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