1 /*
   2  * Copyright 1997-2009 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       m->intrinsic_id() <= vmIntrinsics::LAST_COMPILER_INLINE) {
 106     CallGenerator* cg = make_vm_intrinsic(m, is_virtual);
 107     if (cg != NULL) {
 108       // Save it for next time:
 109       register_intrinsic(cg);
 110       return cg;
 111     } else {
 112       gather_intrinsic_statistics(m->intrinsic_id(), is_virtual, _intrinsic_disabled);
 113     }
 114   }
 115   return NULL;
 116 }
 117 
 118 // Compile:: register_library_intrinsics and make_vm_intrinsic are defined
 119 // in library_call.cpp.
 120 
 121 
 122 #ifndef PRODUCT
 123 // statistics gathering...
 124 
 125 juint  Compile::_intrinsic_hist_count[vmIntrinsics::ID_LIMIT] = {0};
 126 jubyte Compile::_intrinsic_hist_flags[vmIntrinsics::ID_LIMIT] = {0};
 127 
 128 bool Compile::gather_intrinsic_statistics(vmIntrinsics::ID id, bool is_virtual, int flags) {
 129   assert(id > vmIntrinsics::_none && id < vmIntrinsics::ID_LIMIT, "oob");
 130   int oflags = _intrinsic_hist_flags[id];
 131   assert(flags != 0, "what happened?");
 132   if (is_virtual) {
 133     flags |= _intrinsic_virtual;
 134   }
 135   bool changed = (flags != oflags);
 136   if ((flags & _intrinsic_worked) != 0) {
 137     juint count = (_intrinsic_hist_count[id] += 1);
 138     if (count == 1) {
 139       changed = true;           // first time
 140     }
 141     // increment the overall count also:
 142     _intrinsic_hist_count[vmIntrinsics::_none] += 1;
 143   }
 144   if (changed) {
 145     if (((oflags ^ flags) & _intrinsic_virtual) != 0) {
 146       // Something changed about the intrinsic's virtuality.
 147       if ((flags & _intrinsic_virtual) != 0) {
 148         // This is the first use of this intrinsic as a virtual call.
 149         if (oflags != 0) {
 150           // We already saw it as a non-virtual, so note both cases.
 151           flags |= _intrinsic_both;
 152         }
 153       } else if ((oflags & _intrinsic_both) == 0) {
 154         // This is the first use of this intrinsic as a non-virtual
 155         flags |= _intrinsic_both;
 156       }
 157     }
 158     _intrinsic_hist_flags[id] = (jubyte) (oflags | flags);
 159   }
 160   // update the overall flags also:
 161   _intrinsic_hist_flags[vmIntrinsics::_none] |= (jubyte) flags;
 162   return changed;
 163 }
 164 
 165 static char* format_flags(int flags, char* buf) {
 166   buf[0] = 0;
 167   if ((flags & Compile::_intrinsic_worked) != 0)    strcat(buf, ",worked");
 168   if ((flags & Compile::_intrinsic_failed) != 0)    strcat(buf, ",failed");
 169   if ((flags & Compile::_intrinsic_disabled) != 0)  strcat(buf, ",disabled");
 170   if ((flags & Compile::_intrinsic_virtual) != 0)   strcat(buf, ",virtual");
 171   if ((flags & Compile::_intrinsic_both) != 0)      strcat(buf, ",nonvirtual");
 172   if (buf[0] == 0)  strcat(buf, ",");
 173   assert(buf[0] == ',', "must be");
 174   return &buf[1];
 175 }
 176 
 177 void Compile::print_intrinsic_statistics() {
 178   char flagsbuf[100];
 179   ttyLocker ttyl;
 180   if (xtty != NULL)  xtty->head("statistics type='intrinsic'");
 181   tty->print_cr("Compiler intrinsic usage:");
 182   juint total = _intrinsic_hist_count[vmIntrinsics::_none];
 183   if (total == 0)  total = 1;  // avoid div0 in case of no successes
 184   #define PRINT_STAT_LINE(name, c, f) \
 185     tty->print_cr("  %4d (%4.1f%%) %s (%s)", (int)(c), ((c) * 100.0) / total, name, f);
 186   for (int index = 1 + (int)vmIntrinsics::_none; index < (int)vmIntrinsics::ID_LIMIT; index++) {
 187     vmIntrinsics::ID id = (vmIntrinsics::ID) index;
 188     int   flags = _intrinsic_hist_flags[id];
 189     juint count = _intrinsic_hist_count[id];
 190     if ((flags | count) != 0) {
 191       PRINT_STAT_LINE(vmIntrinsics::name_at(id), count, format_flags(flags, flagsbuf));
 192     }
 193   }
 194   PRINT_STAT_LINE("total", total, format_flags(_intrinsic_hist_flags[vmIntrinsics::_none], flagsbuf));
 195   if (xtty != NULL)  xtty->tail("statistics");
 196 }
 197 
 198 void Compile::print_statistics() {
 199   { ttyLocker ttyl;
 200     if (xtty != NULL)  xtty->head("statistics type='opto'");
 201     Parse::print_statistics();
 202     PhaseCCP::print_statistics();
 203     PhaseRegAlloc::print_statistics();
 204     Scheduling::print_statistics();
 205     PhasePeephole::print_statistics();
 206     PhaseIdealLoop::print_statistics();
 207     if (xtty != NULL)  xtty->tail("statistics");
 208   }
 209   if (_intrinsic_hist_flags[vmIntrinsics::_none] != 0) {
 210     // put this under its own <statistics> element.
 211     print_intrinsic_statistics();
 212   }
 213 }
 214 #endif //PRODUCT
 215 
 216 // Support for bundling info
 217 Bundle* Compile::node_bundling(const Node *n) {
 218   assert(valid_bundle_info(n), "oob");
 219   return &_node_bundling_base[n->_idx];
 220 }
 221 
 222 bool Compile::valid_bundle_info(const Node *n) {
 223   return (_node_bundling_limit > n->_idx);
 224 }
 225 
 226 
 227 // Identify all nodes that are reachable from below, useful.
 228 // Use breadth-first pass that records state in a Unique_Node_List,
 229 // recursive traversal is slower.
 230 void Compile::identify_useful_nodes(Unique_Node_List &useful) {
 231   int estimated_worklist_size = unique();
 232   useful.map( estimated_worklist_size, NULL );  // preallocate space
 233 
 234   // Initialize worklist
 235   if (root() != NULL)     { useful.push(root()); }
 236   // If 'top' is cached, declare it useful to preserve cached node
 237   if( cached_top_node() ) { useful.push(cached_top_node()); }
 238 
 239   // Push all useful nodes onto the list, breadthfirst
 240   for( uint next = 0; next < useful.size(); ++next ) {
 241     assert( next < unique(), "Unique useful nodes < total nodes");
 242     Node *n  = useful.at(next);
 243     uint max = n->len();
 244     for( uint i = 0; i < max; ++i ) {
 245       Node *m = n->in(i);
 246       if( m == NULL ) continue;
 247       useful.push(m);
 248     }
 249   }
 250 }
 251 
 252 // Disconnect all useless nodes by disconnecting those at the boundary.
 253 void Compile::remove_useless_nodes(Unique_Node_List &useful) {
 254   uint next = 0;
 255   while( next < useful.size() ) {
 256     Node *n = useful.at(next++);
 257     // Use raw traversal of out edges since this code removes out edges
 258     int max = n->outcnt();
 259     for (int j = 0; j < max; ++j ) {
 260       Node* child = n->raw_out(j);
 261       if( ! useful.member(child) ) {
 262         assert( !child->is_top() || child != top(),
 263                 "If top is cached in Compile object it is in useful list");
 264         // Only need to remove this out-edge to the useless node
 265         n->raw_del_out(j);
 266         --j;
 267         --max;
 268       }
 269     }
 270     if (n->outcnt() == 1 && n->has_special_unique_user()) {
 271       record_for_igvn( n->unique_out() );
 272     }
 273   }
 274   debug_only(verify_graph_edges(true/*check for no_dead_code*/);)
 275 }
 276 
 277 //------------------------------frame_size_in_words-----------------------------
 278 // frame_slots in units of words
 279 int Compile::frame_size_in_words() const {
 280   // shift is 0 in LP32 and 1 in LP64
 281   const int shift = (LogBytesPerWord - LogBytesPerInt);
 282   int words = _frame_slots >> shift;
 283   assert( words << shift == _frame_slots, "frame size must be properly aligned in LP64" );
 284   return words;
 285 }
 286 
 287 // ============================================================================
 288 //------------------------------CompileWrapper---------------------------------
 289 class CompileWrapper : public StackObj {
 290   Compile *const _compile;
 291  public:
 292   CompileWrapper(Compile* compile);
 293 
 294   ~CompileWrapper();
 295 };
 296 
 297 CompileWrapper::CompileWrapper(Compile* compile) : _compile(compile) {
 298   // the Compile* pointer is stored in the current ciEnv:
 299   ciEnv* env = compile->env();
 300   assert(env == ciEnv::current(), "must already be a ciEnv active");
 301   assert(env->compiler_data() == NULL, "compile already active?");
 302   env->set_compiler_data(compile);
 303   assert(compile == Compile::current(), "sanity");
 304 
 305   compile->set_type_dict(NULL);
 306   compile->set_type_hwm(NULL);
 307   compile->set_type_last_size(0);
 308   compile->set_last_tf(NULL, NULL);
 309   compile->set_indexSet_arena(NULL);
 310   compile->set_indexSet_free_block_list(NULL);
 311   compile->init_type_arena();
 312   Type::Initialize(compile);
 313   _compile->set_scratch_buffer_blob(NULL);
 314   _compile->begin_method();
 315 }
 316 CompileWrapper::~CompileWrapper() {
 317   _compile->end_method();
 318   if (_compile->scratch_buffer_blob() != NULL)
 319     BufferBlob::free(_compile->scratch_buffer_blob());
 320   _compile->env()->set_compiler_data(NULL);
 321 }
 322 
 323 
 324 //----------------------------print_compile_messages---------------------------
 325 void Compile::print_compile_messages() {
 326 #ifndef PRODUCT
 327   // Check if recompiling
 328   if (_subsume_loads == false && PrintOpto) {
 329     // Recompiling without allowing machine instructions to subsume loads
 330     tty->print_cr("*********************************************************");
 331     tty->print_cr("** Bailout: Recompile without subsuming loads          **");
 332     tty->print_cr("*********************************************************");
 333   }
 334   if (_do_escape_analysis != DoEscapeAnalysis && PrintOpto) {
 335     // Recompiling without escape analysis
 336     tty->print_cr("*********************************************************");
 337     tty->print_cr("** Bailout: Recompile without escape analysis          **");
 338     tty->print_cr("*********************************************************");
 339   }
 340   if (env()->break_at_compile()) {
 341     // Open the debugger when compiling this method.
 342     tty->print("### Breaking when compiling: ");
 343     method()->print_short_name();
 344     tty->cr();
 345     BREAKPOINT;
 346   }
 347 
 348   if( PrintOpto ) {
 349     if (is_osr_compilation()) {
 350       tty->print("[OSR]%3d", _compile_id);
 351     } else {
 352       tty->print("%3d", _compile_id);
 353     }
 354   }
 355 #endif
 356 }
 357 
 358 
 359 void Compile::init_scratch_buffer_blob() {
 360   if( scratch_buffer_blob() != NULL )  return;
 361 
 362   // Construct a temporary CodeBuffer to have it construct a BufferBlob
 363   // Cache this BufferBlob for this compile.
 364   ResourceMark rm;
 365   int size = (MAX_inst_size + MAX_stubs_size + MAX_const_size);
 366   BufferBlob* blob = BufferBlob::create("Compile::scratch_buffer", size);
 367   // Record the buffer blob for next time.
 368   set_scratch_buffer_blob(blob);
 369   // Have we run out of code space?
 370   if (scratch_buffer_blob() == NULL) {
 371     // Let CompilerBroker disable further compilations.
 372     record_failure("Not enough space for scratch buffer in CodeCache");
 373     return;
 374   }
 375 
 376   // Initialize the relocation buffers
 377   relocInfo* locs_buf = (relocInfo*) blob->instructions_end() - MAX_locs_size;
 378   set_scratch_locs_memory(locs_buf);
 379 }
 380 
 381 
 382 //-----------------------scratch_emit_size-------------------------------------
 383 // Helper function that computes size by emitting code
 384 uint Compile::scratch_emit_size(const Node* n) {
 385   // Emit into a trash buffer and count bytes emitted.
 386   // This is a pretty expensive way to compute a size,
 387   // but it works well enough if seldom used.
 388   // All common fixed-size instructions are given a size
 389   // method by the AD file.
 390   // Note that the scratch buffer blob and locs memory are
 391   // allocated at the beginning of the compile task, and
 392   // may be shared by several calls to scratch_emit_size.
 393   // The allocation of the scratch buffer blob is particularly
 394   // expensive, since it has to grab the code cache lock.
 395   BufferBlob* blob = this->scratch_buffer_blob();
 396   assert(blob != NULL, "Initialize BufferBlob at start");
 397   assert(blob->size() > MAX_inst_size, "sanity");
 398   relocInfo* locs_buf = scratch_locs_memory();
 399   address blob_begin = blob->instructions_begin();
 400   address blob_end   = (address)locs_buf;
 401   assert(blob->instructions_contains(blob_end), "sanity");
 402   CodeBuffer buf(blob_begin, blob_end - blob_begin);
 403   buf.initialize_consts_size(MAX_const_size);
 404   buf.initialize_stubs_size(MAX_stubs_size);
 405   assert(locs_buf != NULL, "sanity");
 406   int lsize = MAX_locs_size / 2;
 407   buf.insts()->initialize_shared_locs(&locs_buf[0],     lsize);
 408   buf.stubs()->initialize_shared_locs(&locs_buf[lsize], lsize);
 409   n->emit(buf, this->regalloc());
 410   return buf.code_size();
 411 }
 412 
 413 
 414 // ============================================================================
 415 //------------------------------Compile standard-------------------------------
 416 debug_only( int Compile::_debug_idx = 100000; )
 417 
 418 // Compile a method.  entry_bci is -1 for normal compilations and indicates
 419 // the continuation bci for on stack replacement.
 420 
 421 
 422 Compile::Compile( ciEnv* ci_env, C2Compiler* compiler, ciMethod* target, int osr_bci, bool subsume_loads, bool do_escape_analysis )
 423                 : Phase(Compiler),
 424                   _env(ci_env),
 425                   _log(ci_env->log()),
 426                   _compile_id(ci_env->compile_id()),
 427                   _save_argument_registers(false),
 428                   _stub_name(NULL),
 429                   _stub_function(NULL),
 430                   _stub_entry_point(NULL),
 431                   _method(target),
 432                   _entry_bci(osr_bci),
 433                   _initial_gvn(NULL),
 434                   _for_igvn(NULL),
 435                   _warm_calls(NULL),
 436                   _subsume_loads(subsume_loads),
 437                   _do_escape_analysis(do_escape_analysis),
 438                   _failure_reason(NULL),
 439                   _code_buffer("Compile::Fill_buffer"),
 440                   _orig_pc_slot(0),
 441                   _orig_pc_slot_offset_in_bytes(0),
 442                   _node_bundling_limit(0),
 443                   _node_bundling_base(NULL),
 444                   _java_calls(0),
 445                   _inner_loops(0),
 446 #ifndef PRODUCT
 447                   _trace_opto_output(TraceOptoOutput || method()->has_option("TraceOptoOutput")),
 448                   _printer(IdealGraphPrinter::printer()),
 449 #endif
 450                   _congraph(NULL) {
 451   C = this;
 452 
 453   CompileWrapper cw(this);
 454 #ifndef PRODUCT
 455   if (TimeCompiler2) {
 456     tty->print(" ");
 457     target->holder()->name()->print();
 458     tty->print(".");
 459     target->print_short_name();
 460     tty->print("  ");
 461   }
 462   TraceTime t1("Total compilation time", &_t_totalCompilation, TimeCompiler, TimeCompiler2);
 463   TraceTime t2(NULL, &_t_methodCompilation, TimeCompiler, false);
 464   bool print_opto_assembly = PrintOptoAssembly || _method->has_option("PrintOptoAssembly");
 465   if (!print_opto_assembly) {
 466     bool print_assembly = (PrintAssembly || _method->should_print_assembly());
 467     if (print_assembly && !Disassembler::can_decode()) {
 468       tty->print_cr("PrintAssembly request changed to PrintOptoAssembly");
 469       print_opto_assembly = true;
 470     }
 471   }
 472   set_print_assembly(print_opto_assembly);
 473   set_parsed_irreducible_loop(false);
 474 #endif
 475 
 476   if (ProfileTraps) {
 477     // Make sure the method being compiled gets its own MDO,
 478     // so we can at least track the decompile_count().
 479     method()->build_method_data();
 480   }
 481 
 482   Init(::AliasLevel);
 483 
 484 
 485   print_compile_messages();
 486 
 487   if (UseOldInlining || PrintCompilation NOT_PRODUCT( || PrintOpto) )
 488     _ilt = InlineTree::build_inline_tree_root();
 489   else
 490     _ilt = NULL;
 491 
 492   // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
 493   assert(num_alias_types() >= AliasIdxRaw, "");
 494 
 495 #define MINIMUM_NODE_HASH  1023
 496   // Node list that Iterative GVN will start with
 497   Unique_Node_List for_igvn(comp_arena());
 498   set_for_igvn(&for_igvn);
 499 
 500   // GVN that will be run immediately on new nodes
 501   uint estimated_size = method()->code_size()*4+64;
 502   estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
 503   PhaseGVN gvn(node_arena(), estimated_size);
 504   set_initial_gvn(&gvn);
 505 
 506   { // Scope for timing the parser
 507     TracePhase t3("parse", &_t_parser, true);
 508 
 509     // Put top into the hash table ASAP.
 510     initial_gvn()->transform_no_reclaim(top());
 511 
 512     // Set up tf(), start(), and find a CallGenerator.
 513     CallGenerator* cg;
 514     if (is_osr_compilation()) {
 515       const TypeTuple *domain = StartOSRNode::osr_domain();
 516       const TypeTuple *range = TypeTuple::make_range(method()->signature());
 517       init_tf(TypeFunc::make(domain, range));
 518       StartNode* s = new (this, 2) StartOSRNode(root(), domain);
 519       initial_gvn()->set_type_bottom(s);
 520       init_start(s);
 521       cg = CallGenerator::for_osr(method(), entry_bci());
 522     } else {
 523       // Normal case.
 524       init_tf(TypeFunc::make(method()));
 525       StartNode* s = new (this, 2) StartNode(root(), tf()->domain());
 526       initial_gvn()->set_type_bottom(s);
 527       init_start(s);
 528       float past_uses = method()->interpreter_invocation_count();
 529       float expected_uses = past_uses;
 530       cg = CallGenerator::for_inline(method(), expected_uses);
 531     }
 532     if (failing())  return;
 533     if (cg == NULL) {
 534       record_method_not_compilable_all_tiers("cannot parse method");
 535       return;
 536     }
 537     JVMState* jvms = build_start_state(start(), tf());
 538     if ((jvms = cg->generate(jvms)) == NULL) {
 539       record_method_not_compilable("method parse failed");
 540       return;
 541     }
 542     GraphKit kit(jvms);
 543 
 544     if (!kit.stopped()) {
 545       // Accept return values, and transfer control we know not where.
 546       // This is done by a special, unique ReturnNode bound to root.
 547       return_values(kit.jvms());
 548     }
 549 
 550     if (kit.has_exceptions()) {
 551       // Any exceptions that escape from this call must be rethrown
 552       // to whatever caller is dynamically above us on the stack.
 553       // This is done by a special, unique RethrowNode bound to root.
 554       rethrow_exceptions(kit.transfer_exceptions_into_jvms());
 555     }
 556 
 557     print_method("Before RemoveUseless", 3);
 558 
 559     // Remove clutter produced by parsing.
 560     if (!failing()) {
 561       ResourceMark rm;
 562       PhaseRemoveUseless pru(initial_gvn(), &for_igvn);
 563     }
 564   }
 565 
 566   // Note:  Large methods are capped off in do_one_bytecode().
 567   if (failing())  return;
 568 
 569   // After parsing, node notes are no longer automagic.
 570   // They must be propagated by register_new_node_with_optimizer(),
 571   // clone(), or the like.
 572   set_default_node_notes(NULL);
 573 
 574   for (;;) {
 575     int successes = Inline_Warm();
 576     if (failing())  return;
 577     if (successes == 0)  break;
 578   }
 579 
 580   // Drain the list.
 581   Finish_Warm();
 582 #ifndef PRODUCT
 583   if (_printer) {
 584     _printer->print_inlining(this);
 585   }
 586 #endif
 587 
 588   if (failing())  return;
 589   NOT_PRODUCT( verify_graph_edges(); )
 590 
 591   // Perform escape analysis
 592   if (_do_escape_analysis && ConnectionGraph::has_candidates(this)) {
 593     TracePhase t2("escapeAnalysis", &_t_escapeAnalysis, true);
 594     // Add ConP#NULL and ConN#NULL nodes before ConnectionGraph construction.
 595     PhaseGVN* igvn = initial_gvn();
 596     Node* oop_null = igvn->zerocon(T_OBJECT);
 597     Node* noop_null = igvn->zerocon(T_NARROWOOP);
 598 
 599     _congraph = new(comp_arena()) ConnectionGraph(this);
 600     bool has_non_escaping_obj = _congraph->compute_escape();
 601 
 602 #ifndef PRODUCT
 603     if (PrintEscapeAnalysis) {
 604       _congraph->dump();
 605     }
 606 #endif
 607     // Cleanup.
 608     if (oop_null->outcnt() == 0)
 609       igvn->hash_delete(oop_null);
 610     if (noop_null->outcnt() == 0)
 611       igvn->hash_delete(noop_null);
 612 
 613     if (!has_non_escaping_obj) {
 614       _congraph = NULL;
 615     }
 616 
 617     if (failing())  return;
 618   }
 619   // Now optimize
 620   Optimize();
 621   if (failing())  return;
 622   NOT_PRODUCT( verify_graph_edges(); )
 623 
 624 #ifndef PRODUCT
 625   if (PrintIdeal) {
 626     ttyLocker ttyl;  // keep the following output all in one block
 627     // This output goes directly to the tty, not the compiler log.
 628     // To enable tools to match it up with the compilation activity,
 629     // be sure to tag this tty output with the compile ID.
 630     if (xtty != NULL) {
 631       xtty->head("ideal compile_id='%d'%s", compile_id(),
 632                  is_osr_compilation()    ? " compile_kind='osr'" :
 633                  "");
 634     }
 635     root()->dump(9999);
 636     if (xtty != NULL) {
 637       xtty->tail("ideal");
 638     }
 639   }
 640 #endif
 641 
 642   // Now that we know the size of all the monitors we can add a fixed slot
 643   // for the original deopt pc.
 644 
 645   _orig_pc_slot =  fixed_slots();
 646   int next_slot = _orig_pc_slot + (sizeof(address) / VMRegImpl::stack_slot_size);
 647   set_fixed_slots(next_slot);
 648 
 649   // Now generate code
 650   Code_Gen();
 651   if (failing())  return;
 652 
 653   // Check if we want to skip execution of all compiled code.
 654   {
 655 #ifndef PRODUCT
 656     if (OptoNoExecute) {
 657       record_method_not_compilable("+OptoNoExecute");  // Flag as failed
 658       return;
 659     }
 660     TracePhase t2("install_code", &_t_registerMethod, TimeCompiler);
 661 #endif
 662 
 663     if (is_osr_compilation()) {
 664       _code_offsets.set_value(CodeOffsets::Verified_Entry, 0);
 665       _code_offsets.set_value(CodeOffsets::OSR_Entry, _first_block_size);
 666     } else {
 667       _code_offsets.set_value(CodeOffsets::Verified_Entry, _first_block_size);
 668       _code_offsets.set_value(CodeOffsets::OSR_Entry, 0);
 669     }
 670 
 671     env()->register_method(_method, _entry_bci,
 672                            &_code_offsets,
 673                            _orig_pc_slot_offset_in_bytes,
 674                            code_buffer(),
 675                            frame_size_in_words(), _oop_map_set,
 676                            &_handler_table, &_inc_table,
 677                            compiler,
 678                            env()->comp_level(),
 679                            true, /*has_debug_info*/
 680                            has_unsafe_access()
 681                            );
 682   }
 683 }
 684 
 685 //------------------------------Compile----------------------------------------
 686 // Compile a runtime stub
 687 Compile::Compile( ciEnv* ci_env,
 688                   TypeFunc_generator generator,
 689                   address stub_function,
 690                   const char *stub_name,
 691                   int is_fancy_jump,
 692                   bool pass_tls,
 693                   bool save_arg_registers,
 694                   bool return_pc )
 695   : Phase(Compiler),
 696     _env(ci_env),
 697     _log(ci_env->log()),
 698     _compile_id(-1),
 699     _save_argument_registers(save_arg_registers),
 700     _method(NULL),
 701     _stub_name(stub_name),
 702     _stub_function(stub_function),
 703     _stub_entry_point(NULL),
 704     _entry_bci(InvocationEntryBci),
 705     _initial_gvn(NULL),
 706     _for_igvn(NULL),
 707     _warm_calls(NULL),
 708     _orig_pc_slot(0),
 709     _orig_pc_slot_offset_in_bytes(0),
 710     _subsume_loads(true),
 711     _do_escape_analysis(false),
 712     _failure_reason(NULL),
 713     _code_buffer("Compile::Fill_buffer"),
 714     _node_bundling_limit(0),
 715     _node_bundling_base(NULL),
 716     _java_calls(0),
 717     _inner_loops(0),
 718 #ifndef PRODUCT
 719     _trace_opto_output(TraceOptoOutput),
 720     _printer(NULL),
 721 #endif
 722     _congraph(NULL) {
 723   C = this;
 724 
 725 #ifndef PRODUCT
 726   TraceTime t1(NULL, &_t_totalCompilation, TimeCompiler, false);
 727   TraceTime t2(NULL, &_t_stubCompilation, TimeCompiler, false);
 728   set_print_assembly(PrintFrameConverterAssembly);
 729   set_parsed_irreducible_loop(false);
 730 #endif
 731   CompileWrapper cw(this);
 732   Init(/*AliasLevel=*/ 0);
 733   init_tf((*generator)());
 734 
 735   {
 736     // The following is a dummy for the sake of GraphKit::gen_stub
 737     Unique_Node_List for_igvn(comp_arena());
 738     set_for_igvn(&for_igvn);  // not used, but some GraphKit guys push on this
 739     PhaseGVN gvn(Thread::current()->resource_area(),255);
 740     set_initial_gvn(&gvn);    // not significant, but GraphKit guys use it pervasively
 741     gvn.transform_no_reclaim(top());
 742 
 743     GraphKit kit;
 744     kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
 745   }
 746 
 747   NOT_PRODUCT( verify_graph_edges(); )
 748   Code_Gen();
 749   if (failing())  return;
 750 
 751 
 752   // Entry point will be accessed using compile->stub_entry_point();
 753   if (code_buffer() == NULL) {
 754     Matcher::soft_match_failure();
 755   } else {
 756     if (PrintAssembly && (WizardMode || Verbose))
 757       tty->print_cr("### Stub::%s", stub_name);
 758 
 759     if (!failing()) {
 760       assert(_fixed_slots == 0, "no fixed slots used for runtime stubs");
 761 
 762       // Make the NMethod
 763       // For now we mark the frame as never safe for profile stackwalking
 764       RuntimeStub *rs = RuntimeStub::new_runtime_stub(stub_name,
 765                                                       code_buffer(),
 766                                                       CodeOffsets::frame_never_safe,
 767                                                       // _code_offsets.value(CodeOffsets::Frame_Complete),
 768                                                       frame_size_in_words(),
 769                                                       _oop_map_set,
 770                                                       save_arg_registers);
 771       assert(rs != NULL && rs->is_runtime_stub(), "sanity check");
 772 
 773       _stub_entry_point = rs->entry_point();
 774     }
 775   }
 776 }
 777 
 778 #ifndef PRODUCT
 779 void print_opto_verbose_signature( const TypeFunc *j_sig, const char *stub_name ) {
 780   if(PrintOpto && Verbose) {
 781     tty->print("%s   ", stub_name); j_sig->print_flattened(); tty->cr();
 782   }
 783 }
 784 #endif
 785 
 786 void Compile::print_codes() {
 787 }
 788 
 789 //------------------------------Init-------------------------------------------
 790 // Prepare for a single compilation
 791 void Compile::Init(int aliaslevel) {
 792   _unique  = 0;
 793   _regalloc = NULL;
 794 
 795   _tf      = NULL;  // filled in later
 796   _top     = NULL;  // cached later
 797   _matcher = NULL;  // filled in later
 798   _cfg     = NULL;  // filled in later
 799 
 800   set_24_bit_selection_and_mode(Use24BitFP, false);
 801 
 802   _node_note_array = NULL;
 803   _default_node_notes = NULL;
 804 
 805   _immutable_memory = NULL; // filled in at first inquiry
 806 
 807   // Globally visible Nodes
 808   // First set TOP to NULL to give safe behavior during creation of RootNode
 809   set_cached_top_node(NULL);
 810   set_root(new (this, 3) RootNode());
 811   // Now that you have a Root to point to, create the real TOP
 812   set_cached_top_node( new (this, 1) ConNode(Type::TOP) );
 813   set_recent_alloc(NULL, NULL);
 814 
 815   // Create Debug Information Recorder to record scopes, oopmaps, etc.
 816   env()->set_oop_recorder(new OopRecorder(comp_arena()));
 817   env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
 818   env()->set_dependencies(new Dependencies(env()));
 819 
 820   _fixed_slots = 0;
 821   set_has_split_ifs(false);
 822   set_has_loops(has_method() && method()->has_loops()); // first approximation
 823   _deopt_happens = true;  // start out assuming the worst
 824   _trap_can_recompile = false;  // no traps emitted yet
 825   _major_progress = true; // start out assuming good things will happen
 826   set_has_unsafe_access(false);
 827   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
 828   set_decompile_count(0);
 829 
 830   set_do_freq_based_layout(BlockLayoutByFrequency || method_has_option("BlockLayoutByFrequency"));
 831   // Compilation level related initialization
 832   if (env()->comp_level() == CompLevel_fast_compile) {
 833     set_num_loop_opts(Tier1LoopOptsCount);
 834     set_do_inlining(Tier1Inline != 0);
 835     set_max_inline_size(Tier1MaxInlineSize);
 836     set_freq_inline_size(Tier1FreqInlineSize);
 837     set_do_scheduling(false);
 838     set_do_count_invocations(Tier1CountInvocations);
 839     set_do_method_data_update(Tier1UpdateMethodData);
 840   } else {
 841     assert(env()->comp_level() == CompLevel_full_optimization, "unknown comp level");
 842     set_num_loop_opts(LoopOptsCount);
 843     set_do_inlining(Inline);
 844     set_max_inline_size(MaxInlineSize);
 845     set_freq_inline_size(FreqInlineSize);
 846     set_do_scheduling(OptoScheduling);
 847     set_do_count_invocations(false);
 848     set_do_method_data_update(false);
 849   }
 850 
 851   if (debug_info()->recording_non_safepoints()) {
 852     set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
 853                         (comp_arena(), 8, 0, NULL));
 854     set_default_node_notes(Node_Notes::make(this));
 855   }
 856 
 857   // // -- Initialize types before each compile --
 858   // // Update cached type information
 859   // if( _method && _method->constants() )
 860   //   Type::update_loaded_types(_method, _method->constants());
 861 
 862   // Init alias_type map.
 863   if (!_do_escape_analysis && aliaslevel == 3)
 864     aliaslevel = 2;  // No unique types without escape analysis
 865   _AliasLevel = aliaslevel;
 866   const int grow_ats = 16;
 867   _max_alias_types = grow_ats;
 868   _alias_types   = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
 869   AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType,  grow_ats);
 870   Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
 871   {
 872     for (int i = 0; i < grow_ats; i++)  _alias_types[i] = &ats[i];
 873   }
 874   // Initialize the first few types.
 875   _alias_types[AliasIdxTop]->Init(AliasIdxTop, NULL);
 876   _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
 877   _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
 878   _num_alias_types = AliasIdxRaw+1;
 879   // Zero out the alias type cache.
 880   Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
 881   // A NULL adr_type hits in the cache right away.  Preload the right answer.
 882   probe_alias_cache(NULL)->_index = AliasIdxTop;
 883 
 884   _intrinsics = NULL;
 885   _macro_nodes = new GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
 886   register_library_intrinsics();
 887 }
 888 
 889 //---------------------------init_start----------------------------------------
 890 // Install the StartNode on this compile object.
 891 void Compile::init_start(StartNode* s) {
 892   if (failing())
 893     return; // already failing
 894   assert(s == start(), "");
 895 }
 896 
 897 StartNode* Compile::start() const {
 898   assert(!failing(), "");
 899   for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
 900     Node* start = root()->fast_out(i);
 901     if( start->is_Start() )
 902       return start->as_Start();
 903   }
 904   ShouldNotReachHere();
 905   return NULL;
 906 }
 907 
 908 //-------------------------------immutable_memory-------------------------------------
 909 // Access immutable memory
 910 Node* Compile::immutable_memory() {
 911   if (_immutable_memory != NULL) {
 912     return _immutable_memory;
 913   }
 914   StartNode* s = start();
 915   for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
 916     Node *p = s->fast_out(i);
 917     if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
 918       _immutable_memory = p;
 919       return _immutable_memory;
 920     }
 921   }
 922   ShouldNotReachHere();
 923   return NULL;
 924 }
 925 
 926 //----------------------set_cached_top_node------------------------------------
 927 // Install the cached top node, and make sure Node::is_top works correctly.
 928 void Compile::set_cached_top_node(Node* tn) {
 929   if (tn != NULL)  verify_top(tn);
 930   Node* old_top = _top;
 931   _top = tn;
 932   // Calling Node::setup_is_top allows the nodes the chance to adjust
 933   // their _out arrays.
 934   if (_top != NULL)     _top->setup_is_top();
 935   if (old_top != NULL)  old_top->setup_is_top();
 936   assert(_top == NULL || top()->is_top(), "");
 937 }
 938 
 939 #ifndef PRODUCT
 940 void Compile::verify_top(Node* tn) const {
 941   if (tn != NULL) {
 942     assert(tn->is_Con(), "top node must be a constant");
 943     assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
 944     assert(tn->in(0) != NULL, "must have live top node");
 945   }
 946 }
 947 #endif
 948 
 949 
 950 ///-------------------Managing Per-Node Debug & Profile Info-------------------
 951 
 952 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
 953   guarantee(arr != NULL, "");
 954   int num_blocks = arr->length();
 955   if (grow_by < num_blocks)  grow_by = num_blocks;
 956   int num_notes = grow_by * _node_notes_block_size;
 957   Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
 958   Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
 959   while (num_notes > 0) {
 960     arr->append(notes);
 961     notes     += _node_notes_block_size;
 962     num_notes -= _node_notes_block_size;
 963   }
 964   assert(num_notes == 0, "exact multiple, please");
 965 }
 966 
 967 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
 968   if (source == NULL || dest == NULL)  return false;
 969 
 970   if (dest->is_Con())
 971     return false;               // Do not push debug info onto constants.
 972 
 973 #ifdef ASSERT
 974   // Leave a bread crumb trail pointing to the original node:
 975   if (dest != NULL && dest != source && dest->debug_orig() == NULL) {
 976     dest->set_debug_orig(source);
 977   }
 978 #endif
 979 
 980   if (node_note_array() == NULL)
 981     return false;               // Not collecting any notes now.
 982 
 983   // This is a copy onto a pre-existing node, which may already have notes.
 984   // If both nodes have notes, do not overwrite any pre-existing notes.
 985   Node_Notes* source_notes = node_notes_at(source->_idx);
 986   if (source_notes == NULL || source_notes->is_clear())  return false;
 987   Node_Notes* dest_notes   = node_notes_at(dest->_idx);
 988   if (dest_notes == NULL || dest_notes->is_clear()) {
 989     return set_node_notes_at(dest->_idx, source_notes);
 990   }
 991 
 992   Node_Notes merged_notes = (*source_notes);
 993   // The order of operations here ensures that dest notes will win...
 994   merged_notes.update_from(dest_notes);
 995   return set_node_notes_at(dest->_idx, &merged_notes);
 996 }
 997 
 998 
 999 //--------------------------allow_range_check_smearing-------------------------
1000 // Gating condition for coalescing similar range checks.
1001 // Sometimes we try 'speculatively' replacing a series of a range checks by a
1002 // single covering check that is at least as strong as any of them.
1003 // If the optimization succeeds, the simplified (strengthened) range check
1004 // will always succeed.  If it fails, we will deopt, and then give up
1005 // on the optimization.
1006 bool Compile::allow_range_check_smearing() const {
1007   // If this method has already thrown a range-check,
1008   // assume it was because we already tried range smearing
1009   // and it failed.
1010   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
1011   return !already_trapped;
1012 }
1013 
1014 
1015 //------------------------------flatten_alias_type-----------------------------
1016 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
1017   int offset = tj->offset();
1018   TypePtr::PTR ptr = tj->ptr();
1019 
1020   // Known instance (scalarizable allocation) alias only with itself.
1021   bool is_known_inst = tj->isa_oopptr() != NULL &&
1022                        tj->is_oopptr()->is_known_instance();
1023 
1024   // Process weird unsafe references.
1025   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
1026     assert(InlineUnsafeOps, "indeterminate pointers come only from unsafe ops");
1027     assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
1028     tj = TypeOopPtr::BOTTOM;
1029     ptr = tj->ptr();
1030     offset = tj->offset();
1031   }
1032 
1033   // Array pointers need some flattening
1034   const TypeAryPtr *ta = tj->isa_aryptr();
1035   if( ta && is_known_inst ) {
1036     if ( offset != Type::OffsetBot &&
1037          offset > arrayOopDesc::length_offset_in_bytes() ) {
1038       offset = Type::OffsetBot; // Flatten constant access into array body only
1039       tj = ta = TypeAryPtr::make(ptr, ta->ary(), ta->klass(), true, offset, ta->instance_id());
1040     }
1041   } else if( ta && _AliasLevel >= 2 ) {
1042     // For arrays indexed by constant indices, we flatten the alias
1043     // space to include all of the array body.  Only the header, klass
1044     // and array length can be accessed un-aliased.
1045     if( offset != Type::OffsetBot ) {
1046       if( ta->const_oop() ) { // methodDataOop or methodOop
1047         offset = Type::OffsetBot;   // Flatten constant access into array body
1048         tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),ta->ary(),ta->klass(),false,offset);
1049       } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
1050         // range is OK as-is.
1051         tj = ta = TypeAryPtr::RANGE;
1052       } else if( offset == oopDesc::klass_offset_in_bytes() ) {
1053         tj = TypeInstPtr::KLASS; // all klass loads look alike
1054         ta = TypeAryPtr::RANGE; // generic ignored junk
1055         ptr = TypePtr::BotPTR;
1056       } else if( offset == oopDesc::mark_offset_in_bytes() ) {
1057         tj = TypeInstPtr::MARK;
1058         ta = TypeAryPtr::RANGE; // generic ignored junk
1059         ptr = TypePtr::BotPTR;
1060       } else {                  // Random constant offset into array body
1061         offset = Type::OffsetBot;   // Flatten constant access into array body
1062         tj = ta = TypeAryPtr::make(ptr,ta->ary(),ta->klass(),false,offset);
1063       }
1064     }
1065     // Arrays of fixed size alias with arrays of unknown size.
1066     if (ta->size() != TypeInt::POS) {
1067       const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
1068       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,ta->klass(),false,offset);
1069     }
1070     // Arrays of known objects become arrays of unknown objects.
1071     if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
1072       const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
1073       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1074     }
1075     if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
1076       const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
1077       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1078     }
1079     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
1080     // cannot be distinguished by bytecode alone.
1081     if (ta->elem() == TypeInt::BOOL) {
1082       const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
1083       ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
1084       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,offset);
1085     }
1086     // During the 2nd round of IterGVN, NotNull castings are removed.
1087     // Make sure the Bottom and NotNull variants alias the same.
1088     // Also, make sure exact and non-exact variants alias the same.
1089     if( ptr == TypePtr::NotNull || ta->klass_is_exact() ) {
1090       if (ta->const_oop()) {
1091         tj = ta = TypeAryPtr::make(TypePtr::Constant,ta->const_oop(),ta->ary(),ta->klass(),false,offset);
1092       } else {
1093         tj = ta = TypeAryPtr::make(TypePtr::BotPTR,ta->ary(),ta->klass(),false,offset);
1094       }
1095     }
1096   }
1097 
1098   // Oop pointers need some flattening
1099   const TypeInstPtr *to = tj->isa_instptr();
1100   if( to && _AliasLevel >= 2 && to != TypeOopPtr::BOTTOM ) {
1101     if( ptr == TypePtr::Constant ) {
1102       // No constant oop pointers (such as Strings); they alias with
1103       // unknown strings.
1104       assert(!is_known_inst, "not scalarizable allocation");
1105       tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1106     } else if( is_known_inst ) {
1107       tj = to; // Keep NotNull and klass_is_exact for instance type
1108     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
1109       // During the 2nd round of IterGVN, NotNull castings are removed.
1110       // Make sure the Bottom and NotNull variants alias the same.
1111       // Also, make sure exact and non-exact variants alias the same.
1112       tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1113     }
1114     // Canonicalize the holder of this field
1115     ciInstanceKlass *k = to->klass()->as_instance_klass();
1116     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
1117       // First handle header references such as a LoadKlassNode, even if the
1118       // object's klass is unloaded at compile time (4965979).
1119       if (!is_known_inst) { // Do it only for non-instance types
1120         tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, NULL, offset);
1121       }
1122     } else if (offset < 0 || offset >= k->size_helper() * wordSize) {
1123       to = NULL;
1124       tj = TypeOopPtr::BOTTOM;
1125       offset = tj->offset();
1126     } else {
1127       ciInstanceKlass *canonical_holder = k->get_canonical_holder(offset);
1128       if (!k->equals(canonical_holder) || tj->offset() != offset) {
1129         if( is_known_inst ) {
1130           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, true, NULL, offset, to->instance_id());
1131         } else {
1132           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, false, NULL, offset);
1133         }
1134       }
1135     }
1136   }
1137 
1138   // Klass pointers to object array klasses need some flattening
1139   const TypeKlassPtr *tk = tj->isa_klassptr();
1140   if( tk ) {
1141     // If we are referencing a field within a Klass, we need
1142     // to assume the worst case of an Object.  Both exact and
1143     // inexact types must flatten to the same alias class.
1144     // Since the flattened result for a klass is defined to be
1145     // precisely java.lang.Object, use a constant ptr.
1146     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
1147 
1148       tj = tk = TypeKlassPtr::make(TypePtr::Constant,
1149                                    TypeKlassPtr::OBJECT->klass(),
1150                                    offset);
1151     }
1152 
1153     ciKlass* klass = tk->klass();
1154     if( klass->is_obj_array_klass() ) {
1155       ciKlass* k = TypeAryPtr::OOPS->klass();
1156       if( !k || !k->is_loaded() )                  // Only fails for some -Xcomp runs
1157         k = TypeInstPtr::BOTTOM->klass();
1158       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, k, offset );
1159     }
1160 
1161     // Check for precise loads from the primary supertype array and force them
1162     // to the supertype cache alias index.  Check for generic array loads from
1163     // the primary supertype array and also force them to the supertype cache
1164     // alias index.  Since the same load can reach both, we need to merge
1165     // these 2 disparate memories into the same alias class.  Since the
1166     // primary supertype array is read-only, there's no chance of confusion
1167     // where we bypass an array load and an array store.
1168     uint off2 = offset - Klass::primary_supers_offset_in_bytes();
1169     if( offset == Type::OffsetBot ||
1170         off2 < Klass::primary_super_limit()*wordSize ) {
1171       offset = sizeof(oopDesc) +Klass::secondary_super_cache_offset_in_bytes();
1172       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, tk->klass(), offset );
1173     }
1174   }
1175 
1176   // Flatten all Raw pointers together.
1177   if (tj->base() == Type::RawPtr)
1178     tj = TypeRawPtr::BOTTOM;
1179 
1180   if (tj->base() == Type::AnyPtr)
1181     tj = TypePtr::BOTTOM;      // An error, which the caller must check for.
1182 
1183   // Flatten all to bottom for now
1184   switch( _AliasLevel ) {
1185   case 0:
1186     tj = TypePtr::BOTTOM;
1187     break;
1188   case 1:                       // Flatten to: oop, static, field or array
1189     switch (tj->base()) {
1190     //case Type::AryPtr: tj = TypeAryPtr::RANGE;    break;
1191     case Type::RawPtr:   tj = TypeRawPtr::BOTTOM;   break;
1192     case Type::AryPtr:   // do not distinguish arrays at all
1193     case Type::InstPtr:  tj = TypeInstPtr::BOTTOM;  break;
1194     case Type::KlassPtr: tj = TypeKlassPtr::OBJECT; break;
1195     case Type::AnyPtr:   tj = TypePtr::BOTTOM;      break;  // caller checks it
1196     default: ShouldNotReachHere();
1197     }
1198     break;
1199   case 2:                       // No collapsing at level 2; keep all splits
1200   case 3:                       // No collapsing at level 3; keep all splits
1201     break;
1202   default:
1203     Unimplemented();
1204   }
1205 
1206   offset = tj->offset();
1207   assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
1208 
1209   assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
1210           (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
1211           (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
1212           (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
1213           (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1214           (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1215           (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr)  ,
1216           "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
1217   assert( tj->ptr() != TypePtr::TopPTR &&
1218           tj->ptr() != TypePtr::AnyNull &&
1219           tj->ptr() != TypePtr::Null, "No imprecise addresses" );
1220 //    assert( tj->ptr() != TypePtr::Constant ||
1221 //            tj->base() == Type::RawPtr ||
1222 //            tj->base() == Type::KlassPtr, "No constant oop addresses" );
1223 
1224   return tj;
1225 }
1226 
1227 void Compile::AliasType::Init(int i, const TypePtr* at) {
1228   _index = i;
1229   _adr_type = at;
1230   _field = NULL;
1231   _is_rewritable = true; // default
1232   const TypeOopPtr *atoop = (at != NULL) ? at->isa_oopptr() : NULL;
1233   if (atoop != NULL && atoop->is_known_instance()) {
1234     const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
1235     _general_index = Compile::current()->get_alias_index(gt);
1236   } else {
1237     _general_index = 0;
1238   }
1239 }
1240 
1241 //---------------------------------print_on------------------------------------
1242 #ifndef PRODUCT
1243 void Compile::AliasType::print_on(outputStream* st) {
1244   if (index() < 10)
1245         st->print("@ <%d> ", index());
1246   else  st->print("@ <%d>",  index());
1247   st->print(is_rewritable() ? "   " : " RO");
1248   int offset = adr_type()->offset();
1249   if (offset == Type::OffsetBot)
1250         st->print(" +any");
1251   else  st->print(" +%-3d", offset);
1252   st->print(" in ");
1253   adr_type()->dump_on(st);
1254   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
1255   if (field() != NULL && tjp) {
1256     if (tjp->klass()  != field()->holder() ||
1257         tjp->offset() != field()->offset_in_bytes()) {
1258       st->print(" != ");
1259       field()->print();
1260       st->print(" ***");
1261     }
1262   }
1263 }
1264 
1265 void print_alias_types() {
1266   Compile* C = Compile::current();
1267   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
1268   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
1269     C->alias_type(idx)->print_on(tty);
1270     tty->cr();
1271   }
1272 }
1273 #endif
1274 
1275 
1276 //----------------------------probe_alias_cache--------------------------------
1277 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
1278   intptr_t key = (intptr_t) adr_type;
1279   key ^= key >> logAliasCacheSize;
1280   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
1281 }
1282 
1283 
1284 //-----------------------------grow_alias_types--------------------------------
1285 void Compile::grow_alias_types() {
1286   const int old_ats  = _max_alias_types; // how many before?
1287   const int new_ats  = old_ats;          // how many more?
1288   const int grow_ats = old_ats+new_ats;  // how many now?
1289   _max_alias_types = grow_ats;
1290   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
1291   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
1292   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
1293   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
1294 }
1295 
1296 
1297 //--------------------------------find_alias_type------------------------------
1298 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create) {
1299   if (_AliasLevel == 0)
1300     return alias_type(AliasIdxBot);
1301 
1302   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1303   if (ace->_adr_type == adr_type) {
1304     return alias_type(ace->_index);
1305   }
1306 
1307   // Handle special cases.
1308   if (adr_type == NULL)             return alias_type(AliasIdxTop);
1309   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
1310 
1311   // Do it the slow way.
1312   const TypePtr* flat = flatten_alias_type(adr_type);
1313 
1314 #ifdef ASSERT
1315   assert(flat == flatten_alias_type(flat), "idempotent");
1316   assert(flat != TypePtr::BOTTOM,     "cannot alias-analyze an untyped ptr");
1317   if (flat->isa_oopptr() && !flat->isa_klassptr()) {
1318     const TypeOopPtr* foop = flat->is_oopptr();
1319     // Scalarizable allocations have exact klass always.
1320     bool exact = !foop->klass_is_exact() || foop->is_known_instance();
1321     const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
1322     assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type");
1323   }
1324   assert(flat == flatten_alias_type(flat), "exact bit doesn't matter");
1325 #endif
1326 
1327   int idx = AliasIdxTop;
1328   for (int i = 0; i < num_alias_types(); i++) {
1329     if (alias_type(i)->adr_type() == flat) {
1330       idx = i;
1331       break;
1332     }
1333   }
1334 
1335   if (idx == AliasIdxTop) {
1336     if (no_create)  return NULL;
1337     // Grow the array if necessary.
1338     if (_num_alias_types == _max_alias_types)  grow_alias_types();
1339     // Add a new alias type.
1340     idx = _num_alias_types++;
1341     _alias_types[idx]->Init(idx, flat);
1342     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
1343     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
1344     if (flat->isa_instptr()) {
1345       if (flat->offset() == java_lang_Class::klass_offset_in_bytes()
1346           && flat->is_instptr()->klass() == env()->Class_klass())
1347         alias_type(idx)->set_rewritable(false);
1348     }
1349     if (flat->isa_klassptr()) {
1350       if (flat->offset() == Klass::super_check_offset_offset_in_bytes() + (int)sizeof(oopDesc))
1351         alias_type(idx)->set_rewritable(false);
1352       if (flat->offset() == Klass::modifier_flags_offset_in_bytes() + (int)sizeof(oopDesc))
1353         alias_type(idx)->set_rewritable(false);
1354       if (flat->offset() == Klass::access_flags_offset_in_bytes() + (int)sizeof(oopDesc))
1355         alias_type(idx)->set_rewritable(false);
1356       if (flat->offset() == Klass::java_mirror_offset_in_bytes() + (int)sizeof(oopDesc))
1357         alias_type(idx)->set_rewritable(false);
1358     }
1359     // %%% (We would like to finalize JavaThread::threadObj_offset(),
1360     // but the base pointer type is not distinctive enough to identify
1361     // references into JavaThread.)
1362 
1363     // Check for final instance fields.
1364     const TypeInstPtr* tinst = flat->isa_instptr();
1365     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
1366       ciInstanceKlass *k = tinst->klass()->as_instance_klass();
1367       ciField* field = k->get_field_by_offset(tinst->offset(), false);
1368       // Set field() and is_rewritable() attributes.
1369       if (field != NULL)  alias_type(idx)->set_field(field);
1370     }
1371     const TypeKlassPtr* tklass = flat->isa_klassptr();
1372     // Check for final static fields.
1373     if (tklass && tklass->klass()->is_instance_klass()) {
1374       ciInstanceKlass *k = tklass->klass()->as_instance_klass();
1375       ciField* field = k->get_field_by_offset(tklass->offset(), true);
1376       // Set field() and is_rewritable() attributes.
1377       if (field != NULL)   alias_type(idx)->set_field(field);
1378     }
1379   }
1380 
1381   // Fill the cache for next time.
1382   ace->_adr_type = adr_type;
1383   ace->_index    = idx;
1384   assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
1385 
1386   // Might as well try to fill the cache for the flattened version, too.
1387   AliasCacheEntry* face = probe_alias_cache(flat);
1388   if (face->_adr_type == NULL) {
1389     face->_adr_type = flat;
1390     face->_index    = idx;
1391     assert(alias_type(flat) == alias_type(idx), "flat type must work too");
1392   }
1393 
1394   return alias_type(idx);
1395 }
1396 
1397 
1398 Compile::AliasType* Compile::alias_type(ciField* field) {
1399   const TypeOopPtr* t;
1400   if (field->is_static())
1401     t = TypeKlassPtr::make(field->holder());
1402   else
1403     t = TypeOopPtr::make_from_klass_raw(field->holder());
1404   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()));
1405   assert(field->is_final() == !atp->is_rewritable(), "must get the rewritable bits correct");
1406   return atp;
1407 }
1408 
1409 
1410 //------------------------------have_alias_type--------------------------------
1411 bool Compile::have_alias_type(const TypePtr* adr_type) {
1412   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1413   if (ace->_adr_type == adr_type) {
1414     return true;
1415   }
1416 
1417   // Handle special cases.
1418   if (adr_type == NULL)             return true;
1419   if (adr_type == TypePtr::BOTTOM)  return true;
1420 
1421   return find_alias_type(adr_type, true) != NULL;
1422 }
1423 
1424 //-----------------------------must_alias--------------------------------------
1425 // True if all values of the given address type are in the given alias category.
1426 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
1427   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1428   if (adr_type == NULL)                 return true;  // NULL serves as TypePtr::TOP
1429   if (alias_idx == AliasIdxTop)         return false; // the empty category
1430   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
1431 
1432   // the only remaining possible overlap is identity
1433   int adr_idx = get_alias_index(adr_type);
1434   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1435   assert(adr_idx == alias_idx ||
1436          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
1437           && adr_type                       != TypeOopPtr::BOTTOM),
1438          "should not be testing for overlap with an unsafe pointer");
1439   return adr_idx == alias_idx;
1440 }
1441 
1442 //------------------------------can_alias--------------------------------------
1443 // True if any values of the given address type are in the given alias category.
1444 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
1445   if (alias_idx == AliasIdxTop)         return false; // the empty category
1446   if (adr_type == NULL)                 return false; // NULL serves as TypePtr::TOP
1447   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1448   if (adr_type->base() == Type::AnyPtr) return true;  // TypePtr::BOTTOM or its twins
1449 
1450   // the only remaining possible overlap is identity
1451   int adr_idx = get_alias_index(adr_type);
1452   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1453   return adr_idx == alias_idx;
1454 }
1455 
1456 
1457 
1458 //---------------------------pop_warm_call-------------------------------------
1459 WarmCallInfo* Compile::pop_warm_call() {
1460   WarmCallInfo* wci = _warm_calls;
1461   if (wci != NULL)  _warm_calls = wci->remove_from(wci);
1462   return wci;
1463 }
1464 
1465 //----------------------------Inline_Warm--------------------------------------
1466 int Compile::Inline_Warm() {
1467   // If there is room, try to inline some more warm call sites.
1468   // %%% Do a graph index compaction pass when we think we're out of space?
1469   if (!InlineWarmCalls)  return 0;
1470 
1471   int calls_made_hot = 0;
1472   int room_to_grow   = NodeCountInliningCutoff - unique();
1473   int amount_to_grow = MIN2(room_to_grow, (int)NodeCountInliningStep);
1474   int amount_grown   = 0;
1475   WarmCallInfo* call;
1476   while (amount_to_grow > 0 && (call = pop_warm_call()) != NULL) {
1477     int est_size = (int)call->size();
1478     if (est_size > (room_to_grow - amount_grown)) {
1479       // This one won't fit anyway.  Get rid of it.
1480       call->make_cold();
1481       continue;
1482     }
1483     call->make_hot();
1484     calls_made_hot++;
1485     amount_grown   += est_size;
1486     amount_to_grow -= est_size;
1487   }
1488 
1489   if (calls_made_hot > 0)  set_major_progress();
1490   return calls_made_hot;
1491 }
1492 
1493 
1494 //----------------------------Finish_Warm--------------------------------------
1495 void Compile::Finish_Warm() {
1496   if (!InlineWarmCalls)  return;
1497   if (failing())  return;
1498   if (warm_calls() == NULL)  return;
1499 
1500   // Clean up loose ends, if we are out of space for inlining.
1501   WarmCallInfo* call;
1502   while ((call = pop_warm_call()) != NULL) {
1503     call->make_cold();
1504   }
1505 }
1506 
1507 
1508 //------------------------------Optimize---------------------------------------
1509 // Given a graph, optimize it.
1510 void Compile::Optimize() {
1511   TracePhase t1("optimizer", &_t_optimizer, true);
1512 
1513 #ifndef PRODUCT
1514   if (env()->break_at_compile()) {
1515     BREAKPOINT;
1516   }
1517 
1518 #endif
1519 
1520   ResourceMark rm;
1521   int          loop_opts_cnt;
1522 
1523   NOT_PRODUCT( verify_graph_edges(); )
1524 
1525   print_method("After Parsing");
1526 
1527  {
1528   // Iterative Global Value Numbering, including ideal transforms
1529   // Initialize IterGVN with types and values from parse-time GVN
1530   PhaseIterGVN igvn(initial_gvn());
1531   {
1532     NOT_PRODUCT( TracePhase t2("iterGVN", &_t_iterGVN, TimeCompiler); )
1533     igvn.optimize();
1534   }
1535 
1536   print_method("Iter GVN 1", 2);
1537 
1538   if (failing())  return;
1539 
1540   // Loop transforms on the ideal graph.  Range Check Elimination,
1541   // peeling, unrolling, etc.
1542 
1543   // Set loop opts counter
1544   loop_opts_cnt = num_loop_opts();
1545   if((loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
1546     {
1547       TracePhase t2("idealLoop", &_t_idealLoop, true);
1548       PhaseIdealLoop ideal_loop( igvn, NULL, true );
1549       loop_opts_cnt--;
1550       if (major_progress()) print_method("PhaseIdealLoop 1", 2);
1551       if (failing())  return;
1552     }
1553     // Loop opts pass if partial peeling occurred in previous pass
1554     if(PartialPeelLoop && major_progress() && (loop_opts_cnt > 0)) {
1555       TracePhase t3("idealLoop", &_t_idealLoop, true);
1556       PhaseIdealLoop ideal_loop( igvn, NULL, false );
1557       loop_opts_cnt--;
1558       if (major_progress()) print_method("PhaseIdealLoop 2", 2);
1559       if (failing())  return;
1560     }
1561     // Loop opts pass for loop-unrolling before CCP
1562     if(major_progress() && (loop_opts_cnt > 0)) {
1563       TracePhase t4("idealLoop", &_t_idealLoop, true);
1564       PhaseIdealLoop ideal_loop( igvn, NULL, false );
1565       loop_opts_cnt--;
1566       if (major_progress()) print_method("PhaseIdealLoop 3", 2);
1567     }
1568   }
1569   if (failing())  return;
1570 
1571   // Conditional Constant Propagation;
1572   PhaseCCP ccp( &igvn );
1573   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
1574   {
1575     TracePhase t2("ccp", &_t_ccp, true);
1576     ccp.do_transform();
1577   }
1578   print_method("PhaseCPP 1", 2);
1579 
1580   assert( true, "Break here to ccp.dump_old2new_map()");
1581 
1582   // Iterative Global Value Numbering, including ideal transforms
1583   {
1584     NOT_PRODUCT( TracePhase t2("iterGVN2", &_t_iterGVN2, TimeCompiler); )
1585     igvn = ccp;
1586     igvn.optimize();
1587   }
1588 
1589   print_method("Iter GVN 2", 2);
1590 
1591   if (failing())  return;
1592 
1593   // Loop transforms on the ideal graph.  Range Check Elimination,
1594   // peeling, unrolling, etc.
1595   if(loop_opts_cnt > 0) {
1596     debug_only( int cnt = 0; );
1597     while(major_progress() && (loop_opts_cnt > 0)) {
1598       TracePhase t2("idealLoop", &_t_idealLoop, true);
1599       assert( cnt++ < 40, "infinite cycle in loop optimization" );
1600       PhaseIdealLoop ideal_loop( igvn, NULL, true );
1601       loop_opts_cnt--;
1602       if (major_progress()) print_method("PhaseIdealLoop iterations", 2);
1603       if (failing())  return;
1604     }
1605   }
1606   {
1607     NOT_PRODUCT( TracePhase t2("macroExpand", &_t_macroExpand, TimeCompiler); )
1608     PhaseMacroExpand  mex(igvn);
1609     if (mex.expand_macro_nodes()) {
1610       assert(failing(), "must bail out w/ explicit message");
1611       return;
1612     }
1613   }
1614 
1615  } // (End scope of igvn; run destructor if necessary for asserts.)
1616 
1617   // A method with only infinite loops has no edges entering loops from root
1618   {
1619     NOT_PRODUCT( TracePhase t2("graphReshape", &_t_graphReshaping, TimeCompiler); )
1620     if (final_graph_reshaping()) {
1621       assert(failing(), "must bail out w/ explicit message");
1622       return;
1623     }
1624   }
1625 
1626   print_method("Optimize finished", 2);
1627 }
1628 
1629 
1630 //------------------------------Code_Gen---------------------------------------
1631 // Given a graph, generate code for it
1632 void Compile::Code_Gen() {
1633   if (failing())  return;
1634 
1635   // Perform instruction selection.  You might think we could reclaim Matcher
1636   // memory PDQ, but actually the Matcher is used in generating spill code.
1637   // Internals of the Matcher (including some VectorSets) must remain live
1638   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
1639   // set a bit in reclaimed memory.
1640 
1641   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
1642   // nodes.  Mapping is only valid at the root of each matched subtree.
1643   NOT_PRODUCT( verify_graph_edges(); )
1644 
1645   Node_List proj_list;
1646   Matcher m(proj_list);
1647   _matcher = &m;
1648   {
1649     TracePhase t2("matcher", &_t_matcher, true);
1650     m.match();
1651   }
1652   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
1653   // nodes.  Mapping is only valid at the root of each matched subtree.
1654   NOT_PRODUCT( verify_graph_edges(); )
1655 
1656   // If you have too many nodes, or if matching has failed, bail out
1657   check_node_count(0, "out of nodes matching instructions");
1658   if (failing())  return;
1659 
1660   // Build a proper-looking CFG
1661   PhaseCFG cfg(node_arena(), root(), m);
1662   _cfg = &cfg;
1663   {
1664     NOT_PRODUCT( TracePhase t2("scheduler", &_t_scheduler, TimeCompiler); )
1665     cfg.Dominators();
1666     if (failing())  return;
1667 
1668     NOT_PRODUCT( verify_graph_edges(); )
1669 
1670     cfg.Estimate_Block_Frequency();
1671     cfg.GlobalCodeMotion(m,unique(),proj_list);
1672 
1673     print_method("Global code motion", 2);
1674 
1675     if (failing())  return;
1676     NOT_PRODUCT( verify_graph_edges(); )
1677 
1678     debug_only( cfg.verify(); )
1679   }
1680   NOT_PRODUCT( verify_graph_edges(); )
1681 
1682   PhaseChaitin regalloc(unique(),cfg,m);
1683   _regalloc = &regalloc;
1684   {
1685     TracePhase t2("regalloc", &_t_registerAllocation, true);
1686     // Perform any platform dependent preallocation actions.  This is used,
1687     // for example, to avoid taking an implicit null pointer exception
1688     // using the frame pointer on win95.
1689     _regalloc->pd_preallocate_hook();
1690 
1691     // Perform register allocation.  After Chaitin, use-def chains are
1692     // no longer accurate (at spill code) and so must be ignored.
1693     // Node->LRG->reg mappings are still accurate.
1694     _regalloc->Register_Allocate();
1695 
1696     // Bail out if the allocator builds too many nodes
1697     if (failing())  return;
1698   }
1699 
1700   // Prior to register allocation we kept empty basic blocks in case the
1701   // the allocator needed a place to spill.  After register allocation we
1702   // are not adding any new instructions.  If any basic block is empty, we
1703   // can now safely remove it.
1704   {
1705     NOT_PRODUCT( TracePhase t2("blockOrdering", &_t_blockOrdering, TimeCompiler); )
1706     cfg.remove_empty();
1707     if (do_freq_based_layout()) {
1708       PhaseBlockLayout layout(cfg);
1709     } else {
1710       cfg.set_loop_alignment();
1711     }
1712     cfg.fixup_flow();
1713   }
1714 
1715   // Perform any platform dependent postallocation verifications.
1716   debug_only( _regalloc->pd_postallocate_verify_hook(); )
1717 
1718   // Apply peephole optimizations
1719   if( OptoPeephole ) {
1720     NOT_PRODUCT( TracePhase t2("peephole", &_t_peephole, TimeCompiler); )
1721     PhasePeephole peep( _regalloc, cfg);
1722     peep.do_transform();
1723   }
1724 
1725   // Convert Nodes to instruction bits in a buffer
1726   {
1727     // %%%% workspace merge brought two timers together for one job
1728     TracePhase t2a("output", &_t_output, true);
1729     NOT_PRODUCT( TraceTime t2b(NULL, &_t_codeGeneration, TimeCompiler, false); )
1730     Output();
1731   }
1732 
1733   print_method("Final Code");
1734 
1735   // He's dead, Jim.
1736   _cfg     = (PhaseCFG*)0xdeadbeef;
1737   _regalloc = (PhaseChaitin*)0xdeadbeef;
1738 }
1739 
1740 
1741 //------------------------------dump_asm---------------------------------------
1742 // Dump formatted assembly
1743 #ifndef PRODUCT
1744 void Compile::dump_asm(int *pcs, uint pc_limit) {
1745   bool cut_short = false;
1746   tty->print_cr("#");
1747   tty->print("#  ");  _tf->dump();  tty->cr();
1748   tty->print_cr("#");
1749 
1750   // For all blocks
1751   int pc = 0x0;                 // Program counter
1752   char starts_bundle = ' ';
1753   _regalloc->dump_frame();
1754 
1755   Node *n = NULL;
1756   for( uint i=0; i<_cfg->_num_blocks; i++ ) {
1757     if (VMThread::should_terminate()) { cut_short = true; break; }
1758     Block *b = _cfg->_blocks[i];
1759     if (b->is_connector() && !Verbose) continue;
1760     n = b->_nodes[0];
1761     if (pcs && n->_idx < pc_limit)
1762       tty->print("%3.3x   ", pcs[n->_idx]);
1763     else
1764       tty->print("      ");
1765     b->dump_head( &_cfg->_bbs );
1766     if (b->is_connector()) {
1767       tty->print_cr("        # Empty connector block");
1768     } else if (b->num_preds() == 2 && b->pred(1)->is_CatchProj() && b->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
1769       tty->print_cr("        # Block is sole successor of call");
1770     }
1771 
1772     // For all instructions
1773     Node *delay = NULL;
1774     for( uint j = 0; j<b->_nodes.size(); j++ ) {
1775       if (VMThread::should_terminate()) { cut_short = true; break; }
1776       n = b->_nodes[j];
1777       if (valid_bundle_info(n)) {
1778         Bundle *bundle = node_bundling(n);
1779         if (bundle->used_in_unconditional_delay()) {
1780           delay = n;
1781           continue;
1782         }
1783         if (bundle->starts_bundle())
1784           starts_bundle = '+';
1785       }
1786 
1787       if (WizardMode) n->dump();
1788 
1789       if( !n->is_Region() &&    // Dont print in the Assembly
1790           !n->is_Phi() &&       // a few noisely useless nodes
1791           !n->is_Proj() &&
1792           !n->is_MachTemp() &&
1793           !n->is_Catch() &&     // Would be nice to print exception table targets
1794           !n->is_MergeMem() &&  // Not very interesting
1795           !n->is_top() &&       // Debug info table constants
1796           !(n->is_Con() && !n->is_Mach())// Debug info table constants
1797           ) {
1798         if (pcs && n->_idx < pc_limit)
1799           tty->print("%3.3x", pcs[n->_idx]);
1800         else
1801           tty->print("   ");
1802         tty->print(" %c ", starts_bundle);
1803         starts_bundle = ' ';
1804         tty->print("\t");
1805         n->format(_regalloc, tty);
1806         tty->cr();
1807       }
1808 
1809       // If we have an instruction with a delay slot, and have seen a delay,
1810       // then back up and print it
1811       if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
1812         assert(delay != NULL, "no unconditional delay instruction");
1813         if (WizardMode) delay->dump();
1814 
1815         if (node_bundling(delay)->starts_bundle())
1816           starts_bundle = '+';
1817         if (pcs && n->_idx < pc_limit)
1818           tty->print("%3.3x", pcs[n->_idx]);
1819         else
1820           tty->print("   ");
1821         tty->print(" %c ", starts_bundle);
1822         starts_bundle = ' ';
1823         tty->print("\t");
1824         delay->format(_regalloc, tty);
1825         tty->print_cr("");
1826         delay = NULL;
1827       }
1828 
1829       // Dump the exception table as well
1830       if( n->is_Catch() && (Verbose || WizardMode) ) {
1831         // Print the exception table for this offset
1832         _handler_table.print_subtable_for(pc);
1833       }
1834     }
1835 
1836     if (pcs && n->_idx < pc_limit)
1837       tty->print_cr("%3.3x", pcs[n->_idx]);
1838     else
1839       tty->print_cr("");
1840 
1841     assert(cut_short || delay == NULL, "no unconditional delay branch");
1842 
1843   } // End of per-block dump
1844   tty->print_cr("");
1845 
1846   if (cut_short)  tty->print_cr("*** disassembly is cut short ***");
1847 }
1848 #endif
1849 
1850 //------------------------------Final_Reshape_Counts---------------------------
1851 // This class defines counters to help identify when a method
1852 // may/must be executed using hardware with only 24-bit precision.
1853 struct Final_Reshape_Counts : public StackObj {
1854   int  _call_count;             // count non-inlined 'common' calls
1855   int  _float_count;            // count float ops requiring 24-bit precision
1856   int  _double_count;           // count double ops requiring more precision
1857   int  _java_call_count;        // count non-inlined 'java' calls
1858   int  _inner_loop_count;       // count loops which need alignment
1859   VectorSet _visited;           // Visitation flags
1860   Node_List _tests;             // Set of IfNodes & PCTableNodes
1861 
1862   Final_Reshape_Counts() :
1863     _call_count(0), _float_count(0), _double_count(0),
1864     _java_call_count(0), _inner_loop_count(0),
1865     _visited( Thread::current()->resource_area() ) { }
1866 
1867   void inc_call_count  () { _call_count  ++; }
1868   void inc_float_count () { _float_count ++; }
1869   void inc_double_count() { _double_count++; }
1870   void inc_java_call_count() { _java_call_count++; }
1871   void inc_inner_loop_count() { _inner_loop_count++; }
1872 
1873   int  get_call_count  () const { return _call_count  ; }
1874   int  get_float_count () const { return _float_count ; }
1875   int  get_double_count() const { return _double_count; }
1876   int  get_java_call_count() const { return _java_call_count; }
1877   int  get_inner_loop_count() const { return _inner_loop_count; }
1878 };
1879 
1880 static bool oop_offset_is_sane(const TypeInstPtr* tp) {
1881   ciInstanceKlass *k = tp->klass()->as_instance_klass();
1882   // Make sure the offset goes inside the instance layout.
1883   return k->contains_field_offset(tp->offset());
1884   // Note that OffsetBot and OffsetTop are very negative.
1885 }
1886 
1887 //------------------------------final_graph_reshaping_impl----------------------
1888 // Implement items 1-5 from final_graph_reshaping below.
1889 static void final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &frc ) {
1890 
1891   if ( n->outcnt() == 0 ) return; // dead node
1892   uint nop = n->Opcode();
1893 
1894   // Check for 2-input instruction with "last use" on right input.
1895   // Swap to left input.  Implements item (2).
1896   if( n->req() == 3 &&          // two-input instruction
1897       n->in(1)->outcnt() > 1 && // left use is NOT a last use
1898       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
1899       n->in(2)->outcnt() == 1 &&// right use IS a last use
1900       !n->in(2)->is_Con() ) {   // right use is not a constant
1901     // Check for commutative opcode
1902     switch( nop ) {
1903     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddL:
1904     case Op_MaxI:  case Op_MinI:
1905     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulL:
1906     case Op_AndL:  case Op_XorL:  case Op_OrL:
1907     case Op_AndI:  case Op_XorI:  case Op_OrI: {
1908       // Move "last use" input to left by swapping inputs
1909       n->swap_edges(1, 2);
1910       break;
1911     }
1912     default:
1913       break;
1914     }
1915   }
1916 
1917   // Count FPU ops and common calls, implements item (3)
1918   switch( nop ) {
1919   // Count all float operations that may use FPU
1920   case Op_AddF:
1921   case Op_SubF:
1922   case Op_MulF:
1923   case Op_DivF:
1924   case Op_NegF:
1925   case Op_ModF:
1926   case Op_ConvI2F:
1927   case Op_ConF:
1928   case Op_CmpF:
1929   case Op_CmpF3:
1930   // case Op_ConvL2F: // longs are split into 32-bit halves
1931     frc.inc_float_count();
1932     break;
1933 
1934   case Op_ConvF2D:
1935   case Op_ConvD2F:
1936     frc.inc_float_count();
1937     frc.inc_double_count();
1938     break;
1939 
1940   // Count all double operations that may use FPU
1941   case Op_AddD:
1942   case Op_SubD:
1943   case Op_MulD:
1944   case Op_DivD:
1945   case Op_NegD:
1946   case Op_ModD:
1947   case Op_ConvI2D:
1948   case Op_ConvD2I:
1949   // case Op_ConvL2D: // handled by leaf call
1950   // case Op_ConvD2L: // handled by leaf call
1951   case Op_ConD:
1952   case Op_CmpD:
1953   case Op_CmpD3:
1954     frc.inc_double_count();
1955     break;
1956   case Op_Opaque1:              // Remove Opaque Nodes before matching
1957   case Op_Opaque2:              // Remove Opaque Nodes before matching
1958     n->subsume_by(n->in(1));
1959     break;
1960   case Op_CallStaticJava:
1961   case Op_CallJava:
1962   case Op_CallDynamicJava:
1963     frc.inc_java_call_count(); // Count java call site;
1964   case Op_CallRuntime:
1965   case Op_CallLeaf:
1966   case Op_CallLeafNoFP: {
1967     assert( n->is_Call(), "" );
1968     CallNode *call = n->as_Call();
1969     // Count call sites where the FP mode bit would have to be flipped.
1970     // Do not count uncommon runtime calls:
1971     // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
1972     // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
1973     if( !call->is_CallStaticJava() || !call->as_CallStaticJava()->_name ) {
1974       frc.inc_call_count();   // Count the call site
1975     } else {                  // See if uncommon argument is shared
1976       Node *n = call->in(TypeFunc::Parms);
1977       int nop = n->Opcode();
1978       // Clone shared simple arguments to uncommon calls, item (1).
1979       if( n->outcnt() > 1 &&
1980           !n->is_Proj() &&
1981           nop != Op_CreateEx &&
1982           nop != Op_CheckCastPP &&
1983           nop != Op_DecodeN &&
1984           !n->is_Mem() ) {
1985         Node *x = n->clone();
1986         call->set_req( TypeFunc::Parms, x );
1987       }
1988     }
1989     break;
1990   }
1991 
1992   case Op_StoreD:
1993   case Op_LoadD:
1994   case Op_LoadD_unaligned:
1995     frc.inc_double_count();
1996     goto handle_mem;
1997   case Op_StoreF:
1998   case Op_LoadF:
1999     frc.inc_float_count();
2000     goto handle_mem;
2001 
2002   case Op_StoreB:
2003   case Op_StoreC:
2004   case Op_StoreCM:
2005   case Op_StorePConditional:
2006   case Op_StoreI:
2007   case Op_StoreL:
2008   case Op_StoreIConditional:
2009   case Op_StoreLConditional:
2010   case Op_CompareAndSwapI:
2011   case Op_CompareAndSwapL:
2012   case Op_CompareAndSwapP:
2013   case Op_CompareAndSwapN:
2014   case Op_StoreP:
2015   case Op_StoreN:
2016   case Op_LoadB:
2017   case Op_LoadUB:
2018   case Op_LoadUS:
2019   case Op_LoadI:
2020   case Op_LoadUI2L:
2021   case Op_LoadKlass:
2022   case Op_LoadNKlass:
2023   case Op_LoadL:
2024   case Op_LoadL_unaligned:
2025   case Op_LoadPLocked:
2026   case Op_LoadLLocked:
2027   case Op_LoadP:
2028   case Op_LoadN:
2029   case Op_LoadRange:
2030   case Op_LoadS: {
2031   handle_mem:
2032 #ifdef ASSERT
2033     if( VerifyOptoOopOffsets ) {
2034       assert( n->is_Mem(), "" );
2035       MemNode *mem  = (MemNode*)n;
2036       // Check to see if address types have grounded out somehow.
2037       const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
2038       assert( !tp || oop_offset_is_sane(tp), "" );
2039     }
2040 #endif
2041     break;
2042   }
2043 
2044   case Op_AddP: {               // Assert sane base pointers
2045     Node *addp = n->in(AddPNode::Address);
2046     assert( !addp->is_AddP() ||
2047             addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
2048             addp->in(AddPNode::Base) == n->in(AddPNode::Base),
2049             "Base pointers must match" );
2050 #ifdef _LP64
2051     if (UseCompressedOops &&
2052         addp->Opcode() == Op_ConP &&
2053         addp == n->in(AddPNode::Base) &&
2054         n->in(AddPNode::Offset)->is_Con()) {
2055       // Use addressing with narrow klass to load with offset on x86.
2056       // On sparc loading 32-bits constant and decoding it have less
2057       // instructions (4) then load 64-bits constant (7).
2058       // Do this transformation here since IGVN will convert ConN back to ConP.
2059       const Type* t = addp->bottom_type();
2060       if (t->isa_oopptr()) {
2061         Node* nn = NULL;
2062 
2063         // Look for existing ConN node of the same exact type.
2064         Compile* C = Compile::current();
2065         Node* r  = C->root();
2066         uint cnt = r->outcnt();
2067         for (uint i = 0; i < cnt; i++) {
2068           Node* m = r->raw_out(i);
2069           if (m!= NULL && m->Opcode() == Op_ConN &&
2070               m->bottom_type()->make_ptr() == t) {
2071             nn = m;
2072             break;
2073           }
2074         }
2075         if (nn != NULL) {
2076           // Decode a narrow oop to match address
2077           // [R12 + narrow_oop_reg<<3 + offset]
2078           nn = new (C,  2) DecodeNNode(nn, t);
2079           n->set_req(AddPNode::Base, nn);
2080           n->set_req(AddPNode::Address, nn);
2081           if (addp->outcnt() == 0) {
2082             addp->disconnect_inputs(NULL);
2083           }
2084         }
2085       }
2086     }
2087 #endif
2088     break;
2089   }
2090 
2091 #ifdef _LP64
2092   case Op_CastPP:
2093     if (n->in(1)->is_DecodeN() && Universe::narrow_oop_use_implicit_null_checks()) {
2094       Compile* C = Compile::current();
2095       Node* in1 = n->in(1);
2096       const Type* t = n->bottom_type();
2097       Node* new_in1 = in1->clone();
2098       new_in1->as_DecodeN()->set_type(t);
2099 
2100       if (!Matcher::clone_shift_expressions) {
2101         //
2102         // x86, ARM and friends can handle 2 adds in addressing mode
2103         // and Matcher can fold a DecodeN node into address by using
2104         // a narrow oop directly and do implicit NULL check in address:
2105         //
2106         // [R12 + narrow_oop_reg<<3 + offset]
2107         // NullCheck narrow_oop_reg
2108         //
2109         // On other platforms (Sparc) we have to keep new DecodeN node and
2110         // use it to do implicit NULL check in address:
2111         //
2112         // decode_not_null narrow_oop_reg, base_reg
2113         // [base_reg + offset]
2114         // NullCheck base_reg
2115         //
2116         // Pin the new DecodeN node to non-null path on these platform (Sparc)
2117         // to keep the information to which NULL check the new DecodeN node
2118         // corresponds to use it as value in implicit_null_check().
2119         //
2120         new_in1->set_req(0, n->in(0));
2121       }
2122 
2123       n->subsume_by(new_in1);
2124       if (in1->outcnt() == 0) {
2125         in1->disconnect_inputs(NULL);
2126       }
2127     }
2128     break;
2129 
2130   case Op_CmpP:
2131     // Do this transformation here to preserve CmpPNode::sub() and
2132     // other TypePtr related Ideal optimizations (for example, ptr nullness).
2133     if (n->in(1)->is_DecodeN() || n->in(2)->is_DecodeN()) {
2134       Node* in1 = n->in(1);
2135       Node* in2 = n->in(2);
2136       if (!in1->is_DecodeN()) {
2137         in2 = in1;
2138         in1 = n->in(2);
2139       }
2140       assert(in1->is_DecodeN(), "sanity");
2141 
2142       Compile* C = Compile::current();
2143       Node* new_in2 = NULL;
2144       if (in2->is_DecodeN()) {
2145         new_in2 = in2->in(1);
2146       } else if (in2->Opcode() == Op_ConP) {
2147         const Type* t = in2->bottom_type();
2148         if (t == TypePtr::NULL_PTR && Universe::narrow_oop_use_implicit_null_checks()) {
2149           new_in2 = ConNode::make(C, TypeNarrowOop::NULL_PTR);
2150           //
2151           // This transformation together with CastPP transformation above
2152           // will generated code for implicit NULL checks for compressed oops.
2153           //
2154           // The original code after Optimize()
2155           //
2156           //    LoadN memory, narrow_oop_reg
2157           //    decode narrow_oop_reg, base_reg
2158           //    CmpP base_reg, NULL
2159           //    CastPP base_reg // NotNull
2160           //    Load [base_reg + offset], val_reg
2161           //
2162           // after these transformations will be
2163           //
2164           //    LoadN memory, narrow_oop_reg
2165           //    CmpN narrow_oop_reg, NULL
2166           //    decode_not_null narrow_oop_reg, base_reg
2167           //    Load [base_reg + offset], val_reg
2168           //
2169           // and the uncommon path (== NULL) will use narrow_oop_reg directly
2170           // since narrow oops can be used in debug info now (see the code in
2171           // final_graph_reshaping_walk()).
2172           //
2173           // At the end the code will be matched to
2174           // on x86:
2175           //
2176           //    Load_narrow_oop memory, narrow_oop_reg
2177           //    Load [R12 + narrow_oop_reg<<3 + offset], val_reg
2178           //    NullCheck narrow_oop_reg
2179           //
2180           // and on sparc:
2181           //
2182           //    Load_narrow_oop memory, narrow_oop_reg
2183           //    decode_not_null narrow_oop_reg, base_reg
2184           //    Load [base_reg + offset], val_reg
2185           //    NullCheck base_reg
2186           //
2187         } else if (t->isa_oopptr()) {
2188           new_in2 = ConNode::make(C, t->make_narrowoop());
2189         }
2190       }
2191       if (new_in2 != NULL) {
2192         Node* cmpN = new (C, 3) CmpNNode(in1->in(1), new_in2);
2193         n->subsume_by( cmpN );
2194         if (in1->outcnt() == 0) {
2195           in1->disconnect_inputs(NULL);
2196         }
2197         if (in2->outcnt() == 0) {
2198           in2->disconnect_inputs(NULL);
2199         }
2200       }
2201     }
2202     break;
2203 
2204   case Op_DecodeN:
2205     assert(!n->in(1)->is_EncodeP(), "should be optimized out");
2206     // DecodeN could be pinned on Sparc where it can't be fold into
2207     // an address expression, see the code for Op_CastPP above.
2208     assert(n->in(0) == NULL || !Matcher::clone_shift_expressions, "no control except on sparc");
2209     break;
2210 
2211   case Op_EncodeP: {
2212     Node* in1 = n->in(1);
2213     if (in1->is_DecodeN()) {
2214       n->subsume_by(in1->in(1));
2215     } else if (in1->Opcode() == Op_ConP) {
2216       Compile* C = Compile::current();
2217       const Type* t = in1->bottom_type();
2218       if (t == TypePtr::NULL_PTR) {
2219         n->subsume_by(ConNode::make(C, TypeNarrowOop::NULL_PTR));
2220       } else if (t->isa_oopptr()) {
2221         n->subsume_by(ConNode::make(C, t->make_narrowoop()));
2222       }
2223     }
2224     if (in1->outcnt() == 0) {
2225       in1->disconnect_inputs(NULL);
2226     }
2227     break;
2228   }
2229 
2230   case Op_Phi:
2231     if (n->as_Phi()->bottom_type()->isa_narrowoop()) {
2232       // The EncodeP optimization may create Phi with the same edges
2233       // for all paths. It is not handled well by Register Allocator.
2234       Node* unique_in = n->in(1);
2235       assert(unique_in != NULL, "");
2236       uint cnt = n->req();
2237       for (uint i = 2; i < cnt; i++) {
2238         Node* m = n->in(i);
2239         assert(m != NULL, "");
2240         if (unique_in != m)
2241           unique_in = NULL;
2242       }
2243       if (unique_in != NULL) {
2244         n->subsume_by(unique_in);
2245       }
2246     }
2247     break;
2248 
2249 #endif
2250 
2251   case Op_ModI:
2252     if (UseDivMod) {
2253       // Check if a%b and a/b both exist
2254       Node* d = n->find_similar(Op_DivI);
2255       if (d) {
2256         // Replace them with a fused divmod if supported
2257         Compile* C = Compile::current();
2258         if (Matcher::has_match_rule(Op_DivModI)) {
2259           DivModINode* divmod = DivModINode::make(C, n);
2260           d->subsume_by(divmod->div_proj());
2261           n->subsume_by(divmod->mod_proj());
2262         } else {
2263           // replace a%b with a-((a/b)*b)
2264           Node* mult = new (C, 3) MulINode(d, d->in(2));
2265           Node* sub  = new (C, 3) SubINode(d->in(1), mult);
2266           n->subsume_by( sub );
2267         }
2268       }
2269     }
2270     break;
2271 
2272   case Op_ModL:
2273     if (UseDivMod) {
2274       // Check if a%b and a/b both exist
2275       Node* d = n->find_similar(Op_DivL);
2276       if (d) {
2277         // Replace them with a fused divmod if supported
2278         Compile* C = Compile::current();
2279         if (Matcher::has_match_rule(Op_DivModL)) {
2280           DivModLNode* divmod = DivModLNode::make(C, n);
2281           d->subsume_by(divmod->div_proj());
2282           n->subsume_by(divmod->mod_proj());
2283         } else {
2284           // replace a%b with a-((a/b)*b)
2285           Node* mult = new (C, 3) MulLNode(d, d->in(2));
2286           Node* sub  = new (C, 3) SubLNode(d->in(1), mult);
2287           n->subsume_by( sub );
2288         }
2289       }
2290     }
2291     break;
2292 
2293   case Op_Load16B:
2294   case Op_Load8B:
2295   case Op_Load4B:
2296   case Op_Load8S:
2297   case Op_Load4S:
2298   case Op_Load2S:
2299   case Op_Load8C:
2300   case Op_Load4C:
2301   case Op_Load2C:
2302   case Op_Load4I:
2303   case Op_Load2I:
2304   case Op_Load2L:
2305   case Op_Load4F:
2306   case Op_Load2F:
2307   case Op_Load2D:
2308   case Op_Store16B:
2309   case Op_Store8B:
2310   case Op_Store4B:
2311   case Op_Store8C:
2312   case Op_Store4C:
2313   case Op_Store2C:
2314   case Op_Store4I:
2315   case Op_Store2I:
2316   case Op_Store2L:
2317   case Op_Store4F:
2318   case Op_Store2F:
2319   case Op_Store2D:
2320     break;
2321 
2322   case Op_PackB:
2323   case Op_PackS:
2324   case Op_PackC:
2325   case Op_PackI:
2326   case Op_PackF:
2327   case Op_PackL:
2328   case Op_PackD:
2329     if (n->req()-1 > 2) {
2330       // Replace many operand PackNodes with a binary tree for matching
2331       PackNode* p = (PackNode*) n;
2332       Node* btp = p->binaryTreePack(Compile::current(), 1, n->req());
2333       n->subsume_by(btp);
2334     }
2335     break;
2336   case Op_Loop:
2337   case Op_CountedLoop:
2338     if (n->as_Loop()->is_inner_loop()) {
2339       frc.inc_inner_loop_count();
2340     }
2341     break;
2342   default:
2343     assert( !n->is_Call(), "" );
2344     assert( !n->is_Mem(), "" );
2345     break;
2346   }
2347 
2348   // Collect CFG split points
2349   if (n->is_MultiBranch())
2350     frc._tests.push(n);
2351 }
2352 
2353 //------------------------------final_graph_reshaping_walk---------------------
2354 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
2355 // requires that the walk visits a node's inputs before visiting the node.
2356 static void final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Reshape_Counts &frc ) {
2357   ResourceArea *area = Thread::current()->resource_area();
2358   Unique_Node_List sfpt(area);
2359 
2360   frc._visited.set(root->_idx); // first, mark node as visited
2361   uint cnt = root->req();
2362   Node *n = root;
2363   uint  i = 0;
2364   while (true) {
2365     if (i < cnt) {
2366       // Place all non-visited non-null inputs onto stack
2367       Node* m = n->in(i);
2368       ++i;
2369       if (m != NULL && !frc._visited.test_set(m->_idx)) {
2370         if (m->is_SafePoint() && m->as_SafePoint()->jvms() != NULL)
2371           sfpt.push(m);
2372         cnt = m->req();
2373         nstack.push(n, i); // put on stack parent and next input's index
2374         n = m;
2375         i = 0;
2376       }
2377     } else {
2378       // Now do post-visit work
2379       final_graph_reshaping_impl( n, frc );
2380       if (nstack.is_empty())
2381         break;             // finished
2382       n = nstack.node();   // Get node from stack
2383       cnt = n->req();
2384       i = nstack.index();
2385       nstack.pop();        // Shift to the next node on stack
2386     }
2387   }
2388 
2389   // Go over safepoints nodes to skip DecodeN nodes for debug edges.
2390   // It could be done for an uncommon traps or any safepoints/calls
2391   // if the DecodeN node is referenced only in a debug info.
2392   while (sfpt.size() > 0) {
2393     n = sfpt.pop();
2394     JVMState *jvms = n->as_SafePoint()->jvms();
2395     assert(jvms != NULL, "sanity");
2396     int start = jvms->debug_start();
2397     int end   = n->req();
2398     bool is_uncommon = (n->is_CallStaticJava() &&
2399                         n->as_CallStaticJava()->uncommon_trap_request() != 0);
2400     for (int j = start; j < end; j++) {
2401       Node* in = n->in(j);
2402       if (in->is_DecodeN()) {
2403         bool safe_to_skip = true;
2404         if (!is_uncommon ) {
2405           // Is it safe to skip?
2406           for (uint i = 0; i < in->outcnt(); i++) {
2407             Node* u = in->raw_out(i);
2408             if (!u->is_SafePoint() ||
2409                  u->is_Call() && u->as_Call()->has_non_debug_use(n)) {
2410               safe_to_skip = false;
2411             }
2412           }
2413         }
2414         if (safe_to_skip) {
2415           n->set_req(j, in->in(1));
2416         }
2417         if (in->outcnt() == 0) {
2418           in->disconnect_inputs(NULL);
2419         }
2420       }
2421     }
2422   }
2423 }
2424 
2425 //------------------------------final_graph_reshaping--------------------------
2426 // Final Graph Reshaping.
2427 //
2428 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
2429 //     and not commoned up and forced early.  Must come after regular
2430 //     optimizations to avoid GVN undoing the cloning.  Clone constant
2431 //     inputs to Loop Phis; these will be split by the allocator anyways.
2432 //     Remove Opaque nodes.
2433 // (2) Move last-uses by commutative operations to the left input to encourage
2434 //     Intel update-in-place two-address operations and better register usage
2435 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
2436 //     calls canonicalizing them back.
2437 // (3) Count the number of double-precision FP ops, single-precision FP ops
2438 //     and call sites.  On Intel, we can get correct rounding either by
2439 //     forcing singles to memory (requires extra stores and loads after each
2440 //     FP bytecode) or we can set a rounding mode bit (requires setting and
2441 //     clearing the mode bit around call sites).  The mode bit is only used
2442 //     if the relative frequency of single FP ops to calls is low enough.
2443 //     This is a key transform for SPEC mpeg_audio.
2444 // (4) Detect infinite loops; blobs of code reachable from above but not
2445 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
2446 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
2447 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
2448 //     Detection is by looking for IfNodes where only 1 projection is
2449 //     reachable from below or CatchNodes missing some targets.
2450 // (5) Assert for insane oop offsets in debug mode.
2451 
2452 bool Compile::final_graph_reshaping() {
2453   // an infinite loop may have been eliminated by the optimizer,
2454   // in which case the graph will be empty.
2455   if (root()->req() == 1) {
2456     record_method_not_compilable("trivial infinite loop");
2457     return true;
2458   }
2459 
2460   Final_Reshape_Counts frc;
2461 
2462   // Visit everybody reachable!
2463   // Allocate stack of size C->unique()/2 to avoid frequent realloc
2464   Node_Stack nstack(unique() >> 1);
2465   final_graph_reshaping_walk(nstack, root(), frc);
2466 
2467   // Check for unreachable (from below) code (i.e., infinite loops).
2468   for( uint i = 0; i < frc._tests.size(); i++ ) {
2469     MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
2470     // Get number of CFG targets.
2471     // Note that PCTables include exception targets after calls.
2472     uint required_outcnt = n->required_outcnt();
2473     if (n->outcnt() != required_outcnt) {
2474       // Check for a few special cases.  Rethrow Nodes never take the
2475       // 'fall-thru' path, so expected kids is 1 less.
2476       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
2477         if (n->in(0)->in(0)->is_Call()) {
2478           CallNode *call = n->in(0)->in(0)->as_Call();
2479           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
2480             required_outcnt--;      // Rethrow always has 1 less kid
2481           } else if (call->req() > TypeFunc::Parms &&
2482                      call->is_CallDynamicJava()) {
2483             // Check for null receiver. In such case, the optimizer has
2484             // detected that the virtual call will always result in a null
2485             // pointer exception. The fall-through projection of this CatchNode
2486             // will not be populated.
2487             Node *arg0 = call->in(TypeFunc::Parms);
2488             if (arg0->is_Type() &&
2489                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
2490               required_outcnt--;
2491             }
2492           } else if (call->entry_point() == OptoRuntime::new_array_Java() &&
2493                      call->req() > TypeFunc::Parms+1 &&
2494                      call->is_CallStaticJava()) {
2495             // Check for negative array length. In such case, the optimizer has
2496             // detected that the allocation attempt will always result in an
2497             // exception. There is no fall-through projection of this CatchNode .
2498             Node *arg1 = call->in(TypeFunc::Parms+1);
2499             if (arg1->is_Type() &&
2500                 arg1->as_Type()->type()->join(TypeInt::POS)->empty()) {
2501               required_outcnt--;
2502             }
2503           }
2504         }
2505       }
2506       // Recheck with a better notion of 'required_outcnt'
2507       if (n->outcnt() != required_outcnt) {
2508         record_method_not_compilable("malformed control flow");
2509         return true;            // Not all targets reachable!
2510       }
2511     }
2512     // Check that I actually visited all kids.  Unreached kids
2513     // must be infinite loops.
2514     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
2515       if (!frc._visited.test(n->fast_out(j)->_idx)) {
2516         record_method_not_compilable("infinite loop");
2517         return true;            // Found unvisited kid; must be unreach
2518       }
2519   }
2520 
2521   // If original bytecodes contained a mixture of floats and doubles
2522   // check if the optimizer has made it homogenous, item (3).
2523   if( Use24BitFPMode && Use24BitFP &&
2524       frc.get_float_count() > 32 &&
2525       frc.get_double_count() == 0 &&
2526       (10 * frc.get_call_count() < frc.get_float_count()) ) {
2527     set_24_bit_selection_and_mode( false,  true );
2528   }
2529 
2530   set_java_calls(frc.get_java_call_count());
2531   set_inner_loops(frc.get_inner_loop_count());
2532 
2533   // No infinite loops, no reason to bail out.
2534   return false;
2535 }
2536 
2537 //-----------------------------too_many_traps----------------------------------
2538 // Report if there are too many traps at the current method and bci.
2539 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
2540 bool Compile::too_many_traps(ciMethod* method,
2541                              int bci,
2542                              Deoptimization::DeoptReason reason) {
2543   ciMethodData* md = method->method_data();
2544   if (md->is_empty()) {
2545     // Assume the trap has not occurred, or that it occurred only
2546     // because of a transient condition during start-up in the interpreter.
2547     return false;
2548   }
2549   if (md->has_trap_at(bci, reason) != 0) {
2550     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
2551     // Also, if there are multiple reasons, or if there is no per-BCI record,
2552     // assume the worst.
2553     if (log())
2554       log()->elem("observe trap='%s' count='%d'",
2555                   Deoptimization::trap_reason_name(reason),
2556                   md->trap_count(reason));
2557     return true;
2558   } else {
2559     // Ignore method/bci and see if there have been too many globally.
2560     return too_many_traps(reason, md);
2561   }
2562 }
2563 
2564 // Less-accurate variant which does not require a method and bci.
2565 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
2566                              ciMethodData* logmd) {
2567  if (trap_count(reason) >= (uint)PerMethodTrapLimit) {
2568     // Too many traps globally.
2569     // Note that we use cumulative trap_count, not just md->trap_count.
2570     if (log()) {
2571       int mcount = (logmd == NULL)? -1: (int)logmd->trap_count(reason);
2572       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
2573                   Deoptimization::trap_reason_name(reason),
2574                   mcount, trap_count(reason));
2575     }
2576     return true;
2577   } else {
2578     // The coast is clear.
2579     return false;
2580   }
2581 }
2582 
2583 //--------------------------too_many_recompiles--------------------------------
2584 // Report if there are too many recompiles at the current method and bci.
2585 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
2586 // Is not eager to return true, since this will cause the compiler to use
2587 // Action_none for a trap point, to avoid too many recompilations.
2588 bool Compile::too_many_recompiles(ciMethod* method,
2589                                   int bci,
2590                                   Deoptimization::DeoptReason reason) {
2591   ciMethodData* md = method->method_data();
2592   if (md->is_empty()) {
2593     // Assume the trap has not occurred, or that it occurred only
2594     // because of a transient condition during start-up in the interpreter.
2595     return false;
2596   }
2597   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
2598   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
2599   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
2600   Deoptimization::DeoptReason per_bc_reason
2601     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
2602   if ((per_bc_reason == Deoptimization::Reason_none
2603        || md->has_trap_at(bci, reason) != 0)
2604       // The trap frequency measure we care about is the recompile count:
2605       && md->trap_recompiled_at(bci)
2606       && md->overflow_recompile_count() >= bc_cutoff) {
2607     // Do not emit a trap here if it has already caused recompilations.
2608     // Also, if there are multiple reasons, or if there is no per-BCI record,
2609     // assume the worst.
2610     if (log())
2611       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
2612                   Deoptimization::trap_reason_name(reason),
2613                   md->trap_count(reason),
2614                   md->overflow_recompile_count());
2615     return true;
2616   } else if (trap_count(reason) != 0
2617              && decompile_count() >= m_cutoff) {
2618     // Too many recompiles globally, and we have seen this sort of trap.
2619     // Use cumulative decompile_count, not just md->decompile_count.
2620     if (log())
2621       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
2622                   Deoptimization::trap_reason_name(reason),
2623                   md->trap_count(reason), trap_count(reason),
2624                   md->decompile_count(), decompile_count());
2625     return true;
2626   } else {
2627     // The coast is clear.
2628     return false;
2629   }
2630 }
2631 
2632 
2633 #ifndef PRODUCT
2634 //------------------------------verify_graph_edges---------------------------
2635 // Walk the Graph and verify that there is a one-to-one correspondence
2636 // between Use-Def edges and Def-Use edges in the graph.
2637 void Compile::verify_graph_edges(bool no_dead_code) {
2638   if (VerifyGraphEdges) {
2639     ResourceArea *area = Thread::current()->resource_area();
2640     Unique_Node_List visited(area);
2641     // Call recursive graph walk to check edges
2642     _root->verify_edges(visited);
2643     if (no_dead_code) {
2644       // Now make sure that no visited node is used by an unvisited node.
2645       bool dead_nodes = 0;
2646       Unique_Node_List checked(area);
2647       while (visited.size() > 0) {
2648         Node* n = visited.pop();
2649         checked.push(n);
2650         for (uint i = 0; i < n->outcnt(); i++) {
2651           Node* use = n->raw_out(i);
2652           if (checked.member(use))  continue;  // already checked
2653           if (visited.member(use))  continue;  // already in the graph
2654           if (use->is_Con())        continue;  // a dead ConNode is OK
2655           // At this point, we have found a dead node which is DU-reachable.
2656           if (dead_nodes++ == 0)
2657             tty->print_cr("*** Dead nodes reachable via DU edges:");
2658           use->dump(2);
2659           tty->print_cr("---");
2660           checked.push(use);  // No repeats; pretend it is now checked.
2661         }
2662       }
2663       assert(dead_nodes == 0, "using nodes must be reachable from root");
2664     }
2665   }
2666 }
2667 #endif
2668 
2669 // The Compile object keeps track of failure reasons separately from the ciEnv.
2670 // This is required because there is not quite a 1-1 relation between the
2671 // ciEnv and its compilation task and the Compile object.  Note that one
2672 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
2673 // to backtrack and retry without subsuming loads.  Other than this backtracking
2674 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
2675 // by the logic in C2Compiler.
2676 void Compile::record_failure(const char* reason) {
2677   if (log() != NULL) {
2678     log()->elem("failure reason='%s' phase='compile'", reason);
2679   }
2680   if (_failure_reason == NULL) {
2681     // Record the first failure reason.
2682     _failure_reason = reason;
2683   }
2684   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
2685     C->print_method(_failure_reason);
2686   }
2687   _root = NULL;  // flush the graph, too
2688 }
2689 
2690 Compile::TracePhase::TracePhase(const char* name, elapsedTimer* accumulator, bool dolog)
2691   : TraceTime(NULL, accumulator, false NOT_PRODUCT( || TimeCompiler ), false)
2692 {
2693   if (dolog) {
2694     C = Compile::current();
2695     _log = C->log();
2696   } else {
2697     C = NULL;
2698     _log = NULL;
2699   }
2700   if (_log != NULL) {
2701     _log->begin_head("phase name='%s' nodes='%d'", name, C->unique());
2702     _log->stamp();
2703     _log->end_head();
2704   }
2705 }
2706 
2707 Compile::TracePhase::~TracePhase() {
2708   if (_log != NULL) {
2709     _log->done("phase nodes='%d'", C->unique());
2710   }
2711 }