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 void Compile::gvn_replace_by(Node* n, Node* nn) {
 228   for (DUIterator_Last imin, i = n->last_outs(imin); i >= imin; ) {
 229     Node* use = n->last_out(i);
 230     bool is_in_table = initial_gvn()->hash_delete(use);
 231     uint uses_found = 0;
 232     for (uint j = 0; j < use->len(); j++) {
 233       if (use->in(j) == n) {
 234         if (j < use->req())
 235           use->set_req(j, nn);
 236         else
 237           use->set_prec(j, nn);
 238         uses_found++;
 239       }
 240     }
 241     if (is_in_table) {
 242       // reinsert into table
 243       initial_gvn()->hash_find_insert(use);
 244     }
 245     record_for_igvn(use);
 246     i -= uses_found;    // we deleted 1 or more copies of this edge
 247   }
 248 }
 249 
 250 
 251 
 252 
 253 // Identify all nodes that are reachable from below, useful.
 254 // Use breadth-first pass that records state in a Unique_Node_List,
 255 // recursive traversal is slower.
 256 void Compile::identify_useful_nodes(Unique_Node_List &useful) {
 257   int estimated_worklist_size = unique();
 258   useful.map( estimated_worklist_size, NULL );  // preallocate space
 259 
 260   // Initialize worklist
 261   if (root() != NULL)     { useful.push(root()); }
 262   // If 'top' is cached, declare it useful to preserve cached node
 263   if( cached_top_node() ) { useful.push(cached_top_node()); }
 264 
 265   // Push all useful nodes onto the list, breadthfirst
 266   for( uint next = 0; next < useful.size(); ++next ) {
 267     assert( next < unique(), "Unique useful nodes < total nodes");
 268     Node *n  = useful.at(next);
 269     uint max = n->len();
 270     for( uint i = 0; i < max; ++i ) {
 271       Node *m = n->in(i);
 272       if( m == NULL ) continue;
 273       useful.push(m);
 274     }
 275   }
 276 }
 277 
 278 // Disconnect all useless nodes by disconnecting those at the boundary.
 279 void Compile::remove_useless_nodes(Unique_Node_List &useful) {
 280   uint next = 0;
 281   while( next < useful.size() ) {
 282     Node *n = useful.at(next++);
 283     // Use raw traversal of out edges since this code removes out edges
 284     int max = n->outcnt();
 285     for (int j = 0; j < max; ++j ) {
 286       Node* child = n->raw_out(j);
 287       if( ! useful.member(child) ) {
 288         assert( !child->is_top() || child != top(),
 289                 "If top is cached in Compile object it is in useful list");
 290         // Only need to remove this out-edge to the useless node
 291         n->raw_del_out(j);
 292         --j;
 293         --max;
 294       }
 295     }
 296     if (n->outcnt() == 1 && n->has_special_unique_user()) {
 297       record_for_igvn( n->unique_out() );
 298     }
 299   }
 300   debug_only(verify_graph_edges(true/*check for no_dead_code*/);)
 301 }
 302 
 303 //------------------------------frame_size_in_words-----------------------------
 304 // frame_slots in units of words
 305 int Compile::frame_size_in_words() const {
 306   // shift is 0 in LP32 and 1 in LP64
 307   const int shift = (LogBytesPerWord - LogBytesPerInt);
 308   int words = _frame_slots >> shift;
 309   assert( words << shift == _frame_slots, "frame size must be properly aligned in LP64" );
 310   return words;
 311 }
 312 
 313 // ============================================================================
 314 //------------------------------CompileWrapper---------------------------------
 315 class CompileWrapper : public StackObj {
 316   Compile *const _compile;
 317  public:
 318   CompileWrapper(Compile* compile);
 319 
 320   ~CompileWrapper();
 321 };
 322 
 323 CompileWrapper::CompileWrapper(Compile* compile) : _compile(compile) {
 324   // the Compile* pointer is stored in the current ciEnv:
 325   ciEnv* env = compile->env();
 326   assert(env == ciEnv::current(), "must already be a ciEnv active");
 327   assert(env->compiler_data() == NULL, "compile already active?");
 328   env->set_compiler_data(compile);
 329   assert(compile == Compile::current(), "sanity");
 330 
 331   compile->set_type_dict(NULL);
 332   compile->set_type_hwm(NULL);
 333   compile->set_type_last_size(0);
 334   compile->set_last_tf(NULL, NULL);
 335   compile->set_indexSet_arena(NULL);
 336   compile->set_indexSet_free_block_list(NULL);
 337   compile->init_type_arena();
 338   Type::Initialize(compile);
 339   _compile->set_scratch_buffer_blob(NULL);
 340   _compile->begin_method();
 341 }
 342 CompileWrapper::~CompileWrapper() {
 343   _compile->end_method();
 344   if (_compile->scratch_buffer_blob() != NULL)
 345     BufferBlob::free(_compile->scratch_buffer_blob());
 346   _compile->env()->set_compiler_data(NULL);
 347 }
 348 
 349 
 350 //----------------------------print_compile_messages---------------------------
 351 void Compile::print_compile_messages() {
 352 #ifndef PRODUCT
 353   // Check if recompiling
 354   if (_subsume_loads == false && PrintOpto) {
 355     // Recompiling without allowing machine instructions to subsume loads
 356     tty->print_cr("*********************************************************");
 357     tty->print_cr("** Bailout: Recompile without subsuming loads          **");
 358     tty->print_cr("*********************************************************");
 359   }
 360   if (_do_escape_analysis != DoEscapeAnalysis && PrintOpto) {
 361     // Recompiling without escape analysis
 362     tty->print_cr("*********************************************************");
 363     tty->print_cr("** Bailout: Recompile without escape analysis          **");
 364     tty->print_cr("*********************************************************");
 365   }
 366   if (env()->break_at_compile()) {
 367     // Open the debugger when compiling this method.
 368     tty->print("### Breaking when compiling: ");
 369     method()->print_short_name();
 370     tty->cr();
 371     BREAKPOINT;
 372   }
 373 
 374   if( PrintOpto ) {
 375     if (is_osr_compilation()) {
 376       tty->print("[OSR]%3d", _compile_id);
 377     } else {
 378       tty->print("%3d", _compile_id);
 379     }
 380   }
 381 #endif
 382 }
 383 
 384 
 385 void Compile::init_scratch_buffer_blob() {
 386   if( scratch_buffer_blob() != NULL )  return;
 387 
 388   // Construct a temporary CodeBuffer to have it construct a BufferBlob
 389   // Cache this BufferBlob for this compile.
 390   ResourceMark rm;
 391   int size = (MAX_inst_size + MAX_stubs_size + MAX_const_size);
 392   BufferBlob* blob = BufferBlob::create("Compile::scratch_buffer", size);
 393   // Record the buffer blob for next time.
 394   set_scratch_buffer_blob(blob);
 395   // Have we run out of code space?
 396   if (scratch_buffer_blob() == NULL) {
 397     // Let CompilerBroker disable further compilations.
 398     record_failure("Not enough space for scratch buffer in CodeCache");
 399     return;
 400   }
 401 
 402   // Initialize the relocation buffers
 403   relocInfo* locs_buf = (relocInfo*) blob->instructions_end() - MAX_locs_size;
 404   set_scratch_locs_memory(locs_buf);
 405 }
 406 
 407 
 408 //-----------------------scratch_emit_size-------------------------------------
 409 // Helper function that computes size by emitting code
 410 uint Compile::scratch_emit_size(const Node* n) {
 411   // Emit into a trash buffer and count bytes emitted.
 412   // This is a pretty expensive way to compute a size,
 413   // but it works well enough if seldom used.
 414   // All common fixed-size instructions are given a size
 415   // method by the AD file.
 416   // Note that the scratch buffer blob and locs memory are
 417   // allocated at the beginning of the compile task, and
 418   // may be shared by several calls to scratch_emit_size.
 419   // The allocation of the scratch buffer blob is particularly
 420   // expensive, since it has to grab the code cache lock.
 421   BufferBlob* blob = this->scratch_buffer_blob();
 422   assert(blob != NULL, "Initialize BufferBlob at start");
 423   assert(blob->size() > MAX_inst_size, "sanity");
 424   relocInfo* locs_buf = scratch_locs_memory();
 425   address blob_begin = blob->instructions_begin();
 426   address blob_end   = (address)locs_buf;
 427   assert(blob->instructions_contains(blob_end), "sanity");
 428   CodeBuffer buf(blob_begin, blob_end - blob_begin);
 429   buf.initialize_consts_size(MAX_const_size);
 430   buf.initialize_stubs_size(MAX_stubs_size);
 431   assert(locs_buf != NULL, "sanity");
 432   int lsize = MAX_locs_size / 2;
 433   buf.insts()->initialize_shared_locs(&locs_buf[0],     lsize);
 434   buf.stubs()->initialize_shared_locs(&locs_buf[lsize], lsize);
 435   n->emit(buf, this->regalloc());
 436   return buf.code_size();
 437 }
 438 
 439 
 440 // ============================================================================
 441 //------------------------------Compile standard-------------------------------
 442 debug_only( int Compile::_debug_idx = 100000; )
 443 
 444 // Compile a method.  entry_bci is -1 for normal compilations and indicates
 445 // the continuation bci for on stack replacement.
 446 
 447 
 448 Compile::Compile( ciEnv* ci_env, C2Compiler* compiler, ciMethod* target, int osr_bci, bool subsume_loads, bool do_escape_analysis )
 449                 : Phase(Compiler),
 450                   _env(ci_env),
 451                   _log(ci_env->log()),
 452                   _compile_id(ci_env->compile_id()),
 453                   _save_argument_registers(false),
 454                   _stub_name(NULL),
 455                   _stub_function(NULL),
 456                   _stub_entry_point(NULL),
 457                   _method(target),
 458                   _entry_bci(osr_bci),
 459                   _initial_gvn(NULL),
 460                   _for_igvn(NULL),
 461                   _warm_calls(NULL),
 462                   _subsume_loads(subsume_loads),
 463                   _do_escape_analysis(do_escape_analysis),
 464                   _failure_reason(NULL),
 465                   _code_buffer("Compile::Fill_buffer"),
 466                   _orig_pc_slot(0),
 467                   _orig_pc_slot_offset_in_bytes(0),
 468                   _node_bundling_limit(0),
 469                   _node_bundling_base(NULL),
 470                   _java_calls(0),
 471                   _inner_loops(0),
 472 #ifndef PRODUCT
 473                   _trace_opto_output(TraceOptoOutput || method()->has_option("TraceOptoOutput")),
 474                   _printer(IdealGraphPrinter::printer()),
 475 #endif
 476                   _congraph(NULL) {
 477   C = this;
 478 
 479   CompileWrapper cw(this);
 480 #ifndef PRODUCT
 481   if (TimeCompiler2) {
 482     tty->print(" ");
 483     target->holder()->name()->print();
 484     tty->print(".");
 485     target->print_short_name();
 486     tty->print("  ");
 487   }
 488   TraceTime t1("Total compilation time", &_t_totalCompilation, TimeCompiler, TimeCompiler2);
 489   TraceTime t2(NULL, &_t_methodCompilation, TimeCompiler, false);
 490   bool print_opto_assembly = PrintOptoAssembly || _method->has_option("PrintOptoAssembly");
 491   if (!print_opto_assembly) {
 492     bool print_assembly = (PrintAssembly || _method->should_print_assembly());
 493     if (print_assembly && !Disassembler::can_decode()) {
 494       tty->print_cr("PrintAssembly request changed to PrintOptoAssembly");
 495       print_opto_assembly = true;
 496     }
 497   }
 498   set_print_assembly(print_opto_assembly);
 499   set_parsed_irreducible_loop(false);
 500 #endif
 501 
 502   if (ProfileTraps) {
 503     // Make sure the method being compiled gets its own MDO,
 504     // so we can at least track the decompile_count().
 505     method()->build_method_data();
 506   }
 507 
 508   Init(::AliasLevel);
 509 
 510 
 511   print_compile_messages();
 512 
 513   if (UseOldInlining || PrintCompilation NOT_PRODUCT( || PrintOpto) )
 514     _ilt = InlineTree::build_inline_tree_root();
 515   else
 516     _ilt = NULL;
 517 
 518   // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
 519   assert(num_alias_types() >= AliasIdxRaw, "");
 520 
 521 #define MINIMUM_NODE_HASH  1023
 522   // Node list that Iterative GVN will start with
 523   Unique_Node_List for_igvn(comp_arena());
 524   set_for_igvn(&for_igvn);
 525 
 526   // GVN that will be run immediately on new nodes
 527   uint estimated_size = method()->code_size()*4+64;
 528   estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
 529   PhaseGVN gvn(node_arena(), estimated_size);
 530   set_initial_gvn(&gvn);
 531 
 532   { // Scope for timing the parser
 533     TracePhase t3("parse", &_t_parser, true);
 534 
 535     // Put top into the hash table ASAP.
 536     initial_gvn()->transform_no_reclaim(top());
 537 
 538     // Set up tf(), start(), and find a CallGenerator.
 539     CallGenerator* cg;
 540     if (is_osr_compilation()) {
 541       const TypeTuple *domain = StartOSRNode::osr_domain();
 542       const TypeTuple *range = TypeTuple::make_range(method()->signature());
 543       init_tf(TypeFunc::make(domain, range));
 544       StartNode* s = new (this, 2) StartOSRNode(root(), domain);
 545       initial_gvn()->set_type_bottom(s);
 546       init_start(s);
 547       cg = CallGenerator::for_osr(method(), entry_bci());
 548     } else {
 549       // Normal case.
 550       init_tf(TypeFunc::make(method()));
 551       StartNode* s = new (this, 2) StartNode(root(), tf()->domain());
 552       initial_gvn()->set_type_bottom(s);
 553       init_start(s);
 554       float past_uses = method()->interpreter_invocation_count();
 555       float expected_uses = past_uses;
 556       cg = CallGenerator::for_inline(method(), expected_uses);
 557     }
 558     if (failing())  return;
 559     if (cg == NULL) {
 560       record_method_not_compilable_all_tiers("cannot parse method");
 561       return;
 562     }
 563     JVMState* jvms = build_start_state(start(), tf());
 564     if ((jvms = cg->generate(jvms)) == NULL) {
 565       record_method_not_compilable("method parse failed");
 566       return;
 567     }
 568     GraphKit kit(jvms);
 569 
 570     if (!kit.stopped()) {
 571       // Accept return values, and transfer control we know not where.
 572       // This is done by a special, unique ReturnNode bound to root.
 573       return_values(kit.jvms());
 574     }
 575 
 576     if (kit.has_exceptions()) {
 577       // Any exceptions that escape from this call must be rethrown
 578       // to whatever caller is dynamically above us on the stack.
 579       // This is done by a special, unique RethrowNode bound to root.
 580       rethrow_exceptions(kit.transfer_exceptions_into_jvms());
 581     }
 582 
 583     if (!failing() && has_stringbuilder()) {
 584       {
 585         // remove useless nodes to make the usage analysis simpler
 586         ResourceMark rm;
 587         PhaseRemoveUseless pru(initial_gvn(), &for_igvn);
 588       }
 589 
 590       {
 591         ResourceMark rm;
 592         print_method("Before StringOpts", 3);
 593         PhaseStringOpts pso(initial_gvn(), &for_igvn);
 594         print_method("After StringOpts", 3);
 595       }
 596 
 597       // now inline anything that we skipped the first time around
 598       while (_late_inlines.length() > 0) {
 599         CallGenerator* cg = _late_inlines.pop();
 600         cg->do_late_inline();
 601       }
 602     }
 603     assert(_late_inlines.length() == 0, "should have been processed");
 604 
 605     print_method("Before RemoveUseless", 3);
 606 
 607     // Remove clutter produced by parsing.
 608     if (!failing()) {
 609       ResourceMark rm;
 610       PhaseRemoveUseless pru(initial_gvn(), &for_igvn);
 611     }
 612   }
 613 
 614   // Note:  Large methods are capped off in do_one_bytecode().
 615   if (failing())  return;
 616 
 617   // After parsing, node notes are no longer automagic.
 618   // They must be propagated by register_new_node_with_optimizer(),
 619   // clone(), or the like.
 620   set_default_node_notes(NULL);
 621 
 622   for (;;) {
 623     int successes = Inline_Warm();
 624     if (failing())  return;
 625     if (successes == 0)  break;
 626   }
 627 
 628   // Drain the list.
 629   Finish_Warm();
 630 #ifndef PRODUCT
 631   if (_printer) {
 632     _printer->print_inlining(this);
 633   }
 634 #endif
 635 
 636   if (failing())  return;
 637   NOT_PRODUCT( verify_graph_edges(); )
 638 
 639   // Perform escape analysis
 640   if (_do_escape_analysis && ConnectionGraph::has_candidates(this)) {
 641     TracePhase t2("escapeAnalysis", &_t_escapeAnalysis, true);
 642     // Add ConP#NULL and ConN#NULL nodes before ConnectionGraph construction.
 643     PhaseGVN* igvn = initial_gvn();
 644     Node* oop_null = igvn->zerocon(T_OBJECT);
 645     Node* noop_null = igvn->zerocon(T_NARROWOOP);
 646 
 647     _congraph = new(comp_arena()) ConnectionGraph(this);
 648     bool has_non_escaping_obj = _congraph->compute_escape();
 649 
 650 #ifndef PRODUCT
 651     if (PrintEscapeAnalysis) {
 652       _congraph->dump();
 653     }
 654 #endif
 655     // Cleanup.
 656     if (oop_null->outcnt() == 0)
 657       igvn->hash_delete(oop_null);
 658     if (noop_null->outcnt() == 0)
 659       igvn->hash_delete(noop_null);
 660 
 661     if (!has_non_escaping_obj) {
 662       _congraph = NULL;
 663     }
 664 
 665     if (failing())  return;
 666   }
 667   // Now optimize
 668   Optimize();
 669   if (failing())  return;
 670   NOT_PRODUCT( verify_graph_edges(); )
 671 
 672 #ifndef PRODUCT
 673   if (PrintIdeal) {
 674     ttyLocker ttyl;  // keep the following output all in one block
 675     // This output goes directly to the tty, not the compiler log.
 676     // To enable tools to match it up with the compilation activity,
 677     // be sure to tag this tty output with the compile ID.
 678     if (xtty != NULL) {
 679       xtty->head("ideal compile_id='%d'%s", compile_id(),
 680                  is_osr_compilation()    ? " compile_kind='osr'" :
 681                  "");
 682     }
 683     root()->dump(9999);
 684     if (xtty != NULL) {
 685       xtty->tail("ideal");
 686     }
 687   }
 688 #endif
 689 
 690   // Now that we know the size of all the monitors we can add a fixed slot
 691   // for the original deopt pc.
 692 
 693   _orig_pc_slot =  fixed_slots();
 694   int next_slot = _orig_pc_slot + (sizeof(address) / VMRegImpl::stack_slot_size);
 695   set_fixed_slots(next_slot);
 696 
 697   // Now generate code
 698   Code_Gen();
 699   if (failing())  return;
 700 
 701   // Check if we want to skip execution of all compiled code.
 702   {
 703 #ifndef PRODUCT
 704     if (OptoNoExecute) {
 705       record_method_not_compilable("+OptoNoExecute");  // Flag as failed
 706       return;
 707     }
 708     TracePhase t2("install_code", &_t_registerMethod, TimeCompiler);
 709 #endif
 710 
 711     if (is_osr_compilation()) {
 712       _code_offsets.set_value(CodeOffsets::Verified_Entry, 0);
 713       _code_offsets.set_value(CodeOffsets::OSR_Entry, _first_block_size);
 714     } else {
 715       _code_offsets.set_value(CodeOffsets::Verified_Entry, _first_block_size);
 716       _code_offsets.set_value(CodeOffsets::OSR_Entry, 0);
 717     }
 718 
 719     env()->register_method(_method, _entry_bci,
 720                            &_code_offsets,
 721                            _orig_pc_slot_offset_in_bytes,
 722                            code_buffer(),
 723                            frame_size_in_words(), _oop_map_set,
 724                            &_handler_table, &_inc_table,
 725                            compiler,
 726                            env()->comp_level(),
 727                            true, /*has_debug_info*/
 728                            has_unsafe_access()
 729                            );
 730   }
 731 }
 732 
 733 //------------------------------Compile----------------------------------------
 734 // Compile a runtime stub
 735 Compile::Compile( ciEnv* ci_env,
 736                   TypeFunc_generator generator,
 737                   address stub_function,
 738                   const char *stub_name,
 739                   int is_fancy_jump,
 740                   bool pass_tls,
 741                   bool save_arg_registers,
 742                   bool return_pc )
 743   : Phase(Compiler),
 744     _env(ci_env),
 745     _log(ci_env->log()),
 746     _compile_id(-1),
 747     _save_argument_registers(save_arg_registers),
 748     _method(NULL),
 749     _stub_name(stub_name),
 750     _stub_function(stub_function),
 751     _stub_entry_point(NULL),
 752     _entry_bci(InvocationEntryBci),
 753     _initial_gvn(NULL),
 754     _for_igvn(NULL),
 755     _warm_calls(NULL),
 756     _orig_pc_slot(0),
 757     _orig_pc_slot_offset_in_bytes(0),
 758     _subsume_loads(true),
 759     _do_escape_analysis(false),
 760     _failure_reason(NULL),
 761     _code_buffer("Compile::Fill_buffer"),
 762     _node_bundling_limit(0),
 763     _node_bundling_base(NULL),
 764     _java_calls(0),
 765     _inner_loops(0),
 766 #ifndef PRODUCT
 767     _trace_opto_output(TraceOptoOutput),
 768     _printer(NULL),
 769 #endif
 770     _congraph(NULL) {
 771   C = this;
 772 
 773 #ifndef PRODUCT
 774   TraceTime t1(NULL, &_t_totalCompilation, TimeCompiler, false);
 775   TraceTime t2(NULL, &_t_stubCompilation, TimeCompiler, false);
 776   set_print_assembly(PrintFrameConverterAssembly);
 777   set_parsed_irreducible_loop(false);
 778 #endif
 779   CompileWrapper cw(this);
 780   Init(/*AliasLevel=*/ 0);
 781   init_tf((*generator)());
 782 
 783   {
 784     // The following is a dummy for the sake of GraphKit::gen_stub
 785     Unique_Node_List for_igvn(comp_arena());
 786     set_for_igvn(&for_igvn);  // not used, but some GraphKit guys push on this
 787     PhaseGVN gvn(Thread::current()->resource_area(),255);
 788     set_initial_gvn(&gvn);    // not significant, but GraphKit guys use it pervasively
 789     gvn.transform_no_reclaim(top());
 790 
 791     GraphKit kit;
 792     kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
 793   }
 794 
 795   NOT_PRODUCT( verify_graph_edges(); )
 796   Code_Gen();
 797   if (failing())  return;
 798 
 799 
 800   // Entry point will be accessed using compile->stub_entry_point();
 801   if (code_buffer() == NULL) {
 802     Matcher::soft_match_failure();
 803   } else {
 804     if (PrintAssembly && (WizardMode || Verbose))
 805       tty->print_cr("### Stub::%s", stub_name);
 806 
 807     if (!failing()) {
 808       assert(_fixed_slots == 0, "no fixed slots used for runtime stubs");
 809 
 810       // Make the NMethod
 811       // For now we mark the frame as never safe for profile stackwalking
 812       RuntimeStub *rs = RuntimeStub::new_runtime_stub(stub_name,
 813                                                       code_buffer(),
 814                                                       CodeOffsets::frame_never_safe,
 815                                                       // _code_offsets.value(CodeOffsets::Frame_Complete),
 816                                                       frame_size_in_words(),
 817                                                       _oop_map_set,
 818                                                       save_arg_registers);
 819       assert(rs != NULL && rs->is_runtime_stub(), "sanity check");
 820 
 821       _stub_entry_point = rs->entry_point();
 822     }
 823   }
 824 }
 825 
 826 #ifndef PRODUCT
 827 void print_opto_verbose_signature( const TypeFunc *j_sig, const char *stub_name ) {
 828   if(PrintOpto && Verbose) {
 829     tty->print("%s   ", stub_name); j_sig->print_flattened(); tty->cr();
 830   }
 831 }
 832 #endif
 833 
 834 void Compile::print_codes() {
 835 }
 836 
 837 //------------------------------Init-------------------------------------------
 838 // Prepare for a single compilation
 839 void Compile::Init(int aliaslevel) {
 840   _unique  = 0;
 841   _regalloc = NULL;
 842 
 843   _tf      = NULL;  // filled in later
 844   _top     = NULL;  // cached later
 845   _matcher = NULL;  // filled in later
 846   _cfg     = NULL;  // filled in later
 847 
 848   set_24_bit_selection_and_mode(Use24BitFP, false);
 849 
 850   _node_note_array = NULL;
 851   _default_node_notes = NULL;
 852 
 853   _immutable_memory = NULL; // filled in at first inquiry
 854 
 855   // Globally visible Nodes
 856   // First set TOP to NULL to give safe behavior during creation of RootNode
 857   set_cached_top_node(NULL);
 858   set_root(new (this, 3) RootNode());
 859   // Now that you have a Root to point to, create the real TOP
 860   set_cached_top_node( new (this, 1) ConNode(Type::TOP) );
 861   set_recent_alloc(NULL, NULL);
 862 
 863   // Create Debug Information Recorder to record scopes, oopmaps, etc.
 864   env()->set_oop_recorder(new OopRecorder(comp_arena()));
 865   env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
 866   env()->set_dependencies(new Dependencies(env()));
 867 
 868   _fixed_slots = 0;
 869   set_has_split_ifs(false);
 870   set_has_loops(has_method() && method()->has_loops()); // first approximation
 871   set_has_stringbuilder(false);
 872   _deopt_happens = true;  // start out assuming the worst
 873   _trap_can_recompile = false;  // no traps emitted yet
 874   _major_progress = true; // start out assuming good things will happen
 875   set_has_unsafe_access(false);
 876   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
 877   set_decompile_count(0);
 878 
 879   set_do_freq_based_layout(BlockLayoutByFrequency || method_has_option("BlockLayoutByFrequency"));
 880   // Compilation level related initialization
 881   if (env()->comp_level() == CompLevel_fast_compile) {
 882     set_num_loop_opts(Tier1LoopOptsCount);
 883     set_do_inlining(Tier1Inline != 0);
 884     set_max_inline_size(Tier1MaxInlineSize);
 885     set_freq_inline_size(Tier1FreqInlineSize);
 886     set_do_scheduling(false);
 887     set_do_count_invocations(Tier1CountInvocations);
 888     set_do_method_data_update(Tier1UpdateMethodData);
 889   } else {
 890     assert(env()->comp_level() == CompLevel_full_optimization, "unknown comp level");
 891     set_num_loop_opts(LoopOptsCount);
 892     set_do_inlining(Inline);
 893     set_max_inline_size(MaxInlineSize);
 894     set_freq_inline_size(FreqInlineSize);
 895     set_do_scheduling(OptoScheduling);
 896     set_do_count_invocations(false);
 897     set_do_method_data_update(false);
 898   }
 899 
 900   if (debug_info()->recording_non_safepoints()) {
 901     set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
 902                         (comp_arena(), 8, 0, NULL));
 903     set_default_node_notes(Node_Notes::make(this));
 904   }
 905 
 906   // // -- Initialize types before each compile --
 907   // // Update cached type information
 908   // if( _method && _method->constants() )
 909   //   Type::update_loaded_types(_method, _method->constants());
 910 
 911   // Init alias_type map.
 912   if (!_do_escape_analysis && aliaslevel == 3)
 913     aliaslevel = 2;  // No unique types without escape analysis
 914   _AliasLevel = aliaslevel;
 915   const int grow_ats = 16;
 916   _max_alias_types = grow_ats;
 917   _alias_types   = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
 918   AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType,  grow_ats);
 919   Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
 920   {
 921     for (int i = 0; i < grow_ats; i++)  _alias_types[i] = &ats[i];
 922   }
 923   // Initialize the first few types.
 924   _alias_types[AliasIdxTop]->Init(AliasIdxTop, NULL);
 925   _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
 926   _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
 927   _num_alias_types = AliasIdxRaw+1;
 928   // Zero out the alias type cache.
 929   Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
 930   // A NULL adr_type hits in the cache right away.  Preload the right answer.
 931   probe_alias_cache(NULL)->_index = AliasIdxTop;
 932 
 933   _intrinsics = NULL;
 934   _macro_nodes = new GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
 935   register_library_intrinsics();
 936 }
 937 
 938 //---------------------------init_start----------------------------------------
 939 // Install the StartNode on this compile object.
 940 void Compile::init_start(StartNode* s) {
 941   if (failing())
 942     return; // already failing
 943   assert(s == start(), "");
 944 }
 945 
 946 StartNode* Compile::start() const {
 947   assert(!failing(), "");
 948   for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
 949     Node* start = root()->fast_out(i);
 950     if( start->is_Start() )
 951       return start->as_Start();
 952   }
 953   ShouldNotReachHere();
 954   return NULL;
 955 }
 956 
 957 //-------------------------------immutable_memory-------------------------------------
 958 // Access immutable memory
 959 Node* Compile::immutable_memory() {
 960   if (_immutable_memory != NULL) {
 961     return _immutable_memory;
 962   }
 963   StartNode* s = start();
 964   for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
 965     Node *p = s->fast_out(i);
 966     if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
 967       _immutable_memory = p;
 968       return _immutable_memory;
 969     }
 970   }
 971   ShouldNotReachHere();
 972   return NULL;
 973 }
 974 
 975 //----------------------set_cached_top_node------------------------------------
 976 // Install the cached top node, and make sure Node::is_top works correctly.
 977 void Compile::set_cached_top_node(Node* tn) {
 978   if (tn != NULL)  verify_top(tn);
 979   Node* old_top = _top;
 980   _top = tn;
 981   // Calling Node::setup_is_top allows the nodes the chance to adjust
 982   // their _out arrays.
 983   if (_top != NULL)     _top->setup_is_top();
 984   if (old_top != NULL)  old_top->setup_is_top();
 985   assert(_top == NULL || top()->is_top(), "");
 986 }
 987 
 988 #ifndef PRODUCT
 989 void Compile::verify_top(Node* tn) const {
 990   if (tn != NULL) {
 991     assert(tn->is_Con(), "top node must be a constant");
 992     assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
 993     assert(tn->in(0) != NULL, "must have live top node");
 994   }
 995 }
 996 #endif
 997 
 998 
 999 ///-------------------Managing Per-Node Debug & Profile Info-------------------
1000 
1001 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
1002   guarantee(arr != NULL, "");
1003   int num_blocks = arr->length();
1004   if (grow_by < num_blocks)  grow_by = num_blocks;
1005   int num_notes = grow_by * _node_notes_block_size;
1006   Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
1007   Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
1008   while (num_notes > 0) {
1009     arr->append(notes);
1010     notes     += _node_notes_block_size;
1011     num_notes -= _node_notes_block_size;
1012   }
1013   assert(num_notes == 0, "exact multiple, please");
1014 }
1015 
1016 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
1017   if (source == NULL || dest == NULL)  return false;
1018 
1019   if (dest->is_Con())
1020     return false;               // Do not push debug info onto constants.
1021 
1022 #ifdef ASSERT
1023   // Leave a bread crumb trail pointing to the original node:
1024   if (dest != NULL && dest != source && dest->debug_orig() == NULL) {
1025     dest->set_debug_orig(source);
1026   }
1027 #endif
1028 
1029   if (node_note_array() == NULL)
1030     return false;               // Not collecting any notes now.
1031 
1032   // This is a copy onto a pre-existing node, which may already have notes.
1033   // If both nodes have notes, do not overwrite any pre-existing notes.
1034   Node_Notes* source_notes = node_notes_at(source->_idx);
1035   if (source_notes == NULL || source_notes->is_clear())  return false;
1036   Node_Notes* dest_notes   = node_notes_at(dest->_idx);
1037   if (dest_notes == NULL || dest_notes->is_clear()) {
1038     return set_node_notes_at(dest->_idx, source_notes);
1039   }
1040 
1041   Node_Notes merged_notes = (*source_notes);
1042   // The order of operations here ensures that dest notes will win...
1043   merged_notes.update_from(dest_notes);
1044   return set_node_notes_at(dest->_idx, &merged_notes);
1045 }
1046 
1047 
1048 //--------------------------allow_range_check_smearing-------------------------
1049 // Gating condition for coalescing similar range checks.
1050 // Sometimes we try 'speculatively' replacing a series of a range checks by a
1051 // single covering check that is at least as strong as any of them.
1052 // If the optimization succeeds, the simplified (strengthened) range check
1053 // will always succeed.  If it fails, we will deopt, and then give up
1054 // on the optimization.
1055 bool Compile::allow_range_check_smearing() const {
1056   // If this method has already thrown a range-check,
1057   // assume it was because we already tried range smearing
1058   // and it failed.
1059   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
1060   return !already_trapped;
1061 }
1062 
1063 
1064 //------------------------------flatten_alias_type-----------------------------
1065 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
1066   int offset = tj->offset();
1067   TypePtr::PTR ptr = tj->ptr();
1068 
1069   // Known instance (scalarizable allocation) alias only with itself.
1070   bool is_known_inst = tj->isa_oopptr() != NULL &&
1071                        tj->is_oopptr()->is_known_instance();
1072 
1073   // Process weird unsafe references.
1074   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
1075     assert(InlineUnsafeOps, "indeterminate pointers come only from unsafe ops");
1076     assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
1077     tj = TypeOopPtr::BOTTOM;
1078     ptr = tj->ptr();
1079     offset = tj->offset();
1080   }
1081 
1082   // Array pointers need some flattening
1083   const TypeAryPtr *ta = tj->isa_aryptr();
1084   if( ta && is_known_inst ) {
1085     if ( offset != Type::OffsetBot &&
1086          offset > arrayOopDesc::length_offset_in_bytes() ) {
1087       offset = Type::OffsetBot; // Flatten constant access into array body only
1088       tj = ta = TypeAryPtr::make(ptr, ta->ary(), ta->klass(), true, offset, ta->instance_id());
1089     }
1090   } else if( ta && _AliasLevel >= 2 ) {
1091     // For arrays indexed by constant indices, we flatten the alias
1092     // space to include all of the array body.  Only the header, klass
1093     // and array length can be accessed un-aliased.
1094     if( offset != Type::OffsetBot ) {
1095       if( ta->const_oop() ) { // methodDataOop or methodOop
1096         offset = Type::OffsetBot;   // Flatten constant access into array body
1097         tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),ta->ary(),ta->klass(),false,offset);
1098       } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
1099         // range is OK as-is.
1100         tj = ta = TypeAryPtr::RANGE;
1101       } else if( offset == oopDesc::klass_offset_in_bytes() ) {
1102         tj = TypeInstPtr::KLASS; // all klass loads look alike
1103         ta = TypeAryPtr::RANGE; // generic ignored junk
1104         ptr = TypePtr::BotPTR;
1105       } else if( offset == oopDesc::mark_offset_in_bytes() ) {
1106         tj = TypeInstPtr::MARK;
1107         ta = TypeAryPtr::RANGE; // generic ignored junk
1108         ptr = TypePtr::BotPTR;
1109       } else {                  // Random constant offset into array body
1110         offset = Type::OffsetBot;   // Flatten constant access into array body
1111         tj = ta = TypeAryPtr::make(ptr,ta->ary(),ta->klass(),false,offset);
1112       }
1113     }
1114     // Arrays of fixed size alias with arrays of unknown size.
1115     if (ta->size() != TypeInt::POS) {
1116       const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
1117       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,ta->klass(),false,offset);
1118     }
1119     // Arrays of known objects become arrays of unknown objects.
1120     if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
1121       const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
1122       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1123     }
1124     if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
1125       const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
1126       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1127     }
1128     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
1129     // cannot be distinguished by bytecode alone.
1130     if (ta->elem() == TypeInt::BOOL) {
1131       const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
1132       ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
1133       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,offset);
1134     }
1135     // During the 2nd round of IterGVN, NotNull castings are removed.
1136     // Make sure the Bottom and NotNull variants alias the same.
1137     // Also, make sure exact and non-exact variants alias the same.
1138     if( ptr == TypePtr::NotNull || ta->klass_is_exact() ) {
1139       if (ta->const_oop()) {
1140         tj = ta = TypeAryPtr::make(TypePtr::Constant,ta->const_oop(),ta->ary(),ta->klass(),false,offset);
1141       } else {
1142         tj = ta = TypeAryPtr::make(TypePtr::BotPTR,ta->ary(),ta->klass(),false,offset);
1143       }
1144     }
1145   }
1146 
1147   // Oop pointers need some flattening
1148   const TypeInstPtr *to = tj->isa_instptr();
1149   if( to && _AliasLevel >= 2 && to != TypeOopPtr::BOTTOM ) {
1150     if( ptr == TypePtr::Constant ) {
1151       // No constant oop pointers (such as Strings); they alias with
1152       // unknown strings.
1153       assert(!is_known_inst, "not scalarizable allocation");
1154       tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1155     } else if( is_known_inst ) {
1156       tj = to; // Keep NotNull and klass_is_exact for instance type
1157     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
1158       // During the 2nd round of IterGVN, NotNull castings are removed.
1159       // Make sure the Bottom and NotNull variants alias the same.
1160       // Also, make sure exact and non-exact variants alias the same.
1161       tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1162     }
1163     // Canonicalize the holder of this field
1164     ciInstanceKlass *k = to->klass()->as_instance_klass();
1165     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
1166       // First handle header references such as a LoadKlassNode, even if the
1167       // object's klass is unloaded at compile time (4965979).
1168       if (!is_known_inst) { // Do it only for non-instance types
1169         tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, NULL, offset);
1170       }
1171     } else if (offset < 0 || offset >= k->size_helper() * wordSize) {
1172       to = NULL;
1173       tj = TypeOopPtr::BOTTOM;
1174       offset = tj->offset();
1175     } else {
1176       ciInstanceKlass *canonical_holder = k->get_canonical_holder(offset);
1177       if (!k->equals(canonical_holder) || tj->offset() != offset) {
1178         if( is_known_inst ) {
1179           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, true, NULL, offset, to->instance_id());
1180         } else {
1181           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, false, NULL, offset);
1182         }
1183       }
1184     }
1185   }
1186 
1187   // Klass pointers to object array klasses need some flattening
1188   const TypeKlassPtr *tk = tj->isa_klassptr();
1189   if( tk ) {
1190     // If we are referencing a field within a Klass, we need
1191     // to assume the worst case of an Object.  Both exact and
1192     // inexact types must flatten to the same alias class.
1193     // Since the flattened result for a klass is defined to be
1194     // precisely java.lang.Object, use a constant ptr.
1195     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
1196 
1197       tj = tk = TypeKlassPtr::make(TypePtr::Constant,
1198                                    TypeKlassPtr::OBJECT->klass(),
1199                                    offset);
1200     }
1201 
1202     ciKlass* klass = tk->klass();
1203     if( klass->is_obj_array_klass() ) {
1204       ciKlass* k = TypeAryPtr::OOPS->klass();
1205       if( !k || !k->is_loaded() )                  // Only fails for some -Xcomp runs
1206         k = TypeInstPtr::BOTTOM->klass();
1207       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, k, offset );
1208     }
1209 
1210     // Check for precise loads from the primary supertype array and force them
1211     // to the supertype cache alias index.  Check for generic array loads from
1212     // the primary supertype array and also force them to the supertype cache
1213     // alias index.  Since the same load can reach both, we need to merge
1214     // these 2 disparate memories into the same alias class.  Since the
1215     // primary supertype array is read-only, there's no chance of confusion
1216     // where we bypass an array load and an array store.
1217     uint off2 = offset - Klass::primary_supers_offset_in_bytes();
1218     if( offset == Type::OffsetBot ||
1219         off2 < Klass::primary_super_limit()*wordSize ) {
1220       offset = sizeof(oopDesc) +Klass::secondary_super_cache_offset_in_bytes();
1221       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, tk->klass(), offset );
1222     }
1223   }
1224 
1225   // Flatten all Raw pointers together.
1226   if (tj->base() == Type::RawPtr)
1227     tj = TypeRawPtr::BOTTOM;
1228 
1229   if (tj->base() == Type::AnyPtr)
1230     tj = TypePtr::BOTTOM;      // An error, which the caller must check for.
1231 
1232   // Flatten all to bottom for now
1233   switch( _AliasLevel ) {
1234   case 0:
1235     tj = TypePtr::BOTTOM;
1236     break;
1237   case 1:                       // Flatten to: oop, static, field or array
1238     switch (tj->base()) {
1239     //case Type::AryPtr: tj = TypeAryPtr::RANGE;    break;
1240     case Type::RawPtr:   tj = TypeRawPtr::BOTTOM;   break;
1241     case Type::AryPtr:   // do not distinguish arrays at all
1242     case Type::InstPtr:  tj = TypeInstPtr::BOTTOM;  break;
1243     case Type::KlassPtr: tj = TypeKlassPtr::OBJECT; break;
1244     case Type::AnyPtr:   tj = TypePtr::BOTTOM;      break;  // caller checks it
1245     default: ShouldNotReachHere();
1246     }
1247     break;
1248   case 2:                       // No collapsing at level 2; keep all splits
1249   case 3:                       // No collapsing at level 3; keep all splits
1250     break;
1251   default:
1252     Unimplemented();
1253   }
1254 
1255   offset = tj->offset();
1256   assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
1257 
1258   assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
1259           (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
1260           (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
1261           (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
1262           (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1263           (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1264           (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr)  ,
1265           "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
1266   assert( tj->ptr() != TypePtr::TopPTR &&
1267           tj->ptr() != TypePtr::AnyNull &&
1268           tj->ptr() != TypePtr::Null, "No imprecise addresses" );
1269 //    assert( tj->ptr() != TypePtr::Constant ||
1270 //            tj->base() == Type::RawPtr ||
1271 //            tj->base() == Type::KlassPtr, "No constant oop addresses" );
1272 
1273   return tj;
1274 }
1275 
1276 void Compile::AliasType::Init(int i, const TypePtr* at) {
1277   _index = i;
1278   _adr_type = at;
1279   _field = NULL;
1280   _is_rewritable = true; // default
1281   const TypeOopPtr *atoop = (at != NULL) ? at->isa_oopptr() : NULL;
1282   if (atoop != NULL && atoop->is_known_instance()) {
1283     const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
1284     _general_index = Compile::current()->get_alias_index(gt);
1285   } else {
1286     _general_index = 0;
1287   }
1288 }
1289 
1290 //---------------------------------print_on------------------------------------
1291 #ifndef PRODUCT
1292 void Compile::AliasType::print_on(outputStream* st) {
1293   if (index() < 10)
1294         st->print("@ <%d> ", index());
1295   else  st->print("@ <%d>",  index());
1296   st->print(is_rewritable() ? "   " : " RO");
1297   int offset = adr_type()->offset();
1298   if (offset == Type::OffsetBot)
1299         st->print(" +any");
1300   else  st->print(" +%-3d", offset);
1301   st->print(" in ");
1302   adr_type()->dump_on(st);
1303   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
1304   if (field() != NULL && tjp) {
1305     if (tjp->klass()  != field()->holder() ||
1306         tjp->offset() != field()->offset_in_bytes()) {
1307       st->print(" != ");
1308       field()->print();
1309       st->print(" ***");
1310     }
1311   }
1312 }
1313 
1314 void print_alias_types() {
1315   Compile* C = Compile::current();
1316   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
1317   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
1318     C->alias_type(idx)->print_on(tty);
1319     tty->cr();
1320   }
1321 }
1322 #endif
1323 
1324 
1325 //----------------------------probe_alias_cache--------------------------------
1326 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
1327   intptr_t key = (intptr_t) adr_type;
1328   key ^= key >> logAliasCacheSize;
1329   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
1330 }
1331 
1332 
1333 //-----------------------------grow_alias_types--------------------------------
1334 void Compile::grow_alias_types() {
1335   const int old_ats  = _max_alias_types; // how many before?
1336   const int new_ats  = old_ats;          // how many more?
1337   const int grow_ats = old_ats+new_ats;  // how many now?
1338   _max_alias_types = grow_ats;
1339   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
1340   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
1341   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
1342   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
1343 }
1344 
1345 
1346 //--------------------------------find_alias_type------------------------------
1347 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create) {
1348   if (_AliasLevel == 0)
1349     return alias_type(AliasIdxBot);
1350 
1351   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1352   if (ace->_adr_type == adr_type) {
1353     return alias_type(ace->_index);
1354   }
1355 
1356   // Handle special cases.
1357   if (adr_type == NULL)             return alias_type(AliasIdxTop);
1358   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
1359 
1360   // Do it the slow way.
1361   const TypePtr* flat = flatten_alias_type(adr_type);
1362 
1363 #ifdef ASSERT
1364   assert(flat == flatten_alias_type(flat), "idempotent");
1365   assert(flat != TypePtr::BOTTOM,     "cannot alias-analyze an untyped ptr");
1366   if (flat->isa_oopptr() && !flat->isa_klassptr()) {
1367     const TypeOopPtr* foop = flat->is_oopptr();
1368     // Scalarizable allocations have exact klass always.
1369     bool exact = !foop->klass_is_exact() || foop->is_known_instance();
1370     const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
1371     assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type");
1372   }
1373   assert(flat == flatten_alias_type(flat), "exact bit doesn't matter");
1374 #endif
1375 
1376   int idx = AliasIdxTop;
1377   for (int i = 0; i < num_alias_types(); i++) {
1378     if (alias_type(i)->adr_type() == flat) {
1379       idx = i;
1380       break;
1381     }
1382   }
1383 
1384   if (idx == AliasIdxTop) {
1385     if (no_create)  return NULL;
1386     // Grow the array if necessary.
1387     if (_num_alias_types == _max_alias_types)  grow_alias_types();
1388     // Add a new alias type.
1389     idx = _num_alias_types++;
1390     _alias_types[idx]->Init(idx, flat);
1391     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
1392     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
1393     if (flat->isa_instptr()) {
1394       if (flat->offset() == java_lang_Class::klass_offset_in_bytes()
1395           && flat->is_instptr()->klass() == env()->Class_klass())
1396         alias_type(idx)->set_rewritable(false);
1397     }
1398     if (flat->isa_klassptr()) {
1399       if (flat->offset() == Klass::super_check_offset_offset_in_bytes() + (int)sizeof(oopDesc))
1400         alias_type(idx)->set_rewritable(false);
1401       if (flat->offset() == Klass::modifier_flags_offset_in_bytes() + (int)sizeof(oopDesc))
1402         alias_type(idx)->set_rewritable(false);
1403       if (flat->offset() == Klass::access_flags_offset_in_bytes() + (int)sizeof(oopDesc))
1404         alias_type(idx)->set_rewritable(false);
1405       if (flat->offset() == Klass::java_mirror_offset_in_bytes() + (int)sizeof(oopDesc))
1406         alias_type(idx)->set_rewritable(false);
1407     }
1408     // %%% (We would like to finalize JavaThread::threadObj_offset(),
1409     // but the base pointer type is not distinctive enough to identify
1410     // references into JavaThread.)
1411 
1412     // Check for final instance fields.
1413     const TypeInstPtr* tinst = flat->isa_instptr();
1414     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
1415       ciInstanceKlass *k = tinst->klass()->as_instance_klass();
1416       ciField* field = k->get_field_by_offset(tinst->offset(), false);
1417       // Set field() and is_rewritable() attributes.
1418       if (field != NULL)  alias_type(idx)->set_field(field);
1419     }
1420     const TypeKlassPtr* tklass = flat->isa_klassptr();
1421     // Check for final static fields.
1422     if (tklass && tklass->klass()->is_instance_klass()) {
1423       ciInstanceKlass *k = tklass->klass()->as_instance_klass();
1424       ciField* field = k->get_field_by_offset(tklass->offset(), true);
1425       // Set field() and is_rewritable() attributes.
1426       if (field != NULL)   alias_type(idx)->set_field(field);
1427     }
1428   }
1429 
1430   // Fill the cache for next time.
1431   ace->_adr_type = adr_type;
1432   ace->_index    = idx;
1433   assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
1434 
1435   // Might as well try to fill the cache for the flattened version, too.
1436   AliasCacheEntry* face = probe_alias_cache(flat);
1437   if (face->_adr_type == NULL) {
1438     face->_adr_type = flat;
1439     face->_index    = idx;
1440     assert(alias_type(flat) == alias_type(idx), "flat type must work too");
1441   }
1442 
1443   return alias_type(idx);
1444 }
1445 
1446 
1447 Compile::AliasType* Compile::alias_type(ciField* field) {
1448   const TypeOopPtr* t;
1449   if (field->is_static())
1450     t = TypeKlassPtr::make(field->holder());
1451   else
1452     t = TypeOopPtr::make_from_klass_raw(field->holder());
1453   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()));
1454   assert(field->is_final() == !atp->is_rewritable(), "must get the rewritable bits correct");
1455   return atp;
1456 }
1457 
1458 
1459 //------------------------------have_alias_type--------------------------------
1460 bool Compile::have_alias_type(const TypePtr* adr_type) {
1461   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1462   if (ace->_adr_type == adr_type) {
1463     return true;
1464   }
1465 
1466   // Handle special cases.
1467   if (adr_type == NULL)             return true;
1468   if (adr_type == TypePtr::BOTTOM)  return true;
1469 
1470   return find_alias_type(adr_type, true) != NULL;
1471 }
1472 
1473 //-----------------------------must_alias--------------------------------------
1474 // True if all values of the given address type are in the given alias category.
1475 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
1476   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1477   if (adr_type == NULL)                 return true;  // NULL serves as TypePtr::TOP
1478   if (alias_idx == AliasIdxTop)         return false; // the empty category
1479   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
1480 
1481   // the only remaining possible overlap is identity
1482   int adr_idx = get_alias_index(adr_type);
1483   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1484   assert(adr_idx == alias_idx ||
1485          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
1486           && adr_type                       != TypeOopPtr::BOTTOM),
1487          "should not be testing for overlap with an unsafe pointer");
1488   return adr_idx == alias_idx;
1489 }
1490 
1491 //------------------------------can_alias--------------------------------------
1492 // True if any values of the given address type are in the given alias category.
1493 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
1494   if (alias_idx == AliasIdxTop)         return false; // the empty category
1495   if (adr_type == NULL)                 return false; // NULL serves as TypePtr::TOP
1496   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1497   if (adr_type->base() == Type::AnyPtr) return true;  // TypePtr::BOTTOM or its twins
1498 
1499   // the only remaining possible overlap is identity
1500   int adr_idx = get_alias_index(adr_type);
1501   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1502   return adr_idx == alias_idx;
1503 }
1504 
1505 
1506 
1507 //---------------------------pop_warm_call-------------------------------------
1508 WarmCallInfo* Compile::pop_warm_call() {
1509   WarmCallInfo* wci = _warm_calls;
1510   if (wci != NULL)  _warm_calls = wci->remove_from(wci);
1511   return wci;
1512 }
1513 
1514 //----------------------------Inline_Warm--------------------------------------
1515 int Compile::Inline_Warm() {
1516   // If there is room, try to inline some more warm call sites.
1517   // %%% Do a graph index compaction pass when we think we're out of space?
1518   if (!InlineWarmCalls)  return 0;
1519 
1520   int calls_made_hot = 0;
1521   int room_to_grow   = NodeCountInliningCutoff - unique();
1522   int amount_to_grow = MIN2(room_to_grow, (int)NodeCountInliningStep);
1523   int amount_grown   = 0;
1524   WarmCallInfo* call;
1525   while (amount_to_grow > 0 && (call = pop_warm_call()) != NULL) {
1526     int est_size = (int)call->size();
1527     if (est_size > (room_to_grow - amount_grown)) {
1528       // This one won't fit anyway.  Get rid of it.
1529       call->make_cold();
1530       continue;
1531     }
1532     call->make_hot();
1533     calls_made_hot++;
1534     amount_grown   += est_size;
1535     amount_to_grow -= est_size;
1536   }
1537 
1538   if (calls_made_hot > 0)  set_major_progress();
1539   return calls_made_hot;
1540 }
1541 
1542 
1543 //----------------------------Finish_Warm--------------------------------------
1544 void Compile::Finish_Warm() {
1545   if (!InlineWarmCalls)  return;
1546   if (failing())  return;
1547   if (warm_calls() == NULL)  return;
1548 
1549   // Clean up loose ends, if we are out of space for inlining.
1550   WarmCallInfo* call;
1551   while ((call = pop_warm_call()) != NULL) {
1552     call->make_cold();
1553   }
1554 }
1555 
1556 
1557 //------------------------------Optimize---------------------------------------
1558 // Given a graph, optimize it.
1559 void Compile::Optimize() {
1560   TracePhase t1("optimizer", &_t_optimizer, true);
1561 
1562 #ifndef PRODUCT
1563   if (env()->break_at_compile()) {
1564     BREAKPOINT;
1565   }
1566 
1567 #endif
1568 
1569   ResourceMark rm;
1570   int          loop_opts_cnt;
1571 
1572   NOT_PRODUCT( verify_graph_edges(); )
1573 
1574   print_method("After Parsing");
1575 
1576  {
1577   // Iterative Global Value Numbering, including ideal transforms
1578   // Initialize IterGVN with types and values from parse-time GVN
1579   PhaseIterGVN igvn(initial_gvn());
1580   {
1581     NOT_PRODUCT( TracePhase t2("iterGVN", &_t_iterGVN, TimeCompiler); )
1582     igvn.optimize();
1583   }
1584 
1585   print_method("Iter GVN 1", 2);
1586 
1587   if (failing())  return;
1588 
1589   // Loop transforms on the ideal graph.  Range Check Elimination,
1590   // peeling, unrolling, etc.
1591 
1592   // Set loop opts counter
1593   loop_opts_cnt = num_loop_opts();
1594   if((loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
1595     {
1596       TracePhase t2("idealLoop", &_t_idealLoop, true);
1597       PhaseIdealLoop ideal_loop( igvn, true );
1598       loop_opts_cnt--;
1599       if (major_progress()) print_method("PhaseIdealLoop 1", 2);
1600       if (failing())  return;
1601     }
1602     // Loop opts pass if partial peeling occurred in previous pass
1603     if(PartialPeelLoop && major_progress() && (loop_opts_cnt > 0)) {
1604       TracePhase t3("idealLoop", &_t_idealLoop, true);
1605       PhaseIdealLoop ideal_loop( igvn, false );
1606       loop_opts_cnt--;
1607       if (major_progress()) print_method("PhaseIdealLoop 2", 2);
1608       if (failing())  return;
1609     }
1610     // Loop opts pass for loop-unrolling before CCP
1611     if(major_progress() && (loop_opts_cnt > 0)) {
1612       TracePhase t4("idealLoop", &_t_idealLoop, true);
1613       PhaseIdealLoop ideal_loop( igvn, false );
1614       loop_opts_cnt--;
1615       if (major_progress()) print_method("PhaseIdealLoop 3", 2);
1616     }
1617     if (!failing()) {
1618       // Verify that last round of loop opts produced a valid graph
1619       NOT_PRODUCT( TracePhase t2("idealLoopVerify", &_t_idealLoopVerify, TimeCompiler); )
1620       PhaseIdealLoop::verify(igvn);
1621     }
1622   }
1623   if (failing())  return;
1624 
1625   // Conditional Constant Propagation;
1626   PhaseCCP ccp( &igvn );
1627   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
1628   {
1629     TracePhase t2("ccp", &_t_ccp, true);
1630     ccp.do_transform();
1631   }
1632   print_method("PhaseCPP 1", 2);
1633 
1634   assert( true, "Break here to ccp.dump_old2new_map()");
1635 
1636   // Iterative Global Value Numbering, including ideal transforms
1637   {
1638     NOT_PRODUCT( TracePhase t2("iterGVN2", &_t_iterGVN2, TimeCompiler); )
1639     igvn = ccp;
1640     igvn.optimize();
1641   }
1642 
1643   print_method("Iter GVN 2", 2);
1644 
1645   if (failing())  return;
1646 
1647   // Loop transforms on the ideal graph.  Range Check Elimination,
1648   // peeling, unrolling, etc.
1649   if(loop_opts_cnt > 0) {
1650     debug_only( int cnt = 0; );
1651     while(major_progress() && (loop_opts_cnt > 0)) {
1652       TracePhase t2("idealLoop", &_t_idealLoop, true);
1653       assert( cnt++ < 40, "infinite cycle in loop optimization" );
1654       PhaseIdealLoop ideal_loop( igvn, true );
1655       loop_opts_cnt--;
1656       if (major_progress()) print_method("PhaseIdealLoop iterations", 2);
1657       if (failing())  return;
1658     }
1659   }
1660 
1661   {
1662     // Verify that all previous optimizations produced a valid graph
1663     // at least to this point, even if no loop optimizations were done.
1664     NOT_PRODUCT( TracePhase t2("idealLoopVerify", &_t_idealLoopVerify, TimeCompiler); )
1665     PhaseIdealLoop::verify(igvn);
1666   }
1667 
1668   {
1669     NOT_PRODUCT( TracePhase t2("macroExpand", &_t_macroExpand, TimeCompiler); )
1670     PhaseMacroExpand  mex(igvn);
1671     if (mex.expand_macro_nodes()) {
1672       assert(failing(), "must bail out w/ explicit message");
1673       return;
1674     }
1675   }
1676 
1677  } // (End scope of igvn; run destructor if necessary for asserts.)
1678 
1679   // A method with only infinite loops has no edges entering loops from root
1680   {
1681     NOT_PRODUCT( TracePhase t2("graphReshape", &_t_graphReshaping, TimeCompiler); )
1682     if (final_graph_reshaping()) {
1683       assert(failing(), "must bail out w/ explicit message");
1684       return;
1685     }
1686   }
1687 
1688   print_method("Optimize finished", 2);
1689 }
1690 
1691 
1692 //------------------------------Code_Gen---------------------------------------
1693 // Given a graph, generate code for it
1694 void Compile::Code_Gen() {
1695   if (failing())  return;
1696 
1697   // Perform instruction selection.  You might think we could reclaim Matcher
1698   // memory PDQ, but actually the Matcher is used in generating spill code.
1699   // Internals of the Matcher (including some VectorSets) must remain live
1700   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
1701   // set a bit in reclaimed memory.
1702 
1703   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
1704   // nodes.  Mapping is only valid at the root of each matched subtree.
1705   NOT_PRODUCT( verify_graph_edges(); )
1706 
1707   Node_List proj_list;
1708   Matcher m(proj_list);
1709   _matcher = &m;
1710   {
1711     TracePhase t2("matcher", &_t_matcher, true);
1712     m.match();
1713   }
1714   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
1715   // nodes.  Mapping is only valid at the root of each matched subtree.
1716   NOT_PRODUCT( verify_graph_edges(); )
1717 
1718   // If you have too many nodes, or if matching has failed, bail out
1719   check_node_count(0, "out of nodes matching instructions");
1720   if (failing())  return;
1721 
1722   // Build a proper-looking CFG
1723   PhaseCFG cfg(node_arena(), root(), m);
1724   _cfg = &cfg;
1725   {
1726     NOT_PRODUCT( TracePhase t2("scheduler", &_t_scheduler, TimeCompiler); )
1727     cfg.Dominators();
1728     if (failing())  return;
1729 
1730     NOT_PRODUCT( verify_graph_edges(); )
1731 
1732     cfg.Estimate_Block_Frequency();
1733     cfg.GlobalCodeMotion(m,unique(),proj_list);
1734 
1735     print_method("Global code motion", 2);
1736 
1737     if (failing())  return;
1738     NOT_PRODUCT( verify_graph_edges(); )
1739 
1740     debug_only( cfg.verify(); )
1741   }
1742   NOT_PRODUCT( verify_graph_edges(); )
1743 
1744   PhaseChaitin regalloc(unique(),cfg,m);
1745   _regalloc = &regalloc;
1746   {
1747     TracePhase t2("regalloc", &_t_registerAllocation, true);
1748     // Perform any platform dependent preallocation actions.  This is used,
1749     // for example, to avoid taking an implicit null pointer exception
1750     // using the frame pointer on win95.
1751     _regalloc->pd_preallocate_hook();
1752 
1753     // Perform register allocation.  After Chaitin, use-def chains are
1754     // no longer accurate (at spill code) and so must be ignored.
1755     // Node->LRG->reg mappings are still accurate.
1756     _regalloc->Register_Allocate();
1757 
1758     // Bail out if the allocator builds too many nodes
1759     if (failing())  return;
1760   }
1761 
1762   // Prior to register allocation we kept empty basic blocks in case the
1763   // the allocator needed a place to spill.  After register allocation we
1764   // are not adding any new instructions.  If any basic block is empty, we
1765   // can now safely remove it.
1766   {
1767     NOT_PRODUCT( TracePhase t2("blockOrdering", &_t_blockOrdering, TimeCompiler); )
1768     cfg.remove_empty();
1769     if (do_freq_based_layout()) {
1770       PhaseBlockLayout layout(cfg);
1771     } else {
1772       cfg.set_loop_alignment();
1773     }
1774     cfg.fixup_flow();
1775   }
1776 
1777   // Perform any platform dependent postallocation verifications.
1778   debug_only( _regalloc->pd_postallocate_verify_hook(); )
1779 
1780   // Apply peephole optimizations
1781   if( OptoPeephole ) {
1782     NOT_PRODUCT( TracePhase t2("peephole", &_t_peephole, TimeCompiler); )
1783     PhasePeephole peep( _regalloc, cfg);
1784     peep.do_transform();
1785   }
1786 
1787   // Convert Nodes to instruction bits in a buffer
1788   {
1789     // %%%% workspace merge brought two timers together for one job
1790     TracePhase t2a("output", &_t_output, true);
1791     NOT_PRODUCT( TraceTime t2b(NULL, &_t_codeGeneration, TimeCompiler, false); )
1792     Output();
1793   }
1794 
1795   print_method("Final Code");
1796 
1797   // He's dead, Jim.
1798   _cfg     = (PhaseCFG*)0xdeadbeef;
1799   _regalloc = (PhaseChaitin*)0xdeadbeef;
1800 }
1801 
1802 
1803 //------------------------------dump_asm---------------------------------------
1804 // Dump formatted assembly
1805 #ifndef PRODUCT
1806 void Compile::dump_asm(int *pcs, uint pc_limit) {
1807   bool cut_short = false;
1808   tty->print_cr("#");
1809   tty->print("#  ");  _tf->dump();  tty->cr();
1810   tty->print_cr("#");
1811 
1812   // For all blocks
1813   int pc = 0x0;                 // Program counter
1814   char starts_bundle = ' ';
1815   _regalloc->dump_frame();
1816 
1817   Node *n = NULL;
1818   for( uint i=0; i<_cfg->_num_blocks; i++ ) {
1819     if (VMThread::should_terminate()) { cut_short = true; break; }
1820     Block *b = _cfg->_blocks[i];
1821     if (b->is_connector() && !Verbose) continue;
1822     n = b->_nodes[0];
1823     if (pcs && n->_idx < pc_limit)
1824       tty->print("%3.3x   ", pcs[n->_idx]);
1825     else
1826       tty->print("      ");
1827     b->dump_head( &_cfg->_bbs );
1828     if (b->is_connector()) {
1829       tty->print_cr("        # Empty connector block");
1830     } else if (b->num_preds() == 2 && b->pred(1)->is_CatchProj() && b->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
1831       tty->print_cr("        # Block is sole successor of call");
1832     }
1833 
1834     // For all instructions
1835     Node *delay = NULL;
1836     for( uint j = 0; j<b->_nodes.size(); j++ ) {
1837       if (VMThread::should_terminate()) { cut_short = true; break; }
1838       n = b->_nodes[j];
1839       if (valid_bundle_info(n)) {
1840         Bundle *bundle = node_bundling(n);
1841         if (bundle->used_in_unconditional_delay()) {
1842           delay = n;
1843           continue;
1844         }
1845         if (bundle->starts_bundle())
1846           starts_bundle = '+';
1847       }
1848 
1849       if (WizardMode) n->dump();
1850 
1851       if( !n->is_Region() &&    // Dont print in the Assembly
1852           !n->is_Phi() &&       // a few noisely useless nodes
1853           !n->is_Proj() &&
1854           !n->is_MachTemp() &&
1855           !n->is_SafePointScalarObject() &&
1856           !n->is_Catch() &&     // Would be nice to print exception table targets
1857           !n->is_MergeMem() &&  // Not very interesting
1858           !n->is_top() &&       // Debug info table constants
1859           !(n->is_Con() && !n->is_Mach())// Debug info table constants
1860           ) {
1861         if (pcs && n->_idx < pc_limit)
1862           tty->print("%3.3x", pcs[n->_idx]);
1863         else
1864           tty->print("   ");
1865         tty->print(" %c ", starts_bundle);
1866         starts_bundle = ' ';
1867         tty->print("\t");
1868         n->format(_regalloc, tty);
1869         tty->cr();
1870       }
1871 
1872       // If we have an instruction with a delay slot, and have seen a delay,
1873       // then back up and print it
1874       if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
1875         assert(delay != NULL, "no unconditional delay instruction");
1876         if (WizardMode) delay->dump();
1877 
1878         if (node_bundling(delay)->starts_bundle())
1879           starts_bundle = '+';
1880         if (pcs && n->_idx < pc_limit)
1881           tty->print("%3.3x", pcs[n->_idx]);
1882         else
1883           tty->print("   ");
1884         tty->print(" %c ", starts_bundle);
1885         starts_bundle = ' ';
1886         tty->print("\t");
1887         delay->format(_regalloc, tty);
1888         tty->print_cr("");
1889         delay = NULL;
1890       }
1891 
1892       // Dump the exception table as well
1893       if( n->is_Catch() && (Verbose || WizardMode) ) {
1894         // Print the exception table for this offset
1895         _handler_table.print_subtable_for(pc);
1896       }
1897     }
1898 
1899     if (pcs && n->_idx < pc_limit)
1900       tty->print_cr("%3.3x", pcs[n->_idx]);
1901     else
1902       tty->print_cr("");
1903 
1904     assert(cut_short || delay == NULL, "no unconditional delay branch");
1905 
1906   } // End of per-block dump
1907   tty->print_cr("");
1908 
1909   if (cut_short)  tty->print_cr("*** disassembly is cut short ***");
1910 }
1911 #endif
1912 
1913 //------------------------------Final_Reshape_Counts---------------------------
1914 // This class defines counters to help identify when a method
1915 // may/must be executed using hardware with only 24-bit precision.
1916 struct Final_Reshape_Counts : public StackObj {
1917   int  _call_count;             // count non-inlined 'common' calls
1918   int  _float_count;            // count float ops requiring 24-bit precision
1919   int  _double_count;           // count double ops requiring more precision
1920   int  _java_call_count;        // count non-inlined 'java' calls
1921   int  _inner_loop_count;       // count loops which need alignment
1922   VectorSet _visited;           // Visitation flags
1923   Node_List _tests;             // Set of IfNodes & PCTableNodes
1924 
1925   Final_Reshape_Counts() :
1926     _call_count(0), _float_count(0), _double_count(0),
1927     _java_call_count(0), _inner_loop_count(0),
1928     _visited( Thread::current()->resource_area() ) { }
1929 
1930   void inc_call_count  () { _call_count  ++; }
1931   void inc_float_count () { _float_count ++; }
1932   void inc_double_count() { _double_count++; }
1933   void inc_java_call_count() { _java_call_count++; }
1934   void inc_inner_loop_count() { _inner_loop_count++; }
1935 
1936   int  get_call_count  () const { return _call_count  ; }
1937   int  get_float_count () const { return _float_count ; }
1938   int  get_double_count() const { return _double_count; }
1939   int  get_java_call_count() const { return _java_call_count; }
1940   int  get_inner_loop_count() const { return _inner_loop_count; }
1941 };
1942 
1943 static bool oop_offset_is_sane(const TypeInstPtr* tp) {
1944   ciInstanceKlass *k = tp->klass()->as_instance_klass();
1945   // Make sure the offset goes inside the instance layout.
1946   return k->contains_field_offset(tp->offset());
1947   // Note that OffsetBot and OffsetTop are very negative.
1948 }
1949 
1950 //------------------------------final_graph_reshaping_impl----------------------
1951 // Implement items 1-5 from final_graph_reshaping below.
1952 static void final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &frc ) {
1953 
1954   if ( n->outcnt() == 0 ) return; // dead node
1955   uint nop = n->Opcode();
1956 
1957   // Check for 2-input instruction with "last use" on right input.
1958   // Swap to left input.  Implements item (2).
1959   if( n->req() == 3 &&          // two-input instruction
1960       n->in(1)->outcnt() > 1 && // left use is NOT a last use
1961       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
1962       n->in(2)->outcnt() == 1 &&// right use IS a last use
1963       !n->in(2)->is_Con() ) {   // right use is not a constant
1964     // Check for commutative opcode
1965     switch( nop ) {
1966     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddL:
1967     case Op_MaxI:  case Op_MinI:
1968     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulL:
1969     case Op_AndL:  case Op_XorL:  case Op_OrL:
1970     case Op_AndI:  case Op_XorI:  case Op_OrI: {
1971       // Move "last use" input to left by swapping inputs
1972       n->swap_edges(1, 2);
1973       break;
1974     }
1975     default:
1976       break;
1977     }
1978   }
1979 
1980   // Count FPU ops and common calls, implements item (3)
1981   switch( nop ) {
1982   // Count all float operations that may use FPU
1983   case Op_AddF:
1984   case Op_SubF:
1985   case Op_MulF:
1986   case Op_DivF:
1987   case Op_NegF:
1988   case Op_ModF:
1989   case Op_ConvI2F:
1990   case Op_ConF:
1991   case Op_CmpF:
1992   case Op_CmpF3:
1993   // case Op_ConvL2F: // longs are split into 32-bit halves
1994     frc.inc_float_count();
1995     break;
1996 
1997   case Op_ConvF2D:
1998   case Op_ConvD2F:
1999     frc.inc_float_count();
2000     frc.inc_double_count();
2001     break;
2002 
2003   // Count all double operations that may use FPU
2004   case Op_AddD:
2005   case Op_SubD:
2006   case Op_MulD:
2007   case Op_DivD:
2008   case Op_NegD:
2009   case Op_ModD:
2010   case Op_ConvI2D:
2011   case Op_ConvD2I:
2012   // case Op_ConvL2D: // handled by leaf call
2013   // case Op_ConvD2L: // handled by leaf call
2014   case Op_ConD:
2015   case Op_CmpD:
2016   case Op_CmpD3:
2017     frc.inc_double_count();
2018     break;
2019   case Op_Opaque1:              // Remove Opaque Nodes before matching
2020   case Op_Opaque2:              // Remove Opaque Nodes before matching
2021     n->subsume_by(n->in(1));
2022     break;
2023   case Op_CallStaticJava:
2024   case Op_CallJava:
2025   case Op_CallDynamicJava:
2026     frc.inc_java_call_count(); // Count java call site;
2027   case Op_CallRuntime:
2028   case Op_CallLeaf:
2029   case Op_CallLeafNoFP: {
2030     assert( n->is_Call(), "" );
2031     CallNode *call = n->as_Call();
2032     // Count call sites where the FP mode bit would have to be flipped.
2033     // Do not count uncommon runtime calls:
2034     // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
2035     // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
2036     if( !call->is_CallStaticJava() || !call->as_CallStaticJava()->_name ) {
2037       frc.inc_call_count();   // Count the call site
2038     } else {                  // See if uncommon argument is shared
2039       Node *n = call->in(TypeFunc::Parms);
2040       int nop = n->Opcode();
2041       // Clone shared simple arguments to uncommon calls, item (1).
2042       if( n->outcnt() > 1 &&
2043           !n->is_Proj() &&
2044           nop != Op_CreateEx &&
2045           nop != Op_CheckCastPP &&
2046           nop != Op_DecodeN &&
2047           !n->is_Mem() ) {
2048         Node *x = n->clone();
2049         call->set_req( TypeFunc::Parms, x );
2050       }
2051     }
2052     break;
2053   }
2054 
2055   case Op_StoreD:
2056   case Op_LoadD:
2057   case Op_LoadD_unaligned:
2058     frc.inc_double_count();
2059     goto handle_mem;
2060   case Op_StoreF:
2061   case Op_LoadF:
2062     frc.inc_float_count();
2063     goto handle_mem;
2064 
2065   case Op_StoreB:
2066   case Op_StoreC:
2067   case Op_StoreCM:
2068   case Op_StorePConditional:
2069   case Op_StoreI:
2070   case Op_StoreL:
2071   case Op_StoreIConditional:
2072   case Op_StoreLConditional:
2073   case Op_CompareAndSwapI:
2074   case Op_CompareAndSwapL:
2075   case Op_CompareAndSwapP:
2076   case Op_CompareAndSwapN:
2077   case Op_StoreP:
2078   case Op_StoreN:
2079   case Op_LoadB:
2080   case Op_LoadUB:
2081   case Op_LoadUS:
2082   case Op_LoadI:
2083   case Op_LoadUI2L:
2084   case Op_LoadKlass:
2085   case Op_LoadNKlass:
2086   case Op_LoadL:
2087   case Op_LoadL_unaligned:
2088   case Op_LoadPLocked:
2089   case Op_LoadLLocked:
2090   case Op_LoadP:
2091   case Op_LoadN:
2092   case Op_LoadRange:
2093   case Op_LoadS: {
2094   handle_mem:
2095 #ifdef ASSERT
2096     if( VerifyOptoOopOffsets ) {
2097       assert( n->is_Mem(), "" );
2098       MemNode *mem  = (MemNode*)n;
2099       // Check to see if address types have grounded out somehow.
2100       const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
2101       assert( !tp || oop_offset_is_sane(tp), "" );
2102     }
2103 #endif
2104     break;
2105   }
2106 
2107   case Op_AddP: {               // Assert sane base pointers
2108     Node *addp = n->in(AddPNode::Address);
2109     assert( !addp->is_AddP() ||
2110             addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
2111             addp->in(AddPNode::Base) == n->in(AddPNode::Base),
2112             "Base pointers must match" );
2113 #ifdef _LP64
2114     if (UseCompressedOops &&
2115         addp->Opcode() == Op_ConP &&
2116         addp == n->in(AddPNode::Base) &&
2117         n->in(AddPNode::Offset)->is_Con()) {
2118       // Use addressing with narrow klass to load with offset on x86.
2119       // On sparc loading 32-bits constant and decoding it have less
2120       // instructions (4) then load 64-bits constant (7).
2121       // Do this transformation here since IGVN will convert ConN back to ConP.
2122       const Type* t = addp->bottom_type();
2123       if (t->isa_oopptr()) {
2124         Node* nn = NULL;
2125 
2126         // Look for existing ConN node of the same exact type.
2127         Compile* C = Compile::current();
2128         Node* r  = C->root();
2129         uint cnt = r->outcnt();
2130         for (uint i = 0; i < cnt; i++) {
2131           Node* m = r->raw_out(i);
2132           if (m!= NULL && m->Opcode() == Op_ConN &&
2133               m->bottom_type()->make_ptr() == t) {
2134             nn = m;
2135             break;
2136           }
2137         }
2138         if (nn != NULL) {
2139           // Decode a narrow oop to match address
2140           // [R12 + narrow_oop_reg<<3 + offset]
2141           nn = new (C,  2) DecodeNNode(nn, t);
2142           n->set_req(AddPNode::Base, nn);
2143           n->set_req(AddPNode::Address, nn);
2144           if (addp->outcnt() == 0) {
2145             addp->disconnect_inputs(NULL);
2146           }
2147         }
2148       }
2149     }
2150 #endif
2151     break;
2152   }
2153 
2154 #ifdef _LP64
2155   case Op_CastPP:
2156     if (n->in(1)->is_DecodeN() && Universe::narrow_oop_use_implicit_null_checks()) {
2157       Compile* C = Compile::current();
2158       Node* in1 = n->in(1);
2159       const Type* t = n->bottom_type();
2160       Node* new_in1 = in1->clone();
2161       new_in1->as_DecodeN()->set_type(t);
2162 
2163       if (!Matcher::clone_shift_expressions) {
2164         //
2165         // x86, ARM and friends can handle 2 adds in addressing mode
2166         // and Matcher can fold a DecodeN node into address by using
2167         // a narrow oop directly and do implicit NULL check in address:
2168         //
2169         // [R12 + narrow_oop_reg<<3 + offset]
2170         // NullCheck narrow_oop_reg
2171         //
2172         // On other platforms (Sparc) we have to keep new DecodeN node and
2173         // use it to do implicit NULL check in address:
2174         //
2175         // decode_not_null narrow_oop_reg, base_reg
2176         // [base_reg + offset]
2177         // NullCheck base_reg
2178         //
2179         // Pin the new DecodeN node to non-null path on these platform (Sparc)
2180         // to keep the information to which NULL check the new DecodeN node
2181         // corresponds to use it as value in implicit_null_check().
2182         //
2183         new_in1->set_req(0, n->in(0));
2184       }
2185 
2186       n->subsume_by(new_in1);
2187       if (in1->outcnt() == 0) {
2188         in1->disconnect_inputs(NULL);
2189       }
2190     }
2191     break;
2192 
2193   case Op_CmpP:
2194     // Do this transformation here to preserve CmpPNode::sub() and
2195     // other TypePtr related Ideal optimizations (for example, ptr nullness).
2196     if (n->in(1)->is_DecodeN() || n->in(2)->is_DecodeN()) {
2197       Node* in1 = n->in(1);
2198       Node* in2 = n->in(2);
2199       if (!in1->is_DecodeN()) {
2200         in2 = in1;
2201         in1 = n->in(2);
2202       }
2203       assert(in1->is_DecodeN(), "sanity");
2204 
2205       Compile* C = Compile::current();
2206       Node* new_in2 = NULL;
2207       if (in2->is_DecodeN()) {
2208         new_in2 = in2->in(1);
2209       } else if (in2->Opcode() == Op_ConP) {
2210         const Type* t = in2->bottom_type();
2211         if (t == TypePtr::NULL_PTR && Universe::narrow_oop_use_implicit_null_checks()) {
2212           new_in2 = ConNode::make(C, TypeNarrowOop::NULL_PTR);
2213           //
2214           // This transformation together with CastPP transformation above
2215           // will generated code for implicit NULL checks for compressed oops.
2216           //
2217           // The original code after Optimize()
2218           //
2219           //    LoadN memory, narrow_oop_reg
2220           //    decode narrow_oop_reg, base_reg
2221           //    CmpP base_reg, NULL
2222           //    CastPP base_reg // NotNull
2223           //    Load [base_reg + offset], val_reg
2224           //
2225           // after these transformations will be
2226           //
2227           //    LoadN memory, narrow_oop_reg
2228           //    CmpN narrow_oop_reg, NULL
2229           //    decode_not_null narrow_oop_reg, base_reg
2230           //    Load [base_reg + offset], val_reg
2231           //
2232           // and the uncommon path (== NULL) will use narrow_oop_reg directly
2233           // since narrow oops can be used in debug info now (see the code in
2234           // final_graph_reshaping_walk()).
2235           //
2236           // At the end the code will be matched to
2237           // on x86:
2238           //
2239           //    Load_narrow_oop memory, narrow_oop_reg
2240           //    Load [R12 + narrow_oop_reg<<3 + offset], val_reg
2241           //    NullCheck narrow_oop_reg
2242           //
2243           // and on sparc:
2244           //
2245           //    Load_narrow_oop memory, narrow_oop_reg
2246           //    decode_not_null narrow_oop_reg, base_reg
2247           //    Load [base_reg + offset], val_reg
2248           //    NullCheck base_reg
2249           //
2250         } else if (t->isa_oopptr()) {
2251           new_in2 = ConNode::make(C, t->make_narrowoop());
2252         }
2253       }
2254       if (new_in2 != NULL) {
2255         Node* cmpN = new (C, 3) CmpNNode(in1->in(1), new_in2);
2256         n->subsume_by( cmpN );
2257         if (in1->outcnt() == 0) {
2258           in1->disconnect_inputs(NULL);
2259         }
2260         if (in2->outcnt() == 0) {
2261           in2->disconnect_inputs(NULL);
2262         }
2263       }
2264     }
2265     break;
2266 
2267   case Op_DecodeN:
2268     assert(!n->in(1)->is_EncodeP(), "should be optimized out");
2269     // DecodeN could be pinned on Sparc where it can't be fold into
2270     // an address expression, see the code for Op_CastPP above.
2271     assert(n->in(0) == NULL || !Matcher::clone_shift_expressions, "no control except on sparc");
2272     break;
2273 
2274   case Op_EncodeP: {
2275     Node* in1 = n->in(1);
2276     if (in1->is_DecodeN()) {
2277       n->subsume_by(in1->in(1));
2278     } else if (in1->Opcode() == Op_ConP) {
2279       Compile* C = Compile::current();
2280       const Type* t = in1->bottom_type();
2281       if (t == TypePtr::NULL_PTR) {
2282         n->subsume_by(ConNode::make(C, TypeNarrowOop::NULL_PTR));
2283       } else if (t->isa_oopptr()) {
2284         n->subsume_by(ConNode::make(C, t->make_narrowoop()));
2285       }
2286     }
2287     if (in1->outcnt() == 0) {
2288       in1->disconnect_inputs(NULL);
2289     }
2290     break;
2291   }
2292 
2293   case Op_Proj: {
2294     if (OptimizeStringConcat) {
2295       ProjNode* p = n->as_Proj();
2296       if (p->_is_io_use) {
2297         // Separate projections were used for the exception path which
2298         // are normally removed by a late inline.  If it wasn't inlined
2299         // then they will hang around and should just be replaced with
2300         // the original one.
2301         Node* proj = NULL;
2302         // Replace with just one
2303         for (SimpleDUIterator i(p->in(0)); i.has_next(); i.next()) {
2304           Node *use = i.get();
2305           if (use->is_Proj() && p != use && use->as_Proj()->_con == p->_con) {
2306             proj = use;
2307             break;
2308           }
2309         }
2310         assert(p != NULL, "must be found");
2311         p->subsume_by(proj);
2312       }
2313     }
2314     break;
2315   }
2316 
2317   case Op_Phi:
2318     if (n->as_Phi()->bottom_type()->isa_narrowoop()) {
2319       // The EncodeP optimization may create Phi with the same edges
2320       // for all paths. It is not handled well by Register Allocator.
2321       Node* unique_in = n->in(1);
2322       assert(unique_in != NULL, "");
2323       uint cnt = n->req();
2324       for (uint i = 2; i < cnt; i++) {
2325         Node* m = n->in(i);
2326         assert(m != NULL, "");
2327         if (unique_in != m)
2328           unique_in = NULL;
2329       }
2330       if (unique_in != NULL) {
2331         n->subsume_by(unique_in);
2332       }
2333     }
2334     break;
2335 
2336 #endif
2337 
2338   case Op_ModI:
2339     if (UseDivMod) {
2340       // Check if a%b and a/b both exist
2341       Node* d = n->find_similar(Op_DivI);
2342       if (d) {
2343         // Replace them with a fused divmod if supported
2344         Compile* C = Compile::current();
2345         if (Matcher::has_match_rule(Op_DivModI)) {
2346           DivModINode* divmod = DivModINode::make(C, n);
2347           d->subsume_by(divmod->div_proj());
2348           n->subsume_by(divmod->mod_proj());
2349         } else {
2350           // replace a%b with a-((a/b)*b)
2351           Node* mult = new (C, 3) MulINode(d, d->in(2));
2352           Node* sub  = new (C, 3) SubINode(d->in(1), mult);
2353           n->subsume_by( sub );
2354         }
2355       }
2356     }
2357     break;
2358 
2359   case Op_ModL:
2360     if (UseDivMod) {
2361       // Check if a%b and a/b both exist
2362       Node* d = n->find_similar(Op_DivL);
2363       if (d) {
2364         // Replace them with a fused divmod if supported
2365         Compile* C = Compile::current();
2366         if (Matcher::has_match_rule(Op_DivModL)) {
2367           DivModLNode* divmod = DivModLNode::make(C, n);
2368           d->subsume_by(divmod->div_proj());
2369           n->subsume_by(divmod->mod_proj());
2370         } else {
2371           // replace a%b with a-((a/b)*b)
2372           Node* mult = new (C, 3) MulLNode(d, d->in(2));
2373           Node* sub  = new (C, 3) SubLNode(d->in(1), mult);
2374           n->subsume_by( sub );
2375         }
2376       }
2377     }
2378     break;
2379 
2380   case Op_Load16B:
2381   case Op_Load8B:
2382   case Op_Load4B:
2383   case Op_Load8S:
2384   case Op_Load4S:
2385   case Op_Load2S:
2386   case Op_Load8C:
2387   case Op_Load4C:
2388   case Op_Load2C:
2389   case Op_Load4I:
2390   case Op_Load2I:
2391   case Op_Load2L:
2392   case Op_Load4F:
2393   case Op_Load2F:
2394   case Op_Load2D:
2395   case Op_Store16B:
2396   case Op_Store8B:
2397   case Op_Store4B:
2398   case Op_Store8C:
2399   case Op_Store4C:
2400   case Op_Store2C:
2401   case Op_Store4I:
2402   case Op_Store2I:
2403   case Op_Store2L:
2404   case Op_Store4F:
2405   case Op_Store2F:
2406   case Op_Store2D:
2407     break;
2408 
2409   case Op_PackB:
2410   case Op_PackS:
2411   case Op_PackC:
2412   case Op_PackI:
2413   case Op_PackF:
2414   case Op_PackL:
2415   case Op_PackD:
2416     if (n->req()-1 > 2) {
2417       // Replace many operand PackNodes with a binary tree for matching
2418       PackNode* p = (PackNode*) n;
2419       Node* btp = p->binaryTreePack(Compile::current(), 1, n->req());
2420       n->subsume_by(btp);
2421     }
2422     break;
2423   case Op_Loop:
2424   case Op_CountedLoop:
2425     if (n->as_Loop()->is_inner_loop()) {
2426       frc.inc_inner_loop_count();
2427     }
2428     break;
2429   default:
2430     assert( !n->is_Call(), "" );
2431     assert( !n->is_Mem(), "" );
2432     break;
2433   }
2434 
2435   // Collect CFG split points
2436   if (n->is_MultiBranch())
2437     frc._tests.push(n);
2438 }
2439 
2440 //------------------------------final_graph_reshaping_walk---------------------
2441 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
2442 // requires that the walk visits a node's inputs before visiting the node.
2443 static void final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Reshape_Counts &frc ) {
2444   ResourceArea *area = Thread::current()->resource_area();
2445   Unique_Node_List sfpt(area);
2446 
2447   frc._visited.set(root->_idx); // first, mark node as visited
2448   uint cnt = root->req();
2449   Node *n = root;
2450   uint  i = 0;
2451   while (true) {
2452     if (i < cnt) {
2453       // Place all non-visited non-null inputs onto stack
2454       Node* m = n->in(i);
2455       ++i;
2456       if (m != NULL && !frc._visited.test_set(m->_idx)) {
2457         if (m->is_SafePoint() && m->as_SafePoint()->jvms() != NULL)
2458           sfpt.push(m);
2459         cnt = m->req();
2460         nstack.push(n, i); // put on stack parent and next input's index
2461         n = m;
2462         i = 0;
2463       }
2464     } else {
2465       // Now do post-visit work
2466       final_graph_reshaping_impl( n, frc );
2467       if (nstack.is_empty())
2468         break;             // finished
2469       n = nstack.node();   // Get node from stack
2470       cnt = n->req();
2471       i = nstack.index();
2472       nstack.pop();        // Shift to the next node on stack
2473     }
2474   }
2475 
2476   // Go over safepoints nodes to skip DecodeN nodes for debug edges.
2477   // It could be done for an uncommon traps or any safepoints/calls
2478   // if the DecodeN node is referenced only in a debug info.
2479   while (sfpt.size() > 0) {
2480     n = sfpt.pop();
2481     JVMState *jvms = n->as_SafePoint()->jvms();
2482     assert(jvms != NULL, "sanity");
2483     int start = jvms->debug_start();
2484     int end   = n->req();
2485     bool is_uncommon = (n->is_CallStaticJava() &&
2486                         n->as_CallStaticJava()->uncommon_trap_request() != 0);
2487     for (int j = start; j < end; j++) {
2488       Node* in = n->in(j);
2489       if (in->is_DecodeN()) {
2490         bool safe_to_skip = true;
2491         if (!is_uncommon ) {
2492           // Is it safe to skip?
2493           for (uint i = 0; i < in->outcnt(); i++) {
2494             Node* u = in->raw_out(i);
2495             if (!u->is_SafePoint() ||
2496                  u->is_Call() && u->as_Call()->has_non_debug_use(n)) {
2497               safe_to_skip = false;
2498             }
2499           }
2500         }
2501         if (safe_to_skip) {
2502           n->set_req(j, in->in(1));
2503         }
2504         if (in->outcnt() == 0) {
2505           in->disconnect_inputs(NULL);
2506         }
2507       }
2508     }
2509   }
2510 }
2511 
2512 //------------------------------final_graph_reshaping--------------------------
2513 // Final Graph Reshaping.
2514 //
2515 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
2516 //     and not commoned up and forced early.  Must come after regular
2517 //     optimizations to avoid GVN undoing the cloning.  Clone constant
2518 //     inputs to Loop Phis; these will be split by the allocator anyways.
2519 //     Remove Opaque nodes.
2520 // (2) Move last-uses by commutative operations to the left input to encourage
2521 //     Intel update-in-place two-address operations and better register usage
2522 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
2523 //     calls canonicalizing them back.
2524 // (3) Count the number of double-precision FP ops, single-precision FP ops
2525 //     and call sites.  On Intel, we can get correct rounding either by
2526 //     forcing singles to memory (requires extra stores and loads after each
2527 //     FP bytecode) or we can set a rounding mode bit (requires setting and
2528 //     clearing the mode bit around call sites).  The mode bit is only used
2529 //     if the relative frequency of single FP ops to calls is low enough.
2530 //     This is a key transform for SPEC mpeg_audio.
2531 // (4) Detect infinite loops; blobs of code reachable from above but not
2532 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
2533 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
2534 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
2535 //     Detection is by looking for IfNodes where only 1 projection is
2536 //     reachable from below or CatchNodes missing some targets.
2537 // (5) Assert for insane oop offsets in debug mode.
2538 
2539 bool Compile::final_graph_reshaping() {
2540   // an infinite loop may have been eliminated by the optimizer,
2541   // in which case the graph will be empty.
2542   if (root()->req() == 1) {
2543     record_method_not_compilable("trivial infinite loop");
2544     return true;
2545   }
2546 
2547   Final_Reshape_Counts frc;
2548 
2549   // Visit everybody reachable!
2550   // Allocate stack of size C->unique()/2 to avoid frequent realloc
2551   Node_Stack nstack(unique() >> 1);
2552   final_graph_reshaping_walk(nstack, root(), frc);
2553 
2554   // Check for unreachable (from below) code (i.e., infinite loops).
2555   for( uint i = 0; i < frc._tests.size(); i++ ) {
2556     MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
2557     // Get number of CFG targets.
2558     // Note that PCTables include exception targets after calls.
2559     uint required_outcnt = n->required_outcnt();
2560     if (n->outcnt() != required_outcnt) {
2561       // Check for a few special cases.  Rethrow Nodes never take the
2562       // 'fall-thru' path, so expected kids is 1 less.
2563       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
2564         if (n->in(0)->in(0)->is_Call()) {
2565           CallNode *call = n->in(0)->in(0)->as_Call();
2566           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
2567             required_outcnt--;      // Rethrow always has 1 less kid
2568           } else if (call->req() > TypeFunc::Parms &&
2569                      call->is_CallDynamicJava()) {
2570             // Check for null receiver. In such case, the optimizer has
2571             // detected that the virtual call will always result in a null
2572             // pointer exception. The fall-through projection of this CatchNode
2573             // will not be populated.
2574             Node *arg0 = call->in(TypeFunc::Parms);
2575             if (arg0->is_Type() &&
2576                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
2577               required_outcnt--;
2578             }
2579           } else if (call->entry_point() == OptoRuntime::new_array_Java() &&
2580                      call->req() > TypeFunc::Parms+1 &&
2581                      call->is_CallStaticJava()) {
2582             // Check for negative array length. In such case, the optimizer has
2583             // detected that the allocation attempt will always result in an
2584             // exception. There is no fall-through projection of this CatchNode .
2585             Node *arg1 = call->in(TypeFunc::Parms+1);
2586             if (arg1->is_Type() &&
2587                 arg1->as_Type()->type()->join(TypeInt::POS)->empty()) {
2588               required_outcnt--;
2589             }
2590           }
2591         }
2592       }
2593       // Recheck with a better notion of 'required_outcnt'
2594       if (n->outcnt() != required_outcnt) {
2595         record_method_not_compilable("malformed control flow");
2596         return true;            // Not all targets reachable!
2597       }
2598     }
2599     // Check that I actually visited all kids.  Unreached kids
2600     // must be infinite loops.
2601     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
2602       if (!frc._visited.test(n->fast_out(j)->_idx)) {
2603         record_method_not_compilable("infinite loop");
2604         return true;            // Found unvisited kid; must be unreach
2605       }
2606   }
2607 
2608   // If original bytecodes contained a mixture of floats and doubles
2609   // check if the optimizer has made it homogenous, item (3).
2610   if( Use24BitFPMode && Use24BitFP && UseSSE == 0 &&
2611       frc.get_float_count() > 32 &&
2612       frc.get_double_count() == 0 &&
2613       (10 * frc.get_call_count() < frc.get_float_count()) ) {
2614     set_24_bit_selection_and_mode( false,  true );
2615   }
2616 
2617   set_java_calls(frc.get_java_call_count());
2618   set_inner_loops(frc.get_inner_loop_count());
2619 
2620   // No infinite loops, no reason to bail out.
2621   return false;
2622 }
2623 
2624 //-----------------------------too_many_traps----------------------------------
2625 // Report if there are too many traps at the current method and bci.
2626 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
2627 bool Compile::too_many_traps(ciMethod* method,
2628                              int bci,
2629                              Deoptimization::DeoptReason reason) {
2630   ciMethodData* md = method->method_data();
2631   if (md->is_empty()) {
2632     // Assume the trap has not occurred, or that it occurred only
2633     // because of a transient condition during start-up in the interpreter.
2634     return false;
2635   }
2636   if (md->has_trap_at(bci, reason) != 0) {
2637     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
2638     // Also, if there are multiple reasons, or if there is no per-BCI record,
2639     // assume the worst.
2640     if (log())
2641       log()->elem("observe trap='%s' count='%d'",
2642                   Deoptimization::trap_reason_name(reason),
2643                   md->trap_count(reason));
2644     return true;
2645   } else {
2646     // Ignore method/bci and see if there have been too many globally.
2647     return too_many_traps(reason, md);
2648   }
2649 }
2650 
2651 // Less-accurate variant which does not require a method and bci.
2652 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
2653                              ciMethodData* logmd) {
2654  if (trap_count(reason) >= (uint)PerMethodTrapLimit) {
2655     // Too many traps globally.
2656     // Note that we use cumulative trap_count, not just md->trap_count.
2657     if (log()) {
2658       int mcount = (logmd == NULL)? -1: (int)logmd->trap_count(reason);
2659       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
2660                   Deoptimization::trap_reason_name(reason),
2661                   mcount, trap_count(reason));
2662     }
2663     return true;
2664   } else {
2665     // The coast is clear.
2666     return false;
2667   }
2668 }
2669 
2670 //--------------------------too_many_recompiles--------------------------------
2671 // Report if there are too many recompiles at the current method and bci.
2672 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
2673 // Is not eager to return true, since this will cause the compiler to use
2674 // Action_none for a trap point, to avoid too many recompilations.
2675 bool Compile::too_many_recompiles(ciMethod* method,
2676                                   int bci,
2677                                   Deoptimization::DeoptReason reason) {
2678   ciMethodData* md = method->method_data();
2679   if (md->is_empty()) {
2680     // Assume the trap has not occurred, or that it occurred only
2681     // because of a transient condition during start-up in the interpreter.
2682     return false;
2683   }
2684   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
2685   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
2686   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
2687   Deoptimization::DeoptReason per_bc_reason
2688     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
2689   if ((per_bc_reason == Deoptimization::Reason_none
2690        || md->has_trap_at(bci, reason) != 0)
2691       // The trap frequency measure we care about is the recompile count:
2692       && md->trap_recompiled_at(bci)
2693       && md->overflow_recompile_count() >= bc_cutoff) {
2694     // Do not emit a trap here if it has already caused recompilations.
2695     // Also, if there are multiple reasons, or if there is no per-BCI record,
2696     // assume the worst.
2697     if (log())
2698       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
2699                   Deoptimization::trap_reason_name(reason),
2700                   md->trap_count(reason),
2701                   md->overflow_recompile_count());
2702     return true;
2703   } else if (trap_count(reason) != 0
2704              && decompile_count() >= m_cutoff) {
2705     // Too many recompiles globally, and we have seen this sort of trap.
2706     // Use cumulative decompile_count, not just md->decompile_count.
2707     if (log())
2708       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
2709                   Deoptimization::trap_reason_name(reason),
2710                   md->trap_count(reason), trap_count(reason),
2711                   md->decompile_count(), decompile_count());
2712     return true;
2713   } else {
2714     // The coast is clear.
2715     return false;
2716   }
2717 }
2718 
2719 
2720 #ifndef PRODUCT
2721 //------------------------------verify_graph_edges---------------------------
2722 // Walk the Graph and verify that there is a one-to-one correspondence
2723 // between Use-Def edges and Def-Use edges in the graph.
2724 void Compile::verify_graph_edges(bool no_dead_code) {
2725   if (VerifyGraphEdges) {
2726     ResourceArea *area = Thread::current()->resource_area();
2727     Unique_Node_List visited(area);
2728     // Call recursive graph walk to check edges
2729     _root->verify_edges(visited);
2730     if (no_dead_code) {
2731       // Now make sure that no visited node is used by an unvisited node.
2732       bool dead_nodes = 0;
2733       Unique_Node_List checked(area);
2734       while (visited.size() > 0) {
2735         Node* n = visited.pop();
2736         checked.push(n);
2737         for (uint i = 0; i < n->outcnt(); i++) {
2738           Node* use = n->raw_out(i);
2739           if (checked.member(use))  continue;  // already checked
2740           if (visited.member(use))  continue;  // already in the graph
2741           if (use->is_Con())        continue;  // a dead ConNode is OK
2742           // At this point, we have found a dead node which is DU-reachable.
2743           if (dead_nodes++ == 0)
2744             tty->print_cr("*** Dead nodes reachable via DU edges:");
2745           use->dump(2);
2746           tty->print_cr("---");
2747           checked.push(use);  // No repeats; pretend it is now checked.
2748         }
2749       }
2750       assert(dead_nodes == 0, "using nodes must be reachable from root");
2751     }
2752   }
2753 }
2754 #endif
2755 
2756 // The Compile object keeps track of failure reasons separately from the ciEnv.
2757 // This is required because there is not quite a 1-1 relation between the
2758 // ciEnv and its compilation task and the Compile object.  Note that one
2759 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
2760 // to backtrack and retry without subsuming loads.  Other than this backtracking
2761 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
2762 // by the logic in C2Compiler.
2763 void Compile::record_failure(const char* reason) {
2764   if (log() != NULL) {
2765     log()->elem("failure reason='%s' phase='compile'", reason);
2766   }
2767   if (_failure_reason == NULL) {
2768     // Record the first failure reason.
2769     _failure_reason = reason;
2770   }
2771   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
2772     C->print_method(_failure_reason);
2773   }
2774   _root = NULL;  // flush the graph, too
2775 }
2776 
2777 Compile::TracePhase::TracePhase(const char* name, elapsedTimer* accumulator, bool dolog)
2778   : TraceTime(NULL, accumulator, false NOT_PRODUCT( || TimeCompiler ), false)
2779 {
2780   if (dolog) {
2781     C = Compile::current();
2782     _log = C->log();
2783   } else {
2784     C = NULL;
2785     _log = NULL;
2786   }
2787   if (_log != NULL) {
2788     _log->begin_head("phase name='%s' nodes='%d'", name, C->unique());
2789     _log->stamp();
2790     _log->end_head();
2791   }
2792 }
2793 
2794 Compile::TracePhase::~TracePhase() {
2795   if (_log != NULL) {
2796     _log->done("phase nodes='%d'", C->unique());
2797   }
2798 }