1 /*
   2  * Copyright (c) 1997, 2020, 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/javaClasses.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 "jfr/jfrEvents.hpp"
  39 #include "memory/resourceArea.hpp"
  40 #include "opto/addnode.hpp"
  41 #include "opto/block.hpp"
  42 #include "opto/c2compiler.hpp"
  43 #include "opto/callGenerator.hpp"
  44 #include "opto/callnode.hpp"
  45 #include "opto/castnode.hpp"
  46 #include "opto/cfgnode.hpp"
  47 #include "opto/chaitin.hpp"
  48 #include "opto/compile.hpp"
  49 #include "opto/connode.hpp"
  50 #include "opto/convertnode.hpp"
  51 #include "opto/divnode.hpp"
  52 #include "opto/escape.hpp"
  53 #include "opto/idealGraphPrinter.hpp"
  54 #include "opto/inlinetypenode.hpp"
  55 #include "opto/loopnode.hpp"
  56 #include "opto/machnode.hpp"
  57 #include "opto/macro.hpp"
  58 #include "opto/matcher.hpp"
  59 #include "opto/mathexactnode.hpp"
  60 #include "opto/memnode.hpp"
  61 #include "opto/mulnode.hpp"
  62 #include "opto/narrowptrnode.hpp"
  63 #include "opto/node.hpp"
  64 #include "opto/opcodes.hpp"
  65 #include "opto/output.hpp"
  66 #include "opto/parse.hpp"
  67 #include "opto/phaseX.hpp"
  68 #include "opto/rootnode.hpp"
  69 #include "opto/runtime.hpp"
  70 #include "opto/stringopts.hpp"
  71 #include "opto/type.hpp"
  72 #include "opto/vectornode.hpp"
  73 #include "runtime/arguments.hpp"
  74 #include "runtime/sharedRuntime.hpp"
  75 #include "runtime/signature.hpp"
  76 #include "runtime/stubRoutines.hpp"
  77 #include "runtime/timer.hpp"
  78 #include "utilities/align.hpp"
  79 #include "utilities/copy.hpp"
  80 #include "utilities/macros.hpp"
  81 #include "utilities/resourceHash.hpp"
  82 
  83 
  84 // -------------------- Compile::mach_constant_base_node -----------------------
  85 // Constant table base node singleton.
  86 MachConstantBaseNode* Compile::mach_constant_base_node() {
  87   if (_mach_constant_base_node == NULL) {
  88     _mach_constant_base_node = new MachConstantBaseNode();
  89     _mach_constant_base_node->add_req(C->root());
  90   }
  91   return _mach_constant_base_node;
  92 }
  93 
  94 
  95 /// Support for intrinsics.
  96 
  97 // Return the index at which m must be inserted (or already exists).
  98 // The sort order is by the address of the ciMethod, with is_virtual as minor key.
  99 class IntrinsicDescPair {
 100  private:
 101   ciMethod* _m;
 102   bool _is_virtual;
 103  public:
 104   IntrinsicDescPair(ciMethod* m, bool is_virtual) : _m(m), _is_virtual(is_virtual) {}
 105   static int compare(IntrinsicDescPair* const& key, CallGenerator* const& elt) {
 106     ciMethod* m= elt->method();
 107     ciMethod* key_m = key->_m;
 108     if (key_m < m)      return -1;
 109     else if (key_m > m) return 1;
 110     else {
 111       bool is_virtual = elt->is_virtual();
 112       bool key_virtual = key->_is_virtual;
 113       if (key_virtual < is_virtual)      return -1;
 114       else if (key_virtual > is_virtual) return 1;
 115       else                               return 0;
 116     }
 117   }
 118 };
 119 int Compile::intrinsic_insertion_index(ciMethod* m, bool is_virtual, bool& found) {
 120 #ifdef ASSERT
 121   for (int i = 1; i < _intrinsics->length(); i++) {
 122     CallGenerator* cg1 = _intrinsics->at(i-1);
 123     CallGenerator* cg2 = _intrinsics->at(i);
 124     assert(cg1->method() != cg2->method()
 125            ? cg1->method()     < cg2->method()
 126            : cg1->is_virtual() < cg2->is_virtual(),
 127            "compiler intrinsics list must stay sorted");
 128   }
 129 #endif
 130   IntrinsicDescPair pair(m, is_virtual);
 131   return _intrinsics->find_sorted<IntrinsicDescPair*, IntrinsicDescPair::compare>(&pair, found);
 132 }
 133 
 134 void Compile::register_intrinsic(CallGenerator* cg) {
 135   if (_intrinsics == NULL) {
 136     _intrinsics = new (comp_arena())GrowableArray<CallGenerator*>(comp_arena(), 60, 0, NULL);
 137   }
 138   int len = _intrinsics->length();
 139   bool found = false;
 140   int index = intrinsic_insertion_index(cg->method(), cg->is_virtual(), found);
 141   assert(!found, "registering twice");
 142   _intrinsics->insert_before(index, cg);
 143   assert(find_intrinsic(cg->method(), cg->is_virtual()) == cg, "registration worked");
 144 }
 145 
 146 CallGenerator* Compile::find_intrinsic(ciMethod* m, bool is_virtual) {
 147   assert(m->is_loaded(), "don't try this on unloaded methods");
 148   if (_intrinsics != NULL) {
 149     bool found = false;
 150     int index = intrinsic_insertion_index(m, is_virtual, found);
 151      if (found) {
 152       return _intrinsics->at(index);
 153     }
 154   }
 155   // Lazily create intrinsics for intrinsic IDs well-known in the runtime.
 156   if (m->intrinsic_id() != vmIntrinsics::_none &&
 157       m->intrinsic_id() <= vmIntrinsics::LAST_COMPILER_INLINE) {
 158     CallGenerator* cg = make_vm_intrinsic(m, is_virtual);
 159     if (cg != NULL) {
 160       // Save it for next time:
 161       register_intrinsic(cg);
 162       return cg;
 163     } else {
 164       gather_intrinsic_statistics(m->intrinsic_id(), is_virtual, _intrinsic_disabled);
 165     }
 166   }
 167   return NULL;
 168 }
 169 
 170 // Compile:: register_library_intrinsics and make_vm_intrinsic are defined
 171 // in library_call.cpp.
 172 
 173 
 174 #ifndef PRODUCT
 175 // statistics gathering...
 176 
 177 juint  Compile::_intrinsic_hist_count[vmIntrinsics::ID_LIMIT] = {0};
 178 jubyte Compile::_intrinsic_hist_flags[vmIntrinsics::ID_LIMIT] = {0};
 179 
 180 bool Compile::gather_intrinsic_statistics(vmIntrinsics::ID id, bool is_virtual, int flags) {
 181   assert(id > vmIntrinsics::_none && id < vmIntrinsics::ID_LIMIT, "oob");
 182   int oflags = _intrinsic_hist_flags[id];
 183   assert(flags != 0, "what happened?");
 184   if (is_virtual) {
 185     flags |= _intrinsic_virtual;
 186   }
 187   bool changed = (flags != oflags);
 188   if ((flags & _intrinsic_worked) != 0) {
 189     juint count = (_intrinsic_hist_count[id] += 1);
 190     if (count == 1) {
 191       changed = true;           // first time
 192     }
 193     // increment the overall count also:
 194     _intrinsic_hist_count[vmIntrinsics::_none] += 1;
 195   }
 196   if (changed) {
 197     if (((oflags ^ flags) & _intrinsic_virtual) != 0) {
 198       // Something changed about the intrinsic's virtuality.
 199       if ((flags & _intrinsic_virtual) != 0) {
 200         // This is the first use of this intrinsic as a virtual call.
 201         if (oflags != 0) {
 202           // We already saw it as a non-virtual, so note both cases.
 203           flags |= _intrinsic_both;
 204         }
 205       } else if ((oflags & _intrinsic_both) == 0) {
 206         // This is the first use of this intrinsic as a non-virtual
 207         flags |= _intrinsic_both;
 208       }
 209     }
 210     _intrinsic_hist_flags[id] = (jubyte) (oflags | flags);
 211   }
 212   // update the overall flags also:
 213   _intrinsic_hist_flags[vmIntrinsics::_none] |= (jubyte) flags;
 214   return changed;
 215 }
 216 
 217 static char* format_flags(int flags, char* buf) {
 218   buf[0] = 0;
 219   if ((flags & Compile::_intrinsic_worked) != 0)    strcat(buf, ",worked");
 220   if ((flags & Compile::_intrinsic_failed) != 0)    strcat(buf, ",failed");
 221   if ((flags & Compile::_intrinsic_disabled) != 0)  strcat(buf, ",disabled");
 222   if ((flags & Compile::_intrinsic_virtual) != 0)   strcat(buf, ",virtual");
 223   if ((flags & Compile::_intrinsic_both) != 0)      strcat(buf, ",nonvirtual");
 224   if (buf[0] == 0)  strcat(buf, ",");
 225   assert(buf[0] == ',', "must be");
 226   return &buf[1];
 227 }
 228 
 229 void Compile::print_intrinsic_statistics() {
 230   char flagsbuf[100];
 231   ttyLocker ttyl;
 232   if (xtty != NULL)  xtty->head("statistics type='intrinsic'");
 233   tty->print_cr("Compiler intrinsic usage:");
 234   juint total = _intrinsic_hist_count[vmIntrinsics::_none];
 235   if (total == 0)  total = 1;  // avoid div0 in case of no successes
 236   #define PRINT_STAT_LINE(name, c, f) \
 237     tty->print_cr("  %4d (%4.1f%%) %s (%s)", (int)(c), ((c) * 100.0) / total, name, f);
 238   for (int index = 1 + (int)vmIntrinsics::_none; index < (int)vmIntrinsics::ID_LIMIT; index++) {
 239     vmIntrinsics::ID id = (vmIntrinsics::ID) index;
 240     int   flags = _intrinsic_hist_flags[id];
 241     juint count = _intrinsic_hist_count[id];
 242     if ((flags | count) != 0) {
 243       PRINT_STAT_LINE(vmIntrinsics::name_at(id), count, format_flags(flags, flagsbuf));
 244     }
 245   }
 246   PRINT_STAT_LINE("total", total, format_flags(_intrinsic_hist_flags[vmIntrinsics::_none], flagsbuf));
 247   if (xtty != NULL)  xtty->tail("statistics");
 248 }
 249 
 250 void Compile::print_statistics() {
 251   { ttyLocker ttyl;
 252     if (xtty != NULL)  xtty->head("statistics type='opto'");
 253     Parse::print_statistics();
 254     PhaseCCP::print_statistics();
 255     PhaseRegAlloc::print_statistics();
 256     PhaseOutput::print_statistics();
 257     PhasePeephole::print_statistics();
 258     PhaseIdealLoop::print_statistics();
 259     if (xtty != NULL)  xtty->tail("statistics");
 260   }
 261   if (_intrinsic_hist_flags[vmIntrinsics::_none] != 0) {
 262     // put this under its own <statistics> element.
 263     print_intrinsic_statistics();
 264   }
 265 }
 266 #endif //PRODUCT
 267 
 268 void Compile::gvn_replace_by(Node* n, Node* nn) {
 269   for (DUIterator_Last imin, i = n->last_outs(imin); i >= imin; ) {
 270     Node* use = n->last_out(i);
 271     bool is_in_table = initial_gvn()->hash_delete(use);
 272     uint uses_found = 0;
 273     for (uint j = 0; j < use->len(); j++) {
 274       if (use->in(j) == n) {
 275         if (j < use->req())
 276           use->set_req(j, nn);
 277         else
 278           use->set_prec(j, nn);
 279         uses_found++;
 280       }
 281     }
 282     if (is_in_table) {
 283       // reinsert into table
 284       initial_gvn()->hash_find_insert(use);
 285     }
 286     record_for_igvn(use);
 287     i -= uses_found;    // we deleted 1 or more copies of this edge
 288   }
 289 }
 290 
 291 
 292 static inline bool not_a_node(const Node* n) {
 293   if (n == NULL)                   return true;
 294   if (((intptr_t)n & 1) != 0)      return true;  // uninitialized, etc.
 295   if (*(address*)n == badAddress)  return true;  // kill by Node::destruct
 296   return false;
 297 }
 298 
 299 // Identify all nodes that are reachable from below, useful.
 300 // Use breadth-first pass that records state in a Unique_Node_List,
 301 // recursive traversal is slower.
 302 void Compile::identify_useful_nodes(Unique_Node_List &useful) {
 303   int estimated_worklist_size = live_nodes();
 304   useful.map( estimated_worklist_size, NULL );  // preallocate space
 305 
 306   // Initialize worklist
 307   if (root() != NULL)     { useful.push(root()); }
 308   // If 'top' is cached, declare it useful to preserve cached node
 309   if( cached_top_node() ) { useful.push(cached_top_node()); }
 310 
 311   // Push all useful nodes onto the list, breadthfirst
 312   for( uint next = 0; next < useful.size(); ++next ) {
 313     assert( next < unique(), "Unique useful nodes < total nodes");
 314     Node *n  = useful.at(next);
 315     uint max = n->len();
 316     for( uint i = 0; i < max; ++i ) {
 317       Node *m = n->in(i);
 318       if (not_a_node(m))  continue;
 319       useful.push(m);
 320     }
 321   }
 322 }
 323 
 324 // Update dead_node_list with any missing dead nodes using useful
 325 // list. Consider all non-useful nodes to be useless i.e., dead nodes.
 326 void Compile::update_dead_node_list(Unique_Node_List &useful) {
 327   uint max_idx = unique();
 328   VectorSet& useful_node_set = useful.member_set();
 329 
 330   for (uint node_idx = 0; node_idx < max_idx; node_idx++) {
 331     // If node with index node_idx is not in useful set,
 332     // mark it as dead in dead node list.
 333     if (!useful_node_set.test(node_idx)) {
 334       record_dead_node(node_idx);
 335     }
 336   }
 337 }
 338 
 339 void Compile::remove_useless_late_inlines(GrowableArray<CallGenerator*>* inlines, Unique_Node_List &useful) {
 340   int shift = 0;
 341   for (int i = 0; i < inlines->length(); i++) {
 342     CallGenerator* cg = inlines->at(i);
 343     CallNode* call = cg->call_node();
 344     if (shift > 0) {
 345       inlines->at_put(i-shift, cg);
 346     }
 347     if (!useful.member(call)) {
 348       shift++;
 349     }
 350   }
 351   inlines->trunc_to(inlines->length()-shift);
 352 }
 353 
 354 // Disconnect all useless nodes by disconnecting those at the boundary.
 355 void Compile::remove_useless_nodes(Unique_Node_List &useful) {
 356   uint next = 0;
 357   while (next < useful.size()) {
 358     Node *n = useful.at(next++);
 359     if (n->is_SafePoint()) {
 360       // We're done with a parsing phase. Replaced nodes are not valid
 361       // beyond that point.
 362       n->as_SafePoint()->delete_replaced_nodes();
 363     }
 364     // Use raw traversal of out edges since this code removes out edges
 365     int max = n->outcnt();
 366     for (int j = 0; j < max; ++j) {
 367       Node* child = n->raw_out(j);
 368       if (! useful.member(child)) {
 369         assert(!child->is_top() || child != top(),
 370                "If top is cached in Compile object it is in useful list");
 371         // Only need to remove this out-edge to the useless node
 372         n->raw_del_out(j);
 373         --j;
 374         --max;
 375       }
 376     }
 377     if (n->outcnt() == 1 && n->has_special_unique_user()) {
 378       record_for_igvn(n->unique_out());
 379     }
 380   }
 381   // Remove useless macro and predicate opaq nodes
 382   for (int i = C->macro_count()-1; i >= 0; i--) {
 383     Node* n = C->macro_node(i);
 384     if (!useful.member(n)) {
 385       remove_macro_node(n);
 386     }
 387   }
 388   // Remove useless CastII nodes with range check dependency
 389   for (int i = range_check_cast_count() - 1; i >= 0; i--) {
 390     Node* cast = range_check_cast_node(i);
 391     if (!useful.member(cast)) {
 392       remove_range_check_cast(cast);
 393     }
 394   }
 395   // Remove useless expensive nodes
 396   for (int i = C->expensive_count()-1; i >= 0; i--) {
 397     Node* n = C->expensive_node(i);
 398     if (!useful.member(n)) {
 399       remove_expensive_node(n);
 400     }
 401   }
 402   // Remove useless Opaque4 nodes
 403   for (int i = opaque4_count() - 1; i >= 0; i--) {
 404     Node* opaq = opaque4_node(i);
 405     if (!useful.member(opaq)) {
 406       remove_opaque4_node(opaq);
 407     }
 408   }
 409   // Remove useless inline type nodes
 410   for (int i = _inline_type_nodes->length() - 1; i >= 0; i--) {
 411     Node* vt = _inline_type_nodes->at(i);
 412     if (!useful.member(vt)) {
 413       _inline_type_nodes->remove(vt);
 414     }
 415   }
 416   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 417   bs->eliminate_useless_gc_barriers(useful, this);
 418   // clean up the late inline lists
 419   remove_useless_late_inlines(&_string_late_inlines, useful);
 420   remove_useless_late_inlines(&_boxing_late_inlines, useful);
 421   remove_useless_late_inlines(&_late_inlines, useful);
 422   debug_only(verify_graph_edges(true/*check for no_dead_code*/);)
 423 }
 424 
 425 // ============================================================================
 426 //------------------------------CompileWrapper---------------------------------
 427 class CompileWrapper : public StackObj {
 428   Compile *const _compile;
 429  public:
 430   CompileWrapper(Compile* compile);
 431 
 432   ~CompileWrapper();
 433 };
 434 
 435 CompileWrapper::CompileWrapper(Compile* compile) : _compile(compile) {
 436   // the Compile* pointer is stored in the current ciEnv:
 437   ciEnv* env = compile->env();
 438   assert(env == ciEnv::current(), "must already be a ciEnv active");
 439   assert(env->compiler_data() == NULL, "compile already active?");
 440   env->set_compiler_data(compile);
 441   assert(compile == Compile::current(), "sanity");
 442 
 443   compile->set_type_dict(NULL);
 444   compile->set_clone_map(new Dict(cmpkey, hashkey, _compile->comp_arena()));
 445   compile->clone_map().set_clone_idx(0);
 446   compile->set_type_last_size(0);
 447   compile->set_last_tf(NULL, NULL);
 448   compile->set_indexSet_arena(NULL);
 449   compile->set_indexSet_free_block_list(NULL);
 450   compile->init_type_arena();
 451   Type::Initialize(compile);
 452   _compile->begin_method();
 453   _compile->clone_map().set_debug(_compile->has_method() && _compile->directive()->CloneMapDebugOption);
 454 }
 455 CompileWrapper::~CompileWrapper() {
 456   _compile->end_method();
 457   _compile->env()->set_compiler_data(NULL);
 458 }
 459 
 460 
 461 //----------------------------print_compile_messages---------------------------
 462 void Compile::print_compile_messages() {
 463 #ifndef PRODUCT
 464   // Check if recompiling
 465   if (_subsume_loads == false && PrintOpto) {
 466     // Recompiling without allowing machine instructions to subsume loads
 467     tty->print_cr("*********************************************************");
 468     tty->print_cr("** Bailout: Recompile without subsuming loads          **");
 469     tty->print_cr("*********************************************************");
 470   }
 471   if (_do_escape_analysis != DoEscapeAnalysis && PrintOpto) {
 472     // Recompiling without escape analysis
 473     tty->print_cr("*********************************************************");
 474     tty->print_cr("** Bailout: Recompile without escape analysis          **");
 475     tty->print_cr("*********************************************************");
 476   }
 477   if (_eliminate_boxing != EliminateAutoBox && PrintOpto) {
 478     // Recompiling without boxing elimination
 479     tty->print_cr("*********************************************************");
 480     tty->print_cr("** Bailout: Recompile without boxing elimination       **");
 481     tty->print_cr("*********************************************************");
 482   }
 483   if (C->directive()->BreakAtCompileOption) {
 484     // Open the debugger when compiling this method.
 485     tty->print("### Breaking when compiling: ");
 486     method()->print_short_name();
 487     tty->cr();
 488     BREAKPOINT;
 489   }
 490 
 491   if( PrintOpto ) {
 492     if (is_osr_compilation()) {
 493       tty->print("[OSR]%3d", _compile_id);
 494     } else {
 495       tty->print("%3d", _compile_id);
 496     }
 497   }
 498 #endif
 499 }
 500 
 501 // ============================================================================
 502 //------------------------------Compile standard-------------------------------
 503 debug_only( int Compile::_debug_idx = 100000; )
 504 
 505 // Compile a method.  entry_bci is -1 for normal compilations and indicates
 506 // the continuation bci for on stack replacement.
 507 
 508 
 509 Compile::Compile( ciEnv* ci_env, ciMethod* target, int osr_bci,
 510                   bool subsume_loads, bool do_escape_analysis, bool eliminate_boxing, bool install_code, DirectiveSet* directive)
 511                 : Phase(Compiler),
 512                   _compile_id(ci_env->compile_id()),
 513                   _save_argument_registers(false),
 514                   _subsume_loads(subsume_loads),
 515                   _do_escape_analysis(do_escape_analysis),
 516                   _install_code(install_code),
 517                   _eliminate_boxing(eliminate_boxing),
 518                   _method(target),
 519                   _entry_bci(osr_bci),
 520                   _stub_function(NULL),
 521                   _stub_name(NULL),
 522                   _stub_entry_point(NULL),
 523                   _max_node_limit(MaxNodeLimit),
 524                   _inlining_progress(false),
 525                   _inlining_incrementally(false),
 526                   _do_cleanup(false),
 527                   _has_reserved_stack_access(target->has_reserved_stack_access()),
 528 #ifndef PRODUCT
 529                   _trace_opto_output(directive->TraceOptoOutputOption),
 530                   _print_ideal(directive->PrintIdealOption),
 531 #endif
 532                   _has_method_handle_invokes(false),
 533                   _clinit_barrier_on_entry(false),
 534                   _comp_arena(mtCompiler),
 535                   _barrier_set_state(BarrierSet::barrier_set()->barrier_set_c2()->create_barrier_state(comp_arena())),
 536                   _env(ci_env),
 537                   _directive(directive),
 538                   _log(ci_env->log()),
 539                   _failure_reason(NULL),
 540                   _congraph(NULL),
 541                   NOT_PRODUCT(_printer(NULL) COMMA)
 542                   _dead_node_list(comp_arena()),
 543                   _dead_node_count(0),
 544                   _node_arena(mtCompiler),
 545                   _old_arena(mtCompiler),
 546                   _mach_constant_base_node(NULL),
 547                   _Compile_types(mtCompiler),
 548                   _initial_gvn(NULL),
 549                   _for_igvn(NULL),
 550                   _warm_calls(NULL),
 551                   _late_inlines(comp_arena(), 2, 0, NULL),
 552                   _string_late_inlines(comp_arena(), 2, 0, NULL),
 553                   _boxing_late_inlines(comp_arena(), 2, 0, NULL),
 554                   _late_inlines_pos(0),
 555                   _number_of_mh_late_inlines(0),
 556                   _print_inlining_stream(NULL),
 557                   _print_inlining_list(NULL),
 558                   _print_inlining_idx(0),
 559                   _print_inlining_output(NULL),
 560                   _replay_inline_data(NULL),
 561                   _java_calls(0),
 562                   _inner_loops(0),
 563                   _interpreter_frame_size(0)
 564 #ifndef PRODUCT
 565                   , _in_dump_cnt(0)
 566 #endif
 567 {
 568   C = this;
 569   CompileWrapper cw(this);
 570 
 571   if (CITimeVerbose) {
 572     tty->print(" ");
 573     target->holder()->name()->print();
 574     tty->print(".");
 575     target->print_short_name();
 576     tty->print("  ");
 577   }
 578   TraceTime t1("Total compilation time", &_t_totalCompilation, CITime, CITimeVerbose);
 579   TraceTime t2(NULL, &_t_methodCompilation, CITime, false);
 580 
 581 #if defined(SUPPORT_ASSEMBLY) || defined(SUPPORT_ABSTRACT_ASSEMBLY)
 582   bool print_opto_assembly = directive->PrintOptoAssemblyOption;
 583   // We can always print a disassembly, either abstract (hex dump) or
 584   // with the help of a suitable hsdis library. Thus, we should not
 585   // couple print_assembly and print_opto_assembly controls.
 586   // But: always print opto and regular assembly on compile command 'print'.
 587   bool print_assembly = directive->PrintAssemblyOption;
 588   set_print_assembly(print_opto_assembly || print_assembly);
 589 #else
 590   set_print_assembly(false); // must initialize.
 591 #endif
 592 
 593 #ifndef PRODUCT
 594   set_parsed_irreducible_loop(false);
 595 
 596   if (directive->ReplayInlineOption) {
 597     _replay_inline_data = ciReplay::load_inline_data(method(), entry_bci(), ci_env->comp_level());
 598   }
 599 #endif
 600   set_print_inlining(directive->PrintInliningOption || PrintOptoInlining);
 601   set_print_intrinsics(directive->PrintIntrinsicsOption);
 602   set_has_irreducible_loop(true); // conservative until build_loop_tree() reset it
 603 
 604   if (ProfileTraps RTM_OPT_ONLY( || UseRTMLocking )) {
 605     // Make sure the method being compiled gets its own MDO,
 606     // so we can at least track the decompile_count().
 607     // Need MDO to record RTM code generation state.
 608     method()->ensure_method_data();
 609   }
 610 
 611   Init(::AliasLevel);
 612 
 613 
 614   print_compile_messages();
 615 
 616   _ilt = InlineTree::build_inline_tree_root();
 617 
 618   // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
 619   assert(num_alias_types() >= AliasIdxRaw, "");
 620 
 621 #define MINIMUM_NODE_HASH  1023
 622   // Node list that Iterative GVN will start with
 623   Unique_Node_List for_igvn(comp_arena());
 624   set_for_igvn(&for_igvn);
 625 
 626   // GVN that will be run immediately on new nodes
 627   uint estimated_size = method()->code_size()*4+64;
 628   estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
 629   PhaseGVN gvn(node_arena(), estimated_size);
 630   set_initial_gvn(&gvn);
 631 
 632   print_inlining_init();
 633   { // Scope for timing the parser
 634     TracePhase tp("parse", &timers[_t_parser]);
 635 
 636     // Put top into the hash table ASAP.
 637     initial_gvn()->transform_no_reclaim(top());
 638 
 639     // Set up tf(), start(), and find a CallGenerator.
 640     CallGenerator* cg = NULL;
 641     if (is_osr_compilation()) {
 642       init_tf(TypeFunc::make(method(), /* is_osr_compilation = */ true));
 643       StartNode* s = new StartOSRNode(root(), tf()->domain_sig());
 644       initial_gvn()->set_type_bottom(s);
 645       init_start(s);
 646       cg = CallGenerator::for_osr(method(), entry_bci());
 647     } else {
 648       // Normal case.
 649       init_tf(TypeFunc::make(method()));
 650       StartNode* s = new StartNode(root(), tf()->domain_cc());
 651       initial_gvn()->set_type_bottom(s);
 652       init_start(s);
 653       if (method()->intrinsic_id() == vmIntrinsics::_Reference_get) {
 654         // With java.lang.ref.reference.get() we must go through the
 655         // intrinsic - even when get() is the root
 656         // method of the compile - so that, if necessary, the value in
 657         // the referent field of the reference object gets recorded by
 658         // the pre-barrier code.
 659         cg = find_intrinsic(method(), false);
 660       }
 661       if (cg == NULL) {
 662         float past_uses = method()->interpreter_invocation_count();
 663         float expected_uses = past_uses;
 664         cg = CallGenerator::for_inline(method(), expected_uses);
 665       }
 666     }
 667     if (failing())  return;
 668     if (cg == NULL) {
 669       record_method_not_compilable("cannot parse method");
 670       return;
 671     }
 672     JVMState* jvms = build_start_state(start(), tf());
 673     if ((jvms = cg->generate(jvms)) == NULL) {
 674       if (!failure_reason_is(C2Compiler::retry_class_loading_during_parsing())) {
 675         record_method_not_compilable("method parse failed");
 676       }
 677       return;
 678     }
 679     GraphKit kit(jvms);
 680 
 681     if (!kit.stopped()) {
 682       // Accept return values, and transfer control we know not where.
 683       // This is done by a special, unique ReturnNode bound to root.
 684       return_values(kit.jvms());
 685     }
 686 
 687     if (kit.has_exceptions()) {
 688       // Any exceptions that escape from this call must be rethrown
 689       // to whatever caller is dynamically above us on the stack.
 690       // This is done by a special, unique RethrowNode bound to root.
 691       rethrow_exceptions(kit.transfer_exceptions_into_jvms());
 692     }
 693 
 694     assert(IncrementalInline || (_late_inlines.length() == 0 && !has_mh_late_inlines()), "incremental inlining is off");
 695 
 696     if (_late_inlines.length() == 0 && !has_mh_late_inlines() && !failing() && has_stringbuilder()) {
 697       inline_string_calls(true);
 698     }
 699 
 700     if (failing())  return;
 701 
 702     print_method(PHASE_BEFORE_REMOVEUSELESS, 3);
 703 
 704     // Remove clutter produced by parsing.
 705     if (!failing()) {
 706       ResourceMark rm;
 707       PhaseRemoveUseless pru(initial_gvn(), &for_igvn);
 708     }
 709   }
 710 
 711   // Note:  Large methods are capped off in do_one_bytecode().
 712   if (failing())  return;
 713 
 714   // After parsing, node notes are no longer automagic.
 715   // They must be propagated by register_new_node_with_optimizer(),
 716   // clone(), or the like.
 717   set_default_node_notes(NULL);
 718 
 719   for (;;) {
 720     int successes = Inline_Warm();
 721     if (failing())  return;
 722     if (successes == 0)  break;
 723   }
 724 
 725   // Drain the list.
 726   Finish_Warm();
 727 #ifndef PRODUCT
 728   if (should_print(1)) {
 729     _printer->print_inlining();
 730   }
 731 #endif
 732 
 733   if (failing())  return;
 734   NOT_PRODUCT( verify_graph_edges(); )
 735 
 736   // Now optimize
 737   Optimize();
 738   if (failing())  return;
 739   NOT_PRODUCT( verify_graph_edges(); )
 740 
 741 #ifndef PRODUCT
 742   if (print_ideal()) {
 743     ttyLocker ttyl;  // keep the following output all in one block
 744     // This output goes directly to the tty, not the compiler log.
 745     // To enable tools to match it up with the compilation activity,
 746     // be sure to tag this tty output with the compile ID.
 747     if (xtty != NULL) {
 748       xtty->head("ideal compile_id='%d'%s", compile_id(),
 749                  is_osr_compilation()    ? " compile_kind='osr'" :
 750                  "");
 751     }
 752     root()->dump(9999);
 753     if (xtty != NULL) {
 754       xtty->tail("ideal");
 755     }
 756   }
 757 #endif
 758 
 759 #ifdef ASSERT
 760   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 761   bs->verify_gc_barriers(this, BarrierSetC2::BeforeCodeGen);
 762 #endif
 763 
 764   // Dump compilation data to replay it.
 765   if (directive->DumpReplayOption) {
 766     env()->dump_replay_data(_compile_id);
 767   }
 768   if (directive->DumpInlineOption && (ilt() != NULL)) {
 769     env()->dump_inline_data(_compile_id);
 770   }
 771 
 772   // Now that we know the size of all the monitors we can add a fixed slot
 773   // for the original deopt pc.
 774   int next_slot = fixed_slots() + (sizeof(address) / VMRegImpl::stack_slot_size);
 775   if (needs_stack_repair()) {
 776     // One extra slot for the special stack increment value
 777     next_slot += 2;
 778   }
 779   set_fixed_slots(next_slot);
 780 
 781   // Compute when to use implicit null checks. Used by matching trap based
 782   // nodes and NullCheck optimization.
 783   set_allowed_deopt_reasons();
 784 
 785   // Now generate code
 786   Code_Gen();
 787 }
 788 
 789 //------------------------------Compile----------------------------------------
 790 // Compile a runtime stub
 791 Compile::Compile( ciEnv* ci_env,
 792                   TypeFunc_generator generator,
 793                   address stub_function,
 794                   const char *stub_name,
 795                   int is_fancy_jump,
 796                   bool pass_tls,
 797                   bool save_arg_registers,
 798                   bool return_pc,
 799                   DirectiveSet* directive)
 800   : Phase(Compiler),
 801     _compile_id(0),
 802     _save_argument_registers(save_arg_registers),
 803     _subsume_loads(true),
 804     _do_escape_analysis(false),
 805     _install_code(true),
 806     _eliminate_boxing(false),
 807     _method(NULL),
 808     _entry_bci(InvocationEntryBci),
 809     _stub_function(stub_function),
 810     _stub_name(stub_name),
 811     _stub_entry_point(NULL),
 812     _max_node_limit(MaxNodeLimit),
 813     _inlining_progress(false),
 814     _inlining_incrementally(false),
 815     _has_reserved_stack_access(false),
 816 #ifndef PRODUCT
 817     _trace_opto_output(directive->TraceOptoOutputOption),
 818     _print_ideal(directive->PrintIdealOption),
 819 #endif
 820     _has_method_handle_invokes(false),
 821     _clinit_barrier_on_entry(false),
 822     _comp_arena(mtCompiler),
 823     _barrier_set_state(BarrierSet::barrier_set()->barrier_set_c2()->create_barrier_state(comp_arena())),
 824     _env(ci_env),
 825     _directive(directive),
 826     _log(ci_env->log()),
 827     _failure_reason(NULL),
 828     _congraph(NULL),
 829     NOT_PRODUCT(_printer(NULL) COMMA)
 830     _dead_node_list(comp_arena()),
 831     _dead_node_count(0),
 832     _node_arena(mtCompiler),
 833     _old_arena(mtCompiler),
 834     _mach_constant_base_node(NULL),
 835     _Compile_types(mtCompiler),
 836     _initial_gvn(NULL),
 837     _for_igvn(NULL),
 838     _warm_calls(NULL),
 839     _number_of_mh_late_inlines(0),
 840     _print_inlining_stream(NULL),
 841     _print_inlining_list(NULL),
 842     _print_inlining_idx(0),
 843     _print_inlining_output(NULL),
 844     _replay_inline_data(NULL),
 845     _java_calls(0),
 846     _inner_loops(0),
 847     _interpreter_frame_size(0),
 848 #ifndef PRODUCT
 849     _in_dump_cnt(0),
 850 #endif
 851     _allowed_reasons(0) {
 852   C = this;
 853 
 854   TraceTime t1(NULL, &_t_totalCompilation, CITime, false);
 855   TraceTime t2(NULL, &_t_stubCompilation, CITime, false);
 856 
 857 #ifndef PRODUCT
 858   set_print_assembly(PrintFrameConverterAssembly);
 859   set_parsed_irreducible_loop(false);
 860 #else
 861   set_print_assembly(false); // Must initialize.
 862 #endif
 863   set_has_irreducible_loop(false); // no loops
 864 
 865   CompileWrapper cw(this);
 866   Init(/*AliasLevel=*/ 0);
 867   init_tf((*generator)());
 868 
 869   {
 870     // The following is a dummy for the sake of GraphKit::gen_stub
 871     Unique_Node_List for_igvn(comp_arena());
 872     set_for_igvn(&for_igvn);  // not used, but some GraphKit guys push on this
 873     PhaseGVN gvn(Thread::current()->resource_area(),255);
 874     set_initial_gvn(&gvn);    // not significant, but GraphKit guys use it pervasively
 875     gvn.transform_no_reclaim(top());
 876 
 877     GraphKit kit;
 878     kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
 879   }
 880 
 881   NOT_PRODUCT( verify_graph_edges(); )
 882 
 883   Code_Gen();
 884 }
 885 
 886 //------------------------------Init-------------------------------------------
 887 // Prepare for a single compilation
 888 void Compile::Init(int aliaslevel) {
 889   _unique  = 0;
 890   _regalloc = NULL;
 891 
 892   _tf      = NULL;  // filled in later
 893   _top     = NULL;  // cached later
 894   _matcher = NULL;  // filled in later
 895   _cfg     = NULL;  // filled in later
 896 
 897   IA32_ONLY( set_24_bit_selection_and_mode(true, false); )
 898 
 899   _node_note_array = NULL;
 900   _default_node_notes = NULL;
 901   DEBUG_ONLY( _modified_nodes = NULL; ) // Used in Optimize()
 902 
 903   _immutable_memory = NULL; // filled in at first inquiry
 904 
 905   // Globally visible Nodes
 906   // First set TOP to NULL to give safe behavior during creation of RootNode
 907   set_cached_top_node(NULL);
 908   set_root(new RootNode());
 909   // Now that you have a Root to point to, create the real TOP
 910   set_cached_top_node( new ConNode(Type::TOP) );
 911   set_recent_alloc(NULL, NULL);
 912 
 913   // Create Debug Information Recorder to record scopes, oopmaps, etc.
 914   env()->set_oop_recorder(new OopRecorder(env()->arena()));
 915   env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
 916   env()->set_dependencies(new Dependencies(env()));
 917 
 918   _fixed_slots = 0;
 919   set_has_split_ifs(false);
 920   set_has_loops(has_method() && method()->has_loops()); // first approximation
 921   set_has_stringbuilder(false);
 922   set_has_boxed_value(false);
 923   _trap_can_recompile = false;  // no traps emitted yet
 924   _major_progress = true; // start out assuming good things will happen
 925   set_has_unsafe_access(false);
 926   set_max_vector_size(0);
 927   set_clear_upper_avx(false);  //false as default for clear upper bits of ymm registers
 928   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
 929   set_decompile_count(0);
 930 
 931   set_do_freq_based_layout(_directive->BlockLayoutByFrequencyOption);
 932   _loop_opts_cnt = LoopOptsCount;
 933   _has_flattened_accesses = false;
 934   _flattened_accesses_share_alias = true;
 935 
 936   set_do_inlining(Inline);
 937   set_max_inline_size(MaxInlineSize);
 938   set_freq_inline_size(FreqInlineSize);
 939   set_do_scheduling(OptoScheduling);
 940   set_do_count_invocations(false);
 941   set_do_method_data_update(false);
 942 
 943   set_do_vector_loop(false);
 944 
 945   if (AllowVectorizeOnDemand) {
 946     if (has_method() && (_directive->VectorizeOption || _directive->VectorizeDebugOption)) {
 947       set_do_vector_loop(true);
 948       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());})
 949     } else if (has_method() && method()->name() != 0 &&
 950                method()->intrinsic_id() == vmIntrinsics::_forEachRemaining) {
 951       set_do_vector_loop(true);
 952     }
 953   }
 954   set_use_cmove(UseCMoveUnconditionally /* || do_vector_loop()*/); //TODO: consider do_vector_loop() mandate use_cmove unconditionally
 955   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());})
 956 
 957   set_age_code(has_method() && method()->profile_aging());
 958   set_rtm_state(NoRTM); // No RTM lock eliding by default
 959   _max_node_limit = _directive->MaxNodeLimitOption;
 960 
 961 #if INCLUDE_RTM_OPT
 962   if (UseRTMLocking && has_method() && (method()->method_data_or_null() != NULL)) {
 963     int rtm_state = method()->method_data()->rtm_state();
 964     if (method_has_option("NoRTMLockEliding") || ((rtm_state & NoRTM) != 0)) {
 965       // Don't generate RTM lock eliding code.
 966       set_rtm_state(NoRTM);
 967     } else if (method_has_option("UseRTMLockEliding") || ((rtm_state & UseRTM) != 0) || !UseRTMDeopt) {
 968       // Generate RTM lock eliding code without abort ratio calculation code.
 969       set_rtm_state(UseRTM);
 970     } else if (UseRTMDeopt) {
 971       // Generate RTM lock eliding code and include abort ratio calculation
 972       // code if UseRTMDeopt is on.
 973       set_rtm_state(ProfileRTM);
 974     }
 975   }
 976 #endif
 977   if (VM_Version::supports_fast_class_init_checks() && has_method() && !is_osr_compilation() && method()->needs_clinit_barrier()) {
 978     set_clinit_barrier_on_entry(true);
 979   }
 980   if (debug_info()->recording_non_safepoints()) {
 981     set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
 982                         (comp_arena(), 8, 0, NULL));
 983     set_default_node_notes(Node_Notes::make(this));
 984   }
 985 
 986   // // -- Initialize types before each compile --
 987   // // Update cached type information
 988   // if( _method && _method->constants() )
 989   //   Type::update_loaded_types(_method, _method->constants());
 990 
 991   // Init alias_type map.
 992   if (!_do_escape_analysis && aliaslevel == 3)
 993     aliaslevel = 2;  // No unique types without escape analysis
 994   _AliasLevel = aliaslevel;
 995   const int grow_ats = 16;
 996   _max_alias_types = grow_ats;
 997   _alias_types   = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
 998   AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType,  grow_ats);
 999   Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
1000   {
1001     for (int i = 0; i < grow_ats; i++)  _alias_types[i] = &ats[i];
1002   }
1003   // Initialize the first few types.
1004   _alias_types[AliasIdxTop]->Init(AliasIdxTop, NULL);
1005   _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
1006   _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
1007   _num_alias_types = AliasIdxRaw+1;
1008   // Zero out the alias type cache.
1009   Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
1010   // A NULL adr_type hits in the cache right away.  Preload the right answer.
1011   probe_alias_cache(NULL)->_index = AliasIdxTop;
1012 
1013   _intrinsics = NULL;
1014   _macro_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1015   _predicate_opaqs = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1016   _expensive_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1017   _range_check_casts = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1018   _opaque4_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1019   _inline_type_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1020   register_library_intrinsics();
1021 #ifdef ASSERT
1022   _type_verify_symmetry = true;
1023   _phase_optimize_finished = false;
1024 #endif
1025 }
1026 
1027 //---------------------------init_start----------------------------------------
1028 // Install the StartNode on this compile object.
1029 void Compile::init_start(StartNode* s) {
1030   if (failing())
1031     return; // already failing
1032   assert(s == start(), "");
1033 }
1034 
1035 /**
1036  * Return the 'StartNode'. We must not have a pending failure, since the ideal graph
1037  * can be in an inconsistent state, i.e., we can get segmentation faults when traversing
1038  * the ideal graph.
1039  */
1040 StartNode* Compile::start() const {
1041   assert (!failing(), "Must not have pending failure. Reason is: %s", failure_reason());
1042   for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
1043     Node* start = root()->fast_out(i);
1044     if (start->is_Start()) {
1045       return start->as_Start();
1046     }
1047   }
1048   fatal("Did not find Start node!");
1049   return NULL;
1050 }
1051 
1052 //-------------------------------immutable_memory-------------------------------------
1053 // Access immutable memory
1054 Node* Compile::immutable_memory() {
1055   if (_immutable_memory != NULL) {
1056     return _immutable_memory;
1057   }
1058   StartNode* s = start();
1059   for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
1060     Node *p = s->fast_out(i);
1061     if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
1062       _immutable_memory = p;
1063       return _immutable_memory;
1064     }
1065   }
1066   ShouldNotReachHere();
1067   return NULL;
1068 }
1069 
1070 //----------------------set_cached_top_node------------------------------------
1071 // Install the cached top node, and make sure Node::is_top works correctly.
1072 void Compile::set_cached_top_node(Node* tn) {
1073   if (tn != NULL)  verify_top(tn);
1074   Node* old_top = _top;
1075   _top = tn;
1076   // Calling Node::setup_is_top allows the nodes the chance to adjust
1077   // their _out arrays.
1078   if (_top != NULL)     _top->setup_is_top();
1079   if (old_top != NULL)  old_top->setup_is_top();
1080   assert(_top == NULL || top()->is_top(), "");
1081 }
1082 
1083 #ifdef ASSERT
1084 uint Compile::count_live_nodes_by_graph_walk() {
1085   Unique_Node_List useful(comp_arena());
1086   // Get useful node list by walking the graph.
1087   identify_useful_nodes(useful);
1088   return useful.size();
1089 }
1090 
1091 void Compile::print_missing_nodes() {
1092 
1093   // Return if CompileLog is NULL and PrintIdealNodeCount is false.
1094   if ((_log == NULL) && (! PrintIdealNodeCount)) {
1095     return;
1096   }
1097 
1098   // This is an expensive function. It is executed only when the user
1099   // specifies VerifyIdealNodeCount option or otherwise knows the
1100   // additional work that needs to be done to identify reachable nodes
1101   // by walking the flow graph and find the missing ones using
1102   // _dead_node_list.
1103 
1104   Unique_Node_List useful(comp_arena());
1105   // Get useful node list by walking the graph.
1106   identify_useful_nodes(useful);
1107 
1108   uint l_nodes = C->live_nodes();
1109   uint l_nodes_by_walk = useful.size();
1110 
1111   if (l_nodes != l_nodes_by_walk) {
1112     if (_log != NULL) {
1113       _log->begin_head("mismatched_nodes count='%d'", abs((int) (l_nodes - l_nodes_by_walk)));
1114       _log->stamp();
1115       _log->end_head();
1116     }
1117     VectorSet& useful_member_set = useful.member_set();
1118     int last_idx = l_nodes_by_walk;
1119     for (int i = 0; i < last_idx; i++) {
1120       if (useful_member_set.test(i)) {
1121         if (_dead_node_list.test(i)) {
1122           if (_log != NULL) {
1123             _log->elem("mismatched_node_info node_idx='%d' type='both live and dead'", i);
1124           }
1125           if (PrintIdealNodeCount) {
1126             // Print the log message to tty
1127               tty->print_cr("mismatched_node idx='%d' both live and dead'", i);
1128               useful.at(i)->dump();
1129           }
1130         }
1131       }
1132       else if (! _dead_node_list.test(i)) {
1133         if (_log != NULL) {
1134           _log->elem("mismatched_node_info node_idx='%d' type='neither live nor dead'", i);
1135         }
1136         if (PrintIdealNodeCount) {
1137           // Print the log message to tty
1138           tty->print_cr("mismatched_node idx='%d' type='neither live nor dead'", i);
1139         }
1140       }
1141     }
1142     if (_log != NULL) {
1143       _log->tail("mismatched_nodes");
1144     }
1145   }
1146 }
1147 void Compile::record_modified_node(Node* n) {
1148   if (_modified_nodes != NULL && !_inlining_incrementally &&
1149       n->outcnt() != 0 && !n->is_Con()) {
1150     _modified_nodes->push(n);
1151   }
1152 }
1153 
1154 void Compile::remove_modified_node(Node* n) {
1155   if (_modified_nodes != NULL) {
1156     _modified_nodes->remove(n);
1157   }
1158 }
1159 #endif
1160 
1161 #ifndef PRODUCT
1162 void Compile::verify_top(Node* tn) const {
1163   if (tn != NULL) {
1164     assert(tn->is_Con(), "top node must be a constant");
1165     assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
1166     assert(tn->in(0) != NULL, "must have live top node");
1167   }
1168 }
1169 #endif
1170 
1171 
1172 ///-------------------Managing Per-Node Debug & Profile Info-------------------
1173 
1174 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
1175   guarantee(arr != NULL, "");
1176   int num_blocks = arr->length();
1177   if (grow_by < num_blocks)  grow_by = num_blocks;
1178   int num_notes = grow_by * _node_notes_block_size;
1179   Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
1180   Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
1181   while (num_notes > 0) {
1182     arr->append(notes);
1183     notes     += _node_notes_block_size;
1184     num_notes -= _node_notes_block_size;
1185   }
1186   assert(num_notes == 0, "exact multiple, please");
1187 }
1188 
1189 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
1190   if (source == NULL || dest == NULL)  return false;
1191 
1192   if (dest->is_Con())
1193     return false;               // Do not push debug info onto constants.
1194 
1195 #ifdef ASSERT
1196   // Leave a bread crumb trail pointing to the original node:
1197   if (dest != NULL && dest != source && dest->debug_orig() == NULL) {
1198     dest->set_debug_orig(source);
1199   }
1200 #endif
1201 
1202   if (node_note_array() == NULL)
1203     return false;               // Not collecting any notes now.
1204 
1205   // This is a copy onto a pre-existing node, which may already have notes.
1206   // If both nodes have notes, do not overwrite any pre-existing notes.
1207   Node_Notes* source_notes = node_notes_at(source->_idx);
1208   if (source_notes == NULL || source_notes->is_clear())  return false;
1209   Node_Notes* dest_notes   = node_notes_at(dest->_idx);
1210   if (dest_notes == NULL || dest_notes->is_clear()) {
1211     return set_node_notes_at(dest->_idx, source_notes);
1212   }
1213 
1214   Node_Notes merged_notes = (*source_notes);
1215   // The order of operations here ensures that dest notes will win...
1216   merged_notes.update_from(dest_notes);
1217   return set_node_notes_at(dest->_idx, &merged_notes);
1218 }
1219 
1220 
1221 //--------------------------allow_range_check_smearing-------------------------
1222 // Gating condition for coalescing similar range checks.
1223 // Sometimes we try 'speculatively' replacing a series of a range checks by a
1224 // single covering check that is at least as strong as any of them.
1225 // If the optimization succeeds, the simplified (strengthened) range check
1226 // will always succeed.  If it fails, we will deopt, and then give up
1227 // on the optimization.
1228 bool Compile::allow_range_check_smearing() const {
1229   // If this method has already thrown a range-check,
1230   // assume it was because we already tried range smearing
1231   // and it failed.
1232   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
1233   return !already_trapped;
1234 }
1235 
1236 
1237 //------------------------------flatten_alias_type-----------------------------
1238 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
1239   int offset = tj->offset();
1240   TypePtr::PTR ptr = tj->ptr();
1241 
1242   // Known instance (scalarizable allocation) alias only with itself.
1243   bool is_known_inst = tj->isa_oopptr() != NULL &&
1244                        tj->is_oopptr()->is_known_instance();
1245 
1246   // Process weird unsafe references.
1247   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
1248     bool default_value_load = EnableValhalla && tj->is_instptr()->klass() == ciEnv::current()->Class_klass();
1249     assert(InlineUnsafeOps || default_value_load, "indeterminate pointers come only from unsafe ops");
1250     assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
1251     tj = TypeOopPtr::BOTTOM;
1252     ptr = tj->ptr();
1253     offset = tj->offset();
1254   }
1255 
1256   // Array pointers need some flattening
1257   const TypeAryPtr *ta = tj->isa_aryptr();
1258   if (ta && ta->is_stable()) {
1259     // Erase stability property for alias analysis.
1260     tj = ta = ta->cast_to_stable(false);
1261   }
1262   if (ta && ta->is_not_flat()) {
1263     // Erase not flat property for alias analysis.
1264     tj = ta = ta->cast_to_not_flat(false);
1265   }
1266   if (ta && ta->is_not_null_free()) {
1267     // Erase not null free property for alias analysis.
1268     tj = ta = ta->cast_to_not_null_free(false);
1269   }
1270 
1271   if( ta && is_known_inst ) {
1272     if ( offset != Type::OffsetBot &&
1273          offset > arrayOopDesc::length_offset_in_bytes() ) {
1274       offset = Type::OffsetBot; // Flatten constant access into array body only
1275       tj = ta = TypeAryPtr::make(ptr, ta->ary(), ta->klass(), true, Type::Offset(offset), ta->field_offset(), ta->instance_id());
1276     }
1277   } else if( ta && _AliasLevel >= 2 ) {
1278     // For arrays indexed by constant indices, we flatten the alias
1279     // space to include all of the array body.  Only the header, klass
1280     // and array length can be accessed un-aliased.
1281     // For flattened inline type array, each field has its own slice so
1282     // we must include the field offset.
1283     if( offset != Type::OffsetBot ) {
1284       if( ta->const_oop() ) { // MethodData* or Method*
1285         offset = Type::OffsetBot;   // Flatten constant access into array body
1286         tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),ta->ary(),ta->klass(),false,Type::Offset(offset), ta->field_offset());
1287       } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
1288         // range is OK as-is.
1289         tj = ta = TypeAryPtr::RANGE;
1290       } else if( offset == oopDesc::klass_offset_in_bytes() ) {
1291         tj = TypeInstPtr::KLASS; // all klass loads look alike
1292         ta = TypeAryPtr::RANGE; // generic ignored junk
1293         ptr = TypePtr::BotPTR;
1294       } else if( offset == oopDesc::mark_offset_in_bytes() ) {
1295         tj = TypeInstPtr::MARK;
1296         ta = TypeAryPtr::RANGE; // generic ignored junk
1297         ptr = TypePtr::BotPTR;
1298       } else {                  // Random constant offset into array body
1299         offset = Type::OffsetBot;   // Flatten constant access into array body
1300         tj = ta = TypeAryPtr::make(ptr,ta->ary(),ta->klass(),false,Type::Offset(offset), ta->field_offset());
1301       }
1302     }
1303     // Arrays of fixed size alias with arrays of unknown size.
1304     if (ta->size() != TypeInt::POS) {
1305       const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
1306       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,ta->klass(),false,Type::Offset(offset), ta->field_offset());
1307     }
1308     // Arrays of known objects become arrays of unknown objects.
1309     if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
1310       const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
1311       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,Type::Offset(offset), ta->field_offset());
1312     }
1313     if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
1314       const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
1315       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,Type::Offset(offset), ta->field_offset());
1316     }
1317     // Initially all flattened array accesses share a single slice
1318     if (ta->is_flat() && ta->elem() != TypeInlineType::BOTTOM && _flattened_accesses_share_alias) {
1319       const TypeAry *tary = TypeAry::make(TypeInlineType::BOTTOM, ta->size());
1320       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,Type::Offset(offset), Type::Offset(Type::OffsetBot));
1321     }
1322     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
1323     // cannot be distinguished by bytecode alone.
1324     if (ta->elem() == TypeInt::BOOL) {
1325       const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
1326       ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
1327       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,Type::Offset(offset), ta->field_offset());
1328     }
1329     // During the 2nd round of IterGVN, NotNull castings are removed.
1330     // Make sure the Bottom and NotNull variants alias the same.
1331     // Also, make sure exact and non-exact variants alias the same.
1332     if (ptr == TypePtr::NotNull || ta->klass_is_exact() || ta->speculative() != NULL) {
1333       tj = ta = TypeAryPtr::make(TypePtr::BotPTR,ta->ary(),ta->klass(),false,Type::Offset(offset), ta->field_offset());
1334     }
1335   }
1336 
1337   // Oop pointers need some flattening
1338   const TypeInstPtr *to = tj->isa_instptr();
1339   if( to && _AliasLevel >= 2 && to != TypeOopPtr::BOTTOM ) {
1340     ciInstanceKlass *k = to->klass()->as_instance_klass();
1341     if( ptr == TypePtr::Constant ) {
1342       if (to->klass() != ciEnv::current()->Class_klass() ||
1343           offset < k->size_helper() * wordSize) {
1344         // No constant oop pointers (such as Strings); they alias with
1345         // unknown strings.
1346         assert(!is_known_inst, "not scalarizable allocation");
1347         tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,Type::Offset(offset));
1348       }
1349     } else if( is_known_inst ) {
1350       tj = to; // Keep NotNull and klass_is_exact for instance type
1351     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
1352       // During the 2nd round of IterGVN, NotNull castings are removed.
1353       // Make sure the Bottom and NotNull variants alias the same.
1354       // Also, make sure exact and non-exact variants alias the same.
1355       tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,Type::Offset(offset));
1356     }
1357     if (to->speculative() != NULL) {
1358       tj = to = TypeInstPtr::make(to->ptr(),to->klass(),to->klass_is_exact(),to->const_oop(),Type::Offset(to->offset()), to->klass()->flatten_array(), to->instance_id());
1359     }
1360     // Canonicalize the holder of this field
1361     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
1362       // First handle header references such as a LoadKlassNode, even if the
1363       // object's klass is unloaded at compile time (4965979).
1364       if (!is_known_inst) { // Do it only for non-instance types
1365         tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, NULL, Type::Offset(offset));
1366       }
1367     } else if (offset < 0 || offset >= k->size_helper() * wordSize) {
1368       // Static fields are in the space above the normal instance
1369       // fields in the java.lang.Class instance.
1370       if (to->klass() != ciEnv::current()->Class_klass()) {
1371         to = NULL;
1372         tj = TypeOopPtr::BOTTOM;
1373         offset = tj->offset();
1374       }
1375     } else {
1376       ciInstanceKlass *canonical_holder = k->get_canonical_holder(offset);
1377       if (!k->equals(canonical_holder) || tj->offset() != offset) {
1378         if( is_known_inst ) {
1379           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, true, NULL, Type::Offset(offset), canonical_holder->flatten_array(), to->instance_id());
1380         } else {
1381           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, false, NULL, Type::Offset(offset));
1382         }
1383       }
1384     }
1385   }
1386 
1387   // Klass pointers to object array klasses need some flattening
1388   const TypeKlassPtr *tk = tj->isa_klassptr();
1389   if( tk ) {
1390     // If we are referencing a field within a Klass, we need
1391     // to assume the worst case of an Object.  Both exact and
1392     // inexact types must flatten to the same alias class so
1393     // use NotNull as the PTR.
1394     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
1395 
1396       tj = tk = TypeKlassPtr::make(TypePtr::NotNull,
1397                                    TypeKlassPtr::OBJECT->klass(),
1398                                    Type::Offset(offset));
1399     }
1400 
1401     ciKlass* klass = tk->klass();
1402     if (klass != NULL && klass->is_obj_array_klass()) {
1403       ciKlass* k = TypeAryPtr::OOPS->klass();
1404       if( !k || !k->is_loaded() )                  // Only fails for some -Xcomp runs
1405         k = TypeInstPtr::BOTTOM->klass();
1406       tj = tk = TypeKlassPtr::make(TypePtr::NotNull, k, Type::Offset(offset));
1407     }
1408 
1409     // Check for precise loads from the primary supertype array and force them
1410     // to the supertype cache alias index.  Check for generic array loads from
1411     // the primary supertype array and also force them to the supertype cache
1412     // alias index.  Since the same load can reach both, we need to merge
1413     // these 2 disparate memories into the same alias class.  Since the
1414     // primary supertype array is read-only, there's no chance of confusion
1415     // where we bypass an array load and an array store.
1416     int primary_supers_offset = in_bytes(Klass::primary_supers_offset());
1417     if (offset == Type::OffsetBot ||
1418         (offset >= primary_supers_offset &&
1419          offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
1420         offset == (int)in_bytes(Klass::secondary_super_cache_offset())) {
1421       offset = in_bytes(Klass::secondary_super_cache_offset());
1422       tj = tk = TypeKlassPtr::make(TypePtr::NotNull, tk->klass(), Type::Offset(offset));
1423     }
1424   }
1425 
1426   // Flatten all Raw pointers together.
1427   if (tj->base() == Type::RawPtr)
1428     tj = TypeRawPtr::BOTTOM;
1429 
1430   if (tj->base() == Type::AnyPtr)
1431     tj = TypePtr::BOTTOM;      // An error, which the caller must check for.
1432 
1433   // Flatten all to bottom for now
1434   switch( _AliasLevel ) {
1435   case 0:
1436     tj = TypePtr::BOTTOM;
1437     break;
1438   case 1:                       // Flatten to: oop, static, field or array
1439     switch (tj->base()) {
1440     //case Type::AryPtr: tj = TypeAryPtr::RANGE;    break;
1441     case Type::RawPtr:   tj = TypeRawPtr::BOTTOM;   break;
1442     case Type::AryPtr:   // do not distinguish arrays at all
1443     case Type::InstPtr:  tj = TypeInstPtr::BOTTOM;  break;
1444     case Type::KlassPtr: tj = TypeKlassPtr::OBJECT; break;
1445     case Type::AnyPtr:   tj = TypePtr::BOTTOM;      break;  // caller checks it
1446     default: ShouldNotReachHere();
1447     }
1448     break;
1449   case 2:                       // No collapsing at level 2; keep all splits
1450   case 3:                       // No collapsing at level 3; keep all splits
1451     break;
1452   default:
1453     Unimplemented();
1454   }
1455 
1456   offset = tj->offset();
1457   assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
1458 
1459   assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
1460           (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
1461           (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
1462           (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
1463           (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1464           (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1465           (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr),
1466           "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
1467   assert( tj->ptr() != TypePtr::TopPTR &&
1468           tj->ptr() != TypePtr::AnyNull &&
1469           tj->ptr() != TypePtr::Null, "No imprecise addresses" );
1470 //    assert( tj->ptr() != TypePtr::Constant ||
1471 //            tj->base() == Type::RawPtr ||
1472 //            tj->base() == Type::KlassPtr, "No constant oop addresses" );
1473 
1474   return tj;
1475 }
1476 
1477 void Compile::AliasType::Init(int i, const TypePtr* at) {
1478   assert(AliasIdxTop <= i && i < Compile::current()->_max_alias_types, "Invalid alias index");
1479   _index = i;
1480   _adr_type = at;
1481   _field = NULL;
1482   _element = NULL;
1483   _is_rewritable = true; // default
1484   const TypeOopPtr *atoop = (at != NULL) ? at->isa_oopptr() : NULL;
1485   if (atoop != NULL && atoop->is_known_instance()) {
1486     const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
1487     _general_index = Compile::current()->get_alias_index(gt);
1488   } else {
1489     _general_index = 0;
1490   }
1491 }
1492 
1493 BasicType Compile::AliasType::basic_type() const {
1494   if (element() != NULL) {
1495     const Type* element = adr_type()->is_aryptr()->elem();
1496     return element->isa_narrowoop() ? T_OBJECT : element->array_element_basic_type();
1497   } if (field() != NULL) {
1498     return field()->layout_type();
1499   } else {
1500     return T_ILLEGAL; // unknown
1501   }
1502 }
1503 
1504 //---------------------------------print_on------------------------------------
1505 #ifndef PRODUCT
1506 void Compile::AliasType::print_on(outputStream* st) {
1507   if (index() < 10)
1508         st->print("@ <%d> ", index());
1509   else  st->print("@ <%d>",  index());
1510   st->print(is_rewritable() ? "   " : " RO");
1511   int offset = adr_type()->offset();
1512   if (offset == Type::OffsetBot)
1513         st->print(" +any");
1514   else  st->print(" +%-3d", offset);
1515   st->print(" in ");
1516   adr_type()->dump_on(st);
1517   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
1518   if (field() != NULL && tjp) {
1519     if (tjp->klass()  != field()->holder() ||
1520         tjp->offset() != field()->offset_in_bytes()) {
1521       st->print(" != ");
1522       field()->print();
1523       st->print(" ***");
1524     }
1525   }
1526 }
1527 
1528 void print_alias_types() {
1529   Compile* C = Compile::current();
1530   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
1531   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
1532     C->alias_type(idx)->print_on(tty);
1533     tty->cr();
1534   }
1535 }
1536 #endif
1537 
1538 
1539 //----------------------------probe_alias_cache--------------------------------
1540 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
1541   intptr_t key = (intptr_t) adr_type;
1542   key ^= key >> logAliasCacheSize;
1543   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
1544 }
1545 
1546 
1547 //-----------------------------grow_alias_types--------------------------------
1548 void Compile::grow_alias_types() {
1549   const int old_ats  = _max_alias_types; // how many before?
1550   const int new_ats  = old_ats;          // how many more?
1551   const int grow_ats = old_ats+new_ats;  // how many now?
1552   _max_alias_types = grow_ats;
1553   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
1554   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
1555   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
1556   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
1557 }
1558 
1559 
1560 //--------------------------------find_alias_type------------------------------
1561 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field, bool uncached) {
1562   if (_AliasLevel == 0)
1563     return alias_type(AliasIdxBot);
1564 
1565   AliasCacheEntry* ace = NULL;
1566   if (!uncached) {
1567     ace = probe_alias_cache(adr_type);
1568     if (ace->_adr_type == adr_type) {
1569       return alias_type(ace->_index);
1570     }
1571   }
1572 
1573   // Handle special cases.
1574   if (adr_type == NULL)             return alias_type(AliasIdxTop);
1575   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
1576 
1577   // Do it the slow way.
1578   const TypePtr* flat = flatten_alias_type(adr_type);
1579 
1580 #ifdef ASSERT
1581   {
1582     ResourceMark rm;
1583     assert(flat == flatten_alias_type(flat), "not idempotent: adr_type = %s; flat = %s => %s",
1584            Type::str(adr_type), Type::str(flat), Type::str(flatten_alias_type(flat)));
1585     assert(flat != TypePtr::BOTTOM, "cannot alias-analyze an untyped ptr: adr_type = %s",
1586            Type::str(adr_type));
1587     if (flat->isa_oopptr() && !flat->isa_klassptr()) {
1588       const TypeOopPtr* foop = flat->is_oopptr();
1589       // Scalarizable allocations have exact klass always.
1590       bool exact = !foop->klass_is_exact() || foop->is_known_instance();
1591       const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
1592       assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type: foop = %s; xoop = %s",
1593              Type::str(foop), Type::str(xoop));
1594     }
1595   }
1596 #endif
1597 
1598   int idx = AliasIdxTop;
1599   for (int i = 0; i < num_alias_types(); i++) {
1600     if (alias_type(i)->adr_type() == flat) {
1601       idx = i;
1602       break;
1603     }
1604   }
1605 
1606   if (idx == AliasIdxTop) {
1607     if (no_create)  return NULL;
1608     // Grow the array if necessary.
1609     if (_num_alias_types == _max_alias_types)  grow_alias_types();
1610     // Add a new alias type.
1611     idx = _num_alias_types++;
1612     _alias_types[idx]->Init(idx, flat);
1613     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
1614     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
1615     if (flat->isa_instptr()) {
1616       if (flat->offset() == java_lang_Class::klass_offset()
1617           && flat->is_instptr()->klass() == env()->Class_klass())
1618         alias_type(idx)->set_rewritable(false);
1619     }
1620     ciField* field = NULL;
1621     if (flat->isa_aryptr()) {
1622 #ifdef ASSERT
1623       const int header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1624       // (T_BYTE has the weakest alignment and size restrictions...)
1625       assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
1626 #endif
1627       const Type* elemtype = flat->is_aryptr()->elem();
1628       if (flat->offset() == TypePtr::OffsetBot) {
1629         alias_type(idx)->set_element(elemtype);
1630       }
1631       int field_offset = flat->is_aryptr()->field_offset().get();
1632       if (elemtype->isa_inlinetype() &&
1633           elemtype->inline_klass() != NULL &&
1634           field_offset != Type::OffsetBot) {
1635         ciInlineKlass* vk = elemtype->inline_klass();
1636         field_offset += vk->first_field_offset();
1637         field = vk->get_field_by_offset(field_offset, false);
1638       }
1639     }
1640     if (flat->isa_klassptr()) {
1641       if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
1642         alias_type(idx)->set_rewritable(false);
1643       if (flat->offset() == in_bytes(Klass::modifier_flags_offset()))
1644         alias_type(idx)->set_rewritable(false);
1645       if (flat->offset() == in_bytes(Klass::access_flags_offset()))
1646         alias_type(idx)->set_rewritable(false);
1647       if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
1648         alias_type(idx)->set_rewritable(false);
1649       if (flat->offset() == in_bytes(Klass::layout_helper_offset()))
1650         alias_type(idx)->set_rewritable(false);
1651       if (flat->offset() == in_bytes(Klass::secondary_super_cache_offset()))
1652         alias_type(idx)->set_rewritable(false);
1653     }
1654     // %%% (We would like to finalize JavaThread::threadObj_offset(),
1655     // but the base pointer type is not distinctive enough to identify
1656     // references into JavaThread.)
1657 
1658     // Check for final fields.
1659     const TypeInstPtr* tinst = flat->isa_instptr();
1660     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
1661       if (tinst->const_oop() != NULL &&
1662           tinst->klass() == ciEnv::current()->Class_klass() &&
1663           tinst->offset() >= (tinst->klass()->as_instance_klass()->size_helper() * wordSize)) {
1664         // static field
1665         ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
1666         field = k->get_field_by_offset(tinst->offset(), true);
1667       } else if (tinst->klass()->is_inlinetype()) {
1668         // Inline type field
1669         ciInlineKlass* vk = tinst->inline_klass();
1670         field = vk->get_field_by_offset(tinst->offset(), false);
1671       } else {
1672         ciInstanceKlass* k = tinst->klass()->as_instance_klass();
1673         field = k->get_field_by_offset(tinst->offset(), false);
1674       }
1675     }
1676     assert(field == NULL ||
1677            original_field == NULL ||
1678            (field->holder() == original_field->holder() &&
1679             field->offset() == original_field->offset() &&
1680             field->is_static() == original_field->is_static()), "wrong field?");
1681     // Set field() and is_rewritable() attributes.
1682     if (field != NULL) {
1683       alias_type(idx)->set_field(field);
1684       if (flat->isa_aryptr()) {
1685         // Fields of flat arrays are rewritable although they are declared final
1686         assert(flat->is_aryptr()->is_flat(), "must be a flat array");
1687         alias_type(idx)->set_rewritable(true);
1688       }
1689     }
1690   }
1691 
1692   // Fill the cache for next time.
1693   if (!uncached) {
1694     ace->_adr_type = adr_type;
1695     ace->_index    = idx;
1696     assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
1697 
1698     // Might as well try to fill the cache for the flattened version, too.
1699     AliasCacheEntry* face = probe_alias_cache(flat);
1700     if (face->_adr_type == NULL) {
1701       face->_adr_type = flat;
1702       face->_index    = idx;
1703       assert(alias_type(flat) == alias_type(idx), "flat type must work too");
1704     }
1705   }
1706 
1707   return alias_type(idx);
1708 }
1709 
1710 
1711 Compile::AliasType* Compile::alias_type(ciField* field) {
1712   const TypeOopPtr* t;
1713   if (field->is_static())
1714     t = TypeInstPtr::make(field->holder()->java_mirror());
1715   else
1716     t = TypeOopPtr::make_from_klass_raw(field->holder());
1717   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);
1718   assert((field->is_final() || field->is_stable()) == !atp->is_rewritable(), "must get the rewritable bits correct");
1719   return atp;
1720 }
1721 
1722 
1723 //------------------------------have_alias_type--------------------------------
1724 bool Compile::have_alias_type(const TypePtr* adr_type) {
1725   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1726   if (ace->_adr_type == adr_type) {
1727     return true;
1728   }
1729 
1730   // Handle special cases.
1731   if (adr_type == NULL)             return true;
1732   if (adr_type == TypePtr::BOTTOM)  return true;
1733 
1734   return find_alias_type(adr_type, true, NULL) != NULL;
1735 }
1736 
1737 //-----------------------------must_alias--------------------------------------
1738 // True if all values of the given address type are in the given alias category.
1739 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
1740   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1741   if (adr_type == NULL)                 return true;  // NULL serves as TypePtr::TOP
1742   if (alias_idx == AliasIdxTop)         return false; // the empty category
1743   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
1744 
1745   // the only remaining possible overlap is identity
1746   int adr_idx = get_alias_index(adr_type);
1747   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1748   assert(adr_idx == alias_idx ||
1749          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
1750           && adr_type                       != TypeOopPtr::BOTTOM),
1751          "should not be testing for overlap with an unsafe pointer");
1752   return adr_idx == alias_idx;
1753 }
1754 
1755 //------------------------------can_alias--------------------------------------
1756 // True if any values of the given address type are in the given alias category.
1757 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
1758   if (alias_idx == AliasIdxTop)         return false; // the empty category
1759   if (adr_type == NULL)                 return false; // NULL serves as TypePtr::TOP
1760   // Known instance doesn't alias with bottom memory
1761   if (alias_idx == AliasIdxBot)         return !adr_type->is_known_instance();                   // the universal category
1762   if (adr_type->base() == Type::AnyPtr) return !C->get_adr_type(alias_idx)->is_known_instance(); // TypePtr::BOTTOM or its twins
1763 
1764   // the only remaining possible overlap is identity
1765   int adr_idx = get_alias_index(adr_type);
1766   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1767   return adr_idx == alias_idx;
1768 }
1769 
1770 
1771 
1772 //---------------------------pop_warm_call-------------------------------------
1773 WarmCallInfo* Compile::pop_warm_call() {
1774   WarmCallInfo* wci = _warm_calls;
1775   if (wci != NULL)  _warm_calls = wci->remove_from(wci);
1776   return wci;
1777 }
1778 
1779 //----------------------------Inline_Warm--------------------------------------
1780 int Compile::Inline_Warm() {
1781   // If there is room, try to inline some more warm call sites.
1782   // %%% Do a graph index compaction pass when we think we're out of space?
1783   if (!InlineWarmCalls)  return 0;
1784 
1785   int calls_made_hot = 0;
1786   int room_to_grow   = NodeCountInliningCutoff - unique();
1787   int amount_to_grow = MIN2(room_to_grow, (int)NodeCountInliningStep);
1788   int amount_grown   = 0;
1789   WarmCallInfo* call;
1790   while (amount_to_grow > 0 && (call = pop_warm_call()) != NULL) {
1791     int est_size = (int)call->size();
1792     if (est_size > (room_to_grow - amount_grown)) {
1793       // This one won't fit anyway.  Get rid of it.
1794       call->make_cold();
1795       continue;
1796     }
1797     call->make_hot();
1798     calls_made_hot++;
1799     amount_grown   += est_size;
1800     amount_to_grow -= est_size;
1801   }
1802 
1803   if (calls_made_hot > 0)  set_major_progress();
1804   return calls_made_hot;
1805 }
1806 
1807 
1808 //----------------------------Finish_Warm--------------------------------------
1809 void Compile::Finish_Warm() {
1810   if (!InlineWarmCalls)  return;
1811   if (failing())  return;
1812   if (warm_calls() == NULL)  return;
1813 
1814   // Clean up loose ends, if we are out of space for inlining.
1815   WarmCallInfo* call;
1816   while ((call = pop_warm_call()) != NULL) {
1817     call->make_cold();
1818   }
1819 }
1820 
1821 //---------------------cleanup_loop_predicates-----------------------
1822 // Remove the opaque nodes that protect the predicates so that all unused
1823 // checks and uncommon_traps will be eliminated from the ideal graph
1824 void Compile::cleanup_loop_predicates(PhaseIterGVN &igvn) {
1825   if (predicate_count()==0) return;
1826   for (int i = predicate_count(); i > 0; i--) {
1827     Node * n = predicate_opaque1_node(i-1);
1828     assert(n->Opcode() == Op_Opaque1, "must be");
1829     igvn.replace_node(n, n->in(1));
1830   }
1831   assert(predicate_count()==0, "should be clean!");
1832 }
1833 
1834 void Compile::add_range_check_cast(Node* n) {
1835   assert(n->isa_CastII()->has_range_check(), "CastII should have range check dependency");
1836   assert(!_range_check_casts->contains(n), "duplicate entry in range check casts");
1837   _range_check_casts->append(n);
1838 }
1839 
1840 // Remove all range check dependent CastIINodes.
1841 void Compile::remove_range_check_casts(PhaseIterGVN &igvn) {
1842   for (int i = range_check_cast_count(); i > 0; i--) {
1843     Node* cast = range_check_cast_node(i-1);
1844     assert(cast->isa_CastII()->has_range_check(), "CastII should have range check dependency");
1845     igvn.replace_node(cast, cast->in(1));
1846   }
1847   assert(range_check_cast_count() == 0, "should be empty");
1848 }
1849 
1850 void Compile::add_opaque4_node(Node* n) {
1851   assert(n->Opcode() == Op_Opaque4, "Opaque4 only");
1852   assert(!_opaque4_nodes->contains(n), "duplicate entry in Opaque4 list");
1853   _opaque4_nodes->append(n);
1854 }
1855 
1856 // Remove all Opaque4 nodes.
1857 void Compile::remove_opaque4_nodes(PhaseIterGVN &igvn) {
1858   for (int i = opaque4_count(); i > 0; i--) {
1859     Node* opaq = opaque4_node(i-1);
1860     assert(opaq->Opcode() == Op_Opaque4, "Opaque4 only");
1861     igvn.replace_node(opaq, opaq->in(2));
1862   }
1863   assert(opaque4_count() == 0, "should be empty");
1864 }
1865 
1866 void Compile::add_inline_type(Node* n) {
1867   assert(n->is_InlineTypeBase(), "unexpected node");
1868   if (_inline_type_nodes != NULL) {
1869     _inline_type_nodes->push(n);
1870   }
1871 }
1872 
1873 void Compile::remove_inline_type(Node* n) {
1874   assert(n->is_InlineTypeBase(), "unexpected node");
1875   if (_inline_type_nodes != NULL && _inline_type_nodes->contains(n)) {
1876     _inline_type_nodes->remove(n);
1877   }
1878 }
1879 
1880 // Does the return value keep otherwise useless inline type allocations alive?
1881 static bool return_val_keeps_allocations_alive(Node* ret_val) {
1882   ResourceMark rm;
1883   Unique_Node_List wq;
1884   wq.push(ret_val);
1885   bool some_allocations = false;
1886   for (uint i = 0; i < wq.size(); i++) {
1887     Node* n = wq.at(i);
1888     assert(!n->is_InlineType(), "chain of inline type nodes");
1889     if (n->outcnt() > 1) {
1890       // Some other use for the allocation
1891       return false;
1892     } else if (n->is_InlineTypePtr()) {
1893       wq.push(n->in(1));
1894     } else if (n->is_Phi()) {
1895       for (uint j = 1; j < n->req(); j++) {
1896         wq.push(n->in(j));
1897       }
1898     } else if (n->is_CheckCastPP() &&
1899                n->in(1)->is_Proj() &&
1900                n->in(1)->in(0)->is_Allocate()) {
1901       some_allocations = true;
1902     }
1903   }
1904   return some_allocations;
1905 }
1906 
1907 void Compile::process_inline_types(PhaseIterGVN &igvn, bool post_ea) {
1908   // Make inline types scalar in safepoints
1909   for (int i = _inline_type_nodes->length()-1; i >= 0; i--) {
1910     InlineTypeBaseNode* vt = _inline_type_nodes->at(i)->as_InlineTypeBase();
1911     vt->make_scalar_in_safepoints(&igvn);
1912   }
1913   // Remove InlineTypePtr nodes only after EA to give scalar replacement a chance
1914   // to remove buffer allocations. InlineType nodes are kept until loop opts and
1915   // removed via InlineTypeNode::remove_redundant_allocations.
1916   if (post_ea) {
1917     while (_inline_type_nodes->length() > 0) {
1918       InlineTypeBaseNode* vt = _inline_type_nodes->pop()->as_InlineTypeBase();
1919       if (vt->is_InlineTypePtr()) {
1920         igvn.replace_node(vt, vt->get_oop());
1921       }
1922     }
1923   }
1924   // Make sure that the return value does not keep an unused allocation alive
1925   if (tf()->returns_inline_type_as_fields()) {
1926     Node* ret = NULL;
1927     for (uint i = 1; i < root()->req(); i++){
1928       Node* in = root()->in(i);
1929       if (in->Opcode() == Op_Return) {
1930         assert(ret == NULL, "only one return");
1931         ret = in;
1932       }
1933     }
1934     if (ret != NULL) {
1935       Node* ret_val = ret->in(TypeFunc::Parms);
1936       if (igvn.type(ret_val)->isa_oopptr() &&
1937           return_val_keeps_allocations_alive(ret_val)) {
1938         igvn.replace_input_of(ret, TypeFunc::Parms, InlineTypeNode::tagged_klass(igvn.type(ret_val)->inline_klass(), igvn));
1939         assert(ret_val->outcnt() == 0, "should be dead now");
1940         igvn.remove_dead_node(ret_val);
1941       }
1942     }
1943   }
1944   igvn.optimize();
1945 }
1946 
1947 void Compile::adjust_flattened_array_access_aliases(PhaseIterGVN& igvn) {
1948   if (!_has_flattened_accesses) {
1949     return;
1950   }
1951   // Initially, all flattened array accesses share the same slice to
1952   // keep dependencies with Object[] array accesses (that could be
1953   // to a flattened array) correct. We're done with parsing so we
1954   // now know all flattened array accesses in this compile
1955   // unit. Let's move flattened array accesses to their own slice,
1956   // one per element field. This should help memory access
1957   // optimizations.
1958   ResourceMark rm;
1959   Unique_Node_List wq;
1960   wq.push(root());
1961 
1962   Node_List mergememnodes;
1963   Node_List memnodes;
1964 
1965   // Alias index currently shared by all flattened memory accesses
1966   int index = get_alias_index(TypeAryPtr::INLINES);
1967 
1968   // Find MergeMem nodes and flattened array accesses
1969   for (uint i = 0; i < wq.size(); i++) {
1970     Node* n = wq.at(i);
1971     if (n->is_Mem()) {
1972       const TypePtr* adr_type = NULL;
1973       if (n->Opcode() == Op_StoreCM) {
1974         adr_type = get_adr_type(get_alias_index(n->in(MemNode::OopStore)->adr_type()));
1975       } else {
1976         adr_type = get_adr_type(get_alias_index(n->adr_type()));
1977       }
1978       if (adr_type == TypeAryPtr::INLINES) {
1979         memnodes.push(n);
1980       }
1981     } else if (n->is_MergeMem()) {
1982       MergeMemNode* mm = n->as_MergeMem();
1983       if (mm->memory_at(index) != mm->base_memory()) {
1984         mergememnodes.push(n);
1985       }
1986     }
1987     for (uint j = 0; j < n->req(); j++) {
1988       Node* m = n->in(j);
1989       if (m != NULL) {
1990         wq.push(m);
1991       }
1992     }
1993   }
1994 
1995   if (memnodes.size() > 0) {
1996     _flattened_accesses_share_alias = false;
1997 
1998     // We are going to change the slice for the flattened array
1999     // accesses so we need to clear the cache entries that refer to
2000     // them.
2001     for (uint i = 0; i < AliasCacheSize; i++) {
2002       AliasCacheEntry* ace = &_alias_cache[i];
2003       if (ace->_adr_type != NULL &&
2004           ace->_adr_type->isa_aryptr() &&
2005           ace->_adr_type->is_aryptr()->is_flat()) {
2006         ace->_adr_type = NULL;
2007         ace->_index = (i != 0) ? 0 : AliasIdxTop; // Make sure the NULL adr_type resolves to AliasIdxTop
2008       }
2009     }
2010 
2011     // Find what aliases we are going to add
2012     int start_alias = num_alias_types()-1;
2013     int stop_alias = 0;
2014 
2015     for (uint i = 0; i < memnodes.size(); i++) {
2016       Node* m = memnodes.at(i);
2017       const TypePtr* adr_type = NULL;
2018       if (m->Opcode() == Op_StoreCM) {
2019         adr_type = m->in(MemNode::OopStore)->adr_type();
2020         Node* clone = new StoreCMNode(m->in(MemNode::Control), m->in(MemNode::Memory), m->in(MemNode::Address),
2021                                       m->adr_type(), m->in(MemNode::ValueIn), m->in(MemNode::OopStore),
2022                                       get_alias_index(adr_type));
2023         igvn.register_new_node_with_optimizer(clone);
2024         igvn.replace_node(m, clone);
2025       } else {
2026         adr_type = m->adr_type();
2027 #ifdef ASSERT
2028         m->as_Mem()->set_adr_type(adr_type);
2029 #endif
2030       }
2031       int idx = get_alias_index(adr_type);
2032       start_alias = MIN2(start_alias, idx);
2033       stop_alias = MAX2(stop_alias, idx);
2034     }
2035 
2036     assert(stop_alias >= start_alias, "should have expanded aliases");
2037 
2038     Node_Stack stack(0);
2039 #ifdef ASSERT
2040     VectorSet seen(Thread::current()->resource_area());
2041 #endif
2042     // Now let's fix the memory graph so each flattened array access
2043     // is moved to the right slice. Start from the MergeMem nodes.
2044     uint last = unique();
2045     for (uint i = 0; i < mergememnodes.size(); i++) {
2046       MergeMemNode* current = mergememnodes.at(i)->as_MergeMem();
2047       Node* n = current->memory_at(index);
2048       MergeMemNode* mm = NULL;
2049       do {
2050         // Follow memory edges through memory accesses, phis and
2051         // narrow membars and push nodes on the stack. Once we hit
2052         // bottom memory, we pop element off the stack one at a
2053         // time, in reverse order, and move them to the right slice
2054         // by changing their memory edges.
2055         if ((n->is_Phi() && n->adr_type() != TypePtr::BOTTOM) || n->is_Mem() || n->adr_type() == TypeAryPtr::INLINES) {
2056           assert(!seen.test_set(n->_idx), "");
2057           // Uses (a load for instance) will need to be moved to the
2058           // right slice as well and will get a new memory state
2059           // that we don't know yet. The use could also be the
2060           // backedge of a loop. We put a place holder node between
2061           // the memory node and its uses. We replace that place
2062           // holder with the correct memory state once we know it,
2063           // i.e. when nodes are popped off the stack. Using the
2064           // place holder make the logic work in the presence of
2065           // loops.
2066           if (n->outcnt() > 1) {
2067             Node* place_holder = NULL;
2068             assert(!n->has_out_with(Op_Node), "");
2069             for (DUIterator k = n->outs(); n->has_out(k); k++) {
2070               Node* u = n->out(k);
2071               if (u != current && u->_idx < last) {
2072                 bool success = false;
2073                 for (uint l = 0; l < u->req(); l++) {
2074                   if (!stack.is_empty() && u == stack.node() && l == stack.index()) {
2075                     continue;
2076                   }
2077                   Node* in = u->in(l);
2078                   if (in == n) {
2079                     if (place_holder == NULL) {
2080                       place_holder = new Node(1);
2081                       place_holder->init_req(0, n);
2082                     }
2083                     igvn.replace_input_of(u, l, place_holder);
2084                     success = true;
2085                   }
2086                 }
2087                 if (success) {
2088                   --k;
2089                 }
2090               }
2091             }
2092           }
2093           if (n->is_Phi()) {
2094             stack.push(n, 1);
2095             n = n->in(1);
2096           } else if (n->is_Mem()) {
2097             stack.push(n, n->req());
2098             n = n->in(MemNode::Memory);
2099           } else {
2100             assert(n->is_Proj() && n->in(0)->Opcode() == Op_MemBarCPUOrder, "");
2101             stack.push(n, n->req());
2102             n = n->in(0)->in(TypeFunc::Memory);
2103           }
2104         } else {
2105           assert(n->adr_type() == TypePtr::BOTTOM || (n->Opcode() == Op_Node && n->_idx >= last) || (n->is_Proj() && n->in(0)->is_Initialize()), "");
2106           // Build a new MergeMem node to carry the new memory state
2107           // as we build it. IGVN should fold extraneous MergeMem
2108           // nodes.
2109           mm = MergeMemNode::make(n);
2110           igvn.register_new_node_with_optimizer(mm);
2111           while (stack.size() > 0) {
2112             Node* m = stack.node();
2113             uint idx = stack.index();
2114             if (m->is_Mem()) {
2115               // Move memory node to its new slice
2116               const TypePtr* adr_type = m->adr_type();
2117               int alias = get_alias_index(adr_type);
2118               Node* prev = mm->memory_at(alias);
2119               igvn.replace_input_of(m, MemNode::Memory, prev);
2120               mm->set_memory_at(alias, m);
2121             } else if (m->is_Phi()) {
2122               // We need as many new phis as there are new aliases
2123               igvn.replace_input_of(m, idx, mm);
2124               if (idx == m->req()-1) {
2125                 Node* r = m->in(0);
2126                 for (uint j = (uint)start_alias; j <= (uint)stop_alias; j++) {
2127                   const Type* adr_type = get_adr_type(j);
2128                   if (!adr_type->isa_aryptr() || !adr_type->is_aryptr()->is_flat()) {
2129                     continue;
2130                   }
2131                   Node* phi = new PhiNode(r, Type::MEMORY, get_adr_type(j));
2132                   igvn.register_new_node_with_optimizer(phi);
2133                   for (uint k = 1; k < m->req(); k++) {
2134                     phi->init_req(k, m->in(k)->as_MergeMem()->memory_at(j));
2135                   }
2136                   mm->set_memory_at(j, phi);
2137                 }
2138                 Node* base_phi = new PhiNode(r, Type::MEMORY, TypePtr::BOTTOM);
2139                 igvn.register_new_node_with_optimizer(base_phi);
2140                 for (uint k = 1; k < m->req(); k++) {
2141                   base_phi->init_req(k, m->in(k)->as_MergeMem()->base_memory());
2142                 }
2143                 mm->set_base_memory(base_phi);
2144               }
2145             } else {
2146               // This is a MemBarCPUOrder node from
2147               // Parse::array_load()/Parse::array_store(), in the
2148               // branch that handles flattened arrays hidden under
2149               // an Object[] array. We also need one new membar per
2150               // new alias to keep the unknown access that the
2151               // membars protect properly ordered with accesses to
2152               // known flattened array.
2153               assert(m->is_Proj(), "projection expected");
2154               Node* ctrl = m->in(0)->in(TypeFunc::Control);
2155               igvn.replace_input_of(m->in(0), TypeFunc::Control, top());
2156               for (uint j = (uint)start_alias; j <= (uint)stop_alias; j++) {
2157                 const Type* adr_type = get_adr_type(j);
2158                 if (!adr_type->isa_aryptr() || !adr_type->is_aryptr()->is_flat()) {
2159                   continue;
2160                 }
2161                 MemBarNode* mb = new MemBarCPUOrderNode(this, j, NULL);
2162                 igvn.register_new_node_with_optimizer(mb);
2163                 Node* mem = mm->memory_at(j);
2164                 mb->init_req(TypeFunc::Control, ctrl);
2165                 mb->init_req(TypeFunc::Memory, mem);
2166                 ctrl = new ProjNode(mb, TypeFunc::Control);
2167                 igvn.register_new_node_with_optimizer(ctrl);
2168                 mem = new ProjNode(mb, TypeFunc::Memory);
2169                 igvn.register_new_node_with_optimizer(mem);
2170                 mm->set_memory_at(j, mem);
2171               }
2172               igvn.replace_node(m->in(0)->as_Multi()->proj_out(TypeFunc::Control), ctrl);
2173             }
2174             if (idx < m->req()-1) {
2175               idx += 1;
2176               stack.set_index(idx);
2177               n = m->in(idx);
2178               break;
2179             }
2180             // Take care of place holder nodes
2181             if (m->has_out_with(Op_Node)) {
2182               Node* place_holder = m->find_out_with(Op_Node);
2183               if (place_holder != NULL) {
2184                 Node* mm_clone = mm->clone();
2185                 igvn.register_new_node_with_optimizer(mm_clone);
2186                 Node* hook = new Node(1);
2187                 hook->init_req(0, mm);
2188                 igvn.replace_node(place_holder, mm_clone);
2189                 hook->destruct();
2190               }
2191               assert(!m->has_out_with(Op_Node), "place holder should be gone now");
2192             }
2193             stack.pop();
2194           }
2195         }
2196       } while(stack.size() > 0);
2197       // Fix the memory state at the MergeMem we started from
2198       igvn.rehash_node_delayed(current);
2199       for (uint j = (uint)start_alias; j <= (uint)stop_alias; j++) {
2200         const Type* adr_type = get_adr_type(j);
2201         if (!adr_type->isa_aryptr() || !adr_type->is_aryptr()->is_flat()) {
2202           continue;
2203         }
2204         current->set_memory_at(j, mm);
2205       }
2206       current->set_memory_at(index, current->base_memory());
2207     }
2208     igvn.optimize();
2209   }
2210   print_method(PHASE_SPLIT_INLINES_ARRAY, 2);
2211 }
2212 
2213 
2214 // StringOpts and late inlining of string methods
2215 void Compile::inline_string_calls(bool parse_time) {
2216   {
2217     // remove useless nodes to make the usage analysis simpler
2218     ResourceMark rm;
2219     PhaseRemoveUseless pru(initial_gvn(), for_igvn());
2220   }
2221 
2222   {
2223     ResourceMark rm;
2224     print_method(PHASE_BEFORE_STRINGOPTS, 3);
2225     PhaseStringOpts pso(initial_gvn(), for_igvn());
2226     print_method(PHASE_AFTER_STRINGOPTS, 3);
2227   }
2228 
2229   // now inline anything that we skipped the first time around
2230   if (!parse_time) {
2231     _late_inlines_pos = _late_inlines.length();
2232   }
2233 
2234   while (_string_late_inlines.length() > 0) {
2235     CallGenerator* cg = _string_late_inlines.pop();
2236     cg->do_late_inline();
2237     if (failing())  return;
2238   }
2239   _string_late_inlines.trunc_to(0);
2240 }
2241 
2242 // Late inlining of boxing methods
2243 void Compile::inline_boxing_calls(PhaseIterGVN& igvn) {
2244   if (_boxing_late_inlines.length() > 0) {
2245     assert(has_boxed_value(), "inconsistent");
2246 
2247     PhaseGVN* gvn = initial_gvn();
2248     set_inlining_incrementally(true);
2249 
2250     assert( igvn._worklist.size() == 0, "should be done with igvn" );
2251     for_igvn()->clear();
2252     gvn->replace_with(&igvn);
2253 
2254     _late_inlines_pos = _late_inlines.length();
2255 
2256     while (_boxing_late_inlines.length() > 0) {
2257       CallGenerator* cg = _boxing_late_inlines.pop();
2258       cg->do_late_inline();
2259       if (failing())  return;
2260     }
2261     _boxing_late_inlines.trunc_to(0);
2262 
2263     inline_incrementally_cleanup(igvn);
2264 
2265     set_inlining_incrementally(false);
2266   }
2267 }
2268 
2269 bool Compile::inline_incrementally_one() {
2270   assert(IncrementalInline, "incremental inlining should be on");
2271 
2272   TracePhase tp("incrementalInline_inline", &timers[_t_incrInline_inline]);
2273   set_inlining_progress(false);
2274   set_do_cleanup(false);
2275   int i = 0;
2276   for (; i <_late_inlines.length() && !inlining_progress(); i++) {
2277     CallGenerator* cg = _late_inlines.at(i);
2278     _late_inlines_pos = i+1;
2279     cg->do_late_inline();
2280     if (failing())  return false;
2281   }
2282   int j = 0;
2283   for (; i < _late_inlines.length(); i++, j++) {
2284     _late_inlines.at_put(j, _late_inlines.at(i));
2285   }
2286   _late_inlines.trunc_to(j);
2287   assert(inlining_progress() || _late_inlines.length() == 0, "");
2288 
2289   bool needs_cleanup = do_cleanup() || over_inlining_cutoff();
2290 
2291   set_inlining_progress(false);
2292   set_do_cleanup(false);
2293   return (_late_inlines.length() > 0) && !needs_cleanup;
2294 }
2295 
2296 void Compile::inline_incrementally_cleanup(PhaseIterGVN& igvn) {
2297   {
2298     TracePhase tp("incrementalInline_pru", &timers[_t_incrInline_pru]);
2299     ResourceMark rm;
2300     PhaseRemoveUseless pru(initial_gvn(), for_igvn());
2301   }
2302   {
2303     TracePhase tp("incrementalInline_igvn", &timers[_t_incrInline_igvn]);
2304     igvn = PhaseIterGVN(initial_gvn());
2305     igvn.optimize();
2306   }
2307 }
2308 
2309 // Perform incremental inlining until bound on number of live nodes is reached
2310 void Compile::inline_incrementally(PhaseIterGVN& igvn) {
2311   TracePhase tp("incrementalInline", &timers[_t_incrInline]);
2312 
2313   set_inlining_incrementally(true);
2314   uint low_live_nodes = 0;
2315 
2316   while (_late_inlines.length() > 0) {
2317     if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2318       if (low_live_nodes < (uint)LiveNodeCountInliningCutoff * 8 / 10) {
2319         TracePhase tp("incrementalInline_ideal", &timers[_t_incrInline_ideal]);
2320         // PhaseIdealLoop is expensive so we only try it once we are
2321         // out of live nodes and we only try it again if the previous
2322         // helped got the number of nodes down significantly
2323         PhaseIdealLoop::optimize(igvn, LoopOptsNone);
2324         if (failing())  return;
2325         low_live_nodes = live_nodes();
2326         _major_progress = true;
2327       }
2328 
2329       if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2330         break; // finish
2331       }
2332     }
2333 
2334     for_igvn()->clear();
2335     initial_gvn()->replace_with(&igvn);
2336 
2337     while (inline_incrementally_one()) {
2338       assert(!failing(), "inconsistent");
2339     }
2340 
2341     if (failing())  return;
2342 
2343     inline_incrementally_cleanup(igvn);
2344 
2345     if (failing())  return;
2346   }
2347   assert( igvn._worklist.size() == 0, "should be done with igvn" );
2348 
2349   if (_string_late_inlines.length() > 0) {
2350     assert(has_stringbuilder(), "inconsistent");
2351     for_igvn()->clear();
2352     initial_gvn()->replace_with(&igvn);
2353 
2354     inline_string_calls(false);
2355 
2356     if (failing())  return;
2357 
2358     inline_incrementally_cleanup(igvn);
2359   }
2360 
2361   set_inlining_incrementally(false);
2362 }
2363 
2364 
2365 bool Compile::optimize_loops(PhaseIterGVN& igvn, LoopOptsMode mode) {
2366   if(_loop_opts_cnt > 0) {
2367     debug_only( int cnt = 0; );
2368     while(major_progress() && (_loop_opts_cnt > 0)) {
2369       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2370       assert( cnt++ < 40, "infinite cycle in loop optimization" );
2371       PhaseIdealLoop::optimize(igvn, mode);
2372       _loop_opts_cnt--;
2373       if (failing())  return false;
2374       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
2375     }
2376   }
2377   return true;
2378 }
2379 
2380 // Remove edges from "root" to each SafePoint at a backward branch.
2381 // They were inserted during parsing (see add_safepoint()) to make
2382 // infinite loops without calls or exceptions visible to root, i.e.,
2383 // useful.
2384 void Compile::remove_root_to_sfpts_edges(PhaseIterGVN& igvn) {
2385   Node *r = root();
2386   if (r != NULL) {
2387     for (uint i = r->req(); i < r->len(); ++i) {
2388       Node *n = r->in(i);
2389       if (n != NULL && n->is_SafePoint()) {
2390         r->rm_prec(i);
2391         if (n->outcnt() == 0) {
2392           igvn.remove_dead_node(n);
2393         }
2394         --i;
2395       }
2396     }
2397     // Parsing may have added top inputs to the root node (Path
2398     // leading to the Halt node proven dead). Make sure we get a
2399     // chance to clean them up.
2400     igvn._worklist.push(r);
2401     igvn.optimize();
2402   }
2403 }
2404 
2405 //------------------------------Optimize---------------------------------------
2406 // Given a graph, optimize it.
2407 void Compile::Optimize() {
2408   TracePhase tp("optimizer", &timers[_t_optimizer]);
2409 
2410 #ifndef PRODUCT
2411   if (_directive->BreakAtCompileOption) {
2412     BREAKPOINT;
2413   }
2414 
2415 #endif
2416 
2417   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
2418 #ifdef ASSERT
2419   bs->verify_gc_barriers(this, BarrierSetC2::BeforeOptimize);
2420 #endif
2421 
2422   ResourceMark rm;
2423 
2424   print_inlining_reinit();
2425 
2426   NOT_PRODUCT( verify_graph_edges(); )
2427 
2428   print_method(PHASE_AFTER_PARSING);
2429 
2430  {
2431   // Iterative Global Value Numbering, including ideal transforms
2432   // Initialize IterGVN with types and values from parse-time GVN
2433   PhaseIterGVN igvn(initial_gvn());
2434 #ifdef ASSERT
2435   _modified_nodes = new (comp_arena()) Unique_Node_List(comp_arena());
2436 #endif
2437   {
2438     TracePhase tp("iterGVN", &timers[_t_iterGVN]);
2439     igvn.optimize();
2440   }
2441 
2442   if (failing())  return;
2443 
2444   print_method(PHASE_ITER_GVN1, 2);
2445 
2446   inline_incrementally(igvn);
2447 
2448   print_method(PHASE_INCREMENTAL_INLINE, 2);
2449 
2450   if (failing())  return;
2451 
2452   if (eliminate_boxing()) {
2453     // Inline valueOf() methods now.
2454     inline_boxing_calls(igvn);
2455 
2456     if (AlwaysIncrementalInline) {
2457       inline_incrementally(igvn);
2458     }
2459 
2460     print_method(PHASE_INCREMENTAL_BOXING_INLINE, 2);
2461 
2462     if (failing())  return;
2463   }
2464 
2465   // Now that all inlining is over, cut edge from root to loop
2466   // safepoints
2467   remove_root_to_sfpts_edges(igvn);
2468 
2469   // Remove the speculative part of types and clean up the graph from
2470   // the extra CastPP nodes whose only purpose is to carry them. Do
2471   // that early so that optimizations are not disrupted by the extra
2472   // CastPP nodes.
2473   remove_speculative_types(igvn);
2474 
2475   // No more new expensive nodes will be added to the list from here
2476   // so keep only the actual candidates for optimizations.
2477   cleanup_expensive_nodes(igvn);
2478 
2479   if (!failing() && RenumberLiveNodes && live_nodes() + NodeLimitFudgeFactor < unique()) {
2480     Compile::TracePhase tp("", &timers[_t_renumberLive]);
2481     initial_gvn()->replace_with(&igvn);
2482     for_igvn()->clear();
2483     Unique_Node_List new_worklist(C->comp_arena());
2484     {
2485       ResourceMark rm;
2486       PhaseRenumberLive prl = PhaseRenumberLive(initial_gvn(), for_igvn(), &new_worklist);
2487     }
2488     set_for_igvn(&new_worklist);
2489     igvn = PhaseIterGVN(initial_gvn());
2490     igvn.optimize();
2491   }
2492 
2493   if (_inline_type_nodes->length() > 0) {
2494     // Do this once all inlining is over to avoid getting inconsistent debug info
2495     process_inline_types(igvn);
2496   }
2497 
2498   adjust_flattened_array_access_aliases(igvn);
2499 
2500   // Perform escape analysis
2501   if (_do_escape_analysis && ConnectionGraph::has_candidates(this)) {
2502     if (has_loops()) {
2503       // Cleanup graph (remove dead nodes).
2504       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2505       PhaseIdealLoop::optimize(igvn, LoopOptsMaxUnroll);
2506       if (major_progress()) print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
2507       if (failing())  return;
2508     }
2509     ConnectionGraph::do_analysis(this, &igvn);
2510 
2511     if (failing())  return;
2512 
2513     // Optimize out fields loads from scalar replaceable allocations.
2514     igvn.optimize();
2515     print_method(PHASE_ITER_GVN_AFTER_EA, 2);
2516 
2517     if (failing())  return;
2518 
2519     if (congraph() != NULL && macro_count() > 0) {
2520       TracePhase tp("macroEliminate", &timers[_t_macroEliminate]);
2521       PhaseMacroExpand mexp(igvn);
2522       mexp.eliminate_macro_nodes();
2523       igvn.set_delay_transform(false);
2524 
2525       igvn.optimize();
2526       print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
2527 
2528       if (failing())  return;
2529     }
2530   }
2531 
2532   if (_inline_type_nodes->length() > 0) {
2533     // Process inline types again now that EA might have simplified the graph
2534     process_inline_types(igvn, /* post_ea= */ true);
2535   }
2536 
2537   // Loop transforms on the ideal graph.  Range Check Elimination,
2538   // peeling, unrolling, etc.
2539 
2540   // Set loop opts counter
2541   if((_loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
2542     {
2543       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2544       PhaseIdealLoop::optimize(igvn, LoopOptsDefault);
2545       _loop_opts_cnt--;
2546       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP1, 2);
2547       if (failing())  return;
2548     }
2549     // Loop opts pass if partial peeling occurred in previous pass
2550     if(PartialPeelLoop && major_progress() && (_loop_opts_cnt > 0)) {
2551       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2552       PhaseIdealLoop::optimize(igvn, LoopOptsSkipSplitIf);
2553       _loop_opts_cnt--;
2554       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP2, 2);
2555       if (failing())  return;
2556     }
2557     // Loop opts pass for loop-unrolling before CCP
2558     if(major_progress() && (_loop_opts_cnt > 0)) {
2559       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2560       PhaseIdealLoop::optimize(igvn, LoopOptsSkipSplitIf);
2561       _loop_opts_cnt--;
2562       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP3, 2);
2563     }
2564     if (!failing()) {
2565       // Verify that last round of loop opts produced a valid graph
2566       TracePhase tp("idealLoopVerify", &timers[_t_idealLoopVerify]);
2567       PhaseIdealLoop::verify(igvn);
2568     }
2569   }
2570   if (failing())  return;
2571 
2572   // Conditional Constant Propagation;
2573   PhaseCCP ccp( &igvn );
2574   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
2575   {
2576     TracePhase tp("ccp", &timers[_t_ccp]);
2577     ccp.do_transform();
2578   }
2579   print_method(PHASE_CPP1, 2);
2580 
2581   assert( true, "Break here to ccp.dump_old2new_map()");
2582 
2583   // Iterative Global Value Numbering, including ideal transforms
2584   {
2585     TracePhase tp("iterGVN2", &timers[_t_iterGVN2]);
2586     igvn = ccp;
2587     igvn.optimize();
2588   }
2589   print_method(PHASE_ITER_GVN2, 2);
2590 
2591   if (failing())  return;
2592 
2593   // Loop transforms on the ideal graph.  Range Check Elimination,
2594   // peeling, unrolling, etc.
2595   if (!optimize_loops(igvn, LoopOptsDefault)) {
2596     return;
2597   }
2598 
2599   if (failing())  return;
2600 
2601   // Ensure that major progress is now clear
2602   C->clear_major_progress();
2603 
2604   {
2605     // Verify that all previous optimizations produced a valid graph
2606     // at least to this point, even if no loop optimizations were done.
2607     TracePhase tp("idealLoopVerify", &timers[_t_idealLoopVerify]);
2608     PhaseIdealLoop::verify(igvn);
2609   }
2610 
2611   if (range_check_cast_count() > 0) {
2612     // No more loop optimizations. Remove all range check dependent CastIINodes.
2613     C->remove_range_check_casts(igvn);
2614     igvn.optimize();
2615   }
2616 
2617 #ifdef ASSERT
2618   bs->verify_gc_barriers(this, BarrierSetC2::BeforeMacroExpand);
2619 #endif
2620 
2621   {
2622     TracePhase tp("macroExpand", &timers[_t_macroExpand]);
2623     PhaseMacroExpand  mex(igvn);
2624     if (mex.expand_macro_nodes()) {
2625       assert(failing(), "must bail out w/ explicit message");
2626       return;
2627     }
2628     print_method(PHASE_MACRO_EXPANSION, 2);
2629   }
2630 
2631   {
2632     TracePhase tp("barrierExpand", &timers[_t_barrierExpand]);
2633     if (bs->expand_barriers(this, igvn)) {
2634       assert(failing(), "must bail out w/ explicit message");
2635       return;
2636     }
2637     print_method(PHASE_BARRIER_EXPANSION, 2);
2638   }
2639 
2640   if (opaque4_count() > 0) {
2641     C->remove_opaque4_nodes(igvn);
2642     igvn.optimize();
2643   }
2644 
2645   if (C->max_vector_size() > 0) {
2646     C->optimize_logic_cones(igvn);
2647     igvn.optimize();
2648   }
2649 
2650   DEBUG_ONLY( _modified_nodes = NULL; )
2651  } // (End scope of igvn; run destructor if necessary for asserts.)
2652 
2653  process_print_inlining();
2654  // A method with only infinite loops has no edges entering loops from root
2655  {
2656    TracePhase tp("graphReshape", &timers[_t_graphReshaping]);
2657    if (final_graph_reshaping()) {
2658      assert(failing(), "must bail out w/ explicit message");
2659      return;
2660    }
2661  }
2662 
2663  print_method(PHASE_OPTIMIZE_FINISHED, 2);
2664  DEBUG_ONLY(set_phase_optimize_finished();)
2665 }
2666 
2667 //---------------------------- Bitwise operation packing optimization ---------------------------
2668 
2669 static bool is_vector_unary_bitwise_op(Node* n) {
2670   return n->Opcode() == Op_XorV &&
2671          VectorNode::is_vector_bitwise_not_pattern(n);
2672 }
2673 
2674 static bool is_vector_binary_bitwise_op(Node* n) {
2675   switch (n->Opcode()) {
2676     case Op_AndV:
2677     case Op_OrV:
2678       return true;
2679 
2680     case Op_XorV:
2681       return !is_vector_unary_bitwise_op(n);
2682 
2683     default:
2684       return false;
2685   }
2686 }
2687 
2688 static bool is_vector_ternary_bitwise_op(Node* n) {
2689   return n->Opcode() == Op_MacroLogicV;
2690 }
2691 
2692 static bool is_vector_bitwise_op(Node* n) {
2693   return is_vector_unary_bitwise_op(n)  ||
2694          is_vector_binary_bitwise_op(n) ||
2695          is_vector_ternary_bitwise_op(n);
2696 }
2697 
2698 static bool is_vector_bitwise_cone_root(Node* n) {
2699   if (!is_vector_bitwise_op(n)) {
2700     return false;
2701   }
2702   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2703     if (is_vector_bitwise_op(n->fast_out(i))) {
2704       return false;
2705     }
2706   }
2707   return true;
2708 }
2709 
2710 static uint collect_unique_inputs(Node* n, Unique_Node_List& partition, Unique_Node_List& inputs) {
2711   uint cnt = 0;
2712   if (is_vector_bitwise_op(n)) {
2713     if (VectorNode::is_vector_bitwise_not_pattern(n)) {
2714       for (uint i = 1; i < n->req(); i++) {
2715         Node* in = n->in(i);
2716         bool skip = VectorNode::is_all_ones_vector(in);
2717         if (!skip && !inputs.member(in)) {
2718           inputs.push(in);
2719           cnt++;
2720         }
2721       }
2722       assert(cnt <= 1, "not unary");
2723     } else {
2724       uint last_req = n->req();
2725       if (is_vector_ternary_bitwise_op(n)) {
2726         last_req = n->req() - 1; // skip last input
2727       }
2728       for (uint i = 1; i < last_req; i++) {
2729         Node* def = n->in(i);
2730         if (!inputs.member(def)) {
2731           inputs.push(def);
2732           cnt++;
2733         }
2734       }
2735     }
2736     partition.push(n);
2737   } else { // not a bitwise operations
2738     if (!inputs.member(n)) {
2739       inputs.push(n);
2740       cnt++;
2741     }
2742   }
2743   return cnt;
2744 }
2745 
2746 void Compile::collect_logic_cone_roots(Unique_Node_List& list) {
2747   Unique_Node_List useful_nodes;
2748   C->identify_useful_nodes(useful_nodes);
2749 
2750   for (uint i = 0; i < useful_nodes.size(); i++) {
2751     Node* n = useful_nodes.at(i);
2752     if (is_vector_bitwise_cone_root(n)) {
2753       list.push(n);
2754     }
2755   }
2756 }
2757 
2758 Node* Compile::xform_to_MacroLogicV(PhaseIterGVN& igvn,
2759                                     const TypeVect* vt,
2760                                     Unique_Node_List& partition,
2761                                     Unique_Node_List& inputs) {
2762   assert(partition.size() == 2 || partition.size() == 3, "not supported");
2763   assert(inputs.size()    == 2 || inputs.size()    == 3, "not supported");
2764   assert(Matcher::match_rule_supported_vector(Op_MacroLogicV, vt->length(), vt->element_basic_type()), "not supported");
2765 
2766   Node* in1 = inputs.at(0);
2767   Node* in2 = inputs.at(1);
2768   Node* in3 = (inputs.size() == 3 ? inputs.at(2) : in2);
2769 
2770   uint func = compute_truth_table(partition, inputs);
2771   return igvn.transform(MacroLogicVNode::make(igvn, in3, in2, in1, func, vt));
2772 }
2773 
2774 static uint extract_bit(uint func, uint pos) {
2775   return (func & (1 << pos)) >> pos;
2776 }
2777 
2778 //
2779 //  A macro logic node represents a truth table. It has 4 inputs,
2780 //  First three inputs corresponds to 3 columns of a truth table
2781 //  and fourth input captures the logic function.
2782 //
2783 //  eg.  fn = (in1 AND in2) OR in3;
2784 //
2785 //      MacroNode(in1,in2,in3,fn)
2786 //
2787 //  -----------------
2788 //  in1 in2 in3  fn
2789 //  -----------------
2790 //  0    0   0    0
2791 //  0    0   1    1
2792 //  0    1   0    0
2793 //  0    1   1    1
2794 //  1    0   0    0
2795 //  1    0   1    1
2796 //  1    1   0    1
2797 //  1    1   1    1
2798 //
2799 
2800 uint Compile::eval_macro_logic_op(uint func, uint in1 , uint in2, uint in3) {
2801   int res = 0;
2802   for (int i = 0; i < 8; i++) {
2803     int bit1 = extract_bit(in1, i);
2804     int bit2 = extract_bit(in2, i);
2805     int bit3 = extract_bit(in3, i);
2806 
2807     int func_bit_pos = (bit1 << 2 | bit2 << 1 | bit3);
2808     int func_bit = extract_bit(func, func_bit_pos);
2809 
2810     res |= func_bit << i;
2811   }
2812   return res;
2813 }
2814 
2815 static uint eval_operand(Node* n, ResourceHashtable<Node*,uint>& eval_map) {
2816   assert(n != NULL, "");
2817   assert(eval_map.contains(n), "absent");
2818   return *(eval_map.get(n));
2819 }
2820 
2821 static void eval_operands(Node* n,
2822                           uint& func1, uint& func2, uint& func3,
2823                           ResourceHashtable<Node*,uint>& eval_map) {
2824   assert(is_vector_bitwise_op(n), "");
2825   func1 = eval_operand(n->in(1), eval_map);
2826 
2827   if (is_vector_binary_bitwise_op(n)) {
2828     func2 = eval_operand(n->in(2), eval_map);
2829   } else if (is_vector_ternary_bitwise_op(n)) {
2830     func2 = eval_operand(n->in(2), eval_map);
2831     func3 = eval_operand(n->in(3), eval_map);
2832   } else {
2833     assert(is_vector_unary_bitwise_op(n), "not unary");
2834   }
2835 }
2836 
2837 uint Compile::compute_truth_table(Unique_Node_List& partition, Unique_Node_List& inputs) {
2838   assert(inputs.size() <= 3, "sanity");
2839   ResourceMark rm;
2840   uint res = 0;
2841   ResourceHashtable<Node*,uint> eval_map;
2842 
2843   // Populate precomputed functions for inputs.
2844   // Each input corresponds to one column of 3 input truth-table.
2845   uint input_funcs[] = { 0xAA,   // (_, _, a) -> a
2846                          0xCC,   // (_, b, _) -> b
2847                          0xF0 }; // (c, _, _) -> c
2848   for (uint i = 0; i < inputs.size(); i++) {
2849     eval_map.put(inputs.at(i), input_funcs[i]);
2850   }
2851 
2852   for (uint i = 0; i < partition.size(); i++) {
2853     Node* n = partition.at(i);
2854 
2855     uint func1 = 0, func2 = 0, func3 = 0;
2856     eval_operands(n, func1, func2, func3, eval_map);
2857 
2858     switch (n->Opcode()) {
2859       case Op_OrV:
2860         assert(func3 == 0, "not binary");
2861         res = func1 | func2;
2862         break;
2863       case Op_AndV:
2864         assert(func3 == 0, "not binary");
2865         res = func1 & func2;
2866         break;
2867       case Op_XorV:
2868         if (VectorNode::is_vector_bitwise_not_pattern(n)) {
2869           assert(func2 == 0 && func3 == 0, "not unary");
2870           res = (~func1) & 0xFF;
2871         } else {
2872           assert(func3 == 0, "not binary");
2873           res = func1 ^ func2;
2874         }
2875         break;
2876       case Op_MacroLogicV:
2877         // Ordering of inputs may change during evaluation of sub-tree
2878         // containing MacroLogic node as a child node, thus a re-evaluation
2879         // makes sure that function is evaluated in context of current
2880         // inputs.
2881         res = eval_macro_logic_op(n->in(4)->get_int(), func1, func2, func3);
2882         break;
2883 
2884       default: assert(false, "not supported: %s", n->Name());
2885     }
2886     assert(res <= 0xFF, "invalid");
2887     eval_map.put(n, res);
2888   }
2889   return res;
2890 }
2891 
2892 bool Compile::compute_logic_cone(Node* n, Unique_Node_List& partition, Unique_Node_List& inputs) {
2893   assert(partition.size() == 0, "not empty");
2894   assert(inputs.size() == 0, "not empty");
2895   if (is_vector_ternary_bitwise_op(n)) {
2896     return false;
2897   }
2898 
2899   bool is_unary_op = is_vector_unary_bitwise_op(n);
2900   if (is_unary_op) {
2901     assert(collect_unique_inputs(n, partition, inputs) == 1, "not unary");
2902     return false; // too few inputs
2903   }
2904 
2905   assert(is_vector_binary_bitwise_op(n), "not binary");
2906   Node* in1 = n->in(1);
2907   Node* in2 = n->in(2);
2908 
2909   int in1_unique_inputs_cnt = collect_unique_inputs(in1, partition, inputs);
2910   int in2_unique_inputs_cnt = collect_unique_inputs(in2, partition, inputs);
2911   partition.push(n);
2912 
2913   // Too many inputs?
2914   if (inputs.size() > 3) {
2915     partition.clear();
2916     inputs.clear();
2917     { // Recompute in2 inputs
2918       Unique_Node_List not_used;
2919       in2_unique_inputs_cnt = collect_unique_inputs(in2, not_used, not_used);
2920     }
2921     // Pick the node with minimum number of inputs.
2922     if (in1_unique_inputs_cnt >= 3 && in2_unique_inputs_cnt >= 3) {
2923       return false; // still too many inputs
2924     }
2925     // Recompute partition & inputs.
2926     Node* child       = (in1_unique_inputs_cnt < in2_unique_inputs_cnt ? in1 : in2);
2927     collect_unique_inputs(child, partition, inputs);
2928 
2929     Node* other_input = (in1_unique_inputs_cnt < in2_unique_inputs_cnt ? in2 : in1);
2930     inputs.push(other_input);
2931 
2932     partition.push(n);
2933   }
2934 
2935   return (partition.size() == 2 || partition.size() == 3) &&
2936          (inputs.size()    == 2 || inputs.size()    == 3);
2937 }
2938 
2939 
2940 void Compile::process_logic_cone_root(PhaseIterGVN &igvn, Node *n, VectorSet &visited) {
2941   assert(is_vector_bitwise_op(n), "not a root");
2942 
2943   visited.set(n->_idx);
2944 
2945   // 1) Do a DFS walk over the logic cone.
2946   for (uint i = 1; i < n->req(); i++) {
2947     Node* in = n->in(i);
2948     if (!visited.test(in->_idx) && is_vector_bitwise_op(in)) {
2949       process_logic_cone_root(igvn, in, visited);
2950     }
2951   }
2952 
2953   // 2) Bottom up traversal: Merge node[s] with
2954   // the parent to form macro logic node.
2955   Unique_Node_List partition;
2956   Unique_Node_List inputs;
2957   if (compute_logic_cone(n, partition, inputs)) {
2958     const TypeVect* vt = n->bottom_type()->is_vect();
2959     Node* macro_logic = xform_to_MacroLogicV(igvn, vt, partition, inputs);
2960     igvn.replace_node(n, macro_logic);
2961   }
2962 }
2963 
2964 void Compile::optimize_logic_cones(PhaseIterGVN &igvn) {
2965   ResourceMark rm;
2966   if (Matcher::match_rule_supported(Op_MacroLogicV)) {
2967     Unique_Node_List list;
2968     collect_logic_cone_roots(list);
2969 
2970     while (list.size() > 0) {
2971       Node* n = list.pop();
2972       const TypeVect* vt = n->bottom_type()->is_vect();
2973       bool supported = Matcher::match_rule_supported_vector(Op_MacroLogicV, vt->length(), vt->element_basic_type());
2974       if (supported) {
2975         VectorSet visited(comp_arena());
2976         process_logic_cone_root(igvn, n, visited);
2977       }
2978     }
2979   }
2980 }
2981 
2982 //------------------------------Code_Gen---------------------------------------
2983 // Given a graph, generate code for it
2984 void Compile::Code_Gen() {
2985   if (failing()) {
2986     return;
2987   }
2988 
2989   // Perform instruction selection.  You might think we could reclaim Matcher
2990   // memory PDQ, but actually the Matcher is used in generating spill code.
2991   // Internals of the Matcher (including some VectorSets) must remain live
2992   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
2993   // set a bit in reclaimed memory.
2994 
2995   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2996   // nodes.  Mapping is only valid at the root of each matched subtree.
2997   NOT_PRODUCT( verify_graph_edges(); )
2998 
2999   Matcher matcher;
3000   _matcher = &matcher;
3001   {
3002     TracePhase tp("matcher", &timers[_t_matcher]);
3003     matcher.match();
3004     if (failing()) {
3005       return;
3006     }
3007   }
3008 
3009   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
3010   // nodes.  Mapping is only valid at the root of each matched subtree.
3011   NOT_PRODUCT( verify_graph_edges(); )
3012 
3013   // If you have too many nodes, or if matching has failed, bail out
3014   check_node_count(0, "out of nodes matching instructions");
3015   if (failing()) {
3016     return;
3017   }
3018 
3019   print_method(PHASE_MATCHING, 2);
3020 
3021   // Build a proper-looking CFG
3022   PhaseCFG cfg(node_arena(), root(), matcher);
3023   _cfg = &cfg;
3024   {
3025     TracePhase tp("scheduler", &timers[_t_scheduler]);
3026     bool success = cfg.do_global_code_motion();
3027     if (!success) {
3028       return;
3029     }
3030 
3031     print_method(PHASE_GLOBAL_CODE_MOTION, 2);
3032     NOT_PRODUCT( verify_graph_edges(); )
3033     debug_only( cfg.verify(); )
3034   }
3035 
3036   PhaseChaitin regalloc(unique(), cfg, matcher, false);
3037   _regalloc = &regalloc;
3038   {
3039     TracePhase tp("regalloc", &timers[_t_registerAllocation]);
3040     // Perform register allocation.  After Chaitin, use-def chains are
3041     // no longer accurate (at spill code) and so must be ignored.
3042     // Node->LRG->reg mappings are still accurate.
3043     _regalloc->Register_Allocate();
3044 
3045     // Bail out if the allocator builds too many nodes
3046     if (failing()) {
3047       return;
3048     }
3049   }
3050 
3051   // Prior to register allocation we kept empty basic blocks in case the
3052   // the allocator needed a place to spill.  After register allocation we
3053   // are not adding any new instructions.  If any basic block is empty, we
3054   // can now safely remove it.
3055   {
3056     TracePhase tp("blockOrdering", &timers[_t_blockOrdering]);
3057     cfg.remove_empty_blocks();
3058     if (do_freq_based_layout()) {
3059       PhaseBlockLayout layout(cfg);
3060     } else {
3061       cfg.set_loop_alignment();
3062     }
3063     cfg.fixup_flow();
3064   }
3065 
3066   // Apply peephole optimizations
3067   if( OptoPeephole ) {
3068     TracePhase tp("peephole", &timers[_t_peephole]);
3069     PhasePeephole peep( _regalloc, cfg);
3070     peep.do_transform();
3071   }
3072 
3073   // Do late expand if CPU requires this.
3074   if (Matcher::require_postalloc_expand) {
3075     TracePhase tp("postalloc_expand", &timers[_t_postalloc_expand]);
3076     cfg.postalloc_expand(_regalloc);
3077   }
3078 
3079   // Convert Nodes to instruction bits in a buffer
3080   {
3081     TracePhase tp("output", &timers[_t_output]);
3082     PhaseOutput output;
3083     output.Output();
3084     if (failing())  return;
3085     output.install();
3086   }
3087 
3088   print_method(PHASE_FINAL_CODE);
3089 
3090   // He's dead, Jim.
3091   _cfg     = (PhaseCFG*)((intptr_t)0xdeadbeef);
3092   _regalloc = (PhaseChaitin*)((intptr_t)0xdeadbeef);
3093 }
3094 
3095 //------------------------------Final_Reshape_Counts---------------------------
3096 // This class defines counters to help identify when a method
3097 // may/must be executed using hardware with only 24-bit precision.
3098 struct Final_Reshape_Counts : public StackObj {
3099   int  _call_count;             // count non-inlined 'common' calls
3100   int  _float_count;            // count float ops requiring 24-bit precision
3101   int  _double_count;           // count double ops requiring more precision
3102   int  _java_call_count;        // count non-inlined 'java' calls
3103   int  _inner_loop_count;       // count loops which need alignment
3104   VectorSet _visited;           // Visitation flags
3105   Node_List _tests;             // Set of IfNodes & PCTableNodes
3106 
3107   Final_Reshape_Counts() :
3108     _call_count(0), _float_count(0), _double_count(0),
3109     _java_call_count(0), _inner_loop_count(0) { }
3110 
3111   void inc_call_count  () { _call_count  ++; }
3112   void inc_float_count () { _float_count ++; }
3113   void inc_double_count() { _double_count++; }
3114   void inc_java_call_count() { _java_call_count++; }
3115   void inc_inner_loop_count() { _inner_loop_count++; }
3116 
3117   int  get_call_count  () const { return _call_count  ; }
3118   int  get_float_count () const { return _float_count ; }
3119   int  get_double_count() const { return _double_count; }
3120   int  get_java_call_count() const { return _java_call_count; }
3121   int  get_inner_loop_count() const { return _inner_loop_count; }
3122 };
3123 
3124 #ifdef ASSERT
3125 static bool oop_offset_is_sane(const TypeInstPtr* tp) {
3126   ciInstanceKlass *k = tp->klass()->as_instance_klass();
3127   // Make sure the offset goes inside the instance layout.
3128   return k->contains_field_offset(tp->offset());
3129   // Note that OffsetBot and OffsetTop are very negative.
3130 }
3131 #endif
3132 
3133 // Eliminate trivially redundant StoreCMs and accumulate their
3134 // precedence edges.
3135 void Compile::eliminate_redundant_card_marks(Node* n) {
3136   assert(n->Opcode() == Op_StoreCM, "expected StoreCM");
3137   if (n->in(MemNode::Address)->outcnt() > 1) {
3138     // There are multiple users of the same address so it might be
3139     // possible to eliminate some of the StoreCMs
3140     Node* mem = n->in(MemNode::Memory);
3141     Node* adr = n->in(MemNode::Address);
3142     Node* val = n->in(MemNode::ValueIn);
3143     Node* prev = n;
3144     bool done = false;
3145     // Walk the chain of StoreCMs eliminating ones that match.  As
3146     // long as it's a chain of single users then the optimization is
3147     // safe.  Eliminating partially redundant StoreCMs would require
3148     // cloning copies down the other paths.
3149     while (mem->Opcode() == Op_StoreCM && mem->outcnt() == 1 && !done) {
3150       if (adr == mem->in(MemNode::Address) &&
3151           val == mem->in(MemNode::ValueIn)) {
3152         // redundant StoreCM
3153         if (mem->req() > MemNode::OopStore) {
3154           // Hasn't been processed by this code yet.
3155           n->add_prec(mem->in(MemNode::OopStore));
3156         } else {
3157           // Already converted to precedence edge
3158           for (uint i = mem->req(); i < mem->len(); i++) {
3159             // Accumulate any precedence edges
3160             if (mem->in(i) != NULL) {
3161               n->add_prec(mem->in(i));
3162             }
3163           }
3164           // Everything above this point has been processed.
3165           done = true;
3166         }
3167         // Eliminate the previous StoreCM
3168         prev->set_req(MemNode::Memory, mem->in(MemNode::Memory));
3169         assert(mem->outcnt() == 0, "should be dead");
3170         mem->disconnect_inputs(NULL, this);
3171       } else {
3172         prev = mem;
3173       }
3174       mem = prev->in(MemNode::Memory);
3175     }
3176   }
3177 }
3178 
3179 
3180 //------------------------------final_graph_reshaping_impl----------------------
3181 // Implement items 1-5 from final_graph_reshaping below.
3182 void Compile::final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &frc) {
3183 
3184   if ( n->outcnt() == 0 ) return; // dead node
3185   uint nop = n->Opcode();
3186 
3187   // Check for 2-input instruction with "last use" on right input.
3188   // Swap to left input.  Implements item (2).
3189   if( n->req() == 3 &&          // two-input instruction
3190       n->in(1)->outcnt() > 1 && // left use is NOT a last use
3191       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
3192       n->in(2)->outcnt() == 1 &&// right use IS a last use
3193       !n->in(2)->is_Con() ) {   // right use is not a constant
3194     // Check for commutative opcode
3195     switch( nop ) {
3196     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddL:
3197     case Op_MaxI:  case Op_MinI:
3198     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulL:
3199     case Op_AndL:  case Op_XorL:  case Op_OrL:
3200     case Op_AndI:  case Op_XorI:  case Op_OrI: {
3201       // Move "last use" input to left by swapping inputs
3202       n->swap_edges(1, 2);
3203       break;
3204     }
3205     default:
3206       break;
3207     }
3208   }
3209 
3210 #ifdef ASSERT
3211   if( n->is_Mem() ) {
3212     int alias_idx = get_alias_index(n->as_Mem()->adr_type());
3213     assert( n->in(0) != NULL || alias_idx != Compile::AliasIdxRaw ||
3214             // oop will be recorded in oop map if load crosses safepoint
3215             n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
3216                              LoadNode::is_immutable_value(n->in(MemNode::Address))),
3217             "raw memory operations should have control edge");
3218   }
3219   if (n->is_MemBar()) {
3220     MemBarNode* mb = n->as_MemBar();
3221     if (mb->trailing_store() || mb->trailing_load_store()) {
3222       assert(mb->leading_membar()->trailing_membar() == mb, "bad membar pair");
3223       Node* mem = BarrierSet::barrier_set()->barrier_set_c2()->step_over_gc_barrier(mb->in(MemBarNode::Precedent));
3224       assert((mb->trailing_store() && mem->is_Store() && mem->as_Store()->is_release()) ||
3225              (mb->trailing_load_store() && mem->is_LoadStore()), "missing mem op");
3226     } else if (mb->leading()) {
3227       assert(mb->trailing_membar()->leading_membar() == mb, "bad membar pair");
3228     }
3229   }
3230 #endif
3231   // Count FPU ops and common calls, implements item (3)
3232   bool gc_handled = BarrierSet::barrier_set()->barrier_set_c2()->final_graph_reshaping(this, n, nop);
3233   if (!gc_handled) {
3234     final_graph_reshaping_main_switch(n, frc, nop);
3235   }
3236 
3237   // Collect CFG split points
3238   if (n->is_MultiBranch() && !n->is_RangeCheck()) {
3239     frc._tests.push(n);
3240   }
3241 }
3242 
3243 void Compile::final_graph_reshaping_main_switch(Node* n, Final_Reshape_Counts& frc, uint nop) {
3244   switch( nop ) {
3245   // Count all float operations that may use FPU
3246   case Op_AddF:
3247   case Op_SubF:
3248   case Op_MulF:
3249   case Op_DivF:
3250   case Op_NegF:
3251   case Op_ModF:
3252   case Op_ConvI2F:
3253   case Op_ConF:
3254   case Op_CmpF:
3255   case Op_CmpF3:
3256   // case Op_ConvL2F: // longs are split into 32-bit halves
3257     frc.inc_float_count();
3258     break;
3259 
3260   case Op_ConvF2D:
3261   case Op_ConvD2F:
3262     frc.inc_float_count();
3263     frc.inc_double_count();
3264     break;
3265 
3266   // Count all double operations that may use FPU
3267   case Op_AddD:
3268   case Op_SubD:
3269   case Op_MulD:
3270   case Op_DivD:
3271   case Op_NegD:
3272   case Op_ModD:
3273   case Op_ConvI2D:
3274   case Op_ConvD2I:
3275   // case Op_ConvL2D: // handled by leaf call
3276   // case Op_ConvD2L: // handled by leaf call
3277   case Op_ConD:
3278   case Op_CmpD:
3279   case Op_CmpD3:
3280     frc.inc_double_count();
3281     break;
3282   case Op_Opaque1:              // Remove Opaque Nodes before matching
3283   case Op_Opaque2:              // Remove Opaque Nodes before matching
3284   case Op_Opaque3:
3285     n->subsume_by(n->in(1), this);
3286     break;
3287   case Op_CallStaticJava:
3288   case Op_CallJava:
3289   case Op_CallDynamicJava:
3290     frc.inc_java_call_count(); // Count java call site;
3291   case Op_CallRuntime:
3292   case Op_CallLeaf:
3293   case Op_CallLeafNoFP: {
3294     assert (n->is_Call(), "");
3295     CallNode *call = n->as_Call();
3296     // Count call sites where the FP mode bit would have to be flipped.
3297     // Do not count uncommon runtime calls:
3298     // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
3299     // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
3300     if (!call->is_CallStaticJava() || !call->as_CallStaticJava()->_name) {
3301       frc.inc_call_count();   // Count the call site
3302     } else {                  // See if uncommon argument is shared
3303       Node *n = call->in(TypeFunc::Parms);
3304       int nop = n->Opcode();
3305       // Clone shared simple arguments to uncommon calls, item (1).
3306       if (n->outcnt() > 1 &&
3307           !n->is_Proj() &&
3308           nop != Op_CreateEx &&
3309           nop != Op_CheckCastPP &&
3310           nop != Op_DecodeN &&
3311           nop != Op_DecodeNKlass &&
3312           !n->is_Mem() &&
3313           !n->is_Phi()) {
3314         Node *x = n->clone();
3315         call->set_req(TypeFunc::Parms, x);
3316       }
3317     }
3318     break;
3319   }
3320 
3321   case Op_StoreD:
3322   case Op_LoadD:
3323   case Op_LoadD_unaligned:
3324     frc.inc_double_count();
3325     goto handle_mem;
3326   case Op_StoreF:
3327   case Op_LoadF:
3328     frc.inc_float_count();
3329     goto handle_mem;
3330 
3331   case Op_StoreCM:
3332     {
3333       // Convert OopStore dependence into precedence edge
3334       Node* prec = n->in(MemNode::OopStore);
3335       n->del_req(MemNode::OopStore);
3336       n->add_prec(prec);
3337       eliminate_redundant_card_marks(n);
3338     }
3339 
3340     // fall through
3341 
3342   case Op_StoreB:
3343   case Op_StoreC:
3344   case Op_StorePConditional:
3345   case Op_StoreI:
3346   case Op_StoreL:
3347   case Op_StoreIConditional:
3348   case Op_StoreLConditional:
3349   case Op_CompareAndSwapB:
3350   case Op_CompareAndSwapS:
3351   case Op_CompareAndSwapI:
3352   case Op_CompareAndSwapL:
3353   case Op_CompareAndSwapP:
3354   case Op_CompareAndSwapN:
3355   case Op_WeakCompareAndSwapB:
3356   case Op_WeakCompareAndSwapS:
3357   case Op_WeakCompareAndSwapI:
3358   case Op_WeakCompareAndSwapL:
3359   case Op_WeakCompareAndSwapP:
3360   case Op_WeakCompareAndSwapN:
3361   case Op_CompareAndExchangeB:
3362   case Op_CompareAndExchangeS:
3363   case Op_CompareAndExchangeI:
3364   case Op_CompareAndExchangeL:
3365   case Op_CompareAndExchangeP:
3366   case Op_CompareAndExchangeN:
3367   case Op_GetAndAddS:
3368   case Op_GetAndAddB:
3369   case Op_GetAndAddI:
3370   case Op_GetAndAddL:
3371   case Op_GetAndSetS:
3372   case Op_GetAndSetB:
3373   case Op_GetAndSetI:
3374   case Op_GetAndSetL:
3375   case Op_GetAndSetP:
3376   case Op_GetAndSetN:
3377   case Op_StoreP:
3378   case Op_StoreN:
3379   case Op_StoreNKlass:
3380   case Op_LoadB:
3381   case Op_LoadUB:
3382   case Op_LoadUS:
3383   case Op_LoadI:
3384   case Op_LoadKlass:
3385   case Op_LoadNKlass:
3386   case Op_LoadL:
3387   case Op_LoadL_unaligned:
3388   case Op_LoadPLocked:
3389   case Op_LoadP:
3390   case Op_LoadN:
3391   case Op_LoadRange:
3392   case Op_LoadS: {
3393   handle_mem:
3394 #ifdef ASSERT
3395     if( VerifyOptoOopOffsets ) {
3396       MemNode* mem  = n->as_Mem();
3397       // Check to see if address types have grounded out somehow.
3398       const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
3399       assert( !tp || oop_offset_is_sane(tp), "" );
3400     }
3401 #endif
3402     break;
3403   }
3404 
3405   case Op_AddP: {               // Assert sane base pointers
3406     Node *addp = n->in(AddPNode::Address);
3407     assert( !addp->is_AddP() ||
3408             addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
3409             addp->in(AddPNode::Base) == n->in(AddPNode::Base),
3410             "Base pointers must match (addp %u)", addp->_idx );
3411 #ifdef _LP64
3412     if ((UseCompressedOops || UseCompressedClassPointers) &&
3413         addp->Opcode() == Op_ConP &&
3414         addp == n->in(AddPNode::Base) &&
3415         n->in(AddPNode::Offset)->is_Con()) {
3416       // If the transformation of ConP to ConN+DecodeN is beneficial depends
3417       // on the platform and on the compressed oops mode.
3418       // Use addressing with narrow klass to load with offset on x86.
3419       // Some platforms can use the constant pool to load ConP.
3420       // Do this transformation here since IGVN will convert ConN back to ConP.
3421       const Type* t = addp->bottom_type();
3422       bool is_oop   = t->isa_oopptr() != NULL;
3423       bool is_klass = t->isa_klassptr() != NULL;
3424 
3425       if ((is_oop   && Matcher::const_oop_prefer_decode()  ) ||
3426           (is_klass && Matcher::const_klass_prefer_decode())) {
3427         Node* nn = NULL;
3428 
3429         int op = is_oop ? Op_ConN : Op_ConNKlass;
3430 
3431         // Look for existing ConN node of the same exact type.
3432         Node* r  = root();
3433         uint cnt = r->outcnt();
3434         for (uint i = 0; i < cnt; i++) {
3435           Node* m = r->raw_out(i);
3436           if (m!= NULL && m->Opcode() == op &&
3437               m->bottom_type()->make_ptr() == t) {
3438             nn = m;
3439             break;
3440           }
3441         }
3442         if (nn != NULL) {
3443           // Decode a narrow oop to match address
3444           // [R12 + narrow_oop_reg<<3 + offset]
3445           if (is_oop) {
3446             nn = new DecodeNNode(nn, t);
3447           } else {
3448             nn = new DecodeNKlassNode(nn, t);
3449           }
3450           // Check for succeeding AddP which uses the same Base.
3451           // Otherwise we will run into the assertion above when visiting that guy.
3452           for (uint i = 0; i < n->outcnt(); ++i) {
3453             Node *out_i = n->raw_out(i);
3454             if (out_i && out_i->is_AddP() && out_i->in(AddPNode::Base) == addp) {
3455               out_i->set_req(AddPNode::Base, nn);
3456 #ifdef ASSERT
3457               for (uint j = 0; j < out_i->outcnt(); ++j) {
3458                 Node *out_j = out_i->raw_out(j);
3459                 assert(out_j == NULL || !out_j->is_AddP() || out_j->in(AddPNode::Base) != addp,
3460                        "more than 2 AddP nodes in a chain (out_j %u)", out_j->_idx);
3461               }
3462 #endif
3463             }
3464           }
3465           n->set_req(AddPNode::Base, nn);
3466           n->set_req(AddPNode::Address, nn);
3467           if (addp->outcnt() == 0) {
3468             addp->disconnect_inputs(NULL, this);
3469           }
3470         }
3471       }
3472     }
3473 #endif
3474     // platform dependent reshaping of the address expression
3475     reshape_address(n->as_AddP());
3476     break;
3477   }
3478 
3479   case Op_CastPP: {
3480     // Remove CastPP nodes to gain more freedom during scheduling but
3481     // keep the dependency they encode as control or precedence edges
3482     // (if control is set already) on memory operations. Some CastPP
3483     // nodes don't have a control (don't carry a dependency): skip
3484     // those.
3485     if (n->in(0) != NULL) {
3486       ResourceMark rm;
3487       Unique_Node_List wq;
3488       wq.push(n);
3489       for (uint next = 0; next < wq.size(); ++next) {
3490         Node *m = wq.at(next);
3491         for (DUIterator_Fast imax, i = m->fast_outs(imax); i < imax; i++) {
3492           Node* use = m->fast_out(i);
3493           if (use->is_Mem() || use->is_EncodeNarrowPtr()) {
3494             use->ensure_control_or_add_prec(n->in(0));
3495           } else {
3496             switch(use->Opcode()) {
3497             case Op_AddP:
3498             case Op_DecodeN:
3499             case Op_DecodeNKlass:
3500             case Op_CheckCastPP:
3501             case Op_CastPP:
3502               wq.push(use);
3503               break;
3504             }
3505           }
3506         }
3507       }
3508     }
3509     const bool is_LP64 = LP64_ONLY(true) NOT_LP64(false);
3510     if (is_LP64 && n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
3511       Node* in1 = n->in(1);
3512       const Type* t = n->bottom_type();
3513       Node* new_in1 = in1->clone();
3514       new_in1->as_DecodeN()->set_type(t);
3515 
3516       if (!Matcher::narrow_oop_use_complex_address()) {
3517         //
3518         // x86, ARM and friends can handle 2 adds in addressing mode
3519         // and Matcher can fold a DecodeN node into address by using
3520         // a narrow oop directly and do implicit NULL check in address:
3521         //
3522         // [R12 + narrow_oop_reg<<3 + offset]
3523         // NullCheck narrow_oop_reg
3524         //
3525         // On other platforms (Sparc) we have to keep new DecodeN node and
3526         // use it to do implicit NULL check in address:
3527         //
3528         // decode_not_null narrow_oop_reg, base_reg
3529         // [base_reg + offset]
3530         // NullCheck base_reg
3531         //
3532         // Pin the new DecodeN node to non-null path on these platform (Sparc)
3533         // to keep the information to which NULL check the new DecodeN node
3534         // corresponds to use it as value in implicit_null_check().
3535         //
3536         new_in1->set_req(0, n->in(0));
3537       }
3538 
3539       n->subsume_by(new_in1, this);
3540       if (in1->outcnt() == 0) {
3541         in1->disconnect_inputs(NULL, this);
3542       }
3543     } else {
3544       n->subsume_by(n->in(1), this);
3545       if (n->outcnt() == 0) {
3546         n->disconnect_inputs(NULL, this);
3547       }
3548     }
3549     break;
3550   }
3551 #ifdef _LP64
3552   case Op_CmpP:
3553     // Do this transformation here to preserve CmpPNode::sub() and
3554     // other TypePtr related Ideal optimizations (for example, ptr nullness).
3555     if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
3556       Node* in1 = n->in(1);
3557       Node* in2 = n->in(2);
3558       if (!in1->is_DecodeNarrowPtr()) {
3559         in2 = in1;
3560         in1 = n->in(2);
3561       }
3562       assert(in1->is_DecodeNarrowPtr(), "sanity");
3563 
3564       Node* new_in2 = NULL;
3565       if (in2->is_DecodeNarrowPtr()) {
3566         assert(in2->Opcode() == in1->Opcode(), "must be same node type");
3567         new_in2 = in2->in(1);
3568       } else if (in2->Opcode() == Op_ConP) {
3569         const Type* t = in2->bottom_type();
3570         if (t == TypePtr::NULL_PTR) {
3571           assert(in1->is_DecodeN(), "compare klass to null?");
3572           // Don't convert CmpP null check into CmpN if compressed
3573           // oops implicit null check is not generated.
3574           // This will allow to generate normal oop implicit null check.
3575           if (Matcher::gen_narrow_oop_implicit_null_checks())
3576             new_in2 = ConNode::make(TypeNarrowOop::NULL_PTR);
3577           //
3578           // This transformation together with CastPP transformation above
3579           // will generated code for implicit NULL checks for compressed oops.
3580           //
3581           // The original code after Optimize()
3582           //
3583           //    LoadN memory, narrow_oop_reg
3584           //    decode narrow_oop_reg, base_reg
3585           //    CmpP base_reg, NULL
3586           //    CastPP base_reg // NotNull
3587           //    Load [base_reg + offset], val_reg
3588           //
3589           // after these transformations will be
3590           //
3591           //    LoadN memory, narrow_oop_reg
3592           //    CmpN narrow_oop_reg, NULL
3593           //    decode_not_null narrow_oop_reg, base_reg
3594           //    Load [base_reg + offset], val_reg
3595           //
3596           // and the uncommon path (== NULL) will use narrow_oop_reg directly
3597           // since narrow oops can be used in debug info now (see the code in
3598           // final_graph_reshaping_walk()).
3599           //
3600           // At the end the code will be matched to
3601           // on x86:
3602           //
3603           //    Load_narrow_oop memory, narrow_oop_reg
3604           //    Load [R12 + narrow_oop_reg<<3 + offset], val_reg
3605           //    NullCheck narrow_oop_reg
3606           //
3607           // and on sparc:
3608           //
3609           //    Load_narrow_oop memory, narrow_oop_reg
3610           //    decode_not_null narrow_oop_reg, base_reg
3611           //    Load [base_reg + offset], val_reg
3612           //    NullCheck base_reg
3613           //
3614         } else if (t->isa_oopptr()) {
3615           new_in2 = ConNode::make(t->make_narrowoop());
3616         } else if (t->isa_klassptr()) {
3617           new_in2 = ConNode::make(t->make_narrowklass());
3618         }
3619       }
3620       if (new_in2 != NULL) {
3621         Node* cmpN = new CmpNNode(in1->in(1), new_in2);
3622         n->subsume_by(cmpN, this);
3623         if (in1->outcnt() == 0) {
3624           in1->disconnect_inputs(NULL, this);
3625         }
3626         if (in2->outcnt() == 0) {
3627           in2->disconnect_inputs(NULL, this);
3628         }
3629       }
3630     }
3631     break;
3632 
3633   case Op_DecodeN:
3634   case Op_DecodeNKlass:
3635     assert(!n->in(1)->is_EncodeNarrowPtr(), "should be optimized out");
3636     // DecodeN could be pinned when it can't be fold into
3637     // an address expression, see the code for Op_CastPP above.
3638     assert(n->in(0) == NULL || (UseCompressedOops && !Matcher::narrow_oop_use_complex_address()), "no control");
3639     break;
3640 
3641   case Op_EncodeP:
3642   case Op_EncodePKlass: {
3643     Node* in1 = n->in(1);
3644     if (in1->is_DecodeNarrowPtr()) {
3645       n->subsume_by(in1->in(1), this);
3646     } else if (in1->Opcode() == Op_ConP) {
3647       const Type* t = in1->bottom_type();
3648       if (t == TypePtr::NULL_PTR) {
3649         assert(t->isa_oopptr(), "null klass?");
3650         n->subsume_by(ConNode::make(TypeNarrowOop::NULL_PTR), this);
3651       } else if (t->isa_oopptr()) {
3652         n->subsume_by(ConNode::make(t->make_narrowoop()), this);
3653       } else if (t->isa_klassptr()) {
3654         n->subsume_by(ConNode::make(t->make_narrowklass()), this);
3655       }
3656     }
3657     if (in1->outcnt() == 0) {
3658       in1->disconnect_inputs(NULL, this);
3659     }
3660     break;
3661   }
3662 
3663   case Op_Proj: {
3664     if (OptimizeStringConcat) {
3665       ProjNode* p = n->as_Proj();
3666       if (p->_is_io_use) {
3667         // Separate projections were used for the exception path which
3668         // are normally removed by a late inline.  If it wasn't inlined
3669         // then they will hang around and should just be replaced with
3670         // the original one.
3671         Node* proj = NULL;
3672         // Replace with just one
3673         for (SimpleDUIterator i(p->in(0)); i.has_next(); i.next()) {
3674           Node *use = i.get();
3675           if (use->is_Proj() && p != use && use->as_Proj()->_con == p->_con) {
3676             proj = use;
3677             break;
3678           }
3679         }
3680         assert(proj != NULL || p->_con == TypeFunc::I_O, "io may be dropped at an infinite loop");
3681         if (proj != NULL) {
3682           p->subsume_by(proj, this);
3683         }
3684       }
3685     }
3686     break;
3687   }
3688 
3689   case Op_Phi:
3690     if (n->as_Phi()->bottom_type()->isa_narrowoop() || n->as_Phi()->bottom_type()->isa_narrowklass()) {
3691       // The EncodeP optimization may create Phi with the same edges
3692       // for all paths. It is not handled well by Register Allocator.
3693       Node* unique_in = n->in(1);
3694       assert(unique_in != NULL, "");
3695       uint cnt = n->req();
3696       for (uint i = 2; i < cnt; i++) {
3697         Node* m = n->in(i);
3698         assert(m != NULL, "");
3699         if (unique_in != m)
3700           unique_in = NULL;
3701       }
3702       if (unique_in != NULL) {
3703         n->subsume_by(unique_in, this);
3704       }
3705     }
3706     break;
3707 
3708 #endif
3709 
3710 #ifdef ASSERT
3711   case Op_CastII:
3712     // Verify that all range check dependent CastII nodes were removed.
3713     if (n->isa_CastII()->has_range_check()) {
3714       n->dump(3);
3715       assert(false, "Range check dependent CastII node was not removed");
3716     }
3717     break;
3718 #endif
3719 
3720   case Op_ModI:
3721     if (UseDivMod) {
3722       // Check if a%b and a/b both exist
3723       Node* d = n->find_similar(Op_DivI);
3724       if (d) {
3725         // Replace them with a fused divmod if supported
3726         if (Matcher::has_match_rule(Op_DivModI)) {
3727           DivModINode* divmod = DivModINode::make(n);
3728           d->subsume_by(divmod->div_proj(), this);
3729           n->subsume_by(divmod->mod_proj(), this);
3730         } else {
3731           // replace a%b with a-((a/b)*b)
3732           Node* mult = new MulINode(d, d->in(2));
3733           Node* sub  = new SubINode(d->in(1), mult);
3734           n->subsume_by(sub, this);
3735         }
3736       }
3737     }
3738     break;
3739 
3740   case Op_ModL:
3741     if (UseDivMod) {
3742       // Check if a%b and a/b both exist
3743       Node* d = n->find_similar(Op_DivL);
3744       if (d) {
3745         // Replace them with a fused divmod if supported
3746         if (Matcher::has_match_rule(Op_DivModL)) {
3747           DivModLNode* divmod = DivModLNode::make(n);
3748           d->subsume_by(divmod->div_proj(), this);
3749           n->subsume_by(divmod->mod_proj(), this);
3750         } else {
3751           // replace a%b with a-((a/b)*b)
3752           Node* mult = new MulLNode(d, d->in(2));
3753           Node* sub  = new SubLNode(d->in(1), mult);
3754           n->subsume_by(sub, this);
3755         }
3756       }
3757     }
3758     break;
3759 
3760   case Op_LoadVector:
3761   case Op_StoreVector:
3762     break;
3763 
3764   case Op_AddReductionVI:
3765   case Op_AddReductionVL:
3766   case Op_AddReductionVF:
3767   case Op_AddReductionVD:
3768   case Op_MulReductionVI:
3769   case Op_MulReductionVL:
3770   case Op_MulReductionVF:
3771   case Op_MulReductionVD:
3772   case Op_MinReductionV:
3773   case Op_MaxReductionV:
3774   case Op_AndReductionV:
3775   case Op_OrReductionV:
3776   case Op_XorReductionV:
3777     break;
3778 
3779   case Op_PackB:
3780   case Op_PackS:
3781   case Op_PackI:
3782   case Op_PackF:
3783   case Op_PackL:
3784   case Op_PackD:
3785     if (n->req()-1 > 2) {
3786       // Replace many operand PackNodes with a binary tree for matching
3787       PackNode* p = (PackNode*) n;
3788       Node* btp = p->binary_tree_pack(1, n->req());
3789       n->subsume_by(btp, this);
3790     }
3791     break;
3792   case Op_Loop:
3793   case Op_CountedLoop:
3794   case Op_OuterStripMinedLoop:
3795     if (n->as_Loop()->is_inner_loop()) {
3796       frc.inc_inner_loop_count();
3797     }
3798     n->as_Loop()->verify_strip_mined(0);
3799     break;
3800   case Op_LShiftI:
3801   case Op_RShiftI:
3802   case Op_URShiftI:
3803   case Op_LShiftL:
3804   case Op_RShiftL:
3805   case Op_URShiftL:
3806     if (Matcher::need_masked_shift_count) {
3807       // The cpu's shift instructions don't restrict the count to the
3808       // lower 5/6 bits. We need to do the masking ourselves.
3809       Node* in2 = n->in(2);
3810       juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
3811       const TypeInt* t = in2->find_int_type();
3812       if (t != NULL && t->is_con()) {
3813         juint shift = t->get_con();
3814         if (shift > mask) { // Unsigned cmp
3815           n->set_req(2, ConNode::make(TypeInt::make(shift & mask)));
3816         }
3817       } else {
3818         if (t == NULL || t->_lo < 0 || t->_hi > (int)mask) {
3819           Node* shift = new AndINode(in2, ConNode::make(TypeInt::make(mask)));
3820           n->set_req(2, shift);
3821         }
3822       }
3823       if (in2->outcnt() == 0) { // Remove dead node
3824         in2->disconnect_inputs(NULL, this);
3825       }
3826     }
3827     break;
3828   case Op_MemBarStoreStore:
3829   case Op_MemBarRelease:
3830     // Break the link with AllocateNode: it is no longer useful and
3831     // confuses register allocation.
3832     if (n->req() > MemBarNode::Precedent) {
3833       n->set_req(MemBarNode::Precedent, top());
3834     }
3835     break;
3836   case Op_MemBarAcquire: {
3837     if (n->as_MemBar()->trailing_load() && n->req() > MemBarNode::Precedent) {
3838       // At parse time, the trailing MemBarAcquire for a volatile load
3839       // is created with an edge to the load. After optimizations,
3840       // that input may be a chain of Phis. If those phis have no
3841       // other use, then the MemBarAcquire keeps them alive and
3842       // register allocation can be confused.
3843       ResourceMark rm;
3844       Unique_Node_List wq;
3845       wq.push(n->in(MemBarNode::Precedent));
3846       n->set_req(MemBarNode::Precedent, top());
3847       while (wq.size() > 0) {
3848         Node* m = wq.pop();
3849         if (m->outcnt() == 0) {
3850           for (uint j = 0; j < m->req(); j++) {
3851             Node* in = m->in(j);
3852             if (in != NULL) {
3853               wq.push(in);
3854             }
3855           }
3856           m->disconnect_inputs(NULL, this);
3857         }
3858       }
3859     }
3860     break;
3861   }
3862   case Op_RangeCheck: {
3863     RangeCheckNode* rc = n->as_RangeCheck();
3864     Node* iff = new IfNode(rc->in(0), rc->in(1), rc->_prob, rc->_fcnt);
3865     n->subsume_by(iff, this);
3866     frc._tests.push(iff);
3867     break;
3868   }
3869   case Op_ConvI2L: {
3870     if (!Matcher::convi2l_type_required) {
3871       // Code generation on some platforms doesn't need accurate
3872       // ConvI2L types. Widening the type can help remove redundant
3873       // address computations.
3874       n->as_Type()->set_type(TypeLong::INT);
3875       ResourceMark rm;
3876       Unique_Node_List wq;
3877       wq.push(n);
3878       for (uint next = 0; next < wq.size(); next++) {
3879         Node *m = wq.at(next);
3880 
3881         for(;;) {
3882           // Loop over all nodes with identical inputs edges as m
3883           Node* k = m->find_similar(m->Opcode());
3884           if (k == NULL) {
3885             break;
3886           }
3887           // Push their uses so we get a chance to remove node made
3888           // redundant
3889           for (DUIterator_Fast imax, i = k->fast_outs(imax); i < imax; i++) {
3890             Node* u = k->fast_out(i);
3891             if (u->Opcode() == Op_LShiftL ||
3892                 u->Opcode() == Op_AddL ||
3893                 u->Opcode() == Op_SubL ||
3894                 u->Opcode() == Op_AddP) {
3895               wq.push(u);
3896             }
3897           }
3898           // Replace all nodes with identical edges as m with m
3899           k->subsume_by(m, this);
3900         }
3901       }
3902     }
3903     break;
3904   }
3905   case Op_CmpUL: {
3906     if (!Matcher::has_match_rule(Op_CmpUL)) {
3907       // No support for unsigned long comparisons
3908       ConINode* sign_pos = new ConINode(TypeInt::make(BitsPerLong - 1));
3909       Node* sign_bit_mask = new RShiftLNode(n->in(1), sign_pos);
3910       Node* orl = new OrLNode(n->in(1), sign_bit_mask);
3911       ConLNode* remove_sign_mask = new ConLNode(TypeLong::make(max_jlong));
3912       Node* andl = new AndLNode(orl, remove_sign_mask);
3913       Node* cmp = new CmpLNode(andl, n->in(2));
3914       n->subsume_by(cmp, this);
3915     }
3916     break;
3917   }
3918 #ifdef ASSERT
3919   case Op_InlineTypePtr:
3920   case Op_InlineType: {
3921     n->dump(-1);
3922     assert(false, "inline type node was not removed");
3923     break;
3924   }
3925 #endif
3926   default:
3927     assert(!n->is_Call(), "");
3928     assert(!n->is_Mem(), "");
3929     assert(nop != Op_ProfileBoolean, "should be eliminated during IGVN");
3930     break;
3931   }
3932 }
3933 
3934 //------------------------------final_graph_reshaping_walk---------------------
3935 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
3936 // requires that the walk visits a node's inputs before visiting the node.
3937 void Compile::final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Reshape_Counts &frc ) {
3938   Unique_Node_List sfpt;
3939 
3940   frc._visited.set(root->_idx); // first, mark node as visited
3941   uint cnt = root->req();
3942   Node *n = root;
3943   uint  i = 0;
3944   while (true) {
3945     if (i < cnt) {
3946       // Place all non-visited non-null inputs onto stack
3947       Node* m = n->in(i);
3948       ++i;
3949       if (m != NULL && !frc._visited.test_set(m->_idx)) {
3950         if (m->is_SafePoint() && m->as_SafePoint()->jvms() != NULL) {
3951           // compute worst case interpreter size in case of a deoptimization
3952           update_interpreter_frame_size(m->as_SafePoint()->jvms()->interpreter_frame_size());
3953 
3954           sfpt.push(m);
3955         }
3956         cnt = m->req();
3957         nstack.push(n, i); // put on stack parent and next input's index
3958         n = m;
3959         i = 0;
3960       }
3961     } else {
3962       // Now do post-visit work
3963       final_graph_reshaping_impl( n, frc );
3964       if (nstack.is_empty())
3965         break;             // finished
3966       n = nstack.node();   // Get node from stack
3967       cnt = n->req();
3968       i = nstack.index();
3969       nstack.pop();        // Shift to the next node on stack
3970     }
3971   }
3972 
3973   // Skip next transformation if compressed oops are not used.
3974   if ((UseCompressedOops && !Matcher::gen_narrow_oop_implicit_null_checks()) ||
3975       (!UseCompressedOops && !UseCompressedClassPointers))
3976     return;
3977 
3978   // Go over safepoints nodes to skip DecodeN/DecodeNKlass nodes for debug edges.
3979   // It could be done for an uncommon traps or any safepoints/calls
3980   // if the DecodeN/DecodeNKlass node is referenced only in a debug info.
3981   while (sfpt.size() > 0) {
3982     n = sfpt.pop();
3983     JVMState *jvms = n->as_SafePoint()->jvms();
3984     assert(jvms != NULL, "sanity");
3985     int start = jvms->debug_start();
3986     int end   = n->req();
3987     bool is_uncommon = (n->is_CallStaticJava() &&
3988                         n->as_CallStaticJava()->uncommon_trap_request() != 0);
3989     for (int j = start; j < end; j++) {
3990       Node* in = n->in(j);
3991       if (in->is_DecodeNarrowPtr()) {
3992         bool safe_to_skip = true;
3993         if (!is_uncommon ) {
3994           // Is it safe to skip?
3995           for (uint i = 0; i < in->outcnt(); i++) {
3996             Node* u = in->raw_out(i);
3997             if (!u->is_SafePoint() ||
3998                 (u->is_Call() && u->as_Call()->has_non_debug_use(n))) {
3999               safe_to_skip = false;
4000             }
4001           }
4002         }
4003         if (safe_to_skip) {
4004           n->set_req(j, in->in(1));
4005         }
4006         if (in->outcnt() == 0) {
4007           in->disconnect_inputs(NULL, this);
4008         }
4009       }
4010     }
4011   }
4012 }
4013 
4014 //------------------------------final_graph_reshaping--------------------------
4015 // Final Graph Reshaping.
4016 //
4017 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
4018 //     and not commoned up and forced early.  Must come after regular
4019 //     optimizations to avoid GVN undoing the cloning.  Clone constant
4020 //     inputs to Loop Phis; these will be split by the allocator anyways.
4021 //     Remove Opaque nodes.
4022 // (2) Move last-uses by commutative operations to the left input to encourage
4023 //     Intel update-in-place two-address operations and better register usage
4024 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
4025 //     calls canonicalizing them back.
4026 // (3) Count the number of double-precision FP ops, single-precision FP ops
4027 //     and call sites.  On Intel, we can get correct rounding either by
4028 //     forcing singles to memory (requires extra stores and loads after each
4029 //     FP bytecode) or we can set a rounding mode bit (requires setting and
4030 //     clearing the mode bit around call sites).  The mode bit is only used
4031 //     if the relative frequency of single FP ops to calls is low enough.
4032 //     This is a key transform for SPEC mpeg_audio.
4033 // (4) Detect infinite loops; blobs of code reachable from above but not
4034 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
4035 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
4036 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
4037 //     Detection is by looking for IfNodes where only 1 projection is
4038 //     reachable from below or CatchNodes missing some targets.
4039 // (5) Assert for insane oop offsets in debug mode.
4040 
4041 bool Compile::final_graph_reshaping() {
4042   // an infinite loop may have been eliminated by the optimizer,
4043   // in which case the graph will be empty.
4044   if (root()->req() == 1) {
4045     record_method_not_compilable("trivial infinite loop");
4046     return true;
4047   }
4048 
4049   // Expensive nodes have their control input set to prevent the GVN
4050   // from freely commoning them. There's no GVN beyond this point so
4051   // no need to keep the control input. We want the expensive nodes to
4052   // be freely moved to the least frequent code path by gcm.
4053   assert(OptimizeExpensiveOps || expensive_count() == 0, "optimization off but list non empty?");
4054   for (int i = 0; i < expensive_count(); i++) {
4055     _expensive_nodes->at(i)->set_req(0, NULL);
4056   }
4057 
4058   Final_Reshape_Counts frc;
4059 
4060   // Visit everybody reachable!
4061   // Allocate stack of size C->live_nodes()/2 to avoid frequent realloc
4062   Node_Stack nstack(live_nodes() >> 1);
4063   final_graph_reshaping_walk(nstack, root(), frc);
4064 
4065   // Check for unreachable (from below) code (i.e., infinite loops).
4066   for( uint i = 0; i < frc._tests.size(); i++ ) {
4067     MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
4068     // Get number of CFG targets.
4069     // Note that PCTables include exception targets after calls.
4070     uint required_outcnt = n->required_outcnt();
4071     if (n->outcnt() != required_outcnt) {
4072       // Check for a few special cases.  Rethrow Nodes never take the
4073       // 'fall-thru' path, so expected kids is 1 less.
4074       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
4075         if (n->in(0)->in(0)->is_Call()) {
4076           CallNode *call = n->in(0)->in(0)->as_Call();
4077           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
4078             required_outcnt--;      // Rethrow always has 1 less kid
4079           } else if (call->req() > TypeFunc::Parms &&
4080                      call->is_CallDynamicJava()) {
4081             // Check for null receiver. In such case, the optimizer has
4082             // detected that the virtual call will always result in a null
4083             // pointer exception. The fall-through projection of this CatchNode
4084             // will not be populated.
4085             Node *arg0 = call->in(TypeFunc::Parms);
4086             if (arg0->is_Type() &&
4087                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
4088               required_outcnt--;
4089             }
4090           } else if (call->entry_point() == OptoRuntime::new_array_Java() &&
4091                      call->req() > TypeFunc::Parms+1 &&
4092                      call->is_CallStaticJava()) {
4093             // Check for negative array length. In such case, the optimizer has
4094             // detected that the allocation attempt will always result in an
4095             // exception. There is no fall-through projection of this CatchNode .
4096             Node *arg1 = call->in(TypeFunc::Parms+1);
4097             if (arg1->is_Type() &&
4098                 arg1->as_Type()->type()->join(TypeInt::POS)->empty()) {
4099               required_outcnt--;
4100             }
4101           }
4102         }
4103       }
4104       // Recheck with a better notion of 'required_outcnt'
4105       if (n->outcnt() != required_outcnt) {
4106         record_method_not_compilable("malformed control flow");
4107         return true;            // Not all targets reachable!
4108       }
4109     }
4110     // Check that I actually visited all kids.  Unreached kids
4111     // must be infinite loops.
4112     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
4113       if (!frc._visited.test(n->fast_out(j)->_idx)) {
4114         record_method_not_compilable("infinite loop");
4115         return true;            // Found unvisited kid; must be unreach
4116       }
4117 
4118     // Here so verification code in final_graph_reshaping_walk()
4119     // always see an OuterStripMinedLoopEnd
4120     if (n->is_OuterStripMinedLoopEnd()) {
4121       IfNode* init_iff = n->as_If();
4122       Node* iff = new IfNode(init_iff->in(0), init_iff->in(1), init_iff->_prob, init_iff->_fcnt);
4123       n->subsume_by(iff, this);
4124     }
4125   }
4126 
4127 #ifdef IA32
4128   // If original bytecodes contained a mixture of floats and doubles
4129   // check if the optimizer has made it homogenous, item (3).
4130   if (UseSSE == 0 &&
4131       frc.get_float_count() > 32 &&
4132       frc.get_double_count() == 0 &&
4133       (10 * frc.get_call_count() < frc.get_float_count()) ) {
4134     set_24_bit_selection_and_mode(false, true);
4135   }
4136 #endif // IA32
4137 
4138   set_java_calls(frc.get_java_call_count());
4139   set_inner_loops(frc.get_inner_loop_count());
4140 
4141   // No infinite loops, no reason to bail out.
4142   return false;
4143 }
4144 
4145 //-----------------------------too_many_traps----------------------------------
4146 // Report if there are too many traps at the current method and bci.
4147 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
4148 bool Compile::too_many_traps(ciMethod* method,
4149                              int bci,
4150                              Deoptimization::DeoptReason reason) {
4151   ciMethodData* md = method->method_data();
4152   if (md->is_empty()) {
4153     // Assume the trap has not occurred, or that it occurred only
4154     // because of a transient condition during start-up in the interpreter.
4155     return false;
4156   }
4157   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
4158   if (md->has_trap_at(bci, m, reason) != 0) {
4159     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
4160     // Also, if there are multiple reasons, or if there is no per-BCI record,
4161     // assume the worst.
4162     if (log())
4163       log()->elem("observe trap='%s' count='%d'",
4164                   Deoptimization::trap_reason_name(reason),
4165                   md->trap_count(reason));
4166     return true;
4167   } else {
4168     // Ignore method/bci and see if there have been too many globally.
4169     return too_many_traps(reason, md);
4170   }
4171 }
4172 
4173 // Less-accurate variant which does not require a method and bci.
4174 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
4175                              ciMethodData* logmd) {
4176   if (trap_count(reason) >= Deoptimization::per_method_trap_limit(reason)) {
4177     // Too many traps globally.
4178     // Note that we use cumulative trap_count, not just md->trap_count.
4179     if (log()) {
4180       int mcount = (logmd == NULL)? -1: (int)logmd->trap_count(reason);
4181       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
4182                   Deoptimization::trap_reason_name(reason),
4183                   mcount, trap_count(reason));
4184     }
4185     return true;
4186   } else {
4187     // The coast is clear.
4188     return false;
4189   }
4190 }
4191 
4192 //--------------------------too_many_recompiles--------------------------------
4193 // Report if there are too many recompiles at the current method and bci.
4194 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
4195 // Is not eager to return true, since this will cause the compiler to use
4196 // Action_none for a trap point, to avoid too many recompilations.
4197 bool Compile::too_many_recompiles(ciMethod* method,
4198                                   int bci,
4199                                   Deoptimization::DeoptReason reason) {
4200   ciMethodData* md = method->method_data();
4201   if (md->is_empty()) {
4202     // Assume the trap has not occurred, or that it occurred only
4203     // because of a transient condition during start-up in the interpreter.
4204     return false;
4205   }
4206   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
4207   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
4208   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
4209   Deoptimization::DeoptReason per_bc_reason
4210     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
4211   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
4212   if ((per_bc_reason == Deoptimization::Reason_none
4213        || md->has_trap_at(bci, m, reason) != 0)
4214       // The trap frequency measure we care about is the recompile count:
4215       && md->trap_recompiled_at(bci, m)
4216       && md->overflow_recompile_count() >= bc_cutoff) {
4217     // Do not emit a trap here if it has already caused recompilations.
4218     // Also, if there are multiple reasons, or if there is no per-BCI record,
4219     // assume the worst.
4220     if (log())
4221       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
4222                   Deoptimization::trap_reason_name(reason),
4223                   md->trap_count(reason),
4224                   md->overflow_recompile_count());
4225     return true;
4226   } else if (trap_count(reason) != 0
4227              && decompile_count() >= m_cutoff) {
4228     // Too many recompiles globally, and we have seen this sort of trap.
4229     // Use cumulative decompile_count, not just md->decompile_count.
4230     if (log())
4231       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
4232                   Deoptimization::trap_reason_name(reason),
4233                   md->trap_count(reason), trap_count(reason),
4234                   md->decompile_count(), decompile_count());
4235     return true;
4236   } else {
4237     // The coast is clear.
4238     return false;
4239   }
4240 }
4241 
4242 // Compute when not to trap. Used by matching trap based nodes and
4243 // NullCheck optimization.
4244 void Compile::set_allowed_deopt_reasons() {
4245   _allowed_reasons = 0;
4246   if (is_method_compilation()) {
4247     for (int rs = (int)Deoptimization::Reason_none+1; rs < Compile::trapHistLength; rs++) {
4248       assert(rs < BitsPerInt, "recode bit map");
4249       if (!too_many_traps((Deoptimization::DeoptReason) rs)) {
4250         _allowed_reasons |= nth_bit(rs);
4251       }
4252     }
4253   }
4254 }
4255 
4256 bool Compile::needs_clinit_barrier(ciMethod* method, ciMethod* accessing_method) {
4257   return method->is_static() && needs_clinit_barrier(method->holder(), accessing_method);
4258 }
4259 
4260 bool Compile::needs_clinit_barrier(ciField* field, ciMethod* accessing_method) {
4261   return field->is_static() && needs_clinit_barrier(field->holder(), accessing_method);
4262 }
4263 
4264 bool Compile::needs_clinit_barrier(ciInstanceKlass* holder, ciMethod* accessing_method) {
4265   if (holder->is_initialized()) {
4266     return false;
4267   }
4268   if (holder->is_being_initialized()) {
4269     if (accessing_method->holder() == holder) {
4270       // Access inside a class. The barrier can be elided when access happens in <clinit>,
4271       // <init>, or a static method. In all those cases, there was an initialization
4272       // barrier on the holder klass passed.
4273       if (accessing_method->is_class_initializer() ||
4274           accessing_method->is_object_constructor() ||
4275           accessing_method->is_static()) {
4276         return false;
4277       }
4278     } else if (accessing_method->holder()->is_subclass_of(holder)) {
4279       // Access from a subclass. The barrier can be elided only when access happens in <clinit>.
4280       // In case of <init> or a static method, the barrier is on the subclass is not enough:
4281       // child class can become fully initialized while its parent class is still being initialized.
4282       if (accessing_method->is_class_initializer()) {
4283         return false;
4284       }
4285     }
4286     ciMethod* root = method(); // the root method of compilation
4287     if (root != accessing_method) {
4288       return needs_clinit_barrier(holder, root); // check access in the context of compilation root
4289     }
4290   }
4291   return true;
4292 }
4293 
4294 #ifndef PRODUCT
4295 //------------------------------verify_graph_edges---------------------------
4296 // Walk the Graph and verify that there is a one-to-one correspondence
4297 // between Use-Def edges and Def-Use edges in the graph.
4298 void Compile::verify_graph_edges(bool no_dead_code) {
4299   if (VerifyGraphEdges) {
4300     Unique_Node_List visited;
4301     // Call recursive graph walk to check edges
4302     _root->verify_edges(visited);
4303     if (no_dead_code) {
4304       // Now make sure that no visited node is used by an unvisited node.
4305       bool dead_nodes = false;
4306       Unique_Node_List checked;
4307       while (visited.size() > 0) {
4308         Node* n = visited.pop();
4309         checked.push(n);
4310         for (uint i = 0; i < n->outcnt(); i++) {
4311           Node* use = n->raw_out(i);
4312           if (checked.member(use))  continue;  // already checked
4313           if (visited.member(use))  continue;  // already in the graph
4314           if (use->is_Con())        continue;  // a dead ConNode is OK
4315           // At this point, we have found a dead node which is DU-reachable.
4316           if (!dead_nodes) {
4317             tty->print_cr("*** Dead nodes reachable via DU edges:");
4318             dead_nodes = true;
4319           }
4320           use->dump(2);
4321           tty->print_cr("---");
4322           checked.push(use);  // No repeats; pretend it is now checked.
4323         }
4324       }
4325       assert(!dead_nodes, "using nodes must be reachable from root");
4326     }
4327   }
4328 }
4329 #endif
4330 
4331 // The Compile object keeps track of failure reasons separately from the ciEnv.
4332 // This is required because there is not quite a 1-1 relation between the
4333 // ciEnv and its compilation task and the Compile object.  Note that one
4334 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
4335 // to backtrack and retry without subsuming loads.  Other than this backtracking
4336 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
4337 // by the logic in C2Compiler.
4338 void Compile::record_failure(const char* reason) {
4339   if (log() != NULL) {
4340     log()->elem("failure reason='%s' phase='compile'", reason);
4341   }
4342   if (_failure_reason == NULL) {
4343     // Record the first failure reason.
4344     _failure_reason = reason;
4345   }
4346 
4347   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
4348     C->print_method(PHASE_FAILURE);
4349   }
4350   _root = NULL;  // flush the graph, too
4351 }
4352 
4353 Compile::TracePhase::TracePhase(const char* name, elapsedTimer* accumulator)
4354   : TraceTime(name, accumulator, CITime, CITimeVerbose),
4355     _phase_name(name), _dolog(CITimeVerbose)
4356 {
4357   if (_dolog) {
4358     C = Compile::current();
4359     _log = C->log();
4360   } else {
4361     C = NULL;
4362     _log = NULL;
4363   }
4364   if (_log != NULL) {
4365     _log->begin_head("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
4366     _log->stamp();
4367     _log->end_head();
4368   }
4369 }
4370 
4371 Compile::TracePhase::~TracePhase() {
4372 
4373   C = Compile::current();
4374   if (_dolog) {
4375     _log = C->log();
4376   } else {
4377     _log = NULL;
4378   }
4379 
4380 #ifdef ASSERT
4381   if (PrintIdealNodeCount) {
4382     tty->print_cr("phase name='%s' nodes='%d' live='%d' live_graph_walk='%d'",
4383                   _phase_name, C->unique(), C->live_nodes(), C->count_live_nodes_by_graph_walk());
4384   }
4385 
4386   if (VerifyIdealNodeCount) {
4387     Compile::current()->print_missing_nodes();
4388   }
4389 #endif
4390 
4391   if (_log != NULL) {
4392     _log->done("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
4393   }
4394 }
4395 
4396 //----------------------------static_subtype_check-----------------------------
4397 // Shortcut important common cases when superklass is exact:
4398 // (0) superklass is java.lang.Object (can occur in reflective code)
4399 // (1) subklass is already limited to a subtype of superklass => always ok
4400 // (2) subklass does not overlap with superklass => always fail
4401 // (3) superklass has NO subtypes and we can check with a simple compare.
4402 int Compile::static_subtype_check(ciKlass* superk, ciKlass* subk) {
4403   if (StressReflectiveCode || superk == NULL || subk == NULL) {
4404     return SSC_full_test;       // Let caller generate the general case.
4405   }
4406 
4407   if (superk == env()->Object_klass()) {
4408     return SSC_always_true;     // (0) this test cannot fail
4409   }
4410 
4411   ciType* superelem = superk;
4412   if (superelem->is_array_klass()) {
4413     ciArrayKlass* ak = superelem->as_array_klass();
4414     superelem = superelem->as_array_klass()->base_element_type();
4415   }
4416 
4417   if (!subk->is_interface()) {  // cannot trust static interface types yet
4418     if (subk->is_subtype_of(superk)) {
4419       return SSC_always_true;   // (1) false path dead; no dynamic test needed
4420     }
4421     if (!(superelem->is_klass() && superelem->as_klass()->is_interface()) &&
4422         !superk->is_subtype_of(subk)) {
4423       return SSC_always_false;
4424     }
4425   }
4426 
4427   // If casting to an instance klass, it must have no subtypes
4428   if (superk->is_interface()) {
4429     // Cannot trust interfaces yet.
4430     // %%% S.B. superk->nof_implementors() == 1
4431   } else if (superelem->is_instance_klass()) {
4432     ciInstanceKlass* ik = superelem->as_instance_klass();
4433     if (!ik->has_subklass() && !ik->is_interface()) {
4434       if (!ik->is_final()) {
4435         // Add a dependency if there is a chance of a later subclass.
4436         dependencies()->assert_leaf_type(ik);
4437       }
4438       return SSC_easy_test;     // (3) caller can do a simple ptr comparison
4439     }
4440   } else {
4441     // A primitive array type has no subtypes.
4442     return SSC_easy_test;       // (3) caller can do a simple ptr comparison
4443   }
4444 
4445   return SSC_full_test;
4446 }
4447 
4448 Node* Compile::conv_I2X_index(PhaseGVN* phase, Node* idx, const TypeInt* sizetype, Node* ctrl) {
4449 #ifdef _LP64
4450   // The scaled index operand to AddP must be a clean 64-bit value.
4451   // Java allows a 32-bit int to be incremented to a negative
4452   // value, which appears in a 64-bit register as a large
4453   // positive number.  Using that large positive number as an
4454   // operand in pointer arithmetic has bad consequences.
4455   // On the other hand, 32-bit overflow is rare, and the possibility
4456   // can often be excluded, if we annotate the ConvI2L node with
4457   // a type assertion that its value is known to be a small positive
4458   // number.  (The prior range check has ensured this.)
4459   // This assertion is used by ConvI2LNode::Ideal.
4460   int index_max = max_jint - 1;  // array size is max_jint, index is one less
4461   if (sizetype != NULL) index_max = sizetype->_hi - 1;
4462   const TypeInt* iidxtype = TypeInt::make(0, index_max, Type::WidenMax);
4463   idx = constrained_convI2L(phase, idx, iidxtype, ctrl);
4464 #endif
4465   return idx;
4466 }
4467 
4468 // Convert integer value to a narrowed long type dependent on ctrl (for example, a range check)
4469 Node* Compile::constrained_convI2L(PhaseGVN* phase, Node* value, const TypeInt* itype, Node* ctrl) {
4470   if (ctrl != NULL) {
4471     // Express control dependency by a CastII node with a narrow type.
4472     value = new CastIINode(value, itype, false, true /* range check dependency */);
4473     // Make the CastII node dependent on the control input to prevent the narrowed ConvI2L
4474     // node from floating above the range check during loop optimizations. Otherwise, the
4475     // ConvI2L node may be eliminated independently of the range check, causing the data path
4476     // to become TOP while the control path is still there (although it's unreachable).
4477     value->set_req(0, ctrl);
4478     // Save CastII node to remove it after loop optimizations.
4479     phase->C->add_range_check_cast(value);
4480     value = phase->transform(value);
4481   }
4482   const TypeLong* ltype = TypeLong::make(itype->_lo, itype->_hi, itype->_widen);
4483   return phase->transform(new ConvI2LNode(value, ltype));
4484 }
4485 
4486 void Compile::print_inlining_stream_free() {
4487   if (_print_inlining_stream != NULL) {
4488     _print_inlining_stream->~stringStream();
4489     _print_inlining_stream = NULL;
4490   }
4491 }
4492 
4493 // The message about the current inlining is accumulated in
4494 // _print_inlining_stream and transfered into the _print_inlining_list
4495 // once we know whether inlining succeeds or not. For regular
4496 // inlining, messages are appended to the buffer pointed by
4497 // _print_inlining_idx in the _print_inlining_list. For late inlining,
4498 // a new buffer is added after _print_inlining_idx in the list. This
4499 // way we can update the inlining message for late inlining call site
4500 // when the inlining is attempted again.
4501 void Compile::print_inlining_init() {
4502   if (print_inlining() || print_intrinsics()) {
4503     // print_inlining_init is actually called several times.
4504     print_inlining_stream_free();
4505     _print_inlining_stream = new stringStream();
4506     // Watch out: The memory initialized by the constructor call PrintInliningBuffer()
4507     // will be copied into the only initial element. The default destructor of
4508     // PrintInliningBuffer will be called when leaving the scope here. If it
4509     // would destuct the  enclosed stringStream _print_inlining_list[0]->_ss
4510     // would be destructed, too!
4511     _print_inlining_list = new (comp_arena())GrowableArray<PrintInliningBuffer>(comp_arena(), 1, 1, PrintInliningBuffer());
4512   }
4513 }
4514 
4515 void Compile::print_inlining_reinit() {
4516   if (print_inlining() || print_intrinsics()) {
4517     print_inlining_stream_free();
4518     // Re allocate buffer when we change ResourceMark
4519     _print_inlining_stream = new stringStream();
4520   }
4521 }
4522 
4523 void Compile::print_inlining_reset() {
4524   _print_inlining_stream->reset();
4525 }
4526 
4527 void Compile::print_inlining_commit() {
4528   assert(print_inlining() || print_intrinsics(), "PrintInlining off?");
4529   // Transfer the message from _print_inlining_stream to the current
4530   // _print_inlining_list buffer and clear _print_inlining_stream.
4531   _print_inlining_list->at(_print_inlining_idx).ss()->write(_print_inlining_stream->base(), _print_inlining_stream->size());
4532   print_inlining_reset();
4533 }
4534 
4535 void Compile::print_inlining_push() {
4536   // Add new buffer to the _print_inlining_list at current position
4537   _print_inlining_idx++;
4538   _print_inlining_list->insert_before(_print_inlining_idx, PrintInliningBuffer());
4539 }
4540 
4541 Compile::PrintInliningBuffer& Compile::print_inlining_current() {
4542   return _print_inlining_list->at(_print_inlining_idx);
4543 }
4544 
4545 void Compile::print_inlining_update(CallGenerator* cg) {
4546   if (print_inlining() || print_intrinsics()) {
4547     if (!cg->is_late_inline()) {
4548       if (print_inlining_current().cg() != NULL) {
4549         print_inlining_push();
4550       }
4551       print_inlining_commit();
4552     } else {
4553       if (print_inlining_current().cg() != cg &&
4554           (print_inlining_current().cg() != NULL ||
4555            print_inlining_current().ss()->size() != 0)) {
4556         print_inlining_push();
4557       }
4558       print_inlining_commit();
4559       print_inlining_current().set_cg(cg);
4560     }
4561   }
4562 }
4563 
4564 void Compile::print_inlining_move_to(CallGenerator* cg) {
4565   // We resume inlining at a late inlining call site. Locate the
4566   // corresponding inlining buffer so that we can update it.
4567   if (print_inlining()) {
4568     for (int i = 0; i < _print_inlining_list->length(); i++) {
4569       if (_print_inlining_list->adr_at(i)->cg() == cg) {
4570         _print_inlining_idx = i;
4571         return;
4572       }
4573     }
4574     ShouldNotReachHere();
4575   }
4576 }
4577 
4578 void Compile::print_inlining_update_delayed(CallGenerator* cg) {
4579   if (print_inlining()) {
4580     assert(_print_inlining_stream->size() > 0, "missing inlining msg");
4581     assert(print_inlining_current().cg() == cg, "wrong entry");
4582     // replace message with new message
4583     _print_inlining_list->at_put(_print_inlining_idx, PrintInliningBuffer());
4584     print_inlining_commit();
4585     print_inlining_current().set_cg(cg);
4586   }
4587 }
4588 
4589 void Compile::print_inlining_assert_ready() {
4590   assert(!_print_inlining || _print_inlining_stream->size() == 0, "loosing data");
4591 }
4592 
4593 void Compile::process_print_inlining() {
4594   bool do_print_inlining = print_inlining() || print_intrinsics();
4595   if (do_print_inlining || log() != NULL) {
4596     // Print inlining message for candidates that we couldn't inline
4597     // for lack of space
4598     for (int i = 0; i < _late_inlines.length(); i++) {
4599       CallGenerator* cg = _late_inlines.at(i);
4600       if (!cg->is_mh_late_inline()) {
4601         const char* msg = "live nodes > LiveNodeCountInliningCutoff";
4602         if (do_print_inlining) {
4603           cg->print_inlining_late(msg);
4604         }
4605         log_late_inline_failure(cg, msg);
4606       }
4607     }
4608   }
4609   if (do_print_inlining) {
4610     ResourceMark rm;
4611     stringStream ss;
4612     assert(_print_inlining_list != NULL, "process_print_inlining should be called only once.");
4613     for (int i = 0; i < _print_inlining_list->length(); i++) {
4614       ss.print("%s", _print_inlining_list->adr_at(i)->ss()->as_string());
4615       _print_inlining_list->at(i).freeStream();
4616     }
4617     // Reset _print_inlining_list, it only contains destructed objects.
4618     // It is on the arena, so it will be freed when the arena is reset.
4619     _print_inlining_list = NULL;
4620     // _print_inlining_stream won't be used anymore, either.
4621     print_inlining_stream_free();
4622     size_t end = ss.size();
4623     _print_inlining_output = NEW_ARENA_ARRAY(comp_arena(), char, end+1);
4624     strncpy(_print_inlining_output, ss.base(), end+1);
4625     _print_inlining_output[end] = 0;
4626   }
4627 }
4628 
4629 void Compile::dump_print_inlining() {
4630   if (_print_inlining_output != NULL) {
4631     tty->print_raw(_print_inlining_output);
4632   }
4633 }
4634 
4635 void Compile::log_late_inline(CallGenerator* cg) {
4636   if (log() != NULL) {
4637     log()->head("late_inline method='%d'  inline_id='" JLONG_FORMAT "'", log()->identify(cg->method()),
4638                 cg->unique_id());
4639     JVMState* p = cg->call_node()->jvms();
4640     while (p != NULL) {
4641       log()->elem("jvms bci='%d' method='%d'", p->bci(), log()->identify(p->method()));
4642       p = p->caller();
4643     }
4644     log()->tail("late_inline");
4645   }
4646 }
4647 
4648 void Compile::log_late_inline_failure(CallGenerator* cg, const char* msg) {
4649   log_late_inline(cg);
4650   if (log() != NULL) {
4651     log()->inline_fail(msg);
4652   }
4653 }
4654 
4655 void Compile::log_inline_id(CallGenerator* cg) {
4656   if (log() != NULL) {
4657     // The LogCompilation tool needs a unique way to identify late
4658     // inline call sites. This id must be unique for this call site in
4659     // this compilation. Try to have it unique across compilations as
4660     // well because it can be convenient when grepping through the log
4661     // file.
4662     // Distinguish OSR compilations from others in case CICountOSR is
4663     // on.
4664     jlong id = ((jlong)unique()) + (((jlong)compile_id()) << 33) + (CICountOSR && is_osr_compilation() ? ((jlong)1) << 32 : 0);
4665     cg->set_unique_id(id);
4666     log()->elem("inline_id id='" JLONG_FORMAT "'", id);
4667   }
4668 }
4669 
4670 void Compile::log_inline_failure(const char* msg) {
4671   if (C->log() != NULL) {
4672     C->log()->inline_fail(msg);
4673   }
4674 }
4675 
4676 
4677 // Dump inlining replay data to the stream.
4678 // Don't change thread state and acquire any locks.
4679 void Compile::dump_inline_data(outputStream* out) {
4680   InlineTree* inl_tree = ilt();
4681   if (inl_tree != NULL) {
4682     out->print(" inline %d", inl_tree->count());
4683     inl_tree->dump_replay_data(out);
4684   }
4685 }
4686 
4687 int Compile::cmp_expensive_nodes(Node* n1, Node* n2) {
4688   if (n1->Opcode() < n2->Opcode())      return -1;
4689   else if (n1->Opcode() > n2->Opcode()) return 1;
4690 
4691   assert(n1->req() == n2->req(), "can't compare %s nodes: n1->req() = %d, n2->req() = %d", NodeClassNames[n1->Opcode()], n1->req(), n2->req());
4692   for (uint i = 1; i < n1->req(); i++) {
4693     if (n1->in(i) < n2->in(i))      return -1;
4694     else if (n1->in(i) > n2->in(i)) return 1;
4695   }
4696 
4697   return 0;
4698 }
4699 
4700 int Compile::cmp_expensive_nodes(Node** n1p, Node** n2p) {
4701   Node* n1 = *n1p;
4702   Node* n2 = *n2p;
4703 
4704   return cmp_expensive_nodes(n1, n2);
4705 }
4706 
4707 void Compile::sort_expensive_nodes() {
4708   if (!expensive_nodes_sorted()) {
4709     _expensive_nodes->sort(cmp_expensive_nodes);
4710   }
4711 }
4712 
4713 bool Compile::expensive_nodes_sorted() const {
4714   for (int i = 1; i < _expensive_nodes->length(); i++) {
4715     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i-1)) < 0) {
4716       return false;
4717     }
4718   }
4719   return true;
4720 }
4721 
4722 bool Compile::should_optimize_expensive_nodes(PhaseIterGVN &igvn) {
4723   if (_expensive_nodes->length() == 0) {
4724     return false;
4725   }
4726 
4727   assert(OptimizeExpensiveOps, "optimization off?");
4728 
4729   // Take this opportunity to remove dead nodes from the list
4730   int j = 0;
4731   for (int i = 0; i < _expensive_nodes->length(); i++) {
4732     Node* n = _expensive_nodes->at(i);
4733     if (!n->is_unreachable(igvn)) {
4734       assert(n->is_expensive(), "should be expensive");
4735       _expensive_nodes->at_put(j, n);
4736       j++;
4737     }
4738   }
4739   _expensive_nodes->trunc_to(j);
4740 
4741   // Then sort the list so that similar nodes are next to each other
4742   // and check for at least two nodes of identical kind with same data
4743   // inputs.
4744   sort_expensive_nodes();
4745 
4746   for (int i = 0; i < _expensive_nodes->length()-1; i++) {
4747     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i+1)) == 0) {
4748       return true;
4749     }
4750   }
4751 
4752   return false;
4753 }
4754 
4755 void Compile::cleanup_expensive_nodes(PhaseIterGVN &igvn) {
4756   if (_expensive_nodes->length() == 0) {
4757     return;
4758   }
4759 
4760   assert(OptimizeExpensiveOps, "optimization off?");
4761 
4762   // Sort to bring similar nodes next to each other and clear the
4763   // control input of nodes for which there's only a single copy.
4764   sort_expensive_nodes();
4765 
4766   int j = 0;
4767   int identical = 0;
4768   int i = 0;
4769   bool modified = false;
4770   for (; i < _expensive_nodes->length()-1; i++) {
4771     assert(j <= i, "can't write beyond current index");
4772     if (_expensive_nodes->at(i)->Opcode() == _expensive_nodes->at(i+1)->Opcode()) {
4773       identical++;
4774       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4775       continue;
4776     }
4777     if (identical > 0) {
4778       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4779       identical = 0;
4780     } else {
4781       Node* n = _expensive_nodes->at(i);
4782       igvn.replace_input_of(n, 0, NULL);
4783       igvn.hash_insert(n);
4784       modified = true;
4785     }
4786   }
4787   if (identical > 0) {
4788     _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4789   } else if (_expensive_nodes->length() >= 1) {
4790     Node* n = _expensive_nodes->at(i);
4791     igvn.replace_input_of(n, 0, NULL);
4792     igvn.hash_insert(n);
4793     modified = true;
4794   }
4795   _expensive_nodes->trunc_to(j);
4796   if (modified) {
4797     igvn.optimize();
4798   }
4799 }
4800 
4801 void Compile::add_expensive_node(Node * n) {
4802   assert(!_expensive_nodes->contains(n), "duplicate entry in expensive list");
4803   assert(n->is_expensive(), "expensive nodes with non-null control here only");
4804   assert(!n->is_CFG() && !n->is_Mem(), "no cfg or memory nodes here");
4805   if (OptimizeExpensiveOps) {
4806     _expensive_nodes->append(n);
4807   } else {
4808     // Clear control input and let IGVN optimize expensive nodes if
4809     // OptimizeExpensiveOps is off.
4810     n->set_req(0, NULL);
4811   }
4812 }
4813 
4814 /**
4815  * Remove the speculative part of types and clean up the graph
4816  */
4817 void Compile::remove_speculative_types(PhaseIterGVN &igvn) {
4818   if (UseTypeSpeculation) {
4819     Unique_Node_List worklist;
4820     worklist.push(root());
4821     int modified = 0;
4822     // Go over all type nodes that carry a speculative type, drop the
4823     // speculative part of the type and enqueue the node for an igvn
4824     // which may optimize it out.
4825     for (uint next = 0; next < worklist.size(); ++next) {
4826       Node *n  = worklist.at(next);
4827       if (n->is_Type()) {
4828         TypeNode* tn = n->as_Type();
4829         const Type* t = tn->type();
4830         const Type* t_no_spec = t->remove_speculative();
4831         if (t_no_spec != t) {
4832           bool in_hash = igvn.hash_delete(n);
4833           assert(in_hash, "node should be in igvn hash table");
4834           tn->set_type(t_no_spec);
4835           igvn.hash_insert(n);
4836           igvn._worklist.push(n); // give it a chance to go away
4837           modified++;
4838         }
4839       }
4840       uint max = n->len();
4841       for( uint i = 0; i < max; ++i ) {
4842         Node *m = n->in(i);
4843         if (not_a_node(m))  continue;
4844         worklist.push(m);
4845       }
4846     }
4847     // Drop the speculative part of all types in the igvn's type table
4848     igvn.remove_speculative_types();
4849     if (modified > 0) {
4850       igvn.optimize();
4851     }
4852 #ifdef ASSERT
4853     // Verify that after the IGVN is over no speculative type has resurfaced
4854     worklist.clear();
4855     worklist.push(root());
4856     for (uint next = 0; next < worklist.size(); ++next) {
4857       Node *n  = worklist.at(next);
4858       const Type* t = igvn.type_or_null(n);
4859       assert((t == NULL) || (t == t->remove_speculative()), "no more speculative types");
4860       if (n->is_Type()) {
4861         t = n->as_Type()->type();
4862         assert(t == t->remove_speculative(), "no more speculative types");
4863       }
4864       uint max = n->len();
4865       for( uint i = 0; i < max; ++i ) {
4866         Node *m = n->in(i);
4867         if (not_a_node(m))  continue;
4868         worklist.push(m);
4869       }
4870     }
4871     igvn.check_no_speculative_types();
4872 #endif
4873   }
4874 }
4875 
4876 Node* Compile::optimize_acmp(PhaseGVN* phase, Node* a, Node* b) {
4877   const TypeInstPtr* ta = phase->type(a)->isa_instptr();
4878   const TypeInstPtr* tb = phase->type(b)->isa_instptr();
4879   if (!EnableValhalla || ta == NULL || tb == NULL ||
4880       ta->is_zero_type() || tb->is_zero_type() ||
4881       !ta->can_be_inline_type() || !tb->can_be_inline_type()) {
4882     // Use old acmp if one operand is null or not an inline type
4883     return new CmpPNode(a, b);
4884   } else if (ta->is_inlinetypeptr() || tb->is_inlinetypeptr()) {
4885     // We know that one operand is an inline type. Therefore,
4886     // new acmp will only return true if both operands are NULL.
4887     // Check if both operands are null by or'ing the oops.
4888     a = phase->transform(new CastP2XNode(NULL, a));
4889     b = phase->transform(new CastP2XNode(NULL, b));
4890     a = phase->transform(new OrXNode(a, b));
4891     return new CmpXNode(a, phase->MakeConX(0));
4892   }
4893   // Use new acmp
4894   return NULL;
4895 }
4896 
4897 // Auxiliary method to support randomized stressing/fuzzing.
4898 //
4899 // This method can be called the arbitrary number of times, with current count
4900 // as the argument. The logic allows selecting a single candidate from the
4901 // running list of candidates as follows:
4902 //    int count = 0;
4903 //    Cand* selected = null;
4904 //    while(cand = cand->next()) {
4905 //      if (randomized_select(++count)) {
4906 //        selected = cand;
4907 //      }
4908 //    }
4909 //
4910 // Including count equalizes the chances any candidate is "selected".
4911 // This is useful when we don't have the complete list of candidates to choose
4912 // from uniformly. In this case, we need to adjust the randomicity of the
4913 // selection, or else we will end up biasing the selection towards the latter
4914 // candidates.
4915 //
4916 // Quick back-envelope calculation shows that for the list of n candidates
4917 // the equal probability for the candidate to persist as "best" can be
4918 // achieved by replacing it with "next" k-th candidate with the probability
4919 // of 1/k. It can be easily shown that by the end of the run, the
4920 // probability for any candidate is converged to 1/n, thus giving the
4921 // uniform distribution among all the candidates.
4922 //
4923 // We don't care about the domain size as long as (RANDOMIZED_DOMAIN / count) is large.
4924 #define RANDOMIZED_DOMAIN_POW 29
4925 #define RANDOMIZED_DOMAIN (1 << RANDOMIZED_DOMAIN_POW)
4926 #define RANDOMIZED_DOMAIN_MASK ((1 << (RANDOMIZED_DOMAIN_POW + 1)) - 1)
4927 bool Compile::randomized_select(int count) {
4928   assert(count > 0, "only positive");
4929   return (os::random() & RANDOMIZED_DOMAIN_MASK) < (RANDOMIZED_DOMAIN / count);
4930 }
4931 
4932 CloneMap&     Compile::clone_map()                 { return _clone_map; }
4933 void          Compile::set_clone_map(Dict* d)      { _clone_map._dict = d; }
4934 
4935 void NodeCloneInfo::dump() const {
4936   tty->print(" {%d:%d} ", idx(), gen());
4937 }
4938 
4939 void CloneMap::clone(Node* old, Node* nnn, int gen) {
4940   uint64_t val = value(old->_idx);
4941   NodeCloneInfo cio(val);
4942   assert(val != 0, "old node should be in the map");
4943   NodeCloneInfo cin(cio.idx(), gen + cio.gen());
4944   insert(nnn->_idx, cin.get());
4945 #ifndef PRODUCT
4946   if (is_debug()) {
4947     tty->print_cr("CloneMap::clone inserted node %d info {%d:%d} into CloneMap", nnn->_idx, cin.idx(), cin.gen());
4948   }
4949 #endif
4950 }
4951 
4952 void CloneMap::verify_insert_and_clone(Node* old, Node* nnn, int gen) {
4953   NodeCloneInfo cio(value(old->_idx));
4954   if (cio.get() == 0) {
4955     cio.set(old->_idx, 0);
4956     insert(old->_idx, cio.get());
4957 #ifndef PRODUCT
4958     if (is_debug()) {
4959       tty->print_cr("CloneMap::verify_insert_and_clone inserted node %d info {%d:%d} into CloneMap", old->_idx, cio.idx(), cio.gen());
4960     }
4961 #endif
4962   }
4963   clone(old, nnn, gen);
4964 }
4965 
4966 int CloneMap::max_gen() const {
4967   int g = 0;
4968   DictI di(_dict);
4969   for(; di.test(); ++di) {
4970     int t = gen(di._key);
4971     if (g < t) {
4972       g = t;
4973 #ifndef PRODUCT
4974       if (is_debug()) {
4975         tty->print_cr("CloneMap::max_gen() update max=%d from %d", g, _2_node_idx_t(di._key));
4976       }
4977 #endif
4978     }
4979   }
4980   return g;
4981 }
4982 
4983 void CloneMap::dump(node_idx_t key) const {
4984   uint64_t val = value(key);
4985   if (val != 0) {
4986     NodeCloneInfo ni(val);
4987     ni.dump();
4988   }
4989 }
4990 
4991 // Move Allocate nodes to the start of the list
4992 void Compile::sort_macro_nodes() {
4993   int count = macro_count();
4994   int allocates = 0;
4995   for (int i = 0; i < count; i++) {
4996     Node* n = macro_node(i);
4997     if (n->is_Allocate()) {
4998       if (i != allocates) {
4999         Node* tmp = macro_node(allocates);
5000         _macro_nodes->at_put(allocates, n);
5001         _macro_nodes->at_put(i, tmp);
5002       }
5003       allocates++;
5004     }
5005   }
5006 }
5007 
5008 void Compile::print_method(CompilerPhaseType cpt, int level, int idx) {
5009   EventCompilerPhase event;
5010   if (event.should_commit()) {
5011     CompilerEvent::PhaseEvent::post(event, C->_latest_stage_start_counter, cpt, C->_compile_id, level);
5012   }
5013 
5014 #ifndef PRODUCT
5015   if (should_print(level)) {
5016     char output[1024];
5017     if (idx != 0) {
5018       jio_snprintf(output, sizeof(output), "%s:%d", CompilerPhaseTypeHelper::to_string(cpt), idx);
5019     } else {
5020       jio_snprintf(output, sizeof(output), "%s", CompilerPhaseTypeHelper::to_string(cpt));
5021     }
5022     _printer->print_method(output, level);
5023   }
5024 #endif
5025   C->_latest_stage_start_counter.stamp();
5026 }
5027 
5028 void Compile::end_method(int level) {
5029   EventCompilerPhase event;
5030   if (event.should_commit()) {
5031     CompilerEvent::PhaseEvent::post(event, C->_latest_stage_start_counter, PHASE_END, C->_compile_id, level);
5032   }
5033 
5034 #ifndef PRODUCT
5035   if (_method != NULL && should_print(level)) {
5036     _printer->end_method();
5037   }
5038 #endif
5039 }
5040 
5041 
5042 #ifndef PRODUCT
5043 IdealGraphPrinter* Compile::_debug_file_printer = NULL;
5044 IdealGraphPrinter* Compile::_debug_network_printer = NULL;
5045 
5046 // Called from debugger. Prints method to the default file with the default phase name.
5047 // This works regardless of any Ideal Graph Visualizer flags set or not.
5048 void igv_print() {
5049   Compile::current()->igv_print_method_to_file();
5050 }
5051 
5052 // Same as igv_print() above but with a specified phase name.
5053 void igv_print(const char* phase_name) {
5054   Compile::current()->igv_print_method_to_file(phase_name);
5055 }
5056 
5057 // Called from debugger. Prints method with the default phase name to the default network or the one specified with
5058 // the network flags for the Ideal Graph Visualizer, or to the default file depending on the 'network' argument.
5059 // This works regardless of any Ideal Graph Visualizer flags set or not.
5060 void igv_print(bool network) {
5061   if (network) {
5062     Compile::current()->igv_print_method_to_network();
5063   } else {
5064     Compile::current()->igv_print_method_to_file();
5065   }
5066 }
5067 
5068 // Same as igv_print(bool network) above but with a specified phase name.
5069 void igv_print(bool network, const char* phase_name) {
5070   if (network) {
5071     Compile::current()->igv_print_method_to_network(phase_name);
5072   } else {
5073     Compile::current()->igv_print_method_to_file(phase_name);
5074   }
5075 }
5076 
5077 // Called from debugger. Normal write to the default _printer. Only works if Ideal Graph Visualizer printing flags are set.
5078 void igv_print_default() {
5079   Compile::current()->print_method(PHASE_DEBUG, 0, 0);
5080 }
5081 
5082 // Called from debugger, especially when replaying a trace in which the program state cannot be altered like with rr replay.
5083 // A method is appended to an existing default file with the default phase name. This means that igv_append() must follow
5084 // an earlier igv_print(*) call which sets up the file. This works regardless of any Ideal Graph Visualizer flags set or not.
5085 void igv_append() {
5086   Compile::current()->igv_print_method_to_file("Debug", true);
5087 }
5088 
5089 // Same as igv_append() above but with a specified phase name.
5090 void igv_append(const char* phase_name) {
5091   Compile::current()->igv_print_method_to_file(phase_name, true);
5092 }
5093 
5094 void Compile::igv_print_method_to_file(const char* phase_name, bool append) {
5095   const char* file_name = "custom_debug.xml";
5096   if (_debug_file_printer == NULL) {
5097     _debug_file_printer = new IdealGraphPrinter(C, file_name, append);
5098   } else {
5099     _debug_file_printer->update_compiled_method(C->method());
5100   }
5101   tty->print_cr("Method %s to %s", append ? "appended" : "printed", file_name);
5102   _debug_file_printer->print_method(phase_name, 0);
5103 }
5104 
5105 void Compile::igv_print_method_to_network(const char* phase_name) {
5106   if (_debug_network_printer == NULL) {
5107     _debug_network_printer = new IdealGraphPrinter(C);
5108   } else {
5109     _debug_network_printer->update_compiled_method(C->method());
5110   }
5111   tty->print_cr("Method printed over network stream to IGV");
5112   _debug_network_printer->print_method(phase_name, 0);
5113 }
5114 #endif
5115