1 /*
   2  * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "asm/macroAssembler.hpp"
  27 #include "asm/macroAssembler.inline.hpp"
  28 #include "ci/ciReplay.hpp"
  29 #include "classfile/systemDictionary.hpp"
  30 #include "code/exceptionHandlerTable.hpp"
  31 #include "code/nmethod.hpp"
  32 #include "compiler/compileBroker.hpp"
  33 #include "compiler/compileLog.hpp"
  34 #include "compiler/disassembler.hpp"
  35 #include "compiler/oopMap.hpp"
  36 #include "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                   _has_reserved_stack_access(target->has_reserved_stack_access()),
 652 #ifndef PRODUCT
 653                   _trace_opto_output(directive->TraceOptoOutputOption),
 654 #endif
 655                   _has_method_handle_invokes(false),
 656                   _comp_arena(mtCompiler),
 657                   _barrier_set_state(BarrierSet::barrier_set()->barrier_set_c2()->create_barrier_state(comp_arena())),
 658                   _env(ci_env),
 659                   _directive(directive),
 660                   _log(ci_env->log()),
 661                   _failure_reason(NULL),
 662                   _congraph(NULL),
 663 #ifndef PRODUCT
 664                   _printer(IdealGraphPrinter::printer()),
 665 #endif
 666                   _dead_node_list(comp_arena()),
 667                   _dead_node_count(0),
 668                   _node_arena(mtCompiler),
 669                   _old_arena(mtCompiler),
 670                   _mach_constant_base_node(NULL),
 671                   _Compile_types(mtCompiler),
 672                   _initial_gvn(NULL),
 673                   _for_igvn(NULL),
 674                   _warm_calls(NULL),
 675                   _late_inlines(comp_arena(), 2, 0, NULL),
 676                   _string_late_inlines(comp_arena(), 2, 0, NULL),
 677                   _boxing_late_inlines(comp_arena(), 2, 0, NULL),
 678                   _late_inlines_pos(0),
 679                   _number_of_mh_late_inlines(0),
 680                   _print_inlining_stream(NULL),
 681                   _print_inlining_list(NULL),
 682                   _print_inlining_idx(0),
 683                   _print_inlining_output(NULL),
 684                   _replay_inline_data(NULL),
 685                   _java_calls(0),
 686                   _inner_loops(0),
 687                   _interpreter_frame_size(0),
 688                   _node_bundling_limit(0),
 689                   _node_bundling_base(NULL),
 690                   _code_buffer("Compile::Fill_buffer"),
 691                   _scratch_const_size(-1),
 692                   _in_scratch_emit_size(false)
 693 #ifndef PRODUCT
 694                   , _in_dump_cnt(0)
 695 #endif
 696 {
 697   C = this;
 698 #ifndef PRODUCT
 699   if (_printer != NULL) {
 700     _printer->set_compile(this);
 701   }
 702 #endif
 703   CompileWrapper cw(this);
 704 
 705   if (CITimeVerbose) {
 706     tty->print(" ");
 707     target->holder()->name()->print();
 708     tty->print(".");
 709     target->print_short_name();
 710     tty->print("  ");
 711   }
 712   TraceTime t1("Total compilation time", &_t_totalCompilation, CITime, CITimeVerbose);
 713   TraceTime t2(NULL, &_t_methodCompilation, CITime, false);
 714 
 715 #ifndef PRODUCT
 716   bool print_opto_assembly = directive->PrintOptoAssemblyOption;
 717   if (!print_opto_assembly) {
 718     bool print_assembly = directive->PrintAssemblyOption;
 719     if (print_assembly && !Disassembler::can_decode()) {
 720       tty->print_cr("PrintAssembly request changed to PrintOptoAssembly");
 721       print_opto_assembly = true;
 722     }
 723   }
 724   set_print_assembly(print_opto_assembly);
 725   set_parsed_irreducible_loop(false);
 726 
 727   if (directive->ReplayInlineOption) {
 728     _replay_inline_data = ciReplay::load_inline_data(method(), entry_bci(), ci_env->comp_level());
 729   }
 730 #endif
 731   set_print_inlining(directive->PrintInliningOption || PrintOptoInlining);
 732   set_print_intrinsics(directive->PrintIntrinsicsOption);
 733   set_has_irreducible_loop(true); // conservative until build_loop_tree() reset it
 734 
 735   if (ProfileTraps RTM_OPT_ONLY( || UseRTMLocking )) {
 736     // Make sure the method being compiled gets its own MDO,
 737     // so we can at least track the decompile_count().
 738     // Need MDO to record RTM code generation state.
 739     method()->ensure_method_data();
 740   }
 741 
 742   Init(::AliasLevel);
 743 
 744 
 745   print_compile_messages();
 746 
 747   _ilt = InlineTree::build_inline_tree_root();
 748 
 749   // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
 750   assert(num_alias_types() >= AliasIdxRaw, "");
 751 
 752 #define MINIMUM_NODE_HASH  1023
 753   // Node list that Iterative GVN will start with
 754   Unique_Node_List for_igvn(comp_arena());
 755   set_for_igvn(&for_igvn);
 756 
 757   // GVN that will be run immediately on new nodes
 758   uint estimated_size = method()->code_size()*4+64;
 759   estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
 760   PhaseGVN gvn(node_arena(), estimated_size);
 761   set_initial_gvn(&gvn);
 762 
 763   print_inlining_init();
 764   { // Scope for timing the parser
 765     TracePhase tp("parse", &timers[_t_parser]);
 766 
 767     // Put top into the hash table ASAP.
 768     initial_gvn()->transform_no_reclaim(top());
 769 
 770     // Set up tf(), start(), and find a CallGenerator.
 771     CallGenerator* cg = NULL;
 772     if (is_osr_compilation()) {
 773       const TypeTuple *domain = StartOSRNode::osr_domain();
 774       const TypeTuple *range = TypeTuple::make_range(method()->signature());
 775       init_tf(TypeFunc::make(domain, range));
 776       StartNode* s = new StartOSRNode(root(), domain);
 777       initial_gvn()->set_type_bottom(s);
 778       init_start(s);
 779       cg = CallGenerator::for_osr(method(), entry_bci());
 780     } else {
 781       // Normal case.
 782       init_tf(TypeFunc::make(method()));
 783       StartNode* s = new StartNode(root(), tf()->domain());
 784       initial_gvn()->set_type_bottom(s);
 785       init_start(s);
 786       if (method()->intrinsic_id() == vmIntrinsics::_Reference_get) {
 787         // With java.lang.ref.reference.get() we must go through the
 788         // intrinsic - even when get() is the root
 789         // method of the compile - so that, if necessary, the value in
 790         // the referent field of the reference object gets recorded by
 791         // the pre-barrier code.
 792         cg = find_intrinsic(method(), false);
 793       }
 794       if (cg == NULL) {
 795         float past_uses = method()->interpreter_invocation_count();
 796         float expected_uses = past_uses;
 797         cg = CallGenerator::for_inline(method(), expected_uses);
 798       }
 799     }
 800     if (failing())  return;
 801     if (cg == NULL) {
 802       record_method_not_compilable("cannot parse method");
 803       return;
 804     }
 805     JVMState* jvms = build_start_state(start(), tf());
 806     if ((jvms = cg->generate(jvms)) == NULL) {
 807       if (!failure_reason_is(C2Compiler::retry_class_loading_during_parsing())) {
 808         record_method_not_compilable("method parse failed");
 809       }
 810       return;
 811     }
 812     GraphKit kit(jvms);
 813 
 814     if (!kit.stopped()) {
 815       // Accept return values, and transfer control we know not where.
 816       // This is done by a special, unique ReturnNode bound to root.
 817       return_values(kit.jvms());
 818     }
 819 
 820     if (kit.has_exceptions()) {
 821       // Any exceptions that escape from this call must be rethrown
 822       // to whatever caller is dynamically above us on the stack.
 823       // This is done by a special, unique RethrowNode bound to root.
 824       rethrow_exceptions(kit.transfer_exceptions_into_jvms());
 825     }
 826 
 827     assert(IncrementalInline || (_late_inlines.length() == 0 && !has_mh_late_inlines()), "incremental inlining is off");
 828 
 829     if (_late_inlines.length() == 0 && !has_mh_late_inlines() && !failing() && has_stringbuilder()) {
 830       inline_string_calls(true);
 831     }
 832 
 833     if (failing())  return;
 834 
 835     print_method(PHASE_BEFORE_REMOVEUSELESS, 3);
 836 
 837     // Remove clutter produced by parsing.
 838     if (!failing()) {
 839       ResourceMark rm;
 840       PhaseRemoveUseless pru(initial_gvn(), &for_igvn);
 841     }
 842   }
 843 
 844   // Note:  Large methods are capped off in do_one_bytecode().
 845   if (failing())  return;
 846 
 847   // After parsing, node notes are no longer automagic.
 848   // They must be propagated by register_new_node_with_optimizer(),
 849   // clone(), or the like.
 850   set_default_node_notes(NULL);
 851 
 852   for (;;) {
 853     int successes = Inline_Warm();
 854     if (failing())  return;
 855     if (successes == 0)  break;
 856   }
 857 
 858   // Drain the list.
 859   Finish_Warm();
 860 #ifndef PRODUCT
 861   if (_printer && _printer->should_print(1)) {
 862     _printer->print_inlining();
 863   }
 864 #endif
 865 
 866   if (failing())  return;
 867   NOT_PRODUCT( verify_graph_edges(); )
 868 
 869   // Now optimize
 870   Optimize();
 871   if (failing())  return;
 872   NOT_PRODUCT( verify_graph_edges(); )
 873 
 874 #ifndef PRODUCT
 875   if (PrintIdeal) {
 876     ttyLocker ttyl;  // keep the following output all in one block
 877     // This output goes directly to the tty, not the compiler log.
 878     // To enable tools to match it up with the compilation activity,
 879     // be sure to tag this tty output with the compile ID.
 880     if (xtty != NULL) {
 881       xtty->head("ideal compile_id='%d'%s", compile_id(),
 882                  is_osr_compilation()    ? " compile_kind='osr'" :
 883                  "");
 884     }
 885     root()->dump(9999);
 886     if (xtty != NULL) {
 887       xtty->tail("ideal");
 888     }
 889   }
 890 #endif
 891 
 892 #ifdef ASSERT
 893   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 894   bs->verify_gc_barriers(this, BarrierSetC2::BeforeCodeGen);
 895 #endif
 896 
 897   // Dump compilation data to replay it.
 898   if (directive->DumpReplayOption) {
 899     env()->dump_replay_data(_compile_id);
 900   }
 901   if (directive->DumpInlineOption && (ilt() != NULL)) {
 902     env()->dump_inline_data(_compile_id);
 903   }
 904 
 905   // Now that we know the size of all the monitors we can add a fixed slot
 906   // for the original deopt pc.
 907 
 908   _orig_pc_slot =  fixed_slots();
 909   int next_slot = _orig_pc_slot + (sizeof(address) / VMRegImpl::stack_slot_size);
 910   set_fixed_slots(next_slot);
 911 
 912   // Compute when to use implicit null checks. Used by matching trap based
 913   // nodes and NullCheck optimization.
 914   set_allowed_deopt_reasons();
 915 
 916   // Now generate code
 917   Code_Gen();
 918   if (failing())  return;
 919 
 920   // Check if we want to skip execution of all compiled code.
 921   {
 922 #ifndef PRODUCT
 923     if (OptoNoExecute) {
 924       record_method_not_compilable("+OptoNoExecute");  // Flag as failed
 925       return;
 926     }
 927 #endif
 928     TracePhase tp("install_code", &timers[_t_registerMethod]);
 929 
 930     if (is_osr_compilation()) {
 931       _code_offsets.set_value(CodeOffsets::Verified_Entry, 0);
 932       _code_offsets.set_value(CodeOffsets::OSR_Entry, _first_block_size);
 933     } else {
 934       _code_offsets.set_value(CodeOffsets::Verified_Entry, _first_block_size);
 935       _code_offsets.set_value(CodeOffsets::OSR_Entry, 0);
 936     }
 937 
 938     env()->register_method(_method, _entry_bci,
 939                            &_code_offsets,
 940                            _orig_pc_slot_offset_in_bytes,
 941                            code_buffer(),
 942                            frame_size_in_words(), _oop_map_set,
 943                            &_handler_table, &_inc_table,
 944                            compiler,
 945                            has_unsafe_access(),
 946                            SharedRuntime::is_wide_vector(max_vector_size()),
 947                            rtm_state()
 948                            );
 949 
 950     if (log() != NULL) // Print code cache state into compiler log
 951       log()->code_cache_state();
 952   }
 953 }
 954 
 955 //------------------------------Compile----------------------------------------
 956 // Compile a runtime stub
 957 Compile::Compile( ciEnv* ci_env,
 958                   TypeFunc_generator generator,
 959                   address stub_function,
 960                   const char *stub_name,
 961                   int is_fancy_jump,
 962                   bool pass_tls,
 963                   bool save_arg_registers,
 964                   bool return_pc,
 965                   DirectiveSet* directive)
 966   : Phase(Compiler),
 967     _compile_id(0),
 968     _save_argument_registers(save_arg_registers),
 969     _subsume_loads(true),
 970     _do_escape_analysis(false),
 971     _eliminate_boxing(false),
 972     _method(NULL),
 973     _entry_bci(InvocationEntryBci),
 974     _stub_function(stub_function),
 975     _stub_name(stub_name),
 976     _stub_entry_point(NULL),
 977     _max_node_limit(MaxNodeLimit),
 978     _orig_pc_slot(0),
 979     _orig_pc_slot_offset_in_bytes(0),
 980     _inlining_progress(false),
 981     _inlining_incrementally(false),
 982     _has_reserved_stack_access(false),
 983 #ifndef PRODUCT
 984     _trace_opto_output(directive->TraceOptoOutputOption),
 985 #endif
 986     _has_method_handle_invokes(false),
 987     _comp_arena(mtCompiler),
 988     _env(ci_env),
 989     _directive(directive),
 990     _log(ci_env->log()),
 991     _failure_reason(NULL),
 992     _congraph(NULL),
 993 #ifndef PRODUCT
 994     _printer(NULL),
 995 #endif
 996     _dead_node_list(comp_arena()),
 997     _dead_node_count(0),
 998     _node_arena(mtCompiler),
 999     _old_arena(mtCompiler),
1000     _mach_constant_base_node(NULL),
1001     _Compile_types(mtCompiler),
1002     _initial_gvn(NULL),
1003     _for_igvn(NULL),
1004     _warm_calls(NULL),
1005     _number_of_mh_late_inlines(0),
1006     _print_inlining_stream(NULL),
1007     _print_inlining_list(NULL),
1008     _print_inlining_idx(0),
1009     _print_inlining_output(NULL),
1010     _replay_inline_data(NULL),
1011     _java_calls(0),
1012     _inner_loops(0),
1013     _interpreter_frame_size(0),
1014     _node_bundling_limit(0),
1015     _node_bundling_base(NULL),
1016     _code_buffer("Compile::Fill_buffer"),
1017 #ifndef PRODUCT
1018     _in_dump_cnt(0),
1019 #endif
1020     _allowed_reasons(0) {
1021   C = this;
1022 
1023   TraceTime t1(NULL, &_t_totalCompilation, CITime, false);
1024   TraceTime t2(NULL, &_t_stubCompilation, CITime, false);
1025 
1026 #ifndef PRODUCT
1027   set_print_assembly(PrintFrameConverterAssembly);
1028   set_parsed_irreducible_loop(false);
1029 #endif
1030   set_has_irreducible_loop(false); // no loops
1031 
1032   CompileWrapper cw(this);
1033   Init(/*AliasLevel=*/ 0);
1034   init_tf((*generator)());
1035 
1036   {
1037     // The following is a dummy for the sake of GraphKit::gen_stub
1038     Unique_Node_List for_igvn(comp_arena());
1039     set_for_igvn(&for_igvn);  // not used, but some GraphKit guys push on this
1040     PhaseGVN gvn(Thread::current()->resource_area(),255);
1041     set_initial_gvn(&gvn);    // not significant, but GraphKit guys use it pervasively
1042     gvn.transform_no_reclaim(top());
1043 
1044     GraphKit kit;
1045     kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
1046   }
1047 
1048   NOT_PRODUCT( verify_graph_edges(); )
1049   Code_Gen();
1050   if (failing())  return;
1051 
1052 
1053   // Entry point will be accessed using compile->stub_entry_point();
1054   if (code_buffer() == NULL) {
1055     Matcher::soft_match_failure();
1056   } else {
1057     if (PrintAssembly && (WizardMode || Verbose))
1058       tty->print_cr("### Stub::%s", stub_name);
1059 
1060     if (!failing()) {
1061       assert(_fixed_slots == 0, "no fixed slots used for runtime stubs");
1062 
1063       // Make the NMethod
1064       // For now we mark the frame as never safe for profile stackwalking
1065       RuntimeStub *rs = RuntimeStub::new_runtime_stub(stub_name,
1066                                                       code_buffer(),
1067                                                       CodeOffsets::frame_never_safe,
1068                                                       // _code_offsets.value(CodeOffsets::Frame_Complete),
1069                                                       frame_size_in_words(),
1070                                                       _oop_map_set,
1071                                                       save_arg_registers);
1072       assert(rs != NULL && rs->is_runtime_stub(), "sanity check");
1073 
1074       _stub_entry_point = rs->entry_point();
1075     }
1076   }
1077 }
1078 
1079 //------------------------------Init-------------------------------------------
1080 // Prepare for a single compilation
1081 void Compile::Init(int aliaslevel) {
1082   _unique  = 0;
1083   _regalloc = NULL;
1084 
1085   _tf      = NULL;  // filled in later
1086   _top     = NULL;  // cached later
1087   _matcher = NULL;  // filled in later
1088   _cfg     = NULL;  // filled in later
1089 
1090   set_24_bit_selection_and_mode(Use24BitFP, false);
1091 
1092   _node_note_array = NULL;
1093   _default_node_notes = NULL;
1094   DEBUG_ONLY( _modified_nodes = NULL; ) // Used in Optimize()
1095 
1096   _immutable_memory = NULL; // filled in at first inquiry
1097 
1098   // Globally visible Nodes
1099   // First set TOP to NULL to give safe behavior during creation of RootNode
1100   set_cached_top_node(NULL);
1101   set_root(new RootNode());
1102   // Now that you have a Root to point to, create the real TOP
1103   set_cached_top_node( new ConNode(Type::TOP) );
1104   set_recent_alloc(NULL, NULL);
1105 
1106   // Create Debug Information Recorder to record scopes, oopmaps, etc.
1107   env()->set_oop_recorder(new OopRecorder(env()->arena()));
1108   env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
1109   env()->set_dependencies(new Dependencies(env()));
1110 
1111   _fixed_slots = 0;
1112   set_has_split_ifs(false);
1113   set_has_loops(has_method() && method()->has_loops()); // first approximation
1114   set_has_stringbuilder(false);
1115   set_has_boxed_value(false);
1116   _trap_can_recompile = false;  // no traps emitted yet
1117   _major_progress = true; // start out assuming good things will happen
1118   set_has_unsafe_access(false);
1119   set_max_vector_size(0);
1120   set_clear_upper_avx(false);  //false as default for clear upper bits of ymm registers
1121   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
1122   set_decompile_count(0);
1123 
1124   set_do_freq_based_layout(_directive->BlockLayoutByFrequencyOption);
1125   _loop_opts_cnt = LoopOptsCount;
1126   set_do_inlining(Inline);
1127   set_max_inline_size(MaxInlineSize);
1128   set_freq_inline_size(FreqInlineSize);
1129   set_do_scheduling(OptoScheduling);
1130   set_do_count_invocations(false);
1131   set_do_method_data_update(false);
1132 
1133   set_do_vector_loop(false);
1134 
1135   if (AllowVectorizeOnDemand) {
1136     if (has_method() && (_directive->VectorizeOption || _directive->VectorizeDebugOption)) {
1137       set_do_vector_loop(true);
1138       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());})
1139     } else if (has_method() && method()->name() != 0 &&
1140                method()->intrinsic_id() == vmIntrinsics::_forEachRemaining) {
1141       set_do_vector_loop(true);
1142     }
1143   }
1144   set_use_cmove(UseCMoveUnconditionally /* || do_vector_loop()*/); //TODO: consider do_vector_loop() mandate use_cmove unconditionally
1145   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());})
1146 
1147   set_age_code(has_method() && method()->profile_aging());
1148   set_rtm_state(NoRTM); // No RTM lock eliding by default
1149   _max_node_limit = _directive->MaxNodeLimitOption;
1150 
1151 #if INCLUDE_RTM_OPT
1152   if (UseRTMLocking && has_method() && (method()->method_data_or_null() != NULL)) {
1153     int rtm_state = method()->method_data()->rtm_state();
1154     if (method_has_option("NoRTMLockEliding") || ((rtm_state & NoRTM) != 0)) {
1155       // Don't generate RTM lock eliding code.
1156       set_rtm_state(NoRTM);
1157     } else if (method_has_option("UseRTMLockEliding") || ((rtm_state & UseRTM) != 0) || !UseRTMDeopt) {
1158       // Generate RTM lock eliding code without abort ratio calculation code.
1159       set_rtm_state(UseRTM);
1160     } else if (UseRTMDeopt) {
1161       // Generate RTM lock eliding code and include abort ratio calculation
1162       // code if UseRTMDeopt is on.
1163       set_rtm_state(ProfileRTM);
1164     }
1165   }
1166 #endif
1167   if (debug_info()->recording_non_safepoints()) {
1168     set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
1169                         (comp_arena(), 8, 0, NULL));
1170     set_default_node_notes(Node_Notes::make(this));
1171   }
1172 
1173   // // -- Initialize types before each compile --
1174   // // Update cached type information
1175   // if( _method && _method->constants() )
1176   //   Type::update_loaded_types(_method, _method->constants());
1177 
1178   // Init alias_type map.
1179   if (!_do_escape_analysis && aliaslevel == 3)
1180     aliaslevel = 2;  // No unique types without escape analysis
1181   _AliasLevel = aliaslevel;
1182   const int grow_ats = 16;
1183   _max_alias_types = grow_ats;
1184   _alias_types   = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
1185   AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType,  grow_ats);
1186   Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
1187   {
1188     for (int i = 0; i < grow_ats; i++)  _alias_types[i] = &ats[i];
1189   }
1190   // Initialize the first few types.
1191   _alias_types[AliasIdxTop]->Init(AliasIdxTop, NULL);
1192   _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
1193   _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
1194   _num_alias_types = AliasIdxRaw+1;
1195   // Zero out the alias type cache.
1196   Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
1197   // A NULL adr_type hits in the cache right away.  Preload the right answer.
1198   probe_alias_cache(NULL)->_index = AliasIdxTop;
1199 
1200   _intrinsics = NULL;
1201   _macro_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1202   _predicate_opaqs = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1203   _expensive_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1204   _range_check_casts = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1205   _opaque4_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1206   register_library_intrinsics();
1207 }
1208 
1209 //---------------------------init_start----------------------------------------
1210 // Install the StartNode on this compile object.
1211 void Compile::init_start(StartNode* s) {
1212   if (failing())
1213     return; // already failing
1214   assert(s == start(), "");
1215 }
1216 
1217 /**
1218  * Return the 'StartNode'. We must not have a pending failure, since the ideal graph
1219  * can be in an inconsistent state, i.e., we can get segmentation faults when traversing
1220  * the ideal graph.
1221  */
1222 StartNode* Compile::start() const {
1223   assert (!failing(), "Must not have pending failure. Reason is: %s", failure_reason());
1224   for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
1225     Node* start = root()->fast_out(i);
1226     if (start->is_Start()) {
1227       return start->as_Start();
1228     }
1229   }
1230   fatal("Did not find Start node!");
1231   return NULL;
1232 }
1233 
1234 //-------------------------------immutable_memory-------------------------------------
1235 // Access immutable memory
1236 Node* Compile::immutable_memory() {
1237   if (_immutable_memory != NULL) {
1238     return _immutable_memory;
1239   }
1240   StartNode* s = start();
1241   for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
1242     Node *p = s->fast_out(i);
1243     if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
1244       _immutable_memory = p;
1245       return _immutable_memory;
1246     }
1247   }
1248   ShouldNotReachHere();
1249   return NULL;
1250 }
1251 
1252 //----------------------set_cached_top_node------------------------------------
1253 // Install the cached top node, and make sure Node::is_top works correctly.
1254 void Compile::set_cached_top_node(Node* tn) {
1255   if (tn != NULL)  verify_top(tn);
1256   Node* old_top = _top;
1257   _top = tn;
1258   // Calling Node::setup_is_top allows the nodes the chance to adjust
1259   // their _out arrays.
1260   if (_top != NULL)     _top->setup_is_top();
1261   if (old_top != NULL)  old_top->setup_is_top();
1262   assert(_top == NULL || top()->is_top(), "");
1263 }
1264 
1265 #ifdef ASSERT
1266 uint Compile::count_live_nodes_by_graph_walk() {
1267   Unique_Node_List useful(comp_arena());
1268   // Get useful node list by walking the graph.
1269   identify_useful_nodes(useful);
1270   return useful.size();
1271 }
1272 
1273 void Compile::print_missing_nodes() {
1274 
1275   // Return if CompileLog is NULL and PrintIdealNodeCount is false.
1276   if ((_log == NULL) && (! PrintIdealNodeCount)) {
1277     return;
1278   }
1279 
1280   // This is an expensive function. It is executed only when the user
1281   // specifies VerifyIdealNodeCount option or otherwise knows the
1282   // additional work that needs to be done to identify reachable nodes
1283   // by walking the flow graph and find the missing ones using
1284   // _dead_node_list.
1285 
1286   Unique_Node_List useful(comp_arena());
1287   // Get useful node list by walking the graph.
1288   identify_useful_nodes(useful);
1289 
1290   uint l_nodes = C->live_nodes();
1291   uint l_nodes_by_walk = useful.size();
1292 
1293   if (l_nodes != l_nodes_by_walk) {
1294     if (_log != NULL) {
1295       _log->begin_head("mismatched_nodes count='%d'", abs((int) (l_nodes - l_nodes_by_walk)));
1296       _log->stamp();
1297       _log->end_head();
1298     }
1299     VectorSet& useful_member_set = useful.member_set();
1300     int last_idx = l_nodes_by_walk;
1301     for (int i = 0; i < last_idx; i++) {
1302       if (useful_member_set.test(i)) {
1303         if (_dead_node_list.test(i)) {
1304           if (_log != NULL) {
1305             _log->elem("mismatched_node_info node_idx='%d' type='both live and dead'", i);
1306           }
1307           if (PrintIdealNodeCount) {
1308             // Print the log message to tty
1309               tty->print_cr("mismatched_node idx='%d' both live and dead'", i);
1310               useful.at(i)->dump();
1311           }
1312         }
1313       }
1314       else if (! _dead_node_list.test(i)) {
1315         if (_log != NULL) {
1316           _log->elem("mismatched_node_info node_idx='%d' type='neither live nor dead'", i);
1317         }
1318         if (PrintIdealNodeCount) {
1319           // Print the log message to tty
1320           tty->print_cr("mismatched_node idx='%d' type='neither live nor dead'", i);
1321         }
1322       }
1323     }
1324     if (_log != NULL) {
1325       _log->tail("mismatched_nodes");
1326     }
1327   }
1328 }
1329 void Compile::record_modified_node(Node* n) {
1330   if (_modified_nodes != NULL && !_inlining_incrementally &&
1331       n->outcnt() != 0 && !n->is_Con()) {
1332     _modified_nodes->push(n);
1333   }
1334 }
1335 
1336 void Compile::remove_modified_node(Node* n) {
1337   if (_modified_nodes != NULL) {
1338     _modified_nodes->remove(n);
1339   }
1340 }
1341 #endif
1342 
1343 #ifndef PRODUCT
1344 void Compile::verify_top(Node* tn) const {
1345   if (tn != NULL) {
1346     assert(tn->is_Con(), "top node must be a constant");
1347     assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
1348     assert(tn->in(0) != NULL, "must have live top node");
1349   }
1350 }
1351 #endif
1352 
1353 
1354 ///-------------------Managing Per-Node Debug & Profile Info-------------------
1355 
1356 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
1357   guarantee(arr != NULL, "");
1358   int num_blocks = arr->length();
1359   if (grow_by < num_blocks)  grow_by = num_blocks;
1360   int num_notes = grow_by * _node_notes_block_size;
1361   Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
1362   Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
1363   while (num_notes > 0) {
1364     arr->append(notes);
1365     notes     += _node_notes_block_size;
1366     num_notes -= _node_notes_block_size;
1367   }
1368   assert(num_notes == 0, "exact multiple, please");
1369 }
1370 
1371 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
1372   if (source == NULL || dest == NULL)  return false;
1373 
1374   if (dest->is_Con())
1375     return false;               // Do not push debug info onto constants.
1376 
1377 #ifdef ASSERT
1378   // Leave a bread crumb trail pointing to the original node:
1379   if (dest != NULL && dest != source && dest->debug_orig() == NULL) {
1380     dest->set_debug_orig(source);
1381   }
1382 #endif
1383 
1384   if (node_note_array() == NULL)
1385     return false;               // Not collecting any notes now.
1386 
1387   // This is a copy onto a pre-existing node, which may already have notes.
1388   // If both nodes have notes, do not overwrite any pre-existing notes.
1389   Node_Notes* source_notes = node_notes_at(source->_idx);
1390   if (source_notes == NULL || source_notes->is_clear())  return false;
1391   Node_Notes* dest_notes   = node_notes_at(dest->_idx);
1392   if (dest_notes == NULL || dest_notes->is_clear()) {
1393     return set_node_notes_at(dest->_idx, source_notes);
1394   }
1395 
1396   Node_Notes merged_notes = (*source_notes);
1397   // The order of operations here ensures that dest notes will win...
1398   merged_notes.update_from(dest_notes);
1399   return set_node_notes_at(dest->_idx, &merged_notes);
1400 }
1401 
1402 
1403 //--------------------------allow_range_check_smearing-------------------------
1404 // Gating condition for coalescing similar range checks.
1405 // Sometimes we try 'speculatively' replacing a series of a range checks by a
1406 // single covering check that is at least as strong as any of them.
1407 // If the optimization succeeds, the simplified (strengthened) range check
1408 // will always succeed.  If it fails, we will deopt, and then give up
1409 // on the optimization.
1410 bool Compile::allow_range_check_smearing() const {
1411   // If this method has already thrown a range-check,
1412   // assume it was because we already tried range smearing
1413   // and it failed.
1414   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
1415   return !already_trapped;
1416 }
1417 
1418 
1419 //------------------------------flatten_alias_type-----------------------------
1420 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
1421   int offset = tj->offset();
1422   TypePtr::PTR ptr = tj->ptr();
1423 
1424   // Known instance (scalarizable allocation) alias only with itself.
1425   bool is_known_inst = tj->isa_oopptr() != NULL &&
1426                        tj->is_oopptr()->is_known_instance();
1427 
1428   // Process weird unsafe references.
1429   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
1430     assert(InlineUnsafeOps, "indeterminate pointers come only from unsafe ops");
1431     assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
1432     tj = TypeOopPtr::BOTTOM;
1433     ptr = tj->ptr();
1434     offset = tj->offset();
1435   }
1436 
1437   // Array pointers need some flattening
1438   const TypeAryPtr *ta = tj->isa_aryptr();
1439   if (ta && ta->is_stable()) {
1440     // Erase stability property for alias analysis.
1441     tj = ta = ta->cast_to_stable(false);
1442   }
1443   if( ta && is_known_inst ) {
1444     if ( offset != Type::OffsetBot &&
1445          offset > arrayOopDesc::length_offset_in_bytes() ) {
1446       offset = Type::OffsetBot; // Flatten constant access into array body only
1447       tj = ta = TypeAryPtr::make(ptr, ta->ary(), ta->klass(), true, offset, ta->instance_id());
1448     }
1449   } else if( ta && _AliasLevel >= 2 ) {
1450     // For arrays indexed by constant indices, we flatten the alias
1451     // space to include all of the array body.  Only the header, klass
1452     // and array length can be accessed un-aliased.
1453     if( offset != Type::OffsetBot ) {
1454       if( ta->const_oop() ) { // MethodData* or Method*
1455         offset = Type::OffsetBot;   // Flatten constant access into array body
1456         tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),ta->ary(),ta->klass(),false,offset);
1457       } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
1458         // range is OK as-is.
1459         tj = ta = TypeAryPtr::RANGE;
1460       } else if( offset == oopDesc::klass_offset_in_bytes() ) {
1461         tj = TypeInstPtr::KLASS; // all klass loads look alike
1462         ta = TypeAryPtr::RANGE; // generic ignored junk
1463         ptr = TypePtr::BotPTR;
1464       } else if( offset == oopDesc::mark_offset_in_bytes() ) {
1465         tj = TypeInstPtr::MARK;
1466         ta = TypeAryPtr::RANGE; // generic ignored junk
1467         ptr = TypePtr::BotPTR;
1468       } else if (BarrierSet::barrier_set()->barrier_set_c2()->flatten_gc_alias_type(tj)) {
1469         ta = tj->isa_aryptr();
1470       } else {                  // Random constant offset into array body
1471         offset = Type::OffsetBot;   // Flatten constant access into array body
1472         tj = ta = TypeAryPtr::make(ptr,ta->ary(),ta->klass(),false,offset);
1473       }
1474     }
1475     // Arrays of fixed size alias with arrays of unknown size.
1476     if (ta->size() != TypeInt::POS) {
1477       const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
1478       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,ta->klass(),false,offset);
1479     }
1480     // Arrays of known objects become arrays of unknown objects.
1481     if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
1482       const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
1483       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1484     }
1485     if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
1486       const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
1487       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1488     }
1489     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
1490     // cannot be distinguished by bytecode alone.
1491     if (ta->elem() == TypeInt::BOOL) {
1492       const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
1493       ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
1494       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,offset);
1495     }
1496     // During the 2nd round of IterGVN, NotNull castings are removed.
1497     // Make sure the Bottom and NotNull variants alias the same.
1498     // Also, make sure exact and non-exact variants alias the same.
1499     if (ptr == TypePtr::NotNull || ta->klass_is_exact() || ta->speculative() != NULL) {
1500       tj = ta = TypeAryPtr::make(TypePtr::BotPTR,ta->ary(),ta->klass(),false,offset);
1501     }
1502   }
1503 
1504   // Oop pointers need some flattening
1505   const TypeInstPtr *to = tj->isa_instptr();
1506   if( to && _AliasLevel >= 2 && to != TypeOopPtr::BOTTOM ) {
1507     ciInstanceKlass *k = to->klass()->as_instance_klass();
1508     if( ptr == TypePtr::Constant ) {
1509       if (to->klass() != ciEnv::current()->Class_klass() ||
1510           offset < k->size_helper() * wordSize) {
1511         // No constant oop pointers (such as Strings); they alias with
1512         // unknown strings.
1513         assert(!is_known_inst, "not scalarizable allocation");
1514         tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1515       }
1516     } else if( is_known_inst ) {
1517       tj = to; // Keep NotNull and klass_is_exact for instance type
1518     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
1519       // During the 2nd round of IterGVN, NotNull castings are removed.
1520       // Make sure the Bottom and NotNull variants alias the same.
1521       // Also, make sure exact and non-exact variants alias the same.
1522       tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1523     }
1524     if (to->speculative() != NULL) {
1525       tj = to = TypeInstPtr::make(to->ptr(),to->klass(),to->klass_is_exact(),to->const_oop(),to->offset(), to->instance_id());
1526     }
1527     // Canonicalize the holder of this field
1528     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
1529       // First handle header references such as a LoadKlassNode, even if the
1530       // object's klass is unloaded at compile time (4965979).
1531       if (!is_known_inst) { // Do it only for non-instance types
1532         tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, NULL, offset);
1533       }
1534     } else if (BarrierSet::barrier_set()->barrier_set_c2()->flatten_gc_alias_type(tj)) {
1535       to = tj->is_instptr();
1536     } else if (offset < 0 || offset >= k->size_helper() * wordSize) {
1537       // Static fields are in the space above the normal instance
1538       // fields in the java.lang.Class instance.
1539       if (to->klass() != ciEnv::current()->Class_klass()) {
1540         to = NULL;
1541         tj = TypeOopPtr::BOTTOM;
1542         offset = tj->offset();
1543       }
1544     } else {
1545       ciInstanceKlass *canonical_holder = k->get_canonical_holder(offset);
1546       if (!k->equals(canonical_holder) || tj->offset() != offset) {
1547         if( is_known_inst ) {
1548           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, true, NULL, offset, to->instance_id());
1549         } else {
1550           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, false, NULL, offset);
1551         }
1552       }
1553     }
1554   }
1555 
1556   // Klass pointers to object array klasses need some flattening
1557   const TypeKlassPtr *tk = tj->isa_klassptr();
1558   if( tk ) {
1559     // If we are referencing a field within a Klass, we need
1560     // to assume the worst case of an Object.  Both exact and
1561     // inexact types must flatten to the same alias class so
1562     // use NotNull as the PTR.
1563     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
1564 
1565       tj = tk = TypeKlassPtr::make(TypePtr::NotNull,
1566                                    TypeKlassPtr::OBJECT->klass(),
1567                                    offset);
1568     }
1569 
1570     ciKlass* klass = tk->klass();
1571     if( klass->is_obj_array_klass() ) {
1572       ciKlass* k = TypeAryPtr::OOPS->klass();
1573       if( !k || !k->is_loaded() )                  // Only fails for some -Xcomp runs
1574         k = TypeInstPtr::BOTTOM->klass();
1575       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, k, offset );
1576     }
1577 
1578     // Check for precise loads from the primary supertype array and force them
1579     // to the supertype cache alias index.  Check for generic array loads from
1580     // the primary supertype array and also force them to the supertype cache
1581     // alias index.  Since the same load can reach both, we need to merge
1582     // these 2 disparate memories into the same alias class.  Since the
1583     // primary supertype array is read-only, there's no chance of confusion
1584     // where we bypass an array load and an array store.
1585     int primary_supers_offset = in_bytes(Klass::primary_supers_offset());
1586     if (offset == Type::OffsetBot ||
1587         (offset >= primary_supers_offset &&
1588          offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
1589         offset == (int)in_bytes(Klass::secondary_super_cache_offset())) {
1590       offset = in_bytes(Klass::secondary_super_cache_offset());
1591       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, tk->klass(), offset );
1592     }
1593   }
1594 
1595   // Flatten all Raw pointers together.
1596   if (tj->base() == Type::RawPtr)
1597     tj = TypeRawPtr::BOTTOM;
1598 
1599   if (tj->base() == Type::AnyPtr)
1600     tj = TypePtr::BOTTOM;      // An error, which the caller must check for.
1601 
1602   // Flatten all to bottom for now
1603   switch( _AliasLevel ) {
1604   case 0:
1605     tj = TypePtr::BOTTOM;
1606     break;
1607   case 1:                       // Flatten to: oop, static, field or array
1608     switch (tj->base()) {
1609     //case Type::AryPtr: tj = TypeAryPtr::RANGE;    break;
1610     case Type::RawPtr:   tj = TypeRawPtr::BOTTOM;   break;
1611     case Type::AryPtr:   // do not distinguish arrays at all
1612     case Type::InstPtr:  tj = TypeInstPtr::BOTTOM;  break;
1613     case Type::KlassPtr: tj = TypeKlassPtr::OBJECT; break;
1614     case Type::AnyPtr:   tj = TypePtr::BOTTOM;      break;  // caller checks it
1615     default: ShouldNotReachHere();
1616     }
1617     break;
1618   case 2:                       // No collapsing at level 2; keep all splits
1619   case 3:                       // No collapsing at level 3; keep all splits
1620     break;
1621   default:
1622     Unimplemented();
1623   }
1624 
1625   offset = tj->offset();
1626   assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
1627 
1628   assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
1629           (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
1630           (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
1631           (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
1632           (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1633           (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1634           (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1635           (BarrierSet::barrier_set()->barrier_set_c2()->verify_gc_alias_type(tj, offset)),
1636           "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
1637   assert( tj->ptr() != TypePtr::TopPTR &&
1638           tj->ptr() != TypePtr::AnyNull &&
1639           tj->ptr() != TypePtr::Null, "No imprecise addresses" );
1640 //    assert( tj->ptr() != TypePtr::Constant ||
1641 //            tj->base() == Type::RawPtr ||
1642 //            tj->base() == Type::KlassPtr, "No constant oop addresses" );
1643 
1644   return tj;
1645 }
1646 
1647 void Compile::AliasType::Init(int i, const TypePtr* at) {
1648   _index = i;
1649   _adr_type = at;
1650   _field = NULL;
1651   _element = NULL;
1652   _is_rewritable = true; // default
1653   const TypeOopPtr *atoop = (at != NULL) ? at->isa_oopptr() : NULL;
1654   if (atoop != NULL && atoop->is_known_instance()) {
1655     const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
1656     _general_index = Compile::current()->get_alias_index(gt);
1657   } else {
1658     _general_index = 0;
1659   }
1660 }
1661 
1662 BasicType Compile::AliasType::basic_type() const {
1663   if (element() != NULL) {
1664     const Type* element = adr_type()->is_aryptr()->elem();
1665     return element->isa_narrowoop() ? T_OBJECT : element->array_element_basic_type();
1666   } if (field() != NULL) {
1667     return field()->layout_type();
1668   } else {
1669     return T_ILLEGAL; // unknown
1670   }
1671 }
1672 
1673 //---------------------------------print_on------------------------------------
1674 #ifndef PRODUCT
1675 void Compile::AliasType::print_on(outputStream* st) {
1676   if (index() < 10)
1677         st->print("@ <%d> ", index());
1678   else  st->print("@ <%d>",  index());
1679   st->print(is_rewritable() ? "   " : " RO");
1680   int offset = adr_type()->offset();
1681   if (offset == Type::OffsetBot)
1682         st->print(" +any");
1683   else  st->print(" +%-3d", offset);
1684   st->print(" in ");
1685   adr_type()->dump_on(st);
1686   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
1687   if (field() != NULL && tjp) {
1688     if (tjp->klass()  != field()->holder() ||
1689         tjp->offset() != field()->offset_in_bytes()) {
1690       st->print(" != ");
1691       field()->print();
1692       st->print(" ***");
1693     }
1694   }
1695 }
1696 
1697 void print_alias_types() {
1698   Compile* C = Compile::current();
1699   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
1700   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
1701     C->alias_type(idx)->print_on(tty);
1702     tty->cr();
1703   }
1704 }
1705 #endif
1706 
1707 
1708 //----------------------------probe_alias_cache--------------------------------
1709 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
1710   intptr_t key = (intptr_t) adr_type;
1711   key ^= key >> logAliasCacheSize;
1712   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
1713 }
1714 
1715 
1716 //-----------------------------grow_alias_types--------------------------------
1717 void Compile::grow_alias_types() {
1718   const int old_ats  = _max_alias_types; // how many before?
1719   const int new_ats  = old_ats;          // how many more?
1720   const int grow_ats = old_ats+new_ats;  // how many now?
1721   _max_alias_types = grow_ats;
1722   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
1723   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
1724   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
1725   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
1726 }
1727 
1728 
1729 //--------------------------------find_alias_type------------------------------
1730 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field) {
1731   if (_AliasLevel == 0)
1732     return alias_type(AliasIdxBot);
1733 
1734   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1735   if (ace->_adr_type == adr_type) {
1736     return alias_type(ace->_index);
1737   }
1738 
1739   // Handle special cases.
1740   if (adr_type == NULL)             return alias_type(AliasIdxTop);
1741   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
1742 
1743   // Do it the slow way.
1744   const TypePtr* flat = flatten_alias_type(adr_type);
1745 
1746 #ifdef ASSERT
1747   {
1748     ResourceMark rm;
1749     assert(flat == flatten_alias_type(flat), "not idempotent: adr_type = %s; flat = %s => %s",
1750            Type::str(adr_type), Type::str(flat), Type::str(flatten_alias_type(flat)));
1751     assert(flat != TypePtr::BOTTOM, "cannot alias-analyze an untyped ptr: adr_type = %s",
1752            Type::str(adr_type));
1753     if (flat->isa_oopptr() && !flat->isa_klassptr()) {
1754       const TypeOopPtr* foop = flat->is_oopptr();
1755       // Scalarizable allocations have exact klass always.
1756       bool exact = !foop->klass_is_exact() || foop->is_known_instance();
1757       const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
1758       assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type: foop = %s; xoop = %s",
1759              Type::str(foop), Type::str(xoop));
1760     }
1761   }
1762 #endif
1763 
1764   int idx = AliasIdxTop;
1765   for (int i = 0; i < num_alias_types(); i++) {
1766     if (alias_type(i)->adr_type() == flat) {
1767       idx = i;
1768       break;
1769     }
1770   }
1771 
1772   if (idx == AliasIdxTop) {
1773     if (no_create)  return NULL;
1774     // Grow the array if necessary.
1775     if (_num_alias_types == _max_alias_types)  grow_alias_types();
1776     // Add a new alias type.
1777     idx = _num_alias_types++;
1778     _alias_types[idx]->Init(idx, flat);
1779     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
1780     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
1781     if (flat->isa_instptr()) {
1782       if (flat->offset() == java_lang_Class::klass_offset_in_bytes()
1783           && flat->is_instptr()->klass() == env()->Class_klass())
1784         alias_type(idx)->set_rewritable(false);
1785     }
1786     if (flat->isa_aryptr()) {
1787 #ifdef ASSERT
1788       const int header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1789       // (T_BYTE has the weakest alignment and size restrictions...)
1790       assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
1791 #endif
1792       if (flat->offset() == TypePtr::OffsetBot) {
1793         alias_type(idx)->set_element(flat->is_aryptr()->elem());
1794       }
1795     }
1796     if (flat->isa_klassptr()) {
1797       if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
1798         alias_type(idx)->set_rewritable(false);
1799       if (flat->offset() == in_bytes(Klass::modifier_flags_offset()))
1800         alias_type(idx)->set_rewritable(false);
1801       if (flat->offset() == in_bytes(Klass::access_flags_offset()))
1802         alias_type(idx)->set_rewritable(false);
1803       if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
1804         alias_type(idx)->set_rewritable(false);
1805     }
1806     // %%% (We would like to finalize JavaThread::threadObj_offset(),
1807     // but the base pointer type is not distinctive enough to identify
1808     // references into JavaThread.)
1809 
1810     // Check for final fields.
1811     const TypeInstPtr* tinst = flat->isa_instptr();
1812     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
1813       ciField* field;
1814       if (tinst->const_oop() != NULL &&
1815           tinst->klass() == ciEnv::current()->Class_klass() &&
1816           tinst->offset() >= (tinst->klass()->as_instance_klass()->size_helper() * wordSize)) {
1817         // static field
1818         ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
1819         field = k->get_field_by_offset(tinst->offset(), true);
1820       } else {
1821         ciInstanceKlass *k = tinst->klass()->as_instance_klass();
1822         field = k->get_field_by_offset(tinst->offset(), false);
1823       }
1824       assert(field == NULL ||
1825              original_field == NULL ||
1826              (field->holder() == original_field->holder() &&
1827               field->offset() == original_field->offset() &&
1828               field->is_static() == original_field->is_static()), "wrong field?");
1829       // Set field() and is_rewritable() attributes.
1830       if (field != NULL)  alias_type(idx)->set_field(field);
1831     }
1832   }
1833 
1834   // Fill the cache for next time.
1835   ace->_adr_type = adr_type;
1836   ace->_index    = idx;
1837   assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
1838 
1839   // Might as well try to fill the cache for the flattened version, too.
1840   AliasCacheEntry* face = probe_alias_cache(flat);
1841   if (face->_adr_type == NULL) {
1842     face->_adr_type = flat;
1843     face->_index    = idx;
1844     assert(alias_type(flat) == alias_type(idx), "flat type must work too");
1845   }
1846 
1847   return alias_type(idx);
1848 }
1849 
1850 
1851 Compile::AliasType* Compile::alias_type(ciField* field) {
1852   const TypeOopPtr* t;
1853   if (field->is_static())
1854     t = TypeInstPtr::make(field->holder()->java_mirror());
1855   else
1856     t = TypeOopPtr::make_from_klass_raw(field->holder());
1857   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);
1858   assert((field->is_final() || field->is_stable()) == !atp->is_rewritable(), "must get the rewritable bits correct");
1859   return atp;
1860 }
1861 
1862 
1863 //------------------------------have_alias_type--------------------------------
1864 bool Compile::have_alias_type(const TypePtr* adr_type) {
1865   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1866   if (ace->_adr_type == adr_type) {
1867     return true;
1868   }
1869 
1870   // Handle special cases.
1871   if (adr_type == NULL)             return true;
1872   if (adr_type == TypePtr::BOTTOM)  return true;
1873 
1874   return find_alias_type(adr_type, true, NULL) != NULL;
1875 }
1876 
1877 //-----------------------------must_alias--------------------------------------
1878 // True if all values of the given address type are in the given alias category.
1879 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
1880   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1881   if (adr_type == NULL)                 return true;  // NULL serves as TypePtr::TOP
1882   if (alias_idx == AliasIdxTop)         return false; // the empty category
1883   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
1884 
1885   // the only remaining possible overlap is identity
1886   int adr_idx = get_alias_index(adr_type);
1887   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1888   assert(adr_idx == alias_idx ||
1889          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
1890           && adr_type                       != TypeOopPtr::BOTTOM),
1891          "should not be testing for overlap with an unsafe pointer");
1892   return adr_idx == alias_idx;
1893 }
1894 
1895 //------------------------------can_alias--------------------------------------
1896 // True if any values of the given address type are in the given alias category.
1897 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
1898   if (alias_idx == AliasIdxTop)         return false; // the empty category
1899   if (adr_type == NULL)                 return false; // NULL serves as TypePtr::TOP
1900   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1901   if (adr_type->base() == Type::AnyPtr) return true;  // TypePtr::BOTTOM or its twins
1902 
1903   // the only remaining possible overlap is identity
1904   int adr_idx = get_alias_index(adr_type);
1905   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1906   return adr_idx == alias_idx;
1907 }
1908 
1909 
1910 
1911 //---------------------------pop_warm_call-------------------------------------
1912 WarmCallInfo* Compile::pop_warm_call() {
1913   WarmCallInfo* wci = _warm_calls;
1914   if (wci != NULL)  _warm_calls = wci->remove_from(wci);
1915   return wci;
1916 }
1917 
1918 //----------------------------Inline_Warm--------------------------------------
1919 int Compile::Inline_Warm() {
1920   // If there is room, try to inline some more warm call sites.
1921   // %%% Do a graph index compaction pass when we think we're out of space?
1922   if (!InlineWarmCalls)  return 0;
1923 
1924   int calls_made_hot = 0;
1925   int room_to_grow   = NodeCountInliningCutoff - unique();
1926   int amount_to_grow = MIN2(room_to_grow, (int)NodeCountInliningStep);
1927   int amount_grown   = 0;
1928   WarmCallInfo* call;
1929   while (amount_to_grow > 0 && (call = pop_warm_call()) != NULL) {
1930     int est_size = (int)call->size();
1931     if (est_size > (room_to_grow - amount_grown)) {
1932       // This one won't fit anyway.  Get rid of it.
1933       call->make_cold();
1934       continue;
1935     }
1936     call->make_hot();
1937     calls_made_hot++;
1938     amount_grown   += est_size;
1939     amount_to_grow -= est_size;
1940   }
1941 
1942   if (calls_made_hot > 0)  set_major_progress();
1943   return calls_made_hot;
1944 }
1945 
1946 
1947 //----------------------------Finish_Warm--------------------------------------
1948 void Compile::Finish_Warm() {
1949   if (!InlineWarmCalls)  return;
1950   if (failing())  return;
1951   if (warm_calls() == NULL)  return;
1952 
1953   // Clean up loose ends, if we are out of space for inlining.
1954   WarmCallInfo* call;
1955   while ((call = pop_warm_call()) != NULL) {
1956     call->make_cold();
1957   }
1958 }
1959 
1960 //---------------------cleanup_loop_predicates-----------------------
1961 // Remove the opaque nodes that protect the predicates so that all unused
1962 // checks and uncommon_traps will be eliminated from the ideal graph
1963 void Compile::cleanup_loop_predicates(PhaseIterGVN &igvn) {
1964   if (predicate_count()==0) return;
1965   for (int i = predicate_count(); i > 0; i--) {
1966     Node * n = predicate_opaque1_node(i-1);
1967     assert(n->Opcode() == Op_Opaque1, "must be");
1968     igvn.replace_node(n, n->in(1));
1969   }
1970   assert(predicate_count()==0, "should be clean!");
1971 }
1972 
1973 void Compile::add_range_check_cast(Node* n) {
1974   assert(n->isa_CastII()->has_range_check(), "CastII should have range check dependency");
1975   assert(!_range_check_casts->contains(n), "duplicate entry in range check casts");
1976   _range_check_casts->append(n);
1977 }
1978 
1979 // Remove all range check dependent CastIINodes.
1980 void Compile::remove_range_check_casts(PhaseIterGVN &igvn) {
1981   for (int i = range_check_cast_count(); i > 0; i--) {
1982     Node* cast = range_check_cast_node(i-1);
1983     assert(cast->isa_CastII()->has_range_check(), "CastII should have range check dependency");
1984     igvn.replace_node(cast, cast->in(1));
1985   }
1986   assert(range_check_cast_count() == 0, "should be empty");
1987 }
1988 
1989 void Compile::add_opaque4_node(Node* n) {
1990   assert(n->Opcode() == Op_Opaque4, "Opaque4 only");
1991   assert(!_opaque4_nodes->contains(n), "duplicate entry in Opaque4 list");
1992   _opaque4_nodes->append(n);
1993 }
1994 
1995 // Remove all Opaque4 nodes.
1996 void Compile::remove_opaque4_nodes(PhaseIterGVN &igvn) {
1997   for (int i = opaque4_count(); i > 0; i--) {
1998     Node* opaq = opaque4_node(i-1);
1999     assert(opaq->Opcode() == Op_Opaque4, "Opaque4 only");
2000     igvn.replace_node(opaq, opaq->in(2));
2001   }
2002   assert(opaque4_count() == 0, "should be empty");
2003 }
2004 
2005 // StringOpts and late inlining of string methods
2006 void Compile::inline_string_calls(bool parse_time) {
2007   {
2008     // remove useless nodes to make the usage analysis simpler
2009     ResourceMark rm;
2010     PhaseRemoveUseless pru(initial_gvn(), for_igvn());
2011   }
2012 
2013   {
2014     ResourceMark rm;
2015     print_method(PHASE_BEFORE_STRINGOPTS, 3);
2016     PhaseStringOpts pso(initial_gvn(), for_igvn());
2017     print_method(PHASE_AFTER_STRINGOPTS, 3);
2018   }
2019 
2020   // now inline anything that we skipped the first time around
2021   if (!parse_time) {
2022     _late_inlines_pos = _late_inlines.length();
2023   }
2024 
2025   while (_string_late_inlines.length() > 0) {
2026     CallGenerator* cg = _string_late_inlines.pop();
2027     cg->do_late_inline();
2028     if (failing())  return;
2029   }
2030   _string_late_inlines.trunc_to(0);
2031 }
2032 
2033 // Late inlining of boxing methods
2034 void Compile::inline_boxing_calls(PhaseIterGVN& igvn) {
2035   if (_boxing_late_inlines.length() > 0) {
2036     assert(has_boxed_value(), "inconsistent");
2037 
2038     PhaseGVN* gvn = initial_gvn();
2039     set_inlining_incrementally(true);
2040 
2041     assert( igvn._worklist.size() == 0, "should be done with igvn" );
2042     for_igvn()->clear();
2043     gvn->replace_with(&igvn);
2044 
2045     _late_inlines_pos = _late_inlines.length();
2046 
2047     while (_boxing_late_inlines.length() > 0) {
2048       CallGenerator* cg = _boxing_late_inlines.pop();
2049       cg->do_late_inline();
2050       if (failing())  return;
2051     }
2052     _boxing_late_inlines.trunc_to(0);
2053 
2054     {
2055       ResourceMark rm;
2056       PhaseRemoveUseless pru(gvn, for_igvn());
2057     }
2058 
2059     igvn = PhaseIterGVN(gvn);
2060     igvn.optimize();
2061 
2062     set_inlining_progress(false);
2063     set_inlining_incrementally(false);
2064   }
2065 }
2066 
2067 void Compile::inline_incrementally_one(PhaseIterGVN& igvn) {
2068   assert(IncrementalInline, "incremental inlining should be on");
2069   PhaseGVN* gvn = initial_gvn();
2070 
2071   set_inlining_progress(false);
2072   for_igvn()->clear();
2073   gvn->replace_with(&igvn);
2074 
2075   {
2076     TracePhase tp("incrementalInline_inline", &timers[_t_incrInline_inline]);
2077     int i = 0;
2078     for (; i <_late_inlines.length() && !inlining_progress(); i++) {
2079       CallGenerator* cg = _late_inlines.at(i);
2080       _late_inlines_pos = i+1;
2081       cg->do_late_inline();
2082       if (failing())  return;
2083     }
2084     int j = 0;
2085     for (; i < _late_inlines.length(); i++, j++) {
2086       _late_inlines.at_put(j, _late_inlines.at(i));
2087     }
2088     _late_inlines.trunc_to(j);
2089   }
2090 
2091   {
2092     TracePhase tp("incrementalInline_pru", &timers[_t_incrInline_pru]);
2093     ResourceMark rm;
2094     PhaseRemoveUseless pru(gvn, for_igvn());
2095   }
2096 
2097   {
2098     TracePhase tp("incrementalInline_igvn", &timers[_t_incrInline_igvn]);
2099     igvn = PhaseIterGVN(gvn);
2100   }
2101 }
2102 
2103 // Perform incremental inlining until bound on number of live nodes is reached
2104 void Compile::inline_incrementally(PhaseIterGVN& igvn) {
2105   TracePhase tp("incrementalInline", &timers[_t_incrInline]);
2106 
2107   PhaseGVN* gvn = initial_gvn();
2108 
2109   set_inlining_incrementally(true);
2110   set_inlining_progress(true);
2111   uint low_live_nodes = 0;
2112 
2113   while(inlining_progress() && _late_inlines.length() > 0) {
2114 
2115     if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2116       if (low_live_nodes < (uint)LiveNodeCountInliningCutoff * 8 / 10) {
2117         TracePhase tp("incrementalInline_ideal", &timers[_t_incrInline_ideal]);
2118         // PhaseIdealLoop is expensive so we only try it once we are
2119         // out of live nodes and we only try it again if the previous
2120         // helped got the number of nodes down significantly
2121         PhaseIdealLoop ideal_loop(igvn, LoopOptsNone);
2122         if (failing())  return;
2123         low_live_nodes = live_nodes();
2124         _major_progress = true;
2125       }
2126 
2127       if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2128         break;
2129       }
2130     }
2131 
2132     inline_incrementally_one(igvn);
2133 
2134     if (failing())  return;
2135 
2136     {
2137       TracePhase tp("incrementalInline_igvn", &timers[_t_incrInline_igvn]);
2138       igvn.optimize();
2139     }
2140 
2141     if (failing())  return;
2142   }
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     {
2156       TracePhase tp("incrementalInline_pru", &timers[_t_incrInline_pru]);
2157       ResourceMark rm;
2158       PhaseRemoveUseless pru(initial_gvn(), for_igvn());
2159     }
2160 
2161     {
2162       TracePhase tp("incrementalInline_igvn", &timers[_t_incrInline_igvn]);
2163       igvn = PhaseIterGVN(gvn);
2164       igvn.optimize();
2165     }
2166   }
2167 
2168   set_inlining_incrementally(false);
2169 }
2170 
2171 
2172 bool Compile::optimize_loops(PhaseIterGVN& igvn, LoopOptsMode mode) {
2173   if(_loop_opts_cnt > 0) {
2174     debug_only( int cnt = 0; );
2175     while(major_progress() && (_loop_opts_cnt > 0)) {
2176       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2177       assert( cnt++ < 40, "infinite cycle in loop optimization" );
2178       PhaseIdealLoop ideal_loop(igvn, mode);
2179       _loop_opts_cnt--;
2180       if (failing())  return false;
2181       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
2182     }
2183   }
2184   return true;
2185 }
2186 
2187 //------------------------------Optimize---------------------------------------
2188 // Given a graph, optimize it.
2189 void Compile::Optimize() {
2190   TracePhase tp("optimizer", &timers[_t_optimizer]);
2191 
2192 #ifndef PRODUCT
2193   if (_directive->BreakAtCompileOption) {
2194     BREAKPOINT;
2195   }
2196 
2197 #endif
2198 
2199 #ifdef ASSERT
2200   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
2201   bs->verify_gc_barriers(this, BarrierSetC2::BeforeOptimize);
2202 #endif
2203 
2204   ResourceMark rm;
2205 
2206   print_inlining_reinit();
2207 
2208   NOT_PRODUCT( verify_graph_edges(); )
2209 
2210   print_method(PHASE_AFTER_PARSING);
2211 
2212  {
2213   // Iterative Global Value Numbering, including ideal transforms
2214   // Initialize IterGVN with types and values from parse-time GVN
2215   PhaseIterGVN igvn(initial_gvn());
2216 #ifdef ASSERT
2217   _modified_nodes = new (comp_arena()) Unique_Node_List(comp_arena());
2218 #endif
2219   {
2220     TracePhase tp("iterGVN", &timers[_t_iterGVN]);
2221     igvn.optimize();
2222   }
2223 
2224   if (failing())  return;
2225 
2226   print_method(PHASE_ITER_GVN1, 2);
2227 
2228   inline_incrementally(igvn);
2229 
2230   print_method(PHASE_INCREMENTAL_INLINE, 2);
2231 
2232   if (failing())  return;
2233 
2234   if (eliminate_boxing()) {
2235     // Inline valueOf() methods now.
2236     inline_boxing_calls(igvn);
2237 
2238     if (AlwaysIncrementalInline) {
2239       inline_incrementally(igvn);
2240     }
2241 
2242     print_method(PHASE_INCREMENTAL_BOXING_INLINE, 2);
2243 
2244     if (failing())  return;
2245   }
2246 
2247   // Remove the speculative part of types and clean up the graph from
2248   // the extra CastPP nodes whose only purpose is to carry them. Do
2249   // that early so that optimizations are not disrupted by the extra
2250   // CastPP nodes.
2251   remove_speculative_types(igvn);
2252 
2253   // No more new expensive nodes will be added to the list from here
2254   // so keep only the actual candidates for optimizations.
2255   cleanup_expensive_nodes(igvn);
2256 
2257   if (!failing() && RenumberLiveNodes && live_nodes() + NodeLimitFudgeFactor < unique()) {
2258     Compile::TracePhase tp("", &timers[_t_renumberLive]);
2259     initial_gvn()->replace_with(&igvn);
2260     for_igvn()->clear();
2261     Unique_Node_List new_worklist(C->comp_arena());
2262     {
2263       ResourceMark rm;
2264       PhaseRenumberLive prl = PhaseRenumberLive(initial_gvn(), for_igvn(), &new_worklist);
2265     }
2266     set_for_igvn(&new_worklist);
2267     igvn = PhaseIterGVN(initial_gvn());
2268     igvn.optimize();
2269   }
2270 
2271   // Perform escape analysis
2272   if (_do_escape_analysis && ConnectionGraph::has_candidates(this)) {
2273     if (has_loops()) {
2274       // Cleanup graph (remove dead nodes).
2275       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2276       PhaseIdealLoop ideal_loop(igvn, LoopOptsNone);
2277       if (major_progress()) print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
2278       if (failing())  return;
2279     }
2280     ConnectionGraph::do_analysis(this, &igvn);
2281 
2282     if (failing())  return;
2283 
2284     // Optimize out fields loads from scalar replaceable allocations.
2285     igvn.optimize();
2286     print_method(PHASE_ITER_GVN_AFTER_EA, 2);
2287 
2288     if (failing())  return;
2289 
2290     if (congraph() != NULL && macro_count() > 0) {
2291       TracePhase tp("macroEliminate", &timers[_t_macroEliminate]);
2292       PhaseMacroExpand mexp(igvn);
2293       mexp.eliminate_macro_nodes();
2294       igvn.set_delay_transform(false);
2295 
2296       igvn.optimize();
2297       print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
2298 
2299       if (failing())  return;
2300     }
2301   }
2302 
2303   // Loop transforms on the ideal graph.  Range Check Elimination,
2304   // peeling, unrolling, etc.
2305 
2306   // Set loop opts counter
2307   if((_loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
2308     {
2309       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2310       PhaseIdealLoop ideal_loop(igvn, LoopOptsDefault);
2311       _loop_opts_cnt--;
2312       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP1, 2);
2313       if (failing())  return;
2314     }
2315     // Loop opts pass if partial peeling occurred in previous pass
2316     if(PartialPeelLoop && major_progress() && (_loop_opts_cnt > 0)) {
2317       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2318       PhaseIdealLoop ideal_loop(igvn, LoopOptsSkipSplitIf);
2319       _loop_opts_cnt--;
2320       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP2, 2);
2321       if (failing())  return;
2322     }
2323     // Loop opts pass for loop-unrolling before CCP
2324     if(major_progress() && (_loop_opts_cnt > 0)) {
2325       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2326       PhaseIdealLoop ideal_loop(igvn, LoopOptsSkipSplitIf);
2327       _loop_opts_cnt--;
2328       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP3, 2);
2329     }
2330     if (!failing()) {
2331       // Verify that last round of loop opts produced a valid graph
2332       TracePhase tp("idealLoopVerify", &timers[_t_idealLoopVerify]);
2333       PhaseIdealLoop::verify(igvn);
2334     }
2335   }
2336   if (failing())  return;
2337 
2338   // Conditional Constant Propagation;
2339   PhaseCCP ccp( &igvn );
2340   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
2341   {
2342     TracePhase tp("ccp", &timers[_t_ccp]);
2343     ccp.do_transform();
2344   }
2345   print_method(PHASE_CPP1, 2);
2346 
2347   assert( true, "Break here to ccp.dump_old2new_map()");
2348 
2349   // Iterative Global Value Numbering, including ideal transforms
2350   {
2351     TracePhase tp("iterGVN2", &timers[_t_iterGVN2]);
2352     igvn = ccp;
2353     igvn.optimize();
2354   }
2355 
2356   print_method(PHASE_ITER_GVN2, 2);
2357 
2358   if (failing())  return;
2359 
2360   // Loop transforms on the ideal graph.  Range Check Elimination,
2361   // peeling, unrolling, etc.
2362   if (!optimize_loops(igvn, LoopOptsDefault)) {
2363     return;
2364   }
2365 
2366 #if INCLUDE_ZGC
2367   if (UseZGC) {
2368     ZBarrierSetC2::find_dominating_barriers(igvn);
2369   }
2370 #endif
2371 
2372   if (failing())  return;
2373 
2374   // Ensure that major progress is now clear
2375   C->clear_major_progress();
2376 
2377   {
2378     // Verify that all previous optimizations produced a valid graph
2379     // at least to this point, even if no loop optimizations were done.
2380     TracePhase tp("idealLoopVerify", &timers[_t_idealLoopVerify]);
2381     PhaseIdealLoop::verify(igvn);
2382   }
2383 
2384   if (range_check_cast_count() > 0) {
2385     // No more loop optimizations. Remove all range check dependent CastIINodes.
2386     C->remove_range_check_casts(igvn);
2387     igvn.optimize();
2388   }
2389 
2390 #ifdef ASSERT
2391   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
2392   bs->verify_gc_barriers(this, BarrierSetC2::BeforeExpand);
2393 #endif
2394 
2395   {
2396     TracePhase tp("macroExpand", &timers[_t_macroExpand]);
2397     PhaseMacroExpand  mex(igvn);
2398     print_method(PHASE_BEFORE_MACRO_EXPANSION, 2);
2399     if (mex.expand_macro_nodes()) {
2400       assert(failing(), "must bail out w/ explicit message");
2401       return;
2402     }
2403   }
2404 
2405   {
2406     TracePhase tp("barrierExpand", &timers[_t_barrierExpand]);
2407     print_method(PHASE_BEFORE_BARRIER_EXPAND, 2);
2408     BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
2409     if (bs->expand_barriers(this, igvn)) {
2410       assert(failing(), "must bail out w/ explicit message");
2411       return;
2412     }
2413   }
2414 
2415   if (opaque4_count() > 0) {
2416     C->remove_opaque4_nodes(igvn);
2417     igvn.optimize();
2418   }
2419 
2420   DEBUG_ONLY( _modified_nodes = NULL; )
2421  } // (End scope of igvn; run destructor if necessary for asserts.)
2422 
2423  process_print_inlining();
2424  // A method with only infinite loops has no edges entering loops from root
2425  {
2426    TracePhase tp("graphReshape", &timers[_t_graphReshaping]);
2427    if (final_graph_reshaping()) {
2428      assert(failing(), "must bail out w/ explicit message");
2429      return;
2430    }
2431  }
2432 
2433  print_method(PHASE_OPTIMIZE_FINISHED, 2);
2434 }
2435 
2436 
2437 //------------------------------Code_Gen---------------------------------------
2438 // Given a graph, generate code for it
2439 void Compile::Code_Gen() {
2440   if (failing()) {
2441     return;
2442   }
2443 
2444   // Perform instruction selection.  You might think we could reclaim Matcher
2445   // memory PDQ, but actually the Matcher is used in generating spill code.
2446   // Internals of the Matcher (including some VectorSets) must remain live
2447   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
2448   // set a bit in reclaimed memory.
2449 
2450   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2451   // nodes.  Mapping is only valid at the root of each matched subtree.
2452   NOT_PRODUCT( verify_graph_edges(); )
2453 
2454   Matcher matcher;
2455   _matcher = &matcher;
2456   {
2457     TracePhase tp("matcher", &timers[_t_matcher]);
2458     matcher.match();
2459   }
2460   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2461   // nodes.  Mapping is only valid at the root of each matched subtree.
2462   NOT_PRODUCT( verify_graph_edges(); )
2463 
2464   // If you have too many nodes, or if matching has failed, bail out
2465   check_node_count(0, "out of nodes matching instructions");
2466   if (failing()) {
2467     return;
2468   }
2469 
2470   print_method(PHASE_MATCHING, 2);
2471 
2472   // Build a proper-looking CFG
2473   PhaseCFG cfg(node_arena(), root(), matcher);
2474   _cfg = &cfg;
2475   {
2476     TracePhase tp("scheduler", &timers[_t_scheduler]);
2477     bool success = cfg.do_global_code_motion();
2478     if (!success) {
2479       return;
2480     }
2481 
2482     print_method(PHASE_GLOBAL_CODE_MOTION, 2);
2483     NOT_PRODUCT( verify_graph_edges(); )
2484     debug_only( cfg.verify(); )
2485   }
2486 
2487   PhaseChaitin regalloc(unique(), cfg, matcher, false);
2488   _regalloc = &regalloc;
2489   {
2490     TracePhase tp("regalloc", &timers[_t_registerAllocation]);
2491     // Perform register allocation.  After Chaitin, use-def chains are
2492     // no longer accurate (at spill code) and so must be ignored.
2493     // Node->LRG->reg mappings are still accurate.
2494     _regalloc->Register_Allocate();
2495 
2496     // Bail out if the allocator builds too many nodes
2497     if (failing()) {
2498       return;
2499     }
2500   }
2501 
2502   // Prior to register allocation we kept empty basic blocks in case the
2503   // the allocator needed a place to spill.  After register allocation we
2504   // are not adding any new instructions.  If any basic block is empty, we
2505   // can now safely remove it.
2506   {
2507     TracePhase tp("blockOrdering", &timers[_t_blockOrdering]);
2508     cfg.remove_empty_blocks();
2509     if (do_freq_based_layout()) {
2510       PhaseBlockLayout layout(cfg);
2511     } else {
2512       cfg.set_loop_alignment();
2513     }
2514     cfg.fixup_flow();
2515   }
2516 
2517   // Apply peephole optimizations
2518   if( OptoPeephole ) {
2519     TracePhase tp("peephole", &timers[_t_peephole]);
2520     PhasePeephole peep( _regalloc, cfg);
2521     peep.do_transform();
2522   }
2523 
2524   // Do late expand if CPU requires this.
2525   if (Matcher::require_postalloc_expand) {
2526     TracePhase tp("postalloc_expand", &timers[_t_postalloc_expand]);
2527     cfg.postalloc_expand(_regalloc);
2528   }
2529 
2530   // Convert Nodes to instruction bits in a buffer
2531   {
2532     TraceTime tp("output", &timers[_t_output], CITime);
2533     Output();
2534   }
2535 
2536   print_method(PHASE_FINAL_CODE);
2537 
2538   // He's dead, Jim.
2539   _cfg     = (PhaseCFG*)((intptr_t)0xdeadbeef);
2540   _regalloc = (PhaseChaitin*)((intptr_t)0xdeadbeef);
2541 }
2542 
2543 
2544 //------------------------------dump_asm---------------------------------------
2545 // Dump formatted assembly
2546 #ifndef PRODUCT
2547 void Compile::dump_asm(int *pcs, uint pc_limit) {
2548   bool cut_short = false;
2549   tty->print_cr("#");
2550   tty->print("#  ");  _tf->dump();  tty->cr();
2551   tty->print_cr("#");
2552 
2553   // For all blocks
2554   int pc = 0x0;                 // Program counter
2555   char starts_bundle = ' ';
2556   _regalloc->dump_frame();
2557 
2558   Node *n = NULL;
2559   for (uint i = 0; i < _cfg->number_of_blocks(); i++) {
2560     if (VMThread::should_terminate()) {
2561       cut_short = true;
2562       break;
2563     }
2564     Block* block = _cfg->get_block(i);
2565     if (block->is_connector() && !Verbose) {
2566       continue;
2567     }
2568     n = block->head();
2569     if (pcs && n->_idx < pc_limit) {
2570       tty->print("%3.3x   ", pcs[n->_idx]);
2571     } else {
2572       tty->print("      ");
2573     }
2574     block->dump_head(_cfg);
2575     if (block->is_connector()) {
2576       tty->print_cr("        # Empty connector block");
2577     } else if (block->num_preds() == 2 && block->pred(1)->is_CatchProj() && block->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
2578       tty->print_cr("        # Block is sole successor of call");
2579     }
2580 
2581     // For all instructions
2582     Node *delay = NULL;
2583     for (uint j = 0; j < block->number_of_nodes(); j++) {
2584       if (VMThread::should_terminate()) {
2585         cut_short = true;
2586         break;
2587       }
2588       n = block->get_node(j);
2589       if (valid_bundle_info(n)) {
2590         Bundle* bundle = node_bundling(n);
2591         if (bundle->used_in_unconditional_delay()) {
2592           delay = n;
2593           continue;
2594         }
2595         if (bundle->starts_bundle()) {
2596           starts_bundle = '+';
2597         }
2598       }
2599 
2600       if (WizardMode) {
2601         n->dump();
2602       }
2603 
2604       if( !n->is_Region() &&    // Dont print in the Assembly
2605           !n->is_Phi() &&       // a few noisely useless nodes
2606           !n->is_Proj() &&
2607           !n->is_MachTemp() &&
2608           !n->is_SafePointScalarObject() &&
2609           !n->is_Catch() &&     // Would be nice to print exception table targets
2610           !n->is_MergeMem() &&  // Not very interesting
2611           !n->is_top() &&       // Debug info table constants
2612           !(n->is_Con() && !n->is_Mach())// Debug info table constants
2613           ) {
2614         if (pcs && n->_idx < pc_limit)
2615           tty->print("%3.3x", pcs[n->_idx]);
2616         else
2617           tty->print("   ");
2618         tty->print(" %c ", starts_bundle);
2619         starts_bundle = ' ';
2620         tty->print("\t");
2621         n->format(_regalloc, tty);
2622         tty->cr();
2623       }
2624 
2625       // If we have an instruction with a delay slot, and have seen a delay,
2626       // then back up and print it
2627       if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
2628         assert(delay != NULL, "no unconditional delay instruction");
2629         if (WizardMode) delay->dump();
2630 
2631         if (node_bundling(delay)->starts_bundle())
2632           starts_bundle = '+';
2633         if (pcs && n->_idx < pc_limit)
2634           tty->print("%3.3x", pcs[n->_idx]);
2635         else
2636           tty->print("   ");
2637         tty->print(" %c ", starts_bundle);
2638         starts_bundle = ' ';
2639         tty->print("\t");
2640         delay->format(_regalloc, tty);
2641         tty->cr();
2642         delay = NULL;
2643       }
2644 
2645       // Dump the exception table as well
2646       if( n->is_Catch() && (Verbose || WizardMode) ) {
2647         // Print the exception table for this offset
2648         _handler_table.print_subtable_for(pc);
2649       }
2650     }
2651 
2652     if (pcs && n->_idx < pc_limit)
2653       tty->print_cr("%3.3x", pcs[n->_idx]);
2654     else
2655       tty->cr();
2656 
2657     assert(cut_short || delay == NULL, "no unconditional delay branch");
2658 
2659   } // End of per-block dump
2660   tty->cr();
2661 
2662   if (cut_short)  tty->print_cr("*** disassembly is cut short ***");
2663 }
2664 #endif
2665 
2666 //------------------------------Final_Reshape_Counts---------------------------
2667 // This class defines counters to help identify when a method
2668 // may/must be executed using hardware with only 24-bit precision.
2669 struct Final_Reshape_Counts : public StackObj {
2670   int  _call_count;             // count non-inlined 'common' calls
2671   int  _float_count;            // count float ops requiring 24-bit precision
2672   int  _double_count;           // count double ops requiring more precision
2673   int  _java_call_count;        // count non-inlined 'java' calls
2674   int  _inner_loop_count;       // count loops which need alignment
2675   VectorSet _visited;           // Visitation flags
2676   Node_List _tests;             // Set of IfNodes & PCTableNodes
2677 
2678   Final_Reshape_Counts() :
2679     _call_count(0), _float_count(0), _double_count(0),
2680     _java_call_count(0), _inner_loop_count(0),
2681     _visited( Thread::current()->resource_area() ) { }
2682 
2683   void inc_call_count  () { _call_count  ++; }
2684   void inc_float_count () { _float_count ++; }
2685   void inc_double_count() { _double_count++; }
2686   void inc_java_call_count() { _java_call_count++; }
2687   void inc_inner_loop_count() { _inner_loop_count++; }
2688 
2689   int  get_call_count  () const { return _call_count  ; }
2690   int  get_float_count () const { return _float_count ; }
2691   int  get_double_count() const { return _double_count; }
2692   int  get_java_call_count() const { return _java_call_count; }
2693   int  get_inner_loop_count() const { return _inner_loop_count; }
2694 };
2695 
2696 #ifdef ASSERT
2697 static bool oop_offset_is_sane(const TypeInstPtr* tp) {
2698   ciInstanceKlass *k = tp->klass()->as_instance_klass();
2699   // Make sure the offset goes inside the instance layout.
2700   return k->contains_field_offset(tp->offset());
2701   // Note that OffsetBot and OffsetTop are very negative.
2702 }
2703 #endif
2704 
2705 // Eliminate trivially redundant StoreCMs and accumulate their
2706 // precedence edges.
2707 void Compile::eliminate_redundant_card_marks(Node* n) {
2708   assert(n->Opcode() == Op_StoreCM, "expected StoreCM");
2709   if (n->in(MemNode::Address)->outcnt() > 1) {
2710     // There are multiple users of the same address so it might be
2711     // possible to eliminate some of the StoreCMs
2712     Node* mem = n->in(MemNode::Memory);
2713     Node* adr = n->in(MemNode::Address);
2714     Node* val = n->in(MemNode::ValueIn);
2715     Node* prev = n;
2716     bool done = false;
2717     // Walk the chain of StoreCMs eliminating ones that match.  As
2718     // long as it's a chain of single users then the optimization is
2719     // safe.  Eliminating partially redundant StoreCMs would require
2720     // cloning copies down the other paths.
2721     while (mem->Opcode() == Op_StoreCM && mem->outcnt() == 1 && !done) {
2722       if (adr == mem->in(MemNode::Address) &&
2723           val == mem->in(MemNode::ValueIn)) {
2724         // redundant StoreCM
2725         if (mem->req() > MemNode::OopStore) {
2726           // Hasn't been processed by this code yet.
2727           n->add_prec(mem->in(MemNode::OopStore));
2728         } else {
2729           // Already converted to precedence edge
2730           for (uint i = mem->req(); i < mem->len(); i++) {
2731             // Accumulate any precedence edges
2732             if (mem->in(i) != NULL) {
2733               n->add_prec(mem->in(i));
2734             }
2735           }
2736           // Everything above this point has been processed.
2737           done = true;
2738         }
2739         // Eliminate the previous StoreCM
2740         prev->set_req(MemNode::Memory, mem->in(MemNode::Memory));
2741         assert(mem->outcnt() == 0, "should be dead");
2742         mem->disconnect_inputs(NULL, this);
2743       } else {
2744         prev = mem;
2745       }
2746       mem = prev->in(MemNode::Memory);
2747     }
2748   }
2749 }
2750 
2751 //------------------------------final_graph_reshaping_impl----------------------
2752 // Implement items 1-5 from final_graph_reshaping below.
2753 void Compile::final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &frc) {
2754 
2755   if ( n->outcnt() == 0 ) return; // dead node
2756   uint nop = n->Opcode();
2757 
2758   // Check for 2-input instruction with "last use" on right input.
2759   // Swap to left input.  Implements item (2).
2760   if( n->req() == 3 &&          // two-input instruction
2761       n->in(1)->outcnt() > 1 && // left use is NOT a last use
2762       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
2763       n->in(2)->outcnt() == 1 &&// right use IS a last use
2764       !n->in(2)->is_Con() ) {   // right use is not a constant
2765     // Check for commutative opcode
2766     switch( nop ) {
2767     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddL:
2768     case Op_MaxI:  case Op_MinI:
2769     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulL:
2770     case Op_AndL:  case Op_XorL:  case Op_OrL:
2771     case Op_AndI:  case Op_XorI:  case Op_OrI: {
2772       // Move "last use" input to left by swapping inputs
2773       n->swap_edges(1, 2);
2774       break;
2775     }
2776     default:
2777       break;
2778     }
2779   }
2780 
2781 #ifdef ASSERT
2782   if( n->is_Mem() ) {
2783     int alias_idx = get_alias_index(n->as_Mem()->adr_type());
2784     assert( n->in(0) != NULL || alias_idx != Compile::AliasIdxRaw ||
2785             // oop will be recorded in oop map if load crosses safepoint
2786             n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
2787                              LoadNode::is_immutable_value(n->in(MemNode::Address))),
2788             "raw memory operations should have control edge");
2789   }
2790   if (n->is_MemBar()) {
2791     MemBarNode* mb = n->as_MemBar();
2792     if (mb->trailing_store() || mb->trailing_load_store()) {
2793       assert(mb->leading_membar()->trailing_membar() == mb, "bad membar pair");
2794       Node* mem = mb->in(MemBarNode::Precedent);
2795       assert((mb->trailing_store() && mem->is_Store() && mem->as_Store()->is_release()) ||
2796              (mb->trailing_load_store() && mem->is_LoadStore()), "missing mem op");
2797     } else if (mb->leading()) {
2798       assert(mb->trailing_membar()->leading_membar() == mb, "bad membar pair");
2799     }
2800   }
2801 #endif
2802   // Count FPU ops and common calls, implements item (3)
2803   bool gc_handled = BarrierSet::barrier_set()->barrier_set_c2()->final_graph_reshaping(this, n, nop);
2804   if (!gc_handled) {
2805     final_graph_reshaping_main_switch(n, frc, nop);
2806   }
2807 
2808   // Collect CFG split points
2809   if (n->is_MultiBranch() && !n->is_RangeCheck()) {
2810     frc._tests.push(n);
2811   }
2812 }
2813 
2814 void Compile::final_graph_reshaping_main_switch(Node* n, Final_Reshape_Counts& frc, uint nop) {
2815   switch( nop ) {
2816   // Count all float operations that may use FPU
2817   case Op_AddF:
2818   case Op_SubF:
2819   case Op_MulF:
2820   case Op_DivF:
2821   case Op_NegF:
2822   case Op_ModF:
2823   case Op_ConvI2F:
2824   case Op_ConF:
2825   case Op_CmpF:
2826   case Op_CmpF3:
2827   // case Op_ConvL2F: // longs are split into 32-bit halves
2828     frc.inc_float_count();
2829     break;
2830 
2831   case Op_ConvF2D:
2832   case Op_ConvD2F:
2833     frc.inc_float_count();
2834     frc.inc_double_count();
2835     break;
2836 
2837   // Count all double operations that may use FPU
2838   case Op_AddD:
2839   case Op_SubD:
2840   case Op_MulD:
2841   case Op_DivD:
2842   case Op_NegD:
2843   case Op_ModD:
2844   case Op_ConvI2D:
2845   case Op_ConvD2I:
2846   // case Op_ConvL2D: // handled by leaf call
2847   // case Op_ConvD2L: // handled by leaf call
2848   case Op_ConD:
2849   case Op_CmpD:
2850   case Op_CmpD3:
2851     frc.inc_double_count();
2852     break;
2853   case Op_Opaque1:              // Remove Opaque Nodes before matching
2854   case Op_Opaque2:              // Remove Opaque Nodes before matching
2855   case Op_Opaque3:
2856     n->subsume_by(n->in(1), this);
2857     break;
2858   case Op_CallStaticJava:
2859   case Op_CallJava:
2860   case Op_CallDynamicJava:
2861     frc.inc_java_call_count(); // Count java call site;
2862   case Op_CallRuntime:
2863   case Op_CallLeaf:
2864   case Op_CallLeafNoFP: {
2865     assert (n->is_Call(), "");
2866     CallNode *call = n->as_Call();
2867     // Count call sites where the FP mode bit would have to be flipped.
2868     // Do not count uncommon runtime calls:
2869     // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
2870     // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
2871     if (!call->is_CallStaticJava() || !call->as_CallStaticJava()->_name) {
2872       frc.inc_call_count();   // Count the call site
2873     } else {                  // See if uncommon argument is shared
2874       Node *n = call->in(TypeFunc::Parms);
2875       int nop = n->Opcode();
2876       // Clone shared simple arguments to uncommon calls, item (1).
2877       if (n->outcnt() > 1 &&
2878           !n->is_Proj() &&
2879           nop != Op_CreateEx &&
2880           nop != Op_CheckCastPP &&
2881           nop != Op_DecodeN &&
2882           nop != Op_DecodeNKlass &&
2883           !n->is_Mem() &&
2884           !n->is_Phi()) {
2885         Node *x = n->clone();
2886         call->set_req(TypeFunc::Parms, x);
2887       }
2888     }
2889     break;
2890   }
2891 
2892   case Op_StoreD:
2893   case Op_LoadD:
2894   case Op_LoadD_unaligned:
2895     frc.inc_double_count();
2896     goto handle_mem;
2897   case Op_StoreF:
2898   case Op_LoadF:
2899     frc.inc_float_count();
2900     goto handle_mem;
2901 
2902   case Op_StoreCM:
2903     {
2904       // Convert OopStore dependence into precedence edge
2905       Node* prec = n->in(MemNode::OopStore);
2906       n->del_req(MemNode::OopStore);
2907       n->add_prec(prec);
2908       eliminate_redundant_card_marks(n);
2909     }
2910 
2911     // fall through
2912 
2913   case Op_StoreB:
2914   case Op_StoreC:
2915   case Op_StorePConditional:
2916   case Op_StoreI:
2917   case Op_StoreL:
2918   case Op_StoreIConditional:
2919   case Op_StoreLConditional:
2920   case Op_CompareAndSwapB:
2921   case Op_CompareAndSwapS:
2922   case Op_CompareAndSwapI:
2923   case Op_CompareAndSwapL:
2924   case Op_CompareAndSwapP:
2925   case Op_CompareAndSwapN:
2926   case Op_WeakCompareAndSwapB:
2927   case Op_WeakCompareAndSwapS:
2928   case Op_WeakCompareAndSwapI:
2929   case Op_WeakCompareAndSwapL:
2930   case Op_WeakCompareAndSwapP:
2931   case Op_WeakCompareAndSwapN:
2932   case Op_CompareAndExchangeB:
2933   case Op_CompareAndExchangeS:
2934   case Op_CompareAndExchangeI:
2935   case Op_CompareAndExchangeL:
2936   case Op_CompareAndExchangeP:
2937   case Op_CompareAndExchangeN:
2938   case Op_GetAndAddS:
2939   case Op_GetAndAddB:
2940   case Op_GetAndAddI:
2941   case Op_GetAndAddL:
2942   case Op_GetAndSetS:
2943   case Op_GetAndSetB:
2944   case Op_GetAndSetI:
2945   case Op_GetAndSetL:
2946   case Op_GetAndSetP:
2947   case Op_GetAndSetN:
2948   case Op_StoreP:
2949   case Op_StoreN:
2950   case Op_StoreNKlass:
2951   case Op_LoadB:
2952   case Op_LoadUB:
2953   case Op_LoadUS:
2954   case Op_LoadI:
2955   case Op_LoadKlass:
2956   case Op_LoadNKlass:
2957   case Op_LoadL:
2958   case Op_LoadL_unaligned:
2959   case Op_LoadPLocked:
2960   case Op_LoadP:
2961   case Op_LoadN:
2962   case Op_LoadRange:
2963   case Op_LoadS: {
2964   handle_mem:
2965 #ifdef ASSERT
2966     if( VerifyOptoOopOffsets ) {
2967       MemNode* mem  = n->as_Mem();
2968       // Check to see if address types have grounded out somehow.
2969       const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
2970       assert( !tp || oop_offset_is_sane(tp), "" );
2971     }
2972 #endif
2973     break;
2974   }
2975 
2976   case Op_AddP: {               // Assert sane base pointers
2977     Node *addp = n->in(AddPNode::Address);
2978     assert( !addp->is_AddP() ||
2979             addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
2980             addp->in(AddPNode::Base) == n->in(AddPNode::Base),
2981             "Base pointers must match (addp %u)", addp->_idx );
2982 #ifdef _LP64
2983     if ((UseCompressedOops || UseCompressedClassPointers) &&
2984         addp->Opcode() == Op_ConP &&
2985         addp == n->in(AddPNode::Base) &&
2986         n->in(AddPNode::Offset)->is_Con()) {
2987       // If the transformation of ConP to ConN+DecodeN is beneficial depends
2988       // on the platform and on the compressed oops mode.
2989       // Use addressing with narrow klass to load with offset on x86.
2990       // Some platforms can use the constant pool to load ConP.
2991       // Do this transformation here since IGVN will convert ConN back to ConP.
2992       const Type* t = addp->bottom_type();
2993       bool is_oop   = t->isa_oopptr() != NULL;
2994       bool is_klass = t->isa_klassptr() != NULL;
2995 
2996       if ((is_oop   && Matcher::const_oop_prefer_decode()  ) ||
2997           (is_klass && Matcher::const_klass_prefer_decode())) {
2998         Node* nn = NULL;
2999 
3000         int op = is_oop ? Op_ConN : Op_ConNKlass;
3001 
3002         // Look for existing ConN node of the same exact type.
3003         Node* r  = root();
3004         uint cnt = r->outcnt();
3005         for (uint i = 0; i < cnt; i++) {
3006           Node* m = r->raw_out(i);
3007           if (m!= NULL && m->Opcode() == op &&
3008               m->bottom_type()->make_ptr() == t) {
3009             nn = m;
3010             break;
3011           }
3012         }
3013         if (nn != NULL) {
3014           // Decode a narrow oop to match address
3015           // [R12 + narrow_oop_reg<<3 + offset]
3016           if (is_oop) {
3017             nn = new DecodeNNode(nn, t);
3018           } else {
3019             nn = new DecodeNKlassNode(nn, t);
3020           }
3021           // Check for succeeding AddP which uses the same Base.
3022           // Otherwise we will run into the assertion above when visiting that guy.
3023           for (uint i = 0; i < n->outcnt(); ++i) {
3024             Node *out_i = n->raw_out(i);
3025             if (out_i && out_i->is_AddP() && out_i->in(AddPNode::Base) == addp) {
3026               out_i->set_req(AddPNode::Base, nn);
3027 #ifdef ASSERT
3028               for (uint j = 0; j < out_i->outcnt(); ++j) {
3029                 Node *out_j = out_i->raw_out(j);
3030                 assert(out_j == NULL || !out_j->is_AddP() || out_j->in(AddPNode::Base) != addp,
3031                        "more than 2 AddP nodes in a chain (out_j %u)", out_j->_idx);
3032               }
3033 #endif
3034             }
3035           }
3036           n->set_req(AddPNode::Base, nn);
3037           n->set_req(AddPNode::Address, nn);
3038           if (addp->outcnt() == 0) {
3039             addp->disconnect_inputs(NULL, this);
3040           }
3041         }
3042       }
3043     }
3044 #endif
3045     // platform dependent reshaping of the address expression
3046     reshape_address(n->as_AddP());
3047     break;
3048   }
3049 
3050   case Op_CastPP: {
3051     // Remove CastPP nodes to gain more freedom during scheduling but
3052     // keep the dependency they encode as control or precedence edges
3053     // (if control is set already) on memory operations. Some CastPP
3054     // nodes don't have a control (don't carry a dependency): skip
3055     // those.
3056     if (n->in(0) != NULL) {
3057       ResourceMark rm;
3058       Unique_Node_List wq;
3059       wq.push(n);
3060       for (uint next = 0; next < wq.size(); ++next) {
3061         Node *m = wq.at(next);
3062         for (DUIterator_Fast imax, i = m->fast_outs(imax); i < imax; i++) {
3063           Node* use = m->fast_out(i);
3064           if (use->is_Mem() || use->is_EncodeNarrowPtr() || use->is_ShenandoahBarrier()) {
3065             use->ensure_control_or_add_prec(n->in(0));
3066           } else {
3067             switch(use->Opcode()) {
3068             case Op_AddP:
3069             case Op_DecodeN:
3070             case Op_DecodeNKlass:
3071             case Op_CheckCastPP:
3072             case Op_CastPP:
3073               wq.push(use);
3074               break;
3075             }
3076           }
3077         }
3078       }
3079     }
3080     const bool is_LP64 = LP64_ONLY(true) NOT_LP64(false);
3081     if (is_LP64 && n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
3082       Node* in1 = n->in(1);
3083       const Type* t = n->bottom_type();
3084       Node* new_in1 = in1->clone();
3085       new_in1->as_DecodeN()->set_type(t);
3086 
3087       if (!Matcher::narrow_oop_use_complex_address()) {
3088         //
3089         // x86, ARM and friends can handle 2 adds in addressing mode
3090         // and Matcher can fold a DecodeN node into address by using
3091         // a narrow oop directly and do implicit NULL check in address:
3092         //
3093         // [R12 + narrow_oop_reg<<3 + offset]
3094         // NullCheck narrow_oop_reg
3095         //
3096         // On other platforms (Sparc) we have to keep new DecodeN node and
3097         // use it to do implicit NULL check in address:
3098         //
3099         // decode_not_null narrow_oop_reg, base_reg
3100         // [base_reg + offset]
3101         // NullCheck base_reg
3102         //
3103         // Pin the new DecodeN node to non-null path on these platform (Sparc)
3104         // to keep the information to which NULL check the new DecodeN node
3105         // corresponds to use it as value in implicit_null_check().
3106         //
3107         new_in1->set_req(0, n->in(0));
3108       }
3109 
3110       n->subsume_by(new_in1, this);
3111       if (in1->outcnt() == 0) {
3112         in1->disconnect_inputs(NULL, this);
3113       }
3114     } else {
3115       n->subsume_by(n->in(1), this);
3116       if (n->outcnt() == 0) {
3117         n->disconnect_inputs(NULL, this);
3118       }
3119     }
3120     break;
3121   }
3122 #ifdef _LP64
3123   case Op_CmpP:
3124     // Do this transformation here to preserve CmpPNode::sub() and
3125     // other TypePtr related Ideal optimizations (for example, ptr nullness).
3126     if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
3127       Node* in1 = n->in(1);
3128       Node* in2 = n->in(2);
3129       if (!in1->is_DecodeNarrowPtr()) {
3130         in2 = in1;
3131         in1 = n->in(2);
3132       }
3133       assert(in1->is_DecodeNarrowPtr(), "sanity");
3134 
3135       Node* new_in2 = NULL;
3136       if (in2->is_DecodeNarrowPtr()) {
3137         assert(in2->Opcode() == in1->Opcode(), "must be same node type");
3138         new_in2 = in2->in(1);
3139       } else if (in2->Opcode() == Op_ConP) {
3140         const Type* t = in2->bottom_type();
3141         if (t == TypePtr::NULL_PTR) {
3142           assert(in1->is_DecodeN(), "compare klass to null?");
3143           // Don't convert CmpP null check into CmpN if compressed
3144           // oops implicit null check is not generated.
3145           // This will allow to generate normal oop implicit null check.
3146           if (Matcher::gen_narrow_oop_implicit_null_checks())
3147             new_in2 = ConNode::make(TypeNarrowOop::NULL_PTR);
3148           //
3149           // This transformation together with CastPP transformation above
3150           // will generated code for implicit NULL checks for compressed oops.
3151           //
3152           // The original code after Optimize()
3153           //
3154           //    LoadN memory, narrow_oop_reg
3155           //    decode narrow_oop_reg, base_reg
3156           //    CmpP base_reg, NULL
3157           //    CastPP base_reg // NotNull
3158           //    Load [base_reg + offset], val_reg
3159           //
3160           // after these transformations will be
3161           //
3162           //    LoadN memory, narrow_oop_reg
3163           //    CmpN narrow_oop_reg, NULL
3164           //    decode_not_null narrow_oop_reg, base_reg
3165           //    Load [base_reg + offset], val_reg
3166           //
3167           // and the uncommon path (== NULL) will use narrow_oop_reg directly
3168           // since narrow oops can be used in debug info now (see the code in
3169           // final_graph_reshaping_walk()).
3170           //
3171           // At the end the code will be matched to
3172           // on x86:
3173           //
3174           //    Load_narrow_oop memory, narrow_oop_reg
3175           //    Load [R12 + narrow_oop_reg<<3 + offset], val_reg
3176           //    NullCheck narrow_oop_reg
3177           //
3178           // and on sparc:
3179           //
3180           //    Load_narrow_oop memory, narrow_oop_reg
3181           //    decode_not_null narrow_oop_reg, base_reg
3182           //    Load [base_reg + offset], val_reg
3183           //    NullCheck base_reg
3184           //
3185         } else if (t->isa_oopptr()) {
3186           new_in2 = ConNode::make(t->make_narrowoop());
3187         } else if (t->isa_klassptr()) {
3188           new_in2 = ConNode::make(t->make_narrowklass());
3189         }
3190       }
3191       if (new_in2 != NULL) {
3192         Node* cmpN = new CmpNNode(in1->in(1), new_in2);
3193         n->subsume_by(cmpN, this);
3194         if (in1->outcnt() == 0) {
3195           in1->disconnect_inputs(NULL, this);
3196         }
3197         if (in2->outcnt() == 0) {
3198           in2->disconnect_inputs(NULL, this);
3199         }
3200       }
3201     }
3202     break;
3203 
3204   case Op_DecodeN:
3205   case Op_DecodeNKlass:
3206     assert(!n->in(1)->is_EncodeNarrowPtr(), "should be optimized out");
3207     // DecodeN could be pinned when it can't be fold into
3208     // an address expression, see the code for Op_CastPP above.
3209     assert(n->in(0) == NULL || (UseCompressedOops && !Matcher::narrow_oop_use_complex_address()), "no control");
3210     break;
3211 
3212   case Op_EncodeP:
3213   case Op_EncodePKlass: {
3214     Node* in1 = n->in(1);
3215     if (in1->is_DecodeNarrowPtr()) {
3216       n->subsume_by(in1->in(1), this);
3217     } else if (in1->Opcode() == Op_ConP) {
3218       const Type* t = in1->bottom_type();
3219       if (t == TypePtr::NULL_PTR) {
3220         assert(t->isa_oopptr(), "null klass?");
3221         n->subsume_by(ConNode::make(TypeNarrowOop::NULL_PTR), this);
3222       } else if (t->isa_oopptr()) {
3223         n->subsume_by(ConNode::make(t->make_narrowoop()), this);
3224       } else if (t->isa_klassptr()) {
3225         n->subsume_by(ConNode::make(t->make_narrowklass()), this);
3226       }
3227     }
3228     if (in1->outcnt() == 0) {
3229       in1->disconnect_inputs(NULL, this);
3230     }
3231     break;
3232   }
3233 
3234   case Op_Proj: {
3235     if (OptimizeStringConcat) {
3236       ProjNode* p = n->as_Proj();
3237       if (p->_is_io_use) {
3238         // Separate projections were used for the exception path which
3239         // are normally removed by a late inline.  If it wasn't inlined
3240         // then they will hang around and should just be replaced with
3241         // the original one.
3242         Node* proj = NULL;
3243         // Replace with just one
3244         for (SimpleDUIterator i(p->in(0)); i.has_next(); i.next()) {
3245           Node *use = i.get();
3246           if (use->is_Proj() && p != use && use->as_Proj()->_con == p->_con) {
3247             proj = use;
3248             break;
3249           }
3250         }
3251         assert(proj != NULL, "must be found");
3252         p->subsume_by(proj, this);
3253       }
3254     }
3255     break;
3256   }
3257 
3258   case Op_Phi:
3259     if (n->as_Phi()->bottom_type()->isa_narrowoop() || n->as_Phi()->bottom_type()->isa_narrowklass()) {
3260       // The EncodeP optimization may create Phi with the same edges
3261       // for all paths. It is not handled well by Register Allocator.
3262       Node* unique_in = n->in(1);
3263       assert(unique_in != NULL, "");
3264       uint cnt = n->req();
3265       for (uint i = 2; i < cnt; i++) {
3266         Node* m = n->in(i);
3267         assert(m != NULL, "");
3268         if (unique_in != m)
3269           unique_in = NULL;
3270       }
3271       if (unique_in != NULL) {
3272         n->subsume_by(unique_in, this);
3273       }
3274     }
3275     break;
3276 
3277 #endif
3278 
3279 #ifdef ASSERT
3280   case Op_CastII:
3281     // Verify that all range check dependent CastII nodes were removed.
3282     if (n->isa_CastII()->has_range_check()) {
3283       n->dump(3);
3284       assert(false, "Range check dependent CastII node was not removed");
3285     }
3286     break;
3287 #endif
3288 
3289   case Op_ModI:
3290     if (UseDivMod) {
3291       // Check if a%b and a/b both exist
3292       Node* d = n->find_similar(Op_DivI);
3293       if (d) {
3294         // Replace them with a fused divmod if supported
3295         if (Matcher::has_match_rule(Op_DivModI)) {
3296           DivModINode* divmod = DivModINode::make(n);
3297           d->subsume_by(divmod->div_proj(), this);
3298           n->subsume_by(divmod->mod_proj(), this);
3299         } else {
3300           // replace a%b with a-((a/b)*b)
3301           Node* mult = new MulINode(d, d->in(2));
3302           Node* sub  = new SubINode(d->in(1), mult);
3303           n->subsume_by(sub, this);
3304         }
3305       }
3306     }
3307     break;
3308 
3309   case Op_ModL:
3310     if (UseDivMod) {
3311       // Check if a%b and a/b both exist
3312       Node* d = n->find_similar(Op_DivL);
3313       if (d) {
3314         // Replace them with a fused divmod if supported
3315         if (Matcher::has_match_rule(Op_DivModL)) {
3316           DivModLNode* divmod = DivModLNode::make(n);
3317           d->subsume_by(divmod->div_proj(), this);
3318           n->subsume_by(divmod->mod_proj(), this);
3319         } else {
3320           // replace a%b with a-((a/b)*b)
3321           Node* mult = new MulLNode(d, d->in(2));
3322           Node* sub  = new SubLNode(d->in(1), mult);
3323           n->subsume_by(sub, this);
3324         }
3325       }
3326     }
3327     break;
3328 
3329   case Op_LoadVector:
3330   case Op_StoreVector:
3331     break;
3332 
3333   case Op_AddReductionVI:
3334   case Op_AddReductionVL:
3335   case Op_AddReductionVF:
3336   case Op_AddReductionVD:
3337   case Op_MulReductionVI:
3338   case Op_MulReductionVL:
3339   case Op_MulReductionVF:
3340   case Op_MulReductionVD:
3341   case Op_MinReductionV:
3342   case Op_MaxReductionV:
3343     break;
3344 
3345   case Op_PackB:
3346   case Op_PackS:
3347   case Op_PackI:
3348   case Op_PackF:
3349   case Op_PackL:
3350   case Op_PackD:
3351     if (n->req()-1 > 2) {
3352       // Replace many operand PackNodes with a binary tree for matching
3353       PackNode* p = (PackNode*) n;
3354       Node* btp = p->binary_tree_pack(1, n->req());
3355       n->subsume_by(btp, this);
3356     }
3357     break;
3358   case Op_Loop:
3359   case Op_CountedLoop:
3360   case Op_OuterStripMinedLoop:
3361     if (n->as_Loop()->is_inner_loop()) {
3362       frc.inc_inner_loop_count();
3363     }
3364     n->as_Loop()->verify_strip_mined(0);
3365     break;
3366   case Op_LShiftI:
3367   case Op_RShiftI:
3368   case Op_URShiftI:
3369   case Op_LShiftL:
3370   case Op_RShiftL:
3371   case Op_URShiftL:
3372     if (Matcher::need_masked_shift_count) {
3373       // The cpu's shift instructions don't restrict the count to the
3374       // lower 5/6 bits. We need to do the masking ourselves.
3375       Node* in2 = n->in(2);
3376       juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
3377       const TypeInt* t = in2->find_int_type();
3378       if (t != NULL && t->is_con()) {
3379         juint shift = t->get_con();
3380         if (shift > mask) { // Unsigned cmp
3381           n->set_req(2, ConNode::make(TypeInt::make(shift & mask)));
3382         }
3383       } else {
3384         if (t == NULL || t->_lo < 0 || t->_hi > (int)mask) {
3385           Node* shift = new AndINode(in2, ConNode::make(TypeInt::make(mask)));
3386           n->set_req(2, shift);
3387         }
3388       }
3389       if (in2->outcnt() == 0) { // Remove dead node
3390         in2->disconnect_inputs(NULL, this);
3391       }
3392     }
3393     break;
3394   case Op_MemBarStoreStore:
3395   case Op_MemBarRelease:
3396     // Break the link with AllocateNode: it is no longer useful and
3397     // confuses register allocation.
3398     if (n->req() > MemBarNode::Precedent) {
3399       n->set_req(MemBarNode::Precedent, top());
3400     }
3401     break;
3402   case Op_MemBarAcquire: {
3403     if (n->as_MemBar()->trailing_load() && n->req() > MemBarNode::Precedent) {
3404       // At parse time, the trailing MemBarAcquire for a volatile load
3405       // is created with an edge to the load. After optimizations,
3406       // that input may be a chain of Phis. If those phis have no
3407       // other use, then the MemBarAcquire keeps them alive and
3408       // register allocation can be confused.
3409       ResourceMark rm;
3410       Unique_Node_List wq;
3411       wq.push(n->in(MemBarNode::Precedent));
3412       n->set_req(MemBarNode::Precedent, top());
3413       while (wq.size() > 0) {
3414         Node* m = wq.pop();
3415         if (m->outcnt() == 0) {
3416           for (uint j = 0; j < m->req(); j++) {
3417             Node* in = m->in(j);
3418             if (in != NULL) {
3419               wq.push(in);
3420             }
3421           }
3422           m->disconnect_inputs(NULL, this);
3423         }
3424       }
3425     }
3426     break;
3427   }
3428   case Op_RangeCheck: {
3429     RangeCheckNode* rc = n->as_RangeCheck();
3430     Node* iff = new IfNode(rc->in(0), rc->in(1), rc->_prob, rc->_fcnt);
3431     n->subsume_by(iff, this);
3432     frc._tests.push(iff);
3433     break;
3434   }
3435   case Op_ConvI2L: {
3436     if (!Matcher::convi2l_type_required) {
3437       // Code generation on some platforms doesn't need accurate
3438       // ConvI2L types. Widening the type can help remove redundant
3439       // address computations.
3440       n->as_Type()->set_type(TypeLong::INT);
3441       ResourceMark rm;
3442       Node_List wq;
3443       wq.push(n);
3444       for (uint next = 0; next < wq.size(); next++) {
3445         Node *m = wq.at(next);
3446 
3447         for(;;) {
3448           // Loop over all nodes with identical inputs edges as m
3449           Node* k = m->find_similar(m->Opcode());
3450           if (k == NULL) {
3451             break;
3452           }
3453           // Push their uses so we get a chance to remove node made
3454           // redundant
3455           for (DUIterator_Fast imax, i = k->fast_outs(imax); i < imax; i++) {
3456             Node* u = k->fast_out(i);
3457             assert(!wq.contains(u), "shouldn't process one node several times");
3458             if (u->Opcode() == Op_LShiftL ||
3459                 u->Opcode() == Op_AddL ||
3460                 u->Opcode() == Op_SubL ||
3461                 u->Opcode() == Op_AddP) {
3462               wq.push(u);
3463             }
3464           }
3465           // Replace all nodes with identical edges as m with m
3466           k->subsume_by(m, this);
3467         }
3468       }
3469     }
3470     break;
3471   }
3472   case Op_CmpUL: {
3473     if (!Matcher::has_match_rule(Op_CmpUL)) {
3474       // We don't support unsigned long comparisons. Set 'max_idx_expr'
3475       // to max_julong if < 0 to make the signed comparison fail.
3476       ConINode* sign_pos = new ConINode(TypeInt::make(BitsPerLong - 1));
3477       Node* sign_bit_mask = new RShiftLNode(n->in(1), sign_pos);
3478       Node* orl = new OrLNode(n->in(1), sign_bit_mask);
3479       ConLNode* remove_sign_mask = new ConLNode(TypeLong::make(max_jlong));
3480       Node* andl = new AndLNode(orl, remove_sign_mask);
3481       Node* cmp = new CmpLNode(andl, n->in(2));
3482       n->subsume_by(cmp, this);
3483     }
3484     break;
3485   }
3486   default:
3487     assert(!n->is_Call(), "");
3488     assert(!n->is_Mem(), "");
3489     assert(nop != Op_ProfileBoolean, "should be eliminated during IGVN");
3490     break;
3491   }
3492 }
3493 
3494 //------------------------------final_graph_reshaping_walk---------------------
3495 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
3496 // requires that the walk visits a node's inputs before visiting the node.
3497 void Compile::final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Reshape_Counts &frc ) {
3498   ResourceArea *area = Thread::current()->resource_area();
3499   Unique_Node_List sfpt(area);
3500 
3501   frc._visited.set(root->_idx); // first, mark node as visited
3502   uint cnt = root->req();
3503   Node *n = root;
3504   uint  i = 0;
3505   while (true) {
3506     if (i < cnt) {
3507       // Place all non-visited non-null inputs onto stack
3508       Node* m = n->in(i);
3509       ++i;
3510       if (m != NULL && !frc._visited.test_set(m->_idx)) {
3511         if (m->is_SafePoint() && m->as_SafePoint()->jvms() != NULL) {
3512           // compute worst case interpreter size in case of a deoptimization
3513           update_interpreter_frame_size(m->as_SafePoint()->jvms()->interpreter_frame_size());
3514 
3515           sfpt.push(m);
3516         }
3517         cnt = m->req();
3518         nstack.push(n, i); // put on stack parent and next input's index
3519         n = m;
3520         i = 0;
3521       }
3522     } else {
3523       // Now do post-visit work
3524       final_graph_reshaping_impl( n, frc );
3525       if (nstack.is_empty())
3526         break;             // finished
3527       n = nstack.node();   // Get node from stack
3528       cnt = n->req();
3529       i = nstack.index();
3530       nstack.pop();        // Shift to the next node on stack
3531     }
3532   }
3533 
3534   // Skip next transformation if compressed oops are not used.
3535   if ((UseCompressedOops && !Matcher::gen_narrow_oop_implicit_null_checks()) ||
3536       (!UseCompressedOops && !UseCompressedClassPointers))
3537     return;
3538 
3539   // Go over safepoints nodes to skip DecodeN/DecodeNKlass nodes for debug edges.
3540   // It could be done for an uncommon traps or any safepoints/calls
3541   // if the DecodeN/DecodeNKlass node is referenced only in a debug info.
3542   while (sfpt.size() > 0) {
3543     n = sfpt.pop();
3544     JVMState *jvms = n->as_SafePoint()->jvms();
3545     assert(jvms != NULL, "sanity");
3546     int start = jvms->debug_start();
3547     int end   = n->req();
3548     bool is_uncommon = (n->is_CallStaticJava() &&
3549                         n->as_CallStaticJava()->uncommon_trap_request() != 0);
3550     for (int j = start; j < end; j++) {
3551       Node* in = n->in(j);
3552       if (in->is_DecodeNarrowPtr()) {
3553         bool safe_to_skip = true;
3554         if (!is_uncommon ) {
3555           // Is it safe to skip?
3556           for (uint i = 0; i < in->outcnt(); i++) {
3557             Node* u = in->raw_out(i);
3558             if (!u->is_SafePoint() ||
3559                 (u->is_Call() && u->as_Call()->has_non_debug_use(n))) {
3560               safe_to_skip = false;
3561             }
3562           }
3563         }
3564         if (safe_to_skip) {
3565           n->set_req(j, in->in(1));
3566         }
3567         if (in->outcnt() == 0) {
3568           in->disconnect_inputs(NULL, this);
3569         }
3570       }
3571     }
3572   }
3573 }
3574 
3575 //------------------------------final_graph_reshaping--------------------------
3576 // Final Graph Reshaping.
3577 //
3578 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
3579 //     and not commoned up and forced early.  Must come after regular
3580 //     optimizations to avoid GVN undoing the cloning.  Clone constant
3581 //     inputs to Loop Phis; these will be split by the allocator anyways.
3582 //     Remove Opaque nodes.
3583 // (2) Move last-uses by commutative operations to the left input to encourage
3584 //     Intel update-in-place two-address operations and better register usage
3585 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
3586 //     calls canonicalizing them back.
3587 // (3) Count the number of double-precision FP ops, single-precision FP ops
3588 //     and call sites.  On Intel, we can get correct rounding either by
3589 //     forcing singles to memory (requires extra stores and loads after each
3590 //     FP bytecode) or we can set a rounding mode bit (requires setting and
3591 //     clearing the mode bit around call sites).  The mode bit is only used
3592 //     if the relative frequency of single FP ops to calls is low enough.
3593 //     This is a key transform for SPEC mpeg_audio.
3594 // (4) Detect infinite loops; blobs of code reachable from above but not
3595 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
3596 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
3597 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
3598 //     Detection is by looking for IfNodes where only 1 projection is
3599 //     reachable from below or CatchNodes missing some targets.
3600 // (5) Assert for insane oop offsets in debug mode.
3601 
3602 bool Compile::final_graph_reshaping() {
3603   // an infinite loop may have been eliminated by the optimizer,
3604   // in which case the graph will be empty.
3605   if (root()->req() == 1) {
3606     record_method_not_compilable("trivial infinite loop");
3607     return true;
3608   }
3609 
3610   // Expensive nodes have their control input set to prevent the GVN
3611   // from freely commoning them. There's no GVN beyond this point so
3612   // no need to keep the control input. We want the expensive nodes to
3613   // be freely moved to the least frequent code path by gcm.
3614   assert(OptimizeExpensiveOps || expensive_count() == 0, "optimization off but list non empty?");
3615   for (int i = 0; i < expensive_count(); i++) {
3616     _expensive_nodes->at(i)->set_req(0, NULL);
3617   }
3618 
3619   Final_Reshape_Counts frc;
3620 
3621   // Visit everybody reachable!
3622   // Allocate stack of size C->live_nodes()/2 to avoid frequent realloc
3623   Node_Stack nstack(live_nodes() >> 1);
3624   final_graph_reshaping_walk(nstack, root(), frc);
3625 
3626   // Check for unreachable (from below) code (i.e., infinite loops).
3627   for( uint i = 0; i < frc._tests.size(); i++ ) {
3628     MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
3629     // Get number of CFG targets.
3630     // Note that PCTables include exception targets after calls.
3631     uint required_outcnt = n->required_outcnt();
3632     if (n->outcnt() != required_outcnt) {
3633       // Check for a few special cases.  Rethrow Nodes never take the
3634       // 'fall-thru' path, so expected kids is 1 less.
3635       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
3636         if (n->in(0)->in(0)->is_Call()) {
3637           CallNode *call = n->in(0)->in(0)->as_Call();
3638           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
3639             required_outcnt--;      // Rethrow always has 1 less kid
3640           } else if (call->req() > TypeFunc::Parms &&
3641                      call->is_CallDynamicJava()) {
3642             // Check for null receiver. In such case, the optimizer has
3643             // detected that the virtual call will always result in a null
3644             // pointer exception. The fall-through projection of this CatchNode
3645             // will not be populated.
3646             Node *arg0 = call->in(TypeFunc::Parms);
3647             if (arg0->is_Type() &&
3648                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
3649               required_outcnt--;
3650             }
3651           } else if (call->entry_point() == OptoRuntime::new_array_Java() &&
3652                      call->req() > TypeFunc::Parms+1 &&
3653                      call->is_CallStaticJava()) {
3654             // Check for negative array length. In such case, the optimizer has
3655             // detected that the allocation attempt will always result in an
3656             // exception. There is no fall-through projection of this CatchNode .
3657             Node *arg1 = call->in(TypeFunc::Parms+1);
3658             if (arg1->is_Type() &&
3659                 arg1->as_Type()->type()->join(TypeInt::POS)->empty()) {
3660               required_outcnt--;
3661             }
3662           }
3663         }
3664       }
3665       // Recheck with a better notion of 'required_outcnt'
3666       if (n->outcnt() != required_outcnt) {
3667         record_method_not_compilable("malformed control flow");
3668         return true;            // Not all targets reachable!
3669       }
3670     }
3671     // Check that I actually visited all kids.  Unreached kids
3672     // must be infinite loops.
3673     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
3674       if (!frc._visited.test(n->fast_out(j)->_idx)) {
3675         record_method_not_compilable("infinite loop");
3676         return true;            // Found unvisited kid; must be unreach
3677       }
3678 
3679     // Here so verification code in final_graph_reshaping_walk()
3680     // always see an OuterStripMinedLoopEnd
3681     if (n->is_OuterStripMinedLoopEnd()) {
3682       IfNode* init_iff = n->as_If();
3683       Node* iff = new IfNode(init_iff->in(0), init_iff->in(1), init_iff->_prob, init_iff->_fcnt);
3684       n->subsume_by(iff, this);
3685     }
3686   }
3687 
3688   // If original bytecodes contained a mixture of floats and doubles
3689   // check if the optimizer has made it homogenous, item (3).
3690   if( Use24BitFPMode && Use24BitFP && UseSSE == 0 &&
3691       frc.get_float_count() > 32 &&
3692       frc.get_double_count() == 0 &&
3693       (10 * frc.get_call_count() < frc.get_float_count()) ) {
3694     set_24_bit_selection_and_mode( false,  true );
3695   }
3696 
3697   set_java_calls(frc.get_java_call_count());
3698   set_inner_loops(frc.get_inner_loop_count());
3699 
3700   // No infinite loops, no reason to bail out.
3701   return false;
3702 }
3703 
3704 //-----------------------------too_many_traps----------------------------------
3705 // Report if there are too many traps at the current method and bci.
3706 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
3707 bool Compile::too_many_traps(ciMethod* method,
3708                              int bci,
3709                              Deoptimization::DeoptReason reason) {
3710   ciMethodData* md = method->method_data();
3711   if (md->is_empty()) {
3712     // Assume the trap has not occurred, or that it occurred only
3713     // because of a transient condition during start-up in the interpreter.
3714     return false;
3715   }
3716   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
3717   if (md->has_trap_at(bci, m, reason) != 0) {
3718     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
3719     // Also, if there are multiple reasons, or if there is no per-BCI record,
3720     // assume the worst.
3721     if (log())
3722       log()->elem("observe trap='%s' count='%d'",
3723                   Deoptimization::trap_reason_name(reason),
3724                   md->trap_count(reason));
3725     return true;
3726   } else {
3727     // Ignore method/bci and see if there have been too many globally.
3728     return too_many_traps(reason, md);
3729   }
3730 }
3731 
3732 // Less-accurate variant which does not require a method and bci.
3733 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
3734                              ciMethodData* logmd) {
3735   if (trap_count(reason) >= Deoptimization::per_method_trap_limit(reason)) {
3736     // Too many traps globally.
3737     // Note that we use cumulative trap_count, not just md->trap_count.
3738     if (log()) {
3739       int mcount = (logmd == NULL)? -1: (int)logmd->trap_count(reason);
3740       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
3741                   Deoptimization::trap_reason_name(reason),
3742                   mcount, trap_count(reason));
3743     }
3744     return true;
3745   } else {
3746     // The coast is clear.
3747     return false;
3748   }
3749 }
3750 
3751 //--------------------------too_many_recompiles--------------------------------
3752 // Report if there are too many recompiles at the current method and bci.
3753 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
3754 // Is not eager to return true, since this will cause the compiler to use
3755 // Action_none for a trap point, to avoid too many recompilations.
3756 bool Compile::too_many_recompiles(ciMethod* method,
3757                                   int bci,
3758                                   Deoptimization::DeoptReason reason) {
3759   ciMethodData* md = method->method_data();
3760   if (md->is_empty()) {
3761     // Assume the trap has not occurred, or that it occurred only
3762     // because of a transient condition during start-up in the interpreter.
3763     return false;
3764   }
3765   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
3766   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
3767   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
3768   Deoptimization::DeoptReason per_bc_reason
3769     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
3770   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
3771   if ((per_bc_reason == Deoptimization::Reason_none
3772        || md->has_trap_at(bci, m, reason) != 0)
3773       // The trap frequency measure we care about is the recompile count:
3774       && md->trap_recompiled_at(bci, m)
3775       && md->overflow_recompile_count() >= bc_cutoff) {
3776     // Do not emit a trap here if it has already caused recompilations.
3777     // Also, if there are multiple reasons, or if there is no per-BCI record,
3778     // assume the worst.
3779     if (log())
3780       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
3781                   Deoptimization::trap_reason_name(reason),
3782                   md->trap_count(reason),
3783                   md->overflow_recompile_count());
3784     return true;
3785   } else if (trap_count(reason) != 0
3786              && decompile_count() >= m_cutoff) {
3787     // Too many recompiles globally, and we have seen this sort of trap.
3788     // Use cumulative decompile_count, not just md->decompile_count.
3789     if (log())
3790       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
3791                   Deoptimization::trap_reason_name(reason),
3792                   md->trap_count(reason), trap_count(reason),
3793                   md->decompile_count(), decompile_count());
3794     return true;
3795   } else {
3796     // The coast is clear.
3797     return false;
3798   }
3799 }
3800 
3801 // Compute when not to trap. Used by matching trap based nodes and
3802 // NullCheck optimization.
3803 void Compile::set_allowed_deopt_reasons() {
3804   _allowed_reasons = 0;
3805   if (is_method_compilation()) {
3806     for (int rs = (int)Deoptimization::Reason_none+1; rs < Compile::trapHistLength; rs++) {
3807       assert(rs < BitsPerInt, "recode bit map");
3808       if (!too_many_traps((Deoptimization::DeoptReason) rs)) {
3809         _allowed_reasons |= nth_bit(rs);
3810       }
3811     }
3812   }
3813 }
3814 
3815 #ifndef PRODUCT
3816 //------------------------------verify_graph_edges---------------------------
3817 // Walk the Graph and verify that there is a one-to-one correspondence
3818 // between Use-Def edges and Def-Use edges in the graph.
3819 void Compile::verify_graph_edges(bool no_dead_code) {
3820   if (VerifyGraphEdges) {
3821     ResourceArea *area = Thread::current()->resource_area();
3822     Unique_Node_List visited(area);
3823     // Call recursive graph walk to check edges
3824     _root->verify_edges(visited);
3825     if (no_dead_code) {
3826       // Now make sure that no visited node is used by an unvisited node.
3827       bool dead_nodes = false;
3828       Unique_Node_List checked(area);
3829       while (visited.size() > 0) {
3830         Node* n = visited.pop();
3831         checked.push(n);
3832         for (uint i = 0; i < n->outcnt(); i++) {
3833           Node* use = n->raw_out(i);
3834           if (checked.member(use))  continue;  // already checked
3835           if (visited.member(use))  continue;  // already in the graph
3836           if (use->is_Con())        continue;  // a dead ConNode is OK
3837           // At this point, we have found a dead node which is DU-reachable.
3838           if (!dead_nodes) {
3839             tty->print_cr("*** Dead nodes reachable via DU edges:");
3840             dead_nodes = true;
3841           }
3842           use->dump(2);
3843           tty->print_cr("---");
3844           checked.push(use);  // No repeats; pretend it is now checked.
3845         }
3846       }
3847       assert(!dead_nodes, "using nodes must be reachable from root");
3848     }
3849   }
3850 }
3851 #endif
3852 
3853 // The Compile object keeps track of failure reasons separately from the ciEnv.
3854 // This is required because there is not quite a 1-1 relation between the
3855 // ciEnv and its compilation task and the Compile object.  Note that one
3856 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
3857 // to backtrack and retry without subsuming loads.  Other than this backtracking
3858 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
3859 // by the logic in C2Compiler.
3860 void Compile::record_failure(const char* reason) {
3861   if (log() != NULL) {
3862     log()->elem("failure reason='%s' phase='compile'", reason);
3863   }
3864   if (_failure_reason == NULL) {
3865     // Record the first failure reason.
3866     _failure_reason = reason;
3867   }
3868 
3869   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
3870     C->print_method(PHASE_FAILURE);
3871   }
3872   _root = NULL;  // flush the graph, too
3873 }
3874 
3875 Compile::TracePhase::TracePhase(const char* name, elapsedTimer* accumulator)
3876   : TraceTime(name, accumulator, CITime, CITimeVerbose),
3877     _phase_name(name), _dolog(CITimeVerbose)
3878 {
3879   if (_dolog) {
3880     C = Compile::current();
3881     _log = C->log();
3882   } else {
3883     C = NULL;
3884     _log = NULL;
3885   }
3886   if (_log != NULL) {
3887     _log->begin_head("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
3888     _log->stamp();
3889     _log->end_head();
3890   }
3891 }
3892 
3893 Compile::TracePhase::~TracePhase() {
3894 
3895   C = Compile::current();
3896   if (_dolog) {
3897     _log = C->log();
3898   } else {
3899     _log = NULL;
3900   }
3901 
3902 #ifdef ASSERT
3903   if (PrintIdealNodeCount) {
3904     tty->print_cr("phase name='%s' nodes='%d' live='%d' live_graph_walk='%d'",
3905                   _phase_name, C->unique(), C->live_nodes(), C->count_live_nodes_by_graph_walk());
3906   }
3907 
3908   if (VerifyIdealNodeCount) {
3909     Compile::current()->print_missing_nodes();
3910   }
3911 #endif
3912 
3913   if (_log != NULL) {
3914     _log->done("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
3915   }
3916 }
3917 
3918 //=============================================================================
3919 // Two Constant's are equal when the type and the value are equal.
3920 bool Compile::Constant::operator==(const Constant& other) {
3921   if (type()          != other.type()         )  return false;
3922   if (can_be_reused() != other.can_be_reused())  return false;
3923   // For floating point values we compare the bit pattern.
3924   switch (type()) {
3925   case T_INT:
3926   case T_FLOAT:   return (_v._value.i == other._v._value.i);
3927   case T_LONG:
3928   case T_DOUBLE:  return (_v._value.j == other._v._value.j);
3929   case T_OBJECT:
3930   case T_ADDRESS: return (_v._value.l == other._v._value.l);
3931   case T_VOID:    return (_v._value.l == other._v._value.l);  // jump-table entries
3932   case T_METADATA: return (_v._metadata == other._v._metadata);
3933   default: ShouldNotReachHere(); return false;
3934   }
3935 }
3936 
3937 static int type_to_size_in_bytes(BasicType t) {
3938   switch (t) {
3939   case T_INT:     return sizeof(jint   );
3940   case T_LONG:    return sizeof(jlong  );
3941   case T_FLOAT:   return sizeof(jfloat );
3942   case T_DOUBLE:  return sizeof(jdouble);
3943   case T_METADATA: return sizeof(Metadata*);
3944     // We use T_VOID as marker for jump-table entries (labels) which
3945     // need an internal word relocation.
3946   case T_VOID:
3947   case T_ADDRESS:
3948   case T_OBJECT:  return sizeof(jobject);
3949   default:
3950     ShouldNotReachHere();
3951     return -1;
3952   }
3953 }
3954 
3955 int Compile::ConstantTable::qsort_comparator(Constant* a, Constant* b) {
3956   // sort descending
3957   if (a->freq() > b->freq())  return -1;
3958   if (a->freq() < b->freq())  return  1;
3959   return 0;
3960 }
3961 
3962 void Compile::ConstantTable::calculate_offsets_and_size() {
3963   // First, sort the array by frequencies.
3964   _constants.sort(qsort_comparator);
3965 
3966 #ifdef ASSERT
3967   // Make sure all jump-table entries were sorted to the end of the
3968   // array (they have a negative frequency).
3969   bool found_void = false;
3970   for (int i = 0; i < _constants.length(); i++) {
3971     Constant con = _constants.at(i);
3972     if (con.type() == T_VOID)
3973       found_void = true;  // jump-tables
3974     else
3975       assert(!found_void, "wrong sorting");
3976   }
3977 #endif
3978 
3979   int offset = 0;
3980   for (int i = 0; i < _constants.length(); i++) {
3981     Constant* con = _constants.adr_at(i);
3982 
3983     // Align offset for type.
3984     int typesize = type_to_size_in_bytes(con->type());
3985     offset = align_up(offset, typesize);
3986     con->set_offset(offset);   // set constant's offset
3987 
3988     if (con->type() == T_VOID) {
3989       MachConstantNode* n = (MachConstantNode*) con->get_jobject();
3990       offset = offset + typesize * n->outcnt();  // expand jump-table
3991     } else {
3992       offset = offset + typesize;
3993     }
3994   }
3995 
3996   // Align size up to the next section start (which is insts; see
3997   // CodeBuffer::align_at_start).
3998   assert(_size == -1, "already set?");
3999   _size = align_up(offset, (int)CodeEntryAlignment);
4000 }
4001 
4002 void Compile::ConstantTable::emit(CodeBuffer& cb) {
4003   MacroAssembler _masm(&cb);
4004   for (int i = 0; i < _constants.length(); i++) {
4005     Constant con = _constants.at(i);
4006     address constant_addr = NULL;
4007     switch (con.type()) {
4008     case T_INT:    constant_addr = _masm.int_constant(   con.get_jint()   ); break;
4009     case T_LONG:   constant_addr = _masm.long_constant(  con.get_jlong()  ); break;
4010     case T_FLOAT:  constant_addr = _masm.float_constant( con.get_jfloat() ); break;
4011     case T_DOUBLE: constant_addr = _masm.double_constant(con.get_jdouble()); break;
4012     case T_OBJECT: {
4013       jobject obj = con.get_jobject();
4014       int oop_index = _masm.oop_recorder()->find_index(obj);
4015       constant_addr = _masm.address_constant((address) obj, oop_Relocation::spec(oop_index));
4016       break;
4017     }
4018     case T_ADDRESS: {
4019       address addr = (address) con.get_jobject();
4020       constant_addr = _masm.address_constant(addr);
4021       break;
4022     }
4023     // We use T_VOID as marker for jump-table entries (labels) which
4024     // need an internal word relocation.
4025     case T_VOID: {
4026       MachConstantNode* n = (MachConstantNode*) con.get_jobject();
4027       // Fill the jump-table with a dummy word.  The real value is
4028       // filled in later in fill_jump_table.
4029       address dummy = (address) n;
4030       constant_addr = _masm.address_constant(dummy);
4031       // Expand jump-table
4032       for (uint i = 1; i < n->outcnt(); i++) {
4033         address temp_addr = _masm.address_constant(dummy + i);
4034         assert(temp_addr, "consts section too small");
4035       }
4036       break;
4037     }
4038     case T_METADATA: {
4039       Metadata* obj = con.get_metadata();
4040       int metadata_index = _masm.oop_recorder()->find_index(obj);
4041       constant_addr = _masm.address_constant((address) obj, metadata_Relocation::spec(metadata_index));
4042       break;
4043     }
4044     default: ShouldNotReachHere();
4045     }
4046     assert(constant_addr, "consts section too small");
4047     assert((constant_addr - _masm.code()->consts()->start()) == con.offset(),
4048             "must be: %d == %d", (int) (constant_addr - _masm.code()->consts()->start()), (int)(con.offset()));
4049   }
4050 }
4051 
4052 int Compile::ConstantTable::find_offset(Constant& con) const {
4053   int idx = _constants.find(con);
4054   guarantee(idx != -1, "constant must be in constant table");
4055   int offset = _constants.at(idx).offset();
4056   guarantee(offset != -1, "constant table not emitted yet?");
4057   return offset;
4058 }
4059 
4060 void Compile::ConstantTable::add(Constant& con) {
4061   if (con.can_be_reused()) {
4062     int idx = _constants.find(con);
4063     if (idx != -1 && _constants.at(idx).can_be_reused()) {
4064       _constants.adr_at(idx)->inc_freq(con.freq());  // increase the frequency by the current value
4065       return;
4066     }
4067   }
4068   (void) _constants.append(con);
4069 }
4070 
4071 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, BasicType type, jvalue value) {
4072   Block* b = Compile::current()->cfg()->get_block_for_node(n);
4073   Constant con(type, value, b->_freq);
4074   add(con);
4075   return con;
4076 }
4077 
4078 Compile::Constant Compile::ConstantTable::add(Metadata* metadata) {
4079   Constant con(metadata);
4080   add(con);
4081   return con;
4082 }
4083 
4084 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, MachOper* oper) {
4085   jvalue value;
4086   BasicType type = oper->type()->basic_type();
4087   switch (type) {
4088   case T_LONG:    value.j = oper->constantL(); break;
4089   case T_FLOAT:   value.f = oper->constantF(); break;
4090   case T_DOUBLE:  value.d = oper->constantD(); break;
4091   case T_OBJECT:
4092   case T_ADDRESS: value.l = (jobject) oper->constant(); break;
4093   case T_METADATA: return add((Metadata*)oper->constant()); break;
4094   default: guarantee(false, "unhandled type: %s", type2name(type));
4095   }
4096   return add(n, type, value);
4097 }
4098 
4099 Compile::Constant Compile::ConstantTable::add_jump_table(MachConstantNode* n) {
4100   jvalue value;
4101   // We can use the node pointer here to identify the right jump-table
4102   // as this method is called from Compile::Fill_buffer right before
4103   // the MachNodes are emitted and the jump-table is filled (means the
4104   // MachNode pointers do not change anymore).
4105   value.l = (jobject) n;
4106   Constant con(T_VOID, value, next_jump_table_freq(), false);  // Labels of a jump-table cannot be reused.
4107   add(con);
4108   return con;
4109 }
4110 
4111 void Compile::ConstantTable::fill_jump_table(CodeBuffer& cb, MachConstantNode* n, GrowableArray<Label*> labels) const {
4112   // If called from Compile::scratch_emit_size do nothing.
4113   if (Compile::current()->in_scratch_emit_size())  return;
4114 
4115   assert(labels.is_nonempty(), "must be");
4116   assert((uint) labels.length() == n->outcnt(), "must be equal: %d == %d", labels.length(), n->outcnt());
4117 
4118   // Since MachConstantNode::constant_offset() also contains
4119   // table_base_offset() we need to subtract the table_base_offset()
4120   // to get the plain offset into the constant table.
4121   int offset = n->constant_offset() - table_base_offset();
4122 
4123   MacroAssembler _masm(&cb);
4124   address* jump_table_base = (address*) (_masm.code()->consts()->start() + offset);
4125 
4126   for (uint i = 0; i < n->outcnt(); i++) {
4127     address* constant_addr = &jump_table_base[i];
4128     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));
4129     *constant_addr = cb.consts()->target(*labels.at(i), (address) constant_addr);
4130     cb.consts()->relocate((address) constant_addr, relocInfo::internal_word_type);
4131   }
4132 }
4133 
4134 //----------------------------static_subtype_check-----------------------------
4135 // Shortcut important common cases when superklass is exact:
4136 // (0) superklass is java.lang.Object (can occur in reflective code)
4137 // (1) subklass is already limited to a subtype of superklass => always ok
4138 // (2) subklass does not overlap with superklass => always fail
4139 // (3) superklass has NO subtypes and we can check with a simple compare.
4140 int Compile::static_subtype_check(ciKlass* superk, ciKlass* subk) {
4141   if (StressReflectiveCode) {
4142     return SSC_full_test;       // Let caller generate the general case.
4143   }
4144 
4145   if (superk == env()->Object_klass()) {
4146     return SSC_always_true;     // (0) this test cannot fail
4147   }
4148 
4149   ciType* superelem = superk;
4150   if (superelem->is_array_klass())
4151     superelem = superelem->as_array_klass()->base_element_type();
4152 
4153   if (!subk->is_interface()) {  // cannot trust static interface types yet
4154     if (subk->is_subtype_of(superk)) {
4155       return SSC_always_true;   // (1) false path dead; no dynamic test needed
4156     }
4157     if (!(superelem->is_klass() && superelem->as_klass()->is_interface()) &&
4158         !superk->is_subtype_of(subk)) {
4159       return SSC_always_false;
4160     }
4161   }
4162 
4163   // If casting to an instance klass, it must have no subtypes
4164   if (superk->is_interface()) {
4165     // Cannot trust interfaces yet.
4166     // %%% S.B. superk->nof_implementors() == 1
4167   } else if (superelem->is_instance_klass()) {
4168     ciInstanceKlass* ik = superelem->as_instance_klass();
4169     if (!ik->has_subklass() && !ik->is_interface()) {
4170       if (!ik->is_final()) {
4171         // Add a dependency if there is a chance of a later subclass.
4172         dependencies()->assert_leaf_type(ik);
4173       }
4174       return SSC_easy_test;     // (3) caller can do a simple ptr comparison
4175     }
4176   } else {
4177     // A primitive array type has no subtypes.
4178     return SSC_easy_test;       // (3) caller can do a simple ptr comparison
4179   }
4180 
4181   return SSC_full_test;
4182 }
4183 
4184 Node* Compile::conv_I2X_index(PhaseGVN* phase, Node* idx, const TypeInt* sizetype, Node* ctrl) {
4185 #ifdef _LP64
4186   // The scaled index operand to AddP must be a clean 64-bit value.
4187   // Java allows a 32-bit int to be incremented to a negative
4188   // value, which appears in a 64-bit register as a large
4189   // positive number.  Using that large positive number as an
4190   // operand in pointer arithmetic has bad consequences.
4191   // On the other hand, 32-bit overflow is rare, and the possibility
4192   // can often be excluded, if we annotate the ConvI2L node with
4193   // a type assertion that its value is known to be a small positive
4194   // number.  (The prior range check has ensured this.)
4195   // This assertion is used by ConvI2LNode::Ideal.
4196   int index_max = max_jint - 1;  // array size is max_jint, index is one less
4197   if (sizetype != NULL) index_max = sizetype->_hi - 1;
4198   const TypeInt* iidxtype = TypeInt::make(0, index_max, Type::WidenMax);
4199   idx = constrained_convI2L(phase, idx, iidxtype, ctrl);
4200 #endif
4201   return idx;
4202 }
4203 
4204 // Convert integer value to a narrowed long type dependent on ctrl (for example, a range check)
4205 Node* Compile::constrained_convI2L(PhaseGVN* phase, Node* value, const TypeInt* itype, Node* ctrl) {
4206   if (ctrl != NULL) {
4207     // Express control dependency by a CastII node with a narrow type.
4208     value = new CastIINode(value, itype, false, true /* range check dependency */);
4209     // Make the CastII node dependent on the control input to prevent the narrowed ConvI2L
4210     // node from floating above the range check during loop optimizations. Otherwise, the
4211     // ConvI2L node may be eliminated independently of the range check, causing the data path
4212     // to become TOP while the control path is still there (although it's unreachable).
4213     value->set_req(0, ctrl);
4214     // Save CastII node to remove it after loop optimizations.
4215     phase->C->add_range_check_cast(value);
4216     value = phase->transform(value);
4217   }
4218   const TypeLong* ltype = TypeLong::make(itype->_lo, itype->_hi, itype->_widen);
4219   return phase->transform(new ConvI2LNode(value, ltype));
4220 }
4221 
4222 // The message about the current inlining is accumulated in
4223 // _print_inlining_stream and transfered into the _print_inlining_list
4224 // once we know whether inlining succeeds or not. For regular
4225 // inlining, messages are appended to the buffer pointed by
4226 // _print_inlining_idx in the _print_inlining_list. For late inlining,
4227 // a new buffer is added after _print_inlining_idx in the list. This
4228 // way we can update the inlining message for late inlining call site
4229 // when the inlining is attempted again.
4230 void Compile::print_inlining_init() {
4231   if (print_inlining() || print_intrinsics()) {
4232     _print_inlining_stream = new stringStream();
4233     _print_inlining_list = new (comp_arena())GrowableArray<PrintInliningBuffer>(comp_arena(), 1, 1, PrintInliningBuffer());
4234   }
4235 }
4236 
4237 void Compile::print_inlining_reinit() {
4238   if (print_inlining() || print_intrinsics()) {
4239     // Re allocate buffer when we change ResourceMark
4240     _print_inlining_stream = new stringStream();
4241   }
4242 }
4243 
4244 void Compile::print_inlining_reset() {
4245   _print_inlining_stream->reset();
4246 }
4247 
4248 void Compile::print_inlining_commit() {
4249   assert(print_inlining() || print_intrinsics(), "PrintInlining off?");
4250   // Transfer the message from _print_inlining_stream to the current
4251   // _print_inlining_list buffer and clear _print_inlining_stream.
4252   _print_inlining_list->at(_print_inlining_idx).ss()->write(_print_inlining_stream->as_string(), _print_inlining_stream->size());
4253   print_inlining_reset();
4254 }
4255 
4256 void Compile::print_inlining_push() {
4257   // Add new buffer to the _print_inlining_list at current position
4258   _print_inlining_idx++;
4259   _print_inlining_list->insert_before(_print_inlining_idx, PrintInliningBuffer());
4260 }
4261 
4262 Compile::PrintInliningBuffer& Compile::print_inlining_current() {
4263   return _print_inlining_list->at(_print_inlining_idx);
4264 }
4265 
4266 void Compile::print_inlining_update(CallGenerator* cg) {
4267   if (print_inlining() || print_intrinsics()) {
4268     if (!cg->is_late_inline()) {
4269       if (print_inlining_current().cg() != NULL) {
4270         print_inlining_push();
4271       }
4272       print_inlining_commit();
4273     } else {
4274       if (print_inlining_current().cg() != cg &&
4275           (print_inlining_current().cg() != NULL ||
4276            print_inlining_current().ss()->size() != 0)) {
4277         print_inlining_push();
4278       }
4279       print_inlining_commit();
4280       print_inlining_current().set_cg(cg);
4281     }
4282   }
4283 }
4284 
4285 void Compile::print_inlining_move_to(CallGenerator* cg) {
4286   // We resume inlining at a late inlining call site. Locate the
4287   // corresponding inlining buffer so that we can update it.
4288   if (print_inlining()) {
4289     for (int i = 0; i < _print_inlining_list->length(); i++) {
4290       if (_print_inlining_list->adr_at(i)->cg() == cg) {
4291         _print_inlining_idx = i;
4292         return;
4293       }
4294     }
4295     ShouldNotReachHere();
4296   }
4297 }
4298 
4299 void Compile::print_inlining_update_delayed(CallGenerator* cg) {
4300   if (print_inlining()) {
4301     assert(_print_inlining_stream->size() > 0, "missing inlining msg");
4302     assert(print_inlining_current().cg() == cg, "wrong entry");
4303     // replace message with new message
4304     _print_inlining_list->at_put(_print_inlining_idx, PrintInliningBuffer());
4305     print_inlining_commit();
4306     print_inlining_current().set_cg(cg);
4307   }
4308 }
4309 
4310 void Compile::print_inlining_assert_ready() {
4311   assert(!_print_inlining || _print_inlining_stream->size() == 0, "loosing data");
4312 }
4313 
4314 void Compile::process_print_inlining() {
4315   bool do_print_inlining = print_inlining() || print_intrinsics();
4316   if (do_print_inlining || log() != NULL) {
4317     // Print inlining message for candidates that we couldn't inline
4318     // for lack of space
4319     for (int i = 0; i < _late_inlines.length(); i++) {
4320       CallGenerator* cg = _late_inlines.at(i);
4321       if (!cg->is_mh_late_inline()) {
4322         const char* msg = "live nodes > LiveNodeCountInliningCutoff";
4323         if (do_print_inlining) {
4324           cg->print_inlining_late(msg);
4325         }
4326         log_late_inline_failure(cg, msg);
4327       }
4328     }
4329   }
4330   if (do_print_inlining) {
4331     ResourceMark rm;
4332     stringStream ss;
4333     for (int i = 0; i < _print_inlining_list->length(); i++) {
4334       ss.print("%s", _print_inlining_list->adr_at(i)->ss()->as_string());
4335     }
4336     size_t end = ss.size();
4337     _print_inlining_output = NEW_ARENA_ARRAY(comp_arena(), char, end+1);
4338     strncpy(_print_inlining_output, ss.base(), end+1);
4339     _print_inlining_output[end] = 0;
4340   }
4341 }
4342 
4343 void Compile::dump_print_inlining() {
4344   if (_print_inlining_output != NULL) {
4345     tty->print_raw(_print_inlining_output);
4346   }
4347 }
4348 
4349 void Compile::log_late_inline(CallGenerator* cg) {
4350   if (log() != NULL) {
4351     log()->head("late_inline method='%d'  inline_id='" JLONG_FORMAT "'", log()->identify(cg->method()),
4352                 cg->unique_id());
4353     JVMState* p = cg->call_node()->jvms();
4354     while (p != NULL) {
4355       log()->elem("jvms bci='%d' method='%d'", p->bci(), log()->identify(p->method()));
4356       p = p->caller();
4357     }
4358     log()->tail("late_inline");
4359   }
4360 }
4361 
4362 void Compile::log_late_inline_failure(CallGenerator* cg, const char* msg) {
4363   log_late_inline(cg);
4364   if (log() != NULL) {
4365     log()->inline_fail(msg);
4366   }
4367 }
4368 
4369 void Compile::log_inline_id(CallGenerator* cg) {
4370   if (log() != NULL) {
4371     // The LogCompilation tool needs a unique way to identify late
4372     // inline call sites. This id must be unique for this call site in
4373     // this compilation. Try to have it unique across compilations as
4374     // well because it can be convenient when grepping through the log
4375     // file.
4376     // Distinguish OSR compilations from others in case CICountOSR is
4377     // on.
4378     jlong id = ((jlong)unique()) + (((jlong)compile_id()) << 33) + (CICountOSR && is_osr_compilation() ? ((jlong)1) << 32 : 0);
4379     cg->set_unique_id(id);
4380     log()->elem("inline_id id='" JLONG_FORMAT "'", id);
4381   }
4382 }
4383 
4384 void Compile::log_inline_failure(const char* msg) {
4385   if (C->log() != NULL) {
4386     C->log()->inline_fail(msg);
4387   }
4388 }
4389 
4390 
4391 // Dump inlining replay data to the stream.
4392 // Don't change thread state and acquire any locks.
4393 void Compile::dump_inline_data(outputStream* out) {
4394   InlineTree* inl_tree = ilt();
4395   if (inl_tree != NULL) {
4396     out->print(" inline %d", inl_tree->count());
4397     inl_tree->dump_replay_data(out);
4398   }
4399 }
4400 
4401 int Compile::cmp_expensive_nodes(Node* n1, Node* n2) {
4402   if (n1->Opcode() < n2->Opcode())      return -1;
4403   else if (n1->Opcode() > n2->Opcode()) return 1;
4404 
4405   assert(n1->req() == n2->req(), "can't compare %s nodes: n1->req() = %d, n2->req() = %d", NodeClassNames[n1->Opcode()], n1->req(), n2->req());
4406   for (uint i = 1; i < n1->req(); i++) {
4407     if (n1->in(i) < n2->in(i))      return -1;
4408     else if (n1->in(i) > n2->in(i)) return 1;
4409   }
4410 
4411   return 0;
4412 }
4413 
4414 int Compile::cmp_expensive_nodes(Node** n1p, Node** n2p) {
4415   Node* n1 = *n1p;
4416   Node* n2 = *n2p;
4417 
4418   return cmp_expensive_nodes(n1, n2);
4419 }
4420 
4421 void Compile::sort_expensive_nodes() {
4422   if (!expensive_nodes_sorted()) {
4423     _expensive_nodes->sort(cmp_expensive_nodes);
4424   }
4425 }
4426 
4427 bool Compile::expensive_nodes_sorted() const {
4428   for (int i = 1; i < _expensive_nodes->length(); i++) {
4429     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i-1)) < 0) {
4430       return false;
4431     }
4432   }
4433   return true;
4434 }
4435 
4436 bool Compile::should_optimize_expensive_nodes(PhaseIterGVN &igvn) {
4437   if (_expensive_nodes->length() == 0) {
4438     return false;
4439   }
4440 
4441   assert(OptimizeExpensiveOps, "optimization off?");
4442 
4443   // Take this opportunity to remove dead nodes from the list
4444   int j = 0;
4445   for (int i = 0; i < _expensive_nodes->length(); i++) {
4446     Node* n = _expensive_nodes->at(i);
4447     if (!n->is_unreachable(igvn)) {
4448       assert(n->is_expensive(), "should be expensive");
4449       _expensive_nodes->at_put(j, n);
4450       j++;
4451     }
4452   }
4453   _expensive_nodes->trunc_to(j);
4454 
4455   // Then sort the list so that similar nodes are next to each other
4456   // and check for at least two nodes of identical kind with same data
4457   // inputs.
4458   sort_expensive_nodes();
4459 
4460   for (int i = 0; i < _expensive_nodes->length()-1; i++) {
4461     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i+1)) == 0) {
4462       return true;
4463     }
4464   }
4465 
4466   return false;
4467 }
4468 
4469 void Compile::cleanup_expensive_nodes(PhaseIterGVN &igvn) {
4470   if (_expensive_nodes->length() == 0) {
4471     return;
4472   }
4473 
4474   assert(OptimizeExpensiveOps, "optimization off?");
4475 
4476   // Sort to bring similar nodes next to each other and clear the
4477   // control input of nodes for which there's only a single copy.
4478   sort_expensive_nodes();
4479 
4480   int j = 0;
4481   int identical = 0;
4482   int i = 0;
4483   bool modified = false;
4484   for (; i < _expensive_nodes->length()-1; i++) {
4485     assert(j <= i, "can't write beyond current index");
4486     if (_expensive_nodes->at(i)->Opcode() == _expensive_nodes->at(i+1)->Opcode()) {
4487       identical++;
4488       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4489       continue;
4490     }
4491     if (identical > 0) {
4492       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4493       identical = 0;
4494     } else {
4495       Node* n = _expensive_nodes->at(i);
4496       igvn.replace_input_of(n, 0, NULL);
4497       igvn.hash_insert(n);
4498       modified = true;
4499     }
4500   }
4501   if (identical > 0) {
4502     _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4503   } else if (_expensive_nodes->length() >= 1) {
4504     Node* n = _expensive_nodes->at(i);
4505     igvn.replace_input_of(n, 0, NULL);
4506     igvn.hash_insert(n);
4507     modified = true;
4508   }
4509   _expensive_nodes->trunc_to(j);
4510   if (modified) {
4511     igvn.optimize();
4512   }
4513 }
4514 
4515 void Compile::add_expensive_node(Node * n) {
4516   assert(!_expensive_nodes->contains(n), "duplicate entry in expensive list");
4517   assert(n->is_expensive(), "expensive nodes with non-null control here only");
4518   assert(!n->is_CFG() && !n->is_Mem(), "no cfg or memory nodes here");
4519   if (OptimizeExpensiveOps) {
4520     _expensive_nodes->append(n);
4521   } else {
4522     // Clear control input and let IGVN optimize expensive nodes if
4523     // OptimizeExpensiveOps is off.
4524     n->set_req(0, NULL);
4525   }
4526 }
4527 
4528 /**
4529  * Remove the speculative part of types and clean up the graph
4530  */
4531 void Compile::remove_speculative_types(PhaseIterGVN &igvn) {
4532   if (UseTypeSpeculation) {
4533     Unique_Node_List worklist;
4534     worklist.push(root());
4535     int modified = 0;
4536     // Go over all type nodes that carry a speculative type, drop the
4537     // speculative part of the type and enqueue the node for an igvn
4538     // which may optimize it out.
4539     for (uint next = 0; next < worklist.size(); ++next) {
4540       Node *n  = worklist.at(next);
4541       if (n->is_Type()) {
4542         TypeNode* tn = n->as_Type();
4543         const Type* t = tn->type();
4544         const Type* t_no_spec = t->remove_speculative();
4545         if (t_no_spec != t) {
4546           bool in_hash = igvn.hash_delete(n);
4547           assert(in_hash, "node should be in igvn hash table");
4548           tn->set_type(t_no_spec);
4549           igvn.hash_insert(n);
4550           igvn._worklist.push(n); // give it a chance to go away
4551           modified++;
4552         }
4553       }
4554       uint max = n->len();
4555       for( uint i = 0; i < max; ++i ) {
4556         Node *m = n->in(i);
4557         if (not_a_node(m))  continue;
4558         worklist.push(m);
4559       }
4560     }
4561     // Drop the speculative part of all types in the igvn's type table
4562     igvn.remove_speculative_types();
4563     if (modified > 0) {
4564       igvn.optimize();
4565     }
4566 #ifdef ASSERT
4567     // Verify that after the IGVN is over no speculative type has resurfaced
4568     worklist.clear();
4569     worklist.push(root());
4570     for (uint next = 0; next < worklist.size(); ++next) {
4571       Node *n  = worklist.at(next);
4572       const Type* t = igvn.type_or_null(n);
4573       assert((t == NULL) || (t == t->remove_speculative()), "no more speculative types");
4574       if (n->is_Type()) {
4575         t = n->as_Type()->type();
4576         assert(t == t->remove_speculative(), "no more speculative types");
4577       }
4578       uint max = n->len();
4579       for( uint i = 0; i < max; ++i ) {
4580         Node *m = n->in(i);
4581         if (not_a_node(m))  continue;
4582         worklist.push(m);
4583       }
4584     }
4585     igvn.check_no_speculative_types();
4586 #endif
4587   }
4588 }
4589 
4590 // Auxiliary method to support randomized stressing/fuzzing.
4591 //
4592 // This method can be called the arbitrary number of times, with current count
4593 // as the argument. The logic allows selecting a single candidate from the
4594 // running list of candidates as follows:
4595 //    int count = 0;
4596 //    Cand* selected = null;
4597 //    while(cand = cand->next()) {
4598 //      if (randomized_select(++count)) {
4599 //        selected = cand;
4600 //      }
4601 //    }
4602 //
4603 // Including count equalizes the chances any candidate is "selected".
4604 // This is useful when we don't have the complete list of candidates to choose
4605 // from uniformly. In this case, we need to adjust the randomicity of the
4606 // selection, or else we will end up biasing the selection towards the latter
4607 // candidates.
4608 //
4609 // Quick back-envelope calculation shows that for the list of n candidates
4610 // the equal probability for the candidate to persist as "best" can be
4611 // achieved by replacing it with "next" k-th candidate with the probability
4612 // of 1/k. It can be easily shown that by the end of the run, the
4613 // probability for any candidate is converged to 1/n, thus giving the
4614 // uniform distribution among all the candidates.
4615 //
4616 // We don't care about the domain size as long as (RANDOMIZED_DOMAIN / count) is large.
4617 #define RANDOMIZED_DOMAIN_POW 29
4618 #define RANDOMIZED_DOMAIN (1 << RANDOMIZED_DOMAIN_POW)
4619 #define RANDOMIZED_DOMAIN_MASK ((1 << (RANDOMIZED_DOMAIN_POW + 1)) - 1)
4620 bool Compile::randomized_select(int count) {
4621   assert(count > 0, "only positive");
4622   return (os::random() & RANDOMIZED_DOMAIN_MASK) < (RANDOMIZED_DOMAIN / count);
4623 }
4624 
4625 CloneMap&     Compile::clone_map()                 { return _clone_map; }
4626 void          Compile::set_clone_map(Dict* d)      { _clone_map._dict = d; }
4627 
4628 void NodeCloneInfo::dump() const {
4629   tty->print(" {%d:%d} ", idx(), gen());
4630 }
4631 
4632 void CloneMap::clone(Node* old, Node* nnn, int gen) {
4633   uint64_t val = value(old->_idx);
4634   NodeCloneInfo cio(val);
4635   assert(val != 0, "old node should be in the map");
4636   NodeCloneInfo cin(cio.idx(), gen + cio.gen());
4637   insert(nnn->_idx, cin.get());
4638 #ifndef PRODUCT
4639   if (is_debug()) {
4640     tty->print_cr("CloneMap::clone inserted node %d info {%d:%d} into CloneMap", nnn->_idx, cin.idx(), cin.gen());
4641   }
4642 #endif
4643 }
4644 
4645 void CloneMap::verify_insert_and_clone(Node* old, Node* nnn, int gen) {
4646   NodeCloneInfo cio(value(old->_idx));
4647   if (cio.get() == 0) {
4648     cio.set(old->_idx, 0);
4649     insert(old->_idx, cio.get());
4650 #ifndef PRODUCT
4651     if (is_debug()) {
4652       tty->print_cr("CloneMap::verify_insert_and_clone inserted node %d info {%d:%d} into CloneMap", old->_idx, cio.idx(), cio.gen());
4653     }
4654 #endif
4655   }
4656   clone(old, nnn, gen);
4657 }
4658 
4659 int CloneMap::max_gen() const {
4660   int g = 0;
4661   DictI di(_dict);
4662   for(; di.test(); ++di) {
4663     int t = gen(di._key);
4664     if (g < t) {
4665       g = t;
4666 #ifndef PRODUCT
4667       if (is_debug()) {
4668         tty->print_cr("CloneMap::max_gen() update max=%d from %d", g, _2_node_idx_t(di._key));
4669       }
4670 #endif
4671     }
4672   }
4673   return g;
4674 }
4675 
4676 void CloneMap::dump(node_idx_t key) const {
4677   uint64_t val = value(key);
4678   if (val != 0) {
4679     NodeCloneInfo ni(val);
4680     ni.dump();
4681   }
4682 }