1 /*
   2  * Copyright (c) 1997, 2013, 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 "oops/method.hpp"
  29 #include "opto/addnode.hpp"
  30 #include "opto/idealGraphPrinter.hpp"
  31 #include "opto/locknode.hpp"
  32 #include "opto/memnode.hpp"
  33 #include "opto/parse.hpp"
  34 #include "opto/rootnode.hpp"
  35 #include "opto/runtime.hpp"
  36 #include "runtime/arguments.hpp"
  37 #include "runtime/handles.inline.hpp"
  38 #include "runtime/sharedRuntime.hpp"
  39 #include "utilities/copy.hpp"
  40 
  41 // Static array so we can figure out which bytecodes stop us from compiling
  42 // the most. Some of the non-static variables are needed in bytecodeInfo.cpp
  43 // and eventually should be encapsulated in a proper class (gri 8/18/98).
  44 
  45 int nodes_created              = 0;
  46 int methods_parsed             = 0;
  47 int methods_seen               = 0;
  48 int blocks_parsed              = 0;
  49 int blocks_seen                = 0;
  50 
  51 int explicit_null_checks_inserted = 0;
  52 int explicit_null_checks_elided   = 0;
  53 int all_null_checks_found         = 0, implicit_null_checks              = 0;
  54 int implicit_null_throws          = 0;
  55 
  56 int reclaim_idx  = 0;
  57 int reclaim_in   = 0;
  58 int reclaim_node = 0;
  59 
  60 #ifndef PRODUCT
  61 bool Parse::BytecodeParseHistogram::_initialized = false;
  62 uint Parse::BytecodeParseHistogram::_bytecodes_parsed [Bytecodes::number_of_codes];
  63 uint Parse::BytecodeParseHistogram::_nodes_constructed[Bytecodes::number_of_codes];
  64 uint Parse::BytecodeParseHistogram::_nodes_transformed[Bytecodes::number_of_codes];
  65 uint Parse::BytecodeParseHistogram::_new_values       [Bytecodes::number_of_codes];
  66 #endif
  67 
  68 //------------------------------print_statistics-------------------------------
  69 #ifndef PRODUCT
  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   tty->print_cr("Blocks parsed: %d  Blocks seen: %d", blocks_parsed, blocks_seen);
  78 
  79   if( explicit_null_checks_inserted )
  80     tty->print_cr("%d original NULL checks - %d elided (%2d%%); optimizer leaves %d,", explicit_null_checks_inserted, explicit_null_checks_elided, (100*explicit_null_checks_elided)/explicit_null_checks_inserted, all_null_checks_found);
  81   if( all_null_checks_found )
  82     tty->print_cr("%d made implicit (%2d%%)", implicit_null_checks,
  83                   (100*implicit_null_checks)/all_null_checks_found);
  84   if( implicit_null_throws )
  85     tty->print_cr("%d implicit null exceptions at runtime",
  86                   implicit_null_throws);
  87 
  88   if( PrintParseStatistics && BytecodeParseHistogram::initialized() ) {
  89     BytecodeParseHistogram::print();
  90   }
  91 }
  92 #endif
  93 
  94 //------------------------------ON STACK REPLACEMENT---------------------------
  95 
  96 // Construct a node which can be used to get incoming state for
  97 // on stack replacement.
  98 Node *Parse::fetch_interpreter_state(int index,
  99                                      BasicType bt,
 100                                      Node *local_addrs,
 101                                      Node *local_addrs_base) {
 102   Node *mem = memory(Compile::AliasIdxRaw);
 103   Node *adr = basic_plus_adr( local_addrs_base, local_addrs, -index*wordSize );
 104   Node *ctl = control();
 105 
 106   // Very similar to LoadNode::make, except we handle un-aligned longs and
 107   // doubles on Sparc.  Intel can handle them just fine directly.
 108   Node *l;
 109   switch (bt) {                // Signature is flattened
 110   case T_INT:     l = new (C) LoadINode(ctl, mem, adr, TypeRawPtr::BOTTOM, TypeInt::INT,        MemNode::unordered); break;
 111   case T_FLOAT:   l = new (C) LoadFNode(ctl, mem, adr, TypeRawPtr::BOTTOM, Type::FLOAT,         MemNode::unordered); break;
 112   case T_ADDRESS: l = new (C) LoadPNode(ctl, mem, adr, TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM,  MemNode::unordered); break;
 113   case T_OBJECT:  l = new (C) LoadPNode(ctl, mem, adr, TypeRawPtr::BOTTOM, TypeInstPtr::BOTTOM, MemNode::unordered); break;
 114   case T_LONG:
 115   case T_DOUBLE: {
 116     // Since arguments are in reverse order, the argument address 'adr'
 117     // refers to the back half of the long/double.  Recompute adr.
 118     adr = basic_plus_adr(local_addrs_base, local_addrs, -(index+1)*wordSize);
 119     if (Matcher::misaligned_doubles_ok) {
 120       l = (bt == T_DOUBLE)
 121         ? (Node*)new (C) LoadDNode(ctl, mem, adr, TypeRawPtr::BOTTOM, Type::DOUBLE, MemNode::unordered)
 122         : (Node*)new (C) LoadLNode(ctl, mem, adr, TypeRawPtr::BOTTOM, TypeLong::LONG, MemNode::unordered);
 123     } else {
 124       l = (bt == T_DOUBLE)
 125         ? (Node*)new (C) LoadD_unalignedNode(ctl, mem, adr, TypeRawPtr::BOTTOM, MemNode::unordered)
 126         : (Node*)new (C) LoadL_unalignedNode(ctl, mem, adr, TypeRawPtr::BOTTOM, MemNode::unordered);
 127     }
 128     break;
 129   }
 130   default: ShouldNotReachHere();
 131   }
 132   return _gvn.transform(l);
 133 }
 134 
 135 // Helper routine to prevent the interpreter from handing
 136 // unexpected typestate to an OSR method.
 137 // The Node l is a value newly dug out of the interpreter frame.
 138 // The type is the type predicted by ciTypeFlow.  Note that it is
 139 // not a general type, but can only come from Type::get_typeflow_type.
 140 // The safepoint is a map which will feed an uncommon trap.
 141 Node* Parse::check_interpreter_type(Node* l, const Type* type,
 142                                     SafePointNode* &bad_type_exit) {
 143 
 144   const TypeOopPtr* tp = type->isa_oopptr();
 145 
 146   // TypeFlow may assert null-ness if a type appears unloaded.
 147   if (type == TypePtr::NULL_PTR ||
 148       (tp != NULL && !tp->klass()->is_loaded())) {
 149     // Value must be null, not a real oop.
 150     Node* chk = _gvn.transform( new (C) CmpPNode(l, null()) );
 151     Node* tst = _gvn.transform( new (C) BoolNode(chk, BoolTest::eq) );
 152     IfNode* iff = create_and_map_if(control(), tst, PROB_MAX, COUNT_UNKNOWN);
 153     set_control(_gvn.transform( new (C) IfTrueNode(iff) ));
 154     Node* bad_type = _gvn.transform( new (C) IfFalseNode(iff) );
 155     bad_type_exit->control()->add_req(bad_type);
 156     l = null();
 157   }
 158 
 159   // Typeflow can also cut off paths from the CFG, based on
 160   // types which appear unloaded, or call sites which appear unlinked.
 161   // When paths are cut off, values at later merge points can rise
 162   // toward more specific classes.  Make sure these specific classes
 163   // are still in effect.
 164   if (tp != NULL && tp->klass() != C->env()->Object_klass()) {
 165     // TypeFlow asserted a specific object type.  Value must have that type.
 166     Node* bad_type_ctrl = NULL;
 167     l = gen_checkcast(l, makecon(TypeKlassPtr::make(tp->klass())), &bad_type_ctrl);
 168     bad_type_exit->control()->add_req(bad_type_ctrl);
 169   }
 170 
 171   BasicType bt_l = _gvn.type(l)->basic_type();
 172   BasicType bt_t = type->basic_type();
 173   assert(_gvn.type(l)->higher_equal(type), "must constrain OSR typestate");
 174   return l;
 175 }
 176 
 177 // Helper routine which sets up elements of the initial parser map when
 178 // performing a parse for on stack replacement.  Add values into map.
 179 // The only parameter contains the address of a interpreter arguments.
 180 void Parse::load_interpreter_state(Node* osr_buf) {
 181   int index;
 182   int max_locals = jvms()->loc_size();
 183   int max_stack  = jvms()->stk_size();
 184 
 185 
 186   // Mismatch between method and jvms can occur since map briefly held
 187   // an OSR entry state (which takes up one RawPtr word).
 188   assert(max_locals == method()->max_locals(), "sanity");
 189   assert(max_stack  >= method()->max_stack(),  "sanity");
 190   assert((int)jvms()->endoff() == TypeFunc::Parms + max_locals + max_stack, "sanity");
 191   assert((int)jvms()->endoff() == (int)map()->req(), "sanity");
 192 
 193   // Find the start block.
 194   Block* osr_block = start_block();
 195   assert(osr_block->start() == osr_bci(), "sanity");
 196 
 197   // Set initial BCI.
 198   set_parse_bci(osr_block->start());
 199 
 200   // Set initial stack depth.
 201   set_sp(osr_block->start_sp());
 202 
 203   // Check bailouts.  We currently do not perform on stack replacement
 204   // of loops in catch blocks or loops which branch with a non-empty stack.
 205   if (sp() != 0) {
 206     C->record_method_not_compilable("OSR starts with non-empty stack");
 207     return;
 208   }
 209   // Do not OSR inside finally clauses:
 210   if (osr_block->has_trap_at(osr_block->start())) {
 211     C->record_method_not_compilable("OSR starts with an immediate trap");
 212     return;
 213   }
 214 
 215   // Commute monitors from interpreter frame to compiler frame.
 216   assert(jvms()->monitor_depth() == 0, "should be no active locks at beginning of osr");
 217   int mcnt = osr_block->flow()->monitor_count();
 218   Node *monitors_addr = basic_plus_adr(osr_buf, osr_buf, (max_locals+mcnt*2-1)*wordSize);
 219   for (index = 0; index < mcnt; index++) {
 220     // Make a BoxLockNode for the monitor.
 221     Node *box = _gvn.transform(new (C) BoxLockNode(next_monitor()));
 222 
 223 
 224     // Displaced headers and locked objects are interleaved in the
 225     // temp OSR buffer.  We only copy the locked objects out here.
 226     // Fetch the locked object from the OSR temp buffer and copy to our fastlock node.
 227     Node *lock_object = fetch_interpreter_state(index*2, T_OBJECT, monitors_addr, osr_buf);
 228     // Try and copy the displaced header to the BoxNode
 229     Node *displaced_hdr = fetch_interpreter_state((index*2) + 1, T_ADDRESS, monitors_addr, osr_buf);
 230 
 231 
 232     store_to_memory(control(), box, displaced_hdr, T_ADDRESS, Compile::AliasIdxRaw, MemNode::unordered);
 233 
 234     // Build a bogus FastLockNode (no code will be generated) and push the
 235     // monitor into our debug info.
 236     const FastLockNode *flock = _gvn.transform(new (C) FastLockNode( 0, lock_object, box ))->as_FastLock();
 237     map()->push_monitor(flock);
 238 
 239     // If the lock is our method synchronization lock, tuck it away in
 240     // _sync_lock for return and rethrow exit paths.
 241     if (index == 0 && method()->is_synchronized()) {
 242       _synch_lock = flock;
 243     }
 244   }
 245 
 246   // Use the raw liveness computation to make sure that unexpected
 247   // values don't propagate into the OSR frame.
 248   MethodLivenessResult live_locals = method()->liveness_at_bci(osr_bci());
 249   if (!live_locals.is_valid()) {
 250     // Degenerate or breakpointed method.
 251     C->record_method_not_compilable("OSR in empty or breakpointed method");
 252     return;
 253   }
 254 
 255   // Extract the needed locals from the interpreter frame.
 256   Node *locals_addr = basic_plus_adr(osr_buf, osr_buf, (max_locals-1)*wordSize);
 257 
 258   // find all the locals that the interpreter thinks contain live oops
 259   const BitMap live_oops = method()->live_local_oops_at_bci(osr_bci());
 260   for (index = 0; index < max_locals; index++) {
 261 
 262     if (!live_locals.at(index)) {
 263       continue;
 264     }
 265 
 266     const Type *type = osr_block->local_type_at(index);
 267 
 268     if (type->isa_oopptr() != NULL) {
 269 
 270       // 6403625: Verify that the interpreter oopMap thinks that the oop is live
 271       // else we might load a stale oop if the MethodLiveness disagrees with the
 272       // result of the interpreter. If the interpreter says it is dead we agree
 273       // by making the value go to top.
 274       //
 275 
 276       if (!live_oops.at(index)) {
 277         if (C->log() != NULL) {
 278           C->log()->elem("OSR_mismatch local_index='%d'",index);
 279         }
 280         set_local(index, null());
 281         // and ignore it for the loads
 282         continue;
 283       }
 284     }
 285 
 286     // Filter out TOP, HALF, and BOTTOM.  (Cf. ensure_phi.)
 287     if (type == Type::TOP || type == Type::HALF) {
 288       continue;
 289     }
 290     // If the type falls to bottom, then this must be a local that
 291     // is mixing ints and oops or some such.  Forcing it to top
 292     // makes it go dead.
 293     if (type == Type::BOTTOM) {
 294       continue;
 295     }
 296     // Construct code to access the appropriate local.
 297     BasicType bt = type->basic_type();
 298     if (type == TypePtr::NULL_PTR) {
 299       // Ptr types are mixed together with T_ADDRESS but NULL is
 300       // really for T_OBJECT types so correct it.
 301       bt = T_OBJECT;
 302     }
 303     Node *value = fetch_interpreter_state(index, bt, locals_addr, osr_buf);
 304     set_local(index, value);
 305   }
 306 
 307   // Extract the needed stack entries from the interpreter frame.
 308   for (index = 0; index < sp(); index++) {
 309     const Type *type = osr_block->stack_type_at(index);
 310     if (type != Type::TOP) {
 311       // Currently the compiler bails out when attempting to on stack replace
 312       // at a bci with a non-empty stack.  We should not reach here.
 313       ShouldNotReachHere();
 314     }
 315   }
 316 
 317   // End the OSR migration
 318   make_runtime_call(RC_LEAF, OptoRuntime::osr_end_Type(),
 319                     CAST_FROM_FN_PTR(address, SharedRuntime::OSR_migration_end),
 320                     "OSR_migration_end", TypeRawPtr::BOTTOM,
 321                     osr_buf);
 322 
 323   // Now that the interpreter state is loaded, make sure it will match
 324   // at execution time what the compiler is expecting now:
 325   SafePointNode* bad_type_exit = clone_map();
 326   bad_type_exit->set_control(new (C) RegionNode(1));
 327 
 328   assert(osr_block->flow()->jsrs()->size() == 0, "should be no jsrs live at osr point");
 329   for (index = 0; index < max_locals; index++) {
 330     if (stopped())  break;
 331     Node* l = local(index);
 332     if (l->is_top())  continue;  // nothing here
 333     const Type *type = osr_block->local_type_at(index);
 334     if (type->isa_oopptr() != NULL) {
 335       if (!live_oops.at(index)) {
 336         // skip type check for dead oops
 337         continue;
 338       }
 339     }
 340     if (osr_block->flow()->local_type_at(index)->is_return_address()) {
 341       // In our current system it's illegal for jsr addresses to be
 342       // live into an OSR entry point because the compiler performs
 343       // inlining of jsrs.  ciTypeFlow has a bailout that detect this
 344       // case and aborts the compile if addresses are live into an OSR
 345       // entry point.  Because of that we can assume that any address
 346       // locals at the OSR entry point are dead.  Method liveness
 347       // isn't precise enought to figure out that they are dead in all
 348       // cases so simply skip checking address locals all
 349       // together. Any type check is guaranteed to fail since the
 350       // interpreter type is the result of a load which might have any
 351       // value and the expected type is a constant.
 352       continue;
 353     }
 354     set_local(index, check_interpreter_type(l, type, bad_type_exit));
 355   }
 356 
 357   for (index = 0; index < sp(); index++) {
 358     if (stopped())  break;
 359     Node* l = stack(index);
 360     if (l->is_top())  continue;  // nothing here
 361     const Type *type = osr_block->stack_type_at(index);
 362     set_stack(index, check_interpreter_type(l, type, bad_type_exit));
 363   }
 364 
 365   if (bad_type_exit->control()->req() > 1) {
 366     // Build an uncommon trap here, if any inputs can be unexpected.
 367     bad_type_exit->set_control(_gvn.transform( bad_type_exit->control() ));
 368     record_for_igvn(bad_type_exit->control());
 369     SafePointNode* types_are_good = map();
 370     set_map(bad_type_exit);
 371     // The unexpected type happens because a new edge is active
 372     // in the CFG, which typeflow had previously ignored.
 373     // E.g., Object x = coldAtFirst() && notReached()? "str": new Integer(123).
 374     // This x will be typed as Integer if notReached is not yet linked.
 375     // It could also happen due to a problem in ciTypeFlow analysis.
 376     uncommon_trap(Deoptimization::Reason_constraint,
 377                   Deoptimization::Action_reinterpret);
 378     set_map(types_are_good);
 379   }
 380 }
 381 
 382 //------------------------------Parse------------------------------------------
 383 // Main parser constructor.
 384 Parse::Parse(JVMState* caller, ciMethod* parse_method, float expected_uses, Parse* parent)
 385   : _exits(caller), _parent(parent)
 386 {
 387   // Init some variables
 388   _caller = caller;
 389   _method = parse_method;
 390   _expected_uses = expected_uses;
 391   _depth = 1 + (caller->has_method() ? caller->depth() : 0);
 392   _wrote_final = false;
 393   _wrote_volatile = false;
 394   _alloc_with_final = NULL;
 395   _entry_bci = InvocationEntryBci;
 396   _tf = NULL;
 397   _block = NULL;
 398   debug_only(_block_count = -1);
 399   debug_only(_blocks = (Block*)-1);
 400 #ifndef PRODUCT
 401   if (PrintCompilation || PrintOpto) {
 402     // Make sure I have an inline tree, so I can print messages about it.
 403     JVMState* ilt_caller = is_osr_parse() ? caller->caller() : caller;
 404     InlineTree::find_subtree_from_root(C->ilt(), ilt_caller, parse_method);
 405   }
 406   _max_switch_depth = 0;
 407   _est_switch_depth = 0;
 408 #endif
 409 
 410   _tf = TypeFunc::make(method());
 411   _iter.reset_to_method(method());
 412   _flow = method()->get_flow_analysis();
 413   if (_flow->failing()) {
 414     C->record_method_not_compilable_all_tiers(_flow->failure_reason());
 415   }
 416 
 417 #ifndef PRODUCT
 418   if (_flow->has_irreducible_entry()) {
 419     C->set_parsed_irreducible_loop(true);
 420   }
 421 #endif
 422 
 423   if (_expected_uses <= 0) {
 424     _prof_factor = 1;
 425   } else {
 426     float prof_total = parse_method->interpreter_invocation_count();
 427     if (prof_total <= _expected_uses) {
 428       _prof_factor = 1;
 429     } else {
 430       _prof_factor = _expected_uses / prof_total;
 431     }
 432   }
 433 
 434   CompileLog* log = C->log();
 435   if (log != NULL) {
 436     log->begin_head("parse method='%d' uses='%g'",
 437                     log->identify(parse_method), expected_uses);
 438     if (depth() == 1 && C->is_osr_compilation()) {
 439       log->print(" osr_bci='%d'", C->entry_bci());
 440     }
 441     log->stamp();
 442     log->end_head();
 443   }
 444 
 445   // Accumulate deoptimization counts.
 446   // (The range_check and store_check counts are checked elsewhere.)
 447   ciMethodData* md = method()->method_data();
 448   for (uint reason = 0; reason < md->trap_reason_limit(); reason++) {
 449     uint md_count = md->trap_count(reason);
 450     if (md_count != 0) {
 451       if (md_count == md->trap_count_limit())
 452         md_count += md->overflow_trap_count();
 453       uint total_count = C->trap_count(reason);
 454       uint old_count   = total_count;
 455       total_count += md_count;
 456       // Saturate the add if it overflows.
 457       if (total_count < old_count || total_count < md_count)
 458         total_count = (uint)-1;
 459       C->set_trap_count(reason, total_count);
 460       if (log != NULL)
 461         log->elem("observe trap='%s' count='%d' total='%d'",
 462                   Deoptimization::trap_reason_name(reason),
 463                   md_count, total_count);
 464     }
 465   }
 466   // Accumulate total sum of decompilations, also.
 467   C->set_decompile_count(C->decompile_count() + md->decompile_count());
 468 
 469   _count_invocations = C->do_count_invocations();
 470   _method_data_update = C->do_method_data_update();
 471 
 472   if (log != NULL && method()->has_exception_handlers()) {
 473     log->elem("observe that='has_exception_handlers'");
 474   }
 475 
 476   assert(method()->can_be_compiled(),       "Can not parse this method, cutout earlier");
 477   assert(method()->has_balanced_monitors(), "Can not parse unbalanced monitors, cutout earlier");
 478 
 479   // Always register dependence if JVMTI is enabled, because
 480   // either breakpoint setting or hotswapping of methods may
 481   // cause deoptimization.
 482   if (C->env()->jvmti_can_hotswap_or_post_breakpoint()) {
 483     C->dependencies()->assert_evol_method(method());
 484   }
 485 
 486   methods_seen++;
 487 
 488   // Do some special top-level things.
 489   if (depth() == 1 && C->is_osr_compilation()) {
 490     _entry_bci = C->entry_bci();
 491     _flow = method()->get_osr_flow_analysis(osr_bci());
 492     if (_flow->failing()) {
 493       C->record_method_not_compilable(_flow->failure_reason());
 494 #ifndef PRODUCT
 495       if (PrintOpto && (Verbose || WizardMode)) {
 496         tty->print_cr("OSR @%d type flow bailout: %s", _entry_bci, _flow->failure_reason());
 497         if (Verbose) {
 498           method()->print();
 499           method()->print_codes();
 500           _flow->print();
 501         }
 502       }
 503 #endif
 504     }
 505     _tf = C->tf();     // the OSR entry type is different
 506   }
 507 
 508 #ifdef ASSERT
 509   if (depth() == 1) {
 510     assert(C->is_osr_compilation() == this->is_osr_parse(), "OSR in sync");
 511     if (C->tf() != tf()) {
 512       MutexLockerEx ml(Compile_lock, Mutex::_no_safepoint_check_flag);
 513       assert(C->env()->system_dictionary_modification_counter_changed(),
 514              "Must invalidate if TypeFuncs differ");
 515     }
 516   } else {
 517     assert(!this->is_osr_parse(), "no recursive OSR");
 518   }
 519 #endif
 520 
 521   methods_parsed++;
 522 #ifndef PRODUCT
 523   // add method size here to guarantee that inlined methods are added too
 524   if (TimeCompiler)
 525     _total_bytes_compiled += method()->code_size();
 526 
 527   show_parse_info();
 528 #endif
 529 
 530   if (failing()) {
 531     if (log)  log->done("parse");
 532     return;
 533   }
 534 
 535   gvn().set_type(root(), root()->bottom_type());
 536   gvn().transform(top());
 537 
 538   // Import the results of the ciTypeFlow.
 539   init_blocks();
 540 
 541   // Merge point for all normal exits
 542   build_exits();
 543 
 544   // Setup the initial JVM state map.
 545   SafePointNode* entry_map = create_entry_map();
 546 
 547   // Check for bailouts during map initialization
 548   if (failing() || entry_map == NULL) {
 549     if (log)  log->done("parse");
 550     return;
 551   }
 552 
 553   Node_Notes* caller_nn = C->default_node_notes();
 554   // Collect debug info for inlined calls unless -XX:-DebugInlinedCalls.
 555   if (DebugInlinedCalls || depth() == 1) {
 556     C->set_default_node_notes(make_node_notes(caller_nn));
 557   }
 558 
 559   if (is_osr_parse()) {
 560     Node* osr_buf = entry_map->in(TypeFunc::Parms+0);
 561     entry_map->set_req(TypeFunc::Parms+0, top());
 562     set_map(entry_map);
 563     load_interpreter_state(osr_buf);
 564   } else {
 565     set_map(entry_map);
 566     do_method_entry();
 567   }
 568 
 569   // Check for bailouts during method entry.
 570   if (failing()) {
 571     if (log)  log->done("parse");
 572     C->set_default_node_notes(caller_nn);
 573     return;
 574   }
 575 
 576   entry_map = map();  // capture any changes performed by method setup code
 577   assert(jvms()->endoff() == map()->req(), "map matches JVMS layout");
 578 
 579   // We begin parsing as if we have just encountered a jump to the
 580   // method entry.
 581   Block* entry_block = start_block();
 582   assert(entry_block->start() == (is_osr_parse() ? osr_bci() : 0), "");
 583   set_map_clone(entry_map);
 584   merge_common(entry_block, entry_block->next_path_num());
 585 
 586 #ifndef PRODUCT
 587   BytecodeParseHistogram *parse_histogram_obj = new (C->env()->arena()) BytecodeParseHistogram(this, C);
 588   set_parse_histogram( parse_histogram_obj );
 589 #endif
 590 
 591   // Parse all the basic blocks.
 592   do_all_blocks();
 593 
 594   C->set_default_node_notes(caller_nn);
 595 
 596   // Check for bailouts during conversion to graph
 597   if (failing()) {
 598     if (log)  log->done("parse");
 599     return;
 600   }
 601 
 602   // Fix up all exiting control flow.
 603   set_map(entry_map);
 604   do_exits();
 605 
 606   if (log)  log->done("parse nodes='%d' live='%d' memory='%d'",
 607                       C->unique(), C->live_nodes(), C->node_arena()->used());
 608 }
 609 
 610 //---------------------------do_all_blocks-------------------------------------
 611 void Parse::do_all_blocks() {
 612   bool has_irreducible = flow()->has_irreducible_entry();
 613 
 614   // Walk over all blocks in Reverse Post-Order.
 615   while (true) {
 616     bool progress = false;
 617     for (int rpo = 0; rpo < block_count(); rpo++) {
 618       Block* block = rpo_at(rpo);
 619 
 620       if (block->is_parsed()) continue;
 621 
 622       if (!block->is_merged()) {
 623         // Dead block, no state reaches this block
 624         continue;
 625       }
 626 
 627       // Prepare to parse this block.
 628       load_state_from(block);
 629 
 630       if (stopped()) {
 631         // Block is dead.
 632         continue;
 633       }
 634 
 635       blocks_parsed++;
 636 
 637       progress = true;
 638       if (block->is_loop_head() || block->is_handler() || has_irreducible && !block->is_ready()) {
 639         // Not all preds have been parsed.  We must build phis everywhere.
 640         // (Note that dead locals do not get phis built, ever.)
 641         ensure_phis_everywhere();
 642 
 643         if (block->is_SEL_head() &&
 644             (UseLoopPredicate || LoopLimitCheck)) {
 645           // Add predicate to single entry (not irreducible) loop head.
 646           assert(!block->has_merged_backedge(), "only entry paths should be merged for now");
 647           // Need correct bci for predicate.
 648           // It is fine to set it here since do_one_block() will set it anyway.
 649           set_parse_bci(block->start());
 650           add_predicate();
 651           // Add new region for back branches.
 652           int edges = block->pred_count() - block->preds_parsed() + 1; // +1 for original region
 653           RegionNode *r = new (C) RegionNode(edges+1);
 654           _gvn.set_type(r, Type::CONTROL);
 655           record_for_igvn(r);
 656           r->init_req(edges, control());
 657           set_control(r);
 658           // Add new phis.
 659           ensure_phis_everywhere();
 660         }
 661 
 662         // Leave behind an undisturbed copy of the map, for future merges.
 663         set_map(clone_map());
 664       }
 665 
 666       if (control()->is_Region() && !block->is_loop_head() && !has_irreducible && !block->is_handler()) {
 667         // In the absence of irreducible loops, the Region and Phis
 668         // associated with a merge that doesn't involve a backedge can
 669         // be simplified now since the RPO parsing order guarantees
 670         // that any path which was supposed to reach here has already
 671         // been parsed or must be dead.
 672         Node* c = control();
 673         Node* result = _gvn.transform_no_reclaim(control());
 674         if (c != result && TraceOptoParse) {
 675           tty->print_cr("Block #%d replace %d with %d", block->rpo(), c->_idx, result->_idx);
 676         }
 677         if (result != top()) {
 678           record_for_igvn(result);
 679         }
 680       }
 681 
 682       // Parse the block.
 683       do_one_block();
 684 
 685       // Check for bailouts.
 686       if (failing())  return;
 687     }
 688 
 689     // with irreducible loops multiple passes might be necessary to parse everything
 690     if (!has_irreducible || !progress) {
 691       break;
 692     }
 693   }
 694 
 695   blocks_seen += block_count();
 696 
 697 #ifndef PRODUCT
 698   // Make sure there are no half-processed blocks remaining.
 699   // Every remaining unprocessed block is dead and may be ignored now.
 700   for (int rpo = 0; rpo < block_count(); rpo++) {
 701     Block* block = rpo_at(rpo);
 702     if (!block->is_parsed()) {
 703       if (TraceOptoParse) {
 704         tty->print_cr("Skipped dead block %d at bci:%d", rpo, block->start());
 705       }
 706       assert(!block->is_merged(), "no half-processed blocks");
 707     }
 708   }
 709 #endif
 710 }
 711 
 712 //-------------------------------build_exits----------------------------------
 713 // Build normal and exceptional exit merge points.
 714 void Parse::build_exits() {
 715   // make a clone of caller to prevent sharing of side-effects
 716   _exits.set_map(_exits.clone_map());
 717   _exits.clean_stack(_exits.sp());
 718   _exits.sync_jvms();
 719 
 720   RegionNode* region = new (C) RegionNode(1);
 721   record_for_igvn(region);
 722   gvn().set_type_bottom(region);
 723   _exits.set_control(region);
 724 
 725   // Note:  iophi and memphi are not transformed until do_exits.
 726   Node* iophi  = new (C) PhiNode(region, Type::ABIO);
 727   Node* memphi = new (C) PhiNode(region, Type::MEMORY, TypePtr::BOTTOM);
 728   gvn().set_type_bottom(iophi);
 729   gvn().set_type_bottom(memphi);
 730   _exits.set_i_o(iophi);
 731   _exits.set_all_memory(memphi);
 732 
 733   // Add a return value to the exit state.  (Do not push it yet.)
 734   if (tf()->range()->cnt() > TypeFunc::Parms) {
 735     const Type* ret_type = tf()->range()->field_at(TypeFunc::Parms);
 736     // Don't "bind" an unloaded return klass to the ret_phi. If the klass
 737     // becomes loaded during the subsequent parsing, the loaded and unloaded
 738     // types will not join when we transform and push in do_exits().
 739     const TypeOopPtr* ret_oop_type = ret_type->isa_oopptr();
 740     if (ret_oop_type && !ret_oop_type->klass()->is_loaded()) {
 741       ret_type = TypeOopPtr::BOTTOM;
 742     }
 743     int         ret_size = type2size[ret_type->basic_type()];
 744     Node*       ret_phi  = new (C) PhiNode(region, ret_type);
 745     gvn().set_type_bottom(ret_phi);
 746     _exits.ensure_stack(ret_size);
 747     assert((int)(tf()->range()->cnt() - TypeFunc::Parms) == ret_size, "good tf range");
 748     assert(method()->return_type()->size() == ret_size, "tf agrees w/ method");
 749     _exits.set_argument(0, ret_phi);  // here is where the parser finds it
 750     // Note:  ret_phi is not yet pushed, until do_exits.
 751   }
 752 }
 753 
 754 
 755 //----------------------------build_start_state-------------------------------
 756 // Construct a state which contains only the incoming arguments from an
 757 // unknown caller.  The method & bci will be NULL & InvocationEntryBci.
 758 JVMState* Compile::build_start_state(StartNode* start, const TypeFunc* tf) {
 759   int        arg_size = tf->domain()->cnt();
 760   int        max_size = MAX2(arg_size, (int)tf->range()->cnt());
 761   JVMState*  jvms     = new (this) JVMState(max_size - TypeFunc::Parms);
 762   SafePointNode* map  = new (this) SafePointNode(max_size, NULL);
 763   record_for_igvn(map);
 764   assert(arg_size == TypeFunc::Parms + (is_osr_compilation() ? 1 : method()->arg_size()), "correct arg_size");
 765   Node_Notes* old_nn = default_node_notes();
 766   if (old_nn != NULL && has_method()) {
 767     Node_Notes* entry_nn = old_nn->clone(this);
 768     JVMState* entry_jvms = new(this) JVMState(method(), old_nn->jvms());
 769     entry_jvms->set_offsets(0);
 770     entry_jvms->set_bci(entry_bci());
 771     entry_nn->set_jvms(entry_jvms);
 772     set_default_node_notes(entry_nn);
 773   }
 774   uint i;
 775   for (i = 0; i < (uint)arg_size; i++) {
 776     Node* parm = initial_gvn()->transform(new (this) ParmNode(start, i));
 777     map->init_req(i, parm);
 778     // Record all these guys for later GVN.
 779     record_for_igvn(parm);
 780   }
 781   for (; i < map->req(); i++) {
 782     map->init_req(i, top());
 783   }
 784   assert(jvms->argoff() == TypeFunc::Parms, "parser gets arguments here");
 785   set_default_node_notes(old_nn);
 786   map->set_jvms(jvms);
 787   jvms->set_map(map);
 788   return jvms;
 789 }
 790 
 791 //-----------------------------make_node_notes---------------------------------
 792 Node_Notes* Parse::make_node_notes(Node_Notes* caller_nn) {
 793   if (caller_nn == NULL)  return NULL;
 794   Node_Notes* nn = caller_nn->clone(C);
 795   JVMState* caller_jvms = nn->jvms();
 796   JVMState* jvms = new (C) JVMState(method(), caller_jvms);
 797   jvms->set_offsets(0);
 798   jvms->set_bci(_entry_bci);
 799   nn->set_jvms(jvms);
 800   return nn;
 801 }
 802 
 803 
 804 //--------------------------return_values--------------------------------------
 805 void Compile::return_values(JVMState* jvms) {
 806   GraphKit kit(jvms);
 807   Node* ret = new (this) ReturnNode(TypeFunc::Parms,
 808                              kit.control(),
 809                              kit.i_o(),
 810                              kit.reset_memory(),
 811                              kit.frameptr(),
 812                              kit.returnadr());
 813   // Add zero or 1 return values
 814   int ret_size = tf()->range()->cnt() - TypeFunc::Parms;
 815   if (ret_size > 0) {
 816     kit.inc_sp(-ret_size);  // pop the return value(s)
 817     kit.sync_jvms();
 818     ret->add_req(kit.argument(0));
 819     // Note:  The second dummy edge is not needed by a ReturnNode.
 820   }
 821   // bind it to root
 822   root()->add_req(ret);
 823   record_for_igvn(ret);
 824   initial_gvn()->transform_no_reclaim(ret);
 825 }
 826 
 827 //------------------------rethrow_exceptions-----------------------------------
 828 // Bind all exception states in the list into a single RethrowNode.
 829 void Compile::rethrow_exceptions(JVMState* jvms) {
 830   GraphKit kit(jvms);
 831   if (!kit.has_exceptions())  return;  // nothing to generate
 832   // Load my combined exception state into the kit, with all phis transformed:
 833   SafePointNode* ex_map = kit.combine_and_pop_all_exception_states();
 834   Node* ex_oop = kit.use_exception_state(ex_map);
 835   RethrowNode* exit = new (this) RethrowNode(kit.control(),
 836                                       kit.i_o(), kit.reset_memory(),
 837                                       kit.frameptr(), kit.returnadr(),
 838                                       // like a return but with exception input
 839                                       ex_oop);
 840   // bind to root
 841   root()->add_req(exit);
 842   record_for_igvn(exit);
 843   initial_gvn()->transform_no_reclaim(exit);
 844 }
 845 
 846 //---------------------------do_exceptions-------------------------------------
 847 // Process exceptions arising from the current bytecode.
 848 // Send caught exceptions to the proper handler within this method.
 849 // Unhandled exceptions feed into _exit.
 850 void Parse::do_exceptions() {
 851   if (!has_exceptions())  return;
 852 
 853   if (failing()) {
 854     // Pop them all off and throw them away.
 855     while (pop_exception_state() != NULL) ;
 856     return;
 857   }
 858 
 859   PreserveJVMState pjvms(this, false);
 860 
 861   SafePointNode* ex_map;
 862   while ((ex_map = pop_exception_state()) != NULL) {
 863     if (!method()->has_exception_handlers()) {
 864       // Common case:  Transfer control outward.
 865       // Doing it this early allows the exceptions to common up
 866       // even between adjacent method calls.
 867       throw_to_exit(ex_map);
 868     } else {
 869       // Have to look at the exception first.
 870       assert(stopped(), "catch_inline_exceptions trashes the map");
 871       catch_inline_exceptions(ex_map);
 872       stop_and_kill_map();      // we used up this exception state; kill it
 873     }
 874   }
 875 
 876   // We now return to our regularly scheduled program:
 877 }
 878 
 879 //---------------------------throw_to_exit-------------------------------------
 880 // Merge the given map into an exception exit from this method.
 881 // The exception exit will handle any unlocking of receiver.
 882 // The ex_oop must be saved within the ex_map, unlike merge_exception.
 883 void Parse::throw_to_exit(SafePointNode* ex_map) {
 884   // Pop the JVMS to (a copy of) the caller.
 885   GraphKit caller;
 886   caller.set_map_clone(_caller->map());
 887   caller.set_bci(_caller->bci());
 888   caller.set_sp(_caller->sp());
 889   // Copy out the standard machine state:
 890   for (uint i = 0; i < TypeFunc::Parms; i++) {
 891     caller.map()->set_req(i, ex_map->in(i));
 892   }
 893   // ...and the exception:
 894   Node*          ex_oop        = saved_ex_oop(ex_map);
 895   SafePointNode* caller_ex_map = caller.make_exception_state(ex_oop);
 896   // Finally, collect the new exception state in my exits:
 897   _exits.add_exception_state(caller_ex_map);
 898 }
 899 
 900 //------------------------------do_exits---------------------------------------
 901 void Parse::do_exits() {
 902   set_parse_bci(InvocationEntryBci);
 903 
 904   // Now peephole on the return bits
 905   Node* region = _exits.control();
 906   _exits.set_control(gvn().transform(region));
 907 
 908   Node* iophi = _exits.i_o();
 909   _exits.set_i_o(gvn().transform(iophi));
 910 
 911   // Figure out if we need to emit the trailing barrier. The barrier is only
 912   // needed in the constructors, and only in three cases:
 913   //
 914   // 1. The constructor wrote a final. The effects of all initializations
 915   //    must be committed to memory before any code after the constructor
 916   //    publishes the reference to the newly constructed object. Rather
 917   //    than wait for the publication, we simply block the writes here.
 918   //    Rather than put a barrier on only those writes which are required
 919   //    to complete, we force all writes to complete.
 920   //
 921   // 2. On PPC64, also add MemBarRelease for constructors which write
 922   //    volatile fields. As support_IRIW_for_not_multiple_copy_atomic_cpu
 923   //    is set on PPC64, no sync instruction is issued after volatile
 924   //    stores. We want to guarantee the same behavior as on platforms
 925   //    with total store order, although this is not required by the Java
 926   //    memory model. So as with finals, we add a barrier here.
 927   //
 928   // 3. Experimental VM option is used to force the barrier if any field
 929   //    was written out in the constructor.





 930   //
 931   // "All bets are off" unless the first publication occurs after a
 932   // normal return from the constructor.  We do not attempt to detect
 933   // such unusual early publications.  But no barrier is needed on
 934   // exceptional returns, since they cannot publish normally.
 935   //
 936   if (method()->is_initializer() &&
 937         (wrote_final() ||
 938            PPC64_ONLY(wrote_volatile() ||)
 939            (AlwaysSafeConstructors && wrote_fields()))) {
 940     _exits.insert_mem_bar(Op_MemBarRelease, alloc_with_final());
 941 #ifndef PRODUCT
 942     if (PrintOpto && (Verbose || WizardMode)) {
 943       method()->print_name();
 944       tty->print_cr(" writes finals and needs a memory barrier");
 945     }
 946 #endif
 947   }
 948 
 949   for (MergeMemStream mms(_exits.merged_memory()); mms.next_non_empty(); ) {
 950     // transform each slice of the original memphi:
 951     mms.set_memory(_gvn.transform(mms.memory()));
 952   }
 953 
 954   if (tf()->range()->cnt() > TypeFunc::Parms) {
 955     const Type* ret_type = tf()->range()->field_at(TypeFunc::Parms);
 956     Node*       ret_phi  = _gvn.transform( _exits.argument(0) );
 957     assert(_exits.control()->is_top() || !_gvn.type(ret_phi)->empty(), "return value must be well defined");
 958     _exits.push_node(ret_type->basic_type(), ret_phi);
 959   }
 960 
 961   // Note:  Logic for creating and optimizing the ReturnNode is in Compile.
 962 
 963   // Unlock along the exceptional paths.
 964   // This is done late so that we can common up equivalent exceptions
 965   // (e.g., null checks) arising from multiple points within this method.
 966   // See GraphKit::add_exception_state, which performs the commoning.
 967   bool do_synch = method()->is_synchronized() && GenerateSynchronizationCode;
 968 
 969   // record exit from a method if compiled while Dtrace is turned on.
 970   if (do_synch || C->env()->dtrace_method_probes()) {
 971     // First move the exception list out of _exits:
 972     GraphKit kit(_exits.transfer_exceptions_into_jvms());
 973     SafePointNode* normal_map = kit.map();  // keep this guy safe
 974     // Now re-collect the exceptions into _exits:
 975     SafePointNode* ex_map;
 976     while ((ex_map = kit.pop_exception_state()) != NULL) {
 977       Node* ex_oop = kit.use_exception_state(ex_map);
 978       // Force the exiting JVM state to have this method at InvocationEntryBci.
 979       // The exiting JVM state is otherwise a copy of the calling JVMS.
 980       JVMState* caller = kit.jvms();
 981       JVMState* ex_jvms = caller->clone_shallow(C);
 982       ex_jvms->set_map(kit.clone_map());
 983       ex_jvms->map()->set_jvms(ex_jvms);
 984       ex_jvms->set_bci(   InvocationEntryBci);
 985       kit.set_jvms(ex_jvms);
 986       if (do_synch) {
 987         // Add on the synchronized-method box/object combo
 988         kit.map()->push_monitor(_synch_lock);
 989         // Unlock!
 990         kit.shared_unlock(_synch_lock->box_node(), _synch_lock->obj_node());
 991       }
 992       if (C->env()->dtrace_method_probes()) {
 993         kit.make_dtrace_method_exit(method());
 994       }
 995       // Done with exception-path processing.
 996       ex_map = kit.make_exception_state(ex_oop);
 997       assert(ex_jvms->same_calls_as(ex_map->jvms()), "sanity");
 998       // Pop the last vestige of this method:
 999       ex_map->set_jvms(caller->clone_shallow(C));
1000       ex_map->jvms()->set_map(ex_map);
1001       _exits.push_exception_state(ex_map);
1002     }
1003     assert(_exits.map() == normal_map, "keep the same return state");
1004   }
1005 
1006   {
1007     // Capture very early exceptions (receiver null checks) from caller JVMS
1008     GraphKit caller(_caller);
1009     SafePointNode* ex_map;
1010     while ((ex_map = caller.pop_exception_state()) != NULL) {
1011       _exits.add_exception_state(ex_map);
1012     }
1013   }
1014 }
1015 
1016 //-----------------------------create_entry_map-------------------------------
1017 // Initialize our parser map to contain the types at method entry.
1018 // For OSR, the map contains a single RawPtr parameter.
1019 // Initial monitor locking for sync. methods is performed by do_method_entry.
1020 SafePointNode* Parse::create_entry_map() {
1021   // Check for really stupid bail-out cases.
1022   uint len = TypeFunc::Parms + method()->max_locals() + method()->max_stack();
1023   if (len >= 32760) {
1024     C->record_method_not_compilable_all_tiers("too many local variables");
1025     return NULL;
1026   }
1027 
1028   // If this is an inlined method, we may have to do a receiver null check.
1029   if (_caller->has_method() && is_normal_parse() && !method()->is_static()) {
1030     GraphKit kit(_caller);
1031     kit.null_check_receiver_before_call(method());
1032     _caller = kit.transfer_exceptions_into_jvms();
1033     if (kit.stopped()) {
1034       _exits.add_exception_states_from(_caller);
1035       _exits.set_jvms(_caller);
1036       return NULL;
1037     }
1038   }
1039 
1040   assert(method() != NULL, "parser must have a method");
1041 
1042   // Create an initial safepoint to hold JVM state during parsing
1043   JVMState* jvms = new (C) JVMState(method(), _caller->has_method() ? _caller : NULL);
1044   set_map(new (C) SafePointNode(len, jvms));
1045   jvms->set_map(map());
1046   record_for_igvn(map());
1047   assert(jvms->endoff() == len, "correct jvms sizing");
1048 
1049   SafePointNode* inmap = _caller->map();
1050   assert(inmap != NULL, "must have inmap");
1051 
1052   uint i;
1053 
1054   // Pass thru the predefined input parameters.
1055   for (i = 0; i < TypeFunc::Parms; i++) {
1056     map()->init_req(i, inmap->in(i));
1057   }
1058 
1059   if (depth() == 1) {
1060     assert(map()->memory()->Opcode() == Op_Parm, "");
1061     // Insert the memory aliasing node
1062     set_all_memory(reset_memory());
1063   }
1064   assert(merged_memory(), "");
1065 
1066   // Now add the locals which are initially bound to arguments:
1067   uint arg_size = tf()->domain()->cnt();
1068   ensure_stack(arg_size - TypeFunc::Parms);  // OSR methods have funny args
1069   for (i = TypeFunc::Parms; i < arg_size; i++) {
1070     map()->init_req(i, inmap->argument(_caller, i - TypeFunc::Parms));
1071   }
1072 
1073   // Clear out the rest of the map (locals and stack)
1074   for (i = arg_size; i < len; i++) {
1075     map()->init_req(i, top());
1076   }
1077 
1078   SafePointNode* entry_map = stop();
1079   return entry_map;
1080 }
1081 
1082 //-----------------------------do_method_entry--------------------------------
1083 // Emit any code needed in the pseudo-block before BCI zero.
1084 // The main thing to do is lock the receiver of a synchronized method.
1085 void Parse::do_method_entry() {
1086   set_parse_bci(InvocationEntryBci); // Pseudo-BCP
1087   set_sp(0);                      // Java Stack Pointer
1088 
1089   NOT_PRODUCT( count_compiled_calls(true/*at_method_entry*/, false/*is_inline*/); )
1090 
1091   if (C->env()->dtrace_method_probes()) {
1092     make_dtrace_method_entry(method());
1093   }
1094 
1095   // If the method is synchronized, we need to construct a lock node, attach
1096   // it to the Start node, and pin it there.
1097   if (method()->is_synchronized()) {
1098     // Insert a FastLockNode right after the Start which takes as arguments
1099     // the current thread pointer, the "this" pointer & the address of the
1100     // stack slot pair used for the lock.  The "this" pointer is a projection
1101     // off the start node, but the locking spot has to be constructed by
1102     // creating a ConLNode of 0, and boxing it with a BoxLockNode.  The BoxLockNode
1103     // becomes the second argument to the FastLockNode call.  The
1104     // FastLockNode becomes the new control parent to pin it to the start.
1105 
1106     // Setup Object Pointer
1107     Node *lock_obj = NULL;
1108     if(method()->is_static()) {
1109       ciInstance* mirror = _method->holder()->java_mirror();
1110       const TypeInstPtr *t_lock = TypeInstPtr::make(mirror);
1111       lock_obj = makecon(t_lock);
1112     } else {                  // Else pass the "this" pointer,
1113       lock_obj = local(0);    // which is Parm0 from StartNode
1114     }
1115     // Clear out dead values from the debug info.
1116     kill_dead_locals();
1117     // Build the FastLockNode
1118     _synch_lock = shared_lock(lock_obj);
1119   }
1120 
1121   // Feed profiling data for parameters to the type system so it can
1122   // propagate it as speculative types
1123   record_profiled_parameters_for_speculation();
1124 
1125   if (depth() == 1) {
1126     increment_and_test_invocation_counter(Tier2CompileThreshold);
1127   }
1128 }
1129 
1130 //------------------------------init_blocks------------------------------------
1131 // Initialize our parser map to contain the types/monitors at method entry.
1132 void Parse::init_blocks() {
1133   // Create the blocks.
1134   _block_count = flow()->block_count();
1135   _blocks = NEW_RESOURCE_ARRAY(Block, _block_count);
1136   Copy::zero_to_bytes(_blocks, sizeof(Block)*_block_count);
1137 
1138   int rpo;
1139 
1140   // Initialize the structs.
1141   for (rpo = 0; rpo < block_count(); rpo++) {
1142     Block* block = rpo_at(rpo);
1143     block->init_node(this, rpo);
1144   }
1145 
1146   // Collect predecessor and successor information.
1147   for (rpo = 0; rpo < block_count(); rpo++) {
1148     Block* block = rpo_at(rpo);
1149     block->init_graph(this);
1150   }
1151 }
1152 
1153 //-------------------------------init_node-------------------------------------
1154 void Parse::Block::init_node(Parse* outer, int rpo) {
1155   _flow = outer->flow()->rpo_at(rpo);
1156   _pred_count = 0;
1157   _preds_parsed = 0;
1158   _count = 0;
1159   assert(pred_count() == 0 && preds_parsed() == 0, "sanity");
1160   assert(!(is_merged() || is_parsed() || is_handler() || has_merged_backedge()), "sanity");
1161   assert(_live_locals.size() == 0, "sanity");
1162 
1163   // entry point has additional predecessor
1164   if (flow()->is_start())  _pred_count++;
1165   assert(flow()->is_start() == (this == outer->start_block()), "");
1166 }
1167 
1168 //-------------------------------init_graph------------------------------------
1169 void Parse::Block::init_graph(Parse* outer) {
1170   // Create the successor list for this parser block.
1171   GrowableArray<ciTypeFlow::Block*>* tfs = flow()->successors();
1172   GrowableArray<ciTypeFlow::Block*>* tfe = flow()->exceptions();
1173   int ns = tfs->length();
1174   int ne = tfe->length();
1175   _num_successors = ns;
1176   _all_successors = ns+ne;
1177   _successors = (ns+ne == 0) ? NULL : NEW_RESOURCE_ARRAY(Block*, ns+ne);
1178   int p = 0;
1179   for (int i = 0; i < ns+ne; i++) {
1180     ciTypeFlow::Block* tf2 = (i < ns) ? tfs->at(i) : tfe->at(i-ns);
1181     Block* block2 = outer->rpo_at(tf2->rpo());
1182     _successors[i] = block2;
1183 
1184     // Accumulate pred info for the other block, too.
1185     if (i < ns) {
1186       block2->_pred_count++;
1187     } else {
1188       block2->_is_handler = true;
1189     }
1190 
1191     #ifdef ASSERT
1192     // A block's successors must be distinguishable by BCI.
1193     // That is, no bytecode is allowed to branch to two different
1194     // clones of the same code location.
1195     for (int j = 0; j < i; j++) {
1196       Block* block1 = _successors[j];
1197       if (block1 == block2)  continue;  // duplicates are OK
1198       assert(block1->start() != block2->start(), "successors have unique bcis");
1199     }
1200     #endif
1201   }
1202 
1203   // Note: We never call next_path_num along exception paths, so they
1204   // never get processed as "ready".  Also, the input phis of exception
1205   // handlers get specially processed, so that
1206 }
1207 
1208 //---------------------------successor_for_bci---------------------------------
1209 Parse::Block* Parse::Block::successor_for_bci(int bci) {
1210   for (int i = 0; i < all_successors(); i++) {
1211     Block* block2 = successor_at(i);
1212     if (block2->start() == bci)  return block2;
1213   }
1214   // We can actually reach here if ciTypeFlow traps out a block
1215   // due to an unloaded class, and concurrently with compilation the
1216   // class is then loaded, so that a later phase of the parser is
1217   // able to see more of the bytecode CFG.  Or, the flow pass and
1218   // the parser can have a minor difference of opinion about executability
1219   // of bytecodes.  For example, "obj.field = null" is executable even
1220   // if the field's type is an unloaded class; the flow pass used to
1221   // make a trap for such code.
1222   return NULL;
1223 }
1224 
1225 
1226 //-----------------------------stack_type_at-----------------------------------
1227 const Type* Parse::Block::stack_type_at(int i) const {
1228   return get_type(flow()->stack_type_at(i));
1229 }
1230 
1231 
1232 //-----------------------------local_type_at-----------------------------------
1233 const Type* Parse::Block::local_type_at(int i) const {
1234   // Make dead locals fall to bottom.
1235   if (_live_locals.size() == 0) {
1236     MethodLivenessResult live_locals = flow()->outer()->method()->liveness_at_bci(start());
1237     // This bitmap can be zero length if we saw a breakpoint.
1238     // In such cases, pretend they are all live.
1239     ((Block*)this)->_live_locals = live_locals;
1240   }
1241   if (_live_locals.size() > 0 && !_live_locals.at(i))
1242     return Type::BOTTOM;
1243 
1244   return get_type(flow()->local_type_at(i));
1245 }
1246 
1247 
1248 #ifndef PRODUCT
1249 
1250 //----------------------------name_for_bc--------------------------------------
1251 // helper method for BytecodeParseHistogram
1252 static const char* name_for_bc(int i) {
1253   return Bytecodes::is_defined(i) ? Bytecodes::name(Bytecodes::cast(i)) : "xxxunusedxxx";
1254 }
1255 
1256 //----------------------------BytecodeParseHistogram------------------------------------
1257 Parse::BytecodeParseHistogram::BytecodeParseHistogram(Parse *p, Compile *c) {
1258   _parser   = p;
1259   _compiler = c;
1260   if( ! _initialized ) { _initialized = true; reset(); }
1261 }
1262 
1263 //----------------------------current_count------------------------------------
1264 int Parse::BytecodeParseHistogram::current_count(BPHType bph_type) {
1265   switch( bph_type ) {
1266   case BPH_transforms: { return _parser->gvn().made_progress(); }
1267   case BPH_values:     { return _parser->gvn().made_new_values(); }
1268   default: { ShouldNotReachHere(); return 0; }
1269   }
1270 }
1271 
1272 //----------------------------initialized--------------------------------------
1273 bool Parse::BytecodeParseHistogram::initialized() { return _initialized; }
1274 
1275 //----------------------------reset--------------------------------------------
1276 void Parse::BytecodeParseHistogram::reset() {
1277   int i = Bytecodes::number_of_codes;
1278   while (i-- > 0) { _bytecodes_parsed[i] = 0; _nodes_constructed[i] = 0; _nodes_transformed[i] = 0; _new_values[i] = 0; }
1279 }
1280 
1281 //----------------------------set_initial_state--------------------------------
1282 // Record info when starting to parse one bytecode
1283 void Parse::BytecodeParseHistogram::set_initial_state( Bytecodes::Code bc ) {
1284   if( PrintParseStatistics && !_parser->is_osr_parse() ) {
1285     _initial_bytecode    = bc;
1286     _initial_node_count  = _compiler->unique();
1287     _initial_transforms  = current_count(BPH_transforms);
1288     _initial_values      = current_count(BPH_values);
1289   }
1290 }
1291 
1292 //----------------------------record_change--------------------------------
1293 // Record results of parsing one bytecode
1294 void Parse::BytecodeParseHistogram::record_change() {
1295   if( PrintParseStatistics && !_parser->is_osr_parse() ) {
1296     ++_bytecodes_parsed[_initial_bytecode];
1297     _nodes_constructed [_initial_bytecode] += (_compiler->unique() - _initial_node_count);
1298     _nodes_transformed [_initial_bytecode] += (current_count(BPH_transforms) - _initial_transforms);
1299     _new_values        [_initial_bytecode] += (current_count(BPH_values)     - _initial_values);
1300   }
1301 }
1302 
1303 
1304 //----------------------------print--------------------------------------------
1305 void Parse::BytecodeParseHistogram::print(float cutoff) {
1306   ResourceMark rm;
1307   // print profile
1308   int total  = 0;
1309   int i      = 0;
1310   for( i = 0; i < Bytecodes::number_of_codes; ++i ) { total += _bytecodes_parsed[i]; }
1311   int abs_sum = 0;
1312   tty->cr();   //0123456789012345678901234567890123456789012345678901234567890123456789
1313   tty->print_cr("Histogram of %d parsed bytecodes:", total);
1314   if( total == 0 ) { return; }
1315   tty->cr();
1316   tty->print_cr("absolute:  count of compiled bytecodes of this type");
1317   tty->print_cr("relative:  percentage contribution to compiled nodes");
1318   tty->print_cr("nodes   :  Average number of nodes constructed per bytecode");
1319   tty->print_cr("rnodes  :  Significance towards total nodes constructed, (nodes*relative)");
1320   tty->print_cr("transforms: Average amount of tranform progress per bytecode compiled");
1321   tty->print_cr("values  :  Average number of node values improved per bytecode");
1322   tty->print_cr("name    :  Bytecode name");
1323   tty->cr();
1324   tty->print_cr("  absolute  relative   nodes  rnodes  transforms  values   name");
1325   tty->print_cr("----------------------------------------------------------------------");
1326   while (--i > 0) {
1327     int       abs = _bytecodes_parsed[i];
1328     float     rel = abs * 100.0F / total;
1329     float   nodes = _bytecodes_parsed[i] == 0 ? 0 : (1.0F * _nodes_constructed[i])/_bytecodes_parsed[i];
1330     float  rnodes = _bytecodes_parsed[i] == 0 ? 0 :  rel * nodes;
1331     float  xforms = _bytecodes_parsed[i] == 0 ? 0 : (1.0F * _nodes_transformed[i])/_bytecodes_parsed[i];
1332     float  values = _bytecodes_parsed[i] == 0 ? 0 : (1.0F * _new_values       [i])/_bytecodes_parsed[i];
1333     if (cutoff <= rel) {
1334       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));
1335       abs_sum += abs;
1336     }
1337   }
1338   tty->print_cr("----------------------------------------------------------------------");
1339   float rel_sum = abs_sum * 100.0F / total;
1340   tty->print_cr("%10d  %7.2f%%    (cutoff = %.2f%%)", abs_sum, rel_sum, cutoff);
1341   tty->print_cr("----------------------------------------------------------------------");
1342   tty->cr();
1343 }
1344 #endif
1345 
1346 //----------------------------load_state_from----------------------------------
1347 // Load block/map/sp.  But not do not touch iter/bci.
1348 void Parse::load_state_from(Block* block) {
1349   set_block(block);
1350   // load the block's JVM state:
1351   set_map(block->start_map());
1352   set_sp( block->start_sp());
1353 }
1354 
1355 
1356 //-----------------------------record_state------------------------------------
1357 void Parse::Block::record_state(Parse* p) {
1358   assert(!is_merged(), "can only record state once, on 1st inflow");
1359   assert(start_sp() == p->sp(), "stack pointer must agree with ciTypeFlow");
1360   set_start_map(p->stop());
1361 }
1362 
1363 
1364 //------------------------------do_one_block-----------------------------------
1365 void Parse::do_one_block() {
1366   if (TraceOptoParse) {
1367     Block *b = block();
1368     int ns = b->num_successors();
1369     int nt = b->all_successors();
1370 
1371     tty->print("Parsing block #%d at bci [%d,%d), successors: ",
1372                   block()->rpo(), block()->start(), block()->limit());
1373     for (int i = 0; i < nt; i++) {
1374       tty->print((( i < ns) ? " %d" : " %d(e)"), b->successor_at(i)->rpo());
1375     }
1376     if (b->is_loop_head()) tty->print("  lphd");
1377     tty->print_cr("");
1378   }
1379 
1380   assert(block()->is_merged(), "must be merged before being parsed");
1381   block()->mark_parsed();
1382   ++_blocks_parsed;
1383 
1384   // Set iterator to start of block.
1385   iter().reset_to_bci(block()->start());
1386 
1387   CompileLog* log = C->log();
1388 
1389   // Parse bytecodes
1390   while (!stopped() && !failing()) {
1391     iter().next();
1392 
1393     // Learn the current bci from the iterator:
1394     set_parse_bci(iter().cur_bci());
1395 
1396     if (bci() == block()->limit()) {
1397       // Do not walk into the next block until directed by do_all_blocks.
1398       merge(bci());
1399       break;
1400     }
1401     assert(bci() < block()->limit(), "bci still in block");
1402 
1403     if (log != NULL) {
1404       // Output an optional context marker, to help place actions
1405       // that occur during parsing of this BC.  If there is no log
1406       // output until the next context string, this context string
1407       // will be silently ignored.
1408       log->set_context("bc code='%d' bci='%d'", (int)bc(), bci());
1409     }
1410 
1411     if (block()->has_trap_at(bci())) {
1412       // We must respect the flow pass's traps, because it will refuse
1413       // to produce successors for trapping blocks.
1414       int trap_index = block()->flow()->trap_index();
1415       assert(trap_index != 0, "trap index must be valid");
1416       uncommon_trap(trap_index);
1417       break;
1418     }
1419 
1420     NOT_PRODUCT( parse_histogram()->set_initial_state(bc()); );
1421 
1422 #ifdef ASSERT
1423     int pre_bc_sp = sp();
1424     int inputs, depth;
1425     bool have_se = !stopped() && compute_stack_effects(inputs, depth);
1426     assert(!have_se || pre_bc_sp >= inputs, err_msg_res("have enough stack to execute this BC: pre_bc_sp=%d, inputs=%d", pre_bc_sp, inputs));
1427 #endif //ASSERT
1428 
1429     do_one_bytecode();
1430 
1431     assert(!have_se || stopped() || failing() || (sp() - pre_bc_sp) == depth,
1432            err_msg_res("incorrect depth prediction: sp=%d, pre_bc_sp=%d, depth=%d", sp(), pre_bc_sp, depth));
1433 
1434     do_exceptions();
1435 
1436     NOT_PRODUCT( parse_histogram()->record_change(); );
1437 
1438     if (log != NULL)
1439       log->clear_context();  // skip marker if nothing was printed
1440 
1441     // Fall into next bytecode.  Each bytecode normally has 1 sequential
1442     // successor which is typically made ready by visiting this bytecode.
1443     // If the successor has several predecessors, then it is a merge
1444     // point, starts a new basic block, and is handled like other basic blocks.
1445   }
1446 }
1447 
1448 
1449 //------------------------------merge------------------------------------------
1450 void Parse::set_parse_bci(int bci) {
1451   set_bci(bci);
1452   Node_Notes* nn = C->default_node_notes();
1453   if (nn == NULL)  return;
1454 
1455   // Collect debug info for inlined calls unless -XX:-DebugInlinedCalls.
1456   if (!DebugInlinedCalls && depth() > 1) {
1457     return;
1458   }
1459 
1460   // Update the JVMS annotation, if present.
1461   JVMState* jvms = nn->jvms();
1462   if (jvms != NULL && jvms->bci() != bci) {
1463     // Update the JVMS.
1464     jvms = jvms->clone_shallow(C);
1465     jvms->set_bci(bci);
1466     nn->set_jvms(jvms);
1467   }
1468 }
1469 
1470 //------------------------------merge------------------------------------------
1471 // Merge the current mapping into the basic block starting at bci
1472 void Parse::merge(int target_bci) {
1473   Block* target = successor_for_bci(target_bci);
1474   if (target == NULL) { handle_missing_successor(target_bci); return; }
1475   assert(!target->is_ready(), "our arrival must be expected");
1476   int pnum = target->next_path_num();
1477   merge_common(target, pnum);
1478 }
1479 
1480 //-------------------------merge_new_path--------------------------------------
1481 // Merge the current mapping into the basic block, using a new path
1482 void Parse::merge_new_path(int target_bci) {
1483   Block* target = successor_for_bci(target_bci);
1484   if (target == NULL) { handle_missing_successor(target_bci); return; }
1485   assert(!target->is_ready(), "new path into frozen graph");
1486   int pnum = target->add_new_path();
1487   merge_common(target, pnum);
1488 }
1489 
1490 //-------------------------merge_exception-------------------------------------
1491 // Merge the current mapping into the basic block starting at bci
1492 // The ex_oop must be pushed on the stack, unlike throw_to_exit.
1493 void Parse::merge_exception(int target_bci) {
1494   assert(sp() == 1, "must have only the throw exception on the stack");
1495   Block* target = successor_for_bci(target_bci);
1496   if (target == NULL) { handle_missing_successor(target_bci); return; }
1497   assert(target->is_handler(), "exceptions are handled by special blocks");
1498   int pnum = target->add_new_path();
1499   merge_common(target, pnum);
1500 }
1501 
1502 //--------------------handle_missing_successor---------------------------------
1503 void Parse::handle_missing_successor(int target_bci) {
1504 #ifndef PRODUCT
1505   Block* b = block();
1506   int trap_bci = b->flow()->has_trap()? b->flow()->trap_bci(): -1;
1507   tty->print_cr("### Missing successor at bci:%d for block #%d (trap_bci:%d)", target_bci, b->rpo(), trap_bci);
1508 #endif
1509   ShouldNotReachHere();
1510 }
1511 
1512 //--------------------------merge_common---------------------------------------
1513 void Parse::merge_common(Parse::Block* target, int pnum) {
1514   if (TraceOptoParse) {
1515     tty->print("Merging state at block #%d bci:%d", target->rpo(), target->start());
1516   }
1517 
1518   // Zap extra stack slots to top
1519   assert(sp() == target->start_sp(), "");
1520   clean_stack(sp());
1521 
1522   if (!target->is_merged()) {   // No prior mapping at this bci
1523     if (TraceOptoParse) { tty->print(" with empty state");  }
1524 
1525     // If this path is dead, do not bother capturing it as a merge.
1526     // It is "as if" we had 1 fewer predecessors from the beginning.
1527     if (stopped()) {
1528       if (TraceOptoParse)  tty->print_cr(", but path is dead and doesn't count");
1529       return;
1530     }
1531 
1532     // Record that a new block has been merged.
1533     ++_blocks_merged;
1534 
1535     // Make a region if we know there are multiple or unpredictable inputs.
1536     // (Also, if this is a plain fall-through, we might see another region,
1537     // which must not be allowed into this block's map.)
1538     if (pnum > PhiNode::Input         // Known multiple inputs.
1539         || target->is_handler()       // These have unpredictable inputs.
1540         || target->is_loop_head()     // Known multiple inputs
1541         || control()->is_Region()) {  // We must hide this guy.
1542 
1543       int current_bci = bci();
1544       set_parse_bci(target->start()); // Set target bci
1545       if (target->is_SEL_head()) {
1546         DEBUG_ONLY( target->mark_merged_backedge(block()); )
1547         if (target->start() == 0) {
1548           // Add loop predicate for the special case when
1549           // there are backbranches to the method entry.
1550           add_predicate();
1551         }
1552       }
1553       // Add a Region to start the new basic block.  Phis will be added
1554       // later lazily.
1555       int edges = target->pred_count();
1556       if (edges < pnum)  edges = pnum;  // might be a new path!
1557       RegionNode *r = new (C) RegionNode(edges+1);
1558       gvn().set_type(r, Type::CONTROL);
1559       record_for_igvn(r);
1560       // zap all inputs to NULL for debugging (done in Node(uint) constructor)
1561       // for (int j = 1; j < edges+1; j++) { r->init_req(j, NULL); }
1562       r->init_req(pnum, control());
1563       set_control(r);
1564       set_parse_bci(current_bci); // Restore bci
1565     }
1566 
1567     // Convert the existing Parser mapping into a mapping at this bci.
1568     store_state_to(target);
1569     assert(target->is_merged(), "do not come here twice");
1570 
1571   } else {                      // Prior mapping at this bci
1572     if (TraceOptoParse) {  tty->print(" with previous state"); }
1573 #ifdef ASSERT
1574     if (target->is_SEL_head()) {
1575       target->mark_merged_backedge(block());
1576     }
1577 #endif
1578     // We must not manufacture more phis if the target is already parsed.
1579     bool nophi = target->is_parsed();
1580 
1581     SafePointNode* newin = map();// Hang on to incoming mapping
1582     Block* save_block = block(); // Hang on to incoming block;
1583     load_state_from(target);    // Get prior mapping
1584 
1585     assert(newin->jvms()->locoff() == jvms()->locoff(), "JVMS layouts agree");
1586     assert(newin->jvms()->stkoff() == jvms()->stkoff(), "JVMS layouts agree");
1587     assert(newin->jvms()->monoff() == jvms()->monoff(), "JVMS layouts agree");
1588     assert(newin->jvms()->endoff() == jvms()->endoff(), "JVMS layouts agree");
1589 
1590     // Iterate over my current mapping and the old mapping.
1591     // Where different, insert Phi functions.
1592     // Use any existing Phi functions.
1593     assert(control()->is_Region(), "must be merging to a region");
1594     RegionNode* r = control()->as_Region();
1595 
1596     // Compute where to merge into
1597     // Merge incoming control path
1598     r->init_req(pnum, newin->control());
1599 
1600     if (pnum == 1) {            // Last merge for this Region?
1601       if (!block()->flow()->is_irreducible_entry()) {
1602         Node* result = _gvn.transform_no_reclaim(r);
1603         if (r != result && TraceOptoParse) {
1604           tty->print_cr("Block #%d replace %d with %d", block()->rpo(), r->_idx, result->_idx);
1605         }
1606       }
1607       record_for_igvn(r);
1608     }
1609 
1610     // Update all the non-control inputs to map:
1611     assert(TypeFunc::Parms == newin->jvms()->locoff(), "parser map should contain only youngest jvms");
1612     bool check_elide_phi = target->is_SEL_backedge(save_block);
1613     for (uint j = 1; j < newin->req(); j++) {
1614       Node* m = map()->in(j);   // Current state of target.
1615       Node* n = newin->in(j);   // Incoming change to target state.
1616       PhiNode* phi;
1617       if (m->is_Phi() && m->as_Phi()->region() == r)
1618         phi = m->as_Phi();
1619       else
1620         phi = NULL;
1621       if (m != n) {             // Different; must merge
1622         switch (j) {
1623         // Frame pointer and Return Address never changes
1624         case TypeFunc::FramePtr:// Drop m, use the original value
1625         case TypeFunc::ReturnAdr:
1626           break;
1627         case TypeFunc::Memory:  // Merge inputs to the MergeMem node
1628           assert(phi == NULL, "the merge contains phis, not vice versa");
1629           merge_memory_edges(n->as_MergeMem(), pnum, nophi);
1630           continue;
1631         default:                // All normal stuff
1632           if (phi == NULL) {
1633             const JVMState* jvms = map()->jvms();
1634             if (EliminateNestedLocks &&
1635                 jvms->is_mon(j) && jvms->is_monitor_box(j)) {
1636               // BoxLock nodes are not commoning.
1637               // Use old BoxLock node as merged box.
1638               assert(newin->jvms()->is_monitor_box(j), "sanity");
1639               // This assert also tests that nodes are BoxLock.
1640               assert(BoxLockNode::same_slot(n, m), "sanity");
1641               C->gvn_replace_by(n, m);
1642             } else if (!check_elide_phi || !target->can_elide_SEL_phi(j)) {
1643               phi = ensure_phi(j, nophi);
1644             }
1645           }
1646           break;
1647         }
1648       }
1649       // At this point, n might be top if:
1650       //  - there is no phi (because TypeFlow detected a conflict), or
1651       //  - the corresponding control edges is top (a dead incoming path)
1652       // It is a bug if we create a phi which sees a garbage value on a live path.
1653 
1654       if (phi != NULL) {
1655         assert(n != top() || r->in(pnum) == top(), "live value must not be garbage");
1656         assert(phi->region() == r, "");
1657         phi->set_req(pnum, n);  // Then add 'n' to the merge
1658         if (pnum == PhiNode::Input) {
1659           // Last merge for this Phi.
1660           // So far, Phis have had a reasonable type from ciTypeFlow.
1661           // Now _gvn will join that with the meet of current inputs.
1662           // BOTTOM is never permissible here, 'cause pessimistically
1663           // Phis of pointers cannot lose the basic pointer type.
1664           debug_only(const Type* bt1 = phi->bottom_type());
1665           assert(bt1 != Type::BOTTOM, "should not be building conflict phis");
1666           map()->set_req(j, _gvn.transform_no_reclaim(phi));
1667           debug_only(const Type* bt2 = phi->bottom_type());
1668           assert(bt2->higher_equal_speculative(bt1), "must be consistent with type-flow");
1669           record_for_igvn(phi);
1670         }
1671       }
1672     } // End of for all values to be merged
1673 
1674     if (pnum == PhiNode::Input &&
1675         !r->in(0)) {         // The occasional useless Region
1676       assert(control() == r, "");
1677       set_control(r->nonnull_req());
1678     }
1679 
1680     // newin has been subsumed into the lazy merge, and is now dead.
1681     set_block(save_block);
1682 
1683     stop();                     // done with this guy, for now
1684   }
1685 
1686   if (TraceOptoParse) {
1687     tty->print_cr(" on path %d", pnum);
1688   }
1689 
1690   // Done with this parser state.
1691   assert(stopped(), "");
1692 }
1693 
1694 
1695 //--------------------------merge_memory_edges---------------------------------
1696 void Parse::merge_memory_edges(MergeMemNode* n, int pnum, bool nophi) {
1697   // (nophi means we must not create phis, because we already parsed here)
1698   assert(n != NULL, "");
1699   // Merge the inputs to the MergeMems
1700   MergeMemNode* m = merged_memory();
1701 
1702   assert(control()->is_Region(), "must be merging to a region");
1703   RegionNode* r = control()->as_Region();
1704 
1705   PhiNode* base = NULL;
1706   MergeMemNode* remerge = NULL;
1707   for (MergeMemStream mms(m, n); mms.next_non_empty2(); ) {
1708     Node *p = mms.force_memory();
1709     Node *q = mms.memory2();
1710     if (mms.is_empty() && nophi) {
1711       // Trouble:  No new splits allowed after a loop body is parsed.
1712       // Instead, wire the new split into a MergeMem on the backedge.
1713       // The optimizer will sort it out, slicing the phi.
1714       if (remerge == NULL) {
1715         assert(base != NULL, "");
1716         assert(base->in(0) != NULL, "should not be xformed away");
1717         remerge = MergeMemNode::make(C, base->in(pnum));
1718         gvn().set_type(remerge, Type::MEMORY);
1719         base->set_req(pnum, remerge);
1720       }
1721       remerge->set_memory_at(mms.alias_idx(), q);
1722       continue;
1723     }
1724     assert(!q->is_MergeMem(), "");
1725     PhiNode* phi;
1726     if (p != q) {
1727       phi = ensure_memory_phi(mms.alias_idx(), nophi);
1728     } else {
1729       if (p->is_Phi() && p->as_Phi()->region() == r)
1730         phi = p->as_Phi();
1731       else
1732         phi = NULL;
1733     }
1734     // Insert q into local phi
1735     if (phi != NULL) {
1736       assert(phi->region() == r, "");
1737       p = phi;
1738       phi->set_req(pnum, q);
1739       if (mms.at_base_memory()) {
1740         base = phi;  // delay transforming it
1741       } else if (pnum == 1) {
1742         record_for_igvn(phi);
1743         p = _gvn.transform_no_reclaim(phi);
1744       }
1745       mms.set_memory(p);// store back through the iterator
1746     }
1747   }
1748   // Transform base last, in case we must fiddle with remerging.
1749   if (base != NULL && pnum == 1) {
1750     record_for_igvn(base);
1751     m->set_base_memory( _gvn.transform_no_reclaim(base) );
1752   }
1753 }
1754 
1755 
1756 //------------------------ensure_phis_everywhere-------------------------------
1757 void Parse::ensure_phis_everywhere() {
1758   ensure_phi(TypeFunc::I_O);
1759 
1760   // Ensure a phi on all currently known memories.
1761   for (MergeMemStream mms(merged_memory()); mms.next_non_empty(); ) {
1762     ensure_memory_phi(mms.alias_idx());
1763     debug_only(mms.set_memory());  // keep the iterator happy
1764   }
1765 
1766   // Note:  This is our only chance to create phis for memory slices.
1767   // If we miss a slice that crops up later, it will have to be
1768   // merged into the base-memory phi that we are building here.
1769   // Later, the optimizer will comb out the knot, and build separate
1770   // phi-loops for each memory slice that matters.
1771 
1772   // Monitors must nest nicely and not get confused amongst themselves.
1773   // Phi-ify everything up to the monitors, though.
1774   uint monoff = map()->jvms()->monoff();
1775   uint nof_monitors = map()->jvms()->nof_monitors();
1776 
1777   assert(TypeFunc::Parms == map()->jvms()->locoff(), "parser map should contain only youngest jvms");
1778   bool check_elide_phi = block()->is_SEL_head();
1779   for (uint i = TypeFunc::Parms; i < monoff; i++) {
1780     if (!check_elide_phi || !block()->can_elide_SEL_phi(i)) {
1781       ensure_phi(i);
1782     }
1783   }
1784 
1785   // Even monitors need Phis, though they are well-structured.
1786   // This is true for OSR methods, and also for the rare cases where
1787   // a monitor object is the subject of a replace_in_map operation.
1788   // See bugs 4426707 and 5043395.
1789   for (uint m = 0; m < nof_monitors; m++) {
1790     ensure_phi(map()->jvms()->monitor_obj_offset(m));
1791   }
1792 }
1793 
1794 
1795 //-----------------------------add_new_path------------------------------------
1796 // Add a previously unaccounted predecessor to this block.
1797 int Parse::Block::add_new_path() {
1798   // If there is no map, return the lowest unused path number.
1799   if (!is_merged())  return pred_count()+1;  // there will be a map shortly
1800 
1801   SafePointNode* map = start_map();
1802   if (!map->control()->is_Region())
1803     return pred_count()+1;  // there may be a region some day
1804   RegionNode* r = map->control()->as_Region();
1805 
1806   // Add new path to the region.
1807   uint pnum = r->req();
1808   r->add_req(NULL);
1809 
1810   for (uint i = 1; i < map->req(); i++) {
1811     Node* n = map->in(i);
1812     if (i == TypeFunc::Memory) {
1813       // Ensure a phi on all currently known memories.
1814       for (MergeMemStream mms(n->as_MergeMem()); mms.next_non_empty(); ) {
1815         Node* phi = mms.memory();
1816         if (phi->is_Phi() && phi->as_Phi()->region() == r) {
1817           assert(phi->req() == pnum, "must be same size as region");
1818           phi->add_req(NULL);
1819         }
1820       }
1821     } else {
1822       if (n->is_Phi() && n->as_Phi()->region() == r) {
1823         assert(n->req() == pnum, "must be same size as region");
1824         n->add_req(NULL);
1825       }
1826     }
1827   }
1828 
1829   return pnum;
1830 }
1831 
1832 //------------------------------ensure_phi-------------------------------------
1833 // Turn the idx'th entry of the current map into a Phi
1834 PhiNode *Parse::ensure_phi(int idx, bool nocreate) {
1835   SafePointNode* map = this->map();
1836   Node* region = map->control();
1837   assert(region->is_Region(), "");
1838 
1839   Node* o = map->in(idx);
1840   assert(o != NULL, "");
1841 
1842   if (o == top())  return NULL; // TOP always merges into TOP
1843 
1844   if (o->is_Phi() && o->as_Phi()->region() == region) {
1845     return o->as_Phi();
1846   }
1847 
1848   // Now use a Phi here for merging
1849   assert(!nocreate, "Cannot build a phi for a block already parsed.");
1850   const JVMState* jvms = map->jvms();
1851   const Type* t;
1852   if (jvms->is_loc(idx)) {
1853     t = block()->local_type_at(idx - jvms->locoff());
1854   } else if (jvms->is_stk(idx)) {
1855     t = block()->stack_type_at(idx - jvms->stkoff());
1856   } else if (jvms->is_mon(idx)) {
1857     assert(!jvms->is_monitor_box(idx), "no phis for boxes");
1858     t = TypeInstPtr::BOTTOM; // this is sufficient for a lock object
1859   } else if ((uint)idx < TypeFunc::Parms) {
1860     t = o->bottom_type();  // Type::RETURN_ADDRESS or such-like.
1861   } else {
1862     assert(false, "no type information for this phi");
1863   }
1864 
1865   // If the type falls to bottom, then this must be a local that
1866   // is mixing ints and oops or some such.  Forcing it to top
1867   // makes it go dead.
1868   if (t == Type::BOTTOM) {
1869     map->set_req(idx, top());
1870     return NULL;
1871   }
1872 
1873   // Do not create phis for top either.
1874   // A top on a non-null control flow must be an unused even after the.phi.
1875   if (t == Type::TOP || t == Type::HALF) {
1876     map->set_req(idx, top());
1877     return NULL;
1878   }
1879 
1880   PhiNode* phi = PhiNode::make(region, o, t);
1881   gvn().set_type(phi, t);
1882   if (C->do_escape_analysis()) record_for_igvn(phi);
1883   map->set_req(idx, phi);
1884   return phi;
1885 }
1886 
1887 //--------------------------ensure_memory_phi----------------------------------
1888 // Turn the idx'th slice of the current memory into a Phi
1889 PhiNode *Parse::ensure_memory_phi(int idx, bool nocreate) {
1890   MergeMemNode* mem = merged_memory();
1891   Node* region = control();
1892   assert(region->is_Region(), "");
1893 
1894   Node *o = (idx == Compile::AliasIdxBot)? mem->base_memory(): mem->memory_at(idx);
1895   assert(o != NULL && o != top(), "");
1896 
1897   PhiNode* phi;
1898   if (o->is_Phi() && o->as_Phi()->region() == region) {
1899     phi = o->as_Phi();
1900     if (phi == mem->base_memory() && idx >= Compile::AliasIdxRaw) {
1901       // clone the shared base memory phi to make a new memory split
1902       assert(!nocreate, "Cannot build a phi for a block already parsed.");
1903       const Type* t = phi->bottom_type();
1904       const TypePtr* adr_type = C->get_adr_type(idx);
1905       phi = phi->slice_memory(adr_type);
1906       gvn().set_type(phi, t);
1907     }
1908     return phi;
1909   }
1910 
1911   // Now use a Phi here for merging
1912   assert(!nocreate, "Cannot build a phi for a block already parsed.");
1913   const Type* t = o->bottom_type();
1914   const TypePtr* adr_type = C->get_adr_type(idx);
1915   phi = PhiNode::make(region, o, t, adr_type);
1916   gvn().set_type(phi, t);
1917   if (idx == Compile::AliasIdxBot)
1918     mem->set_base_memory(phi);
1919   else
1920     mem->set_memory_at(idx, phi);
1921   return phi;
1922 }
1923 
1924 //------------------------------call_register_finalizer-----------------------
1925 // Check the klass of the receiver and call register_finalizer if the
1926 // class need finalization.
1927 void Parse::call_register_finalizer() {
1928   Node* receiver = local(0);
1929   assert(receiver != NULL && receiver->bottom_type()->isa_instptr() != NULL,
1930          "must have non-null instance type");
1931 
1932   const TypeInstPtr *tinst = receiver->bottom_type()->isa_instptr();
1933   if (tinst != NULL && tinst->klass()->is_loaded() && !tinst->klass_is_exact()) {
1934     // The type isn't known exactly so see if CHA tells us anything.
1935     ciInstanceKlass* ik = tinst->klass()->as_instance_klass();
1936     if (!Dependencies::has_finalizable_subclass(ik)) {
1937       // No finalizable subclasses so skip the dynamic check.
1938       C->dependencies()->assert_has_no_finalizable_subclasses(ik);
1939       return;
1940     }
1941   }
1942 
1943   // Insert a dynamic test for whether the instance needs
1944   // finalization.  In general this will fold up since the concrete
1945   // class is often visible so the access flags are constant.
1946   Node* klass_addr = basic_plus_adr( receiver, receiver, oopDesc::klass_offset_in_bytes() );
1947   Node* klass = _gvn.transform( LoadKlassNode::make(_gvn, immutable_memory(), klass_addr, TypeInstPtr::KLASS) );
1948 
1949   Node* access_flags_addr = basic_plus_adr(klass, klass, in_bytes(Klass::access_flags_offset()));
1950   Node* access_flags = make_load(NULL, access_flags_addr, TypeInt::INT, T_INT, MemNode::unordered);
1951 
1952   Node* mask  = _gvn.transform(new (C) AndINode(access_flags, intcon(JVM_ACC_HAS_FINALIZER)));
1953   Node* check = _gvn.transform(new (C) CmpINode(mask, intcon(0)));
1954   Node* test  = _gvn.transform(new (C) BoolNode(check, BoolTest::ne));
1955 
1956   IfNode* iff = create_and_map_if(control(), test, PROB_MAX, COUNT_UNKNOWN);
1957 
1958   RegionNode* result_rgn = new (C) RegionNode(3);
1959   record_for_igvn(result_rgn);
1960 
1961   Node *skip_register = _gvn.transform(new (C) IfFalseNode(iff));
1962   result_rgn->init_req(1, skip_register);
1963 
1964   Node *needs_register = _gvn.transform(new (C) IfTrueNode(iff));
1965   set_control(needs_register);
1966   if (stopped()) {
1967     // There is no slow path.
1968     result_rgn->init_req(2, top());
1969   } else {
1970     Node *call = make_runtime_call(RC_NO_LEAF,
1971                                    OptoRuntime::register_finalizer_Type(),
1972                                    OptoRuntime::register_finalizer_Java(),
1973                                    NULL, TypePtr::BOTTOM,
1974                                    receiver);
1975     make_slow_call_ex(call, env()->Throwable_klass(), true);
1976 
1977     Node* fast_io  = call->in(TypeFunc::I_O);
1978     Node* fast_mem = call->in(TypeFunc::Memory);
1979     // These two phis are pre-filled with copies of of the fast IO and Memory
1980     Node* io_phi   = PhiNode::make(result_rgn, fast_io,  Type::ABIO);
1981     Node* mem_phi  = PhiNode::make(result_rgn, fast_mem, Type::MEMORY, TypePtr::BOTTOM);
1982 
1983     result_rgn->init_req(2, control());
1984     io_phi    ->init_req(2, i_o());
1985     mem_phi   ->init_req(2, reset_memory());
1986 
1987     set_all_memory( _gvn.transform(mem_phi) );
1988     set_i_o(        _gvn.transform(io_phi) );
1989   }
1990 
1991   set_control( _gvn.transform(result_rgn) );
1992 }
1993 
1994 //------------------------------return_current---------------------------------
1995 // Append current _map to _exit_return
1996 void Parse::return_current(Node* value) {
1997   if (RegisterFinalizersAtInit &&
1998       method()->intrinsic_id() == vmIntrinsics::_Object_init) {
1999     call_register_finalizer();
2000   }
2001 
2002   // Do not set_parse_bci, so that return goo is credited to the return insn.
2003   set_bci(InvocationEntryBci);
2004   if (method()->is_synchronized() && GenerateSynchronizationCode) {
2005     shared_unlock(_synch_lock->box_node(), _synch_lock->obj_node());
2006   }
2007   if (C->env()->dtrace_method_probes()) {
2008     make_dtrace_method_exit(method());
2009   }
2010   SafePointNode* exit_return = _exits.map();
2011   exit_return->in( TypeFunc::Control  )->add_req( control() );
2012   exit_return->in( TypeFunc::I_O      )->add_req( i_o    () );
2013   Node *mem = exit_return->in( TypeFunc::Memory   );
2014   for (MergeMemStream mms(mem->as_MergeMem(), merged_memory()); mms.next_non_empty2(); ) {
2015     if (mms.is_empty()) {
2016       // get a copy of the base memory, and patch just this one input
2017       const TypePtr* adr_type = mms.adr_type(C);
2018       Node* phi = mms.force_memory()->as_Phi()->slice_memory(adr_type);
2019       assert(phi->as_Phi()->region() == mms.base_memory()->in(0), "");
2020       gvn().set_type_bottom(phi);
2021       phi->del_req(phi->req()-1);  // prepare to re-patch
2022       mms.set_memory(phi);
2023     }
2024     mms.memory()->add_req(mms.memory2());
2025   }
2026 
2027   // frame pointer is always same, already captured
2028   if (value != NULL) {
2029     // If returning oops to an interface-return, there is a silent free
2030     // cast from oop to interface allowed by the Verifier.  Make it explicit
2031     // here.
2032     Node* phi = _exits.argument(0);
2033     const TypeInstPtr *tr = phi->bottom_type()->isa_instptr();
2034     if( tr && tr->klass()->is_loaded() &&
2035         tr->klass()->is_interface() ) {
2036       const TypeInstPtr *tp = value->bottom_type()->isa_instptr();
2037       if (tp && tp->klass()->is_loaded() &&
2038           !tp->klass()->is_interface()) {
2039         // sharpen the type eagerly; this eases certain assert checking
2040         if (tp->higher_equal(TypeInstPtr::NOTNULL))
2041           tr = tr->join_speculative(TypeInstPtr::NOTNULL)->is_instptr();
2042         value = _gvn.transform(new (C) CheckCastPPNode(0,value,tr));
2043       }
2044     }
2045     phi->add_req(value);
2046   }
2047 
2048   stop_and_kill_map();          // This CFG path dies here
2049 }
2050 
2051 
2052 //------------------------------add_safepoint----------------------------------
2053 void Parse::add_safepoint() {
2054   // See if we can avoid this safepoint.  No need for a SafePoint immediately
2055   // after a Call (except Leaf Call) or another SafePoint.
2056   Node *proj = control();
2057   bool add_poll_param = SafePointNode::needs_polling_address_input();
2058   uint parms = add_poll_param ? TypeFunc::Parms+1 : TypeFunc::Parms;
2059   if( proj->is_Proj() ) {
2060     Node *n0 = proj->in(0);
2061     if( n0->is_Catch() ) {
2062       n0 = n0->in(0)->in(0);
2063       assert( n0->is_Call(), "expect a call here" );
2064     }
2065     if( n0->is_Call() ) {
2066       if( n0->as_Call()->guaranteed_safepoint() )
2067         return;
2068     } else if( n0->is_SafePoint() && n0->req() >= parms ) {
2069       return;
2070     }
2071   }
2072 
2073   // Clear out dead values from the debug info.
2074   kill_dead_locals();
2075 
2076   // Clone the JVM State
2077   SafePointNode *sfpnt = new (C) SafePointNode(parms, NULL);
2078 
2079   // Capture memory state BEFORE a SafePoint.  Since we can block at a
2080   // SafePoint we need our GC state to be safe; i.e. we need all our current
2081   // write barriers (card marks) to not float down after the SafePoint so we
2082   // must read raw memory.  Likewise we need all oop stores to match the card
2083   // marks.  If deopt can happen, we need ALL stores (we need the correct JVM
2084   // state on a deopt).
2085 
2086   // We do not need to WRITE the memory state after a SafePoint.  The control
2087   // edge will keep card-marks and oop-stores from floating up from below a
2088   // SafePoint and our true dependency added here will keep them from floating
2089   // down below a SafePoint.
2090 
2091   // Clone the current memory state
2092   Node* mem = MergeMemNode::make(C, map()->memory());
2093 
2094   mem = _gvn.transform(mem);
2095 
2096   // Pass control through the safepoint
2097   sfpnt->init_req(TypeFunc::Control  , control());
2098   // Fix edges normally used by a call
2099   sfpnt->init_req(TypeFunc::I_O      , top() );
2100   sfpnt->init_req(TypeFunc::Memory   , mem   );
2101   sfpnt->init_req(TypeFunc::ReturnAdr, top() );
2102   sfpnt->init_req(TypeFunc::FramePtr , top() );
2103 
2104   // Create a node for the polling address
2105   if( add_poll_param ) {
2106     Node *polladr = ConPNode::make(C, (address)os::get_polling_page());
2107     sfpnt->init_req(TypeFunc::Parms+0, _gvn.transform(polladr));
2108   }
2109 
2110   // Fix up the JVM State edges
2111   add_safepoint_edges(sfpnt);
2112   Node *transformed_sfpnt = _gvn.transform(sfpnt);
2113   set_control(transformed_sfpnt);
2114 
2115   // Provide an edge from root to safepoint.  This makes the safepoint
2116   // appear useful until the parse has completed.
2117   if( OptoRemoveUseless && transformed_sfpnt->is_SafePoint() ) {
2118     assert(C->root() != NULL, "Expect parse is still valid");
2119     C->root()->add_prec(transformed_sfpnt);
2120   }
2121 }
2122 
2123 #ifndef PRODUCT
2124 //------------------------show_parse_info--------------------------------------
2125 void Parse::show_parse_info() {
2126   InlineTree* ilt = NULL;
2127   if (C->ilt() != NULL) {
2128     JVMState* caller_jvms = is_osr_parse() ? caller()->caller() : caller();
2129     ilt = InlineTree::find_subtree_from_root(C->ilt(), caller_jvms, method());
2130   }
2131   if (PrintCompilation && Verbose) {
2132     if (depth() == 1) {
2133       if( ilt->count_inlines() ) {
2134         tty->print("    __inlined %d (%d bytes)", ilt->count_inlines(),
2135                      ilt->count_inline_bcs());
2136         tty->cr();
2137       }
2138     } else {
2139       if (method()->is_synchronized())         tty->print("s");
2140       if (method()->has_exception_handlers())  tty->print("!");
2141       // Check this is not the final compiled version
2142       if (C->trap_can_recompile()) {
2143         tty->print("-");
2144       } else {
2145         tty->print(" ");
2146       }
2147       method()->print_short_name();
2148       if (is_osr_parse()) {
2149         tty->print(" @ %d", osr_bci());
2150       }
2151       tty->print(" (%d bytes)",method()->code_size());
2152       if (ilt->count_inlines()) {
2153         tty->print(" __inlined %d (%d bytes)", ilt->count_inlines(),
2154                    ilt->count_inline_bcs());
2155       }
2156       tty->cr();
2157     }
2158   }
2159   if (PrintOpto && (depth() == 1 || PrintOptoInlining)) {
2160     // Print that we succeeded; suppress this message on the first osr parse.
2161 
2162     if (method()->is_synchronized())         tty->print("s");
2163     if (method()->has_exception_handlers())  tty->print("!");
2164     // Check this is not the final compiled version
2165     if (C->trap_can_recompile() && depth() == 1) {
2166       tty->print("-");
2167     } else {
2168       tty->print(" ");
2169     }
2170     if( depth() != 1 ) { tty->print("   "); }  // missing compile count
2171     for (int i = 1; i < depth(); ++i) { tty->print("  "); }
2172     method()->print_short_name();
2173     if (is_osr_parse()) {
2174       tty->print(" @ %d", osr_bci());
2175     }
2176     if (ilt->caller_bci() != -1) {
2177       tty->print(" @ %d", ilt->caller_bci());
2178     }
2179     tty->print(" (%d bytes)",method()->code_size());
2180     if (ilt->count_inlines()) {
2181       tty->print(" __inlined %d (%d bytes)", ilt->count_inlines(),
2182                  ilt->count_inline_bcs());
2183     }
2184     tty->cr();
2185   }
2186 }
2187 
2188 
2189 //------------------------------dump-------------------------------------------
2190 // Dump information associated with the bytecodes of current _method
2191 void Parse::dump() {
2192   if( method() != NULL ) {
2193     // Iterate over bytecodes
2194     ciBytecodeStream iter(method());
2195     for( Bytecodes::Code bc = iter.next(); bc != ciBytecodeStream::EOBC() ; bc = iter.next() ) {
2196       dump_bci( iter.cur_bci() );
2197       tty->cr();
2198     }
2199   }
2200 }
2201 
2202 // Dump information associated with a byte code index, 'bci'
2203 void Parse::dump_bci(int bci) {
2204   // Output info on merge-points, cloning, and within _jsr..._ret
2205   // NYI
2206   tty->print(" bci:%d", bci);
2207 }
2208 
2209 #endif
--- EOF ---