1 /*
   2  * Copyright (c) 1997, 2016, 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 "memory/resourceArea.hpp"
  37 #include "opto/addnode.hpp"
  38 #include "opto/block.hpp"
  39 #include "opto/c2compiler.hpp"
  40 #include "opto/callGenerator.hpp"
  41 #include "opto/callnode.hpp"
  42 #include "opto/castnode.hpp"
  43 #include "opto/cfgnode.hpp"
  44 #include "opto/chaitin.hpp"
  45 #include "opto/compile.hpp"
  46 #include "opto/connode.hpp"
  47 #include "opto/convertnode.hpp"
  48 #include "opto/divnode.hpp"
  49 #include "opto/escape.hpp"
  50 #include "opto/idealGraphPrinter.hpp"
  51 #include "opto/loopnode.hpp"
  52 #include "opto/machnode.hpp"
  53 #include "opto/macro.hpp"
  54 #include "opto/matcher.hpp"
  55 #include "opto/mathexactnode.hpp"
  56 #include "opto/memnode.hpp"
  57 #include "opto/mulnode.hpp"
  58 #include "opto/narrowptrnode.hpp"
  59 #include "opto/node.hpp"
  60 #include "opto/opcodes.hpp"
  61 #include "opto/output.hpp"
  62 #include "opto/parse.hpp"
  63 #include "opto/phaseX.hpp"
  64 #include "opto/rootnode.hpp"
  65 #include "opto/runtime.hpp"
  66 #include "opto/stringopts.hpp"
  67 #include "opto/type.hpp"
  68 #include "opto/valuetypenode.hpp"
  69 #include "opto/vectornode.hpp"
  70 #include "runtime/arguments.hpp"
  71 #include "runtime/sharedRuntime.hpp"
  72 #include "runtime/signature.hpp"
  73 #include "runtime/stubRoutines.hpp"
  74 #include "runtime/timer.hpp"
  75 #include "utilities/copy.hpp"
  76 
  77 
  78 // -------------------- Compile::mach_constant_base_node -----------------------
  79 // Constant table base node singleton.
  80 MachConstantBaseNode* Compile::mach_constant_base_node() {
  81   if (_mach_constant_base_node == NULL) {
  82     _mach_constant_base_node = new MachConstantBaseNode();
  83     _mach_constant_base_node->add_req(C->root());
  84   }
  85   return _mach_constant_base_node;
  86 }
  87 
  88 
  89 /// Support for intrinsics.
  90 
  91 // Return the index at which m must be inserted (or already exists).
  92 // The sort order is by the address of the ciMethod, with is_virtual as minor key.
  93 class IntrinsicDescPair {
  94  private:
  95   ciMethod* _m;
  96   bool _is_virtual;
  97  public:
  98   IntrinsicDescPair(ciMethod* m, bool is_virtual) : _m(m), _is_virtual(is_virtual) {}
  99   static int compare(IntrinsicDescPair* const& key, CallGenerator* const& elt) {
 100     ciMethod* m= elt->method();
 101     ciMethod* key_m = key->_m;
 102     if (key_m < m)      return -1;
 103     else if (key_m > m) return 1;
 104     else {
 105       bool is_virtual = elt->is_virtual();
 106       bool key_virtual = key->_is_virtual;
 107       if (key_virtual < is_virtual)      return -1;
 108       else if (key_virtual > is_virtual) return 1;
 109       else                               return 0;
 110     }
 111   }
 112 };
 113 int Compile::intrinsic_insertion_index(ciMethod* m, bool is_virtual, bool& found) {
 114 #ifdef ASSERT
 115   for (int i = 1; i < _intrinsics->length(); i++) {
 116     CallGenerator* cg1 = _intrinsics->at(i-1);
 117     CallGenerator* cg2 = _intrinsics->at(i);
 118     assert(cg1->method() != cg2->method()
 119            ? cg1->method()     < cg2->method()
 120            : cg1->is_virtual() < cg2->is_virtual(),
 121            "compiler intrinsics list must stay sorted");
 122   }
 123 #endif
 124   IntrinsicDescPair pair(m, is_virtual);
 125   return _intrinsics->find_sorted<IntrinsicDescPair*, IntrinsicDescPair::compare>(&pair, found);
 126 }
 127 
 128 void Compile::register_intrinsic(CallGenerator* cg) {
 129   if (_intrinsics == NULL) {
 130     _intrinsics = new (comp_arena())GrowableArray<CallGenerator*>(comp_arena(), 60, 0, NULL);
 131   }
 132   int len = _intrinsics->length();
 133   bool found = false;
 134   int index = intrinsic_insertion_index(cg->method(), cg->is_virtual(), found);
 135   assert(!found, "registering twice");
 136   _intrinsics->insert_before(index, cg);
 137   assert(find_intrinsic(cg->method(), cg->is_virtual()) == cg, "registration worked");
 138 }
 139 
 140 CallGenerator* Compile::find_intrinsic(ciMethod* m, bool is_virtual) {
 141   assert(m->is_loaded(), "don't try this on unloaded methods");
 142   if (_intrinsics != NULL) {
 143     bool found = false;
 144     int index = intrinsic_insertion_index(m, is_virtual, found);
 145      if (found) {
 146       return _intrinsics->at(index);
 147     }
 148   }
 149   // Lazily create intrinsics for intrinsic IDs well-known in the runtime.
 150   if (m->intrinsic_id() != vmIntrinsics::_none &&
 151       m->intrinsic_id() <= vmIntrinsics::LAST_COMPILER_INLINE) {
 152     CallGenerator* cg = make_vm_intrinsic(m, is_virtual);
 153     if (cg != NULL) {
 154       // Save it for next time:
 155       register_intrinsic(cg);
 156       return cg;
 157     } else {
 158       gather_intrinsic_statistics(m->intrinsic_id(), is_virtual, _intrinsic_disabled);
 159     }
 160   }
 161   return NULL;
 162 }
 163 
 164 // Compile:: register_library_intrinsics and make_vm_intrinsic are defined
 165 // in library_call.cpp.
 166 
 167 
 168 #ifndef PRODUCT
 169 // statistics gathering...
 170 
 171 juint  Compile::_intrinsic_hist_count[vmIntrinsics::ID_LIMIT] = {0};
 172 jubyte Compile::_intrinsic_hist_flags[vmIntrinsics::ID_LIMIT] = {0};
 173 
 174 bool Compile::gather_intrinsic_statistics(vmIntrinsics::ID id, bool is_virtual, int flags) {
 175   assert(id > vmIntrinsics::_none && id < vmIntrinsics::ID_LIMIT, "oob");
 176   int oflags = _intrinsic_hist_flags[id];
 177   assert(flags != 0, "what happened?");
 178   if (is_virtual) {
 179     flags |= _intrinsic_virtual;
 180   }
 181   bool changed = (flags != oflags);
 182   if ((flags & _intrinsic_worked) != 0) {
 183     juint count = (_intrinsic_hist_count[id] += 1);
 184     if (count == 1) {
 185       changed = true;           // first time
 186     }
 187     // increment the overall count also:
 188     _intrinsic_hist_count[vmIntrinsics::_none] += 1;
 189   }
 190   if (changed) {
 191     if (((oflags ^ flags) & _intrinsic_virtual) != 0) {
 192       // Something changed about the intrinsic's virtuality.
 193       if ((flags & _intrinsic_virtual) != 0) {
 194         // This is the first use of this intrinsic as a virtual call.
 195         if (oflags != 0) {
 196           // We already saw it as a non-virtual, so note both cases.
 197           flags |= _intrinsic_both;
 198         }
 199       } else if ((oflags & _intrinsic_both) == 0) {
 200         // This is the first use of this intrinsic as a non-virtual
 201         flags |= _intrinsic_both;
 202       }
 203     }
 204     _intrinsic_hist_flags[id] = (jubyte) (oflags | flags);
 205   }
 206   // update the overall flags also:
 207   _intrinsic_hist_flags[vmIntrinsics::_none] |= (jubyte) flags;
 208   return changed;
 209 }
 210 
 211 static char* format_flags(int flags, char* buf) {
 212   buf[0] = 0;
 213   if ((flags & Compile::_intrinsic_worked) != 0)    strcat(buf, ",worked");
 214   if ((flags & Compile::_intrinsic_failed) != 0)    strcat(buf, ",failed");
 215   if ((flags & Compile::_intrinsic_disabled) != 0)  strcat(buf, ",disabled");
 216   if ((flags & Compile::_intrinsic_virtual) != 0)   strcat(buf, ",virtual");
 217   if ((flags & Compile::_intrinsic_both) != 0)      strcat(buf, ",nonvirtual");
 218   if (buf[0] == 0)  strcat(buf, ",");
 219   assert(buf[0] == ',', "must be");
 220   return &buf[1];
 221 }
 222 
 223 void Compile::print_intrinsic_statistics() {
 224   char flagsbuf[100];
 225   ttyLocker ttyl;
 226   if (xtty != NULL)  xtty->head("statistics type='intrinsic'");
 227   tty->print_cr("Compiler intrinsic usage:");
 228   juint total = _intrinsic_hist_count[vmIntrinsics::_none];
 229   if (total == 0)  total = 1;  // avoid div0 in case of no successes
 230   #define PRINT_STAT_LINE(name, c, f) \
 231     tty->print_cr("  %4d (%4.1f%%) %s (%s)", (int)(c), ((c) * 100.0) / total, name, f);
 232   for (int index = 1 + (int)vmIntrinsics::_none; index < (int)vmIntrinsics::ID_LIMIT; index++) {
 233     vmIntrinsics::ID id = (vmIntrinsics::ID) index;
 234     int   flags = _intrinsic_hist_flags[id];
 235     juint count = _intrinsic_hist_count[id];
 236     if ((flags | count) != 0) {
 237       PRINT_STAT_LINE(vmIntrinsics::name_at(id), count, format_flags(flags, flagsbuf));
 238     }
 239   }
 240   PRINT_STAT_LINE("total", total, format_flags(_intrinsic_hist_flags[vmIntrinsics::_none], flagsbuf));
 241   if (xtty != NULL)  xtty->tail("statistics");
 242 }
 243 
 244 void Compile::print_statistics() {
 245   { ttyLocker ttyl;
 246     if (xtty != NULL)  xtty->head("statistics type='opto'");
 247     Parse::print_statistics();
 248     PhaseCCP::print_statistics();
 249     PhaseRegAlloc::print_statistics();
 250     Scheduling::print_statistics();
 251     PhasePeephole::print_statistics();
 252     PhaseIdealLoop::print_statistics();
 253     if (xtty != NULL)  xtty->tail("statistics");
 254   }
 255   if (_intrinsic_hist_flags[vmIntrinsics::_none] != 0) {
 256     // put this under its own <statistics> element.
 257     print_intrinsic_statistics();
 258   }
 259 }
 260 #endif //PRODUCT
 261 
 262 // Support for bundling info
 263 Bundle* Compile::node_bundling(const Node *n) {
 264   assert(valid_bundle_info(n), "oob");
 265   return &_node_bundling_base[n->_idx];
 266 }
 267 
 268 bool Compile::valid_bundle_info(const Node *n) {
 269   return (_node_bundling_limit > n->_idx);
 270 }
 271 
 272 
 273 void Compile::gvn_replace_by(Node* n, Node* nn) {
 274   for (DUIterator_Last imin, i = n->last_outs(imin); i >= imin; ) {
 275     Node* use = n->last_out(i);
 276     bool is_in_table = initial_gvn()->hash_delete(use);
 277     uint uses_found = 0;
 278     for (uint j = 0; j < use->len(); j++) {
 279       if (use->in(j) == n) {
 280         if (j < use->req())
 281           use->set_req(j, nn);
 282         else
 283           use->set_prec(j, nn);
 284         uses_found++;
 285       }
 286     }
 287     if (is_in_table) {
 288       // reinsert into table
 289       initial_gvn()->hash_find_insert(use);
 290     }
 291     record_for_igvn(use);
 292     i -= uses_found;    // we deleted 1 or more copies of this edge
 293   }
 294 }
 295 
 296 
 297 static inline bool not_a_node(const Node* n) {
 298   if (n == NULL)                   return true;
 299   if (((intptr_t)n & 1) != 0)      return true;  // uninitialized, etc.
 300   if (*(address*)n == badAddress)  return true;  // kill by Node::destruct
 301   return false;
 302 }
 303 
 304 // Identify all nodes that are reachable from below, useful.
 305 // Use breadth-first pass that records state in a Unique_Node_List,
 306 // recursive traversal is slower.
 307 void Compile::identify_useful_nodes(Unique_Node_List &useful) {
 308   int estimated_worklist_size = live_nodes();
 309   useful.map( estimated_worklist_size, NULL );  // preallocate space
 310 
 311   // Initialize worklist
 312   if (root() != NULL)     { useful.push(root()); }
 313   // If 'top' is cached, declare it useful to preserve cached node
 314   if( cached_top_node() ) { useful.push(cached_top_node()); }
 315 
 316   // Push all useful nodes onto the list, breadthfirst
 317   for( uint next = 0; next < useful.size(); ++next ) {
 318     assert( next < unique(), "Unique useful nodes < total nodes");
 319     Node *n  = useful.at(next);
 320     uint max = n->len();
 321     for( uint i = 0; i < max; ++i ) {
 322       Node *m = n->in(i);
 323       if (not_a_node(m))  continue;
 324       useful.push(m);
 325     }
 326   }
 327 }
 328 
 329 // Update dead_node_list with any missing dead nodes using useful
 330 // list. Consider all non-useful nodes to be useless i.e., dead nodes.
 331 void Compile::update_dead_node_list(Unique_Node_List &useful) {
 332   uint max_idx = unique();
 333   VectorSet& useful_node_set = useful.member_set();
 334 
 335   for (uint node_idx = 0; node_idx < max_idx; node_idx++) {
 336     // If node with index node_idx is not in useful set,
 337     // mark it as dead in dead node list.
 338     if (! useful_node_set.test(node_idx) ) {
 339       record_dead_node(node_idx);
 340     }
 341   }
 342 }
 343 
 344 void Compile::remove_useless_late_inlines(GrowableArray<CallGenerator*>* inlines, Unique_Node_List &useful) {
 345   int shift = 0;
 346   for (int i = 0; i < inlines->length(); i++) {
 347     CallGenerator* cg = inlines->at(i);
 348     CallNode* call = cg->call_node();
 349     if (shift > 0) {
 350       inlines->at_put(i-shift, cg);
 351     }
 352     if (!useful.member(call)) {
 353       shift++;
 354     }
 355   }
 356   inlines->trunc_to(inlines->length()-shift);
 357 }
 358 
 359 // Disconnect all useless nodes by disconnecting those at the boundary.
 360 void Compile::remove_useless_nodes(Unique_Node_List &useful) {
 361   uint next = 0;
 362   while (next < useful.size()) {
 363     Node *n = useful.at(next++);
 364     if (n->is_SafePoint()) {
 365       // We're done with a parsing phase. Replaced nodes are not valid
 366       // beyond that point.
 367       n->as_SafePoint()->delete_replaced_nodes();
 368     }
 369     // Use raw traversal of out edges since this code removes out edges
 370     int max = n->outcnt();
 371     for (int j = 0; j < max; ++j) {
 372       Node* child = n->raw_out(j);
 373       if (! useful.member(child)) {
 374         assert(!child->is_top() || child != top(),
 375                "If top is cached in Compile object it is in useful list");
 376         // Only need to remove this out-edge to the useless node
 377         n->raw_del_out(j);
 378         --j;
 379         --max;
 380       }
 381     }
 382     if (n->outcnt() == 1 && n->has_special_unique_user()) {
 383       record_for_igvn(n->unique_out());
 384     }
 385   }
 386   // Remove useless macro and predicate opaq nodes
 387   for (int i = C->macro_count()-1; i >= 0; i--) {
 388     Node* n = C->macro_node(i);
 389     if (!useful.member(n)) {
 390       remove_macro_node(n);
 391     }
 392   }
 393   // Remove useless CastII nodes with range check dependency
 394   for (int i = range_check_cast_count() - 1; i >= 0; i--) {
 395     Node* cast = range_check_cast_node(i);
 396     if (!useful.member(cast)) {
 397       remove_range_check_cast(cast);
 398     }
 399   }
 400   // Remove useless expensive node
 401   for (int i = C->expensive_count()-1; i >= 0; i--) {
 402     Node* n = C->expensive_node(i);
 403     if (!useful.member(n)) {
 404       remove_expensive_node(n);
 405     }
 406   }
 407   for (int i = value_type_ptr_count() - 1; i >= 0; i--) {
 408     ValueTypePtrNode* vtptr = value_type_ptr(i);
 409     if (!useful.member(vtptr)) {
 410       remove_value_type_ptr(vtptr);
 411     }
 412   }
 413   // clean up the late inline lists
 414   remove_useless_late_inlines(&_string_late_inlines, useful);
 415   remove_useless_late_inlines(&_boxing_late_inlines, useful);
 416   remove_useless_late_inlines(&_late_inlines, useful);
 417   debug_only(verify_graph_edges(true/*check for no_dead_code*/);)
 418 }
 419 
 420 //------------------------------frame_size_in_words-----------------------------
 421 // frame_slots in units of words
 422 int Compile::frame_size_in_words() const {
 423   // shift is 0 in LP32 and 1 in LP64
 424   const int shift = (LogBytesPerWord - LogBytesPerInt);
 425   int words = _frame_slots >> shift;
 426   assert( words << shift == _frame_slots, "frame size must be properly aligned in LP64" );
 427   return words;
 428 }
 429 
 430 // To bang the stack of this compiled method we use the stack size
 431 // that the interpreter would need in case of a deoptimization. This
 432 // removes the need to bang the stack in the deoptimization blob which
 433 // in turn simplifies stack overflow handling.
 434 int Compile::bang_size_in_bytes() const {
 435   return MAX2(frame_size_in_bytes() + os::extra_bang_size_in_bytes(), _interpreter_frame_size);
 436 }
 437 
 438 // ============================================================================
 439 //------------------------------CompileWrapper---------------------------------
 440 class CompileWrapper : public StackObj {
 441   Compile *const _compile;
 442  public:
 443   CompileWrapper(Compile* compile);
 444 
 445   ~CompileWrapper();
 446 };
 447 
 448 CompileWrapper::CompileWrapper(Compile* compile) : _compile(compile) {
 449   // the Compile* pointer is stored in the current ciEnv:
 450   ciEnv* env = compile->env();
 451   assert(env == ciEnv::current(), "must already be a ciEnv active");
 452   assert(env->compiler_data() == NULL, "compile already active?");
 453   env->set_compiler_data(compile);
 454   assert(compile == Compile::current(), "sanity");
 455 
 456   compile->set_type_dict(NULL);
 457   compile->set_clone_map(new Dict(cmpkey, hashkey, _compile->comp_arena()));
 458   compile->clone_map().set_clone_idx(0);
 459   compile->set_type_hwm(NULL);
 460   compile->set_type_last_size(0);
 461   compile->set_last_tf(NULL, NULL);
 462   compile->set_indexSet_arena(NULL);
 463   compile->set_indexSet_free_block_list(NULL);
 464   compile->init_type_arena();
 465   Type::Initialize(compile);
 466   _compile->set_scratch_buffer_blob(NULL);
 467   _compile->begin_method();
 468   _compile->clone_map().set_debug(_compile->has_method() && _compile->directive()->CloneMapDebugOption);
 469 }
 470 CompileWrapper::~CompileWrapper() {
 471   _compile->end_method();
 472   if (_compile->scratch_buffer_blob() != NULL)
 473     BufferBlob::free(_compile->scratch_buffer_blob());
 474   _compile->env()->set_compiler_data(NULL);
 475 }
 476 
 477 
 478 //----------------------------print_compile_messages---------------------------
 479 void Compile::print_compile_messages() {
 480 #ifndef PRODUCT
 481   // Check if recompiling
 482   if (_subsume_loads == false && PrintOpto) {
 483     // Recompiling without allowing machine instructions to subsume loads
 484     tty->print_cr("*********************************************************");
 485     tty->print_cr("** Bailout: Recompile without subsuming loads          **");
 486     tty->print_cr("*********************************************************");
 487   }
 488   if (_do_escape_analysis != DoEscapeAnalysis && PrintOpto) {
 489     // Recompiling without escape analysis
 490     tty->print_cr("*********************************************************");
 491     tty->print_cr("** Bailout: Recompile without escape analysis          **");
 492     tty->print_cr("*********************************************************");
 493   }
 494   if (_eliminate_boxing != EliminateAutoBox && PrintOpto) {
 495     // Recompiling without boxing elimination
 496     tty->print_cr("*********************************************************");
 497     tty->print_cr("** Bailout: Recompile without boxing elimination       **");
 498     tty->print_cr("*********************************************************");
 499   }
 500   if (C->directive()->BreakAtCompileOption) {
 501     // Open the debugger when compiling this method.
 502     tty->print("### Breaking when compiling: ");
 503     method()->print_short_name();
 504     tty->cr();
 505     BREAKPOINT;
 506   }
 507 
 508   if( PrintOpto ) {
 509     if (is_osr_compilation()) {
 510       tty->print("[OSR]%3d", _compile_id);
 511     } else {
 512       tty->print("%3d", _compile_id);
 513     }
 514   }
 515 #endif
 516 }
 517 
 518 
 519 //-----------------------init_scratch_buffer_blob------------------------------
 520 // Construct a temporary BufferBlob and cache it for this compile.
 521 void Compile::init_scratch_buffer_blob(int const_size) {
 522   // If there is already a scratch buffer blob allocated and the
 523   // constant section is big enough, use it.  Otherwise free the
 524   // current and allocate a new one.
 525   BufferBlob* blob = scratch_buffer_blob();
 526   if ((blob != NULL) && (const_size <= _scratch_const_size)) {
 527     // Use the current blob.
 528   } else {
 529     if (blob != NULL) {
 530       BufferBlob::free(blob);
 531     }
 532 
 533     ResourceMark rm;
 534     _scratch_const_size = const_size;
 535     int size = (MAX_inst_size + MAX_stubs_size + _scratch_const_size);
 536     blob = BufferBlob::create("Compile::scratch_buffer", size);
 537     // Record the buffer blob for next time.
 538     set_scratch_buffer_blob(blob);
 539     // Have we run out of code space?
 540     if (scratch_buffer_blob() == NULL) {
 541       // Let CompilerBroker disable further compilations.
 542       record_failure("Not enough space for scratch buffer in CodeCache");
 543       return;
 544     }
 545   }
 546 
 547   // Initialize the relocation buffers
 548   relocInfo* locs_buf = (relocInfo*) blob->content_end() - MAX_locs_size;
 549   set_scratch_locs_memory(locs_buf);
 550 }
 551 
 552 
 553 //-----------------------scratch_emit_size-------------------------------------
 554 // Helper function that computes size by emitting code
 555 uint Compile::scratch_emit_size(const Node* n) {
 556   // Start scratch_emit_size section.
 557   set_in_scratch_emit_size(true);
 558 
 559   // Emit into a trash buffer and count bytes emitted.
 560   // This is a pretty expensive way to compute a size,
 561   // but it works well enough if seldom used.
 562   // All common fixed-size instructions are given a size
 563   // method by the AD file.
 564   // Note that the scratch buffer blob and locs memory are
 565   // allocated at the beginning of the compile task, and
 566   // may be shared by several calls to scratch_emit_size.
 567   // The allocation of the scratch buffer blob is particularly
 568   // expensive, since it has to grab the code cache lock.
 569   BufferBlob* blob = this->scratch_buffer_blob();
 570   assert(blob != NULL, "Initialize BufferBlob at start");
 571   assert(blob->size() > MAX_inst_size, "sanity");
 572   relocInfo* locs_buf = scratch_locs_memory();
 573   address blob_begin = blob->content_begin();
 574   address blob_end   = (address)locs_buf;
 575   assert(blob->contains(blob_end), "sanity");
 576   CodeBuffer buf(blob_begin, blob_end - blob_begin);
 577   buf.initialize_consts_size(_scratch_const_size);
 578   buf.initialize_stubs_size(MAX_stubs_size);
 579   assert(locs_buf != NULL, "sanity");
 580   int lsize = MAX_locs_size / 3;
 581   buf.consts()->initialize_shared_locs(&locs_buf[lsize * 0], lsize);
 582   buf.insts()->initialize_shared_locs( &locs_buf[lsize * 1], lsize);
 583   buf.stubs()->initialize_shared_locs( &locs_buf[lsize * 2], lsize);
 584   // Mark as scratch buffer.
 585   buf.consts()->set_scratch_emit();
 586   buf.insts()->set_scratch_emit();
 587   buf.stubs()->set_scratch_emit();
 588 
 589   // Do the emission.
 590 
 591   Label fakeL; // Fake label for branch instructions.
 592   Label*   saveL = NULL;
 593   uint save_bnum = 0;
 594   bool is_branch = n->is_MachBranch();
 595   if (is_branch) {
 596     MacroAssembler masm(&buf);
 597     masm.bind(fakeL);
 598     n->as_MachBranch()->save_label(&saveL, &save_bnum);
 599     n->as_MachBranch()->label_set(&fakeL, 0);
 600   }
 601   n->emit(buf, this->regalloc());
 602 
 603   // Emitting into the scratch buffer should not fail
 604   assert (!failing(), "Must not have pending failure. Reason is: %s", failure_reason());
 605 
 606   if (is_branch) // Restore label.
 607     n->as_MachBranch()->label_set(saveL, save_bnum);
 608 
 609   // End scratch_emit_size section.
 610   set_in_scratch_emit_size(false);
 611 
 612   return buf.insts_size();
 613 }
 614 
 615 
 616 // ============================================================================
 617 //------------------------------Compile standard-------------------------------
 618 debug_only( int Compile::_debug_idx = 100000; )
 619 
 620 // Compile a method.  entry_bci is -1 for normal compilations and indicates
 621 // the continuation bci for on stack replacement.
 622 
 623 
 624 Compile::Compile( ciEnv* ci_env, C2Compiler* compiler, ciMethod* target, int osr_bci,
 625                   bool subsume_loads, bool do_escape_analysis, bool eliminate_boxing, DirectiveSet* directive)
 626                 : Phase(Compiler),
 627                   _env(ci_env),
 628                   _directive(directive),
 629                   _log(ci_env->log()),
 630                   _compile_id(ci_env->compile_id()),
 631                   _save_argument_registers(false),
 632                   _stub_name(NULL),
 633                   _stub_function(NULL),
 634                   _stub_entry_point(NULL),
 635                   _method(target),
 636                   _entry_bci(osr_bci),
 637                   _initial_gvn(NULL),
 638                   _for_igvn(NULL),
 639                   _warm_calls(NULL),
 640                   _subsume_loads(subsume_loads),
 641                   _do_escape_analysis(do_escape_analysis),
 642                   _eliminate_boxing(eliminate_boxing),
 643                   _failure_reason(NULL),
 644                   _code_buffer("Compile::Fill_buffer"),
 645                   _orig_pc_slot(0),
 646                   _orig_pc_slot_offset_in_bytes(0),
 647                   _has_method_handle_invokes(false),
 648                   _mach_constant_base_node(NULL),
 649                   _node_bundling_limit(0),
 650                   _node_bundling_base(NULL),
 651                   _java_calls(0),
 652                   _inner_loops(0),
 653                   _scratch_const_size(-1),
 654                   _in_scratch_emit_size(false),
 655                   _dead_node_list(comp_arena()),
 656                   _dead_node_count(0),
 657 #ifndef PRODUCT
 658                   _trace_opto_output(directive->TraceOptoOutputOption),
 659                   _in_dump_cnt(0),
 660                   _printer(IdealGraphPrinter::printer()),
 661 #endif
 662                   _congraph(NULL),
 663                   _comp_arena(mtCompiler),
 664                   _node_arena(mtCompiler),
 665                   _old_arena(mtCompiler),
 666                   _Compile_types(mtCompiler),
 667                   _replay_inline_data(NULL),
 668                   _late_inlines(comp_arena(), 2, 0, NULL),
 669                   _string_late_inlines(comp_arena(), 2, 0, NULL),
 670                   _boxing_late_inlines(comp_arena(), 2, 0, NULL),
 671                   _late_inlines_pos(0),
 672                   _number_of_mh_late_inlines(0),
 673                   _inlining_progress(false),
 674                   _inlining_incrementally(false),
 675                   _print_inlining_list(NULL),
 676                   _print_inlining_stream(NULL),
 677                   _print_inlining_idx(0),
 678                   _print_inlining_output(NULL),
 679                   _interpreter_frame_size(0),
 680                   _max_node_limit(MaxNodeLimit),
 681                   _has_reserved_stack_access(target->has_reserved_stack_access()) {
 682   C = this;
 683 #ifndef PRODUCT
 684   if (_printer != NULL) {
 685     _printer->set_compile(this);
 686   }
 687 #endif
 688   CompileWrapper cw(this);
 689 
 690   if (CITimeVerbose) {
 691     tty->print(" ");
 692     target->holder()->name()->print();
 693     tty->print(".");
 694     target->print_short_name();
 695     tty->print("  ");
 696   }
 697   TraceTime t1("Total compilation time", &_t_totalCompilation, CITime, CITimeVerbose);
 698   TraceTime t2(NULL, &_t_methodCompilation, CITime, false);
 699 
 700 #ifndef PRODUCT
 701   bool print_opto_assembly = directive->PrintOptoAssemblyOption;
 702   if (!print_opto_assembly) {
 703     bool print_assembly = directive->PrintAssemblyOption;
 704     if (print_assembly && !Disassembler::can_decode()) {
 705       tty->print_cr("PrintAssembly request changed to PrintOptoAssembly");
 706       print_opto_assembly = true;
 707     }
 708   }
 709   set_print_assembly(print_opto_assembly);
 710   set_parsed_irreducible_loop(false);
 711 
 712   if (directive->ReplayInlineOption) {
 713     _replay_inline_data = ciReplay::load_inline_data(method(), entry_bci(), ci_env->comp_level());
 714   }
 715 #endif
 716   set_print_inlining(directive->PrintInliningOption || PrintOptoInlining);
 717   set_print_intrinsics(directive->PrintIntrinsicsOption);
 718   set_has_irreducible_loop(true); // conservative until build_loop_tree() reset it
 719 
 720   if (ProfileTraps RTM_OPT_ONLY( || UseRTMLocking )) {
 721     // Make sure the method being compiled gets its own MDO,
 722     // so we can at least track the decompile_count().
 723     // Need MDO to record RTM code generation state.
 724     method()->ensure_method_data();
 725   }
 726 
 727   Init(::AliasLevel);
 728 
 729 
 730   print_compile_messages();
 731 
 732   _ilt = InlineTree::build_inline_tree_root();
 733 
 734   // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
 735   assert(num_alias_types() >= AliasIdxRaw, "");
 736 
 737 #define MINIMUM_NODE_HASH  1023
 738   // Node list that Iterative GVN will start with
 739   Unique_Node_List for_igvn(comp_arena());
 740   set_for_igvn(&for_igvn);
 741 
 742   // GVN that will be run immediately on new nodes
 743   uint estimated_size = method()->code_size()*4+64;
 744   estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
 745   PhaseGVN gvn(node_arena(), estimated_size);
 746   set_initial_gvn(&gvn);
 747 
 748   print_inlining_init();
 749   { // Scope for timing the parser
 750     TracePhase tp("parse", &timers[_t_parser]);
 751 
 752     // Put top into the hash table ASAP.
 753     initial_gvn()->transform_no_reclaim(top());
 754 
 755     // Set up tf(), start(), and find a CallGenerator.
 756     CallGenerator* cg = NULL;
 757     if (is_osr_compilation()) {
 758       const TypeTuple *domain = StartOSRNode::osr_domain();
 759       const TypeTuple *range = TypeTuple::make_range(method()->signature());
 760       init_tf(TypeFunc::make(domain, range));
 761       StartNode* s = new StartOSRNode(root(), domain);
 762       initial_gvn()->set_type_bottom(s);
 763       init_start(s);
 764       cg = CallGenerator::for_osr(method(), entry_bci());
 765     } else {
 766       // Normal case.
 767       init_tf(TypeFunc::make(method()));
 768       StartNode* s = new StartNode(root(), tf()->domain_cc());
 769       initial_gvn()->set_type_bottom(s);
 770       init_start(s);
 771       if (method()->intrinsic_id() == vmIntrinsics::_Reference_get && UseG1GC) {
 772         // With java.lang.ref.reference.get() we must go through the
 773         // intrinsic when G1 is enabled - even when get() is the root
 774         // method of the compile - so that, if necessary, the value in
 775         // the referent field of the reference object gets recorded by
 776         // the pre-barrier code.
 777         // Specifically, if G1 is enabled, the value in the referent
 778         // field is recorded by the G1 SATB pre barrier. This will
 779         // result in the referent being marked live and the reference
 780         // object removed from the list of discovered references during
 781         // reference processing.
 782         cg = find_intrinsic(method(), false);
 783       }
 784       if (cg == NULL) {
 785         float past_uses = method()->interpreter_invocation_count();
 786         float expected_uses = past_uses;
 787         cg = CallGenerator::for_inline(method(), expected_uses);
 788       }
 789     }
 790     if (failing())  return;
 791     if (cg == NULL) {
 792       record_method_not_compilable("cannot parse method");
 793       return;
 794     }
 795     JVMState* jvms = build_start_state(start(), tf());
 796     if ((jvms = cg->generate(jvms)) == NULL) {
 797       if (!failure_reason_is(C2Compiler::retry_class_loading_during_parsing())) {
 798         record_method_not_compilable("method parse failed");
 799       }
 800       return;
 801     }
 802     GraphKit kit(jvms);
 803 
 804     if (!kit.stopped()) {
 805       // Accept return values, and transfer control we know not where.
 806       // This is done by a special, unique ReturnNode bound to root.
 807       return_values(kit.jvms());
 808     }
 809 
 810     if (kit.has_exceptions()) {
 811       // Any exceptions that escape from this call must be rethrown
 812       // to whatever caller is dynamically above us on the stack.
 813       // This is done by a special, unique RethrowNode bound to root.
 814       rethrow_exceptions(kit.transfer_exceptions_into_jvms());
 815     }
 816 
 817     assert(IncrementalInline || (_late_inlines.length() == 0 && !has_mh_late_inlines()), "incremental inlining is off");
 818 
 819     if (_late_inlines.length() == 0 && !has_mh_late_inlines() && !failing() && has_stringbuilder()) {
 820       inline_string_calls(true);
 821     }
 822 
 823     if (failing())  return;
 824 
 825     print_method(PHASE_BEFORE_REMOVEUSELESS, 3);
 826 
 827     // Remove clutter produced by parsing.
 828     if (!failing()) {
 829       ResourceMark rm;
 830       PhaseRemoveUseless pru(initial_gvn(), &for_igvn);
 831     }
 832   }
 833 
 834   // Note:  Large methods are capped off in do_one_bytecode().
 835   if (failing())  return;
 836 
 837   // After parsing, node notes are no longer automagic.
 838   // They must be propagated by register_new_node_with_optimizer(),
 839   // clone(), or the like.
 840   set_default_node_notes(NULL);
 841 
 842   for (;;) {
 843     int successes = Inline_Warm();
 844     if (failing())  return;
 845     if (successes == 0)  break;
 846   }
 847 
 848   // Drain the list.
 849   Finish_Warm();
 850 #ifndef PRODUCT
 851   if (_printer && _printer->should_print(1)) {
 852     _printer->print_inlining();
 853   }
 854 #endif
 855 
 856   if (failing())  return;
 857   NOT_PRODUCT( verify_graph_edges(); )
 858 
 859   // Now optimize
 860   Optimize();
 861   if (failing())  return;
 862   NOT_PRODUCT( verify_graph_edges(); )
 863 
 864 #ifndef PRODUCT
 865   if (PrintIdeal) {
 866     ttyLocker ttyl;  // keep the following output all in one block
 867     // This output goes directly to the tty, not the compiler log.
 868     // To enable tools to match it up with the compilation activity,
 869     // be sure to tag this tty output with the compile ID.
 870     if (xtty != NULL) {
 871       xtty->head("ideal compile_id='%d'%s", compile_id(),
 872                  is_osr_compilation()    ? " compile_kind='osr'" :
 873                  "");
 874     }
 875     root()->dump(9999);
 876     if (xtty != NULL) {
 877       xtty->tail("ideal");
 878     }
 879   }
 880 #endif
 881 
 882   NOT_PRODUCT( verify_barriers(); )
 883 
 884   // Dump compilation data to replay it.
 885   if (directive->DumpReplayOption) {
 886     env()->dump_replay_data(_compile_id);
 887   }
 888   if (directive->DumpInlineOption && (ilt() != NULL)) {
 889     env()->dump_inline_data(_compile_id);
 890   }
 891 
 892   // Now that we know the size of all the monitors we can add a fixed slot
 893   // for the original deopt pc.
 894 
 895   _orig_pc_slot =  fixed_slots();
 896   int next_slot = _orig_pc_slot + (sizeof(address) / VMRegImpl::stack_slot_size);
 897   set_fixed_slots(next_slot);
 898 
 899   // Compute when to use implicit null checks. Used by matching trap based
 900   // nodes and NullCheck optimization.
 901   set_allowed_deopt_reasons();
 902 
 903   // Now generate code
 904   Code_Gen();
 905   if (failing())  return;
 906 
 907   // Check if we want to skip execution of all compiled code.
 908   {
 909 #ifndef PRODUCT
 910     if (OptoNoExecute) {
 911       record_method_not_compilable("+OptoNoExecute");  // Flag as failed
 912       return;
 913     }
 914 #endif
 915     TracePhase tp("install_code", &timers[_t_registerMethod]);
 916 
 917     if (is_osr_compilation()) {
 918       _code_offsets.set_value(CodeOffsets::Verified_Entry, 0);
 919       _code_offsets.set_value(CodeOffsets::OSR_Entry, _first_block_size);
 920     } else {
 921       _code_offsets.set_value(CodeOffsets::Verified_Entry, _first_block_size);
 922       _code_offsets.set_value(CodeOffsets::OSR_Entry, 0);
 923     }
 924 
 925     env()->register_method(_method, _entry_bci,
 926                            &_code_offsets,
 927                            _orig_pc_slot_offset_in_bytes,
 928                            code_buffer(),
 929                            frame_size_in_words(), _oop_map_set,
 930                            &_handler_table, &_inc_table,
 931                            compiler,
 932                            has_unsafe_access(),
 933                            SharedRuntime::is_wide_vector(max_vector_size()),
 934                            rtm_state()
 935                            );
 936 
 937     if (log() != NULL) // Print code cache state into compiler log
 938       log()->code_cache_state();
 939   }
 940 }
 941 
 942 //------------------------------Compile----------------------------------------
 943 // Compile a runtime stub
 944 Compile::Compile( ciEnv* ci_env,
 945                   TypeFunc_generator generator,
 946                   address stub_function,
 947                   const char *stub_name,
 948                   int is_fancy_jump,
 949                   bool pass_tls,
 950                   bool save_arg_registers,
 951                   bool return_pc,
 952                   DirectiveSet* directive)
 953   : Phase(Compiler),
 954     _env(ci_env),
 955     _directive(directive),
 956     _log(ci_env->log()),
 957     _compile_id(0),
 958     _save_argument_registers(save_arg_registers),
 959     _method(NULL),
 960     _stub_name(stub_name),
 961     _stub_function(stub_function),
 962     _stub_entry_point(NULL),
 963     _entry_bci(InvocationEntryBci),
 964     _initial_gvn(NULL),
 965     _for_igvn(NULL),
 966     _warm_calls(NULL),
 967     _orig_pc_slot(0),
 968     _orig_pc_slot_offset_in_bytes(0),
 969     _subsume_loads(true),
 970     _do_escape_analysis(false),
 971     _eliminate_boxing(false),
 972     _failure_reason(NULL),
 973     _code_buffer("Compile::Fill_buffer"),
 974     _has_method_handle_invokes(false),
 975     _mach_constant_base_node(NULL),
 976     _node_bundling_limit(0),
 977     _node_bundling_base(NULL),
 978     _java_calls(0),
 979     _inner_loops(0),
 980 #ifndef PRODUCT
 981     _trace_opto_output(directive->TraceOptoOutputOption),
 982     _in_dump_cnt(0),
 983     _printer(NULL),
 984 #endif
 985     _comp_arena(mtCompiler),
 986     _node_arena(mtCompiler),
 987     _old_arena(mtCompiler),
 988     _Compile_types(mtCompiler),
 989     _dead_node_list(comp_arena()),
 990     _dead_node_count(0),
 991     _congraph(NULL),
 992     _replay_inline_data(NULL),
 993     _number_of_mh_late_inlines(0),
 994     _inlining_progress(false),
 995     _inlining_incrementally(false),
 996     _print_inlining_list(NULL),
 997     _print_inlining_stream(NULL),
 998     _print_inlining_idx(0),
 999     _print_inlining_output(NULL),
1000     _allowed_reasons(0),
1001     _interpreter_frame_size(0),
1002     _max_node_limit(MaxNodeLimit) {
1003   C = this;
1004 
1005   TraceTime t1(NULL, &_t_totalCompilation, CITime, false);
1006   TraceTime t2(NULL, &_t_stubCompilation, CITime, false);
1007 
1008 #ifndef PRODUCT
1009   set_print_assembly(PrintFrameConverterAssembly);
1010   set_parsed_irreducible_loop(false);
1011 #endif
1012   set_has_irreducible_loop(false); // no loops
1013 
1014   CompileWrapper cw(this);
1015   Init(/*AliasLevel=*/ 0);
1016   init_tf((*generator)());
1017 
1018   {
1019     // The following is a dummy for the sake of GraphKit::gen_stub
1020     Unique_Node_List for_igvn(comp_arena());
1021     set_for_igvn(&for_igvn);  // not used, but some GraphKit guys push on this
1022     PhaseGVN gvn(Thread::current()->resource_area(),255);
1023     set_initial_gvn(&gvn);    // not significant, but GraphKit guys use it pervasively
1024     gvn.transform_no_reclaim(top());
1025 
1026     GraphKit kit;
1027     kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
1028   }
1029 
1030   NOT_PRODUCT( verify_graph_edges(); )
1031   Code_Gen();
1032   if (failing())  return;
1033 
1034 
1035   // Entry point will be accessed using compile->stub_entry_point();
1036   if (code_buffer() == NULL) {
1037     Matcher::soft_match_failure();
1038   } else {
1039     if (PrintAssembly && (WizardMode || Verbose))
1040       tty->print_cr("### Stub::%s", stub_name);
1041 
1042     if (!failing()) {
1043       assert(_fixed_slots == 0, "no fixed slots used for runtime stubs");
1044 
1045       // Make the NMethod
1046       // For now we mark the frame as never safe for profile stackwalking
1047       RuntimeStub *rs = RuntimeStub::new_runtime_stub(stub_name,
1048                                                       code_buffer(),
1049                                                       CodeOffsets::frame_never_safe,
1050                                                       // _code_offsets.value(CodeOffsets::Frame_Complete),
1051                                                       frame_size_in_words(),
1052                                                       _oop_map_set,
1053                                                       save_arg_registers);
1054       assert(rs != NULL && rs->is_runtime_stub(), "sanity check");
1055 
1056       _stub_entry_point = rs->entry_point();
1057     }
1058   }
1059 }
1060 
1061 //------------------------------Init-------------------------------------------
1062 // Prepare for a single compilation
1063 void Compile::Init(int aliaslevel) {
1064   _unique  = 0;
1065   _regalloc = NULL;
1066 
1067   _tf      = NULL;  // filled in later
1068   _top     = NULL;  // cached later
1069   _matcher = NULL;  // filled in later
1070   _cfg     = NULL;  // filled in later
1071 
1072   set_24_bit_selection_and_mode(Use24BitFP, false);
1073 
1074   _node_note_array = NULL;
1075   _default_node_notes = NULL;
1076   DEBUG_ONLY( _modified_nodes = NULL; ) // Used in Optimize()
1077 
1078   _immutable_memory = NULL; // filled in at first inquiry
1079 
1080   // Globally visible Nodes
1081   // First set TOP to NULL to give safe behavior during creation of RootNode
1082   set_cached_top_node(NULL);
1083   set_root(new RootNode());
1084   // Now that you have a Root to point to, create the real TOP
1085   set_cached_top_node( new ConNode(Type::TOP) );
1086   set_recent_alloc(NULL, NULL);
1087 
1088   // Create Debug Information Recorder to record scopes, oopmaps, etc.
1089   env()->set_oop_recorder(new OopRecorder(env()->arena()));
1090   env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
1091   env()->set_dependencies(new Dependencies(env()));
1092 
1093   _fixed_slots = 0;
1094   set_has_split_ifs(false);
1095   set_has_loops(has_method() && method()->has_loops()); // first approximation
1096   set_has_stringbuilder(false);
1097   set_has_boxed_value(false);
1098   _trap_can_recompile = false;  // no traps emitted yet
1099   _major_progress = true; // start out assuming good things will happen
1100   set_has_unsafe_access(false);
1101   set_max_vector_size(0);
1102   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
1103   set_decompile_count(0);
1104 
1105   set_do_freq_based_layout(_directive->BlockLayoutByFrequencyOption);
1106   set_num_loop_opts(LoopOptsCount);
1107   set_do_inlining(Inline);
1108   set_max_inline_size(MaxInlineSize);
1109   set_freq_inline_size(FreqInlineSize);
1110   set_do_scheduling(OptoScheduling);
1111   set_do_count_invocations(false);
1112   set_do_method_data_update(false);
1113 
1114   set_do_vector_loop(false);
1115 
1116   if (AllowVectorizeOnDemand) {
1117     if (has_method() && (_directive->VectorizeOption || _directive->VectorizeDebugOption)) {
1118       set_do_vector_loop(true);
1119       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());})
1120     } else if (has_method() && method()->name() != 0 &&
1121                method()->intrinsic_id() == vmIntrinsics::_forEachRemaining) {
1122       set_do_vector_loop(true);
1123     }
1124   }
1125   set_use_cmove(UseCMoveUnconditionally /* || do_vector_loop()*/); //TODO: consider do_vector_loop() mandate use_cmove unconditionally
1126   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());})
1127 
1128   set_age_code(has_method() && method()->profile_aging());
1129   set_rtm_state(NoRTM); // No RTM lock eliding by default
1130   _max_node_limit = _directive->MaxNodeLimitOption;
1131 
1132 #if INCLUDE_RTM_OPT
1133   if (UseRTMLocking && has_method() && (method()->method_data_or_null() != NULL)) {
1134     int rtm_state = method()->method_data()->rtm_state();
1135     if (method_has_option("NoRTMLockEliding") || ((rtm_state & NoRTM) != 0)) {
1136       // Don't generate RTM lock eliding code.
1137       set_rtm_state(NoRTM);
1138     } else if (method_has_option("UseRTMLockEliding") || ((rtm_state & UseRTM) != 0) || !UseRTMDeopt) {
1139       // Generate RTM lock eliding code without abort ratio calculation code.
1140       set_rtm_state(UseRTM);
1141     } else if (UseRTMDeopt) {
1142       // Generate RTM lock eliding code and include abort ratio calculation
1143       // code if UseRTMDeopt is on.
1144       set_rtm_state(ProfileRTM);
1145     }
1146   }
1147 #endif
1148   if (debug_info()->recording_non_safepoints()) {
1149     set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
1150                         (comp_arena(), 8, 0, NULL));
1151     set_default_node_notes(Node_Notes::make(this));
1152   }
1153 
1154   // // -- Initialize types before each compile --
1155   // // Update cached type information
1156   // if( _method && _method->constants() )
1157   //   Type::update_loaded_types(_method, _method->constants());
1158 
1159   // Init alias_type map.
1160   if (!_do_escape_analysis && aliaslevel == 3)
1161     aliaslevel = 2;  // No unique types without escape analysis
1162   _AliasLevel = aliaslevel;
1163   const int grow_ats = 16;
1164   _max_alias_types = grow_ats;
1165   _alias_types   = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
1166   AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType,  grow_ats);
1167   Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
1168   {
1169     for (int i = 0; i < grow_ats; i++)  _alias_types[i] = &ats[i];
1170   }
1171   // Initialize the first few types.
1172   _alias_types[AliasIdxTop]->Init(AliasIdxTop, NULL);
1173   _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
1174   _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
1175   _num_alias_types = AliasIdxRaw+1;
1176   // Zero out the alias type cache.
1177   Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
1178   // A NULL adr_type hits in the cache right away.  Preload the right answer.
1179   probe_alias_cache(NULL)->_index = AliasIdxTop;
1180 
1181   _intrinsics = NULL;
1182   _macro_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1183   _predicate_opaqs = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1184   _expensive_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1185   _range_check_casts = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1186   _value_type_ptr_nodes = new(comp_arena()) GrowableArray<ValueTypePtrNode*>(comp_arena(), 8,  0, NULL);
1187   register_library_intrinsics();
1188 }
1189 
1190 //---------------------------init_start----------------------------------------
1191 // Install the StartNode on this compile object.
1192 void Compile::init_start(StartNode* s) {
1193   if (failing())
1194     return; // already failing
1195   assert(s == start(), "");
1196 }
1197 
1198 /**
1199  * Return the 'StartNode'. We must not have a pending failure, since the ideal graph
1200  * can be in an inconsistent state, i.e., we can get segmentation faults when traversing
1201  * the ideal graph.
1202  */
1203 StartNode* Compile::start() const {
1204   assert (!failing(), "Must not have pending failure. Reason is: %s", failure_reason());
1205   for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
1206     Node* start = root()->fast_out(i);
1207     if (start->is_Start()) {
1208       return start->as_Start();
1209     }
1210   }
1211   fatal("Did not find Start node!");
1212   return NULL;
1213 }
1214 
1215 //-------------------------------immutable_memory-------------------------------------
1216 // Access immutable memory
1217 Node* Compile::immutable_memory() {
1218   if (_immutable_memory != NULL) {
1219     return _immutable_memory;
1220   }
1221   StartNode* s = start();
1222   for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
1223     Node *p = s->fast_out(i);
1224     if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
1225       _immutable_memory = p;
1226       return _immutable_memory;
1227     }
1228   }
1229   ShouldNotReachHere();
1230   return NULL;
1231 }
1232 
1233 //----------------------set_cached_top_node------------------------------------
1234 // Install the cached top node, and make sure Node::is_top works correctly.
1235 void Compile::set_cached_top_node(Node* tn) {
1236   if (tn != NULL)  verify_top(tn);
1237   Node* old_top = _top;
1238   _top = tn;
1239   // Calling Node::setup_is_top allows the nodes the chance to adjust
1240   // their _out arrays.
1241   if (_top != NULL)     _top->setup_is_top();
1242   if (old_top != NULL)  old_top->setup_is_top();
1243   assert(_top == NULL || top()->is_top(), "");
1244 }
1245 
1246 #ifdef ASSERT
1247 uint Compile::count_live_nodes_by_graph_walk() {
1248   Unique_Node_List useful(comp_arena());
1249   // Get useful node list by walking the graph.
1250   identify_useful_nodes(useful);
1251   return useful.size();
1252 }
1253 
1254 void Compile::print_missing_nodes() {
1255 
1256   // Return if CompileLog is NULL and PrintIdealNodeCount is false.
1257   if ((_log == NULL) && (! PrintIdealNodeCount)) {
1258     return;
1259   }
1260 
1261   // This is an expensive function. It is executed only when the user
1262   // specifies VerifyIdealNodeCount option or otherwise knows the
1263   // additional work that needs to be done to identify reachable nodes
1264   // by walking the flow graph and find the missing ones using
1265   // _dead_node_list.
1266 
1267   Unique_Node_List useful(comp_arena());
1268   // Get useful node list by walking the graph.
1269   identify_useful_nodes(useful);
1270 
1271   uint l_nodes = C->live_nodes();
1272   uint l_nodes_by_walk = useful.size();
1273 
1274   if (l_nodes != l_nodes_by_walk) {
1275     if (_log != NULL) {
1276       _log->begin_head("mismatched_nodes count='%d'", abs((int) (l_nodes - l_nodes_by_walk)));
1277       _log->stamp();
1278       _log->end_head();
1279     }
1280     VectorSet& useful_member_set = useful.member_set();
1281     int last_idx = l_nodes_by_walk;
1282     for (int i = 0; i < last_idx; i++) {
1283       if (useful_member_set.test(i)) {
1284         if (_dead_node_list.test(i)) {
1285           if (_log != NULL) {
1286             _log->elem("mismatched_node_info node_idx='%d' type='both live and dead'", i);
1287           }
1288           if (PrintIdealNodeCount) {
1289             // Print the log message to tty
1290               tty->print_cr("mismatched_node idx='%d' both live and dead'", i);
1291               useful.at(i)->dump();
1292           }
1293         }
1294       }
1295       else if (! _dead_node_list.test(i)) {
1296         if (_log != NULL) {
1297           _log->elem("mismatched_node_info node_idx='%d' type='neither live nor dead'", i);
1298         }
1299         if (PrintIdealNodeCount) {
1300           // Print the log message to tty
1301           tty->print_cr("mismatched_node idx='%d' type='neither live nor dead'", i);
1302         }
1303       }
1304     }
1305     if (_log != NULL) {
1306       _log->tail("mismatched_nodes");
1307     }
1308   }
1309 }
1310 void Compile::record_modified_node(Node* n) {
1311   if (_modified_nodes != NULL && !_inlining_incrementally &&
1312       n->outcnt() != 0 && !n->is_Con()) {
1313     _modified_nodes->push(n);
1314   }
1315 }
1316 
1317 void Compile::remove_modified_node(Node* n) {
1318   if (_modified_nodes != NULL) {
1319     _modified_nodes->remove(n);
1320   }
1321 }
1322 #endif
1323 
1324 #ifndef PRODUCT
1325 void Compile::verify_top(Node* tn) const {
1326   if (tn != NULL) {
1327     assert(tn->is_Con(), "top node must be a constant");
1328     assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
1329     assert(tn->in(0) != NULL, "must have live top node");
1330   }
1331 }
1332 #endif
1333 
1334 
1335 ///-------------------Managing Per-Node Debug & Profile Info-------------------
1336 
1337 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
1338   guarantee(arr != NULL, "");
1339   int num_blocks = arr->length();
1340   if (grow_by < num_blocks)  grow_by = num_blocks;
1341   int num_notes = grow_by * _node_notes_block_size;
1342   Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
1343   Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
1344   while (num_notes > 0) {
1345     arr->append(notes);
1346     notes     += _node_notes_block_size;
1347     num_notes -= _node_notes_block_size;
1348   }
1349   assert(num_notes == 0, "exact multiple, please");
1350 }
1351 
1352 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
1353   if (source == NULL || dest == NULL)  return false;
1354 
1355   if (dest->is_Con())
1356     return false;               // Do not push debug info onto constants.
1357 
1358 #ifdef ASSERT
1359   // Leave a bread crumb trail pointing to the original node:
1360   if (dest != NULL && dest != source && dest->debug_orig() == NULL) {
1361     dest->set_debug_orig(source);
1362   }
1363 #endif
1364 
1365   if (node_note_array() == NULL)
1366     return false;               // Not collecting any notes now.
1367 
1368   // This is a copy onto a pre-existing node, which may already have notes.
1369   // If both nodes have notes, do not overwrite any pre-existing notes.
1370   Node_Notes* source_notes = node_notes_at(source->_idx);
1371   if (source_notes == NULL || source_notes->is_clear())  return false;
1372   Node_Notes* dest_notes   = node_notes_at(dest->_idx);
1373   if (dest_notes == NULL || dest_notes->is_clear()) {
1374     return set_node_notes_at(dest->_idx, source_notes);
1375   }
1376 
1377   Node_Notes merged_notes = (*source_notes);
1378   // The order of operations here ensures that dest notes will win...
1379   merged_notes.update_from(dest_notes);
1380   return set_node_notes_at(dest->_idx, &merged_notes);
1381 }
1382 
1383 
1384 //--------------------------allow_range_check_smearing-------------------------
1385 // Gating condition for coalescing similar range checks.
1386 // Sometimes we try 'speculatively' replacing a series of a range checks by a
1387 // single covering check that is at least as strong as any of them.
1388 // If the optimization succeeds, the simplified (strengthened) range check
1389 // will always succeed.  If it fails, we will deopt, and then give up
1390 // on the optimization.
1391 bool Compile::allow_range_check_smearing() const {
1392   // If this method has already thrown a range-check,
1393   // assume it was because we already tried range smearing
1394   // and it failed.
1395   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
1396   return !already_trapped;
1397 }
1398 
1399 
1400 //------------------------------flatten_alias_type-----------------------------
1401 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
1402   int offset = tj->offset();
1403   TypePtr::PTR ptr = tj->ptr();
1404 
1405   // Known instance (scalarizable allocation) alias only with itself.
1406   bool is_known_inst = tj->isa_oopptr() != NULL &&
1407                        tj->is_oopptr()->is_known_instance();
1408 
1409   // Process weird unsafe references.
1410   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
1411     assert(InlineUnsafeOps, "indeterminate pointers come only from unsafe ops");
1412     assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
1413     tj = TypeOopPtr::BOTTOM;
1414     ptr = tj->ptr();
1415     offset = tj->offset();
1416   }
1417 
1418   // Array pointers need some flattening
1419   const TypeAryPtr *ta = tj->isa_aryptr();
1420   if (ta && ta->is_stable()) {
1421     // Erase stability property for alias analysis.
1422     tj = ta = ta->cast_to_stable(false);
1423   }
1424   if( ta && is_known_inst ) {
1425     if ( offset != Type::OffsetBot &&
1426          offset > arrayOopDesc::length_offset_in_bytes() ) {
1427       offset = Type::OffsetBot; // Flatten constant access into array body only
1428       tj = ta = TypeAryPtr::make(ptr, ta->ary(), ta->klass(), true, Type::Offset(offset), ta->field_offset(), ta->instance_id());
1429     }
1430   } else if( ta && _AliasLevel >= 2 ) {
1431     // For arrays indexed by constant indices, we flatten the alias
1432     // space to include all of the array body.  Only the header, klass
1433     // and array length can be accessed un-aliased.
1434     // For flattened value type array, each field has its own slice so
1435     // we must include the field offset.
1436     if( offset != Type::OffsetBot ) {
1437       if( ta->const_oop() ) { // MethodData* or Method*
1438         offset = Type::OffsetBot;   // Flatten constant access into array body
1439         tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),ta->ary(),ta->klass(),false,Type::Offset(offset), ta->field_offset());
1440       } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
1441         // range is OK as-is.
1442         tj = ta = TypeAryPtr::RANGE;
1443       } else if( offset == oopDesc::klass_offset_in_bytes() ) {
1444         tj = TypeInstPtr::KLASS; // all klass loads look alike
1445         ta = TypeAryPtr::RANGE; // generic ignored junk
1446         ptr = TypePtr::BotPTR;
1447       } else if( offset == oopDesc::mark_offset_in_bytes() ) {
1448         tj = TypeInstPtr::MARK;
1449         ta = TypeAryPtr::RANGE; // generic ignored junk
1450         ptr = TypePtr::BotPTR;
1451       } else {                  // Random constant offset into array body
1452         offset = Type::OffsetBot;   // Flatten constant access into array body
1453         tj = ta = TypeAryPtr::make(ptr,ta->ary(),ta->klass(),false,Type::Offset(offset), ta->field_offset());
1454       }
1455     }
1456     // Arrays of fixed size alias with arrays of unknown size.
1457     if (ta->size() != TypeInt::POS) {
1458       const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
1459       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,ta->klass(),false,Type::Offset(offset), ta->field_offset());
1460     }
1461     // Arrays of known objects become arrays of unknown objects.
1462     if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
1463       const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
1464       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,Type::Offset(offset), ta->field_offset());
1465     }
1466     if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
1467       const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
1468       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,Type::Offset(offset), ta->field_offset());
1469     }
1470     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
1471     // cannot be distinguished by bytecode alone.
1472     if (ta->elem() == TypeInt::BOOL) {
1473       const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
1474       ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
1475       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,Type::Offset(offset), ta->field_offset());
1476     }
1477     // During the 2nd round of IterGVN, NotNull castings are removed.
1478     // Make sure the Bottom and NotNull variants alias the same.
1479     // Also, make sure exact and non-exact variants alias the same.
1480     if (ptr == TypePtr::NotNull || ta->klass_is_exact() || ta->speculative() != NULL) {
1481       tj = ta = TypeAryPtr::make(TypePtr::BotPTR,ta->ary(),ta->klass(),false,Type::Offset(offset), ta->field_offset());
1482     }
1483   }
1484 
1485   // Oop pointers need some flattening
1486   const TypeInstPtr *to = tj->isa_instptr();
1487   if( to && _AliasLevel >= 2 && to != TypeOopPtr::BOTTOM ) {
1488     ciInstanceKlass *k = to->klass()->as_instance_klass();
1489     if( ptr == TypePtr::Constant ) {
1490       if (to->klass() != ciEnv::current()->Class_klass() ||
1491           offset < k->size_helper() * wordSize) {
1492         // No constant oop pointers (such as Strings); they alias with
1493         // unknown strings.
1494         assert(!is_known_inst, "not scalarizable allocation");
1495         tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,Type::Offset(offset));
1496       }
1497     } else if( is_known_inst ) {
1498       tj = to; // Keep NotNull and klass_is_exact for instance type
1499     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
1500       // During the 2nd round of IterGVN, NotNull castings are removed.
1501       // Make sure the Bottom and NotNull variants alias the same.
1502       // Also, make sure exact and non-exact variants alias the same.
1503       tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,Type::Offset(offset));
1504     }
1505     if (to->speculative() != NULL) {
1506       tj = to = TypeInstPtr::make(to->ptr(),to->klass(),to->klass_is_exact(),to->const_oop(),Type::Offset(to->offset()), to->instance_id());
1507     }
1508     // Canonicalize the holder of this field
1509     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
1510       // First handle header references such as a LoadKlassNode, even if the
1511       // object's klass is unloaded at compile time (4965979).
1512       if (!is_known_inst) { // Do it only for non-instance types
1513         tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, NULL, Type::Offset(offset));
1514       }
1515     } else if (offset < 0 || offset >= k->size_helper() * wordSize) {
1516       // Static fields are in the space above the normal instance
1517       // fields in the java.lang.Class instance.
1518       if (to->klass() != ciEnv::current()->Class_klass()) {
1519         to = NULL;
1520         tj = TypeOopPtr::BOTTOM;
1521         offset = tj->offset();
1522       }
1523     } else {
1524       ciInstanceKlass *canonical_holder = k->get_canonical_holder(offset);
1525       if (!k->equals(canonical_holder) || tj->offset() != offset) {
1526         if( is_known_inst ) {
1527           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, true, NULL, Type::Offset(offset), to->instance_id());
1528         } else {
1529           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, false, NULL, Type::Offset(offset));
1530         }
1531       }
1532     }
1533   }
1534 
1535   // Klass pointers to object array klasses need some flattening
1536   const TypeKlassPtr *tk = tj->isa_klassptr();
1537   if( tk ) {
1538     // If we are referencing a field within a Klass, we need
1539     // to assume the worst case of an Object.  Both exact and
1540     // inexact types must flatten to the same alias class so
1541     // use NotNull as the PTR.
1542     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
1543 
1544       tj = tk = TypeKlassPtr::make(TypePtr::NotNull,
1545                                    TypeKlassPtr::OBJECT->klass(),
1546                                    Type::Offset(offset));
1547     }
1548 
1549     ciKlass* klass = tk->klass();
1550     if (klass != NULL && klass->is_obj_array_klass()) {
1551       ciKlass* k = TypeAryPtr::OOPS->klass();
1552       if( !k || !k->is_loaded() )                  // Only fails for some -Xcomp runs
1553         k = TypeInstPtr::BOTTOM->klass();
1554       tj = tk = TypeKlassPtr::make(TypePtr::NotNull, k, Type::Offset(offset));
1555     }
1556 
1557     // Check for precise loads from the primary supertype array and force them
1558     // to the supertype cache alias index.  Check for generic array loads from
1559     // the primary supertype array and also force them to the supertype cache
1560     // alias index.  Since the same load can reach both, we need to merge
1561     // these 2 disparate memories into the same alias class.  Since the
1562     // primary supertype array is read-only, there's no chance of confusion
1563     // where we bypass an array load and an array store.
1564     int primary_supers_offset = in_bytes(Klass::primary_supers_offset());
1565     if (offset == Type::OffsetBot ||
1566         (offset >= primary_supers_offset &&
1567          offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
1568         offset == (int)in_bytes(Klass::secondary_super_cache_offset())) {
1569       offset = in_bytes(Klass::secondary_super_cache_offset());
1570       tj = tk = TypeKlassPtr::make(TypePtr::NotNull, tk->klass(), Type::Offset(offset));
1571     }
1572   }
1573 
1574   // Flatten all Raw pointers together.
1575   if (tj->base() == Type::RawPtr)
1576     tj = TypeRawPtr::BOTTOM;
1577 
1578   if (tj->base() == Type::AnyPtr)
1579     tj = TypePtr::BOTTOM;      // An error, which the caller must check for.
1580 
1581   // Flatten all to bottom for now
1582   switch( _AliasLevel ) {
1583   case 0:
1584     tj = TypePtr::BOTTOM;
1585     break;
1586   case 1:                       // Flatten to: oop, static, field or array
1587     switch (tj->base()) {
1588     //case Type::AryPtr: tj = TypeAryPtr::RANGE;    break;
1589     case Type::RawPtr:   tj = TypeRawPtr::BOTTOM;   break;
1590     case Type::AryPtr:   // do not distinguish arrays at all
1591     case Type::InstPtr:  tj = TypeInstPtr::BOTTOM;  break;
1592     case Type::KlassPtr: tj = TypeKlassPtr::OBJECT; break;
1593     case Type::AnyPtr:   tj = TypePtr::BOTTOM;      break;  // caller checks it
1594     default: ShouldNotReachHere();
1595     }
1596     break;
1597   case 2:                       // No collapsing at level 2; keep all splits
1598   case 3:                       // No collapsing at level 3; keep all splits
1599     break;
1600   default:
1601     Unimplemented();
1602   }
1603 
1604   offset = tj->offset();
1605   assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
1606 
1607   assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
1608           (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
1609           (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
1610           (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
1611           (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1612           (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1613           (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr)  ,
1614           "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
1615   assert( tj->ptr() != TypePtr::TopPTR &&
1616           tj->ptr() != TypePtr::AnyNull &&
1617           tj->ptr() != TypePtr::Null, "No imprecise addresses" );
1618 //    assert( tj->ptr() != TypePtr::Constant ||
1619 //            tj->base() == Type::RawPtr ||
1620 //            tj->base() == Type::KlassPtr, "No constant oop addresses" );
1621 
1622   return tj;
1623 }
1624 
1625 void Compile::AliasType::Init(int i, const TypePtr* at) {
1626   _index = i;
1627   _adr_type = at;
1628   _field = NULL;
1629   _element = NULL;
1630   _is_rewritable = true; // default
1631   const TypeOopPtr *atoop = (at != NULL) ? at->isa_oopptr() : NULL;
1632   if (atoop != NULL && atoop->is_known_instance()) {
1633     const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
1634     _general_index = Compile::current()->get_alias_index(gt);
1635   } else {
1636     _general_index = 0;
1637   }
1638 }
1639 
1640 BasicType Compile::AliasType::basic_type() const {
1641   if (element() != NULL) {
1642     const Type* element = adr_type()->is_aryptr()->elem();
1643     return element->isa_narrowoop() ? T_OBJECT : element->array_element_basic_type();
1644   } if (field() != NULL) {
1645     return field()->layout_type();
1646   } else {
1647     return T_ILLEGAL; // unknown
1648   }
1649 }
1650 
1651 //---------------------------------print_on------------------------------------
1652 #ifndef PRODUCT
1653 void Compile::AliasType::print_on(outputStream* st) {
1654   if (index() < 10)
1655         st->print("@ <%d> ", index());
1656   else  st->print("@ <%d>",  index());
1657   st->print(is_rewritable() ? "   " : " RO");
1658   int offset = adr_type()->offset();
1659   if (offset == Type::OffsetBot)
1660         st->print(" +any");
1661   else  st->print(" +%-3d", offset);
1662   st->print(" in ");
1663   adr_type()->dump_on(st);
1664   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
1665   if (field() != NULL && tjp) {
1666     if (tjp->klass()  != field()->holder() ||
1667         tjp->offset() != field()->offset_in_bytes()) {
1668       st->print(" != ");
1669       field()->print();
1670       st->print(" ***");
1671     }
1672   }
1673 }
1674 
1675 void print_alias_types() {
1676   Compile* C = Compile::current();
1677   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
1678   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
1679     C->alias_type(idx)->print_on(tty);
1680     tty->cr();
1681   }
1682 }
1683 #endif
1684 
1685 
1686 //----------------------------probe_alias_cache--------------------------------
1687 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
1688   intptr_t key = (intptr_t) adr_type;
1689   key ^= key >> logAliasCacheSize;
1690   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
1691 }
1692 
1693 
1694 //-----------------------------grow_alias_types--------------------------------
1695 void Compile::grow_alias_types() {
1696   const int old_ats  = _max_alias_types; // how many before?
1697   const int new_ats  = old_ats;          // how many more?
1698   const int grow_ats = old_ats+new_ats;  // how many now?
1699   _max_alias_types = grow_ats;
1700   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
1701   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
1702   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
1703   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
1704 }
1705 
1706 
1707 //--------------------------------find_alias_type------------------------------
1708 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field) {
1709   if (_AliasLevel == 0)
1710     return alias_type(AliasIdxBot);
1711 
1712   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1713   if (ace->_adr_type == adr_type) {
1714     return alias_type(ace->_index);
1715   }
1716 
1717   // Handle special cases.
1718   if (adr_type == NULL)             return alias_type(AliasIdxTop);
1719   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
1720 
1721   // Do it the slow way.
1722   const TypePtr* flat = flatten_alias_type(adr_type);
1723 
1724 #ifdef ASSERT
1725   {
1726     ResourceMark rm;
1727     assert(flat == flatten_alias_type(flat), "not idempotent: adr_type = %s; flat = %s => %s",
1728            Type::str(adr_type), Type::str(flat), Type::str(flatten_alias_type(flat)));
1729     assert(flat != TypePtr::BOTTOM, "cannot alias-analyze an untyped ptr: adr_type = %s",
1730            Type::str(adr_type));
1731     if (flat->isa_oopptr() && !flat->isa_klassptr()) {
1732       const TypeOopPtr* foop = flat->is_oopptr();
1733       // Scalarizable allocations have exact klass always.
1734       bool exact = !foop->klass_is_exact() || foop->is_known_instance();
1735       const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
1736       assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type: foop = %s; xoop = %s",
1737              Type::str(foop), Type::str(xoop));
1738     }
1739   }
1740 #endif
1741 
1742   int idx = AliasIdxTop;
1743   for (int i = 0; i < num_alias_types(); i++) {
1744     if (alias_type(i)->adr_type() == flat) {
1745       idx = i;
1746       break;
1747     }
1748   }
1749 
1750   if (idx == AliasIdxTop) {
1751     if (no_create)  return NULL;
1752     // Grow the array if necessary.
1753     if (_num_alias_types == _max_alias_types)  grow_alias_types();
1754     // Add a new alias type.
1755     idx = _num_alias_types++;
1756     _alias_types[idx]->Init(idx, flat);
1757     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
1758     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
1759     if (flat->isa_instptr()) {
1760       if (flat->offset() == java_lang_Class::klass_offset_in_bytes()
1761           && flat->is_instptr()->klass() == env()->Class_klass())
1762         alias_type(idx)->set_rewritable(false);
1763     }
1764     if (flat->isa_aryptr()) {
1765 #ifdef ASSERT
1766       const int header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1767       // (T_BYTE has the weakest alignment and size restrictions...)
1768       assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
1769 #endif
1770       if (flat->offset() == TypePtr::OffsetBot) {
1771         alias_type(idx)->set_element(flat->is_aryptr()->elem());
1772       }
1773     }
1774     if (flat->isa_klassptr()) {
1775       if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
1776         alias_type(idx)->set_rewritable(false);
1777       if (flat->offset() == in_bytes(Klass::modifier_flags_offset()))
1778         alias_type(idx)->set_rewritable(false);
1779       if (flat->offset() == in_bytes(Klass::access_flags_offset()))
1780         alias_type(idx)->set_rewritable(false);
1781       if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
1782         alias_type(idx)->set_rewritable(false);
1783     }
1784     // %%% (We would like to finalize JavaThread::threadObj_offset(),
1785     // but the base pointer type is not distinctive enough to identify
1786     // references into JavaThread.)
1787 
1788     // Check for final fields.
1789     const TypeInstPtr* tinst = flat->isa_instptr();
1790     const TypeValueTypePtr* vtptr = flat->isa_valuetypeptr();
1791     ciField* field = NULL;
1792     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
1793       if (tinst->const_oop() != NULL &&
1794           tinst->klass() == ciEnv::current()->Class_klass() &&
1795           tinst->offset() >= (tinst->klass()->as_instance_klass()->size_helper() * wordSize)) {
1796         // static field
1797         ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
1798         field = k->get_field_by_offset(tinst->offset(), true);
1799       } else {
1800         ciInstanceKlass *k = tinst->klass()->as_instance_klass();
1801         field = k->get_field_by_offset(tinst->offset(), false);
1802       }
1803     } else if (vtptr) {
1804       // Value type field
1805       ciValueKlass* vk = vtptr->klass()->as_value_klass();
1806       field = vk->get_field_by_offset(vtptr->offset(), false);
1807     }
1808     assert(field == NULL ||
1809            original_field == NULL ||
1810            (field->holder() == original_field->holder() &&
1811             field->offset() == original_field->offset() &&
1812             field->is_static() == original_field->is_static()), "wrong field?");
1813     // Set field() and is_rewritable() attributes.
1814     if (field != NULL)  alias_type(idx)->set_field(field);
1815   }
1816 
1817   // Fill the cache for next time.
1818   ace->_adr_type = adr_type;
1819   ace->_index    = idx;
1820   assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
1821 
1822   // Might as well try to fill the cache for the flattened version, too.
1823   AliasCacheEntry* face = probe_alias_cache(flat);
1824   if (face->_adr_type == NULL) {
1825     face->_adr_type = flat;
1826     face->_index    = idx;
1827     assert(alias_type(flat) == alias_type(idx), "flat type must work too");
1828   }
1829 
1830   return alias_type(idx);
1831 }
1832 
1833 
1834 Compile::AliasType* Compile::alias_type(ciField* field) {
1835   const TypeOopPtr* t;
1836   if (field->is_static())
1837     t = TypeInstPtr::make(field->holder()->java_mirror());
1838   else
1839     t = TypeOopPtr::make_from_klass_raw(field->holder());
1840   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);
1841   assert((field->is_final() || field->is_stable()) == !atp->is_rewritable(), "must get the rewritable bits correct");
1842   return atp;
1843 }
1844 
1845 
1846 //------------------------------have_alias_type--------------------------------
1847 bool Compile::have_alias_type(const TypePtr* adr_type) {
1848   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1849   if (ace->_adr_type == adr_type) {
1850     return true;
1851   }
1852 
1853   // Handle special cases.
1854   if (adr_type == NULL)             return true;
1855   if (adr_type == TypePtr::BOTTOM)  return true;
1856 
1857   return find_alias_type(adr_type, true, NULL) != NULL;
1858 }
1859 
1860 //-----------------------------must_alias--------------------------------------
1861 // True if all values of the given address type are in the given alias category.
1862 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
1863   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1864   if (adr_type == NULL)                 return true;  // NULL serves as TypePtr::TOP
1865   if (alias_idx == AliasIdxTop)         return false; // the empty category
1866   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
1867 
1868   // the only remaining possible overlap is identity
1869   int adr_idx = get_alias_index(adr_type);
1870   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1871   assert(adr_idx == alias_idx ||
1872          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
1873           && adr_type                       != TypeOopPtr::BOTTOM),
1874          "should not be testing for overlap with an unsafe pointer");
1875   return adr_idx == alias_idx;
1876 }
1877 
1878 //------------------------------can_alias--------------------------------------
1879 // True if any values of the given address type are in the given alias category.
1880 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
1881   if (alias_idx == AliasIdxTop)         return false; // the empty category
1882   if (adr_type == NULL)                 return false; // NULL serves as TypePtr::TOP
1883   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1884   if (adr_type->base() == Type::AnyPtr) return true;  // TypePtr::BOTTOM or its twins
1885 
1886   // the only remaining possible overlap is identity
1887   int adr_idx = get_alias_index(adr_type);
1888   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1889   return adr_idx == alias_idx;
1890 }
1891 
1892 
1893 
1894 //---------------------------pop_warm_call-------------------------------------
1895 WarmCallInfo* Compile::pop_warm_call() {
1896   WarmCallInfo* wci = _warm_calls;
1897   if (wci != NULL)  _warm_calls = wci->remove_from(wci);
1898   return wci;
1899 }
1900 
1901 //----------------------------Inline_Warm--------------------------------------
1902 int Compile::Inline_Warm() {
1903   // If there is room, try to inline some more warm call sites.
1904   // %%% Do a graph index compaction pass when we think we're out of space?
1905   if (!InlineWarmCalls)  return 0;
1906 
1907   int calls_made_hot = 0;
1908   int room_to_grow   = NodeCountInliningCutoff - unique();
1909   int amount_to_grow = MIN2(room_to_grow, (int)NodeCountInliningStep);
1910   int amount_grown   = 0;
1911   WarmCallInfo* call;
1912   while (amount_to_grow > 0 && (call = pop_warm_call()) != NULL) {
1913     int est_size = (int)call->size();
1914     if (est_size > (room_to_grow - amount_grown)) {
1915       // This one won't fit anyway.  Get rid of it.
1916       call->make_cold();
1917       continue;
1918     }
1919     call->make_hot();
1920     calls_made_hot++;
1921     amount_grown   += est_size;
1922     amount_to_grow -= est_size;
1923   }
1924 
1925   if (calls_made_hot > 0)  set_major_progress();
1926   return calls_made_hot;
1927 }
1928 
1929 
1930 //----------------------------Finish_Warm--------------------------------------
1931 void Compile::Finish_Warm() {
1932   if (!InlineWarmCalls)  return;
1933   if (failing())  return;
1934   if (warm_calls() == NULL)  return;
1935 
1936   // Clean up loose ends, if we are out of space for inlining.
1937   WarmCallInfo* call;
1938   while ((call = pop_warm_call()) != NULL) {
1939     call->make_cold();
1940   }
1941 }
1942 
1943 //---------------------cleanup_loop_predicates-----------------------
1944 // Remove the opaque nodes that protect the predicates so that all unused
1945 // checks and uncommon_traps will be eliminated from the ideal graph
1946 void Compile::cleanup_loop_predicates(PhaseIterGVN &igvn) {
1947   if (predicate_count()==0) return;
1948   for (int i = predicate_count(); i > 0; i--) {
1949     Node * n = predicate_opaque1_node(i-1);
1950     assert(n->Opcode() == Op_Opaque1, "must be");
1951     igvn.replace_node(n, n->in(1));
1952   }
1953   assert(predicate_count()==0, "should be clean!");
1954 }
1955 
1956 void Compile::add_range_check_cast(Node* n) {
1957   assert(n->isa_CastII()->has_range_check(), "CastII should have range check dependency");
1958   assert(!_range_check_casts->contains(n), "duplicate entry in range check casts");
1959   _range_check_casts->append(n);
1960 }
1961 
1962 // Remove all range check dependent CastIINodes.
1963 void Compile::remove_range_check_casts(PhaseIterGVN &igvn) {
1964   for (int i = range_check_cast_count(); i > 0; i--) {
1965     Node* cast = range_check_cast_node(i-1);
1966     assert(cast->isa_CastII()->has_range_check(), "CastII should have range check dependency");
1967     igvn.replace_node(cast, cast->in(1));
1968   }
1969   assert(range_check_cast_count() == 0, "should be empty");
1970 }
1971 
1972 void Compile::add_value_type_ptr(ValueTypePtrNode* n) {
1973   assert(can_add_value_type_ptr(), "too late");
1974   assert(!_value_type_ptr_nodes->contains(n), "duplicate entry");
1975   _value_type_ptr_nodes->append(n);
1976 }
1977 
1978 void Compile::process_value_type_ptr_nodes(PhaseIterGVN &igvn) {
1979   for (int i = value_type_ptr_count(); i > 0; i--) {
1980     ValueTypePtrNode* vtptr = value_type_ptr(i-1);
1981     // once all inlining is over otherwise debug info can get
1982     // inconsistent
1983     vtptr->make_scalar_in_safepoints(igvn.C->root(), &igvn);
1984     igvn.replace_node(vtptr, vtptr->get_oop());
1985   }
1986   assert(value_type_ptr_count() == 0, "should be empty");
1987   _value_type_ptr_nodes = NULL;
1988   igvn.optimize();
1989 }
1990 
1991 // StringOpts and late inlining of string methods
1992 void Compile::inline_string_calls(bool parse_time) {
1993   {
1994     // remove useless nodes to make the usage analysis simpler
1995     ResourceMark rm;
1996     PhaseRemoveUseless pru(initial_gvn(), for_igvn());
1997   }
1998 
1999   {
2000     ResourceMark rm;
2001     print_method(PHASE_BEFORE_STRINGOPTS, 3);
2002     PhaseStringOpts pso(initial_gvn(), for_igvn());
2003     print_method(PHASE_AFTER_STRINGOPTS, 3);
2004   }
2005 
2006   // now inline anything that we skipped the first time around
2007   if (!parse_time) {
2008     _late_inlines_pos = _late_inlines.length();
2009   }
2010 
2011   while (_string_late_inlines.length() > 0) {
2012     CallGenerator* cg = _string_late_inlines.pop();
2013     cg->do_late_inline();
2014     if (failing())  return;
2015   }
2016   _string_late_inlines.trunc_to(0);
2017 }
2018 
2019 // Late inlining of boxing methods
2020 void Compile::inline_boxing_calls(PhaseIterGVN& igvn) {
2021   if (_boxing_late_inlines.length() > 0) {
2022     assert(has_boxed_value(), "inconsistent");
2023 
2024     PhaseGVN* gvn = initial_gvn();
2025     set_inlining_incrementally(true);
2026 
2027     assert( igvn._worklist.size() == 0, "should be done with igvn" );
2028     for_igvn()->clear();
2029     gvn->replace_with(&igvn);
2030 
2031     _late_inlines_pos = _late_inlines.length();
2032 
2033     while (_boxing_late_inlines.length() > 0) {
2034       CallGenerator* cg = _boxing_late_inlines.pop();
2035       cg->do_late_inline();
2036       if (failing())  return;
2037     }
2038     _boxing_late_inlines.trunc_to(0);
2039 
2040     {
2041       ResourceMark rm;
2042       PhaseRemoveUseless pru(gvn, for_igvn());
2043     }
2044 
2045     igvn = PhaseIterGVN(gvn);
2046     igvn.optimize();
2047 
2048     set_inlining_progress(false);
2049     set_inlining_incrementally(false);
2050   }
2051 }
2052 
2053 void Compile::inline_incrementally_one(PhaseIterGVN& igvn) {
2054   assert(IncrementalInline, "incremental inlining should be on");
2055   PhaseGVN* gvn = initial_gvn();
2056 
2057   set_inlining_progress(false);
2058   for_igvn()->clear();
2059   gvn->replace_with(&igvn);
2060 
2061   {
2062     TracePhase tp("incrementalInline_inline", &timers[_t_incrInline_inline]);
2063     int i = 0;
2064     for (; i <_late_inlines.length() && !inlining_progress(); i++) {
2065       CallGenerator* cg = _late_inlines.at(i);
2066       _late_inlines_pos = i+1;
2067       cg->do_late_inline();
2068       if (failing())  return;
2069     }
2070     int j = 0;
2071     for (; i < _late_inlines.length(); i++, j++) {
2072       _late_inlines.at_put(j, _late_inlines.at(i));
2073     }
2074     _late_inlines.trunc_to(j);
2075   }
2076 
2077   {
2078     TracePhase tp("incrementalInline_pru", &timers[_t_incrInline_pru]);
2079     ResourceMark rm;
2080     PhaseRemoveUseless pru(gvn, for_igvn());
2081   }
2082 
2083   {
2084     TracePhase tp("incrementalInline_igvn", &timers[_t_incrInline_igvn]);
2085     igvn = PhaseIterGVN(gvn);
2086   }
2087 }
2088 
2089 // Perform incremental inlining until bound on number of live nodes is reached
2090 void Compile::inline_incrementally(PhaseIterGVN& igvn) {
2091   TracePhase tp("incrementalInline", &timers[_t_incrInline]);
2092 
2093   PhaseGVN* gvn = initial_gvn();
2094 
2095   set_inlining_incrementally(true);
2096   set_inlining_progress(true);
2097   uint low_live_nodes = 0;
2098 
2099   while(inlining_progress() && _late_inlines.length() > 0) {
2100 
2101     if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2102       if (low_live_nodes < (uint)LiveNodeCountInliningCutoff * 8 / 10) {
2103         TracePhase tp("incrementalInline_ideal", &timers[_t_incrInline_ideal]);
2104         // PhaseIdealLoop is expensive so we only try it once we are
2105         // out of live nodes and we only try it again if the previous
2106         // helped got the number of nodes down significantly
2107         PhaseIdealLoop ideal_loop( igvn, false, true );
2108         if (failing())  return;
2109         low_live_nodes = live_nodes();
2110         _major_progress = true;
2111       }
2112 
2113       if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2114         break;
2115       }
2116     }
2117 
2118     inline_incrementally_one(igvn);
2119 
2120     if (failing())  return;
2121 
2122     {
2123       TracePhase tp("incrementalInline_igvn", &timers[_t_incrInline_igvn]);
2124       igvn.optimize();
2125     }
2126 
2127     if (failing())  return;
2128   }
2129 
2130   assert( igvn._worklist.size() == 0, "should be done with igvn" );
2131 
2132   if (_string_late_inlines.length() > 0) {
2133     assert(has_stringbuilder(), "inconsistent");
2134     for_igvn()->clear();
2135     initial_gvn()->replace_with(&igvn);
2136 
2137     inline_string_calls(false);
2138 
2139     if (failing())  return;
2140 
2141     {
2142       TracePhase tp("incrementalInline_pru", &timers[_t_incrInline_pru]);
2143       ResourceMark rm;
2144       PhaseRemoveUseless pru(initial_gvn(), for_igvn());
2145     }
2146 
2147     {
2148       TracePhase tp("incrementalInline_igvn", &timers[_t_incrInline_igvn]);
2149       igvn = PhaseIterGVN(gvn);
2150       igvn.optimize();
2151     }
2152   }
2153 
2154   set_inlining_incrementally(false);
2155 }
2156 
2157 
2158 //------------------------------Optimize---------------------------------------
2159 // Given a graph, optimize it.
2160 void Compile::Optimize() {
2161   TracePhase tp("optimizer", &timers[_t_optimizer]);
2162 
2163 #ifndef PRODUCT
2164   if (_directive->BreakAtCompileOption) {
2165     BREAKPOINT;
2166   }
2167 
2168 #endif
2169 
2170   ResourceMark rm;
2171   int          loop_opts_cnt;
2172 
2173   print_inlining_reinit();
2174 
2175   NOT_PRODUCT( verify_graph_edges(); )
2176 
2177   print_method(PHASE_AFTER_PARSING);
2178 
2179  {
2180   // Iterative Global Value Numbering, including ideal transforms
2181   // Initialize IterGVN with types and values from parse-time GVN
2182   PhaseIterGVN igvn(initial_gvn());
2183 #ifdef ASSERT
2184   _modified_nodes = new (comp_arena()) Unique_Node_List(comp_arena());
2185 #endif
2186   {
2187     TracePhase tp("iterGVN", &timers[_t_iterGVN]);
2188     igvn.optimize();
2189   }
2190 
2191   print_method(PHASE_ITER_GVN1, 2);
2192 
2193   if (failing())  return;
2194 
2195   inline_incrementally(igvn);
2196 
2197   print_method(PHASE_INCREMENTAL_INLINE, 2);
2198 
2199   if (failing())  return;
2200 
2201   if (eliminate_boxing()) {
2202     // Inline valueOf() methods now.
2203     inline_boxing_calls(igvn);
2204 
2205     if (AlwaysIncrementalInline) {
2206       inline_incrementally(igvn);
2207     }
2208 
2209     print_method(PHASE_INCREMENTAL_BOXING_INLINE, 2);
2210 
2211     if (failing())  return;
2212   }
2213 
2214   // Remove the speculative part of types and clean up the graph from
2215   // the extra CastPP nodes whose only purpose is to carry them. Do
2216   // that early so that optimizations are not disrupted by the extra
2217   // CastPP nodes.
2218   remove_speculative_types(igvn);
2219 
2220   // No more new expensive nodes will be added to the list from here
2221   // so keep only the actual candidates for optimizations.
2222   cleanup_expensive_nodes(igvn);
2223 
2224   if (!failing() && RenumberLiveNodes && live_nodes() + NodeLimitFudgeFactor < unique()) {
2225     Compile::TracePhase tp("", &timers[_t_renumberLive]);
2226     initial_gvn()->replace_with(&igvn);
2227     for_igvn()->clear();
2228     Unique_Node_List new_worklist(C->comp_arena());
2229     {
2230       ResourceMark rm;
2231       PhaseRenumberLive prl = PhaseRenumberLive(initial_gvn(), for_igvn(), &new_worklist);
2232     }
2233     set_for_igvn(&new_worklist);
2234     igvn = PhaseIterGVN(initial_gvn());
2235     igvn.optimize();
2236   }
2237 
2238   if (value_type_ptr_count() > 0) {
2239     process_value_type_ptr_nodes(igvn);
2240   }
2241 
2242   // Perform escape analysis
2243   if (_do_escape_analysis && ConnectionGraph::has_candidates(this)) {
2244     if (has_loops()) {
2245       // Cleanup graph (remove dead nodes).
2246       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2247       PhaseIdealLoop ideal_loop( igvn, false, true );
2248       if (major_progress()) print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
2249       if (failing())  return;
2250     }
2251     ConnectionGraph::do_analysis(this, &igvn);
2252 
2253     if (failing())  return;
2254 
2255     // Optimize out fields loads from scalar replaceable allocations.
2256     igvn.optimize();
2257     print_method(PHASE_ITER_GVN_AFTER_EA, 2);
2258 
2259     if (failing())  return;
2260 
2261     if (congraph() != NULL && macro_count() > 0) {
2262       TracePhase tp("macroEliminate", &timers[_t_macroEliminate]);
2263       PhaseMacroExpand mexp(igvn);
2264       mexp.eliminate_macro_nodes();
2265       igvn.set_delay_transform(false);
2266 
2267       igvn.optimize();
2268       print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
2269 
2270       if (failing())  return;
2271     }
2272   }
2273 
2274   // Loop transforms on the ideal graph.  Range Check Elimination,
2275   // peeling, unrolling, etc.
2276 
2277   // Set loop opts counter
2278   loop_opts_cnt = num_loop_opts();
2279   if((loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
2280     {
2281       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2282       PhaseIdealLoop ideal_loop( igvn, true );
2283       loop_opts_cnt--;
2284       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP1, 2);
2285       if (failing())  return;
2286     }
2287     // Loop opts pass if partial peeling occurred in previous pass
2288     if(PartialPeelLoop && major_progress() && (loop_opts_cnt > 0)) {
2289       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2290       PhaseIdealLoop ideal_loop( igvn, false );
2291       loop_opts_cnt--;
2292       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP2, 2);
2293       if (failing())  return;
2294     }
2295     // Loop opts pass for loop-unrolling before CCP
2296     if(major_progress() && (loop_opts_cnt > 0)) {
2297       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2298       PhaseIdealLoop ideal_loop( igvn, false );
2299       loop_opts_cnt--;
2300       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP3, 2);
2301     }
2302     if (!failing()) {
2303       // Verify that last round of loop opts produced a valid graph
2304       TracePhase tp("idealLoopVerify", &timers[_t_idealLoopVerify]);
2305       PhaseIdealLoop::verify(igvn);
2306     }
2307   }
2308   if (failing())  return;
2309 
2310   // Conditional Constant Propagation;
2311   PhaseCCP ccp( &igvn );
2312   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
2313   {
2314     TracePhase tp("ccp", &timers[_t_ccp]);
2315     ccp.do_transform();
2316   }
2317   print_method(PHASE_CPP1, 2);
2318 
2319   assert( true, "Break here to ccp.dump_old2new_map()");
2320 
2321   // Iterative Global Value Numbering, including ideal transforms
2322   {
2323     TracePhase tp("iterGVN2", &timers[_t_iterGVN2]);
2324     igvn = ccp;
2325     igvn.optimize();
2326   }
2327 
2328   print_method(PHASE_ITER_GVN2, 2);
2329 
2330   if (failing())  return;
2331 
2332   // Loop transforms on the ideal graph.  Range Check Elimination,
2333   // peeling, unrolling, etc.
2334   if(loop_opts_cnt > 0) {
2335     debug_only( int cnt = 0; );
2336     while(major_progress() && (loop_opts_cnt > 0)) {
2337       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2338       assert( cnt++ < 40, "infinite cycle in loop optimization" );
2339       PhaseIdealLoop ideal_loop( igvn, true);
2340       loop_opts_cnt--;
2341       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
2342       if (failing())  return;
2343     }
2344   }
2345   // Ensure that major progress is now clear
2346   C->clear_major_progress();
2347 
2348   {
2349     // Verify that all previous optimizations produced a valid graph
2350     // at least to this point, even if no loop optimizations were done.
2351     TracePhase tp("idealLoopVerify", &timers[_t_idealLoopVerify]);
2352     PhaseIdealLoop::verify(igvn);
2353   }
2354 
2355   if (range_check_cast_count() > 0) {
2356     // No more loop optimizations. Remove all range check dependent CastIINodes.
2357     C->remove_range_check_casts(igvn);
2358     igvn.optimize();
2359   }
2360 
2361   {
2362     TracePhase tp("macroExpand", &timers[_t_macroExpand]);
2363     PhaseMacroExpand  mex(igvn);
2364     if (mex.expand_macro_nodes()) {
2365       assert(failing(), "must bail out w/ explicit message");
2366       return;
2367     }
2368   }
2369 
2370   DEBUG_ONLY( _modified_nodes = NULL; )
2371  } // (End scope of igvn; run destructor if necessary for asserts.)
2372 
2373  process_print_inlining();
2374  // A method with only infinite loops has no edges entering loops from root
2375  {
2376    TracePhase tp("graphReshape", &timers[_t_graphReshaping]);
2377    if (final_graph_reshaping()) {
2378      assert(failing(), "must bail out w/ explicit message");
2379      return;
2380    }
2381  }
2382 
2383  print_method(PHASE_OPTIMIZE_FINISHED, 2);
2384 }
2385 
2386 // Fixme remove
2387 static void check_for_value_node(Node &n, void* C) {
2388   if (n.is_ValueType()) {
2389 #ifdef ASSERT
2390     ((Compile*)C)->method()->print_short_name();
2391     tty->print_cr("");
2392     n.dump(-1);
2393     assert(false, "Unable to match ValueTypeNode");
2394 #endif
2395     ((Compile*)C)->record_failure("Unable to match ValueTypeNode");
2396   }
2397 }
2398 
2399 //------------------------------Code_Gen---------------------------------------
2400 // Given a graph, generate code for it
2401 void Compile::Code_Gen() {
2402   // FIXME remove
2403   root()->walk(Node::nop, check_for_value_node, this);
2404 
2405   if (failing()) {
2406     return;
2407   }
2408 
2409   // Perform instruction selection.  You might think we could reclaim Matcher
2410   // memory PDQ, but actually the Matcher is used in generating spill code.
2411   // Internals of the Matcher (including some VectorSets) must remain live
2412   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
2413   // set a bit in reclaimed memory.
2414 
2415   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2416   // nodes.  Mapping is only valid at the root of each matched subtree.
2417   NOT_PRODUCT( verify_graph_edges(); )
2418 
2419   Matcher matcher;
2420   _matcher = &matcher;
2421   {
2422     TracePhase tp("matcher", &timers[_t_matcher]);
2423     matcher.match();
2424   }
2425   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2426   // nodes.  Mapping is only valid at the root of each matched subtree.
2427   NOT_PRODUCT( verify_graph_edges(); )
2428 
2429   // If you have too many nodes, or if matching has failed, bail out
2430   check_node_count(0, "out of nodes matching instructions");
2431   if (failing()) {
2432     return;
2433   }
2434 
2435   // Build a proper-looking CFG
2436   PhaseCFG cfg(node_arena(), root(), matcher);
2437   _cfg = &cfg;
2438   {
2439     TracePhase tp("scheduler", &timers[_t_scheduler]);
2440     bool success = cfg.do_global_code_motion();
2441     if (!success) {
2442       return;
2443     }
2444 
2445     print_method(PHASE_GLOBAL_CODE_MOTION, 2);
2446     NOT_PRODUCT( verify_graph_edges(); )
2447     debug_only( cfg.verify(); )
2448   }
2449 
2450   PhaseChaitin regalloc(unique(), cfg, matcher, false);
2451   _regalloc = &regalloc;
2452   {
2453     TracePhase tp("regalloc", &timers[_t_registerAllocation]);
2454     // Perform register allocation.  After Chaitin, use-def chains are
2455     // no longer accurate (at spill code) and so must be ignored.
2456     // Node->LRG->reg mappings are still accurate.
2457     _regalloc->Register_Allocate();
2458 
2459     // Bail out if the allocator builds too many nodes
2460     if (failing()) {
2461       return;
2462     }
2463   }
2464 
2465   // Prior to register allocation we kept empty basic blocks in case the
2466   // the allocator needed a place to spill.  After register allocation we
2467   // are not adding any new instructions.  If any basic block is empty, we
2468   // can now safely remove it.
2469   {
2470     TracePhase tp("blockOrdering", &timers[_t_blockOrdering]);
2471     cfg.remove_empty_blocks();
2472     if (do_freq_based_layout()) {
2473       PhaseBlockLayout layout(cfg);
2474     } else {
2475       cfg.set_loop_alignment();
2476     }
2477     cfg.fixup_flow();
2478   }
2479 
2480   // Apply peephole optimizations
2481   if( OptoPeephole ) {
2482     TracePhase tp("peephole", &timers[_t_peephole]);
2483     PhasePeephole peep( _regalloc, cfg);
2484     peep.do_transform();
2485   }
2486 
2487   // Do late expand if CPU requires this.
2488   if (Matcher::require_postalloc_expand) {
2489     TracePhase tp("postalloc_expand", &timers[_t_postalloc_expand]);
2490     cfg.postalloc_expand(_regalloc);
2491   }
2492 
2493   // Convert Nodes to instruction bits in a buffer
2494   {
2495     TraceTime tp("output", &timers[_t_output], CITime);
2496     Output();
2497   }
2498 
2499   print_method(PHASE_FINAL_CODE);
2500 
2501   // He's dead, Jim.
2502   _cfg     = (PhaseCFG*)0xdeadbeef;
2503   _regalloc = (PhaseChaitin*)0xdeadbeef;
2504 }
2505 
2506 
2507 //------------------------------dump_asm---------------------------------------
2508 // Dump formatted assembly
2509 #ifndef PRODUCT
2510 void Compile::dump_asm(int *pcs, uint pc_limit) {
2511   bool cut_short = false;
2512   tty->print_cr("#");
2513   tty->print("#  ");  _tf->dump();  tty->cr();
2514   tty->print_cr("#");
2515 
2516   // For all blocks
2517   int pc = 0x0;                 // Program counter
2518   char starts_bundle = ' ';
2519   _regalloc->dump_frame();
2520 
2521   Node *n = NULL;
2522   for (uint i = 0; i < _cfg->number_of_blocks(); i++) {
2523     if (VMThread::should_terminate()) {
2524       cut_short = true;
2525       break;
2526     }
2527     Block* block = _cfg->get_block(i);
2528     if (block->is_connector() && !Verbose) {
2529       continue;
2530     }
2531     n = block->head();
2532     if (pcs && n->_idx < pc_limit) {
2533       tty->print("%3.3x   ", pcs[n->_idx]);
2534     } else {
2535       tty->print("      ");
2536     }
2537     block->dump_head(_cfg);
2538     if (block->is_connector()) {
2539       tty->print_cr("        # Empty connector block");
2540     } else if (block->num_preds() == 2 && block->pred(1)->is_CatchProj() && block->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
2541       tty->print_cr("        # Block is sole successor of call");
2542     }
2543 
2544     // For all instructions
2545     Node *delay = NULL;
2546     for (uint j = 0; j < block->number_of_nodes(); j++) {
2547       if (VMThread::should_terminate()) {
2548         cut_short = true;
2549         break;
2550       }
2551       n = block->get_node(j);
2552       if (valid_bundle_info(n)) {
2553         Bundle* bundle = node_bundling(n);
2554         if (bundle->used_in_unconditional_delay()) {
2555           delay = n;
2556           continue;
2557         }
2558         if (bundle->starts_bundle()) {
2559           starts_bundle = '+';
2560         }
2561       }
2562 
2563       if (WizardMode) {
2564         n->dump();
2565       }
2566 
2567       if( !n->is_Region() &&    // Dont print in the Assembly
2568           !n->is_Phi() &&       // a few noisely useless nodes
2569           !n->is_Proj() &&
2570           !n->is_MachTemp() &&
2571           !n->is_SafePointScalarObject() &&
2572           !n->is_Catch() &&     // Would be nice to print exception table targets
2573           !n->is_MergeMem() &&  // Not very interesting
2574           !n->is_top() &&       // Debug info table constants
2575           !(n->is_Con() && !n->is_Mach())// Debug info table constants
2576           ) {
2577         if (pcs && n->_idx < pc_limit)
2578           tty->print("%3.3x", pcs[n->_idx]);
2579         else
2580           tty->print("   ");
2581         tty->print(" %c ", starts_bundle);
2582         starts_bundle = ' ';
2583         tty->print("\t");
2584         n->format(_regalloc, tty);
2585         tty->cr();
2586       }
2587 
2588       // If we have an instruction with a delay slot, and have seen a delay,
2589       // then back up and print it
2590       if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
2591         assert(delay != NULL, "no unconditional delay instruction");
2592         if (WizardMode) delay->dump();
2593 
2594         if (node_bundling(delay)->starts_bundle())
2595           starts_bundle = '+';
2596         if (pcs && n->_idx < pc_limit)
2597           tty->print("%3.3x", pcs[n->_idx]);
2598         else
2599           tty->print("   ");
2600         tty->print(" %c ", starts_bundle);
2601         starts_bundle = ' ';
2602         tty->print("\t");
2603         delay->format(_regalloc, tty);
2604         tty->cr();
2605         delay = NULL;
2606       }
2607 
2608       // Dump the exception table as well
2609       if( n->is_Catch() && (Verbose || WizardMode) ) {
2610         // Print the exception table for this offset
2611         _handler_table.print_subtable_for(pc);
2612       }
2613     }
2614 
2615     if (pcs && n->_idx < pc_limit)
2616       tty->print_cr("%3.3x", pcs[n->_idx]);
2617     else
2618       tty->cr();
2619 
2620     assert(cut_short || delay == NULL, "no unconditional delay branch");
2621 
2622   } // End of per-block dump
2623   tty->cr();
2624 
2625   if (cut_short)  tty->print_cr("*** disassembly is cut short ***");
2626 }
2627 #endif
2628 
2629 //------------------------------Final_Reshape_Counts---------------------------
2630 // This class defines counters to help identify when a method
2631 // may/must be executed using hardware with only 24-bit precision.
2632 struct Final_Reshape_Counts : public StackObj {
2633   int  _call_count;             // count non-inlined 'common' calls
2634   int  _float_count;            // count float ops requiring 24-bit precision
2635   int  _double_count;           // count double ops requiring more precision
2636   int  _java_call_count;        // count non-inlined 'java' calls
2637   int  _inner_loop_count;       // count loops which need alignment
2638   VectorSet _visited;           // Visitation flags
2639   Node_List _tests;             // Set of IfNodes & PCTableNodes
2640 
2641   Final_Reshape_Counts() :
2642     _call_count(0), _float_count(0), _double_count(0),
2643     _java_call_count(0), _inner_loop_count(0),
2644     _visited( Thread::current()->resource_area() ) { }
2645 
2646   void inc_call_count  () { _call_count  ++; }
2647   void inc_float_count () { _float_count ++; }
2648   void inc_double_count() { _double_count++; }
2649   void inc_java_call_count() { _java_call_count++; }
2650   void inc_inner_loop_count() { _inner_loop_count++; }
2651 
2652   int  get_call_count  () const { return _call_count  ; }
2653   int  get_float_count () const { return _float_count ; }
2654   int  get_double_count() const { return _double_count; }
2655   int  get_java_call_count() const { return _java_call_count; }
2656   int  get_inner_loop_count() const { return _inner_loop_count; }
2657 };
2658 
2659 #ifdef ASSERT
2660 static bool oop_offset_is_sane(const TypeInstPtr* tp) {
2661   ciInstanceKlass *k = tp->klass()->as_instance_klass();
2662   // Make sure the offset goes inside the instance layout.
2663   return k->contains_field_offset(tp->offset());
2664   // Note that OffsetBot and OffsetTop are very negative.
2665 }
2666 #endif
2667 
2668 // Eliminate trivially redundant StoreCMs and accumulate their
2669 // precedence edges.
2670 void Compile::eliminate_redundant_card_marks(Node* n) {
2671   assert(n->Opcode() == Op_StoreCM, "expected StoreCM");
2672   if (n->in(MemNode::Address)->outcnt() > 1) {
2673     // There are multiple users of the same address so it might be
2674     // possible to eliminate some of the StoreCMs
2675     Node* mem = n->in(MemNode::Memory);
2676     Node* adr = n->in(MemNode::Address);
2677     Node* val = n->in(MemNode::ValueIn);
2678     Node* prev = n;
2679     bool done = false;
2680     // Walk the chain of StoreCMs eliminating ones that match.  As
2681     // long as it's a chain of single users then the optimization is
2682     // safe.  Eliminating partially redundant StoreCMs would require
2683     // cloning copies down the other paths.
2684     while (mem->Opcode() == Op_StoreCM && mem->outcnt() == 1 && !done) {
2685       if (adr == mem->in(MemNode::Address) &&
2686           val == mem->in(MemNode::ValueIn)) {
2687         // redundant StoreCM
2688         if (mem->req() > MemNode::OopStore) {
2689           // Hasn't been processed by this code yet.
2690           n->add_prec(mem->in(MemNode::OopStore));
2691         } else {
2692           // Already converted to precedence edge
2693           for (uint i = mem->req(); i < mem->len(); i++) {
2694             // Accumulate any precedence edges
2695             if (mem->in(i) != NULL) {
2696               n->add_prec(mem->in(i));
2697             }
2698           }
2699           // Everything above this point has been processed.
2700           done = true;
2701         }
2702         // Eliminate the previous StoreCM
2703         prev->set_req(MemNode::Memory, mem->in(MemNode::Memory));
2704         assert(mem->outcnt() == 0, "should be dead");
2705         mem->disconnect_inputs(NULL, this);
2706       } else {
2707         prev = mem;
2708       }
2709       mem = prev->in(MemNode::Memory);
2710     }
2711   }
2712 }
2713 
2714 
2715 //------------------------------final_graph_reshaping_impl----------------------
2716 // Implement items 1-5 from final_graph_reshaping below.
2717 void Compile::final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &frc) {
2718 
2719   if ( n->outcnt() == 0 ) return; // dead node
2720   uint nop = n->Opcode();
2721 
2722   // Check for 2-input instruction with "last use" on right input.
2723   // Swap to left input.  Implements item (2).
2724   if( n->req() == 3 &&          // two-input instruction
2725       n->in(1)->outcnt() > 1 && // left use is NOT a last use
2726       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
2727       n->in(2)->outcnt() == 1 &&// right use IS a last use
2728       !n->in(2)->is_Con() ) {   // right use is not a constant
2729     // Check for commutative opcode
2730     switch( nop ) {
2731     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddL:
2732     case Op_MaxI:  case Op_MinI:
2733     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulL:
2734     case Op_AndL:  case Op_XorL:  case Op_OrL:
2735     case Op_AndI:  case Op_XorI:  case Op_OrI: {
2736       // Move "last use" input to left by swapping inputs
2737       n->swap_edges(1, 2);
2738       break;
2739     }
2740     default:
2741       break;
2742     }
2743   }
2744 
2745 #ifdef ASSERT
2746   if( n->is_Mem() ) {
2747     int alias_idx = get_alias_index(n->as_Mem()->adr_type());
2748     assert( n->in(0) != NULL || alias_idx != Compile::AliasIdxRaw ||
2749             // oop will be recorded in oop map if load crosses safepoint
2750             n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
2751                              LoadNode::is_immutable_value(n->in(MemNode::Address))),
2752             "raw memory operations should have control edge");
2753   }
2754 #endif
2755   // Count FPU ops and common calls, implements item (3)
2756   switch( nop ) {
2757   // Count all float operations that may use FPU
2758   case Op_AddF:
2759   case Op_SubF:
2760   case Op_MulF:
2761   case Op_DivF:
2762   case Op_NegF:
2763   case Op_ModF:
2764   case Op_ConvI2F:
2765   case Op_ConF:
2766   case Op_CmpF:
2767   case Op_CmpF3:
2768   // case Op_ConvL2F: // longs are split into 32-bit halves
2769     frc.inc_float_count();
2770     break;
2771 
2772   case Op_ConvF2D:
2773   case Op_ConvD2F:
2774     frc.inc_float_count();
2775     frc.inc_double_count();
2776     break;
2777 
2778   // Count all double operations that may use FPU
2779   case Op_AddD:
2780   case Op_SubD:
2781   case Op_MulD:
2782   case Op_DivD:
2783   case Op_NegD:
2784   case Op_ModD:
2785   case Op_ConvI2D:
2786   case Op_ConvD2I:
2787   // case Op_ConvL2D: // handled by leaf call
2788   // case Op_ConvD2L: // handled by leaf call
2789   case Op_ConD:
2790   case Op_CmpD:
2791   case Op_CmpD3:
2792     frc.inc_double_count();
2793     break;
2794   case Op_Opaque1:              // Remove Opaque Nodes before matching
2795   case Op_Opaque2:              // Remove Opaque Nodes before matching
2796   case Op_Opaque3:
2797     n->subsume_by(n->in(1), this);
2798     break;
2799   case Op_CallStaticJava:
2800   case Op_CallJava:
2801   case Op_CallDynamicJava:
2802     frc.inc_java_call_count(); // Count java call site;
2803   case Op_CallRuntime:
2804   case Op_CallLeaf:
2805   case Op_CallLeafNoFP: {
2806     assert( n->is_Call(), "" );
2807     CallNode *call = n->as_Call();
2808     // Count call sites where the FP mode bit would have to be flipped.
2809     // Do not count uncommon runtime calls:
2810     // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
2811     // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
2812     if( !call->is_CallStaticJava() || !call->as_CallStaticJava()->_name ) {
2813       frc.inc_call_count();   // Count the call site
2814     } else {                  // See if uncommon argument is shared
2815       Node *n = call->in(TypeFunc::Parms);
2816       int nop = n->Opcode();
2817       // Clone shared simple arguments to uncommon calls, item (1).
2818       if( n->outcnt() > 1 &&
2819           !n->is_Proj() &&
2820           nop != Op_CreateEx &&
2821           nop != Op_CheckCastPP &&
2822           nop != Op_DecodeN &&
2823           nop != Op_DecodeNKlass &&
2824           !n->is_Mem() ) {
2825         Node *x = n->clone();
2826         call->set_req( TypeFunc::Parms, x );
2827       }
2828     }
2829     break;
2830   }
2831 
2832   case Op_StoreD:
2833   case Op_LoadD:
2834   case Op_LoadD_unaligned:
2835     frc.inc_double_count();
2836     goto handle_mem;
2837   case Op_StoreF:
2838   case Op_LoadF:
2839     frc.inc_float_count();
2840     goto handle_mem;
2841 
2842   case Op_StoreCM:
2843     {
2844       // Convert OopStore dependence into precedence edge
2845       Node* prec = n->in(MemNode::OopStore);
2846       n->del_req(MemNode::OopStore);
2847       n->add_prec(prec);
2848       eliminate_redundant_card_marks(n);
2849     }
2850 
2851     // fall through
2852 
2853   case Op_StoreB:
2854   case Op_StoreC:
2855   case Op_StorePConditional:
2856   case Op_StoreI:
2857   case Op_StoreL:
2858   case Op_StoreIConditional:
2859   case Op_StoreLConditional:
2860   case Op_CompareAndSwapB:
2861   case Op_CompareAndSwapS:
2862   case Op_CompareAndSwapI:
2863   case Op_CompareAndSwapL:
2864   case Op_CompareAndSwapP:
2865   case Op_CompareAndSwapN:
2866   case Op_WeakCompareAndSwapB:
2867   case Op_WeakCompareAndSwapS:
2868   case Op_WeakCompareAndSwapI:
2869   case Op_WeakCompareAndSwapL:
2870   case Op_WeakCompareAndSwapP:
2871   case Op_WeakCompareAndSwapN:
2872   case Op_CompareAndExchangeB:
2873   case Op_CompareAndExchangeS:
2874   case Op_CompareAndExchangeI:
2875   case Op_CompareAndExchangeL:
2876   case Op_CompareAndExchangeP:
2877   case Op_CompareAndExchangeN:
2878   case Op_GetAndAddS:
2879   case Op_GetAndAddB:
2880   case Op_GetAndAddI:
2881   case Op_GetAndAddL:
2882   case Op_GetAndSetS:
2883   case Op_GetAndSetB:
2884   case Op_GetAndSetI:
2885   case Op_GetAndSetL:
2886   case Op_GetAndSetP:
2887   case Op_GetAndSetN:
2888   case Op_StoreP:
2889   case Op_StoreN:
2890   case Op_StoreNKlass:
2891   case Op_LoadB:
2892   case Op_LoadUB:
2893   case Op_LoadUS:
2894   case Op_LoadI:
2895   case Op_LoadKlass:
2896   case Op_LoadNKlass:
2897   case Op_LoadL:
2898   case Op_LoadL_unaligned:
2899   case Op_LoadPLocked:
2900   case Op_LoadP:
2901   case Op_LoadN:
2902   case Op_LoadRange:
2903   case Op_LoadS: {
2904   handle_mem:
2905 #ifdef ASSERT
2906     if( VerifyOptoOopOffsets ) {
2907       assert( n->is_Mem(), "" );
2908       MemNode *mem  = (MemNode*)n;
2909       // Check to see if address types have grounded out somehow.
2910       const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
2911       assert( !tp || oop_offset_is_sane(tp), "" );
2912     }
2913 #endif
2914     break;
2915   }
2916 
2917   case Op_AddP: {               // Assert sane base pointers
2918     Node *addp = n->in(AddPNode::Address);
2919     assert( !addp->is_AddP() ||
2920             addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
2921             addp->in(AddPNode::Base) == n->in(AddPNode::Base),
2922             "Base pointers must match (addp %u)", addp->_idx );
2923 #ifdef _LP64
2924     if ((UseCompressedOops || UseCompressedClassPointers) &&
2925         addp->Opcode() == Op_ConP &&
2926         addp == n->in(AddPNode::Base) &&
2927         n->in(AddPNode::Offset)->is_Con()) {
2928       // If the transformation of ConP to ConN+DecodeN is beneficial depends
2929       // on the platform and on the compressed oops mode.
2930       // Use addressing with narrow klass to load with offset on x86.
2931       // Some platforms can use the constant pool to load ConP.
2932       // Do this transformation here since IGVN will convert ConN back to ConP.
2933       const Type* t = addp->bottom_type();
2934       bool is_oop   = t->isa_oopptr() != NULL;
2935       bool is_klass = t->isa_klassptr() != NULL;
2936 
2937       if ((is_oop   && Matcher::const_oop_prefer_decode()  ) ||
2938           (is_klass && Matcher::const_klass_prefer_decode())) {
2939         Node* nn = NULL;
2940 
2941         int op = is_oop ? Op_ConN : Op_ConNKlass;
2942 
2943         // Look for existing ConN node of the same exact type.
2944         Node* r  = root();
2945         uint cnt = r->outcnt();
2946         for (uint i = 0; i < cnt; i++) {
2947           Node* m = r->raw_out(i);
2948           if (m!= NULL && m->Opcode() == op &&
2949               m->bottom_type()->make_ptr() == t) {
2950             nn = m;
2951             break;
2952           }
2953         }
2954         if (nn != NULL) {
2955           // Decode a narrow oop to match address
2956           // [R12 + narrow_oop_reg<<3 + offset]
2957           if (is_oop) {
2958             nn = new DecodeNNode(nn, t);
2959           } else {
2960             nn = new DecodeNKlassNode(nn, t);
2961           }
2962           // Check for succeeding AddP which uses the same Base.
2963           // Otherwise we will run into the assertion above when visiting that guy.
2964           for (uint i = 0; i < n->outcnt(); ++i) {
2965             Node *out_i = n->raw_out(i);
2966             if (out_i && out_i->is_AddP() && out_i->in(AddPNode::Base) == addp) {
2967               out_i->set_req(AddPNode::Base, nn);
2968 #ifdef ASSERT
2969               for (uint j = 0; j < out_i->outcnt(); ++j) {
2970                 Node *out_j = out_i->raw_out(j);
2971                 assert(out_j == NULL || !out_j->is_AddP() || out_j->in(AddPNode::Base) != addp,
2972                        "more than 2 AddP nodes in a chain (out_j %u)", out_j->_idx);
2973               }
2974 #endif
2975             }
2976           }
2977           n->set_req(AddPNode::Base, nn);
2978           n->set_req(AddPNode::Address, nn);
2979           if (addp->outcnt() == 0) {
2980             addp->disconnect_inputs(NULL, this);
2981           }
2982         }
2983       }
2984     }
2985 #endif
2986     // platform dependent reshaping of the address expression
2987     reshape_address(n->as_AddP());
2988     break;
2989   }
2990 
2991   case Op_CastPP: {
2992     // Remove CastPP nodes to gain more freedom during scheduling but
2993     // keep the dependency they encode as control or precedence edges
2994     // (if control is set already) on memory operations. Some CastPP
2995     // nodes don't have a control (don't carry a dependency): skip
2996     // those.
2997     if (n->in(0) != NULL) {
2998       ResourceMark rm;
2999       Unique_Node_List wq;
3000       wq.push(n);
3001       for (uint next = 0; next < wq.size(); ++next) {
3002         Node *m = wq.at(next);
3003         for (DUIterator_Fast imax, i = m->fast_outs(imax); i < imax; i++) {
3004           Node* use = m->fast_out(i);
3005           if (use->is_Mem() || use->is_EncodeNarrowPtr()) {
3006             use->ensure_control_or_add_prec(n->in(0));
3007           } else {
3008             switch(use->Opcode()) {
3009             case Op_AddP:
3010             case Op_DecodeN:
3011             case Op_DecodeNKlass:
3012             case Op_CheckCastPP:
3013             case Op_CastPP:
3014               wq.push(use);
3015               break;
3016             }
3017           }
3018         }
3019       }
3020     }
3021     const bool is_LP64 = LP64_ONLY(true) NOT_LP64(false);
3022     if (is_LP64 && n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
3023       Node* in1 = n->in(1);
3024       const Type* t = n->bottom_type();
3025       Node* new_in1 = in1->clone();
3026       new_in1->as_DecodeN()->set_type(t);
3027 
3028       if (!Matcher::narrow_oop_use_complex_address()) {
3029         //
3030         // x86, ARM and friends can handle 2 adds in addressing mode
3031         // and Matcher can fold a DecodeN node into address by using
3032         // a narrow oop directly and do implicit NULL check in address:
3033         //
3034         // [R12 + narrow_oop_reg<<3 + offset]
3035         // NullCheck narrow_oop_reg
3036         //
3037         // On other platforms (Sparc) we have to keep new DecodeN node and
3038         // use it to do implicit NULL check in address:
3039         //
3040         // decode_not_null narrow_oop_reg, base_reg
3041         // [base_reg + offset]
3042         // NullCheck base_reg
3043         //
3044         // Pin the new DecodeN node to non-null path on these platform (Sparc)
3045         // to keep the information to which NULL check the new DecodeN node
3046         // corresponds to use it as value in implicit_null_check().
3047         //
3048         new_in1->set_req(0, n->in(0));
3049       }
3050 
3051       n->subsume_by(new_in1, this);
3052       if (in1->outcnt() == 0) {
3053         in1->disconnect_inputs(NULL, this);
3054       }
3055     } else {
3056       n->subsume_by(n->in(1), this);
3057       if (n->outcnt() == 0) {
3058         n->disconnect_inputs(NULL, this);
3059       }
3060     }
3061     break;
3062   }
3063 #ifdef _LP64
3064   case Op_CmpP:
3065     // Do this transformation here to preserve CmpPNode::sub() and
3066     // other TypePtr related Ideal optimizations (for example, ptr nullness).
3067     if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
3068       Node* in1 = n->in(1);
3069       Node* in2 = n->in(2);
3070       if (!in1->is_DecodeNarrowPtr()) {
3071         in2 = in1;
3072         in1 = n->in(2);
3073       }
3074       assert(in1->is_DecodeNarrowPtr(), "sanity");
3075 
3076       Node* new_in2 = NULL;
3077       if (in2->is_DecodeNarrowPtr()) {
3078         assert(in2->Opcode() == in1->Opcode(), "must be same node type");
3079         new_in2 = in2->in(1);
3080       } else if (in2->Opcode() == Op_ConP) {
3081         const Type* t = in2->bottom_type();
3082         if (t == TypePtr::NULL_PTR) {
3083           assert(in1->is_DecodeN(), "compare klass to null?");
3084           // Don't convert CmpP null check into CmpN if compressed
3085           // oops implicit null check is not generated.
3086           // This will allow to generate normal oop implicit null check.
3087           if (Matcher::gen_narrow_oop_implicit_null_checks())
3088             new_in2 = ConNode::make(TypeNarrowOop::NULL_PTR);
3089           //
3090           // This transformation together with CastPP transformation above
3091           // will generated code for implicit NULL checks for compressed oops.
3092           //
3093           // The original code after Optimize()
3094           //
3095           //    LoadN memory, narrow_oop_reg
3096           //    decode narrow_oop_reg, base_reg
3097           //    CmpP base_reg, NULL
3098           //    CastPP base_reg // NotNull
3099           //    Load [base_reg + offset], val_reg
3100           //
3101           // after these transformations will be
3102           //
3103           //    LoadN memory, narrow_oop_reg
3104           //    CmpN narrow_oop_reg, NULL
3105           //    decode_not_null narrow_oop_reg, base_reg
3106           //    Load [base_reg + offset], val_reg
3107           //
3108           // and the uncommon path (== NULL) will use narrow_oop_reg directly
3109           // since narrow oops can be used in debug info now (see the code in
3110           // final_graph_reshaping_walk()).
3111           //
3112           // At the end the code will be matched to
3113           // on x86:
3114           //
3115           //    Load_narrow_oop memory, narrow_oop_reg
3116           //    Load [R12 + narrow_oop_reg<<3 + offset], val_reg
3117           //    NullCheck narrow_oop_reg
3118           //
3119           // and on sparc:
3120           //
3121           //    Load_narrow_oop memory, narrow_oop_reg
3122           //    decode_not_null narrow_oop_reg, base_reg
3123           //    Load [base_reg + offset], val_reg
3124           //    NullCheck base_reg
3125           //
3126         } else if (t->isa_oopptr()) {
3127           new_in2 = ConNode::make(t->make_narrowoop());
3128         } else if (t->isa_klassptr()) {
3129           new_in2 = ConNode::make(t->make_narrowklass());
3130         }
3131       }
3132       if (new_in2 != NULL) {
3133         Node* cmpN = new CmpNNode(in1->in(1), new_in2);
3134         n->subsume_by(cmpN, this);
3135         if (in1->outcnt() == 0) {
3136           in1->disconnect_inputs(NULL, this);
3137         }
3138         if (in2->outcnt() == 0) {
3139           in2->disconnect_inputs(NULL, this);
3140         }
3141       }
3142     }
3143     break;
3144 
3145   case Op_DecodeN:
3146   case Op_DecodeNKlass:
3147     assert(!n->in(1)->is_EncodeNarrowPtr(), "should be optimized out");
3148     // DecodeN could be pinned when it can't be fold into
3149     // an address expression, see the code for Op_CastPP above.
3150     assert(n->in(0) == NULL || (UseCompressedOops && !Matcher::narrow_oop_use_complex_address()), "no control");
3151     break;
3152 
3153   case Op_EncodeP:
3154   case Op_EncodePKlass: {
3155     Node* in1 = n->in(1);
3156     if (in1->is_DecodeNarrowPtr()) {
3157       n->subsume_by(in1->in(1), this);
3158     } else if (in1->Opcode() == Op_ConP) {
3159       const Type* t = in1->bottom_type();
3160       if (t == TypePtr::NULL_PTR) {
3161         assert(t->isa_oopptr(), "null klass?");
3162         n->subsume_by(ConNode::make(TypeNarrowOop::NULL_PTR), this);
3163       } else if (t->isa_oopptr()) {
3164         n->subsume_by(ConNode::make(t->make_narrowoop()), this);
3165       } else if (t->isa_klassptr()) {
3166         n->subsume_by(ConNode::make(t->make_narrowklass()), this);
3167       }
3168     }
3169     if (in1->outcnt() == 0) {
3170       in1->disconnect_inputs(NULL, this);
3171     }
3172     break;
3173   }
3174 
3175   case Op_Proj: {
3176     if (OptimizeStringConcat) {
3177       ProjNode* p = n->as_Proj();
3178       if (p->_is_io_use) {
3179         // Separate projections were used for the exception path which
3180         // are normally removed by a late inline.  If it wasn't inlined
3181         // then they will hang around and should just be replaced with
3182         // the original one.
3183         Node* proj = NULL;
3184         // Replace with just one
3185         for (SimpleDUIterator i(p->in(0)); i.has_next(); i.next()) {
3186           Node *use = i.get();
3187           if (use->is_Proj() && p != use && use->as_Proj()->_con == p->_con) {
3188             proj = use;
3189             break;
3190           }
3191         }
3192         assert(proj != NULL, "must be found");
3193         p->subsume_by(proj, this);
3194       }
3195     }
3196     break;
3197   }
3198 
3199   case Op_Phi:
3200     if (n->as_Phi()->bottom_type()->isa_narrowoop() || n->as_Phi()->bottom_type()->isa_narrowklass()) {
3201       // The EncodeP optimization may create Phi with the same edges
3202       // for all paths. It is not handled well by Register Allocator.
3203       Node* unique_in = n->in(1);
3204       assert(unique_in != NULL, "");
3205       uint cnt = n->req();
3206       for (uint i = 2; i < cnt; i++) {
3207         Node* m = n->in(i);
3208         assert(m != NULL, "");
3209         if (unique_in != m)
3210           unique_in = NULL;
3211       }
3212       if (unique_in != NULL) {
3213         n->subsume_by(unique_in, this);
3214       }
3215     }
3216     break;
3217 
3218 #endif
3219 
3220 #ifdef ASSERT
3221   case Op_CastII:
3222     // Verify that all range check dependent CastII nodes were removed.
3223     if (n->isa_CastII()->has_range_check()) {
3224       n->dump(3);
3225       assert(false, "Range check dependent CastII node was not removed");
3226     }
3227     break;
3228 #endif
3229 
3230   case Op_ModI:
3231     if (UseDivMod) {
3232       // Check if a%b and a/b both exist
3233       Node* d = n->find_similar(Op_DivI);
3234       if (d) {
3235         // Replace them with a fused divmod if supported
3236         if (Matcher::has_match_rule(Op_DivModI)) {
3237           DivModINode* divmod = DivModINode::make(n);
3238           d->subsume_by(divmod->div_proj(), this);
3239           n->subsume_by(divmod->mod_proj(), this);
3240         } else {
3241           // replace a%b with a-((a/b)*b)
3242           Node* mult = new MulINode(d, d->in(2));
3243           Node* sub  = new SubINode(d->in(1), mult);
3244           n->subsume_by(sub, this);
3245         }
3246       }
3247     }
3248     break;
3249 
3250   case Op_ModL:
3251     if (UseDivMod) {
3252       // Check if a%b and a/b both exist
3253       Node* d = n->find_similar(Op_DivL);
3254       if (d) {
3255         // Replace them with a fused divmod if supported
3256         if (Matcher::has_match_rule(Op_DivModL)) {
3257           DivModLNode* divmod = DivModLNode::make(n);
3258           d->subsume_by(divmod->div_proj(), this);
3259           n->subsume_by(divmod->mod_proj(), this);
3260         } else {
3261           // replace a%b with a-((a/b)*b)
3262           Node* mult = new MulLNode(d, d->in(2));
3263           Node* sub  = new SubLNode(d->in(1), mult);
3264           n->subsume_by(sub, this);
3265         }
3266       }
3267     }
3268     break;
3269 
3270   case Op_LoadVector:
3271   case Op_StoreVector:
3272     break;
3273 
3274   case Op_AddReductionVI:
3275   case Op_AddReductionVL:
3276   case Op_AddReductionVF:
3277   case Op_AddReductionVD:
3278   case Op_MulReductionVI:
3279   case Op_MulReductionVL:
3280   case Op_MulReductionVF:
3281   case Op_MulReductionVD:
3282     break;
3283 
3284   case Op_PackB:
3285   case Op_PackS:
3286   case Op_PackI:
3287   case Op_PackF:
3288   case Op_PackL:
3289   case Op_PackD:
3290     if (n->req()-1 > 2) {
3291       // Replace many operand PackNodes with a binary tree for matching
3292       PackNode* p = (PackNode*) n;
3293       Node* btp = p->binary_tree_pack(1, n->req());
3294       n->subsume_by(btp, this);
3295     }
3296     break;
3297   case Op_Loop:
3298   case Op_CountedLoop:
3299     if (n->as_Loop()->is_inner_loop()) {
3300       frc.inc_inner_loop_count();
3301     }
3302     break;
3303   case Op_LShiftI:
3304   case Op_RShiftI:
3305   case Op_URShiftI:
3306   case Op_LShiftL:
3307   case Op_RShiftL:
3308   case Op_URShiftL:
3309     if (Matcher::need_masked_shift_count) {
3310       // The cpu's shift instructions don't restrict the count to the
3311       // lower 5/6 bits. We need to do the masking ourselves.
3312       Node* in2 = n->in(2);
3313       juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
3314       const TypeInt* t = in2->find_int_type();
3315       if (t != NULL && t->is_con()) {
3316         juint shift = t->get_con();
3317         if (shift > mask) { // Unsigned cmp
3318           n->set_req(2, ConNode::make(TypeInt::make(shift & mask)));
3319         }
3320       } else {
3321         if (t == NULL || t->_lo < 0 || t->_hi > (int)mask) {
3322           Node* shift = new AndINode(in2, ConNode::make(TypeInt::make(mask)));
3323           n->set_req(2, shift);
3324         }
3325       }
3326       if (in2->outcnt() == 0) { // Remove dead node
3327         in2->disconnect_inputs(NULL, this);
3328       }
3329     }
3330     break;
3331   case Op_MemBarStoreStore:
3332   case Op_MemBarRelease:
3333     // Break the link with AllocateNode: it is no longer useful and
3334     // confuses register allocation.
3335     if (n->req() > MemBarNode::Precedent) {
3336       n->set_req(MemBarNode::Precedent, top());
3337     }
3338     break;
3339   case Op_RangeCheck: {
3340     RangeCheckNode* rc = n->as_RangeCheck();
3341     Node* iff = new IfNode(rc->in(0), rc->in(1), rc->_prob, rc->_fcnt);
3342     n->subsume_by(iff, this);
3343     frc._tests.push(iff);
3344     break;
3345   }
3346   case Op_ConvI2L: {
3347     if (!Matcher::convi2l_type_required) {
3348       // Code generation on some platforms doesn't need accurate
3349       // ConvI2L types. Widening the type can help remove redundant
3350       // address computations.
3351       n->as_Type()->set_type(TypeLong::INT);
3352       ResourceMark rm;
3353       Node_List wq;
3354       wq.push(n);
3355       for (uint next = 0; next < wq.size(); next++) {
3356         Node *m = wq.at(next);
3357 
3358         for(;;) {
3359           // Loop over all nodes with identical inputs edges as m
3360           Node* k = m->find_similar(m->Opcode());
3361           if (k == NULL) {
3362             break;
3363           }
3364           // Push their uses so we get a chance to remove node made
3365           // redundant
3366           for (DUIterator_Fast imax, i = k->fast_outs(imax); i < imax; i++) {
3367             Node* u = k->fast_out(i);
3368             assert(!wq.contains(u), "shouldn't process one node several times");
3369             if (u->Opcode() == Op_LShiftL ||
3370                 u->Opcode() == Op_AddL ||
3371                 u->Opcode() == Op_SubL ||
3372                 u->Opcode() == Op_AddP) {
3373               wq.push(u);
3374             }
3375           }
3376           // Replace all nodes with identical edges as m with m
3377           k->subsume_by(m, this);
3378         }
3379       }
3380     }
3381     break;
3382   }
3383   case Op_ValueType: {
3384     ValueTypeNode* vt = n->as_ValueType();
3385     vt->make_scalar_in_safepoints(root(), NULL);
3386     if (vt->outcnt() == 0) {
3387       vt->disconnect_inputs(NULL, this);
3388     }
3389     break;
3390   }
3391   case Op_ValueTypePtr: {
3392     ShouldNotReachHere();
3393     break;
3394   }
3395   default:
3396     assert( !n->is_Call(), "" );
3397     assert( !n->is_Mem(), "" );
3398     assert( nop != Op_ProfileBoolean, "should be eliminated during IGVN");
3399     break;
3400   }
3401 
3402   // Collect CFG split points
3403   if (n->is_MultiBranch() && !n->is_RangeCheck()) {
3404     frc._tests.push(n);
3405   }
3406 }
3407 
3408 //------------------------------final_graph_reshaping_walk---------------------
3409 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
3410 // requires that the walk visits a node's inputs before visiting the node.
3411 void Compile::final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Reshape_Counts &frc ) {
3412   ResourceArea *area = Thread::current()->resource_area();
3413   Unique_Node_List sfpt(area);
3414 
3415   frc._visited.set(root->_idx); // first, mark node as visited
3416   uint cnt = root->req();
3417   Node *n = root;
3418   uint  i = 0;
3419   while (true) {
3420     if (i < cnt) {
3421       // Place all non-visited non-null inputs onto stack
3422       Node* m = n->in(i);
3423       ++i;
3424       if (m != NULL && !frc._visited.test_set(m->_idx)) {
3425         if (m->is_SafePoint() && m->as_SafePoint()->jvms() != NULL) {
3426           // compute worst case interpreter size in case of a deoptimization
3427           update_interpreter_frame_size(m->as_SafePoint()->jvms()->interpreter_frame_size());
3428 
3429           sfpt.push(m);
3430         }
3431         cnt = m->req();
3432         nstack.push(n, i); // put on stack parent and next input's index
3433         n = m;
3434         i = 0;
3435       }
3436     } else {
3437       // Now do post-visit work
3438       final_graph_reshaping_impl( n, frc );
3439       if (nstack.is_empty())
3440         break;             // finished
3441       n = nstack.node();   // Get node from stack
3442       cnt = n->req();
3443       i = nstack.index();
3444       nstack.pop();        // Shift to the next node on stack
3445     }
3446   }
3447 
3448   // Skip next transformation if compressed oops are not used.
3449   if ((UseCompressedOops && !Matcher::gen_narrow_oop_implicit_null_checks()) ||
3450       (!UseCompressedOops && !UseCompressedClassPointers))
3451     return;
3452 
3453   // Go over safepoints nodes to skip DecodeN/DecodeNKlass nodes for debug edges.
3454   // It could be done for an uncommon traps or any safepoints/calls
3455   // if the DecodeN/DecodeNKlass node is referenced only in a debug info.
3456   while (sfpt.size() > 0) {
3457     n = sfpt.pop();
3458     JVMState *jvms = n->as_SafePoint()->jvms();
3459     assert(jvms != NULL, "sanity");
3460     int start = jvms->debug_start();
3461     int end   = n->req();
3462     bool is_uncommon = (n->is_CallStaticJava() &&
3463                         n->as_CallStaticJava()->uncommon_trap_request() != 0);
3464     for (int j = start; j < end; j++) {
3465       Node* in = n->in(j);
3466       if (in->is_DecodeNarrowPtr()) {
3467         bool safe_to_skip = true;
3468         if (!is_uncommon ) {
3469           // Is it safe to skip?
3470           for (uint i = 0; i < in->outcnt(); i++) {
3471             Node* u = in->raw_out(i);
3472             if (!u->is_SafePoint() ||
3473                  u->is_Call() && u->as_Call()->has_non_debug_use(n)) {
3474               safe_to_skip = false;
3475             }
3476           }
3477         }
3478         if (safe_to_skip) {
3479           n->set_req(j, in->in(1));
3480         }
3481         if (in->outcnt() == 0) {
3482           in->disconnect_inputs(NULL, this);
3483         }
3484       }
3485     }
3486   }
3487 }
3488 
3489 //------------------------------final_graph_reshaping--------------------------
3490 // Final Graph Reshaping.
3491 //
3492 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
3493 //     and not commoned up and forced early.  Must come after regular
3494 //     optimizations to avoid GVN undoing the cloning.  Clone constant
3495 //     inputs to Loop Phis; these will be split by the allocator anyways.
3496 //     Remove Opaque nodes.
3497 // (2) Move last-uses by commutative operations to the left input to encourage
3498 //     Intel update-in-place two-address operations and better register usage
3499 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
3500 //     calls canonicalizing them back.
3501 // (3) Count the number of double-precision FP ops, single-precision FP ops
3502 //     and call sites.  On Intel, we can get correct rounding either by
3503 //     forcing singles to memory (requires extra stores and loads after each
3504 //     FP bytecode) or we can set a rounding mode bit (requires setting and
3505 //     clearing the mode bit around call sites).  The mode bit is only used
3506 //     if the relative frequency of single FP ops to calls is low enough.
3507 //     This is a key transform for SPEC mpeg_audio.
3508 // (4) Detect infinite loops; blobs of code reachable from above but not
3509 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
3510 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
3511 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
3512 //     Detection is by looking for IfNodes where only 1 projection is
3513 //     reachable from below or CatchNodes missing some targets.
3514 // (5) Assert for insane oop offsets in debug mode.
3515 
3516 bool Compile::final_graph_reshaping() {
3517   // an infinite loop may have been eliminated by the optimizer,
3518   // in which case the graph will be empty.
3519   if (root()->req() == 1) {
3520     record_method_not_compilable("trivial infinite loop");
3521     return true;
3522   }
3523 
3524   // Expensive nodes have their control input set to prevent the GVN
3525   // from freely commoning them. There's no GVN beyond this point so
3526   // no need to keep the control input. We want the expensive nodes to
3527   // be freely moved to the least frequent code path by gcm.
3528   assert(OptimizeExpensiveOps || expensive_count() == 0, "optimization off but list non empty?");
3529   for (int i = 0; i < expensive_count(); i++) {
3530     _expensive_nodes->at(i)->set_req(0, NULL);
3531   }
3532 
3533   Final_Reshape_Counts frc;
3534 
3535   // Visit everybody reachable!
3536   // Allocate stack of size C->live_nodes()/2 to avoid frequent realloc
3537   Node_Stack nstack(live_nodes() >> 1);
3538   final_graph_reshaping_walk(nstack, root(), frc);
3539 
3540   // Check for unreachable (from below) code (i.e., infinite loops).
3541   for( uint i = 0; i < frc._tests.size(); i++ ) {
3542     MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
3543     // Get number of CFG targets.
3544     // Note that PCTables include exception targets after calls.
3545     uint required_outcnt = n->required_outcnt();
3546     if (n->outcnt() != required_outcnt) {
3547       // Check for a few special cases.  Rethrow Nodes never take the
3548       // 'fall-thru' path, so expected kids is 1 less.
3549       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
3550         if (n->in(0)->in(0)->is_Call()) {
3551           CallNode *call = n->in(0)->in(0)->as_Call();
3552           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
3553             required_outcnt--;      // Rethrow always has 1 less kid
3554           } else if (call->req() > TypeFunc::Parms &&
3555                      call->is_CallDynamicJava()) {
3556             // Check for null receiver. In such case, the optimizer has
3557             // detected that the virtual call will always result in a null
3558             // pointer exception. The fall-through projection of this CatchNode
3559             // will not be populated.
3560             Node *arg0 = call->in(TypeFunc::Parms);
3561             if (arg0->is_Type() &&
3562                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
3563               required_outcnt--;
3564             }
3565           } else if (call->entry_point() == OptoRuntime::new_array_Java() &&
3566                      call->req() > TypeFunc::Parms+1 &&
3567                      call->is_CallStaticJava()) {
3568             // Check for negative array length. In such case, the optimizer has
3569             // detected that the allocation attempt will always result in an
3570             // exception. There is no fall-through projection of this CatchNode .
3571             Node *arg1 = call->in(TypeFunc::Parms+1);
3572             if (arg1->is_Type() &&
3573                 arg1->as_Type()->type()->join(TypeInt::POS)->empty()) {
3574               required_outcnt--;
3575             }
3576           }
3577         }
3578       }
3579       // Recheck with a better notion of 'required_outcnt'
3580       if (n->outcnt() != required_outcnt) {
3581         assert(false, "malformed control flow");
3582         record_method_not_compilable("malformed control flow");
3583         return true;            // Not all targets reachable!
3584       }
3585     }
3586     // Check that I actually visited all kids.  Unreached kids
3587     // must be infinite loops.
3588     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
3589       if (!frc._visited.test(n->fast_out(j)->_idx)) {
3590         record_method_not_compilable("infinite loop");
3591         assert(false, "infinite loop");
3592         return true;            // Found unvisited kid; must be unreach
3593       }
3594   }
3595 
3596   // If original bytecodes contained a mixture of floats and doubles
3597   // check if the optimizer has made it homogenous, item (3).
3598   if( Use24BitFPMode && Use24BitFP && UseSSE == 0 &&
3599       frc.get_float_count() > 32 &&
3600       frc.get_double_count() == 0 &&
3601       (10 * frc.get_call_count() < frc.get_float_count()) ) {
3602     set_24_bit_selection_and_mode( false,  true );
3603   }
3604 
3605   set_java_calls(frc.get_java_call_count());
3606   set_inner_loops(frc.get_inner_loop_count());
3607 
3608   // No infinite loops, no reason to bail out.
3609   return false;
3610 }
3611 
3612 //-----------------------------too_many_traps----------------------------------
3613 // Report if there are too many traps at the current method and bci.
3614 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
3615 bool Compile::too_many_traps(ciMethod* method,
3616                              int bci,
3617                              Deoptimization::DeoptReason reason) {
3618   ciMethodData* md = method->method_data();
3619   if (md->is_empty()) {
3620     // Assume the trap has not occurred, or that it occurred only
3621     // because of a transient condition during start-up in the interpreter.
3622     return false;
3623   }
3624   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
3625   if (md->has_trap_at(bci, m, reason) != 0) {
3626     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
3627     // Also, if there are multiple reasons, or if there is no per-BCI record,
3628     // assume the worst.
3629     if (log())
3630       log()->elem("observe trap='%s' count='%d'",
3631                   Deoptimization::trap_reason_name(reason),
3632                   md->trap_count(reason));
3633     return true;
3634   } else {
3635     // Ignore method/bci and see if there have been too many globally.
3636     return too_many_traps(reason, md);
3637   }
3638 }
3639 
3640 // Less-accurate variant which does not require a method and bci.
3641 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
3642                              ciMethodData* logmd) {
3643   if (trap_count(reason) >= Deoptimization::per_method_trap_limit(reason)) {
3644     // Too many traps globally.
3645     // Note that we use cumulative trap_count, not just md->trap_count.
3646     if (log()) {
3647       int mcount = (logmd == NULL)? -1: (int)logmd->trap_count(reason);
3648       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
3649                   Deoptimization::trap_reason_name(reason),
3650                   mcount, trap_count(reason));
3651     }
3652     return true;
3653   } else {
3654     // The coast is clear.
3655     return false;
3656   }
3657 }
3658 
3659 //--------------------------too_many_recompiles--------------------------------
3660 // Report if there are too many recompiles at the current method and bci.
3661 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
3662 // Is not eager to return true, since this will cause the compiler to use
3663 // Action_none for a trap point, to avoid too many recompilations.
3664 bool Compile::too_many_recompiles(ciMethod* method,
3665                                   int bci,
3666                                   Deoptimization::DeoptReason reason) {
3667   ciMethodData* md = method->method_data();
3668   if (md->is_empty()) {
3669     // Assume the trap has not occurred, or that it occurred only
3670     // because of a transient condition during start-up in the interpreter.
3671     return false;
3672   }
3673   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
3674   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
3675   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
3676   Deoptimization::DeoptReason per_bc_reason
3677     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
3678   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
3679   if ((per_bc_reason == Deoptimization::Reason_none
3680        || md->has_trap_at(bci, m, reason) != 0)
3681       // The trap frequency measure we care about is the recompile count:
3682       && md->trap_recompiled_at(bci, m)
3683       && md->overflow_recompile_count() >= bc_cutoff) {
3684     // Do not emit a trap here if it has already caused recompilations.
3685     // Also, if there are multiple reasons, or if there is no per-BCI record,
3686     // assume the worst.
3687     if (log())
3688       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
3689                   Deoptimization::trap_reason_name(reason),
3690                   md->trap_count(reason),
3691                   md->overflow_recompile_count());
3692     return true;
3693   } else if (trap_count(reason) != 0
3694              && decompile_count() >= m_cutoff) {
3695     // Too many recompiles globally, and we have seen this sort of trap.
3696     // Use cumulative decompile_count, not just md->decompile_count.
3697     if (log())
3698       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
3699                   Deoptimization::trap_reason_name(reason),
3700                   md->trap_count(reason), trap_count(reason),
3701                   md->decompile_count(), decompile_count());
3702     return true;
3703   } else {
3704     // The coast is clear.
3705     return false;
3706   }
3707 }
3708 
3709 // Compute when not to trap. Used by matching trap based nodes and
3710 // NullCheck optimization.
3711 void Compile::set_allowed_deopt_reasons() {
3712   _allowed_reasons = 0;
3713   if (is_method_compilation()) {
3714     for (int rs = (int)Deoptimization::Reason_none+1; rs < Compile::trapHistLength; rs++) {
3715       assert(rs < BitsPerInt, "recode bit map");
3716       if (!too_many_traps((Deoptimization::DeoptReason) rs)) {
3717         _allowed_reasons |= nth_bit(rs);
3718       }
3719     }
3720   }
3721 }
3722 
3723 #ifndef PRODUCT
3724 //------------------------------verify_graph_edges---------------------------
3725 // Walk the Graph and verify that there is a one-to-one correspondence
3726 // between Use-Def edges and Def-Use edges in the graph.
3727 void Compile::verify_graph_edges(bool no_dead_code) {
3728   if (VerifyGraphEdges) {
3729     ResourceArea *area = Thread::current()->resource_area();
3730     Unique_Node_List visited(area);
3731     // Call recursive graph walk to check edges
3732     _root->verify_edges(visited);
3733     if (no_dead_code) {
3734       // Now make sure that no visited node is used by an unvisited node.
3735       bool dead_nodes = false;
3736       Unique_Node_List checked(area);
3737       while (visited.size() > 0) {
3738         Node* n = visited.pop();
3739         checked.push(n);
3740         for (uint i = 0; i < n->outcnt(); i++) {
3741           Node* use = n->raw_out(i);
3742           if (checked.member(use))  continue;  // already checked
3743           if (visited.member(use))  continue;  // already in the graph
3744           if (use->is_Con())        continue;  // a dead ConNode is OK
3745           // At this point, we have found a dead node which is DU-reachable.
3746           if (!dead_nodes) {
3747             tty->print_cr("*** Dead nodes reachable via DU edges:");
3748             dead_nodes = true;
3749           }
3750           use->dump(2);
3751           tty->print_cr("---");
3752           checked.push(use);  // No repeats; pretend it is now checked.
3753         }
3754       }
3755       assert(!dead_nodes, "using nodes must be reachable from root");
3756     }
3757   }
3758 }
3759 
3760 // Verify GC barriers consistency
3761 // Currently supported:
3762 // - G1 pre-barriers (see GraphKit::g1_write_barrier_pre())
3763 void Compile::verify_barriers() {
3764   if (UseG1GC) {
3765     // Verify G1 pre-barriers
3766     const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() + SATBMarkQueue::byte_offset_of_active());
3767 
3768     ResourceArea *area = Thread::current()->resource_area();
3769     Unique_Node_List visited(area);
3770     Node_List worklist(area);
3771     // We're going to walk control flow backwards starting from the Root
3772     worklist.push(_root);
3773     while (worklist.size() > 0) {
3774       Node* x = worklist.pop();
3775       if (x == NULL || x == top()) continue;
3776       if (visited.member(x)) {
3777         continue;
3778       } else {
3779         visited.push(x);
3780       }
3781 
3782       if (x->is_Region()) {
3783         for (uint i = 1; i < x->req(); i++) {
3784           worklist.push(x->in(i));
3785         }
3786       } else {
3787         worklist.push(x->in(0));
3788         // We are looking for the pattern:
3789         //                            /->ThreadLocal
3790         // If->Bool->CmpI->LoadB->AddP->ConL(marking_offset)
3791         //              \->ConI(0)
3792         // We want to verify that the If and the LoadB have the same control
3793         // See GraphKit::g1_write_barrier_pre()
3794         if (x->is_If()) {
3795           IfNode *iff = x->as_If();
3796           if (iff->in(1)->is_Bool() && iff->in(1)->in(1)->is_Cmp()) {
3797             CmpNode *cmp = iff->in(1)->in(1)->as_Cmp();
3798             if (cmp->Opcode() == Op_CmpI && cmp->in(2)->is_Con() && cmp->in(2)->bottom_type()->is_int()->get_con() == 0
3799                 && cmp->in(1)->is_Load()) {
3800               LoadNode* load = cmp->in(1)->as_Load();
3801               if (load->Opcode() == Op_LoadB && load->in(2)->is_AddP() && load->in(2)->in(2)->Opcode() == Op_ThreadLocal
3802                   && load->in(2)->in(3)->is_Con()
3803                   && load->in(2)->in(3)->bottom_type()->is_intptr_t()->get_con() == marking_offset) {
3804 
3805                 Node* if_ctrl = iff->in(0);
3806                 Node* load_ctrl = load->in(0);
3807 
3808                 if (if_ctrl != load_ctrl) {
3809                   // Skip possible CProj->NeverBranch in infinite loops
3810                   if ((if_ctrl->is_Proj() && if_ctrl->Opcode() == Op_CProj)
3811                       && (if_ctrl->in(0)->is_MultiBranch() && if_ctrl->in(0)->Opcode() == Op_NeverBranch)) {
3812                     if_ctrl = if_ctrl->in(0)->in(0);
3813                   }
3814                 }
3815                 assert(load_ctrl != NULL && if_ctrl == load_ctrl, "controls must match");
3816               }
3817             }
3818           }
3819         }
3820       }
3821     }
3822   }
3823 }
3824 
3825 #endif
3826 
3827 // The Compile object keeps track of failure reasons separately from the ciEnv.
3828 // This is required because there is not quite a 1-1 relation between the
3829 // ciEnv and its compilation task and the Compile object.  Note that one
3830 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
3831 // to backtrack and retry without subsuming loads.  Other than this backtracking
3832 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
3833 // by the logic in C2Compiler.
3834 void Compile::record_failure(const char* reason) {
3835   if (log() != NULL) {
3836     log()->elem("failure reason='%s' phase='compile'", reason);
3837   }
3838   if (_failure_reason == NULL) {
3839     // Record the first failure reason.
3840     _failure_reason = reason;
3841   }
3842 
3843   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
3844     C->print_method(PHASE_FAILURE);
3845   }
3846   _root = NULL;  // flush the graph, too
3847 }
3848 
3849 Compile::TracePhase::TracePhase(const char* name, elapsedTimer* accumulator)
3850   : TraceTime(name, accumulator, CITime, CITimeVerbose),
3851     _phase_name(name), _dolog(CITimeVerbose)
3852 {
3853   if (_dolog) {
3854     C = Compile::current();
3855     _log = C->log();
3856   } else {
3857     C = NULL;
3858     _log = NULL;
3859   }
3860   if (_log != NULL) {
3861     _log->begin_head("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
3862     _log->stamp();
3863     _log->end_head();
3864   }
3865 }
3866 
3867 Compile::TracePhase::~TracePhase() {
3868 
3869   C = Compile::current();
3870   if (_dolog) {
3871     _log = C->log();
3872   } else {
3873     _log = NULL;
3874   }
3875 
3876 #ifdef ASSERT
3877   if (PrintIdealNodeCount) {
3878     tty->print_cr("phase name='%s' nodes='%d' live='%d' live_graph_walk='%d'",
3879                   _phase_name, C->unique(), C->live_nodes(), C->count_live_nodes_by_graph_walk());
3880   }
3881 
3882   if (VerifyIdealNodeCount) {
3883     Compile::current()->print_missing_nodes();
3884   }
3885 #endif
3886 
3887   if (_log != NULL) {
3888     _log->done("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
3889   }
3890 }
3891 
3892 //=============================================================================
3893 // Two Constant's are equal when the type and the value are equal.
3894 bool Compile::Constant::operator==(const Constant& other) {
3895   if (type()          != other.type()         )  return false;
3896   if (can_be_reused() != other.can_be_reused())  return false;
3897   // For floating point values we compare the bit pattern.
3898   switch (type()) {
3899   case T_INT:
3900   case T_FLOAT:   return (_v._value.i == other._v._value.i);
3901   case T_LONG:
3902   case T_DOUBLE:  return (_v._value.j == other._v._value.j);
3903   case T_OBJECT:
3904   case T_ADDRESS: return (_v._value.l == other._v._value.l);
3905   case T_VOID:    return (_v._value.l == other._v._value.l);  // jump-table entries
3906   case T_METADATA: return (_v._metadata == other._v._metadata);
3907   default: ShouldNotReachHere();
3908   }
3909   return false;
3910 }
3911 
3912 static int type_to_size_in_bytes(BasicType t) {
3913   switch (t) {
3914   case T_INT:     return sizeof(jint   );
3915   case T_LONG:    return sizeof(jlong  );
3916   case T_FLOAT:   return sizeof(jfloat );
3917   case T_DOUBLE:  return sizeof(jdouble);
3918   case T_METADATA: return sizeof(Metadata*);
3919     // We use T_VOID as marker for jump-table entries (labels) which
3920     // need an internal word relocation.
3921   case T_VOID:
3922   case T_ADDRESS:
3923   case T_OBJECT:  return sizeof(jobject);
3924   }
3925 
3926   ShouldNotReachHere();
3927   return -1;
3928 }
3929 
3930 int Compile::ConstantTable::qsort_comparator(Constant* a, Constant* b) {
3931   // sort descending
3932   if (a->freq() > b->freq())  return -1;
3933   if (a->freq() < b->freq())  return  1;
3934   return 0;
3935 }
3936 
3937 void Compile::ConstantTable::calculate_offsets_and_size() {
3938   // First, sort the array by frequencies.
3939   _constants.sort(qsort_comparator);
3940 
3941 #ifdef ASSERT
3942   // Make sure all jump-table entries were sorted to the end of the
3943   // array (they have a negative frequency).
3944   bool found_void = false;
3945   for (int i = 0; i < _constants.length(); i++) {
3946     Constant con = _constants.at(i);
3947     if (con.type() == T_VOID)
3948       found_void = true;  // jump-tables
3949     else
3950       assert(!found_void, "wrong sorting");
3951   }
3952 #endif
3953 
3954   int offset = 0;
3955   for (int i = 0; i < _constants.length(); i++) {
3956     Constant* con = _constants.adr_at(i);
3957 
3958     // Align offset for type.
3959     int typesize = type_to_size_in_bytes(con->type());
3960     offset = align_size_up(offset, typesize);
3961     con->set_offset(offset);   // set constant's offset
3962 
3963     if (con->type() == T_VOID) {
3964       MachConstantNode* n = (MachConstantNode*) con->get_jobject();
3965       offset = offset + typesize * n->outcnt();  // expand jump-table
3966     } else {
3967       offset = offset + typesize;
3968     }
3969   }
3970 
3971   // Align size up to the next section start (which is insts; see
3972   // CodeBuffer::align_at_start).
3973   assert(_size == -1, "already set?");
3974   _size = align_size_up(offset, CodeEntryAlignment);
3975 }
3976 
3977 void Compile::ConstantTable::emit(CodeBuffer& cb) {
3978   MacroAssembler _masm(&cb);
3979   for (int i = 0; i < _constants.length(); i++) {
3980     Constant con = _constants.at(i);
3981     address constant_addr = NULL;
3982     switch (con.type()) {
3983     case T_INT:    constant_addr = _masm.int_constant(   con.get_jint()   ); break;
3984     case T_LONG:   constant_addr = _masm.long_constant(  con.get_jlong()  ); break;
3985     case T_FLOAT:  constant_addr = _masm.float_constant( con.get_jfloat() ); break;
3986     case T_DOUBLE: constant_addr = _masm.double_constant(con.get_jdouble()); break;
3987     case T_OBJECT: {
3988       jobject obj = con.get_jobject();
3989       int oop_index = _masm.oop_recorder()->find_index(obj);
3990       constant_addr = _masm.address_constant((address) obj, oop_Relocation::spec(oop_index));
3991       break;
3992     }
3993     case T_ADDRESS: {
3994       address addr = (address) con.get_jobject();
3995       constant_addr = _masm.address_constant(addr);
3996       break;
3997     }
3998     // We use T_VOID as marker for jump-table entries (labels) which
3999     // need an internal word relocation.
4000     case T_VOID: {
4001       MachConstantNode* n = (MachConstantNode*) con.get_jobject();
4002       // Fill the jump-table with a dummy word.  The real value is
4003       // filled in later in fill_jump_table.
4004       address dummy = (address) n;
4005       constant_addr = _masm.address_constant(dummy);
4006       // Expand jump-table
4007       for (uint i = 1; i < n->outcnt(); i++) {
4008         address temp_addr = _masm.address_constant(dummy + i);
4009         assert(temp_addr, "consts section too small");
4010       }
4011       break;
4012     }
4013     case T_METADATA: {
4014       Metadata* obj = con.get_metadata();
4015       int metadata_index = _masm.oop_recorder()->find_index(obj);
4016       constant_addr = _masm.address_constant((address) obj, metadata_Relocation::spec(metadata_index));
4017       break;
4018     }
4019     default: ShouldNotReachHere();
4020     }
4021     assert(constant_addr, "consts section too small");
4022     assert((constant_addr - _masm.code()->consts()->start()) == con.offset(),
4023             "must be: %d == %d", (int) (constant_addr - _masm.code()->consts()->start()), (int)(con.offset()));
4024   }
4025 }
4026 
4027 int Compile::ConstantTable::find_offset(Constant& con) const {
4028   int idx = _constants.find(con);
4029   assert(idx != -1, "constant must be in constant table");
4030   int offset = _constants.at(idx).offset();
4031   assert(offset != -1, "constant table not emitted yet?");
4032   return offset;
4033 }
4034 
4035 void Compile::ConstantTable::add(Constant& con) {
4036   if (con.can_be_reused()) {
4037     int idx = _constants.find(con);
4038     if (idx != -1 && _constants.at(idx).can_be_reused()) {
4039       _constants.adr_at(idx)->inc_freq(con.freq());  // increase the frequency by the current value
4040       return;
4041     }
4042   }
4043   (void) _constants.append(con);
4044 }
4045 
4046 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, BasicType type, jvalue value) {
4047   Block* b = Compile::current()->cfg()->get_block_for_node(n);
4048   Constant con(type, value, b->_freq);
4049   add(con);
4050   return con;
4051 }
4052 
4053 Compile::Constant Compile::ConstantTable::add(Metadata* metadata) {
4054   Constant con(metadata);
4055   add(con);
4056   return con;
4057 }
4058 
4059 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, MachOper* oper) {
4060   jvalue value;
4061   BasicType type = oper->type()->basic_type();
4062   switch (type) {
4063   case T_LONG:    value.j = oper->constantL(); break;
4064   case T_FLOAT:   value.f = oper->constantF(); break;
4065   case T_DOUBLE:  value.d = oper->constantD(); break;
4066   case T_OBJECT:
4067   case T_ADDRESS: value.l = (jobject) oper->constant(); break;
4068   case T_METADATA: return add((Metadata*)oper->constant()); break;
4069   default: guarantee(false, "unhandled type: %s", type2name(type));
4070   }
4071   return add(n, type, value);
4072 }
4073 
4074 Compile::Constant Compile::ConstantTable::add_jump_table(MachConstantNode* n) {
4075   jvalue value;
4076   // We can use the node pointer here to identify the right jump-table
4077   // as this method is called from Compile::Fill_buffer right before
4078   // the MachNodes are emitted and the jump-table is filled (means the
4079   // MachNode pointers do not change anymore).
4080   value.l = (jobject) n;
4081   Constant con(T_VOID, value, next_jump_table_freq(), false);  // Labels of a jump-table cannot be reused.
4082   add(con);
4083   return con;
4084 }
4085 
4086 void Compile::ConstantTable::fill_jump_table(CodeBuffer& cb, MachConstantNode* n, GrowableArray<Label*> labels) const {
4087   // If called from Compile::scratch_emit_size do nothing.
4088   if (Compile::current()->in_scratch_emit_size())  return;
4089 
4090   assert(labels.is_nonempty(), "must be");
4091   assert((uint) labels.length() == n->outcnt(), "must be equal: %d == %d", labels.length(), n->outcnt());
4092 
4093   // Since MachConstantNode::constant_offset() also contains
4094   // table_base_offset() we need to subtract the table_base_offset()
4095   // to get the plain offset into the constant table.
4096   int offset = n->constant_offset() - table_base_offset();
4097 
4098   MacroAssembler _masm(&cb);
4099   address* jump_table_base = (address*) (_masm.code()->consts()->start() + offset);
4100 
4101   for (uint i = 0; i < n->outcnt(); i++) {
4102     address* constant_addr = &jump_table_base[i];
4103     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));
4104     *constant_addr = cb.consts()->target(*labels.at(i), (address) constant_addr);
4105     cb.consts()->relocate((address) constant_addr, relocInfo::internal_word_type);
4106   }
4107 }
4108 
4109 //----------------------------static_subtype_check-----------------------------
4110 // Shortcut important common cases when superklass is exact:
4111 // (0) superklass is java.lang.Object (can occur in reflective code)
4112 // (1) subklass is already limited to a subtype of superklass => always ok
4113 // (2) subklass does not overlap with superklass => always fail
4114 // (3) superklass has NO subtypes and we can check with a simple compare.
4115 int Compile::static_subtype_check(ciKlass* superk, ciKlass* subk) {
4116   if (StressReflectiveCode || superk == NULL || subk == NULL) {
4117     return SSC_full_test;       // Let caller generate the general case.
4118   }
4119 
4120   if (!EnableMVT && !EnableValhalla && superk == env()->Object_klass()) {
4121     return SSC_always_true;     // (0) this test cannot fail
4122   }
4123 
4124   ciType* superelem = superk;
4125   if (superelem->is_array_klass())
4126     superelem = superelem->as_array_klass()->base_element_type();
4127 
4128   if (!subk->is_interface()) {  // cannot trust static interface types yet
4129     if (subk->is_subtype_of(superk)) {
4130       return SSC_always_true;   // (1) false path dead; no dynamic test needed
4131     }
4132     if (!(superelem->is_klass() && superelem->as_klass()->is_interface()) &&
4133         !superk->is_subtype_of(subk)) {
4134       return SSC_always_false;
4135     }
4136   }
4137 
4138   // If casting to an instance klass, it must have no subtypes
4139   if (superk->is_interface()) {
4140     // Cannot trust interfaces yet.
4141     // %%% S.B. superk->nof_implementors() == 1
4142   } else if (superelem->is_instance_klass()) {
4143     ciInstanceKlass* ik = superelem->as_instance_klass();
4144     if (!ik->has_subklass() && !ik->is_interface()) {
4145       if (!ik->is_final()) {
4146         // Add a dependency if there is a chance of a later subclass.
4147         dependencies()->assert_leaf_type(ik);
4148       }
4149       return SSC_easy_test;     // (3) caller can do a simple ptr comparison
4150     }
4151   } else {
4152     // A primitive array type has no subtypes.
4153     return SSC_easy_test;       // (3) caller can do a simple ptr comparison
4154   }
4155 
4156   return SSC_full_test;
4157 }
4158 
4159 Node* Compile::conv_I2X_index(PhaseGVN* phase, Node* idx, const TypeInt* sizetype, Node* ctrl) {
4160 #ifdef _LP64
4161   // The scaled index operand to AddP must be a clean 64-bit value.
4162   // Java allows a 32-bit int to be incremented to a negative
4163   // value, which appears in a 64-bit register as a large
4164   // positive number.  Using that large positive number as an
4165   // operand in pointer arithmetic has bad consequences.
4166   // On the other hand, 32-bit overflow is rare, and the possibility
4167   // can often be excluded, if we annotate the ConvI2L node with
4168   // a type assertion that its value is known to be a small positive
4169   // number.  (The prior range check has ensured this.)
4170   // This assertion is used by ConvI2LNode::Ideal.
4171   int index_max = max_jint - 1;  // array size is max_jint, index is one less
4172   if (sizetype != NULL) index_max = sizetype->_hi - 1;
4173   const TypeInt* iidxtype = TypeInt::make(0, index_max, Type::WidenMax);
4174   idx = constrained_convI2L(phase, idx, iidxtype, ctrl);
4175 #endif
4176   return idx;
4177 }
4178 
4179 // Convert integer value to a narrowed long type dependent on ctrl (for example, a range check)
4180 Node* Compile::constrained_convI2L(PhaseGVN* phase, Node* value, const TypeInt* itype, Node* ctrl) {
4181   if (ctrl != NULL) {
4182     // Express control dependency by a CastII node with a narrow type.
4183     value = new CastIINode(value, itype, false, true /* range check dependency */);
4184     // Make the CastII node dependent on the control input to prevent the narrowed ConvI2L
4185     // node from floating above the range check during loop optimizations. Otherwise, the
4186     // ConvI2L node may be eliminated independently of the range check, causing the data path
4187     // to become TOP while the control path is still there (although it's unreachable).
4188     value->set_req(0, ctrl);
4189     // Save CastII node to remove it after loop optimizations.
4190     phase->C->add_range_check_cast(value);
4191     value = phase->transform(value);
4192   }
4193   const TypeLong* ltype = TypeLong::make(itype->_lo, itype->_hi, itype->_widen);
4194   return phase->transform(new ConvI2LNode(value, ltype));
4195 }
4196 
4197 // The message about the current inlining is accumulated in
4198 // _print_inlining_stream and transfered into the _print_inlining_list
4199 // once we know whether inlining succeeds or not. For regular
4200 // inlining, messages are appended to the buffer pointed by
4201 // _print_inlining_idx in the _print_inlining_list. For late inlining,
4202 // a new buffer is added after _print_inlining_idx in the list. This
4203 // way we can update the inlining message for late inlining call site
4204 // when the inlining is attempted again.
4205 void Compile::print_inlining_init() {
4206   if (print_inlining() || print_intrinsics()) {
4207     _print_inlining_stream = new stringStream();
4208     _print_inlining_list = new (comp_arena())GrowableArray<PrintInliningBuffer>(comp_arena(), 1, 1, PrintInliningBuffer());
4209   }
4210 }
4211 
4212 void Compile::print_inlining_reinit() {
4213   if (print_inlining() || print_intrinsics()) {
4214     // Re allocate buffer when we change ResourceMark
4215     _print_inlining_stream = new stringStream();
4216   }
4217 }
4218 
4219 void Compile::print_inlining_reset() {
4220   _print_inlining_stream->reset();
4221 }
4222 
4223 void Compile::print_inlining_commit() {
4224   assert(print_inlining() || print_intrinsics(), "PrintInlining off?");
4225   // Transfer the message from _print_inlining_stream to the current
4226   // _print_inlining_list buffer and clear _print_inlining_stream.
4227   _print_inlining_list->at(_print_inlining_idx).ss()->write(_print_inlining_stream->as_string(), _print_inlining_stream->size());
4228   print_inlining_reset();
4229 }
4230 
4231 void Compile::print_inlining_push() {
4232   // Add new buffer to the _print_inlining_list at current position
4233   _print_inlining_idx++;
4234   _print_inlining_list->insert_before(_print_inlining_idx, PrintInliningBuffer());
4235 }
4236 
4237 Compile::PrintInliningBuffer& Compile::print_inlining_current() {
4238   return _print_inlining_list->at(_print_inlining_idx);
4239 }
4240 
4241 void Compile::print_inlining_update(CallGenerator* cg) {
4242   if (print_inlining() || print_intrinsics()) {
4243     if (!cg->is_late_inline()) {
4244       if (print_inlining_current().cg() != NULL) {
4245         print_inlining_push();
4246       }
4247       print_inlining_commit();
4248     } else {
4249       if (print_inlining_current().cg() != cg &&
4250           (print_inlining_current().cg() != NULL ||
4251            print_inlining_current().ss()->size() != 0)) {
4252         print_inlining_push();
4253       }
4254       print_inlining_commit();
4255       print_inlining_current().set_cg(cg);
4256     }
4257   }
4258 }
4259 
4260 void Compile::print_inlining_move_to(CallGenerator* cg) {
4261   // We resume inlining at a late inlining call site. Locate the
4262   // corresponding inlining buffer so that we can update it.
4263   if (print_inlining()) {
4264     for (int i = 0; i < _print_inlining_list->length(); i++) {
4265       if (_print_inlining_list->adr_at(i)->cg() == cg) {
4266         _print_inlining_idx = i;
4267         return;
4268       }
4269     }
4270     ShouldNotReachHere();
4271   }
4272 }
4273 
4274 void Compile::print_inlining_update_delayed(CallGenerator* cg) {
4275   if (print_inlining()) {
4276     assert(_print_inlining_stream->size() > 0, "missing inlining msg");
4277     assert(print_inlining_current().cg() == cg, "wrong entry");
4278     // replace message with new message
4279     _print_inlining_list->at_put(_print_inlining_idx, PrintInliningBuffer());
4280     print_inlining_commit();
4281     print_inlining_current().set_cg(cg);
4282   }
4283 }
4284 
4285 void Compile::print_inlining_assert_ready() {
4286   assert(!_print_inlining || _print_inlining_stream->size() == 0, "loosing data");
4287 }
4288 
4289 void Compile::process_print_inlining() {
4290   bool do_print_inlining = print_inlining() || print_intrinsics();
4291   if (do_print_inlining || log() != NULL) {
4292     // Print inlining message for candidates that we couldn't inline
4293     // for lack of space
4294     for (int i = 0; i < _late_inlines.length(); i++) {
4295       CallGenerator* cg = _late_inlines.at(i);
4296       if (!cg->is_mh_late_inline()) {
4297         const char* msg = "live nodes > LiveNodeCountInliningCutoff";
4298         if (do_print_inlining) {
4299           cg->print_inlining_late(msg);
4300         }
4301         log_late_inline_failure(cg, msg);
4302       }
4303     }
4304   }
4305   if (do_print_inlining) {
4306     ResourceMark rm;
4307     stringStream ss;
4308     for (int i = 0; i < _print_inlining_list->length(); i++) {
4309       ss.print("%s", _print_inlining_list->adr_at(i)->ss()->as_string());
4310     }
4311     size_t end = ss.size();
4312     _print_inlining_output = NEW_ARENA_ARRAY(comp_arena(), char, end+1);
4313     strncpy(_print_inlining_output, ss.base(), end+1);
4314     _print_inlining_output[end] = 0;
4315   }
4316 }
4317 
4318 void Compile::dump_print_inlining() {
4319   if (_print_inlining_output != NULL) {
4320     tty->print_raw(_print_inlining_output);
4321   }
4322 }
4323 
4324 void Compile::log_late_inline(CallGenerator* cg) {
4325   if (log() != NULL) {
4326     log()->head("late_inline method='%d'  inline_id='" JLONG_FORMAT "'", log()->identify(cg->method()),
4327                 cg->unique_id());
4328     JVMState* p = cg->call_node()->jvms();
4329     while (p != NULL) {
4330       log()->elem("jvms bci='%d' method='%d'", p->bci(), log()->identify(p->method()));
4331       p = p->caller();
4332     }
4333     log()->tail("late_inline");
4334   }
4335 }
4336 
4337 void Compile::log_late_inline_failure(CallGenerator* cg, const char* msg) {
4338   log_late_inline(cg);
4339   if (log() != NULL) {
4340     log()->inline_fail(msg);
4341   }
4342 }
4343 
4344 void Compile::log_inline_id(CallGenerator* cg) {
4345   if (log() != NULL) {
4346     // The LogCompilation tool needs a unique way to identify late
4347     // inline call sites. This id must be unique for this call site in
4348     // this compilation. Try to have it unique across compilations as
4349     // well because it can be convenient when grepping through the log
4350     // file.
4351     // Distinguish OSR compilations from others in case CICountOSR is
4352     // on.
4353     jlong id = ((jlong)unique()) + (((jlong)compile_id()) << 33) + (CICountOSR && is_osr_compilation() ? ((jlong)1) << 32 : 0);
4354     cg->set_unique_id(id);
4355     log()->elem("inline_id id='" JLONG_FORMAT "'", id);
4356   }
4357 }
4358 
4359 void Compile::log_inline_failure(const char* msg) {
4360   if (C->log() != NULL) {
4361     C->log()->inline_fail(msg);
4362   }
4363 }
4364 
4365 
4366 // Dump inlining replay data to the stream.
4367 // Don't change thread state and acquire any locks.
4368 void Compile::dump_inline_data(outputStream* out) {
4369   InlineTree* inl_tree = ilt();
4370   if (inl_tree != NULL) {
4371     out->print(" inline %d", inl_tree->count());
4372     inl_tree->dump_replay_data(out);
4373   }
4374 }
4375 
4376 int Compile::cmp_expensive_nodes(Node* n1, Node* n2) {
4377   if (n1->Opcode() < n2->Opcode())      return -1;
4378   else if (n1->Opcode() > n2->Opcode()) return 1;
4379 
4380   assert(n1->req() == n2->req(), "can't compare %s nodes: n1->req() = %d, n2->req() = %d", NodeClassNames[n1->Opcode()], n1->req(), n2->req());
4381   for (uint i = 1; i < n1->req(); i++) {
4382     if (n1->in(i) < n2->in(i))      return -1;
4383     else if (n1->in(i) > n2->in(i)) return 1;
4384   }
4385 
4386   return 0;
4387 }
4388 
4389 int Compile::cmp_expensive_nodes(Node** n1p, Node** n2p) {
4390   Node* n1 = *n1p;
4391   Node* n2 = *n2p;
4392 
4393   return cmp_expensive_nodes(n1, n2);
4394 }
4395 
4396 void Compile::sort_expensive_nodes() {
4397   if (!expensive_nodes_sorted()) {
4398     _expensive_nodes->sort(cmp_expensive_nodes);
4399   }
4400 }
4401 
4402 bool Compile::expensive_nodes_sorted() const {
4403   for (int i = 1; i < _expensive_nodes->length(); i++) {
4404     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i-1)) < 0) {
4405       return false;
4406     }
4407   }
4408   return true;
4409 }
4410 
4411 bool Compile::should_optimize_expensive_nodes(PhaseIterGVN &igvn) {
4412   if (_expensive_nodes->length() == 0) {
4413     return false;
4414   }
4415 
4416   assert(OptimizeExpensiveOps, "optimization off?");
4417 
4418   // Take this opportunity to remove dead nodes from the list
4419   int j = 0;
4420   for (int i = 0; i < _expensive_nodes->length(); i++) {
4421     Node* n = _expensive_nodes->at(i);
4422     if (!n->is_unreachable(igvn)) {
4423       assert(n->is_expensive(), "should be expensive");
4424       _expensive_nodes->at_put(j, n);
4425       j++;
4426     }
4427   }
4428   _expensive_nodes->trunc_to(j);
4429 
4430   // Then sort the list so that similar nodes are next to each other
4431   // and check for at least two nodes of identical kind with same data
4432   // inputs.
4433   sort_expensive_nodes();
4434 
4435   for (int i = 0; i < _expensive_nodes->length()-1; i++) {
4436     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i+1)) == 0) {
4437       return true;
4438     }
4439   }
4440 
4441   return false;
4442 }
4443 
4444 void Compile::cleanup_expensive_nodes(PhaseIterGVN &igvn) {
4445   if (_expensive_nodes->length() == 0) {
4446     return;
4447   }
4448 
4449   assert(OptimizeExpensiveOps, "optimization off?");
4450 
4451   // Sort to bring similar nodes next to each other and clear the
4452   // control input of nodes for which there's only a single copy.
4453   sort_expensive_nodes();
4454 
4455   int j = 0;
4456   int identical = 0;
4457   int i = 0;
4458   bool modified = false;
4459   for (; i < _expensive_nodes->length()-1; i++) {
4460     assert(j <= i, "can't write beyond current index");
4461     if (_expensive_nodes->at(i)->Opcode() == _expensive_nodes->at(i+1)->Opcode()) {
4462       identical++;
4463       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4464       continue;
4465     }
4466     if (identical > 0) {
4467       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4468       identical = 0;
4469     } else {
4470       Node* n = _expensive_nodes->at(i);
4471       igvn.replace_input_of(n, 0, NULL);
4472       igvn.hash_insert(n);
4473       modified = true;
4474     }
4475   }
4476   if (identical > 0) {
4477     _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4478   } else if (_expensive_nodes->length() >= 1) {
4479     Node* n = _expensive_nodes->at(i);
4480     igvn.replace_input_of(n, 0, NULL);
4481     igvn.hash_insert(n);
4482     modified = true;
4483   }
4484   _expensive_nodes->trunc_to(j);
4485   if (modified) {
4486     igvn.optimize();
4487   }
4488 }
4489 
4490 void Compile::add_expensive_node(Node * n) {
4491   assert(!_expensive_nodes->contains(n), "duplicate entry in expensive list");
4492   assert(n->is_expensive(), "expensive nodes with non-null control here only");
4493   assert(!n->is_CFG() && !n->is_Mem(), "no cfg or memory nodes here");
4494   if (OptimizeExpensiveOps) {
4495     _expensive_nodes->append(n);
4496   } else {
4497     // Clear control input and let IGVN optimize expensive nodes if
4498     // OptimizeExpensiveOps is off.
4499     n->set_req(0, NULL);
4500   }
4501 }
4502 
4503 /**
4504  * Remove the speculative part of types and clean up the graph
4505  */
4506 void Compile::remove_speculative_types(PhaseIterGVN &igvn) {
4507   if (UseTypeSpeculation) {
4508     Unique_Node_List worklist;
4509     worklist.push(root());
4510     int modified = 0;
4511     // Go over all type nodes that carry a speculative type, drop the
4512     // speculative part of the type and enqueue the node for an igvn
4513     // which may optimize it out.
4514     for (uint next = 0; next < worklist.size(); ++next) {
4515       Node *n  = worklist.at(next);
4516       if (n->is_Type()) {
4517         TypeNode* tn = n->as_Type();
4518         const Type* t = tn->type();
4519         const Type* t_no_spec = t->remove_speculative();
4520         if (t_no_spec != t) {
4521           bool in_hash = igvn.hash_delete(n);
4522           assert(in_hash, "node should be in igvn hash table");
4523           tn->set_type(t_no_spec);
4524           igvn.hash_insert(n);
4525           igvn._worklist.push(n); // give it a chance to go away
4526           modified++;
4527         }
4528       }
4529       uint max = n->len();
4530       for( uint i = 0; i < max; ++i ) {
4531         Node *m = n->in(i);
4532         if (not_a_node(m))  continue;
4533         worklist.push(m);
4534       }
4535     }
4536     // Drop the speculative part of all types in the igvn's type table
4537     igvn.remove_speculative_types();
4538     if (modified > 0) {
4539       igvn.optimize();
4540     }
4541 #ifdef ASSERT
4542     // Verify that after the IGVN is over no speculative type has resurfaced
4543     worklist.clear();
4544     worklist.push(root());
4545     for (uint next = 0; next < worklist.size(); ++next) {
4546       Node *n  = worklist.at(next);
4547       const Type* t = igvn.type_or_null(n);
4548       assert((t == NULL) || (t == t->remove_speculative()), "no more speculative types");
4549       if (n->is_Type()) {
4550         t = n->as_Type()->type();
4551         assert(t == t->remove_speculative(), "no more speculative types");
4552       }
4553       uint max = n->len();
4554       for( uint i = 0; i < max; ++i ) {
4555         Node *m = n->in(i);
4556         if (not_a_node(m))  continue;
4557         worklist.push(m);
4558       }
4559     }
4560     igvn.check_no_speculative_types();
4561 #endif
4562   }
4563 }
4564 
4565 // Auxiliary method to support randomized stressing/fuzzing.
4566 //
4567 // This method can be called the arbitrary number of times, with current count
4568 // as the argument. The logic allows selecting a single candidate from the
4569 // running list of candidates as follows:
4570 //    int count = 0;
4571 //    Cand* selected = null;
4572 //    while(cand = cand->next()) {
4573 //      if (randomized_select(++count)) {
4574 //        selected = cand;
4575 //      }
4576 //    }
4577 //
4578 // Including count equalizes the chances any candidate is "selected".
4579 // This is useful when we don't have the complete list of candidates to choose
4580 // from uniformly. In this case, we need to adjust the randomicity of the
4581 // selection, or else we will end up biasing the selection towards the latter
4582 // candidates.
4583 //
4584 // Quick back-envelope calculation shows that for the list of n candidates
4585 // the equal probability for the candidate to persist as "best" can be
4586 // achieved by replacing it with "next" k-th candidate with the probability
4587 // of 1/k. It can be easily shown that by the end of the run, the
4588 // probability for any candidate is converged to 1/n, thus giving the
4589 // uniform distribution among all the candidates.
4590 //
4591 // We don't care about the domain size as long as (RANDOMIZED_DOMAIN / count) is large.
4592 #define RANDOMIZED_DOMAIN_POW 29
4593 #define RANDOMIZED_DOMAIN (1 << RANDOMIZED_DOMAIN_POW)
4594 #define RANDOMIZED_DOMAIN_MASK ((1 << (RANDOMIZED_DOMAIN_POW + 1)) - 1)
4595 bool Compile::randomized_select(int count) {
4596   assert(count > 0, "only positive");
4597   return (os::random() & RANDOMIZED_DOMAIN_MASK) < (RANDOMIZED_DOMAIN / count);
4598 }
4599 
4600 CloneMap&     Compile::clone_map()                 { return _clone_map; }
4601 void          Compile::set_clone_map(Dict* d)      { _clone_map._dict = d; }
4602 
4603 void NodeCloneInfo::dump() const {
4604   tty->print(" {%d:%d} ", idx(), gen());
4605 }
4606 
4607 void CloneMap::clone(Node* old, Node* nnn, int gen) {
4608   uint64_t val = value(old->_idx);
4609   NodeCloneInfo cio(val);
4610   assert(val != 0, "old node should be in the map");
4611   NodeCloneInfo cin(cio.idx(), gen + cio.gen());
4612   insert(nnn->_idx, cin.get());
4613 #ifndef PRODUCT
4614   if (is_debug()) {
4615     tty->print_cr("CloneMap::clone inserted node %d info {%d:%d} into CloneMap", nnn->_idx, cin.idx(), cin.gen());
4616   }
4617 #endif
4618 }
4619 
4620 void CloneMap::verify_insert_and_clone(Node* old, Node* nnn, int gen) {
4621   NodeCloneInfo cio(value(old->_idx));
4622   if (cio.get() == 0) {
4623     cio.set(old->_idx, 0);
4624     insert(old->_idx, cio.get());
4625 #ifndef PRODUCT
4626     if (is_debug()) {
4627       tty->print_cr("CloneMap::verify_insert_and_clone inserted node %d info {%d:%d} into CloneMap", old->_idx, cio.idx(), cio.gen());
4628     }
4629 #endif
4630   }
4631   clone(old, nnn, gen);
4632 }
4633 
4634 int CloneMap::max_gen() const {
4635   int g = 0;
4636   DictI di(_dict);
4637   for(; di.test(); ++di) {
4638     int t = gen(di._key);
4639     if (g < t) {
4640       g = t;
4641 #ifndef PRODUCT
4642       if (is_debug()) {
4643         tty->print_cr("CloneMap::max_gen() update max=%d from %d", g, _2_node_idx_t(di._key));
4644       }
4645 #endif
4646     }
4647   }
4648   return g;
4649 }
4650 
4651 void CloneMap::dump(node_idx_t key) const {
4652   uint64_t val = value(key);
4653   if (val != 0) {
4654     NodeCloneInfo ni(val);
4655     ni.dump();
4656   }
4657 }
4658 
4659 // Helper function for enforcing certain bytecodes to reexecute if
4660 // deoptimization happens
4661 static bool should_reexecute_implied_by_bytecode(JVMState *jvms, bool is_anewarray) {
4662   ciMethod* cur_method = jvms->method();
4663   int       cur_bci   = jvms->bci();
4664   if (cur_method != NULL && cur_bci != InvocationEntryBci) {
4665     Bytecodes::Code code = cur_method->java_code_at_bci(cur_bci);
4666     return Interpreter::bytecode_should_reexecute(code) ||
4667            is_anewarray && code == Bytecodes::_multianewarray;
4668     // Reexecute _multianewarray bytecode which was replaced with
4669     // sequence of [a]newarray. See Parse::do_multianewarray().
4670     //
4671     // Note: interpreter should not have it set since this optimization
4672     // is limited by dimensions and guarded by flag so in some cases
4673     // multianewarray() runtime calls will be generated and
4674     // the bytecode should not be reexecutes (stack will not be reset).
4675   } else
4676     return false;
4677 }
4678 
4679 void Compile::add_safepoint_edges(SafePointNode* call, JVMState* youngest_jvms, bool can_prune_locals, uint stack_slots_not_pruned) {
4680   // do not scribble on the input jvms
4681   JVMState* out_jvms = youngest_jvms->clone_deep(C);
4682   call->set_jvms(out_jvms); // Start jvms list for call node
4683 
4684   // For a known set of bytecodes, the interpreter should reexecute them if
4685   // deoptimization happens. We set the reexecute state for them here
4686   if (out_jvms->is_reexecute_undefined() && //don't change if already specified
4687       should_reexecute_implied_by_bytecode(out_jvms, call->is_AllocateArray())) {
4688     out_jvms->set_should_reexecute(true); //NOTE: youngest_jvms not changed
4689   }
4690 
4691   // Presize the call:
4692   DEBUG_ONLY(uint non_debug_edges = call->req());
4693   call->add_req_batch(top(), youngest_jvms->debug_depth());
4694   assert(call->req() == non_debug_edges + youngest_jvms->debug_depth(), "");
4695 
4696   // Set up edges so that the call looks like this:
4697   //  Call [state:] ctl io mem fptr retadr
4698   //       [parms:] parm0 ... parmN
4699   //       [root:]  loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN
4700   //    [...mid:]   loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN [...]
4701   //       [young:] loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN
4702   // Note that caller debug info precedes callee debug info.
4703 
4704   // Fill pointer walks backwards from "young:" to "root:" in the diagram above:
4705   uint debug_ptr = call->req();
4706 
4707   // Loop over the map input edges associated with jvms, add them
4708   // to the call node, & reset all offsets to match call node array.
4709   for (JVMState* in_jvms = youngest_jvms; in_jvms != NULL; ) {
4710     uint debug_end   = debug_ptr;
4711     uint debug_start = debug_ptr - in_jvms->debug_size();
4712     debug_ptr = debug_start;  // back up the ptr
4713 
4714     uint p = debug_start;  // walks forward in [debug_start, debug_end)
4715     uint j, k, l;
4716     SafePointNode* in_map = in_jvms->map();
4717     out_jvms->set_map(call);
4718 
4719     if (can_prune_locals) {
4720       assert(in_jvms->method() == out_jvms->method(), "sanity");
4721       // If the current throw can reach an exception handler in this JVMS,
4722       // then we must keep everything live that can reach that handler.
4723       // As a quick and dirty approximation, we look for any handlers at all.
4724       if (in_jvms->method()->has_exception_handlers()) {
4725         can_prune_locals = false;
4726       }
4727     }
4728 
4729     // Add the Locals
4730     k = in_jvms->locoff();
4731     l = in_jvms->loc_size();
4732     out_jvms->set_locoff(p);
4733     if (!can_prune_locals) {
4734       for (j = 0; j < l; j++)
4735         call->set_req(p++, in_map->in(k+j));
4736     } else {
4737       p += l;  // already set to top above by add_req_batch
4738     }
4739 
4740     // Add the Expression Stack
4741     k = in_jvms->stkoff();
4742     l = in_jvms->sp();
4743     out_jvms->set_stkoff(p);
4744     if (!can_prune_locals) {
4745       for (j = 0; j < l; j++)
4746         call->set_req(p++, in_map->in(k+j));
4747     } else if (can_prune_locals && stack_slots_not_pruned != 0) {
4748       // Divide stack into {S0,...,S1}, where S0 is set to top.
4749       uint s1 = stack_slots_not_pruned;
4750       stack_slots_not_pruned = 0;  // for next iteration
4751       if (s1 > l)  s1 = l;
4752       uint s0 = l - s1;
4753       p += s0;  // skip the tops preinstalled by add_req_batch
4754       for (j = s0; j < l; j++)
4755         call->set_req(p++, in_map->in(k+j));
4756     } else {
4757       p += l;  // already set to top above by add_req_batch
4758     }
4759 
4760     // Add the Monitors
4761     k = in_jvms->monoff();
4762     l = in_jvms->mon_size();
4763     out_jvms->set_monoff(p);
4764     for (j = 0; j < l; j++)
4765       call->set_req(p++, in_map->in(k+j));
4766 
4767     // Copy any scalar object fields.
4768     k = in_jvms->scloff();
4769     l = in_jvms->scl_size();
4770     out_jvms->set_scloff(p);
4771     for (j = 0; j < l; j++)
4772       call->set_req(p++, in_map->in(k+j));
4773 
4774     // Finish the new jvms.
4775     out_jvms->set_endoff(p);
4776 
4777     assert(out_jvms->endoff()     == debug_end,             "fill ptr must match");
4778     assert(out_jvms->depth()      == in_jvms->depth(),      "depth must match");
4779     assert(out_jvms->loc_size()   == in_jvms->loc_size(),   "size must match");
4780     assert(out_jvms->mon_size()   == in_jvms->mon_size(),   "size must match");
4781     assert(out_jvms->scl_size()   == in_jvms->scl_size(),   "size must match");
4782     assert(out_jvms->debug_size() == in_jvms->debug_size(), "size must match");
4783 
4784     // Update the two tail pointers in parallel.
4785     out_jvms = out_jvms->caller();
4786     in_jvms  = in_jvms->caller();
4787   }
4788 
4789   assert(debug_ptr == non_debug_edges, "debug info must fit exactly");
4790 
4791   // Test the correctness of JVMState::debug_xxx accessors:
4792   assert(call->jvms()->debug_start() == non_debug_edges, "");
4793   assert(call->jvms()->debug_end()   == call->req(), "");
4794   assert(call->jvms()->debug_depth() == call->req() - non_debug_edges, "");
4795 }