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