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/vectornode.hpp"
  71 #include "runtime/arguments.hpp"
  72 #include "runtime/sharedRuntime.hpp"
  73 #include "runtime/signature.hpp"
  74 #include "runtime/stubRoutines.hpp"
  75 #include "runtime/timer.hpp"
  76 #include "utilities/align.hpp"
  77 #include "utilities/copy.hpp"
  78 #include "utilities/macros.hpp"
  79 #if INCLUDE_ZGC
  80 #include "gc/z/c2/zBarrierSetC2.hpp"
  81 #endif
  82 
  83 
  84 // -------------------- Compile::mach_constant_base_node -----------------------
  85 // Constant table base node singleton.
  86 MachConstantBaseNode* Compile::mach_constant_base_node() {
  87   if (_mach_constant_base_node == NULL) {
  88     _mach_constant_base_node = new MachConstantBaseNode();
  89     _mach_constant_base_node->add_req(C->root());
  90   }
  91   return _mach_constant_base_node;
  92 }
  93 
  94 
  95 /// Support for intrinsics.
  96 
  97 // Return the index at which m must be inserted (or already exists).
  98 // The sort order is by the address of the ciMethod, with is_virtual as minor key.
  99 class IntrinsicDescPair {
 100  private:
 101   ciMethod* _m;
 102   bool _is_virtual;
 103  public:
 104   IntrinsicDescPair(ciMethod* m, bool is_virtual) : _m(m), _is_virtual(is_virtual) {}
 105   static int compare(IntrinsicDescPair* const& key, CallGenerator* const& elt) {
 106     ciMethod* m= elt->method();
 107     ciMethod* key_m = key->_m;
 108     if (key_m < m)      return -1;
 109     else if (key_m > m) return 1;
 110     else {
 111       bool is_virtual = elt->is_virtual();
 112       bool key_virtual = key->_is_virtual;
 113       if (key_virtual < is_virtual)      return -1;
 114       else if (key_virtual > is_virtual) return 1;
 115       else                               return 0;
 116     }
 117   }
 118 };
 119 int Compile::intrinsic_insertion_index(ciMethod* m, bool is_virtual, bool& found) {
 120 #ifdef ASSERT
 121   for (int i = 1; i < _intrinsics->length(); i++) {
 122     CallGenerator* cg1 = _intrinsics->at(i-1);
 123     CallGenerator* cg2 = _intrinsics->at(i);
 124     assert(cg1->method() != cg2->method()
 125            ? cg1->method()     < cg2->method()
 126            : cg1->is_virtual() < cg2->is_virtual(),
 127            "compiler intrinsics list must stay sorted");
 128   }
 129 #endif
 130   IntrinsicDescPair pair(m, is_virtual);
 131   return _intrinsics->find_sorted<IntrinsicDescPair*, IntrinsicDescPair::compare>(&pair, found);
 132 }
 133 
 134 void Compile::register_intrinsic(CallGenerator* cg) {
 135   if (_intrinsics == NULL) {
 136     _intrinsics = new (comp_arena())GrowableArray<CallGenerator*>(comp_arena(), 60, 0, NULL);
 137   }
 138   int len = _intrinsics->length();
 139   bool found = false;
 140   int index = intrinsic_insertion_index(cg->method(), cg->is_virtual(), found);
 141   assert(!found, "registering twice");
 142   _intrinsics->insert_before(index, cg);
 143   assert(find_intrinsic(cg->method(), cg->is_virtual()) == cg, "registration worked");
 144 }
 145 
 146 CallGenerator* Compile::find_intrinsic(ciMethod* m, bool is_virtual) {
 147   assert(m->is_loaded(), "don't try this on unloaded methods");
 148   if (_intrinsics != NULL) {
 149     bool found = false;
 150     int index = intrinsic_insertion_index(m, is_virtual, found);
 151      if (found) {
 152       return _intrinsics->at(index);
 153     }
 154   }
 155   // Lazily create intrinsics for intrinsic IDs well-known in the runtime.
 156   if (m->intrinsic_id() != vmIntrinsics::_none &&
 157       m->intrinsic_id() <= vmIntrinsics::LAST_COMPILER_INLINE) {
 158     CallGenerator* cg = make_vm_intrinsic(m, is_virtual);
 159     if (cg != NULL) {
 160       // Save it for next time:
 161       register_intrinsic(cg);
 162       return cg;
 163     } else {
 164       gather_intrinsic_statistics(m->intrinsic_id(), is_virtual, _intrinsic_disabled);
 165     }
 166   }
 167   return NULL;
 168 }
 169 
 170 // Compile:: register_library_intrinsics and make_vm_intrinsic are defined
 171 // in library_call.cpp.
 172 
 173 
 174 #ifndef PRODUCT
 175 // statistics gathering...
 176 
 177 juint  Compile::_intrinsic_hist_count[vmIntrinsics::ID_LIMIT] = {0};
 178 jubyte Compile::_intrinsic_hist_flags[vmIntrinsics::ID_LIMIT] = {0};
 179 
 180 bool Compile::gather_intrinsic_statistics(vmIntrinsics::ID id, bool is_virtual, int flags) {
 181   assert(id > vmIntrinsics::_none && id < vmIntrinsics::ID_LIMIT, "oob");
 182   int oflags = _intrinsic_hist_flags[id];
 183   assert(flags != 0, "what happened?");
 184   if (is_virtual) {
 185     flags |= _intrinsic_virtual;
 186   }
 187   bool changed = (flags != oflags);
 188   if ((flags & _intrinsic_worked) != 0) {
 189     juint count = (_intrinsic_hist_count[id] += 1);
 190     if (count == 1) {
 191       changed = true;           // first time
 192     }
 193     // increment the overall count also:
 194     _intrinsic_hist_count[vmIntrinsics::_none] += 1;
 195   }
 196   if (changed) {
 197     if (((oflags ^ flags) & _intrinsic_virtual) != 0) {
 198       // Something changed about the intrinsic's virtuality.
 199       if ((flags & _intrinsic_virtual) != 0) {
 200         // This is the first use of this intrinsic as a virtual call.
 201         if (oflags != 0) {
 202           // We already saw it as a non-virtual, so note both cases.
 203           flags |= _intrinsic_both;
 204         }
 205       } else if ((oflags & _intrinsic_both) == 0) {
 206         // This is the first use of this intrinsic as a non-virtual
 207         flags |= _intrinsic_both;
 208       }
 209     }
 210     _intrinsic_hist_flags[id] = (jubyte) (oflags | flags);
 211   }
 212   // update the overall flags also:
 213   _intrinsic_hist_flags[vmIntrinsics::_none] |= (jubyte) flags;
 214   return changed;
 215 }
 216 
 217 static char* format_flags(int flags, char* buf) {
 218   buf[0] = 0;
 219   if ((flags & Compile::_intrinsic_worked) != 0)    strcat(buf, ",worked");
 220   if ((flags & Compile::_intrinsic_failed) != 0)    strcat(buf, ",failed");
 221   if ((flags & Compile::_intrinsic_disabled) != 0)  strcat(buf, ",disabled");
 222   if ((flags & Compile::_intrinsic_virtual) != 0)   strcat(buf, ",virtual");
 223   if ((flags & Compile::_intrinsic_both) != 0)      strcat(buf, ",nonvirtual");
 224   if (buf[0] == 0)  strcat(buf, ",");
 225   assert(buf[0] == ',', "must be");
 226   return &buf[1];
 227 }
 228 
 229 void Compile::print_intrinsic_statistics() {
 230   char flagsbuf[100];
 231   ttyLocker ttyl;
 232   if (xtty != NULL)  xtty->head("statistics type='intrinsic'");
 233   tty->print_cr("Compiler intrinsic usage:");
 234   juint total = _intrinsic_hist_count[vmIntrinsics::_none];
 235   if (total == 0)  total = 1;  // avoid div0 in case of no successes
 236   #define PRINT_STAT_LINE(name, c, f) \
 237     tty->print_cr("  %4d (%4.1f%%) %s (%s)", (int)(c), ((c) * 100.0) / total, name, f);
 238   for (int index = 1 + (int)vmIntrinsics::_none; index < (int)vmIntrinsics::ID_LIMIT; index++) {
 239     vmIntrinsics::ID id = (vmIntrinsics::ID) index;
 240     int   flags = _intrinsic_hist_flags[id];
 241     juint count = _intrinsic_hist_count[id];
 242     if ((flags | count) != 0) {
 243       PRINT_STAT_LINE(vmIntrinsics::name_at(id), count, format_flags(flags, flagsbuf));
 244     }
 245   }
 246   PRINT_STAT_LINE("total", total, format_flags(_intrinsic_hist_flags[vmIntrinsics::_none], flagsbuf));
 247   if (xtty != NULL)  xtty->tail("statistics");
 248 }
 249 
 250 void Compile::print_statistics() {
 251   { ttyLocker ttyl;
 252     if (xtty != NULL)  xtty->head("statistics type='opto'");
 253     Parse::print_statistics();
 254     PhaseCCP::print_statistics();
 255     PhaseRegAlloc::print_statistics();
 256     Scheduling::print_statistics();
 257     PhasePeephole::print_statistics();
 258     PhaseIdealLoop::print_statistics();
 259     if (xtty != NULL)  xtty->tail("statistics");
 260   }
 261   if (_intrinsic_hist_flags[vmIntrinsics::_none] != 0) {
 262     // put this under its own <statistics> element.
 263     print_intrinsic_statistics();
 264   }
 265 }
 266 #endif //PRODUCT
 267 
 268 // Support for bundling info
 269 Bundle* Compile::node_bundling(const Node *n) {
 270   assert(valid_bundle_info(n), "oob");
 271   return &_node_bundling_base[n->_idx];
 272 }
 273 
 274 bool Compile::valid_bundle_info(const Node *n) {
 275   return (_node_bundling_limit > n->_idx);
 276 }
 277 
 278 
 279 void Compile::gvn_replace_by(Node* n, Node* nn) {
 280   for (DUIterator_Last imin, i = n->last_outs(imin); i >= imin; ) {
 281     Node* use = n->last_out(i);
 282     bool is_in_table = initial_gvn()->hash_delete(use);
 283     uint uses_found = 0;
 284     for (uint j = 0; j < use->len(); j++) {
 285       if (use->in(j) == n) {
 286         if (j < use->req())
 287           use->set_req(j, nn);
 288         else
 289           use->set_prec(j, nn);
 290         uses_found++;
 291       }
 292     }
 293     if (is_in_table) {
 294       // reinsert into table
 295       initial_gvn()->hash_find_insert(use);
 296     }
 297     record_for_igvn(use);
 298     i -= uses_found;    // we deleted 1 or more copies of this edge
 299   }
 300 }
 301 
 302 
 303 static inline bool not_a_node(const Node* n) {
 304   if (n == NULL)                   return true;
 305   if (((intptr_t)n & 1) != 0)      return true;  // uninitialized, etc.
 306   if (*(address*)n == badAddress)  return true;  // kill by Node::destruct
 307   return false;
 308 }
 309 
 310 // Identify all nodes that are reachable from below, useful.
 311 // Use breadth-first pass that records state in a Unique_Node_List,
 312 // recursive traversal is slower.
 313 void Compile::identify_useful_nodes(Unique_Node_List &useful) {
 314   int estimated_worklist_size = live_nodes();
 315   useful.map( estimated_worklist_size, NULL );  // preallocate space
 316 
 317   // Initialize worklist
 318   if (root() != NULL)     { useful.push(root()); }
 319   // If 'top' is cached, declare it useful to preserve cached node
 320   if( cached_top_node() ) { useful.push(cached_top_node()); }
 321 
 322   // Push all useful nodes onto the list, breadthfirst
 323   for( uint next = 0; next < useful.size(); ++next ) {
 324     assert( next < unique(), "Unique useful nodes < total nodes");
 325     Node *n  = useful.at(next);
 326     uint max = n->len();
 327     for( uint i = 0; i < max; ++i ) {
 328       Node *m = n->in(i);
 329       if (not_a_node(m))  continue;
 330       useful.push(m);
 331     }
 332   }
 333 }
 334 
 335 // Update dead_node_list with any missing dead nodes using useful
 336 // list. Consider all non-useful nodes to be useless i.e., dead nodes.
 337 void Compile::update_dead_node_list(Unique_Node_List &useful) {
 338   uint max_idx = unique();
 339   VectorSet& useful_node_set = useful.member_set();
 340 
 341   for (uint node_idx = 0; node_idx < max_idx; node_idx++) {
 342     // If node with index node_idx is not in useful set,
 343     // mark it as dead in dead node list.
 344     if (! useful_node_set.test(node_idx) ) {
 345       record_dead_node(node_idx);
 346     }
 347   }
 348 }
 349 
 350 void Compile::remove_useless_late_inlines(GrowableArray<CallGenerator*>* inlines, Unique_Node_List &useful) {
 351   int shift = 0;
 352   for (int i = 0; i < inlines->length(); i++) {
 353     CallGenerator* cg = inlines->at(i);
 354     CallNode* call = cg->call_node();
 355     if (shift > 0) {
 356       inlines->at_put(i-shift, cg);
 357     }
 358     if (!useful.member(call)) {
 359       shift++;
 360     }
 361   }
 362   inlines->trunc_to(inlines->length()-shift);
 363 }
 364 
 365 // Disconnect all useless nodes by disconnecting those at the boundary.
 366 void Compile::remove_useless_nodes(Unique_Node_List &useful) {
 367   uint next = 0;
 368   while (next < useful.size()) {
 369     Node *n = useful.at(next++);
 370     if (n->is_SafePoint()) {
 371       // We're done with a parsing phase. Replaced nodes are not valid
 372       // beyond that point.
 373       n->as_SafePoint()->delete_replaced_nodes();
 374     }
 375     // Use raw traversal of out edges since this code removes out edges
 376     int max = n->outcnt();
 377     for (int j = 0; j < max; ++j) {
 378       Node* child = n->raw_out(j);
 379       if (! useful.member(child)) {
 380         assert(!child->is_top() || child != top(),
 381                "If top is cached in Compile object it is in useful list");
 382         // Only need to remove this out-edge to the useless node
 383         n->raw_del_out(j);
 384         --j;
 385         --max;
 386       }
 387     }
 388     if (n->outcnt() == 1 && n->has_special_unique_user()) {
 389       record_for_igvn(n->unique_out());
 390     }
 391   }
 392   // Remove useless macro and predicate opaq nodes
 393   for (int i = C->macro_count()-1; i >= 0; i--) {
 394     Node* n = C->macro_node(i);
 395     if (!useful.member(n)) {
 396       remove_macro_node(n);
 397     }
 398   }
 399   // Remove useless CastII nodes with range check dependency
 400   for (int i = range_check_cast_count() - 1; i >= 0; i--) {
 401     Node* cast = range_check_cast_node(i);
 402     if (!useful.member(cast)) {
 403       remove_range_check_cast(cast);
 404     }
 405   }
 406   // Remove useless expensive nodes
 407   for (int i = C->expensive_count()-1; i >= 0; i--) {
 408     Node* n = C->expensive_node(i);
 409     if (!useful.member(n)) {
 410       remove_expensive_node(n);
 411     }
 412   }
 413   // Remove useless Opaque4 nodes
 414   for (int i = opaque4_count() - 1; i >= 0; i--) {
 415     Node* opaq = opaque4_node(i);
 416     if (!useful.member(opaq)) {
 417       remove_opaque4_node(opaq);
 418     }
 419   }
 420   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 421   bs->eliminate_useless_gc_barriers(useful, this);
 422   // clean up the late inline lists
 423   remove_useless_late_inlines(&_string_late_inlines, useful);
 424   remove_useless_late_inlines(&_boxing_late_inlines, useful);
 425   remove_useless_late_inlines(&_late_inlines, useful);
 426   debug_only(verify_graph_edges(true/*check for no_dead_code*/);)
 427 }
 428 
 429 //------------------------------frame_size_in_words-----------------------------
 430 // frame_slots in units of words
 431 int Compile::frame_size_in_words() const {
 432   // shift is 0 in LP32 and 1 in LP64
 433   const int shift = (LogBytesPerWord - LogBytesPerInt);
 434   int words = _frame_slots >> shift;
 435   assert( words << shift == _frame_slots, "frame size must be properly aligned in LP64" );
 436   return words;
 437 }
 438 
 439 // To bang the stack of this compiled method we use the stack size
 440 // that the interpreter would need in case of a deoptimization. This
 441 // removes the need to bang the stack in the deoptimization blob which
 442 // in turn simplifies stack overflow handling.
 443 int Compile::bang_size_in_bytes() const {
 444   return MAX2(frame_size_in_bytes() + os::extra_bang_size_in_bytes(), _interpreter_frame_size);
 445 }
 446 
 447 // ============================================================================
 448 //------------------------------CompileWrapper---------------------------------
 449 class CompileWrapper : public StackObj {
 450   Compile *const _compile;
 451  public:
 452   CompileWrapper(Compile* compile);
 453 
 454   ~CompileWrapper();
 455 };
 456 
 457 CompileWrapper::CompileWrapper(Compile* compile) : _compile(compile) {
 458   // the Compile* pointer is stored in the current ciEnv:
 459   ciEnv* env = compile->env();
 460   assert(env == ciEnv::current(), "must already be a ciEnv active");
 461   assert(env->compiler_data() == NULL, "compile already active?");
 462   env->set_compiler_data(compile);
 463   assert(compile == Compile::current(), "sanity");
 464 
 465   compile->set_type_dict(NULL);
 466   compile->set_clone_map(new Dict(cmpkey, hashkey, _compile->comp_arena()));
 467   compile->clone_map().set_clone_idx(0);
 468   compile->set_type_hwm(NULL);
 469   compile->set_type_last_size(0);
 470   compile->set_last_tf(NULL, NULL);
 471   compile->set_indexSet_arena(NULL);
 472   compile->set_indexSet_free_block_list(NULL);
 473   compile->init_type_arena();
 474   Type::Initialize(compile);
 475   _compile->set_scratch_buffer_blob(NULL);
 476   _compile->begin_method();
 477   _compile->clone_map().set_debug(_compile->has_method() && _compile->directive()->CloneMapDebugOption);
 478 }
 479 CompileWrapper::~CompileWrapper() {
 480   _compile->end_method();
 481   if (_compile->scratch_buffer_blob() != NULL)
 482     BufferBlob::free(_compile->scratch_buffer_blob());
 483   _compile->env()->set_compiler_data(NULL);
 484 }
 485 
 486 
 487 //----------------------------print_compile_messages---------------------------
 488 void Compile::print_compile_messages() {
 489 #ifndef PRODUCT
 490   // Check if recompiling
 491   if (_subsume_loads == false && PrintOpto) {
 492     // Recompiling without allowing machine instructions to subsume loads
 493     tty->print_cr("*********************************************************");
 494     tty->print_cr("** Bailout: Recompile without subsuming loads          **");
 495     tty->print_cr("*********************************************************");
 496   }
 497   if (_do_escape_analysis != DoEscapeAnalysis && PrintOpto) {
 498     // Recompiling without escape analysis
 499     tty->print_cr("*********************************************************");
 500     tty->print_cr("** Bailout: Recompile without escape analysis          **");
 501     tty->print_cr("*********************************************************");
 502   }
 503   if (_eliminate_boxing != EliminateAutoBox && PrintOpto) {
 504     // Recompiling without boxing elimination
 505     tty->print_cr("*********************************************************");
 506     tty->print_cr("** Bailout: Recompile without boxing elimination       **");
 507     tty->print_cr("*********************************************************");
 508   }
 509   if (C->directive()->BreakAtCompileOption) {
 510     // Open the debugger when compiling this method.
 511     tty->print("### Breaking when compiling: ");
 512     method()->print_short_name();
 513     tty->cr();
 514     BREAKPOINT;
 515   }
 516 
 517   if( PrintOpto ) {
 518     if (is_osr_compilation()) {
 519       tty->print("[OSR]%3d", _compile_id);
 520     } else {
 521       tty->print("%3d", _compile_id);
 522     }
 523   }
 524 #endif
 525 }
 526 
 527 
 528 //-----------------------init_scratch_buffer_blob------------------------------
 529 // Construct a temporary BufferBlob and cache it for this compile.
 530 void Compile::init_scratch_buffer_blob(int const_size) {
 531   // If there is already a scratch buffer blob allocated and the
 532   // constant section is big enough, use it.  Otherwise free the
 533   // current and allocate a new one.
 534   BufferBlob* blob = scratch_buffer_blob();
 535   if ((blob != NULL) && (const_size <= _scratch_const_size)) {
 536     // Use the current blob.
 537   } else {
 538     if (blob != NULL) {
 539       BufferBlob::free(blob);
 540     }
 541 
 542     ResourceMark rm;
 543     _scratch_const_size = const_size;
 544     int size = C2Compiler::initial_code_buffer_size(const_size);
 545     blob = BufferBlob::create("Compile::scratch_buffer", size);
 546     // Record the buffer blob for next time.
 547     set_scratch_buffer_blob(blob);
 548     // Have we run out of code space?
 549     if (scratch_buffer_blob() == NULL) {
 550       // Let CompilerBroker disable further compilations.
 551       record_failure("Not enough space for scratch buffer in CodeCache");
 552       return;
 553     }
 554   }
 555 
 556   // Initialize the relocation buffers
 557   relocInfo* locs_buf = (relocInfo*) blob->content_end() - MAX_locs_size;
 558   set_scratch_locs_memory(locs_buf);
 559 }
 560 
 561 
 562 //-----------------------scratch_emit_size-------------------------------------
 563 // Helper function that computes size by emitting code
 564 uint Compile::scratch_emit_size(const Node* n) {
 565   // Start scratch_emit_size section.
 566   set_in_scratch_emit_size(true);
 567 
 568   // Emit into a trash buffer and count bytes emitted.
 569   // This is a pretty expensive way to compute a size,
 570   // but it works well enough if seldom used.
 571   // All common fixed-size instructions are given a size
 572   // method by the AD file.
 573   // Note that the scratch buffer blob and locs memory are
 574   // allocated at the beginning of the compile task, and
 575   // may be shared by several calls to scratch_emit_size.
 576   // The allocation of the scratch buffer blob is particularly
 577   // expensive, since it has to grab the code cache lock.
 578   BufferBlob* blob = this->scratch_buffer_blob();
 579   assert(blob != NULL, "Initialize BufferBlob at start");
 580   assert(blob->size() > MAX_inst_size, "sanity");
 581   relocInfo* locs_buf = scratch_locs_memory();
 582   address blob_begin = blob->content_begin();
 583   address blob_end   = (address)locs_buf;
 584   assert(blob->contains(blob_end), "sanity");
 585   CodeBuffer buf(blob_begin, blob_end - blob_begin);
 586   buf.initialize_consts_size(_scratch_const_size);
 587   buf.initialize_stubs_size(MAX_stubs_size);
 588   assert(locs_buf != NULL, "sanity");
 589   int lsize = MAX_locs_size / 3;
 590   buf.consts()->initialize_shared_locs(&locs_buf[lsize * 0], lsize);
 591   buf.insts()->initialize_shared_locs( &locs_buf[lsize * 1], lsize);
 592   buf.stubs()->initialize_shared_locs( &locs_buf[lsize * 2], lsize);
 593   // Mark as scratch buffer.
 594   buf.consts()->set_scratch_emit();
 595   buf.insts()->set_scratch_emit();
 596   buf.stubs()->set_scratch_emit();
 597 
 598   // Do the emission.
 599 
 600   Label fakeL; // Fake label for branch instructions.
 601   Label*   saveL = NULL;
 602   uint save_bnum = 0;
 603   bool is_branch = n->is_MachBranch();
 604   if (is_branch) {
 605     MacroAssembler masm(&buf);
 606     masm.bind(fakeL);
 607     n->as_MachBranch()->save_label(&saveL, &save_bnum);
 608     n->as_MachBranch()->label_set(&fakeL, 0);
 609   }
 610   n->emit(buf, this->regalloc());
 611 
 612   // Emitting into the scratch buffer should not fail
 613   assert (!failing(), "Must not have pending failure. Reason is: %s", failure_reason());
 614 
 615   if (is_branch) // Restore label.
 616     n->as_MachBranch()->label_set(saveL, save_bnum);
 617 
 618   // End scratch_emit_size section.
 619   set_in_scratch_emit_size(false);
 620 
 621   return buf.insts_size();
 622 }
 623 
 624 
 625 // ============================================================================
 626 //------------------------------Compile standard-------------------------------
 627 debug_only( int Compile::_debug_idx = 100000; )
 628 
 629 // Compile a method.  entry_bci is -1 for normal compilations and indicates
 630 // the continuation bci for on stack replacement.
 631 
 632 
 633 Compile::Compile( ciEnv* ci_env, C2Compiler* compiler, ciMethod* target, int osr_bci,
 634                   bool subsume_loads, bool do_escape_analysis, bool eliminate_boxing, DirectiveSet* directive)
 635                 : Phase(Compiler),
 636                   _compile_id(ci_env->compile_id()),
 637                   _save_argument_registers(false),
 638                   _subsume_loads(subsume_loads),
 639                   _do_escape_analysis(do_escape_analysis),
 640                   _eliminate_boxing(eliminate_boxing),
 641                   _method(target),
 642                   _entry_bci(osr_bci),
 643                   _stub_function(NULL),
 644                   _stub_name(NULL),
 645                   _stub_entry_point(NULL),
 646                   _max_node_limit(MaxNodeLimit),
 647                   _orig_pc_slot(0),
 648                   _orig_pc_slot_offset_in_bytes(0),
 649                   _inlining_progress(false),
 650                   _inlining_incrementally(false),
 651                   _do_cleanup(false),
 652                   _has_reserved_stack_access(target->has_reserved_stack_access()),
 653 #ifndef PRODUCT
 654                   _trace_opto_output(directive->TraceOptoOutputOption),
 655 #endif
 656                   _has_method_handle_invokes(false),
 657                   _comp_arena(mtCompiler),
 658                   _barrier_set_state(BarrierSet::barrier_set()->barrier_set_c2()->create_barrier_state(comp_arena())),
 659                   _env(ci_env),
 660                   _directive(directive),
 661                   _log(ci_env->log()),
 662                   _failure_reason(NULL),
 663                   _congraph(NULL),
 664 #ifndef PRODUCT
 665                   _printer(IdealGraphPrinter::printer()),
 666 #endif
 667                   _dead_node_list(comp_arena()),
 668                   _dead_node_count(0),
 669                   _node_arena(mtCompiler),
 670                   _old_arena(mtCompiler),
 671                   _mach_constant_base_node(NULL),
 672                   _Compile_types(mtCompiler),
 673                   _initial_gvn(NULL),
 674                   _for_igvn(NULL),
 675                   _warm_calls(NULL),
 676                   _late_inlines(comp_arena(), 2, 0, NULL),
 677                   _string_late_inlines(comp_arena(), 2, 0, NULL),
 678                   _boxing_late_inlines(comp_arena(), 2, 0, NULL),
 679                   _late_inlines_pos(0),
 680                   _number_of_mh_late_inlines(0),
 681                   _print_inlining_stream(NULL),
 682                   _print_inlining_list(NULL),
 683                   _print_inlining_idx(0),
 684                   _print_inlining_output(NULL),
 685                   _replay_inline_data(NULL),
 686                   _java_calls(0),
 687                   _inner_loops(0),
 688                   _interpreter_frame_size(0),
 689                   _node_bundling_limit(0),
 690                   _node_bundling_base(NULL),
 691                   _code_buffer("Compile::Fill_buffer"),
 692                   _scratch_const_size(-1),
 693                   _in_scratch_emit_size(false)
 694 #ifndef PRODUCT
 695                   , _in_dump_cnt(0)
 696 #endif
 697 {
 698   C = this;
 699 #ifndef PRODUCT
 700   if (_printer != NULL) {
 701     _printer->set_compile(this);
 702   }
 703 #endif
 704   CompileWrapper cw(this);
 705 
 706   if (CITimeVerbose) {
 707     tty->print(" ");
 708     target->holder()->name()->print();
 709     tty->print(".");
 710     target->print_short_name();
 711     tty->print("  ");
 712   }
 713   TraceTime t1("Total compilation time", &_t_totalCompilation, CITime, CITimeVerbose);
 714   TraceTime t2(NULL, &_t_methodCompilation, CITime, false);
 715 
 716 #if defined(SUPPORT_ASSEMBLY) || defined(SUPPORT_ABSTRACT_ASSEMBLY)
 717   bool print_opto_assembly = directive->PrintOptoAssemblyOption;
 718   // We can always print a disassembly, either abstract (hex dump) or
 719   // with the help of a suitable hsdis library. Thus, we should not
 720   // couple print_assembly and print_opto_assembly controls.
 721   // But: always print opto and regular assembly on compile command 'print'.
 722   bool print_assembly = directive->PrintAssemblyOption;
 723   set_print_assembly(print_opto_assembly || print_assembly);
 724 #else
 725   set_print_assembly(false); // must initialize.
 726 #endif
 727 
 728 #ifndef PRODUCT
 729   set_parsed_irreducible_loop(false);
 730 
 731   if (directive->ReplayInlineOption) {
 732     _replay_inline_data = ciReplay::load_inline_data(method(), entry_bci(), ci_env->comp_level());
 733   }
 734 #endif
 735   set_print_inlining(directive->PrintInliningOption || PrintOptoInlining);
 736   set_print_intrinsics(directive->PrintIntrinsicsOption);
 737   set_has_irreducible_loop(true); // conservative until build_loop_tree() reset it
 738 
 739   if (ProfileTraps RTM_OPT_ONLY( || UseRTMLocking )) {
 740     // Make sure the method being compiled gets its own MDO,
 741     // so we can at least track the decompile_count().
 742     // Need MDO to record RTM code generation state.
 743     method()->ensure_method_data();
 744   }
 745 
 746   Init(::AliasLevel);
 747 
 748 
 749   print_compile_messages();
 750 
 751   _ilt = InlineTree::build_inline_tree_root();
 752 
 753   // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
 754   assert(num_alias_types() >= AliasIdxRaw, "");
 755 
 756 #define MINIMUM_NODE_HASH  1023
 757   // Node list that Iterative GVN will start with
 758   Unique_Node_List for_igvn(comp_arena());
 759   set_for_igvn(&for_igvn);
 760 
 761   // GVN that will be run immediately on new nodes
 762   uint estimated_size = method()->code_size()*4+64;
 763   estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
 764   PhaseGVN gvn(node_arena(), estimated_size);
 765   set_initial_gvn(&gvn);
 766 
 767   print_inlining_init();
 768   { // Scope for timing the parser
 769     TracePhase tp("parse", &timers[_t_parser]);
 770 
 771     // Put top into the hash table ASAP.
 772     initial_gvn()->transform_no_reclaim(top());
 773 
 774     // Set up tf(), start(), and find a CallGenerator.
 775     CallGenerator* cg = NULL;
 776     if (is_osr_compilation()) {
 777       const TypeTuple *domain = StartOSRNode::osr_domain();
 778       const TypeTuple *range = TypeTuple::make_range(method()->signature());
 779       init_tf(TypeFunc::make(domain, range));
 780       StartNode* s = new StartOSRNode(root(), domain);
 781       initial_gvn()->set_type_bottom(s);
 782       init_start(s);
 783       cg = CallGenerator::for_osr(method(), entry_bci());
 784     } else {
 785       // Normal case.
 786       init_tf(TypeFunc::make(method()));
 787       StartNode* s = new StartNode(root(), tf()->domain());
 788       initial_gvn()->set_type_bottom(s);
 789       init_start(s);
 790       if (method()->intrinsic_id() == vmIntrinsics::_Reference_get) {
 791         // With java.lang.ref.reference.get() we must go through the
 792         // intrinsic - even when get() is the root
 793         // method of the compile - so that, if necessary, the value in
 794         // the referent field of the reference object gets recorded by
 795         // the pre-barrier code.
 796         cg = find_intrinsic(method(), false);
 797       }
 798       if (cg == NULL) {
 799         float past_uses = method()->interpreter_invocation_count();
 800         float expected_uses = past_uses;
 801         cg = CallGenerator::for_inline(method(), expected_uses);
 802       }
 803     }
 804     if (failing())  return;
 805     if (cg == NULL) {
 806       record_method_not_compilable("cannot parse method");
 807       return;
 808     }
 809     JVMState* jvms = build_start_state(start(), tf());
 810     if ((jvms = cg->generate(jvms)) == NULL) {
 811       if (!failure_reason_is(C2Compiler::retry_class_loading_during_parsing())) {
 812         record_method_not_compilable("method parse failed");
 813       }
 814       return;
 815     }
 816     GraphKit kit(jvms);
 817 
 818     if (!kit.stopped()) {
 819       // Accept return values, and transfer control we know not where.
 820       // This is done by a special, unique ReturnNode bound to root.
 821       return_values(kit.jvms());
 822     }
 823 
 824     if (kit.has_exceptions()) {
 825       // Any exceptions that escape from this call must be rethrown
 826       // to whatever caller is dynamically above us on the stack.
 827       // This is done by a special, unique RethrowNode bound to root.
 828       rethrow_exceptions(kit.transfer_exceptions_into_jvms());
 829     }
 830 
 831     assert(IncrementalInline || (_late_inlines.length() == 0 && !has_mh_late_inlines()), "incremental inlining is off");
 832 
 833     if (_late_inlines.length() == 0 && !has_mh_late_inlines() && !failing() && has_stringbuilder()) {
 834       inline_string_calls(true);
 835     }
 836 
 837     if (failing())  return;
 838 
 839     print_method(PHASE_BEFORE_REMOVEUSELESS, 3);
 840 
 841     // Remove clutter produced by parsing.
 842     if (!failing()) {
 843       ResourceMark rm;
 844       PhaseRemoveUseless pru(initial_gvn(), &for_igvn);
 845     }
 846   }
 847 
 848   // Note:  Large methods are capped off in do_one_bytecode().
 849   if (failing())  return;
 850 
 851   // After parsing, node notes are no longer automagic.
 852   // They must be propagated by register_new_node_with_optimizer(),
 853   // clone(), or the like.
 854   set_default_node_notes(NULL);
 855 
 856   for (;;) {
 857     int successes = Inline_Warm();
 858     if (failing())  return;
 859     if (successes == 0)  break;
 860   }
 861 
 862   // Drain the list.
 863   Finish_Warm();
 864 #ifndef PRODUCT
 865   if (_printer && _printer->should_print(1)) {
 866     _printer->print_inlining();
 867   }
 868 #endif
 869 
 870   if (failing())  return;
 871   NOT_PRODUCT( verify_graph_edges(); )
 872 
 873   // Now optimize
 874   Optimize();
 875   if (failing())  return;
 876   NOT_PRODUCT( verify_graph_edges(); )
 877 
 878 #ifndef PRODUCT
 879   if (PrintIdeal) {
 880     ttyLocker ttyl;  // keep the following output all in one block
 881     // This output goes directly to the tty, not the compiler log.
 882     // To enable tools to match it up with the compilation activity,
 883     // be sure to tag this tty output with the compile ID.
 884     if (xtty != NULL) {
 885       xtty->head("ideal compile_id='%d'%s", compile_id(),
 886                  is_osr_compilation()    ? " compile_kind='osr'" :
 887                  "");
 888     }
 889     root()->dump(9999);
 890     if (xtty != NULL) {
 891       xtty->tail("ideal");
 892     }
 893   }
 894 #endif
 895 
 896 #ifdef ASSERT
 897   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 898   bs->verify_gc_barriers(this, BarrierSetC2::BeforeCodeGen);
 899 #endif
 900 
 901   // Dump compilation data to replay it.
 902   if (directive->DumpReplayOption) {
 903     env()->dump_replay_data(_compile_id);
 904   }
 905   if (directive->DumpInlineOption && (ilt() != NULL)) {
 906     env()->dump_inline_data(_compile_id);
 907   }
 908 
 909   // Now that we know the size of all the monitors we can add a fixed slot
 910   // for the original deopt pc.
 911 
 912   _orig_pc_slot =  fixed_slots();
 913   int next_slot = _orig_pc_slot + (sizeof(address) / VMRegImpl::stack_slot_size);
 914   set_fixed_slots(next_slot);
 915 
 916   // Compute when to use implicit null checks. Used by matching trap based
 917   // nodes and NullCheck optimization.
 918   set_allowed_deopt_reasons();
 919 
 920   // Now generate code
 921   Code_Gen();
 922   if (failing())  return;
 923 
 924   // Check if we want to skip execution of all compiled code.
 925   {
 926 #ifndef PRODUCT
 927     if (OptoNoExecute) {
 928       record_method_not_compilable("+OptoNoExecute");  // Flag as failed
 929       return;
 930     }
 931 #endif
 932     TracePhase tp("install_code", &timers[_t_registerMethod]);
 933 
 934     if (is_osr_compilation()) {
 935       _code_offsets.set_value(CodeOffsets::Verified_Entry, 0);
 936       _code_offsets.set_value(CodeOffsets::OSR_Entry, _first_block_size);
 937     } else {
 938       _code_offsets.set_value(CodeOffsets::Verified_Entry, _first_block_size);
 939       _code_offsets.set_value(CodeOffsets::OSR_Entry, 0);
 940     }
 941 
 942     env()->register_method(_method, _entry_bci,
 943                            &_code_offsets,
 944                            _orig_pc_slot_offset_in_bytes,
 945                            code_buffer(),
 946                            frame_size_in_words(), _oop_map_set,
 947                            &_handler_table, &_inc_table,
 948                            compiler,
 949                            has_unsafe_access(),
 950                            SharedRuntime::is_wide_vector(max_vector_size()),
 951                            rtm_state()
 952                            );
 953 
 954     if (log() != NULL) // Print code cache state into compiler log
 955       log()->code_cache_state();
 956   }
 957 }
 958 
 959 //------------------------------Compile----------------------------------------
 960 // Compile a runtime stub
 961 Compile::Compile( ciEnv* ci_env,
 962                   TypeFunc_generator generator,
 963                   address stub_function,
 964                   const char *stub_name,
 965                   int is_fancy_jump,
 966                   bool pass_tls,
 967                   bool save_arg_registers,
 968                   bool return_pc,
 969                   DirectiveSet* directive)
 970   : Phase(Compiler),
 971     _compile_id(0),
 972     _save_argument_registers(save_arg_registers),
 973     _subsume_loads(true),
 974     _do_escape_analysis(false),
 975     _eliminate_boxing(false),
 976     _method(NULL),
 977     _entry_bci(InvocationEntryBci),
 978     _stub_function(stub_function),
 979     _stub_name(stub_name),
 980     _stub_entry_point(NULL),
 981     _max_node_limit(MaxNodeLimit),
 982     _orig_pc_slot(0),
 983     _orig_pc_slot_offset_in_bytes(0),
 984     _inlining_progress(false),
 985     _inlining_incrementally(false),
 986     _has_reserved_stack_access(false),
 987 #ifndef PRODUCT
 988     _trace_opto_output(directive->TraceOptoOutputOption),
 989 #endif
 990     _has_method_handle_invokes(false),
 991     _comp_arena(mtCompiler),
 992     _env(ci_env),
 993     _directive(directive),
 994     _log(ci_env->log()),
 995     _failure_reason(NULL),
 996     _congraph(NULL),
 997 #ifndef PRODUCT
 998     _printer(NULL),
 999 #endif
1000     _dead_node_list(comp_arena()),
1001     _dead_node_count(0),
1002     _node_arena(mtCompiler),
1003     _old_arena(mtCompiler),
1004     _mach_constant_base_node(NULL),
1005     _Compile_types(mtCompiler),
1006     _initial_gvn(NULL),
1007     _for_igvn(NULL),
1008     _warm_calls(NULL),
1009     _number_of_mh_late_inlines(0),
1010     _print_inlining_stream(NULL),
1011     _print_inlining_list(NULL),
1012     _print_inlining_idx(0),
1013     _print_inlining_output(NULL),
1014     _replay_inline_data(NULL),
1015     _java_calls(0),
1016     _inner_loops(0),
1017     _interpreter_frame_size(0),
1018     _node_bundling_limit(0),
1019     _node_bundling_base(NULL),
1020     _code_buffer("Compile::Fill_buffer"),
1021 #ifndef PRODUCT
1022     _in_dump_cnt(0),
1023 #endif
1024     _allowed_reasons(0) {
1025   C = this;
1026 
1027   TraceTime t1(NULL, &_t_totalCompilation, CITime, false);
1028   TraceTime t2(NULL, &_t_stubCompilation, CITime, false);
1029 
1030 #ifndef PRODUCT
1031   set_print_assembly(PrintFrameConverterAssembly);
1032   set_parsed_irreducible_loop(false);
1033 #else
1034   set_print_assembly(false); // Must initialize.
1035 #endif
1036   set_has_irreducible_loop(false); // no loops
1037 
1038   CompileWrapper cw(this);
1039   Init(/*AliasLevel=*/ 0);
1040   init_tf((*generator)());
1041 
1042   {
1043     // The following is a dummy for the sake of GraphKit::gen_stub
1044     Unique_Node_List for_igvn(comp_arena());
1045     set_for_igvn(&for_igvn);  // not used, but some GraphKit guys push on this
1046     PhaseGVN gvn(Thread::current()->resource_area(),255);
1047     set_initial_gvn(&gvn);    // not significant, but GraphKit guys use it pervasively
1048     gvn.transform_no_reclaim(top());
1049 
1050     GraphKit kit;
1051     kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
1052   }
1053 
1054   NOT_PRODUCT( verify_graph_edges(); )
1055   Code_Gen();
1056   if (failing())  return;
1057 
1058 
1059   // Entry point will be accessed using compile->stub_entry_point();
1060   if (code_buffer() == NULL) {
1061     Matcher::soft_match_failure();
1062   } else {
1063     if (PrintAssembly && (WizardMode || Verbose))
1064       tty->print_cr("### Stub::%s", stub_name);
1065 
1066     if (!failing()) {
1067       assert(_fixed_slots == 0, "no fixed slots used for runtime stubs");
1068 
1069       // Make the NMethod
1070       // For now we mark the frame as never safe for profile stackwalking
1071       RuntimeStub *rs = RuntimeStub::new_runtime_stub(stub_name,
1072                                                       code_buffer(),
1073                                                       CodeOffsets::frame_never_safe,
1074                                                       // _code_offsets.value(CodeOffsets::Frame_Complete),
1075                                                       frame_size_in_words(),
1076                                                       _oop_map_set,
1077                                                       save_arg_registers);
1078       assert(rs != NULL && rs->is_runtime_stub(), "sanity check");
1079 
1080       _stub_entry_point = rs->entry_point();
1081     }
1082   }
1083 }
1084 
1085 //------------------------------Init-------------------------------------------
1086 // Prepare for a single compilation
1087 void Compile::Init(int aliaslevel) {
1088   _unique  = 0;
1089   _regalloc = NULL;
1090 
1091   _tf      = NULL;  // filled in later
1092   _top     = NULL;  // cached later
1093   _matcher = NULL;  // filled in later
1094   _cfg     = NULL;  // filled in later
1095 
1096   set_24_bit_selection_and_mode(Use24BitFP, false);
1097 
1098   _node_note_array = NULL;
1099   _default_node_notes = NULL;
1100   DEBUG_ONLY( _modified_nodes = NULL; ) // Used in Optimize()
1101 
1102   _immutable_memory = NULL; // filled in at first inquiry
1103 
1104   // Globally visible Nodes
1105   // First set TOP to NULL to give safe behavior during creation of RootNode
1106   set_cached_top_node(NULL);
1107   set_root(new RootNode());
1108   // Now that you have a Root to point to, create the real TOP
1109   set_cached_top_node( new ConNode(Type::TOP) );
1110   set_recent_alloc(NULL, NULL);
1111 
1112   // Create Debug Information Recorder to record scopes, oopmaps, etc.
1113   env()->set_oop_recorder(new OopRecorder(env()->arena()));
1114   env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
1115   env()->set_dependencies(new Dependencies(env()));
1116 
1117   _fixed_slots = 0;
1118   set_has_split_ifs(false);
1119   set_has_loops(has_method() && method()->has_loops()); // first approximation
1120   set_has_stringbuilder(false);
1121   set_has_boxed_value(false);
1122   _trap_can_recompile = false;  // no traps emitted yet
1123   _major_progress = true; // start out assuming good things will happen
1124   set_has_unsafe_access(false);
1125   set_max_vector_size(0);
1126   set_clear_upper_avx(false);  //false as default for clear upper bits of ymm registers
1127   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
1128   set_decompile_count(0);
1129 
1130   set_do_freq_based_layout(_directive->BlockLayoutByFrequencyOption);
1131   _loop_opts_cnt = LoopOptsCount;
1132   set_do_inlining(Inline);
1133   set_max_inline_size(MaxInlineSize);
1134   set_freq_inline_size(FreqInlineSize);
1135   set_do_scheduling(OptoScheduling);
1136   set_do_count_invocations(false);
1137   set_do_method_data_update(false);
1138 
1139   set_do_vector_loop(false);
1140 
1141   if (AllowVectorizeOnDemand) {
1142     if (has_method() && (_directive->VectorizeOption || _directive->VectorizeDebugOption)) {
1143       set_do_vector_loop(true);
1144       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());})
1145     } else if (has_method() && method()->name() != 0 &&
1146                method()->intrinsic_id() == vmIntrinsics::_forEachRemaining) {
1147       set_do_vector_loop(true);
1148     }
1149   }
1150   set_use_cmove(UseCMoveUnconditionally /* || do_vector_loop()*/); //TODO: consider do_vector_loop() mandate use_cmove unconditionally
1151   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());})
1152 
1153   set_age_code(has_method() && method()->profile_aging());
1154   set_rtm_state(NoRTM); // No RTM lock eliding by default
1155   _max_node_limit = _directive->MaxNodeLimitOption;
1156 
1157 #if INCLUDE_RTM_OPT
1158   if (UseRTMLocking && has_method() && (method()->method_data_or_null() != NULL)) {
1159     int rtm_state = method()->method_data()->rtm_state();
1160     if (method_has_option("NoRTMLockEliding") || ((rtm_state & NoRTM) != 0)) {
1161       // Don't generate RTM lock eliding code.
1162       set_rtm_state(NoRTM);
1163     } else if (method_has_option("UseRTMLockEliding") || ((rtm_state & UseRTM) != 0) || !UseRTMDeopt) {
1164       // Generate RTM lock eliding code without abort ratio calculation code.
1165       set_rtm_state(UseRTM);
1166     } else if (UseRTMDeopt) {
1167       // Generate RTM lock eliding code and include abort ratio calculation
1168       // code if UseRTMDeopt is on.
1169       set_rtm_state(ProfileRTM);
1170     }
1171   }
1172 #endif
1173   if (debug_info()->recording_non_safepoints()) {
1174     set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
1175                         (comp_arena(), 8, 0, NULL));
1176     set_default_node_notes(Node_Notes::make(this));
1177   }
1178 
1179   // // -- Initialize types before each compile --
1180   // // Update cached type information
1181   // if( _method && _method->constants() )
1182   //   Type::update_loaded_types(_method, _method->constants());
1183 
1184   // Init alias_type map.
1185   if (!_do_escape_analysis && aliaslevel == 3)
1186     aliaslevel = 2;  // No unique types without escape analysis
1187   _AliasLevel = aliaslevel;
1188   const int grow_ats = 16;
1189   _max_alias_types = grow_ats;
1190   _alias_types   = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
1191   AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType,  grow_ats);
1192   Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
1193   {
1194     for (int i = 0; i < grow_ats; i++)  _alias_types[i] = &ats[i];
1195   }
1196   // Initialize the first few types.
1197   _alias_types[AliasIdxTop]->Init(AliasIdxTop, NULL);
1198   _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
1199   _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
1200   _num_alias_types = AliasIdxRaw+1;
1201   // Zero out the alias type cache.
1202   Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
1203   // A NULL adr_type hits in the cache right away.  Preload the right answer.
1204   probe_alias_cache(NULL)->_index = AliasIdxTop;
1205 
1206   _intrinsics = NULL;
1207   _macro_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1208   _predicate_opaqs = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1209   _expensive_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1210   _range_check_casts = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1211   _opaque4_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1212   register_library_intrinsics();
1213 }
1214 
1215 //---------------------------init_start----------------------------------------
1216 // Install the StartNode on this compile object.
1217 void Compile::init_start(StartNode* s) {
1218   if (failing())
1219     return; // already failing
1220   assert(s == start(), "");
1221 }
1222 
1223 /**
1224  * Return the 'StartNode'. We must not have a pending failure, since the ideal graph
1225  * can be in an inconsistent state, i.e., we can get segmentation faults when traversing
1226  * the ideal graph.
1227  */
1228 StartNode* Compile::start() const {
1229   assert (!failing(), "Must not have pending failure. Reason is: %s", failure_reason());
1230   for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
1231     Node* start = root()->fast_out(i);
1232     if (start->is_Start()) {
1233       return start->as_Start();
1234     }
1235   }
1236   fatal("Did not find Start node!");
1237   return NULL;
1238 }
1239 
1240 //-------------------------------immutable_memory-------------------------------------
1241 // Access immutable memory
1242 Node* Compile::immutable_memory() {
1243   if (_immutable_memory != NULL) {
1244     return _immutable_memory;
1245   }
1246   StartNode* s = start();
1247   for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
1248     Node *p = s->fast_out(i);
1249     if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
1250       _immutable_memory = p;
1251       return _immutable_memory;
1252     }
1253   }
1254   ShouldNotReachHere();
1255   return NULL;
1256 }
1257 
1258 //----------------------set_cached_top_node------------------------------------
1259 // Install the cached top node, and make sure Node::is_top works correctly.
1260 void Compile::set_cached_top_node(Node* tn) {
1261   if (tn != NULL)  verify_top(tn);
1262   Node* old_top = _top;
1263   _top = tn;
1264   // Calling Node::setup_is_top allows the nodes the chance to adjust
1265   // their _out arrays.
1266   if (_top != NULL)     _top->setup_is_top();
1267   if (old_top != NULL)  old_top->setup_is_top();
1268   assert(_top == NULL || top()->is_top(), "");
1269 }
1270 
1271 #ifdef ASSERT
1272 uint Compile::count_live_nodes_by_graph_walk() {
1273   Unique_Node_List useful(comp_arena());
1274   // Get useful node list by walking the graph.
1275   identify_useful_nodes(useful);
1276   return useful.size();
1277 }
1278 
1279 void Compile::print_missing_nodes() {
1280 
1281   // Return if CompileLog is NULL and PrintIdealNodeCount is false.
1282   if ((_log == NULL) && (! PrintIdealNodeCount)) {
1283     return;
1284   }
1285 
1286   // This is an expensive function. It is executed only when the user
1287   // specifies VerifyIdealNodeCount option or otherwise knows the
1288   // additional work that needs to be done to identify reachable nodes
1289   // by walking the flow graph and find the missing ones using
1290   // _dead_node_list.
1291 
1292   Unique_Node_List useful(comp_arena());
1293   // Get useful node list by walking the graph.
1294   identify_useful_nodes(useful);
1295 
1296   uint l_nodes = C->live_nodes();
1297   uint l_nodes_by_walk = useful.size();
1298 
1299   if (l_nodes != l_nodes_by_walk) {
1300     if (_log != NULL) {
1301       _log->begin_head("mismatched_nodes count='%d'", abs((int) (l_nodes - l_nodes_by_walk)));
1302       _log->stamp();
1303       _log->end_head();
1304     }
1305     VectorSet& useful_member_set = useful.member_set();
1306     int last_idx = l_nodes_by_walk;
1307     for (int i = 0; i < last_idx; i++) {
1308       if (useful_member_set.test(i)) {
1309         if (_dead_node_list.test(i)) {
1310           if (_log != NULL) {
1311             _log->elem("mismatched_node_info node_idx='%d' type='both live and dead'", i);
1312           }
1313           if (PrintIdealNodeCount) {
1314             // Print the log message to tty
1315               tty->print_cr("mismatched_node idx='%d' both live and dead'", i);
1316               useful.at(i)->dump();
1317           }
1318         }
1319       }
1320       else if (! _dead_node_list.test(i)) {
1321         if (_log != NULL) {
1322           _log->elem("mismatched_node_info node_idx='%d' type='neither live nor dead'", i);
1323         }
1324         if (PrintIdealNodeCount) {
1325           // Print the log message to tty
1326           tty->print_cr("mismatched_node idx='%d' type='neither live nor dead'", i);
1327         }
1328       }
1329     }
1330     if (_log != NULL) {
1331       _log->tail("mismatched_nodes");
1332     }
1333   }
1334 }
1335 void Compile::record_modified_node(Node* n) {
1336   if (_modified_nodes != NULL && !_inlining_incrementally &&
1337       n->outcnt() != 0 && !n->is_Con()) {
1338     _modified_nodes->push(n);
1339   }
1340 }
1341 
1342 void Compile::remove_modified_node(Node* n) {
1343   if (_modified_nodes != NULL) {
1344     _modified_nodes->remove(n);
1345   }
1346 }
1347 #endif
1348 
1349 #ifndef PRODUCT
1350 void Compile::verify_top(Node* tn) const {
1351   if (tn != NULL) {
1352     assert(tn->is_Con(), "top node must be a constant");
1353     assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
1354     assert(tn->in(0) != NULL, "must have live top node");
1355   }
1356 }
1357 #endif
1358 
1359 
1360 ///-------------------Managing Per-Node Debug & Profile Info-------------------
1361 
1362 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
1363   guarantee(arr != NULL, "");
1364   int num_blocks = arr->length();
1365   if (grow_by < num_blocks)  grow_by = num_blocks;
1366   int num_notes = grow_by * _node_notes_block_size;
1367   Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
1368   Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
1369   while (num_notes > 0) {
1370     arr->append(notes);
1371     notes     += _node_notes_block_size;
1372     num_notes -= _node_notes_block_size;
1373   }
1374   assert(num_notes == 0, "exact multiple, please");
1375 }
1376 
1377 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
1378   if (source == NULL || dest == NULL)  return false;
1379 
1380   if (dest->is_Con())
1381     return false;               // Do not push debug info onto constants.
1382 
1383 #ifdef ASSERT
1384   // Leave a bread crumb trail pointing to the original node:
1385   if (dest != NULL && dest != source && dest->debug_orig() == NULL) {
1386     dest->set_debug_orig(source);
1387   }
1388 #endif
1389 
1390   if (node_note_array() == NULL)
1391     return false;               // Not collecting any notes now.
1392 
1393   // This is a copy onto a pre-existing node, which may already have notes.
1394   // If both nodes have notes, do not overwrite any pre-existing notes.
1395   Node_Notes* source_notes = node_notes_at(source->_idx);
1396   if (source_notes == NULL || source_notes->is_clear())  return false;
1397   Node_Notes* dest_notes   = node_notes_at(dest->_idx);
1398   if (dest_notes == NULL || dest_notes->is_clear()) {
1399     return set_node_notes_at(dest->_idx, source_notes);
1400   }
1401 
1402   Node_Notes merged_notes = (*source_notes);
1403   // The order of operations here ensures that dest notes will win...
1404   merged_notes.update_from(dest_notes);
1405   return set_node_notes_at(dest->_idx, &merged_notes);
1406 }
1407 
1408 
1409 //--------------------------allow_range_check_smearing-------------------------
1410 // Gating condition for coalescing similar range checks.
1411 // Sometimes we try 'speculatively' replacing a series of a range checks by a
1412 // single covering check that is at least as strong as any of them.
1413 // If the optimization succeeds, the simplified (strengthened) range check
1414 // will always succeed.  If it fails, we will deopt, and then give up
1415 // on the optimization.
1416 bool Compile::allow_range_check_smearing() const {
1417   // If this method has already thrown a range-check,
1418   // assume it was because we already tried range smearing
1419   // and it failed.
1420   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
1421   return !already_trapped;
1422 }
1423 
1424 
1425 //------------------------------flatten_alias_type-----------------------------
1426 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
1427   int offset = tj->offset();
1428   TypePtr::PTR ptr = tj->ptr();
1429 
1430   // Known instance (scalarizable allocation) alias only with itself.
1431   bool is_known_inst = tj->isa_oopptr() != NULL &&
1432                        tj->is_oopptr()->is_known_instance();
1433 
1434   // Process weird unsafe references.
1435   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
1436     assert(InlineUnsafeOps, "indeterminate pointers come only from unsafe ops");
1437     assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
1438     tj = TypeOopPtr::BOTTOM;
1439     ptr = tj->ptr();
1440     offset = tj->offset();
1441   }
1442 
1443   // Array pointers need some flattening
1444   const TypeAryPtr *ta = tj->isa_aryptr();
1445   if (ta && ta->is_stable()) {
1446     // Erase stability property for alias analysis.
1447     tj = ta = ta->cast_to_stable(false);
1448   }
1449   if( ta && is_known_inst ) {
1450     if ( offset != Type::OffsetBot &&
1451          offset > arrayOopDesc::length_offset_in_bytes() ) {
1452       offset = Type::OffsetBot; // Flatten constant access into array body only
1453       tj = ta = TypeAryPtr::make(ptr, ta->ary(), ta->klass(), true, offset, ta->instance_id());
1454     }
1455   } else if( ta && _AliasLevel >= 2 ) {
1456     // For arrays indexed by constant indices, we flatten the alias
1457     // space to include all of the array body.  Only the header, klass
1458     // and array length can be accessed un-aliased.
1459     if( offset != Type::OffsetBot ) {
1460       if( ta->const_oop() ) { // MethodData* or Method*
1461         offset = Type::OffsetBot;   // Flatten constant access into array body
1462         tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),ta->ary(),ta->klass(),false,offset);
1463       } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
1464         // range is OK as-is.
1465         tj = ta = TypeAryPtr::RANGE;
1466       } else if( offset == oopDesc::klass_offset_in_bytes() ) {
1467         tj = TypeInstPtr::KLASS; // all klass loads look alike
1468         ta = TypeAryPtr::RANGE; // generic ignored junk
1469         ptr = TypePtr::BotPTR;
1470       } else if( offset == oopDesc::mark_offset_in_bytes() ) {
1471         tj = TypeInstPtr::MARK;
1472         ta = TypeAryPtr::RANGE; // generic ignored junk
1473         ptr = TypePtr::BotPTR;
1474       } else if (BarrierSet::barrier_set()->barrier_set_c2()->flatten_gc_alias_type(tj)) {
1475         ta = tj->isa_aryptr();
1476       } else {                  // Random constant offset into array body
1477         offset = Type::OffsetBot;   // Flatten constant access into array body
1478         tj = ta = TypeAryPtr::make(ptr,ta->ary(),ta->klass(),false,offset);
1479       }
1480     }
1481     // Arrays of fixed size alias with arrays of unknown size.
1482     if (ta->size() != TypeInt::POS) {
1483       const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
1484       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,ta->klass(),false,offset);
1485     }
1486     // Arrays of known objects become arrays of unknown objects.
1487     if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
1488       const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
1489       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1490     }
1491     if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
1492       const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
1493       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1494     }
1495     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
1496     // cannot be distinguished by bytecode alone.
1497     if (ta->elem() == TypeInt::BOOL) {
1498       const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
1499       ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
1500       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,offset);
1501     }
1502     // During the 2nd round of IterGVN, NotNull castings are removed.
1503     // Make sure the Bottom and NotNull variants alias the same.
1504     // Also, make sure exact and non-exact variants alias the same.
1505     if (ptr == TypePtr::NotNull || ta->klass_is_exact() || ta->speculative() != NULL) {
1506       tj = ta = TypeAryPtr::make(TypePtr::BotPTR,ta->ary(),ta->klass(),false,offset);
1507     }
1508   }
1509 
1510   // Oop pointers need some flattening
1511   const TypeInstPtr *to = tj->isa_instptr();
1512   if( to && _AliasLevel >= 2 && to != TypeOopPtr::BOTTOM ) {
1513     ciInstanceKlass *k = to->klass()->as_instance_klass();
1514     if( ptr == TypePtr::Constant ) {
1515       if (to->klass() != ciEnv::current()->Class_klass() ||
1516           offset < k->size_helper() * wordSize) {
1517         // No constant oop pointers (such as Strings); they alias with
1518         // unknown strings.
1519         assert(!is_known_inst, "not scalarizable allocation");
1520         tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1521       }
1522     } else if( is_known_inst ) {
1523       tj = to; // Keep NotNull and klass_is_exact for instance type
1524     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
1525       // During the 2nd round of IterGVN, NotNull castings are removed.
1526       // Make sure the Bottom and NotNull variants alias the same.
1527       // Also, make sure exact and non-exact variants alias the same.
1528       tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1529     }
1530     if (to->speculative() != NULL) {
1531       tj = to = TypeInstPtr::make(to->ptr(),to->klass(),to->klass_is_exact(),to->const_oop(),to->offset(), to->instance_id());
1532     }
1533     // Canonicalize the holder of this field
1534     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
1535       // First handle header references such as a LoadKlassNode, even if the
1536       // object's klass is unloaded at compile time (4965979).
1537       if (!is_known_inst) { // Do it only for non-instance types
1538         tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, NULL, offset);
1539       }
1540     } else if (BarrierSet::barrier_set()->barrier_set_c2()->flatten_gc_alias_type(tj)) {
1541       to = tj->is_instptr();
1542     } else if (offset < 0 || offset >= k->size_helper() * wordSize) {
1543       // Static fields are in the space above the normal instance
1544       // fields in the java.lang.Class instance.
1545       if (to->klass() != ciEnv::current()->Class_klass()) {
1546         to = NULL;
1547         tj = TypeOopPtr::BOTTOM;
1548         offset = tj->offset();
1549       }
1550     } else {
1551       ciInstanceKlass *canonical_holder = k->get_canonical_holder(offset);
1552       if (!k->equals(canonical_holder) || tj->offset() != offset) {
1553         if( is_known_inst ) {
1554           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, true, NULL, offset, to->instance_id());
1555         } else {
1556           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, false, NULL, offset);
1557         }
1558       }
1559     }
1560   }
1561 
1562   // Klass pointers to object array klasses need some flattening
1563   const TypeKlassPtr *tk = tj->isa_klassptr();
1564   if( tk ) {
1565     // If we are referencing a field within a Klass, we need
1566     // to assume the worst case of an Object.  Both exact and
1567     // inexact types must flatten to the same alias class so
1568     // use NotNull as the PTR.
1569     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
1570 
1571       tj = tk = TypeKlassPtr::make(TypePtr::NotNull,
1572                                    TypeKlassPtr::OBJECT->klass(),
1573                                    offset);
1574     }
1575 
1576     ciKlass* klass = tk->klass();
1577     if( klass->is_obj_array_klass() ) {
1578       ciKlass* k = TypeAryPtr::OOPS->klass();
1579       if( !k || !k->is_loaded() )                  // Only fails for some -Xcomp runs
1580         k = TypeInstPtr::BOTTOM->klass();
1581       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, k, offset );
1582     }
1583 
1584     // Check for precise loads from the primary supertype array and force them
1585     // to the supertype cache alias index.  Check for generic array loads from
1586     // the primary supertype array and also force them to the supertype cache
1587     // alias index.  Since the same load can reach both, we need to merge
1588     // these 2 disparate memories into the same alias class.  Since the
1589     // primary supertype array is read-only, there's no chance of confusion
1590     // where we bypass an array load and an array store.
1591     int primary_supers_offset = in_bytes(Klass::primary_supers_offset());
1592     if (offset == Type::OffsetBot ||
1593         (offset >= primary_supers_offset &&
1594          offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
1595         offset == (int)in_bytes(Klass::secondary_super_cache_offset())) {
1596       offset = in_bytes(Klass::secondary_super_cache_offset());
1597       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, tk->klass(), offset );
1598     }
1599   }
1600 
1601   // Flatten all Raw pointers together.
1602   if (tj->base() == Type::RawPtr)
1603     tj = TypeRawPtr::BOTTOM;
1604 
1605   if (tj->base() == Type::AnyPtr)
1606     tj = TypePtr::BOTTOM;      // An error, which the caller must check for.
1607 
1608   // Flatten all to bottom for now
1609   switch( _AliasLevel ) {
1610   case 0:
1611     tj = TypePtr::BOTTOM;
1612     break;
1613   case 1:                       // Flatten to: oop, static, field or array
1614     switch (tj->base()) {
1615     //case Type::AryPtr: tj = TypeAryPtr::RANGE;    break;
1616     case Type::RawPtr:   tj = TypeRawPtr::BOTTOM;   break;
1617     case Type::AryPtr:   // do not distinguish arrays at all
1618     case Type::InstPtr:  tj = TypeInstPtr::BOTTOM;  break;
1619     case Type::KlassPtr: tj = TypeKlassPtr::OBJECT; break;
1620     case Type::AnyPtr:   tj = TypePtr::BOTTOM;      break;  // caller checks it
1621     default: ShouldNotReachHere();
1622     }
1623     break;
1624   case 2:                       // No collapsing at level 2; keep all splits
1625   case 3:                       // No collapsing at level 3; keep all splits
1626     break;
1627   default:
1628     Unimplemented();
1629   }
1630 
1631   offset = tj->offset();
1632   assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
1633 
1634   assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
1635           (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
1636           (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
1637           (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
1638           (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1639           (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1640           (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1641           (BarrierSet::barrier_set()->barrier_set_c2()->verify_gc_alias_type(tj, offset)),
1642           "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
1643   assert( tj->ptr() != TypePtr::TopPTR &&
1644           tj->ptr() != TypePtr::AnyNull &&
1645           tj->ptr() != TypePtr::Null, "No imprecise addresses" );
1646 //    assert( tj->ptr() != TypePtr::Constant ||
1647 //            tj->base() == Type::RawPtr ||
1648 //            tj->base() == Type::KlassPtr, "No constant oop addresses" );
1649 
1650   return tj;
1651 }
1652 
1653 void Compile::AliasType::Init(int i, const TypePtr* at) {
1654   _index = i;
1655   _adr_type = at;
1656   _field = NULL;
1657   _element = NULL;
1658   _is_rewritable = true; // default
1659   const TypeOopPtr *atoop = (at != NULL) ? at->isa_oopptr() : NULL;
1660   if (atoop != NULL && atoop->is_known_instance()) {
1661     const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
1662     _general_index = Compile::current()->get_alias_index(gt);
1663   } else {
1664     _general_index = 0;
1665   }
1666 }
1667 
1668 BasicType Compile::AliasType::basic_type() const {
1669   if (element() != NULL) {
1670     const Type* element = adr_type()->is_aryptr()->elem();
1671     return element->isa_narrowoop() ? T_OBJECT : element->array_element_basic_type();
1672   } if (field() != NULL) {
1673     return field()->layout_type();
1674   } else {
1675     return T_ILLEGAL; // unknown
1676   }
1677 }
1678 
1679 //---------------------------------print_on------------------------------------
1680 #ifndef PRODUCT
1681 void Compile::AliasType::print_on(outputStream* st) {
1682   if (index() < 10)
1683         st->print("@ <%d> ", index());
1684   else  st->print("@ <%d>",  index());
1685   st->print(is_rewritable() ? "   " : " RO");
1686   int offset = adr_type()->offset();
1687   if (offset == Type::OffsetBot)
1688         st->print(" +any");
1689   else  st->print(" +%-3d", offset);
1690   st->print(" in ");
1691   adr_type()->dump_on(st);
1692   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
1693   if (field() != NULL && tjp) {
1694     if (tjp->klass()  != field()->holder() ||
1695         tjp->offset() != field()->offset_in_bytes()) {
1696       st->print(" != ");
1697       field()->print();
1698       st->print(" ***");
1699     }
1700   }
1701 }
1702 
1703 void print_alias_types() {
1704   Compile* C = Compile::current();
1705   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
1706   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
1707     C->alias_type(idx)->print_on(tty);
1708     tty->cr();
1709   }
1710 }
1711 #endif
1712 
1713 
1714 //----------------------------probe_alias_cache--------------------------------
1715 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
1716   intptr_t key = (intptr_t) adr_type;
1717   key ^= key >> logAliasCacheSize;
1718   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
1719 }
1720 
1721 
1722 //-----------------------------grow_alias_types--------------------------------
1723 void Compile::grow_alias_types() {
1724   const int old_ats  = _max_alias_types; // how many before?
1725   const int new_ats  = old_ats;          // how many more?
1726   const int grow_ats = old_ats+new_ats;  // how many now?
1727   _max_alias_types = grow_ats;
1728   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
1729   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
1730   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
1731   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
1732 }
1733 
1734 
1735 //--------------------------------find_alias_type------------------------------
1736 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field) {
1737   if (_AliasLevel == 0)
1738     return alias_type(AliasIdxBot);
1739 
1740   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1741   if (ace->_adr_type == adr_type) {
1742     return alias_type(ace->_index);
1743   }
1744 
1745   // Handle special cases.
1746   if (adr_type == NULL)             return alias_type(AliasIdxTop);
1747   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
1748 
1749   // Do it the slow way.
1750   const TypePtr* flat = flatten_alias_type(adr_type);
1751 
1752 #ifdef ASSERT
1753   {
1754     ResourceMark rm;
1755     assert(flat == flatten_alias_type(flat), "not idempotent: adr_type = %s; flat = %s => %s",
1756            Type::str(adr_type), Type::str(flat), Type::str(flatten_alias_type(flat)));
1757     assert(flat != TypePtr::BOTTOM, "cannot alias-analyze an untyped ptr: adr_type = %s",
1758            Type::str(adr_type));
1759     if (flat->isa_oopptr() && !flat->isa_klassptr()) {
1760       const TypeOopPtr* foop = flat->is_oopptr();
1761       // Scalarizable allocations have exact klass always.
1762       bool exact = !foop->klass_is_exact() || foop->is_known_instance();
1763       const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
1764       assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type: foop = %s; xoop = %s",
1765              Type::str(foop), Type::str(xoop));
1766     }
1767   }
1768 #endif
1769 
1770   int idx = AliasIdxTop;
1771   for (int i = 0; i < num_alias_types(); i++) {
1772     if (alias_type(i)->adr_type() == flat) {
1773       idx = i;
1774       break;
1775     }
1776   }
1777 
1778   if (idx == AliasIdxTop) {
1779     if (no_create)  return NULL;
1780     // Grow the array if necessary.
1781     if (_num_alias_types == _max_alias_types)  grow_alias_types();
1782     // Add a new alias type.
1783     idx = _num_alias_types++;
1784     _alias_types[idx]->Init(idx, flat);
1785     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
1786     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
1787     if (flat->isa_instptr()) {
1788       if (flat->offset() == java_lang_Class::klass_offset_in_bytes()
1789           && flat->is_instptr()->klass() == env()->Class_klass())
1790         alias_type(idx)->set_rewritable(false);
1791     }
1792     if (flat->isa_aryptr()) {
1793 #ifdef ASSERT
1794       const int header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1795       // (T_BYTE has the weakest alignment and size restrictions...)
1796       assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
1797 #endif
1798       if (flat->offset() == TypePtr::OffsetBot) {
1799         alias_type(idx)->set_element(flat->is_aryptr()->elem());
1800       }
1801     }
1802     if (flat->isa_klassptr()) {
1803       if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
1804         alias_type(idx)->set_rewritable(false);
1805       if (flat->offset() == in_bytes(Klass::modifier_flags_offset()))
1806         alias_type(idx)->set_rewritable(false);
1807       if (flat->offset() == in_bytes(Klass::access_flags_offset()))
1808         alias_type(idx)->set_rewritable(false);
1809       if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
1810         alias_type(idx)->set_rewritable(false);
1811     }
1812     // %%% (We would like to finalize JavaThread::threadObj_offset(),
1813     // but the base pointer type is not distinctive enough to identify
1814     // references into JavaThread.)
1815 
1816     // Check for final fields.
1817     const TypeInstPtr* tinst = flat->isa_instptr();
1818     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
1819       ciField* field;
1820       if (tinst->const_oop() != NULL &&
1821           tinst->klass() == ciEnv::current()->Class_klass() &&
1822           tinst->offset() >= (tinst->klass()->as_instance_klass()->size_helper() * wordSize)) {
1823         // static field
1824         ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
1825         field = k->get_field_by_offset(tinst->offset(), true);
1826       } else {
1827         ciInstanceKlass *k = tinst->klass()->as_instance_klass();
1828         field = k->get_field_by_offset(tinst->offset(), false);
1829       }
1830       assert(field == NULL ||
1831              original_field == NULL ||
1832              (field->holder() == original_field->holder() &&
1833               field->offset() == original_field->offset() &&
1834               field->is_static() == original_field->is_static()), "wrong field?");
1835       // Set field() and is_rewritable() attributes.
1836       if (field != NULL)  alias_type(idx)->set_field(field);
1837     }
1838   }
1839 
1840   // Fill the cache for next time.
1841   ace->_adr_type = adr_type;
1842   ace->_index    = idx;
1843   assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
1844 
1845   // Might as well try to fill the cache for the flattened version, too.
1846   AliasCacheEntry* face = probe_alias_cache(flat);
1847   if (face->_adr_type == NULL) {
1848     face->_adr_type = flat;
1849     face->_index    = idx;
1850     assert(alias_type(flat) == alias_type(idx), "flat type must work too");
1851   }
1852 
1853   return alias_type(idx);
1854 }
1855 
1856 
1857 Compile::AliasType* Compile::alias_type(ciField* field) {
1858   const TypeOopPtr* t;
1859   if (field->is_static())
1860     t = TypeInstPtr::make(field->holder()->java_mirror());
1861   else
1862     t = TypeOopPtr::make_from_klass_raw(field->holder());
1863   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);
1864   assert((field->is_final() || field->is_stable()) == !atp->is_rewritable(), "must get the rewritable bits correct");
1865   return atp;
1866 }
1867 
1868 
1869 //------------------------------have_alias_type--------------------------------
1870 bool Compile::have_alias_type(const TypePtr* adr_type) {
1871   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1872   if (ace->_adr_type == adr_type) {
1873     return true;
1874   }
1875 
1876   // Handle special cases.
1877   if (adr_type == NULL)             return true;
1878   if (adr_type == TypePtr::BOTTOM)  return true;
1879 
1880   return find_alias_type(adr_type, true, NULL) != NULL;
1881 }
1882 
1883 //-----------------------------must_alias--------------------------------------
1884 // True if all values of the given address type are in the given alias category.
1885 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
1886   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1887   if (adr_type == NULL)                 return true;  // NULL serves as TypePtr::TOP
1888   if (alias_idx == AliasIdxTop)         return false; // the empty category
1889   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
1890 
1891   // the only remaining possible overlap is identity
1892   int adr_idx = get_alias_index(adr_type);
1893   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1894   assert(adr_idx == alias_idx ||
1895          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
1896           && adr_type                       != TypeOopPtr::BOTTOM),
1897          "should not be testing for overlap with an unsafe pointer");
1898   return adr_idx == alias_idx;
1899 }
1900 
1901 //------------------------------can_alias--------------------------------------
1902 // True if any values of the given address type are in the given alias category.
1903 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
1904   if (alias_idx == AliasIdxTop)         return false; // the empty category
1905   if (adr_type == NULL)                 return false; // NULL serves as TypePtr::TOP
1906   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1907   if (adr_type->base() == Type::AnyPtr) return true;  // TypePtr::BOTTOM or its twins
1908 
1909   // the only remaining possible overlap is identity
1910   int adr_idx = get_alias_index(adr_type);
1911   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1912   return adr_idx == alias_idx;
1913 }
1914 
1915 
1916 
1917 //---------------------------pop_warm_call-------------------------------------
1918 WarmCallInfo* Compile::pop_warm_call() {
1919   WarmCallInfo* wci = _warm_calls;
1920   if (wci != NULL)  _warm_calls = wci->remove_from(wci);
1921   return wci;
1922 }
1923 
1924 //----------------------------Inline_Warm--------------------------------------
1925 int Compile::Inline_Warm() {
1926   // If there is room, try to inline some more warm call sites.
1927   // %%% Do a graph index compaction pass when we think we're out of space?
1928   if (!InlineWarmCalls)  return 0;
1929 
1930   int calls_made_hot = 0;
1931   int room_to_grow   = NodeCountInliningCutoff - unique();
1932   int amount_to_grow = MIN2(room_to_grow, (int)NodeCountInliningStep);
1933   int amount_grown   = 0;
1934   WarmCallInfo* call;
1935   while (amount_to_grow > 0 && (call = pop_warm_call()) != NULL) {
1936     int est_size = (int)call->size();
1937     if (est_size > (room_to_grow - amount_grown)) {
1938       // This one won't fit anyway.  Get rid of it.
1939       call->make_cold();
1940       continue;
1941     }
1942     call->make_hot();
1943     calls_made_hot++;
1944     amount_grown   += est_size;
1945     amount_to_grow -= est_size;
1946   }
1947 
1948   if (calls_made_hot > 0)  set_major_progress();
1949   return calls_made_hot;
1950 }
1951 
1952 
1953 //----------------------------Finish_Warm--------------------------------------
1954 void Compile::Finish_Warm() {
1955   if (!InlineWarmCalls)  return;
1956   if (failing())  return;
1957   if (warm_calls() == NULL)  return;
1958 
1959   // Clean up loose ends, if we are out of space for inlining.
1960   WarmCallInfo* call;
1961   while ((call = pop_warm_call()) != NULL) {
1962     call->make_cold();
1963   }
1964 }
1965 
1966 //---------------------cleanup_loop_predicates-----------------------
1967 // Remove the opaque nodes that protect the predicates so that all unused
1968 // checks and uncommon_traps will be eliminated from the ideal graph
1969 void Compile::cleanup_loop_predicates(PhaseIterGVN &igvn) {
1970   if (predicate_count()==0) return;
1971   for (int i = predicate_count(); i > 0; i--) {
1972     Node * n = predicate_opaque1_node(i-1);
1973     assert(n->Opcode() == Op_Opaque1, "must be");
1974     igvn.replace_node(n, n->in(1));
1975   }
1976   assert(predicate_count()==0, "should be clean!");
1977 }
1978 
1979 void Compile::add_range_check_cast(Node* n) {
1980   assert(n->isa_CastII()->has_range_check(), "CastII should have range check dependency");
1981   assert(!_range_check_casts->contains(n), "duplicate entry in range check casts");
1982   _range_check_casts->append(n);
1983 }
1984 
1985 // Remove all range check dependent CastIINodes.
1986 void Compile::remove_range_check_casts(PhaseIterGVN &igvn) {
1987   for (int i = range_check_cast_count(); i > 0; i--) {
1988     Node* cast = range_check_cast_node(i-1);
1989     assert(cast->isa_CastII()->has_range_check(), "CastII should have range check dependency");
1990     igvn.replace_node(cast, cast->in(1));
1991   }
1992   assert(range_check_cast_count() == 0, "should be empty");
1993 }
1994 
1995 void Compile::add_opaque4_node(Node* n) {
1996   assert(n->Opcode() == Op_Opaque4, "Opaque4 only");
1997   assert(!_opaque4_nodes->contains(n), "duplicate entry in Opaque4 list");
1998   _opaque4_nodes->append(n);
1999 }
2000 
2001 // Remove all Opaque4 nodes.
2002 void Compile::remove_opaque4_nodes(PhaseIterGVN &igvn) {
2003   for (int i = opaque4_count(); i > 0; i--) {
2004     Node* opaq = opaque4_node(i-1);
2005     assert(opaq->Opcode() == Op_Opaque4, "Opaque4 only");
2006     igvn.replace_node(opaq, opaq->in(2));
2007   }
2008   assert(opaque4_count() == 0, "should be empty");
2009 }
2010 
2011 // StringOpts and late inlining of string methods
2012 void Compile::inline_string_calls(bool parse_time) {
2013   {
2014     // remove useless nodes to make the usage analysis simpler
2015     ResourceMark rm;
2016     PhaseRemoveUseless pru(initial_gvn(), for_igvn());
2017   }
2018 
2019   {
2020     ResourceMark rm;
2021     print_method(PHASE_BEFORE_STRINGOPTS, 3);
2022     PhaseStringOpts pso(initial_gvn(), for_igvn());
2023     print_method(PHASE_AFTER_STRINGOPTS, 3);
2024   }
2025 
2026   // now inline anything that we skipped the first time around
2027   if (!parse_time) {
2028     _late_inlines_pos = _late_inlines.length();
2029   }
2030 
2031   while (_string_late_inlines.length() > 0) {
2032     CallGenerator* cg = _string_late_inlines.pop();
2033     cg->do_late_inline();
2034     if (failing())  return;
2035   }
2036   _string_late_inlines.trunc_to(0);
2037 }
2038 
2039 // Late inlining of boxing methods
2040 void Compile::inline_boxing_calls(PhaseIterGVN& igvn) {
2041   if (_boxing_late_inlines.length() > 0) {
2042     assert(has_boxed_value(), "inconsistent");
2043 
2044     PhaseGVN* gvn = initial_gvn();
2045     set_inlining_incrementally(true);
2046 
2047     assert( igvn._worklist.size() == 0, "should be done with igvn" );
2048     for_igvn()->clear();
2049     gvn->replace_with(&igvn);
2050 
2051     _late_inlines_pos = _late_inlines.length();
2052 
2053     while (_boxing_late_inlines.length() > 0) {
2054       CallGenerator* cg = _boxing_late_inlines.pop();
2055       cg->do_late_inline();
2056       if (failing())  return;
2057     }
2058     _boxing_late_inlines.trunc_to(0);
2059 
2060     inline_incrementally_cleanup(igvn);
2061 
2062     set_inlining_incrementally(false);
2063   }
2064 }
2065 
2066 bool Compile::inline_incrementally_one() {
2067   assert(IncrementalInline, "incremental inlining should be on");
2068 
2069   TracePhase tp("incrementalInline_inline", &timers[_t_incrInline_inline]);
2070   set_inlining_progress(false);
2071   set_do_cleanup(false);
2072   int i = 0;
2073   for (; i <_late_inlines.length() && !inlining_progress(); i++) {
2074     CallGenerator* cg = _late_inlines.at(i);
2075     _late_inlines_pos = i+1;
2076     cg->do_late_inline();
2077     if (failing())  return false;
2078   }
2079   int j = 0;
2080   for (; i < _late_inlines.length(); i++, j++) {
2081     _late_inlines.at_put(j, _late_inlines.at(i));
2082   }
2083   _late_inlines.trunc_to(j);
2084   assert(inlining_progress() || _late_inlines.length() == 0, "");
2085 
2086   bool needs_cleanup = do_cleanup() || over_inlining_cutoff();
2087 
2088   set_inlining_progress(false);
2089   set_do_cleanup(false);
2090   return (_late_inlines.length() > 0) && !needs_cleanup;
2091 }
2092 
2093 void Compile::inline_incrementally_cleanup(PhaseIterGVN& igvn) {
2094   {
2095     TracePhase tp("incrementalInline_pru", &timers[_t_incrInline_pru]);
2096     ResourceMark rm;
2097     PhaseRemoveUseless pru(initial_gvn(), for_igvn());
2098   }
2099   {
2100     TracePhase tp("incrementalInline_igvn", &timers[_t_incrInline_igvn]);
2101     igvn = PhaseIterGVN(initial_gvn());
2102     igvn.optimize();
2103   }
2104 }
2105 
2106 // Perform incremental inlining until bound on number of live nodes is reached
2107 void Compile::inline_incrementally(PhaseIterGVN& igvn) {
2108   TracePhase tp("incrementalInline", &timers[_t_incrInline]);
2109 
2110   set_inlining_incrementally(true);
2111   uint low_live_nodes = 0;
2112 
2113   while (_late_inlines.length() > 0) {
2114     if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2115       if (low_live_nodes < (uint)LiveNodeCountInliningCutoff * 8 / 10) {
2116         TracePhase tp("incrementalInline_ideal", &timers[_t_incrInline_ideal]);
2117         // PhaseIdealLoop is expensive so we only try it once we are
2118         // out of live nodes and we only try it again if the previous
2119         // helped got the number of nodes down significantly
2120         PhaseIdealLoop::optimize(igvn, LoopOptsNone);
2121         if (failing())  return;
2122         low_live_nodes = live_nodes();
2123         _major_progress = true;
2124       }
2125 
2126       if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2127         break; // finish
2128       }
2129     }
2130 
2131     for_igvn()->clear();
2132     initial_gvn()->replace_with(&igvn);
2133 
2134     while (inline_incrementally_one()) {
2135       assert(!failing(), "inconsistent");
2136     }
2137 
2138     if (failing())  return;
2139 
2140     inline_incrementally_cleanup(igvn);
2141 
2142     if (failing())  return;
2143   }
2144   assert( igvn._worklist.size() == 0, "should be done with igvn" );
2145 
2146   if (_string_late_inlines.length() > 0) {
2147     assert(has_stringbuilder(), "inconsistent");
2148     for_igvn()->clear();
2149     initial_gvn()->replace_with(&igvn);
2150 
2151     inline_string_calls(false);
2152 
2153     if (failing())  return;
2154 
2155     inline_incrementally_cleanup(igvn);
2156   }
2157 
2158   set_inlining_incrementally(false);
2159 }
2160 
2161 
2162 bool Compile::optimize_loops(PhaseIterGVN& igvn, LoopOptsMode mode) {
2163   if(_loop_opts_cnt > 0) {
2164     debug_only( int cnt = 0; );
2165     while(major_progress() && (_loop_opts_cnt > 0)) {
2166       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2167       assert( cnt++ < 40, "infinite cycle in loop optimization" );
2168       PhaseIdealLoop::optimize(igvn, mode);
2169       _loop_opts_cnt--;
2170       if (failing())  return false;
2171       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
2172     }
2173   }
2174   return true;
2175 }
2176 
2177 // Remove edges from "root" to each SafePoint at a backward branch.
2178 // They were inserted during parsing (see add_safepoint()) to make
2179 // infinite loops without calls or exceptions visible to root, i.e.,
2180 // useful.
2181 void Compile::remove_root_to_sfpts_edges(PhaseIterGVN& igvn) {
2182   Node *r = root();
2183   if (r != NULL) {
2184     for (uint i = r->req(); i < r->len(); ++i) {
2185       Node *n = r->in(i);
2186       if (n != NULL && n->is_SafePoint()) {
2187         r->rm_prec(i);
2188         if (n->outcnt() == 0) {
2189           igvn.remove_dead_node(n);
2190         }
2191         --i;
2192       }
2193     }
2194   }
2195 }
2196 
2197 //------------------------------Optimize---------------------------------------
2198 // Given a graph, optimize it.
2199 void Compile::Optimize() {
2200   TracePhase tp("optimizer", &timers[_t_optimizer]);
2201 
2202 #ifndef PRODUCT
2203   if (_directive->BreakAtCompileOption) {
2204     BREAKPOINT;
2205   }
2206 
2207 #endif
2208 
2209 #ifdef ASSERT
2210   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
2211   bs->verify_gc_barriers(this, BarrierSetC2::BeforeOptimize);
2212 #endif
2213 
2214   ResourceMark rm;
2215 
2216   print_inlining_reinit();
2217 
2218   NOT_PRODUCT( verify_graph_edges(); )
2219 
2220   print_method(PHASE_AFTER_PARSING);
2221 
2222  {
2223   // Iterative Global Value Numbering, including ideal transforms
2224   // Initialize IterGVN with types and values from parse-time GVN
2225   PhaseIterGVN igvn(initial_gvn());
2226 #ifdef ASSERT
2227   _modified_nodes = new (comp_arena()) Unique_Node_List(comp_arena());
2228 #endif
2229   {
2230     TracePhase tp("iterGVN", &timers[_t_iterGVN]);
2231     igvn.optimize();
2232   }
2233 
2234   if (failing())  return;
2235 
2236   print_method(PHASE_ITER_GVN1, 2);
2237 
2238   inline_incrementally(igvn);
2239 
2240   print_method(PHASE_INCREMENTAL_INLINE, 2);
2241 
2242   if (failing())  return;
2243 
2244   if (eliminate_boxing()) {
2245     // Inline valueOf() methods now.
2246     inline_boxing_calls(igvn);
2247 
2248     if (AlwaysIncrementalInline) {
2249       inline_incrementally(igvn);
2250     }
2251 
2252     print_method(PHASE_INCREMENTAL_BOXING_INLINE, 2);
2253 
2254     if (failing())  return;
2255   }
2256 
2257   // Now that all inlining is over, cut edge from root to loop
2258   // safepoints
2259   remove_root_to_sfpts_edges(igvn);
2260 
2261   // Remove the speculative part of types and clean up the graph from
2262   // the extra CastPP nodes whose only purpose is to carry them. Do
2263   // that early so that optimizations are not disrupted by the extra
2264   // CastPP nodes.
2265   remove_speculative_types(igvn);
2266 
2267   // No more new expensive nodes will be added to the list from here
2268   // so keep only the actual candidates for optimizations.
2269   cleanup_expensive_nodes(igvn);
2270 
2271   if (!failing() && RenumberLiveNodes && live_nodes() + NodeLimitFudgeFactor < unique()) {
2272     Compile::TracePhase tp("", &timers[_t_renumberLive]);
2273     initial_gvn()->replace_with(&igvn);
2274     for_igvn()->clear();
2275     Unique_Node_List new_worklist(C->comp_arena());
2276     {
2277       ResourceMark rm;
2278       PhaseRenumberLive prl = PhaseRenumberLive(initial_gvn(), for_igvn(), &new_worklist);
2279     }
2280     set_for_igvn(&new_worklist);
2281     igvn = PhaseIterGVN(initial_gvn());
2282     igvn.optimize();
2283   }
2284 
2285   // Perform escape analysis
2286   if (_do_escape_analysis && ConnectionGraph::has_candidates(this)) {
2287     if (has_loops()) {
2288       // Cleanup graph (remove dead nodes).
2289       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2290       PhaseIdealLoop::optimize(igvn, LoopOptsNone);
2291       if (major_progress()) print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
2292       if (failing())  return;
2293     }
2294     ConnectionGraph::do_analysis(this, &igvn);
2295 
2296     if (failing())  return;
2297 
2298     // Optimize out fields loads from scalar replaceable allocations.
2299     igvn.optimize();
2300     print_method(PHASE_ITER_GVN_AFTER_EA, 2);
2301 
2302     if (failing())  return;
2303 
2304     if (congraph() != NULL && macro_count() > 0) {
2305       TracePhase tp("macroEliminate", &timers[_t_macroEliminate]);
2306       PhaseMacroExpand mexp(igvn);
2307       mexp.eliminate_macro_nodes();
2308       igvn.set_delay_transform(false);
2309 
2310       igvn.optimize();
2311       print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
2312 
2313       if (failing())  return;
2314     }
2315   }
2316 
2317   // Loop transforms on the ideal graph.  Range Check Elimination,
2318   // peeling, unrolling, etc.
2319 
2320   // Set loop opts counter
2321   if((_loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
2322     {
2323       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2324       PhaseIdealLoop::optimize(igvn, LoopOptsDefault);
2325       _loop_opts_cnt--;
2326       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP1, 2);
2327       if (failing())  return;
2328     }
2329     // Loop opts pass if partial peeling occurred in previous pass
2330     if(PartialPeelLoop && major_progress() && (_loop_opts_cnt > 0)) {
2331       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2332       PhaseIdealLoop::optimize(igvn, LoopOptsSkipSplitIf);
2333       _loop_opts_cnt--;
2334       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP2, 2);
2335       if (failing())  return;
2336     }
2337     // Loop opts pass for loop-unrolling before CCP
2338     if(major_progress() && (_loop_opts_cnt > 0)) {
2339       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2340       PhaseIdealLoop::optimize(igvn, LoopOptsSkipSplitIf);
2341       _loop_opts_cnt--;
2342       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP3, 2);
2343     }
2344     if (!failing()) {
2345       // Verify that last round of loop opts produced a valid graph
2346       TracePhase tp("idealLoopVerify", &timers[_t_idealLoopVerify]);
2347       PhaseIdealLoop::verify(igvn);
2348     }
2349   }
2350   if (failing())  return;
2351 
2352   // Conditional Constant Propagation;
2353   PhaseCCP ccp( &igvn );
2354   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
2355   {
2356     TracePhase tp("ccp", &timers[_t_ccp]);
2357     ccp.do_transform();
2358   }
2359   print_method(PHASE_CPP1, 2);
2360 
2361   assert( true, "Break here to ccp.dump_old2new_map()");
2362 
2363   // Iterative Global Value Numbering, including ideal transforms
2364   {
2365     TracePhase tp("iterGVN2", &timers[_t_iterGVN2]);
2366     igvn = ccp;
2367     igvn.optimize();
2368   }
2369 
2370   print_method(PHASE_ITER_GVN2, 2);
2371 
2372   if (failing())  return;
2373 
2374   // Loop transforms on the ideal graph.  Range Check Elimination,
2375   // peeling, unrolling, etc.
2376   if (!optimize_loops(igvn, LoopOptsDefault)) {
2377     return;
2378   }
2379 
2380 #if INCLUDE_ZGC
2381   if (UseZGC) {
2382     ZBarrierSetC2::find_dominating_barriers(igvn);
2383   }
2384 #endif
2385 
2386   if (failing())  return;
2387 
2388   // Ensure that major progress is now clear
2389   C->clear_major_progress();
2390 
2391   {
2392     // Verify that all previous optimizations produced a valid graph
2393     // at least to this point, even if no loop optimizations were done.
2394     TracePhase tp("idealLoopVerify", &timers[_t_idealLoopVerify]);
2395     PhaseIdealLoop::verify(igvn);
2396   }
2397 
2398   if (range_check_cast_count() > 0) {
2399     // No more loop optimizations. Remove all range check dependent CastIINodes.
2400     C->remove_range_check_casts(igvn);
2401     igvn.optimize();
2402   }
2403 
2404 #ifdef ASSERT
2405   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
2406   bs->verify_gc_barriers(this, BarrierSetC2::BeforeExpand);
2407 #endif
2408 
2409   {
2410     TracePhase tp("macroExpand", &timers[_t_macroExpand]);
2411     PhaseMacroExpand  mex(igvn);
2412     print_method(PHASE_BEFORE_MACRO_EXPANSION, 2);
2413     if (mex.expand_macro_nodes()) {
2414       assert(failing(), "must bail out w/ explicit message");
2415       return;
2416     }
2417   }
2418 
2419   {
2420     TracePhase tp("barrierExpand", &timers[_t_barrierExpand]);
2421     print_method(PHASE_BEFORE_BARRIER_EXPAND, 2);
2422     BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
2423     if (bs->expand_barriers(this, igvn)) {
2424       assert(failing(), "must bail out w/ explicit message");
2425       return;
2426     }
2427   }
2428 
2429   if (opaque4_count() > 0) {
2430     C->remove_opaque4_nodes(igvn);
2431     igvn.optimize();
2432   }
2433 
2434   DEBUG_ONLY( _modified_nodes = NULL; )
2435  } // (End scope of igvn; run destructor if necessary for asserts.)
2436 
2437  process_print_inlining();
2438  // A method with only infinite loops has no edges entering loops from root
2439  {
2440    TracePhase tp("graphReshape", &timers[_t_graphReshaping]);
2441    if (final_graph_reshaping()) {
2442      assert(failing(), "must bail out w/ explicit message");
2443      return;
2444    }
2445  }
2446 
2447  print_method(PHASE_OPTIMIZE_FINISHED, 2);
2448 }
2449 
2450 
2451 //------------------------------Code_Gen---------------------------------------
2452 // Given a graph, generate code for it
2453 void Compile::Code_Gen() {
2454   if (failing()) {
2455     return;
2456   }
2457 
2458   // Perform instruction selection.  You might think we could reclaim Matcher
2459   // memory PDQ, but actually the Matcher is used in generating spill code.
2460   // Internals of the Matcher (including some VectorSets) must remain live
2461   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
2462   // set a bit in reclaimed memory.
2463 
2464   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2465   // nodes.  Mapping is only valid at the root of each matched subtree.
2466   NOT_PRODUCT( verify_graph_edges(); )
2467 
2468   Matcher matcher;
2469   _matcher = &matcher;
2470   {
2471     TracePhase tp("matcher", &timers[_t_matcher]);
2472     matcher.match();
2473   }
2474   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2475   // nodes.  Mapping is only valid at the root of each matched subtree.
2476   NOT_PRODUCT( verify_graph_edges(); )
2477 
2478   // If you have too many nodes, or if matching has failed, bail out
2479   check_node_count(0, "out of nodes matching instructions");
2480   if (failing()) {
2481     return;
2482   }
2483 
2484   print_method(PHASE_MATCHING, 2);
2485 
2486   // Build a proper-looking CFG
2487   PhaseCFG cfg(node_arena(), root(), matcher);
2488   _cfg = &cfg;
2489   {
2490     TracePhase tp("scheduler", &timers[_t_scheduler]);
2491     bool success = cfg.do_global_code_motion();
2492     if (!success) {
2493       return;
2494     }
2495 
2496     print_method(PHASE_GLOBAL_CODE_MOTION, 2);
2497     NOT_PRODUCT( verify_graph_edges(); )
2498     debug_only( cfg.verify(); )
2499   }
2500 
2501   PhaseChaitin regalloc(unique(), cfg, matcher, false);
2502   _regalloc = &regalloc;
2503   {
2504     TracePhase tp("regalloc", &timers[_t_registerAllocation]);
2505     // Perform register allocation.  After Chaitin, use-def chains are
2506     // no longer accurate (at spill code) and so must be ignored.
2507     // Node->LRG->reg mappings are still accurate.
2508     _regalloc->Register_Allocate();
2509 
2510     // Bail out if the allocator builds too many nodes
2511     if (failing()) {
2512       return;
2513     }
2514   }
2515 
2516   // Prior to register allocation we kept empty basic blocks in case the
2517   // the allocator needed a place to spill.  After register allocation we
2518   // are not adding any new instructions.  If any basic block is empty, we
2519   // can now safely remove it.
2520   {
2521     TracePhase tp("blockOrdering", &timers[_t_blockOrdering]);
2522     cfg.remove_empty_blocks();
2523     if (do_freq_based_layout()) {
2524       PhaseBlockLayout layout(cfg);
2525     } else {
2526       cfg.set_loop_alignment();
2527     }
2528     cfg.fixup_flow();
2529   }
2530 
2531   // Apply peephole optimizations
2532   if( OptoPeephole ) {
2533     TracePhase tp("peephole", &timers[_t_peephole]);
2534     PhasePeephole peep( _regalloc, cfg);
2535     peep.do_transform();
2536   }
2537 
2538   // Do late expand if CPU requires this.
2539   if (Matcher::require_postalloc_expand) {
2540     TracePhase tp("postalloc_expand", &timers[_t_postalloc_expand]);
2541     cfg.postalloc_expand(_regalloc);
2542   }
2543 
2544   // Convert Nodes to instruction bits in a buffer
2545   {
2546     TraceTime tp("output", &timers[_t_output], CITime);
2547     Output();
2548   }
2549 
2550   print_method(PHASE_FINAL_CODE);
2551 
2552   // He's dead, Jim.
2553   _cfg     = (PhaseCFG*)((intptr_t)0xdeadbeef);
2554   _regalloc = (PhaseChaitin*)((intptr_t)0xdeadbeef);
2555 }
2556 
2557 
2558 //------------------------------dump_asm---------------------------------------
2559 // Dump formatted assembly
2560 #if defined(SUPPORT_OPTO_ASSEMBLY)
2561 void Compile::dump_asm_on(outputStream* st, int* pcs, uint pc_limit) {
2562 
2563   int pc_digits = 3; // #chars required for pc
2564   int sb_chars  = 3; // #chars for "start bundle" indicator
2565   int tab_size  = 8;
2566   if (pcs != NULL) {
2567     int max_pc = 0;
2568     for (uint i = 0; i < pc_limit; i++) {
2569       max_pc = (max_pc < pcs[i]) ? pcs[i] : max_pc;
2570     }
2571     pc_digits  = ((max_pc < 4096) ? 3 : ((max_pc < 65536) ? 4 : ((max_pc < 65536*256) ? 6 : 8))); // #chars required for pc
2572   }
2573   int prefix_len = ((pc_digits + sb_chars + tab_size - 1)/tab_size)*tab_size;
2574 
2575   bool cut_short = false;
2576   st->print_cr("#");
2577   st->print("#  ");  _tf->dump_on(st);  st->cr();
2578   st->print_cr("#");
2579 
2580   // For all blocks
2581   int pc = 0x0;                 // Program counter
2582   char starts_bundle = ' ';
2583   _regalloc->dump_frame();
2584 
2585   Node *n = NULL;
2586   for (uint i = 0; i < _cfg->number_of_blocks(); i++) {
2587     if (VMThread::should_terminate()) {
2588       cut_short = true;
2589       break;
2590     }
2591     Block* block = _cfg->get_block(i);
2592     if (block->is_connector() && !Verbose) {
2593       continue;
2594     }
2595     n = block->head();
2596     if ((pcs != NULL) && (n->_idx < pc_limit)) {
2597       pc = pcs[n->_idx];
2598       st->print("%*.*x", pc_digits, pc_digits, pc);
2599     }
2600     st->fill_to(prefix_len);
2601     block->dump_head(_cfg, st);
2602     if (block->is_connector()) {
2603       st->fill_to(prefix_len);
2604       st->print_cr("# Empty connector block");
2605     } else if (block->num_preds() == 2 && block->pred(1)->is_CatchProj() && block->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
2606       st->fill_to(prefix_len);
2607       st->print_cr("# Block is sole successor of call");
2608     }
2609 
2610     // For all instructions
2611     Node *delay = NULL;
2612     for (uint j = 0; j < block->number_of_nodes(); j++) {
2613       if (VMThread::should_terminate()) {
2614         cut_short = true;
2615         break;
2616       }
2617       n = block->get_node(j);
2618       if (valid_bundle_info(n)) {
2619         Bundle* bundle = node_bundling(n);
2620         if (bundle->used_in_unconditional_delay()) {
2621           delay = n;
2622           continue;
2623         }
2624         if (bundle->starts_bundle()) {
2625           starts_bundle = '+';
2626         }
2627       }
2628 
2629       if (WizardMode) {
2630         n->dump();
2631       }
2632 
2633       if( !n->is_Region() &&    // Dont print in the Assembly
2634           !n->is_Phi() &&       // a few noisely useless nodes
2635           !n->is_Proj() &&
2636           !n->is_MachTemp() &&
2637           !n->is_SafePointScalarObject() &&
2638           !n->is_Catch() &&     // Would be nice to print exception table targets
2639           !n->is_MergeMem() &&  // Not very interesting
2640           !n->is_top() &&       // Debug info table constants
2641           !(n->is_Con() && !n->is_Mach())// Debug info table constants
2642           ) {
2643         if ((pcs != NULL) && (n->_idx < pc_limit)) {
2644           pc = pcs[n->_idx];
2645           st->print("%*.*x", pc_digits, pc_digits, pc);
2646         } else {
2647           st->fill_to(pc_digits);
2648         }
2649         st->print(" %c ", starts_bundle);
2650         starts_bundle = ' ';
2651         st->fill_to(prefix_len);
2652         n->format(_regalloc, st);
2653         st->cr();
2654       }
2655 
2656       // If we have an instruction with a delay slot, and have seen a delay,
2657       // then back up and print it
2658       if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
2659         // Coverity finding - Explicit null dereferenced.
2660         guarantee(delay != NULL, "no unconditional delay instruction");
2661         if (WizardMode) delay->dump();
2662 
2663         if (node_bundling(delay)->starts_bundle())
2664           starts_bundle = '+';
2665         if ((pcs != NULL) && (n->_idx < pc_limit)) {
2666           pc = pcs[n->_idx];
2667           st->print("%*.*x", pc_digits, pc_digits, pc);
2668         } else {
2669           st->fill_to(pc_digits);
2670         }
2671         st->print(" %c ", starts_bundle);
2672         starts_bundle = ' ';
2673         st->fill_to(prefix_len);
2674         delay->format(_regalloc, st);
2675         st->cr();
2676         delay = NULL;
2677       }
2678 
2679       // Dump the exception table as well
2680       if( n->is_Catch() && (Verbose || WizardMode) ) {
2681         // Print the exception table for this offset
2682         _handler_table.print_subtable_for(pc);
2683       }
2684       st->bol(); // Make sure we start on a new line
2685     }
2686     st->cr(); // one empty line between blocks
2687     assert(cut_short || delay == NULL, "no unconditional delay branch");
2688   } // End of per-block dump
2689 
2690   if (cut_short)  st->print_cr("*** disassembly is cut short ***");
2691 }
2692 #endif
2693 
2694 //------------------------------Final_Reshape_Counts---------------------------
2695 // This class defines counters to help identify when a method
2696 // may/must be executed using hardware with only 24-bit precision.
2697 struct Final_Reshape_Counts : public StackObj {
2698   int  _call_count;             // count non-inlined 'common' calls
2699   int  _float_count;            // count float ops requiring 24-bit precision
2700   int  _double_count;           // count double ops requiring more precision
2701   int  _java_call_count;        // count non-inlined 'java' calls
2702   int  _inner_loop_count;       // count loops which need alignment
2703   VectorSet _visited;           // Visitation flags
2704   Node_List _tests;             // Set of IfNodes & PCTableNodes
2705 
2706   Final_Reshape_Counts() :
2707     _call_count(0), _float_count(0), _double_count(0),
2708     _java_call_count(0), _inner_loop_count(0),
2709     _visited( Thread::current()->resource_area() ) { }
2710 
2711   void inc_call_count  () { _call_count  ++; }
2712   void inc_float_count () { _float_count ++; }
2713   void inc_double_count() { _double_count++; }
2714   void inc_java_call_count() { _java_call_count++; }
2715   void inc_inner_loop_count() { _inner_loop_count++; }
2716 
2717   int  get_call_count  () const { return _call_count  ; }
2718   int  get_float_count () const { return _float_count ; }
2719   int  get_double_count() const { return _double_count; }
2720   int  get_java_call_count() const { return _java_call_count; }
2721   int  get_inner_loop_count() const { return _inner_loop_count; }
2722 };
2723 
2724 #ifdef ASSERT
2725 static bool oop_offset_is_sane(const TypeInstPtr* tp) {
2726   ciInstanceKlass *k = tp->klass()->as_instance_klass();
2727   // Make sure the offset goes inside the instance layout.
2728   return k->contains_field_offset(tp->offset());
2729   // Note that OffsetBot and OffsetTop are very negative.
2730 }
2731 #endif
2732 
2733 // Eliminate trivially redundant StoreCMs and accumulate their
2734 // precedence edges.
2735 void Compile::eliminate_redundant_card_marks(Node* n) {
2736   assert(n->Opcode() == Op_StoreCM, "expected StoreCM");
2737   if (n->in(MemNode::Address)->outcnt() > 1) {
2738     // There are multiple users of the same address so it might be
2739     // possible to eliminate some of the StoreCMs
2740     Node* mem = n->in(MemNode::Memory);
2741     Node* adr = n->in(MemNode::Address);
2742     Node* val = n->in(MemNode::ValueIn);
2743     Node* prev = n;
2744     bool done = false;
2745     // Walk the chain of StoreCMs eliminating ones that match.  As
2746     // long as it's a chain of single users then the optimization is
2747     // safe.  Eliminating partially redundant StoreCMs would require
2748     // cloning copies down the other paths.
2749     while (mem->Opcode() == Op_StoreCM && mem->outcnt() == 1 && !done) {
2750       if (adr == mem->in(MemNode::Address) &&
2751           val == mem->in(MemNode::ValueIn)) {
2752         // redundant StoreCM
2753         if (mem->req() > MemNode::OopStore) {
2754           // Hasn't been processed by this code yet.
2755           n->add_prec(mem->in(MemNode::OopStore));
2756         } else {
2757           // Already converted to precedence edge
2758           for (uint i = mem->req(); i < mem->len(); i++) {
2759             // Accumulate any precedence edges
2760             if (mem->in(i) != NULL) {
2761               n->add_prec(mem->in(i));
2762             }
2763           }
2764           // Everything above this point has been processed.
2765           done = true;
2766         }
2767         // Eliminate the previous StoreCM
2768         prev->set_req(MemNode::Memory, mem->in(MemNode::Memory));
2769         assert(mem->outcnt() == 0, "should be dead");
2770         mem->disconnect_inputs(NULL, this);
2771       } else {
2772         prev = mem;
2773       }
2774       mem = prev->in(MemNode::Memory);
2775     }
2776   }
2777 }
2778 
2779 //------------------------------final_graph_reshaping_impl----------------------
2780 // Implement items 1-5 from final_graph_reshaping below.
2781 void Compile::final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &frc) {
2782 
2783   if ( n->outcnt() == 0 ) return; // dead node
2784   uint nop = n->Opcode();
2785 
2786   // Check for 2-input instruction with "last use" on right input.
2787   // Swap to left input.  Implements item (2).
2788   if( n->req() == 3 &&          // two-input instruction
2789       n->in(1)->outcnt() > 1 && // left use is NOT a last use
2790       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
2791       n->in(2)->outcnt() == 1 &&// right use IS a last use
2792       !n->in(2)->is_Con() ) {   // right use is not a constant
2793     // Check for commutative opcode
2794     switch( nop ) {
2795     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddL:
2796     case Op_MaxI:  case Op_MinI:
2797     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulL:
2798     case Op_AndL:  case Op_XorL:  case Op_OrL:
2799     case Op_AndI:  case Op_XorI:  case Op_OrI: {
2800       // Move "last use" input to left by swapping inputs
2801       n->swap_edges(1, 2);
2802       break;
2803     }
2804     default:
2805       break;
2806     }
2807   }
2808 
2809 #ifdef ASSERT
2810   if( n->is_Mem() ) {
2811     int alias_idx = get_alias_index(n->as_Mem()->adr_type());
2812     assert( n->in(0) != NULL || alias_idx != Compile::AliasIdxRaw ||
2813             // oop will be recorded in oop map if load crosses safepoint
2814             n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
2815                              LoadNode::is_immutable_value(n->in(MemNode::Address))),
2816             "raw memory operations should have control edge");
2817   }
2818   if (n->is_MemBar()) {
2819     MemBarNode* mb = n->as_MemBar();
2820     if (mb->trailing_store() || mb->trailing_load_store()) {
2821       assert(mb->leading_membar()->trailing_membar() == mb, "bad membar pair");
2822       Node* mem = mb->in(MemBarNode::Precedent);
2823       assert((mb->trailing_store() && mem->is_Store() && mem->as_Store()->is_release()) ||
2824              (mb->trailing_load_store() && mem->is_LoadStore()), "missing mem op");
2825     } else if (mb->leading()) {
2826       assert(mb->trailing_membar()->leading_membar() == mb, "bad membar pair");
2827     }
2828   }
2829 #endif
2830   // Count FPU ops and common calls, implements item (3)
2831   bool gc_handled = BarrierSet::barrier_set()->barrier_set_c2()->final_graph_reshaping(this, n, nop);
2832   if (!gc_handled) {
2833     final_graph_reshaping_main_switch(n, frc, nop);
2834   }
2835 
2836   // Collect CFG split points
2837   if (n->is_MultiBranch() && !n->is_RangeCheck()) {
2838     frc._tests.push(n);
2839   }
2840 }
2841 
2842 void Compile::final_graph_reshaping_main_switch(Node* n, Final_Reshape_Counts& frc, uint nop) {
2843   switch( nop ) {
2844   // Count all float operations that may use FPU
2845   case Op_AddF:
2846   case Op_SubF:
2847   case Op_MulF:
2848   case Op_DivF:
2849   case Op_NegF:
2850   case Op_ModF:
2851   case Op_ConvI2F:
2852   case Op_ConF:
2853   case Op_CmpF:
2854   case Op_CmpF3:
2855   // case Op_ConvL2F: // longs are split into 32-bit halves
2856     frc.inc_float_count();
2857     break;
2858 
2859   case Op_ConvF2D:
2860   case Op_ConvD2F:
2861     frc.inc_float_count();
2862     frc.inc_double_count();
2863     break;
2864 
2865   // Count all double operations that may use FPU
2866   case Op_AddD:
2867   case Op_SubD:
2868   case Op_MulD:
2869   case Op_DivD:
2870   case Op_NegD:
2871   case Op_ModD:
2872   case Op_ConvI2D:
2873   case Op_ConvD2I:
2874   // case Op_ConvL2D: // handled by leaf call
2875   // case Op_ConvD2L: // handled by leaf call
2876   case Op_ConD:
2877   case Op_CmpD:
2878   case Op_CmpD3:
2879     frc.inc_double_count();
2880     break;
2881   case Op_Opaque1:              // Remove Opaque Nodes before matching
2882   case Op_Opaque2:              // Remove Opaque Nodes before matching
2883   case Op_Opaque3:
2884     n->subsume_by(n->in(1), this);
2885     break;
2886   case Op_CallStaticJava:
2887   case Op_CallJava:
2888   case Op_CallDynamicJava:
2889     frc.inc_java_call_count(); // Count java call site;
2890   case Op_CallRuntime:
2891   case Op_CallLeaf:
2892   case Op_CallLeafNoFP: {
2893     assert (n->is_Call(), "");
2894     CallNode *call = n->as_Call();
2895     // Count call sites where the FP mode bit would have to be flipped.
2896     // Do not count uncommon runtime calls:
2897     // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
2898     // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
2899     if (!call->is_CallStaticJava() || !call->as_CallStaticJava()->_name) {
2900       frc.inc_call_count();   // Count the call site
2901     } else {                  // See if uncommon argument is shared
2902       Node *n = call->in(TypeFunc::Parms);
2903       int nop = n->Opcode();
2904       // Clone shared simple arguments to uncommon calls, item (1).
2905       if (n->outcnt() > 1 &&
2906           !n->is_Proj() &&
2907           nop != Op_CreateEx &&
2908           nop != Op_CheckCastPP &&
2909           nop != Op_DecodeN &&
2910           nop != Op_DecodeNKlass &&
2911           !n->is_Mem() &&
2912           !n->is_Phi()) {
2913         Node *x = n->clone();
2914         call->set_req(TypeFunc::Parms, x);
2915       }
2916     }
2917     break;
2918   }
2919 
2920   case Op_StoreD:
2921   case Op_LoadD:
2922   case Op_LoadD_unaligned:
2923     frc.inc_double_count();
2924     goto handle_mem;
2925   case Op_StoreF:
2926   case Op_LoadF:
2927     frc.inc_float_count();
2928     goto handle_mem;
2929 
2930   case Op_StoreCM:
2931     {
2932       // Convert OopStore dependence into precedence edge
2933       Node* prec = n->in(MemNode::OopStore);
2934       n->del_req(MemNode::OopStore);
2935       n->add_prec(prec);
2936       eliminate_redundant_card_marks(n);
2937     }
2938 
2939     // fall through
2940 
2941   case Op_StoreB:
2942   case Op_StoreC:
2943   case Op_StorePConditional:
2944   case Op_StoreI:
2945   case Op_StoreL:
2946   case Op_StoreIConditional:
2947   case Op_StoreLConditional:
2948   case Op_CompareAndSwapB:
2949   case Op_CompareAndSwapS:
2950   case Op_CompareAndSwapI:
2951   case Op_CompareAndSwapL:
2952   case Op_CompareAndSwapP:
2953   case Op_CompareAndSwapN:
2954   case Op_WeakCompareAndSwapB:
2955   case Op_WeakCompareAndSwapS:
2956   case Op_WeakCompareAndSwapI:
2957   case Op_WeakCompareAndSwapL:
2958   case Op_WeakCompareAndSwapP:
2959   case Op_WeakCompareAndSwapN:
2960   case Op_CompareAndExchangeB:
2961   case Op_CompareAndExchangeS:
2962   case Op_CompareAndExchangeI:
2963   case Op_CompareAndExchangeL:
2964   case Op_CompareAndExchangeP:
2965   case Op_CompareAndExchangeN:
2966   case Op_GetAndAddS:
2967   case Op_GetAndAddB:
2968   case Op_GetAndAddI:
2969   case Op_GetAndAddL:
2970   case Op_GetAndSetS:
2971   case Op_GetAndSetB:
2972   case Op_GetAndSetI:
2973   case Op_GetAndSetL:
2974   case Op_GetAndSetP:
2975   case Op_GetAndSetN:
2976   case Op_StoreP:
2977   case Op_StoreN:
2978   case Op_StoreNKlass:
2979   case Op_LoadB:
2980   case Op_LoadUB:
2981   case Op_LoadUS:
2982   case Op_LoadI:
2983   case Op_LoadKlass:
2984   case Op_LoadNKlass:
2985   case Op_LoadL:
2986   case Op_LoadL_unaligned:
2987   case Op_LoadPLocked:
2988   case Op_LoadP:
2989   case Op_LoadN:
2990   case Op_LoadRange:
2991   case Op_LoadS: {
2992   handle_mem:
2993 #ifdef ASSERT
2994     if( VerifyOptoOopOffsets ) {
2995       MemNode* mem  = n->as_Mem();
2996       // Check to see if address types have grounded out somehow.
2997       const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
2998       assert( !tp || oop_offset_is_sane(tp), "" );
2999     }
3000 #endif
3001     break;
3002   }
3003 
3004   case Op_AddP: {               // Assert sane base pointers
3005     Node *addp = n->in(AddPNode::Address);
3006     assert( !addp->is_AddP() ||
3007             addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
3008             addp->in(AddPNode::Base) == n->in(AddPNode::Base),
3009             "Base pointers must match (addp %u)", addp->_idx );
3010 #ifdef _LP64
3011     if ((UseCompressedOops || UseCompressedClassPointers) &&
3012         addp->Opcode() == Op_ConP &&
3013         addp == n->in(AddPNode::Base) &&
3014         n->in(AddPNode::Offset)->is_Con()) {
3015       // If the transformation of ConP to ConN+DecodeN is beneficial depends
3016       // on the platform and on the compressed oops mode.
3017       // Use addressing with narrow klass to load with offset on x86.
3018       // Some platforms can use the constant pool to load ConP.
3019       // Do this transformation here since IGVN will convert ConN back to ConP.
3020       const Type* t = addp->bottom_type();
3021       bool is_oop   = t->isa_oopptr() != NULL;
3022       bool is_klass = t->isa_klassptr() != NULL;
3023 
3024       if ((is_oop   && Matcher::const_oop_prefer_decode()  ) ||
3025           (is_klass && Matcher::const_klass_prefer_decode())) {
3026         Node* nn = NULL;
3027 
3028         int op = is_oop ? Op_ConN : Op_ConNKlass;
3029 
3030         // Look for existing ConN node of the same exact type.
3031         Node* r  = root();
3032         uint cnt = r->outcnt();
3033         for (uint i = 0; i < cnt; i++) {
3034           Node* m = r->raw_out(i);
3035           if (m!= NULL && m->Opcode() == op &&
3036               m->bottom_type()->make_ptr() == t) {
3037             nn = m;
3038             break;
3039           }
3040         }
3041         if (nn != NULL) {
3042           // Decode a narrow oop to match address
3043           // [R12 + narrow_oop_reg<<3 + offset]
3044           if (is_oop) {
3045             nn = new DecodeNNode(nn, t);
3046           } else {
3047             nn = new DecodeNKlassNode(nn, t);
3048           }
3049           // Check for succeeding AddP which uses the same Base.
3050           // Otherwise we will run into the assertion above when visiting that guy.
3051           for (uint i = 0; i < n->outcnt(); ++i) {
3052             Node *out_i = n->raw_out(i);
3053             if (out_i && out_i->is_AddP() && out_i->in(AddPNode::Base) == addp) {
3054               out_i->set_req(AddPNode::Base, nn);
3055 #ifdef ASSERT
3056               for (uint j = 0; j < out_i->outcnt(); ++j) {
3057                 Node *out_j = out_i->raw_out(j);
3058                 assert(out_j == NULL || !out_j->is_AddP() || out_j->in(AddPNode::Base) != addp,
3059                        "more than 2 AddP nodes in a chain (out_j %u)", out_j->_idx);
3060               }
3061 #endif
3062             }
3063           }
3064           n->set_req(AddPNode::Base, nn);
3065           n->set_req(AddPNode::Address, nn);
3066           if (addp->outcnt() == 0) {
3067             addp->disconnect_inputs(NULL, this);
3068           }
3069         }
3070       }
3071     }
3072 #endif
3073     // platform dependent reshaping of the address expression
3074     reshape_address(n->as_AddP());
3075     break;
3076   }
3077 
3078   case Op_CastPP: {
3079     // Remove CastPP nodes to gain more freedom during scheduling but
3080     // keep the dependency they encode as control or precedence edges
3081     // (if control is set already) on memory operations. Some CastPP
3082     // nodes don't have a control (don't carry a dependency): skip
3083     // those.
3084     if (n->in(0) != NULL) {
3085       ResourceMark rm;
3086       Unique_Node_List wq;
3087       wq.push(n);
3088       for (uint next = 0; next < wq.size(); ++next) {
3089         Node *m = wq.at(next);
3090         for (DUIterator_Fast imax, i = m->fast_outs(imax); i < imax; i++) {
3091           Node* use = m->fast_out(i);
3092           if (use->is_Mem() || use->is_EncodeNarrowPtr()) {
3093             use->ensure_control_or_add_prec(n->in(0));
3094           } else {
3095             switch(use->Opcode()) {
3096             case Op_AddP:
3097             case Op_DecodeN:
3098             case Op_DecodeNKlass:
3099             case Op_CheckCastPP:
3100             case Op_CastPP:
3101               wq.push(use);
3102               break;
3103             }
3104           }
3105         }
3106       }
3107     }
3108     const bool is_LP64 = LP64_ONLY(true) NOT_LP64(false);
3109     if (is_LP64 && n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
3110       Node* in1 = n->in(1);
3111       const Type* t = n->bottom_type();
3112       Node* new_in1 = in1->clone();
3113       new_in1->as_DecodeN()->set_type(t);
3114 
3115       if (!Matcher::narrow_oop_use_complex_address()) {
3116         //
3117         // x86, ARM and friends can handle 2 adds in addressing mode
3118         // and Matcher can fold a DecodeN node into address by using
3119         // a narrow oop directly and do implicit NULL check in address:
3120         //
3121         // [R12 + narrow_oop_reg<<3 + offset]
3122         // NullCheck narrow_oop_reg
3123         //
3124         // On other platforms (Sparc) we have to keep new DecodeN node and
3125         // use it to do implicit NULL check in address:
3126         //
3127         // decode_not_null narrow_oop_reg, base_reg
3128         // [base_reg + offset]
3129         // NullCheck base_reg
3130         //
3131         // Pin the new DecodeN node to non-null path on these platform (Sparc)
3132         // to keep the information to which NULL check the new DecodeN node
3133         // corresponds to use it as value in implicit_null_check().
3134         //
3135         new_in1->set_req(0, n->in(0));
3136       }
3137 
3138       n->subsume_by(new_in1, this);
3139       if (in1->outcnt() == 0) {
3140         in1->disconnect_inputs(NULL, this);
3141       }
3142     } else {
3143       n->subsume_by(n->in(1), this);
3144       if (n->outcnt() == 0) {
3145         n->disconnect_inputs(NULL, this);
3146       }
3147     }
3148     break;
3149   }
3150 #ifdef _LP64
3151   case Op_CmpP:
3152     // Do this transformation here to preserve CmpPNode::sub() and
3153     // other TypePtr related Ideal optimizations (for example, ptr nullness).
3154     if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
3155       Node* in1 = n->in(1);
3156       Node* in2 = n->in(2);
3157       if (!in1->is_DecodeNarrowPtr()) {
3158         in2 = in1;
3159         in1 = n->in(2);
3160       }
3161       assert(in1->is_DecodeNarrowPtr(), "sanity");
3162 
3163       Node* new_in2 = NULL;
3164       if (in2->is_DecodeNarrowPtr()) {
3165         assert(in2->Opcode() == in1->Opcode(), "must be same node type");
3166         new_in2 = in2->in(1);
3167       } else if (in2->Opcode() == Op_ConP) {
3168         const Type* t = in2->bottom_type();
3169         if (t == TypePtr::NULL_PTR) {
3170           assert(in1->is_DecodeN(), "compare klass to null?");
3171           // Don't convert CmpP null check into CmpN if compressed
3172           // oops implicit null check is not generated.
3173           // This will allow to generate normal oop implicit null check.
3174           if (Matcher::gen_narrow_oop_implicit_null_checks())
3175             new_in2 = ConNode::make(TypeNarrowOop::NULL_PTR);
3176           //
3177           // This transformation together with CastPP transformation above
3178           // will generated code for implicit NULL checks for compressed oops.
3179           //
3180           // The original code after Optimize()
3181           //
3182           //    LoadN memory, narrow_oop_reg
3183           //    decode narrow_oop_reg, base_reg
3184           //    CmpP base_reg, NULL
3185           //    CastPP base_reg // NotNull
3186           //    Load [base_reg + offset], val_reg
3187           //
3188           // after these transformations will be
3189           //
3190           //    LoadN memory, narrow_oop_reg
3191           //    CmpN narrow_oop_reg, NULL
3192           //    decode_not_null narrow_oop_reg, base_reg
3193           //    Load [base_reg + offset], val_reg
3194           //
3195           // and the uncommon path (== NULL) will use narrow_oop_reg directly
3196           // since narrow oops can be used in debug info now (see the code in
3197           // final_graph_reshaping_walk()).
3198           //
3199           // At the end the code will be matched to
3200           // on x86:
3201           //
3202           //    Load_narrow_oop memory, narrow_oop_reg
3203           //    Load [R12 + narrow_oop_reg<<3 + offset], val_reg
3204           //    NullCheck narrow_oop_reg
3205           //
3206           // and on sparc:
3207           //
3208           //    Load_narrow_oop memory, narrow_oop_reg
3209           //    decode_not_null narrow_oop_reg, base_reg
3210           //    Load [base_reg + offset], val_reg
3211           //    NullCheck base_reg
3212           //
3213         } else if (t->isa_oopptr()) {
3214           new_in2 = ConNode::make(t->make_narrowoop());
3215         } else if (t->isa_klassptr()) {
3216           new_in2 = ConNode::make(t->make_narrowklass());
3217         }
3218       }
3219       if (new_in2 != NULL) {
3220         Node* cmpN = new CmpNNode(in1->in(1), new_in2);
3221         n->subsume_by(cmpN, this);
3222         if (in1->outcnt() == 0) {
3223           in1->disconnect_inputs(NULL, this);
3224         }
3225         if (in2->outcnt() == 0) {
3226           in2->disconnect_inputs(NULL, this);
3227         }
3228       }
3229     }
3230     break;
3231 
3232   case Op_DecodeN:
3233   case Op_DecodeNKlass:
3234     assert(!n->in(1)->is_EncodeNarrowPtr(), "should be optimized out");
3235     // DecodeN could be pinned when it can't be fold into
3236     // an address expression, see the code for Op_CastPP above.
3237     assert(n->in(0) == NULL || (UseCompressedOops && !Matcher::narrow_oop_use_complex_address()), "no control");
3238     break;
3239 
3240   case Op_EncodeP:
3241   case Op_EncodePKlass: {
3242     Node* in1 = n->in(1);
3243     if (in1->is_DecodeNarrowPtr()) {
3244       n->subsume_by(in1->in(1), this);
3245     } else if (in1->Opcode() == Op_ConP) {
3246       const Type* t = in1->bottom_type();
3247       if (t == TypePtr::NULL_PTR) {
3248         assert(t->isa_oopptr(), "null klass?");
3249         n->subsume_by(ConNode::make(TypeNarrowOop::NULL_PTR), this);
3250       } else if (t->isa_oopptr()) {
3251         n->subsume_by(ConNode::make(t->make_narrowoop()), this);
3252       } else if (t->isa_klassptr()) {
3253         n->subsume_by(ConNode::make(t->make_narrowklass()), this);
3254       }
3255     }
3256     if (in1->outcnt() == 0) {
3257       in1->disconnect_inputs(NULL, this);
3258     }
3259     break;
3260   }
3261 
3262   case Op_Proj: {
3263     if (OptimizeStringConcat) {
3264       ProjNode* p = n->as_Proj();
3265       if (p->_is_io_use) {
3266         // Separate projections were used for the exception path which
3267         // are normally removed by a late inline.  If it wasn't inlined
3268         // then they will hang around and should just be replaced with
3269         // the original one.
3270         Node* proj = NULL;
3271         // Replace with just one
3272         for (SimpleDUIterator i(p->in(0)); i.has_next(); i.next()) {
3273           Node *use = i.get();
3274           if (use->is_Proj() && p != use && use->as_Proj()->_con == p->_con) {
3275             proj = use;
3276             break;
3277           }
3278         }
3279         assert(proj != NULL || p->_con == TypeFunc::I_O, "io may be dropped at an infinite loop");
3280         if (proj != NULL) {
3281           p->subsume_by(proj, this);
3282         }
3283       }
3284     }
3285     break;
3286   }
3287 
3288   case Op_Phi:
3289     if (n->as_Phi()->bottom_type()->isa_narrowoop() || n->as_Phi()->bottom_type()->isa_narrowklass()) {
3290       // The EncodeP optimization may create Phi with the same edges
3291       // for all paths. It is not handled well by Register Allocator.
3292       Node* unique_in = n->in(1);
3293       assert(unique_in != NULL, "");
3294       uint cnt = n->req();
3295       for (uint i = 2; i < cnt; i++) {
3296         Node* m = n->in(i);
3297         assert(m != NULL, "");
3298         if (unique_in != m)
3299           unique_in = NULL;
3300       }
3301       if (unique_in != NULL) {
3302         n->subsume_by(unique_in, this);
3303       }
3304     }
3305     break;
3306 
3307 #endif
3308 
3309 #ifdef ASSERT
3310   case Op_CastII:
3311     // Verify that all range check dependent CastII nodes were removed.
3312     if (n->isa_CastII()->has_range_check()) {
3313       n->dump(3);
3314       assert(false, "Range check dependent CastII node was not removed");
3315     }
3316     break;
3317 #endif
3318 
3319   case Op_ModI:
3320     if (UseDivMod) {
3321       // Check if a%b and a/b both exist
3322       Node* d = n->find_similar(Op_DivI);
3323       if (d) {
3324         // Replace them with a fused divmod if supported
3325         if (Matcher::has_match_rule(Op_DivModI)) {
3326           DivModINode* divmod = DivModINode::make(n);
3327           d->subsume_by(divmod->div_proj(), this);
3328           n->subsume_by(divmod->mod_proj(), this);
3329         } else {
3330           // replace a%b with a-((a/b)*b)
3331           Node* mult = new MulINode(d, d->in(2));
3332           Node* sub  = new SubINode(d->in(1), mult);
3333           n->subsume_by(sub, this);
3334         }
3335       }
3336     }
3337     break;
3338 
3339   case Op_ModL:
3340     if (UseDivMod) {
3341       // Check if a%b and a/b both exist
3342       Node* d = n->find_similar(Op_DivL);
3343       if (d) {
3344         // Replace them with a fused divmod if supported
3345         if (Matcher::has_match_rule(Op_DivModL)) {
3346           DivModLNode* divmod = DivModLNode::make(n);
3347           d->subsume_by(divmod->div_proj(), this);
3348           n->subsume_by(divmod->mod_proj(), this);
3349         } else {
3350           // replace a%b with a-((a/b)*b)
3351           Node* mult = new MulLNode(d, d->in(2));
3352           Node* sub  = new SubLNode(d->in(1), mult);
3353           n->subsume_by(sub, this);
3354         }
3355       }
3356     }
3357     break;
3358 
3359   case Op_LoadVector:
3360   case Op_StoreVector:
3361     break;
3362 
3363   case Op_AddReductionVI:
3364   case Op_AddReductionVL:
3365   case Op_AddReductionVF:
3366   case Op_AddReductionVD:
3367   case Op_MulReductionVI:
3368   case Op_MulReductionVL:
3369   case Op_MulReductionVF:
3370   case Op_MulReductionVD:
3371   case Op_MinReductionV:
3372   case Op_MaxReductionV:
3373     break;
3374 
3375   case Op_PackB:
3376   case Op_PackS:
3377   case Op_PackI:
3378   case Op_PackF:
3379   case Op_PackL:
3380   case Op_PackD:
3381     if (n->req()-1 > 2) {
3382       // Replace many operand PackNodes with a binary tree for matching
3383       PackNode* p = (PackNode*) n;
3384       Node* btp = p->binary_tree_pack(1, n->req());
3385       n->subsume_by(btp, this);
3386     }
3387     break;
3388   case Op_Loop:
3389   case Op_CountedLoop:
3390   case Op_OuterStripMinedLoop:
3391     if (n->as_Loop()->is_inner_loop()) {
3392       frc.inc_inner_loop_count();
3393     }
3394     n->as_Loop()->verify_strip_mined(0);
3395     break;
3396   case Op_LShiftI:
3397   case Op_RShiftI:
3398   case Op_URShiftI:
3399   case Op_LShiftL:
3400   case Op_RShiftL:
3401   case Op_URShiftL:
3402     if (Matcher::need_masked_shift_count) {
3403       // The cpu's shift instructions don't restrict the count to the
3404       // lower 5/6 bits. We need to do the masking ourselves.
3405       Node* in2 = n->in(2);
3406       juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
3407       const TypeInt* t = in2->find_int_type();
3408       if (t != NULL && t->is_con()) {
3409         juint shift = t->get_con();
3410         if (shift > mask) { // Unsigned cmp
3411           n->set_req(2, ConNode::make(TypeInt::make(shift & mask)));
3412         }
3413       } else {
3414         if (t == NULL || t->_lo < 0 || t->_hi > (int)mask) {
3415           Node* shift = new AndINode(in2, ConNode::make(TypeInt::make(mask)));
3416           n->set_req(2, shift);
3417         }
3418       }
3419       if (in2->outcnt() == 0) { // Remove dead node
3420         in2->disconnect_inputs(NULL, this);
3421       }
3422     }
3423     break;
3424   case Op_MemBarStoreStore:
3425   case Op_MemBarRelease:
3426     // Break the link with AllocateNode: it is no longer useful and
3427     // confuses register allocation.
3428     if (n->req() > MemBarNode::Precedent) {
3429       n->set_req(MemBarNode::Precedent, top());
3430     }
3431     break;
3432   case Op_MemBarAcquire: {
3433     if (n->as_MemBar()->trailing_load() && n->req() > MemBarNode::Precedent) {
3434       // At parse time, the trailing MemBarAcquire for a volatile load
3435       // is created with an edge to the load. After optimizations,
3436       // that input may be a chain of Phis. If those phis have no
3437       // other use, then the MemBarAcquire keeps them alive and
3438       // register allocation can be confused.
3439       ResourceMark rm;
3440       Unique_Node_List wq;
3441       wq.push(n->in(MemBarNode::Precedent));
3442       n->set_req(MemBarNode::Precedent, top());
3443       while (wq.size() > 0) {
3444         Node* m = wq.pop();
3445         if (m->outcnt() == 0) {
3446           for (uint j = 0; j < m->req(); j++) {
3447             Node* in = m->in(j);
3448             if (in != NULL) {
3449               wq.push(in);
3450             }
3451           }
3452           m->disconnect_inputs(NULL, this);
3453         }
3454       }
3455     }
3456     break;
3457   }
3458   case Op_RangeCheck: {
3459     RangeCheckNode* rc = n->as_RangeCheck();
3460     Node* iff = new IfNode(rc->in(0), rc->in(1), rc->_prob, rc->_fcnt);
3461     n->subsume_by(iff, this);
3462     frc._tests.push(iff);
3463     break;
3464   }
3465   case Op_ConvI2L: {
3466     if (!Matcher::convi2l_type_required) {
3467       // Code generation on some platforms doesn't need accurate
3468       // ConvI2L types. Widening the type can help remove redundant
3469       // address computations.
3470       n->as_Type()->set_type(TypeLong::INT);
3471       ResourceMark rm;
3472       Node_List wq;
3473       wq.push(n);
3474       for (uint next = 0; next < wq.size(); next++) {
3475         Node *m = wq.at(next);
3476 
3477         for(;;) {
3478           // Loop over all nodes with identical inputs edges as m
3479           Node* k = m->find_similar(m->Opcode());
3480           if (k == NULL) {
3481             break;
3482           }
3483           // Push their uses so we get a chance to remove node made
3484           // redundant
3485           for (DUIterator_Fast imax, i = k->fast_outs(imax); i < imax; i++) {
3486             Node* u = k->fast_out(i);
3487             assert(!wq.contains(u), "shouldn't process one node several times");
3488             if (u->Opcode() == Op_LShiftL ||
3489                 u->Opcode() == Op_AddL ||
3490                 u->Opcode() == Op_SubL ||
3491                 u->Opcode() == Op_AddP) {
3492               wq.push(u);
3493             }
3494           }
3495           // Replace all nodes with identical edges as m with m
3496           k->subsume_by(m, this);
3497         }
3498       }
3499     }
3500     break;
3501   }
3502   case Op_CmpUL: {
3503     if (!Matcher::has_match_rule(Op_CmpUL)) {
3504       // No support for unsigned long comparisons
3505       ConINode* sign_pos = new ConINode(TypeInt::make(BitsPerLong - 1));
3506       Node* sign_bit_mask = new RShiftLNode(n->in(1), sign_pos);
3507       Node* orl = new OrLNode(n->in(1), sign_bit_mask);
3508       ConLNode* remove_sign_mask = new ConLNode(TypeLong::make(max_jlong));
3509       Node* andl = new AndLNode(orl, remove_sign_mask);
3510       Node* cmp = new CmpLNode(andl, n->in(2));
3511       n->subsume_by(cmp, this);
3512     }
3513     break;
3514   }
3515   default:
3516     assert(!n->is_Call(), "");
3517     assert(!n->is_Mem(), "");
3518     assert(nop != Op_ProfileBoolean, "should be eliminated during IGVN");
3519     break;
3520   }
3521 }
3522 
3523 //------------------------------final_graph_reshaping_walk---------------------
3524 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
3525 // requires that the walk visits a node's inputs before visiting the node.
3526 void Compile::final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Reshape_Counts &frc ) {
3527   ResourceArea *area = Thread::current()->resource_area();
3528   Unique_Node_List sfpt(area);
3529 
3530   frc._visited.set(root->_idx); // first, mark node as visited
3531   uint cnt = root->req();
3532   Node *n = root;
3533   uint  i = 0;
3534   while (true) {
3535     if (i < cnt) {
3536       // Place all non-visited non-null inputs onto stack
3537       Node* m = n->in(i);
3538       ++i;
3539       if (m != NULL && !frc._visited.test_set(m->_idx)) {
3540         if (m->is_SafePoint() && m->as_SafePoint()->jvms() != NULL) {
3541           // compute worst case interpreter size in case of a deoptimization
3542           update_interpreter_frame_size(m->as_SafePoint()->jvms()->interpreter_frame_size());
3543 
3544           sfpt.push(m);
3545         }
3546         cnt = m->req();
3547         nstack.push(n, i); // put on stack parent and next input's index
3548         n = m;
3549         i = 0;
3550       }
3551     } else {
3552       // Now do post-visit work
3553       final_graph_reshaping_impl( n, frc );
3554       if (nstack.is_empty())
3555         break;             // finished
3556       n = nstack.node();   // Get node from stack
3557       cnt = n->req();
3558       i = nstack.index();
3559       nstack.pop();        // Shift to the next node on stack
3560     }
3561   }
3562 
3563   // Skip next transformation if compressed oops are not used.
3564   if ((UseCompressedOops && !Matcher::gen_narrow_oop_implicit_null_checks()) ||
3565       (!UseCompressedOops && !UseCompressedClassPointers))
3566     return;
3567 
3568   // Go over safepoints nodes to skip DecodeN/DecodeNKlass nodes for debug edges.
3569   // It could be done for an uncommon traps or any safepoints/calls
3570   // if the DecodeN/DecodeNKlass node is referenced only in a debug info.
3571   while (sfpt.size() > 0) {
3572     n = sfpt.pop();
3573     JVMState *jvms = n->as_SafePoint()->jvms();
3574     assert(jvms != NULL, "sanity");
3575     int start = jvms->debug_start();
3576     int end   = n->req();
3577     bool is_uncommon = (n->is_CallStaticJava() &&
3578                         n->as_CallStaticJava()->uncommon_trap_request() != 0);
3579     for (int j = start; j < end; j++) {
3580       Node* in = n->in(j);
3581       if (in->is_DecodeNarrowPtr()) {
3582         bool safe_to_skip = true;
3583         if (!is_uncommon ) {
3584           // Is it safe to skip?
3585           for (uint i = 0; i < in->outcnt(); i++) {
3586             Node* u = in->raw_out(i);
3587             if (!u->is_SafePoint() ||
3588                 (u->is_Call() && u->as_Call()->has_non_debug_use(n))) {
3589               safe_to_skip = false;
3590             }
3591           }
3592         }
3593         if (safe_to_skip) {
3594           n->set_req(j, in->in(1));
3595         }
3596         if (in->outcnt() == 0) {
3597           in->disconnect_inputs(NULL, this);
3598         }
3599       }
3600     }
3601   }
3602 }
3603 
3604 //------------------------------final_graph_reshaping--------------------------
3605 // Final Graph Reshaping.
3606 //
3607 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
3608 //     and not commoned up and forced early.  Must come after regular
3609 //     optimizations to avoid GVN undoing the cloning.  Clone constant
3610 //     inputs to Loop Phis; these will be split by the allocator anyways.
3611 //     Remove Opaque nodes.
3612 // (2) Move last-uses by commutative operations to the left input to encourage
3613 //     Intel update-in-place two-address operations and better register usage
3614 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
3615 //     calls canonicalizing them back.
3616 // (3) Count the number of double-precision FP ops, single-precision FP ops
3617 //     and call sites.  On Intel, we can get correct rounding either by
3618 //     forcing singles to memory (requires extra stores and loads after each
3619 //     FP bytecode) or we can set a rounding mode bit (requires setting and
3620 //     clearing the mode bit around call sites).  The mode bit is only used
3621 //     if the relative frequency of single FP ops to calls is low enough.
3622 //     This is a key transform for SPEC mpeg_audio.
3623 // (4) Detect infinite loops; blobs of code reachable from above but not
3624 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
3625 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
3626 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
3627 //     Detection is by looking for IfNodes where only 1 projection is
3628 //     reachable from below or CatchNodes missing some targets.
3629 // (5) Assert for insane oop offsets in debug mode.
3630 
3631 bool Compile::final_graph_reshaping() {
3632   // an infinite loop may have been eliminated by the optimizer,
3633   // in which case the graph will be empty.
3634   if (root()->req() == 1) {
3635     record_method_not_compilable("trivial infinite loop");
3636     return true;
3637   }
3638 
3639   // Expensive nodes have their control input set to prevent the GVN
3640   // from freely commoning them. There's no GVN beyond this point so
3641   // no need to keep the control input. We want the expensive nodes to
3642   // be freely moved to the least frequent code path by gcm.
3643   assert(OptimizeExpensiveOps || expensive_count() == 0, "optimization off but list non empty?");
3644   for (int i = 0; i < expensive_count(); i++) {
3645     _expensive_nodes->at(i)->set_req(0, NULL);
3646   }
3647 
3648   Final_Reshape_Counts frc;
3649 
3650   // Visit everybody reachable!
3651   // Allocate stack of size C->live_nodes()/2 to avoid frequent realloc
3652   Node_Stack nstack(live_nodes() >> 1);
3653   final_graph_reshaping_walk(nstack, root(), frc);
3654 
3655   // Check for unreachable (from below) code (i.e., infinite loops).
3656   for( uint i = 0; i < frc._tests.size(); i++ ) {
3657     MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
3658     // Get number of CFG targets.
3659     // Note that PCTables include exception targets after calls.
3660     uint required_outcnt = n->required_outcnt();
3661     if (n->outcnt() != required_outcnt) {
3662       // Check for a few special cases.  Rethrow Nodes never take the
3663       // 'fall-thru' path, so expected kids is 1 less.
3664       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
3665         if (n->in(0)->in(0)->is_Call()) {
3666           CallNode *call = n->in(0)->in(0)->as_Call();
3667           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
3668             required_outcnt--;      // Rethrow always has 1 less kid
3669           } else if (call->req() > TypeFunc::Parms &&
3670                      call->is_CallDynamicJava()) {
3671             // Check for null receiver. In such case, the optimizer has
3672             // detected that the virtual call will always result in a null
3673             // pointer exception. The fall-through projection of this CatchNode
3674             // will not be populated.
3675             Node *arg0 = call->in(TypeFunc::Parms);
3676             if (arg0->is_Type() &&
3677                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
3678               required_outcnt--;
3679             }
3680           } else if (call->entry_point() == OptoRuntime::new_array_Java() &&
3681                      call->req() > TypeFunc::Parms+1 &&
3682                      call->is_CallStaticJava()) {
3683             // Check for negative array length. In such case, the optimizer has
3684             // detected that the allocation attempt will always result in an
3685             // exception. There is no fall-through projection of this CatchNode .
3686             Node *arg1 = call->in(TypeFunc::Parms+1);
3687             if (arg1->is_Type() &&
3688                 arg1->as_Type()->type()->join(TypeInt::POS)->empty()) {
3689               required_outcnt--;
3690             }
3691           }
3692         }
3693       }
3694       // Recheck with a better notion of 'required_outcnt'
3695       if (n->outcnt() != required_outcnt) {
3696         record_method_not_compilable("malformed control flow");
3697         return true;            // Not all targets reachable!
3698       }
3699     }
3700     // Check that I actually visited all kids.  Unreached kids
3701     // must be infinite loops.
3702     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
3703       if (!frc._visited.test(n->fast_out(j)->_idx)) {
3704         record_method_not_compilable("infinite loop");
3705         return true;            // Found unvisited kid; must be unreach
3706       }
3707 
3708     // Here so verification code in final_graph_reshaping_walk()
3709     // always see an OuterStripMinedLoopEnd
3710     if (n->is_OuterStripMinedLoopEnd()) {
3711       IfNode* init_iff = n->as_If();
3712       Node* iff = new IfNode(init_iff->in(0), init_iff->in(1), init_iff->_prob, init_iff->_fcnt);
3713       n->subsume_by(iff, this);
3714     }
3715   }
3716 
3717   // If original bytecodes contained a mixture of floats and doubles
3718   // check if the optimizer has made it homogenous, item (3).
3719   if( Use24BitFPMode && Use24BitFP && UseSSE == 0 &&
3720       frc.get_float_count() > 32 &&
3721       frc.get_double_count() == 0 &&
3722       (10 * frc.get_call_count() < frc.get_float_count()) ) {
3723     set_24_bit_selection_and_mode( false,  true );
3724   }
3725 
3726   set_java_calls(frc.get_java_call_count());
3727   set_inner_loops(frc.get_inner_loop_count());
3728 
3729   // No infinite loops, no reason to bail out.
3730   return false;
3731 }
3732 
3733 //-----------------------------too_many_traps----------------------------------
3734 // Report if there are too many traps at the current method and bci.
3735 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
3736 bool Compile::too_many_traps(ciMethod* method,
3737                              int bci,
3738                              Deoptimization::DeoptReason reason) {
3739   ciMethodData* md = method->method_data();
3740   if (md->is_empty()) {
3741     // Assume the trap has not occurred, or that it occurred only
3742     // because of a transient condition during start-up in the interpreter.
3743     return false;
3744   }
3745   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
3746   if (md->has_trap_at(bci, m, reason) != 0) {
3747     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
3748     // Also, if there are multiple reasons, or if there is no per-BCI record,
3749     // assume the worst.
3750     if (log())
3751       log()->elem("observe trap='%s' count='%d'",
3752                   Deoptimization::trap_reason_name(reason),
3753                   md->trap_count(reason));
3754     return true;
3755   } else {
3756     // Ignore method/bci and see if there have been too many globally.
3757     return too_many_traps(reason, md);
3758   }
3759 }
3760 
3761 // Less-accurate variant which does not require a method and bci.
3762 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
3763                              ciMethodData* logmd) {
3764   if (trap_count(reason) >= Deoptimization::per_method_trap_limit(reason)) {
3765     // Too many traps globally.
3766     // Note that we use cumulative trap_count, not just md->trap_count.
3767     if (log()) {
3768       int mcount = (logmd == NULL)? -1: (int)logmd->trap_count(reason);
3769       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
3770                   Deoptimization::trap_reason_name(reason),
3771                   mcount, trap_count(reason));
3772     }
3773     return true;
3774   } else {
3775     // The coast is clear.
3776     return false;
3777   }
3778 }
3779 
3780 //--------------------------too_many_recompiles--------------------------------
3781 // Report if there are too many recompiles at the current method and bci.
3782 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
3783 // Is not eager to return true, since this will cause the compiler to use
3784 // Action_none for a trap point, to avoid too many recompilations.
3785 bool Compile::too_many_recompiles(ciMethod* method,
3786                                   int bci,
3787                                   Deoptimization::DeoptReason reason) {
3788   ciMethodData* md = method->method_data();
3789   if (md->is_empty()) {
3790     // Assume the trap has not occurred, or that it occurred only
3791     // because of a transient condition during start-up in the interpreter.
3792     return false;
3793   }
3794   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
3795   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
3796   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
3797   Deoptimization::DeoptReason per_bc_reason
3798     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
3799   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
3800   if ((per_bc_reason == Deoptimization::Reason_none
3801        || md->has_trap_at(bci, m, reason) != 0)
3802       // The trap frequency measure we care about is the recompile count:
3803       && md->trap_recompiled_at(bci, m)
3804       && md->overflow_recompile_count() >= bc_cutoff) {
3805     // Do not emit a trap here if it has already caused recompilations.
3806     // Also, if there are multiple reasons, or if there is no per-BCI record,
3807     // assume the worst.
3808     if (log())
3809       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
3810                   Deoptimization::trap_reason_name(reason),
3811                   md->trap_count(reason),
3812                   md->overflow_recompile_count());
3813     return true;
3814   } else if (trap_count(reason) != 0
3815              && decompile_count() >= m_cutoff) {
3816     // Too many recompiles globally, and we have seen this sort of trap.
3817     // Use cumulative decompile_count, not just md->decompile_count.
3818     if (log())
3819       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
3820                   Deoptimization::trap_reason_name(reason),
3821                   md->trap_count(reason), trap_count(reason),
3822                   md->decompile_count(), decompile_count());
3823     return true;
3824   } else {
3825     // The coast is clear.
3826     return false;
3827   }
3828 }
3829 
3830 // Compute when not to trap. Used by matching trap based nodes and
3831 // NullCheck optimization.
3832 void Compile::set_allowed_deopt_reasons() {
3833   _allowed_reasons = 0;
3834   if (is_method_compilation()) {
3835     for (int rs = (int)Deoptimization::Reason_none+1; rs < Compile::trapHistLength; rs++) {
3836       assert(rs < BitsPerInt, "recode bit map");
3837       if (!too_many_traps((Deoptimization::DeoptReason) rs)) {
3838         _allowed_reasons |= nth_bit(rs);
3839       }
3840     }
3841   }
3842 }
3843 
3844 bool Compile::is_compiling_clinit_for(ciKlass* k) {
3845   ciMethod* root = method(); // the root method of compilation
3846   return root->is_static_initializer() && root->holder() == k; // access in the context of clinit
3847 }
3848 
3849 #ifndef PRODUCT
3850 //------------------------------verify_graph_edges---------------------------
3851 // Walk the Graph and verify that there is a one-to-one correspondence
3852 // between Use-Def edges and Def-Use edges in the graph.
3853 void Compile::verify_graph_edges(bool no_dead_code) {
3854   if (VerifyGraphEdges) {
3855     ResourceArea *area = Thread::current()->resource_area();
3856     Unique_Node_List visited(area);
3857     // Call recursive graph walk to check edges
3858     _root->verify_edges(visited);
3859     if (no_dead_code) {
3860       // Now make sure that no visited node is used by an unvisited node.
3861       bool dead_nodes = false;
3862       Unique_Node_List checked(area);
3863       while (visited.size() > 0) {
3864         Node* n = visited.pop();
3865         checked.push(n);
3866         for (uint i = 0; i < n->outcnt(); i++) {
3867           Node* use = n->raw_out(i);
3868           if (checked.member(use))  continue;  // already checked
3869           if (visited.member(use))  continue;  // already in the graph
3870           if (use->is_Con())        continue;  // a dead ConNode is OK
3871           // At this point, we have found a dead node which is DU-reachable.
3872           if (!dead_nodes) {
3873             tty->print_cr("*** Dead nodes reachable via DU edges:");
3874             dead_nodes = true;
3875           }
3876           use->dump(2);
3877           tty->print_cr("---");
3878           checked.push(use);  // No repeats; pretend it is now checked.
3879         }
3880       }
3881       assert(!dead_nodes, "using nodes must be reachable from root");
3882     }
3883   }
3884 }
3885 #endif
3886 
3887 // The Compile object keeps track of failure reasons separately from the ciEnv.
3888 // This is required because there is not quite a 1-1 relation between the
3889 // ciEnv and its compilation task and the Compile object.  Note that one
3890 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
3891 // to backtrack and retry without subsuming loads.  Other than this backtracking
3892 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
3893 // by the logic in C2Compiler.
3894 void Compile::record_failure(const char* reason) {
3895   if (log() != NULL) {
3896     log()->elem("failure reason='%s' phase='compile'", reason);
3897   }
3898   if (_failure_reason == NULL) {
3899     // Record the first failure reason.
3900     _failure_reason = reason;
3901   }
3902 
3903   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
3904     C->print_method(PHASE_FAILURE);
3905   }
3906   _root = NULL;  // flush the graph, too
3907 }
3908 
3909 Compile::TracePhase::TracePhase(const char* name, elapsedTimer* accumulator)
3910   : TraceTime(name, accumulator, CITime, CITimeVerbose),
3911     _phase_name(name), _dolog(CITimeVerbose)
3912 {
3913   if (_dolog) {
3914     C = Compile::current();
3915     _log = C->log();
3916   } else {
3917     C = NULL;
3918     _log = NULL;
3919   }
3920   if (_log != NULL) {
3921     _log->begin_head("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
3922     _log->stamp();
3923     _log->end_head();
3924   }
3925 }
3926 
3927 Compile::TracePhase::~TracePhase() {
3928 
3929   C = Compile::current();
3930   if (_dolog) {
3931     _log = C->log();
3932   } else {
3933     _log = NULL;
3934   }
3935 
3936 #ifdef ASSERT
3937   if (PrintIdealNodeCount) {
3938     tty->print_cr("phase name='%s' nodes='%d' live='%d' live_graph_walk='%d'",
3939                   _phase_name, C->unique(), C->live_nodes(), C->count_live_nodes_by_graph_walk());
3940   }
3941 
3942   if (VerifyIdealNodeCount) {
3943     Compile::current()->print_missing_nodes();
3944   }
3945 #endif
3946 
3947   if (_log != NULL) {
3948     _log->done("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
3949   }
3950 }
3951 
3952 //=============================================================================
3953 // Two Constant's are equal when the type and the value are equal.
3954 bool Compile::Constant::operator==(const Constant& other) {
3955   if (type()          != other.type()         )  return false;
3956   if (can_be_reused() != other.can_be_reused())  return false;
3957   // For floating point values we compare the bit pattern.
3958   switch (type()) {
3959   case T_INT:
3960   case T_FLOAT:   return (_v._value.i == other._v._value.i);
3961   case T_LONG:
3962   case T_DOUBLE:  return (_v._value.j == other._v._value.j);
3963   case T_OBJECT:
3964   case T_ADDRESS: return (_v._value.l == other._v._value.l);
3965   case T_VOID:    return (_v._value.l == other._v._value.l);  // jump-table entries
3966   case T_METADATA: return (_v._metadata == other._v._metadata);
3967   default: ShouldNotReachHere(); return false;
3968   }
3969 }
3970 
3971 static int type_to_size_in_bytes(BasicType t) {
3972   switch (t) {
3973   case T_INT:     return sizeof(jint   );
3974   case T_LONG:    return sizeof(jlong  );
3975   case T_FLOAT:   return sizeof(jfloat );
3976   case T_DOUBLE:  return sizeof(jdouble);
3977   case T_METADATA: return sizeof(Metadata*);
3978     // We use T_VOID as marker for jump-table entries (labels) which
3979     // need an internal word relocation.
3980   case T_VOID:
3981   case T_ADDRESS:
3982   case T_OBJECT:  return sizeof(jobject);
3983   default:
3984     ShouldNotReachHere();
3985     return -1;
3986   }
3987 }
3988 
3989 int Compile::ConstantTable::qsort_comparator(Constant* a, Constant* b) {
3990   // sort descending
3991   if (a->freq() > b->freq())  return -1;
3992   if (a->freq() < b->freq())  return  1;
3993   return 0;
3994 }
3995 
3996 void Compile::ConstantTable::calculate_offsets_and_size() {
3997   // First, sort the array by frequencies.
3998   _constants.sort(qsort_comparator);
3999 
4000 #ifdef ASSERT
4001   // Make sure all jump-table entries were sorted to the end of the
4002   // array (they have a negative frequency).
4003   bool found_void = false;
4004   for (int i = 0; i < _constants.length(); i++) {
4005     Constant con = _constants.at(i);
4006     if (con.type() == T_VOID)
4007       found_void = true;  // jump-tables
4008     else
4009       assert(!found_void, "wrong sorting");
4010   }
4011 #endif
4012 
4013   int offset = 0;
4014   for (int i = 0; i < _constants.length(); i++) {
4015     Constant* con = _constants.adr_at(i);
4016 
4017     // Align offset for type.
4018     int typesize = type_to_size_in_bytes(con->type());
4019     offset = align_up(offset, typesize);
4020     con->set_offset(offset);   // set constant's offset
4021 
4022     if (con->type() == T_VOID) {
4023       MachConstantNode* n = (MachConstantNode*) con->get_jobject();
4024       offset = offset + typesize * n->outcnt();  // expand jump-table
4025     } else {
4026       offset = offset + typesize;
4027     }
4028   }
4029 
4030   // Align size up to the next section start (which is insts; see
4031   // CodeBuffer::align_at_start).
4032   assert(_size == -1, "already set?");
4033   _size = align_up(offset, (int)CodeEntryAlignment);
4034 }
4035 
4036 void Compile::ConstantTable::emit(CodeBuffer& cb) {
4037   MacroAssembler _masm(&cb);
4038   for (int i = 0; i < _constants.length(); i++) {
4039     Constant con = _constants.at(i);
4040     address constant_addr = NULL;
4041     switch (con.type()) {
4042     case T_INT:    constant_addr = _masm.int_constant(   con.get_jint()   ); break;
4043     case T_LONG:   constant_addr = _masm.long_constant(  con.get_jlong()  ); break;
4044     case T_FLOAT:  constant_addr = _masm.float_constant( con.get_jfloat() ); break;
4045     case T_DOUBLE: constant_addr = _masm.double_constant(con.get_jdouble()); break;
4046     case T_OBJECT: {
4047       jobject obj = con.get_jobject();
4048       int oop_index = _masm.oop_recorder()->find_index(obj);
4049       constant_addr = _masm.address_constant((address) obj, oop_Relocation::spec(oop_index));
4050       break;
4051     }
4052     case T_ADDRESS: {
4053       address addr = (address) con.get_jobject();
4054       constant_addr = _masm.address_constant(addr);
4055       break;
4056     }
4057     // We use T_VOID as marker for jump-table entries (labels) which
4058     // need an internal word relocation.
4059     case T_VOID: {
4060       MachConstantNode* n = (MachConstantNode*) con.get_jobject();
4061       // Fill the jump-table with a dummy word.  The real value is
4062       // filled in later in fill_jump_table.
4063       address dummy = (address) n;
4064       constant_addr = _masm.address_constant(dummy);
4065       // Expand jump-table
4066       for (uint i = 1; i < n->outcnt(); i++) {
4067         address temp_addr = _masm.address_constant(dummy + i);
4068         assert(temp_addr, "consts section too small");
4069       }
4070       break;
4071     }
4072     case T_METADATA: {
4073       Metadata* obj = con.get_metadata();
4074       int metadata_index = _masm.oop_recorder()->find_index(obj);
4075       constant_addr = _masm.address_constant((address) obj, metadata_Relocation::spec(metadata_index));
4076       break;
4077     }
4078     default: ShouldNotReachHere();
4079     }
4080     assert(constant_addr, "consts section too small");
4081     assert((constant_addr - _masm.code()->consts()->start()) == con.offset(),
4082             "must be: %d == %d", (int) (constant_addr - _masm.code()->consts()->start()), (int)(con.offset()));
4083   }
4084 }
4085 
4086 int Compile::ConstantTable::find_offset(Constant& con) const {
4087   int idx = _constants.find(con);
4088   guarantee(idx != -1, "constant must be in constant table");
4089   int offset = _constants.at(idx).offset();
4090   guarantee(offset != -1, "constant table not emitted yet?");
4091   return offset;
4092 }
4093 
4094 void Compile::ConstantTable::add(Constant& con) {
4095   if (con.can_be_reused()) {
4096     int idx = _constants.find(con);
4097     if (idx != -1 && _constants.at(idx).can_be_reused()) {
4098       _constants.adr_at(idx)->inc_freq(con.freq());  // increase the frequency by the current value
4099       return;
4100     }
4101   }
4102   (void) _constants.append(con);
4103 }
4104 
4105 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, BasicType type, jvalue value) {
4106   Block* b = Compile::current()->cfg()->get_block_for_node(n);
4107   Constant con(type, value, b->_freq);
4108   add(con);
4109   return con;
4110 }
4111 
4112 Compile::Constant Compile::ConstantTable::add(Metadata* metadata) {
4113   Constant con(metadata);
4114   add(con);
4115   return con;
4116 }
4117 
4118 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, MachOper* oper) {
4119   jvalue value;
4120   BasicType type = oper->type()->basic_type();
4121   switch (type) {
4122   case T_LONG:    value.j = oper->constantL(); break;
4123   case T_FLOAT:   value.f = oper->constantF(); break;
4124   case T_DOUBLE:  value.d = oper->constantD(); break;
4125   case T_OBJECT:
4126   case T_ADDRESS: value.l = (jobject) oper->constant(); break;
4127   case T_METADATA: return add((Metadata*)oper->constant()); break;
4128   default: guarantee(false, "unhandled type: %s", type2name(type));
4129   }
4130   return add(n, type, value);
4131 }
4132 
4133 Compile::Constant Compile::ConstantTable::add_jump_table(MachConstantNode* n) {
4134   jvalue value;
4135   // We can use the node pointer here to identify the right jump-table
4136   // as this method is called from Compile::Fill_buffer right before
4137   // the MachNodes are emitted and the jump-table is filled (means the
4138   // MachNode pointers do not change anymore).
4139   value.l = (jobject) n;
4140   Constant con(T_VOID, value, next_jump_table_freq(), false);  // Labels of a jump-table cannot be reused.
4141   add(con);
4142   return con;
4143 }
4144 
4145 void Compile::ConstantTable::fill_jump_table(CodeBuffer& cb, MachConstantNode* n, GrowableArray<Label*> labels) const {
4146   // If called from Compile::scratch_emit_size do nothing.
4147   if (Compile::current()->in_scratch_emit_size())  return;
4148 
4149   assert(labels.is_nonempty(), "must be");
4150   assert((uint) labels.length() == n->outcnt(), "must be equal: %d == %d", labels.length(), n->outcnt());
4151 
4152   // Since MachConstantNode::constant_offset() also contains
4153   // table_base_offset() we need to subtract the table_base_offset()
4154   // to get the plain offset into the constant table.
4155   int offset = n->constant_offset() - table_base_offset();
4156 
4157   MacroAssembler _masm(&cb);
4158   address* jump_table_base = (address*) (_masm.code()->consts()->start() + offset);
4159 
4160   for (uint i = 0; i < n->outcnt(); i++) {
4161     address* constant_addr = &jump_table_base[i];
4162     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));
4163     *constant_addr = cb.consts()->target(*labels.at(i), (address) constant_addr);
4164     cb.consts()->relocate((address) constant_addr, relocInfo::internal_word_type);
4165   }
4166 }
4167 
4168 //----------------------------static_subtype_check-----------------------------
4169 // Shortcut important common cases when superklass is exact:
4170 // (0) superklass is java.lang.Object (can occur in reflective code)
4171 // (1) subklass is already limited to a subtype of superklass => always ok
4172 // (2) subklass does not overlap with superklass => always fail
4173 // (3) superklass has NO subtypes and we can check with a simple compare.
4174 int Compile::static_subtype_check(ciKlass* superk, ciKlass* subk) {
4175   if (StressReflectiveCode) {
4176     return SSC_full_test;       // Let caller generate the general case.
4177   }
4178 
4179   if (superk == env()->Object_klass()) {
4180     return SSC_always_true;     // (0) this test cannot fail
4181   }
4182 
4183   ciType* superelem = superk;
4184   if (superelem->is_array_klass())
4185     superelem = superelem->as_array_klass()->base_element_type();
4186 
4187   if (!subk->is_interface()) {  // cannot trust static interface types yet
4188     if (subk->is_subtype_of(superk)) {
4189       return SSC_always_true;   // (1) false path dead; no dynamic test needed
4190     }
4191     if (!(superelem->is_klass() && superelem->as_klass()->is_interface()) &&
4192         !superk->is_subtype_of(subk)) {
4193       return SSC_always_false;
4194     }
4195   }
4196 
4197   // If casting to an instance klass, it must have no subtypes
4198   if (superk->is_interface()) {
4199     // Cannot trust interfaces yet.
4200     // %%% S.B. superk->nof_implementors() == 1
4201   } else if (superelem->is_instance_klass()) {
4202     ciInstanceKlass* ik = superelem->as_instance_klass();
4203     if (!ik->has_subklass() && !ik->is_interface()) {
4204       if (!ik->is_final()) {
4205         // Add a dependency if there is a chance of a later subclass.
4206         dependencies()->assert_leaf_type(ik);
4207       }
4208       return SSC_easy_test;     // (3) caller can do a simple ptr comparison
4209     }
4210   } else {
4211     // A primitive array type has no subtypes.
4212     return SSC_easy_test;       // (3) caller can do a simple ptr comparison
4213   }
4214 
4215   return SSC_full_test;
4216 }
4217 
4218 Node* Compile::conv_I2X_index(PhaseGVN* phase, Node* idx, const TypeInt* sizetype, Node* ctrl) {
4219 #ifdef _LP64
4220   // The scaled index operand to AddP must be a clean 64-bit value.
4221   // Java allows a 32-bit int to be incremented to a negative
4222   // value, which appears in a 64-bit register as a large
4223   // positive number.  Using that large positive number as an
4224   // operand in pointer arithmetic has bad consequences.
4225   // On the other hand, 32-bit overflow is rare, and the possibility
4226   // can often be excluded, if we annotate the ConvI2L node with
4227   // a type assertion that its value is known to be a small positive
4228   // number.  (The prior range check has ensured this.)
4229   // This assertion is used by ConvI2LNode::Ideal.
4230   int index_max = max_jint - 1;  // array size is max_jint, index is one less
4231   if (sizetype != NULL) index_max = sizetype->_hi - 1;
4232   const TypeInt* iidxtype = TypeInt::make(0, index_max, Type::WidenMax);
4233   idx = constrained_convI2L(phase, idx, iidxtype, ctrl);
4234 #endif
4235   return idx;
4236 }
4237 
4238 // Convert integer value to a narrowed long type dependent on ctrl (for example, a range check)
4239 Node* Compile::constrained_convI2L(PhaseGVN* phase, Node* value, const TypeInt* itype, Node* ctrl) {
4240   if (ctrl != NULL) {
4241     // Express control dependency by a CastII node with a narrow type.
4242     value = new CastIINode(value, itype, false, true /* range check dependency */);
4243     // Make the CastII node dependent on the control input to prevent the narrowed ConvI2L
4244     // node from floating above the range check during loop optimizations. Otherwise, the
4245     // ConvI2L node may be eliminated independently of the range check, causing the data path
4246     // to become TOP while the control path is still there (although it's unreachable).
4247     value->set_req(0, ctrl);
4248     // Save CastII node to remove it after loop optimizations.
4249     phase->C->add_range_check_cast(value);
4250     value = phase->transform(value);
4251   }
4252   const TypeLong* ltype = TypeLong::make(itype->_lo, itype->_hi, itype->_widen);
4253   return phase->transform(new ConvI2LNode(value, ltype));
4254 }
4255 
4256 // The message about the current inlining is accumulated in
4257 // _print_inlining_stream and transfered into the _print_inlining_list
4258 // once we know whether inlining succeeds or not. For regular
4259 // inlining, messages are appended to the buffer pointed by
4260 // _print_inlining_idx in the _print_inlining_list. For late inlining,
4261 // a new buffer is added after _print_inlining_idx in the list. This
4262 // way we can update the inlining message for late inlining call site
4263 // when the inlining is attempted again.
4264 void Compile::print_inlining_init() {
4265   if (print_inlining() || print_intrinsics()) {
4266     _print_inlining_stream = new stringStream();
4267     _print_inlining_list = new (comp_arena())GrowableArray<PrintInliningBuffer>(comp_arena(), 1, 1, PrintInliningBuffer());
4268   }
4269 }
4270 
4271 void Compile::print_inlining_reinit() {
4272   if (print_inlining() || print_intrinsics()) {
4273     // Re allocate buffer when we change ResourceMark
4274     _print_inlining_stream = new stringStream();
4275   }
4276 }
4277 
4278 void Compile::print_inlining_reset() {
4279   _print_inlining_stream->reset();
4280 }
4281 
4282 void Compile::print_inlining_commit() {
4283   assert(print_inlining() || print_intrinsics(), "PrintInlining off?");
4284   // Transfer the message from _print_inlining_stream to the current
4285   // _print_inlining_list buffer and clear _print_inlining_stream.
4286   _print_inlining_list->at(_print_inlining_idx).ss()->write(_print_inlining_stream->as_string(), _print_inlining_stream->size());
4287   print_inlining_reset();
4288 }
4289 
4290 void Compile::print_inlining_push() {
4291   // Add new buffer to the _print_inlining_list at current position
4292   _print_inlining_idx++;
4293   _print_inlining_list->insert_before(_print_inlining_idx, PrintInliningBuffer());
4294 }
4295 
4296 Compile::PrintInliningBuffer& Compile::print_inlining_current() {
4297   return _print_inlining_list->at(_print_inlining_idx);
4298 }
4299 
4300 void Compile::print_inlining_update(CallGenerator* cg) {
4301   if (print_inlining() || print_intrinsics()) {
4302     if (!cg->is_late_inline()) {
4303       if (print_inlining_current().cg() != NULL) {
4304         print_inlining_push();
4305       }
4306       print_inlining_commit();
4307     } else {
4308       if (print_inlining_current().cg() != cg &&
4309           (print_inlining_current().cg() != NULL ||
4310            print_inlining_current().ss()->size() != 0)) {
4311         print_inlining_push();
4312       }
4313       print_inlining_commit();
4314       print_inlining_current().set_cg(cg);
4315     }
4316   }
4317 }
4318 
4319 void Compile::print_inlining_move_to(CallGenerator* cg) {
4320   // We resume inlining at a late inlining call site. Locate the
4321   // corresponding inlining buffer so that we can update it.
4322   if (print_inlining()) {
4323     for (int i = 0; i < _print_inlining_list->length(); i++) {
4324       if (_print_inlining_list->adr_at(i)->cg() == cg) {
4325         _print_inlining_idx = i;
4326         return;
4327       }
4328     }
4329     ShouldNotReachHere();
4330   }
4331 }
4332 
4333 void Compile::print_inlining_update_delayed(CallGenerator* cg) {
4334   if (print_inlining()) {
4335     assert(_print_inlining_stream->size() > 0, "missing inlining msg");
4336     assert(print_inlining_current().cg() == cg, "wrong entry");
4337     // replace message with new message
4338     _print_inlining_list->at_put(_print_inlining_idx, PrintInliningBuffer());
4339     print_inlining_commit();
4340     print_inlining_current().set_cg(cg);
4341   }
4342 }
4343 
4344 void Compile::print_inlining_assert_ready() {
4345   assert(!_print_inlining || _print_inlining_stream->size() == 0, "loosing data");
4346 }
4347 
4348 void Compile::process_print_inlining() {
4349   bool do_print_inlining = print_inlining() || print_intrinsics();
4350   if (do_print_inlining || log() != NULL) {
4351     // Print inlining message for candidates that we couldn't inline
4352     // for lack of space
4353     for (int i = 0; i < _late_inlines.length(); i++) {
4354       CallGenerator* cg = _late_inlines.at(i);
4355       if (!cg->is_mh_late_inline()) {
4356         const char* msg = "live nodes > LiveNodeCountInliningCutoff";
4357         if (do_print_inlining) {
4358           cg->print_inlining_late(msg);
4359         }
4360         log_late_inline_failure(cg, msg);
4361       }
4362     }
4363   }
4364   if (do_print_inlining) {
4365     ResourceMark rm;
4366     stringStream ss;
4367     for (int i = 0; i < _print_inlining_list->length(); i++) {
4368       ss.print("%s", _print_inlining_list->adr_at(i)->ss()->as_string());
4369     }
4370     size_t end = ss.size();
4371     _print_inlining_output = NEW_ARENA_ARRAY(comp_arena(), char, end+1);
4372     strncpy(_print_inlining_output, ss.base(), end+1);
4373     _print_inlining_output[end] = 0;
4374   }
4375 }
4376 
4377 void Compile::dump_print_inlining() {
4378   if (_print_inlining_output != NULL) {
4379     tty->print_raw(_print_inlining_output);
4380   }
4381 }
4382 
4383 void Compile::log_late_inline(CallGenerator* cg) {
4384   if (log() != NULL) {
4385     log()->head("late_inline method='%d'  inline_id='" JLONG_FORMAT "'", log()->identify(cg->method()),
4386                 cg->unique_id());
4387     JVMState* p = cg->call_node()->jvms();
4388     while (p != NULL) {
4389       log()->elem("jvms bci='%d' method='%d'", p->bci(), log()->identify(p->method()));
4390       p = p->caller();
4391     }
4392     log()->tail("late_inline");
4393   }
4394 }
4395 
4396 void Compile::log_late_inline_failure(CallGenerator* cg, const char* msg) {
4397   log_late_inline(cg);
4398   if (log() != NULL) {
4399     log()->inline_fail(msg);
4400   }
4401 }
4402 
4403 void Compile::log_inline_id(CallGenerator* cg) {
4404   if (log() != NULL) {
4405     // The LogCompilation tool needs a unique way to identify late
4406     // inline call sites. This id must be unique for this call site in
4407     // this compilation. Try to have it unique across compilations as
4408     // well because it can be convenient when grepping through the log
4409     // file.
4410     // Distinguish OSR compilations from others in case CICountOSR is
4411     // on.
4412     jlong id = ((jlong)unique()) + (((jlong)compile_id()) << 33) + (CICountOSR && is_osr_compilation() ? ((jlong)1) << 32 : 0);
4413     cg->set_unique_id(id);
4414     log()->elem("inline_id id='" JLONG_FORMAT "'", id);
4415   }
4416 }
4417 
4418 void Compile::log_inline_failure(const char* msg) {
4419   if (C->log() != NULL) {
4420     C->log()->inline_fail(msg);
4421   }
4422 }
4423 
4424 
4425 // Dump inlining replay data to the stream.
4426 // Don't change thread state and acquire any locks.
4427 void Compile::dump_inline_data(outputStream* out) {
4428   InlineTree* inl_tree = ilt();
4429   if (inl_tree != NULL) {
4430     out->print(" inline %d", inl_tree->count());
4431     inl_tree->dump_replay_data(out);
4432   }
4433 }
4434 
4435 int Compile::cmp_expensive_nodes(Node* n1, Node* n2) {
4436   if (n1->Opcode() < n2->Opcode())      return -1;
4437   else if (n1->Opcode() > n2->Opcode()) return 1;
4438 
4439   assert(n1->req() == n2->req(), "can't compare %s nodes: n1->req() = %d, n2->req() = %d", NodeClassNames[n1->Opcode()], n1->req(), n2->req());
4440   for (uint i = 1; i < n1->req(); i++) {
4441     if (n1->in(i) < n2->in(i))      return -1;
4442     else if (n1->in(i) > n2->in(i)) return 1;
4443   }
4444 
4445   return 0;
4446 }
4447 
4448 int Compile::cmp_expensive_nodes(Node** n1p, Node** n2p) {
4449   Node* n1 = *n1p;
4450   Node* n2 = *n2p;
4451 
4452   return cmp_expensive_nodes(n1, n2);
4453 }
4454 
4455 void Compile::sort_expensive_nodes() {
4456   if (!expensive_nodes_sorted()) {
4457     _expensive_nodes->sort(cmp_expensive_nodes);
4458   }
4459 }
4460 
4461 bool Compile::expensive_nodes_sorted() const {
4462   for (int i = 1; i < _expensive_nodes->length(); i++) {
4463     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i-1)) < 0) {
4464       return false;
4465     }
4466   }
4467   return true;
4468 }
4469 
4470 bool Compile::should_optimize_expensive_nodes(PhaseIterGVN &igvn) {
4471   if (_expensive_nodes->length() == 0) {
4472     return false;
4473   }
4474 
4475   assert(OptimizeExpensiveOps, "optimization off?");
4476 
4477   // Take this opportunity to remove dead nodes from the list
4478   int j = 0;
4479   for (int i = 0; i < _expensive_nodes->length(); i++) {
4480     Node* n = _expensive_nodes->at(i);
4481     if (!n->is_unreachable(igvn)) {
4482       assert(n->is_expensive(), "should be expensive");
4483       _expensive_nodes->at_put(j, n);
4484       j++;
4485     }
4486   }
4487   _expensive_nodes->trunc_to(j);
4488 
4489   // Then sort the list so that similar nodes are next to each other
4490   // and check for at least two nodes of identical kind with same data
4491   // inputs.
4492   sort_expensive_nodes();
4493 
4494   for (int i = 0; i < _expensive_nodes->length()-1; i++) {
4495     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i+1)) == 0) {
4496       return true;
4497     }
4498   }
4499 
4500   return false;
4501 }
4502 
4503 void Compile::cleanup_expensive_nodes(PhaseIterGVN &igvn) {
4504   if (_expensive_nodes->length() == 0) {
4505     return;
4506   }
4507 
4508   assert(OptimizeExpensiveOps, "optimization off?");
4509 
4510   // Sort to bring similar nodes next to each other and clear the
4511   // control input of nodes for which there's only a single copy.
4512   sort_expensive_nodes();
4513 
4514   int j = 0;
4515   int identical = 0;
4516   int i = 0;
4517   bool modified = false;
4518   for (; i < _expensive_nodes->length()-1; i++) {
4519     assert(j <= i, "can't write beyond current index");
4520     if (_expensive_nodes->at(i)->Opcode() == _expensive_nodes->at(i+1)->Opcode()) {
4521       identical++;
4522       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4523       continue;
4524     }
4525     if (identical > 0) {
4526       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4527       identical = 0;
4528     } else {
4529       Node* n = _expensive_nodes->at(i);
4530       igvn.replace_input_of(n, 0, NULL);
4531       igvn.hash_insert(n);
4532       modified = true;
4533     }
4534   }
4535   if (identical > 0) {
4536     _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4537   } else if (_expensive_nodes->length() >= 1) {
4538     Node* n = _expensive_nodes->at(i);
4539     igvn.replace_input_of(n, 0, NULL);
4540     igvn.hash_insert(n);
4541     modified = true;
4542   }
4543   _expensive_nodes->trunc_to(j);
4544   if (modified) {
4545     igvn.optimize();
4546   }
4547 }
4548 
4549 void Compile::add_expensive_node(Node * n) {
4550   assert(!_expensive_nodes->contains(n), "duplicate entry in expensive list");
4551   assert(n->is_expensive(), "expensive nodes with non-null control here only");
4552   assert(!n->is_CFG() && !n->is_Mem(), "no cfg or memory nodes here");
4553   if (OptimizeExpensiveOps) {
4554     _expensive_nodes->append(n);
4555   } else {
4556     // Clear control input and let IGVN optimize expensive nodes if
4557     // OptimizeExpensiveOps is off.
4558     n->set_req(0, NULL);
4559   }
4560 }
4561 
4562 /**
4563  * Remove the speculative part of types and clean up the graph
4564  */
4565 void Compile::remove_speculative_types(PhaseIterGVN &igvn) {
4566   if (UseTypeSpeculation) {
4567     Unique_Node_List worklist;
4568     worklist.push(root());
4569     int modified = 0;
4570     // Go over all type nodes that carry a speculative type, drop the
4571     // speculative part of the type and enqueue the node for an igvn
4572     // which may optimize it out.
4573     for (uint next = 0; next < worklist.size(); ++next) {
4574       Node *n  = worklist.at(next);
4575       if (n->is_Type()) {
4576         TypeNode* tn = n->as_Type();
4577         const Type* t = tn->type();
4578         const Type* t_no_spec = t->remove_speculative();
4579         if (t_no_spec != t) {
4580           bool in_hash = igvn.hash_delete(n);
4581           assert(in_hash, "node should be in igvn hash table");
4582           tn->set_type(t_no_spec);
4583           igvn.hash_insert(n);
4584           igvn._worklist.push(n); // give it a chance to go away
4585           modified++;
4586         }
4587       }
4588       uint max = n->len();
4589       for( uint i = 0; i < max; ++i ) {
4590         Node *m = n->in(i);
4591         if (not_a_node(m))  continue;
4592         worklist.push(m);
4593       }
4594     }
4595     // Drop the speculative part of all types in the igvn's type table
4596     igvn.remove_speculative_types();
4597     if (modified > 0) {
4598       igvn.optimize();
4599     }
4600 #ifdef ASSERT
4601     // Verify that after the IGVN is over no speculative type has resurfaced
4602     worklist.clear();
4603     worklist.push(root());
4604     for (uint next = 0; next < worklist.size(); ++next) {
4605       Node *n  = worklist.at(next);
4606       const Type* t = igvn.type_or_null(n);
4607       assert((t == NULL) || (t == t->remove_speculative()), "no more speculative types");
4608       if (n->is_Type()) {
4609         t = n->as_Type()->type();
4610         assert(t == t->remove_speculative(), "no more speculative types");
4611       }
4612       uint max = n->len();
4613       for( uint i = 0; i < max; ++i ) {
4614         Node *m = n->in(i);
4615         if (not_a_node(m))  continue;
4616         worklist.push(m);
4617       }
4618     }
4619     igvn.check_no_speculative_types();
4620 #endif
4621   }
4622 }
4623 
4624 // Auxiliary method to support randomized stressing/fuzzing.
4625 //
4626 // This method can be called the arbitrary number of times, with current count
4627 // as the argument. The logic allows selecting a single candidate from the
4628 // running list of candidates as follows:
4629 //    int count = 0;
4630 //    Cand* selected = null;
4631 //    while(cand = cand->next()) {
4632 //      if (randomized_select(++count)) {
4633 //        selected = cand;
4634 //      }
4635 //    }
4636 //
4637 // Including count equalizes the chances any candidate is "selected".
4638 // This is useful when we don't have the complete list of candidates to choose
4639 // from uniformly. In this case, we need to adjust the randomicity of the
4640 // selection, or else we will end up biasing the selection towards the latter
4641 // candidates.
4642 //
4643 // Quick back-envelope calculation shows that for the list of n candidates
4644 // the equal probability for the candidate to persist as "best" can be
4645 // achieved by replacing it with "next" k-th candidate with the probability
4646 // of 1/k. It can be easily shown that by the end of the run, the
4647 // probability for any candidate is converged to 1/n, thus giving the
4648 // uniform distribution among all the candidates.
4649 //
4650 // We don't care about the domain size as long as (RANDOMIZED_DOMAIN / count) is large.
4651 #define RANDOMIZED_DOMAIN_POW 29
4652 #define RANDOMIZED_DOMAIN (1 << RANDOMIZED_DOMAIN_POW)
4653 #define RANDOMIZED_DOMAIN_MASK ((1 << (RANDOMIZED_DOMAIN_POW + 1)) - 1)
4654 bool Compile::randomized_select(int count) {
4655   assert(count > 0, "only positive");
4656   return (os::random() & RANDOMIZED_DOMAIN_MASK) < (RANDOMIZED_DOMAIN / count);
4657 }
4658 
4659 CloneMap&     Compile::clone_map()                 { return _clone_map; }
4660 void          Compile::set_clone_map(Dict* d)      { _clone_map._dict = d; }
4661 
4662 void NodeCloneInfo::dump() const {
4663   tty->print(" {%d:%d} ", idx(), gen());
4664 }
4665 
4666 void CloneMap::clone(Node* old, Node* nnn, int gen) {
4667   uint64_t val = value(old->_idx);
4668   NodeCloneInfo cio(val);
4669   assert(val != 0, "old node should be in the map");
4670   NodeCloneInfo cin(cio.idx(), gen + cio.gen());
4671   insert(nnn->_idx, cin.get());
4672 #ifndef PRODUCT
4673   if (is_debug()) {
4674     tty->print_cr("CloneMap::clone inserted node %d info {%d:%d} into CloneMap", nnn->_idx, cin.idx(), cin.gen());
4675   }
4676 #endif
4677 }
4678 
4679 void CloneMap::verify_insert_and_clone(Node* old, Node* nnn, int gen) {
4680   NodeCloneInfo cio(value(old->_idx));
4681   if (cio.get() == 0) {
4682     cio.set(old->_idx, 0);
4683     insert(old->_idx, cio.get());
4684 #ifndef PRODUCT
4685     if (is_debug()) {
4686       tty->print_cr("CloneMap::verify_insert_and_clone inserted node %d info {%d:%d} into CloneMap", old->_idx, cio.idx(), cio.gen());
4687     }
4688 #endif
4689   }
4690   clone(old, nnn, gen);
4691 }
4692 
4693 int CloneMap::max_gen() const {
4694   int g = 0;
4695   DictI di(_dict);
4696   for(; di.test(); ++di) {
4697     int t = gen(di._key);
4698     if (g < t) {
4699       g = t;
4700 #ifndef PRODUCT
4701       if (is_debug()) {
4702         tty->print_cr("CloneMap::max_gen() update max=%d from %d", g, _2_node_idx_t(di._key));
4703       }
4704 #endif
4705     }
4706   }
4707   return g;
4708 }
4709 
4710 void CloneMap::dump(node_idx_t key) const {
4711   uint64_t val = value(key);
4712   if (val != 0) {
4713     NodeCloneInfo ni(val);
4714     ni.dump();
4715   }
4716 }