1 /*
   2  * Copyright (c) 1997, 2019, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "asm/macroAssembler.hpp"
  27 #include "asm/macroAssembler.inline.hpp"
  28 #include "ci/ciReplay.hpp"
  29 #include "classfile/systemDictionary.hpp"
  30 #include "code/exceptionHandlerTable.hpp"
  31 #include "code/nmethod.hpp"
  32 #include "compiler/compileBroker.hpp"
  33 #include "compiler/compileLog.hpp"
  34 #include "compiler/disassembler.hpp"
  35 #include "compiler/oopMap.hpp"
  36 #include "gc/shared/barrierSet.hpp"
  37 #include "gc/shared/c2/barrierSetC2.hpp"
  38 #include "memory/resourceArea.hpp"
  39 #include "opto/addnode.hpp"
  40 #include "opto/block.hpp"
  41 #include "opto/c2compiler.hpp"
  42 #include "opto/callGenerator.hpp"
  43 #include "opto/callnode.hpp"
  44 #include "opto/castnode.hpp"
  45 #include "opto/cfgnode.hpp"
  46 #include "opto/chaitin.hpp"
  47 #include "opto/compile.hpp"
  48 #include "opto/connode.hpp"
  49 #include "opto/convertnode.hpp"
  50 #include "opto/divnode.hpp"
  51 #include "opto/escape.hpp"
  52 #include "opto/idealGraphPrinter.hpp"
  53 #include "opto/loopnode.hpp"
  54 #include "opto/machnode.hpp"
  55 #include "opto/macro.hpp"
  56 #include "opto/matcher.hpp"
  57 #include "opto/mathexactnode.hpp"
  58 #include "opto/memnode.hpp"
  59 #include "opto/mulnode.hpp"
  60 #include "opto/narrowptrnode.hpp"
  61 #include "opto/node.hpp"
  62 #include "opto/opcodes.hpp"
  63 #include "opto/output.hpp"
  64 #include "opto/parse.hpp"
  65 #include "opto/phaseX.hpp"
  66 #include "opto/rootnode.hpp"
  67 #include "opto/runtime.hpp"
  68 #include "opto/stringopts.hpp"
  69 #include "opto/type.hpp"
  70 #include "opto/valuetypenode.hpp"
  71 #include "opto/vectornode.hpp"
  72 #include "runtime/arguments.hpp"
  73 #include "runtime/sharedRuntime.hpp"
  74 #include "runtime/signature.hpp"
  75 #include "runtime/stubRoutines.hpp"
  76 #include "runtime/timer.hpp"
  77 #include "utilities/align.hpp"
  78 #include "utilities/copy.hpp"
  79 #include "utilities/macros.hpp"
  80 #if INCLUDE_ZGC
  81 #include "gc/z/c2/zBarrierSetC2.hpp"
  82 #endif
  83 
  84 
  85 // -------------------- Compile::mach_constant_base_node -----------------------
  86 // Constant table base node singleton.
  87 MachConstantBaseNode* Compile::mach_constant_base_node() {
  88   if (_mach_constant_base_node == NULL) {
  89     _mach_constant_base_node = new MachConstantBaseNode();
  90     _mach_constant_base_node->add_req(C->root());
  91   }
  92   return _mach_constant_base_node;
  93 }
  94 
  95 
  96 /// Support for intrinsics.
  97 
  98 // Return the index at which m must be inserted (or already exists).
  99 // The sort order is by the address of the ciMethod, with is_virtual as minor key.
 100 class IntrinsicDescPair {
 101  private:
 102   ciMethod* _m;
 103   bool _is_virtual;
 104  public:
 105   IntrinsicDescPair(ciMethod* m, bool is_virtual) : _m(m), _is_virtual(is_virtual) {}
 106   static int compare(IntrinsicDescPair* const& key, CallGenerator* const& elt) {
 107     ciMethod* m= elt->method();
 108     ciMethod* key_m = key->_m;
 109     if (key_m < m)      return -1;
 110     else if (key_m > m) return 1;
 111     else {
 112       bool is_virtual = elt->is_virtual();
 113       bool key_virtual = key->_is_virtual;
 114       if (key_virtual < is_virtual)      return -1;
 115       else if (key_virtual > is_virtual) return 1;
 116       else                               return 0;
 117     }
 118   }
 119 };
 120 int Compile::intrinsic_insertion_index(ciMethod* m, bool is_virtual, bool& found) {
 121 #ifdef ASSERT
 122   for (int i = 1; i < _intrinsics->length(); i++) {
 123     CallGenerator* cg1 = _intrinsics->at(i-1);
 124     CallGenerator* cg2 = _intrinsics->at(i);
 125     assert(cg1->method() != cg2->method()
 126            ? cg1->method()     < cg2->method()
 127            : cg1->is_virtual() < cg2->is_virtual(),
 128            "compiler intrinsics list must stay sorted");
 129   }
 130 #endif
 131   IntrinsicDescPair pair(m, is_virtual);
 132   return _intrinsics->find_sorted<IntrinsicDescPair*, IntrinsicDescPair::compare>(&pair, found);
 133 }
 134 
 135 void Compile::register_intrinsic(CallGenerator* cg) {
 136   if (_intrinsics == NULL) {
 137     _intrinsics = new (comp_arena())GrowableArray<CallGenerator*>(comp_arena(), 60, 0, NULL);
 138   }
 139   int len = _intrinsics->length();
 140   bool found = false;
 141   int index = intrinsic_insertion_index(cg->method(), cg->is_virtual(), found);
 142   assert(!found, "registering twice");
 143   _intrinsics->insert_before(index, cg);
 144   assert(find_intrinsic(cg->method(), cg->is_virtual()) == cg, "registration worked");
 145 }
 146 
 147 CallGenerator* Compile::find_intrinsic(ciMethod* m, bool is_virtual) {
 148   assert(m->is_loaded(), "don't try this on unloaded methods");
 149   if (_intrinsics != NULL) {
 150     bool found = false;
 151     int index = intrinsic_insertion_index(m, is_virtual, found);
 152      if (found) {
 153       return _intrinsics->at(index);
 154     }
 155   }
 156   // Lazily create intrinsics for intrinsic IDs well-known in the runtime.
 157   if (m->intrinsic_id() != vmIntrinsics::_none &&
 158       m->intrinsic_id() <= vmIntrinsics::LAST_COMPILER_INLINE) {
 159     CallGenerator* cg = make_vm_intrinsic(m, is_virtual);
 160     if (cg != NULL) {
 161       // Save it for next time:
 162       register_intrinsic(cg);
 163       return cg;
 164     } else {
 165       gather_intrinsic_statistics(m->intrinsic_id(), is_virtual, _intrinsic_disabled);
 166     }
 167   }
 168   return NULL;
 169 }
 170 
 171 // Compile:: register_library_intrinsics and make_vm_intrinsic are defined
 172 // in library_call.cpp.
 173 
 174 
 175 #ifndef PRODUCT
 176 // statistics gathering...
 177 
 178 juint  Compile::_intrinsic_hist_count[vmIntrinsics::ID_LIMIT] = {0};
 179 jubyte Compile::_intrinsic_hist_flags[vmIntrinsics::ID_LIMIT] = {0};
 180 
 181 bool Compile::gather_intrinsic_statistics(vmIntrinsics::ID id, bool is_virtual, int flags) {
 182   assert(id > vmIntrinsics::_none && id < vmIntrinsics::ID_LIMIT, "oob");
 183   int oflags = _intrinsic_hist_flags[id];
 184   assert(flags != 0, "what happened?");
 185   if (is_virtual) {
 186     flags |= _intrinsic_virtual;
 187   }
 188   bool changed = (flags != oflags);
 189   if ((flags & _intrinsic_worked) != 0) {
 190     juint count = (_intrinsic_hist_count[id] += 1);
 191     if (count == 1) {
 192       changed = true;           // first time
 193     }
 194     // increment the overall count also:
 195     _intrinsic_hist_count[vmIntrinsics::_none] += 1;
 196   }
 197   if (changed) {
 198     if (((oflags ^ flags) & _intrinsic_virtual) != 0) {
 199       // Something changed about the intrinsic's virtuality.
 200       if ((flags & _intrinsic_virtual) != 0) {
 201         // This is the first use of this intrinsic as a virtual call.
 202         if (oflags != 0) {
 203           // We already saw it as a non-virtual, so note both cases.
 204           flags |= _intrinsic_both;
 205         }
 206       } else if ((oflags & _intrinsic_both) == 0) {
 207         // This is the first use of this intrinsic as a non-virtual
 208         flags |= _intrinsic_both;
 209       }
 210     }
 211     _intrinsic_hist_flags[id] = (jubyte) (oflags | flags);
 212   }
 213   // update the overall flags also:
 214   _intrinsic_hist_flags[vmIntrinsics::_none] |= (jubyte) flags;
 215   return changed;
 216 }
 217 
 218 static char* format_flags(int flags, char* buf) {
 219   buf[0] = 0;
 220   if ((flags & Compile::_intrinsic_worked) != 0)    strcat(buf, ",worked");
 221   if ((flags & Compile::_intrinsic_failed) != 0)    strcat(buf, ",failed");
 222   if ((flags & Compile::_intrinsic_disabled) != 0)  strcat(buf, ",disabled");
 223   if ((flags & Compile::_intrinsic_virtual) != 0)   strcat(buf, ",virtual");
 224   if ((flags & Compile::_intrinsic_both) != 0)      strcat(buf, ",nonvirtual");
 225   if (buf[0] == 0)  strcat(buf, ",");
 226   assert(buf[0] == ',', "must be");
 227   return &buf[1];
 228 }
 229 
 230 void Compile::print_intrinsic_statistics() {
 231   char flagsbuf[100];
 232   ttyLocker ttyl;
 233   if (xtty != NULL)  xtty->head("statistics type='intrinsic'");
 234   tty->print_cr("Compiler intrinsic usage:");
 235   juint total = _intrinsic_hist_count[vmIntrinsics::_none];
 236   if (total == 0)  total = 1;  // avoid div0 in case of no successes
 237   #define PRINT_STAT_LINE(name, c, f) \
 238     tty->print_cr("  %4d (%4.1f%%) %s (%s)", (int)(c), ((c) * 100.0) / total, name, f);
 239   for (int index = 1 + (int)vmIntrinsics::_none; index < (int)vmIntrinsics::ID_LIMIT; index++) {
 240     vmIntrinsics::ID id = (vmIntrinsics::ID) index;
 241     int   flags = _intrinsic_hist_flags[id];
 242     juint count = _intrinsic_hist_count[id];
 243     if ((flags | count) != 0) {
 244       PRINT_STAT_LINE(vmIntrinsics::name_at(id), count, format_flags(flags, flagsbuf));
 245     }
 246   }
 247   PRINT_STAT_LINE("total", total, format_flags(_intrinsic_hist_flags[vmIntrinsics::_none], flagsbuf));
 248   if (xtty != NULL)  xtty->tail("statistics");
 249 }
 250 
 251 void Compile::print_statistics() {
 252   { ttyLocker ttyl;
 253     if (xtty != NULL)  xtty->head("statistics type='opto'");
 254     Parse::print_statistics();
 255     PhaseCCP::print_statistics();
 256     PhaseRegAlloc::print_statistics();
 257     Scheduling::print_statistics();
 258     PhasePeephole::print_statistics();
 259     PhaseIdealLoop::print_statistics();
 260     if (xtty != NULL)  xtty->tail("statistics");
 261   }
 262   if (_intrinsic_hist_flags[vmIntrinsics::_none] != 0) {
 263     // put this under its own <statistics> element.
 264     print_intrinsic_statistics();
 265   }
 266 }
 267 #endif //PRODUCT
 268 
 269 // Support for bundling info
 270 Bundle* Compile::node_bundling(const Node *n) {
 271   assert(valid_bundle_info(n), "oob");
 272   return &_node_bundling_base[n->_idx];
 273 }
 274 
 275 bool Compile::valid_bundle_info(const Node *n) {
 276   return (_node_bundling_limit > n->_idx);
 277 }
 278 
 279 
 280 void Compile::gvn_replace_by(Node* n, Node* nn) {
 281   for (DUIterator_Last imin, i = n->last_outs(imin); i >= imin; ) {
 282     Node* use = n->last_out(i);
 283     bool is_in_table = initial_gvn()->hash_delete(use);
 284     uint uses_found = 0;
 285     for (uint j = 0; j < use->len(); j++) {
 286       if (use->in(j) == n) {
 287         if (j < use->req())
 288           use->set_req(j, nn);
 289         else
 290           use->set_prec(j, nn);
 291         uses_found++;
 292       }
 293     }
 294     if (is_in_table) {
 295       // reinsert into table
 296       initial_gvn()->hash_find_insert(use);
 297     }
 298     record_for_igvn(use);
 299     i -= uses_found;    // we deleted 1 or more copies of this edge
 300   }
 301 }
 302 
 303 
 304 static inline bool not_a_node(const Node* n) {
 305   if (n == NULL)                   return true;
 306   if (((intptr_t)n & 1) != 0)      return true;  // uninitialized, etc.
 307   if (*(address*)n == badAddress)  return true;  // kill by Node::destruct
 308   return false;
 309 }
 310 
 311 // Identify all nodes that are reachable from below, useful.
 312 // Use breadth-first pass that records state in a Unique_Node_List,
 313 // recursive traversal is slower.
 314 void Compile::identify_useful_nodes(Unique_Node_List &useful) {
 315   int estimated_worklist_size = live_nodes();
 316   useful.map( estimated_worklist_size, NULL );  // preallocate space
 317 
 318   // Initialize worklist
 319   if (root() != NULL)     { useful.push(root()); }
 320   // If 'top' is cached, declare it useful to preserve cached node
 321   if( cached_top_node() ) { useful.push(cached_top_node()); }
 322 
 323   // Push all useful nodes onto the list, breadthfirst
 324   for( uint next = 0; next < useful.size(); ++next ) {
 325     assert( next < unique(), "Unique useful nodes < total nodes");
 326     Node *n  = useful.at(next);
 327     uint max = n->len();
 328     for( uint i = 0; i < max; ++i ) {
 329       Node *m = n->in(i);
 330       if (not_a_node(m))  continue;
 331       useful.push(m);
 332     }
 333   }
 334 }
 335 
 336 // Update dead_node_list with any missing dead nodes using useful
 337 // list. Consider all non-useful nodes to be useless i.e., dead nodes.
 338 void Compile::update_dead_node_list(Unique_Node_List &useful) {
 339   uint max_idx = unique();
 340   VectorSet& useful_node_set = useful.member_set();
 341 
 342   for (uint node_idx = 0; node_idx < max_idx; node_idx++) {
 343     // If node with index node_idx is not in useful set,
 344     // mark it as dead in dead node list.
 345     if (! useful_node_set.test(node_idx) ) {
 346       record_dead_node(node_idx);
 347     }
 348   }
 349 }
 350 
 351 void Compile::remove_useless_late_inlines(GrowableArray<CallGenerator*>* inlines, Unique_Node_List &useful) {
 352   int shift = 0;
 353   for (int i = 0; i < inlines->length(); i++) {
 354     CallGenerator* cg = inlines->at(i);
 355     CallNode* call = cg->call_node();
 356     if (shift > 0) {
 357       inlines->at_put(i-shift, cg);
 358     }
 359     if (!useful.member(call)) {
 360       shift++;
 361     }
 362   }
 363   inlines->trunc_to(inlines->length()-shift);
 364 }
 365 
 366 // Disconnect all useless nodes by disconnecting those at the boundary.
 367 void Compile::remove_useless_nodes(Unique_Node_List &useful) {
 368   uint next = 0;
 369   while (next < useful.size()) {
 370     Node *n = useful.at(next++);
 371     if (n->is_SafePoint()) {
 372       // We're done with a parsing phase. Replaced nodes are not valid
 373       // beyond that point.
 374       n->as_SafePoint()->delete_replaced_nodes();
 375     }
 376     // Use raw traversal of out edges since this code removes out edges
 377     int max = n->outcnt();
 378     for (int j = 0; j < max; ++j) {
 379       Node* child = n->raw_out(j);
 380       if (! useful.member(child)) {
 381         assert(!child->is_top() || child != top(),
 382                "If top is cached in Compile object it is in useful list");
 383         // Only need to remove this out-edge to the useless node
 384         n->raw_del_out(j);
 385         --j;
 386         --max;
 387       }
 388     }
 389     if (n->outcnt() == 1 && n->has_special_unique_user()) {
 390       record_for_igvn(n->unique_out());
 391     }
 392   }
 393   // Remove useless macro and predicate opaq nodes
 394   for (int i = C->macro_count()-1; i >= 0; i--) {
 395     Node* n = C->macro_node(i);
 396     if (!useful.member(n)) {
 397       remove_macro_node(n);
 398     }
 399   }
 400   // Remove useless CastII nodes with range check dependency
 401   for (int i = range_check_cast_count() - 1; i >= 0; i--) {
 402     Node* cast = range_check_cast_node(i);
 403     if (!useful.member(cast)) {
 404       remove_range_check_cast(cast);
 405     }
 406   }
 407   // Remove useless expensive nodes
 408   for (int i = C->expensive_count()-1; i >= 0; i--) {
 409     Node* n = C->expensive_node(i);
 410     if (!useful.member(n)) {
 411       remove_expensive_node(n);
 412     }
 413   }
 414   // Remove useless Opaque4 nodes
 415   for (int i = opaque4_count() - 1; i >= 0; i--) {
 416     Node* opaq = opaque4_node(i);
 417     if (!useful.member(opaq)) {
 418       remove_opaque4_node(opaq);
 419     }
 420   }
 421   // Remove useless value type nodes
 422   if (_value_type_nodes != NULL) {
 423     _value_type_nodes->remove_useless_nodes(useful.member_set());
 424   }
 425   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 426   bs->eliminate_useless_gc_barriers(useful, this);
 427   // clean up the late inline lists
 428   remove_useless_late_inlines(&_string_late_inlines, useful);
 429   remove_useless_late_inlines(&_boxing_late_inlines, useful);
 430   remove_useless_late_inlines(&_late_inlines, useful);
 431   debug_only(verify_graph_edges(true/*check for no_dead_code*/);)
 432 }
 433 
 434 //------------------------------frame_size_in_words-----------------------------
 435 // frame_slots in units of words
 436 int Compile::frame_size_in_words() const {
 437   // shift is 0 in LP32 and 1 in LP64
 438   const int shift = (LogBytesPerWord - LogBytesPerInt);
 439   int words = _frame_slots >> shift;
 440   assert( words << shift == _frame_slots, "frame size must be properly aligned in LP64" );
 441   return words;
 442 }
 443 
 444 // To bang the stack of this compiled method we use the stack size
 445 // that the interpreter would need in case of a deoptimization. This
 446 // removes the need to bang the stack in the deoptimization blob which
 447 // in turn simplifies stack overflow handling.
 448 int Compile::bang_size_in_bytes() const {
 449   return MAX2(frame_size_in_bytes() + os::extra_bang_size_in_bytes(), _interpreter_frame_size);
 450 }
 451 
 452 // ============================================================================
 453 //------------------------------CompileWrapper---------------------------------
 454 class CompileWrapper : public StackObj {
 455   Compile *const _compile;
 456  public:
 457   CompileWrapper(Compile* compile);
 458 
 459   ~CompileWrapper();
 460 };
 461 
 462 CompileWrapper::CompileWrapper(Compile* compile) : _compile(compile) {
 463   // the Compile* pointer is stored in the current ciEnv:
 464   ciEnv* env = compile->env();
 465   assert(env == ciEnv::current(), "must already be a ciEnv active");
 466   assert(env->compiler_data() == NULL, "compile already active?");
 467   env->set_compiler_data(compile);
 468   assert(compile == Compile::current(), "sanity");
 469 
 470   compile->set_type_dict(NULL);
 471   compile->set_clone_map(new Dict(cmpkey, hashkey, _compile->comp_arena()));
 472   compile->clone_map().set_clone_idx(0);
 473   compile->set_type_last_size(0);
 474   compile->set_last_tf(NULL, NULL);
 475   compile->set_indexSet_arena(NULL);
 476   compile->set_indexSet_free_block_list(NULL);
 477   compile->init_type_arena();
 478   Type::Initialize(compile);
 479   _compile->set_scratch_buffer_blob(NULL);
 480   _compile->begin_method();
 481   _compile->clone_map().set_debug(_compile->has_method() && _compile->directive()->CloneMapDebugOption);
 482 }
 483 CompileWrapper::~CompileWrapper() {
 484   _compile->end_method();
 485   if (_compile->scratch_buffer_blob() != NULL)
 486     BufferBlob::free(_compile->scratch_buffer_blob());
 487   _compile->env()->set_compiler_data(NULL);
 488 }
 489 
 490 
 491 //----------------------------print_compile_messages---------------------------
 492 void Compile::print_compile_messages() {
 493 #ifndef PRODUCT
 494   // Check if recompiling
 495   if (_subsume_loads == false && PrintOpto) {
 496     // Recompiling without allowing machine instructions to subsume loads
 497     tty->print_cr("*********************************************************");
 498     tty->print_cr("** Bailout: Recompile without subsuming loads          **");
 499     tty->print_cr("*********************************************************");
 500   }
 501   if (_do_escape_analysis != DoEscapeAnalysis && PrintOpto) {
 502     // Recompiling without escape analysis
 503     tty->print_cr("*********************************************************");
 504     tty->print_cr("** Bailout: Recompile without escape analysis          **");
 505     tty->print_cr("*********************************************************");
 506   }
 507   if (_eliminate_boxing != EliminateAutoBox && PrintOpto) {
 508     // Recompiling without boxing elimination
 509     tty->print_cr("*********************************************************");
 510     tty->print_cr("** Bailout: Recompile without boxing elimination       **");
 511     tty->print_cr("*********************************************************");
 512   }
 513   if (C->directive()->BreakAtCompileOption) {
 514     // Open the debugger when compiling this method.
 515     tty->print("### Breaking when compiling: ");
 516     method()->print_short_name();
 517     tty->cr();
 518     BREAKPOINT;
 519   }
 520 
 521   if( PrintOpto ) {
 522     if (is_osr_compilation()) {
 523       tty->print("[OSR]%3d", _compile_id);
 524     } else {
 525       tty->print("%3d", _compile_id);
 526     }
 527   }
 528 #endif
 529 }
 530 
 531 
 532 //-----------------------init_scratch_buffer_blob------------------------------
 533 // Construct a temporary BufferBlob and cache it for this compile.
 534 void Compile::init_scratch_buffer_blob(int const_size) {
 535   // If there is already a scratch buffer blob allocated and the
 536   // constant section is big enough, use it.  Otherwise free the
 537   // current and allocate a new one.
 538   BufferBlob* blob = scratch_buffer_blob();
 539   if ((blob != NULL) && (const_size <= _scratch_const_size)) {
 540     // Use the current blob.
 541   } else {
 542     if (blob != NULL) {
 543       BufferBlob::free(blob);
 544     }
 545 
 546     ResourceMark rm;
 547     _scratch_const_size = const_size;
 548     int size = C2Compiler::initial_code_buffer_size(const_size);
 549 #ifdef ASSERT
 550     if (C->has_scalarized_args()) {
 551       // Oop verification for loading object fields from scalarized value types in the new entry point requires lots of space
 552       size += 5120;
 553     }
 554 #endif
 555     blob = BufferBlob::create("Compile::scratch_buffer", size);
 556     // Record the buffer blob for next time.
 557     set_scratch_buffer_blob(blob);
 558     // Have we run out of code space?
 559     if (scratch_buffer_blob() == NULL) {
 560       // Let CompilerBroker disable further compilations.
 561       record_failure("Not enough space for scratch buffer in CodeCache");
 562       return;
 563     }
 564   }
 565 
 566   // Initialize the relocation buffers
 567   relocInfo* locs_buf = (relocInfo*) blob->content_end() - MAX_locs_size;
 568   set_scratch_locs_memory(locs_buf);
 569 }
 570 
 571 
 572 //-----------------------scratch_emit_size-------------------------------------
 573 // Helper function that computes size by emitting code
 574 uint Compile::scratch_emit_size(const Node* n) {
 575   // Start scratch_emit_size section.
 576   set_in_scratch_emit_size(true);
 577 
 578   // Emit into a trash buffer and count bytes emitted.
 579   // This is a pretty expensive way to compute a size,
 580   // but it works well enough if seldom used.
 581   // All common fixed-size instructions are given a size
 582   // method by the AD file.
 583   // Note that the scratch buffer blob and locs memory are
 584   // allocated at the beginning of the compile task, and
 585   // may be shared by several calls to scratch_emit_size.
 586   // The allocation of the scratch buffer blob is particularly
 587   // expensive, since it has to grab the code cache lock.
 588   BufferBlob* blob = this->scratch_buffer_blob();
 589   assert(blob != NULL, "Initialize BufferBlob at start");
 590   assert(blob->size() > MAX_inst_size, "sanity");
 591   relocInfo* locs_buf = scratch_locs_memory();
 592   address blob_begin = blob->content_begin();
 593   address blob_end   = (address)locs_buf;
 594   assert(blob->contains(blob_end), "sanity");
 595   CodeBuffer buf(blob_begin, blob_end - blob_begin);
 596   buf.initialize_consts_size(_scratch_const_size);
 597   buf.initialize_stubs_size(MAX_stubs_size);
 598   assert(locs_buf != NULL, "sanity");
 599   int lsize = MAX_locs_size / 3;
 600   buf.consts()->initialize_shared_locs(&locs_buf[lsize * 0], lsize);
 601   buf.insts()->initialize_shared_locs( &locs_buf[lsize * 1], lsize);
 602   buf.stubs()->initialize_shared_locs( &locs_buf[lsize * 2], lsize);
 603   // Mark as scratch buffer.
 604   buf.consts()->set_scratch_emit();
 605   buf.insts()->set_scratch_emit();
 606   buf.stubs()->set_scratch_emit();
 607 
 608   // Do the emission.
 609 
 610   Label fakeL; // Fake label for branch instructions.
 611   Label*   saveL = NULL;
 612   uint save_bnum = 0;
 613   bool is_branch = n->is_MachBranch();
 614   if (is_branch) {
 615     MacroAssembler masm(&buf);
 616     masm.bind(fakeL);
 617     n->as_MachBranch()->save_label(&saveL, &save_bnum);
 618     n->as_MachBranch()->label_set(&fakeL, 0);
 619   } else if (n->is_MachProlog()) {
 620     saveL = ((MachPrologNode*)n)->_verified_entry;
 621     ((MachPrologNode*)n)->_verified_entry = &fakeL;
 622   }
 623   n->emit(buf, this->regalloc());
 624 
 625   // Emitting into the scratch buffer should not fail
 626   assert (!failing(), "Must not have pending failure. Reason is: %s", failure_reason());
 627 
 628   // Restore label.
 629   if (is_branch) {
 630     n->as_MachBranch()->label_set(saveL, save_bnum);
 631   } else if (n->is_MachProlog()) {
 632     ((MachPrologNode*)n)->_verified_entry = saveL;
 633   }
 634 
 635   // End scratch_emit_size section.
 636   set_in_scratch_emit_size(false);
 637 
 638   return buf.insts_size();
 639 }
 640 
 641 
 642 // ============================================================================
 643 //------------------------------Compile standard-------------------------------
 644 debug_only( int Compile::_debug_idx = 100000; )
 645 
 646 // Compile a method.  entry_bci is -1 for normal compilations and indicates
 647 // the continuation bci for on stack replacement.
 648 
 649 
 650 Compile::Compile( ciEnv* ci_env, C2Compiler* compiler, ciMethod* target, int osr_bci,
 651                   bool subsume_loads, bool do_escape_analysis, bool eliminate_boxing, DirectiveSet* directive)
 652                 : Phase(Compiler),
 653                   _compile_id(ci_env->compile_id()),
 654                   _save_argument_registers(false),
 655                   _subsume_loads(subsume_loads),
 656                   _do_escape_analysis(do_escape_analysis),
 657                   _eliminate_boxing(eliminate_boxing),
 658                   _method(target),
 659                   _entry_bci(osr_bci),
 660                   _stub_function(NULL),
 661                   _stub_name(NULL),
 662                   _stub_entry_point(NULL),
 663                   _max_node_limit(MaxNodeLimit),
 664                   _orig_pc_slot(0),
 665                   _orig_pc_slot_offset_in_bytes(0),
 666                   _sp_inc_slot(0),
 667                   _sp_inc_slot_offset_in_bytes(0),
 668                   _inlining_progress(false),
 669                   _inlining_incrementally(false),
 670                   _do_cleanup(false),
 671                   _has_reserved_stack_access(target->has_reserved_stack_access()),
 672 #ifndef PRODUCT
 673                   _trace_opto_output(directive->TraceOptoOutputOption),
 674 #endif
 675                   _has_method_handle_invokes(false),
 676                   _clinit_barrier_on_entry(false),
 677                   _comp_arena(mtCompiler),
 678                   _barrier_set_state(BarrierSet::barrier_set()->barrier_set_c2()->create_barrier_state(comp_arena())),
 679                   _env(ci_env),
 680                   _directive(directive),
 681                   _log(ci_env->log()),
 682                   _failure_reason(NULL),
 683                   _congraph(NULL),
 684 #ifndef PRODUCT
 685                   _printer(IdealGraphPrinter::printer()),
 686 #endif
 687                   _dead_node_list(comp_arena()),
 688                   _dead_node_count(0),
 689                   _node_arena(mtCompiler),
 690                   _old_arena(mtCompiler),
 691                   _mach_constant_base_node(NULL),
 692                   _Compile_types(mtCompiler),
 693                   _initial_gvn(NULL),
 694                   _for_igvn(NULL),
 695                   _warm_calls(NULL),
 696                   _late_inlines(comp_arena(), 2, 0, NULL),
 697                   _string_late_inlines(comp_arena(), 2, 0, NULL),
 698                   _boxing_late_inlines(comp_arena(), 2, 0, NULL),
 699                   _late_inlines_pos(0),
 700                   _number_of_mh_late_inlines(0),
 701                   _print_inlining_stream(NULL),
 702                   _print_inlining_list(NULL),
 703                   _print_inlining_idx(0),
 704                   _print_inlining_output(NULL),
 705                   _replay_inline_data(NULL),
 706                   _java_calls(0),
 707                   _inner_loops(0),
 708                   _interpreter_frame_size(0),
 709                   _node_bundling_limit(0),
 710                   _node_bundling_base(NULL),
 711                   _code_buffer("Compile::Fill_buffer"),
 712                   _scratch_const_size(-1),
 713                   _in_scratch_emit_size(false)
 714 #ifndef PRODUCT
 715                   , _in_dump_cnt(0)
 716 #endif
 717 {
 718   C = this;
 719 #ifndef PRODUCT
 720   if (_printer != NULL) {
 721     _printer->set_compile(this);
 722   }
 723 #endif
 724   CompileWrapper cw(this);
 725 
 726   if (CITimeVerbose) {
 727     tty->print(" ");
 728     target->holder()->name()->print();
 729     tty->print(".");
 730     target->print_short_name();
 731     tty->print("  ");
 732   }
 733   TraceTime t1("Total compilation time", &_t_totalCompilation, CITime, CITimeVerbose);
 734   TraceTime t2(NULL, &_t_methodCompilation, CITime, false);
 735 
 736 #if defined(SUPPORT_ASSEMBLY) || defined(SUPPORT_ABSTRACT_ASSEMBLY)
 737   bool print_opto_assembly = directive->PrintOptoAssemblyOption;
 738   // We can always print a disassembly, either abstract (hex dump) or
 739   // with the help of a suitable hsdis library. Thus, we should not
 740   // couple print_assembly and print_opto_assembly controls.
 741   // But: always print opto and regular assembly on compile command 'print'.
 742   bool print_assembly = directive->PrintAssemblyOption;
 743   set_print_assembly(print_opto_assembly || print_assembly);
 744 #else
 745   set_print_assembly(false); // must initialize.
 746 #endif
 747 
 748 #ifndef PRODUCT
 749   set_parsed_irreducible_loop(false);
 750 
 751   if (directive->ReplayInlineOption) {
 752     _replay_inline_data = ciReplay::load_inline_data(method(), entry_bci(), ci_env->comp_level());
 753   }
 754 #endif
 755   set_print_inlining(directive->PrintInliningOption || PrintOptoInlining);
 756   set_print_intrinsics(directive->PrintIntrinsicsOption);
 757   set_has_irreducible_loop(true); // conservative until build_loop_tree() reset it
 758 
 759   if (ProfileTraps RTM_OPT_ONLY( || UseRTMLocking )) {
 760     // Make sure the method being compiled gets its own MDO,
 761     // so we can at least track the decompile_count().
 762     // Need MDO to record RTM code generation state.
 763     method()->ensure_method_data();
 764   }
 765 
 766   Init(::AliasLevel);
 767 
 768 
 769   print_compile_messages();
 770 
 771   _ilt = InlineTree::build_inline_tree_root();
 772 
 773   // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
 774   assert(num_alias_types() >= AliasIdxRaw, "");
 775 
 776 #define MINIMUM_NODE_HASH  1023
 777   // Node list that Iterative GVN will start with
 778   Unique_Node_List for_igvn(comp_arena());
 779   set_for_igvn(&for_igvn);
 780 
 781   // GVN that will be run immediately on new nodes
 782   uint estimated_size = method()->code_size()*4+64;
 783   estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
 784   PhaseGVN gvn(node_arena(), estimated_size);
 785   set_initial_gvn(&gvn);
 786 
 787   print_inlining_init();
 788   { // Scope for timing the parser
 789     TracePhase tp("parse", &timers[_t_parser]);
 790 
 791     // Put top into the hash table ASAP.
 792     initial_gvn()->transform_no_reclaim(top());
 793 
 794     // Set up tf(), start(), and find a CallGenerator.
 795     CallGenerator* cg = NULL;
 796     if (is_osr_compilation()) {
 797       const TypeTuple *domain = StartOSRNode::osr_domain();
 798       const TypeTuple *range = TypeTuple::make_range(method()->signature());
 799       init_tf(TypeFunc::make(domain, range));
 800       StartNode* s = new StartOSRNode(root(), domain);
 801       initial_gvn()->set_type_bottom(s);
 802       init_start(s);
 803       cg = CallGenerator::for_osr(method(), entry_bci());
 804     } else {
 805       // Normal case.
 806       init_tf(TypeFunc::make(method()));
 807       StartNode* s = new StartNode(root(), tf()->domain_cc());
 808       initial_gvn()->set_type_bottom(s);
 809       init_start(s);
 810       if (method()->intrinsic_id() == vmIntrinsics::_Reference_get) {
 811         // With java.lang.ref.reference.get() we must go through the
 812         // intrinsic - even when get() is the root
 813         // method of the compile - so that, if necessary, the value in
 814         // the referent field of the reference object gets recorded by
 815         // the pre-barrier code.
 816         cg = find_intrinsic(method(), false);
 817       }
 818       if (cg == NULL) {
 819         float past_uses = method()->interpreter_invocation_count();
 820         float expected_uses = past_uses;
 821         cg = CallGenerator::for_inline(method(), expected_uses);
 822       }
 823     }
 824     if (failing())  return;
 825     if (cg == NULL) {
 826       record_method_not_compilable("cannot parse method");
 827       return;
 828     }
 829     JVMState* jvms = build_start_state(start(), tf());
 830     if ((jvms = cg->generate(jvms)) == NULL) {
 831       if (!failure_reason_is(C2Compiler::retry_class_loading_during_parsing())) {
 832         record_method_not_compilable("method parse failed");
 833       }
 834       return;
 835     }
 836     GraphKit kit(jvms);
 837 
 838     if (!kit.stopped()) {
 839       // Accept return values, and transfer control we know not where.
 840       // This is done by a special, unique ReturnNode bound to root.
 841       return_values(kit.jvms());
 842     }
 843 
 844     if (kit.has_exceptions()) {
 845       // Any exceptions that escape from this call must be rethrown
 846       // to whatever caller is dynamically above us on the stack.
 847       // This is done by a special, unique RethrowNode bound to root.
 848       rethrow_exceptions(kit.transfer_exceptions_into_jvms());
 849     }
 850 
 851     assert(IncrementalInline || (_late_inlines.length() == 0 && !has_mh_late_inlines()), "incremental inlining is off");
 852 
 853     if (_late_inlines.length() == 0 && !has_mh_late_inlines() && !failing() && has_stringbuilder()) {
 854       inline_string_calls(true);
 855     }
 856 
 857     if (failing())  return;
 858 
 859     print_method(PHASE_BEFORE_REMOVEUSELESS, 3);
 860 
 861     // Remove clutter produced by parsing.
 862     if (!failing()) {
 863       ResourceMark rm;
 864       PhaseRemoveUseless pru(initial_gvn(), &for_igvn);
 865     }
 866   }
 867 
 868   // Note:  Large methods are capped off in do_one_bytecode().
 869   if (failing())  return;
 870 
 871   // After parsing, node notes are no longer automagic.
 872   // They must be propagated by register_new_node_with_optimizer(),
 873   // clone(), or the like.
 874   set_default_node_notes(NULL);
 875 
 876   for (;;) {
 877     int successes = Inline_Warm();
 878     if (failing())  return;
 879     if (successes == 0)  break;
 880   }
 881 
 882   // Drain the list.
 883   Finish_Warm();
 884 #ifndef PRODUCT
 885   if (_printer && _printer->should_print(1)) {
 886     _printer->print_inlining();
 887   }
 888 #endif
 889 
 890   if (failing())  return;
 891   NOT_PRODUCT( verify_graph_edges(); )
 892 
 893   // Now optimize
 894   Optimize();
 895   if (failing())  return;
 896   NOT_PRODUCT( verify_graph_edges(); )
 897 
 898 #ifndef PRODUCT
 899   if (PrintIdeal) {
 900     ttyLocker ttyl;  // keep the following output all in one block
 901     // This output goes directly to the tty, not the compiler log.
 902     // To enable tools to match it up with the compilation activity,
 903     // be sure to tag this tty output with the compile ID.
 904     if (xtty != NULL) {
 905       xtty->head("ideal compile_id='%d'%s", compile_id(),
 906                  is_osr_compilation()    ? " compile_kind='osr'" :
 907                  "");
 908     }
 909     root()->dump(9999);
 910     if (xtty != NULL) {
 911       xtty->tail("ideal");
 912     }
 913   }
 914 #endif
 915 
 916 #ifdef ASSERT
 917   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 918   bs->verify_gc_barriers(this, BarrierSetC2::BeforeCodeGen);
 919 #endif
 920 
 921   // Dump compilation data to replay it.
 922   if (directive->DumpReplayOption) {
 923     env()->dump_replay_data(_compile_id);
 924   }
 925   if (directive->DumpInlineOption && (ilt() != NULL)) {
 926     env()->dump_inline_data(_compile_id);
 927   }
 928 
 929   // Now that we know the size of all the monitors we can add a fixed slot
 930   // for the original deopt pc.
 931 
 932   _orig_pc_slot = fixed_slots();
 933   int next_slot = _orig_pc_slot + (sizeof(address) / VMRegImpl::stack_slot_size);
 934 
 935   if (needs_stack_repair()) {
 936     // One extra slot for the special stack increment value
 937     _sp_inc_slot = next_slot;
 938     next_slot += 2;
 939   }
 940 
 941   set_fixed_slots(next_slot);
 942 
 943   // Compute when to use implicit null checks. Used by matching trap based
 944   // nodes and NullCheck optimization.
 945   set_allowed_deopt_reasons();
 946 
 947   // Now generate code
 948   Code_Gen();
 949   if (failing())  return;
 950 
 951   // Check if we want to skip execution of all compiled code.
 952   {
 953 #ifndef PRODUCT
 954     if (OptoNoExecute) {
 955       record_method_not_compilable("+OptoNoExecute");  // Flag as failed
 956       return;
 957     }
 958 #endif
 959     TracePhase tp("install_code", &timers[_t_registerMethod]);
 960 
 961     if (is_osr_compilation()) {
 962       _code_offsets.set_value(CodeOffsets::Verified_Entry, 0);
 963       _code_offsets.set_value(CodeOffsets::OSR_Entry, _first_block_size);
 964     } else {
 965       _code_offsets.set_value(CodeOffsets::Verified_Entry, _first_block_size);
 966       if (_code_offsets.value(CodeOffsets::Verified_Value_Entry) == -1) {
 967         _code_offsets.set_value(CodeOffsets::Verified_Value_Entry, _first_block_size);
 968       }
 969       if (_code_offsets.value(CodeOffsets::Verified_Value_Entry_RO) == -1) {
 970         _code_offsets.set_value(CodeOffsets::Verified_Value_Entry_RO, _first_block_size);
 971       }
 972       if (_code_offsets.value(CodeOffsets::Entry) == -1) {
 973         _code_offsets.set_value(CodeOffsets::Entry, _first_block_size);
 974       }
 975       _code_offsets.set_value(CodeOffsets::OSR_Entry, 0);
 976     }
 977 
 978     env()->register_method(_method, _entry_bci,
 979                            &_code_offsets,
 980                            _orig_pc_slot_offset_in_bytes,
 981                            code_buffer(),
 982                            frame_size_in_words(), _oop_map_set,
 983                            &_handler_table, &_inc_table,
 984                            compiler,
 985                            has_unsafe_access(),
 986                            SharedRuntime::is_wide_vector(max_vector_size()),
 987                            rtm_state()
 988                            );
 989 
 990     if (log() != NULL) // Print code cache state into compiler log
 991       log()->code_cache_state();
 992   }
 993 }
 994 
 995 //------------------------------Compile----------------------------------------
 996 // Compile a runtime stub
 997 Compile::Compile( ciEnv* ci_env,
 998                   TypeFunc_generator generator,
 999                   address stub_function,
1000                   const char *stub_name,
1001                   int is_fancy_jump,
1002                   bool pass_tls,
1003                   bool save_arg_registers,
1004                   bool return_pc,
1005                   DirectiveSet* directive)
1006   : Phase(Compiler),
1007     _compile_id(0),
1008     _save_argument_registers(save_arg_registers),
1009     _subsume_loads(true),
1010     _do_escape_analysis(false),
1011     _eliminate_boxing(false),
1012     _method(NULL),
1013     _entry_bci(InvocationEntryBci),
1014     _stub_function(stub_function),
1015     _stub_name(stub_name),
1016     _stub_entry_point(NULL),
1017     _max_node_limit(MaxNodeLimit),
1018     _orig_pc_slot(0),
1019     _orig_pc_slot_offset_in_bytes(0),
1020     _sp_inc_slot(0),
1021     _sp_inc_slot_offset_in_bytes(0),
1022     _inlining_progress(false),
1023     _inlining_incrementally(false),
1024     _has_reserved_stack_access(false),
1025 #ifndef PRODUCT
1026     _trace_opto_output(directive->TraceOptoOutputOption),
1027 #endif
1028     _has_method_handle_invokes(false),
1029     _clinit_barrier_on_entry(false),
1030     _comp_arena(mtCompiler),
1031     _env(ci_env),
1032     _directive(directive),
1033     _log(ci_env->log()),
1034     _failure_reason(NULL),
1035     _congraph(NULL),
1036 #ifndef PRODUCT
1037     _printer(NULL),
1038 #endif
1039     _dead_node_list(comp_arena()),
1040     _dead_node_count(0),
1041     _node_arena(mtCompiler),
1042     _old_arena(mtCompiler),
1043     _mach_constant_base_node(NULL),
1044     _Compile_types(mtCompiler),
1045     _initial_gvn(NULL),
1046     _for_igvn(NULL),
1047     _warm_calls(NULL),
1048     _number_of_mh_late_inlines(0),
1049     _print_inlining_stream(NULL),
1050     _print_inlining_list(NULL),
1051     _print_inlining_idx(0),
1052     _print_inlining_output(NULL),
1053     _replay_inline_data(NULL),
1054     _java_calls(0),
1055     _inner_loops(0),
1056     _interpreter_frame_size(0),
1057     _node_bundling_limit(0),
1058     _node_bundling_base(NULL),
1059     _code_buffer("Compile::Fill_buffer"),
1060 #ifndef PRODUCT
1061     _in_dump_cnt(0),
1062 #endif
1063     _allowed_reasons(0) {
1064   C = this;
1065 
1066   TraceTime t1(NULL, &_t_totalCompilation, CITime, false);
1067   TraceTime t2(NULL, &_t_stubCompilation, CITime, false);
1068 
1069 #ifndef PRODUCT
1070   set_print_assembly(PrintFrameConverterAssembly);
1071   set_parsed_irreducible_loop(false);
1072 #else
1073   set_print_assembly(false); // Must initialize.
1074 #endif
1075   set_has_irreducible_loop(false); // no loops
1076 
1077   CompileWrapper cw(this);
1078   Init(/*AliasLevel=*/ 0);
1079   init_tf((*generator)());
1080 
1081   {
1082     // The following is a dummy for the sake of GraphKit::gen_stub
1083     Unique_Node_List for_igvn(comp_arena());
1084     set_for_igvn(&for_igvn);  // not used, but some GraphKit guys push on this
1085     PhaseGVN gvn(Thread::current()->resource_area(),255);
1086     set_initial_gvn(&gvn);    // not significant, but GraphKit guys use it pervasively
1087     gvn.transform_no_reclaim(top());
1088 
1089     GraphKit kit;
1090     kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
1091   }
1092 
1093   NOT_PRODUCT( verify_graph_edges(); )
1094   Code_Gen();
1095   if (failing())  return;
1096 
1097 
1098   // Entry point will be accessed using compile->stub_entry_point();
1099   if (code_buffer() == NULL) {
1100     Matcher::soft_match_failure();
1101   } else {
1102     if (PrintAssembly && (WizardMode || Verbose))
1103       tty->print_cr("### Stub::%s", stub_name);
1104 
1105     if (!failing()) {
1106       assert(_fixed_slots == 0, "no fixed slots used for runtime stubs");
1107 
1108       // Make the NMethod
1109       // For now we mark the frame as never safe for profile stackwalking
1110       RuntimeStub *rs = RuntimeStub::new_runtime_stub(stub_name,
1111                                                       code_buffer(),
1112                                                       CodeOffsets::frame_never_safe,
1113                                                       // _code_offsets.value(CodeOffsets::Frame_Complete),
1114                                                       frame_size_in_words(),
1115                                                       _oop_map_set,
1116                                                       save_arg_registers);
1117       assert(rs != NULL && rs->is_runtime_stub(), "sanity check");
1118 
1119       _stub_entry_point = rs->entry_point();
1120     }
1121   }
1122 }
1123 
1124 //------------------------------Init-------------------------------------------
1125 // Prepare for a single compilation
1126 void Compile::Init(int aliaslevel) {
1127   _unique  = 0;
1128   _regalloc = NULL;
1129 
1130   _tf      = NULL;  // filled in later
1131   _top     = NULL;  // cached later
1132   _matcher = NULL;  // filled in later
1133   _cfg     = NULL;  // filled in later
1134 
1135   set_24_bit_selection_and_mode(Use24BitFP, false);
1136 
1137   _node_note_array = NULL;
1138   _default_node_notes = NULL;
1139   DEBUG_ONLY( _modified_nodes = NULL; ) // Used in Optimize()
1140 
1141   _immutable_memory = NULL; // filled in at first inquiry
1142 
1143   // Globally visible Nodes
1144   // First set TOP to NULL to give safe behavior during creation of RootNode
1145   set_cached_top_node(NULL);
1146   set_root(new RootNode());
1147   // Now that you have a Root to point to, create the real TOP
1148   set_cached_top_node( new ConNode(Type::TOP) );
1149   set_recent_alloc(NULL, NULL);
1150 
1151   // Create Debug Information Recorder to record scopes, oopmaps, etc.
1152   env()->set_oop_recorder(new OopRecorder(env()->arena()));
1153   env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
1154   env()->set_dependencies(new Dependencies(env()));
1155 
1156   _fixed_slots = 0;
1157   set_has_split_ifs(false);
1158   set_has_loops(has_method() && method()->has_loops()); // first approximation
1159   set_has_stringbuilder(false);
1160   set_has_boxed_value(false);
1161   _trap_can_recompile = false;  // no traps emitted yet
1162   _major_progress = true; // start out assuming good things will happen
1163   set_has_unsafe_access(false);
1164   set_max_vector_size(0);
1165   set_clear_upper_avx(false);  //false as default for clear upper bits of ymm registers
1166   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
1167   set_decompile_count(0);
1168 
1169   set_do_freq_based_layout(_directive->BlockLayoutByFrequencyOption);
1170   _loop_opts_cnt = LoopOptsCount;
1171   _has_flattened_accesses = false;
1172   _flattened_accesses_share_alias = true;
1173 
1174   set_do_inlining(Inline);
1175   set_max_inline_size(MaxInlineSize);
1176   set_freq_inline_size(FreqInlineSize);
1177   set_do_scheduling(OptoScheduling);
1178   set_do_count_invocations(false);
1179   set_do_method_data_update(false);
1180 
1181   set_do_vector_loop(false);
1182 
1183   if (AllowVectorizeOnDemand) {
1184     if (has_method() && (_directive->VectorizeOption || _directive->VectorizeDebugOption)) {
1185       set_do_vector_loop(true);
1186       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());})
1187     } else if (has_method() && method()->name() != 0 &&
1188                method()->intrinsic_id() == vmIntrinsics::_forEachRemaining) {
1189       set_do_vector_loop(true);
1190     }
1191   }
1192   set_use_cmove(UseCMoveUnconditionally /* || do_vector_loop()*/); //TODO: consider do_vector_loop() mandate use_cmove unconditionally
1193   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());})
1194 
1195   set_age_code(has_method() && method()->profile_aging());
1196   set_rtm_state(NoRTM); // No RTM lock eliding by default
1197   _max_node_limit = _directive->MaxNodeLimitOption;
1198 
1199 #if INCLUDE_RTM_OPT
1200   if (UseRTMLocking && has_method() && (method()->method_data_or_null() != NULL)) {
1201     int rtm_state = method()->method_data()->rtm_state();
1202     if (method_has_option("NoRTMLockEliding") || ((rtm_state & NoRTM) != 0)) {
1203       // Don't generate RTM lock eliding code.
1204       set_rtm_state(NoRTM);
1205     } else if (method_has_option("UseRTMLockEliding") || ((rtm_state & UseRTM) != 0) || !UseRTMDeopt) {
1206       // Generate RTM lock eliding code without abort ratio calculation code.
1207       set_rtm_state(UseRTM);
1208     } else if (UseRTMDeopt) {
1209       // Generate RTM lock eliding code and include abort ratio calculation
1210       // code if UseRTMDeopt is on.
1211       set_rtm_state(ProfileRTM);
1212     }
1213   }
1214 #endif
1215   if (VM_Version::supports_fast_class_init_checks() && has_method() && !is_osr_compilation() && method()->needs_clinit_barrier()) {
1216     set_clinit_barrier_on_entry(true);
1217   }
1218   if (debug_info()->recording_non_safepoints()) {
1219     set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
1220                         (comp_arena(), 8, 0, NULL));
1221     set_default_node_notes(Node_Notes::make(this));
1222   }
1223 
1224   // // -- Initialize types before each compile --
1225   // // Update cached type information
1226   // if( _method && _method->constants() )
1227   //   Type::update_loaded_types(_method, _method->constants());
1228 
1229   // Init alias_type map.
1230   if (!_do_escape_analysis && aliaslevel == 3)
1231     aliaslevel = 2;  // No unique types without escape analysis
1232   _AliasLevel = aliaslevel;
1233   const int grow_ats = 16;
1234   _max_alias_types = grow_ats;
1235   _alias_types   = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
1236   AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType,  grow_ats);
1237   Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
1238   {
1239     for (int i = 0; i < grow_ats; i++)  _alias_types[i] = &ats[i];
1240   }
1241   // Initialize the first few types.
1242   _alias_types[AliasIdxTop]->Init(AliasIdxTop, NULL);
1243   _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
1244   _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
1245   _num_alias_types = AliasIdxRaw+1;
1246   // Zero out the alias type cache.
1247   Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
1248   // A NULL adr_type hits in the cache right away.  Preload the right answer.
1249   probe_alias_cache(NULL)->_index = AliasIdxTop;
1250 
1251   _intrinsics = NULL;
1252   _macro_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1253   _predicate_opaqs = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1254   _expensive_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1255   _range_check_casts = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1256   _opaque4_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1257   _value_type_nodes = new (comp_arena()) Unique_Node_List(comp_arena());
1258   register_library_intrinsics();
1259 }
1260 
1261 //---------------------------init_start----------------------------------------
1262 // Install the StartNode on this compile object.
1263 void Compile::init_start(StartNode* s) {
1264   if (failing())
1265     return; // already failing
1266   assert(s == start(), "");
1267 }
1268 
1269 /**
1270  * Return the 'StartNode'. We must not have a pending failure, since the ideal graph
1271  * can be in an inconsistent state, i.e., we can get segmentation faults when traversing
1272  * the ideal graph.
1273  */
1274 StartNode* Compile::start() const {
1275   assert (!failing(), "Must not have pending failure. Reason is: %s", failure_reason());
1276   for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
1277     Node* start = root()->fast_out(i);
1278     if (start->is_Start()) {
1279       return start->as_Start();
1280     }
1281   }
1282   fatal("Did not find Start node!");
1283   return NULL;
1284 }
1285 
1286 //-------------------------------immutable_memory-------------------------------------
1287 // Access immutable memory
1288 Node* Compile::immutable_memory() {
1289   if (_immutable_memory != NULL) {
1290     return _immutable_memory;
1291   }
1292   StartNode* s = start();
1293   for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
1294     Node *p = s->fast_out(i);
1295     if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
1296       _immutable_memory = p;
1297       return _immutable_memory;
1298     }
1299   }
1300   ShouldNotReachHere();
1301   return NULL;
1302 }
1303 
1304 //----------------------set_cached_top_node------------------------------------
1305 // Install the cached top node, and make sure Node::is_top works correctly.
1306 void Compile::set_cached_top_node(Node* tn) {
1307   if (tn != NULL)  verify_top(tn);
1308   Node* old_top = _top;
1309   _top = tn;
1310   // Calling Node::setup_is_top allows the nodes the chance to adjust
1311   // their _out arrays.
1312   if (_top != NULL)     _top->setup_is_top();
1313   if (old_top != NULL)  old_top->setup_is_top();
1314   assert(_top == NULL || top()->is_top(), "");
1315 }
1316 
1317 #ifdef ASSERT
1318 uint Compile::count_live_nodes_by_graph_walk() {
1319   Unique_Node_List useful(comp_arena());
1320   // Get useful node list by walking the graph.
1321   identify_useful_nodes(useful);
1322   return useful.size();
1323 }
1324 
1325 void Compile::print_missing_nodes() {
1326 
1327   // Return if CompileLog is NULL and PrintIdealNodeCount is false.
1328   if ((_log == NULL) && (! PrintIdealNodeCount)) {
1329     return;
1330   }
1331 
1332   // This is an expensive function. It is executed only when the user
1333   // specifies VerifyIdealNodeCount option or otherwise knows the
1334   // additional work that needs to be done to identify reachable nodes
1335   // by walking the flow graph and find the missing ones using
1336   // _dead_node_list.
1337 
1338   Unique_Node_List useful(comp_arena());
1339   // Get useful node list by walking the graph.
1340   identify_useful_nodes(useful);
1341 
1342   uint l_nodes = C->live_nodes();
1343   uint l_nodes_by_walk = useful.size();
1344 
1345   if (l_nodes != l_nodes_by_walk) {
1346     if (_log != NULL) {
1347       _log->begin_head("mismatched_nodes count='%d'", abs((int) (l_nodes - l_nodes_by_walk)));
1348       _log->stamp();
1349       _log->end_head();
1350     }
1351     VectorSet& useful_member_set = useful.member_set();
1352     int last_idx = l_nodes_by_walk;
1353     for (int i = 0; i < last_idx; i++) {
1354       if (useful_member_set.test(i)) {
1355         if (_dead_node_list.test(i)) {
1356           if (_log != NULL) {
1357             _log->elem("mismatched_node_info node_idx='%d' type='both live and dead'", i);
1358           }
1359           if (PrintIdealNodeCount) {
1360             // Print the log message to tty
1361               tty->print_cr("mismatched_node idx='%d' both live and dead'", i);
1362               useful.at(i)->dump();
1363           }
1364         }
1365       }
1366       else if (! _dead_node_list.test(i)) {
1367         if (_log != NULL) {
1368           _log->elem("mismatched_node_info node_idx='%d' type='neither live nor dead'", i);
1369         }
1370         if (PrintIdealNodeCount) {
1371           // Print the log message to tty
1372           tty->print_cr("mismatched_node idx='%d' type='neither live nor dead'", i);
1373         }
1374       }
1375     }
1376     if (_log != NULL) {
1377       _log->tail("mismatched_nodes");
1378     }
1379   }
1380 }
1381 void Compile::record_modified_node(Node* n) {
1382   if (_modified_nodes != NULL && !_inlining_incrementally &&
1383       n->outcnt() != 0 && !n->is_Con()) {
1384     _modified_nodes->push(n);
1385   }
1386 }
1387 
1388 void Compile::remove_modified_node(Node* n) {
1389   if (_modified_nodes != NULL) {
1390     _modified_nodes->remove(n);
1391   }
1392 }
1393 #endif
1394 
1395 #ifndef PRODUCT
1396 void Compile::verify_top(Node* tn) const {
1397   if (tn != NULL) {
1398     assert(tn->is_Con(), "top node must be a constant");
1399     assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
1400     assert(tn->in(0) != NULL, "must have live top node");
1401   }
1402 }
1403 #endif
1404 
1405 
1406 ///-------------------Managing Per-Node Debug & Profile Info-------------------
1407 
1408 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
1409   guarantee(arr != NULL, "");
1410   int num_blocks = arr->length();
1411   if (grow_by < num_blocks)  grow_by = num_blocks;
1412   int num_notes = grow_by * _node_notes_block_size;
1413   Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
1414   Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
1415   while (num_notes > 0) {
1416     arr->append(notes);
1417     notes     += _node_notes_block_size;
1418     num_notes -= _node_notes_block_size;
1419   }
1420   assert(num_notes == 0, "exact multiple, please");
1421 }
1422 
1423 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
1424   if (source == NULL || dest == NULL)  return false;
1425 
1426   if (dest->is_Con())
1427     return false;               // Do not push debug info onto constants.
1428 
1429 #ifdef ASSERT
1430   // Leave a bread crumb trail pointing to the original node:
1431   if (dest != NULL && dest != source && dest->debug_orig() == NULL) {
1432     dest->set_debug_orig(source);
1433   }
1434 #endif
1435 
1436   if (node_note_array() == NULL)
1437     return false;               // Not collecting any notes now.
1438 
1439   // This is a copy onto a pre-existing node, which may already have notes.
1440   // If both nodes have notes, do not overwrite any pre-existing notes.
1441   Node_Notes* source_notes = node_notes_at(source->_idx);
1442   if (source_notes == NULL || source_notes->is_clear())  return false;
1443   Node_Notes* dest_notes   = node_notes_at(dest->_idx);
1444   if (dest_notes == NULL || dest_notes->is_clear()) {
1445     return set_node_notes_at(dest->_idx, source_notes);
1446   }
1447 
1448   Node_Notes merged_notes = (*source_notes);
1449   // The order of operations here ensures that dest notes will win...
1450   merged_notes.update_from(dest_notes);
1451   return set_node_notes_at(dest->_idx, &merged_notes);
1452 }
1453 
1454 
1455 //--------------------------allow_range_check_smearing-------------------------
1456 // Gating condition for coalescing similar range checks.
1457 // Sometimes we try 'speculatively' replacing a series of a range checks by a
1458 // single covering check that is at least as strong as any of them.
1459 // If the optimization succeeds, the simplified (strengthened) range check
1460 // will always succeed.  If it fails, we will deopt, and then give up
1461 // on the optimization.
1462 bool Compile::allow_range_check_smearing() const {
1463   // If this method has already thrown a range-check,
1464   // assume it was because we already tried range smearing
1465   // and it failed.
1466   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
1467   return !already_trapped;
1468 }
1469 
1470 
1471 //------------------------------flatten_alias_type-----------------------------
1472 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
1473   int offset = tj->offset();
1474   TypePtr::PTR ptr = tj->ptr();
1475 
1476   // Known instance (scalarizable allocation) alias only with itself.
1477   bool is_known_inst = tj->isa_oopptr() != NULL &&
1478                        tj->is_oopptr()->is_known_instance();
1479 
1480   // Process weird unsafe references.
1481   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
1482     bool default_value_load = EnableValhalla && tj->is_instptr()->klass() == ciEnv::current()->Class_klass();
1483     assert(InlineUnsafeOps || default_value_load, "indeterminate pointers come only from unsafe ops");
1484     assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
1485     tj = TypeOopPtr::BOTTOM;
1486     ptr = tj->ptr();
1487     offset = tj->offset();
1488   }
1489 
1490   // Array pointers need some flattening
1491   const TypeAryPtr *ta = tj->isa_aryptr();
1492   if (ta && ta->is_stable()) {
1493     // Erase stability property for alias analysis.
1494     tj = ta = ta->cast_to_stable(false);
1495   }
1496   if (ta && ta->is_not_flat()) {
1497     // Erase not flat property for alias analysis.
1498     tj = ta = ta->cast_to_not_flat(false);
1499   }
1500   if (ta && ta->is_not_null_free()) {
1501     // Erase not null free property for alias analysis.
1502     tj = ta = ta->cast_to_not_null_free(false);
1503   }
1504 
1505   if( ta && is_known_inst ) {
1506     if ( offset != Type::OffsetBot &&
1507          offset > arrayOopDesc::length_offset_in_bytes() ) {
1508       offset = Type::OffsetBot; // Flatten constant access into array body only
1509       tj = ta = TypeAryPtr::make(ptr, ta->ary(), ta->klass(), true, Type::Offset(offset), ta->field_offset(), ta->instance_id());
1510     }
1511   } else if( ta && _AliasLevel >= 2 ) {
1512     // For arrays indexed by constant indices, we flatten the alias
1513     // space to include all of the array body.  Only the header, klass
1514     // and array length can be accessed un-aliased.
1515     // For flattened value type array, each field has its own slice so
1516     // we must include the field offset.
1517     if( offset != Type::OffsetBot ) {
1518       if( ta->const_oop() ) { // MethodData* or Method*
1519         offset = Type::OffsetBot;   // Flatten constant access into array body
1520         tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),ta->ary(),ta->klass(),false,Type::Offset(offset), ta->field_offset());
1521       } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
1522         // range is OK as-is.
1523         tj = ta = TypeAryPtr::RANGE;
1524       } else if( offset == oopDesc::klass_offset_in_bytes() ) {
1525         tj = TypeInstPtr::KLASS; // all klass loads look alike
1526         ta = TypeAryPtr::RANGE; // generic ignored junk
1527         ptr = TypePtr::BotPTR;
1528       } else if( offset == oopDesc::mark_offset_in_bytes() ) {
1529         tj = TypeInstPtr::MARK;
1530         ta = TypeAryPtr::RANGE; // generic ignored junk
1531         ptr = TypePtr::BotPTR;
1532       } else if (BarrierSet::barrier_set()->barrier_set_c2()->flatten_gc_alias_type(tj)) {
1533         ta = tj->isa_aryptr();
1534       } else {                  // Random constant offset into array body
1535         offset = Type::OffsetBot;   // Flatten constant access into array body
1536         tj = ta = TypeAryPtr::make(ptr,ta->ary(),ta->klass(),false,Type::Offset(offset), ta->field_offset());
1537       }
1538     }
1539     // Arrays of fixed size alias with arrays of unknown size.
1540     if (ta->size() != TypeInt::POS) {
1541       const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
1542       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,ta->klass(),false,Type::Offset(offset), ta->field_offset());
1543     }
1544     // Arrays of known objects become arrays of unknown objects.
1545     if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
1546       const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
1547       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,Type::Offset(offset), ta->field_offset());
1548     }
1549     if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
1550       const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
1551       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,Type::Offset(offset), ta->field_offset());
1552     }
1553     // Initially all flattened array accesses share a single slice
1554     if (ta->elem()->isa_valuetype() && ta->elem() != TypeValueType::BOTTOM && _flattened_accesses_share_alias) {
1555       const TypeAry *tary = TypeAry::make(TypeValueType::BOTTOM, ta->size());
1556       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,Type::Offset(offset), Type::Offset(Type::OffsetBot));
1557     }
1558     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
1559     // cannot be distinguished by bytecode alone.
1560     if (ta->elem() == TypeInt::BOOL) {
1561       const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
1562       ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
1563       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,Type::Offset(offset), ta->field_offset());
1564     }
1565     // During the 2nd round of IterGVN, NotNull castings are removed.
1566     // Make sure the Bottom and NotNull variants alias the same.
1567     // Also, make sure exact and non-exact variants alias the same.
1568     if (ptr == TypePtr::NotNull || ta->klass_is_exact() || ta->speculative() != NULL) {
1569       tj = ta = TypeAryPtr::make(TypePtr::BotPTR,ta->ary(),ta->klass(),false,Type::Offset(offset), ta->field_offset());
1570     }
1571   }
1572 
1573   // Oop pointers need some flattening
1574   const TypeInstPtr *to = tj->isa_instptr();
1575   if( to && _AliasLevel >= 2 && to != TypeOopPtr::BOTTOM ) {
1576     ciInstanceKlass *k = to->klass()->as_instance_klass();
1577     if( ptr == TypePtr::Constant ) {
1578       if (to->klass() != ciEnv::current()->Class_klass() ||
1579           offset < k->size_helper() * wordSize) {
1580         // No constant oop pointers (such as Strings); they alias with
1581         // unknown strings.
1582         assert(!is_known_inst, "not scalarizable allocation");
1583         tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,Type::Offset(offset));
1584       }
1585     } else if( is_known_inst ) {
1586       tj = to; // Keep NotNull and klass_is_exact for instance type
1587     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
1588       // During the 2nd round of IterGVN, NotNull castings are removed.
1589       // Make sure the Bottom and NotNull variants alias the same.
1590       // Also, make sure exact and non-exact variants alias the same.
1591       tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,Type::Offset(offset));
1592     }
1593     if (to->speculative() != NULL) {
1594       tj = to = TypeInstPtr::make(to->ptr(),to->klass(),to->klass_is_exact(),to->const_oop(),Type::Offset(to->offset()), to->instance_id());
1595     }
1596     // Canonicalize the holder of this field
1597     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
1598       // First handle header references such as a LoadKlassNode, even if the
1599       // object's klass is unloaded at compile time (4965979).
1600       if (!is_known_inst) { // Do it only for non-instance types
1601         tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, NULL, Type::Offset(offset));
1602       }
1603     } else if (BarrierSet::barrier_set()->barrier_set_c2()->flatten_gc_alias_type(tj)) {
1604       to = tj->is_instptr();
1605     } else if (offset < 0 || offset >= k->size_helper() * wordSize) {
1606       // Static fields are in the space above the normal instance
1607       // fields in the java.lang.Class instance.
1608       if (to->klass() != ciEnv::current()->Class_klass()) {
1609         to = NULL;
1610         tj = TypeOopPtr::BOTTOM;
1611         offset = tj->offset();
1612       }
1613     } else {
1614       ciInstanceKlass *canonical_holder = k->get_canonical_holder(offset);
1615       if (!k->equals(canonical_holder) || tj->offset() != offset) {
1616         if( is_known_inst ) {
1617           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, true, NULL, Type::Offset(offset), to->instance_id());
1618         } else {
1619           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, false, NULL, Type::Offset(offset));
1620         }
1621       }
1622     }
1623   }
1624 
1625   // Klass pointers to object array klasses need some flattening
1626   const TypeKlassPtr *tk = tj->isa_klassptr();
1627   if( tk ) {
1628     // If we are referencing a field within a Klass, we need
1629     // to assume the worst case of an Object.  Both exact and
1630     // inexact types must flatten to the same alias class so
1631     // use NotNull as the PTR.
1632     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
1633 
1634       tj = tk = TypeKlassPtr::make(TypePtr::NotNull,
1635                                    TypeKlassPtr::OBJECT->klass(),
1636                                    Type::Offset(offset));
1637     }
1638 
1639     ciKlass* klass = tk->klass();
1640     if (klass != NULL && klass->is_obj_array_klass()) {
1641       ciKlass* k = TypeAryPtr::OOPS->klass();
1642       if( !k || !k->is_loaded() )                  // Only fails for some -Xcomp runs
1643         k = TypeInstPtr::BOTTOM->klass();
1644       tj = tk = TypeKlassPtr::make(TypePtr::NotNull, k, Type::Offset(offset));
1645     }
1646 
1647     // Check for precise loads from the primary supertype array and force them
1648     // to the supertype cache alias index.  Check for generic array loads from
1649     // the primary supertype array and also force them to the supertype cache
1650     // alias index.  Since the same load can reach both, we need to merge
1651     // these 2 disparate memories into the same alias class.  Since the
1652     // primary supertype array is read-only, there's no chance of confusion
1653     // where we bypass an array load and an array store.
1654     int primary_supers_offset = in_bytes(Klass::primary_supers_offset());
1655     if (offset == Type::OffsetBot ||
1656         (offset >= primary_supers_offset &&
1657          offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
1658         offset == (int)in_bytes(Klass::secondary_super_cache_offset())) {
1659       offset = in_bytes(Klass::secondary_super_cache_offset());
1660       tj = tk = TypeKlassPtr::make(TypePtr::NotNull, tk->klass(), Type::Offset(offset));
1661     }
1662   }
1663 
1664   // Flatten all Raw pointers together.
1665   if (tj->base() == Type::RawPtr)
1666     tj = TypeRawPtr::BOTTOM;
1667 
1668   if (tj->base() == Type::AnyPtr)
1669     tj = TypePtr::BOTTOM;      // An error, which the caller must check for.
1670 
1671   // Flatten all to bottom for now
1672   switch( _AliasLevel ) {
1673   case 0:
1674     tj = TypePtr::BOTTOM;
1675     break;
1676   case 1:                       // Flatten to: oop, static, field or array
1677     switch (tj->base()) {
1678     //case Type::AryPtr: tj = TypeAryPtr::RANGE;    break;
1679     case Type::RawPtr:   tj = TypeRawPtr::BOTTOM;   break;
1680     case Type::AryPtr:   // do not distinguish arrays at all
1681     case Type::InstPtr:  tj = TypeInstPtr::BOTTOM;  break;
1682     case Type::KlassPtr: tj = TypeKlassPtr::OBJECT; break;
1683     case Type::AnyPtr:   tj = TypePtr::BOTTOM;      break;  // caller checks it
1684     default: ShouldNotReachHere();
1685     }
1686     break;
1687   case 2:                       // No collapsing at level 2; keep all splits
1688   case 3:                       // No collapsing at level 3; keep all splits
1689     break;
1690   default:
1691     Unimplemented();
1692   }
1693 
1694   offset = tj->offset();
1695   assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
1696 
1697   assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
1698           (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
1699           (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
1700           (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
1701           (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1702           (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1703           (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1704           (BarrierSet::barrier_set()->barrier_set_c2()->verify_gc_alias_type(tj, offset)),
1705           "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
1706   assert( tj->ptr() != TypePtr::TopPTR &&
1707           tj->ptr() != TypePtr::AnyNull &&
1708           tj->ptr() != TypePtr::Null, "No imprecise addresses" );
1709 //    assert( tj->ptr() != TypePtr::Constant ||
1710 //            tj->base() == Type::RawPtr ||
1711 //            tj->base() == Type::KlassPtr, "No constant oop addresses" );
1712 
1713   return tj;
1714 }
1715 
1716 void Compile::AliasType::Init(int i, const TypePtr* at) {
1717   _index = i;
1718   _adr_type = at;
1719   _field = NULL;
1720   _element = NULL;
1721   _is_rewritable = true; // default
1722   const TypeOopPtr *atoop = (at != NULL) ? at->isa_oopptr() : NULL;
1723   if (atoop != NULL && atoop->is_known_instance()) {
1724     const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
1725     _general_index = Compile::current()->get_alias_index(gt);
1726   } else {
1727     _general_index = 0;
1728   }
1729 }
1730 
1731 BasicType Compile::AliasType::basic_type() const {
1732   if (element() != NULL) {
1733     const Type* element = adr_type()->is_aryptr()->elem();
1734     return element->isa_narrowoop() ? T_OBJECT : element->array_element_basic_type();
1735   } if (field() != NULL) {
1736     return field()->layout_type();
1737   } else {
1738     return T_ILLEGAL; // unknown
1739   }
1740 }
1741 
1742 //---------------------------------print_on------------------------------------
1743 #ifndef PRODUCT
1744 void Compile::AliasType::print_on(outputStream* st) {
1745   if (index() < 10)
1746         st->print("@ <%d> ", index());
1747   else  st->print("@ <%d>",  index());
1748   st->print(is_rewritable() ? "   " : " RO");
1749   int offset = adr_type()->offset();
1750   if (offset == Type::OffsetBot)
1751         st->print(" +any");
1752   else  st->print(" +%-3d", offset);
1753   st->print(" in ");
1754   adr_type()->dump_on(st);
1755   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
1756   if (field() != NULL && tjp) {
1757     if (tjp->klass()  != field()->holder() ||
1758         tjp->offset() != field()->offset_in_bytes()) {
1759       st->print(" != ");
1760       field()->print();
1761       st->print(" ***");
1762     }
1763   }
1764 }
1765 
1766 void print_alias_types() {
1767   Compile* C = Compile::current();
1768   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
1769   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
1770     C->alias_type(idx)->print_on(tty);
1771     tty->cr();
1772   }
1773 }
1774 #endif
1775 
1776 
1777 //----------------------------probe_alias_cache--------------------------------
1778 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
1779   intptr_t key = (intptr_t) adr_type;
1780   key ^= key >> logAliasCacheSize;
1781   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
1782 }
1783 
1784 
1785 //-----------------------------grow_alias_types--------------------------------
1786 void Compile::grow_alias_types() {
1787   const int old_ats  = _max_alias_types; // how many before?
1788   const int new_ats  = old_ats;          // how many more?
1789   const int grow_ats = old_ats+new_ats;  // how many now?
1790   _max_alias_types = grow_ats;
1791   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
1792   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
1793   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
1794   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
1795 }
1796 
1797 
1798 //--------------------------------find_alias_type------------------------------
1799 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field, bool uncached) {
1800   if (_AliasLevel == 0)
1801     return alias_type(AliasIdxBot);
1802 
1803   AliasCacheEntry* ace = NULL;
1804   if (!uncached) {
1805     ace = probe_alias_cache(adr_type);
1806     if (ace->_adr_type == adr_type) {
1807       return alias_type(ace->_index);
1808     }
1809   }
1810 
1811   // Handle special cases.
1812   if (adr_type == NULL)             return alias_type(AliasIdxTop);
1813   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
1814 
1815   // Do it the slow way.
1816   const TypePtr* flat = flatten_alias_type(adr_type);
1817 
1818 #ifdef ASSERT
1819   {
1820     ResourceMark rm;
1821     assert(flat == flatten_alias_type(flat), "not idempotent: adr_type = %s; flat = %s => %s",
1822            Type::str(adr_type), Type::str(flat), Type::str(flatten_alias_type(flat)));
1823     assert(flat != TypePtr::BOTTOM, "cannot alias-analyze an untyped ptr: adr_type = %s",
1824            Type::str(adr_type));
1825     if (flat->isa_oopptr() && !flat->isa_klassptr()) {
1826       const TypeOopPtr* foop = flat->is_oopptr();
1827       // Scalarizable allocations have exact klass always.
1828       bool exact = !foop->klass_is_exact() || foop->is_known_instance();
1829       const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
1830       assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type: foop = %s; xoop = %s",
1831              Type::str(foop), Type::str(xoop));
1832     }
1833   }
1834 #endif
1835 
1836   int idx = AliasIdxTop;
1837   for (int i = 0; i < num_alias_types(); i++) {
1838     if (alias_type(i)->adr_type() == flat) {
1839       idx = i;
1840       break;
1841     }
1842   }
1843 
1844   if (idx == AliasIdxTop) {
1845     if (no_create)  return NULL;
1846     // Grow the array if necessary.
1847     if (_num_alias_types == _max_alias_types)  grow_alias_types();
1848     // Add a new alias type.
1849     idx = _num_alias_types++;
1850     _alias_types[idx]->Init(idx, flat);
1851     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
1852     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
1853     if (flat->isa_instptr()) {
1854       if (flat->offset() == java_lang_Class::klass_offset_in_bytes()
1855           && flat->is_instptr()->klass() == env()->Class_klass())
1856         alias_type(idx)->set_rewritable(false);
1857     }
1858     ciField* field = NULL;
1859     if (flat->isa_aryptr()) {
1860 #ifdef ASSERT
1861       const int header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1862       // (T_BYTE has the weakest alignment and size restrictions...)
1863       assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
1864 #endif
1865       const Type* elemtype = flat->is_aryptr()->elem();
1866       if (flat->offset() == TypePtr::OffsetBot) {
1867         alias_type(idx)->set_element(elemtype);
1868       }
1869       int field_offset = flat->is_aryptr()->field_offset().get();
1870       if (elemtype->isa_valuetype() &&
1871           elemtype->value_klass() != NULL &&
1872           field_offset != Type::OffsetBot) {
1873         ciValueKlass* vk = elemtype->value_klass();
1874         field_offset += vk->first_field_offset();
1875         field = vk->get_field_by_offset(field_offset, false);
1876       }
1877     }
1878     if (flat->isa_klassptr()) {
1879       if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
1880         alias_type(idx)->set_rewritable(false);
1881       if (flat->offset() == in_bytes(Klass::modifier_flags_offset()))
1882         alias_type(idx)->set_rewritable(false);
1883       if (flat->offset() == in_bytes(Klass::access_flags_offset()))
1884         alias_type(idx)->set_rewritable(false);
1885       if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
1886         alias_type(idx)->set_rewritable(false);
1887       if (flat->offset() == in_bytes(Klass::layout_helper_offset()))
1888         alias_type(idx)->set_rewritable(false);
1889     }
1890     // %%% (We would like to finalize JavaThread::threadObj_offset(),
1891     // but the base pointer type is not distinctive enough to identify
1892     // references into JavaThread.)
1893 
1894     // Check for final fields.
1895     const TypeInstPtr* tinst = flat->isa_instptr();
1896     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
1897       if (tinst->const_oop() != NULL &&
1898           tinst->klass() == ciEnv::current()->Class_klass() &&
1899           tinst->offset() >= (tinst->klass()->as_instance_klass()->size_helper() * wordSize)) {
1900         // static field
1901         ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
1902         field = k->get_field_by_offset(tinst->offset(), true);
1903       } else if (tinst->klass()->is_valuetype()) {
1904         // Value type field
1905         ciValueKlass* vk = tinst->value_klass();
1906         field = vk->get_field_by_offset(tinst->offset(), false);
1907       } else {
1908         ciInstanceKlass* k = tinst->klass()->as_instance_klass();
1909         field = k->get_field_by_offset(tinst->offset(), false);
1910       }
1911     }
1912     assert(field == NULL ||
1913            original_field == NULL ||
1914            (field->holder() == original_field->holder() &&
1915             field->offset() == original_field->offset() &&
1916             field->is_static() == original_field->is_static()), "wrong field?");
1917     // Set field() and is_rewritable() attributes.
1918     if (field != NULL)  alias_type(idx)->set_field(field);
1919   }
1920 
1921   // Fill the cache for next time.
1922   if (!uncached) {
1923     ace->_adr_type = adr_type;
1924     ace->_index    = idx;
1925     assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
1926 
1927     // Might as well try to fill the cache for the flattened version, too.
1928     AliasCacheEntry* face = probe_alias_cache(flat);
1929     if (face->_adr_type == NULL) {
1930       face->_adr_type = flat;
1931       face->_index    = idx;
1932       assert(alias_type(flat) == alias_type(idx), "flat type must work too");
1933     }
1934   }
1935 
1936   return alias_type(idx);
1937 }
1938 
1939 
1940 Compile::AliasType* Compile::alias_type(ciField* field) {
1941   const TypeOopPtr* t;
1942   if (field->is_static())
1943     t = TypeInstPtr::make(field->holder()->java_mirror());
1944   else
1945     t = TypeOopPtr::make_from_klass_raw(field->holder());
1946   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);









1947   assert((field->is_final() || field->is_stable()) == !atp->is_rewritable(), "must get the rewritable bits correct");
1948   return atp;
1949 }
1950 
1951 
1952 //------------------------------have_alias_type--------------------------------
1953 bool Compile::have_alias_type(const TypePtr* adr_type) {
1954   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1955   if (ace->_adr_type == adr_type) {
1956     return true;
1957   }
1958 
1959   // Handle special cases.
1960   if (adr_type == NULL)             return true;
1961   if (adr_type == TypePtr::BOTTOM)  return true;
1962 
1963   return find_alias_type(adr_type, true, NULL) != NULL;
1964 }
1965 
1966 //-----------------------------must_alias--------------------------------------
1967 // True if all values of the given address type are in the given alias category.
1968 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
1969   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1970   if (adr_type == NULL)                 return true;  // NULL serves as TypePtr::TOP
1971   if (alias_idx == AliasIdxTop)         return false; // the empty category
1972   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
1973 
1974   // the only remaining possible overlap is identity
1975   int adr_idx = get_alias_index(adr_type);
1976   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1977   assert(adr_idx == alias_idx ||
1978          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
1979           && adr_type                       != TypeOopPtr::BOTTOM),
1980          "should not be testing for overlap with an unsafe pointer");
1981   return adr_idx == alias_idx;
1982 }
1983 
1984 //------------------------------can_alias--------------------------------------
1985 // True if any values of the given address type are in the given alias category.
1986 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
1987   if (alias_idx == AliasIdxTop)         return false; // the empty category
1988   if (adr_type == NULL)                 return false; // NULL serves as TypePtr::TOP
1989   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1990   if (adr_type->base() == Type::AnyPtr) return true;  // TypePtr::BOTTOM or its twins
1991 
1992   // the only remaining possible overlap is identity
1993   int adr_idx = get_alias_index(adr_type);
1994   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1995   return adr_idx == alias_idx;
1996 }
1997 
1998 
1999 
2000 //---------------------------pop_warm_call-------------------------------------
2001 WarmCallInfo* Compile::pop_warm_call() {
2002   WarmCallInfo* wci = _warm_calls;
2003   if (wci != NULL)  _warm_calls = wci->remove_from(wci);
2004   return wci;
2005 }
2006 
2007 //----------------------------Inline_Warm--------------------------------------
2008 int Compile::Inline_Warm() {
2009   // If there is room, try to inline some more warm call sites.
2010   // %%% Do a graph index compaction pass when we think we're out of space?
2011   if (!InlineWarmCalls)  return 0;
2012 
2013   int calls_made_hot = 0;
2014   int room_to_grow   = NodeCountInliningCutoff - unique();
2015   int amount_to_grow = MIN2(room_to_grow, (int)NodeCountInliningStep);
2016   int amount_grown   = 0;
2017   WarmCallInfo* call;
2018   while (amount_to_grow > 0 && (call = pop_warm_call()) != NULL) {
2019     int est_size = (int)call->size();
2020     if (est_size > (room_to_grow - amount_grown)) {
2021       // This one won't fit anyway.  Get rid of it.
2022       call->make_cold();
2023       continue;
2024     }
2025     call->make_hot();
2026     calls_made_hot++;
2027     amount_grown   += est_size;
2028     amount_to_grow -= est_size;
2029   }
2030 
2031   if (calls_made_hot > 0)  set_major_progress();
2032   return calls_made_hot;
2033 }
2034 
2035 
2036 //----------------------------Finish_Warm--------------------------------------
2037 void Compile::Finish_Warm() {
2038   if (!InlineWarmCalls)  return;
2039   if (failing())  return;
2040   if (warm_calls() == NULL)  return;
2041 
2042   // Clean up loose ends, if we are out of space for inlining.
2043   WarmCallInfo* call;
2044   while ((call = pop_warm_call()) != NULL) {
2045     call->make_cold();
2046   }
2047 }
2048 
2049 //---------------------cleanup_loop_predicates-----------------------
2050 // Remove the opaque nodes that protect the predicates so that all unused
2051 // checks and uncommon_traps will be eliminated from the ideal graph
2052 void Compile::cleanup_loop_predicates(PhaseIterGVN &igvn) {
2053   if (predicate_count()==0) return;
2054   for (int i = predicate_count(); i > 0; i--) {
2055     Node * n = predicate_opaque1_node(i-1);
2056     assert(n->Opcode() == Op_Opaque1, "must be");
2057     igvn.replace_node(n, n->in(1));
2058   }
2059   assert(predicate_count()==0, "should be clean!");
2060 }
2061 
2062 void Compile::add_range_check_cast(Node* n) {
2063   assert(n->isa_CastII()->has_range_check(), "CastII should have range check dependency");
2064   assert(!_range_check_casts->contains(n), "duplicate entry in range check casts");
2065   _range_check_casts->append(n);
2066 }
2067 
2068 // Remove all range check dependent CastIINodes.
2069 void Compile::remove_range_check_casts(PhaseIterGVN &igvn) {
2070   for (int i = range_check_cast_count(); i > 0; i--) {
2071     Node* cast = range_check_cast_node(i-1);
2072     assert(cast->isa_CastII()->has_range_check(), "CastII should have range check dependency");
2073     igvn.replace_node(cast, cast->in(1));
2074   }
2075   assert(range_check_cast_count() == 0, "should be empty");
2076 }
2077 
2078 void Compile::add_opaque4_node(Node* n) {
2079   assert(n->Opcode() == Op_Opaque4, "Opaque4 only");
2080   assert(!_opaque4_nodes->contains(n), "duplicate entry in Opaque4 list");
2081   _opaque4_nodes->append(n);
2082 }
2083 
2084 // Remove all Opaque4 nodes.
2085 void Compile::remove_opaque4_nodes(PhaseIterGVN &igvn) {
2086   for (int i = opaque4_count(); i > 0; i--) {
2087     Node* opaq = opaque4_node(i-1);
2088     assert(opaq->Opcode() == Op_Opaque4, "Opaque4 only");
2089     igvn.replace_node(opaq, opaq->in(2));
2090   }
2091   assert(opaque4_count() == 0, "should be empty");
2092 }
2093 
2094 void Compile::add_value_type(Node* n) {
2095   assert(n->is_ValueTypeBase(), "unexpected node");
2096   if (_value_type_nodes != NULL) {
2097     _value_type_nodes->push(n);
2098   }
2099 }
2100 
2101 void Compile::remove_value_type(Node* n) {
2102   assert(n->is_ValueTypeBase(), "unexpected node");
2103   if (_value_type_nodes != NULL) {
2104     _value_type_nodes->remove(n);
2105   }
2106 }
2107 
2108 // Does the return value keep otherwise useless value type allocations
2109 // alive?
2110 static bool return_val_keeps_allocations_alive(Node* ret_val) {
2111   ResourceMark rm;
2112   Unique_Node_List wq;
2113   wq.push(ret_val);
2114   bool some_allocations = false;
2115   for (uint i = 0; i < wq.size(); i++) {
2116     Node* n = wq.at(i);
2117     assert(!n->is_ValueTypeBase(), "chain of value type nodes");
2118     if (n->outcnt() > 1) {
2119       // Some other use for the allocation
2120       return false;
2121     } else if (n->is_Phi()) {
2122       for (uint j = 1; j < n->req(); j++) {
2123         wq.push(n->in(j));
2124       }
2125     } else if (n->is_CheckCastPP() &&
2126                n->in(1)->is_Proj() &&
2127                n->in(1)->in(0)->is_Allocate()) {
2128       some_allocations = true;
2129     }
2130   }
2131   return some_allocations;
2132 }
2133 
2134 void Compile::process_value_types(PhaseIterGVN &igvn) {
2135   // Make value types scalar in safepoints
2136   while (_value_type_nodes->size() != 0) {
2137     ValueTypeBaseNode* vt = _value_type_nodes->pop()->as_ValueTypeBase();
2138     vt->make_scalar_in_safepoints(&igvn);
2139     if (vt->is_ValueTypePtr()) {
2140       igvn.replace_node(vt, vt->get_oop());
2141     } else if (vt->outcnt() == 0) {
2142       igvn.remove_dead_node(vt);
2143     }
2144   }
2145   _value_type_nodes = NULL;
2146   if (tf()->returns_value_type_as_fields()) {
2147     Node* ret = NULL;
2148     for (uint i = 1; i < root()->req(); i++){
2149       Node* in = root()->in(i);
2150       if (in->Opcode() == Op_Return) {
2151         assert(ret == NULL, "only one return");
2152         ret = in;
2153       }
2154     }
2155     if (ret != NULL) {
2156       Node* ret_val = ret->in(TypeFunc::Parms);
2157       if (igvn.type(ret_val)->isa_oopptr() &&
2158           return_val_keeps_allocations_alive(ret_val)) {
2159         igvn.replace_input_of(ret, TypeFunc::Parms, ValueTypeNode::tagged_klass(igvn.type(ret_val)->value_klass(), igvn));
2160         assert(ret_val->outcnt() == 0, "should be dead now");
2161         igvn.remove_dead_node(ret_val);
2162       }
2163     }
2164   }
2165   igvn.optimize();
2166 }
2167 
2168 void Compile::adjust_flattened_array_access_aliases(PhaseIterGVN& igvn) {
2169   if (!_has_flattened_accesses) {
2170     return;
2171   }
2172   // Initially, all flattened array accesses share the same slice to
2173   // keep dependencies with Object[] array accesses (that could be
2174   // to a flattened array) correct. We're done with parsing so we
2175   // now know all flattened array accesses in this compile
2176   // unit. Let's move flattened array accesses to their own slice,
2177   // one per element field. This should help memory access
2178   // optimizations.
2179   ResourceMark rm;
2180   Unique_Node_List wq;
2181   wq.push(root());
2182 
2183   Node_List mergememnodes;
2184   Node_List memnodes;
2185 
2186   // Alias index currently shared by all flattened memory accesses
2187   int index = get_alias_index(TypeAryPtr::VALUES);
2188 
2189   // Find MergeMem nodes and flattened array accesses
2190   for (uint i = 0; i < wq.size(); i++) {
2191     Node* n = wq.at(i);
2192     if (n->is_Mem()) {
2193       const TypePtr* adr_type = NULL;
2194       if (n->Opcode() == Op_StoreCM) {
2195         adr_type = get_adr_type(get_alias_index(n->in(MemNode::OopStore)->adr_type()));
2196       } else {
2197         adr_type = get_adr_type(get_alias_index(n->adr_type()));
2198       }
2199       if (adr_type == TypeAryPtr::VALUES) {
2200         memnodes.push(n);
2201       }
2202     } else if (n->is_MergeMem()) {
2203       MergeMemNode* mm = n->as_MergeMem();
2204       if (mm->memory_at(index) != mm->base_memory()) {
2205         mergememnodes.push(n);
2206       }
2207     }
2208     for (uint j = 0; j < n->req(); j++) {
2209       Node* m = n->in(j);
2210       if (m != NULL) {
2211         wq.push(m);
2212       }
2213     }
2214   }
2215 
2216   if (memnodes.size() > 0) {
2217     _flattened_accesses_share_alias = false;
2218 
2219     // We are going to change the slice for the flattened array
2220     // accesses so we need to clear the cache entries that refer to
2221     // them.
2222     for (uint i = 0; i < AliasCacheSize; i++) {
2223       AliasCacheEntry* ace = &_alias_cache[i];
2224       if (ace->_adr_type != NULL &&
2225           ace->_adr_type->isa_aryptr() &&
2226           ace->_adr_type->is_aryptr()->elem()->isa_valuetype()) {
2227         ace->_adr_type = NULL;
2228         ace->_index = 0;
2229       }
2230     }
2231 
2232     // Find what aliases we are going to add
2233     int start_alias = num_alias_types()-1;
2234     int stop_alias = 0;
2235 
2236     for (uint i = 0; i < memnodes.size(); i++) {
2237       Node* m = memnodes.at(i);
2238       const TypePtr* adr_type = NULL;
2239       if (m->Opcode() == Op_StoreCM) {
2240         adr_type = m->in(MemNode::OopStore)->adr_type();
2241         Node* clone = new StoreCMNode(m->in(MemNode::Control), m->in(MemNode::Memory), m->in(MemNode::Address),
2242                                       m->adr_type(), m->in(MemNode::ValueIn), m->in(MemNode::OopStore),
2243                                       get_alias_index(adr_type));
2244         igvn.register_new_node_with_optimizer(clone);
2245         igvn.replace_node(m, clone);
2246       } else {
2247         adr_type = m->adr_type();
2248 #ifdef ASSERT
2249         m->as_Mem()->set_adr_type(adr_type);
2250 #endif
2251       }
2252       int idx = get_alias_index(adr_type);
2253       start_alias = MIN2(start_alias, idx);
2254       stop_alias = MAX2(stop_alias, idx);
2255     }
2256 
2257     assert(stop_alias >= start_alias, "should have expanded aliases");
2258 
2259     Node_Stack stack(0);
2260 #ifdef ASSERT
2261     VectorSet seen(Thread::current()->resource_area());
2262 #endif
2263     // Now let's fix the memory graph so each flattened array access
2264     // is moved to the right slice. Start from the MergeMem nodes.
2265     uint last = unique();
2266     for (uint i = 0; i < mergememnodes.size(); i++) {
2267       MergeMemNode* current = mergememnodes.at(i)->as_MergeMem();
2268       Node* n = current->memory_at(index);
2269       MergeMemNode* mm = NULL;
2270       do {
2271         // Follow memory edges through memory accesses, phis and
2272         // narrow membars and push nodes on the stack. Once we hit
2273         // bottom memory, we pop element off the stack one at a
2274         // time, in reverse order, and move them to the right slice
2275         // by changing their memory edges.
2276         if ((n->is_Phi() && n->adr_type() != TypePtr::BOTTOM) || n->is_Mem() || n->adr_type() == TypeAryPtr::VALUES) {
2277           assert(!seen.test_set(n->_idx), "");
2278           // Uses (a load for instance) will need to be moved to the
2279           // right slice as well and will get a new memory state
2280           // that we don't know yet. The use could also be the
2281           // backedge of a loop. We put a place holder node between
2282           // the memory node and its uses. We replace that place
2283           // holder with the correct memory state once we know it,
2284           // i.e. when nodes are popped off the stack. Using the
2285           // place holder make the logic work in the presence of
2286           // loops.
2287           if (n->outcnt() > 1) {
2288             Node* place_holder = NULL;
2289             assert(!n->has_out_with(Op_Node), "");
2290             for (DUIterator k = n->outs(); n->has_out(k); k++) {
2291               Node* u = n->out(k);
2292               if (u != current && u->_idx < last) {
2293                 bool success = false;
2294                 for (uint l = 0; l < u->req(); l++) {
2295                   if (!stack.is_empty() && u == stack.node() && l == stack.index()) {
2296                     continue;
2297                   }
2298                   Node* in = u->in(l);
2299                   if (in == n) {
2300                     if (place_holder == NULL) {
2301                       place_holder = new Node(1);
2302                       place_holder->init_req(0, n);
2303                     }
2304                     igvn.replace_input_of(u, l, place_holder);
2305                     success = true;
2306                   }
2307                 }
2308                 if (success) {
2309                   --k;
2310                 }
2311               }
2312             }
2313           }
2314           if (n->is_Phi()) {
2315             stack.push(n, 1);
2316             n = n->in(1);
2317           } else if (n->is_Mem()) {
2318             stack.push(n, n->req());
2319             n = n->in(MemNode::Memory);
2320           } else {
2321             assert(n->is_Proj() && n->in(0)->Opcode() == Op_MemBarCPUOrder, "");
2322             stack.push(n, n->req());
2323             n = n->in(0)->in(TypeFunc::Memory);
2324           }
2325         } else {
2326           assert(n->adr_type() == TypePtr::BOTTOM || (n->Opcode() == Op_Node && n->_idx >= last) || (n->is_Proj() && n->in(0)->is_Initialize()), "");
2327           // Build a new MergeMem node to carry the new memory state
2328           // as we build it. IGVN should fold extraneous MergeMem
2329           // nodes.
2330           mm = MergeMemNode::make(n);
2331           igvn.register_new_node_with_optimizer(mm);
2332           while (stack.size() > 0) {
2333             Node* m = stack.node();
2334             uint idx = stack.index();
2335             if (m->is_Mem()) {
2336               // Move memory node to its new slice
2337               const TypePtr* adr_type = m->adr_type();
2338               int alias = get_alias_index(adr_type);
2339               Node* prev = mm->memory_at(alias);
2340               igvn.replace_input_of(m, MemNode::Memory, prev);
2341               mm->set_memory_at(alias, m);
2342             } else if (m->is_Phi()) {
2343               // We need as many new phis as there are new aliases
2344               igvn.replace_input_of(m, idx, mm);
2345               if (idx == m->req()-1) {
2346                 Node* r = m->in(0);
2347                 for (uint j = (uint)start_alias; j <= (uint)stop_alias; j++) {
2348                   const Type* adr_type = get_adr_type(j);
2349                   if (!adr_type->isa_aryptr() || !adr_type->is_aryptr()->elem()->isa_valuetype()) {
2350                     continue;
2351                   }
2352                   Node* phi = new PhiNode(r, Type::MEMORY, get_adr_type(j));
2353                   igvn.register_new_node_with_optimizer(phi);
2354                   for (uint k = 1; k < m->req(); k++) {
2355                     phi->init_req(k, m->in(k)->as_MergeMem()->memory_at(j));
2356                   }
2357                   mm->set_memory_at(j, phi);
2358                 }
2359                 Node* base_phi = new PhiNode(r, Type::MEMORY, TypePtr::BOTTOM);
2360                 igvn.register_new_node_with_optimizer(base_phi);
2361                 for (uint k = 1; k < m->req(); k++) {
2362                   base_phi->init_req(k, m->in(k)->as_MergeMem()->base_memory());
2363                 }
2364                 mm->set_base_memory(base_phi);
2365               }
2366             } else {
2367               // This is a MemBarCPUOrder node from
2368               // Parse::array_load()/Parse::array_store(), in the
2369               // branch that handles flattened arrays hidden under
2370               // an Object[] array. We also need one new membar per
2371               // new alias to keep the unknown access that the
2372               // membars protect properly ordered with accesses to
2373               // known flattened array.
2374               assert(m->is_Proj(), "projection expected");
2375               Node* ctrl = m->in(0)->in(TypeFunc::Control);
2376               igvn.replace_input_of(m->in(0), TypeFunc::Control, top());
2377               for (uint j = (uint)start_alias; j <= (uint)stop_alias; j++) {
2378                 const Type* adr_type = get_adr_type(j);
2379                 if (!adr_type->isa_aryptr() || !adr_type->is_aryptr()->elem()->isa_valuetype()) {
2380                   continue;
2381                 }
2382                 MemBarNode* mb = new MemBarCPUOrderNode(this, j, NULL);
2383                 igvn.register_new_node_with_optimizer(mb);
2384                 Node* mem = mm->memory_at(j);
2385                 mb->init_req(TypeFunc::Control, ctrl);
2386                 mb->init_req(TypeFunc::Memory, mem);
2387                 ctrl = new ProjNode(mb, TypeFunc::Control);
2388                 igvn.register_new_node_with_optimizer(ctrl);
2389                 mem = new ProjNode(mb, TypeFunc::Memory);
2390                 igvn.register_new_node_with_optimizer(mem);
2391                 mm->set_memory_at(j, mem);
2392               }
2393               igvn.replace_node(m->in(0)->as_Multi()->proj_out(TypeFunc::Control), ctrl);
2394             }
2395             if (idx < m->req()-1) {
2396               idx += 1;
2397               stack.set_index(idx);
2398               n = m->in(idx);
2399               break;
2400             }
2401             // Take care of place holder nodes
2402             if (m->has_out_with(Op_Node)) {
2403               Node* place_holder = m->find_out_with(Op_Node);
2404               if (place_holder != NULL) {
2405                 Node* mm_clone = mm->clone();
2406                 igvn.register_new_node_with_optimizer(mm_clone);
2407                 Node* hook = new Node(1);
2408                 hook->init_req(0, mm);
2409                 igvn.replace_node(place_holder, mm_clone);
2410                 hook->destruct();
2411               }
2412               assert(!m->has_out_with(Op_Node), "place holder should be gone now");
2413             }
2414             stack.pop();
2415           }
2416         }
2417       } while(stack.size() > 0);
2418       // Fix the memory state at the MergeMem we started from
2419       igvn.rehash_node_delayed(current);
2420       for (uint j = (uint)start_alias; j <= (uint)stop_alias; j++) {
2421         const Type* adr_type = get_adr_type(j);
2422         if (!adr_type->isa_aryptr() || !adr_type->is_aryptr()->elem()->isa_valuetype()) {
2423           continue;
2424         }
2425         current->set_memory_at(j, mm);
2426       }
2427       current->set_memory_at(index, current->base_memory());
2428     }
2429     igvn.optimize();
2430   }
2431   print_method(PHASE_SPLIT_VALUES_ARRAY, 2);
2432 }
2433 
2434 
2435 // StringOpts and late inlining of string methods
2436 void Compile::inline_string_calls(bool parse_time) {
2437   {
2438     // remove useless nodes to make the usage analysis simpler
2439     ResourceMark rm;
2440     PhaseRemoveUseless pru(initial_gvn(), for_igvn());
2441   }
2442 
2443   {
2444     ResourceMark rm;
2445     print_method(PHASE_BEFORE_STRINGOPTS, 3);
2446     PhaseStringOpts pso(initial_gvn(), for_igvn());
2447     print_method(PHASE_AFTER_STRINGOPTS, 3);
2448   }
2449 
2450   // now inline anything that we skipped the first time around
2451   if (!parse_time) {
2452     _late_inlines_pos = _late_inlines.length();
2453   }
2454 
2455   while (_string_late_inlines.length() > 0) {
2456     CallGenerator* cg = _string_late_inlines.pop();
2457     cg->do_late_inline();
2458     if (failing())  return;
2459   }
2460   _string_late_inlines.trunc_to(0);
2461 }
2462 
2463 // Late inlining of boxing methods
2464 void Compile::inline_boxing_calls(PhaseIterGVN& igvn) {
2465   if (_boxing_late_inlines.length() > 0) {
2466     assert(has_boxed_value(), "inconsistent");
2467 
2468     PhaseGVN* gvn = initial_gvn();
2469     set_inlining_incrementally(true);
2470 
2471     assert( igvn._worklist.size() == 0, "should be done with igvn" );
2472     for_igvn()->clear();
2473     gvn->replace_with(&igvn);
2474 
2475     _late_inlines_pos = _late_inlines.length();
2476 
2477     while (_boxing_late_inlines.length() > 0) {
2478       CallGenerator* cg = _boxing_late_inlines.pop();
2479       cg->do_late_inline();
2480       if (failing())  return;
2481     }
2482     _boxing_late_inlines.trunc_to(0);
2483 
2484     inline_incrementally_cleanup(igvn);
2485 
2486     set_inlining_incrementally(false);
2487   }
2488 }
2489 
2490 bool Compile::inline_incrementally_one() {
2491   assert(IncrementalInline, "incremental inlining should be on");
2492 
2493   TracePhase tp("incrementalInline_inline", &timers[_t_incrInline_inline]);
2494   set_inlining_progress(false);
2495   set_do_cleanup(false);
2496   int i = 0;
2497   for (; i <_late_inlines.length() && !inlining_progress(); i++) {
2498     CallGenerator* cg = _late_inlines.at(i);
2499     _late_inlines_pos = i+1;
2500     cg->do_late_inline();
2501     if (failing())  return false;
2502   }
2503   int j = 0;
2504   for (; i < _late_inlines.length(); i++, j++) {
2505     _late_inlines.at_put(j, _late_inlines.at(i));
2506   }
2507   _late_inlines.trunc_to(j);
2508   assert(inlining_progress() || _late_inlines.length() == 0, "");
2509 
2510   bool needs_cleanup = do_cleanup() || over_inlining_cutoff();
2511 
2512   set_inlining_progress(false);
2513   set_do_cleanup(false);
2514   return (_late_inlines.length() > 0) && !needs_cleanup;
2515 }
2516 
2517 void Compile::inline_incrementally_cleanup(PhaseIterGVN& igvn) {
2518   {
2519     TracePhase tp("incrementalInline_pru", &timers[_t_incrInline_pru]);
2520     ResourceMark rm;
2521     PhaseRemoveUseless pru(initial_gvn(), for_igvn());
2522   }
2523   {
2524     TracePhase tp("incrementalInline_igvn", &timers[_t_incrInline_igvn]);
2525     igvn = PhaseIterGVN(initial_gvn());
2526     igvn.optimize();
2527   }
2528 }
2529 
2530 // Perform incremental inlining until bound on number of live nodes is reached
2531 void Compile::inline_incrementally(PhaseIterGVN& igvn) {
2532   TracePhase tp("incrementalInline", &timers[_t_incrInline]);
2533 
2534   set_inlining_incrementally(true);
2535   uint low_live_nodes = 0;
2536 
2537   while (_late_inlines.length() > 0) {
2538     if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2539       if (low_live_nodes < (uint)LiveNodeCountInliningCutoff * 8 / 10) {
2540         TracePhase tp("incrementalInline_ideal", &timers[_t_incrInline_ideal]);
2541         // PhaseIdealLoop is expensive so we only try it once we are
2542         // out of live nodes and we only try it again if the previous
2543         // helped got the number of nodes down significantly
2544         PhaseIdealLoop::optimize(igvn, LoopOptsNone);
2545         if (failing())  return;
2546         low_live_nodes = live_nodes();
2547         _major_progress = true;
2548       }
2549 
2550       if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2551         break; // finish
2552       }
2553     }
2554 
2555     for_igvn()->clear();
2556     initial_gvn()->replace_with(&igvn);
2557 
2558     while (inline_incrementally_one()) {
2559       assert(!failing(), "inconsistent");
2560     }
2561 
2562     if (failing())  return;
2563 
2564     inline_incrementally_cleanup(igvn);
2565 
2566     if (failing())  return;
2567   }
2568   assert( igvn._worklist.size() == 0, "should be done with igvn" );
2569 
2570   if (_string_late_inlines.length() > 0) {
2571     assert(has_stringbuilder(), "inconsistent");
2572     for_igvn()->clear();
2573     initial_gvn()->replace_with(&igvn);
2574 
2575     inline_string_calls(false);
2576 
2577     if (failing())  return;
2578 
2579     inline_incrementally_cleanup(igvn);
2580   }
2581 
2582   set_inlining_incrementally(false);
2583 }
2584 
2585 
2586 bool Compile::optimize_loops(PhaseIterGVN& igvn, LoopOptsMode mode) {
2587   if(_loop_opts_cnt > 0) {
2588     debug_only( int cnt = 0; );
2589     while(major_progress() && (_loop_opts_cnt > 0)) {
2590       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2591       assert( cnt++ < 40, "infinite cycle in loop optimization" );
2592       PhaseIdealLoop::optimize(igvn, mode);
2593       _loop_opts_cnt--;
2594       if (failing())  return false;
2595       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
2596     }
2597   }
2598   return true;
2599 }
2600 
2601 // Remove edges from "root" to each SafePoint at a backward branch.
2602 // They were inserted during parsing (see add_safepoint()) to make
2603 // infinite loops without calls or exceptions visible to root, i.e.,
2604 // useful.
2605 void Compile::remove_root_to_sfpts_edges(PhaseIterGVN& igvn) {
2606   Node *r = root();
2607   if (r != NULL) {
2608     for (uint i = r->req(); i < r->len(); ++i) {
2609       Node *n = r->in(i);
2610       if (n != NULL && n->is_SafePoint()) {
2611         r->rm_prec(i);
2612         if (n->outcnt() == 0) {
2613           igvn.remove_dead_node(n);
2614         }
2615         --i;
2616       }
2617     }
2618   }
2619 }
2620 
2621 //------------------------------Optimize---------------------------------------
2622 // Given a graph, optimize it.
2623 void Compile::Optimize() {
2624   TracePhase tp("optimizer", &timers[_t_optimizer]);
2625 
2626 #ifndef PRODUCT
2627   if (_directive->BreakAtCompileOption) {
2628     BREAKPOINT;
2629   }
2630 
2631 #endif
2632 
2633   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
2634 #ifdef ASSERT
2635   bs->verify_gc_barriers(this, BarrierSetC2::BeforeOptimize);
2636 #endif
2637 
2638   ResourceMark rm;
2639 
2640   print_inlining_reinit();
2641 
2642   NOT_PRODUCT( verify_graph_edges(); )
2643 
2644   print_method(PHASE_AFTER_PARSING);
2645 
2646  {
2647   // Iterative Global Value Numbering, including ideal transforms
2648   // Initialize IterGVN with types and values from parse-time GVN
2649   PhaseIterGVN igvn(initial_gvn());
2650 #ifdef ASSERT
2651   _modified_nodes = new (comp_arena()) Unique_Node_List(comp_arena());
2652 #endif
2653   {
2654     TracePhase tp("iterGVN", &timers[_t_iterGVN]);
2655     igvn.optimize();
2656   }
2657 
2658   if (failing())  return;
2659 
2660   print_method(PHASE_ITER_GVN1, 2);
2661 
2662   inline_incrementally(igvn);
2663 
2664   print_method(PHASE_INCREMENTAL_INLINE, 2);
2665 
2666   if (failing())  return;
2667 
2668   if (eliminate_boxing()) {
2669     // Inline valueOf() methods now.
2670     inline_boxing_calls(igvn);
2671 
2672     if (AlwaysIncrementalInline) {
2673       inline_incrementally(igvn);
2674     }
2675 
2676     print_method(PHASE_INCREMENTAL_BOXING_INLINE, 2);
2677 
2678     if (failing())  return;
2679   }
2680 
2681   // Now that all inlining is over, cut edge from root to loop
2682   // safepoints
2683   remove_root_to_sfpts_edges(igvn);
2684 
2685   // Remove the speculative part of types and clean up the graph from
2686   // the extra CastPP nodes whose only purpose is to carry them. Do
2687   // that early so that optimizations are not disrupted by the extra
2688   // CastPP nodes.
2689   remove_speculative_types(igvn);
2690 
2691   // No more new expensive nodes will be added to the list from here
2692   // so keep only the actual candidates for optimizations.
2693   cleanup_expensive_nodes(igvn);
2694 
2695   if (!failing() && RenumberLiveNodes && live_nodes() + NodeLimitFudgeFactor < unique()) {
2696     Compile::TracePhase tp("", &timers[_t_renumberLive]);
2697     initial_gvn()->replace_with(&igvn);
2698     for_igvn()->clear();
2699     Unique_Node_List new_worklist(C->comp_arena());
2700     {
2701       ResourceMark rm;
2702       PhaseRenumberLive prl = PhaseRenumberLive(initial_gvn(), for_igvn(), &new_worklist);
2703     }
2704     set_for_igvn(&new_worklist);
2705     igvn = PhaseIterGVN(initial_gvn());
2706     igvn.optimize();
2707   }
2708 
2709   if (_value_type_nodes->size() > 0) {
2710     // Do this once all inlining is over to avoid getting inconsistent debug info
2711     process_value_types(igvn);
2712   }
2713 
2714   adjust_flattened_array_access_aliases(igvn);
2715 
2716   // Perform escape analysis
2717   if (_do_escape_analysis && ConnectionGraph::has_candidates(this)) {
2718     if (has_loops()) {
2719       // Cleanup graph (remove dead nodes).
2720       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2721       PhaseIdealLoop::optimize(igvn, LoopOptsNone);
2722       if (major_progress()) print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
2723       if (failing())  return;
2724     }
2725     ConnectionGraph::do_analysis(this, &igvn);
2726 
2727     if (failing())  return;
2728 
2729     // Optimize out fields loads from scalar replaceable allocations.
2730     igvn.optimize();
2731     print_method(PHASE_ITER_GVN_AFTER_EA, 2);
2732 
2733     if (failing())  return;
2734 
2735     if (congraph() != NULL && macro_count() > 0) {
2736       TracePhase tp("macroEliminate", &timers[_t_macroEliminate]);
2737       PhaseMacroExpand mexp(igvn);
2738       mexp.eliminate_macro_nodes();
2739       igvn.set_delay_transform(false);
2740 
2741       igvn.optimize();
2742       print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
2743 
2744       if (failing())  return;
2745     }
2746   }
2747 
2748   // Loop transforms on the ideal graph.  Range Check Elimination,
2749   // peeling, unrolling, etc.
2750 
2751   // Set loop opts counter
2752   if((_loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
2753     {
2754       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2755       PhaseIdealLoop::optimize(igvn, LoopOptsDefault);
2756       _loop_opts_cnt--;
2757       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP1, 2);
2758       if (failing())  return;
2759     }
2760     // Loop opts pass if partial peeling occurred in previous pass
2761     if(PartialPeelLoop && major_progress() && (_loop_opts_cnt > 0)) {
2762       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2763       PhaseIdealLoop::optimize(igvn, LoopOptsSkipSplitIf);
2764       _loop_opts_cnt--;
2765       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP2, 2);
2766       if (failing())  return;
2767     }
2768     // Loop opts pass for loop-unrolling before CCP
2769     if(major_progress() && (_loop_opts_cnt > 0)) {
2770       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2771       PhaseIdealLoop::optimize(igvn, LoopOptsSkipSplitIf);
2772       _loop_opts_cnt--;
2773       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP3, 2);
2774     }
2775     if (!failing()) {
2776       // Verify that last round of loop opts produced a valid graph
2777       TracePhase tp("idealLoopVerify", &timers[_t_idealLoopVerify]);
2778       PhaseIdealLoop::verify(igvn);
2779     }
2780   }
2781   if (failing())  return;
2782 
2783   // Conditional Constant Propagation;
2784   PhaseCCP ccp( &igvn );
2785   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
2786   {
2787     TracePhase tp("ccp", &timers[_t_ccp]);
2788     ccp.do_transform();
2789   }
2790   print_method(PHASE_CPP1, 2);
2791 
2792   assert( true, "Break here to ccp.dump_old2new_map()");
2793 
2794   // Iterative Global Value Numbering, including ideal transforms
2795   {
2796     TracePhase tp("iterGVN2", &timers[_t_iterGVN2]);
2797     igvn = ccp;
2798     igvn.optimize();
2799   }
2800   print_method(PHASE_ITER_GVN2, 2);
2801 
2802   if (failing())  return;
2803 
2804   // Loop transforms on the ideal graph.  Range Check Elimination,
2805   // peeling, unrolling, etc.
2806   if (!optimize_loops(igvn, LoopOptsDefault)) {
2807     return;
2808   }
2809 
2810   if (failing())  return;
2811 
2812   // Ensure that major progress is now clear
2813   C->clear_major_progress();
2814 
2815   {
2816     // Verify that all previous optimizations produced a valid graph
2817     // at least to this point, even if no loop optimizations were done.
2818     TracePhase tp("idealLoopVerify", &timers[_t_idealLoopVerify]);
2819     PhaseIdealLoop::verify(igvn);
2820   }
2821 
2822   if (range_check_cast_count() > 0) {
2823     // No more loop optimizations. Remove all range check dependent CastIINodes.
2824     C->remove_range_check_casts(igvn);
2825     igvn.optimize();
2826   }
2827 
2828 #ifdef ASSERT
2829   bs->verify_gc_barriers(this, BarrierSetC2::BeforeLateInsertion);
2830 #endif
2831 
2832   bs->barrier_insertion_phase(C, igvn);
2833   if (failing())  return;
2834 
2835 #ifdef ASSERT
2836   bs->verify_gc_barriers(this, BarrierSetC2::BeforeMacroExpand);
2837 #endif
2838 
2839   {
2840     TracePhase tp("macroExpand", &timers[_t_macroExpand]);
2841     PhaseMacroExpand  mex(igvn);
2842     if (mex.expand_macro_nodes()) {
2843       assert(failing(), "must bail out w/ explicit message");
2844       return;
2845     }
2846     print_method(PHASE_MACRO_EXPANSION, 2);
2847   }
2848 
2849   {
2850     TracePhase tp("barrierExpand", &timers[_t_barrierExpand]);
2851     if (bs->expand_barriers(this, igvn)) {
2852       assert(failing(), "must bail out w/ explicit message");
2853       return;
2854     }
2855     print_method(PHASE_BARRIER_EXPANSION, 2);
2856   }
2857 
2858   if (opaque4_count() > 0) {
2859     C->remove_opaque4_nodes(igvn);
2860     igvn.optimize();
2861   }
2862 
2863   DEBUG_ONLY( _modified_nodes = NULL; )
2864  } // (End scope of igvn; run destructor if necessary for asserts.)
2865 
2866  process_print_inlining();
2867  // A method with only infinite loops has no edges entering loops from root
2868  {
2869    TracePhase tp("graphReshape", &timers[_t_graphReshaping]);
2870    if (final_graph_reshaping()) {
2871      assert(failing(), "must bail out w/ explicit message");
2872      return;
2873    }
2874  }
2875 
2876  print_method(PHASE_OPTIMIZE_FINISHED, 2);
2877 }
2878 
2879 //------------------------------Code_Gen---------------------------------------
2880 // Given a graph, generate code for it
2881 void Compile::Code_Gen() {
2882   if (failing()) {
2883     return;
2884   }
2885 
2886   // Perform instruction selection.  You might think we could reclaim Matcher
2887   // memory PDQ, but actually the Matcher is used in generating spill code.
2888   // Internals of the Matcher (including some VectorSets) must remain live
2889   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
2890   // set a bit in reclaimed memory.
2891 
2892   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2893   // nodes.  Mapping is only valid at the root of each matched subtree.
2894   NOT_PRODUCT( verify_graph_edges(); )
2895 
2896   Matcher matcher;
2897   _matcher = &matcher;
2898   {
2899     TracePhase tp("matcher", &timers[_t_matcher]);
2900     matcher.match();
2901   }
2902   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2903   // nodes.  Mapping is only valid at the root of each matched subtree.
2904   NOT_PRODUCT( verify_graph_edges(); )
2905 
2906   // If you have too many nodes, or if matching has failed, bail out
2907   check_node_count(0, "out of nodes matching instructions");
2908   if (failing()) {
2909     return;
2910   }
2911 
2912   print_method(PHASE_MATCHING, 2);
2913 
2914   // Build a proper-looking CFG
2915   PhaseCFG cfg(node_arena(), root(), matcher);
2916   _cfg = &cfg;
2917   {
2918     TracePhase tp("scheduler", &timers[_t_scheduler]);
2919     bool success = cfg.do_global_code_motion();
2920     if (!success) {
2921       return;
2922     }
2923 
2924     print_method(PHASE_GLOBAL_CODE_MOTION, 2);
2925     NOT_PRODUCT( verify_graph_edges(); )
2926     debug_only( cfg.verify(); )
2927   }
2928 
2929   PhaseChaitin regalloc(unique(), cfg, matcher, false);
2930   _regalloc = &regalloc;
2931   {
2932     TracePhase tp("regalloc", &timers[_t_registerAllocation]);
2933     // Perform register allocation.  After Chaitin, use-def chains are
2934     // no longer accurate (at spill code) and so must be ignored.
2935     // Node->LRG->reg mappings are still accurate.
2936     _regalloc->Register_Allocate();
2937 
2938     // Bail out if the allocator builds too many nodes
2939     if (failing()) {
2940       return;
2941     }
2942   }
2943 
2944   // Prior to register allocation we kept empty basic blocks in case the
2945   // the allocator needed a place to spill.  After register allocation we
2946   // are not adding any new instructions.  If any basic block is empty, we
2947   // can now safely remove it.
2948   {
2949     TracePhase tp("blockOrdering", &timers[_t_blockOrdering]);
2950     cfg.remove_empty_blocks();
2951     if (do_freq_based_layout()) {
2952       PhaseBlockLayout layout(cfg);
2953     } else {
2954       cfg.set_loop_alignment();
2955     }
2956     cfg.fixup_flow();
2957   }
2958 
2959   // Apply peephole optimizations
2960   if( OptoPeephole ) {
2961     TracePhase tp("peephole", &timers[_t_peephole]);
2962     PhasePeephole peep( _regalloc, cfg);
2963     peep.do_transform();
2964   }
2965 
2966   // Do late expand if CPU requires this.
2967   if (Matcher::require_postalloc_expand) {
2968     TracePhase tp("postalloc_expand", &timers[_t_postalloc_expand]);
2969     cfg.postalloc_expand(_regalloc);
2970   }
2971 
2972   // Convert Nodes to instruction bits in a buffer
2973   {
2974     TraceTime tp("output", &timers[_t_output], CITime);
2975     Output();
2976   }
2977 
2978   print_method(PHASE_FINAL_CODE);
2979 
2980   // He's dead, Jim.
2981   _cfg     = (PhaseCFG*)((intptr_t)0xdeadbeef);
2982   _regalloc = (PhaseChaitin*)((intptr_t)0xdeadbeef);
2983 }
2984 
2985 
2986 //------------------------------dump_asm---------------------------------------
2987 // Dump formatted assembly
2988 #if defined(SUPPORT_OPTO_ASSEMBLY)
2989 void Compile::dump_asm_on(outputStream* st, int* pcs, uint pc_limit) {
2990 
2991   int pc_digits = 3; // #chars required for pc
2992   int sb_chars  = 3; // #chars for "start bundle" indicator
2993   int tab_size  = 8;
2994   if (pcs != NULL) {
2995     int max_pc = 0;
2996     for (uint i = 0; i < pc_limit; i++) {
2997       max_pc = (max_pc < pcs[i]) ? pcs[i] : max_pc;
2998     }
2999     pc_digits  = ((max_pc < 4096) ? 3 : ((max_pc < 65536) ? 4 : ((max_pc < 65536*256) ? 6 : 8))); // #chars required for pc
3000   }
3001   int prefix_len = ((pc_digits + sb_chars + tab_size - 1)/tab_size)*tab_size;
3002 
3003   bool cut_short = false;
3004   st->print_cr("#");
3005   st->print("#  ");  _tf->dump_on(st);  st->cr();
3006   st->print_cr("#");
3007 
3008   // For all blocks
3009   int pc = 0x0;                 // Program counter
3010   char starts_bundle = ' ';
3011   _regalloc->dump_frame();
3012 
3013   Node *n = NULL;
3014   for (uint i = 0; i < _cfg->number_of_blocks(); i++) {
3015     if (VMThread::should_terminate()) {
3016       cut_short = true;
3017       break;
3018     }
3019     Block* block = _cfg->get_block(i);
3020     if (block->is_connector() && !Verbose) {
3021       continue;
3022     }
3023     n = block->head();
3024     if ((pcs != NULL) && (n->_idx < pc_limit)) {
3025       pc = pcs[n->_idx];
3026       st->print("%*.*x", pc_digits, pc_digits, pc);
3027     }
3028     st->fill_to(prefix_len);
3029     block->dump_head(_cfg, st);
3030     if (block->is_connector()) {
3031       st->fill_to(prefix_len);
3032       st->print_cr("# Empty connector block");
3033     } else if (block->num_preds() == 2 && block->pred(1)->is_CatchProj() && block->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
3034       st->fill_to(prefix_len);
3035       st->print_cr("# Block is sole successor of call");
3036     }
3037 
3038     // For all instructions
3039     Node *delay = NULL;
3040     for (uint j = 0; j < block->number_of_nodes(); j++) {
3041       if (VMThread::should_terminate()) {
3042         cut_short = true;
3043         break;
3044       }
3045       n = block->get_node(j);
3046       if (valid_bundle_info(n)) {
3047         Bundle* bundle = node_bundling(n);
3048         if (bundle->used_in_unconditional_delay()) {
3049           delay = n;
3050           continue;
3051         }
3052         if (bundle->starts_bundle()) {
3053           starts_bundle = '+';
3054         }
3055       }
3056 
3057       if (WizardMode) {
3058         n->dump();
3059       }
3060 
3061       if( !n->is_Region() &&    // Dont print in the Assembly
3062           !n->is_Phi() &&       // a few noisely useless nodes
3063           !n->is_Proj() &&
3064           !n->is_MachTemp() &&
3065           !n->is_SafePointScalarObject() &&
3066           !n->is_Catch() &&     // Would be nice to print exception table targets
3067           !n->is_MergeMem() &&  // Not very interesting
3068           !n->is_top() &&       // Debug info table constants
3069           !(n->is_Con() && !n->is_Mach())// Debug info table constants
3070           ) {
3071         if ((pcs != NULL) && (n->_idx < pc_limit)) {
3072           pc = pcs[n->_idx];
3073           st->print("%*.*x", pc_digits, pc_digits, pc);
3074         } else {
3075           st->fill_to(pc_digits);
3076         }
3077         st->print(" %c ", starts_bundle);
3078         starts_bundle = ' ';
3079         st->fill_to(prefix_len);
3080         n->format(_regalloc, st);
3081         st->cr();
3082       }
3083 
3084       // If we have an instruction with a delay slot, and have seen a delay,
3085       // then back up and print it
3086       if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
3087         // Coverity finding - Explicit null dereferenced.
3088         guarantee(delay != NULL, "no unconditional delay instruction");
3089         if (WizardMode) delay->dump();
3090 
3091         if (node_bundling(delay)->starts_bundle())
3092           starts_bundle = '+';
3093         if ((pcs != NULL) && (n->_idx < pc_limit)) {
3094           pc = pcs[n->_idx];
3095           st->print("%*.*x", pc_digits, pc_digits, pc);
3096         } else {
3097           st->fill_to(pc_digits);
3098         }
3099         st->print(" %c ", starts_bundle);
3100         starts_bundle = ' ';
3101         st->fill_to(prefix_len);
3102         delay->format(_regalloc, st);
3103         st->cr();
3104         delay = NULL;
3105       }
3106 
3107       // Dump the exception table as well
3108       if( n->is_Catch() && (Verbose || WizardMode) ) {
3109         // Print the exception table for this offset
3110         _handler_table.print_subtable_for(pc);
3111       }
3112       st->bol(); // Make sure we start on a new line
3113     }
3114     st->cr(); // one empty line between blocks
3115     assert(cut_short || delay == NULL, "no unconditional delay branch");
3116   } // End of per-block dump
3117 
3118   if (cut_short)  st->print_cr("*** disassembly is cut short ***");
3119 }
3120 #endif
3121 
3122 //------------------------------Final_Reshape_Counts---------------------------
3123 // This class defines counters to help identify when a method
3124 // may/must be executed using hardware with only 24-bit precision.
3125 struct Final_Reshape_Counts : public StackObj {
3126   int  _call_count;             // count non-inlined 'common' calls
3127   int  _float_count;            // count float ops requiring 24-bit precision
3128   int  _double_count;           // count double ops requiring more precision
3129   int  _java_call_count;        // count non-inlined 'java' calls
3130   int  _inner_loop_count;       // count loops which need alignment
3131   VectorSet _visited;           // Visitation flags
3132   Node_List _tests;             // Set of IfNodes & PCTableNodes
3133 
3134   Final_Reshape_Counts() :
3135     _call_count(0), _float_count(0), _double_count(0),
3136     _java_call_count(0), _inner_loop_count(0),
3137     _visited( Thread::current()->resource_area() ) { }
3138 
3139   void inc_call_count  () { _call_count  ++; }
3140   void inc_float_count () { _float_count ++; }
3141   void inc_double_count() { _double_count++; }
3142   void inc_java_call_count() { _java_call_count++; }
3143   void inc_inner_loop_count() { _inner_loop_count++; }
3144 
3145   int  get_call_count  () const { return _call_count  ; }
3146   int  get_float_count () const { return _float_count ; }
3147   int  get_double_count() const { return _double_count; }
3148   int  get_java_call_count() const { return _java_call_count; }
3149   int  get_inner_loop_count() const { return _inner_loop_count; }
3150 };
3151 
3152 #ifdef ASSERT
3153 static bool oop_offset_is_sane(const TypeInstPtr* tp) {
3154   ciInstanceKlass *k = tp->klass()->as_instance_klass();
3155   // Make sure the offset goes inside the instance layout.
3156   return k->contains_field_offset(tp->offset());
3157   // Note that OffsetBot and OffsetTop are very negative.
3158 }
3159 #endif
3160 
3161 // Eliminate trivially redundant StoreCMs and accumulate their
3162 // precedence edges.
3163 void Compile::eliminate_redundant_card_marks(Node* n) {
3164   assert(n->Opcode() == Op_StoreCM, "expected StoreCM");
3165   if (n->in(MemNode::Address)->outcnt() > 1) {
3166     // There are multiple users of the same address so it might be
3167     // possible to eliminate some of the StoreCMs
3168     Node* mem = n->in(MemNode::Memory);
3169     Node* adr = n->in(MemNode::Address);
3170     Node* val = n->in(MemNode::ValueIn);
3171     Node* prev = n;
3172     bool done = false;
3173     // Walk the chain of StoreCMs eliminating ones that match.  As
3174     // long as it's a chain of single users then the optimization is
3175     // safe.  Eliminating partially redundant StoreCMs would require
3176     // cloning copies down the other paths.
3177     while (mem->Opcode() == Op_StoreCM && mem->outcnt() == 1 && !done) {
3178       if (adr == mem->in(MemNode::Address) &&
3179           val == mem->in(MemNode::ValueIn)) {
3180         // redundant StoreCM
3181         if (mem->req() > MemNode::OopStore) {
3182           // Hasn't been processed by this code yet.
3183           n->add_prec(mem->in(MemNode::OopStore));
3184         } else {
3185           // Already converted to precedence edge
3186           for (uint i = mem->req(); i < mem->len(); i++) {
3187             // Accumulate any precedence edges
3188             if (mem->in(i) != NULL) {
3189               n->add_prec(mem->in(i));
3190             }
3191           }
3192           // Everything above this point has been processed.
3193           done = true;
3194         }
3195         // Eliminate the previous StoreCM
3196         prev->set_req(MemNode::Memory, mem->in(MemNode::Memory));
3197         assert(mem->outcnt() == 0, "should be dead");
3198         mem->disconnect_inputs(NULL, this);
3199       } else {
3200         prev = mem;
3201       }
3202       mem = prev->in(MemNode::Memory);
3203     }
3204   }
3205 }
3206 
3207 
3208 //------------------------------final_graph_reshaping_impl----------------------
3209 // Implement items 1-5 from final_graph_reshaping below.
3210 void Compile::final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &frc) {
3211 
3212   if ( n->outcnt() == 0 ) return; // dead node
3213   uint nop = n->Opcode();
3214 
3215   // Check for 2-input instruction with "last use" on right input.
3216   // Swap to left input.  Implements item (2).
3217   if( n->req() == 3 &&          // two-input instruction
3218       n->in(1)->outcnt() > 1 && // left use is NOT a last use
3219       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
3220       n->in(2)->outcnt() == 1 &&// right use IS a last use
3221       !n->in(2)->is_Con() ) {   // right use is not a constant
3222     // Check for commutative opcode
3223     switch( nop ) {
3224     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddL:
3225     case Op_MaxI:  case Op_MinI:
3226     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulL:
3227     case Op_AndL:  case Op_XorL:  case Op_OrL:
3228     case Op_AndI:  case Op_XorI:  case Op_OrI: {
3229       // Move "last use" input to left by swapping inputs
3230       n->swap_edges(1, 2);
3231       break;
3232     }
3233     default:
3234       break;
3235     }
3236   }
3237 
3238 #ifdef ASSERT
3239   if( n->is_Mem() ) {
3240     int alias_idx = get_alias_index(n->as_Mem()->adr_type());
3241     assert( n->in(0) != NULL || alias_idx != Compile::AliasIdxRaw ||
3242             // oop will be recorded in oop map if load crosses safepoint
3243             n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
3244                              LoadNode::is_immutable_value(n->in(MemNode::Address))),
3245             "raw memory operations should have control edge");
3246   }
3247   if (n->is_MemBar()) {
3248     MemBarNode* mb = n->as_MemBar();
3249     if (mb->trailing_store() || mb->trailing_load_store()) {
3250       assert(mb->leading_membar()->trailing_membar() == mb, "bad membar pair");
3251       Node* mem = BarrierSet::barrier_set()->barrier_set_c2()->step_over_gc_barrier(mb->in(MemBarNode::Precedent));
3252       assert((mb->trailing_store() && mem->is_Store() && mem->as_Store()->is_release()) ||
3253              (mb->trailing_load_store() && mem->is_LoadStore()), "missing mem op");
3254     } else if (mb->leading()) {
3255       assert(mb->trailing_membar()->leading_membar() == mb, "bad membar pair");
3256     }
3257   }
3258 #endif
3259   // Count FPU ops and common calls, implements item (3)
3260   bool gc_handled = BarrierSet::barrier_set()->barrier_set_c2()->final_graph_reshaping(this, n, nop);
3261   if (!gc_handled) {
3262     final_graph_reshaping_main_switch(n, frc, nop);
3263   }
3264 
3265   // Collect CFG split points
3266   if (n->is_MultiBranch() && !n->is_RangeCheck()) {
3267     frc._tests.push(n);
3268   }
3269 }
3270 
3271 void Compile::final_graph_reshaping_main_switch(Node* n, Final_Reshape_Counts& frc, uint nop) {
3272   switch( nop ) {
3273   // Count all float operations that may use FPU
3274   case Op_AddF:
3275   case Op_SubF:
3276   case Op_MulF:
3277   case Op_DivF:
3278   case Op_NegF:
3279   case Op_ModF:
3280   case Op_ConvI2F:
3281   case Op_ConF:
3282   case Op_CmpF:
3283   case Op_CmpF3:
3284   // case Op_ConvL2F: // longs are split into 32-bit halves
3285     frc.inc_float_count();
3286     break;
3287 
3288   case Op_ConvF2D:
3289   case Op_ConvD2F:
3290     frc.inc_float_count();
3291     frc.inc_double_count();
3292     break;
3293 
3294   // Count all double operations that may use FPU
3295   case Op_AddD:
3296   case Op_SubD:
3297   case Op_MulD:
3298   case Op_DivD:
3299   case Op_NegD:
3300   case Op_ModD:
3301   case Op_ConvI2D:
3302   case Op_ConvD2I:
3303   // case Op_ConvL2D: // handled by leaf call
3304   // case Op_ConvD2L: // handled by leaf call
3305   case Op_ConD:
3306   case Op_CmpD:
3307   case Op_CmpD3:
3308     frc.inc_double_count();
3309     break;
3310   case Op_Opaque1:              // Remove Opaque Nodes before matching
3311   case Op_Opaque2:              // Remove Opaque Nodes before matching
3312   case Op_Opaque3:
3313     n->subsume_by(n->in(1), this);
3314     break;
3315   case Op_CallStaticJava:
3316   case Op_CallJava:
3317   case Op_CallDynamicJava:
3318     frc.inc_java_call_count(); // Count java call site;
3319   case Op_CallRuntime:
3320   case Op_CallLeaf:
3321   case Op_CallLeafNoFP: {
3322     assert (n->is_Call(), "");
3323     CallNode *call = n->as_Call();
3324     // Count call sites where the FP mode bit would have to be flipped.
3325     // Do not count uncommon runtime calls:
3326     // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
3327     // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
3328     if (!call->is_CallStaticJava() || !call->as_CallStaticJava()->_name) {
3329       frc.inc_call_count();   // Count the call site
3330     } else {                  // See if uncommon argument is shared
3331       Node *n = call->in(TypeFunc::Parms);
3332       int nop = n->Opcode();
3333       // Clone shared simple arguments to uncommon calls, item (1).
3334       if (n->outcnt() > 1 &&
3335           !n->is_Proj() &&
3336           nop != Op_CreateEx &&
3337           nop != Op_CheckCastPP &&
3338           nop != Op_DecodeN &&
3339           nop != Op_DecodeNKlass &&
3340           !n->is_Mem() &&
3341           !n->is_Phi()) {
3342         Node *x = n->clone();
3343         call->set_req(TypeFunc::Parms, x);
3344       }
3345     }
3346     break;
3347   }
3348 
3349   case Op_StoreD:
3350   case Op_LoadD:
3351   case Op_LoadD_unaligned:
3352     frc.inc_double_count();
3353     goto handle_mem;
3354   case Op_StoreF:
3355   case Op_LoadF:
3356     frc.inc_float_count();
3357     goto handle_mem;
3358 
3359   case Op_StoreCM:
3360     {
3361       // Convert OopStore dependence into precedence edge
3362       Node* prec = n->in(MemNode::OopStore);
3363       n->del_req(MemNode::OopStore);
3364       n->add_prec(prec);
3365       eliminate_redundant_card_marks(n);
3366     }
3367 
3368     // fall through
3369 
3370   case Op_StoreB:
3371   case Op_StoreC:
3372   case Op_StorePConditional:
3373   case Op_StoreI:
3374   case Op_StoreL:
3375   case Op_StoreIConditional:
3376   case Op_StoreLConditional:
3377   case Op_CompareAndSwapB:
3378   case Op_CompareAndSwapS:
3379   case Op_CompareAndSwapI:
3380   case Op_CompareAndSwapL:
3381   case Op_CompareAndSwapP:
3382   case Op_CompareAndSwapN:
3383   case Op_WeakCompareAndSwapB:
3384   case Op_WeakCompareAndSwapS:
3385   case Op_WeakCompareAndSwapI:
3386   case Op_WeakCompareAndSwapL:
3387   case Op_WeakCompareAndSwapP:
3388   case Op_WeakCompareAndSwapN:
3389   case Op_CompareAndExchangeB:
3390   case Op_CompareAndExchangeS:
3391   case Op_CompareAndExchangeI:
3392   case Op_CompareAndExchangeL:
3393   case Op_CompareAndExchangeP:
3394   case Op_CompareAndExchangeN:
3395   case Op_GetAndAddS:
3396   case Op_GetAndAddB:
3397   case Op_GetAndAddI:
3398   case Op_GetAndAddL:
3399   case Op_GetAndSetS:
3400   case Op_GetAndSetB:
3401   case Op_GetAndSetI:
3402   case Op_GetAndSetL:
3403   case Op_GetAndSetP:
3404   case Op_GetAndSetN:
3405   case Op_StoreP:
3406   case Op_StoreN:
3407   case Op_StoreNKlass:
3408   case Op_LoadB:
3409   case Op_LoadUB:
3410   case Op_LoadUS:
3411   case Op_LoadI:
3412   case Op_LoadKlass:
3413   case Op_LoadNKlass:
3414   case Op_LoadL:
3415   case Op_LoadL_unaligned:
3416   case Op_LoadPLocked:
3417   case Op_LoadP:
3418   case Op_LoadN:
3419   case Op_LoadRange:
3420   case Op_LoadS: {
3421   handle_mem:
3422 #ifdef ASSERT
3423     if( VerifyOptoOopOffsets ) {
3424       MemNode* mem  = n->as_Mem();
3425       // Check to see if address types have grounded out somehow.
3426       const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
3427       assert( !tp || oop_offset_is_sane(tp), "" );
3428     }
3429 #endif
3430     if (EnableValhalla && (nop == Op_LoadKlass || nop == Op_LoadNKlass)) {
3431       const TypeKlassPtr* tk = n->bottom_type()->make_ptr()->is_klassptr();
3432       assert(!tk->klass_is_exact(), "should have been folded");
3433       ciKlass* klass = tk->klass();
3434       bool maybe_value_array = klass->is_java_lang_Object();
3435       if (!maybe_value_array && klass->is_obj_array_klass()) {
3436         klass = klass->as_array_klass()->element_klass();
3437         maybe_value_array = klass->is_java_lang_Object() || klass->is_interface() || klass->is_valuetype();
3438       }
3439       if (maybe_value_array) {
3440         // Array load klass needs to filter out property bits (but not
3441         // GetNullFreePropertyNode which needs to extract the null free bits)
3442         uint last = unique();
3443         Node* pointer = NULL;
3444         if (nop == Op_LoadKlass) {
3445           Node* cast = new CastP2XNode(NULL, n);
3446           Node* masked = new LShiftXNode(cast, new ConINode(TypeInt::make(oopDesc::storage_props_nof_bits)));
3447           masked = new RShiftXNode(masked, new ConINode(TypeInt::make(oopDesc::storage_props_nof_bits)));
3448           pointer = new CastX2PNode(masked);
3449           pointer = new CheckCastPPNode(NULL, pointer, n->bottom_type());
3450         } else {
3451           Node* cast = new CastN2INode(n);
3452           Node* masked = new AndINode(cast, new ConINode(TypeInt::make(oopDesc::compressed_klass_mask())));
3453           pointer = new CastI2NNode(masked, n->bottom_type());
3454         }
3455         for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3456           Node* u = n->fast_out(i);
3457           if (u->_idx < last && u->Opcode() != Op_GetNullFreeProperty) {
3458             int nb = u->replace_edge(n, pointer);
3459             --i, imax -= nb;
3460           }
3461         }
3462       }
3463     }
3464     break;
3465   }
3466 
3467   case Op_AddP: {               // Assert sane base pointers
3468     Node *addp = n->in(AddPNode::Address);
3469     assert( !addp->is_AddP() ||
3470             addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
3471             addp->in(AddPNode::Base) == n->in(AddPNode::Base),
3472             "Base pointers must match (addp %u)", addp->_idx );
3473 #ifdef _LP64
3474     if ((UseCompressedOops || UseCompressedClassPointers) &&
3475         addp->Opcode() == Op_ConP &&
3476         addp == n->in(AddPNode::Base) &&
3477         n->in(AddPNode::Offset)->is_Con()) {
3478       // If the transformation of ConP to ConN+DecodeN is beneficial depends
3479       // on the platform and on the compressed oops mode.
3480       // Use addressing with narrow klass to load with offset on x86.
3481       // Some platforms can use the constant pool to load ConP.
3482       // Do this transformation here since IGVN will convert ConN back to ConP.
3483       const Type* t = addp->bottom_type();
3484       bool is_oop   = t->isa_oopptr() != NULL;
3485       bool is_klass = t->isa_klassptr() != NULL;
3486 
3487       if ((is_oop   && Matcher::const_oop_prefer_decode()  ) ||
3488           (is_klass && Matcher::const_klass_prefer_decode())) {
3489         Node* nn = NULL;
3490 
3491         int op = is_oop ? Op_ConN : Op_ConNKlass;
3492 
3493         // Look for existing ConN node of the same exact type.
3494         Node* r  = root();
3495         uint cnt = r->outcnt();
3496         for (uint i = 0; i < cnt; i++) {
3497           Node* m = r->raw_out(i);
3498           if (m!= NULL && m->Opcode() == op &&
3499               m->bottom_type()->make_ptr() == t) {
3500             nn = m;
3501             break;
3502           }
3503         }
3504         if (nn != NULL) {
3505           // Decode a narrow oop to match address
3506           // [R12 + narrow_oop_reg<<3 + offset]
3507           if (is_oop) {
3508             nn = new DecodeNNode(nn, t);
3509           } else {
3510             nn = new DecodeNKlassNode(nn, t);
3511           }
3512           // Check for succeeding AddP which uses the same Base.
3513           // Otherwise we will run into the assertion above when visiting that guy.
3514           for (uint i = 0; i < n->outcnt(); ++i) {
3515             Node *out_i = n->raw_out(i);
3516             if (out_i && out_i->is_AddP() && out_i->in(AddPNode::Base) == addp) {
3517               out_i->set_req(AddPNode::Base, nn);
3518 #ifdef ASSERT
3519               for (uint j = 0; j < out_i->outcnt(); ++j) {
3520                 Node *out_j = out_i->raw_out(j);
3521                 assert(out_j == NULL || !out_j->is_AddP() || out_j->in(AddPNode::Base) != addp,
3522                        "more than 2 AddP nodes in a chain (out_j %u)", out_j->_idx);
3523               }
3524 #endif
3525             }
3526           }
3527           n->set_req(AddPNode::Base, nn);
3528           n->set_req(AddPNode::Address, nn);
3529           if (addp->outcnt() == 0) {
3530             addp->disconnect_inputs(NULL, this);
3531           }
3532         }
3533       }
3534     }
3535 #endif
3536     // platform dependent reshaping of the address expression
3537     reshape_address(n->as_AddP());
3538     break;
3539   }
3540 
3541   case Op_CastPP: {
3542     // Remove CastPP nodes to gain more freedom during scheduling but
3543     // keep the dependency they encode as control or precedence edges
3544     // (if control is set already) on memory operations. Some CastPP
3545     // nodes don't have a control (don't carry a dependency): skip
3546     // those.
3547     if (n->in(0) != NULL) {
3548       ResourceMark rm;
3549       Unique_Node_List wq;
3550       wq.push(n);
3551       for (uint next = 0; next < wq.size(); ++next) {
3552         Node *m = wq.at(next);
3553         for (DUIterator_Fast imax, i = m->fast_outs(imax); i < imax; i++) {
3554           Node* use = m->fast_out(i);
3555           if (use->is_Mem() || use->is_EncodeNarrowPtr()) {
3556             use->ensure_control_or_add_prec(n->in(0));
3557           } else {
3558             switch(use->Opcode()) {
3559             case Op_AddP:
3560             case Op_DecodeN:
3561             case Op_DecodeNKlass:
3562             case Op_CheckCastPP:
3563             case Op_CastPP:
3564               wq.push(use);
3565               break;
3566             }
3567           }
3568         }
3569       }
3570     }
3571     const bool is_LP64 = LP64_ONLY(true) NOT_LP64(false);
3572     if (is_LP64 && n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
3573       Node* in1 = n->in(1);
3574       const Type* t = n->bottom_type();
3575       Node* new_in1 = in1->clone();
3576       new_in1->as_DecodeN()->set_type(t);
3577 
3578       if (!Matcher::narrow_oop_use_complex_address()) {
3579         //
3580         // x86, ARM and friends can handle 2 adds in addressing mode
3581         // and Matcher can fold a DecodeN node into address by using
3582         // a narrow oop directly and do implicit NULL check in address:
3583         //
3584         // [R12 + narrow_oop_reg<<3 + offset]
3585         // NullCheck narrow_oop_reg
3586         //
3587         // On other platforms (Sparc) we have to keep new DecodeN node and
3588         // use it to do implicit NULL check in address:
3589         //
3590         // decode_not_null narrow_oop_reg, base_reg
3591         // [base_reg + offset]
3592         // NullCheck base_reg
3593         //
3594         // Pin the new DecodeN node to non-null path on these platform (Sparc)
3595         // to keep the information to which NULL check the new DecodeN node
3596         // corresponds to use it as value in implicit_null_check().
3597         //
3598         new_in1->set_req(0, n->in(0));
3599       }
3600 
3601       n->subsume_by(new_in1, this);
3602       if (in1->outcnt() == 0) {
3603         in1->disconnect_inputs(NULL, this);
3604       }
3605     } else {
3606       n->subsume_by(n->in(1), this);
3607       if (n->outcnt() == 0) {
3608         n->disconnect_inputs(NULL, this);
3609       }
3610     }
3611     break;
3612   }
3613 #ifdef _LP64
3614   case Op_CmpP:
3615     // Do this transformation here to preserve CmpPNode::sub() and
3616     // other TypePtr related Ideal optimizations (for example, ptr nullness).
3617     if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
3618       Node* in1 = n->in(1);
3619       Node* in2 = n->in(2);
3620       if (!in1->is_DecodeNarrowPtr()) {
3621         in2 = in1;
3622         in1 = n->in(2);
3623       }
3624       assert(in1->is_DecodeNarrowPtr(), "sanity");
3625 
3626       Node* new_in2 = NULL;
3627       if (in2->is_DecodeNarrowPtr()) {
3628         assert(in2->Opcode() == in1->Opcode(), "must be same node type");
3629         new_in2 = in2->in(1);
3630       } else if (in2->Opcode() == Op_ConP) {
3631         const Type* t = in2->bottom_type();
3632         if (t == TypePtr::NULL_PTR) {
3633           assert(in1->is_DecodeN(), "compare klass to null?");
3634           // Don't convert CmpP null check into CmpN if compressed
3635           // oops implicit null check is not generated.
3636           // This will allow to generate normal oop implicit null check.
3637           if (Matcher::gen_narrow_oop_implicit_null_checks())
3638             new_in2 = ConNode::make(TypeNarrowOop::NULL_PTR);
3639           //
3640           // This transformation together with CastPP transformation above
3641           // will generated code for implicit NULL checks for compressed oops.
3642           //
3643           // The original code after Optimize()
3644           //
3645           //    LoadN memory, narrow_oop_reg
3646           //    decode narrow_oop_reg, base_reg
3647           //    CmpP base_reg, NULL
3648           //    CastPP base_reg // NotNull
3649           //    Load [base_reg + offset], val_reg
3650           //
3651           // after these transformations will be
3652           //
3653           //    LoadN memory, narrow_oop_reg
3654           //    CmpN narrow_oop_reg, NULL
3655           //    decode_not_null narrow_oop_reg, base_reg
3656           //    Load [base_reg + offset], val_reg
3657           //
3658           // and the uncommon path (== NULL) will use narrow_oop_reg directly
3659           // since narrow oops can be used in debug info now (see the code in
3660           // final_graph_reshaping_walk()).
3661           //
3662           // At the end the code will be matched to
3663           // on x86:
3664           //
3665           //    Load_narrow_oop memory, narrow_oop_reg
3666           //    Load [R12 + narrow_oop_reg<<3 + offset], val_reg
3667           //    NullCheck narrow_oop_reg
3668           //
3669           // and on sparc:
3670           //
3671           //    Load_narrow_oop memory, narrow_oop_reg
3672           //    decode_not_null narrow_oop_reg, base_reg
3673           //    Load [base_reg + offset], val_reg
3674           //    NullCheck base_reg
3675           //
3676         } else if (t->isa_oopptr()) {
3677           new_in2 = ConNode::make(t->make_narrowoop());
3678         } else if (t->isa_klassptr()) {
3679           new_in2 = ConNode::make(t->make_narrowklass());
3680         }
3681       }
3682       if (new_in2 != NULL) {
3683         Node* cmpN = new CmpNNode(in1->in(1), new_in2);
3684         n->subsume_by(cmpN, this);
3685         if (in1->outcnt() == 0) {
3686           in1->disconnect_inputs(NULL, this);
3687         }
3688         if (in2->outcnt() == 0) {
3689           in2->disconnect_inputs(NULL, this);
3690         }
3691       }
3692     }
3693     break;
3694 
3695   case Op_DecodeN:
3696   case Op_DecodeNKlass:
3697     assert(!n->in(1)->is_EncodeNarrowPtr(), "should be optimized out");
3698     // DecodeN could be pinned when it can't be fold into
3699     // an address expression, see the code for Op_CastPP above.
3700     assert(n->in(0) == NULL || (UseCompressedOops && !Matcher::narrow_oop_use_complex_address()), "no control");
3701     break;
3702 
3703   case Op_EncodeP:
3704   case Op_EncodePKlass: {
3705     Node* in1 = n->in(1);
3706     if (in1->is_DecodeNarrowPtr()) {
3707       n->subsume_by(in1->in(1), this);
3708     } else if (in1->Opcode() == Op_ConP) {
3709       const Type* t = in1->bottom_type();
3710       if (t == TypePtr::NULL_PTR) {
3711         assert(t->isa_oopptr(), "null klass?");
3712         n->subsume_by(ConNode::make(TypeNarrowOop::NULL_PTR), this);
3713       } else if (t->isa_oopptr()) {
3714         n->subsume_by(ConNode::make(t->make_narrowoop()), this);
3715       } else if (t->isa_klassptr()) {
3716         n->subsume_by(ConNode::make(t->make_narrowklass()), this);
3717       }
3718     }
3719     if (in1->outcnt() == 0) {
3720       in1->disconnect_inputs(NULL, this);
3721     }
3722     break;
3723   }
3724 
3725   case Op_Proj: {
3726     if (OptimizeStringConcat) {
3727       ProjNode* p = n->as_Proj();
3728       if (p->_is_io_use) {
3729         // Separate projections were used for the exception path which
3730         // are normally removed by a late inline.  If it wasn't inlined
3731         // then they will hang around and should just be replaced with
3732         // the original one.
3733         Node* proj = NULL;
3734         // Replace with just one
3735         for (SimpleDUIterator i(p->in(0)); i.has_next(); i.next()) {
3736           Node *use = i.get();
3737           if (use->is_Proj() && p != use && use->as_Proj()->_con == p->_con) {
3738             proj = use;
3739             break;
3740           }
3741         }
3742         assert(proj != NULL || p->_con == TypeFunc::I_O, "io may be dropped at an infinite loop");
3743         if (proj != NULL) {
3744           p->subsume_by(proj, this);
3745         }
3746       }
3747     }
3748     break;
3749   }
3750 
3751   case Op_Phi:
3752     if (n->as_Phi()->bottom_type()->isa_narrowoop() || n->as_Phi()->bottom_type()->isa_narrowklass()) {
3753       // The EncodeP optimization may create Phi with the same edges
3754       // for all paths. It is not handled well by Register Allocator.
3755       Node* unique_in = n->in(1);
3756       assert(unique_in != NULL, "");
3757       uint cnt = n->req();
3758       for (uint i = 2; i < cnt; i++) {
3759         Node* m = n->in(i);
3760         assert(m != NULL, "");
3761         if (unique_in != m)
3762           unique_in = NULL;
3763       }
3764       if (unique_in != NULL) {
3765         n->subsume_by(unique_in, this);
3766       }
3767     }
3768     break;
3769 
3770 #endif
3771 
3772 #ifdef ASSERT
3773   case Op_CastII:
3774     // Verify that all range check dependent CastII nodes were removed.
3775     if (n->isa_CastII()->has_range_check()) {
3776       n->dump(3);
3777       assert(false, "Range check dependent CastII node was not removed");
3778     }
3779     break;
3780 #endif
3781 
3782   case Op_ModI:
3783     if (UseDivMod) {
3784       // Check if a%b and a/b both exist
3785       Node* d = n->find_similar(Op_DivI);
3786       if (d) {
3787         // Replace them with a fused divmod if supported
3788         if (Matcher::has_match_rule(Op_DivModI)) {
3789           DivModINode* divmod = DivModINode::make(n);
3790           d->subsume_by(divmod->div_proj(), this);
3791           n->subsume_by(divmod->mod_proj(), this);
3792         } else {
3793           // replace a%b with a-((a/b)*b)
3794           Node* mult = new MulINode(d, d->in(2));
3795           Node* sub  = new SubINode(d->in(1), mult);
3796           n->subsume_by(sub, this);
3797         }
3798       }
3799     }
3800     break;
3801 
3802   case Op_ModL:
3803     if (UseDivMod) {
3804       // Check if a%b and a/b both exist
3805       Node* d = n->find_similar(Op_DivL);
3806       if (d) {
3807         // Replace them with a fused divmod if supported
3808         if (Matcher::has_match_rule(Op_DivModL)) {
3809           DivModLNode* divmod = DivModLNode::make(n);
3810           d->subsume_by(divmod->div_proj(), this);
3811           n->subsume_by(divmod->mod_proj(), this);
3812         } else {
3813           // replace a%b with a-((a/b)*b)
3814           Node* mult = new MulLNode(d, d->in(2));
3815           Node* sub  = new SubLNode(d->in(1), mult);
3816           n->subsume_by(sub, this);
3817         }
3818       }
3819     }
3820     break;
3821 
3822   case Op_LoadVector:
3823   case Op_StoreVector:
3824     break;
3825 
3826   case Op_AddReductionVI:
3827   case Op_AddReductionVL:
3828   case Op_AddReductionVF:
3829   case Op_AddReductionVD:
3830   case Op_MulReductionVI:
3831   case Op_MulReductionVL:
3832   case Op_MulReductionVF:
3833   case Op_MulReductionVD:
3834   case Op_MinReductionV:
3835   case Op_MaxReductionV:
3836     break;
3837 
3838   case Op_PackB:
3839   case Op_PackS:
3840   case Op_PackI:
3841   case Op_PackF:
3842   case Op_PackL:
3843   case Op_PackD:
3844     if (n->req()-1 > 2) {
3845       // Replace many operand PackNodes with a binary tree for matching
3846       PackNode* p = (PackNode*) n;
3847       Node* btp = p->binary_tree_pack(1, n->req());
3848       n->subsume_by(btp, this);
3849     }
3850     break;
3851   case Op_Loop:
3852   case Op_CountedLoop:
3853   case Op_OuterStripMinedLoop:
3854     if (n->as_Loop()->is_inner_loop()) {
3855       frc.inc_inner_loop_count();
3856     }
3857     n->as_Loop()->verify_strip_mined(0);
3858     break;
3859   case Op_LShiftI:
3860   case Op_RShiftI:
3861   case Op_URShiftI:
3862   case Op_LShiftL:
3863   case Op_RShiftL:
3864   case Op_URShiftL:
3865     if (Matcher::need_masked_shift_count) {
3866       // The cpu's shift instructions don't restrict the count to the
3867       // lower 5/6 bits. We need to do the masking ourselves.
3868       Node* in2 = n->in(2);
3869       juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
3870       const TypeInt* t = in2->find_int_type();
3871       if (t != NULL && t->is_con()) {
3872         juint shift = t->get_con();
3873         if (shift > mask) { // Unsigned cmp
3874           n->set_req(2, ConNode::make(TypeInt::make(shift & mask)));
3875         }
3876       } else {
3877         if (t == NULL || t->_lo < 0 || t->_hi > (int)mask) {
3878           Node* shift = new AndINode(in2, ConNode::make(TypeInt::make(mask)));
3879           n->set_req(2, shift);
3880         }
3881       }
3882       if (in2->outcnt() == 0) { // Remove dead node
3883         in2->disconnect_inputs(NULL, this);
3884       }
3885     }
3886     break;
3887   case Op_MemBarStoreStore:
3888   case Op_MemBarRelease:
3889     // Break the link with AllocateNode: it is no longer useful and
3890     // confuses register allocation.
3891     if (n->req() > MemBarNode::Precedent) {
3892       n->set_req(MemBarNode::Precedent, top());
3893     }
3894     break;
3895   case Op_MemBarAcquire: {
3896     if (n->as_MemBar()->trailing_load() && n->req() > MemBarNode::Precedent) {
3897       // At parse time, the trailing MemBarAcquire for a volatile load
3898       // is created with an edge to the load. After optimizations,
3899       // that input may be a chain of Phis. If those phis have no
3900       // other use, then the MemBarAcquire keeps them alive and
3901       // register allocation can be confused.
3902       ResourceMark rm;
3903       Unique_Node_List wq;
3904       wq.push(n->in(MemBarNode::Precedent));
3905       n->set_req(MemBarNode::Precedent, top());
3906       while (wq.size() > 0) {
3907         Node* m = wq.pop();
3908         if (m->outcnt() == 0) {
3909           for (uint j = 0; j < m->req(); j++) {
3910             Node* in = m->in(j);
3911             if (in != NULL) {
3912               wq.push(in);
3913             }
3914           }
3915           m->disconnect_inputs(NULL, this);
3916         }
3917       }
3918     }
3919     break;
3920   }
3921   case Op_RangeCheck: {
3922     RangeCheckNode* rc = n->as_RangeCheck();
3923     Node* iff = new IfNode(rc->in(0), rc->in(1), rc->_prob, rc->_fcnt);
3924     n->subsume_by(iff, this);
3925     frc._tests.push(iff);
3926     break;
3927   }
3928   case Op_ConvI2L: {
3929     if (!Matcher::convi2l_type_required) {
3930       // Code generation on some platforms doesn't need accurate
3931       // ConvI2L types. Widening the type can help remove redundant
3932       // address computations.
3933       n->as_Type()->set_type(TypeLong::INT);
3934       ResourceMark rm;
3935       Node_List wq;
3936       wq.push(n);
3937       for (uint next = 0; next < wq.size(); next++) {
3938         Node *m = wq.at(next);
3939 
3940         for(;;) {
3941           // Loop over all nodes with identical inputs edges as m
3942           Node* k = m->find_similar(m->Opcode());
3943           if (k == NULL) {
3944             break;
3945           }
3946           // Push their uses so we get a chance to remove node made
3947           // redundant
3948           for (DUIterator_Fast imax, i = k->fast_outs(imax); i < imax; i++) {
3949             Node* u = k->fast_out(i);
3950             assert(!wq.contains(u), "shouldn't process one node several times");
3951             if (u->Opcode() == Op_LShiftL ||
3952                 u->Opcode() == Op_AddL ||
3953                 u->Opcode() == Op_SubL ||
3954                 u->Opcode() == Op_AddP) {
3955               wq.push(u);
3956             }
3957           }
3958           // Replace all nodes with identical edges as m with m
3959           k->subsume_by(m, this);
3960         }
3961       }
3962     }
3963     break;
3964   }
3965   case Op_CmpUL: {
3966     if (!Matcher::has_match_rule(Op_CmpUL)) {
3967       // No support for unsigned long comparisons
3968       ConINode* sign_pos = new ConINode(TypeInt::make(BitsPerLong - 1));
3969       Node* sign_bit_mask = new RShiftLNode(n->in(1), sign_pos);
3970       Node* orl = new OrLNode(n->in(1), sign_bit_mask);
3971       ConLNode* remove_sign_mask = new ConLNode(TypeLong::make(max_jlong));
3972       Node* andl = new AndLNode(orl, remove_sign_mask);
3973       Node* cmp = new CmpLNode(andl, n->in(2));
3974       n->subsume_by(cmp, this);
3975     }
3976     break;
3977   }
3978 #ifdef ASSERT
3979   case Op_ValueTypePtr:
3980   case Op_ValueType: {
3981     n->dump(-1);
3982     assert(false, "value type node was not removed");
3983     break;
3984   }
3985 #endif
3986   case Op_GetNullFreeProperty: {
3987     // Extract the null free bits
3988     uint last = unique();
3989     Node* null_free = NULL;
3990     if (n->in(1)->Opcode() == Op_LoadKlass) {
3991       Node* cast = new CastP2XNode(NULL, n->in(1));
3992       null_free = new AndLNode(cast, new ConLNode(TypeLong::make(((jlong)1)<<(oopDesc::wide_storage_props_shift + ArrayStorageProperties::null_free_bit))));
3993     } else {
3994       assert(n->in(1)->Opcode() == Op_LoadNKlass, "not a compressed klass?");
3995       Node* cast = new CastN2INode(n->in(1));
3996       null_free = new AndINode(cast, new ConINode(TypeInt::make(1<<(oopDesc::narrow_storage_props_shift + ArrayStorageProperties::null_free_bit))));
3997     }
3998     n->replace_by(null_free);
3999     break;
4000   }
4001   default:
4002     assert(!n->is_Call(), "");
4003     assert(!n->is_Mem(), "");
4004     assert(nop != Op_ProfileBoolean, "should be eliminated during IGVN");
4005     break;
4006   }
4007 }
4008 
4009 //------------------------------final_graph_reshaping_walk---------------------
4010 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
4011 // requires that the walk visits a node's inputs before visiting the node.
4012 void Compile::final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Reshape_Counts &frc ) {
4013   ResourceArea *area = Thread::current()->resource_area();
4014   Unique_Node_List sfpt(area);
4015 
4016   frc._visited.set(root->_idx); // first, mark node as visited
4017   uint cnt = root->req();
4018   Node *n = root;
4019   uint  i = 0;
4020   while (true) {
4021     if (i < cnt) {
4022       // Place all non-visited non-null inputs onto stack
4023       Node* m = n->in(i);
4024       ++i;
4025       if (m != NULL && !frc._visited.test_set(m->_idx)) {
4026         if (m->is_SafePoint() && m->as_SafePoint()->jvms() != NULL) {
4027           // compute worst case interpreter size in case of a deoptimization
4028           update_interpreter_frame_size(m->as_SafePoint()->jvms()->interpreter_frame_size());
4029 
4030           sfpt.push(m);
4031         }
4032         cnt = m->req();
4033         nstack.push(n, i); // put on stack parent and next input's index
4034         n = m;
4035         i = 0;
4036       }
4037     } else {
4038       // Now do post-visit work
4039       final_graph_reshaping_impl( n, frc );
4040       if (nstack.is_empty())
4041         break;             // finished
4042       n = nstack.node();   // Get node from stack
4043       cnt = n->req();
4044       i = nstack.index();
4045       nstack.pop();        // Shift to the next node on stack
4046     }
4047   }
4048 
4049   // Skip next transformation if compressed oops are not used.
4050   if ((UseCompressedOops && !Matcher::gen_narrow_oop_implicit_null_checks()) ||
4051       (!UseCompressedOops && !UseCompressedClassPointers))
4052     return;
4053 
4054   // Go over safepoints nodes to skip DecodeN/DecodeNKlass nodes for debug edges.
4055   // It could be done for an uncommon traps or any safepoints/calls
4056   // if the DecodeN/DecodeNKlass node is referenced only in a debug info.
4057   while (sfpt.size() > 0) {
4058     n = sfpt.pop();
4059     JVMState *jvms = n->as_SafePoint()->jvms();
4060     assert(jvms != NULL, "sanity");
4061     int start = jvms->debug_start();
4062     int end   = n->req();
4063     bool is_uncommon = (n->is_CallStaticJava() &&
4064                         n->as_CallStaticJava()->uncommon_trap_request() != 0);
4065     for (int j = start; j < end; j++) {
4066       Node* in = n->in(j);
4067       if (in->is_DecodeNarrowPtr()) {
4068         bool safe_to_skip = true;
4069         if (!is_uncommon ) {
4070           // Is it safe to skip?
4071           for (uint i = 0; i < in->outcnt(); i++) {
4072             Node* u = in->raw_out(i);
4073             if (!u->is_SafePoint() ||
4074                 (u->is_Call() && u->as_Call()->has_non_debug_use(n))) {
4075               safe_to_skip = false;
4076             }
4077           }
4078         }
4079         if (safe_to_skip) {
4080           n->set_req(j, in->in(1));
4081         }
4082         if (in->outcnt() == 0) {
4083           in->disconnect_inputs(NULL, this);
4084         }
4085       }
4086     }
4087   }
4088 }
4089 
4090 //------------------------------final_graph_reshaping--------------------------
4091 // Final Graph Reshaping.
4092 //
4093 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
4094 //     and not commoned up and forced early.  Must come after regular
4095 //     optimizations to avoid GVN undoing the cloning.  Clone constant
4096 //     inputs to Loop Phis; these will be split by the allocator anyways.
4097 //     Remove Opaque nodes.
4098 // (2) Move last-uses by commutative operations to the left input to encourage
4099 //     Intel update-in-place two-address operations and better register usage
4100 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
4101 //     calls canonicalizing them back.
4102 // (3) Count the number of double-precision FP ops, single-precision FP ops
4103 //     and call sites.  On Intel, we can get correct rounding either by
4104 //     forcing singles to memory (requires extra stores and loads after each
4105 //     FP bytecode) or we can set a rounding mode bit (requires setting and
4106 //     clearing the mode bit around call sites).  The mode bit is only used
4107 //     if the relative frequency of single FP ops to calls is low enough.
4108 //     This is a key transform for SPEC mpeg_audio.
4109 // (4) Detect infinite loops; blobs of code reachable from above but not
4110 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
4111 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
4112 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
4113 //     Detection is by looking for IfNodes where only 1 projection is
4114 //     reachable from below or CatchNodes missing some targets.
4115 // (5) Assert for insane oop offsets in debug mode.
4116 
4117 bool Compile::final_graph_reshaping() {
4118   // an infinite loop may have been eliminated by the optimizer,
4119   // in which case the graph will be empty.
4120   if (root()->req() == 1) {
4121     record_method_not_compilable("trivial infinite loop");
4122     return true;
4123   }
4124 
4125   // Expensive nodes have their control input set to prevent the GVN
4126   // from freely commoning them. There's no GVN beyond this point so
4127   // no need to keep the control input. We want the expensive nodes to
4128   // be freely moved to the least frequent code path by gcm.
4129   assert(OptimizeExpensiveOps || expensive_count() == 0, "optimization off but list non empty?");
4130   for (int i = 0; i < expensive_count(); i++) {
4131     _expensive_nodes->at(i)->set_req(0, NULL);
4132   }
4133 
4134   Final_Reshape_Counts frc;
4135 
4136   // Visit everybody reachable!
4137   // Allocate stack of size C->live_nodes()/2 to avoid frequent realloc
4138   Node_Stack nstack(live_nodes() >> 1);
4139   final_graph_reshaping_walk(nstack, root(), frc);
4140 
4141   // Check for unreachable (from below) code (i.e., infinite loops).
4142   for( uint i = 0; i < frc._tests.size(); i++ ) {
4143     MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
4144     // Get number of CFG targets.
4145     // Note that PCTables include exception targets after calls.
4146     uint required_outcnt = n->required_outcnt();
4147     if (n->outcnt() != required_outcnt) {
4148       // Check for a few special cases.  Rethrow Nodes never take the
4149       // 'fall-thru' path, so expected kids is 1 less.
4150       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
4151         if (n->in(0)->in(0)->is_Call()) {
4152           CallNode *call = n->in(0)->in(0)->as_Call();
4153           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
4154             required_outcnt--;      // Rethrow always has 1 less kid
4155           } else if (call->req() > TypeFunc::Parms &&
4156                      call->is_CallDynamicJava()) {
4157             // Check for null receiver. In such case, the optimizer has
4158             // detected that the virtual call will always result in a null
4159             // pointer exception. The fall-through projection of this CatchNode
4160             // will not be populated.
4161             Node *arg0 = call->in(TypeFunc::Parms);
4162             if (arg0->is_Type() &&
4163                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
4164               required_outcnt--;
4165             }
4166           } else if (call->entry_point() == OptoRuntime::new_array_Java() &&
4167                      call->req() > TypeFunc::Parms+1 &&
4168                      call->is_CallStaticJava()) {
4169             // Check for negative array length. In such case, the optimizer has
4170             // detected that the allocation attempt will always result in an
4171             // exception. There is no fall-through projection of this CatchNode .
4172             Node *arg1 = call->in(TypeFunc::Parms+1);
4173             if (arg1->is_Type() &&
4174                 arg1->as_Type()->type()->join(TypeInt::POS)->empty()) {
4175               required_outcnt--;
4176             }
4177           }
4178         }
4179       }
4180       // Recheck with a better notion of 'required_outcnt'
4181       if (n->outcnt() != required_outcnt) {
4182         record_method_not_compilable("malformed control flow");
4183         return true;            // Not all targets reachable!
4184       }
4185     }
4186     // Check that I actually visited all kids.  Unreached kids
4187     // must be infinite loops.
4188     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
4189       if (!frc._visited.test(n->fast_out(j)->_idx)) {
4190         record_method_not_compilable("infinite loop");
4191         return true;            // Found unvisited kid; must be unreach
4192       }
4193 
4194     // Here so verification code in final_graph_reshaping_walk()
4195     // always see an OuterStripMinedLoopEnd
4196     if (n->is_OuterStripMinedLoopEnd()) {
4197       IfNode* init_iff = n->as_If();
4198       Node* iff = new IfNode(init_iff->in(0), init_iff->in(1), init_iff->_prob, init_iff->_fcnt);
4199       n->subsume_by(iff, this);
4200     }
4201   }
4202 
4203   // If original bytecodes contained a mixture of floats and doubles
4204   // check if the optimizer has made it homogenous, item (3).
4205   if( Use24BitFPMode && Use24BitFP && UseSSE == 0 &&
4206       frc.get_float_count() > 32 &&
4207       frc.get_double_count() == 0 &&
4208       (10 * frc.get_call_count() < frc.get_float_count()) ) {
4209     set_24_bit_selection_and_mode( false,  true );
4210   }
4211 
4212   set_java_calls(frc.get_java_call_count());
4213   set_inner_loops(frc.get_inner_loop_count());
4214 
4215   // No infinite loops, no reason to bail out.
4216   return false;
4217 }
4218 
4219 //-----------------------------too_many_traps----------------------------------
4220 // Report if there are too many traps at the current method and bci.
4221 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
4222 bool Compile::too_many_traps(ciMethod* method,
4223                              int bci,
4224                              Deoptimization::DeoptReason reason) {
4225   ciMethodData* md = method->method_data();
4226   if (md->is_empty()) {
4227     // Assume the trap has not occurred, or that it occurred only
4228     // because of a transient condition during start-up in the interpreter.
4229     return false;
4230   }
4231   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
4232   if (md->has_trap_at(bci, m, reason) != 0) {
4233     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
4234     // Also, if there are multiple reasons, or if there is no per-BCI record,
4235     // assume the worst.
4236     if (log())
4237       log()->elem("observe trap='%s' count='%d'",
4238                   Deoptimization::trap_reason_name(reason),
4239                   md->trap_count(reason));
4240     return true;
4241   } else {
4242     // Ignore method/bci and see if there have been too many globally.
4243     return too_many_traps(reason, md);
4244   }
4245 }
4246 
4247 // Less-accurate variant which does not require a method and bci.
4248 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
4249                              ciMethodData* logmd) {
4250   if (trap_count(reason) >= Deoptimization::per_method_trap_limit(reason)) {
4251     // Too many traps globally.
4252     // Note that we use cumulative trap_count, not just md->trap_count.
4253     if (log()) {
4254       int mcount = (logmd == NULL)? -1: (int)logmd->trap_count(reason);
4255       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
4256                   Deoptimization::trap_reason_name(reason),
4257                   mcount, trap_count(reason));
4258     }
4259     return true;
4260   } else {
4261     // The coast is clear.
4262     return false;
4263   }
4264 }
4265 
4266 //--------------------------too_many_recompiles--------------------------------
4267 // Report if there are too many recompiles at the current method and bci.
4268 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
4269 // Is not eager to return true, since this will cause the compiler to use
4270 // Action_none for a trap point, to avoid too many recompilations.
4271 bool Compile::too_many_recompiles(ciMethod* method,
4272                                   int bci,
4273                                   Deoptimization::DeoptReason reason) {
4274   ciMethodData* md = method->method_data();
4275   if (md->is_empty()) {
4276     // Assume the trap has not occurred, or that it occurred only
4277     // because of a transient condition during start-up in the interpreter.
4278     return false;
4279   }
4280   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
4281   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
4282   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
4283   Deoptimization::DeoptReason per_bc_reason
4284     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
4285   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
4286   if ((per_bc_reason == Deoptimization::Reason_none
4287        || md->has_trap_at(bci, m, reason) != 0)
4288       // The trap frequency measure we care about is the recompile count:
4289       && md->trap_recompiled_at(bci, m)
4290       && md->overflow_recompile_count() >= bc_cutoff) {
4291     // Do not emit a trap here if it has already caused recompilations.
4292     // Also, if there are multiple reasons, or if there is no per-BCI record,
4293     // assume the worst.
4294     if (log())
4295       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
4296                   Deoptimization::trap_reason_name(reason),
4297                   md->trap_count(reason),
4298                   md->overflow_recompile_count());
4299     return true;
4300   } else if (trap_count(reason) != 0
4301              && decompile_count() >= m_cutoff) {
4302     // Too many recompiles globally, and we have seen this sort of trap.
4303     // Use cumulative decompile_count, not just md->decompile_count.
4304     if (log())
4305       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
4306                   Deoptimization::trap_reason_name(reason),
4307                   md->trap_count(reason), trap_count(reason),
4308                   md->decompile_count(), decompile_count());
4309     return true;
4310   } else {
4311     // The coast is clear.
4312     return false;
4313   }
4314 }
4315 
4316 // Compute when not to trap. Used by matching trap based nodes and
4317 // NullCheck optimization.
4318 void Compile::set_allowed_deopt_reasons() {
4319   _allowed_reasons = 0;
4320   if (is_method_compilation()) {
4321     for (int rs = (int)Deoptimization::Reason_none+1; rs < Compile::trapHistLength; rs++) {
4322       assert(rs < BitsPerInt, "recode bit map");
4323       if (!too_many_traps((Deoptimization::DeoptReason) rs)) {
4324         _allowed_reasons |= nth_bit(rs);
4325       }
4326     }
4327   }
4328 }
4329 
4330 bool Compile::needs_clinit_barrier(ciMethod* method, ciMethod* accessing_method) {
4331   return method->is_static() && needs_clinit_barrier(method->holder(), accessing_method);
4332 }
4333 
4334 bool Compile::needs_clinit_barrier(ciField* field, ciMethod* accessing_method) {
4335   return field->is_static() && needs_clinit_barrier(field->holder(), accessing_method);
4336 }
4337 
4338 bool Compile::needs_clinit_barrier(ciInstanceKlass* holder, ciMethod* accessing_method) {
4339   if (holder->is_initialized()) {
4340     return false;
4341   }
4342   if (holder->is_being_initialized()) {
4343     if (accessing_method->holder() == holder) {
4344       // Access inside a class. The barrier can be elided when access happens in <clinit>,
4345       // <init>, or a static method. In all those cases, there was an initialization
4346       // barrier on the holder klass passed.
4347       if (accessing_method->is_class_initializer() ||
4348           accessing_method->is_object_constructor() ||
4349           accessing_method->is_static()) {
4350         return false;
4351       }
4352     } else if (accessing_method->holder()->is_subclass_of(holder)) {
4353       // Access from a subclass. The barrier can be elided only when access happens in <clinit>.
4354       // In case of <init> or a static method, the barrier is on the subclass is not enough:
4355       // child class can become fully initialized while its parent class is still being initialized.
4356       if (accessing_method->is_class_initializer()) {
4357         return false;
4358       }
4359     }
4360     ciMethod* root = method(); // the root method of compilation
4361     if (root != accessing_method) {
4362       return needs_clinit_barrier(holder, root); // check access in the context of compilation root
4363     }
4364   }
4365   return true;
4366 }
4367 
4368 #ifndef PRODUCT
4369 //------------------------------verify_graph_edges---------------------------
4370 // Walk the Graph and verify that there is a one-to-one correspondence
4371 // between Use-Def edges and Def-Use edges in the graph.
4372 void Compile::verify_graph_edges(bool no_dead_code) {
4373   if (VerifyGraphEdges) {
4374     ResourceArea *area = Thread::current()->resource_area();
4375     Unique_Node_List visited(area);
4376     // Call recursive graph walk to check edges
4377     _root->verify_edges(visited);
4378     if (no_dead_code) {
4379       // Now make sure that no visited node is used by an unvisited node.
4380       bool dead_nodes = false;
4381       Unique_Node_List checked(area);
4382       while (visited.size() > 0) {
4383         Node* n = visited.pop();
4384         checked.push(n);
4385         for (uint i = 0; i < n->outcnt(); i++) {
4386           Node* use = n->raw_out(i);
4387           if (checked.member(use))  continue;  // already checked
4388           if (visited.member(use))  continue;  // already in the graph
4389           if (use->is_Con())        continue;  // a dead ConNode is OK
4390           // At this point, we have found a dead node which is DU-reachable.
4391           if (!dead_nodes) {
4392             tty->print_cr("*** Dead nodes reachable via DU edges:");
4393             dead_nodes = true;
4394           }
4395           use->dump(2);
4396           tty->print_cr("---");
4397           checked.push(use);  // No repeats; pretend it is now checked.
4398         }
4399       }
4400       assert(!dead_nodes, "using nodes must be reachable from root");
4401     }
4402   }
4403 }
4404 #endif
4405 
4406 // The Compile object keeps track of failure reasons separately from the ciEnv.
4407 // This is required because there is not quite a 1-1 relation between the
4408 // ciEnv and its compilation task and the Compile object.  Note that one
4409 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
4410 // to backtrack and retry without subsuming loads.  Other than this backtracking
4411 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
4412 // by the logic in C2Compiler.
4413 void Compile::record_failure(const char* reason) {
4414   if (log() != NULL) {
4415     log()->elem("failure reason='%s' phase='compile'", reason);
4416   }
4417   if (_failure_reason == NULL) {
4418     // Record the first failure reason.
4419     _failure_reason = reason;
4420   }
4421 
4422   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
4423     C->print_method(PHASE_FAILURE);
4424   }
4425   _root = NULL;  // flush the graph, too
4426 }
4427 
4428 Compile::TracePhase::TracePhase(const char* name, elapsedTimer* accumulator)
4429   : TraceTime(name, accumulator, CITime, CITimeVerbose),
4430     _phase_name(name), _dolog(CITimeVerbose)
4431 {
4432   if (_dolog) {
4433     C = Compile::current();
4434     _log = C->log();
4435   } else {
4436     C = NULL;
4437     _log = NULL;
4438   }
4439   if (_log != NULL) {
4440     _log->begin_head("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
4441     _log->stamp();
4442     _log->end_head();
4443   }
4444 }
4445 
4446 Compile::TracePhase::~TracePhase() {
4447 
4448   C = Compile::current();
4449   if (_dolog) {
4450     _log = C->log();
4451   } else {
4452     _log = NULL;
4453   }
4454 
4455 #ifdef ASSERT
4456   if (PrintIdealNodeCount) {
4457     tty->print_cr("phase name='%s' nodes='%d' live='%d' live_graph_walk='%d'",
4458                   _phase_name, C->unique(), C->live_nodes(), C->count_live_nodes_by_graph_walk());
4459   }
4460 
4461   if (VerifyIdealNodeCount) {
4462     Compile::current()->print_missing_nodes();
4463   }
4464 #endif
4465 
4466   if (_log != NULL) {
4467     _log->done("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
4468   }
4469 }
4470 
4471 //=============================================================================
4472 // Two Constant's are equal when the type and the value are equal.
4473 bool Compile::Constant::operator==(const Constant& other) {
4474   if (type()          != other.type()         )  return false;
4475   if (can_be_reused() != other.can_be_reused())  return false;
4476   // For floating point values we compare the bit pattern.
4477   switch (type()) {
4478   case T_INT:
4479   case T_FLOAT:   return (_v._value.i == other._v._value.i);
4480   case T_LONG:
4481   case T_DOUBLE:  return (_v._value.j == other._v._value.j);
4482   case T_OBJECT:
4483   case T_ADDRESS: return (_v._value.l == other._v._value.l);
4484   case T_VOID:    return (_v._value.l == other._v._value.l);  // jump-table entries
4485   case T_METADATA: return (_v._metadata == other._v._metadata);
4486   default: ShouldNotReachHere(); return false;
4487   }
4488 }
4489 
4490 static int type_to_size_in_bytes(BasicType t) {
4491   switch (t) {
4492   case T_INT:     return sizeof(jint   );
4493   case T_LONG:    return sizeof(jlong  );
4494   case T_FLOAT:   return sizeof(jfloat );
4495   case T_DOUBLE:  return sizeof(jdouble);
4496   case T_METADATA: return sizeof(Metadata*);
4497     // We use T_VOID as marker for jump-table entries (labels) which
4498     // need an internal word relocation.
4499   case T_VOID:
4500   case T_ADDRESS:
4501   case T_OBJECT:  return sizeof(jobject);
4502   default:
4503     ShouldNotReachHere();
4504     return -1;
4505   }
4506 }
4507 
4508 int Compile::ConstantTable::qsort_comparator(Constant* a, Constant* b) {
4509   // sort descending
4510   if (a->freq() > b->freq())  return -1;
4511   if (a->freq() < b->freq())  return  1;
4512   return 0;
4513 }
4514 
4515 void Compile::ConstantTable::calculate_offsets_and_size() {
4516   // First, sort the array by frequencies.
4517   _constants.sort(qsort_comparator);
4518 
4519 #ifdef ASSERT
4520   // Make sure all jump-table entries were sorted to the end of the
4521   // array (they have a negative frequency).
4522   bool found_void = false;
4523   for (int i = 0; i < _constants.length(); i++) {
4524     Constant con = _constants.at(i);
4525     if (con.type() == T_VOID)
4526       found_void = true;  // jump-tables
4527     else
4528       assert(!found_void, "wrong sorting");
4529   }
4530 #endif
4531 
4532   int offset = 0;
4533   for (int i = 0; i < _constants.length(); i++) {
4534     Constant* con = _constants.adr_at(i);
4535 
4536     // Align offset for type.
4537     int typesize = type_to_size_in_bytes(con->type());
4538     offset = align_up(offset, typesize);
4539     con->set_offset(offset);   // set constant's offset
4540 
4541     if (con->type() == T_VOID) {
4542       MachConstantNode* n = (MachConstantNode*) con->get_jobject();
4543       offset = offset + typesize * n->outcnt();  // expand jump-table
4544     } else {
4545       offset = offset + typesize;
4546     }
4547   }
4548 
4549   // Align size up to the next section start (which is insts; see
4550   // CodeBuffer::align_at_start).
4551   assert(_size == -1, "already set?");
4552   _size = align_up(offset, (int)CodeEntryAlignment);
4553 }
4554 
4555 void Compile::ConstantTable::emit(CodeBuffer& cb) {
4556   MacroAssembler _masm(&cb);
4557   for (int i = 0; i < _constants.length(); i++) {
4558     Constant con = _constants.at(i);
4559     address constant_addr = NULL;
4560     switch (con.type()) {
4561     case T_INT:    constant_addr = _masm.int_constant(   con.get_jint()   ); break;
4562     case T_LONG:   constant_addr = _masm.long_constant(  con.get_jlong()  ); break;
4563     case T_FLOAT:  constant_addr = _masm.float_constant( con.get_jfloat() ); break;
4564     case T_DOUBLE: constant_addr = _masm.double_constant(con.get_jdouble()); break;
4565     case T_OBJECT: {
4566       jobject obj = con.get_jobject();
4567       int oop_index = _masm.oop_recorder()->find_index(obj);
4568       constant_addr = _masm.address_constant((address) obj, oop_Relocation::spec(oop_index));
4569       break;
4570     }
4571     case T_ADDRESS: {
4572       address addr = (address) con.get_jobject();
4573       constant_addr = _masm.address_constant(addr);
4574       break;
4575     }
4576     // We use T_VOID as marker for jump-table entries (labels) which
4577     // need an internal word relocation.
4578     case T_VOID: {
4579       MachConstantNode* n = (MachConstantNode*) con.get_jobject();
4580       // Fill the jump-table with a dummy word.  The real value is
4581       // filled in later in fill_jump_table.
4582       address dummy = (address) n;
4583       constant_addr = _masm.address_constant(dummy);
4584       // Expand jump-table
4585       for (uint i = 1; i < n->outcnt(); i++) {
4586         address temp_addr = _masm.address_constant(dummy + i);
4587         assert(temp_addr, "consts section too small");
4588       }
4589       break;
4590     }
4591     case T_METADATA: {
4592       Metadata* obj = con.get_metadata();
4593       int metadata_index = _masm.oop_recorder()->find_index(obj);
4594       constant_addr = _masm.address_constant((address) obj, metadata_Relocation::spec(metadata_index));
4595       break;
4596     }
4597     default: ShouldNotReachHere();
4598     }
4599     assert(constant_addr, "consts section too small");
4600     assert((constant_addr - _masm.code()->consts()->start()) == con.offset(),
4601             "must be: %d == %d", (int) (constant_addr - _masm.code()->consts()->start()), (int)(con.offset()));
4602   }
4603 }
4604 
4605 int Compile::ConstantTable::find_offset(Constant& con) const {
4606   int idx = _constants.find(con);
4607   guarantee(idx != -1, "constant must be in constant table");
4608   int offset = _constants.at(idx).offset();
4609   guarantee(offset != -1, "constant table not emitted yet?");
4610   return offset;
4611 }
4612 
4613 void Compile::ConstantTable::add(Constant& con) {
4614   if (con.can_be_reused()) {
4615     int idx = _constants.find(con);
4616     if (idx != -1 && _constants.at(idx).can_be_reused()) {
4617       _constants.adr_at(idx)->inc_freq(con.freq());  // increase the frequency by the current value
4618       return;
4619     }
4620   }
4621   (void) _constants.append(con);
4622 }
4623 
4624 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, BasicType type, jvalue value) {
4625   Block* b = Compile::current()->cfg()->get_block_for_node(n);
4626   Constant con(type, value, b->_freq);
4627   add(con);
4628   return con;
4629 }
4630 
4631 Compile::Constant Compile::ConstantTable::add(Metadata* metadata) {
4632   Constant con(metadata);
4633   add(con);
4634   return con;
4635 }
4636 
4637 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, MachOper* oper) {
4638   jvalue value;
4639   BasicType type = oper->type()->basic_type();
4640   switch (type) {
4641   case T_LONG:    value.j = oper->constantL(); break;
4642   case T_FLOAT:   value.f = oper->constantF(); break;
4643   case T_DOUBLE:  value.d = oper->constantD(); break;
4644   case T_OBJECT:
4645   case T_ADDRESS: value.l = (jobject) oper->constant(); break;
4646   case T_METADATA: return add((Metadata*)oper->constant()); break;
4647   default: guarantee(false, "unhandled type: %s", type2name(type));
4648   }
4649   return add(n, type, value);
4650 }
4651 
4652 Compile::Constant Compile::ConstantTable::add_jump_table(MachConstantNode* n) {
4653   jvalue value;
4654   // We can use the node pointer here to identify the right jump-table
4655   // as this method is called from Compile::Fill_buffer right before
4656   // the MachNodes are emitted and the jump-table is filled (means the
4657   // MachNode pointers do not change anymore).
4658   value.l = (jobject) n;
4659   Constant con(T_VOID, value, next_jump_table_freq(), false);  // Labels of a jump-table cannot be reused.
4660   add(con);
4661   return con;
4662 }
4663 
4664 void Compile::ConstantTable::fill_jump_table(CodeBuffer& cb, MachConstantNode* n, GrowableArray<Label*> labels) const {
4665   // If called from Compile::scratch_emit_size do nothing.
4666   if (Compile::current()->in_scratch_emit_size())  return;
4667 
4668   assert(labels.is_nonempty(), "must be");
4669   assert((uint) labels.length() == n->outcnt(), "must be equal: %d == %d", labels.length(), n->outcnt());
4670 
4671   // Since MachConstantNode::constant_offset() also contains
4672   // table_base_offset() we need to subtract the table_base_offset()
4673   // to get the plain offset into the constant table.
4674   int offset = n->constant_offset() - table_base_offset();
4675 
4676   MacroAssembler _masm(&cb);
4677   address* jump_table_base = (address*) (_masm.code()->consts()->start() + offset);
4678 
4679   for (uint i = 0; i < n->outcnt(); i++) {
4680     address* constant_addr = &jump_table_base[i];
4681     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));
4682     *constant_addr = cb.consts()->target(*labels.at(i), (address) constant_addr);
4683     cb.consts()->relocate((address) constant_addr, relocInfo::internal_word_type);
4684   }
4685 }
4686 
4687 //----------------------------static_subtype_check-----------------------------
4688 // Shortcut important common cases when superklass is exact:
4689 // (0) superklass is java.lang.Object (can occur in reflective code)
4690 // (1) subklass is already limited to a subtype of superklass => always ok
4691 // (2) subklass does not overlap with superklass => always fail
4692 // (3) superklass has NO subtypes and we can check with a simple compare.
4693 int Compile::static_subtype_check(ciKlass* superk, ciKlass* subk) {
4694   if (StressReflectiveCode || superk == NULL || subk == NULL) {
4695     return SSC_full_test;       // Let caller generate the general case.
4696   }
4697 
4698   if (superk == env()->Object_klass()) {
4699     return SSC_always_true;     // (0) this test cannot fail
4700   }
4701 
4702   ciType* superelem = superk;
4703   if (superelem->is_array_klass()) {
4704     ciArrayKlass* ak = superelem->as_array_klass();
4705     superelem = superelem->as_array_klass()->base_element_type();
4706   }
4707 
4708   if (!subk->is_interface()) {  // cannot trust static interface types yet
4709     if (subk->is_subtype_of(superk)) {
4710       return SSC_always_true;   // (1) false path dead; no dynamic test needed
4711     }
4712     if (!(superelem->is_klass() && superelem->as_klass()->is_interface()) &&
4713         !superk->is_subtype_of(subk)) {
4714       return SSC_always_false;
4715     }
4716   }
4717 
4718   // Do not fold the subtype check to an array klass pointer comparison for [V? arrays.
4719   // [V is a subtype of [V? but the klass for [V is not equal to the klass for [V?. Perform a full test.
4720   if (superk->is_obj_array_klass() && !superk->as_array_klass()->storage_properties().is_null_free() && superk->as_array_klass()->element_klass()->is_valuetype()) {
4721     return SSC_full_test;
4722   }
4723   // If casting to an instance klass, it must have no subtypes
4724   if (superk->is_interface()) {
4725     // Cannot trust interfaces yet.
4726     // %%% S.B. superk->nof_implementors() == 1
4727   } else if (superelem->is_instance_klass()) {
4728     ciInstanceKlass* ik = superelem->as_instance_klass();
4729     if (!ik->has_subklass() && !ik->is_interface()) {
4730       if (!ik->is_final()) {
4731         // Add a dependency if there is a chance of a later subclass.
4732         dependencies()->assert_leaf_type(ik);
4733       }
4734       return SSC_easy_test;     // (3) caller can do a simple ptr comparison
4735     }
4736   } else {
4737     // A primitive array type has no subtypes.
4738     return SSC_easy_test;       // (3) caller can do a simple ptr comparison
4739   }
4740 
4741   return SSC_full_test;
4742 }
4743 
4744 Node* Compile::conv_I2X_index(PhaseGVN* phase, Node* idx, const TypeInt* sizetype, Node* ctrl) {
4745 #ifdef _LP64
4746   // The scaled index operand to AddP must be a clean 64-bit value.
4747   // Java allows a 32-bit int to be incremented to a negative
4748   // value, which appears in a 64-bit register as a large
4749   // positive number.  Using that large positive number as an
4750   // operand in pointer arithmetic has bad consequences.
4751   // On the other hand, 32-bit overflow is rare, and the possibility
4752   // can often be excluded, if we annotate the ConvI2L node with
4753   // a type assertion that its value is known to be a small positive
4754   // number.  (The prior range check has ensured this.)
4755   // This assertion is used by ConvI2LNode::Ideal.
4756   int index_max = max_jint - 1;  // array size is max_jint, index is one less
4757   if (sizetype != NULL) index_max = sizetype->_hi - 1;
4758   const TypeInt* iidxtype = TypeInt::make(0, index_max, Type::WidenMax);
4759   idx = constrained_convI2L(phase, idx, iidxtype, ctrl);
4760 #endif
4761   return idx;
4762 }
4763 
4764 // Convert integer value to a narrowed long type dependent on ctrl (for example, a range check)
4765 Node* Compile::constrained_convI2L(PhaseGVN* phase, Node* value, const TypeInt* itype, Node* ctrl) {
4766   if (ctrl != NULL) {
4767     // Express control dependency by a CastII node with a narrow type.
4768     value = new CastIINode(value, itype, false, true /* range check dependency */);
4769     // Make the CastII node dependent on the control input to prevent the narrowed ConvI2L
4770     // node from floating above the range check during loop optimizations. Otherwise, the
4771     // ConvI2L node may be eliminated independently of the range check, causing the data path
4772     // to become TOP while the control path is still there (although it's unreachable).
4773     value->set_req(0, ctrl);
4774     // Save CastII node to remove it after loop optimizations.
4775     phase->C->add_range_check_cast(value);
4776     value = phase->transform(value);
4777   }
4778   const TypeLong* ltype = TypeLong::make(itype->_lo, itype->_hi, itype->_widen);
4779   return phase->transform(new ConvI2LNode(value, ltype));
4780 }
4781 
4782 // The message about the current inlining is accumulated in
4783 // _print_inlining_stream and transfered into the _print_inlining_list
4784 // once we know whether inlining succeeds or not. For regular
4785 // inlining, messages are appended to the buffer pointed by
4786 // _print_inlining_idx in the _print_inlining_list. For late inlining,
4787 // a new buffer is added after _print_inlining_idx in the list. This
4788 // way we can update the inlining message for late inlining call site
4789 // when the inlining is attempted again.
4790 void Compile::print_inlining_init() {
4791   if (print_inlining() || print_intrinsics()) {
4792     _print_inlining_stream = new stringStream();
4793     _print_inlining_list = new (comp_arena())GrowableArray<PrintInliningBuffer>(comp_arena(), 1, 1, PrintInliningBuffer());
4794   }
4795 }
4796 
4797 void Compile::print_inlining_reinit() {
4798   if (print_inlining() || print_intrinsics()) {
4799     // Re allocate buffer when we change ResourceMark
4800     _print_inlining_stream = new stringStream();
4801   }
4802 }
4803 
4804 void Compile::print_inlining_reset() {
4805   _print_inlining_stream->reset();
4806 }
4807 
4808 void Compile::print_inlining_commit() {
4809   assert(print_inlining() || print_intrinsics(), "PrintInlining off?");
4810   // Transfer the message from _print_inlining_stream to the current
4811   // _print_inlining_list buffer and clear _print_inlining_stream.
4812   _print_inlining_list->at(_print_inlining_idx).ss()->write(_print_inlining_stream->as_string(), _print_inlining_stream->size());
4813   print_inlining_reset();
4814 }
4815 
4816 void Compile::print_inlining_push() {
4817   // Add new buffer to the _print_inlining_list at current position
4818   _print_inlining_idx++;
4819   _print_inlining_list->insert_before(_print_inlining_idx, PrintInliningBuffer());
4820 }
4821 
4822 Compile::PrintInliningBuffer& Compile::print_inlining_current() {
4823   return _print_inlining_list->at(_print_inlining_idx);
4824 }
4825 
4826 void Compile::print_inlining_update(CallGenerator* cg) {
4827   if (print_inlining() || print_intrinsics()) {
4828     if (!cg->is_late_inline()) {
4829       if (print_inlining_current().cg() != NULL) {
4830         print_inlining_push();
4831       }
4832       print_inlining_commit();
4833     } else {
4834       if (print_inlining_current().cg() != cg &&
4835           (print_inlining_current().cg() != NULL ||
4836            print_inlining_current().ss()->size() != 0)) {
4837         print_inlining_push();
4838       }
4839       print_inlining_commit();
4840       print_inlining_current().set_cg(cg);
4841     }
4842   }
4843 }
4844 
4845 void Compile::print_inlining_move_to(CallGenerator* cg) {
4846   // We resume inlining at a late inlining call site. Locate the
4847   // corresponding inlining buffer so that we can update it.
4848   if (print_inlining()) {
4849     for (int i = 0; i < _print_inlining_list->length(); i++) {
4850       if (_print_inlining_list->adr_at(i)->cg() == cg) {
4851         _print_inlining_idx = i;
4852         return;
4853       }
4854     }
4855     ShouldNotReachHere();
4856   }
4857 }
4858 
4859 void Compile::print_inlining_update_delayed(CallGenerator* cg) {
4860   if (print_inlining()) {
4861     assert(_print_inlining_stream->size() > 0, "missing inlining msg");
4862     assert(print_inlining_current().cg() == cg, "wrong entry");
4863     // replace message with new message
4864     _print_inlining_list->at_put(_print_inlining_idx, PrintInliningBuffer());
4865     print_inlining_commit();
4866     print_inlining_current().set_cg(cg);
4867   }
4868 }
4869 
4870 void Compile::print_inlining_assert_ready() {
4871   assert(!_print_inlining || _print_inlining_stream->size() == 0, "loosing data");
4872 }
4873 
4874 void Compile::process_print_inlining() {
4875   bool do_print_inlining = print_inlining() || print_intrinsics();
4876   if (do_print_inlining || log() != NULL) {
4877     // Print inlining message for candidates that we couldn't inline
4878     // for lack of space
4879     for (int i = 0; i < _late_inlines.length(); i++) {
4880       CallGenerator* cg = _late_inlines.at(i);
4881       if (!cg->is_mh_late_inline()) {
4882         const char* msg = "live nodes > LiveNodeCountInliningCutoff";
4883         if (do_print_inlining) {
4884           cg->print_inlining_late(msg);
4885         }
4886         log_late_inline_failure(cg, msg);
4887       }
4888     }
4889   }
4890   if (do_print_inlining) {
4891     ResourceMark rm;
4892     stringStream ss;
4893     for (int i = 0; i < _print_inlining_list->length(); i++) {
4894       ss.print("%s", _print_inlining_list->adr_at(i)->ss()->as_string());
4895     }
4896     size_t end = ss.size();
4897     _print_inlining_output = NEW_ARENA_ARRAY(comp_arena(), char, end+1);
4898     strncpy(_print_inlining_output, ss.base(), end+1);
4899     _print_inlining_output[end] = 0;
4900   }
4901 }
4902 
4903 void Compile::dump_print_inlining() {
4904   if (_print_inlining_output != NULL) {
4905     tty->print_raw(_print_inlining_output);
4906   }
4907 }
4908 
4909 void Compile::log_late_inline(CallGenerator* cg) {
4910   if (log() != NULL) {
4911     log()->head("late_inline method='%d'  inline_id='" JLONG_FORMAT "'", log()->identify(cg->method()),
4912                 cg->unique_id());
4913     JVMState* p = cg->call_node()->jvms();
4914     while (p != NULL) {
4915       log()->elem("jvms bci='%d' method='%d'", p->bci(), log()->identify(p->method()));
4916       p = p->caller();
4917     }
4918     log()->tail("late_inline");
4919   }
4920 }
4921 
4922 void Compile::log_late_inline_failure(CallGenerator* cg, const char* msg) {
4923   log_late_inline(cg);
4924   if (log() != NULL) {
4925     log()->inline_fail(msg);
4926   }
4927 }
4928 
4929 void Compile::log_inline_id(CallGenerator* cg) {
4930   if (log() != NULL) {
4931     // The LogCompilation tool needs a unique way to identify late
4932     // inline call sites. This id must be unique for this call site in
4933     // this compilation. Try to have it unique across compilations as
4934     // well because it can be convenient when grepping through the log
4935     // file.
4936     // Distinguish OSR compilations from others in case CICountOSR is
4937     // on.
4938     jlong id = ((jlong)unique()) + (((jlong)compile_id()) << 33) + (CICountOSR && is_osr_compilation() ? ((jlong)1) << 32 : 0);
4939     cg->set_unique_id(id);
4940     log()->elem("inline_id id='" JLONG_FORMAT "'", id);
4941   }
4942 }
4943 
4944 void Compile::log_inline_failure(const char* msg) {
4945   if (C->log() != NULL) {
4946     C->log()->inline_fail(msg);
4947   }
4948 }
4949 
4950 
4951 // Dump inlining replay data to the stream.
4952 // Don't change thread state and acquire any locks.
4953 void Compile::dump_inline_data(outputStream* out) {
4954   InlineTree* inl_tree = ilt();
4955   if (inl_tree != NULL) {
4956     out->print(" inline %d", inl_tree->count());
4957     inl_tree->dump_replay_data(out);
4958   }
4959 }
4960 
4961 int Compile::cmp_expensive_nodes(Node* n1, Node* n2) {
4962   if (n1->Opcode() < n2->Opcode())      return -1;
4963   else if (n1->Opcode() > n2->Opcode()) return 1;
4964 
4965   assert(n1->req() == n2->req(), "can't compare %s nodes: n1->req() = %d, n2->req() = %d", NodeClassNames[n1->Opcode()], n1->req(), n2->req());
4966   for (uint i = 1; i < n1->req(); i++) {
4967     if (n1->in(i) < n2->in(i))      return -1;
4968     else if (n1->in(i) > n2->in(i)) return 1;
4969   }
4970 
4971   return 0;
4972 }
4973 
4974 int Compile::cmp_expensive_nodes(Node** n1p, Node** n2p) {
4975   Node* n1 = *n1p;
4976   Node* n2 = *n2p;
4977 
4978   return cmp_expensive_nodes(n1, n2);
4979 }
4980 
4981 void Compile::sort_expensive_nodes() {
4982   if (!expensive_nodes_sorted()) {
4983     _expensive_nodes->sort(cmp_expensive_nodes);
4984   }
4985 }
4986 
4987 bool Compile::expensive_nodes_sorted() const {
4988   for (int i = 1; i < _expensive_nodes->length(); i++) {
4989     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i-1)) < 0) {
4990       return false;
4991     }
4992   }
4993   return true;
4994 }
4995 
4996 bool Compile::should_optimize_expensive_nodes(PhaseIterGVN &igvn) {
4997   if (_expensive_nodes->length() == 0) {
4998     return false;
4999   }
5000 
5001   assert(OptimizeExpensiveOps, "optimization off?");
5002 
5003   // Take this opportunity to remove dead nodes from the list
5004   int j = 0;
5005   for (int i = 0; i < _expensive_nodes->length(); i++) {
5006     Node* n = _expensive_nodes->at(i);
5007     if (!n->is_unreachable(igvn)) {
5008       assert(n->is_expensive(), "should be expensive");
5009       _expensive_nodes->at_put(j, n);
5010       j++;
5011     }
5012   }
5013   _expensive_nodes->trunc_to(j);
5014 
5015   // Then sort the list so that similar nodes are next to each other
5016   // and check for at least two nodes of identical kind with same data
5017   // inputs.
5018   sort_expensive_nodes();
5019 
5020   for (int i = 0; i < _expensive_nodes->length()-1; i++) {
5021     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i+1)) == 0) {
5022       return true;
5023     }
5024   }
5025 
5026   return false;
5027 }
5028 
5029 void Compile::cleanup_expensive_nodes(PhaseIterGVN &igvn) {
5030   if (_expensive_nodes->length() == 0) {
5031     return;
5032   }
5033 
5034   assert(OptimizeExpensiveOps, "optimization off?");
5035 
5036   // Sort to bring similar nodes next to each other and clear the
5037   // control input of nodes for which there's only a single copy.
5038   sort_expensive_nodes();
5039 
5040   int j = 0;
5041   int identical = 0;
5042   int i = 0;
5043   bool modified = false;
5044   for (; i < _expensive_nodes->length()-1; i++) {
5045     assert(j <= i, "can't write beyond current index");
5046     if (_expensive_nodes->at(i)->Opcode() == _expensive_nodes->at(i+1)->Opcode()) {
5047       identical++;
5048       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
5049       continue;
5050     }
5051     if (identical > 0) {
5052       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
5053       identical = 0;
5054     } else {
5055       Node* n = _expensive_nodes->at(i);
5056       igvn.replace_input_of(n, 0, NULL);
5057       igvn.hash_insert(n);
5058       modified = true;
5059     }
5060   }
5061   if (identical > 0) {
5062     _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
5063   } else if (_expensive_nodes->length() >= 1) {
5064     Node* n = _expensive_nodes->at(i);
5065     igvn.replace_input_of(n, 0, NULL);
5066     igvn.hash_insert(n);
5067     modified = true;
5068   }
5069   _expensive_nodes->trunc_to(j);
5070   if (modified) {
5071     igvn.optimize();
5072   }
5073 }
5074 
5075 void Compile::add_expensive_node(Node * n) {
5076   assert(!_expensive_nodes->contains(n), "duplicate entry in expensive list");
5077   assert(n->is_expensive(), "expensive nodes with non-null control here only");
5078   assert(!n->is_CFG() && !n->is_Mem(), "no cfg or memory nodes here");
5079   if (OptimizeExpensiveOps) {
5080     _expensive_nodes->append(n);
5081   } else {
5082     // Clear control input and let IGVN optimize expensive nodes if
5083     // OptimizeExpensiveOps is off.
5084     n->set_req(0, NULL);
5085   }
5086 }
5087 
5088 /**
5089  * Remove the speculative part of types and clean up the graph
5090  */
5091 void Compile::remove_speculative_types(PhaseIterGVN &igvn) {
5092   if (UseTypeSpeculation) {
5093     Unique_Node_List worklist;
5094     worklist.push(root());
5095     int modified = 0;
5096     // Go over all type nodes that carry a speculative type, drop the
5097     // speculative part of the type and enqueue the node for an igvn
5098     // which may optimize it out.
5099     for (uint next = 0; next < worklist.size(); ++next) {
5100       Node *n  = worklist.at(next);
5101       if (n->is_Type()) {
5102         TypeNode* tn = n->as_Type();
5103         const Type* t = tn->type();
5104         const Type* t_no_spec = t->remove_speculative();
5105         if (t_no_spec != t) {
5106           bool in_hash = igvn.hash_delete(n);
5107           assert(in_hash, "node should be in igvn hash table");
5108           tn->set_type(t_no_spec);
5109           igvn.hash_insert(n);
5110           igvn._worklist.push(n); // give it a chance to go away
5111           modified++;
5112         }
5113       }
5114       uint max = n->len();
5115       for( uint i = 0; i < max; ++i ) {
5116         Node *m = n->in(i);
5117         if (not_a_node(m))  continue;
5118         worklist.push(m);
5119       }
5120     }
5121     // Drop the speculative part of all types in the igvn's type table
5122     igvn.remove_speculative_types();
5123     if (modified > 0) {
5124       igvn.optimize();
5125     }
5126 #ifdef ASSERT
5127     // Verify that after the IGVN is over no speculative type has resurfaced
5128     worklist.clear();
5129     worklist.push(root());
5130     for (uint next = 0; next < worklist.size(); ++next) {
5131       Node *n  = worklist.at(next);
5132       const Type* t = igvn.type_or_null(n);
5133       assert((t == NULL) || (t == t->remove_speculative()), "no more speculative types");
5134       if (n->is_Type()) {
5135         t = n->as_Type()->type();
5136         assert(t == t->remove_speculative(), "no more speculative types");
5137       }
5138       uint max = n->len();
5139       for( uint i = 0; i < max; ++i ) {
5140         Node *m = n->in(i);
5141         if (not_a_node(m))  continue;
5142         worklist.push(m);
5143       }
5144     }
5145     igvn.check_no_speculative_types();
5146 #endif
5147   }
5148 }
5149 
5150 Node* Compile::optimize_acmp(PhaseGVN* phase, Node* a, Node* b) {
5151   const TypeInstPtr* ta = phase->type(a)->isa_instptr();
5152   const TypeInstPtr* tb = phase->type(b)->isa_instptr();
5153   if (!EnableValhalla || ta == NULL || tb == NULL ||
5154       ta->is_zero_type() || tb->is_zero_type() ||
5155       !ta->can_be_value_type() || !tb->can_be_value_type()) {
5156     // Use old acmp if one operand is null or not a value type
5157     return new CmpPNode(a, b);
5158   } else if (ta->is_valuetypeptr() || tb->is_valuetypeptr()) {
5159     // We know that one operand is a value type. Therefore,
5160     // new acmp will only return true if both operands are NULL.
5161     // Check if both operands are null by or'ing the oops.
5162     a = phase->transform(new CastP2XNode(NULL, a));
5163     b = phase->transform(new CastP2XNode(NULL, b));
5164     a = phase->transform(new OrXNode(a, b));
5165     return new CmpXNode(a, phase->MakeConX(0));
5166   }
5167   // Use new acmp
5168   return NULL;
5169 }
5170 
5171 // Auxiliary method to support randomized stressing/fuzzing.
5172 //
5173 // This method can be called the arbitrary number of times, with current count
5174 // as the argument. The logic allows selecting a single candidate from the
5175 // running list of candidates as follows:
5176 //    int count = 0;
5177 //    Cand* selected = null;
5178 //    while(cand = cand->next()) {
5179 //      if (randomized_select(++count)) {
5180 //        selected = cand;
5181 //      }
5182 //    }
5183 //
5184 // Including count equalizes the chances any candidate is "selected".
5185 // This is useful when we don't have the complete list of candidates to choose
5186 // from uniformly. In this case, we need to adjust the randomicity of the
5187 // selection, or else we will end up biasing the selection towards the latter
5188 // candidates.
5189 //
5190 // Quick back-envelope calculation shows that for the list of n candidates
5191 // the equal probability for the candidate to persist as "best" can be
5192 // achieved by replacing it with "next" k-th candidate with the probability
5193 // of 1/k. It can be easily shown that by the end of the run, the
5194 // probability for any candidate is converged to 1/n, thus giving the
5195 // uniform distribution among all the candidates.
5196 //
5197 // We don't care about the domain size as long as (RANDOMIZED_DOMAIN / count) is large.
5198 #define RANDOMIZED_DOMAIN_POW 29
5199 #define RANDOMIZED_DOMAIN (1 << RANDOMIZED_DOMAIN_POW)
5200 #define RANDOMIZED_DOMAIN_MASK ((1 << (RANDOMIZED_DOMAIN_POW + 1)) - 1)
5201 bool Compile::randomized_select(int count) {
5202   assert(count > 0, "only positive");
5203   return (os::random() & RANDOMIZED_DOMAIN_MASK) < (RANDOMIZED_DOMAIN / count);
5204 }
5205 
5206 CloneMap&     Compile::clone_map()                 { return _clone_map; }
5207 void          Compile::set_clone_map(Dict* d)      { _clone_map._dict = d; }
5208 
5209 void NodeCloneInfo::dump() const {
5210   tty->print(" {%d:%d} ", idx(), gen());
5211 }
5212 
5213 void CloneMap::clone(Node* old, Node* nnn, int gen) {
5214   uint64_t val = value(old->_idx);
5215   NodeCloneInfo cio(val);
5216   assert(val != 0, "old node should be in the map");
5217   NodeCloneInfo cin(cio.idx(), gen + cio.gen());
5218   insert(nnn->_idx, cin.get());
5219 #ifndef PRODUCT
5220   if (is_debug()) {
5221     tty->print_cr("CloneMap::clone inserted node %d info {%d:%d} into CloneMap", nnn->_idx, cin.idx(), cin.gen());
5222   }
5223 #endif
5224 }
5225 
5226 void CloneMap::verify_insert_and_clone(Node* old, Node* nnn, int gen) {
5227   NodeCloneInfo cio(value(old->_idx));
5228   if (cio.get() == 0) {
5229     cio.set(old->_idx, 0);
5230     insert(old->_idx, cio.get());
5231 #ifndef PRODUCT
5232     if (is_debug()) {
5233       tty->print_cr("CloneMap::verify_insert_and_clone inserted node %d info {%d:%d} into CloneMap", old->_idx, cio.idx(), cio.gen());
5234     }
5235 #endif
5236   }
5237   clone(old, nnn, gen);
5238 }
5239 
5240 int CloneMap::max_gen() const {
5241   int g = 0;
5242   DictI di(_dict);
5243   for(; di.test(); ++di) {
5244     int t = gen(di._key);
5245     if (g < t) {
5246       g = t;
5247 #ifndef PRODUCT
5248       if (is_debug()) {
5249         tty->print_cr("CloneMap::max_gen() update max=%d from %d", g, _2_node_idx_t(di._key));
5250       }
5251 #endif
5252     }
5253   }
5254   return g;
5255 }
5256 
5257 void CloneMap::dump(node_idx_t key) const {
5258   uint64_t val = value(key);
5259   if (val != 0) {
5260     NodeCloneInfo ni(val);
5261     ni.dump();
5262   }
5263 }
--- EOF ---