1 /*
   2  * Copyright (c) 1997, 2018, 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 "memory/resourceArea.hpp"
  37 #include "opto/addnode.hpp"
  38 #include "opto/block.hpp"
  39 #include "opto/c2compiler.hpp"
  40 #include "opto/callGenerator.hpp"
  41 #include "opto/callnode.hpp"
  42 #include "opto/castnode.hpp"
  43 #include "opto/cfgnode.hpp"
  44 #include "opto/chaitin.hpp"
  45 #include "opto/compile.hpp"
  46 #include "opto/connode.hpp"
  47 #include "opto/convertnode.hpp"
  48 #include "opto/divnode.hpp"
  49 #include "opto/escape.hpp"
  50 #include "opto/idealGraphPrinter.hpp"
  51 #include "opto/loopnode.hpp"
  52 #include "opto/machnode.hpp"
  53 #include "opto/macro.hpp"
  54 #include "opto/matcher.hpp"
  55 #include "opto/mathexactnode.hpp"
  56 #include "opto/memnode.hpp"
  57 #include "opto/mulnode.hpp"
  58 #include "opto/narrowptrnode.hpp"
  59 #include "opto/node.hpp"
  60 #include "opto/opcodes.hpp"
  61 #include "opto/output.hpp"
  62 #include "opto/parse.hpp"
  63 #include "opto/phaseX.hpp"
  64 #include "opto/rootnode.hpp"
  65 #include "opto/runtime.hpp"
  66 #include "opto/stringopts.hpp"
  67 #include "opto/type.hpp"
  68 #include "opto/vectornode.hpp"
  69 #include "runtime/arguments.hpp"
  70 #include "runtime/sharedRuntime.hpp"
  71 #include "runtime/signature.hpp"
  72 #include "runtime/stubRoutines.hpp"
  73 #include "runtime/timer.hpp"
  74 #include "utilities/align.hpp"
  75 #include "utilities/copy.hpp"
  76 #if INCLUDE_ALL_GCS
  77 #include "gc/g1/g1ThreadLocalData.hpp"
  78 #endif // INCLUDE_ALL_GCS
  79 
  80 
  81 // -------------------- Compile::mach_constant_base_node -----------------------
  82 // Constant table base node singleton.
  83 MachConstantBaseNode* Compile::mach_constant_base_node() {
  84   if (_mach_constant_base_node == NULL) {
  85     _mach_constant_base_node = new MachConstantBaseNode();
  86     _mach_constant_base_node->add_req(C->root());
  87   }
  88   return _mach_constant_base_node;
  89 }
  90 
  91 
  92 /// Support for intrinsics.
  93 
  94 // Return the index at which m must be inserted (or already exists).
  95 // The sort order is by the address of the ciMethod, with is_virtual as minor key.
  96 class IntrinsicDescPair {
  97  private:
  98   ciMethod* _m;
  99   bool _is_virtual;
 100  public:
 101   IntrinsicDescPair(ciMethod* m, bool is_virtual) : _m(m), _is_virtual(is_virtual) {}
 102   static int compare(IntrinsicDescPair* const& key, CallGenerator* const& elt) {
 103     ciMethod* m= elt->method();
 104     ciMethod* key_m = key->_m;
 105     if (key_m < m)      return -1;
 106     else if (key_m > m) return 1;
 107     else {
 108       bool is_virtual = elt->is_virtual();
 109       bool key_virtual = key->_is_virtual;
 110       if (key_virtual < is_virtual)      return -1;
 111       else if (key_virtual > is_virtual) return 1;
 112       else                               return 0;
 113     }
 114   }
 115 };
 116 int Compile::intrinsic_insertion_index(ciMethod* m, bool is_virtual, bool& found) {
 117 #ifdef ASSERT
 118   for (int i = 1; i < _intrinsics->length(); i++) {
 119     CallGenerator* cg1 = _intrinsics->at(i-1);
 120     CallGenerator* cg2 = _intrinsics->at(i);
 121     assert(cg1->method() != cg2->method()
 122            ? cg1->method()     < cg2->method()
 123            : cg1->is_virtual() < cg2->is_virtual(),
 124            "compiler intrinsics list must stay sorted");
 125   }
 126 #endif
 127   IntrinsicDescPair pair(m, is_virtual);
 128   return _intrinsics->find_sorted<IntrinsicDescPair*, IntrinsicDescPair::compare>(&pair, found);
 129 }
 130 
 131 void Compile::register_intrinsic(CallGenerator* cg) {
 132   if (_intrinsics == NULL) {
 133     _intrinsics = new (comp_arena())GrowableArray<CallGenerator*>(comp_arena(), 60, 0, NULL);
 134   }
 135   int len = _intrinsics->length();
 136   bool found = false;
 137   int index = intrinsic_insertion_index(cg->method(), cg->is_virtual(), found);
 138   assert(!found, "registering twice");
 139   _intrinsics->insert_before(index, cg);
 140   assert(find_intrinsic(cg->method(), cg->is_virtual()) == cg, "registration worked");
 141 }
 142 
 143 CallGenerator* Compile::find_intrinsic(ciMethod* m, bool is_virtual) {
 144   assert(m->is_loaded(), "don't try this on unloaded methods");
 145   if (_intrinsics != NULL) {
 146     bool found = false;
 147     int index = intrinsic_insertion_index(m, is_virtual, found);
 148      if (found) {
 149       return _intrinsics->at(index);
 150     }
 151   }
 152   // Lazily create intrinsics for intrinsic IDs well-known in the runtime.
 153   if (m->intrinsic_id() != vmIntrinsics::_none &&
 154       m->intrinsic_id() <= vmIntrinsics::LAST_COMPILER_INLINE) {
 155     CallGenerator* cg = make_vm_intrinsic(m, is_virtual);
 156     if (cg != NULL) {
 157       // Save it for next time:
 158       register_intrinsic(cg);
 159       return cg;
 160     } else {
 161       gather_intrinsic_statistics(m->intrinsic_id(), is_virtual, _intrinsic_disabled);
 162     }
 163   }
 164   return NULL;
 165 }
 166 
 167 // Compile:: register_library_intrinsics and make_vm_intrinsic are defined
 168 // in library_call.cpp.
 169 
 170 
 171 #ifndef PRODUCT
 172 // statistics gathering...
 173 
 174 juint  Compile::_intrinsic_hist_count[vmIntrinsics::ID_LIMIT] = {0};
 175 jubyte Compile::_intrinsic_hist_flags[vmIntrinsics::ID_LIMIT] = {0};
 176 
 177 bool Compile::gather_intrinsic_statistics(vmIntrinsics::ID id, bool is_virtual, int flags) {
 178   assert(id > vmIntrinsics::_none && id < vmIntrinsics::ID_LIMIT, "oob");
 179   int oflags = _intrinsic_hist_flags[id];
 180   assert(flags != 0, "what happened?");
 181   if (is_virtual) {
 182     flags |= _intrinsic_virtual;
 183   }
 184   bool changed = (flags != oflags);
 185   if ((flags & _intrinsic_worked) != 0) {
 186     juint count = (_intrinsic_hist_count[id] += 1);
 187     if (count == 1) {
 188       changed = true;           // first time
 189     }
 190     // increment the overall count also:
 191     _intrinsic_hist_count[vmIntrinsics::_none] += 1;
 192   }
 193   if (changed) {
 194     if (((oflags ^ flags) & _intrinsic_virtual) != 0) {
 195       // Something changed about the intrinsic's virtuality.
 196       if ((flags & _intrinsic_virtual) != 0) {
 197         // This is the first use of this intrinsic as a virtual call.
 198         if (oflags != 0) {
 199           // We already saw it as a non-virtual, so note both cases.
 200           flags |= _intrinsic_both;
 201         }
 202       } else if ((oflags & _intrinsic_both) == 0) {
 203         // This is the first use of this intrinsic as a non-virtual
 204         flags |= _intrinsic_both;
 205       }
 206     }
 207     _intrinsic_hist_flags[id] = (jubyte) (oflags | flags);
 208   }
 209   // update the overall flags also:
 210   _intrinsic_hist_flags[vmIntrinsics::_none] |= (jubyte) flags;
 211   return changed;
 212 }
 213 
 214 static char* format_flags(int flags, char* buf) {
 215   buf[0] = 0;
 216   if ((flags & Compile::_intrinsic_worked) != 0)    strcat(buf, ",worked");
 217   if ((flags & Compile::_intrinsic_failed) != 0)    strcat(buf, ",failed");
 218   if ((flags & Compile::_intrinsic_disabled) != 0)  strcat(buf, ",disabled");
 219   if ((flags & Compile::_intrinsic_virtual) != 0)   strcat(buf, ",virtual");
 220   if ((flags & Compile::_intrinsic_both) != 0)      strcat(buf, ",nonvirtual");
 221   if (buf[0] == 0)  strcat(buf, ",");
 222   assert(buf[0] == ',', "must be");
 223   return &buf[1];
 224 }
 225 
 226 void Compile::print_intrinsic_statistics() {
 227   char flagsbuf[100];
 228   ttyLocker ttyl;
 229   if (xtty != NULL)  xtty->head("statistics type='intrinsic'");
 230   tty->print_cr("Compiler intrinsic usage:");
 231   juint total = _intrinsic_hist_count[vmIntrinsics::_none];
 232   if (total == 0)  total = 1;  // avoid div0 in case of no successes
 233   #define PRINT_STAT_LINE(name, c, f) \
 234     tty->print_cr("  %4d (%4.1f%%) %s (%s)", (int)(c), ((c) * 100.0) / total, name, f);
 235   for (int index = 1 + (int)vmIntrinsics::_none; index < (int)vmIntrinsics::ID_LIMIT; index++) {
 236     vmIntrinsics::ID id = (vmIntrinsics::ID) index;
 237     int   flags = _intrinsic_hist_flags[id];
 238     juint count = _intrinsic_hist_count[id];
 239     if ((flags | count) != 0) {
 240       PRINT_STAT_LINE(vmIntrinsics::name_at(id), count, format_flags(flags, flagsbuf));
 241     }
 242   }
 243   PRINT_STAT_LINE("total", total, format_flags(_intrinsic_hist_flags[vmIntrinsics::_none], flagsbuf));
 244   if (xtty != NULL)  xtty->tail("statistics");
 245 }
 246 
 247 void Compile::print_statistics() {
 248   { ttyLocker ttyl;
 249     if (xtty != NULL)  xtty->head("statistics type='opto'");
 250     Parse::print_statistics();
 251     PhaseCCP::print_statistics();
 252     PhaseRegAlloc::print_statistics();
 253     Scheduling::print_statistics();
 254     PhasePeephole::print_statistics();
 255     PhaseIdealLoop::print_statistics();
 256     if (xtty != NULL)  xtty->tail("statistics");
 257   }
 258   if (_intrinsic_hist_flags[vmIntrinsics::_none] != 0) {
 259     // put this under its own <statistics> element.
 260     print_intrinsic_statistics();
 261   }
 262 }
 263 #endif //PRODUCT
 264 
 265 // Support for bundling info
 266 Bundle* Compile::node_bundling(const Node *n) {
 267   assert(valid_bundle_info(n), "oob");
 268   return &_node_bundling_base[n->_idx];
 269 }
 270 
 271 bool Compile::valid_bundle_info(const Node *n) {
 272   return (_node_bundling_limit > n->_idx);
 273 }
 274 
 275 
 276 void Compile::gvn_replace_by(Node* n, Node* nn) {
 277   for (DUIterator_Last imin, i = n->last_outs(imin); i >= imin; ) {
 278     Node* use = n->last_out(i);
 279     bool is_in_table = initial_gvn()->hash_delete(use);
 280     uint uses_found = 0;
 281     for (uint j = 0; j < use->len(); j++) {
 282       if (use->in(j) == n) {
 283         if (j < use->req())
 284           use->set_req(j, nn);
 285         else
 286           use->set_prec(j, nn);
 287         uses_found++;
 288       }
 289     }
 290     if (is_in_table) {
 291       // reinsert into table
 292       initial_gvn()->hash_find_insert(use);
 293     }
 294     record_for_igvn(use);
 295     i -= uses_found;    // we deleted 1 or more copies of this edge
 296   }
 297 }
 298 
 299 
 300 static inline bool not_a_node(const Node* n) {
 301   if (n == NULL)                   return true;
 302   if (((intptr_t)n & 1) != 0)      return true;  // uninitialized, etc.
 303   if (*(address*)n == badAddress)  return true;  // kill by Node::destruct
 304   return false;
 305 }
 306 
 307 // Identify all nodes that are reachable from below, useful.
 308 // Use breadth-first pass that records state in a Unique_Node_List,
 309 // recursive traversal is slower.
 310 void Compile::identify_useful_nodes(Unique_Node_List &useful) {
 311   int estimated_worklist_size = live_nodes();
 312   useful.map( estimated_worklist_size, NULL );  // preallocate space
 313 
 314   // Initialize worklist
 315   if (root() != NULL)     { useful.push(root()); }
 316   // If 'top' is cached, declare it useful to preserve cached node
 317   if( cached_top_node() ) { useful.push(cached_top_node()); }
 318 
 319   // Push all useful nodes onto the list, breadthfirst
 320   for( uint next = 0; next < useful.size(); ++next ) {
 321     assert( next < unique(), "Unique useful nodes < total nodes");
 322     Node *n  = useful.at(next);
 323     uint max = n->len();
 324     for( uint i = 0; i < max; ++i ) {
 325       Node *m = n->in(i);
 326       if (not_a_node(m))  continue;
 327       useful.push(m);
 328     }
 329   }
 330 }
 331 
 332 // Update dead_node_list with any missing dead nodes using useful
 333 // list. Consider all non-useful nodes to be useless i.e., dead nodes.
 334 void Compile::update_dead_node_list(Unique_Node_List &useful) {
 335   uint max_idx = unique();
 336   VectorSet& useful_node_set = useful.member_set();
 337 
 338   for (uint node_idx = 0; node_idx < max_idx; node_idx++) {
 339     // If node with index node_idx is not in useful set,
 340     // mark it as dead in dead node list.
 341     if (! useful_node_set.test(node_idx) ) {
 342       record_dead_node(node_idx);
 343     }
 344   }
 345 }
 346 
 347 void Compile::remove_useless_late_inlines(GrowableArray<CallGenerator*>* inlines, Unique_Node_List &useful) {
 348   int shift = 0;
 349   for (int i = 0; i < inlines->length(); i++) {
 350     CallGenerator* cg = inlines->at(i);
 351     CallNode* call = cg->call_node();
 352     if (shift > 0) {
 353       inlines->at_put(i-shift, cg);
 354     }
 355     if (!useful.member(call)) {
 356       shift++;
 357     }
 358   }
 359   inlines->trunc_to(inlines->length()-shift);
 360 }
 361 
 362 // Disconnect all useless nodes by disconnecting those at the boundary.
 363 void Compile::remove_useless_nodes(Unique_Node_List &useful) {
 364   uint next = 0;
 365   while (next < useful.size()) {
 366     Node *n = useful.at(next++);
 367     if (n->is_SafePoint()) {
 368       // We're done with a parsing phase. Replaced nodes are not valid
 369       // beyond that point.
 370       n->as_SafePoint()->delete_replaced_nodes();
 371     }
 372     // Use raw traversal of out edges since this code removes out edges
 373     int max = n->outcnt();
 374     for (int j = 0; j < max; ++j) {
 375       Node* child = n->raw_out(j);
 376       if (! useful.member(child)) {
 377         assert(!child->is_top() || child != top(),
 378                "If top is cached in Compile object it is in useful list");
 379         // Only need to remove this out-edge to the useless node
 380         n->raw_del_out(j);
 381         --j;
 382         --max;
 383       }
 384     }
 385     if (n->outcnt() == 1 && n->has_special_unique_user()) {
 386       record_for_igvn(n->unique_out());
 387     }
 388   }
 389   // Remove useless macro and predicate opaq nodes
 390   for (int i = C->macro_count()-1; i >= 0; i--) {
 391     Node* n = C->macro_node(i);
 392     if (!useful.member(n)) {
 393       remove_macro_node(n);
 394     }
 395   }
 396   // Remove useless CastII nodes with range check dependency
 397   for (int i = range_check_cast_count() - 1; i >= 0; i--) {
 398     Node* cast = range_check_cast_node(i);
 399     if (!useful.member(cast)) {
 400       remove_range_check_cast(cast);
 401     }
 402   }
 403   // Remove useless expensive nodes
 404   for (int i = C->expensive_count()-1; i >= 0; i--) {
 405     Node* n = C->expensive_node(i);
 406     if (!useful.member(n)) {
 407       remove_expensive_node(n);
 408     }
 409   }
 410   // Remove useless Opaque4 nodes
 411   for (int i = opaque4_count() - 1; i >= 0; i--) {
 412     Node* opaq = opaque4_node(i);
 413     if (!useful.member(opaq)) {
 414       remove_opaque4_node(opaq);
 415     }
 416   }
 417   // clean up the late inline lists
 418   remove_useless_late_inlines(&_string_late_inlines, useful);
 419   remove_useless_late_inlines(&_boxing_late_inlines, useful);
 420   remove_useless_late_inlines(&_late_inlines, useful);
 421   debug_only(verify_graph_edges(true/*check for no_dead_code*/);)
 422 }
 423 
 424 //------------------------------frame_size_in_words-----------------------------
 425 // frame_slots in units of words
 426 int Compile::frame_size_in_words() const {
 427   // shift is 0 in LP32 and 1 in LP64
 428   const int shift = (LogBytesPerWord - LogBytesPerInt);
 429   int words = _frame_slots >> shift;
 430   assert( words << shift == _frame_slots, "frame size must be properly aligned in LP64" );
 431   return words;
 432 }
 433 
 434 // To bang the stack of this compiled method we use the stack size
 435 // that the interpreter would need in case of a deoptimization. This
 436 // removes the need to bang the stack in the deoptimization blob which
 437 // in turn simplifies stack overflow handling.
 438 int Compile::bang_size_in_bytes() const {
 439   return MAX2(frame_size_in_bytes() + os::extra_bang_size_in_bytes(), _interpreter_frame_size);
 440 }
 441 
 442 // ============================================================================
 443 //------------------------------CompileWrapper---------------------------------
 444 class CompileWrapper : public StackObj {
 445   Compile *const _compile;
 446  public:
 447   CompileWrapper(Compile* compile);
 448 
 449   ~CompileWrapper();
 450 };
 451 
 452 CompileWrapper::CompileWrapper(Compile* compile) : _compile(compile) {
 453   // the Compile* pointer is stored in the current ciEnv:
 454   ciEnv* env = compile->env();
 455   assert(env == ciEnv::current(), "must already be a ciEnv active");
 456   assert(env->compiler_data() == NULL, "compile already active?");
 457   env->set_compiler_data(compile);
 458   assert(compile == Compile::current(), "sanity");
 459 
 460   compile->set_type_dict(NULL);
 461   compile->set_clone_map(new Dict(cmpkey, hashkey, _compile->comp_arena()));
 462   compile->clone_map().set_clone_idx(0);
 463   compile->set_type_hwm(NULL);
 464   compile->set_type_last_size(0);
 465   compile->set_last_tf(NULL, NULL);
 466   compile->set_indexSet_arena(NULL);
 467   compile->set_indexSet_free_block_list(NULL);
 468   compile->init_type_arena();
 469   Type::Initialize(compile);
 470   _compile->set_scratch_buffer_blob(NULL);
 471   _compile->begin_method();
 472   _compile->clone_map().set_debug(_compile->has_method() && _compile->directive()->CloneMapDebugOption);
 473 }
 474 CompileWrapper::~CompileWrapper() {
 475   _compile->end_method();
 476   if (_compile->scratch_buffer_blob() != NULL)
 477     BufferBlob::free(_compile->scratch_buffer_blob());
 478   _compile->env()->set_compiler_data(NULL);
 479 }
 480 
 481 
 482 //----------------------------print_compile_messages---------------------------
 483 void Compile::print_compile_messages() {
 484 #ifndef PRODUCT
 485   // Check if recompiling
 486   if (_subsume_loads == false && PrintOpto) {
 487     // Recompiling without allowing machine instructions to subsume loads
 488     tty->print_cr("*********************************************************");
 489     tty->print_cr("** Bailout: Recompile without subsuming loads          **");
 490     tty->print_cr("*********************************************************");
 491   }
 492   if (_do_escape_analysis != DoEscapeAnalysis && PrintOpto) {
 493     // Recompiling without escape analysis
 494     tty->print_cr("*********************************************************");
 495     tty->print_cr("** Bailout: Recompile without escape analysis          **");
 496     tty->print_cr("*********************************************************");
 497   }
 498   if (_eliminate_boxing != EliminateAutoBox && PrintOpto) {
 499     // Recompiling without boxing elimination
 500     tty->print_cr("*********************************************************");
 501     tty->print_cr("** Bailout: Recompile without boxing elimination       **");
 502     tty->print_cr("*********************************************************");
 503   }
 504   if (C->directive()->BreakAtCompileOption) {
 505     // Open the debugger when compiling this method.
 506     tty->print("### Breaking when compiling: ");
 507     method()->print_short_name();
 508     tty->cr();
 509     BREAKPOINT;
 510   }
 511 
 512   if( PrintOpto ) {
 513     if (is_osr_compilation()) {
 514       tty->print("[OSR]%3d", _compile_id);
 515     } else {
 516       tty->print("%3d", _compile_id);
 517     }
 518   }
 519 #endif
 520 }
 521 
 522 
 523 //-----------------------init_scratch_buffer_blob------------------------------
 524 // Construct a temporary BufferBlob and cache it for this compile.
 525 void Compile::init_scratch_buffer_blob(int const_size) {
 526   // If there is already a scratch buffer blob allocated and the
 527   // constant section is big enough, use it.  Otherwise free the
 528   // current and allocate a new one.
 529   BufferBlob* blob = scratch_buffer_blob();
 530   if ((blob != NULL) && (const_size <= _scratch_const_size)) {
 531     // Use the current blob.
 532   } else {
 533     if (blob != NULL) {
 534       BufferBlob::free(blob);
 535     }
 536 
 537     ResourceMark rm;
 538     _scratch_const_size = const_size;
 539     int size = (MAX_inst_size + MAX_stubs_size + _scratch_const_size);
 540     blob = BufferBlob::create("Compile::scratch_buffer", size);
 541     // Record the buffer blob for next time.
 542     set_scratch_buffer_blob(blob);
 543     // Have we run out of code space?
 544     if (scratch_buffer_blob() == NULL) {
 545       // Let CompilerBroker disable further compilations.
 546       record_failure("Not enough space for scratch buffer in CodeCache");
 547       return;
 548     }
 549   }
 550 
 551   // Initialize the relocation buffers
 552   relocInfo* locs_buf = (relocInfo*) blob->content_end() - MAX_locs_size;
 553   set_scratch_locs_memory(locs_buf);
 554 }
 555 
 556 
 557 //-----------------------scratch_emit_size-------------------------------------
 558 // Helper function that computes size by emitting code
 559 uint Compile::scratch_emit_size(const Node* n) {
 560   // Start scratch_emit_size section.
 561   set_in_scratch_emit_size(true);
 562 
 563   // Emit into a trash buffer and count bytes emitted.
 564   // This is a pretty expensive way to compute a size,
 565   // but it works well enough if seldom used.
 566   // All common fixed-size instructions are given a size
 567   // method by the AD file.
 568   // Note that the scratch buffer blob and locs memory are
 569   // allocated at the beginning of the compile task, and
 570   // may be shared by several calls to scratch_emit_size.
 571   // The allocation of the scratch buffer blob is particularly
 572   // expensive, since it has to grab the code cache lock.
 573   BufferBlob* blob = this->scratch_buffer_blob();
 574   assert(blob != NULL, "Initialize BufferBlob at start");
 575   assert(blob->size() > MAX_inst_size, "sanity");
 576   relocInfo* locs_buf = scratch_locs_memory();
 577   address blob_begin = blob->content_begin();
 578   address blob_end   = (address)locs_buf;
 579   assert(blob->contains(blob_end), "sanity");
 580   CodeBuffer buf(blob_begin, blob_end - blob_begin);
 581   buf.initialize_consts_size(_scratch_const_size);
 582   buf.initialize_stubs_size(MAX_stubs_size);
 583   assert(locs_buf != NULL, "sanity");
 584   int lsize = MAX_locs_size / 3;
 585   buf.consts()->initialize_shared_locs(&locs_buf[lsize * 0], lsize);
 586   buf.insts()->initialize_shared_locs( &locs_buf[lsize * 1], lsize);
 587   buf.stubs()->initialize_shared_locs( &locs_buf[lsize * 2], lsize);
 588   // Mark as scratch buffer.
 589   buf.consts()->set_scratch_emit();
 590   buf.insts()->set_scratch_emit();
 591   buf.stubs()->set_scratch_emit();
 592 
 593   // Do the emission.
 594 
 595   Label fakeL; // Fake label for branch instructions.
 596   Label*   saveL = NULL;
 597   uint save_bnum = 0;
 598   bool is_branch = n->is_MachBranch();
 599   if (is_branch) {
 600     MacroAssembler masm(&buf);
 601     masm.bind(fakeL);
 602     n->as_MachBranch()->save_label(&saveL, &save_bnum);
 603     n->as_MachBranch()->label_set(&fakeL, 0);
 604   }
 605   n->emit(buf, this->regalloc());
 606 
 607   // Emitting into the scratch buffer should not fail
 608   assert (!failing(), "Must not have pending failure. Reason is: %s", failure_reason());
 609 
 610   if (is_branch) // Restore label.
 611     n->as_MachBranch()->label_set(saveL, save_bnum);
 612 
 613   // End scratch_emit_size section.
 614   set_in_scratch_emit_size(false);
 615 
 616   return buf.insts_size();
 617 }
 618 
 619 
 620 // ============================================================================
 621 //------------------------------Compile standard-------------------------------
 622 debug_only( int Compile::_debug_idx = 100000; )
 623 
 624 // Compile a method.  entry_bci is -1 for normal compilations and indicates
 625 // the continuation bci for on stack replacement.
 626 
 627 
 628 Compile::Compile( ciEnv* ci_env, C2Compiler* compiler, ciMethod* target, int osr_bci,
 629                   bool subsume_loads, bool do_escape_analysis, bool eliminate_boxing, DirectiveSet* directive)
 630                 : Phase(Compiler),
 631                   _env(ci_env),
 632                   _directive(directive),
 633                   _log(ci_env->log()),
 634                   _compile_id(ci_env->compile_id()),
 635                   _save_argument_registers(false),
 636                   _stub_name(NULL),
 637                   _stub_function(NULL),
 638                   _stub_entry_point(NULL),
 639                   _method(target),
 640                   _entry_bci(osr_bci),
 641                   _initial_gvn(NULL),
 642                   _for_igvn(NULL),
 643                   _warm_calls(NULL),
 644                   _subsume_loads(subsume_loads),
 645                   _do_escape_analysis(do_escape_analysis),
 646                   _eliminate_boxing(eliminate_boxing),
 647                   _failure_reason(NULL),
 648                   _code_buffer("Compile::Fill_buffer"),
 649                   _orig_pc_slot(0),
 650                   _orig_pc_slot_offset_in_bytes(0),
 651                   _has_method_handle_invokes(false),
 652                   _mach_constant_base_node(NULL),
 653                   _node_bundling_limit(0),
 654                   _node_bundling_base(NULL),
 655                   _java_calls(0),
 656                   _inner_loops(0),
 657                   _scratch_const_size(-1),
 658                   _in_scratch_emit_size(false),
 659                   _dead_node_list(comp_arena()),
 660                   _dead_node_count(0),
 661 #ifndef PRODUCT
 662                   _trace_opto_output(directive->TraceOptoOutputOption),
 663                   _in_dump_cnt(0),
 664                   _printer(IdealGraphPrinter::printer()),
 665 #endif
 666                   _congraph(NULL),
 667                   _comp_arena(mtCompiler),
 668                   _node_arena(mtCompiler),
 669                   _old_arena(mtCompiler),
 670                   _Compile_types(mtCompiler),
 671                   _replay_inline_data(NULL),
 672                   _late_inlines(comp_arena(), 2, 0, NULL),
 673                   _string_late_inlines(comp_arena(), 2, 0, NULL),
 674                   _boxing_late_inlines(comp_arena(), 2, 0, NULL),
 675                   _late_inlines_pos(0),
 676                   _number_of_mh_late_inlines(0),
 677                   _inlining_progress(false),
 678                   _inlining_incrementally(false),
 679                   _print_inlining_list(NULL),
 680                   _print_inlining_stream(NULL),
 681                   _print_inlining_idx(0),
 682                   _print_inlining_output(NULL),
 683                   _interpreter_frame_size(0),
 684                   _max_node_limit(MaxNodeLimit),
 685                   _has_reserved_stack_access(target->has_reserved_stack_access()) {
 686   C = this;
 687 #ifndef PRODUCT
 688   if (_printer != NULL) {
 689     _printer->set_compile(this);
 690   }
 691 #endif
 692   CompileWrapper cw(this);
 693 
 694   if (CITimeVerbose) {
 695     tty->print(" ");
 696     target->holder()->name()->print();
 697     tty->print(".");
 698     target->print_short_name();
 699     tty->print("  ");
 700   }
 701   TraceTime t1("Total compilation time", &_t_totalCompilation, CITime, CITimeVerbose);
 702   TraceTime t2(NULL, &_t_methodCompilation, CITime, false);
 703 
 704 #ifndef PRODUCT
 705   bool print_opto_assembly = directive->PrintOptoAssemblyOption;
 706   if (!print_opto_assembly) {
 707     bool print_assembly = directive->PrintAssemblyOption;
 708     if (print_assembly && !Disassembler::can_decode()) {
 709       tty->print_cr("PrintAssembly request changed to PrintOptoAssembly");
 710       print_opto_assembly = true;
 711     }
 712   }
 713   set_print_assembly(print_opto_assembly);
 714   set_parsed_irreducible_loop(false);
 715 
 716   if (directive->ReplayInlineOption) {
 717     _replay_inline_data = ciReplay::load_inline_data(method(), entry_bci(), ci_env->comp_level());
 718   }
 719 #endif
 720   set_print_inlining(directive->PrintInliningOption || PrintOptoInlining);
 721   set_print_intrinsics(directive->PrintIntrinsicsOption);
 722   set_has_irreducible_loop(true); // conservative until build_loop_tree() reset it
 723 
 724   if (ProfileTraps RTM_OPT_ONLY( || UseRTMLocking )) {
 725     // Make sure the method being compiled gets its own MDO,
 726     // so we can at least track the decompile_count().
 727     // Need MDO to record RTM code generation state.
 728     method()->ensure_method_data();
 729   }
 730 
 731   Init(::AliasLevel);
 732 
 733 
 734   print_compile_messages();
 735 
 736   _ilt = InlineTree::build_inline_tree_root();
 737 
 738   // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
 739   assert(num_alias_types() >= AliasIdxRaw, "");
 740 
 741 #define MINIMUM_NODE_HASH  1023
 742   // Node list that Iterative GVN will start with
 743   Unique_Node_List for_igvn(comp_arena());
 744   set_for_igvn(&for_igvn);
 745 
 746   // GVN that will be run immediately on new nodes
 747   uint estimated_size = method()->code_size()*4+64;
 748   estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
 749   PhaseGVN gvn(node_arena(), estimated_size);
 750   set_initial_gvn(&gvn);
 751 
 752   print_inlining_init();
 753   { // Scope for timing the parser
 754     TracePhase tp("parse", &timers[_t_parser]);
 755 
 756     // Put top into the hash table ASAP.
 757     initial_gvn()->transform_no_reclaim(top());
 758 
 759     // Set up tf(), start(), and find a CallGenerator.
 760     CallGenerator* cg = NULL;
 761     if (is_osr_compilation()) {
 762       const TypeTuple *domain = StartOSRNode::osr_domain();
 763       const TypeTuple *range = TypeTuple::make_range(method()->signature());
 764       init_tf(TypeFunc::make(domain, range));
 765       StartNode* s = new StartOSRNode(root(), domain);
 766       initial_gvn()->set_type_bottom(s);
 767       init_start(s);
 768       cg = CallGenerator::for_osr(method(), entry_bci());
 769     } else {
 770       // Normal case.
 771       init_tf(TypeFunc::make(method()));
 772       StartNode* s = new StartNode(root(), tf()->domain());
 773       initial_gvn()->set_type_bottom(s);
 774       init_start(s);
 775       if (method()->intrinsic_id() == vmIntrinsics::_Reference_get && UseG1GC) {
 776         // With java.lang.ref.reference.get() we must go through the
 777         // intrinsic when G1 is enabled - even when get() is the root
 778         // method of the compile - so that, if necessary, the value in
 779         // the referent field of the reference object gets recorded by
 780         // the pre-barrier code.
 781         // Specifically, if G1 is enabled, the value in the referent
 782         // field is recorded by the G1 SATB pre barrier. This will
 783         // result in the referent being marked live and the reference
 784         // object removed from the list of discovered references during
 785         // reference processing.
 786         cg = find_intrinsic(method(), false);
 787       }
 788       if (cg == NULL) {
 789         float past_uses = method()->interpreter_invocation_count();
 790         float expected_uses = past_uses;
 791         cg = CallGenerator::for_inline(method(), expected_uses);
 792       }
 793     }
 794     if (failing())  return;
 795     if (cg == NULL) {
 796       record_method_not_compilable("cannot parse method");
 797       return;
 798     }
 799     JVMState* jvms = build_start_state(start(), tf());
 800     if ((jvms = cg->generate(jvms)) == NULL) {
 801       if (!failure_reason_is(C2Compiler::retry_class_loading_during_parsing())) {
 802         record_method_not_compilable("method parse failed");
 803       }
 804       return;
 805     }
 806     GraphKit kit(jvms);
 807 
 808     if (!kit.stopped()) {
 809       // Accept return values, and transfer control we know not where.
 810       // This is done by a special, unique ReturnNode bound to root.
 811       return_values(kit.jvms());
 812     }
 813 
 814     if (kit.has_exceptions()) {
 815       // Any exceptions that escape from this call must be rethrown
 816       // to whatever caller is dynamically above us on the stack.
 817       // This is done by a special, unique RethrowNode bound to root.
 818       rethrow_exceptions(kit.transfer_exceptions_into_jvms());
 819     }
 820 
 821     assert(IncrementalInline || (_late_inlines.length() == 0 && !has_mh_late_inlines()), "incremental inlining is off");
 822 
 823     if (_late_inlines.length() == 0 && !has_mh_late_inlines() && !failing() && has_stringbuilder()) {
 824       inline_string_calls(true);
 825     }
 826 
 827     if (failing())  return;
 828 
 829     print_method(PHASE_BEFORE_REMOVEUSELESS, 3);
 830 
 831     // Remove clutter produced by parsing.
 832     if (!failing()) {
 833       ResourceMark rm;
 834       PhaseRemoveUseless pru(initial_gvn(), &for_igvn);
 835     }
 836   }
 837 
 838   // Note:  Large methods are capped off in do_one_bytecode().
 839   if (failing())  return;
 840 
 841   // After parsing, node notes are no longer automagic.
 842   // They must be propagated by register_new_node_with_optimizer(),
 843   // clone(), or the like.
 844   set_default_node_notes(NULL);
 845 
 846   for (;;) {
 847     int successes = Inline_Warm();
 848     if (failing())  return;
 849     if (successes == 0)  break;
 850   }
 851 
 852   // Drain the list.
 853   Finish_Warm();
 854 #ifndef PRODUCT
 855   if (_printer && _printer->should_print(1)) {
 856     _printer->print_inlining();
 857   }
 858 #endif
 859 
 860   if (failing())  return;
 861   NOT_PRODUCT( verify_graph_edges(); )
 862 
 863   // Now optimize
 864   Optimize();
 865   if (failing())  return;
 866   NOT_PRODUCT( verify_graph_edges(); )
 867 
 868 #ifndef PRODUCT
 869   if (PrintIdeal) {
 870     ttyLocker ttyl;  // keep the following output all in one block
 871     // This output goes directly to the tty, not the compiler log.
 872     // To enable tools to match it up with the compilation activity,
 873     // be sure to tag this tty output with the compile ID.
 874     if (xtty != NULL) {
 875       xtty->head("ideal compile_id='%d'%s", compile_id(),
 876                  is_osr_compilation()    ? " compile_kind='osr'" :
 877                  "");
 878     }
 879     root()->dump(9999);
 880     if (xtty != NULL) {
 881       xtty->tail("ideal");
 882     }
 883   }
 884 #endif
 885 
 886   NOT_PRODUCT( verify_barriers(); )
 887 
 888   // Dump compilation data to replay it.
 889   if (directive->DumpReplayOption) {
 890     env()->dump_replay_data(_compile_id);
 891   }
 892   if (directive->DumpInlineOption && (ilt() != NULL)) {
 893     env()->dump_inline_data(_compile_id);
 894   }
 895 
 896   // Now that we know the size of all the monitors we can add a fixed slot
 897   // for the original deopt pc.
 898 
 899   _orig_pc_slot =  fixed_slots();
 900   int next_slot = _orig_pc_slot + (sizeof(address) / VMRegImpl::stack_slot_size);
 901   set_fixed_slots(next_slot);
 902 
 903   // Compute when to use implicit null checks. Used by matching trap based
 904   // nodes and NullCheck optimization.
 905   set_allowed_deopt_reasons();
 906 
 907   // Now generate code
 908   Code_Gen();
 909   if (failing())  return;
 910 
 911   // Check if we want to skip execution of all compiled code.
 912   {
 913 #ifndef PRODUCT
 914     if (OptoNoExecute) {
 915       record_method_not_compilable("+OptoNoExecute");  // Flag as failed
 916       return;
 917     }
 918 #endif
 919     TracePhase tp("install_code", &timers[_t_registerMethod]);
 920 
 921     if (is_osr_compilation()) {
 922       _code_offsets.set_value(CodeOffsets::Verified_Entry, 0);
 923       _code_offsets.set_value(CodeOffsets::OSR_Entry, _first_block_size);
 924     } else {
 925       _code_offsets.set_value(CodeOffsets::Verified_Entry, _first_block_size);
 926       _code_offsets.set_value(CodeOffsets::OSR_Entry, 0);
 927     }
 928 
 929     env()->register_method(_method, _entry_bci,
 930                            &_code_offsets,
 931                            _orig_pc_slot_offset_in_bytes,
 932                            code_buffer(),
 933                            frame_size_in_words(), _oop_map_set,
 934                            &_handler_table, &_inc_table,
 935                            compiler,
 936                            has_unsafe_access(),
 937                            SharedRuntime::is_wide_vector(max_vector_size()),
 938                            rtm_state()
 939                            );
 940 
 941     if (log() != NULL) // Print code cache state into compiler log
 942       log()->code_cache_state();
 943   }
 944 }
 945 
 946 //------------------------------Compile----------------------------------------
 947 // Compile a runtime stub
 948 Compile::Compile( ciEnv* ci_env,
 949                   TypeFunc_generator generator,
 950                   address stub_function,
 951                   const char *stub_name,
 952                   int is_fancy_jump,
 953                   bool pass_tls,
 954                   bool save_arg_registers,
 955                   bool return_pc,
 956                   DirectiveSet* directive)
 957   : Phase(Compiler),
 958     _env(ci_env),
 959     _directive(directive),
 960     _log(ci_env->log()),
 961     _compile_id(0),
 962     _save_argument_registers(save_arg_registers),
 963     _method(NULL),
 964     _stub_name(stub_name),
 965     _stub_function(stub_function),
 966     _stub_entry_point(NULL),
 967     _entry_bci(InvocationEntryBci),
 968     _initial_gvn(NULL),
 969     _for_igvn(NULL),
 970     _warm_calls(NULL),
 971     _orig_pc_slot(0),
 972     _orig_pc_slot_offset_in_bytes(0),
 973     _subsume_loads(true),
 974     _do_escape_analysis(false),
 975     _eliminate_boxing(false),
 976     _failure_reason(NULL),
 977     _code_buffer("Compile::Fill_buffer"),
 978     _has_method_handle_invokes(false),
 979     _mach_constant_base_node(NULL),
 980     _node_bundling_limit(0),
 981     _node_bundling_base(NULL),
 982     _java_calls(0),
 983     _inner_loops(0),
 984 #ifndef PRODUCT
 985     _trace_opto_output(directive->TraceOptoOutputOption),
 986     _in_dump_cnt(0),
 987     _printer(NULL),
 988 #endif
 989     _comp_arena(mtCompiler),
 990     _node_arena(mtCompiler),
 991     _old_arena(mtCompiler),
 992     _Compile_types(mtCompiler),
 993     _dead_node_list(comp_arena()),
 994     _dead_node_count(0),
 995     _congraph(NULL),
 996     _replay_inline_data(NULL),
 997     _number_of_mh_late_inlines(0),
 998     _inlining_progress(false),
 999     _inlining_incrementally(false),
1000     _print_inlining_list(NULL),
1001     _print_inlining_stream(NULL),
1002     _print_inlining_idx(0),
1003     _print_inlining_output(NULL),
1004     _allowed_reasons(0),
1005     _interpreter_frame_size(0),
1006     _max_node_limit(MaxNodeLimit),
1007     _has_reserved_stack_access(false) {
1008   C = this;
1009 
1010   TraceTime t1(NULL, &_t_totalCompilation, CITime, false);
1011   TraceTime t2(NULL, &_t_stubCompilation, CITime, false);
1012 
1013 #ifndef PRODUCT
1014   set_print_assembly(PrintFrameConverterAssembly);
1015   set_parsed_irreducible_loop(false);
1016 #endif
1017   set_has_irreducible_loop(false); // no loops
1018 
1019   CompileWrapper cw(this);
1020   Init(/*AliasLevel=*/ 0);
1021   init_tf((*generator)());
1022 
1023   {
1024     // The following is a dummy for the sake of GraphKit::gen_stub
1025     Unique_Node_List for_igvn(comp_arena());
1026     set_for_igvn(&for_igvn);  // not used, but some GraphKit guys push on this
1027     PhaseGVN gvn(Thread::current()->resource_area(),255);
1028     set_initial_gvn(&gvn);    // not significant, but GraphKit guys use it pervasively
1029     gvn.transform_no_reclaim(top());
1030 
1031     GraphKit kit;
1032     kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
1033   }
1034 
1035   NOT_PRODUCT( verify_graph_edges(); )
1036   Code_Gen();
1037   if (failing())  return;
1038 
1039 
1040   // Entry point will be accessed using compile->stub_entry_point();
1041   if (code_buffer() == NULL) {
1042     Matcher::soft_match_failure();
1043   } else {
1044     if (PrintAssembly && (WizardMode || Verbose))
1045       tty->print_cr("### Stub::%s", stub_name);
1046 
1047     if (!failing()) {
1048       assert(_fixed_slots == 0, "no fixed slots used for runtime stubs");
1049 
1050       // Make the NMethod
1051       // For now we mark the frame as never safe for profile stackwalking
1052       RuntimeStub *rs = RuntimeStub::new_runtime_stub(stub_name,
1053                                                       code_buffer(),
1054                                                       CodeOffsets::frame_never_safe,
1055                                                       // _code_offsets.value(CodeOffsets::Frame_Complete),
1056                                                       frame_size_in_words(),
1057                                                       _oop_map_set,
1058                                                       save_arg_registers);
1059       assert(rs != NULL && rs->is_runtime_stub(), "sanity check");
1060 
1061       _stub_entry_point = rs->entry_point();
1062     }
1063   }
1064 }
1065 
1066 //------------------------------Init-------------------------------------------
1067 // Prepare for a single compilation
1068 void Compile::Init(int aliaslevel) {
1069   _unique  = 0;
1070   _regalloc = NULL;
1071 
1072   _tf      = NULL;  // filled in later
1073   _top     = NULL;  // cached later
1074   _matcher = NULL;  // filled in later
1075   _cfg     = NULL;  // filled in later
1076 
1077   set_24_bit_selection_and_mode(Use24BitFP, false);
1078 
1079   _node_note_array = NULL;
1080   _default_node_notes = NULL;
1081   DEBUG_ONLY( _modified_nodes = NULL; ) // Used in Optimize()
1082 
1083   _immutable_memory = NULL; // filled in at first inquiry
1084 
1085   // Globally visible Nodes
1086   // First set TOP to NULL to give safe behavior during creation of RootNode
1087   set_cached_top_node(NULL);
1088   set_root(new RootNode());
1089   // Now that you have a Root to point to, create the real TOP
1090   set_cached_top_node( new ConNode(Type::TOP) );
1091   set_recent_alloc(NULL, NULL);
1092 
1093   // Create Debug Information Recorder to record scopes, oopmaps, etc.
1094   env()->set_oop_recorder(new OopRecorder(env()->arena()));
1095   env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
1096   env()->set_dependencies(new Dependencies(env()));
1097 
1098   _fixed_slots = 0;
1099   set_has_split_ifs(false);
1100   set_has_loops(has_method() && method()->has_loops()); // first approximation
1101   set_has_stringbuilder(false);
1102   set_has_boxed_value(false);
1103   _trap_can_recompile = false;  // no traps emitted yet
1104   _major_progress = true; // start out assuming good things will happen
1105   set_has_unsafe_access(false);
1106   set_max_vector_size(0);
1107   set_clear_upper_avx(false);  //false as default for clear upper bits of ymm registers
1108   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
1109   set_decompile_count(0);
1110 
1111   set_do_freq_based_layout(_directive->BlockLayoutByFrequencyOption);
1112   set_num_loop_opts(LoopOptsCount);
1113   set_do_inlining(Inline);
1114   set_max_inline_size(MaxInlineSize);
1115   set_freq_inline_size(FreqInlineSize);
1116   set_do_scheduling(OptoScheduling);
1117   set_do_count_invocations(false);
1118   set_do_method_data_update(false);
1119 
1120   set_do_vector_loop(false);
1121 
1122   if (AllowVectorizeOnDemand) {
1123     if (has_method() && (_directive->VectorizeOption || _directive->VectorizeDebugOption)) {
1124       set_do_vector_loop(true);
1125       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());})
1126     } else if (has_method() && method()->name() != 0 &&
1127                method()->intrinsic_id() == vmIntrinsics::_forEachRemaining) {
1128       set_do_vector_loop(true);
1129     }
1130   }
1131   set_use_cmove(UseCMoveUnconditionally /* || do_vector_loop()*/); //TODO: consider do_vector_loop() mandate use_cmove unconditionally
1132   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());})
1133 
1134   set_age_code(has_method() && method()->profile_aging());
1135   set_rtm_state(NoRTM); // No RTM lock eliding by default
1136   _max_node_limit = _directive->MaxNodeLimitOption;
1137 
1138 #if INCLUDE_RTM_OPT
1139   if (UseRTMLocking && has_method() && (method()->method_data_or_null() != NULL)) {
1140     int rtm_state = method()->method_data()->rtm_state();
1141     if (method_has_option("NoRTMLockEliding") || ((rtm_state & NoRTM) != 0)) {
1142       // Don't generate RTM lock eliding code.
1143       set_rtm_state(NoRTM);
1144     } else if (method_has_option("UseRTMLockEliding") || ((rtm_state & UseRTM) != 0) || !UseRTMDeopt) {
1145       // Generate RTM lock eliding code without abort ratio calculation code.
1146       set_rtm_state(UseRTM);
1147     } else if (UseRTMDeopt) {
1148       // Generate RTM lock eliding code and include abort ratio calculation
1149       // code if UseRTMDeopt is on.
1150       set_rtm_state(ProfileRTM);
1151     }
1152   }
1153 #endif
1154   if (debug_info()->recording_non_safepoints()) {
1155     set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
1156                         (comp_arena(), 8, 0, NULL));
1157     set_default_node_notes(Node_Notes::make(this));
1158   }
1159 
1160   // // -- Initialize types before each compile --
1161   // // Update cached type information
1162   // if( _method && _method->constants() )
1163   //   Type::update_loaded_types(_method, _method->constants());
1164 
1165   // Init alias_type map.
1166   if (!_do_escape_analysis && aliaslevel == 3)
1167     aliaslevel = 2;  // No unique types without escape analysis
1168   _AliasLevel = aliaslevel;
1169   const int grow_ats = 16;
1170   _max_alias_types = grow_ats;
1171   _alias_types   = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
1172   AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType,  grow_ats);
1173   Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
1174   {
1175     for (int i = 0; i < grow_ats; i++)  _alias_types[i] = &ats[i];
1176   }
1177   // Initialize the first few types.
1178   _alias_types[AliasIdxTop]->Init(AliasIdxTop, NULL);
1179   _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
1180   _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
1181   _num_alias_types = AliasIdxRaw+1;
1182   // Zero out the alias type cache.
1183   Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
1184   // A NULL adr_type hits in the cache right away.  Preload the right answer.
1185   probe_alias_cache(NULL)->_index = AliasIdxTop;
1186 
1187   _intrinsics = NULL;
1188   _macro_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1189   _predicate_opaqs = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1190   _expensive_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1191   _range_check_casts = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1192   _opaque4_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1193   register_library_intrinsics();
1194 }
1195 
1196 //---------------------------init_start----------------------------------------
1197 // Install the StartNode on this compile object.
1198 void Compile::init_start(StartNode* s) {
1199   if (failing())
1200     return; // already failing
1201   assert(s == start(), "");
1202 }
1203 
1204 /**
1205  * Return the 'StartNode'. We must not have a pending failure, since the ideal graph
1206  * can be in an inconsistent state, i.e., we can get segmentation faults when traversing
1207  * the ideal graph.
1208  */
1209 StartNode* Compile::start() const {
1210   assert (!failing(), "Must not have pending failure. Reason is: %s", failure_reason());
1211   for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
1212     Node* start = root()->fast_out(i);
1213     if (start->is_Start()) {
1214       return start->as_Start();
1215     }
1216   }
1217   fatal("Did not find Start node!");
1218   return NULL;
1219 }
1220 
1221 //-------------------------------immutable_memory-------------------------------------
1222 // Access immutable memory
1223 Node* Compile::immutable_memory() {
1224   if (_immutable_memory != NULL) {
1225     return _immutable_memory;
1226   }
1227   StartNode* s = start();
1228   for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
1229     Node *p = s->fast_out(i);
1230     if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
1231       _immutable_memory = p;
1232       return _immutable_memory;
1233     }
1234   }
1235   ShouldNotReachHere();
1236   return NULL;
1237 }
1238 
1239 //----------------------set_cached_top_node------------------------------------
1240 // Install the cached top node, and make sure Node::is_top works correctly.
1241 void Compile::set_cached_top_node(Node* tn) {
1242   if (tn != NULL)  verify_top(tn);
1243   Node* old_top = _top;
1244   _top = tn;
1245   // Calling Node::setup_is_top allows the nodes the chance to adjust
1246   // their _out arrays.
1247   if (_top != NULL)     _top->setup_is_top();
1248   if (old_top != NULL)  old_top->setup_is_top();
1249   assert(_top == NULL || top()->is_top(), "");
1250 }
1251 
1252 #ifdef ASSERT
1253 uint Compile::count_live_nodes_by_graph_walk() {
1254   Unique_Node_List useful(comp_arena());
1255   // Get useful node list by walking the graph.
1256   identify_useful_nodes(useful);
1257   return useful.size();
1258 }
1259 
1260 void Compile::print_missing_nodes() {
1261 
1262   // Return if CompileLog is NULL and PrintIdealNodeCount is false.
1263   if ((_log == NULL) && (! PrintIdealNodeCount)) {
1264     return;
1265   }
1266 
1267   // This is an expensive function. It is executed only when the user
1268   // specifies VerifyIdealNodeCount option or otherwise knows the
1269   // additional work that needs to be done to identify reachable nodes
1270   // by walking the flow graph and find the missing ones using
1271   // _dead_node_list.
1272 
1273   Unique_Node_List useful(comp_arena());
1274   // Get useful node list by walking the graph.
1275   identify_useful_nodes(useful);
1276 
1277   uint l_nodes = C->live_nodes();
1278   uint l_nodes_by_walk = useful.size();
1279 
1280   if (l_nodes != l_nodes_by_walk) {
1281     if (_log != NULL) {
1282       _log->begin_head("mismatched_nodes count='%d'", abs((int) (l_nodes - l_nodes_by_walk)));
1283       _log->stamp();
1284       _log->end_head();
1285     }
1286     VectorSet& useful_member_set = useful.member_set();
1287     int last_idx = l_nodes_by_walk;
1288     for (int i = 0; i < last_idx; i++) {
1289       if (useful_member_set.test(i)) {
1290         if (_dead_node_list.test(i)) {
1291           if (_log != NULL) {
1292             _log->elem("mismatched_node_info node_idx='%d' type='both live and dead'", i);
1293           }
1294           if (PrintIdealNodeCount) {
1295             // Print the log message to tty
1296               tty->print_cr("mismatched_node idx='%d' both live and dead'", i);
1297               useful.at(i)->dump();
1298           }
1299         }
1300       }
1301       else if (! _dead_node_list.test(i)) {
1302         if (_log != NULL) {
1303           _log->elem("mismatched_node_info node_idx='%d' type='neither live nor dead'", i);
1304         }
1305         if (PrintIdealNodeCount) {
1306           // Print the log message to tty
1307           tty->print_cr("mismatched_node idx='%d' type='neither live nor dead'", i);
1308         }
1309       }
1310     }
1311     if (_log != NULL) {
1312       _log->tail("mismatched_nodes");
1313     }
1314   }
1315 }
1316 void Compile::record_modified_node(Node* n) {
1317   if (_modified_nodes != NULL && !_inlining_incrementally &&
1318       n->outcnt() != 0 && !n->is_Con()) {
1319     _modified_nodes->push(n);
1320   }
1321 }
1322 
1323 void Compile::remove_modified_node(Node* n) {
1324   if (_modified_nodes != NULL) {
1325     _modified_nodes->remove(n);
1326   }
1327 }
1328 #endif
1329 
1330 #ifndef PRODUCT
1331 void Compile::verify_top(Node* tn) const {
1332   if (tn != NULL) {
1333     assert(tn->is_Con(), "top node must be a constant");
1334     assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
1335     assert(tn->in(0) != NULL, "must have live top node");
1336   }
1337 }
1338 #endif
1339 
1340 
1341 ///-------------------Managing Per-Node Debug & Profile Info-------------------
1342 
1343 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
1344   guarantee(arr != NULL, "");
1345   int num_blocks = arr->length();
1346   if (grow_by < num_blocks)  grow_by = num_blocks;
1347   int num_notes = grow_by * _node_notes_block_size;
1348   Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
1349   Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
1350   while (num_notes > 0) {
1351     arr->append(notes);
1352     notes     += _node_notes_block_size;
1353     num_notes -= _node_notes_block_size;
1354   }
1355   assert(num_notes == 0, "exact multiple, please");
1356 }
1357 
1358 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
1359   if (source == NULL || dest == NULL)  return false;
1360 
1361   if (dest->is_Con())
1362     return false;               // Do not push debug info onto constants.
1363 
1364 #ifdef ASSERT
1365   // Leave a bread crumb trail pointing to the original node:
1366   if (dest != NULL && dest != source && dest->debug_orig() == NULL) {
1367     dest->set_debug_orig(source);
1368   }
1369 #endif
1370 
1371   if (node_note_array() == NULL)
1372     return false;               // Not collecting any notes now.
1373 
1374   // This is a copy onto a pre-existing node, which may already have notes.
1375   // If both nodes have notes, do not overwrite any pre-existing notes.
1376   Node_Notes* source_notes = node_notes_at(source->_idx);
1377   if (source_notes == NULL || source_notes->is_clear())  return false;
1378   Node_Notes* dest_notes   = node_notes_at(dest->_idx);
1379   if (dest_notes == NULL || dest_notes->is_clear()) {
1380     return set_node_notes_at(dest->_idx, source_notes);
1381   }
1382 
1383   Node_Notes merged_notes = (*source_notes);
1384   // The order of operations here ensures that dest notes will win...
1385   merged_notes.update_from(dest_notes);
1386   return set_node_notes_at(dest->_idx, &merged_notes);
1387 }
1388 
1389 
1390 //--------------------------allow_range_check_smearing-------------------------
1391 // Gating condition for coalescing similar range checks.
1392 // Sometimes we try 'speculatively' replacing a series of a range checks by a
1393 // single covering check that is at least as strong as any of them.
1394 // If the optimization succeeds, the simplified (strengthened) range check
1395 // will always succeed.  If it fails, we will deopt, and then give up
1396 // on the optimization.
1397 bool Compile::allow_range_check_smearing() const {
1398   // If this method has already thrown a range-check,
1399   // assume it was because we already tried range smearing
1400   // and it failed.
1401   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
1402   return !already_trapped;
1403 }
1404 
1405 
1406 //------------------------------flatten_alias_type-----------------------------
1407 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
1408   int offset = tj->offset();
1409   TypePtr::PTR ptr = tj->ptr();
1410 
1411   // Known instance (scalarizable allocation) alias only with itself.
1412   bool is_known_inst = tj->isa_oopptr() != NULL &&
1413                        tj->is_oopptr()->is_known_instance();
1414 
1415   // Process weird unsafe references.
1416   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
1417     assert(InlineUnsafeOps, "indeterminate pointers come only from unsafe ops");
1418     assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
1419     tj = TypeOopPtr::BOTTOM;
1420     ptr = tj->ptr();
1421     offset = tj->offset();
1422   }
1423 
1424   // Array pointers need some flattening
1425   const TypeAryPtr *ta = tj->isa_aryptr();
1426   if (ta && ta->is_stable()) {
1427     // Erase stability property for alias analysis.
1428     tj = ta = ta->cast_to_stable(false);
1429   }
1430   if( ta && is_known_inst ) {
1431     if ( offset != Type::OffsetBot &&
1432          offset > arrayOopDesc::length_offset_in_bytes() ) {
1433       offset = Type::OffsetBot; // Flatten constant access into array body only
1434       tj = ta = TypeAryPtr::make(ptr, ta->ary(), ta->klass(), true, offset, ta->instance_id());
1435     }
1436   } else if( ta && _AliasLevel >= 2 ) {
1437     // For arrays indexed by constant indices, we flatten the alias
1438     // space to include all of the array body.  Only the header, klass
1439     // and array length can be accessed un-aliased.
1440     if( offset != Type::OffsetBot ) {
1441       if( ta->const_oop() ) { // MethodData* or Method*
1442         offset = Type::OffsetBot;   // Flatten constant access into array body
1443         tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),ta->ary(),ta->klass(),false,offset);
1444       } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
1445         // range is OK as-is.
1446         tj = ta = TypeAryPtr::RANGE;
1447       } else if( offset == oopDesc::klass_offset_in_bytes() ) {
1448         tj = TypeInstPtr::KLASS; // all klass loads look alike
1449         ta = TypeAryPtr::RANGE; // generic ignored junk
1450         ptr = TypePtr::BotPTR;
1451       } else if( offset == oopDesc::mark_offset_in_bytes() ) {
1452         tj = TypeInstPtr::MARK;
1453         ta = TypeAryPtr::RANGE; // generic ignored junk
1454         ptr = TypePtr::BotPTR;
1455       } else {                  // Random constant offset into array body
1456         offset = Type::OffsetBot;   // Flatten constant access into array body
1457         tj = ta = TypeAryPtr::make(ptr,ta->ary(),ta->klass(),false,offset);
1458       }
1459     }
1460     // Arrays of fixed size alias with arrays of unknown size.
1461     if (ta->size() != TypeInt::POS) {
1462       const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
1463       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,ta->klass(),false,offset);
1464     }
1465     // Arrays of known objects become arrays of unknown objects.
1466     if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
1467       const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
1468       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1469     }
1470     if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
1471       const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
1472       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1473     }
1474     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
1475     // cannot be distinguished by bytecode alone.
1476     if (ta->elem() == TypeInt::BOOL) {
1477       const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
1478       ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
1479       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,offset);
1480     }
1481     // During the 2nd round of IterGVN, NotNull castings are removed.
1482     // Make sure the Bottom and NotNull variants alias the same.
1483     // Also, make sure exact and non-exact variants alias the same.
1484     if (ptr == TypePtr::NotNull || ta->klass_is_exact() || ta->speculative() != NULL) {
1485       tj = ta = TypeAryPtr::make(TypePtr::BotPTR,ta->ary(),ta->klass(),false,offset);
1486     }
1487   }
1488 
1489   // Oop pointers need some flattening
1490   const TypeInstPtr *to = tj->isa_instptr();
1491   if( to && _AliasLevel >= 2 && to != TypeOopPtr::BOTTOM ) {
1492     ciInstanceKlass *k = to->klass()->as_instance_klass();
1493     if( ptr == TypePtr::Constant ) {
1494       if (to->klass() != ciEnv::current()->Class_klass() ||
1495           offset < k->size_helper() * wordSize) {
1496         // No constant oop pointers (such as Strings); they alias with
1497         // unknown strings.
1498         assert(!is_known_inst, "not scalarizable allocation");
1499         tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1500       }
1501     } else if( is_known_inst ) {
1502       tj = to; // Keep NotNull and klass_is_exact for instance type
1503     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
1504       // During the 2nd round of IterGVN, NotNull castings are removed.
1505       // Make sure the Bottom and NotNull variants alias the same.
1506       // Also, make sure exact and non-exact variants alias the same.
1507       tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1508     }
1509     if (to->speculative() != NULL) {
1510       tj = to = TypeInstPtr::make(to->ptr(),to->klass(),to->klass_is_exact(),to->const_oop(),to->offset(), to->instance_id());
1511     }
1512     // Canonicalize the holder of this field
1513     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
1514       // First handle header references such as a LoadKlassNode, even if the
1515       // object's klass is unloaded at compile time (4965979).
1516       if (!is_known_inst) { // Do it only for non-instance types
1517         tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, NULL, offset);
1518       }
1519     } else if (offset < 0 || offset >= k->size_helper() * wordSize) {
1520       // Static fields are in the space above the normal instance
1521       // fields in the java.lang.Class instance.
1522       if (to->klass() != ciEnv::current()->Class_klass()) {
1523         to = NULL;
1524         tj = TypeOopPtr::BOTTOM;
1525         offset = tj->offset();
1526       }
1527     } else {
1528       ciInstanceKlass *canonical_holder = k->get_canonical_holder(offset);
1529       if (!k->equals(canonical_holder) || tj->offset() != offset) {
1530         if( is_known_inst ) {
1531           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, true, NULL, offset, to->instance_id());
1532         } else {
1533           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, false, NULL, offset);
1534         }
1535       }
1536     }
1537   }
1538 
1539   // Klass pointers to object array klasses need some flattening
1540   const TypeKlassPtr *tk = tj->isa_klassptr();
1541   if( tk ) {
1542     // If we are referencing a field within a Klass, we need
1543     // to assume the worst case of an Object.  Both exact and
1544     // inexact types must flatten to the same alias class so
1545     // use NotNull as the PTR.
1546     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
1547 
1548       tj = tk = TypeKlassPtr::make(TypePtr::NotNull,
1549                                    TypeKlassPtr::OBJECT->klass(),
1550                                    offset);
1551     }
1552 
1553     ciKlass* klass = tk->klass();
1554     if( klass->is_obj_array_klass() ) {
1555       ciKlass* k = TypeAryPtr::OOPS->klass();
1556       if( !k || !k->is_loaded() )                  // Only fails for some -Xcomp runs
1557         k = TypeInstPtr::BOTTOM->klass();
1558       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, k, offset );
1559     }
1560 
1561     // Check for precise loads from the primary supertype array and force them
1562     // to the supertype cache alias index.  Check for generic array loads from
1563     // the primary supertype array and also force them to the supertype cache
1564     // alias index.  Since the same load can reach both, we need to merge
1565     // these 2 disparate memories into the same alias class.  Since the
1566     // primary supertype array is read-only, there's no chance of confusion
1567     // where we bypass an array load and an array store.
1568     int primary_supers_offset = in_bytes(Klass::primary_supers_offset());
1569     if (offset == Type::OffsetBot ||
1570         (offset >= primary_supers_offset &&
1571          offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
1572         offset == (int)in_bytes(Klass::secondary_super_cache_offset())) {
1573       offset = in_bytes(Klass::secondary_super_cache_offset());
1574       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, tk->klass(), offset );
1575     }
1576   }
1577 
1578   // Flatten all Raw pointers together.
1579   if (tj->base() == Type::RawPtr)
1580     tj = TypeRawPtr::BOTTOM;
1581 
1582   if (tj->base() == Type::AnyPtr)
1583     tj = TypePtr::BOTTOM;      // An error, which the caller must check for.
1584 
1585   // Flatten all to bottom for now
1586   switch( _AliasLevel ) {
1587   case 0:
1588     tj = TypePtr::BOTTOM;
1589     break;
1590   case 1:                       // Flatten to: oop, static, field or array
1591     switch (tj->base()) {
1592     //case Type::AryPtr: tj = TypeAryPtr::RANGE;    break;
1593     case Type::RawPtr:   tj = TypeRawPtr::BOTTOM;   break;
1594     case Type::AryPtr:   // do not distinguish arrays at all
1595     case Type::InstPtr:  tj = TypeInstPtr::BOTTOM;  break;
1596     case Type::KlassPtr: tj = TypeKlassPtr::OBJECT; break;
1597     case Type::AnyPtr:   tj = TypePtr::BOTTOM;      break;  // caller checks it
1598     default: ShouldNotReachHere();
1599     }
1600     break;
1601   case 2:                       // No collapsing at level 2; keep all splits
1602   case 3:                       // No collapsing at level 3; keep all splits
1603     break;
1604   default:
1605     Unimplemented();
1606   }
1607 
1608   offset = tj->offset();
1609   assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
1610 
1611   assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
1612           (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
1613           (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
1614           (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
1615           (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1616           (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1617           (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr)  ,
1618           "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
1619   assert( tj->ptr() != TypePtr::TopPTR &&
1620           tj->ptr() != TypePtr::AnyNull &&
1621           tj->ptr() != TypePtr::Null, "No imprecise addresses" );
1622 //    assert( tj->ptr() != TypePtr::Constant ||
1623 //            tj->base() == Type::RawPtr ||
1624 //            tj->base() == Type::KlassPtr, "No constant oop addresses" );
1625 
1626   return tj;
1627 }
1628 
1629 void Compile::AliasType::Init(int i, const TypePtr* at) {
1630   _index = i;
1631   _adr_type = at;
1632   _field = NULL;
1633   _element = NULL;
1634   _is_rewritable = true; // default
1635   const TypeOopPtr *atoop = (at != NULL) ? at->isa_oopptr() : NULL;
1636   if (atoop != NULL && atoop->is_known_instance()) {
1637     const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
1638     _general_index = Compile::current()->get_alias_index(gt);
1639   } else {
1640     _general_index = 0;
1641   }
1642 }
1643 
1644 BasicType Compile::AliasType::basic_type() const {
1645   if (element() != NULL) {
1646     const Type* element = adr_type()->is_aryptr()->elem();
1647     return element->isa_narrowoop() ? T_OBJECT : element->array_element_basic_type();
1648   } if (field() != NULL) {
1649     return field()->layout_type();
1650   } else {
1651     return T_ILLEGAL; // unknown
1652   }
1653 }
1654 
1655 //---------------------------------print_on------------------------------------
1656 #ifndef PRODUCT
1657 void Compile::AliasType::print_on(outputStream* st) {
1658   if (index() < 10)
1659         st->print("@ <%d> ", index());
1660   else  st->print("@ <%d>",  index());
1661   st->print(is_rewritable() ? "   " : " RO");
1662   int offset = adr_type()->offset();
1663   if (offset == Type::OffsetBot)
1664         st->print(" +any");
1665   else  st->print(" +%-3d", offset);
1666   st->print(" in ");
1667   adr_type()->dump_on(st);
1668   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
1669   if (field() != NULL && tjp) {
1670     if (tjp->klass()  != field()->holder() ||
1671         tjp->offset() != field()->offset_in_bytes()) {
1672       st->print(" != ");
1673       field()->print();
1674       st->print(" ***");
1675     }
1676   }
1677 }
1678 
1679 void print_alias_types() {
1680   Compile* C = Compile::current();
1681   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
1682   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
1683     C->alias_type(idx)->print_on(tty);
1684     tty->cr();
1685   }
1686 }
1687 #endif
1688 
1689 
1690 //----------------------------probe_alias_cache--------------------------------
1691 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
1692   intptr_t key = (intptr_t) adr_type;
1693   key ^= key >> logAliasCacheSize;
1694   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
1695 }
1696 
1697 
1698 //-----------------------------grow_alias_types--------------------------------
1699 void Compile::grow_alias_types() {
1700   const int old_ats  = _max_alias_types; // how many before?
1701   const int new_ats  = old_ats;          // how many more?
1702   const int grow_ats = old_ats+new_ats;  // how many now?
1703   _max_alias_types = grow_ats;
1704   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
1705   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
1706   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
1707   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
1708 }
1709 
1710 
1711 //--------------------------------find_alias_type------------------------------
1712 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field) {
1713   if (_AliasLevel == 0)
1714     return alias_type(AliasIdxBot);
1715 
1716   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1717   if (ace->_adr_type == adr_type) {
1718     return alias_type(ace->_index);
1719   }
1720 
1721   // Handle special cases.
1722   if (adr_type == NULL)             return alias_type(AliasIdxTop);
1723   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
1724 
1725   // Do it the slow way.
1726   const TypePtr* flat = flatten_alias_type(adr_type);
1727 
1728 #ifdef ASSERT
1729   {
1730     ResourceMark rm;
1731     assert(flat == flatten_alias_type(flat), "not idempotent: adr_type = %s; flat = %s => %s",
1732            Type::str(adr_type), Type::str(flat), Type::str(flatten_alias_type(flat)));
1733     assert(flat != TypePtr::BOTTOM, "cannot alias-analyze an untyped ptr: adr_type = %s",
1734            Type::str(adr_type));
1735     if (flat->isa_oopptr() && !flat->isa_klassptr()) {
1736       const TypeOopPtr* foop = flat->is_oopptr();
1737       // Scalarizable allocations have exact klass always.
1738       bool exact = !foop->klass_is_exact() || foop->is_known_instance();
1739       const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
1740       assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type: foop = %s; xoop = %s",
1741              Type::str(foop), Type::str(xoop));
1742     }
1743   }
1744 #endif
1745 
1746   int idx = AliasIdxTop;
1747   for (int i = 0; i < num_alias_types(); i++) {
1748     if (alias_type(i)->adr_type() == flat) {
1749       idx = i;
1750       break;
1751     }
1752   }
1753 
1754   if (idx == AliasIdxTop) {
1755     if (no_create)  return NULL;
1756     // Grow the array if necessary.
1757     if (_num_alias_types == _max_alias_types)  grow_alias_types();
1758     // Add a new alias type.
1759     idx = _num_alias_types++;
1760     _alias_types[idx]->Init(idx, flat);
1761     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
1762     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
1763     if (flat->isa_instptr()) {
1764       if (flat->offset() == java_lang_Class::klass_offset_in_bytes()
1765           && flat->is_instptr()->klass() == env()->Class_klass())
1766         alias_type(idx)->set_rewritable(false);
1767     }
1768     if (flat->isa_aryptr()) {
1769 #ifdef ASSERT
1770       const int header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1771       // (T_BYTE has the weakest alignment and size restrictions...)
1772       assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
1773 #endif
1774       if (flat->offset() == TypePtr::OffsetBot) {
1775         alias_type(idx)->set_element(flat->is_aryptr()->elem());
1776       }
1777     }
1778     if (flat->isa_klassptr()) {
1779       if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
1780         alias_type(idx)->set_rewritable(false);
1781       if (flat->offset() == in_bytes(Klass::modifier_flags_offset()))
1782         alias_type(idx)->set_rewritable(false);
1783       if (flat->offset() == in_bytes(Klass::access_flags_offset()))
1784         alias_type(idx)->set_rewritable(false);
1785       if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
1786         alias_type(idx)->set_rewritable(false);
1787     }
1788     // %%% (We would like to finalize JavaThread::threadObj_offset(),
1789     // but the base pointer type is not distinctive enough to identify
1790     // references into JavaThread.)
1791 
1792     // Check for final fields.
1793     const TypeInstPtr* tinst = flat->isa_instptr();
1794     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
1795       ciField* field;
1796       if (tinst->const_oop() != NULL &&
1797           tinst->klass() == ciEnv::current()->Class_klass() &&
1798           tinst->offset() >= (tinst->klass()->as_instance_klass()->size_helper() * wordSize)) {
1799         // static field
1800         ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
1801         field = k->get_field_by_offset(tinst->offset(), true);
1802       } else {
1803         ciInstanceKlass *k = tinst->klass()->as_instance_klass();
1804         field = k->get_field_by_offset(tinst->offset(), false);
1805       }
1806       assert(field == NULL ||
1807              original_field == NULL ||
1808              (field->holder() == original_field->holder() &&
1809               field->offset() == original_field->offset() &&
1810               field->is_static() == original_field->is_static()), "wrong field?");
1811       // Set field() and is_rewritable() attributes.
1812       if (field != NULL)  alias_type(idx)->set_field(field);
1813     }
1814   }
1815 
1816   // Fill the cache for next time.
1817   ace->_adr_type = adr_type;
1818   ace->_index    = idx;
1819   assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
1820 
1821   // Might as well try to fill the cache for the flattened version, too.
1822   AliasCacheEntry* face = probe_alias_cache(flat);
1823   if (face->_adr_type == NULL) {
1824     face->_adr_type = flat;
1825     face->_index    = idx;
1826     assert(alias_type(flat) == alias_type(idx), "flat type must work too");
1827   }
1828 
1829   return alias_type(idx);
1830 }
1831 
1832 
1833 Compile::AliasType* Compile::alias_type(ciField* field) {
1834   const TypeOopPtr* t;
1835   if (field->is_static())
1836     t = TypeInstPtr::make(field->holder()->java_mirror());
1837   else
1838     t = TypeOopPtr::make_from_klass_raw(field->holder());
1839   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);
1840   assert((field->is_final() || field->is_stable()) == !atp->is_rewritable(), "must get the rewritable bits correct");
1841   return atp;
1842 }
1843 
1844 
1845 //------------------------------have_alias_type--------------------------------
1846 bool Compile::have_alias_type(const TypePtr* adr_type) {
1847   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1848   if (ace->_adr_type == adr_type) {
1849     return true;
1850   }
1851 
1852   // Handle special cases.
1853   if (adr_type == NULL)             return true;
1854   if (adr_type == TypePtr::BOTTOM)  return true;
1855 
1856   return find_alias_type(adr_type, true, NULL) != NULL;
1857 }
1858 
1859 //-----------------------------must_alias--------------------------------------
1860 // True if all values of the given address type are in the given alias category.
1861 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
1862   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1863   if (adr_type == NULL)                 return true;  // NULL serves as TypePtr::TOP
1864   if (alias_idx == AliasIdxTop)         return false; // the empty category
1865   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
1866 
1867   // the only remaining possible overlap is identity
1868   int adr_idx = get_alias_index(adr_type);
1869   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1870   assert(adr_idx == alias_idx ||
1871          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
1872           && adr_type                       != TypeOopPtr::BOTTOM),
1873          "should not be testing for overlap with an unsafe pointer");
1874   return adr_idx == alias_idx;
1875 }
1876 
1877 //------------------------------can_alias--------------------------------------
1878 // True if any values of the given address type are in the given alias category.
1879 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
1880   if (alias_idx == AliasIdxTop)         return false; // the empty category
1881   if (adr_type == NULL)                 return false; // NULL serves as TypePtr::TOP
1882   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1883   if (adr_type->base() == Type::AnyPtr) return true;  // TypePtr::BOTTOM or its twins
1884 
1885   // the only remaining possible overlap is identity
1886   int adr_idx = get_alias_index(adr_type);
1887   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1888   return adr_idx == alias_idx;
1889 }
1890 
1891 
1892 
1893 //---------------------------pop_warm_call-------------------------------------
1894 WarmCallInfo* Compile::pop_warm_call() {
1895   WarmCallInfo* wci = _warm_calls;
1896   if (wci != NULL)  _warm_calls = wci->remove_from(wci);
1897   return wci;
1898 }
1899 
1900 //----------------------------Inline_Warm--------------------------------------
1901 int Compile::Inline_Warm() {
1902   // If there is room, try to inline some more warm call sites.
1903   // %%% Do a graph index compaction pass when we think we're out of space?
1904   if (!InlineWarmCalls)  return 0;
1905 
1906   int calls_made_hot = 0;
1907   int room_to_grow   = NodeCountInliningCutoff - unique();
1908   int amount_to_grow = MIN2(room_to_grow, (int)NodeCountInliningStep);
1909   int amount_grown   = 0;
1910   WarmCallInfo* call;
1911   while (amount_to_grow > 0 && (call = pop_warm_call()) != NULL) {
1912     int est_size = (int)call->size();
1913     if (est_size > (room_to_grow - amount_grown)) {
1914       // This one won't fit anyway.  Get rid of it.
1915       call->make_cold();
1916       continue;
1917     }
1918     call->make_hot();
1919     calls_made_hot++;
1920     amount_grown   += est_size;
1921     amount_to_grow -= est_size;
1922   }
1923 
1924   if (calls_made_hot > 0)  set_major_progress();
1925   return calls_made_hot;
1926 }
1927 
1928 
1929 //----------------------------Finish_Warm--------------------------------------
1930 void Compile::Finish_Warm() {
1931   if (!InlineWarmCalls)  return;
1932   if (failing())  return;
1933   if (warm_calls() == NULL)  return;
1934 
1935   // Clean up loose ends, if we are out of space for inlining.
1936   WarmCallInfo* call;
1937   while ((call = pop_warm_call()) != NULL) {
1938     call->make_cold();
1939   }
1940 }
1941 
1942 //---------------------cleanup_loop_predicates-----------------------
1943 // Remove the opaque nodes that protect the predicates so that all unused
1944 // checks and uncommon_traps will be eliminated from the ideal graph
1945 void Compile::cleanup_loop_predicates(PhaseIterGVN &igvn) {
1946   if (predicate_count()==0) return;
1947   for (int i = predicate_count(); i > 0; i--) {
1948     Node * n = predicate_opaque1_node(i-1);
1949     assert(n->Opcode() == Op_Opaque1, "must be");
1950     igvn.replace_node(n, n->in(1));
1951   }
1952   assert(predicate_count()==0, "should be clean!");
1953 }
1954 
1955 void Compile::add_range_check_cast(Node* n) {
1956   assert(n->isa_CastII()->has_range_check(), "CastII should have range check dependency");
1957   assert(!_range_check_casts->contains(n), "duplicate entry in range check casts");
1958   _range_check_casts->append(n);
1959 }
1960 
1961 // Remove all range check dependent CastIINodes.
1962 void Compile::remove_range_check_casts(PhaseIterGVN &igvn) {
1963   for (int i = range_check_cast_count(); i > 0; i--) {
1964     Node* cast = range_check_cast_node(i-1);
1965     assert(cast->isa_CastII()->has_range_check(), "CastII should have range check dependency");
1966     igvn.replace_node(cast, cast->in(1));
1967   }
1968   assert(range_check_cast_count() == 0, "should be empty");
1969 }
1970 
1971 void Compile::add_opaque4_node(Node* n) {
1972   assert(n->Opcode() == Op_Opaque4, "Opaque4 only");
1973   assert(!_opaque4_nodes->contains(n), "duplicate entry in Opaque4 list");
1974   _opaque4_nodes->append(n);
1975 }
1976 
1977 // Remove all Opaque4 nodes.
1978 void Compile::remove_opaque4_nodes(PhaseIterGVN &igvn) {
1979   for (int i = opaque4_count(); i > 0; i--) {
1980     Node* opaq = opaque4_node(i-1);
1981     assert(opaq->Opcode() == Op_Opaque4, "Opaque4 only");
1982     igvn.replace_node(opaq, opaq->in(2));
1983   }
1984   assert(opaque4_count() == 0, "should be empty");
1985 }
1986 
1987 // StringOpts and late inlining of string methods
1988 void Compile::inline_string_calls(bool parse_time) {
1989   {
1990     // remove useless nodes to make the usage analysis simpler
1991     ResourceMark rm;
1992     PhaseRemoveUseless pru(initial_gvn(), for_igvn());
1993   }
1994 
1995   {
1996     ResourceMark rm;
1997     print_method(PHASE_BEFORE_STRINGOPTS, 3);
1998     PhaseStringOpts pso(initial_gvn(), for_igvn());
1999     print_method(PHASE_AFTER_STRINGOPTS, 3);
2000   }
2001 
2002   // now inline anything that we skipped the first time around
2003   if (!parse_time) {
2004     _late_inlines_pos = _late_inlines.length();
2005   }
2006 
2007   while (_string_late_inlines.length() > 0) {
2008     CallGenerator* cg = _string_late_inlines.pop();
2009     cg->do_late_inline();
2010     if (failing())  return;
2011   }
2012   _string_late_inlines.trunc_to(0);
2013 }
2014 
2015 // Late inlining of boxing methods
2016 void Compile::inline_boxing_calls(PhaseIterGVN& igvn) {
2017   if (_boxing_late_inlines.length() > 0) {
2018     assert(has_boxed_value(), "inconsistent");
2019 
2020     PhaseGVN* gvn = initial_gvn();
2021     set_inlining_incrementally(true);
2022 
2023     assert( igvn._worklist.size() == 0, "should be done with igvn" );
2024     for_igvn()->clear();
2025     gvn->replace_with(&igvn);
2026 
2027     _late_inlines_pos = _late_inlines.length();
2028 
2029     while (_boxing_late_inlines.length() > 0) {
2030       CallGenerator* cg = _boxing_late_inlines.pop();
2031       cg->do_late_inline();
2032       if (failing())  return;
2033     }
2034     _boxing_late_inlines.trunc_to(0);
2035 
2036     {
2037       ResourceMark rm;
2038       PhaseRemoveUseless pru(gvn, for_igvn());
2039     }
2040 
2041     igvn = PhaseIterGVN(gvn);
2042     igvn.optimize();
2043 
2044     set_inlining_progress(false);
2045     set_inlining_incrementally(false);
2046   }
2047 }
2048 
2049 void Compile::inline_incrementally_one(PhaseIterGVN& igvn) {
2050   assert(IncrementalInline, "incremental inlining should be on");
2051   PhaseGVN* gvn = initial_gvn();
2052 
2053   set_inlining_progress(false);
2054   for_igvn()->clear();
2055   gvn->replace_with(&igvn);
2056 
2057   {
2058     TracePhase tp("incrementalInline_inline", &timers[_t_incrInline_inline]);
2059     int i = 0;
2060     for (; i <_late_inlines.length() && !inlining_progress(); i++) {
2061       CallGenerator* cg = _late_inlines.at(i);
2062       _late_inlines_pos = i+1;
2063       cg->do_late_inline();
2064       if (failing())  return;
2065     }
2066     int j = 0;
2067     for (; i < _late_inlines.length(); i++, j++) {
2068       _late_inlines.at_put(j, _late_inlines.at(i));
2069     }
2070     _late_inlines.trunc_to(j);
2071   }
2072 
2073   {
2074     TracePhase tp("incrementalInline_pru", &timers[_t_incrInline_pru]);
2075     ResourceMark rm;
2076     PhaseRemoveUseless pru(gvn, for_igvn());
2077   }
2078 
2079   {
2080     TracePhase tp("incrementalInline_igvn", &timers[_t_incrInline_igvn]);
2081     igvn = PhaseIterGVN(gvn);
2082   }
2083 }
2084 
2085 // Perform incremental inlining until bound on number of live nodes is reached
2086 void Compile::inline_incrementally(PhaseIterGVN& igvn) {
2087   TracePhase tp("incrementalInline", &timers[_t_incrInline]);
2088 
2089   PhaseGVN* gvn = initial_gvn();
2090 
2091   set_inlining_incrementally(true);
2092   set_inlining_progress(true);
2093   uint low_live_nodes = 0;
2094 
2095   while(inlining_progress() && _late_inlines.length() > 0) {
2096 
2097     if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2098       if (low_live_nodes < (uint)LiveNodeCountInliningCutoff * 8 / 10) {
2099         TracePhase tp("incrementalInline_ideal", &timers[_t_incrInline_ideal]);
2100         // PhaseIdealLoop is expensive so we only try it once we are
2101         // out of live nodes and we only try it again if the previous
2102         // helped got the number of nodes down significantly
2103         PhaseIdealLoop ideal_loop( igvn, false, true );
2104         if (failing())  return;
2105         low_live_nodes = live_nodes();
2106         _major_progress = true;
2107       }
2108 
2109       if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2110         break;
2111       }
2112     }
2113 
2114     inline_incrementally_one(igvn);
2115 
2116     if (failing())  return;
2117 
2118     {
2119       TracePhase tp("incrementalInline_igvn", &timers[_t_incrInline_igvn]);
2120       igvn.optimize();
2121     }
2122 
2123     if (failing())  return;
2124   }
2125 
2126   assert( igvn._worklist.size() == 0, "should be done with igvn" );
2127 
2128   if (_string_late_inlines.length() > 0) {
2129     assert(has_stringbuilder(), "inconsistent");
2130     for_igvn()->clear();
2131     initial_gvn()->replace_with(&igvn);
2132 
2133     inline_string_calls(false);
2134 
2135     if (failing())  return;
2136 
2137     {
2138       TracePhase tp("incrementalInline_pru", &timers[_t_incrInline_pru]);
2139       ResourceMark rm;
2140       PhaseRemoveUseless pru(initial_gvn(), for_igvn());
2141     }
2142 
2143     {
2144       TracePhase tp("incrementalInline_igvn", &timers[_t_incrInline_igvn]);
2145       igvn = PhaseIterGVN(gvn);
2146       igvn.optimize();
2147     }
2148   }
2149 
2150   set_inlining_incrementally(false);
2151 }
2152 
2153 
2154 //------------------------------Optimize---------------------------------------
2155 // Given a graph, optimize it.
2156 void Compile::Optimize() {
2157   TracePhase tp("optimizer", &timers[_t_optimizer]);
2158 
2159 #ifndef PRODUCT
2160   if (_directive->BreakAtCompileOption) {
2161     BREAKPOINT;
2162   }
2163 
2164 #endif
2165 
2166   ResourceMark rm;
2167   int          loop_opts_cnt;
2168 
2169   print_inlining_reinit();
2170 
2171   NOT_PRODUCT( verify_graph_edges(); )
2172 
2173   print_method(PHASE_AFTER_PARSING);
2174 
2175  {
2176   // Iterative Global Value Numbering, including ideal transforms
2177   // Initialize IterGVN with types and values from parse-time GVN
2178   PhaseIterGVN igvn(initial_gvn());
2179 #ifdef ASSERT
2180   _modified_nodes = new (comp_arena()) Unique_Node_List(comp_arena());
2181 #endif
2182   {
2183     TracePhase tp("iterGVN", &timers[_t_iterGVN]);
2184     igvn.optimize();
2185   }
2186 
2187   print_method(PHASE_ITER_GVN1, 2);
2188 
2189   if (failing())  return;
2190 
2191   inline_incrementally(igvn);
2192 
2193   print_method(PHASE_INCREMENTAL_INLINE, 2);
2194 
2195   if (failing())  return;
2196 
2197   if (eliminate_boxing()) {
2198     // Inline valueOf() methods now.
2199     inline_boxing_calls(igvn);
2200 
2201     if (AlwaysIncrementalInline) {
2202       inline_incrementally(igvn);
2203     }
2204 
2205     print_method(PHASE_INCREMENTAL_BOXING_INLINE, 2);
2206 
2207     if (failing())  return;
2208   }
2209 
2210   // Remove the speculative part of types and clean up the graph from
2211   // the extra CastPP nodes whose only purpose is to carry them. Do
2212   // that early so that optimizations are not disrupted by the extra
2213   // CastPP nodes.
2214   remove_speculative_types(igvn);
2215 
2216   // No more new expensive nodes will be added to the list from here
2217   // so keep only the actual candidates for optimizations.
2218   cleanup_expensive_nodes(igvn);
2219 
2220   if (!failing() && RenumberLiveNodes && live_nodes() + NodeLimitFudgeFactor < unique()) {
2221     Compile::TracePhase tp("", &timers[_t_renumberLive]);
2222     initial_gvn()->replace_with(&igvn);
2223     for_igvn()->clear();
2224     Unique_Node_List new_worklist(C->comp_arena());
2225     {
2226       ResourceMark rm;
2227       PhaseRenumberLive prl = PhaseRenumberLive(initial_gvn(), for_igvn(), &new_worklist);
2228     }
2229     set_for_igvn(&new_worklist);
2230     igvn = PhaseIterGVN(initial_gvn());
2231     igvn.optimize();
2232   }
2233 
2234   // Perform escape analysis
2235   if (_do_escape_analysis && ConnectionGraph::has_candidates(this)) {
2236     if (has_loops()) {
2237       // Cleanup graph (remove dead nodes).
2238       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2239       PhaseIdealLoop ideal_loop( igvn, false, true );
2240       if (major_progress()) print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
2241       if (failing())  return;
2242     }
2243     ConnectionGraph::do_analysis(this, &igvn);
2244 
2245     if (failing())  return;
2246 
2247     // Optimize out fields loads from scalar replaceable allocations.
2248     igvn.optimize();
2249     print_method(PHASE_ITER_GVN_AFTER_EA, 2);
2250 
2251     if (failing())  return;
2252 
2253     if (congraph() != NULL && macro_count() > 0) {
2254       TracePhase tp("macroEliminate", &timers[_t_macroEliminate]);
2255       PhaseMacroExpand mexp(igvn);
2256       mexp.eliminate_macro_nodes();
2257       igvn.set_delay_transform(false);
2258 
2259       igvn.optimize();
2260       print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
2261 
2262       if (failing())  return;
2263     }
2264   }
2265 
2266   // Loop transforms on the ideal graph.  Range Check Elimination,
2267   // peeling, unrolling, etc.
2268 
2269   // Set loop opts counter
2270   loop_opts_cnt = num_loop_opts();
2271   if((loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
2272     {
2273       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2274       PhaseIdealLoop ideal_loop( igvn, true );
2275       loop_opts_cnt--;
2276       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP1, 2);
2277       if (failing())  return;
2278     }
2279     // Loop opts pass if partial peeling occurred in previous pass
2280     if(PartialPeelLoop && major_progress() && (loop_opts_cnt > 0)) {
2281       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2282       PhaseIdealLoop ideal_loop( igvn, false );
2283       loop_opts_cnt--;
2284       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP2, 2);
2285       if (failing())  return;
2286     }
2287     // Loop opts pass for loop-unrolling before CCP
2288     if(major_progress() && (loop_opts_cnt > 0)) {
2289       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2290       PhaseIdealLoop ideal_loop( igvn, false );
2291       loop_opts_cnt--;
2292       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP3, 2);
2293     }
2294     if (!failing()) {
2295       // Verify that last round of loop opts produced a valid graph
2296       TracePhase tp("idealLoopVerify", &timers[_t_idealLoopVerify]);
2297       PhaseIdealLoop::verify(igvn);
2298     }
2299   }
2300   if (failing())  return;
2301 
2302   // Conditional Constant Propagation;
2303   PhaseCCP ccp( &igvn );
2304   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
2305   {
2306     TracePhase tp("ccp", &timers[_t_ccp]);
2307     ccp.do_transform();
2308   }
2309   print_method(PHASE_CPP1, 2);
2310 
2311   assert( true, "Break here to ccp.dump_old2new_map()");
2312 
2313   // Iterative Global Value Numbering, including ideal transforms
2314   {
2315     TracePhase tp("iterGVN2", &timers[_t_iterGVN2]);
2316     igvn = ccp;
2317     igvn.optimize();
2318   }
2319 
2320   print_method(PHASE_ITER_GVN2, 2);
2321 
2322   if (failing())  return;
2323 
2324   // Loop transforms on the ideal graph.  Range Check Elimination,
2325   // peeling, unrolling, etc.
2326   if(loop_opts_cnt > 0) {
2327     debug_only( int cnt = 0; );
2328     while(major_progress() && (loop_opts_cnt > 0)) {
2329       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2330       assert( cnt++ < 40, "infinite cycle in loop optimization" );
2331       PhaseIdealLoop ideal_loop( igvn, true);
2332       loop_opts_cnt--;
2333       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
2334       if (failing())  return;
2335     }
2336   }
2337   // Ensure that major progress is now clear
2338   C->clear_major_progress();
2339 
2340   {
2341     // Verify that all previous optimizations produced a valid graph
2342     // at least to this point, even if no loop optimizations were done.
2343     TracePhase tp("idealLoopVerify", &timers[_t_idealLoopVerify]);
2344     PhaseIdealLoop::verify(igvn);
2345   }
2346 
2347   if (range_check_cast_count() > 0) {
2348     // No more loop optimizations. Remove all range check dependent CastIINodes.
2349     C->remove_range_check_casts(igvn);
2350     igvn.optimize();
2351   }
2352 
2353   {
2354     TracePhase tp("macroExpand", &timers[_t_macroExpand]);
2355     PhaseMacroExpand  mex(igvn);
2356     if (mex.expand_macro_nodes()) {
2357       assert(failing(), "must bail out w/ explicit message");
2358       return;
2359     }
2360   }
2361 
2362   if (opaque4_count() > 0) {
2363     C->remove_opaque4_nodes(igvn);
2364     igvn.optimize();
2365   }
2366 
2367   DEBUG_ONLY( _modified_nodes = NULL; )
2368  } // (End scope of igvn; run destructor if necessary for asserts.)
2369 
2370  process_print_inlining();
2371  // A method with only infinite loops has no edges entering loops from root
2372  {
2373    TracePhase tp("graphReshape", &timers[_t_graphReshaping]);
2374    if (final_graph_reshaping()) {
2375      assert(failing(), "must bail out w/ explicit message");
2376      return;
2377    }
2378  }
2379 
2380  print_method(PHASE_OPTIMIZE_FINISHED, 2);
2381 }
2382 
2383 
2384 //------------------------------Code_Gen---------------------------------------
2385 // Given a graph, generate code for it
2386 void Compile::Code_Gen() {
2387   if (failing()) {
2388     return;
2389   }
2390 
2391   // Perform instruction selection.  You might think we could reclaim Matcher
2392   // memory PDQ, but actually the Matcher is used in generating spill code.
2393   // Internals of the Matcher (including some VectorSets) must remain live
2394   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
2395   // set a bit in reclaimed memory.
2396 
2397   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2398   // nodes.  Mapping is only valid at the root of each matched subtree.
2399   NOT_PRODUCT( verify_graph_edges(); )
2400 
2401   Matcher matcher;
2402   _matcher = &matcher;
2403   {
2404     TracePhase tp("matcher", &timers[_t_matcher]);
2405     matcher.match();
2406   }
2407   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2408   // nodes.  Mapping is only valid at the root of each matched subtree.
2409   NOT_PRODUCT( verify_graph_edges(); )
2410 
2411   // If you have too many nodes, or if matching has failed, bail out
2412   check_node_count(0, "out of nodes matching instructions");
2413   if (failing()) {
2414     return;
2415   }
2416 
2417   // Build a proper-looking CFG
2418   PhaseCFG cfg(node_arena(), root(), matcher);
2419   _cfg = &cfg;
2420   {
2421     TracePhase tp("scheduler", &timers[_t_scheduler]);
2422     bool success = cfg.do_global_code_motion();
2423     if (!success) {
2424       return;
2425     }
2426 
2427     print_method(PHASE_GLOBAL_CODE_MOTION, 2);
2428     NOT_PRODUCT( verify_graph_edges(); )
2429     debug_only( cfg.verify(); )
2430   }
2431 
2432   PhaseChaitin regalloc(unique(), cfg, matcher, false);
2433   _regalloc = &regalloc;
2434   {
2435     TracePhase tp("regalloc", &timers[_t_registerAllocation]);
2436     // Perform register allocation.  After Chaitin, use-def chains are
2437     // no longer accurate (at spill code) and so must be ignored.
2438     // Node->LRG->reg mappings are still accurate.
2439     _regalloc->Register_Allocate();
2440 
2441     // Bail out if the allocator builds too many nodes
2442     if (failing()) {
2443       return;
2444     }
2445   }
2446 
2447   // Prior to register allocation we kept empty basic blocks in case the
2448   // the allocator needed a place to spill.  After register allocation we
2449   // are not adding any new instructions.  If any basic block is empty, we
2450   // can now safely remove it.
2451   {
2452     TracePhase tp("blockOrdering", &timers[_t_blockOrdering]);
2453     cfg.remove_empty_blocks();
2454     if (do_freq_based_layout()) {
2455       PhaseBlockLayout layout(cfg);
2456     } else {
2457       cfg.set_loop_alignment();
2458     }
2459     cfg.fixup_flow();
2460   }
2461 
2462   // Apply peephole optimizations
2463   if( OptoPeephole ) {
2464     TracePhase tp("peephole", &timers[_t_peephole]);
2465     PhasePeephole peep( _regalloc, cfg);
2466     peep.do_transform();
2467   }
2468 
2469   // Do late expand if CPU requires this.
2470   if (Matcher::require_postalloc_expand) {
2471     TracePhase tp("postalloc_expand", &timers[_t_postalloc_expand]);
2472     cfg.postalloc_expand(_regalloc);
2473   }
2474 
2475   // Convert Nodes to instruction bits in a buffer
2476   {
2477     TraceTime tp("output", &timers[_t_output], CITime);
2478     Output();
2479   }
2480 
2481   print_method(PHASE_FINAL_CODE);
2482 
2483   // He's dead, Jim.
2484   _cfg     = (PhaseCFG*)((intptr_t)0xdeadbeef);
2485   _regalloc = (PhaseChaitin*)((intptr_t)0xdeadbeef);
2486 }
2487 
2488 
2489 //------------------------------dump_asm---------------------------------------
2490 // Dump formatted assembly
2491 #ifndef PRODUCT
2492 void Compile::dump_asm(int *pcs, uint pc_limit) {
2493   bool cut_short = false;
2494   tty->print_cr("#");
2495   tty->print("#  ");  _tf->dump();  tty->cr();
2496   tty->print_cr("#");
2497 
2498   // For all blocks
2499   int pc = 0x0;                 // Program counter
2500   char starts_bundle = ' ';
2501   _regalloc->dump_frame();
2502 
2503   Node *n = NULL;
2504   for (uint i = 0; i < _cfg->number_of_blocks(); i++) {
2505     if (VMThread::should_terminate()) {
2506       cut_short = true;
2507       break;
2508     }
2509     Block* block = _cfg->get_block(i);
2510     if (block->is_connector() && !Verbose) {
2511       continue;
2512     }
2513     n = block->head();
2514     if (pcs && n->_idx < pc_limit) {
2515       tty->print("%3.3x   ", pcs[n->_idx]);
2516     } else {
2517       tty->print("      ");
2518     }
2519     block->dump_head(_cfg);
2520     if (block->is_connector()) {
2521       tty->print_cr("        # Empty connector block");
2522     } else if (block->num_preds() == 2 && block->pred(1)->is_CatchProj() && block->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
2523       tty->print_cr("        # Block is sole successor of call");
2524     }
2525 
2526     // For all instructions
2527     Node *delay = NULL;
2528     for (uint j = 0; j < block->number_of_nodes(); j++) {
2529       if (VMThread::should_terminate()) {
2530         cut_short = true;
2531         break;
2532       }
2533       n = block->get_node(j);
2534       if (valid_bundle_info(n)) {
2535         Bundle* bundle = node_bundling(n);
2536         if (bundle->used_in_unconditional_delay()) {
2537           delay = n;
2538           continue;
2539         }
2540         if (bundle->starts_bundle()) {
2541           starts_bundle = '+';
2542         }
2543       }
2544 
2545       if (WizardMode) {
2546         n->dump();
2547       }
2548 
2549       if( !n->is_Region() &&    // Dont print in the Assembly
2550           !n->is_Phi() &&       // a few noisely useless nodes
2551           !n->is_Proj() &&
2552           !n->is_MachTemp() &&
2553           !n->is_SafePointScalarObject() &&
2554           !n->is_Catch() &&     // Would be nice to print exception table targets
2555           !n->is_MergeMem() &&  // Not very interesting
2556           !n->is_top() &&       // Debug info table constants
2557           !(n->is_Con() && !n->is_Mach())// Debug info table constants
2558           ) {
2559         if (pcs && n->_idx < pc_limit)
2560           tty->print("%3.3x", pcs[n->_idx]);
2561         else
2562           tty->print("   ");
2563         tty->print(" %c ", starts_bundle);
2564         starts_bundle = ' ';
2565         tty->print("\t");
2566         n->format(_regalloc, tty);
2567         tty->cr();
2568       }
2569 
2570       // If we have an instruction with a delay slot, and have seen a delay,
2571       // then back up and print it
2572       if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
2573         assert(delay != NULL, "no unconditional delay instruction");
2574         if (WizardMode) delay->dump();
2575 
2576         if (node_bundling(delay)->starts_bundle())
2577           starts_bundle = '+';
2578         if (pcs && n->_idx < pc_limit)
2579           tty->print("%3.3x", pcs[n->_idx]);
2580         else
2581           tty->print("   ");
2582         tty->print(" %c ", starts_bundle);
2583         starts_bundle = ' ';
2584         tty->print("\t");
2585         delay->format(_regalloc, tty);
2586         tty->cr();
2587         delay = NULL;
2588       }
2589 
2590       // Dump the exception table as well
2591       if( n->is_Catch() && (Verbose || WizardMode) ) {
2592         // Print the exception table for this offset
2593         _handler_table.print_subtable_for(pc);
2594       }
2595     }
2596 
2597     if (pcs && n->_idx < pc_limit)
2598       tty->print_cr("%3.3x", pcs[n->_idx]);
2599     else
2600       tty->cr();
2601 
2602     assert(cut_short || delay == NULL, "no unconditional delay branch");
2603 
2604   } // End of per-block dump
2605   tty->cr();
2606 
2607   if (cut_short)  tty->print_cr("*** disassembly is cut short ***");
2608 }
2609 #endif
2610 
2611 //------------------------------Final_Reshape_Counts---------------------------
2612 // This class defines counters to help identify when a method
2613 // may/must be executed using hardware with only 24-bit precision.
2614 struct Final_Reshape_Counts : public StackObj {
2615   int  _call_count;             // count non-inlined 'common' calls
2616   int  _float_count;            // count float ops requiring 24-bit precision
2617   int  _double_count;           // count double ops requiring more precision
2618   int  _java_call_count;        // count non-inlined 'java' calls
2619   int  _inner_loop_count;       // count loops which need alignment
2620   VectorSet _visited;           // Visitation flags
2621   Node_List _tests;             // Set of IfNodes & PCTableNodes
2622 
2623   Final_Reshape_Counts() :
2624     _call_count(0), _float_count(0), _double_count(0),
2625     _java_call_count(0), _inner_loop_count(0),
2626     _visited( Thread::current()->resource_area() ) { }
2627 
2628   void inc_call_count  () { _call_count  ++; }
2629   void inc_float_count () { _float_count ++; }
2630   void inc_double_count() { _double_count++; }
2631   void inc_java_call_count() { _java_call_count++; }
2632   void inc_inner_loop_count() { _inner_loop_count++; }
2633 
2634   int  get_call_count  () const { return _call_count  ; }
2635   int  get_float_count () const { return _float_count ; }
2636   int  get_double_count() const { return _double_count; }
2637   int  get_java_call_count() const { return _java_call_count; }
2638   int  get_inner_loop_count() const { return _inner_loop_count; }
2639 };
2640 
2641 #ifdef ASSERT
2642 static bool oop_offset_is_sane(const TypeInstPtr* tp) {
2643   ciInstanceKlass *k = tp->klass()->as_instance_klass();
2644   // Make sure the offset goes inside the instance layout.
2645   return k->contains_field_offset(tp->offset());
2646   // Note that OffsetBot and OffsetTop are very negative.
2647 }
2648 #endif
2649 
2650 // Eliminate trivially redundant StoreCMs and accumulate their
2651 // precedence edges.
2652 void Compile::eliminate_redundant_card_marks(Node* n) {
2653   assert(n->Opcode() == Op_StoreCM, "expected StoreCM");
2654   if (n->in(MemNode::Address)->outcnt() > 1) {
2655     // There are multiple users of the same address so it might be
2656     // possible to eliminate some of the StoreCMs
2657     Node* mem = n->in(MemNode::Memory);
2658     Node* adr = n->in(MemNode::Address);
2659     Node* val = n->in(MemNode::ValueIn);
2660     Node* prev = n;
2661     bool done = false;
2662     // Walk the chain of StoreCMs eliminating ones that match.  As
2663     // long as it's a chain of single users then the optimization is
2664     // safe.  Eliminating partially redundant StoreCMs would require
2665     // cloning copies down the other paths.
2666     while (mem->Opcode() == Op_StoreCM && mem->outcnt() == 1 && !done) {
2667       if (adr == mem->in(MemNode::Address) &&
2668           val == mem->in(MemNode::ValueIn)) {
2669         // redundant StoreCM
2670         if (mem->req() > MemNode::OopStore) {
2671           // Hasn't been processed by this code yet.
2672           n->add_prec(mem->in(MemNode::OopStore));
2673         } else {
2674           // Already converted to precedence edge
2675           for (uint i = mem->req(); i < mem->len(); i++) {
2676             // Accumulate any precedence edges
2677             if (mem->in(i) != NULL) {
2678               n->add_prec(mem->in(i));
2679             }
2680           }
2681           // Everything above this point has been processed.
2682           done = true;
2683         }
2684         // Eliminate the previous StoreCM
2685         prev->set_req(MemNode::Memory, mem->in(MemNode::Memory));
2686         assert(mem->outcnt() == 0, "should be dead");
2687         mem->disconnect_inputs(NULL, this);
2688       } else {
2689         prev = mem;
2690       }
2691       mem = prev->in(MemNode::Memory);
2692     }
2693   }
2694 }
2695 
2696 //------------------------------final_graph_reshaping_impl----------------------
2697 // Implement items 1-5 from final_graph_reshaping below.
2698 void Compile::final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &frc) {
2699 
2700   if ( n->outcnt() == 0 ) return; // dead node
2701   uint nop = n->Opcode();
2702 
2703   // Check for 2-input instruction with "last use" on right input.
2704   // Swap to left input.  Implements item (2).
2705   if( n->req() == 3 &&          // two-input instruction
2706       n->in(1)->outcnt() > 1 && // left use is NOT a last use
2707       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
2708       n->in(2)->outcnt() == 1 &&// right use IS a last use
2709       !n->in(2)->is_Con() ) {   // right use is not a constant
2710     // Check for commutative opcode
2711     switch( nop ) {
2712     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddL:
2713     case Op_MaxI:  case Op_MinI:
2714     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulL:
2715     case Op_AndL:  case Op_XorL:  case Op_OrL:
2716     case Op_AndI:  case Op_XorI:  case Op_OrI: {
2717       // Move "last use" input to left by swapping inputs
2718       n->swap_edges(1, 2);
2719       break;
2720     }
2721     default:
2722       break;
2723     }
2724   }
2725 
2726 #ifdef ASSERT
2727   if( n->is_Mem() ) {
2728     int alias_idx = get_alias_index(n->as_Mem()->adr_type());
2729     assert( n->in(0) != NULL || alias_idx != Compile::AliasIdxRaw ||
2730             // oop will be recorded in oop map if load crosses safepoint
2731             n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
2732                              LoadNode::is_immutable_value(n->in(MemNode::Address))),
2733             "raw memory operations should have control edge");
2734   }
2735 #endif
2736   // Count FPU ops and common calls, implements item (3)
2737   switch( nop ) {
2738   // Count all float operations that may use FPU
2739   case Op_AddF:
2740   case Op_SubF:
2741   case Op_MulF:
2742   case Op_DivF:
2743   case Op_NegF:
2744   case Op_ModF:
2745   case Op_ConvI2F:
2746   case Op_ConF:
2747   case Op_CmpF:
2748   case Op_CmpF3:
2749   // case Op_ConvL2F: // longs are split into 32-bit halves
2750     frc.inc_float_count();
2751     break;
2752 
2753   case Op_ConvF2D:
2754   case Op_ConvD2F:
2755     frc.inc_float_count();
2756     frc.inc_double_count();
2757     break;
2758 
2759   // Count all double operations that may use FPU
2760   case Op_AddD:
2761   case Op_SubD:
2762   case Op_MulD:
2763   case Op_DivD:
2764   case Op_NegD:
2765   case Op_ModD:
2766   case Op_ConvI2D:
2767   case Op_ConvD2I:
2768   // case Op_ConvL2D: // handled by leaf call
2769   // case Op_ConvD2L: // handled by leaf call
2770   case Op_ConD:
2771   case Op_CmpD:
2772   case Op_CmpD3:
2773     frc.inc_double_count();
2774     break;
2775   case Op_Opaque1:              // Remove Opaque Nodes before matching
2776   case Op_Opaque2:              // Remove Opaque Nodes before matching
2777   case Op_Opaque3:
2778     n->subsume_by(n->in(1), this);
2779     break;
2780   case Op_CallStaticJava:
2781   case Op_CallJava:
2782   case Op_CallDynamicJava:
2783     frc.inc_java_call_count(); // Count java call site;
2784   case Op_CallRuntime:
2785   case Op_CallLeaf:
2786   case Op_CallLeafNoFP: {
2787     assert (n->is_Call(), "");
2788     CallNode *call = n->as_Call();
2789     // Count call sites where the FP mode bit would have to be flipped.
2790     // Do not count uncommon runtime calls:
2791     // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
2792     // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
2793     if (!call->is_CallStaticJava() || !call->as_CallStaticJava()->_name) {
2794       frc.inc_call_count();   // Count the call site
2795     } else {                  // See if uncommon argument is shared
2796       Node *n = call->in(TypeFunc::Parms);
2797       int nop = n->Opcode();
2798       // Clone shared simple arguments to uncommon calls, item (1).
2799       if (n->outcnt() > 1 &&
2800           !n->is_Proj() &&
2801           nop != Op_CreateEx &&
2802           nop != Op_CheckCastPP &&
2803           nop != Op_DecodeN &&
2804           nop != Op_DecodeNKlass &&
2805           !n->is_Mem() &&
2806           !n->is_Phi()) {
2807         Node *x = n->clone();
2808         call->set_req(TypeFunc::Parms, x);
2809       }
2810     }
2811     break;
2812   }
2813 
2814   case Op_StoreD:
2815   case Op_LoadD:
2816   case Op_LoadD_unaligned:
2817     frc.inc_double_count();
2818     goto handle_mem;
2819   case Op_StoreF:
2820   case Op_LoadF:
2821     frc.inc_float_count();
2822     goto handle_mem;
2823 
2824   case Op_StoreCM:
2825     {
2826       // Convert OopStore dependence into precedence edge
2827       Node* prec = n->in(MemNode::OopStore);
2828       n->del_req(MemNode::OopStore);
2829       n->add_prec(prec);
2830       eliminate_redundant_card_marks(n);
2831     }
2832 
2833     // fall through
2834 
2835   case Op_StoreB:
2836   case Op_StoreC:
2837   case Op_StorePConditional:
2838   case Op_StoreI:
2839   case Op_StoreL:
2840   case Op_StoreIConditional:
2841   case Op_StoreLConditional:
2842   case Op_CompareAndSwapB:
2843   case Op_CompareAndSwapS:
2844   case Op_CompareAndSwapI:
2845   case Op_CompareAndSwapL:
2846   case Op_CompareAndSwapP:
2847   case Op_CompareAndSwapN:
2848   case Op_WeakCompareAndSwapB:
2849   case Op_WeakCompareAndSwapS:
2850   case Op_WeakCompareAndSwapI:
2851   case Op_WeakCompareAndSwapL:
2852   case Op_WeakCompareAndSwapP:
2853   case Op_WeakCompareAndSwapN:
2854   case Op_CompareAndExchangeB:
2855   case Op_CompareAndExchangeS:
2856   case Op_CompareAndExchangeI:
2857   case Op_CompareAndExchangeL:
2858   case Op_CompareAndExchangeP:
2859   case Op_CompareAndExchangeN:
2860   case Op_GetAndAddS:
2861   case Op_GetAndAddB:
2862   case Op_GetAndAddI:
2863   case Op_GetAndAddL:
2864   case Op_GetAndSetS:
2865   case Op_GetAndSetB:
2866   case Op_GetAndSetI:
2867   case Op_GetAndSetL:
2868   case Op_GetAndSetP:
2869   case Op_GetAndSetN:
2870   case Op_StoreP:
2871   case Op_StoreN:
2872   case Op_StoreNKlass:
2873   case Op_LoadB:
2874   case Op_LoadUB:
2875   case Op_LoadUS:
2876   case Op_LoadI:
2877   case Op_LoadKlass:
2878   case Op_LoadNKlass:
2879   case Op_LoadL:
2880   case Op_LoadL_unaligned:
2881   case Op_LoadPLocked:
2882   case Op_LoadP:
2883   case Op_LoadN:
2884   case Op_LoadRange:
2885   case Op_LoadS: {
2886   handle_mem:
2887 #ifdef ASSERT
2888     if( VerifyOptoOopOffsets ) {
2889       assert( n->is_Mem(), "" );
2890       MemNode *mem  = (MemNode*)n;
2891       // Check to see if address types have grounded out somehow.
2892       const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
2893       assert( !tp || oop_offset_is_sane(tp), "" );
2894     }
2895 #endif
2896     break;
2897   }
2898 
2899   case Op_AddP: {               // Assert sane base pointers
2900     Node *addp = n->in(AddPNode::Address);
2901     assert( !addp->is_AddP() ||
2902             addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
2903             addp->in(AddPNode::Base) == n->in(AddPNode::Base),
2904             "Base pointers must match (addp %u)", addp->_idx );
2905 #ifdef _LP64
2906     if ((UseCompressedOops || UseCompressedClassPointers) &&
2907         addp->Opcode() == Op_ConP &&
2908         addp == n->in(AddPNode::Base) &&
2909         n->in(AddPNode::Offset)->is_Con()) {
2910       // If the transformation of ConP to ConN+DecodeN is beneficial depends
2911       // on the platform and on the compressed oops mode.
2912       // Use addressing with narrow klass to load with offset on x86.
2913       // Some platforms can use the constant pool to load ConP.
2914       // Do this transformation here since IGVN will convert ConN back to ConP.
2915       const Type* t = addp->bottom_type();
2916       bool is_oop   = t->isa_oopptr() != NULL;
2917       bool is_klass = t->isa_klassptr() != NULL;
2918 
2919       if ((is_oop   && Matcher::const_oop_prefer_decode()  ) ||
2920           (is_klass && Matcher::const_klass_prefer_decode())) {
2921         Node* nn = NULL;
2922 
2923         int op = is_oop ? Op_ConN : Op_ConNKlass;
2924 
2925         // Look for existing ConN node of the same exact type.
2926         Node* r  = root();
2927         uint cnt = r->outcnt();
2928         for (uint i = 0; i < cnt; i++) {
2929           Node* m = r->raw_out(i);
2930           if (m!= NULL && m->Opcode() == op &&
2931               m->bottom_type()->make_ptr() == t) {
2932             nn = m;
2933             break;
2934           }
2935         }
2936         if (nn != NULL) {
2937           // Decode a narrow oop to match address
2938           // [R12 + narrow_oop_reg<<3 + offset]
2939           if (is_oop) {
2940             nn = new DecodeNNode(nn, t);
2941           } else {
2942             nn = new DecodeNKlassNode(nn, t);
2943           }
2944           // Check for succeeding AddP which uses the same Base.
2945           // Otherwise we will run into the assertion above when visiting that guy.
2946           for (uint i = 0; i < n->outcnt(); ++i) {
2947             Node *out_i = n->raw_out(i);
2948             if (out_i && out_i->is_AddP() && out_i->in(AddPNode::Base) == addp) {
2949               out_i->set_req(AddPNode::Base, nn);
2950 #ifdef ASSERT
2951               for (uint j = 0; j < out_i->outcnt(); ++j) {
2952                 Node *out_j = out_i->raw_out(j);
2953                 assert(out_j == NULL || !out_j->is_AddP() || out_j->in(AddPNode::Base) != addp,
2954                        "more than 2 AddP nodes in a chain (out_j %u)", out_j->_idx);
2955               }
2956 #endif
2957             }
2958           }
2959           n->set_req(AddPNode::Base, nn);
2960           n->set_req(AddPNode::Address, nn);
2961           if (addp->outcnt() == 0) {
2962             addp->disconnect_inputs(NULL, this);
2963           }
2964         }
2965       }
2966     }
2967 #endif
2968     // platform dependent reshaping of the address expression
2969     reshape_address(n->as_AddP());
2970     break;
2971   }
2972 
2973   case Op_CastPP: {
2974     // Remove CastPP nodes to gain more freedom during scheduling but
2975     // keep the dependency they encode as control or precedence edges
2976     // (if control is set already) on memory operations. Some CastPP
2977     // nodes don't have a control (don't carry a dependency): skip
2978     // those.
2979     if (n->in(0) != NULL) {
2980       ResourceMark rm;
2981       Unique_Node_List wq;
2982       wq.push(n);
2983       for (uint next = 0; next < wq.size(); ++next) {
2984         Node *m = wq.at(next);
2985         for (DUIterator_Fast imax, i = m->fast_outs(imax); i < imax; i++) {
2986           Node* use = m->fast_out(i);
2987           if (use->is_Mem() || use->is_EncodeNarrowPtr()) {
2988             use->ensure_control_or_add_prec(n->in(0));
2989           } else {
2990             switch(use->Opcode()) {
2991             case Op_AddP:
2992             case Op_DecodeN:
2993             case Op_DecodeNKlass:
2994             case Op_CheckCastPP:
2995             case Op_CastPP:
2996               wq.push(use);
2997               break;
2998             }
2999           }
3000         }
3001       }
3002     }
3003     const bool is_LP64 = LP64_ONLY(true) NOT_LP64(false);
3004     if (is_LP64 && n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
3005       Node* in1 = n->in(1);
3006       const Type* t = n->bottom_type();
3007       Node* new_in1 = in1->clone();
3008       new_in1->as_DecodeN()->set_type(t);
3009 
3010       if (!Matcher::narrow_oop_use_complex_address()) {
3011         //
3012         // x86, ARM and friends can handle 2 adds in addressing mode
3013         // and Matcher can fold a DecodeN node into address by using
3014         // a narrow oop directly and do implicit NULL check in address:
3015         //
3016         // [R12 + narrow_oop_reg<<3 + offset]
3017         // NullCheck narrow_oop_reg
3018         //
3019         // On other platforms (Sparc) we have to keep new DecodeN node and
3020         // use it to do implicit NULL check in address:
3021         //
3022         // decode_not_null narrow_oop_reg, base_reg
3023         // [base_reg + offset]
3024         // NullCheck base_reg
3025         //
3026         // Pin the new DecodeN node to non-null path on these platform (Sparc)
3027         // to keep the information to which NULL check the new DecodeN node
3028         // corresponds to use it as value in implicit_null_check().
3029         //
3030         new_in1->set_req(0, n->in(0));
3031       }
3032 
3033       n->subsume_by(new_in1, this);
3034       if (in1->outcnt() == 0) {
3035         in1->disconnect_inputs(NULL, this);
3036       }
3037     } else {
3038       n->subsume_by(n->in(1), this);
3039       if (n->outcnt() == 0) {
3040         n->disconnect_inputs(NULL, this);
3041       }
3042     }
3043     break;
3044   }
3045 #ifdef _LP64
3046   case Op_CmpP:
3047     // Do this transformation here to preserve CmpPNode::sub() and
3048     // other TypePtr related Ideal optimizations (for example, ptr nullness).
3049     if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
3050       Node* in1 = n->in(1);
3051       Node* in2 = n->in(2);
3052       if (!in1->is_DecodeNarrowPtr()) {
3053         in2 = in1;
3054         in1 = n->in(2);
3055       }
3056       assert(in1->is_DecodeNarrowPtr(), "sanity");
3057 
3058       Node* new_in2 = NULL;
3059       if (in2->is_DecodeNarrowPtr()) {
3060         assert(in2->Opcode() == in1->Opcode(), "must be same node type");
3061         new_in2 = in2->in(1);
3062       } else if (in2->Opcode() == Op_ConP) {
3063         const Type* t = in2->bottom_type();
3064         if (t == TypePtr::NULL_PTR) {
3065           assert(in1->is_DecodeN(), "compare klass to null?");
3066           // Don't convert CmpP null check into CmpN if compressed
3067           // oops implicit null check is not generated.
3068           // This will allow to generate normal oop implicit null check.
3069           if (Matcher::gen_narrow_oop_implicit_null_checks())
3070             new_in2 = ConNode::make(TypeNarrowOop::NULL_PTR);
3071           //
3072           // This transformation together with CastPP transformation above
3073           // will generated code for implicit NULL checks for compressed oops.
3074           //
3075           // The original code after Optimize()
3076           //
3077           //    LoadN memory, narrow_oop_reg
3078           //    decode narrow_oop_reg, base_reg
3079           //    CmpP base_reg, NULL
3080           //    CastPP base_reg // NotNull
3081           //    Load [base_reg + offset], val_reg
3082           //
3083           // after these transformations will be
3084           //
3085           //    LoadN memory, narrow_oop_reg
3086           //    CmpN narrow_oop_reg, NULL
3087           //    decode_not_null narrow_oop_reg, base_reg
3088           //    Load [base_reg + offset], val_reg
3089           //
3090           // and the uncommon path (== NULL) will use narrow_oop_reg directly
3091           // since narrow oops can be used in debug info now (see the code in
3092           // final_graph_reshaping_walk()).
3093           //
3094           // At the end the code will be matched to
3095           // on x86:
3096           //
3097           //    Load_narrow_oop memory, narrow_oop_reg
3098           //    Load [R12 + narrow_oop_reg<<3 + offset], val_reg
3099           //    NullCheck narrow_oop_reg
3100           //
3101           // and on sparc:
3102           //
3103           //    Load_narrow_oop memory, narrow_oop_reg
3104           //    decode_not_null narrow_oop_reg, base_reg
3105           //    Load [base_reg + offset], val_reg
3106           //    NullCheck base_reg
3107           //
3108         } else if (t->isa_oopptr()) {
3109           new_in2 = ConNode::make(t->make_narrowoop());
3110         } else if (t->isa_klassptr()) {
3111           new_in2 = ConNode::make(t->make_narrowklass());
3112         }
3113       }
3114       if (new_in2 != NULL) {
3115         Node* cmpN = new CmpNNode(in1->in(1), new_in2);
3116         n->subsume_by(cmpN, this);
3117         if (in1->outcnt() == 0) {
3118           in1->disconnect_inputs(NULL, this);
3119         }
3120         if (in2->outcnt() == 0) {
3121           in2->disconnect_inputs(NULL, this);
3122         }
3123       }
3124     }
3125     break;
3126 
3127   case Op_DecodeN:
3128   case Op_DecodeNKlass:
3129     assert(!n->in(1)->is_EncodeNarrowPtr(), "should be optimized out");
3130     // DecodeN could be pinned when it can't be fold into
3131     // an address expression, see the code for Op_CastPP above.
3132     assert(n->in(0) == NULL || (UseCompressedOops && !Matcher::narrow_oop_use_complex_address()), "no control");
3133     break;
3134 
3135   case Op_EncodeP:
3136   case Op_EncodePKlass: {
3137     Node* in1 = n->in(1);
3138     if (in1->is_DecodeNarrowPtr()) {
3139       n->subsume_by(in1->in(1), this);
3140     } else if (in1->Opcode() == Op_ConP) {
3141       const Type* t = in1->bottom_type();
3142       if (t == TypePtr::NULL_PTR) {
3143         assert(t->isa_oopptr(), "null klass?");
3144         n->subsume_by(ConNode::make(TypeNarrowOop::NULL_PTR), this);
3145       } else if (t->isa_oopptr()) {
3146         n->subsume_by(ConNode::make(t->make_narrowoop()), this);
3147       } else if (t->isa_klassptr()) {
3148         n->subsume_by(ConNode::make(t->make_narrowklass()), this);
3149       }
3150     }
3151     if (in1->outcnt() == 0) {
3152       in1->disconnect_inputs(NULL, this);
3153     }
3154     break;
3155   }
3156 
3157   case Op_Proj: {
3158     if (OptimizeStringConcat) {
3159       ProjNode* p = n->as_Proj();
3160       if (p->_is_io_use) {
3161         // Separate projections were used for the exception path which
3162         // are normally removed by a late inline.  If it wasn't inlined
3163         // then they will hang around and should just be replaced with
3164         // the original one.
3165         Node* proj = NULL;
3166         // Replace with just one
3167         for (SimpleDUIterator i(p->in(0)); i.has_next(); i.next()) {
3168           Node *use = i.get();
3169           if (use->is_Proj() && p != use && use->as_Proj()->_con == p->_con) {
3170             proj = use;
3171             break;
3172           }
3173         }
3174         assert(proj != NULL, "must be found");
3175         p->subsume_by(proj, this);
3176       }
3177     }
3178     break;
3179   }
3180 
3181   case Op_Phi:
3182     if (n->as_Phi()->bottom_type()->isa_narrowoop() || n->as_Phi()->bottom_type()->isa_narrowklass()) {
3183       // The EncodeP optimization may create Phi with the same edges
3184       // for all paths. It is not handled well by Register Allocator.
3185       Node* unique_in = n->in(1);
3186       assert(unique_in != NULL, "");
3187       uint cnt = n->req();
3188       for (uint i = 2; i < cnt; i++) {
3189         Node* m = n->in(i);
3190         assert(m != NULL, "");
3191         if (unique_in != m)
3192           unique_in = NULL;
3193       }
3194       if (unique_in != NULL) {
3195         n->subsume_by(unique_in, this);
3196       }
3197     }
3198     break;
3199 
3200 #endif
3201 
3202 #ifdef ASSERT
3203   case Op_CastII:
3204     // Verify that all range check dependent CastII nodes were removed.
3205     if (n->isa_CastII()->has_range_check()) {
3206       n->dump(3);
3207       assert(false, "Range check dependent CastII node was not removed");
3208     }
3209     break;
3210 #endif
3211 
3212   case Op_ModI:
3213     if (UseDivMod) {
3214       // Check if a%b and a/b both exist
3215       Node* d = n->find_similar(Op_DivI);
3216       if (d) {
3217         // Replace them with a fused divmod if supported
3218         if (Matcher::has_match_rule(Op_DivModI)) {
3219           DivModINode* divmod = DivModINode::make(n);
3220           d->subsume_by(divmod->div_proj(), this);
3221           n->subsume_by(divmod->mod_proj(), this);
3222         } else {
3223           // replace a%b with a-((a/b)*b)
3224           Node* mult = new MulINode(d, d->in(2));
3225           Node* sub  = new SubINode(d->in(1), mult);
3226           n->subsume_by(sub, this);
3227         }
3228       }
3229     }
3230     break;
3231 
3232   case Op_ModL:
3233     if (UseDivMod) {
3234       // Check if a%b and a/b both exist
3235       Node* d = n->find_similar(Op_DivL);
3236       if (d) {
3237         // Replace them with a fused divmod if supported
3238         if (Matcher::has_match_rule(Op_DivModL)) {
3239           DivModLNode* divmod = DivModLNode::make(n);
3240           d->subsume_by(divmod->div_proj(), this);
3241           n->subsume_by(divmod->mod_proj(), this);
3242         } else {
3243           // replace a%b with a-((a/b)*b)
3244           Node* mult = new MulLNode(d, d->in(2));
3245           Node* sub  = new SubLNode(d->in(1), mult);
3246           n->subsume_by(sub, this);
3247         }
3248       }
3249     }
3250     break;
3251 
3252   case Op_LoadVector:
3253   case Op_StoreVector:
3254     break;
3255 
3256   case Op_AddReductionVI:
3257   case Op_AddReductionVL:
3258   case Op_AddReductionVF:
3259   case Op_AddReductionVD:
3260   case Op_MulReductionVI:
3261   case Op_MulReductionVL:
3262   case Op_MulReductionVF:
3263   case Op_MulReductionVD:
3264     break;
3265 
3266   case Op_PackB:
3267   case Op_PackS:
3268   case Op_PackI:
3269   case Op_PackF:
3270   case Op_PackL:
3271   case Op_PackD:
3272     if (n->req()-1 > 2) {
3273       // Replace many operand PackNodes with a binary tree for matching
3274       PackNode* p = (PackNode*) n;
3275       Node* btp = p->binary_tree_pack(1, n->req());
3276       n->subsume_by(btp, this);
3277     }
3278     break;
3279   case Op_Loop:
3280   case Op_CountedLoop:
3281   case Op_OuterStripMinedLoop:
3282     if (n->as_Loop()->is_inner_loop()) {
3283       frc.inc_inner_loop_count();
3284     }
3285     n->as_Loop()->verify_strip_mined(0);
3286     break;
3287   case Op_LShiftI:
3288   case Op_RShiftI:
3289   case Op_URShiftI:
3290   case Op_LShiftL:
3291   case Op_RShiftL:
3292   case Op_URShiftL:
3293     if (Matcher::need_masked_shift_count) {
3294       // The cpu's shift instructions don't restrict the count to the
3295       // lower 5/6 bits. We need to do the masking ourselves.
3296       Node* in2 = n->in(2);
3297       juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
3298       const TypeInt* t = in2->find_int_type();
3299       if (t != NULL && t->is_con()) {
3300         juint shift = t->get_con();
3301         if (shift > mask) { // Unsigned cmp
3302           n->set_req(2, ConNode::make(TypeInt::make(shift & mask)));
3303         }
3304       } else {
3305         if (t == NULL || t->_lo < 0 || t->_hi > (int)mask) {
3306           Node* shift = new AndINode(in2, ConNode::make(TypeInt::make(mask)));
3307           n->set_req(2, shift);
3308         }
3309       }
3310       if (in2->outcnt() == 0) { // Remove dead node
3311         in2->disconnect_inputs(NULL, this);
3312       }
3313     }
3314     break;
3315   case Op_MemBarStoreStore:
3316   case Op_MemBarRelease:
3317     // Break the link with AllocateNode: it is no longer useful and
3318     // confuses register allocation.
3319     if (n->req() > MemBarNode::Precedent) {
3320       n->set_req(MemBarNode::Precedent, top());
3321     }
3322     break;
3323   case Op_RangeCheck: {
3324     RangeCheckNode* rc = n->as_RangeCheck();
3325     Node* iff = new IfNode(rc->in(0), rc->in(1), rc->_prob, rc->_fcnt);
3326     n->subsume_by(iff, this);
3327     frc._tests.push(iff);
3328     break;
3329   }
3330   case Op_ConvI2L: {
3331     if (!Matcher::convi2l_type_required) {
3332       // Code generation on some platforms doesn't need accurate
3333       // ConvI2L types. Widening the type can help remove redundant
3334       // address computations.
3335       n->as_Type()->set_type(TypeLong::INT);
3336       ResourceMark rm;
3337       Node_List wq;
3338       wq.push(n);
3339       for (uint next = 0; next < wq.size(); next++) {
3340         Node *m = wq.at(next);
3341 
3342         for(;;) {
3343           // Loop over all nodes with identical inputs edges as m
3344           Node* k = m->find_similar(m->Opcode());
3345           if (k == NULL) {
3346             break;
3347           }
3348           // Push their uses so we get a chance to remove node made
3349           // redundant
3350           for (DUIterator_Fast imax, i = k->fast_outs(imax); i < imax; i++) {
3351             Node* u = k->fast_out(i);
3352             assert(!wq.contains(u), "shouldn't process one node several times");
3353             if (u->Opcode() == Op_LShiftL ||
3354                 u->Opcode() == Op_AddL ||
3355                 u->Opcode() == Op_SubL ||
3356                 u->Opcode() == Op_AddP) {
3357               wq.push(u);
3358             }
3359           }
3360           // Replace all nodes with identical edges as m with m
3361           k->subsume_by(m, this);
3362         }
3363       }
3364     }
3365     break;
3366   }
3367   case Op_CmpUL: {
3368     if (!Matcher::has_match_rule(Op_CmpUL)) {
3369       // We don't support unsigned long comparisons. Set 'max_idx_expr'
3370       // to max_julong if < 0 to make the signed comparison fail.
3371       ConINode* sign_pos = new ConINode(TypeInt::make(BitsPerLong - 1));
3372       Node* sign_bit_mask = new RShiftLNode(n->in(1), sign_pos);
3373       Node* orl = new OrLNode(n->in(1), sign_bit_mask);
3374       ConLNode* remove_sign_mask = new ConLNode(TypeLong::make(max_jlong));
3375       Node* andl = new AndLNode(orl, remove_sign_mask);
3376       Node* cmp = new CmpLNode(andl, n->in(2));
3377       n->subsume_by(cmp, this);
3378     }
3379     break;
3380   }
3381   default:
3382     assert( !n->is_Call(), "" );
3383     assert( !n->is_Mem(), "" );
3384     assert( nop != Op_ProfileBoolean, "should be eliminated during IGVN");
3385     break;
3386   }
3387 
3388   // Collect CFG split points
3389   if (n->is_MultiBranch() && !n->is_RangeCheck()) {
3390     frc._tests.push(n);
3391   }
3392 }
3393 
3394 //------------------------------final_graph_reshaping_walk---------------------
3395 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
3396 // requires that the walk visits a node's inputs before visiting the node.
3397 void Compile::final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Reshape_Counts &frc ) {
3398   ResourceArea *area = Thread::current()->resource_area();
3399   Unique_Node_List sfpt(area);
3400 
3401   frc._visited.set(root->_idx); // first, mark node as visited
3402   uint cnt = root->req();
3403   Node *n = root;
3404   uint  i = 0;
3405   while (true) {
3406     if (i < cnt) {
3407       // Place all non-visited non-null inputs onto stack
3408       Node* m = n->in(i);
3409       ++i;
3410       if (m != NULL && !frc._visited.test_set(m->_idx)) {
3411         if (m->is_SafePoint() && m->as_SafePoint()->jvms() != NULL) {
3412           // compute worst case interpreter size in case of a deoptimization
3413           update_interpreter_frame_size(m->as_SafePoint()->jvms()->interpreter_frame_size());
3414 
3415           sfpt.push(m);
3416         }
3417         cnt = m->req();
3418         nstack.push(n, i); // put on stack parent and next input's index
3419         n = m;
3420         i = 0;
3421       }
3422     } else {
3423       // Now do post-visit work
3424       final_graph_reshaping_impl( n, frc );
3425       if (nstack.is_empty())
3426         break;             // finished
3427       n = nstack.node();   // Get node from stack
3428       cnt = n->req();
3429       i = nstack.index();
3430       nstack.pop();        // Shift to the next node on stack
3431     }
3432   }
3433 
3434   // Skip next transformation if compressed oops are not used.
3435   if ((UseCompressedOops && !Matcher::gen_narrow_oop_implicit_null_checks()) ||
3436       (!UseCompressedOops && !UseCompressedClassPointers))
3437     return;
3438 
3439   // Go over safepoints nodes to skip DecodeN/DecodeNKlass nodes for debug edges.
3440   // It could be done for an uncommon traps or any safepoints/calls
3441   // if the DecodeN/DecodeNKlass node is referenced only in a debug info.
3442   while (sfpt.size() > 0) {
3443     n = sfpt.pop();
3444     JVMState *jvms = n->as_SafePoint()->jvms();
3445     assert(jvms != NULL, "sanity");
3446     int start = jvms->debug_start();
3447     int end   = n->req();
3448     bool is_uncommon = (n->is_CallStaticJava() &&
3449                         n->as_CallStaticJava()->uncommon_trap_request() != 0);
3450     for (int j = start; j < end; j++) {
3451       Node* in = n->in(j);
3452       if (in->is_DecodeNarrowPtr()) {
3453         bool safe_to_skip = true;
3454         if (!is_uncommon ) {
3455           // Is it safe to skip?
3456           for (uint i = 0; i < in->outcnt(); i++) {
3457             Node* u = in->raw_out(i);
3458             if (!u->is_SafePoint() ||
3459                 (u->is_Call() && u->as_Call()->has_non_debug_use(n))) {
3460               safe_to_skip = false;
3461             }
3462           }
3463         }
3464         if (safe_to_skip) {
3465           n->set_req(j, in->in(1));
3466         }
3467         if (in->outcnt() == 0) {
3468           in->disconnect_inputs(NULL, this);
3469         }
3470       }
3471     }
3472   }
3473 }
3474 
3475 //------------------------------final_graph_reshaping--------------------------
3476 // Final Graph Reshaping.
3477 //
3478 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
3479 //     and not commoned up and forced early.  Must come after regular
3480 //     optimizations to avoid GVN undoing the cloning.  Clone constant
3481 //     inputs to Loop Phis; these will be split by the allocator anyways.
3482 //     Remove Opaque nodes.
3483 // (2) Move last-uses by commutative operations to the left input to encourage
3484 //     Intel update-in-place two-address operations and better register usage
3485 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
3486 //     calls canonicalizing them back.
3487 // (3) Count the number of double-precision FP ops, single-precision FP ops
3488 //     and call sites.  On Intel, we can get correct rounding either by
3489 //     forcing singles to memory (requires extra stores and loads after each
3490 //     FP bytecode) or we can set a rounding mode bit (requires setting and
3491 //     clearing the mode bit around call sites).  The mode bit is only used
3492 //     if the relative frequency of single FP ops to calls is low enough.
3493 //     This is a key transform for SPEC mpeg_audio.
3494 // (4) Detect infinite loops; blobs of code reachable from above but not
3495 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
3496 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
3497 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
3498 //     Detection is by looking for IfNodes where only 1 projection is
3499 //     reachable from below or CatchNodes missing some targets.
3500 // (5) Assert for insane oop offsets in debug mode.
3501 
3502 bool Compile::final_graph_reshaping() {
3503   // an infinite loop may have been eliminated by the optimizer,
3504   // in which case the graph will be empty.
3505   if (root()->req() == 1) {
3506     record_method_not_compilable("trivial infinite loop");
3507     return true;
3508   }
3509 
3510   // Expensive nodes have their control input set to prevent the GVN
3511   // from freely commoning them. There's no GVN beyond this point so
3512   // no need to keep the control input. We want the expensive nodes to
3513   // be freely moved to the least frequent code path by gcm.
3514   assert(OptimizeExpensiveOps || expensive_count() == 0, "optimization off but list non empty?");
3515   for (int i = 0; i < expensive_count(); i++) {
3516     _expensive_nodes->at(i)->set_req(0, NULL);
3517   }
3518 
3519   Final_Reshape_Counts frc;
3520 
3521   // Visit everybody reachable!
3522   // Allocate stack of size C->live_nodes()/2 to avoid frequent realloc
3523   Node_Stack nstack(live_nodes() >> 1);
3524   final_graph_reshaping_walk(nstack, root(), frc);
3525 
3526   // Check for unreachable (from below) code (i.e., infinite loops).
3527   for( uint i = 0; i < frc._tests.size(); i++ ) {
3528     MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
3529     // Get number of CFG targets.
3530     // Note that PCTables include exception targets after calls.
3531     uint required_outcnt = n->required_outcnt();
3532     if (n->outcnt() != required_outcnt) {
3533       // Check for a few special cases.  Rethrow Nodes never take the
3534       // 'fall-thru' path, so expected kids is 1 less.
3535       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
3536         if (n->in(0)->in(0)->is_Call()) {
3537           CallNode *call = n->in(0)->in(0)->as_Call();
3538           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
3539             required_outcnt--;      // Rethrow always has 1 less kid
3540           } else if (call->req() > TypeFunc::Parms &&
3541                      call->is_CallDynamicJava()) {
3542             // Check for null receiver. In such case, the optimizer has
3543             // detected that the virtual call will always result in a null
3544             // pointer exception. The fall-through projection of this CatchNode
3545             // will not be populated.
3546             Node *arg0 = call->in(TypeFunc::Parms);
3547             if (arg0->is_Type() &&
3548                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
3549               required_outcnt--;
3550             }
3551           } else if (call->entry_point() == OptoRuntime::new_array_Java() &&
3552                      call->req() > TypeFunc::Parms+1 &&
3553                      call->is_CallStaticJava()) {
3554             // Check for negative array length. In such case, the optimizer has
3555             // detected that the allocation attempt will always result in an
3556             // exception. There is no fall-through projection of this CatchNode .
3557             Node *arg1 = call->in(TypeFunc::Parms+1);
3558             if (arg1->is_Type() &&
3559                 arg1->as_Type()->type()->join(TypeInt::POS)->empty()) {
3560               required_outcnt--;
3561             }
3562           }
3563         }
3564       }
3565       // Recheck with a better notion of 'required_outcnt'
3566       if (n->outcnt() != required_outcnt) {
3567         record_method_not_compilable("malformed control flow");
3568         return true;            // Not all targets reachable!
3569       }
3570     }
3571     // Check that I actually visited all kids.  Unreached kids
3572     // must be infinite loops.
3573     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
3574       if (!frc._visited.test(n->fast_out(j)->_idx)) {
3575         record_method_not_compilable("infinite loop");
3576         return true;            // Found unvisited kid; must be unreach
3577       }
3578 
3579     // Here so verification code in final_graph_reshaping_walk()
3580     // always see an OuterStripMinedLoopEnd
3581     if (n->is_OuterStripMinedLoopEnd()) {
3582       IfNode* init_iff = n->as_If();
3583       Node* iff = new IfNode(init_iff->in(0), init_iff->in(1), init_iff->_prob, init_iff->_fcnt);
3584       n->subsume_by(iff, this);
3585     }
3586   }
3587 
3588   // If original bytecodes contained a mixture of floats and doubles
3589   // check if the optimizer has made it homogenous, item (3).
3590   if( Use24BitFPMode && Use24BitFP && UseSSE == 0 &&
3591       frc.get_float_count() > 32 &&
3592       frc.get_double_count() == 0 &&
3593       (10 * frc.get_call_count() < frc.get_float_count()) ) {
3594     set_24_bit_selection_and_mode( false,  true );
3595   }
3596 
3597   set_java_calls(frc.get_java_call_count());
3598   set_inner_loops(frc.get_inner_loop_count());
3599 
3600   // No infinite loops, no reason to bail out.
3601   return false;
3602 }
3603 
3604 //-----------------------------too_many_traps----------------------------------
3605 // Report if there are too many traps at the current method and bci.
3606 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
3607 bool Compile::too_many_traps(ciMethod* method,
3608                              int bci,
3609                              Deoptimization::DeoptReason reason) {
3610   ciMethodData* md = method->method_data();
3611   if (md->is_empty()) {
3612     // Assume the trap has not occurred, or that it occurred only
3613     // because of a transient condition during start-up in the interpreter.
3614     return false;
3615   }
3616   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
3617   if (md->has_trap_at(bci, m, reason) != 0) {
3618     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
3619     // Also, if there are multiple reasons, or if there is no per-BCI record,
3620     // assume the worst.
3621     if (log())
3622       log()->elem("observe trap='%s' count='%d'",
3623                   Deoptimization::trap_reason_name(reason),
3624                   md->trap_count(reason));
3625     return true;
3626   } else {
3627     // Ignore method/bci and see if there have been too many globally.
3628     return too_many_traps(reason, md);
3629   }
3630 }
3631 
3632 // Less-accurate variant which does not require a method and bci.
3633 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
3634                              ciMethodData* logmd) {
3635   if (trap_count(reason) >= Deoptimization::per_method_trap_limit(reason)) {
3636     // Too many traps globally.
3637     // Note that we use cumulative trap_count, not just md->trap_count.
3638     if (log()) {
3639       int mcount = (logmd == NULL)? -1: (int)logmd->trap_count(reason);
3640       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
3641                   Deoptimization::trap_reason_name(reason),
3642                   mcount, trap_count(reason));
3643     }
3644     return true;
3645   } else {
3646     // The coast is clear.
3647     return false;
3648   }
3649 }
3650 
3651 //--------------------------too_many_recompiles--------------------------------
3652 // Report if there are too many recompiles at the current method and bci.
3653 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
3654 // Is not eager to return true, since this will cause the compiler to use
3655 // Action_none for a trap point, to avoid too many recompilations.
3656 bool Compile::too_many_recompiles(ciMethod* method,
3657                                   int bci,
3658                                   Deoptimization::DeoptReason reason) {
3659   ciMethodData* md = method->method_data();
3660   if (md->is_empty()) {
3661     // Assume the trap has not occurred, or that it occurred only
3662     // because of a transient condition during start-up in the interpreter.
3663     return false;
3664   }
3665   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
3666   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
3667   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
3668   Deoptimization::DeoptReason per_bc_reason
3669     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
3670   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
3671   if ((per_bc_reason == Deoptimization::Reason_none
3672        || md->has_trap_at(bci, m, reason) != 0)
3673       // The trap frequency measure we care about is the recompile count:
3674       && md->trap_recompiled_at(bci, m)
3675       && md->overflow_recompile_count() >= bc_cutoff) {
3676     // Do not emit a trap here if it has already caused recompilations.
3677     // Also, if there are multiple reasons, or if there is no per-BCI record,
3678     // assume the worst.
3679     if (log())
3680       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
3681                   Deoptimization::trap_reason_name(reason),
3682                   md->trap_count(reason),
3683                   md->overflow_recompile_count());
3684     return true;
3685   } else if (trap_count(reason) != 0
3686              && decompile_count() >= m_cutoff) {
3687     // Too many recompiles globally, and we have seen this sort of trap.
3688     // Use cumulative decompile_count, not just md->decompile_count.
3689     if (log())
3690       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
3691                   Deoptimization::trap_reason_name(reason),
3692                   md->trap_count(reason), trap_count(reason),
3693                   md->decompile_count(), decompile_count());
3694     return true;
3695   } else {
3696     // The coast is clear.
3697     return false;
3698   }
3699 }
3700 
3701 // Compute when not to trap. Used by matching trap based nodes and
3702 // NullCheck optimization.
3703 void Compile::set_allowed_deopt_reasons() {
3704   _allowed_reasons = 0;
3705   if (is_method_compilation()) {
3706     for (int rs = (int)Deoptimization::Reason_none+1; rs < Compile::trapHistLength; rs++) {
3707       assert(rs < BitsPerInt, "recode bit map");
3708       if (!too_many_traps((Deoptimization::DeoptReason) rs)) {
3709         _allowed_reasons |= nth_bit(rs);
3710       }
3711     }
3712   }
3713 }
3714 
3715 #ifndef PRODUCT
3716 //------------------------------verify_graph_edges---------------------------
3717 // Walk the Graph and verify that there is a one-to-one correspondence
3718 // between Use-Def edges and Def-Use edges in the graph.
3719 void Compile::verify_graph_edges(bool no_dead_code) {
3720   if (VerifyGraphEdges) {
3721     ResourceArea *area = Thread::current()->resource_area();
3722     Unique_Node_List visited(area);
3723     // Call recursive graph walk to check edges
3724     _root->verify_edges(visited);
3725     if (no_dead_code) {
3726       // Now make sure that no visited node is used by an unvisited node.
3727       bool dead_nodes = false;
3728       Unique_Node_List checked(area);
3729       while (visited.size() > 0) {
3730         Node* n = visited.pop();
3731         checked.push(n);
3732         for (uint i = 0; i < n->outcnt(); i++) {
3733           Node* use = n->raw_out(i);
3734           if (checked.member(use))  continue;  // already checked
3735           if (visited.member(use))  continue;  // already in the graph
3736           if (use->is_Con())        continue;  // a dead ConNode is OK
3737           // At this point, we have found a dead node which is DU-reachable.
3738           if (!dead_nodes) {
3739             tty->print_cr("*** Dead nodes reachable via DU edges:");
3740             dead_nodes = true;
3741           }
3742           use->dump(2);
3743           tty->print_cr("---");
3744           checked.push(use);  // No repeats; pretend it is now checked.
3745         }
3746       }
3747       assert(!dead_nodes, "using nodes must be reachable from root");
3748     }
3749   }
3750 }
3751 
3752 // Verify GC barriers consistency
3753 // Currently supported:
3754 // - G1 pre-barriers (see GraphKit::g1_write_barrier_pre())
3755 void Compile::verify_barriers() {
3756   if (UseG1GC) {
3757     // Verify G1 pre-barriers
3758     const int marking_offset = in_bytes(G1ThreadLocalData::satb_mark_queue_active_offset());
3759 
3760     ResourceArea *area = Thread::current()->resource_area();
3761     Unique_Node_List visited(area);
3762     Node_List worklist(area);
3763     // We're going to walk control flow backwards starting from the Root
3764     worklist.push(_root);
3765     while (worklist.size() > 0) {
3766       Node* x = worklist.pop();
3767       if (x == NULL || x == top()) continue;
3768       if (visited.member(x)) {
3769         continue;
3770       } else {
3771         visited.push(x);
3772       }
3773 
3774       if (x->is_Region()) {
3775         for (uint i = 1; i < x->req(); i++) {
3776           worklist.push(x->in(i));
3777         }
3778       } else {
3779         worklist.push(x->in(0));
3780         // We are looking for the pattern:
3781         //                            /->ThreadLocal
3782         // If->Bool->CmpI->LoadB->AddP->ConL(marking_offset)
3783         //              \->ConI(0)
3784         // We want to verify that the If and the LoadB have the same control
3785         // See GraphKit::g1_write_barrier_pre()
3786         if (x->is_If()) {
3787           IfNode *iff = x->as_If();
3788           if (iff->in(1)->is_Bool() && iff->in(1)->in(1)->is_Cmp()) {
3789             CmpNode *cmp = iff->in(1)->in(1)->as_Cmp();
3790             if (cmp->Opcode() == Op_CmpI && cmp->in(2)->is_Con() && cmp->in(2)->bottom_type()->is_int()->get_con() == 0
3791                 && cmp->in(1)->is_Load()) {
3792               LoadNode* load = cmp->in(1)->as_Load();
3793               if (load->Opcode() == Op_LoadB && load->in(2)->is_AddP() && load->in(2)->in(2)->Opcode() == Op_ThreadLocal
3794                   && load->in(2)->in(3)->is_Con()
3795                   && load->in(2)->in(3)->bottom_type()->is_intptr_t()->get_con() == marking_offset) {
3796 
3797                 Node* if_ctrl = iff->in(0);
3798                 Node* load_ctrl = load->in(0);
3799 
3800                 if (if_ctrl != load_ctrl) {
3801                   // Skip possible CProj->NeverBranch in infinite loops
3802                   if ((if_ctrl->is_Proj() && if_ctrl->Opcode() == Op_CProj)
3803                       && (if_ctrl->in(0)->is_MultiBranch() && if_ctrl->in(0)->Opcode() == Op_NeverBranch)) {
3804                     if_ctrl = if_ctrl->in(0)->in(0);
3805                   }
3806                 }
3807                 assert(load_ctrl != NULL && if_ctrl == load_ctrl, "controls must match");
3808               }
3809             }
3810           }
3811         }
3812       }
3813     }
3814   }
3815 }
3816 
3817 #endif
3818 
3819 // The Compile object keeps track of failure reasons separately from the ciEnv.
3820 // This is required because there is not quite a 1-1 relation between the
3821 // ciEnv and its compilation task and the Compile object.  Note that one
3822 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
3823 // to backtrack and retry without subsuming loads.  Other than this backtracking
3824 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
3825 // by the logic in C2Compiler.
3826 void Compile::record_failure(const char* reason) {
3827   if (log() != NULL) {
3828     log()->elem("failure reason='%s' phase='compile'", reason);
3829   }
3830   if (_failure_reason == NULL) {
3831     // Record the first failure reason.
3832     _failure_reason = reason;
3833   }
3834 
3835   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
3836     C->print_method(PHASE_FAILURE);
3837   }
3838   _root = NULL;  // flush the graph, too
3839 }
3840 
3841 Compile::TracePhase::TracePhase(const char* name, elapsedTimer* accumulator)
3842   : TraceTime(name, accumulator, CITime, CITimeVerbose),
3843     _phase_name(name), _dolog(CITimeVerbose)
3844 {
3845   if (_dolog) {
3846     C = Compile::current();
3847     _log = C->log();
3848   } else {
3849     C = NULL;
3850     _log = NULL;
3851   }
3852   if (_log != NULL) {
3853     _log->begin_head("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
3854     _log->stamp();
3855     _log->end_head();
3856   }
3857 }
3858 
3859 Compile::TracePhase::~TracePhase() {
3860 
3861   C = Compile::current();
3862   if (_dolog) {
3863     _log = C->log();
3864   } else {
3865     _log = NULL;
3866   }
3867 
3868 #ifdef ASSERT
3869   if (PrintIdealNodeCount) {
3870     tty->print_cr("phase name='%s' nodes='%d' live='%d' live_graph_walk='%d'",
3871                   _phase_name, C->unique(), C->live_nodes(), C->count_live_nodes_by_graph_walk());
3872   }
3873 
3874   if (VerifyIdealNodeCount) {
3875     Compile::current()->print_missing_nodes();
3876   }
3877 #endif
3878 
3879   if (_log != NULL) {
3880     _log->done("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
3881   }
3882 }
3883 
3884 //=============================================================================
3885 // Two Constant's are equal when the type and the value are equal.
3886 bool Compile::Constant::operator==(const Constant& other) {
3887   if (type()          != other.type()         )  return false;
3888   if (can_be_reused() != other.can_be_reused())  return false;
3889   // For floating point values we compare the bit pattern.
3890   switch (type()) {
3891   case T_INT:
3892   case T_FLOAT:   return (_v._value.i == other._v._value.i);
3893   case T_LONG:
3894   case T_DOUBLE:  return (_v._value.j == other._v._value.j);
3895   case T_OBJECT:
3896   case T_ADDRESS: return (_v._value.l == other._v._value.l);
3897   case T_VOID:    return (_v._value.l == other._v._value.l);  // jump-table entries
3898   case T_METADATA: return (_v._metadata == other._v._metadata);
3899   default: ShouldNotReachHere(); return false;
3900   }
3901 }
3902 
3903 static int type_to_size_in_bytes(BasicType t) {
3904   switch (t) {
3905   case T_INT:     return sizeof(jint   );
3906   case T_LONG:    return sizeof(jlong  );
3907   case T_FLOAT:   return sizeof(jfloat );
3908   case T_DOUBLE:  return sizeof(jdouble);
3909   case T_METADATA: return sizeof(Metadata*);
3910     // We use T_VOID as marker for jump-table entries (labels) which
3911     // need an internal word relocation.
3912   case T_VOID:
3913   case T_ADDRESS:
3914   case T_OBJECT:  return sizeof(jobject);
3915   default:
3916     ShouldNotReachHere();
3917     return -1;
3918   }
3919 }
3920 
3921 int Compile::ConstantTable::qsort_comparator(Constant* a, Constant* b) {
3922   // sort descending
3923   if (a->freq() > b->freq())  return -1;
3924   if (a->freq() < b->freq())  return  1;
3925   return 0;
3926 }
3927 
3928 void Compile::ConstantTable::calculate_offsets_and_size() {
3929   // First, sort the array by frequencies.
3930   _constants.sort(qsort_comparator);
3931 
3932 #ifdef ASSERT
3933   // Make sure all jump-table entries were sorted to the end of the
3934   // array (they have a negative frequency).
3935   bool found_void = false;
3936   for (int i = 0; i < _constants.length(); i++) {
3937     Constant con = _constants.at(i);
3938     if (con.type() == T_VOID)
3939       found_void = true;  // jump-tables
3940     else
3941       assert(!found_void, "wrong sorting");
3942   }
3943 #endif
3944 
3945   int offset = 0;
3946   for (int i = 0; i < _constants.length(); i++) {
3947     Constant* con = _constants.adr_at(i);
3948 
3949     // Align offset for type.
3950     int typesize = type_to_size_in_bytes(con->type());
3951     offset = align_up(offset, typesize);
3952     con->set_offset(offset);   // set constant's offset
3953 
3954     if (con->type() == T_VOID) {
3955       MachConstantNode* n = (MachConstantNode*) con->get_jobject();
3956       offset = offset + typesize * n->outcnt();  // expand jump-table
3957     } else {
3958       offset = offset + typesize;
3959     }
3960   }
3961 
3962   // Align size up to the next section start (which is insts; see
3963   // CodeBuffer::align_at_start).
3964   assert(_size == -1, "already set?");
3965   _size = align_up(offset, (int)CodeEntryAlignment);
3966 }
3967 
3968 void Compile::ConstantTable::emit(CodeBuffer& cb) {
3969   MacroAssembler _masm(&cb);
3970   for (int i = 0; i < _constants.length(); i++) {
3971     Constant con = _constants.at(i);
3972     address constant_addr = NULL;
3973     switch (con.type()) {
3974     case T_INT:    constant_addr = _masm.int_constant(   con.get_jint()   ); break;
3975     case T_LONG:   constant_addr = _masm.long_constant(  con.get_jlong()  ); break;
3976     case T_FLOAT:  constant_addr = _masm.float_constant( con.get_jfloat() ); break;
3977     case T_DOUBLE: constant_addr = _masm.double_constant(con.get_jdouble()); break;
3978     case T_OBJECT: {
3979       jobject obj = con.get_jobject();
3980       int oop_index = _masm.oop_recorder()->find_index(obj);
3981       constant_addr = _masm.address_constant((address) obj, oop_Relocation::spec(oop_index));
3982       break;
3983     }
3984     case T_ADDRESS: {
3985       address addr = (address) con.get_jobject();
3986       constant_addr = _masm.address_constant(addr);
3987       break;
3988     }
3989     // We use T_VOID as marker for jump-table entries (labels) which
3990     // need an internal word relocation.
3991     case T_VOID: {
3992       MachConstantNode* n = (MachConstantNode*) con.get_jobject();
3993       // Fill the jump-table with a dummy word.  The real value is
3994       // filled in later in fill_jump_table.
3995       address dummy = (address) n;
3996       constant_addr = _masm.address_constant(dummy);
3997       // Expand jump-table
3998       for (uint i = 1; i < n->outcnt(); i++) {
3999         address temp_addr = _masm.address_constant(dummy + i);
4000         assert(temp_addr, "consts section too small");
4001       }
4002       break;
4003     }
4004     case T_METADATA: {
4005       Metadata* obj = con.get_metadata();
4006       int metadata_index = _masm.oop_recorder()->find_index(obj);
4007       constant_addr = _masm.address_constant((address) obj, metadata_Relocation::spec(metadata_index));
4008       break;
4009     }
4010     default: ShouldNotReachHere();
4011     }
4012     assert(constant_addr, "consts section too small");
4013     assert((constant_addr - _masm.code()->consts()->start()) == con.offset(),
4014             "must be: %d == %d", (int) (constant_addr - _masm.code()->consts()->start()), (int)(con.offset()));
4015   }
4016 }
4017 
4018 int Compile::ConstantTable::find_offset(Constant& con) const {
4019   int idx = _constants.find(con);
4020   assert(idx != -1, "constant must be in constant table");
4021   int offset = _constants.at(idx).offset();
4022   assert(offset != -1, "constant table not emitted yet?");
4023   return offset;
4024 }
4025 
4026 void Compile::ConstantTable::add(Constant& con) {
4027   if (con.can_be_reused()) {
4028     int idx = _constants.find(con);
4029     if (idx != -1 && _constants.at(idx).can_be_reused()) {
4030       _constants.adr_at(idx)->inc_freq(con.freq());  // increase the frequency by the current value
4031       return;
4032     }
4033   }
4034   (void) _constants.append(con);
4035 }
4036 
4037 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, BasicType type, jvalue value) {
4038   Block* b = Compile::current()->cfg()->get_block_for_node(n);
4039   Constant con(type, value, b->_freq);
4040   add(con);
4041   return con;
4042 }
4043 
4044 Compile::Constant Compile::ConstantTable::add(Metadata* metadata) {
4045   Constant con(metadata);
4046   add(con);
4047   return con;
4048 }
4049 
4050 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, MachOper* oper) {
4051   jvalue value;
4052   BasicType type = oper->type()->basic_type();
4053   switch (type) {
4054   case T_LONG:    value.j = oper->constantL(); break;
4055   case T_FLOAT:   value.f = oper->constantF(); break;
4056   case T_DOUBLE:  value.d = oper->constantD(); break;
4057   case T_OBJECT:
4058   case T_ADDRESS: value.l = (jobject) oper->constant(); break;
4059   case T_METADATA: return add((Metadata*)oper->constant()); break;
4060   default: guarantee(false, "unhandled type: %s", type2name(type));
4061   }
4062   return add(n, type, value);
4063 }
4064 
4065 Compile::Constant Compile::ConstantTable::add_jump_table(MachConstantNode* n) {
4066   jvalue value;
4067   // We can use the node pointer here to identify the right jump-table
4068   // as this method is called from Compile::Fill_buffer right before
4069   // the MachNodes are emitted and the jump-table is filled (means the
4070   // MachNode pointers do not change anymore).
4071   value.l = (jobject) n;
4072   Constant con(T_VOID, value, next_jump_table_freq(), false);  // Labels of a jump-table cannot be reused.
4073   add(con);
4074   return con;
4075 }
4076 
4077 void Compile::ConstantTable::fill_jump_table(CodeBuffer& cb, MachConstantNode* n, GrowableArray<Label*> labels) const {
4078   // If called from Compile::scratch_emit_size do nothing.
4079   if (Compile::current()->in_scratch_emit_size())  return;
4080 
4081   assert(labels.is_nonempty(), "must be");
4082   assert((uint) labels.length() == n->outcnt(), "must be equal: %d == %d", labels.length(), n->outcnt());
4083 
4084   // Since MachConstantNode::constant_offset() also contains
4085   // table_base_offset() we need to subtract the table_base_offset()
4086   // to get the plain offset into the constant table.
4087   int offset = n->constant_offset() - table_base_offset();
4088 
4089   MacroAssembler _masm(&cb);
4090   address* jump_table_base = (address*) (_masm.code()->consts()->start() + offset);
4091 
4092   for (uint i = 0; i < n->outcnt(); i++) {
4093     address* constant_addr = &jump_table_base[i];
4094     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));
4095     *constant_addr = cb.consts()->target(*labels.at(i), (address) constant_addr);
4096     cb.consts()->relocate((address) constant_addr, relocInfo::internal_word_type);
4097   }
4098 }
4099 
4100 //----------------------------static_subtype_check-----------------------------
4101 // Shortcut important common cases when superklass is exact:
4102 // (0) superklass is java.lang.Object (can occur in reflective code)
4103 // (1) subklass is already limited to a subtype of superklass => always ok
4104 // (2) subklass does not overlap with superklass => always fail
4105 // (3) superklass has NO subtypes and we can check with a simple compare.
4106 int Compile::static_subtype_check(ciKlass* superk, ciKlass* subk) {
4107   if (StressReflectiveCode) {
4108     return SSC_full_test;       // Let caller generate the general case.
4109   }
4110 
4111   if (superk == env()->Object_klass()) {
4112     return SSC_always_true;     // (0) this test cannot fail
4113   }
4114 
4115   ciType* superelem = superk;
4116   if (superelem->is_array_klass())
4117     superelem = superelem->as_array_klass()->base_element_type();
4118 
4119   if (!subk->is_interface()) {  // cannot trust static interface types yet
4120     if (subk->is_subtype_of(superk)) {
4121       return SSC_always_true;   // (1) false path dead; no dynamic test needed
4122     }
4123     if (!(superelem->is_klass() && superelem->as_klass()->is_interface()) &&
4124         !superk->is_subtype_of(subk)) {
4125       return SSC_always_false;
4126     }
4127   }
4128 
4129   // If casting to an instance klass, it must have no subtypes
4130   if (superk->is_interface()) {
4131     // Cannot trust interfaces yet.
4132     // %%% S.B. superk->nof_implementors() == 1
4133   } else if (superelem->is_instance_klass()) {
4134     ciInstanceKlass* ik = superelem->as_instance_klass();
4135     if (!ik->has_subklass() && !ik->is_interface()) {
4136       if (!ik->is_final()) {
4137         // Add a dependency if there is a chance of a later subclass.
4138         dependencies()->assert_leaf_type(ik);
4139       }
4140       return SSC_easy_test;     // (3) caller can do a simple ptr comparison
4141     }
4142   } else {
4143     // A primitive array type has no subtypes.
4144     return SSC_easy_test;       // (3) caller can do a simple ptr comparison
4145   }
4146 
4147   return SSC_full_test;
4148 }
4149 
4150 Node* Compile::conv_I2X_index(PhaseGVN* phase, Node* idx, const TypeInt* sizetype, Node* ctrl) {
4151 #ifdef _LP64
4152   // The scaled index operand to AddP must be a clean 64-bit value.
4153   // Java allows a 32-bit int to be incremented to a negative
4154   // value, which appears in a 64-bit register as a large
4155   // positive number.  Using that large positive number as an
4156   // operand in pointer arithmetic has bad consequences.
4157   // On the other hand, 32-bit overflow is rare, and the possibility
4158   // can often be excluded, if we annotate the ConvI2L node with
4159   // a type assertion that its value is known to be a small positive
4160   // number.  (The prior range check has ensured this.)
4161   // This assertion is used by ConvI2LNode::Ideal.
4162   int index_max = max_jint - 1;  // array size is max_jint, index is one less
4163   if (sizetype != NULL) index_max = sizetype->_hi - 1;
4164   const TypeInt* iidxtype = TypeInt::make(0, index_max, Type::WidenMax);
4165   idx = constrained_convI2L(phase, idx, iidxtype, ctrl);
4166 #endif
4167   return idx;
4168 }
4169 
4170 // Convert integer value to a narrowed long type dependent on ctrl (for example, a range check)
4171 Node* Compile::constrained_convI2L(PhaseGVN* phase, Node* value, const TypeInt* itype, Node* ctrl) {
4172   if (ctrl != NULL) {
4173     // Express control dependency by a CastII node with a narrow type.
4174     value = new CastIINode(value, itype, false, true /* range check dependency */);
4175     // Make the CastII node dependent on the control input to prevent the narrowed ConvI2L
4176     // node from floating above the range check during loop optimizations. Otherwise, the
4177     // ConvI2L node may be eliminated independently of the range check, causing the data path
4178     // to become TOP while the control path is still there (although it's unreachable).
4179     value->set_req(0, ctrl);
4180     // Save CastII node to remove it after loop optimizations.
4181     phase->C->add_range_check_cast(value);
4182     value = phase->transform(value);
4183   }
4184   const TypeLong* ltype = TypeLong::make(itype->_lo, itype->_hi, itype->_widen);
4185   return phase->transform(new ConvI2LNode(value, ltype));
4186 }
4187 
4188 // The message about the current inlining is accumulated in
4189 // _print_inlining_stream and transfered into the _print_inlining_list
4190 // once we know whether inlining succeeds or not. For regular
4191 // inlining, messages are appended to the buffer pointed by
4192 // _print_inlining_idx in the _print_inlining_list. For late inlining,
4193 // a new buffer is added after _print_inlining_idx in the list. This
4194 // way we can update the inlining message for late inlining call site
4195 // when the inlining is attempted again.
4196 void Compile::print_inlining_init() {
4197   if (print_inlining() || print_intrinsics()) {
4198     _print_inlining_stream = new stringStream();
4199     _print_inlining_list = new (comp_arena())GrowableArray<PrintInliningBuffer>(comp_arena(), 1, 1, PrintInliningBuffer());
4200   }
4201 }
4202 
4203 void Compile::print_inlining_reinit() {
4204   if (print_inlining() || print_intrinsics()) {
4205     // Re allocate buffer when we change ResourceMark
4206     _print_inlining_stream = new stringStream();
4207   }
4208 }
4209 
4210 void Compile::print_inlining_reset() {
4211   _print_inlining_stream->reset();
4212 }
4213 
4214 void Compile::print_inlining_commit() {
4215   assert(print_inlining() || print_intrinsics(), "PrintInlining off?");
4216   // Transfer the message from _print_inlining_stream to the current
4217   // _print_inlining_list buffer and clear _print_inlining_stream.
4218   _print_inlining_list->at(_print_inlining_idx).ss()->write(_print_inlining_stream->as_string(), _print_inlining_stream->size());
4219   print_inlining_reset();
4220 }
4221 
4222 void Compile::print_inlining_push() {
4223   // Add new buffer to the _print_inlining_list at current position
4224   _print_inlining_idx++;
4225   _print_inlining_list->insert_before(_print_inlining_idx, PrintInliningBuffer());
4226 }
4227 
4228 Compile::PrintInliningBuffer& Compile::print_inlining_current() {
4229   return _print_inlining_list->at(_print_inlining_idx);
4230 }
4231 
4232 void Compile::print_inlining_update(CallGenerator* cg) {
4233   if (print_inlining() || print_intrinsics()) {
4234     if (!cg->is_late_inline()) {
4235       if (print_inlining_current().cg() != NULL) {
4236         print_inlining_push();
4237       }
4238       print_inlining_commit();
4239     } else {
4240       if (print_inlining_current().cg() != cg &&
4241           (print_inlining_current().cg() != NULL ||
4242            print_inlining_current().ss()->size() != 0)) {
4243         print_inlining_push();
4244       }
4245       print_inlining_commit();
4246       print_inlining_current().set_cg(cg);
4247     }
4248   }
4249 }
4250 
4251 void Compile::print_inlining_move_to(CallGenerator* cg) {
4252   // We resume inlining at a late inlining call site. Locate the
4253   // corresponding inlining buffer so that we can update it.
4254   if (print_inlining()) {
4255     for (int i = 0; i < _print_inlining_list->length(); i++) {
4256       if (_print_inlining_list->adr_at(i)->cg() == cg) {
4257         _print_inlining_idx = i;
4258         return;
4259       }
4260     }
4261     ShouldNotReachHere();
4262   }
4263 }
4264 
4265 void Compile::print_inlining_update_delayed(CallGenerator* cg) {
4266   if (print_inlining()) {
4267     assert(_print_inlining_stream->size() > 0, "missing inlining msg");
4268     assert(print_inlining_current().cg() == cg, "wrong entry");
4269     // replace message with new message
4270     _print_inlining_list->at_put(_print_inlining_idx, PrintInliningBuffer());
4271     print_inlining_commit();
4272     print_inlining_current().set_cg(cg);
4273   }
4274 }
4275 
4276 void Compile::print_inlining_assert_ready() {
4277   assert(!_print_inlining || _print_inlining_stream->size() == 0, "loosing data");
4278 }
4279 
4280 void Compile::process_print_inlining() {
4281   bool do_print_inlining = print_inlining() || print_intrinsics();
4282   if (do_print_inlining || log() != NULL) {
4283     // Print inlining message for candidates that we couldn't inline
4284     // for lack of space
4285     for (int i = 0; i < _late_inlines.length(); i++) {
4286       CallGenerator* cg = _late_inlines.at(i);
4287       if (!cg->is_mh_late_inline()) {
4288         const char* msg = "live nodes > LiveNodeCountInliningCutoff";
4289         if (do_print_inlining) {
4290           cg->print_inlining_late(msg);
4291         }
4292         log_late_inline_failure(cg, msg);
4293       }
4294     }
4295   }
4296   if (do_print_inlining) {
4297     ResourceMark rm;
4298     stringStream ss;
4299     for (int i = 0; i < _print_inlining_list->length(); i++) {
4300       ss.print("%s", _print_inlining_list->adr_at(i)->ss()->as_string());
4301     }
4302     size_t end = ss.size();
4303     _print_inlining_output = NEW_ARENA_ARRAY(comp_arena(), char, end+1);
4304     strncpy(_print_inlining_output, ss.base(), end+1);
4305     _print_inlining_output[end] = 0;
4306   }
4307 }
4308 
4309 void Compile::dump_print_inlining() {
4310   if (_print_inlining_output != NULL) {
4311     tty->print_raw(_print_inlining_output);
4312   }
4313 }
4314 
4315 void Compile::log_late_inline(CallGenerator* cg) {
4316   if (log() != NULL) {
4317     log()->head("late_inline method='%d'  inline_id='" JLONG_FORMAT "'", log()->identify(cg->method()),
4318                 cg->unique_id());
4319     JVMState* p = cg->call_node()->jvms();
4320     while (p != NULL) {
4321       log()->elem("jvms bci='%d' method='%d'", p->bci(), log()->identify(p->method()));
4322       p = p->caller();
4323     }
4324     log()->tail("late_inline");
4325   }
4326 }
4327 
4328 void Compile::log_late_inline_failure(CallGenerator* cg, const char* msg) {
4329   log_late_inline(cg);
4330   if (log() != NULL) {
4331     log()->inline_fail(msg);
4332   }
4333 }
4334 
4335 void Compile::log_inline_id(CallGenerator* cg) {
4336   if (log() != NULL) {
4337     // The LogCompilation tool needs a unique way to identify late
4338     // inline call sites. This id must be unique for this call site in
4339     // this compilation. Try to have it unique across compilations as
4340     // well because it can be convenient when grepping through the log
4341     // file.
4342     // Distinguish OSR compilations from others in case CICountOSR is
4343     // on.
4344     jlong id = ((jlong)unique()) + (((jlong)compile_id()) << 33) + (CICountOSR && is_osr_compilation() ? ((jlong)1) << 32 : 0);
4345     cg->set_unique_id(id);
4346     log()->elem("inline_id id='" JLONG_FORMAT "'", id);
4347   }
4348 }
4349 
4350 void Compile::log_inline_failure(const char* msg) {
4351   if (C->log() != NULL) {
4352     C->log()->inline_fail(msg);
4353   }
4354 }
4355 
4356 
4357 // Dump inlining replay data to the stream.
4358 // Don't change thread state and acquire any locks.
4359 void Compile::dump_inline_data(outputStream* out) {
4360   InlineTree* inl_tree = ilt();
4361   if (inl_tree != NULL) {
4362     out->print(" inline %d", inl_tree->count());
4363     inl_tree->dump_replay_data(out);
4364   }
4365 }
4366 
4367 int Compile::cmp_expensive_nodes(Node* n1, Node* n2) {
4368   if (n1->Opcode() < n2->Opcode())      return -1;
4369   else if (n1->Opcode() > n2->Opcode()) return 1;
4370 
4371   assert(n1->req() == n2->req(), "can't compare %s nodes: n1->req() = %d, n2->req() = %d", NodeClassNames[n1->Opcode()], n1->req(), n2->req());
4372   for (uint i = 1; i < n1->req(); i++) {
4373     if (n1->in(i) < n2->in(i))      return -1;
4374     else if (n1->in(i) > n2->in(i)) return 1;
4375   }
4376 
4377   return 0;
4378 }
4379 
4380 int Compile::cmp_expensive_nodes(Node** n1p, Node** n2p) {
4381   Node* n1 = *n1p;
4382   Node* n2 = *n2p;
4383 
4384   return cmp_expensive_nodes(n1, n2);
4385 }
4386 
4387 void Compile::sort_expensive_nodes() {
4388   if (!expensive_nodes_sorted()) {
4389     _expensive_nodes->sort(cmp_expensive_nodes);
4390   }
4391 }
4392 
4393 bool Compile::expensive_nodes_sorted() const {
4394   for (int i = 1; i < _expensive_nodes->length(); i++) {
4395     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i-1)) < 0) {
4396       return false;
4397     }
4398   }
4399   return true;
4400 }
4401 
4402 bool Compile::should_optimize_expensive_nodes(PhaseIterGVN &igvn) {
4403   if (_expensive_nodes->length() == 0) {
4404     return false;
4405   }
4406 
4407   assert(OptimizeExpensiveOps, "optimization off?");
4408 
4409   // Take this opportunity to remove dead nodes from the list
4410   int j = 0;
4411   for (int i = 0; i < _expensive_nodes->length(); i++) {
4412     Node* n = _expensive_nodes->at(i);
4413     if (!n->is_unreachable(igvn)) {
4414       assert(n->is_expensive(), "should be expensive");
4415       _expensive_nodes->at_put(j, n);
4416       j++;
4417     }
4418   }
4419   _expensive_nodes->trunc_to(j);
4420 
4421   // Then sort the list so that similar nodes are next to each other
4422   // and check for at least two nodes of identical kind with same data
4423   // inputs.
4424   sort_expensive_nodes();
4425 
4426   for (int i = 0; i < _expensive_nodes->length()-1; i++) {
4427     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i+1)) == 0) {
4428       return true;
4429     }
4430   }
4431 
4432   return false;
4433 }
4434 
4435 void Compile::cleanup_expensive_nodes(PhaseIterGVN &igvn) {
4436   if (_expensive_nodes->length() == 0) {
4437     return;
4438   }
4439 
4440   assert(OptimizeExpensiveOps, "optimization off?");
4441 
4442   // Sort to bring similar nodes next to each other and clear the
4443   // control input of nodes for which there's only a single copy.
4444   sort_expensive_nodes();
4445 
4446   int j = 0;
4447   int identical = 0;
4448   int i = 0;
4449   bool modified = false;
4450   for (; i < _expensive_nodes->length()-1; i++) {
4451     assert(j <= i, "can't write beyond current index");
4452     if (_expensive_nodes->at(i)->Opcode() == _expensive_nodes->at(i+1)->Opcode()) {
4453       identical++;
4454       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4455       continue;
4456     }
4457     if (identical > 0) {
4458       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4459       identical = 0;
4460     } else {
4461       Node* n = _expensive_nodes->at(i);
4462       igvn.replace_input_of(n, 0, NULL);
4463       igvn.hash_insert(n);
4464       modified = true;
4465     }
4466   }
4467   if (identical > 0) {
4468     _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4469   } else if (_expensive_nodes->length() >= 1) {
4470     Node* n = _expensive_nodes->at(i);
4471     igvn.replace_input_of(n, 0, NULL);
4472     igvn.hash_insert(n);
4473     modified = true;
4474   }
4475   _expensive_nodes->trunc_to(j);
4476   if (modified) {
4477     igvn.optimize();
4478   }
4479 }
4480 
4481 void Compile::add_expensive_node(Node * n) {
4482   assert(!_expensive_nodes->contains(n), "duplicate entry in expensive list");
4483   assert(n->is_expensive(), "expensive nodes with non-null control here only");
4484   assert(!n->is_CFG() && !n->is_Mem(), "no cfg or memory nodes here");
4485   if (OptimizeExpensiveOps) {
4486     _expensive_nodes->append(n);
4487   } else {
4488     // Clear control input and let IGVN optimize expensive nodes if
4489     // OptimizeExpensiveOps is off.
4490     n->set_req(0, NULL);
4491   }
4492 }
4493 
4494 /**
4495  * Remove the speculative part of types and clean up the graph
4496  */
4497 void Compile::remove_speculative_types(PhaseIterGVN &igvn) {
4498   if (UseTypeSpeculation) {
4499     Unique_Node_List worklist;
4500     worklist.push(root());
4501     int modified = 0;
4502     // Go over all type nodes that carry a speculative type, drop the
4503     // speculative part of the type and enqueue the node for an igvn
4504     // which may optimize it out.
4505     for (uint next = 0; next < worklist.size(); ++next) {
4506       Node *n  = worklist.at(next);
4507       if (n->is_Type()) {
4508         TypeNode* tn = n->as_Type();
4509         const Type* t = tn->type();
4510         const Type* t_no_spec = t->remove_speculative();
4511         if (t_no_spec != t) {
4512           bool in_hash = igvn.hash_delete(n);
4513           assert(in_hash, "node should be in igvn hash table");
4514           tn->set_type(t_no_spec);
4515           igvn.hash_insert(n);
4516           igvn._worklist.push(n); // give it a chance to go away
4517           modified++;
4518         }
4519       }
4520       uint max = n->len();
4521       for( uint i = 0; i < max; ++i ) {
4522         Node *m = n->in(i);
4523         if (not_a_node(m))  continue;
4524         worklist.push(m);
4525       }
4526     }
4527     // Drop the speculative part of all types in the igvn's type table
4528     igvn.remove_speculative_types();
4529     if (modified > 0) {
4530       igvn.optimize();
4531     }
4532 #ifdef ASSERT
4533     // Verify that after the IGVN is over no speculative type has resurfaced
4534     worklist.clear();
4535     worklist.push(root());
4536     for (uint next = 0; next < worklist.size(); ++next) {
4537       Node *n  = worklist.at(next);
4538       const Type* t = igvn.type_or_null(n);
4539       assert((t == NULL) || (t == t->remove_speculative()), "no more speculative types");
4540       if (n->is_Type()) {
4541         t = n->as_Type()->type();
4542         assert(t == t->remove_speculative(), "no more speculative types");
4543       }
4544       uint max = n->len();
4545       for( uint i = 0; i < max; ++i ) {
4546         Node *m = n->in(i);
4547         if (not_a_node(m))  continue;
4548         worklist.push(m);
4549       }
4550     }
4551     igvn.check_no_speculative_types();
4552 #endif
4553   }
4554 }
4555 
4556 // Auxiliary method to support randomized stressing/fuzzing.
4557 //
4558 // This method can be called the arbitrary number of times, with current count
4559 // as the argument. The logic allows selecting a single candidate from the
4560 // running list of candidates as follows:
4561 //    int count = 0;
4562 //    Cand* selected = null;
4563 //    while(cand = cand->next()) {
4564 //      if (randomized_select(++count)) {
4565 //        selected = cand;
4566 //      }
4567 //    }
4568 //
4569 // Including count equalizes the chances any candidate is "selected".
4570 // This is useful when we don't have the complete list of candidates to choose
4571 // from uniformly. In this case, we need to adjust the randomicity of the
4572 // selection, or else we will end up biasing the selection towards the latter
4573 // candidates.
4574 //
4575 // Quick back-envelope calculation shows that for the list of n candidates
4576 // the equal probability for the candidate to persist as "best" can be
4577 // achieved by replacing it with "next" k-th candidate with the probability
4578 // of 1/k. It can be easily shown that by the end of the run, the
4579 // probability for any candidate is converged to 1/n, thus giving the
4580 // uniform distribution among all the candidates.
4581 //
4582 // We don't care about the domain size as long as (RANDOMIZED_DOMAIN / count) is large.
4583 #define RANDOMIZED_DOMAIN_POW 29
4584 #define RANDOMIZED_DOMAIN (1 << RANDOMIZED_DOMAIN_POW)
4585 #define RANDOMIZED_DOMAIN_MASK ((1 << (RANDOMIZED_DOMAIN_POW + 1)) - 1)
4586 bool Compile::randomized_select(int count) {
4587   assert(count > 0, "only positive");
4588   return (os::random() & RANDOMIZED_DOMAIN_MASK) < (RANDOMIZED_DOMAIN / count);
4589 }
4590 
4591 CloneMap&     Compile::clone_map()                 { return _clone_map; }
4592 void          Compile::set_clone_map(Dict* d)      { _clone_map._dict = d; }
4593 
4594 void NodeCloneInfo::dump() const {
4595   tty->print(" {%d:%d} ", idx(), gen());
4596 }
4597 
4598 void CloneMap::clone(Node* old, Node* nnn, int gen) {
4599   uint64_t val = value(old->_idx);
4600   NodeCloneInfo cio(val);
4601   assert(val != 0, "old node should be in the map");
4602   NodeCloneInfo cin(cio.idx(), gen + cio.gen());
4603   insert(nnn->_idx, cin.get());
4604 #ifndef PRODUCT
4605   if (is_debug()) {
4606     tty->print_cr("CloneMap::clone inserted node %d info {%d:%d} into CloneMap", nnn->_idx, cin.idx(), cin.gen());
4607   }
4608 #endif
4609 }
4610 
4611 void CloneMap::verify_insert_and_clone(Node* old, Node* nnn, int gen) {
4612   NodeCloneInfo cio(value(old->_idx));
4613   if (cio.get() == 0) {
4614     cio.set(old->_idx, 0);
4615     insert(old->_idx, cio.get());
4616 #ifndef PRODUCT
4617     if (is_debug()) {
4618       tty->print_cr("CloneMap::verify_insert_and_clone inserted node %d info {%d:%d} into CloneMap", old->_idx, cio.idx(), cio.gen());
4619     }
4620 #endif
4621   }
4622   clone(old, nnn, gen);
4623 }
4624 
4625 int CloneMap::max_gen() const {
4626   int g = 0;
4627   DictI di(_dict);
4628   for(; di.test(); ++di) {
4629     int t = gen(di._key);
4630     if (g < t) {
4631       g = t;
4632 #ifndef PRODUCT
4633       if (is_debug()) {
4634         tty->print_cr("CloneMap::max_gen() update max=%d from %d", g, _2_node_idx_t(di._key));
4635       }
4636 #endif
4637     }
4638   }
4639   return g;
4640 }
4641 
4642 void CloneMap::dump(node_idx_t key) const {
4643   uint64_t val = value(key);
4644   if (val != 0) {
4645     NodeCloneInfo ni(val);
4646     ni.dump();
4647   }
4648 }