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                   _do_cleanup(false),
 652                   _has_reserved_stack_access(target->has_reserved_stack_access()),
 653 #ifndef PRODUCT
 654                   _trace_opto_output(directive->TraceOptoOutputOption),
 655 #endif
 656                   _has_method_handle_invokes(false),
 657                   _clinit_barrier_on_entry(false),
 658                   _comp_arena(mtCompiler),
 659                   _barrier_set_state(BarrierSet::barrier_set()->barrier_set_c2()->create_barrier_state(comp_arena())),
 660                   _env(ci_env),
 661                   _directive(directive),
 662                   _log(ci_env->log()),
 663                   _failure_reason(NULL),
 664                   _congraph(NULL),
 665 #ifndef PRODUCT
 666                   _printer(IdealGraphPrinter::printer()),
 667 #endif
 668                   _dead_node_list(comp_arena()),
 669                   _dead_node_count(0),
 670                   _node_arena(mtCompiler),
 671                   _old_arena(mtCompiler),
 672                   _mach_constant_base_node(NULL),
 673                   _Compile_types(mtCompiler),
 674                   _initial_gvn(NULL),
 675                   _for_igvn(NULL),
 676                   _warm_calls(NULL),
 677                   _late_inlines(comp_arena(), 2, 0, NULL),
 678                   _string_late_inlines(comp_arena(), 2, 0, NULL),
 679                   _boxing_late_inlines(comp_arena(), 2, 0, NULL),
 680                   _late_inlines_pos(0),
 681                   _number_of_mh_late_inlines(0),
 682                   _print_inlining_stream(NULL),
 683                   _print_inlining_list(NULL),
 684                   _print_inlining_idx(0),
 685                   _print_inlining_output(NULL),
 686                   _replay_inline_data(NULL),
 687                   _java_calls(0),
 688                   _inner_loops(0),
 689                   _interpreter_frame_size(0),
 690                   _node_bundling_limit(0),
 691                   _node_bundling_base(NULL),
 692                   _code_buffer("Compile::Fill_buffer"),
 693                   _scratch_const_size(-1),
 694                   _in_scratch_emit_size(false)
 695 #ifndef PRODUCT
 696                   , _in_dump_cnt(0)
 697 #endif
 698 {
 699   C = this;
 700 #ifndef PRODUCT
 701   if (_printer != NULL) {
 702     _printer->set_compile(this);
 703   }
 704 #endif
 705   CompileWrapper cw(this);
 706 
 707   if (CITimeVerbose) {
 708     tty->print(" ");
 709     target->holder()->name()->print();
 710     tty->print(".");
 711     target->print_short_name();
 712     tty->print("  ");
 713   }
 714   TraceTime t1("Total compilation time", &_t_totalCompilation, CITime, CITimeVerbose);
 715   TraceTime t2(NULL, &_t_methodCompilation, CITime, false);
 716 
 717 #ifndef PRODUCT
 718   bool print_opto_assembly = directive->PrintOptoAssemblyOption;
 719   if (!print_opto_assembly) {
 720     bool print_assembly = directive->PrintAssemblyOption;
 721     if (print_assembly && !Disassembler::can_decode()) {
 722       tty->print_cr("PrintAssembly request changed to PrintOptoAssembly");
 723       print_opto_assembly = true;
 724     }
 725   }
 726   set_print_assembly(print_opto_assembly);
 727   set_parsed_irreducible_loop(false);
 728 
 729   if (directive->ReplayInlineOption) {
 730     _replay_inline_data = ciReplay::load_inline_data(method(), entry_bci(), ci_env->comp_level());
 731   }
 732 #endif
 733   set_print_inlining(directive->PrintInliningOption || PrintOptoInlining);
 734   set_print_intrinsics(directive->PrintIntrinsicsOption);
 735   set_has_irreducible_loop(true); // conservative until build_loop_tree() reset it
 736 
 737   if (ProfileTraps RTM_OPT_ONLY( || UseRTMLocking )) {
 738     // Make sure the method being compiled gets its own MDO,
 739     // so we can at least track the decompile_count().
 740     // Need MDO to record RTM code generation state.
 741     method()->ensure_method_data();
 742   }
 743 
 744   Init(::AliasLevel);
 745 
 746 
 747   print_compile_messages();
 748 
 749   _ilt = InlineTree::build_inline_tree_root();
 750 
 751   // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
 752   assert(num_alias_types() >= AliasIdxRaw, "");
 753 
 754 #define MINIMUM_NODE_HASH  1023
 755   // Node list that Iterative GVN will start with
 756   Unique_Node_List for_igvn(comp_arena());
 757   set_for_igvn(&for_igvn);
 758 
 759   // GVN that will be run immediately on new nodes
 760   uint estimated_size = method()->code_size()*4+64;
 761   estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
 762   PhaseGVN gvn(node_arena(), estimated_size);
 763   set_initial_gvn(&gvn);
 764 
 765   print_inlining_init();
 766   { // Scope for timing the parser
 767     TracePhase tp("parse", &timers[_t_parser]);
 768 
 769     // Put top into the hash table ASAP.
 770     initial_gvn()->transform_no_reclaim(top());
 771 
 772     // Set up tf(), start(), and find a CallGenerator.
 773     CallGenerator* cg = NULL;
 774     if (is_osr_compilation()) {
 775       const TypeTuple *domain = StartOSRNode::osr_domain();
 776       const TypeTuple *range = TypeTuple::make_range(method()->signature());
 777       init_tf(TypeFunc::make(domain, range));
 778       StartNode* s = new StartOSRNode(root(), domain);
 779       initial_gvn()->set_type_bottom(s);
 780       init_start(s);
 781       cg = CallGenerator::for_osr(method(), entry_bci());
 782     } else {
 783       // Normal case.
 784       init_tf(TypeFunc::make(method()));
 785       StartNode* s = new StartNode(root(), tf()->domain());
 786       initial_gvn()->set_type_bottom(s);
 787       init_start(s);
 788       if (method()->intrinsic_id() == vmIntrinsics::_Reference_get) {
 789         // With java.lang.ref.reference.get() we must go through the
 790         // intrinsic - even when get() is the root
 791         // method of the compile - so that, if necessary, the value in
 792         // the referent field of the reference object gets recorded by
 793         // the pre-barrier code.
 794         cg = find_intrinsic(method(), false);
 795       }
 796       if (cg == NULL) {
 797         float past_uses = method()->interpreter_invocation_count();
 798         float expected_uses = past_uses;
 799         cg = CallGenerator::for_inline(method(), expected_uses);
 800       }
 801     }
 802     if (failing())  return;
 803     if (cg == NULL) {
 804       record_method_not_compilable("cannot parse method");
 805       return;
 806     }
 807     JVMState* jvms = build_start_state(start(), tf());
 808     if ((jvms = cg->generate(jvms)) == NULL) {
 809       if (!failure_reason_is(C2Compiler::retry_class_loading_during_parsing())) {
 810         record_method_not_compilable("method parse failed");
 811       }
 812       return;
 813     }
 814     GraphKit kit(jvms);
 815 
 816     if (!kit.stopped()) {
 817       // Accept return values, and transfer control we know not where.
 818       // This is done by a special, unique ReturnNode bound to root.
 819       return_values(kit.jvms());
 820     }
 821 
 822     if (kit.has_exceptions()) {
 823       // Any exceptions that escape from this call must be rethrown
 824       // to whatever caller is dynamically above us on the stack.
 825       // This is done by a special, unique RethrowNode bound to root.
 826       rethrow_exceptions(kit.transfer_exceptions_into_jvms());
 827     }
 828 
 829     assert(IncrementalInline || (_late_inlines.length() == 0 && !has_mh_late_inlines()), "incremental inlining is off");
 830 
 831     if (_late_inlines.length() == 0 && !has_mh_late_inlines() && !failing() && has_stringbuilder()) {
 832       inline_string_calls(true);
 833     }
 834 
 835     if (failing())  return;
 836 
 837     print_method(PHASE_BEFORE_REMOVEUSELESS, 3);
 838 
 839     // Remove clutter produced by parsing.
 840     if (!failing()) {
 841       ResourceMark rm;
 842       PhaseRemoveUseless pru(initial_gvn(), &for_igvn);
 843     }
 844   }
 845 
 846   // Note:  Large methods are capped off in do_one_bytecode().
 847   if (failing())  return;
 848 
 849   // After parsing, node notes are no longer automagic.
 850   // They must be propagated by register_new_node_with_optimizer(),
 851   // clone(), or the like.
 852   set_default_node_notes(NULL);
 853 
 854   for (;;) {
 855     int successes = Inline_Warm();
 856     if (failing())  return;
 857     if (successes == 0)  break;
 858   }
 859 
 860   // Drain the list.
 861   Finish_Warm();
 862 #ifndef PRODUCT
 863   if (_printer && _printer->should_print(1)) {
 864     _printer->print_inlining();
 865   }
 866 #endif
 867 
 868   if (failing())  return;
 869   NOT_PRODUCT( verify_graph_edges(); )
 870 
 871   // Now optimize
 872   Optimize();
 873   if (failing())  return;
 874   NOT_PRODUCT( verify_graph_edges(); )
 875 
 876 #ifndef PRODUCT
 877   if (PrintIdeal) {
 878     ttyLocker ttyl;  // keep the following output all in one block
 879     // This output goes directly to the tty, not the compiler log.
 880     // To enable tools to match it up with the compilation activity,
 881     // be sure to tag this tty output with the compile ID.
 882     if (xtty != NULL) {
 883       xtty->head("ideal compile_id='%d'%s", compile_id(),
 884                  is_osr_compilation()    ? " compile_kind='osr'" :
 885                  "");
 886     }
 887     root()->dump(9999);
 888     if (xtty != NULL) {
 889       xtty->tail("ideal");
 890     }
 891   }
 892 #endif
 893 
 894 #ifdef ASSERT
 895   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 896   bs->verify_gc_barriers(this, BarrierSetC2::BeforeCodeGen);
 897 #endif
 898 
 899   // Dump compilation data to replay it.
 900   if (directive->DumpReplayOption) {
 901     env()->dump_replay_data(_compile_id);
 902   }
 903   if (directive->DumpInlineOption && (ilt() != NULL)) {
 904     env()->dump_inline_data(_compile_id);
 905   }
 906 
 907   // Now that we know the size of all the monitors we can add a fixed slot
 908   // for the original deopt pc.
 909 
 910   _orig_pc_slot =  fixed_slots();
 911   int next_slot = _orig_pc_slot + (sizeof(address) / VMRegImpl::stack_slot_size);
 912   set_fixed_slots(next_slot);
 913 
 914   // Compute when to use implicit null checks. Used by matching trap based
 915   // nodes and NullCheck optimization.
 916   set_allowed_deopt_reasons();
 917 
 918   // Now generate code
 919   Code_Gen();
 920   if (failing())  return;
 921 
 922   // Check if we want to skip execution of all compiled code.
 923   {
 924 #ifndef PRODUCT
 925     if (OptoNoExecute) {
 926       record_method_not_compilable("+OptoNoExecute");  // Flag as failed
 927       return;
 928     }
 929 #endif
 930     TracePhase tp("install_code", &timers[_t_registerMethod]);
 931 
 932     if (is_osr_compilation()) {
 933       _code_offsets.set_value(CodeOffsets::Verified_Entry, 0);
 934       _code_offsets.set_value(CodeOffsets::OSR_Entry, _first_block_size);
 935     } else {
 936       _code_offsets.set_value(CodeOffsets::Verified_Entry, _first_block_size);
 937       _code_offsets.set_value(CodeOffsets::OSR_Entry, 0);
 938     }
 939 
 940     env()->register_method(_method, _entry_bci,
 941                            &_code_offsets,
 942                            _orig_pc_slot_offset_in_bytes,
 943                            code_buffer(),
 944                            frame_size_in_words(), _oop_map_set,
 945                            &_handler_table, &_inc_table,
 946                            compiler,
 947                            has_unsafe_access(),
 948                            SharedRuntime::is_wide_vector(max_vector_size()),
 949                            rtm_state()
 950                            );
 951 
 952     if (log() != NULL) // Print code cache state into compiler log
 953       log()->code_cache_state();
 954   }
 955 }
 956 
 957 //------------------------------Compile----------------------------------------
 958 // Compile a runtime stub
 959 Compile::Compile( ciEnv* ci_env,
 960                   TypeFunc_generator generator,
 961                   address stub_function,
 962                   const char *stub_name,
 963                   int is_fancy_jump,
 964                   bool pass_tls,
 965                   bool save_arg_registers,
 966                   bool return_pc,
 967                   DirectiveSet* directive)
 968   : Phase(Compiler),
 969     _compile_id(0),
 970     _save_argument_registers(save_arg_registers),
 971     _subsume_loads(true),
 972     _do_escape_analysis(false),
 973     _eliminate_boxing(false),
 974     _method(NULL),
 975     _entry_bci(InvocationEntryBci),
 976     _stub_function(stub_function),
 977     _stub_name(stub_name),
 978     _stub_entry_point(NULL),
 979     _max_node_limit(MaxNodeLimit),
 980     _orig_pc_slot(0),
 981     _orig_pc_slot_offset_in_bytes(0),
 982     _inlining_progress(false),
 983     _inlining_incrementally(false),
 984     _has_reserved_stack_access(false),
 985 #ifndef PRODUCT
 986     _trace_opto_output(directive->TraceOptoOutputOption),
 987 #endif
 988     _has_method_handle_invokes(false),
 989     _clinit_barrier_on_entry(false),
 990     _comp_arena(mtCompiler),
 991     _env(ci_env),
 992     _directive(directive),
 993     _log(ci_env->log()),
 994     _failure_reason(NULL),
 995     _congraph(NULL),
 996 #ifndef PRODUCT
 997     _printer(NULL),
 998 #endif
 999     _dead_node_list(comp_arena()),
1000     _dead_node_count(0),
1001     _node_arena(mtCompiler),
1002     _old_arena(mtCompiler),
1003     _mach_constant_base_node(NULL),
1004     _Compile_types(mtCompiler),
1005     _initial_gvn(NULL),
1006     _for_igvn(NULL),
1007     _warm_calls(NULL),
1008     _number_of_mh_late_inlines(0),
1009     _print_inlining_stream(NULL),
1010     _print_inlining_list(NULL),
1011     _print_inlining_idx(0),
1012     _print_inlining_output(NULL),
1013     _replay_inline_data(NULL),
1014     _java_calls(0),
1015     _inner_loops(0),
1016     _interpreter_frame_size(0),
1017     _node_bundling_limit(0),
1018     _node_bundling_base(NULL),
1019     _code_buffer("Compile::Fill_buffer"),
1020 #ifndef PRODUCT
1021     _in_dump_cnt(0),
1022 #endif
1023     _allowed_reasons(0) {
1024   C = this;
1025 
1026   TraceTime t1(NULL, &_t_totalCompilation, CITime, false);
1027   TraceTime t2(NULL, &_t_stubCompilation, CITime, false);
1028 
1029 #ifndef PRODUCT
1030   set_print_assembly(PrintFrameConverterAssembly);
1031   set_parsed_irreducible_loop(false);
1032 #endif
1033   set_has_irreducible_loop(false); // no loops
1034 
1035   CompileWrapper cw(this);
1036   Init(/*AliasLevel=*/ 0);
1037   init_tf((*generator)());
1038 
1039   {
1040     // The following is a dummy for the sake of GraphKit::gen_stub
1041     Unique_Node_List for_igvn(comp_arena());
1042     set_for_igvn(&for_igvn);  // not used, but some GraphKit guys push on this
1043     PhaseGVN gvn(Thread::current()->resource_area(),255);
1044     set_initial_gvn(&gvn);    // not significant, but GraphKit guys use it pervasively
1045     gvn.transform_no_reclaim(top());
1046 
1047     GraphKit kit;
1048     kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
1049   }
1050 
1051   NOT_PRODUCT( verify_graph_edges(); )
1052   Code_Gen();
1053   if (failing())  return;
1054 
1055 
1056   // Entry point will be accessed using compile->stub_entry_point();
1057   if (code_buffer() == NULL) {
1058     Matcher::soft_match_failure();
1059   } else {
1060     if (PrintAssembly && (WizardMode || Verbose))
1061       tty->print_cr("### Stub::%s", stub_name);
1062 
1063     if (!failing()) {
1064       assert(_fixed_slots == 0, "no fixed slots used for runtime stubs");
1065 
1066       // Make the NMethod
1067       // For now we mark the frame as never safe for profile stackwalking
1068       RuntimeStub *rs = RuntimeStub::new_runtime_stub(stub_name,
1069                                                       code_buffer(),
1070                                                       CodeOffsets::frame_never_safe,
1071                                                       // _code_offsets.value(CodeOffsets::Frame_Complete),
1072                                                       frame_size_in_words(),
1073                                                       _oop_map_set,
1074                                                       save_arg_registers);
1075       assert(rs != NULL && rs->is_runtime_stub(), "sanity check");
1076 
1077       _stub_entry_point = rs->entry_point();
1078     }
1079   }
1080 }
1081 
1082 //------------------------------Init-------------------------------------------
1083 // Prepare for a single compilation
1084 void Compile::Init(int aliaslevel) {
1085   _unique  = 0;
1086   _regalloc = NULL;
1087 
1088   _tf      = NULL;  // filled in later
1089   _top     = NULL;  // cached later
1090   _matcher = NULL;  // filled in later
1091   _cfg     = NULL;  // filled in later
1092 
1093   set_24_bit_selection_and_mode(Use24BitFP, false);
1094 
1095   _node_note_array = NULL;
1096   _default_node_notes = NULL;
1097   DEBUG_ONLY( _modified_nodes = NULL; ) // Used in Optimize()
1098 
1099   _immutable_memory = NULL; // filled in at first inquiry
1100 
1101   // Globally visible Nodes
1102   // First set TOP to NULL to give safe behavior during creation of RootNode
1103   set_cached_top_node(NULL);
1104   set_root(new RootNode());
1105   // Now that you have a Root to point to, create the real TOP
1106   set_cached_top_node( new ConNode(Type::TOP) );
1107   set_recent_alloc(NULL, NULL);
1108 
1109   // Create Debug Information Recorder to record scopes, oopmaps, etc.
1110   env()->set_oop_recorder(new OopRecorder(env()->arena()));
1111   env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
1112   env()->set_dependencies(new Dependencies(env()));
1113 
1114   _fixed_slots = 0;
1115   set_has_split_ifs(false);
1116   set_has_loops(has_method() && method()->has_loops()); // first approximation
1117   set_has_stringbuilder(false);
1118   set_has_boxed_value(false);
1119   _trap_can_recompile = false;  // no traps emitted yet
1120   _major_progress = true; // start out assuming good things will happen
1121   set_has_unsafe_access(false);
1122   set_max_vector_size(0);
1123   set_clear_upper_avx(false);  //false as default for clear upper bits of ymm registers
1124   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
1125   set_decompile_count(0);
1126 
1127   set_do_freq_based_layout(_directive->BlockLayoutByFrequencyOption);
1128   _loop_opts_cnt = LoopOptsCount;
1129   set_do_inlining(Inline);
1130   set_max_inline_size(MaxInlineSize);
1131   set_freq_inline_size(FreqInlineSize);
1132   set_do_scheduling(OptoScheduling);
1133   set_do_count_invocations(false);
1134   set_do_method_data_update(false);
1135 
1136   set_do_vector_loop(false);
1137 
1138   if (AllowVectorizeOnDemand) {
1139     if (has_method() && (_directive->VectorizeOption || _directive->VectorizeDebugOption)) {
1140       set_do_vector_loop(true);
1141       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());})
1142     } else if (has_method() && method()->name() != 0 &&
1143                method()->intrinsic_id() == vmIntrinsics::_forEachRemaining) {
1144       set_do_vector_loop(true);
1145     }
1146   }
1147   set_use_cmove(UseCMoveUnconditionally /* || do_vector_loop()*/); //TODO: consider do_vector_loop() mandate use_cmove unconditionally
1148   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());})
1149 
1150   set_age_code(has_method() && method()->profile_aging());
1151   set_rtm_state(NoRTM); // No RTM lock eliding by default
1152   _max_node_limit = _directive->MaxNodeLimitOption;
1153 
1154 #if INCLUDE_RTM_OPT
1155   if (UseRTMLocking && has_method() && (method()->method_data_or_null() != NULL)) {
1156     int rtm_state = method()->method_data()->rtm_state();
1157     if (method_has_option("NoRTMLockEliding") || ((rtm_state & NoRTM) != 0)) {
1158       // Don't generate RTM lock eliding code.
1159       set_rtm_state(NoRTM);
1160     } else if (method_has_option("UseRTMLockEliding") || ((rtm_state & UseRTM) != 0) || !UseRTMDeopt) {
1161       // Generate RTM lock eliding code without abort ratio calculation code.
1162       set_rtm_state(UseRTM);
1163     } else if (UseRTMDeopt) {
1164       // Generate RTM lock eliding code and include abort ratio calculation
1165       // code if UseRTMDeopt is on.
1166       set_rtm_state(ProfileRTM);
1167     }
1168   }
1169 #endif
1170   if (UseFastClassInitChecks && has_method() && !is_osr_compilation() && method()->needs_clinit_barrier()) {
1171     set_clinit_barrier_on_entry(true);
1172   }
1173   if (debug_info()->recording_non_safepoints()) {
1174     set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
1175                         (comp_arena(), 8, 0, NULL));
1176     set_default_node_notes(Node_Notes::make(this));
1177   }
1178 
1179   // // -- Initialize types before each compile --
1180   // // Update cached type information
1181   // if( _method && _method->constants() )
1182   //   Type::update_loaded_types(_method, _method->constants());
1183 
1184   // Init alias_type map.
1185   if (!_do_escape_analysis && aliaslevel == 3)
1186     aliaslevel = 2;  // No unique types without escape analysis
1187   _AliasLevel = aliaslevel;
1188   const int grow_ats = 16;
1189   _max_alias_types = grow_ats;
1190   _alias_types   = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
1191   AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType,  grow_ats);
1192   Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
1193   {
1194     for (int i = 0; i < grow_ats; i++)  _alias_types[i] = &ats[i];
1195   }
1196   // Initialize the first few types.
1197   _alias_types[AliasIdxTop]->Init(AliasIdxTop, NULL);
1198   _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
1199   _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
1200   _num_alias_types = AliasIdxRaw+1;
1201   // Zero out the alias type cache.
1202   Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
1203   // A NULL adr_type hits in the cache right away.  Preload the right answer.
1204   probe_alias_cache(NULL)->_index = AliasIdxTop;
1205 
1206   _intrinsics = NULL;
1207   _macro_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1208   _predicate_opaqs = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1209   _expensive_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1210   _range_check_casts = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1211   _opaque4_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1212   register_library_intrinsics();
1213 }
1214 
1215 //---------------------------init_start----------------------------------------
1216 // Install the StartNode on this compile object.
1217 void Compile::init_start(StartNode* s) {
1218   if (failing())
1219     return; // already failing
1220   assert(s == start(), "");
1221 }
1222 
1223 /**
1224  * Return the 'StartNode'. We must not have a pending failure, since the ideal graph
1225  * can be in an inconsistent state, i.e., we can get segmentation faults when traversing
1226  * the ideal graph.
1227  */
1228 StartNode* Compile::start() const {
1229   assert (!failing(), "Must not have pending failure. Reason is: %s", failure_reason());
1230   for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
1231     Node* start = root()->fast_out(i);
1232     if (start->is_Start()) {
1233       return start->as_Start();
1234     }
1235   }
1236   fatal("Did not find Start node!");
1237   return NULL;
1238 }
1239 
1240 //-------------------------------immutable_memory-------------------------------------
1241 // Access immutable memory
1242 Node* Compile::immutable_memory() {
1243   if (_immutable_memory != NULL) {
1244     return _immutable_memory;
1245   }
1246   StartNode* s = start();
1247   for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
1248     Node *p = s->fast_out(i);
1249     if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
1250       _immutable_memory = p;
1251       return _immutable_memory;
1252     }
1253   }
1254   ShouldNotReachHere();
1255   return NULL;
1256 }
1257 
1258 //----------------------set_cached_top_node------------------------------------
1259 // Install the cached top node, and make sure Node::is_top works correctly.
1260 void Compile::set_cached_top_node(Node* tn) {
1261   if (tn != NULL)  verify_top(tn);
1262   Node* old_top = _top;
1263   _top = tn;
1264   // Calling Node::setup_is_top allows the nodes the chance to adjust
1265   // their _out arrays.
1266   if (_top != NULL)     _top->setup_is_top();
1267   if (old_top != NULL)  old_top->setup_is_top();
1268   assert(_top == NULL || top()->is_top(), "");
1269 }
1270 
1271 #ifdef ASSERT
1272 uint Compile::count_live_nodes_by_graph_walk() {
1273   Unique_Node_List useful(comp_arena());
1274   // Get useful node list by walking the graph.
1275   identify_useful_nodes(useful);
1276   return useful.size();
1277 }
1278 
1279 void Compile::print_missing_nodes() {
1280 
1281   // Return if CompileLog is NULL and PrintIdealNodeCount is false.
1282   if ((_log == NULL) && (! PrintIdealNodeCount)) {
1283     return;
1284   }
1285 
1286   // This is an expensive function. It is executed only when the user
1287   // specifies VerifyIdealNodeCount option or otherwise knows the
1288   // additional work that needs to be done to identify reachable nodes
1289   // by walking the flow graph and find the missing ones using
1290   // _dead_node_list.
1291 
1292   Unique_Node_List useful(comp_arena());
1293   // Get useful node list by walking the graph.
1294   identify_useful_nodes(useful);
1295 
1296   uint l_nodes = C->live_nodes();
1297   uint l_nodes_by_walk = useful.size();
1298 
1299   if (l_nodes != l_nodes_by_walk) {
1300     if (_log != NULL) {
1301       _log->begin_head("mismatched_nodes count='%d'", abs((int) (l_nodes - l_nodes_by_walk)));
1302       _log->stamp();
1303       _log->end_head();
1304     }
1305     VectorSet& useful_member_set = useful.member_set();
1306     int last_idx = l_nodes_by_walk;
1307     for (int i = 0; i < last_idx; i++) {
1308       if (useful_member_set.test(i)) {
1309         if (_dead_node_list.test(i)) {
1310           if (_log != NULL) {
1311             _log->elem("mismatched_node_info node_idx='%d' type='both live and dead'", i);
1312           }
1313           if (PrintIdealNodeCount) {
1314             // Print the log message to tty
1315               tty->print_cr("mismatched_node idx='%d' both live and dead'", i);
1316               useful.at(i)->dump();
1317           }
1318         }
1319       }
1320       else if (! _dead_node_list.test(i)) {
1321         if (_log != NULL) {
1322           _log->elem("mismatched_node_info node_idx='%d' type='neither live nor dead'", i);
1323         }
1324         if (PrintIdealNodeCount) {
1325           // Print the log message to tty
1326           tty->print_cr("mismatched_node idx='%d' type='neither live nor dead'", i);
1327         }
1328       }
1329     }
1330     if (_log != NULL) {
1331       _log->tail("mismatched_nodes");
1332     }
1333   }
1334 }
1335 void Compile::record_modified_node(Node* n) {
1336   if (_modified_nodes != NULL && !_inlining_incrementally &&
1337       n->outcnt() != 0 && !n->is_Con()) {
1338     _modified_nodes->push(n);
1339   }
1340 }
1341 
1342 void Compile::remove_modified_node(Node* n) {
1343   if (_modified_nodes != NULL) {
1344     _modified_nodes->remove(n);
1345   }
1346 }
1347 #endif
1348 
1349 #ifndef PRODUCT
1350 void Compile::verify_top(Node* tn) const {
1351   if (tn != NULL) {
1352     assert(tn->is_Con(), "top node must be a constant");
1353     assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
1354     assert(tn->in(0) != NULL, "must have live top node");
1355   }
1356 }
1357 #endif
1358 
1359 
1360 ///-------------------Managing Per-Node Debug & Profile Info-------------------
1361 
1362 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
1363   guarantee(arr != NULL, "");
1364   int num_blocks = arr->length();
1365   if (grow_by < num_blocks)  grow_by = num_blocks;
1366   int num_notes = grow_by * _node_notes_block_size;
1367   Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
1368   Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
1369   while (num_notes > 0) {
1370     arr->append(notes);
1371     notes     += _node_notes_block_size;
1372     num_notes -= _node_notes_block_size;
1373   }
1374   assert(num_notes == 0, "exact multiple, please");
1375 }
1376 
1377 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
1378   if (source == NULL || dest == NULL)  return false;
1379 
1380   if (dest->is_Con())
1381     return false;               // Do not push debug info onto constants.
1382 
1383 #ifdef ASSERT
1384   // Leave a bread crumb trail pointing to the original node:
1385   if (dest != NULL && dest != source && dest->debug_orig() == NULL) {
1386     dest->set_debug_orig(source);
1387   }
1388 #endif
1389 
1390   if (node_note_array() == NULL)
1391     return false;               // Not collecting any notes now.
1392 
1393   // This is a copy onto a pre-existing node, which may already have notes.
1394   // If both nodes have notes, do not overwrite any pre-existing notes.
1395   Node_Notes* source_notes = node_notes_at(source->_idx);
1396   if (source_notes == NULL || source_notes->is_clear())  return false;
1397   Node_Notes* dest_notes   = node_notes_at(dest->_idx);
1398   if (dest_notes == NULL || dest_notes->is_clear()) {
1399     return set_node_notes_at(dest->_idx, source_notes);
1400   }
1401 
1402   Node_Notes merged_notes = (*source_notes);
1403   // The order of operations here ensures that dest notes will win...
1404   merged_notes.update_from(dest_notes);
1405   return set_node_notes_at(dest->_idx, &merged_notes);
1406 }
1407 
1408 
1409 //--------------------------allow_range_check_smearing-------------------------
1410 // Gating condition for coalescing similar range checks.
1411 // Sometimes we try 'speculatively' replacing a series of a range checks by a
1412 // single covering check that is at least as strong as any of them.
1413 // If the optimization succeeds, the simplified (strengthened) range check
1414 // will always succeed.  If it fails, we will deopt, and then give up
1415 // on the optimization.
1416 bool Compile::allow_range_check_smearing() const {
1417   // If this method has already thrown a range-check,
1418   // assume it was because we already tried range smearing
1419   // and it failed.
1420   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
1421   return !already_trapped;
1422 }
1423 
1424 
1425 //------------------------------flatten_alias_type-----------------------------
1426 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
1427   int offset = tj->offset();
1428   TypePtr::PTR ptr = tj->ptr();
1429 
1430   // Known instance (scalarizable allocation) alias only with itself.
1431   bool is_known_inst = tj->isa_oopptr() != NULL &&
1432                        tj->is_oopptr()->is_known_instance();
1433 
1434   // Process weird unsafe references.
1435   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
1436     assert(InlineUnsafeOps, "indeterminate pointers come only from unsafe ops");
1437     assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
1438     tj = TypeOopPtr::BOTTOM;
1439     ptr = tj->ptr();
1440     offset = tj->offset();
1441   }
1442 
1443   // Array pointers need some flattening
1444   const TypeAryPtr *ta = tj->isa_aryptr();
1445   if (ta && ta->is_stable()) {
1446     // Erase stability property for alias analysis.
1447     tj = ta = ta->cast_to_stable(false);
1448   }
1449   if( ta && is_known_inst ) {
1450     if ( offset != Type::OffsetBot &&
1451          offset > arrayOopDesc::length_offset_in_bytes() ) {
1452       offset = Type::OffsetBot; // Flatten constant access into array body only
1453       tj = ta = TypeAryPtr::make(ptr, ta->ary(), ta->klass(), true, offset, ta->instance_id());
1454     }
1455   } else if( ta && _AliasLevel >= 2 ) {
1456     // For arrays indexed by constant indices, we flatten the alias
1457     // space to include all of the array body.  Only the header, klass
1458     // and array length can be accessed un-aliased.
1459     if( offset != Type::OffsetBot ) {
1460       if( ta->const_oop() ) { // MethodData* or Method*
1461         offset = Type::OffsetBot;   // Flatten constant access into array body
1462         tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),ta->ary(),ta->klass(),false,offset);
1463       } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
1464         // range is OK as-is.
1465         tj = ta = TypeAryPtr::RANGE;
1466       } else if( offset == oopDesc::klass_offset_in_bytes() ) {
1467         tj = TypeInstPtr::KLASS; // all klass loads look alike
1468         ta = TypeAryPtr::RANGE; // generic ignored junk
1469         ptr = TypePtr::BotPTR;
1470       } else if( offset == oopDesc::mark_offset_in_bytes() ) {
1471         tj = TypeInstPtr::MARK;
1472         ta = TypeAryPtr::RANGE; // generic ignored junk
1473         ptr = TypePtr::BotPTR;
1474       } else if (BarrierSet::barrier_set()->barrier_set_c2()->flatten_gc_alias_type(tj)) {
1475         ta = tj->isa_aryptr();
1476       } else {                  // Random constant offset into array body
1477         offset = Type::OffsetBot;   // Flatten constant access into array body
1478         tj = ta = TypeAryPtr::make(ptr,ta->ary(),ta->klass(),false,offset);
1479       }
1480     }
1481     // Arrays of fixed size alias with arrays of unknown size.
1482     if (ta->size() != TypeInt::POS) {
1483       const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
1484       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,ta->klass(),false,offset);
1485     }
1486     // Arrays of known objects become arrays of unknown objects.
1487     if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
1488       const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
1489       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1490     }
1491     if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
1492       const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
1493       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1494     }
1495     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
1496     // cannot be distinguished by bytecode alone.
1497     if (ta->elem() == TypeInt::BOOL) {
1498       const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
1499       ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
1500       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,offset);
1501     }
1502     // During the 2nd round of IterGVN, NotNull castings are removed.
1503     // Make sure the Bottom and NotNull variants alias the same.
1504     // Also, make sure exact and non-exact variants alias the same.
1505     if (ptr == TypePtr::NotNull || ta->klass_is_exact() || ta->speculative() != NULL) {
1506       tj = ta = TypeAryPtr::make(TypePtr::BotPTR,ta->ary(),ta->klass(),false,offset);
1507     }
1508   }
1509 
1510   // Oop pointers need some flattening
1511   const TypeInstPtr *to = tj->isa_instptr();
1512   if( to && _AliasLevel >= 2 && to != TypeOopPtr::BOTTOM ) {
1513     ciInstanceKlass *k = to->klass()->as_instance_klass();
1514     if( ptr == TypePtr::Constant ) {
1515       if (to->klass() != ciEnv::current()->Class_klass() ||
1516           offset < k->size_helper() * wordSize) {
1517         // No constant oop pointers (such as Strings); they alias with
1518         // unknown strings.
1519         assert(!is_known_inst, "not scalarizable allocation");
1520         tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1521       }
1522     } else if( is_known_inst ) {
1523       tj = to; // Keep NotNull and klass_is_exact for instance type
1524     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
1525       // During the 2nd round of IterGVN, NotNull castings are removed.
1526       // Make sure the Bottom and NotNull variants alias the same.
1527       // Also, make sure exact and non-exact variants alias the same.
1528       tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1529     }
1530     if (to->speculative() != NULL) {
1531       tj = to = TypeInstPtr::make(to->ptr(),to->klass(),to->klass_is_exact(),to->const_oop(),to->offset(), to->instance_id());
1532     }
1533     // Canonicalize the holder of this field
1534     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
1535       // First handle header references such as a LoadKlassNode, even if the
1536       // object's klass is unloaded at compile time (4965979).
1537       if (!is_known_inst) { // Do it only for non-instance types
1538         tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, NULL, offset);
1539       }
1540     } else if (BarrierSet::barrier_set()->barrier_set_c2()->flatten_gc_alias_type(tj)) {
1541       to = tj->is_instptr();
1542     } else if (offset < 0 || offset >= k->size_helper() * wordSize) {
1543       // Static fields are in the space above the normal instance
1544       // fields in the java.lang.Class instance.
1545       if (to->klass() != ciEnv::current()->Class_klass()) {
1546         to = NULL;
1547         tj = TypeOopPtr::BOTTOM;
1548         offset = tj->offset();
1549       }
1550     } else {
1551       ciInstanceKlass *canonical_holder = k->get_canonical_holder(offset);
1552       if (!k->equals(canonical_holder) || tj->offset() != offset) {
1553         if( is_known_inst ) {
1554           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, true, NULL, offset, to->instance_id());
1555         } else {
1556           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, false, NULL, offset);
1557         }
1558       }
1559     }
1560   }
1561 
1562   // Klass pointers to object array klasses need some flattening
1563   const TypeKlassPtr *tk = tj->isa_klassptr();
1564   if( tk ) {
1565     // If we are referencing a field within a Klass, we need
1566     // to assume the worst case of an Object.  Both exact and
1567     // inexact types must flatten to the same alias class so
1568     // use NotNull as the PTR.
1569     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
1570 
1571       tj = tk = TypeKlassPtr::make(TypePtr::NotNull,
1572                                    TypeKlassPtr::OBJECT->klass(),
1573                                    offset);
1574     }
1575 
1576     ciKlass* klass = tk->klass();
1577     if( klass->is_obj_array_klass() ) {
1578       ciKlass* k = TypeAryPtr::OOPS->klass();
1579       if( !k || !k->is_loaded() )                  // Only fails for some -Xcomp runs
1580         k = TypeInstPtr::BOTTOM->klass();
1581       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, k, offset );
1582     }
1583 
1584     // Check for precise loads from the primary supertype array and force them
1585     // to the supertype cache alias index.  Check for generic array loads from
1586     // the primary supertype array and also force them to the supertype cache
1587     // alias index.  Since the same load can reach both, we need to merge
1588     // these 2 disparate memories into the same alias class.  Since the
1589     // primary supertype array is read-only, there's no chance of confusion
1590     // where we bypass an array load and an array store.
1591     int primary_supers_offset = in_bytes(Klass::primary_supers_offset());
1592     if (offset == Type::OffsetBot ||
1593         (offset >= primary_supers_offset &&
1594          offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
1595         offset == (int)in_bytes(Klass::secondary_super_cache_offset())) {
1596       offset = in_bytes(Klass::secondary_super_cache_offset());
1597       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, tk->klass(), offset );
1598     }
1599   }
1600 
1601   // Flatten all Raw pointers together.
1602   if (tj->base() == Type::RawPtr)
1603     tj = TypeRawPtr::BOTTOM;
1604 
1605   if (tj->base() == Type::AnyPtr)
1606     tj = TypePtr::BOTTOM;      // An error, which the caller must check for.
1607 
1608   // Flatten all to bottom for now
1609   switch( _AliasLevel ) {
1610   case 0:
1611     tj = TypePtr::BOTTOM;
1612     break;
1613   case 1:                       // Flatten to: oop, static, field or array
1614     switch (tj->base()) {
1615     //case Type::AryPtr: tj = TypeAryPtr::RANGE;    break;
1616     case Type::RawPtr:   tj = TypeRawPtr::BOTTOM;   break;
1617     case Type::AryPtr:   // do not distinguish arrays at all
1618     case Type::InstPtr:  tj = TypeInstPtr::BOTTOM;  break;
1619     case Type::KlassPtr: tj = TypeKlassPtr::OBJECT; break;
1620     case Type::AnyPtr:   tj = TypePtr::BOTTOM;      break;  // caller checks it
1621     default: ShouldNotReachHere();
1622     }
1623     break;
1624   case 2:                       // No collapsing at level 2; keep all splits
1625   case 3:                       // No collapsing at level 3; keep all splits
1626     break;
1627   default:
1628     Unimplemented();
1629   }
1630 
1631   offset = tj->offset();
1632   assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
1633 
1634   assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
1635           (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
1636           (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
1637           (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
1638           (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1639           (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1640           (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1641           (BarrierSet::barrier_set()->barrier_set_c2()->verify_gc_alias_type(tj, offset)),
1642           "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
1643   assert( tj->ptr() != TypePtr::TopPTR &&
1644           tj->ptr() != TypePtr::AnyNull &&
1645           tj->ptr() != TypePtr::Null, "No imprecise addresses" );
1646 //    assert( tj->ptr() != TypePtr::Constant ||
1647 //            tj->base() == Type::RawPtr ||
1648 //            tj->base() == Type::KlassPtr, "No constant oop addresses" );
1649 
1650   return tj;
1651 }
1652 
1653 void Compile::AliasType::Init(int i, const TypePtr* at) {
1654   _index = i;
1655   _adr_type = at;
1656   _field = NULL;
1657   _element = NULL;
1658   _is_rewritable = true; // default
1659   const TypeOopPtr *atoop = (at != NULL) ? at->isa_oopptr() : NULL;
1660   if (atoop != NULL && atoop->is_known_instance()) {
1661     const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
1662     _general_index = Compile::current()->get_alias_index(gt);
1663   } else {
1664     _general_index = 0;
1665   }
1666 }
1667 
1668 BasicType Compile::AliasType::basic_type() const {
1669   if (element() != NULL) {
1670     const Type* element = adr_type()->is_aryptr()->elem();
1671     return element->isa_narrowoop() ? T_OBJECT : element->array_element_basic_type();
1672   } if (field() != NULL) {
1673     return field()->layout_type();
1674   } else {
1675     return T_ILLEGAL; // unknown
1676   }
1677 }
1678 
1679 //---------------------------------print_on------------------------------------
1680 #ifndef PRODUCT
1681 void Compile::AliasType::print_on(outputStream* st) {
1682   if (index() < 10)
1683         st->print("@ <%d> ", index());
1684   else  st->print("@ <%d>",  index());
1685   st->print(is_rewritable() ? "   " : " RO");
1686   int offset = adr_type()->offset();
1687   if (offset == Type::OffsetBot)
1688         st->print(" +any");
1689   else  st->print(" +%-3d", offset);
1690   st->print(" in ");
1691   adr_type()->dump_on(st);
1692   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
1693   if (field() != NULL && tjp) {
1694     if (tjp->klass()  != field()->holder() ||
1695         tjp->offset() != field()->offset_in_bytes()) {
1696       st->print(" != ");
1697       field()->print();
1698       st->print(" ***");
1699     }
1700   }
1701 }
1702 
1703 void print_alias_types() {
1704   Compile* C = Compile::current();
1705   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
1706   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
1707     C->alias_type(idx)->print_on(tty);
1708     tty->cr();
1709   }
1710 }
1711 #endif
1712 
1713 
1714 //----------------------------probe_alias_cache--------------------------------
1715 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
1716   intptr_t key = (intptr_t) adr_type;
1717   key ^= key >> logAliasCacheSize;
1718   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
1719 }
1720 
1721 
1722 //-----------------------------grow_alias_types--------------------------------
1723 void Compile::grow_alias_types() {
1724   const int old_ats  = _max_alias_types; // how many before?
1725   const int new_ats  = old_ats;          // how many more?
1726   const int grow_ats = old_ats+new_ats;  // how many now?
1727   _max_alias_types = grow_ats;
1728   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
1729   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
1730   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
1731   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
1732 }
1733 
1734 
1735 //--------------------------------find_alias_type------------------------------
1736 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field) {
1737   if (_AliasLevel == 0)
1738     return alias_type(AliasIdxBot);
1739 
1740   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1741   if (ace->_adr_type == adr_type) {
1742     return alias_type(ace->_index);
1743   }
1744 
1745   // Handle special cases.
1746   if (adr_type == NULL)             return alias_type(AliasIdxTop);
1747   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
1748 
1749   // Do it the slow way.
1750   const TypePtr* flat = flatten_alias_type(adr_type);
1751 
1752 #ifdef ASSERT
1753   {
1754     ResourceMark rm;
1755     assert(flat == flatten_alias_type(flat), "not idempotent: adr_type = %s; flat = %s => %s",
1756            Type::str(adr_type), Type::str(flat), Type::str(flatten_alias_type(flat)));
1757     assert(flat != TypePtr::BOTTOM, "cannot alias-analyze an untyped ptr: adr_type = %s",
1758            Type::str(adr_type));
1759     if (flat->isa_oopptr() && !flat->isa_klassptr()) {
1760       const TypeOopPtr* foop = flat->is_oopptr();
1761       // Scalarizable allocations have exact klass always.
1762       bool exact = !foop->klass_is_exact() || foop->is_known_instance();
1763       const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
1764       assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type: foop = %s; xoop = %s",
1765              Type::str(foop), Type::str(xoop));
1766     }
1767   }
1768 #endif
1769 
1770   int idx = AliasIdxTop;
1771   for (int i = 0; i < num_alias_types(); i++) {
1772     if (alias_type(i)->adr_type() == flat) {
1773       idx = i;
1774       break;
1775     }
1776   }
1777 
1778   if (idx == AliasIdxTop) {
1779     if (no_create)  return NULL;
1780     // Grow the array if necessary.
1781     if (_num_alias_types == _max_alias_types)  grow_alias_types();
1782     // Add a new alias type.
1783     idx = _num_alias_types++;
1784     _alias_types[idx]->Init(idx, flat);
1785     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
1786     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
1787     if (flat->isa_instptr()) {
1788       if (flat->offset() == java_lang_Class::klass_offset_in_bytes()
1789           && flat->is_instptr()->klass() == env()->Class_klass())
1790         alias_type(idx)->set_rewritable(false);
1791     }
1792     if (flat->isa_aryptr()) {
1793 #ifdef ASSERT
1794       const int header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1795       // (T_BYTE has the weakest alignment and size restrictions...)
1796       assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
1797 #endif
1798       if (flat->offset() == TypePtr::OffsetBot) {
1799         alias_type(idx)->set_element(flat->is_aryptr()->elem());
1800       }
1801     }
1802     if (flat->isa_klassptr()) {
1803       if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
1804         alias_type(idx)->set_rewritable(false);
1805       if (flat->offset() == in_bytes(Klass::modifier_flags_offset()))
1806         alias_type(idx)->set_rewritable(false);
1807       if (flat->offset() == in_bytes(Klass::access_flags_offset()))
1808         alias_type(idx)->set_rewritable(false);
1809       if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
1810         alias_type(idx)->set_rewritable(false);
1811     }
1812     // %%% (We would like to finalize JavaThread::threadObj_offset(),
1813     // but the base pointer type is not distinctive enough to identify
1814     // references into JavaThread.)
1815 
1816     // Check for final fields.
1817     const TypeInstPtr* tinst = flat->isa_instptr();
1818     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
1819       ciField* field;
1820       if (tinst->const_oop() != NULL &&
1821           tinst->klass() == ciEnv::current()->Class_klass() &&
1822           tinst->offset() >= (tinst->klass()->as_instance_klass()->size_helper() * wordSize)) {
1823         // static field
1824         ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
1825         field = k->get_field_by_offset(tinst->offset(), true);
1826       } else {
1827         ciInstanceKlass *k = tinst->klass()->as_instance_klass();
1828         field = k->get_field_by_offset(tinst->offset(), false);
1829       }
1830       assert(field == NULL ||
1831              original_field == NULL ||
1832              (field->holder() == original_field->holder() &&
1833               field->offset() == original_field->offset() &&
1834               field->is_static() == original_field->is_static()), "wrong field?");
1835       // Set field() and is_rewritable() attributes.
1836       if (field != NULL)  alias_type(idx)->set_field(field);
1837     }
1838   }
1839 
1840   // Fill the cache for next time.
1841   ace->_adr_type = adr_type;
1842   ace->_index    = idx;
1843   assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
1844 
1845   // Might as well try to fill the cache for the flattened version, too.
1846   AliasCacheEntry* face = probe_alias_cache(flat);
1847   if (face->_adr_type == NULL) {
1848     face->_adr_type = flat;
1849     face->_index    = idx;
1850     assert(alias_type(flat) == alias_type(idx), "flat type must work too");
1851   }
1852 
1853   return alias_type(idx);
1854 }
1855 
1856 
1857 Compile::AliasType* Compile::alias_type(ciField* field) {
1858   const TypeOopPtr* t;
1859   if (field->is_static())
1860     t = TypeInstPtr::make(field->holder()->java_mirror());
1861   else
1862     t = TypeOopPtr::make_from_klass_raw(field->holder());
1863   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);
1864   assert((field->is_final() || field->is_stable()) == !atp->is_rewritable(), "must get the rewritable bits correct");
1865   return atp;
1866 }
1867 
1868 
1869 //------------------------------have_alias_type--------------------------------
1870 bool Compile::have_alias_type(const TypePtr* adr_type) {
1871   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1872   if (ace->_adr_type == adr_type) {
1873     return true;
1874   }
1875 
1876   // Handle special cases.
1877   if (adr_type == NULL)             return true;
1878   if (adr_type == TypePtr::BOTTOM)  return true;
1879 
1880   return find_alias_type(adr_type, true, NULL) != NULL;
1881 }
1882 
1883 //-----------------------------must_alias--------------------------------------
1884 // True if all values of the given address type are in the given alias category.
1885 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
1886   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1887   if (adr_type == NULL)                 return true;  // NULL serves as TypePtr::TOP
1888   if (alias_idx == AliasIdxTop)         return false; // the empty category
1889   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
1890 
1891   // the only remaining possible overlap is identity
1892   int adr_idx = get_alias_index(adr_type);
1893   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1894   assert(adr_idx == alias_idx ||
1895          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
1896           && adr_type                       != TypeOopPtr::BOTTOM),
1897          "should not be testing for overlap with an unsafe pointer");
1898   return adr_idx == alias_idx;
1899 }
1900 
1901 //------------------------------can_alias--------------------------------------
1902 // True if any values of the given address type are in the given alias category.
1903 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
1904   if (alias_idx == AliasIdxTop)         return false; // the empty category
1905   if (adr_type == NULL)                 return false; // NULL serves as TypePtr::TOP
1906   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1907   if (adr_type->base() == Type::AnyPtr) return true;  // TypePtr::BOTTOM or its twins
1908 
1909   // the only remaining possible overlap is identity
1910   int adr_idx = get_alias_index(adr_type);
1911   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1912   return adr_idx == alias_idx;
1913 }
1914 
1915 
1916 
1917 //---------------------------pop_warm_call-------------------------------------
1918 WarmCallInfo* Compile::pop_warm_call() {
1919   WarmCallInfo* wci = _warm_calls;
1920   if (wci != NULL)  _warm_calls = wci->remove_from(wci);
1921   return wci;
1922 }
1923 
1924 //----------------------------Inline_Warm--------------------------------------
1925 int Compile::Inline_Warm() {
1926   // If there is room, try to inline some more warm call sites.
1927   // %%% Do a graph index compaction pass when we think we're out of space?
1928   if (!InlineWarmCalls)  return 0;
1929 
1930   int calls_made_hot = 0;
1931   int room_to_grow   = NodeCountInliningCutoff - unique();
1932   int amount_to_grow = MIN2(room_to_grow, (int)NodeCountInliningStep);
1933   int amount_grown   = 0;
1934   WarmCallInfo* call;
1935   while (amount_to_grow > 0 && (call = pop_warm_call()) != NULL) {
1936     int est_size = (int)call->size();
1937     if (est_size > (room_to_grow - amount_grown)) {
1938       // This one won't fit anyway.  Get rid of it.
1939       call->make_cold();
1940       continue;
1941     }
1942     call->make_hot();
1943     calls_made_hot++;
1944     amount_grown   += est_size;
1945     amount_to_grow -= est_size;
1946   }
1947 
1948   if (calls_made_hot > 0)  set_major_progress();
1949   return calls_made_hot;
1950 }
1951 
1952 
1953 //----------------------------Finish_Warm--------------------------------------
1954 void Compile::Finish_Warm() {
1955   if (!InlineWarmCalls)  return;
1956   if (failing())  return;
1957   if (warm_calls() == NULL)  return;
1958 
1959   // Clean up loose ends, if we are out of space for inlining.
1960   WarmCallInfo* call;
1961   while ((call = pop_warm_call()) != NULL) {
1962     call->make_cold();
1963   }
1964 }
1965 
1966 //---------------------cleanup_loop_predicates-----------------------
1967 // Remove the opaque nodes that protect the predicates so that all unused
1968 // checks and uncommon_traps will be eliminated from the ideal graph
1969 void Compile::cleanup_loop_predicates(PhaseIterGVN &igvn) {
1970   if (predicate_count()==0) return;
1971   for (int i = predicate_count(); i > 0; i--) {
1972     Node * n = predicate_opaque1_node(i-1);
1973     assert(n->Opcode() == Op_Opaque1, "must be");
1974     igvn.replace_node(n, n->in(1));
1975   }
1976   assert(predicate_count()==0, "should be clean!");
1977 }
1978 
1979 void Compile::add_range_check_cast(Node* n) {
1980   assert(n->isa_CastII()->has_range_check(), "CastII should have range check dependency");
1981   assert(!_range_check_casts->contains(n), "duplicate entry in range check casts");
1982   _range_check_casts->append(n);
1983 }
1984 
1985 // Remove all range check dependent CastIINodes.
1986 void Compile::remove_range_check_casts(PhaseIterGVN &igvn) {
1987   for (int i = range_check_cast_count(); i > 0; i--) {
1988     Node* cast = range_check_cast_node(i-1);
1989     assert(cast->isa_CastII()->has_range_check(), "CastII should have range check dependency");
1990     igvn.replace_node(cast, cast->in(1));
1991   }
1992   assert(range_check_cast_count() == 0, "should be empty");
1993 }
1994 
1995 void Compile::add_opaque4_node(Node* n) {
1996   assert(n->Opcode() == Op_Opaque4, "Opaque4 only");
1997   assert(!_opaque4_nodes->contains(n), "duplicate entry in Opaque4 list");
1998   _opaque4_nodes->append(n);
1999 }
2000 
2001 // Remove all Opaque4 nodes.
2002 void Compile::remove_opaque4_nodes(PhaseIterGVN &igvn) {
2003   for (int i = opaque4_count(); i > 0; i--) {
2004     Node* opaq = opaque4_node(i-1);
2005     assert(opaq->Opcode() == Op_Opaque4, "Opaque4 only");
2006     igvn.replace_node(opaq, opaq->in(2));
2007   }
2008   assert(opaque4_count() == 0, "should be empty");
2009 }
2010 
2011 // StringOpts and late inlining of string methods
2012 void Compile::inline_string_calls(bool parse_time) {
2013   {
2014     // remove useless nodes to make the usage analysis simpler
2015     ResourceMark rm;
2016     PhaseRemoveUseless pru(initial_gvn(), for_igvn());
2017   }
2018 
2019   {
2020     ResourceMark rm;
2021     print_method(PHASE_BEFORE_STRINGOPTS, 3);
2022     PhaseStringOpts pso(initial_gvn(), for_igvn());
2023     print_method(PHASE_AFTER_STRINGOPTS, 3);
2024   }
2025 
2026   // now inline anything that we skipped the first time around
2027   if (!parse_time) {
2028     _late_inlines_pos = _late_inlines.length();
2029   }
2030 
2031   while (_string_late_inlines.length() > 0) {
2032     CallGenerator* cg = _string_late_inlines.pop();
2033     cg->do_late_inline();
2034     if (failing())  return;
2035   }
2036   _string_late_inlines.trunc_to(0);
2037 }
2038 
2039 // Late inlining of boxing methods
2040 void Compile::inline_boxing_calls(PhaseIterGVN& igvn) {
2041   if (_boxing_late_inlines.length() > 0) {
2042     assert(has_boxed_value(), "inconsistent");
2043 
2044     PhaseGVN* gvn = initial_gvn();
2045     set_inlining_incrementally(true);
2046 
2047     assert( igvn._worklist.size() == 0, "should be done with igvn" );
2048     for_igvn()->clear();
2049     gvn->replace_with(&igvn);
2050 
2051     _late_inlines_pos = _late_inlines.length();
2052 
2053     while (_boxing_late_inlines.length() > 0) {
2054       CallGenerator* cg = _boxing_late_inlines.pop();
2055       cg->do_late_inline();
2056       if (failing())  return;
2057     }
2058     _boxing_late_inlines.trunc_to(0);
2059 
2060     inline_incrementally_cleanup(igvn);
2061 
2062     set_inlining_incrementally(false);
2063   }
2064 }
2065 
2066 bool Compile::inline_incrementally_one() {
2067   assert(IncrementalInline, "incremental inlining should be on");
2068 
2069   TracePhase tp("incrementalInline_inline", &timers[_t_incrInline_inline]);
2070   set_inlining_progress(false);
2071   set_do_cleanup(false);
2072   int i = 0;
2073   for (; i <_late_inlines.length() && !inlining_progress(); i++) {
2074     CallGenerator* cg = _late_inlines.at(i);
2075     _late_inlines_pos = i+1;
2076     cg->do_late_inline();
2077     if (failing())  return false;
2078   }
2079   int j = 0;
2080   for (; i < _late_inlines.length(); i++, j++) {
2081     _late_inlines.at_put(j, _late_inlines.at(i));
2082   }
2083   _late_inlines.trunc_to(j);
2084   assert(inlining_progress() || _late_inlines.length() == 0, "");
2085 
2086   bool needs_cleanup = do_cleanup() || over_inlining_cutoff();
2087 
2088   set_inlining_progress(false);
2089   set_do_cleanup(false);
2090   return (_late_inlines.length() > 0) && !needs_cleanup;
2091 }
2092 
2093 void Compile::inline_incrementally_cleanup(PhaseIterGVN& igvn) {
2094   {
2095     TracePhase tp("incrementalInline_pru", &timers[_t_incrInline_pru]);
2096     ResourceMark rm;
2097     PhaseRemoveUseless pru(initial_gvn(), for_igvn());
2098   }
2099   {
2100     TracePhase tp("incrementalInline_igvn", &timers[_t_incrInline_igvn]);
2101     igvn = PhaseIterGVN(initial_gvn());
2102     igvn.optimize();
2103   }
2104 }
2105 
2106 // Perform incremental inlining until bound on number of live nodes is reached
2107 void Compile::inline_incrementally(PhaseIterGVN& igvn) {
2108   TracePhase tp("incrementalInline", &timers[_t_incrInline]);
2109 
2110   set_inlining_incrementally(true);
2111   uint low_live_nodes = 0;
2112 
2113   while (_late_inlines.length() > 0) {
2114     if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2115       if (low_live_nodes < (uint)LiveNodeCountInliningCutoff * 8 / 10) {
2116         TracePhase tp("incrementalInline_ideal", &timers[_t_incrInline_ideal]);
2117         // PhaseIdealLoop is expensive so we only try it once we are
2118         // out of live nodes and we only try it again if the previous
2119         // helped got the number of nodes down significantly
2120         PhaseIdealLoop::optimize(igvn, LoopOptsNone);
2121         if (failing())  return;
2122         low_live_nodes = live_nodes();
2123         _major_progress = true;
2124       }
2125 
2126       if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2127         break; // finish
2128       }
2129     }
2130 
2131     for_igvn()->clear();
2132     initial_gvn()->replace_with(&igvn);
2133 
2134     while (inline_incrementally_one()) {
2135       assert(!failing(), "inconsistent");
2136     }
2137 
2138     if (failing())  return;
2139 
2140     inline_incrementally_cleanup(igvn);
2141 
2142     if (failing())  return;
2143   }
2144   assert( igvn._worklist.size() == 0, "should be done with igvn" );
2145 
2146   if (_string_late_inlines.length() > 0) {
2147     assert(has_stringbuilder(), "inconsistent");
2148     for_igvn()->clear();
2149     initial_gvn()->replace_with(&igvn);
2150 
2151     inline_string_calls(false);
2152 
2153     if (failing())  return;
2154 
2155     inline_incrementally_cleanup(igvn);
2156   }
2157 
2158   set_inlining_incrementally(false);
2159 }
2160 
2161 
2162 bool Compile::optimize_loops(PhaseIterGVN& igvn, LoopOptsMode mode) {
2163   if(_loop_opts_cnt > 0) {
2164     debug_only( int cnt = 0; );
2165     while(major_progress() && (_loop_opts_cnt > 0)) {
2166       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2167       assert( cnt++ < 40, "infinite cycle in loop optimization" );
2168       PhaseIdealLoop::optimize(igvn, mode);
2169       _loop_opts_cnt--;
2170       if (failing())  return false;
2171       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
2172     }
2173   }
2174   return true;
2175 }
2176 
2177 // Remove edges from "root" to each SafePoint at a backward branch.
2178 // They were inserted during parsing (see add_safepoint()) to make
2179 // infinite loops without calls or exceptions visible to root, i.e.,
2180 // useful.
2181 void Compile::remove_root_to_sfpts_edges(PhaseIterGVN& igvn) {
2182   Node *r = root();
2183   if (r != NULL) {
2184     for (uint i = r->req(); i < r->len(); ++i) {
2185       Node *n = r->in(i);
2186       if (n != NULL && n->is_SafePoint()) {
2187         r->rm_prec(i);
2188         if (n->outcnt() == 0) {
2189           igvn.remove_dead_node(n);
2190         }
2191         --i;
2192       }
2193     }
2194   }
2195 }
2196 
2197 //------------------------------Optimize---------------------------------------
2198 // Given a graph, optimize it.
2199 void Compile::Optimize() {
2200   TracePhase tp("optimizer", &timers[_t_optimizer]);
2201 
2202 #ifndef PRODUCT
2203   if (_directive->BreakAtCompileOption) {
2204     BREAKPOINT;
2205   }
2206 
2207 #endif
2208 
2209 #ifdef ASSERT
2210   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
2211   bs->verify_gc_barriers(this, BarrierSetC2::BeforeOptimize);
2212 #endif
2213 
2214   ResourceMark rm;
2215 
2216   print_inlining_reinit();
2217 
2218   NOT_PRODUCT( verify_graph_edges(); )
2219 
2220   print_method(PHASE_AFTER_PARSING);
2221 
2222  {
2223   // Iterative Global Value Numbering, including ideal transforms
2224   // Initialize IterGVN with types and values from parse-time GVN
2225   PhaseIterGVN igvn(initial_gvn());
2226 #ifdef ASSERT
2227   _modified_nodes = new (comp_arena()) Unique_Node_List(comp_arena());
2228 #endif
2229   {
2230     TracePhase tp("iterGVN", &timers[_t_iterGVN]);
2231     igvn.optimize();
2232   }
2233 
2234   if (failing())  return;
2235 
2236   print_method(PHASE_ITER_GVN1, 2);
2237 
2238   inline_incrementally(igvn);
2239 
2240   print_method(PHASE_INCREMENTAL_INLINE, 2);
2241 
2242   if (failing())  return;
2243 
2244   if (eliminate_boxing()) {
2245     // Inline valueOf() methods now.
2246     inline_boxing_calls(igvn);
2247 
2248     if (AlwaysIncrementalInline) {
2249       inline_incrementally(igvn);
2250     }
2251 
2252     print_method(PHASE_INCREMENTAL_BOXING_INLINE, 2);
2253 
2254     if (failing())  return;
2255   }
2256 
2257   // Now that all inlining is over, cut edge from root to loop
2258   // safepoints
2259   remove_root_to_sfpts_edges(igvn);
2260 
2261   // Remove the speculative part of types and clean up the graph from
2262   // the extra CastPP nodes whose only purpose is to carry them. Do
2263   // that early so that optimizations are not disrupted by the extra
2264   // CastPP nodes.
2265   remove_speculative_types(igvn);
2266 
2267   // No more new expensive nodes will be added to the list from here
2268   // so keep only the actual candidates for optimizations.
2269   cleanup_expensive_nodes(igvn);
2270 
2271   if (!failing() && RenumberLiveNodes && live_nodes() + NodeLimitFudgeFactor < unique()) {
2272     Compile::TracePhase tp("", &timers[_t_renumberLive]);
2273     initial_gvn()->replace_with(&igvn);
2274     for_igvn()->clear();
2275     Unique_Node_List new_worklist(C->comp_arena());
2276     {
2277       ResourceMark rm;
2278       PhaseRenumberLive prl = PhaseRenumberLive(initial_gvn(), for_igvn(), &new_worklist);
2279     }
2280     set_for_igvn(&new_worklist);
2281     igvn = PhaseIterGVN(initial_gvn());
2282     igvn.optimize();
2283   }
2284 
2285   // Perform escape analysis
2286   if (_do_escape_analysis && ConnectionGraph::has_candidates(this)) {
2287     if (has_loops()) {
2288       // Cleanup graph (remove dead nodes).
2289       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2290       PhaseIdealLoop::optimize(igvn, LoopOptsNone);
2291       if (major_progress()) print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
2292       if (failing())  return;
2293     }
2294     ConnectionGraph::do_analysis(this, &igvn);
2295 
2296     if (failing())  return;
2297 
2298     // Optimize out fields loads from scalar replaceable allocations.
2299     igvn.optimize();
2300     print_method(PHASE_ITER_GVN_AFTER_EA, 2);
2301 
2302     if (failing())  return;
2303 
2304     if (congraph() != NULL && macro_count() > 0) {
2305       TracePhase tp("macroEliminate", &timers[_t_macroEliminate]);
2306       PhaseMacroExpand mexp(igvn);
2307       mexp.eliminate_macro_nodes();
2308       igvn.set_delay_transform(false);
2309 
2310       igvn.optimize();
2311       print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
2312 
2313       if (failing())  return;
2314     }
2315   }
2316 
2317   // Loop transforms on the ideal graph.  Range Check Elimination,
2318   // peeling, unrolling, etc.
2319 
2320   // Set loop opts counter
2321   if((_loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
2322     {
2323       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2324       PhaseIdealLoop::optimize(igvn, LoopOptsDefault);
2325       _loop_opts_cnt--;
2326       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP1, 2);
2327       if (failing())  return;
2328     }
2329     // Loop opts pass if partial peeling occurred in previous pass
2330     if(PartialPeelLoop && major_progress() && (_loop_opts_cnt > 0)) {
2331       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2332       PhaseIdealLoop::optimize(igvn, LoopOptsSkipSplitIf);
2333       _loop_opts_cnt--;
2334       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP2, 2);
2335       if (failing())  return;
2336     }
2337     // Loop opts pass for loop-unrolling before CCP
2338     if(major_progress() && (_loop_opts_cnt > 0)) {
2339       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2340       PhaseIdealLoop::optimize(igvn, LoopOptsSkipSplitIf);
2341       _loop_opts_cnt--;
2342       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP3, 2);
2343     }
2344     if (!failing()) {
2345       // Verify that last round of loop opts produced a valid graph
2346       TracePhase tp("idealLoopVerify", &timers[_t_idealLoopVerify]);
2347       PhaseIdealLoop::verify(igvn);
2348     }
2349   }
2350   if (failing())  return;
2351 
2352   // Conditional Constant Propagation;
2353   PhaseCCP ccp( &igvn );
2354   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
2355   {
2356     TracePhase tp("ccp", &timers[_t_ccp]);
2357     ccp.do_transform();
2358   }
2359   print_method(PHASE_CPP1, 2);
2360 
2361   assert( true, "Break here to ccp.dump_old2new_map()");
2362 
2363   // Iterative Global Value Numbering, including ideal transforms
2364   {
2365     TracePhase tp("iterGVN2", &timers[_t_iterGVN2]);
2366     igvn = ccp;
2367     igvn.optimize();
2368   }
2369 
2370   print_method(PHASE_ITER_GVN2, 2);
2371 
2372   if (failing())  return;
2373 
2374   // Loop transforms on the ideal graph.  Range Check Elimination,
2375   // peeling, unrolling, etc.
2376   if (!optimize_loops(igvn, LoopOptsDefault)) {
2377     return;
2378   }
2379 
2380 #if INCLUDE_ZGC
2381   if (UseZGC) {
2382     ZBarrierSetC2::find_dominating_barriers(igvn);
2383   }
2384 #endif
2385 
2386   if (failing())  return;
2387 
2388   // Ensure that major progress is now clear
2389   C->clear_major_progress();
2390 
2391   {
2392     // Verify that all previous optimizations produced a valid graph
2393     // at least to this point, even if no loop optimizations were done.
2394     TracePhase tp("idealLoopVerify", &timers[_t_idealLoopVerify]);
2395     PhaseIdealLoop::verify(igvn);
2396   }
2397 
2398   if (range_check_cast_count() > 0) {
2399     // No more loop optimizations. Remove all range check dependent CastIINodes.
2400     C->remove_range_check_casts(igvn);
2401     igvn.optimize();
2402   }
2403 
2404 #ifdef ASSERT
2405   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
2406   bs->verify_gc_barriers(this, BarrierSetC2::BeforeExpand);
2407 #endif
2408 
2409   {
2410     TracePhase tp("macroExpand", &timers[_t_macroExpand]);
2411     PhaseMacroExpand  mex(igvn);
2412     print_method(PHASE_BEFORE_MACRO_EXPANSION, 2);
2413     if (mex.expand_macro_nodes()) {
2414       assert(failing(), "must bail out w/ explicit message");
2415       return;
2416     }
2417   }
2418 
2419   {
2420     TracePhase tp("barrierExpand", &timers[_t_barrierExpand]);
2421     print_method(PHASE_BEFORE_BARRIER_EXPAND, 2);
2422     BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
2423     if (bs->expand_barriers(this, igvn)) {
2424       assert(failing(), "must bail out w/ explicit message");
2425       return;
2426     }
2427   }
2428 
2429   if (opaque4_count() > 0) {
2430     C->remove_opaque4_nodes(igvn);
2431     igvn.optimize();
2432   }
2433 
2434   DEBUG_ONLY( _modified_nodes = NULL; )
2435  } // (End scope of igvn; run destructor if necessary for asserts.)
2436 
2437  process_print_inlining();
2438  // A method with only infinite loops has no edges entering loops from root
2439  {
2440    TracePhase tp("graphReshape", &timers[_t_graphReshaping]);
2441    if (final_graph_reshaping()) {
2442      assert(failing(), "must bail out w/ explicit message");
2443      return;
2444    }
2445  }
2446 
2447  print_method(PHASE_OPTIMIZE_FINISHED, 2);
2448 }
2449 
2450 
2451 //------------------------------Code_Gen---------------------------------------
2452 // Given a graph, generate code for it
2453 void Compile::Code_Gen() {
2454   if (failing()) {
2455     return;
2456   }
2457 
2458   // Perform instruction selection.  You might think we could reclaim Matcher
2459   // memory PDQ, but actually the Matcher is used in generating spill code.
2460   // Internals of the Matcher (including some VectorSets) must remain live
2461   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
2462   // set a bit in reclaimed memory.
2463 
2464   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2465   // nodes.  Mapping is only valid at the root of each matched subtree.
2466   NOT_PRODUCT( verify_graph_edges(); )
2467 
2468   Matcher matcher;
2469   _matcher = &matcher;
2470   {
2471     TracePhase tp("matcher", &timers[_t_matcher]);
2472     matcher.match();
2473   }
2474   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2475   // nodes.  Mapping is only valid at the root of each matched subtree.
2476   NOT_PRODUCT( verify_graph_edges(); )
2477 
2478   // If you have too many nodes, or if matching has failed, bail out
2479   check_node_count(0, "out of nodes matching instructions");
2480   if (failing()) {
2481     return;
2482   }
2483 
2484   print_method(PHASE_MATCHING, 2);
2485 
2486   // Build a proper-looking CFG
2487   PhaseCFG cfg(node_arena(), root(), matcher);
2488   _cfg = &cfg;
2489   {
2490     TracePhase tp("scheduler", &timers[_t_scheduler]);
2491     bool success = cfg.do_global_code_motion();
2492     if (!success) {
2493       return;
2494     }
2495 
2496     print_method(PHASE_GLOBAL_CODE_MOTION, 2);
2497     NOT_PRODUCT( verify_graph_edges(); )
2498     debug_only( cfg.verify(); )
2499   }
2500 
2501   PhaseChaitin regalloc(unique(), cfg, matcher, false);
2502   _regalloc = &regalloc;
2503   {
2504     TracePhase tp("regalloc", &timers[_t_registerAllocation]);
2505     // Perform register allocation.  After Chaitin, use-def chains are
2506     // no longer accurate (at spill code) and so must be ignored.
2507     // Node->LRG->reg mappings are still accurate.
2508     _regalloc->Register_Allocate();
2509 
2510     // Bail out if the allocator builds too many nodes
2511     if (failing()) {
2512       return;
2513     }
2514   }
2515 
2516   // Prior to register allocation we kept empty basic blocks in case the
2517   // the allocator needed a place to spill.  After register allocation we
2518   // are not adding any new instructions.  If any basic block is empty, we
2519   // can now safely remove it.
2520   {
2521     TracePhase tp("blockOrdering", &timers[_t_blockOrdering]);
2522     cfg.remove_empty_blocks();
2523     if (do_freq_based_layout()) {
2524       PhaseBlockLayout layout(cfg);
2525     } else {
2526       cfg.set_loop_alignment();
2527     }
2528     cfg.fixup_flow();
2529   }
2530 
2531   // Apply peephole optimizations
2532   if( OptoPeephole ) {
2533     TracePhase tp("peephole", &timers[_t_peephole]);
2534     PhasePeephole peep( _regalloc, cfg);
2535     peep.do_transform();
2536   }
2537 
2538   // Do late expand if CPU requires this.
2539   if (Matcher::require_postalloc_expand) {
2540     TracePhase tp("postalloc_expand", &timers[_t_postalloc_expand]);
2541     cfg.postalloc_expand(_regalloc);
2542   }
2543 
2544   // Convert Nodes to instruction bits in a buffer
2545   {
2546     TraceTime tp("output", &timers[_t_output], CITime);
2547     Output();
2548   }
2549 
2550   print_method(PHASE_FINAL_CODE);
2551 
2552   // He's dead, Jim.
2553   _cfg     = (PhaseCFG*)((intptr_t)0xdeadbeef);
2554   _regalloc = (PhaseChaitin*)((intptr_t)0xdeadbeef);
2555 }
2556 
2557 
2558 //------------------------------dump_asm---------------------------------------
2559 // Dump formatted assembly
2560 #ifndef PRODUCT
2561 void Compile::dump_asm(int *pcs, uint pc_limit) {
2562   bool cut_short = false;
2563   tty->print_cr("#");
2564   tty->print("#  ");  _tf->dump();  tty->cr();
2565   tty->print_cr("#");
2566 
2567   // For all blocks
2568   int pc = 0x0;                 // Program counter
2569   char starts_bundle = ' ';
2570   _regalloc->dump_frame();
2571 
2572   Node *n = NULL;
2573   for (uint i = 0; i < _cfg->number_of_blocks(); i++) {
2574     if (VMThread::should_terminate()) {
2575       cut_short = true;
2576       break;
2577     }
2578     Block* block = _cfg->get_block(i);
2579     if (block->is_connector() && !Verbose) {
2580       continue;
2581     }
2582     n = block->head();
2583     if (pcs && n->_idx < pc_limit) {
2584       tty->print("%3.3x   ", pcs[n->_idx]);
2585     } else {
2586       tty->print("      ");
2587     }
2588     block->dump_head(_cfg);
2589     if (block->is_connector()) {
2590       tty->print_cr("        # Empty connector block");
2591     } else if (block->num_preds() == 2 && block->pred(1)->is_CatchProj() && block->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
2592       tty->print_cr("        # Block is sole successor of call");
2593     }
2594 
2595     // For all instructions
2596     Node *delay = NULL;
2597     for (uint j = 0; j < block->number_of_nodes(); j++) {
2598       if (VMThread::should_terminate()) {
2599         cut_short = true;
2600         break;
2601       }
2602       n = block->get_node(j);
2603       if (valid_bundle_info(n)) {
2604         Bundle* bundle = node_bundling(n);
2605         if (bundle->used_in_unconditional_delay()) {
2606           delay = n;
2607           continue;
2608         }
2609         if (bundle->starts_bundle()) {
2610           starts_bundle = '+';
2611         }
2612       }
2613 
2614       if (WizardMode) {
2615         n->dump();
2616       }
2617 
2618       if( !n->is_Region() &&    // Dont print in the Assembly
2619           !n->is_Phi() &&       // a few noisely useless nodes
2620           !n->is_Proj() &&
2621           !n->is_MachTemp() &&
2622           !n->is_SafePointScalarObject() &&
2623           !n->is_Catch() &&     // Would be nice to print exception table targets
2624           !n->is_MergeMem() &&  // Not very interesting
2625           !n->is_top() &&       // Debug info table constants
2626           !(n->is_Con() && !n->is_Mach())// Debug info table constants
2627           ) {
2628         if (pcs && n->_idx < pc_limit)
2629           tty->print("%3.3x", pcs[n->_idx]);
2630         else
2631           tty->print("   ");
2632         tty->print(" %c ", starts_bundle);
2633         starts_bundle = ' ';
2634         tty->print("\t");
2635         n->format(_regalloc, tty);
2636         tty->cr();
2637       }
2638 
2639       // If we have an instruction with a delay slot, and have seen a delay,
2640       // then back up and print it
2641       if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
2642         assert(delay != NULL, "no unconditional delay instruction");
2643         if (WizardMode) delay->dump();
2644 
2645         if (node_bundling(delay)->starts_bundle())
2646           starts_bundle = '+';
2647         if (pcs && n->_idx < pc_limit)
2648           tty->print("%3.3x", pcs[n->_idx]);
2649         else
2650           tty->print("   ");
2651         tty->print(" %c ", starts_bundle);
2652         starts_bundle = ' ';
2653         tty->print("\t");
2654         delay->format(_regalloc, tty);
2655         tty->cr();
2656         delay = NULL;
2657       }
2658 
2659       // Dump the exception table as well
2660       if( n->is_Catch() && (Verbose || WizardMode) ) {
2661         // Print the exception table for this offset
2662         _handler_table.print_subtable_for(pc);
2663       }
2664     }
2665 
2666     if (pcs && n->_idx < pc_limit)
2667       tty->print_cr("%3.3x", pcs[n->_idx]);
2668     else
2669       tty->cr();
2670 
2671     assert(cut_short || delay == NULL, "no unconditional delay branch");
2672 
2673   } // End of per-block dump
2674   tty->cr();
2675 
2676   if (cut_short)  tty->print_cr("*** disassembly is cut short ***");
2677 }
2678 #endif
2679 
2680 //------------------------------Final_Reshape_Counts---------------------------
2681 // This class defines counters to help identify when a method
2682 // may/must be executed using hardware with only 24-bit precision.
2683 struct Final_Reshape_Counts : public StackObj {
2684   int  _call_count;             // count non-inlined 'common' calls
2685   int  _float_count;            // count float ops requiring 24-bit precision
2686   int  _double_count;           // count double ops requiring more precision
2687   int  _java_call_count;        // count non-inlined 'java' calls
2688   int  _inner_loop_count;       // count loops which need alignment
2689   VectorSet _visited;           // Visitation flags
2690   Node_List _tests;             // Set of IfNodes & PCTableNodes
2691 
2692   Final_Reshape_Counts() :
2693     _call_count(0), _float_count(0), _double_count(0),
2694     _java_call_count(0), _inner_loop_count(0),
2695     _visited( Thread::current()->resource_area() ) { }
2696 
2697   void inc_call_count  () { _call_count  ++; }
2698   void inc_float_count () { _float_count ++; }
2699   void inc_double_count() { _double_count++; }
2700   void inc_java_call_count() { _java_call_count++; }
2701   void inc_inner_loop_count() { _inner_loop_count++; }
2702 
2703   int  get_call_count  () const { return _call_count  ; }
2704   int  get_float_count () const { return _float_count ; }
2705   int  get_double_count() const { return _double_count; }
2706   int  get_java_call_count() const { return _java_call_count; }
2707   int  get_inner_loop_count() const { return _inner_loop_count; }
2708 };
2709 
2710 #ifdef ASSERT
2711 static bool oop_offset_is_sane(const TypeInstPtr* tp) {
2712   ciInstanceKlass *k = tp->klass()->as_instance_klass();
2713   // Make sure the offset goes inside the instance layout.
2714   return k->contains_field_offset(tp->offset());
2715   // Note that OffsetBot and OffsetTop are very negative.
2716 }
2717 #endif
2718 
2719 // Eliminate trivially redundant StoreCMs and accumulate their
2720 // precedence edges.
2721 void Compile::eliminate_redundant_card_marks(Node* n) {
2722   assert(n->Opcode() == Op_StoreCM, "expected StoreCM");
2723   if (n->in(MemNode::Address)->outcnt() > 1) {
2724     // There are multiple users of the same address so it might be
2725     // possible to eliminate some of the StoreCMs
2726     Node* mem = n->in(MemNode::Memory);
2727     Node* adr = n->in(MemNode::Address);
2728     Node* val = n->in(MemNode::ValueIn);
2729     Node* prev = n;
2730     bool done = false;
2731     // Walk the chain of StoreCMs eliminating ones that match.  As
2732     // long as it's a chain of single users then the optimization is
2733     // safe.  Eliminating partially redundant StoreCMs would require
2734     // cloning copies down the other paths.
2735     while (mem->Opcode() == Op_StoreCM && mem->outcnt() == 1 && !done) {
2736       if (adr == mem->in(MemNode::Address) &&
2737           val == mem->in(MemNode::ValueIn)) {
2738         // redundant StoreCM
2739         if (mem->req() > MemNode::OopStore) {
2740           // Hasn't been processed by this code yet.
2741           n->add_prec(mem->in(MemNode::OopStore));
2742         } else {
2743           // Already converted to precedence edge
2744           for (uint i = mem->req(); i < mem->len(); i++) {
2745             // Accumulate any precedence edges
2746             if (mem->in(i) != NULL) {
2747               n->add_prec(mem->in(i));
2748             }
2749           }
2750           // Everything above this point has been processed.
2751           done = true;
2752         }
2753         // Eliminate the previous StoreCM
2754         prev->set_req(MemNode::Memory, mem->in(MemNode::Memory));
2755         assert(mem->outcnt() == 0, "should be dead");
2756         mem->disconnect_inputs(NULL, this);
2757       } else {
2758         prev = mem;
2759       }
2760       mem = prev->in(MemNode::Memory);
2761     }
2762   }
2763 }
2764 
2765 //------------------------------final_graph_reshaping_impl----------------------
2766 // Implement items 1-5 from final_graph_reshaping below.
2767 void Compile::final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &frc) {
2768 
2769   if ( n->outcnt() == 0 ) return; // dead node
2770   uint nop = n->Opcode();
2771 
2772   // Check for 2-input instruction with "last use" on right input.
2773   // Swap to left input.  Implements item (2).
2774   if( n->req() == 3 &&          // two-input instruction
2775       n->in(1)->outcnt() > 1 && // left use is NOT a last use
2776       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
2777       n->in(2)->outcnt() == 1 &&// right use IS a last use
2778       !n->in(2)->is_Con() ) {   // right use is not a constant
2779     // Check for commutative opcode
2780     switch( nop ) {
2781     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddL:
2782     case Op_MaxI:  case Op_MinI:
2783     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulL:
2784     case Op_AndL:  case Op_XorL:  case Op_OrL:
2785     case Op_AndI:  case Op_XorI:  case Op_OrI: {
2786       // Move "last use" input to left by swapping inputs
2787       n->swap_edges(1, 2);
2788       break;
2789     }
2790     default:
2791       break;
2792     }
2793   }
2794 
2795 #ifdef ASSERT
2796   if( n->is_Mem() ) {
2797     int alias_idx = get_alias_index(n->as_Mem()->adr_type());
2798     assert( n->in(0) != NULL || alias_idx != Compile::AliasIdxRaw ||
2799             // oop will be recorded in oop map if load crosses safepoint
2800             n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
2801                              LoadNode::is_immutable_value(n->in(MemNode::Address))),
2802             "raw memory operations should have control edge");
2803   }
2804   if (n->is_MemBar()) {
2805     MemBarNode* mb = n->as_MemBar();
2806     if (mb->trailing_store() || mb->trailing_load_store()) {
2807       assert(mb->leading_membar()->trailing_membar() == mb, "bad membar pair");
2808       Node* mem = mb->in(MemBarNode::Precedent);
2809       assert((mb->trailing_store() && mem->is_Store() && mem->as_Store()->is_release()) ||
2810              (mb->trailing_load_store() && mem->is_LoadStore()), "missing mem op");
2811     } else if (mb->leading()) {
2812       assert(mb->trailing_membar()->leading_membar() == mb, "bad membar pair");
2813     }
2814   }
2815 #endif
2816   // Count FPU ops and common calls, implements item (3)
2817   bool gc_handled = BarrierSet::barrier_set()->barrier_set_c2()->final_graph_reshaping(this, n, nop);
2818   if (!gc_handled) {
2819     final_graph_reshaping_main_switch(n, frc, nop);
2820   }
2821 
2822   // Collect CFG split points
2823   if (n->is_MultiBranch() && !n->is_RangeCheck()) {
2824     frc._tests.push(n);
2825   }
2826 }
2827 
2828 void Compile::final_graph_reshaping_main_switch(Node* n, Final_Reshape_Counts& frc, uint nop) {
2829   switch( nop ) {
2830   // Count all float operations that may use FPU
2831   case Op_AddF:
2832   case Op_SubF:
2833   case Op_MulF:
2834   case Op_DivF:
2835   case Op_NegF:
2836   case Op_ModF:
2837   case Op_ConvI2F:
2838   case Op_ConF:
2839   case Op_CmpF:
2840   case Op_CmpF3:
2841   // case Op_ConvL2F: // longs are split into 32-bit halves
2842     frc.inc_float_count();
2843     break;
2844 
2845   case Op_ConvF2D:
2846   case Op_ConvD2F:
2847     frc.inc_float_count();
2848     frc.inc_double_count();
2849     break;
2850 
2851   // Count all double operations that may use FPU
2852   case Op_AddD:
2853   case Op_SubD:
2854   case Op_MulD:
2855   case Op_DivD:
2856   case Op_NegD:
2857   case Op_ModD:
2858   case Op_ConvI2D:
2859   case Op_ConvD2I:
2860   // case Op_ConvL2D: // handled by leaf call
2861   // case Op_ConvD2L: // handled by leaf call
2862   case Op_ConD:
2863   case Op_CmpD:
2864   case Op_CmpD3:
2865     frc.inc_double_count();
2866     break;
2867   case Op_Opaque1:              // Remove Opaque Nodes before matching
2868   case Op_Opaque2:              // Remove Opaque Nodes before matching
2869   case Op_Opaque3:
2870     n->subsume_by(n->in(1), this);
2871     break;
2872   case Op_CallStaticJava:
2873   case Op_CallJava:
2874   case Op_CallDynamicJava:
2875     frc.inc_java_call_count(); // Count java call site;
2876   case Op_CallRuntime:
2877   case Op_CallLeaf:
2878   case Op_CallLeafNoFP: {
2879     assert (n->is_Call(), "");
2880     CallNode *call = n->as_Call();
2881     // Count call sites where the FP mode bit would have to be flipped.
2882     // Do not count uncommon runtime calls:
2883     // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
2884     // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
2885     if (!call->is_CallStaticJava() || !call->as_CallStaticJava()->_name) {
2886       frc.inc_call_count();   // Count the call site
2887     } else {                  // See if uncommon argument is shared
2888       Node *n = call->in(TypeFunc::Parms);
2889       int nop = n->Opcode();
2890       // Clone shared simple arguments to uncommon calls, item (1).
2891       if (n->outcnt() > 1 &&
2892           !n->is_Proj() &&
2893           nop != Op_CreateEx &&
2894           nop != Op_CheckCastPP &&
2895           nop != Op_DecodeN &&
2896           nop != Op_DecodeNKlass &&
2897           !n->is_Mem() &&
2898           !n->is_Phi()) {
2899         Node *x = n->clone();
2900         call->set_req(TypeFunc::Parms, x);
2901       }
2902     }
2903     break;
2904   }
2905 
2906   case Op_StoreD:
2907   case Op_LoadD:
2908   case Op_LoadD_unaligned:
2909     frc.inc_double_count();
2910     goto handle_mem;
2911   case Op_StoreF:
2912   case Op_LoadF:
2913     frc.inc_float_count();
2914     goto handle_mem;
2915 
2916   case Op_StoreCM:
2917     {
2918       // Convert OopStore dependence into precedence edge
2919       Node* prec = n->in(MemNode::OopStore);
2920       n->del_req(MemNode::OopStore);
2921       n->add_prec(prec);
2922       eliminate_redundant_card_marks(n);
2923     }
2924 
2925     // fall through
2926 
2927   case Op_StoreB:
2928   case Op_StoreC:
2929   case Op_StorePConditional:
2930   case Op_StoreI:
2931   case Op_StoreL:
2932   case Op_StoreIConditional:
2933   case Op_StoreLConditional:
2934   case Op_CompareAndSwapB:
2935   case Op_CompareAndSwapS:
2936   case Op_CompareAndSwapI:
2937   case Op_CompareAndSwapL:
2938   case Op_CompareAndSwapP:
2939   case Op_CompareAndSwapN:
2940   case Op_WeakCompareAndSwapB:
2941   case Op_WeakCompareAndSwapS:
2942   case Op_WeakCompareAndSwapI:
2943   case Op_WeakCompareAndSwapL:
2944   case Op_WeakCompareAndSwapP:
2945   case Op_WeakCompareAndSwapN:
2946   case Op_CompareAndExchangeB:
2947   case Op_CompareAndExchangeS:
2948   case Op_CompareAndExchangeI:
2949   case Op_CompareAndExchangeL:
2950   case Op_CompareAndExchangeP:
2951   case Op_CompareAndExchangeN:
2952   case Op_GetAndAddS:
2953   case Op_GetAndAddB:
2954   case Op_GetAndAddI:
2955   case Op_GetAndAddL:
2956   case Op_GetAndSetS:
2957   case Op_GetAndSetB:
2958   case Op_GetAndSetI:
2959   case Op_GetAndSetL:
2960   case Op_GetAndSetP:
2961   case Op_GetAndSetN:
2962   case Op_StoreP:
2963   case Op_StoreN:
2964   case Op_StoreNKlass:
2965   case Op_LoadB:
2966   case Op_LoadUB:
2967   case Op_LoadUS:
2968   case Op_LoadI:
2969   case Op_LoadKlass:
2970   case Op_LoadNKlass:
2971   case Op_LoadL:
2972   case Op_LoadL_unaligned:
2973   case Op_LoadPLocked:
2974   case Op_LoadP:
2975   case Op_LoadN:
2976   case Op_LoadRange:
2977   case Op_LoadS: {
2978   handle_mem:
2979 #ifdef ASSERT
2980     if( VerifyOptoOopOffsets ) {
2981       MemNode* mem  = n->as_Mem();
2982       // Check to see if address types have grounded out somehow.
2983       const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
2984       assert( !tp || oop_offset_is_sane(tp), "" );
2985     }
2986 #endif
2987     break;
2988   }
2989 
2990   case Op_AddP: {               // Assert sane base pointers
2991     Node *addp = n->in(AddPNode::Address);
2992     assert( !addp->is_AddP() ||
2993             addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
2994             addp->in(AddPNode::Base) == n->in(AddPNode::Base),
2995             "Base pointers must match (addp %u)", addp->_idx );
2996 #ifdef _LP64
2997     if ((UseCompressedOops || UseCompressedClassPointers) &&
2998         addp->Opcode() == Op_ConP &&
2999         addp == n->in(AddPNode::Base) &&
3000         n->in(AddPNode::Offset)->is_Con()) {
3001       // If the transformation of ConP to ConN+DecodeN is beneficial depends
3002       // on the platform and on the compressed oops mode.
3003       // Use addressing with narrow klass to load with offset on x86.
3004       // Some platforms can use the constant pool to load ConP.
3005       // Do this transformation here since IGVN will convert ConN back to ConP.
3006       const Type* t = addp->bottom_type();
3007       bool is_oop   = t->isa_oopptr() != NULL;
3008       bool is_klass = t->isa_klassptr() != NULL;
3009 
3010       if ((is_oop   && Matcher::const_oop_prefer_decode()  ) ||
3011           (is_klass && Matcher::const_klass_prefer_decode())) {
3012         Node* nn = NULL;
3013 
3014         int op = is_oop ? Op_ConN : Op_ConNKlass;
3015 
3016         // Look for existing ConN node of the same exact type.
3017         Node* r  = root();
3018         uint cnt = r->outcnt();
3019         for (uint i = 0; i < cnt; i++) {
3020           Node* m = r->raw_out(i);
3021           if (m!= NULL && m->Opcode() == op &&
3022               m->bottom_type()->make_ptr() == t) {
3023             nn = m;
3024             break;
3025           }
3026         }
3027         if (nn != NULL) {
3028           // Decode a narrow oop to match address
3029           // [R12 + narrow_oop_reg<<3 + offset]
3030           if (is_oop) {
3031             nn = new DecodeNNode(nn, t);
3032           } else {
3033             nn = new DecodeNKlassNode(nn, t);
3034           }
3035           // Check for succeeding AddP which uses the same Base.
3036           // Otherwise we will run into the assertion above when visiting that guy.
3037           for (uint i = 0; i < n->outcnt(); ++i) {
3038             Node *out_i = n->raw_out(i);
3039             if (out_i && out_i->is_AddP() && out_i->in(AddPNode::Base) == addp) {
3040               out_i->set_req(AddPNode::Base, nn);
3041 #ifdef ASSERT
3042               for (uint j = 0; j < out_i->outcnt(); ++j) {
3043                 Node *out_j = out_i->raw_out(j);
3044                 assert(out_j == NULL || !out_j->is_AddP() || out_j->in(AddPNode::Base) != addp,
3045                        "more than 2 AddP nodes in a chain (out_j %u)", out_j->_idx);
3046               }
3047 #endif
3048             }
3049           }
3050           n->set_req(AddPNode::Base, nn);
3051           n->set_req(AddPNode::Address, nn);
3052           if (addp->outcnt() == 0) {
3053             addp->disconnect_inputs(NULL, this);
3054           }
3055         }
3056       }
3057     }
3058 #endif
3059     // platform dependent reshaping of the address expression
3060     reshape_address(n->as_AddP());
3061     break;
3062   }
3063 
3064   case Op_CastPP: {
3065     // Remove CastPP nodes to gain more freedom during scheduling but
3066     // keep the dependency they encode as control or precedence edges
3067     // (if control is set already) on memory operations. Some CastPP
3068     // nodes don't have a control (don't carry a dependency): skip
3069     // those.
3070     if (n->in(0) != NULL) {
3071       ResourceMark rm;
3072       Unique_Node_List wq;
3073       wq.push(n);
3074       for (uint next = 0; next < wq.size(); ++next) {
3075         Node *m = wq.at(next);
3076         for (DUIterator_Fast imax, i = m->fast_outs(imax); i < imax; i++) {
3077           Node* use = m->fast_out(i);
3078           if (use->is_Mem() || use->is_EncodeNarrowPtr()) {
3079             use->ensure_control_or_add_prec(n->in(0));
3080           } else {
3081             switch(use->Opcode()) {
3082             case Op_AddP:
3083             case Op_DecodeN:
3084             case Op_DecodeNKlass:
3085             case Op_CheckCastPP:
3086             case Op_CastPP:
3087               wq.push(use);
3088               break;
3089             }
3090           }
3091         }
3092       }
3093     }
3094     const bool is_LP64 = LP64_ONLY(true) NOT_LP64(false);
3095     if (is_LP64 && n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
3096       Node* in1 = n->in(1);
3097       const Type* t = n->bottom_type();
3098       Node* new_in1 = in1->clone();
3099       new_in1->as_DecodeN()->set_type(t);
3100 
3101       if (!Matcher::narrow_oop_use_complex_address()) {
3102         //
3103         // x86, ARM and friends can handle 2 adds in addressing mode
3104         // and Matcher can fold a DecodeN node into address by using
3105         // a narrow oop directly and do implicit NULL check in address:
3106         //
3107         // [R12 + narrow_oop_reg<<3 + offset]
3108         // NullCheck narrow_oop_reg
3109         //
3110         // On other platforms (Sparc) we have to keep new DecodeN node and
3111         // use it to do implicit NULL check in address:
3112         //
3113         // decode_not_null narrow_oop_reg, base_reg
3114         // [base_reg + offset]
3115         // NullCheck base_reg
3116         //
3117         // Pin the new DecodeN node to non-null path on these platform (Sparc)
3118         // to keep the information to which NULL check the new DecodeN node
3119         // corresponds to use it as value in implicit_null_check().
3120         //
3121         new_in1->set_req(0, n->in(0));
3122       }
3123 
3124       n->subsume_by(new_in1, this);
3125       if (in1->outcnt() == 0) {
3126         in1->disconnect_inputs(NULL, this);
3127       }
3128     } else {
3129       n->subsume_by(n->in(1), this);
3130       if (n->outcnt() == 0) {
3131         n->disconnect_inputs(NULL, this);
3132       }
3133     }
3134     break;
3135   }
3136 #ifdef _LP64
3137   case Op_CmpP:
3138     // Do this transformation here to preserve CmpPNode::sub() and
3139     // other TypePtr related Ideal optimizations (for example, ptr nullness).
3140     if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
3141       Node* in1 = n->in(1);
3142       Node* in2 = n->in(2);
3143       if (!in1->is_DecodeNarrowPtr()) {
3144         in2 = in1;
3145         in1 = n->in(2);
3146       }
3147       assert(in1->is_DecodeNarrowPtr(), "sanity");
3148 
3149       Node* new_in2 = NULL;
3150       if (in2->is_DecodeNarrowPtr()) {
3151         assert(in2->Opcode() == in1->Opcode(), "must be same node type");
3152         new_in2 = in2->in(1);
3153       } else if (in2->Opcode() == Op_ConP) {
3154         const Type* t = in2->bottom_type();
3155         if (t == TypePtr::NULL_PTR) {
3156           assert(in1->is_DecodeN(), "compare klass to null?");
3157           // Don't convert CmpP null check into CmpN if compressed
3158           // oops implicit null check is not generated.
3159           // This will allow to generate normal oop implicit null check.
3160           if (Matcher::gen_narrow_oop_implicit_null_checks())
3161             new_in2 = ConNode::make(TypeNarrowOop::NULL_PTR);
3162           //
3163           // This transformation together with CastPP transformation above
3164           // will generated code for implicit NULL checks for compressed oops.
3165           //
3166           // The original code after Optimize()
3167           //
3168           //    LoadN memory, narrow_oop_reg
3169           //    decode narrow_oop_reg, base_reg
3170           //    CmpP base_reg, NULL
3171           //    CastPP base_reg // NotNull
3172           //    Load [base_reg + offset], val_reg
3173           //
3174           // after these transformations will be
3175           //
3176           //    LoadN memory, narrow_oop_reg
3177           //    CmpN narrow_oop_reg, NULL
3178           //    decode_not_null narrow_oop_reg, base_reg
3179           //    Load [base_reg + offset], val_reg
3180           //
3181           // and the uncommon path (== NULL) will use narrow_oop_reg directly
3182           // since narrow oops can be used in debug info now (see the code in
3183           // final_graph_reshaping_walk()).
3184           //
3185           // At the end the code will be matched to
3186           // on x86:
3187           //
3188           //    Load_narrow_oop memory, narrow_oop_reg
3189           //    Load [R12 + narrow_oop_reg<<3 + offset], val_reg
3190           //    NullCheck narrow_oop_reg
3191           //
3192           // and on sparc:
3193           //
3194           //    Load_narrow_oop memory, narrow_oop_reg
3195           //    decode_not_null narrow_oop_reg, base_reg
3196           //    Load [base_reg + offset], val_reg
3197           //    NullCheck base_reg
3198           //
3199         } else if (t->isa_oopptr()) {
3200           new_in2 = ConNode::make(t->make_narrowoop());
3201         } else if (t->isa_klassptr()) {
3202           new_in2 = ConNode::make(t->make_narrowklass());
3203         }
3204       }
3205       if (new_in2 != NULL) {
3206         Node* cmpN = new CmpNNode(in1->in(1), new_in2);
3207         n->subsume_by(cmpN, this);
3208         if (in1->outcnt() == 0) {
3209           in1->disconnect_inputs(NULL, this);
3210         }
3211         if (in2->outcnt() == 0) {
3212           in2->disconnect_inputs(NULL, this);
3213         }
3214       }
3215     }
3216     break;
3217 
3218   case Op_DecodeN:
3219   case Op_DecodeNKlass:
3220     assert(!n->in(1)->is_EncodeNarrowPtr(), "should be optimized out");
3221     // DecodeN could be pinned when it can't be fold into
3222     // an address expression, see the code for Op_CastPP above.
3223     assert(n->in(0) == NULL || (UseCompressedOops && !Matcher::narrow_oop_use_complex_address()), "no control");
3224     break;
3225 
3226   case Op_EncodeP:
3227   case Op_EncodePKlass: {
3228     Node* in1 = n->in(1);
3229     if (in1->is_DecodeNarrowPtr()) {
3230       n->subsume_by(in1->in(1), this);
3231     } else if (in1->Opcode() == Op_ConP) {
3232       const Type* t = in1->bottom_type();
3233       if (t == TypePtr::NULL_PTR) {
3234         assert(t->isa_oopptr(), "null klass?");
3235         n->subsume_by(ConNode::make(TypeNarrowOop::NULL_PTR), this);
3236       } else if (t->isa_oopptr()) {
3237         n->subsume_by(ConNode::make(t->make_narrowoop()), this);
3238       } else if (t->isa_klassptr()) {
3239         n->subsume_by(ConNode::make(t->make_narrowklass()), this);
3240       }
3241     }
3242     if (in1->outcnt() == 0) {
3243       in1->disconnect_inputs(NULL, this);
3244     }
3245     break;
3246   }
3247 
3248   case Op_Proj: {
3249     if (OptimizeStringConcat) {
3250       ProjNode* p = n->as_Proj();
3251       if (p->_is_io_use) {
3252         // Separate projections were used for the exception path which
3253         // are normally removed by a late inline.  If it wasn't inlined
3254         // then they will hang around and should just be replaced with
3255         // the original one.
3256         Node* proj = NULL;
3257         // Replace with just one
3258         for (SimpleDUIterator i(p->in(0)); i.has_next(); i.next()) {
3259           Node *use = i.get();
3260           if (use->is_Proj() && p != use && use->as_Proj()->_con == p->_con) {
3261             proj = use;
3262             break;
3263           }
3264         }
3265         assert(proj != NULL || p->_con == TypeFunc::I_O, "io may be dropped at an infinite loop");
3266         if (proj != NULL) {
3267           p->subsume_by(proj, this);
3268         }
3269       }
3270     }
3271     break;
3272   }
3273 
3274   case Op_Phi:
3275     if (n->as_Phi()->bottom_type()->isa_narrowoop() || n->as_Phi()->bottom_type()->isa_narrowklass()) {
3276       // The EncodeP optimization may create Phi with the same edges
3277       // for all paths. It is not handled well by Register Allocator.
3278       Node* unique_in = n->in(1);
3279       assert(unique_in != NULL, "");
3280       uint cnt = n->req();
3281       for (uint i = 2; i < cnt; i++) {
3282         Node* m = n->in(i);
3283         assert(m != NULL, "");
3284         if (unique_in != m)
3285           unique_in = NULL;
3286       }
3287       if (unique_in != NULL) {
3288         n->subsume_by(unique_in, this);
3289       }
3290     }
3291     break;
3292 
3293 #endif
3294 
3295 #ifdef ASSERT
3296   case Op_CastII:
3297     // Verify that all range check dependent CastII nodes were removed.
3298     if (n->isa_CastII()->has_range_check()) {
3299       n->dump(3);
3300       assert(false, "Range check dependent CastII node was not removed");
3301     }
3302     break;
3303 #endif
3304 
3305   case Op_ModI:
3306     if (UseDivMod) {
3307       // Check if a%b and a/b both exist
3308       Node* d = n->find_similar(Op_DivI);
3309       if (d) {
3310         // Replace them with a fused divmod if supported
3311         if (Matcher::has_match_rule(Op_DivModI)) {
3312           DivModINode* divmod = DivModINode::make(n);
3313           d->subsume_by(divmod->div_proj(), this);
3314           n->subsume_by(divmod->mod_proj(), this);
3315         } else {
3316           // replace a%b with a-((a/b)*b)
3317           Node* mult = new MulINode(d, d->in(2));
3318           Node* sub  = new SubINode(d->in(1), mult);
3319           n->subsume_by(sub, this);
3320         }
3321       }
3322     }
3323     break;
3324 
3325   case Op_ModL:
3326     if (UseDivMod) {
3327       // Check if a%b and a/b both exist
3328       Node* d = n->find_similar(Op_DivL);
3329       if (d) {
3330         // Replace them with a fused divmod if supported
3331         if (Matcher::has_match_rule(Op_DivModL)) {
3332           DivModLNode* divmod = DivModLNode::make(n);
3333           d->subsume_by(divmod->div_proj(), this);
3334           n->subsume_by(divmod->mod_proj(), this);
3335         } else {
3336           // replace a%b with a-((a/b)*b)
3337           Node* mult = new MulLNode(d, d->in(2));
3338           Node* sub  = new SubLNode(d->in(1), mult);
3339           n->subsume_by(sub, this);
3340         }
3341       }
3342     }
3343     break;
3344 
3345   case Op_LoadVector:
3346   case Op_StoreVector:
3347     break;
3348 
3349   case Op_AddReductionVI:
3350   case Op_AddReductionVL:
3351   case Op_AddReductionVF:
3352   case Op_AddReductionVD:
3353   case Op_MulReductionVI:
3354   case Op_MulReductionVL:
3355   case Op_MulReductionVF:
3356   case Op_MulReductionVD:
3357   case Op_MinReductionV:
3358   case Op_MaxReductionV:
3359     break;
3360 
3361   case Op_PackB:
3362   case Op_PackS:
3363   case Op_PackI:
3364   case Op_PackF:
3365   case Op_PackL:
3366   case Op_PackD:
3367     if (n->req()-1 > 2) {
3368       // Replace many operand PackNodes with a binary tree for matching
3369       PackNode* p = (PackNode*) n;
3370       Node* btp = p->binary_tree_pack(1, n->req());
3371       n->subsume_by(btp, this);
3372     }
3373     break;
3374   case Op_Loop:
3375   case Op_CountedLoop:
3376   case Op_OuterStripMinedLoop:
3377     if (n->as_Loop()->is_inner_loop()) {
3378       frc.inc_inner_loop_count();
3379     }
3380     n->as_Loop()->verify_strip_mined(0);
3381     break;
3382   case Op_LShiftI:
3383   case Op_RShiftI:
3384   case Op_URShiftI:
3385   case Op_LShiftL:
3386   case Op_RShiftL:
3387   case Op_URShiftL:
3388     if (Matcher::need_masked_shift_count) {
3389       // The cpu's shift instructions don't restrict the count to the
3390       // lower 5/6 bits. We need to do the masking ourselves.
3391       Node* in2 = n->in(2);
3392       juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
3393       const TypeInt* t = in2->find_int_type();
3394       if (t != NULL && t->is_con()) {
3395         juint shift = t->get_con();
3396         if (shift > mask) { // Unsigned cmp
3397           n->set_req(2, ConNode::make(TypeInt::make(shift & mask)));
3398         }
3399       } else {
3400         if (t == NULL || t->_lo < 0 || t->_hi > (int)mask) {
3401           Node* shift = new AndINode(in2, ConNode::make(TypeInt::make(mask)));
3402           n->set_req(2, shift);
3403         }
3404       }
3405       if (in2->outcnt() == 0) { // Remove dead node
3406         in2->disconnect_inputs(NULL, this);
3407       }
3408     }
3409     break;
3410   case Op_MemBarStoreStore:
3411   case Op_MemBarRelease:
3412     // Break the link with AllocateNode: it is no longer useful and
3413     // confuses register allocation.
3414     if (n->req() > MemBarNode::Precedent) {
3415       n->set_req(MemBarNode::Precedent, top());
3416     }
3417     break;
3418   case Op_MemBarAcquire: {
3419     if (n->as_MemBar()->trailing_load() && n->req() > MemBarNode::Precedent) {
3420       // At parse time, the trailing MemBarAcquire for a volatile load
3421       // is created with an edge to the load. After optimizations,
3422       // that input may be a chain of Phis. If those phis have no
3423       // other use, then the MemBarAcquire keeps them alive and
3424       // register allocation can be confused.
3425       ResourceMark rm;
3426       Unique_Node_List wq;
3427       wq.push(n->in(MemBarNode::Precedent));
3428       n->set_req(MemBarNode::Precedent, top());
3429       while (wq.size() > 0) {
3430         Node* m = wq.pop();
3431         if (m->outcnt() == 0) {
3432           for (uint j = 0; j < m->req(); j++) {
3433             Node* in = m->in(j);
3434             if (in != NULL) {
3435               wq.push(in);
3436             }
3437           }
3438           m->disconnect_inputs(NULL, this);
3439         }
3440       }
3441     }
3442     break;
3443   }
3444   case Op_RangeCheck: {
3445     RangeCheckNode* rc = n->as_RangeCheck();
3446     Node* iff = new IfNode(rc->in(0), rc->in(1), rc->_prob, rc->_fcnt);
3447     n->subsume_by(iff, this);
3448     frc._tests.push(iff);
3449     break;
3450   }
3451   case Op_ConvI2L: {
3452     if (!Matcher::convi2l_type_required) {
3453       // Code generation on some platforms doesn't need accurate
3454       // ConvI2L types. Widening the type can help remove redundant
3455       // address computations.
3456       n->as_Type()->set_type(TypeLong::INT);
3457       ResourceMark rm;
3458       Node_List wq;
3459       wq.push(n);
3460       for (uint next = 0; next < wq.size(); next++) {
3461         Node *m = wq.at(next);
3462 
3463         for(;;) {
3464           // Loop over all nodes with identical inputs edges as m
3465           Node* k = m->find_similar(m->Opcode());
3466           if (k == NULL) {
3467             break;
3468           }
3469           // Push their uses so we get a chance to remove node made
3470           // redundant
3471           for (DUIterator_Fast imax, i = k->fast_outs(imax); i < imax; i++) {
3472             Node* u = k->fast_out(i);
3473             assert(!wq.contains(u), "shouldn't process one node several times");
3474             if (u->Opcode() == Op_LShiftL ||
3475                 u->Opcode() == Op_AddL ||
3476                 u->Opcode() == Op_SubL ||
3477                 u->Opcode() == Op_AddP) {
3478               wq.push(u);
3479             }
3480           }
3481           // Replace all nodes with identical edges as m with m
3482           k->subsume_by(m, this);
3483         }
3484       }
3485     }
3486     break;
3487   }
3488   case Op_CmpUL: {
3489     if (!Matcher::has_match_rule(Op_CmpUL)) {
3490       // No support for unsigned long comparisons
3491       ConINode* sign_pos = new ConINode(TypeInt::make(BitsPerLong - 1));
3492       Node* sign_bit_mask = new RShiftLNode(n->in(1), sign_pos);
3493       Node* orl = new OrLNode(n->in(1), sign_bit_mask);
3494       ConLNode* remove_sign_mask = new ConLNode(TypeLong::make(max_jlong));
3495       Node* andl = new AndLNode(orl, remove_sign_mask);
3496       Node* cmp = new CmpLNode(andl, n->in(2));
3497       n->subsume_by(cmp, this);
3498     }
3499     break;
3500   }
3501   default:
3502     assert(!n->is_Call(), "");
3503     assert(!n->is_Mem(), "");
3504     assert(nop != Op_ProfileBoolean, "should be eliminated during IGVN");
3505     break;
3506   }
3507 }
3508 
3509 //------------------------------final_graph_reshaping_walk---------------------
3510 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
3511 // requires that the walk visits a node's inputs before visiting the node.
3512 void Compile::final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Reshape_Counts &frc ) {
3513   ResourceArea *area = Thread::current()->resource_area();
3514   Unique_Node_List sfpt(area);
3515 
3516   frc._visited.set(root->_idx); // first, mark node as visited
3517   uint cnt = root->req();
3518   Node *n = root;
3519   uint  i = 0;
3520   while (true) {
3521     if (i < cnt) {
3522       // Place all non-visited non-null inputs onto stack
3523       Node* m = n->in(i);
3524       ++i;
3525       if (m != NULL && !frc._visited.test_set(m->_idx)) {
3526         if (m->is_SafePoint() && m->as_SafePoint()->jvms() != NULL) {
3527           // compute worst case interpreter size in case of a deoptimization
3528           update_interpreter_frame_size(m->as_SafePoint()->jvms()->interpreter_frame_size());
3529 
3530           sfpt.push(m);
3531         }
3532         cnt = m->req();
3533         nstack.push(n, i); // put on stack parent and next input's index
3534         n = m;
3535         i = 0;
3536       }
3537     } else {
3538       // Now do post-visit work
3539       final_graph_reshaping_impl( n, frc );
3540       if (nstack.is_empty())
3541         break;             // finished
3542       n = nstack.node();   // Get node from stack
3543       cnt = n->req();
3544       i = nstack.index();
3545       nstack.pop();        // Shift to the next node on stack
3546     }
3547   }
3548 
3549   // Skip next transformation if compressed oops are not used.
3550   if ((UseCompressedOops && !Matcher::gen_narrow_oop_implicit_null_checks()) ||
3551       (!UseCompressedOops && !UseCompressedClassPointers))
3552     return;
3553 
3554   // Go over safepoints nodes to skip DecodeN/DecodeNKlass nodes for debug edges.
3555   // It could be done for an uncommon traps or any safepoints/calls
3556   // if the DecodeN/DecodeNKlass node is referenced only in a debug info.
3557   while (sfpt.size() > 0) {
3558     n = sfpt.pop();
3559     JVMState *jvms = n->as_SafePoint()->jvms();
3560     assert(jvms != NULL, "sanity");
3561     int start = jvms->debug_start();
3562     int end   = n->req();
3563     bool is_uncommon = (n->is_CallStaticJava() &&
3564                         n->as_CallStaticJava()->uncommon_trap_request() != 0);
3565     for (int j = start; j < end; j++) {
3566       Node* in = n->in(j);
3567       if (in->is_DecodeNarrowPtr()) {
3568         bool safe_to_skip = true;
3569         if (!is_uncommon ) {
3570           // Is it safe to skip?
3571           for (uint i = 0; i < in->outcnt(); i++) {
3572             Node* u = in->raw_out(i);
3573             if (!u->is_SafePoint() ||
3574                 (u->is_Call() && u->as_Call()->has_non_debug_use(n))) {
3575               safe_to_skip = false;
3576             }
3577           }
3578         }
3579         if (safe_to_skip) {
3580           n->set_req(j, in->in(1));
3581         }
3582         if (in->outcnt() == 0) {
3583           in->disconnect_inputs(NULL, this);
3584         }
3585       }
3586     }
3587   }
3588 }
3589 
3590 //------------------------------final_graph_reshaping--------------------------
3591 // Final Graph Reshaping.
3592 //
3593 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
3594 //     and not commoned up and forced early.  Must come after regular
3595 //     optimizations to avoid GVN undoing the cloning.  Clone constant
3596 //     inputs to Loop Phis; these will be split by the allocator anyways.
3597 //     Remove Opaque nodes.
3598 // (2) Move last-uses by commutative operations to the left input to encourage
3599 //     Intel update-in-place two-address operations and better register usage
3600 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
3601 //     calls canonicalizing them back.
3602 // (3) Count the number of double-precision FP ops, single-precision FP ops
3603 //     and call sites.  On Intel, we can get correct rounding either by
3604 //     forcing singles to memory (requires extra stores and loads after each
3605 //     FP bytecode) or we can set a rounding mode bit (requires setting and
3606 //     clearing the mode bit around call sites).  The mode bit is only used
3607 //     if the relative frequency of single FP ops to calls is low enough.
3608 //     This is a key transform for SPEC mpeg_audio.
3609 // (4) Detect infinite loops; blobs of code reachable from above but not
3610 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
3611 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
3612 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
3613 //     Detection is by looking for IfNodes where only 1 projection is
3614 //     reachable from below or CatchNodes missing some targets.
3615 // (5) Assert for insane oop offsets in debug mode.
3616 
3617 bool Compile::final_graph_reshaping() {
3618   // an infinite loop may have been eliminated by the optimizer,
3619   // in which case the graph will be empty.
3620   if (root()->req() == 1) {
3621     record_method_not_compilable("trivial infinite loop");
3622     return true;
3623   }
3624 
3625   // Expensive nodes have their control input set to prevent the GVN
3626   // from freely commoning them. There's no GVN beyond this point so
3627   // no need to keep the control input. We want the expensive nodes to
3628   // be freely moved to the least frequent code path by gcm.
3629   assert(OptimizeExpensiveOps || expensive_count() == 0, "optimization off but list non empty?");
3630   for (int i = 0; i < expensive_count(); i++) {
3631     _expensive_nodes->at(i)->set_req(0, NULL);
3632   }
3633 
3634   Final_Reshape_Counts frc;
3635 
3636   // Visit everybody reachable!
3637   // Allocate stack of size C->live_nodes()/2 to avoid frequent realloc
3638   Node_Stack nstack(live_nodes() >> 1);
3639   final_graph_reshaping_walk(nstack, root(), frc);
3640 
3641   // Check for unreachable (from below) code (i.e., infinite loops).
3642   for( uint i = 0; i < frc._tests.size(); i++ ) {
3643     MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
3644     // Get number of CFG targets.
3645     // Note that PCTables include exception targets after calls.
3646     uint required_outcnt = n->required_outcnt();
3647     if (n->outcnt() != required_outcnt) {
3648       // Check for a few special cases.  Rethrow Nodes never take the
3649       // 'fall-thru' path, so expected kids is 1 less.
3650       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
3651         if (n->in(0)->in(0)->is_Call()) {
3652           CallNode *call = n->in(0)->in(0)->as_Call();
3653           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
3654             required_outcnt--;      // Rethrow always has 1 less kid
3655           } else if (call->req() > TypeFunc::Parms &&
3656                      call->is_CallDynamicJava()) {
3657             // Check for null receiver. In such case, the optimizer has
3658             // detected that the virtual call will always result in a null
3659             // pointer exception. The fall-through projection of this CatchNode
3660             // will not be populated.
3661             Node *arg0 = call->in(TypeFunc::Parms);
3662             if (arg0->is_Type() &&
3663                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
3664               required_outcnt--;
3665             }
3666           } else if (call->entry_point() == OptoRuntime::new_array_Java() &&
3667                      call->req() > TypeFunc::Parms+1 &&
3668                      call->is_CallStaticJava()) {
3669             // Check for negative array length. In such case, the optimizer has
3670             // detected that the allocation attempt will always result in an
3671             // exception. There is no fall-through projection of this CatchNode .
3672             Node *arg1 = call->in(TypeFunc::Parms+1);
3673             if (arg1->is_Type() &&
3674                 arg1->as_Type()->type()->join(TypeInt::POS)->empty()) {
3675               required_outcnt--;
3676             }
3677           }
3678         }
3679       }
3680       // Recheck with a better notion of 'required_outcnt'
3681       if (n->outcnt() != required_outcnt) {
3682         record_method_not_compilable("malformed control flow");
3683         return true;            // Not all targets reachable!
3684       }
3685     }
3686     // Check that I actually visited all kids.  Unreached kids
3687     // must be infinite loops.
3688     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
3689       if (!frc._visited.test(n->fast_out(j)->_idx)) {
3690         record_method_not_compilable("infinite loop");
3691         return true;            // Found unvisited kid; must be unreach
3692       }
3693 
3694     // Here so verification code in final_graph_reshaping_walk()
3695     // always see an OuterStripMinedLoopEnd
3696     if (n->is_OuterStripMinedLoopEnd()) {
3697       IfNode* init_iff = n->as_If();
3698       Node* iff = new IfNode(init_iff->in(0), init_iff->in(1), init_iff->_prob, init_iff->_fcnt);
3699       n->subsume_by(iff, this);
3700     }
3701   }
3702 
3703   // If original bytecodes contained a mixture of floats and doubles
3704   // check if the optimizer has made it homogenous, item (3).
3705   if( Use24BitFPMode && Use24BitFP && UseSSE == 0 &&
3706       frc.get_float_count() > 32 &&
3707       frc.get_double_count() == 0 &&
3708       (10 * frc.get_call_count() < frc.get_float_count()) ) {
3709     set_24_bit_selection_and_mode( false,  true );
3710   }
3711 
3712   set_java_calls(frc.get_java_call_count());
3713   set_inner_loops(frc.get_inner_loop_count());
3714 
3715   // No infinite loops, no reason to bail out.
3716   return false;
3717 }
3718 
3719 //-----------------------------too_many_traps----------------------------------
3720 // Report if there are too many traps at the current method and bci.
3721 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
3722 bool Compile::too_many_traps(ciMethod* method,
3723                              int bci,
3724                              Deoptimization::DeoptReason reason) {
3725   ciMethodData* md = method->method_data();
3726   if (md->is_empty()) {
3727     // Assume the trap has not occurred, or that it occurred only
3728     // because of a transient condition during start-up in the interpreter.
3729     return false;
3730   }
3731   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
3732   if (md->has_trap_at(bci, m, reason) != 0) {
3733     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
3734     // Also, if there are multiple reasons, or if there is no per-BCI record,
3735     // assume the worst.
3736     if (log())
3737       log()->elem("observe trap='%s' count='%d'",
3738                   Deoptimization::trap_reason_name(reason),
3739                   md->trap_count(reason));
3740     return true;
3741   } else {
3742     // Ignore method/bci and see if there have been too many globally.
3743     return too_many_traps(reason, md);
3744   }
3745 }
3746 
3747 // Less-accurate variant which does not require a method and bci.
3748 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
3749                              ciMethodData* logmd) {
3750   if (trap_count(reason) >= Deoptimization::per_method_trap_limit(reason)) {
3751     // Too many traps globally.
3752     // Note that we use cumulative trap_count, not just md->trap_count.
3753     if (log()) {
3754       int mcount = (logmd == NULL)? -1: (int)logmd->trap_count(reason);
3755       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
3756                   Deoptimization::trap_reason_name(reason),
3757                   mcount, trap_count(reason));
3758     }
3759     return true;
3760   } else {
3761     // The coast is clear.
3762     return false;
3763   }
3764 }
3765 
3766 //--------------------------too_many_recompiles--------------------------------
3767 // Report if there are too many recompiles at the current method and bci.
3768 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
3769 // Is not eager to return true, since this will cause the compiler to use
3770 // Action_none for a trap point, to avoid too many recompilations.
3771 bool Compile::too_many_recompiles(ciMethod* method,
3772                                   int bci,
3773                                   Deoptimization::DeoptReason reason) {
3774   ciMethodData* md = method->method_data();
3775   if (md->is_empty()) {
3776     // Assume the trap has not occurred, or that it occurred only
3777     // because of a transient condition during start-up in the interpreter.
3778     return false;
3779   }
3780   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
3781   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
3782   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
3783   Deoptimization::DeoptReason per_bc_reason
3784     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
3785   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
3786   if ((per_bc_reason == Deoptimization::Reason_none
3787        || md->has_trap_at(bci, m, reason) != 0)
3788       // The trap frequency measure we care about is the recompile count:
3789       && md->trap_recompiled_at(bci, m)
3790       && md->overflow_recompile_count() >= bc_cutoff) {
3791     // Do not emit a trap here if it has already caused recompilations.
3792     // Also, if there are multiple reasons, or if there is no per-BCI record,
3793     // assume the worst.
3794     if (log())
3795       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
3796                   Deoptimization::trap_reason_name(reason),
3797                   md->trap_count(reason),
3798                   md->overflow_recompile_count());
3799     return true;
3800   } else if (trap_count(reason) != 0
3801              && decompile_count() >= m_cutoff) {
3802     // Too many recompiles globally, and we have seen this sort of trap.
3803     // Use cumulative decompile_count, not just md->decompile_count.
3804     if (log())
3805       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
3806                   Deoptimization::trap_reason_name(reason),
3807                   md->trap_count(reason), trap_count(reason),
3808                   md->decompile_count(), decompile_count());
3809     return true;
3810   } else {
3811     // The coast is clear.
3812     return false;
3813   }
3814 }
3815 
3816 // Compute when not to trap. Used by matching trap based nodes and
3817 // NullCheck optimization.
3818 void Compile::set_allowed_deopt_reasons() {
3819   _allowed_reasons = 0;
3820   if (is_method_compilation()) {
3821     for (int rs = (int)Deoptimization::Reason_none+1; rs < Compile::trapHistLength; rs++) {
3822       assert(rs < BitsPerInt, "recode bit map");
3823       if (!too_many_traps((Deoptimization::DeoptReason) rs)) {
3824         _allowed_reasons |= nth_bit(rs);
3825       }
3826     }
3827   }
3828 }
3829 
3830 bool Compile::is_compiling_clinit_for(ciKlass* k) {
3831   ciMethod* root = method(); // the root method of compilation
3832   return root->is_static_initializer() && root->holder() == k; // access in the context of clinit
3833 }
3834 
3835 #ifndef PRODUCT
3836 //------------------------------verify_graph_edges---------------------------
3837 // Walk the Graph and verify that there is a one-to-one correspondence
3838 // between Use-Def edges and Def-Use edges in the graph.
3839 void Compile::verify_graph_edges(bool no_dead_code) {
3840   if (VerifyGraphEdges) {
3841     ResourceArea *area = Thread::current()->resource_area();
3842     Unique_Node_List visited(area);
3843     // Call recursive graph walk to check edges
3844     _root->verify_edges(visited);
3845     if (no_dead_code) {
3846       // Now make sure that no visited node is used by an unvisited node.
3847       bool dead_nodes = false;
3848       Unique_Node_List checked(area);
3849       while (visited.size() > 0) {
3850         Node* n = visited.pop();
3851         checked.push(n);
3852         for (uint i = 0; i < n->outcnt(); i++) {
3853           Node* use = n->raw_out(i);
3854           if (checked.member(use))  continue;  // already checked
3855           if (visited.member(use))  continue;  // already in the graph
3856           if (use->is_Con())        continue;  // a dead ConNode is OK
3857           // At this point, we have found a dead node which is DU-reachable.
3858           if (!dead_nodes) {
3859             tty->print_cr("*** Dead nodes reachable via DU edges:");
3860             dead_nodes = true;
3861           }
3862           use->dump(2);
3863           tty->print_cr("---");
3864           checked.push(use);  // No repeats; pretend it is now checked.
3865         }
3866       }
3867       assert(!dead_nodes, "using nodes must be reachable from root");
3868     }
3869   }
3870 }
3871 #endif
3872 
3873 // The Compile object keeps track of failure reasons separately from the ciEnv.
3874 // This is required because there is not quite a 1-1 relation between the
3875 // ciEnv and its compilation task and the Compile object.  Note that one
3876 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
3877 // to backtrack and retry without subsuming loads.  Other than this backtracking
3878 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
3879 // by the logic in C2Compiler.
3880 void Compile::record_failure(const char* reason) {
3881   if (log() != NULL) {
3882     log()->elem("failure reason='%s' phase='compile'", reason);
3883   }
3884   if (_failure_reason == NULL) {
3885     // Record the first failure reason.
3886     _failure_reason = reason;
3887   }
3888 
3889   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
3890     C->print_method(PHASE_FAILURE);
3891   }
3892   _root = NULL;  // flush the graph, too
3893 }
3894 
3895 Compile::TracePhase::TracePhase(const char* name, elapsedTimer* accumulator)
3896   : TraceTime(name, accumulator, CITime, CITimeVerbose),
3897     _phase_name(name), _dolog(CITimeVerbose)
3898 {
3899   if (_dolog) {
3900     C = Compile::current();
3901     _log = C->log();
3902   } else {
3903     C = NULL;
3904     _log = NULL;
3905   }
3906   if (_log != NULL) {
3907     _log->begin_head("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
3908     _log->stamp();
3909     _log->end_head();
3910   }
3911 }
3912 
3913 Compile::TracePhase::~TracePhase() {
3914 
3915   C = Compile::current();
3916   if (_dolog) {
3917     _log = C->log();
3918   } else {
3919     _log = NULL;
3920   }
3921 
3922 #ifdef ASSERT
3923   if (PrintIdealNodeCount) {
3924     tty->print_cr("phase name='%s' nodes='%d' live='%d' live_graph_walk='%d'",
3925                   _phase_name, C->unique(), C->live_nodes(), C->count_live_nodes_by_graph_walk());
3926   }
3927 
3928   if (VerifyIdealNodeCount) {
3929     Compile::current()->print_missing_nodes();
3930   }
3931 #endif
3932 
3933   if (_log != NULL) {
3934     _log->done("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
3935   }
3936 }
3937 
3938 //=============================================================================
3939 // Two Constant's are equal when the type and the value are equal.
3940 bool Compile::Constant::operator==(const Constant& other) {
3941   if (type()          != other.type()         )  return false;
3942   if (can_be_reused() != other.can_be_reused())  return false;
3943   // For floating point values we compare the bit pattern.
3944   switch (type()) {
3945   case T_INT:
3946   case T_FLOAT:   return (_v._value.i == other._v._value.i);
3947   case T_LONG:
3948   case T_DOUBLE:  return (_v._value.j == other._v._value.j);
3949   case T_OBJECT:
3950   case T_ADDRESS: return (_v._value.l == other._v._value.l);
3951   case T_VOID:    return (_v._value.l == other._v._value.l);  // jump-table entries
3952   case T_METADATA: return (_v._metadata == other._v._metadata);
3953   default: ShouldNotReachHere(); return false;
3954   }
3955 }
3956 
3957 static int type_to_size_in_bytes(BasicType t) {
3958   switch (t) {
3959   case T_INT:     return sizeof(jint   );
3960   case T_LONG:    return sizeof(jlong  );
3961   case T_FLOAT:   return sizeof(jfloat );
3962   case T_DOUBLE:  return sizeof(jdouble);
3963   case T_METADATA: return sizeof(Metadata*);
3964     // We use T_VOID as marker for jump-table entries (labels) which
3965     // need an internal word relocation.
3966   case T_VOID:
3967   case T_ADDRESS:
3968   case T_OBJECT:  return sizeof(jobject);
3969   default:
3970     ShouldNotReachHere();
3971     return -1;
3972   }
3973 }
3974 
3975 int Compile::ConstantTable::qsort_comparator(Constant* a, Constant* b) {
3976   // sort descending
3977   if (a->freq() > b->freq())  return -1;
3978   if (a->freq() < b->freq())  return  1;
3979   return 0;
3980 }
3981 
3982 void Compile::ConstantTable::calculate_offsets_and_size() {
3983   // First, sort the array by frequencies.
3984   _constants.sort(qsort_comparator);
3985 
3986 #ifdef ASSERT
3987   // Make sure all jump-table entries were sorted to the end of the
3988   // array (they have a negative frequency).
3989   bool found_void = false;
3990   for (int i = 0; i < _constants.length(); i++) {
3991     Constant con = _constants.at(i);
3992     if (con.type() == T_VOID)
3993       found_void = true;  // jump-tables
3994     else
3995       assert(!found_void, "wrong sorting");
3996   }
3997 #endif
3998 
3999   int offset = 0;
4000   for (int i = 0; i < _constants.length(); i++) {
4001     Constant* con = _constants.adr_at(i);
4002 
4003     // Align offset for type.
4004     int typesize = type_to_size_in_bytes(con->type());
4005     offset = align_up(offset, typesize);
4006     con->set_offset(offset);   // set constant's offset
4007 
4008     if (con->type() == T_VOID) {
4009       MachConstantNode* n = (MachConstantNode*) con->get_jobject();
4010       offset = offset + typesize * n->outcnt();  // expand jump-table
4011     } else {
4012       offset = offset + typesize;
4013     }
4014   }
4015 
4016   // Align size up to the next section start (which is insts; see
4017   // CodeBuffer::align_at_start).
4018   assert(_size == -1, "already set?");
4019   _size = align_up(offset, (int)CodeEntryAlignment);
4020 }
4021 
4022 void Compile::ConstantTable::emit(CodeBuffer& cb) {
4023   MacroAssembler _masm(&cb);
4024   for (int i = 0; i < _constants.length(); i++) {
4025     Constant con = _constants.at(i);
4026     address constant_addr = NULL;
4027     switch (con.type()) {
4028     case T_INT:    constant_addr = _masm.int_constant(   con.get_jint()   ); break;
4029     case T_LONG:   constant_addr = _masm.long_constant(  con.get_jlong()  ); break;
4030     case T_FLOAT:  constant_addr = _masm.float_constant( con.get_jfloat() ); break;
4031     case T_DOUBLE: constant_addr = _masm.double_constant(con.get_jdouble()); break;
4032     case T_OBJECT: {
4033       jobject obj = con.get_jobject();
4034       int oop_index = _masm.oop_recorder()->find_index(obj);
4035       constant_addr = _masm.address_constant((address) obj, oop_Relocation::spec(oop_index));
4036       break;
4037     }
4038     case T_ADDRESS: {
4039       address addr = (address) con.get_jobject();
4040       constant_addr = _masm.address_constant(addr);
4041       break;
4042     }
4043     // We use T_VOID as marker for jump-table entries (labels) which
4044     // need an internal word relocation.
4045     case T_VOID: {
4046       MachConstantNode* n = (MachConstantNode*) con.get_jobject();
4047       // Fill the jump-table with a dummy word.  The real value is
4048       // filled in later in fill_jump_table.
4049       address dummy = (address) n;
4050       constant_addr = _masm.address_constant(dummy);
4051       // Expand jump-table
4052       for (uint i = 1; i < n->outcnt(); i++) {
4053         address temp_addr = _masm.address_constant(dummy + i);
4054         assert(temp_addr, "consts section too small");
4055       }
4056       break;
4057     }
4058     case T_METADATA: {
4059       Metadata* obj = con.get_metadata();
4060       int metadata_index = _masm.oop_recorder()->find_index(obj);
4061       constant_addr = _masm.address_constant((address) obj, metadata_Relocation::spec(metadata_index));
4062       break;
4063     }
4064     default: ShouldNotReachHere();
4065     }
4066     assert(constant_addr, "consts section too small");
4067     assert((constant_addr - _masm.code()->consts()->start()) == con.offset(),
4068             "must be: %d == %d", (int) (constant_addr - _masm.code()->consts()->start()), (int)(con.offset()));
4069   }
4070 }
4071 
4072 int Compile::ConstantTable::find_offset(Constant& con) const {
4073   int idx = _constants.find(con);
4074   guarantee(idx != -1, "constant must be in constant table");
4075   int offset = _constants.at(idx).offset();
4076   guarantee(offset != -1, "constant table not emitted yet?");
4077   return offset;
4078 }
4079 
4080 void Compile::ConstantTable::add(Constant& con) {
4081   if (con.can_be_reused()) {
4082     int idx = _constants.find(con);
4083     if (idx != -1 && _constants.at(idx).can_be_reused()) {
4084       _constants.adr_at(idx)->inc_freq(con.freq());  // increase the frequency by the current value
4085       return;
4086     }
4087   }
4088   (void) _constants.append(con);
4089 }
4090 
4091 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, BasicType type, jvalue value) {
4092   Block* b = Compile::current()->cfg()->get_block_for_node(n);
4093   Constant con(type, value, b->_freq);
4094   add(con);
4095   return con;
4096 }
4097 
4098 Compile::Constant Compile::ConstantTable::add(Metadata* metadata) {
4099   Constant con(metadata);
4100   add(con);
4101   return con;
4102 }
4103 
4104 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, MachOper* oper) {
4105   jvalue value;
4106   BasicType type = oper->type()->basic_type();
4107   switch (type) {
4108   case T_LONG:    value.j = oper->constantL(); break;
4109   case T_FLOAT:   value.f = oper->constantF(); break;
4110   case T_DOUBLE:  value.d = oper->constantD(); break;
4111   case T_OBJECT:
4112   case T_ADDRESS: value.l = (jobject) oper->constant(); break;
4113   case T_METADATA: return add((Metadata*)oper->constant()); break;
4114   default: guarantee(false, "unhandled type: %s", type2name(type));
4115   }
4116   return add(n, type, value);
4117 }
4118 
4119 Compile::Constant Compile::ConstantTable::add_jump_table(MachConstantNode* n) {
4120   jvalue value;
4121   // We can use the node pointer here to identify the right jump-table
4122   // as this method is called from Compile::Fill_buffer right before
4123   // the MachNodes are emitted and the jump-table is filled (means the
4124   // MachNode pointers do not change anymore).
4125   value.l = (jobject) n;
4126   Constant con(T_VOID, value, next_jump_table_freq(), false);  // Labels of a jump-table cannot be reused.
4127   add(con);
4128   return con;
4129 }
4130 
4131 void Compile::ConstantTable::fill_jump_table(CodeBuffer& cb, MachConstantNode* n, GrowableArray<Label*> labels) const {
4132   // If called from Compile::scratch_emit_size do nothing.
4133   if (Compile::current()->in_scratch_emit_size())  return;
4134 
4135   assert(labels.is_nonempty(), "must be");
4136   assert((uint) labels.length() == n->outcnt(), "must be equal: %d == %d", labels.length(), n->outcnt());
4137 
4138   // Since MachConstantNode::constant_offset() also contains
4139   // table_base_offset() we need to subtract the table_base_offset()
4140   // to get the plain offset into the constant table.
4141   int offset = n->constant_offset() - table_base_offset();
4142 
4143   MacroAssembler _masm(&cb);
4144   address* jump_table_base = (address*) (_masm.code()->consts()->start() + offset);
4145 
4146   for (uint i = 0; i < n->outcnt(); i++) {
4147     address* constant_addr = &jump_table_base[i];
4148     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));
4149     *constant_addr = cb.consts()->target(*labels.at(i), (address) constant_addr);
4150     cb.consts()->relocate((address) constant_addr, relocInfo::internal_word_type);
4151   }
4152 }
4153 
4154 //----------------------------static_subtype_check-----------------------------
4155 // Shortcut important common cases when superklass is exact:
4156 // (0) superklass is java.lang.Object (can occur in reflective code)
4157 // (1) subklass is already limited to a subtype of superklass => always ok
4158 // (2) subklass does not overlap with superklass => always fail
4159 // (3) superklass has NO subtypes and we can check with a simple compare.
4160 int Compile::static_subtype_check(ciKlass* superk, ciKlass* subk) {
4161   if (StressReflectiveCode) {
4162     return SSC_full_test;       // Let caller generate the general case.
4163   }
4164 
4165   if (superk == env()->Object_klass()) {
4166     return SSC_always_true;     // (0) this test cannot fail
4167   }
4168 
4169   ciType* superelem = superk;
4170   if (superelem->is_array_klass())
4171     superelem = superelem->as_array_klass()->base_element_type();
4172 
4173   if (!subk->is_interface()) {  // cannot trust static interface types yet
4174     if (subk->is_subtype_of(superk)) {
4175       return SSC_always_true;   // (1) false path dead; no dynamic test needed
4176     }
4177     if (!(superelem->is_klass() && superelem->as_klass()->is_interface()) &&
4178         !superk->is_subtype_of(subk)) {
4179       return SSC_always_false;
4180     }
4181   }
4182 
4183   // If casting to an instance klass, it must have no subtypes
4184   if (superk->is_interface()) {
4185     // Cannot trust interfaces yet.
4186     // %%% S.B. superk->nof_implementors() == 1
4187   } else if (superelem->is_instance_klass()) {
4188     ciInstanceKlass* ik = superelem->as_instance_klass();
4189     if (!ik->has_subklass() && !ik->is_interface()) {
4190       if (!ik->is_final()) {
4191         // Add a dependency if there is a chance of a later subclass.
4192         dependencies()->assert_leaf_type(ik);
4193       }
4194       return SSC_easy_test;     // (3) caller can do a simple ptr comparison
4195     }
4196   } else {
4197     // A primitive array type has no subtypes.
4198     return SSC_easy_test;       // (3) caller can do a simple ptr comparison
4199   }
4200 
4201   return SSC_full_test;
4202 }
4203 
4204 Node* Compile::conv_I2X_index(PhaseGVN* phase, Node* idx, const TypeInt* sizetype, Node* ctrl) {
4205 #ifdef _LP64
4206   // The scaled index operand to AddP must be a clean 64-bit value.
4207   // Java allows a 32-bit int to be incremented to a negative
4208   // value, which appears in a 64-bit register as a large
4209   // positive number.  Using that large positive number as an
4210   // operand in pointer arithmetic has bad consequences.
4211   // On the other hand, 32-bit overflow is rare, and the possibility
4212   // can often be excluded, if we annotate the ConvI2L node with
4213   // a type assertion that its value is known to be a small positive
4214   // number.  (The prior range check has ensured this.)
4215   // This assertion is used by ConvI2LNode::Ideal.
4216   int index_max = max_jint - 1;  // array size is max_jint, index is one less
4217   if (sizetype != NULL) index_max = sizetype->_hi - 1;
4218   const TypeInt* iidxtype = TypeInt::make(0, index_max, Type::WidenMax);
4219   idx = constrained_convI2L(phase, idx, iidxtype, ctrl);
4220 #endif
4221   return idx;
4222 }
4223 
4224 // Convert integer value to a narrowed long type dependent on ctrl (for example, a range check)
4225 Node* Compile::constrained_convI2L(PhaseGVN* phase, Node* value, const TypeInt* itype, Node* ctrl) {
4226   if (ctrl != NULL) {
4227     // Express control dependency by a CastII node with a narrow type.
4228     value = new CastIINode(value, itype, false, true /* range check dependency */);
4229     // Make the CastII node dependent on the control input to prevent the narrowed ConvI2L
4230     // node from floating above the range check during loop optimizations. Otherwise, the
4231     // ConvI2L node may be eliminated independently of the range check, causing the data path
4232     // to become TOP while the control path is still there (although it's unreachable).
4233     value->set_req(0, ctrl);
4234     // Save CastII node to remove it after loop optimizations.
4235     phase->C->add_range_check_cast(value);
4236     value = phase->transform(value);
4237   }
4238   const TypeLong* ltype = TypeLong::make(itype->_lo, itype->_hi, itype->_widen);
4239   return phase->transform(new ConvI2LNode(value, ltype));
4240 }
4241 
4242 // The message about the current inlining is accumulated in
4243 // _print_inlining_stream and transfered into the _print_inlining_list
4244 // once we know whether inlining succeeds or not. For regular
4245 // inlining, messages are appended to the buffer pointed by
4246 // _print_inlining_idx in the _print_inlining_list. For late inlining,
4247 // a new buffer is added after _print_inlining_idx in the list. This
4248 // way we can update the inlining message for late inlining call site
4249 // when the inlining is attempted again.
4250 void Compile::print_inlining_init() {
4251   if (print_inlining() || print_intrinsics()) {
4252     _print_inlining_stream = new stringStream();
4253     _print_inlining_list = new (comp_arena())GrowableArray<PrintInliningBuffer>(comp_arena(), 1, 1, PrintInliningBuffer());
4254   }
4255 }
4256 
4257 void Compile::print_inlining_reinit() {
4258   if (print_inlining() || print_intrinsics()) {
4259     // Re allocate buffer when we change ResourceMark
4260     _print_inlining_stream = new stringStream();
4261   }
4262 }
4263 
4264 void Compile::print_inlining_reset() {
4265   _print_inlining_stream->reset();
4266 }
4267 
4268 void Compile::print_inlining_commit() {
4269   assert(print_inlining() || print_intrinsics(), "PrintInlining off?");
4270   // Transfer the message from _print_inlining_stream to the current
4271   // _print_inlining_list buffer and clear _print_inlining_stream.
4272   _print_inlining_list->at(_print_inlining_idx).ss()->write(_print_inlining_stream->as_string(), _print_inlining_stream->size());
4273   print_inlining_reset();
4274 }
4275 
4276 void Compile::print_inlining_push() {
4277   // Add new buffer to the _print_inlining_list at current position
4278   _print_inlining_idx++;
4279   _print_inlining_list->insert_before(_print_inlining_idx, PrintInliningBuffer());
4280 }
4281 
4282 Compile::PrintInliningBuffer& Compile::print_inlining_current() {
4283   return _print_inlining_list->at(_print_inlining_idx);
4284 }
4285 
4286 void Compile::print_inlining_update(CallGenerator* cg) {
4287   if (print_inlining() || print_intrinsics()) {
4288     if (!cg->is_late_inline()) {
4289       if (print_inlining_current().cg() != NULL) {
4290         print_inlining_push();
4291       }
4292       print_inlining_commit();
4293     } else {
4294       if (print_inlining_current().cg() != cg &&
4295           (print_inlining_current().cg() != NULL ||
4296            print_inlining_current().ss()->size() != 0)) {
4297         print_inlining_push();
4298       }
4299       print_inlining_commit();
4300       print_inlining_current().set_cg(cg);
4301     }
4302   }
4303 }
4304 
4305 void Compile::print_inlining_move_to(CallGenerator* cg) {
4306   // We resume inlining at a late inlining call site. Locate the
4307   // corresponding inlining buffer so that we can update it.
4308   if (print_inlining()) {
4309     for (int i = 0; i < _print_inlining_list->length(); i++) {
4310       if (_print_inlining_list->adr_at(i)->cg() == cg) {
4311         _print_inlining_idx = i;
4312         return;
4313       }
4314     }
4315     ShouldNotReachHere();
4316   }
4317 }
4318 
4319 void Compile::print_inlining_update_delayed(CallGenerator* cg) {
4320   if (print_inlining()) {
4321     assert(_print_inlining_stream->size() > 0, "missing inlining msg");
4322     assert(print_inlining_current().cg() == cg, "wrong entry");
4323     // replace message with new message
4324     _print_inlining_list->at_put(_print_inlining_idx, PrintInliningBuffer());
4325     print_inlining_commit();
4326     print_inlining_current().set_cg(cg);
4327   }
4328 }
4329 
4330 void Compile::print_inlining_assert_ready() {
4331   assert(!_print_inlining || _print_inlining_stream->size() == 0, "loosing data");
4332 }
4333 
4334 void Compile::process_print_inlining() {
4335   bool do_print_inlining = print_inlining() || print_intrinsics();
4336   if (do_print_inlining || log() != NULL) {
4337     // Print inlining message for candidates that we couldn't inline
4338     // for lack of space
4339     for (int i = 0; i < _late_inlines.length(); i++) {
4340       CallGenerator* cg = _late_inlines.at(i);
4341       if (!cg->is_mh_late_inline()) {
4342         const char* msg = "live nodes > LiveNodeCountInliningCutoff";
4343         if (do_print_inlining) {
4344           cg->print_inlining_late(msg);
4345         }
4346         log_late_inline_failure(cg, msg);
4347       }
4348     }
4349   }
4350   if (do_print_inlining) {
4351     ResourceMark rm;
4352     stringStream ss;
4353     for (int i = 0; i < _print_inlining_list->length(); i++) {
4354       ss.print("%s", _print_inlining_list->adr_at(i)->ss()->as_string());
4355     }
4356     size_t end = ss.size();
4357     _print_inlining_output = NEW_ARENA_ARRAY(comp_arena(), char, end+1);
4358     strncpy(_print_inlining_output, ss.base(), end+1);
4359     _print_inlining_output[end] = 0;
4360   }
4361 }
4362 
4363 void Compile::dump_print_inlining() {
4364   if (_print_inlining_output != NULL) {
4365     tty->print_raw(_print_inlining_output);
4366   }
4367 }
4368 
4369 void Compile::log_late_inline(CallGenerator* cg) {
4370   if (log() != NULL) {
4371     log()->head("late_inline method='%d'  inline_id='" JLONG_FORMAT "'", log()->identify(cg->method()),
4372                 cg->unique_id());
4373     JVMState* p = cg->call_node()->jvms();
4374     while (p != NULL) {
4375       log()->elem("jvms bci='%d' method='%d'", p->bci(), log()->identify(p->method()));
4376       p = p->caller();
4377     }
4378     log()->tail("late_inline");
4379   }
4380 }
4381 
4382 void Compile::log_late_inline_failure(CallGenerator* cg, const char* msg) {
4383   log_late_inline(cg);
4384   if (log() != NULL) {
4385     log()->inline_fail(msg);
4386   }
4387 }
4388 
4389 void Compile::log_inline_id(CallGenerator* cg) {
4390   if (log() != NULL) {
4391     // The LogCompilation tool needs a unique way to identify late
4392     // inline call sites. This id must be unique for this call site in
4393     // this compilation. Try to have it unique across compilations as
4394     // well because it can be convenient when grepping through the log
4395     // file.
4396     // Distinguish OSR compilations from others in case CICountOSR is
4397     // on.
4398     jlong id = ((jlong)unique()) + (((jlong)compile_id()) << 33) + (CICountOSR && is_osr_compilation() ? ((jlong)1) << 32 : 0);
4399     cg->set_unique_id(id);
4400     log()->elem("inline_id id='" JLONG_FORMAT "'", id);
4401   }
4402 }
4403 
4404 void Compile::log_inline_failure(const char* msg) {
4405   if (C->log() != NULL) {
4406     C->log()->inline_fail(msg);
4407   }
4408 }
4409 
4410 
4411 // Dump inlining replay data to the stream.
4412 // Don't change thread state and acquire any locks.
4413 void Compile::dump_inline_data(outputStream* out) {
4414   InlineTree* inl_tree = ilt();
4415   if (inl_tree != NULL) {
4416     out->print(" inline %d", inl_tree->count());
4417     inl_tree->dump_replay_data(out);
4418   }
4419 }
4420 
4421 int Compile::cmp_expensive_nodes(Node* n1, Node* n2) {
4422   if (n1->Opcode() < n2->Opcode())      return -1;
4423   else if (n1->Opcode() > n2->Opcode()) return 1;
4424 
4425   assert(n1->req() == n2->req(), "can't compare %s nodes: n1->req() = %d, n2->req() = %d", NodeClassNames[n1->Opcode()], n1->req(), n2->req());
4426   for (uint i = 1; i < n1->req(); i++) {
4427     if (n1->in(i) < n2->in(i))      return -1;
4428     else if (n1->in(i) > n2->in(i)) return 1;
4429   }
4430 
4431   return 0;
4432 }
4433 
4434 int Compile::cmp_expensive_nodes(Node** n1p, Node** n2p) {
4435   Node* n1 = *n1p;
4436   Node* n2 = *n2p;
4437 
4438   return cmp_expensive_nodes(n1, n2);
4439 }
4440 
4441 void Compile::sort_expensive_nodes() {
4442   if (!expensive_nodes_sorted()) {
4443     _expensive_nodes->sort(cmp_expensive_nodes);
4444   }
4445 }
4446 
4447 bool Compile::expensive_nodes_sorted() const {
4448   for (int i = 1; i < _expensive_nodes->length(); i++) {
4449     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i-1)) < 0) {
4450       return false;
4451     }
4452   }
4453   return true;
4454 }
4455 
4456 bool Compile::should_optimize_expensive_nodes(PhaseIterGVN &igvn) {
4457   if (_expensive_nodes->length() == 0) {
4458     return false;
4459   }
4460 
4461   assert(OptimizeExpensiveOps, "optimization off?");
4462 
4463   // Take this opportunity to remove dead nodes from the list
4464   int j = 0;
4465   for (int i = 0; i < _expensive_nodes->length(); i++) {
4466     Node* n = _expensive_nodes->at(i);
4467     if (!n->is_unreachable(igvn)) {
4468       assert(n->is_expensive(), "should be expensive");
4469       _expensive_nodes->at_put(j, n);
4470       j++;
4471     }
4472   }
4473   _expensive_nodes->trunc_to(j);
4474 
4475   // Then sort the list so that similar nodes are next to each other
4476   // and check for at least two nodes of identical kind with same data
4477   // inputs.
4478   sort_expensive_nodes();
4479 
4480   for (int i = 0; i < _expensive_nodes->length()-1; i++) {
4481     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i+1)) == 0) {
4482       return true;
4483     }
4484   }
4485 
4486   return false;
4487 }
4488 
4489 void Compile::cleanup_expensive_nodes(PhaseIterGVN &igvn) {
4490   if (_expensive_nodes->length() == 0) {
4491     return;
4492   }
4493 
4494   assert(OptimizeExpensiveOps, "optimization off?");
4495 
4496   // Sort to bring similar nodes next to each other and clear the
4497   // control input of nodes for which there's only a single copy.
4498   sort_expensive_nodes();
4499 
4500   int j = 0;
4501   int identical = 0;
4502   int i = 0;
4503   bool modified = false;
4504   for (; i < _expensive_nodes->length()-1; i++) {
4505     assert(j <= i, "can't write beyond current index");
4506     if (_expensive_nodes->at(i)->Opcode() == _expensive_nodes->at(i+1)->Opcode()) {
4507       identical++;
4508       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4509       continue;
4510     }
4511     if (identical > 0) {
4512       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4513       identical = 0;
4514     } else {
4515       Node* n = _expensive_nodes->at(i);
4516       igvn.replace_input_of(n, 0, NULL);
4517       igvn.hash_insert(n);
4518       modified = true;
4519     }
4520   }
4521   if (identical > 0) {
4522     _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4523   } else if (_expensive_nodes->length() >= 1) {
4524     Node* n = _expensive_nodes->at(i);
4525     igvn.replace_input_of(n, 0, NULL);
4526     igvn.hash_insert(n);
4527     modified = true;
4528   }
4529   _expensive_nodes->trunc_to(j);
4530   if (modified) {
4531     igvn.optimize();
4532   }
4533 }
4534 
4535 void Compile::add_expensive_node(Node * n) {
4536   assert(!_expensive_nodes->contains(n), "duplicate entry in expensive list");
4537   assert(n->is_expensive(), "expensive nodes with non-null control here only");
4538   assert(!n->is_CFG() && !n->is_Mem(), "no cfg or memory nodes here");
4539   if (OptimizeExpensiveOps) {
4540     _expensive_nodes->append(n);
4541   } else {
4542     // Clear control input and let IGVN optimize expensive nodes if
4543     // OptimizeExpensiveOps is off.
4544     n->set_req(0, NULL);
4545   }
4546 }
4547 
4548 /**
4549  * Remove the speculative part of types and clean up the graph
4550  */
4551 void Compile::remove_speculative_types(PhaseIterGVN &igvn) {
4552   if (UseTypeSpeculation) {
4553     Unique_Node_List worklist;
4554     worklist.push(root());
4555     int modified = 0;
4556     // Go over all type nodes that carry a speculative type, drop the
4557     // speculative part of the type and enqueue the node for an igvn
4558     // which may optimize it out.
4559     for (uint next = 0; next < worklist.size(); ++next) {
4560       Node *n  = worklist.at(next);
4561       if (n->is_Type()) {
4562         TypeNode* tn = n->as_Type();
4563         const Type* t = tn->type();
4564         const Type* t_no_spec = t->remove_speculative();
4565         if (t_no_spec != t) {
4566           bool in_hash = igvn.hash_delete(n);
4567           assert(in_hash, "node should be in igvn hash table");
4568           tn->set_type(t_no_spec);
4569           igvn.hash_insert(n);
4570           igvn._worklist.push(n); // give it a chance to go away
4571           modified++;
4572         }
4573       }
4574       uint max = n->len();
4575       for( uint i = 0; i < max; ++i ) {
4576         Node *m = n->in(i);
4577         if (not_a_node(m))  continue;
4578         worklist.push(m);
4579       }
4580     }
4581     // Drop the speculative part of all types in the igvn's type table
4582     igvn.remove_speculative_types();
4583     if (modified > 0) {
4584       igvn.optimize();
4585     }
4586 #ifdef ASSERT
4587     // Verify that after the IGVN is over no speculative type has resurfaced
4588     worklist.clear();
4589     worklist.push(root());
4590     for (uint next = 0; next < worklist.size(); ++next) {
4591       Node *n  = worklist.at(next);
4592       const Type* t = igvn.type_or_null(n);
4593       assert((t == NULL) || (t == t->remove_speculative()), "no more speculative types");
4594       if (n->is_Type()) {
4595         t = n->as_Type()->type();
4596         assert(t == t->remove_speculative(), "no more speculative types");
4597       }
4598       uint max = n->len();
4599       for( uint i = 0; i < max; ++i ) {
4600         Node *m = n->in(i);
4601         if (not_a_node(m))  continue;
4602         worklist.push(m);
4603       }
4604     }
4605     igvn.check_no_speculative_types();
4606 #endif
4607   }
4608 }
4609 
4610 // Auxiliary method to support randomized stressing/fuzzing.
4611 //
4612 // This method can be called the arbitrary number of times, with current count
4613 // as the argument. The logic allows selecting a single candidate from the
4614 // running list of candidates as follows:
4615 //    int count = 0;
4616 //    Cand* selected = null;
4617 //    while(cand = cand->next()) {
4618 //      if (randomized_select(++count)) {
4619 //        selected = cand;
4620 //      }
4621 //    }
4622 //
4623 // Including count equalizes the chances any candidate is "selected".
4624 // This is useful when we don't have the complete list of candidates to choose
4625 // from uniformly. In this case, we need to adjust the randomicity of the
4626 // selection, or else we will end up biasing the selection towards the latter
4627 // candidates.
4628 //
4629 // Quick back-envelope calculation shows that for the list of n candidates
4630 // the equal probability for the candidate to persist as "best" can be
4631 // achieved by replacing it with "next" k-th candidate with the probability
4632 // of 1/k. It can be easily shown that by the end of the run, the
4633 // probability for any candidate is converged to 1/n, thus giving the
4634 // uniform distribution among all the candidates.
4635 //
4636 // We don't care about the domain size as long as (RANDOMIZED_DOMAIN / count) is large.
4637 #define RANDOMIZED_DOMAIN_POW 29
4638 #define RANDOMIZED_DOMAIN (1 << RANDOMIZED_DOMAIN_POW)
4639 #define RANDOMIZED_DOMAIN_MASK ((1 << (RANDOMIZED_DOMAIN_POW + 1)) - 1)
4640 bool Compile::randomized_select(int count) {
4641   assert(count > 0, "only positive");
4642   return (os::random() & RANDOMIZED_DOMAIN_MASK) < (RANDOMIZED_DOMAIN / count);
4643 }
4644 
4645 CloneMap&     Compile::clone_map()                 { return _clone_map; }
4646 void          Compile::set_clone_map(Dict* d)      { _clone_map._dict = d; }
4647 
4648 void NodeCloneInfo::dump() const {
4649   tty->print(" {%d:%d} ", idx(), gen());
4650 }
4651 
4652 void CloneMap::clone(Node* old, Node* nnn, int gen) {
4653   uint64_t val = value(old->_idx);
4654   NodeCloneInfo cio(val);
4655   assert(val != 0, "old node should be in the map");
4656   NodeCloneInfo cin(cio.idx(), gen + cio.gen());
4657   insert(nnn->_idx, cin.get());
4658 #ifndef PRODUCT
4659   if (is_debug()) {
4660     tty->print_cr("CloneMap::clone inserted node %d info {%d:%d} into CloneMap", nnn->_idx, cin.idx(), cin.gen());
4661   }
4662 #endif
4663 }
4664 
4665 void CloneMap::verify_insert_and_clone(Node* old, Node* nnn, int gen) {
4666   NodeCloneInfo cio(value(old->_idx));
4667   if (cio.get() == 0) {
4668     cio.set(old->_idx, 0);
4669     insert(old->_idx, cio.get());
4670 #ifndef PRODUCT
4671     if (is_debug()) {
4672       tty->print_cr("CloneMap::verify_insert_and_clone inserted node %d info {%d:%d} into CloneMap", old->_idx, cio.idx(), cio.gen());
4673     }
4674 #endif
4675   }
4676   clone(old, nnn, gen);
4677 }
4678 
4679 int CloneMap::max_gen() const {
4680   int g = 0;
4681   DictI di(_dict);
4682   for(; di.test(); ++di) {
4683     int t = gen(di._key);
4684     if (g < t) {
4685       g = t;
4686 #ifndef PRODUCT
4687       if (is_debug()) {
4688         tty->print_cr("CloneMap::max_gen() update max=%d from %d", g, _2_node_idx_t(di._key));
4689       }
4690 #endif
4691     }
4692   }
4693   return g;
4694 }
4695 
4696 void CloneMap::dump(node_idx_t key) const {
4697   uint64_t val = value(key);
4698   if (val != 0) {
4699     NodeCloneInfo ni(val);
4700     ni.dump();
4701   }
4702 }
--- EOF ---