1 /*
   2  * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "asm/macroAssembler.hpp"
  27 #include "asm/macroAssembler.inline.hpp"
  28 #include "ci/ciReplay.hpp"
  29 #include "classfile/systemDictionary.hpp"
  30 #include "code/exceptionHandlerTable.hpp"
  31 #include "code/nmethod.hpp"
  32 #include "compiler/compileBroker.hpp"
  33 #include "compiler/compileLog.hpp"
  34 #include "compiler/disassembler.hpp"
  35 #include "compiler/oopMap.hpp"
  36 #include "gc/shared/barrierSet.hpp"
  37 #include "gc/shared/c2/barrierSetC2.hpp"
  38 #include "memory/resourceArea.hpp"
  39 #include "opto/addnode.hpp"
  40 #include "opto/block.hpp"
  41 #include "opto/c2compiler.hpp"
  42 #include "opto/callGenerator.hpp"
  43 #include "opto/callnode.hpp"
  44 #include "opto/castnode.hpp"
  45 #include "opto/cfgnode.hpp"
  46 #include "opto/chaitin.hpp"
  47 #include "opto/compile.hpp"
  48 #include "opto/connode.hpp"
  49 #include "opto/convertnode.hpp"
  50 #include "opto/divnode.hpp"
  51 #include "opto/escape.hpp"
  52 #include "opto/idealGraphPrinter.hpp"
  53 #include "opto/loopnode.hpp"
  54 #include "opto/machnode.hpp"
  55 #include "opto/macro.hpp"
  56 #include "opto/matcher.hpp"
  57 #include "opto/mathexactnode.hpp"
  58 #include "opto/memnode.hpp"
  59 #include "opto/mulnode.hpp"
  60 #include "opto/narrowptrnode.hpp"
  61 #include "opto/node.hpp"
  62 #include "opto/opcodes.hpp"
  63 #include "opto/output.hpp"
  64 #include "opto/parse.hpp"
  65 #include "opto/phaseX.hpp"
  66 #include "opto/rootnode.hpp"
  67 #include "opto/runtime.hpp"
  68 #include "opto/stringopts.hpp"
  69 #include "opto/type.hpp"
  70 #include "opto/valuetypenode.hpp"
  71 #include "opto/vectornode.hpp"
  72 #include "runtime/arguments.hpp"
  73 #include "runtime/sharedRuntime.hpp"
  74 #include "runtime/signature.hpp"
  75 #include "runtime/stubRoutines.hpp"
  76 #include "runtime/timer.hpp"
  77 #include "utilities/align.hpp"
  78 #include "utilities/copy.hpp"
  79 #include "utilities/macros.hpp"
  80 #if INCLUDE_ZGC
  81 #include "gc/z/c2/zBarrierSetC2.hpp"
  82 #endif
  83 
  84 
  85 // -------------------- Compile::mach_constant_base_node -----------------------
  86 // Constant table base node singleton.
  87 MachConstantBaseNode* Compile::mach_constant_base_node() {
  88   if (_mach_constant_base_node == NULL) {
  89     _mach_constant_base_node = new MachConstantBaseNode();
  90     _mach_constant_base_node->add_req(C->root());
  91   }
  92   return _mach_constant_base_node;
  93 }
  94 
  95 
  96 /// Support for intrinsics.
  97 
  98 // Return the index at which m must be inserted (or already exists).
  99 // The sort order is by the address of the ciMethod, with is_virtual as minor key.
 100 class IntrinsicDescPair {
 101  private:
 102   ciMethod* _m;
 103   bool _is_virtual;
 104  public:
 105   IntrinsicDescPair(ciMethod* m, bool is_virtual) : _m(m), _is_virtual(is_virtual) {}
 106   static int compare(IntrinsicDescPair* const& key, CallGenerator* const& elt) {
 107     ciMethod* m= elt->method();
 108     ciMethod* key_m = key->_m;
 109     if (key_m < m)      return -1;
 110     else if (key_m > m) return 1;
 111     else {
 112       bool is_virtual = elt->is_virtual();
 113       bool key_virtual = key->_is_virtual;
 114       if (key_virtual < is_virtual)      return -1;
 115       else if (key_virtual > is_virtual) return 1;
 116       else                               return 0;
 117     }
 118   }
 119 };
 120 int Compile::intrinsic_insertion_index(ciMethod* m, bool is_virtual, bool& found) {
 121 #ifdef ASSERT
 122   for (int i = 1; i < _intrinsics->length(); i++) {
 123     CallGenerator* cg1 = _intrinsics->at(i-1);
 124     CallGenerator* cg2 = _intrinsics->at(i);
 125     assert(cg1->method() != cg2->method()
 126            ? cg1->method()     < cg2->method()
 127            : cg1->is_virtual() < cg2->is_virtual(),
 128            "compiler intrinsics list must stay sorted");
 129   }
 130 #endif
 131   IntrinsicDescPair pair(m, is_virtual);
 132   return _intrinsics->find_sorted<IntrinsicDescPair*, IntrinsicDescPair::compare>(&pair, found);
 133 }
 134 
 135 void Compile::register_intrinsic(CallGenerator* cg) {
 136   if (_intrinsics == NULL) {
 137     _intrinsics = new (comp_arena())GrowableArray<CallGenerator*>(comp_arena(), 60, 0, NULL);
 138   }
 139   int len = _intrinsics->length();
 140   bool found = false;
 141   int index = intrinsic_insertion_index(cg->method(), cg->is_virtual(), found);
 142   assert(!found, "registering twice");
 143   _intrinsics->insert_before(index, cg);
 144   assert(find_intrinsic(cg->method(), cg->is_virtual()) == cg, "registration worked");
 145 }
 146 
 147 CallGenerator* Compile::find_intrinsic(ciMethod* m, bool is_virtual) {
 148   assert(m->is_loaded(), "don't try this on unloaded methods");
 149   if (_intrinsics != NULL) {
 150     bool found = false;
 151     int index = intrinsic_insertion_index(m, is_virtual, found);
 152      if (found) {
 153       return _intrinsics->at(index);
 154     }
 155   }
 156   // Lazily create intrinsics for intrinsic IDs well-known in the runtime.
 157   if (m->intrinsic_id() != vmIntrinsics::_none &&
 158       m->intrinsic_id() <= vmIntrinsics::LAST_COMPILER_INLINE) {
 159     CallGenerator* cg = make_vm_intrinsic(m, is_virtual);
 160     if (cg != NULL) {
 161       // Save it for next time:
 162       register_intrinsic(cg);
 163       return cg;
 164     } else {
 165       gather_intrinsic_statistics(m->intrinsic_id(), is_virtual, _intrinsic_disabled);
 166     }
 167   }
 168   return NULL;
 169 }
 170 
 171 // Compile:: register_library_intrinsics and make_vm_intrinsic are defined
 172 // in library_call.cpp.
 173 
 174 
 175 #ifndef PRODUCT
 176 // statistics gathering...
 177 
 178 juint  Compile::_intrinsic_hist_count[vmIntrinsics::ID_LIMIT] = {0};
 179 jubyte Compile::_intrinsic_hist_flags[vmIntrinsics::ID_LIMIT] = {0};
 180 
 181 bool Compile::gather_intrinsic_statistics(vmIntrinsics::ID id, bool is_virtual, int flags) {
 182   assert(id > vmIntrinsics::_none && id < vmIntrinsics::ID_LIMIT, "oob");
 183   int oflags = _intrinsic_hist_flags[id];
 184   assert(flags != 0, "what happened?");
 185   if (is_virtual) {
 186     flags |= _intrinsic_virtual;
 187   }
 188   bool changed = (flags != oflags);
 189   if ((flags & _intrinsic_worked) != 0) {
 190     juint count = (_intrinsic_hist_count[id] += 1);
 191     if (count == 1) {
 192       changed = true;           // first time
 193     }
 194     // increment the overall count also:
 195     _intrinsic_hist_count[vmIntrinsics::_none] += 1;
 196   }
 197   if (changed) {
 198     if (((oflags ^ flags) & _intrinsic_virtual) != 0) {
 199       // Something changed about the intrinsic's virtuality.
 200       if ((flags & _intrinsic_virtual) != 0) {
 201         // This is the first use of this intrinsic as a virtual call.
 202         if (oflags != 0) {
 203           // We already saw it as a non-virtual, so note both cases.
 204           flags |= _intrinsic_both;
 205         }
 206       } else if ((oflags & _intrinsic_both) == 0) {
 207         // This is the first use of this intrinsic as a non-virtual
 208         flags |= _intrinsic_both;
 209       }
 210     }
 211     _intrinsic_hist_flags[id] = (jubyte) (oflags | flags);
 212   }
 213   // update the overall flags also:
 214   _intrinsic_hist_flags[vmIntrinsics::_none] |= (jubyte) flags;
 215   return changed;
 216 }
 217 
 218 static char* format_flags(int flags, char* buf) {
 219   buf[0] = 0;
 220   if ((flags & Compile::_intrinsic_worked) != 0)    strcat(buf, ",worked");
 221   if ((flags & Compile::_intrinsic_failed) != 0)    strcat(buf, ",failed");
 222   if ((flags & Compile::_intrinsic_disabled) != 0)  strcat(buf, ",disabled");
 223   if ((flags & Compile::_intrinsic_virtual) != 0)   strcat(buf, ",virtual");
 224   if ((flags & Compile::_intrinsic_both) != 0)      strcat(buf, ",nonvirtual");
 225   if (buf[0] == 0)  strcat(buf, ",");
 226   assert(buf[0] == ',', "must be");
 227   return &buf[1];
 228 }
 229 
 230 void Compile::print_intrinsic_statistics() {
 231   char flagsbuf[100];
 232   ttyLocker ttyl;
 233   if (xtty != NULL)  xtty->head("statistics type='intrinsic'");
 234   tty->print_cr("Compiler intrinsic usage:");
 235   juint total = _intrinsic_hist_count[vmIntrinsics::_none];
 236   if (total == 0)  total = 1;  // avoid div0 in case of no successes
 237   #define PRINT_STAT_LINE(name, c, f) \
 238     tty->print_cr("  %4d (%4.1f%%) %s (%s)", (int)(c), ((c) * 100.0) / total, name, f);
 239   for (int index = 1 + (int)vmIntrinsics::_none; index < (int)vmIntrinsics::ID_LIMIT; index++) {
 240     vmIntrinsics::ID id = (vmIntrinsics::ID) index;
 241     int   flags = _intrinsic_hist_flags[id];
 242     juint count = _intrinsic_hist_count[id];
 243     if ((flags | count) != 0) {
 244       PRINT_STAT_LINE(vmIntrinsics::name_at(id), count, format_flags(flags, flagsbuf));
 245     }
 246   }
 247   PRINT_STAT_LINE("total", total, format_flags(_intrinsic_hist_flags[vmIntrinsics::_none], flagsbuf));
 248   if (xtty != NULL)  xtty->tail("statistics");
 249 }
 250 
 251 void Compile::print_statistics() {
 252   { ttyLocker ttyl;
 253     if (xtty != NULL)  xtty->head("statistics type='opto'");
 254     Parse::print_statistics();
 255     PhaseCCP::print_statistics();
 256     PhaseRegAlloc::print_statistics();
 257     Scheduling::print_statistics();
 258     PhasePeephole::print_statistics();
 259     PhaseIdealLoop::print_statistics();
 260     if (xtty != NULL)  xtty->tail("statistics");
 261   }
 262   if (_intrinsic_hist_flags[vmIntrinsics::_none] != 0) {
 263     // put this under its own <statistics> element.
 264     print_intrinsic_statistics();
 265   }
 266 }
 267 #endif //PRODUCT
 268 
 269 // Support for bundling info
 270 Bundle* Compile::node_bundling(const Node *n) {
 271   assert(valid_bundle_info(n), "oob");
 272   return &_node_bundling_base[n->_idx];
 273 }
 274 
 275 bool Compile::valid_bundle_info(const Node *n) {
 276   return (_node_bundling_limit > n->_idx);
 277 }
 278 
 279 
 280 void Compile::gvn_replace_by(Node* n, Node* nn) {
 281   for (DUIterator_Last imin, i = n->last_outs(imin); i >= imin; ) {
 282     Node* use = n->last_out(i);
 283     bool is_in_table = initial_gvn()->hash_delete(use);
 284     uint uses_found = 0;
 285     for (uint j = 0; j < use->len(); j++) {
 286       if (use->in(j) == n) {
 287         if (j < use->req())
 288           use->set_req(j, nn);
 289         else
 290           use->set_prec(j, nn);
 291         uses_found++;
 292       }
 293     }
 294     if (is_in_table) {
 295       // reinsert into table
 296       initial_gvn()->hash_find_insert(use);
 297     }
 298     record_for_igvn(use);
 299     i -= uses_found;    // we deleted 1 or more copies of this edge
 300   }
 301 }
 302 
 303 
 304 static inline bool not_a_node(const Node* n) {
 305   if (n == NULL)                   return true;
 306   if (((intptr_t)n & 1) != 0)      return true;  // uninitialized, etc.
 307   if (*(address*)n == badAddress)  return true;  // kill by Node::destruct
 308   return false;
 309 }
 310 
 311 // Identify all nodes that are reachable from below, useful.
 312 // Use breadth-first pass that records state in a Unique_Node_List,
 313 // recursive traversal is slower.
 314 void Compile::identify_useful_nodes(Unique_Node_List &useful) {
 315   int estimated_worklist_size = live_nodes();
 316   useful.map( estimated_worklist_size, NULL );  // preallocate space
 317 
 318   // Initialize worklist
 319   if (root() != NULL)     { useful.push(root()); }
 320   // If 'top' is cached, declare it useful to preserve cached node
 321   if( cached_top_node() ) { useful.push(cached_top_node()); }
 322 
 323   // Push all useful nodes onto the list, breadthfirst
 324   for( uint next = 0; next < useful.size(); ++next ) {
 325     assert( next < unique(), "Unique useful nodes < total nodes");
 326     Node *n  = useful.at(next);
 327     uint max = n->len();
 328     for( uint i = 0; i < max; ++i ) {
 329       Node *m = n->in(i);
 330       if (not_a_node(m))  continue;
 331       useful.push(m);
 332     }
 333   }
 334 }
 335 
 336 // Update dead_node_list with any missing dead nodes using useful
 337 // list. Consider all non-useful nodes to be useless i.e., dead nodes.
 338 void Compile::update_dead_node_list(Unique_Node_List &useful) {
 339   uint max_idx = unique();
 340   VectorSet& useful_node_set = useful.member_set();
 341 
 342   for (uint node_idx = 0; node_idx < max_idx; node_idx++) {
 343     // If node with index node_idx is not in useful set,
 344     // mark it as dead in dead node list.
 345     if (! useful_node_set.test(node_idx) ) {
 346       record_dead_node(node_idx);
 347     }
 348   }
 349 }
 350 
 351 void Compile::remove_useless_late_inlines(GrowableArray<CallGenerator*>* inlines, Unique_Node_List &useful) {
 352   int shift = 0;
 353   for (int i = 0; i < inlines->length(); i++) {
 354     CallGenerator* cg = inlines->at(i);
 355     CallNode* call = cg->call_node();
 356     if (shift > 0) {
 357       inlines->at_put(i-shift, cg);
 358     }
 359     if (!useful.member(call)) {
 360       shift++;
 361     }
 362   }
 363   inlines->trunc_to(inlines->length()-shift);
 364 }
 365 
 366 // Disconnect all useless nodes by disconnecting those at the boundary.
 367 void Compile::remove_useless_nodes(Unique_Node_List &useful) {
 368   uint next = 0;
 369   while (next < useful.size()) {
 370     Node *n = useful.at(next++);
 371     if (n->is_SafePoint()) {
 372       // We're done with a parsing phase. Replaced nodes are not valid
 373       // beyond that point.
 374       n->as_SafePoint()->delete_replaced_nodes();
 375     }
 376     // Use raw traversal of out edges since this code removes out edges
 377     int max = n->outcnt();
 378     for (int j = 0; j < max; ++j) {
 379       Node* child = n->raw_out(j);
 380       if (! useful.member(child)) {
 381         assert(!child->is_top() || child != top(),
 382                "If top is cached in Compile object it is in useful list");
 383         // Only need to remove this out-edge to the useless node
 384         n->raw_del_out(j);
 385         --j;
 386         --max;
 387       }
 388     }
 389     if (n->outcnt() == 1 && n->has_special_unique_user()) {
 390       record_for_igvn(n->unique_out());
 391     }
 392   }
 393   // Remove useless macro and predicate opaq nodes
 394   for (int i = C->macro_count()-1; i >= 0; i--) {
 395     Node* n = C->macro_node(i);
 396     if (!useful.member(n)) {
 397       remove_macro_node(n);
 398     }
 399   }
 400   // Remove useless CastII nodes with range check dependency
 401   for (int i = range_check_cast_count() - 1; i >= 0; i--) {
 402     Node* cast = range_check_cast_node(i);
 403     if (!useful.member(cast)) {
 404       remove_range_check_cast(cast);
 405     }
 406   }
 407   // Remove useless expensive nodes
 408   for (int i = C->expensive_count()-1; i >= 0; i--) {
 409     Node* n = C->expensive_node(i);
 410     if (!useful.member(n)) {
 411       remove_expensive_node(n);
 412     }
 413   }
 414   // Remove useless Opaque4 nodes
 415   for (int i = opaque4_count() - 1; i >= 0; i--) {
 416     Node* opaq = opaque4_node(i);
 417     if (!useful.member(opaq)) {
 418       remove_opaque4_node(opaq);
 419     }
 420   }
 421   // Remove useless value type nodes
 422   if (_value_type_nodes != NULL) {
 423     _value_type_nodes->remove_useless_nodes(useful.member_set());
 424   }
 425   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 426   bs->eliminate_useless_gc_barriers(useful, this);
 427   // clean up the late inline lists
 428   remove_useless_late_inlines(&_string_late_inlines, useful);
 429   remove_useless_late_inlines(&_boxing_late_inlines, useful);
 430   remove_useless_late_inlines(&_late_inlines, useful);
 431   debug_only(verify_graph_edges(true/*check for no_dead_code*/);)
 432 }
 433 
 434 //------------------------------frame_size_in_words-----------------------------
 435 // frame_slots in units of words
 436 int Compile::frame_size_in_words() const {
 437   // shift is 0 in LP32 and 1 in LP64
 438   const int shift = (LogBytesPerWord - LogBytesPerInt);
 439   int words = _frame_slots >> shift;
 440   assert( words << shift == _frame_slots, "frame size must be properly aligned in LP64" );
 441   return words;
 442 }
 443 
 444 // To bang the stack of this compiled method we use the stack size
 445 // that the interpreter would need in case of a deoptimization. This
 446 // removes the need to bang the stack in the deoptimization blob which
 447 // in turn simplifies stack overflow handling.
 448 int Compile::bang_size_in_bytes() const {
 449   return MAX2(frame_size_in_bytes() + os::extra_bang_size_in_bytes(), _interpreter_frame_size);
 450 }
 451 
 452 // ============================================================================
 453 //------------------------------CompileWrapper---------------------------------
 454 class CompileWrapper : public StackObj {
 455   Compile *const _compile;
 456  public:
 457   CompileWrapper(Compile* compile);
 458 
 459   ~CompileWrapper();
 460 };
 461 
 462 CompileWrapper::CompileWrapper(Compile* compile) : _compile(compile) {
 463   // the Compile* pointer is stored in the current ciEnv:
 464   ciEnv* env = compile->env();
 465   assert(env == ciEnv::current(), "must already be a ciEnv active");
 466   assert(env->compiler_data() == NULL, "compile already active?");
 467   env->set_compiler_data(compile);
 468   assert(compile == Compile::current(), "sanity");
 469 
 470   compile->set_type_dict(NULL);
 471   compile->set_clone_map(new Dict(cmpkey, hashkey, _compile->comp_arena()));
 472   compile->clone_map().set_clone_idx(0);
 473   compile->set_type_hwm(NULL);
 474   compile->set_type_last_size(0);
 475   compile->set_last_tf(NULL, NULL);
 476   compile->set_indexSet_arena(NULL);
 477   compile->set_indexSet_free_block_list(NULL);
 478   compile->init_type_arena();
 479   Type::Initialize(compile);
 480   _compile->set_scratch_buffer_blob(NULL);
 481   _compile->begin_method();
 482   _compile->clone_map().set_debug(_compile->has_method() && _compile->directive()->CloneMapDebugOption);
 483 }
 484 CompileWrapper::~CompileWrapper() {
 485   _compile->end_method();
 486   if (_compile->scratch_buffer_blob() != NULL)
 487     BufferBlob::free(_compile->scratch_buffer_blob());
 488   _compile->env()->set_compiler_data(NULL);
 489 }
 490 
 491 
 492 //----------------------------print_compile_messages---------------------------
 493 void Compile::print_compile_messages() {
 494 #ifndef PRODUCT
 495   // Check if recompiling
 496   if (_subsume_loads == false && PrintOpto) {
 497     // Recompiling without allowing machine instructions to subsume loads
 498     tty->print_cr("*********************************************************");
 499     tty->print_cr("** Bailout: Recompile without subsuming loads          **");
 500     tty->print_cr("*********************************************************");
 501   }
 502   if (_do_escape_analysis != DoEscapeAnalysis && PrintOpto) {
 503     // Recompiling without escape analysis
 504     tty->print_cr("*********************************************************");
 505     tty->print_cr("** Bailout: Recompile without escape analysis          **");
 506     tty->print_cr("*********************************************************");
 507   }
 508   if (_eliminate_boxing != EliminateAutoBox && PrintOpto) {
 509     // Recompiling without boxing elimination
 510     tty->print_cr("*********************************************************");
 511     tty->print_cr("** Bailout: Recompile without boxing elimination       **");
 512     tty->print_cr("*********************************************************");
 513   }
 514   if (C->directive()->BreakAtCompileOption) {
 515     // Open the debugger when compiling this method.
 516     tty->print("### Breaking when compiling: ");
 517     method()->print_short_name();
 518     tty->cr();
 519     BREAKPOINT;
 520   }
 521 
 522   if( PrintOpto ) {
 523     if (is_osr_compilation()) {
 524       tty->print("[OSR]%3d", _compile_id);
 525     } else {
 526       tty->print("%3d", _compile_id);
 527     }
 528   }
 529 #endif
 530 }
 531 
 532 
 533 //-----------------------init_scratch_buffer_blob------------------------------
 534 // Construct a temporary BufferBlob and cache it for this compile.
 535 void Compile::init_scratch_buffer_blob(int const_size) {
 536   // If there is already a scratch buffer blob allocated and the
 537   // constant section is big enough, use it.  Otherwise free the
 538   // current and allocate a new one.
 539   BufferBlob* blob = scratch_buffer_blob();
 540   if ((blob != NULL) && (const_size <= _scratch_const_size)) {
 541     // Use the current blob.
 542   } else {
 543     if (blob != NULL) {
 544       BufferBlob::free(blob);
 545     }
 546 
 547     ResourceMark rm;
 548     _scratch_const_size = const_size;
 549     int size = C2Compiler::initial_code_buffer_size(const_size);
 550 #ifdef ASSERT
 551     if (C->has_scalarized_args()) {
 552       // Oop verification for loading object fields from scalarized value types in the new entry point requires lots of space
 553       size += 5120;
 554     }
 555 #endif
 556     blob = BufferBlob::create("Compile::scratch_buffer", size);
 557     // Record the buffer blob for next time.
 558     set_scratch_buffer_blob(blob);
 559     // Have we run out of code space?
 560     if (scratch_buffer_blob() == NULL) {
 561       // Let CompilerBroker disable further compilations.
 562       record_failure("Not enough space for scratch buffer in CodeCache");
 563       return;
 564     }
 565   }
 566 
 567   // Initialize the relocation buffers
 568   relocInfo* locs_buf = (relocInfo*) blob->content_end() - MAX_locs_size;
 569   set_scratch_locs_memory(locs_buf);
 570 }
 571 
 572 
 573 //-----------------------scratch_emit_size-------------------------------------
 574 // Helper function that computes size by emitting code
 575 uint Compile::scratch_emit_size(const Node* n) {
 576   // Start scratch_emit_size section.
 577   set_in_scratch_emit_size(true);
 578 
 579   // Emit into a trash buffer and count bytes emitted.
 580   // This is a pretty expensive way to compute a size,
 581   // but it works well enough if seldom used.
 582   // All common fixed-size instructions are given a size
 583   // method by the AD file.
 584   // Note that the scratch buffer blob and locs memory are
 585   // allocated at the beginning of the compile task, and
 586   // may be shared by several calls to scratch_emit_size.
 587   // The allocation of the scratch buffer blob is particularly
 588   // expensive, since it has to grab the code cache lock.
 589   BufferBlob* blob = this->scratch_buffer_blob();
 590   assert(blob != NULL, "Initialize BufferBlob at start");
 591   assert(blob->size() > MAX_inst_size, "sanity");
 592   relocInfo* locs_buf = scratch_locs_memory();
 593   address blob_begin = blob->content_begin();
 594   address blob_end   = (address)locs_buf;
 595   assert(blob->contains(blob_end), "sanity");
 596   CodeBuffer buf(blob_begin, blob_end - blob_begin);
 597   buf.initialize_consts_size(_scratch_const_size);
 598   buf.initialize_stubs_size(MAX_stubs_size);
 599   assert(locs_buf != NULL, "sanity");
 600   int lsize = MAX_locs_size / 3;
 601   buf.consts()->initialize_shared_locs(&locs_buf[lsize * 0], lsize);
 602   buf.insts()->initialize_shared_locs( &locs_buf[lsize * 1], lsize);
 603   buf.stubs()->initialize_shared_locs( &locs_buf[lsize * 2], lsize);
 604   // Mark as scratch buffer.
 605   buf.consts()->set_scratch_emit();
 606   buf.insts()->set_scratch_emit();
 607   buf.stubs()->set_scratch_emit();
 608 
 609   // Do the emission.
 610 
 611   Label fakeL; // Fake label for branch instructions.
 612   Label*   saveL = NULL;
 613   uint save_bnum = 0;
 614   bool is_branch = n->is_MachBranch();
 615   if (is_branch) {
 616     MacroAssembler masm(&buf);
 617     masm.bind(fakeL);
 618     n->as_MachBranch()->save_label(&saveL, &save_bnum);
 619     n->as_MachBranch()->label_set(&fakeL, 0);
 620   } else if (n->is_MachProlog()) {
 621     saveL = ((MachPrologNode*)n)->_verified_entry;
 622     ((MachPrologNode*)n)->_verified_entry = &fakeL;
 623   }
 624   n->emit(buf, this->regalloc());
 625 
 626   // Emitting into the scratch buffer should not fail
 627   assert (!failing(), "Must not have pending failure. Reason is: %s", failure_reason());
 628 
 629   // Restore label.
 630   if (is_branch) {
 631     n->as_MachBranch()->label_set(saveL, save_bnum);
 632   } else if (n->is_MachProlog()) {
 633     ((MachPrologNode*)n)->_verified_entry = saveL;
 634   }
 635 
 636   // End scratch_emit_size section.
 637   set_in_scratch_emit_size(false);
 638 
 639   return buf.insts_size();
 640 }
 641 
 642 
 643 // ============================================================================
 644 //------------------------------Compile standard-------------------------------
 645 debug_only( int Compile::_debug_idx = 100000; )
 646 
 647 // Compile a method.  entry_bci is -1 for normal compilations and indicates
 648 // the continuation bci for on stack replacement.
 649 
 650 
 651 Compile::Compile( ciEnv* ci_env, C2Compiler* compiler, ciMethod* target, int osr_bci,
 652                   bool subsume_loads, bool do_escape_analysis, bool eliminate_boxing, DirectiveSet* directive)
 653                 : Phase(Compiler),
 654                   _compile_id(ci_env->compile_id()),
 655                   _save_argument_registers(false),
 656                   _subsume_loads(subsume_loads),
 657                   _do_escape_analysis(do_escape_analysis),
 658                   _eliminate_boxing(eliminate_boxing),
 659                   _method(target),
 660                   _entry_bci(osr_bci),
 661                   _stub_function(NULL),
 662                   _stub_name(NULL),
 663                   _stub_entry_point(NULL),
 664                   _max_node_limit(MaxNodeLimit),
 665                   _orig_pc_slot(0),
 666                   _orig_pc_slot_offset_in_bytes(0),
 667                   _sp_inc_slot(0),
 668                   _sp_inc_slot_offset_in_bytes(0),
 669                   _inlining_progress(false),
 670                   _inlining_incrementally(false),
 671                   _has_reserved_stack_access(target->has_reserved_stack_access()),
 672 #ifndef PRODUCT
 673                   _trace_opto_output(directive->TraceOptoOutputOption),
 674 #endif
 675                   _has_method_handle_invokes(false),
 676                   _comp_arena(mtCompiler),
 677                   _barrier_set_state(BarrierSet::barrier_set()->barrier_set_c2()->create_barrier_state(comp_arena())),
 678                   _env(ci_env),
 679                   _directive(directive),
 680                   _log(ci_env->log()),
 681                   _failure_reason(NULL),
 682                   _congraph(NULL),
 683 #ifndef PRODUCT
 684                   _printer(IdealGraphPrinter::printer()),
 685 #endif
 686                   _dead_node_list(comp_arena()),
 687                   _dead_node_count(0),
 688                   _node_arena(mtCompiler),
 689                   _old_arena(mtCompiler),
 690                   _mach_constant_base_node(NULL),
 691                   _Compile_types(mtCompiler),
 692                   _initial_gvn(NULL),
 693                   _for_igvn(NULL),
 694                   _warm_calls(NULL),
 695                   _late_inlines(comp_arena(), 2, 0, NULL),
 696                   _string_late_inlines(comp_arena(), 2, 0, NULL),
 697                   _boxing_late_inlines(comp_arena(), 2, 0, NULL),
 698                   _late_inlines_pos(0),
 699                   _number_of_mh_late_inlines(0),
 700                   _print_inlining_stream(NULL),
 701                   _print_inlining_list(NULL),
 702                   _print_inlining_idx(0),
 703                   _print_inlining_output(NULL),
 704                   _replay_inline_data(NULL),
 705                   _java_calls(0),
 706                   _inner_loops(0),
 707                   _interpreter_frame_size(0),
 708                   _node_bundling_limit(0),
 709                   _node_bundling_base(NULL),
 710                   _code_buffer("Compile::Fill_buffer"),
 711                   _scratch_const_size(-1),
 712                   _in_scratch_emit_size(false)
 713 #ifndef PRODUCT
 714                   , _in_dump_cnt(0)
 715 #endif
 716 {
 717   C = this;
 718 #ifndef PRODUCT
 719   if (_printer != NULL) {
 720     _printer->set_compile(this);
 721   }
 722 #endif
 723   CompileWrapper cw(this);
 724 
 725   if (CITimeVerbose) {
 726     tty->print(" ");
 727     target->holder()->name()->print();
 728     tty->print(".");
 729     target->print_short_name();
 730     tty->print("  ");
 731   }
 732   TraceTime t1("Total compilation time", &_t_totalCompilation, CITime, CITimeVerbose);
 733   TraceTime t2(NULL, &_t_methodCompilation, CITime, false);
 734 
 735 #ifndef PRODUCT
 736   bool print_opto_assembly = directive->PrintOptoAssemblyOption;
 737   if (!print_opto_assembly) {
 738     bool print_assembly = directive->PrintAssemblyOption;
 739     if (print_assembly && !Disassembler::can_decode()) {
 740       tty->print_cr("PrintAssembly request changed to PrintOptoAssembly");
 741       print_opto_assembly = true;
 742     }
 743   }
 744   set_print_assembly(print_opto_assembly);
 745   set_parsed_irreducible_loop(false);
 746 
 747   if (directive->ReplayInlineOption) {
 748     _replay_inline_data = ciReplay::load_inline_data(method(), entry_bci(), ci_env->comp_level());
 749   }
 750 #endif
 751   set_print_inlining(directive->PrintInliningOption || PrintOptoInlining);
 752   set_print_intrinsics(directive->PrintIntrinsicsOption);
 753   set_has_irreducible_loop(true); // conservative until build_loop_tree() reset it
 754 
 755   if (ProfileTraps RTM_OPT_ONLY( || UseRTMLocking )) {
 756     // Make sure the method being compiled gets its own MDO,
 757     // so we can at least track the decompile_count().
 758     // Need MDO to record RTM code generation state.
 759     method()->ensure_method_data();
 760   }
 761 
 762   Init(::AliasLevel);
 763 
 764 
 765   print_compile_messages();
 766 
 767   _ilt = InlineTree::build_inline_tree_root();
 768 
 769   // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
 770   assert(num_alias_types() >= AliasIdxRaw, "");
 771 
 772 #define MINIMUM_NODE_HASH  1023
 773   // Node list that Iterative GVN will start with
 774   Unique_Node_List for_igvn(comp_arena());
 775   set_for_igvn(&for_igvn);
 776 
 777   // GVN that will be run immediately on new nodes
 778   uint estimated_size = method()->code_size()*4+64;
 779   estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
 780   PhaseGVN gvn(node_arena(), estimated_size);
 781   set_initial_gvn(&gvn);
 782 
 783   print_inlining_init();
 784   { // Scope for timing the parser
 785     TracePhase tp("parse", &timers[_t_parser]);
 786 
 787     // Put top into the hash table ASAP.
 788     initial_gvn()->transform_no_reclaim(top());
 789 
 790     // Set up tf(), start(), and find a CallGenerator.
 791     CallGenerator* cg = NULL;
 792     if (is_osr_compilation()) {
 793       const TypeTuple *domain = StartOSRNode::osr_domain();
 794       const TypeTuple *range = TypeTuple::make_range(method()->signature());
 795       init_tf(TypeFunc::make(domain, range));
 796       StartNode* s = new StartOSRNode(root(), domain);
 797       initial_gvn()->set_type_bottom(s);
 798       init_start(s);
 799       cg = CallGenerator::for_osr(method(), entry_bci());
 800     } else {
 801       // Normal case.
 802       init_tf(TypeFunc::make(method()));
 803       StartNode* s = new StartNode(root(), tf()->domain_cc());
 804       initial_gvn()->set_type_bottom(s);
 805       init_start(s);
 806       if (method()->intrinsic_id() == vmIntrinsics::_Reference_get) {
 807         // With java.lang.ref.reference.get() we must go through the
 808         // intrinsic - even when get() is the root
 809         // method of the compile - so that, if necessary, the value in
 810         // the referent field of the reference object gets recorded by
 811         // the pre-barrier code.
 812         cg = find_intrinsic(method(), false);
 813       }
 814       if (cg == NULL) {
 815         float past_uses = method()->interpreter_invocation_count();
 816         float expected_uses = past_uses;
 817         cg = CallGenerator::for_inline(method(), expected_uses);
 818       }
 819     }
 820     if (failing())  return;
 821     if (cg == NULL) {
 822       record_method_not_compilable("cannot parse method");
 823       return;
 824     }
 825     JVMState* jvms = build_start_state(start(), tf());
 826     if ((jvms = cg->generate(jvms)) == NULL) {
 827       if (!failure_reason_is(C2Compiler::retry_class_loading_during_parsing())) {
 828         record_method_not_compilable("method parse failed");
 829       }
 830       return;
 831     }
 832     GraphKit kit(jvms);
 833 
 834     if (!kit.stopped()) {
 835       // Accept return values, and transfer control we know not where.
 836       // This is done by a special, unique ReturnNode bound to root.
 837       return_values(kit.jvms());
 838     }
 839 
 840     if (kit.has_exceptions()) {
 841       // Any exceptions that escape from this call must be rethrown
 842       // to whatever caller is dynamically above us on the stack.
 843       // This is done by a special, unique RethrowNode bound to root.
 844       rethrow_exceptions(kit.transfer_exceptions_into_jvms());
 845     }
 846 
 847     assert(IncrementalInline || (_late_inlines.length() == 0 && !has_mh_late_inlines()), "incremental inlining is off");
 848 
 849     if (_late_inlines.length() == 0 && !has_mh_late_inlines() && !failing() && has_stringbuilder()) {
 850       inline_string_calls(true);
 851     }
 852 
 853     if (failing())  return;
 854 
 855     print_method(PHASE_BEFORE_REMOVEUSELESS, 3);
 856 
 857     // Remove clutter produced by parsing.
 858     if (!failing()) {
 859       ResourceMark rm;
 860       PhaseRemoveUseless pru(initial_gvn(), &for_igvn);
 861     }
 862   }
 863 
 864   // Note:  Large methods are capped off in do_one_bytecode().
 865   if (failing())  return;
 866 
 867   // After parsing, node notes are no longer automagic.
 868   // They must be propagated by register_new_node_with_optimizer(),
 869   // clone(), or the like.
 870   set_default_node_notes(NULL);
 871 
 872   for (;;) {
 873     int successes = Inline_Warm();
 874     if (failing())  return;
 875     if (successes == 0)  break;
 876   }
 877 
 878   // Drain the list.
 879   Finish_Warm();
 880 #ifndef PRODUCT
 881   if (_printer && _printer->should_print(1)) {
 882     _printer->print_inlining();
 883   }
 884 #endif
 885 
 886   if (failing())  return;
 887   NOT_PRODUCT( verify_graph_edges(); )
 888 
 889   // Now optimize
 890   Optimize();
 891   if (failing())  return;
 892   NOT_PRODUCT( verify_graph_edges(); )
 893 
 894 #ifndef PRODUCT
 895   if (PrintIdeal) {
 896     ttyLocker ttyl;  // keep the following output all in one block
 897     // This output goes directly to the tty, not the compiler log.
 898     // To enable tools to match it up with the compilation activity,
 899     // be sure to tag this tty output with the compile ID.
 900     if (xtty != NULL) {
 901       xtty->head("ideal compile_id='%d'%s", compile_id(),
 902                  is_osr_compilation()    ? " compile_kind='osr'" :
 903                  "");
 904     }
 905     root()->dump(9999);
 906     if (xtty != NULL) {
 907       xtty->tail("ideal");
 908     }
 909   }
 910 #endif
 911 
 912 #ifdef ASSERT
 913   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 914   bs->verify_gc_barriers(this, BarrierSetC2::BeforeCodeGen);
 915 #endif
 916 
 917   // Dump compilation data to replay it.
 918   if (directive->DumpReplayOption) {
 919     env()->dump_replay_data(_compile_id);
 920   }
 921   if (directive->DumpInlineOption && (ilt() != NULL)) {
 922     env()->dump_inline_data(_compile_id);
 923   }
 924 
 925   // Now that we know the size of all the monitors we can add a fixed slot
 926   // for the original deopt pc.
 927 
 928   _orig_pc_slot = fixed_slots();
 929   int next_slot = _orig_pc_slot + (sizeof(address) / VMRegImpl::stack_slot_size);
 930 
 931   if (method()->get_Method()->needs_stack_repair()) {
 932     // One extra slot for the special stack increment value
 933     _sp_inc_slot = next_slot;
 934     next_slot += 2;
 935   }
 936 
 937   set_fixed_slots(next_slot);
 938 
 939   // Compute when to use implicit null checks. Used by matching trap based
 940   // nodes and NullCheck optimization.
 941   set_allowed_deopt_reasons();
 942 
 943   // Now generate code
 944   Code_Gen();
 945   if (failing())  return;
 946 
 947   // Check if we want to skip execution of all compiled code.
 948   {
 949 #ifndef PRODUCT
 950     if (OptoNoExecute) {
 951       record_method_not_compilable("+OptoNoExecute");  // Flag as failed
 952       return;
 953     }
 954 #endif
 955     TracePhase tp("install_code", &timers[_t_registerMethod]);
 956 
 957     if (is_osr_compilation()) {
 958       _code_offsets.set_value(CodeOffsets::Verified_Entry, 0);
 959       _code_offsets.set_value(CodeOffsets::OSR_Entry, _first_block_size);
 960     } else {
 961       _code_offsets.set_value(CodeOffsets::Verified_Entry, _first_block_size);
 962       if (_code_offsets.value(CodeOffsets::Verified_Value_Entry) == -1) {
 963         _code_offsets.set_value(CodeOffsets::Verified_Value_Entry, _first_block_size);
 964       }
 965       if (_code_offsets.value(CodeOffsets::Entry) == -1) {
 966         // We emitted a value type entry point, adjust normal entry
 967         _code_offsets.set_value(CodeOffsets::Entry, _first_block_size);
 968       }
 969       _code_offsets.set_value(CodeOffsets::OSR_Entry, 0);
 970     }
 971 
 972     env()->register_method(_method, _entry_bci,
 973                            &_code_offsets,
 974                            _orig_pc_slot_offset_in_bytes,
 975                            code_buffer(),
 976                            frame_size_in_words(), _oop_map_set,
 977                            &_handler_table, &_inc_table,
 978                            compiler,
 979                            has_unsafe_access(),
 980                            SharedRuntime::is_wide_vector(max_vector_size()),
 981                            rtm_state()
 982                            );
 983 
 984     if (log() != NULL) // Print code cache state into compiler log
 985       log()->code_cache_state();
 986   }
 987 }
 988 
 989 //------------------------------Compile----------------------------------------
 990 // Compile a runtime stub
 991 Compile::Compile( ciEnv* ci_env,
 992                   TypeFunc_generator generator,
 993                   address stub_function,
 994                   const char *stub_name,
 995                   int is_fancy_jump,
 996                   bool pass_tls,
 997                   bool save_arg_registers,
 998                   bool return_pc,
 999                   DirectiveSet* directive)
1000   : Phase(Compiler),
1001     _compile_id(0),
1002     _save_argument_registers(save_arg_registers),
1003     _subsume_loads(true),
1004     _do_escape_analysis(false),
1005     _eliminate_boxing(false),
1006     _method(NULL),
1007     _entry_bci(InvocationEntryBci),
1008     _stub_function(stub_function),
1009     _stub_name(stub_name),
1010     _stub_entry_point(NULL),
1011     _max_node_limit(MaxNodeLimit),
1012     _orig_pc_slot(0),
1013     _orig_pc_slot_offset_in_bytes(0),
1014     _sp_inc_slot(0),
1015     _sp_inc_slot_offset_in_bytes(0),
1016     _inlining_progress(false),
1017     _inlining_incrementally(false),
1018     _has_reserved_stack_access(false),
1019 #ifndef PRODUCT
1020     _trace_opto_output(directive->TraceOptoOutputOption),
1021 #endif
1022     _has_method_handle_invokes(false),
1023     _comp_arena(mtCompiler),
1024     _env(ci_env),
1025     _directive(directive),
1026     _log(ci_env->log()),
1027     _failure_reason(NULL),
1028     _congraph(NULL),
1029 #ifndef PRODUCT
1030     _printer(NULL),
1031 #endif
1032     _dead_node_list(comp_arena()),
1033     _dead_node_count(0),
1034     _node_arena(mtCompiler),
1035     _old_arena(mtCompiler),
1036     _mach_constant_base_node(NULL),
1037     _Compile_types(mtCompiler),
1038     _initial_gvn(NULL),
1039     _for_igvn(NULL),
1040     _warm_calls(NULL),
1041     _number_of_mh_late_inlines(0),
1042     _print_inlining_stream(NULL),
1043     _print_inlining_list(NULL),
1044     _print_inlining_idx(0),
1045     _print_inlining_output(NULL),
1046     _replay_inline_data(NULL),
1047     _java_calls(0),
1048     _inner_loops(0),
1049     _interpreter_frame_size(0),
1050     _node_bundling_limit(0),
1051     _node_bundling_base(NULL),
1052     _code_buffer("Compile::Fill_buffer"),
1053 #ifndef PRODUCT
1054     _in_dump_cnt(0),
1055 #endif
1056     _allowed_reasons(0) {
1057   C = this;
1058 
1059   TraceTime t1(NULL, &_t_totalCompilation, CITime, false);
1060   TraceTime t2(NULL, &_t_stubCompilation, CITime, false);
1061 
1062 #ifndef PRODUCT
1063   set_print_assembly(PrintFrameConverterAssembly);
1064   set_parsed_irreducible_loop(false);
1065 #endif
1066   set_has_irreducible_loop(false); // no loops
1067 
1068   CompileWrapper cw(this);
1069   Init(/*AliasLevel=*/ 0);
1070   init_tf((*generator)());
1071 
1072   {
1073     // The following is a dummy for the sake of GraphKit::gen_stub
1074     Unique_Node_List for_igvn(comp_arena());
1075     set_for_igvn(&for_igvn);  // not used, but some GraphKit guys push on this
1076     PhaseGVN gvn(Thread::current()->resource_area(),255);
1077     set_initial_gvn(&gvn);    // not significant, but GraphKit guys use it pervasively
1078     gvn.transform_no_reclaim(top());
1079 
1080     GraphKit kit;
1081     kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
1082   }
1083 
1084   NOT_PRODUCT( verify_graph_edges(); )
1085   Code_Gen();
1086   if (failing())  return;
1087 
1088 
1089   // Entry point will be accessed using compile->stub_entry_point();
1090   if (code_buffer() == NULL) {
1091     Matcher::soft_match_failure();
1092   } else {
1093     if (PrintAssembly && (WizardMode || Verbose))
1094       tty->print_cr("### Stub::%s", stub_name);
1095 
1096     if (!failing()) {
1097       assert(_fixed_slots == 0, "no fixed slots used for runtime stubs");
1098 
1099       // Make the NMethod
1100       // For now we mark the frame as never safe for profile stackwalking
1101       RuntimeStub *rs = RuntimeStub::new_runtime_stub(stub_name,
1102                                                       code_buffer(),
1103                                                       CodeOffsets::frame_never_safe,
1104                                                       // _code_offsets.value(CodeOffsets::Frame_Complete),
1105                                                       frame_size_in_words(),
1106                                                       _oop_map_set,
1107                                                       save_arg_registers);
1108       assert(rs != NULL && rs->is_runtime_stub(), "sanity check");
1109 
1110       _stub_entry_point = rs->entry_point();
1111     }
1112   }
1113 }
1114 
1115 //------------------------------Init-------------------------------------------
1116 // Prepare for a single compilation
1117 void Compile::Init(int aliaslevel) {
1118   _unique  = 0;
1119   _regalloc = NULL;
1120 
1121   _tf      = NULL;  // filled in later
1122   _top     = NULL;  // cached later
1123   _matcher = NULL;  // filled in later
1124   _cfg     = NULL;  // filled in later
1125 
1126   set_24_bit_selection_and_mode(Use24BitFP, false);
1127 
1128   _node_note_array = NULL;
1129   _default_node_notes = NULL;
1130   DEBUG_ONLY( _modified_nodes = NULL; ) // Used in Optimize()
1131 
1132   _immutable_memory = NULL; // filled in at first inquiry
1133 
1134   // Globally visible Nodes
1135   // First set TOP to NULL to give safe behavior during creation of RootNode
1136   set_cached_top_node(NULL);
1137   set_root(new RootNode());
1138   // Now that you have a Root to point to, create the real TOP
1139   set_cached_top_node( new ConNode(Type::TOP) );
1140   set_recent_alloc(NULL, NULL);
1141 
1142   // Create Debug Information Recorder to record scopes, oopmaps, etc.
1143   env()->set_oop_recorder(new OopRecorder(env()->arena()));
1144   env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
1145   env()->set_dependencies(new Dependencies(env()));
1146 
1147   _fixed_slots = 0;
1148   set_has_split_ifs(false);
1149   set_has_loops(has_method() && method()->has_loops()); // first approximation
1150   set_has_stringbuilder(false);
1151   set_has_boxed_value(false);
1152   _trap_can_recompile = false;  // no traps emitted yet
1153   _major_progress = true; // start out assuming good things will happen
1154   set_has_unsafe_access(false);
1155   set_max_vector_size(0);
1156   set_clear_upper_avx(false);  //false as default for clear upper bits of ymm registers
1157   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
1158   set_decompile_count(0);
1159 
1160   set_do_freq_based_layout(_directive->BlockLayoutByFrequencyOption);
1161   set_num_loop_opts(LoopOptsCount);
1162   set_do_inlining(Inline);
1163   set_max_inline_size(MaxInlineSize);
1164   set_freq_inline_size(FreqInlineSize);
1165   set_do_scheduling(OptoScheduling);
1166   set_do_count_invocations(false);
1167   set_do_method_data_update(false);
1168 
1169   set_do_vector_loop(false);
1170 
1171   if (AllowVectorizeOnDemand) {
1172     if (has_method() && (_directive->VectorizeOption || _directive->VectorizeDebugOption)) {
1173       set_do_vector_loop(true);
1174       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());})
1175     } else if (has_method() && method()->name() != 0 &&
1176                method()->intrinsic_id() == vmIntrinsics::_forEachRemaining) {
1177       set_do_vector_loop(true);
1178     }
1179   }
1180   set_use_cmove(UseCMoveUnconditionally /* || do_vector_loop()*/); //TODO: consider do_vector_loop() mandate use_cmove unconditionally
1181   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());})
1182 
1183   set_age_code(has_method() && method()->profile_aging());
1184   set_rtm_state(NoRTM); // No RTM lock eliding by default
1185   _max_node_limit = _directive->MaxNodeLimitOption;
1186 
1187 #if INCLUDE_RTM_OPT
1188   if (UseRTMLocking && has_method() && (method()->method_data_or_null() != NULL)) {
1189     int rtm_state = method()->method_data()->rtm_state();
1190     if (method_has_option("NoRTMLockEliding") || ((rtm_state & NoRTM) != 0)) {
1191       // Don't generate RTM lock eliding code.
1192       set_rtm_state(NoRTM);
1193     } else if (method_has_option("UseRTMLockEliding") || ((rtm_state & UseRTM) != 0) || !UseRTMDeopt) {
1194       // Generate RTM lock eliding code without abort ratio calculation code.
1195       set_rtm_state(UseRTM);
1196     } else if (UseRTMDeopt) {
1197       // Generate RTM lock eliding code and include abort ratio calculation
1198       // code if UseRTMDeopt is on.
1199       set_rtm_state(ProfileRTM);
1200     }
1201   }
1202 #endif
1203   if (debug_info()->recording_non_safepoints()) {
1204     set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
1205                         (comp_arena(), 8, 0, NULL));
1206     set_default_node_notes(Node_Notes::make(this));
1207   }
1208 
1209   // // -- Initialize types before each compile --
1210   // // Update cached type information
1211   // if( _method && _method->constants() )
1212   //   Type::update_loaded_types(_method, _method->constants());
1213 
1214   // Init alias_type map.
1215   if (!_do_escape_analysis && aliaslevel == 3)
1216     aliaslevel = 2;  // No unique types without escape analysis
1217   _AliasLevel = aliaslevel;
1218   const int grow_ats = 16;
1219   _max_alias_types = grow_ats;
1220   _alias_types   = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
1221   AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType,  grow_ats);
1222   Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
1223   {
1224     for (int i = 0; i < grow_ats; i++)  _alias_types[i] = &ats[i];
1225   }
1226   // Initialize the first few types.
1227   _alias_types[AliasIdxTop]->Init(AliasIdxTop, NULL);
1228   _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
1229   _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
1230   _num_alias_types = AliasIdxRaw+1;
1231   // Zero out the alias type cache.
1232   Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
1233   // A NULL adr_type hits in the cache right away.  Preload the right answer.
1234   probe_alias_cache(NULL)->_index = AliasIdxTop;
1235 
1236   _intrinsics = NULL;
1237   _macro_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1238   _predicate_opaqs = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1239   _expensive_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1240   _range_check_casts = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1241   _opaque4_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1242   _value_type_nodes = new (comp_arena()) Unique_Node_List(comp_arena());
1243   register_library_intrinsics();
1244 }
1245 
1246 //---------------------------init_start----------------------------------------
1247 // Install the StartNode on this compile object.
1248 void Compile::init_start(StartNode* s) {
1249   if (failing())
1250     return; // already failing
1251   assert(s == start(), "");
1252 }
1253 
1254 /**
1255  * Return the 'StartNode'. We must not have a pending failure, since the ideal graph
1256  * can be in an inconsistent state, i.e., we can get segmentation faults when traversing
1257  * the ideal graph.
1258  */
1259 StartNode* Compile::start() const {
1260   assert (!failing(), "Must not have pending failure. Reason is: %s", failure_reason());
1261   for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
1262     Node* start = root()->fast_out(i);
1263     if (start->is_Start()) {
1264       return start->as_Start();
1265     }
1266   }
1267   fatal("Did not find Start node!");
1268   return NULL;
1269 }
1270 
1271 //-------------------------------immutable_memory-------------------------------------
1272 // Access immutable memory
1273 Node* Compile::immutable_memory() {
1274   if (_immutable_memory != NULL) {
1275     return _immutable_memory;
1276   }
1277   StartNode* s = start();
1278   for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
1279     Node *p = s->fast_out(i);
1280     if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
1281       _immutable_memory = p;
1282       return _immutable_memory;
1283     }
1284   }
1285   ShouldNotReachHere();
1286   return NULL;
1287 }
1288 
1289 //----------------------set_cached_top_node------------------------------------
1290 // Install the cached top node, and make sure Node::is_top works correctly.
1291 void Compile::set_cached_top_node(Node* tn) {
1292   if (tn != NULL)  verify_top(tn);
1293   Node* old_top = _top;
1294   _top = tn;
1295   // Calling Node::setup_is_top allows the nodes the chance to adjust
1296   // their _out arrays.
1297   if (_top != NULL)     _top->setup_is_top();
1298   if (old_top != NULL)  old_top->setup_is_top();
1299   assert(_top == NULL || top()->is_top(), "");
1300 }
1301 
1302 #ifdef ASSERT
1303 uint Compile::count_live_nodes_by_graph_walk() {
1304   Unique_Node_List useful(comp_arena());
1305   // Get useful node list by walking the graph.
1306   identify_useful_nodes(useful);
1307   return useful.size();
1308 }
1309 
1310 void Compile::print_missing_nodes() {
1311 
1312   // Return if CompileLog is NULL and PrintIdealNodeCount is false.
1313   if ((_log == NULL) && (! PrintIdealNodeCount)) {
1314     return;
1315   }
1316 
1317   // This is an expensive function. It is executed only when the user
1318   // specifies VerifyIdealNodeCount option or otherwise knows the
1319   // additional work that needs to be done to identify reachable nodes
1320   // by walking the flow graph and find the missing ones using
1321   // _dead_node_list.
1322 
1323   Unique_Node_List useful(comp_arena());
1324   // Get useful node list by walking the graph.
1325   identify_useful_nodes(useful);
1326 
1327   uint l_nodes = C->live_nodes();
1328   uint l_nodes_by_walk = useful.size();
1329 
1330   if (l_nodes != l_nodes_by_walk) {
1331     if (_log != NULL) {
1332       _log->begin_head("mismatched_nodes count='%d'", abs((int) (l_nodes - l_nodes_by_walk)));
1333       _log->stamp();
1334       _log->end_head();
1335     }
1336     VectorSet& useful_member_set = useful.member_set();
1337     int last_idx = l_nodes_by_walk;
1338     for (int i = 0; i < last_idx; i++) {
1339       if (useful_member_set.test(i)) {
1340         if (_dead_node_list.test(i)) {
1341           if (_log != NULL) {
1342             _log->elem("mismatched_node_info node_idx='%d' type='both live and dead'", i);
1343           }
1344           if (PrintIdealNodeCount) {
1345             // Print the log message to tty
1346               tty->print_cr("mismatched_node idx='%d' both live and dead'", i);
1347               useful.at(i)->dump();
1348           }
1349         }
1350       }
1351       else if (! _dead_node_list.test(i)) {
1352         if (_log != NULL) {
1353           _log->elem("mismatched_node_info node_idx='%d' type='neither live nor dead'", i);
1354         }
1355         if (PrintIdealNodeCount) {
1356           // Print the log message to tty
1357           tty->print_cr("mismatched_node idx='%d' type='neither live nor dead'", i);
1358         }
1359       }
1360     }
1361     if (_log != NULL) {
1362       _log->tail("mismatched_nodes");
1363     }
1364   }
1365 }
1366 void Compile::record_modified_node(Node* n) {
1367   if (_modified_nodes != NULL && !_inlining_incrementally &&
1368       n->outcnt() != 0 && !n->is_Con()) {
1369     _modified_nodes->push(n);
1370   }
1371 }
1372 
1373 void Compile::remove_modified_node(Node* n) {
1374   if (_modified_nodes != NULL) {
1375     _modified_nodes->remove(n);
1376   }
1377 }
1378 #endif
1379 
1380 #ifndef PRODUCT
1381 void Compile::verify_top(Node* tn) const {
1382   if (tn != NULL) {
1383     assert(tn->is_Con(), "top node must be a constant");
1384     assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
1385     assert(tn->in(0) != NULL, "must have live top node");
1386   }
1387 }
1388 #endif
1389 
1390 
1391 ///-------------------Managing Per-Node Debug & Profile Info-------------------
1392 
1393 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
1394   guarantee(arr != NULL, "");
1395   int num_blocks = arr->length();
1396   if (grow_by < num_blocks)  grow_by = num_blocks;
1397   int num_notes = grow_by * _node_notes_block_size;
1398   Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
1399   Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
1400   while (num_notes > 0) {
1401     arr->append(notes);
1402     notes     += _node_notes_block_size;
1403     num_notes -= _node_notes_block_size;
1404   }
1405   assert(num_notes == 0, "exact multiple, please");
1406 }
1407 
1408 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
1409   if (source == NULL || dest == NULL)  return false;
1410 
1411   if (dest->is_Con())
1412     return false;               // Do not push debug info onto constants.
1413 
1414 #ifdef ASSERT
1415   // Leave a bread crumb trail pointing to the original node:
1416   if (dest != NULL && dest != source && dest->debug_orig() == NULL) {
1417     dest->set_debug_orig(source);
1418   }
1419 #endif
1420 
1421   if (node_note_array() == NULL)
1422     return false;               // Not collecting any notes now.
1423 
1424   // This is a copy onto a pre-existing node, which may already have notes.
1425   // If both nodes have notes, do not overwrite any pre-existing notes.
1426   Node_Notes* source_notes = node_notes_at(source->_idx);
1427   if (source_notes == NULL || source_notes->is_clear())  return false;
1428   Node_Notes* dest_notes   = node_notes_at(dest->_idx);
1429   if (dest_notes == NULL || dest_notes->is_clear()) {
1430     return set_node_notes_at(dest->_idx, source_notes);
1431   }
1432 
1433   Node_Notes merged_notes = (*source_notes);
1434   // The order of operations here ensures that dest notes will win...
1435   merged_notes.update_from(dest_notes);
1436   return set_node_notes_at(dest->_idx, &merged_notes);
1437 }
1438 
1439 
1440 //--------------------------allow_range_check_smearing-------------------------
1441 // Gating condition for coalescing similar range checks.
1442 // Sometimes we try 'speculatively' replacing a series of a range checks by a
1443 // single covering check that is at least as strong as any of them.
1444 // If the optimization succeeds, the simplified (strengthened) range check
1445 // will always succeed.  If it fails, we will deopt, and then give up
1446 // on the optimization.
1447 bool Compile::allow_range_check_smearing() const {
1448   // If this method has already thrown a range-check,
1449   // assume it was because we already tried range smearing
1450   // and it failed.
1451   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
1452   return !already_trapped;
1453 }
1454 
1455 
1456 //------------------------------flatten_alias_type-----------------------------
1457 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
1458   int offset = tj->offset();
1459   TypePtr::PTR ptr = tj->ptr();
1460 
1461   // Known instance (scalarizable allocation) alias only with itself.
1462   bool is_known_inst = tj->isa_oopptr() != NULL &&
1463                        tj->is_oopptr()->is_known_instance();
1464 
1465   // Process weird unsafe references.
1466   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
1467     bool default_value_load = EnableValhalla && tj->is_instptr()->klass() == ciEnv::current()->Class_klass();
1468     assert(InlineUnsafeOps || default_value_load, "indeterminate pointers come only from unsafe ops");
1469     assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
1470     tj = TypeOopPtr::BOTTOM;
1471     ptr = tj->ptr();
1472     offset = tj->offset();
1473   }
1474 
1475   // Array pointers need some flattening
1476   const TypeAryPtr *ta = tj->isa_aryptr();
1477   if (ta && ta->is_stable()) {
1478     // Erase stability property for alias analysis.
1479     tj = ta = ta->cast_to_stable(false);
1480   }
1481   if( ta && is_known_inst ) {
1482     if ( offset != Type::OffsetBot &&
1483          offset > arrayOopDesc::length_offset_in_bytes() ) {
1484       offset = Type::OffsetBot; // Flatten constant access into array body only
1485       tj = ta = TypeAryPtr::make(ptr, ta->ary(), ta->klass(), true, Type::Offset(offset), ta->field_offset(), ta->instance_id());
1486     }
1487   } else if( ta && _AliasLevel >= 2 ) {
1488     // For arrays indexed by constant indices, we flatten the alias
1489     // space to include all of the array body.  Only the header, klass
1490     // and array length can be accessed un-aliased.
1491     // For flattened value type array, each field has its own slice so
1492     // we must include the field offset.
1493     if( offset != Type::OffsetBot ) {
1494       if( ta->const_oop() ) { // MethodData* or Method*
1495         offset = Type::OffsetBot;   // Flatten constant access into array body
1496         tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),ta->ary(),ta->klass(),false,Type::Offset(offset), ta->field_offset());
1497       } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
1498         // range is OK as-is.
1499         tj = ta = TypeAryPtr::RANGE;
1500       } else if( offset == oopDesc::klass_offset_in_bytes() ) {
1501         tj = TypeInstPtr::KLASS; // all klass loads look alike
1502         ta = TypeAryPtr::RANGE; // generic ignored junk
1503         ptr = TypePtr::BotPTR;
1504       } else if( offset == oopDesc::mark_offset_in_bytes() ) {
1505         tj = TypeInstPtr::MARK;
1506         ta = TypeAryPtr::RANGE; // generic ignored junk
1507         ptr = TypePtr::BotPTR;
1508       } else if (BarrierSet::barrier_set()->barrier_set_c2()->flatten_gc_alias_type(tj)) {
1509         ta = tj->isa_aryptr();
1510       } else {                  // Random constant offset into array body
1511         offset = Type::OffsetBot;   // Flatten constant access into array body
1512         tj = ta = TypeAryPtr::make(ptr,ta->ary(),ta->klass(),false,Type::Offset(offset), ta->field_offset());
1513       }
1514     }
1515     // Arrays of fixed size alias with arrays of unknown size.
1516     if (ta->size() != TypeInt::POS) {
1517       const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
1518       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,ta->klass(),false,Type::Offset(offset), ta->field_offset());
1519     }
1520     // Arrays of known objects become arrays of unknown objects.
1521     if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
1522       const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
1523       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,Type::Offset(offset), ta->field_offset());
1524     }
1525     if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
1526       const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
1527       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,Type::Offset(offset), ta->field_offset());
1528     }
1529     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
1530     // cannot be distinguished by bytecode alone.
1531     if (ta->elem() == TypeInt::BOOL) {
1532       const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
1533       ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
1534       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,Type::Offset(offset), ta->field_offset());
1535     }
1536     // During the 2nd round of IterGVN, NotNull castings are removed.
1537     // Make sure the Bottom and NotNull variants alias the same.
1538     // Also, make sure exact and non-exact variants alias the same.
1539     if (ptr == TypePtr::NotNull || ta->klass_is_exact() || ta->speculative() != NULL) {
1540       tj = ta = TypeAryPtr::make(TypePtr::BotPTR,ta->ary(),ta->klass(),false,Type::Offset(offset), ta->field_offset());
1541     }
1542   }
1543 
1544   // Oop pointers need some flattening
1545   const TypeInstPtr *to = tj->isa_instptr();
1546   if( to && _AliasLevel >= 2 && to != TypeOopPtr::BOTTOM ) {
1547     ciInstanceKlass *k = to->klass()->as_instance_klass();
1548     if( ptr == TypePtr::Constant ) {
1549       if (to->klass() != ciEnv::current()->Class_klass() ||
1550           offset < k->size_helper() * wordSize) {
1551         // No constant oop pointers (such as Strings); they alias with
1552         // unknown strings.
1553         assert(!is_known_inst, "not scalarizable allocation");
1554         tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,Type::Offset(offset));
1555       }
1556     } else if( is_known_inst ) {
1557       tj = to; // Keep NotNull and klass_is_exact for instance type
1558     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
1559       // During the 2nd round of IterGVN, NotNull castings are removed.
1560       // Make sure the Bottom and NotNull variants alias the same.
1561       // Also, make sure exact and non-exact variants alias the same.
1562       tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,Type::Offset(offset));
1563     }
1564     if (to->speculative() != NULL) {
1565       tj = to = TypeInstPtr::make(to->ptr(),to->klass(),to->klass_is_exact(),to->const_oop(),Type::Offset(to->offset()), to->instance_id());
1566     }
1567     // Canonicalize the holder of this field
1568     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
1569       // First handle header references such as a LoadKlassNode, even if the
1570       // object's klass is unloaded at compile time (4965979).
1571       if (!is_known_inst) { // Do it only for non-instance types
1572         tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, NULL, Type::Offset(offset));
1573       }
1574     } else if (BarrierSet::barrier_set()->barrier_set_c2()->flatten_gc_alias_type(tj)) {
1575       to = tj->is_instptr();
1576     } else if (offset < 0 || offset >= k->size_helper() * wordSize) {
1577       // Static fields are in the space above the normal instance
1578       // fields in the java.lang.Class instance.
1579       if (to->klass() != ciEnv::current()->Class_klass()) {
1580         to = NULL;
1581         tj = TypeOopPtr::BOTTOM;
1582         offset = tj->offset();
1583       }
1584     } else {
1585       ciInstanceKlass *canonical_holder = k->get_canonical_holder(offset);
1586       if (!k->equals(canonical_holder) || tj->offset() != offset) {
1587         if( is_known_inst ) {
1588           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, true, NULL, Type::Offset(offset), to->instance_id());
1589         } else {
1590           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, false, NULL, Type::Offset(offset));
1591         }
1592       }
1593     }
1594   }
1595 
1596   // Klass pointers to object array klasses need some flattening
1597   const TypeKlassPtr *tk = tj->isa_klassptr();
1598   if( tk ) {
1599     // If we are referencing a field within a Klass, we need
1600     // to assume the worst case of an Object.  Both exact and
1601     // inexact types must flatten to the same alias class so
1602     // use NotNull as the PTR.
1603     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
1604 
1605       tj = tk = TypeKlassPtr::make(TypePtr::NotNull,
1606                                    TypeKlassPtr::OBJECT->klass(),
1607                                    Type::Offset(offset));
1608     }
1609 
1610     ciKlass* klass = tk->klass();
1611     if (klass != NULL && klass->is_obj_array_klass()) {
1612       ciKlass* k = TypeAryPtr::OOPS->klass();
1613       if( !k || !k->is_loaded() )                  // Only fails for some -Xcomp runs
1614         k = TypeInstPtr::BOTTOM->klass();
1615       tj = tk = TypeKlassPtr::make(TypePtr::NotNull, k, Type::Offset(offset));
1616     }
1617 
1618     // Check for precise loads from the primary supertype array and force them
1619     // to the supertype cache alias index.  Check for generic array loads from
1620     // the primary supertype array and also force them to the supertype cache
1621     // alias index.  Since the same load can reach both, we need to merge
1622     // these 2 disparate memories into the same alias class.  Since the
1623     // primary supertype array is read-only, there's no chance of confusion
1624     // where we bypass an array load and an array store.
1625     int primary_supers_offset = in_bytes(Klass::primary_supers_offset());
1626     if (offset == Type::OffsetBot ||
1627         (offset >= primary_supers_offset &&
1628          offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
1629         offset == (int)in_bytes(Klass::secondary_super_cache_offset())) {
1630       offset = in_bytes(Klass::secondary_super_cache_offset());
1631       tj = tk = TypeKlassPtr::make(TypePtr::NotNull, tk->klass(), Type::Offset(offset));
1632     }
1633   }
1634 
1635   // Flatten all Raw pointers together.
1636   if (tj->base() == Type::RawPtr)
1637     tj = TypeRawPtr::BOTTOM;
1638 
1639   if (tj->base() == Type::AnyPtr)
1640     tj = TypePtr::BOTTOM;      // An error, which the caller must check for.
1641 
1642   // Flatten all to bottom for now
1643   switch( _AliasLevel ) {
1644   case 0:
1645     tj = TypePtr::BOTTOM;
1646     break;
1647   case 1:                       // Flatten to: oop, static, field or array
1648     switch (tj->base()) {
1649     //case Type::AryPtr: tj = TypeAryPtr::RANGE;    break;
1650     case Type::RawPtr:   tj = TypeRawPtr::BOTTOM;   break;
1651     case Type::AryPtr:   // do not distinguish arrays at all
1652     case Type::InstPtr:  tj = TypeInstPtr::BOTTOM;  break;
1653     case Type::KlassPtr: tj = TypeKlassPtr::OBJECT; break;
1654     case Type::AnyPtr:   tj = TypePtr::BOTTOM;      break;  // caller checks it
1655     default: ShouldNotReachHere();
1656     }
1657     break;
1658   case 2:                       // No collapsing at level 2; keep all splits
1659   case 3:                       // No collapsing at level 3; keep all splits
1660     break;
1661   default:
1662     Unimplemented();
1663   }
1664 
1665   offset = tj->offset();
1666   assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
1667 
1668   assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
1669           (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
1670           (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
1671           (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
1672           (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1673           (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1674           (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1675           (BarrierSet::barrier_set()->barrier_set_c2()->verify_gc_alias_type(tj, offset)),
1676           "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
1677   assert( tj->ptr() != TypePtr::TopPTR &&
1678           tj->ptr() != TypePtr::AnyNull &&
1679           tj->ptr() != TypePtr::Null, "No imprecise addresses" );
1680 //    assert( tj->ptr() != TypePtr::Constant ||
1681 //            tj->base() == Type::RawPtr ||
1682 //            tj->base() == Type::KlassPtr, "No constant oop addresses" );
1683 
1684   return tj;
1685 }
1686 
1687 void Compile::AliasType::Init(int i, const TypePtr* at) {
1688   _index = i;
1689   _adr_type = at;
1690   _field = NULL;
1691   _element = NULL;
1692   _is_rewritable = true; // default
1693   const TypeOopPtr *atoop = (at != NULL) ? at->isa_oopptr() : NULL;
1694   if (atoop != NULL && atoop->is_known_instance()) {
1695     const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
1696     _general_index = Compile::current()->get_alias_index(gt);
1697   } else {
1698     _general_index = 0;
1699   }
1700 }
1701 
1702 BasicType Compile::AliasType::basic_type() const {
1703   if (element() != NULL) {
1704     const Type* element = adr_type()->is_aryptr()->elem();
1705     return element->isa_narrowoop() ? T_OBJECT : element->array_element_basic_type();
1706   } if (field() != NULL) {
1707     return field()->layout_type();
1708   } else {
1709     return T_ILLEGAL; // unknown
1710   }
1711 }
1712 
1713 //---------------------------------print_on------------------------------------
1714 #ifndef PRODUCT
1715 void Compile::AliasType::print_on(outputStream* st) {
1716   if (index() < 10)
1717         st->print("@ <%d> ", index());
1718   else  st->print("@ <%d>",  index());
1719   st->print(is_rewritable() ? "   " : " RO");
1720   int offset = adr_type()->offset();
1721   if (offset == Type::OffsetBot)
1722         st->print(" +any");
1723   else  st->print(" +%-3d", offset);
1724   st->print(" in ");
1725   adr_type()->dump_on(st);
1726   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
1727   if (field() != NULL && tjp) {
1728     if (tjp->klass()  != field()->holder() ||
1729         tjp->offset() != field()->offset_in_bytes()) {
1730       st->print(" != ");
1731       field()->print();
1732       st->print(" ***");
1733     }
1734   }
1735 }
1736 
1737 void print_alias_types() {
1738   Compile* C = Compile::current();
1739   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
1740   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
1741     C->alias_type(idx)->print_on(tty);
1742     tty->cr();
1743   }
1744 }
1745 #endif
1746 
1747 
1748 //----------------------------probe_alias_cache--------------------------------
1749 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
1750   intptr_t key = (intptr_t) adr_type;
1751   key ^= key >> logAliasCacheSize;
1752   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
1753 }
1754 
1755 
1756 //-----------------------------grow_alias_types--------------------------------
1757 void Compile::grow_alias_types() {
1758   const int old_ats  = _max_alias_types; // how many before?
1759   const int new_ats  = old_ats;          // how many more?
1760   const int grow_ats = old_ats+new_ats;  // how many now?
1761   _max_alias_types = grow_ats;
1762   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
1763   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
1764   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
1765   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
1766 }
1767 
1768 
1769 //--------------------------------find_alias_type------------------------------
1770 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field) {
1771   if (_AliasLevel == 0)
1772     return alias_type(AliasIdxBot);
1773 
1774   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1775   if (ace->_adr_type == adr_type) {
1776     return alias_type(ace->_index);
1777   }
1778 
1779   // Handle special cases.
1780   if (adr_type == NULL)             return alias_type(AliasIdxTop);
1781   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
1782 
1783   // Do it the slow way.
1784   const TypePtr* flat = flatten_alias_type(adr_type);
1785 
1786 #ifdef ASSERT
1787   {
1788     ResourceMark rm;
1789     assert(flat == flatten_alias_type(flat), "not idempotent: adr_type = %s; flat = %s => %s",
1790            Type::str(adr_type), Type::str(flat), Type::str(flatten_alias_type(flat)));
1791     assert(flat != TypePtr::BOTTOM, "cannot alias-analyze an untyped ptr: adr_type = %s",
1792            Type::str(adr_type));
1793     if (flat->isa_oopptr() && !flat->isa_klassptr()) {
1794       const TypeOopPtr* foop = flat->is_oopptr();
1795       // Scalarizable allocations have exact klass always.
1796       bool exact = !foop->klass_is_exact() || foop->is_known_instance();
1797       const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
1798       assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type: foop = %s; xoop = %s",
1799              Type::str(foop), Type::str(xoop));
1800     }
1801   }
1802 #endif
1803 
1804   int idx = AliasIdxTop;
1805   for (int i = 0; i < num_alias_types(); i++) {
1806     if (alias_type(i)->adr_type() == flat) {
1807       idx = i;
1808       break;
1809     }
1810   }
1811 
1812   if (idx == AliasIdxTop) {
1813     if (no_create)  return NULL;
1814     // Grow the array if necessary.
1815     if (_num_alias_types == _max_alias_types)  grow_alias_types();
1816     // Add a new alias type.
1817     idx = _num_alias_types++;
1818     _alias_types[idx]->Init(idx, flat);
1819     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
1820     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
1821     if (flat->isa_instptr()) {
1822       if (flat->offset() == java_lang_Class::klass_offset_in_bytes()
1823           && flat->is_instptr()->klass() == env()->Class_klass())
1824         alias_type(idx)->set_rewritable(false);
1825     }
1826     ciField* field = NULL;
1827     if (flat->isa_aryptr()) {
1828 #ifdef ASSERT
1829       const int header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1830       // (T_BYTE has the weakest alignment and size restrictions...)
1831       assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
1832 #endif
1833       const Type* elemtype = flat->is_aryptr()->elem();
1834       if (flat->offset() == TypePtr::OffsetBot) {
1835         alias_type(idx)->set_element(elemtype);
1836       }
1837       int field_offset = flat->is_aryptr()->field_offset().get();
1838       if (elemtype->isa_valuetype() && field_offset != Type::OffsetBot) {
1839         ciValueKlass* vk = elemtype->is_valuetype()->value_klass();
1840         field_offset += vk->first_field_offset();
1841         field = vk->get_field_by_offset(field_offset, false);
1842       }
1843     }
1844     if (flat->isa_klassptr()) {
1845       if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
1846         alias_type(idx)->set_rewritable(false);
1847       if (flat->offset() == in_bytes(Klass::modifier_flags_offset()))
1848         alias_type(idx)->set_rewritable(false);
1849       if (flat->offset() == in_bytes(Klass::access_flags_offset()))
1850         alias_type(idx)->set_rewritable(false);
1851       if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
1852         alias_type(idx)->set_rewritable(false);
1853     }
1854     // %%% (We would like to finalize JavaThread::threadObj_offset(),
1855     // but the base pointer type is not distinctive enough to identify
1856     // references into JavaThread.)
1857 
1858     // Check for final fields.
1859     const TypeInstPtr* tinst = flat->isa_instptr();
1860     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
1861       if (tinst->const_oop() != NULL &&
1862           tinst->klass() == ciEnv::current()->Class_klass() &&
1863           tinst->offset() >= (tinst->klass()->as_instance_klass()->size_helper() * wordSize)) {
1864         // static field
1865         ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
1866         field = k->get_field_by_offset(tinst->offset(), true);
1867       } else if (tinst->klass()->is_valuetype()) {
1868         // Value type field
1869         ciValueKlass* vk = tinst->value_klass();
1870         field = vk->get_field_by_offset(tinst->offset(), false);
1871       } else {
1872         ciInstanceKlass* k = tinst->klass()->as_instance_klass();
1873         field = k->get_field_by_offset(tinst->offset(), false);
1874       }
1875     }
1876     assert(field == NULL ||
1877            original_field == NULL ||
1878            (field->holder() == original_field->holder() &&
1879             field->offset() == original_field->offset() &&
1880             field->is_static() == original_field->is_static()), "wrong field?");
1881     // Set field() and is_rewritable() attributes.
1882     if (field != NULL)  alias_type(idx)->set_field(field);
1883   }
1884 
1885   // Fill the cache for next time.
1886   ace->_adr_type = adr_type;
1887   ace->_index    = idx;
1888   assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
1889 
1890   // Might as well try to fill the cache for the flattened version, too.
1891   AliasCacheEntry* face = probe_alias_cache(flat);
1892   if (face->_adr_type == NULL) {
1893     face->_adr_type = flat;
1894     face->_index    = idx;
1895     assert(alias_type(flat) == alias_type(idx), "flat type must work too");
1896   }
1897 
1898   return alias_type(idx);
1899 }
1900 
1901 
1902 Compile::AliasType* Compile::alias_type(ciField* field) {
1903   const TypeOopPtr* t;
1904   if (field->is_static())
1905     t = TypeInstPtr::make(field->holder()->java_mirror());
1906   else
1907     t = TypeOopPtr::make_from_klass_raw(field->holder());
1908   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);
1909   assert((field->is_final() || field->is_stable()) == !atp->is_rewritable(), "must get the rewritable bits correct");
1910   return atp;
1911 }
1912 
1913 
1914 //------------------------------have_alias_type--------------------------------
1915 bool Compile::have_alias_type(const TypePtr* adr_type) {
1916   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1917   if (ace->_adr_type == adr_type) {
1918     return true;
1919   }
1920 
1921   // Handle special cases.
1922   if (adr_type == NULL)             return true;
1923   if (adr_type == TypePtr::BOTTOM)  return true;
1924 
1925   return find_alias_type(adr_type, true, NULL) != NULL;
1926 }
1927 
1928 //-----------------------------must_alias--------------------------------------
1929 // True if all values of the given address type are in the given alias category.
1930 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
1931   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1932   if (adr_type == NULL)                 return true;  // NULL serves as TypePtr::TOP
1933   if (alias_idx == AliasIdxTop)         return false; // the empty category
1934   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
1935 
1936   // the only remaining possible overlap is identity
1937   int adr_idx = get_alias_index(adr_type);
1938   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1939   assert(adr_idx == alias_idx ||
1940          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
1941           && adr_type                       != TypeOopPtr::BOTTOM),
1942          "should not be testing for overlap with an unsafe pointer");
1943   return adr_idx == alias_idx;
1944 }
1945 
1946 //------------------------------can_alias--------------------------------------
1947 // True if any values of the given address type are in the given alias category.
1948 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
1949   if (alias_idx == AliasIdxTop)         return false; // the empty category
1950   if (adr_type == NULL)                 return false; // NULL serves as TypePtr::TOP
1951   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1952   if (adr_type->base() == Type::AnyPtr) return true;  // TypePtr::BOTTOM or its twins
1953 
1954   // the only remaining possible overlap is identity
1955   int adr_idx = get_alias_index(adr_type);
1956   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1957   return adr_idx == alias_idx;
1958 }
1959 
1960 
1961 
1962 //---------------------------pop_warm_call-------------------------------------
1963 WarmCallInfo* Compile::pop_warm_call() {
1964   WarmCallInfo* wci = _warm_calls;
1965   if (wci != NULL)  _warm_calls = wci->remove_from(wci);
1966   return wci;
1967 }
1968 
1969 //----------------------------Inline_Warm--------------------------------------
1970 int Compile::Inline_Warm() {
1971   // If there is room, try to inline some more warm call sites.
1972   // %%% Do a graph index compaction pass when we think we're out of space?
1973   if (!InlineWarmCalls)  return 0;
1974 
1975   int calls_made_hot = 0;
1976   int room_to_grow   = NodeCountInliningCutoff - unique();
1977   int amount_to_grow = MIN2(room_to_grow, (int)NodeCountInliningStep);
1978   int amount_grown   = 0;
1979   WarmCallInfo* call;
1980   while (amount_to_grow > 0 && (call = pop_warm_call()) != NULL) {
1981     int est_size = (int)call->size();
1982     if (est_size > (room_to_grow - amount_grown)) {
1983       // This one won't fit anyway.  Get rid of it.
1984       call->make_cold();
1985       continue;
1986     }
1987     call->make_hot();
1988     calls_made_hot++;
1989     amount_grown   += est_size;
1990     amount_to_grow -= est_size;
1991   }
1992 
1993   if (calls_made_hot > 0)  set_major_progress();
1994   return calls_made_hot;
1995 }
1996 
1997 
1998 //----------------------------Finish_Warm--------------------------------------
1999 void Compile::Finish_Warm() {
2000   if (!InlineWarmCalls)  return;
2001   if (failing())  return;
2002   if (warm_calls() == NULL)  return;
2003 
2004   // Clean up loose ends, if we are out of space for inlining.
2005   WarmCallInfo* call;
2006   while ((call = pop_warm_call()) != NULL) {
2007     call->make_cold();
2008   }
2009 }
2010 
2011 //---------------------cleanup_loop_predicates-----------------------
2012 // Remove the opaque nodes that protect the predicates so that all unused
2013 // checks and uncommon_traps will be eliminated from the ideal graph
2014 void Compile::cleanup_loop_predicates(PhaseIterGVN &igvn) {
2015   if (predicate_count()==0) return;
2016   for (int i = predicate_count(); i > 0; i--) {
2017     Node * n = predicate_opaque1_node(i-1);
2018     assert(n->Opcode() == Op_Opaque1, "must be");
2019     igvn.replace_node(n, n->in(1));
2020   }
2021   assert(predicate_count()==0, "should be clean!");
2022 }
2023 
2024 void Compile::add_range_check_cast(Node* n) {
2025   assert(n->isa_CastII()->has_range_check(), "CastII should have range check dependency");
2026   assert(!_range_check_casts->contains(n), "duplicate entry in range check casts");
2027   _range_check_casts->append(n);
2028 }
2029 
2030 // Remove all range check dependent CastIINodes.
2031 void Compile::remove_range_check_casts(PhaseIterGVN &igvn) {
2032   for (int i = range_check_cast_count(); i > 0; i--) {
2033     Node* cast = range_check_cast_node(i-1);
2034     assert(cast->isa_CastII()->has_range_check(), "CastII should have range check dependency");
2035     igvn.replace_node(cast, cast->in(1));
2036   }
2037   assert(range_check_cast_count() == 0, "should be empty");
2038 }
2039 
2040 void Compile::add_opaque4_node(Node* n) {
2041   assert(n->Opcode() == Op_Opaque4, "Opaque4 only");
2042   assert(!_opaque4_nodes->contains(n), "duplicate entry in Opaque4 list");
2043   _opaque4_nodes->append(n);
2044 }
2045 
2046 // Remove all Opaque4 nodes.
2047 void Compile::remove_opaque4_nodes(PhaseIterGVN &igvn) {
2048   for (int i = opaque4_count(); i > 0; i--) {
2049     Node* opaq = opaque4_node(i-1);
2050     assert(opaq->Opcode() == Op_Opaque4, "Opaque4 only");
2051     igvn.replace_node(opaq, opaq->in(2));
2052   }
2053   assert(opaque4_count() == 0, "should be empty");
2054 }
2055 
2056 void Compile::add_value_type(Node* n) {
2057   assert(n->is_ValueTypeBase(), "unexpected node");
2058   if (_value_type_nodes != NULL) {
2059     _value_type_nodes->push(n);
2060   }
2061 }
2062 
2063 void Compile::remove_value_type(Node* n) {
2064   assert(n->is_ValueTypeBase(), "unexpected node");
2065   if (_value_type_nodes != NULL) {
2066     _value_type_nodes->remove(n);
2067   }
2068 }
2069 
2070 void Compile::process_value_types(PhaseIterGVN &igvn) {
2071   // Make value types scalar in safepoints
2072   while (_value_type_nodes->size() != 0) {
2073     ValueTypeBaseNode* vt = _value_type_nodes->pop()->as_ValueTypeBase();
2074     vt->make_scalar_in_safepoints(igvn.C->root(), &igvn);
2075     if (vt->is_ValueTypePtr()) {
2076       igvn.replace_node(vt, vt->get_oop());
2077     }
2078   }
2079   _value_type_nodes = NULL;
2080   igvn.optimize();
2081 }
2082 
2083 // StringOpts and late inlining of string methods
2084 void Compile::inline_string_calls(bool parse_time) {
2085   {
2086     // remove useless nodes to make the usage analysis simpler
2087     ResourceMark rm;
2088     PhaseRemoveUseless pru(initial_gvn(), for_igvn());
2089   }
2090 
2091   {
2092     ResourceMark rm;
2093     print_method(PHASE_BEFORE_STRINGOPTS, 3);
2094     PhaseStringOpts pso(initial_gvn(), for_igvn());
2095     print_method(PHASE_AFTER_STRINGOPTS, 3);
2096   }
2097 
2098   // now inline anything that we skipped the first time around
2099   if (!parse_time) {
2100     _late_inlines_pos = _late_inlines.length();
2101   }
2102 
2103   while (_string_late_inlines.length() > 0) {
2104     CallGenerator* cg = _string_late_inlines.pop();
2105     cg->do_late_inline();
2106     if (failing())  return;
2107   }
2108   _string_late_inlines.trunc_to(0);
2109 }
2110 
2111 // Late inlining of boxing methods
2112 void Compile::inline_boxing_calls(PhaseIterGVN& igvn) {
2113   if (_boxing_late_inlines.length() > 0) {
2114     assert(has_boxed_value(), "inconsistent");
2115 
2116     PhaseGVN* gvn = initial_gvn();
2117     set_inlining_incrementally(true);
2118 
2119     assert( igvn._worklist.size() == 0, "should be done with igvn" );
2120     for_igvn()->clear();
2121     gvn->replace_with(&igvn);
2122 
2123     _late_inlines_pos = _late_inlines.length();
2124 
2125     while (_boxing_late_inlines.length() > 0) {
2126       CallGenerator* cg = _boxing_late_inlines.pop();
2127       cg->do_late_inline();
2128       if (failing())  return;
2129     }
2130     _boxing_late_inlines.trunc_to(0);
2131 
2132     {
2133       ResourceMark rm;
2134       PhaseRemoveUseless pru(gvn, for_igvn());
2135     }
2136 
2137     igvn = PhaseIterGVN(gvn);
2138     igvn.optimize();
2139 
2140     set_inlining_progress(false);
2141     set_inlining_incrementally(false);
2142   }
2143 }
2144 
2145 void Compile::inline_incrementally_one(PhaseIterGVN& igvn) {
2146   assert(IncrementalInline, "incremental inlining should be on");
2147   PhaseGVN* gvn = initial_gvn();
2148 
2149   set_inlining_progress(false);
2150   for_igvn()->clear();
2151   gvn->replace_with(&igvn);
2152 
2153   {
2154     TracePhase tp("incrementalInline_inline", &timers[_t_incrInline_inline]);
2155     int i = 0;
2156     for (; i <_late_inlines.length() && !inlining_progress(); i++) {
2157       CallGenerator* cg = _late_inlines.at(i);
2158       _late_inlines_pos = i+1;
2159       cg->do_late_inline();
2160       if (failing())  return;
2161     }
2162     int j = 0;
2163     for (; i < _late_inlines.length(); i++, j++) {
2164       _late_inlines.at_put(j, _late_inlines.at(i));
2165     }
2166     _late_inlines.trunc_to(j);
2167   }
2168 
2169   {
2170     TracePhase tp("incrementalInline_pru", &timers[_t_incrInline_pru]);
2171     ResourceMark rm;
2172     PhaseRemoveUseless pru(gvn, for_igvn());
2173   }
2174 
2175   {
2176     TracePhase tp("incrementalInline_igvn", &timers[_t_incrInline_igvn]);
2177     igvn = PhaseIterGVN(gvn);
2178   }
2179 }
2180 
2181 // Perform incremental inlining until bound on number of live nodes is reached
2182 void Compile::inline_incrementally(PhaseIterGVN& igvn) {
2183   TracePhase tp("incrementalInline", &timers[_t_incrInline]);
2184 
2185   PhaseGVN* gvn = initial_gvn();
2186 
2187   set_inlining_incrementally(true);
2188   set_inlining_progress(true);
2189   uint low_live_nodes = 0;
2190 
2191   while(inlining_progress() && _late_inlines.length() > 0) {
2192 
2193     if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2194       if (low_live_nodes < (uint)LiveNodeCountInliningCutoff * 8 / 10) {
2195         TracePhase tp("incrementalInline_ideal", &timers[_t_incrInline_ideal]);
2196         // PhaseIdealLoop is expensive so we only try it once we are
2197         // out of live nodes and we only try it again if the previous
2198         // helped got the number of nodes down significantly
2199         PhaseIdealLoop ideal_loop(igvn, LoopOptsNone);
2200         if (failing())  return;
2201         low_live_nodes = live_nodes();
2202         _major_progress = true;
2203       }
2204 
2205       if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2206         break;
2207       }
2208     }
2209 
2210     inline_incrementally_one(igvn);
2211 
2212     if (failing())  return;
2213 
2214     {
2215       TracePhase tp("incrementalInline_igvn", &timers[_t_incrInline_igvn]);
2216       igvn.optimize();
2217     }
2218 
2219     if (failing())  return;
2220   }
2221 
2222   assert( igvn._worklist.size() == 0, "should be done with igvn" );
2223 
2224   if (_string_late_inlines.length() > 0) {
2225     assert(has_stringbuilder(), "inconsistent");
2226     for_igvn()->clear();
2227     initial_gvn()->replace_with(&igvn);
2228 
2229     inline_string_calls(false);
2230 
2231     if (failing())  return;
2232 
2233     {
2234       TracePhase tp("incrementalInline_pru", &timers[_t_incrInline_pru]);
2235       ResourceMark rm;
2236       PhaseRemoveUseless pru(initial_gvn(), for_igvn());
2237     }
2238 
2239     {
2240       TracePhase tp("incrementalInline_igvn", &timers[_t_incrInline_igvn]);
2241       igvn = PhaseIterGVN(gvn);
2242       igvn.optimize();
2243     }
2244   }
2245 
2246   set_inlining_incrementally(false);
2247 }
2248 
2249 
2250 bool Compile::optimize_loops(int& loop_opts_cnt, PhaseIterGVN& igvn, LoopOptsMode mode) {
2251   if(loop_opts_cnt > 0) {
2252     debug_only( int cnt = 0; );
2253     while(major_progress() && (loop_opts_cnt > 0)) {
2254       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2255       assert( cnt++ < 40, "infinite cycle in loop optimization" );
2256       PhaseIdealLoop ideal_loop(igvn, mode);
2257       loop_opts_cnt--;
2258       if (failing())  return false;
2259       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
2260     }
2261   }
2262   return true;
2263 }
2264 
2265 //------------------------------Optimize---------------------------------------
2266 // Given a graph, optimize it.
2267 void Compile::Optimize() {
2268   TracePhase tp("optimizer", &timers[_t_optimizer]);
2269 
2270 #ifndef PRODUCT
2271   if (_directive->BreakAtCompileOption) {
2272     BREAKPOINT;
2273   }
2274 
2275 #endif
2276 
2277 #ifdef ASSERT
2278   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
2279   bs->verify_gc_barriers(this, BarrierSetC2::BeforeOptimize);
2280 #endif
2281 
2282   ResourceMark rm;
2283   int          loop_opts_cnt;
2284 
2285   print_inlining_reinit();
2286 
2287   NOT_PRODUCT( verify_graph_edges(); )
2288 
2289   print_method(PHASE_AFTER_PARSING);
2290 
2291  {
2292   // Iterative Global Value Numbering, including ideal transforms
2293   // Initialize IterGVN with types and values from parse-time GVN
2294   PhaseIterGVN igvn(initial_gvn());
2295 #ifdef ASSERT
2296   _modified_nodes = new (comp_arena()) Unique_Node_List(comp_arena());
2297 #endif
2298   {
2299     TracePhase tp("iterGVN", &timers[_t_iterGVN]);
2300     igvn.optimize();
2301   }
2302 
2303   if (failing())  return;
2304 
2305   print_method(PHASE_ITER_GVN1, 2);
2306 
2307   inline_incrementally(igvn);
2308 
2309   print_method(PHASE_INCREMENTAL_INLINE, 2);
2310 
2311   if (failing())  return;
2312 
2313   if (eliminate_boxing()) {
2314     // Inline valueOf() methods now.
2315     inline_boxing_calls(igvn);
2316 
2317     if (AlwaysIncrementalInline) {
2318       inline_incrementally(igvn);
2319     }
2320 
2321     print_method(PHASE_INCREMENTAL_BOXING_INLINE, 2);
2322 
2323     if (failing())  return;
2324   }
2325 
2326   // Remove the speculative part of types and clean up the graph from
2327   // the extra CastPP nodes whose only purpose is to carry them. Do
2328   // that early so that optimizations are not disrupted by the extra
2329   // CastPP nodes.
2330   remove_speculative_types(igvn);
2331 
2332   // No more new expensive nodes will be added to the list from here
2333   // so keep only the actual candidates for optimizations.
2334   cleanup_expensive_nodes(igvn);
2335 
2336   if (!failing() && RenumberLiveNodes && live_nodes() + NodeLimitFudgeFactor < unique()) {
2337     Compile::TracePhase tp("", &timers[_t_renumberLive]);
2338     initial_gvn()->replace_with(&igvn);
2339     for_igvn()->clear();
2340     Unique_Node_List new_worklist(C->comp_arena());
2341     {
2342       ResourceMark rm;
2343       PhaseRenumberLive prl = PhaseRenumberLive(initial_gvn(), for_igvn(), &new_worklist);
2344     }
2345     set_for_igvn(&new_worklist);
2346     igvn = PhaseIterGVN(initial_gvn());
2347     igvn.optimize();
2348   }
2349 
2350   if (_value_type_nodes->size() > 0) {
2351     // Do this once all inlining is over to avoid getting inconsistent debug info
2352     process_value_types(igvn);
2353   }
2354 
2355   // Perform escape analysis
2356   if (_do_escape_analysis && ConnectionGraph::has_candidates(this)) {
2357     if (has_loops()) {
2358       // Cleanup graph (remove dead nodes).
2359       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2360       PhaseIdealLoop ideal_loop(igvn, LoopOptsNone);
2361       if (major_progress()) print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
2362       if (failing())  return;
2363     }
2364     ConnectionGraph::do_analysis(this, &igvn);
2365 
2366     if (failing())  return;
2367 
2368     // Optimize out fields loads from scalar replaceable allocations.
2369     igvn.optimize();
2370     print_method(PHASE_ITER_GVN_AFTER_EA, 2);
2371 
2372     if (failing())  return;
2373 
2374     if (congraph() != NULL && macro_count() > 0) {
2375       TracePhase tp("macroEliminate", &timers[_t_macroEliminate]);
2376       PhaseMacroExpand mexp(igvn);
2377       mexp.eliminate_macro_nodes();
2378       igvn.set_delay_transform(false);
2379 
2380       igvn.optimize();
2381       print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
2382 
2383       if (failing())  return;
2384     }
2385   }
2386 
2387   // Loop transforms on the ideal graph.  Range Check Elimination,
2388   // peeling, unrolling, etc.
2389 
2390   // Set loop opts counter
2391   loop_opts_cnt = num_loop_opts();
2392   if((loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
2393     {
2394       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2395       PhaseIdealLoop ideal_loop(igvn, LoopOptsDefault);
2396       loop_opts_cnt--;
2397       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP1, 2);
2398       if (failing())  return;
2399     }
2400     // Loop opts pass if partial peeling occurred in previous pass
2401     if(PartialPeelLoop && major_progress() && (loop_opts_cnt > 0)) {
2402       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2403       PhaseIdealLoop ideal_loop(igvn, LoopOptsSkipSplitIf);
2404       loop_opts_cnt--;
2405       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP2, 2);
2406       if (failing())  return;
2407     }
2408     // Loop opts pass for loop-unrolling before CCP
2409     if(major_progress() && (loop_opts_cnt > 0)) {
2410       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2411       PhaseIdealLoop ideal_loop(igvn, LoopOptsSkipSplitIf);
2412       loop_opts_cnt--;
2413       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP3, 2);
2414     }
2415     if (!failing()) {
2416       // Verify that last round of loop opts produced a valid graph
2417       TracePhase tp("idealLoopVerify", &timers[_t_idealLoopVerify]);
2418       PhaseIdealLoop::verify(igvn);
2419     }
2420   }
2421   if (failing())  return;
2422 
2423   // Conditional Constant Propagation;
2424   PhaseCCP ccp( &igvn );
2425   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
2426   {
2427     TracePhase tp("ccp", &timers[_t_ccp]);
2428     ccp.do_transform();
2429   }
2430   print_method(PHASE_CPP1, 2);
2431 
2432   assert( true, "Break here to ccp.dump_old2new_map()");
2433 
2434   // Iterative Global Value Numbering, including ideal transforms
2435   {
2436     TracePhase tp("iterGVN2", &timers[_t_iterGVN2]);
2437     igvn = ccp;
2438     igvn.optimize();
2439   }
2440 
2441   print_method(PHASE_ITER_GVN2, 2);
2442 
2443   if (failing())  return;
2444 
2445   // Loop transforms on the ideal graph.  Range Check Elimination,
2446   // peeling, unrolling, etc.
2447   if (!optimize_loops(loop_opts_cnt, igvn, LoopOptsDefault)) {
2448     return;
2449   }
2450 
2451 #if INCLUDE_ZGC
2452   if (UseZGC) {
2453     ZBarrierSetC2::find_dominating_barriers(igvn);
2454   }
2455 #endif
2456 
2457   if (failing())  return;
2458 
2459   // Ensure that major progress is now clear
2460   C->clear_major_progress();
2461 
2462   {
2463     // Verify that all previous optimizations produced a valid graph
2464     // at least to this point, even if no loop optimizations were done.
2465     TracePhase tp("idealLoopVerify", &timers[_t_idealLoopVerify]);
2466     PhaseIdealLoop::verify(igvn);
2467   }
2468 
2469   if (range_check_cast_count() > 0) {
2470     // No more loop optimizations. Remove all range check dependent CastIINodes.
2471     C->remove_range_check_casts(igvn);
2472     igvn.optimize();
2473   }
2474 
2475 #ifdef ASSERT
2476   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
2477   bs->verify_gc_barriers(this, BarrierSetC2::BeforeExpand);
2478 #endif
2479 
2480   {
2481     TracePhase tp("macroExpand", &timers[_t_macroExpand]);
2482     PhaseMacroExpand  mex(igvn);
2483     print_method(PHASE_BEFORE_MACRO_EXPANSION, 2);
2484     if (mex.expand_macro_nodes()) {
2485       assert(failing(), "must bail out w/ explicit message");
2486       return;
2487     }
2488   }
2489 
2490   if (opaque4_count() > 0) {
2491     C->remove_opaque4_nodes(igvn);
2492     igvn.optimize();
2493   }
2494 
2495   DEBUG_ONLY( _modified_nodes = NULL; )
2496  } // (End scope of igvn; run destructor if necessary for asserts.)
2497 
2498  process_print_inlining();
2499  // A method with only infinite loops has no edges entering loops from root
2500  {
2501    TracePhase tp("graphReshape", &timers[_t_graphReshaping]);
2502    if (final_graph_reshaping()) {
2503      assert(failing(), "must bail out w/ explicit message");
2504      return;
2505    }
2506  }
2507 
2508  print_method(PHASE_OPTIMIZE_FINISHED, 2);
2509 }
2510 
2511 //------------------------------Code_Gen---------------------------------------
2512 // Given a graph, generate code for it
2513 void Compile::Code_Gen() {
2514   if (failing()) {
2515     return;
2516   }
2517 
2518   // Perform instruction selection.  You might think we could reclaim Matcher
2519   // memory PDQ, but actually the Matcher is used in generating spill code.
2520   // Internals of the Matcher (including some VectorSets) must remain live
2521   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
2522   // set a bit in reclaimed memory.
2523 
2524   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2525   // nodes.  Mapping is only valid at the root of each matched subtree.
2526   NOT_PRODUCT( verify_graph_edges(); )
2527 
2528   Matcher matcher;
2529   _matcher = &matcher;
2530   {
2531     TracePhase tp("matcher", &timers[_t_matcher]);
2532     matcher.match();
2533   }
2534   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2535   // nodes.  Mapping is only valid at the root of each matched subtree.
2536   NOT_PRODUCT( verify_graph_edges(); )
2537 
2538   // If you have too many nodes, or if matching has failed, bail out
2539   check_node_count(0, "out of nodes matching instructions");
2540   if (failing()) {
2541     return;
2542   }
2543 
2544   print_method(PHASE_MATCHING, 2);
2545 
2546   // Build a proper-looking CFG
2547   PhaseCFG cfg(node_arena(), root(), matcher);
2548   _cfg = &cfg;
2549   {
2550     TracePhase tp("scheduler", &timers[_t_scheduler]);
2551     bool success = cfg.do_global_code_motion();
2552     if (!success) {
2553       return;
2554     }
2555 
2556     print_method(PHASE_GLOBAL_CODE_MOTION, 2);
2557     NOT_PRODUCT( verify_graph_edges(); )
2558     debug_only( cfg.verify(); )
2559   }
2560 
2561   PhaseChaitin regalloc(unique(), cfg, matcher, false);
2562   _regalloc = &regalloc;
2563   {
2564     TracePhase tp("regalloc", &timers[_t_registerAllocation]);
2565     // Perform register allocation.  After Chaitin, use-def chains are
2566     // no longer accurate (at spill code) and so must be ignored.
2567     // Node->LRG->reg mappings are still accurate.
2568     _regalloc->Register_Allocate();
2569 
2570     // Bail out if the allocator builds too many nodes
2571     if (failing()) {
2572       return;
2573     }
2574   }
2575 
2576   // Prior to register allocation we kept empty basic blocks in case the
2577   // the allocator needed a place to spill.  After register allocation we
2578   // are not adding any new instructions.  If any basic block is empty, we
2579   // can now safely remove it.
2580   {
2581     TracePhase tp("blockOrdering", &timers[_t_blockOrdering]);
2582     cfg.remove_empty_blocks();
2583     if (do_freq_based_layout()) {
2584       PhaseBlockLayout layout(cfg);
2585     } else {
2586       cfg.set_loop_alignment();
2587     }
2588     cfg.fixup_flow();
2589   }
2590 
2591   // Apply peephole optimizations
2592   if( OptoPeephole ) {
2593     TracePhase tp("peephole", &timers[_t_peephole]);
2594     PhasePeephole peep( _regalloc, cfg);
2595     peep.do_transform();
2596   }
2597 
2598   // Do late expand if CPU requires this.
2599   if (Matcher::require_postalloc_expand) {
2600     TracePhase tp("postalloc_expand", &timers[_t_postalloc_expand]);
2601     cfg.postalloc_expand(_regalloc);
2602   }
2603 
2604   // Convert Nodes to instruction bits in a buffer
2605   {
2606     TraceTime tp("output", &timers[_t_output], CITime);
2607     Output();
2608   }
2609 
2610   print_method(PHASE_FINAL_CODE);
2611 
2612   // He's dead, Jim.
2613   _cfg     = (PhaseCFG*)((intptr_t)0xdeadbeef);
2614   _regalloc = (PhaseChaitin*)((intptr_t)0xdeadbeef);
2615 }
2616 
2617 
2618 //------------------------------dump_asm---------------------------------------
2619 // Dump formatted assembly
2620 #ifndef PRODUCT
2621 void Compile::dump_asm(int *pcs, uint pc_limit) {
2622   bool cut_short = false;
2623   tty->print_cr("#");
2624   tty->print("#  ");  _tf->dump();  tty->cr();
2625   tty->print_cr("#");
2626 
2627   // For all blocks
2628   int pc = 0x0;                 // Program counter
2629   char starts_bundle = ' ';
2630   _regalloc->dump_frame();
2631 
2632   Node *n = NULL;
2633   for (uint i = 0; i < _cfg->number_of_blocks(); i++) {
2634     if (VMThread::should_terminate()) {
2635       cut_short = true;
2636       break;
2637     }
2638     Block* block = _cfg->get_block(i);
2639     if (block->is_connector() && !Verbose) {
2640       continue;
2641     }
2642     n = block->head();
2643     if (pcs && n->_idx < pc_limit) {
2644       tty->print("%3.3x   ", pcs[n->_idx]);
2645     } else {
2646       tty->print("      ");
2647     }
2648     block->dump_head(_cfg);
2649     if (block->is_connector()) {
2650       tty->print_cr("        # Empty connector block");
2651     } else if (block->num_preds() == 2 && block->pred(1)->is_CatchProj() && block->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
2652       tty->print_cr("        # Block is sole successor of call");
2653     }
2654 
2655     // For all instructions
2656     Node *delay = NULL;
2657     for (uint j = 0; j < block->number_of_nodes(); j++) {
2658       if (VMThread::should_terminate()) {
2659         cut_short = true;
2660         break;
2661       }
2662       n = block->get_node(j);
2663       if (valid_bundle_info(n)) {
2664         Bundle* bundle = node_bundling(n);
2665         if (bundle->used_in_unconditional_delay()) {
2666           delay = n;
2667           continue;
2668         }
2669         if (bundle->starts_bundle()) {
2670           starts_bundle = '+';
2671         }
2672       }
2673 
2674       if (WizardMode) {
2675         n->dump();
2676       }
2677 
2678       if( !n->is_Region() &&    // Dont print in the Assembly
2679           !n->is_Phi() &&       // a few noisely useless nodes
2680           !n->is_Proj() &&
2681           !n->is_MachTemp() &&
2682           !n->is_SafePointScalarObject() &&
2683           !n->is_Catch() &&     // Would be nice to print exception table targets
2684           !n->is_MergeMem() &&  // Not very interesting
2685           !n->is_top() &&       // Debug info table constants
2686           !(n->is_Con() && !n->is_Mach())// Debug info table constants
2687           ) {
2688         if (pcs && n->_idx < pc_limit)
2689           tty->print("%3.3x", pcs[n->_idx]);
2690         else
2691           tty->print("   ");
2692         tty->print(" %c ", starts_bundle);
2693         starts_bundle = ' ';
2694         tty->print("\t");
2695         n->format(_regalloc, tty);
2696         tty->cr();
2697       }
2698 
2699       // If we have an instruction with a delay slot, and have seen a delay,
2700       // then back up and print it
2701       if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
2702         assert(delay != NULL, "no unconditional delay instruction");
2703         if (WizardMode) delay->dump();
2704 
2705         if (node_bundling(delay)->starts_bundle())
2706           starts_bundle = '+';
2707         if (pcs && n->_idx < pc_limit)
2708           tty->print("%3.3x", pcs[n->_idx]);
2709         else
2710           tty->print("   ");
2711         tty->print(" %c ", starts_bundle);
2712         starts_bundle = ' ';
2713         tty->print("\t");
2714         delay->format(_regalloc, tty);
2715         tty->cr();
2716         delay = NULL;
2717       }
2718 
2719       // Dump the exception table as well
2720       if( n->is_Catch() && (Verbose || WizardMode) ) {
2721         // Print the exception table for this offset
2722         _handler_table.print_subtable_for(pc);
2723       }
2724     }
2725 
2726     if (pcs && n->_idx < pc_limit)
2727       tty->print_cr("%3.3x", pcs[n->_idx]);
2728     else
2729       tty->cr();
2730 
2731     assert(cut_short || delay == NULL, "no unconditional delay branch");
2732 
2733   } // End of per-block dump
2734   tty->cr();
2735 
2736   if (cut_short)  tty->print_cr("*** disassembly is cut short ***");
2737 }
2738 #endif
2739 
2740 //------------------------------Final_Reshape_Counts---------------------------
2741 // This class defines counters to help identify when a method
2742 // may/must be executed using hardware with only 24-bit precision.
2743 struct Final_Reshape_Counts : public StackObj {
2744   int  _call_count;             // count non-inlined 'common' calls
2745   int  _float_count;            // count float ops requiring 24-bit precision
2746   int  _double_count;           // count double ops requiring more precision
2747   int  _java_call_count;        // count non-inlined 'java' calls
2748   int  _inner_loop_count;       // count loops which need alignment
2749   VectorSet _visited;           // Visitation flags
2750   Node_List _tests;             // Set of IfNodes & PCTableNodes
2751 
2752   Final_Reshape_Counts() :
2753     _call_count(0), _float_count(0), _double_count(0),
2754     _java_call_count(0), _inner_loop_count(0),
2755     _visited( Thread::current()->resource_area() ) { }
2756 
2757   void inc_call_count  () { _call_count  ++; }
2758   void inc_float_count () { _float_count ++; }
2759   void inc_double_count() { _double_count++; }
2760   void inc_java_call_count() { _java_call_count++; }
2761   void inc_inner_loop_count() { _inner_loop_count++; }
2762 
2763   int  get_call_count  () const { return _call_count  ; }
2764   int  get_float_count () const { return _float_count ; }
2765   int  get_double_count() const { return _double_count; }
2766   int  get_java_call_count() const { return _java_call_count; }
2767   int  get_inner_loop_count() const { return _inner_loop_count; }
2768 };
2769 
2770 #ifdef ASSERT
2771 static bool oop_offset_is_sane(const TypeInstPtr* tp) {
2772   ciInstanceKlass *k = tp->klass()->as_instance_klass();
2773   // Make sure the offset goes inside the instance layout.
2774   return k->contains_field_offset(tp->offset());
2775   // Note that OffsetBot and OffsetTop are very negative.
2776 }
2777 #endif
2778 
2779 // Eliminate trivially redundant StoreCMs and accumulate their
2780 // precedence edges.
2781 void Compile::eliminate_redundant_card_marks(Node* n) {
2782   assert(n->Opcode() == Op_StoreCM, "expected StoreCM");
2783   if (n->in(MemNode::Address)->outcnt() > 1) {
2784     // There are multiple users of the same address so it might be
2785     // possible to eliminate some of the StoreCMs
2786     Node* mem = n->in(MemNode::Memory);
2787     Node* adr = n->in(MemNode::Address);
2788     Node* val = n->in(MemNode::ValueIn);
2789     Node* prev = n;
2790     bool done = false;
2791     // Walk the chain of StoreCMs eliminating ones that match.  As
2792     // long as it's a chain of single users then the optimization is
2793     // safe.  Eliminating partially redundant StoreCMs would require
2794     // cloning copies down the other paths.
2795     while (mem->Opcode() == Op_StoreCM && mem->outcnt() == 1 && !done) {
2796       if (adr == mem->in(MemNode::Address) &&
2797           val == mem->in(MemNode::ValueIn)) {
2798         // redundant StoreCM
2799         if (mem->req() > MemNode::OopStore) {
2800           // Hasn't been processed by this code yet.
2801           n->add_prec(mem->in(MemNode::OopStore));
2802         } else {
2803           // Already converted to precedence edge
2804           for (uint i = mem->req(); i < mem->len(); i++) {
2805             // Accumulate any precedence edges
2806             if (mem->in(i) != NULL) {
2807               n->add_prec(mem->in(i));
2808             }
2809           }
2810           // Everything above this point has been processed.
2811           done = true;
2812         }
2813         // Eliminate the previous StoreCM
2814         prev->set_req(MemNode::Memory, mem->in(MemNode::Memory));
2815         assert(mem->outcnt() == 0, "should be dead");
2816         mem->disconnect_inputs(NULL, this);
2817       } else {
2818         prev = mem;
2819       }
2820       mem = prev->in(MemNode::Memory);
2821     }
2822   }
2823 }
2824 
2825 
2826 //------------------------------final_graph_reshaping_impl----------------------
2827 // Implement items 1-5 from final_graph_reshaping below.
2828 void Compile::final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &frc) {
2829 
2830   if ( n->outcnt() == 0 ) return; // dead node
2831   uint nop = n->Opcode();
2832 
2833   // Check for 2-input instruction with "last use" on right input.
2834   // Swap to left input.  Implements item (2).
2835   if( n->req() == 3 &&          // two-input instruction
2836       n->in(1)->outcnt() > 1 && // left use is NOT a last use
2837       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
2838       n->in(2)->outcnt() == 1 &&// right use IS a last use
2839       !n->in(2)->is_Con() ) {   // right use is not a constant
2840     // Check for commutative opcode
2841     switch( nop ) {
2842     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddL:
2843     case Op_MaxI:  case Op_MinI:
2844     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulL:
2845     case Op_AndL:  case Op_XorL:  case Op_OrL:
2846     case Op_AndI:  case Op_XorI:  case Op_OrI: {
2847       // Move "last use" input to left by swapping inputs
2848       n->swap_edges(1, 2);
2849       break;
2850     }
2851     default:
2852       break;
2853     }
2854   }
2855 
2856 #ifdef ASSERT
2857   if( n->is_Mem() ) {
2858     int alias_idx = get_alias_index(n->as_Mem()->adr_type());
2859     assert( n->in(0) != NULL || alias_idx != Compile::AliasIdxRaw ||
2860             // oop will be recorded in oop map if load crosses safepoint
2861             n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
2862                              LoadNode::is_immutable_value(n->in(MemNode::Address))),
2863             "raw memory operations should have control edge");
2864   }
2865   if (n->is_MemBar()) {
2866     MemBarNode* mb = n->as_MemBar();
2867     if (mb->trailing_store() || mb->trailing_load_store()) {
2868       assert(mb->leading_membar()->trailing_membar() == mb, "bad membar pair");
2869       Node* mem = mb->in(MemBarNode::Precedent);
2870       assert((mb->trailing_store() && mem->is_Store() && mem->as_Store()->is_release()) ||
2871              (mb->trailing_load_store() && mem->is_LoadStore()), "missing mem op");
2872     } else if (mb->leading()) {
2873       assert(mb->trailing_membar()->leading_membar() == mb, "bad membar pair");
2874     }
2875   }
2876 #endif
2877   // Count FPU ops and common calls, implements item (3)
2878   bool gc_handled = BarrierSet::barrier_set()->barrier_set_c2()->final_graph_reshaping(this, n, nop);
2879   if (!gc_handled) {
2880     final_graph_reshaping_main_switch(n, frc, nop);
2881   }
2882 
2883   // Collect CFG split points
2884   if (n->is_MultiBranch() && !n->is_RangeCheck()) {
2885     frc._tests.push(n);
2886   }
2887 }
2888 
2889 void Compile::final_graph_reshaping_main_switch(Node* n, Final_Reshape_Counts& frc, uint nop) {
2890   switch( nop ) {
2891   // Count all float operations that may use FPU
2892   case Op_AddF:
2893   case Op_SubF:
2894   case Op_MulF:
2895   case Op_DivF:
2896   case Op_NegF:
2897   case Op_ModF:
2898   case Op_ConvI2F:
2899   case Op_ConF:
2900   case Op_CmpF:
2901   case Op_CmpF3:
2902   // case Op_ConvL2F: // longs are split into 32-bit halves
2903     frc.inc_float_count();
2904     break;
2905 
2906   case Op_ConvF2D:
2907   case Op_ConvD2F:
2908     frc.inc_float_count();
2909     frc.inc_double_count();
2910     break;
2911 
2912   // Count all double operations that may use FPU
2913   case Op_AddD:
2914   case Op_SubD:
2915   case Op_MulD:
2916   case Op_DivD:
2917   case Op_NegD:
2918   case Op_ModD:
2919   case Op_ConvI2D:
2920   case Op_ConvD2I:
2921   // case Op_ConvL2D: // handled by leaf call
2922   // case Op_ConvD2L: // handled by leaf call
2923   case Op_ConD:
2924   case Op_CmpD:
2925   case Op_CmpD3:
2926     frc.inc_double_count();
2927     break;
2928   case Op_Opaque1:              // Remove Opaque Nodes before matching
2929   case Op_Opaque2:              // Remove Opaque Nodes before matching
2930   case Op_Opaque3:
2931     n->subsume_by(n->in(1), this);
2932     break;
2933   case Op_CallStaticJava:
2934   case Op_CallJava:
2935   case Op_CallDynamicJava:
2936     frc.inc_java_call_count(); // Count java call site;
2937   case Op_CallRuntime:
2938   case Op_CallLeaf:
2939   case Op_CallLeafNoFP: {
2940     assert (n->is_Call(), "");
2941     CallNode *call = n->as_Call();
2942     // Count call sites where the FP mode bit would have to be flipped.
2943     // Do not count uncommon runtime calls:
2944     // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
2945     // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
2946     if (!call->is_CallStaticJava() || !call->as_CallStaticJava()->_name) {
2947       frc.inc_call_count();   // Count the call site
2948     } else {                  // See if uncommon argument is shared
2949       Node *n = call->in(TypeFunc::Parms);
2950       int nop = n->Opcode();
2951       // Clone shared simple arguments to uncommon calls, item (1).
2952       if (n->outcnt() > 1 &&
2953           !n->is_Proj() &&
2954           nop != Op_CreateEx &&
2955           nop != Op_CheckCastPP &&
2956           nop != Op_DecodeN &&
2957           nop != Op_DecodeNKlass &&
2958           !n->is_Mem() &&
2959           !n->is_Phi()) {
2960         Node *x = n->clone();
2961         call->set_req(TypeFunc::Parms, x);
2962       }
2963     }
2964     break;
2965   }
2966 
2967   case Op_StoreD:
2968   case Op_LoadD:
2969   case Op_LoadD_unaligned:
2970     frc.inc_double_count();
2971     goto handle_mem;
2972   case Op_StoreF:
2973   case Op_LoadF:
2974     frc.inc_float_count();
2975     goto handle_mem;
2976 
2977   case Op_StoreCM:
2978     {
2979       // Convert OopStore dependence into precedence edge
2980       Node* prec = n->in(MemNode::OopStore);
2981       n->del_req(MemNode::OopStore);
2982       n->add_prec(prec);
2983       eliminate_redundant_card_marks(n);
2984     }
2985 
2986     // fall through
2987 
2988   case Op_StoreB:
2989   case Op_StoreC:
2990   case Op_StorePConditional:
2991   case Op_StoreI:
2992   case Op_StoreL:
2993   case Op_StoreIConditional:
2994   case Op_StoreLConditional:
2995   case Op_CompareAndSwapB:
2996   case Op_CompareAndSwapS:
2997   case Op_CompareAndSwapI:
2998   case Op_CompareAndSwapL:
2999   case Op_CompareAndSwapP:
3000   case Op_CompareAndSwapN:
3001   case Op_WeakCompareAndSwapB:
3002   case Op_WeakCompareAndSwapS:
3003   case Op_WeakCompareAndSwapI:
3004   case Op_WeakCompareAndSwapL:
3005   case Op_WeakCompareAndSwapP:
3006   case Op_WeakCompareAndSwapN:
3007   case Op_CompareAndExchangeB:
3008   case Op_CompareAndExchangeS:
3009   case Op_CompareAndExchangeI:
3010   case Op_CompareAndExchangeL:
3011   case Op_CompareAndExchangeP:
3012   case Op_CompareAndExchangeN:
3013   case Op_GetAndAddS:
3014   case Op_GetAndAddB:
3015   case Op_GetAndAddI:
3016   case Op_GetAndAddL:
3017   case Op_GetAndSetS:
3018   case Op_GetAndSetB:
3019   case Op_GetAndSetI:
3020   case Op_GetAndSetL:
3021   case Op_GetAndSetP:
3022   case Op_GetAndSetN:
3023   case Op_StoreP:
3024   case Op_StoreN:
3025   case Op_StoreNKlass:
3026   case Op_LoadB:
3027   case Op_LoadUB:
3028   case Op_LoadUS:
3029   case Op_LoadI:
3030   case Op_LoadKlass:
3031   case Op_LoadNKlass:
3032   case Op_LoadL:
3033   case Op_LoadL_unaligned:
3034   case Op_LoadPLocked:
3035   case Op_LoadP:
3036   case Op_LoadN:
3037   case Op_LoadRange:
3038   case Op_LoadS: {
3039   handle_mem:
3040 #ifdef ASSERT
3041     if( VerifyOptoOopOffsets ) {
3042       MemNode* mem  = n->as_Mem();
3043       // Check to see if address types have grounded out somehow.
3044       const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
3045       assert( !tp || oop_offset_is_sane(tp), "" );
3046     }
3047 #endif
3048     break;
3049   }
3050 
3051   case Op_AddP: {               // Assert sane base pointers
3052     Node *addp = n->in(AddPNode::Address);
3053     assert( !addp->is_AddP() ||
3054             addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
3055             addp->in(AddPNode::Base) == n->in(AddPNode::Base),
3056             "Base pointers must match (addp %u)", addp->_idx );
3057 #ifdef _LP64
3058     if ((UseCompressedOops || UseCompressedClassPointers) &&
3059         addp->Opcode() == Op_ConP &&
3060         addp == n->in(AddPNode::Base) &&
3061         n->in(AddPNode::Offset)->is_Con()) {
3062       // If the transformation of ConP to ConN+DecodeN is beneficial depends
3063       // on the platform and on the compressed oops mode.
3064       // Use addressing with narrow klass to load with offset on x86.
3065       // Some platforms can use the constant pool to load ConP.
3066       // Do this transformation here since IGVN will convert ConN back to ConP.
3067       const Type* t = addp->bottom_type();
3068       bool is_oop   = t->isa_oopptr() != NULL;
3069       bool is_klass = t->isa_klassptr() != NULL;
3070 
3071       if ((is_oop   && Matcher::const_oop_prefer_decode()  ) ||
3072           (is_klass && Matcher::const_klass_prefer_decode())) {
3073         Node* nn = NULL;
3074 
3075         int op = is_oop ? Op_ConN : Op_ConNKlass;
3076 
3077         // Look for existing ConN node of the same exact type.
3078         Node* r  = root();
3079         uint cnt = r->outcnt();
3080         for (uint i = 0; i < cnt; i++) {
3081           Node* m = r->raw_out(i);
3082           if (m!= NULL && m->Opcode() == op &&
3083               m->bottom_type()->make_ptr() == t) {
3084             nn = m;
3085             break;
3086           }
3087         }
3088         if (nn != NULL) {
3089           // Decode a narrow oop to match address
3090           // [R12 + narrow_oop_reg<<3 + offset]
3091           if (is_oop) {
3092             nn = new DecodeNNode(nn, t);
3093           } else {
3094             nn = new DecodeNKlassNode(nn, t);
3095           }
3096           // Check for succeeding AddP which uses the same Base.
3097           // Otherwise we will run into the assertion above when visiting that guy.
3098           for (uint i = 0; i < n->outcnt(); ++i) {
3099             Node *out_i = n->raw_out(i);
3100             if (out_i && out_i->is_AddP() && out_i->in(AddPNode::Base) == addp) {
3101               out_i->set_req(AddPNode::Base, nn);
3102 #ifdef ASSERT
3103               for (uint j = 0; j < out_i->outcnt(); ++j) {
3104                 Node *out_j = out_i->raw_out(j);
3105                 assert(out_j == NULL || !out_j->is_AddP() || out_j->in(AddPNode::Base) != addp,
3106                        "more than 2 AddP nodes in a chain (out_j %u)", out_j->_idx);
3107               }
3108 #endif
3109             }
3110           }
3111           n->set_req(AddPNode::Base, nn);
3112           n->set_req(AddPNode::Address, nn);
3113           if (addp->outcnt() == 0) {
3114             addp->disconnect_inputs(NULL, this);
3115           }
3116         }
3117       }
3118     }
3119 #endif
3120     // platform dependent reshaping of the address expression
3121     reshape_address(n->as_AddP());
3122     break;
3123   }
3124 
3125   case Op_CastPP: {
3126     // Remove CastPP nodes to gain more freedom during scheduling but
3127     // keep the dependency they encode as control or precedence edges
3128     // (if control is set already) on memory operations. Some CastPP
3129     // nodes don't have a control (don't carry a dependency): skip
3130     // those.
3131     if (n->in(0) != NULL) {
3132       ResourceMark rm;
3133       Unique_Node_List wq;
3134       wq.push(n);
3135       for (uint next = 0; next < wq.size(); ++next) {
3136         Node *m = wq.at(next);
3137         for (DUIterator_Fast imax, i = m->fast_outs(imax); i < imax; i++) {
3138           Node* use = m->fast_out(i);
3139           if (use->is_Mem() || use->is_EncodeNarrowPtr()) {
3140             use->ensure_control_or_add_prec(n->in(0));
3141           } else {
3142             switch(use->Opcode()) {
3143             case Op_AddP:
3144             case Op_DecodeN:
3145             case Op_DecodeNKlass:
3146             case Op_CheckCastPP:
3147             case Op_CastPP:
3148               wq.push(use);
3149               break;
3150             }
3151           }
3152         }
3153       }
3154     }
3155     const bool is_LP64 = LP64_ONLY(true) NOT_LP64(false);
3156     if (is_LP64 && n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
3157       Node* in1 = n->in(1);
3158       const Type* t = n->bottom_type();
3159       Node* new_in1 = in1->clone();
3160       new_in1->as_DecodeN()->set_type(t);
3161 
3162       if (!Matcher::narrow_oop_use_complex_address()) {
3163         //
3164         // x86, ARM and friends can handle 2 adds in addressing mode
3165         // and Matcher can fold a DecodeN node into address by using
3166         // a narrow oop directly and do implicit NULL check in address:
3167         //
3168         // [R12 + narrow_oop_reg<<3 + offset]
3169         // NullCheck narrow_oop_reg
3170         //
3171         // On other platforms (Sparc) we have to keep new DecodeN node and
3172         // use it to do implicit NULL check in address:
3173         //
3174         // decode_not_null narrow_oop_reg, base_reg
3175         // [base_reg + offset]
3176         // NullCheck base_reg
3177         //
3178         // Pin the new DecodeN node to non-null path on these platform (Sparc)
3179         // to keep the information to which NULL check the new DecodeN node
3180         // corresponds to use it as value in implicit_null_check().
3181         //
3182         new_in1->set_req(0, n->in(0));
3183       }
3184 
3185       n->subsume_by(new_in1, this);
3186       if (in1->outcnt() == 0) {
3187         in1->disconnect_inputs(NULL, this);
3188       }
3189     } else {
3190       n->subsume_by(n->in(1), this);
3191       if (n->outcnt() == 0) {
3192         n->disconnect_inputs(NULL, this);
3193       }
3194     }
3195     break;
3196   }
3197 #ifdef _LP64
3198   case Op_CmpP:
3199     // Do this transformation here to preserve CmpPNode::sub() and
3200     // other TypePtr related Ideal optimizations (for example, ptr nullness).
3201     if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
3202       Node* in1 = n->in(1);
3203       Node* in2 = n->in(2);
3204       if (!in1->is_DecodeNarrowPtr()) {
3205         in2 = in1;
3206         in1 = n->in(2);
3207       }
3208       assert(in1->is_DecodeNarrowPtr(), "sanity");
3209 
3210       Node* new_in2 = NULL;
3211       if (in2->is_DecodeNarrowPtr()) {
3212         assert(in2->Opcode() == in1->Opcode(), "must be same node type");
3213         new_in2 = in2->in(1);
3214       } else if (in2->Opcode() == Op_ConP) {
3215         const Type* t = in2->bottom_type();
3216         if (t == TypePtr::NULL_PTR) {
3217           assert(in1->is_DecodeN(), "compare klass to null?");
3218           // Don't convert CmpP null check into CmpN if compressed
3219           // oops implicit null check is not generated.
3220           // This will allow to generate normal oop implicit null check.
3221           if (Matcher::gen_narrow_oop_implicit_null_checks())
3222             new_in2 = ConNode::make(TypeNarrowOop::NULL_PTR);
3223           //
3224           // This transformation together with CastPP transformation above
3225           // will generated code for implicit NULL checks for compressed oops.
3226           //
3227           // The original code after Optimize()
3228           //
3229           //    LoadN memory, narrow_oop_reg
3230           //    decode narrow_oop_reg, base_reg
3231           //    CmpP base_reg, NULL
3232           //    CastPP base_reg // NotNull
3233           //    Load [base_reg + offset], val_reg
3234           //
3235           // after these transformations will be
3236           //
3237           //    LoadN memory, narrow_oop_reg
3238           //    CmpN narrow_oop_reg, NULL
3239           //    decode_not_null narrow_oop_reg, base_reg
3240           //    Load [base_reg + offset], val_reg
3241           //
3242           // and the uncommon path (== NULL) will use narrow_oop_reg directly
3243           // since narrow oops can be used in debug info now (see the code in
3244           // final_graph_reshaping_walk()).
3245           //
3246           // At the end the code will be matched to
3247           // on x86:
3248           //
3249           //    Load_narrow_oop memory, narrow_oop_reg
3250           //    Load [R12 + narrow_oop_reg<<3 + offset], val_reg
3251           //    NullCheck narrow_oop_reg
3252           //
3253           // and on sparc:
3254           //
3255           //    Load_narrow_oop memory, narrow_oop_reg
3256           //    decode_not_null narrow_oop_reg, base_reg
3257           //    Load [base_reg + offset], val_reg
3258           //    NullCheck base_reg
3259           //
3260         } else if (t->isa_oopptr()) {
3261           new_in2 = ConNode::make(t->make_narrowoop());
3262         } else if (t->isa_klassptr()) {
3263           new_in2 = ConNode::make(t->make_narrowklass());
3264         }
3265       }
3266       if (new_in2 != NULL) {
3267         Node* cmpN = new CmpNNode(in1->in(1), new_in2);
3268         n->subsume_by(cmpN, this);
3269         if (in1->outcnt() == 0) {
3270           in1->disconnect_inputs(NULL, this);
3271         }
3272         if (in2->outcnt() == 0) {
3273           in2->disconnect_inputs(NULL, this);
3274         }
3275       }
3276     }
3277     break;
3278 
3279   case Op_DecodeN:
3280   case Op_DecodeNKlass:
3281     assert(!n->in(1)->is_EncodeNarrowPtr(), "should be optimized out");
3282     // DecodeN could be pinned when it can't be fold into
3283     // an address expression, see the code for Op_CastPP above.
3284     assert(n->in(0) == NULL || (UseCompressedOops && !Matcher::narrow_oop_use_complex_address()), "no control");
3285     break;
3286 
3287   case Op_EncodeP:
3288   case Op_EncodePKlass: {
3289     Node* in1 = n->in(1);
3290     if (in1->is_DecodeNarrowPtr()) {
3291       n->subsume_by(in1->in(1), this);
3292     } else if (in1->Opcode() == Op_ConP) {
3293       const Type* t = in1->bottom_type();
3294       if (t == TypePtr::NULL_PTR) {
3295         assert(t->isa_oopptr(), "null klass?");
3296         n->subsume_by(ConNode::make(TypeNarrowOop::NULL_PTR), this);
3297       } else if (t->isa_oopptr()) {
3298         n->subsume_by(ConNode::make(t->make_narrowoop()), this);
3299       } else if (t->isa_klassptr()) {
3300         n->subsume_by(ConNode::make(t->make_narrowklass()), this);
3301       }
3302     }
3303     if (in1->outcnt() == 0) {
3304       in1->disconnect_inputs(NULL, this);
3305     }
3306     break;
3307   }
3308 
3309   case Op_Proj: {
3310     if (OptimizeStringConcat) {
3311       ProjNode* p = n->as_Proj();
3312       if (p->_is_io_use) {
3313         // Separate projections were used for the exception path which
3314         // are normally removed by a late inline.  If it wasn't inlined
3315         // then they will hang around and should just be replaced with
3316         // the original one.
3317         Node* proj = NULL;
3318         // Replace with just one
3319         for (SimpleDUIterator i(p->in(0)); i.has_next(); i.next()) {
3320           Node *use = i.get();
3321           if (use->is_Proj() && p != use && use->as_Proj()->_con == p->_con) {
3322             proj = use;
3323             break;
3324           }
3325         }
3326         assert(proj != NULL, "must be found");
3327         p->subsume_by(proj, this);
3328       }
3329     }
3330     break;
3331   }
3332 
3333   case Op_Phi:
3334     if (n->as_Phi()->bottom_type()->isa_narrowoop() || n->as_Phi()->bottom_type()->isa_narrowklass()) {
3335       // The EncodeP optimization may create Phi with the same edges
3336       // for all paths. It is not handled well by Register Allocator.
3337       Node* unique_in = n->in(1);
3338       assert(unique_in != NULL, "");
3339       uint cnt = n->req();
3340       for (uint i = 2; i < cnt; i++) {
3341         Node* m = n->in(i);
3342         assert(m != NULL, "");
3343         if (unique_in != m)
3344           unique_in = NULL;
3345       }
3346       if (unique_in != NULL) {
3347         n->subsume_by(unique_in, this);
3348       }
3349     }
3350     break;
3351 
3352 #endif
3353 
3354 #ifdef ASSERT
3355   case Op_CastII:
3356     // Verify that all range check dependent CastII nodes were removed.
3357     if (n->isa_CastII()->has_range_check()) {
3358       n->dump(3);
3359       assert(false, "Range check dependent CastII node was not removed");
3360     }
3361     break;
3362 #endif
3363 
3364   case Op_ModI:
3365     if (UseDivMod) {
3366       // Check if a%b and a/b both exist
3367       Node* d = n->find_similar(Op_DivI);
3368       if (d) {
3369         // Replace them with a fused divmod if supported
3370         if (Matcher::has_match_rule(Op_DivModI)) {
3371           DivModINode* divmod = DivModINode::make(n);
3372           d->subsume_by(divmod->div_proj(), this);
3373           n->subsume_by(divmod->mod_proj(), this);
3374         } else {
3375           // replace a%b with a-((a/b)*b)
3376           Node* mult = new MulINode(d, d->in(2));
3377           Node* sub  = new SubINode(d->in(1), mult);
3378           n->subsume_by(sub, this);
3379         }
3380       }
3381     }
3382     break;
3383 
3384   case Op_ModL:
3385     if (UseDivMod) {
3386       // Check if a%b and a/b both exist
3387       Node* d = n->find_similar(Op_DivL);
3388       if (d) {
3389         // Replace them with a fused divmod if supported
3390         if (Matcher::has_match_rule(Op_DivModL)) {
3391           DivModLNode* divmod = DivModLNode::make(n);
3392           d->subsume_by(divmod->div_proj(), this);
3393           n->subsume_by(divmod->mod_proj(), this);
3394         } else {
3395           // replace a%b with a-((a/b)*b)
3396           Node* mult = new MulLNode(d, d->in(2));
3397           Node* sub  = new SubLNode(d->in(1), mult);
3398           n->subsume_by(sub, this);
3399         }
3400       }
3401     }
3402     break;
3403 
3404   case Op_LoadVector:
3405   case Op_StoreVector:
3406     break;
3407 
3408   case Op_AddReductionVI:
3409   case Op_AddReductionVL:
3410   case Op_AddReductionVF:
3411   case Op_AddReductionVD:
3412   case Op_MulReductionVI:
3413   case Op_MulReductionVL:
3414   case Op_MulReductionVF:
3415   case Op_MulReductionVD:
3416     break;
3417 
3418   case Op_PackB:
3419   case Op_PackS:
3420   case Op_PackI:
3421   case Op_PackF:
3422   case Op_PackL:
3423   case Op_PackD:
3424     if (n->req()-1 > 2) {
3425       // Replace many operand PackNodes with a binary tree for matching
3426       PackNode* p = (PackNode*) n;
3427       Node* btp = p->binary_tree_pack(1, n->req());
3428       n->subsume_by(btp, this);
3429     }
3430     break;
3431   case Op_Loop:
3432   case Op_CountedLoop:
3433   case Op_OuterStripMinedLoop:
3434     if (n->as_Loop()->is_inner_loop()) {
3435       frc.inc_inner_loop_count();
3436     }
3437     n->as_Loop()->verify_strip_mined(0);
3438     break;
3439   case Op_LShiftI:
3440   case Op_RShiftI:
3441   case Op_URShiftI:
3442   case Op_LShiftL:
3443   case Op_RShiftL:
3444   case Op_URShiftL:
3445     if (Matcher::need_masked_shift_count) {
3446       // The cpu's shift instructions don't restrict the count to the
3447       // lower 5/6 bits. We need to do the masking ourselves.
3448       Node* in2 = n->in(2);
3449       juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
3450       const TypeInt* t = in2->find_int_type();
3451       if (t != NULL && t->is_con()) {
3452         juint shift = t->get_con();
3453         if (shift > mask) { // Unsigned cmp
3454           n->set_req(2, ConNode::make(TypeInt::make(shift & mask)));
3455         }
3456       } else {
3457         if (t == NULL || t->_lo < 0 || t->_hi > (int)mask) {
3458           Node* shift = new AndINode(in2, ConNode::make(TypeInt::make(mask)));
3459           n->set_req(2, shift);
3460         }
3461       }
3462       if (in2->outcnt() == 0) { // Remove dead node
3463         in2->disconnect_inputs(NULL, this);
3464       }
3465     }
3466     break;
3467   case Op_MemBarStoreStore:
3468   case Op_MemBarRelease:
3469     // Break the link with AllocateNode: it is no longer useful and
3470     // confuses register allocation.
3471     if (n->req() > MemBarNode::Precedent) {
3472       n->set_req(MemBarNode::Precedent, top());
3473     }
3474     break;
3475   case Op_MemBarAcquire: {
3476     if (n->as_MemBar()->trailing_load() && n->req() > MemBarNode::Precedent) {
3477       // At parse time, the trailing MemBarAcquire for a volatile load
3478       // is created with an edge to the load. After optimizations,
3479       // that input may be a chain of Phis. If those phis have no
3480       // other use, then the MemBarAcquire keeps them alive and
3481       // register allocation can be confused.
3482       ResourceMark rm;
3483       Unique_Node_List wq;
3484       wq.push(n->in(MemBarNode::Precedent));
3485       n->set_req(MemBarNode::Precedent, top());
3486       while (wq.size() > 0) {
3487         Node* m = wq.pop();
3488         if (m->outcnt() == 0) {
3489           for (uint j = 0; j < m->req(); j++) {
3490             Node* in = m->in(j);
3491             if (in != NULL) {
3492               wq.push(in);
3493             }
3494           }
3495           m->disconnect_inputs(NULL, this);
3496         }
3497       }
3498     }
3499     break;
3500   }
3501   case Op_RangeCheck: {
3502     RangeCheckNode* rc = n->as_RangeCheck();
3503     Node* iff = new IfNode(rc->in(0), rc->in(1), rc->_prob, rc->_fcnt);
3504     n->subsume_by(iff, this);
3505     frc._tests.push(iff);
3506     break;
3507   }
3508   case Op_ConvI2L: {
3509     if (!Matcher::convi2l_type_required) {
3510       // Code generation on some platforms doesn't need accurate
3511       // ConvI2L types. Widening the type can help remove redundant
3512       // address computations.
3513       n->as_Type()->set_type(TypeLong::INT);
3514       ResourceMark rm;
3515       Node_List wq;
3516       wq.push(n);
3517       for (uint next = 0; next < wq.size(); next++) {
3518         Node *m = wq.at(next);
3519 
3520         for(;;) {
3521           // Loop over all nodes with identical inputs edges as m
3522           Node* k = m->find_similar(m->Opcode());
3523           if (k == NULL) {
3524             break;
3525           }
3526           // Push their uses so we get a chance to remove node made
3527           // redundant
3528           for (DUIterator_Fast imax, i = k->fast_outs(imax); i < imax; i++) {
3529             Node* u = k->fast_out(i);
3530             assert(!wq.contains(u), "shouldn't process one node several times");
3531             if (u->Opcode() == Op_LShiftL ||
3532                 u->Opcode() == Op_AddL ||
3533                 u->Opcode() == Op_SubL ||
3534                 u->Opcode() == Op_AddP) {
3535               wq.push(u);
3536             }
3537           }
3538           // Replace all nodes with identical edges as m with m
3539           k->subsume_by(m, this);
3540         }
3541       }
3542     }
3543     break;
3544   }
3545   case Op_CmpUL: {
3546     if (!Matcher::has_match_rule(Op_CmpUL)) {
3547       // We don't support unsigned long comparisons. Set 'max_idx_expr'
3548       // to max_julong if < 0 to make the signed comparison fail.
3549       ConINode* sign_pos = new ConINode(TypeInt::make(BitsPerLong - 1));
3550       Node* sign_bit_mask = new RShiftLNode(n->in(1), sign_pos);
3551       Node* orl = new OrLNode(n->in(1), sign_bit_mask);
3552       ConLNode* remove_sign_mask = new ConLNode(TypeLong::make(max_jlong));
3553       Node* andl = new AndLNode(orl, remove_sign_mask);
3554       Node* cmp = new CmpLNode(andl, n->in(2));
3555       n->subsume_by(cmp, this);
3556     }
3557     break;
3558   }
3559 #ifdef ASSERT
3560   case Op_ValueTypePtr:
3561   case Op_ValueType: {
3562     n->dump(-1);
3563     assert(false, "value type node was not removed");
3564     break;
3565   }
3566 #endif
3567   default:
3568     assert(!n->is_Call(), "");
3569     assert(!n->is_Mem(), "");
3570     assert(nop != Op_ProfileBoolean, "should be eliminated during IGVN");
3571     break;
3572   }
3573 }
3574 
3575 //------------------------------final_graph_reshaping_walk---------------------
3576 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
3577 // requires that the walk visits a node's inputs before visiting the node.
3578 void Compile::final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Reshape_Counts &frc ) {
3579   ResourceArea *area = Thread::current()->resource_area();
3580   Unique_Node_List sfpt(area);
3581 
3582   frc._visited.set(root->_idx); // first, mark node as visited
3583   uint cnt = root->req();
3584   Node *n = root;
3585   uint  i = 0;
3586   while (true) {
3587     if (i < cnt) {
3588       // Place all non-visited non-null inputs onto stack
3589       Node* m = n->in(i);
3590       ++i;
3591       if (m != NULL && !frc._visited.test_set(m->_idx)) {
3592         if (m->is_SafePoint() && m->as_SafePoint()->jvms() != NULL) {
3593           // compute worst case interpreter size in case of a deoptimization
3594           update_interpreter_frame_size(m->as_SafePoint()->jvms()->interpreter_frame_size());
3595 
3596           sfpt.push(m);
3597         }
3598         cnt = m->req();
3599         nstack.push(n, i); // put on stack parent and next input's index
3600         n = m;
3601         i = 0;
3602       }
3603     } else {
3604       // Now do post-visit work
3605       final_graph_reshaping_impl( n, frc );
3606       if (nstack.is_empty())
3607         break;             // finished
3608       n = nstack.node();   // Get node from stack
3609       cnt = n->req();
3610       i = nstack.index();
3611       nstack.pop();        // Shift to the next node on stack
3612     }
3613   }
3614 
3615   // Skip next transformation if compressed oops are not used.
3616   if ((UseCompressedOops && !Matcher::gen_narrow_oop_implicit_null_checks()) ||
3617       (!UseCompressedOops && !UseCompressedClassPointers))
3618     return;
3619 
3620   // Go over safepoints nodes to skip DecodeN/DecodeNKlass nodes for debug edges.
3621   // It could be done for an uncommon traps or any safepoints/calls
3622   // if the DecodeN/DecodeNKlass node is referenced only in a debug info.
3623   while (sfpt.size() > 0) {
3624     n = sfpt.pop();
3625     JVMState *jvms = n->as_SafePoint()->jvms();
3626     assert(jvms != NULL, "sanity");
3627     int start = jvms->debug_start();
3628     int end   = n->req();
3629     bool is_uncommon = (n->is_CallStaticJava() &&
3630                         n->as_CallStaticJava()->uncommon_trap_request() != 0);
3631     for (int j = start; j < end; j++) {
3632       Node* in = n->in(j);
3633       if (in->is_DecodeNarrowPtr()) {
3634         bool safe_to_skip = true;
3635         if (!is_uncommon ) {
3636           // Is it safe to skip?
3637           for (uint i = 0; i < in->outcnt(); i++) {
3638             Node* u = in->raw_out(i);
3639             if (!u->is_SafePoint() ||
3640                 (u->is_Call() && u->as_Call()->has_non_debug_use(n))) {
3641               safe_to_skip = false;
3642             }
3643           }
3644         }
3645         if (safe_to_skip) {
3646           n->set_req(j, in->in(1));
3647         }
3648         if (in->outcnt() == 0) {
3649           in->disconnect_inputs(NULL, this);
3650         }
3651       }
3652     }
3653   }
3654 }
3655 
3656 //------------------------------final_graph_reshaping--------------------------
3657 // Final Graph Reshaping.
3658 //
3659 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
3660 //     and not commoned up and forced early.  Must come after regular
3661 //     optimizations to avoid GVN undoing the cloning.  Clone constant
3662 //     inputs to Loop Phis; these will be split by the allocator anyways.
3663 //     Remove Opaque nodes.
3664 // (2) Move last-uses by commutative operations to the left input to encourage
3665 //     Intel update-in-place two-address operations and better register usage
3666 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
3667 //     calls canonicalizing them back.
3668 // (3) Count the number of double-precision FP ops, single-precision FP ops
3669 //     and call sites.  On Intel, we can get correct rounding either by
3670 //     forcing singles to memory (requires extra stores and loads after each
3671 //     FP bytecode) or we can set a rounding mode bit (requires setting and
3672 //     clearing the mode bit around call sites).  The mode bit is only used
3673 //     if the relative frequency of single FP ops to calls is low enough.
3674 //     This is a key transform for SPEC mpeg_audio.
3675 // (4) Detect infinite loops; blobs of code reachable from above but not
3676 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
3677 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
3678 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
3679 //     Detection is by looking for IfNodes where only 1 projection is
3680 //     reachable from below or CatchNodes missing some targets.
3681 // (5) Assert for insane oop offsets in debug mode.
3682 
3683 bool Compile::final_graph_reshaping() {
3684   // an infinite loop may have been eliminated by the optimizer,
3685   // in which case the graph will be empty.
3686   if (root()->req() == 1) {
3687     record_method_not_compilable("trivial infinite loop");
3688     return true;
3689   }
3690 
3691   // Expensive nodes have their control input set to prevent the GVN
3692   // from freely commoning them. There's no GVN beyond this point so
3693   // no need to keep the control input. We want the expensive nodes to
3694   // be freely moved to the least frequent code path by gcm.
3695   assert(OptimizeExpensiveOps || expensive_count() == 0, "optimization off but list non empty?");
3696   for (int i = 0; i < expensive_count(); i++) {
3697     _expensive_nodes->at(i)->set_req(0, NULL);
3698   }
3699 
3700   Final_Reshape_Counts frc;
3701 
3702   // Visit everybody reachable!
3703   // Allocate stack of size C->live_nodes()/2 to avoid frequent realloc
3704   Node_Stack nstack(live_nodes() >> 1);
3705   final_graph_reshaping_walk(nstack, root(), frc);
3706 
3707   // Check for unreachable (from below) code (i.e., infinite loops).
3708   for( uint i = 0; i < frc._tests.size(); i++ ) {
3709     MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
3710     // Get number of CFG targets.
3711     // Note that PCTables include exception targets after calls.
3712     uint required_outcnt = n->required_outcnt();
3713     if (n->outcnt() != required_outcnt) {
3714       // Check for a few special cases.  Rethrow Nodes never take the
3715       // 'fall-thru' path, so expected kids is 1 less.
3716       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
3717         if (n->in(0)->in(0)->is_Call()) {
3718           CallNode *call = n->in(0)->in(0)->as_Call();
3719           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
3720             required_outcnt--;      // Rethrow always has 1 less kid
3721           } else if (call->req() > TypeFunc::Parms &&
3722                      call->is_CallDynamicJava()) {
3723             // Check for null receiver. In such case, the optimizer has
3724             // detected that the virtual call will always result in a null
3725             // pointer exception. The fall-through projection of this CatchNode
3726             // will not be populated.
3727             Node *arg0 = call->in(TypeFunc::Parms);
3728             if (arg0->is_Type() &&
3729                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
3730               required_outcnt--;
3731             }
3732           } else if (call->entry_point() == OptoRuntime::new_array_Java() &&
3733                      call->req() > TypeFunc::Parms+1 &&
3734                      call->is_CallStaticJava()) {
3735             // Check for negative array length. In such case, the optimizer has
3736             // detected that the allocation attempt will always result in an
3737             // exception. There is no fall-through projection of this CatchNode .
3738             Node *arg1 = call->in(TypeFunc::Parms+1);
3739             if (arg1->is_Type() &&
3740                 arg1->as_Type()->type()->join(TypeInt::POS)->empty()) {
3741               required_outcnt--;
3742             }
3743           }
3744         }
3745       }
3746       // Recheck with a better notion of 'required_outcnt'
3747       if (n->outcnt() != required_outcnt) {
3748         record_method_not_compilable("malformed control flow");
3749         return true;            // Not all targets reachable!
3750       }
3751     }
3752     // Check that I actually visited all kids.  Unreached kids
3753     // must be infinite loops.
3754     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
3755       if (!frc._visited.test(n->fast_out(j)->_idx)) {
3756         record_method_not_compilable("infinite loop");
3757         return true;            // Found unvisited kid; must be unreach
3758       }
3759 
3760     // Here so verification code in final_graph_reshaping_walk()
3761     // always see an OuterStripMinedLoopEnd
3762     if (n->is_OuterStripMinedLoopEnd()) {
3763       IfNode* init_iff = n->as_If();
3764       Node* iff = new IfNode(init_iff->in(0), init_iff->in(1), init_iff->_prob, init_iff->_fcnt);
3765       n->subsume_by(iff, this);
3766     }
3767   }
3768 
3769   // If original bytecodes contained a mixture of floats and doubles
3770   // check if the optimizer has made it homogenous, item (3).
3771   if( Use24BitFPMode && Use24BitFP && UseSSE == 0 &&
3772       frc.get_float_count() > 32 &&
3773       frc.get_double_count() == 0 &&
3774       (10 * frc.get_call_count() < frc.get_float_count()) ) {
3775     set_24_bit_selection_and_mode( false,  true );
3776   }
3777 
3778   set_java_calls(frc.get_java_call_count());
3779   set_inner_loops(frc.get_inner_loop_count());
3780 
3781   // No infinite loops, no reason to bail out.
3782   return false;
3783 }
3784 
3785 //-----------------------------too_many_traps----------------------------------
3786 // Report if there are too many traps at the current method and bci.
3787 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
3788 bool Compile::too_many_traps(ciMethod* method,
3789                              int bci,
3790                              Deoptimization::DeoptReason reason) {
3791   ciMethodData* md = method->method_data();
3792   if (md->is_empty()) {
3793     // Assume the trap has not occurred, or that it occurred only
3794     // because of a transient condition during start-up in the interpreter.
3795     return false;
3796   }
3797   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
3798   if (md->has_trap_at(bci, m, reason) != 0) {
3799     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
3800     // Also, if there are multiple reasons, or if there is no per-BCI record,
3801     // assume the worst.
3802     if (log())
3803       log()->elem("observe trap='%s' count='%d'",
3804                   Deoptimization::trap_reason_name(reason),
3805                   md->trap_count(reason));
3806     return true;
3807   } else {
3808     // Ignore method/bci and see if there have been too many globally.
3809     return too_many_traps(reason, md);
3810   }
3811 }
3812 
3813 // Less-accurate variant which does not require a method and bci.
3814 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
3815                              ciMethodData* logmd) {
3816   if (trap_count(reason) >= Deoptimization::per_method_trap_limit(reason)) {
3817     // Too many traps globally.
3818     // Note that we use cumulative trap_count, not just md->trap_count.
3819     if (log()) {
3820       int mcount = (logmd == NULL)? -1: (int)logmd->trap_count(reason);
3821       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
3822                   Deoptimization::trap_reason_name(reason),
3823                   mcount, trap_count(reason));
3824     }
3825     return true;
3826   } else {
3827     // The coast is clear.
3828     return false;
3829   }
3830 }
3831 
3832 //--------------------------too_many_recompiles--------------------------------
3833 // Report if there are too many recompiles at the current method and bci.
3834 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
3835 // Is not eager to return true, since this will cause the compiler to use
3836 // Action_none for a trap point, to avoid too many recompilations.
3837 bool Compile::too_many_recompiles(ciMethod* method,
3838                                   int bci,
3839                                   Deoptimization::DeoptReason reason) {
3840   ciMethodData* md = method->method_data();
3841   if (md->is_empty()) {
3842     // Assume the trap has not occurred, or that it occurred only
3843     // because of a transient condition during start-up in the interpreter.
3844     return false;
3845   }
3846   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
3847   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
3848   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
3849   Deoptimization::DeoptReason per_bc_reason
3850     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
3851   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
3852   if ((per_bc_reason == Deoptimization::Reason_none
3853        || md->has_trap_at(bci, m, reason) != 0)
3854       // The trap frequency measure we care about is the recompile count:
3855       && md->trap_recompiled_at(bci, m)
3856       && md->overflow_recompile_count() >= bc_cutoff) {
3857     // Do not emit a trap here if it has already caused recompilations.
3858     // Also, if there are multiple reasons, or if there is no per-BCI record,
3859     // assume the worst.
3860     if (log())
3861       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
3862                   Deoptimization::trap_reason_name(reason),
3863                   md->trap_count(reason),
3864                   md->overflow_recompile_count());
3865     return true;
3866   } else if (trap_count(reason) != 0
3867              && decompile_count() >= m_cutoff) {
3868     // Too many recompiles globally, and we have seen this sort of trap.
3869     // Use cumulative decompile_count, not just md->decompile_count.
3870     if (log())
3871       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
3872                   Deoptimization::trap_reason_name(reason),
3873                   md->trap_count(reason), trap_count(reason),
3874                   md->decompile_count(), decompile_count());
3875     return true;
3876   } else {
3877     // The coast is clear.
3878     return false;
3879   }
3880 }
3881 
3882 // Compute when not to trap. Used by matching trap based nodes and
3883 // NullCheck optimization.
3884 void Compile::set_allowed_deopt_reasons() {
3885   _allowed_reasons = 0;
3886   if (is_method_compilation()) {
3887     for (int rs = (int)Deoptimization::Reason_none+1; rs < Compile::trapHistLength; rs++) {
3888       assert(rs < BitsPerInt, "recode bit map");
3889       if (!too_many_traps((Deoptimization::DeoptReason) rs)) {
3890         _allowed_reasons |= nth_bit(rs);
3891       }
3892     }
3893   }
3894 }
3895 
3896 #ifndef PRODUCT
3897 //------------------------------verify_graph_edges---------------------------
3898 // Walk the Graph and verify that there is a one-to-one correspondence
3899 // between Use-Def edges and Def-Use edges in the graph.
3900 void Compile::verify_graph_edges(bool no_dead_code) {
3901   if (VerifyGraphEdges) {
3902     ResourceArea *area = Thread::current()->resource_area();
3903     Unique_Node_List visited(area);
3904     // Call recursive graph walk to check edges
3905     _root->verify_edges(visited);
3906     if (no_dead_code) {
3907       // Now make sure that no visited node is used by an unvisited node.
3908       bool dead_nodes = false;
3909       Unique_Node_List checked(area);
3910       while (visited.size() > 0) {
3911         Node* n = visited.pop();
3912         checked.push(n);
3913         for (uint i = 0; i < n->outcnt(); i++) {
3914           Node* use = n->raw_out(i);
3915           if (checked.member(use))  continue;  // already checked
3916           if (visited.member(use))  continue;  // already in the graph
3917           if (use->is_Con())        continue;  // a dead ConNode is OK
3918           // At this point, we have found a dead node which is DU-reachable.
3919           if (!dead_nodes) {
3920             tty->print_cr("*** Dead nodes reachable via DU edges:");
3921             dead_nodes = true;
3922           }
3923           use->dump(2);
3924           tty->print_cr("---");
3925           checked.push(use);  // No repeats; pretend it is now checked.
3926         }
3927       }
3928       assert(!dead_nodes, "using nodes must be reachable from root");
3929     }
3930   }
3931 }
3932 #endif
3933 
3934 // The Compile object keeps track of failure reasons separately from the ciEnv.
3935 // This is required because there is not quite a 1-1 relation between the
3936 // ciEnv and its compilation task and the Compile object.  Note that one
3937 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
3938 // to backtrack and retry without subsuming loads.  Other than this backtracking
3939 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
3940 // by the logic in C2Compiler.
3941 void Compile::record_failure(const char* reason) {
3942   if (log() != NULL) {
3943     log()->elem("failure reason='%s' phase='compile'", reason);
3944   }
3945   if (_failure_reason == NULL) {
3946     // Record the first failure reason.
3947     _failure_reason = reason;
3948   }
3949 
3950   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
3951     C->print_method(PHASE_FAILURE);
3952   }
3953   _root = NULL;  // flush the graph, too
3954 }
3955 
3956 Compile::TracePhase::TracePhase(const char* name, elapsedTimer* accumulator)
3957   : TraceTime(name, accumulator, CITime, CITimeVerbose),
3958     _phase_name(name), _dolog(CITimeVerbose)
3959 {
3960   if (_dolog) {
3961     C = Compile::current();
3962     _log = C->log();
3963   } else {
3964     C = NULL;
3965     _log = NULL;
3966   }
3967   if (_log != NULL) {
3968     _log->begin_head("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
3969     _log->stamp();
3970     _log->end_head();
3971   }
3972 }
3973 
3974 Compile::TracePhase::~TracePhase() {
3975 
3976   C = Compile::current();
3977   if (_dolog) {
3978     _log = C->log();
3979   } else {
3980     _log = NULL;
3981   }
3982 
3983 #ifdef ASSERT
3984   if (PrintIdealNodeCount) {
3985     tty->print_cr("phase name='%s' nodes='%d' live='%d' live_graph_walk='%d'",
3986                   _phase_name, C->unique(), C->live_nodes(), C->count_live_nodes_by_graph_walk());
3987   }
3988 
3989   if (VerifyIdealNodeCount) {
3990     Compile::current()->print_missing_nodes();
3991   }
3992 #endif
3993 
3994   if (_log != NULL) {
3995     _log->done("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
3996   }
3997 }
3998 
3999 //=============================================================================
4000 // Two Constant's are equal when the type and the value are equal.
4001 bool Compile::Constant::operator==(const Constant& other) {
4002   if (type()          != other.type()         )  return false;
4003   if (can_be_reused() != other.can_be_reused())  return false;
4004   // For floating point values we compare the bit pattern.
4005   switch (type()) {
4006   case T_INT:
4007   case T_FLOAT:   return (_v._value.i == other._v._value.i);
4008   case T_LONG:
4009   case T_DOUBLE:  return (_v._value.j == other._v._value.j);
4010   case T_OBJECT:
4011   case T_ADDRESS: return (_v._value.l == other._v._value.l);
4012   case T_VOID:    return (_v._value.l == other._v._value.l);  // jump-table entries
4013   case T_METADATA: return (_v._metadata == other._v._metadata);
4014   default: ShouldNotReachHere(); return false;
4015   }
4016 }
4017 
4018 static int type_to_size_in_bytes(BasicType t) {
4019   switch (t) {
4020   case T_INT:     return sizeof(jint   );
4021   case T_LONG:    return sizeof(jlong  );
4022   case T_FLOAT:   return sizeof(jfloat );
4023   case T_DOUBLE:  return sizeof(jdouble);
4024   case T_METADATA: return sizeof(Metadata*);
4025     // We use T_VOID as marker for jump-table entries (labels) which
4026     // need an internal word relocation.
4027   case T_VOID:
4028   case T_ADDRESS:
4029   case T_OBJECT:  return sizeof(jobject);
4030   default:
4031     ShouldNotReachHere();
4032     return -1;
4033   }
4034 }
4035 
4036 int Compile::ConstantTable::qsort_comparator(Constant* a, Constant* b) {
4037   // sort descending
4038   if (a->freq() > b->freq())  return -1;
4039   if (a->freq() < b->freq())  return  1;
4040   return 0;
4041 }
4042 
4043 void Compile::ConstantTable::calculate_offsets_and_size() {
4044   // First, sort the array by frequencies.
4045   _constants.sort(qsort_comparator);
4046 
4047 #ifdef ASSERT
4048   // Make sure all jump-table entries were sorted to the end of the
4049   // array (they have a negative frequency).
4050   bool found_void = false;
4051   for (int i = 0; i < _constants.length(); i++) {
4052     Constant con = _constants.at(i);
4053     if (con.type() == T_VOID)
4054       found_void = true;  // jump-tables
4055     else
4056       assert(!found_void, "wrong sorting");
4057   }
4058 #endif
4059 
4060   int offset = 0;
4061   for (int i = 0; i < _constants.length(); i++) {
4062     Constant* con = _constants.adr_at(i);
4063 
4064     // Align offset for type.
4065     int typesize = type_to_size_in_bytes(con->type());
4066     offset = align_up(offset, typesize);
4067     con->set_offset(offset);   // set constant's offset
4068 
4069     if (con->type() == T_VOID) {
4070       MachConstantNode* n = (MachConstantNode*) con->get_jobject();
4071       offset = offset + typesize * n->outcnt();  // expand jump-table
4072     } else {
4073       offset = offset + typesize;
4074     }
4075   }
4076 
4077   // Align size up to the next section start (which is insts; see
4078   // CodeBuffer::align_at_start).
4079   assert(_size == -1, "already set?");
4080   _size = align_up(offset, (int)CodeEntryAlignment);
4081 }
4082 
4083 void Compile::ConstantTable::emit(CodeBuffer& cb) {
4084   MacroAssembler _masm(&cb);
4085   for (int i = 0; i < _constants.length(); i++) {
4086     Constant con = _constants.at(i);
4087     address constant_addr = NULL;
4088     switch (con.type()) {
4089     case T_INT:    constant_addr = _masm.int_constant(   con.get_jint()   ); break;
4090     case T_LONG:   constant_addr = _masm.long_constant(  con.get_jlong()  ); break;
4091     case T_FLOAT:  constant_addr = _masm.float_constant( con.get_jfloat() ); break;
4092     case T_DOUBLE: constant_addr = _masm.double_constant(con.get_jdouble()); break;
4093     case T_OBJECT: {
4094       jobject obj = con.get_jobject();
4095       int oop_index = _masm.oop_recorder()->find_index(obj);
4096       constant_addr = _masm.address_constant((address) obj, oop_Relocation::spec(oop_index));
4097       break;
4098     }
4099     case T_ADDRESS: {
4100       address addr = (address) con.get_jobject();
4101       constant_addr = _masm.address_constant(addr);
4102       break;
4103     }
4104     // We use T_VOID as marker for jump-table entries (labels) which
4105     // need an internal word relocation.
4106     case T_VOID: {
4107       MachConstantNode* n = (MachConstantNode*) con.get_jobject();
4108       // Fill the jump-table with a dummy word.  The real value is
4109       // filled in later in fill_jump_table.
4110       address dummy = (address) n;
4111       constant_addr = _masm.address_constant(dummy);
4112       // Expand jump-table
4113       for (uint i = 1; i < n->outcnt(); i++) {
4114         address temp_addr = _masm.address_constant(dummy + i);
4115         assert(temp_addr, "consts section too small");
4116       }
4117       break;
4118     }
4119     case T_METADATA: {
4120       Metadata* obj = con.get_metadata();
4121       int metadata_index = _masm.oop_recorder()->find_index(obj);
4122       constant_addr = _masm.address_constant((address) obj, metadata_Relocation::spec(metadata_index));
4123       break;
4124     }
4125     default: ShouldNotReachHere();
4126     }
4127     assert(constant_addr, "consts section too small");
4128     assert((constant_addr - _masm.code()->consts()->start()) == con.offset(),
4129             "must be: %d == %d", (int) (constant_addr - _masm.code()->consts()->start()), (int)(con.offset()));
4130   }
4131 }
4132 
4133 int Compile::ConstantTable::find_offset(Constant& con) const {
4134   int idx = _constants.find(con);
4135   guarantee(idx != -1, "constant must be in constant table");
4136   int offset = _constants.at(idx).offset();
4137   guarantee(offset != -1, "constant table not emitted yet?");
4138   return offset;
4139 }
4140 
4141 void Compile::ConstantTable::add(Constant& con) {
4142   if (con.can_be_reused()) {
4143     int idx = _constants.find(con);
4144     if (idx != -1 && _constants.at(idx).can_be_reused()) {
4145       _constants.adr_at(idx)->inc_freq(con.freq());  // increase the frequency by the current value
4146       return;
4147     }
4148   }
4149   (void) _constants.append(con);
4150 }
4151 
4152 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, BasicType type, jvalue value) {
4153   Block* b = Compile::current()->cfg()->get_block_for_node(n);
4154   Constant con(type, value, b->_freq);
4155   add(con);
4156   return con;
4157 }
4158 
4159 Compile::Constant Compile::ConstantTable::add(Metadata* metadata) {
4160   Constant con(metadata);
4161   add(con);
4162   return con;
4163 }
4164 
4165 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, MachOper* oper) {
4166   jvalue value;
4167   BasicType type = oper->type()->basic_type();
4168   switch (type) {
4169   case T_LONG:    value.j = oper->constantL(); break;
4170   case T_FLOAT:   value.f = oper->constantF(); break;
4171   case T_DOUBLE:  value.d = oper->constantD(); break;
4172   case T_OBJECT:
4173   case T_ADDRESS: value.l = (jobject) oper->constant(); break;
4174   case T_METADATA: return add((Metadata*)oper->constant()); break;
4175   default: guarantee(false, "unhandled type: %s", type2name(type));
4176   }
4177   return add(n, type, value);
4178 }
4179 
4180 Compile::Constant Compile::ConstantTable::add_jump_table(MachConstantNode* n) {
4181   jvalue value;
4182   // We can use the node pointer here to identify the right jump-table
4183   // as this method is called from Compile::Fill_buffer right before
4184   // the MachNodes are emitted and the jump-table is filled (means the
4185   // MachNode pointers do not change anymore).
4186   value.l = (jobject) n;
4187   Constant con(T_VOID, value, next_jump_table_freq(), false);  // Labels of a jump-table cannot be reused.
4188   add(con);
4189   return con;
4190 }
4191 
4192 void Compile::ConstantTable::fill_jump_table(CodeBuffer& cb, MachConstantNode* n, GrowableArray<Label*> labels) const {
4193   // If called from Compile::scratch_emit_size do nothing.
4194   if (Compile::current()->in_scratch_emit_size())  return;
4195 
4196   assert(labels.is_nonempty(), "must be");
4197   assert((uint) labels.length() == n->outcnt(), "must be equal: %d == %d", labels.length(), n->outcnt());
4198 
4199   // Since MachConstantNode::constant_offset() also contains
4200   // table_base_offset() we need to subtract the table_base_offset()
4201   // to get the plain offset into the constant table.
4202   int offset = n->constant_offset() - table_base_offset();
4203 
4204   MacroAssembler _masm(&cb);
4205   address* jump_table_base = (address*) (_masm.code()->consts()->start() + offset);
4206 
4207   for (uint i = 0; i < n->outcnt(); i++) {
4208     address* constant_addr = &jump_table_base[i];
4209     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));
4210     *constant_addr = cb.consts()->target(*labels.at(i), (address) constant_addr);
4211     cb.consts()->relocate((address) constant_addr, relocInfo::internal_word_type);
4212   }
4213 }
4214 
4215 //----------------------------static_subtype_check-----------------------------
4216 // Shortcut important common cases when superklass is exact:
4217 // (0) superklass is java.lang.Object (can occur in reflective code)
4218 // (1) subklass is already limited to a subtype of superklass => always ok
4219 // (2) subklass does not overlap with superklass => always fail
4220 // (3) superklass has NO subtypes and we can check with a simple compare.
4221 int Compile::static_subtype_check(ciKlass* superk, ciKlass* subk) {
4222   if (StressReflectiveCode || superk == NULL || subk == NULL) {
4223     return SSC_full_test;       // Let caller generate the general case.
4224   }
4225 
4226   if (superk == env()->Object_klass()) {
4227     return SSC_always_true;     // (0) this test cannot fail
4228   }
4229 
4230   ciType* superelem = superk;
4231   if (superelem->is_array_klass())
4232     superelem = superelem->as_array_klass()->base_element_type();
4233 
4234   if (!subk->is_interface()) {  // cannot trust static interface types yet
4235     if (subk->is_subtype_of(superk)) {
4236       return SSC_always_true;   // (1) false path dead; no dynamic test needed
4237     }
4238     if (!(superelem->is_klass() && superelem->as_klass()->is_interface()) &&
4239         !superk->is_subtype_of(subk)) {
4240       return SSC_always_false;
4241     }
4242   }
4243 
4244   // If casting to an instance klass, it must have no subtypes
4245   if (superk->is_interface()) {
4246     // Cannot trust interfaces yet.
4247     // %%% S.B. superk->nof_implementors() == 1
4248   } else if (superelem->is_instance_klass()) {
4249     ciInstanceKlass* ik = superelem->as_instance_klass();
4250     if (!ik->has_subklass() && !ik->is_interface()) {
4251       if (!ik->is_final()) {
4252         // Add a dependency if there is a chance of a later subclass.
4253         dependencies()->assert_leaf_type(ik);
4254       }
4255       return SSC_easy_test;     // (3) caller can do a simple ptr comparison
4256     }
4257   } else {
4258     // A primitive array type has no subtypes.
4259     return SSC_easy_test;       // (3) caller can do a simple ptr comparison
4260   }
4261 
4262   return SSC_full_test;
4263 }
4264 
4265 Node* Compile::conv_I2X_index(PhaseGVN* phase, Node* idx, const TypeInt* sizetype, Node* ctrl) {
4266 #ifdef _LP64
4267   // The scaled index operand to AddP must be a clean 64-bit value.
4268   // Java allows a 32-bit int to be incremented to a negative
4269   // value, which appears in a 64-bit register as a large
4270   // positive number.  Using that large positive number as an
4271   // operand in pointer arithmetic has bad consequences.
4272   // On the other hand, 32-bit overflow is rare, and the possibility
4273   // can often be excluded, if we annotate the ConvI2L node with
4274   // a type assertion that its value is known to be a small positive
4275   // number.  (The prior range check has ensured this.)
4276   // This assertion is used by ConvI2LNode::Ideal.
4277   int index_max = max_jint - 1;  // array size is max_jint, index is one less
4278   if (sizetype != NULL) index_max = sizetype->_hi - 1;
4279   const TypeInt* iidxtype = TypeInt::make(0, index_max, Type::WidenMax);
4280   idx = constrained_convI2L(phase, idx, iidxtype, ctrl);
4281 #endif
4282   return idx;
4283 }
4284 
4285 // Convert integer value to a narrowed long type dependent on ctrl (for example, a range check)
4286 Node* Compile::constrained_convI2L(PhaseGVN* phase, Node* value, const TypeInt* itype, Node* ctrl) {
4287   if (ctrl != NULL) {
4288     // Express control dependency by a CastII node with a narrow type.
4289     value = new CastIINode(value, itype, false, true /* range check dependency */);
4290     // Make the CastII node dependent on the control input to prevent the narrowed ConvI2L
4291     // node from floating above the range check during loop optimizations. Otherwise, the
4292     // ConvI2L node may be eliminated independently of the range check, causing the data path
4293     // to become TOP while the control path is still there (although it's unreachable).
4294     value->set_req(0, ctrl);
4295     // Save CastII node to remove it after loop optimizations.
4296     phase->C->add_range_check_cast(value);
4297     value = phase->transform(value);
4298   }
4299   const TypeLong* ltype = TypeLong::make(itype->_lo, itype->_hi, itype->_widen);
4300   return phase->transform(new ConvI2LNode(value, ltype));
4301 }
4302 
4303 // The message about the current inlining is accumulated in
4304 // _print_inlining_stream and transfered into the _print_inlining_list
4305 // once we know whether inlining succeeds or not. For regular
4306 // inlining, messages are appended to the buffer pointed by
4307 // _print_inlining_idx in the _print_inlining_list. For late inlining,
4308 // a new buffer is added after _print_inlining_idx in the list. This
4309 // way we can update the inlining message for late inlining call site
4310 // when the inlining is attempted again.
4311 void Compile::print_inlining_init() {
4312   if (print_inlining() || print_intrinsics()) {
4313     _print_inlining_stream = new stringStream();
4314     _print_inlining_list = new (comp_arena())GrowableArray<PrintInliningBuffer>(comp_arena(), 1, 1, PrintInliningBuffer());
4315   }
4316 }
4317 
4318 void Compile::print_inlining_reinit() {
4319   if (print_inlining() || print_intrinsics()) {
4320     // Re allocate buffer when we change ResourceMark
4321     _print_inlining_stream = new stringStream();
4322   }
4323 }
4324 
4325 void Compile::print_inlining_reset() {
4326   _print_inlining_stream->reset();
4327 }
4328 
4329 void Compile::print_inlining_commit() {
4330   assert(print_inlining() || print_intrinsics(), "PrintInlining off?");
4331   // Transfer the message from _print_inlining_stream to the current
4332   // _print_inlining_list buffer and clear _print_inlining_stream.
4333   _print_inlining_list->at(_print_inlining_idx).ss()->write(_print_inlining_stream->as_string(), _print_inlining_stream->size());
4334   print_inlining_reset();
4335 }
4336 
4337 void Compile::print_inlining_push() {
4338   // Add new buffer to the _print_inlining_list at current position
4339   _print_inlining_idx++;
4340   _print_inlining_list->insert_before(_print_inlining_idx, PrintInliningBuffer());
4341 }
4342 
4343 Compile::PrintInliningBuffer& Compile::print_inlining_current() {
4344   return _print_inlining_list->at(_print_inlining_idx);
4345 }
4346 
4347 void Compile::print_inlining_update(CallGenerator* cg) {
4348   if (print_inlining() || print_intrinsics()) {
4349     if (!cg->is_late_inline()) {
4350       if (print_inlining_current().cg() != NULL) {
4351         print_inlining_push();
4352       }
4353       print_inlining_commit();
4354     } else {
4355       if (print_inlining_current().cg() != cg &&
4356           (print_inlining_current().cg() != NULL ||
4357            print_inlining_current().ss()->size() != 0)) {
4358         print_inlining_push();
4359       }
4360       print_inlining_commit();
4361       print_inlining_current().set_cg(cg);
4362     }
4363   }
4364 }
4365 
4366 void Compile::print_inlining_move_to(CallGenerator* cg) {
4367   // We resume inlining at a late inlining call site. Locate the
4368   // corresponding inlining buffer so that we can update it.
4369   if (print_inlining()) {
4370     for (int i = 0; i < _print_inlining_list->length(); i++) {
4371       if (_print_inlining_list->adr_at(i)->cg() == cg) {
4372         _print_inlining_idx = i;
4373         return;
4374       }
4375     }
4376     ShouldNotReachHere();
4377   }
4378 }
4379 
4380 void Compile::print_inlining_update_delayed(CallGenerator* cg) {
4381   if (print_inlining()) {
4382     assert(_print_inlining_stream->size() > 0, "missing inlining msg");
4383     assert(print_inlining_current().cg() == cg, "wrong entry");
4384     // replace message with new message
4385     _print_inlining_list->at_put(_print_inlining_idx, PrintInliningBuffer());
4386     print_inlining_commit();
4387     print_inlining_current().set_cg(cg);
4388   }
4389 }
4390 
4391 void Compile::print_inlining_assert_ready() {
4392   assert(!_print_inlining || _print_inlining_stream->size() == 0, "loosing data");
4393 }
4394 
4395 void Compile::process_print_inlining() {
4396   bool do_print_inlining = print_inlining() || print_intrinsics();
4397   if (do_print_inlining || log() != NULL) {
4398     // Print inlining message for candidates that we couldn't inline
4399     // for lack of space
4400     for (int i = 0; i < _late_inlines.length(); i++) {
4401       CallGenerator* cg = _late_inlines.at(i);
4402       if (!cg->is_mh_late_inline()) {
4403         const char* msg = "live nodes > LiveNodeCountInliningCutoff";
4404         if (do_print_inlining) {
4405           cg->print_inlining_late(msg);
4406         }
4407         log_late_inline_failure(cg, msg);
4408       }
4409     }
4410   }
4411   if (do_print_inlining) {
4412     ResourceMark rm;
4413     stringStream ss;
4414     for (int i = 0; i < _print_inlining_list->length(); i++) {
4415       ss.print("%s", _print_inlining_list->adr_at(i)->ss()->as_string());
4416     }
4417     size_t end = ss.size();
4418     _print_inlining_output = NEW_ARENA_ARRAY(comp_arena(), char, end+1);
4419     strncpy(_print_inlining_output, ss.base(), end+1);
4420     _print_inlining_output[end] = 0;
4421   }
4422 }
4423 
4424 void Compile::dump_print_inlining() {
4425   if (_print_inlining_output != NULL) {
4426     tty->print_raw(_print_inlining_output);
4427   }
4428 }
4429 
4430 void Compile::log_late_inline(CallGenerator* cg) {
4431   if (log() != NULL) {
4432     log()->head("late_inline method='%d'  inline_id='" JLONG_FORMAT "'", log()->identify(cg->method()),
4433                 cg->unique_id());
4434     JVMState* p = cg->call_node()->jvms();
4435     while (p != NULL) {
4436       log()->elem("jvms bci='%d' method='%d'", p->bci(), log()->identify(p->method()));
4437       p = p->caller();
4438     }
4439     log()->tail("late_inline");
4440   }
4441 }
4442 
4443 void Compile::log_late_inline_failure(CallGenerator* cg, const char* msg) {
4444   log_late_inline(cg);
4445   if (log() != NULL) {
4446     log()->inline_fail(msg);
4447   }
4448 }
4449 
4450 void Compile::log_inline_id(CallGenerator* cg) {
4451   if (log() != NULL) {
4452     // The LogCompilation tool needs a unique way to identify late
4453     // inline call sites. This id must be unique for this call site in
4454     // this compilation. Try to have it unique across compilations as
4455     // well because it can be convenient when grepping through the log
4456     // file.
4457     // Distinguish OSR compilations from others in case CICountOSR is
4458     // on.
4459     jlong id = ((jlong)unique()) + (((jlong)compile_id()) << 33) + (CICountOSR && is_osr_compilation() ? ((jlong)1) << 32 : 0);
4460     cg->set_unique_id(id);
4461     log()->elem("inline_id id='" JLONG_FORMAT "'", id);
4462   }
4463 }
4464 
4465 void Compile::log_inline_failure(const char* msg) {
4466   if (C->log() != NULL) {
4467     C->log()->inline_fail(msg);
4468   }
4469 }
4470 
4471 
4472 // Dump inlining replay data to the stream.
4473 // Don't change thread state and acquire any locks.
4474 void Compile::dump_inline_data(outputStream* out) {
4475   InlineTree* inl_tree = ilt();
4476   if (inl_tree != NULL) {
4477     out->print(" inline %d", inl_tree->count());
4478     inl_tree->dump_replay_data(out);
4479   }
4480 }
4481 
4482 int Compile::cmp_expensive_nodes(Node* n1, Node* n2) {
4483   if (n1->Opcode() < n2->Opcode())      return -1;
4484   else if (n1->Opcode() > n2->Opcode()) return 1;
4485 
4486   assert(n1->req() == n2->req(), "can't compare %s nodes: n1->req() = %d, n2->req() = %d", NodeClassNames[n1->Opcode()], n1->req(), n2->req());
4487   for (uint i = 1; i < n1->req(); i++) {
4488     if (n1->in(i) < n2->in(i))      return -1;
4489     else if (n1->in(i) > n2->in(i)) return 1;
4490   }
4491 
4492   return 0;
4493 }
4494 
4495 int Compile::cmp_expensive_nodes(Node** n1p, Node** n2p) {
4496   Node* n1 = *n1p;
4497   Node* n2 = *n2p;
4498 
4499   return cmp_expensive_nodes(n1, n2);
4500 }
4501 
4502 void Compile::sort_expensive_nodes() {
4503   if (!expensive_nodes_sorted()) {
4504     _expensive_nodes->sort(cmp_expensive_nodes);
4505   }
4506 }
4507 
4508 bool Compile::expensive_nodes_sorted() const {
4509   for (int i = 1; i < _expensive_nodes->length(); i++) {
4510     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i-1)) < 0) {
4511       return false;
4512     }
4513   }
4514   return true;
4515 }
4516 
4517 bool Compile::should_optimize_expensive_nodes(PhaseIterGVN &igvn) {
4518   if (_expensive_nodes->length() == 0) {
4519     return false;
4520   }
4521 
4522   assert(OptimizeExpensiveOps, "optimization off?");
4523 
4524   // Take this opportunity to remove dead nodes from the list
4525   int j = 0;
4526   for (int i = 0; i < _expensive_nodes->length(); i++) {
4527     Node* n = _expensive_nodes->at(i);
4528     if (!n->is_unreachable(igvn)) {
4529       assert(n->is_expensive(), "should be expensive");
4530       _expensive_nodes->at_put(j, n);
4531       j++;
4532     }
4533   }
4534   _expensive_nodes->trunc_to(j);
4535 
4536   // Then sort the list so that similar nodes are next to each other
4537   // and check for at least two nodes of identical kind with same data
4538   // inputs.
4539   sort_expensive_nodes();
4540 
4541   for (int i = 0; i < _expensive_nodes->length()-1; i++) {
4542     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i+1)) == 0) {
4543       return true;
4544     }
4545   }
4546 
4547   return false;
4548 }
4549 
4550 void Compile::cleanup_expensive_nodes(PhaseIterGVN &igvn) {
4551   if (_expensive_nodes->length() == 0) {
4552     return;
4553   }
4554 
4555   assert(OptimizeExpensiveOps, "optimization off?");
4556 
4557   // Sort to bring similar nodes next to each other and clear the
4558   // control input of nodes for which there's only a single copy.
4559   sort_expensive_nodes();
4560 
4561   int j = 0;
4562   int identical = 0;
4563   int i = 0;
4564   bool modified = false;
4565   for (; i < _expensive_nodes->length()-1; i++) {
4566     assert(j <= i, "can't write beyond current index");
4567     if (_expensive_nodes->at(i)->Opcode() == _expensive_nodes->at(i+1)->Opcode()) {
4568       identical++;
4569       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4570       continue;
4571     }
4572     if (identical > 0) {
4573       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4574       identical = 0;
4575     } else {
4576       Node* n = _expensive_nodes->at(i);
4577       igvn.replace_input_of(n, 0, NULL);
4578       igvn.hash_insert(n);
4579       modified = true;
4580     }
4581   }
4582   if (identical > 0) {
4583     _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4584   } else if (_expensive_nodes->length() >= 1) {
4585     Node* n = _expensive_nodes->at(i);
4586     igvn.replace_input_of(n, 0, NULL);
4587     igvn.hash_insert(n);
4588     modified = true;
4589   }
4590   _expensive_nodes->trunc_to(j);
4591   if (modified) {
4592     igvn.optimize();
4593   }
4594 }
4595 
4596 void Compile::add_expensive_node(Node * n) {
4597   assert(!_expensive_nodes->contains(n), "duplicate entry in expensive list");
4598   assert(n->is_expensive(), "expensive nodes with non-null control here only");
4599   assert(!n->is_CFG() && !n->is_Mem(), "no cfg or memory nodes here");
4600   if (OptimizeExpensiveOps) {
4601     _expensive_nodes->append(n);
4602   } else {
4603     // Clear control input and let IGVN optimize expensive nodes if
4604     // OptimizeExpensiveOps is off.
4605     n->set_req(0, NULL);
4606   }
4607 }
4608 
4609 /**
4610  * Remove the speculative part of types and clean up the graph
4611  */
4612 void Compile::remove_speculative_types(PhaseIterGVN &igvn) {
4613   if (UseTypeSpeculation) {
4614     Unique_Node_List worklist;
4615     worklist.push(root());
4616     int modified = 0;
4617     // Go over all type nodes that carry a speculative type, drop the
4618     // speculative part of the type and enqueue the node for an igvn
4619     // which may optimize it out.
4620     for (uint next = 0; next < worklist.size(); ++next) {
4621       Node *n  = worklist.at(next);
4622       if (n->is_Type()) {
4623         TypeNode* tn = n->as_Type();
4624         const Type* t = tn->type();
4625         const Type* t_no_spec = t->remove_speculative();
4626         if (t_no_spec != t) {
4627           bool in_hash = igvn.hash_delete(n);
4628           assert(in_hash, "node should be in igvn hash table");
4629           tn->set_type(t_no_spec);
4630           igvn.hash_insert(n);
4631           igvn._worklist.push(n); // give it a chance to go away
4632           modified++;
4633         }
4634       }
4635       uint max = n->len();
4636       for( uint i = 0; i < max; ++i ) {
4637         Node *m = n->in(i);
4638         if (not_a_node(m))  continue;
4639         worklist.push(m);
4640       }
4641     }
4642     // Drop the speculative part of all types in the igvn's type table
4643     igvn.remove_speculative_types();
4644     if (modified > 0) {
4645       igvn.optimize();
4646     }
4647 #ifdef ASSERT
4648     // Verify that after the IGVN is over no speculative type has resurfaced
4649     worklist.clear();
4650     worklist.push(root());
4651     for (uint next = 0; next < worklist.size(); ++next) {
4652       Node *n  = worklist.at(next);
4653       const Type* t = igvn.type_or_null(n);
4654       assert((t == NULL) || (t == t->remove_speculative()), "no more speculative types");
4655       if (n->is_Type()) {
4656         t = n->as_Type()->type();
4657         assert(t == t->remove_speculative(), "no more speculative types");
4658       }
4659       uint max = n->len();
4660       for( uint i = 0; i < max; ++i ) {
4661         Node *m = n->in(i);
4662         if (not_a_node(m))  continue;
4663         worklist.push(m);
4664       }
4665     }
4666     igvn.check_no_speculative_types();
4667 #endif
4668   }
4669 }
4670 
4671 Node* Compile::optimize_acmp(PhaseGVN* phase, Node* a, Node* b) {
4672   const TypeInstPtr* ta = phase->type(a)->isa_instptr();
4673   const TypeInstPtr* tb = phase->type(b)->isa_instptr();
4674   if (!EnableValhalla || ta == NULL || tb == NULL ||
4675       ta->is_zero_type() || tb->is_zero_type() ||
4676       !ta->can_be_value_type() || !tb->can_be_value_type()) {
4677     // Use old acmp if one operand is null or not a value type
4678     return new CmpPNode(a, b);
4679   } else if (ta->is_valuetypeptr() || tb->is_valuetypeptr()) {
4680     // We know that one operand is a value type. Therefore,
4681     // new acmp will only return true if both operands are NULL.
4682     // Check if both operands are null by or'ing the oops.
4683     a = phase->transform(new CastP2XNode(NULL, a));
4684     b = phase->transform(new CastP2XNode(NULL, b));
4685     a = phase->transform(new OrXNode(a, b));
4686     return new CmpXNode(a, phase->MakeConX(0));
4687   }
4688   // Use new acmp
4689   return NULL;
4690 }
4691 
4692 // Auxiliary method to support randomized stressing/fuzzing.
4693 //
4694 // This method can be called the arbitrary number of times, with current count
4695 // as the argument. The logic allows selecting a single candidate from the
4696 // running list of candidates as follows:
4697 //    int count = 0;
4698 //    Cand* selected = null;
4699 //    while(cand = cand->next()) {
4700 //      if (randomized_select(++count)) {
4701 //        selected = cand;
4702 //      }
4703 //    }
4704 //
4705 // Including count equalizes the chances any candidate is "selected".
4706 // This is useful when we don't have the complete list of candidates to choose
4707 // from uniformly. In this case, we need to adjust the randomicity of the
4708 // selection, or else we will end up biasing the selection towards the latter
4709 // candidates.
4710 //
4711 // Quick back-envelope calculation shows that for the list of n candidates
4712 // the equal probability for the candidate to persist as "best" can be
4713 // achieved by replacing it with "next" k-th candidate with the probability
4714 // of 1/k. It can be easily shown that by the end of the run, the
4715 // probability for any candidate is converged to 1/n, thus giving the
4716 // uniform distribution among all the candidates.
4717 //
4718 // We don't care about the domain size as long as (RANDOMIZED_DOMAIN / count) is large.
4719 #define RANDOMIZED_DOMAIN_POW 29
4720 #define RANDOMIZED_DOMAIN (1 << RANDOMIZED_DOMAIN_POW)
4721 #define RANDOMIZED_DOMAIN_MASK ((1 << (RANDOMIZED_DOMAIN_POW + 1)) - 1)
4722 bool Compile::randomized_select(int count) {
4723   assert(count > 0, "only positive");
4724   return (os::random() & RANDOMIZED_DOMAIN_MASK) < (RANDOMIZED_DOMAIN / count);
4725 }
4726 
4727 CloneMap&     Compile::clone_map()                 { return _clone_map; }
4728 void          Compile::set_clone_map(Dict* d)      { _clone_map._dict = d; }
4729 
4730 void NodeCloneInfo::dump() const {
4731   tty->print(" {%d:%d} ", idx(), gen());
4732 }
4733 
4734 void CloneMap::clone(Node* old, Node* nnn, int gen) {
4735   uint64_t val = value(old->_idx);
4736   NodeCloneInfo cio(val);
4737   assert(val != 0, "old node should be in the map");
4738   NodeCloneInfo cin(cio.idx(), gen + cio.gen());
4739   insert(nnn->_idx, cin.get());
4740 #ifndef PRODUCT
4741   if (is_debug()) {
4742     tty->print_cr("CloneMap::clone inserted node %d info {%d:%d} into CloneMap", nnn->_idx, cin.idx(), cin.gen());
4743   }
4744 #endif
4745 }
4746 
4747 void CloneMap::verify_insert_and_clone(Node* old, Node* nnn, int gen) {
4748   NodeCloneInfo cio(value(old->_idx));
4749   if (cio.get() == 0) {
4750     cio.set(old->_idx, 0);
4751     insert(old->_idx, cio.get());
4752 #ifndef PRODUCT
4753     if (is_debug()) {
4754       tty->print_cr("CloneMap::verify_insert_and_clone inserted node %d info {%d:%d} into CloneMap", old->_idx, cio.idx(), cio.gen());
4755     }
4756 #endif
4757   }
4758   clone(old, nnn, gen);
4759 }
4760 
4761 int CloneMap::max_gen() const {
4762   int g = 0;
4763   DictI di(_dict);
4764   for(; di.test(); ++di) {
4765     int t = gen(di._key);
4766     if (g < t) {
4767       g = t;
4768 #ifndef PRODUCT
4769       if (is_debug()) {
4770         tty->print_cr("CloneMap::max_gen() update max=%d from %d", g, _2_node_idx_t(di._key));
4771       }
4772 #endif
4773     }
4774   }
4775   return g;
4776 }
4777 
4778 void CloneMap::dump(node_idx_t key) const {
4779   uint64_t val = value(key);
4780   if (val != 0) {
4781     NodeCloneInfo ni(val);
4782     ni.dump();
4783   }
4784 }