i));
1373 }
1374 
1375 
1376 #ifndef PRODUCT
1377 
1378 //----------------------------name_for_bc--------------------------------------
1379 // helper method for BytecodeParseHistogram
1380 static const char* name_for_bc(int i) {
1381   return Bytecodes::is_defined(i) ? Bytecodes::name(Bytecodes::cast(i)) : "xxxunusedxxx";
1382 }
1383 
1384 //----------------------------BytecodeParseHistogram------------------------------------
1385 Parse::BytecodeParseHistogram::BytecodeParseHistogram(Parse *p, Compile *c) {
1386   _parser   = p;
1387   _compiler = c;
1388   if( ! _initialized ) { _initialized = true; reset(); }
1389 }
1390 
1391 //----------------------------current_count------------------------------------
1392 int Parse::BytecodeParseHistogram::current_count(BPHType bph_type) {
1393   switch( bph_type ) {
1394   case BPH_transforms: { return _parser->gvn().made_progress(); }
1395   case BPH_values:     { return _parser->gvn().made_new_values(); }
1396   default: { ShouldNotReachHere(); return 0; }
1397   }
1398 }
1399 
1400 //----------------------------initialized--------------------------------------
1401 bool Parse::BytecodeParseHistogram::initialized() { return _initialized; }
1402 
1403 //----------------------------reset--------------------------------------------
1404 void Parse::BytecodeParseHistogram::reset() {
1405   int i = Bytecodes::number_of_codes;
1406   while (i-- > 0) { _bytecodes_parsed[i] = 0; _nodes_constructed[i] = 0; _nodes_transformed[i] = 0; _new_values[i] = 0; }
1407 }
1408 
1409 //----------------------------set_initial_state--------------------------------
1410 // Record info when starting to parse one bytecode
1411 void Parse::BytecodeParseHistogram::set_initial_state( Bytecodes::Code bc ) {
1412   if( PrintParseStatistics && !_parser->is_osr_parse() ) {
1413     _initial_bytecode    = bc;
1414     _initial_node_count  = _compiler->unique();
1415     _initial_transforms  = current_count(BPH_transforms);
1416     _initial_values      = current_count(BPH_values);
1417   }
1418 }
1419 
1420 //----------------------------record_change--------------------------------
1421 // Record results of parsing one bytecode
1422 void Parse::BytecodeParseHistogram::record_change() {
1423   if( PrintParseStatistics && !_parser->is_osr_parse() ) {
1424     ++_bytecodes_parsed[_initial_bytecode];
1425     _nodes_constructed [_initial_bytecode] += (_compiler->unique() - _initial_node_count);
1426     _nodes_transformed [_initial_bytecode] += (current_count(BPH_transforms) - _initial_transforms);
1427     _new_values        [_initial_bytecode] += (current_count(BPH_values)     - _initial_values);
1428   }
1429 }
1430 
1431 
1432 //----------------------------print--------------------------------------------
1433 void Parse::BytecodeParseHistogram::print(float cutoff) {
1434   ResourceMark rm;
1435   // print profile
1436   int total  = 0;
1437   int i      = 0;
1438   for( i = 0; i < Bytecodes::number_of_codes; ++i ) { total += _bytecodes_parsed[i]; }
1439   int abs_sum = 0;
1440   tty->cr();   //0123456789012345678901234567890123456789012345678901234567890123456789
1441   tty->print_cr("Histogram of %d parsed bytecodes:", total);
1442   if( total == 0 ) { return; }
1443   tty->cr();
1444   tty->print_cr("absolute:  count of compiled bytecodes of this type");
1445   tty->print_cr("relative:  percentage contribution to compiled nodes");
1446   tty->print_cr("nodes   :  Average number of nodes constructed per bytecode");
1447   tty->print_cr("rnodes  :  Significance towards total nodes constructed, (nodes*relative)");
1448   tty->print_cr("transforms: Average amount of transform progress per bytecode compiled");
1449   tty->print_cr("values  :  Average number of node values improved per bytecode");
1450   tty->print_cr("name    :  Bytecode name");
1451   tty->cr();
1452   tty->print_cr("  absolute  relative   nodes  rnodes  transforms  values   name");
1453   tty->print_cr("----------------------------------------------------------------------");
1454   while (--i > 0) {
1455     int       abs = _bytecodes_parsed[i];
1456     float     rel = abs * 100.0F / total;
1457     float   nodes = _bytecodes_parsed[i] == 0 ? 0 : (1.0F * _nodes_constructed[i])/_bytecodes_parsed[i];
1458     float  rnodes = _bytecodes_parsed[i] == 0 ? 0 :  rel * nodes;
1459     float  xforms = _bytecodes_parsed[i] == 0 ? 0 : (1.0F * _nodes_transformed[i])/_bytecodes_parsed[i];
1460     float  values = _bytecodes_parsed[i] == 0 ? 0 : (1.0F * _new_values       [i])/_bytecodes_parsed[i];
1461     if (cutoff <= rel) {
1462       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));
1463       abs_sum += abs;
1464     }
1465   }
1466   tty->print_cr("----------------------------------------------------------------------");
1467   float rel_sum = abs_sum * 100.0F / total;
1468   tty->print_cr("%10d  %7.2f%%    (cutoff = %.2f%%)", abs_sum, rel_sum, cutoff);
1469   tty->print_cr("----------------------------------------------------------------------");
1470   tty->cr();
1471 }
1472 #endif
1473 
1474 //----------------------------load_state_from----------------------------------
1475 // Load block/map/sp.  But not do not touch iter/bci.
1476 void Parse::load_state_from(Block* block) {
1477   set_block(block);
1478   // load the block's JVM state:
1479   set_map(block->start_map());
1480   set_sp( block->start_sp());
1481 }
1482 
1483 
1484 //-----------------------------record_state------------------------------------
1485 void Parse::Block::record_state(Parse* p) {
1486   assert(!is_merged(), "can only record state once, on 1st inflow");
1487   assert(start_sp() == p->sp(), "stack pointer must agree with ciTypeFlow");
1488   set_start_map(p->stop());
1489 }
1490 
1491 
1492 //------------------------------do_one_block-----------------------------------
1493 void Parse::do_one_block() {
1494   if (TraceOptoParse) {
1495     Block *b = block();
1496     int ns = b->num_successors();
1497     int nt = b->all_successors();
1498 
1499     tty->print("Parsing block #%d at bci [%d,%d), successors: ",
1500                   block()->rpo(), block()->start(), block()->limit());
1501     for (int i = 0; i < nt; i++) {
1502       tty->print((( i < ns) ? " %d" : " %d(e)"), b->successor_at(i)->rpo());
1503     }
1504     if (b->is_loop_head()) tty->print("  lphd");
1505     tty->cr();
1506   }
1507 
1508   assert(block()->is_merged(), "must be merged before being parsed");
1509   block()->mark_parsed();
1510 
1511   // Set iterator to start of block.
1512   iter().reset_to_bci(block()->start());
1513 
1514   CompileLog* log = C->log();
1515 
1516   // Parse bytecodes
1517   while (!stopped() && !failing()) {
1518     iter().next();
1519 
1520     // Learn the current bci from the iterator:
1521     set_parse_bci(iter().cur_bci());
1522 
1523     if (bci() == block()->limit()) {
1524       // Do not walk into the next block until directed by do_all_blocks.
1525       merge(bci());
1526       break;
1527     }
1528     assert(bci() < block()->limit(), "bci still in block");
1529 
1530     if (log != NULL) {
1531       // Output an optional context marker, to help place actions
1532       // that occur during parsing of this BC.  If there is no log
1533       // output until the next context string, this context string
1534       // will be silently ignored.
1535       log->set_context("bc code='%d' bci='%d'", (int)bc(), bci());
1536     }
1537 
1538     if (block()->has_trap_at(bci())) {
1539       // We must respect the flow pass's traps, because it will refuse
1540       // to produce successors for trapping blocks.
1541       int trap_index = block()->flow()->trap_index();
1542       assert(trap_index != 0, "trap index must be valid");
1543       uncommon_trap(trap_index);
1544       break;
1545     }
1546 
1547     NOT_PRODUCT( parse_histogram()->set_initial_state(bc()); );
1548 
1549 #ifdef ASSERT
1550     int pre_bc_sp = sp();
1551     int inputs, depth;
1552     bool have_se = !stopped() && compute_stack_effects(inputs, depth);
1553     assert(!have_se || pre_bc_sp >= inputs, "have enough stack to execute this BC: pre_bc_sp=%d, inputs=%d", pre_bc_sp, inputs);
1554 #endif //ASSERT
1555 
1556     do_one_bytecode();
1557 
1558     assert(!have_se || stopped() || failing() || (sp() - pre_bc_sp) == depth,
1559            "incorrect depth prediction: sp=%d, pre_bc_sp=%d, depth=%d", sp(), pre_bc_sp, depth);
1560 
1561     do_exceptions();
1562 
1563     NOT_PRODUCT( parse_histogram()->record_change(); );
1564 
1565     if (log != NULL)
1566       log->clear_context();  // skip marker if nothing was printed
1567 
1568     // Fall into next bytecode.  Each bytecode normally has 1 sequential
1569     // successor which is typically made ready by visiting this bytecode.
1570     // If the successor has several predecessors, then it is a merge
1571     // point, starts a new basic block, and is handled like other basic blocks.
1572   }
1573 }
1574 
1575 
1576 //------------------------------merge------------------------------------------
1577 void Parse::set_parse_bci(int bci) {
1578   set_bci(bci);
1579   Node_Notes* nn = C->default_node_notes();
1580   if (nn == NULL)  return;
1581 
1582   // Collect debug info for inlined calls unless -XX:-DebugInlinedCalls.
1583   if (!DebugInlinedCalls && depth() > 1) {
1584     return;
1585   }
1586 
1587   // Update the JVMS annotation, if present.
1588   JVMState* jvms = nn->jvms();
1589   if (jvms != NULL && jvms->bci() != bci) {
1590     // Update the JVMS.
1591     jvms = jvms->clone_shallow(C);
1592     jvms->set_bci(bci);
1593     nn->set_jvms(jvms);
1594   }
1595 }
1596 
1597 //------------------------------merge------------------------------------------
1598 // Merge the current mapping into the basic block starting at bci
1599 void Parse::merge(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(), "our arrival must be expected");
1603   int pnum = target->next_path_num();
1604   merge_common(target, pnum);
1605 }
1606 
1607 //-------------------------merge_new_path--------------------------------------
1608 // Merge the current mapping into the basic block, using a new path
1609 void Parse::merge_new_path(int target_bci) {
1610   Block* target = successor_for_bci(target_bci);
1611   if (target == NULL) { handle_missing_successor(target_bci); return; }
1612   assert(!target->is_ready(), "new path into frozen graph");
1613   int pnum = target->add_new_path();
1614   merge_common(target, pnum);
1615 }
1616 
1617 //-------------------------merge_exception-------------------------------------
1618 // Merge the current mapping into the basic block starting at bci
1619 // The ex_oop must be pushed on the stack, unlike throw_to_exit.
1620 void Parse::merge_exception(int target_bci) {
1621 #ifdef ASSERT
1622   if (target_bci < bci()) {
1623     C->set_exception_backedge();
1624   }
1625 #endif
1626   assert(sp() == 1, "must have only the throw exception on the stack");
1627   Block* target = successor_for_bci(target_bci);
1628   if (target == NULL) { handle_missing_successor(target_bci); return; }
1629   assert(target->is_handler(), "exceptions are handled by special blocks");
1630   int pnum = target->add_new_path();
1631   merge_common(target, pnum);
1632 }
1633 
1634 //--------------------handle_missing_successor---------------------------------
1635 void Parse::handle_missing_successor(int target_bci) {
1636 #ifndef PRODUCT
1637   Block* b = block();
1638   int trap_bci = b->flow()->has_trap()? b->flow()->trap_bci(): -1;
1639   tty->print_cr("### Missing successor at bci:%d for block #%d (trap_bci:%d)", target_bci, b->rpo(), trap_bci);
1640 #endif
1641   ShouldNotReachHere();
1642 }
1643 
1644 //--------------------------merge_common---------------------------------------
1645 void Parse::merge_common(Parse::Block* target, int pnum) {
1646   if (TraceOptoParse) {
1647     tty->print("Merging state at block #%d bci:%d", target->rpo(), target->start());
1648   }
1649 
1650   // Zap extra stack slots to top
1651   assert(sp() == target->start_sp(), "");
1652   clean_stack(sp());
1653 
1654   if (!target->is_merged()) {   // No prior mapping at this bci
1655     if (TraceOptoParse) { tty->print(" with empty state");  }
1656 
1657     // If this path is dead, do not bother capturing it as a merge.
1658     // It is "as if" we had 1 fewer predecessors from the beginning.
1659     if (stopped()) {
1660       if (TraceOptoParse)  tty->print_cr(", but path is dead and doesn't count");
1661       return;
1662     }
1663 
1664     // Make a region if we know there are multiple or unpredictable inputs.
1665     // (Also, if this is a plain fall-through, we might see another region,
1666     // which must not be allowed into this block's map.)
1667     if (pnum > PhiNode::Input         // Known multiple inputs.
1668         || target->is_handler()       // These have unpredictable inputs.
1669         || target->is_loop_head()     // Known multiple inputs
1670         || control()->is_Region()) {  // We must hide this guy.
1671 
1672       int current_bci = bci();
1673       set_parse_bci(target->start()); // Set target bci
1674       if (target->is_SEL_head()) {
1675         DEBUG_ONLY( target->mark_merged_backedge(block()); )
1676         if (target->start() == 0) {
1677           // Add loop predicate for the special case when
1678           // there are backbranches to the method entry.
1679           add_empty_predicates();
1680         }
1681       }
1682       // Add a Region to start the new basic block.  Phis will be added
1683       // later lazily.
1684       int edges = target->pred_count();
1685       if (edges < pnum)  edges = pnum;  // might be a new path!
1686       RegionNode *r = new RegionNode(edges+1);
1687       gvn().set_type(r, Type::CONTROL);
1688       record_for_igvn(r);
1689       // zap all inputs to NULL for debugging (done in Node(uint) constructor)
1690       // for (int j = 1; j < edges+1; j++) { r->init_req(j, NULL); }
1691       r->init_req(pnum, control());
1692       set_control(r);
1693       set_parse_bci(current_bci); // Restore bci
1694     }
1695 
1696     // Convert the existing Parser mapping into a mapping at this bci.
1697     store_state_to(target);
1698     assert(target->is_merged(), "do not come here twice");
1699 
1700   } else {                      // Prior mapping at this bci
1701     if (TraceOptoParse) {  tty->print(" with previous state"); }
1702 #ifdef ASSERT
1703     if (target->is_SEL_head()) {
1704       target->mark_merged_backedge(block());
1705     }
1706 #endif
1707     // We must not manufacture more phis if the target is already parsed.
1708     bool nophi = target->is_parsed();
1709 
1710     SafePointNode* newin = map();// Hang on to incoming mapping
1711     Block* save_block = block(); // Hang on to incoming block;
1712     load_state_from(target);    // Get prior mapping
1713 
1714     assert(newin->jvms()->locoff() == jvms()->locoff(), "JVMS layouts agree");
1715     assert(newin->jvms()->stkoff() == jvms()->stkoff(), "JVMS layouts agree");
1716     assert(newin->jvms()->monoff() == jvms()->monoff(), "JVMS layouts agree");
1717     assert(newin->jvms()->endoff() == jvms()->endoff(), "JVMS layouts agree");
1718 
1719     // Iterate over my current mapping and the old mapping.
1720     // Where different, insert Phi functions.
1721     // Use any existing Phi functions.
1722     assert(control()->is_Region(), "must be merging to a region");
1723     RegionNode* r = control()->as_Region();
1724 
1725     // Compute where to merge into
1726     // Merge incoming control path
1727     r->init_req(pnum, newin->control());
1728 
1729     if (pnum == 1) {            // Last merge for this Region?
1730       if (!block()->flow()->is_irreducible_entry()) {
1731         Node* result = _gvn.transform_no_reclaim(r);
1732         if (r != result && TraceOptoParse) {
1733           tty->print_cr("Block #%d replace %d with %d", block()->rpo(), r->_idx, result->_idx);
1734         }
1735       }
1736       record_for_igvn(r);
1737     }
1738 
1739     // Update all the non-control inputs to map:
1740     assert(TypeFunc::Parms == newin->jvms()->locoff(), "parser map should contain only youngest jvms");
1741     bool check_elide_phi = target->is_SEL_backedge(save_block);
1742     for (uint j = 1; j < newin->req(); j++) {
1743       Node* m = map()->in(j);   // Current state of target.
1744       Node* n = newin->in(j);   // Incoming change to target state.
1745       PhiNode* phi;
1746       if (m->is_Phi() && m->as_Phi()->region() == r)
1747         phi = m->as_Phi();
1748       else
1749         phi = NULL;
1750       if (m != n) {             // Different; must merge
1751         switch (j) {
1752         // Frame pointer and Return Address never changes
1753         case TypeFunc::FramePtr:// Drop m, use the original value
1754         case TypeFunc::ReturnAdr:
1755           break;
1756         case TypeFunc::Memory:  // Merge inputs to the MergeMem node
1757           assert(phi == NULL, "the merge contains phis, not vice versa");
1758           merge_memory_edges(n->as_MergeMem(), pnum, nophi);
1759           continue;
1760         default:                // All normal stuff
1761           if (phi == NULL) {
1762             const JVMState* jvms = map()->jvms();
1763             if (EliminateNestedLocks &&
1764                 jvms->is_mon(j) && jvms->is_monitor_box(j)) {
1765               // BoxLock nodes are not commoning.
1766               // Use old BoxLock node as merged box.
1767               assert(newin->jvms()->is_monitor_box(j), "sanity");
1768               // This assert also tests that nodes are BoxLock.
1769               assert(BoxLockNode::same_slot(n, m), "sanity");
1770               C->gvn_replace_by(n, m);
1771             } else if (!check_elide_phi || !target->can_elide_SEL_phi(j)) {
1772               phi = ensure_phi(j, nophi);
1773             }
1774           }
1775           break;
1776         }
1777       }
1778       // At this point, n might be top if:
1779       //  - there is no phi (because TypeFlow detected a conflict), or
1780       //  - the corresponding control edges is top (a dead incoming path)
1781       // It is a bug if we create a phi which sees a garbage value on a live path.
1782 
1783       if (phi != NULL) {
1784         assert(n != top() || r->in(pnum) == top(), "live value must not be garbage");
1785         assert(phi->region() == r, "");
1786         phi->set_req(pnum, n);  // Then add 'n' to the merge
1787         if (pnum == PhiNode::Input) {
1788           // Last merge for this Phi.
1789           // So far, Phis have had a reasonable type from ciTypeFlow.
1790           // Now _gvn will join that with the meet of current inputs.
1791           // BOTTOM is never permissible here, 'cause pessimistically
1792           // Phis of pointers cannot lose the basic pointer type.
1793           debug_only(const Type* bt1 = phi->bottom_type());
1794           assert(bt1 != Type::BOTTOM, "should not be building conflict phis");
1795           map()->set_req(j, _gvn.transform_no_reclaim(phi));
1796           debug_only(const Type* bt2 = phi->bottom_type());
1797           assert(bt2->higher_equal_speculative(bt1), "must be consistent with type-flow");
1798           record_for_igvn(phi);
1799         }
1800       }
1801     } // End of for all values to be merged
1802 
1803     if (pnum == PhiNode::Input &&
1804         !r->in(0)) {         // The occasional useless Region
1805       assert(control() == r, "");
1806       set_control(r->nonnull_req());
1807     }
1808 
1809     map()->merge_replaced_nodes_with(newin);
1810 
1811     // newin has been subsumed into the lazy merge, and is now dead.
1812     set_block(save_block);
1813 
1814     stop();                     // done with this guy, for now
1815   }
1816 
1817   if (TraceOptoParse) {
1818     tty->print_cr(" on path %d", pnum);
1819   }
1820 
1821   // Done with this parser state.
1822   assert(stopped(), "");
1823 }
1824 
1825 
1826 //--------------------------merge_memory_edges---------------------------------
1827 void Parse::merge_memory_edges(MergeMemNode* n, int pnum, bool nophi) {
1828   // (nophi means we must not create phis, because we already parsed here)
1829   assert(n != NULL, "");
1830   // Merge the inputs to the MergeMems
1831   MergeMemNode* m = merged_memory();
1832 
1833   assert(control()->is_Region(), "must be merging to a region");
1834   RegionNode* r = control()->as_Region();
1835 
1836   PhiNode* base = NULL;
1837   MergeMemNode* remerge = NULL;
1838   for (MergeMemStream mms(m, n); mms.next_non_empty2(); ) {
1839     Node *p = mms.force_memory();
1840     Node *q = mms.memory2();
1841     if (mms.is_empty() && nophi) {
1842       // Trouble:  No new splits allowed after a loop body is parsed.
1843       // Instead, wire the new split into a MergeMem on the backedge.
1844       // The optimizer will sort it out, slicing the phi.
1845       if (remerge == NULL) {
1846         guarantee(base != NULL, "");
1847         assert(base->in(0) != NULL, "should not be xformed away");
1848         remerge = MergeMemNode::make(base->in(pnum));
1849         gvn().set_type(remerge, Type::MEMORY);
1850         base->set_req(pnum, remerge);
1851       }
1852       remerge->set_memory_at(mms.alias_idx(), q);
1853       continue;
1854     }
1855     assert(!q->is_MergeMem(), "");
1856     PhiNode* phi;
1857     if (p != q) {
1858       phi = ensure_memory_phi(mms.alias_idx(), nophi);
1859     } else {
1860       if (p->is_Phi() && p->as_Phi()->region() == r)
1861         phi = p->as_Phi();
1862       else
1863         phi = NULL;
1864     }
1865     // Insert q into local phi
1866     if (phi != NULL) {
1867       assert(phi->region() == r, "");
1868       p = phi;
1869       phi->set_req(pnum, q);
1870       if (mms.at_base_memory()) {
1871         base = phi;  // delay transforming it
1872       } else if (pnum == 1) {
1873         record_for_igvn(phi);
1874         p = _gvn.transform_no_reclaim(phi);
1875       }
1876       mms.set_memory(p);// store back through the iterator
1877     }
1878   }
1879   // Transform base last, in case we must fiddle with remerging.
1880   if (base != NULL && pnum == 1) {
1881     record_for_igvn(base);
1882     m->set_base_memory( _gvn.transform_no_reclaim(base) );
1883   }
1884 }
1885 
1886 
1887 //------------------------ensure_phis_everywhere-------------------------------
1888 void Parse::ensure_phis_everywhere() {
1889   ensure_phi(TypeFunc::I_O);
1890 
1891   // Ensure a phi on all currently known memories.
1892   for (MergeMemStream mms(merged_memory()); mms.next_non_empty(); ) {
1893     ensure_memory_phi(mms.alias_idx());
1894     debug_only(mms.set_memory());  // keep the iterator happy
1895   }
1896 
1897   // Note:  This is our only chance to create phis for memory slices.
1898   // If we miss a slice that crops up later, it will have to be
1899   // merged into the base-memory phi that we are building here.
1900   // Later, the optimizer will comb out the knot, and build separate
1901   // phi-loops for each memory slice that matters.
1902 
1903   // Monitors must nest nicely and not get confused amongst themselves.
1904   // Phi-ify everything up to the monitors, though.
1905   uint monoff = map()->jvms()->monoff();
1906   uint nof_monitors = map()->jvms()->nof_monitors();
1907 
1908   assert(TypeFunc::Parms == map()->jvms()->locoff(), "parser map should contain only youngest jvms");
1909   bool check_elide_phi = block()->is_SEL_head();
1910   for (uint i = TypeFunc::Parms; i < monoff; i++) {
1911     if (!check_elide_phi || !block()->can_elide_SEL_phi(i)) {
1912       ensure_phi(i);
1913     }
1914   }
1915 
1916   // Even monitors need Phis, though they are well-structured.
1917   // This is true for OSR methods, and also for the rare cases where
1918   // a monitor object is the subject of a replace_in_map operation.
1919   // See bugs 4426707 and 5043395.
1920   for (uint m = 0; m < nof_monitors; m++) {
1921     ensure_phi(map()->jvms()->monitor_obj_offset(m));
1922   }
1923 }
1924 
1925 
1926 //-----------------------------add_new_path------------------------------------
1927 // Add a previously unaccounted predecessor to this block.
1928 int Parse::Block::add_new_path() {
1929   // If there is no map, return the lowest unused path number.
1930   if (!is_merged())  return pred_count()+1;  // there will be a map shortly
1931 
1932   SafePointNode* map = start_map();
1933   if (!map->control()->is_Region())
1934     return pred_count()+1;  // there may be a region some day
1935   RegionNode* r = map->control()->as_Region();
1936 
1937   // Add new path to the region.
1938   uint pnum = r->req();
1939   r->add_req(NULL);
1940 
1941   for (uint i = 1; i < map->req(); i++) {
1942     Node* n = map->in(i);
1943     if (i == TypeFunc::Memory) {
1944       // Ensure a phi on all currently known memories.
1945       for (MergeMemStream mms(n->as_MergeMem()); mms.next_non_empty(); ) {
1946         Node* phi = mms.memory();
1947         if (phi->is_Phi() && phi->as_Phi()->region() == r) {
1948           assert(phi->req() == pnum, "must be same size as region");
1949           phi->add_req(NULL);
1950         }
1951       }
1952     } else {
1953       if (n->is_Phi() && n->as_Phi()->region() == r) {
1954         assert(n->req() == pnum, "must be same size as region");
1955         n->add_req(NULL);
1956       }
1957     }
1958   }
1959 
1960   return pnum;
1961 }
1962 
1963 //------------------------------ensure_phi-------------------------------------
1964 // Turn the idx'th entry of the current map into a Phi
1965 PhiNode *Parse::ensure_phi(int idx, bool nocreate) {
1966   SafePointNode* map = this->map();
1967   Node* region = map->control();
1968   assert(region->is_Region(), "");
1969 
1970   Node* o = map->in(idx);
1971   assert(o != NULL, "");
1972 
1973   if (o == top())  return NULL; // TOP always merges into TOP
1974 
1975   if (o->is_Phi() && o->as_Phi()->region() == region) {
1976     return o->as_Phi();
1977   }
1978 
1979   // Now use a Phi here for merging
1980   assert(!nocreate, "Cannot build a phi for a block already parsed.");
1981   const JVMState* jvms = map->jvms();
1982   const Type* t = NULL;
1983   if (jvms->is_loc(idx)) {
1984     t = block()->local_type_at(idx - jvms->locoff());
1985   } else if (jvms->is_stk(idx)) {
1986     t = block()->stack_type_at(idx - jvms->stkoff());
1987   } else if (jvms->is_mon(idx)) {
1988     assert(!jvms->is_monitor_box(idx), "no phis for boxes");
1989     t = TypeInstPtr::BOTTOM; // this is sufficient for a lock object
1990   } else if ((uint)idx < TypeFunc::Parms) {
1991     t = o->bottom_type();  // Type::RETURN_ADDRESS or such-like.
1992   } else {
1993     assert(false, "no type information for this phi");
1994   }
1995 
1996   // If the type falls to bottom, then this must be a local that
1997   // is mixing ints and oops or some such.  Forcing it to top
1998   // makes it go dead.
1999   if (t == Type::BOTTOM) {
2000     map->set_req(idx, top());
2001     return NULL;
2002   }
2003 
2004   // Do not create phis for top either.
2005   // A top on a non-null control flow must be an unused even after the.phi.
2006   if (t == Type::TOP || t == Type::HALF) {
2007     map->set_req(idx, top());
2008     return NULL;
2009   }
2010 
2011   PhiNode* phi = PhiNode::make(region, o, t);
2012   gvn().set_type(phi, t);
2013   if (C->do_escape_analysis()) record_for_igvn(phi);
2014   map->set_req(idx, phi);
2015   return phi;
2016 }
2017 
2018 //--------------------------ensure_memory_phi----------------------------------
2019 // Turn the idx'th slice of the current memory into a Phi
2020 PhiNode *Parse::ensure_memory_phi(int idx, bool nocreate) {
2021   MergeMemNode* mem = merged_memory();
2022   Node* region = control();
2023   assert(region->is_Region(), "");
2024 
2025   Node *o = (idx == Compile::AliasIdxBot)? mem->base_memory(): mem->memory_at(idx);
2026   assert(o != NULL && o != top(), "");
2027 
2028   PhiNode* phi;
2029   if (o->is_Phi() && o->as_Phi()->region() == region) {
2030     phi = o->as_Phi();
2031     if (phi == mem->base_memory() && idx >= Compile::AliasIdxRaw) {
2032       // clone the shared base memory phi to make a new memory split
2033       assert(!nocreate, "Cannot build a phi for a block already parsed.");
2034       const Type* t = phi->bottom_type();
2035       const TypePtr* adr_type = C->get_adr_type(idx);
2036       phi = phi->slice_memory(adr_type);
2037       gvn().set_type(phi, t);
2038     }
2039     return phi;
2040   }
2041 
2042   // Now use a Phi here for merging
2043   assert(!nocreate, "Cannot build a phi for a block already parsed.");
2044   const Type* t = o->bottom_type();
2045   const TypePtr* adr_type = C->get_adr_type(idx);
2046   phi = PhiNode::make(region, o, t, adr_type);
2047   gvn().set_type(phi, t);
2048   if (idx == Compile::AliasIdxBot)
2049     mem->set_base_memory(phi);
2050   else
2051     mem->set_memory_at(idx, phi);
2052   return phi;
2053 }
2054 
2055 //------------------------------call_register_finalizer-----------------------
2056 // Check the klass of the receiver and call register_finalizer if the
2057 // class need finalization.
2058 void Parse::call_register_finalizer() {
2059   Node* receiver = local(0);
2060   assert(receiver != NULL && receiver->bottom_type()->isa_instptr() != NULL,
2061          "must have non-null instance type");
2062 
2063   const TypeInstPtr *tinst = receiver->bottom_type()->isa_instptr();
2064   if (tinst != NULL && tinst->is_loaded() && !tinst->klass_is_exact()) {
2065     // The type isn't known exactly so see if CHA tells us anything.
2066     ciInstanceKlass* ik = tinst->instance_klass();
2067     if (!Dependencies::has_finalizable_subclass(ik)) {
2068       // No finalizable subclasses so skip the dynamic check.
2069       C->dependencies()->assert_has_no_finalizable_subclasses(ik);
2070       return;
2071     }
2072   }
2073 
2074   // Insert a dynamic test for whether the instance needs
2075   // finalization.  In general this will fold up since the concrete
2076   // class is often visible so the access flags are constant.
2077   Node* klass_addr = basic_plus_adr( receiver, receiver, oopDesc::klass_offset_in_bytes() );
2078   Node* klass = _gvn.transform(LoadKlassNode::make(_gvn, NULL, immutable_memory(), klass_addr, TypeInstPtr::KLASS));
2079 
2080   Node* access_flags_addr = basic_plus_adr(klass, klass, in_bytes(Klass::access_flags_offset()));
2081   Node* access_flags = make_load(NULL, access_flags_addr, TypeInt::INT, T_INT, MemNode::unordered);
2082 
2083   Node* mask  = _gvn.transform(new AndINode(access_flags, intcon(JVM_ACC_HAS_FINALIZER)));
2084   Node* check = _gvn.transform(new CmpINode(mask, intcon(0)));
2085   Node* test  = _gvn.transform(new BoolNode(check, BoolTest::ne));
2086 
2087   IfNode* iff = create_and_map_if(control(), test, PROB_MAX, COUNT_UNKNOWN);
2088 
2089   RegionNode* result_rgn = new RegionNode(3);
2090   record_for_igvn(result_rgn);
2091 
2092   Node *skip_register = _gvn.transform(new IfFalseNode(iff));
2093   result_rgn->init_req(1, skip_register);
2094 
2095   Node *needs_register = _gvn.transform(new IfTrueNode(iff));
2096   set_control(needs_register);
2097   if (stopped()) {
2098     // There is no slow path.
2099     result_rgn->init_req(2, top());
2100   } else {
2101     Node *call = make_runtime_call(RC_NO_LEAF,
2102                                    OptoRuntime::register_finalizer_Type(),
2103                                    OptoRuntime::register_finalizer_Java(),
2104                                    NULL, TypePtr::BOTTOM,
2105                                    receiver);
2106     make_slow_call_ex(call, env()->Throwable_klass(), true);
2107 
2108     Node* fast_io  = call->in(TypeFunc::I_O);
2109     Node* fast_mem = call->in(TypeFunc::Memory);
2110     // These two phis are pre-filled with copies of of the fast IO and Memory
2111     Node* io_phi   = PhiNode::make(result_rgn, fast_io,  Type::ABIO);
2112     Node* mem_phi  = PhiNode::make(result_rgn, fast_mem, Type::MEMORY, TypePtr::BOTTOM);
2113 
2114     result_rgn->init_req(2, control());
2115     io_phi    ->init_req(2, i_o());
2116     mem_phi   ->init_req(2, reset_memory());
2117 
2118     set_all_memory( _gvn.transform(mem_phi) );
2119     set_i_o(        _gvn.transform(io_phi) );
2120   }
2121 
2122   set_control( _gvn.transform(result_rgn) );
2123 }
2124 
2125 // Add check to deoptimize once holder klass is fully initialized.
2126 void Parse::clinit_deopt() {
2127   assert(C->has_method(), "only for normal compilations");
2128   assert(depth() == 1, "only for main compiled method");
2129   assert(is_normal_parse(), "no barrier needed on osr entry");
2130   assert(!method()->holder()->is_not_initialized(), "initialization should have been started");
2131 
2132   set_parse_bci(0);
2133 
2134   Node* holder = makecon(TypeKlassPtr::make(method()->holder()));
2135   guard_klass_being_initialized(holder);
2136 }
2137 
2138 // Add check to deoptimize if RTM state is not ProfileRTM
2139 void Parse::rtm_deopt() {
2140 #if INCLUDE_RTM_OPT
2141   if (C->profile_rtm()) {
2142     assert(C->has_method(), "only for normal compilations");
2143     assert(!C->method()->method_data()->is_empty(), "MDO is needed to record RTM state");
2144     assert(depth() == 1, "generate check only for main compiled method");
2145 
2146     // Set starting bci for uncommon trap.
2147     set_parse_bci(is_osr_parse() ? osr_bci() : 0);
2148 
2149     // Load the rtm_state from the MethodData.
2150     const TypePtr* adr_type = TypeMetadataPtr::make(C->method()->method_data());
2151     Node* mdo = makecon(adr_type);
2152     int offset = MethodData::rtm_state_offset_in_bytes();
2153     Node* adr_node = basic_plus_adr(mdo, mdo, offset);
2154     Node* rtm_state = make_load(control(), adr_node, TypeInt::INT, T_INT, adr_type, MemNode::unordered);
2155 
2156     // Separate Load from Cmp by Opaque.
2157     // In expand_macro_nodes() it will be replaced either
2158     // with this load when there are locks in the code
2159     // or with ProfileRTM (cmp->in(2)) otherwise so that
2160     // the check will fold.
2161     Node* profile_state = makecon(TypeInt::make(ProfileRTM));
2162     Node* opq   = _gvn.transform( new Opaque3Node(C, rtm_state, Opaque3Node::RTM_OPT) );
2163     Node* chk   = _gvn.transform( new CmpINode(opq, profile_state) );
2164     Node* tst   = _gvn.transform( new BoolNode(chk, BoolTest::eq) );
2165     // Branch to failure if state was changed
2166     { BuildCutout unless(this, tst, PROB_ALWAYS);
2167       uncommon_trap(Deoptimization::Reason_rtm_state_change,
2168                     Deoptimization::Action_make_not_entrant);
2169     }
2170   }
2171 #endif
2172 }
2173 
2174 //------------------------------return_current---------------------------------
2175 // Append current _map to _exit_return
2176 void Parse::return_current(Node* value) {
2177   if (RegisterFinalizersAtInit &&
2178       method()->intrinsic_id() == vmIntrinsics::_Object_init) {
2179     call_register_finalizer();
2180   }
2181 
2182   // Do not set_parse_bci, so that return goo is credited to the return insn.
2183   set_bci(InvocationEntryBci);
2184   if (method()->is_synchronized() && GenerateSynchronizationCode) {
2185     shared_unlock(_synch_lock->box_node(), _synch_lock->obj_node());
2186   }
2187   if (C->env()->dtrace_method_probes()) {
2188     make_dtrace_method_exit(method());
2189   }
2190   SafePointNode* exit_return = _exits.map();
2191   exit_return->in( TypeFunc::Control  )->add_req( control() );
2192   exit_return->in( TypeFunc::I_O      )->add_req( i_o    () );
2193   Node *mem = exit_return->in( TypeFunc::Memory   );
2194   for (MergeMemStream mms(mem->as_MergeMem(), merged_memory()); mms.next_non_empty2(); ) {
2195     if (mms.is_empty()) {
2196       // get a copy of the base memory, and patch just this one input
2197       const TypePtr* adr_type = mms.adr_type(C);
2198       Node* phi = mms.force_memory()->as_Phi()->slice_memory(adr_type);
2199       assert(phi->as_Phi()->region() == mms.base_memory()->in(0), "");
2200       gvn().set_type_bottom(phi);
2201       phi->del_req(phi->req()-1);  // prepare to re-patch
2202       mms.set_memory(phi);
2203     }
2204     mms.memory()->add_req(mms.memory2());
2205   }
2206 
2207   // frame pointer is always same, already captured
2208   if (value != NULL) {
2209     // If returning oops to an interface-return, there is a silent free
2210     // cast from oop to interface allowed by the Verifier.  Make it explicit
2211     // here.
2212     Node* phi = _exits.argument(0);
2213     const TypeInstPtr *tr = phi->bottom_type()->isa_instptr();
2214     if (tr && tr->is_loaded() &&
2215         tr->is_interface()) {
2216       const TypeInstPtr *tp = value->bottom_type()->isa_instptr();
2217       if (tp && tp->is_loaded() &&
2218           !tp->is_interface()) {
2219         // sharpen the type eagerly; this eases certain assert checking
2220         if (tp->higher_equal(TypeInstPtr::NOTNULL))
2221           tr = tr->join_speculative(TypeInstPtr::NOTNULL)->is_instptr();
2222         value = _gvn.transform(new CheckCastPPNode(0, value, tr));
2223       }
2224     } else {
2225       // Also handle returns of oop-arrays to an arrays-of-interface return
2226       const TypeInstPtr* phi_tip;
2227       const TypeInstPtr* val_tip;
2228       Type::get_arrays_base_elements(phi->bottom_type(), value->bottom_type(), &phi_tip, &val_tip);
2229       if (phi_tip != NULL && phi_tip->is_loaded() && phi_tip->is_interface() &&
2230           val_tip != NULL && val_tip->is_loaded() && !val_tip->is_interface()) {
2231         value = _gvn.transform(new CheckCastPPNode(0, value, phi->bottom_type()));
2232       }
2233     }
2234     phi->add_req(value);
2235   }
2236 
2237   if (_first_return) {
2238     _exits.map()->transfer_replaced_nodes_from(map(), _new_idx);
2239     _first_return = false;
2240   } else {
2241     _exits.map()->merge_replaced_nodes_with(map());
2242   }
2243 
2244   stop_and_kill_map();          // This CFG path dies here
2245 }
2246 
2247 
2248 //------------------------------add_safepoint----------------------------------
2249 void Parse::add_safepoint() {
2250   uint parms = TypeFunc::Parms+1;
2251 
2252   // Clear out dead values from the debug info.
2253   kill_dead_locals();
2254 
2255   // Clone the JVM State
2256   SafePointNode *sfpnt = new SafePointNode(parms, NULL);
2257 
2258   // Capture memory state BEFORE a SafePoint.  Since we can block at a
2259   // SafePoint we need our GC state to be safe; i.e. we need all our current
2260   // write barriers (card marks) to not float down after the SafePoint so we
2261   // must read raw memory.  Likewise we need all oop stores to match the card
2262   // marks.  If deopt can happen, we need ALL stores (we need the correct JVM
2263   // state on a deopt).
2264 
2265   // We do not need to WRITE the memory state after a SafePoint.  The control
2266   // edge will keep card-marks and oop-stores from floating up from below a
2267   // SafePoint and our true dependency added here will keep them from floating
2268   // down below a SafePoint.
2269 
2270   // Clone the current memory state
2271   Node* mem = MergeMemNode::make(map()->memory());
2272 
2273   mem = _gvn.transform(mem);
2274 
2275   // Pass control through the safepoint
2276   sfpnt->init_req(TypeFunc::Control  , control());
2277   // Fix edges normally used by a call
2278   sfpnt->init_req(TypeFunc::I_O      , top() );
2279   sfpnt->init_req(TypeFunc::Memory   , mem   );
2280   sfpnt->init_req(TypeFunc::ReturnAdr, top() );
2281   sfpnt->init_req(TypeFunc::FramePtr , top() );
2282 
2283   // Create a node for the polling address
2284   Node *polladr;
2285   Node *thread = _gvn.transform(new ThreadLocalNode());
2286   Node *polling_page_load_addr = _gvn.transform(basic_plus_adr(top(), thread, in_bytes(JavaThread::polling_page_offset())));
2287   polladr = make_load(control(), polling_page_load_addr, TypeRawPtr::BOTTOM, T_ADDRESS, Compile::AliasIdxRaw, MemNode::unordered);
2288   sfpnt->init_req(TypeFunc::Parms+0, _gvn.transform(polladr));
2289 
2290   // Fix up the JVM State edges
2291   add_safepoint_edges(sfpnt);
2292   Node *transformed_sfpnt = _gvn.transform(sfpnt);
2293   set_control(transformed_sfpnt);
2294 
2295   // Provide an edge from root to safepoint.  This makes the safepoint
2296   // appear useful until the parse has completed.
2297   if (transformed_sfpnt->is_SafePoint()) {
2298     assert(C->root() != NULL, "Expect parse is still valid");
2299     C->root()->add_prec(transformed_sfpnt);
2300   }
2301 }
2302 
2303 #ifndef PRODUCT
2304 //------------------------show_parse_info--------------------------------------
2305 void Parse::show_parse_info() {
2306   InlineTree* ilt = NULL;
2307   if (C->ilt() != NULL) {
2308     JVMState* caller_jvms = is_osr_parse() ? caller()->caller() : caller();
2309     ilt = InlineTree::find_subtree_from_root(C->ilt(), caller_jvms, method());
2310   }
2311   if (PrintCompilation && Verbose) {
2312     if (depth() == 1) {
2313       if( ilt->count_inlines() ) {
2314         tty->print("    __inlined %d (%d bytes)", ilt->count_inlines(),
2315                      ilt->count_inline_bcs());
2316         tty->cr();
2317       }
2318     } else {
2319       if (method()->is_synchronized())         tty->print("s");
2320       if (method()->has_exception_handlers())  tty->print("!");
2321       // Check this is not the final compiled version
2322       if (C->trap_can_recompile()) {
2323         tty->print("-");
2324       } else {
2325         tty->print(" ");
2326       }
2327       method()->print_short_name();
2328       if (is_osr_parse()) {
2329         tty->print(" @ %d", osr_bci());
2330       }
2331       tty->print(" (%d bytes)",method()->code_size());
2332       if (ilt->count_inlines()) {
2333         tty->print(" __inlined %d (%d bytes)", ilt->count_inlines(),
2334                    ilt->count_inline_bcs());
2335       }
2336       tty->cr();
2337     }
2338   }
2339   if (PrintOpto && (depth() == 1 || PrintOptoInlining)) {
2340     // Print that we succeeded; suppress this message on the first osr parse.
2341 
2342     if (method()->is_synchronized())         tty->print("s");
2343     if (method()->has_exception_handlers())  tty->print("!");
2344     // Check this is not the final compiled version
2345     if (C->trap_can_recompile() && depth() == 1) {
2346       tty->print("-");
2347     } else {
2348       tty->print(" ");
2349     }
2350     if( depth() != 1 ) { tty->print("   "); }  // missing compile count
2351     for (int i = 1; i < depth(); ++i) { tty->print("  "); }
2352     method()->print_short_name();
2353     if (is_osr_parse()) {
2354       tty->print(" @ %d", osr_bci());
2355     }
2356     if (ilt->caller_bci() != -1) {
2357       tty->print(" @ %d", ilt->caller_bci());
2358     }
2359     tty->print(" (%d bytes)",method()->code_size());
2360     if (ilt->count_inlines()) {
2361       tty->print(" __inlined %d (%d bytes)", ilt->count_inlines(),
2362                  ilt->count_inline_bcs());
2363     }
2364     tty->cr();
2365   }
2366 }
2367 
2368 
2369 //------------------------------dump-------------------------------------------
2370 // Dump information associated with the bytecodes of current _method
2371 void Parse::dump() {
2372   if( method() != NULL ) {
2373     // Iterate over bytecodes
2374     ciBytecodeStream iter(method());
2375     for( Bytecodes::Code bc = iter.next(); bc != ciBytecodeStream::EOBC() ; bc = iter.next() ) {
2376       dump_bci( iter.cur_bci() );
2377       tty->cr();
2378     }
2379   }
2380 }
2381 
2382 // Dump information associated with a byte code index, 'bci'
2383 void Parse::dump_bci(int bci) {
2384   // Output info on merge-points, cloning, and within _jsr..._ret
2385   // NYI
2386   tty->print(" bci:%d", bci);
2387 }
2388 
2389 #endif