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   if(!((field->is_final() || field->is_stable()) == !atp->is_rewritable())) {
1948     ResourceMark rm;
1949     tty->print_cr("Problematic field: %s %s.%s",
1950         field->signature()->as_utf8(),
1951         field->holder()->name()->as_utf8(),
1952         field->name()->as_utf8());
1953     tty->print_cr("is_final = %d is_stable = %d is_rewritable = %d",
1954         field->is_final(), field->is_stable(), atp->is_rewritable());
1955   }
1956   assert((field->is_final() || field->is_stable()) == !atp->is_rewritable(), "must get the rewritable bits correct");
1957   return atp;
1958 }
1959 
1960 
1961 //------------------------------have_alias_type--------------------------------
1962 bool Compile::have_alias_type(const TypePtr* adr_type) {
1963   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1964   if (ace->_adr_type == adr_type) {
1965     return true;
1966   }
1967 
1968   // Handle special cases.
1969   if (adr_type == NULL)             return true;
1970   if (adr_type == TypePtr::BOTTOM)  return true;
1971 
1972   return find_alias_type(adr_type, true, NULL) != NULL;
1973 }
1974 
1975 //-----------------------------must_alias--------------------------------------
1976 // True if all values of the given address type are in the given alias category.
1977 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
1978   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1979   if (adr_type == NULL)                 return true;  // NULL serves as TypePtr::TOP
1980   if (alias_idx == AliasIdxTop)         return false; // the empty category
1981   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
1982 
1983   // the only remaining possible overlap is identity
1984   int adr_idx = get_alias_index(adr_type);
1985   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1986   assert(adr_idx == alias_idx ||
1987          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
1988           && adr_type                       != TypeOopPtr::BOTTOM),
1989          "should not be testing for overlap with an unsafe pointer");
1990   return adr_idx == alias_idx;
1991 }
1992 
1993 //------------------------------can_alias--------------------------------------
1994 // True if any values of the given address type are in the given alias category.
1995 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
1996   if (alias_idx == AliasIdxTop)         return false; // the empty category
1997   if (adr_type == NULL)                 return false; // NULL serves as TypePtr::TOP
1998   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1999   if (adr_type->base() == Type::AnyPtr) return true;  // TypePtr::BOTTOM or its twins
2000 
2001   // the only remaining possible overlap is identity
2002   int adr_idx = get_alias_index(adr_type);
2003   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
2004   return adr_idx == alias_idx;
2005 }
2006 
2007 
2008 
2009 //---------------------------pop_warm_call-------------------------------------
2010 WarmCallInfo* Compile::pop_warm_call() {
2011   WarmCallInfo* wci = _warm_calls;
2012   if (wci != NULL)  _warm_calls = wci->remove_from(wci);
2013   return wci;
2014 }
2015 
2016 //----------------------------Inline_Warm--------------------------------------
2017 int Compile::Inline_Warm() {
2018   // If there is room, try to inline some more warm call sites.
2019   // %%% Do a graph index compaction pass when we think we're out of space?
2020   if (!InlineWarmCalls)  return 0;
2021 
2022   int calls_made_hot = 0;
2023   int room_to_grow   = NodeCountInliningCutoff - unique();
2024   int amount_to_grow = MIN2(room_to_grow, (int)NodeCountInliningStep);
2025   int amount_grown   = 0;
2026   WarmCallInfo* call;
2027   while (amount_to_grow > 0 && (call = pop_warm_call()) != NULL) {
2028     int est_size = (int)call->size();
2029     if (est_size > (room_to_grow - amount_grown)) {
2030       // This one won't fit anyway.  Get rid of it.
2031       call->make_cold();
2032       continue;
2033     }
2034     call->make_hot();
2035     calls_made_hot++;
2036     amount_grown   += est_size;
2037     amount_to_grow -= est_size;
2038   }
2039 
2040   if (calls_made_hot > 0)  set_major_progress();
2041   return calls_made_hot;
2042 }
2043 
2044 
2045 //----------------------------Finish_Warm--------------------------------------
2046 void Compile::Finish_Warm() {
2047   if (!InlineWarmCalls)  return;
2048   if (failing())  return;
2049   if (warm_calls() == NULL)  return;
2050 
2051   // Clean up loose ends, if we are out of space for inlining.
2052   WarmCallInfo* call;
2053   while ((call = pop_warm_call()) != NULL) {
2054     call->make_cold();
2055   }
2056 }
2057 
2058 //---------------------cleanup_loop_predicates-----------------------
2059 // Remove the opaque nodes that protect the predicates so that all unused
2060 // checks and uncommon_traps will be eliminated from the ideal graph
2061 void Compile::cleanup_loop_predicates(PhaseIterGVN &igvn) {
2062   if (predicate_count()==0) return;
2063   for (int i = predicate_count(); i > 0; i--) {
2064     Node * n = predicate_opaque1_node(i-1);
2065     assert(n->Opcode() == Op_Opaque1, "must be");
2066     igvn.replace_node(n, n->in(1));
2067   }
2068   assert(predicate_count()==0, "should be clean!");
2069 }
2070 
2071 void Compile::add_range_check_cast(Node* n) {
2072   assert(n->isa_CastII()->has_range_check(), "CastII should have range check dependency");
2073   assert(!_range_check_casts->contains(n), "duplicate entry in range check casts");
2074   _range_check_casts->append(n);
2075 }
2076 
2077 // Remove all range check dependent CastIINodes.
2078 void Compile::remove_range_check_casts(PhaseIterGVN &igvn) {
2079   for (int i = range_check_cast_count(); i > 0; i--) {
2080     Node* cast = range_check_cast_node(i-1);
2081     assert(cast->isa_CastII()->has_range_check(), "CastII should have range check dependency");
2082     igvn.replace_node(cast, cast->in(1));
2083   }
2084   assert(range_check_cast_count() == 0, "should be empty");
2085 }
2086 
2087 void Compile::add_opaque4_node(Node* n) {
2088   assert(n->Opcode() == Op_Opaque4, "Opaque4 only");
2089   assert(!_opaque4_nodes->contains(n), "duplicate entry in Opaque4 list");
2090   _opaque4_nodes->append(n);
2091 }
2092 
2093 // Remove all Opaque4 nodes.
2094 void Compile::remove_opaque4_nodes(PhaseIterGVN &igvn) {
2095   for (int i = opaque4_count(); i > 0; i--) {
2096     Node* opaq = opaque4_node(i-1);
2097     assert(opaq->Opcode() == Op_Opaque4, "Opaque4 only");
2098     igvn.replace_node(opaq, opaq->in(2));
2099   }
2100   assert(opaque4_count() == 0, "should be empty");
2101 }
2102 
2103 void Compile::add_value_type(Node* n) {
2104   assert(n->is_ValueTypeBase(), "unexpected node");
2105   if (_value_type_nodes != NULL) {
2106     _value_type_nodes->push(n);
2107   }
2108 }
2109 
2110 void Compile::remove_value_type(Node* n) {
2111   assert(n->is_ValueTypeBase(), "unexpected node");
2112   if (_value_type_nodes != NULL) {
2113     _value_type_nodes->remove(n);
2114   }
2115 }
2116 
2117 // Does the return value keep otherwise useless value type allocations
2118 // alive?
2119 static bool return_val_keeps_allocations_alive(Node* ret_val) {
2120   ResourceMark rm;
2121   Unique_Node_List wq;
2122   wq.push(ret_val);
2123   bool some_allocations = false;
2124   for (uint i = 0; i < wq.size(); i++) {
2125     Node* n = wq.at(i);
2126     assert(!n->is_ValueTypeBase(), "chain of value type nodes");
2127     if (n->outcnt() > 1) {
2128       // Some other use for the allocation
2129       return false;
2130     } else if (n->is_Phi()) {
2131       for (uint j = 1; j < n->req(); j++) {
2132         wq.push(n->in(j));
2133       }
2134     } else if (n->is_CheckCastPP() &&
2135                n->in(1)->is_Proj() &&
2136                n->in(1)->in(0)->is_Allocate()) {
2137       some_allocations = true;
2138     }
2139   }
2140   return some_allocations;
2141 }
2142 
2143 void Compile::process_value_types(PhaseIterGVN &igvn) {
2144   // Make value types scalar in safepoints
2145   while (_value_type_nodes->size() != 0) {
2146     ValueTypeBaseNode* vt = _value_type_nodes->pop()->as_ValueTypeBase();
2147     vt->make_scalar_in_safepoints(&igvn);
2148     if (vt->is_ValueTypePtr()) {
2149       igvn.replace_node(vt, vt->get_oop());
2150     } else if (vt->outcnt() == 0) {
2151       igvn.remove_dead_node(vt);
2152     }
2153   }
2154   _value_type_nodes = NULL;
2155   if (tf()->returns_value_type_as_fields()) {
2156     Node* ret = NULL;
2157     for (uint i = 1; i < root()->req(); i++){
2158       Node* in = root()->in(i);
2159       if (in->Opcode() == Op_Return) {
2160         assert(ret == NULL, "only one return");
2161         ret = in;
2162       }
2163     }
2164     if (ret != NULL) {
2165       Node* ret_val = ret->in(TypeFunc::Parms);
2166       if (igvn.type(ret_val)->isa_oopptr() &&
2167           return_val_keeps_allocations_alive(ret_val)) {
2168         igvn.replace_input_of(ret, TypeFunc::Parms, ValueTypeNode::tagged_klass(igvn.type(ret_val)->value_klass(), igvn));
2169         assert(ret_val->outcnt() == 0, "should be dead now");
2170         igvn.remove_dead_node(ret_val);
2171       }
2172     }
2173   }
2174   igvn.optimize();
2175 }
2176 
2177 void Compile::adjust_flattened_array_access_aliases(PhaseIterGVN& igvn) {
2178   if (!_has_flattened_accesses) {
2179     return;
2180   }
2181   // Initially, all flattened array accesses share the same slice to
2182   // keep dependencies with Object[] array accesses (that could be
2183   // to a flattened array) correct. We're done with parsing so we
2184   // now know all flattened array accesses in this compile
2185   // unit. Let's move flattened array accesses to their own slice,
2186   // one per element field. This should help memory access
2187   // optimizations.
2188   ResourceMark rm;
2189   Unique_Node_List wq;
2190   wq.push(root());
2191 
2192   Node_List mergememnodes;
2193   Node_List memnodes;
2194 
2195   // Alias index currently shared by all flattened memory accesses
2196   int index = get_alias_index(TypeAryPtr::VALUES);
2197 
2198   // Find MergeMem nodes and flattened array accesses
2199   for (uint i = 0; i < wq.size(); i++) {
2200     Node* n = wq.at(i);
2201     if (n->is_Mem()) {
2202       const TypePtr* adr_type = NULL;
2203       if (n->Opcode() == Op_StoreCM) {
2204         adr_type = get_adr_type(get_alias_index(n->in(MemNode::OopStore)->adr_type()));
2205       } else {
2206         adr_type = get_adr_type(get_alias_index(n->adr_type()));
2207       }
2208       if (adr_type == TypeAryPtr::VALUES) {
2209         memnodes.push(n);
2210       }
2211     } else if (n->is_MergeMem()) {
2212       MergeMemNode* mm = n->as_MergeMem();
2213       if (mm->memory_at(index) != mm->base_memory()) {
2214         mergememnodes.push(n);
2215       }
2216     }
2217     for (uint j = 0; j < n->req(); j++) {
2218       Node* m = n->in(j);
2219       if (m != NULL) {
2220         wq.push(m);
2221       }
2222     }
2223   }
2224 
2225   if (memnodes.size() > 0) {
2226     _flattened_accesses_share_alias = false;
2227 
2228     // We are going to change the slice for the flattened array
2229     // accesses so we need to clear the cache entries that refer to
2230     // them.
2231     for (uint i = 0; i < AliasCacheSize; i++) {
2232       AliasCacheEntry* ace = &_alias_cache[i];
2233       if (ace->_adr_type != NULL &&
2234           ace->_adr_type->isa_aryptr() &&
2235           ace->_adr_type->is_aryptr()->elem()->isa_valuetype()) {
2236         ace->_adr_type = NULL;
2237         ace->_index = 0;
2238       }
2239     }
2240 
2241     // Find what aliases we are going to add
2242     int start_alias = num_alias_types()-1;
2243     int stop_alias = 0;
2244 
2245     for (uint i = 0; i < memnodes.size(); i++) {
2246       Node* m = memnodes.at(i);
2247       const TypePtr* adr_type = NULL;
2248       if (m->Opcode() == Op_StoreCM) {
2249         adr_type = m->in(MemNode::OopStore)->adr_type();
2250         Node* clone = new StoreCMNode(m->in(MemNode::Control), m->in(MemNode::Memory), m->in(MemNode::Address),
2251                                       m->adr_type(), m->in(MemNode::ValueIn), m->in(MemNode::OopStore),
2252                                       get_alias_index(adr_type));
2253         igvn.register_new_node_with_optimizer(clone);
2254         igvn.replace_node(m, clone);
2255       } else {
2256         adr_type = m->adr_type();
2257 #ifdef ASSERT
2258         m->as_Mem()->set_adr_type(adr_type);
2259 #endif
2260       }
2261       int idx = get_alias_index(adr_type);
2262       start_alias = MIN2(start_alias, idx);
2263       stop_alias = MAX2(stop_alias, idx);
2264     }
2265 
2266     assert(stop_alias >= start_alias, "should have expanded aliases");
2267 
2268     Node_Stack stack(0);
2269 #ifdef ASSERT
2270     VectorSet seen(Thread::current()->resource_area());
2271 #endif
2272     // Now let's fix the memory graph so each flattened array access
2273     // is moved to the right slice. Start from the MergeMem nodes.
2274     uint last = unique();
2275     for (uint i = 0; i < mergememnodes.size(); i++) {
2276       MergeMemNode* current = mergememnodes.at(i)->as_MergeMem();
2277       Node* n = current->memory_at(index);
2278       MergeMemNode* mm = NULL;
2279       do {
2280         // Follow memory edges through memory accesses, phis and
2281         // narrow membars and push nodes on the stack. Once we hit
2282         // bottom memory, we pop element off the stack one at a
2283         // time, in reverse order, and move them to the right slice
2284         // by changing their memory edges.
2285         if ((n->is_Phi() && n->adr_type() != TypePtr::BOTTOM) || n->is_Mem() || n->adr_type() == TypeAryPtr::VALUES) {
2286           assert(!seen.test_set(n->_idx), "");
2287           // Uses (a load for instance) will need to be moved to the
2288           // right slice as well and will get a new memory state
2289           // that we don't know yet. The use could also be the
2290           // backedge of a loop. We put a place holder node between
2291           // the memory node and its uses. We replace that place
2292           // holder with the correct memory state once we know it,
2293           // i.e. when nodes are popped off the stack. Using the
2294           // place holder make the logic work in the presence of
2295           // loops.
2296           if (n->outcnt() > 1) {
2297             Node* place_holder = NULL;
2298             assert(!n->has_out_with(Op_Node), "");
2299             for (DUIterator k = n->outs(); n->has_out(k); k++) {
2300               Node* u = n->out(k);
2301               if (u != current && u->_idx < last) {
2302                 bool success = false;
2303                 for (uint l = 0; l < u->req(); l++) {
2304                   if (!stack.is_empty() && u == stack.node() && l == stack.index()) {
2305                     continue;
2306                   }
2307                   Node* in = u->in(l);
2308                   if (in == n) {
2309                     if (place_holder == NULL) {
2310                       place_holder = new Node(1);
2311                       place_holder->init_req(0, n);
2312                     }
2313                     igvn.replace_input_of(u, l, place_holder);
2314                     success = true;
2315                   }
2316                 }
2317                 if (success) {
2318                   --k;
2319                 }
2320               }
2321             }
2322           }
2323           if (n->is_Phi()) {
2324             stack.push(n, 1);
2325             n = n->in(1);
2326           } else if (n->is_Mem()) {
2327             stack.push(n, n->req());
2328             n = n->in(MemNode::Memory);
2329           } else {
2330             assert(n->is_Proj() && n->in(0)->Opcode() == Op_MemBarCPUOrder, "");
2331             stack.push(n, n->req());
2332             n = n->in(0)->in(TypeFunc::Memory);
2333           }
2334         } else {
2335           assert(n->adr_type() == TypePtr::BOTTOM || (n->Opcode() == Op_Node && n->_idx >= last) || (n->is_Proj() && n->in(0)->is_Initialize()), "");
2336           // Build a new MergeMem node to carry the new memory state
2337           // as we build it. IGVN should fold extraneous MergeMem
2338           // nodes.
2339           mm = MergeMemNode::make(n);
2340           igvn.register_new_node_with_optimizer(mm);
2341           while (stack.size() > 0) {
2342             Node* m = stack.node();
2343             uint idx = stack.index();
2344             if (m->is_Mem()) {
2345               // Move memory node to its new slice
2346               const TypePtr* adr_type = m->adr_type();
2347               int alias = get_alias_index(adr_type);
2348               Node* prev = mm->memory_at(alias);
2349               igvn.replace_input_of(m, MemNode::Memory, prev);
2350               mm->set_memory_at(alias, m);
2351             } else if (m->is_Phi()) {
2352               // We need as many new phis as there are new aliases
2353               igvn.replace_input_of(m, idx, mm);
2354               if (idx == m->req()-1) {
2355                 Node* r = m->in(0);
2356                 for (uint j = (uint)start_alias; j <= (uint)stop_alias; j++) {
2357                   const Type* adr_type = get_adr_type(j);
2358                   if (!adr_type->isa_aryptr() || !adr_type->is_aryptr()->elem()->isa_valuetype()) {
2359                     continue;
2360                   }
2361                   Node* phi = new PhiNode(r, Type::MEMORY, get_adr_type(j));
2362                   igvn.register_new_node_with_optimizer(phi);
2363                   for (uint k = 1; k < m->req(); k++) {
2364                     phi->init_req(k, m->in(k)->as_MergeMem()->memory_at(j));
2365                   }
2366                   mm->set_memory_at(j, phi);
2367                 }
2368                 Node* base_phi = new PhiNode(r, Type::MEMORY, TypePtr::BOTTOM);
2369                 igvn.register_new_node_with_optimizer(base_phi);
2370                 for (uint k = 1; k < m->req(); k++) {
2371                   base_phi->init_req(k, m->in(k)->as_MergeMem()->base_memory());
2372                 }
2373                 mm->set_base_memory(base_phi);
2374               }
2375             } else {
2376               // This is a MemBarCPUOrder node from
2377               // Parse::array_load()/Parse::array_store(), in the
2378               // branch that handles flattened arrays hidden under
2379               // an Object[] array. We also need one new membar per
2380               // new alias to keep the unknown access that the
2381               // membars protect properly ordered with accesses to
2382               // known flattened array.
2383               assert(m->is_Proj(), "projection expected");
2384               Node* ctrl = m->in(0)->in(TypeFunc::Control);
2385               igvn.replace_input_of(m->in(0), TypeFunc::Control, top());
2386               for (uint j = (uint)start_alias; j <= (uint)stop_alias; j++) {
2387                 const Type* adr_type = get_adr_type(j);
2388                 if (!adr_type->isa_aryptr() || !adr_type->is_aryptr()->elem()->isa_valuetype()) {
2389                   continue;
2390                 }
2391                 MemBarNode* mb = new MemBarCPUOrderNode(this, j, NULL);
2392                 igvn.register_new_node_with_optimizer(mb);
2393                 Node* mem = mm->memory_at(j);
2394                 mb->init_req(TypeFunc::Control, ctrl);
2395                 mb->init_req(TypeFunc::Memory, mem);
2396                 ctrl = new ProjNode(mb, TypeFunc::Control);
2397                 igvn.register_new_node_with_optimizer(ctrl);
2398                 mem = new ProjNode(mb, TypeFunc::Memory);
2399                 igvn.register_new_node_with_optimizer(mem);
2400                 mm->set_memory_at(j, mem);
2401               }
2402               igvn.replace_node(m->in(0)->as_Multi()->proj_out(TypeFunc::Control), ctrl);
2403             }
2404             if (idx < m->req()-1) {
2405               idx += 1;
2406               stack.set_index(idx);
2407               n = m->in(idx);
2408               break;
2409             }
2410             // Take care of place holder nodes
2411             if (m->has_out_with(Op_Node)) {
2412               Node* place_holder = m->find_out_with(Op_Node);
2413               if (place_holder != NULL) {
2414                 Node* mm_clone = mm->clone();
2415                 igvn.register_new_node_with_optimizer(mm_clone);
2416                 Node* hook = new Node(1);
2417                 hook->init_req(0, mm);
2418                 igvn.replace_node(place_holder, mm_clone);
2419                 hook->destruct();
2420               }
2421               assert(!m->has_out_with(Op_Node), "place holder should be gone now");
2422             }
2423             stack.pop();
2424           }
2425         }
2426       } while(stack.size() > 0);
2427       // Fix the memory state at the MergeMem we started from
2428       igvn.rehash_node_delayed(current);
2429       for (uint j = (uint)start_alias; j <= (uint)stop_alias; j++) {
2430         const Type* adr_type = get_adr_type(j);
2431         if (!adr_type->isa_aryptr() || !adr_type->is_aryptr()->elem()->isa_valuetype()) {
2432           continue;
2433         }
2434         current->set_memory_at(j, mm);
2435       }
2436       current->set_memory_at(index, current->base_memory());
2437     }
2438     igvn.optimize();
2439   }
2440   print_method(PHASE_SPLIT_VALUES_ARRAY, 2);
2441 }
2442 
2443 
2444 // StringOpts and late inlining of string methods
2445 void Compile::inline_string_calls(bool parse_time) {
2446   {
2447     // remove useless nodes to make the usage analysis simpler
2448     ResourceMark rm;
2449     PhaseRemoveUseless pru(initial_gvn(), for_igvn());
2450   }
2451 
2452   {
2453     ResourceMark rm;
2454     print_method(PHASE_BEFORE_STRINGOPTS, 3);
2455     PhaseStringOpts pso(initial_gvn(), for_igvn());
2456     print_method(PHASE_AFTER_STRINGOPTS, 3);
2457   }
2458 
2459   // now inline anything that we skipped the first time around
2460   if (!parse_time) {
2461     _late_inlines_pos = _late_inlines.length();
2462   }
2463 
2464   while (_string_late_inlines.length() > 0) {
2465     CallGenerator* cg = _string_late_inlines.pop();
2466     cg->do_late_inline();
2467     if (failing())  return;
2468   }
2469   _string_late_inlines.trunc_to(0);
2470 }
2471 
2472 // Late inlining of boxing methods
2473 void Compile::inline_boxing_calls(PhaseIterGVN& igvn) {
2474   if (_boxing_late_inlines.length() > 0) {
2475     assert(has_boxed_value(), "inconsistent");
2476 
2477     PhaseGVN* gvn = initial_gvn();
2478     set_inlining_incrementally(true);
2479 
2480     assert( igvn._worklist.size() == 0, "should be done with igvn" );
2481     for_igvn()->clear();
2482     gvn->replace_with(&igvn);
2483 
2484     _late_inlines_pos = _late_inlines.length();
2485 
2486     while (_boxing_late_inlines.length() > 0) {
2487       CallGenerator* cg = _boxing_late_inlines.pop();
2488       cg->do_late_inline();
2489       if (failing())  return;
2490     }
2491     _boxing_late_inlines.trunc_to(0);
2492 
2493     inline_incrementally_cleanup(igvn);
2494 
2495     set_inlining_incrementally(false);
2496   }
2497 }
2498 
2499 bool Compile::inline_incrementally_one() {
2500   assert(IncrementalInline, "incremental inlining should be on");
2501 
2502   TracePhase tp("incrementalInline_inline", &timers[_t_incrInline_inline]);
2503   set_inlining_progress(false);
2504   set_do_cleanup(false);
2505   int i = 0;
2506   for (; i <_late_inlines.length() && !inlining_progress(); i++) {
2507     CallGenerator* cg = _late_inlines.at(i);
2508     _late_inlines_pos = i+1;
2509     cg->do_late_inline();
2510     if (failing())  return false;
2511   }
2512   int j = 0;
2513   for (; i < _late_inlines.length(); i++, j++) {
2514     _late_inlines.at_put(j, _late_inlines.at(i));
2515   }
2516   _late_inlines.trunc_to(j);
2517   assert(inlining_progress() || _late_inlines.length() == 0, "");
2518 
2519   bool needs_cleanup = do_cleanup() || over_inlining_cutoff();
2520 
2521   set_inlining_progress(false);
2522   set_do_cleanup(false);
2523   return (_late_inlines.length() > 0) && !needs_cleanup;
2524 }
2525 
2526 void Compile::inline_incrementally_cleanup(PhaseIterGVN& igvn) {
2527   {
2528     TracePhase tp("incrementalInline_pru", &timers[_t_incrInline_pru]);
2529     ResourceMark rm;
2530     PhaseRemoveUseless pru(initial_gvn(), for_igvn());
2531   }
2532   {
2533     TracePhase tp("incrementalInline_igvn", &timers[_t_incrInline_igvn]);
2534     igvn = PhaseIterGVN(initial_gvn());
2535     igvn.optimize();
2536   }
2537 }
2538 
2539 // Perform incremental inlining until bound on number of live nodes is reached
2540 void Compile::inline_incrementally(PhaseIterGVN& igvn) {
2541   TracePhase tp("incrementalInline", &timers[_t_incrInline]);
2542 
2543   set_inlining_incrementally(true);
2544   uint low_live_nodes = 0;
2545 
2546   while (_late_inlines.length() > 0) {
2547     if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2548       if (low_live_nodes < (uint)LiveNodeCountInliningCutoff * 8 / 10) {
2549         TracePhase tp("incrementalInline_ideal", &timers[_t_incrInline_ideal]);
2550         // PhaseIdealLoop is expensive so we only try it once we are
2551         // out of live nodes and we only try it again if the previous
2552         // helped got the number of nodes down significantly
2553         PhaseIdealLoop::optimize(igvn, LoopOptsNone);
2554         if (failing())  return;
2555         low_live_nodes = live_nodes();
2556         _major_progress = true;
2557       }
2558 
2559       if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2560         break; // finish
2561       }
2562     }
2563 
2564     for_igvn()->clear();
2565     initial_gvn()->replace_with(&igvn);
2566 
2567     while (inline_incrementally_one()) {
2568       assert(!failing(), "inconsistent");
2569     }
2570 
2571     if (failing())  return;
2572 
2573     inline_incrementally_cleanup(igvn);
2574 
2575     if (failing())  return;
2576   }
2577   assert( igvn._worklist.size() == 0, "should be done with igvn" );
2578 
2579   if (_string_late_inlines.length() > 0) {
2580     assert(has_stringbuilder(), "inconsistent");
2581     for_igvn()->clear();
2582     initial_gvn()->replace_with(&igvn);
2583 
2584     inline_string_calls(false);
2585 
2586     if (failing())  return;
2587 
2588     inline_incrementally_cleanup(igvn);
2589   }
2590 
2591   set_inlining_incrementally(false);
2592 }
2593 
2594 
2595 bool Compile::optimize_loops(PhaseIterGVN& igvn, LoopOptsMode mode) {
2596   if(_loop_opts_cnt > 0) {
2597     debug_only( int cnt = 0; );
2598     while(major_progress() && (_loop_opts_cnt > 0)) {
2599       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2600       assert( cnt++ < 40, "infinite cycle in loop optimization" );
2601       PhaseIdealLoop::optimize(igvn, mode);
2602       _loop_opts_cnt--;
2603       if (failing())  return false;
2604       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
2605     }
2606   }
2607   return true;
2608 }
2609 
2610 // Remove edges from "root" to each SafePoint at a backward branch.
2611 // They were inserted during parsing (see add_safepoint()) to make
2612 // infinite loops without calls or exceptions visible to root, i.e.,
2613 // useful.
2614 void Compile::remove_root_to_sfpts_edges(PhaseIterGVN& igvn) {
2615   Node *r = root();
2616   if (r != NULL) {
2617     for (uint i = r->req(); i < r->len(); ++i) {
2618       Node *n = r->in(i);
2619       if (n != NULL && n->is_SafePoint()) {
2620         r->rm_prec(i);
2621         if (n->outcnt() == 0) {
2622           igvn.remove_dead_node(n);
2623         }
2624         --i;
2625       }
2626     }
2627   }
2628 }
2629 
2630 //------------------------------Optimize---------------------------------------
2631 // Given a graph, optimize it.
2632 void Compile::Optimize() {
2633   TracePhase tp("optimizer", &timers[_t_optimizer]);
2634 
2635 #ifndef PRODUCT
2636   if (_directive->BreakAtCompileOption) {
2637     BREAKPOINT;
2638   }
2639 
2640 #endif
2641 
2642   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
2643 #ifdef ASSERT
2644   bs->verify_gc_barriers(this, BarrierSetC2::BeforeOptimize);
2645 #endif
2646 
2647   ResourceMark rm;
2648 
2649   print_inlining_reinit();
2650 
2651   NOT_PRODUCT( verify_graph_edges(); )
2652 
2653   print_method(PHASE_AFTER_PARSING);
2654 
2655  {
2656   // Iterative Global Value Numbering, including ideal transforms
2657   // Initialize IterGVN with types and values from parse-time GVN
2658   PhaseIterGVN igvn(initial_gvn());
2659 #ifdef ASSERT
2660   _modified_nodes = new (comp_arena()) Unique_Node_List(comp_arena());
2661 #endif
2662   {
2663     TracePhase tp("iterGVN", &timers[_t_iterGVN]);
2664     igvn.optimize();
2665   }
2666 
2667   if (failing())  return;
2668 
2669   print_method(PHASE_ITER_GVN1, 2);
2670 
2671   inline_incrementally(igvn);
2672 
2673   print_method(PHASE_INCREMENTAL_INLINE, 2);
2674 
2675   if (failing())  return;
2676 
2677   if (eliminate_boxing()) {
2678     // Inline valueOf() methods now.
2679     inline_boxing_calls(igvn);
2680 
2681     if (AlwaysIncrementalInline) {
2682       inline_incrementally(igvn);
2683     }
2684 
2685     print_method(PHASE_INCREMENTAL_BOXING_INLINE, 2);
2686 
2687     if (failing())  return;
2688   }
2689 
2690   // Now that all inlining is over, cut edge from root to loop
2691   // safepoints
2692   remove_root_to_sfpts_edges(igvn);
2693 
2694   // Remove the speculative part of types and clean up the graph from
2695   // the extra CastPP nodes whose only purpose is to carry them. Do
2696   // that early so that optimizations are not disrupted by the extra
2697   // CastPP nodes.
2698   remove_speculative_types(igvn);
2699 
2700   // No more new expensive nodes will be added to the list from here
2701   // so keep only the actual candidates for optimizations.
2702   cleanup_expensive_nodes(igvn);
2703 
2704   if (!failing() && RenumberLiveNodes && live_nodes() + NodeLimitFudgeFactor < unique()) {
2705     Compile::TracePhase tp("", &timers[_t_renumberLive]);
2706     initial_gvn()->replace_with(&igvn);
2707     for_igvn()->clear();
2708     Unique_Node_List new_worklist(C->comp_arena());
2709     {
2710       ResourceMark rm;
2711       PhaseRenumberLive prl = PhaseRenumberLive(initial_gvn(), for_igvn(), &new_worklist);
2712     }
2713     set_for_igvn(&new_worklist);
2714     igvn = PhaseIterGVN(initial_gvn());
2715     igvn.optimize();
2716   }
2717 
2718   if (_value_type_nodes->size() > 0) {
2719     // Do this once all inlining is over to avoid getting inconsistent debug info
2720     process_value_types(igvn);
2721   }
2722 
2723   adjust_flattened_array_access_aliases(igvn);
2724 
2725   // Perform escape analysis
2726   if (_do_escape_analysis && ConnectionGraph::has_candidates(this)) {
2727     if (has_loops()) {
2728       // Cleanup graph (remove dead nodes).
2729       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2730       PhaseIdealLoop::optimize(igvn, LoopOptsNone);
2731       if (major_progress()) print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
2732       if (failing())  return;
2733     }
2734     ConnectionGraph::do_analysis(this, &igvn);
2735 
2736     if (failing())  return;
2737 
2738     // Optimize out fields loads from scalar replaceable allocations.
2739     igvn.optimize();
2740     print_method(PHASE_ITER_GVN_AFTER_EA, 2);
2741 
2742     if (failing())  return;
2743 
2744     if (congraph() != NULL && macro_count() > 0) {
2745       TracePhase tp("macroEliminate", &timers[_t_macroEliminate]);
2746       PhaseMacroExpand mexp(igvn);
2747       mexp.eliminate_macro_nodes();
2748       igvn.set_delay_transform(false);
2749 
2750       igvn.optimize();
2751       print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
2752 
2753       if (failing())  return;
2754     }
2755   }
2756 
2757   // Loop transforms on the ideal graph.  Range Check Elimination,
2758   // peeling, unrolling, etc.
2759 
2760   // Set loop opts counter
2761   if((_loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
2762     {
2763       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2764       PhaseIdealLoop::optimize(igvn, LoopOptsDefault);
2765       _loop_opts_cnt--;
2766       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP1, 2);
2767       if (failing())  return;
2768     }
2769     // Loop opts pass if partial peeling occurred in previous pass
2770     if(PartialPeelLoop && major_progress() && (_loop_opts_cnt > 0)) {
2771       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2772       PhaseIdealLoop::optimize(igvn, LoopOptsSkipSplitIf);
2773       _loop_opts_cnt--;
2774       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP2, 2);
2775       if (failing())  return;
2776     }
2777     // Loop opts pass for loop-unrolling before CCP
2778     if(major_progress() && (_loop_opts_cnt > 0)) {
2779       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2780       PhaseIdealLoop::optimize(igvn, LoopOptsSkipSplitIf);
2781       _loop_opts_cnt--;
2782       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP3, 2);
2783     }
2784     if (!failing()) {
2785       // Verify that last round of loop opts produced a valid graph
2786       TracePhase tp("idealLoopVerify", &timers[_t_idealLoopVerify]);
2787       PhaseIdealLoop::verify(igvn);
2788     }
2789   }
2790   if (failing())  return;
2791 
2792   // Conditional Constant Propagation;
2793   PhaseCCP ccp( &igvn );
2794   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
2795   {
2796     TracePhase tp("ccp", &timers[_t_ccp]);
2797     ccp.do_transform();
2798   }
2799   print_method(PHASE_CPP1, 2);
2800 
2801   assert( true, "Break here to ccp.dump_old2new_map()");
2802 
2803   // Iterative Global Value Numbering, including ideal transforms
2804   {
2805     TracePhase tp("iterGVN2", &timers[_t_iterGVN2]);
2806     igvn = ccp;
2807     igvn.optimize();
2808   }
2809   print_method(PHASE_ITER_GVN2, 2);
2810 
2811   if (failing())  return;
2812 
2813   // Loop transforms on the ideal graph.  Range Check Elimination,
2814   // peeling, unrolling, etc.
2815   if (!optimize_loops(igvn, LoopOptsDefault)) {
2816     return;
2817   }
2818 
2819   if (failing())  return;
2820 
2821   // Ensure that major progress is now clear
2822   C->clear_major_progress();
2823 
2824   {
2825     // Verify that all previous optimizations produced a valid graph
2826     // at least to this point, even if no loop optimizations were done.
2827     TracePhase tp("idealLoopVerify", &timers[_t_idealLoopVerify]);
2828     PhaseIdealLoop::verify(igvn);
2829   }
2830 
2831   if (range_check_cast_count() > 0) {
2832     // No more loop optimizations. Remove all range check dependent CastIINodes.
2833     C->remove_range_check_casts(igvn);
2834     igvn.optimize();
2835   }
2836 
2837 #ifdef ASSERT
2838   bs->verify_gc_barriers(this, BarrierSetC2::BeforeLateInsertion);
2839 #endif
2840 
2841   bs->barrier_insertion_phase(C, igvn);
2842   if (failing())  return;
2843 
2844 #ifdef ASSERT
2845   bs->verify_gc_barriers(this, BarrierSetC2::BeforeMacroExpand);
2846 #endif
2847 
2848   {
2849     TracePhase tp("macroExpand", &timers[_t_macroExpand]);
2850     PhaseMacroExpand  mex(igvn);
2851     if (mex.expand_macro_nodes()) {
2852       assert(failing(), "must bail out w/ explicit message");
2853       return;
2854     }
2855     print_method(PHASE_MACRO_EXPANSION, 2);
2856   }
2857 
2858   {
2859     TracePhase tp("barrierExpand", &timers[_t_barrierExpand]);
2860     if (bs->expand_barriers(this, igvn)) {
2861       assert(failing(), "must bail out w/ explicit message");
2862       return;
2863     }
2864     print_method(PHASE_BARRIER_EXPANSION, 2);
2865   }
2866 
2867   if (opaque4_count() > 0) {
2868     C->remove_opaque4_nodes(igvn);
2869     igvn.optimize();
2870   }
2871 
2872   DEBUG_ONLY( _modified_nodes = NULL; )
2873  } // (End scope of igvn; run destructor if necessary for asserts.)
2874 
2875  process_print_inlining();
2876  // A method with only infinite loops has no edges entering loops from root
2877  {
2878    TracePhase tp("graphReshape", &timers[_t_graphReshaping]);
2879    if (final_graph_reshaping()) {
2880      assert(failing(), "must bail out w/ explicit message");
2881      return;
2882    }
2883  }
2884 
2885  print_method(PHASE_OPTIMIZE_FINISHED, 2);
2886 }
2887 
2888 //------------------------------Code_Gen---------------------------------------
2889 // Given a graph, generate code for it
2890 void Compile::Code_Gen() {
2891   if (failing()) {
2892     return;
2893   }
2894 
2895   // Perform instruction selection.  You might think we could reclaim Matcher
2896   // memory PDQ, but actually the Matcher is used in generating spill code.
2897   // Internals of the Matcher (including some VectorSets) must remain live
2898   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
2899   // set a bit in reclaimed memory.
2900 
2901   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2902   // nodes.  Mapping is only valid at the root of each matched subtree.
2903   NOT_PRODUCT( verify_graph_edges(); )
2904 
2905   Matcher matcher;
2906   _matcher = &matcher;
2907   {
2908     TracePhase tp("matcher", &timers[_t_matcher]);
2909     matcher.match();
2910   }
2911   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2912   // nodes.  Mapping is only valid at the root of each matched subtree.
2913   NOT_PRODUCT( verify_graph_edges(); )
2914 
2915   // If you have too many nodes, or if matching has failed, bail out
2916   check_node_count(0, "out of nodes matching instructions");
2917   if (failing()) {
2918     return;
2919   }
2920 
2921   print_method(PHASE_MATCHING, 2);
2922 
2923   // Build a proper-looking CFG
2924   PhaseCFG cfg(node_arena(), root(), matcher);
2925   _cfg = &cfg;
2926   {
2927     TracePhase tp("scheduler", &timers[_t_scheduler]);
2928     bool success = cfg.do_global_code_motion();
2929     if (!success) {
2930       return;
2931     }
2932 
2933     print_method(PHASE_GLOBAL_CODE_MOTION, 2);
2934     NOT_PRODUCT( verify_graph_edges(); )
2935     debug_only( cfg.verify(); )
2936   }
2937 
2938   PhaseChaitin regalloc(unique(), cfg, matcher, false);
2939   _regalloc = &regalloc;
2940   {
2941     TracePhase tp("regalloc", &timers[_t_registerAllocation]);
2942     // Perform register allocation.  After Chaitin, use-def chains are
2943     // no longer accurate (at spill code) and so must be ignored.
2944     // Node->LRG->reg mappings are still accurate.
2945     _regalloc->Register_Allocate();
2946 
2947     // Bail out if the allocator builds too many nodes
2948     if (failing()) {
2949       return;
2950     }
2951   }
2952 
2953   // Prior to register allocation we kept empty basic blocks in case the
2954   // the allocator needed a place to spill.  After register allocation we
2955   // are not adding any new instructions.  If any basic block is empty, we
2956   // can now safely remove it.
2957   {
2958     TracePhase tp("blockOrdering", &timers[_t_blockOrdering]);
2959     cfg.remove_empty_blocks();
2960     if (do_freq_based_layout()) {
2961       PhaseBlockLayout layout(cfg);
2962     } else {
2963       cfg.set_loop_alignment();
2964     }
2965     cfg.fixup_flow();
2966   }
2967 
2968   // Apply peephole optimizations
2969   if( OptoPeephole ) {
2970     TracePhase tp("peephole", &timers[_t_peephole]);
2971     PhasePeephole peep( _regalloc, cfg);
2972     peep.do_transform();
2973   }
2974 
2975   // Do late expand if CPU requires this.
2976   if (Matcher::require_postalloc_expand) {
2977     TracePhase tp("postalloc_expand", &timers[_t_postalloc_expand]);
2978     cfg.postalloc_expand(_regalloc);
2979   }
2980 
2981   // Convert Nodes to instruction bits in a buffer
2982   {
2983     TraceTime tp("output", &timers[_t_output], CITime);
2984     Output();
2985   }
2986 
2987   print_method(PHASE_FINAL_CODE);
2988 
2989   // He's dead, Jim.
2990   _cfg     = (PhaseCFG*)((intptr_t)0xdeadbeef);
2991   _regalloc = (PhaseChaitin*)((intptr_t)0xdeadbeef);
2992 }
2993 
2994 
2995 //------------------------------dump_asm---------------------------------------
2996 // Dump formatted assembly
2997 #if defined(SUPPORT_OPTO_ASSEMBLY)
2998 void Compile::dump_asm_on(outputStream* st, int* pcs, uint pc_limit) {
2999 
3000   int pc_digits = 3; // #chars required for pc
3001   int sb_chars  = 3; // #chars for "start bundle" indicator
3002   int tab_size  = 8;
3003   if (pcs != NULL) {
3004     int max_pc = 0;
3005     for (uint i = 0; i < pc_limit; i++) {
3006       max_pc = (max_pc < pcs[i]) ? pcs[i] : max_pc;
3007     }
3008     pc_digits  = ((max_pc < 4096) ? 3 : ((max_pc < 65536) ? 4 : ((max_pc < 65536*256) ? 6 : 8))); // #chars required for pc
3009   }
3010   int prefix_len = ((pc_digits + sb_chars + tab_size - 1)/tab_size)*tab_size;
3011 
3012   bool cut_short = false;
3013   st->print_cr("#");
3014   st->print("#  ");  _tf->dump_on(st);  st->cr();
3015   st->print_cr("#");
3016 
3017   // For all blocks
3018   int pc = 0x0;                 // Program counter
3019   char starts_bundle = ' ';
3020   _regalloc->dump_frame();
3021 
3022   Node *n = NULL;
3023   for (uint i = 0; i < _cfg->number_of_blocks(); i++) {
3024     if (VMThread::should_terminate()) {
3025       cut_short = true;
3026       break;
3027     }
3028     Block* block = _cfg->get_block(i);
3029     if (block->is_connector() && !Verbose) {
3030       continue;
3031     }
3032     n = block->head();
3033     if ((pcs != NULL) && (n->_idx < pc_limit)) {
3034       pc = pcs[n->_idx];
3035       st->print("%*.*x", pc_digits, pc_digits, pc);
3036     }
3037     st->fill_to(prefix_len);
3038     block->dump_head(_cfg, st);
3039     if (block->is_connector()) {
3040       st->fill_to(prefix_len);
3041       st->print_cr("# Empty connector block");
3042     } else if (block->num_preds() == 2 && block->pred(1)->is_CatchProj() && block->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
3043       st->fill_to(prefix_len);
3044       st->print_cr("# Block is sole successor of call");
3045     }
3046 
3047     // For all instructions
3048     Node *delay = NULL;
3049     for (uint j = 0; j < block->number_of_nodes(); j++) {
3050       if (VMThread::should_terminate()) {
3051         cut_short = true;
3052         break;
3053       }
3054       n = block->get_node(j);
3055       if (valid_bundle_info(n)) {
3056         Bundle* bundle = node_bundling(n);
3057         if (bundle->used_in_unconditional_delay()) {
3058           delay = n;
3059           continue;
3060         }
3061         if (bundle->starts_bundle()) {
3062           starts_bundle = '+';
3063         }
3064       }
3065 
3066       if (WizardMode) {
3067         n->dump();
3068       }
3069 
3070       if( !n->is_Region() &&    // Dont print in the Assembly
3071           !n->is_Phi() &&       // a few noisely useless nodes
3072           !n->is_Proj() &&
3073           !n->is_MachTemp() &&
3074           !n->is_SafePointScalarObject() &&
3075           !n->is_Catch() &&     // Would be nice to print exception table targets
3076           !n->is_MergeMem() &&  // Not very interesting
3077           !n->is_top() &&       // Debug info table constants
3078           !(n->is_Con() && !n->is_Mach())// Debug info table constants
3079           ) {
3080         if ((pcs != NULL) && (n->_idx < pc_limit)) {
3081           pc = pcs[n->_idx];
3082           st->print("%*.*x", pc_digits, pc_digits, pc);
3083         } else {
3084           st->fill_to(pc_digits);
3085         }
3086         st->print(" %c ", starts_bundle);
3087         starts_bundle = ' ';
3088         st->fill_to(prefix_len);
3089         n->format(_regalloc, st);
3090         st->cr();
3091       }
3092 
3093       // If we have an instruction with a delay slot, and have seen a delay,
3094       // then back up and print it
3095       if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
3096         // Coverity finding - Explicit null dereferenced.
3097         guarantee(delay != NULL, "no unconditional delay instruction");
3098         if (WizardMode) delay->dump();
3099 
3100         if (node_bundling(delay)->starts_bundle())
3101           starts_bundle = '+';
3102         if ((pcs != NULL) && (n->_idx < pc_limit)) {
3103           pc = pcs[n->_idx];
3104           st->print("%*.*x", pc_digits, pc_digits, pc);
3105         } else {
3106           st->fill_to(pc_digits);
3107         }
3108         st->print(" %c ", starts_bundle);
3109         starts_bundle = ' ';
3110         st->fill_to(prefix_len);
3111         delay->format(_regalloc, st);
3112         st->cr();
3113         delay = NULL;
3114       }
3115 
3116       // Dump the exception table as well
3117       if( n->is_Catch() && (Verbose || WizardMode) ) {
3118         // Print the exception table for this offset
3119         _handler_table.print_subtable_for(pc);
3120       }
3121       st->bol(); // Make sure we start on a new line
3122     }
3123     st->cr(); // one empty line between blocks
3124     assert(cut_short || delay == NULL, "no unconditional delay branch");
3125   } // End of per-block dump
3126 
3127   if (cut_short)  st->print_cr("*** disassembly is cut short ***");
3128 }
3129 #endif
3130 
3131 //------------------------------Final_Reshape_Counts---------------------------
3132 // This class defines counters to help identify when a method
3133 // may/must be executed using hardware with only 24-bit precision.
3134 struct Final_Reshape_Counts : public StackObj {
3135   int  _call_count;             // count non-inlined 'common' calls
3136   int  _float_count;            // count float ops requiring 24-bit precision
3137   int  _double_count;           // count double ops requiring more precision
3138   int  _java_call_count;        // count non-inlined 'java' calls
3139   int  _inner_loop_count;       // count loops which need alignment
3140   VectorSet _visited;           // Visitation flags
3141   Node_List _tests;             // Set of IfNodes & PCTableNodes
3142 
3143   Final_Reshape_Counts() :
3144     _call_count(0), _float_count(0), _double_count(0),
3145     _java_call_count(0), _inner_loop_count(0),
3146     _visited( Thread::current()->resource_area() ) { }
3147 
3148   void inc_call_count  () { _call_count  ++; }
3149   void inc_float_count () { _float_count ++; }
3150   void inc_double_count() { _double_count++; }
3151   void inc_java_call_count() { _java_call_count++; }
3152   void inc_inner_loop_count() { _inner_loop_count++; }
3153 
3154   int  get_call_count  () const { return _call_count  ; }
3155   int  get_float_count () const { return _float_count ; }
3156   int  get_double_count() const { return _double_count; }
3157   int  get_java_call_count() const { return _java_call_count; }
3158   int  get_inner_loop_count() const { return _inner_loop_count; }
3159 };
3160 
3161 #ifdef ASSERT
3162 static bool oop_offset_is_sane(const TypeInstPtr* tp) {
3163   ciInstanceKlass *k = tp->klass()->as_instance_klass();
3164   // Make sure the offset goes inside the instance layout.
3165   return k->contains_field_offset(tp->offset());
3166   // Note that OffsetBot and OffsetTop are very negative.
3167 }
3168 #endif
3169 
3170 // Eliminate trivially redundant StoreCMs and accumulate their
3171 // precedence edges.
3172 void Compile::eliminate_redundant_card_marks(Node* n) {
3173   assert(n->Opcode() == Op_StoreCM, "expected StoreCM");
3174   if (n->in(MemNode::Address)->outcnt() > 1) {
3175     // There are multiple users of the same address so it might be
3176     // possible to eliminate some of the StoreCMs
3177     Node* mem = n->in(MemNode::Memory);
3178     Node* adr = n->in(MemNode::Address);
3179     Node* val = n->in(MemNode::ValueIn);
3180     Node* prev = n;
3181     bool done = false;
3182     // Walk the chain of StoreCMs eliminating ones that match.  As
3183     // long as it's a chain of single users then the optimization is
3184     // safe.  Eliminating partially redundant StoreCMs would require
3185     // cloning copies down the other paths.
3186     while (mem->Opcode() == Op_StoreCM && mem->outcnt() == 1 && !done) {
3187       if (adr == mem->in(MemNode::Address) &&
3188           val == mem->in(MemNode::ValueIn)) {
3189         // redundant StoreCM
3190         if (mem->req() > MemNode::OopStore) {
3191           // Hasn't been processed by this code yet.
3192           n->add_prec(mem->in(MemNode::OopStore));
3193         } else {
3194           // Already converted to precedence edge
3195           for (uint i = mem->req(); i < mem->len(); i++) {
3196             // Accumulate any precedence edges
3197             if (mem->in(i) != NULL) {
3198               n->add_prec(mem->in(i));
3199             }
3200           }
3201           // Everything above this point has been processed.
3202           done = true;
3203         }
3204         // Eliminate the previous StoreCM
3205         prev->set_req(MemNode::Memory, mem->in(MemNode::Memory));
3206         assert(mem->outcnt() == 0, "should be dead");
3207         mem->disconnect_inputs(NULL, this);
3208       } else {
3209         prev = mem;
3210       }
3211       mem = prev->in(MemNode::Memory);
3212     }
3213   }
3214 }
3215 
3216 
3217 //------------------------------final_graph_reshaping_impl----------------------
3218 // Implement items 1-5 from final_graph_reshaping below.
3219 void Compile::final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &frc) {
3220 
3221   if ( n->outcnt() == 0 ) return; // dead node
3222   uint nop = n->Opcode();
3223 
3224   // Check for 2-input instruction with "last use" on right input.
3225   // Swap to left input.  Implements item (2).
3226   if( n->req() == 3 &&          // two-input instruction
3227       n->in(1)->outcnt() > 1 && // left use is NOT a last use
3228       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
3229       n->in(2)->outcnt() == 1 &&// right use IS a last use
3230       !n->in(2)->is_Con() ) {   // right use is not a constant
3231     // Check for commutative opcode
3232     switch( nop ) {
3233     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddL:
3234     case Op_MaxI:  case Op_MinI:
3235     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulL:
3236     case Op_AndL:  case Op_XorL:  case Op_OrL:
3237     case Op_AndI:  case Op_XorI:  case Op_OrI: {
3238       // Move "last use" input to left by swapping inputs
3239       n->swap_edges(1, 2);
3240       break;
3241     }
3242     default:
3243       break;
3244     }
3245   }
3246 
3247 #ifdef ASSERT
3248   if( n->is_Mem() ) {
3249     int alias_idx = get_alias_index(n->as_Mem()->adr_type());
3250     assert( n->in(0) != NULL || alias_idx != Compile::AliasIdxRaw ||
3251             // oop will be recorded in oop map if load crosses safepoint
3252             n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
3253                              LoadNode::is_immutable_value(n->in(MemNode::Address))),
3254             "raw memory operations should have control edge");
3255   }
3256   if (n->is_MemBar()) {
3257     MemBarNode* mb = n->as_MemBar();
3258     if (mb->trailing_store() || mb->trailing_load_store()) {
3259       assert(mb->leading_membar()->trailing_membar() == mb, "bad membar pair");
3260       Node* mem = BarrierSet::barrier_set()->barrier_set_c2()->step_over_gc_barrier(mb->in(MemBarNode::Precedent));
3261       assert((mb->trailing_store() && mem->is_Store() && mem->as_Store()->is_release()) ||
3262              (mb->trailing_load_store() && mem->is_LoadStore()), "missing mem op");
3263     } else if (mb->leading()) {
3264       assert(mb->trailing_membar()->leading_membar() == mb, "bad membar pair");
3265     }
3266   }
3267 #endif
3268   // Count FPU ops and common calls, implements item (3)
3269   bool gc_handled = BarrierSet::barrier_set()->barrier_set_c2()->final_graph_reshaping(this, n, nop);
3270   if (!gc_handled) {
3271     final_graph_reshaping_main_switch(n, frc, nop);
3272   }
3273 
3274   // Collect CFG split points
3275   if (n->is_MultiBranch() && !n->is_RangeCheck()) {
3276     frc._tests.push(n);
3277   }
3278 }
3279 
3280 void Compile::final_graph_reshaping_main_switch(Node* n, Final_Reshape_Counts& frc, uint nop) {
3281   switch( nop ) {
3282   // Count all float operations that may use FPU
3283   case Op_AddF:
3284   case Op_SubF:
3285   case Op_MulF:
3286   case Op_DivF:
3287   case Op_NegF:
3288   case Op_ModF:
3289   case Op_ConvI2F:
3290   case Op_ConF:
3291   case Op_CmpF:
3292   case Op_CmpF3:
3293   // case Op_ConvL2F: // longs are split into 32-bit halves
3294     frc.inc_float_count();
3295     break;
3296 
3297   case Op_ConvF2D:
3298   case Op_ConvD2F:
3299     frc.inc_float_count();
3300     frc.inc_double_count();
3301     break;
3302 
3303   // Count all double operations that may use FPU
3304   case Op_AddD:
3305   case Op_SubD:
3306   case Op_MulD:
3307   case Op_DivD:
3308   case Op_NegD:
3309   case Op_ModD:
3310   case Op_ConvI2D:
3311   case Op_ConvD2I:
3312   // case Op_ConvL2D: // handled by leaf call
3313   // case Op_ConvD2L: // handled by leaf call
3314   case Op_ConD:
3315   case Op_CmpD:
3316   case Op_CmpD3:
3317     frc.inc_double_count();
3318     break;
3319   case Op_Opaque1:              // Remove Opaque Nodes before matching
3320   case Op_Opaque2:              // Remove Opaque Nodes before matching
3321   case Op_Opaque3:
3322     n->subsume_by(n->in(1), this);
3323     break;
3324   case Op_CallStaticJava:
3325   case Op_CallJava:
3326   case Op_CallDynamicJava:
3327     frc.inc_java_call_count(); // Count java call site;
3328   case Op_CallRuntime:
3329   case Op_CallLeaf:
3330   case Op_CallLeafNoFP: {
3331     assert (n->is_Call(), "");
3332     CallNode *call = n->as_Call();
3333     // Count call sites where the FP mode bit would have to be flipped.
3334     // Do not count uncommon runtime calls:
3335     // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
3336     // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
3337     if (!call->is_CallStaticJava() || !call->as_CallStaticJava()->_name) {
3338       frc.inc_call_count();   // Count the call site
3339     } else {                  // See if uncommon argument is shared
3340       Node *n = call->in(TypeFunc::Parms);
3341       int nop = n->Opcode();
3342       // Clone shared simple arguments to uncommon calls, item (1).
3343       if (n->outcnt() > 1 &&
3344           !n->is_Proj() &&
3345           nop != Op_CreateEx &&
3346           nop != Op_CheckCastPP &&
3347           nop != Op_DecodeN &&
3348           nop != Op_DecodeNKlass &&
3349           !n->is_Mem() &&
3350           !n->is_Phi()) {
3351         Node *x = n->clone();
3352         call->set_req(TypeFunc::Parms, x);
3353       }
3354     }
3355     break;
3356   }
3357 
3358   case Op_StoreD:
3359   case Op_LoadD:
3360   case Op_LoadD_unaligned:
3361     frc.inc_double_count();
3362     goto handle_mem;
3363   case Op_StoreF:
3364   case Op_LoadF:
3365     frc.inc_float_count();
3366     goto handle_mem;
3367 
3368   case Op_StoreCM:
3369     {
3370       // Convert OopStore dependence into precedence edge
3371       Node* prec = n->in(MemNode::OopStore);
3372       n->del_req(MemNode::OopStore);
3373       n->add_prec(prec);
3374       eliminate_redundant_card_marks(n);
3375     }
3376 
3377     // fall through
3378 
3379   case Op_StoreB:
3380   case Op_StoreC:
3381   case Op_StorePConditional:
3382   case Op_StoreI:
3383   case Op_StoreL:
3384   case Op_StoreIConditional:
3385   case Op_StoreLConditional:
3386   case Op_CompareAndSwapB:
3387   case Op_CompareAndSwapS:
3388   case Op_CompareAndSwapI:
3389   case Op_CompareAndSwapL:
3390   case Op_CompareAndSwapP:
3391   case Op_CompareAndSwapN:
3392   case Op_WeakCompareAndSwapB:
3393   case Op_WeakCompareAndSwapS:
3394   case Op_WeakCompareAndSwapI:
3395   case Op_WeakCompareAndSwapL:
3396   case Op_WeakCompareAndSwapP:
3397   case Op_WeakCompareAndSwapN:
3398   case Op_CompareAndExchangeB:
3399   case Op_CompareAndExchangeS:
3400   case Op_CompareAndExchangeI:
3401   case Op_CompareAndExchangeL:
3402   case Op_CompareAndExchangeP:
3403   case Op_CompareAndExchangeN:
3404   case Op_GetAndAddS:
3405   case Op_GetAndAddB:
3406   case Op_GetAndAddI:
3407   case Op_GetAndAddL:
3408   case Op_GetAndSetS:
3409   case Op_GetAndSetB:
3410   case Op_GetAndSetI:
3411   case Op_GetAndSetL:
3412   case Op_GetAndSetP:
3413   case Op_GetAndSetN:
3414   case Op_StoreP:
3415   case Op_StoreN:
3416   case Op_StoreNKlass:
3417   case Op_LoadB:
3418   case Op_LoadUB:
3419   case Op_LoadUS:
3420   case Op_LoadI:
3421   case Op_LoadKlass:
3422   case Op_LoadNKlass:
3423   case Op_LoadL:
3424   case Op_LoadL_unaligned:
3425   case Op_LoadPLocked:
3426   case Op_LoadP:
3427   case Op_LoadN:
3428   case Op_LoadRange:
3429   case Op_LoadS: {
3430   handle_mem:
3431 #ifdef ASSERT
3432     if( VerifyOptoOopOffsets ) {
3433       MemNode* mem  = n->as_Mem();
3434       // Check to see if address types have grounded out somehow.
3435       const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
3436       assert( !tp || oop_offset_is_sane(tp), "" );
3437     }
3438 #endif
3439     if (EnableValhalla && (nop == Op_LoadKlass || nop == Op_LoadNKlass)) {
3440       const TypeKlassPtr* tk = n->bottom_type()->make_ptr()->is_klassptr();
3441       assert(!tk->klass_is_exact(), "should have been folded");
3442       ciKlass* klass = tk->klass();
3443       bool maybe_value_array = klass->is_java_lang_Object();
3444       if (!maybe_value_array && klass->is_obj_array_klass()) {
3445         klass = klass->as_array_klass()->element_klass();
3446         maybe_value_array = klass->is_java_lang_Object() || klass->is_interface() || klass->is_valuetype();
3447       }
3448       if (maybe_value_array) {
3449         // Array load klass needs to filter out property bits (but not
3450         // GetNullFreePropertyNode which needs to extract the null free bits)
3451         uint last = unique();
3452         Node* pointer = NULL;
3453         if (nop == Op_LoadKlass) {
3454           Node* cast = new CastP2XNode(NULL, n);
3455           Node* masked = new LShiftXNode(cast, new ConINode(TypeInt::make(oopDesc::storage_props_nof_bits)));
3456           masked = new RShiftXNode(masked, new ConINode(TypeInt::make(oopDesc::storage_props_nof_bits)));
3457           pointer = new CastX2PNode(masked);
3458           pointer = new CheckCastPPNode(NULL, pointer, n->bottom_type());
3459         } else {
3460           Node* cast = new CastN2INode(n);
3461           Node* masked = new AndINode(cast, new ConINode(TypeInt::make(oopDesc::compressed_klass_mask())));
3462           pointer = new CastI2NNode(masked, n->bottom_type());
3463         }
3464         for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3465           Node* u = n->fast_out(i);
3466           if (u->_idx < last && u->Opcode() != Op_GetNullFreeProperty) {
3467             int nb = u->replace_edge(n, pointer);
3468             --i, imax -= nb;
3469           }
3470         }
3471       }
3472     }
3473     break;
3474   }
3475 
3476   case Op_AddP: {               // Assert sane base pointers
3477     Node *addp = n->in(AddPNode::Address);
3478     assert( !addp->is_AddP() ||
3479             addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
3480             addp->in(AddPNode::Base) == n->in(AddPNode::Base),
3481             "Base pointers must match (addp %u)", addp->_idx );
3482 #ifdef _LP64
3483     if ((UseCompressedOops || UseCompressedClassPointers) &&
3484         addp->Opcode() == Op_ConP &&
3485         addp == n->in(AddPNode::Base) &&
3486         n->in(AddPNode::Offset)->is_Con()) {
3487       // If the transformation of ConP to ConN+DecodeN is beneficial depends
3488       // on the platform and on the compressed oops mode.
3489       // Use addressing with narrow klass to load with offset on x86.
3490       // Some platforms can use the constant pool to load ConP.
3491       // Do this transformation here since IGVN will convert ConN back to ConP.
3492       const Type* t = addp->bottom_type();
3493       bool is_oop   = t->isa_oopptr() != NULL;
3494       bool is_klass = t->isa_klassptr() != NULL;
3495 
3496       if ((is_oop   && Matcher::const_oop_prefer_decode()  ) ||
3497           (is_klass && Matcher::const_klass_prefer_decode())) {
3498         Node* nn = NULL;
3499 
3500         int op = is_oop ? Op_ConN : Op_ConNKlass;
3501 
3502         // Look for existing ConN node of the same exact type.
3503         Node* r  = root();
3504         uint cnt = r->outcnt();
3505         for (uint i = 0; i < cnt; i++) {
3506           Node* m = r->raw_out(i);
3507           if (m!= NULL && m->Opcode() == op &&
3508               m->bottom_type()->make_ptr() == t) {
3509             nn = m;
3510             break;
3511           }
3512         }
3513         if (nn != NULL) {
3514           // Decode a narrow oop to match address
3515           // [R12 + narrow_oop_reg<<3 + offset]
3516           if (is_oop) {
3517             nn = new DecodeNNode(nn, t);
3518           } else {
3519             nn = new DecodeNKlassNode(nn, t);
3520           }
3521           // Check for succeeding AddP which uses the same Base.
3522           // Otherwise we will run into the assertion above when visiting that guy.
3523           for (uint i = 0; i < n->outcnt(); ++i) {
3524             Node *out_i = n->raw_out(i);
3525             if (out_i && out_i->is_AddP() && out_i->in(AddPNode::Base) == addp) {
3526               out_i->set_req(AddPNode::Base, nn);
3527 #ifdef ASSERT
3528               for (uint j = 0; j < out_i->outcnt(); ++j) {
3529                 Node *out_j = out_i->raw_out(j);
3530                 assert(out_j == NULL || !out_j->is_AddP() || out_j->in(AddPNode::Base) != addp,
3531                        "more than 2 AddP nodes in a chain (out_j %u)", out_j->_idx);
3532               }
3533 #endif
3534             }
3535           }
3536           n->set_req(AddPNode::Base, nn);
3537           n->set_req(AddPNode::Address, nn);
3538           if (addp->outcnt() == 0) {
3539             addp->disconnect_inputs(NULL, this);
3540           }
3541         }
3542       }
3543     }
3544 #endif
3545     // platform dependent reshaping of the address expression
3546     reshape_address(n->as_AddP());
3547     break;
3548   }
3549 
3550   case Op_CastPP: {
3551     // Remove CastPP nodes to gain more freedom during scheduling but
3552     // keep the dependency they encode as control or precedence edges
3553     // (if control is set already) on memory operations. Some CastPP
3554     // nodes don't have a control (don't carry a dependency): skip
3555     // those.
3556     if (n->in(0) != NULL) {
3557       ResourceMark rm;
3558       Unique_Node_List wq;
3559       wq.push(n);
3560       for (uint next = 0; next < wq.size(); ++next) {
3561         Node *m = wq.at(next);
3562         for (DUIterator_Fast imax, i = m->fast_outs(imax); i < imax; i++) {
3563           Node* use = m->fast_out(i);
3564           if (use->is_Mem() || use->is_EncodeNarrowPtr()) {
3565             use->ensure_control_or_add_prec(n->in(0));
3566           } else {
3567             switch(use->Opcode()) {
3568             case Op_AddP:
3569             case Op_DecodeN:
3570             case Op_DecodeNKlass:
3571             case Op_CheckCastPP:
3572             case Op_CastPP:
3573               wq.push(use);
3574               break;
3575             }
3576           }
3577         }
3578       }
3579     }
3580     const bool is_LP64 = LP64_ONLY(true) NOT_LP64(false);
3581     if (is_LP64 && n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
3582       Node* in1 = n->in(1);
3583       const Type* t = n->bottom_type();
3584       Node* new_in1 = in1->clone();
3585       new_in1->as_DecodeN()->set_type(t);
3586 
3587       if (!Matcher::narrow_oop_use_complex_address()) {
3588         //
3589         // x86, ARM and friends can handle 2 adds in addressing mode
3590         // and Matcher can fold a DecodeN node into address by using
3591         // a narrow oop directly and do implicit NULL check in address:
3592         //
3593         // [R12 + narrow_oop_reg<<3 + offset]
3594         // NullCheck narrow_oop_reg
3595         //
3596         // On other platforms (Sparc) we have to keep new DecodeN node and
3597         // use it to do implicit NULL check in address:
3598         //
3599         // decode_not_null narrow_oop_reg, base_reg
3600         // [base_reg + offset]
3601         // NullCheck base_reg
3602         //
3603         // Pin the new DecodeN node to non-null path on these platform (Sparc)
3604         // to keep the information to which NULL check the new DecodeN node
3605         // corresponds to use it as value in implicit_null_check().
3606         //
3607         new_in1->set_req(0, n->in(0));
3608       }
3609 
3610       n->subsume_by(new_in1, this);
3611       if (in1->outcnt() == 0) {
3612         in1->disconnect_inputs(NULL, this);
3613       }
3614     } else {
3615       n->subsume_by(n->in(1), this);
3616       if (n->outcnt() == 0) {
3617         n->disconnect_inputs(NULL, this);
3618       }
3619     }
3620     break;
3621   }
3622 #ifdef _LP64
3623   case Op_CmpP:
3624     // Do this transformation here to preserve CmpPNode::sub() and
3625     // other TypePtr related Ideal optimizations (for example, ptr nullness).
3626     if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
3627       Node* in1 = n->in(1);
3628       Node* in2 = n->in(2);
3629       if (!in1->is_DecodeNarrowPtr()) {
3630         in2 = in1;
3631         in1 = n->in(2);
3632       }
3633       assert(in1->is_DecodeNarrowPtr(), "sanity");
3634 
3635       Node* new_in2 = NULL;
3636       if (in2->is_DecodeNarrowPtr()) {
3637         assert(in2->Opcode() == in1->Opcode(), "must be same node type");
3638         new_in2 = in2->in(1);
3639       } else if (in2->Opcode() == Op_ConP) {
3640         const Type* t = in2->bottom_type();
3641         if (t == TypePtr::NULL_PTR) {
3642           assert(in1->is_DecodeN(), "compare klass to null?");
3643           // Don't convert CmpP null check into CmpN if compressed
3644           // oops implicit null check is not generated.
3645           // This will allow to generate normal oop implicit null check.
3646           if (Matcher::gen_narrow_oop_implicit_null_checks())
3647             new_in2 = ConNode::make(TypeNarrowOop::NULL_PTR);
3648           //
3649           // This transformation together with CastPP transformation above
3650           // will generated code for implicit NULL checks for compressed oops.
3651           //
3652           // The original code after Optimize()
3653           //
3654           //    LoadN memory, narrow_oop_reg
3655           //    decode narrow_oop_reg, base_reg
3656           //    CmpP base_reg, NULL
3657           //    CastPP base_reg // NotNull
3658           //    Load [base_reg + offset], val_reg
3659           //
3660           // after these transformations will be
3661           //
3662           //    LoadN memory, narrow_oop_reg
3663           //    CmpN narrow_oop_reg, NULL
3664           //    decode_not_null narrow_oop_reg, base_reg
3665           //    Load [base_reg + offset], val_reg
3666           //
3667           // and the uncommon path (== NULL) will use narrow_oop_reg directly
3668           // since narrow oops can be used in debug info now (see the code in
3669           // final_graph_reshaping_walk()).
3670           //
3671           // At the end the code will be matched to
3672           // on x86:
3673           //
3674           //    Load_narrow_oop memory, narrow_oop_reg
3675           //    Load [R12 + narrow_oop_reg<<3 + offset], val_reg
3676           //    NullCheck narrow_oop_reg
3677           //
3678           // and on sparc:
3679           //
3680           //    Load_narrow_oop memory, narrow_oop_reg
3681           //    decode_not_null narrow_oop_reg, base_reg
3682           //    Load [base_reg + offset], val_reg
3683           //    NullCheck base_reg
3684           //
3685         } else if (t->isa_oopptr()) {
3686           new_in2 = ConNode::make(t->make_narrowoop());
3687         } else if (t->isa_klassptr()) {
3688           new_in2 = ConNode::make(t->make_narrowklass());
3689         }
3690       }
3691       if (new_in2 != NULL) {
3692         Node* cmpN = new CmpNNode(in1->in(1), new_in2);
3693         n->subsume_by(cmpN, this);
3694         if (in1->outcnt() == 0) {
3695           in1->disconnect_inputs(NULL, this);
3696         }
3697         if (in2->outcnt() == 0) {
3698           in2->disconnect_inputs(NULL, this);
3699         }
3700       }
3701     }
3702     break;
3703 
3704   case Op_DecodeN:
3705   case Op_DecodeNKlass:
3706     assert(!n->in(1)->is_EncodeNarrowPtr(), "should be optimized out");
3707     // DecodeN could be pinned when it can't be fold into
3708     // an address expression, see the code for Op_CastPP above.
3709     assert(n->in(0) == NULL || (UseCompressedOops && !Matcher::narrow_oop_use_complex_address()), "no control");
3710     break;
3711 
3712   case Op_EncodeP:
3713   case Op_EncodePKlass: {
3714     Node* in1 = n->in(1);
3715     if (in1->is_DecodeNarrowPtr()) {
3716       n->subsume_by(in1->in(1), this);
3717     } else if (in1->Opcode() == Op_ConP) {
3718       const Type* t = in1->bottom_type();
3719       if (t == TypePtr::NULL_PTR) {
3720         assert(t->isa_oopptr(), "null klass?");
3721         n->subsume_by(ConNode::make(TypeNarrowOop::NULL_PTR), this);
3722       } else if (t->isa_oopptr()) {
3723         n->subsume_by(ConNode::make(t->make_narrowoop()), this);
3724       } else if (t->isa_klassptr()) {
3725         n->subsume_by(ConNode::make(t->make_narrowklass()), this);
3726       }
3727     }
3728     if (in1->outcnt() == 0) {
3729       in1->disconnect_inputs(NULL, this);
3730     }
3731     break;
3732   }
3733 
3734   case Op_Proj: {
3735     if (OptimizeStringConcat) {
3736       ProjNode* p = n->as_Proj();
3737       if (p->_is_io_use) {
3738         // Separate projections were used for the exception path which
3739         // are normally removed by a late inline.  If it wasn't inlined
3740         // then they will hang around and should just be replaced with
3741         // the original one.
3742         Node* proj = NULL;
3743         // Replace with just one
3744         for (SimpleDUIterator i(p->in(0)); i.has_next(); i.next()) {
3745           Node *use = i.get();
3746           if (use->is_Proj() && p != use && use->as_Proj()->_con == p->_con) {
3747             proj = use;
3748             break;
3749           }
3750         }
3751         assert(proj != NULL || p->_con == TypeFunc::I_O, "io may be dropped at an infinite loop");
3752         if (proj != NULL) {
3753           p->subsume_by(proj, this);
3754         }
3755       }
3756     }
3757     break;
3758   }
3759 
3760   case Op_Phi:
3761     if (n->as_Phi()->bottom_type()->isa_narrowoop() || n->as_Phi()->bottom_type()->isa_narrowklass()) {
3762       // The EncodeP optimization may create Phi with the same edges
3763       // for all paths. It is not handled well by Register Allocator.
3764       Node* unique_in = n->in(1);
3765       assert(unique_in != NULL, "");
3766       uint cnt = n->req();
3767       for (uint i = 2; i < cnt; i++) {
3768         Node* m = n->in(i);
3769         assert(m != NULL, "");
3770         if (unique_in != m)
3771           unique_in = NULL;
3772       }
3773       if (unique_in != NULL) {
3774         n->subsume_by(unique_in, this);
3775       }
3776     }
3777     break;
3778 
3779 #endif
3780 
3781 #ifdef ASSERT
3782   case Op_CastII:
3783     // Verify that all range check dependent CastII nodes were removed.
3784     if (n->isa_CastII()->has_range_check()) {
3785       n->dump(3);
3786       assert(false, "Range check dependent CastII node was not removed");
3787     }
3788     break;
3789 #endif
3790 
3791   case Op_ModI:
3792     if (UseDivMod) {
3793       // Check if a%b and a/b both exist
3794       Node* d = n->find_similar(Op_DivI);
3795       if (d) {
3796         // Replace them with a fused divmod if supported
3797         if (Matcher::has_match_rule(Op_DivModI)) {
3798           DivModINode* divmod = DivModINode::make(n);
3799           d->subsume_by(divmod->div_proj(), this);
3800           n->subsume_by(divmod->mod_proj(), this);
3801         } else {
3802           // replace a%b with a-((a/b)*b)
3803           Node* mult = new MulINode(d, d->in(2));
3804           Node* sub  = new SubINode(d->in(1), mult);
3805           n->subsume_by(sub, this);
3806         }
3807       }
3808     }
3809     break;
3810 
3811   case Op_ModL:
3812     if (UseDivMod) {
3813       // Check if a%b and a/b both exist
3814       Node* d = n->find_similar(Op_DivL);
3815       if (d) {
3816         // Replace them with a fused divmod if supported
3817         if (Matcher::has_match_rule(Op_DivModL)) {
3818           DivModLNode* divmod = DivModLNode::make(n);
3819           d->subsume_by(divmod->div_proj(), this);
3820           n->subsume_by(divmod->mod_proj(), this);
3821         } else {
3822           // replace a%b with a-((a/b)*b)
3823           Node* mult = new MulLNode(d, d->in(2));
3824           Node* sub  = new SubLNode(d->in(1), mult);
3825           n->subsume_by(sub, this);
3826         }
3827       }
3828     }
3829     break;
3830 
3831   case Op_LoadVector:
3832   case Op_StoreVector:
3833     break;
3834 
3835   case Op_AddReductionVI:
3836   case Op_AddReductionVL:
3837   case Op_AddReductionVF:
3838   case Op_AddReductionVD:
3839   case Op_MulReductionVI:
3840   case Op_MulReductionVL:
3841   case Op_MulReductionVF:
3842   case Op_MulReductionVD:
3843   case Op_MinReductionV:
3844   case Op_MaxReductionV:
3845     break;
3846 
3847   case Op_PackB:
3848   case Op_PackS:
3849   case Op_PackI:
3850   case Op_PackF:
3851   case Op_PackL:
3852   case Op_PackD:
3853     if (n->req()-1 > 2) {
3854       // Replace many operand PackNodes with a binary tree for matching
3855       PackNode* p = (PackNode*) n;
3856       Node* btp = p->binary_tree_pack(1, n->req());
3857       n->subsume_by(btp, this);
3858     }
3859     break;
3860   case Op_Loop:
3861   case Op_CountedLoop:
3862   case Op_OuterStripMinedLoop:
3863     if (n->as_Loop()->is_inner_loop()) {
3864       frc.inc_inner_loop_count();
3865     }
3866     n->as_Loop()->verify_strip_mined(0);
3867     break;
3868   case Op_LShiftI:
3869   case Op_RShiftI:
3870   case Op_URShiftI:
3871   case Op_LShiftL:
3872   case Op_RShiftL:
3873   case Op_URShiftL:
3874     if (Matcher::need_masked_shift_count) {
3875       // The cpu's shift instructions don't restrict the count to the
3876       // lower 5/6 bits. We need to do the masking ourselves.
3877       Node* in2 = n->in(2);
3878       juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
3879       const TypeInt* t = in2->find_int_type();
3880       if (t != NULL && t->is_con()) {
3881         juint shift = t->get_con();
3882         if (shift > mask) { // Unsigned cmp
3883           n->set_req(2, ConNode::make(TypeInt::make(shift & mask)));
3884         }
3885       } else {
3886         if (t == NULL || t->_lo < 0 || t->_hi > (int)mask) {
3887           Node* shift = new AndINode(in2, ConNode::make(TypeInt::make(mask)));
3888           n->set_req(2, shift);
3889         }
3890       }
3891       if (in2->outcnt() == 0) { // Remove dead node
3892         in2->disconnect_inputs(NULL, this);
3893       }
3894     }
3895     break;
3896   case Op_MemBarStoreStore:
3897   case Op_MemBarRelease:
3898     // Break the link with AllocateNode: it is no longer useful and
3899     // confuses register allocation.
3900     if (n->req() > MemBarNode::Precedent) {
3901       n->set_req(MemBarNode::Precedent, top());
3902     }
3903     break;
3904   case Op_MemBarAcquire: {
3905     if (n->as_MemBar()->trailing_load() && n->req() > MemBarNode::Precedent) {
3906       // At parse time, the trailing MemBarAcquire for a volatile load
3907       // is created with an edge to the load. After optimizations,
3908       // that input may be a chain of Phis. If those phis have no
3909       // other use, then the MemBarAcquire keeps them alive and
3910       // register allocation can be confused.
3911       ResourceMark rm;
3912       Unique_Node_List wq;
3913       wq.push(n->in(MemBarNode::Precedent));
3914       n->set_req(MemBarNode::Precedent, top());
3915       while (wq.size() > 0) {
3916         Node* m = wq.pop();
3917         if (m->outcnt() == 0) {
3918           for (uint j = 0; j < m->req(); j++) {
3919             Node* in = m->in(j);
3920             if (in != NULL) {
3921               wq.push(in);
3922             }
3923           }
3924           m->disconnect_inputs(NULL, this);
3925         }
3926       }
3927     }
3928     break;
3929   }
3930   case Op_RangeCheck: {
3931     RangeCheckNode* rc = n->as_RangeCheck();
3932     Node* iff = new IfNode(rc->in(0), rc->in(1), rc->_prob, rc->_fcnt);
3933     n->subsume_by(iff, this);
3934     frc._tests.push(iff);
3935     break;
3936   }
3937   case Op_ConvI2L: {
3938     if (!Matcher::convi2l_type_required) {
3939       // Code generation on some platforms doesn't need accurate
3940       // ConvI2L types. Widening the type can help remove redundant
3941       // address computations.
3942       n->as_Type()->set_type(TypeLong::INT);
3943       ResourceMark rm;
3944       Node_List wq;
3945       wq.push(n);
3946       for (uint next = 0; next < wq.size(); next++) {
3947         Node *m = wq.at(next);
3948 
3949         for(;;) {
3950           // Loop over all nodes with identical inputs edges as m
3951           Node* k = m->find_similar(m->Opcode());
3952           if (k == NULL) {
3953             break;
3954           }
3955           // Push their uses so we get a chance to remove node made
3956           // redundant
3957           for (DUIterator_Fast imax, i = k->fast_outs(imax); i < imax; i++) {
3958             Node* u = k->fast_out(i);
3959             assert(!wq.contains(u), "shouldn't process one node several times");
3960             if (u->Opcode() == Op_LShiftL ||
3961                 u->Opcode() == Op_AddL ||
3962                 u->Opcode() == Op_SubL ||
3963                 u->Opcode() == Op_AddP) {
3964               wq.push(u);
3965             }
3966           }
3967           // Replace all nodes with identical edges as m with m
3968           k->subsume_by(m, this);
3969         }
3970       }
3971     }
3972     break;
3973   }
3974   case Op_CmpUL: {
3975     if (!Matcher::has_match_rule(Op_CmpUL)) {
3976       // No support for unsigned long comparisons
3977       ConINode* sign_pos = new ConINode(TypeInt::make(BitsPerLong - 1));
3978       Node* sign_bit_mask = new RShiftLNode(n->in(1), sign_pos);
3979       Node* orl = new OrLNode(n->in(1), sign_bit_mask);
3980       ConLNode* remove_sign_mask = new ConLNode(TypeLong::make(max_jlong));
3981       Node* andl = new AndLNode(orl, remove_sign_mask);
3982       Node* cmp = new CmpLNode(andl, n->in(2));
3983       n->subsume_by(cmp, this);
3984     }
3985     break;
3986   }
3987 #ifdef ASSERT
3988   case Op_ValueTypePtr:
3989   case Op_ValueType: {
3990     n->dump(-1);
3991     assert(false, "value type node was not removed");
3992     break;
3993   }
3994 #endif
3995   case Op_GetNullFreeProperty: {
3996     // Extract the null free bits
3997     uint last = unique();
3998     Node* null_free = NULL;
3999     if (n->in(1)->Opcode() == Op_LoadKlass) {
4000       Node* cast = new CastP2XNode(NULL, n->in(1));
4001       null_free = new AndLNode(cast, new ConLNode(TypeLong::make(((jlong)1)<<(oopDesc::wide_storage_props_shift + ArrayStorageProperties::null_free_bit))));
4002     } else {
4003       assert(n->in(1)->Opcode() == Op_LoadNKlass, "not a compressed klass?");
4004       Node* cast = new CastN2INode(n->in(1));
4005       null_free = new AndINode(cast, new ConINode(TypeInt::make(1<<(oopDesc::narrow_storage_props_shift + ArrayStorageProperties::null_free_bit))));
4006     }
4007     n->replace_by(null_free);
4008     break;
4009   }
4010   default:
4011     assert(!n->is_Call(), "");
4012     assert(!n->is_Mem(), "");
4013     assert(nop != Op_ProfileBoolean, "should be eliminated during IGVN");
4014     break;
4015   }
4016 }
4017 
4018 //------------------------------final_graph_reshaping_walk---------------------
4019 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
4020 // requires that the walk visits a node's inputs before visiting the node.
4021 void Compile::final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Reshape_Counts &frc ) {
4022   ResourceArea *area = Thread::current()->resource_area();
4023   Unique_Node_List sfpt(area);
4024 
4025   frc._visited.set(root->_idx); // first, mark node as visited
4026   uint cnt = root->req();
4027   Node *n = root;
4028   uint  i = 0;
4029   while (true) {
4030     if (i < cnt) {
4031       // Place all non-visited non-null inputs onto stack
4032       Node* m = n->in(i);
4033       ++i;
4034       if (m != NULL && !frc._visited.test_set(m->_idx)) {
4035         if (m->is_SafePoint() && m->as_SafePoint()->jvms() != NULL) {
4036           // compute worst case interpreter size in case of a deoptimization
4037           update_interpreter_frame_size(m->as_SafePoint()->jvms()->interpreter_frame_size());
4038 
4039           sfpt.push(m);
4040         }
4041         cnt = m->req();
4042         nstack.push(n, i); // put on stack parent and next input's index
4043         n = m;
4044         i = 0;
4045       }
4046     } else {
4047       // Now do post-visit work
4048       final_graph_reshaping_impl( n, frc );
4049       if (nstack.is_empty())
4050         break;             // finished
4051       n = nstack.node();   // Get node from stack
4052       cnt = n->req();
4053       i = nstack.index();
4054       nstack.pop();        // Shift to the next node on stack
4055     }
4056   }
4057 
4058   // Skip next transformation if compressed oops are not used.
4059   if ((UseCompressedOops && !Matcher::gen_narrow_oop_implicit_null_checks()) ||
4060       (!UseCompressedOops && !UseCompressedClassPointers))
4061     return;
4062 
4063   // Go over safepoints nodes to skip DecodeN/DecodeNKlass nodes for debug edges.
4064   // It could be done for an uncommon traps or any safepoints/calls
4065   // if the DecodeN/DecodeNKlass node is referenced only in a debug info.
4066   while (sfpt.size() > 0) {
4067     n = sfpt.pop();
4068     JVMState *jvms = n->as_SafePoint()->jvms();
4069     assert(jvms != NULL, "sanity");
4070     int start = jvms->debug_start();
4071     int end   = n->req();
4072     bool is_uncommon = (n->is_CallStaticJava() &&
4073                         n->as_CallStaticJava()->uncommon_trap_request() != 0);
4074     for (int j = start; j < end; j++) {
4075       Node* in = n->in(j);
4076       if (in->is_DecodeNarrowPtr()) {
4077         bool safe_to_skip = true;
4078         if (!is_uncommon ) {
4079           // Is it safe to skip?
4080           for (uint i = 0; i < in->outcnt(); i++) {
4081             Node* u = in->raw_out(i);
4082             if (!u->is_SafePoint() ||
4083                 (u->is_Call() && u->as_Call()->has_non_debug_use(n))) {
4084               safe_to_skip = false;
4085             }
4086           }
4087         }
4088         if (safe_to_skip) {
4089           n->set_req(j, in->in(1));
4090         }
4091         if (in->outcnt() == 0) {
4092           in->disconnect_inputs(NULL, this);
4093         }
4094       }
4095     }
4096   }
4097 }
4098 
4099 //------------------------------final_graph_reshaping--------------------------
4100 // Final Graph Reshaping.
4101 //
4102 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
4103 //     and not commoned up and forced early.  Must come after regular
4104 //     optimizations to avoid GVN undoing the cloning.  Clone constant
4105 //     inputs to Loop Phis; these will be split by the allocator anyways.
4106 //     Remove Opaque nodes.
4107 // (2) Move last-uses by commutative operations to the left input to encourage
4108 //     Intel update-in-place two-address operations and better register usage
4109 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
4110 //     calls canonicalizing them back.
4111 // (3) Count the number of double-precision FP ops, single-precision FP ops
4112 //     and call sites.  On Intel, we can get correct rounding either by
4113 //     forcing singles to memory (requires extra stores and loads after each
4114 //     FP bytecode) or we can set a rounding mode bit (requires setting and
4115 //     clearing the mode bit around call sites).  The mode bit is only used
4116 //     if the relative frequency of single FP ops to calls is low enough.
4117 //     This is a key transform for SPEC mpeg_audio.
4118 // (4) Detect infinite loops; blobs of code reachable from above but not
4119 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
4120 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
4121 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
4122 //     Detection is by looking for IfNodes where only 1 projection is
4123 //     reachable from below or CatchNodes missing some targets.
4124 // (5) Assert for insane oop offsets in debug mode.
4125 
4126 bool Compile::final_graph_reshaping() {
4127   // an infinite loop may have been eliminated by the optimizer,
4128   // in which case the graph will be empty.
4129   if (root()->req() == 1) {
4130     record_method_not_compilable("trivial infinite loop");
4131     return true;
4132   }
4133 
4134   // Expensive nodes have their control input set to prevent the GVN
4135   // from freely commoning them. There's no GVN beyond this point so
4136   // no need to keep the control input. We want the expensive nodes to
4137   // be freely moved to the least frequent code path by gcm.
4138   assert(OptimizeExpensiveOps || expensive_count() == 0, "optimization off but list non empty?");
4139   for (int i = 0; i < expensive_count(); i++) {
4140     _expensive_nodes->at(i)->set_req(0, NULL);
4141   }
4142 
4143   Final_Reshape_Counts frc;
4144 
4145   // Visit everybody reachable!
4146   // Allocate stack of size C->live_nodes()/2 to avoid frequent realloc
4147   Node_Stack nstack(live_nodes() >> 1);
4148   final_graph_reshaping_walk(nstack, root(), frc);
4149 
4150   // Check for unreachable (from below) code (i.e., infinite loops).
4151   for( uint i = 0; i < frc._tests.size(); i++ ) {
4152     MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
4153     // Get number of CFG targets.
4154     // Note that PCTables include exception targets after calls.
4155     uint required_outcnt = n->required_outcnt();
4156     if (n->outcnt() != required_outcnt) {
4157       // Check for a few special cases.  Rethrow Nodes never take the
4158       // 'fall-thru' path, so expected kids is 1 less.
4159       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
4160         if (n->in(0)->in(0)->is_Call()) {
4161           CallNode *call = n->in(0)->in(0)->as_Call();
4162           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
4163             required_outcnt--;      // Rethrow always has 1 less kid
4164           } else if (call->req() > TypeFunc::Parms &&
4165                      call->is_CallDynamicJava()) {
4166             // Check for null receiver. In such case, the optimizer has
4167             // detected that the virtual call will always result in a null
4168             // pointer exception. The fall-through projection of this CatchNode
4169             // will not be populated.
4170             Node *arg0 = call->in(TypeFunc::Parms);
4171             if (arg0->is_Type() &&
4172                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
4173               required_outcnt--;
4174             }
4175           } else if (call->entry_point() == OptoRuntime::new_array_Java() &&
4176                      call->req() > TypeFunc::Parms+1 &&
4177                      call->is_CallStaticJava()) {
4178             // Check for negative array length. In such case, the optimizer has
4179             // detected that the allocation attempt will always result in an
4180             // exception. There is no fall-through projection of this CatchNode .
4181             Node *arg1 = call->in(TypeFunc::Parms+1);
4182             if (arg1->is_Type() &&
4183                 arg1->as_Type()->type()->join(TypeInt::POS)->empty()) {
4184               required_outcnt--;
4185             }
4186           }
4187         }
4188       }
4189       // Recheck with a better notion of 'required_outcnt'
4190       if (n->outcnt() != required_outcnt) {
4191         record_method_not_compilable("malformed control flow");
4192         return true;            // Not all targets reachable!
4193       }
4194     }
4195     // Check that I actually visited all kids.  Unreached kids
4196     // must be infinite loops.
4197     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
4198       if (!frc._visited.test(n->fast_out(j)->_idx)) {
4199         record_method_not_compilable("infinite loop");
4200         return true;            // Found unvisited kid; must be unreach
4201       }
4202 
4203     // Here so verification code in final_graph_reshaping_walk()
4204     // always see an OuterStripMinedLoopEnd
4205     if (n->is_OuterStripMinedLoopEnd()) {
4206       IfNode* init_iff = n->as_If();
4207       Node* iff = new IfNode(init_iff->in(0), init_iff->in(1), init_iff->_prob, init_iff->_fcnt);
4208       n->subsume_by(iff, this);
4209     }
4210   }
4211 
4212   // If original bytecodes contained a mixture of floats and doubles
4213   // check if the optimizer has made it homogenous, item (3).
4214   if( Use24BitFPMode && Use24BitFP && UseSSE == 0 &&
4215       frc.get_float_count() > 32 &&
4216       frc.get_double_count() == 0 &&
4217       (10 * frc.get_call_count() < frc.get_float_count()) ) {
4218     set_24_bit_selection_and_mode( false,  true );
4219   }
4220 
4221   set_java_calls(frc.get_java_call_count());
4222   set_inner_loops(frc.get_inner_loop_count());
4223 
4224   // No infinite loops, no reason to bail out.
4225   return false;
4226 }
4227 
4228 //-----------------------------too_many_traps----------------------------------
4229 // Report if there are too many traps at the current method and bci.
4230 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
4231 bool Compile::too_many_traps(ciMethod* method,
4232                              int bci,
4233                              Deoptimization::DeoptReason reason) {
4234   ciMethodData* md = method->method_data();
4235   if (md->is_empty()) {
4236     // Assume the trap has not occurred, or that it occurred only
4237     // because of a transient condition during start-up in the interpreter.
4238     return false;
4239   }
4240   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
4241   if (md->has_trap_at(bci, m, reason) != 0) {
4242     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
4243     // Also, if there are multiple reasons, or if there is no per-BCI record,
4244     // assume the worst.
4245     if (log())
4246       log()->elem("observe trap='%s' count='%d'",
4247                   Deoptimization::trap_reason_name(reason),
4248                   md->trap_count(reason));
4249     return true;
4250   } else {
4251     // Ignore method/bci and see if there have been too many globally.
4252     return too_many_traps(reason, md);
4253   }
4254 }
4255 
4256 // Less-accurate variant which does not require a method and bci.
4257 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
4258                              ciMethodData* logmd) {
4259   if (trap_count(reason) >= Deoptimization::per_method_trap_limit(reason)) {
4260     // Too many traps globally.
4261     // Note that we use cumulative trap_count, not just md->trap_count.
4262     if (log()) {
4263       int mcount = (logmd == NULL)? -1: (int)logmd->trap_count(reason);
4264       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
4265                   Deoptimization::trap_reason_name(reason),
4266                   mcount, trap_count(reason));
4267     }
4268     return true;
4269   } else {
4270     // The coast is clear.
4271     return false;
4272   }
4273 }
4274 
4275 //--------------------------too_many_recompiles--------------------------------
4276 // Report if there are too many recompiles at the current method and bci.
4277 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
4278 // Is not eager to return true, since this will cause the compiler to use
4279 // Action_none for a trap point, to avoid too many recompilations.
4280 bool Compile::too_many_recompiles(ciMethod* method,
4281                                   int bci,
4282                                   Deoptimization::DeoptReason reason) {
4283   ciMethodData* md = method->method_data();
4284   if (md->is_empty()) {
4285     // Assume the trap has not occurred, or that it occurred only
4286     // because of a transient condition during start-up in the interpreter.
4287     return false;
4288   }
4289   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
4290   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
4291   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
4292   Deoptimization::DeoptReason per_bc_reason
4293     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
4294   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
4295   if ((per_bc_reason == Deoptimization::Reason_none
4296        || md->has_trap_at(bci, m, reason) != 0)
4297       // The trap frequency measure we care about is the recompile count:
4298       && md->trap_recompiled_at(bci, m)
4299       && md->overflow_recompile_count() >= bc_cutoff) {
4300     // Do not emit a trap here if it has already caused recompilations.
4301     // Also, if there are multiple reasons, or if there is no per-BCI record,
4302     // assume the worst.
4303     if (log())
4304       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
4305                   Deoptimization::trap_reason_name(reason),
4306                   md->trap_count(reason),
4307                   md->overflow_recompile_count());
4308     return true;
4309   } else if (trap_count(reason) != 0
4310              && decompile_count() >= m_cutoff) {
4311     // Too many recompiles globally, and we have seen this sort of trap.
4312     // Use cumulative decompile_count, not just md->decompile_count.
4313     if (log())
4314       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
4315                   Deoptimization::trap_reason_name(reason),
4316                   md->trap_count(reason), trap_count(reason),
4317                   md->decompile_count(), decompile_count());
4318     return true;
4319   } else {
4320     // The coast is clear.
4321     return false;
4322   }
4323 }
4324 
4325 // Compute when not to trap. Used by matching trap based nodes and
4326 // NullCheck optimization.
4327 void Compile::set_allowed_deopt_reasons() {
4328   _allowed_reasons = 0;
4329   if (is_method_compilation()) {
4330     for (int rs = (int)Deoptimization::Reason_none+1; rs < Compile::trapHistLength; rs++) {
4331       assert(rs < BitsPerInt, "recode bit map");
4332       if (!too_many_traps((Deoptimization::DeoptReason) rs)) {
4333         _allowed_reasons |= nth_bit(rs);
4334       }
4335     }
4336   }
4337 }
4338 
4339 bool Compile::needs_clinit_barrier(ciMethod* method, ciMethod* accessing_method) {
4340   return method->is_static() && needs_clinit_barrier(method->holder(), accessing_method);
4341 }
4342 
4343 bool Compile::needs_clinit_barrier(ciField* field, ciMethod* accessing_method) {
4344   return field->is_static() && needs_clinit_barrier(field->holder(), accessing_method);
4345 }
4346 
4347 bool Compile::needs_clinit_barrier(ciInstanceKlass* holder, ciMethod* accessing_method) {
4348   if (holder->is_initialized()) {
4349     return false;
4350   }
4351   if (holder->is_being_initialized()) {
4352     if (accessing_method->holder() == holder) {
4353       // Access inside a class. The barrier can be elided when access happens in <clinit>,
4354       // <init>, or a static method. In all those cases, there was an initialization
4355       // barrier on the holder klass passed.
4356       if (accessing_method->is_class_initializer() ||
4357           accessing_method->is_object_constructor() ||
4358           accessing_method->is_static()) {
4359         return false;
4360       }
4361     } else if (accessing_method->holder()->is_subclass_of(holder)) {
4362       // Access from a subclass. The barrier can be elided only when access happens in <clinit>.
4363       // In case of <init> or a static method, the barrier is on the subclass is not enough:
4364       // child class can become fully initialized while its parent class is still being initialized.
4365       if (accessing_method->is_class_initializer()) {
4366         return false;
4367       }
4368     }
4369     ciMethod* root = method(); // the root method of compilation
4370     if (root != accessing_method) {
4371       return needs_clinit_barrier(holder, root); // check access in the context of compilation root
4372     }
4373   }
4374   return true;
4375 }
4376 
4377 #ifndef PRODUCT
4378 //------------------------------verify_graph_edges---------------------------
4379 // Walk the Graph and verify that there is a one-to-one correspondence
4380 // between Use-Def edges and Def-Use edges in the graph.
4381 void Compile::verify_graph_edges(bool no_dead_code) {
4382   if (VerifyGraphEdges) {
4383     ResourceArea *area = Thread::current()->resource_area();
4384     Unique_Node_List visited(area);
4385     // Call recursive graph walk to check edges
4386     _root->verify_edges(visited);
4387     if (no_dead_code) {
4388       // Now make sure that no visited node is used by an unvisited node.
4389       bool dead_nodes = false;
4390       Unique_Node_List checked(area);
4391       while (visited.size() > 0) {
4392         Node* n = visited.pop();
4393         checked.push(n);
4394         for (uint i = 0; i < n->outcnt(); i++) {
4395           Node* use = n->raw_out(i);
4396           if (checked.member(use))  continue;  // already checked
4397           if (visited.member(use))  continue;  // already in the graph
4398           if (use->is_Con())        continue;  // a dead ConNode is OK
4399           // At this point, we have found a dead node which is DU-reachable.
4400           if (!dead_nodes) {
4401             tty->print_cr("*** Dead nodes reachable via DU edges:");
4402             dead_nodes = true;
4403           }
4404           use->dump(2);
4405           tty->print_cr("---");
4406           checked.push(use);  // No repeats; pretend it is now checked.
4407         }
4408       }
4409       assert(!dead_nodes, "using nodes must be reachable from root");
4410     }
4411   }
4412 }
4413 #endif
4414 
4415 // The Compile object keeps track of failure reasons separately from the ciEnv.
4416 // This is required because there is not quite a 1-1 relation between the
4417 // ciEnv and its compilation task and the Compile object.  Note that one
4418 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
4419 // to backtrack and retry without subsuming loads.  Other than this backtracking
4420 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
4421 // by the logic in C2Compiler.
4422 void Compile::record_failure(const char* reason) {
4423   if (log() != NULL) {
4424     log()->elem("failure reason='%s' phase='compile'", reason);
4425   }
4426   if (_failure_reason == NULL) {
4427     // Record the first failure reason.
4428     _failure_reason = reason;
4429   }
4430 
4431   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
4432     C->print_method(PHASE_FAILURE);
4433   }
4434   _root = NULL;  // flush the graph, too
4435 }
4436 
4437 Compile::TracePhase::TracePhase(const char* name, elapsedTimer* accumulator)
4438   : TraceTime(name, accumulator, CITime, CITimeVerbose),
4439     _phase_name(name), _dolog(CITimeVerbose)
4440 {
4441   if (_dolog) {
4442     C = Compile::current();
4443     _log = C->log();
4444   } else {
4445     C = NULL;
4446     _log = NULL;
4447   }
4448   if (_log != NULL) {
4449     _log->begin_head("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
4450     _log->stamp();
4451     _log->end_head();
4452   }
4453 }
4454 
4455 Compile::TracePhase::~TracePhase() {
4456 
4457   C = Compile::current();
4458   if (_dolog) {
4459     _log = C->log();
4460   } else {
4461     _log = NULL;
4462   }
4463 
4464 #ifdef ASSERT
4465   if (PrintIdealNodeCount) {
4466     tty->print_cr("phase name='%s' nodes='%d' live='%d' live_graph_walk='%d'",
4467                   _phase_name, C->unique(), C->live_nodes(), C->count_live_nodes_by_graph_walk());
4468   }
4469 
4470   if (VerifyIdealNodeCount) {
4471     Compile::current()->print_missing_nodes();
4472   }
4473 #endif
4474 
4475   if (_log != NULL) {
4476     _log->done("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
4477   }
4478 }
4479 
4480 //=============================================================================
4481 // Two Constant's are equal when the type and the value are equal.
4482 bool Compile::Constant::operator==(const Constant& other) {
4483   if (type()          != other.type()         )  return false;
4484   if (can_be_reused() != other.can_be_reused())  return false;
4485   // For floating point values we compare the bit pattern.
4486   switch (type()) {
4487   case T_INT:
4488   case T_FLOAT:   return (_v._value.i == other._v._value.i);
4489   case T_LONG:
4490   case T_DOUBLE:  return (_v._value.j == other._v._value.j);
4491   case T_OBJECT:
4492   case T_ADDRESS: return (_v._value.l == other._v._value.l);
4493   case T_VOID:    return (_v._value.l == other._v._value.l);  // jump-table entries
4494   case T_METADATA: return (_v._metadata == other._v._metadata);
4495   default: ShouldNotReachHere(); return false;
4496   }
4497 }
4498 
4499 static int type_to_size_in_bytes(BasicType t) {
4500   switch (t) {
4501   case T_INT:     return sizeof(jint   );
4502   case T_LONG:    return sizeof(jlong  );
4503   case T_FLOAT:   return sizeof(jfloat );
4504   case T_DOUBLE:  return sizeof(jdouble);
4505   case T_METADATA: return sizeof(Metadata*);
4506     // We use T_VOID as marker for jump-table entries (labels) which
4507     // need an internal word relocation.
4508   case T_VOID:
4509   case T_ADDRESS:
4510   case T_OBJECT:  return sizeof(jobject);
4511   default:
4512     ShouldNotReachHere();
4513     return -1;
4514   }
4515 }
4516 
4517 int Compile::ConstantTable::qsort_comparator(Constant* a, Constant* b) {
4518   // sort descending
4519   if (a->freq() > b->freq())  return -1;
4520   if (a->freq() < b->freq())  return  1;
4521   return 0;
4522 }
4523 
4524 void Compile::ConstantTable::calculate_offsets_and_size() {
4525   // First, sort the array by frequencies.
4526   _constants.sort(qsort_comparator);
4527 
4528 #ifdef ASSERT
4529   // Make sure all jump-table entries were sorted to the end of the
4530   // array (they have a negative frequency).
4531   bool found_void = false;
4532   for (int i = 0; i < _constants.length(); i++) {
4533     Constant con = _constants.at(i);
4534     if (con.type() == T_VOID)
4535       found_void = true;  // jump-tables
4536     else
4537       assert(!found_void, "wrong sorting");
4538   }
4539 #endif
4540 
4541   int offset = 0;
4542   for (int i = 0; i < _constants.length(); i++) {
4543     Constant* con = _constants.adr_at(i);
4544 
4545     // Align offset for type.
4546     int typesize = type_to_size_in_bytes(con->type());
4547     offset = align_up(offset, typesize);
4548     con->set_offset(offset);   // set constant's offset
4549 
4550     if (con->type() == T_VOID) {
4551       MachConstantNode* n = (MachConstantNode*) con->get_jobject();
4552       offset = offset + typesize * n->outcnt();  // expand jump-table
4553     } else {
4554       offset = offset + typesize;
4555     }
4556   }
4557 
4558   // Align size up to the next section start (which is insts; see
4559   // CodeBuffer::align_at_start).
4560   assert(_size == -1, "already set?");
4561   _size = align_up(offset, (int)CodeEntryAlignment);
4562 }
4563 
4564 void Compile::ConstantTable::emit(CodeBuffer& cb) {
4565   MacroAssembler _masm(&cb);
4566   for (int i = 0; i < _constants.length(); i++) {
4567     Constant con = _constants.at(i);
4568     address constant_addr = NULL;
4569     switch (con.type()) {
4570     case T_INT:    constant_addr = _masm.int_constant(   con.get_jint()   ); break;
4571     case T_LONG:   constant_addr = _masm.long_constant(  con.get_jlong()  ); break;
4572     case T_FLOAT:  constant_addr = _masm.float_constant( con.get_jfloat() ); break;
4573     case T_DOUBLE: constant_addr = _masm.double_constant(con.get_jdouble()); break;
4574     case T_OBJECT: {
4575       jobject obj = con.get_jobject();
4576       int oop_index = _masm.oop_recorder()->find_index(obj);
4577       constant_addr = _masm.address_constant((address) obj, oop_Relocation::spec(oop_index));
4578       break;
4579     }
4580     case T_ADDRESS: {
4581       address addr = (address) con.get_jobject();
4582       constant_addr = _masm.address_constant(addr);
4583       break;
4584     }
4585     // We use T_VOID as marker for jump-table entries (labels) which
4586     // need an internal word relocation.
4587     case T_VOID: {
4588       MachConstantNode* n = (MachConstantNode*) con.get_jobject();
4589       // Fill the jump-table with a dummy word.  The real value is
4590       // filled in later in fill_jump_table.
4591       address dummy = (address) n;
4592       constant_addr = _masm.address_constant(dummy);
4593       // Expand jump-table
4594       for (uint i = 1; i < n->outcnt(); i++) {
4595         address temp_addr = _masm.address_constant(dummy + i);
4596         assert(temp_addr, "consts section too small");
4597       }
4598       break;
4599     }
4600     case T_METADATA: {
4601       Metadata* obj = con.get_metadata();
4602       int metadata_index = _masm.oop_recorder()->find_index(obj);
4603       constant_addr = _masm.address_constant((address) obj, metadata_Relocation::spec(metadata_index));
4604       break;
4605     }
4606     default: ShouldNotReachHere();
4607     }
4608     assert(constant_addr, "consts section too small");
4609     assert((constant_addr - _masm.code()->consts()->start()) == con.offset(),
4610             "must be: %d == %d", (int) (constant_addr - _masm.code()->consts()->start()), (int)(con.offset()));
4611   }
4612 }
4613 
4614 int Compile::ConstantTable::find_offset(Constant& con) const {
4615   int idx = _constants.find(con);
4616   guarantee(idx != -1, "constant must be in constant table");
4617   int offset = _constants.at(idx).offset();
4618   guarantee(offset != -1, "constant table not emitted yet?");
4619   return offset;
4620 }
4621 
4622 void Compile::ConstantTable::add(Constant& con) {
4623   if (con.can_be_reused()) {
4624     int idx = _constants.find(con);
4625     if (idx != -1 && _constants.at(idx).can_be_reused()) {
4626       _constants.adr_at(idx)->inc_freq(con.freq());  // increase the frequency by the current value
4627       return;
4628     }
4629   }
4630   (void) _constants.append(con);
4631 }
4632 
4633 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, BasicType type, jvalue value) {
4634   Block* b = Compile::current()->cfg()->get_block_for_node(n);
4635   Constant con(type, value, b->_freq);
4636   add(con);
4637   return con;
4638 }
4639 
4640 Compile::Constant Compile::ConstantTable::add(Metadata* metadata) {
4641   Constant con(metadata);
4642   add(con);
4643   return con;
4644 }
4645 
4646 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, MachOper* oper) {
4647   jvalue value;
4648   BasicType type = oper->type()->basic_type();
4649   switch (type) {
4650   case T_LONG:    value.j = oper->constantL(); break;
4651   case T_FLOAT:   value.f = oper->constantF(); break;
4652   case T_DOUBLE:  value.d = oper->constantD(); break;
4653   case T_OBJECT:
4654   case T_ADDRESS: value.l = (jobject) oper->constant(); break;
4655   case T_METADATA: return add((Metadata*)oper->constant()); break;
4656   default: guarantee(false, "unhandled type: %s", type2name(type));
4657   }
4658   return add(n, type, value);
4659 }
4660 
4661 Compile::Constant Compile::ConstantTable::add_jump_table(MachConstantNode* n) {
4662   jvalue value;
4663   // We can use the node pointer here to identify the right jump-table
4664   // as this method is called from Compile::Fill_buffer right before
4665   // the MachNodes are emitted and the jump-table is filled (means the
4666   // MachNode pointers do not change anymore).
4667   value.l = (jobject) n;
4668   Constant con(T_VOID, value, next_jump_table_freq(), false);  // Labels of a jump-table cannot be reused.
4669   add(con);
4670   return con;
4671 }
4672 
4673 void Compile::ConstantTable::fill_jump_table(CodeBuffer& cb, MachConstantNode* n, GrowableArray<Label*> labels) const {
4674   // If called from Compile::scratch_emit_size do nothing.
4675   if (Compile::current()->in_scratch_emit_size())  return;
4676 
4677   assert(labels.is_nonempty(), "must be");
4678   assert((uint) labels.length() == n->outcnt(), "must be equal: %d == %d", labels.length(), n->outcnt());
4679 
4680   // Since MachConstantNode::constant_offset() also contains
4681   // table_base_offset() we need to subtract the table_base_offset()
4682   // to get the plain offset into the constant table.
4683   int offset = n->constant_offset() - table_base_offset();
4684 
4685   MacroAssembler _masm(&cb);
4686   address* jump_table_base = (address*) (_masm.code()->consts()->start() + offset);
4687 
4688   for (uint i = 0; i < n->outcnt(); i++) {
4689     address* constant_addr = &jump_table_base[i];
4690     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));
4691     *constant_addr = cb.consts()->target(*labels.at(i), (address) constant_addr);
4692     cb.consts()->relocate((address) constant_addr, relocInfo::internal_word_type);
4693   }
4694 }
4695 
4696 //----------------------------static_subtype_check-----------------------------
4697 // Shortcut important common cases when superklass is exact:
4698 // (0) superklass is java.lang.Object (can occur in reflective code)
4699 // (1) subklass is already limited to a subtype of superklass => always ok
4700 // (2) subklass does not overlap with superklass => always fail
4701 // (3) superklass has NO subtypes and we can check with a simple compare.
4702 int Compile::static_subtype_check(ciKlass* superk, ciKlass* subk) {
4703   if (StressReflectiveCode || superk == NULL || subk == NULL) {
4704     return SSC_full_test;       // Let caller generate the general case.
4705   }
4706 
4707   if (superk == env()->Object_klass()) {
4708     return SSC_always_true;     // (0) this test cannot fail
4709   }
4710 
4711   ciType* superelem = superk;
4712   if (superelem->is_array_klass()) {
4713     ciArrayKlass* ak = superelem->as_array_klass();
4714     superelem = superelem->as_array_klass()->base_element_type();
4715   }
4716 
4717   if (!subk->is_interface()) {  // cannot trust static interface types yet
4718     if (subk->is_subtype_of(superk)) {
4719       return SSC_always_true;   // (1) false path dead; no dynamic test needed
4720     }
4721     if (!(superelem->is_klass() && superelem->as_klass()->is_interface()) &&
4722         !superk->is_subtype_of(subk)) {
4723       return SSC_always_false;
4724     }
4725   }
4726 
4727   // Do not fold the subtype check to an array klass pointer comparison for [V? arrays.
4728   // [V is a subtype of [V? but the klass for [V is not equal to the klass for [V?. Perform a full test.
4729   if (superk->is_obj_array_klass() && !superk->as_array_klass()->storage_properties().is_null_free() && superk->as_array_klass()->element_klass()->is_valuetype()) {
4730     return SSC_full_test;
4731   }
4732   // If casting to an instance klass, it must have no subtypes
4733   if (superk->is_interface()) {
4734     // Cannot trust interfaces yet.
4735     // %%% S.B. superk->nof_implementors() == 1
4736   } else if (superelem->is_instance_klass()) {
4737     ciInstanceKlass* ik = superelem->as_instance_klass();
4738     if (!ik->has_subklass() && !ik->is_interface()) {
4739       if (!ik->is_final()) {
4740         // Add a dependency if there is a chance of a later subclass.
4741         dependencies()->assert_leaf_type(ik);
4742       }
4743       return SSC_easy_test;     // (3) caller can do a simple ptr comparison
4744     }
4745   } else {
4746     // A primitive array type has no subtypes.
4747     return SSC_easy_test;       // (3) caller can do a simple ptr comparison
4748   }
4749 
4750   return SSC_full_test;
4751 }
4752 
4753 Node* Compile::conv_I2X_index(PhaseGVN* phase, Node* idx, const TypeInt* sizetype, Node* ctrl) {
4754 #ifdef _LP64
4755   // The scaled index operand to AddP must be a clean 64-bit value.
4756   // Java allows a 32-bit int to be incremented to a negative
4757   // value, which appears in a 64-bit register as a large
4758   // positive number.  Using that large positive number as an
4759   // operand in pointer arithmetic has bad consequences.
4760   // On the other hand, 32-bit overflow is rare, and the possibility
4761   // can often be excluded, if we annotate the ConvI2L node with
4762   // a type assertion that its value is known to be a small positive
4763   // number.  (The prior range check has ensured this.)
4764   // This assertion is used by ConvI2LNode::Ideal.
4765   int index_max = max_jint - 1;  // array size is max_jint, index is one less
4766   if (sizetype != NULL) index_max = sizetype->_hi - 1;
4767   const TypeInt* iidxtype = TypeInt::make(0, index_max, Type::WidenMax);
4768   idx = constrained_convI2L(phase, idx, iidxtype, ctrl);
4769 #endif
4770   return idx;
4771 }
4772 
4773 // Convert integer value to a narrowed long type dependent on ctrl (for example, a range check)
4774 Node* Compile::constrained_convI2L(PhaseGVN* phase, Node* value, const TypeInt* itype, Node* ctrl) {
4775   if (ctrl != NULL) {
4776     // Express control dependency by a CastII node with a narrow type.
4777     value = new CastIINode(value, itype, false, true /* range check dependency */);
4778     // Make the CastII node dependent on the control input to prevent the narrowed ConvI2L
4779     // node from floating above the range check during loop optimizations. Otherwise, the
4780     // ConvI2L node may be eliminated independently of the range check, causing the data path
4781     // to become TOP while the control path is still there (although it's unreachable).
4782     value->set_req(0, ctrl);
4783     // Save CastII node to remove it after loop optimizations.
4784     phase->C->add_range_check_cast(value);
4785     value = phase->transform(value);
4786   }
4787   const TypeLong* ltype = TypeLong::make(itype->_lo, itype->_hi, itype->_widen);
4788   return phase->transform(new ConvI2LNode(value, ltype));
4789 }
4790 
4791 // The message about the current inlining is accumulated in
4792 // _print_inlining_stream and transfered into the _print_inlining_list
4793 // once we know whether inlining succeeds or not. For regular
4794 // inlining, messages are appended to the buffer pointed by
4795 // _print_inlining_idx in the _print_inlining_list. For late inlining,
4796 // a new buffer is added after _print_inlining_idx in the list. This
4797 // way we can update the inlining message for late inlining call site
4798 // when the inlining is attempted again.
4799 void Compile::print_inlining_init() {
4800   if (print_inlining() || print_intrinsics()) {
4801     _print_inlining_stream = new stringStream();
4802     _print_inlining_list = new (comp_arena())GrowableArray<PrintInliningBuffer>(comp_arena(), 1, 1, PrintInliningBuffer());
4803   }
4804 }
4805 
4806 void Compile::print_inlining_reinit() {
4807   if (print_inlining() || print_intrinsics()) {
4808     // Re allocate buffer when we change ResourceMark
4809     _print_inlining_stream = new stringStream();
4810   }
4811 }
4812 
4813 void Compile::print_inlining_reset() {
4814   _print_inlining_stream->reset();
4815 }
4816 
4817 void Compile::print_inlining_commit() {
4818   assert(print_inlining() || print_intrinsics(), "PrintInlining off?");
4819   // Transfer the message from _print_inlining_stream to the current
4820   // _print_inlining_list buffer and clear _print_inlining_stream.
4821   _print_inlining_list->at(_print_inlining_idx).ss()->write(_print_inlining_stream->as_string(), _print_inlining_stream->size());
4822   print_inlining_reset();
4823 }
4824 
4825 void Compile::print_inlining_push() {
4826   // Add new buffer to the _print_inlining_list at current position
4827   _print_inlining_idx++;
4828   _print_inlining_list->insert_before(_print_inlining_idx, PrintInliningBuffer());
4829 }
4830 
4831 Compile::PrintInliningBuffer& Compile::print_inlining_current() {
4832   return _print_inlining_list->at(_print_inlining_idx);
4833 }
4834 
4835 void Compile::print_inlining_update(CallGenerator* cg) {
4836   if (print_inlining() || print_intrinsics()) {
4837     if (!cg->is_late_inline()) {
4838       if (print_inlining_current().cg() != NULL) {
4839         print_inlining_push();
4840       }
4841       print_inlining_commit();
4842     } else {
4843       if (print_inlining_current().cg() != cg &&
4844           (print_inlining_current().cg() != NULL ||
4845            print_inlining_current().ss()->size() != 0)) {
4846         print_inlining_push();
4847       }
4848       print_inlining_commit();
4849       print_inlining_current().set_cg(cg);
4850     }
4851   }
4852 }
4853 
4854 void Compile::print_inlining_move_to(CallGenerator* cg) {
4855   // We resume inlining at a late inlining call site. Locate the
4856   // corresponding inlining buffer so that we can update it.
4857   if (print_inlining()) {
4858     for (int i = 0; i < _print_inlining_list->length(); i++) {
4859       if (_print_inlining_list->adr_at(i)->cg() == cg) {
4860         _print_inlining_idx = i;
4861         return;
4862       }
4863     }
4864     ShouldNotReachHere();
4865   }
4866 }
4867 
4868 void Compile::print_inlining_update_delayed(CallGenerator* cg) {
4869   if (print_inlining()) {
4870     assert(_print_inlining_stream->size() > 0, "missing inlining msg");
4871     assert(print_inlining_current().cg() == cg, "wrong entry");
4872     // replace message with new message
4873     _print_inlining_list->at_put(_print_inlining_idx, PrintInliningBuffer());
4874     print_inlining_commit();
4875     print_inlining_current().set_cg(cg);
4876   }
4877 }
4878 
4879 void Compile::print_inlining_assert_ready() {
4880   assert(!_print_inlining || _print_inlining_stream->size() == 0, "loosing data");
4881 }
4882 
4883 void Compile::process_print_inlining() {
4884   bool do_print_inlining = print_inlining() || print_intrinsics();
4885   if (do_print_inlining || log() != NULL) {
4886     // Print inlining message for candidates that we couldn't inline
4887     // for lack of space
4888     for (int i = 0; i < _late_inlines.length(); i++) {
4889       CallGenerator* cg = _late_inlines.at(i);
4890       if (!cg->is_mh_late_inline()) {
4891         const char* msg = "live nodes > LiveNodeCountInliningCutoff";
4892         if (do_print_inlining) {
4893           cg->print_inlining_late(msg);
4894         }
4895         log_late_inline_failure(cg, msg);
4896       }
4897     }
4898   }
4899   if (do_print_inlining) {
4900     ResourceMark rm;
4901     stringStream ss;
4902     for (int i = 0; i < _print_inlining_list->length(); i++) {
4903       ss.print("%s", _print_inlining_list->adr_at(i)->ss()->as_string());
4904     }
4905     size_t end = ss.size();
4906     _print_inlining_output = NEW_ARENA_ARRAY(comp_arena(), char, end+1);
4907     strncpy(_print_inlining_output, ss.base(), end+1);
4908     _print_inlining_output[end] = 0;
4909   }
4910 }
4911 
4912 void Compile::dump_print_inlining() {
4913   if (_print_inlining_output != NULL) {
4914     tty->print_raw(_print_inlining_output);
4915   }
4916 }
4917 
4918 void Compile::log_late_inline(CallGenerator* cg) {
4919   if (log() != NULL) {
4920     log()->head("late_inline method='%d'  inline_id='" JLONG_FORMAT "'", log()->identify(cg->method()),
4921                 cg->unique_id());
4922     JVMState* p = cg->call_node()->jvms();
4923     while (p != NULL) {
4924       log()->elem("jvms bci='%d' method='%d'", p->bci(), log()->identify(p->method()));
4925       p = p->caller();
4926     }
4927     log()->tail("late_inline");
4928   }
4929 }
4930 
4931 void Compile::log_late_inline_failure(CallGenerator* cg, const char* msg) {
4932   log_late_inline(cg);
4933   if (log() != NULL) {
4934     log()->inline_fail(msg);
4935   }
4936 }
4937 
4938 void Compile::log_inline_id(CallGenerator* cg) {
4939   if (log() != NULL) {
4940     // The LogCompilation tool needs a unique way to identify late
4941     // inline call sites. This id must be unique for this call site in
4942     // this compilation. Try to have it unique across compilations as
4943     // well because it can be convenient when grepping through the log
4944     // file.
4945     // Distinguish OSR compilations from others in case CICountOSR is
4946     // on.
4947     jlong id = ((jlong)unique()) + (((jlong)compile_id()) << 33) + (CICountOSR && is_osr_compilation() ? ((jlong)1) << 32 : 0);
4948     cg->set_unique_id(id);
4949     log()->elem("inline_id id='" JLONG_FORMAT "'", id);
4950   }
4951 }
4952 
4953 void Compile::log_inline_failure(const char* msg) {
4954   if (C->log() != NULL) {
4955     C->log()->inline_fail(msg);
4956   }
4957 }
4958 
4959 
4960 // Dump inlining replay data to the stream.
4961 // Don't change thread state and acquire any locks.
4962 void Compile::dump_inline_data(outputStream* out) {
4963   InlineTree* inl_tree = ilt();
4964   if (inl_tree != NULL) {
4965     out->print(" inline %d", inl_tree->count());
4966     inl_tree->dump_replay_data(out);
4967   }
4968 }
4969 
4970 int Compile::cmp_expensive_nodes(Node* n1, Node* n2) {
4971   if (n1->Opcode() < n2->Opcode())      return -1;
4972   else if (n1->Opcode() > n2->Opcode()) return 1;
4973 
4974   assert(n1->req() == n2->req(), "can't compare %s nodes: n1->req() = %d, n2->req() = %d", NodeClassNames[n1->Opcode()], n1->req(), n2->req());
4975   for (uint i = 1; i < n1->req(); i++) {
4976     if (n1->in(i) < n2->in(i))      return -1;
4977     else if (n1->in(i) > n2->in(i)) return 1;
4978   }
4979 
4980   return 0;
4981 }
4982 
4983 int Compile::cmp_expensive_nodes(Node** n1p, Node** n2p) {
4984   Node* n1 = *n1p;
4985   Node* n2 = *n2p;
4986 
4987   return cmp_expensive_nodes(n1, n2);
4988 }
4989 
4990 void Compile::sort_expensive_nodes() {
4991   if (!expensive_nodes_sorted()) {
4992     _expensive_nodes->sort(cmp_expensive_nodes);
4993   }
4994 }
4995 
4996 bool Compile::expensive_nodes_sorted() const {
4997   for (int i = 1; i < _expensive_nodes->length(); i++) {
4998     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i-1)) < 0) {
4999       return false;
5000     }
5001   }
5002   return true;
5003 }
5004 
5005 bool Compile::should_optimize_expensive_nodes(PhaseIterGVN &igvn) {
5006   if (_expensive_nodes->length() == 0) {
5007     return false;
5008   }
5009 
5010   assert(OptimizeExpensiveOps, "optimization off?");
5011 
5012   // Take this opportunity to remove dead nodes from the list
5013   int j = 0;
5014   for (int i = 0; i < _expensive_nodes->length(); i++) {
5015     Node* n = _expensive_nodes->at(i);
5016     if (!n->is_unreachable(igvn)) {
5017       assert(n->is_expensive(), "should be expensive");
5018       _expensive_nodes->at_put(j, n);
5019       j++;
5020     }
5021   }
5022   _expensive_nodes->trunc_to(j);
5023 
5024   // Then sort the list so that similar nodes are next to each other
5025   // and check for at least two nodes of identical kind with same data
5026   // inputs.
5027   sort_expensive_nodes();
5028 
5029   for (int i = 0; i < _expensive_nodes->length()-1; i++) {
5030     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i+1)) == 0) {
5031       return true;
5032     }
5033   }
5034 
5035   return false;
5036 }
5037 
5038 void Compile::cleanup_expensive_nodes(PhaseIterGVN &igvn) {
5039   if (_expensive_nodes->length() == 0) {
5040     return;
5041   }
5042 
5043   assert(OptimizeExpensiveOps, "optimization off?");
5044 
5045   // Sort to bring similar nodes next to each other and clear the
5046   // control input of nodes for which there's only a single copy.
5047   sort_expensive_nodes();
5048 
5049   int j = 0;
5050   int identical = 0;
5051   int i = 0;
5052   bool modified = false;
5053   for (; i < _expensive_nodes->length()-1; i++) {
5054     assert(j <= i, "can't write beyond current index");
5055     if (_expensive_nodes->at(i)->Opcode() == _expensive_nodes->at(i+1)->Opcode()) {
5056       identical++;
5057       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
5058       continue;
5059     }
5060     if (identical > 0) {
5061       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
5062       identical = 0;
5063     } else {
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   }
5070   if (identical > 0) {
5071     _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
5072   } else if (_expensive_nodes->length() >= 1) {
5073     Node* n = _expensive_nodes->at(i);
5074     igvn.replace_input_of(n, 0, NULL);
5075     igvn.hash_insert(n);
5076     modified = true;
5077   }
5078   _expensive_nodes->trunc_to(j);
5079   if (modified) {
5080     igvn.optimize();
5081   }
5082 }
5083 
5084 void Compile::add_expensive_node(Node * n) {
5085   assert(!_expensive_nodes->contains(n), "duplicate entry in expensive list");
5086   assert(n->is_expensive(), "expensive nodes with non-null control here only");
5087   assert(!n->is_CFG() && !n->is_Mem(), "no cfg or memory nodes here");
5088   if (OptimizeExpensiveOps) {
5089     _expensive_nodes->append(n);
5090   } else {
5091     // Clear control input and let IGVN optimize expensive nodes if
5092     // OptimizeExpensiveOps is off.
5093     n->set_req(0, NULL);
5094   }
5095 }
5096 
5097 /**
5098  * Remove the speculative part of types and clean up the graph
5099  */
5100 void Compile::remove_speculative_types(PhaseIterGVN &igvn) {
5101   if (UseTypeSpeculation) {
5102     Unique_Node_List worklist;
5103     worklist.push(root());
5104     int modified = 0;
5105     // Go over all type nodes that carry a speculative type, drop the
5106     // speculative part of the type and enqueue the node for an igvn
5107     // which may optimize it out.
5108     for (uint next = 0; next < worklist.size(); ++next) {
5109       Node *n  = worklist.at(next);
5110       if (n->is_Type()) {
5111         TypeNode* tn = n->as_Type();
5112         const Type* t = tn->type();
5113         const Type* t_no_spec = t->remove_speculative();
5114         if (t_no_spec != t) {
5115           bool in_hash = igvn.hash_delete(n);
5116           assert(in_hash, "node should be in igvn hash table");
5117           tn->set_type(t_no_spec);
5118           igvn.hash_insert(n);
5119           igvn._worklist.push(n); // give it a chance to go away
5120           modified++;
5121         }
5122       }
5123       uint max = n->len();
5124       for( uint i = 0; i < max; ++i ) {
5125         Node *m = n->in(i);
5126         if (not_a_node(m))  continue;
5127         worklist.push(m);
5128       }
5129     }
5130     // Drop the speculative part of all types in the igvn's type table
5131     igvn.remove_speculative_types();
5132     if (modified > 0) {
5133       igvn.optimize();
5134     }
5135 #ifdef ASSERT
5136     // Verify that after the IGVN is over no speculative type has resurfaced
5137     worklist.clear();
5138     worklist.push(root());
5139     for (uint next = 0; next < worklist.size(); ++next) {
5140       Node *n  = worklist.at(next);
5141       const Type* t = igvn.type_or_null(n);
5142       assert((t == NULL) || (t == t->remove_speculative()), "no more speculative types");
5143       if (n->is_Type()) {
5144         t = n->as_Type()->type();
5145         assert(t == t->remove_speculative(), "no more speculative types");
5146       }
5147       uint max = n->len();
5148       for( uint i = 0; i < max; ++i ) {
5149         Node *m = n->in(i);
5150         if (not_a_node(m))  continue;
5151         worklist.push(m);
5152       }
5153     }
5154     igvn.check_no_speculative_types();
5155 #endif
5156   }
5157 }
5158 
5159 Node* Compile::optimize_acmp(PhaseGVN* phase, Node* a, Node* b) {
5160   const TypeInstPtr* ta = phase->type(a)->isa_instptr();
5161   const TypeInstPtr* tb = phase->type(b)->isa_instptr();
5162   if (!EnableValhalla || ta == NULL || tb == NULL ||
5163       ta->is_zero_type() || tb->is_zero_type() ||
5164       !ta->can_be_value_type() || !tb->can_be_value_type()) {
5165     // Use old acmp if one operand is null or not a value type
5166     return new CmpPNode(a, b);
5167   } else if (ta->is_valuetypeptr() || tb->is_valuetypeptr()) {
5168     // We know that one operand is a value type. Therefore,
5169     // new acmp will only return true if both operands are NULL.
5170     // Check if both operands are null by or'ing the oops.
5171     a = phase->transform(new CastP2XNode(NULL, a));
5172     b = phase->transform(new CastP2XNode(NULL, b));
5173     a = phase->transform(new OrXNode(a, b));
5174     return new CmpXNode(a, phase->MakeConX(0));
5175   }
5176   // Use new acmp
5177   return NULL;
5178 }
5179 
5180 // Auxiliary method to support randomized stressing/fuzzing.
5181 //
5182 // This method can be called the arbitrary number of times, with current count
5183 // as the argument. The logic allows selecting a single candidate from the
5184 // running list of candidates as follows:
5185 //    int count = 0;
5186 //    Cand* selected = null;
5187 //    while(cand = cand->next()) {
5188 //      if (randomized_select(++count)) {
5189 //        selected = cand;
5190 //      }
5191 //    }
5192 //
5193 // Including count equalizes the chances any candidate is "selected".
5194 // This is useful when we don't have the complete list of candidates to choose
5195 // from uniformly. In this case, we need to adjust the randomicity of the
5196 // selection, or else we will end up biasing the selection towards the latter
5197 // candidates.
5198 //
5199 // Quick back-envelope calculation shows that for the list of n candidates
5200 // the equal probability for the candidate to persist as "best" can be
5201 // achieved by replacing it with "next" k-th candidate with the probability
5202 // of 1/k. It can be easily shown that by the end of the run, the
5203 // probability for any candidate is converged to 1/n, thus giving the
5204 // uniform distribution among all the candidates.
5205 //
5206 // We don't care about the domain size as long as (RANDOMIZED_DOMAIN / count) is large.
5207 #define RANDOMIZED_DOMAIN_POW 29
5208 #define RANDOMIZED_DOMAIN (1 << RANDOMIZED_DOMAIN_POW)
5209 #define RANDOMIZED_DOMAIN_MASK ((1 << (RANDOMIZED_DOMAIN_POW + 1)) - 1)
5210 bool Compile::randomized_select(int count) {
5211   assert(count > 0, "only positive");
5212   return (os::random() & RANDOMIZED_DOMAIN_MASK) < (RANDOMIZED_DOMAIN / count);
5213 }
5214 
5215 CloneMap&     Compile::clone_map()                 { return _clone_map; }
5216 void          Compile::set_clone_map(Dict* d)      { _clone_map._dict = d; }
5217 
5218 void NodeCloneInfo::dump() const {
5219   tty->print(" {%d:%d} ", idx(), gen());
5220 }
5221 
5222 void CloneMap::clone(Node* old, Node* nnn, int gen) {
5223   uint64_t val = value(old->_idx);
5224   NodeCloneInfo cio(val);
5225   assert(val != 0, "old node should be in the map");
5226   NodeCloneInfo cin(cio.idx(), gen + cio.gen());
5227   insert(nnn->_idx, cin.get());
5228 #ifndef PRODUCT
5229   if (is_debug()) {
5230     tty->print_cr("CloneMap::clone inserted node %d info {%d:%d} into CloneMap", nnn->_idx, cin.idx(), cin.gen());
5231   }
5232 #endif
5233 }
5234 
5235 void CloneMap::verify_insert_and_clone(Node* old, Node* nnn, int gen) {
5236   NodeCloneInfo cio(value(old->_idx));
5237   if (cio.get() == 0) {
5238     cio.set(old->_idx, 0);
5239     insert(old->_idx, cio.get());
5240 #ifndef PRODUCT
5241     if (is_debug()) {
5242       tty->print_cr("CloneMap::verify_insert_and_clone inserted node %d info {%d:%d} into CloneMap", old->_idx, cio.idx(), cio.gen());
5243     }
5244 #endif
5245   }
5246   clone(old, nnn, gen);
5247 }
5248 
5249 int CloneMap::max_gen() const {
5250   int g = 0;
5251   DictI di(_dict);
5252   for(; di.test(); ++di) {
5253     int t = gen(di._key);
5254     if (g < t) {
5255       g = t;
5256 #ifndef PRODUCT
5257       if (is_debug()) {
5258         tty->print_cr("CloneMap::max_gen() update max=%d from %d", g, _2_node_idx_t(di._key));
5259       }
5260 #endif
5261     }
5262   }
5263   return g;
5264 }
5265 
5266 void CloneMap::dump(node_idx_t key) const {
5267   uint64_t val = value(key);
5268   if (val != 0) {
5269     NodeCloneInfo ni(val);
5270     ni.dump();
5271   }
5272 }
--- EOF ---