1 /*
   2  * Copyright 1997-2007 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  20  * CA 95054 USA or visit www.sun.com if you need additional information or
  21  * have any questions.
  22  *
  23  */
  24 
  25 #include "incls/_precompiled.incl"
  26 #include "incls/_compile.cpp.incl"
  27 
  28 /// Support for intrinsics.
  29 
  30 // Return the index at which m must be inserted (or already exists).
  31 // The sort order is by the address of the ciMethod, with is_virtual as minor key.
  32 int Compile::intrinsic_insertion_index(ciMethod* m, bool is_virtual) {
  33 #ifdef ASSERT
  34   for (int i = 1; i < _intrinsics->length(); i++) {
  35     CallGenerator* cg1 = _intrinsics->at(i-1);
  36     CallGenerator* cg2 = _intrinsics->at(i);
  37     assert(cg1->method() != cg2->method()
  38            ? cg1->method()     < cg2->method()
  39            : cg1->is_virtual() < cg2->is_virtual(),
  40            "compiler intrinsics list must stay sorted");
  41   }
  42 #endif
  43   // Binary search sorted list, in decreasing intervals [lo, hi].
  44   int lo = 0, hi = _intrinsics->length()-1;
  45   while (lo <= hi) {
  46     int mid = (uint)(hi + lo) / 2;
  47     ciMethod* mid_m = _intrinsics->at(mid)->method();
  48     if (m < mid_m) {
  49       hi = mid-1;
  50     } else if (m > mid_m) {
  51       lo = mid+1;
  52     } else {
  53       // look at minor sort key
  54       bool mid_virt = _intrinsics->at(mid)->is_virtual();
  55       if (is_virtual < mid_virt) {
  56         hi = mid-1;
  57       } else if (is_virtual > mid_virt) {
  58         lo = mid+1;
  59       } else {
  60         return mid;  // exact match
  61       }
  62     }
  63   }
  64   return lo;  // inexact match
  65 }
  66 
  67 void Compile::register_intrinsic(CallGenerator* cg) {
  68   if (_intrinsics == NULL) {
  69     _intrinsics = new GrowableArray<CallGenerator*>(60);
  70   }
  71   // This code is stolen from ciObjectFactory::insert.
  72   // Really, GrowableArray should have methods for
  73   // insert_at, remove_at, and binary_search.
  74   int len = _intrinsics->length();
  75   int index = intrinsic_insertion_index(cg->method(), cg->is_virtual());
  76   if (index == len) {
  77     _intrinsics->append(cg);
  78   } else {
  79 #ifdef ASSERT
  80     CallGenerator* oldcg = _intrinsics->at(index);
  81     assert(oldcg->method() != cg->method() || oldcg->is_virtual() != cg->is_virtual(), "don't register twice");
  82 #endif
  83     _intrinsics->append(_intrinsics->at(len-1));
  84     int pos;
  85     for (pos = len-2; pos >= index; pos--) {
  86       _intrinsics->at_put(pos+1,_intrinsics->at(pos));
  87     }
  88     _intrinsics->at_put(index, cg);
  89   }
  90   assert(find_intrinsic(cg->method(), cg->is_virtual()) == cg, "registration worked");
  91 }
  92 
  93 CallGenerator* Compile::find_intrinsic(ciMethod* m, bool is_virtual) {
  94   assert(m->is_loaded(), "don't try this on unloaded methods");
  95   if (_intrinsics != NULL) {
  96     int index = intrinsic_insertion_index(m, is_virtual);
  97     if (index < _intrinsics->length()
  98         && _intrinsics->at(index)->method() == m
  99         && _intrinsics->at(index)->is_virtual() == is_virtual) {
 100       return _intrinsics->at(index);
 101     }
 102   }
 103   // Lazily create intrinsics for intrinsic IDs well-known in the runtime.
 104   if (m->intrinsic_id() != vmIntrinsics::_none) {
 105     CallGenerator* cg = make_vm_intrinsic(m, is_virtual);
 106     if (cg != NULL) {
 107       // Save it for next time:
 108       register_intrinsic(cg);
 109       return cg;
 110     } else {
 111       gather_intrinsic_statistics(m->intrinsic_id(), is_virtual, _intrinsic_disabled);
 112     }
 113   }
 114   return NULL;
 115 }
 116 
 117 // Compile:: register_library_intrinsics and make_vm_intrinsic are defined
 118 // in library_call.cpp.
 119 
 120 
 121 #ifndef PRODUCT
 122 // statistics gathering...
 123 
 124 juint  Compile::_intrinsic_hist_count[vmIntrinsics::ID_LIMIT] = {0};
 125 jubyte Compile::_intrinsic_hist_flags[vmIntrinsics::ID_LIMIT] = {0};
 126 
 127 bool Compile::gather_intrinsic_statistics(vmIntrinsics::ID id, bool is_virtual, int flags) {
 128   assert(id > vmIntrinsics::_none && id < vmIntrinsics::ID_LIMIT, "oob");
 129   int oflags = _intrinsic_hist_flags[id];
 130   assert(flags != 0, "what happened?");
 131   if (is_virtual) {
 132     flags |= _intrinsic_virtual;
 133   }
 134   bool changed = (flags != oflags);
 135   if ((flags & _intrinsic_worked) != 0) {
 136     juint count = (_intrinsic_hist_count[id] += 1);
 137     if (count == 1) {
 138       changed = true;           // first time
 139     }
 140     // increment the overall count also:
 141     _intrinsic_hist_count[vmIntrinsics::_none] += 1;
 142   }
 143   if (changed) {
 144     if (((oflags ^ flags) & _intrinsic_virtual) != 0) {
 145       // Something changed about the intrinsic's virtuality.
 146       if ((flags & _intrinsic_virtual) != 0) {
 147         // This is the first use of this intrinsic as a virtual call.
 148         if (oflags != 0) {
 149           // We already saw it as a non-virtual, so note both cases.
 150           flags |= _intrinsic_both;
 151         }
 152       } else if ((oflags & _intrinsic_both) == 0) {
 153         // This is the first use of this intrinsic as a non-virtual
 154         flags |= _intrinsic_both;
 155       }
 156     }
 157     _intrinsic_hist_flags[id] = (jubyte) (oflags | flags);
 158   }
 159   // update the overall flags also:
 160   _intrinsic_hist_flags[vmIntrinsics::_none] |= (jubyte) flags;
 161   return changed;
 162 }
 163 
 164 static char* format_flags(int flags, char* buf) {
 165   buf[0] = 0;
 166   if ((flags & Compile::_intrinsic_worked) != 0)    strcat(buf, ",worked");
 167   if ((flags & Compile::_intrinsic_failed) != 0)    strcat(buf, ",failed");
 168   if ((flags & Compile::_intrinsic_disabled) != 0)  strcat(buf, ",disabled");
 169   if ((flags & Compile::_intrinsic_virtual) != 0)   strcat(buf, ",virtual");
 170   if ((flags & Compile::_intrinsic_both) != 0)      strcat(buf, ",nonvirtual");
 171   if (buf[0] == 0)  strcat(buf, ",");
 172   assert(buf[0] == ',', "must be");
 173   return &buf[1];
 174 }
 175 
 176 void Compile::print_intrinsic_statistics() {
 177   char flagsbuf[100];
 178   ttyLocker ttyl;
 179   if (xtty != NULL)  xtty->head("statistics type='intrinsic'");
 180   tty->print_cr("Compiler intrinsic usage:");
 181   juint total = _intrinsic_hist_count[vmIntrinsics::_none];
 182   if (total == 0)  total = 1;  // avoid div0 in case of no successes
 183   #define PRINT_STAT_LINE(name, c, f) \
 184     tty->print_cr("  %4d (%4.1f%%) %s (%s)", (int)(c), ((c) * 100.0) / total, name, f);
 185   for (int index = 1 + (int)vmIntrinsics::_none; index < (int)vmIntrinsics::ID_LIMIT; index++) {
 186     vmIntrinsics::ID id = (vmIntrinsics::ID) index;
 187     int   flags = _intrinsic_hist_flags[id];
 188     juint count = _intrinsic_hist_count[id];
 189     if ((flags | count) != 0) {
 190       PRINT_STAT_LINE(vmIntrinsics::name_at(id), count, format_flags(flags, flagsbuf));
 191     }
 192   }
 193   PRINT_STAT_LINE("total", total, format_flags(_intrinsic_hist_flags[vmIntrinsics::_none], flagsbuf));
 194   if (xtty != NULL)  xtty->tail("statistics");
 195 }
 196 
 197 void Compile::print_statistics() {
 198   { ttyLocker ttyl;
 199     if (xtty != NULL)  xtty->head("statistics type='opto'");
 200     Parse::print_statistics();
 201     PhaseCCP::print_statistics();
 202     PhaseRegAlloc::print_statistics();
 203     Scheduling::print_statistics();
 204     PhasePeephole::print_statistics();
 205     PhaseIdealLoop::print_statistics();
 206     if (xtty != NULL)  xtty->tail("statistics");
 207   }
 208   if (_intrinsic_hist_flags[vmIntrinsics::_none] != 0) {
 209     // put this under its own <statistics> element.
 210     print_intrinsic_statistics();
 211   }
 212 }
 213 #endif //PRODUCT
 214 
 215 // Support for bundling info
 216 Bundle* Compile::node_bundling(const Node *n) {
 217   assert(valid_bundle_info(n), "oob");
 218   return &_node_bundling_base[n->_idx];
 219 }
 220 
 221 bool Compile::valid_bundle_info(const Node *n) {
 222   return (_node_bundling_limit > n->_idx);
 223 }
 224 
 225 
 226 // Identify all nodes that are reachable from below, useful.
 227 // Use breadth-first pass that records state in a Unique_Node_List,
 228 // recursive traversal is slower.
 229 void Compile::identify_useful_nodes(Unique_Node_List &useful) {
 230   int estimated_worklist_size = unique();
 231   useful.map( estimated_worklist_size, NULL );  // preallocate space
 232 
 233   // Initialize worklist
 234   if (root() != NULL)     { useful.push(root()); }
 235   // If 'top' is cached, declare it useful to preserve cached node
 236   if( cached_top_node() ) { useful.push(cached_top_node()); }
 237 
 238   // Push all useful nodes onto the list, breadthfirst
 239   for( uint next = 0; next < useful.size(); ++next ) {
 240     assert( next < unique(), "Unique useful nodes < total nodes");
 241     Node *n  = useful.at(next);
 242     uint max = n->len();
 243     for( uint i = 0; i < max; ++i ) {
 244       Node *m = n->in(i);
 245       if( m == NULL ) continue;
 246       useful.push(m);
 247     }
 248   }
 249 }
 250 
 251 // Disconnect all useless nodes by disconnecting those at the boundary.
 252 void Compile::remove_useless_nodes(Unique_Node_List &useful) {
 253   uint next = 0;
 254   while( next < useful.size() ) {
 255     Node *n = useful.at(next++);
 256     // Use raw traversal of out edges since this code removes out edges
 257     int max = n->outcnt();
 258     for (int j = 0; j < max; ++j ) {
 259       Node* child = n->raw_out(j);
 260       if( ! useful.member(child) ) {
 261         assert( !child->is_top() || child != top(),
 262                 "If top is cached in Compile object it is in useful list");
 263         // Only need to remove this out-edge to the useless node
 264         n->raw_del_out(j);
 265         --j;
 266         --max;
 267       }
 268     }
 269     if (n->outcnt() == 1 && n->has_special_unique_user()) {
 270       record_for_igvn( n->unique_out() );
 271     }
 272   }
 273   debug_only(verify_graph_edges(true/*check for no_dead_code*/);)
 274 }
 275 
 276 //------------------------------frame_size_in_words-----------------------------
 277 // frame_slots in units of words
 278 int Compile::frame_size_in_words() const {
 279   // shift is 0 in LP32 and 1 in LP64
 280   const int shift = (LogBytesPerWord - LogBytesPerInt);
 281   int words = _frame_slots >> shift;
 282   assert( words << shift == _frame_slots, "frame size must be properly aligned in LP64" );
 283   return words;
 284 }
 285 
 286 // ============================================================================
 287 //------------------------------CompileWrapper---------------------------------
 288 class CompileWrapper : public StackObj {
 289   Compile *const _compile;
 290  public:
 291   CompileWrapper(Compile* compile);
 292 
 293   ~CompileWrapper();
 294 };
 295 
 296 CompileWrapper::CompileWrapper(Compile* compile) : _compile(compile) {
 297   // the Compile* pointer is stored in the current ciEnv:
 298   ciEnv* env = compile->env();
 299   assert(env == ciEnv::current(), "must already be a ciEnv active");
 300   assert(env->compiler_data() == NULL, "compile already active?");
 301   env->set_compiler_data(compile);
 302   assert(compile == Compile::current(), "sanity");
 303 
 304   compile->set_type_dict(NULL);
 305   compile->set_type_hwm(NULL);
 306   compile->set_type_last_size(0);
 307   compile->set_last_tf(NULL, NULL);
 308   compile->set_indexSet_arena(NULL);
 309   compile->set_indexSet_free_block_list(NULL);
 310   compile->init_type_arena();
 311   Type::Initialize(compile);
 312   _compile->set_scratch_buffer_blob(NULL);
 313   _compile->begin_method();
 314 }
 315 CompileWrapper::~CompileWrapper() {
 316   _compile->end_method();
 317   if (_compile->scratch_buffer_blob() != NULL)
 318     BufferBlob::free(_compile->scratch_buffer_blob());
 319   _compile->env()->set_compiler_data(NULL);
 320 }
 321 
 322 
 323 //----------------------------print_compile_messages---------------------------
 324 void Compile::print_compile_messages() {
 325 #ifndef PRODUCT
 326   // Check if recompiling
 327   if (_subsume_loads == false && PrintOpto) {
 328     // Recompiling without allowing machine instructions to subsume loads
 329     tty->print_cr("*********************************************************");
 330     tty->print_cr("** Bailout: Recompile without subsuming loads          **");
 331     tty->print_cr("*********************************************************");
 332   }
 333   if (_do_escape_analysis != DoEscapeAnalysis && PrintOpto) {
 334     // Recompiling without escape analysis
 335     tty->print_cr("*********************************************************");
 336     tty->print_cr("** Bailout: Recompile without escape analysis          **");
 337     tty->print_cr("*********************************************************");
 338   }
 339   if (env()->break_at_compile()) {
 340     // Open the debugger when compiing this method.
 341     tty->print("### Breaking when compiling: ");
 342     method()->print_short_name();
 343     tty->cr();
 344     BREAKPOINT;
 345   }
 346 
 347   if( PrintOpto ) {
 348     if (is_osr_compilation()) {
 349       tty->print("[OSR]%3d", _compile_id);
 350     } else {
 351       tty->print("%3d", _compile_id);
 352     }
 353   }
 354 #endif
 355 }
 356 
 357 
 358 void Compile::init_scratch_buffer_blob() {
 359   if( scratch_buffer_blob() != NULL )  return;
 360 
 361   // Construct a temporary CodeBuffer to have it construct a BufferBlob
 362   // Cache this BufferBlob for this compile.
 363   ResourceMark rm;
 364   int size = (MAX_inst_size + MAX_stubs_size + MAX_const_size);
 365   BufferBlob* blob = BufferBlob::create("Compile::scratch_buffer", size);
 366   // Record the buffer blob for next time.
 367   set_scratch_buffer_blob(blob);
 368   // Have we run out of code space?
 369   if (scratch_buffer_blob() == NULL) {
 370     // Let CompilerBroker disable further compilations.
 371     record_failure("Not enough space for scratch buffer in CodeCache");
 372     return;
 373   }
 374 
 375   // Initialize the relocation buffers
 376   relocInfo* locs_buf = (relocInfo*) blob->instructions_end() - MAX_locs_size;
 377   set_scratch_locs_memory(locs_buf);
 378 }
 379 
 380 
 381 //-----------------------scratch_emit_size-------------------------------------
 382 // Helper function that computes size by emitting code
 383 uint Compile::scratch_emit_size(const Node* n) {
 384   // Emit into a trash buffer and count bytes emitted.
 385   // This is a pretty expensive way to compute a size,
 386   // but it works well enough if seldom used.
 387   // All common fixed-size instructions are given a size
 388   // method by the AD file.
 389   // Note that the scratch buffer blob and locs memory are
 390   // allocated at the beginning of the compile task, and
 391   // may be shared by several calls to scratch_emit_size.
 392   // The allocation of the scratch buffer blob is particularly
 393   // expensive, since it has to grab the code cache lock.
 394   BufferBlob* blob = this->scratch_buffer_blob();
 395   assert(blob != NULL, "Initialize BufferBlob at start");
 396   assert(blob->size() > MAX_inst_size, "sanity");
 397   relocInfo* locs_buf = scratch_locs_memory();
 398   address blob_begin = blob->instructions_begin();
 399   address blob_end   = (address)locs_buf;
 400   assert(blob->instructions_contains(blob_end), "sanity");
 401   CodeBuffer buf(blob_begin, blob_end - blob_begin);
 402   buf.initialize_consts_size(MAX_const_size);
 403   buf.initialize_stubs_size(MAX_stubs_size);
 404   assert(locs_buf != NULL, "sanity");
 405   int lsize = MAX_locs_size / 2;
 406   buf.insts()->initialize_shared_locs(&locs_buf[0],     lsize);
 407   buf.stubs()->initialize_shared_locs(&locs_buf[lsize], lsize);
 408   n->emit(buf, this->regalloc());
 409   return buf.code_size();
 410 }
 411 
 412 
 413 // ============================================================================
 414 //------------------------------Compile standard-------------------------------
 415 debug_only( int Compile::_debug_idx = 100000; )
 416 
 417 // Compile a method.  entry_bci is -1 for normal compilations and indicates
 418 // the continuation bci for on stack replacement.
 419 
 420 
 421 Compile::Compile( ciEnv* ci_env, C2Compiler* compiler, ciMethod* target, int osr_bci, bool subsume_loads, bool do_escape_analysis )
 422                 : Phase(Compiler),
 423                   _env(ci_env),
 424                   _log(ci_env->log()),
 425                   _compile_id(ci_env->compile_id()),
 426                   _save_argument_registers(false),
 427                   _stub_name(NULL),
 428                   _stub_function(NULL),
 429                   _stub_entry_point(NULL),
 430                   _method(target),
 431                   _entry_bci(osr_bci),
 432                   _initial_gvn(NULL),
 433                   _for_igvn(NULL),
 434                   _warm_calls(NULL),
 435                   _subsume_loads(subsume_loads),
 436                   _do_escape_analysis(do_escape_analysis),
 437                   _failure_reason(NULL),
 438                   _code_buffer("Compile::Fill_buffer"),
 439                   _orig_pc_slot(0),
 440                   _orig_pc_slot_offset_in_bytes(0),
 441                   _node_bundling_limit(0),
 442                   _node_bundling_base(NULL),
 443 #ifndef PRODUCT
 444                   _trace_opto_output(TraceOptoOutput || method()->has_option("TraceOptoOutput")),
 445                   _printer(IdealGraphPrinter::printer()),
 446 #endif
 447                   _congraph(NULL) {
 448   C = this;
 449 
 450   CompileWrapper cw(this);
 451 #ifndef PRODUCT
 452   if (TimeCompiler2) {
 453     tty->print(" ");
 454     target->holder()->name()->print();
 455     tty->print(".");
 456     target->print_short_name();
 457     tty->print("  ");
 458   }
 459   TraceTime t1("Total compilation time", &_t_totalCompilation, TimeCompiler, TimeCompiler2);
 460   TraceTime t2(NULL, &_t_methodCompilation, TimeCompiler, false);
 461   bool print_opto_assembly = PrintOptoAssembly || _method->has_option("PrintOptoAssembly");
 462   if (!print_opto_assembly) {
 463     bool print_assembly = (PrintAssembly || _method->should_print_assembly());
 464     if (print_assembly && !Disassembler::can_decode()) {
 465       tty->print_cr("PrintAssembly request changed to PrintOptoAssembly");
 466       print_opto_assembly = true;
 467     }
 468   }
 469   set_print_assembly(print_opto_assembly);
 470 #endif
 471 
 472   if (ProfileTraps) {
 473     // Make sure the method being compiled gets its own MDO,
 474     // so we can at least track the decompile_count().
 475     method()->build_method_data();
 476   }
 477 
 478   Init(::AliasLevel);
 479 
 480 
 481   print_compile_messages();
 482 
 483   if (UseOldInlining || PrintCompilation NOT_PRODUCT( || PrintOpto) )
 484     _ilt = InlineTree::build_inline_tree_root();
 485   else
 486     _ilt = NULL;
 487 
 488   // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
 489   assert(num_alias_types() >= AliasIdxRaw, "");
 490 
 491 #define MINIMUM_NODE_HASH  1023
 492   // Node list that Iterative GVN will start with
 493   Unique_Node_List for_igvn(comp_arena());
 494   set_for_igvn(&for_igvn);
 495 
 496   // GVN that will be run immediately on new nodes
 497   uint estimated_size = method()->code_size()*4+64;
 498   estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
 499   PhaseGVN gvn(node_arena(), estimated_size);
 500   set_initial_gvn(&gvn);
 501 
 502   { // Scope for timing the parser
 503     TracePhase t3("parse", &_t_parser, true);
 504 
 505     // Put top into the hash table ASAP.
 506     initial_gvn()->transform_no_reclaim(top());
 507 
 508     // Set up tf(), start(), and find a CallGenerator.
 509     CallGenerator* cg;
 510     if (is_osr_compilation()) {
 511       const TypeTuple *domain = StartOSRNode::osr_domain();
 512       const TypeTuple *range = TypeTuple::make_range(method()->signature());
 513       init_tf(TypeFunc::make(domain, range));
 514       StartNode* s = new (this, 2) StartOSRNode(root(), domain);
 515       initial_gvn()->set_type_bottom(s);
 516       init_start(s);
 517       cg = CallGenerator::for_osr(method(), entry_bci());
 518     } else {
 519       // Normal case.
 520       init_tf(TypeFunc::make(method()));
 521       StartNode* s = new (this, 2) StartNode(root(), tf()->domain());
 522       initial_gvn()->set_type_bottom(s);
 523       init_start(s);
 524       float past_uses = method()->interpreter_invocation_count();
 525       float expected_uses = past_uses;
 526       cg = CallGenerator::for_inline(method(), expected_uses);
 527     }
 528     if (failing())  return;
 529     if (cg == NULL) {
 530       record_method_not_compilable_all_tiers("cannot parse method");
 531       return;
 532     }
 533     JVMState* jvms = build_start_state(start(), tf());
 534     if ((jvms = cg->generate(jvms)) == NULL) {
 535       record_method_not_compilable("method parse failed");
 536       return;
 537     }
 538     GraphKit kit(jvms);
 539 
 540     if (!kit.stopped()) {
 541       // Accept return values, and transfer control we know not where.
 542       // This is done by a special, unique ReturnNode bound to root.
 543       return_values(kit.jvms());
 544     }
 545 
 546     if (kit.has_exceptions()) {
 547       // Any exceptions that escape from this call must be rethrown
 548       // to whatever caller is dynamically above us on the stack.
 549       // This is done by a special, unique RethrowNode bound to root.
 550       rethrow_exceptions(kit.transfer_exceptions_into_jvms());
 551     }
 552 
 553     // Remove clutter produced by parsing.
 554     if (!failing()) {
 555       ResourceMark rm;
 556       PhaseRemoveUseless pru(initial_gvn(), &for_igvn);
 557     }
 558   }
 559 
 560   // Note:  Large methods are capped off in do_one_bytecode().
 561   if (failing())  return;
 562 
 563   // After parsing, node notes are no longer automagic.
 564   // They must be propagated by register_new_node_with_optimizer(),
 565   // clone(), or the like.
 566   set_default_node_notes(NULL);
 567 
 568   for (;;) {
 569     int successes = Inline_Warm();
 570     if (failing())  return;
 571     if (successes == 0)  break;
 572   }
 573 
 574   // Drain the list.
 575   Finish_Warm();
 576 #ifndef PRODUCT
 577   if (_printer) {
 578     _printer->print_inlining(this);
 579   }
 580 #endif
 581 
 582   if (failing())  return;
 583   NOT_PRODUCT( verify_graph_edges(); )
 584 
 585   // Perform escape analysis
 586   if (_do_escape_analysis)
 587     _congraph = new ConnectionGraph(this);
 588   if (_congraph != NULL) {
 589     NOT_PRODUCT( TracePhase t2("escapeAnalysis", &_t_escapeAnalysis, TimeCompiler); )
 590     _congraph->compute_escape();
 591     if (failing())  return;
 592 
 593 #ifndef PRODUCT
 594     if (PrintEscapeAnalysis) {
 595       _congraph->dump();
 596     }
 597 #endif
 598   }
 599   // Now optimize
 600   Optimize();
 601   if (failing())  return;
 602   NOT_PRODUCT( verify_graph_edges(); )
 603 
 604   print_method("Before Matching");
 605 
 606 #ifndef PRODUCT
 607   if (PrintIdeal) {
 608     ttyLocker ttyl;  // keep the following output all in one block
 609     // This output goes directly to the tty, not the compiler log.
 610     // To enable tools to match it up with the compilation activity,
 611     // be sure to tag this tty output with the compile ID.
 612     if (xtty != NULL) {
 613       xtty->head("ideal compile_id='%d'%s", compile_id(),
 614                  is_osr_compilation()    ? " compile_kind='osr'" :
 615                  "");
 616     }
 617     root()->dump(9999);
 618     if (xtty != NULL) {
 619       xtty->tail("ideal");
 620     }
 621   }
 622 #endif
 623 
 624   // Now that we know the size of all the monitors we can add a fixed slot
 625   // for the original deopt pc.
 626 
 627   _orig_pc_slot =  fixed_slots();
 628   int next_slot = _orig_pc_slot + (sizeof(address) / VMRegImpl::stack_slot_size);
 629   set_fixed_slots(next_slot);
 630 
 631   // Now generate code
 632   Code_Gen();
 633   if (failing())  return;
 634 
 635   // Check if we want to skip execution of all compiled code.
 636   {
 637 #ifndef PRODUCT
 638     if (OptoNoExecute) {
 639       record_method_not_compilable("+OptoNoExecute");  // Flag as failed
 640       return;
 641     }
 642     TracePhase t2("install_code", &_t_registerMethod, TimeCompiler);
 643 #endif
 644 
 645     if (is_osr_compilation()) {
 646       _code_offsets.set_value(CodeOffsets::Verified_Entry, 0);
 647       _code_offsets.set_value(CodeOffsets::OSR_Entry, _first_block_size);
 648     } else {
 649       _code_offsets.set_value(CodeOffsets::Verified_Entry, _first_block_size);
 650       _code_offsets.set_value(CodeOffsets::OSR_Entry, 0);
 651     }
 652 
 653     env()->register_method(_method, _entry_bci,
 654                            &_code_offsets,
 655                            _orig_pc_slot_offset_in_bytes,
 656                            code_buffer(),
 657                            frame_size_in_words(), _oop_map_set,
 658                            &_handler_table, &_inc_table,
 659                            compiler,
 660                            env()->comp_level(),
 661                            true, /*has_debug_info*/
 662                            has_unsafe_access()
 663                            );
 664   }
 665 }
 666 
 667 //------------------------------Compile----------------------------------------
 668 // Compile a runtime stub
 669 Compile::Compile( ciEnv* ci_env,
 670                   TypeFunc_generator generator,
 671                   address stub_function,
 672                   const char *stub_name,
 673                   int is_fancy_jump,
 674                   bool pass_tls,
 675                   bool save_arg_registers,
 676                   bool return_pc )
 677   : Phase(Compiler),
 678     _env(ci_env),
 679     _log(ci_env->log()),
 680     _compile_id(-1),
 681     _save_argument_registers(save_arg_registers),
 682     _method(NULL),
 683     _stub_name(stub_name),
 684     _stub_function(stub_function),
 685     _stub_entry_point(NULL),
 686     _entry_bci(InvocationEntryBci),
 687     _initial_gvn(NULL),
 688     _for_igvn(NULL),
 689     _warm_calls(NULL),
 690     _orig_pc_slot(0),
 691     _orig_pc_slot_offset_in_bytes(0),
 692     _subsume_loads(true),
 693     _do_escape_analysis(false),
 694     _failure_reason(NULL),
 695     _code_buffer("Compile::Fill_buffer"),
 696     _node_bundling_limit(0),
 697     _node_bundling_base(NULL),
 698 #ifndef PRODUCT
 699     _trace_opto_output(TraceOptoOutput),
 700     _printer(NULL),
 701 #endif
 702     _congraph(NULL) {
 703   C = this;
 704 
 705 #ifndef PRODUCT
 706   TraceTime t1(NULL, &_t_totalCompilation, TimeCompiler, false);
 707   TraceTime t2(NULL, &_t_stubCompilation, TimeCompiler, false);
 708   set_print_assembly(PrintFrameConverterAssembly);
 709 #endif
 710   CompileWrapper cw(this);
 711   Init(/*AliasLevel=*/ 0);
 712   init_tf((*generator)());
 713 
 714   {
 715     // The following is a dummy for the sake of GraphKit::gen_stub
 716     Unique_Node_List for_igvn(comp_arena());
 717     set_for_igvn(&for_igvn);  // not used, but some GraphKit guys push on this
 718     PhaseGVN gvn(Thread::current()->resource_area(),255);
 719     set_initial_gvn(&gvn);    // not significant, but GraphKit guys use it pervasively
 720     gvn.transform_no_reclaim(top());
 721 
 722     GraphKit kit;
 723     kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
 724   }
 725 
 726   NOT_PRODUCT( verify_graph_edges(); )
 727   Code_Gen();
 728   if (failing())  return;
 729 
 730 
 731   // Entry point will be accessed using compile->stub_entry_point();
 732   if (code_buffer() == NULL) {
 733     Matcher::soft_match_failure();
 734   } else {
 735     if (PrintAssembly && (WizardMode || Verbose))
 736       tty->print_cr("### Stub::%s", stub_name);
 737 
 738     if (!failing()) {
 739       assert(_fixed_slots == 0, "no fixed slots used for runtime stubs");
 740 
 741       // Make the NMethod
 742       // For now we mark the frame as never safe for profile stackwalking
 743       RuntimeStub *rs = RuntimeStub::new_runtime_stub(stub_name,
 744                                                       code_buffer(),
 745                                                       CodeOffsets::frame_never_safe,
 746                                                       // _code_offsets.value(CodeOffsets::Frame_Complete),
 747                                                       frame_size_in_words(),
 748                                                       _oop_map_set,
 749                                                       save_arg_registers);
 750       assert(rs != NULL && rs->is_runtime_stub(), "sanity check");
 751 
 752       _stub_entry_point = rs->entry_point();
 753     }
 754   }
 755 }
 756 
 757 #ifndef PRODUCT
 758 void print_opto_verbose_signature( const TypeFunc *j_sig, const char *stub_name ) {
 759   if(PrintOpto && Verbose) {
 760     tty->print("%s   ", stub_name); j_sig->print_flattened(); tty->cr();
 761   }
 762 }
 763 #endif
 764 
 765 void Compile::print_codes() {
 766 }
 767 
 768 //------------------------------Init-------------------------------------------
 769 // Prepare for a single compilation
 770 void Compile::Init(int aliaslevel) {
 771   _unique  = 0;
 772   _regalloc = NULL;
 773 
 774   _tf      = NULL;  // filled in later
 775   _top     = NULL;  // cached later
 776   _matcher = NULL;  // filled in later
 777   _cfg     = NULL;  // filled in later
 778 
 779   set_24_bit_selection_and_mode(Use24BitFP, false);
 780 
 781   _node_note_array = NULL;
 782   _default_node_notes = NULL;
 783 
 784   _immutable_memory = NULL; // filled in at first inquiry
 785 
 786   // Globally visible Nodes
 787   // First set TOP to NULL to give safe behavior during creation of RootNode
 788   set_cached_top_node(NULL);
 789   set_root(new (this, 3) RootNode());
 790   // Now that you have a Root to point to, create the real TOP
 791   set_cached_top_node( new (this, 1) ConNode(Type::TOP) );
 792   set_recent_alloc(NULL, NULL);
 793 
 794   // Create Debug Information Recorder to record scopes, oopmaps, etc.
 795   env()->set_oop_recorder(new OopRecorder(comp_arena()));
 796   env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
 797   env()->set_dependencies(new Dependencies(env()));
 798 
 799   _fixed_slots = 0;
 800   set_has_split_ifs(false);
 801   set_has_loops(has_method() && method()->has_loops()); // first approximation
 802   _deopt_happens = true;  // start out assuming the worst
 803   _trap_can_recompile = false;  // no traps emitted yet
 804   _major_progress = true; // start out assuming good things will happen
 805   set_has_unsafe_access(false);
 806   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
 807   set_decompile_count(0);
 808 
 809   // Compilation level related initialization
 810   if (env()->comp_level() == CompLevel_fast_compile) {
 811     set_num_loop_opts(Tier1LoopOptsCount);
 812     set_do_inlining(Tier1Inline != 0);
 813     set_max_inline_size(Tier1MaxInlineSize);
 814     set_freq_inline_size(Tier1FreqInlineSize);
 815     set_do_scheduling(false);
 816     set_do_count_invocations(Tier1CountInvocations);
 817     set_do_method_data_update(Tier1UpdateMethodData);
 818   } else {
 819     assert(env()->comp_level() == CompLevel_full_optimization, "unknown comp level");
 820     set_num_loop_opts(LoopOptsCount);
 821     set_do_inlining(Inline);
 822     set_max_inline_size(MaxInlineSize);
 823     set_freq_inline_size(FreqInlineSize);
 824     set_do_scheduling(OptoScheduling);
 825     set_do_count_invocations(false);
 826     set_do_method_data_update(false);
 827   }
 828 
 829   if (debug_info()->recording_non_safepoints()) {
 830     set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
 831                         (comp_arena(), 8, 0, NULL));
 832     set_default_node_notes(Node_Notes::make(this));
 833   }
 834 
 835   // // -- Initialize types before each compile --
 836   // // Update cached type information
 837   // if( _method && _method->constants() )
 838   //   Type::update_loaded_types(_method, _method->constants());
 839 
 840   // Init alias_type map.
 841   if (!_do_escape_analysis && aliaslevel == 3)
 842     aliaslevel = 2;  // No unique types without escape analysis
 843   _AliasLevel = aliaslevel;
 844   const int grow_ats = 16;
 845   _max_alias_types = grow_ats;
 846   _alias_types   = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
 847   AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType,  grow_ats);
 848   Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
 849   {
 850     for (int i = 0; i < grow_ats; i++)  _alias_types[i] = &ats[i];
 851   }
 852   // Initialize the first few types.
 853   _alias_types[AliasIdxTop]->Init(AliasIdxTop, NULL);
 854   _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
 855   _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
 856   _num_alias_types = AliasIdxRaw+1;
 857   // Zero out the alias type cache.
 858   Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
 859   // A NULL adr_type hits in the cache right away.  Preload the right answer.
 860   probe_alias_cache(NULL)->_index = AliasIdxTop;
 861 
 862   _intrinsics = NULL;
 863   _macro_nodes = new GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
 864   register_library_intrinsics();
 865 }
 866 
 867 //---------------------------init_start----------------------------------------
 868 // Install the StartNode on this compile object.
 869 void Compile::init_start(StartNode* s) {
 870   if (failing())
 871     return; // already failing
 872   assert(s == start(), "");
 873 }
 874 
 875 StartNode* Compile::start() const {
 876   assert(!failing(), "");
 877   for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
 878     Node* start = root()->fast_out(i);
 879     if( start->is_Start() )
 880       return start->as_Start();
 881   }
 882   ShouldNotReachHere();
 883   return NULL;
 884 }
 885 
 886 //-------------------------------immutable_memory-------------------------------------
 887 // Access immutable memory
 888 Node* Compile::immutable_memory() {
 889   if (_immutable_memory != NULL) {
 890     return _immutable_memory;
 891   }
 892   StartNode* s = start();
 893   for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
 894     Node *p = s->fast_out(i);
 895     if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
 896       _immutable_memory = p;
 897       return _immutable_memory;
 898     }
 899   }
 900   ShouldNotReachHere();
 901   return NULL;
 902 }
 903 
 904 //----------------------set_cached_top_node------------------------------------
 905 // Install the cached top node, and make sure Node::is_top works correctly.
 906 void Compile::set_cached_top_node(Node* tn) {
 907   if (tn != NULL)  verify_top(tn);
 908   Node* old_top = _top;
 909   _top = tn;
 910   // Calling Node::setup_is_top allows the nodes the chance to adjust
 911   // their _out arrays.
 912   if (_top != NULL)     _top->setup_is_top();
 913   if (old_top != NULL)  old_top->setup_is_top();
 914   assert(_top == NULL || top()->is_top(), "");
 915 }
 916 
 917 #ifndef PRODUCT
 918 void Compile::verify_top(Node* tn) const {
 919   if (tn != NULL) {
 920     assert(tn->is_Con(), "top node must be a constant");
 921     assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
 922     assert(tn->in(0) != NULL, "must have live top node");
 923   }
 924 }
 925 #endif
 926 
 927 
 928 ///-------------------Managing Per-Node Debug & Profile Info-------------------
 929 
 930 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
 931   guarantee(arr != NULL, "");
 932   int num_blocks = arr->length();
 933   if (grow_by < num_blocks)  grow_by = num_blocks;
 934   int num_notes = grow_by * _node_notes_block_size;
 935   Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
 936   Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
 937   while (num_notes > 0) {
 938     arr->append(notes);
 939     notes     += _node_notes_block_size;
 940     num_notes -= _node_notes_block_size;
 941   }
 942   assert(num_notes == 0, "exact multiple, please");
 943 }
 944 
 945 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
 946   if (source == NULL || dest == NULL)  return false;
 947 
 948   if (dest->is_Con())
 949     return false;               // Do not push debug info onto constants.
 950 
 951 #ifdef ASSERT
 952   // Leave a bread crumb trail pointing to the original node:
 953   if (dest != NULL && dest != source && dest->debug_orig() == NULL) {
 954     dest->set_debug_orig(source);
 955   }
 956 #endif
 957 
 958   if (node_note_array() == NULL)
 959     return false;               // Not collecting any notes now.
 960 
 961   // This is a copy onto a pre-existing node, which may already have notes.
 962   // If both nodes have notes, do not overwrite any pre-existing notes.
 963   Node_Notes* source_notes = node_notes_at(source->_idx);
 964   if (source_notes == NULL || source_notes->is_clear())  return false;
 965   Node_Notes* dest_notes   = node_notes_at(dest->_idx);
 966   if (dest_notes == NULL || dest_notes->is_clear()) {
 967     return set_node_notes_at(dest->_idx, source_notes);
 968   }
 969 
 970   Node_Notes merged_notes = (*source_notes);
 971   // The order of operations here ensures that dest notes will win...
 972   merged_notes.update_from(dest_notes);
 973   return set_node_notes_at(dest->_idx, &merged_notes);
 974 }
 975 
 976 
 977 //--------------------------allow_range_check_smearing-------------------------
 978 // Gating condition for coalescing similar range checks.
 979 // Sometimes we try 'speculatively' replacing a series of a range checks by a
 980 // single covering check that is at least as strong as any of them.
 981 // If the optimization succeeds, the simplified (strengthened) range check
 982 // will always succeed.  If it fails, we will deopt, and then give up
 983 // on the optimization.
 984 bool Compile::allow_range_check_smearing() const {
 985   // If this method has already thrown a range-check,
 986   // assume it was because we already tried range smearing
 987   // and it failed.
 988   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
 989   return !already_trapped;
 990 }
 991 
 992 
 993 //------------------------------flatten_alias_type-----------------------------
 994 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
 995   int offset = tj->offset();
 996   TypePtr::PTR ptr = tj->ptr();
 997 
 998   // Process weird unsafe references.
 999   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
1000     assert(InlineUnsafeOps, "indeterminate pointers come only from unsafe ops");
1001     tj = TypeOopPtr::BOTTOM;
1002     ptr = tj->ptr();
1003     offset = tj->offset();
1004   }
1005 
1006   // Array pointers need some flattening
1007   const TypeAryPtr *ta = tj->isa_aryptr();
1008   if( ta && _AliasLevel >= 2 ) {
1009     // For arrays indexed by constant indices, we flatten the alias
1010     // space to include all of the array body.  Only the header, klass
1011     // and array length can be accessed un-aliased.
1012     if( offset != Type::OffsetBot ) {
1013       if( ta->const_oop() ) { // methodDataOop or methodOop
1014         offset = Type::OffsetBot;   // Flatten constant access into array body
1015         tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),ta->ary(),ta->klass(),false,Type::OffsetBot, ta->instance_id());
1016       } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
1017         // range is OK as-is.
1018         tj = ta = TypeAryPtr::RANGE;
1019       } else if( offset == oopDesc::klass_offset_in_bytes() ) {
1020         tj = TypeInstPtr::KLASS; // all klass loads look alike
1021         ta = TypeAryPtr::RANGE; // generic ignored junk
1022         ptr = TypePtr::BotPTR;
1023       } else if( offset == oopDesc::mark_offset_in_bytes() ) {
1024         tj = TypeInstPtr::MARK;
1025         ta = TypeAryPtr::RANGE; // generic ignored junk
1026         ptr = TypePtr::BotPTR;
1027       } else {                  // Random constant offset into array body
1028         offset = Type::OffsetBot;   // Flatten constant access into array body
1029         tj = ta = TypeAryPtr::make(ptr,ta->ary(),ta->klass(),false,Type::OffsetBot, ta->instance_id());
1030       }
1031     }
1032     // Arrays of fixed size alias with arrays of unknown size.
1033     if (ta->size() != TypeInt::POS) {
1034       const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
1035       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,ta->klass(),false,offset, ta->instance_id());
1036     }
1037     // Arrays of known objects become arrays of unknown objects.
1038     if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
1039       const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
1040       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset, ta->instance_id());
1041     }
1042     if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
1043       const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
1044       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset, ta->instance_id());
1045     }
1046     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
1047     // cannot be distinguished by bytecode alone.
1048     if (ta->elem() == TypeInt::BOOL) {
1049       const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
1050       ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
1051       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,offset, ta->instance_id());
1052     }
1053     // During the 2nd round of IterGVN, NotNull castings are removed.
1054     // Make sure the Bottom and NotNull variants alias the same.
1055     // Also, make sure exact and non-exact variants alias the same.
1056     if( ptr == TypePtr::NotNull || ta->klass_is_exact() ) {
1057       if (ta->const_oop()) {
1058         tj = ta = TypeAryPtr::make(TypePtr::Constant,ta->const_oop(),ta->ary(),ta->klass(),false,offset);
1059       } else {
1060         tj = ta = TypeAryPtr::make(TypePtr::BotPTR,ta->ary(),ta->klass(),false,offset);
1061       }
1062     }
1063   }
1064 
1065   // Oop pointers need some flattening
1066   const TypeInstPtr *to = tj->isa_instptr();
1067   if( to && _AliasLevel >= 2 && to != TypeOopPtr::BOTTOM ) {
1068     if( ptr == TypePtr::Constant ) {
1069       // No constant oop pointers (such as Strings); they alias with
1070       // unknown strings.
1071       tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1072     } else if( to->is_instance_field() ) {
1073       tj = to; // Keep NotNull and klass_is_exact for instance type
1074     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
1075       // During the 2nd round of IterGVN, NotNull castings are removed.
1076       // Make sure the Bottom and NotNull variants alias the same.
1077       // Also, make sure exact and non-exact variants alias the same.
1078       tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset, to->instance_id());
1079     }
1080     // Canonicalize the holder of this field
1081     ciInstanceKlass *k = to->klass()->as_instance_klass();
1082     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
1083       // First handle header references such as a LoadKlassNode, even if the
1084       // object's klass is unloaded at compile time (4965979).
1085       tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, NULL, offset, to->instance_id());
1086     } else if (offset < 0 || offset >= k->size_helper() * wordSize) {
1087       to = NULL;
1088       tj = TypeOopPtr::BOTTOM;
1089       offset = tj->offset();
1090     } else {
1091       ciInstanceKlass *canonical_holder = k->get_canonical_holder(offset);
1092       if (!k->equals(canonical_holder) || tj->offset() != offset) {
1093         tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, false, NULL, offset, to->instance_id());
1094       }
1095     }
1096   }
1097 
1098   // Klass pointers to object array klasses need some flattening
1099   const TypeKlassPtr *tk = tj->isa_klassptr();
1100   if( tk ) {
1101     // If we are referencing a field within a Klass, we need
1102     // to assume the worst case of an Object.  Both exact and
1103     // inexact types must flatten to the same alias class.
1104     // Since the flattened result for a klass is defined to be
1105     // precisely java.lang.Object, use a constant ptr.
1106     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
1107 
1108       tj = tk = TypeKlassPtr::make(TypePtr::Constant,
1109                                    TypeKlassPtr::OBJECT->klass(),
1110                                    offset);
1111     }
1112 
1113     ciKlass* klass = tk->klass();
1114     if( klass->is_obj_array_klass() ) {
1115       ciKlass* k = TypeAryPtr::OOPS->klass();
1116       if( !k || !k->is_loaded() )                  // Only fails for some -Xcomp runs
1117         k = TypeInstPtr::BOTTOM->klass();
1118       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, k, offset );
1119     }
1120 
1121     // Check for precise loads from the primary supertype array and force them
1122     // to the supertype cache alias index.  Check for generic array loads from
1123     // the primary supertype array and also force them to the supertype cache
1124     // alias index.  Since the same load can reach both, we need to merge
1125     // these 2 disparate memories into the same alias class.  Since the
1126     // primary supertype array is read-only, there's no chance of confusion
1127     // where we bypass an array load and an array store.
1128     uint off2 = offset - Klass::primary_supers_offset_in_bytes();
1129     if( offset == Type::OffsetBot ||
1130         off2 < Klass::primary_super_limit()*wordSize ) {
1131       offset = sizeof(oopDesc) +Klass::secondary_super_cache_offset_in_bytes();
1132       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, tk->klass(), offset );
1133     }
1134   }
1135 
1136   // Flatten all Raw pointers together.
1137   if (tj->base() == Type::RawPtr)
1138     tj = TypeRawPtr::BOTTOM;
1139 
1140   if (tj->base() == Type::AnyPtr)
1141     tj = TypePtr::BOTTOM;      // An error, which the caller must check for.
1142 
1143   // Flatten all to bottom for now
1144   switch( _AliasLevel ) {
1145   case 0:
1146     tj = TypePtr::BOTTOM;
1147     break;
1148   case 1:                       // Flatten to: oop, static, field or array
1149     switch (tj->base()) {
1150     //case Type::AryPtr: tj = TypeAryPtr::RANGE;    break;
1151     case Type::RawPtr:   tj = TypeRawPtr::BOTTOM;   break;
1152     case Type::AryPtr:   // do not distinguish arrays at all
1153     case Type::InstPtr:  tj = TypeInstPtr::BOTTOM;  break;
1154     case Type::KlassPtr: tj = TypeKlassPtr::OBJECT; break;
1155     case Type::AnyPtr:   tj = TypePtr::BOTTOM;      break;  // caller checks it
1156     default: ShouldNotReachHere();
1157     }
1158     break;
1159   case 2:                       // No collasping at level 2; keep all splits
1160   case 3:                       // No collasping at level 3; keep all splits
1161     break;
1162   default:
1163     Unimplemented();
1164   }
1165 
1166   offset = tj->offset();
1167   assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
1168 
1169   assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
1170           (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
1171           (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
1172           (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
1173           (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1174           (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1175           (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr)  ,
1176           "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
1177   assert( tj->ptr() != TypePtr::TopPTR &&
1178           tj->ptr() != TypePtr::AnyNull &&
1179           tj->ptr() != TypePtr::Null, "No imprecise addresses" );
1180 //    assert( tj->ptr() != TypePtr::Constant ||
1181 //            tj->base() == Type::RawPtr ||
1182 //            tj->base() == Type::KlassPtr, "No constant oop addresses" );
1183 
1184   return tj;
1185 }
1186 
1187 void Compile::AliasType::Init(int i, const TypePtr* at) {
1188   _index = i;
1189   _adr_type = at;
1190   _field = NULL;
1191   _is_rewritable = true; // default
1192   const TypeOopPtr *atoop = (at != NULL) ? at->isa_oopptr() : NULL;
1193   if (atoop != NULL && atoop->is_instance()) {
1194     const TypeOopPtr *gt = atoop->cast_to_instance(TypeOopPtr::UNKNOWN_INSTANCE);
1195     _general_index = Compile::current()->get_alias_index(gt);
1196   } else {
1197     _general_index = 0;
1198   }
1199 }
1200 
1201 //---------------------------------print_on------------------------------------
1202 #ifndef PRODUCT
1203 void Compile::AliasType::print_on(outputStream* st) {
1204   if (index() < 10)
1205         st->print("@ <%d> ", index());
1206   else  st->print("@ <%d>",  index());
1207   st->print(is_rewritable() ? "   " : " RO");
1208   int offset = adr_type()->offset();
1209   if (offset == Type::OffsetBot)
1210         st->print(" +any");
1211   else  st->print(" +%-3d", offset);
1212   st->print(" in ");
1213   adr_type()->dump_on(st);
1214   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
1215   if (field() != NULL && tjp) {
1216     if (tjp->klass()  != field()->holder() ||
1217         tjp->offset() != field()->offset_in_bytes()) {
1218       st->print(" != ");
1219       field()->print();
1220       st->print(" ***");
1221     }
1222   }
1223 }
1224 
1225 void print_alias_types() {
1226   Compile* C = Compile::current();
1227   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
1228   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
1229     C->alias_type(idx)->print_on(tty);
1230     tty->cr();
1231   }
1232 }
1233 #endif
1234 
1235 
1236 //----------------------------probe_alias_cache--------------------------------
1237 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
1238   intptr_t key = (intptr_t) adr_type;
1239   key ^= key >> logAliasCacheSize;
1240   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
1241 }
1242 
1243 
1244 //-----------------------------grow_alias_types--------------------------------
1245 void Compile::grow_alias_types() {
1246   const int old_ats  = _max_alias_types; // how many before?
1247   const int new_ats  = old_ats;          // how many more?
1248   const int grow_ats = old_ats+new_ats;  // how many now?
1249   _max_alias_types = grow_ats;
1250   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
1251   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
1252   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
1253   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
1254 }
1255 
1256 
1257 //--------------------------------find_alias_type------------------------------
1258 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create) {
1259   if (_AliasLevel == 0)
1260     return alias_type(AliasIdxBot);
1261 
1262   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1263   if (ace->_adr_type == adr_type) {
1264     return alias_type(ace->_index);
1265   }
1266 
1267   // Handle special cases.
1268   if (adr_type == NULL)             return alias_type(AliasIdxTop);
1269   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
1270 
1271   // Do it the slow way.
1272   const TypePtr* flat = flatten_alias_type(adr_type);
1273 
1274 #ifdef ASSERT
1275   assert(flat == flatten_alias_type(flat), "idempotent");
1276   assert(flat != TypePtr::BOTTOM,     "cannot alias-analyze an untyped ptr");
1277   if (flat->isa_oopptr() && !flat->isa_klassptr()) {
1278     const TypeOopPtr* foop = flat->is_oopptr();
1279     const TypePtr* xoop = foop->cast_to_exactness(!foop->klass_is_exact())->is_ptr();
1280     assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type");
1281   }
1282   assert(flat == flatten_alias_type(flat), "exact bit doesn't matter");
1283 #endif
1284 
1285   int idx = AliasIdxTop;
1286   for (int i = 0; i < num_alias_types(); i++) {
1287     if (alias_type(i)->adr_type() == flat) {
1288       idx = i;
1289       break;
1290     }
1291   }
1292 
1293   if (idx == AliasIdxTop) {
1294     if (no_create)  return NULL;
1295     // Grow the array if necessary.
1296     if (_num_alias_types == _max_alias_types)  grow_alias_types();
1297     // Add a new alias type.
1298     idx = _num_alias_types++;
1299     _alias_types[idx]->Init(idx, flat);
1300     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
1301     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
1302     if (flat->isa_instptr()) {
1303       if (flat->offset() == java_lang_Class::klass_offset_in_bytes()
1304           && flat->is_instptr()->klass() == env()->Class_klass())
1305         alias_type(idx)->set_rewritable(false);
1306     }
1307     if (flat->isa_klassptr()) {
1308       if (flat->offset() == Klass::super_check_offset_offset_in_bytes() + (int)sizeof(oopDesc))
1309         alias_type(idx)->set_rewritable(false);
1310       if (flat->offset() == Klass::modifier_flags_offset_in_bytes() + (int)sizeof(oopDesc))
1311         alias_type(idx)->set_rewritable(false);
1312       if (flat->offset() == Klass::access_flags_offset_in_bytes() + (int)sizeof(oopDesc))
1313         alias_type(idx)->set_rewritable(false);
1314       if (flat->offset() == Klass::java_mirror_offset_in_bytes() + (int)sizeof(oopDesc))
1315         alias_type(idx)->set_rewritable(false);
1316     }
1317     // %%% (We would like to finalize JavaThread::threadObj_offset(),
1318     // but the base pointer type is not distinctive enough to identify
1319     // references into JavaThread.)
1320 
1321     // Check for final instance fields.
1322     const TypeInstPtr* tinst = flat->isa_instptr();
1323     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
1324       ciInstanceKlass *k = tinst->klass()->as_instance_klass();
1325       ciField* field = k->get_field_by_offset(tinst->offset(), false);
1326       // Set field() and is_rewritable() attributes.
1327       if (field != NULL)  alias_type(idx)->set_field(field);
1328     }
1329     const TypeKlassPtr* tklass = flat->isa_klassptr();
1330     // Check for final static fields.
1331     if (tklass && tklass->klass()->is_instance_klass()) {
1332       ciInstanceKlass *k = tklass->klass()->as_instance_klass();
1333       ciField* field = k->get_field_by_offset(tklass->offset(), true);
1334       // Set field() and is_rewritable() attributes.
1335       if (field != NULL)   alias_type(idx)->set_field(field);
1336     }
1337   }
1338 
1339   // Fill the cache for next time.
1340   ace->_adr_type = adr_type;
1341   ace->_index    = idx;
1342   assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
1343 
1344   // Might as well try to fill the cache for the flattened version, too.
1345   AliasCacheEntry* face = probe_alias_cache(flat);
1346   if (face->_adr_type == NULL) {
1347     face->_adr_type = flat;
1348     face->_index    = idx;
1349     assert(alias_type(flat) == alias_type(idx), "flat type must work too");
1350   }
1351 
1352   return alias_type(idx);
1353 }
1354 
1355 
1356 Compile::AliasType* Compile::alias_type(ciField* field) {
1357   const TypeOopPtr* t;
1358   if (field->is_static())
1359     t = TypeKlassPtr::make(field->holder());
1360   else
1361     t = TypeOopPtr::make_from_klass_raw(field->holder());
1362   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()));
1363   assert(field->is_final() == !atp->is_rewritable(), "must get the rewritable bits correct");
1364   return atp;
1365 }
1366 
1367 
1368 //------------------------------have_alias_type--------------------------------
1369 bool Compile::have_alias_type(const TypePtr* adr_type) {
1370   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1371   if (ace->_adr_type == adr_type) {
1372     return true;
1373   }
1374 
1375   // Handle special cases.
1376   if (adr_type == NULL)             return true;
1377   if (adr_type == TypePtr::BOTTOM)  return true;
1378 
1379   return find_alias_type(adr_type, true) != NULL;
1380 }
1381 
1382 //-----------------------------must_alias--------------------------------------
1383 // True if all values of the given address type are in the given alias category.
1384 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
1385   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1386   if (adr_type == NULL)                 return true;  // NULL serves as TypePtr::TOP
1387   if (alias_idx == AliasIdxTop)         return false; // the empty category
1388   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
1389 
1390   // the only remaining possible overlap is identity
1391   int adr_idx = get_alias_index(adr_type);
1392   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1393   assert(adr_idx == alias_idx ||
1394          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
1395           && adr_type                       != TypeOopPtr::BOTTOM),
1396          "should not be testing for overlap with an unsafe pointer");
1397   return adr_idx == alias_idx;
1398 }
1399 
1400 //------------------------------can_alias--------------------------------------
1401 // True if any values of the given address type are in the given alias category.
1402 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
1403   if (alias_idx == AliasIdxTop)         return false; // the empty category
1404   if (adr_type == NULL)                 return false; // NULL serves as TypePtr::TOP
1405   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1406   if (adr_type->base() == Type::AnyPtr) return true;  // TypePtr::BOTTOM or its twins
1407 
1408   // the only remaining possible overlap is identity
1409   int adr_idx = get_alias_index(adr_type);
1410   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1411   return adr_idx == alias_idx;
1412 }
1413 
1414 
1415 
1416 //---------------------------pop_warm_call-------------------------------------
1417 WarmCallInfo* Compile::pop_warm_call() {
1418   WarmCallInfo* wci = _warm_calls;
1419   if (wci != NULL)  _warm_calls = wci->remove_from(wci);
1420   return wci;
1421 }
1422 
1423 //----------------------------Inline_Warm--------------------------------------
1424 int Compile::Inline_Warm() {
1425   // If there is room, try to inline some more warm call sites.
1426   // %%% Do a graph index compaction pass when we think we're out of space?
1427   if (!InlineWarmCalls)  return 0;
1428 
1429   int calls_made_hot = 0;
1430   int room_to_grow   = NodeCountInliningCutoff - unique();
1431   int amount_to_grow = MIN2(room_to_grow, (int)NodeCountInliningStep);
1432   int amount_grown   = 0;
1433   WarmCallInfo* call;
1434   while (amount_to_grow > 0 && (call = pop_warm_call()) != NULL) {
1435     int est_size = (int)call->size();
1436     if (est_size > (room_to_grow - amount_grown)) {
1437       // This one won't fit anyway.  Get rid of it.
1438       call->make_cold();
1439       continue;
1440     }
1441     call->make_hot();
1442     calls_made_hot++;
1443     amount_grown   += est_size;
1444     amount_to_grow -= est_size;
1445   }
1446 
1447   if (calls_made_hot > 0)  set_major_progress();
1448   return calls_made_hot;
1449 }
1450 
1451 
1452 //----------------------------Finish_Warm--------------------------------------
1453 void Compile::Finish_Warm() {
1454   if (!InlineWarmCalls)  return;
1455   if (failing())  return;
1456   if (warm_calls() == NULL)  return;
1457 
1458   // Clean up loose ends, if we are out of space for inlining.
1459   WarmCallInfo* call;
1460   while ((call = pop_warm_call()) != NULL) {
1461     call->make_cold();
1462   }
1463 }
1464 
1465 
1466 //------------------------------Optimize---------------------------------------
1467 // Given a graph, optimize it.
1468 void Compile::Optimize() {
1469   TracePhase t1("optimizer", &_t_optimizer, true);
1470 
1471 #ifndef PRODUCT
1472   if (env()->break_at_compile()) {
1473     BREAKPOINT;
1474   }
1475 
1476 #endif
1477 
1478   ResourceMark rm;
1479   int          loop_opts_cnt;
1480 
1481   NOT_PRODUCT( verify_graph_edges(); )
1482 
1483   print_method("After Parsing");
1484 
1485  {
1486   // Iterative Global Value Numbering, including ideal transforms
1487   // Initialize IterGVN with types and values from parse-time GVN
1488   PhaseIterGVN igvn(initial_gvn());
1489   {
1490     NOT_PRODUCT( TracePhase t2("iterGVN", &_t_iterGVN, TimeCompiler); )
1491     igvn.optimize();
1492   }
1493 
1494   print_method("Iter GVN 1", 2);
1495 
1496   if (failing())  return;
1497 
1498   // get rid of the connection graph since it's information is not
1499   // updated by optimizations
1500   _congraph = NULL;
1501 
1502 
1503   // Loop transforms on the ideal graph.  Range Check Elimination,
1504   // peeling, unrolling, etc.
1505 
1506   // Set loop opts counter
1507   loop_opts_cnt = num_loop_opts();
1508   if((loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
1509     {
1510       TracePhase t2("idealLoop", &_t_idealLoop, true);
1511       PhaseIdealLoop ideal_loop( igvn, NULL, true );
1512       loop_opts_cnt--;
1513       if (major_progress()) print_method("PhaseIdealLoop 1", 2);
1514       if (failing())  return;
1515     }
1516     // Loop opts pass if partial peeling occurred in previous pass
1517     if(PartialPeelLoop && major_progress() && (loop_opts_cnt > 0)) {
1518       TracePhase t3("idealLoop", &_t_idealLoop, true);
1519       PhaseIdealLoop ideal_loop( igvn, NULL, false );
1520       loop_opts_cnt--;
1521       if (major_progress()) print_method("PhaseIdealLoop 2", 2);
1522       if (failing())  return;
1523     }
1524     // Loop opts pass for loop-unrolling before CCP
1525     if(major_progress() && (loop_opts_cnt > 0)) {
1526       TracePhase t4("idealLoop", &_t_idealLoop, true);
1527       PhaseIdealLoop ideal_loop( igvn, NULL, false );
1528       loop_opts_cnt--;
1529       if (major_progress()) print_method("PhaseIdealLoop 3", 2);
1530     }
1531   }
1532   if (failing())  return;
1533 
1534   // Conditional Constant Propagation;
1535   PhaseCCP ccp( &igvn );
1536   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
1537   {
1538     TracePhase t2("ccp", &_t_ccp, true);
1539     ccp.do_transform();
1540   }
1541   print_method("PhaseCPP 1", 2);
1542 
1543   assert( true, "Break here to ccp.dump_old2new_map()");
1544 
1545   // Iterative Global Value Numbering, including ideal transforms
1546   {
1547     NOT_PRODUCT( TracePhase t2("iterGVN2", &_t_iterGVN2, TimeCompiler); )
1548     igvn = ccp;
1549     igvn.optimize();
1550   }
1551 
1552   print_method("Iter GVN 2", 2);
1553 
1554   if (failing())  return;
1555 
1556   // Loop transforms on the ideal graph.  Range Check Elimination,
1557   // peeling, unrolling, etc.
1558   if(loop_opts_cnt > 0) {
1559     debug_only( int cnt = 0; );
1560     while(major_progress() && (loop_opts_cnt > 0)) {
1561       TracePhase t2("idealLoop", &_t_idealLoop, true);
1562       assert( cnt++ < 40, "infinite cycle in loop optimization" );
1563       PhaseIdealLoop ideal_loop( igvn, NULL, true );
1564       loop_opts_cnt--;
1565       if (major_progress()) print_method("PhaseIdealLoop iterations", 2);
1566       if (failing())  return;
1567     }
1568   }
1569   {
1570     NOT_PRODUCT( TracePhase t2("macroExpand", &_t_macroExpand, TimeCompiler); )
1571     PhaseMacroExpand  mex(igvn);
1572     if (mex.expand_macro_nodes()) {
1573       assert(failing(), "must bail out w/ explicit message");
1574       return;
1575     }
1576   }
1577 
1578  } // (End scope of igvn; run destructor if necessary for asserts.)
1579 
1580   // A method with only infinite loops has no edges entering loops from root
1581   {
1582     NOT_PRODUCT( TracePhase t2("graphReshape", &_t_graphReshaping, TimeCompiler); )
1583     if (final_graph_reshaping()) {
1584       assert(failing(), "must bail out w/ explicit message");
1585       return;
1586     }
1587   }
1588 
1589   print_method("Optimize finished", 2);
1590 }
1591 
1592 
1593 //------------------------------Code_Gen---------------------------------------
1594 // Given a graph, generate code for it
1595 void Compile::Code_Gen() {
1596   if (failing())  return;
1597 
1598   // Perform instruction selection.  You might think we could reclaim Matcher
1599   // memory PDQ, but actually the Matcher is used in generating spill code.
1600   // Internals of the Matcher (including some VectorSets) must remain live
1601   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
1602   // set a bit in reclaimed memory.
1603 
1604   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
1605   // nodes.  Mapping is only valid at the root of each matched subtree.
1606   NOT_PRODUCT( verify_graph_edges(); )
1607 
1608   Node_List proj_list;
1609   Matcher m(proj_list);
1610   _matcher = &m;
1611   {
1612     TracePhase t2("matcher", &_t_matcher, true);
1613     m.match();
1614   }
1615   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
1616   // nodes.  Mapping is only valid at the root of each matched subtree.
1617   NOT_PRODUCT( verify_graph_edges(); )
1618 
1619   // If you have too many nodes, or if matching has failed, bail out
1620   check_node_count(0, "out of nodes matching instructions");
1621   if (failing())  return;
1622 
1623   // Build a proper-looking CFG
1624   PhaseCFG cfg(node_arena(), root(), m);
1625   _cfg = &cfg;
1626   {
1627     NOT_PRODUCT( TracePhase t2("scheduler", &_t_scheduler, TimeCompiler); )
1628     cfg.Dominators();
1629     if (failing())  return;
1630 
1631     NOT_PRODUCT( verify_graph_edges(); )
1632 
1633     cfg.Estimate_Block_Frequency();
1634     cfg.GlobalCodeMotion(m,unique(),proj_list);
1635 
1636     print_method("Global code motion", 2);
1637 
1638     if (failing())  return;
1639     NOT_PRODUCT( verify_graph_edges(); )
1640 
1641     debug_only( cfg.verify(); )
1642   }
1643   NOT_PRODUCT( verify_graph_edges(); )
1644 
1645   PhaseChaitin regalloc(unique(),cfg,m);
1646   _regalloc = &regalloc;
1647   {
1648     TracePhase t2("regalloc", &_t_registerAllocation, true);
1649     // Perform any platform dependent preallocation actions.  This is used,
1650     // for example, to avoid taking an implicit null pointer exception
1651     // using the frame pointer on win95.
1652     _regalloc->pd_preallocate_hook();
1653 
1654     // Perform register allocation.  After Chaitin, use-def chains are
1655     // no longer accurate (at spill code) and so must be ignored.
1656     // Node->LRG->reg mappings are still accurate.
1657     _regalloc->Register_Allocate();
1658 
1659     // Bail out if the allocator builds too many nodes
1660     if (failing())  return;
1661   }
1662 
1663   // Prior to register allocation we kept empty basic blocks in case the
1664   // the allocator needed a place to spill.  After register allocation we
1665   // are not adding any new instructions.  If any basic block is empty, we
1666   // can now safely remove it.
1667   {
1668     NOT_PRODUCT( TracePhase t2("removeEmpty", &_t_removeEmptyBlocks, TimeCompiler); )
1669     cfg.RemoveEmpty();
1670   }
1671 
1672   // Perform any platform dependent postallocation verifications.
1673   debug_only( _regalloc->pd_postallocate_verify_hook(); )
1674 
1675   // Apply peephole optimizations
1676   if( OptoPeephole ) {
1677     NOT_PRODUCT( TracePhase t2("peephole", &_t_peephole, TimeCompiler); )
1678     PhasePeephole peep( _regalloc, cfg);
1679     peep.do_transform();
1680   }
1681 
1682   // Convert Nodes to instruction bits in a buffer
1683   {
1684     // %%%% workspace merge brought two timers together for one job
1685     TracePhase t2a("output", &_t_output, true);
1686     NOT_PRODUCT( TraceTime t2b(NULL, &_t_codeGeneration, TimeCompiler, false); )
1687     Output();
1688   }
1689 
1690   print_method("Final Code");
1691 
1692   // He's dead, Jim.
1693   _cfg     = (PhaseCFG*)0xdeadbeef;
1694   _regalloc = (PhaseChaitin*)0xdeadbeef;
1695 }
1696 
1697 
1698 //------------------------------dump_asm---------------------------------------
1699 // Dump formatted assembly
1700 #ifndef PRODUCT
1701 void Compile::dump_asm(int *pcs, uint pc_limit) {
1702   bool cut_short = false;
1703   tty->print_cr("#");
1704   tty->print("#  ");  _tf->dump();  tty->cr();
1705   tty->print_cr("#");
1706 
1707   // For all blocks
1708   int pc = 0x0;                 // Program counter
1709   char starts_bundle = ' ';
1710   _regalloc->dump_frame();
1711 
1712   Node *n = NULL;
1713   for( uint i=0; i<_cfg->_num_blocks; i++ ) {
1714     if (VMThread::should_terminate()) { cut_short = true; break; }
1715     Block *b = _cfg->_blocks[i];
1716     if (b->is_connector() && !Verbose) continue;
1717     n = b->_nodes[0];
1718     if (pcs && n->_idx < pc_limit)
1719       tty->print("%3.3x   ", pcs[n->_idx]);
1720     else
1721       tty->print("      ");
1722     b->dump_head( &_cfg->_bbs );
1723     if (b->is_connector()) {
1724       tty->print_cr("        # Empty connector block");
1725     } else if (b->num_preds() == 2 && b->pred(1)->is_CatchProj() && b->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
1726       tty->print_cr("        # Block is sole successor of call");
1727     }
1728 
1729     // For all instructions
1730     Node *delay = NULL;
1731     for( uint j = 0; j<b->_nodes.size(); j++ ) {
1732       if (VMThread::should_terminate()) { cut_short = true; break; }
1733       n = b->_nodes[j];
1734       if (valid_bundle_info(n)) {
1735         Bundle *bundle = node_bundling(n);
1736         if (bundle->used_in_unconditional_delay()) {
1737           delay = n;
1738           continue;
1739         }
1740         if (bundle->starts_bundle())
1741           starts_bundle = '+';
1742       }
1743 
1744       if (WizardMode) n->dump();
1745 
1746       if( !n->is_Region() &&    // Dont print in the Assembly
1747           !n->is_Phi() &&       // a few noisely useless nodes
1748           !n->is_Proj() &&
1749           !n->is_MachTemp() &&
1750           !n->is_Catch() &&     // Would be nice to print exception table targets
1751           !n->is_MergeMem() &&  // Not very interesting
1752           !n->is_top() &&       // Debug info table constants
1753           !(n->is_Con() && !n->is_Mach())// Debug info table constants
1754           ) {
1755         if (pcs && n->_idx < pc_limit)
1756           tty->print("%3.3x", pcs[n->_idx]);
1757         else
1758           tty->print("   ");
1759         tty->print(" %c ", starts_bundle);
1760         starts_bundle = ' ';
1761         tty->print("\t");
1762         n->format(_regalloc, tty);
1763         tty->cr();
1764       }
1765 
1766       // If we have an instruction with a delay slot, and have seen a delay,
1767       // then back up and print it
1768       if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
1769         assert(delay != NULL, "no unconditional delay instruction");
1770         if (WizardMode) delay->dump();
1771 
1772         if (node_bundling(delay)->starts_bundle())
1773           starts_bundle = '+';
1774         if (pcs && n->_idx < pc_limit)
1775           tty->print("%3.3x", pcs[n->_idx]);
1776         else
1777           tty->print("   ");
1778         tty->print(" %c ", starts_bundle);
1779         starts_bundle = ' ';
1780         tty->print("\t");
1781         delay->format(_regalloc, tty);
1782         tty->print_cr("");
1783         delay = NULL;
1784       }
1785 
1786       // Dump the exception table as well
1787       if( n->is_Catch() && (Verbose || WizardMode) ) {
1788         // Print the exception table for this offset
1789         _handler_table.print_subtable_for(pc);
1790       }
1791     }
1792 
1793     if (pcs && n->_idx < pc_limit)
1794       tty->print_cr("%3.3x", pcs[n->_idx]);
1795     else
1796       tty->print_cr("");
1797 
1798     assert(cut_short || delay == NULL, "no unconditional delay branch");
1799 
1800   } // End of per-block dump
1801   tty->print_cr("");
1802 
1803   if (cut_short)  tty->print_cr("*** disassembly is cut short ***");
1804 }
1805 #endif
1806 
1807 //------------------------------Final_Reshape_Counts---------------------------
1808 // This class defines counters to help identify when a method
1809 // may/must be executed using hardware with only 24-bit precision.
1810 struct Final_Reshape_Counts : public StackObj {
1811   int  _call_count;             // count non-inlined 'common' calls
1812   int  _float_count;            // count float ops requiring 24-bit precision
1813   int  _double_count;           // count double ops requiring more precision
1814   int  _java_call_count;        // count non-inlined 'java' calls
1815   VectorSet _visited;           // Visitation flags
1816   Node_List _tests;             // Set of IfNodes & PCTableNodes
1817 
1818   Final_Reshape_Counts() :
1819     _call_count(0), _float_count(0), _double_count(0), _java_call_count(0),
1820     _visited( Thread::current()->resource_area() ) { }
1821 
1822   void inc_call_count  () { _call_count  ++; }
1823   void inc_float_count () { _float_count ++; }
1824   void inc_double_count() { _double_count++; }
1825   void inc_java_call_count() { _java_call_count++; }
1826 
1827   int  get_call_count  () const { return _call_count  ; }
1828   int  get_float_count () const { return _float_count ; }
1829   int  get_double_count() const { return _double_count; }
1830   int  get_java_call_count() const { return _java_call_count; }
1831 };
1832 
1833 static bool oop_offset_is_sane(const TypeInstPtr* tp) {
1834   ciInstanceKlass *k = tp->klass()->as_instance_klass();
1835   // Make sure the offset goes inside the instance layout.
1836   return k->contains_field_offset(tp->offset());
1837   // Note that OffsetBot and OffsetTop are very negative.
1838 }
1839 
1840 //------------------------------final_graph_reshaping_impl----------------------
1841 // Implement items 1-5 from final_graph_reshaping below.
1842 static void final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &fpu ) {
1843 
1844   if ( n->outcnt() == 0 ) return; // dead node
1845   uint nop = n->Opcode();
1846 
1847   // Check for 2-input instruction with "last use" on right input.
1848   // Swap to left input.  Implements item (2).
1849   if( n->req() == 3 &&          // two-input instruction
1850       n->in(1)->outcnt() > 1 && // left use is NOT a last use
1851       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
1852       n->in(2)->outcnt() == 1 &&// right use IS a last use
1853       !n->in(2)->is_Con() ) {   // right use is not a constant
1854     // Check for commutative opcode
1855     switch( nop ) {
1856     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddL:
1857     case Op_MaxI:  case Op_MinI:
1858     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulL:
1859     case Op_AndL:  case Op_XorL:  case Op_OrL:
1860     case Op_AndI:  case Op_XorI:  case Op_OrI: {
1861       // Move "last use" input to left by swapping inputs
1862       n->swap_edges(1, 2);
1863       break;
1864     }
1865     default:
1866       break;
1867     }
1868   }
1869 
1870   // Count FPU ops and common calls, implements item (3)
1871   switch( nop ) {
1872   // Count all float operations that may use FPU
1873   case Op_AddF:
1874   case Op_SubF:
1875   case Op_MulF:
1876   case Op_DivF:
1877   case Op_NegF:
1878   case Op_ModF:
1879   case Op_ConvI2F:
1880   case Op_ConF:
1881   case Op_CmpF:
1882   case Op_CmpF3:
1883   // case Op_ConvL2F: // longs are split into 32-bit halves
1884     fpu.inc_float_count();
1885     break;
1886 
1887   case Op_ConvF2D:
1888   case Op_ConvD2F:
1889     fpu.inc_float_count();
1890     fpu.inc_double_count();
1891     break;
1892 
1893   // Count all double operations that may use FPU
1894   case Op_AddD:
1895   case Op_SubD:
1896   case Op_MulD:
1897   case Op_DivD:
1898   case Op_NegD:
1899   case Op_ModD:
1900   case Op_ConvI2D:
1901   case Op_ConvD2I:
1902   // case Op_ConvL2D: // handled by leaf call
1903   // case Op_ConvD2L: // handled by leaf call
1904   case Op_ConD:
1905   case Op_CmpD:
1906   case Op_CmpD3:
1907     fpu.inc_double_count();
1908     break;
1909   case Op_Opaque1:              // Remove Opaque Nodes before matching
1910   case Op_Opaque2:              // Remove Opaque Nodes before matching
1911     n->subsume_by(n->in(1));
1912     break;
1913   case Op_CallStaticJava:
1914   case Op_CallJava:
1915   case Op_CallDynamicJava:
1916     fpu.inc_java_call_count(); // Count java call site;
1917   case Op_CallRuntime:
1918   case Op_CallLeaf:
1919   case Op_CallLeafNoFP: {
1920     assert( n->is_Call(), "" );
1921     CallNode *call = n->as_Call();
1922     // Count call sites where the FP mode bit would have to be flipped.
1923     // Do not count uncommon runtime calls:
1924     // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
1925     // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
1926     if( !call->is_CallStaticJava() || !call->as_CallStaticJava()->_name ) {
1927       fpu.inc_call_count();   // Count the call site
1928     } else {                  // See if uncommon argument is shared
1929       Node *n = call->in(TypeFunc::Parms);
1930       int nop = n->Opcode();
1931       // Clone shared simple arguments to uncommon calls, item (1).
1932       if( n->outcnt() > 1 &&
1933           !n->is_Proj() &&
1934           nop != Op_CreateEx &&
1935           nop != Op_CheckCastPP &&
1936           !n->is_Mem() ) {
1937         Node *x = n->clone();
1938         call->set_req( TypeFunc::Parms, x );
1939       }
1940     }
1941     break;
1942   }
1943 
1944   case Op_StoreD:
1945   case Op_LoadD:
1946   case Op_LoadD_unaligned:
1947     fpu.inc_double_count();
1948     goto handle_mem;
1949   case Op_StoreF:
1950   case Op_LoadF:
1951     fpu.inc_float_count();
1952     goto handle_mem;
1953 
1954   case Op_StoreB:
1955   case Op_StoreC:
1956   case Op_StoreCM:
1957   case Op_StorePConditional:
1958   case Op_StoreI:
1959   case Op_StoreL:
1960   case Op_StoreLConditional:
1961   case Op_CompareAndSwapI:
1962   case Op_CompareAndSwapL:
1963   case Op_CompareAndSwapP:
1964   case Op_CompareAndSwapN:
1965   case Op_StoreP:
1966   case Op_StoreN:
1967   case Op_LoadB:
1968   case Op_LoadC:
1969   case Op_LoadI:
1970   case Op_LoadKlass:
1971   case Op_LoadNKlass:
1972   case Op_LoadL:
1973   case Op_LoadL_unaligned:
1974   case Op_LoadPLocked:
1975   case Op_LoadLLocked:
1976   case Op_LoadP:
1977   case Op_LoadN:
1978   case Op_LoadRange:
1979   case Op_LoadS: {
1980   handle_mem:
1981 #ifdef ASSERT
1982     if( VerifyOptoOopOffsets ) {
1983       assert( n->is_Mem(), "" );
1984       MemNode *mem  = (MemNode*)n;
1985       // Check to see if address types have grounded out somehow.
1986       const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
1987       assert( !tp || oop_offset_is_sane(tp), "" );
1988     }
1989 #endif
1990     break;
1991   }
1992 
1993   case Op_AddP: {               // Assert sane base pointers
1994     Node *addp = n->in(AddPNode::Address);
1995     assert( !addp->is_AddP() ||
1996             addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
1997             addp->in(AddPNode::Base) == n->in(AddPNode::Base),
1998             "Base pointers must match" );
1999 #ifdef _LP64
2000     if (UseCompressedOops &&
2001         addp->Opcode() == Op_ConP &&
2002         addp == n->in(AddPNode::Base) &&
2003         n->in(AddPNode::Offset)->is_Con()) {
2004       // Use addressing with narrow klass to load with offset on x86.
2005       // On sparc loading 32-bits constant and decoding it have less
2006       // instructions (4) then load 64-bits constant (7).
2007       // Do this transformation here since IGVN will convert ConN back to ConP.
2008       const Type* t = addp->bottom_type();
2009       if (t->isa_oopptr()) {
2010         Node* nn = NULL;
2011 
2012         // Look for existing ConN node of the same exact type.
2013         Compile* C = Compile::current();
2014         Node* r  = C->root();
2015         uint cnt = r->outcnt();
2016         for (uint i = 0; i < cnt; i++) {
2017           Node* m = r->raw_out(i);
2018           if (m!= NULL && m->Opcode() == Op_ConN &&
2019               m->bottom_type()->is_narrowoop()->make_oopptr() == t) {
2020             nn = m;
2021             break;
2022           }
2023         }
2024         if (nn != NULL) {
2025           // Decode a narrow oop to match address
2026           // [R12 + narrow_oop_reg<<3 + offset]
2027           nn = new (C,  2) DecodeNNode(nn, t);
2028           n->set_req(AddPNode::Base, nn);
2029           n->set_req(AddPNode::Address, nn);
2030           if (addp->outcnt() == 0) {
2031             addp->disconnect_inputs(NULL);
2032           }
2033         }
2034       }
2035     }
2036 #endif
2037     break;
2038   }
2039 
2040 #ifdef _LP64
2041   case Op_CmpP:
2042     // Do this transformation here to preserve CmpPNode::sub() and
2043     // other TypePtr related Ideal optimizations (for example, ptr nullness).
2044     if( n->in(1)->is_DecodeN() ) {
2045       Compile* C = Compile::current();
2046       Node* in2 = NULL;
2047       if( n->in(2)->is_DecodeN() ) {
2048         in2 = n->in(2)->in(1);
2049       } else if ( n->in(2)->Opcode() == Op_ConP ) {
2050         const Type* t = n->in(2)->bottom_type();
2051         if (t == TypePtr::NULL_PTR) {
2052           Node *in1 = n->in(1);
2053           if (Matcher::clone_shift_expressions) {
2054             // x86, ARM and friends can handle 2 adds in addressing mode.
2055             // Decode a narrow oop and do implicit NULL check in address
2056             // [R12 + narrow_oop_reg<<3 + offset]
2057             in2 = ConNode::make(C, TypeNarrowOop::NULL_PTR);
2058           } else {
2059             // Don't replace CmpP(o ,null) if 'o' is used in AddP
2060             // to generate implicit NULL check on Sparc where
2061             // narrow oops can't be used in address.
2062             uint i = 0;
2063             for (; i < in1->outcnt(); i++) {
2064               if (in1->raw_out(i)->is_AddP())
2065                 break;
2066             }
2067             if (i >= in1->outcnt()) {
2068               in2 = ConNode::make(C, TypeNarrowOop::NULL_PTR);
2069             }
2070           }
2071         } else if (t->isa_oopptr()) {
2072           in2 = ConNode::make(C, t->is_oopptr()->make_narrowoop());
2073         }
2074       }
2075       if( in2 != NULL ) {
2076         Node* cmpN = new (C, 3) CmpNNode(n->in(1)->in(1), in2);
2077         n->subsume_by( cmpN );
2078       }
2079     }
2080 #endif
2081 
2082   case Op_ModI:
2083     if (UseDivMod) {
2084       // Check if a%b and a/b both exist
2085       Node* d = n->find_similar(Op_DivI);
2086       if (d) {
2087         // Replace them with a fused divmod if supported
2088         Compile* C = Compile::current();
2089         if (Matcher::has_match_rule(Op_DivModI)) {
2090           DivModINode* divmod = DivModINode::make(C, n);
2091           d->subsume_by(divmod->div_proj());
2092           n->subsume_by(divmod->mod_proj());
2093         } else {
2094           // replace a%b with a-((a/b)*b)
2095           Node* mult = new (C, 3) MulINode(d, d->in(2));
2096           Node* sub  = new (C, 3) SubINode(d->in(1), mult);
2097           n->subsume_by( sub );
2098         }
2099       }
2100     }
2101     break;
2102 
2103   case Op_ModL:
2104     if (UseDivMod) {
2105       // Check if a%b and a/b both exist
2106       Node* d = n->find_similar(Op_DivL);
2107       if (d) {
2108         // Replace them with a fused divmod if supported
2109         Compile* C = Compile::current();
2110         if (Matcher::has_match_rule(Op_DivModL)) {
2111           DivModLNode* divmod = DivModLNode::make(C, n);
2112           d->subsume_by(divmod->div_proj());
2113           n->subsume_by(divmod->mod_proj());
2114         } else {
2115           // replace a%b with a-((a/b)*b)
2116           Node* mult = new (C, 3) MulLNode(d, d->in(2));
2117           Node* sub  = new (C, 3) SubLNode(d->in(1), mult);
2118           n->subsume_by( sub );
2119         }
2120       }
2121     }
2122     break;
2123 
2124   case Op_Load16B:
2125   case Op_Load8B:
2126   case Op_Load4B:
2127   case Op_Load8S:
2128   case Op_Load4S:
2129   case Op_Load2S:
2130   case Op_Load8C:
2131   case Op_Load4C:
2132   case Op_Load2C:
2133   case Op_Load4I:
2134   case Op_Load2I:
2135   case Op_Load2L:
2136   case Op_Load4F:
2137   case Op_Load2F:
2138   case Op_Load2D:
2139   case Op_Store16B:
2140   case Op_Store8B:
2141   case Op_Store4B:
2142   case Op_Store8C:
2143   case Op_Store4C:
2144   case Op_Store2C:
2145   case Op_Store4I:
2146   case Op_Store2I:
2147   case Op_Store2L:
2148   case Op_Store4F:
2149   case Op_Store2F:
2150   case Op_Store2D:
2151     break;
2152 
2153   case Op_PackB:
2154   case Op_PackS:
2155   case Op_PackC:
2156   case Op_PackI:
2157   case Op_PackF:
2158   case Op_PackL:
2159   case Op_PackD:
2160     if (n->req()-1 > 2) {
2161       // Replace many operand PackNodes with a binary tree for matching
2162       PackNode* p = (PackNode*) n;
2163       Node* btp = p->binaryTreePack(Compile::current(), 1, n->req());
2164       n->subsume_by(btp);
2165     }
2166     break;
2167   default:
2168     assert( !n->is_Call(), "" );
2169     assert( !n->is_Mem(), "" );
2170     break;
2171   }
2172 
2173   // Collect CFG split points
2174   if (n->is_MultiBranch())
2175     fpu._tests.push(n);
2176 }
2177 
2178 //------------------------------final_graph_reshaping_walk---------------------
2179 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
2180 // requires that the walk visits a node's inputs before visiting the node.
2181 static void final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Reshape_Counts &fpu ) {
2182   fpu._visited.set(root->_idx); // first, mark node as visited
2183   uint cnt = root->req();
2184   Node *n = root;
2185   uint  i = 0;
2186   while (true) {
2187     if (i < cnt) {
2188       // Place all non-visited non-null inputs onto stack
2189       Node* m = n->in(i);
2190       ++i;
2191       if (m != NULL && !fpu._visited.test_set(m->_idx)) {
2192         cnt = m->req();
2193         nstack.push(n, i); // put on stack parent and next input's index
2194         n = m;
2195         i = 0;
2196       }
2197     } else {
2198       // Now do post-visit work
2199       final_graph_reshaping_impl( n, fpu );
2200       if (nstack.is_empty())
2201         break;             // finished
2202       n = nstack.node();   // Get node from stack
2203       cnt = n->req();
2204       i = nstack.index();
2205       nstack.pop();        // Shift to the next node on stack
2206     }
2207   }
2208 }
2209 
2210 //------------------------------final_graph_reshaping--------------------------
2211 // Final Graph Reshaping.
2212 //
2213 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
2214 //     and not commoned up and forced early.  Must come after regular
2215 //     optimizations to avoid GVN undoing the cloning.  Clone constant
2216 //     inputs to Loop Phis; these will be split by the allocator anyways.
2217 //     Remove Opaque nodes.
2218 // (2) Move last-uses by commutative operations to the left input to encourage
2219 //     Intel update-in-place two-address operations and better register usage
2220 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
2221 //     calls canonicalizing them back.
2222 // (3) Count the number of double-precision FP ops, single-precision FP ops
2223 //     and call sites.  On Intel, we can get correct rounding either by
2224 //     forcing singles to memory (requires extra stores and loads after each
2225 //     FP bytecode) or we can set a rounding mode bit (requires setting and
2226 //     clearing the mode bit around call sites).  The mode bit is only used
2227 //     if the relative frequency of single FP ops to calls is low enough.
2228 //     This is a key transform for SPEC mpeg_audio.
2229 // (4) Detect infinite loops; blobs of code reachable from above but not
2230 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
2231 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
2232 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
2233 //     Detection is by looking for IfNodes where only 1 projection is
2234 //     reachable from below or CatchNodes missing some targets.
2235 // (5) Assert for insane oop offsets in debug mode.
2236 
2237 bool Compile::final_graph_reshaping() {
2238   // an infinite loop may have been eliminated by the optimizer,
2239   // in which case the graph will be empty.
2240   if (root()->req() == 1) {
2241     record_method_not_compilable("trivial infinite loop");
2242     return true;
2243   }
2244 
2245   Final_Reshape_Counts fpu;
2246 
2247   // Visit everybody reachable!
2248   // Allocate stack of size C->unique()/2 to avoid frequent realloc
2249   Node_Stack nstack(unique() >> 1);
2250   final_graph_reshaping_walk(nstack, root(), fpu);
2251 
2252   // Check for unreachable (from below) code (i.e., infinite loops).
2253   for( uint i = 0; i < fpu._tests.size(); i++ ) {
2254     MultiBranchNode *n = fpu._tests[i]->as_MultiBranch();
2255     // Get number of CFG targets.
2256     // Note that PCTables include exception targets after calls.
2257     uint required_outcnt = n->required_outcnt();
2258     if (n->outcnt() != required_outcnt) {
2259       // Check for a few special cases.  Rethrow Nodes never take the
2260       // 'fall-thru' path, so expected kids is 1 less.
2261       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
2262         if (n->in(0)->in(0)->is_Call()) {
2263           CallNode *call = n->in(0)->in(0)->as_Call();
2264           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
2265             required_outcnt--;      // Rethrow always has 1 less kid
2266           } else if (call->req() > TypeFunc::Parms &&
2267                      call->is_CallDynamicJava()) {
2268             // Check for null receiver. In such case, the optimizer has
2269             // detected that the virtual call will always result in a null
2270             // pointer exception. The fall-through projection of this CatchNode
2271             // will not be populated.
2272             Node *arg0 = call->in(TypeFunc::Parms);
2273             if (arg0->is_Type() &&
2274                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
2275               required_outcnt--;
2276             }
2277           } else if (call->entry_point() == OptoRuntime::new_array_Java() &&
2278                      call->req() > TypeFunc::Parms+1 &&
2279                      call->is_CallStaticJava()) {
2280             // Check for negative array length. In such case, the optimizer has
2281             // detected that the allocation attempt will always result in an
2282             // exception. There is no fall-through projection of this CatchNode .
2283             Node *arg1 = call->in(TypeFunc::Parms+1);
2284             if (arg1->is_Type() &&
2285                 arg1->as_Type()->type()->join(TypeInt::POS)->empty()) {
2286               required_outcnt--;
2287             }
2288           }
2289         }
2290       }
2291       // Recheck with a better notion of 'required_outcnt'
2292       if (n->outcnt() != required_outcnt) {
2293         record_method_not_compilable("malformed control flow");
2294         return true;            // Not all targets reachable!
2295       }
2296     }
2297     // Check that I actually visited all kids.  Unreached kids
2298     // must be infinite loops.
2299     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
2300       if (!fpu._visited.test(n->fast_out(j)->_idx)) {
2301         record_method_not_compilable("infinite loop");
2302         return true;            // Found unvisited kid; must be unreach
2303       }
2304   }
2305 
2306   // If original bytecodes contained a mixture of floats and doubles
2307   // check if the optimizer has made it homogenous, item (3).
2308   if( Use24BitFPMode && Use24BitFP &&
2309       fpu.get_float_count() > 32 &&
2310       fpu.get_double_count() == 0 &&
2311       (10 * fpu.get_call_count() < fpu.get_float_count()) ) {
2312     set_24_bit_selection_and_mode( false,  true );
2313   }
2314 
2315   set_has_java_calls(fpu.get_java_call_count() > 0);
2316 
2317   // No infinite loops, no reason to bail out.
2318   return false;
2319 }
2320 
2321 //-----------------------------too_many_traps----------------------------------
2322 // Report if there are too many traps at the current method and bci.
2323 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
2324 bool Compile::too_many_traps(ciMethod* method,
2325                              int bci,
2326                              Deoptimization::DeoptReason reason) {
2327   ciMethodData* md = method->method_data();
2328   if (md->is_empty()) {
2329     // Assume the trap has not occurred, or that it occurred only
2330     // because of a transient condition during start-up in the interpreter.
2331     return false;
2332   }
2333   if (md->has_trap_at(bci, reason) != 0) {
2334     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
2335     // Also, if there are multiple reasons, or if there is no per-BCI record,
2336     // assume the worst.
2337     if (log())
2338       log()->elem("observe trap='%s' count='%d'",
2339                   Deoptimization::trap_reason_name(reason),
2340                   md->trap_count(reason));
2341     return true;
2342   } else {
2343     // Ignore method/bci and see if there have been too many globally.
2344     return too_many_traps(reason, md);
2345   }
2346 }
2347 
2348 // Less-accurate variant which does not require a method and bci.
2349 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
2350                              ciMethodData* logmd) {
2351  if (trap_count(reason) >= (uint)PerMethodTrapLimit) {
2352     // Too many traps globally.
2353     // Note that we use cumulative trap_count, not just md->trap_count.
2354     if (log()) {
2355       int mcount = (logmd == NULL)? -1: (int)logmd->trap_count(reason);
2356       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
2357                   Deoptimization::trap_reason_name(reason),
2358                   mcount, trap_count(reason));
2359     }
2360     return true;
2361   } else {
2362     // The coast is clear.
2363     return false;
2364   }
2365 }
2366 
2367 //--------------------------too_many_recompiles--------------------------------
2368 // Report if there are too many recompiles at the current method and bci.
2369 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
2370 // Is not eager to return true, since this will cause the compiler to use
2371 // Action_none for a trap point, to avoid too many recompilations.
2372 bool Compile::too_many_recompiles(ciMethod* method,
2373                                   int bci,
2374                                   Deoptimization::DeoptReason reason) {
2375   ciMethodData* md = method->method_data();
2376   if (md->is_empty()) {
2377     // Assume the trap has not occurred, or that it occurred only
2378     // because of a transient condition during start-up in the interpreter.
2379     return false;
2380   }
2381   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
2382   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
2383   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
2384   Deoptimization::DeoptReason per_bc_reason
2385     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
2386   if ((per_bc_reason == Deoptimization::Reason_none
2387        || md->has_trap_at(bci, reason) != 0)
2388       // The trap frequency measure we care about is the recompile count:
2389       && md->trap_recompiled_at(bci)
2390       && md->overflow_recompile_count() >= bc_cutoff) {
2391     // Do not emit a trap here if it has already caused recompilations.
2392     // Also, if there are multiple reasons, or if there is no per-BCI record,
2393     // assume the worst.
2394     if (log())
2395       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
2396                   Deoptimization::trap_reason_name(reason),
2397                   md->trap_count(reason),
2398                   md->overflow_recompile_count());
2399     return true;
2400   } else if (trap_count(reason) != 0
2401              && decompile_count() >= m_cutoff) {
2402     // Too many recompiles globally, and we have seen this sort of trap.
2403     // Use cumulative decompile_count, not just md->decompile_count.
2404     if (log())
2405       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
2406                   Deoptimization::trap_reason_name(reason),
2407                   md->trap_count(reason), trap_count(reason),
2408                   md->decompile_count(), decompile_count());
2409     return true;
2410   } else {
2411     // The coast is clear.
2412     return false;
2413   }
2414 }
2415 
2416 
2417 #ifndef PRODUCT
2418 //------------------------------verify_graph_edges---------------------------
2419 // Walk the Graph and verify that there is a one-to-one correspondence
2420 // between Use-Def edges and Def-Use edges in the graph.
2421 void Compile::verify_graph_edges(bool no_dead_code) {
2422   if (VerifyGraphEdges) {
2423     ResourceArea *area = Thread::current()->resource_area();
2424     Unique_Node_List visited(area);
2425     // Call recursive graph walk to check edges
2426     _root->verify_edges(visited);
2427     if (no_dead_code) {
2428       // Now make sure that no visited node is used by an unvisited node.
2429       bool dead_nodes = 0;
2430       Unique_Node_List checked(area);
2431       while (visited.size() > 0) {
2432         Node* n = visited.pop();
2433         checked.push(n);
2434         for (uint i = 0; i < n->outcnt(); i++) {
2435           Node* use = n->raw_out(i);
2436           if (checked.member(use))  continue;  // already checked
2437           if (visited.member(use))  continue;  // already in the graph
2438           if (use->is_Con())        continue;  // a dead ConNode is OK
2439           // At this point, we have found a dead node which is DU-reachable.
2440           if (dead_nodes++ == 0)
2441             tty->print_cr("*** Dead nodes reachable via DU edges:");
2442           use->dump(2);
2443           tty->print_cr("---");
2444           checked.push(use);  // No repeats; pretend it is now checked.
2445         }
2446       }
2447       assert(dead_nodes == 0, "using nodes must be reachable from root");
2448     }
2449   }
2450 }
2451 #endif
2452 
2453 // The Compile object keeps track of failure reasons separately from the ciEnv.
2454 // This is required because there is not quite a 1-1 relation between the
2455 // ciEnv and its compilation task and the Compile object.  Note that one
2456 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
2457 // to backtrack and retry without subsuming loads.  Other than this backtracking
2458 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
2459 // by the logic in C2Compiler.
2460 void Compile::record_failure(const char* reason) {
2461   if (log() != NULL) {
2462     log()->elem("failure reason='%s' phase='compile'", reason);
2463   }
2464   if (_failure_reason == NULL) {
2465     // Record the first failure reason.
2466     _failure_reason = reason;
2467   }
2468   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
2469     C->print_method(_failure_reason);
2470   }
2471   _root = NULL;  // flush the graph, too
2472 }
2473 
2474 Compile::TracePhase::TracePhase(const char* name, elapsedTimer* accumulator, bool dolog)
2475   : TraceTime(NULL, accumulator, false NOT_PRODUCT( || TimeCompiler ), false)
2476 {
2477   if (dolog) {
2478     C = Compile::current();
2479     _log = C->log();
2480   } else {
2481     C = NULL;
2482     _log = NULL;
2483   }
2484   if (_log != NULL) {
2485     _log->begin_head("phase name='%s' nodes='%d'", name, C->unique());
2486     _log->stamp();
2487     _log->end_head();
2488   }
2489 }
2490 
2491 Compile::TracePhase::~TracePhase() {
2492   if (_log != NULL) {
2493     _log->done("phase nodes='%d'", C->unique());
2494   }
2495 }