1 /*
   2  * Copyright (c) 1997, 2024, 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/compilationFailureInfo.hpp"
  33 #include "compiler/compilationMemoryStatistic.hpp"
  34 #include "compiler/compileBroker.hpp"
  35 #include "compiler/compileLog.hpp"
  36 #include "compiler/compilerOracle.hpp"
  37 #include "compiler/compiler_globals.hpp"
  38 #include "compiler/disassembler.hpp"
  39 #include "compiler/oopMap.hpp"
  40 #include "gc/shared/barrierSet.hpp"
  41 #include "gc/shared/c2/barrierSetC2.hpp"
  42 #include "jfr/jfrEvents.hpp"
  43 #include "jvm_io.h"
  44 #include "memory/allocation.hpp"
  45 #include "memory/resourceArea.hpp"
  46 #include "opto/addnode.hpp"
  47 #include "opto/block.hpp"
  48 #include "opto/c2compiler.hpp"
  49 #include "opto/callGenerator.hpp"
  50 #include "opto/callnode.hpp"
  51 #include "opto/castnode.hpp"
  52 #include "opto/cfgnode.hpp"
  53 #include "opto/chaitin.hpp"
  54 #include "opto/compile.hpp"
  55 #include "opto/connode.hpp"
  56 #include "opto/convertnode.hpp"
  57 #include "opto/divnode.hpp"
  58 #include "opto/escape.hpp"
  59 #include "opto/idealGraphPrinter.hpp"
  60 #include "opto/locknode.hpp"
  61 #include "opto/loopnode.hpp"
  62 #include "opto/machnode.hpp"
  63 #include "opto/macro.hpp"
  64 #include "opto/matcher.hpp"
  65 #include "opto/mathexactnode.hpp"
  66 #include "opto/memnode.hpp"
  67 #include "opto/mulnode.hpp"
  68 #include "opto/narrowptrnode.hpp"
  69 #include "opto/node.hpp"
  70 #include "opto/opcodes.hpp"
  71 #include "opto/output.hpp"
  72 #include "opto/parse.hpp"
  73 #include "opto/phaseX.hpp"
  74 #include "opto/rootnode.hpp"
  75 #include "opto/runtime.hpp"
  76 #include "opto/stringopts.hpp"
  77 #include "opto/type.hpp"
  78 #include "opto/vector.hpp"
  79 #include "opto/vectornode.hpp"
  80 #include "runtime/globals_extension.hpp"
  81 #include "runtime/sharedRuntime.hpp"
  82 #include "runtime/signature.hpp"
  83 #include "runtime/stubRoutines.hpp"
  84 #include "runtime/timer.hpp"
  85 #include "utilities/align.hpp"
  86 #include "utilities/copy.hpp"
  87 #include "utilities/macros.hpp"
  88 #include "utilities/resourceHash.hpp"
  89 
  90 // -------------------- Compile::mach_constant_base_node -----------------------
  91 // Constant table base node singleton.
  92 MachConstantBaseNode* Compile::mach_constant_base_node() {
  93   if (_mach_constant_base_node == nullptr) {
  94     _mach_constant_base_node = new MachConstantBaseNode();
  95     _mach_constant_base_node->add_req(C->root());
  96   }
  97   return _mach_constant_base_node;
  98 }
  99 
 100 
 101 /// Support for intrinsics.
 102 
 103 // Return the index at which m must be inserted (or already exists).
 104 // The sort order is by the address of the ciMethod, with is_virtual as minor key.
 105 class IntrinsicDescPair {
 106  private:
 107   ciMethod* _m;
 108   bool _is_virtual;
 109  public:
 110   IntrinsicDescPair(ciMethod* m, bool is_virtual) : _m(m), _is_virtual(is_virtual) {}
 111   static int compare(IntrinsicDescPair* const& key, CallGenerator* const& elt) {
 112     ciMethod* m= elt->method();
 113     ciMethod* key_m = key->_m;
 114     if (key_m < m)      return -1;
 115     else if (key_m > m) return 1;
 116     else {
 117       bool is_virtual = elt->is_virtual();
 118       bool key_virtual = key->_is_virtual;
 119       if (key_virtual < is_virtual)      return -1;
 120       else if (key_virtual > is_virtual) return 1;
 121       else                               return 0;
 122     }
 123   }
 124 };
 125 int Compile::intrinsic_insertion_index(ciMethod* m, bool is_virtual, bool& found) {
 126 #ifdef ASSERT
 127   for (int i = 1; i < _intrinsics.length(); i++) {
 128     CallGenerator* cg1 = _intrinsics.at(i-1);
 129     CallGenerator* cg2 = _intrinsics.at(i);
 130     assert(cg1->method() != cg2->method()
 131            ? cg1->method()     < cg2->method()
 132            : cg1->is_virtual() < cg2->is_virtual(),
 133            "compiler intrinsics list must stay sorted");
 134   }
 135 #endif
 136   IntrinsicDescPair pair(m, is_virtual);
 137   return _intrinsics.find_sorted<IntrinsicDescPair*, IntrinsicDescPair::compare>(&pair, found);
 138 }
 139 
 140 void Compile::register_intrinsic(CallGenerator* cg) {
 141   bool found = false;
 142   int index = intrinsic_insertion_index(cg->method(), cg->is_virtual(), found);
 143   assert(!found, "registering twice");
 144   _intrinsics.insert_before(index, cg);
 145   assert(find_intrinsic(cg->method(), cg->is_virtual()) == cg, "registration worked");
 146 }
 147 
 148 CallGenerator* Compile::find_intrinsic(ciMethod* m, bool is_virtual) {
 149   assert(m->is_loaded(), "don't try this on unloaded methods");
 150   if (_intrinsics.length() > 0) {
 151     bool found = false;
 152     int index = intrinsic_insertion_index(m, is_virtual, found);
 153      if (found) {
 154       return _intrinsics.at(index);
 155     }
 156   }
 157   // Lazily create intrinsics for intrinsic IDs well-known in the runtime.
 158   if (m->intrinsic_id() != vmIntrinsics::_none &&
 159       m->intrinsic_id() <= vmIntrinsics::LAST_COMPILER_INLINE) {
 160     CallGenerator* cg = make_vm_intrinsic(m, is_virtual);
 161     if (cg != nullptr) {
 162       // Save it for next time:
 163       register_intrinsic(cg);
 164       return cg;
 165     } else {
 166       gather_intrinsic_statistics(m->intrinsic_id(), is_virtual, _intrinsic_disabled);
 167     }
 168   }
 169   return nullptr;
 170 }
 171 
 172 // Compile::make_vm_intrinsic is defined in library_call.cpp.
 173 
 174 #ifndef PRODUCT
 175 // statistics gathering...
 176 
 177 juint  Compile::_intrinsic_hist_count[vmIntrinsics::number_of_intrinsics()] = {0};
 178 jubyte Compile::_intrinsic_hist_flags[vmIntrinsics::number_of_intrinsics()] = {0};
 179 
 180 inline int as_int(vmIntrinsics::ID id) {
 181   return vmIntrinsics::as_int(id);
 182 }
 183 
 184 bool Compile::gather_intrinsic_statistics(vmIntrinsics::ID id, bool is_virtual, int flags) {
 185   assert(id > vmIntrinsics::_none && id < vmIntrinsics::ID_LIMIT, "oob");
 186   int oflags = _intrinsic_hist_flags[as_int(id)];
 187   assert(flags != 0, "what happened?");
 188   if (is_virtual) {
 189     flags |= _intrinsic_virtual;
 190   }
 191   bool changed = (flags != oflags);
 192   if ((flags & _intrinsic_worked) != 0) {
 193     juint count = (_intrinsic_hist_count[as_int(id)] += 1);
 194     if (count == 1) {
 195       changed = true;           // first time
 196     }
 197     // increment the overall count also:
 198     _intrinsic_hist_count[as_int(vmIntrinsics::_none)] += 1;
 199   }
 200   if (changed) {
 201     if (((oflags ^ flags) & _intrinsic_virtual) != 0) {
 202       // Something changed about the intrinsic's virtuality.
 203       if ((flags & _intrinsic_virtual) != 0) {
 204         // This is the first use of this intrinsic as a virtual call.
 205         if (oflags != 0) {
 206           // We already saw it as a non-virtual, so note both cases.
 207           flags |= _intrinsic_both;
 208         }
 209       } else if ((oflags & _intrinsic_both) == 0) {
 210         // This is the first use of this intrinsic as a non-virtual
 211         flags |= _intrinsic_both;
 212       }
 213     }
 214     _intrinsic_hist_flags[as_int(id)] = (jubyte) (oflags | flags);
 215   }
 216   // update the overall flags also:
 217   _intrinsic_hist_flags[as_int(vmIntrinsics::_none)] |= (jubyte) flags;
 218   return changed;
 219 }
 220 
 221 static char* format_flags(int flags, char* buf) {
 222   buf[0] = 0;
 223   if ((flags & Compile::_intrinsic_worked) != 0)    strcat(buf, ",worked");
 224   if ((flags & Compile::_intrinsic_failed) != 0)    strcat(buf, ",failed");
 225   if ((flags & Compile::_intrinsic_disabled) != 0)  strcat(buf, ",disabled");
 226   if ((flags & Compile::_intrinsic_virtual) != 0)   strcat(buf, ",virtual");
 227   if ((flags & Compile::_intrinsic_both) != 0)      strcat(buf, ",nonvirtual");
 228   if (buf[0] == 0)  strcat(buf, ",");
 229   assert(buf[0] == ',', "must be");
 230   return &buf[1];
 231 }
 232 
 233 void Compile::print_intrinsic_statistics() {
 234   char flagsbuf[100];
 235   ttyLocker ttyl;
 236   if (xtty != nullptr)  xtty->head("statistics type='intrinsic'");
 237   tty->print_cr("Compiler intrinsic usage:");
 238   juint total = _intrinsic_hist_count[as_int(vmIntrinsics::_none)];
 239   if (total == 0)  total = 1;  // avoid div0 in case of no successes
 240   #define PRINT_STAT_LINE(name, c, f) \
 241     tty->print_cr("  %4d (%4.1f%%) %s (%s)", (int)(c), ((c) * 100.0) / total, name, f);
 242   for (auto id : EnumRange<vmIntrinsicID>{}) {
 243     int   flags = _intrinsic_hist_flags[as_int(id)];
 244     juint count = _intrinsic_hist_count[as_int(id)];
 245     if ((flags | count) != 0) {
 246       PRINT_STAT_LINE(vmIntrinsics::name_at(id), count, format_flags(flags, flagsbuf));
 247     }
 248   }
 249   PRINT_STAT_LINE("total", total, format_flags(_intrinsic_hist_flags[as_int(vmIntrinsics::_none)], flagsbuf));
 250   if (xtty != nullptr)  xtty->tail("statistics");
 251 }
 252 
 253 void Compile::print_statistics() {
 254   { ttyLocker ttyl;
 255     if (xtty != nullptr)  xtty->head("statistics type='opto'");
 256     Parse::print_statistics();
 257     PhaseStringOpts::print_statistics();
 258     PhaseCCP::print_statistics();
 259     PhaseRegAlloc::print_statistics();
 260     PhaseOutput::print_statistics();
 261     PhasePeephole::print_statistics();
 262     PhaseIdealLoop::print_statistics();
 263     ConnectionGraph::print_statistics();
 264     PhaseMacroExpand::print_statistics();
 265     if (xtty != nullptr)  xtty->tail("statistics");
 266   }
 267   if (_intrinsic_hist_flags[as_int(vmIntrinsics::_none)] != 0) {
 268     // put this under its own <statistics> element.
 269     print_intrinsic_statistics();
 270   }
 271 }
 272 #endif //PRODUCT
 273 
 274 void Compile::gvn_replace_by(Node* n, Node* nn) {
 275   for (DUIterator_Last imin, i = n->last_outs(imin); i >= imin; ) {
 276     Node* use = n->last_out(i);
 277     bool is_in_table = initial_gvn()->hash_delete(use);
 278     uint uses_found = 0;
 279     for (uint j = 0; j < use->len(); j++) {
 280       if (use->in(j) == n) {
 281         if (j < use->req())
 282           use->set_req(j, nn);
 283         else
 284           use->set_prec(j, nn);
 285         uses_found++;
 286       }
 287     }
 288     if (is_in_table) {
 289       // reinsert into table
 290       initial_gvn()->hash_find_insert(use);
 291     }
 292     record_for_igvn(use);
 293     PhaseIterGVN::add_users_of_use_to_worklist(nn, use, *_igvn_worklist);
 294     i -= uses_found;    // we deleted 1 or more copies of this edge
 295   }
 296 }
 297 
 298 
 299 // Identify all nodes that are reachable from below, useful.
 300 // Use breadth-first pass that records state in a Unique_Node_List,
 301 // recursive traversal is slower.
 302 void Compile::identify_useful_nodes(Unique_Node_List &useful) {
 303   int estimated_worklist_size = live_nodes();
 304   useful.map( estimated_worklist_size, nullptr );  // preallocate space
 305 
 306   // Initialize worklist
 307   if (root() != nullptr)  { useful.push(root()); }
 308   // If 'top' is cached, declare it useful to preserve cached node
 309   if (cached_top_node())  { useful.push(cached_top_node()); }
 310 
 311   // Push all useful nodes onto the list, breadthfirst
 312   for( uint next = 0; next < useful.size(); ++next ) {
 313     assert( next < unique(), "Unique useful nodes < total nodes");
 314     Node *n  = useful.at(next);
 315     uint max = n->len();
 316     for( uint i = 0; i < max; ++i ) {
 317       Node *m = n->in(i);
 318       if (not_a_node(m))  continue;
 319       useful.push(m);
 320     }
 321   }
 322 }
 323 
 324 // Update dead_node_list with any missing dead nodes using useful
 325 // list. Consider all non-useful nodes to be useless i.e., dead nodes.
 326 void Compile::update_dead_node_list(Unique_Node_List &useful) {
 327   uint max_idx = unique();
 328   VectorSet& useful_node_set = useful.member_set();
 329 
 330   for (uint node_idx = 0; node_idx < max_idx; node_idx++) {
 331     // If node with index node_idx is not in useful set,
 332     // mark it as dead in dead node list.
 333     if (!useful_node_set.test(node_idx)) {
 334       record_dead_node(node_idx);
 335     }
 336   }
 337 }
 338 
 339 void Compile::remove_useless_late_inlines(GrowableArray<CallGenerator*>* inlines, Unique_Node_List &useful) {
 340   int shift = 0;
 341   for (int i = 0; i < inlines->length(); i++) {
 342     CallGenerator* cg = inlines->at(i);
 343     if (useful.member(cg->call_node())) {
 344       if (shift > 0) {
 345         inlines->at_put(i - shift, cg);
 346       }
 347     } else {
 348       shift++; // skip over the dead element
 349     }
 350   }
 351   if (shift > 0) {
 352     inlines->trunc_to(inlines->length() - shift); // remove last elements from compacted array
 353   }
 354 }
 355 
 356 void Compile::remove_useless_late_inlines(GrowableArray<CallGenerator*>* inlines, Node* dead) {
 357   assert(dead != nullptr && dead->is_Call(), "sanity");
 358   int found = 0;
 359   for (int i = 0; i < inlines->length(); i++) {
 360     if (inlines->at(i)->call_node() == dead) {
 361       inlines->remove_at(i);
 362       found++;
 363       NOT_DEBUG( break; ) // elements are unique, so exit early
 364     }
 365   }
 366   assert(found <= 1, "not unique");
 367 }
 368 
 369 template<typename N, ENABLE_IF_SDEFN(std::is_base_of<Node, N>::value)>
 370 void Compile::remove_useless_nodes(GrowableArray<N*>& node_list, Unique_Node_List& useful) {
 371   for (int i = node_list.length() - 1; i >= 0; i--) {
 372     N* node = node_list.at(i);
 373     if (!useful.member(node)) {
 374       node_list.delete_at(i); // replaces i-th with last element which is known to be useful (already processed)
 375     }
 376   }
 377 }
 378 
 379 void Compile::remove_useless_node(Node* dead) {
 380   remove_modified_node(dead);
 381 
 382   // Constant node that has no out-edges and has only one in-edge from
 383   // root is usually dead. However, sometimes reshaping walk makes
 384   // it reachable by adding use edges. So, we will NOT count Con nodes
 385   // as dead to be conservative about the dead node count at any
 386   // given time.
 387   if (!dead->is_Con()) {
 388     record_dead_node(dead->_idx);
 389   }
 390   if (dead->is_macro()) {
 391     remove_macro_node(dead);
 392   }
 393   if (dead->is_expensive()) {
 394     remove_expensive_node(dead);
 395   }
 396   if (dead->Opcode() == Op_Opaque4) {
 397     remove_template_assertion_predicate_opaq(dead);
 398   }
 399   if (dead->is_ParsePredicate()) {
 400     remove_parse_predicate(dead->as_ParsePredicate());
 401   }
 402   if (dead->for_post_loop_opts_igvn()) {
 403     remove_from_post_loop_opts_igvn(dead);
 404   }
 405   if (dead->is_Call()) {
 406     remove_useless_late_inlines(                &_late_inlines, dead);
 407     remove_useless_late_inlines(         &_string_late_inlines, dead);
 408     remove_useless_late_inlines(         &_boxing_late_inlines, dead);
 409     remove_useless_late_inlines(&_vector_reboxing_late_inlines, dead);
 410 
 411     if (dead->is_CallStaticJava()) {
 412       remove_unstable_if_trap(dead->as_CallStaticJava(), false);
 413     }
 414   }
 415   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 416   bs->unregister_potential_barrier_node(dead);
 417 }
 418 
 419 // Disconnect all useless nodes by disconnecting those at the boundary.
 420 void Compile::disconnect_useless_nodes(Unique_Node_List& useful, Unique_Node_List& worklist) {
 421   uint next = 0;
 422   while (next < useful.size()) {
 423     Node *n = useful.at(next++);
 424     if (n->is_SafePoint()) {
 425       // We're done with a parsing phase. Replaced nodes are not valid
 426       // beyond that point.
 427       n->as_SafePoint()->delete_replaced_nodes();
 428     }
 429     // Use raw traversal of out edges since this code removes out edges
 430     int max = n->outcnt();
 431     for (int j = 0; j < max; ++j) {
 432       Node* child = n->raw_out(j);
 433       if (!useful.member(child)) {
 434         assert(!child->is_top() || child != top(),
 435                "If top is cached in Compile object it is in useful list");
 436         // Only need to remove this out-edge to the useless node
 437         n->raw_del_out(j);
 438         --j;
 439         --max;
 440       }
 441     }
 442     if (n->outcnt() == 1 && n->has_special_unique_user()) {
 443       assert(useful.member(n->unique_out()), "do not push a useless node");
 444       worklist.push(n->unique_out());
 445     }
 446   }
 447 
 448   remove_useless_nodes(_macro_nodes,        useful); // remove useless macro nodes
 449   remove_useless_nodes(_parse_predicates,   useful); // remove useless Parse Predicate nodes
 450   remove_useless_nodes(_template_assertion_predicate_opaqs, useful); // remove useless Assertion Predicate opaque nodes
 451   remove_useless_nodes(_expensive_nodes,    useful); // remove useless expensive nodes
 452   remove_useless_nodes(_for_post_loop_igvn, useful); // remove useless node recorded for post loop opts IGVN pass
 453   remove_useless_unstable_if_traps(useful);          // remove useless unstable_if traps
 454   remove_useless_coarsened_locks(useful);            // remove useless coarsened locks nodes
 455 #ifdef ASSERT
 456   if (_modified_nodes != nullptr) {
 457     _modified_nodes->remove_useless_nodes(useful.member_set());
 458   }
 459 #endif
 460 
 461   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 462   bs->eliminate_useless_gc_barriers(useful, this);
 463   // clean up the late inline lists
 464   remove_useless_late_inlines(                &_late_inlines, useful);
 465   remove_useless_late_inlines(         &_string_late_inlines, useful);
 466   remove_useless_late_inlines(         &_boxing_late_inlines, useful);
 467   remove_useless_late_inlines(&_vector_reboxing_late_inlines, useful);
 468   debug_only(verify_graph_edges(true/*check for no_dead_code*/);)
 469 }
 470 
 471 // ============================================================================
 472 //------------------------------CompileWrapper---------------------------------
 473 class CompileWrapper : public StackObj {
 474   Compile *const _compile;
 475  public:
 476   CompileWrapper(Compile* compile);
 477 
 478   ~CompileWrapper();
 479 };
 480 
 481 CompileWrapper::CompileWrapper(Compile* compile) : _compile(compile) {
 482   // the Compile* pointer is stored in the current ciEnv:
 483   ciEnv* env = compile->env();
 484   assert(env == ciEnv::current(), "must already be a ciEnv active");
 485   assert(env->compiler_data() == nullptr, "compile already active?");
 486   env->set_compiler_data(compile);
 487   assert(compile == Compile::current(), "sanity");
 488 
 489   compile->set_type_dict(nullptr);
 490   compile->set_clone_map(new Dict(cmpkey, hashkey, _compile->comp_arena()));
 491   compile->clone_map().set_clone_idx(0);
 492   compile->set_type_last_size(0);
 493   compile->set_last_tf(nullptr, nullptr);
 494   compile->set_indexSet_arena(nullptr);
 495   compile->set_indexSet_free_block_list(nullptr);
 496   compile->init_type_arena();
 497   Type::Initialize(compile);
 498   _compile->begin_method();
 499   _compile->clone_map().set_debug(_compile->has_method() && _compile->directive()->CloneMapDebugOption);
 500 }
 501 CompileWrapper::~CompileWrapper() {
 502   // simulate crash during compilation
 503   assert(CICrashAt < 0 || _compile->compile_id() != CICrashAt, "just as planned");
 504 
 505   _compile->end_method();
 506   _compile->env()->set_compiler_data(nullptr);
 507 }
 508 
 509 
 510 //----------------------------print_compile_messages---------------------------
 511 void Compile::print_compile_messages() {
 512 #ifndef PRODUCT
 513   // Check if recompiling
 514   if (!subsume_loads() && PrintOpto) {
 515     // Recompiling without allowing machine instructions to subsume loads
 516     tty->print_cr("*********************************************************");
 517     tty->print_cr("** Bailout: Recompile without subsuming loads          **");
 518     tty->print_cr("*********************************************************");
 519   }
 520   if ((do_escape_analysis() != DoEscapeAnalysis) && PrintOpto) {
 521     // Recompiling without escape analysis
 522     tty->print_cr("*********************************************************");
 523     tty->print_cr("** Bailout: Recompile without escape analysis          **");
 524     tty->print_cr("*********************************************************");
 525   }
 526   if (do_iterative_escape_analysis() != DoEscapeAnalysis && PrintOpto) {
 527     // Recompiling without iterative escape analysis
 528     tty->print_cr("*********************************************************");
 529     tty->print_cr("** Bailout: Recompile without iterative escape analysis**");
 530     tty->print_cr("*********************************************************");
 531   }
 532   if (do_reduce_allocation_merges() != ReduceAllocationMerges && PrintOpto) {
 533     // Recompiling without reducing allocation merges
 534     tty->print_cr("*********************************************************");
 535     tty->print_cr("** Bailout: Recompile without reduce allocation merges **");
 536     tty->print_cr("*********************************************************");
 537   }
 538   if ((eliminate_boxing() != EliminateAutoBox) && PrintOpto) {
 539     // Recompiling without boxing elimination
 540     tty->print_cr("*********************************************************");
 541     tty->print_cr("** Bailout: Recompile without boxing elimination       **");
 542     tty->print_cr("*********************************************************");
 543   }
 544   if ((do_locks_coarsening() != EliminateLocks) && PrintOpto) {
 545     // Recompiling without locks coarsening
 546     tty->print_cr("*********************************************************");
 547     tty->print_cr("** Bailout: Recompile without locks coarsening         **");
 548     tty->print_cr("*********************************************************");
 549   }
 550   if (env()->break_at_compile()) {
 551     // Open the debugger when compiling this method.
 552     tty->print("### Breaking when compiling: ");
 553     method()->print_short_name();
 554     tty->cr();
 555     BREAKPOINT;
 556   }
 557 
 558   if( PrintOpto ) {
 559     if (is_osr_compilation()) {
 560       tty->print("[OSR]%3d", _compile_id);
 561     } else {
 562       tty->print("%3d", _compile_id);
 563     }
 564   }
 565 #endif
 566 }
 567 
 568 #ifndef PRODUCT
 569 void Compile::print_ideal_ir(const char* phase_name) {
 570   // keep the following output all in one block
 571   // This output goes directly to the tty, not the compiler log.
 572   // To enable tools to match it up with the compilation activity,
 573   // be sure to tag this tty output with the compile ID.
 574 
 575   // Node dumping can cause a safepoint, which can break the tty lock.
 576   // Buffer all node dumps, so that all safepoints happen before we lock.
 577   ResourceMark rm;
 578   stringStream ss;
 579 
 580   if (_output == nullptr) {
 581     ss.print_cr("AFTER: %s", phase_name);
 582     // Print out all nodes in ascending order of index.
 583     root()->dump_bfs(MaxNodeLimit, nullptr, "+S$", &ss);
 584   } else {
 585     // Dump the node blockwise if we have a scheduling
 586     _output->print_scheduling(&ss);
 587   }
 588 
 589   // Check that the lock is not broken by a safepoint.
 590   NoSafepointVerifier nsv;
 591   ttyLocker ttyl;
 592   if (xtty != nullptr) {
 593     xtty->head("ideal compile_id='%d'%s compile_phase='%s'",
 594                compile_id(),
 595                is_osr_compilation() ? " compile_kind='osr'" : "",
 596                phase_name);
 597   }
 598 
 599   tty->print("%s", ss.as_string());
 600 
 601   if (xtty != nullptr) {
 602     xtty->tail("ideal");
 603   }
 604 }
 605 #endif
 606 
 607 // ============================================================================
 608 //------------------------------Compile standard-------------------------------
 609 
 610 // Compile a method.  entry_bci is -1 for normal compilations and indicates
 611 // the continuation bci for on stack replacement.
 612 
 613 
 614 Compile::Compile( ciEnv* ci_env, ciMethod* target, int osr_bci,
 615                   Options options, DirectiveSet* directive)
 616                 : Phase(Compiler),
 617                   _compile_id(ci_env->compile_id()),
 618                   _options(options),
 619                   _method(target),
 620                   _entry_bci(osr_bci),
 621                   _ilt(nullptr),
 622                   _stub_function(nullptr),
 623                   _stub_name(nullptr),
 624                   _stub_entry_point(nullptr),
 625                   _max_node_limit(MaxNodeLimit),
 626                   _post_loop_opts_phase(false),
 627                   _allow_macro_nodes(true),
 628                   _inlining_progress(false),
 629                   _inlining_incrementally(false),
 630                   _do_cleanup(false),
 631                   _has_reserved_stack_access(target->has_reserved_stack_access()),
 632 #ifndef PRODUCT
 633                   _igv_idx(0),
 634                   _trace_opto_output(directive->TraceOptoOutputOption),
 635 #endif
 636                   _has_method_handle_invokes(false),
 637                   _clinit_barrier_on_entry(false),
 638                   _stress_seed(0),
 639                   _comp_arena(mtCompiler),
 640                   _barrier_set_state(BarrierSet::barrier_set()->barrier_set_c2()->create_barrier_state(comp_arena())),
 641                   _env(ci_env),
 642                   _directive(directive),
 643                   _log(ci_env->log()),
 644                   _first_failure_details(nullptr),
 645                   _intrinsics        (comp_arena(), 0, 0, nullptr),
 646                   _macro_nodes       (comp_arena(), 8, 0, nullptr),
 647                   _parse_predicates  (comp_arena(), 8, 0, nullptr),
 648                   _template_assertion_predicate_opaqs (comp_arena(), 8, 0, nullptr),
 649                   _expensive_nodes   (comp_arena(), 8, 0, nullptr),
 650                   _for_post_loop_igvn(comp_arena(), 8, 0, nullptr),
 651                   _unstable_if_traps (comp_arena(), 8, 0, nullptr),
 652                   _coarsened_locks   (comp_arena(), 8, 0, nullptr),
 653                   _congraph(nullptr),
 654                   NOT_PRODUCT(_igv_printer(nullptr) COMMA)
 655                   _unique(0),
 656                   _dead_node_count(0),
 657                   _dead_node_list(comp_arena()),
 658                   _node_arena_one(mtCompiler, Arena::Tag::tag_node),
 659                   _node_arena_two(mtCompiler, Arena::Tag::tag_node),
 660                   _node_arena(&_node_arena_one),
 661                   _mach_constant_base_node(nullptr),
 662                   _Compile_types(mtCompiler),
 663                   _initial_gvn(nullptr),
 664                   _igvn_worklist(nullptr),
 665                   _types(nullptr),
 666                   _node_hash(nullptr),
 667                   _late_inlines(comp_arena(), 2, 0, nullptr),
 668                   _string_late_inlines(comp_arena(), 2, 0, nullptr),
 669                   _boxing_late_inlines(comp_arena(), 2, 0, nullptr),
 670                   _vector_reboxing_late_inlines(comp_arena(), 2, 0, nullptr),
 671                   _late_inlines_pos(0),
 672                   _number_of_mh_late_inlines(0),
 673                   _oom(false),
 674                   _print_inlining_stream(new (mtCompiler) stringStream()),
 675                   _print_inlining_list(nullptr),
 676                   _print_inlining_idx(0),
 677                   _print_inlining_output(nullptr),
 678                   _replay_inline_data(nullptr),
 679                   _java_calls(0),
 680                   _inner_loops(0),
 681                   _interpreter_frame_size(0),
 682                   _output(nullptr)
 683 #ifndef PRODUCT
 684                   , _in_dump_cnt(0)
 685 #endif
 686 {
 687   C = this;
 688   CompileWrapper cw(this);
 689 
 690   TraceTime t1("Total compilation time", &_t_totalCompilation, CITime, CITimeVerbose);
 691   TraceTime t2(nullptr, &_t_methodCompilation, CITime, false);
 692 
 693 #if defined(SUPPORT_ASSEMBLY) || defined(SUPPORT_ABSTRACT_ASSEMBLY)
 694   bool print_opto_assembly = directive->PrintOptoAssemblyOption;
 695   // We can always print a disassembly, either abstract (hex dump) or
 696   // with the help of a suitable hsdis library. Thus, we should not
 697   // couple print_assembly and print_opto_assembly controls.
 698   // But: always print opto and regular assembly on compile command 'print'.
 699   bool print_assembly = directive->PrintAssemblyOption;
 700   set_print_assembly(print_opto_assembly || print_assembly);
 701 #else
 702   set_print_assembly(false); // must initialize.
 703 #endif
 704 
 705 #ifndef PRODUCT
 706   set_parsed_irreducible_loop(false);
 707 #endif
 708 
 709   if (directive->ReplayInlineOption) {
 710     _replay_inline_data = ciReplay::load_inline_data(method(), entry_bci(), ci_env->comp_level());
 711   }
 712   set_print_inlining(directive->PrintInliningOption || PrintOptoInlining);
 713   set_print_intrinsics(directive->PrintIntrinsicsOption);
 714   set_has_irreducible_loop(true); // conservative until build_loop_tree() reset it
 715 
 716   if (ProfileTraps) {
 717     // Make sure the method being compiled gets its own MDO,
 718     // so we can at least track the decompile_count().
 719     method()->ensure_method_data();
 720   }
 721 
 722   if (StressLCM || StressGCM || StressIGVN || StressCCP ||
 723       StressIncrementalInlining || StressMacroExpansion || StressUnstableIfTraps || StressBailout) {
 724     initialize_stress_seed(directive);
 725   }
 726 
 727   Init(/*do_aliasing=*/ true);
 728 
 729   print_compile_messages();
 730 
 731   _ilt = InlineTree::build_inline_tree_root();
 732 
 733   // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
 734   assert(num_alias_types() >= AliasIdxRaw, "");
 735 
 736 #define MINIMUM_NODE_HASH  1023
 737 
 738   // GVN that will be run immediately on new nodes
 739   uint estimated_size = method()->code_size()*4+64;
 740   estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
 741   _igvn_worklist = new (comp_arena()) Unique_Node_List(comp_arena());
 742   _types = new (comp_arena()) Type_Array(comp_arena());
 743   _node_hash = new (comp_arena()) NodeHash(comp_arena(), estimated_size);
 744   PhaseGVN gvn;
 745   set_initial_gvn(&gvn);
 746 
 747   print_inlining_init();
 748   { // Scope for timing the parser
 749     TracePhase tp("parse", &timers[_t_parser]);
 750 
 751     // Put top into the hash table ASAP.
 752     initial_gvn()->transform(top());
 753 
 754     // Set up tf(), start(), and find a CallGenerator.
 755     CallGenerator* cg = nullptr;
 756     if (is_osr_compilation()) {
 757       const TypeTuple *domain = StartOSRNode::osr_domain();
 758       const TypeTuple *range = TypeTuple::make_range(method()->signature());
 759       init_tf(TypeFunc::make(domain, range));
 760       StartNode* s = new StartOSRNode(root(), domain);
 761       initial_gvn()->set_type_bottom(s);
 762       verify_start(s);
 763       cg = CallGenerator::for_osr(method(), entry_bci());
 764     } else {
 765       // Normal case.
 766       init_tf(TypeFunc::make(method()));
 767       StartNode* s = new StartNode(root(), tf()->domain());
 768       initial_gvn()->set_type_bottom(s);
 769       verify_start(s);
 770       if (method()->intrinsic_id() == vmIntrinsics::_Reference_get) {
 771         // With java.lang.ref.reference.get() we must go through the
 772         // intrinsic - even when get() is the root
 773         // method of the compile - so that, if necessary, the value in
 774         // the referent field of the reference object gets recorded by
 775         // the pre-barrier code.
 776         cg = find_intrinsic(method(), false);
 777       }
 778       if (cg == nullptr) {
 779         float past_uses = method()->interpreter_invocation_count();
 780         float expected_uses = past_uses;
 781         cg = CallGenerator::for_inline(method(), expected_uses);
 782       }
 783     }
 784     if (failing())  return;
 785     if (cg == nullptr) {
 786       const char* reason = InlineTree::check_can_parse(method());
 787       assert(reason != nullptr, "expect reason for parse failure");
 788       stringStream ss;
 789       ss.print("cannot parse method: %s", reason);
 790       record_method_not_compilable(ss.as_string());
 791       return;
 792     }
 793 
 794     gvn.set_type(root(), root()->bottom_type());
 795 
 796     JVMState* jvms = build_start_state(start(), tf());
 797     if ((jvms = cg->generate(jvms)) == nullptr) {
 798       assert(failure_reason() != nullptr, "expect reason for parse failure");
 799       stringStream ss;
 800       ss.print("method parse failed: %s", failure_reason());
 801       record_method_not_compilable(ss.as_string() DEBUG_ONLY(COMMA true));
 802       return;
 803     }
 804     GraphKit kit(jvms);
 805 
 806     if (!kit.stopped()) {
 807       // Accept return values, and transfer control we know not where.
 808       // This is done by a special, unique ReturnNode bound to root.
 809       return_values(kit.jvms());
 810     }
 811 
 812     if (kit.has_exceptions()) {
 813       // Any exceptions that escape from this call must be rethrown
 814       // to whatever caller is dynamically above us on the stack.
 815       // This is done by a special, unique RethrowNode bound to root.
 816       rethrow_exceptions(kit.transfer_exceptions_into_jvms());
 817     }
 818 
 819     assert(IncrementalInline || (_late_inlines.length() == 0 && !has_mh_late_inlines()), "incremental inlining is off");
 820 
 821     if (_late_inlines.length() == 0 && !has_mh_late_inlines() && !failing() && has_stringbuilder()) {
 822       inline_string_calls(true);
 823     }
 824 
 825     if (failing())  return;
 826 
 827     // Remove clutter produced by parsing.
 828     if (!failing()) {
 829       ResourceMark rm;
 830       PhaseRemoveUseless pru(initial_gvn(), *igvn_worklist());
 831     }
 832   }
 833 
 834   // Note:  Large methods are capped off in do_one_bytecode().
 835   if (failing())  return;
 836 
 837   // After parsing, node notes are no longer automagic.
 838   // They must be propagated by register_new_node_with_optimizer(),
 839   // clone(), or the like.
 840   set_default_node_notes(nullptr);
 841 
 842 #ifndef PRODUCT
 843   if (should_print_igv(1)) {
 844     _igv_printer->print_inlining();
 845   }
 846 #endif
 847 
 848   if (failing())  return;
 849   NOT_PRODUCT( verify_graph_edges(); )
 850 
 851   // Now optimize
 852   Optimize();
 853   if (failing())  return;
 854   NOT_PRODUCT( verify_graph_edges(); )
 855 
 856 #ifndef PRODUCT
 857   if (should_print_ideal()) {
 858     print_ideal_ir("print_ideal");
 859   }
 860 #endif
 861 
 862 #ifdef ASSERT
 863   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 864   bs->verify_gc_barriers(this, BarrierSetC2::BeforeCodeGen);
 865 #endif
 866 
 867   // Dump compilation data to replay it.
 868   if (directive->DumpReplayOption) {
 869     env()->dump_replay_data(_compile_id);
 870   }
 871   if (directive->DumpInlineOption && (ilt() != nullptr)) {
 872     env()->dump_inline_data(_compile_id);
 873   }
 874 
 875   // Now that we know the size of all the monitors we can add a fixed slot
 876   // for the original deopt pc.
 877   int next_slot = fixed_slots() + (sizeof(address) / VMRegImpl::stack_slot_size);
 878   set_fixed_slots(next_slot);
 879 
 880   // Compute when to use implicit null checks. Used by matching trap based
 881   // nodes and NullCheck optimization.
 882   set_allowed_deopt_reasons();
 883 
 884   // Now generate code
 885   Code_Gen();
 886 }
 887 
 888 //------------------------------Compile----------------------------------------
 889 // Compile a runtime stub
 890 Compile::Compile( ciEnv* ci_env,
 891                   TypeFunc_generator generator,
 892                   address stub_function,
 893                   const char *stub_name,
 894                   int is_fancy_jump,
 895                   bool pass_tls,
 896                   bool return_pc,
 897                   DirectiveSet* directive)
 898   : Phase(Compiler),
 899     _compile_id(0),
 900     _options(Options::for_runtime_stub()),
 901     _method(nullptr),
 902     _entry_bci(InvocationEntryBci),
 903     _stub_function(stub_function),
 904     _stub_name(stub_name),
 905     _stub_entry_point(nullptr),
 906     _max_node_limit(MaxNodeLimit),
 907     _post_loop_opts_phase(false),
 908     _allow_macro_nodes(true),
 909     _inlining_progress(false),
 910     _inlining_incrementally(false),
 911     _has_reserved_stack_access(false),
 912 #ifndef PRODUCT
 913     _igv_idx(0),
 914     _trace_opto_output(directive->TraceOptoOutputOption),
 915 #endif
 916     _has_method_handle_invokes(false),
 917     _clinit_barrier_on_entry(false),
 918     _stress_seed(0),
 919     _comp_arena(mtCompiler),
 920     _barrier_set_state(BarrierSet::barrier_set()->barrier_set_c2()->create_barrier_state(comp_arena())),
 921     _env(ci_env),
 922     _directive(directive),
 923     _log(ci_env->log()),
 924     _first_failure_details(nullptr),
 925     _for_post_loop_igvn(comp_arena(), 8, 0, nullptr),
 926     _congraph(nullptr),
 927     NOT_PRODUCT(_igv_printer(nullptr) COMMA)
 928     _unique(0),
 929     _dead_node_count(0),
 930     _dead_node_list(comp_arena()),
 931     _node_arena_one(mtCompiler),
 932     _node_arena_two(mtCompiler),
 933     _node_arena(&_node_arena_one),
 934     _mach_constant_base_node(nullptr),
 935     _Compile_types(mtCompiler),
 936     _initial_gvn(nullptr),
 937     _igvn_worklist(nullptr),
 938     _types(nullptr),
 939     _node_hash(nullptr),
 940     _number_of_mh_late_inlines(0),
 941     _oom(false),
 942     _print_inlining_stream(new (mtCompiler) stringStream()),
 943     _print_inlining_list(nullptr),
 944     _print_inlining_idx(0),
 945     _print_inlining_output(nullptr),
 946     _replay_inline_data(nullptr),
 947     _java_calls(0),
 948     _inner_loops(0),
 949     _interpreter_frame_size(0),
 950     _output(nullptr),
 951 #ifndef PRODUCT
 952     _in_dump_cnt(0),
 953 #endif
 954     _allowed_reasons(0) {
 955   C = this;
 956 
 957   TraceTime t1(nullptr, &_t_totalCompilation, CITime, false);
 958   TraceTime t2(nullptr, &_t_stubCompilation, CITime, false);
 959 
 960 #ifndef PRODUCT
 961   set_print_assembly(PrintFrameConverterAssembly);
 962   set_parsed_irreducible_loop(false);
 963 #else
 964   set_print_assembly(false); // Must initialize.
 965 #endif
 966   set_has_irreducible_loop(false); // no loops
 967 
 968   CompileWrapper cw(this);
 969   Init(/*do_aliasing=*/ false);
 970   init_tf((*generator)());
 971 
 972   _igvn_worklist = new (comp_arena()) Unique_Node_List(comp_arena());
 973   _types = new (comp_arena()) Type_Array(comp_arena());
 974   _node_hash = new (comp_arena()) NodeHash(comp_arena(), 255);
 975 
 976   if (StressLCM || StressGCM || StressBailout) {
 977     initialize_stress_seed(directive);
 978   }
 979 
 980   {
 981     PhaseGVN gvn;
 982     set_initial_gvn(&gvn);    // not significant, but GraphKit guys use it pervasively
 983     gvn.transform(top());
 984 
 985     GraphKit kit;
 986     kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
 987   }
 988 
 989   NOT_PRODUCT( verify_graph_edges(); )
 990 
 991   Code_Gen();
 992 }
 993 
 994 Compile::~Compile() {
 995   delete _print_inlining_stream;
 996   delete _first_failure_details;
 997 };
 998 
 999 //------------------------------Init-------------------------------------------
1000 // Prepare for a single compilation
1001 void Compile::Init(bool aliasing) {
1002   _do_aliasing = aliasing;
1003   _unique  = 0;
1004   _regalloc = nullptr;
1005 
1006   _tf      = nullptr;  // filled in later
1007   _top     = nullptr;  // cached later
1008   _matcher = nullptr;  // filled in later
1009   _cfg     = nullptr;  // filled in later
1010 
1011   IA32_ONLY( set_24_bit_selection_and_mode(true, false); )
1012 
1013   _node_note_array = nullptr;
1014   _default_node_notes = nullptr;
1015   DEBUG_ONLY( _modified_nodes = nullptr; ) // Used in Optimize()
1016 
1017   _immutable_memory = nullptr; // filled in at first inquiry
1018 
1019 #ifdef ASSERT
1020   _phase_optimize_finished = false;
1021   _phase_verify_ideal_loop = false;
1022   _exception_backedge = false;
1023   _type_verify = nullptr;
1024 #endif
1025 
1026   // Globally visible Nodes
1027   // First set TOP to null to give safe behavior during creation of RootNode
1028   set_cached_top_node(nullptr);
1029   set_root(new RootNode());
1030   // Now that you have a Root to point to, create the real TOP
1031   set_cached_top_node( new ConNode(Type::TOP) );
1032   set_recent_alloc(nullptr, nullptr);
1033 
1034   // Create Debug Information Recorder to record scopes, oopmaps, etc.
1035   env()->set_oop_recorder(new OopRecorder(env()->arena()));
1036   env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
1037   env()->set_dependencies(new Dependencies(env()));
1038 
1039   _fixed_slots = 0;
1040   set_has_split_ifs(false);
1041   set_has_loops(false); // first approximation
1042   set_has_stringbuilder(false);
1043   set_has_boxed_value(false);
1044   _trap_can_recompile = false;  // no traps emitted yet
1045   _major_progress = true; // start out assuming good things will happen
1046   set_has_unsafe_access(false);
1047   set_max_vector_size(0);
1048   set_clear_upper_avx(false);  //false as default for clear upper bits of ymm registers
1049   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
1050   set_decompile_count(0);
1051 
1052 #ifndef PRODUCT
1053   Copy::zero_to_bytes(_igv_phase_iter, sizeof(_igv_phase_iter));
1054 #endif
1055 
1056   set_do_freq_based_layout(_directive->BlockLayoutByFrequencyOption);
1057   _loop_opts_cnt = LoopOptsCount;
1058   set_do_inlining(Inline);
1059   set_max_inline_size(MaxInlineSize);
1060   set_freq_inline_size(FreqInlineSize);
1061   set_do_scheduling(OptoScheduling);
1062 
1063   set_do_vector_loop(false);
1064   set_has_monitors(false);
1065   set_has_scoped_access(false);
1066 
1067   if (AllowVectorizeOnDemand) {
1068     if (has_method() && _directive->VectorizeOption) {
1069       set_do_vector_loop(true);
1070       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());})
1071     } else if (has_method() && method()->name() != nullptr &&
1072                method()->intrinsic_id() == vmIntrinsics::_forEachRemaining) {
1073       set_do_vector_loop(true);
1074     }
1075   }
1076   set_use_cmove(UseCMoveUnconditionally /* || do_vector_loop()*/); //TODO: consider do_vector_loop() mandate use_cmove unconditionally
1077   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());})
1078 
1079   _max_node_limit = _directive->MaxNodeLimitOption;
1080 
1081   if (VM_Version::supports_fast_class_init_checks() && has_method() && !is_osr_compilation() && method()->needs_clinit_barrier()) {
1082     set_clinit_barrier_on_entry(true);
1083   }
1084   if (debug_info()->recording_non_safepoints()) {
1085     set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
1086                         (comp_arena(), 8, 0, nullptr));
1087     set_default_node_notes(Node_Notes::make(this));
1088   }
1089 
1090   const int grow_ats = 16;
1091   _max_alias_types = grow_ats;
1092   _alias_types   = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
1093   AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType,  grow_ats);
1094   Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
1095   {
1096     for (int i = 0; i < grow_ats; i++)  _alias_types[i] = &ats[i];
1097   }
1098   // Initialize the first few types.
1099   _alias_types[AliasIdxTop]->Init(AliasIdxTop, nullptr);
1100   _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
1101   _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
1102   _num_alias_types = AliasIdxRaw+1;
1103   // Zero out the alias type cache.
1104   Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
1105   // A null adr_type hits in the cache right away.  Preload the right answer.
1106   probe_alias_cache(nullptr)->_index = AliasIdxTop;
1107 }
1108 
1109 #ifdef ASSERT
1110 // Verify that the current StartNode is valid.
1111 void Compile::verify_start(StartNode* s) const {
1112   assert(failing_internal() || s == start(), "should be StartNode");
1113 }
1114 #endif
1115 
1116 /**
1117  * Return the 'StartNode'. We must not have a pending failure, since the ideal graph
1118  * can be in an inconsistent state, i.e., we can get segmentation faults when traversing
1119  * the ideal graph.
1120  */
1121 StartNode* Compile::start() const {
1122   assert (!failing_internal() || C->failure_is_artificial(), "Must not have pending failure. Reason is: %s", failure_reason());
1123   for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
1124     Node* start = root()->fast_out(i);
1125     if (start->is_Start()) {
1126       return start->as_Start();
1127     }
1128   }
1129   fatal("Did not find Start node!");
1130   return nullptr;
1131 }
1132 
1133 //-------------------------------immutable_memory-------------------------------------
1134 // Access immutable memory
1135 Node* Compile::immutable_memory() {
1136   if (_immutable_memory != nullptr) {
1137     return _immutable_memory;
1138   }
1139   StartNode* s = start();
1140   for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
1141     Node *p = s->fast_out(i);
1142     if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
1143       _immutable_memory = p;
1144       return _immutable_memory;
1145     }
1146   }
1147   ShouldNotReachHere();
1148   return nullptr;
1149 }
1150 
1151 //----------------------set_cached_top_node------------------------------------
1152 // Install the cached top node, and make sure Node::is_top works correctly.
1153 void Compile::set_cached_top_node(Node* tn) {
1154   if (tn != nullptr)  verify_top(tn);
1155   Node* old_top = _top;
1156   _top = tn;
1157   // Calling Node::setup_is_top allows the nodes the chance to adjust
1158   // their _out arrays.
1159   if (_top != nullptr)     _top->setup_is_top();
1160   if (old_top != nullptr)  old_top->setup_is_top();
1161   assert(_top == nullptr || top()->is_top(), "");
1162 }
1163 
1164 #ifdef ASSERT
1165 uint Compile::count_live_nodes_by_graph_walk() {
1166   Unique_Node_List useful(comp_arena());
1167   // Get useful node list by walking the graph.
1168   identify_useful_nodes(useful);
1169   return useful.size();
1170 }
1171 
1172 void Compile::print_missing_nodes() {
1173 
1174   // Return if CompileLog is null and PrintIdealNodeCount is false.
1175   if ((_log == nullptr) && (! PrintIdealNodeCount)) {
1176     return;
1177   }
1178 
1179   // This is an expensive function. It is executed only when the user
1180   // specifies VerifyIdealNodeCount option or otherwise knows the
1181   // additional work that needs to be done to identify reachable nodes
1182   // by walking the flow graph and find the missing ones using
1183   // _dead_node_list.
1184 
1185   Unique_Node_List useful(comp_arena());
1186   // Get useful node list by walking the graph.
1187   identify_useful_nodes(useful);
1188 
1189   uint l_nodes = C->live_nodes();
1190   uint l_nodes_by_walk = useful.size();
1191 
1192   if (l_nodes != l_nodes_by_walk) {
1193     if (_log != nullptr) {
1194       _log->begin_head("mismatched_nodes count='%d'", abs((int) (l_nodes - l_nodes_by_walk)));
1195       _log->stamp();
1196       _log->end_head();
1197     }
1198     VectorSet& useful_member_set = useful.member_set();
1199     int last_idx = l_nodes_by_walk;
1200     for (int i = 0; i < last_idx; i++) {
1201       if (useful_member_set.test(i)) {
1202         if (_dead_node_list.test(i)) {
1203           if (_log != nullptr) {
1204             _log->elem("mismatched_node_info node_idx='%d' type='both live and dead'", i);
1205           }
1206           if (PrintIdealNodeCount) {
1207             // Print the log message to tty
1208               tty->print_cr("mismatched_node idx='%d' both live and dead'", i);
1209               useful.at(i)->dump();
1210           }
1211         }
1212       }
1213       else if (! _dead_node_list.test(i)) {
1214         if (_log != nullptr) {
1215           _log->elem("mismatched_node_info node_idx='%d' type='neither live nor dead'", i);
1216         }
1217         if (PrintIdealNodeCount) {
1218           // Print the log message to tty
1219           tty->print_cr("mismatched_node idx='%d' type='neither live nor dead'", i);
1220         }
1221       }
1222     }
1223     if (_log != nullptr) {
1224       _log->tail("mismatched_nodes");
1225     }
1226   }
1227 }
1228 void Compile::record_modified_node(Node* n) {
1229   if (_modified_nodes != nullptr && !_inlining_incrementally && !n->is_Con()) {
1230     _modified_nodes->push(n);
1231   }
1232 }
1233 
1234 void Compile::remove_modified_node(Node* n) {
1235   if (_modified_nodes != nullptr) {
1236     _modified_nodes->remove(n);
1237   }
1238 }
1239 #endif
1240 
1241 #ifndef PRODUCT
1242 void Compile::verify_top(Node* tn) const {
1243   if (tn != nullptr) {
1244     assert(tn->is_Con(), "top node must be a constant");
1245     assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
1246     assert(tn->in(0) != nullptr, "must have live top node");
1247   }
1248 }
1249 #endif
1250 
1251 
1252 ///-------------------Managing Per-Node Debug & Profile Info-------------------
1253 
1254 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
1255   guarantee(arr != nullptr, "");
1256   int num_blocks = arr->length();
1257   if (grow_by < num_blocks)  grow_by = num_blocks;
1258   int num_notes = grow_by * _node_notes_block_size;
1259   Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
1260   Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
1261   while (num_notes > 0) {
1262     arr->append(notes);
1263     notes     += _node_notes_block_size;
1264     num_notes -= _node_notes_block_size;
1265   }
1266   assert(num_notes == 0, "exact multiple, please");
1267 }
1268 
1269 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
1270   if (source == nullptr || dest == nullptr)  return false;
1271 
1272   if (dest->is_Con())
1273     return false;               // Do not push debug info onto constants.
1274 
1275 #ifdef ASSERT
1276   // Leave a bread crumb trail pointing to the original node:
1277   if (dest != nullptr && dest != source && dest->debug_orig() == nullptr) {
1278     dest->set_debug_orig(source);
1279   }
1280 #endif
1281 
1282   if (node_note_array() == nullptr)
1283     return false;               // Not collecting any notes now.
1284 
1285   // This is a copy onto a pre-existing node, which may already have notes.
1286   // If both nodes have notes, do not overwrite any pre-existing notes.
1287   Node_Notes* source_notes = node_notes_at(source->_idx);
1288   if (source_notes == nullptr || source_notes->is_clear())  return false;
1289   Node_Notes* dest_notes   = node_notes_at(dest->_idx);
1290   if (dest_notes == nullptr || dest_notes->is_clear()) {
1291     return set_node_notes_at(dest->_idx, source_notes);
1292   }
1293 
1294   Node_Notes merged_notes = (*source_notes);
1295   // The order of operations here ensures that dest notes will win...
1296   merged_notes.update_from(dest_notes);
1297   return set_node_notes_at(dest->_idx, &merged_notes);
1298 }
1299 
1300 
1301 //--------------------------allow_range_check_smearing-------------------------
1302 // Gating condition for coalescing similar range checks.
1303 // Sometimes we try 'speculatively' replacing a series of a range checks by a
1304 // single covering check that is at least as strong as any of them.
1305 // If the optimization succeeds, the simplified (strengthened) range check
1306 // will always succeed.  If it fails, we will deopt, and then give up
1307 // on the optimization.
1308 bool Compile::allow_range_check_smearing() const {
1309   // If this method has already thrown a range-check,
1310   // assume it was because we already tried range smearing
1311   // and it failed.
1312   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
1313   return !already_trapped;
1314 }
1315 
1316 
1317 //------------------------------flatten_alias_type-----------------------------
1318 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
1319   assert(do_aliasing(), "Aliasing should be enabled");
1320   int offset = tj->offset();
1321   TypePtr::PTR ptr = tj->ptr();
1322 
1323   // Known instance (scalarizable allocation) alias only with itself.
1324   bool is_known_inst = tj->isa_oopptr() != nullptr &&
1325                        tj->is_oopptr()->is_known_instance();
1326 
1327   // Process weird unsafe references.
1328   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
1329     assert(InlineUnsafeOps || StressReflectiveCode, "indeterminate pointers come only from unsafe ops");
1330     assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
1331     tj = TypeOopPtr::BOTTOM;
1332     ptr = tj->ptr();
1333     offset = tj->offset();
1334   }
1335 
1336   // Array pointers need some flattening
1337   const TypeAryPtr* ta = tj->isa_aryptr();
1338   if (ta && ta->is_stable()) {
1339     // Erase stability property for alias analysis.
1340     tj = ta = ta->cast_to_stable(false);
1341   }
1342   if( ta && is_known_inst ) {
1343     if ( offset != Type::OffsetBot &&
1344          offset > arrayOopDesc::length_offset_in_bytes() ) {
1345       offset = Type::OffsetBot; // Flatten constant access into array body only
1346       tj = ta = ta->
1347               remove_speculative()->
1348               cast_to_ptr_type(ptr)->
1349               with_offset(offset);
1350     }
1351   } else if (ta) {
1352     // For arrays indexed by constant indices, we flatten the alias
1353     // space to include all of the array body.  Only the header, klass
1354     // and array length can be accessed un-aliased.
1355     if( offset != Type::OffsetBot ) {
1356       if( ta->const_oop() ) { // MethodData* or Method*
1357         offset = Type::OffsetBot;   // Flatten constant access into array body
1358         tj = ta = ta->
1359                 remove_speculative()->
1360                 cast_to_ptr_type(ptr)->
1361                 cast_to_exactness(false)->
1362                 with_offset(offset);
1363       } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
1364         // range is OK as-is.
1365         tj = ta = TypeAryPtr::RANGE;
1366       } else if( offset == oopDesc::klass_offset_in_bytes() ) {
1367         tj = TypeInstPtr::KLASS; // all klass loads look alike
1368         ta = TypeAryPtr::RANGE; // generic ignored junk
1369         ptr = TypePtr::BotPTR;
1370       } else if( offset == oopDesc::mark_offset_in_bytes() ) {
1371         tj = TypeInstPtr::MARK;
1372         ta = TypeAryPtr::RANGE; // generic ignored junk
1373         ptr = TypePtr::BotPTR;
1374       } else {                  // Random constant offset into array body
1375         offset = Type::OffsetBot;   // Flatten constant access into array body
1376         tj = ta = ta->
1377                 remove_speculative()->
1378                 cast_to_ptr_type(ptr)->
1379                 cast_to_exactness(false)->
1380                 with_offset(offset);
1381       }
1382     }
1383     // Arrays of fixed size alias with arrays of unknown size.
1384     if (ta->size() != TypeInt::POS) {
1385       const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
1386       tj = ta = ta->
1387               remove_speculative()->
1388               cast_to_ptr_type(ptr)->
1389               with_ary(tary)->
1390               cast_to_exactness(false);
1391     }
1392     // Arrays of known objects become arrays of unknown objects.
1393     if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
1394       const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
1395       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,nullptr,false,offset);
1396     }
1397     if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
1398       const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
1399       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,nullptr,false,offset);
1400     }
1401     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
1402     // cannot be distinguished by bytecode alone.
1403     if (ta->elem() == TypeInt::BOOL) {
1404       const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
1405       ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
1406       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,offset);
1407     }
1408     // During the 2nd round of IterGVN, NotNull castings are removed.
1409     // Make sure the Bottom and NotNull variants alias the same.
1410     // Also, make sure exact and non-exact variants alias the same.
1411     if (ptr == TypePtr::NotNull || ta->klass_is_exact() || ta->speculative() != nullptr) {
1412       tj = ta = ta->
1413               remove_speculative()->
1414               cast_to_ptr_type(TypePtr::BotPTR)->
1415               cast_to_exactness(false)->
1416               with_offset(offset);
1417     }
1418   }
1419 
1420   // Oop pointers need some flattening
1421   const TypeInstPtr *to = tj->isa_instptr();
1422   if (to && to != TypeOopPtr::BOTTOM) {
1423     ciInstanceKlass* ik = to->instance_klass();
1424     if( ptr == TypePtr::Constant ) {
1425       if (ik != ciEnv::current()->Class_klass() ||
1426           offset < ik->layout_helper_size_in_bytes()) {
1427         // No constant oop pointers (such as Strings); they alias with
1428         // unknown strings.
1429         assert(!is_known_inst, "not scalarizable allocation");
1430         tj = to = to->
1431                 cast_to_instance_id(TypeOopPtr::InstanceBot)->
1432                 remove_speculative()->
1433                 cast_to_ptr_type(TypePtr::BotPTR)->
1434                 cast_to_exactness(false);
1435       }
1436     } else if( is_known_inst ) {
1437       tj = to; // Keep NotNull and klass_is_exact for instance type
1438     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
1439       // During the 2nd round of IterGVN, NotNull castings are removed.
1440       // Make sure the Bottom and NotNull variants alias the same.
1441       // Also, make sure exact and non-exact variants alias the same.
1442       tj = to = to->
1443               remove_speculative()->
1444               cast_to_instance_id(TypeOopPtr::InstanceBot)->
1445               cast_to_ptr_type(TypePtr::BotPTR)->
1446               cast_to_exactness(false);
1447     }
1448     if (to->speculative() != nullptr) {
1449       tj = to = to->remove_speculative();
1450     }
1451     // Canonicalize the holder of this field
1452     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
1453       // First handle header references such as a LoadKlassNode, even if the
1454       // object's klass is unloaded at compile time (4965979).
1455       if (!is_known_inst) { // Do it only for non-instance types
1456         tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, nullptr, offset);
1457       }
1458     } else if (offset < 0 || offset >= ik->layout_helper_size_in_bytes()) {
1459       // Static fields are in the space above the normal instance
1460       // fields in the java.lang.Class instance.
1461       if (ik != ciEnv::current()->Class_klass()) {
1462         to = nullptr;
1463         tj = TypeOopPtr::BOTTOM;
1464         offset = tj->offset();
1465       }
1466     } else {
1467       ciInstanceKlass *canonical_holder = ik->get_canonical_holder(offset);
1468       assert(offset < canonical_holder->layout_helper_size_in_bytes(), "");
1469       if (!ik->equals(canonical_holder) || tj->offset() != offset) {
1470         if( is_known_inst ) {
1471           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, true, nullptr, offset, to->instance_id());
1472         } else {
1473           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, false, nullptr, offset);
1474         }
1475       }
1476     }
1477   }
1478 
1479   // Klass pointers to object array klasses need some flattening
1480   const TypeKlassPtr *tk = tj->isa_klassptr();
1481   if( tk ) {
1482     // If we are referencing a field within a Klass, we need
1483     // to assume the worst case of an Object.  Both exact and
1484     // inexact types must flatten to the same alias class so
1485     // use NotNull as the PTR.
1486     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
1487       tj = tk = TypeInstKlassPtr::make(TypePtr::NotNull,
1488                                        env()->Object_klass(),
1489                                        offset);
1490     }
1491 
1492     if (tk->isa_aryklassptr() && tk->is_aryklassptr()->elem()->isa_klassptr()) {
1493       ciKlass* k = ciObjArrayKlass::make(env()->Object_klass());
1494       if (!k || !k->is_loaded()) {                  // Only fails for some -Xcomp runs
1495         tj = tk = TypeInstKlassPtr::make(TypePtr::NotNull, env()->Object_klass(), offset);
1496       } else {
1497         tj = tk = TypeAryKlassPtr::make(TypePtr::NotNull, tk->is_aryklassptr()->elem(), k, offset);
1498       }
1499     }
1500 
1501     // Check for precise loads from the primary supertype array and force them
1502     // to the supertype cache alias index.  Check for generic array loads from
1503     // the primary supertype array and also force them to the supertype cache
1504     // alias index.  Since the same load can reach both, we need to merge
1505     // these 2 disparate memories into the same alias class.  Since the
1506     // primary supertype array is read-only, there's no chance of confusion
1507     // where we bypass an array load and an array store.
1508     int primary_supers_offset = in_bytes(Klass::primary_supers_offset());
1509     if (offset == Type::OffsetBot ||
1510         (offset >= primary_supers_offset &&
1511          offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
1512         offset == (int)in_bytes(Klass::secondary_super_cache_offset())) {
1513       offset = in_bytes(Klass::secondary_super_cache_offset());
1514       tj = tk = tk->with_offset(offset);
1515     }
1516   }
1517 
1518   // Flatten all Raw pointers together.
1519   if (tj->base() == Type::RawPtr)
1520     tj = TypeRawPtr::BOTTOM;
1521 
1522   if (tj->base() == Type::AnyPtr)
1523     tj = TypePtr::BOTTOM;      // An error, which the caller must check for.
1524 
1525   offset = tj->offset();
1526   assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
1527 
1528   assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
1529           (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
1530           (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
1531           (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
1532           (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1533           (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1534           (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr),
1535           "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
1536   assert( tj->ptr() != TypePtr::TopPTR &&
1537           tj->ptr() != TypePtr::AnyNull &&
1538           tj->ptr() != TypePtr::Null, "No imprecise addresses" );
1539 //    assert( tj->ptr() != TypePtr::Constant ||
1540 //            tj->base() == Type::RawPtr ||
1541 //            tj->base() == Type::KlassPtr, "No constant oop addresses" );
1542 
1543   return tj;
1544 }
1545 
1546 void Compile::AliasType::Init(int i, const TypePtr* at) {
1547   assert(AliasIdxTop <= i && i < Compile::current()->_max_alias_types, "Invalid alias index");
1548   _index = i;
1549   _adr_type = at;
1550   _field = nullptr;
1551   _element = nullptr;
1552   _is_rewritable = true; // default
1553   const TypeOopPtr *atoop = (at != nullptr) ? at->isa_oopptr() : nullptr;
1554   if (atoop != nullptr && atoop->is_known_instance()) {
1555     const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
1556     _general_index = Compile::current()->get_alias_index(gt);
1557   } else {
1558     _general_index = 0;
1559   }
1560 }
1561 
1562 BasicType Compile::AliasType::basic_type() const {
1563   if (element() != nullptr) {
1564     const Type* element = adr_type()->is_aryptr()->elem();
1565     return element->isa_narrowoop() ? T_OBJECT : element->array_element_basic_type();
1566   } if (field() != nullptr) {
1567     return field()->layout_type();
1568   } else {
1569     return T_ILLEGAL; // unknown
1570   }
1571 }
1572 
1573 //---------------------------------print_on------------------------------------
1574 #ifndef PRODUCT
1575 void Compile::AliasType::print_on(outputStream* st) {
1576   if (index() < 10)
1577         st->print("@ <%d> ", index());
1578   else  st->print("@ <%d>",  index());
1579   st->print(is_rewritable() ? "   " : " RO");
1580   int offset = adr_type()->offset();
1581   if (offset == Type::OffsetBot)
1582         st->print(" +any");
1583   else  st->print(" +%-3d", offset);
1584   st->print(" in ");
1585   adr_type()->dump_on(st);
1586   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
1587   if (field() != nullptr && tjp) {
1588     if (tjp->is_instptr()->instance_klass()  != field()->holder() ||
1589         tjp->offset() != field()->offset_in_bytes()) {
1590       st->print(" != ");
1591       field()->print();
1592       st->print(" ***");
1593     }
1594   }
1595 }
1596 
1597 void print_alias_types() {
1598   Compile* C = Compile::current();
1599   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
1600   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
1601     C->alias_type(idx)->print_on(tty);
1602     tty->cr();
1603   }
1604 }
1605 #endif
1606 
1607 
1608 //----------------------------probe_alias_cache--------------------------------
1609 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
1610   intptr_t key = (intptr_t) adr_type;
1611   key ^= key >> logAliasCacheSize;
1612   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
1613 }
1614 
1615 
1616 //-----------------------------grow_alias_types--------------------------------
1617 void Compile::grow_alias_types() {
1618   const int old_ats  = _max_alias_types; // how many before?
1619   const int new_ats  = old_ats;          // how many more?
1620   const int grow_ats = old_ats+new_ats;  // how many now?
1621   _max_alias_types = grow_ats;
1622   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
1623   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
1624   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
1625   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
1626 }
1627 
1628 
1629 //--------------------------------find_alias_type------------------------------
1630 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field) {
1631   if (!do_aliasing()) {
1632     return alias_type(AliasIdxBot);
1633   }
1634 
1635   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1636   if (ace->_adr_type == adr_type) {
1637     return alias_type(ace->_index);
1638   }
1639 
1640   // Handle special cases.
1641   if (adr_type == nullptr)          return alias_type(AliasIdxTop);
1642   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
1643 
1644   // Do it the slow way.
1645   const TypePtr* flat = flatten_alias_type(adr_type);
1646 
1647 #ifdef ASSERT
1648   {
1649     ResourceMark rm;
1650     assert(flat == flatten_alias_type(flat), "not idempotent: adr_type = %s; flat = %s => %s",
1651            Type::str(adr_type), Type::str(flat), Type::str(flatten_alias_type(flat)));
1652     assert(flat != TypePtr::BOTTOM, "cannot alias-analyze an untyped ptr: adr_type = %s",
1653            Type::str(adr_type));
1654     if (flat->isa_oopptr() && !flat->isa_klassptr()) {
1655       const TypeOopPtr* foop = flat->is_oopptr();
1656       // Scalarizable allocations have exact klass always.
1657       bool exact = !foop->klass_is_exact() || foop->is_known_instance();
1658       const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
1659       assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type: foop = %s; xoop = %s",
1660              Type::str(foop), Type::str(xoop));
1661     }
1662   }
1663 #endif
1664 
1665   int idx = AliasIdxTop;
1666   for (int i = 0; i < num_alias_types(); i++) {
1667     if (alias_type(i)->adr_type() == flat) {
1668       idx = i;
1669       break;
1670     }
1671   }
1672 
1673   if (idx == AliasIdxTop) {
1674     if (no_create)  return nullptr;
1675     // Grow the array if necessary.
1676     if (_num_alias_types == _max_alias_types)  grow_alias_types();
1677     // Add a new alias type.
1678     idx = _num_alias_types++;
1679     _alias_types[idx]->Init(idx, flat);
1680     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
1681     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
1682     if (flat->isa_instptr()) {
1683       if (flat->offset() == java_lang_Class::klass_offset()
1684           && flat->is_instptr()->instance_klass() == env()->Class_klass())
1685         alias_type(idx)->set_rewritable(false);
1686     }
1687     if (flat->isa_aryptr()) {
1688 #ifdef ASSERT
1689       const int header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1690       // (T_BYTE has the weakest alignment and size restrictions...)
1691       assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
1692 #endif
1693       if (flat->offset() == TypePtr::OffsetBot) {
1694         alias_type(idx)->set_element(flat->is_aryptr()->elem());
1695       }
1696     }
1697     if (flat->isa_klassptr()) {
1698       if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
1699         alias_type(idx)->set_rewritable(false);
1700       if (flat->offset() == in_bytes(Klass::modifier_flags_offset()))
1701         alias_type(idx)->set_rewritable(false);
1702       if (flat->offset() == in_bytes(Klass::access_flags_offset()))
1703         alias_type(idx)->set_rewritable(false);
1704       if (flat->offset() == in_bytes(Klass::misc_flags_offset()))
1705         alias_type(idx)->set_rewritable(false);
1706       if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
1707         alias_type(idx)->set_rewritable(false);
1708       if (flat->offset() == in_bytes(Klass::secondary_super_cache_offset()))
1709         alias_type(idx)->set_rewritable(false);
1710     }
1711     // %%% (We would like to finalize JavaThread::threadObj_offset(),
1712     // but the base pointer type is not distinctive enough to identify
1713     // references into JavaThread.)
1714 
1715     // Check for final fields.
1716     const TypeInstPtr* tinst = flat->isa_instptr();
1717     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
1718       ciField* field;
1719       if (tinst->const_oop() != nullptr &&
1720           tinst->instance_klass() == ciEnv::current()->Class_klass() &&
1721           tinst->offset() >= (tinst->instance_klass()->layout_helper_size_in_bytes())) {
1722         // static field
1723         ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
1724         field = k->get_field_by_offset(tinst->offset(), true);
1725       } else {
1726         ciInstanceKlass *k = tinst->instance_klass();
1727         field = k->get_field_by_offset(tinst->offset(), false);
1728       }
1729       assert(field == nullptr ||
1730              original_field == nullptr ||
1731              (field->holder() == original_field->holder() &&
1732               field->offset_in_bytes() == original_field->offset_in_bytes() &&
1733               field->is_static() == original_field->is_static()), "wrong field?");
1734       // Set field() and is_rewritable() attributes.
1735       if (field != nullptr)  alias_type(idx)->set_field(field);
1736     }
1737   }
1738 
1739   // Fill the cache for next time.
1740   ace->_adr_type = adr_type;
1741   ace->_index    = idx;
1742   assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
1743 
1744   // Might as well try to fill the cache for the flattened version, too.
1745   AliasCacheEntry* face = probe_alias_cache(flat);
1746   if (face->_adr_type == nullptr) {
1747     face->_adr_type = flat;
1748     face->_index    = idx;
1749     assert(alias_type(flat) == alias_type(idx), "flat type must work too");
1750   }
1751 
1752   return alias_type(idx);
1753 }
1754 
1755 
1756 Compile::AliasType* Compile::alias_type(ciField* field) {
1757   const TypeOopPtr* t;
1758   if (field->is_static())
1759     t = TypeInstPtr::make(field->holder()->java_mirror());
1760   else
1761     t = TypeOopPtr::make_from_klass_raw(field->holder());
1762   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);
1763   assert((field->is_final() || field->is_stable()) == !atp->is_rewritable(), "must get the rewritable bits correct");
1764   return atp;
1765 }
1766 
1767 
1768 //------------------------------have_alias_type--------------------------------
1769 bool Compile::have_alias_type(const TypePtr* adr_type) {
1770   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1771   if (ace->_adr_type == adr_type) {
1772     return true;
1773   }
1774 
1775   // Handle special cases.
1776   if (adr_type == nullptr)             return true;
1777   if (adr_type == TypePtr::BOTTOM)  return true;
1778 
1779   return find_alias_type(adr_type, true, nullptr) != nullptr;
1780 }
1781 
1782 //-----------------------------must_alias--------------------------------------
1783 // True if all values of the given address type are in the given alias category.
1784 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
1785   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1786   if (adr_type == nullptr)              return true;  // null serves as TypePtr::TOP
1787   if (alias_idx == AliasIdxTop)         return false; // the empty category
1788   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
1789 
1790   // the only remaining possible overlap is identity
1791   int adr_idx = get_alias_index(adr_type);
1792   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1793   assert(adr_idx == alias_idx ||
1794          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
1795           && adr_type                       != TypeOopPtr::BOTTOM),
1796          "should not be testing for overlap with an unsafe pointer");
1797   return adr_idx == alias_idx;
1798 }
1799 
1800 //------------------------------can_alias--------------------------------------
1801 // True if any values of the given address type are in the given alias category.
1802 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
1803   if (alias_idx == AliasIdxTop)         return false; // the empty category
1804   if (adr_type == nullptr)              return false; // null serves as TypePtr::TOP
1805   // Known instance doesn't alias with bottom memory
1806   if (alias_idx == AliasIdxBot)         return !adr_type->is_known_instance();                   // the universal category
1807   if (adr_type->base() == Type::AnyPtr) return !C->get_adr_type(alias_idx)->is_known_instance(); // TypePtr::BOTTOM or its twins
1808 
1809   // the only remaining possible overlap is identity
1810   int adr_idx = get_alias_index(adr_type);
1811   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1812   return adr_idx == alias_idx;
1813 }
1814 
1815 // Mark all ParsePredicateNodes as useless. They will later be removed from the graph in IGVN together with their
1816 // uncommon traps if no Runtime Predicates were created from the Parse Predicates.
1817 void Compile::mark_parse_predicate_nodes_useless(PhaseIterGVN& igvn) {
1818   if (parse_predicate_count() == 0) {
1819     return;
1820   }
1821   for (int i = 0; i < parse_predicate_count(); i++) {
1822     ParsePredicateNode* parse_predicate = _parse_predicates.at(i);
1823     parse_predicate->mark_useless();
1824     igvn._worklist.push(parse_predicate);
1825   }
1826   _parse_predicates.clear();
1827 }
1828 
1829 void Compile::record_for_post_loop_opts_igvn(Node* n) {
1830   if (!n->for_post_loop_opts_igvn()) {
1831     assert(!_for_post_loop_igvn.contains(n), "duplicate");
1832     n->add_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
1833     _for_post_loop_igvn.append(n);
1834   }
1835 }
1836 
1837 void Compile::remove_from_post_loop_opts_igvn(Node* n) {
1838   n->remove_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
1839   _for_post_loop_igvn.remove(n);
1840 }
1841 
1842 void Compile::process_for_post_loop_opts_igvn(PhaseIterGVN& igvn) {
1843   // Verify that all previous optimizations produced a valid graph
1844   // at least to this point, even if no loop optimizations were done.
1845   PhaseIdealLoop::verify(igvn);
1846 
1847   C->set_post_loop_opts_phase(); // no more loop opts allowed
1848 
1849   assert(!C->major_progress(), "not cleared");
1850 
1851   if (_for_post_loop_igvn.length() > 0) {
1852     while (_for_post_loop_igvn.length() > 0) {
1853       Node* n = _for_post_loop_igvn.pop();
1854       n->remove_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
1855       igvn._worklist.push(n);
1856     }
1857     igvn.optimize();
1858     if (failing()) return;
1859     assert(_for_post_loop_igvn.length() == 0, "no more delayed nodes allowed");
1860     assert(C->parse_predicate_count() == 0, "all parse predicates should have been removed now");
1861 
1862     // Sometimes IGVN sets major progress (e.g., when processing loop nodes).
1863     if (C->major_progress()) {
1864       C->clear_major_progress(); // ensure that major progress is now clear
1865     }
1866   }
1867 }
1868 
1869 void Compile::record_unstable_if_trap(UnstableIfTrap* trap) {
1870   if (OptimizeUnstableIf) {
1871     _unstable_if_traps.append(trap);
1872   }
1873 }
1874 
1875 void Compile::remove_useless_unstable_if_traps(Unique_Node_List& useful) {
1876   for (int i = _unstable_if_traps.length() - 1; i >= 0; i--) {
1877     UnstableIfTrap* trap = _unstable_if_traps.at(i);
1878     Node* n = trap->uncommon_trap();
1879     if (!useful.member(n)) {
1880       _unstable_if_traps.delete_at(i); // replaces i-th with last element which is known to be useful (already processed)
1881     }
1882   }
1883 }
1884 
1885 // Remove the unstable if trap associated with 'unc' from candidates. It is either dead
1886 // or fold-compares case. Return true if succeed or not found.
1887 //
1888 // In rare cases, the found trap has been processed. It is too late to delete it. Return
1889 // false and ask fold-compares to yield.
1890 //
1891 // 'fold-compares' may use the uncommon_trap of the dominating IfNode to cover the fused
1892 // IfNode. This breaks the unstable_if trap invariant: control takes the unstable path
1893 // when deoptimization does happen.
1894 bool Compile::remove_unstable_if_trap(CallStaticJavaNode* unc, bool yield) {
1895   for (int i = 0; i < _unstable_if_traps.length(); ++i) {
1896     UnstableIfTrap* trap = _unstable_if_traps.at(i);
1897     if (trap->uncommon_trap() == unc) {
1898       if (yield && trap->modified()) {
1899         return false;
1900       }
1901       _unstable_if_traps.delete_at(i);
1902       break;
1903     }
1904   }
1905   return true;
1906 }
1907 
1908 // Re-calculate unstable_if traps with the liveness of next_bci, which points to the unlikely path.
1909 // It needs to be done after igvn because fold-compares may fuse uncommon_traps and before renumbering.
1910 void Compile::process_for_unstable_if_traps(PhaseIterGVN& igvn) {
1911   for (int i = _unstable_if_traps.length() - 1; i >= 0; --i) {
1912     UnstableIfTrap* trap = _unstable_if_traps.at(i);
1913     CallStaticJavaNode* unc = trap->uncommon_trap();
1914     int next_bci = trap->next_bci();
1915     bool modified = trap->modified();
1916 
1917     if (next_bci != -1 && !modified) {
1918       assert(!_dead_node_list.test(unc->_idx), "changing a dead node!");
1919       JVMState* jvms = unc->jvms();
1920       ciMethod* method = jvms->method();
1921       ciBytecodeStream iter(method);
1922 
1923       iter.force_bci(jvms->bci());
1924       assert(next_bci == iter.next_bci() || next_bci == iter.get_dest(), "wrong next_bci at unstable_if");
1925       Bytecodes::Code c = iter.cur_bc();
1926       Node* lhs = nullptr;
1927       Node* rhs = nullptr;
1928       if (c == Bytecodes::_if_acmpeq || c == Bytecodes::_if_acmpne) {
1929         lhs = unc->peek_operand(0);
1930         rhs = unc->peek_operand(1);
1931       } else if (c == Bytecodes::_ifnull || c == Bytecodes::_ifnonnull) {
1932         lhs = unc->peek_operand(0);
1933       }
1934 
1935       ResourceMark rm;
1936       const MethodLivenessResult& live_locals = method->liveness_at_bci(next_bci);
1937       assert(live_locals.is_valid(), "broken liveness info");
1938       int len = (int)live_locals.size();
1939 
1940       for (int i = 0; i < len; i++) {
1941         Node* local = unc->local(jvms, i);
1942         // kill local using the liveness of next_bci.
1943         // give up when the local looks like an operand to secure reexecution.
1944         if (!live_locals.at(i) && !local->is_top() && local != lhs && local!= rhs) {
1945           uint idx = jvms->locoff() + i;
1946 #ifdef ASSERT
1947           if (PrintOpto && Verbose) {
1948             tty->print("[unstable_if] kill local#%d: ", idx);
1949             local->dump();
1950             tty->cr();
1951           }
1952 #endif
1953           igvn.replace_input_of(unc, idx, top());
1954           modified = true;
1955         }
1956       }
1957     }
1958 
1959     // keep the mondified trap for late query
1960     if (modified) {
1961       trap->set_modified();
1962     } else {
1963       _unstable_if_traps.delete_at(i);
1964     }
1965   }
1966   igvn.optimize();
1967 }
1968 
1969 // StringOpts and late inlining of string methods
1970 void Compile::inline_string_calls(bool parse_time) {
1971   {
1972     // remove useless nodes to make the usage analysis simpler
1973     ResourceMark rm;
1974     PhaseRemoveUseless pru(initial_gvn(), *igvn_worklist());
1975   }
1976 
1977   {
1978     ResourceMark rm;
1979     print_method(PHASE_BEFORE_STRINGOPTS, 3);
1980     PhaseStringOpts pso(initial_gvn());
1981     print_method(PHASE_AFTER_STRINGOPTS, 3);
1982   }
1983 
1984   // now inline anything that we skipped the first time around
1985   if (!parse_time) {
1986     _late_inlines_pos = _late_inlines.length();
1987   }
1988 
1989   while (_string_late_inlines.length() > 0) {
1990     CallGenerator* cg = _string_late_inlines.pop();
1991     cg->do_late_inline();
1992     if (failing())  return;
1993   }
1994   _string_late_inlines.trunc_to(0);
1995 }
1996 
1997 // Late inlining of boxing methods
1998 void Compile::inline_boxing_calls(PhaseIterGVN& igvn) {
1999   if (_boxing_late_inlines.length() > 0) {
2000     assert(has_boxed_value(), "inconsistent");
2001 
2002     set_inlining_incrementally(true);
2003 
2004     igvn_worklist()->ensure_empty(); // should be done with igvn
2005 
2006     _late_inlines_pos = _late_inlines.length();
2007 
2008     while (_boxing_late_inlines.length() > 0) {
2009       CallGenerator* cg = _boxing_late_inlines.pop();
2010       cg->do_late_inline();
2011       if (failing())  return;
2012     }
2013     _boxing_late_inlines.trunc_to(0);
2014 
2015     inline_incrementally_cleanup(igvn);
2016 
2017     set_inlining_incrementally(false);
2018   }
2019 }
2020 
2021 bool Compile::inline_incrementally_one() {
2022   assert(IncrementalInline, "incremental inlining should be on");
2023 
2024   TracePhase tp("incrementalInline_inline", &timers[_t_incrInline_inline]);
2025 
2026   set_inlining_progress(false);
2027   set_do_cleanup(false);
2028 
2029   for (int i = 0; i < _late_inlines.length(); i++) {
2030     _late_inlines_pos = i+1;
2031     CallGenerator* cg = _late_inlines.at(i);
2032     bool does_dispatch = cg->is_virtual_late_inline() || cg->is_mh_late_inline();
2033     if (inlining_incrementally() || does_dispatch) { // a call can be either inlined or strength-reduced to a direct call
2034       cg->do_late_inline();
2035       assert(_late_inlines.at(i) == cg, "no insertions before current position allowed");
2036       if (failing()) {
2037         return false;
2038       } else if (inlining_progress()) {
2039         _late_inlines_pos = i+1; // restore the position in case new elements were inserted
2040         print_method(PHASE_INCREMENTAL_INLINE_STEP, 3, cg->call_node());
2041         break; // process one call site at a time
2042       }
2043     } else {
2044       // Ignore late inline direct calls when inlining is not allowed.
2045       // They are left in the late inline list when node budget is exhausted until the list is fully drained.
2046     }
2047   }
2048   // Remove processed elements.
2049   _late_inlines.remove_till(_late_inlines_pos);
2050   _late_inlines_pos = 0;
2051 
2052   assert(inlining_progress() || _late_inlines.length() == 0, "no progress");
2053 
2054   bool needs_cleanup = do_cleanup() || over_inlining_cutoff();
2055 
2056   set_inlining_progress(false);
2057   set_do_cleanup(false);
2058 
2059   bool force_cleanup = directive()->IncrementalInlineForceCleanupOption;
2060   return (_late_inlines.length() > 0) && !needs_cleanup && !force_cleanup;
2061 }
2062 
2063 void Compile::inline_incrementally_cleanup(PhaseIterGVN& igvn) {
2064   {
2065     TracePhase tp("incrementalInline_pru", &timers[_t_incrInline_pru]);
2066     ResourceMark rm;
2067     PhaseRemoveUseless pru(initial_gvn(), *igvn_worklist());
2068   }
2069   {
2070     TracePhase tp("incrementalInline_igvn", &timers[_t_incrInline_igvn]);
2071     igvn.reset_from_gvn(initial_gvn());
2072     igvn.optimize();
2073     if (failing()) return;
2074   }
2075   print_method(PHASE_INCREMENTAL_INLINE_CLEANUP, 3);
2076 }
2077 
2078 // Perform incremental inlining until bound on number of live nodes is reached
2079 void Compile::inline_incrementally(PhaseIterGVN& igvn) {
2080   TracePhase tp("incrementalInline", &timers[_t_incrInline]);
2081 
2082   set_inlining_incrementally(true);
2083   uint low_live_nodes = 0;
2084 
2085   while (_late_inlines.length() > 0) {
2086     if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2087       if (low_live_nodes < (uint)LiveNodeCountInliningCutoff * 8 / 10) {
2088         TracePhase tp("incrementalInline_ideal", &timers[_t_incrInline_ideal]);
2089         // PhaseIdealLoop is expensive so we only try it once we are
2090         // out of live nodes and we only try it again if the previous
2091         // helped got the number of nodes down significantly
2092         PhaseIdealLoop::optimize(igvn, LoopOptsNone);
2093         if (failing())  return;
2094         low_live_nodes = live_nodes();
2095         _major_progress = true;
2096       }
2097 
2098       if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2099         bool do_print_inlining = print_inlining() || print_intrinsics();
2100         if (do_print_inlining || log() != nullptr) {
2101           // Print inlining message for candidates that we couldn't inline for lack of space.
2102           for (int i = 0; i < _late_inlines.length(); i++) {
2103             CallGenerator* cg = _late_inlines.at(i);
2104             const char* msg = "live nodes > LiveNodeCountInliningCutoff";
2105             if (do_print_inlining) {
2106               cg->print_inlining_late(InliningResult::FAILURE, msg);
2107             }
2108             log_late_inline_failure(cg, msg);
2109           }
2110         }
2111         break; // finish
2112       }
2113     }
2114 
2115     igvn_worklist()->ensure_empty(); // should be done with igvn
2116 
2117     while (inline_incrementally_one()) {
2118       assert(!failing_internal() || failure_is_artificial(), "inconsistent");
2119     }
2120     if (failing())  return;
2121 
2122     inline_incrementally_cleanup(igvn);
2123 
2124     print_method(PHASE_INCREMENTAL_INLINE_STEP, 3);
2125 
2126     if (failing())  return;
2127 
2128     if (_late_inlines.length() == 0) {
2129       break; // no more progress
2130     }
2131   }
2132 
2133   igvn_worklist()->ensure_empty(); // should be done with igvn
2134 
2135   if (_string_late_inlines.length() > 0) {
2136     assert(has_stringbuilder(), "inconsistent");
2137 
2138     inline_string_calls(false);
2139 
2140     if (failing())  return;
2141 
2142     inline_incrementally_cleanup(igvn);
2143   }
2144 
2145   set_inlining_incrementally(false);
2146 }
2147 
2148 void Compile::process_late_inline_calls_no_inline(PhaseIterGVN& igvn) {
2149   // "inlining_incrementally() == false" is used to signal that no inlining is allowed
2150   // (see LateInlineVirtualCallGenerator::do_late_inline_check() for details).
2151   // Tracking and verification of modified nodes is disabled by setting "_modified_nodes == nullptr"
2152   // as if "inlining_incrementally() == true" were set.
2153   assert(inlining_incrementally() == false, "not allowed");
2154   assert(_modified_nodes == nullptr, "not allowed");
2155   assert(_late_inlines.length() > 0, "sanity");
2156 
2157   while (_late_inlines.length() > 0) {
2158     igvn_worklist()->ensure_empty(); // should be done with igvn
2159 
2160     while (inline_incrementally_one()) {
2161       assert(!failing_internal() || failure_is_artificial(), "inconsistent");
2162     }
2163     if (failing())  return;
2164 
2165     inline_incrementally_cleanup(igvn);
2166   }
2167 }
2168 
2169 bool Compile::optimize_loops(PhaseIterGVN& igvn, LoopOptsMode mode) {
2170   if (_loop_opts_cnt > 0) {
2171     while (major_progress() && (_loop_opts_cnt > 0)) {
2172       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2173       PhaseIdealLoop::optimize(igvn, mode);
2174       _loop_opts_cnt--;
2175       if (failing())  return false;
2176       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
2177     }
2178   }
2179   return true;
2180 }
2181 
2182 // Remove edges from "root" to each SafePoint at a backward branch.
2183 // They were inserted during parsing (see add_safepoint()) to make
2184 // infinite loops without calls or exceptions visible to root, i.e.,
2185 // useful.
2186 void Compile::remove_root_to_sfpts_edges(PhaseIterGVN& igvn) {
2187   Node *r = root();
2188   if (r != nullptr) {
2189     for (uint i = r->req(); i < r->len(); ++i) {
2190       Node *n = r->in(i);
2191       if (n != nullptr && n->is_SafePoint()) {
2192         r->rm_prec(i);
2193         if (n->outcnt() == 0) {
2194           igvn.remove_dead_node(n);
2195         }
2196         --i;
2197       }
2198     }
2199     // Parsing may have added top inputs to the root node (Path
2200     // leading to the Halt node proven dead). Make sure we get a
2201     // chance to clean them up.
2202     igvn._worklist.push(r);
2203     igvn.optimize();
2204   }
2205 }
2206 
2207 //------------------------------Optimize---------------------------------------
2208 // Given a graph, optimize it.
2209 void Compile::Optimize() {
2210   TracePhase tp("optimizer", &timers[_t_optimizer]);
2211 
2212 #ifndef PRODUCT
2213   if (env()->break_at_compile()) {
2214     BREAKPOINT;
2215   }
2216 
2217 #endif
2218 
2219   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
2220 #ifdef ASSERT
2221   bs->verify_gc_barriers(this, BarrierSetC2::BeforeOptimize);
2222 #endif
2223 
2224   ResourceMark rm;
2225 
2226   print_inlining_reinit();
2227 
2228   NOT_PRODUCT( verify_graph_edges(); )
2229 
2230   print_method(PHASE_AFTER_PARSING, 1);
2231 
2232  {
2233   // Iterative Global Value Numbering, including ideal transforms
2234   // Initialize IterGVN with types and values from parse-time GVN
2235   PhaseIterGVN igvn(initial_gvn());
2236 #ifdef ASSERT
2237   _modified_nodes = new (comp_arena()) Unique_Node_List(comp_arena());
2238 #endif
2239   {
2240     TracePhase tp("iterGVN", &timers[_t_iterGVN]);
2241     igvn.optimize();
2242   }
2243 
2244   if (failing())  return;
2245 
2246   print_method(PHASE_ITER_GVN1, 2);
2247 
2248   process_for_unstable_if_traps(igvn);
2249 
2250   if (failing())  return;
2251 
2252   inline_incrementally(igvn);
2253 
2254   print_method(PHASE_INCREMENTAL_INLINE, 2);
2255 
2256   if (failing())  return;
2257 
2258   if (eliminate_boxing()) {
2259     // Inline valueOf() methods now.
2260     inline_boxing_calls(igvn);
2261 
2262     if (failing())  return;
2263 
2264     if (AlwaysIncrementalInline || StressIncrementalInlining) {
2265       inline_incrementally(igvn);
2266     }
2267 
2268     print_method(PHASE_INCREMENTAL_BOXING_INLINE, 2);
2269 
2270     if (failing())  return;
2271   }
2272 
2273   // Remove the speculative part of types and clean up the graph from
2274   // the extra CastPP nodes whose only purpose is to carry them. Do
2275   // that early so that optimizations are not disrupted by the extra
2276   // CastPP nodes.
2277   remove_speculative_types(igvn);
2278 
2279   if (failing())  return;
2280 
2281   // No more new expensive nodes will be added to the list from here
2282   // so keep only the actual candidates for optimizations.
2283   cleanup_expensive_nodes(igvn);
2284 
2285   if (failing())  return;
2286 
2287   assert(EnableVectorSupport || !has_vbox_nodes(), "sanity");
2288   if (EnableVectorSupport && has_vbox_nodes()) {
2289     TracePhase tp("", &timers[_t_vector]);
2290     PhaseVector pv(igvn);
2291     pv.optimize_vector_boxes();
2292     if (failing())  return;
2293     print_method(PHASE_ITER_GVN_AFTER_VECTOR, 2);
2294   }
2295   assert(!has_vbox_nodes(), "sanity");
2296 
2297   if (!failing() && RenumberLiveNodes && live_nodes() + NodeLimitFudgeFactor < unique()) {
2298     Compile::TracePhase tp("", &timers[_t_renumberLive]);
2299     igvn_worklist()->ensure_empty(); // should be done with igvn
2300     {
2301       ResourceMark rm;
2302       PhaseRenumberLive prl(initial_gvn(), *igvn_worklist());
2303     }
2304     igvn.reset_from_gvn(initial_gvn());
2305     igvn.optimize();
2306     if (failing()) return;
2307   }
2308 
2309   // Now that all inlining is over and no PhaseRemoveUseless will run, cut edge from root to loop
2310   // safepoints
2311   remove_root_to_sfpts_edges(igvn);
2312 
2313   if (failing())  return;
2314 
2315   // Perform escape analysis
2316   if (do_escape_analysis() && ConnectionGraph::has_candidates(this)) {
2317     if (has_loops()) {
2318       // Cleanup graph (remove dead nodes).
2319       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2320       PhaseIdealLoop::optimize(igvn, LoopOptsMaxUnroll);
2321       if (failing())  return;
2322     }
2323     bool progress;
2324     print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
2325     do {
2326       ConnectionGraph::do_analysis(this, &igvn);
2327 
2328       if (failing())  return;
2329 
2330       int mcount = macro_count(); // Record number of allocations and locks before IGVN
2331 
2332       // Optimize out fields loads from scalar replaceable allocations.
2333       igvn.optimize();
2334       print_method(PHASE_ITER_GVN_AFTER_EA, 2);
2335 
2336       if (failing()) return;
2337 
2338       if (congraph() != nullptr && macro_count() > 0) {
2339         TracePhase tp("macroEliminate", &timers[_t_macroEliminate]);
2340         PhaseMacroExpand mexp(igvn);
2341         mexp.eliminate_macro_nodes();
2342         if (failing()) return;
2343 
2344         igvn.set_delay_transform(false);
2345         igvn.optimize();
2346         if (failing()) return;
2347 
2348         print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
2349       }
2350 
2351       ConnectionGraph::verify_ram_nodes(this, root());
2352       if (failing())  return;
2353 
2354       progress = do_iterative_escape_analysis() &&
2355                  (macro_count() < mcount) &&
2356                  ConnectionGraph::has_candidates(this);
2357       // Try again if candidates exist and made progress
2358       // by removing some allocations and/or locks.
2359     } while (progress);
2360   }
2361 
2362   // Loop transforms on the ideal graph.  Range Check Elimination,
2363   // peeling, unrolling, etc.
2364 
2365   // Set loop opts counter
2366   if((_loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
2367     {
2368       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2369       PhaseIdealLoop::optimize(igvn, LoopOptsDefault);
2370       _loop_opts_cnt--;
2371       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP1, 2);
2372       if (failing())  return;
2373     }
2374     // Loop opts pass if partial peeling occurred in previous pass
2375     if(PartialPeelLoop && major_progress() && (_loop_opts_cnt > 0)) {
2376       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2377       PhaseIdealLoop::optimize(igvn, LoopOptsSkipSplitIf);
2378       _loop_opts_cnt--;
2379       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP2, 2);
2380       if (failing())  return;
2381     }
2382     // Loop opts pass for loop-unrolling before CCP
2383     if(major_progress() && (_loop_opts_cnt > 0)) {
2384       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2385       PhaseIdealLoop::optimize(igvn, LoopOptsSkipSplitIf);
2386       _loop_opts_cnt--;
2387       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP3, 2);
2388     }
2389     if (!failing()) {
2390       // Verify that last round of loop opts produced a valid graph
2391       PhaseIdealLoop::verify(igvn);
2392     }
2393   }
2394   if (failing())  return;
2395 
2396   // Conditional Constant Propagation;
2397   print_method(PHASE_BEFORE_CCP1, 2);
2398   PhaseCCP ccp( &igvn );
2399   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
2400   {
2401     TracePhase tp("ccp", &timers[_t_ccp]);
2402     ccp.do_transform();
2403   }
2404   print_method(PHASE_CCP1, 2);
2405 
2406   assert( true, "Break here to ccp.dump_old2new_map()");
2407 
2408   // Iterative Global Value Numbering, including ideal transforms
2409   {
2410     TracePhase tp("iterGVN2", &timers[_t_iterGVN2]);
2411     igvn.reset_from_igvn(&ccp);
2412     igvn.optimize();
2413   }
2414   print_method(PHASE_ITER_GVN2, 2);
2415 
2416   if (failing())  return;
2417 
2418   // Loop transforms on the ideal graph.  Range Check Elimination,
2419   // peeling, unrolling, etc.
2420   if (!optimize_loops(igvn, LoopOptsDefault)) {
2421     return;
2422   }
2423 
2424   if (failing())  return;
2425 
2426   C->clear_major_progress(); // ensure that major progress is now clear
2427 
2428   process_for_post_loop_opts_igvn(igvn);
2429 
2430   if (failing())  return;
2431 
2432 #ifdef ASSERT
2433   bs->verify_gc_barriers(this, BarrierSetC2::BeforeMacroExpand);
2434 #endif
2435 
2436   {
2437     TracePhase tp("macroExpand", &timers[_t_macroExpand]);
2438     print_method(PHASE_BEFORE_MACRO_EXPANSION, 3);
2439     PhaseMacroExpand  mex(igvn);
2440     if (mex.expand_macro_nodes()) {
2441       assert(failing(), "must bail out w/ explicit message");
2442       return;
2443     }
2444     print_method(PHASE_AFTER_MACRO_EXPANSION, 2);
2445   }
2446 
2447   {
2448     TracePhase tp("barrierExpand", &timers[_t_barrierExpand]);
2449     if (bs->expand_barriers(this, igvn)) {
2450       assert(failing(), "must bail out w/ explicit message");
2451       return;
2452     }
2453     print_method(PHASE_BARRIER_EXPANSION, 2);
2454   }
2455 
2456   if (C->max_vector_size() > 0) {
2457     C->optimize_logic_cones(igvn);
2458     igvn.optimize();
2459     if (failing()) return;
2460   }
2461 
2462   DEBUG_ONLY( _modified_nodes = nullptr; )
2463 
2464   assert(igvn._worklist.size() == 0, "not empty");
2465 
2466   assert(_late_inlines.length() == 0 || IncrementalInlineMH || IncrementalInlineVirtual, "not empty");
2467 
2468   if (_late_inlines.length() > 0) {
2469     // More opportunities to optimize virtual and MH calls.
2470     // Though it's maybe too late to perform inlining, strength-reducing them to direct calls is still an option.
2471     process_late_inline_calls_no_inline(igvn);
2472     if (failing())  return;
2473   }
2474  } // (End scope of igvn; run destructor if necessary for asserts.)
2475 
2476  check_no_dead_use();
2477 
2478  process_print_inlining();
2479 
2480  // We will never use the NodeHash table any more. Clear it so that final_graph_reshaping does not have
2481  // to remove hashes to unlock nodes for modifications.
2482  C->node_hash()->clear();
2483 
2484  // A method with only infinite loops has no edges entering loops from root
2485  {
2486    TracePhase tp("graphReshape", &timers[_t_graphReshaping]);
2487    if (final_graph_reshaping()) {
2488      assert(failing(), "must bail out w/ explicit message");
2489      return;
2490    }
2491  }
2492 
2493  print_method(PHASE_OPTIMIZE_FINISHED, 2);
2494  DEBUG_ONLY(set_phase_optimize_finished();)
2495 }
2496 
2497 #ifdef ASSERT
2498 void Compile::check_no_dead_use() const {
2499   ResourceMark rm;
2500   Unique_Node_List wq;
2501   wq.push(root());
2502   for (uint i = 0; i < wq.size(); ++i) {
2503     Node* n = wq.at(i);
2504     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
2505       Node* u = n->fast_out(j);
2506       if (u->outcnt() == 0 && !u->is_Con()) {
2507         u->dump();
2508         fatal("no reachable node should have no use");
2509       }
2510       wq.push(u);
2511     }
2512   }
2513 }
2514 #endif
2515 
2516 void Compile::inline_vector_reboxing_calls() {
2517   if (C->_vector_reboxing_late_inlines.length() > 0) {
2518     _late_inlines_pos = C->_late_inlines.length();
2519     while (_vector_reboxing_late_inlines.length() > 0) {
2520       CallGenerator* cg = _vector_reboxing_late_inlines.pop();
2521       cg->do_late_inline();
2522       if (failing())  return;
2523       print_method(PHASE_INLINE_VECTOR_REBOX, 3, cg->call_node());
2524     }
2525     _vector_reboxing_late_inlines.trunc_to(0);
2526   }
2527 }
2528 
2529 bool Compile::has_vbox_nodes() {
2530   if (C->_vector_reboxing_late_inlines.length() > 0) {
2531     return true;
2532   }
2533   for (int macro_idx = C->macro_count() - 1; macro_idx >= 0; macro_idx--) {
2534     Node * n = C->macro_node(macro_idx);
2535     assert(n->is_macro(), "only macro nodes expected here");
2536     if (n->Opcode() == Op_VectorUnbox || n->Opcode() == Op_VectorBox || n->Opcode() == Op_VectorBoxAllocate) {
2537       return true;
2538     }
2539   }
2540   return false;
2541 }
2542 
2543 //---------------------------- Bitwise operation packing optimization ---------------------------
2544 
2545 static bool is_vector_unary_bitwise_op(Node* n) {
2546   return n->Opcode() == Op_XorV &&
2547          VectorNode::is_vector_bitwise_not_pattern(n);
2548 }
2549 
2550 static bool is_vector_binary_bitwise_op(Node* n) {
2551   switch (n->Opcode()) {
2552     case Op_AndV:
2553     case Op_OrV:
2554       return true;
2555 
2556     case Op_XorV:
2557       return !is_vector_unary_bitwise_op(n);
2558 
2559     default:
2560       return false;
2561   }
2562 }
2563 
2564 static bool is_vector_ternary_bitwise_op(Node* n) {
2565   return n->Opcode() == Op_MacroLogicV;
2566 }
2567 
2568 static bool is_vector_bitwise_op(Node* n) {
2569   return is_vector_unary_bitwise_op(n)  ||
2570          is_vector_binary_bitwise_op(n) ||
2571          is_vector_ternary_bitwise_op(n);
2572 }
2573 
2574 static bool is_vector_bitwise_cone_root(Node* n) {
2575   if (n->bottom_type()->isa_vectmask() || !is_vector_bitwise_op(n)) {
2576     return false;
2577   }
2578   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2579     if (is_vector_bitwise_op(n->fast_out(i))) {
2580       return false;
2581     }
2582   }
2583   return true;
2584 }
2585 
2586 static uint collect_unique_inputs(Node* n, Unique_Node_List& inputs) {
2587   uint cnt = 0;
2588   if (is_vector_bitwise_op(n)) {
2589     uint inp_cnt = n->is_predicated_vector() ? n->req()-1 : n->req();
2590     if (VectorNode::is_vector_bitwise_not_pattern(n)) {
2591       for (uint i = 1; i < inp_cnt; i++) {
2592         Node* in = n->in(i);
2593         bool skip = VectorNode::is_all_ones_vector(in);
2594         if (!skip && !inputs.member(in)) {
2595           inputs.push(in);
2596           cnt++;
2597         }
2598       }
2599       assert(cnt <= 1, "not unary");
2600     } else {
2601       uint last_req = inp_cnt;
2602       if (is_vector_ternary_bitwise_op(n)) {
2603         last_req = inp_cnt - 1; // skip last input
2604       }
2605       for (uint i = 1; i < last_req; i++) {
2606         Node* def = n->in(i);
2607         if (!inputs.member(def)) {
2608           inputs.push(def);
2609           cnt++;
2610         }
2611       }
2612     }
2613   } else { // not a bitwise operations
2614     if (!inputs.member(n)) {
2615       inputs.push(n);
2616       cnt++;
2617     }
2618   }
2619   return cnt;
2620 }
2621 
2622 void Compile::collect_logic_cone_roots(Unique_Node_List& list) {
2623   Unique_Node_List useful_nodes;
2624   C->identify_useful_nodes(useful_nodes);
2625 
2626   for (uint i = 0; i < useful_nodes.size(); i++) {
2627     Node* n = useful_nodes.at(i);
2628     if (is_vector_bitwise_cone_root(n)) {
2629       list.push(n);
2630     }
2631   }
2632 }
2633 
2634 Node* Compile::xform_to_MacroLogicV(PhaseIterGVN& igvn,
2635                                     const TypeVect* vt,
2636                                     Unique_Node_List& partition,
2637                                     Unique_Node_List& inputs) {
2638   assert(partition.size() == 2 || partition.size() == 3, "not supported");
2639   assert(inputs.size()    == 2 || inputs.size()    == 3, "not supported");
2640   assert(Matcher::match_rule_supported_vector(Op_MacroLogicV, vt->length(), vt->element_basic_type()), "not supported");
2641 
2642   Node* in1 = inputs.at(0);
2643   Node* in2 = inputs.at(1);
2644   Node* in3 = (inputs.size() == 3 ? inputs.at(2) : in2);
2645 
2646   uint func = compute_truth_table(partition, inputs);
2647 
2648   Node* pn = partition.at(partition.size() - 1);
2649   Node* mask = pn->is_predicated_vector() ? pn->in(pn->req()-1) : nullptr;
2650   return igvn.transform(MacroLogicVNode::make(igvn, in1, in2, in3, mask, func, vt));
2651 }
2652 
2653 static uint extract_bit(uint func, uint pos) {
2654   return (func & (1 << pos)) >> pos;
2655 }
2656 
2657 //
2658 //  A macro logic node represents a truth table. It has 4 inputs,
2659 //  First three inputs corresponds to 3 columns of a truth table
2660 //  and fourth input captures the logic function.
2661 //
2662 //  eg.  fn = (in1 AND in2) OR in3;
2663 //
2664 //      MacroNode(in1,in2,in3,fn)
2665 //
2666 //  -----------------
2667 //  in1 in2 in3  fn
2668 //  -----------------
2669 //  0    0   0    0
2670 //  0    0   1    1
2671 //  0    1   0    0
2672 //  0    1   1    1
2673 //  1    0   0    0
2674 //  1    0   1    1
2675 //  1    1   0    1
2676 //  1    1   1    1
2677 //
2678 
2679 uint Compile::eval_macro_logic_op(uint func, uint in1 , uint in2, uint in3) {
2680   int res = 0;
2681   for (int i = 0; i < 8; i++) {
2682     int bit1 = extract_bit(in1, i);
2683     int bit2 = extract_bit(in2, i);
2684     int bit3 = extract_bit(in3, i);
2685 
2686     int func_bit_pos = (bit1 << 2 | bit2 << 1 | bit3);
2687     int func_bit = extract_bit(func, func_bit_pos);
2688 
2689     res |= func_bit << i;
2690   }
2691   return res;
2692 }
2693 
2694 static uint eval_operand(Node* n, ResourceHashtable<Node*,uint>& eval_map) {
2695   assert(n != nullptr, "");
2696   assert(eval_map.contains(n), "absent");
2697   return *(eval_map.get(n));
2698 }
2699 
2700 static void eval_operands(Node* n,
2701                           uint& func1, uint& func2, uint& func3,
2702                           ResourceHashtable<Node*,uint>& eval_map) {
2703   assert(is_vector_bitwise_op(n), "");
2704 
2705   if (is_vector_unary_bitwise_op(n)) {
2706     Node* opnd = n->in(1);
2707     if (VectorNode::is_vector_bitwise_not_pattern(n) && VectorNode::is_all_ones_vector(opnd)) {
2708       opnd = n->in(2);
2709     }
2710     func1 = eval_operand(opnd, eval_map);
2711   } else if (is_vector_binary_bitwise_op(n)) {
2712     func1 = eval_operand(n->in(1), eval_map);
2713     func2 = eval_operand(n->in(2), eval_map);
2714   } else {
2715     assert(is_vector_ternary_bitwise_op(n), "unknown operation");
2716     func1 = eval_operand(n->in(1), eval_map);
2717     func2 = eval_operand(n->in(2), eval_map);
2718     func3 = eval_operand(n->in(3), eval_map);
2719   }
2720 }
2721 
2722 uint Compile::compute_truth_table(Unique_Node_List& partition, Unique_Node_List& inputs) {
2723   assert(inputs.size() <= 3, "sanity");
2724   ResourceMark rm;
2725   uint res = 0;
2726   ResourceHashtable<Node*,uint> eval_map;
2727 
2728   // Populate precomputed functions for inputs.
2729   // Each input corresponds to one column of 3 input truth-table.
2730   uint input_funcs[] = { 0xAA,   // (_, _, c) -> c
2731                          0xCC,   // (_, b, _) -> b
2732                          0xF0 }; // (a, _, _) -> a
2733   for (uint i = 0; i < inputs.size(); i++) {
2734     eval_map.put(inputs.at(i), input_funcs[2-i]);
2735   }
2736 
2737   for (uint i = 0; i < partition.size(); i++) {
2738     Node* n = partition.at(i);
2739 
2740     uint func1 = 0, func2 = 0, func3 = 0;
2741     eval_operands(n, func1, func2, func3, eval_map);
2742 
2743     switch (n->Opcode()) {
2744       case Op_OrV:
2745         assert(func3 == 0, "not binary");
2746         res = func1 | func2;
2747         break;
2748       case Op_AndV:
2749         assert(func3 == 0, "not binary");
2750         res = func1 & func2;
2751         break;
2752       case Op_XorV:
2753         if (VectorNode::is_vector_bitwise_not_pattern(n)) {
2754           assert(func2 == 0 && func3 == 0, "not unary");
2755           res = (~func1) & 0xFF;
2756         } else {
2757           assert(func3 == 0, "not binary");
2758           res = func1 ^ func2;
2759         }
2760         break;
2761       case Op_MacroLogicV:
2762         // Ordering of inputs may change during evaluation of sub-tree
2763         // containing MacroLogic node as a child node, thus a re-evaluation
2764         // makes sure that function is evaluated in context of current
2765         // inputs.
2766         res = eval_macro_logic_op(n->in(4)->get_int(), func1, func2, func3);
2767         break;
2768 
2769       default: assert(false, "not supported: %s", n->Name());
2770     }
2771     assert(res <= 0xFF, "invalid");
2772     eval_map.put(n, res);
2773   }
2774   return res;
2775 }
2776 
2777 // Criteria under which nodes gets packed into a macro logic node:-
2778 //  1) Parent and both child nodes are all unmasked or masked with
2779 //     same predicates.
2780 //  2) Masked parent can be packed with left child if it is predicated
2781 //     and both have same predicates.
2782 //  3) Masked parent can be packed with right child if its un-predicated
2783 //     or has matching predication condition.
2784 //  4) An unmasked parent can be packed with an unmasked child.
2785 bool Compile::compute_logic_cone(Node* n, Unique_Node_List& partition, Unique_Node_List& inputs) {
2786   assert(partition.size() == 0, "not empty");
2787   assert(inputs.size() == 0, "not empty");
2788   if (is_vector_ternary_bitwise_op(n)) {
2789     return false;
2790   }
2791 
2792   bool is_unary_op = is_vector_unary_bitwise_op(n);
2793   if (is_unary_op) {
2794     assert(collect_unique_inputs(n, inputs) == 1, "not unary");
2795     return false; // too few inputs
2796   }
2797 
2798   bool pack_left_child = true;
2799   bool pack_right_child = true;
2800 
2801   bool left_child_LOP = is_vector_bitwise_op(n->in(1));
2802   bool right_child_LOP = is_vector_bitwise_op(n->in(2));
2803 
2804   int left_child_input_cnt = 0;
2805   int right_child_input_cnt = 0;
2806 
2807   bool parent_is_predicated = n->is_predicated_vector();
2808   bool left_child_predicated = n->in(1)->is_predicated_vector();
2809   bool right_child_predicated = n->in(2)->is_predicated_vector();
2810 
2811   Node* parent_pred = parent_is_predicated ? n->in(n->req()-1) : nullptr;
2812   Node* left_child_pred = left_child_predicated ? n->in(1)->in(n->in(1)->req()-1) : nullptr;
2813   Node* right_child_pred = right_child_predicated ? n->in(1)->in(n->in(1)->req()-1) : nullptr;
2814 
2815   do {
2816     if (pack_left_child && left_child_LOP &&
2817         ((!parent_is_predicated && !left_child_predicated) ||
2818         ((parent_is_predicated && left_child_predicated &&
2819           parent_pred == left_child_pred)))) {
2820        partition.push(n->in(1));
2821        left_child_input_cnt = collect_unique_inputs(n->in(1), inputs);
2822     } else {
2823        inputs.push(n->in(1));
2824        left_child_input_cnt = 1;
2825     }
2826 
2827     if (pack_right_child && right_child_LOP &&
2828         (!right_child_predicated ||
2829          (right_child_predicated && parent_is_predicated &&
2830           parent_pred == right_child_pred))) {
2831        partition.push(n->in(2));
2832        right_child_input_cnt = collect_unique_inputs(n->in(2), inputs);
2833     } else {
2834        inputs.push(n->in(2));
2835        right_child_input_cnt = 1;
2836     }
2837 
2838     if (inputs.size() > 3) {
2839       assert(partition.size() > 0, "");
2840       inputs.clear();
2841       partition.clear();
2842       if (left_child_input_cnt > right_child_input_cnt) {
2843         pack_left_child = false;
2844       } else {
2845         pack_right_child = false;
2846       }
2847     } else {
2848       break;
2849     }
2850   } while(true);
2851 
2852   if(partition.size()) {
2853     partition.push(n);
2854   }
2855 
2856   return (partition.size() == 2 || partition.size() == 3) &&
2857          (inputs.size()    == 2 || inputs.size()    == 3);
2858 }
2859 
2860 void Compile::process_logic_cone_root(PhaseIterGVN &igvn, Node *n, VectorSet &visited) {
2861   assert(is_vector_bitwise_op(n), "not a root");
2862 
2863   visited.set(n->_idx);
2864 
2865   // 1) Do a DFS walk over the logic cone.
2866   for (uint i = 1; i < n->req(); i++) {
2867     Node* in = n->in(i);
2868     if (!visited.test(in->_idx) && is_vector_bitwise_op(in)) {
2869       process_logic_cone_root(igvn, in, visited);
2870     }
2871   }
2872 
2873   // 2) Bottom up traversal: Merge node[s] with
2874   // the parent to form macro logic node.
2875   Unique_Node_List partition;
2876   Unique_Node_List inputs;
2877   if (compute_logic_cone(n, partition, inputs)) {
2878     const TypeVect* vt = n->bottom_type()->is_vect();
2879     Node* pn = partition.at(partition.size() - 1);
2880     Node* mask = pn->is_predicated_vector() ? pn->in(pn->req()-1) : nullptr;
2881     if (mask == nullptr ||
2882         Matcher::match_rule_supported_vector_masked(Op_MacroLogicV, vt->length(), vt->element_basic_type())) {
2883       Node* macro_logic = xform_to_MacroLogicV(igvn, vt, partition, inputs);
2884       VectorNode::trace_new_vector(macro_logic, "MacroLogic");
2885       igvn.replace_node(n, macro_logic);
2886     }
2887   }
2888 }
2889 
2890 void Compile::optimize_logic_cones(PhaseIterGVN &igvn) {
2891   ResourceMark rm;
2892   if (Matcher::match_rule_supported(Op_MacroLogicV)) {
2893     Unique_Node_List list;
2894     collect_logic_cone_roots(list);
2895 
2896     while (list.size() > 0) {
2897       Node* n = list.pop();
2898       const TypeVect* vt = n->bottom_type()->is_vect();
2899       bool supported = Matcher::match_rule_supported_vector(Op_MacroLogicV, vt->length(), vt->element_basic_type());
2900       if (supported) {
2901         VectorSet visited(comp_arena());
2902         process_logic_cone_root(igvn, n, visited);
2903       }
2904     }
2905   }
2906 }
2907 
2908 //------------------------------Code_Gen---------------------------------------
2909 // Given a graph, generate code for it
2910 void Compile::Code_Gen() {
2911   if (failing()) {
2912     return;
2913   }
2914 
2915   // Perform instruction selection.  You might think we could reclaim Matcher
2916   // memory PDQ, but actually the Matcher is used in generating spill code.
2917   // Internals of the Matcher (including some VectorSets) must remain live
2918   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
2919   // set a bit in reclaimed memory.
2920 
2921   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2922   // nodes.  Mapping is only valid at the root of each matched subtree.
2923   NOT_PRODUCT( verify_graph_edges(); )
2924 
2925   Matcher matcher;
2926   _matcher = &matcher;
2927   {
2928     TracePhase tp("matcher", &timers[_t_matcher]);
2929     matcher.match();
2930     if (failing()) {
2931       return;
2932     }
2933   }
2934   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2935   // nodes.  Mapping is only valid at the root of each matched subtree.
2936   NOT_PRODUCT( verify_graph_edges(); )
2937 
2938   // If you have too many nodes, or if matching has failed, bail out
2939   check_node_count(0, "out of nodes matching instructions");
2940   if (failing()) {
2941     return;
2942   }
2943 
2944   print_method(PHASE_MATCHING, 2);
2945 
2946   // Build a proper-looking CFG
2947   PhaseCFG cfg(node_arena(), root(), matcher);
2948   if (failing()) {
2949     return;
2950   }
2951   _cfg = &cfg;
2952   {
2953     TracePhase tp("scheduler", &timers[_t_scheduler]);
2954     bool success = cfg.do_global_code_motion();
2955     if (!success) {
2956       return;
2957     }
2958 
2959     print_method(PHASE_GLOBAL_CODE_MOTION, 2);
2960     NOT_PRODUCT( verify_graph_edges(); )
2961     cfg.verify();
2962   }
2963 
2964   PhaseChaitin regalloc(unique(), cfg, matcher, false);
2965   _regalloc = &regalloc;
2966   {
2967     TracePhase tp("regalloc", &timers[_t_registerAllocation]);
2968     // Perform register allocation.  After Chaitin, use-def chains are
2969     // no longer accurate (at spill code) and so must be ignored.
2970     // Node->LRG->reg mappings are still accurate.
2971     _regalloc->Register_Allocate();
2972 
2973     // Bail out if the allocator builds too many nodes
2974     if (failing()) {
2975       return;
2976     }
2977 
2978     print_method(PHASE_REGISTER_ALLOCATION, 2);
2979   }
2980 
2981   // Prior to register allocation we kept empty basic blocks in case the
2982   // the allocator needed a place to spill.  After register allocation we
2983   // are not adding any new instructions.  If any basic block is empty, we
2984   // can now safely remove it.
2985   {
2986     TracePhase tp("blockOrdering", &timers[_t_blockOrdering]);
2987     cfg.remove_empty_blocks();
2988     if (do_freq_based_layout()) {
2989       PhaseBlockLayout layout(cfg);
2990     } else {
2991       cfg.set_loop_alignment();
2992     }
2993     cfg.fixup_flow();
2994     cfg.remove_unreachable_blocks();
2995     cfg.verify_dominator_tree();
2996     print_method(PHASE_BLOCK_ORDERING, 3);
2997   }
2998 
2999   // Apply peephole optimizations
3000   if( OptoPeephole ) {
3001     TracePhase tp("peephole", &timers[_t_peephole]);
3002     PhasePeephole peep( _regalloc, cfg);
3003     peep.do_transform();
3004     print_method(PHASE_PEEPHOLE, 3);
3005   }
3006 
3007   // Do late expand if CPU requires this.
3008   if (Matcher::require_postalloc_expand) {
3009     TracePhase tp("postalloc_expand", &timers[_t_postalloc_expand]);
3010     cfg.postalloc_expand(_regalloc);
3011     print_method(PHASE_POSTALLOC_EXPAND, 3);
3012   }
3013 
3014   // Convert Nodes to instruction bits in a buffer
3015   {
3016     TracePhase tp("output", &timers[_t_output]);
3017     PhaseOutput output;
3018     output.Output();
3019     if (failing())  return;
3020     output.install();
3021     print_method(PHASE_FINAL_CODE, 1); // Compile::_output is not null here
3022   }
3023 
3024   // He's dead, Jim.
3025   _cfg     = (PhaseCFG*)((intptr_t)0xdeadbeef);
3026   _regalloc = (PhaseChaitin*)((intptr_t)0xdeadbeef);
3027 }
3028 
3029 //------------------------------Final_Reshape_Counts---------------------------
3030 // This class defines counters to help identify when a method
3031 // may/must be executed using hardware with only 24-bit precision.
3032 struct Final_Reshape_Counts : public StackObj {
3033   int  _call_count;             // count non-inlined 'common' calls
3034   int  _float_count;            // count float ops requiring 24-bit precision
3035   int  _double_count;           // count double ops requiring more precision
3036   int  _java_call_count;        // count non-inlined 'java' calls
3037   int  _inner_loop_count;       // count loops which need alignment
3038   VectorSet _visited;           // Visitation flags
3039   Node_List _tests;             // Set of IfNodes & PCTableNodes
3040 
3041   Final_Reshape_Counts() :
3042     _call_count(0), _float_count(0), _double_count(0),
3043     _java_call_count(0), _inner_loop_count(0) { }
3044 
3045   void inc_call_count  () { _call_count  ++; }
3046   void inc_float_count () { _float_count ++; }
3047   void inc_double_count() { _double_count++; }
3048   void inc_java_call_count() { _java_call_count++; }
3049   void inc_inner_loop_count() { _inner_loop_count++; }
3050 
3051   int  get_call_count  () const { return _call_count  ; }
3052   int  get_float_count () const { return _float_count ; }
3053   int  get_double_count() const { return _double_count; }
3054   int  get_java_call_count() const { return _java_call_count; }
3055   int  get_inner_loop_count() const { return _inner_loop_count; }
3056 };
3057 
3058 // Eliminate trivially redundant StoreCMs and accumulate their
3059 // precedence edges.
3060 void Compile::eliminate_redundant_card_marks(Node* n) {
3061   assert(n->Opcode() == Op_StoreCM, "expected StoreCM");
3062   if (n->in(MemNode::Address)->outcnt() > 1) {
3063     // There are multiple users of the same address so it might be
3064     // possible to eliminate some of the StoreCMs
3065     Node* mem = n->in(MemNode::Memory);
3066     Node* adr = n->in(MemNode::Address);
3067     Node* val = n->in(MemNode::ValueIn);
3068     Node* prev = n;
3069     bool done = false;
3070     // Walk the chain of StoreCMs eliminating ones that match.  As
3071     // long as it's a chain of single users then the optimization is
3072     // safe.  Eliminating partially redundant StoreCMs would require
3073     // cloning copies down the other paths.
3074     while (mem->Opcode() == Op_StoreCM && mem->outcnt() == 1 && !done) {
3075       if (adr == mem->in(MemNode::Address) &&
3076           val == mem->in(MemNode::ValueIn)) {
3077         // redundant StoreCM
3078         if (mem->req() > MemNode::OopStore) {
3079           // Hasn't been processed by this code yet.
3080           n->add_prec(mem->in(MemNode::OopStore));
3081         } else {
3082           // Already converted to precedence edge
3083           for (uint i = mem->req(); i < mem->len(); i++) {
3084             // Accumulate any precedence edges
3085             if (mem->in(i) != nullptr) {
3086               n->add_prec(mem->in(i));
3087             }
3088           }
3089           // Everything above this point has been processed.
3090           done = true;
3091         }
3092         // Eliminate the previous StoreCM
3093         prev->set_req(MemNode::Memory, mem->in(MemNode::Memory));
3094         assert(mem->outcnt() == 0, "should be dead");
3095         mem->disconnect_inputs(this);
3096       } else {
3097         prev = mem;
3098       }
3099       mem = prev->in(MemNode::Memory);
3100     }
3101   }
3102 }
3103 
3104 //------------------------------final_graph_reshaping_impl----------------------
3105 // Implement items 1-5 from final_graph_reshaping below.
3106 void Compile::final_graph_reshaping_impl(Node *n, Final_Reshape_Counts& frc, Unique_Node_List& dead_nodes) {
3107 
3108   if ( n->outcnt() == 0 ) return; // dead node
3109   uint nop = n->Opcode();
3110 
3111   // Check for 2-input instruction with "last use" on right input.
3112   // Swap to left input.  Implements item (2).
3113   if( n->req() == 3 &&          // two-input instruction
3114       n->in(1)->outcnt() > 1 && // left use is NOT a last use
3115       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
3116       n->in(2)->outcnt() == 1 &&// right use IS a last use
3117       !n->in(2)->is_Con() ) {   // right use is not a constant
3118     // Check for commutative opcode
3119     switch( nop ) {
3120     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddL:
3121     case Op_MaxI:  case Op_MaxL:  case Op_MaxF:  case Op_MaxD:
3122     case Op_MinI:  case Op_MinL:  case Op_MinF:  case Op_MinD:
3123     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulL:
3124     case Op_AndL:  case Op_XorL:  case Op_OrL:
3125     case Op_AndI:  case Op_XorI:  case Op_OrI: {
3126       // Move "last use" input to left by swapping inputs
3127       n->swap_edges(1, 2);
3128       break;
3129     }
3130     default:
3131       break;
3132     }
3133   }
3134 
3135 #ifdef ASSERT
3136   if( n->is_Mem() ) {
3137     int alias_idx = get_alias_index(n->as_Mem()->adr_type());
3138     assert( n->in(0) != nullptr || alias_idx != Compile::AliasIdxRaw ||
3139             // oop will be recorded in oop map if load crosses safepoint
3140             (n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
3141                               LoadNode::is_immutable_value(n->in(MemNode::Address)))),
3142             "raw memory operations should have control edge");
3143   }
3144   if (n->is_MemBar()) {
3145     MemBarNode* mb = n->as_MemBar();
3146     if (mb->trailing_store() || mb->trailing_load_store()) {
3147       assert(mb->leading_membar()->trailing_membar() == mb, "bad membar pair");
3148       Node* mem = BarrierSet::barrier_set()->barrier_set_c2()->step_over_gc_barrier(mb->in(MemBarNode::Precedent));
3149       assert((mb->trailing_store() && mem->is_Store() && mem->as_Store()->is_release()) ||
3150              (mb->trailing_load_store() && mem->is_LoadStore()), "missing mem op");
3151     } else if (mb->leading()) {
3152       assert(mb->trailing_membar()->leading_membar() == mb, "bad membar pair");
3153     }
3154   }
3155 #endif
3156   // Count FPU ops and common calls, implements item (3)
3157   bool gc_handled = BarrierSet::barrier_set()->barrier_set_c2()->final_graph_reshaping(this, n, nop, dead_nodes);
3158   if (!gc_handled) {
3159     final_graph_reshaping_main_switch(n, frc, nop, dead_nodes);
3160   }
3161 
3162   // Collect CFG split points
3163   if (n->is_MultiBranch() && !n->is_RangeCheck()) {
3164     frc._tests.push(n);
3165   }
3166 }
3167 
3168 void Compile::handle_div_mod_op(Node* n, BasicType bt, bool is_unsigned) {
3169   if (!UseDivMod) {
3170     return;
3171   }
3172 
3173   // Check if "a % b" and "a / b" both exist
3174   Node* d = n->find_similar(Op_DivIL(bt, is_unsigned));
3175   if (d == nullptr) {
3176     return;
3177   }
3178 
3179   // Replace them with a fused divmod if supported
3180   if (Matcher::has_match_rule(Op_DivModIL(bt, is_unsigned))) {
3181     DivModNode* divmod = DivModNode::make(n, bt, is_unsigned);
3182     d->subsume_by(divmod->div_proj(), this);
3183     n->subsume_by(divmod->mod_proj(), this);
3184   } else {
3185     // Replace "a % b" with "a - ((a / b) * b)"
3186     Node* mult = MulNode::make(d, d->in(2), bt);
3187     Node* sub = SubNode::make(d->in(1), mult, bt);
3188     n->subsume_by(sub, this);
3189   }
3190 }
3191 
3192 void Compile::final_graph_reshaping_main_switch(Node* n, Final_Reshape_Counts& frc, uint nop, Unique_Node_List& dead_nodes) {
3193   switch( nop ) {
3194   // Count all float operations that may use FPU
3195   case Op_AddF:
3196   case Op_SubF:
3197   case Op_MulF:
3198   case Op_DivF:
3199   case Op_NegF:
3200   case Op_ModF:
3201   case Op_ConvI2F:
3202   case Op_ConF:
3203   case Op_CmpF:
3204   case Op_CmpF3:
3205   case Op_StoreF:
3206   case Op_LoadF:
3207   // case Op_ConvL2F: // longs are split into 32-bit halves
3208     frc.inc_float_count();
3209     break;
3210 
3211   case Op_ConvF2D:
3212   case Op_ConvD2F:
3213     frc.inc_float_count();
3214     frc.inc_double_count();
3215     break;
3216 
3217   // Count all double operations that may use FPU
3218   case Op_AddD:
3219   case Op_SubD:
3220   case Op_MulD:
3221   case Op_DivD:
3222   case Op_NegD:
3223   case Op_ModD:
3224   case Op_ConvI2D:
3225   case Op_ConvD2I:
3226   // case Op_ConvL2D: // handled by leaf call
3227   // case Op_ConvD2L: // handled by leaf call
3228   case Op_ConD:
3229   case Op_CmpD:
3230   case Op_CmpD3:
3231   case Op_StoreD:
3232   case Op_LoadD:
3233   case Op_LoadD_unaligned:
3234     frc.inc_double_count();
3235     break;
3236   case Op_Opaque1:              // Remove Opaque Nodes before matching
3237     n->subsume_by(n->in(1), this);
3238     break;
3239   case Op_CallStaticJava:
3240   case Op_CallJava:
3241   case Op_CallDynamicJava:
3242     frc.inc_java_call_count(); // Count java call site;
3243   case Op_CallRuntime:
3244   case Op_CallLeaf:
3245   case Op_CallLeafVector:
3246   case Op_CallLeafNoFP: {
3247     assert (n->is_Call(), "");
3248     CallNode *call = n->as_Call();
3249     // Count call sites where the FP mode bit would have to be flipped.
3250     // Do not count uncommon runtime calls:
3251     // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
3252     // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
3253     if (!call->is_CallStaticJava() || !call->as_CallStaticJava()->_name) {
3254       frc.inc_call_count();   // Count the call site
3255     } else {                  // See if uncommon argument is shared
3256       Node *n = call->in(TypeFunc::Parms);
3257       int nop = n->Opcode();
3258       // Clone shared simple arguments to uncommon calls, item (1).
3259       if (n->outcnt() > 1 &&
3260           !n->is_Proj() &&
3261           nop != Op_CreateEx &&
3262           nop != Op_CheckCastPP &&
3263           nop != Op_DecodeN &&
3264           nop != Op_DecodeNKlass &&
3265           !n->is_Mem() &&
3266           !n->is_Phi()) {
3267         Node *x = n->clone();
3268         call->set_req(TypeFunc::Parms, x);
3269       }
3270     }
3271     break;
3272   }
3273 
3274   case Op_StoreCM:
3275     {
3276       // Convert OopStore dependence into precedence edge
3277       Node* prec = n->in(MemNode::OopStore);
3278       n->del_req(MemNode::OopStore);
3279       n->add_prec(prec);
3280       eliminate_redundant_card_marks(n);
3281     }
3282 
3283     // fall through
3284 
3285   case Op_StoreB:
3286   case Op_StoreC:
3287   case Op_StoreI:
3288   case Op_StoreL:
3289   case Op_CompareAndSwapB:
3290   case Op_CompareAndSwapS:
3291   case Op_CompareAndSwapI:
3292   case Op_CompareAndSwapL:
3293   case Op_CompareAndSwapP:
3294   case Op_CompareAndSwapN:
3295   case Op_WeakCompareAndSwapB:
3296   case Op_WeakCompareAndSwapS:
3297   case Op_WeakCompareAndSwapI:
3298   case Op_WeakCompareAndSwapL:
3299   case Op_WeakCompareAndSwapP:
3300   case Op_WeakCompareAndSwapN:
3301   case Op_CompareAndExchangeB:
3302   case Op_CompareAndExchangeS:
3303   case Op_CompareAndExchangeI:
3304   case Op_CompareAndExchangeL:
3305   case Op_CompareAndExchangeP:
3306   case Op_CompareAndExchangeN:
3307   case Op_GetAndAddS:
3308   case Op_GetAndAddB:
3309   case Op_GetAndAddI:
3310   case Op_GetAndAddL:
3311   case Op_GetAndSetS:
3312   case Op_GetAndSetB:
3313   case Op_GetAndSetI:
3314   case Op_GetAndSetL:
3315   case Op_GetAndSetP:
3316   case Op_GetAndSetN:
3317   case Op_StoreP:
3318   case Op_StoreN:
3319   case Op_StoreNKlass:
3320   case Op_LoadB:
3321   case Op_LoadUB:
3322   case Op_LoadUS:
3323   case Op_LoadI:
3324   case Op_LoadKlass:
3325   case Op_LoadNKlass:
3326   case Op_LoadL:
3327   case Op_LoadL_unaligned:
3328   case Op_LoadP:
3329   case Op_LoadN:
3330   case Op_LoadRange:
3331   case Op_LoadS:
3332     break;
3333 
3334   case Op_AddP: {               // Assert sane base pointers
3335     Node *addp = n->in(AddPNode::Address);
3336     assert( !addp->is_AddP() ||
3337             addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
3338             addp->in(AddPNode::Base) == n->in(AddPNode::Base),
3339             "Base pointers must match (addp %u)", addp->_idx );
3340 #ifdef _LP64
3341     if ((UseCompressedOops || UseCompressedClassPointers) &&
3342         addp->Opcode() == Op_ConP &&
3343         addp == n->in(AddPNode::Base) &&
3344         n->in(AddPNode::Offset)->is_Con()) {
3345       // If the transformation of ConP to ConN+DecodeN is beneficial depends
3346       // on the platform and on the compressed oops mode.
3347       // Use addressing with narrow klass to load with offset on x86.
3348       // Some platforms can use the constant pool to load ConP.
3349       // Do this transformation here since IGVN will convert ConN back to ConP.
3350       const Type* t = addp->bottom_type();
3351       bool is_oop   = t->isa_oopptr() != nullptr;
3352       bool is_klass = t->isa_klassptr() != nullptr;
3353 
3354       if ((is_oop   && UseCompressedOops          && Matcher::const_oop_prefer_decode()  ) ||
3355           (is_klass && UseCompressedClassPointers && Matcher::const_klass_prefer_decode() &&
3356            t->isa_klassptr()->exact_klass()->is_in_encoding_range())) {
3357         Node* nn = nullptr;
3358 
3359         int op = is_oop ? Op_ConN : Op_ConNKlass;
3360 
3361         // Look for existing ConN node of the same exact type.
3362         Node* r  = root();
3363         uint cnt = r->outcnt();
3364         for (uint i = 0; i < cnt; i++) {
3365           Node* m = r->raw_out(i);
3366           if (m!= nullptr && m->Opcode() == op &&
3367               m->bottom_type()->make_ptr() == t) {
3368             nn = m;
3369             break;
3370           }
3371         }
3372         if (nn != nullptr) {
3373           // Decode a narrow oop to match address
3374           // [R12 + narrow_oop_reg<<3 + offset]
3375           if (is_oop) {
3376             nn = new DecodeNNode(nn, t);
3377           } else {
3378             nn = new DecodeNKlassNode(nn, t);
3379           }
3380           // Check for succeeding AddP which uses the same Base.
3381           // Otherwise we will run into the assertion above when visiting that guy.
3382           for (uint i = 0; i < n->outcnt(); ++i) {
3383             Node *out_i = n->raw_out(i);
3384             if (out_i && out_i->is_AddP() && out_i->in(AddPNode::Base) == addp) {
3385               out_i->set_req(AddPNode::Base, nn);
3386 #ifdef ASSERT
3387               for (uint j = 0; j < out_i->outcnt(); ++j) {
3388                 Node *out_j = out_i->raw_out(j);
3389                 assert(out_j == nullptr || !out_j->is_AddP() || out_j->in(AddPNode::Base) != addp,
3390                        "more than 2 AddP nodes in a chain (out_j %u)", out_j->_idx);
3391               }
3392 #endif
3393             }
3394           }
3395           n->set_req(AddPNode::Base, nn);
3396           n->set_req(AddPNode::Address, nn);
3397           if (addp->outcnt() == 0) {
3398             addp->disconnect_inputs(this);
3399           }
3400         }
3401       }
3402     }
3403 #endif
3404     break;
3405   }
3406 
3407   case Op_CastPP: {
3408     // Remove CastPP nodes to gain more freedom during scheduling but
3409     // keep the dependency they encode as control or precedence edges
3410     // (if control is set already) on memory operations. Some CastPP
3411     // nodes don't have a control (don't carry a dependency): skip
3412     // those.
3413     if (n->in(0) != nullptr) {
3414       ResourceMark rm;
3415       Unique_Node_List wq;
3416       wq.push(n);
3417       for (uint next = 0; next < wq.size(); ++next) {
3418         Node *m = wq.at(next);
3419         for (DUIterator_Fast imax, i = m->fast_outs(imax); i < imax; i++) {
3420           Node* use = m->fast_out(i);
3421           if (use->is_Mem() || use->is_EncodeNarrowPtr()) {
3422             use->ensure_control_or_add_prec(n->in(0));
3423           } else {
3424             switch(use->Opcode()) {
3425             case Op_AddP:
3426             case Op_DecodeN:
3427             case Op_DecodeNKlass:
3428             case Op_CheckCastPP:
3429             case Op_CastPP:
3430               wq.push(use);
3431               break;
3432             }
3433           }
3434         }
3435       }
3436     }
3437     const bool is_LP64 = LP64_ONLY(true) NOT_LP64(false);
3438     if (is_LP64 && n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
3439       Node* in1 = n->in(1);
3440       const Type* t = n->bottom_type();
3441       Node* new_in1 = in1->clone();
3442       new_in1->as_DecodeN()->set_type(t);
3443 
3444       if (!Matcher::narrow_oop_use_complex_address()) {
3445         //
3446         // x86, ARM and friends can handle 2 adds in addressing mode
3447         // and Matcher can fold a DecodeN node into address by using
3448         // a narrow oop directly and do implicit null check in address:
3449         //
3450         // [R12 + narrow_oop_reg<<3 + offset]
3451         // NullCheck narrow_oop_reg
3452         //
3453         // On other platforms (Sparc) we have to keep new DecodeN node and
3454         // use it to do implicit null check in address:
3455         //
3456         // decode_not_null narrow_oop_reg, base_reg
3457         // [base_reg + offset]
3458         // NullCheck base_reg
3459         //
3460         // Pin the new DecodeN node to non-null path on these platform (Sparc)
3461         // to keep the information to which null check the new DecodeN node
3462         // corresponds to use it as value in implicit_null_check().
3463         //
3464         new_in1->set_req(0, n->in(0));
3465       }
3466 
3467       n->subsume_by(new_in1, this);
3468       if (in1->outcnt() == 0) {
3469         in1->disconnect_inputs(this);
3470       }
3471     } else {
3472       n->subsume_by(n->in(1), this);
3473       if (n->outcnt() == 0) {
3474         n->disconnect_inputs(this);
3475       }
3476     }
3477     break;
3478   }
3479 #ifdef _LP64
3480   case Op_CmpP:
3481     // Do this transformation here to preserve CmpPNode::sub() and
3482     // other TypePtr related Ideal optimizations (for example, ptr nullness).
3483     if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
3484       Node* in1 = n->in(1);
3485       Node* in2 = n->in(2);
3486       if (!in1->is_DecodeNarrowPtr()) {
3487         in2 = in1;
3488         in1 = n->in(2);
3489       }
3490       assert(in1->is_DecodeNarrowPtr(), "sanity");
3491 
3492       Node* new_in2 = nullptr;
3493       if (in2->is_DecodeNarrowPtr()) {
3494         assert(in2->Opcode() == in1->Opcode(), "must be same node type");
3495         new_in2 = in2->in(1);
3496       } else if (in2->Opcode() == Op_ConP) {
3497         const Type* t = in2->bottom_type();
3498         if (t == TypePtr::NULL_PTR) {
3499           assert(in1->is_DecodeN(), "compare klass to null?");
3500           // Don't convert CmpP null check into CmpN if compressed
3501           // oops implicit null check is not generated.
3502           // This will allow to generate normal oop implicit null check.
3503           if (Matcher::gen_narrow_oop_implicit_null_checks())
3504             new_in2 = ConNode::make(TypeNarrowOop::NULL_PTR);
3505           //
3506           // This transformation together with CastPP transformation above
3507           // will generated code for implicit null checks for compressed oops.
3508           //
3509           // The original code after Optimize()
3510           //
3511           //    LoadN memory, narrow_oop_reg
3512           //    decode narrow_oop_reg, base_reg
3513           //    CmpP base_reg, nullptr
3514           //    CastPP base_reg // NotNull
3515           //    Load [base_reg + offset], val_reg
3516           //
3517           // after these transformations will be
3518           //
3519           //    LoadN memory, narrow_oop_reg
3520           //    CmpN narrow_oop_reg, nullptr
3521           //    decode_not_null narrow_oop_reg, base_reg
3522           //    Load [base_reg + offset], val_reg
3523           //
3524           // and the uncommon path (== nullptr) will use narrow_oop_reg directly
3525           // since narrow oops can be used in debug info now (see the code in
3526           // final_graph_reshaping_walk()).
3527           //
3528           // At the end the code will be matched to
3529           // on x86:
3530           //
3531           //    Load_narrow_oop memory, narrow_oop_reg
3532           //    Load [R12 + narrow_oop_reg<<3 + offset], val_reg
3533           //    NullCheck narrow_oop_reg
3534           //
3535           // and on sparc:
3536           //
3537           //    Load_narrow_oop memory, narrow_oop_reg
3538           //    decode_not_null narrow_oop_reg, base_reg
3539           //    Load [base_reg + offset], val_reg
3540           //    NullCheck base_reg
3541           //
3542         } else if (t->isa_oopptr()) {
3543           new_in2 = ConNode::make(t->make_narrowoop());
3544         } else if (t->isa_klassptr()) {
3545           new_in2 = ConNode::make(t->make_narrowklass());
3546         }
3547       }
3548       if (new_in2 != nullptr) {
3549         Node* cmpN = new CmpNNode(in1->in(1), new_in2);
3550         n->subsume_by(cmpN, this);
3551         if (in1->outcnt() == 0) {
3552           in1->disconnect_inputs(this);
3553         }
3554         if (in2->outcnt() == 0) {
3555           in2->disconnect_inputs(this);
3556         }
3557       }
3558     }
3559     break;
3560 
3561   case Op_DecodeN:
3562   case Op_DecodeNKlass:
3563     assert(!n->in(1)->is_EncodeNarrowPtr(), "should be optimized out");
3564     // DecodeN could be pinned when it can't be fold into
3565     // an address expression, see the code for Op_CastPP above.
3566     assert(n->in(0) == nullptr || (UseCompressedOops && !Matcher::narrow_oop_use_complex_address()), "no control");
3567     break;
3568 
3569   case Op_EncodeP:
3570   case Op_EncodePKlass: {
3571     Node* in1 = n->in(1);
3572     if (in1->is_DecodeNarrowPtr()) {
3573       n->subsume_by(in1->in(1), this);
3574     } else if (in1->Opcode() == Op_ConP) {
3575       const Type* t = in1->bottom_type();
3576       if (t == TypePtr::NULL_PTR) {
3577         assert(t->isa_oopptr(), "null klass?");
3578         n->subsume_by(ConNode::make(TypeNarrowOop::NULL_PTR), this);
3579       } else if (t->isa_oopptr()) {
3580         n->subsume_by(ConNode::make(t->make_narrowoop()), this);
3581       } else if (t->isa_klassptr()) {
3582         n->subsume_by(ConNode::make(t->make_narrowklass()), this);
3583       }
3584     }
3585     if (in1->outcnt() == 0) {
3586       in1->disconnect_inputs(this);
3587     }
3588     break;
3589   }
3590 
3591   case Op_Proj: {
3592     if (OptimizeStringConcat || IncrementalInline) {
3593       ProjNode* proj = n->as_Proj();
3594       if (proj->_is_io_use) {
3595         assert(proj->_con == TypeFunc::I_O || proj->_con == TypeFunc::Memory, "");
3596         // Separate projections were used for the exception path which
3597         // are normally removed by a late inline.  If it wasn't inlined
3598         // then they will hang around and should just be replaced with
3599         // the original one. Merge them.
3600         Node* non_io_proj = proj->in(0)->as_Multi()->proj_out_or_null(proj->_con, false /*is_io_use*/);
3601         if (non_io_proj  != nullptr) {
3602           proj->subsume_by(non_io_proj , this);
3603         }
3604       }
3605     }
3606     break;
3607   }
3608 
3609   case Op_Phi:
3610     if (n->as_Phi()->bottom_type()->isa_narrowoop() || n->as_Phi()->bottom_type()->isa_narrowklass()) {
3611       // The EncodeP optimization may create Phi with the same edges
3612       // for all paths. It is not handled well by Register Allocator.
3613       Node* unique_in = n->in(1);
3614       assert(unique_in != nullptr, "");
3615       uint cnt = n->req();
3616       for (uint i = 2; i < cnt; i++) {
3617         Node* m = n->in(i);
3618         assert(m != nullptr, "");
3619         if (unique_in != m)
3620           unique_in = nullptr;
3621       }
3622       if (unique_in != nullptr) {
3623         n->subsume_by(unique_in, this);
3624       }
3625     }
3626     break;
3627 
3628 #endif
3629 
3630 #ifdef ASSERT
3631   case Op_CastII:
3632     // Verify that all range check dependent CastII nodes were removed.
3633     if (n->isa_CastII()->has_range_check()) {
3634       n->dump(3);
3635       assert(false, "Range check dependent CastII node was not removed");
3636     }
3637     break;
3638 #endif
3639 
3640   case Op_ModI:
3641     handle_div_mod_op(n, T_INT, false);
3642     break;
3643 
3644   case Op_ModL:
3645     handle_div_mod_op(n, T_LONG, false);
3646     break;
3647 
3648   case Op_UModI:
3649     handle_div_mod_op(n, T_INT, true);
3650     break;
3651 
3652   case Op_UModL:
3653     handle_div_mod_op(n, T_LONG, true);
3654     break;
3655 
3656   case Op_LoadVector:
3657   case Op_StoreVector:
3658 #ifdef ASSERT
3659     // Add VerifyVectorAlignment node between adr and load / store.
3660     if (VerifyAlignVector && Matcher::has_match_rule(Op_VerifyVectorAlignment)) {
3661       bool must_verify_alignment = n->is_LoadVector() ? n->as_LoadVector()->must_verify_alignment() :
3662                                                         n->as_StoreVector()->must_verify_alignment();
3663       if (must_verify_alignment) {
3664         jlong vector_width = n->is_LoadVector() ? n->as_LoadVector()->memory_size() :
3665                                                   n->as_StoreVector()->memory_size();
3666         // The memory access should be aligned to the vector width in bytes.
3667         // However, the underlying array is possibly less well aligned, but at least
3668         // to ObjectAlignmentInBytes. Hence, even if multiple arrays are accessed in
3669         // a loop we can expect at least the following alignment:
3670         jlong guaranteed_alignment = MIN2(vector_width, (jlong)ObjectAlignmentInBytes);
3671         assert(2 <= guaranteed_alignment && guaranteed_alignment <= 64, "alignment must be in range");
3672         assert(is_power_of_2(guaranteed_alignment), "alignment must be power of 2");
3673         // Create mask from alignment. e.g. 0b1000 -> 0b0111
3674         jlong mask = guaranteed_alignment - 1;
3675         Node* mask_con = ConLNode::make(mask);
3676         VerifyVectorAlignmentNode* va = new VerifyVectorAlignmentNode(n->in(MemNode::Address), mask_con);
3677         n->set_req(MemNode::Address, va);
3678       }
3679     }
3680 #endif
3681     break;
3682 
3683   case Op_LoadVectorGather:
3684   case Op_StoreVectorScatter:
3685   case Op_LoadVectorGatherMasked:
3686   case Op_StoreVectorScatterMasked:
3687   case Op_VectorCmpMasked:
3688   case Op_VectorMaskGen:
3689   case Op_LoadVectorMasked:
3690   case Op_StoreVectorMasked:
3691     break;
3692 
3693   case Op_AddReductionVI:
3694   case Op_AddReductionVL:
3695   case Op_AddReductionVF:
3696   case Op_AddReductionVD:
3697   case Op_MulReductionVI:
3698   case Op_MulReductionVL:
3699   case Op_MulReductionVF:
3700   case Op_MulReductionVD:
3701   case Op_MinReductionV:
3702   case Op_MaxReductionV:
3703   case Op_AndReductionV:
3704   case Op_OrReductionV:
3705   case Op_XorReductionV:
3706     break;
3707 
3708   case Op_PackB:
3709   case Op_PackS:
3710   case Op_PackI:
3711   case Op_PackF:
3712   case Op_PackL:
3713   case Op_PackD:
3714     if (n->req()-1 > 2) {
3715       // Replace many operand PackNodes with a binary tree for matching
3716       PackNode* p = (PackNode*) n;
3717       Node* btp = p->binary_tree_pack(1, n->req());
3718       n->subsume_by(btp, this);
3719     }
3720     break;
3721   case Op_Loop:
3722     assert(!n->as_Loop()->is_loop_nest_inner_loop() || _loop_opts_cnt == 0, "should have been turned into a counted loop");
3723   case Op_CountedLoop:
3724   case Op_LongCountedLoop:
3725   case Op_OuterStripMinedLoop:
3726     if (n->as_Loop()->is_inner_loop()) {
3727       frc.inc_inner_loop_count();
3728     }
3729     n->as_Loop()->verify_strip_mined(0);
3730     break;
3731   case Op_LShiftI:
3732   case Op_RShiftI:
3733   case Op_URShiftI:
3734   case Op_LShiftL:
3735   case Op_RShiftL:
3736   case Op_URShiftL:
3737     if (Matcher::need_masked_shift_count) {
3738       // The cpu's shift instructions don't restrict the count to the
3739       // lower 5/6 bits. We need to do the masking ourselves.
3740       Node* in2 = n->in(2);
3741       juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
3742       const TypeInt* t = in2->find_int_type();
3743       if (t != nullptr && t->is_con()) {
3744         juint shift = t->get_con();
3745         if (shift > mask) { // Unsigned cmp
3746           n->set_req(2, ConNode::make(TypeInt::make(shift & mask)));
3747         }
3748       } else {
3749         if (t == nullptr || t->_lo < 0 || t->_hi > (int)mask) {
3750           Node* shift = new AndINode(in2, ConNode::make(TypeInt::make(mask)));
3751           n->set_req(2, shift);
3752         }
3753       }
3754       if (in2->outcnt() == 0) { // Remove dead node
3755         in2->disconnect_inputs(this);
3756       }
3757     }
3758     break;
3759   case Op_MemBarStoreStore:
3760   case Op_MemBarRelease:
3761     // Break the link with AllocateNode: it is no longer useful and
3762     // confuses register allocation.
3763     if (n->req() > MemBarNode::Precedent) {
3764       n->set_req(MemBarNode::Precedent, top());
3765     }
3766     break;
3767   case Op_MemBarAcquire: {
3768     if (n->as_MemBar()->trailing_load() && n->req() > MemBarNode::Precedent) {
3769       // At parse time, the trailing MemBarAcquire for a volatile load
3770       // is created with an edge to the load. After optimizations,
3771       // that input may be a chain of Phis. If those phis have no
3772       // other use, then the MemBarAcquire keeps them alive and
3773       // register allocation can be confused.
3774       dead_nodes.push(n->in(MemBarNode::Precedent));
3775       n->set_req(MemBarNode::Precedent, top());
3776     }
3777     break;
3778   }
3779   case Op_Blackhole:
3780     break;
3781   case Op_RangeCheck: {
3782     RangeCheckNode* rc = n->as_RangeCheck();
3783     Node* iff = new IfNode(rc->in(0), rc->in(1), rc->_prob, rc->_fcnt);
3784     n->subsume_by(iff, this);
3785     frc._tests.push(iff);
3786     break;
3787   }
3788   case Op_ConvI2L: {
3789     if (!Matcher::convi2l_type_required) {
3790       // Code generation on some platforms doesn't need accurate
3791       // ConvI2L types. Widening the type can help remove redundant
3792       // address computations.
3793       n->as_Type()->set_type(TypeLong::INT);
3794       ResourceMark rm;
3795       Unique_Node_List wq;
3796       wq.push(n);
3797       for (uint next = 0; next < wq.size(); next++) {
3798         Node *m = wq.at(next);
3799 
3800         for(;;) {
3801           // Loop over all nodes with identical inputs edges as m
3802           Node* k = m->find_similar(m->Opcode());
3803           if (k == nullptr) {
3804             break;
3805           }
3806           // Push their uses so we get a chance to remove node made
3807           // redundant
3808           for (DUIterator_Fast imax, i = k->fast_outs(imax); i < imax; i++) {
3809             Node* u = k->fast_out(i);
3810             if (u->Opcode() == Op_LShiftL ||
3811                 u->Opcode() == Op_AddL ||
3812                 u->Opcode() == Op_SubL ||
3813                 u->Opcode() == Op_AddP) {
3814               wq.push(u);
3815             }
3816           }
3817           // Replace all nodes with identical edges as m with m
3818           k->subsume_by(m, this);
3819         }
3820       }
3821     }
3822     break;
3823   }
3824   case Op_CmpUL: {
3825     if (!Matcher::has_match_rule(Op_CmpUL)) {
3826       // No support for unsigned long comparisons
3827       ConINode* sign_pos = new ConINode(TypeInt::make(BitsPerLong - 1));
3828       Node* sign_bit_mask = new RShiftLNode(n->in(1), sign_pos);
3829       Node* orl = new OrLNode(n->in(1), sign_bit_mask);
3830       ConLNode* remove_sign_mask = new ConLNode(TypeLong::make(max_jlong));
3831       Node* andl = new AndLNode(orl, remove_sign_mask);
3832       Node* cmp = new CmpLNode(andl, n->in(2));
3833       n->subsume_by(cmp, this);
3834     }
3835     break;
3836   }
3837   default:
3838     assert(!n->is_Call(), "");
3839     assert(!n->is_Mem(), "");
3840     assert(nop != Op_ProfileBoolean, "should be eliminated during IGVN");
3841     break;
3842   }
3843 }
3844 
3845 //------------------------------final_graph_reshaping_walk---------------------
3846 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
3847 // requires that the walk visits a node's inputs before visiting the node.
3848 void Compile::final_graph_reshaping_walk(Node_Stack& nstack, Node* root, Final_Reshape_Counts& frc, Unique_Node_List& dead_nodes) {
3849   Unique_Node_List sfpt;
3850 
3851   frc._visited.set(root->_idx); // first, mark node as visited
3852   uint cnt = root->req();
3853   Node *n = root;
3854   uint  i = 0;
3855   while (true) {
3856     if (i < cnt) {
3857       // Place all non-visited non-null inputs onto stack
3858       Node* m = n->in(i);
3859       ++i;
3860       if (m != nullptr && !frc._visited.test_set(m->_idx)) {
3861         if (m->is_SafePoint() && m->as_SafePoint()->jvms() != nullptr) {
3862           // compute worst case interpreter size in case of a deoptimization
3863           update_interpreter_frame_size(m->as_SafePoint()->jvms()->interpreter_frame_size());
3864 
3865           sfpt.push(m);
3866         }
3867         cnt = m->req();
3868         nstack.push(n, i); // put on stack parent and next input's index
3869         n = m;
3870         i = 0;
3871       }
3872     } else {
3873       // Now do post-visit work
3874       final_graph_reshaping_impl(n, frc, dead_nodes);
3875       if (nstack.is_empty())
3876         break;             // finished
3877       n = nstack.node();   // Get node from stack
3878       cnt = n->req();
3879       i = nstack.index();
3880       nstack.pop();        // Shift to the next node on stack
3881     }
3882   }
3883 
3884   // Skip next transformation if compressed oops are not used.
3885   if ((UseCompressedOops && !Matcher::gen_narrow_oop_implicit_null_checks()) ||
3886       (!UseCompressedOops && !UseCompressedClassPointers))
3887     return;
3888 
3889   // Go over safepoints nodes to skip DecodeN/DecodeNKlass nodes for debug edges.
3890   // It could be done for an uncommon traps or any safepoints/calls
3891   // if the DecodeN/DecodeNKlass node is referenced only in a debug info.
3892   while (sfpt.size() > 0) {
3893     n = sfpt.pop();
3894     JVMState *jvms = n->as_SafePoint()->jvms();
3895     assert(jvms != nullptr, "sanity");
3896     int start = jvms->debug_start();
3897     int end   = n->req();
3898     bool is_uncommon = (n->is_CallStaticJava() &&
3899                         n->as_CallStaticJava()->uncommon_trap_request() != 0);
3900     for (int j = start; j < end; j++) {
3901       Node* in = n->in(j);
3902       if (in->is_DecodeNarrowPtr()) {
3903         bool safe_to_skip = true;
3904         if (!is_uncommon ) {
3905           // Is it safe to skip?
3906           for (uint i = 0; i < in->outcnt(); i++) {
3907             Node* u = in->raw_out(i);
3908             if (!u->is_SafePoint() ||
3909                 (u->is_Call() && u->as_Call()->has_non_debug_use(n))) {
3910               safe_to_skip = false;
3911             }
3912           }
3913         }
3914         if (safe_to_skip) {
3915           n->set_req(j, in->in(1));
3916         }
3917         if (in->outcnt() == 0) {
3918           in->disconnect_inputs(this);
3919         }
3920       }
3921     }
3922   }
3923 }
3924 
3925 //------------------------------final_graph_reshaping--------------------------
3926 // Final Graph Reshaping.
3927 //
3928 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
3929 //     and not commoned up and forced early.  Must come after regular
3930 //     optimizations to avoid GVN undoing the cloning.  Clone constant
3931 //     inputs to Loop Phis; these will be split by the allocator anyways.
3932 //     Remove Opaque nodes.
3933 // (2) Move last-uses by commutative operations to the left input to encourage
3934 //     Intel update-in-place two-address operations and better register usage
3935 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
3936 //     calls canonicalizing them back.
3937 // (3) Count the number of double-precision FP ops, single-precision FP ops
3938 //     and call sites.  On Intel, we can get correct rounding either by
3939 //     forcing singles to memory (requires extra stores and loads after each
3940 //     FP bytecode) or we can set a rounding mode bit (requires setting and
3941 //     clearing the mode bit around call sites).  The mode bit is only used
3942 //     if the relative frequency of single FP ops to calls is low enough.
3943 //     This is a key transform for SPEC mpeg_audio.
3944 // (4) Detect infinite loops; blobs of code reachable from above but not
3945 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
3946 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
3947 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
3948 //     Detection is by looking for IfNodes where only 1 projection is
3949 //     reachable from below or CatchNodes missing some targets.
3950 // (5) Assert for insane oop offsets in debug mode.
3951 
3952 bool Compile::final_graph_reshaping() {
3953   // an infinite loop may have been eliminated by the optimizer,
3954   // in which case the graph will be empty.
3955   if (root()->req() == 1) {
3956     // Do not compile method that is only a trivial infinite loop,
3957     // since the content of the loop may have been eliminated.
3958     record_method_not_compilable("trivial infinite loop");
3959     return true;
3960   }
3961 
3962   // Expensive nodes have their control input set to prevent the GVN
3963   // from freely commoning them. There's no GVN beyond this point so
3964   // no need to keep the control input. We want the expensive nodes to
3965   // be freely moved to the least frequent code path by gcm.
3966   assert(OptimizeExpensiveOps || expensive_count() == 0, "optimization off but list non empty?");
3967   for (int i = 0; i < expensive_count(); i++) {
3968     _expensive_nodes.at(i)->set_req(0, nullptr);
3969   }
3970 
3971   Final_Reshape_Counts frc;
3972 
3973   // Visit everybody reachable!
3974   // Allocate stack of size C->live_nodes()/2 to avoid frequent realloc
3975   Node_Stack nstack(live_nodes() >> 1);
3976   Unique_Node_List dead_nodes;
3977   final_graph_reshaping_walk(nstack, root(), frc, dead_nodes);
3978 
3979   // Check for unreachable (from below) code (i.e., infinite loops).
3980   for( uint i = 0; i < frc._tests.size(); i++ ) {
3981     MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
3982     // Get number of CFG targets.
3983     // Note that PCTables include exception targets after calls.
3984     uint required_outcnt = n->required_outcnt();
3985     if (n->outcnt() != required_outcnt) {
3986       // Check for a few special cases.  Rethrow Nodes never take the
3987       // 'fall-thru' path, so expected kids is 1 less.
3988       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
3989         if (n->in(0)->in(0)->is_Call()) {
3990           CallNode* call = n->in(0)->in(0)->as_Call();
3991           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
3992             required_outcnt--;      // Rethrow always has 1 less kid
3993           } else if (call->req() > TypeFunc::Parms &&
3994                      call->is_CallDynamicJava()) {
3995             // Check for null receiver. In such case, the optimizer has
3996             // detected that the virtual call will always result in a null
3997             // pointer exception. The fall-through projection of this CatchNode
3998             // will not be populated.
3999             Node* arg0 = call->in(TypeFunc::Parms);
4000             if (arg0->is_Type() &&
4001                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
4002               required_outcnt--;
4003             }
4004           } else if (call->entry_point() == OptoRuntime::new_array_Java() ||
4005                      call->entry_point() == OptoRuntime::new_array_nozero_Java()) {
4006             // Check for illegal array length. In such case, the optimizer has
4007             // detected that the allocation attempt will always result in an
4008             // exception. There is no fall-through projection of this CatchNode .
4009             assert(call->is_CallStaticJava(), "static call expected");
4010             assert(call->req() == call->jvms()->endoff() + 1, "missing extra input");
4011             uint valid_length_test_input = call->req() - 1;
4012             Node* valid_length_test = call->in(valid_length_test_input);
4013             call->del_req(valid_length_test_input);
4014             if (valid_length_test->find_int_con(1) == 0) {
4015               required_outcnt--;
4016             }
4017             dead_nodes.push(valid_length_test);
4018             assert(n->outcnt() == required_outcnt, "malformed control flow");
4019             continue;
4020           }
4021         }
4022       }
4023 
4024       // Recheck with a better notion of 'required_outcnt'
4025       if (n->outcnt() != required_outcnt) {
4026         record_method_not_compilable("malformed control flow");
4027         return true;            // Not all targets reachable!
4028       }
4029     } else if (n->is_PCTable() && n->in(0) && n->in(0)->in(0) && n->in(0)->in(0)->is_Call()) {
4030       CallNode* call = n->in(0)->in(0)->as_Call();
4031       if (call->entry_point() == OptoRuntime::new_array_Java() ||
4032           call->entry_point() == OptoRuntime::new_array_nozero_Java()) {
4033         assert(call->is_CallStaticJava(), "static call expected");
4034         assert(call->req() == call->jvms()->endoff() + 1, "missing extra input");
4035         uint valid_length_test_input = call->req() - 1;
4036         dead_nodes.push(call->in(valid_length_test_input));
4037         call->del_req(valid_length_test_input); // valid length test useless now
4038       }
4039     }
4040     // Check that I actually visited all kids.  Unreached kids
4041     // must be infinite loops.
4042     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
4043       if (!frc._visited.test(n->fast_out(j)->_idx)) {
4044         record_method_not_compilable("infinite loop");
4045         return true;            // Found unvisited kid; must be unreach
4046       }
4047 
4048     // Here so verification code in final_graph_reshaping_walk()
4049     // always see an OuterStripMinedLoopEnd
4050     if (n->is_OuterStripMinedLoopEnd() || n->is_LongCountedLoopEnd()) {
4051       IfNode* init_iff = n->as_If();
4052       Node* iff = new IfNode(init_iff->in(0), init_iff->in(1), init_iff->_prob, init_iff->_fcnt);
4053       n->subsume_by(iff, this);
4054     }
4055   }
4056 
4057   while (dead_nodes.size() > 0) {
4058     Node* m = dead_nodes.pop();
4059     if (m->outcnt() == 0 && m != top()) {
4060       for (uint j = 0; j < m->req(); j++) {
4061         Node* in = m->in(j);
4062         if (in != nullptr) {
4063           dead_nodes.push(in);
4064         }
4065       }
4066       m->disconnect_inputs(this);
4067     }
4068   }
4069 
4070 #ifdef IA32
4071   // If original bytecodes contained a mixture of floats and doubles
4072   // check if the optimizer has made it homogeneous, item (3).
4073   if (UseSSE == 0 &&
4074       frc.get_float_count() > 32 &&
4075       frc.get_double_count() == 0 &&
4076       (10 * frc.get_call_count() < frc.get_float_count()) ) {
4077     set_24_bit_selection_and_mode(false, true);
4078   }
4079 #endif // IA32
4080 
4081   set_java_calls(frc.get_java_call_count());
4082   set_inner_loops(frc.get_inner_loop_count());
4083 
4084   // No infinite loops, no reason to bail out.
4085   return false;
4086 }
4087 
4088 //-----------------------------too_many_traps----------------------------------
4089 // Report if there are too many traps at the current method and bci.
4090 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
4091 bool Compile::too_many_traps(ciMethod* method,
4092                              int bci,
4093                              Deoptimization::DeoptReason reason) {
4094   ciMethodData* md = method->method_data();
4095   if (md->is_empty()) {
4096     // Assume the trap has not occurred, or that it occurred only
4097     // because of a transient condition during start-up in the interpreter.
4098     return false;
4099   }
4100   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : nullptr;
4101   if (md->has_trap_at(bci, m, reason) != 0) {
4102     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
4103     // Also, if there are multiple reasons, or if there is no per-BCI record,
4104     // assume the worst.
4105     if (log())
4106       log()->elem("observe trap='%s' count='%d'",
4107                   Deoptimization::trap_reason_name(reason),
4108                   md->trap_count(reason));
4109     return true;
4110   } else {
4111     // Ignore method/bci and see if there have been too many globally.
4112     return too_many_traps(reason, md);
4113   }
4114 }
4115 
4116 // Less-accurate variant which does not require a method and bci.
4117 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
4118                              ciMethodData* logmd) {
4119   if (trap_count(reason) >= Deoptimization::per_method_trap_limit(reason)) {
4120     // Too many traps globally.
4121     // Note that we use cumulative trap_count, not just md->trap_count.
4122     if (log()) {
4123       int mcount = (logmd == nullptr)? -1: (int)logmd->trap_count(reason);
4124       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
4125                   Deoptimization::trap_reason_name(reason),
4126                   mcount, trap_count(reason));
4127     }
4128     return true;
4129   } else {
4130     // The coast is clear.
4131     return false;
4132   }
4133 }
4134 
4135 //--------------------------too_many_recompiles--------------------------------
4136 // Report if there are too many recompiles at the current method and bci.
4137 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
4138 // Is not eager to return true, since this will cause the compiler to use
4139 // Action_none for a trap point, to avoid too many recompilations.
4140 bool Compile::too_many_recompiles(ciMethod* method,
4141                                   int bci,
4142                                   Deoptimization::DeoptReason reason) {
4143   ciMethodData* md = method->method_data();
4144   if (md->is_empty()) {
4145     // Assume the trap has not occurred, or that it occurred only
4146     // because of a transient condition during start-up in the interpreter.
4147     return false;
4148   }
4149   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
4150   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
4151   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
4152   Deoptimization::DeoptReason per_bc_reason
4153     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
4154   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : nullptr;
4155   if ((per_bc_reason == Deoptimization::Reason_none
4156        || md->has_trap_at(bci, m, reason) != 0)
4157       // The trap frequency measure we care about is the recompile count:
4158       && md->trap_recompiled_at(bci, m)
4159       && md->overflow_recompile_count() >= bc_cutoff) {
4160     // Do not emit a trap here if it has already caused recompilations.
4161     // Also, if there are multiple reasons, or if there is no per-BCI record,
4162     // assume the worst.
4163     if (log())
4164       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
4165                   Deoptimization::trap_reason_name(reason),
4166                   md->trap_count(reason),
4167                   md->overflow_recompile_count());
4168     return true;
4169   } else if (trap_count(reason) != 0
4170              && decompile_count() >= m_cutoff) {
4171     // Too many recompiles globally, and we have seen this sort of trap.
4172     // Use cumulative decompile_count, not just md->decompile_count.
4173     if (log())
4174       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
4175                   Deoptimization::trap_reason_name(reason),
4176                   md->trap_count(reason), trap_count(reason),
4177                   md->decompile_count(), decompile_count());
4178     return true;
4179   } else {
4180     // The coast is clear.
4181     return false;
4182   }
4183 }
4184 
4185 // Compute when not to trap. Used by matching trap based nodes and
4186 // NullCheck optimization.
4187 void Compile::set_allowed_deopt_reasons() {
4188   _allowed_reasons = 0;
4189   if (is_method_compilation()) {
4190     for (int rs = (int)Deoptimization::Reason_none+1; rs < Compile::trapHistLength; rs++) {
4191       assert(rs < BitsPerInt, "recode bit map");
4192       if (!too_many_traps((Deoptimization::DeoptReason) rs)) {
4193         _allowed_reasons |= nth_bit(rs);
4194       }
4195     }
4196   }
4197 }
4198 
4199 bool Compile::needs_clinit_barrier(ciMethod* method, ciMethod* accessing_method) {
4200   return method->is_static() && needs_clinit_barrier(method->holder(), accessing_method);
4201 }
4202 
4203 bool Compile::needs_clinit_barrier(ciField* field, ciMethod* accessing_method) {
4204   return field->is_static() && needs_clinit_barrier(field->holder(), accessing_method);
4205 }
4206 
4207 bool Compile::needs_clinit_barrier(ciInstanceKlass* holder, ciMethod* accessing_method) {
4208   if (holder->is_initialized()) {
4209     return false;
4210   }
4211   if (holder->is_being_initialized()) {
4212     if (accessing_method->holder() == holder) {
4213       // Access inside a class. The barrier can be elided when access happens in <clinit>,
4214       // <init>, or a static method. In all those cases, there was an initialization
4215       // barrier on the holder klass passed.
4216       if (accessing_method->is_static_initializer() ||
4217           accessing_method->is_object_initializer() ||
4218           accessing_method->is_static()) {
4219         return false;
4220       }
4221     } else if (accessing_method->holder()->is_subclass_of(holder)) {
4222       // Access from a subclass. The barrier can be elided only when access happens in <clinit>.
4223       // In case of <init> or a static method, the barrier is on the subclass is not enough:
4224       // child class can become fully initialized while its parent class is still being initialized.
4225       if (accessing_method->is_static_initializer()) {
4226         return false;
4227       }
4228     }
4229     ciMethod* root = method(); // the root method of compilation
4230     if (root != accessing_method) {
4231       return needs_clinit_barrier(holder, root); // check access in the context of compilation root
4232     }
4233   }
4234   return true;
4235 }
4236 
4237 #ifndef PRODUCT
4238 //------------------------------verify_bidirectional_edges---------------------
4239 // For each input edge to a node (ie - for each Use-Def edge), verify that
4240 // there is a corresponding Def-Use edge.
4241 void Compile::verify_bidirectional_edges(Unique_Node_List &visited) {
4242   // Allocate stack of size C->live_nodes()/16 to avoid frequent realloc
4243   uint stack_size = live_nodes() >> 4;
4244   Node_List nstack(MAX2(stack_size, (uint)OptoNodeListSize));
4245   nstack.push(_root);
4246 
4247   while (nstack.size() > 0) {
4248     Node* n = nstack.pop();
4249     if (visited.member(n)) {
4250       continue;
4251     }
4252     visited.push(n);
4253 
4254     // Walk over all input edges, checking for correspondence
4255     uint length = n->len();
4256     for (uint i = 0; i < length; i++) {
4257       Node* in = n->in(i);
4258       if (in != nullptr && !visited.member(in)) {
4259         nstack.push(in); // Put it on stack
4260       }
4261       if (in != nullptr && !in->is_top()) {
4262         // Count instances of `next`
4263         int cnt = 0;
4264         for (uint idx = 0; idx < in->_outcnt; idx++) {
4265           if (in->_out[idx] == n) {
4266             cnt++;
4267           }
4268         }
4269         assert(cnt > 0, "Failed to find Def-Use edge.");
4270         // Check for duplicate edges
4271         // walk the input array downcounting the input edges to n
4272         for (uint j = 0; j < length; j++) {
4273           if (n->in(j) == in) {
4274             cnt--;
4275           }
4276         }
4277         assert(cnt == 0, "Mismatched edge count.");
4278       } else if (in == nullptr) {
4279         assert(i == 0 || i >= n->req() ||
4280                n->is_Region() || n->is_Phi() || n->is_ArrayCopy() ||
4281                (n->is_Unlock() && i == (n->req() - 1)) ||
4282                (n->is_MemBar() && i == 5), // the precedence edge to a membar can be removed during macro node expansion
4283               "only region, phi, arraycopy, unlock or membar nodes have null data edges");
4284       } else {
4285         assert(in->is_top(), "sanity");
4286         // Nothing to check.
4287       }
4288     }
4289   }
4290 }
4291 
4292 //------------------------------verify_graph_edges---------------------------
4293 // Walk the Graph and verify that there is a one-to-one correspondence
4294 // between Use-Def edges and Def-Use edges in the graph.
4295 void Compile::verify_graph_edges(bool no_dead_code) {
4296   if (VerifyGraphEdges) {
4297     Unique_Node_List visited;
4298 
4299     // Call graph walk to check edges
4300     verify_bidirectional_edges(visited);
4301     if (no_dead_code) {
4302       // Now make sure that no visited node is used by an unvisited node.
4303       bool dead_nodes = false;
4304       Unique_Node_List checked;
4305       while (visited.size() > 0) {
4306         Node* n = visited.pop();
4307         checked.push(n);
4308         for (uint i = 0; i < n->outcnt(); i++) {
4309           Node* use = n->raw_out(i);
4310           if (checked.member(use))  continue;  // already checked
4311           if (visited.member(use))  continue;  // already in the graph
4312           if (use->is_Con())        continue;  // a dead ConNode is OK
4313           // At this point, we have found a dead node which is DU-reachable.
4314           if (!dead_nodes) {
4315             tty->print_cr("*** Dead nodes reachable via DU edges:");
4316             dead_nodes = true;
4317           }
4318           use->dump(2);
4319           tty->print_cr("---");
4320           checked.push(use);  // No repeats; pretend it is now checked.
4321         }
4322       }
4323       assert(!dead_nodes, "using nodes must be reachable from root");
4324     }
4325   }
4326 }
4327 #endif
4328 
4329 // The Compile object keeps track of failure reasons separately from the ciEnv.
4330 // This is required because there is not quite a 1-1 relation between the
4331 // ciEnv and its compilation task and the Compile object.  Note that one
4332 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
4333 // to backtrack and retry without subsuming loads.  Other than this backtracking
4334 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
4335 // by the logic in C2Compiler.
4336 void Compile::record_failure(const char* reason DEBUG_ONLY(COMMA bool allow_multiple_failures)) {
4337   if (log() != nullptr) {
4338     log()->elem("failure reason='%s' phase='compile'", reason);
4339   }
4340   if (_failure_reason.get() == nullptr) {
4341     // Record the first failure reason.
4342     _failure_reason.set(reason);
4343     if (CaptureBailoutInformation) {
4344       _first_failure_details = new CompilationFailureInfo(reason);
4345     }
4346   } else {
4347     assert(!StressBailout || allow_multiple_failures, "should have handled previous failure.");
4348   }
4349 
4350   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
4351     C->print_method(PHASE_FAILURE, 1);
4352   }
4353   _root = nullptr;  // flush the graph, too
4354 }
4355 
4356 Compile::TracePhase::TracePhase(const char* name, elapsedTimer* accumulator)
4357   : TraceTime(name, accumulator, CITime, CITimeVerbose),
4358     _compile(Compile::current()),
4359     _log(nullptr),
4360     _phase_name(name),
4361     _dolog(CITimeVerbose)
4362 {
4363   assert(_compile != nullptr, "sanity check");
4364   if (_dolog) {
4365     _log = _compile->log();
4366   }
4367   if (_log != nullptr) {
4368     _log->begin_head("phase name='%s' nodes='%d' live='%d'", _phase_name, _compile->unique(), _compile->live_nodes());
4369     _log->stamp();
4370     _log->end_head();
4371   }
4372 }
4373 
4374 Compile::TracePhase::~TracePhase() {
4375   if (_compile->failing_internal()) {
4376     return; // timing code, not stressing bailouts.
4377   }
4378 #ifdef ASSERT
4379   if (PrintIdealNodeCount) {
4380     tty->print_cr("phase name='%s' nodes='%d' live='%d' live_graph_walk='%d'",
4381                   _phase_name, _compile->unique(), _compile->live_nodes(), _compile->count_live_nodes_by_graph_walk());
4382   }
4383 
4384   if (VerifyIdealNodeCount) {
4385     _compile->print_missing_nodes();
4386   }
4387 #endif
4388 
4389   if (_log != nullptr) {
4390     _log->done("phase name='%s' nodes='%d' live='%d'", _phase_name, _compile->unique(), _compile->live_nodes());
4391   }
4392 }
4393 
4394 //----------------------------static_subtype_check-----------------------------
4395 // Shortcut important common cases when superklass is exact:
4396 // (0) superklass is java.lang.Object (can occur in reflective code)
4397 // (1) subklass is already limited to a subtype of superklass => always ok
4398 // (2) subklass does not overlap with superklass => always fail
4399 // (3) superklass has NO subtypes and we can check with a simple compare.
4400 Compile::SubTypeCheckResult Compile::static_subtype_check(const TypeKlassPtr* superk, const TypeKlassPtr* subk, bool skip) {
4401   if (skip) {
4402     return SSC_full_test;       // Let caller generate the general case.
4403   }
4404 
4405   if (subk->is_java_subtype_of(superk)) {
4406     return SSC_always_true; // (0) and (1)  this test cannot fail
4407   }
4408 
4409   if (!subk->maybe_java_subtype_of(superk)) {
4410     return SSC_always_false; // (2) true path dead; no dynamic test needed
4411   }
4412 
4413   const Type* superelem = superk;
4414   if (superk->isa_aryklassptr()) {
4415     int ignored;
4416     superelem = superk->is_aryklassptr()->base_element_type(ignored);
4417   }
4418 
4419   if (superelem->isa_instklassptr()) {
4420     ciInstanceKlass* ik = superelem->is_instklassptr()->instance_klass();
4421     if (!ik->has_subklass()) {
4422       if (!ik->is_final()) {
4423         // Add a dependency if there is a chance of a later subclass.
4424         dependencies()->assert_leaf_type(ik);
4425       }
4426       if (!superk->maybe_java_subtype_of(subk)) {
4427         return SSC_always_false;
4428       }
4429       return SSC_easy_test;     // (3) caller can do a simple ptr comparison
4430     }
4431   } else {
4432     // A primitive array type has no subtypes.
4433     return SSC_easy_test;       // (3) caller can do a simple ptr comparison
4434   }
4435 
4436   return SSC_full_test;
4437 }
4438 
4439 Node* Compile::conv_I2X_index(PhaseGVN* phase, Node* idx, const TypeInt* sizetype, Node* ctrl) {
4440 #ifdef _LP64
4441   // The scaled index operand to AddP must be a clean 64-bit value.
4442   // Java allows a 32-bit int to be incremented to a negative
4443   // value, which appears in a 64-bit register as a large
4444   // positive number.  Using that large positive number as an
4445   // operand in pointer arithmetic has bad consequences.
4446   // On the other hand, 32-bit overflow is rare, and the possibility
4447   // can often be excluded, if we annotate the ConvI2L node with
4448   // a type assertion that its value is known to be a small positive
4449   // number.  (The prior range check has ensured this.)
4450   // This assertion is used by ConvI2LNode::Ideal.
4451   int index_max = max_jint - 1;  // array size is max_jint, index is one less
4452   if (sizetype != nullptr) index_max = sizetype->_hi - 1;
4453   const TypeInt* iidxtype = TypeInt::make(0, index_max, Type::WidenMax);
4454   idx = constrained_convI2L(phase, idx, iidxtype, ctrl);
4455 #endif
4456   return idx;
4457 }
4458 
4459 // Convert integer value to a narrowed long type dependent on ctrl (for example, a range check)
4460 Node* Compile::constrained_convI2L(PhaseGVN* phase, Node* value, const TypeInt* itype, Node* ctrl, bool carry_dependency) {
4461   if (ctrl != nullptr) {
4462     // Express control dependency by a CastII node with a narrow type.
4463     // Make the CastII node dependent on the control input to prevent the narrowed ConvI2L
4464     // node from floating above the range check during loop optimizations. Otherwise, the
4465     // ConvI2L node may be eliminated independently of the range check, causing the data path
4466     // to become TOP while the control path is still there (although it's unreachable).
4467     value = new CastIINode(ctrl, value, itype, carry_dependency ? ConstraintCastNode::StrongDependency : ConstraintCastNode::RegularDependency, true /* range check dependency */);
4468     value = phase->transform(value);
4469   }
4470   const TypeLong* ltype = TypeLong::make(itype->_lo, itype->_hi, itype->_widen);
4471   return phase->transform(new ConvI2LNode(value, ltype));
4472 }
4473 
4474 // The message about the current inlining is accumulated in
4475 // _print_inlining_stream and transferred into the _print_inlining_list
4476 // once we know whether inlining succeeds or not. For regular
4477 // inlining, messages are appended to the buffer pointed by
4478 // _print_inlining_idx in the _print_inlining_list. For late inlining,
4479 // a new buffer is added after _print_inlining_idx in the list. This
4480 // way we can update the inlining message for late inlining call site
4481 // when the inlining is attempted again.
4482 void Compile::print_inlining_init() {
4483   if (print_inlining() || print_intrinsics()) {
4484     // print_inlining_init is actually called several times.
4485     print_inlining_reset();
4486     _print_inlining_list = new (comp_arena())GrowableArray<PrintInliningBuffer*>(comp_arena(), 1, 1, new PrintInliningBuffer());
4487   }
4488 }
4489 
4490 void Compile::print_inlining_reinit() {
4491   if (print_inlining() || print_intrinsics()) {
4492     print_inlining_reset();
4493   }
4494 }
4495 
4496 void Compile::print_inlining_reset() {
4497   _print_inlining_stream->reset();
4498 }
4499 
4500 void Compile::print_inlining_commit() {
4501   assert(print_inlining() || print_intrinsics(), "PrintInlining off?");
4502   // Transfer the message from _print_inlining_stream to the current
4503   // _print_inlining_list buffer and clear _print_inlining_stream.
4504   _print_inlining_list->at(_print_inlining_idx)->ss()->write(_print_inlining_stream->base(), _print_inlining_stream->size());
4505   print_inlining_reset();
4506 }
4507 
4508 void Compile::print_inlining_push() {
4509   // Add new buffer to the _print_inlining_list at current position
4510   _print_inlining_idx++;
4511   _print_inlining_list->insert_before(_print_inlining_idx, new PrintInliningBuffer());
4512 }
4513 
4514 Compile::PrintInliningBuffer* Compile::print_inlining_current() {
4515   return _print_inlining_list->at(_print_inlining_idx);
4516 }
4517 
4518 void Compile::print_inlining_update(CallGenerator* cg) {
4519   if (print_inlining() || print_intrinsics()) {
4520     if (cg->is_late_inline()) {
4521       if (print_inlining_current()->cg() != cg &&
4522           (print_inlining_current()->cg() != nullptr ||
4523            print_inlining_current()->ss()->size() != 0)) {
4524         print_inlining_push();
4525       }
4526       print_inlining_commit();
4527       print_inlining_current()->set_cg(cg);
4528     } else {
4529       if (print_inlining_current()->cg() != nullptr) {
4530         print_inlining_push();
4531       }
4532       print_inlining_commit();
4533     }
4534   }
4535 }
4536 
4537 void Compile::print_inlining_move_to(CallGenerator* cg) {
4538   // We resume inlining at a late inlining call site. Locate the
4539   // corresponding inlining buffer so that we can update it.
4540   if (print_inlining() || print_intrinsics()) {
4541     for (int i = 0; i < _print_inlining_list->length(); i++) {
4542       if (_print_inlining_list->at(i)->cg() == cg) {
4543         _print_inlining_idx = i;
4544         return;
4545       }
4546     }
4547     ShouldNotReachHere();
4548   }
4549 }
4550 
4551 void Compile::print_inlining_update_delayed(CallGenerator* cg) {
4552   if (print_inlining() || print_intrinsics()) {
4553     assert(_print_inlining_stream->size() > 0, "missing inlining msg");
4554     assert(print_inlining_current()->cg() == cg, "wrong entry");
4555     // replace message with new message
4556     _print_inlining_list->at_put(_print_inlining_idx, new PrintInliningBuffer());
4557     print_inlining_commit();
4558     print_inlining_current()->set_cg(cg);
4559   }
4560 }
4561 
4562 void Compile::print_inlining_assert_ready() {
4563   assert(!_print_inlining || _print_inlining_stream->size() == 0, "losing data");
4564 }
4565 
4566 void Compile::process_print_inlining() {
4567   assert(_late_inlines.length() == 0, "not drained yet");
4568   if (print_inlining() || print_intrinsics()) {
4569     ResourceMark rm;
4570     stringStream ss;
4571     assert(_print_inlining_list != nullptr, "process_print_inlining should be called only once.");
4572     for (int i = 0; i < _print_inlining_list->length(); i++) {
4573       PrintInliningBuffer* pib = _print_inlining_list->at(i);
4574       ss.print("%s", pib->ss()->freeze());
4575       delete pib;
4576       DEBUG_ONLY(_print_inlining_list->at_put(i, nullptr));
4577     }
4578     // Reset _print_inlining_list, it only contains destructed objects.
4579     // It is on the arena, so it will be freed when the arena is reset.
4580     _print_inlining_list = nullptr;
4581     // _print_inlining_stream won't be used anymore, either.
4582     print_inlining_reset();
4583     size_t end = ss.size();
4584     _print_inlining_output = NEW_ARENA_ARRAY(comp_arena(), char, end+1);
4585     strncpy(_print_inlining_output, ss.freeze(), end+1);
4586     _print_inlining_output[end] = 0;
4587   }
4588 }
4589 
4590 void Compile::dump_print_inlining() {
4591   if (_print_inlining_output != nullptr) {
4592     tty->print_raw(_print_inlining_output);
4593   }
4594 }
4595 
4596 void Compile::log_late_inline(CallGenerator* cg) {
4597   if (log() != nullptr) {
4598     log()->head("late_inline method='%d'  inline_id='" JLONG_FORMAT "'", log()->identify(cg->method()),
4599                 cg->unique_id());
4600     JVMState* p = cg->call_node()->jvms();
4601     while (p != nullptr) {
4602       log()->elem("jvms bci='%d' method='%d'", p->bci(), log()->identify(p->method()));
4603       p = p->caller();
4604     }
4605     log()->tail("late_inline");
4606   }
4607 }
4608 
4609 void Compile::log_late_inline_failure(CallGenerator* cg, const char* msg) {
4610   log_late_inline(cg);
4611   if (log() != nullptr) {
4612     log()->inline_fail(msg);
4613   }
4614 }
4615 
4616 void Compile::log_inline_id(CallGenerator* cg) {
4617   if (log() != nullptr) {
4618     // The LogCompilation tool needs a unique way to identify late
4619     // inline call sites. This id must be unique for this call site in
4620     // this compilation. Try to have it unique across compilations as
4621     // well because it can be convenient when grepping through the log
4622     // file.
4623     // Distinguish OSR compilations from others in case CICountOSR is
4624     // on.
4625     jlong id = ((jlong)unique()) + (((jlong)compile_id()) << 33) + (CICountOSR && is_osr_compilation() ? ((jlong)1) << 32 : 0);
4626     cg->set_unique_id(id);
4627     log()->elem("inline_id id='" JLONG_FORMAT "'", id);
4628   }
4629 }
4630 
4631 void Compile::log_inline_failure(const char* msg) {
4632   if (C->log() != nullptr) {
4633     C->log()->inline_fail(msg);
4634   }
4635 }
4636 
4637 
4638 // Dump inlining replay data to the stream.
4639 // Don't change thread state and acquire any locks.
4640 void Compile::dump_inline_data(outputStream* out) {
4641   InlineTree* inl_tree = ilt();
4642   if (inl_tree != nullptr) {
4643     out->print(" inline %d", inl_tree->count());
4644     inl_tree->dump_replay_data(out);
4645   }
4646 }
4647 
4648 void Compile::dump_inline_data_reduced(outputStream* out) {
4649   assert(ReplayReduce, "");
4650 
4651   InlineTree* inl_tree = ilt();
4652   if (inl_tree == nullptr) {
4653     return;
4654   }
4655   // Enable iterative replay file reduction
4656   // Output "compile" lines for depth 1 subtrees,
4657   // simulating that those trees were compiled
4658   // instead of inlined.
4659   for (int i = 0; i < inl_tree->subtrees().length(); ++i) {
4660     InlineTree* sub = inl_tree->subtrees().at(i);
4661     if (sub->inline_level() != 1) {
4662       continue;
4663     }
4664 
4665     ciMethod* method = sub->method();
4666     int entry_bci = -1;
4667     int comp_level = env()->task()->comp_level();
4668     out->print("compile ");
4669     method->dump_name_as_ascii(out);
4670     out->print(" %d %d", entry_bci, comp_level);
4671     out->print(" inline %d", sub->count());
4672     sub->dump_replay_data(out, -1);
4673     out->cr();
4674   }
4675 }
4676 
4677 int Compile::cmp_expensive_nodes(Node* n1, Node* n2) {
4678   if (n1->Opcode() < n2->Opcode())      return -1;
4679   else if (n1->Opcode() > n2->Opcode()) return 1;
4680 
4681   assert(n1->req() == n2->req(), "can't compare %s nodes: n1->req() = %d, n2->req() = %d", NodeClassNames[n1->Opcode()], n1->req(), n2->req());
4682   for (uint i = 1; i < n1->req(); i++) {
4683     if (n1->in(i) < n2->in(i))      return -1;
4684     else if (n1->in(i) > n2->in(i)) return 1;
4685   }
4686 
4687   return 0;
4688 }
4689 
4690 int Compile::cmp_expensive_nodes(Node** n1p, Node** n2p) {
4691   Node* n1 = *n1p;
4692   Node* n2 = *n2p;
4693 
4694   return cmp_expensive_nodes(n1, n2);
4695 }
4696 
4697 void Compile::sort_expensive_nodes() {
4698   if (!expensive_nodes_sorted()) {
4699     _expensive_nodes.sort(cmp_expensive_nodes);
4700   }
4701 }
4702 
4703 bool Compile::expensive_nodes_sorted() const {
4704   for (int i = 1; i < _expensive_nodes.length(); i++) {
4705     if (cmp_expensive_nodes(_expensive_nodes.adr_at(i), _expensive_nodes.adr_at(i-1)) < 0) {
4706       return false;
4707     }
4708   }
4709   return true;
4710 }
4711 
4712 bool Compile::should_optimize_expensive_nodes(PhaseIterGVN &igvn) {
4713   if (_expensive_nodes.length() == 0) {
4714     return false;
4715   }
4716 
4717   assert(OptimizeExpensiveOps, "optimization off?");
4718 
4719   // Take this opportunity to remove dead nodes from the list
4720   int j = 0;
4721   for (int i = 0; i < _expensive_nodes.length(); i++) {
4722     Node* n = _expensive_nodes.at(i);
4723     if (!n->is_unreachable(igvn)) {
4724       assert(n->is_expensive(), "should be expensive");
4725       _expensive_nodes.at_put(j, n);
4726       j++;
4727     }
4728   }
4729   _expensive_nodes.trunc_to(j);
4730 
4731   // Then sort the list so that similar nodes are next to each other
4732   // and check for at least two nodes of identical kind with same data
4733   // inputs.
4734   sort_expensive_nodes();
4735 
4736   for (int i = 0; i < _expensive_nodes.length()-1; i++) {
4737     if (cmp_expensive_nodes(_expensive_nodes.adr_at(i), _expensive_nodes.adr_at(i+1)) == 0) {
4738       return true;
4739     }
4740   }
4741 
4742   return false;
4743 }
4744 
4745 void Compile::cleanup_expensive_nodes(PhaseIterGVN &igvn) {
4746   if (_expensive_nodes.length() == 0) {
4747     return;
4748   }
4749 
4750   assert(OptimizeExpensiveOps, "optimization off?");
4751 
4752   // Sort to bring similar nodes next to each other and clear the
4753   // control input of nodes for which there's only a single copy.
4754   sort_expensive_nodes();
4755 
4756   int j = 0;
4757   int identical = 0;
4758   int i = 0;
4759   bool modified = false;
4760   for (; i < _expensive_nodes.length()-1; i++) {
4761     assert(j <= i, "can't write beyond current index");
4762     if (_expensive_nodes.at(i)->Opcode() == _expensive_nodes.at(i+1)->Opcode()) {
4763       identical++;
4764       _expensive_nodes.at_put(j++, _expensive_nodes.at(i));
4765       continue;
4766     }
4767     if (identical > 0) {
4768       _expensive_nodes.at_put(j++, _expensive_nodes.at(i));
4769       identical = 0;
4770     } else {
4771       Node* n = _expensive_nodes.at(i);
4772       igvn.replace_input_of(n, 0, nullptr);
4773       igvn.hash_insert(n);
4774       modified = true;
4775     }
4776   }
4777   if (identical > 0) {
4778     _expensive_nodes.at_put(j++, _expensive_nodes.at(i));
4779   } else if (_expensive_nodes.length() >= 1) {
4780     Node* n = _expensive_nodes.at(i);
4781     igvn.replace_input_of(n, 0, nullptr);
4782     igvn.hash_insert(n);
4783     modified = true;
4784   }
4785   _expensive_nodes.trunc_to(j);
4786   if (modified) {
4787     igvn.optimize();
4788   }
4789 }
4790 
4791 void Compile::add_expensive_node(Node * n) {
4792   assert(!_expensive_nodes.contains(n), "duplicate entry in expensive list");
4793   assert(n->is_expensive(), "expensive nodes with non-null control here only");
4794   assert(!n->is_CFG() && !n->is_Mem(), "no cfg or memory nodes here");
4795   if (OptimizeExpensiveOps) {
4796     _expensive_nodes.append(n);
4797   } else {
4798     // Clear control input and let IGVN optimize expensive nodes if
4799     // OptimizeExpensiveOps is off.
4800     n->set_req(0, nullptr);
4801   }
4802 }
4803 
4804 /**
4805  * Track coarsened Lock and Unlock nodes.
4806  */
4807 
4808 class Lock_List : public Node_List {
4809   uint _origin_cnt;
4810 public:
4811   Lock_List(Arena *a, uint cnt) : Node_List(a), _origin_cnt(cnt) {}
4812   uint origin_cnt() const { return _origin_cnt; }
4813 };
4814 
4815 void Compile::add_coarsened_locks(GrowableArray<AbstractLockNode*>& locks) {
4816   int length = locks.length();
4817   if (length > 0) {
4818     // Have to keep this list until locks elimination during Macro nodes elimination.
4819     Lock_List* locks_list = new (comp_arena()) Lock_List(comp_arena(), length);
4820     AbstractLockNode* alock = locks.at(0);
4821     BoxLockNode* box = alock->box_node()->as_BoxLock();
4822     for (int i = 0; i < length; i++) {
4823       AbstractLockNode* lock = locks.at(i);
4824       assert(lock->is_coarsened(), "expecting only coarsened AbstractLock nodes, but got '%s'[%d] node", lock->Name(), lock->_idx);
4825       locks_list->push(lock);
4826       BoxLockNode* this_box = lock->box_node()->as_BoxLock();
4827       if (this_box != box) {
4828         // Locking regions (BoxLock) could be Unbalanced here:
4829         //  - its coarsened locks were eliminated in earlier
4830         //    macro nodes elimination followed by loop unroll
4831         //  - it is OSR locking region (no Lock node)
4832         // Preserve Unbalanced status in such cases.
4833         if (!this_box->is_unbalanced()) {
4834           this_box->set_coarsened();
4835         }
4836         if (!box->is_unbalanced()) {
4837           box->set_coarsened();
4838         }
4839       }
4840     }
4841     _coarsened_locks.append(locks_list);
4842   }
4843 }
4844 
4845 void Compile::remove_useless_coarsened_locks(Unique_Node_List& useful) {
4846   int count = coarsened_count();
4847   for (int i = 0; i < count; i++) {
4848     Node_List* locks_list = _coarsened_locks.at(i);
4849     for (uint j = 0; j < locks_list->size(); j++) {
4850       Node* lock = locks_list->at(j);
4851       assert(lock->is_AbstractLock(), "sanity");
4852       if (!useful.member(lock)) {
4853         locks_list->yank(lock);
4854       }
4855     }
4856   }
4857 }
4858 
4859 void Compile::remove_coarsened_lock(Node* n) {
4860   if (n->is_AbstractLock()) {
4861     int count = coarsened_count();
4862     for (int i = 0; i < count; i++) {
4863       Node_List* locks_list = _coarsened_locks.at(i);
4864       locks_list->yank(n);
4865     }
4866   }
4867 }
4868 
4869 bool Compile::coarsened_locks_consistent() {
4870   int count = coarsened_count();
4871   for (int i = 0; i < count; i++) {
4872     bool unbalanced = false;
4873     bool modified = false; // track locks kind modifications
4874     Lock_List* locks_list = (Lock_List*)_coarsened_locks.at(i);
4875     uint size = locks_list->size();
4876     if (size == 0) {
4877       unbalanced = false; // All locks were eliminated - good
4878     } else if (size != locks_list->origin_cnt()) {
4879       unbalanced = true; // Some locks were removed from list
4880     } else {
4881       for (uint j = 0; j < size; j++) {
4882         Node* lock = locks_list->at(j);
4883         // All nodes in group should have the same state (modified or not)
4884         if (!lock->as_AbstractLock()->is_coarsened()) {
4885           if (j == 0) {
4886             // first on list was modified, the rest should be too for consistency
4887             modified = true;
4888           } else if (!modified) {
4889             // this lock was modified but previous locks on the list were not
4890             unbalanced = true;
4891             break;
4892           }
4893         } else if (modified) {
4894           // previous locks on list were modified but not this lock
4895           unbalanced = true;
4896           break;
4897         }
4898       }
4899     }
4900     if (unbalanced) {
4901       // unbalanced monitor enter/exit - only some [un]lock nodes were removed or modified
4902 #ifdef ASSERT
4903       if (PrintEliminateLocks) {
4904         tty->print_cr("=== unbalanced coarsened locks ===");
4905         for (uint l = 0; l < size; l++) {
4906           locks_list->at(l)->dump();
4907         }
4908       }
4909 #endif
4910       record_failure(C2Compiler::retry_no_locks_coarsening());
4911       return false;
4912     }
4913   }
4914   return true;
4915 }
4916 
4917 // Mark locking regions (identified by BoxLockNode) as unbalanced if
4918 // locks coarsening optimization removed Lock/Unlock nodes from them.
4919 // Such regions become unbalanced because coarsening only removes part
4920 // of Lock/Unlock nodes in region. As result we can't execute other
4921 // locks elimination optimizations which assume all code paths have
4922 // corresponding pair of Lock/Unlock nodes - they are balanced.
4923 void Compile::mark_unbalanced_boxes() const {
4924   int count = coarsened_count();
4925   for (int i = 0; i < count; i++) {
4926     Node_List* locks_list = _coarsened_locks.at(i);
4927     uint size = locks_list->size();
4928     if (size > 0) {
4929       AbstractLockNode* alock = locks_list->at(0)->as_AbstractLock();
4930       BoxLockNode* box = alock->box_node()->as_BoxLock();
4931       if (alock->is_coarsened()) {
4932         // coarsened_locks_consistent(), which is called before this method, verifies
4933         // that the rest of Lock/Unlock nodes on locks_list are also coarsened.
4934         assert(!box->is_eliminated(), "regions with coarsened locks should not be marked as eliminated");
4935         for (uint j = 1; j < size; j++) {
4936           assert(locks_list->at(j)->as_AbstractLock()->is_coarsened(), "only coarsened locks are expected here");
4937           BoxLockNode* this_box = locks_list->at(j)->as_AbstractLock()->box_node()->as_BoxLock();
4938           if (box != this_box) {
4939             assert(!this_box->is_eliminated(), "regions with coarsened locks should not be marked as eliminated");
4940             box->set_unbalanced();
4941             this_box->set_unbalanced();
4942           }
4943         }
4944       }
4945     }
4946   }
4947 }
4948 
4949 /**
4950  * Remove the speculative part of types and clean up the graph
4951  */
4952 void Compile::remove_speculative_types(PhaseIterGVN &igvn) {
4953   if (UseTypeSpeculation) {
4954     Unique_Node_List worklist;
4955     worklist.push(root());
4956     int modified = 0;
4957     // Go over all type nodes that carry a speculative type, drop the
4958     // speculative part of the type and enqueue the node for an igvn
4959     // which may optimize it out.
4960     for (uint next = 0; next < worklist.size(); ++next) {
4961       Node *n  = worklist.at(next);
4962       if (n->is_Type()) {
4963         TypeNode* tn = n->as_Type();
4964         const Type* t = tn->type();
4965         const Type* t_no_spec = t->remove_speculative();
4966         if (t_no_spec != t) {
4967           bool in_hash = igvn.hash_delete(n);
4968           assert(in_hash || n->hash() == Node::NO_HASH, "node should be in igvn hash table");
4969           tn->set_type(t_no_spec);
4970           igvn.hash_insert(n);
4971           igvn._worklist.push(n); // give it a chance to go away
4972           modified++;
4973         }
4974       }
4975       // Iterate over outs - endless loops is unreachable from below
4976       for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
4977         Node *m = n->fast_out(i);
4978         if (not_a_node(m)) {
4979           continue;
4980         }
4981         worklist.push(m);
4982       }
4983     }
4984     // Drop the speculative part of all types in the igvn's type table
4985     igvn.remove_speculative_types();
4986     if (modified > 0) {
4987       igvn.optimize();
4988       if (failing())  return;
4989     }
4990 #ifdef ASSERT
4991     // Verify that after the IGVN is over no speculative type has resurfaced
4992     worklist.clear();
4993     worklist.push(root());
4994     for (uint next = 0; next < worklist.size(); ++next) {
4995       Node *n  = worklist.at(next);
4996       const Type* t = igvn.type_or_null(n);
4997       assert((t == nullptr) || (t == t->remove_speculative()), "no more speculative types");
4998       if (n->is_Type()) {
4999         t = n->as_Type()->type();
5000         assert(t == t->remove_speculative(), "no more speculative types");
5001       }
5002       // Iterate over outs - endless loops is unreachable from below
5003       for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
5004         Node *m = n->fast_out(i);
5005         if (not_a_node(m)) {
5006           continue;
5007         }
5008         worklist.push(m);
5009       }
5010     }
5011     igvn.check_no_speculative_types();
5012 #endif
5013   }
5014 }
5015 
5016 // Auxiliary methods to support randomized stressing/fuzzing.
5017 
5018 void Compile::initialize_stress_seed(const DirectiveSet* directive) {
5019   if (FLAG_IS_DEFAULT(StressSeed) || (FLAG_IS_ERGO(StressSeed) && directive->RepeatCompilationOption)) {
5020     _stress_seed = static_cast<uint>(Ticks::now().nanoseconds());
5021     FLAG_SET_ERGO(StressSeed, _stress_seed);
5022   } else {
5023     _stress_seed = StressSeed;
5024   }
5025   if (_log != nullptr) {
5026     _log->elem("stress_test seed='%u'", _stress_seed);
5027   }
5028 }
5029 
5030 int Compile::random() {
5031   _stress_seed = os::next_random(_stress_seed);
5032   return static_cast<int>(_stress_seed);
5033 }
5034 
5035 // This method can be called the arbitrary number of times, with current count
5036 // as the argument. The logic allows selecting a single candidate from the
5037 // running list of candidates as follows:
5038 //    int count = 0;
5039 //    Cand* selected = null;
5040 //    while(cand = cand->next()) {
5041 //      if (randomized_select(++count)) {
5042 //        selected = cand;
5043 //      }
5044 //    }
5045 //
5046 // Including count equalizes the chances any candidate is "selected".
5047 // This is useful when we don't have the complete list of candidates to choose
5048 // from uniformly. In this case, we need to adjust the randomicity of the
5049 // selection, or else we will end up biasing the selection towards the latter
5050 // candidates.
5051 //
5052 // Quick back-envelope calculation shows that for the list of n candidates
5053 // the equal probability for the candidate to persist as "best" can be
5054 // achieved by replacing it with "next" k-th candidate with the probability
5055 // of 1/k. It can be easily shown that by the end of the run, the
5056 // probability for any candidate is converged to 1/n, thus giving the
5057 // uniform distribution among all the candidates.
5058 //
5059 // We don't care about the domain size as long as (RANDOMIZED_DOMAIN / count) is large.
5060 #define RANDOMIZED_DOMAIN_POW 29
5061 #define RANDOMIZED_DOMAIN (1 << RANDOMIZED_DOMAIN_POW)
5062 #define RANDOMIZED_DOMAIN_MASK ((1 << (RANDOMIZED_DOMAIN_POW + 1)) - 1)
5063 bool Compile::randomized_select(int count) {
5064   assert(count > 0, "only positive");
5065   return (random() & RANDOMIZED_DOMAIN_MASK) < (RANDOMIZED_DOMAIN / count);
5066 }
5067 
5068 #ifdef ASSERT
5069 // Failures are geometrically distributed with probability 1/StressBailoutMean.
5070 bool Compile::fail_randomly() {
5071   if ((random() % StressBailoutMean) != 0) {
5072     return false;
5073   }
5074   record_failure("StressBailout");
5075   return true;
5076 }
5077 
5078 bool Compile::failure_is_artificial() {
5079   assert(failing_internal(), "should be failing");
5080   return C->failure_reason_is("StressBailout");
5081 }
5082 #endif
5083 
5084 CloneMap&     Compile::clone_map()                 { return _clone_map; }
5085 void          Compile::set_clone_map(Dict* d)      { _clone_map._dict = d; }
5086 
5087 void NodeCloneInfo::dump_on(outputStream* st) const {
5088   st->print(" {%d:%d} ", idx(), gen());
5089 }
5090 
5091 void CloneMap::clone(Node* old, Node* nnn, int gen) {
5092   uint64_t val = value(old->_idx);
5093   NodeCloneInfo cio(val);
5094   assert(val != 0, "old node should be in the map");
5095   NodeCloneInfo cin(cio.idx(), gen + cio.gen());
5096   insert(nnn->_idx, cin.get());
5097 #ifndef PRODUCT
5098   if (is_debug()) {
5099     tty->print_cr("CloneMap::clone inserted node %d info {%d:%d} into CloneMap", nnn->_idx, cin.idx(), cin.gen());
5100   }
5101 #endif
5102 }
5103 
5104 void CloneMap::verify_insert_and_clone(Node* old, Node* nnn, int gen) {
5105   NodeCloneInfo cio(value(old->_idx));
5106   if (cio.get() == 0) {
5107     cio.set(old->_idx, 0);
5108     insert(old->_idx, cio.get());
5109 #ifndef PRODUCT
5110     if (is_debug()) {
5111       tty->print_cr("CloneMap::verify_insert_and_clone inserted node %d info {%d:%d} into CloneMap", old->_idx, cio.idx(), cio.gen());
5112     }
5113 #endif
5114   }
5115   clone(old, nnn, gen);
5116 }
5117 
5118 int CloneMap::max_gen() const {
5119   int g = 0;
5120   DictI di(_dict);
5121   for(; di.test(); ++di) {
5122     int t = gen(di._key);
5123     if (g < t) {
5124       g = t;
5125 #ifndef PRODUCT
5126       if (is_debug()) {
5127         tty->print_cr("CloneMap::max_gen() update max=%d from %d", g, _2_node_idx_t(di._key));
5128       }
5129 #endif
5130     }
5131   }
5132   return g;
5133 }
5134 
5135 void CloneMap::dump(node_idx_t key, outputStream* st) const {
5136   uint64_t val = value(key);
5137   if (val != 0) {
5138     NodeCloneInfo ni(val);
5139     ni.dump_on(st);
5140   }
5141 }
5142 
5143 void Compile::shuffle_macro_nodes() {
5144   if (_macro_nodes.length() < 2) {
5145     return;
5146   }
5147   for (uint i = _macro_nodes.length() - 1; i >= 1; i--) {
5148     uint j = C->random() % (i + 1);
5149     swap(_macro_nodes.at(i), _macro_nodes.at(j));
5150   }
5151 }
5152 
5153 // Move Allocate nodes to the start of the list
5154 void Compile::sort_macro_nodes() {
5155   int count = macro_count();
5156   int allocates = 0;
5157   for (int i = 0; i < count; i++) {
5158     Node* n = macro_node(i);
5159     if (n->is_Allocate()) {
5160       if (i != allocates) {
5161         Node* tmp = macro_node(allocates);
5162         _macro_nodes.at_put(allocates, n);
5163         _macro_nodes.at_put(i, tmp);
5164       }
5165       allocates++;
5166     }
5167   }
5168 }
5169 
5170 void Compile::print_method(CompilerPhaseType cpt, int level, Node* n) {
5171   if (failing_internal()) { return; } // failing_internal to not stress bailouts from printing code.
5172   EventCompilerPhase event(UNTIMED);
5173   if (event.should_commit()) {
5174     CompilerEvent::PhaseEvent::post(event, C->_latest_stage_start_counter, cpt, C->_compile_id, level);
5175   }
5176 #ifndef PRODUCT
5177   ResourceMark rm;
5178   stringStream ss;
5179   ss.print_raw(CompilerPhaseTypeHelper::to_description(cpt));
5180   int iter = ++_igv_phase_iter[cpt];
5181   if (iter > 1) {
5182     ss.print(" %d", iter);
5183   }
5184   if (n != nullptr) {
5185     ss.print(": %d %s", n->_idx, NodeClassNames[n->Opcode()]);
5186     if (n->is_Call()) {
5187       CallNode* call = n->as_Call();
5188       if (call->_name != nullptr) {
5189         // E.g. uncommon traps etc.
5190         ss.print(" - %s", call->_name);
5191       } else if (call->is_CallJava()) {
5192         CallJavaNode* call_java = call->as_CallJava();
5193         if (call_java->method() != nullptr) {
5194           ss.print(" -");
5195           call_java->method()->print_short_name(&ss);
5196         }
5197       }
5198     }
5199   }
5200 
5201   const char* name = ss.as_string();
5202   if (should_print_igv(level)) {
5203     _igv_printer->print_method(name, level);
5204   }
5205   if (should_print_phase(cpt)) {
5206     print_ideal_ir(CompilerPhaseTypeHelper::to_name(cpt));
5207   }
5208 #endif
5209   C->_latest_stage_start_counter.stamp();
5210 }
5211 
5212 // Only used from CompileWrapper
5213 void Compile::begin_method() {
5214 #ifndef PRODUCT
5215   if (_method != nullptr && should_print_igv(1)) {
5216     _igv_printer->begin_method();
5217   }
5218 #endif
5219   C->_latest_stage_start_counter.stamp();
5220 }
5221 
5222 // Only used from CompileWrapper
5223 void Compile::end_method() {
5224   EventCompilerPhase event(UNTIMED);
5225   if (event.should_commit()) {
5226     CompilerEvent::PhaseEvent::post(event, C->_latest_stage_start_counter, PHASE_END, C->_compile_id, 1);
5227   }
5228 
5229 #ifndef PRODUCT
5230   if (_method != nullptr && should_print_igv(1)) {
5231     _igv_printer->end_method();
5232   }
5233 #endif
5234 }
5235 
5236 bool Compile::should_print_phase(CompilerPhaseType cpt) {
5237 #ifndef PRODUCT
5238   if (_directive->should_print_phase(cpt)) {
5239     return true;
5240   }
5241 #endif
5242   return false;
5243 }
5244 
5245 bool Compile::should_print_igv(const int level) {
5246 #ifndef PRODUCT
5247   if (PrintIdealGraphLevel < 0) { // disabled by the user
5248     return false;
5249   }
5250 
5251   bool need = directive()->IGVPrintLevelOption >= level;
5252   if (need && !_igv_printer) {
5253     _igv_printer = IdealGraphPrinter::printer();
5254     _igv_printer->set_compile(this);
5255   }
5256   return need;
5257 #else
5258   return false;
5259 #endif
5260 }
5261 
5262 #ifndef PRODUCT
5263 IdealGraphPrinter* Compile::_debug_file_printer = nullptr;
5264 IdealGraphPrinter* Compile::_debug_network_printer = nullptr;
5265 
5266 // Called from debugger. Prints method to the default file with the default phase name.
5267 // This works regardless of any Ideal Graph Visualizer flags set or not.
5268 void igv_print() {
5269   Compile::current()->igv_print_method_to_file();
5270 }
5271 
5272 // Same as igv_print() above but with a specified phase name.
5273 void igv_print(const char* phase_name) {
5274   Compile::current()->igv_print_method_to_file(phase_name);
5275 }
5276 
5277 // Called from debugger. Prints method with the default phase name to the default network or the one specified with
5278 // the network flags for the Ideal Graph Visualizer, or to the default file depending on the 'network' argument.
5279 // This works regardless of any Ideal Graph Visualizer flags set or not.
5280 void igv_print(bool network) {
5281   if (network) {
5282     Compile::current()->igv_print_method_to_network();
5283   } else {
5284     Compile::current()->igv_print_method_to_file();
5285   }
5286 }
5287 
5288 // Same as igv_print(bool network) above but with a specified phase name.
5289 void igv_print(bool network, const char* phase_name) {
5290   if (network) {
5291     Compile::current()->igv_print_method_to_network(phase_name);
5292   } else {
5293     Compile::current()->igv_print_method_to_file(phase_name);
5294   }
5295 }
5296 
5297 // Called from debugger. Normal write to the default _printer. Only works if Ideal Graph Visualizer printing flags are set.
5298 void igv_print_default() {
5299   Compile::current()->print_method(PHASE_DEBUG, 0);
5300 }
5301 
5302 // Called from debugger, especially when replaying a trace in which the program state cannot be altered like with rr replay.
5303 // A method is appended to an existing default file with the default phase name. This means that igv_append() must follow
5304 // an earlier igv_print(*) call which sets up the file. This works regardless of any Ideal Graph Visualizer flags set or not.
5305 void igv_append() {
5306   Compile::current()->igv_print_method_to_file("Debug", true);
5307 }
5308 
5309 // Same as igv_append() above but with a specified phase name.
5310 void igv_append(const char* phase_name) {
5311   Compile::current()->igv_print_method_to_file(phase_name, true);
5312 }
5313 
5314 void Compile::igv_print_method_to_file(const char* phase_name, bool append) {
5315   const char* file_name = "custom_debug.xml";
5316   if (_debug_file_printer == nullptr) {
5317     _debug_file_printer = new IdealGraphPrinter(C, file_name, append);
5318   } else {
5319     _debug_file_printer->update_compiled_method(C->method());
5320   }
5321   tty->print_cr("Method %s to %s", append ? "appended" : "printed", file_name);
5322   _debug_file_printer->print(phase_name, (Node*)C->root());
5323 }
5324 
5325 void Compile::igv_print_method_to_network(const char* phase_name) {
5326   if (_debug_network_printer == nullptr) {
5327     _debug_network_printer = new IdealGraphPrinter(C);
5328   } else {
5329     _debug_network_printer->update_compiled_method(C->method());
5330   }
5331   tty->print_cr("Method printed over network stream to IGV");
5332   _debug_network_printer->print(phase_name, (Node*)C->root());
5333 }
5334 #endif
5335 
5336 Node* Compile::narrow_value(BasicType bt, Node* value, const Type* type, PhaseGVN* phase, bool transform_res) {
5337   if (type != nullptr && phase->type(value)->higher_equal(type)) {
5338     return value;
5339   }
5340   Node* result = nullptr;
5341   if (bt == T_BYTE) {
5342     result = phase->transform(new LShiftINode(value, phase->intcon(24)));
5343     result = new RShiftINode(result, phase->intcon(24));
5344   } else if (bt == T_BOOLEAN) {
5345     result = new AndINode(value, phase->intcon(0xFF));
5346   } else if (bt == T_CHAR) {
5347     result = new AndINode(value,phase->intcon(0xFFFF));
5348   } else {
5349     assert(bt == T_SHORT, "unexpected narrow type");
5350     result = phase->transform(new LShiftINode(value, phase->intcon(16)));
5351     result = new RShiftINode(result, phase->intcon(16));
5352   }
5353   if (transform_res) {
5354     result = phase->transform(result);
5355   }
5356   return result;
5357 }
5358 
5359 void Compile::record_method_not_compilable_oom() {
5360   record_method_not_compilable(CompilationMemoryStatistic::failure_reason_memlimit());
5361 }