1 /*
   2  * Copyright (c) 1997, 2023, 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 "jvm_io.h"
  40 #include "memory/allocation.hpp"
  41 #include "memory/resourceArea.hpp"
  42 #include "opto/addnode.hpp"
  43 #include "opto/block.hpp"
  44 #include "opto/c2compiler.hpp"
  45 #include "opto/callGenerator.hpp"
  46 #include "opto/callnode.hpp"
  47 #include "opto/castnode.hpp"
  48 #include "opto/cfgnode.hpp"
  49 #include "opto/chaitin.hpp"
  50 #include "opto/compile.hpp"
  51 #include "opto/connode.hpp"
  52 #include "opto/convertnode.hpp"
  53 #include "opto/divnode.hpp"
  54 #include "opto/escape.hpp"
  55 #include "opto/idealGraphPrinter.hpp"
  56 #include "opto/inlinetypenode.hpp"
  57 #include "opto/loopnode.hpp"
  58 #include "opto/machnode.hpp"
  59 #include "opto/macro.hpp"
  60 #include "opto/matcher.hpp"
  61 #include "opto/mathexactnode.hpp"
  62 #include "opto/memnode.hpp"
  63 #include "opto/mulnode.hpp"
  64 #include "opto/narrowptrnode.hpp"
  65 #include "opto/node.hpp"
  66 #include "opto/opcodes.hpp"
  67 #include "opto/output.hpp"
  68 #include "opto/parse.hpp"
  69 #include "opto/phaseX.hpp"
  70 #include "opto/rootnode.hpp"
  71 #include "opto/runtime.hpp"
  72 #include "opto/stringopts.hpp"
  73 #include "opto/type.hpp"
  74 #include "opto/vector.hpp"
  75 #include "opto/vectornode.hpp"
  76 #include "runtime/globals_extension.hpp"
  77 #include "runtime/sharedRuntime.hpp"
  78 #include "runtime/signature.hpp"
  79 #include "runtime/stubRoutines.hpp"
  80 #include "runtime/timer.hpp"
  81 #include "utilities/align.hpp"
  82 #include "utilities/copy.hpp"
  83 #include "utilities/macros.hpp"
  84 #include "utilities/resourceHash.hpp"
  85 
  86 // -------------------- Compile::mach_constant_base_node -----------------------
  87 // Constant table base node singleton.
  88 MachConstantBaseNode* Compile::mach_constant_base_node() {
  89   if (_mach_constant_base_node == nullptr) {
  90     _mach_constant_base_node = new MachConstantBaseNode();
  91     _mach_constant_base_node->add_req(C->root());
  92   }
  93   return _mach_constant_base_node;
  94 }
  95 
  96 
  97 /// Support for intrinsics.
  98 
  99 // Return the index at which m must be inserted (or already exists).
 100 // The sort order is by the address of the ciMethod, with is_virtual as minor key.
 101 class IntrinsicDescPair {
 102  private:
 103   ciMethod* _m;
 104   bool _is_virtual;
 105  public:
 106   IntrinsicDescPair(ciMethod* m, bool is_virtual) : _m(m), _is_virtual(is_virtual) {}
 107   static int compare(IntrinsicDescPair* const& key, CallGenerator* const& elt) {
 108     ciMethod* m= elt->method();
 109     ciMethod* key_m = key->_m;
 110     if (key_m < m)      return -1;
 111     else if (key_m > m) return 1;
 112     else {
 113       bool is_virtual = elt->is_virtual();
 114       bool key_virtual = key->_is_virtual;
 115       if (key_virtual < is_virtual)      return -1;
 116       else if (key_virtual > is_virtual) return 1;
 117       else                               return 0;
 118     }
 119   }
 120 };
 121 int Compile::intrinsic_insertion_index(ciMethod* m, bool is_virtual, bool& found) {
 122 #ifdef ASSERT
 123   for (int i = 1; i < _intrinsics.length(); i++) {
 124     CallGenerator* cg1 = _intrinsics.at(i-1);
 125     CallGenerator* cg2 = _intrinsics.at(i);
 126     assert(cg1->method() != cg2->method()
 127            ? cg1->method()     < cg2->method()
 128            : cg1->is_virtual() < cg2->is_virtual(),
 129            "compiler intrinsics list must stay sorted");
 130   }
 131 #endif
 132   IntrinsicDescPair pair(m, is_virtual);
 133   return _intrinsics.find_sorted<IntrinsicDescPair*, IntrinsicDescPair::compare>(&pair, found);
 134 }
 135 
 136 void Compile::register_intrinsic(CallGenerator* cg) {
 137   bool found = false;
 138   int index = intrinsic_insertion_index(cg->method(), cg->is_virtual(), found);
 139   assert(!found, "registering twice");
 140   _intrinsics.insert_before(index, cg);
 141   assert(find_intrinsic(cg->method(), cg->is_virtual()) == cg, "registration worked");
 142 }
 143 
 144 CallGenerator* Compile::find_intrinsic(ciMethod* m, bool is_virtual) {
 145   assert(m->is_loaded(), "don't try this on unloaded methods");
 146   if (_intrinsics.length() > 0) {
 147     bool found = false;
 148     int index = intrinsic_insertion_index(m, is_virtual, found);
 149      if (found) {
 150       return _intrinsics.at(index);
 151     }
 152   }
 153   // Lazily create intrinsics for intrinsic IDs well-known in the runtime.
 154   if (m->intrinsic_id() != vmIntrinsics::_none &&
 155       m->intrinsic_id() <= vmIntrinsics::LAST_COMPILER_INLINE) {
 156     CallGenerator* cg = make_vm_intrinsic(m, is_virtual);
 157     if (cg != nullptr) {
 158       // Save it for next time:
 159       register_intrinsic(cg);
 160       return cg;
 161     } else {
 162       gather_intrinsic_statistics(m->intrinsic_id(), is_virtual, _intrinsic_disabled);
 163     }
 164   }
 165   return nullptr;
 166 }
 167 
 168 // Compile::make_vm_intrinsic is defined in library_call.cpp.
 169 
 170 #ifndef PRODUCT
 171 // statistics gathering...
 172 
 173 juint  Compile::_intrinsic_hist_count[vmIntrinsics::number_of_intrinsics()] = {0};
 174 jubyte Compile::_intrinsic_hist_flags[vmIntrinsics::number_of_intrinsics()] = {0};
 175 
 176 inline int as_int(vmIntrinsics::ID id) {
 177   return vmIntrinsics::as_int(id);
 178 }
 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[as_int(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[as_int(id)] += 1);
 190     if (count == 1) {
 191       changed = true;           // first time
 192     }
 193     // increment the overall count also:
 194     _intrinsic_hist_count[as_int(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[as_int(id)] = (jubyte) (oflags | flags);
 211   }
 212   // update the overall flags also:
 213   _intrinsic_hist_flags[as_int(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 != nullptr)  xtty->head("statistics type='intrinsic'");
 233   tty->print_cr("Compiler intrinsic usage:");
 234   juint total = _intrinsic_hist_count[as_int(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 (auto id : EnumRange<vmIntrinsicID>{}) {
 239     int   flags = _intrinsic_hist_flags[as_int(id)];
 240     juint count = _intrinsic_hist_count[as_int(id)];
 241     if ((flags | count) != 0) {
 242       PRINT_STAT_LINE(vmIntrinsics::name_at(id), count, format_flags(flags, flagsbuf));
 243     }
 244   }
 245   PRINT_STAT_LINE("total", total, format_flags(_intrinsic_hist_flags[as_int(vmIntrinsics::_none)], flagsbuf));
 246   if (xtty != nullptr)  xtty->tail("statistics");
 247 }
 248 
 249 void Compile::print_statistics() {
 250   { ttyLocker ttyl;
 251     if (xtty != nullptr)  xtty->head("statistics type='opto'");
 252     Parse::print_statistics();
 253     PhaseStringOpts::print_statistics();
 254     PhaseCCP::print_statistics();
 255     PhaseRegAlloc::print_statistics();
 256     PhaseOutput::print_statistics();
 257     PhasePeephole::print_statistics();
 258     PhaseIdealLoop::print_statistics();
 259     ConnectionGraph::print_statistics();
 260     PhaseMacroExpand::print_statistics();
 261     if (xtty != nullptr)  xtty->tail("statistics");
 262   }
 263   if (_intrinsic_hist_flags[as_int(vmIntrinsics::_none)] != 0) {
 264     // put this under its own <statistics> element.
 265     print_intrinsic_statistics();
 266   }
 267 }
 268 #endif //PRODUCT
 269 
 270 void Compile::gvn_replace_by(Node* n, Node* nn) {
 271   for (DUIterator_Last imin, i = n->last_outs(imin); i >= imin; ) {
 272     Node* use = n->last_out(i);
 273     bool is_in_table = initial_gvn()->hash_delete(use);
 274     uint uses_found = 0;
 275     for (uint j = 0; j < use->len(); j++) {
 276       if (use->in(j) == n) {
 277         if (j < use->req())
 278           use->set_req(j, nn);
 279         else
 280           use->set_prec(j, nn);
 281         uses_found++;
 282       }
 283     }
 284     if (is_in_table) {
 285       // reinsert into table
 286       initial_gvn()->hash_find_insert(use);
 287     }
 288     record_for_igvn(use);
 289     i -= uses_found;    // we deleted 1 or more copies of this edge
 290   }
 291 }
 292 
 293 
 294 // Identify all nodes that are reachable from below, useful.
 295 // Use breadth-first pass that records state in a Unique_Node_List,
 296 // recursive traversal is slower.
 297 void Compile::identify_useful_nodes(Unique_Node_List &useful) {
 298   int estimated_worklist_size = live_nodes();
 299   useful.map( estimated_worklist_size, nullptr );  // preallocate space
 300 
 301   // Initialize worklist
 302   if (root() != nullptr)  { useful.push(root()); }
 303   // If 'top' is cached, declare it useful to preserve cached node
 304   if (cached_top_node())  { useful.push(cached_top_node()); }
 305 
 306   // Push all useful nodes onto the list, breadthfirst
 307   for( uint next = 0; next < useful.size(); ++next ) {
 308     assert( next < unique(), "Unique useful nodes < total nodes");
 309     Node *n  = useful.at(next);
 310     uint max = n->len();
 311     for( uint i = 0; i < max; ++i ) {
 312       Node *m = n->in(i);
 313       if (not_a_node(m))  continue;
 314       useful.push(m);
 315     }
 316   }
 317 }
 318 
 319 // Update dead_node_list with any missing dead nodes using useful
 320 // list. Consider all non-useful nodes to be useless i.e., dead nodes.
 321 void Compile::update_dead_node_list(Unique_Node_List &useful) {
 322   uint max_idx = unique();
 323   VectorSet& useful_node_set = useful.member_set();
 324 
 325   for (uint node_idx = 0; node_idx < max_idx; node_idx++) {
 326     // If node with index node_idx is not in useful set,
 327     // mark it as dead in dead node list.
 328     if (!useful_node_set.test(node_idx)) {
 329       record_dead_node(node_idx);
 330     }
 331   }
 332 }
 333 
 334 void Compile::remove_useless_late_inlines(GrowableArray<CallGenerator*>* inlines, Unique_Node_List &useful) {
 335   int shift = 0;
 336   for (int i = 0; i < inlines->length(); i++) {
 337     CallGenerator* cg = inlines->at(i);
 338     if (useful.member(cg->call_node())) {
 339       if (shift > 0) {
 340         inlines->at_put(i - shift, cg);
 341       }
 342     } else {
 343       shift++; // skip over the dead element
 344     }
 345   }
 346   if (shift > 0) {
 347     inlines->trunc_to(inlines->length() - shift); // remove last elements from compacted array
 348   }
 349 }
 350 
 351 void Compile::remove_useless_late_inlines(GrowableArray<CallGenerator*>* inlines, Node* dead) {
 352   assert(dead != nullptr && dead->is_Call(), "sanity");
 353   int found = 0;
 354   for (int i = 0; i < inlines->length(); i++) {
 355     if (inlines->at(i)->call_node() == dead) {
 356       inlines->remove_at(i);
 357       found++;
 358       NOT_DEBUG( break; ) // elements are unique, so exit early
 359     }
 360   }
 361   assert(found <= 1, "not unique");
 362 }
 363 
 364 void Compile::remove_useless_nodes(GrowableArray<Node*>& node_list, Unique_Node_List& useful) {
 365   for (int i = node_list.length() - 1; i >= 0; i--) {
 366     Node* n = node_list.at(i);
 367     if (!useful.member(n)) {
 368       node_list.delete_at(i); // replaces i-th with last element which is known to be useful (already processed)
 369     }
 370   }
 371 }
 372 
 373 void Compile::remove_useless_node(Node* dead) {
 374   remove_modified_node(dead);
 375 
 376   // Constant node that has no out-edges and has only one in-edge from
 377   // root is usually dead. However, sometimes reshaping walk makes
 378   // it reachable by adding use edges. So, we will NOT count Con nodes
 379   // as dead to be conservative about the dead node count at any
 380   // given time.
 381   if (!dead->is_Con()) {
 382     record_dead_node(dead->_idx);
 383   }
 384   if (dead->is_macro()) {
 385     remove_macro_node(dead);
 386   }
 387   if (dead->is_expensive()) {
 388     remove_expensive_node(dead);
 389   }
 390   if (dead->Opcode() == Op_Opaque4) {
 391     remove_template_assertion_predicate_opaq(dead);
 392   }
 393   if (dead->for_post_loop_opts_igvn()) {
 394     remove_from_post_loop_opts_igvn(dead);
 395   }
 396   if (dead->is_InlineType()) {
 397     remove_inline_type(dead);
 398   }
 399   if (dead->is_Call()) {
 400     remove_useless_late_inlines(                &_late_inlines, dead);
 401     remove_useless_late_inlines(         &_string_late_inlines, dead);
 402     remove_useless_late_inlines(         &_boxing_late_inlines, dead);
 403     remove_useless_late_inlines(&_vector_reboxing_late_inlines, dead);
 404 
 405     if (dead->is_CallStaticJava()) {
 406       remove_unstable_if_trap(dead->as_CallStaticJava(), false);
 407     }
 408   }
 409   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 410   bs->unregister_potential_barrier_node(dead);
 411 }
 412 
 413 // Disconnect all useless nodes by disconnecting those at the boundary.
 414 void Compile::disconnect_useless_nodes(Unique_Node_List& useful, Unique_Node_List& worklist) {
 415   uint next = 0;
 416   while (next < useful.size()) {
 417     Node *n = useful.at(next++);
 418     if (n->is_SafePoint()) {
 419       // We're done with a parsing phase. Replaced nodes are not valid
 420       // beyond that point.
 421       n->as_SafePoint()->delete_replaced_nodes();
 422     }
 423     // Use raw traversal of out edges since this code removes out edges
 424     int max = n->outcnt();
 425     for (int j = 0; j < max; ++j) {
 426       Node* child = n->raw_out(j);
 427       if (!useful.member(child)) {
 428         assert(!child->is_top() || child != top(),
 429                "If top is cached in Compile object it is in useful list");
 430         // Only need to remove this out-edge to the useless node
 431         n->raw_del_out(j);
 432         --j;
 433         --max;
 434       }
 435     }
 436     if (n->outcnt() == 1 && n->has_special_unique_user()) {
 437       assert(useful.member(n->unique_out()), "do not push a useless node");
 438       worklist.push(n->unique_out());
 439     }
 440     if (n->outcnt() == 0) {
 441       worklist.push(n);
 442     }
 443   }
 444 
 445   remove_useless_nodes(_macro_nodes,        useful); // remove useless macro nodes
 446   remove_useless_nodes(_parse_predicate_opaqs, useful); // remove useless Parse Predicate opaque nodes
 447   remove_useless_nodes(_template_assertion_predicate_opaqs, useful); // remove useless Assertion Predicate opaque nodes
 448   remove_useless_nodes(_expensive_nodes,    useful); // remove useless expensive nodes
 449   remove_useless_nodes(_for_post_loop_igvn, useful); // remove useless node recorded for post loop opts IGVN pass
 450   remove_useless_nodes(_inline_type_nodes,  useful); // remove useless inline type nodes
 451 #ifdef ASSERT
 452   if (_modified_nodes != nullptr) {
 453     _modified_nodes->remove_useless_nodes(useful.member_set());
 454   }
 455 #endif
 456   remove_useless_unstable_if_traps(useful);          // remove useless unstable_if traps
 457   remove_useless_coarsened_locks(useful);            // remove useless coarsened locks nodes
 458 #ifdef ASSERT
 459   if (_modified_nodes != nullptr) {
 460     _modified_nodes->remove_useless_nodes(useful.member_set());
 461   }
 462 #endif
 463 
 464   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 465   bs->eliminate_useless_gc_barriers(useful, this);
 466   // clean up the late inline lists
 467   remove_useless_late_inlines(                &_late_inlines, useful);
 468   remove_useless_late_inlines(         &_string_late_inlines, useful);
 469   remove_useless_late_inlines(         &_boxing_late_inlines, useful);
 470   remove_useless_late_inlines(&_vector_reboxing_late_inlines, useful);
 471   debug_only(verify_graph_edges(true/*check for no_dead_code*/);)
 472 }
 473 
 474 // ============================================================================
 475 //------------------------------CompileWrapper---------------------------------
 476 class CompileWrapper : public StackObj {
 477   Compile *const _compile;
 478  public:
 479   CompileWrapper(Compile* compile);
 480 
 481   ~CompileWrapper();
 482 };
 483 
 484 CompileWrapper::CompileWrapper(Compile* compile) : _compile(compile) {
 485   // the Compile* pointer is stored in the current ciEnv:
 486   ciEnv* env = compile->env();
 487   assert(env == ciEnv::current(), "must already be a ciEnv active");
 488   assert(env->compiler_data() == nullptr, "compile already active?");
 489   env->set_compiler_data(compile);
 490   assert(compile == Compile::current(), "sanity");
 491 
 492   compile->set_type_dict(nullptr);
 493   compile->set_clone_map(new Dict(cmpkey, hashkey, _compile->comp_arena()));
 494   compile->clone_map().set_clone_idx(0);
 495   compile->set_type_last_size(0);
 496   compile->set_last_tf(nullptr, nullptr);
 497   compile->set_indexSet_arena(nullptr);
 498   compile->set_indexSet_free_block_list(nullptr);
 499   compile->init_type_arena();
 500   Type::Initialize(compile);
 501   _compile->begin_method();
 502   _compile->clone_map().set_debug(_compile->has_method() && _compile->directive()->CloneMapDebugOption);
 503 }
 504 CompileWrapper::~CompileWrapper() {
 505   // simulate crash during compilation
 506   assert(CICrashAt < 0 || _compile->compile_id() != CICrashAt, "just as planned");
 507 
 508   _compile->end_method();
 509   _compile->env()->set_compiler_data(nullptr);
 510 }
 511 
 512 
 513 //----------------------------print_compile_messages---------------------------
 514 void Compile::print_compile_messages() {
 515 #ifndef PRODUCT
 516   // Check if recompiling
 517   if (!subsume_loads() && PrintOpto) {
 518     // Recompiling without allowing machine instructions to subsume loads
 519     tty->print_cr("*********************************************************");
 520     tty->print_cr("** Bailout: Recompile without subsuming loads          **");
 521     tty->print_cr("*********************************************************");
 522   }
 523   if ((do_escape_analysis() != DoEscapeAnalysis) && PrintOpto) {
 524     // Recompiling without escape analysis
 525     tty->print_cr("*********************************************************");
 526     tty->print_cr("** Bailout: Recompile without escape analysis          **");
 527     tty->print_cr("*********************************************************");
 528   }
 529   if (do_iterative_escape_analysis() != DoEscapeAnalysis && PrintOpto) {
 530     // Recompiling without iterative escape analysis
 531     tty->print_cr("*********************************************************");
 532     tty->print_cr("** Bailout: Recompile without iterative escape analysis**");
 533     tty->print_cr("*********************************************************");
 534   }
 535   if (do_reduce_allocation_merges() != ReduceAllocationMerges && PrintOpto) {
 536     // Recompiling without reducing allocation merges
 537     tty->print_cr("*********************************************************");
 538     tty->print_cr("** Bailout: Recompile without reduce allocation merges **");
 539     tty->print_cr("*********************************************************");
 540   }
 541   if ((eliminate_boxing() != EliminateAutoBox) && PrintOpto) {
 542     // Recompiling without boxing elimination
 543     tty->print_cr("*********************************************************");
 544     tty->print_cr("** Bailout: Recompile without boxing elimination       **");
 545     tty->print_cr("*********************************************************");
 546   }
 547   if ((do_locks_coarsening() != EliminateLocks) && PrintOpto) {
 548     // Recompiling without locks coarsening
 549     tty->print_cr("*********************************************************");
 550     tty->print_cr("** Bailout: Recompile without locks coarsening         **");
 551     tty->print_cr("*********************************************************");
 552   }
 553   if (env()->break_at_compile()) {
 554     // Open the debugger when compiling this method.
 555     tty->print("### Breaking when compiling: ");
 556     method()->print_short_name();
 557     tty->cr();
 558     BREAKPOINT;
 559   }
 560 
 561   if( PrintOpto ) {
 562     if (is_osr_compilation()) {
 563       tty->print("[OSR]%3d", _compile_id);
 564     } else {
 565       tty->print("%3d", _compile_id);
 566     }
 567   }
 568 #endif
 569 }
 570 
 571 #ifndef PRODUCT
 572 void Compile::print_ideal_ir(const char* phase_name) {
 573   // keep the following output all in one block
 574   // This output goes directly to the tty, not the compiler log.
 575   // To enable tools to match it up with the compilation activity,
 576   // be sure to tag this tty output with the compile ID.
 577 
 578   // Node dumping can cause a safepoint, which can break the tty lock.
 579   // Buffer all node dumps, so that all safepoints happen before we lock.
 580   ResourceMark rm;
 581   stringStream ss;
 582 
 583   if (_output == nullptr) {
 584     ss.print_cr("AFTER: %s", phase_name);
 585     // Print out all nodes in ascending order of index.
 586     root()->dump_bfs(MaxNodeLimit, nullptr, "+S$", &ss);
 587   } else {
 588     // Dump the node blockwise if we have a scheduling
 589     _output->print_scheduling(&ss);
 590   }
 591 
 592   // Check that the lock is not broken by a safepoint.
 593   NoSafepointVerifier nsv;
 594   ttyLocker ttyl;
 595   if (xtty != nullptr) {
 596     xtty->head("ideal compile_id='%d'%s compile_phase='%s'",
 597                compile_id(),
 598                is_osr_compilation() ? " compile_kind='osr'" : "",
 599                phase_name);
 600     xtty->print("%s", ss.as_string()); // print to tty would use xml escape encoding
 601     xtty->tail("ideal");
 602   } else {
 603     tty->print("%s", ss.as_string());
 604   }
 605 }
 606 #endif
 607 
 608 // ============================================================================
 609 //------------------------------Compile standard-------------------------------
 610 
 611 // Compile a method.  entry_bci is -1 for normal compilations and indicates
 612 // the continuation bci for on stack replacement.
 613 
 614 
 615 Compile::Compile( ciEnv* ci_env, ciMethod* target, int osr_bci,
 616                   Options options, DirectiveSet* directive)
 617                 : Phase(Compiler),
 618                   _compile_id(ci_env->compile_id()),
 619                   _options(options),
 620                   _method(target),
 621                   _entry_bci(osr_bci),
 622                   _ilt(nullptr),
 623                   _stub_function(nullptr),
 624                   _stub_name(nullptr),
 625                   _stub_entry_point(nullptr),
 626                   _max_node_limit(MaxNodeLimit),
 627                   _post_loop_opts_phase(false),
 628                   _inlining_progress(false),
 629                   _inlining_incrementally(false),
 630                   _do_cleanup(false),
 631                   _has_reserved_stack_access(target->has_reserved_stack_access()),
 632                   _has_circular_inline_type(false),
 633 #ifndef PRODUCT
 634                   _igv_idx(0),
 635                   _trace_opto_output(directive->TraceOptoOutputOption),
 636 #endif
 637                   _has_method_handle_invokes(false),
 638                   _clinit_barrier_on_entry(false),
 639                   _stress_seed(0),
 640                   _comp_arena(mtCompiler),
 641                   _barrier_set_state(BarrierSet::barrier_set()->barrier_set_c2()->create_barrier_state(comp_arena())),
 642                   _env(ci_env),
 643                   _directive(directive),
 644                   _log(ci_env->log()),
 645                   _failure_reason(nullptr),
 646                   _intrinsics        (comp_arena(), 0, 0, nullptr),
 647                   _macro_nodes       (comp_arena(), 8, 0, nullptr),
 648                   _parse_predicate_opaqs (comp_arena(), 8, 0, nullptr),
 649                   _template_assertion_predicate_opaqs (comp_arena(), 8, 0, nullptr),
 650                   _expensive_nodes   (comp_arena(), 8, 0, nullptr),
 651                   _for_post_loop_igvn(comp_arena(), 8, 0, nullptr),
 652                   _inline_type_nodes (comp_arena(), 8, 0, nullptr),
 653                   _unstable_if_traps (comp_arena(), 8, 0, nullptr),
 654                   _coarsened_locks   (comp_arena(), 8, 0, nullptr),
 655                   _congraph(nullptr),
 656                   NOT_PRODUCT(_igv_printer(nullptr) COMMA)
 657                   _unique(0),
 658                   _dead_node_count(0),
 659                   _dead_node_list(comp_arena()),
 660                   _node_arena_one(mtCompiler),
 661                   _node_arena_two(mtCompiler),
 662                   _node_arena(&_node_arena_one),
 663                   _mach_constant_base_node(nullptr),
 664                   _Compile_types(mtCompiler),
 665                   _initial_gvn(nullptr),
 666                   _igvn_worklist(nullptr),
 667                   _types(nullptr),
 668                   _node_hash(nullptr),
 669                   _late_inlines(comp_arena(), 2, 0, nullptr),
 670                   _string_late_inlines(comp_arena(), 2, 0, nullptr),
 671                   _boxing_late_inlines(comp_arena(), 2, 0, nullptr),
 672                   _vector_reboxing_late_inlines(comp_arena(), 2, 0, nullptr),
 673                   _late_inlines_pos(0),
 674                   _number_of_mh_late_inlines(0),
 675                   _print_inlining_stream(new (mtCompiler) stringStream()),
 676                   _print_inlining_list(nullptr),
 677                   _print_inlining_idx(0),
 678                   _print_inlining_output(nullptr),
 679                   _replay_inline_data(nullptr),
 680                   _java_calls(0),
 681                   _inner_loops(0),
 682                   _interpreter_frame_size(0),
 683                   _output(nullptr)
 684 #ifndef PRODUCT
 685                   , _in_dump_cnt(0)
 686 #endif
 687 {
 688   C = this;
 689   CompileWrapper cw(this);
 690 
 691   TraceTime t1("Total compilation time", &_t_totalCompilation, CITime, CITimeVerbose);
 692   TraceTime t2(nullptr, &_t_methodCompilation, CITime, false);
 693 
 694 #if defined(SUPPORT_ASSEMBLY) || defined(SUPPORT_ABSTRACT_ASSEMBLY)
 695   bool print_opto_assembly = directive->PrintOptoAssemblyOption;
 696   // We can always print a disassembly, either abstract (hex dump) or
 697   // with the help of a suitable hsdis library. Thus, we should not
 698   // couple print_assembly and print_opto_assembly controls.
 699   // But: always print opto and regular assembly on compile command 'print'.
 700   bool print_assembly = directive->PrintAssemblyOption;
 701   set_print_assembly(print_opto_assembly || print_assembly);
 702 #else
 703   set_print_assembly(false); // must initialize.
 704 #endif
 705 
 706 #ifndef PRODUCT
 707   set_parsed_irreducible_loop(false);
 708 #endif
 709 
 710   if (directive->ReplayInlineOption) {
 711     _replay_inline_data = ciReplay::load_inline_data(method(), entry_bci(), ci_env->comp_level());
 712   }
 713   set_print_inlining(directive->PrintInliningOption || PrintOptoInlining);
 714   set_print_intrinsics(directive->PrintIntrinsicsOption);
 715   set_has_irreducible_loop(true); // conservative until build_loop_tree() reset it
 716 
 717   if (ProfileTraps RTM_OPT_ONLY( || UseRTMLocking )) {
 718     // Make sure the method being compiled gets its own MDO,
 719     // so we can at least track the decompile_count().
 720     // Need MDO to record RTM code generation state.
 721     method()->ensure_method_data();
 722   }
 723 
 724   Init(/*do_aliasing=*/ true);
 725 
 726   print_compile_messages();
 727 
 728   _ilt = InlineTree::build_inline_tree_root();
 729 
 730   // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
 731   assert(num_alias_types() >= AliasIdxRaw, "");
 732 
 733 #define MINIMUM_NODE_HASH  1023
 734 
 735   // GVN that will be run immediately on new nodes
 736   uint estimated_size = method()->code_size()*4+64;
 737   estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
 738   _igvn_worklist = new (comp_arena()) Unique_Node_List(comp_arena());
 739   _types = new (comp_arena()) Type_Array(comp_arena());
 740   _node_hash = new (comp_arena()) NodeHash(comp_arena(), estimated_size);
 741   PhaseGVN gvn;
 742   set_initial_gvn(&gvn);
 743 
 744   print_inlining_init();
 745   { // Scope for timing the parser
 746     TracePhase tp("parse", &timers[_t_parser]);
 747 
 748     // Put top into the hash table ASAP.
 749     initial_gvn()->transform_no_reclaim(top());
 750 
 751     // Set up tf(), start(), and find a CallGenerator.
 752     CallGenerator* cg = nullptr;
 753     if (is_osr_compilation()) {
 754       init_tf(TypeFunc::make(method(), /* is_osr_compilation = */ true));
 755       StartNode* s = new StartOSRNode(root(), tf()->domain_sig());
 756       initial_gvn()->set_type_bottom(s);
 757       init_start(s);
 758       cg = CallGenerator::for_osr(method(), entry_bci());
 759     } else {
 760       // Normal case.
 761       init_tf(TypeFunc::make(method()));
 762       StartNode* s = new StartNode(root(), tf()->domain_cc());
 763       initial_gvn()->set_type_bottom(s);
 764       init_start(s);
 765       if (method()->intrinsic_id() == vmIntrinsics::_Reference_get) {
 766         // With java.lang.ref.reference.get() we must go through the
 767         // intrinsic - even when get() is the root
 768         // method of the compile - so that, if necessary, the value in
 769         // the referent field of the reference object gets recorded by
 770         // the pre-barrier code.
 771         cg = find_intrinsic(method(), false);
 772       }
 773       if (cg == nullptr) {
 774         float past_uses = method()->interpreter_invocation_count();
 775         float expected_uses = past_uses;
 776         cg = CallGenerator::for_inline(method(), expected_uses);
 777       }
 778     }
 779     if (failing())  return;
 780     if (cg == nullptr) {
 781       const char* reason = InlineTree::check_can_parse(method());
 782       assert(reason != nullptr, "expect reason for parse failure");
 783       stringStream ss;
 784       ss.print("cannot parse method: %s", reason);
 785       record_method_not_compilable(ss.as_string());
 786       return;
 787     }
 788 
 789     gvn.set_type(root(), root()->bottom_type());
 790 
 791     JVMState* jvms = build_start_state(start(), tf());
 792     if ((jvms = cg->generate(jvms)) == nullptr) {
 793       assert(failure_reason() != nullptr, "expect reason for parse failure");
 794       stringStream ss;
 795       ss.print("method parse failed: %s", failure_reason());
 796       record_method_not_compilable(ss.as_string());
 797       return;
 798     }
 799     GraphKit kit(jvms);
 800 
 801     if (!kit.stopped()) {
 802       // Accept return values, and transfer control we know not where.
 803       // This is done by a special, unique ReturnNode bound to root.
 804       return_values(kit.jvms());
 805     }
 806 
 807     if (kit.has_exceptions()) {
 808       // Any exceptions that escape from this call must be rethrown
 809       // to whatever caller is dynamically above us on the stack.
 810       // This is done by a special, unique RethrowNode bound to root.
 811       rethrow_exceptions(kit.transfer_exceptions_into_jvms());
 812     }
 813 
 814     assert(IncrementalInline || (_late_inlines.length() == 0 && !has_mh_late_inlines()), "incremental inlining is off");
 815 
 816     if (_late_inlines.length() == 0 && !has_mh_late_inlines() && !failing() && has_stringbuilder()) {
 817       inline_string_calls(true);
 818     }
 819 
 820     if (failing())  return;
 821 
 822     print_method(PHASE_BEFORE_REMOVEUSELESS, 3);
 823 
 824     // Remove clutter produced by parsing.
 825     if (!failing()) {
 826       ResourceMark rm;
 827       PhaseRemoveUseless pru(initial_gvn(), *igvn_worklist());
 828     }
 829   }
 830 
 831   // Note:  Large methods are capped off in do_one_bytecode().
 832   if (failing())  return;
 833 
 834   // After parsing, node notes are no longer automagic.
 835   // They must be propagated by register_new_node_with_optimizer(),
 836   // clone(), or the like.
 837   set_default_node_notes(nullptr);
 838 
 839 #ifndef PRODUCT
 840   if (should_print_igv(1)) {
 841     _igv_printer->print_inlining();
 842   }
 843 #endif
 844 
 845   if (failing())  return;
 846   NOT_PRODUCT( verify_graph_edges(); )
 847 
 848   // If any phase is randomized for stress testing, seed random number
 849   // generation and log the seed for repeatability.
 850   if (StressLCM || StressGCM || StressIGVN || StressCCP) {
 851     if (FLAG_IS_DEFAULT(StressSeed) || (FLAG_IS_ERGO(StressSeed) && directive->RepeatCompilationOption)) {
 852       _stress_seed = static_cast<uint>(Ticks::now().nanoseconds());
 853       FLAG_SET_ERGO(StressSeed, _stress_seed);
 854     } else {
 855       _stress_seed = StressSeed;
 856     }
 857     if (_log != nullptr) {
 858       _log->elem("stress_test seed='%u'", _stress_seed);
 859     }
 860   }
 861 
 862   // Now optimize
 863   Optimize();
 864   if (failing())  return;
 865   NOT_PRODUCT( verify_graph_edges(); )
 866 
 867 #ifndef PRODUCT
 868   if (should_print_ideal()) {
 869     print_ideal_ir("print_ideal");
 870   }
 871 #endif
 872 
 873 #ifdef ASSERT
 874   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 875   bs->verify_gc_barriers(this, BarrierSetC2::BeforeCodeGen);
 876 #endif
 877 
 878   // Dump compilation data to replay it.
 879   if (directive->DumpReplayOption) {
 880     env()->dump_replay_data(_compile_id);
 881   }
 882   if (directive->DumpInlineOption && (ilt() != nullptr)) {
 883     env()->dump_inline_data(_compile_id);
 884   }
 885 
 886   // Now that we know the size of all the monitors we can add a fixed slot
 887   // for the original deopt pc.
 888   int next_slot = fixed_slots() + (sizeof(address) / VMRegImpl::stack_slot_size);
 889   if (needs_stack_repair()) {
 890     // One extra slot for the special stack increment value
 891     next_slot += 2;
 892   }
 893   // TODO 8284443 Only reserve extra slot if needed
 894   if (InlineTypeReturnedAsFields) {
 895     // One extra slot to hold the IsInit information for a nullable
 896     // inline type return if we run out of registers.
 897     next_slot += 2;
 898   }
 899   set_fixed_slots(next_slot);
 900 
 901   // Compute when to use implicit null checks. Used by matching trap based
 902   // nodes and NullCheck optimization.
 903   set_allowed_deopt_reasons();
 904 
 905   // Now generate code
 906   Code_Gen();
 907 }
 908 
 909 //------------------------------Compile----------------------------------------
 910 // Compile a runtime stub
 911 Compile::Compile( ciEnv* ci_env,
 912                   TypeFunc_generator generator,
 913                   address stub_function,
 914                   const char *stub_name,
 915                   int is_fancy_jump,
 916                   bool pass_tls,
 917                   bool return_pc,
 918                   DirectiveSet* directive)
 919   : Phase(Compiler),
 920     _compile_id(0),
 921     _options(Options::for_runtime_stub()),
 922     _method(nullptr),
 923     _entry_bci(InvocationEntryBci),
 924     _stub_function(stub_function),
 925     _stub_name(stub_name),
 926     _stub_entry_point(nullptr),
 927     _max_node_limit(MaxNodeLimit),
 928     _post_loop_opts_phase(false),
 929     _inlining_progress(false),
 930     _inlining_incrementally(false),
 931     _has_reserved_stack_access(false),
 932     _has_circular_inline_type(false),
 933 #ifndef PRODUCT
 934     _igv_idx(0),
 935     _trace_opto_output(directive->TraceOptoOutputOption),
 936 #endif
 937     _has_method_handle_invokes(false),
 938     _clinit_barrier_on_entry(false),
 939     _stress_seed(0),
 940     _comp_arena(mtCompiler),
 941     _barrier_set_state(BarrierSet::barrier_set()->barrier_set_c2()->create_barrier_state(comp_arena())),
 942     _env(ci_env),
 943     _directive(directive),
 944     _log(ci_env->log()),
 945     _failure_reason(nullptr),
 946     _congraph(nullptr),
 947     NOT_PRODUCT(_igv_printer(nullptr) COMMA)
 948     _unique(0),
 949     _dead_node_count(0),
 950     _dead_node_list(comp_arena()),
 951     _node_arena_one(mtCompiler),
 952     _node_arena_two(mtCompiler),
 953     _node_arena(&_node_arena_one),
 954     _mach_constant_base_node(nullptr),
 955     _Compile_types(mtCompiler),
 956     _initial_gvn(nullptr),
 957     _igvn_worklist(nullptr),
 958     _types(nullptr),
 959     _node_hash(nullptr),
 960     _number_of_mh_late_inlines(0),
 961     _print_inlining_stream(new (mtCompiler) stringStream()),
 962     _print_inlining_list(nullptr),
 963     _print_inlining_idx(0),
 964     _print_inlining_output(nullptr),
 965     _replay_inline_data(nullptr),
 966     _java_calls(0),
 967     _inner_loops(0),
 968     _interpreter_frame_size(0),
 969     _output(nullptr),
 970 #ifndef PRODUCT
 971     _in_dump_cnt(0),
 972 #endif
 973     _allowed_reasons(0) {
 974   C = this;
 975 
 976   TraceTime t1(nullptr, &_t_totalCompilation, CITime, false);
 977   TraceTime t2(nullptr, &_t_stubCompilation, CITime, false);
 978 
 979 #ifndef PRODUCT
 980   set_print_assembly(PrintFrameConverterAssembly);
 981   set_parsed_irreducible_loop(false);
 982 #else
 983   set_print_assembly(false); // Must initialize.
 984 #endif
 985   set_has_irreducible_loop(false); // no loops
 986 
 987   CompileWrapper cw(this);
 988   Init(/*do_aliasing=*/ false);
 989   init_tf((*generator)());
 990 
 991   _igvn_worklist = new (comp_arena()) Unique_Node_List(comp_arena());
 992   _types = new (comp_arena()) Type_Array(comp_arena());
 993   _node_hash = new (comp_arena()) NodeHash(comp_arena(), 255);
 994   {
 995     PhaseGVN gvn;
 996     set_initial_gvn(&gvn);    // not significant, but GraphKit guys use it pervasively
 997     gvn.transform_no_reclaim(top());
 998 
 999     GraphKit kit;
1000     kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
1001   }
1002 
1003   NOT_PRODUCT( verify_graph_edges(); )
1004 
1005   Code_Gen();
1006 }
1007 
1008 //------------------------------Init-------------------------------------------
1009 // Prepare for a single compilation
1010 void Compile::Init(bool aliasing) {
1011   _do_aliasing = aliasing;
1012   _unique  = 0;
1013   _regalloc = nullptr;
1014 
1015   _tf      = nullptr;  // filled in later
1016   _top     = nullptr;  // cached later
1017   _matcher = nullptr;  // filled in later
1018   _cfg     = nullptr;  // filled in later
1019 
1020   IA32_ONLY( set_24_bit_selection_and_mode(true, false); )
1021 
1022   _node_note_array = nullptr;
1023   _default_node_notes = nullptr;
1024   DEBUG_ONLY( _modified_nodes = nullptr; ) // Used in Optimize()
1025 
1026   _immutable_memory = nullptr; // filled in at first inquiry
1027 
1028 #ifdef ASSERT
1029   _phase_optimize_finished = false;
1030   _exception_backedge = false;
1031   _type_verify = nullptr;
1032 #endif
1033 
1034   // Globally visible Nodes
1035   // First set TOP to null to give safe behavior during creation of RootNode
1036   set_cached_top_node(nullptr);
1037   set_root(new RootNode());
1038   // Now that you have a Root to point to, create the real TOP
1039   set_cached_top_node( new ConNode(Type::TOP) );
1040   set_recent_alloc(nullptr, nullptr);
1041 
1042   // Create Debug Information Recorder to record scopes, oopmaps, etc.
1043   env()->set_oop_recorder(new OopRecorder(env()->arena()));
1044   env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
1045   env()->set_dependencies(new Dependencies(env()));
1046 
1047   _fixed_slots = 0;
1048   set_has_split_ifs(false);
1049   set_has_loops(false); // first approximation
1050   set_has_stringbuilder(false);
1051   set_has_boxed_value(false);
1052   _trap_can_recompile = false;  // no traps emitted yet
1053   _major_progress = true; // start out assuming good things will happen
1054   set_has_unsafe_access(false);
1055   set_max_vector_size(0);
1056   set_clear_upper_avx(false);  //false as default for clear upper bits of ymm registers
1057   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
1058   set_decompile_count(0);
1059 
1060   set_do_freq_based_layout(_directive->BlockLayoutByFrequencyOption);
1061   _loop_opts_cnt = LoopOptsCount;
1062   _has_flat_accesses = false;
1063   _flat_accesses_share_alias = true;
1064   _scalarize_in_safepoints = false;
1065 
1066   set_do_inlining(Inline);
1067   set_max_inline_size(MaxInlineSize);
1068   set_freq_inline_size(FreqInlineSize);
1069   set_do_scheduling(OptoScheduling);
1070 
1071   set_do_vector_loop(false);
1072   set_has_monitors(false);
1073 
1074   if (AllowVectorizeOnDemand) {
1075     if (has_method() && (_directive->VectorizeOption || _directive->VectorizeDebugOption)) {
1076       set_do_vector_loop(true);
1077       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());})
1078     } else if (has_method() && method()->name() != 0 &&
1079                method()->intrinsic_id() == vmIntrinsics::_forEachRemaining) {
1080       set_do_vector_loop(true);
1081     }
1082   }
1083   set_use_cmove(UseCMoveUnconditionally /* || do_vector_loop()*/); //TODO: consider do_vector_loop() mandate use_cmove unconditionally
1084   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());})
1085 
1086   set_rtm_state(NoRTM); // No RTM lock eliding by default
1087   _max_node_limit = _directive->MaxNodeLimitOption;
1088 
1089 #if INCLUDE_RTM_OPT
1090   if (UseRTMLocking && has_method() && (method()->method_data_or_null() != nullptr)) {
1091     int rtm_state = method()->method_data()->rtm_state();
1092     if (method_has_option(CompileCommand::NoRTMLockEliding) || ((rtm_state & NoRTM) != 0)) {
1093       // Don't generate RTM lock eliding code.
1094       set_rtm_state(NoRTM);
1095     } else if (method_has_option(CompileCommand::UseRTMLockEliding) || ((rtm_state & UseRTM) != 0) || !UseRTMDeopt) {
1096       // Generate RTM lock eliding code without abort ratio calculation code.
1097       set_rtm_state(UseRTM);
1098     } else if (UseRTMDeopt) {
1099       // Generate RTM lock eliding code and include abort ratio calculation
1100       // code if UseRTMDeopt is on.
1101       set_rtm_state(ProfileRTM);
1102     }
1103   }
1104 #endif
1105   if (VM_Version::supports_fast_class_init_checks() && has_method() && !is_osr_compilation() && method()->needs_clinit_barrier()) {
1106     set_clinit_barrier_on_entry(true);
1107   }
1108   if (debug_info()->recording_non_safepoints()) {
1109     set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
1110                         (comp_arena(), 8, 0, nullptr));
1111     set_default_node_notes(Node_Notes::make(this));
1112   }
1113 
1114   const int grow_ats = 16;
1115   _max_alias_types = grow_ats;
1116   _alias_types   = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
1117   AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType,  grow_ats);
1118   Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
1119   {
1120     for (int i = 0; i < grow_ats; i++)  _alias_types[i] = &ats[i];
1121   }
1122   // Initialize the first few types.
1123   _alias_types[AliasIdxTop]->Init(AliasIdxTop, nullptr);
1124   _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
1125   _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
1126   _num_alias_types = AliasIdxRaw+1;
1127   // Zero out the alias type cache.
1128   Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
1129   // A null adr_type hits in the cache right away.  Preload the right answer.
1130   probe_alias_cache(nullptr)->_index = AliasIdxTop;
1131 }
1132 
1133 //---------------------------init_start----------------------------------------
1134 // Install the StartNode on this compile object.
1135 void Compile::init_start(StartNode* s) {
1136   if (failing())
1137     return; // already failing
1138   assert(s == start(), "");
1139 }
1140 
1141 /**
1142  * Return the 'StartNode'. We must not have a pending failure, since the ideal graph
1143  * can be in an inconsistent state, i.e., we can get segmentation faults when traversing
1144  * the ideal graph.
1145  */
1146 StartNode* Compile::start() const {
1147   assert (!failing(), "Must not have pending failure. Reason is: %s", failure_reason());
1148   for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
1149     Node* start = root()->fast_out(i);
1150     if (start->is_Start()) {
1151       return start->as_Start();
1152     }
1153   }
1154   fatal("Did not find Start node!");
1155   return nullptr;
1156 }
1157 
1158 //-------------------------------immutable_memory-------------------------------------
1159 // Access immutable memory
1160 Node* Compile::immutable_memory() {
1161   if (_immutable_memory != nullptr) {
1162     return _immutable_memory;
1163   }
1164   StartNode* s = start();
1165   for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
1166     Node *p = s->fast_out(i);
1167     if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
1168       _immutable_memory = p;
1169       return _immutable_memory;
1170     }
1171   }
1172   ShouldNotReachHere();
1173   return nullptr;
1174 }
1175 
1176 //----------------------set_cached_top_node------------------------------------
1177 // Install the cached top node, and make sure Node::is_top works correctly.
1178 void Compile::set_cached_top_node(Node* tn) {
1179   if (tn != nullptr)  verify_top(tn);
1180   Node* old_top = _top;
1181   _top = tn;
1182   // Calling Node::setup_is_top allows the nodes the chance to adjust
1183   // their _out arrays.
1184   if (_top != nullptr)     _top->setup_is_top();
1185   if (old_top != nullptr)  old_top->setup_is_top();
1186   assert(_top == nullptr || top()->is_top(), "");
1187 }
1188 
1189 #ifdef ASSERT
1190 uint Compile::count_live_nodes_by_graph_walk() {
1191   Unique_Node_List useful(comp_arena());
1192   // Get useful node list by walking the graph.
1193   identify_useful_nodes(useful);
1194   return useful.size();
1195 }
1196 
1197 void Compile::print_missing_nodes() {
1198 
1199   // Return if CompileLog is null and PrintIdealNodeCount is false.
1200   if ((_log == nullptr) && (! PrintIdealNodeCount)) {
1201     return;
1202   }
1203 
1204   // This is an expensive function. It is executed only when the user
1205   // specifies VerifyIdealNodeCount option or otherwise knows the
1206   // additional work that needs to be done to identify reachable nodes
1207   // by walking the flow graph and find the missing ones using
1208   // _dead_node_list.
1209 
1210   Unique_Node_List useful(comp_arena());
1211   // Get useful node list by walking the graph.
1212   identify_useful_nodes(useful);
1213 
1214   uint l_nodes = C->live_nodes();
1215   uint l_nodes_by_walk = useful.size();
1216 
1217   if (l_nodes != l_nodes_by_walk) {
1218     if (_log != nullptr) {
1219       _log->begin_head("mismatched_nodes count='%d'", abs((int) (l_nodes - l_nodes_by_walk)));
1220       _log->stamp();
1221       _log->end_head();
1222     }
1223     VectorSet& useful_member_set = useful.member_set();
1224     int last_idx = l_nodes_by_walk;
1225     for (int i = 0; i < last_idx; i++) {
1226       if (useful_member_set.test(i)) {
1227         if (_dead_node_list.test(i)) {
1228           if (_log != nullptr) {
1229             _log->elem("mismatched_node_info node_idx='%d' type='both live and dead'", i);
1230           }
1231           if (PrintIdealNodeCount) {
1232             // Print the log message to tty
1233               tty->print_cr("mismatched_node idx='%d' both live and dead'", i);
1234               useful.at(i)->dump();
1235           }
1236         }
1237       }
1238       else if (! _dead_node_list.test(i)) {
1239         if (_log != nullptr) {
1240           _log->elem("mismatched_node_info node_idx='%d' type='neither live nor dead'", i);
1241         }
1242         if (PrintIdealNodeCount) {
1243           // Print the log message to tty
1244           tty->print_cr("mismatched_node idx='%d' type='neither live nor dead'", i);
1245         }
1246       }
1247     }
1248     if (_log != nullptr) {
1249       _log->tail("mismatched_nodes");
1250     }
1251   }
1252 }
1253 void Compile::record_modified_node(Node* n) {
1254   if (_modified_nodes != nullptr && !_inlining_incrementally && !n->is_Con()) {
1255     _modified_nodes->push(n);
1256   }
1257 }
1258 
1259 void Compile::remove_modified_node(Node* n) {
1260   if (_modified_nodes != nullptr) {
1261     _modified_nodes->remove(n);
1262   }
1263 }
1264 #endif
1265 
1266 #ifndef PRODUCT
1267 void Compile::verify_top(Node* tn) const {
1268   if (tn != nullptr) {
1269     assert(tn->is_Con(), "top node must be a constant");
1270     assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
1271     assert(tn->in(0) != nullptr, "must have live top node");
1272   }
1273 }
1274 #endif
1275 
1276 
1277 ///-------------------Managing Per-Node Debug & Profile Info-------------------
1278 
1279 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
1280   guarantee(arr != nullptr, "");
1281   int num_blocks = arr->length();
1282   if (grow_by < num_blocks)  grow_by = num_blocks;
1283   int num_notes = grow_by * _node_notes_block_size;
1284   Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
1285   Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
1286   while (num_notes > 0) {
1287     arr->append(notes);
1288     notes     += _node_notes_block_size;
1289     num_notes -= _node_notes_block_size;
1290   }
1291   assert(num_notes == 0, "exact multiple, please");
1292 }
1293 
1294 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
1295   if (source == nullptr || dest == nullptr)  return false;
1296 
1297   if (dest->is_Con())
1298     return false;               // Do not push debug info onto constants.
1299 
1300 #ifdef ASSERT
1301   // Leave a bread crumb trail pointing to the original node:
1302   if (dest != nullptr && dest != source && dest->debug_orig() == nullptr) {
1303     dest->set_debug_orig(source);
1304   }
1305 #endif
1306 
1307   if (node_note_array() == nullptr)
1308     return false;               // Not collecting any notes now.
1309 
1310   // This is a copy onto a pre-existing node, which may already have notes.
1311   // If both nodes have notes, do not overwrite any pre-existing notes.
1312   Node_Notes* source_notes = node_notes_at(source->_idx);
1313   if (source_notes == nullptr || source_notes->is_clear())  return false;
1314   Node_Notes* dest_notes   = node_notes_at(dest->_idx);
1315   if (dest_notes == nullptr || dest_notes->is_clear()) {
1316     return set_node_notes_at(dest->_idx, source_notes);
1317   }
1318 
1319   Node_Notes merged_notes = (*source_notes);
1320   // The order of operations here ensures that dest notes will win...
1321   merged_notes.update_from(dest_notes);
1322   return set_node_notes_at(dest->_idx, &merged_notes);
1323 }
1324 
1325 
1326 //--------------------------allow_range_check_smearing-------------------------
1327 // Gating condition for coalescing similar range checks.
1328 // Sometimes we try 'speculatively' replacing a series of a range checks by a
1329 // single covering check that is at least as strong as any of them.
1330 // If the optimization succeeds, the simplified (strengthened) range check
1331 // will always succeed.  If it fails, we will deopt, and then give up
1332 // on the optimization.
1333 bool Compile::allow_range_check_smearing() const {
1334   // If this method has already thrown a range-check,
1335   // assume it was because we already tried range smearing
1336   // and it failed.
1337   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
1338   return !already_trapped;
1339 }
1340 
1341 
1342 //------------------------------flatten_alias_type-----------------------------
1343 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
1344   assert(do_aliasing(), "Aliasing should be enabled");
1345   int offset = tj->offset();
1346   TypePtr::PTR ptr = tj->ptr();
1347 
1348   // Known instance (scalarizable allocation) alias only with itself.
1349   bool is_known_inst = tj->isa_oopptr() != nullptr &&
1350                        tj->is_oopptr()->is_known_instance();
1351 
1352   // Process weird unsafe references.
1353   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
1354     bool default_value_load = EnableValhalla && tj->is_instptr()->instance_klass() == ciEnv::current()->Class_klass();
1355     assert(InlineUnsafeOps || StressReflectiveCode || default_value_load, "indeterminate pointers come only from unsafe ops");
1356     assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
1357     tj = TypeOopPtr::BOTTOM;
1358     ptr = tj->ptr();
1359     offset = tj->offset();
1360   }
1361 
1362   // Array pointers need some flattening
1363   const TypeAryPtr* ta = tj->isa_aryptr();
1364   if (ta && ta->is_stable()) {
1365     // Erase stability property for alias analysis.
1366     tj = ta = ta->cast_to_stable(false);
1367   }
1368   if (ta && ta->is_not_flat()) {
1369     // Erase not flat property for alias analysis.
1370     tj = ta = ta->cast_to_not_flat(false);
1371   }
1372   if (ta && ta->is_not_null_free()) {
1373     // Erase not null free property for alias analysis.
1374     tj = ta = ta->cast_to_not_null_free(false);
1375   }
1376 
1377   if( ta && is_known_inst ) {
1378     if ( offset != Type::OffsetBot &&
1379          offset > arrayOopDesc::length_offset_in_bytes() ) {
1380       offset = Type::OffsetBot; // Flatten constant access into array body only
1381       tj = ta = ta->
1382               remove_speculative()->
1383               cast_to_ptr_type(ptr)->
1384               with_offset(offset);
1385     }
1386   } else if (ta) {
1387     // For arrays indexed by constant indices, we flatten the alias
1388     // space to include all of the array body.  Only the header, klass
1389     // and array length can be accessed un-aliased.
1390     // For flat inline type array, each field has its own slice so
1391     // we must include the field offset.
1392     if( offset != Type::OffsetBot ) {
1393       if( ta->const_oop() ) { // MethodData* or Method*
1394         offset = Type::OffsetBot;   // Flatten constant access into array body
1395         tj = ta = ta->
1396                 remove_speculative()->
1397                 cast_to_ptr_type(ptr)->
1398                 cast_to_exactness(false)->
1399                 with_offset(offset);
1400       } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
1401         // range is OK as-is.
1402         tj = ta = TypeAryPtr::RANGE;
1403       } else if( offset == oopDesc::klass_offset_in_bytes() ) {
1404         tj = TypeInstPtr::KLASS; // all klass loads look alike
1405         ta = TypeAryPtr::RANGE; // generic ignored junk
1406         ptr = TypePtr::BotPTR;
1407       } else if( offset == oopDesc::mark_offset_in_bytes() ) {
1408         tj = TypeInstPtr::MARK;
1409         ta = TypeAryPtr::RANGE; // generic ignored junk
1410         ptr = TypePtr::BotPTR;
1411       } else {                  // Random constant offset into array body
1412         offset = Type::OffsetBot;   // Flatten constant access into array body
1413         tj = ta = ta->
1414                 remove_speculative()->
1415                 cast_to_ptr_type(ptr)->
1416                 cast_to_exactness(false)->
1417                 with_offset(offset);
1418       }
1419     }
1420     // Arrays of fixed size alias with arrays of unknown size.
1421     if (ta->size() != TypeInt::POS) {
1422       const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
1423       tj = ta = ta->
1424               remove_speculative()->
1425               cast_to_ptr_type(ptr)->
1426               with_ary(tary)->
1427               cast_to_exactness(false);
1428     }
1429     // Arrays of known objects become arrays of unknown objects.
1430     if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
1431       const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
1432       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,nullptr,false,Type::Offset(offset), ta->field_offset());
1433     }
1434     if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
1435       const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
1436       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,nullptr,false,Type::Offset(offset), ta->field_offset());
1437     }
1438     // Initially all flattened array accesses share a single slice
1439     if (ta->is_flat() && ta->elem() != TypeInstPtr::BOTTOM && _flat_accesses_share_alias) {
1440       const TypeAry* tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size(), /* stable= */ false, /* flat= */ true);
1441       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,nullptr,false,Type::Offset(offset), Type::Offset(Type::OffsetBot));
1442     }
1443     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
1444     // cannot be distinguished by bytecode alone.
1445     if (ta->elem() == TypeInt::BOOL) {
1446       const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
1447       ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
1448       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,Type::Offset(offset), ta->field_offset());
1449     }
1450     // During the 2nd round of IterGVN, NotNull castings are removed.
1451     // Make sure the Bottom and NotNull variants alias the same.
1452     // Also, make sure exact and non-exact variants alias the same.
1453     if (ptr == TypePtr::NotNull || ta->klass_is_exact() || ta->speculative() != nullptr) {
1454       tj = ta = ta->
1455               remove_speculative()->
1456               cast_to_ptr_type(TypePtr::BotPTR)->
1457               cast_to_exactness(false)->
1458               with_offset(offset);
1459     }
1460   }
1461 
1462   // Oop pointers need some flattening
1463   const TypeInstPtr *to = tj->isa_instptr();
1464   if (to && to != TypeOopPtr::BOTTOM) {
1465     ciInstanceKlass* ik = to->instance_klass();
1466     if( ptr == TypePtr::Constant ) {
1467       if (ik != ciEnv::current()->Class_klass() ||
1468           offset < ik->layout_helper_size_in_bytes()) {
1469         // No constant oop pointers (such as Strings); they alias with
1470         // unknown strings.
1471         assert(!is_known_inst, "not scalarizable allocation");
1472         tj = to = to->
1473                 cast_to_instance_id(TypeOopPtr::InstanceBot)->
1474                 remove_speculative()->
1475                 cast_to_ptr_type(TypePtr::BotPTR)->
1476                 cast_to_exactness(false);
1477       }
1478     } else if( is_known_inst ) {
1479       tj = to; // Keep NotNull and klass_is_exact for instance type
1480     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
1481       // During the 2nd round of IterGVN, NotNull castings are removed.
1482       // Make sure the Bottom and NotNull variants alias the same.
1483       // Also, make sure exact and non-exact variants alias the same.
1484       tj = to = to->
1485               remove_speculative()->
1486               cast_to_instance_id(TypeOopPtr::InstanceBot)->
1487               cast_to_ptr_type(TypePtr::BotPTR)->
1488               cast_to_exactness(false);
1489     }
1490     if (to->speculative() != nullptr) {
1491       tj = to = to->remove_speculative();
1492     }
1493     // Canonicalize the holder of this field
1494     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
1495       // First handle header references such as a LoadKlassNode, even if the
1496       // object's klass is unloaded at compile time (4965979).
1497       if (!is_known_inst) { // Do it only for non-instance types
1498         tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, nullptr, Type::Offset(offset));
1499       }
1500     } else if (offset < 0 || offset >= ik->layout_helper_size_in_bytes()) {
1501       // Static fields are in the space above the normal instance
1502       // fields in the java.lang.Class instance.
1503       if (ik != ciEnv::current()->Class_klass()) {
1504         to = nullptr;
1505         tj = TypeOopPtr::BOTTOM;
1506         offset = tj->offset();
1507       }
1508     } else {
1509       ciInstanceKlass *canonical_holder = ik->get_canonical_holder(offset);
1510       assert(offset < canonical_holder->layout_helper_size_in_bytes(), "");
1511       if (!ik->equals(canonical_holder) || tj->offset() != offset) {
1512         if( is_known_inst ) {
1513           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, true, nullptr, Type::Offset(offset), to->instance_id());
1514         } else {
1515           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, false, nullptr, Type::Offset(offset));
1516         }
1517       }
1518     }
1519   }
1520 
1521   // Klass pointers to object array klasses need some flattening
1522   const TypeKlassPtr *tk = tj->isa_klassptr();
1523   if( tk ) {
1524     // If we are referencing a field within a Klass, we need
1525     // to assume the worst case of an Object.  Both exact and
1526     // inexact types must flatten to the same alias class so
1527     // use NotNull as the PTR.
1528     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
1529       tj = tk = TypeInstKlassPtr::make(TypePtr::NotNull,
1530                                        env()->Object_klass(),
1531                                        Type::Offset(offset));
1532     }
1533 
1534     if (tk->isa_aryklassptr() && tk->is_aryklassptr()->elem()->isa_klassptr()) {
1535       ciKlass* k = ciObjArrayKlass::make(env()->Object_klass());
1536       if (!k || !k->is_loaded()) {                  // Only fails for some -Xcomp runs
1537         tj = tk = TypeInstKlassPtr::make(TypePtr::NotNull, env()->Object_klass(), Type::Offset(offset));
1538       } else {
1539         tj = tk = TypeAryKlassPtr::make(TypePtr::NotNull, tk->is_aryklassptr()->elem(), k, Type::Offset(offset), tk->is_not_flat(), tk->is_not_null_free(), tk->is_null_free());
1540       }
1541     }
1542     // Check for precise loads from the primary supertype array and force them
1543     // to the supertype cache alias index.  Check for generic array loads from
1544     // the primary supertype array and also force them to the supertype cache
1545     // alias index.  Since the same load can reach both, we need to merge
1546     // these 2 disparate memories into the same alias class.  Since the
1547     // primary supertype array is read-only, there's no chance of confusion
1548     // where we bypass an array load and an array store.
1549     int primary_supers_offset = in_bytes(Klass::primary_supers_offset());
1550     if (offset == Type::OffsetBot ||
1551         (offset >= primary_supers_offset &&
1552          offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
1553         offset == (int)in_bytes(Klass::secondary_super_cache_offset())) {
1554       offset = in_bytes(Klass::secondary_super_cache_offset());
1555       tj = tk = tk->with_offset(offset);
1556     }
1557   }
1558 
1559   // Flatten all Raw pointers together.
1560   if (tj->base() == Type::RawPtr)
1561     tj = TypeRawPtr::BOTTOM;
1562 
1563   if (tj->base() == Type::AnyPtr)
1564     tj = TypePtr::BOTTOM;      // An error, which the caller must check for.
1565 
1566   offset = tj->offset();
1567   assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
1568 
1569   assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
1570           (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
1571           (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
1572           (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
1573           (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1574           (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1575           (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr),
1576           "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
1577   assert( tj->ptr() != TypePtr::TopPTR &&
1578           tj->ptr() != TypePtr::AnyNull &&
1579           tj->ptr() != TypePtr::Null, "No imprecise addresses" );
1580 //    assert( tj->ptr() != TypePtr::Constant ||
1581 //            tj->base() == Type::RawPtr ||
1582 //            tj->base() == Type::KlassPtr, "No constant oop addresses" );
1583 
1584   return tj;
1585 }
1586 
1587 void Compile::AliasType::Init(int i, const TypePtr* at) {
1588   assert(AliasIdxTop <= i && i < Compile::current()->_max_alias_types, "Invalid alias index");
1589   _index = i;
1590   _adr_type = at;
1591   _field = nullptr;
1592   _element = nullptr;
1593   _is_rewritable = true; // default
1594   const TypeOopPtr *atoop = (at != nullptr) ? at->isa_oopptr() : nullptr;
1595   if (atoop != nullptr && atoop->is_known_instance()) {
1596     const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
1597     _general_index = Compile::current()->get_alias_index(gt);
1598   } else {
1599     _general_index = 0;
1600   }
1601 }
1602 
1603 BasicType Compile::AliasType::basic_type() const {
1604   if (element() != nullptr) {
1605     const Type* element = adr_type()->is_aryptr()->elem();
1606     return element->isa_narrowoop() ? T_OBJECT : element->array_element_basic_type();
1607   } if (field() != nullptr) {
1608     return field()->layout_type();
1609   } else {
1610     return T_ILLEGAL; // unknown
1611   }
1612 }
1613 
1614 //---------------------------------print_on------------------------------------
1615 #ifndef PRODUCT
1616 void Compile::AliasType::print_on(outputStream* st) {
1617   if (index() < 10)
1618         st->print("@ <%d> ", index());
1619   else  st->print("@ <%d>",  index());
1620   st->print(is_rewritable() ? "   " : " RO");
1621   int offset = adr_type()->offset();
1622   if (offset == Type::OffsetBot)
1623         st->print(" +any");
1624   else  st->print(" +%-3d", offset);
1625   st->print(" in ");
1626   adr_type()->dump_on(st);
1627   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
1628   if (field() != nullptr && tjp) {
1629     if (tjp->is_instptr()->instance_klass()  != field()->holder() ||
1630         tjp->offset() != field()->offset_in_bytes()) {
1631       st->print(" != ");
1632       field()->print();
1633       st->print(" ***");
1634     }
1635   }
1636 }
1637 
1638 void print_alias_types() {
1639   Compile* C = Compile::current();
1640   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
1641   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
1642     C->alias_type(idx)->print_on(tty);
1643     tty->cr();
1644   }
1645 }
1646 #endif
1647 
1648 
1649 //----------------------------probe_alias_cache--------------------------------
1650 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
1651   intptr_t key = (intptr_t) adr_type;
1652   key ^= key >> logAliasCacheSize;
1653   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
1654 }
1655 
1656 
1657 //-----------------------------grow_alias_types--------------------------------
1658 void Compile::grow_alias_types() {
1659   const int old_ats  = _max_alias_types; // how many before?
1660   const int new_ats  = old_ats;          // how many more?
1661   const int grow_ats = old_ats+new_ats;  // how many now?
1662   _max_alias_types = grow_ats;
1663   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
1664   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
1665   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
1666   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
1667 }
1668 
1669 
1670 //--------------------------------find_alias_type------------------------------
1671 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field, bool uncached) {
1672   if (!do_aliasing()) {
1673     return alias_type(AliasIdxBot);
1674   }
1675 
1676   AliasCacheEntry* ace = nullptr;
1677   if (!uncached) {
1678     ace = probe_alias_cache(adr_type);
1679     if (ace->_adr_type == adr_type) {
1680       return alias_type(ace->_index);
1681     }
1682   }
1683 
1684   // Handle special cases.
1685   if (adr_type == nullptr)          return alias_type(AliasIdxTop);
1686   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
1687 
1688   // Do it the slow way.
1689   const TypePtr* flat = flatten_alias_type(adr_type);
1690 
1691 #ifdef ASSERT
1692   {
1693     ResourceMark rm;
1694     assert(flat == flatten_alias_type(flat), "not idempotent: adr_type = %s; flat = %s => %s",
1695            Type::str(adr_type), Type::str(flat), Type::str(flatten_alias_type(flat)));
1696     assert(flat != TypePtr::BOTTOM, "cannot alias-analyze an untyped ptr: adr_type = %s",
1697            Type::str(adr_type));
1698     if (flat->isa_oopptr() && !flat->isa_klassptr()) {
1699       const TypeOopPtr* foop = flat->is_oopptr();
1700       // Scalarizable allocations have exact klass always.
1701       bool exact = !foop->klass_is_exact() || foop->is_known_instance();
1702       const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
1703       assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type: foop = %s; xoop = %s",
1704              Type::str(foop), Type::str(xoop));
1705     }
1706   }
1707 #endif
1708 
1709   int idx = AliasIdxTop;
1710   for (int i = 0; i < num_alias_types(); i++) {
1711     if (alias_type(i)->adr_type() == flat) {
1712       idx = i;
1713       break;
1714     }
1715   }
1716 
1717   if (idx == AliasIdxTop) {
1718     if (no_create)  return nullptr;
1719     // Grow the array if necessary.
1720     if (_num_alias_types == _max_alias_types)  grow_alias_types();
1721     // Add a new alias type.
1722     idx = _num_alias_types++;
1723     _alias_types[idx]->Init(idx, flat);
1724     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
1725     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
1726     if (flat->isa_instptr()) {
1727       if (flat->offset() == java_lang_Class::klass_offset()
1728           && flat->is_instptr()->instance_klass() == env()->Class_klass())
1729         alias_type(idx)->set_rewritable(false);
1730     }
1731     ciField* field = nullptr;
1732     if (flat->isa_aryptr()) {
1733 #ifdef ASSERT
1734       const int header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1735       // (T_BYTE has the weakest alignment and size restrictions...)
1736       assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
1737 #endif
1738       const Type* elemtype = flat->is_aryptr()->elem();
1739       if (flat->offset() == TypePtr::OffsetBot) {
1740         alias_type(idx)->set_element(elemtype);
1741       }
1742       int field_offset = flat->is_aryptr()->field_offset().get();
1743       if (flat->is_flat() &&
1744           field_offset != Type::OffsetBot) {
1745         ciInlineKlass* vk = elemtype->inline_klass();
1746         field_offset += vk->first_field_offset();
1747         field = vk->get_field_by_offset(field_offset, false);
1748       }
1749     }
1750     if (flat->isa_klassptr()) {
1751       if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
1752         alias_type(idx)->set_rewritable(false);
1753       if (flat->offset() == in_bytes(Klass::modifier_flags_offset()))
1754         alias_type(idx)->set_rewritable(false);
1755       if (flat->offset() == in_bytes(Klass::access_flags_offset()))
1756         alias_type(idx)->set_rewritable(false);
1757       if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
1758         alias_type(idx)->set_rewritable(false);
1759       if (flat->offset() == in_bytes(Klass::layout_helper_offset()))
1760         alias_type(idx)->set_rewritable(false);
1761       if (flat->offset() == in_bytes(Klass::secondary_super_cache_offset()))
1762         alias_type(idx)->set_rewritable(false);
1763     }
1764     // %%% (We would like to finalize JavaThread::threadObj_offset(),
1765     // but the base pointer type is not distinctive enough to identify
1766     // references into JavaThread.)
1767 
1768     // Check for final fields.
1769     const TypeInstPtr* tinst = flat->isa_instptr();
1770     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
1771       if (tinst->const_oop() != nullptr &&
1772           tinst->instance_klass() == ciEnv::current()->Class_klass() &&
1773           tinst->offset() >= (tinst->instance_klass()->layout_helper_size_in_bytes())) {
1774         // static field
1775         ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
1776         field = k->get_field_by_offset(tinst->offset(), true);
1777       } else if (tinst->is_inlinetypeptr()) {
1778         // Inline type field
1779         ciInlineKlass* vk = tinst->inline_klass();
1780         field = vk->get_field_by_offset(tinst->offset(), false);
1781       } else {
1782         ciInstanceKlass *k = tinst->instance_klass();
1783         field = k->get_field_by_offset(tinst->offset(), false);
1784       }
1785     }
1786     assert(field == nullptr ||
1787            original_field == nullptr ||
1788            (field->holder() == original_field->holder() &&
1789             field->offset_in_bytes() == original_field->offset_in_bytes() &&
1790             field->is_static() == original_field->is_static()), "wrong field?");
1791     // Set field() and is_rewritable() attributes.
1792     if (field != nullptr) {
1793       alias_type(idx)->set_field(field);
1794       if (flat->isa_aryptr()) {
1795         // Fields of flat arrays are rewritable although they are declared final
1796         assert(flat->is_flat(), "must be a flat array");
1797         alias_type(idx)->set_rewritable(true);
1798       }
1799     }
1800   }
1801 
1802   // Fill the cache for next time.
1803   if (!uncached) {
1804     ace->_adr_type = adr_type;
1805     ace->_index    = idx;
1806     assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
1807 
1808     // Might as well try to fill the cache for the flattened version, too.
1809     AliasCacheEntry* face = probe_alias_cache(flat);
1810     if (face->_adr_type == nullptr) {
1811       face->_adr_type = flat;
1812       face->_index    = idx;
1813       assert(alias_type(flat) == alias_type(idx), "flat type must work too");
1814     }
1815   }
1816 
1817   return alias_type(idx);
1818 }
1819 
1820 
1821 Compile::AliasType* Compile::alias_type(ciField* field) {
1822   const TypeOopPtr* t;
1823   if (field->is_static())
1824     t = TypeInstPtr::make(field->holder()->java_mirror());
1825   else
1826     t = TypeOopPtr::make_from_klass_raw(field->holder());
1827   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);
1828   assert((field->is_final() || field->is_stable()) == !atp->is_rewritable(), "must get the rewritable bits correct");
1829   return atp;
1830 }
1831 
1832 
1833 //------------------------------have_alias_type--------------------------------
1834 bool Compile::have_alias_type(const TypePtr* adr_type) {
1835   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1836   if (ace->_adr_type == adr_type) {
1837     return true;
1838   }
1839 
1840   // Handle special cases.
1841   if (adr_type == nullptr)             return true;
1842   if (adr_type == TypePtr::BOTTOM)  return true;
1843 
1844   return find_alias_type(adr_type, true, nullptr) != nullptr;
1845 }
1846 
1847 //-----------------------------must_alias--------------------------------------
1848 // True if all values of the given address type are in the given alias category.
1849 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
1850   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1851   if (adr_type == nullptr)              return true;  // null serves as TypePtr::TOP
1852   if (alias_idx == AliasIdxTop)         return false; // the empty category
1853   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
1854 
1855   // the only remaining possible overlap is identity
1856   int adr_idx = get_alias_index(adr_type);
1857   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1858   assert(adr_idx == alias_idx ||
1859          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
1860           && adr_type                       != TypeOopPtr::BOTTOM),
1861          "should not be testing for overlap with an unsafe pointer");
1862   return adr_idx == alias_idx;
1863 }
1864 
1865 //------------------------------can_alias--------------------------------------
1866 // True if any values of the given address type are in the given alias category.
1867 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
1868   if (alias_idx == AliasIdxTop)         return false; // the empty category
1869   if (adr_type == nullptr)              return false; // null serves as TypePtr::TOP
1870   // Known instance doesn't alias with bottom memory
1871   if (alias_idx == AliasIdxBot)         return !adr_type->is_known_instance();                   // the universal category
1872   if (adr_type->base() == Type::AnyPtr) return !C->get_adr_type(alias_idx)->is_known_instance(); // TypePtr::BOTTOM or its twins
1873 
1874   // the only remaining possible overlap is identity
1875   int adr_idx = get_alias_index(adr_type);
1876   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1877   return adr_idx == alias_idx;
1878 }
1879 
1880 // Remove the opaque nodes that protect the Parse Predicates so that all unused
1881 // checks and uncommon_traps will be eliminated from the ideal graph.
1882 void Compile::cleanup_parse_predicates(PhaseIterGVN& igvn) const {
1883   if (parse_predicate_count() == 0) {
1884     return;
1885   }
1886   for (int i = parse_predicate_count(); i > 0; i--) {
1887     Node* n = parse_predicate_opaque1_node(i - 1);
1888     assert(n->Opcode() == Op_Opaque1, "must be");
1889     igvn.replace_node(n, n->in(1));
1890   }
1891   assert(parse_predicate_count() == 0, "should be clean!");
1892 }
1893 
1894 void Compile::record_for_post_loop_opts_igvn(Node* n) {
1895   if (!n->for_post_loop_opts_igvn()) {
1896     assert(!_for_post_loop_igvn.contains(n), "duplicate");
1897     n->add_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
1898     _for_post_loop_igvn.append(n);
1899   }
1900 }
1901 
1902 void Compile::remove_from_post_loop_opts_igvn(Node* n) {
1903   n->remove_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
1904   _for_post_loop_igvn.remove(n);
1905 }
1906 
1907 void Compile::process_for_post_loop_opts_igvn(PhaseIterGVN& igvn) {
1908   // Verify that all previous optimizations produced a valid graph
1909   // at least to this point, even if no loop optimizations were done.
1910   PhaseIdealLoop::verify(igvn);
1911 
1912   C->set_post_loop_opts_phase(); // no more loop opts allowed
1913 
1914   assert(!C->major_progress(), "not cleared");
1915 
1916   if (_for_post_loop_igvn.length() > 0) {
1917     while (_for_post_loop_igvn.length() > 0) {
1918       Node* n = _for_post_loop_igvn.pop();
1919       n->remove_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
1920       igvn._worklist.push(n);
1921     }
1922     igvn.optimize();
1923     assert(_for_post_loop_igvn.length() == 0, "no more delayed nodes allowed");
1924 
1925     // Sometimes IGVN sets major progress (e.g., when processing loop nodes).
1926     if (C->major_progress()) {
1927       C->clear_major_progress(); // ensure that major progress is now clear
1928     }
1929   }
1930 }
1931 
1932 void Compile::add_inline_type(Node* n) {
1933   assert(n->is_InlineType(), "unexpected node");
1934   _inline_type_nodes.push(n);
1935 }
1936 
1937 void Compile::remove_inline_type(Node* n) {
1938   assert(n->is_InlineType(), "unexpected node");
1939   if (_inline_type_nodes.contains(n)) {
1940     _inline_type_nodes.remove(n);
1941   }
1942 }
1943 
1944 // Does the return value keep otherwise useless inline type allocations alive?
1945 static bool return_val_keeps_allocations_alive(Node* ret_val) {
1946   ResourceMark rm;
1947   Unique_Node_List wq;
1948   wq.push(ret_val);
1949   bool some_allocations = false;
1950   for (uint i = 0; i < wq.size(); i++) {
1951     Node* n = wq.at(i);
1952     if (n->outcnt() > 1) {
1953       // Some other use for the allocation
1954       return false;
1955     } else if (n->is_InlineType()) {
1956       wq.push(n->in(1));
1957     } else if (n->is_Phi()) {
1958       for (uint j = 1; j < n->req(); j++) {
1959         wq.push(n->in(j));
1960       }
1961     } else if (n->is_CheckCastPP() &&
1962                n->in(1)->is_Proj() &&
1963                n->in(1)->in(0)->is_Allocate()) {
1964       some_allocations = true;
1965     } else if (n->is_CheckCastPP()) {
1966       wq.push(n->in(1));
1967     }
1968   }
1969   return some_allocations;
1970 }
1971 
1972 void Compile::process_inline_types(PhaseIterGVN &igvn, bool remove) {
1973   // Make sure that the return value does not keep an otherwise unused allocation alive
1974   if (tf()->returns_inline_type_as_fields()) {
1975     Node* ret = nullptr;
1976     for (uint i = 1; i < root()->req(); i++) {
1977       Node* in = root()->in(i);
1978       if (in->Opcode() == Op_Return) {
1979         assert(ret == nullptr, "only one return");
1980         ret = in;
1981       }
1982     }
1983     if (ret != nullptr) {
1984       Node* ret_val = ret->in(TypeFunc::Parms);
1985       if (igvn.type(ret_val)->isa_oopptr() &&
1986           return_val_keeps_allocations_alive(ret_val)) {
1987         igvn.replace_input_of(ret, TypeFunc::Parms, InlineTypeNode::tagged_klass(igvn.type(ret_val)->inline_klass(), igvn));
1988         assert(ret_val->outcnt() == 0, "should be dead now");
1989         igvn.remove_dead_node(ret_val);
1990       }
1991     }
1992   }
1993   if (_inline_type_nodes.length() == 0) {
1994     return;
1995   }
1996   // Scalarize inline types in safepoint debug info.
1997   // Delay this until all inlining is over to avoid getting inconsistent debug info.
1998   set_scalarize_in_safepoints(true);
1999   for (int i = _inline_type_nodes.length()-1; i >= 0; i--) {
2000     _inline_type_nodes.at(i)->as_InlineType()->make_scalar_in_safepoints(&igvn);
2001   }
2002   if (remove) {
2003     // Remove inline type nodes by replacing them with their oop input
2004     while (_inline_type_nodes.length() > 0) {
2005       InlineTypeNode* vt = _inline_type_nodes.pop()->as_InlineType();
2006       if (vt->outcnt() == 0) {
2007         igvn.remove_dead_node(vt);
2008         continue;
2009       }
2010       for (DUIterator i = vt->outs(); vt->has_out(i); i++) {
2011         DEBUG_ONLY(bool must_be_buffered = false);
2012         Node* u = vt->out(i);
2013         // Check if any users are blackholes. If so, rewrite them to use either the
2014         // allocated buffer, or individual components, instead of the inline type node
2015         // that goes away.
2016         if (u->is_Blackhole()) {
2017           BlackholeNode* bh = u->as_Blackhole();
2018 
2019           // Unlink the old input
2020           int idx = bh->find_edge(vt);
2021           assert(idx != -1, "The edge should be there");
2022           bh->del_req(idx);
2023           --i;
2024 
2025           if (vt->is_allocated(&igvn)) {
2026             // Already has the allocated instance, blackhole that
2027             bh->add_req(vt->get_oop());
2028           } else {
2029             // Not allocated yet, blackhole the components
2030             for (uint c = 0; c < vt->field_count(); c++) {
2031               bh->add_req(vt->field_value(c));
2032             }
2033           }
2034 
2035           // Node modified, record for IGVN
2036           igvn.record_for_igvn(bh);
2037         }
2038 #ifdef ASSERT
2039         // Verify that inline type is buffered when replacing by oop
2040         else if (u->is_InlineType()) {
2041           // InlineType uses don't need buffering because they are about to be replaced as well
2042         } else if (u->is_Phi()) {
2043           // TODO 8302217 Remove this once InlineTypeNodes are reliably pushed through
2044         } else {
2045           must_be_buffered = true;
2046         }
2047         if (must_be_buffered && !vt->is_allocated(&igvn)) {
2048           vt->dump(0);
2049           u->dump(0);
2050           assert(false, "Should have been buffered");
2051         }
2052 #endif
2053       }
2054       igvn.replace_node(vt, vt->get_oop());
2055     }
2056   }
2057   igvn.optimize();
2058 }
2059 
2060 void Compile::adjust_flat_array_access_aliases(PhaseIterGVN& igvn) {
2061   if (!_has_flat_accesses) {
2062     return;
2063   }
2064   // Initially, all flat array accesses share the same slice to
2065   // keep dependencies with Object[] array accesses (that could be
2066   // to a flat array) correct. We're done with parsing so we
2067   // now know all flat array accesses in this compile
2068   // unit. Let's move flat array accesses to their own slice,
2069   // one per element field. This should help memory access
2070   // optimizations.
2071   ResourceMark rm;
2072   Unique_Node_List wq;
2073   wq.push(root());
2074 
2075   Node_List mergememnodes;
2076   Node_List memnodes;
2077 
2078   // Alias index currently shared by all flat memory accesses
2079   int index = get_alias_index(TypeAryPtr::INLINES);
2080 
2081   // Find MergeMem nodes and flat array accesses
2082   for (uint i = 0; i < wq.size(); i++) {
2083     Node* n = wq.at(i);
2084     if (n->is_Mem()) {
2085       const TypePtr* adr_type = nullptr;
2086       if (n->Opcode() == Op_StoreCM) {
2087         adr_type = get_adr_type(get_alias_index(n->in(MemNode::OopStore)->adr_type()));
2088       } else {
2089         adr_type = get_adr_type(get_alias_index(n->adr_type()));
2090       }
2091       if (adr_type == TypeAryPtr::INLINES) {
2092         memnodes.push(n);
2093       }
2094     } else if (n->is_MergeMem()) {
2095       MergeMemNode* mm = n->as_MergeMem();
2096       if (mm->memory_at(index) != mm->base_memory()) {
2097         mergememnodes.push(n);
2098       }
2099     }
2100     for (uint j = 0; j < n->req(); j++) {
2101       Node* m = n->in(j);
2102       if (m != nullptr) {
2103         wq.push(m);
2104       }
2105     }
2106   }
2107 
2108   if (memnodes.size() > 0) {
2109     _flat_accesses_share_alias = false;
2110 
2111     // We are going to change the slice for the flat array
2112     // accesses so we need to clear the cache entries that refer to
2113     // them.
2114     for (uint i = 0; i < AliasCacheSize; i++) {
2115       AliasCacheEntry* ace = &_alias_cache[i];
2116       if (ace->_adr_type != nullptr &&
2117           ace->_adr_type->is_flat()) {
2118         ace->_adr_type = nullptr;
2119         ace->_index = (i != 0) ? 0 : AliasIdxTop; // Make sure the nullptr adr_type resolves to AliasIdxTop
2120       }
2121     }
2122 
2123     // Find what aliases we are going to add
2124     int start_alias = num_alias_types()-1;
2125     int stop_alias = 0;
2126 
2127     for (uint i = 0; i < memnodes.size(); i++) {
2128       Node* m = memnodes.at(i);
2129       const TypePtr* adr_type = nullptr;
2130       if (m->Opcode() == Op_StoreCM) {
2131         adr_type = m->in(MemNode::OopStore)->adr_type();
2132         if (adr_type != TypeAryPtr::INLINES) {
2133           // store was optimized out and we lost track of the adr_type
2134           Node* clone = new StoreCMNode(m->in(MemNode::Control), m->in(MemNode::Memory), m->in(MemNode::Address),
2135                                         m->adr_type(), m->in(MemNode::ValueIn), m->in(MemNode::OopStore),
2136                                         get_alias_index(adr_type));
2137           igvn.register_new_node_with_optimizer(clone);
2138           igvn.replace_node(m, clone);
2139         }
2140       } else {
2141         adr_type = m->adr_type();
2142 #ifdef ASSERT
2143         m->as_Mem()->set_adr_type(adr_type);
2144 #endif
2145       }
2146       int idx = get_alias_index(adr_type);
2147       start_alias = MIN2(start_alias, idx);
2148       stop_alias = MAX2(stop_alias, idx);
2149     }
2150 
2151     assert(stop_alias >= start_alias, "should have expanded aliases");
2152 
2153     Node_Stack stack(0);
2154 #ifdef ASSERT
2155     VectorSet seen(Thread::current()->resource_area());
2156 #endif
2157     // Now let's fix the memory graph so each flat array access
2158     // is moved to the right slice. Start from the MergeMem nodes.
2159     uint last = unique();
2160     for (uint i = 0; i < mergememnodes.size(); i++) {
2161       MergeMemNode* current = mergememnodes.at(i)->as_MergeMem();
2162       Node* n = current->memory_at(index);
2163       MergeMemNode* mm = nullptr;
2164       do {
2165         // Follow memory edges through memory accesses, phis and
2166         // narrow membars and push nodes on the stack. Once we hit
2167         // bottom memory, we pop element off the stack one at a
2168         // time, in reverse order, and move them to the right slice
2169         // by changing their memory edges.
2170         if ((n->is_Phi() && n->adr_type() != TypePtr::BOTTOM) || n->is_Mem() || n->adr_type() == TypeAryPtr::INLINES) {
2171           assert(!seen.test_set(n->_idx), "");
2172           // Uses (a load for instance) will need to be moved to the
2173           // right slice as well and will get a new memory state
2174           // that we don't know yet. The use could also be the
2175           // backedge of a loop. We put a place holder node between
2176           // the memory node and its uses. We replace that place
2177           // holder with the correct memory state once we know it,
2178           // i.e. when nodes are popped off the stack. Using the
2179           // place holder make the logic work in the presence of
2180           // loops.
2181           if (n->outcnt() > 1) {
2182             Node* place_holder = nullptr;
2183             assert(!n->has_out_with(Op_Node), "");
2184             for (DUIterator k = n->outs(); n->has_out(k); k++) {
2185               Node* u = n->out(k);
2186               if (u != current && u->_idx < last) {
2187                 bool success = false;
2188                 for (uint l = 0; l < u->req(); l++) {
2189                   if (!stack.is_empty() && u == stack.node() && l == stack.index()) {
2190                     continue;
2191                   }
2192                   Node* in = u->in(l);
2193                   if (in == n) {
2194                     if (place_holder == nullptr) {
2195                       place_holder = new Node(1);
2196                       place_holder->init_req(0, n);
2197                     }
2198                     igvn.replace_input_of(u, l, place_holder);
2199                     success = true;
2200                   }
2201                 }
2202                 if (success) {
2203                   --k;
2204                 }
2205               }
2206             }
2207           }
2208           if (n->is_Phi()) {
2209             stack.push(n, 1);
2210             n = n->in(1);
2211           } else if (n->is_Mem()) {
2212             stack.push(n, n->req());
2213             n = n->in(MemNode::Memory);
2214           } else {
2215             assert(n->is_Proj() && n->in(0)->Opcode() == Op_MemBarCPUOrder, "");
2216             stack.push(n, n->req());
2217             n = n->in(0)->in(TypeFunc::Memory);
2218           }
2219         } else {
2220           assert(n->adr_type() == TypePtr::BOTTOM || (n->Opcode() == Op_Node && n->_idx >= last) || (n->is_Proj() && n->in(0)->is_Initialize()), "");
2221           // Build a new MergeMem node to carry the new memory state
2222           // as we build it. IGVN should fold extraneous MergeMem
2223           // nodes.
2224           mm = MergeMemNode::make(n);
2225           igvn.register_new_node_with_optimizer(mm);
2226           while (stack.size() > 0) {
2227             Node* m = stack.node();
2228             uint idx = stack.index();
2229             if (m->is_Mem()) {
2230               // Move memory node to its new slice
2231               const TypePtr* adr_type = m->adr_type();
2232               int alias = get_alias_index(adr_type);
2233               Node* prev = mm->memory_at(alias);
2234               igvn.replace_input_of(m, MemNode::Memory, prev);
2235               mm->set_memory_at(alias, m);
2236             } else if (m->is_Phi()) {
2237               // We need as many new phis as there are new aliases
2238               igvn.replace_input_of(m, idx, mm);
2239               if (idx == m->req()-1) {
2240                 Node* r = m->in(0);
2241                 for (uint j = (uint)start_alias; j <= (uint)stop_alias; j++) {
2242                   const TypePtr* adr_type = get_adr_type(j);
2243                   if (!adr_type->isa_aryptr() || !adr_type->is_flat() || j == (uint)index) {
2244                     continue;
2245                   }
2246                   Node* phi = new PhiNode(r, Type::MEMORY, get_adr_type(j));
2247                   igvn.register_new_node_with_optimizer(phi);
2248                   for (uint k = 1; k < m->req(); k++) {
2249                     phi->init_req(k, m->in(k)->as_MergeMem()->memory_at(j));
2250                   }
2251                   mm->set_memory_at(j, phi);
2252                 }
2253                 Node* base_phi = new PhiNode(r, Type::MEMORY, TypePtr::BOTTOM);
2254                 igvn.register_new_node_with_optimizer(base_phi);
2255                 for (uint k = 1; k < m->req(); k++) {
2256                   base_phi->init_req(k, m->in(k)->as_MergeMem()->base_memory());
2257                 }
2258                 mm->set_base_memory(base_phi);
2259               }
2260             } else {
2261               // This is a MemBarCPUOrder node from
2262               // Parse::array_load()/Parse::array_store(), in the
2263               // branch that handles flat arrays hidden under
2264               // an Object[] array. We also need one new membar per
2265               // new alias to keep the unknown access that the
2266               // membars protect properly ordered with accesses to
2267               // known flat array.
2268               assert(m->is_Proj(), "projection expected");
2269               Node* ctrl = m->in(0)->in(TypeFunc::Control);
2270               igvn.replace_input_of(m->in(0), TypeFunc::Control, top());
2271               for (uint j = (uint)start_alias; j <= (uint)stop_alias; j++) {
2272                 const TypePtr* adr_type = get_adr_type(j);
2273                 if (!adr_type->isa_aryptr() || !adr_type->is_flat() || j == (uint)index) {
2274                   continue;
2275                 }
2276                 MemBarNode* mb = new MemBarCPUOrderNode(this, j, nullptr);
2277                 igvn.register_new_node_with_optimizer(mb);
2278                 Node* mem = mm->memory_at(j);
2279                 mb->init_req(TypeFunc::Control, ctrl);
2280                 mb->init_req(TypeFunc::Memory, mem);
2281                 ctrl = new ProjNode(mb, TypeFunc::Control);
2282                 igvn.register_new_node_with_optimizer(ctrl);
2283                 mem = new ProjNode(mb, TypeFunc::Memory);
2284                 igvn.register_new_node_with_optimizer(mem);
2285                 mm->set_memory_at(j, mem);
2286               }
2287               igvn.replace_node(m->in(0)->as_Multi()->proj_out(TypeFunc::Control), ctrl);
2288             }
2289             if (idx < m->req()-1) {
2290               idx += 1;
2291               stack.set_index(idx);
2292               n = m->in(idx);
2293               break;
2294             }
2295             // Take care of place holder nodes
2296             if (m->has_out_with(Op_Node)) {
2297               Node* place_holder = m->find_out_with(Op_Node);
2298               if (place_holder != nullptr) {
2299                 Node* mm_clone = mm->clone();
2300                 igvn.register_new_node_with_optimizer(mm_clone);
2301                 Node* hook = new Node(1);
2302                 hook->init_req(0, mm);
2303                 igvn.replace_node(place_holder, mm_clone);
2304                 hook->destruct(&igvn);
2305               }
2306               assert(!m->has_out_with(Op_Node), "place holder should be gone now");
2307             }
2308             stack.pop();
2309           }
2310         }
2311       } while(stack.size() > 0);
2312       // Fix the memory state at the MergeMem we started from
2313       igvn.rehash_node_delayed(current);
2314       for (uint j = (uint)start_alias; j <= (uint)stop_alias; j++) {
2315         const TypePtr* adr_type = get_adr_type(j);
2316         if (!adr_type->isa_aryptr() || !adr_type->is_flat()) {
2317           continue;
2318         }
2319         current->set_memory_at(j, mm);
2320       }
2321       current->set_memory_at(index, current->base_memory());
2322     }
2323     igvn.optimize();
2324   }
2325   print_method(PHASE_SPLIT_INLINES_ARRAY, 2);
2326 #ifdef ASSERT
2327   if (!_flat_accesses_share_alias) {
2328     wq.clear();
2329     wq.push(root());
2330     for (uint i = 0; i < wq.size(); i++) {
2331       Node* n = wq.at(i);
2332       assert(n->adr_type() != TypeAryPtr::INLINES, "should have been removed from the graph");
2333       for (uint j = 0; j < n->req(); j++) {
2334         Node* m = n->in(j);
2335         if (m != nullptr) {
2336           wq.push(m);
2337         }
2338       }
2339     }
2340   }
2341 #endif
2342 }
2343 
2344 void Compile::record_unstable_if_trap(UnstableIfTrap* trap) {
2345   if (OptimizeUnstableIf) {
2346     _unstable_if_traps.append(trap);
2347   }
2348 }
2349 
2350 void Compile::remove_useless_unstable_if_traps(Unique_Node_List& useful) {
2351   for (int i = _unstable_if_traps.length() - 1; i >= 0; i--) {
2352     UnstableIfTrap* trap = _unstable_if_traps.at(i);
2353     Node* n = trap->uncommon_trap();
2354     if (!useful.member(n)) {
2355       _unstable_if_traps.delete_at(i); // replaces i-th with last element which is known to be useful (already processed)
2356     }
2357   }
2358 }
2359 
2360 // Remove the unstable if trap associated with 'unc' from candidates. It is either dead
2361 // or fold-compares case. Return true if succeed or not found.
2362 //
2363 // In rare cases, the found trap has been processed. It is too late to delete it. Return
2364 // false and ask fold-compares to yield.
2365 //
2366 // 'fold-compares' may use the uncommon_trap of the dominating IfNode to cover the fused
2367 // IfNode. This breaks the unstable_if trap invariant: control takes the unstable path
2368 // when deoptimization does happen.
2369 bool Compile::remove_unstable_if_trap(CallStaticJavaNode* unc, bool yield) {
2370   for (int i = 0; i < _unstable_if_traps.length(); ++i) {
2371     UnstableIfTrap* trap = _unstable_if_traps.at(i);
2372     if (trap->uncommon_trap() == unc) {
2373       if (yield && trap->modified()) {
2374         return false;
2375       }
2376       _unstable_if_traps.delete_at(i);
2377       break;
2378     }
2379   }
2380   return true;
2381 }
2382 
2383 // Re-calculate unstable_if traps with the liveness of next_bci, which points to the unlikely path.
2384 // It needs to be done after igvn because fold-compares may fuse uncommon_traps and before renumbering.
2385 void Compile::process_for_unstable_if_traps(PhaseIterGVN& igvn) {
2386   for (int i = _unstable_if_traps.length() - 1; i >= 0; --i) {
2387     UnstableIfTrap* trap = _unstable_if_traps.at(i);
2388     CallStaticJavaNode* unc = trap->uncommon_trap();
2389     int next_bci = trap->next_bci();
2390     bool modified = trap->modified();
2391 
2392     if (next_bci != -1 && !modified) {
2393       assert(!_dead_node_list.test(unc->_idx), "changing a dead node!");
2394       JVMState* jvms = unc->jvms();
2395       ciMethod* method = jvms->method();
2396       ciBytecodeStream iter(method);
2397 
2398       iter.force_bci(jvms->bci());
2399       assert(next_bci == iter.next_bci() || next_bci == iter.get_dest(), "wrong next_bci at unstable_if");
2400       Bytecodes::Code c = iter.cur_bc();
2401       Node* lhs = nullptr;
2402       Node* rhs = nullptr;
2403       if (c == Bytecodes::_if_acmpeq || c == Bytecodes::_if_acmpne) {
2404         lhs = unc->peek_operand(0);
2405         rhs = unc->peek_operand(1);
2406       } else if (c == Bytecodes::_ifnull || c == Bytecodes::_ifnonnull) {
2407         lhs = unc->peek_operand(0);
2408       }
2409 
2410       ResourceMark rm;
2411       const MethodLivenessResult& live_locals = method->liveness_at_bci(next_bci);
2412       assert(live_locals.is_valid(), "broken liveness info");
2413       int len = (int)live_locals.size();
2414 
2415       for (int i = 0; i < len; i++) {
2416         Node* local = unc->local(jvms, i);
2417         // kill local using the liveness of next_bci.
2418         // give up when the local looks like an operand to secure reexecution.
2419         if (!live_locals.at(i) && !local->is_top() && local != lhs && local!= rhs) {
2420           uint idx = jvms->locoff() + i;
2421 #ifdef ASSERT
2422           if (PrintOpto && Verbose) {
2423             tty->print("[unstable_if] kill local#%d: ", idx);
2424             local->dump();
2425             tty->cr();
2426           }
2427 #endif
2428           igvn.replace_input_of(unc, idx, top());
2429           modified = true;
2430         }
2431       }
2432     }
2433 
2434     // keep the mondified trap for late query
2435     if (modified) {
2436       trap->set_modified();
2437     } else {
2438       _unstable_if_traps.delete_at(i);
2439     }
2440   }
2441   igvn.optimize();
2442 }
2443 
2444 // StringOpts and late inlining of string methods
2445 void Compile::inline_string_calls(bool parse_time) {
2446   {
2447     // remove useless nodes to make the usage analysis simpler
2448     ResourceMark rm;
2449     PhaseRemoveUseless pru(initial_gvn(), *igvn_worklist());
2450   }
2451 
2452   {
2453     ResourceMark rm;
2454     print_method(PHASE_BEFORE_STRINGOPTS, 3);
2455     PhaseStringOpts pso(initial_gvn());
2456     print_method(PHASE_AFTER_STRINGOPTS, 3);
2457   }
2458 
2459   // now inline anything that we skipped the first time around
2460   if (!parse_time) {
2461     _late_inlines_pos = _late_inlines.length();
2462   }
2463 
2464   while (_string_late_inlines.length() > 0) {
2465     CallGenerator* cg = _string_late_inlines.pop();
2466     cg->do_late_inline();
2467     if (failing())  return;
2468   }
2469   _string_late_inlines.trunc_to(0);
2470 }
2471 
2472 // Late inlining of boxing methods
2473 void Compile::inline_boxing_calls(PhaseIterGVN& igvn) {
2474   if (_boxing_late_inlines.length() > 0) {
2475     assert(has_boxed_value(), "inconsistent");
2476 
2477     PhaseGVN* gvn = initial_gvn();
2478     set_inlining_incrementally(true);
2479 
2480     igvn_worklist()->ensure_empty(); // should be done with igvn
2481 
2482     _late_inlines_pos = _late_inlines.length();
2483 
2484     while (_boxing_late_inlines.length() > 0) {
2485       CallGenerator* cg = _boxing_late_inlines.pop();
2486       cg->do_late_inline();
2487       if (failing())  return;
2488     }
2489     _boxing_late_inlines.trunc_to(0);
2490 
2491     inline_incrementally_cleanup(igvn);
2492 
2493     set_inlining_incrementally(false);
2494   }
2495 }
2496 
2497 bool Compile::inline_incrementally_one() {
2498   assert(IncrementalInline, "incremental inlining should be on");
2499 
2500   TracePhase tp("incrementalInline_inline", &timers[_t_incrInline_inline]);
2501 
2502   set_inlining_progress(false);
2503   set_do_cleanup(false);
2504 
2505   for (int i = 0; i < _late_inlines.length(); i++) {
2506     _late_inlines_pos = i+1;
2507     CallGenerator* cg = _late_inlines.at(i);
2508     bool does_dispatch = cg->is_virtual_late_inline() || cg->is_mh_late_inline();
2509     if (inlining_incrementally() || does_dispatch) { // a call can be either inlined or strength-reduced to a direct call
2510       cg->do_late_inline();
2511       assert(_late_inlines.at(i) == cg, "no insertions before current position allowed");
2512       if (failing()) {
2513         return false;
2514       } else if (inlining_progress()) {
2515         _late_inlines_pos = i+1; // restore the position in case new elements were inserted
2516         print_method(PHASE_INCREMENTAL_INLINE_STEP, 3, cg->call_node());
2517         break; // process one call site at a time
2518       }
2519     } else {
2520       // Ignore late inline direct calls when inlining is not allowed.
2521       // They are left in the late inline list when node budget is exhausted until the list is fully drained.
2522     }
2523   }
2524   // Remove processed elements.
2525   _late_inlines.remove_till(_late_inlines_pos);
2526   _late_inlines_pos = 0;
2527 
2528   assert(inlining_progress() || _late_inlines.length() == 0, "no progress");
2529 
2530   bool needs_cleanup = do_cleanup() || over_inlining_cutoff();
2531 
2532   set_inlining_progress(false);
2533   set_do_cleanup(false);
2534 
2535   bool force_cleanup = directive()->IncrementalInlineForceCleanupOption;
2536   return (_late_inlines.length() > 0) && !needs_cleanup && !force_cleanup;
2537 }
2538 
2539 void Compile::inline_incrementally_cleanup(PhaseIterGVN& igvn) {
2540   {
2541     TracePhase tp("incrementalInline_pru", &timers[_t_incrInline_pru]);
2542     ResourceMark rm;
2543     PhaseRemoveUseless pru(initial_gvn(), *igvn_worklist());
2544   }
2545   {
2546     TracePhase tp("incrementalInline_igvn", &timers[_t_incrInline_igvn]);
2547     igvn.reset_from_gvn(initial_gvn());
2548     igvn.optimize();
2549   }
2550   print_method(PHASE_INCREMENTAL_INLINE_CLEANUP, 3);
2551 }
2552 
2553 // Perform incremental inlining until bound on number of live nodes is reached
2554 void Compile::inline_incrementally(PhaseIterGVN& igvn) {
2555   TracePhase tp("incrementalInline", &timers[_t_incrInline]);
2556 
2557   set_inlining_incrementally(true);
2558   uint low_live_nodes = 0;
2559 
2560   while (_late_inlines.length() > 0) {
2561     if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2562       if (low_live_nodes < (uint)LiveNodeCountInliningCutoff * 8 / 10) {
2563         TracePhase tp("incrementalInline_ideal", &timers[_t_incrInline_ideal]);
2564         // PhaseIdealLoop is expensive so we only try it once we are
2565         // out of live nodes and we only try it again if the previous
2566         // helped got the number of nodes down significantly
2567         PhaseIdealLoop::optimize(igvn, LoopOptsNone);
2568         if (failing())  return;
2569         low_live_nodes = live_nodes();
2570         _major_progress = true;
2571       }
2572 
2573       if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2574         bool do_print_inlining = print_inlining() || print_intrinsics();
2575         if (do_print_inlining || log() != nullptr) {
2576           // Print inlining message for candidates that we couldn't inline for lack of space.
2577           for (int i = 0; i < _late_inlines.length(); i++) {
2578             CallGenerator* cg = _late_inlines.at(i);
2579             const char* msg = "live nodes > LiveNodeCountInliningCutoff";
2580             if (do_print_inlining) {
2581               cg->print_inlining_late(msg);
2582             }
2583             log_late_inline_failure(cg, msg);
2584           }
2585         }
2586         break; // finish
2587       }
2588     }
2589 
2590     igvn_worklist()->ensure_empty(); // should be done with igvn
2591 
2592     while (inline_incrementally_one()) {
2593       assert(!failing(), "inconsistent");
2594     }
2595     if (failing())  return;
2596 
2597     inline_incrementally_cleanup(igvn);
2598 
2599     print_method(PHASE_INCREMENTAL_INLINE_STEP, 3);
2600 
2601     if (failing())  return;
2602 
2603     if (_late_inlines.length() == 0) {
2604       break; // no more progress
2605     }
2606   }
2607 
2608   igvn_worklist()->ensure_empty(); // should be done with igvn
2609 
2610   if (_string_late_inlines.length() > 0) {
2611     assert(has_stringbuilder(), "inconsistent");
2612 
2613     inline_string_calls(false);
2614 
2615     if (failing())  return;
2616 
2617     inline_incrementally_cleanup(igvn);
2618   }
2619 
2620   set_inlining_incrementally(false);
2621 }
2622 
2623 void Compile::process_late_inline_calls_no_inline(PhaseIterGVN& igvn) {
2624   // "inlining_incrementally() == false" is used to signal that no inlining is allowed
2625   // (see LateInlineVirtualCallGenerator::do_late_inline_check() for details).
2626   // Tracking and verification of modified nodes is disabled by setting "_modified_nodes == nullptr"
2627   // as if "inlining_incrementally() == true" were set.
2628   assert(inlining_incrementally() == false, "not allowed");
2629 #ifdef ASSERT
2630   Unique_Node_List* modified_nodes = _modified_nodes;
2631   _modified_nodes = nullptr;
2632 #endif
2633   assert(_late_inlines.length() > 0, "sanity");
2634 
2635   while (_late_inlines.length() > 0) {
2636     igvn_worklist()->ensure_empty(); // should be done with igvn
2637 
2638     while (inline_incrementally_one()) {
2639       assert(!failing(), "inconsistent");
2640     }
2641     if (failing())  return;
2642 
2643     inline_incrementally_cleanup(igvn);
2644   }
2645   DEBUG_ONLY( _modified_nodes = modified_nodes; )
2646 }
2647 
2648 bool Compile::optimize_loops(PhaseIterGVN& igvn, LoopOptsMode mode) {
2649   if (_loop_opts_cnt > 0) {
2650     while (major_progress() && (_loop_opts_cnt > 0)) {
2651       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2652       PhaseIdealLoop::optimize(igvn, mode);
2653       _loop_opts_cnt--;
2654       if (failing())  return false;
2655       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
2656     }
2657   }
2658   return true;
2659 }
2660 
2661 // Remove edges from "root" to each SafePoint at a backward branch.
2662 // They were inserted during parsing (see add_safepoint()) to make
2663 // infinite loops without calls or exceptions visible to root, i.e.,
2664 // useful.
2665 void Compile::remove_root_to_sfpts_edges(PhaseIterGVN& igvn) {
2666   Node *r = root();
2667   if (r != nullptr) {
2668     for (uint i = r->req(); i < r->len(); ++i) {
2669       Node *n = r->in(i);
2670       if (n != nullptr && n->is_SafePoint()) {
2671         r->rm_prec(i);
2672         if (n->outcnt() == 0) {
2673           igvn.remove_dead_node(n);
2674         }
2675         --i;
2676       }
2677     }
2678     // Parsing may have added top inputs to the root node (Path
2679     // leading to the Halt node proven dead). Make sure we get a
2680     // chance to clean them up.
2681     igvn._worklist.push(r);
2682     igvn.optimize();
2683   }
2684 }
2685 
2686 //------------------------------Optimize---------------------------------------
2687 // Given a graph, optimize it.
2688 void Compile::Optimize() {
2689   TracePhase tp("optimizer", &timers[_t_optimizer]);
2690 
2691 #ifndef PRODUCT
2692   if (env()->break_at_compile()) {
2693     BREAKPOINT;
2694   }
2695 
2696 #endif
2697 
2698   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
2699 #ifdef ASSERT
2700   bs->verify_gc_barriers(this, BarrierSetC2::BeforeOptimize);
2701 #endif
2702 
2703   ResourceMark rm;
2704 
2705   print_inlining_reinit();
2706 
2707   NOT_PRODUCT( verify_graph_edges(); )
2708 
2709   print_method(PHASE_AFTER_PARSING, 1);
2710 
2711  {
2712   // Iterative Global Value Numbering, including ideal transforms
2713   // Initialize IterGVN with types and values from parse-time GVN
2714   PhaseIterGVN igvn(initial_gvn());
2715 #ifdef ASSERT
2716   _modified_nodes = new (comp_arena()) Unique_Node_List(comp_arena());
2717 #endif
2718   {
2719     TracePhase tp("iterGVN", &timers[_t_iterGVN]);
2720     igvn.optimize();
2721   }
2722 
2723   if (failing())  return;
2724 
2725   print_method(PHASE_ITER_GVN1, 2);
2726 
2727   process_for_unstable_if_traps(igvn);
2728 
2729   inline_incrementally(igvn);
2730 
2731   print_method(PHASE_INCREMENTAL_INLINE, 2);
2732 
2733   if (failing())  return;
2734 
2735   if (eliminate_boxing()) {
2736     // Inline valueOf() methods now.
2737     inline_boxing_calls(igvn);
2738 
2739     if (AlwaysIncrementalInline) {
2740       inline_incrementally(igvn);
2741     }
2742 
2743     print_method(PHASE_INCREMENTAL_BOXING_INLINE, 2);
2744 
2745     if (failing())  return;
2746   }
2747 
2748   // Remove the speculative part of types and clean up the graph from
2749   // the extra CastPP nodes whose only purpose is to carry them. Do
2750   // that early so that optimizations are not disrupted by the extra
2751   // CastPP nodes.
2752   remove_speculative_types(igvn);
2753 
2754   // No more new expensive nodes will be added to the list from here
2755   // so keep only the actual candidates for optimizations.
2756   cleanup_expensive_nodes(igvn);
2757 
2758   assert(EnableVectorSupport || !has_vbox_nodes(), "sanity");
2759   if (EnableVectorSupport && has_vbox_nodes()) {
2760     TracePhase tp("", &timers[_t_vector]);
2761     PhaseVector pv(igvn);
2762     pv.optimize_vector_boxes();
2763 
2764     print_method(PHASE_ITER_GVN_AFTER_VECTOR, 2);
2765   }
2766   assert(!has_vbox_nodes(), "sanity");
2767 
2768   if (!failing() && RenumberLiveNodes && live_nodes() + NodeLimitFudgeFactor < unique()) {
2769     Compile::TracePhase tp("", &timers[_t_renumberLive]);
2770     igvn_worklist()->ensure_empty(); // should be done with igvn
2771     {
2772       ResourceMark rm;
2773       PhaseRenumberLive prl(initial_gvn(), *igvn_worklist());
2774     }
2775     igvn.reset_from_gvn(initial_gvn());
2776     igvn.optimize();
2777   }
2778 
2779   // Now that all inlining is over and no PhaseRemoveUseless will run, cut edge from root to loop
2780   // safepoints
2781   remove_root_to_sfpts_edges(igvn);
2782 
2783   // Process inline type nodes now that all inlining is over
2784   process_inline_types(igvn);
2785 
2786   adjust_flat_array_access_aliases(igvn);
2787 
2788   // Perform escape analysis
2789   if (do_escape_analysis() && ConnectionGraph::has_candidates(this)) {
2790     if (has_loops()) {
2791       // Cleanup graph (remove dead nodes).
2792       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2793       PhaseIdealLoop::optimize(igvn, LoopOptsMaxUnroll);
2794       if (failing())  return;
2795     }
2796     bool progress;
2797     print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
2798     do {
2799       ConnectionGraph::do_analysis(this, &igvn);
2800 
2801       if (failing())  return;
2802 
2803       int mcount = macro_count(); // Record number of allocations and locks before IGVN
2804 
2805       // Optimize out fields loads from scalar replaceable allocations.
2806       igvn.optimize();
2807       print_method(PHASE_ITER_GVN_AFTER_EA, 2);
2808 
2809       if (failing())  return;
2810 
2811       if (congraph() != nullptr && macro_count() > 0) {
2812         TracePhase tp("macroEliminate", &timers[_t_macroEliminate]);
2813         PhaseMacroExpand mexp(igvn);
2814         mexp.eliminate_macro_nodes();
2815         igvn.set_delay_transform(false);
2816 
2817         igvn.optimize();
2818         print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
2819       }
2820 
2821       ConnectionGraph::verify_ram_nodes(this, root());
2822       if (failing())  return;
2823 
2824       progress = do_iterative_escape_analysis() &&
2825                  (macro_count() < mcount) &&
2826                  ConnectionGraph::has_candidates(this);
2827       // Try again if candidates exist and made progress
2828       // by removing some allocations and/or locks.
2829     } while (progress);
2830   }
2831 
2832   // Loop transforms on the ideal graph.  Range Check Elimination,
2833   // peeling, unrolling, etc.
2834 
2835   // Set loop opts counter
2836   if((_loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
2837     {
2838       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2839       PhaseIdealLoop::optimize(igvn, LoopOptsDefault);
2840       _loop_opts_cnt--;
2841       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP1, 2);
2842       if (failing())  return;
2843     }
2844     // Loop opts pass if partial peeling occurred in previous pass
2845     if(PartialPeelLoop && major_progress() && (_loop_opts_cnt > 0)) {
2846       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2847       PhaseIdealLoop::optimize(igvn, LoopOptsSkipSplitIf);
2848       _loop_opts_cnt--;
2849       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP2, 2);
2850       if (failing())  return;
2851     }
2852     // Loop opts pass for loop-unrolling before CCP
2853     if(major_progress() && (_loop_opts_cnt > 0)) {
2854       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2855       PhaseIdealLoop::optimize(igvn, LoopOptsSkipSplitIf);
2856       _loop_opts_cnt--;
2857       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP3, 2);
2858     }
2859     if (!failing()) {
2860       // Verify that last round of loop opts produced a valid graph
2861       PhaseIdealLoop::verify(igvn);
2862     }
2863   }
2864   if (failing())  return;
2865 
2866   // Conditional Constant Propagation;
2867   PhaseCCP ccp( &igvn );
2868   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
2869   {
2870     TracePhase tp("ccp", &timers[_t_ccp]);
2871     ccp.do_transform();
2872   }
2873   print_method(PHASE_CCP1, 2);
2874 
2875   assert( true, "Break here to ccp.dump_old2new_map()");
2876 
2877   // Iterative Global Value Numbering, including ideal transforms
2878   {
2879     TracePhase tp("iterGVN2", &timers[_t_iterGVN2]);
2880     igvn.reset_from_igvn(&ccp);
2881     igvn.optimize();
2882   }
2883   print_method(PHASE_ITER_GVN2, 2);
2884 
2885   if (failing())  return;
2886 
2887   // Loop transforms on the ideal graph.  Range Check Elimination,
2888   // peeling, unrolling, etc.
2889   if (!optimize_loops(igvn, LoopOptsDefault)) {
2890     return;
2891   }
2892 
2893   if (failing())  return;
2894 
2895   C->clear_major_progress(); // ensure that major progress is now clear
2896 
2897   process_for_post_loop_opts_igvn(igvn);
2898 
2899 #ifdef ASSERT
2900   bs->verify_gc_barriers(this, BarrierSetC2::BeforeMacroExpand);
2901 #endif
2902 
2903   assert(_late_inlines.length() == 0 || IncrementalInlineMH || IncrementalInlineVirtual, "not empty");
2904 
2905   if (_late_inlines.length() > 0) {
2906     // More opportunities to optimize virtual and MH calls.
2907     // Though it's maybe too late to perform inlining, strength-reducing them to direct calls is still an option.
2908     process_late_inline_calls_no_inline(igvn);
2909   }
2910 
2911   {
2912     TracePhase tp("macroExpand", &timers[_t_macroExpand]);
2913     PhaseMacroExpand  mex(igvn);
2914     if (mex.expand_macro_nodes()) {
2915       assert(failing(), "must bail out w/ explicit message");
2916       return;
2917     }
2918     print_method(PHASE_MACRO_EXPANSION, 2);
2919   }
2920 
2921   // Process inline type nodes again and remove them. From here
2922   // on we don't need to keep track of field values anymore.
2923   process_inline_types(igvn, /* remove= */ true);
2924 
2925   {
2926     TracePhase tp("barrierExpand", &timers[_t_barrierExpand]);
2927     if (bs->expand_barriers(this, igvn)) {
2928       assert(failing(), "must bail out w/ explicit message");
2929       return;
2930     }
2931     print_method(PHASE_BARRIER_EXPANSION, 2);
2932   }
2933 
2934   if (C->max_vector_size() > 0) {
2935     C->optimize_logic_cones(igvn);
2936     igvn.optimize();
2937   }
2938 
2939   DEBUG_ONLY( _modified_nodes = nullptr; )
2940   DEBUG_ONLY( _late_inlines.clear(); )
2941 
2942   assert(igvn._worklist.size() == 0, "not empty");
2943  } // (End scope of igvn; run destructor if necessary for asserts.)
2944 
2945  check_no_dead_use();
2946 
2947  process_print_inlining();
2948 
2949  // We will never use the NodeHash table any more. Clear it so that final_graph_reshaping does not have
2950  // to remove hashes to unlock nodes for modifications.
2951  C->node_hash()->clear();
2952 
2953  // A method with only infinite loops has no edges entering loops from root
2954  {
2955    TracePhase tp("graphReshape", &timers[_t_graphReshaping]);
2956    if (final_graph_reshaping()) {
2957      assert(failing(), "must bail out w/ explicit message");
2958      return;
2959    }
2960  }
2961 
2962  print_method(PHASE_OPTIMIZE_FINISHED, 2);
2963  DEBUG_ONLY(set_phase_optimize_finished();)
2964 }
2965 
2966 #ifdef ASSERT
2967 void Compile::check_no_dead_use() const {
2968   ResourceMark rm;
2969   Unique_Node_List wq;
2970   wq.push(root());
2971   for (uint i = 0; i < wq.size(); ++i) {
2972     Node* n = wq.at(i);
2973     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
2974       Node* u = n->fast_out(j);
2975       if (u->outcnt() == 0 && !u->is_Con()) {
2976         u->dump();
2977         fatal("no reachable node should have no use");
2978       }
2979       wq.push(u);
2980     }
2981   }
2982 }
2983 #endif
2984 
2985 void Compile::inline_vector_reboxing_calls() {
2986   if (C->_vector_reboxing_late_inlines.length() > 0) {
2987     _late_inlines_pos = C->_late_inlines.length();
2988     while (_vector_reboxing_late_inlines.length() > 0) {
2989       CallGenerator* cg = _vector_reboxing_late_inlines.pop();
2990       cg->do_late_inline();
2991       if (failing())  return;
2992       print_method(PHASE_INLINE_VECTOR_REBOX, 3, cg->call_node());
2993     }
2994     _vector_reboxing_late_inlines.trunc_to(0);
2995   }
2996 }
2997 
2998 bool Compile::has_vbox_nodes() {
2999   if (C->_vector_reboxing_late_inlines.length() > 0) {
3000     return true;
3001   }
3002   for (int macro_idx = C->macro_count() - 1; macro_idx >= 0; macro_idx--) {
3003     Node * n = C->macro_node(macro_idx);
3004     assert(n->is_macro(), "only macro nodes expected here");
3005     if (n->Opcode() == Op_VectorUnbox || n->Opcode() == Op_VectorBox || n->Opcode() == Op_VectorBoxAllocate) {
3006       return true;
3007     }
3008   }
3009   return false;
3010 }
3011 
3012 //---------------------------- Bitwise operation packing optimization ---------------------------
3013 
3014 static bool is_vector_unary_bitwise_op(Node* n) {
3015   return n->Opcode() == Op_XorV &&
3016          VectorNode::is_vector_bitwise_not_pattern(n);
3017 }
3018 
3019 static bool is_vector_binary_bitwise_op(Node* n) {
3020   switch (n->Opcode()) {
3021     case Op_AndV:
3022     case Op_OrV:
3023       return true;
3024 
3025     case Op_XorV:
3026       return !is_vector_unary_bitwise_op(n);
3027 
3028     default:
3029       return false;
3030   }
3031 }
3032 
3033 static bool is_vector_ternary_bitwise_op(Node* n) {
3034   return n->Opcode() == Op_MacroLogicV;
3035 }
3036 
3037 static bool is_vector_bitwise_op(Node* n) {
3038   return is_vector_unary_bitwise_op(n)  ||
3039          is_vector_binary_bitwise_op(n) ||
3040          is_vector_ternary_bitwise_op(n);
3041 }
3042 
3043 static bool is_vector_bitwise_cone_root(Node* n) {
3044   if (n->bottom_type()->isa_vectmask() || !is_vector_bitwise_op(n)) {
3045     return false;
3046   }
3047   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3048     if (is_vector_bitwise_op(n->fast_out(i))) {
3049       return false;
3050     }
3051   }
3052   return true;
3053 }
3054 
3055 static uint collect_unique_inputs(Node* n, Unique_Node_List& inputs) {
3056   uint cnt = 0;
3057   if (is_vector_bitwise_op(n)) {
3058     uint inp_cnt = n->is_predicated_vector() ? n->req()-1 : n->req();
3059     if (VectorNode::is_vector_bitwise_not_pattern(n)) {
3060       for (uint i = 1; i < inp_cnt; i++) {
3061         Node* in = n->in(i);
3062         bool skip = VectorNode::is_all_ones_vector(in);
3063         if (!skip && !inputs.member(in)) {
3064           inputs.push(in);
3065           cnt++;
3066         }
3067       }
3068       assert(cnt <= 1, "not unary");
3069     } else {
3070       uint last_req = inp_cnt;
3071       if (is_vector_ternary_bitwise_op(n)) {
3072         last_req = inp_cnt - 1; // skip last input
3073       }
3074       for (uint i = 1; i < last_req; i++) {
3075         Node* def = n->in(i);
3076         if (!inputs.member(def)) {
3077           inputs.push(def);
3078           cnt++;
3079         }
3080       }
3081     }
3082   } else { // not a bitwise operations
3083     if (!inputs.member(n)) {
3084       inputs.push(n);
3085       cnt++;
3086     }
3087   }
3088   return cnt;
3089 }
3090 
3091 void Compile::collect_logic_cone_roots(Unique_Node_List& list) {
3092   Unique_Node_List useful_nodes;
3093   C->identify_useful_nodes(useful_nodes);
3094 
3095   for (uint i = 0; i < useful_nodes.size(); i++) {
3096     Node* n = useful_nodes.at(i);
3097     if (is_vector_bitwise_cone_root(n)) {
3098       list.push(n);
3099     }
3100   }
3101 }
3102 
3103 Node* Compile::xform_to_MacroLogicV(PhaseIterGVN& igvn,
3104                                     const TypeVect* vt,
3105                                     Unique_Node_List& partition,
3106                                     Unique_Node_List& inputs) {
3107   assert(partition.size() == 2 || partition.size() == 3, "not supported");
3108   assert(inputs.size()    == 2 || inputs.size()    == 3, "not supported");
3109   assert(Matcher::match_rule_supported_vector(Op_MacroLogicV, vt->length(), vt->element_basic_type()), "not supported");
3110 
3111   Node* in1 = inputs.at(0);
3112   Node* in2 = inputs.at(1);
3113   Node* in3 = (inputs.size() == 3 ? inputs.at(2) : in2);
3114 
3115   uint func = compute_truth_table(partition, inputs);
3116 
3117   Node* pn = partition.at(partition.size() - 1);
3118   Node* mask = pn->is_predicated_vector() ? pn->in(pn->req()-1) : nullptr;
3119   return igvn.transform(MacroLogicVNode::make(igvn, in1, in2, in3, mask, func, vt));
3120 }
3121 
3122 static uint extract_bit(uint func, uint pos) {
3123   return (func & (1 << pos)) >> pos;
3124 }
3125 
3126 //
3127 //  A macro logic node represents a truth table. It has 4 inputs,
3128 //  First three inputs corresponds to 3 columns of a truth table
3129 //  and fourth input captures the logic function.
3130 //
3131 //  eg.  fn = (in1 AND in2) OR in3;
3132 //
3133 //      MacroNode(in1,in2,in3,fn)
3134 //
3135 //  -----------------
3136 //  in1 in2 in3  fn
3137 //  -----------------
3138 //  0    0   0    0
3139 //  0    0   1    1
3140 //  0    1   0    0
3141 //  0    1   1    1
3142 //  1    0   0    0
3143 //  1    0   1    1
3144 //  1    1   0    1
3145 //  1    1   1    1
3146 //
3147 
3148 uint Compile::eval_macro_logic_op(uint func, uint in1 , uint in2, uint in3) {
3149   int res = 0;
3150   for (int i = 0; i < 8; i++) {
3151     int bit1 = extract_bit(in1, i);
3152     int bit2 = extract_bit(in2, i);
3153     int bit3 = extract_bit(in3, i);
3154 
3155     int func_bit_pos = (bit1 << 2 | bit2 << 1 | bit3);
3156     int func_bit = extract_bit(func, func_bit_pos);
3157 
3158     res |= func_bit << i;
3159   }
3160   return res;
3161 }
3162 
3163 static uint eval_operand(Node* n, ResourceHashtable<Node*,uint>& eval_map) {
3164   assert(n != nullptr, "");
3165   assert(eval_map.contains(n), "absent");
3166   return *(eval_map.get(n));
3167 }
3168 
3169 static void eval_operands(Node* n,
3170                           uint& func1, uint& func2, uint& func3,
3171                           ResourceHashtable<Node*,uint>& eval_map) {
3172   assert(is_vector_bitwise_op(n), "");
3173 
3174   if (is_vector_unary_bitwise_op(n)) {
3175     Node* opnd = n->in(1);
3176     if (VectorNode::is_vector_bitwise_not_pattern(n) && VectorNode::is_all_ones_vector(opnd)) {
3177       opnd = n->in(2);
3178     }
3179     func1 = eval_operand(opnd, eval_map);
3180   } else if (is_vector_binary_bitwise_op(n)) {
3181     func1 = eval_operand(n->in(1), eval_map);
3182     func2 = eval_operand(n->in(2), eval_map);
3183   } else {
3184     assert(is_vector_ternary_bitwise_op(n), "unknown operation");
3185     func1 = eval_operand(n->in(1), eval_map);
3186     func2 = eval_operand(n->in(2), eval_map);
3187     func3 = eval_operand(n->in(3), eval_map);
3188   }
3189 }
3190 
3191 uint Compile::compute_truth_table(Unique_Node_List& partition, Unique_Node_List& inputs) {
3192   assert(inputs.size() <= 3, "sanity");
3193   ResourceMark rm;
3194   uint res = 0;
3195   ResourceHashtable<Node*,uint> eval_map;
3196 
3197   // Populate precomputed functions for inputs.
3198   // Each input corresponds to one column of 3 input truth-table.
3199   uint input_funcs[] = { 0xAA,   // (_, _, c) -> c
3200                          0xCC,   // (_, b, _) -> b
3201                          0xF0 }; // (a, _, _) -> a
3202   for (uint i = 0; i < inputs.size(); i++) {
3203     eval_map.put(inputs.at(i), input_funcs[2-i]);
3204   }
3205 
3206   for (uint i = 0; i < partition.size(); i++) {
3207     Node* n = partition.at(i);
3208 
3209     uint func1 = 0, func2 = 0, func3 = 0;
3210     eval_operands(n, func1, func2, func3, eval_map);
3211 
3212     switch (n->Opcode()) {
3213       case Op_OrV:
3214         assert(func3 == 0, "not binary");
3215         res = func1 | func2;
3216         break;
3217       case Op_AndV:
3218         assert(func3 == 0, "not binary");
3219         res = func1 & func2;
3220         break;
3221       case Op_XorV:
3222         if (VectorNode::is_vector_bitwise_not_pattern(n)) {
3223           assert(func2 == 0 && func3 == 0, "not unary");
3224           res = (~func1) & 0xFF;
3225         } else {
3226           assert(func3 == 0, "not binary");
3227           res = func1 ^ func2;
3228         }
3229         break;
3230       case Op_MacroLogicV:
3231         // Ordering of inputs may change during evaluation of sub-tree
3232         // containing MacroLogic node as a child node, thus a re-evaluation
3233         // makes sure that function is evaluated in context of current
3234         // inputs.
3235         res = eval_macro_logic_op(n->in(4)->get_int(), func1, func2, func3);
3236         break;
3237 
3238       default: assert(false, "not supported: %s", n->Name());
3239     }
3240     assert(res <= 0xFF, "invalid");
3241     eval_map.put(n, res);
3242   }
3243   return res;
3244 }
3245 
3246 // Criteria under which nodes gets packed into a macro logic node:-
3247 //  1) Parent and both child nodes are all unmasked or masked with
3248 //     same predicates.
3249 //  2) Masked parent can be packed with left child if it is predicated
3250 //     and both have same predicates.
3251 //  3) Masked parent can be packed with right child if its un-predicated
3252 //     or has matching predication condition.
3253 //  4) An unmasked parent can be packed with an unmasked child.
3254 bool Compile::compute_logic_cone(Node* n, Unique_Node_List& partition, Unique_Node_List& inputs) {
3255   assert(partition.size() == 0, "not empty");
3256   assert(inputs.size() == 0, "not empty");
3257   if (is_vector_ternary_bitwise_op(n)) {
3258     return false;
3259   }
3260 
3261   bool is_unary_op = is_vector_unary_bitwise_op(n);
3262   if (is_unary_op) {
3263     assert(collect_unique_inputs(n, inputs) == 1, "not unary");
3264     return false; // too few inputs
3265   }
3266 
3267   bool pack_left_child = true;
3268   bool pack_right_child = true;
3269 
3270   bool left_child_LOP = is_vector_bitwise_op(n->in(1));
3271   bool right_child_LOP = is_vector_bitwise_op(n->in(2));
3272 
3273   int left_child_input_cnt = 0;
3274   int right_child_input_cnt = 0;
3275 
3276   bool parent_is_predicated = n->is_predicated_vector();
3277   bool left_child_predicated = n->in(1)->is_predicated_vector();
3278   bool right_child_predicated = n->in(2)->is_predicated_vector();
3279 
3280   Node* parent_pred = parent_is_predicated ? n->in(n->req()-1) : nullptr;
3281   Node* left_child_pred = left_child_predicated ? n->in(1)->in(n->in(1)->req()-1) : nullptr;
3282   Node* right_child_pred = right_child_predicated ? n->in(1)->in(n->in(1)->req()-1) : nullptr;
3283 
3284   do {
3285     if (pack_left_child && left_child_LOP &&
3286         ((!parent_is_predicated && !left_child_predicated) ||
3287         ((parent_is_predicated && left_child_predicated &&
3288           parent_pred == left_child_pred)))) {
3289        partition.push(n->in(1));
3290        left_child_input_cnt = collect_unique_inputs(n->in(1), inputs);
3291     } else {
3292        inputs.push(n->in(1));
3293        left_child_input_cnt = 1;
3294     }
3295 
3296     if (pack_right_child && right_child_LOP &&
3297         (!right_child_predicated ||
3298          (right_child_predicated && parent_is_predicated &&
3299           parent_pred == right_child_pred))) {
3300        partition.push(n->in(2));
3301        right_child_input_cnt = collect_unique_inputs(n->in(2), inputs);
3302     } else {
3303        inputs.push(n->in(2));
3304        right_child_input_cnt = 1;
3305     }
3306 
3307     if (inputs.size() > 3) {
3308       assert(partition.size() > 0, "");
3309       inputs.clear();
3310       partition.clear();
3311       if (left_child_input_cnt > right_child_input_cnt) {
3312         pack_left_child = false;
3313       } else {
3314         pack_right_child = false;
3315       }
3316     } else {
3317       break;
3318     }
3319   } while(true);
3320 
3321   if(partition.size()) {
3322     partition.push(n);
3323   }
3324 
3325   return (partition.size() == 2 || partition.size() == 3) &&
3326          (inputs.size()    == 2 || inputs.size()    == 3);
3327 }
3328 
3329 void Compile::process_logic_cone_root(PhaseIterGVN &igvn, Node *n, VectorSet &visited) {
3330   assert(is_vector_bitwise_op(n), "not a root");
3331 
3332   visited.set(n->_idx);
3333 
3334   // 1) Do a DFS walk over the logic cone.
3335   for (uint i = 1; i < n->req(); i++) {
3336     Node* in = n->in(i);
3337     if (!visited.test(in->_idx) && is_vector_bitwise_op(in)) {
3338       process_logic_cone_root(igvn, in, visited);
3339     }
3340   }
3341 
3342   // 2) Bottom up traversal: Merge node[s] with
3343   // the parent to form macro logic node.
3344   Unique_Node_List partition;
3345   Unique_Node_List inputs;
3346   if (compute_logic_cone(n, partition, inputs)) {
3347     const TypeVect* vt = n->bottom_type()->is_vect();
3348     Node* pn = partition.at(partition.size() - 1);
3349     Node* mask = pn->is_predicated_vector() ? pn->in(pn->req()-1) : nullptr;
3350     if (mask == nullptr ||
3351         Matcher::match_rule_supported_vector_masked(Op_MacroLogicV, vt->length(), vt->element_basic_type())) {
3352       Node* macro_logic = xform_to_MacroLogicV(igvn, vt, partition, inputs);
3353       VectorNode::trace_new_vector(macro_logic, "MacroLogic");
3354       igvn.replace_node(n, macro_logic);
3355     }
3356   }
3357 }
3358 
3359 void Compile::optimize_logic_cones(PhaseIterGVN &igvn) {
3360   ResourceMark rm;
3361   if (Matcher::match_rule_supported(Op_MacroLogicV)) {
3362     Unique_Node_List list;
3363     collect_logic_cone_roots(list);
3364 
3365     while (list.size() > 0) {
3366       Node* n = list.pop();
3367       const TypeVect* vt = n->bottom_type()->is_vect();
3368       bool supported = Matcher::match_rule_supported_vector(Op_MacroLogicV, vt->length(), vt->element_basic_type());
3369       if (supported) {
3370         VectorSet visited(comp_arena());
3371         process_logic_cone_root(igvn, n, visited);
3372       }
3373     }
3374   }
3375 }
3376 
3377 //------------------------------Code_Gen---------------------------------------
3378 // Given a graph, generate code for it
3379 void Compile::Code_Gen() {
3380   if (failing()) {
3381     return;
3382   }
3383 
3384   // Perform instruction selection.  You might think we could reclaim Matcher
3385   // memory PDQ, but actually the Matcher is used in generating spill code.
3386   // Internals of the Matcher (including some VectorSets) must remain live
3387   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
3388   // set a bit in reclaimed memory.
3389 
3390   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
3391   // nodes.  Mapping is only valid at the root of each matched subtree.
3392   NOT_PRODUCT( verify_graph_edges(); )
3393 
3394   Matcher matcher;
3395   _matcher = &matcher;
3396   {
3397     TracePhase tp("matcher", &timers[_t_matcher]);
3398     matcher.match();
3399     if (failing()) {
3400       return;
3401     }
3402   }
3403   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
3404   // nodes.  Mapping is only valid at the root of each matched subtree.
3405   NOT_PRODUCT( verify_graph_edges(); )
3406 
3407   // If you have too many nodes, or if matching has failed, bail out
3408   check_node_count(0, "out of nodes matching instructions");
3409   if (failing()) {
3410     return;
3411   }
3412 
3413   print_method(PHASE_MATCHING, 2);
3414 
3415   // Build a proper-looking CFG
3416   PhaseCFG cfg(node_arena(), root(), matcher);
3417   _cfg = &cfg;
3418   {
3419     TracePhase tp("scheduler", &timers[_t_scheduler]);
3420     bool success = cfg.do_global_code_motion();
3421     if (!success) {
3422       return;
3423     }
3424 
3425     print_method(PHASE_GLOBAL_CODE_MOTION, 2);
3426     NOT_PRODUCT( verify_graph_edges(); )
3427     cfg.verify();
3428   }
3429 
3430   PhaseChaitin regalloc(unique(), cfg, matcher, false);
3431   _regalloc = &regalloc;
3432   {
3433     TracePhase tp("regalloc", &timers[_t_registerAllocation]);
3434     // Perform register allocation.  After Chaitin, use-def chains are
3435     // no longer accurate (at spill code) and so must be ignored.
3436     // Node->LRG->reg mappings are still accurate.
3437     _regalloc->Register_Allocate();
3438 
3439     // Bail out if the allocator builds too many nodes
3440     if (failing()) {
3441       return;
3442     }
3443   }
3444 
3445   // Prior to register allocation we kept empty basic blocks in case the
3446   // the allocator needed a place to spill.  After register allocation we
3447   // are not adding any new instructions.  If any basic block is empty, we
3448   // can now safely remove it.
3449   {
3450     TracePhase tp("blockOrdering", &timers[_t_blockOrdering]);
3451     cfg.remove_empty_blocks();
3452     if (do_freq_based_layout()) {
3453       PhaseBlockLayout layout(cfg);
3454     } else {
3455       cfg.set_loop_alignment();
3456     }
3457     cfg.fixup_flow();
3458     cfg.remove_unreachable_blocks();
3459     cfg.verify_dominator_tree();
3460   }
3461 
3462   // Apply peephole optimizations
3463   if( OptoPeephole ) {
3464     TracePhase tp("peephole", &timers[_t_peephole]);
3465     PhasePeephole peep( _regalloc, cfg);
3466     peep.do_transform();
3467   }
3468 
3469   // Do late expand if CPU requires this.
3470   if (Matcher::require_postalloc_expand) {
3471     TracePhase tp("postalloc_expand", &timers[_t_postalloc_expand]);
3472     cfg.postalloc_expand(_regalloc);
3473   }
3474 
3475   // Convert Nodes to instruction bits in a buffer
3476   {
3477     TracePhase tp("output", &timers[_t_output]);
3478     PhaseOutput output;
3479     output.Output();
3480     if (failing())  return;
3481     output.install();
3482     print_method(PHASE_FINAL_CODE, 1); // Compile::_output is not null here
3483   }
3484 
3485   // He's dead, Jim.
3486   _cfg     = (PhaseCFG*)((intptr_t)0xdeadbeef);
3487   _regalloc = (PhaseChaitin*)((intptr_t)0xdeadbeef);
3488 }
3489 
3490 //------------------------------Final_Reshape_Counts---------------------------
3491 // This class defines counters to help identify when a method
3492 // may/must be executed using hardware with only 24-bit precision.
3493 struct Final_Reshape_Counts : public StackObj {
3494   int  _call_count;             // count non-inlined 'common' calls
3495   int  _float_count;            // count float ops requiring 24-bit precision
3496   int  _double_count;           // count double ops requiring more precision
3497   int  _java_call_count;        // count non-inlined 'java' calls
3498   int  _inner_loop_count;       // count loops which need alignment
3499   VectorSet _visited;           // Visitation flags
3500   Node_List _tests;             // Set of IfNodes & PCTableNodes
3501 
3502   Final_Reshape_Counts() :
3503     _call_count(0), _float_count(0), _double_count(0),
3504     _java_call_count(0), _inner_loop_count(0) { }
3505 
3506   void inc_call_count  () { _call_count  ++; }
3507   void inc_float_count () { _float_count ++; }
3508   void inc_double_count() { _double_count++; }
3509   void inc_java_call_count() { _java_call_count++; }
3510   void inc_inner_loop_count() { _inner_loop_count++; }
3511 
3512   int  get_call_count  () const { return _call_count  ; }
3513   int  get_float_count () const { return _float_count ; }
3514   int  get_double_count() const { return _double_count; }
3515   int  get_java_call_count() const { return _java_call_count; }
3516   int  get_inner_loop_count() const { return _inner_loop_count; }
3517 };
3518 
3519 // Eliminate trivially redundant StoreCMs and accumulate their
3520 // precedence edges.
3521 void Compile::eliminate_redundant_card_marks(Node* n) {
3522   assert(n->Opcode() == Op_StoreCM, "expected StoreCM");
3523   if (n->in(MemNode::Address)->outcnt() > 1) {
3524     // There are multiple users of the same address so it might be
3525     // possible to eliminate some of the StoreCMs
3526     Node* mem = n->in(MemNode::Memory);
3527     Node* adr = n->in(MemNode::Address);
3528     Node* val = n->in(MemNode::ValueIn);
3529     Node* prev = n;
3530     bool done = false;
3531     // Walk the chain of StoreCMs eliminating ones that match.  As
3532     // long as it's a chain of single users then the optimization is
3533     // safe.  Eliminating partially redundant StoreCMs would require
3534     // cloning copies down the other paths.
3535     while (mem->Opcode() == Op_StoreCM && mem->outcnt() == 1 && !done) {
3536       if (adr == mem->in(MemNode::Address) &&
3537           val == mem->in(MemNode::ValueIn)) {
3538         // redundant StoreCM
3539         if (mem->req() > MemNode::OopStore) {
3540           // Hasn't been processed by this code yet.
3541           n->add_prec(mem->in(MemNode::OopStore));
3542         } else {
3543           // Already converted to precedence edge
3544           for (uint i = mem->req(); i < mem->len(); i++) {
3545             // Accumulate any precedence edges
3546             if (mem->in(i) != nullptr) {
3547               n->add_prec(mem->in(i));
3548             }
3549           }
3550           // Everything above this point has been processed.
3551           done = true;
3552         }
3553         // Eliminate the previous StoreCM
3554         prev->set_req(MemNode::Memory, mem->in(MemNode::Memory));
3555         assert(mem->outcnt() == 0, "should be dead");
3556         mem->disconnect_inputs(this);
3557       } else {
3558         prev = mem;
3559       }
3560       mem = prev->in(MemNode::Memory);
3561     }
3562   }
3563 }
3564 
3565 
3566 //------------------------------final_graph_reshaping_impl----------------------
3567 // Implement items 1-5 from final_graph_reshaping below.
3568 void Compile::final_graph_reshaping_impl(Node *n, Final_Reshape_Counts& frc, Unique_Node_List& dead_nodes) {
3569 
3570   if ( n->outcnt() == 0 ) return; // dead node
3571   uint nop = n->Opcode();
3572 
3573   // Check for 2-input instruction with "last use" on right input.
3574   // Swap to left input.  Implements item (2).
3575   if( n->req() == 3 &&          // two-input instruction
3576       n->in(1)->outcnt() > 1 && // left use is NOT a last use
3577       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
3578       n->in(2)->outcnt() == 1 &&// right use IS a last use
3579       !n->in(2)->is_Con() ) {   // right use is not a constant
3580     // Check for commutative opcode
3581     switch( nop ) {
3582     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddL:
3583     case Op_MaxI:  case Op_MaxL:  case Op_MaxF:  case Op_MaxD:
3584     case Op_MinI:  case Op_MinL:  case Op_MinF:  case Op_MinD:
3585     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulL:
3586     case Op_AndL:  case Op_XorL:  case Op_OrL:
3587     case Op_AndI:  case Op_XorI:  case Op_OrI: {
3588       // Move "last use" input to left by swapping inputs
3589       n->swap_edges(1, 2);
3590       break;
3591     }
3592     default:
3593       break;
3594     }
3595   }
3596 
3597 #ifdef ASSERT
3598   if( n->is_Mem() ) {
3599     int alias_idx = get_alias_index(n->as_Mem()->adr_type());
3600     assert( n->in(0) != nullptr || alias_idx != Compile::AliasIdxRaw ||
3601             // oop will be recorded in oop map if load crosses safepoint
3602             n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
3603                              LoadNode::is_immutable_value(n->in(MemNode::Address))),
3604             "raw memory operations should have control edge");
3605   }
3606   if (n->is_MemBar()) {
3607     MemBarNode* mb = n->as_MemBar();
3608     if (mb->trailing_store() || mb->trailing_load_store()) {
3609       assert(mb->leading_membar()->trailing_membar() == mb, "bad membar pair");
3610       Node* mem = BarrierSet::barrier_set()->barrier_set_c2()->step_over_gc_barrier(mb->in(MemBarNode::Precedent));
3611       assert((mb->trailing_store() && mem->is_Store() && mem->as_Store()->is_release()) ||
3612              (mb->trailing_load_store() && mem->is_LoadStore()), "missing mem op");
3613     } else if (mb->leading()) {
3614       assert(mb->trailing_membar()->leading_membar() == mb, "bad membar pair");
3615     }
3616   }
3617 #endif
3618   // Count FPU ops and common calls, implements item (3)
3619   bool gc_handled = BarrierSet::barrier_set()->barrier_set_c2()->final_graph_reshaping(this, n, nop, dead_nodes);
3620   if (!gc_handled) {
3621     final_graph_reshaping_main_switch(n, frc, nop, dead_nodes);
3622   }
3623 
3624   // Collect CFG split points
3625   if (n->is_MultiBranch() && !n->is_RangeCheck()) {
3626     frc._tests.push(n);
3627   }
3628 }
3629 
3630 void Compile::final_graph_reshaping_main_switch(Node* n, Final_Reshape_Counts& frc, uint nop, Unique_Node_List& dead_nodes) {
3631   switch( nop ) {
3632   // Count all float operations that may use FPU
3633   case Op_AddF:
3634   case Op_SubF:
3635   case Op_MulF:
3636   case Op_DivF:
3637   case Op_NegF:
3638   case Op_ModF:
3639   case Op_ConvI2F:
3640   case Op_ConF:
3641   case Op_CmpF:
3642   case Op_CmpF3:
3643   case Op_StoreF:
3644   case Op_LoadF:
3645   // case Op_ConvL2F: // longs are split into 32-bit halves
3646     frc.inc_float_count();
3647     break;
3648 
3649   case Op_ConvF2D:
3650   case Op_ConvD2F:
3651     frc.inc_float_count();
3652     frc.inc_double_count();
3653     break;
3654 
3655   // Count all double operations that may use FPU
3656   case Op_AddD:
3657   case Op_SubD:
3658   case Op_MulD:
3659   case Op_DivD:
3660   case Op_NegD:
3661   case Op_ModD:
3662   case Op_ConvI2D:
3663   case Op_ConvD2I:
3664   // case Op_ConvL2D: // handled by leaf call
3665   // case Op_ConvD2L: // handled by leaf call
3666   case Op_ConD:
3667   case Op_CmpD:
3668   case Op_CmpD3:
3669   case Op_StoreD:
3670   case Op_LoadD:
3671   case Op_LoadD_unaligned:
3672     frc.inc_double_count();
3673     break;
3674   case Op_Opaque1:              // Remove Opaque Nodes before matching
3675   case Op_Opaque3:
3676     n->subsume_by(n->in(1), this);
3677     break;
3678   case Op_CallStaticJava:
3679   case Op_CallJava:
3680   case Op_CallDynamicJava:
3681     frc.inc_java_call_count(); // Count java call site;
3682   case Op_CallRuntime:
3683   case Op_CallLeaf:
3684   case Op_CallLeafVector:
3685   case Op_CallLeafNoFP: {
3686     assert (n->is_Call(), "");
3687     CallNode *call = n->as_Call();
3688     // Count call sites where the FP mode bit would have to be flipped.
3689     // Do not count uncommon runtime calls:
3690     // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
3691     // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
3692     if (!call->is_CallStaticJava() || !call->as_CallStaticJava()->_name) {
3693       frc.inc_call_count();   // Count the call site
3694     } else {                  // See if uncommon argument is shared
3695       Node *n = call->in(TypeFunc::Parms);
3696       int nop = n->Opcode();
3697       // Clone shared simple arguments to uncommon calls, item (1).
3698       if (n->outcnt() > 1 &&
3699           !n->is_Proj() &&
3700           nop != Op_CreateEx &&
3701           nop != Op_CheckCastPP &&
3702           nop != Op_DecodeN &&
3703           nop != Op_DecodeNKlass &&
3704           !n->is_Mem() &&
3705           !n->is_Phi()) {
3706         Node *x = n->clone();
3707         call->set_req(TypeFunc::Parms, x);
3708       }
3709     }
3710     break;
3711   }
3712 
3713   case Op_StoreCM:
3714     {
3715       // Convert OopStore dependence into precedence edge
3716       Node* prec = n->in(MemNode::OopStore);
3717       n->del_req(MemNode::OopStore);
3718       if (prec->is_MergeMem()) {
3719         MergeMemNode* mm = prec->as_MergeMem();
3720         Node* base = mm->base_memory();
3721         for (int i = AliasIdxRaw + 1; i < num_alias_types(); i++) {
3722           const TypePtr* adr_type = get_adr_type(i);
3723           if (adr_type->is_flat()) {
3724             Node* m = mm->memory_at(i);
3725             n->add_prec(m);
3726           }
3727         }
3728         if (mm->outcnt() == 0) {
3729           mm->disconnect_inputs(this);
3730         }
3731       } else {
3732         n->add_prec(prec);
3733       }
3734       eliminate_redundant_card_marks(n);
3735     }
3736 
3737     // fall through
3738 
3739   case Op_StoreB:
3740   case Op_StoreC:
3741   case Op_StoreI:
3742   case Op_StoreL:
3743   case Op_CompareAndSwapB:
3744   case Op_CompareAndSwapS:
3745   case Op_CompareAndSwapI:
3746   case Op_CompareAndSwapL:
3747   case Op_CompareAndSwapP:
3748   case Op_CompareAndSwapN:
3749   case Op_WeakCompareAndSwapB:
3750   case Op_WeakCompareAndSwapS:
3751   case Op_WeakCompareAndSwapI:
3752   case Op_WeakCompareAndSwapL:
3753   case Op_WeakCompareAndSwapP:
3754   case Op_WeakCompareAndSwapN:
3755   case Op_CompareAndExchangeB:
3756   case Op_CompareAndExchangeS:
3757   case Op_CompareAndExchangeI:
3758   case Op_CompareAndExchangeL:
3759   case Op_CompareAndExchangeP:
3760   case Op_CompareAndExchangeN:
3761   case Op_GetAndAddS:
3762   case Op_GetAndAddB:
3763   case Op_GetAndAddI:
3764   case Op_GetAndAddL:
3765   case Op_GetAndSetS:
3766   case Op_GetAndSetB:
3767   case Op_GetAndSetI:
3768   case Op_GetAndSetL:
3769   case Op_GetAndSetP:
3770   case Op_GetAndSetN:
3771   case Op_StoreP:
3772   case Op_StoreN:
3773   case Op_StoreNKlass:
3774   case Op_LoadB:
3775   case Op_LoadUB:
3776   case Op_LoadUS:
3777   case Op_LoadI:
3778   case Op_LoadKlass:
3779   case Op_LoadNKlass:
3780   case Op_LoadL:
3781   case Op_LoadL_unaligned:
3782   case Op_LoadP:
3783   case Op_LoadN:
3784   case Op_LoadRange:
3785   case Op_LoadS:
3786     break;
3787 
3788   case Op_AddP: {               // Assert sane base pointers
3789     Node *addp = n->in(AddPNode::Address);
3790     assert( !addp->is_AddP() ||
3791             addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
3792             addp->in(AddPNode::Base) == n->in(AddPNode::Base),
3793             "Base pointers must match (addp %u)", addp->_idx );
3794 #ifdef _LP64
3795     if ((UseCompressedOops || UseCompressedClassPointers) &&
3796         addp->Opcode() == Op_ConP &&
3797         addp == n->in(AddPNode::Base) &&
3798         n->in(AddPNode::Offset)->is_Con()) {
3799       // If the transformation of ConP to ConN+DecodeN is beneficial depends
3800       // on the platform and on the compressed oops mode.
3801       // Use addressing with narrow klass to load with offset on x86.
3802       // Some platforms can use the constant pool to load ConP.
3803       // Do this transformation here since IGVN will convert ConN back to ConP.
3804       const Type* t = addp->bottom_type();
3805       bool is_oop   = t->isa_oopptr() != nullptr;
3806       bool is_klass = t->isa_klassptr() != nullptr;
3807 
3808       if ((is_oop   && Matcher::const_oop_prefer_decode()  ) ||
3809           (is_klass && Matcher::const_klass_prefer_decode())) {
3810         Node* nn = nullptr;
3811 
3812         int op = is_oop ? Op_ConN : Op_ConNKlass;
3813 
3814         // Look for existing ConN node of the same exact type.
3815         Node* r  = root();
3816         uint cnt = r->outcnt();
3817         for (uint i = 0; i < cnt; i++) {
3818           Node* m = r->raw_out(i);
3819           if (m!= nullptr && m->Opcode() == op &&
3820               m->bottom_type()->make_ptr() == t) {
3821             nn = m;
3822             break;
3823           }
3824         }
3825         if (nn != nullptr) {
3826           // Decode a narrow oop to match address
3827           // [R12 + narrow_oop_reg<<3 + offset]
3828           if (is_oop) {
3829             nn = new DecodeNNode(nn, t);
3830           } else {
3831             nn = new DecodeNKlassNode(nn, t);
3832           }
3833           // Check for succeeding AddP which uses the same Base.
3834           // Otherwise we will run into the assertion above when visiting that guy.
3835           for (uint i = 0; i < n->outcnt(); ++i) {
3836             Node *out_i = n->raw_out(i);
3837             if (out_i && out_i->is_AddP() && out_i->in(AddPNode::Base) == addp) {
3838               out_i->set_req(AddPNode::Base, nn);
3839 #ifdef ASSERT
3840               for (uint j = 0; j < out_i->outcnt(); ++j) {
3841                 Node *out_j = out_i->raw_out(j);
3842                 assert(out_j == nullptr || !out_j->is_AddP() || out_j->in(AddPNode::Base) != addp,
3843                        "more than 2 AddP nodes in a chain (out_j %u)", out_j->_idx);
3844               }
3845 #endif
3846             }
3847           }
3848           n->set_req(AddPNode::Base, nn);
3849           n->set_req(AddPNode::Address, nn);
3850           if (addp->outcnt() == 0) {
3851             addp->disconnect_inputs(this);
3852           }
3853         }
3854       }
3855     }
3856 #endif
3857     break;
3858   }
3859 
3860   case Op_CastPP: {
3861     // Remove CastPP nodes to gain more freedom during scheduling but
3862     // keep the dependency they encode as control or precedence edges
3863     // (if control is set already) on memory operations. Some CastPP
3864     // nodes don't have a control (don't carry a dependency): skip
3865     // those.
3866     if (n->in(0) != nullptr) {
3867       ResourceMark rm;
3868       Unique_Node_List wq;
3869       wq.push(n);
3870       for (uint next = 0; next < wq.size(); ++next) {
3871         Node *m = wq.at(next);
3872         for (DUIterator_Fast imax, i = m->fast_outs(imax); i < imax; i++) {
3873           Node* use = m->fast_out(i);
3874           if (use->is_Mem() || use->is_EncodeNarrowPtr()) {
3875             use->ensure_control_or_add_prec(n->in(0));
3876           } else {
3877             switch(use->Opcode()) {
3878             case Op_AddP:
3879             case Op_DecodeN:
3880             case Op_DecodeNKlass:
3881             case Op_CheckCastPP:
3882             case Op_CastPP:
3883               wq.push(use);
3884               break;
3885             }
3886           }
3887         }
3888       }
3889     }
3890     const bool is_LP64 = LP64_ONLY(true) NOT_LP64(false);
3891     if (is_LP64 && n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
3892       Node* in1 = n->in(1);
3893       const Type* t = n->bottom_type();
3894       Node* new_in1 = in1->clone();
3895       new_in1->as_DecodeN()->set_type(t);
3896 
3897       if (!Matcher::narrow_oop_use_complex_address()) {
3898         //
3899         // x86, ARM and friends can handle 2 adds in addressing mode
3900         // and Matcher can fold a DecodeN node into address by using
3901         // a narrow oop directly and do implicit null check in address:
3902         //
3903         // [R12 + narrow_oop_reg<<3 + offset]
3904         // NullCheck narrow_oop_reg
3905         //
3906         // On other platforms (Sparc) we have to keep new DecodeN node and
3907         // use it to do implicit null check in address:
3908         //
3909         // decode_not_null narrow_oop_reg, base_reg
3910         // [base_reg + offset]
3911         // NullCheck base_reg
3912         //
3913         // Pin the new DecodeN node to non-null path on these platform (Sparc)
3914         // to keep the information to which null check the new DecodeN node
3915         // corresponds to use it as value in implicit_null_check().
3916         //
3917         new_in1->set_req(0, n->in(0));
3918       }
3919 
3920       n->subsume_by(new_in1, this);
3921       if (in1->outcnt() == 0) {
3922         in1->disconnect_inputs(this);
3923       }
3924     } else {
3925       n->subsume_by(n->in(1), this);
3926       if (n->outcnt() == 0) {
3927         n->disconnect_inputs(this);
3928       }
3929     }
3930     break;
3931   }
3932 #ifdef _LP64
3933   case Op_CmpP:
3934     // Do this transformation here to preserve CmpPNode::sub() and
3935     // other TypePtr related Ideal optimizations (for example, ptr nullness).
3936     if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
3937       Node* in1 = n->in(1);
3938       Node* in2 = n->in(2);
3939       if (!in1->is_DecodeNarrowPtr()) {
3940         in2 = in1;
3941         in1 = n->in(2);
3942       }
3943       assert(in1->is_DecodeNarrowPtr(), "sanity");
3944 
3945       Node* new_in2 = nullptr;
3946       if (in2->is_DecodeNarrowPtr()) {
3947         assert(in2->Opcode() == in1->Opcode(), "must be same node type");
3948         new_in2 = in2->in(1);
3949       } else if (in2->Opcode() == Op_ConP) {
3950         const Type* t = in2->bottom_type();
3951         if (t == TypePtr::NULL_PTR) {
3952           assert(in1->is_DecodeN(), "compare klass to null?");
3953           // Don't convert CmpP null check into CmpN if compressed
3954           // oops implicit null check is not generated.
3955           // This will allow to generate normal oop implicit null check.
3956           if (Matcher::gen_narrow_oop_implicit_null_checks())
3957             new_in2 = ConNode::make(TypeNarrowOop::NULL_PTR);
3958           //
3959           // This transformation together with CastPP transformation above
3960           // will generated code for implicit null checks for compressed oops.
3961           //
3962           // The original code after Optimize()
3963           //
3964           //    LoadN memory, narrow_oop_reg
3965           //    decode narrow_oop_reg, base_reg
3966           //    CmpP base_reg, nullptr
3967           //    CastPP base_reg // NotNull
3968           //    Load [base_reg + offset], val_reg
3969           //
3970           // after these transformations will be
3971           //
3972           //    LoadN memory, narrow_oop_reg
3973           //    CmpN narrow_oop_reg, nullptr
3974           //    decode_not_null narrow_oop_reg, base_reg
3975           //    Load [base_reg + offset], val_reg
3976           //
3977           // and the uncommon path (== nullptr) will use narrow_oop_reg directly
3978           // since narrow oops can be used in debug info now (see the code in
3979           // final_graph_reshaping_walk()).
3980           //
3981           // At the end the code will be matched to
3982           // on x86:
3983           //
3984           //    Load_narrow_oop memory, narrow_oop_reg
3985           //    Load [R12 + narrow_oop_reg<<3 + offset], val_reg
3986           //    NullCheck narrow_oop_reg
3987           //
3988           // and on sparc:
3989           //
3990           //    Load_narrow_oop memory, narrow_oop_reg
3991           //    decode_not_null narrow_oop_reg, base_reg
3992           //    Load [base_reg + offset], val_reg
3993           //    NullCheck base_reg
3994           //
3995         } else if (t->isa_oopptr()) {
3996           new_in2 = ConNode::make(t->make_narrowoop());
3997         } else if (t->isa_klassptr()) {
3998           new_in2 = ConNode::make(t->make_narrowklass());
3999         }
4000       }
4001       if (new_in2 != nullptr) {
4002         Node* cmpN = new CmpNNode(in1->in(1), new_in2);
4003         n->subsume_by(cmpN, this);
4004         if (in1->outcnt() == 0) {
4005           in1->disconnect_inputs(this);
4006         }
4007         if (in2->outcnt() == 0) {
4008           in2->disconnect_inputs(this);
4009         }
4010       }
4011     }
4012     break;
4013 
4014   case Op_DecodeN:
4015   case Op_DecodeNKlass:
4016     assert(!n->in(1)->is_EncodeNarrowPtr(), "should be optimized out");
4017     // DecodeN could be pinned when it can't be fold into
4018     // an address expression, see the code for Op_CastPP above.
4019     assert(n->in(0) == nullptr || (UseCompressedOops && !Matcher::narrow_oop_use_complex_address()), "no control");
4020     break;
4021 
4022   case Op_EncodeP:
4023   case Op_EncodePKlass: {
4024     Node* in1 = n->in(1);
4025     if (in1->is_DecodeNarrowPtr()) {
4026       n->subsume_by(in1->in(1), this);
4027     } else if (in1->Opcode() == Op_ConP) {
4028       const Type* t = in1->bottom_type();
4029       if (t == TypePtr::NULL_PTR) {
4030         assert(t->isa_oopptr(), "null klass?");
4031         n->subsume_by(ConNode::make(TypeNarrowOop::NULL_PTR), this);
4032       } else if (t->isa_oopptr()) {
4033         n->subsume_by(ConNode::make(t->make_narrowoop()), this);
4034       } else if (t->isa_klassptr()) {
4035         n->subsume_by(ConNode::make(t->make_narrowklass()), this);
4036       }
4037     }
4038     if (in1->outcnt() == 0) {
4039       in1->disconnect_inputs(this);
4040     }
4041     break;
4042   }
4043 
4044   case Op_Proj: {
4045     if (OptimizeStringConcat || IncrementalInline) {
4046       ProjNode* proj = n->as_Proj();
4047       if (proj->_is_io_use) {
4048         assert(proj->_con == TypeFunc::I_O || proj->_con == TypeFunc::Memory, "");
4049         // Separate projections were used for the exception path which
4050         // are normally removed by a late inline.  If it wasn't inlined
4051         // then they will hang around and should just be replaced with
4052         // the original one. Merge them.
4053         Node* non_io_proj = proj->in(0)->as_Multi()->proj_out_or_null(proj->_con, false /*is_io_use*/);
4054         if (non_io_proj  != nullptr) {
4055           proj->subsume_by(non_io_proj , this);
4056         }
4057       }
4058     }
4059     break;
4060   }
4061 
4062   case Op_Phi:
4063     if (n->as_Phi()->bottom_type()->isa_narrowoop() || n->as_Phi()->bottom_type()->isa_narrowklass()) {
4064       // The EncodeP optimization may create Phi with the same edges
4065       // for all paths. It is not handled well by Register Allocator.
4066       Node* unique_in = n->in(1);
4067       assert(unique_in != nullptr, "");
4068       uint cnt = n->req();
4069       for (uint i = 2; i < cnt; i++) {
4070         Node* m = n->in(i);
4071         assert(m != nullptr, "");
4072         if (unique_in != m)
4073           unique_in = nullptr;
4074       }
4075       if (unique_in != nullptr) {
4076         n->subsume_by(unique_in, this);
4077       }
4078     }
4079     break;
4080 
4081 #endif
4082 
4083 #ifdef ASSERT
4084   case Op_CastII:
4085     // Verify that all range check dependent CastII nodes were removed.
4086     if (n->isa_CastII()->has_range_check()) {
4087       n->dump(3);
4088       assert(false, "Range check dependent CastII node was not removed");
4089     }
4090     break;
4091 #endif
4092 
4093   case Op_ModI:
4094     if (UseDivMod) {
4095       // Check if a%b and a/b both exist
4096       Node* d = n->find_similar(Op_DivI);
4097       if (d) {
4098         // Replace them with a fused divmod if supported
4099         if (Matcher::has_match_rule(Op_DivModI)) {
4100           DivModINode* divmod = DivModINode::make(n);
4101           d->subsume_by(divmod->div_proj(), this);
4102           n->subsume_by(divmod->mod_proj(), this);
4103         } else {
4104           // replace a%b with a-((a/b)*b)
4105           Node* mult = new MulINode(d, d->in(2));
4106           Node* sub  = new SubINode(d->in(1), mult);
4107           n->subsume_by(sub, this);
4108         }
4109       }
4110     }
4111     break;
4112 
4113   case Op_ModL:
4114     if (UseDivMod) {
4115       // Check if a%b and a/b both exist
4116       Node* d = n->find_similar(Op_DivL);
4117       if (d) {
4118         // Replace them with a fused divmod if supported
4119         if (Matcher::has_match_rule(Op_DivModL)) {
4120           DivModLNode* divmod = DivModLNode::make(n);
4121           d->subsume_by(divmod->div_proj(), this);
4122           n->subsume_by(divmod->mod_proj(), this);
4123         } else {
4124           // replace a%b with a-((a/b)*b)
4125           Node* mult = new MulLNode(d, d->in(2));
4126           Node* sub  = new SubLNode(d->in(1), mult);
4127           n->subsume_by(sub, this);
4128         }
4129       }
4130     }
4131     break;
4132 
4133   case Op_UModI:
4134     if (UseDivMod) {
4135       // Check if a%b and a/b both exist
4136       Node* d = n->find_similar(Op_UDivI);
4137       if (d) {
4138         // Replace them with a fused unsigned divmod if supported
4139         if (Matcher::has_match_rule(Op_UDivModI)) {
4140           UDivModINode* divmod = UDivModINode::make(n);
4141           d->subsume_by(divmod->div_proj(), this);
4142           n->subsume_by(divmod->mod_proj(), this);
4143         } else {
4144           // replace a%b with a-((a/b)*b)
4145           Node* mult = new MulINode(d, d->in(2));
4146           Node* sub  = new SubINode(d->in(1), mult);
4147           n->subsume_by(sub, this);
4148         }
4149       }
4150     }
4151     break;
4152 
4153   case Op_UModL:
4154     if (UseDivMod) {
4155       // Check if a%b and a/b both exist
4156       Node* d = n->find_similar(Op_UDivL);
4157       if (d) {
4158         // Replace them with a fused unsigned divmod if supported
4159         if (Matcher::has_match_rule(Op_UDivModL)) {
4160           UDivModLNode* divmod = UDivModLNode::make(n);
4161           d->subsume_by(divmod->div_proj(), this);
4162           n->subsume_by(divmod->mod_proj(), this);
4163         } else {
4164           // replace a%b with a-((a/b)*b)
4165           Node* mult = new MulLNode(d, d->in(2));
4166           Node* sub  = new SubLNode(d->in(1), mult);
4167           n->subsume_by(sub, this);
4168         }
4169       }
4170     }
4171     break;
4172 
4173   case Op_LoadVector:
4174   case Op_StoreVector:
4175   case Op_LoadVectorGather:
4176   case Op_StoreVectorScatter:
4177   case Op_LoadVectorGatherMasked:
4178   case Op_StoreVectorScatterMasked:
4179   case Op_VectorCmpMasked:
4180   case Op_VectorMaskGen:
4181   case Op_LoadVectorMasked:
4182   case Op_StoreVectorMasked:
4183     break;
4184 
4185   case Op_AddReductionVI:
4186   case Op_AddReductionVL:
4187   case Op_AddReductionVF:
4188   case Op_AddReductionVD:
4189   case Op_MulReductionVI:
4190   case Op_MulReductionVL:
4191   case Op_MulReductionVF:
4192   case Op_MulReductionVD:
4193   case Op_MinReductionV:
4194   case Op_MaxReductionV:
4195   case Op_AndReductionV:
4196   case Op_OrReductionV:
4197   case Op_XorReductionV:
4198     break;
4199 
4200   case Op_PackB:
4201   case Op_PackS:
4202   case Op_PackI:
4203   case Op_PackF:
4204   case Op_PackL:
4205   case Op_PackD:
4206     if (n->req()-1 > 2) {
4207       // Replace many operand PackNodes with a binary tree for matching
4208       PackNode* p = (PackNode*) n;
4209       Node* btp = p->binary_tree_pack(1, n->req());
4210       n->subsume_by(btp, this);
4211     }
4212     break;
4213   case Op_Loop:
4214     assert(!n->as_Loop()->is_loop_nest_inner_loop() || _loop_opts_cnt == 0, "should have been turned into a counted loop");
4215   case Op_CountedLoop:
4216   case Op_LongCountedLoop:
4217   case Op_OuterStripMinedLoop:
4218     if (n->as_Loop()->is_inner_loop()) {
4219       frc.inc_inner_loop_count();
4220     }
4221     n->as_Loop()->verify_strip_mined(0);
4222     break;
4223   case Op_LShiftI:
4224   case Op_RShiftI:
4225   case Op_URShiftI:
4226   case Op_LShiftL:
4227   case Op_RShiftL:
4228   case Op_URShiftL:
4229     if (Matcher::need_masked_shift_count) {
4230       // The cpu's shift instructions don't restrict the count to the
4231       // lower 5/6 bits. We need to do the masking ourselves.
4232       Node* in2 = n->in(2);
4233       juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
4234       const TypeInt* t = in2->find_int_type();
4235       if (t != nullptr && t->is_con()) {
4236         juint shift = t->get_con();
4237         if (shift > mask) { // Unsigned cmp
4238           n->set_req(2, ConNode::make(TypeInt::make(shift & mask)));
4239         }
4240       } else {
4241         if (t == nullptr || t->_lo < 0 || t->_hi > (int)mask) {
4242           Node* shift = new AndINode(in2, ConNode::make(TypeInt::make(mask)));
4243           n->set_req(2, shift);
4244         }
4245       }
4246       if (in2->outcnt() == 0) { // Remove dead node
4247         in2->disconnect_inputs(this);
4248       }
4249     }
4250     break;
4251   case Op_MemBarStoreStore:
4252   case Op_MemBarRelease:
4253     // Break the link with AllocateNode: it is no longer useful and
4254     // confuses register allocation.
4255     if (n->req() > MemBarNode::Precedent) {
4256       n->set_req(MemBarNode::Precedent, top());
4257     }
4258     break;
4259   case Op_MemBarAcquire: {
4260     if (n->as_MemBar()->trailing_load() && n->req() > MemBarNode::Precedent) {
4261       // At parse time, the trailing MemBarAcquire for a volatile load
4262       // is created with an edge to the load. After optimizations,
4263       // that input may be a chain of Phis. If those phis have no
4264       // other use, then the MemBarAcquire keeps them alive and
4265       // register allocation can be confused.
4266       dead_nodes.push(n->in(MemBarNode::Precedent));
4267       n->set_req(MemBarNode::Precedent, top());
4268     }
4269     break;
4270   }
4271   case Op_Blackhole:
4272     break;
4273   case Op_RangeCheck: {
4274     RangeCheckNode* rc = n->as_RangeCheck();
4275     Node* iff = new IfNode(rc->in(0), rc->in(1), rc->_prob, rc->_fcnt);
4276     n->subsume_by(iff, this);
4277     frc._tests.push(iff);
4278     break;
4279   }
4280   case Op_ConvI2L: {
4281     if (!Matcher::convi2l_type_required) {
4282       // Code generation on some platforms doesn't need accurate
4283       // ConvI2L types. Widening the type can help remove redundant
4284       // address computations.
4285       n->as_Type()->set_type(TypeLong::INT);
4286       ResourceMark rm;
4287       Unique_Node_List wq;
4288       wq.push(n);
4289       for (uint next = 0; next < wq.size(); next++) {
4290         Node *m = wq.at(next);
4291 
4292         for(;;) {
4293           // Loop over all nodes with identical inputs edges as m
4294           Node* k = m->find_similar(m->Opcode());
4295           if (k == nullptr) {
4296             break;
4297           }
4298           // Push their uses so we get a chance to remove node made
4299           // redundant
4300           for (DUIterator_Fast imax, i = k->fast_outs(imax); i < imax; i++) {
4301             Node* u = k->fast_out(i);
4302             if (u->Opcode() == Op_LShiftL ||
4303                 u->Opcode() == Op_AddL ||
4304                 u->Opcode() == Op_SubL ||
4305                 u->Opcode() == Op_AddP) {
4306               wq.push(u);
4307             }
4308           }
4309           // Replace all nodes with identical edges as m with m
4310           k->subsume_by(m, this);
4311         }
4312       }
4313     }
4314     break;
4315   }
4316   case Op_CmpUL: {
4317     if (!Matcher::has_match_rule(Op_CmpUL)) {
4318       // No support for unsigned long comparisons
4319       ConINode* sign_pos = new ConINode(TypeInt::make(BitsPerLong - 1));
4320       Node* sign_bit_mask = new RShiftLNode(n->in(1), sign_pos);
4321       Node* orl = new OrLNode(n->in(1), sign_bit_mask);
4322       ConLNode* remove_sign_mask = new ConLNode(TypeLong::make(max_jlong));
4323       Node* andl = new AndLNode(orl, remove_sign_mask);
4324       Node* cmp = new CmpLNode(andl, n->in(2));
4325       n->subsume_by(cmp, this);
4326     }
4327     break;
4328   }
4329 #ifdef ASSERT
4330   case Op_InlineType: {
4331     n->dump(-1);
4332     assert(false, "inline type node was not removed");
4333     break;
4334   }
4335 #endif
4336   default:
4337     assert(!n->is_Call(), "");
4338     assert(!n->is_Mem(), "");
4339     assert(nop != Op_ProfileBoolean, "should be eliminated during IGVN");
4340     break;
4341   }
4342 }
4343 
4344 //------------------------------final_graph_reshaping_walk---------------------
4345 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
4346 // requires that the walk visits a node's inputs before visiting the node.
4347 void Compile::final_graph_reshaping_walk(Node_Stack& nstack, Node* root, Final_Reshape_Counts& frc, Unique_Node_List& dead_nodes) {
4348   Unique_Node_List sfpt;
4349 
4350   frc._visited.set(root->_idx); // first, mark node as visited
4351   uint cnt = root->req();
4352   Node *n = root;
4353   uint  i = 0;
4354   while (true) {
4355     if (i < cnt) {
4356       // Place all non-visited non-null inputs onto stack
4357       Node* m = n->in(i);
4358       ++i;
4359       if (m != nullptr && !frc._visited.test_set(m->_idx)) {
4360         if (m->is_SafePoint() && m->as_SafePoint()->jvms() != nullptr) {
4361           // compute worst case interpreter size in case of a deoptimization
4362           update_interpreter_frame_size(m->as_SafePoint()->jvms()->interpreter_frame_size());
4363 
4364           sfpt.push(m);
4365         }
4366         cnt = m->req();
4367         nstack.push(n, i); // put on stack parent and next input's index
4368         n = m;
4369         i = 0;
4370       }
4371     } else {
4372       // Now do post-visit work
4373       final_graph_reshaping_impl(n, frc, dead_nodes);
4374       if (nstack.is_empty())
4375         break;             // finished
4376       n = nstack.node();   // Get node from stack
4377       cnt = n->req();
4378       i = nstack.index();
4379       nstack.pop();        // Shift to the next node on stack
4380     }
4381   }
4382 
4383   // Skip next transformation if compressed oops are not used.
4384   if ((UseCompressedOops && !Matcher::gen_narrow_oop_implicit_null_checks()) ||
4385       (!UseCompressedOops && !UseCompressedClassPointers))
4386     return;
4387 
4388   // Go over safepoints nodes to skip DecodeN/DecodeNKlass nodes for debug edges.
4389   // It could be done for an uncommon traps or any safepoints/calls
4390   // if the DecodeN/DecodeNKlass node is referenced only in a debug info.
4391   while (sfpt.size() > 0) {
4392     n = sfpt.pop();
4393     JVMState *jvms = n->as_SafePoint()->jvms();
4394     assert(jvms != nullptr, "sanity");
4395     int start = jvms->debug_start();
4396     int end   = n->req();
4397     bool is_uncommon = (n->is_CallStaticJava() &&
4398                         n->as_CallStaticJava()->uncommon_trap_request() != 0);
4399     for (int j = start; j < end; j++) {
4400       Node* in = n->in(j);
4401       if (in->is_DecodeNarrowPtr()) {
4402         bool safe_to_skip = true;
4403         if (!is_uncommon ) {
4404           // Is it safe to skip?
4405           for (uint i = 0; i < in->outcnt(); i++) {
4406             Node* u = in->raw_out(i);
4407             if (!u->is_SafePoint() ||
4408                 (u->is_Call() && u->as_Call()->has_non_debug_use(n))) {
4409               safe_to_skip = false;
4410             }
4411           }
4412         }
4413         if (safe_to_skip) {
4414           n->set_req(j, in->in(1));
4415         }
4416         if (in->outcnt() == 0) {
4417           in->disconnect_inputs(this);
4418         }
4419       }
4420     }
4421   }
4422 }
4423 
4424 //------------------------------final_graph_reshaping--------------------------
4425 // Final Graph Reshaping.
4426 //
4427 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
4428 //     and not commoned up and forced early.  Must come after regular
4429 //     optimizations to avoid GVN undoing the cloning.  Clone constant
4430 //     inputs to Loop Phis; these will be split by the allocator anyways.
4431 //     Remove Opaque nodes.
4432 // (2) Move last-uses by commutative operations to the left input to encourage
4433 //     Intel update-in-place two-address operations and better register usage
4434 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
4435 //     calls canonicalizing them back.
4436 // (3) Count the number of double-precision FP ops, single-precision FP ops
4437 //     and call sites.  On Intel, we can get correct rounding either by
4438 //     forcing singles to memory (requires extra stores and loads after each
4439 //     FP bytecode) or we can set a rounding mode bit (requires setting and
4440 //     clearing the mode bit around call sites).  The mode bit is only used
4441 //     if the relative frequency of single FP ops to calls is low enough.
4442 //     This is a key transform for SPEC mpeg_audio.
4443 // (4) Detect infinite loops; blobs of code reachable from above but not
4444 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
4445 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
4446 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
4447 //     Detection is by looking for IfNodes where only 1 projection is
4448 //     reachable from below or CatchNodes missing some targets.
4449 // (5) Assert for insane oop offsets in debug mode.
4450 
4451 bool Compile::final_graph_reshaping() {
4452   // an infinite loop may have been eliminated by the optimizer,
4453   // in which case the graph will be empty.
4454   if (root()->req() == 1) {
4455     // Do not compile method that is only a trivial infinite loop,
4456     // since the content of the loop may have been eliminated.
4457     record_method_not_compilable("trivial infinite loop");
4458     return true;
4459   }
4460 
4461   // Expensive nodes have their control input set to prevent the GVN
4462   // from freely commoning them. There's no GVN beyond this point so
4463   // no need to keep the control input. We want the expensive nodes to
4464   // be freely moved to the least frequent code path by gcm.
4465   assert(OptimizeExpensiveOps || expensive_count() == 0, "optimization off but list non empty?");
4466   for (int i = 0; i < expensive_count(); i++) {
4467     _expensive_nodes.at(i)->set_req(0, nullptr);
4468   }
4469 
4470   Final_Reshape_Counts frc;
4471 
4472   // Visit everybody reachable!
4473   // Allocate stack of size C->live_nodes()/2 to avoid frequent realloc
4474   Node_Stack nstack(live_nodes() >> 1);
4475   Unique_Node_List dead_nodes;
4476   final_graph_reshaping_walk(nstack, root(), frc, dead_nodes);
4477 
4478   // Check for unreachable (from below) code (i.e., infinite loops).
4479   for( uint i = 0; i < frc._tests.size(); i++ ) {
4480     MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
4481     // Get number of CFG targets.
4482     // Note that PCTables include exception targets after calls.
4483     uint required_outcnt = n->required_outcnt();
4484     if (n->outcnt() != required_outcnt) {
4485       // Check for a few special cases.  Rethrow Nodes never take the
4486       // 'fall-thru' path, so expected kids is 1 less.
4487       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
4488         if (n->in(0)->in(0)->is_Call()) {
4489           CallNode* call = n->in(0)->in(0)->as_Call();
4490           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
4491             required_outcnt--;      // Rethrow always has 1 less kid
4492           } else if (call->req() > TypeFunc::Parms &&
4493                      call->is_CallDynamicJava()) {
4494             // Check for null receiver. In such case, the optimizer has
4495             // detected that the virtual call will always result in a null
4496             // pointer exception. The fall-through projection of this CatchNode
4497             // will not be populated.
4498             Node* arg0 = call->in(TypeFunc::Parms);
4499             if (arg0->is_Type() &&
4500                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
4501               required_outcnt--;
4502             }
4503           } else if (call->entry_point() == OptoRuntime::new_array_Java() ||
4504                      call->entry_point() == OptoRuntime::new_array_nozero_Java()) {
4505             // Check for illegal array length. In such case, the optimizer has
4506             // detected that the allocation attempt will always result in an
4507             // exception. There is no fall-through projection of this CatchNode .
4508             assert(call->is_CallStaticJava(), "static call expected");
4509             assert(call->req() == call->jvms()->endoff() + 1, "missing extra input");
4510             uint valid_length_test_input = call->req() - 1;
4511             Node* valid_length_test = call->in(valid_length_test_input);
4512             call->del_req(valid_length_test_input);
4513             if (valid_length_test->find_int_con(1) == 0) {
4514               required_outcnt--;
4515             }
4516             dead_nodes.push(valid_length_test);
4517             assert(n->outcnt() == required_outcnt, "malformed control flow");
4518             continue;
4519           }
4520         }
4521       }
4522 
4523       // Recheck with a better notion of 'required_outcnt'
4524       if (n->outcnt() != required_outcnt) {
4525         DEBUG_ONLY( n->dump_bfs(1, 0, "-"); );
4526         assert(false, "malformed control flow");
4527         record_method_not_compilable("malformed control flow");
4528         return true;            // Not all targets reachable!
4529       }
4530     } else if (n->is_PCTable() && n->in(0) && n->in(0)->in(0) && n->in(0)->in(0)->is_Call()) {
4531       CallNode* call = n->in(0)->in(0)->as_Call();
4532       if (call->entry_point() == OptoRuntime::new_array_Java() ||
4533           call->entry_point() == OptoRuntime::new_array_nozero_Java()) {
4534         assert(call->is_CallStaticJava(), "static call expected");
4535         assert(call->req() == call->jvms()->endoff() + 1, "missing extra input");
4536         uint valid_length_test_input = call->req() - 1;
4537         dead_nodes.push(call->in(valid_length_test_input));
4538         call->del_req(valid_length_test_input); // valid length test useless now
4539       }
4540     }
4541     // Check that I actually visited all kids.  Unreached kids
4542     // must be infinite loops.
4543     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
4544       if (!frc._visited.test(n->fast_out(j)->_idx)) {
4545         record_method_not_compilable("infinite loop");
4546         return true;            // Found unvisited kid; must be unreach
4547       }
4548 
4549     // Here so verification code in final_graph_reshaping_walk()
4550     // always see an OuterStripMinedLoopEnd
4551     if (n->is_OuterStripMinedLoopEnd() || n->is_LongCountedLoopEnd()) {
4552       IfNode* init_iff = n->as_If();
4553       Node* iff = new IfNode(init_iff->in(0), init_iff->in(1), init_iff->_prob, init_iff->_fcnt);
4554       n->subsume_by(iff, this);
4555     }
4556   }
4557 
4558   while (dead_nodes.size() > 0) {
4559     Node* m = dead_nodes.pop();
4560     if (m->outcnt() == 0 && m != top()) {
4561       for (uint j = 0; j < m->req(); j++) {
4562         Node* in = m->in(j);
4563         if (in != nullptr) {
4564           dead_nodes.push(in);
4565         }
4566       }
4567       m->disconnect_inputs(this);
4568     }
4569   }
4570 
4571 #ifdef IA32
4572   // If original bytecodes contained a mixture of floats and doubles
4573   // check if the optimizer has made it homogeneous, item (3).
4574   if (UseSSE == 0 &&
4575       frc.get_float_count() > 32 &&
4576       frc.get_double_count() == 0 &&
4577       (10 * frc.get_call_count() < frc.get_float_count()) ) {
4578     set_24_bit_selection_and_mode(false, true);
4579   }
4580 #endif // IA32
4581 
4582   set_java_calls(frc.get_java_call_count());
4583   set_inner_loops(frc.get_inner_loop_count());
4584 
4585   // No infinite loops, no reason to bail out.
4586   return false;
4587 }
4588 
4589 //-----------------------------too_many_traps----------------------------------
4590 // Report if there are too many traps at the current method and bci.
4591 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
4592 bool Compile::too_many_traps(ciMethod* method,
4593                              int bci,
4594                              Deoptimization::DeoptReason reason) {
4595   ciMethodData* md = method->method_data();
4596   if (md->is_empty()) {
4597     // Assume the trap has not occurred, or that it occurred only
4598     // because of a transient condition during start-up in the interpreter.
4599     return false;
4600   }
4601   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : nullptr;
4602   if (md->has_trap_at(bci, m, reason) != 0) {
4603     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
4604     // Also, if there are multiple reasons, or if there is no per-BCI record,
4605     // assume the worst.
4606     if (log())
4607       log()->elem("observe trap='%s' count='%d'",
4608                   Deoptimization::trap_reason_name(reason),
4609                   md->trap_count(reason));
4610     return true;
4611   } else {
4612     // Ignore method/bci and see if there have been too many globally.
4613     return too_many_traps(reason, md);
4614   }
4615 }
4616 
4617 // Less-accurate variant which does not require a method and bci.
4618 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
4619                              ciMethodData* logmd) {
4620   if (trap_count(reason) >= Deoptimization::per_method_trap_limit(reason)) {
4621     // Too many traps globally.
4622     // Note that we use cumulative trap_count, not just md->trap_count.
4623     if (log()) {
4624       int mcount = (logmd == nullptr)? -1: (int)logmd->trap_count(reason);
4625       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
4626                   Deoptimization::trap_reason_name(reason),
4627                   mcount, trap_count(reason));
4628     }
4629     return true;
4630   } else {
4631     // The coast is clear.
4632     return false;
4633   }
4634 }
4635 
4636 //--------------------------too_many_recompiles--------------------------------
4637 // Report if there are too many recompiles at the current method and bci.
4638 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
4639 // Is not eager to return true, since this will cause the compiler to use
4640 // Action_none for a trap point, to avoid too many recompilations.
4641 bool Compile::too_many_recompiles(ciMethod* method,
4642                                   int bci,
4643                                   Deoptimization::DeoptReason reason) {
4644   ciMethodData* md = method->method_data();
4645   if (md->is_empty()) {
4646     // Assume the trap has not occurred, or that it occurred only
4647     // because of a transient condition during start-up in the interpreter.
4648     return false;
4649   }
4650   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
4651   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
4652   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
4653   Deoptimization::DeoptReason per_bc_reason
4654     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
4655   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : nullptr;
4656   if ((per_bc_reason == Deoptimization::Reason_none
4657        || md->has_trap_at(bci, m, reason) != 0)
4658       // The trap frequency measure we care about is the recompile count:
4659       && md->trap_recompiled_at(bci, m)
4660       && md->overflow_recompile_count() >= bc_cutoff) {
4661     // Do not emit a trap here if it has already caused recompilations.
4662     // Also, if there are multiple reasons, or if there is no per-BCI record,
4663     // assume the worst.
4664     if (log())
4665       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
4666                   Deoptimization::trap_reason_name(reason),
4667                   md->trap_count(reason),
4668                   md->overflow_recompile_count());
4669     return true;
4670   } else if (trap_count(reason) != 0
4671              && decompile_count() >= m_cutoff) {
4672     // Too many recompiles globally, and we have seen this sort of trap.
4673     // Use cumulative decompile_count, not just md->decompile_count.
4674     if (log())
4675       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
4676                   Deoptimization::trap_reason_name(reason),
4677                   md->trap_count(reason), trap_count(reason),
4678                   md->decompile_count(), decompile_count());
4679     return true;
4680   } else {
4681     // The coast is clear.
4682     return false;
4683   }
4684 }
4685 
4686 // Compute when not to trap. Used by matching trap based nodes and
4687 // NullCheck optimization.
4688 void Compile::set_allowed_deopt_reasons() {
4689   _allowed_reasons = 0;
4690   if (is_method_compilation()) {
4691     for (int rs = (int)Deoptimization::Reason_none+1; rs < Compile::trapHistLength; rs++) {
4692       assert(rs < BitsPerInt, "recode bit map");
4693       if (!too_many_traps((Deoptimization::DeoptReason) rs)) {
4694         _allowed_reasons |= nth_bit(rs);
4695       }
4696     }
4697   }
4698 }
4699 
4700 bool Compile::needs_clinit_barrier(ciMethod* method, ciMethod* accessing_method) {
4701   return method->is_static() && needs_clinit_barrier(method->holder(), accessing_method);
4702 }
4703 
4704 bool Compile::needs_clinit_barrier(ciField* field, ciMethod* accessing_method) {
4705   return field->is_static() && needs_clinit_barrier(field->holder(), accessing_method);
4706 }
4707 
4708 bool Compile::needs_clinit_barrier(ciInstanceKlass* holder, ciMethod* accessing_method) {
4709   if (holder->is_initialized()) {
4710     return false;
4711   }
4712   if (holder->is_being_initialized()) {
4713     if (accessing_method->holder() == holder) {
4714       // Access inside a class. The barrier can be elided when access happens in <clinit>,
4715       // <init>, or a static method. In all those cases, there was an initialization
4716       // barrier on the holder klass passed.
4717       if (accessing_method->is_class_initializer() ||
4718           accessing_method->is_object_constructor() ||
4719           accessing_method->is_static()) {
4720         return false;
4721       }
4722     } else if (accessing_method->holder()->is_subclass_of(holder)) {
4723       // Access from a subclass. The barrier can be elided only when access happens in <clinit>.
4724       // In case of <init> or a static method, the barrier is on the subclass is not enough:
4725       // child class can become fully initialized while its parent class is still being initialized.
4726       if (accessing_method->is_class_initializer()) {
4727         return false;
4728       }
4729     }
4730     ciMethod* root = method(); // the root method of compilation
4731     if (root != accessing_method) {
4732       return needs_clinit_barrier(holder, root); // check access in the context of compilation root
4733     }
4734   }
4735   return true;
4736 }
4737 
4738 #ifndef PRODUCT
4739 //------------------------------verify_bidirectional_edges---------------------
4740 // For each input edge to a node (ie - for each Use-Def edge), verify that
4741 // there is a corresponding Def-Use edge.
4742 void Compile::verify_bidirectional_edges(Unique_Node_List &visited) {
4743   // Allocate stack of size C->live_nodes()/16 to avoid frequent realloc
4744   uint stack_size = live_nodes() >> 4;
4745   Node_List nstack(MAX2(stack_size, (uint)OptoNodeListSize));
4746   nstack.push(_root);
4747 
4748   while (nstack.size() > 0) {
4749     Node* n = nstack.pop();
4750     if (visited.member(n)) {
4751       continue;
4752     }
4753     visited.push(n);
4754 
4755     // Walk over all input edges, checking for correspondence
4756     uint length = n->len();
4757     for (uint i = 0; i < length; i++) {
4758       Node* in = n->in(i);
4759       if (in != nullptr && !visited.member(in)) {
4760         nstack.push(in); // Put it on stack
4761       }
4762       if (in != nullptr && !in->is_top()) {
4763         // Count instances of `next`
4764         int cnt = 0;
4765         for (uint idx = 0; idx < in->_outcnt; idx++) {
4766           if (in->_out[idx] == n) {
4767             cnt++;
4768           }
4769         }
4770         assert(cnt > 0, "Failed to find Def-Use edge.");
4771         // Check for duplicate edges
4772         // walk the input array downcounting the input edges to n
4773         for (uint j = 0; j < length; j++) {
4774           if (n->in(j) == in) {
4775             cnt--;
4776           }
4777         }
4778         assert(cnt == 0, "Mismatched edge count.");
4779       } else if (in == nullptr) {
4780         assert(i == 0 || i >= n->req() ||
4781                n->is_Region() || n->is_Phi() || n->is_ArrayCopy() ||
4782                (n->is_Allocate() && i >= AllocateNode::InlineType) ||
4783                (n->is_Unlock() && i == (n->req() - 1)) ||
4784                (n->is_MemBar() && i == 5), // the precedence edge to a membar can be removed during macro node expansion
4785               "only region, phi, arraycopy, allocate, unlock or membar nodes have null data edges");
4786       } else {
4787         assert(in->is_top(), "sanity");
4788         // Nothing to check.
4789       }
4790     }
4791   }
4792 }
4793 
4794 //------------------------------verify_graph_edges---------------------------
4795 // Walk the Graph and verify that there is a one-to-one correspondence
4796 // between Use-Def edges and Def-Use edges in the graph.
4797 void Compile::verify_graph_edges(bool no_dead_code) {
4798   if (VerifyGraphEdges) {
4799     Unique_Node_List visited;
4800 
4801     // Call graph walk to check edges
4802     verify_bidirectional_edges(visited);
4803     if (no_dead_code) {
4804       // Now make sure that no visited node is used by an unvisited node.
4805       bool dead_nodes = false;
4806       Unique_Node_List checked;
4807       while (visited.size() > 0) {
4808         Node* n = visited.pop();
4809         checked.push(n);
4810         for (uint i = 0; i < n->outcnt(); i++) {
4811           Node* use = n->raw_out(i);
4812           if (checked.member(use))  continue;  // already checked
4813           if (visited.member(use))  continue;  // already in the graph
4814           if (use->is_Con())        continue;  // a dead ConNode is OK
4815           // At this point, we have found a dead node which is DU-reachable.
4816           if (!dead_nodes) {
4817             tty->print_cr("*** Dead nodes reachable via DU edges:");
4818             dead_nodes = true;
4819           }
4820           use->dump(2);
4821           tty->print_cr("---");
4822           checked.push(use);  // No repeats; pretend it is now checked.
4823         }
4824       }
4825       assert(!dead_nodes, "using nodes must be reachable from root");
4826     }
4827   }
4828 }
4829 #endif
4830 
4831 // The Compile object keeps track of failure reasons separately from the ciEnv.
4832 // This is required because there is not quite a 1-1 relation between the
4833 // ciEnv and its compilation task and the Compile object.  Note that one
4834 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
4835 // to backtrack and retry without subsuming loads.  Other than this backtracking
4836 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
4837 // by the logic in C2Compiler.
4838 void Compile::record_failure(const char* reason) {
4839   if (log() != nullptr) {
4840     log()->elem("failure reason='%s' phase='compile'", reason);
4841   }
4842   if (_failure_reason == nullptr) {
4843     // Record the first failure reason.
4844     _failure_reason = reason;
4845   }
4846 
4847   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
4848     C->print_method(PHASE_FAILURE, 1);
4849   }
4850   _root = nullptr;  // flush the graph, too
4851 }
4852 
4853 Compile::TracePhase::TracePhase(const char* name, elapsedTimer* accumulator)
4854   : TraceTime(name, accumulator, CITime, CITimeVerbose),
4855     _compile(nullptr), _log(nullptr), _phase_name(name), _dolog(CITimeVerbose)
4856 {
4857   if (_dolog) {
4858     _compile = Compile::current();
4859     _log = _compile->log();
4860   }
4861   if (_log != nullptr) {
4862     _log->begin_head("phase name='%s' nodes='%d' live='%d'", _phase_name, _compile->unique(), _compile->live_nodes());
4863     _log->stamp();
4864     _log->end_head();
4865   }
4866 }
4867 
4868 Compile::TracePhase::~TracePhase() {
4869 #ifdef ASSERT
4870   if (PrintIdealNodeCount) {
4871     tty->print_cr("phase name='%s' nodes='%d' live='%d' live_graph_walk='%d'",
4872                   _phase_name, _compile->unique(), _compile->live_nodes(), _compile->count_live_nodes_by_graph_walk());
4873   }
4874 
4875   if (VerifyIdealNodeCount) {
4876     Compile::current()->print_missing_nodes();
4877   }
4878 #endif
4879 
4880   if (_log != nullptr) {
4881     _log->done("phase name='%s' nodes='%d' live='%d'", _phase_name, _compile->unique(), _compile->live_nodes());
4882   }
4883 }
4884 
4885 //----------------------------static_subtype_check-----------------------------
4886 // Shortcut important common cases when superklass is exact:
4887 // (0) superklass is java.lang.Object (can occur in reflective code)
4888 // (1) subklass is already limited to a subtype of superklass => always ok
4889 // (2) subklass does not overlap with superklass => always fail
4890 // (3) superklass has NO subtypes and we can check with a simple compare.
4891 Compile::SubTypeCheckResult Compile::static_subtype_check(const TypeKlassPtr* superk, const TypeKlassPtr* subk, bool skip) {
4892   if (skip) {
4893     return SSC_full_test;       // Let caller generate the general case.
4894   }
4895 
4896   if (subk->is_java_subtype_of(superk)) {
4897     return SSC_always_true; // (0) and (1)  this test cannot fail
4898   }
4899 
4900   if (!subk->maybe_java_subtype_of(superk)) {
4901     return SSC_always_false; // (2) true path dead; no dynamic test needed
4902   }
4903 
4904   const Type* superelem = superk;
4905   if (superk->isa_aryklassptr()) {
4906     int ignored;
4907     superelem = superk->is_aryklassptr()->base_element_type(ignored);
4908 
4909     // Do not fold the subtype check to an array klass pointer comparison for [V? arrays.
4910     // [QMyValue is a subtype of [LMyValue but the klass for [QMyValue is not equal to
4911     // the klass for [LMyValue. Perform a full test.
4912     if (!superk->is_aryklassptr()->is_null_free() && superk->is_aryklassptr()->elem()->isa_instklassptr() &&
4913         superk->is_aryklassptr()->elem()->is_instklassptr()->instance_klass()->is_inlinetype()) {
4914       return SSC_full_test;
4915     }
4916   }
4917 
4918   if (superelem->isa_instklassptr()) {
4919     ciInstanceKlass* ik = superelem->is_instklassptr()->instance_klass();
4920     if (!ik->has_subklass()) {
4921       if (!ik->is_final()) {
4922         // Add a dependency if there is a chance of a later subclass.
4923         dependencies()->assert_leaf_type(ik);
4924       }
4925       if (!superk->maybe_java_subtype_of(subk)) {
4926         return SSC_always_false;
4927       }
4928       return SSC_easy_test;     // (3) caller can do a simple ptr comparison
4929     }
4930   } else {
4931     // A primitive array type has no subtypes.
4932     return SSC_easy_test;       // (3) caller can do a simple ptr comparison
4933   }
4934 
4935   return SSC_full_test;
4936 }
4937 
4938 Node* Compile::conv_I2X_index(PhaseGVN* phase, Node* idx, const TypeInt* sizetype, Node* ctrl) {
4939 #ifdef _LP64
4940   // The scaled index operand to AddP must be a clean 64-bit value.
4941   // Java allows a 32-bit int to be incremented to a negative
4942   // value, which appears in a 64-bit register as a large
4943   // positive number.  Using that large positive number as an
4944   // operand in pointer arithmetic has bad consequences.
4945   // On the other hand, 32-bit overflow is rare, and the possibility
4946   // can often be excluded, if we annotate the ConvI2L node with
4947   // a type assertion that its value is known to be a small positive
4948   // number.  (The prior range check has ensured this.)
4949   // This assertion is used by ConvI2LNode::Ideal.
4950   int index_max = max_jint - 1;  // array size is max_jint, index is one less
4951   if (sizetype != nullptr) index_max = sizetype->_hi - 1;
4952   const TypeInt* iidxtype = TypeInt::make(0, index_max, Type::WidenMax);
4953   idx = constrained_convI2L(phase, idx, iidxtype, ctrl);
4954 #endif
4955   return idx;
4956 }
4957 
4958 // Convert integer value to a narrowed long type dependent on ctrl (for example, a range check)
4959 Node* Compile::constrained_convI2L(PhaseGVN* phase, Node* value, const TypeInt* itype, Node* ctrl, bool carry_dependency) {
4960   if (ctrl != nullptr) {
4961     // Express control dependency by a CastII node with a narrow type.
4962     value = new CastIINode(value, itype, carry_dependency ? ConstraintCastNode::StrongDependency : ConstraintCastNode::RegularDependency, true /* range check dependency */);
4963     // Make the CastII node dependent on the control input to prevent the narrowed ConvI2L
4964     // node from floating above the range check during loop optimizations. Otherwise, the
4965     // ConvI2L node may be eliminated independently of the range check, causing the data path
4966     // to become TOP while the control path is still there (although it's unreachable).
4967     value->set_req(0, ctrl);
4968     value = phase->transform(value);
4969   }
4970   const TypeLong* ltype = TypeLong::make(itype->_lo, itype->_hi, itype->_widen);
4971   return phase->transform(new ConvI2LNode(value, ltype));
4972 }
4973 
4974 // The message about the current inlining is accumulated in
4975 // _print_inlining_stream and transferred into the _print_inlining_list
4976 // once we know whether inlining succeeds or not. For regular
4977 // inlining, messages are appended to the buffer pointed by
4978 // _print_inlining_idx in the _print_inlining_list. For late inlining,
4979 // a new buffer is added after _print_inlining_idx in the list. This
4980 // way we can update the inlining message for late inlining call site
4981 // when the inlining is attempted again.
4982 void Compile::print_inlining_init() {
4983   if (print_inlining() || print_intrinsics()) {
4984     // print_inlining_init is actually called several times.
4985     print_inlining_reset();
4986     _print_inlining_list = new (comp_arena())GrowableArray<PrintInliningBuffer*>(comp_arena(), 1, 1, new PrintInliningBuffer());
4987   }
4988 }
4989 
4990 void Compile::print_inlining_reinit() {
4991   if (print_inlining() || print_intrinsics()) {
4992     print_inlining_reset();
4993   }
4994 }
4995 
4996 void Compile::print_inlining_reset() {
4997   _print_inlining_stream->reset();
4998 }
4999 
5000 void Compile::print_inlining_commit() {
5001   assert(print_inlining() || print_intrinsics(), "PrintInlining off?");
5002   // Transfer the message from _print_inlining_stream to the current
5003   // _print_inlining_list buffer and clear _print_inlining_stream.
5004   _print_inlining_list->at(_print_inlining_idx)->ss()->write(_print_inlining_stream->base(), _print_inlining_stream->size());
5005   print_inlining_reset();
5006 }
5007 
5008 void Compile::print_inlining_push() {
5009   // Add new buffer to the _print_inlining_list at current position
5010   _print_inlining_idx++;
5011   _print_inlining_list->insert_before(_print_inlining_idx, new PrintInliningBuffer());
5012 }
5013 
5014 Compile::PrintInliningBuffer* Compile::print_inlining_current() {
5015   return _print_inlining_list->at(_print_inlining_idx);
5016 }
5017 
5018 void Compile::print_inlining_update(CallGenerator* cg) {
5019   if (print_inlining() || print_intrinsics()) {
5020     if (cg->is_late_inline()) {
5021       if (print_inlining_current()->cg() != cg &&
5022           (print_inlining_current()->cg() != nullptr ||
5023            print_inlining_current()->ss()->size() != 0)) {
5024         print_inlining_push();
5025       }
5026       print_inlining_commit();
5027       print_inlining_current()->set_cg(cg);
5028     } else {
5029       if (print_inlining_current()->cg() != nullptr) {
5030         print_inlining_push();
5031       }
5032       print_inlining_commit();
5033     }
5034   }
5035 }
5036 
5037 void Compile::print_inlining_move_to(CallGenerator* cg) {
5038   // We resume inlining at a late inlining call site. Locate the
5039   // corresponding inlining buffer so that we can update it.
5040   if (print_inlining() || print_intrinsics()) {
5041     for (int i = 0; i < _print_inlining_list->length(); i++) {
5042       if (_print_inlining_list->at(i)->cg() == cg) {
5043         _print_inlining_idx = i;
5044         return;
5045       }
5046     }
5047     ShouldNotReachHere();
5048   }
5049 }
5050 
5051 void Compile::print_inlining_update_delayed(CallGenerator* cg) {
5052   if (print_inlining() || print_intrinsics()) {
5053     assert(_print_inlining_stream->size() > 0, "missing inlining msg");
5054     assert(print_inlining_current()->cg() == cg, "wrong entry");
5055     // replace message with new message
5056     _print_inlining_list->at_put(_print_inlining_idx, new PrintInliningBuffer());
5057     print_inlining_commit();
5058     print_inlining_current()->set_cg(cg);
5059   }
5060 }
5061 
5062 void Compile::print_inlining_assert_ready() {
5063   assert(!_print_inlining || _print_inlining_stream->size() == 0, "losing data");
5064 }
5065 
5066 void Compile::process_print_inlining() {
5067   assert(_late_inlines.length() == 0, "not drained yet");
5068   if (print_inlining() || print_intrinsics()) {
5069     ResourceMark rm;
5070     stringStream ss;
5071     assert(_print_inlining_list != nullptr, "process_print_inlining should be called only once.");
5072     for (int i = 0; i < _print_inlining_list->length(); i++) {
5073       PrintInliningBuffer* pib = _print_inlining_list->at(i);
5074       ss.print("%s", pib->ss()->freeze());
5075       delete pib;
5076       DEBUG_ONLY(_print_inlining_list->at_put(i, nullptr));
5077     }
5078     // Reset _print_inlining_list, it only contains destructed objects.
5079     // It is on the arena, so it will be freed when the arena is reset.
5080     _print_inlining_list = nullptr;
5081     // _print_inlining_stream won't be used anymore, either.
5082     print_inlining_reset();
5083     size_t end = ss.size();
5084     _print_inlining_output = NEW_ARENA_ARRAY(comp_arena(), char, end+1);
5085     strncpy(_print_inlining_output, ss.freeze(), end+1);
5086     _print_inlining_output[end] = 0;
5087   }
5088 }
5089 
5090 void Compile::dump_print_inlining() {
5091   if (_print_inlining_output != nullptr) {
5092     tty->print_raw(_print_inlining_output);
5093   }
5094 }
5095 
5096 void Compile::log_late_inline(CallGenerator* cg) {
5097   if (log() != nullptr) {
5098     log()->head("late_inline method='%d'  inline_id='" JLONG_FORMAT "'", log()->identify(cg->method()),
5099                 cg->unique_id());
5100     JVMState* p = cg->call_node()->jvms();
5101     while (p != nullptr) {
5102       log()->elem("jvms bci='%d' method='%d'", p->bci(), log()->identify(p->method()));
5103       p = p->caller();
5104     }
5105     log()->tail("late_inline");
5106   }
5107 }
5108 
5109 void Compile::log_late_inline_failure(CallGenerator* cg, const char* msg) {
5110   log_late_inline(cg);
5111   if (log() != nullptr) {
5112     log()->inline_fail(msg);
5113   }
5114 }
5115 
5116 void Compile::log_inline_id(CallGenerator* cg) {
5117   if (log() != nullptr) {
5118     // The LogCompilation tool needs a unique way to identify late
5119     // inline call sites. This id must be unique for this call site in
5120     // this compilation. Try to have it unique across compilations as
5121     // well because it can be convenient when grepping through the log
5122     // file.
5123     // Distinguish OSR compilations from others in case CICountOSR is
5124     // on.
5125     jlong id = ((jlong)unique()) + (((jlong)compile_id()) << 33) + (CICountOSR && is_osr_compilation() ? ((jlong)1) << 32 : 0);
5126     cg->set_unique_id(id);
5127     log()->elem("inline_id id='" JLONG_FORMAT "'", id);
5128   }
5129 }
5130 
5131 void Compile::log_inline_failure(const char* msg) {
5132   if (C->log() != nullptr) {
5133     C->log()->inline_fail(msg);
5134   }
5135 }
5136 
5137 
5138 // Dump inlining replay data to the stream.
5139 // Don't change thread state and acquire any locks.
5140 void Compile::dump_inline_data(outputStream* out) {
5141   InlineTree* inl_tree = ilt();
5142   if (inl_tree != nullptr) {
5143     out->print(" inline %d", inl_tree->count());
5144     inl_tree->dump_replay_data(out);
5145   }
5146 }
5147 
5148 void Compile::dump_inline_data_reduced(outputStream* out) {
5149   assert(ReplayReduce, "");
5150 
5151   InlineTree* inl_tree = ilt();
5152   if (inl_tree == nullptr) {
5153     return;
5154   }
5155   // Enable iterative replay file reduction
5156   // Output "compile" lines for depth 1 subtrees,
5157   // simulating that those trees were compiled
5158   // instead of inlined.
5159   for (int i = 0; i < inl_tree->subtrees().length(); ++i) {
5160     InlineTree* sub = inl_tree->subtrees().at(i);
5161     if (sub->inline_level() != 1) {
5162       continue;
5163     }
5164 
5165     ciMethod* method = sub->method();
5166     int entry_bci = -1;
5167     int comp_level = env()->task()->comp_level();
5168     out->print("compile ");
5169     method->dump_name_as_ascii(out);
5170     out->print(" %d %d", entry_bci, comp_level);
5171     out->print(" inline %d", sub->count());
5172     sub->dump_replay_data(out, -1);
5173     out->cr();
5174   }
5175 }
5176 
5177 int Compile::cmp_expensive_nodes(Node* n1, Node* n2) {
5178   if (n1->Opcode() < n2->Opcode())      return -1;
5179   else if (n1->Opcode() > n2->Opcode()) return 1;
5180 
5181   assert(n1->req() == n2->req(), "can't compare %s nodes: n1->req() = %d, n2->req() = %d", NodeClassNames[n1->Opcode()], n1->req(), n2->req());
5182   for (uint i = 1; i < n1->req(); i++) {
5183     if (n1->in(i) < n2->in(i))      return -1;
5184     else if (n1->in(i) > n2->in(i)) return 1;
5185   }
5186 
5187   return 0;
5188 }
5189 
5190 int Compile::cmp_expensive_nodes(Node** n1p, Node** n2p) {
5191   Node* n1 = *n1p;
5192   Node* n2 = *n2p;
5193 
5194   return cmp_expensive_nodes(n1, n2);
5195 }
5196 
5197 void Compile::sort_expensive_nodes() {
5198   if (!expensive_nodes_sorted()) {
5199     _expensive_nodes.sort(cmp_expensive_nodes);
5200   }
5201 }
5202 
5203 bool Compile::expensive_nodes_sorted() const {
5204   for (int i = 1; i < _expensive_nodes.length(); i++) {
5205     if (cmp_expensive_nodes(_expensive_nodes.adr_at(i), _expensive_nodes.adr_at(i-1)) < 0) {
5206       return false;
5207     }
5208   }
5209   return true;
5210 }
5211 
5212 bool Compile::should_optimize_expensive_nodes(PhaseIterGVN &igvn) {
5213   if (_expensive_nodes.length() == 0) {
5214     return false;
5215   }
5216 
5217   assert(OptimizeExpensiveOps, "optimization off?");
5218 
5219   // Take this opportunity to remove dead nodes from the list
5220   int j = 0;
5221   for (int i = 0; i < _expensive_nodes.length(); i++) {
5222     Node* n = _expensive_nodes.at(i);
5223     if (!n->is_unreachable(igvn)) {
5224       assert(n->is_expensive(), "should be expensive");
5225       _expensive_nodes.at_put(j, n);
5226       j++;
5227     }
5228   }
5229   _expensive_nodes.trunc_to(j);
5230 
5231   // Then sort the list so that similar nodes are next to each other
5232   // and check for at least two nodes of identical kind with same data
5233   // inputs.
5234   sort_expensive_nodes();
5235 
5236   for (int i = 0; i < _expensive_nodes.length()-1; i++) {
5237     if (cmp_expensive_nodes(_expensive_nodes.adr_at(i), _expensive_nodes.adr_at(i+1)) == 0) {
5238       return true;
5239     }
5240   }
5241 
5242   return false;
5243 }
5244 
5245 void Compile::cleanup_expensive_nodes(PhaseIterGVN &igvn) {
5246   if (_expensive_nodes.length() == 0) {
5247     return;
5248   }
5249 
5250   assert(OptimizeExpensiveOps, "optimization off?");
5251 
5252   // Sort to bring similar nodes next to each other and clear the
5253   // control input of nodes for which there's only a single copy.
5254   sort_expensive_nodes();
5255 
5256   int j = 0;
5257   int identical = 0;
5258   int i = 0;
5259   bool modified = false;
5260   for (; i < _expensive_nodes.length()-1; i++) {
5261     assert(j <= i, "can't write beyond current index");
5262     if (_expensive_nodes.at(i)->Opcode() == _expensive_nodes.at(i+1)->Opcode()) {
5263       identical++;
5264       _expensive_nodes.at_put(j++, _expensive_nodes.at(i));
5265       continue;
5266     }
5267     if (identical > 0) {
5268       _expensive_nodes.at_put(j++, _expensive_nodes.at(i));
5269       identical = 0;
5270     } else {
5271       Node* n = _expensive_nodes.at(i);
5272       igvn.replace_input_of(n, 0, nullptr);
5273       igvn.hash_insert(n);
5274       modified = true;
5275     }
5276   }
5277   if (identical > 0) {
5278     _expensive_nodes.at_put(j++, _expensive_nodes.at(i));
5279   } else if (_expensive_nodes.length() >= 1) {
5280     Node* n = _expensive_nodes.at(i);
5281     igvn.replace_input_of(n, 0, nullptr);
5282     igvn.hash_insert(n);
5283     modified = true;
5284   }
5285   _expensive_nodes.trunc_to(j);
5286   if (modified) {
5287     igvn.optimize();
5288   }
5289 }
5290 
5291 void Compile::add_expensive_node(Node * n) {
5292   assert(!_expensive_nodes.contains(n), "duplicate entry in expensive list");
5293   assert(n->is_expensive(), "expensive nodes with non-null control here only");
5294   assert(!n->is_CFG() && !n->is_Mem(), "no cfg or memory nodes here");
5295   if (OptimizeExpensiveOps) {
5296     _expensive_nodes.append(n);
5297   } else {
5298     // Clear control input and let IGVN optimize expensive nodes if
5299     // OptimizeExpensiveOps is off.
5300     n->set_req(0, nullptr);
5301   }
5302 }
5303 
5304 /**
5305  * Track coarsened Lock and Unlock nodes.
5306  */
5307 
5308 class Lock_List : public Node_List {
5309   uint _origin_cnt;
5310 public:
5311   Lock_List(Arena *a, uint cnt) : Node_List(a), _origin_cnt(cnt) {}
5312   uint origin_cnt() const { return _origin_cnt; }
5313 };
5314 
5315 void Compile::add_coarsened_locks(GrowableArray<AbstractLockNode*>& locks) {
5316   int length = locks.length();
5317   if (length > 0) {
5318     // Have to keep this list until locks elimination during Macro nodes elimination.
5319     Lock_List* locks_list = new (comp_arena()) Lock_List(comp_arena(), length);
5320     for (int i = 0; i < length; i++) {
5321       AbstractLockNode* lock = locks.at(i);
5322       assert(lock->is_coarsened(), "expecting only coarsened AbstractLock nodes, but got '%s'[%d] node", lock->Name(), lock->_idx);
5323       locks_list->push(lock);
5324     }
5325     _coarsened_locks.append(locks_list);
5326   }
5327 }
5328 
5329 void Compile::remove_useless_coarsened_locks(Unique_Node_List& useful) {
5330   int count = coarsened_count();
5331   for (int i = 0; i < count; i++) {
5332     Node_List* locks_list = _coarsened_locks.at(i);
5333     for (uint j = 0; j < locks_list->size(); j++) {
5334       Node* lock = locks_list->at(j);
5335       assert(lock->is_AbstractLock(), "sanity");
5336       if (!useful.member(lock)) {
5337         locks_list->yank(lock);
5338       }
5339     }
5340   }
5341 }
5342 
5343 void Compile::remove_coarsened_lock(Node* n) {
5344   if (n->is_AbstractLock()) {
5345     int count = coarsened_count();
5346     for (int i = 0; i < count; i++) {
5347       Node_List* locks_list = _coarsened_locks.at(i);
5348       locks_list->yank(n);
5349     }
5350   }
5351 }
5352 
5353 bool Compile::coarsened_locks_consistent() {
5354   int count = coarsened_count();
5355   for (int i = 0; i < count; i++) {
5356     bool unbalanced = false;
5357     bool modified = false; // track locks kind modifications
5358     Lock_List* locks_list = (Lock_List*)_coarsened_locks.at(i);
5359     uint size = locks_list->size();
5360     if (size == 0) {
5361       unbalanced = false; // All locks were eliminated - good
5362     } else if (size != locks_list->origin_cnt()) {
5363       unbalanced = true; // Some locks were removed from list
5364     } else {
5365       for (uint j = 0; j < size; j++) {
5366         Node* lock = locks_list->at(j);
5367         // All nodes in group should have the same state (modified or not)
5368         if (!lock->as_AbstractLock()->is_coarsened()) {
5369           if (j == 0) {
5370             // first on list was modified, the rest should be too for consistency
5371             modified = true;
5372           } else if (!modified) {
5373             // this lock was modified but previous locks on the list were not
5374             unbalanced = true;
5375             break;
5376           }
5377         } else if (modified) {
5378           // previous locks on list were modified but not this lock
5379           unbalanced = true;
5380           break;
5381         }
5382       }
5383     }
5384     if (unbalanced) {
5385       // unbalanced monitor enter/exit - only some [un]lock nodes were removed or modified
5386 #ifdef ASSERT
5387       if (PrintEliminateLocks) {
5388         tty->print_cr("=== unbalanced coarsened locks ===");
5389         for (uint l = 0; l < size; l++) {
5390           locks_list->at(l)->dump();
5391         }
5392       }
5393 #endif
5394       record_failure(C2Compiler::retry_no_locks_coarsening());
5395       return false;
5396     }
5397   }
5398   return true;
5399 }
5400 
5401 /**
5402  * Remove the speculative part of types and clean up the graph
5403  */
5404 void Compile::remove_speculative_types(PhaseIterGVN &igvn) {
5405   if (UseTypeSpeculation) {
5406     Unique_Node_List worklist;
5407     worklist.push(root());
5408     int modified = 0;
5409     // Go over all type nodes that carry a speculative type, drop the
5410     // speculative part of the type and enqueue the node for an igvn
5411     // which may optimize it out.
5412     for (uint next = 0; next < worklist.size(); ++next) {
5413       Node *n  = worklist.at(next);
5414       if (n->is_Type()) {
5415         TypeNode* tn = n->as_Type();
5416         const Type* t = tn->type();
5417         const Type* t_no_spec = t->remove_speculative();
5418         if (t_no_spec != t) {
5419           bool in_hash = igvn.hash_delete(n);
5420           assert(in_hash, "node should be in igvn hash table");
5421           tn->set_type(t_no_spec);
5422           igvn.hash_insert(n);
5423           igvn._worklist.push(n); // give it a chance to go away
5424           modified++;
5425         }
5426       }
5427       // Iterate over outs - endless loops is unreachable from below
5428       for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
5429         Node *m = n->fast_out(i);
5430         if (not_a_node(m)) {
5431           continue;
5432         }
5433         worklist.push(m);
5434       }
5435     }
5436     // Drop the speculative part of all types in the igvn's type table
5437     igvn.remove_speculative_types();
5438     if (modified > 0) {
5439       igvn.optimize();
5440     }
5441 #ifdef ASSERT
5442     // Verify that after the IGVN is over no speculative type has resurfaced
5443     worklist.clear();
5444     worklist.push(root());
5445     for (uint next = 0; next < worklist.size(); ++next) {
5446       Node *n  = worklist.at(next);
5447       const Type* t = igvn.type_or_null(n);
5448       assert((t == nullptr) || (t == t->remove_speculative()), "no more speculative types");
5449       if (n->is_Type()) {
5450         t = n->as_Type()->type();
5451         assert(t == t->remove_speculative(), "no more speculative types");
5452       }
5453       // Iterate over outs - endless loops is unreachable from below
5454       for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
5455         Node *m = n->fast_out(i);
5456         if (not_a_node(m)) {
5457           continue;
5458         }
5459         worklist.push(m);
5460       }
5461     }
5462     igvn.check_no_speculative_types();
5463 #endif
5464   }
5465 }
5466 
5467 Node* Compile::optimize_acmp(PhaseGVN* phase, Node* a, Node* b) {
5468   const TypeInstPtr* ta = phase->type(a)->isa_instptr();
5469   const TypeInstPtr* tb = phase->type(b)->isa_instptr();
5470   if (!EnableValhalla || ta == nullptr || tb == nullptr ||
5471       ta->is_zero_type() || tb->is_zero_type() ||
5472       !ta->can_be_inline_type() || !tb->can_be_inline_type()) {
5473     // Use old acmp if one operand is null or not an inline type
5474     return new CmpPNode(a, b);
5475   } else if (ta->is_inlinetypeptr() || tb->is_inlinetypeptr()) {
5476     // We know that one operand is an inline type. Therefore,
5477     // new acmp will only return true if both operands are nullptr.
5478     // Check if both operands are null by or'ing the oops.
5479     a = phase->transform(new CastP2XNode(nullptr, a));
5480     b = phase->transform(new CastP2XNode(nullptr, b));
5481     a = phase->transform(new OrXNode(a, b));
5482     return new CmpXNode(a, phase->MakeConX(0));
5483   }
5484   // Use new acmp
5485   return nullptr;
5486 }
5487 
5488 // Auxiliary methods to support randomized stressing/fuzzing.
5489 
5490 int Compile::random() {
5491   _stress_seed = os::next_random(_stress_seed);
5492   return static_cast<int>(_stress_seed);
5493 }
5494 
5495 // This method can be called the arbitrary number of times, with current count
5496 // as the argument. The logic allows selecting a single candidate from the
5497 // running list of candidates as follows:
5498 //    int count = 0;
5499 //    Cand* selected = null;
5500 //    while(cand = cand->next()) {
5501 //      if (randomized_select(++count)) {
5502 //        selected = cand;
5503 //      }
5504 //    }
5505 //
5506 // Including count equalizes the chances any candidate is "selected".
5507 // This is useful when we don't have the complete list of candidates to choose
5508 // from uniformly. In this case, we need to adjust the randomicity of the
5509 // selection, or else we will end up biasing the selection towards the latter
5510 // candidates.
5511 //
5512 // Quick back-envelope calculation shows that for the list of n candidates
5513 // the equal probability for the candidate to persist as "best" can be
5514 // achieved by replacing it with "next" k-th candidate with the probability
5515 // of 1/k. It can be easily shown that by the end of the run, the
5516 // probability for any candidate is converged to 1/n, thus giving the
5517 // uniform distribution among all the candidates.
5518 //
5519 // We don't care about the domain size as long as (RANDOMIZED_DOMAIN / count) is large.
5520 #define RANDOMIZED_DOMAIN_POW 29
5521 #define RANDOMIZED_DOMAIN (1 << RANDOMIZED_DOMAIN_POW)
5522 #define RANDOMIZED_DOMAIN_MASK ((1 << (RANDOMIZED_DOMAIN_POW + 1)) - 1)
5523 bool Compile::randomized_select(int count) {
5524   assert(count > 0, "only positive");
5525   return (random() & RANDOMIZED_DOMAIN_MASK) < (RANDOMIZED_DOMAIN / count);
5526 }
5527 
5528 CloneMap&     Compile::clone_map()                 { return _clone_map; }
5529 void          Compile::set_clone_map(Dict* d)      { _clone_map._dict = d; }
5530 
5531 void NodeCloneInfo::dump_on(outputStream* st) const {
5532   st->print(" {%d:%d} ", idx(), gen());
5533 }
5534 
5535 void CloneMap::clone(Node* old, Node* nnn, int gen) {
5536   uint64_t val = value(old->_idx);
5537   NodeCloneInfo cio(val);
5538   assert(val != 0, "old node should be in the map");
5539   NodeCloneInfo cin(cio.idx(), gen + cio.gen());
5540   insert(nnn->_idx, cin.get());
5541 #ifndef PRODUCT
5542   if (is_debug()) {
5543     tty->print_cr("CloneMap::clone inserted node %d info {%d:%d} into CloneMap", nnn->_idx, cin.idx(), cin.gen());
5544   }
5545 #endif
5546 }
5547 
5548 void CloneMap::verify_insert_and_clone(Node* old, Node* nnn, int gen) {
5549   NodeCloneInfo cio(value(old->_idx));
5550   if (cio.get() == 0) {
5551     cio.set(old->_idx, 0);
5552     insert(old->_idx, cio.get());
5553 #ifndef PRODUCT
5554     if (is_debug()) {
5555       tty->print_cr("CloneMap::verify_insert_and_clone inserted node %d info {%d:%d} into CloneMap", old->_idx, cio.idx(), cio.gen());
5556     }
5557 #endif
5558   }
5559   clone(old, nnn, gen);
5560 }
5561 
5562 int CloneMap::max_gen() const {
5563   int g = 0;
5564   DictI di(_dict);
5565   for(; di.test(); ++di) {
5566     int t = gen(di._key);
5567     if (g < t) {
5568       g = t;
5569 #ifndef PRODUCT
5570       if (is_debug()) {
5571         tty->print_cr("CloneMap::max_gen() update max=%d from %d", g, _2_node_idx_t(di._key));
5572       }
5573 #endif
5574     }
5575   }
5576   return g;
5577 }
5578 
5579 void CloneMap::dump(node_idx_t key, outputStream* st) const {
5580   uint64_t val = value(key);
5581   if (val != 0) {
5582     NodeCloneInfo ni(val);
5583     ni.dump_on(st);
5584   }
5585 }
5586 
5587 // Move Allocate nodes to the start of the list
5588 void Compile::sort_macro_nodes() {
5589   int count = macro_count();
5590   int allocates = 0;
5591   for (int i = 0; i < count; i++) {
5592     Node* n = macro_node(i);
5593     if (n->is_Allocate()) {
5594       if (i != allocates) {
5595         Node* tmp = macro_node(allocates);
5596         _macro_nodes.at_put(allocates, n);
5597         _macro_nodes.at_put(i, tmp);
5598       }
5599       allocates++;
5600     }
5601   }
5602 }
5603 
5604 void Compile::print_method(CompilerPhaseType cpt, int level, Node* n) {
5605   EventCompilerPhase event;
5606   if (event.should_commit()) {
5607     CompilerEvent::PhaseEvent::post(event, C->_latest_stage_start_counter, cpt, C->_compile_id, level);
5608   }
5609 #ifndef PRODUCT
5610   ResourceMark rm;
5611   stringStream ss;
5612   ss.print_raw(CompilerPhaseTypeHelper::to_description(cpt));
5613   if (n != nullptr) {
5614     ss.print(": %d %s ", n->_idx, NodeClassNames[n->Opcode()]);
5615   }
5616 
5617   const char* name = ss.as_string();
5618   if (should_print_igv(level)) {
5619     _igv_printer->print_method(name, level);
5620   }
5621   if (should_print_phase(cpt)) {
5622     print_ideal_ir(CompilerPhaseTypeHelper::to_name(cpt));
5623   }
5624 #endif
5625   C->_latest_stage_start_counter.stamp();
5626 }
5627 
5628 // Only used from CompileWrapper
5629 void Compile::begin_method() {
5630 #ifndef PRODUCT
5631   if (_method != nullptr && should_print_igv(1)) {
5632     _igv_printer->begin_method();
5633   }
5634 #endif
5635   C->_latest_stage_start_counter.stamp();
5636 }
5637 
5638 // Only used from CompileWrapper
5639 void Compile::end_method() {
5640   EventCompilerPhase event;
5641   if (event.should_commit()) {
5642     CompilerEvent::PhaseEvent::post(event, C->_latest_stage_start_counter, PHASE_END, C->_compile_id, 1);
5643   }
5644 
5645 #ifndef PRODUCT
5646   if (_method != nullptr && should_print_igv(1)) {
5647     _igv_printer->end_method();
5648   }
5649 #endif
5650 }
5651 
5652 bool Compile::should_print_phase(CompilerPhaseType cpt) {
5653 #ifndef PRODUCT
5654   if ((_directive->ideal_phase_mask() & CompilerPhaseTypeHelper::to_bitmask(cpt)) != 0) {
5655     return true;
5656   }
5657 #endif
5658   return false;
5659 }
5660 
5661 bool Compile::should_print_igv(int level) {
5662 #ifndef PRODUCT
5663   if (PrintIdealGraphLevel < 0) { // disabled by the user
5664     return false;
5665   }
5666 
5667   bool need = directive()->IGVPrintLevelOption >= level;
5668   if (need && !_igv_printer) {
5669     _igv_printer = IdealGraphPrinter::printer();
5670     _igv_printer->set_compile(this);
5671   }
5672   return need;
5673 #else
5674   return false;
5675 #endif
5676 }
5677 
5678 #ifndef PRODUCT
5679 IdealGraphPrinter* Compile::_debug_file_printer = nullptr;
5680 IdealGraphPrinter* Compile::_debug_network_printer = nullptr;
5681 
5682 // Called from debugger. Prints method to the default file with the default phase name.
5683 // This works regardless of any Ideal Graph Visualizer flags set or not.
5684 void igv_print() {
5685   Compile::current()->igv_print_method_to_file();
5686 }
5687 
5688 // Same as igv_print() above but with a specified phase name.
5689 void igv_print(const char* phase_name) {
5690   Compile::current()->igv_print_method_to_file(phase_name);
5691 }
5692 
5693 // Called from debugger. Prints method with the default phase name to the default network or the one specified with
5694 // the network flags for the Ideal Graph Visualizer, or to the default file depending on the 'network' argument.
5695 // This works regardless of any Ideal Graph Visualizer flags set or not.
5696 void igv_print(bool network) {
5697   if (network) {
5698     Compile::current()->igv_print_method_to_network();
5699   } else {
5700     Compile::current()->igv_print_method_to_file();
5701   }
5702 }
5703 
5704 // Same as igv_print(bool network) above but with a specified phase name.
5705 void igv_print(bool network, const char* phase_name) {
5706   if (network) {
5707     Compile::current()->igv_print_method_to_network(phase_name);
5708   } else {
5709     Compile::current()->igv_print_method_to_file(phase_name);
5710   }
5711 }
5712 
5713 // Called from debugger. Normal write to the default _printer. Only works if Ideal Graph Visualizer printing flags are set.
5714 void igv_print_default() {
5715   Compile::current()->print_method(PHASE_DEBUG, 0);
5716 }
5717 
5718 // Called from debugger, especially when replaying a trace in which the program state cannot be altered like with rr replay.
5719 // A method is appended to an existing default file with the default phase name. This means that igv_append() must follow
5720 // an earlier igv_print(*) call which sets up the file. This works regardless of any Ideal Graph Visualizer flags set or not.
5721 void igv_append() {
5722   Compile::current()->igv_print_method_to_file("Debug", true);
5723 }
5724 
5725 // Same as igv_append() above but with a specified phase name.
5726 void igv_append(const char* phase_name) {
5727   Compile::current()->igv_print_method_to_file(phase_name, true);
5728 }
5729 
5730 void Compile::igv_print_method_to_file(const char* phase_name, bool append) {
5731   const char* file_name = "custom_debug.xml";
5732   if (_debug_file_printer == nullptr) {
5733     _debug_file_printer = new IdealGraphPrinter(C, file_name, append);
5734   } else {
5735     _debug_file_printer->update_compiled_method(C->method());
5736   }
5737   tty->print_cr("Method %s to %s", append ? "appended" : "printed", file_name);
5738   _debug_file_printer->print(phase_name, (Node*)C->root());
5739 }
5740 
5741 void Compile::igv_print_method_to_network(const char* phase_name) {
5742   if (_debug_network_printer == nullptr) {
5743     _debug_network_printer = new IdealGraphPrinter(C);
5744   } else {
5745     _debug_network_printer->update_compiled_method(C->method());
5746   }
5747   tty->print_cr("Method printed over network stream to IGV");
5748   _debug_network_printer->print(phase_name, (Node*)C->root());
5749 }
5750 #endif
5751 
5752 Node* Compile::narrow_value(BasicType bt, Node* value, const Type* type, PhaseGVN* phase, bool transform_res) {
5753   if (type != nullptr && phase->type(value)->higher_equal(type)) {
5754     return value;
5755   }
5756   Node* result = nullptr;
5757   if (bt == T_BYTE) {
5758     result = phase->transform(new LShiftINode(value, phase->intcon(24)));
5759     result = new RShiftINode(result, phase->intcon(24));
5760   } else if (bt == T_BOOLEAN) {
5761     result = new AndINode(value, phase->intcon(0xFF));
5762   } else if (bt == T_CHAR) {
5763     result = new AndINode(value,phase->intcon(0xFFFF));
5764   } else {
5765     assert(bt == T_SHORT, "unexpected narrow type");
5766     result = phase->transform(new LShiftINode(value, phase->intcon(16)));
5767     result = new RShiftINode(result, phase->intcon(16));
5768   }
5769   if (transform_res) {
5770     result = phase->transform(result);
5771   }
5772   return result;
5773 }
5774