1 /*
   2  * Copyright (c) 1997, 2019, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "asm/macroAssembler.hpp"
  27 #include "asm/macroAssembler.inline.hpp"
  28 #include "ci/ciReplay.hpp"
  29 #include "classfile/systemDictionary.hpp"
  30 #include "code/exceptionHandlerTable.hpp"
  31 #include "code/nmethod.hpp"
  32 #include "compiler/compileBroker.hpp"
  33 #include "compiler/compileLog.hpp"
  34 #include "compiler/disassembler.hpp"
  35 #include "compiler/oopMap.hpp"
  36 #include "gc/shared/barrierSet.hpp"
  37 #include "gc/shared/c2/barrierSetC2.hpp"
  38 #include "memory/resourceArea.hpp"
  39 #include "opto/addnode.hpp"
  40 #include "opto/block.hpp"
  41 #include "opto/c2compiler.hpp"
  42 #include "opto/callGenerator.hpp"
  43 #include "opto/callnode.hpp"
  44 #include "opto/castnode.hpp"
  45 #include "opto/cfgnode.hpp"
  46 #include "opto/chaitin.hpp"
  47 #include "opto/compile.hpp"
  48 #include "opto/connode.hpp"
  49 #include "opto/convertnode.hpp"
  50 #include "opto/divnode.hpp"
  51 #include "opto/escape.hpp"
  52 #include "opto/idealGraphPrinter.hpp"
  53 #include "opto/loopnode.hpp"
  54 #include "opto/machnode.hpp"
  55 #include "opto/macro.hpp"
  56 #include "opto/matcher.hpp"
  57 #include "opto/mathexactnode.hpp"
  58 #include "opto/memnode.hpp"
  59 #include "opto/mulnode.hpp"
  60 #include "opto/narrowptrnode.hpp"
  61 #include "opto/node.hpp"
  62 #include "opto/opcodes.hpp"
  63 #include "opto/output.hpp"
  64 #include "opto/parse.hpp"
  65 #include "opto/phaseX.hpp"
  66 #include "opto/rootnode.hpp"
  67 #include "opto/runtime.hpp"
  68 #include "opto/stringopts.hpp"
  69 #include "opto/type.hpp"
  70 #include "opto/valuetypenode.hpp"
  71 #include "opto/vectornode.hpp"
  72 #include "runtime/arguments.hpp"
  73 #include "runtime/sharedRuntime.hpp"
  74 #include "runtime/signature.hpp"
  75 #include "runtime/stubRoutines.hpp"
  76 #include "runtime/timer.hpp"
  77 #include "utilities/align.hpp"
  78 #include "utilities/copy.hpp"
  79 #include "utilities/macros.hpp"
  80 #if INCLUDE_ZGC
  81 #include "gc/z/c2/zBarrierSetC2.hpp"
  82 #endif
  83 
  84 
  85 // -------------------- Compile::mach_constant_base_node -----------------------
  86 // Constant table base node singleton.
  87 MachConstantBaseNode* Compile::mach_constant_base_node() {
  88   if (_mach_constant_base_node == NULL) {
  89     _mach_constant_base_node = new MachConstantBaseNode();
  90     _mach_constant_base_node->add_req(C->root());
  91   }
  92   return _mach_constant_base_node;
  93 }
  94 
  95 
  96 /// Support for intrinsics.
  97 
  98 // Return the index at which m must be inserted (or already exists).
  99 // The sort order is by the address of the ciMethod, with is_virtual as minor key.
 100 class IntrinsicDescPair {
 101  private:
 102   ciMethod* _m;
 103   bool _is_virtual;
 104  public:
 105   IntrinsicDescPair(ciMethod* m, bool is_virtual) : _m(m), _is_virtual(is_virtual) {}
 106   static int compare(IntrinsicDescPair* const& key, CallGenerator* const& elt) {
 107     ciMethod* m= elt->method();
 108     ciMethod* key_m = key->_m;
 109     if (key_m < m)      return -1;
 110     else if (key_m > m) return 1;
 111     else {
 112       bool is_virtual = elt->is_virtual();
 113       bool key_virtual = key->_is_virtual;
 114       if (key_virtual < is_virtual)      return -1;
 115       else if (key_virtual > is_virtual) return 1;
 116       else                               return 0;
 117     }
 118   }
 119 };
 120 int Compile::intrinsic_insertion_index(ciMethod* m, bool is_virtual, bool& found) {
 121 #ifdef ASSERT
 122   for (int i = 1; i < _intrinsics->length(); i++) {
 123     CallGenerator* cg1 = _intrinsics->at(i-1);
 124     CallGenerator* cg2 = _intrinsics->at(i);
 125     assert(cg1->method() != cg2->method()
 126            ? cg1->method()     < cg2->method()
 127            : cg1->is_virtual() < cg2->is_virtual(),
 128            "compiler intrinsics list must stay sorted");
 129   }
 130 #endif
 131   IntrinsicDescPair pair(m, is_virtual);
 132   return _intrinsics->find_sorted<IntrinsicDescPair*, IntrinsicDescPair::compare>(&pair, found);
 133 }
 134 
 135 void Compile::register_intrinsic(CallGenerator* cg) {
 136   if (_intrinsics == NULL) {
 137     _intrinsics = new (comp_arena())GrowableArray<CallGenerator*>(comp_arena(), 60, 0, NULL);
 138   }
 139   int len = _intrinsics->length();
 140   bool found = false;
 141   int index = intrinsic_insertion_index(cg->method(), cg->is_virtual(), found);
 142   assert(!found, "registering twice");
 143   _intrinsics->insert_before(index, cg);
 144   assert(find_intrinsic(cg->method(), cg->is_virtual()) == cg, "registration worked");
 145 }
 146 
 147 CallGenerator* Compile::find_intrinsic(ciMethod* m, bool is_virtual) {
 148   assert(m->is_loaded(), "don't try this on unloaded methods");
 149   if (_intrinsics != NULL) {
 150     bool found = false;
 151     int index = intrinsic_insertion_index(m, is_virtual, found);
 152      if (found) {
 153       return _intrinsics->at(index);
 154     }
 155   }
 156   // Lazily create intrinsics for intrinsic IDs well-known in the runtime.
 157   if (m->intrinsic_id() != vmIntrinsics::_none &&
 158       m->intrinsic_id() <= vmIntrinsics::LAST_COMPILER_INLINE) {
 159     CallGenerator* cg = make_vm_intrinsic(m, is_virtual);
 160     if (cg != NULL) {
 161       // Save it for next time:
 162       register_intrinsic(cg);
 163       return cg;
 164     } else {
 165       gather_intrinsic_statistics(m->intrinsic_id(), is_virtual, _intrinsic_disabled);
 166     }
 167   }
 168   return NULL;
 169 }
 170 
 171 // Compile:: register_library_intrinsics and make_vm_intrinsic are defined
 172 // in library_call.cpp.
 173 
 174 
 175 #ifndef PRODUCT
 176 // statistics gathering...
 177 
 178 juint  Compile::_intrinsic_hist_count[vmIntrinsics::ID_LIMIT] = {0};
 179 jubyte Compile::_intrinsic_hist_flags[vmIntrinsics::ID_LIMIT] = {0};
 180 
 181 bool Compile::gather_intrinsic_statistics(vmIntrinsics::ID id, bool is_virtual, int flags) {
 182   assert(id > vmIntrinsics::_none && id < vmIntrinsics::ID_LIMIT, "oob");
 183   int oflags = _intrinsic_hist_flags[id];
 184   assert(flags != 0, "what happened?");
 185   if (is_virtual) {
 186     flags |= _intrinsic_virtual;
 187   }
 188   bool changed = (flags != oflags);
 189   if ((flags & _intrinsic_worked) != 0) {
 190     juint count = (_intrinsic_hist_count[id] += 1);
 191     if (count == 1) {
 192       changed = true;           // first time
 193     }
 194     // increment the overall count also:
 195     _intrinsic_hist_count[vmIntrinsics::_none] += 1;
 196   }
 197   if (changed) {
 198     if (((oflags ^ flags) & _intrinsic_virtual) != 0) {
 199       // Something changed about the intrinsic's virtuality.
 200       if ((flags & _intrinsic_virtual) != 0) {
 201         // This is the first use of this intrinsic as a virtual call.
 202         if (oflags != 0) {
 203           // We already saw it as a non-virtual, so note both cases.
 204           flags |= _intrinsic_both;
 205         }
 206       } else if ((oflags & _intrinsic_both) == 0) {
 207         // This is the first use of this intrinsic as a non-virtual
 208         flags |= _intrinsic_both;
 209       }
 210     }
 211     _intrinsic_hist_flags[id] = (jubyte) (oflags | flags);
 212   }
 213   // update the overall flags also:
 214   _intrinsic_hist_flags[vmIntrinsics::_none] |= (jubyte) flags;
 215   return changed;
 216 }
 217 
 218 static char* format_flags(int flags, char* buf) {
 219   buf[0] = 0;
 220   if ((flags & Compile::_intrinsic_worked) != 0)    strcat(buf, ",worked");
 221   if ((flags & Compile::_intrinsic_failed) != 0)    strcat(buf, ",failed");
 222   if ((flags & Compile::_intrinsic_disabled) != 0)  strcat(buf, ",disabled");
 223   if ((flags & Compile::_intrinsic_virtual) != 0)   strcat(buf, ",virtual");
 224   if ((flags & Compile::_intrinsic_both) != 0)      strcat(buf, ",nonvirtual");
 225   if (buf[0] == 0)  strcat(buf, ",");
 226   assert(buf[0] == ',', "must be");
 227   return &buf[1];
 228 }
 229 
 230 void Compile::print_intrinsic_statistics() {
 231   char flagsbuf[100];
 232   ttyLocker ttyl;
 233   if (xtty != NULL)  xtty->head("statistics type='intrinsic'");
 234   tty->print_cr("Compiler intrinsic usage:");
 235   juint total = _intrinsic_hist_count[vmIntrinsics::_none];
 236   if (total == 0)  total = 1;  // avoid div0 in case of no successes
 237   #define PRINT_STAT_LINE(name, c, f) \
 238     tty->print_cr("  %4d (%4.1f%%) %s (%s)", (int)(c), ((c) * 100.0) / total, name, f);
 239   for (int index = 1 + (int)vmIntrinsics::_none; index < (int)vmIntrinsics::ID_LIMIT; index++) {
 240     vmIntrinsics::ID id = (vmIntrinsics::ID) index;
 241     int   flags = _intrinsic_hist_flags[id];
 242     juint count = _intrinsic_hist_count[id];
 243     if ((flags | count) != 0) {
 244       PRINT_STAT_LINE(vmIntrinsics::name_at(id), count, format_flags(flags, flagsbuf));
 245     }
 246   }
 247   PRINT_STAT_LINE("total", total, format_flags(_intrinsic_hist_flags[vmIntrinsics::_none], flagsbuf));
 248   if (xtty != NULL)  xtty->tail("statistics");
 249 }
 250 
 251 void Compile::print_statistics() {
 252   { ttyLocker ttyl;
 253     if (xtty != NULL)  xtty->head("statistics type='opto'");
 254     Parse::print_statistics();
 255     PhaseCCP::print_statistics();
 256     PhaseRegAlloc::print_statistics();
 257     Scheduling::print_statistics();
 258     PhasePeephole::print_statistics();
 259     PhaseIdealLoop::print_statistics();
 260     if (xtty != NULL)  xtty->tail("statistics");
 261   }
 262   if (_intrinsic_hist_flags[vmIntrinsics::_none] != 0) {
 263     // put this under its own <statistics> element.
 264     print_intrinsic_statistics();
 265   }
 266 }
 267 #endif //PRODUCT
 268 
 269 // Support for bundling info
 270 Bundle* Compile::node_bundling(const Node *n) {
 271   assert(valid_bundle_info(n), "oob");
 272   return &_node_bundling_base[n->_idx];
 273 }
 274 
 275 bool Compile::valid_bundle_info(const Node *n) {
 276   return (_node_bundling_limit > n->_idx);
 277 }
 278 
 279 
 280 void Compile::gvn_replace_by(Node* n, Node* nn) {
 281   for (DUIterator_Last imin, i = n->last_outs(imin); i >= imin; ) {
 282     Node* use = n->last_out(i);
 283     bool is_in_table = initial_gvn()->hash_delete(use);
 284     uint uses_found = 0;
 285     for (uint j = 0; j < use->len(); j++) {
 286       if (use->in(j) == n) {
 287         if (j < use->req())
 288           use->set_req(j, nn);
 289         else
 290           use->set_prec(j, nn);
 291         uses_found++;
 292       }
 293     }
 294     if (is_in_table) {
 295       // reinsert into table
 296       initial_gvn()->hash_find_insert(use);
 297     }
 298     record_for_igvn(use);
 299     i -= uses_found;    // we deleted 1 or more copies of this edge
 300   }
 301 }
 302 
 303 
 304 static inline bool not_a_node(const Node* n) {
 305   if (n == NULL)                   return true;
 306   if (((intptr_t)n & 1) != 0)      return true;  // uninitialized, etc.
 307   if (*(address*)n == badAddress)  return true;  // kill by Node::destruct
 308   return false;
 309 }
 310 
 311 // Identify all nodes that are reachable from below, useful.
 312 // Use breadth-first pass that records state in a Unique_Node_List,
 313 // recursive traversal is slower.
 314 void Compile::identify_useful_nodes(Unique_Node_List &useful) {
 315   int estimated_worklist_size = live_nodes();
 316   useful.map( estimated_worklist_size, NULL );  // preallocate space
 317 
 318   // Initialize worklist
 319   if (root() != NULL)     { useful.push(root()); }
 320   // If 'top' is cached, declare it useful to preserve cached node
 321   if( cached_top_node() ) { useful.push(cached_top_node()); }
 322 
 323   // Push all useful nodes onto the list, breadthfirst
 324   for( uint next = 0; next < useful.size(); ++next ) {
 325     assert( next < unique(), "Unique useful nodes < total nodes");
 326     Node *n  = useful.at(next);
 327     uint max = n->len();
 328     for( uint i = 0; i < max; ++i ) {
 329       Node *m = n->in(i);
 330       if (not_a_node(m))  continue;
 331       useful.push(m);
 332     }
 333   }
 334 }
 335 
 336 // Update dead_node_list with any missing dead nodes using useful
 337 // list. Consider all non-useful nodes to be useless i.e., dead nodes.
 338 void Compile::update_dead_node_list(Unique_Node_List &useful) {
 339   uint max_idx = unique();
 340   VectorSet& useful_node_set = useful.member_set();
 341 
 342   for (uint node_idx = 0; node_idx < max_idx; node_idx++) {
 343     // If node with index node_idx is not in useful set,
 344     // mark it as dead in dead node list.
 345     if (! useful_node_set.test(node_idx) ) {
 346       record_dead_node(node_idx);
 347     }
 348   }
 349 }
 350 
 351 void Compile::remove_useless_late_inlines(GrowableArray<CallGenerator*>* inlines, Unique_Node_List &useful) {
 352   int shift = 0;
 353   for (int i = 0; i < inlines->length(); i++) {
 354     CallGenerator* cg = inlines->at(i);
 355     CallNode* call = cg->call_node();
 356     if (shift > 0) {
 357       inlines->at_put(i-shift, cg);
 358     }
 359     if (!useful.member(call)) {
 360       shift++;
 361     }
 362   }
 363   inlines->trunc_to(inlines->length()-shift);
 364 }
 365 
 366 // Disconnect all useless nodes by disconnecting those at the boundary.
 367 void Compile::remove_useless_nodes(Unique_Node_List &useful) {
 368   uint next = 0;
 369   while (next < useful.size()) {
 370     Node *n = useful.at(next++);
 371     if (n->is_SafePoint()) {
 372       // We're done with a parsing phase. Replaced nodes are not valid
 373       // beyond that point.
 374       n->as_SafePoint()->delete_replaced_nodes();
 375     }
 376     // Use raw traversal of out edges since this code removes out edges
 377     int max = n->outcnt();
 378     for (int j = 0; j < max; ++j) {
 379       Node* child = n->raw_out(j);
 380       if (! useful.member(child)) {
 381         assert(!child->is_top() || child != top(),
 382                "If top is cached in Compile object it is in useful list");
 383         // Only need to remove this out-edge to the useless node
 384         n->raw_del_out(j);
 385         --j;
 386         --max;
 387       }
 388     }
 389     if (n->outcnt() == 1 && n->has_special_unique_user()) {
 390       record_for_igvn(n->unique_out());
 391     }
 392   }
 393   // Remove useless macro and predicate opaq nodes
 394   for (int i = C->macro_count()-1; i >= 0; i--) {
 395     Node* n = C->macro_node(i);
 396     if (!useful.member(n)) {
 397       remove_macro_node(n);
 398     }
 399   }
 400   // Remove useless CastII nodes with range check dependency
 401   for (int i = range_check_cast_count() - 1; i >= 0; i--) {
 402     Node* cast = range_check_cast_node(i);
 403     if (!useful.member(cast)) {
 404       remove_range_check_cast(cast);
 405     }
 406   }
 407   // Remove useless expensive nodes
 408   for (int i = C->expensive_count()-1; i >= 0; i--) {
 409     Node* n = C->expensive_node(i);
 410     if (!useful.member(n)) {
 411       remove_expensive_node(n);
 412     }
 413   }
 414   // Remove useless Opaque4 nodes
 415   for (int i = opaque4_count() - 1; i >= 0; i--) {
 416     Node* opaq = opaque4_node(i);
 417     if (!useful.member(opaq)) {
 418       remove_opaque4_node(opaq);
 419     }
 420   }
 421   // Remove useless value type nodes
 422   if (_value_type_nodes != NULL) {
 423     _value_type_nodes->remove_useless_nodes(useful.member_set());
 424   }
 425   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 426   bs->eliminate_useless_gc_barriers(useful, this);
 427   // clean up the late inline lists
 428   remove_useless_late_inlines(&_string_late_inlines, useful);
 429   remove_useless_late_inlines(&_boxing_late_inlines, useful);
 430   remove_useless_late_inlines(&_late_inlines, useful);
 431   debug_only(verify_graph_edges(true/*check for no_dead_code*/);)
 432 }
 433 
 434 //------------------------------frame_size_in_words-----------------------------
 435 // frame_slots in units of words
 436 int Compile::frame_size_in_words() const {
 437   // shift is 0 in LP32 and 1 in LP64
 438   const int shift = (LogBytesPerWord - LogBytesPerInt);
 439   int words = _frame_slots >> shift;
 440   assert( words << shift == _frame_slots, "frame size must be properly aligned in LP64" );
 441   return words;
 442 }
 443 
 444 // To bang the stack of this compiled method we use the stack size
 445 // that the interpreter would need in case of a deoptimization. This
 446 // removes the need to bang the stack in the deoptimization blob which
 447 // in turn simplifies stack overflow handling.
 448 int Compile::bang_size_in_bytes() const {
 449   return MAX2(frame_size_in_bytes() + os::extra_bang_size_in_bytes(), _interpreter_frame_size);
 450 }
 451 
 452 // ============================================================================
 453 //------------------------------CompileWrapper---------------------------------
 454 class CompileWrapper : public StackObj {
 455   Compile *const _compile;
 456  public:
 457   CompileWrapper(Compile* compile);
 458 
 459   ~CompileWrapper();
 460 };
 461 
 462 CompileWrapper::CompileWrapper(Compile* compile) : _compile(compile) {
 463   // the Compile* pointer is stored in the current ciEnv:
 464   ciEnv* env = compile->env();
 465   assert(env == ciEnv::current(), "must already be a ciEnv active");
 466   assert(env->compiler_data() == NULL, "compile already active?");
 467   env->set_compiler_data(compile);
 468   assert(compile == Compile::current(), "sanity");
 469 
 470   compile->set_type_dict(NULL);
 471   compile->set_clone_map(new Dict(cmpkey, hashkey, _compile->comp_arena()));
 472   compile->clone_map().set_clone_idx(0);
 473   compile->set_type_last_size(0);
 474   compile->set_last_tf(NULL, NULL);
 475   compile->set_indexSet_arena(NULL);
 476   compile->set_indexSet_free_block_list(NULL);
 477   compile->init_type_arena();
 478   Type::Initialize(compile);
 479   _compile->set_scratch_buffer_blob(NULL);
 480   _compile->begin_method();
 481   _compile->clone_map().set_debug(_compile->has_method() && _compile->directive()->CloneMapDebugOption);
 482 }
 483 CompileWrapper::~CompileWrapper() {
 484   _compile->end_method();
 485   if (_compile->scratch_buffer_blob() != NULL)
 486     BufferBlob::free(_compile->scratch_buffer_blob());
 487   _compile->env()->set_compiler_data(NULL);
 488 }
 489 
 490 
 491 //----------------------------print_compile_messages---------------------------
 492 void Compile::print_compile_messages() {
 493 #ifndef PRODUCT
 494   // Check if recompiling
 495   if (_subsume_loads == false && PrintOpto) {
 496     // Recompiling without allowing machine instructions to subsume loads
 497     tty->print_cr("*********************************************************");
 498     tty->print_cr("** Bailout: Recompile without subsuming loads          **");
 499     tty->print_cr("*********************************************************");
 500   }
 501   if (_do_escape_analysis != DoEscapeAnalysis && PrintOpto) {
 502     // Recompiling without escape analysis
 503     tty->print_cr("*********************************************************");
 504     tty->print_cr("** Bailout: Recompile without escape analysis          **");
 505     tty->print_cr("*********************************************************");
 506   }
 507   if (_eliminate_boxing != EliminateAutoBox && PrintOpto) {
 508     // Recompiling without boxing elimination
 509     tty->print_cr("*********************************************************");
 510     tty->print_cr("** Bailout: Recompile without boxing elimination       **");
 511     tty->print_cr("*********************************************************");
 512   }
 513   if (C->directive()->BreakAtCompileOption) {
 514     // Open the debugger when compiling this method.
 515     tty->print("### Breaking when compiling: ");
 516     method()->print_short_name();
 517     tty->cr();
 518     BREAKPOINT;
 519   }
 520 
 521   if( PrintOpto ) {
 522     if (is_osr_compilation()) {
 523       tty->print("[OSR]%3d", _compile_id);
 524     } else {
 525       tty->print("%3d", _compile_id);
 526     }
 527   }
 528 #endif
 529 }
 530 
 531 
 532 //-----------------------init_scratch_buffer_blob------------------------------
 533 // Construct a temporary BufferBlob and cache it for this compile.
 534 void Compile::init_scratch_buffer_blob(int const_size) {
 535   // If there is already a scratch buffer blob allocated and the
 536   // constant section is big enough, use it.  Otherwise free the
 537   // current and allocate a new one.
 538   BufferBlob* blob = scratch_buffer_blob();
 539   if ((blob != NULL) && (const_size <= _scratch_const_size)) {
 540     // Use the current blob.
 541   } else {
 542     if (blob != NULL) {
 543       BufferBlob::free(blob);
 544     }
 545 
 546     ResourceMark rm;
 547     _scratch_const_size = const_size;
 548     int size = C2Compiler::initial_code_buffer_size(const_size);
 549 #ifdef ASSERT
 550     if (C->has_scalarized_args()) {
 551       // Oop verification for loading object fields from scalarized value types in the new entry point requires lots of space
 552       size += 5120;
 553     }
 554 #endif
 555     blob = BufferBlob::create("Compile::scratch_buffer", size);
 556     // Record the buffer blob for next time.
 557     set_scratch_buffer_blob(blob);
 558     // Have we run out of code space?
 559     if (scratch_buffer_blob() == NULL) {
 560       // Let CompilerBroker disable further compilations.
 561       record_failure("Not enough space for scratch buffer in CodeCache");
 562       return;
 563     }
 564   }
 565 
 566   // Initialize the relocation buffers
 567   relocInfo* locs_buf = (relocInfo*) blob->content_end() - MAX_locs_size;
 568   set_scratch_locs_memory(locs_buf);
 569 }
 570 
 571 
 572 //-----------------------scratch_emit_size-------------------------------------
 573 // Helper function that computes size by emitting code
 574 uint Compile::scratch_emit_size(const Node* n) {
 575   // Start scratch_emit_size section.
 576   set_in_scratch_emit_size(true);
 577 
 578   // Emit into a trash buffer and count bytes emitted.
 579   // This is a pretty expensive way to compute a size,
 580   // but it works well enough if seldom used.
 581   // All common fixed-size instructions are given a size
 582   // method by the AD file.
 583   // Note that the scratch buffer blob and locs memory are
 584   // allocated at the beginning of the compile task, and
 585   // may be shared by several calls to scratch_emit_size.
 586   // The allocation of the scratch buffer blob is particularly
 587   // expensive, since it has to grab the code cache lock.
 588   BufferBlob* blob = this->scratch_buffer_blob();
 589   assert(blob != NULL, "Initialize BufferBlob at start");
 590   assert(blob->size() > MAX_inst_size, "sanity");
 591   relocInfo* locs_buf = scratch_locs_memory();
 592   address blob_begin = blob->content_begin();
 593   address blob_end   = (address)locs_buf;
 594   assert(blob->contains(blob_end), "sanity");
 595   CodeBuffer buf(blob_begin, blob_end - blob_begin);
 596   buf.initialize_consts_size(_scratch_const_size);
 597   buf.initialize_stubs_size(MAX_stubs_size);
 598   assert(locs_buf != NULL, "sanity");
 599   int lsize = MAX_locs_size / 3;
 600   buf.consts()->initialize_shared_locs(&locs_buf[lsize * 0], lsize);
 601   buf.insts()->initialize_shared_locs( &locs_buf[lsize * 1], lsize);
 602   buf.stubs()->initialize_shared_locs( &locs_buf[lsize * 2], lsize);
 603   // Mark as scratch buffer.
 604   buf.consts()->set_scratch_emit();
 605   buf.insts()->set_scratch_emit();
 606   buf.stubs()->set_scratch_emit();
 607 
 608   // Do the emission.
 609 
 610   Label fakeL; // Fake label for branch instructions.
 611   Label*   saveL = NULL;
 612   uint save_bnum = 0;
 613   bool is_branch = n->is_MachBranch();
 614   if (is_branch) {
 615     MacroAssembler masm(&buf);
 616     masm.bind(fakeL);
 617     n->as_MachBranch()->save_label(&saveL, &save_bnum);
 618     n->as_MachBranch()->label_set(&fakeL, 0);
 619   } else if (n->is_MachProlog()) {
 620     saveL = ((MachPrologNode*)n)->_verified_entry;
 621     ((MachPrologNode*)n)->_verified_entry = &fakeL;
 622   }
 623   n->emit(buf, this->regalloc());
 624 
 625   // Emitting into the scratch buffer should not fail
 626   assert (!failing(), "Must not have pending failure. Reason is: %s", failure_reason());
 627 
 628   // Restore label.
 629   if (is_branch) {
 630     n->as_MachBranch()->label_set(saveL, save_bnum);
 631   } else if (n->is_MachProlog()) {
 632     ((MachPrologNode*)n)->_verified_entry = saveL;
 633   }
 634 
 635   // End scratch_emit_size section.
 636   set_in_scratch_emit_size(false);
 637 
 638   return buf.insts_size();
 639 }
 640 
 641 
 642 // ============================================================================
 643 //------------------------------Compile standard-------------------------------
 644 debug_only( int Compile::_debug_idx = 100000; )
 645 
 646 // Compile a method.  entry_bci is -1 for normal compilations and indicates
 647 // the continuation bci for on stack replacement.
 648 
 649 
 650 Compile::Compile( ciEnv* ci_env, C2Compiler* compiler, ciMethod* target, int osr_bci,
 651                   bool subsume_loads, bool do_escape_analysis, bool eliminate_boxing, DirectiveSet* directive)
 652                 : Phase(Compiler),
 653                   _compile_id(ci_env->compile_id()),
 654                   _save_argument_registers(false),
 655                   _subsume_loads(subsume_loads),
 656                   _do_escape_analysis(do_escape_analysis),
 657                   _eliminate_boxing(eliminate_boxing),
 658                   _method(target),
 659                   _entry_bci(osr_bci),
 660                   _stub_function(NULL),
 661                   _stub_name(NULL),
 662                   _stub_entry_point(NULL),
 663                   _max_node_limit(MaxNodeLimit),
 664                   _orig_pc_slot(0),
 665                   _orig_pc_slot_offset_in_bytes(0),
 666                   _sp_inc_slot(0),
 667                   _sp_inc_slot_offset_in_bytes(0),
 668                   _inlining_progress(false),
 669                   _inlining_incrementally(false),
 670                   _do_cleanup(false),
 671                   _has_reserved_stack_access(target->has_reserved_stack_access()),
 672 #ifndef PRODUCT
 673                   _trace_opto_output(directive->TraceOptoOutputOption),
 674 #endif
 675                   _has_method_handle_invokes(false),
 676                   _clinit_barrier_on_entry(false),
 677                   _comp_arena(mtCompiler),
 678                   _barrier_set_state(BarrierSet::barrier_set()->barrier_set_c2()->create_barrier_state(comp_arena())),
 679                   _env(ci_env),
 680                   _directive(directive),
 681                   _log(ci_env->log()),
 682                   _failure_reason(NULL),
 683                   _congraph(NULL),
 684 #ifndef PRODUCT
 685                   _printer(IdealGraphPrinter::printer()),
 686 #endif
 687                   _dead_node_list(comp_arena()),
 688                   _dead_node_count(0),
 689                   _node_arena(mtCompiler),
 690                   _old_arena(mtCompiler),
 691                   _mach_constant_base_node(NULL),
 692                   _Compile_types(mtCompiler),
 693                   _initial_gvn(NULL),
 694                   _for_igvn(NULL),
 695                   _warm_calls(NULL),
 696                   _late_inlines(comp_arena(), 2, 0, NULL),
 697                   _string_late_inlines(comp_arena(), 2, 0, NULL),
 698                   _boxing_late_inlines(comp_arena(), 2, 0, NULL),
 699                   _late_inlines_pos(0),
 700                   _number_of_mh_late_inlines(0),
 701                   _print_inlining_stream(NULL),
 702                   _print_inlining_list(NULL),
 703                   _print_inlining_idx(0),
 704                   _print_inlining_output(NULL),
 705                   _replay_inline_data(NULL),
 706                   _java_calls(0),
 707                   _inner_loops(0),
 708                   _interpreter_frame_size(0),
 709                   _node_bundling_limit(0),
 710                   _node_bundling_base(NULL),
 711                   _code_buffer("Compile::Fill_buffer"),
 712                   _scratch_const_size(-1),
 713                   _in_scratch_emit_size(false)
 714 #ifndef PRODUCT
 715                   , _in_dump_cnt(0)
 716 #endif
 717 {
 718   C = this;
 719 #ifndef PRODUCT
 720   if (_printer != NULL) {
 721     _printer->set_compile(this);
 722   }
 723 #endif
 724   CompileWrapper cw(this);
 725 
 726   if (CITimeVerbose) {
 727     tty->print(" ");
 728     target->holder()->name()->print();
 729     tty->print(".");
 730     target->print_short_name();
 731     tty->print("  ");
 732   }
 733   TraceTime t1("Total compilation time", &_t_totalCompilation, CITime, CITimeVerbose);
 734   TraceTime t2(NULL, &_t_methodCompilation, CITime, false);
 735 
 736 #if defined(SUPPORT_ASSEMBLY) || defined(SUPPORT_ABSTRACT_ASSEMBLY)
 737   bool print_opto_assembly = directive->PrintOptoAssemblyOption;
 738   // We can always print a disassembly, either abstract (hex dump) or
 739   // with the help of a suitable hsdis library. Thus, we should not
 740   // couple print_assembly and print_opto_assembly controls.
 741   // But: always print opto and regular assembly on compile command 'print'.
 742   bool print_assembly = directive->PrintAssemblyOption;
 743   set_print_assembly(print_opto_assembly || print_assembly);
 744 #else
 745   set_print_assembly(false); // must initialize.
 746 #endif
 747 
 748 #ifndef PRODUCT
 749   set_parsed_irreducible_loop(false);
 750 
 751   if (directive->ReplayInlineOption) {
 752     _replay_inline_data = ciReplay::load_inline_data(method(), entry_bci(), ci_env->comp_level());
 753   }
 754 #endif
 755   set_print_inlining(directive->PrintInliningOption || PrintOptoInlining);
 756   set_print_intrinsics(directive->PrintIntrinsicsOption);
 757   set_has_irreducible_loop(true); // conservative until build_loop_tree() reset it
 758 
 759   if (ProfileTraps RTM_OPT_ONLY( || UseRTMLocking )) {
 760     // Make sure the method being compiled gets its own MDO,
 761     // so we can at least track the decompile_count().
 762     // Need MDO to record RTM code generation state.
 763     method()->ensure_method_data();
 764   }
 765 
 766   Init(::AliasLevel);
 767 
 768 
 769   print_compile_messages();
 770 
 771   _ilt = InlineTree::build_inline_tree_root();
 772 
 773   // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
 774   assert(num_alias_types() >= AliasIdxRaw, "");
 775 
 776 #define MINIMUM_NODE_HASH  1023
 777   // Node list that Iterative GVN will start with
 778   Unique_Node_List for_igvn(comp_arena());
 779   set_for_igvn(&for_igvn);
 780 
 781   // GVN that will be run immediately on new nodes
 782   uint estimated_size = method()->code_size()*4+64;
 783   estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
 784   PhaseGVN gvn(node_arena(), estimated_size);
 785   set_initial_gvn(&gvn);
 786 
 787   print_inlining_init();
 788   { // Scope for timing the parser
 789     TracePhase tp("parse", &timers[_t_parser]);
 790 
 791     // Put top into the hash table ASAP.
 792     initial_gvn()->transform_no_reclaim(top());
 793 
 794     // Set up tf(), start(), and find a CallGenerator.
 795     CallGenerator* cg = NULL;
 796     if (is_osr_compilation()) {
 797       init_tf(TypeFunc::make(method(), /* is_osr_compilation = */ true));
 798       StartNode* s = new StartOSRNode(root(), tf()->domain_sig());
 799       initial_gvn()->set_type_bottom(s);
 800       init_start(s);
 801       cg = CallGenerator::for_osr(method(), entry_bci());
 802     } else {
 803       // Normal case.
 804       init_tf(TypeFunc::make(method()));
 805       StartNode* s = new StartNode(root(), tf()->domain_cc());
 806       initial_gvn()->set_type_bottom(s);
 807       init_start(s);
 808       if (method()->intrinsic_id() == vmIntrinsics::_Reference_get) {
 809         // With java.lang.ref.reference.get() we must go through the
 810         // intrinsic - even when get() is the root
 811         // method of the compile - so that, if necessary, the value in
 812         // the referent field of the reference object gets recorded by
 813         // the pre-barrier code.
 814         cg = find_intrinsic(method(), false);
 815       }
 816       if (cg == NULL) {
 817         float past_uses = method()->interpreter_invocation_count();
 818         float expected_uses = past_uses;
 819         cg = CallGenerator::for_inline(method(), expected_uses);
 820       }
 821     }
 822     if (failing())  return;
 823     if (cg == NULL) {
 824       record_method_not_compilable("cannot parse method");
 825       return;
 826     }
 827     JVMState* jvms = build_start_state(start(), tf());
 828     if ((jvms = cg->generate(jvms)) == NULL) {
 829       if (!failure_reason_is(C2Compiler::retry_class_loading_during_parsing())) {
 830         record_method_not_compilable("method parse failed");
 831       }
 832       return;
 833     }
 834     GraphKit kit(jvms);
 835 
 836     if (!kit.stopped()) {
 837       // Accept return values, and transfer control we know not where.
 838       // This is done by a special, unique ReturnNode bound to root.
 839       return_values(kit.jvms());
 840     }
 841 
 842     if (kit.has_exceptions()) {
 843       // Any exceptions that escape from this call must be rethrown
 844       // to whatever caller is dynamically above us on the stack.
 845       // This is done by a special, unique RethrowNode bound to root.
 846       rethrow_exceptions(kit.transfer_exceptions_into_jvms());
 847     }
 848 
 849     assert(IncrementalInline || (_late_inlines.length() == 0 && !has_mh_late_inlines()), "incremental inlining is off");
 850 
 851     if (_late_inlines.length() == 0 && !has_mh_late_inlines() && !failing() && has_stringbuilder()) {
 852       inline_string_calls(true);
 853     }
 854 
 855     if (failing())  return;
 856 
 857     print_method(PHASE_BEFORE_REMOVEUSELESS, 3);
 858 
 859     // Remove clutter produced by parsing.
 860     if (!failing()) {
 861       ResourceMark rm;
 862       PhaseRemoveUseless pru(initial_gvn(), &for_igvn);
 863     }
 864   }
 865 
 866   // Note:  Large methods are capped off in do_one_bytecode().
 867   if (failing())  return;
 868 
 869   // After parsing, node notes are no longer automagic.
 870   // They must be propagated by register_new_node_with_optimizer(),
 871   // clone(), or the like.
 872   set_default_node_notes(NULL);
 873 
 874   for (;;) {
 875     int successes = Inline_Warm();
 876     if (failing())  return;
 877     if (successes == 0)  break;
 878   }
 879 
 880   // Drain the list.
 881   Finish_Warm();
 882 #ifndef PRODUCT
 883   if (_printer && _printer->should_print(1)) {
 884     _printer->print_inlining();
 885   }
 886 #endif
 887 
 888   if (failing())  return;
 889   NOT_PRODUCT( verify_graph_edges(); )
 890 
 891   // Now optimize
 892   Optimize();
 893   if (failing())  return;
 894   NOT_PRODUCT( verify_graph_edges(); )
 895 
 896 #ifndef PRODUCT
 897   if (PrintIdeal) {
 898     ttyLocker ttyl;  // keep the following output all in one block
 899     // This output goes directly to the tty, not the compiler log.
 900     // To enable tools to match it up with the compilation activity,
 901     // be sure to tag this tty output with the compile ID.
 902     if (xtty != NULL) {
 903       xtty->head("ideal compile_id='%d'%s", compile_id(),
 904                  is_osr_compilation()    ? " compile_kind='osr'" :
 905                  "");
 906     }
 907     root()->dump(9999);
 908     if (xtty != NULL) {
 909       xtty->tail("ideal");
 910     }
 911   }
 912 #endif
 913 
 914 #ifdef ASSERT
 915   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 916   bs->verify_gc_barriers(this, BarrierSetC2::BeforeCodeGen);
 917 #endif
 918 
 919   // Dump compilation data to replay it.
 920   if (directive->DumpReplayOption) {
 921     env()->dump_replay_data(_compile_id);
 922   }
 923   if (directive->DumpInlineOption && (ilt() != NULL)) {
 924     env()->dump_inline_data(_compile_id);
 925   }
 926 
 927   // Now that we know the size of all the monitors we can add a fixed slot
 928   // for the original deopt pc.
 929 
 930   _orig_pc_slot = fixed_slots();
 931   int next_slot = _orig_pc_slot + (sizeof(address) / VMRegImpl::stack_slot_size);
 932 
 933   if (needs_stack_repair()) {
 934     // One extra slot for the special stack increment value
 935     _sp_inc_slot = next_slot;
 936     next_slot += 2;
 937   }
 938 
 939   set_fixed_slots(next_slot);
 940 
 941   // Compute when to use implicit null checks. Used by matching trap based
 942   // nodes and NullCheck optimization.
 943   set_allowed_deopt_reasons();
 944 
 945   // Now generate code
 946   Code_Gen();
 947   if (failing())  return;
 948 
 949   // Check if we want to skip execution of all compiled code.
 950   {
 951 #ifndef PRODUCT
 952     if (OptoNoExecute) {
 953       record_method_not_compilable("+OptoNoExecute");  // Flag as failed
 954       return;
 955     }
 956 #endif
 957     TracePhase tp("install_code", &timers[_t_registerMethod]);
 958 
 959     if (is_osr_compilation()) {
 960       _code_offsets.set_value(CodeOffsets::Verified_Entry, 0);
 961       _code_offsets.set_value(CodeOffsets::OSR_Entry, _first_block_size);
 962     } else {
 963       _code_offsets.set_value(CodeOffsets::Verified_Entry, _first_block_size);
 964       if (_code_offsets.value(CodeOffsets::Verified_Value_Entry) == -1) {
 965         _code_offsets.set_value(CodeOffsets::Verified_Value_Entry, _first_block_size);
 966       }
 967       if (_code_offsets.value(CodeOffsets::Verified_Value_Entry_RO) == -1) {
 968         _code_offsets.set_value(CodeOffsets::Verified_Value_Entry_RO, _first_block_size);
 969       }
 970       if (_code_offsets.value(CodeOffsets::Entry) == -1) {
 971         _code_offsets.set_value(CodeOffsets::Entry, _first_block_size);
 972       }
 973       _code_offsets.set_value(CodeOffsets::OSR_Entry, 0);
 974     }
 975 
 976     env()->register_method(_method, _entry_bci,
 977                            &_code_offsets,
 978                            _orig_pc_slot_offset_in_bytes,
 979                            code_buffer(),
 980                            frame_size_in_words(), _oop_map_set,
 981                            &_handler_table, &_inc_table,
 982                            compiler,
 983                            has_unsafe_access(),
 984                            SharedRuntime::is_wide_vector(max_vector_size()),
 985                            rtm_state()
 986                            );
 987 
 988     if (log() != NULL) // Print code cache state into compiler log
 989       log()->code_cache_state();
 990   }
 991 }
 992 
 993 //------------------------------Compile----------------------------------------
 994 // Compile a runtime stub
 995 Compile::Compile( ciEnv* ci_env,
 996                   TypeFunc_generator generator,
 997                   address stub_function,
 998                   const char *stub_name,
 999                   int is_fancy_jump,
1000                   bool pass_tls,
1001                   bool save_arg_registers,
1002                   bool return_pc,
1003                   DirectiveSet* directive)
1004   : Phase(Compiler),
1005     _compile_id(0),
1006     _save_argument_registers(save_arg_registers),
1007     _subsume_loads(true),
1008     _do_escape_analysis(false),
1009     _eliminate_boxing(false),
1010     _method(NULL),
1011     _entry_bci(InvocationEntryBci),
1012     _stub_function(stub_function),
1013     _stub_name(stub_name),
1014     _stub_entry_point(NULL),
1015     _max_node_limit(MaxNodeLimit),
1016     _orig_pc_slot(0),
1017     _orig_pc_slot_offset_in_bytes(0),
1018     _sp_inc_slot(0),
1019     _sp_inc_slot_offset_in_bytes(0),
1020     _inlining_progress(false),
1021     _inlining_incrementally(false),
1022     _has_reserved_stack_access(false),
1023 #ifndef PRODUCT
1024     _trace_opto_output(directive->TraceOptoOutputOption),
1025 #endif
1026     _has_method_handle_invokes(false),
1027     _clinit_barrier_on_entry(false),
1028     _comp_arena(mtCompiler),
1029     _env(ci_env),
1030     _directive(directive),
1031     _log(ci_env->log()),
1032     _failure_reason(NULL),
1033     _congraph(NULL),
1034 #ifndef PRODUCT
1035     _printer(NULL),
1036 #endif
1037     _dead_node_list(comp_arena()),
1038     _dead_node_count(0),
1039     _node_arena(mtCompiler),
1040     _old_arena(mtCompiler),
1041     _mach_constant_base_node(NULL),
1042     _Compile_types(mtCompiler),
1043     _initial_gvn(NULL),
1044     _for_igvn(NULL),
1045     _warm_calls(NULL),
1046     _number_of_mh_late_inlines(0),
1047     _print_inlining_stream(NULL),
1048     _print_inlining_list(NULL),
1049     _print_inlining_idx(0),
1050     _print_inlining_output(NULL),
1051     _replay_inline_data(NULL),
1052     _java_calls(0),
1053     _inner_loops(0),
1054     _interpreter_frame_size(0),
1055     _node_bundling_limit(0),
1056     _node_bundling_base(NULL),
1057     _code_buffer("Compile::Fill_buffer"),
1058 #ifndef PRODUCT
1059     _in_dump_cnt(0),
1060 #endif
1061     _allowed_reasons(0) {
1062   C = this;
1063 
1064   TraceTime t1(NULL, &_t_totalCompilation, CITime, false);
1065   TraceTime t2(NULL, &_t_stubCompilation, CITime, false);
1066 
1067 #ifndef PRODUCT
1068   set_print_assembly(PrintFrameConverterAssembly);
1069   set_parsed_irreducible_loop(false);
1070 #else
1071   set_print_assembly(false); // Must initialize.
1072 #endif
1073   set_has_irreducible_loop(false); // no loops
1074 
1075   CompileWrapper cw(this);
1076   Init(/*AliasLevel=*/ 0);
1077   init_tf((*generator)());
1078 
1079   {
1080     // The following is a dummy for the sake of GraphKit::gen_stub
1081     Unique_Node_List for_igvn(comp_arena());
1082     set_for_igvn(&for_igvn);  // not used, but some GraphKit guys push on this
1083     PhaseGVN gvn(Thread::current()->resource_area(),255);
1084     set_initial_gvn(&gvn);    // not significant, but GraphKit guys use it pervasively
1085     gvn.transform_no_reclaim(top());
1086 
1087     GraphKit kit;
1088     kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
1089   }
1090 
1091   NOT_PRODUCT( verify_graph_edges(); )
1092   Code_Gen();
1093   if (failing())  return;
1094 
1095 
1096   // Entry point will be accessed using compile->stub_entry_point();
1097   if (code_buffer() == NULL) {
1098     Matcher::soft_match_failure();
1099   } else {
1100     if (PrintAssembly && (WizardMode || Verbose))
1101       tty->print_cr("### Stub::%s", stub_name);
1102 
1103     if (!failing()) {
1104       assert(_fixed_slots == 0, "no fixed slots used for runtime stubs");
1105 
1106       // Make the NMethod
1107       // For now we mark the frame as never safe for profile stackwalking
1108       RuntimeStub *rs = RuntimeStub::new_runtime_stub(stub_name,
1109                                                       code_buffer(),
1110                                                       CodeOffsets::frame_never_safe,
1111                                                       // _code_offsets.value(CodeOffsets::Frame_Complete),
1112                                                       frame_size_in_words(),
1113                                                       _oop_map_set,
1114                                                       save_arg_registers);
1115       assert(rs != NULL && rs->is_runtime_stub(), "sanity check");
1116 
1117       _stub_entry_point = rs->entry_point();
1118     }
1119   }
1120 }
1121 
1122 //------------------------------Init-------------------------------------------
1123 // Prepare for a single compilation
1124 void Compile::Init(int aliaslevel) {
1125   _unique  = 0;
1126   _regalloc = NULL;
1127 
1128   _tf      = NULL;  // filled in later
1129   _top     = NULL;  // cached later
1130   _matcher = NULL;  // filled in later
1131   _cfg     = NULL;  // filled in later
1132 
1133   set_24_bit_selection_and_mode(Use24BitFP, false);
1134 
1135   _node_note_array = NULL;
1136   _default_node_notes = NULL;
1137   DEBUG_ONLY( _modified_nodes = NULL; ) // Used in Optimize()
1138 
1139   _immutable_memory = NULL; // filled in at first inquiry
1140 
1141   // Globally visible Nodes
1142   // First set TOP to NULL to give safe behavior during creation of RootNode
1143   set_cached_top_node(NULL);
1144   set_root(new RootNode());
1145   // Now that you have a Root to point to, create the real TOP
1146   set_cached_top_node( new ConNode(Type::TOP) );
1147   set_recent_alloc(NULL, NULL);
1148 
1149   // Create Debug Information Recorder to record scopes, oopmaps, etc.
1150   env()->set_oop_recorder(new OopRecorder(env()->arena()));
1151   env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
1152   env()->set_dependencies(new Dependencies(env()));
1153 
1154   _fixed_slots = 0;
1155   set_has_split_ifs(false);
1156   set_has_loops(has_method() && method()->has_loops()); // first approximation
1157   set_has_stringbuilder(false);
1158   set_has_boxed_value(false);
1159   _trap_can_recompile = false;  // no traps emitted yet
1160   _major_progress = true; // start out assuming good things will happen
1161   set_has_unsafe_access(false);
1162   set_max_vector_size(0);
1163   set_clear_upper_avx(false);  //false as default for clear upper bits of ymm registers
1164   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
1165   set_decompile_count(0);
1166 
1167   set_do_freq_based_layout(_directive->BlockLayoutByFrequencyOption);
1168   _loop_opts_cnt = LoopOptsCount;
1169   _has_flattened_accesses = false;
1170   _flattened_accesses_share_alias = true;
1171 
1172   set_do_inlining(Inline);
1173   set_max_inline_size(MaxInlineSize);
1174   set_freq_inline_size(FreqInlineSize);
1175   set_do_scheduling(OptoScheduling);
1176   set_do_count_invocations(false);
1177   set_do_method_data_update(false);
1178 
1179   set_do_vector_loop(false);
1180 
1181   if (AllowVectorizeOnDemand) {
1182     if (has_method() && (_directive->VectorizeOption || _directive->VectorizeDebugOption)) {
1183       set_do_vector_loop(true);
1184       NOT_PRODUCT(if (do_vector_loop() && Verbose) {tty->print("Compile::Init: do vectorized loops (SIMD like) for method %s\n",  method()->name()->as_quoted_ascii());})
1185     } else if (has_method() && method()->name() != 0 &&
1186                method()->intrinsic_id() == vmIntrinsics::_forEachRemaining) {
1187       set_do_vector_loop(true);
1188     }
1189   }
1190   set_use_cmove(UseCMoveUnconditionally /* || do_vector_loop()*/); //TODO: consider do_vector_loop() mandate use_cmove unconditionally
1191   NOT_PRODUCT(if (use_cmove() && Verbose && has_method()) {tty->print("Compile::Init: use CMove without profitability tests for method %s\n",  method()->name()->as_quoted_ascii());})
1192 
1193   set_age_code(has_method() && method()->profile_aging());
1194   set_rtm_state(NoRTM); // No RTM lock eliding by default
1195   _max_node_limit = _directive->MaxNodeLimitOption;
1196 
1197 #if INCLUDE_RTM_OPT
1198   if (UseRTMLocking && has_method() && (method()->method_data_or_null() != NULL)) {
1199     int rtm_state = method()->method_data()->rtm_state();
1200     if (method_has_option("NoRTMLockEliding") || ((rtm_state & NoRTM) != 0)) {
1201       // Don't generate RTM lock eliding code.
1202       set_rtm_state(NoRTM);
1203     } else if (method_has_option("UseRTMLockEliding") || ((rtm_state & UseRTM) != 0) || !UseRTMDeopt) {
1204       // Generate RTM lock eliding code without abort ratio calculation code.
1205       set_rtm_state(UseRTM);
1206     } else if (UseRTMDeopt) {
1207       // Generate RTM lock eliding code and include abort ratio calculation
1208       // code if UseRTMDeopt is on.
1209       set_rtm_state(ProfileRTM);
1210     }
1211   }
1212 #endif
1213   if (VM_Version::supports_fast_class_init_checks() && has_method() && !is_osr_compilation() && method()->needs_clinit_barrier()) {
1214     set_clinit_barrier_on_entry(true);
1215   }
1216   if (debug_info()->recording_non_safepoints()) {
1217     set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
1218                         (comp_arena(), 8, 0, NULL));
1219     set_default_node_notes(Node_Notes::make(this));
1220   }
1221 
1222   // // -- Initialize types before each compile --
1223   // // Update cached type information
1224   // if( _method && _method->constants() )
1225   //   Type::update_loaded_types(_method, _method->constants());
1226 
1227   // Init alias_type map.
1228   if (!_do_escape_analysis && aliaslevel == 3)
1229     aliaslevel = 2;  // No unique types without escape analysis
1230   _AliasLevel = aliaslevel;
1231   const int grow_ats = 16;
1232   _max_alias_types = grow_ats;
1233   _alias_types   = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
1234   AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType,  grow_ats);
1235   Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
1236   {
1237     for (int i = 0; i < grow_ats; i++)  _alias_types[i] = &ats[i];
1238   }
1239   // Initialize the first few types.
1240   _alias_types[AliasIdxTop]->Init(AliasIdxTop, NULL);
1241   _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
1242   _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
1243   _num_alias_types = AliasIdxRaw+1;
1244   // Zero out the alias type cache.
1245   Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
1246   // A NULL adr_type hits in the cache right away.  Preload the right answer.
1247   probe_alias_cache(NULL)->_index = AliasIdxTop;
1248 
1249   _intrinsics = NULL;
1250   _macro_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1251   _predicate_opaqs = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1252   _expensive_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1253   _range_check_casts = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1254   _opaque4_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1255   _value_type_nodes = new (comp_arena()) Unique_Node_List(comp_arena());
1256   register_library_intrinsics();
1257 }
1258 
1259 //---------------------------init_start----------------------------------------
1260 // Install the StartNode on this compile object.
1261 void Compile::init_start(StartNode* s) {
1262   if (failing())
1263     return; // already failing
1264   assert(s == start(), "");
1265 }
1266 
1267 /**
1268  * Return the 'StartNode'. We must not have a pending failure, since the ideal graph
1269  * can be in an inconsistent state, i.e., we can get segmentation faults when traversing
1270  * the ideal graph.
1271  */
1272 StartNode* Compile::start() const {
1273   assert (!failing(), "Must not have pending failure. Reason is: %s", failure_reason());
1274   for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
1275     Node* start = root()->fast_out(i);
1276     if (start->is_Start()) {
1277       return start->as_Start();
1278     }
1279   }
1280   fatal("Did not find Start node!");
1281   return NULL;
1282 }
1283 
1284 //-------------------------------immutable_memory-------------------------------------
1285 // Access immutable memory
1286 Node* Compile::immutable_memory() {
1287   if (_immutable_memory != NULL) {
1288     return _immutable_memory;
1289   }
1290   StartNode* s = start();
1291   for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
1292     Node *p = s->fast_out(i);
1293     if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
1294       _immutable_memory = p;
1295       return _immutable_memory;
1296     }
1297   }
1298   ShouldNotReachHere();
1299   return NULL;
1300 }
1301 
1302 //----------------------set_cached_top_node------------------------------------
1303 // Install the cached top node, and make sure Node::is_top works correctly.
1304 void Compile::set_cached_top_node(Node* tn) {
1305   if (tn != NULL)  verify_top(tn);
1306   Node* old_top = _top;
1307   _top = tn;
1308   // Calling Node::setup_is_top allows the nodes the chance to adjust
1309   // their _out arrays.
1310   if (_top != NULL)     _top->setup_is_top();
1311   if (old_top != NULL)  old_top->setup_is_top();
1312   assert(_top == NULL || top()->is_top(), "");
1313 }
1314 
1315 #ifdef ASSERT
1316 uint Compile::count_live_nodes_by_graph_walk() {
1317   Unique_Node_List useful(comp_arena());
1318   // Get useful node list by walking the graph.
1319   identify_useful_nodes(useful);
1320   return useful.size();
1321 }
1322 
1323 void Compile::print_missing_nodes() {
1324 
1325   // Return if CompileLog is NULL and PrintIdealNodeCount is false.
1326   if ((_log == NULL) && (! PrintIdealNodeCount)) {
1327     return;
1328   }
1329 
1330   // This is an expensive function. It is executed only when the user
1331   // specifies VerifyIdealNodeCount option or otherwise knows the
1332   // additional work that needs to be done to identify reachable nodes
1333   // by walking the flow graph and find the missing ones using
1334   // _dead_node_list.
1335 
1336   Unique_Node_List useful(comp_arena());
1337   // Get useful node list by walking the graph.
1338   identify_useful_nodes(useful);
1339 
1340   uint l_nodes = C->live_nodes();
1341   uint l_nodes_by_walk = useful.size();
1342 
1343   if (l_nodes != l_nodes_by_walk) {
1344     if (_log != NULL) {
1345       _log->begin_head("mismatched_nodes count='%d'", abs((int) (l_nodes - l_nodes_by_walk)));
1346       _log->stamp();
1347       _log->end_head();
1348     }
1349     VectorSet& useful_member_set = useful.member_set();
1350     int last_idx = l_nodes_by_walk;
1351     for (int i = 0; i < last_idx; i++) {
1352       if (useful_member_set.test(i)) {
1353         if (_dead_node_list.test(i)) {
1354           if (_log != NULL) {
1355             _log->elem("mismatched_node_info node_idx='%d' type='both live and dead'", i);
1356           }
1357           if (PrintIdealNodeCount) {
1358             // Print the log message to tty
1359               tty->print_cr("mismatched_node idx='%d' both live and dead'", i);
1360               useful.at(i)->dump();
1361           }
1362         }
1363       }
1364       else if (! _dead_node_list.test(i)) {
1365         if (_log != NULL) {
1366           _log->elem("mismatched_node_info node_idx='%d' type='neither live nor dead'", i);
1367         }
1368         if (PrintIdealNodeCount) {
1369           // Print the log message to tty
1370           tty->print_cr("mismatched_node idx='%d' type='neither live nor dead'", i);
1371         }
1372       }
1373     }
1374     if (_log != NULL) {
1375       _log->tail("mismatched_nodes");
1376     }
1377   }
1378 }
1379 void Compile::record_modified_node(Node* n) {
1380   if (_modified_nodes != NULL && !_inlining_incrementally &&
1381       n->outcnt() != 0 && !n->is_Con()) {
1382     _modified_nodes->push(n);
1383   }
1384 }
1385 
1386 void Compile::remove_modified_node(Node* n) {
1387   if (_modified_nodes != NULL) {
1388     _modified_nodes->remove(n);
1389   }
1390 }
1391 #endif
1392 
1393 #ifndef PRODUCT
1394 void Compile::verify_top(Node* tn) const {
1395   if (tn != NULL) {
1396     assert(tn->is_Con(), "top node must be a constant");
1397     assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
1398     assert(tn->in(0) != NULL, "must have live top node");
1399   }
1400 }
1401 #endif
1402 
1403 
1404 ///-------------------Managing Per-Node Debug & Profile Info-------------------
1405 
1406 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
1407   guarantee(arr != NULL, "");
1408   int num_blocks = arr->length();
1409   if (grow_by < num_blocks)  grow_by = num_blocks;
1410   int num_notes = grow_by * _node_notes_block_size;
1411   Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
1412   Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
1413   while (num_notes > 0) {
1414     arr->append(notes);
1415     notes     += _node_notes_block_size;
1416     num_notes -= _node_notes_block_size;
1417   }
1418   assert(num_notes == 0, "exact multiple, please");
1419 }
1420 
1421 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
1422   if (source == NULL || dest == NULL)  return false;
1423 
1424   if (dest->is_Con())
1425     return false;               // Do not push debug info onto constants.
1426 
1427 #ifdef ASSERT
1428   // Leave a bread crumb trail pointing to the original node:
1429   if (dest != NULL && dest != source && dest->debug_orig() == NULL) {
1430     dest->set_debug_orig(source);
1431   }
1432 #endif
1433 
1434   if (node_note_array() == NULL)
1435     return false;               // Not collecting any notes now.
1436 
1437   // This is a copy onto a pre-existing node, which may already have notes.
1438   // If both nodes have notes, do not overwrite any pre-existing notes.
1439   Node_Notes* source_notes = node_notes_at(source->_idx);
1440   if (source_notes == NULL || source_notes->is_clear())  return false;
1441   Node_Notes* dest_notes   = node_notes_at(dest->_idx);
1442   if (dest_notes == NULL || dest_notes->is_clear()) {
1443     return set_node_notes_at(dest->_idx, source_notes);
1444   }
1445 
1446   Node_Notes merged_notes = (*source_notes);
1447   // The order of operations here ensures that dest notes will win...
1448   merged_notes.update_from(dest_notes);
1449   return set_node_notes_at(dest->_idx, &merged_notes);
1450 }
1451 
1452 
1453 //--------------------------allow_range_check_smearing-------------------------
1454 // Gating condition for coalescing similar range checks.
1455 // Sometimes we try 'speculatively' replacing a series of a range checks by a
1456 // single covering check that is at least as strong as any of them.
1457 // If the optimization succeeds, the simplified (strengthened) range check
1458 // will always succeed.  If it fails, we will deopt, and then give up
1459 // on the optimization.
1460 bool Compile::allow_range_check_smearing() const {
1461   // If this method has already thrown a range-check,
1462   // assume it was because we already tried range smearing
1463   // and it failed.
1464   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
1465   return !already_trapped;
1466 }
1467 
1468 
1469 //------------------------------flatten_alias_type-----------------------------
1470 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
1471   int offset = tj->offset();
1472   TypePtr::PTR ptr = tj->ptr();
1473 
1474   // Known instance (scalarizable allocation) alias only with itself.
1475   bool is_known_inst = tj->isa_oopptr() != NULL &&
1476                        tj->is_oopptr()->is_known_instance();
1477 
1478   // Process weird unsafe references.
1479   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
1480     bool default_value_load = EnableValhalla && tj->is_instptr()->klass() == ciEnv::current()->Class_klass();
1481     assert(InlineUnsafeOps || default_value_load, "indeterminate pointers come only from unsafe ops");
1482     assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
1483     tj = TypeOopPtr::BOTTOM;
1484     ptr = tj->ptr();
1485     offset = tj->offset();
1486   }
1487 
1488   // Array pointers need some flattening
1489   const TypeAryPtr *ta = tj->isa_aryptr();
1490   if (ta && ta->is_stable()) {
1491     // Erase stability property for alias analysis.
1492     tj = ta = ta->cast_to_stable(false);
1493   }
1494   if (ta && ta->is_not_flat()) {
1495     // Erase not flat property for alias analysis.
1496     tj = ta = ta->cast_to_not_flat(false);
1497   }
1498   if (ta && ta->is_not_null_free()) {
1499     // Erase not null free property for alias analysis.
1500     tj = ta = ta->cast_to_not_null_free(false);
1501   }
1502 
1503   if( ta && is_known_inst ) {
1504     if ( offset != Type::OffsetBot &&
1505          offset > arrayOopDesc::length_offset_in_bytes() ) {
1506       offset = Type::OffsetBot; // Flatten constant access into array body only
1507       tj = ta = TypeAryPtr::make(ptr, ta->ary(), ta->klass(), true, Type::Offset(offset), ta->field_offset(), ta->instance_id());
1508     }
1509   } else if( ta && _AliasLevel >= 2 ) {
1510     // For arrays indexed by constant indices, we flatten the alias
1511     // space to include all of the array body.  Only the header, klass
1512     // and array length can be accessed un-aliased.
1513     // For flattened value type array, each field has its own slice so
1514     // we must include the field offset.
1515     if( offset != Type::OffsetBot ) {
1516       if( ta->const_oop() ) { // MethodData* or Method*
1517         offset = Type::OffsetBot;   // Flatten constant access into array body
1518         tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),ta->ary(),ta->klass(),false,Type::Offset(offset), ta->field_offset());
1519       } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
1520         // range is OK as-is.
1521         tj = ta = TypeAryPtr::RANGE;
1522       } else if( offset == oopDesc::klass_offset_in_bytes() ) {
1523         tj = TypeInstPtr::KLASS; // all klass loads look alike
1524         ta = TypeAryPtr::RANGE; // generic ignored junk
1525         ptr = TypePtr::BotPTR;
1526       } else if( offset == oopDesc::mark_offset_in_bytes() ) {
1527         tj = TypeInstPtr::MARK;
1528         ta = TypeAryPtr::RANGE; // generic ignored junk
1529         ptr = TypePtr::BotPTR;
1530       } else if (BarrierSet::barrier_set()->barrier_set_c2()->flatten_gc_alias_type(tj)) {
1531         ta = tj->isa_aryptr();
1532       } else {                  // Random constant offset into array body
1533         offset = Type::OffsetBot;   // Flatten constant access into array body
1534         tj = ta = TypeAryPtr::make(ptr,ta->ary(),ta->klass(),false,Type::Offset(offset), ta->field_offset());
1535       }
1536     }
1537     // Arrays of fixed size alias with arrays of unknown size.
1538     if (ta->size() != TypeInt::POS) {
1539       const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
1540       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,ta->klass(),false,Type::Offset(offset), ta->field_offset());
1541     }
1542     // Arrays of known objects become arrays of unknown objects.
1543     if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
1544       const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
1545       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,Type::Offset(offset), ta->field_offset());
1546     }
1547     if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
1548       const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
1549       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,Type::Offset(offset), ta->field_offset());
1550     }
1551     // Initially all flattened array accesses share a single slice
1552     if (ta->elem()->isa_valuetype() && ta->elem() != TypeValueType::BOTTOM && _flattened_accesses_share_alias) {
1553       const TypeAry *tary = TypeAry::make(TypeValueType::BOTTOM, ta->size());
1554       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,Type::Offset(offset), Type::Offset(Type::OffsetBot));
1555     }
1556     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
1557     // cannot be distinguished by bytecode alone.
1558     if (ta->elem() == TypeInt::BOOL) {
1559       const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
1560       ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
1561       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,Type::Offset(offset), ta->field_offset());
1562     }
1563     // During the 2nd round of IterGVN, NotNull castings are removed.
1564     // Make sure the Bottom and NotNull variants alias the same.
1565     // Also, make sure exact and non-exact variants alias the same.
1566     if (ptr == TypePtr::NotNull || ta->klass_is_exact() || ta->speculative() != NULL) {
1567       tj = ta = TypeAryPtr::make(TypePtr::BotPTR,ta->ary(),ta->klass(),false,Type::Offset(offset), ta->field_offset());
1568     }
1569   }
1570 
1571   // Oop pointers need some flattening
1572   const TypeInstPtr *to = tj->isa_instptr();
1573   if( to && _AliasLevel >= 2 && to != TypeOopPtr::BOTTOM ) {
1574     ciInstanceKlass *k = to->klass()->as_instance_klass();
1575     if( ptr == TypePtr::Constant ) {
1576       if (to->klass() != ciEnv::current()->Class_klass() ||
1577           offset < k->size_helper() * wordSize) {
1578         // No constant oop pointers (such as Strings); they alias with
1579         // unknown strings.
1580         assert(!is_known_inst, "not scalarizable allocation");
1581         tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,Type::Offset(offset), to->klass()->flatten_array());
1582       }
1583     } else if( is_known_inst ) {
1584       tj = to; // Keep NotNull and klass_is_exact for instance type
1585     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
1586       // During the 2nd round of IterGVN, NotNull castings are removed.
1587       // Make sure the Bottom and NotNull variants alias the same.
1588       // Also, make sure exact and non-exact variants alias the same.
1589       tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,Type::Offset(offset), to->klass()->flatten_array());
1590     }
1591     if (to->speculative() != NULL) {
1592       tj = to = TypeInstPtr::make(to->ptr(),to->klass(),to->klass_is_exact(),to->const_oop(),Type::Offset(to->offset()), to->klass()->flatten_array(), to->instance_id());
1593     }
1594     // Canonicalize the holder of this field
1595     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
1596       // First handle header references such as a LoadKlassNode, even if the
1597       // object's klass is unloaded at compile time (4965979).
1598       if (!is_known_inst) { // Do it only for non-instance types
1599         tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, NULL, Type::Offset(offset), false);
1600       }
1601     } else if (BarrierSet::barrier_set()->barrier_set_c2()->flatten_gc_alias_type(tj)) {
1602       to = tj->is_instptr();
1603     } else if (offset < 0 || offset >= k->size_helper() * wordSize) {
1604       // Static fields are in the space above the normal instance
1605       // fields in the java.lang.Class instance.
1606       if (to->klass() != ciEnv::current()->Class_klass()) {
1607         to = NULL;
1608         tj = TypeOopPtr::BOTTOM;
1609         offset = tj->offset();
1610       }
1611     } else {
1612       ciInstanceKlass *canonical_holder = k->get_canonical_holder(offset);
1613       if (!k->equals(canonical_holder) || tj->offset() != offset) {
1614         if( is_known_inst ) {
1615           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, true, NULL, Type::Offset(offset), canonical_holder->flatten_array(), to->instance_id());
1616         } else {
1617           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, false, NULL, Type::Offset(offset), canonical_holder->flatten_array());
1618         }
1619       }
1620     }
1621   }
1622 
1623   // Klass pointers to object array klasses need some flattening
1624   const TypeKlassPtr *tk = tj->isa_klassptr();
1625   if( tk ) {
1626     // If we are referencing a field within a Klass, we need
1627     // to assume the worst case of an Object.  Both exact and
1628     // inexact types must flatten to the same alias class so
1629     // use NotNull as the PTR.
1630     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
1631 
1632       tj = tk = TypeKlassPtr::make(TypePtr::NotNull,
1633                                    TypeKlassPtr::OBJECT->klass(),
1634                                    Type::Offset(offset),
1635                                    false);
1636     }
1637 
1638     ciKlass* klass = tk->klass();
1639     if (klass != NULL && klass->is_obj_array_klass()) {
1640       ciKlass* k = TypeAryPtr::OOPS->klass();
1641       if( !k || !k->is_loaded() )                  // Only fails for some -Xcomp runs
1642         k = TypeInstPtr::BOTTOM->klass();
1643       tj = tk = TypeKlassPtr::make(TypePtr::NotNull, k, Type::Offset(offset), false);
1644     }
1645 
1646     // Check for precise loads from the primary supertype array and force them
1647     // to the supertype cache alias index.  Check for generic array loads from
1648     // the primary supertype array and also force them to the supertype cache
1649     // alias index.  Since the same load can reach both, we need to merge
1650     // these 2 disparate memories into the same alias class.  Since the
1651     // primary supertype array is read-only, there's no chance of confusion
1652     // where we bypass an array load and an array store.
1653     int primary_supers_offset = in_bytes(Klass::primary_supers_offset());
1654     if (offset == Type::OffsetBot ||
1655         (offset >= primary_supers_offset &&
1656          offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
1657         offset == (int)in_bytes(Klass::secondary_super_cache_offset())) {
1658       offset = in_bytes(Klass::secondary_super_cache_offset());
1659       tj = tk = TypeKlassPtr::make(TypePtr::NotNull, tk->klass(), Type::Offset(offset), tk->flat_array());
1660     }
1661   }
1662 
1663   // Flatten all Raw pointers together.
1664   if (tj->base() == Type::RawPtr)
1665     tj = TypeRawPtr::BOTTOM;
1666 
1667   if (tj->base() == Type::AnyPtr)
1668     tj = TypePtr::BOTTOM;      // An error, which the caller must check for.
1669 
1670   // Flatten all to bottom for now
1671   switch( _AliasLevel ) {
1672   case 0:
1673     tj = TypePtr::BOTTOM;
1674     break;
1675   case 1:                       // Flatten to: oop, static, field or array
1676     switch (tj->base()) {
1677     //case Type::AryPtr: tj = TypeAryPtr::RANGE;    break;
1678     case Type::RawPtr:   tj = TypeRawPtr::BOTTOM;   break;
1679     case Type::AryPtr:   // do not distinguish arrays at all
1680     case Type::InstPtr:  tj = TypeInstPtr::BOTTOM;  break;
1681     case Type::KlassPtr: tj = TypeKlassPtr::OBJECT; break;
1682     case Type::AnyPtr:   tj = TypePtr::BOTTOM;      break;  // caller checks it
1683     default: ShouldNotReachHere();
1684     }
1685     break;
1686   case 2:                       // No collapsing at level 2; keep all splits
1687   case 3:                       // No collapsing at level 3; keep all splits
1688     break;
1689   default:
1690     Unimplemented();
1691   }
1692 
1693   offset = tj->offset();
1694   assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
1695 
1696   assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
1697           (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
1698           (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
1699           (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
1700           (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1701           (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1702           (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1703           (BarrierSet::barrier_set()->barrier_set_c2()->verify_gc_alias_type(tj, offset)),
1704           "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
1705   assert( tj->ptr() != TypePtr::TopPTR &&
1706           tj->ptr() != TypePtr::AnyNull &&
1707           tj->ptr() != TypePtr::Null, "No imprecise addresses" );
1708 //    assert( tj->ptr() != TypePtr::Constant ||
1709 //            tj->base() == Type::RawPtr ||
1710 //            tj->base() == Type::KlassPtr, "No constant oop addresses" );
1711 
1712   return tj;
1713 }
1714 
1715 void Compile::AliasType::Init(int i, const TypePtr* at) {
1716   _index = i;
1717   _adr_type = at;
1718   _field = NULL;
1719   _element = NULL;
1720   _is_rewritable = true; // default
1721   const TypeOopPtr *atoop = (at != NULL) ? at->isa_oopptr() : NULL;
1722   if (atoop != NULL && atoop->is_known_instance()) {
1723     const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
1724     _general_index = Compile::current()->get_alias_index(gt);
1725   } else {
1726     _general_index = 0;
1727   }
1728 }
1729 
1730 BasicType Compile::AliasType::basic_type() const {
1731   if (element() != NULL) {
1732     const Type* element = adr_type()->is_aryptr()->elem();
1733     return element->isa_narrowoop() ? T_OBJECT : element->array_element_basic_type();
1734   } if (field() != NULL) {
1735     return field()->layout_type();
1736   } else {
1737     return T_ILLEGAL; // unknown
1738   }
1739 }
1740 
1741 //---------------------------------print_on------------------------------------
1742 #ifndef PRODUCT
1743 void Compile::AliasType::print_on(outputStream* st) {
1744   if (index() < 10)
1745         st->print("@ <%d> ", index());
1746   else  st->print("@ <%d>",  index());
1747   st->print(is_rewritable() ? "   " : " RO");
1748   int offset = adr_type()->offset();
1749   if (offset == Type::OffsetBot)
1750         st->print(" +any");
1751   else  st->print(" +%-3d", offset);
1752   st->print(" in ");
1753   adr_type()->dump_on(st);
1754   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
1755   if (field() != NULL && tjp) {
1756     if (tjp->klass()  != field()->holder() ||
1757         tjp->offset() != field()->offset_in_bytes()) {
1758       st->print(" != ");
1759       field()->print();
1760       st->print(" ***");
1761     }
1762   }
1763 }
1764 
1765 void print_alias_types() {
1766   Compile* C = Compile::current();
1767   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
1768   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
1769     C->alias_type(idx)->print_on(tty);
1770     tty->cr();
1771   }
1772 }
1773 #endif
1774 
1775 
1776 //----------------------------probe_alias_cache--------------------------------
1777 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
1778   intptr_t key = (intptr_t) adr_type;
1779   key ^= key >> logAliasCacheSize;
1780   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
1781 }
1782 
1783 
1784 //-----------------------------grow_alias_types--------------------------------
1785 void Compile::grow_alias_types() {
1786   const int old_ats  = _max_alias_types; // how many before?
1787   const int new_ats  = old_ats;          // how many more?
1788   const int grow_ats = old_ats+new_ats;  // how many now?
1789   _max_alias_types = grow_ats;
1790   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
1791   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
1792   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
1793   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
1794 }
1795 
1796 
1797 //--------------------------------find_alias_type------------------------------
1798 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field, bool uncached) {
1799   if (_AliasLevel == 0)
1800     return alias_type(AliasIdxBot);
1801 
1802   AliasCacheEntry* ace = NULL;
1803   if (!uncached) {
1804     ace = probe_alias_cache(adr_type);
1805     if (ace->_adr_type == adr_type) {
1806       return alias_type(ace->_index);
1807     }
1808   }
1809 
1810   // Handle special cases.
1811   if (adr_type == NULL)             return alias_type(AliasIdxTop);
1812   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
1813 
1814   // Do it the slow way.
1815   const TypePtr* flat = flatten_alias_type(adr_type);
1816 
1817 #ifdef ASSERT
1818   {
1819     ResourceMark rm;
1820     assert(flat == flatten_alias_type(flat), "not idempotent: adr_type = %s; flat = %s => %s",
1821            Type::str(adr_type), Type::str(flat), Type::str(flatten_alias_type(flat)));
1822     assert(flat != TypePtr::BOTTOM, "cannot alias-analyze an untyped ptr: adr_type = %s",
1823            Type::str(adr_type));
1824     if (flat->isa_oopptr() && !flat->isa_klassptr()) {
1825       const TypeOopPtr* foop = flat->is_oopptr();
1826       // Scalarizable allocations have exact klass always.
1827       bool exact = !foop->klass_is_exact() || foop->is_known_instance();
1828       const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
1829       assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type: foop = %s; xoop = %s",
1830              Type::str(foop), Type::str(xoop));
1831     }
1832   }
1833 #endif
1834 
1835   int idx = AliasIdxTop;
1836   for (int i = 0; i < num_alias_types(); i++) {
1837     if (alias_type(i)->adr_type() == flat) {
1838       idx = i;
1839       break;
1840     }
1841   }
1842 
1843   if (idx == AliasIdxTop) {
1844     if (no_create)  return NULL;
1845     // Grow the array if necessary.
1846     if (_num_alias_types == _max_alias_types)  grow_alias_types();
1847     // Add a new alias type.
1848     idx = _num_alias_types++;
1849     _alias_types[idx]->Init(idx, flat);
1850     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
1851     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
1852     if (flat->isa_instptr()) {
1853       if (flat->offset() == java_lang_Class::klass_offset_in_bytes()
1854           && flat->is_instptr()->klass() == env()->Class_klass())
1855         alias_type(idx)->set_rewritable(false);
1856     }
1857     ciField* field = NULL;
1858     if (flat->isa_aryptr()) {
1859 #ifdef ASSERT
1860       const int header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1861       // (T_BYTE has the weakest alignment and size restrictions...)
1862       assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
1863 #endif
1864       const Type* elemtype = flat->is_aryptr()->elem();
1865       if (flat->offset() == TypePtr::OffsetBot) {
1866         alias_type(idx)->set_element(elemtype);
1867       }
1868       int field_offset = flat->is_aryptr()->field_offset().get();
1869       if (elemtype->isa_valuetype() &&
1870           elemtype->value_klass() != NULL &&
1871           field_offset != Type::OffsetBot) {
1872         ciValueKlass* vk = elemtype->value_klass();
1873         field_offset += vk->first_field_offset();
1874         field = vk->get_field_by_offset(field_offset, false);
1875       }
1876     }
1877     if (flat->isa_klassptr()) {
1878       if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
1879         alias_type(idx)->set_rewritable(false);
1880       if (flat->offset() == in_bytes(Klass::modifier_flags_offset()))
1881         alias_type(idx)->set_rewritable(false);
1882       if (flat->offset() == in_bytes(Klass::access_flags_offset()))
1883         alias_type(idx)->set_rewritable(false);
1884       if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
1885         alias_type(idx)->set_rewritable(false);
1886       if (flat->offset() == in_bytes(Klass::layout_helper_offset()))
1887         alias_type(idx)->set_rewritable(false);
1888     }
1889     // %%% (We would like to finalize JavaThread::threadObj_offset(),
1890     // but the base pointer type is not distinctive enough to identify
1891     // references into JavaThread.)
1892 
1893     // Check for final fields.
1894     const TypeInstPtr* tinst = flat->isa_instptr();
1895     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
1896       if (tinst->const_oop() != NULL &&
1897           tinst->klass() == ciEnv::current()->Class_klass() &&
1898           tinst->offset() >= (tinst->klass()->as_instance_klass()->size_helper() * wordSize)) {
1899         // static field
1900         ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
1901         field = k->get_field_by_offset(tinst->offset(), true);
1902       } else if (tinst->klass()->is_valuetype()) {
1903         // Value type field
1904         ciValueKlass* vk = tinst->value_klass();
1905         field = vk->get_field_by_offset(tinst->offset(), false);
1906       } else {
1907         ciInstanceKlass* k = tinst->klass()->as_instance_klass();
1908         field = k->get_field_by_offset(tinst->offset(), false);
1909       }
1910     }
1911     assert(field == NULL ||
1912            original_field == NULL ||
1913            (field->holder() == original_field->holder() &&
1914             field->offset() == original_field->offset() &&
1915             field->is_static() == original_field->is_static()), "wrong field?");
1916     // Set field() and is_rewritable() attributes.
1917     if (field != NULL) {
1918       alias_type(idx)->set_field(field);
1919       if (flat->isa_aryptr()) {
1920         // Fields of flattened inline type arrays are rewritable although they are declared final
1921         assert(flat->is_aryptr()->elem()->isa_valuetype(), "must be a flattened value array");
1922         alias_type(idx)->set_rewritable(true);
1923       }
1924     }
1925   }
1926 
1927   // Fill the cache for next time.
1928   if (!uncached) {
1929     ace->_adr_type = adr_type;
1930     ace->_index    = idx;
1931     assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
1932 
1933     // Might as well try to fill the cache for the flattened version, too.
1934     AliasCacheEntry* face = probe_alias_cache(flat);
1935     if (face->_adr_type == NULL) {
1936       face->_adr_type = flat;
1937       face->_index    = idx;
1938       assert(alias_type(flat) == alias_type(idx), "flat type must work too");
1939     }
1940   }
1941 
1942   return alias_type(idx);
1943 }
1944 
1945 
1946 Compile::AliasType* Compile::alias_type(ciField* field) {
1947   const TypeOopPtr* t;
1948   if (field->is_static())
1949     t = TypeInstPtr::make(field->holder()->java_mirror());
1950   else
1951     t = TypeOopPtr::make_from_klass_raw(field->holder());
1952   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);
1953   assert((field->is_final() || field->is_stable()) == !atp->is_rewritable(), "must get the rewritable bits correct");
1954   return atp;
1955 }
1956 
1957 
1958 //------------------------------have_alias_type--------------------------------
1959 bool Compile::have_alias_type(const TypePtr* adr_type) {
1960   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1961   if (ace->_adr_type == adr_type) {
1962     return true;
1963   }
1964 
1965   // Handle special cases.
1966   if (adr_type == NULL)             return true;
1967   if (adr_type == TypePtr::BOTTOM)  return true;
1968 
1969   return find_alias_type(adr_type, true, NULL) != NULL;
1970 }
1971 
1972 //-----------------------------must_alias--------------------------------------
1973 // True if all values of the given address type are in the given alias category.
1974 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
1975   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1976   if (adr_type == NULL)                 return true;  // NULL serves as TypePtr::TOP
1977   if (alias_idx == AliasIdxTop)         return false; // the empty category
1978   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
1979 
1980   // the only remaining possible overlap is identity
1981   int adr_idx = get_alias_index(adr_type);
1982   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1983   assert(adr_idx == alias_idx ||
1984          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
1985           && adr_type                       != TypeOopPtr::BOTTOM),
1986          "should not be testing for overlap with an unsafe pointer");
1987   return adr_idx == alias_idx;
1988 }
1989 
1990 //------------------------------can_alias--------------------------------------
1991 // True if any values of the given address type are in the given alias category.
1992 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
1993   if (alias_idx == AliasIdxTop)         return false; // the empty category
1994   if (adr_type == NULL)                 return false; // NULL serves as TypePtr::TOP
1995   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1996   if (adr_type->base() == Type::AnyPtr) return true;  // TypePtr::BOTTOM or its twins
1997 
1998   // the only remaining possible overlap is identity
1999   int adr_idx = get_alias_index(adr_type);
2000   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
2001   return adr_idx == alias_idx;
2002 }
2003 
2004 
2005 
2006 //---------------------------pop_warm_call-------------------------------------
2007 WarmCallInfo* Compile::pop_warm_call() {
2008   WarmCallInfo* wci = _warm_calls;
2009   if (wci != NULL)  _warm_calls = wci->remove_from(wci);
2010   return wci;
2011 }
2012 
2013 //----------------------------Inline_Warm--------------------------------------
2014 int Compile::Inline_Warm() {
2015   // If there is room, try to inline some more warm call sites.
2016   // %%% Do a graph index compaction pass when we think we're out of space?
2017   if (!InlineWarmCalls)  return 0;
2018 
2019   int calls_made_hot = 0;
2020   int room_to_grow   = NodeCountInliningCutoff - unique();
2021   int amount_to_grow = MIN2(room_to_grow, (int)NodeCountInliningStep);
2022   int amount_grown   = 0;
2023   WarmCallInfo* call;
2024   while (amount_to_grow > 0 && (call = pop_warm_call()) != NULL) {
2025     int est_size = (int)call->size();
2026     if (est_size > (room_to_grow - amount_grown)) {
2027       // This one won't fit anyway.  Get rid of it.
2028       call->make_cold();
2029       continue;
2030     }
2031     call->make_hot();
2032     calls_made_hot++;
2033     amount_grown   += est_size;
2034     amount_to_grow -= est_size;
2035   }
2036 
2037   if (calls_made_hot > 0)  set_major_progress();
2038   return calls_made_hot;
2039 }
2040 
2041 
2042 //----------------------------Finish_Warm--------------------------------------
2043 void Compile::Finish_Warm() {
2044   if (!InlineWarmCalls)  return;
2045   if (failing())  return;
2046   if (warm_calls() == NULL)  return;
2047 
2048   // Clean up loose ends, if we are out of space for inlining.
2049   WarmCallInfo* call;
2050   while ((call = pop_warm_call()) != NULL) {
2051     call->make_cold();
2052   }
2053 }
2054 
2055 //---------------------cleanup_loop_predicates-----------------------
2056 // Remove the opaque nodes that protect the predicates so that all unused
2057 // checks and uncommon_traps will be eliminated from the ideal graph
2058 void Compile::cleanup_loop_predicates(PhaseIterGVN &igvn) {
2059   if (predicate_count()==0) return;
2060   for (int i = predicate_count(); i > 0; i--) {
2061     Node * n = predicate_opaque1_node(i-1);
2062     assert(n->Opcode() == Op_Opaque1, "must be");
2063     igvn.replace_node(n, n->in(1));
2064   }
2065   assert(predicate_count()==0, "should be clean!");
2066 }
2067 
2068 void Compile::add_range_check_cast(Node* n) {
2069   assert(n->isa_CastII()->has_range_check(), "CastII should have range check dependency");
2070   assert(!_range_check_casts->contains(n), "duplicate entry in range check casts");
2071   _range_check_casts->append(n);
2072 }
2073 
2074 // Remove all range check dependent CastIINodes.
2075 void Compile::remove_range_check_casts(PhaseIterGVN &igvn) {
2076   for (int i = range_check_cast_count(); i > 0; i--) {
2077     Node* cast = range_check_cast_node(i-1);
2078     assert(cast->isa_CastII()->has_range_check(), "CastII should have range check dependency");
2079     igvn.replace_node(cast, cast->in(1));
2080   }
2081   assert(range_check_cast_count() == 0, "should be empty");
2082 }
2083 
2084 void Compile::add_opaque4_node(Node* n) {
2085   assert(n->Opcode() == Op_Opaque4, "Opaque4 only");
2086   assert(!_opaque4_nodes->contains(n), "duplicate entry in Opaque4 list");
2087   _opaque4_nodes->append(n);
2088 }
2089 
2090 // Remove all Opaque4 nodes.
2091 void Compile::remove_opaque4_nodes(PhaseIterGVN &igvn) {
2092   for (int i = opaque4_count(); i > 0; i--) {
2093     Node* opaq = opaque4_node(i-1);
2094     assert(opaq->Opcode() == Op_Opaque4, "Opaque4 only");
2095     igvn.replace_node(opaq, opaq->in(2));
2096   }
2097   assert(opaque4_count() == 0, "should be empty");
2098 }
2099 
2100 void Compile::add_value_type(Node* n) {
2101   assert(n->is_ValueTypeBase(), "unexpected node");
2102   if (_value_type_nodes != NULL) {
2103     _value_type_nodes->push(n);
2104   }
2105 }
2106 
2107 void Compile::remove_value_type(Node* n) {
2108   assert(n->is_ValueTypeBase(), "unexpected node");
2109   if (_value_type_nodes != NULL) {
2110     _value_type_nodes->remove(n);
2111   }
2112 }
2113 
2114 // Does the return value keep otherwise useless value type allocations
2115 // alive?
2116 static bool return_val_keeps_allocations_alive(Node* ret_val) {
2117   ResourceMark rm;
2118   Unique_Node_List wq;
2119   wq.push(ret_val);
2120   bool some_allocations = false;
2121   for (uint i = 0; i < wq.size(); i++) {
2122     Node* n = wq.at(i);
2123     assert(!n->is_ValueTypeBase(), "chain of value type nodes");
2124     if (n->outcnt() > 1) {
2125       // Some other use for the allocation
2126       return false;
2127     } else if (n->is_Phi()) {
2128       for (uint j = 1; j < n->req(); j++) {
2129         wq.push(n->in(j));
2130       }
2131     } else if (n->is_CheckCastPP() &&
2132                n->in(1)->is_Proj() &&
2133                n->in(1)->in(0)->is_Allocate()) {
2134       some_allocations = true;
2135     }
2136   }
2137   return some_allocations;
2138 }
2139 
2140 void Compile::process_value_types(PhaseIterGVN &igvn) {
2141   // Make value types scalar in safepoints
2142   while (_value_type_nodes->size() != 0) {
2143     ValueTypeBaseNode* vt = _value_type_nodes->pop()->as_ValueTypeBase();
2144     vt->make_scalar_in_safepoints(&igvn);
2145     if (vt->is_ValueTypePtr()) {
2146       igvn.replace_node(vt, vt->get_oop());
2147     } else if (vt->outcnt() == 0) {
2148       igvn.remove_dead_node(vt);
2149     }
2150   }
2151   _value_type_nodes = NULL;
2152   if (tf()->returns_value_type_as_fields()) {
2153     Node* ret = NULL;
2154     for (uint i = 1; i < root()->req(); i++){
2155       Node* in = root()->in(i);
2156       if (in->Opcode() == Op_Return) {
2157         assert(ret == NULL, "only one return");
2158         ret = in;
2159       }
2160     }
2161     if (ret != NULL) {
2162       Node* ret_val = ret->in(TypeFunc::Parms);
2163       if (igvn.type(ret_val)->isa_oopptr() &&
2164           return_val_keeps_allocations_alive(ret_val)) {
2165         igvn.replace_input_of(ret, TypeFunc::Parms, ValueTypeNode::tagged_klass(igvn.type(ret_val)->value_klass(), igvn));
2166         assert(ret_val->outcnt() == 0, "should be dead now");
2167         igvn.remove_dead_node(ret_val);
2168       }
2169     }
2170   }
2171   igvn.optimize();
2172 }
2173 
2174 void Compile::adjust_flattened_array_access_aliases(PhaseIterGVN& igvn) {
2175   if (!_has_flattened_accesses) {
2176     return;
2177   }
2178   // Initially, all flattened array accesses share the same slice to
2179   // keep dependencies with Object[] array accesses (that could be
2180   // to a flattened array) correct. We're done with parsing so we
2181   // now know all flattened array accesses in this compile
2182   // unit. Let's move flattened array accesses to their own slice,
2183   // one per element field. This should help memory access
2184   // optimizations.
2185   ResourceMark rm;
2186   Unique_Node_List wq;
2187   wq.push(root());
2188 
2189   Node_List mergememnodes;
2190   Node_List memnodes;
2191 
2192   // Alias index currently shared by all flattened memory accesses
2193   int index = get_alias_index(TypeAryPtr::VALUES);
2194 
2195   // Find MergeMem nodes and flattened array accesses
2196   for (uint i = 0; i < wq.size(); i++) {
2197     Node* n = wq.at(i);
2198     if (n->is_Mem()) {
2199       const TypePtr* adr_type = NULL;
2200       if (n->Opcode() == Op_StoreCM) {
2201         adr_type = get_adr_type(get_alias_index(n->in(MemNode::OopStore)->adr_type()));
2202       } else {
2203         adr_type = get_adr_type(get_alias_index(n->adr_type()));
2204       }
2205       if (adr_type == TypeAryPtr::VALUES) {
2206         memnodes.push(n);
2207       }
2208     } else if (n->is_MergeMem()) {
2209       MergeMemNode* mm = n->as_MergeMem();
2210       if (mm->memory_at(index) != mm->base_memory()) {
2211         mergememnodes.push(n);
2212       }
2213     }
2214     for (uint j = 0; j < n->req(); j++) {
2215       Node* m = n->in(j);
2216       if (m != NULL) {
2217         wq.push(m);
2218       }
2219     }
2220   }
2221 
2222   if (memnodes.size() > 0) {
2223     _flattened_accesses_share_alias = false;
2224 
2225     // We are going to change the slice for the flattened array
2226     // accesses so we need to clear the cache entries that refer to
2227     // them.
2228     for (uint i = 0; i < AliasCacheSize; i++) {
2229       AliasCacheEntry* ace = &_alias_cache[i];
2230       if (ace->_adr_type != NULL &&
2231           ace->_adr_type->isa_aryptr() &&
2232           ace->_adr_type->is_aryptr()->elem()->isa_valuetype()) {
2233         ace->_adr_type = NULL;
2234         ace->_index = 0;
2235       }
2236     }
2237 
2238     // Find what aliases we are going to add
2239     int start_alias = num_alias_types()-1;
2240     int stop_alias = 0;
2241 
2242     for (uint i = 0; i < memnodes.size(); i++) {
2243       Node* m = memnodes.at(i);
2244       const TypePtr* adr_type = NULL;
2245       if (m->Opcode() == Op_StoreCM) {
2246         adr_type = m->in(MemNode::OopStore)->adr_type();
2247         Node* clone = new StoreCMNode(m->in(MemNode::Control), m->in(MemNode::Memory), m->in(MemNode::Address),
2248                                       m->adr_type(), m->in(MemNode::ValueIn), m->in(MemNode::OopStore),
2249                                       get_alias_index(adr_type));
2250         igvn.register_new_node_with_optimizer(clone);
2251         igvn.replace_node(m, clone);
2252       } else {
2253         adr_type = m->adr_type();
2254 #ifdef ASSERT
2255         m->as_Mem()->set_adr_type(adr_type);
2256 #endif
2257       }
2258       int idx = get_alias_index(adr_type);
2259       start_alias = MIN2(start_alias, idx);
2260       stop_alias = MAX2(stop_alias, idx);
2261     }
2262 
2263     assert(stop_alias >= start_alias, "should have expanded aliases");
2264 
2265     Node_Stack stack(0);
2266 #ifdef ASSERT
2267     VectorSet seen(Thread::current()->resource_area());
2268 #endif
2269     // Now let's fix the memory graph so each flattened array access
2270     // is moved to the right slice. Start from the MergeMem nodes.
2271     uint last = unique();
2272     for (uint i = 0; i < mergememnodes.size(); i++) {
2273       MergeMemNode* current = mergememnodes.at(i)->as_MergeMem();
2274       Node* n = current->memory_at(index);
2275       MergeMemNode* mm = NULL;
2276       do {
2277         // Follow memory edges through memory accesses, phis and
2278         // narrow membars and push nodes on the stack. Once we hit
2279         // bottom memory, we pop element off the stack one at a
2280         // time, in reverse order, and move them to the right slice
2281         // by changing their memory edges.
2282         if ((n->is_Phi() && n->adr_type() != TypePtr::BOTTOM) || n->is_Mem() || n->adr_type() == TypeAryPtr::VALUES) {
2283           assert(!seen.test_set(n->_idx), "");
2284           // Uses (a load for instance) will need to be moved to the
2285           // right slice as well and will get a new memory state
2286           // that we don't know yet. The use could also be the
2287           // backedge of a loop. We put a place holder node between
2288           // the memory node and its uses. We replace that place
2289           // holder with the correct memory state once we know it,
2290           // i.e. when nodes are popped off the stack. Using the
2291           // place holder make the logic work in the presence of
2292           // loops.
2293           if (n->outcnt() > 1) {
2294             Node* place_holder = NULL;
2295             assert(!n->has_out_with(Op_Node), "");
2296             for (DUIterator k = n->outs(); n->has_out(k); k++) {
2297               Node* u = n->out(k);
2298               if (u != current && u->_idx < last) {
2299                 bool success = false;
2300                 for (uint l = 0; l < u->req(); l++) {
2301                   if (!stack.is_empty() && u == stack.node() && l == stack.index()) {
2302                     continue;
2303                   }
2304                   Node* in = u->in(l);
2305                   if (in == n) {
2306                     if (place_holder == NULL) {
2307                       place_holder = new Node(1);
2308                       place_holder->init_req(0, n);
2309                     }
2310                     igvn.replace_input_of(u, l, place_holder);
2311                     success = true;
2312                   }
2313                 }
2314                 if (success) {
2315                   --k;
2316                 }
2317               }
2318             }
2319           }
2320           if (n->is_Phi()) {
2321             stack.push(n, 1);
2322             n = n->in(1);
2323           } else if (n->is_Mem()) {
2324             stack.push(n, n->req());
2325             n = n->in(MemNode::Memory);
2326           } else {
2327             assert(n->is_Proj() && n->in(0)->Opcode() == Op_MemBarCPUOrder, "");
2328             stack.push(n, n->req());
2329             n = n->in(0)->in(TypeFunc::Memory);
2330           }
2331         } else {
2332           assert(n->adr_type() == TypePtr::BOTTOM || (n->Opcode() == Op_Node && n->_idx >= last) || (n->is_Proj() && n->in(0)->is_Initialize()), "");
2333           // Build a new MergeMem node to carry the new memory state
2334           // as we build it. IGVN should fold extraneous MergeMem
2335           // nodes.
2336           mm = MergeMemNode::make(n);
2337           igvn.register_new_node_with_optimizer(mm);
2338           while (stack.size() > 0) {
2339             Node* m = stack.node();
2340             uint idx = stack.index();
2341             if (m->is_Mem()) {
2342               // Move memory node to its new slice
2343               const TypePtr* adr_type = m->adr_type();
2344               int alias = get_alias_index(adr_type);
2345               Node* prev = mm->memory_at(alias);
2346               igvn.replace_input_of(m, MemNode::Memory, prev);
2347               mm->set_memory_at(alias, m);
2348             } else if (m->is_Phi()) {
2349               // We need as many new phis as there are new aliases
2350               igvn.replace_input_of(m, idx, mm);
2351               if (idx == m->req()-1) {
2352                 Node* r = m->in(0);
2353                 for (uint j = (uint)start_alias; j <= (uint)stop_alias; j++) {
2354                   const Type* adr_type = get_adr_type(j);
2355                   if (!adr_type->isa_aryptr() || !adr_type->is_aryptr()->elem()->isa_valuetype()) {
2356                     continue;
2357                   }
2358                   Node* phi = new PhiNode(r, Type::MEMORY, get_adr_type(j));
2359                   igvn.register_new_node_with_optimizer(phi);
2360                   for (uint k = 1; k < m->req(); k++) {
2361                     phi->init_req(k, m->in(k)->as_MergeMem()->memory_at(j));
2362                   }
2363                   mm->set_memory_at(j, phi);
2364                 }
2365                 Node* base_phi = new PhiNode(r, Type::MEMORY, TypePtr::BOTTOM);
2366                 igvn.register_new_node_with_optimizer(base_phi);
2367                 for (uint k = 1; k < m->req(); k++) {
2368                   base_phi->init_req(k, m->in(k)->as_MergeMem()->base_memory());
2369                 }
2370                 mm->set_base_memory(base_phi);
2371               }
2372             } else {
2373               // This is a MemBarCPUOrder node from
2374               // Parse::array_load()/Parse::array_store(), in the
2375               // branch that handles flattened arrays hidden under
2376               // an Object[] array. We also need one new membar per
2377               // new alias to keep the unknown access that the
2378               // membars protect properly ordered with accesses to
2379               // known flattened array.
2380               assert(m->is_Proj(), "projection expected");
2381               Node* ctrl = m->in(0)->in(TypeFunc::Control);
2382               igvn.replace_input_of(m->in(0), TypeFunc::Control, top());
2383               for (uint j = (uint)start_alias; j <= (uint)stop_alias; j++) {
2384                 const Type* adr_type = get_adr_type(j);
2385                 if (!adr_type->isa_aryptr() || !adr_type->is_aryptr()->elem()->isa_valuetype()) {
2386                   continue;
2387                 }
2388                 MemBarNode* mb = new MemBarCPUOrderNode(this, j, NULL);
2389                 igvn.register_new_node_with_optimizer(mb);
2390                 Node* mem = mm->memory_at(j);
2391                 mb->init_req(TypeFunc::Control, ctrl);
2392                 mb->init_req(TypeFunc::Memory, mem);
2393                 ctrl = new ProjNode(mb, TypeFunc::Control);
2394                 igvn.register_new_node_with_optimizer(ctrl);
2395                 mem = new ProjNode(mb, TypeFunc::Memory);
2396                 igvn.register_new_node_with_optimizer(mem);
2397                 mm->set_memory_at(j, mem);
2398               }
2399               igvn.replace_node(m->in(0)->as_Multi()->proj_out(TypeFunc::Control), ctrl);
2400             }
2401             if (idx < m->req()-1) {
2402               idx += 1;
2403               stack.set_index(idx);
2404               n = m->in(idx);
2405               break;
2406             }
2407             // Take care of place holder nodes
2408             if (m->has_out_with(Op_Node)) {
2409               Node* place_holder = m->find_out_with(Op_Node);
2410               if (place_holder != NULL) {
2411                 Node* mm_clone = mm->clone();
2412                 igvn.register_new_node_with_optimizer(mm_clone);
2413                 Node* hook = new Node(1);
2414                 hook->init_req(0, mm);
2415                 igvn.replace_node(place_holder, mm_clone);
2416                 hook->destruct();
2417               }
2418               assert(!m->has_out_with(Op_Node), "place holder should be gone now");
2419             }
2420             stack.pop();
2421           }
2422         }
2423       } while(stack.size() > 0);
2424       // Fix the memory state at the MergeMem we started from
2425       igvn.rehash_node_delayed(current);
2426       for (uint j = (uint)start_alias; j <= (uint)stop_alias; j++) {
2427         const Type* adr_type = get_adr_type(j);
2428         if (!adr_type->isa_aryptr() || !adr_type->is_aryptr()->elem()->isa_valuetype()) {
2429           continue;
2430         }
2431         current->set_memory_at(j, mm);
2432       }
2433       current->set_memory_at(index, current->base_memory());
2434     }
2435     igvn.optimize();
2436   }
2437   print_method(PHASE_SPLIT_VALUES_ARRAY, 2);
2438 }
2439 
2440 
2441 // StringOpts and late inlining of string methods
2442 void Compile::inline_string_calls(bool parse_time) {
2443   {
2444     // remove useless nodes to make the usage analysis simpler
2445     ResourceMark rm;
2446     PhaseRemoveUseless pru(initial_gvn(), for_igvn());
2447   }
2448 
2449   {
2450     ResourceMark rm;
2451     print_method(PHASE_BEFORE_STRINGOPTS, 3);
2452     PhaseStringOpts pso(initial_gvn(), for_igvn());
2453     print_method(PHASE_AFTER_STRINGOPTS, 3);
2454   }
2455 
2456   // now inline anything that we skipped the first time around
2457   if (!parse_time) {
2458     _late_inlines_pos = _late_inlines.length();
2459   }
2460 
2461   while (_string_late_inlines.length() > 0) {
2462     CallGenerator* cg = _string_late_inlines.pop();
2463     cg->do_late_inline();
2464     if (failing())  return;
2465   }
2466   _string_late_inlines.trunc_to(0);
2467 }
2468 
2469 // Late inlining of boxing methods
2470 void Compile::inline_boxing_calls(PhaseIterGVN& igvn) {
2471   if (_boxing_late_inlines.length() > 0) {
2472     assert(has_boxed_value(), "inconsistent");
2473 
2474     PhaseGVN* gvn = initial_gvn();
2475     set_inlining_incrementally(true);
2476 
2477     assert( igvn._worklist.size() == 0, "should be done with igvn" );
2478     for_igvn()->clear();
2479     gvn->replace_with(&igvn);
2480 
2481     _late_inlines_pos = _late_inlines.length();
2482 
2483     while (_boxing_late_inlines.length() > 0) {
2484       CallGenerator* cg = _boxing_late_inlines.pop();
2485       cg->do_late_inline();
2486       if (failing())  return;
2487     }
2488     _boxing_late_inlines.trunc_to(0);
2489 
2490     inline_incrementally_cleanup(igvn);
2491 
2492     set_inlining_incrementally(false);
2493   }
2494 }
2495 
2496 bool Compile::inline_incrementally_one() {
2497   assert(IncrementalInline, "incremental inlining should be on");
2498 
2499   TracePhase tp("incrementalInline_inline", &timers[_t_incrInline_inline]);
2500   set_inlining_progress(false);
2501   set_do_cleanup(false);
2502   int i = 0;
2503   for (; i <_late_inlines.length() && !inlining_progress(); i++) {
2504     CallGenerator* cg = _late_inlines.at(i);
2505     _late_inlines_pos = i+1;
2506     cg->do_late_inline();
2507     if (failing())  return false;
2508   }
2509   int j = 0;
2510   for (; i < _late_inlines.length(); i++, j++) {
2511     _late_inlines.at_put(j, _late_inlines.at(i));
2512   }
2513   _late_inlines.trunc_to(j);
2514   assert(inlining_progress() || _late_inlines.length() == 0, "");
2515 
2516   bool needs_cleanup = do_cleanup() || over_inlining_cutoff();
2517 
2518   set_inlining_progress(false);
2519   set_do_cleanup(false);
2520   return (_late_inlines.length() > 0) && !needs_cleanup;
2521 }
2522 
2523 void Compile::inline_incrementally_cleanup(PhaseIterGVN& igvn) {
2524   {
2525     TracePhase tp("incrementalInline_pru", &timers[_t_incrInline_pru]);
2526     ResourceMark rm;
2527     PhaseRemoveUseless pru(initial_gvn(), for_igvn());
2528   }
2529   {
2530     TracePhase tp("incrementalInline_igvn", &timers[_t_incrInline_igvn]);
2531     igvn = PhaseIterGVN(initial_gvn());
2532     igvn.optimize();
2533   }
2534 }
2535 
2536 // Perform incremental inlining until bound on number of live nodes is reached
2537 void Compile::inline_incrementally(PhaseIterGVN& igvn) {
2538   TracePhase tp("incrementalInline", &timers[_t_incrInline]);
2539 
2540   set_inlining_incrementally(true);
2541   uint low_live_nodes = 0;
2542 
2543   while (_late_inlines.length() > 0) {
2544     if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2545       if (low_live_nodes < (uint)LiveNodeCountInliningCutoff * 8 / 10) {
2546         TracePhase tp("incrementalInline_ideal", &timers[_t_incrInline_ideal]);
2547         // PhaseIdealLoop is expensive so we only try it once we are
2548         // out of live nodes and we only try it again if the previous
2549         // helped got the number of nodes down significantly
2550         PhaseIdealLoop::optimize(igvn, LoopOptsNone);
2551         if (failing())  return;
2552         low_live_nodes = live_nodes();
2553         _major_progress = true;
2554       }
2555 
2556       if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2557         break; // finish
2558       }
2559     }
2560 
2561     for_igvn()->clear();
2562     initial_gvn()->replace_with(&igvn);
2563 
2564     while (inline_incrementally_one()) {
2565       assert(!failing(), "inconsistent");
2566     }
2567 
2568     if (failing())  return;
2569 
2570     inline_incrementally_cleanup(igvn);
2571 
2572     if (failing())  return;
2573   }
2574   assert( igvn._worklist.size() == 0, "should be done with igvn" );
2575 
2576   if (_string_late_inlines.length() > 0) {
2577     assert(has_stringbuilder(), "inconsistent");
2578     for_igvn()->clear();
2579     initial_gvn()->replace_with(&igvn);
2580 
2581     inline_string_calls(false);
2582 
2583     if (failing())  return;
2584 
2585     inline_incrementally_cleanup(igvn);
2586   }
2587 
2588   set_inlining_incrementally(false);
2589 }
2590 
2591 
2592 bool Compile::optimize_loops(PhaseIterGVN& igvn, LoopOptsMode mode) {
2593   if(_loop_opts_cnt > 0) {
2594     debug_only( int cnt = 0; );
2595     while(major_progress() && (_loop_opts_cnt > 0)) {
2596       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2597       assert( cnt++ < 40, "infinite cycle in loop optimization" );
2598       PhaseIdealLoop::optimize(igvn, mode);
2599       _loop_opts_cnt--;
2600       if (failing())  return false;
2601       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
2602     }
2603   }
2604   return true;
2605 }
2606 
2607 // Remove edges from "root" to each SafePoint at a backward branch.
2608 // They were inserted during parsing (see add_safepoint()) to make
2609 // infinite loops without calls or exceptions visible to root, i.e.,
2610 // useful.
2611 void Compile::remove_root_to_sfpts_edges(PhaseIterGVN& igvn) {
2612   Node *r = root();
2613   if (r != NULL) {
2614     for (uint i = r->req(); i < r->len(); ++i) {
2615       Node *n = r->in(i);
2616       if (n != NULL && n->is_SafePoint()) {
2617         r->rm_prec(i);
2618         if (n->outcnt() == 0) {
2619           igvn.remove_dead_node(n);
2620         }
2621         --i;
2622       }
2623     }
2624   }
2625 }
2626 
2627 //------------------------------Optimize---------------------------------------
2628 // Given a graph, optimize it.
2629 void Compile::Optimize() {
2630   TracePhase tp("optimizer", &timers[_t_optimizer]);
2631 
2632 #ifndef PRODUCT
2633   if (_directive->BreakAtCompileOption) {
2634     BREAKPOINT;
2635   }
2636 
2637 #endif
2638 
2639   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
2640 #ifdef ASSERT
2641   bs->verify_gc_barriers(this, BarrierSetC2::BeforeOptimize);
2642 #endif
2643 
2644   ResourceMark rm;
2645 
2646   print_inlining_reinit();
2647 
2648   NOT_PRODUCT( verify_graph_edges(); )
2649 
2650   print_method(PHASE_AFTER_PARSING);
2651 
2652  {
2653   // Iterative Global Value Numbering, including ideal transforms
2654   // Initialize IterGVN with types and values from parse-time GVN
2655   PhaseIterGVN igvn(initial_gvn());
2656 #ifdef ASSERT
2657   _modified_nodes = new (comp_arena()) Unique_Node_List(comp_arena());
2658 #endif
2659   {
2660     TracePhase tp("iterGVN", &timers[_t_iterGVN]);
2661     igvn.optimize();
2662   }
2663 
2664   if (failing())  return;
2665 
2666   print_method(PHASE_ITER_GVN1, 2);
2667 
2668   inline_incrementally(igvn);
2669 
2670   print_method(PHASE_INCREMENTAL_INLINE, 2);
2671 
2672   if (failing())  return;
2673 
2674   if (eliminate_boxing()) {
2675     // Inline valueOf() methods now.
2676     inline_boxing_calls(igvn);
2677 
2678     if (AlwaysIncrementalInline) {
2679       inline_incrementally(igvn);
2680     }
2681 
2682     print_method(PHASE_INCREMENTAL_BOXING_INLINE, 2);
2683 
2684     if (failing())  return;
2685   }
2686 
2687   // Now that all inlining is over, cut edge from root to loop
2688   // safepoints
2689   remove_root_to_sfpts_edges(igvn);
2690 
2691   // Remove the speculative part of types and clean up the graph from
2692   // the extra CastPP nodes whose only purpose is to carry them. Do
2693   // that early so that optimizations are not disrupted by the extra
2694   // CastPP nodes.
2695   remove_speculative_types(igvn);
2696 
2697   // No more new expensive nodes will be added to the list from here
2698   // so keep only the actual candidates for optimizations.
2699   cleanup_expensive_nodes(igvn);
2700 
2701   if (!failing() && RenumberLiveNodes && live_nodes() + NodeLimitFudgeFactor < unique()) {
2702     Compile::TracePhase tp("", &timers[_t_renumberLive]);
2703     initial_gvn()->replace_with(&igvn);
2704     for_igvn()->clear();
2705     Unique_Node_List new_worklist(C->comp_arena());
2706     {
2707       ResourceMark rm;
2708       PhaseRenumberLive prl = PhaseRenumberLive(initial_gvn(), for_igvn(), &new_worklist);
2709     }
2710     set_for_igvn(&new_worklist);
2711     igvn = PhaseIterGVN(initial_gvn());
2712     igvn.optimize();
2713   }
2714 
2715   if (_value_type_nodes->size() > 0) {
2716     // Do this once all inlining is over to avoid getting inconsistent debug info
2717     process_value_types(igvn);
2718   }
2719 
2720   adjust_flattened_array_access_aliases(igvn);
2721 
2722   // Perform escape analysis
2723   if (_do_escape_analysis && ConnectionGraph::has_candidates(this)) {
2724     if (has_loops()) {
2725       // Cleanup graph (remove dead nodes).
2726       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2727       PhaseIdealLoop::optimize(igvn, LoopOptsNone);
2728       if (major_progress()) print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
2729       if (failing())  return;
2730     }
2731     ConnectionGraph::do_analysis(this, &igvn);
2732 
2733     if (failing())  return;
2734 
2735     // Optimize out fields loads from scalar replaceable allocations.
2736     igvn.optimize();
2737     print_method(PHASE_ITER_GVN_AFTER_EA, 2);
2738 
2739     if (failing())  return;
2740 
2741     if (congraph() != NULL && macro_count() > 0) {
2742       TracePhase tp("macroEliminate", &timers[_t_macroEliminate]);
2743       PhaseMacroExpand mexp(igvn);
2744       mexp.eliminate_macro_nodes();
2745       igvn.set_delay_transform(false);
2746 
2747       igvn.optimize();
2748       print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
2749 
2750       if (failing())  return;
2751     }
2752   }
2753 
2754   // Loop transforms on the ideal graph.  Range Check Elimination,
2755   // peeling, unrolling, etc.
2756 
2757   // Set loop opts counter
2758   if((_loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
2759     {
2760       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2761       PhaseIdealLoop::optimize(igvn, LoopOptsDefault);
2762       _loop_opts_cnt--;
2763       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP1, 2);
2764       if (failing())  return;
2765     }
2766     // Loop opts pass if partial peeling occurred in previous pass
2767     if(PartialPeelLoop && major_progress() && (_loop_opts_cnt > 0)) {
2768       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2769       PhaseIdealLoop::optimize(igvn, LoopOptsSkipSplitIf);
2770       _loop_opts_cnt--;
2771       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP2, 2);
2772       if (failing())  return;
2773     }
2774     // Loop opts pass for loop-unrolling before CCP
2775     if(major_progress() && (_loop_opts_cnt > 0)) {
2776       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2777       PhaseIdealLoop::optimize(igvn, LoopOptsSkipSplitIf);
2778       _loop_opts_cnt--;
2779       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP3, 2);
2780     }
2781     if (!failing()) {
2782       // Verify that last round of loop opts produced a valid graph
2783       TracePhase tp("idealLoopVerify", &timers[_t_idealLoopVerify]);
2784       PhaseIdealLoop::verify(igvn);
2785     }
2786   }
2787   if (failing())  return;
2788 
2789   // Conditional Constant Propagation;
2790   PhaseCCP ccp( &igvn );
2791   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
2792   {
2793     TracePhase tp("ccp", &timers[_t_ccp]);
2794     ccp.do_transform();
2795   }
2796   print_method(PHASE_CPP1, 2);
2797 
2798   assert( true, "Break here to ccp.dump_old2new_map()");
2799 
2800   // Iterative Global Value Numbering, including ideal transforms
2801   {
2802     TracePhase tp("iterGVN2", &timers[_t_iterGVN2]);
2803     igvn = ccp;
2804     igvn.optimize();
2805   }
2806   print_method(PHASE_ITER_GVN2, 2);
2807 
2808   if (failing())  return;
2809 
2810   // Loop transforms on the ideal graph.  Range Check Elimination,
2811   // peeling, unrolling, etc.
2812   if (!optimize_loops(igvn, LoopOptsDefault)) {
2813     return;
2814   }
2815 
2816   if (failing())  return;
2817 
2818   // Ensure that major progress is now clear
2819   C->clear_major_progress();
2820 
2821   {
2822     // Verify that all previous optimizations produced a valid graph
2823     // at least to this point, even if no loop optimizations were done.
2824     TracePhase tp("idealLoopVerify", &timers[_t_idealLoopVerify]);
2825     PhaseIdealLoop::verify(igvn);
2826   }
2827 
2828   if (range_check_cast_count() > 0) {
2829     // No more loop optimizations. Remove all range check dependent CastIINodes.
2830     C->remove_range_check_casts(igvn);
2831     igvn.optimize();
2832   }
2833 
2834 #ifdef ASSERT
2835   bs->verify_gc_barriers(this, BarrierSetC2::BeforeMacroExpand);
2836 #endif
2837 
2838   {
2839     TracePhase tp("macroExpand", &timers[_t_macroExpand]);
2840     PhaseMacroExpand  mex(igvn);
2841     if (mex.expand_macro_nodes()) {
2842       assert(failing(), "must bail out w/ explicit message");
2843       return;
2844     }
2845     print_method(PHASE_MACRO_EXPANSION, 2);
2846   }
2847 
2848 #ifdef ASSERT
2849   bs->verify_gc_barriers(this, BarrierSetC2::BeforeLateInsertion);
2850 #endif
2851 
2852   bs->barrier_insertion_phase(C, igvn);
2853   if (failing())  return;
2854 
2855   {
2856     TracePhase tp("barrierExpand", &timers[_t_barrierExpand]);
2857     if (bs->expand_barriers(this, igvn)) {
2858       assert(failing(), "must bail out w/ explicit message");
2859       return;
2860     }
2861     print_method(PHASE_BARRIER_EXPANSION, 2);
2862   }
2863 
2864   if (opaque4_count() > 0) {
2865     C->remove_opaque4_nodes(igvn);
2866     igvn.optimize();
2867   }
2868 
2869   DEBUG_ONLY( _modified_nodes = NULL; )
2870  } // (End scope of igvn; run destructor if necessary for asserts.)
2871 
2872  process_print_inlining();
2873  // A method with only infinite loops has no edges entering loops from root
2874  {
2875    TracePhase tp("graphReshape", &timers[_t_graphReshaping]);
2876    if (final_graph_reshaping()) {
2877      assert(failing(), "must bail out w/ explicit message");
2878      return;
2879    }
2880  }
2881 
2882  print_method(PHASE_OPTIMIZE_FINISHED, 2);
2883 }
2884 
2885 //------------------------------Code_Gen---------------------------------------
2886 // Given a graph, generate code for it
2887 void Compile::Code_Gen() {
2888   if (failing()) {
2889     return;
2890   }
2891 
2892   // Perform instruction selection.  You might think we could reclaim Matcher
2893   // memory PDQ, but actually the Matcher is used in generating spill code.
2894   // Internals of the Matcher (including some VectorSets) must remain live
2895   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
2896   // set a bit in reclaimed memory.
2897 
2898   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2899   // nodes.  Mapping is only valid at the root of each matched subtree.
2900   NOT_PRODUCT( verify_graph_edges(); )
2901 
2902   Matcher matcher;
2903   _matcher = &matcher;
2904   {
2905     TracePhase tp("matcher", &timers[_t_matcher]);
2906     matcher.match();
2907   }
2908   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2909   // nodes.  Mapping is only valid at the root of each matched subtree.
2910   NOT_PRODUCT( verify_graph_edges(); )
2911 
2912   // If you have too many nodes, or if matching has failed, bail out
2913   check_node_count(0, "out of nodes matching instructions");
2914   if (failing()) {
2915     return;
2916   }
2917 
2918   print_method(PHASE_MATCHING, 2);
2919 
2920   // Build a proper-looking CFG
2921   PhaseCFG cfg(node_arena(), root(), matcher);
2922   _cfg = &cfg;
2923   {
2924     TracePhase tp("scheduler", &timers[_t_scheduler]);
2925     bool success = cfg.do_global_code_motion();
2926     if (!success) {
2927       return;
2928     }
2929 
2930     print_method(PHASE_GLOBAL_CODE_MOTION, 2);
2931     NOT_PRODUCT( verify_graph_edges(); )
2932     debug_only( cfg.verify(); )
2933   }
2934 
2935   PhaseChaitin regalloc(unique(), cfg, matcher, false);
2936   _regalloc = &regalloc;
2937   {
2938     TracePhase tp("regalloc", &timers[_t_registerAllocation]);
2939     // Perform register allocation.  After Chaitin, use-def chains are
2940     // no longer accurate (at spill code) and so must be ignored.
2941     // Node->LRG->reg mappings are still accurate.
2942     _regalloc->Register_Allocate();
2943 
2944     // Bail out if the allocator builds too many nodes
2945     if (failing()) {
2946       return;
2947     }
2948   }
2949 
2950   // Prior to register allocation we kept empty basic blocks in case the
2951   // the allocator needed a place to spill.  After register allocation we
2952   // are not adding any new instructions.  If any basic block is empty, we
2953   // can now safely remove it.
2954   {
2955     TracePhase tp("blockOrdering", &timers[_t_blockOrdering]);
2956     cfg.remove_empty_blocks();
2957     if (do_freq_based_layout()) {
2958       PhaseBlockLayout layout(cfg);
2959     } else {
2960       cfg.set_loop_alignment();
2961     }
2962     cfg.fixup_flow();
2963   }
2964 
2965   // Apply peephole optimizations
2966   if( OptoPeephole ) {
2967     TracePhase tp("peephole", &timers[_t_peephole]);
2968     PhasePeephole peep( _regalloc, cfg);
2969     peep.do_transform();
2970   }
2971 
2972   // Do late expand if CPU requires this.
2973   if (Matcher::require_postalloc_expand) {
2974     TracePhase tp("postalloc_expand", &timers[_t_postalloc_expand]);
2975     cfg.postalloc_expand(_regalloc);
2976   }
2977 
2978   // Convert Nodes to instruction bits in a buffer
2979   {
2980     TraceTime tp("output", &timers[_t_output], CITime);
2981     Output();
2982   }
2983 
2984   print_method(PHASE_FINAL_CODE);
2985 
2986   // He's dead, Jim.
2987   _cfg     = (PhaseCFG*)((intptr_t)0xdeadbeef);
2988   _regalloc = (PhaseChaitin*)((intptr_t)0xdeadbeef);
2989 }
2990 
2991 
2992 //------------------------------dump_asm---------------------------------------
2993 // Dump formatted assembly
2994 #if defined(SUPPORT_OPTO_ASSEMBLY)
2995 void Compile::dump_asm_on(outputStream* st, int* pcs, uint pc_limit) {
2996 
2997   int pc_digits = 3; // #chars required for pc
2998   int sb_chars  = 3; // #chars for "start bundle" indicator
2999   int tab_size  = 8;
3000   if (pcs != NULL) {
3001     int max_pc = 0;
3002     for (uint i = 0; i < pc_limit; i++) {
3003       max_pc = (max_pc < pcs[i]) ? pcs[i] : max_pc;
3004     }
3005     pc_digits  = ((max_pc < 4096) ? 3 : ((max_pc < 65536) ? 4 : ((max_pc < 65536*256) ? 6 : 8))); // #chars required for pc
3006   }
3007   int prefix_len = ((pc_digits + sb_chars + tab_size - 1)/tab_size)*tab_size;
3008 
3009   bool cut_short = false;
3010   st->print_cr("#");
3011   st->print("#  ");  _tf->dump_on(st);  st->cr();
3012   st->print_cr("#");
3013 
3014   // For all blocks
3015   int pc = 0x0;                 // Program counter
3016   char starts_bundle = ' ';
3017   _regalloc->dump_frame();
3018 
3019   Node *n = NULL;
3020   for (uint i = 0; i < _cfg->number_of_blocks(); i++) {
3021     if (VMThread::should_terminate()) {
3022       cut_short = true;
3023       break;
3024     }
3025     Block* block = _cfg->get_block(i);
3026     if (block->is_connector() && !Verbose) {
3027       continue;
3028     }
3029     n = block->head();
3030     if ((pcs != NULL) && (n->_idx < pc_limit)) {
3031       pc = pcs[n->_idx];
3032       st->print("%*.*x", pc_digits, pc_digits, pc);
3033     }
3034     st->fill_to(prefix_len);
3035     block->dump_head(_cfg, st);
3036     if (block->is_connector()) {
3037       st->fill_to(prefix_len);
3038       st->print_cr("# Empty connector block");
3039     } else if (block->num_preds() == 2 && block->pred(1)->is_CatchProj() && block->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
3040       st->fill_to(prefix_len);
3041       st->print_cr("# Block is sole successor of call");
3042     }
3043 
3044     // For all instructions
3045     Node *delay = NULL;
3046     for (uint j = 0; j < block->number_of_nodes(); j++) {
3047       if (VMThread::should_terminate()) {
3048         cut_short = true;
3049         break;
3050       }
3051       n = block->get_node(j);
3052       if (valid_bundle_info(n)) {
3053         Bundle* bundle = node_bundling(n);
3054         if (bundle->used_in_unconditional_delay()) {
3055           delay = n;
3056           continue;
3057         }
3058         if (bundle->starts_bundle()) {
3059           starts_bundle = '+';
3060         }
3061       }
3062 
3063       if (WizardMode) {
3064         n->dump();
3065       }
3066 
3067       if( !n->is_Region() &&    // Dont print in the Assembly
3068           !n->is_Phi() &&       // a few noisely useless nodes
3069           !n->is_Proj() &&
3070           !n->is_MachTemp() &&
3071           !n->is_SafePointScalarObject() &&
3072           !n->is_Catch() &&     // Would be nice to print exception table targets
3073           !n->is_MergeMem() &&  // Not very interesting
3074           !n->is_top() &&       // Debug info table constants
3075           !(n->is_Con() && !n->is_Mach())// Debug info table constants
3076           ) {
3077         if ((pcs != NULL) && (n->_idx < pc_limit)) {
3078           pc = pcs[n->_idx];
3079           st->print("%*.*x", pc_digits, pc_digits, pc);
3080         } else {
3081           st->fill_to(pc_digits);
3082         }
3083         st->print(" %c ", starts_bundle);
3084         starts_bundle = ' ';
3085         st->fill_to(prefix_len);
3086         n->format(_regalloc, st);
3087         st->cr();
3088       }
3089 
3090       // If we have an instruction with a delay slot, and have seen a delay,
3091       // then back up and print it
3092       if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
3093         // Coverity finding - Explicit null dereferenced.
3094         guarantee(delay != NULL, "no unconditional delay instruction");
3095         if (WizardMode) delay->dump();
3096 
3097         if (node_bundling(delay)->starts_bundle())
3098           starts_bundle = '+';
3099         if ((pcs != NULL) && (n->_idx < pc_limit)) {
3100           pc = pcs[n->_idx];
3101           st->print("%*.*x", pc_digits, pc_digits, pc);
3102         } else {
3103           st->fill_to(pc_digits);
3104         }
3105         st->print(" %c ", starts_bundle);
3106         starts_bundle = ' ';
3107         st->fill_to(prefix_len);
3108         delay->format(_regalloc, st);
3109         st->cr();
3110         delay = NULL;
3111       }
3112 
3113       // Dump the exception table as well
3114       if( n->is_Catch() && (Verbose || WizardMode) ) {
3115         // Print the exception table for this offset
3116         _handler_table.print_subtable_for(pc);
3117       }
3118       st->bol(); // Make sure we start on a new line
3119     }
3120     st->cr(); // one empty line between blocks
3121     assert(cut_short || delay == NULL, "no unconditional delay branch");
3122   } // End of per-block dump
3123 
3124   if (cut_short)  st->print_cr("*** disassembly is cut short ***");
3125 }
3126 #endif
3127 
3128 //------------------------------Final_Reshape_Counts---------------------------
3129 // This class defines counters to help identify when a method
3130 // may/must be executed using hardware with only 24-bit precision.
3131 struct Final_Reshape_Counts : public StackObj {
3132   int  _call_count;             // count non-inlined 'common' calls
3133   int  _float_count;            // count float ops requiring 24-bit precision
3134   int  _double_count;           // count double ops requiring more precision
3135   int  _java_call_count;        // count non-inlined 'java' calls
3136   int  _inner_loop_count;       // count loops which need alignment
3137   VectorSet _visited;           // Visitation flags
3138   Node_List _tests;             // Set of IfNodes & PCTableNodes
3139 
3140   Final_Reshape_Counts() :
3141     _call_count(0), _float_count(0), _double_count(0),
3142     _java_call_count(0), _inner_loop_count(0),
3143     _visited( Thread::current()->resource_area() ) { }
3144 
3145   void inc_call_count  () { _call_count  ++; }
3146   void inc_float_count () { _float_count ++; }
3147   void inc_double_count() { _double_count++; }
3148   void inc_java_call_count() { _java_call_count++; }
3149   void inc_inner_loop_count() { _inner_loop_count++; }
3150 
3151   int  get_call_count  () const { return _call_count  ; }
3152   int  get_float_count () const { return _float_count ; }
3153   int  get_double_count() const { return _double_count; }
3154   int  get_java_call_count() const { return _java_call_count; }
3155   int  get_inner_loop_count() const { return _inner_loop_count; }
3156 };
3157 
3158 #ifdef ASSERT
3159 static bool oop_offset_is_sane(const TypeInstPtr* tp) {
3160   ciInstanceKlass *k = tp->klass()->as_instance_klass();
3161   // Make sure the offset goes inside the instance layout.
3162   return k->contains_field_offset(tp->offset());
3163   // Note that OffsetBot and OffsetTop are very negative.
3164 }
3165 #endif
3166 
3167 // Eliminate trivially redundant StoreCMs and accumulate their
3168 // precedence edges.
3169 void Compile::eliminate_redundant_card_marks(Node* n) {
3170   assert(n->Opcode() == Op_StoreCM, "expected StoreCM");
3171   if (n->in(MemNode::Address)->outcnt() > 1) {
3172     // There are multiple users of the same address so it might be
3173     // possible to eliminate some of the StoreCMs
3174     Node* mem = n->in(MemNode::Memory);
3175     Node* adr = n->in(MemNode::Address);
3176     Node* val = n->in(MemNode::ValueIn);
3177     Node* prev = n;
3178     bool done = false;
3179     // Walk the chain of StoreCMs eliminating ones that match.  As
3180     // long as it's a chain of single users then the optimization is
3181     // safe.  Eliminating partially redundant StoreCMs would require
3182     // cloning copies down the other paths.
3183     while (mem->Opcode() == Op_StoreCM && mem->outcnt() == 1 && !done) {
3184       if (adr == mem->in(MemNode::Address) &&
3185           val == mem->in(MemNode::ValueIn)) {
3186         // redundant StoreCM
3187         if (mem->req() > MemNode::OopStore) {
3188           // Hasn't been processed by this code yet.
3189           n->add_prec(mem->in(MemNode::OopStore));
3190         } else {
3191           // Already converted to precedence edge
3192           for (uint i = mem->req(); i < mem->len(); i++) {
3193             // Accumulate any precedence edges
3194             if (mem->in(i) != NULL) {
3195               n->add_prec(mem->in(i));
3196             }
3197           }
3198           // Everything above this point has been processed.
3199           done = true;
3200         }
3201         // Eliminate the previous StoreCM
3202         prev->set_req(MemNode::Memory, mem->in(MemNode::Memory));
3203         assert(mem->outcnt() == 0, "should be dead");
3204         mem->disconnect_inputs(NULL, this);
3205       } else {
3206         prev = mem;
3207       }
3208       mem = prev->in(MemNode::Memory);
3209     }
3210   }
3211 }
3212 
3213 
3214 //------------------------------final_graph_reshaping_impl----------------------
3215 // Implement items 1-5 from final_graph_reshaping below.
3216 void Compile::final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &frc) {
3217 
3218   if ( n->outcnt() == 0 ) return; // dead node
3219   uint nop = n->Opcode();
3220 
3221   // Check for 2-input instruction with "last use" on right input.
3222   // Swap to left input.  Implements item (2).
3223   if( n->req() == 3 &&          // two-input instruction
3224       n->in(1)->outcnt() > 1 && // left use is NOT a last use
3225       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
3226       n->in(2)->outcnt() == 1 &&// right use IS a last use
3227       !n->in(2)->is_Con() ) {   // right use is not a constant
3228     // Check for commutative opcode
3229     switch( nop ) {
3230     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddL:
3231     case Op_MaxI:  case Op_MinI:
3232     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulL:
3233     case Op_AndL:  case Op_XorL:  case Op_OrL:
3234     case Op_AndI:  case Op_XorI:  case Op_OrI: {
3235       // Move "last use" input to left by swapping inputs
3236       n->swap_edges(1, 2);
3237       break;
3238     }
3239     default:
3240       break;
3241     }
3242   }
3243 
3244 #ifdef ASSERT
3245   if( n->is_Mem() ) {
3246     int alias_idx = get_alias_index(n->as_Mem()->adr_type());
3247     assert( n->in(0) != NULL || alias_idx != Compile::AliasIdxRaw ||
3248             // oop will be recorded in oop map if load crosses safepoint
3249             n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
3250                              LoadNode::is_immutable_value(n->in(MemNode::Address))),
3251             "raw memory operations should have control edge");
3252   }
3253   if (n->is_MemBar()) {
3254     MemBarNode* mb = n->as_MemBar();
3255     if (mb->trailing_store() || mb->trailing_load_store()) {
3256       assert(mb->leading_membar()->trailing_membar() == mb, "bad membar pair");
3257       Node* mem = BarrierSet::barrier_set()->barrier_set_c2()->step_over_gc_barrier(mb->in(MemBarNode::Precedent));
3258       assert((mb->trailing_store() && mem->is_Store() && mem->as_Store()->is_release()) ||
3259              (mb->trailing_load_store() && mem->is_LoadStore()), "missing mem op");
3260     } else if (mb->leading()) {
3261       assert(mb->trailing_membar()->leading_membar() == mb, "bad membar pair");
3262     }
3263   }
3264 #endif
3265   // Count FPU ops and common calls, implements item (3)
3266   bool gc_handled = BarrierSet::barrier_set()->barrier_set_c2()->final_graph_reshaping(this, n, nop);
3267   if (!gc_handled) {
3268     final_graph_reshaping_main_switch(n, frc, nop);
3269   }
3270 
3271   // Collect CFG split points
3272   if (n->is_MultiBranch() && !n->is_RangeCheck()) {
3273     frc._tests.push(n);
3274   }
3275 }
3276 
3277 void Compile::final_graph_reshaping_main_switch(Node* n, Final_Reshape_Counts& frc, uint nop) {
3278   switch( nop ) {
3279   // Count all float operations that may use FPU
3280   case Op_AddF:
3281   case Op_SubF:
3282   case Op_MulF:
3283   case Op_DivF:
3284   case Op_NegF:
3285   case Op_ModF:
3286   case Op_ConvI2F:
3287   case Op_ConF:
3288   case Op_CmpF:
3289   case Op_CmpF3:
3290   // case Op_ConvL2F: // longs are split into 32-bit halves
3291     frc.inc_float_count();
3292     break;
3293 
3294   case Op_ConvF2D:
3295   case Op_ConvD2F:
3296     frc.inc_float_count();
3297     frc.inc_double_count();
3298     break;
3299 
3300   // Count all double operations that may use FPU
3301   case Op_AddD:
3302   case Op_SubD:
3303   case Op_MulD:
3304   case Op_DivD:
3305   case Op_NegD:
3306   case Op_ModD:
3307   case Op_ConvI2D:
3308   case Op_ConvD2I:
3309   // case Op_ConvL2D: // handled by leaf call
3310   // case Op_ConvD2L: // handled by leaf call
3311   case Op_ConD:
3312   case Op_CmpD:
3313   case Op_CmpD3:
3314     frc.inc_double_count();
3315     break;
3316   case Op_Opaque1:              // Remove Opaque Nodes before matching
3317   case Op_Opaque2:              // Remove Opaque Nodes before matching
3318   case Op_Opaque3:
3319     n->subsume_by(n->in(1), this);
3320     break;
3321   case Op_CallStaticJava:
3322   case Op_CallJava:
3323   case Op_CallDynamicJava:
3324     frc.inc_java_call_count(); // Count java call site;
3325   case Op_CallRuntime:
3326   case Op_CallLeaf:
3327   case Op_CallLeafNoFP: {
3328     assert (n->is_Call(), "");
3329     CallNode *call = n->as_Call();
3330     // Count call sites where the FP mode bit would have to be flipped.
3331     // Do not count uncommon runtime calls:
3332     // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
3333     // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
3334     if (!call->is_CallStaticJava() || !call->as_CallStaticJava()->_name) {
3335       frc.inc_call_count();   // Count the call site
3336     } else {                  // See if uncommon argument is shared
3337       Node *n = call->in(TypeFunc::Parms);
3338       int nop = n->Opcode();
3339       // Clone shared simple arguments to uncommon calls, item (1).
3340       if (n->outcnt() > 1 &&
3341           !n->is_Proj() &&
3342           nop != Op_CreateEx &&
3343           nop != Op_CheckCastPP &&
3344           nop != Op_DecodeN &&
3345           nop != Op_DecodeNKlass &&
3346           !n->is_Mem() &&
3347           !n->is_Phi()) {
3348         Node *x = n->clone();
3349         call->set_req(TypeFunc::Parms, x);
3350       }
3351     }
3352     break;
3353   }
3354 
3355   case Op_StoreD:
3356   case Op_LoadD:
3357   case Op_LoadD_unaligned:
3358     frc.inc_double_count();
3359     goto handle_mem;
3360   case Op_StoreF:
3361   case Op_LoadF:
3362     frc.inc_float_count();
3363     goto handle_mem;
3364 
3365   case Op_StoreCM:
3366     {
3367       // Convert OopStore dependence into precedence edge
3368       Node* prec = n->in(MemNode::OopStore);
3369       n->del_req(MemNode::OopStore);
3370       n->add_prec(prec);
3371       eliminate_redundant_card_marks(n);
3372     }
3373 
3374     // fall through
3375 
3376   case Op_StoreB:
3377   case Op_StoreC:
3378   case Op_StorePConditional:
3379   case Op_StoreI:
3380   case Op_StoreL:
3381   case Op_StoreIConditional:
3382   case Op_StoreLConditional:
3383   case Op_CompareAndSwapB:
3384   case Op_CompareAndSwapS:
3385   case Op_CompareAndSwapI:
3386   case Op_CompareAndSwapL:
3387   case Op_CompareAndSwapP:
3388   case Op_CompareAndSwapN:
3389   case Op_WeakCompareAndSwapB:
3390   case Op_WeakCompareAndSwapS:
3391   case Op_WeakCompareAndSwapI:
3392   case Op_WeakCompareAndSwapL:
3393   case Op_WeakCompareAndSwapP:
3394   case Op_WeakCompareAndSwapN:
3395   case Op_CompareAndExchangeB:
3396   case Op_CompareAndExchangeS:
3397   case Op_CompareAndExchangeI:
3398   case Op_CompareAndExchangeL:
3399   case Op_CompareAndExchangeP:
3400   case Op_CompareAndExchangeN:
3401   case Op_GetAndAddS:
3402   case Op_GetAndAddB:
3403   case Op_GetAndAddI:
3404   case Op_GetAndAddL:
3405   case Op_GetAndSetS:
3406   case Op_GetAndSetB:
3407   case Op_GetAndSetI:
3408   case Op_GetAndSetL:
3409   case Op_GetAndSetP:
3410   case Op_GetAndSetN:
3411   case Op_StoreP:
3412   case Op_StoreN:
3413   case Op_StoreNKlass:
3414   case Op_LoadB:
3415   case Op_LoadUB:
3416   case Op_LoadUS:
3417   case Op_LoadI:
3418   case Op_LoadKlass:
3419   case Op_LoadNKlass:
3420   case Op_LoadL:
3421   case Op_LoadL_unaligned:
3422   case Op_LoadPLocked:
3423   case Op_LoadP:
3424   case Op_LoadN:
3425   case Op_LoadRange:
3426   case Op_LoadS: {
3427   handle_mem:
3428 #ifdef ASSERT
3429     if( VerifyOptoOopOffsets ) {
3430       MemNode* mem  = n->as_Mem();
3431       // Check to see if address types have grounded out somehow.
3432       const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
3433       assert( !tp || oop_offset_is_sane(tp), "" );
3434     }
3435 #endif
3436     if (EnableValhalla &&
3437         ((nop == Op_LoadKlass && ((LoadKlassNode*)n)->clear_prop_bits()) ||
3438          (nop == Op_LoadNKlass && ((LoadNKlassNode*)n)->clear_prop_bits()))) {
3439       const TypeKlassPtr* tk = n->bottom_type()->make_ptr()->is_klassptr();
3440       assert(!tk->klass_is_exact(), "should have been folded");
3441       assert(n->as_Mem()->adr_type()->offset() == oopDesc::klass_offset_in_bytes(), "unexpected LoadKlass");
3442       if (tk->klass()->can_be_value_array_klass()) {
3443         // Array load klass needs to filter out property bits (but not
3444         // GetNullFreePropertyNode or GetFlattenedPropertyNode which
3445         // needs to extract the storage property bits)
3446         uint last = unique();
3447         Node* pointer = NULL;
3448         if (nop == Op_LoadKlass) {
3449           Node* cast = new CastP2XNode(NULL, n);
3450           Node* masked = new LShiftXNode(cast, new ConINode(TypeInt::make(oopDesc::storage_props_nof_bits)));
3451           masked = new RShiftXNode(masked, new ConINode(TypeInt::make(oopDesc::storage_props_nof_bits)));
3452           pointer = new CastX2PNode(masked);
3453           pointer = new CheckCastPPNode(NULL, pointer, n->bottom_type());
3454         } else {
3455           Node* cast = new CastN2INode(n);
3456           Node* masked = new AndINode(cast, new ConINode(TypeInt::make(oopDesc::compressed_klass_mask())));
3457           pointer = new CastI2NNode(masked, n->bottom_type());
3458         }
3459         for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3460           Node* u = n->fast_out(i);
3461           if (u->_idx < last && u->Opcode() != Op_GetNullFreeProperty && u->Opcode() != Op_GetFlattenedProperty) {
3462             // If user is a comparison with a klass that can't be a value type
3463             // array klass, we don't need to clear the storage property bits.
3464             Node* cmp = (u->is_DecodeNKlass() && u->outcnt() == 1) ? u->unique_out() : u;
3465             if (cmp->is_Cmp()) {
3466               const TypeKlassPtr* kp1 = cmp->in(1)->bottom_type()->make_ptr()->isa_klassptr();
3467               const TypeKlassPtr* kp2 = cmp->in(2)->bottom_type()->make_ptr()->isa_klassptr();
3468               if ((kp1 != NULL && !kp1->klass()->can_be_value_array_klass()) ||
3469                   (kp2 != NULL && !kp2->klass()->can_be_value_array_klass())) {
3470                 continue;
3471               }
3472             }
3473             int nb = u->replace_edge(n, pointer);
3474             --i, imax -= nb;
3475           }
3476         }
3477       }
3478     }
3479     break;
3480   }
3481 
3482   case Op_AddP: {               // Assert sane base pointers
3483     Node *addp = n->in(AddPNode::Address);
3484     assert( !addp->is_AddP() ||
3485             addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
3486             addp->in(AddPNode::Base) == n->in(AddPNode::Base),
3487             "Base pointers must match (addp %u)", addp->_idx );
3488 #ifdef _LP64
3489     if ((UseCompressedOops || UseCompressedClassPointers) &&
3490         addp->Opcode() == Op_ConP &&
3491         addp == n->in(AddPNode::Base) &&
3492         n->in(AddPNode::Offset)->is_Con()) {
3493       // If the transformation of ConP to ConN+DecodeN is beneficial depends
3494       // on the platform and on the compressed oops mode.
3495       // Use addressing with narrow klass to load with offset on x86.
3496       // Some platforms can use the constant pool to load ConP.
3497       // Do this transformation here since IGVN will convert ConN back to ConP.
3498       const Type* t = addp->bottom_type();
3499       bool is_oop   = t->isa_oopptr() != NULL;
3500       bool is_klass = t->isa_klassptr() != NULL;
3501 
3502       if ((is_oop   && Matcher::const_oop_prefer_decode()  ) ||
3503           (is_klass && Matcher::const_klass_prefer_decode())) {
3504         Node* nn = NULL;
3505 
3506         int op = is_oop ? Op_ConN : Op_ConNKlass;
3507 
3508         // Look for existing ConN node of the same exact type.
3509         Node* r  = root();
3510         uint cnt = r->outcnt();
3511         for (uint i = 0; i < cnt; i++) {
3512           Node* m = r->raw_out(i);
3513           if (m!= NULL && m->Opcode() == op &&
3514               m->bottom_type()->make_ptr() == t) {
3515             nn = m;
3516             break;
3517           }
3518         }
3519         if (nn != NULL) {
3520           // Decode a narrow oop to match address
3521           // [R12 + narrow_oop_reg<<3 + offset]
3522           if (is_oop) {
3523             nn = new DecodeNNode(nn, t);
3524           } else {
3525             nn = new DecodeNKlassNode(nn, t);
3526           }
3527           // Check for succeeding AddP which uses the same Base.
3528           // Otherwise we will run into the assertion above when visiting that guy.
3529           for (uint i = 0; i < n->outcnt(); ++i) {
3530             Node *out_i = n->raw_out(i);
3531             if (out_i && out_i->is_AddP() && out_i->in(AddPNode::Base) == addp) {
3532               out_i->set_req(AddPNode::Base, nn);
3533 #ifdef ASSERT
3534               for (uint j = 0; j < out_i->outcnt(); ++j) {
3535                 Node *out_j = out_i->raw_out(j);
3536                 assert(out_j == NULL || !out_j->is_AddP() || out_j->in(AddPNode::Base) != addp,
3537                        "more than 2 AddP nodes in a chain (out_j %u)", out_j->_idx);
3538               }
3539 #endif
3540             }
3541           }
3542           n->set_req(AddPNode::Base, nn);
3543           n->set_req(AddPNode::Address, nn);
3544           if (addp->outcnt() == 0) {
3545             addp->disconnect_inputs(NULL, this);
3546           }
3547         }
3548       }
3549     }
3550 #endif
3551     // platform dependent reshaping of the address expression
3552     reshape_address(n->as_AddP());
3553     break;
3554   }
3555 
3556   case Op_CastPP: {
3557     // Remove CastPP nodes to gain more freedom during scheduling but
3558     // keep the dependency they encode as control or precedence edges
3559     // (if control is set already) on memory operations. Some CastPP
3560     // nodes don't have a control (don't carry a dependency): skip
3561     // those.
3562     if (n->in(0) != NULL) {
3563       ResourceMark rm;
3564       Unique_Node_List wq;
3565       wq.push(n);
3566       for (uint next = 0; next < wq.size(); ++next) {
3567         Node *m = wq.at(next);
3568         for (DUIterator_Fast imax, i = m->fast_outs(imax); i < imax; i++) {
3569           Node* use = m->fast_out(i);
3570           if (use->is_Mem() || use->is_EncodeNarrowPtr()) {
3571             use->ensure_control_or_add_prec(n->in(0));
3572           } else {
3573             switch(use->Opcode()) {
3574             case Op_AddP:
3575             case Op_DecodeN:
3576             case Op_DecodeNKlass:
3577             case Op_CheckCastPP:
3578             case Op_CastPP:
3579               wq.push(use);
3580               break;
3581             }
3582           }
3583         }
3584       }
3585     }
3586     const bool is_LP64 = LP64_ONLY(true) NOT_LP64(false);
3587     if (is_LP64 && n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
3588       Node* in1 = n->in(1);
3589       const Type* t = n->bottom_type();
3590       Node* new_in1 = in1->clone();
3591       new_in1->as_DecodeN()->set_type(t);
3592 
3593       if (!Matcher::narrow_oop_use_complex_address()) {
3594         //
3595         // x86, ARM and friends can handle 2 adds in addressing mode
3596         // and Matcher can fold a DecodeN node into address by using
3597         // a narrow oop directly and do implicit NULL check in address:
3598         //
3599         // [R12 + narrow_oop_reg<<3 + offset]
3600         // NullCheck narrow_oop_reg
3601         //
3602         // On other platforms (Sparc) we have to keep new DecodeN node and
3603         // use it to do implicit NULL check in address:
3604         //
3605         // decode_not_null narrow_oop_reg, base_reg
3606         // [base_reg + offset]
3607         // NullCheck base_reg
3608         //
3609         // Pin the new DecodeN node to non-null path on these platform (Sparc)
3610         // to keep the information to which NULL check the new DecodeN node
3611         // corresponds to use it as value in implicit_null_check().
3612         //
3613         new_in1->set_req(0, n->in(0));
3614       }
3615 
3616       n->subsume_by(new_in1, this);
3617       if (in1->outcnt() == 0) {
3618         in1->disconnect_inputs(NULL, this);
3619       }
3620     } else {
3621       n->subsume_by(n->in(1), this);
3622       if (n->outcnt() == 0) {
3623         n->disconnect_inputs(NULL, this);
3624       }
3625     }
3626     break;
3627   }
3628 #ifdef _LP64
3629   case Op_CmpP:
3630     // Do this transformation here to preserve CmpPNode::sub() and
3631     // other TypePtr related Ideal optimizations (for example, ptr nullness).
3632     if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
3633       Node* in1 = n->in(1);
3634       Node* in2 = n->in(2);
3635       if (!in1->is_DecodeNarrowPtr()) {
3636         in2 = in1;
3637         in1 = n->in(2);
3638       }
3639       assert(in1->is_DecodeNarrowPtr(), "sanity");
3640 
3641       Node* new_in2 = NULL;
3642       if (in2->is_DecodeNarrowPtr()) {
3643         assert(in2->Opcode() == in1->Opcode(), "must be same node type");
3644         new_in2 = in2->in(1);
3645       } else if (in2->Opcode() == Op_ConP) {
3646         const Type* t = in2->bottom_type();
3647         if (t == TypePtr::NULL_PTR) {
3648           assert(in1->is_DecodeN(), "compare klass to null?");
3649           // Don't convert CmpP null check into CmpN if compressed
3650           // oops implicit null check is not generated.
3651           // This will allow to generate normal oop implicit null check.
3652           if (Matcher::gen_narrow_oop_implicit_null_checks())
3653             new_in2 = ConNode::make(TypeNarrowOop::NULL_PTR);
3654           //
3655           // This transformation together with CastPP transformation above
3656           // will generated code for implicit NULL checks for compressed oops.
3657           //
3658           // The original code after Optimize()
3659           //
3660           //    LoadN memory, narrow_oop_reg
3661           //    decode narrow_oop_reg, base_reg
3662           //    CmpP base_reg, NULL
3663           //    CastPP base_reg // NotNull
3664           //    Load [base_reg + offset], val_reg
3665           //
3666           // after these transformations will be
3667           //
3668           //    LoadN memory, narrow_oop_reg
3669           //    CmpN narrow_oop_reg, NULL
3670           //    decode_not_null narrow_oop_reg, base_reg
3671           //    Load [base_reg + offset], val_reg
3672           //
3673           // and the uncommon path (== NULL) will use narrow_oop_reg directly
3674           // since narrow oops can be used in debug info now (see the code in
3675           // final_graph_reshaping_walk()).
3676           //
3677           // At the end the code will be matched to
3678           // on x86:
3679           //
3680           //    Load_narrow_oop memory, narrow_oop_reg
3681           //    Load [R12 + narrow_oop_reg<<3 + offset], val_reg
3682           //    NullCheck narrow_oop_reg
3683           //
3684           // and on sparc:
3685           //
3686           //    Load_narrow_oop memory, narrow_oop_reg
3687           //    decode_not_null narrow_oop_reg, base_reg
3688           //    Load [base_reg + offset], val_reg
3689           //    NullCheck base_reg
3690           //
3691         } else if (t->isa_oopptr()) {
3692           new_in2 = ConNode::make(t->make_narrowoop());
3693         } else if (t->isa_klassptr()) {
3694           new_in2 = ConNode::make(t->make_narrowklass());
3695         }
3696       }
3697       if (new_in2 != NULL) {
3698         Node* cmpN = new CmpNNode(in1->in(1), new_in2);
3699         n->subsume_by(cmpN, this);
3700         if (in1->outcnt() == 0) {
3701           in1->disconnect_inputs(NULL, this);
3702         }
3703         if (in2->outcnt() == 0) {
3704           in2->disconnect_inputs(NULL, this);
3705         }
3706       }
3707     }
3708     break;
3709 
3710   case Op_DecodeN:
3711   case Op_DecodeNKlass:
3712     assert(!n->in(1)->is_EncodeNarrowPtr(), "should be optimized out");
3713     // DecodeN could be pinned when it can't be fold into
3714     // an address expression, see the code for Op_CastPP above.
3715     assert(n->in(0) == NULL || (UseCompressedOops && !Matcher::narrow_oop_use_complex_address()), "no control");
3716     break;
3717 
3718   case Op_EncodeP:
3719   case Op_EncodePKlass: {
3720     Node* in1 = n->in(1);
3721     if (in1->is_DecodeNarrowPtr()) {
3722       n->subsume_by(in1->in(1), this);
3723     } else if (in1->Opcode() == Op_ConP) {
3724       const Type* t = in1->bottom_type();
3725       if (t == TypePtr::NULL_PTR) {
3726         assert(t->isa_oopptr(), "null klass?");
3727         n->subsume_by(ConNode::make(TypeNarrowOop::NULL_PTR), this);
3728       } else if (t->isa_oopptr()) {
3729         n->subsume_by(ConNode::make(t->make_narrowoop()), this);
3730       } else if (t->isa_klassptr()) {
3731         n->subsume_by(ConNode::make(t->make_narrowklass()), this);
3732       }
3733     }
3734     if (in1->outcnt() == 0) {
3735       in1->disconnect_inputs(NULL, this);
3736     }
3737     break;
3738   }
3739 
3740   case Op_Proj: {
3741     if (OptimizeStringConcat) {
3742       ProjNode* p = n->as_Proj();
3743       if (p->_is_io_use) {
3744         // Separate projections were used for the exception path which
3745         // are normally removed by a late inline.  If it wasn't inlined
3746         // then they will hang around and should just be replaced with
3747         // the original one.
3748         Node* proj = NULL;
3749         // Replace with just one
3750         for (SimpleDUIterator i(p->in(0)); i.has_next(); i.next()) {
3751           Node *use = i.get();
3752           if (use->is_Proj() && p != use && use->as_Proj()->_con == p->_con) {
3753             proj = use;
3754             break;
3755           }
3756         }
3757         assert(proj != NULL || p->_con == TypeFunc::I_O, "io may be dropped at an infinite loop");
3758         if (proj != NULL) {
3759           p->subsume_by(proj, this);
3760         }
3761       }
3762     }
3763     break;
3764   }
3765 
3766   case Op_Phi:
3767     if (n->as_Phi()->bottom_type()->isa_narrowoop() || n->as_Phi()->bottom_type()->isa_narrowklass()) {
3768       // The EncodeP optimization may create Phi with the same edges
3769       // for all paths. It is not handled well by Register Allocator.
3770       Node* unique_in = n->in(1);
3771       assert(unique_in != NULL, "");
3772       uint cnt = n->req();
3773       for (uint i = 2; i < cnt; i++) {
3774         Node* m = n->in(i);
3775         assert(m != NULL, "");
3776         if (unique_in != m)
3777           unique_in = NULL;
3778       }
3779       if (unique_in != NULL) {
3780         n->subsume_by(unique_in, this);
3781       }
3782     }
3783     break;
3784 
3785 #endif
3786 
3787 #ifdef ASSERT
3788   case Op_CastII:
3789     // Verify that all range check dependent CastII nodes were removed.
3790     if (n->isa_CastII()->has_range_check()) {
3791       n->dump(3);
3792       assert(false, "Range check dependent CastII node was not removed");
3793     }
3794     break;
3795 #endif
3796 
3797   case Op_ModI:
3798     if (UseDivMod) {
3799       // Check if a%b and a/b both exist
3800       Node* d = n->find_similar(Op_DivI);
3801       if (d) {
3802         // Replace them with a fused divmod if supported
3803         if (Matcher::has_match_rule(Op_DivModI)) {
3804           DivModINode* divmod = DivModINode::make(n);
3805           d->subsume_by(divmod->div_proj(), this);
3806           n->subsume_by(divmod->mod_proj(), this);
3807         } else {
3808           // replace a%b with a-((a/b)*b)
3809           Node* mult = new MulINode(d, d->in(2));
3810           Node* sub  = new SubINode(d->in(1), mult);
3811           n->subsume_by(sub, this);
3812         }
3813       }
3814     }
3815     break;
3816 
3817   case Op_ModL:
3818     if (UseDivMod) {
3819       // Check if a%b and a/b both exist
3820       Node* d = n->find_similar(Op_DivL);
3821       if (d) {
3822         // Replace them with a fused divmod if supported
3823         if (Matcher::has_match_rule(Op_DivModL)) {
3824           DivModLNode* divmod = DivModLNode::make(n);
3825           d->subsume_by(divmod->div_proj(), this);
3826           n->subsume_by(divmod->mod_proj(), this);
3827         } else {
3828           // replace a%b with a-((a/b)*b)
3829           Node* mult = new MulLNode(d, d->in(2));
3830           Node* sub  = new SubLNode(d->in(1), mult);
3831           n->subsume_by(sub, this);
3832         }
3833       }
3834     }
3835     break;
3836 
3837   case Op_LoadVector:
3838   case Op_StoreVector:
3839     break;
3840 
3841   case Op_AddReductionVI:
3842   case Op_AddReductionVL:
3843   case Op_AddReductionVF:
3844   case Op_AddReductionVD:
3845   case Op_MulReductionVI:
3846   case Op_MulReductionVL:
3847   case Op_MulReductionVF:
3848   case Op_MulReductionVD:
3849   case Op_MinReductionV:
3850   case Op_MaxReductionV:
3851     break;
3852 
3853   case Op_PackB:
3854   case Op_PackS:
3855   case Op_PackI:
3856   case Op_PackF:
3857   case Op_PackL:
3858   case Op_PackD:
3859     if (n->req()-1 > 2) {
3860       // Replace many operand PackNodes with a binary tree for matching
3861       PackNode* p = (PackNode*) n;
3862       Node* btp = p->binary_tree_pack(1, n->req());
3863       n->subsume_by(btp, this);
3864     }
3865     break;
3866   case Op_Loop:
3867   case Op_CountedLoop:
3868   case Op_OuterStripMinedLoop:
3869     if (n->as_Loop()->is_inner_loop()) {
3870       frc.inc_inner_loop_count();
3871     }
3872     n->as_Loop()->verify_strip_mined(0);
3873     break;
3874   case Op_LShiftI:
3875   case Op_RShiftI:
3876   case Op_URShiftI:
3877   case Op_LShiftL:
3878   case Op_RShiftL:
3879   case Op_URShiftL:
3880     if (Matcher::need_masked_shift_count) {
3881       // The cpu's shift instructions don't restrict the count to the
3882       // lower 5/6 bits. We need to do the masking ourselves.
3883       Node* in2 = n->in(2);
3884       juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
3885       const TypeInt* t = in2->find_int_type();
3886       if (t != NULL && t->is_con()) {
3887         juint shift = t->get_con();
3888         if (shift > mask) { // Unsigned cmp
3889           n->set_req(2, ConNode::make(TypeInt::make(shift & mask)));
3890         }
3891       } else {
3892         if (t == NULL || t->_lo < 0 || t->_hi > (int)mask) {
3893           Node* shift = new AndINode(in2, ConNode::make(TypeInt::make(mask)));
3894           n->set_req(2, shift);
3895         }
3896       }
3897       if (in2->outcnt() == 0) { // Remove dead node
3898         in2->disconnect_inputs(NULL, this);
3899       }
3900     }
3901     break;
3902   case Op_MemBarStoreStore:
3903   case Op_MemBarRelease:
3904     // Break the link with AllocateNode: it is no longer useful and
3905     // confuses register allocation.
3906     if (n->req() > MemBarNode::Precedent) {
3907       n->set_req(MemBarNode::Precedent, top());
3908     }
3909     break;
3910   case Op_MemBarAcquire: {
3911     if (n->as_MemBar()->trailing_load() && n->req() > MemBarNode::Precedent) {
3912       // At parse time, the trailing MemBarAcquire for a volatile load
3913       // is created with an edge to the load. After optimizations,
3914       // that input may be a chain of Phis. If those phis have no
3915       // other use, then the MemBarAcquire keeps them alive and
3916       // register allocation can be confused.
3917       ResourceMark rm;
3918       Unique_Node_List wq;
3919       wq.push(n->in(MemBarNode::Precedent));
3920       n->set_req(MemBarNode::Precedent, top());
3921       while (wq.size() > 0) {
3922         Node* m = wq.pop();
3923         if (m->outcnt() == 0) {
3924           for (uint j = 0; j < m->req(); j++) {
3925             Node* in = m->in(j);
3926             if (in != NULL) {
3927               wq.push(in);
3928             }
3929           }
3930           m->disconnect_inputs(NULL, this);
3931         }
3932       }
3933     }
3934     break;
3935   }
3936   case Op_RangeCheck: {
3937     RangeCheckNode* rc = n->as_RangeCheck();
3938     Node* iff = new IfNode(rc->in(0), rc->in(1), rc->_prob, rc->_fcnt);
3939     n->subsume_by(iff, this);
3940     frc._tests.push(iff);
3941     break;
3942   }
3943   case Op_ConvI2L: {
3944     if (!Matcher::convi2l_type_required) {
3945       // Code generation on some platforms doesn't need accurate
3946       // ConvI2L types. Widening the type can help remove redundant
3947       // address computations.
3948       n->as_Type()->set_type(TypeLong::INT);
3949       ResourceMark rm;
3950       Unique_Node_List wq;
3951       wq.push(n);
3952       for (uint next = 0; next < wq.size(); next++) {
3953         Node *m = wq.at(next);
3954 
3955         for(;;) {
3956           // Loop over all nodes with identical inputs edges as m
3957           Node* k = m->find_similar(m->Opcode());
3958           if (k == NULL) {
3959             break;
3960           }
3961           // Push their uses so we get a chance to remove node made
3962           // redundant
3963           for (DUIterator_Fast imax, i = k->fast_outs(imax); i < imax; i++) {
3964             Node* u = k->fast_out(i);
3965             if (u->Opcode() == Op_LShiftL ||
3966                 u->Opcode() == Op_AddL ||
3967                 u->Opcode() == Op_SubL ||
3968                 u->Opcode() == Op_AddP) {
3969               wq.push(u);
3970             }
3971           }
3972           // Replace all nodes with identical edges as m with m
3973           k->subsume_by(m, this);
3974         }
3975       }
3976     }
3977     break;
3978   }
3979   case Op_CmpUL: {
3980     if (!Matcher::has_match_rule(Op_CmpUL)) {
3981       // No support for unsigned long comparisons
3982       ConINode* sign_pos = new ConINode(TypeInt::make(BitsPerLong - 1));
3983       Node* sign_bit_mask = new RShiftLNode(n->in(1), sign_pos);
3984       Node* orl = new OrLNode(n->in(1), sign_bit_mask);
3985       ConLNode* remove_sign_mask = new ConLNode(TypeLong::make(max_jlong));
3986       Node* andl = new AndLNode(orl, remove_sign_mask);
3987       Node* cmp = new CmpLNode(andl, n->in(2));
3988       n->subsume_by(cmp, this);
3989     }
3990     break;
3991   }
3992 #ifdef ASSERT
3993   case Op_ValueTypePtr:
3994   case Op_ValueType: {
3995     n->dump(-1);
3996     assert(false, "value type node was not removed");
3997     break;
3998   }
3999 #endif
4000   case Op_GetNullFreeProperty:
4001   case Op_GetFlattenedProperty: {
4002     // Extract the null free bits
4003     uint last = unique();
4004     Node* null_free = NULL;
4005     int bit = nop == Op_GetNullFreeProperty ? ArrayStorageProperties::null_free_bit : ArrayStorageProperties::flattened_bit;
4006     if (n->in(1)->Opcode() == Op_LoadKlass) {
4007       Node* cast = new CastP2XNode(NULL, n->in(1));
4008       null_free = new AndLNode(cast, new ConLNode(TypeLong::make(((jlong)1)<<(oopDesc::wide_storage_props_shift + bit))));
4009     } else {
4010       assert(n->in(1)->Opcode() == Op_LoadNKlass, "not a compressed klass?");
4011       Node* cast = new CastN2INode(n->in(1));
4012       null_free = new AndINode(cast, new ConINode(TypeInt::make(1<<(oopDesc::narrow_storage_props_shift + bit))));
4013     }
4014     n->subsume_by(null_free, this);
4015     break;
4016   }
4017   default:
4018     assert(!n->is_Call(), "");
4019     assert(!n->is_Mem(), "");
4020     assert(nop != Op_ProfileBoolean, "should be eliminated during IGVN");
4021     break;
4022   }
4023 }
4024 
4025 //------------------------------final_graph_reshaping_walk---------------------
4026 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
4027 // requires that the walk visits a node's inputs before visiting the node.
4028 void Compile::final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Reshape_Counts &frc ) {
4029   ResourceArea *area = Thread::current()->resource_area();
4030   Unique_Node_List sfpt(area);
4031 
4032   frc._visited.set(root->_idx); // first, mark node as visited
4033   uint cnt = root->req();
4034   Node *n = root;
4035   uint  i = 0;
4036   while (true) {
4037     if (i < cnt) {
4038       // Place all non-visited non-null inputs onto stack
4039       Node* m = n->in(i);
4040       ++i;
4041       if (m != NULL && !frc._visited.test_set(m->_idx)) {
4042         if (m->is_SafePoint() && m->as_SafePoint()->jvms() != NULL) {
4043           // compute worst case interpreter size in case of a deoptimization
4044           update_interpreter_frame_size(m->as_SafePoint()->jvms()->interpreter_frame_size());
4045 
4046           sfpt.push(m);
4047         }
4048         cnt = m->req();
4049         nstack.push(n, i); // put on stack parent and next input's index
4050         n = m;
4051         i = 0;
4052       }
4053     } else {
4054       // Now do post-visit work
4055       final_graph_reshaping_impl( n, frc );
4056       if (nstack.is_empty())
4057         break;             // finished
4058       n = nstack.node();   // Get node from stack
4059       cnt = n->req();
4060       i = nstack.index();
4061       nstack.pop();        // Shift to the next node on stack
4062     }
4063   }
4064 
4065   // Skip next transformation if compressed oops are not used.
4066   if ((UseCompressedOops && !Matcher::gen_narrow_oop_implicit_null_checks()) ||
4067       (!UseCompressedOops && !UseCompressedClassPointers))
4068     return;
4069 
4070   // Go over safepoints nodes to skip DecodeN/DecodeNKlass nodes for debug edges.
4071   // It could be done for an uncommon traps or any safepoints/calls
4072   // if the DecodeN/DecodeNKlass node is referenced only in a debug info.
4073   while (sfpt.size() > 0) {
4074     n = sfpt.pop();
4075     JVMState *jvms = n->as_SafePoint()->jvms();
4076     assert(jvms != NULL, "sanity");
4077     int start = jvms->debug_start();
4078     int end   = n->req();
4079     bool is_uncommon = (n->is_CallStaticJava() &&
4080                         n->as_CallStaticJava()->uncommon_trap_request() != 0);
4081     for (int j = start; j < end; j++) {
4082       Node* in = n->in(j);
4083       if (in->is_DecodeNarrowPtr()) {
4084         bool safe_to_skip = true;
4085         if (!is_uncommon ) {
4086           // Is it safe to skip?
4087           for (uint i = 0; i < in->outcnt(); i++) {
4088             Node* u = in->raw_out(i);
4089             if (!u->is_SafePoint() ||
4090                 (u->is_Call() && u->as_Call()->has_non_debug_use(n))) {
4091               safe_to_skip = false;
4092             }
4093           }
4094         }
4095         if (safe_to_skip) {
4096           n->set_req(j, in->in(1));
4097         }
4098         if (in->outcnt() == 0) {
4099           in->disconnect_inputs(NULL, this);
4100         }
4101       }
4102     }
4103   }
4104 }
4105 
4106 //------------------------------final_graph_reshaping--------------------------
4107 // Final Graph Reshaping.
4108 //
4109 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
4110 //     and not commoned up and forced early.  Must come after regular
4111 //     optimizations to avoid GVN undoing the cloning.  Clone constant
4112 //     inputs to Loop Phis; these will be split by the allocator anyways.
4113 //     Remove Opaque nodes.
4114 // (2) Move last-uses by commutative operations to the left input to encourage
4115 //     Intel update-in-place two-address operations and better register usage
4116 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
4117 //     calls canonicalizing them back.
4118 // (3) Count the number of double-precision FP ops, single-precision FP ops
4119 //     and call sites.  On Intel, we can get correct rounding either by
4120 //     forcing singles to memory (requires extra stores and loads after each
4121 //     FP bytecode) or we can set a rounding mode bit (requires setting and
4122 //     clearing the mode bit around call sites).  The mode bit is only used
4123 //     if the relative frequency of single FP ops to calls is low enough.
4124 //     This is a key transform for SPEC mpeg_audio.
4125 // (4) Detect infinite loops; blobs of code reachable from above but not
4126 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
4127 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
4128 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
4129 //     Detection is by looking for IfNodes where only 1 projection is
4130 //     reachable from below or CatchNodes missing some targets.
4131 // (5) Assert for insane oop offsets in debug mode.
4132 
4133 bool Compile::final_graph_reshaping() {
4134   // an infinite loop may have been eliminated by the optimizer,
4135   // in which case the graph will be empty.
4136   if (root()->req() == 1) {
4137     record_method_not_compilable("trivial infinite loop");
4138     return true;
4139   }
4140 
4141   // Expensive nodes have their control input set to prevent the GVN
4142   // from freely commoning them. There's no GVN beyond this point so
4143   // no need to keep the control input. We want the expensive nodes to
4144   // be freely moved to the least frequent code path by gcm.
4145   assert(OptimizeExpensiveOps || expensive_count() == 0, "optimization off but list non empty?");
4146   for (int i = 0; i < expensive_count(); i++) {
4147     _expensive_nodes->at(i)->set_req(0, NULL);
4148   }
4149 
4150   Final_Reshape_Counts frc;
4151 
4152   // Visit everybody reachable!
4153   // Allocate stack of size C->live_nodes()/2 to avoid frequent realloc
4154   Node_Stack nstack(live_nodes() >> 1);
4155   final_graph_reshaping_walk(nstack, root(), frc);
4156 
4157   // Check for unreachable (from below) code (i.e., infinite loops).
4158   for( uint i = 0; i < frc._tests.size(); i++ ) {
4159     MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
4160     // Get number of CFG targets.
4161     // Note that PCTables include exception targets after calls.
4162     uint required_outcnt = n->required_outcnt();
4163     if (n->outcnt() != required_outcnt) {
4164       // Check for a few special cases.  Rethrow Nodes never take the
4165       // 'fall-thru' path, so expected kids is 1 less.
4166       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
4167         if (n->in(0)->in(0)->is_Call()) {
4168           CallNode *call = n->in(0)->in(0)->as_Call();
4169           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
4170             required_outcnt--;      // Rethrow always has 1 less kid
4171           } else if (call->req() > TypeFunc::Parms &&
4172                      call->is_CallDynamicJava()) {
4173             // Check for null receiver. In such case, the optimizer has
4174             // detected that the virtual call will always result in a null
4175             // pointer exception. The fall-through projection of this CatchNode
4176             // will not be populated.
4177             Node *arg0 = call->in(TypeFunc::Parms);
4178             if (arg0->is_Type() &&
4179                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
4180               required_outcnt--;
4181             }
4182           } else if (call->entry_point() == OptoRuntime::new_array_Java() &&
4183                      call->req() > TypeFunc::Parms+1 &&
4184                      call->is_CallStaticJava()) {
4185             // Check for negative array length. In such case, the optimizer has
4186             // detected that the allocation attempt will always result in an
4187             // exception. There is no fall-through projection of this CatchNode .
4188             Node *arg1 = call->in(TypeFunc::Parms+1);
4189             if (arg1->is_Type() &&
4190                 arg1->as_Type()->type()->join(TypeInt::POS)->empty()) {
4191               required_outcnt--;
4192             }
4193           }
4194         }
4195       }
4196       // Recheck with a better notion of 'required_outcnt'
4197       if (n->outcnt() != required_outcnt) {
4198         record_method_not_compilable("malformed control flow");
4199         return true;            // Not all targets reachable!
4200       }
4201     }
4202     // Check that I actually visited all kids.  Unreached kids
4203     // must be infinite loops.
4204     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
4205       if (!frc._visited.test(n->fast_out(j)->_idx)) {
4206         record_method_not_compilable("infinite loop");
4207         return true;            // Found unvisited kid; must be unreach
4208       }
4209 
4210     // Here so verification code in final_graph_reshaping_walk()
4211     // always see an OuterStripMinedLoopEnd
4212     if (n->is_OuterStripMinedLoopEnd()) {
4213       IfNode* init_iff = n->as_If();
4214       Node* iff = new IfNode(init_iff->in(0), init_iff->in(1), init_iff->_prob, init_iff->_fcnt);
4215       n->subsume_by(iff, this);
4216     }
4217   }
4218 
4219   // If original bytecodes contained a mixture of floats and doubles
4220   // check if the optimizer has made it homogenous, item (3).
4221   if( Use24BitFPMode && Use24BitFP && UseSSE == 0 &&
4222       frc.get_float_count() > 32 &&
4223       frc.get_double_count() == 0 &&
4224       (10 * frc.get_call_count() < frc.get_float_count()) ) {
4225     set_24_bit_selection_and_mode( false,  true );
4226   }
4227 
4228   set_java_calls(frc.get_java_call_count());
4229   set_inner_loops(frc.get_inner_loop_count());
4230 
4231   // No infinite loops, no reason to bail out.
4232   return false;
4233 }
4234 
4235 //-----------------------------too_many_traps----------------------------------
4236 // Report if there are too many traps at the current method and bci.
4237 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
4238 bool Compile::too_many_traps(ciMethod* method,
4239                              int bci,
4240                              Deoptimization::DeoptReason reason) {
4241   ciMethodData* md = method->method_data();
4242   if (md->is_empty()) {
4243     // Assume the trap has not occurred, or that it occurred only
4244     // because of a transient condition during start-up in the interpreter.
4245     return false;
4246   }
4247   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
4248   if (md->has_trap_at(bci, m, reason) != 0) {
4249     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
4250     // Also, if there are multiple reasons, or if there is no per-BCI record,
4251     // assume the worst.
4252     if (log())
4253       log()->elem("observe trap='%s' count='%d'",
4254                   Deoptimization::trap_reason_name(reason),
4255                   md->trap_count(reason));
4256     return true;
4257   } else {
4258     // Ignore method/bci and see if there have been too many globally.
4259     return too_many_traps(reason, md);
4260   }
4261 }
4262 
4263 // Less-accurate variant which does not require a method and bci.
4264 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
4265                              ciMethodData* logmd) {
4266   if (trap_count(reason) >= Deoptimization::per_method_trap_limit(reason)) {
4267     // Too many traps globally.
4268     // Note that we use cumulative trap_count, not just md->trap_count.
4269     if (log()) {
4270       int mcount = (logmd == NULL)? -1: (int)logmd->trap_count(reason);
4271       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
4272                   Deoptimization::trap_reason_name(reason),
4273                   mcount, trap_count(reason));
4274     }
4275     return true;
4276   } else {
4277     // The coast is clear.
4278     return false;
4279   }
4280 }
4281 
4282 //--------------------------too_many_recompiles--------------------------------
4283 // Report if there are too many recompiles at the current method and bci.
4284 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
4285 // Is not eager to return true, since this will cause the compiler to use
4286 // Action_none for a trap point, to avoid too many recompilations.
4287 bool Compile::too_many_recompiles(ciMethod* method,
4288                                   int bci,
4289                                   Deoptimization::DeoptReason reason) {
4290   ciMethodData* md = method->method_data();
4291   if (md->is_empty()) {
4292     // Assume the trap has not occurred, or that it occurred only
4293     // because of a transient condition during start-up in the interpreter.
4294     return false;
4295   }
4296   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
4297   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
4298   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
4299   Deoptimization::DeoptReason per_bc_reason
4300     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
4301   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
4302   if ((per_bc_reason == Deoptimization::Reason_none
4303        || md->has_trap_at(bci, m, reason) != 0)
4304       // The trap frequency measure we care about is the recompile count:
4305       && md->trap_recompiled_at(bci, m)
4306       && md->overflow_recompile_count() >= bc_cutoff) {
4307     // Do not emit a trap here if it has already caused recompilations.
4308     // Also, if there are multiple reasons, or if there is no per-BCI record,
4309     // assume the worst.
4310     if (log())
4311       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
4312                   Deoptimization::trap_reason_name(reason),
4313                   md->trap_count(reason),
4314                   md->overflow_recompile_count());
4315     return true;
4316   } else if (trap_count(reason) != 0
4317              && decompile_count() >= m_cutoff) {
4318     // Too many recompiles globally, and we have seen this sort of trap.
4319     // Use cumulative decompile_count, not just md->decompile_count.
4320     if (log())
4321       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
4322                   Deoptimization::trap_reason_name(reason),
4323                   md->trap_count(reason), trap_count(reason),
4324                   md->decompile_count(), decompile_count());
4325     return true;
4326   } else {
4327     // The coast is clear.
4328     return false;
4329   }
4330 }
4331 
4332 // Compute when not to trap. Used by matching trap based nodes and
4333 // NullCheck optimization.
4334 void Compile::set_allowed_deopt_reasons() {
4335   _allowed_reasons = 0;
4336   if (is_method_compilation()) {
4337     for (int rs = (int)Deoptimization::Reason_none+1; rs < Compile::trapHistLength; rs++) {
4338       assert(rs < BitsPerInt, "recode bit map");
4339       if (!too_many_traps((Deoptimization::DeoptReason) rs)) {
4340         _allowed_reasons |= nth_bit(rs);
4341       }
4342     }
4343   }
4344 }
4345 
4346 bool Compile::needs_clinit_barrier(ciMethod* method, ciMethod* accessing_method) {
4347   return method->is_static() && needs_clinit_barrier(method->holder(), accessing_method);
4348 }
4349 
4350 bool Compile::needs_clinit_barrier(ciField* field, ciMethod* accessing_method) {
4351   return field->is_static() && needs_clinit_barrier(field->holder(), accessing_method);
4352 }
4353 
4354 bool Compile::needs_clinit_barrier(ciInstanceKlass* holder, ciMethod* accessing_method) {
4355   if (holder->is_initialized()) {
4356     return false;
4357   }
4358   if (holder->is_being_initialized()) {
4359     if (accessing_method->holder() == holder) {
4360       // Access inside a class. The barrier can be elided when access happens in <clinit>,
4361       // <init>, or a static method. In all those cases, there was an initialization
4362       // barrier on the holder klass passed.
4363       if (accessing_method->is_class_initializer() ||
4364           accessing_method->is_object_constructor() ||
4365           accessing_method->is_static()) {
4366         return false;
4367       }
4368     } else if (accessing_method->holder()->is_subclass_of(holder)) {
4369       // Access from a subclass. The barrier can be elided only when access happens in <clinit>.
4370       // In case of <init> or a static method, the barrier is on the subclass is not enough:
4371       // child class can become fully initialized while its parent class is still being initialized.
4372       if (accessing_method->is_class_initializer()) {
4373         return false;
4374       }
4375     }
4376     ciMethod* root = method(); // the root method of compilation
4377     if (root != accessing_method) {
4378       return needs_clinit_barrier(holder, root); // check access in the context of compilation root
4379     }
4380   }
4381   return true;
4382 }
4383 
4384 #ifndef PRODUCT
4385 //------------------------------verify_graph_edges---------------------------
4386 // Walk the Graph and verify that there is a one-to-one correspondence
4387 // between Use-Def edges and Def-Use edges in the graph.
4388 void Compile::verify_graph_edges(bool no_dead_code) {
4389   if (VerifyGraphEdges) {
4390     ResourceArea *area = Thread::current()->resource_area();
4391     Unique_Node_List visited(area);
4392     // Call recursive graph walk to check edges
4393     _root->verify_edges(visited);
4394     if (no_dead_code) {
4395       // Now make sure that no visited node is used by an unvisited node.
4396       bool dead_nodes = false;
4397       Unique_Node_List checked(area);
4398       while (visited.size() > 0) {
4399         Node* n = visited.pop();
4400         checked.push(n);
4401         for (uint i = 0; i < n->outcnt(); i++) {
4402           Node* use = n->raw_out(i);
4403           if (checked.member(use))  continue;  // already checked
4404           if (visited.member(use))  continue;  // already in the graph
4405           if (use->is_Con())        continue;  // a dead ConNode is OK
4406           // At this point, we have found a dead node which is DU-reachable.
4407           if (!dead_nodes) {
4408             tty->print_cr("*** Dead nodes reachable via DU edges:");
4409             dead_nodes = true;
4410           }
4411           use->dump(2);
4412           tty->print_cr("---");
4413           checked.push(use);  // No repeats; pretend it is now checked.
4414         }
4415       }
4416       assert(!dead_nodes, "using nodes must be reachable from root");
4417     }
4418   }
4419 }
4420 #endif
4421 
4422 // The Compile object keeps track of failure reasons separately from the ciEnv.
4423 // This is required because there is not quite a 1-1 relation between the
4424 // ciEnv and its compilation task and the Compile object.  Note that one
4425 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
4426 // to backtrack and retry without subsuming loads.  Other than this backtracking
4427 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
4428 // by the logic in C2Compiler.
4429 void Compile::record_failure(const char* reason) {
4430   if (log() != NULL) {
4431     log()->elem("failure reason='%s' phase='compile'", reason);
4432   }
4433   if (_failure_reason == NULL) {
4434     // Record the first failure reason.
4435     _failure_reason = reason;
4436   }
4437 
4438   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
4439     C->print_method(PHASE_FAILURE);
4440   }
4441   _root = NULL;  // flush the graph, too
4442 }
4443 
4444 Compile::TracePhase::TracePhase(const char* name, elapsedTimer* accumulator)
4445   : TraceTime(name, accumulator, CITime, CITimeVerbose),
4446     _phase_name(name), _dolog(CITimeVerbose)
4447 {
4448   if (_dolog) {
4449     C = Compile::current();
4450     _log = C->log();
4451   } else {
4452     C = NULL;
4453     _log = NULL;
4454   }
4455   if (_log != NULL) {
4456     _log->begin_head("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
4457     _log->stamp();
4458     _log->end_head();
4459   }
4460 }
4461 
4462 Compile::TracePhase::~TracePhase() {
4463 
4464   C = Compile::current();
4465   if (_dolog) {
4466     _log = C->log();
4467   } else {
4468     _log = NULL;
4469   }
4470 
4471 #ifdef ASSERT
4472   if (PrintIdealNodeCount) {
4473     tty->print_cr("phase name='%s' nodes='%d' live='%d' live_graph_walk='%d'",
4474                   _phase_name, C->unique(), C->live_nodes(), C->count_live_nodes_by_graph_walk());
4475   }
4476 
4477   if (VerifyIdealNodeCount) {
4478     Compile::current()->print_missing_nodes();
4479   }
4480 #endif
4481 
4482   if (_log != NULL) {
4483     _log->done("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
4484   }
4485 }
4486 
4487 //=============================================================================
4488 // Two Constant's are equal when the type and the value are equal.
4489 bool Compile::Constant::operator==(const Constant& other) {
4490   if (type()          != other.type()         )  return false;
4491   if (can_be_reused() != other.can_be_reused())  return false;
4492   // For floating point values we compare the bit pattern.
4493   switch (type()) {
4494   case T_INT:
4495   case T_FLOAT:   return (_v._value.i == other._v._value.i);
4496   case T_LONG:
4497   case T_DOUBLE:  return (_v._value.j == other._v._value.j);
4498   case T_OBJECT:
4499   case T_ADDRESS: return (_v._value.l == other._v._value.l);
4500   case T_VOID:    return (_v._value.l == other._v._value.l);  // jump-table entries
4501   case T_METADATA: return (_v._metadata == other._v._metadata);
4502   default: ShouldNotReachHere(); return false;
4503   }
4504 }
4505 
4506 static int type_to_size_in_bytes(BasicType t) {
4507   switch (t) {
4508   case T_INT:     return sizeof(jint   );
4509   case T_LONG:    return sizeof(jlong  );
4510   case T_FLOAT:   return sizeof(jfloat );
4511   case T_DOUBLE:  return sizeof(jdouble);
4512   case T_METADATA: return sizeof(Metadata*);
4513     // We use T_VOID as marker for jump-table entries (labels) which
4514     // need an internal word relocation.
4515   case T_VOID:
4516   case T_ADDRESS:
4517   case T_OBJECT:  return sizeof(jobject);
4518   default:
4519     ShouldNotReachHere();
4520     return -1;
4521   }
4522 }
4523 
4524 int Compile::ConstantTable::qsort_comparator(Constant* a, Constant* b) {
4525   // sort descending
4526   if (a->freq() > b->freq())  return -1;
4527   if (a->freq() < b->freq())  return  1;
4528   return 0;
4529 }
4530 
4531 void Compile::ConstantTable::calculate_offsets_and_size() {
4532   // First, sort the array by frequencies.
4533   _constants.sort(qsort_comparator);
4534 
4535 #ifdef ASSERT
4536   // Make sure all jump-table entries were sorted to the end of the
4537   // array (they have a negative frequency).
4538   bool found_void = false;
4539   for (int i = 0; i < _constants.length(); i++) {
4540     Constant con = _constants.at(i);
4541     if (con.type() == T_VOID)
4542       found_void = true;  // jump-tables
4543     else
4544       assert(!found_void, "wrong sorting");
4545   }
4546 #endif
4547 
4548   int offset = 0;
4549   for (int i = 0; i < _constants.length(); i++) {
4550     Constant* con = _constants.adr_at(i);
4551 
4552     // Align offset for type.
4553     int typesize = type_to_size_in_bytes(con->type());
4554     offset = align_up(offset, typesize);
4555     con->set_offset(offset);   // set constant's offset
4556 
4557     if (con->type() == T_VOID) {
4558       MachConstantNode* n = (MachConstantNode*) con->get_jobject();
4559       offset = offset + typesize * n->outcnt();  // expand jump-table
4560     } else {
4561       offset = offset + typesize;
4562     }
4563   }
4564 
4565   // Align size up to the next section start (which is insts; see
4566   // CodeBuffer::align_at_start).
4567   assert(_size == -1, "already set?");
4568   _size = align_up(offset, (int)CodeEntryAlignment);
4569 }
4570 
4571 void Compile::ConstantTable::emit(CodeBuffer& cb) {
4572   MacroAssembler _masm(&cb);
4573   for (int i = 0; i < _constants.length(); i++) {
4574     Constant con = _constants.at(i);
4575     address constant_addr = NULL;
4576     switch (con.type()) {
4577     case T_INT:    constant_addr = _masm.int_constant(   con.get_jint()   ); break;
4578     case T_LONG:   constant_addr = _masm.long_constant(  con.get_jlong()  ); break;
4579     case T_FLOAT:  constant_addr = _masm.float_constant( con.get_jfloat() ); break;
4580     case T_DOUBLE: constant_addr = _masm.double_constant(con.get_jdouble()); break;
4581     case T_OBJECT: {
4582       jobject obj = con.get_jobject();
4583       int oop_index = _masm.oop_recorder()->find_index(obj);
4584       constant_addr = _masm.address_constant((address) obj, oop_Relocation::spec(oop_index));
4585       break;
4586     }
4587     case T_ADDRESS: {
4588       address addr = (address) con.get_jobject();
4589       constant_addr = _masm.address_constant(addr);
4590       break;
4591     }
4592     // We use T_VOID as marker for jump-table entries (labels) which
4593     // need an internal word relocation.
4594     case T_VOID: {
4595       MachConstantNode* n = (MachConstantNode*) con.get_jobject();
4596       // Fill the jump-table with a dummy word.  The real value is
4597       // filled in later in fill_jump_table.
4598       address dummy = (address) n;
4599       constant_addr = _masm.address_constant(dummy);
4600       // Expand jump-table
4601       for (uint i = 1; i < n->outcnt(); i++) {
4602         address temp_addr = _masm.address_constant(dummy + i);
4603         assert(temp_addr, "consts section too small");
4604       }
4605       break;
4606     }
4607     case T_METADATA: {
4608       Metadata* obj = con.get_metadata();
4609       int metadata_index = _masm.oop_recorder()->find_index(obj);
4610       constant_addr = _masm.address_constant((address) obj, metadata_Relocation::spec(metadata_index));
4611       break;
4612     }
4613     default: ShouldNotReachHere();
4614     }
4615     assert(constant_addr, "consts section too small");
4616     assert((constant_addr - _masm.code()->consts()->start()) == con.offset(),
4617             "must be: %d == %d", (int) (constant_addr - _masm.code()->consts()->start()), (int)(con.offset()));
4618   }
4619 }
4620 
4621 int Compile::ConstantTable::find_offset(Constant& con) const {
4622   int idx = _constants.find(con);
4623   guarantee(idx != -1, "constant must be in constant table");
4624   int offset = _constants.at(idx).offset();
4625   guarantee(offset != -1, "constant table not emitted yet?");
4626   return offset;
4627 }
4628 
4629 void Compile::ConstantTable::add(Constant& con) {
4630   if (con.can_be_reused()) {
4631     int idx = _constants.find(con);
4632     if (idx != -1 && _constants.at(idx).can_be_reused()) {
4633       _constants.adr_at(idx)->inc_freq(con.freq());  // increase the frequency by the current value
4634       return;
4635     }
4636   }
4637   (void) _constants.append(con);
4638 }
4639 
4640 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, BasicType type, jvalue value) {
4641   Block* b = Compile::current()->cfg()->get_block_for_node(n);
4642   Constant con(type, value, b->_freq);
4643   add(con);
4644   return con;
4645 }
4646 
4647 Compile::Constant Compile::ConstantTable::add(Metadata* metadata) {
4648   Constant con(metadata);
4649   add(con);
4650   return con;
4651 }
4652 
4653 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, MachOper* oper) {
4654   jvalue value;
4655   BasicType type = oper->type()->basic_type();
4656   switch (type) {
4657   case T_LONG:    value.j = oper->constantL(); break;
4658   case T_FLOAT:   value.f = oper->constantF(); break;
4659   case T_DOUBLE:  value.d = oper->constantD(); break;
4660   case T_OBJECT:
4661   case T_ADDRESS: value.l = (jobject) oper->constant(); break;
4662   case T_METADATA: return add((Metadata*)oper->constant()); break;
4663   default: guarantee(false, "unhandled type: %s", type2name(type));
4664   }
4665   return add(n, type, value);
4666 }
4667 
4668 Compile::Constant Compile::ConstantTable::add_jump_table(MachConstantNode* n) {
4669   jvalue value;
4670   // We can use the node pointer here to identify the right jump-table
4671   // as this method is called from Compile::Fill_buffer right before
4672   // the MachNodes are emitted and the jump-table is filled (means the
4673   // MachNode pointers do not change anymore).
4674   value.l = (jobject) n;
4675   Constant con(T_VOID, value, next_jump_table_freq(), false);  // Labels of a jump-table cannot be reused.
4676   add(con);
4677   return con;
4678 }
4679 
4680 void Compile::ConstantTable::fill_jump_table(CodeBuffer& cb, MachConstantNode* n, GrowableArray<Label*> labels) const {
4681   // If called from Compile::scratch_emit_size do nothing.
4682   if (Compile::current()->in_scratch_emit_size())  return;
4683 
4684   assert(labels.is_nonempty(), "must be");
4685   assert((uint) labels.length() == n->outcnt(), "must be equal: %d == %d", labels.length(), n->outcnt());
4686 
4687   // Since MachConstantNode::constant_offset() also contains
4688   // table_base_offset() we need to subtract the table_base_offset()
4689   // to get the plain offset into the constant table.
4690   int offset = n->constant_offset() - table_base_offset();
4691 
4692   MacroAssembler _masm(&cb);
4693   address* jump_table_base = (address*) (_masm.code()->consts()->start() + offset);
4694 
4695   for (uint i = 0; i < n->outcnt(); i++) {
4696     address* constant_addr = &jump_table_base[i];
4697     assert(*constant_addr == (((address) n) + i), "all jump-table entries must contain adjusted node pointer: " INTPTR_FORMAT " == " INTPTR_FORMAT, p2i(*constant_addr), p2i(((address) n) + i));
4698     *constant_addr = cb.consts()->target(*labels.at(i), (address) constant_addr);
4699     cb.consts()->relocate((address) constant_addr, relocInfo::internal_word_type);
4700   }
4701 }
4702 
4703 //----------------------------static_subtype_check-----------------------------
4704 // Shortcut important common cases when superklass is exact:
4705 // (0) superklass is java.lang.Object (can occur in reflective code)
4706 // (1) subklass is already limited to a subtype of superklass => always ok
4707 // (2) subklass does not overlap with superklass => always fail
4708 // (3) superklass has NO subtypes and we can check with a simple compare.
4709 int Compile::static_subtype_check(ciKlass* superk, ciKlass* subk) {
4710   if (StressReflectiveCode || superk == NULL || subk == NULL) {
4711     return SSC_full_test;       // Let caller generate the general case.
4712   }
4713 
4714   if (superk == env()->Object_klass()) {
4715     return SSC_always_true;     // (0) this test cannot fail
4716   }
4717 
4718   ciType* superelem = superk;
4719   if (superelem->is_array_klass()) {
4720     ciArrayKlass* ak = superelem->as_array_klass();
4721     superelem = superelem->as_array_klass()->base_element_type();
4722   }
4723 
4724   if (!subk->is_interface()) {  // cannot trust static interface types yet
4725     if (subk->is_subtype_of(superk)) {
4726       return SSC_always_true;   // (1) false path dead; no dynamic test needed
4727     }
4728     if (!(superelem->is_klass() && superelem->as_klass()->is_interface()) &&
4729         !superk->is_subtype_of(subk)) {
4730       return SSC_always_false;
4731     }
4732   }
4733 
4734   // Do not fold the subtype check to an array klass pointer comparison for [V? arrays.
4735   // [V is a subtype of [V? but the klass for [V is not equal to the klass for [V?. Perform a full test.
4736   if (superk->is_obj_array_klass() && !superk->as_array_klass()->storage_properties().is_null_free() && superk->as_array_klass()->element_klass()->is_valuetype()) {
4737     return SSC_full_test;
4738   }
4739   // If casting to an instance klass, it must have no subtypes
4740   if (superk->is_interface()) {
4741     // Cannot trust interfaces yet.
4742     // %%% S.B. superk->nof_implementors() == 1
4743   } else if (superelem->is_instance_klass()) {
4744     ciInstanceKlass* ik = superelem->as_instance_klass();
4745     if (!ik->has_subklass() && !ik->is_interface()) {
4746       if (!ik->is_final()) {
4747         // Add a dependency if there is a chance of a later subclass.
4748         dependencies()->assert_leaf_type(ik);
4749       }
4750       return SSC_easy_test;     // (3) caller can do a simple ptr comparison
4751     }
4752   } else {
4753     // A primitive array type has no subtypes.
4754     return SSC_easy_test;       // (3) caller can do a simple ptr comparison
4755   }
4756 
4757   return SSC_full_test;
4758 }
4759 
4760 Node* Compile::conv_I2X_index(PhaseGVN* phase, Node* idx, const TypeInt* sizetype, Node* ctrl) {
4761 #ifdef _LP64
4762   // The scaled index operand to AddP must be a clean 64-bit value.
4763   // Java allows a 32-bit int to be incremented to a negative
4764   // value, which appears in a 64-bit register as a large
4765   // positive number.  Using that large positive number as an
4766   // operand in pointer arithmetic has bad consequences.
4767   // On the other hand, 32-bit overflow is rare, and the possibility
4768   // can often be excluded, if we annotate the ConvI2L node with
4769   // a type assertion that its value is known to be a small positive
4770   // number.  (The prior range check has ensured this.)
4771   // This assertion is used by ConvI2LNode::Ideal.
4772   int index_max = max_jint - 1;  // array size is max_jint, index is one less
4773   if (sizetype != NULL) index_max = sizetype->_hi - 1;
4774   const TypeInt* iidxtype = TypeInt::make(0, index_max, Type::WidenMax);
4775   idx = constrained_convI2L(phase, idx, iidxtype, ctrl);
4776 #endif
4777   return idx;
4778 }
4779 
4780 // Convert integer value to a narrowed long type dependent on ctrl (for example, a range check)
4781 Node* Compile::constrained_convI2L(PhaseGVN* phase, Node* value, const TypeInt* itype, Node* ctrl) {
4782   if (ctrl != NULL) {
4783     // Express control dependency by a CastII node with a narrow type.
4784     value = new CastIINode(value, itype, false, true /* range check dependency */);
4785     // Make the CastII node dependent on the control input to prevent the narrowed ConvI2L
4786     // node from floating above the range check during loop optimizations. Otherwise, the
4787     // ConvI2L node may be eliminated independently of the range check, causing the data path
4788     // to become TOP while the control path is still there (although it's unreachable).
4789     value->set_req(0, ctrl);
4790     // Save CastII node to remove it after loop optimizations.
4791     phase->C->add_range_check_cast(value);
4792     value = phase->transform(value);
4793   }
4794   const TypeLong* ltype = TypeLong::make(itype->_lo, itype->_hi, itype->_widen);
4795   return phase->transform(new ConvI2LNode(value, ltype));
4796 }
4797 
4798 // The message about the current inlining is accumulated in
4799 // _print_inlining_stream and transfered into the _print_inlining_list
4800 // once we know whether inlining succeeds or not. For regular
4801 // inlining, messages are appended to the buffer pointed by
4802 // _print_inlining_idx in the _print_inlining_list. For late inlining,
4803 // a new buffer is added after _print_inlining_idx in the list. This
4804 // way we can update the inlining message for late inlining call site
4805 // when the inlining is attempted again.
4806 void Compile::print_inlining_init() {
4807   if (print_inlining() || print_intrinsics()) {
4808     _print_inlining_stream = new stringStream();
4809     _print_inlining_list = new (comp_arena())GrowableArray<PrintInliningBuffer>(comp_arena(), 1, 1, PrintInliningBuffer());
4810   }
4811 }
4812 
4813 void Compile::print_inlining_reinit() {
4814   if (print_inlining() || print_intrinsics()) {
4815     // Re allocate buffer when we change ResourceMark
4816     _print_inlining_stream = new stringStream();
4817   }
4818 }
4819 
4820 void Compile::print_inlining_reset() {
4821   _print_inlining_stream->reset();
4822 }
4823 
4824 void Compile::print_inlining_commit() {
4825   assert(print_inlining() || print_intrinsics(), "PrintInlining off?");
4826   // Transfer the message from _print_inlining_stream to the current
4827   // _print_inlining_list buffer and clear _print_inlining_stream.
4828   _print_inlining_list->at(_print_inlining_idx).ss()->write(_print_inlining_stream->as_string(), _print_inlining_stream->size());
4829   print_inlining_reset();
4830 }
4831 
4832 void Compile::print_inlining_push() {
4833   // Add new buffer to the _print_inlining_list at current position
4834   _print_inlining_idx++;
4835   _print_inlining_list->insert_before(_print_inlining_idx, PrintInliningBuffer());
4836 }
4837 
4838 Compile::PrintInliningBuffer& Compile::print_inlining_current() {
4839   return _print_inlining_list->at(_print_inlining_idx);
4840 }
4841 
4842 void Compile::print_inlining_update(CallGenerator* cg) {
4843   if (print_inlining() || print_intrinsics()) {
4844     if (!cg->is_late_inline()) {
4845       if (print_inlining_current().cg() != NULL) {
4846         print_inlining_push();
4847       }
4848       print_inlining_commit();
4849     } else {
4850       if (print_inlining_current().cg() != cg &&
4851           (print_inlining_current().cg() != NULL ||
4852            print_inlining_current().ss()->size() != 0)) {
4853         print_inlining_push();
4854       }
4855       print_inlining_commit();
4856       print_inlining_current().set_cg(cg);
4857     }
4858   }
4859 }
4860 
4861 void Compile::print_inlining_move_to(CallGenerator* cg) {
4862   // We resume inlining at a late inlining call site. Locate the
4863   // corresponding inlining buffer so that we can update it.
4864   if (print_inlining()) {
4865     for (int i = 0; i < _print_inlining_list->length(); i++) {
4866       if (_print_inlining_list->adr_at(i)->cg() == cg) {
4867         _print_inlining_idx = i;
4868         return;
4869       }
4870     }
4871     ShouldNotReachHere();
4872   }
4873 }
4874 
4875 void Compile::print_inlining_update_delayed(CallGenerator* cg) {
4876   if (print_inlining()) {
4877     assert(_print_inlining_stream->size() > 0, "missing inlining msg");
4878     assert(print_inlining_current().cg() == cg, "wrong entry");
4879     // replace message with new message
4880     _print_inlining_list->at_put(_print_inlining_idx, PrintInliningBuffer());
4881     print_inlining_commit();
4882     print_inlining_current().set_cg(cg);
4883   }
4884 }
4885 
4886 void Compile::print_inlining_assert_ready() {
4887   assert(!_print_inlining || _print_inlining_stream->size() == 0, "loosing data");
4888 }
4889 
4890 void Compile::process_print_inlining() {
4891   bool do_print_inlining = print_inlining() || print_intrinsics();
4892   if (do_print_inlining || log() != NULL) {
4893     // Print inlining message for candidates that we couldn't inline
4894     // for lack of space
4895     for (int i = 0; i < _late_inlines.length(); i++) {
4896       CallGenerator* cg = _late_inlines.at(i);
4897       if (!cg->is_mh_late_inline()) {
4898         const char* msg = "live nodes > LiveNodeCountInliningCutoff";
4899         if (do_print_inlining) {
4900           cg->print_inlining_late(msg);
4901         }
4902         log_late_inline_failure(cg, msg);
4903       }
4904     }
4905   }
4906   if (do_print_inlining) {
4907     ResourceMark rm;
4908     stringStream ss;
4909     for (int i = 0; i < _print_inlining_list->length(); i++) {
4910       ss.print("%s", _print_inlining_list->adr_at(i)->ss()->as_string());
4911     }
4912     size_t end = ss.size();
4913     _print_inlining_output = NEW_ARENA_ARRAY(comp_arena(), char, end+1);
4914     strncpy(_print_inlining_output, ss.base(), end+1);
4915     _print_inlining_output[end] = 0;
4916   }
4917 }
4918 
4919 void Compile::dump_print_inlining() {
4920   if (_print_inlining_output != NULL) {
4921     tty->print_raw(_print_inlining_output);
4922   }
4923 }
4924 
4925 void Compile::log_late_inline(CallGenerator* cg) {
4926   if (log() != NULL) {
4927     log()->head("late_inline method='%d'  inline_id='" JLONG_FORMAT "'", log()->identify(cg->method()),
4928                 cg->unique_id());
4929     JVMState* p = cg->call_node()->jvms();
4930     while (p != NULL) {
4931       log()->elem("jvms bci='%d' method='%d'", p->bci(), log()->identify(p->method()));
4932       p = p->caller();
4933     }
4934     log()->tail("late_inline");
4935   }
4936 }
4937 
4938 void Compile::log_late_inline_failure(CallGenerator* cg, const char* msg) {
4939   log_late_inline(cg);
4940   if (log() != NULL) {
4941     log()->inline_fail(msg);
4942   }
4943 }
4944 
4945 void Compile::log_inline_id(CallGenerator* cg) {
4946   if (log() != NULL) {
4947     // The LogCompilation tool needs a unique way to identify late
4948     // inline call sites. This id must be unique for this call site in
4949     // this compilation. Try to have it unique across compilations as
4950     // well because it can be convenient when grepping through the log
4951     // file.
4952     // Distinguish OSR compilations from others in case CICountOSR is
4953     // on.
4954     jlong id = ((jlong)unique()) + (((jlong)compile_id()) << 33) + (CICountOSR && is_osr_compilation() ? ((jlong)1) << 32 : 0);
4955     cg->set_unique_id(id);
4956     log()->elem("inline_id id='" JLONG_FORMAT "'", id);
4957   }
4958 }
4959 
4960 void Compile::log_inline_failure(const char* msg) {
4961   if (C->log() != NULL) {
4962     C->log()->inline_fail(msg);
4963   }
4964 }
4965 
4966 
4967 // Dump inlining replay data to the stream.
4968 // Don't change thread state and acquire any locks.
4969 void Compile::dump_inline_data(outputStream* out) {
4970   InlineTree* inl_tree = ilt();
4971   if (inl_tree != NULL) {
4972     out->print(" inline %d", inl_tree->count());
4973     inl_tree->dump_replay_data(out);
4974   }
4975 }
4976 
4977 int Compile::cmp_expensive_nodes(Node* n1, Node* n2) {
4978   if (n1->Opcode() < n2->Opcode())      return -1;
4979   else if (n1->Opcode() > n2->Opcode()) return 1;
4980 
4981   assert(n1->req() == n2->req(), "can't compare %s nodes: n1->req() = %d, n2->req() = %d", NodeClassNames[n1->Opcode()], n1->req(), n2->req());
4982   for (uint i = 1; i < n1->req(); i++) {
4983     if (n1->in(i) < n2->in(i))      return -1;
4984     else if (n1->in(i) > n2->in(i)) return 1;
4985   }
4986 
4987   return 0;
4988 }
4989 
4990 int Compile::cmp_expensive_nodes(Node** n1p, Node** n2p) {
4991   Node* n1 = *n1p;
4992   Node* n2 = *n2p;
4993 
4994   return cmp_expensive_nodes(n1, n2);
4995 }
4996 
4997 void Compile::sort_expensive_nodes() {
4998   if (!expensive_nodes_sorted()) {
4999     _expensive_nodes->sort(cmp_expensive_nodes);
5000   }
5001 }
5002 
5003 bool Compile::expensive_nodes_sorted() const {
5004   for (int i = 1; i < _expensive_nodes->length(); i++) {
5005     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i-1)) < 0) {
5006       return false;
5007     }
5008   }
5009   return true;
5010 }
5011 
5012 bool Compile::should_optimize_expensive_nodes(PhaseIterGVN &igvn) {
5013   if (_expensive_nodes->length() == 0) {
5014     return false;
5015   }
5016 
5017   assert(OptimizeExpensiveOps, "optimization off?");
5018 
5019   // Take this opportunity to remove dead nodes from the list
5020   int j = 0;
5021   for (int i = 0; i < _expensive_nodes->length(); i++) {
5022     Node* n = _expensive_nodes->at(i);
5023     if (!n->is_unreachable(igvn)) {
5024       assert(n->is_expensive(), "should be expensive");
5025       _expensive_nodes->at_put(j, n);
5026       j++;
5027     }
5028   }
5029   _expensive_nodes->trunc_to(j);
5030 
5031   // Then sort the list so that similar nodes are next to each other
5032   // and check for at least two nodes of identical kind with same data
5033   // inputs.
5034   sort_expensive_nodes();
5035 
5036   for (int i = 0; i < _expensive_nodes->length()-1; i++) {
5037     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i+1)) == 0) {
5038       return true;
5039     }
5040   }
5041 
5042   return false;
5043 }
5044 
5045 void Compile::cleanup_expensive_nodes(PhaseIterGVN &igvn) {
5046   if (_expensive_nodes->length() == 0) {
5047     return;
5048   }
5049 
5050   assert(OptimizeExpensiveOps, "optimization off?");
5051 
5052   // Sort to bring similar nodes next to each other and clear the
5053   // control input of nodes for which there's only a single copy.
5054   sort_expensive_nodes();
5055 
5056   int j = 0;
5057   int identical = 0;
5058   int i = 0;
5059   bool modified = false;
5060   for (; i < _expensive_nodes->length()-1; i++) {
5061     assert(j <= i, "can't write beyond current index");
5062     if (_expensive_nodes->at(i)->Opcode() == _expensive_nodes->at(i+1)->Opcode()) {
5063       identical++;
5064       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
5065       continue;
5066     }
5067     if (identical > 0) {
5068       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
5069       identical = 0;
5070     } else {
5071       Node* n = _expensive_nodes->at(i);
5072       igvn.replace_input_of(n, 0, NULL);
5073       igvn.hash_insert(n);
5074       modified = true;
5075     }
5076   }
5077   if (identical > 0) {
5078     _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
5079   } else if (_expensive_nodes->length() >= 1) {
5080     Node* n = _expensive_nodes->at(i);
5081     igvn.replace_input_of(n, 0, NULL);
5082     igvn.hash_insert(n);
5083     modified = true;
5084   }
5085   _expensive_nodes->trunc_to(j);
5086   if (modified) {
5087     igvn.optimize();
5088   }
5089 }
5090 
5091 void Compile::add_expensive_node(Node * n) {
5092   assert(!_expensive_nodes->contains(n), "duplicate entry in expensive list");
5093   assert(n->is_expensive(), "expensive nodes with non-null control here only");
5094   assert(!n->is_CFG() && !n->is_Mem(), "no cfg or memory nodes here");
5095   if (OptimizeExpensiveOps) {
5096     _expensive_nodes->append(n);
5097   } else {
5098     // Clear control input and let IGVN optimize expensive nodes if
5099     // OptimizeExpensiveOps is off.
5100     n->set_req(0, NULL);
5101   }
5102 }
5103 
5104 /**
5105  * Remove the speculative part of types and clean up the graph
5106  */
5107 void Compile::remove_speculative_types(PhaseIterGVN &igvn) {
5108   if (UseTypeSpeculation) {
5109     Unique_Node_List worklist;
5110     worklist.push(root());
5111     int modified = 0;
5112     // Go over all type nodes that carry a speculative type, drop the
5113     // speculative part of the type and enqueue the node for an igvn
5114     // which may optimize it out.
5115     for (uint next = 0; next < worklist.size(); ++next) {
5116       Node *n  = worklist.at(next);
5117       if (n->is_Type()) {
5118         TypeNode* tn = n->as_Type();
5119         const Type* t = tn->type();
5120         const Type* t_no_spec = t->remove_speculative();
5121         if (t_no_spec != t) {
5122           bool in_hash = igvn.hash_delete(n);
5123           assert(in_hash, "node should be in igvn hash table");
5124           tn->set_type(t_no_spec);
5125           igvn.hash_insert(n);
5126           igvn._worklist.push(n); // give it a chance to go away
5127           modified++;
5128         }
5129       }
5130       uint max = n->len();
5131       for( uint i = 0; i < max; ++i ) {
5132         Node *m = n->in(i);
5133         if (not_a_node(m))  continue;
5134         worklist.push(m);
5135       }
5136     }
5137     // Drop the speculative part of all types in the igvn's type table
5138     igvn.remove_speculative_types();
5139     if (modified > 0) {
5140       igvn.optimize();
5141     }
5142 #ifdef ASSERT
5143     // Verify that after the IGVN is over no speculative type has resurfaced
5144     worklist.clear();
5145     worklist.push(root());
5146     for (uint next = 0; next < worklist.size(); ++next) {
5147       Node *n  = worklist.at(next);
5148       const Type* t = igvn.type_or_null(n);
5149       assert((t == NULL) || (t == t->remove_speculative()), "no more speculative types");
5150       if (n->is_Type()) {
5151         t = n->as_Type()->type();
5152         assert(t == t->remove_speculative(), "no more speculative types");
5153       }
5154       uint max = n->len();
5155       for( uint i = 0; i < max; ++i ) {
5156         Node *m = n->in(i);
5157         if (not_a_node(m))  continue;
5158         worklist.push(m);
5159       }
5160     }
5161     igvn.check_no_speculative_types();
5162 #endif
5163   }
5164 }
5165 
5166 Node* Compile::optimize_acmp(PhaseGVN* phase, Node* a, Node* b) {
5167   const TypeInstPtr* ta = phase->type(a)->isa_instptr();
5168   const TypeInstPtr* tb = phase->type(b)->isa_instptr();
5169   if (!EnableValhalla || ta == NULL || tb == NULL ||
5170       ta->is_zero_type() || tb->is_zero_type() ||
5171       !ta->can_be_value_type() || !tb->can_be_value_type()) {
5172     // Use old acmp if one operand is null or not a value type
5173     return new CmpPNode(a, b);
5174   } else if (ta->is_valuetypeptr() || tb->is_valuetypeptr()) {
5175     // We know that one operand is a value type. Therefore,
5176     // new acmp will only return true if both operands are NULL.
5177     // Check if both operands are null by or'ing the oops.
5178     a = phase->transform(new CastP2XNode(NULL, a));
5179     b = phase->transform(new CastP2XNode(NULL, b));
5180     a = phase->transform(new OrXNode(a, b));
5181     return new CmpXNode(a, phase->MakeConX(0));
5182   }
5183   // Use new acmp
5184   return NULL;
5185 }
5186 
5187 // Auxiliary method to support randomized stressing/fuzzing.
5188 //
5189 // This method can be called the arbitrary number of times, with current count
5190 // as the argument. The logic allows selecting a single candidate from the
5191 // running list of candidates as follows:
5192 //    int count = 0;
5193 //    Cand* selected = null;
5194 //    while(cand = cand->next()) {
5195 //      if (randomized_select(++count)) {
5196 //        selected = cand;
5197 //      }
5198 //    }
5199 //
5200 // Including count equalizes the chances any candidate is "selected".
5201 // This is useful when we don't have the complete list of candidates to choose
5202 // from uniformly. In this case, we need to adjust the randomicity of the
5203 // selection, or else we will end up biasing the selection towards the latter
5204 // candidates.
5205 //
5206 // Quick back-envelope calculation shows that for the list of n candidates
5207 // the equal probability for the candidate to persist as "best" can be
5208 // achieved by replacing it with "next" k-th candidate with the probability
5209 // of 1/k. It can be easily shown that by the end of the run, the
5210 // probability for any candidate is converged to 1/n, thus giving the
5211 // uniform distribution among all the candidates.
5212 //
5213 // We don't care about the domain size as long as (RANDOMIZED_DOMAIN / count) is large.
5214 #define RANDOMIZED_DOMAIN_POW 29
5215 #define RANDOMIZED_DOMAIN (1 << RANDOMIZED_DOMAIN_POW)
5216 #define RANDOMIZED_DOMAIN_MASK ((1 << (RANDOMIZED_DOMAIN_POW + 1)) - 1)
5217 bool Compile::randomized_select(int count) {
5218   assert(count > 0, "only positive");
5219   return (os::random() & RANDOMIZED_DOMAIN_MASK) < (RANDOMIZED_DOMAIN / count);
5220 }
5221 
5222 CloneMap&     Compile::clone_map()                 { return _clone_map; }
5223 void          Compile::set_clone_map(Dict* d)      { _clone_map._dict = d; }
5224 
5225 void NodeCloneInfo::dump() const {
5226   tty->print(" {%d:%d} ", idx(), gen());
5227 }
5228 
5229 void CloneMap::clone(Node* old, Node* nnn, int gen) {
5230   uint64_t val = value(old->_idx);
5231   NodeCloneInfo cio(val);
5232   assert(val != 0, "old node should be in the map");
5233   NodeCloneInfo cin(cio.idx(), gen + cio.gen());
5234   insert(nnn->_idx, cin.get());
5235 #ifndef PRODUCT
5236   if (is_debug()) {
5237     tty->print_cr("CloneMap::clone inserted node %d info {%d:%d} into CloneMap", nnn->_idx, cin.idx(), cin.gen());
5238   }
5239 #endif
5240 }
5241 
5242 void CloneMap::verify_insert_and_clone(Node* old, Node* nnn, int gen) {
5243   NodeCloneInfo cio(value(old->_idx));
5244   if (cio.get() == 0) {
5245     cio.set(old->_idx, 0);
5246     insert(old->_idx, cio.get());
5247 #ifndef PRODUCT
5248     if (is_debug()) {
5249       tty->print_cr("CloneMap::verify_insert_and_clone inserted node %d info {%d:%d} into CloneMap", old->_idx, cio.idx(), cio.gen());
5250     }
5251 #endif
5252   }
5253   clone(old, nnn, gen);
5254 }
5255 
5256 int CloneMap::max_gen() const {
5257   int g = 0;
5258   DictI di(_dict);
5259   for(; di.test(); ++di) {
5260     int t = gen(di._key);
5261     if (g < t) {
5262       g = t;
5263 #ifndef PRODUCT
5264       if (is_debug()) {
5265         tty->print_cr("CloneMap::max_gen() update max=%d from %d", g, _2_node_idx_t(di._key));
5266       }
5267 #endif
5268     }
5269   }
5270   return g;
5271 }
5272 
5273 void CloneMap::dump(node_idx_t key) const {
5274   uint64_t val = value(key);
5275   if (val != 0) {
5276     NodeCloneInfo ni(val);
5277     ni.dump();
5278   }
5279 }