1 /*
   2  * Copyright (c) 1997, 2026, 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 "asm/macroAssembler.hpp"
  26 #include "asm/macroAssembler.inline.hpp"
  27 #include "ci/ciReplay.hpp"
  28 #include "classfile/javaClasses.hpp"
  29 #include "code/aotCodeCache.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/compiler_globals.hpp"
  37 #include "compiler/compilerDefinitions.hpp"
  38 #include "compiler/compilerOracle.hpp"
  39 #include "compiler/disassembler.hpp"
  40 #include "compiler/oopMap.hpp"
  41 #include "gc/shared/barrierSet.hpp"
  42 #include "gc/shared/c2/barrierSetC2.hpp"
  43 #include "jfr/jfrEvents.hpp"
  44 #include "jvm_io.h"
  45 #include "memory/allocation.hpp"
  46 #include "memory/arena.hpp"
  47 #include "memory/resourceArea.hpp"
  48 #include "opto/addnode.hpp"
  49 #include "opto/block.hpp"
  50 #include "opto/c2compiler.hpp"
  51 #include "opto/callGenerator.hpp"
  52 #include "opto/callnode.hpp"
  53 #include "opto/castnode.hpp"
  54 #include "opto/cfgnode.hpp"
  55 #include "opto/chaitin.hpp"
  56 #include "opto/compile.hpp"
  57 #include "opto/connode.hpp"
  58 #include "opto/convertnode.hpp"
  59 #include "opto/divnode.hpp"
  60 #include "opto/escape.hpp"
  61 #include "opto/idealGraphPrinter.hpp"
  62 #include "opto/locknode.hpp"
  63 #include "opto/loopnode.hpp"
  64 #include "opto/machnode.hpp"
  65 #include "opto/macro.hpp"
  66 #include "opto/matcher.hpp"
  67 #include "opto/mathexactnode.hpp"
  68 #include "opto/memnode.hpp"
  69 #include "opto/mulnode.hpp"
  70 #include "opto/narrowptrnode.hpp"
  71 #include "opto/node.hpp"
  72 #include "opto/opaquenode.hpp"
  73 #include "opto/opcodes.hpp"
  74 #include "opto/output.hpp"
  75 #include "opto/parse.hpp"
  76 #include "opto/phaseX.hpp"
  77 #include "opto/rootnode.hpp"
  78 #include "opto/runtime.hpp"
  79 #include "opto/stringopts.hpp"
  80 #include "opto/type.hpp"
  81 #include "opto/vector.hpp"
  82 #include "opto/vectornode.hpp"
  83 #include "runtime/globals_extension.hpp"
  84 #include "runtime/sharedRuntime.hpp"
  85 #include "runtime/signature.hpp"
  86 #include "runtime/stubRoutines.hpp"
  87 #include "runtime/timer.hpp"
  88 #include "utilities/align.hpp"
  89 #include "utilities/copy.hpp"
  90 #include "utilities/hashTable.hpp"
  91 #include "utilities/macros.hpp"
  92 
  93 // -------------------- Compile::mach_constant_base_node -----------------------
  94 // Constant table base node singleton.
  95 MachConstantBaseNode* Compile::mach_constant_base_node() {
  96   if (_mach_constant_base_node == nullptr) {
  97     _mach_constant_base_node = new MachConstantBaseNode();
  98     _mach_constant_base_node->add_req(C->root());
  99   }
 100   return _mach_constant_base_node;
 101 }
 102 
 103 
 104 /// Support for intrinsics.
 105 
 106 // Return the index at which m must be inserted (or already exists).
 107 // The sort order is by the address of the ciMethod, with is_virtual as minor key.
 108 class IntrinsicDescPair {
 109  private:
 110   ciMethod* _m;
 111   bool _is_virtual;
 112  public:
 113   IntrinsicDescPair(ciMethod* m, bool is_virtual) : _m(m), _is_virtual(is_virtual) {}
 114   static int compare(IntrinsicDescPair* const& key, CallGenerator* const& elt) {
 115     ciMethod* m= elt->method();
 116     ciMethod* key_m = key->_m;
 117     if (key_m < m)      return -1;
 118     else if (key_m > m) return 1;
 119     else {
 120       bool is_virtual = elt->is_virtual();
 121       bool key_virtual = key->_is_virtual;
 122       if (key_virtual < is_virtual)      return -1;
 123       else if (key_virtual > is_virtual) return 1;
 124       else                               return 0;
 125     }
 126   }
 127 };
 128 int Compile::intrinsic_insertion_index(ciMethod* m, bool is_virtual, bool& found) {
 129 #ifdef ASSERT
 130   for (int i = 1; i < _intrinsics.length(); i++) {
 131     CallGenerator* cg1 = _intrinsics.at(i-1);
 132     CallGenerator* cg2 = _intrinsics.at(i);
 133     assert(cg1->method() != cg2->method()
 134            ? cg1->method()     < cg2->method()
 135            : cg1->is_virtual() < cg2->is_virtual(),
 136            "compiler intrinsics list must stay sorted");
 137   }
 138 #endif
 139   IntrinsicDescPair pair(m, is_virtual);
 140   return _intrinsics.find_sorted<IntrinsicDescPair*, IntrinsicDescPair::compare>(&pair, found);
 141 }
 142 
 143 void Compile::register_intrinsic(CallGenerator* cg) {
 144   bool found = false;
 145   int index = intrinsic_insertion_index(cg->method(), cg->is_virtual(), found);
 146   assert(!found, "registering twice");
 147   _intrinsics.insert_before(index, cg);
 148   assert(find_intrinsic(cg->method(), cg->is_virtual()) == cg, "registration worked");
 149 }
 150 
 151 CallGenerator* Compile::find_intrinsic(ciMethod* m, bool is_virtual) {
 152   assert(m->is_loaded(), "don't try this on unloaded methods");
 153   if (_intrinsics.length() > 0) {
 154     bool found = false;
 155     int index = intrinsic_insertion_index(m, is_virtual, found);
 156      if (found) {
 157       return _intrinsics.at(index);
 158     }
 159   }
 160   // Lazily create intrinsics for intrinsic IDs well-known in the runtime.
 161   if (m->intrinsic_id() != vmIntrinsics::_none &&
 162       m->intrinsic_id() <= vmIntrinsics::LAST_COMPILER_INLINE) {
 163     CallGenerator* cg = make_vm_intrinsic(m, is_virtual);
 164     if (cg != nullptr) {
 165       // Save it for next time:
 166       register_intrinsic(cg);
 167       return cg;
 168     } else {
 169       gather_intrinsic_statistics(m->intrinsic_id(), is_virtual, _intrinsic_disabled);
 170     }
 171   }
 172   return nullptr;
 173 }
 174 
 175 // Compile::make_vm_intrinsic is defined in library_call.cpp.
 176 
 177 #ifndef PRODUCT
 178 // statistics gathering...
 179 
 180 juint  Compile::_intrinsic_hist_count[vmIntrinsics::number_of_intrinsics()] = {0};
 181 jubyte Compile::_intrinsic_hist_flags[vmIntrinsics::number_of_intrinsics()] = {0};
 182 
 183 inline int as_int(vmIntrinsics::ID id) {
 184   return vmIntrinsics::as_int(id);
 185 }
 186 
 187 bool Compile::gather_intrinsic_statistics(vmIntrinsics::ID id, bool is_virtual, int flags) {
 188   assert(id > vmIntrinsics::_none && id < vmIntrinsics::ID_LIMIT, "oob");
 189   int oflags = _intrinsic_hist_flags[as_int(id)];
 190   assert(flags != 0, "what happened?");
 191   if (is_virtual) {
 192     flags |= _intrinsic_virtual;
 193   }
 194   bool changed = (flags != oflags);
 195   if ((flags & _intrinsic_worked) != 0) {
 196     juint count = (_intrinsic_hist_count[as_int(id)] += 1);
 197     if (count == 1) {
 198       changed = true;           // first time
 199     }
 200     // increment the overall count also:
 201     _intrinsic_hist_count[as_int(vmIntrinsics::_none)] += 1;
 202   }
 203   if (changed) {
 204     if (((oflags ^ flags) & _intrinsic_virtual) != 0) {
 205       // Something changed about the intrinsic's virtuality.
 206       if ((flags & _intrinsic_virtual) != 0) {
 207         // This is the first use of this intrinsic as a virtual call.
 208         if (oflags != 0) {
 209           // We already saw it as a non-virtual, so note both cases.
 210           flags |= _intrinsic_both;
 211         }
 212       } else if ((oflags & _intrinsic_both) == 0) {
 213         // This is the first use of this intrinsic as a non-virtual
 214         flags |= _intrinsic_both;
 215       }
 216     }
 217     _intrinsic_hist_flags[as_int(id)] = (jubyte) (oflags | flags);
 218   }
 219   // update the overall flags also:
 220   _intrinsic_hist_flags[as_int(vmIntrinsics::_none)] |= (jubyte) flags;
 221   return changed;
 222 }
 223 
 224 static char* format_flags(int flags, char* buf) {
 225   buf[0] = 0;
 226   if ((flags & Compile::_intrinsic_worked) != 0)    strcat(buf, ",worked");
 227   if ((flags & Compile::_intrinsic_failed) != 0)    strcat(buf, ",failed");
 228   if ((flags & Compile::_intrinsic_disabled) != 0)  strcat(buf, ",disabled");
 229   if ((flags & Compile::_intrinsic_virtual) != 0)   strcat(buf, ",virtual");
 230   if ((flags & Compile::_intrinsic_both) != 0)      strcat(buf, ",nonvirtual");
 231   if (buf[0] == 0)  strcat(buf, ",");
 232   assert(buf[0] == ',', "must be");
 233   return &buf[1];
 234 }
 235 
 236 void Compile::print_intrinsic_statistics() {
 237   char flagsbuf[100];
 238   ttyLocker ttyl;
 239   if (xtty != nullptr)  xtty->head("statistics type='intrinsic'");
 240   tty->print_cr("Compiler intrinsic usage:");
 241   juint total = _intrinsic_hist_count[as_int(vmIntrinsics::_none)];
 242   if (total == 0)  total = 1;  // avoid div0 in case of no successes
 243   #define PRINT_STAT_LINE(name, c, f) \
 244     tty->print_cr("  %4d (%4.1f%%) %s (%s)", (int)(c), ((c) * 100.0) / total, name, f);
 245   for (auto id : EnumRange<vmIntrinsicID>{}) {
 246     int   flags = _intrinsic_hist_flags[as_int(id)];
 247     juint count = _intrinsic_hist_count[as_int(id)];
 248     if ((flags | count) != 0) {
 249       PRINT_STAT_LINE(vmIntrinsics::name_at(id), count, format_flags(flags, flagsbuf));
 250     }
 251   }
 252   PRINT_STAT_LINE("total", total, format_flags(_intrinsic_hist_flags[as_int(vmIntrinsics::_none)], flagsbuf));
 253   if (xtty != nullptr)  xtty->tail("statistics");
 254 }
 255 
 256 void Compile::print_statistics() {
 257   { ttyLocker ttyl;
 258     if (xtty != nullptr)  xtty->head("statistics type='opto'");
 259     Parse::print_statistics();
 260     PhaseStringOpts::print_statistics();
 261     PhaseCCP::print_statistics();
 262     PhaseRegAlloc::print_statistics();
 263     PhaseOutput::print_statistics();
 264     PhasePeephole::print_statistics();
 265     PhaseIdealLoop::print_statistics();
 266     ConnectionGraph::print_statistics();
 267     PhaseMacroExpand::print_statistics();
 268     if (xtty != nullptr)  xtty->tail("statistics");
 269   }
 270   if (_intrinsic_hist_flags[as_int(vmIntrinsics::_none)] != 0) {
 271     // put this under its own <statistics> element.
 272     print_intrinsic_statistics();
 273   }
 274 }
 275 #endif //PRODUCT
 276 
 277 void Compile::gvn_replace_by(Node* n, Node* nn) {
 278   for (DUIterator_Last imin, i = n->last_outs(imin); i >= imin; ) {
 279     Node* use = n->last_out(i);
 280     bool is_in_table = initial_gvn()->hash_delete(use);
 281     uint uses_found = 0;
 282     for (uint j = 0; j < use->len(); j++) {
 283       if (use->in(j) == n) {
 284         if (j < use->req())
 285           use->set_req(j, nn);
 286         else
 287           use->set_prec(j, nn);
 288         uses_found++;
 289       }
 290     }
 291     if (is_in_table) {
 292       // reinsert into table
 293       initial_gvn()->hash_find_insert(use);
 294     }
 295     record_for_igvn(use);
 296     PhaseIterGVN::add_users_of_use_to_worklist(nn, use, *_igvn_worklist);
 297     i -= uses_found;    // we deleted 1 or more copies of this edge
 298   }
 299 }
 300 
 301 
 302 // Identify all nodes that are reachable from below, useful.
 303 // Use breadth-first pass that records state in a Unique_Node_List,
 304 // recursive traversal is slower.
 305 void Compile::identify_useful_nodes(Unique_Node_List &useful) {
 306   int estimated_worklist_size = live_nodes();
 307   useful.map( estimated_worklist_size, nullptr );  // preallocate space
 308 
 309   // Initialize worklist
 310   if (root() != nullptr)  { useful.push(root()); }
 311   // If 'top' is cached, declare it useful to preserve cached node
 312   if (cached_top_node())  { useful.push(cached_top_node()); }
 313 
 314   // Push all useful nodes onto the list, breadthfirst
 315   for( uint next = 0; next < useful.size(); ++next ) {
 316     assert( next < unique(), "Unique useful nodes < total nodes");
 317     Node *n  = useful.at(next);
 318     uint max = n->len();
 319     for( uint i = 0; i < max; ++i ) {
 320       Node *m = n->in(i);
 321       if (not_a_node(m))  continue;
 322       useful.push(m);
 323     }
 324   }
 325 }
 326 
 327 // Update dead_node_list with any missing dead nodes using useful
 328 // list. Consider all non-useful nodes to be useless i.e., dead nodes.
 329 void Compile::update_dead_node_list(Unique_Node_List &useful) {
 330   uint max_idx = unique();
 331   VectorSet& useful_node_set = useful.member_set();
 332 
 333   for (uint node_idx = 0; node_idx < max_idx; node_idx++) {
 334     // If node with index node_idx is not in useful set,
 335     // mark it as dead in dead node list.
 336     if (!useful_node_set.test(node_idx)) {
 337       record_dead_node(node_idx);
 338     }
 339   }
 340 }
 341 
 342 void Compile::remove_useless_late_inlines(GrowableArray<CallGenerator*>* inlines, Unique_Node_List &useful) {
 343   int shift = 0;
 344   for (int i = 0; i < inlines->length(); i++) {
 345     CallGenerator* cg = inlines->at(i);
 346     if (useful.member(cg->call_node())) {
 347       if (shift > 0) {
 348         inlines->at_put(i - shift, cg);
 349       }
 350     } else {
 351       shift++; // skip over the dead element
 352     }
 353   }
 354   if (shift > 0) {
 355     inlines->trunc_to(inlines->length() - shift); // remove last elements from compacted array
 356   }
 357 }
 358 
 359 void Compile::remove_useless_late_inlines(GrowableArray<CallGenerator*>* inlines, Node* dead) {
 360   assert(dead != nullptr && dead->is_Call(), "sanity");
 361   int found = 0;
 362   for (int i = 0; i < inlines->length(); i++) {
 363     if (inlines->at(i)->call_node() == dead) {
 364       inlines->remove_at(i);
 365       found++;
 366       NOT_DEBUG( break; ) // elements are unique, so exit early
 367     }
 368   }
 369   assert(found <= 1, "not unique");
 370 }
 371 
 372 template<typename N, ENABLE_IF_SDEFN(std::is_base_of<Node, N>::value)>
 373 void Compile::remove_useless_nodes(GrowableArray<N*>& node_list, Unique_Node_List& useful) {
 374   for (int i = node_list.length() - 1; i >= 0; i--) {
 375     N* node = node_list.at(i);
 376     if (!useful.member(node)) {
 377       node_list.delete_at(i); // replaces i-th with last element which is known to be useful (already processed)
 378     }
 379   }
 380 }
 381 
 382 void Compile::remove_useless_node(Node* dead) {
 383   remove_modified_node(dead);
 384 
 385   // Constant node that has no out-edges and has only one in-edge from
 386   // root is usually dead. However, sometimes reshaping walk makes
 387   // it reachable by adding use edges. So, we will NOT count Con nodes
 388   // as dead to be conservative about the dead node count at any
 389   // given time.
 390   if (!dead->is_Con()) {
 391     record_dead_node(dead->_idx);
 392   }
 393   if (dead->is_macro()) {
 394     remove_macro_node(dead);
 395   }
 396   if (dead->is_expensive()) {
 397     remove_expensive_node(dead);
 398   }
 399   if (dead->is_OpaqueTemplateAssertionPredicate()) {
 400     remove_template_assertion_predicate_opaque(dead->as_OpaqueTemplateAssertionPredicate());
 401   }
 402   if (dead->is_ParsePredicate()) {
 403     remove_parse_predicate(dead->as_ParsePredicate());
 404   }
 405   if (dead->for_post_loop_opts_igvn()) {
 406     remove_from_post_loop_opts_igvn(dead);
 407   }
 408   if (dead->for_merge_stores_igvn()) {
 409     remove_from_merge_stores_igvn(dead);
 410   }
 411   if (dead->is_Call()) {
 412     remove_useless_late_inlines(                &_late_inlines, dead);
 413     remove_useless_late_inlines(         &_string_late_inlines, dead);
 414     remove_useless_late_inlines(         &_boxing_late_inlines, dead);
 415     remove_useless_late_inlines(&_vector_reboxing_late_inlines, dead);
 416 
 417     if (dead->is_CallStaticJava()) {
 418       remove_unstable_if_trap(dead->as_CallStaticJava(), false);
 419     }
 420   }
 421   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 422   bs->unregister_potential_barrier_node(dead);
 423 }
 424 
 425 // Disconnect all useless nodes by disconnecting those at the boundary.
 426 void Compile::disconnect_useless_nodes(Unique_Node_List& useful, Unique_Node_List& worklist, const Unique_Node_List* root_and_safepoints) {
 427   uint next = 0;
 428   while (next < useful.size()) {
 429     Node *n = useful.at(next++);
 430     if (n->is_SafePoint()) {
 431       // We're done with a parsing phase. Replaced nodes are not valid
 432       // beyond that point.
 433       n->as_SafePoint()->delete_replaced_nodes();
 434     }
 435     // Use raw traversal of out edges since this code removes out edges
 436     int max = n->outcnt();
 437     for (int j = 0; j < max; ++j) {
 438       Node* child = n->raw_out(j);
 439       if (!useful.member(child)) {
 440         assert(!child->is_top() || child != top(),
 441                "If top is cached in Compile object it is in useful list");
 442         // Only need to remove this out-edge to the useless node
 443         n->raw_del_out(j);
 444         --j;
 445         --max;
 446         if (child->is_data_proj_of_pure_function(n)) {
 447           worklist.push(n);
 448         }
 449       }
 450     }
 451     if (n->outcnt() == 1 && n->has_special_unique_user()) {
 452       assert(useful.member(n->unique_out()), "do not push a useless node");
 453       worklist.push(n->unique_out());
 454     }
 455   }
 456 
 457   remove_useless_nodes(_macro_nodes,        useful); // remove useless macro nodes
 458   remove_useless_nodes(_parse_predicates,   useful); // remove useless Parse Predicate nodes
 459   // Remove useless Template Assertion Predicate opaque nodes
 460   remove_useless_nodes(_template_assertion_predicate_opaques, useful);
 461   remove_useless_nodes(_expensive_nodes,    useful); // remove useless expensive nodes
 462   remove_useless_nodes(_for_post_loop_igvn, useful); // remove useless node recorded for post loop opts IGVN pass
 463   remove_useless_nodes(_for_merge_stores_igvn, useful); // remove useless node recorded for merge stores IGVN pass
 464   remove_useless_unstable_if_traps(useful);          // remove useless unstable_if traps
 465   remove_useless_coarsened_locks(useful);            // remove useless coarsened locks nodes
 466 #ifdef ASSERT
 467   if (_modified_nodes != nullptr) {
 468     _modified_nodes->remove_useless_nodes(useful.member_set());
 469   }
 470 #endif
 471 
 472   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 473   bs->eliminate_useless_gc_barriers(useful, this);
 474   // clean up the late inline lists
 475   remove_useless_late_inlines(                &_late_inlines, useful);
 476   remove_useless_late_inlines(         &_string_late_inlines, useful);
 477   remove_useless_late_inlines(         &_boxing_late_inlines, useful);
 478   remove_useless_late_inlines(&_vector_reboxing_late_inlines, useful);
 479   DEBUG_ONLY(verify_graph_edges(true /*check for no_dead_code*/, root_and_safepoints);)
 480 }
 481 
 482 // ============================================================================
 483 //------------------------------CompileWrapper---------------------------------
 484 class CompileWrapper : public StackObj {
 485   Compile *const _compile;
 486  public:
 487   CompileWrapper(Compile* compile);
 488 
 489   ~CompileWrapper();
 490 };
 491 
 492 CompileWrapper::CompileWrapper(Compile* compile) : _compile(compile) {
 493   // the Compile* pointer is stored in the current ciEnv:
 494   ciEnv* env = compile->env();
 495   assert(env == ciEnv::current(), "must already be a ciEnv active");
 496   assert(env->compiler_data() == nullptr, "compile already active?");
 497   env->set_compiler_data(compile);
 498   assert(compile == Compile::current(), "sanity");
 499 
 500   compile->set_type_dict(nullptr);
 501   compile->set_clone_map(new Dict(cmpkey, hashkey, _compile->comp_arena()));
 502   compile->clone_map().set_clone_idx(0);
 503   compile->set_type_last_size(0);
 504   compile->set_last_tf(nullptr, nullptr);
 505   compile->set_indexSet_arena(nullptr);
 506   compile->set_indexSet_free_block_list(nullptr);
 507   compile->init_type_arena();
 508   Type::Initialize(compile);
 509   _compile->begin_method();
 510   _compile->clone_map().set_debug(_compile->has_method() && _compile->directive()->CloneMapDebugOption);
 511 }
 512 CompileWrapper::~CompileWrapper() {
 513   // simulate crash during compilation
 514   assert(CICrashAt < 0 || _compile->compile_id() != CICrashAt, "just as planned");
 515 
 516   _compile->end_method();
 517   _compile->env()->set_compiler_data(nullptr);
 518 }
 519 
 520 
 521 //----------------------------print_compile_messages---------------------------
 522 void Compile::print_compile_messages() {
 523 #ifndef PRODUCT
 524   // Check if recompiling
 525   if (!subsume_loads() && PrintOpto) {
 526     // Recompiling without allowing machine instructions to subsume loads
 527     tty->print_cr("*********************************************************");
 528     tty->print_cr("** Bailout: Recompile without subsuming loads          **");
 529     tty->print_cr("*********************************************************");
 530   }
 531   if ((do_escape_analysis() != DoEscapeAnalysis) && PrintOpto) {
 532     // Recompiling without escape analysis
 533     tty->print_cr("*********************************************************");
 534     tty->print_cr("** Bailout: Recompile without escape analysis          **");
 535     tty->print_cr("*********************************************************");
 536   }
 537   if (do_iterative_escape_analysis() != DoEscapeAnalysis && PrintOpto) {
 538     // Recompiling without iterative escape analysis
 539     tty->print_cr("*********************************************************");
 540     tty->print_cr("** Bailout: Recompile without iterative escape analysis**");
 541     tty->print_cr("*********************************************************");
 542   }
 543   if (do_reduce_allocation_merges() != ReduceAllocationMerges && PrintOpto) {
 544     // Recompiling without reducing allocation merges
 545     tty->print_cr("*********************************************************");
 546     tty->print_cr("** Bailout: Recompile without reduce allocation merges **");
 547     tty->print_cr("*********************************************************");
 548   }
 549   if ((eliminate_boxing() != EliminateAutoBox) && PrintOpto) {
 550     // Recompiling without boxing elimination
 551     tty->print_cr("*********************************************************");
 552     tty->print_cr("** Bailout: Recompile without boxing elimination       **");
 553     tty->print_cr("*********************************************************");
 554   }
 555   if ((do_locks_coarsening() != EliminateLocks) && PrintOpto) {
 556     // Recompiling without locks coarsening
 557     tty->print_cr("*********************************************************");
 558     tty->print_cr("** Bailout: Recompile without locks coarsening         **");
 559     tty->print_cr("*********************************************************");
 560   }
 561   if (env()->break_at_compile()) {
 562     // Open the debugger when compiling this method.
 563     tty->print("### Breaking when compiling: ");
 564     method()->print_short_name();
 565     tty->cr();
 566     BREAKPOINT;
 567   }
 568 
 569   if( PrintOpto ) {
 570     if (is_osr_compilation()) {
 571       tty->print("[OSR]%3d", _compile_id);
 572     } else {
 573       tty->print("%3d", _compile_id);
 574     }
 575   }
 576 #endif
 577 }
 578 
 579 #ifndef PRODUCT
 580 void Compile::print_phase(const char* phase_name) {
 581   tty->print_cr("%u.\t%s", ++_phase_counter, phase_name);
 582 }
 583 
 584 void Compile::print_ideal_ir(const char* compile_phase_name) const {
 585   // keep the following output all in one block
 586   // This output goes directly to the tty, not the compiler log.
 587   // To enable tools to match it up with the compilation activity,
 588   // be sure to tag this tty output with the compile ID.
 589 
 590   // Node dumping can cause a safepoint, which can break the tty lock.
 591   // Buffer all node dumps, so that all safepoints happen before we lock.
 592   ResourceMark rm;
 593   stringStream ss;
 594 
 595   if (_output == nullptr) {
 596     ss.print_cr("AFTER: %s", compile_phase_name);
 597     // Print out all nodes in ascending order of index.
 598     // It is important that we traverse both inputs and outputs of nodes,
 599     // so that we reach all nodes that are connected to Root.
 600     root()->dump_bfs(MaxNodeLimit, nullptr, "-+S$", &ss);
 601   } else {
 602     // Dump the node blockwise if we have a scheduling
 603     _output->print_scheduling(&ss);
 604   }
 605 
 606   // Check that the lock is not broken by a safepoint.
 607   NoSafepointVerifier nsv;
 608   ttyLocker ttyl;
 609   if (xtty != nullptr) {
 610     xtty->head("ideal compile_id='%d'%s compile_phase='%s'",
 611                compile_id(),
 612                is_osr_compilation() ? " compile_kind='osr'" : "",
 613                compile_phase_name);
 614   }
 615 
 616   tty->print("%s", ss.as_string());
 617 
 618   if (xtty != nullptr) {
 619     xtty->tail("ideal");
 620   }
 621 }
 622 #endif
 623 
 624 // ============================================================================
 625 //------------------------------Compile standard-------------------------------
 626 
 627 // Compile a method.  entry_bci is -1 for normal compilations and indicates
 628 // the continuation bci for on stack replacement.
 629 
 630 
 631 Compile::Compile(ciEnv* ci_env, ciMethod* target, int osr_bci,
 632                  Options options, DirectiveSet* directive)
 633     : Phase(Compiler),
 634       _compile_id(ci_env->compile_id()),
 635       _options(options),
 636       _method(target),
 637       _entry_bci(osr_bci),
 638       _ilt(nullptr),
 639       _stub_function(nullptr),
 640       _stub_name(nullptr),
 641       _stub_id(StubId::NO_STUBID),
 642       _stub_entry_point(nullptr),
 643       _max_node_limit(MaxNodeLimit),
 644       _post_loop_opts_phase(false),
 645       _merge_stores_phase(false),
 646       _allow_macro_nodes(true),
 647       _inlining_progress(false),
 648       _inlining_incrementally(false),
 649       _do_cleanup(false),
 650       _has_reserved_stack_access(target->has_reserved_stack_access()),
 651 #ifndef PRODUCT
 652       _igv_idx(0),
 653       _trace_opto_output(directive->TraceOptoOutputOption),
 654 #endif
 655       _clinit_barrier_on_entry(false),
 656       _stress_seed(0),
 657       _comp_arena(mtCompiler, Arena::Tag::tag_comp),
 658       _barrier_set_state(BarrierSet::barrier_set()->barrier_set_c2()->create_barrier_state(comp_arena())),
 659       _env(ci_env),
 660       _directive(directive),
 661       _log(ci_env->log()),
 662       _first_failure_details(nullptr),
 663       _intrinsics(comp_arena(), 0, 0, nullptr),
 664       _macro_nodes(comp_arena(), 8, 0, nullptr),
 665       _parse_predicates(comp_arena(), 8, 0, nullptr),
 666       _template_assertion_predicate_opaques(comp_arena(), 8, 0, nullptr),
 667       _expensive_nodes(comp_arena(), 8, 0, nullptr),
 668       _for_post_loop_igvn(comp_arena(), 8, 0, nullptr),
 669       _for_merge_stores_igvn(comp_arena(), 8, 0, nullptr),
 670       _unstable_if_traps(comp_arena(), 8, 0, nullptr),
 671       _coarsened_locks(comp_arena(), 8, 0, nullptr),
 672       _congraph(nullptr),
 673       NOT_PRODUCT(_igv_printer(nullptr) COMMA)
 674       _unique(0),
 675       _dead_node_count(0),
 676       _dead_node_list(comp_arena()),
 677       _node_arena_one(mtCompiler, Arena::Tag::tag_node),
 678       _node_arena_two(mtCompiler, Arena::Tag::tag_node),
 679       _node_arena(&_node_arena_one),
 680       _mach_constant_base_node(nullptr),
 681       _Compile_types(mtCompiler, Arena::Tag::tag_type),
 682       _initial_gvn(nullptr),
 683       _igvn_worklist(nullptr),
 684       _types(nullptr),
 685       _node_hash(nullptr),
 686       _late_inlines(comp_arena(), 2, 0, nullptr),
 687       _string_late_inlines(comp_arena(), 2, 0, nullptr),
 688       _boxing_late_inlines(comp_arena(), 2, 0, nullptr),
 689       _vector_reboxing_late_inlines(comp_arena(), 2, 0, nullptr),
 690       _late_inlines_pos(0),
 691       _has_mh_late_inlines(false),
 692       _oom(false),
 693       _replay_inline_data(nullptr),
 694       _inline_printer(this),
 695       _java_calls(0),
 696       _inner_loops(0),
 697       _FIRST_STACK_mask(comp_arena()),
 698       _interpreter_frame_size(0),
 699       _regmask_arena(mtCompiler, Arena::Tag::tag_regmask),
 700       _output(nullptr)
 701 #ifndef PRODUCT
 702       ,
 703       _in_dump_cnt(0)
 704 #endif
 705 {
 706   C = this;
 707   CompileWrapper cw(this);
 708 
 709   TraceTime t1("Total compilation time", &_t_totalCompilation, CITime, CITimeVerbose);
 710   TraceTime t2(nullptr, &_t_methodCompilation, CITime, false);
 711 
 712 #if defined(SUPPORT_ASSEMBLY) || defined(SUPPORT_ABSTRACT_ASSEMBLY)
 713   bool print_opto_assembly = directive->PrintOptoAssemblyOption;
 714   // We can always print a disassembly, either abstract (hex dump) or
 715   // with the help of a suitable hsdis library. Thus, we should not
 716   // couple print_assembly and print_opto_assembly controls.
 717   // But: always print opto and regular assembly on compile command 'print'.
 718   bool print_assembly = directive->PrintAssemblyOption;
 719   set_print_assembly(print_opto_assembly || print_assembly);
 720 #else
 721   set_print_assembly(false); // must initialize.
 722 #endif
 723 
 724 #ifndef PRODUCT
 725   set_parsed_irreducible_loop(false);
 726 #endif
 727 
 728   if (directive->ReplayInlineOption) {
 729     _replay_inline_data = ciReplay::load_inline_data(method(), entry_bci(), ci_env->comp_level());
 730   }
 731   set_print_inlining(directive->PrintInliningOption || PrintOptoInlining);
 732   set_print_intrinsics(directive->PrintIntrinsicsOption);
 733   set_has_irreducible_loop(true); // conservative until build_loop_tree() reset it
 734 
 735   if (ProfileTraps) {
 736     // Make sure the method being compiled gets its own MDO,
 737     // so we can at least track the decompile_count().
 738     method()->ensure_method_data();
 739   }
 740 
 741   if (StressLCM || StressGCM || StressIGVN || StressCCP ||
 742       StressIncrementalInlining || StressMacroExpansion ||
 743       StressMacroElimination || StressUnstableIfTraps ||
 744       StressBailout || StressLoopPeeling) {
 745     initialize_stress_seed(directive);
 746   }
 747 
 748   Init(/*do_aliasing=*/ true);
 749 
 750   print_compile_messages();
 751 
 752   _ilt = InlineTree::build_inline_tree_root();
 753 
 754   // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
 755   assert(num_alias_types() >= AliasIdxRaw, "");
 756 
 757 #define MINIMUM_NODE_HASH  1023
 758 
 759   // GVN that will be run immediately on new nodes
 760   uint estimated_size = method()->code_size()*4+64;
 761   estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
 762   _igvn_worklist = new (comp_arena()) Unique_Node_List(comp_arena());
 763   _types = new (comp_arena()) Type_Array(comp_arena());
 764   _node_hash = new (comp_arena()) NodeHash(comp_arena(), estimated_size);
 765   PhaseGVN gvn;
 766   set_initial_gvn(&gvn);
 767 
 768   { // Scope for timing the parser
 769     TracePhase tp(_t_parser);
 770 
 771     // Put top into the hash table ASAP.
 772     initial_gvn()->transform(top());
 773 
 774     // Set up tf(), start(), and find a CallGenerator.
 775     CallGenerator* cg = nullptr;
 776     if (is_osr_compilation()) {
 777       const TypeTuple *domain = StartOSRNode::osr_domain();
 778       const TypeTuple *range = TypeTuple::make_range(method()->signature());
 779       init_tf(TypeFunc::make(domain, range));
 780       StartNode* s = new StartOSRNode(root(), domain);
 781       initial_gvn()->set_type_bottom(s);
 782       verify_start(s);
 783       cg = CallGenerator::for_osr(method(), entry_bci());
 784     } else {
 785       // Normal case.
 786       init_tf(TypeFunc::make(method()));
 787       StartNode* s = new StartNode(root(), tf()->domain());
 788       initial_gvn()->set_type_bottom(s);
 789       verify_start(s);
 790       float past_uses = method()->interpreter_invocation_count();
 791       float expected_uses = past_uses;
 792       cg = CallGenerator::for_inline(method(), expected_uses);
 793     }
 794     if (failing())  return;
 795     if (cg == nullptr) {
 796       const char* reason = InlineTree::check_can_parse(method());
 797       assert(reason != nullptr, "expect reason for parse failure");
 798       stringStream ss;
 799       ss.print("cannot parse method: %s", reason);
 800       record_method_not_compilable(ss.as_string());
 801       return;
 802     }
 803 
 804     gvn.set_type(root(), root()->bottom_type());
 805 
 806     JVMState* jvms = build_start_state(start(), tf());
 807     if ((jvms = cg->generate(jvms)) == nullptr) {
 808       assert(failure_reason() != nullptr, "expect reason for parse failure");
 809       stringStream ss;
 810       ss.print("method parse failed: %s", failure_reason());
 811       record_method_not_compilable(ss.as_string() DEBUG_ONLY(COMMA true));
 812       return;
 813     }
 814     GraphKit kit(jvms);
 815 
 816     if (!kit.stopped()) {
 817       // Accept return values, and transfer control we know not where.
 818       // This is done by a special, unique ReturnNode bound to root.
 819       return_values(kit.jvms());
 820     }
 821 
 822     if (kit.has_exceptions()) {
 823       // Any exceptions that escape from this call must be rethrown
 824       // to whatever caller is dynamically above us on the stack.
 825       // This is done by a special, unique RethrowNode bound to root.
 826       rethrow_exceptions(kit.transfer_exceptions_into_jvms());
 827     }
 828 
 829     assert(IncrementalInline || (_late_inlines.length() == 0 && !has_mh_late_inlines()), "incremental inlining is off");
 830 
 831     if (_late_inlines.length() == 0 && !has_mh_late_inlines() && !failing() && has_stringbuilder()) {
 832       inline_string_calls(true);
 833     }
 834 
 835     if (failing())  return;
 836 
 837     // Remove clutter produced by parsing.
 838     if (!failing()) {
 839       ResourceMark rm;
 840       PhaseRemoveUseless pru(initial_gvn(), *igvn_worklist());
 841     }
 842   }
 843 
 844   // Note:  Large methods are capped off in do_one_bytecode().
 845   if (failing())  return;
 846 
 847   // After parsing, node notes are no longer automagic.
 848   // They must be propagated by register_new_node_with_optimizer(),
 849   // clone(), or the like.
 850   set_default_node_notes(nullptr);
 851 
 852 #ifndef PRODUCT
 853   if (should_print_igv(1)) {
 854     _igv_printer->print_inlining();
 855   }
 856 #endif
 857 
 858   if (failing())  return;
 859   NOT_PRODUCT( verify_graph_edges(); )
 860 
 861   // Now optimize
 862   Optimize();
 863   if (failing())  return;
 864   NOT_PRODUCT( verify_graph_edges(); )
 865 
 866 #ifndef PRODUCT
 867   if (should_print_ideal()) {
 868     print_ideal_ir("PrintIdeal");
 869   }
 870 #endif
 871 
 872 #ifdef ASSERT
 873   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 874   bs->verify_gc_barriers(this, BarrierSetC2::BeforeCodeGen);
 875 #endif
 876 
 877   // Dump compilation data to replay it.
 878   if (directive->DumpReplayOption) {
 879     env()->dump_replay_data(_compile_id);
 880   }
 881   if (directive->DumpInlineOption && (ilt() != nullptr)) {
 882     env()->dump_inline_data(_compile_id);
 883   }
 884 
 885   // Now that we know the size of all the monitors we can add the fixed slots
 886   // for GC barriers and the original deopt pc. All these slots should be able
 887   // to fit an address.
 888   int reserved_gc_slots = BarrierSet::barrier_set()->barrier_set_c2()->reserved_slots();
 889   int next_slot = fixed_slots() + (reserved_gc_slots + 1) * sizeof(address) / VMRegImpl::stack_slot_size;
 890   set_fixed_slots(next_slot);
 891 
 892   // Compute when to use implicit null checks. Used by matching trap based
 893   // nodes and NullCheck optimization.
 894   set_allowed_deopt_reasons();
 895 
 896   // Now generate code
 897   Code_Gen();
 898 }
 899 
 900 //------------------------------Compile----------------------------------------
 901 // Compile a runtime stub
 902 Compile::Compile(ciEnv* ci_env,
 903                  TypeFunc_generator generator,
 904                  address stub_function,
 905                  const char* stub_name,
 906                  StubId stub_id,
 907                  int is_fancy_jump,
 908                  bool pass_tls,
 909                  bool return_pc,
 910                  DirectiveSet* directive)
 911     : Phase(Compiler),
 912       _compile_id(0),
 913       _options(Options::for_runtime_stub()),
 914       _method(nullptr),
 915       _entry_bci(InvocationEntryBci),
 916       _stub_function(stub_function),
 917       _stub_name(stub_name),
 918       _stub_id(stub_id),
 919       _stub_entry_point(nullptr),
 920       _max_node_limit(MaxNodeLimit),
 921       _post_loop_opts_phase(false),
 922       _merge_stores_phase(false),
 923       _allow_macro_nodes(true),
 924       _inlining_progress(false),
 925       _inlining_incrementally(false),
 926       _has_reserved_stack_access(false),
 927 #ifndef PRODUCT
 928       _igv_idx(0),
 929       _trace_opto_output(directive->TraceOptoOutputOption),
 930 #endif
 931       _clinit_barrier_on_entry(false),
 932       _stress_seed(0),
 933       _comp_arena(mtCompiler, Arena::Tag::tag_comp),
 934       _barrier_set_state(BarrierSet::barrier_set()->barrier_set_c2()->create_barrier_state(comp_arena())),
 935       _env(ci_env),
 936       _directive(directive),
 937       _log(ci_env->log()),
 938       _first_failure_details(nullptr),
 939       _for_post_loop_igvn(comp_arena(), 8, 0, nullptr),
 940       _for_merge_stores_igvn(comp_arena(), 8, 0, nullptr),
 941       _congraph(nullptr),
 942       NOT_PRODUCT(_igv_printer(nullptr) COMMA)
 943       _unique(0),
 944       _dead_node_count(0),
 945       _dead_node_list(comp_arena()),
 946       _node_arena_one(mtCompiler, Arena::Tag::tag_node),
 947       _node_arena_two(mtCompiler, Arena::Tag::tag_node),
 948       _node_arena(&_node_arena_one),
 949       _mach_constant_base_node(nullptr),
 950       _Compile_types(mtCompiler, Arena::Tag::tag_type),
 951       _initial_gvn(nullptr),
 952       _igvn_worklist(nullptr),
 953       _types(nullptr),
 954       _node_hash(nullptr),
 955       _has_mh_late_inlines(false),
 956       _oom(false),
 957       _replay_inline_data(nullptr),
 958       _inline_printer(this),
 959       _java_calls(0),
 960       _inner_loops(0),
 961       _FIRST_STACK_mask(comp_arena()),
 962       _interpreter_frame_size(0),
 963       _regmask_arena(mtCompiler, Arena::Tag::tag_regmask),
 964       _output(nullptr),
 965 #ifndef PRODUCT
 966       _in_dump_cnt(0),
 967 #endif
 968       _allowed_reasons(0) {
 969   C = this;
 970 
 971   // try to reuse an existing stub
 972   {
 973     BlobId blob_id = StubInfo::blob(_stub_id);
 974     CodeBlob* blob = AOTCodeCache::load_code_blob(AOTCodeEntry::C2Blob, blob_id);
 975     if (blob != nullptr) {
 976       RuntimeStub* rs = blob->as_runtime_stub();
 977       _stub_entry_point = rs->entry_point();
 978       return;
 979     }
 980   }
 981 
 982   TraceTime t1(nullptr, &_t_totalCompilation, CITime, false);
 983   TraceTime t2(nullptr, &_t_stubCompilation, CITime, false);
 984 
 985 #ifndef PRODUCT
 986   set_print_assembly(PrintFrameConverterAssembly);
 987   set_parsed_irreducible_loop(false);
 988 #else
 989   set_print_assembly(false); // Must initialize.
 990 #endif
 991   set_has_irreducible_loop(false); // no loops
 992 
 993   CompileWrapper cw(this);
 994   Init(/*do_aliasing=*/ false);
 995   init_tf((*generator)());
 996 
 997   _igvn_worklist = new (comp_arena()) Unique_Node_List(comp_arena());
 998   _types = new (comp_arena()) Type_Array(comp_arena());
 999   _node_hash = new (comp_arena()) NodeHash(comp_arena(), 255);
1000 
1001   if (StressLCM || StressGCM || StressBailout) {
1002     initialize_stress_seed(directive);
1003   }
1004 
1005   {
1006     PhaseGVN gvn;
1007     set_initial_gvn(&gvn);    // not significant, but GraphKit guys use it pervasively
1008     gvn.transform(top());
1009 
1010     GraphKit kit;
1011     kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
1012   }
1013 
1014   NOT_PRODUCT( verify_graph_edges(); )
1015 
1016   Code_Gen();
1017 }
1018 
1019 Compile::~Compile() {
1020   delete _first_failure_details;
1021 };
1022 
1023 //------------------------------Init-------------------------------------------
1024 // Prepare for a single compilation
1025 void Compile::Init(bool aliasing) {
1026   _do_aliasing = aliasing;
1027   _unique  = 0;
1028   _regalloc = nullptr;
1029 
1030   _tf      = nullptr;  // filled in later
1031   _top     = nullptr;  // cached later
1032   _matcher = nullptr;  // filled in later
1033   _cfg     = nullptr;  // filled in later
1034 
1035   _node_note_array = nullptr;
1036   _default_node_notes = nullptr;
1037   DEBUG_ONLY( _modified_nodes = nullptr; ) // Used in Optimize()
1038 
1039   _immutable_memory = nullptr; // filled in at first inquiry
1040 
1041 #ifdef ASSERT
1042   _phase_optimize_finished = false;
1043   _phase_verify_ideal_loop = false;
1044   _exception_backedge = false;
1045   _type_verify = nullptr;
1046 #endif
1047 
1048   // Globally visible Nodes
1049   // First set TOP to null to give safe behavior during creation of RootNode
1050   set_cached_top_node(nullptr);
1051   set_root(new RootNode());
1052   // Now that you have a Root to point to, create the real TOP
1053   set_cached_top_node( new ConNode(Type::TOP) );
1054   set_recent_alloc(nullptr, nullptr);
1055 
1056   // Create Debug Information Recorder to record scopes, oopmaps, etc.
1057   env()->set_oop_recorder(new OopRecorder(env()->arena()));
1058   env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
1059   env()->set_dependencies(new Dependencies(env()));
1060 
1061   _fixed_slots = 0;
1062   set_has_split_ifs(false);
1063   set_has_loops(false); // first approximation
1064   set_has_stringbuilder(false);
1065   set_has_boxed_value(false);
1066   _trap_can_recompile = false;  // no traps emitted yet
1067   _major_progress = true; // start out assuming good things will happen
1068   set_has_unsafe_access(false);
1069   set_max_vector_size(0);
1070   set_clear_upper_avx(false);  //false as default for clear upper bits of ymm registers
1071   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
1072   set_decompile_count(0);
1073 
1074 #ifndef PRODUCT
1075   _phase_counter = 0;
1076   Copy::zero_to_bytes(_igv_phase_iter, sizeof(_igv_phase_iter));
1077 #endif
1078 
1079   set_do_freq_based_layout(_directive->BlockLayoutByFrequencyOption);
1080   _loop_opts_cnt = LoopOptsCount;
1081   set_do_inlining(Inline);
1082   set_max_inline_size(MaxInlineSize);
1083   set_freq_inline_size(FreqInlineSize);
1084   set_do_scheduling(OptoScheduling);
1085 
1086   set_do_vector_loop(false);
1087   set_has_monitors(false);
1088   set_has_scoped_access(false);
1089 
1090   if (AllowVectorizeOnDemand) {
1091     if (has_method() && _directive->VectorizeOption) {
1092       set_do_vector_loop(true);
1093       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());})
1094     } else if (has_method() && method()->name() != nullptr &&
1095                method()->intrinsic_id() == vmIntrinsics::_forEachRemaining) {
1096       set_do_vector_loop(true);
1097     }
1098   }
1099   set_use_cmove(UseCMoveUnconditionally /* || do_vector_loop()*/); //TODO: consider do_vector_loop() mandate use_cmove unconditionally
1100   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());})
1101 
1102   _max_node_limit = _directive->MaxNodeLimitOption;
1103 
1104   if (VM_Version::supports_fast_class_init_checks() && has_method() && !is_osr_compilation() && method()->needs_clinit_barrier()) {
1105     set_clinit_barrier_on_entry(true);
1106   }
1107   if (debug_info()->recording_non_safepoints()) {
1108     set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
1109                         (comp_arena(), 8, 0, nullptr));
1110     set_default_node_notes(Node_Notes::make(this));
1111   }
1112 
1113   const int grow_ats = 16;
1114   _max_alias_types = grow_ats;
1115   _alias_types   = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
1116   AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType,  grow_ats);
1117   Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
1118   {
1119     for (int i = 0; i < grow_ats; i++)  _alias_types[i] = &ats[i];
1120   }
1121   // Initialize the first few types.
1122   _alias_types[AliasIdxTop]->Init(AliasIdxTop, nullptr);
1123   _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
1124   _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
1125   _num_alias_types = AliasIdxRaw+1;
1126   // Zero out the alias type cache.
1127   Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
1128   // A null adr_type hits in the cache right away.  Preload the right answer.
1129   probe_alias_cache(nullptr)->_index = AliasIdxTop;
1130 }
1131 
1132 #ifdef ASSERT
1133 // Verify that the current StartNode is valid.
1134 void Compile::verify_start(StartNode* s) const {
1135   assert(failing_internal() || s == start(), "should be StartNode");
1136 }
1137 #endif
1138 
1139 /**
1140  * Return the 'StartNode'. We must not have a pending failure, since the ideal graph
1141  * can be in an inconsistent state, i.e., we can get segmentation faults when traversing
1142  * the ideal graph.
1143  */
1144 StartNode* Compile::start() const {
1145   assert (!failing_internal() || C->failure_is_artificial(), "Must not have pending failure. Reason is: %s", failure_reason());
1146   for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
1147     Node* start = root()->fast_out(i);
1148     if (start->is_Start()) {
1149       return start->as_Start();
1150     }
1151   }
1152   fatal("Did not find Start node!");
1153   return nullptr;
1154 }
1155 
1156 //-------------------------------immutable_memory-------------------------------------
1157 // Access immutable memory
1158 Node* Compile::immutable_memory() {
1159   if (_immutable_memory != nullptr) {
1160     return _immutable_memory;
1161   }
1162   StartNode* s = start();
1163   for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
1164     Node *p = s->fast_out(i);
1165     if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
1166       _immutable_memory = p;
1167       return _immutable_memory;
1168     }
1169   }
1170   ShouldNotReachHere();
1171   return nullptr;
1172 }
1173 
1174 //----------------------set_cached_top_node------------------------------------
1175 // Install the cached top node, and make sure Node::is_top works correctly.
1176 void Compile::set_cached_top_node(Node* tn) {
1177   if (tn != nullptr)  verify_top(tn);
1178   Node* old_top = _top;
1179   _top = tn;
1180   // Calling Node::setup_is_top allows the nodes the chance to adjust
1181   // their _out arrays.
1182   if (_top != nullptr)     _top->setup_is_top();
1183   if (old_top != nullptr)  old_top->setup_is_top();
1184   assert(_top == nullptr || top()->is_top(), "");
1185 }
1186 
1187 #ifdef ASSERT
1188 uint Compile::count_live_nodes_by_graph_walk() {
1189   Unique_Node_List useful(comp_arena());
1190   // Get useful node list by walking the graph.
1191   identify_useful_nodes(useful);
1192   return useful.size();
1193 }
1194 
1195 void Compile::print_missing_nodes() {
1196 
1197   // Return if CompileLog is null and PrintIdealNodeCount is false.
1198   if ((_log == nullptr) && (! PrintIdealNodeCount)) {
1199     return;
1200   }
1201 
1202   // This is an expensive function. It is executed only when the user
1203   // specifies VerifyIdealNodeCount option or otherwise knows the
1204   // additional work that needs to be done to identify reachable nodes
1205   // by walking the flow graph and find the missing ones using
1206   // _dead_node_list.
1207 
1208   Unique_Node_List useful(comp_arena());
1209   // Get useful node list by walking the graph.
1210   identify_useful_nodes(useful);
1211 
1212   uint l_nodes = C->live_nodes();
1213   uint l_nodes_by_walk = useful.size();
1214 
1215   if (l_nodes != l_nodes_by_walk) {
1216     if (_log != nullptr) {
1217       _log->begin_head("mismatched_nodes count='%d'", abs((int) (l_nodes - l_nodes_by_walk)));
1218       _log->stamp();
1219       _log->end_head();
1220     }
1221     VectorSet& useful_member_set = useful.member_set();
1222     int last_idx = l_nodes_by_walk;
1223     for (int i = 0; i < last_idx; i++) {
1224       if (useful_member_set.test(i)) {
1225         if (_dead_node_list.test(i)) {
1226           if (_log != nullptr) {
1227             _log->elem("mismatched_node_info node_idx='%d' type='both live and dead'", i);
1228           }
1229           if (PrintIdealNodeCount) {
1230             // Print the log message to tty
1231               tty->print_cr("mismatched_node idx='%d' both live and dead'", i);
1232               useful.at(i)->dump();
1233           }
1234         }
1235       }
1236       else if (! _dead_node_list.test(i)) {
1237         if (_log != nullptr) {
1238           _log->elem("mismatched_node_info node_idx='%d' type='neither live nor dead'", i);
1239         }
1240         if (PrintIdealNodeCount) {
1241           // Print the log message to tty
1242           tty->print_cr("mismatched_node idx='%d' type='neither live nor dead'", i);
1243         }
1244       }
1245     }
1246     if (_log != nullptr) {
1247       _log->tail("mismatched_nodes");
1248     }
1249   }
1250 }
1251 void Compile::record_modified_node(Node* n) {
1252   if (_modified_nodes != nullptr && !_inlining_incrementally && !n->is_Con()) {
1253     _modified_nodes->push(n);
1254   }
1255 }
1256 
1257 void Compile::remove_modified_node(Node* n) {
1258   if (_modified_nodes != nullptr) {
1259     _modified_nodes->remove(n);
1260   }
1261 }
1262 #endif
1263 
1264 #ifndef PRODUCT
1265 void Compile::verify_top(Node* tn) const {
1266   if (tn != nullptr) {
1267     assert(tn->is_Con(), "top node must be a constant");
1268     assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
1269     assert(tn->in(0) != nullptr, "must have live top node");
1270   }
1271 }
1272 #endif
1273 
1274 
1275 ///-------------------Managing Per-Node Debug & Profile Info-------------------
1276 
1277 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
1278   guarantee(arr != nullptr, "");
1279   int num_blocks = arr->length();
1280   if (grow_by < num_blocks)  grow_by = num_blocks;
1281   int num_notes = grow_by * _node_notes_block_size;
1282   Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
1283   Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
1284   while (num_notes > 0) {
1285     arr->append(notes);
1286     notes     += _node_notes_block_size;
1287     num_notes -= _node_notes_block_size;
1288   }
1289   assert(num_notes == 0, "exact multiple, please");
1290 }
1291 
1292 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
1293   if (source == nullptr || dest == nullptr)  return false;
1294 
1295   if (dest->is_Con())
1296     return false;               // Do not push debug info onto constants.
1297 
1298 #ifdef ASSERT
1299   // Leave a bread crumb trail pointing to the original node:
1300   if (dest != nullptr && dest != source && dest->debug_orig() == nullptr) {
1301     dest->set_debug_orig(source);
1302   }
1303 #endif
1304 
1305   if (node_note_array() == nullptr)
1306     return false;               // Not collecting any notes now.
1307 
1308   // This is a copy onto a pre-existing node, which may already have notes.
1309   // If both nodes have notes, do not overwrite any pre-existing notes.
1310   Node_Notes* source_notes = node_notes_at(source->_idx);
1311   if (source_notes == nullptr || source_notes->is_clear())  return false;
1312   Node_Notes* dest_notes   = node_notes_at(dest->_idx);
1313   if (dest_notes == nullptr || dest_notes->is_clear()) {
1314     return set_node_notes_at(dest->_idx, source_notes);
1315   }
1316 
1317   Node_Notes merged_notes = (*source_notes);
1318   // The order of operations here ensures that dest notes will win...
1319   merged_notes.update_from(dest_notes);
1320   return set_node_notes_at(dest->_idx, &merged_notes);
1321 }
1322 
1323 
1324 //--------------------------allow_range_check_smearing-------------------------
1325 // Gating condition for coalescing similar range checks.
1326 // Sometimes we try 'speculatively' replacing a series of a range checks by a
1327 // single covering check that is at least as strong as any of them.
1328 // If the optimization succeeds, the simplified (strengthened) range check
1329 // will always succeed.  If it fails, we will deopt, and then give up
1330 // on the optimization.
1331 bool Compile::allow_range_check_smearing() const {
1332   // If this method has already thrown a range-check,
1333   // assume it was because we already tried range smearing
1334   // and it failed.
1335   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
1336   return !already_trapped;
1337 }
1338 
1339 
1340 //------------------------------flatten_alias_type-----------------------------
1341 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
1342   assert(do_aliasing(), "Aliasing should be enabled");
1343   int offset = tj->offset();
1344   TypePtr::PTR ptr = tj->ptr();
1345 
1346   // Known instance (scalarizable allocation) alias only with itself.
1347   bool is_known_inst = tj->isa_oopptr() != nullptr &&
1348                        tj->is_oopptr()->is_known_instance();
1349 
1350   // Process weird unsafe references.
1351   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
1352     assert(InlineUnsafeOps || StressReflectiveCode, "indeterminate pointers come only from unsafe ops");
1353     assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
1354     tj = TypeOopPtr::BOTTOM;
1355     ptr = tj->ptr();
1356     offset = tj->offset();
1357   }
1358 
1359   // Array pointers need some flattening
1360   const TypeAryPtr* ta = tj->isa_aryptr();
1361   if (ta && ta->is_stable()) {
1362     // Erase stability property for alias analysis.
1363     tj = ta = ta->cast_to_stable(false);
1364   }
1365   if( ta && is_known_inst ) {
1366     if ( offset != Type::OffsetBot &&
1367          offset > arrayOopDesc::length_offset_in_bytes() ) {
1368       offset = Type::OffsetBot; // Flatten constant access into array body only
1369       tj = ta = ta->
1370               remove_speculative()->
1371               cast_to_ptr_type(ptr)->
1372               with_offset(offset);
1373     }
1374   } else if (ta != nullptr) {
1375     // Common slices
1376     if (offset == arrayOopDesc::length_offset_in_bytes()) {
1377       return TypeAryPtr::RANGE;
1378     } else if (offset == oopDesc::klass_offset_in_bytes()) {
1379       return TypeInstPtr::KLASS;
1380     } else if (offset == oopDesc::mark_offset_in_bytes()) {
1381       return TypeInstPtr::MARK;
1382     }
1383 
1384     // Remove size and stability
1385     const TypeAry* normalized_ary = TypeAry::make(ta->elem(), TypeInt::POS, false);
1386     // Remove ptr, const_oop, and offset
1387     if (ta->elem() == Type::BOTTOM) {
1388       // Bottom array (meet of int[] and byte[] for example), accesses to it will be done with
1389       // Unsafe. This should alias with all arrays. For now just leave it as it is (this is
1390       // incorrect, see JDK-8331133).
1391       tj = ta = TypeAryPtr::make(TypePtr::BotPTR, nullptr, normalized_ary, nullptr, false, Type::OffsetBot);
1392     } else if (ta->elem()->make_oopptr() != nullptr) {
1393       // Object arrays, all of them share the same slice
1394       const TypeAry* tary = TypeAry::make(TypeInstPtr::BOTTOM, TypeInt::POS, false);
1395       tj = ta = TypeAryPtr::make(TypePtr::BotPTR, nullptr, tary, nullptr, false, Type::OffsetBot);
1396     } else {
1397       // Primitive arrays
1398       tj = ta = TypeAryPtr::make(TypePtr::BotPTR, nullptr, normalized_ary, ta->exact_klass(), true, Type::OffsetBot);
1399     }
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       tj = ta = TypeAryPtr::BYTES;
1405     }
1406   }
1407 
1408   // Oop pointers need some flattening
1409   const TypeInstPtr *to = tj->isa_instptr();
1410   if (to && to != TypeOopPtr::BOTTOM) {
1411     ciInstanceKlass* ik = to->instance_klass();
1412     if( ptr == TypePtr::Constant ) {
1413       if (ik != ciEnv::current()->Class_klass() ||
1414           offset < ik->layout_helper_size_in_bytes()) {
1415         // No constant oop pointers (such as Strings); they alias with
1416         // unknown strings.
1417         assert(!is_known_inst, "not scalarizable allocation");
1418         tj = to = to->
1419                 cast_to_instance_id(TypeOopPtr::InstanceBot)->
1420                 remove_speculative()->
1421                 cast_to_ptr_type(TypePtr::BotPTR)->
1422                 cast_to_exactness(false);
1423       }
1424     } else if( is_known_inst ) {
1425       tj = to; // Keep NotNull and klass_is_exact for instance type
1426     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
1427       // During the 2nd round of IterGVN, NotNull castings are removed.
1428       // Make sure the Bottom and NotNull variants alias the same.
1429       // Also, make sure exact and non-exact variants alias the same.
1430       tj = to = to->
1431               remove_speculative()->
1432               cast_to_instance_id(TypeOopPtr::InstanceBot)->
1433               cast_to_ptr_type(TypePtr::BotPTR)->
1434               cast_to_exactness(false);
1435     }
1436     if (to->speculative() != nullptr) {
1437       tj = to = to->remove_speculative();
1438     }
1439     // Canonicalize the holder of this field
1440     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
1441       // First handle header references such as a LoadKlassNode, even if the
1442       // object's klass is unloaded at compile time (4965979).
1443       if (!is_known_inst) { // Do it only for non-instance types
1444         tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, nullptr, offset);
1445       }
1446     } else if (offset < 0 || offset >= ik->layout_helper_size_in_bytes()) {
1447       // Static fields are in the space above the normal instance
1448       // fields in the java.lang.Class instance.
1449       if (ik != ciEnv::current()->Class_klass()) {
1450         to = nullptr;
1451         tj = TypeOopPtr::BOTTOM;
1452         offset = tj->offset();
1453       }
1454     } else {
1455       ciInstanceKlass *canonical_holder = ik->get_canonical_holder(offset);
1456       assert(offset < canonical_holder->layout_helper_size_in_bytes(), "");
1457       assert(tj->offset() == offset, "no change to offset expected");
1458       bool xk = to->klass_is_exact();
1459       int instance_id = to->instance_id();
1460 
1461       // If the input type's class is the holder: if exact, the type only includes interfaces implemented by the holder
1462       // but if not exact, it may include extra interfaces: build new type from the holder class to make sure only
1463       // its interfaces are included.
1464       if (xk && ik->equals(canonical_holder)) {
1465         assert(tj == TypeInstPtr::make(to->ptr(), canonical_holder, is_known_inst, nullptr, offset, instance_id), "exact type should be canonical type");
1466       } else {
1467         assert(xk || !is_known_inst, "Known instance should be exact type");
1468         tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, is_known_inst, nullptr, offset, instance_id);
1469       }
1470     }
1471   }
1472 
1473   // Klass pointers to object array klasses need some flattening
1474   const TypeKlassPtr *tk = tj->isa_klassptr();
1475   if( tk ) {
1476     // If we are referencing a field within a Klass, we need
1477     // to assume the worst case of an Object.  Both exact and
1478     // inexact types must flatten to the same alias class so
1479     // use NotNull as the PTR.
1480     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
1481       tj = tk = TypeInstKlassPtr::make(TypePtr::NotNull,
1482                                        env()->Object_klass(),
1483                                        offset);
1484     }
1485 
1486     if (tk->isa_aryklassptr() && tk->is_aryklassptr()->elem()->isa_klassptr()) {
1487       ciKlass* k = ciObjArrayKlass::make(env()->Object_klass());
1488       if (!k || !k->is_loaded()) {                  // Only fails for some -Xcomp runs
1489         tj = tk = TypeInstKlassPtr::make(TypePtr::NotNull, env()->Object_klass(), offset);
1490       } else {
1491         tj = tk = TypeAryKlassPtr::make(TypePtr::NotNull, tk->is_aryklassptr()->elem(), k, offset);
1492       }
1493     }
1494 
1495     // Check for precise loads from the primary supertype array and force them
1496     // to the supertype cache alias index.  Check for generic array loads from
1497     // the primary supertype array and also force them to the supertype cache
1498     // alias index.  Since the same load can reach both, we need to merge
1499     // these 2 disparate memories into the same alias class.  Since the
1500     // primary supertype array is read-only, there's no chance of confusion
1501     // where we bypass an array load and an array store.
1502     int primary_supers_offset = in_bytes(Klass::primary_supers_offset());
1503     if (offset == Type::OffsetBot ||
1504         (offset >= primary_supers_offset &&
1505          offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
1506         offset == (int)in_bytes(Klass::secondary_super_cache_offset())) {
1507       offset = in_bytes(Klass::secondary_super_cache_offset());
1508       tj = tk = tk->with_offset(offset);
1509     }
1510   }
1511 
1512   // Flatten all Raw pointers together.
1513   if (tj->base() == Type::RawPtr)
1514     tj = TypeRawPtr::BOTTOM;
1515 
1516   if (tj->base() == Type::AnyPtr)
1517     tj = TypePtr::BOTTOM;      // An error, which the caller must check for.
1518 
1519   offset = tj->offset();
1520   assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
1521 
1522   assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
1523           (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
1524           (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
1525           (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
1526           (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1527           (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1528           (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr),
1529           "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
1530   assert( tj->ptr() != TypePtr::TopPTR &&
1531           tj->ptr() != TypePtr::AnyNull &&
1532           tj->ptr() != TypePtr::Null, "No imprecise addresses" );
1533 //    assert( tj->ptr() != TypePtr::Constant ||
1534 //            tj->base() == Type::RawPtr ||
1535 //            tj->base() == Type::KlassPtr, "No constant oop addresses" );
1536 
1537   return tj;
1538 }
1539 
1540 void Compile::AliasType::Init(int i, const TypePtr* at) {
1541   assert(AliasIdxTop <= i && i < Compile::current()->_max_alias_types, "Invalid alias index");
1542   _index = i;
1543   _adr_type = at;
1544   _field = nullptr;
1545   _element = nullptr;
1546   _is_rewritable = true; // default
1547   const TypeOopPtr *atoop = (at != nullptr) ? at->isa_oopptr() : nullptr;
1548   if (atoop != nullptr && atoop->is_known_instance()) {
1549     const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
1550     _general_index = Compile::current()->get_alias_index(gt);
1551   } else {
1552     _general_index = 0;
1553   }
1554 }
1555 
1556 BasicType Compile::AliasType::basic_type() const {
1557   if (element() != nullptr) {
1558     const Type* element = adr_type()->is_aryptr()->elem();
1559     return element->isa_narrowoop() ? T_OBJECT : element->array_element_basic_type();
1560   } if (field() != nullptr) {
1561     return field()->layout_type();
1562   } else {
1563     return T_ILLEGAL; // unknown
1564   }
1565 }
1566 
1567 //---------------------------------print_on------------------------------------
1568 #ifndef PRODUCT
1569 void Compile::AliasType::print_on(outputStream* st) {
1570   if (index() < 10)
1571         st->print("@ <%d> ", index());
1572   else  st->print("@ <%d>",  index());
1573   st->print(is_rewritable() ? "   " : " RO");
1574   int offset = adr_type()->offset();
1575   if (offset == Type::OffsetBot)
1576         st->print(" +any");
1577   else  st->print(" +%-3d", offset);
1578   st->print(" in ");
1579   adr_type()->dump_on(st);
1580   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
1581   if (field() != nullptr && tjp) {
1582     if (tjp->is_instptr()->instance_klass()  != field()->holder() ||
1583         tjp->offset() != field()->offset_in_bytes()) {
1584       st->print(" != ");
1585       field()->print();
1586       st->print(" ***");
1587     }
1588   }
1589 }
1590 
1591 void print_alias_types() {
1592   Compile* C = Compile::current();
1593   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
1594   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
1595     C->alias_type(idx)->print_on(tty);
1596     tty->cr();
1597   }
1598 }
1599 #endif
1600 
1601 
1602 //----------------------------probe_alias_cache--------------------------------
1603 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
1604   intptr_t key = (intptr_t) adr_type;
1605   key ^= key >> logAliasCacheSize;
1606   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
1607 }
1608 
1609 
1610 //-----------------------------grow_alias_types--------------------------------
1611 void Compile::grow_alias_types() {
1612   const int old_ats  = _max_alias_types; // how many before?
1613   const int new_ats  = old_ats;          // how many more?
1614   const int grow_ats = old_ats+new_ats;  // how many now?
1615   _max_alias_types = grow_ats;
1616   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
1617   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
1618   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
1619   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
1620 }
1621 
1622 
1623 //--------------------------------find_alias_type------------------------------
1624 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field) {
1625   if (!do_aliasing()) {
1626     return alias_type(AliasIdxBot);
1627   }
1628 
1629   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1630   if (ace->_adr_type == adr_type) {
1631     return alias_type(ace->_index);
1632   }
1633 
1634   // Handle special cases.
1635   if (adr_type == nullptr)          return alias_type(AliasIdxTop);
1636   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
1637 
1638   // Do it the slow way.
1639   const TypePtr* flat = flatten_alias_type(adr_type);
1640 
1641 #ifdef ASSERT
1642   {
1643     ResourceMark rm;
1644     assert(flat == flatten_alias_type(flat), "not idempotent: adr_type = %s; flat = %s => %s",
1645            Type::str(adr_type), Type::str(flat), Type::str(flatten_alias_type(flat)));
1646     assert(flat != TypePtr::BOTTOM, "cannot alias-analyze an untyped ptr: adr_type = %s",
1647            Type::str(adr_type));
1648     if (flat->isa_oopptr() && !flat->isa_klassptr()) {
1649       const TypeOopPtr* foop = flat->is_oopptr();
1650       // Scalarizable allocations have exact klass always.
1651       bool exact = !foop->klass_is_exact() || foop->is_known_instance();
1652       const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
1653       assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type: foop = %s; xoop = %s",
1654              Type::str(foop), Type::str(xoop));
1655     }
1656   }
1657 #endif
1658 
1659   int idx = AliasIdxTop;
1660   for (int i = 0; i < num_alias_types(); i++) {
1661     if (alias_type(i)->adr_type() == flat) {
1662       idx = i;
1663       break;
1664     }
1665   }
1666 
1667   if (idx == AliasIdxTop) {
1668     if (no_create)  return nullptr;
1669     // Grow the array if necessary.
1670     if (_num_alias_types == _max_alias_types)  grow_alias_types();
1671     // Add a new alias type.
1672     idx = _num_alias_types++;
1673     _alias_types[idx]->Init(idx, flat);
1674     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
1675     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
1676     if (flat->isa_instptr()) {
1677       if (flat->offset() == java_lang_Class::klass_offset()
1678           && flat->is_instptr()->instance_klass() == env()->Class_klass())
1679         alias_type(idx)->set_rewritable(false);
1680     }
1681     if (flat->isa_aryptr()) {
1682 #ifdef ASSERT
1683       const int header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1684       // (T_BYTE has the weakest alignment and size restrictions...)
1685       assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
1686 #endif
1687       if (flat->offset() == TypePtr::OffsetBot) {
1688         alias_type(idx)->set_element(flat->is_aryptr()->elem());
1689       }
1690     }
1691     if (flat->isa_klassptr()) {
1692       if (UseCompactObjectHeaders) {
1693         if (flat->offset() == in_bytes(Klass::prototype_header_offset()))
1694           alias_type(idx)->set_rewritable(false);
1695       }
1696       if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
1697         alias_type(idx)->set_rewritable(false);
1698       if (flat->offset() == in_bytes(Klass::misc_flags_offset()))
1699         alias_type(idx)->set_rewritable(false);
1700       if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
1701         alias_type(idx)->set_rewritable(false);
1702       if (flat->offset() == in_bytes(Klass::secondary_super_cache_offset()))
1703         alias_type(idx)->set_rewritable(false);
1704     }
1705 
1706     if (flat->isa_instklassptr()) {
1707       if (flat->offset() == in_bytes(InstanceKlass::access_flags_offset())) {
1708         alias_type(idx)->set_rewritable(false);
1709       }
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(igvn);
1824   }
1825   _parse_predicates.clear();
1826 }
1827 
1828 void Compile::record_for_post_loop_opts_igvn(Node* n) {
1829   if (!n->for_post_loop_opts_igvn()) {
1830     assert(!_for_post_loop_igvn.contains(n), "duplicate");
1831     n->add_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
1832     _for_post_loop_igvn.append(n);
1833   }
1834 }
1835 
1836 void Compile::remove_from_post_loop_opts_igvn(Node* n) {
1837   n->remove_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
1838   _for_post_loop_igvn.remove(n);
1839 }
1840 
1841 void Compile::process_for_post_loop_opts_igvn(PhaseIterGVN& igvn) {
1842   // Verify that all previous optimizations produced a valid graph
1843   // at least to this point, even if no loop optimizations were done.
1844   PhaseIdealLoop::verify(igvn);
1845 
1846   if (_print_phase_loop_opts) {
1847     print_method(PHASE_AFTER_LOOP_OPTS, 2);
1848   }
1849   C->set_post_loop_opts_phase(); // no more loop opts allowed
1850 
1851   assert(!C->major_progress(), "not cleared");
1852 
1853   if (_for_post_loop_igvn.length() > 0) {
1854     while (_for_post_loop_igvn.length() > 0) {
1855       Node* n = _for_post_loop_igvn.pop();
1856       n->remove_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
1857       igvn._worklist.push(n);
1858     }
1859     igvn.optimize();
1860     if (failing()) return;
1861     assert(_for_post_loop_igvn.length() == 0, "no more delayed nodes allowed");
1862     assert(C->parse_predicate_count() == 0, "all parse predicates should have been removed now");
1863 
1864     // Sometimes IGVN sets major progress (e.g., when processing loop nodes).
1865     if (C->major_progress()) {
1866       C->clear_major_progress(); // ensure that major progress is now clear
1867     }
1868   }
1869 }
1870 
1871 void Compile::record_for_merge_stores_igvn(Node* n) {
1872   if (!n->for_merge_stores_igvn()) {
1873     assert(!_for_merge_stores_igvn.contains(n), "duplicate");
1874     n->add_flag(Node::NodeFlags::Flag_for_merge_stores_igvn);
1875     _for_merge_stores_igvn.append(n);
1876   }
1877 }
1878 
1879 void Compile::remove_from_merge_stores_igvn(Node* n) {
1880   n->remove_flag(Node::NodeFlags::Flag_for_merge_stores_igvn);
1881   _for_merge_stores_igvn.remove(n);
1882 }
1883 
1884 // We need to wait with merging stores until RangeCheck smearing has removed the RangeChecks during
1885 // the post loops IGVN phase. If we do it earlier, then there may still be some RangeChecks between
1886 // the stores, and we merge the wrong sequence of stores.
1887 // Example:
1888 //   StoreI RangeCheck StoreI StoreI RangeCheck StoreI
1889 // Apply MergeStores:
1890 //   StoreI RangeCheck [   StoreL  ] RangeCheck StoreI
1891 // Remove more RangeChecks:
1892 //   StoreI            [   StoreL  ]            StoreI
1893 // But now it would have been better to do this instead:
1894 //   [         StoreL       ] [       StoreL         ]
1895 //
1896 // Note: we allow stores to merge in this dedicated IGVN round, and any later IGVN round,
1897 //       since we never unset _merge_stores_phase.
1898 void Compile::process_for_merge_stores_igvn(PhaseIterGVN& igvn) {
1899   C->set_merge_stores_phase();
1900 
1901   if (_for_merge_stores_igvn.length() > 0) {
1902     while (_for_merge_stores_igvn.length() > 0) {
1903       Node* n = _for_merge_stores_igvn.pop();
1904       n->remove_flag(Node::NodeFlags::Flag_for_merge_stores_igvn);
1905       igvn._worklist.push(n);
1906     }
1907     igvn.optimize();
1908     if (failing()) return;
1909     assert(_for_merge_stores_igvn.length() == 0, "no more delayed nodes allowed");
1910     print_method(PHASE_AFTER_MERGE_STORES, 3);
1911   }
1912 }
1913 
1914 void Compile::record_unstable_if_trap(UnstableIfTrap* trap) {
1915   if (OptimizeUnstableIf) {
1916     _unstable_if_traps.append(trap);
1917   }
1918 }
1919 
1920 void Compile::remove_useless_unstable_if_traps(Unique_Node_List& useful) {
1921   for (int i = _unstable_if_traps.length() - 1; i >= 0; i--) {
1922     UnstableIfTrap* trap = _unstable_if_traps.at(i);
1923     Node* n = trap->uncommon_trap();
1924     if (!useful.member(n)) {
1925       _unstable_if_traps.delete_at(i); // replaces i-th with last element which is known to be useful (already processed)
1926     }
1927   }
1928 }
1929 
1930 // Remove the unstable if trap associated with 'unc' from candidates. It is either dead
1931 // or fold-compares case. Return true if succeed or not found.
1932 //
1933 // In rare cases, the found trap has been processed. It is too late to delete it. Return
1934 // false and ask fold-compares to yield.
1935 //
1936 // 'fold-compares' may use the uncommon_trap of the dominating IfNode to cover the fused
1937 // IfNode. This breaks the unstable_if trap invariant: control takes the unstable path
1938 // when deoptimization does happen.
1939 bool Compile::remove_unstable_if_trap(CallStaticJavaNode* unc, bool yield) {
1940   for (int i = 0; i < _unstable_if_traps.length(); ++i) {
1941     UnstableIfTrap* trap = _unstable_if_traps.at(i);
1942     if (trap->uncommon_trap() == unc) {
1943       if (yield && trap->modified()) {
1944         return false;
1945       }
1946       _unstable_if_traps.delete_at(i);
1947       break;
1948     }
1949   }
1950   return true;
1951 }
1952 
1953 // Re-calculate unstable_if traps with the liveness of next_bci, which points to the unlikely path.
1954 // It needs to be done after igvn because fold-compares may fuse uncommon_traps and before renumbering.
1955 void Compile::process_for_unstable_if_traps(PhaseIterGVN& igvn) {
1956   for (int i = _unstable_if_traps.length() - 1; i >= 0; --i) {
1957     UnstableIfTrap* trap = _unstable_if_traps.at(i);
1958     CallStaticJavaNode* unc = trap->uncommon_trap();
1959     int next_bci = trap->next_bci();
1960     bool modified = trap->modified();
1961 
1962     if (next_bci != -1 && !modified) {
1963       assert(!_dead_node_list.test(unc->_idx), "changing a dead node!");
1964       JVMState* jvms = unc->jvms();
1965       ciMethod* method = jvms->method();
1966       ciBytecodeStream iter(method);
1967 
1968       iter.force_bci(jvms->bci());
1969       assert(next_bci == iter.next_bci() || next_bci == iter.get_dest(), "wrong next_bci at unstable_if");
1970       Bytecodes::Code c = iter.cur_bc();
1971       Node* lhs = nullptr;
1972       Node* rhs = nullptr;
1973       if (c == Bytecodes::_if_acmpeq || c == Bytecodes::_if_acmpne) {
1974         lhs = unc->peek_operand(0);
1975         rhs = unc->peek_operand(1);
1976       } else if (c == Bytecodes::_ifnull || c == Bytecodes::_ifnonnull) {
1977         lhs = unc->peek_operand(0);
1978       }
1979 
1980       ResourceMark rm;
1981       const MethodLivenessResult& live_locals = method->liveness_at_bci(next_bci);
1982       assert(live_locals.is_valid(), "broken liveness info");
1983       int len = (int)live_locals.size();
1984 
1985       for (int i = 0; i < len; i++) {
1986         Node* local = unc->local(jvms, i);
1987         // kill local using the liveness of next_bci.
1988         // give up when the local looks like an operand to secure reexecution.
1989         if (!live_locals.at(i) && !local->is_top() && local != lhs && local!= rhs) {
1990           uint idx = jvms->locoff() + i;
1991 #ifdef ASSERT
1992           if (PrintOpto && Verbose) {
1993             tty->print("[unstable_if] kill local#%d: ", idx);
1994             local->dump();
1995             tty->cr();
1996           }
1997 #endif
1998           igvn.replace_input_of(unc, idx, top());
1999           modified = true;
2000         }
2001       }
2002     }
2003 
2004     // keep the mondified trap for late query
2005     if (modified) {
2006       trap->set_modified();
2007     } else {
2008       _unstable_if_traps.delete_at(i);
2009     }
2010   }
2011   igvn.optimize();
2012 }
2013 
2014 // StringOpts and late inlining of string methods
2015 void Compile::inline_string_calls(bool parse_time) {
2016   {
2017     // remove useless nodes to make the usage analysis simpler
2018     ResourceMark rm;
2019     PhaseRemoveUseless pru(initial_gvn(), *igvn_worklist());
2020   }
2021 
2022   {
2023     ResourceMark rm;
2024     print_method(PHASE_BEFORE_STRINGOPTS, 3);
2025     PhaseStringOpts pso(initial_gvn());
2026     print_method(PHASE_AFTER_STRINGOPTS, 3);
2027   }
2028 
2029   // now inline anything that we skipped the first time around
2030   if (!parse_time) {
2031     _late_inlines_pos = _late_inlines.length();
2032   }
2033 
2034   while (_string_late_inlines.length() > 0) {
2035     CallGenerator* cg = _string_late_inlines.pop();
2036     cg->do_late_inline();
2037     if (failing())  return;
2038   }
2039   _string_late_inlines.trunc_to(0);
2040 }
2041 
2042 // Late inlining of boxing methods
2043 void Compile::inline_boxing_calls(PhaseIterGVN& igvn) {
2044   if (_boxing_late_inlines.length() > 0) {
2045     assert(has_boxed_value(), "inconsistent");
2046 
2047     set_inlining_incrementally(true);
2048 
2049     igvn_worklist()->ensure_empty(); // should be done with igvn
2050 
2051     _late_inlines_pos = _late_inlines.length();
2052 
2053     while (_boxing_late_inlines.length() > 0) {
2054       CallGenerator* cg = _boxing_late_inlines.pop();
2055       cg->do_late_inline();
2056       if (failing())  return;
2057     }
2058     _boxing_late_inlines.trunc_to(0);
2059 
2060     inline_incrementally_cleanup(igvn);
2061 
2062     set_inlining_incrementally(false);
2063   }
2064 }
2065 
2066 bool Compile::inline_incrementally_one() {
2067   assert(IncrementalInline, "incremental inlining should be on");
2068   assert(_late_inlines.length() > 0, "should have been checked by caller");
2069 
2070   TracePhase tp(_t_incrInline_inline);
2071 
2072   set_inlining_progress(false);
2073   set_do_cleanup(false);
2074 
2075   for (int i = 0; i < _late_inlines.length(); i++) {
2076     _late_inlines_pos = i+1;
2077     CallGenerator* cg = _late_inlines.at(i);
2078     bool is_scheduled_for_igvn_before = C->igvn_worklist()->member(cg->call_node());
2079     bool does_dispatch = cg->is_virtual_late_inline() || cg->is_mh_late_inline();
2080     if (inlining_incrementally() || does_dispatch) { // a call can be either inlined or strength-reduced to a direct call
2081       if (should_stress_inlining()) {
2082         // randomly add repeated inline attempt if stress-inlining
2083         cg->call_node()->set_generator(cg);
2084         C->igvn_worklist()->push(cg->call_node());
2085         continue;
2086       }
2087       cg->do_late_inline();
2088       assert(_late_inlines.at(i) == cg, "no insertions before current position allowed");
2089       if (failing()) {
2090         return false;
2091       } else if (inlining_progress()) {
2092         _late_inlines_pos = i+1; // restore the position in case new elements were inserted
2093         print_method(PHASE_INCREMENTAL_INLINE_STEP, 3, cg->call_node());
2094         break; // process one call site at a time
2095       } else {
2096         bool is_scheduled_for_igvn_after = C->igvn_worklist()->member(cg->call_node());
2097         if (!is_scheduled_for_igvn_before && is_scheduled_for_igvn_after) {
2098           // Avoid potential infinite loop if node already in the IGVN list
2099           assert(false, "scheduled for IGVN during inlining attempt");
2100         } else {
2101           // Ensure call node has not disappeared from IGVN worklist during a failed inlining attempt
2102           assert(!is_scheduled_for_igvn_before || is_scheduled_for_igvn_after, "call node removed from IGVN list during inlining pass");
2103           cg->call_node()->set_generator(cg);
2104         }
2105       }
2106     } else {
2107       // Ignore late inline direct calls when inlining is not allowed.
2108       // They are left in the late inline list when node budget is exhausted until the list is fully drained.
2109     }
2110   }
2111   // Remove processed elements.
2112   _late_inlines.remove_till(_late_inlines_pos);
2113   _late_inlines_pos = 0;
2114 
2115   assert(inlining_progress() || _late_inlines.length() == 0, "no progress");
2116 
2117   bool needs_cleanup = do_cleanup() || over_inlining_cutoff();
2118 
2119   set_inlining_progress(false);
2120   set_do_cleanup(false);
2121 
2122   bool force_cleanup = directive()->IncrementalInlineForceCleanupOption;
2123   return (_late_inlines.length() > 0) && !needs_cleanup && !force_cleanup;
2124 }
2125 
2126 void Compile::inline_incrementally_cleanup(PhaseIterGVN& igvn) {
2127   {
2128     TracePhase tp(_t_incrInline_pru);
2129     ResourceMark rm;
2130     PhaseRemoveUseless pru(initial_gvn(), *igvn_worklist());
2131   }
2132   {
2133     TracePhase tp(_t_incrInline_igvn);
2134     igvn.reset();
2135     igvn.optimize();
2136     if (failing()) return;
2137   }
2138   print_method(PHASE_INCREMENTAL_INLINE_CLEANUP, 3);
2139 }
2140 
2141 template<typename E>
2142 static void shuffle_array(Compile& C, GrowableArray<E>& array) {
2143   if (array.length() < 2) {
2144     return;
2145   }
2146   for (uint i = array.length() - 1; i >= 1; i--) {
2147     uint j = C.random() % (i + 1);
2148     swap(array.at(i), array.at(j));
2149   }
2150 }
2151 
2152 void Compile::shuffle_late_inlines() {
2153   shuffle_array(*C, _late_inlines);
2154 }
2155 
2156 // Perform incremental inlining until bound on number of live nodes is reached
2157 void Compile::inline_incrementally(PhaseIterGVN& igvn) {
2158   TracePhase tp(_t_incrInline);
2159 
2160   set_inlining_incrementally(true);
2161   uint low_live_nodes = 0;
2162 
2163   if (StressIncrementalInlining) {
2164     shuffle_late_inlines();
2165   }
2166 
2167   while (_late_inlines.length() > 0) {
2168     if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2169       if (low_live_nodes < (uint)LiveNodeCountInliningCutoff * 8 / 10) {
2170         TracePhase tp(_t_incrInline_ideal);
2171         // PhaseIdealLoop is expensive so we only try it once we are
2172         // out of live nodes and we only try it again if the previous
2173         // helped got the number of nodes down significantly
2174         PhaseIdealLoop::optimize(igvn, LoopOptsNone);
2175         if (failing())  return;
2176         low_live_nodes = live_nodes();
2177         _major_progress = true;
2178       }
2179 
2180       if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2181         bool do_print_inlining = print_inlining() || print_intrinsics();
2182         if (do_print_inlining || log() != nullptr) {
2183           // Print inlining message for candidates that we couldn't inline for lack of space.
2184           for (int i = 0; i < _late_inlines.length(); i++) {
2185             CallGenerator* cg = _late_inlines.at(i);
2186             const char* msg = "live nodes > LiveNodeCountInliningCutoff";
2187             if (do_print_inlining) {
2188               inline_printer()->record(cg->method(), cg->call_node()->jvms(), InliningResult::FAILURE, msg);
2189             }
2190             log_late_inline_failure(cg, msg);
2191           }
2192         }
2193         break; // finish
2194       }
2195     }
2196 
2197     igvn_worklist()->ensure_empty(); // should be done with igvn
2198 
2199     if (_late_inlines.length() == 0) {
2200       break; // no more progress
2201     }
2202 
2203     while (inline_incrementally_one()) {
2204       assert(!failing_internal() || failure_is_artificial(), "inconsistent");
2205     }
2206     if (failing())  return;
2207 
2208     inline_incrementally_cleanup(igvn);
2209 
2210     print_method(PHASE_INCREMENTAL_INLINE_STEP, 3);
2211 
2212     if (failing())  return;
2213   }
2214 
2215   igvn_worklist()->ensure_empty(); // should be done with igvn
2216 
2217   if (_string_late_inlines.length() > 0) {
2218     assert(has_stringbuilder(), "inconsistent");
2219 
2220     inline_string_calls(false);
2221 
2222     if (failing())  return;
2223 
2224     inline_incrementally_cleanup(igvn);
2225   }
2226 
2227   set_inlining_incrementally(false);
2228 }
2229 
2230 void Compile::process_late_inline_calls_no_inline(PhaseIterGVN& igvn) {
2231   // "inlining_incrementally() == false" is used to signal that no inlining is allowed
2232   // (see LateInlineVirtualCallGenerator::do_late_inline_check() for details).
2233   // Tracking and verification of modified nodes is disabled by setting "_modified_nodes == nullptr"
2234   // as if "inlining_incrementally() == true" were set.
2235   assert(inlining_incrementally() == false, "not allowed");
2236   assert(_modified_nodes == nullptr, "not allowed");
2237   assert(_late_inlines.length() > 0, "sanity");
2238 
2239   if (StressIncrementalInlining) {
2240     shuffle_late_inlines();
2241   }
2242 
2243   while (_late_inlines.length() > 0) {
2244     igvn_worklist()->ensure_empty(); // should be done with igvn
2245 
2246     while (inline_incrementally_one()) {
2247       assert(!failing_internal() || failure_is_artificial(), "inconsistent");
2248     }
2249     if (failing())  return;
2250 
2251     inline_incrementally_cleanup(igvn);
2252   }
2253 }
2254 
2255 bool Compile::optimize_loops(PhaseIterGVN& igvn, LoopOptsMode mode) {
2256   if (_loop_opts_cnt > 0) {
2257     while (major_progress() && (_loop_opts_cnt > 0)) {
2258       TracePhase tp(_t_idealLoop);
2259       PhaseIdealLoop::optimize(igvn, mode);
2260       _loop_opts_cnt--;
2261       if (failing())  return false;
2262       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
2263     }
2264   }
2265   return true;
2266 }
2267 
2268 // Remove edges from "root" to each SafePoint at a backward branch.
2269 // They were inserted during parsing (see add_safepoint()) to make
2270 // infinite loops without calls or exceptions visible to root, i.e.,
2271 // useful.
2272 void Compile::remove_root_to_sfpts_edges(PhaseIterGVN& igvn) {
2273   Node *r = root();
2274   if (r != nullptr) {
2275     for (uint i = r->req(); i < r->len(); ++i) {
2276       Node *n = r->in(i);
2277       if (n != nullptr && n->is_SafePoint()) {
2278         r->rm_prec(i);
2279         if (n->outcnt() == 0) {
2280           igvn.remove_dead_node(n);
2281         }
2282         --i;
2283       }
2284     }
2285     // Parsing may have added top inputs to the root node (Path
2286     // leading to the Halt node proven dead). Make sure we get a
2287     // chance to clean them up.
2288     igvn._worklist.push(r);
2289     igvn.optimize();
2290   }
2291 }
2292 
2293 //------------------------------Optimize---------------------------------------
2294 // Given a graph, optimize it.
2295 void Compile::Optimize() {
2296   TracePhase tp(_t_optimizer);
2297 
2298 #ifndef PRODUCT
2299   if (env()->break_at_compile()) {
2300     BREAKPOINT;
2301   }
2302 
2303 #endif
2304 
2305   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
2306 #ifdef ASSERT
2307   bs->verify_gc_barriers(this, BarrierSetC2::BeforeOptimize);
2308 #endif
2309 
2310   ResourceMark rm;
2311 
2312   NOT_PRODUCT( verify_graph_edges(); )
2313 
2314   print_method(PHASE_AFTER_PARSING, 1);
2315 
2316  {
2317   // Iterative Global Value Numbering, including ideal transforms
2318   PhaseIterGVN igvn;
2319 #ifdef ASSERT
2320   _modified_nodes = new (comp_arena()) Unique_Node_List(comp_arena());
2321 #endif
2322   {
2323     TracePhase tp(_t_iterGVN);
2324     igvn.optimize();
2325   }
2326 
2327   if (failing())  return;
2328 
2329   print_method(PHASE_ITER_GVN1, 2);
2330 
2331   process_for_unstable_if_traps(igvn);
2332 
2333   if (failing())  return;
2334 
2335   inline_incrementally(igvn);
2336 
2337   print_method(PHASE_INCREMENTAL_INLINE, 2);
2338 
2339   if (failing())  return;
2340 
2341   if (eliminate_boxing()) {
2342     // Inline valueOf() methods now.
2343     inline_boxing_calls(igvn);
2344 
2345     if (failing())  return;
2346 
2347     if (AlwaysIncrementalInline || StressIncrementalInlining) {
2348       inline_incrementally(igvn);
2349     }
2350 
2351     print_method(PHASE_INCREMENTAL_BOXING_INLINE, 2);
2352 
2353     if (failing())  return;
2354   }
2355 
2356   // Remove the speculative part of types and clean up the graph from
2357   // the extra CastPP nodes whose only purpose is to carry them. Do
2358   // that early so that optimizations are not disrupted by the extra
2359   // CastPP nodes.
2360   remove_speculative_types(igvn);
2361 
2362   if (failing())  return;
2363 
2364   // No more new expensive nodes will be added to the list from here
2365   // so keep only the actual candidates for optimizations.
2366   cleanup_expensive_nodes(igvn);
2367 
2368   if (failing())  return;
2369 
2370   assert(EnableVectorSupport || !has_vbox_nodes(), "sanity");
2371   if (EnableVectorSupport && has_vbox_nodes()) {
2372     TracePhase tp(_t_vector);
2373     PhaseVector pv(igvn);
2374     pv.optimize_vector_boxes();
2375     if (failing())  return;
2376     print_method(PHASE_ITER_GVN_AFTER_VECTOR, 2);
2377   }
2378   assert(!has_vbox_nodes(), "sanity");
2379 
2380   if (!failing() && RenumberLiveNodes && live_nodes() + NodeLimitFudgeFactor < unique()) {
2381     Compile::TracePhase tp(_t_renumberLive);
2382     igvn_worklist()->ensure_empty(); // should be done with igvn
2383     {
2384       ResourceMark rm;
2385       PhaseRenumberLive prl(initial_gvn(), *igvn_worklist());
2386     }
2387     igvn.reset();
2388     igvn.optimize();
2389     if (failing()) return;
2390   }
2391 
2392   // Now that all inlining is over and no PhaseRemoveUseless will run, cut edge from root to loop
2393   // safepoints
2394   remove_root_to_sfpts_edges(igvn);
2395 
2396   if (failing())  return;
2397 
2398   _print_phase_loop_opts = has_loops();
2399   if (_print_phase_loop_opts) {
2400     print_method(PHASE_BEFORE_LOOP_OPTS, 2);
2401   }
2402 
2403   // Perform escape analysis
2404   if (do_escape_analysis() && ConnectionGraph::has_candidates(this)) {
2405     if (has_loops()) {
2406       // Cleanup graph (remove dead nodes).
2407       TracePhase tp(_t_idealLoop);
2408       PhaseIdealLoop::optimize(igvn, LoopOptsMaxUnroll);
2409       if (failing())  return;
2410     }
2411     bool progress;
2412     print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
2413     do {
2414       ConnectionGraph::do_analysis(this, &igvn);
2415 
2416       if (failing())  return;
2417 
2418       int mcount = macro_count(); // Record number of allocations and locks before IGVN
2419 
2420       // Optimize out fields loads from scalar replaceable allocations.
2421       igvn.optimize();
2422       print_method(PHASE_ITER_GVN_AFTER_EA, 2);
2423 
2424       if (failing()) return;
2425 
2426       if (congraph() != nullptr && macro_count() > 0) {
2427         TracePhase tp(_t_macroEliminate);
2428         PhaseMacroExpand mexp(igvn);
2429         mexp.eliminate_macro_nodes();
2430         if (failing()) return;
2431         print_method(PHASE_AFTER_MACRO_ELIMINATION, 2);
2432 
2433         igvn.set_delay_transform(false);
2434         igvn.optimize();
2435         if (failing()) return;
2436 
2437         print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
2438       }
2439 
2440       ConnectionGraph::verify_ram_nodes(this, root());
2441       if (failing())  return;
2442 
2443       progress = do_iterative_escape_analysis() &&
2444                  (macro_count() < mcount) &&
2445                  ConnectionGraph::has_candidates(this);
2446       // Try again if candidates exist and made progress
2447       // by removing some allocations and/or locks.
2448     } while (progress);
2449   }
2450 
2451   // Loop transforms on the ideal graph.  Range Check Elimination,
2452   // peeling, unrolling, etc.
2453 
2454   // Set loop opts counter
2455   if((_loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
2456     {
2457       TracePhase tp(_t_idealLoop);
2458       PhaseIdealLoop::optimize(igvn, LoopOptsDefault);
2459       _loop_opts_cnt--;
2460       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP1, 2);
2461       if (failing())  return;
2462     }
2463     // Loop opts pass if partial peeling occurred in previous pass
2464     if(PartialPeelLoop && major_progress() && (_loop_opts_cnt > 0)) {
2465       TracePhase tp(_t_idealLoop);
2466       PhaseIdealLoop::optimize(igvn, LoopOptsSkipSplitIf);
2467       _loop_opts_cnt--;
2468       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP2, 2);
2469       if (failing())  return;
2470     }
2471     // Loop opts pass for loop-unrolling before CCP
2472     if(major_progress() && (_loop_opts_cnt > 0)) {
2473       TracePhase tp(_t_idealLoop);
2474       PhaseIdealLoop::optimize(igvn, LoopOptsSkipSplitIf);
2475       _loop_opts_cnt--;
2476       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP3, 2);
2477     }
2478     if (!failing()) {
2479       // Verify that last round of loop opts produced a valid graph
2480       PhaseIdealLoop::verify(igvn);
2481     }
2482   }
2483   if (failing())  return;
2484 
2485   // Conditional Constant Propagation;
2486   print_method(PHASE_BEFORE_CCP1, 2);
2487   PhaseCCP ccp( &igvn );
2488   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
2489   {
2490     TracePhase tp(_t_ccp);
2491     ccp.do_transform();
2492   }
2493   print_method(PHASE_CCP1, 2);
2494 
2495   assert( true, "Break here to ccp.dump_old2new_map()");
2496 
2497   // Iterative Global Value Numbering, including ideal transforms
2498   {
2499     TracePhase tp(_t_iterGVN2);
2500     igvn.reset_from_igvn(&ccp);
2501     igvn.optimize();
2502   }
2503   print_method(PHASE_ITER_GVN2, 2);
2504 
2505   if (failing())  return;
2506 
2507   // Loop transforms on the ideal graph.  Range Check Elimination,
2508   // peeling, unrolling, etc.
2509   if (!optimize_loops(igvn, LoopOptsDefault)) {
2510     return;
2511   }
2512 
2513   if (failing())  return;
2514 
2515   C->clear_major_progress(); // ensure that major progress is now clear
2516 
2517   process_for_post_loop_opts_igvn(igvn);
2518 
2519   process_for_merge_stores_igvn(igvn);
2520 
2521   if (failing())  return;
2522 
2523 #ifdef ASSERT
2524   bs->verify_gc_barriers(this, BarrierSetC2::BeforeMacroExpand);
2525 #endif
2526 
2527   {
2528     TracePhase tp(_t_macroExpand);
2529     print_method(PHASE_BEFORE_MACRO_EXPANSION, 3);
2530     PhaseMacroExpand  mex(igvn);
2531     // Do not allow new macro nodes once we start to eliminate and expand
2532     C->reset_allow_macro_nodes();
2533     // Last attempt to eliminate macro nodes before expand
2534     mex.eliminate_macro_nodes();
2535     if (failing()) {
2536       return;
2537     }
2538     mex.eliminate_opaque_looplimit_macro_nodes();
2539     if (failing()) {
2540       return;
2541     }
2542     print_method(PHASE_AFTER_MACRO_ELIMINATION, 2);
2543     if (mex.expand_macro_nodes()) {
2544       assert(failing(), "must bail out w/ explicit message");
2545       return;
2546     }
2547     print_method(PHASE_AFTER_MACRO_EXPANSION, 2);
2548   }
2549 
2550   {
2551     TracePhase tp(_t_barrierExpand);
2552     if (bs->expand_barriers(this, igvn)) {
2553       assert(failing(), "must bail out w/ explicit message");
2554       return;
2555     }
2556     print_method(PHASE_BARRIER_EXPANSION, 2);
2557   }
2558 
2559   if (C->max_vector_size() > 0) {
2560     C->optimize_logic_cones(igvn);
2561     igvn.optimize();
2562     if (failing()) return;
2563   }
2564 
2565   DEBUG_ONLY( _modified_nodes = nullptr; )
2566 
2567   assert(igvn._worklist.size() == 0, "not empty");
2568 
2569   assert(_late_inlines.length() == 0 || IncrementalInlineMH || IncrementalInlineVirtual, "not empty");
2570 
2571   if (_late_inlines.length() > 0) {
2572     // More opportunities to optimize virtual and MH calls.
2573     // Though it's maybe too late to perform inlining, strength-reducing them to direct calls is still an option.
2574     process_late_inline_calls_no_inline(igvn);
2575     if (failing())  return;
2576   }
2577  } // (End scope of igvn; run destructor if necessary for asserts.)
2578 
2579  check_no_dead_use();
2580 
2581  // We will never use the NodeHash table any more. Clear it so that final_graph_reshaping does not have
2582  // to remove hashes to unlock nodes for modifications.
2583  C->node_hash()->clear();
2584 
2585  // A method with only infinite loops has no edges entering loops from root
2586  {
2587    TracePhase tp(_t_graphReshaping);
2588    if (final_graph_reshaping()) {
2589      assert(failing(), "must bail out w/ explicit message");
2590      return;
2591    }
2592  }
2593 
2594  print_method(PHASE_OPTIMIZE_FINISHED, 2);
2595  DEBUG_ONLY(set_phase_optimize_finished();)
2596 }
2597 
2598 #ifdef ASSERT
2599 void Compile::check_no_dead_use() const {
2600   ResourceMark rm;
2601   Unique_Node_List wq;
2602   wq.push(root());
2603   for (uint i = 0; i < wq.size(); ++i) {
2604     Node* n = wq.at(i);
2605     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
2606       Node* u = n->fast_out(j);
2607       if (u->outcnt() == 0 && !u->is_Con()) {
2608         u->dump();
2609         fatal("no reachable node should have no use");
2610       }
2611       wq.push(u);
2612     }
2613   }
2614 }
2615 #endif
2616 
2617 void Compile::inline_vector_reboxing_calls() {
2618   if (C->_vector_reboxing_late_inlines.length() > 0) {
2619     _late_inlines_pos = C->_late_inlines.length();
2620     while (_vector_reboxing_late_inlines.length() > 0) {
2621       CallGenerator* cg = _vector_reboxing_late_inlines.pop();
2622       cg->do_late_inline();
2623       if (failing())  return;
2624       print_method(PHASE_INLINE_VECTOR_REBOX, 3, cg->call_node());
2625     }
2626     _vector_reboxing_late_inlines.trunc_to(0);
2627   }
2628 }
2629 
2630 bool Compile::has_vbox_nodes() {
2631   if (C->_vector_reboxing_late_inlines.length() > 0) {
2632     return true;
2633   }
2634   for (int macro_idx = C->macro_count() - 1; macro_idx >= 0; macro_idx--) {
2635     Node * n = C->macro_node(macro_idx);
2636     assert(n->is_macro(), "only macro nodes expected here");
2637     if (n->Opcode() == Op_VectorUnbox || n->Opcode() == Op_VectorBox || n->Opcode() == Op_VectorBoxAllocate) {
2638       return true;
2639     }
2640   }
2641   return false;
2642 }
2643 
2644 //---------------------------- Bitwise operation packing optimization ---------------------------
2645 
2646 static bool is_vector_unary_bitwise_op(Node* n) {
2647   return n->Opcode() == Op_XorV &&
2648          VectorNode::is_vector_bitwise_not_pattern(n);
2649 }
2650 
2651 static bool is_vector_binary_bitwise_op(Node* n) {
2652   switch (n->Opcode()) {
2653     case Op_AndV:
2654     case Op_OrV:
2655       return true;
2656 
2657     case Op_XorV:
2658       return !is_vector_unary_bitwise_op(n);
2659 
2660     default:
2661       return false;
2662   }
2663 }
2664 
2665 static bool is_vector_ternary_bitwise_op(Node* n) {
2666   return n->Opcode() == Op_MacroLogicV;
2667 }
2668 
2669 static bool is_vector_bitwise_op(Node* n) {
2670   return is_vector_unary_bitwise_op(n)  ||
2671          is_vector_binary_bitwise_op(n) ||
2672          is_vector_ternary_bitwise_op(n);
2673 }
2674 
2675 static bool is_vector_bitwise_cone_root(Node* n) {
2676   if (n->bottom_type()->isa_vectmask() || !is_vector_bitwise_op(n)) {
2677     return false;
2678   }
2679   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2680     if (is_vector_bitwise_op(n->fast_out(i))) {
2681       return false;
2682     }
2683   }
2684   return true;
2685 }
2686 
2687 static uint collect_unique_inputs(Node* n, Unique_Node_List& inputs) {
2688   uint cnt = 0;
2689   if (is_vector_bitwise_op(n)) {
2690     uint inp_cnt = n->is_predicated_vector() ? n->req()-1 : n->req();
2691     if (VectorNode::is_vector_bitwise_not_pattern(n)) {
2692       for (uint i = 1; i < inp_cnt; i++) {
2693         Node* in = n->in(i);
2694         bool skip = VectorNode::is_all_ones_vector(in);
2695         if (!skip && !inputs.member(in)) {
2696           inputs.push(in);
2697           cnt++;
2698         }
2699       }
2700       assert(cnt <= 1, "not unary");
2701     } else {
2702       uint last_req = inp_cnt;
2703       if (is_vector_ternary_bitwise_op(n)) {
2704         last_req = inp_cnt - 1; // skip last input
2705       }
2706       for (uint i = 1; i < last_req; i++) {
2707         Node* def = n->in(i);
2708         if (!inputs.member(def)) {
2709           inputs.push(def);
2710           cnt++;
2711         }
2712       }
2713     }
2714   } else { // not a bitwise operations
2715     if (!inputs.member(n)) {
2716       inputs.push(n);
2717       cnt++;
2718     }
2719   }
2720   return cnt;
2721 }
2722 
2723 void Compile::collect_logic_cone_roots(Unique_Node_List& list) {
2724   Unique_Node_List useful_nodes;
2725   C->identify_useful_nodes(useful_nodes);
2726 
2727   for (uint i = 0; i < useful_nodes.size(); i++) {
2728     Node* n = useful_nodes.at(i);
2729     if (is_vector_bitwise_cone_root(n)) {
2730       list.push(n);
2731     }
2732   }
2733 }
2734 
2735 Node* Compile::xform_to_MacroLogicV(PhaseIterGVN& igvn,
2736                                     const TypeVect* vt,
2737                                     Unique_Node_List& partition,
2738                                     Unique_Node_List& inputs) {
2739   assert(partition.size() == 2 || partition.size() == 3, "not supported");
2740   assert(inputs.size()    == 2 || inputs.size()    == 3, "not supported");
2741   assert(Matcher::match_rule_supported_vector(Op_MacroLogicV, vt->length(), vt->element_basic_type()), "not supported");
2742 
2743   Node* in1 = inputs.at(0);
2744   Node* in2 = inputs.at(1);
2745   Node* in3 = (inputs.size() == 3 ? inputs.at(2) : in2);
2746 
2747   uint func = compute_truth_table(partition, inputs);
2748 
2749   Node* pn = partition.at(partition.size() - 1);
2750   Node* mask = pn->is_predicated_vector() ? pn->in(pn->req()-1) : nullptr;
2751   return igvn.transform(MacroLogicVNode::make(igvn, in1, in2, in3, mask, func, vt));
2752 }
2753 
2754 static uint extract_bit(uint func, uint pos) {
2755   return (func & (1 << pos)) >> pos;
2756 }
2757 
2758 //
2759 //  A macro logic node represents a truth table. It has 4 inputs,
2760 //  First three inputs corresponds to 3 columns of a truth table
2761 //  and fourth input captures the logic function.
2762 //
2763 //  eg.  fn = (in1 AND in2) OR in3;
2764 //
2765 //      MacroNode(in1,in2,in3,fn)
2766 //
2767 //  -----------------
2768 //  in1 in2 in3  fn
2769 //  -----------------
2770 //  0    0   0    0
2771 //  0    0   1    1
2772 //  0    1   0    0
2773 //  0    1   1    1
2774 //  1    0   0    0
2775 //  1    0   1    1
2776 //  1    1   0    1
2777 //  1    1   1    1
2778 //
2779 
2780 uint Compile::eval_macro_logic_op(uint func, uint in1 , uint in2, uint in3) {
2781   int res = 0;
2782   for (int i = 0; i < 8; i++) {
2783     int bit1 = extract_bit(in1, i);
2784     int bit2 = extract_bit(in2, i);
2785     int bit3 = extract_bit(in3, i);
2786 
2787     int func_bit_pos = (bit1 << 2 | bit2 << 1 | bit3);
2788     int func_bit = extract_bit(func, func_bit_pos);
2789 
2790     res |= func_bit << i;
2791   }
2792   return res;
2793 }
2794 
2795 static uint eval_operand(Node* n, HashTable<Node*,uint>& eval_map) {
2796   assert(n != nullptr, "");
2797   assert(eval_map.contains(n), "absent");
2798   return *(eval_map.get(n));
2799 }
2800 
2801 static void eval_operands(Node* n,
2802                           uint& func1, uint& func2, uint& func3,
2803                           HashTable<Node*,uint>& eval_map) {
2804   assert(is_vector_bitwise_op(n), "");
2805 
2806   if (is_vector_unary_bitwise_op(n)) {
2807     Node* opnd = n->in(1);
2808     if (VectorNode::is_vector_bitwise_not_pattern(n) && VectorNode::is_all_ones_vector(opnd)) {
2809       opnd = n->in(2);
2810     }
2811     func1 = eval_operand(opnd, eval_map);
2812   } else if (is_vector_binary_bitwise_op(n)) {
2813     func1 = eval_operand(n->in(1), eval_map);
2814     func2 = eval_operand(n->in(2), eval_map);
2815   } else {
2816     assert(is_vector_ternary_bitwise_op(n), "unknown operation");
2817     func1 = eval_operand(n->in(1), eval_map);
2818     func2 = eval_operand(n->in(2), eval_map);
2819     func3 = eval_operand(n->in(3), eval_map);
2820   }
2821 }
2822 
2823 uint Compile::compute_truth_table(Unique_Node_List& partition, Unique_Node_List& inputs) {
2824   assert(inputs.size() <= 3, "sanity");
2825   ResourceMark rm;
2826   uint res = 0;
2827   HashTable<Node*,uint> eval_map;
2828 
2829   // Populate precomputed functions for inputs.
2830   // Each input corresponds to one column of 3 input truth-table.
2831   uint input_funcs[] = { 0xAA,   // (_, _, c) -> c
2832                          0xCC,   // (_, b, _) -> b
2833                          0xF0 }; // (a, _, _) -> a
2834   for (uint i = 0; i < inputs.size(); i++) {
2835     eval_map.put(inputs.at(i), input_funcs[2-i]);
2836   }
2837 
2838   for (uint i = 0; i < partition.size(); i++) {
2839     Node* n = partition.at(i);
2840 
2841     uint func1 = 0, func2 = 0, func3 = 0;
2842     eval_operands(n, func1, func2, func3, eval_map);
2843 
2844     switch (n->Opcode()) {
2845       case Op_OrV:
2846         assert(func3 == 0, "not binary");
2847         res = func1 | func2;
2848         break;
2849       case Op_AndV:
2850         assert(func3 == 0, "not binary");
2851         res = func1 & func2;
2852         break;
2853       case Op_XorV:
2854         if (VectorNode::is_vector_bitwise_not_pattern(n)) {
2855           assert(func2 == 0 && func3 == 0, "not unary");
2856           res = (~func1) & 0xFF;
2857         } else {
2858           assert(func3 == 0, "not binary");
2859           res = func1 ^ func2;
2860         }
2861         break;
2862       case Op_MacroLogicV:
2863         // Ordering of inputs may change during evaluation of sub-tree
2864         // containing MacroLogic node as a child node, thus a re-evaluation
2865         // makes sure that function is evaluated in context of current
2866         // inputs.
2867         res = eval_macro_logic_op(n->in(4)->get_int(), func1, func2, func3);
2868         break;
2869 
2870       default: assert(false, "not supported: %s", n->Name());
2871     }
2872     assert(res <= 0xFF, "invalid");
2873     eval_map.put(n, res);
2874   }
2875   return res;
2876 }
2877 
2878 // Criteria under which nodes gets packed into a macro logic node:-
2879 //  1) Parent and both child nodes are all unmasked or masked with
2880 //     same predicates.
2881 //  2) Masked parent can be packed with left child if it is predicated
2882 //     and both have same predicates.
2883 //  3) Masked parent can be packed with right child if its un-predicated
2884 //     or has matching predication condition.
2885 //  4) An unmasked parent can be packed with an unmasked child.
2886 bool Compile::compute_logic_cone(Node* n, Unique_Node_List& partition, Unique_Node_List& inputs) {
2887   assert(partition.size() == 0, "not empty");
2888   assert(inputs.size() == 0, "not empty");
2889   if (is_vector_ternary_bitwise_op(n)) {
2890     return false;
2891   }
2892 
2893   bool is_unary_op = is_vector_unary_bitwise_op(n);
2894   if (is_unary_op) {
2895     assert(collect_unique_inputs(n, inputs) == 1, "not unary");
2896     return false; // too few inputs
2897   }
2898 
2899   bool pack_left_child = true;
2900   bool pack_right_child = true;
2901 
2902   bool left_child_LOP = is_vector_bitwise_op(n->in(1));
2903   bool right_child_LOP = is_vector_bitwise_op(n->in(2));
2904 
2905   int left_child_input_cnt = 0;
2906   int right_child_input_cnt = 0;
2907 
2908   bool parent_is_predicated = n->is_predicated_vector();
2909   bool left_child_predicated = n->in(1)->is_predicated_vector();
2910   bool right_child_predicated = n->in(2)->is_predicated_vector();
2911 
2912   Node* parent_pred = parent_is_predicated ? n->in(n->req()-1) : nullptr;
2913   Node* left_child_pred = left_child_predicated ? n->in(1)->in(n->in(1)->req()-1) : nullptr;
2914   Node* right_child_pred = right_child_predicated ? n->in(1)->in(n->in(1)->req()-1) : nullptr;
2915 
2916   do {
2917     if (pack_left_child && left_child_LOP &&
2918         ((!parent_is_predicated && !left_child_predicated) ||
2919         ((parent_is_predicated && left_child_predicated &&
2920           parent_pred == left_child_pred)))) {
2921        partition.push(n->in(1));
2922        left_child_input_cnt = collect_unique_inputs(n->in(1), inputs);
2923     } else {
2924        inputs.push(n->in(1));
2925        left_child_input_cnt = 1;
2926     }
2927 
2928     if (pack_right_child && right_child_LOP &&
2929         (!right_child_predicated ||
2930          (right_child_predicated && parent_is_predicated &&
2931           parent_pred == right_child_pred))) {
2932        partition.push(n->in(2));
2933        right_child_input_cnt = collect_unique_inputs(n->in(2), inputs);
2934     } else {
2935        inputs.push(n->in(2));
2936        right_child_input_cnt = 1;
2937     }
2938 
2939     if (inputs.size() > 3) {
2940       assert(partition.size() > 0, "");
2941       inputs.clear();
2942       partition.clear();
2943       if (left_child_input_cnt > right_child_input_cnt) {
2944         pack_left_child = false;
2945       } else {
2946         pack_right_child = false;
2947       }
2948     } else {
2949       break;
2950     }
2951   } while(true);
2952 
2953   if(partition.size()) {
2954     partition.push(n);
2955   }
2956 
2957   return (partition.size() == 2 || partition.size() == 3) &&
2958          (inputs.size()    == 2 || inputs.size()    == 3);
2959 }
2960 
2961 void Compile::process_logic_cone_root(PhaseIterGVN &igvn, Node *n, VectorSet &visited) {
2962   assert(is_vector_bitwise_op(n), "not a root");
2963 
2964   visited.set(n->_idx);
2965 
2966   // 1) Do a DFS walk over the logic cone.
2967   for (uint i = 1; i < n->req(); i++) {
2968     Node* in = n->in(i);
2969     if (!visited.test(in->_idx) && is_vector_bitwise_op(in)) {
2970       process_logic_cone_root(igvn, in, visited);
2971     }
2972   }
2973 
2974   // 2) Bottom up traversal: Merge node[s] with
2975   // the parent to form macro logic node.
2976   Unique_Node_List partition;
2977   Unique_Node_List inputs;
2978   if (compute_logic_cone(n, partition, inputs)) {
2979     const TypeVect* vt = n->bottom_type()->is_vect();
2980     Node* pn = partition.at(partition.size() - 1);
2981     Node* mask = pn->is_predicated_vector() ? pn->in(pn->req()-1) : nullptr;
2982     if (mask == nullptr ||
2983         Matcher::match_rule_supported_vector_masked(Op_MacroLogicV, vt->length(), vt->element_basic_type())) {
2984       Node* macro_logic = xform_to_MacroLogicV(igvn, vt, partition, inputs);
2985       VectorNode::trace_new_vector(macro_logic, "MacroLogic");
2986       igvn.replace_node(n, macro_logic);
2987     }
2988   }
2989 }
2990 
2991 void Compile::optimize_logic_cones(PhaseIterGVN &igvn) {
2992   ResourceMark rm;
2993   if (Matcher::match_rule_supported(Op_MacroLogicV)) {
2994     Unique_Node_List list;
2995     collect_logic_cone_roots(list);
2996 
2997     while (list.size() > 0) {
2998       Node* n = list.pop();
2999       const TypeVect* vt = n->bottom_type()->is_vect();
3000       bool supported = Matcher::match_rule_supported_vector(Op_MacroLogicV, vt->length(), vt->element_basic_type());
3001       if (supported) {
3002         VectorSet visited(comp_arena());
3003         process_logic_cone_root(igvn, n, visited);
3004       }
3005     }
3006   }
3007 }
3008 
3009 //------------------------------Code_Gen---------------------------------------
3010 // Given a graph, generate code for it
3011 void Compile::Code_Gen() {
3012   if (failing()) {
3013     return;
3014   }
3015 
3016   // Perform instruction selection.  You might think we could reclaim Matcher
3017   // memory PDQ, but actually the Matcher is used in generating spill code.
3018   // Internals of the Matcher (including some VectorSets) must remain live
3019   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
3020   // set a bit in reclaimed memory.
3021 
3022   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
3023   // nodes.  Mapping is only valid at the root of each matched subtree.
3024   NOT_PRODUCT( verify_graph_edges(); )
3025 
3026   Matcher matcher;
3027   _matcher = &matcher;
3028   {
3029     TracePhase tp(_t_matcher);
3030     matcher.match();
3031     if (failing()) {
3032       return;
3033     }
3034   }
3035   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
3036   // nodes.  Mapping is only valid at the root of each matched subtree.
3037   NOT_PRODUCT( verify_graph_edges(); )
3038 
3039   // If you have too many nodes, or if matching has failed, bail out
3040   check_node_count(0, "out of nodes matching instructions");
3041   if (failing()) {
3042     return;
3043   }
3044 
3045   print_method(PHASE_MATCHING, 2);
3046 
3047   // Build a proper-looking CFG
3048   PhaseCFG cfg(node_arena(), root(), matcher);
3049   if (failing()) {
3050     return;
3051   }
3052   _cfg = &cfg;
3053   {
3054     TracePhase tp(_t_scheduler);
3055     bool success = cfg.do_global_code_motion();
3056     if (!success) {
3057       return;
3058     }
3059 
3060     print_method(PHASE_GLOBAL_CODE_MOTION, 2);
3061     NOT_PRODUCT( verify_graph_edges(); )
3062     cfg.verify();
3063     if (failing()) {
3064       return;
3065     }
3066   }
3067 
3068   PhaseChaitin regalloc(unique(), cfg, matcher, false);
3069   _regalloc = &regalloc;
3070   {
3071     TracePhase tp(_t_registerAllocation);
3072     // Perform register allocation.  After Chaitin, use-def chains are
3073     // no longer accurate (at spill code) and so must be ignored.
3074     // Node->LRG->reg mappings are still accurate.
3075     _regalloc->Register_Allocate();
3076 
3077     // Bail out if the allocator builds too many nodes
3078     if (failing()) {
3079       return;
3080     }
3081 
3082     print_method(PHASE_REGISTER_ALLOCATION, 2);
3083   }
3084 
3085   // Prior to register allocation we kept empty basic blocks in case the
3086   // the allocator needed a place to spill.  After register allocation we
3087   // are not adding any new instructions.  If any basic block is empty, we
3088   // can now safely remove it.
3089   {
3090     TracePhase tp(_t_blockOrdering);
3091     cfg.remove_empty_blocks();
3092     if (do_freq_based_layout()) {
3093       PhaseBlockLayout layout(cfg);
3094     } else {
3095       cfg.set_loop_alignment();
3096     }
3097     cfg.fixup_flow();
3098     cfg.remove_unreachable_blocks();
3099     cfg.verify_dominator_tree();
3100     print_method(PHASE_BLOCK_ORDERING, 3);
3101   }
3102 
3103   // Apply peephole optimizations
3104   if( OptoPeephole ) {
3105     TracePhase tp(_t_peephole);
3106     PhasePeephole peep( _regalloc, cfg);
3107     peep.do_transform();
3108     print_method(PHASE_PEEPHOLE, 3);
3109   }
3110 
3111   // Do late expand if CPU requires this.
3112   if (Matcher::require_postalloc_expand) {
3113     TracePhase tp(_t_postalloc_expand);
3114     cfg.postalloc_expand(_regalloc);
3115     print_method(PHASE_POSTALLOC_EXPAND, 3);
3116   }
3117 
3118 #ifdef ASSERT
3119   {
3120     CompilationMemoryStatistic::do_test_allocations();
3121     if (failing()) return;
3122   }
3123 #endif
3124 
3125   // Convert Nodes to instruction bits in a buffer
3126   {
3127     TracePhase tp(_t_output);
3128     PhaseOutput output;
3129     output.Output();
3130     if (failing())  return;
3131     output.install();
3132     print_method(PHASE_FINAL_CODE, 1); // Compile::_output is not null here
3133   }
3134 
3135   // He's dead, Jim.
3136   _cfg     = (PhaseCFG*)((intptr_t)0xdeadbeef);
3137   _regalloc = (PhaseChaitin*)((intptr_t)0xdeadbeef);
3138 }
3139 
3140 //------------------------------Final_Reshape_Counts---------------------------
3141 // This class defines counters to help identify when a method
3142 // may/must be executed using hardware with only 24-bit precision.
3143 struct Final_Reshape_Counts : public StackObj {
3144   int  _call_count;             // count non-inlined 'common' calls
3145   int  _float_count;            // count float ops requiring 24-bit precision
3146   int  _double_count;           // count double ops requiring more precision
3147   int  _java_call_count;        // count non-inlined 'java' calls
3148   int  _inner_loop_count;       // count loops which need alignment
3149   VectorSet _visited;           // Visitation flags
3150   Node_List _tests;             // Set of IfNodes & PCTableNodes
3151 
3152   Final_Reshape_Counts() :
3153     _call_count(0), _float_count(0), _double_count(0),
3154     _java_call_count(0), _inner_loop_count(0) { }
3155 
3156   void inc_call_count  () { _call_count  ++; }
3157   void inc_float_count () { _float_count ++; }
3158   void inc_double_count() { _double_count++; }
3159   void inc_java_call_count() { _java_call_count++; }
3160   void inc_inner_loop_count() { _inner_loop_count++; }
3161 
3162   int  get_call_count  () const { return _call_count  ; }
3163   int  get_float_count () const { return _float_count ; }
3164   int  get_double_count() const { return _double_count; }
3165   int  get_java_call_count() const { return _java_call_count; }
3166   int  get_inner_loop_count() const { return _inner_loop_count; }
3167 };
3168 
3169 //------------------------------final_graph_reshaping_impl----------------------
3170 // Implement items 1-5 from final_graph_reshaping below.
3171 void Compile::final_graph_reshaping_impl(Node *n, Final_Reshape_Counts& frc, Unique_Node_List& dead_nodes) {
3172 
3173   if ( n->outcnt() == 0 ) return; // dead node
3174   uint nop = n->Opcode();
3175 
3176   // Check for 2-input instruction with "last use" on right input.
3177   // Swap to left input.  Implements item (2).
3178   if( n->req() == 3 &&          // two-input instruction
3179       n->in(1)->outcnt() > 1 && // left use is NOT a last use
3180       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
3181       n->in(2)->outcnt() == 1 &&// right use IS a last use
3182       !n->in(2)->is_Con() ) {   // right use is not a constant
3183     // Check for commutative opcode
3184     switch( nop ) {
3185     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddL:
3186     case Op_MaxI:  case Op_MaxL:  case Op_MaxF:  case Op_MaxD:
3187     case Op_MinI:  case Op_MinL:  case Op_MinF:  case Op_MinD:
3188     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulL:
3189     case Op_AndL:  case Op_XorL:  case Op_OrL:
3190     case Op_AndI:  case Op_XorI:  case Op_OrI: {
3191       // Move "last use" input to left by swapping inputs
3192       n->swap_edges(1, 2);
3193       break;
3194     }
3195     default:
3196       break;
3197     }
3198   }
3199 
3200 #ifdef ASSERT
3201   if( n->is_Mem() ) {
3202     int alias_idx = get_alias_index(n->as_Mem()->adr_type());
3203     assert( n->in(0) != nullptr || alias_idx != Compile::AliasIdxRaw ||
3204             // oop will be recorded in oop map if load crosses safepoint
3205             (n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
3206                               LoadNode::is_immutable_value(n->in(MemNode::Address)))),
3207             "raw memory operations should have control edge");
3208   }
3209   if (n->is_MemBar()) {
3210     MemBarNode* mb = n->as_MemBar();
3211     if (mb->trailing_store() || mb->trailing_load_store()) {
3212       assert(mb->leading_membar()->trailing_membar() == mb, "bad membar pair");
3213       Node* mem = BarrierSet::barrier_set()->barrier_set_c2()->step_over_gc_barrier(mb->in(MemBarNode::Precedent));
3214       assert((mb->trailing_store() && mem->is_Store() && mem->as_Store()->is_release()) ||
3215              (mb->trailing_load_store() && mem->is_LoadStore()), "missing mem op");
3216     } else if (mb->leading()) {
3217       assert(mb->trailing_membar()->leading_membar() == mb, "bad membar pair");
3218     }
3219   }
3220 #endif
3221   // Count FPU ops and common calls, implements item (3)
3222   bool gc_handled = BarrierSet::barrier_set()->barrier_set_c2()->final_graph_reshaping(this, n, nop, dead_nodes);
3223   if (!gc_handled) {
3224     final_graph_reshaping_main_switch(n, frc, nop, dead_nodes);
3225   }
3226 
3227   // Collect CFG split points
3228   if (n->is_MultiBranch() && !n->is_RangeCheck()) {
3229     frc._tests.push(n);
3230   }
3231 }
3232 
3233 void Compile::handle_div_mod_op(Node* n, BasicType bt, bool is_unsigned) {
3234   if (!UseDivMod) {
3235     return;
3236   }
3237 
3238   // Check if "a % b" and "a / b" both exist
3239   Node* d = n->find_similar(Op_DivIL(bt, is_unsigned));
3240   if (d == nullptr) {
3241     return;
3242   }
3243 
3244   // Replace them with a fused divmod if supported
3245   if (Matcher::has_match_rule(Op_DivModIL(bt, is_unsigned))) {
3246     DivModNode* divmod = DivModNode::make(n, bt, is_unsigned);
3247     // If the divisor input for a Div (or Mod etc.) is not zero, then the control input of the Div is set to zero.
3248     // It could be that the divisor input is found not zero because its type is narrowed down by a CastII in the
3249     // subgraph for that input. Range check CastIIs are removed during final graph reshape. To preserve the dependency
3250     // carried by a CastII, precedence edges are added to the Div node. We need to transfer the precedence edges to the
3251     // DivMod node so the dependency is not lost.
3252     divmod->add_prec_from(n);
3253     divmod->add_prec_from(d);
3254     d->subsume_by(divmod->div_proj(), this);
3255     n->subsume_by(divmod->mod_proj(), this);
3256   } else {
3257     // Replace "a % b" with "a - ((a / b) * b)"
3258     Node* mult = MulNode::make(d, d->in(2), bt);
3259     Node* sub = SubNode::make(d->in(1), mult, bt);
3260     n->subsume_by(sub, this);
3261   }
3262 }
3263 
3264 void Compile::final_graph_reshaping_main_switch(Node* n, Final_Reshape_Counts& frc, uint nop, Unique_Node_List& dead_nodes) {
3265   switch( nop ) {
3266   // Count all float operations that may use FPU
3267   case Op_AddF:
3268   case Op_SubF:
3269   case Op_MulF:
3270   case Op_DivF:
3271   case Op_NegF:
3272   case Op_ModF:
3273   case Op_ConvI2F:
3274   case Op_ConF:
3275   case Op_CmpF:
3276   case Op_CmpF3:
3277   case Op_StoreF:
3278   case Op_LoadF:
3279   // case Op_ConvL2F: // longs are split into 32-bit halves
3280     frc.inc_float_count();
3281     break;
3282 
3283   case Op_ConvF2D:
3284   case Op_ConvD2F:
3285     frc.inc_float_count();
3286     frc.inc_double_count();
3287     break;
3288 
3289   // Count all double operations that may use FPU
3290   case Op_AddD:
3291   case Op_SubD:
3292   case Op_MulD:
3293   case Op_DivD:
3294   case Op_NegD:
3295   case Op_ModD:
3296   case Op_ConvI2D:
3297   case Op_ConvD2I:
3298   // case Op_ConvL2D: // handled by leaf call
3299   // case Op_ConvD2L: // handled by leaf call
3300   case Op_ConD:
3301   case Op_CmpD:
3302   case Op_CmpD3:
3303   case Op_StoreD:
3304   case Op_LoadD:
3305   case Op_LoadD_unaligned:
3306     frc.inc_double_count();
3307     break;
3308   case Op_Opaque1:              // Remove Opaque Nodes before matching
3309     n->subsume_by(n->in(1), this);
3310     break;
3311   case Op_CallLeafPure: {
3312     // If the pure call is not supported, then lower to a CallLeaf.
3313     if (!Matcher::match_rule_supported(Op_CallLeafPure)) {
3314       CallNode* call = n->as_Call();
3315       CallNode* new_call = new CallLeafNode(call->tf(), call->entry_point(),
3316                                             call->_name, TypeRawPtr::BOTTOM);
3317       new_call->init_req(TypeFunc::Control, call->in(TypeFunc::Control));
3318       new_call->init_req(TypeFunc::I_O, C->top());
3319       new_call->init_req(TypeFunc::Memory, C->top());
3320       new_call->init_req(TypeFunc::ReturnAdr, C->top());
3321       new_call->init_req(TypeFunc::FramePtr, C->top());
3322       for (unsigned int i = TypeFunc::Parms; i < call->tf()->domain()->cnt(); i++) {
3323         new_call->init_req(i, call->in(i));
3324       }
3325       n->subsume_by(new_call, this);
3326     }
3327     frc.inc_call_count();
3328     break;
3329   }
3330   case Op_CallStaticJava:
3331   case Op_CallJava:
3332   case Op_CallDynamicJava:
3333     frc.inc_java_call_count(); // Count java call site;
3334   case Op_CallRuntime:
3335   case Op_CallLeaf:
3336   case Op_CallLeafVector:
3337   case Op_CallLeafNoFP: {
3338     assert (n->is_Call(), "");
3339     CallNode *call = n->as_Call();
3340     // Count call sites where the FP mode bit would have to be flipped.
3341     // Do not count uncommon runtime calls:
3342     // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
3343     // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
3344     if (!call->is_CallStaticJava() || !call->as_CallStaticJava()->_name) {
3345       frc.inc_call_count();   // Count the call site
3346     } else {                  // See if uncommon argument is shared
3347       Node *n = call->in(TypeFunc::Parms);
3348       int nop = n->Opcode();
3349       // Clone shared simple arguments to uncommon calls, item (1).
3350       if (n->outcnt() > 1 &&
3351           !n->is_Proj() &&
3352           nop != Op_CreateEx &&
3353           nop != Op_CheckCastPP &&
3354           nop != Op_DecodeN &&
3355           nop != Op_DecodeNKlass &&
3356           !n->is_Mem() &&
3357           !n->is_Phi()) {
3358         Node *x = n->clone();
3359         call->set_req(TypeFunc::Parms, x);
3360       }
3361     }
3362     break;
3363   }
3364   case Op_StoreB:
3365   case Op_StoreC:
3366   case Op_StoreI:
3367   case Op_StoreL:
3368   case Op_CompareAndSwapB:
3369   case Op_CompareAndSwapS:
3370   case Op_CompareAndSwapI:
3371   case Op_CompareAndSwapL:
3372   case Op_CompareAndSwapP:
3373   case Op_CompareAndSwapN:
3374   case Op_WeakCompareAndSwapB:
3375   case Op_WeakCompareAndSwapS:
3376   case Op_WeakCompareAndSwapI:
3377   case Op_WeakCompareAndSwapL:
3378   case Op_WeakCompareAndSwapP:
3379   case Op_WeakCompareAndSwapN:
3380   case Op_CompareAndExchangeB:
3381   case Op_CompareAndExchangeS:
3382   case Op_CompareAndExchangeI:
3383   case Op_CompareAndExchangeL:
3384   case Op_CompareAndExchangeP:
3385   case Op_CompareAndExchangeN:
3386   case Op_GetAndAddS:
3387   case Op_GetAndAddB:
3388   case Op_GetAndAddI:
3389   case Op_GetAndAddL:
3390   case Op_GetAndSetS:
3391   case Op_GetAndSetB:
3392   case Op_GetAndSetI:
3393   case Op_GetAndSetL:
3394   case Op_GetAndSetP:
3395   case Op_GetAndSetN:
3396   case Op_StoreP:
3397   case Op_StoreN:
3398   case Op_StoreNKlass:
3399   case Op_LoadB:
3400   case Op_LoadUB:
3401   case Op_LoadUS:
3402   case Op_LoadI:
3403   case Op_LoadKlass:
3404   case Op_LoadNKlass:
3405   case Op_LoadL:
3406   case Op_LoadL_unaligned:
3407   case Op_LoadP:
3408   case Op_LoadN:
3409   case Op_LoadRange:
3410   case Op_LoadS:
3411     break;
3412 
3413   case Op_AddP: {               // Assert sane base pointers
3414     Node *addp = n->in(AddPNode::Address);
3415     assert(n->as_AddP()->address_input_has_same_base(), "Base pointers must match (addp %u)", addp->_idx );
3416 #ifdef _LP64
3417     if ((UseCompressedOops || UseCompressedClassPointers) &&
3418         addp->Opcode() == Op_ConP &&
3419         addp == n->in(AddPNode::Base) &&
3420         n->in(AddPNode::Offset)->is_Con()) {
3421       // If the transformation of ConP to ConN+DecodeN is beneficial depends
3422       // on the platform and on the compressed oops mode.
3423       // Use addressing with narrow klass to load with offset on x86.
3424       // Some platforms can use the constant pool to load ConP.
3425       // Do this transformation here since IGVN will convert ConN back to ConP.
3426       const Type* t = addp->bottom_type();
3427       bool is_oop   = t->isa_oopptr() != nullptr;
3428       bool is_klass = t->isa_klassptr() != nullptr;
3429 
3430       if ((is_oop   && UseCompressedOops          && Matcher::const_oop_prefer_decode()  ) ||
3431           (is_klass && UseCompressedClassPointers && Matcher::const_klass_prefer_decode() &&
3432            t->isa_klassptr()->exact_klass()->is_in_encoding_range())) {
3433         Node* nn = nullptr;
3434 
3435         int op = is_oop ? Op_ConN : Op_ConNKlass;
3436 
3437         // Look for existing ConN node of the same exact type.
3438         Node* r  = root();
3439         uint cnt = r->outcnt();
3440         for (uint i = 0; i < cnt; i++) {
3441           Node* m = r->raw_out(i);
3442           if (m!= nullptr && m->Opcode() == op &&
3443               m->bottom_type()->make_ptr() == t) {
3444             nn = m;
3445             break;
3446           }
3447         }
3448         if (nn != nullptr) {
3449           // Decode a narrow oop to match address
3450           // [R12 + narrow_oop_reg<<3 + offset]
3451           if (is_oop) {
3452             nn = new DecodeNNode(nn, t);
3453           } else {
3454             nn = new DecodeNKlassNode(nn, t);
3455           }
3456           // Check for succeeding AddP which uses the same Base.
3457           // Otherwise we will run into the assertion above when visiting that guy.
3458           for (uint i = 0; i < n->outcnt(); ++i) {
3459             Node *out_i = n->raw_out(i);
3460             if (out_i && out_i->is_AddP() && out_i->in(AddPNode::Base) == addp) {
3461               out_i->set_req(AddPNode::Base, nn);
3462 #ifdef ASSERT
3463               for (uint j = 0; j < out_i->outcnt(); ++j) {
3464                 Node *out_j = out_i->raw_out(j);
3465                 assert(out_j == nullptr || !out_j->is_AddP() || out_j->in(AddPNode::Base) != addp,
3466                        "more than 2 AddP nodes in a chain (out_j %u)", out_j->_idx);
3467               }
3468 #endif
3469             }
3470           }
3471           n->set_req(AddPNode::Base, nn);
3472           n->set_req(AddPNode::Address, nn);
3473           if (addp->outcnt() == 0) {
3474             addp->disconnect_inputs(this);
3475           }
3476         }
3477       }
3478     }
3479 #endif
3480     break;
3481   }
3482 
3483   case Op_CastPP: {
3484     // Remove CastPP nodes to gain more freedom during scheduling but
3485     // keep the dependency they encode as control or precedence edges
3486     // (if control is set already) on memory operations. Some CastPP
3487     // nodes don't have a control (don't carry a dependency): skip
3488     // those.
3489     if (n->in(0) != nullptr) {
3490       ResourceMark rm;
3491       Unique_Node_List wq;
3492       wq.push(n);
3493       for (uint next = 0; next < wq.size(); ++next) {
3494         Node *m = wq.at(next);
3495         for (DUIterator_Fast imax, i = m->fast_outs(imax); i < imax; i++) {
3496           Node* use = m->fast_out(i);
3497           if (use->is_Mem() || use->is_EncodeNarrowPtr()) {
3498             use->ensure_control_or_add_prec(n->in(0));
3499           } else {
3500             switch(use->Opcode()) {
3501             case Op_AddP:
3502             case Op_DecodeN:
3503             case Op_DecodeNKlass:
3504             case Op_CheckCastPP:
3505             case Op_CastPP:
3506               wq.push(use);
3507               break;
3508             }
3509           }
3510         }
3511       }
3512     }
3513     const bool is_LP64 = LP64_ONLY(true) NOT_LP64(false);
3514     if (is_LP64 && n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
3515       Node* in1 = n->in(1);
3516       const Type* t = n->bottom_type();
3517       Node* new_in1 = in1->clone();
3518       new_in1->as_DecodeN()->set_type(t);
3519 
3520       if (!Matcher::narrow_oop_use_complex_address()) {
3521         //
3522         // x86, ARM and friends can handle 2 adds in addressing mode
3523         // and Matcher can fold a DecodeN node into address by using
3524         // a narrow oop directly and do implicit null check in address:
3525         //
3526         // [R12 + narrow_oop_reg<<3 + offset]
3527         // NullCheck narrow_oop_reg
3528         //
3529         // On other platforms (Sparc) we have to keep new DecodeN node and
3530         // use it to do implicit null check in address:
3531         //
3532         // decode_not_null narrow_oop_reg, base_reg
3533         // [base_reg + offset]
3534         // NullCheck base_reg
3535         //
3536         // Pin the new DecodeN node to non-null path on these platform (Sparc)
3537         // to keep the information to which null check the new DecodeN node
3538         // corresponds to use it as value in implicit_null_check().
3539         //
3540         new_in1->set_req(0, n->in(0));
3541       }
3542 
3543       n->subsume_by(new_in1, this);
3544       if (in1->outcnt() == 0) {
3545         in1->disconnect_inputs(this);
3546       }
3547     } else {
3548       n->subsume_by(n->in(1), this);
3549       if (n->outcnt() == 0) {
3550         n->disconnect_inputs(this);
3551       }
3552     }
3553     break;
3554   }
3555   case Op_CastII: {
3556     n->as_CastII()->remove_range_check_cast(this);
3557     break;
3558   }
3559 #ifdef _LP64
3560   case Op_CmpP:
3561     // Do this transformation here to preserve CmpPNode::sub() and
3562     // other TypePtr related Ideal optimizations (for example, ptr nullness).
3563     if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
3564       Node* in1 = n->in(1);
3565       Node* in2 = n->in(2);
3566       if (!in1->is_DecodeNarrowPtr()) {
3567         in2 = in1;
3568         in1 = n->in(2);
3569       }
3570       assert(in1->is_DecodeNarrowPtr(), "sanity");
3571 
3572       Node* new_in2 = nullptr;
3573       if (in2->is_DecodeNarrowPtr()) {
3574         assert(in2->Opcode() == in1->Opcode(), "must be same node type");
3575         new_in2 = in2->in(1);
3576       } else if (in2->Opcode() == Op_ConP) {
3577         const Type* t = in2->bottom_type();
3578         if (t == TypePtr::NULL_PTR) {
3579           assert(in1->is_DecodeN(), "compare klass to null?");
3580           // Don't convert CmpP null check into CmpN if compressed
3581           // oops implicit null check is not generated.
3582           // This will allow to generate normal oop implicit null check.
3583           if (Matcher::gen_narrow_oop_implicit_null_checks())
3584             new_in2 = ConNode::make(TypeNarrowOop::NULL_PTR);
3585           //
3586           // This transformation together with CastPP transformation above
3587           // will generated code for implicit null checks for compressed oops.
3588           //
3589           // The original code after Optimize()
3590           //
3591           //    LoadN memory, narrow_oop_reg
3592           //    decode narrow_oop_reg, base_reg
3593           //    CmpP base_reg, nullptr
3594           //    CastPP base_reg // NotNull
3595           //    Load [base_reg + offset], val_reg
3596           //
3597           // after these transformations will be
3598           //
3599           //    LoadN memory, narrow_oop_reg
3600           //    CmpN narrow_oop_reg, nullptr
3601           //    decode_not_null narrow_oop_reg, base_reg
3602           //    Load [base_reg + offset], val_reg
3603           //
3604           // and the uncommon path (== nullptr) will use narrow_oop_reg directly
3605           // since narrow oops can be used in debug info now (see the code in
3606           // final_graph_reshaping_walk()).
3607           //
3608           // At the end the code will be matched to
3609           // on x86:
3610           //
3611           //    Load_narrow_oop memory, narrow_oop_reg
3612           //    Load [R12 + narrow_oop_reg<<3 + offset], val_reg
3613           //    NullCheck narrow_oop_reg
3614           //
3615           // and on sparc:
3616           //
3617           //    Load_narrow_oop memory, narrow_oop_reg
3618           //    decode_not_null narrow_oop_reg, base_reg
3619           //    Load [base_reg + offset], val_reg
3620           //    NullCheck base_reg
3621           //
3622         } else if (t->isa_oopptr()) {
3623           new_in2 = ConNode::make(t->make_narrowoop());
3624         } else if (t->isa_klassptr()) {
3625           ciKlass* klass = t->is_klassptr()->exact_klass();
3626           if (klass->is_in_encoding_range()) {
3627             new_in2 = ConNode::make(t->make_narrowklass());
3628           }
3629         }
3630       }
3631       if (new_in2 != nullptr) {
3632         Node* cmpN = new CmpNNode(in1->in(1), new_in2);
3633         n->subsume_by(cmpN, this);
3634         if (in1->outcnt() == 0) {
3635           in1->disconnect_inputs(this);
3636         }
3637         if (in2->outcnt() == 0) {
3638           in2->disconnect_inputs(this);
3639         }
3640       }
3641     }
3642     break;
3643 
3644   case Op_DecodeN:
3645   case Op_DecodeNKlass:
3646     assert(!n->in(1)->is_EncodeNarrowPtr(), "should be optimized out");
3647     // DecodeN could be pinned when it can't be fold into
3648     // an address expression, see the code for Op_CastPP above.
3649     assert(n->in(0) == nullptr || (UseCompressedOops && !Matcher::narrow_oop_use_complex_address()), "no control");
3650     break;
3651 
3652   case Op_EncodeP:
3653   case Op_EncodePKlass: {
3654     Node* in1 = n->in(1);
3655     if (in1->is_DecodeNarrowPtr()) {
3656       n->subsume_by(in1->in(1), this);
3657     } else if (in1->Opcode() == Op_ConP) {
3658       const Type* t = in1->bottom_type();
3659       if (t == TypePtr::NULL_PTR) {
3660         assert(t->isa_oopptr(), "null klass?");
3661         n->subsume_by(ConNode::make(TypeNarrowOop::NULL_PTR), this);
3662       } else if (t->isa_oopptr()) {
3663         n->subsume_by(ConNode::make(t->make_narrowoop()), this);
3664       } else if (t->isa_klassptr()) {
3665         ciKlass* klass = t->is_klassptr()->exact_klass();
3666         if (klass->is_in_encoding_range()) {
3667           n->subsume_by(ConNode::make(t->make_narrowklass()), this);
3668         } else {
3669           assert(false, "unencodable klass in ConP -> EncodeP");
3670           C->record_failure("unencodable klass in ConP -> EncodeP");
3671         }
3672       }
3673     }
3674     if (in1->outcnt() == 0) {
3675       in1->disconnect_inputs(this);
3676     }
3677     break;
3678   }
3679 
3680   case Op_Proj: {
3681     if (OptimizeStringConcat || IncrementalInline) {
3682       ProjNode* proj = n->as_Proj();
3683       if (proj->_is_io_use) {
3684         assert(proj->_con == TypeFunc::I_O || proj->_con == TypeFunc::Memory, "");
3685         // Separate projections were used for the exception path which
3686         // are normally removed by a late inline.  If it wasn't inlined
3687         // then they will hang around and should just be replaced with
3688         // the original one. Merge them.
3689         Node* non_io_proj = proj->in(0)->as_Multi()->proj_out_or_null(proj->_con, false /*is_io_use*/);
3690         if (non_io_proj  != nullptr) {
3691           proj->subsume_by(non_io_proj , this);
3692         }
3693       }
3694     }
3695     break;
3696   }
3697 
3698   case Op_Phi:
3699     if (n->as_Phi()->bottom_type()->isa_narrowoop() || n->as_Phi()->bottom_type()->isa_narrowklass()) {
3700       // The EncodeP optimization may create Phi with the same edges
3701       // for all paths. It is not handled well by Register Allocator.
3702       Node* unique_in = n->in(1);
3703       assert(unique_in != nullptr, "");
3704       uint cnt = n->req();
3705       for (uint i = 2; i < cnt; i++) {
3706         Node* m = n->in(i);
3707         assert(m != nullptr, "");
3708         if (unique_in != m)
3709           unique_in = nullptr;
3710       }
3711       if (unique_in != nullptr) {
3712         n->subsume_by(unique_in, this);
3713       }
3714     }
3715     break;
3716 
3717 #endif
3718 
3719   case Op_ModI:
3720     handle_div_mod_op(n, T_INT, false);
3721     break;
3722 
3723   case Op_ModL:
3724     handle_div_mod_op(n, T_LONG, false);
3725     break;
3726 
3727   case Op_UModI:
3728     handle_div_mod_op(n, T_INT, true);
3729     break;
3730 
3731   case Op_UModL:
3732     handle_div_mod_op(n, T_LONG, true);
3733     break;
3734 
3735   case Op_LoadVector:
3736   case Op_StoreVector:
3737 #ifdef ASSERT
3738     // Add VerifyVectorAlignment node between adr and load / store.
3739     if (VerifyAlignVector && Matcher::has_match_rule(Op_VerifyVectorAlignment)) {
3740       bool must_verify_alignment = n->is_LoadVector() ? n->as_LoadVector()->must_verify_alignment() :
3741                                                         n->as_StoreVector()->must_verify_alignment();
3742       if (must_verify_alignment) {
3743         jlong vector_width = n->is_LoadVector() ? n->as_LoadVector()->memory_size() :
3744                                                   n->as_StoreVector()->memory_size();
3745         // The memory access should be aligned to the vector width in bytes.
3746         // However, the underlying array is possibly less well aligned, but at least
3747         // to ObjectAlignmentInBytes. Hence, even if multiple arrays are accessed in
3748         // a loop we can expect at least the following alignment:
3749         jlong guaranteed_alignment = MIN2(vector_width, (jlong)ObjectAlignmentInBytes);
3750         assert(2 <= guaranteed_alignment && guaranteed_alignment <= 64, "alignment must be in range");
3751         assert(is_power_of_2(guaranteed_alignment), "alignment must be power of 2");
3752         // Create mask from alignment. e.g. 0b1000 -> 0b0111
3753         jlong mask = guaranteed_alignment - 1;
3754         Node* mask_con = ConLNode::make(mask);
3755         VerifyVectorAlignmentNode* va = new VerifyVectorAlignmentNode(n->in(MemNode::Address), mask_con);
3756         n->set_req(MemNode::Address, va);
3757       }
3758     }
3759 #endif
3760     break;
3761 
3762   case Op_LoadVectorGather:
3763   case Op_StoreVectorScatter:
3764   case Op_LoadVectorGatherMasked:
3765   case Op_StoreVectorScatterMasked:
3766   case Op_VectorCmpMasked:
3767   case Op_VectorMaskGen:
3768   case Op_LoadVectorMasked:
3769   case Op_StoreVectorMasked:
3770     break;
3771 
3772   case Op_AddReductionVI:
3773   case Op_AddReductionVL:
3774   case Op_AddReductionVF:
3775   case Op_AddReductionVD:
3776   case Op_MulReductionVI:
3777   case Op_MulReductionVL:
3778   case Op_MulReductionVF:
3779   case Op_MulReductionVD:
3780   case Op_MinReductionV:
3781   case Op_MaxReductionV:
3782   case Op_UMinReductionV:
3783   case Op_UMaxReductionV:
3784   case Op_AndReductionV:
3785   case Op_OrReductionV:
3786   case Op_XorReductionV:
3787     break;
3788 
3789   case Op_PackB:
3790   case Op_PackS:
3791   case Op_PackI:
3792   case Op_PackF:
3793   case Op_PackL:
3794   case Op_PackD:
3795     if (n->req()-1 > 2) {
3796       // Replace many operand PackNodes with a binary tree for matching
3797       PackNode* p = (PackNode*) n;
3798       Node* btp = p->binary_tree_pack(1, n->req());
3799       n->subsume_by(btp, this);
3800     }
3801     break;
3802   case Op_Loop:
3803     assert(!n->as_Loop()->is_loop_nest_inner_loop() || _loop_opts_cnt == 0, "should have been turned into a counted loop");
3804   case Op_CountedLoop:
3805   case Op_LongCountedLoop:
3806   case Op_OuterStripMinedLoop:
3807     if (n->as_Loop()->is_inner_loop()) {
3808       frc.inc_inner_loop_count();
3809     }
3810     n->as_Loop()->verify_strip_mined(0);
3811     break;
3812   case Op_LShiftI:
3813   case Op_RShiftI:
3814   case Op_URShiftI:
3815   case Op_LShiftL:
3816   case Op_RShiftL:
3817   case Op_URShiftL:
3818     if (Matcher::need_masked_shift_count) {
3819       // The cpu's shift instructions don't restrict the count to the
3820       // lower 5/6 bits. We need to do the masking ourselves.
3821       Node* in2 = n->in(2);
3822       juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
3823       const TypeInt* t = in2->find_int_type();
3824       if (t != nullptr && t->is_con()) {
3825         juint shift = t->get_con();
3826         if (shift > mask) { // Unsigned cmp
3827           n->set_req(2, ConNode::make(TypeInt::make(shift & mask)));
3828         }
3829       } else {
3830         if (t == nullptr || t->_lo < 0 || t->_hi > (int)mask) {
3831           Node* shift = new AndINode(in2, ConNode::make(TypeInt::make(mask)));
3832           n->set_req(2, shift);
3833         }
3834       }
3835       if (in2->outcnt() == 0) { // Remove dead node
3836         in2->disconnect_inputs(this);
3837       }
3838     }
3839     break;
3840   case Op_MemBarStoreStore:
3841   case Op_MemBarRelease:
3842     // Break the link with AllocateNode: it is no longer useful and
3843     // confuses register allocation.
3844     if (n->req() > MemBarNode::Precedent) {
3845       n->set_req(MemBarNode::Precedent, top());
3846     }
3847     break;
3848   case Op_MemBarAcquire: {
3849     if (n->as_MemBar()->trailing_load() && n->req() > MemBarNode::Precedent) {
3850       // At parse time, the trailing MemBarAcquire for a volatile load
3851       // is created with an edge to the load. After optimizations,
3852       // that input may be a chain of Phis. If those phis have no
3853       // other use, then the MemBarAcquire keeps them alive and
3854       // register allocation can be confused.
3855       dead_nodes.push(n->in(MemBarNode::Precedent));
3856       n->set_req(MemBarNode::Precedent, top());
3857     }
3858     break;
3859   }
3860   case Op_Blackhole:
3861     break;
3862   case Op_RangeCheck: {
3863     RangeCheckNode* rc = n->as_RangeCheck();
3864     Node* iff = new IfNode(rc->in(0), rc->in(1), rc->_prob, rc->_fcnt);
3865     n->subsume_by(iff, this);
3866     frc._tests.push(iff);
3867     break;
3868   }
3869   case Op_ConvI2L: {
3870     if (!Matcher::convi2l_type_required) {
3871       // Code generation on some platforms doesn't need accurate
3872       // ConvI2L types. Widening the type can help remove redundant
3873       // address computations.
3874       n->as_Type()->set_type(TypeLong::INT);
3875       ResourceMark rm;
3876       Unique_Node_List wq;
3877       wq.push(n);
3878       for (uint next = 0; next < wq.size(); next++) {
3879         Node *m = wq.at(next);
3880 
3881         for(;;) {
3882           // Loop over all nodes with identical inputs edges as m
3883           Node* k = m->find_similar(m->Opcode());
3884           if (k == nullptr) {
3885             break;
3886           }
3887           // Push their uses so we get a chance to remove node made
3888           // redundant
3889           for (DUIterator_Fast imax, i = k->fast_outs(imax); i < imax; i++) {
3890             Node* u = k->fast_out(i);
3891             if (u->Opcode() == Op_LShiftL ||
3892                 u->Opcode() == Op_AddL ||
3893                 u->Opcode() == Op_SubL ||
3894                 u->Opcode() == Op_AddP) {
3895               wq.push(u);
3896             }
3897           }
3898           // Replace all nodes with identical edges as m with m
3899           k->subsume_by(m, this);
3900         }
3901       }
3902     }
3903     break;
3904   }
3905   case Op_CmpUL: {
3906     if (!Matcher::has_match_rule(Op_CmpUL)) {
3907       // No support for unsigned long comparisons
3908       ConINode* sign_pos = new ConINode(TypeInt::make(BitsPerLong - 1));
3909       Node* sign_bit_mask = new RShiftLNode(n->in(1), sign_pos);
3910       Node* orl = new OrLNode(n->in(1), sign_bit_mask);
3911       ConLNode* remove_sign_mask = new ConLNode(TypeLong::make(max_jlong));
3912       Node* andl = new AndLNode(orl, remove_sign_mask);
3913       Node* cmp = new CmpLNode(andl, n->in(2));
3914       n->subsume_by(cmp, this);
3915     }
3916     break;
3917   }
3918 #ifdef ASSERT
3919   case Op_ConNKlass: {
3920     const TypePtr* tp = n->as_Type()->type()->make_ptr();
3921     ciKlass* klass = tp->is_klassptr()->exact_klass();
3922     assert(klass->is_in_encoding_range(), "klass cannot be compressed");
3923     break;
3924   }
3925 #endif
3926   default:
3927     assert(!n->is_Call(), "");
3928     assert(!n->is_Mem(), "");
3929     assert(nop != Op_ProfileBoolean, "should be eliminated during IGVN");
3930     break;
3931   }
3932 }
3933 
3934 //------------------------------final_graph_reshaping_walk---------------------
3935 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
3936 // requires that the walk visits a node's inputs before visiting the node.
3937 void Compile::final_graph_reshaping_walk(Node_Stack& nstack, Node* root, Final_Reshape_Counts& frc, Unique_Node_List& dead_nodes) {
3938   Unique_Node_List sfpt;
3939 
3940   frc._visited.set(root->_idx); // first, mark node as visited
3941   uint cnt = root->req();
3942   Node *n = root;
3943   uint  i = 0;
3944   while (true) {
3945     if (i < cnt) {
3946       // Place all non-visited non-null inputs onto stack
3947       Node* m = n->in(i);
3948       ++i;
3949       if (m != nullptr && !frc._visited.test_set(m->_idx)) {
3950         if (m->is_SafePoint() && m->as_SafePoint()->jvms() != nullptr) {
3951           // compute worst case interpreter size in case of a deoptimization
3952           update_interpreter_frame_size(m->as_SafePoint()->jvms()->interpreter_frame_size());
3953 
3954           sfpt.push(m);
3955         }
3956         cnt = m->req();
3957         nstack.push(n, i); // put on stack parent and next input's index
3958         n = m;
3959         i = 0;
3960       }
3961     } else {
3962       // Now do post-visit work
3963       final_graph_reshaping_impl(n, frc, dead_nodes);
3964       if (nstack.is_empty())
3965         break;             // finished
3966       n = nstack.node();   // Get node from stack
3967       cnt = n->req();
3968       i = nstack.index();
3969       nstack.pop();        // Shift to the next node on stack
3970     }
3971   }
3972 
3973   // Skip next transformation if compressed oops are not used.
3974   if ((UseCompressedOops && !Matcher::gen_narrow_oop_implicit_null_checks()) ||
3975       (!UseCompressedOops && !UseCompressedClassPointers))
3976     return;
3977 
3978   // Go over safepoints nodes to skip DecodeN/DecodeNKlass nodes for debug edges.
3979   // It could be done for an uncommon traps or any safepoints/calls
3980   // if the DecodeN/DecodeNKlass node is referenced only in a debug info.
3981   while (sfpt.size() > 0) {
3982     n = sfpt.pop();
3983     JVMState *jvms = n->as_SafePoint()->jvms();
3984     assert(jvms != nullptr, "sanity");
3985     int start = jvms->debug_start();
3986     int end   = n->req();
3987     bool is_uncommon = (n->is_CallStaticJava() &&
3988                         n->as_CallStaticJava()->uncommon_trap_request() != 0);
3989     for (int j = start; j < end; j++) {
3990       Node* in = n->in(j);
3991       if (in->is_DecodeNarrowPtr()) {
3992         bool safe_to_skip = true;
3993         if (!is_uncommon ) {
3994           // Is it safe to skip?
3995           for (uint i = 0; i < in->outcnt(); i++) {
3996             Node* u = in->raw_out(i);
3997             if (!u->is_SafePoint() ||
3998                 (u->is_Call() && u->as_Call()->has_non_debug_use(n))) {
3999               safe_to_skip = false;
4000             }
4001           }
4002         }
4003         if (safe_to_skip) {
4004           n->set_req(j, in->in(1));
4005         }
4006         if (in->outcnt() == 0) {
4007           in->disconnect_inputs(this);
4008         }
4009       }
4010     }
4011   }
4012 }
4013 
4014 //------------------------------final_graph_reshaping--------------------------
4015 // Final Graph Reshaping.
4016 //
4017 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
4018 //     and not commoned up and forced early.  Must come after regular
4019 //     optimizations to avoid GVN undoing the cloning.  Clone constant
4020 //     inputs to Loop Phis; these will be split by the allocator anyways.
4021 //     Remove Opaque nodes.
4022 // (2) Move last-uses by commutative operations to the left input to encourage
4023 //     Intel update-in-place two-address operations and better register usage
4024 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
4025 //     calls canonicalizing them back.
4026 // (3) Count the number of double-precision FP ops, single-precision FP ops
4027 //     and call sites.  On Intel, we can get correct rounding either by
4028 //     forcing singles to memory (requires extra stores and loads after each
4029 //     FP bytecode) or we can set a rounding mode bit (requires setting and
4030 //     clearing the mode bit around call sites).  The mode bit is only used
4031 //     if the relative frequency of single FP ops to calls is low enough.
4032 //     This is a key transform for SPEC mpeg_audio.
4033 // (4) Detect infinite loops; blobs of code reachable from above but not
4034 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
4035 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
4036 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
4037 //     Detection is by looking for IfNodes where only 1 projection is
4038 //     reachable from below or CatchNodes missing some targets.
4039 // (5) Assert for insane oop offsets in debug mode.
4040 
4041 bool Compile::final_graph_reshaping() {
4042   // an infinite loop may have been eliminated by the optimizer,
4043   // in which case the graph will be empty.
4044   if (root()->req() == 1) {
4045     // Do not compile method that is only a trivial infinite loop,
4046     // since the content of the loop may have been eliminated.
4047     record_method_not_compilable("trivial infinite loop");
4048     return true;
4049   }
4050 
4051   // Expensive nodes have their control input set to prevent the GVN
4052   // from freely commoning them. There's no GVN beyond this point so
4053   // no need to keep the control input. We want the expensive nodes to
4054   // be freely moved to the least frequent code path by gcm.
4055   assert(OptimizeExpensiveOps || expensive_count() == 0, "optimization off but list non empty?");
4056   for (int i = 0; i < expensive_count(); i++) {
4057     _expensive_nodes.at(i)->set_req(0, nullptr);
4058   }
4059 
4060   Final_Reshape_Counts frc;
4061 
4062   // Visit everybody reachable!
4063   // Allocate stack of size C->live_nodes()/2 to avoid frequent realloc
4064   Node_Stack nstack(live_nodes() >> 1);
4065   Unique_Node_List dead_nodes;
4066   final_graph_reshaping_walk(nstack, root(), frc, dead_nodes);
4067 
4068   // Check for unreachable (from below) code (i.e., infinite loops).
4069   for( uint i = 0; i < frc._tests.size(); i++ ) {
4070     MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
4071     // Get number of CFG targets.
4072     // Note that PCTables include exception targets after calls.
4073     uint required_outcnt = n->required_outcnt();
4074     if (n->outcnt() != required_outcnt) {
4075       // Check for a few special cases.  Rethrow Nodes never take the
4076       // 'fall-thru' path, so expected kids is 1 less.
4077       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
4078         if (n->in(0)->in(0)->is_Call()) {
4079           CallNode* call = n->in(0)->in(0)->as_Call();
4080           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
4081             required_outcnt--;      // Rethrow always has 1 less kid
4082           } else if (call->req() > TypeFunc::Parms &&
4083                      call->is_CallDynamicJava()) {
4084             // Check for null receiver. In such case, the optimizer has
4085             // detected that the virtual call will always result in a null
4086             // pointer exception. The fall-through projection of this CatchNode
4087             // will not be populated.
4088             Node* arg0 = call->in(TypeFunc::Parms);
4089             if (arg0->is_Type() &&
4090                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
4091               required_outcnt--;
4092             }
4093           } else if (call->entry_point() == OptoRuntime::new_array_Java() ||
4094                      call->entry_point() == OptoRuntime::new_array_nozero_Java()) {
4095             // Check for illegal array length. In such case, the optimizer has
4096             // detected that the allocation attempt will always result in an
4097             // exception. There is no fall-through projection of this CatchNode .
4098             assert(call->is_CallStaticJava(), "static call expected");
4099             assert(call->req() == call->jvms()->endoff() + 1, "missing extra input");
4100             uint valid_length_test_input = call->req() - 1;
4101             Node* valid_length_test = call->in(valid_length_test_input);
4102             call->del_req(valid_length_test_input);
4103             if (valid_length_test->find_int_con(1) == 0) {
4104               required_outcnt--;
4105             }
4106             dead_nodes.push(valid_length_test);
4107             assert(n->outcnt() == required_outcnt, "malformed control flow");
4108             continue;
4109           }
4110         }
4111       }
4112 
4113       // Recheck with a better notion of 'required_outcnt'
4114       if (n->outcnt() != required_outcnt) {
4115         record_method_not_compilable("malformed control flow");
4116         return true;            // Not all targets reachable!
4117       }
4118     } else if (n->is_PCTable() && n->in(0) && n->in(0)->in(0) && n->in(0)->in(0)->is_Call()) {
4119       CallNode* call = n->in(0)->in(0)->as_Call();
4120       if (call->entry_point() == OptoRuntime::new_array_Java() ||
4121           call->entry_point() == OptoRuntime::new_array_nozero_Java()) {
4122         assert(call->is_CallStaticJava(), "static call expected");
4123         assert(call->req() == call->jvms()->endoff() + 1, "missing extra input");
4124         uint valid_length_test_input = call->req() - 1;
4125         dead_nodes.push(call->in(valid_length_test_input));
4126         call->del_req(valid_length_test_input); // valid length test useless now
4127       }
4128     }
4129     // Check that I actually visited all kids.  Unreached kids
4130     // must be infinite loops.
4131     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
4132       if (!frc._visited.test(n->fast_out(j)->_idx)) {
4133         record_method_not_compilable("infinite loop");
4134         return true;            // Found unvisited kid; must be unreach
4135       }
4136 
4137     // Here so verification code in final_graph_reshaping_walk()
4138     // always see an OuterStripMinedLoopEnd
4139     if (n->is_OuterStripMinedLoopEnd() || n->is_LongCountedLoopEnd()) {
4140       IfNode* init_iff = n->as_If();
4141       Node* iff = new IfNode(init_iff->in(0), init_iff->in(1), init_iff->_prob, init_iff->_fcnt);
4142       n->subsume_by(iff, this);
4143     }
4144   }
4145 
4146   while (dead_nodes.size() > 0) {
4147     Node* m = dead_nodes.pop();
4148     if (m->outcnt() == 0 && m != top()) {
4149       for (uint j = 0; j < m->req(); j++) {
4150         Node* in = m->in(j);
4151         if (in != nullptr) {
4152           dead_nodes.push(in);
4153         }
4154       }
4155       m->disconnect_inputs(this);
4156     }
4157   }
4158 
4159   set_java_calls(frc.get_java_call_count());
4160   set_inner_loops(frc.get_inner_loop_count());
4161 
4162   // No infinite loops, no reason to bail out.
4163   return false;
4164 }
4165 
4166 //-----------------------------too_many_traps----------------------------------
4167 // Report if there are too many traps at the current method and bci.
4168 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
4169 bool Compile::too_many_traps(ciMethod* method,
4170                              int bci,
4171                              Deoptimization::DeoptReason reason) {
4172   ciMethodData* md = method->method_data();
4173   if (md->is_empty()) {
4174     // Assume the trap has not occurred, or that it occurred only
4175     // because of a transient condition during start-up in the interpreter.
4176     return false;
4177   }
4178   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : nullptr;
4179   if (md->has_trap_at(bci, m, reason) != 0) {
4180     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
4181     // Also, if there are multiple reasons, or if there is no per-BCI record,
4182     // assume the worst.
4183     if (log())
4184       log()->elem("observe trap='%s' count='%d'",
4185                   Deoptimization::trap_reason_name(reason),
4186                   md->trap_count(reason));
4187     return true;
4188   } else {
4189     // Ignore method/bci and see if there have been too many globally.
4190     return too_many_traps(reason, md);
4191   }
4192 }
4193 
4194 // Less-accurate variant which does not require a method and bci.
4195 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
4196                              ciMethodData* logmd) {
4197   if (trap_count(reason) >= Deoptimization::per_method_trap_limit(reason)) {
4198     // Too many traps globally.
4199     // Note that we use cumulative trap_count, not just md->trap_count.
4200     if (log()) {
4201       int mcount = (logmd == nullptr)? -1: (int)logmd->trap_count(reason);
4202       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
4203                   Deoptimization::trap_reason_name(reason),
4204                   mcount, trap_count(reason));
4205     }
4206     return true;
4207   } else {
4208     // The coast is clear.
4209     return false;
4210   }
4211 }
4212 
4213 //--------------------------too_many_recompiles--------------------------------
4214 // Report if there are too many recompiles at the current method and bci.
4215 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
4216 // Is not eager to return true, since this will cause the compiler to use
4217 // Action_none for a trap point, to avoid too many recompilations.
4218 bool Compile::too_many_recompiles(ciMethod* method,
4219                                   int bci,
4220                                   Deoptimization::DeoptReason reason) {
4221   ciMethodData* md = method->method_data();
4222   if (md->is_empty()) {
4223     // Assume the trap has not occurred, or that it occurred only
4224     // because of a transient condition during start-up in the interpreter.
4225     return false;
4226   }
4227   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
4228   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
4229   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
4230   Deoptimization::DeoptReason per_bc_reason
4231     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
4232   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : nullptr;
4233   if ((per_bc_reason == Deoptimization::Reason_none
4234        || md->has_trap_at(bci, m, reason) != 0)
4235       // The trap frequency measure we care about is the recompile count:
4236       && md->trap_recompiled_at(bci, m)
4237       && md->overflow_recompile_count() >= bc_cutoff) {
4238     // Do not emit a trap here if it has already caused recompilations.
4239     // Also, if there are multiple reasons, or if there is no per-BCI record,
4240     // assume the worst.
4241     if (log())
4242       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
4243                   Deoptimization::trap_reason_name(reason),
4244                   md->trap_count(reason),
4245                   md->overflow_recompile_count());
4246     return true;
4247   } else if (trap_count(reason) != 0
4248              && decompile_count() >= m_cutoff) {
4249     // Too many recompiles globally, and we have seen this sort of trap.
4250     // Use cumulative decompile_count, not just md->decompile_count.
4251     if (log())
4252       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
4253                   Deoptimization::trap_reason_name(reason),
4254                   md->trap_count(reason), trap_count(reason),
4255                   md->decompile_count(), decompile_count());
4256     return true;
4257   } else {
4258     // The coast is clear.
4259     return false;
4260   }
4261 }
4262 
4263 // Compute when not to trap. Used by matching trap based nodes and
4264 // NullCheck optimization.
4265 void Compile::set_allowed_deopt_reasons() {
4266   _allowed_reasons = 0;
4267   if (is_method_compilation()) {
4268     for (int rs = (int)Deoptimization::Reason_none+1; rs < Compile::trapHistLength; rs++) {
4269       assert(rs < BitsPerInt, "recode bit map");
4270       if (!too_many_traps((Deoptimization::DeoptReason) rs)) {
4271         _allowed_reasons |= nth_bit(rs);
4272       }
4273     }
4274   }
4275 }
4276 
4277 bool Compile::needs_clinit_barrier(ciMethod* method, ciMethod* accessing_method) {
4278   return method->is_static() && needs_clinit_barrier(method->holder(), accessing_method);
4279 }
4280 
4281 bool Compile::needs_clinit_barrier(ciField* field, ciMethod* accessing_method) {
4282   return field->is_static() && needs_clinit_barrier(field->holder(), accessing_method);
4283 }
4284 
4285 bool Compile::needs_clinit_barrier(ciInstanceKlass* holder, ciMethod* accessing_method) {
4286   if (holder->is_initialized()) {
4287     return false;
4288   }
4289   if (holder->is_being_initialized()) {
4290     if (accessing_method->holder() == holder) {
4291       // Access inside a class. The barrier can be elided when access happens in <clinit>,
4292       // <init>, or a static method. In all those cases, there was an initialization
4293       // barrier on the holder klass passed.
4294       if (accessing_method->is_static_initializer() ||
4295           accessing_method->is_object_initializer() ||
4296           accessing_method->is_static()) {
4297         return false;
4298       }
4299     } else if (accessing_method->holder()->is_subclass_of(holder)) {
4300       // Access from a subclass. The barrier can be elided only when access happens in <clinit>.
4301       // In case of <init> or a static method, the barrier is on the subclass is not enough:
4302       // child class can become fully initialized while its parent class is still being initialized.
4303       if (accessing_method->is_static_initializer()) {
4304         return false;
4305       }
4306     }
4307     ciMethod* root = method(); // the root method of compilation
4308     if (root != accessing_method) {
4309       return needs_clinit_barrier(holder, root); // check access in the context of compilation root
4310     }
4311   }
4312   return true;
4313 }
4314 
4315 #ifndef PRODUCT
4316 //------------------------------verify_bidirectional_edges---------------------
4317 // For each input edge to a node (ie - for each Use-Def edge), verify that
4318 // there is a corresponding Def-Use edge.
4319 void Compile::verify_bidirectional_edges(Unique_Node_List& visited, const Unique_Node_List* root_and_safepoints) const {
4320   // Allocate stack of size C->live_nodes()/16 to avoid frequent realloc
4321   uint stack_size = live_nodes() >> 4;
4322   Node_List nstack(MAX2(stack_size, (uint) OptoNodeListSize));
4323   if (root_and_safepoints != nullptr) {
4324     assert(root_and_safepoints->member(_root), "root is not in root_and_safepoints");
4325     for (uint i = 0, limit = root_and_safepoints->size(); i < limit; i++) {
4326       Node* root_or_safepoint = root_and_safepoints->at(i);
4327       // If the node is a safepoint, let's check if it still has a control input
4328       // Lack of control input signifies that this node was killed by CCP or
4329       // recursively by remove_globally_dead_node and it shouldn't be a starting
4330       // point.
4331       if (!root_or_safepoint->is_SafePoint() || root_or_safepoint->in(0) != nullptr) {
4332         nstack.push(root_or_safepoint);
4333       }
4334     }
4335   } else {
4336     nstack.push(_root);
4337   }
4338 
4339   while (nstack.size() > 0) {
4340     Node* n = nstack.pop();
4341     if (visited.member(n)) {
4342       continue;
4343     }
4344     visited.push(n);
4345 
4346     // Walk over all input edges, checking for correspondence
4347     uint length = n->len();
4348     for (uint i = 0; i < length; i++) {
4349       Node* in = n->in(i);
4350       if (in != nullptr && !visited.member(in)) {
4351         nstack.push(in); // Put it on stack
4352       }
4353       if (in != nullptr && !in->is_top()) {
4354         // Count instances of `next`
4355         int cnt = 0;
4356         for (uint idx = 0; idx < in->_outcnt; idx++) {
4357           if (in->_out[idx] == n) {
4358             cnt++;
4359           }
4360         }
4361         assert(cnt > 0, "Failed to find Def-Use edge.");
4362         // Check for duplicate edges
4363         // walk the input array downcounting the input edges to n
4364         for (uint j = 0; j < length; j++) {
4365           if (n->in(j) == in) {
4366             cnt--;
4367           }
4368         }
4369         assert(cnt == 0, "Mismatched edge count.");
4370       } else if (in == nullptr) {
4371         assert(i == 0 || i >= n->req() ||
4372                n->is_Region() || n->is_Phi() || n->is_ArrayCopy() ||
4373                (n->is_Unlock() && i == (n->req() - 1)) ||
4374                (n->is_MemBar() && i == 5), // the precedence edge to a membar can be removed during macro node expansion
4375               "only region, phi, arraycopy, unlock or membar nodes have null data edges");
4376       } else {
4377         assert(in->is_top(), "sanity");
4378         // Nothing to check.
4379       }
4380     }
4381   }
4382 }
4383 
4384 //------------------------------verify_graph_edges---------------------------
4385 // Walk the Graph and verify that there is a one-to-one correspondence
4386 // between Use-Def edges and Def-Use edges in the graph.
4387 void Compile::verify_graph_edges(bool no_dead_code, const Unique_Node_List* root_and_safepoints) const {
4388   if (VerifyGraphEdges) {
4389     Unique_Node_List visited;
4390 
4391     // Call graph walk to check edges
4392     verify_bidirectional_edges(visited, root_and_safepoints);
4393     if (no_dead_code) {
4394       // Now make sure that no visited node is used by an unvisited node.
4395       bool dead_nodes = false;
4396       Unique_Node_List checked;
4397       while (visited.size() > 0) {
4398         Node* n = visited.pop();
4399         checked.push(n);
4400         for (uint i = 0; i < n->outcnt(); i++) {
4401           Node* use = n->raw_out(i);
4402           if (checked.member(use))  continue;  // already checked
4403           if (visited.member(use))  continue;  // already in the graph
4404           if (use->is_Con())        continue;  // a dead ConNode is OK
4405           // At this point, we have found a dead node which is DU-reachable.
4406           if (!dead_nodes) {
4407             tty->print_cr("*** Dead nodes reachable via DU edges:");
4408             dead_nodes = true;
4409           }
4410           use->dump(2);
4411           tty->print_cr("---");
4412           checked.push(use);  // No repeats; pretend it is now checked.
4413         }
4414       }
4415       assert(!dead_nodes, "using nodes must be reachable from root");
4416     }
4417   }
4418 }
4419 #endif
4420 
4421 // The Compile object keeps track of failure reasons separately from the ciEnv.
4422 // This is required because there is not quite a 1-1 relation between the
4423 // ciEnv and its compilation task and the Compile object.  Note that one
4424 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
4425 // to backtrack and retry without subsuming loads.  Other than this backtracking
4426 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
4427 // by the logic in C2Compiler.
4428 void Compile::record_failure(const char* reason DEBUG_ONLY(COMMA bool allow_multiple_failures)) {
4429   if (log() != nullptr) {
4430     log()->elem("failure reason='%s' phase='compile'", reason);
4431   }
4432   if (_failure_reason.get() == nullptr) {
4433     // Record the first failure reason.
4434     _failure_reason.set(reason);
4435     if (CaptureBailoutInformation) {
4436       _first_failure_details = new CompilationFailureInfo(reason);
4437     }
4438   } else {
4439     assert(!StressBailout || allow_multiple_failures, "should have handled previous failure.");
4440   }
4441 
4442   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
4443     C->print_method(PHASE_FAILURE, 1);
4444   }
4445   _root = nullptr;  // flush the graph, too
4446 }
4447 
4448 Compile::TracePhase::TracePhase(const char* name, PhaseTraceId id)
4449   : TraceTime(name, &Phase::timers[id], CITime, CITimeVerbose),
4450     _compile(Compile::current()),
4451     _log(nullptr),
4452     _dolog(CITimeVerbose)
4453 {
4454   assert(_compile != nullptr, "sanity check");
4455   assert(id != PhaseTraceId::_t_none, "Don't use none");
4456   if (_dolog) {
4457     _log = _compile->log();
4458   }
4459   if (_log != nullptr) {
4460     _log->begin_head("phase name='%s' nodes='%d' live='%d'", phase_name(), _compile->unique(), _compile->live_nodes());
4461     _log->stamp();
4462     _log->end_head();
4463   }
4464 
4465   // Inform memory statistic, if enabled
4466   if (CompilationMemoryStatistic::enabled()) {
4467     CompilationMemoryStatistic::on_phase_start((int)id, name);
4468   }
4469 }
4470 
4471 Compile::TracePhase::TracePhase(PhaseTraceId id)
4472   : TracePhase(Phase::get_phase_trace_id_text(id), id) {}
4473 
4474 Compile::TracePhase::~TracePhase() {
4475 
4476   // Inform memory statistic, if enabled
4477   if (CompilationMemoryStatistic::enabled()) {
4478     CompilationMemoryStatistic::on_phase_end();
4479   }
4480 
4481   if (_compile->failing_internal()) {
4482     if (_log != nullptr) {
4483       _log->done("phase");
4484     }
4485     return; // timing code, not stressing bailouts.
4486   }
4487 #ifdef ASSERT
4488   if (PrintIdealNodeCount) {
4489     tty->print_cr("phase name='%s' nodes='%d' live='%d' live_graph_walk='%d'",
4490                   phase_name(), _compile->unique(), _compile->live_nodes(), _compile->count_live_nodes_by_graph_walk());
4491   }
4492 
4493   if (VerifyIdealNodeCount) {
4494     _compile->print_missing_nodes();
4495   }
4496 #endif
4497 
4498   if (_log != nullptr) {
4499     _log->done("phase name='%s' nodes='%d' live='%d'", phase_name(), _compile->unique(), _compile->live_nodes());
4500   }
4501 }
4502 
4503 //----------------------------static_subtype_check-----------------------------
4504 // Shortcut important common cases when superklass is exact:
4505 // (0) superklass is java.lang.Object (can occur in reflective code)
4506 // (1) subklass is already limited to a subtype of superklass => always ok
4507 // (2) subklass does not overlap with superklass => always fail
4508 // (3) superklass has NO subtypes and we can check with a simple compare.
4509 Compile::SubTypeCheckResult Compile::static_subtype_check(const TypeKlassPtr* superk, const TypeKlassPtr* subk, bool skip) {
4510   if (skip) {
4511     return SSC_full_test;       // Let caller generate the general case.
4512   }
4513 
4514   if (subk->is_java_subtype_of(superk)) {
4515     return SSC_always_true; // (0) and (1)  this test cannot fail
4516   }
4517 
4518   if (!subk->maybe_java_subtype_of(superk)) {
4519     return SSC_always_false; // (2) true path dead; no dynamic test needed
4520   }
4521 
4522   const Type* superelem = superk;
4523   if (superk->isa_aryklassptr()) {
4524     int ignored;
4525     superelem = superk->is_aryklassptr()->base_element_type(ignored);
4526   }
4527 
4528   if (superelem->isa_instklassptr()) {
4529     ciInstanceKlass* ik = superelem->is_instklassptr()->instance_klass();
4530     if (!ik->has_subklass()) {
4531       if (!ik->is_final()) {
4532         // Add a dependency if there is a chance of a later subclass.
4533         dependencies()->assert_leaf_type(ik);
4534       }
4535       if (!superk->maybe_java_subtype_of(subk)) {
4536         return SSC_always_false;
4537       }
4538       return SSC_easy_test;     // (3) caller can do a simple ptr comparison
4539     }
4540   } else {
4541     // A primitive array type has no subtypes.
4542     return SSC_easy_test;       // (3) caller can do a simple ptr comparison
4543   }
4544 
4545   return SSC_full_test;
4546 }
4547 
4548 Node* Compile::conv_I2X_index(PhaseGVN* phase, Node* idx, const TypeInt* sizetype, Node* ctrl) {
4549 #ifdef _LP64
4550   // The scaled index operand to AddP must be a clean 64-bit value.
4551   // Java allows a 32-bit int to be incremented to a negative
4552   // value, which appears in a 64-bit register as a large
4553   // positive number.  Using that large positive number as an
4554   // operand in pointer arithmetic has bad consequences.
4555   // On the other hand, 32-bit overflow is rare, and the possibility
4556   // can often be excluded, if we annotate the ConvI2L node with
4557   // a type assertion that its value is known to be a small positive
4558   // number.  (The prior range check has ensured this.)
4559   // This assertion is used by ConvI2LNode::Ideal.
4560   int index_max = max_jint - 1;  // array size is max_jint, index is one less
4561   if (sizetype != nullptr && sizetype->_hi > 0) {
4562     index_max = sizetype->_hi - 1;
4563   }
4564   const TypeInt* iidxtype = TypeInt::make(0, index_max, Type::WidenMax);
4565   idx = constrained_convI2L(phase, idx, iidxtype, ctrl);
4566 #endif
4567   return idx;
4568 }
4569 
4570 // Convert integer value to a narrowed long type dependent on ctrl (for example, a range check)
4571 Node* Compile::constrained_convI2L(PhaseGVN* phase, Node* value, const TypeInt* itype, Node* ctrl, bool carry_dependency) {
4572   if (ctrl != nullptr) {
4573     // Express control dependency by a CastII node with a narrow type.
4574     // Make the CastII node dependent on the control input to prevent the narrowed ConvI2L
4575     // node from floating above the range check during loop optimizations. Otherwise, the
4576     // ConvI2L node may be eliminated independently of the range check, causing the data path
4577     // to become TOP while the control path is still there (although it's unreachable).
4578     value = new CastIINode(ctrl, value, itype, carry_dependency ? ConstraintCastNode::DependencyType::NonFloatingNarrowing : ConstraintCastNode::DependencyType::FloatingNarrowing, true /* range check dependency */);
4579     value = phase->transform(value);
4580   }
4581   const TypeLong* ltype = TypeLong::make(itype->_lo, itype->_hi, itype->_widen);
4582   return phase->transform(new ConvI2LNode(value, ltype));
4583 }
4584 
4585 void Compile::dump_print_inlining() {
4586   inline_printer()->print_on(tty);
4587 }
4588 
4589 void Compile::log_late_inline(CallGenerator* cg) {
4590   if (log() != nullptr) {
4591     log()->head("late_inline method='%d' inline_id='" JLONG_FORMAT "'", log()->identify(cg->method()),
4592                 cg->unique_id());
4593     JVMState* p = cg->call_node()->jvms();
4594     while (p != nullptr) {
4595       log()->elem("jvms bci='%d' method='%d'", p->bci(), log()->identify(p->method()));
4596       p = p->caller();
4597     }
4598     log()->tail("late_inline");
4599   }
4600 }
4601 
4602 void Compile::log_late_inline_failure(CallGenerator* cg, const char* msg) {
4603   log_late_inline(cg);
4604   if (log() != nullptr) {
4605     log()->inline_fail(msg);
4606   }
4607 }
4608 
4609 void Compile::log_inline_id(CallGenerator* cg) {
4610   if (log() != nullptr) {
4611     // The LogCompilation tool needs a unique way to identify late
4612     // inline call sites. This id must be unique for this call site in
4613     // this compilation. Try to have it unique across compilations as
4614     // well because it can be convenient when grepping through the log
4615     // file.
4616     // Distinguish OSR compilations from others in case CICountOSR is
4617     // on.
4618     jlong id = ((jlong)unique()) + (((jlong)compile_id()) << 33) + (CICountOSR && is_osr_compilation() ? ((jlong)1) << 32 : 0);
4619     cg->set_unique_id(id);
4620     log()->elem("inline_id id='" JLONG_FORMAT "'", id);
4621   }
4622 }
4623 
4624 void Compile::log_inline_failure(const char* msg) {
4625   if (C->log() != nullptr) {
4626     C->log()->inline_fail(msg);
4627   }
4628 }
4629 
4630 
4631 // Dump inlining replay data to the stream.
4632 // Don't change thread state and acquire any locks.
4633 void Compile::dump_inline_data(outputStream* out) {
4634   InlineTree* inl_tree = ilt();
4635   if (inl_tree != nullptr) {
4636     out->print(" inline %d", inl_tree->count());
4637     inl_tree->dump_replay_data(out);
4638   }
4639 }
4640 
4641 void Compile::dump_inline_data_reduced(outputStream* out) {
4642   assert(ReplayReduce, "");
4643 
4644   InlineTree* inl_tree = ilt();
4645   if (inl_tree == nullptr) {
4646     return;
4647   }
4648   // Enable iterative replay file reduction
4649   // Output "compile" lines for depth 1 subtrees,
4650   // simulating that those trees were compiled
4651   // instead of inlined.
4652   for (int i = 0; i < inl_tree->subtrees().length(); ++i) {
4653     InlineTree* sub = inl_tree->subtrees().at(i);
4654     if (sub->inline_level() != 1) {
4655       continue;
4656     }
4657 
4658     ciMethod* method = sub->method();
4659     int entry_bci = -1;
4660     int comp_level = env()->task()->comp_level();
4661     out->print("compile ");
4662     method->dump_name_as_ascii(out);
4663     out->print(" %d %d", entry_bci, comp_level);
4664     out->print(" inline %d", sub->count());
4665     sub->dump_replay_data(out, -1);
4666     out->cr();
4667   }
4668 }
4669 
4670 int Compile::cmp_expensive_nodes(Node* n1, Node* n2) {
4671   if (n1->Opcode() < n2->Opcode())      return -1;
4672   else if (n1->Opcode() > n2->Opcode()) return 1;
4673 
4674   assert(n1->req() == n2->req(), "can't compare %s nodes: n1->req() = %d, n2->req() = %d", NodeClassNames[n1->Opcode()], n1->req(), n2->req());
4675   for (uint i = 1; i < n1->req(); i++) {
4676     if (n1->in(i) < n2->in(i))      return -1;
4677     else if (n1->in(i) > n2->in(i)) return 1;
4678   }
4679 
4680   return 0;
4681 }
4682 
4683 int Compile::cmp_expensive_nodes(Node** n1p, Node** n2p) {
4684   Node* n1 = *n1p;
4685   Node* n2 = *n2p;
4686 
4687   return cmp_expensive_nodes(n1, n2);
4688 }
4689 
4690 void Compile::sort_expensive_nodes() {
4691   if (!expensive_nodes_sorted()) {
4692     _expensive_nodes.sort(cmp_expensive_nodes);
4693   }
4694 }
4695 
4696 bool Compile::expensive_nodes_sorted() const {
4697   for (int i = 1; i < _expensive_nodes.length(); i++) {
4698     if (cmp_expensive_nodes(_expensive_nodes.adr_at(i), _expensive_nodes.adr_at(i-1)) < 0) {
4699       return false;
4700     }
4701   }
4702   return true;
4703 }
4704 
4705 bool Compile::should_optimize_expensive_nodes(PhaseIterGVN &igvn) {
4706   if (_expensive_nodes.length() == 0) {
4707     return false;
4708   }
4709 
4710   assert(OptimizeExpensiveOps, "optimization off?");
4711 
4712   // Take this opportunity to remove dead nodes from the list
4713   int j = 0;
4714   for (int i = 0; i < _expensive_nodes.length(); i++) {
4715     Node* n = _expensive_nodes.at(i);
4716     if (!n->is_unreachable(igvn)) {
4717       assert(n->is_expensive(), "should be expensive");
4718       _expensive_nodes.at_put(j, n);
4719       j++;
4720     }
4721   }
4722   _expensive_nodes.trunc_to(j);
4723 
4724   // Then sort the list so that similar nodes are next to each other
4725   // and check for at least two nodes of identical kind with same data
4726   // inputs.
4727   sort_expensive_nodes();
4728 
4729   for (int i = 0; i < _expensive_nodes.length()-1; i++) {
4730     if (cmp_expensive_nodes(_expensive_nodes.adr_at(i), _expensive_nodes.adr_at(i+1)) == 0) {
4731       return true;
4732     }
4733   }
4734 
4735   return false;
4736 }
4737 
4738 void Compile::cleanup_expensive_nodes(PhaseIterGVN &igvn) {
4739   if (_expensive_nodes.length() == 0) {
4740     return;
4741   }
4742 
4743   assert(OptimizeExpensiveOps, "optimization off?");
4744 
4745   // Sort to bring similar nodes next to each other and clear the
4746   // control input of nodes for which there's only a single copy.
4747   sort_expensive_nodes();
4748 
4749   int j = 0;
4750   int identical = 0;
4751   int i = 0;
4752   bool modified = false;
4753   for (; i < _expensive_nodes.length()-1; i++) {
4754     assert(j <= i, "can't write beyond current index");
4755     if (_expensive_nodes.at(i)->Opcode() == _expensive_nodes.at(i+1)->Opcode()) {
4756       identical++;
4757       _expensive_nodes.at_put(j++, _expensive_nodes.at(i));
4758       continue;
4759     }
4760     if (identical > 0) {
4761       _expensive_nodes.at_put(j++, _expensive_nodes.at(i));
4762       identical = 0;
4763     } else {
4764       Node* n = _expensive_nodes.at(i);
4765       igvn.replace_input_of(n, 0, nullptr);
4766       igvn.hash_insert(n);
4767       modified = true;
4768     }
4769   }
4770   if (identical > 0) {
4771     _expensive_nodes.at_put(j++, _expensive_nodes.at(i));
4772   } else if (_expensive_nodes.length() >= 1) {
4773     Node* n = _expensive_nodes.at(i);
4774     igvn.replace_input_of(n, 0, nullptr);
4775     igvn.hash_insert(n);
4776     modified = true;
4777   }
4778   _expensive_nodes.trunc_to(j);
4779   if (modified) {
4780     igvn.optimize();
4781   }
4782 }
4783 
4784 void Compile::add_expensive_node(Node * n) {
4785   assert(!_expensive_nodes.contains(n), "duplicate entry in expensive list");
4786   assert(n->is_expensive(), "expensive nodes with non-null control here only");
4787   assert(!n->is_CFG() && !n->is_Mem(), "no cfg or memory nodes here");
4788   if (OptimizeExpensiveOps) {
4789     _expensive_nodes.append(n);
4790   } else {
4791     // Clear control input and let IGVN optimize expensive nodes if
4792     // OptimizeExpensiveOps is off.
4793     n->set_req(0, nullptr);
4794   }
4795 }
4796 
4797 /**
4798  * Track coarsened Lock and Unlock nodes.
4799  */
4800 
4801 class Lock_List : public Node_List {
4802   uint _origin_cnt;
4803 public:
4804   Lock_List(Arena *a, uint cnt) : Node_List(a), _origin_cnt(cnt) {}
4805   uint origin_cnt() const { return _origin_cnt; }
4806 };
4807 
4808 void Compile::add_coarsened_locks(GrowableArray<AbstractLockNode*>& locks) {
4809   int length = locks.length();
4810   if (length > 0) {
4811     // Have to keep this list until locks elimination during Macro nodes elimination.
4812     Lock_List* locks_list = new (comp_arena()) Lock_List(comp_arena(), length);
4813     AbstractLockNode* alock = locks.at(0);
4814     BoxLockNode* box = alock->box_node()->as_BoxLock();
4815     for (int i = 0; i < length; i++) {
4816       AbstractLockNode* lock = locks.at(i);
4817       assert(lock->is_coarsened(), "expecting only coarsened AbstractLock nodes, but got '%s'[%d] node", lock->Name(), lock->_idx);
4818       locks_list->push(lock);
4819       BoxLockNode* this_box = lock->box_node()->as_BoxLock();
4820       if (this_box != box) {
4821         // Locking regions (BoxLock) could be Unbalanced here:
4822         //  - its coarsened locks were eliminated in earlier
4823         //    macro nodes elimination followed by loop unroll
4824         //  - it is OSR locking region (no Lock node)
4825         // Preserve Unbalanced status in such cases.
4826         if (!this_box->is_unbalanced()) {
4827           this_box->set_coarsened();
4828         }
4829         if (!box->is_unbalanced()) {
4830           box->set_coarsened();
4831         }
4832       }
4833     }
4834     _coarsened_locks.append(locks_list);
4835   }
4836 }
4837 
4838 void Compile::remove_useless_coarsened_locks(Unique_Node_List& useful) {
4839   int count = coarsened_count();
4840   for (int i = 0; i < count; i++) {
4841     Node_List* locks_list = _coarsened_locks.at(i);
4842     for (uint j = 0; j < locks_list->size(); j++) {
4843       Node* lock = locks_list->at(j);
4844       assert(lock->is_AbstractLock(), "sanity");
4845       if (!useful.member(lock)) {
4846         locks_list->yank(lock);
4847       }
4848     }
4849   }
4850 }
4851 
4852 void Compile::remove_coarsened_lock(Node* n) {
4853   if (n->is_AbstractLock()) {
4854     int count = coarsened_count();
4855     for (int i = 0; i < count; i++) {
4856       Node_List* locks_list = _coarsened_locks.at(i);
4857       locks_list->yank(n);
4858     }
4859   }
4860 }
4861 
4862 bool Compile::coarsened_locks_consistent() {
4863   int count = coarsened_count();
4864   for (int i = 0; i < count; i++) {
4865     bool unbalanced = false;
4866     bool modified = false; // track locks kind modifications
4867     Lock_List* locks_list = (Lock_List*)_coarsened_locks.at(i);
4868     uint size = locks_list->size();
4869     if (size == 0) {
4870       unbalanced = false; // All locks were eliminated - good
4871     } else if (size != locks_list->origin_cnt()) {
4872       unbalanced = true; // Some locks were removed from list
4873     } else {
4874       for (uint j = 0; j < size; j++) {
4875         Node* lock = locks_list->at(j);
4876         // All nodes in group should have the same state (modified or not)
4877         if (!lock->as_AbstractLock()->is_coarsened()) {
4878           if (j == 0) {
4879             // first on list was modified, the rest should be too for consistency
4880             modified = true;
4881           } else if (!modified) {
4882             // this lock was modified but previous locks on the list were not
4883             unbalanced = true;
4884             break;
4885           }
4886         } else if (modified) {
4887           // previous locks on list were modified but not this lock
4888           unbalanced = true;
4889           break;
4890         }
4891       }
4892     }
4893     if (unbalanced) {
4894       // unbalanced monitor enter/exit - only some [un]lock nodes were removed or modified
4895 #ifdef ASSERT
4896       if (PrintEliminateLocks) {
4897         tty->print_cr("=== unbalanced coarsened locks ===");
4898         for (uint l = 0; l < size; l++) {
4899           locks_list->at(l)->dump();
4900         }
4901       }
4902 #endif
4903       record_failure(C2Compiler::retry_no_locks_coarsening());
4904       return false;
4905     }
4906   }
4907   return true;
4908 }
4909 
4910 // Mark locking regions (identified by BoxLockNode) as unbalanced if
4911 // locks coarsening optimization removed Lock/Unlock nodes from them.
4912 // Such regions become unbalanced because coarsening only removes part
4913 // of Lock/Unlock nodes in region. As result we can't execute other
4914 // locks elimination optimizations which assume all code paths have
4915 // corresponding pair of Lock/Unlock nodes - they are balanced.
4916 void Compile::mark_unbalanced_boxes() const {
4917   int count = coarsened_count();
4918   for (int i = 0; i < count; i++) {
4919     Node_List* locks_list = _coarsened_locks.at(i);
4920     uint size = locks_list->size();
4921     if (size > 0) {
4922       AbstractLockNode* alock = locks_list->at(0)->as_AbstractLock();
4923       BoxLockNode* box = alock->box_node()->as_BoxLock();
4924       if (alock->is_coarsened()) {
4925         // coarsened_locks_consistent(), which is called before this method, verifies
4926         // that the rest of Lock/Unlock nodes on locks_list are also coarsened.
4927         assert(!box->is_eliminated(), "regions with coarsened locks should not be marked as eliminated");
4928         for (uint j = 1; j < size; j++) {
4929           assert(locks_list->at(j)->as_AbstractLock()->is_coarsened(), "only coarsened locks are expected here");
4930           BoxLockNode* this_box = locks_list->at(j)->as_AbstractLock()->box_node()->as_BoxLock();
4931           if (box != this_box) {
4932             assert(!this_box->is_eliminated(), "regions with coarsened locks should not be marked as eliminated");
4933             box->set_unbalanced();
4934             this_box->set_unbalanced();
4935           }
4936         }
4937       }
4938     }
4939   }
4940 }
4941 
4942 /**
4943  * Remove the speculative part of types and clean up the graph
4944  */
4945 void Compile::remove_speculative_types(PhaseIterGVN &igvn) {
4946   if (UseTypeSpeculation) {
4947     Unique_Node_List worklist;
4948     worklist.push(root());
4949     int modified = 0;
4950     // Go over all type nodes that carry a speculative type, drop the
4951     // speculative part of the type and enqueue the node for an igvn
4952     // which may optimize it out.
4953     for (uint next = 0; next < worklist.size(); ++next) {
4954       Node *n  = worklist.at(next);
4955       if (n->is_Type()) {
4956         TypeNode* tn = n->as_Type();
4957         const Type* t = tn->type();
4958         const Type* t_no_spec = t->remove_speculative();
4959         if (t_no_spec != t) {
4960           bool in_hash = igvn.hash_delete(n);
4961           assert(in_hash || n->hash() == Node::NO_HASH, "node should be in igvn hash table");
4962           tn->set_type(t_no_spec);
4963           igvn.hash_insert(n);
4964           igvn._worklist.push(n); // give it a chance to go away
4965           modified++;
4966         }
4967       }
4968       // Iterate over outs - endless loops is unreachable from below
4969       for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
4970         Node *m = n->fast_out(i);
4971         if (not_a_node(m)) {
4972           continue;
4973         }
4974         worklist.push(m);
4975       }
4976     }
4977     // Drop the speculative part of all types in the igvn's type table
4978     igvn.remove_speculative_types();
4979     if (modified > 0) {
4980       igvn.optimize();
4981       if (failing())  return;
4982     }
4983 #ifdef ASSERT
4984     // Verify that after the IGVN is over no speculative type has resurfaced
4985     worklist.clear();
4986     worklist.push(root());
4987     for (uint next = 0; next < worklist.size(); ++next) {
4988       Node *n  = worklist.at(next);
4989       const Type* t = igvn.type_or_null(n);
4990       assert((t == nullptr) || (t == t->remove_speculative()), "no more speculative types");
4991       if (n->is_Type()) {
4992         t = n->as_Type()->type();
4993         assert(t == t->remove_speculative(), "no more speculative types");
4994       }
4995       // Iterate over outs - endless loops is unreachable from below
4996       for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
4997         Node *m = n->fast_out(i);
4998         if (not_a_node(m)) {
4999           continue;
5000         }
5001         worklist.push(m);
5002       }
5003     }
5004     igvn.check_no_speculative_types();
5005 #endif
5006   }
5007 }
5008 
5009 // Auxiliary methods to support randomized stressing/fuzzing.
5010 
5011 void Compile::initialize_stress_seed(const DirectiveSet* directive) {
5012   if (FLAG_IS_DEFAULT(StressSeed) || (FLAG_IS_ERGO(StressSeed) && directive->RepeatCompilationOption)) {
5013     _stress_seed = static_cast<uint>(Ticks::now().nanoseconds());
5014     FLAG_SET_ERGO(StressSeed, _stress_seed);
5015   } else {
5016     _stress_seed = StressSeed;
5017   }
5018   if (_log != nullptr) {
5019     _log->elem("stress_test seed='%u'", _stress_seed);
5020   }
5021 }
5022 
5023 int Compile::random() {
5024   _stress_seed = os::next_random(_stress_seed);
5025   return static_cast<int>(_stress_seed);
5026 }
5027 
5028 // This method can be called the arbitrary number of times, with current count
5029 // as the argument. The logic allows selecting a single candidate from the
5030 // running list of candidates as follows:
5031 //    int count = 0;
5032 //    Cand* selected = null;
5033 //    while(cand = cand->next()) {
5034 //      if (randomized_select(++count)) {
5035 //        selected = cand;
5036 //      }
5037 //    }
5038 //
5039 // Including count equalizes the chances any candidate is "selected".
5040 // This is useful when we don't have the complete list of candidates to choose
5041 // from uniformly. In this case, we need to adjust the randomicity of the
5042 // selection, or else we will end up biasing the selection towards the latter
5043 // candidates.
5044 //
5045 // Quick back-envelope calculation shows that for the list of n candidates
5046 // the equal probability for the candidate to persist as "best" can be
5047 // achieved by replacing it with "next" k-th candidate with the probability
5048 // of 1/k. It can be easily shown that by the end of the run, the
5049 // probability for any candidate is converged to 1/n, thus giving the
5050 // uniform distribution among all the candidates.
5051 //
5052 // We don't care about the domain size as long as (RANDOMIZED_DOMAIN / count) is large.
5053 #define RANDOMIZED_DOMAIN_POW 29
5054 #define RANDOMIZED_DOMAIN (1 << RANDOMIZED_DOMAIN_POW)
5055 #define RANDOMIZED_DOMAIN_MASK ((1 << (RANDOMIZED_DOMAIN_POW + 1)) - 1)
5056 bool Compile::randomized_select(int count) {
5057   assert(count > 0, "only positive");
5058   return (random() & RANDOMIZED_DOMAIN_MASK) < (RANDOMIZED_DOMAIN / count);
5059 }
5060 
5061 #ifdef ASSERT
5062 // Failures are geometrically distributed with probability 1/StressBailoutMean.
5063 bool Compile::fail_randomly() {
5064   if ((random() % StressBailoutMean) != 0) {
5065     return false;
5066   }
5067   record_failure("StressBailout");
5068   return true;
5069 }
5070 
5071 bool Compile::failure_is_artificial() {
5072   return C->failure_reason_is("StressBailout");
5073 }
5074 #endif
5075 
5076 CloneMap&     Compile::clone_map()                 { return _clone_map; }
5077 void          Compile::set_clone_map(Dict* d)      { _clone_map._dict = d; }
5078 
5079 void NodeCloneInfo::dump_on(outputStream* st) const {
5080   st->print(" {%d:%d} ", idx(), gen());
5081 }
5082 
5083 void CloneMap::clone(Node* old, Node* nnn, int gen) {
5084   uint64_t val = value(old->_idx);
5085   NodeCloneInfo cio(val);
5086   assert(val != 0, "old node should be in the map");
5087   NodeCloneInfo cin(cio.idx(), gen + cio.gen());
5088   insert(nnn->_idx, cin.get());
5089 #ifndef PRODUCT
5090   if (is_debug()) {
5091     tty->print_cr("CloneMap::clone inserted node %d info {%d:%d} into CloneMap", nnn->_idx, cin.idx(), cin.gen());
5092   }
5093 #endif
5094 }
5095 
5096 void CloneMap::verify_insert_and_clone(Node* old, Node* nnn, int gen) {
5097   NodeCloneInfo cio(value(old->_idx));
5098   if (cio.get() == 0) {
5099     cio.set(old->_idx, 0);
5100     insert(old->_idx, cio.get());
5101 #ifndef PRODUCT
5102     if (is_debug()) {
5103       tty->print_cr("CloneMap::verify_insert_and_clone inserted node %d info {%d:%d} into CloneMap", old->_idx, cio.idx(), cio.gen());
5104     }
5105 #endif
5106   }
5107   clone(old, nnn, gen);
5108 }
5109 
5110 int CloneMap::max_gen() const {
5111   int g = 0;
5112   DictI di(_dict);
5113   for(; di.test(); ++di) {
5114     int t = gen(di._key);
5115     if (g < t) {
5116       g = t;
5117 #ifndef PRODUCT
5118       if (is_debug()) {
5119         tty->print_cr("CloneMap::max_gen() update max=%d from %d", g, _2_node_idx_t(di._key));
5120       }
5121 #endif
5122     }
5123   }
5124   return g;
5125 }
5126 
5127 void CloneMap::dump(node_idx_t key, outputStream* st) const {
5128   uint64_t val = value(key);
5129   if (val != 0) {
5130     NodeCloneInfo ni(val);
5131     ni.dump_on(st);
5132   }
5133 }
5134 
5135 void Compile::shuffle_macro_nodes() {
5136   shuffle_array(*C, _macro_nodes);
5137 }
5138 
5139 // Move Allocate nodes to the start of the list
5140 void Compile::sort_macro_nodes() {
5141   int count = macro_count();
5142   int allocates = 0;
5143   for (int i = 0; i < count; i++) {
5144     Node* n = macro_node(i);
5145     if (n->is_Allocate()) {
5146       if (i != allocates) {
5147         Node* tmp = macro_node(allocates);
5148         _macro_nodes.at_put(allocates, n);
5149         _macro_nodes.at_put(i, tmp);
5150       }
5151       allocates++;
5152     }
5153   }
5154 }
5155 
5156 void Compile::print_method(CompilerPhaseType compile_phase, int level, Node* n) {
5157   if (failing_internal()) { return; } // failing_internal to not stress bailouts from printing code.
5158   EventCompilerPhase event(UNTIMED);
5159   if (event.should_commit()) {
5160     CompilerEvent::PhaseEvent::post(event, C->_latest_stage_start_counter, compile_phase, C->_compile_id, level);
5161   }
5162 #ifndef PRODUCT
5163   ResourceMark rm;
5164   stringStream ss;
5165   ss.print_raw(CompilerPhaseTypeHelper::to_description(compile_phase));
5166   int iter = ++_igv_phase_iter[compile_phase];
5167   if (iter > 1) {
5168     ss.print(" %d", iter);
5169   }
5170   if (n != nullptr) {
5171     ss.print(": %d %s", n->_idx, NodeClassNames[n->Opcode()]);
5172     if (n->is_Call()) {
5173       CallNode* call = n->as_Call();
5174       if (call->_name != nullptr) {
5175         // E.g. uncommon traps etc.
5176         ss.print(" - %s", call->_name);
5177       } else if (call->is_CallJava()) {
5178         CallJavaNode* call_java = call->as_CallJava();
5179         if (call_java->method() != nullptr) {
5180           ss.print(" -");
5181           call_java->method()->print_short_name(&ss);
5182         }
5183       }
5184     }
5185   }
5186 
5187   const char* name = ss.as_string();
5188   if (should_print_igv(level)) {
5189     _igv_printer->print_graph(name);
5190   }
5191   if (should_print_phase(level)) {
5192     print_phase(name);
5193   }
5194   if (should_print_ideal_phase(compile_phase)) {
5195     print_ideal_ir(CompilerPhaseTypeHelper::to_name(compile_phase));
5196   }
5197 #endif
5198   C->_latest_stage_start_counter.stamp();
5199 }
5200 
5201 // Only used from CompileWrapper
5202 void Compile::begin_method() {
5203 #ifndef PRODUCT
5204   if (_method != nullptr && should_print_igv(1)) {
5205     _igv_printer->begin_method();
5206   }
5207 #endif
5208   C->_latest_stage_start_counter.stamp();
5209 }
5210 
5211 // Only used from CompileWrapper
5212 void Compile::end_method() {
5213   EventCompilerPhase event(UNTIMED);
5214   if (event.should_commit()) {
5215     CompilerEvent::PhaseEvent::post(event, C->_latest_stage_start_counter, PHASE_END, C->_compile_id, 1);
5216   }
5217 
5218 #ifndef PRODUCT
5219   if (_method != nullptr && should_print_igv(1)) {
5220     _igv_printer->end_method();
5221   }
5222 #endif
5223 }
5224 
5225 #ifndef PRODUCT
5226 bool Compile::should_print_phase(const int level) const {
5227   return PrintPhaseLevel >= 0 && directive()->PhasePrintLevelOption >= level &&
5228          _method != nullptr; // Do not print phases for stubs.
5229 }
5230 
5231 bool Compile::should_print_ideal_phase(CompilerPhaseType cpt) const {
5232   return _directive->should_print_ideal_phase(cpt);
5233 }
5234 
5235 void Compile::init_igv() {
5236   if (_igv_printer == nullptr) {
5237     _igv_printer = IdealGraphPrinter::printer();
5238     _igv_printer->set_compile(this);
5239   }
5240 }
5241 
5242 bool Compile::should_print_igv(const int level) {
5243   PRODUCT_RETURN_(return false;);
5244 
5245   if (PrintIdealGraphLevel < 0) { // disabled by the user
5246     return false;
5247   }
5248 
5249   bool need = directive()->IGVPrintLevelOption >= level;
5250   if (need) {
5251     Compile::init_igv();
5252   }
5253   return need;
5254 }
5255 
5256 IdealGraphPrinter* Compile::_debug_file_printer = nullptr;
5257 IdealGraphPrinter* Compile::_debug_network_printer = nullptr;
5258 
5259 // Called from debugger. Prints method to the default file with the default phase name.
5260 // This works regardless of any Ideal Graph Visualizer flags set or not.
5261 // Use in debugger (gdb/rr): p igv_print($sp, $fp, $pc).
5262 void igv_print(void* sp, void* fp, void* pc) {
5263   frame fr(sp, fp, pc);
5264   Compile::current()->igv_print_method_to_file(nullptr, false, &fr);
5265 }
5266 
5267 // Same as igv_print() above but with a specified phase name.
5268 void igv_print(const char* phase_name, void* sp, void* fp, void* pc) {
5269   frame fr(sp, fp, pc);
5270   Compile::current()->igv_print_method_to_file(phase_name, false, &fr);
5271 }
5272 
5273 // Called from debugger. Prints method with the default phase name to the default network or the one specified with
5274 // the network flags for the Ideal Graph Visualizer, or to the default file depending on the 'network' argument.
5275 // This works regardless of any Ideal Graph Visualizer flags set or not.
5276 // Use in debugger (gdb/rr): p igv_print(true, $sp, $fp, $pc).
5277 void igv_print(bool network, void* sp, void* fp, void* pc) {
5278   frame fr(sp, fp, pc);
5279   if (network) {
5280     Compile::current()->igv_print_method_to_network(nullptr, &fr);
5281   } else {
5282     Compile::current()->igv_print_method_to_file(nullptr, false, &fr);
5283   }
5284 }
5285 
5286 // Same as igv_print(bool network, ...) above but with a specified phase name.
5287 // Use in debugger (gdb/rr): p igv_print(true, "MyPhase", $sp, $fp, $pc).
5288 void igv_print(bool network, const char* phase_name, void* sp, void* fp, void* pc) {
5289   frame fr(sp, fp, pc);
5290   if (network) {
5291     Compile::current()->igv_print_method_to_network(phase_name, &fr);
5292   } else {
5293     Compile::current()->igv_print_method_to_file(phase_name, false, &fr);
5294   }
5295 }
5296 
5297 // Called from debugger. Normal write to the default _printer. Only works if Ideal Graph Visualizer printing flags are set.
5298 void igv_print_default() {
5299   Compile::current()->print_method(PHASE_DEBUG, 0);
5300 }
5301 
5302 // Called from debugger, especially when replaying a trace in which the program state cannot be altered like with rr replay.
5303 // A method is appended to an existing default file with the default phase name. This means that igv_append() must follow
5304 // an earlier igv_print(*) call which sets up the file. This works regardless of any Ideal Graph Visualizer flags set or not.
5305 // Use in debugger (gdb/rr): p igv_append($sp, $fp, $pc).
5306 void igv_append(void* sp, void* fp, void* pc) {
5307   frame fr(sp, fp, pc);
5308   Compile::current()->igv_print_method_to_file(nullptr, true, &fr);
5309 }
5310 
5311 // Same as igv_append(...) above but with a specified phase name.
5312 // Use in debugger (gdb/rr): p igv_append("MyPhase", $sp, $fp, $pc).
5313 void igv_append(const char* phase_name, void* sp, void* fp, void* pc) {
5314   frame fr(sp, fp, pc);
5315   Compile::current()->igv_print_method_to_file(phase_name, true, &fr);
5316 }
5317 
5318 void Compile::igv_print_method_to_file(const char* phase_name, bool append, const frame* fr) {
5319   const char* file_name = "custom_debug.xml";
5320   if (_debug_file_printer == nullptr) {
5321     _debug_file_printer = new IdealGraphPrinter(C, file_name, append);
5322   } else {
5323     _debug_file_printer->update_compiled_method(C->method());
5324   }
5325   tty->print_cr("Method %s to %s", append ? "appended" : "printed", file_name);
5326   _debug_file_printer->print_graph(phase_name, fr);
5327 }
5328 
5329 void Compile::igv_print_method_to_network(const char* phase_name, const frame* fr) {
5330   ResourceMark rm;
5331   GrowableArray<const Node*> empty_list;
5332   igv_print_graph_to_network(phase_name, empty_list, fr);
5333 }
5334 
5335 void Compile::igv_print_graph_to_network(const char* name, GrowableArray<const Node*>& visible_nodes, const frame* fr) {
5336   if (_debug_network_printer == nullptr) {
5337     _debug_network_printer = new IdealGraphPrinter(C);
5338   } else {
5339     _debug_network_printer->update_compiled_method(C->method());
5340   }
5341   tty->print_cr("Method printed over network stream to IGV");
5342   _debug_network_printer->print(name, C->root(), visible_nodes, fr);
5343 }
5344 #endif // !PRODUCT
5345 
5346 Node* Compile::narrow_value(BasicType bt, Node* value, const Type* type, PhaseGVN* phase, bool transform_res) {
5347   if (type != nullptr && phase->type(value)->higher_equal(type)) {
5348     return value;
5349   }
5350   Node* result = nullptr;
5351   if (bt == T_BYTE) {
5352     result = phase->transform(new LShiftINode(value, phase->intcon(24)));
5353     result = new RShiftINode(result, phase->intcon(24));
5354   } else if (bt == T_BOOLEAN) {
5355     result = new AndINode(value, phase->intcon(0xFF));
5356   } else if (bt == T_CHAR) {
5357     result = new AndINode(value,phase->intcon(0xFFFF));
5358   } else {
5359     assert(bt == T_SHORT, "unexpected narrow type");
5360     result = phase->transform(new LShiftINode(value, phase->intcon(16)));
5361     result = new RShiftINode(result, phase->intcon(16));
5362   }
5363   if (transform_res) {
5364     result = phase->transform(result);
5365   }
5366   return result;
5367 }
5368 
5369 void Compile::record_method_not_compilable_oom() {
5370   record_method_not_compilable(CompilationMemoryStatistic::failure_reason_memlimit());
5371 }
5372 
5373 #ifndef PRODUCT
5374 // Collects all the control inputs from nodes on the worklist and from their data dependencies
5375 static void find_candidate_control_inputs(Unique_Node_List& worklist, Unique_Node_List& candidates) {
5376   // Follow non-control edges until we reach CFG nodes
5377   for (uint i = 0; i < worklist.size(); i++) {
5378     const Node* n = worklist.at(i);
5379     for (uint j = 0; j < n->req(); j++) {
5380       Node* in = n->in(j);
5381       if (in == nullptr || in->is_Root()) {
5382         continue;
5383       }
5384       if (in->is_CFG()) {
5385         if (in->is_Call()) {
5386           // The return value of a call is only available if the call did not result in an exception
5387           Node* control_proj_use = in->as_Call()->proj_out(TypeFunc::Control)->unique_out();
5388           if (control_proj_use->is_Catch()) {
5389             Node* fall_through = control_proj_use->as_Catch()->proj_out(CatchProjNode::fall_through_index);
5390             candidates.push(fall_through);
5391             continue;
5392           }
5393         }
5394 
5395         if (in->is_Multi()) {
5396           // We got here by following data inputs so we should only have one control use
5397           // (no IfNode, etc)
5398           assert(!n->is_MultiBranch(), "unexpected node type: %s", n->Name());
5399           candidates.push(in->as_Multi()->proj_out(TypeFunc::Control));
5400         } else {
5401           candidates.push(in);
5402         }
5403       } else {
5404         worklist.push(in);
5405       }
5406     }
5407   }
5408 }
5409 
5410 // Returns the candidate node that is a descendant to all the other candidates
5411 static Node* pick_control(Unique_Node_List& candidates) {
5412   Unique_Node_List worklist;
5413   worklist.copy(candidates);
5414 
5415   // Traverse backwards through the CFG
5416   for (uint i = 0; i < worklist.size(); i++) {
5417     const Node* n = worklist.at(i);
5418     if (n->is_Root()) {
5419       continue;
5420     }
5421     for (uint j = 0; j < n->req(); j++) {
5422       // Skip backedge of loops to avoid cycles
5423       if (n->is_Loop() && j == LoopNode::LoopBackControl) {
5424         continue;
5425       }
5426 
5427       Node* pred = n->in(j);
5428       if (pred != nullptr && pred != n && pred->is_CFG()) {
5429         worklist.push(pred);
5430         // if pred is an ancestor of n, then pred is an ancestor to at least one candidate
5431         candidates.remove(pred);
5432       }
5433     }
5434   }
5435 
5436   assert(candidates.size() == 1, "unexpected control flow");
5437   return candidates.at(0);
5438 }
5439 
5440 // Initialize a parameter input for a debug print call, using a placeholder for jlong and jdouble
5441 static void debug_print_init_parm(Node* call, Node* parm, Node* half, int* pos) {
5442   call->init_req((*pos)++, parm);
5443   const BasicType bt = parm->bottom_type()->basic_type();
5444   if (bt == T_LONG || bt == T_DOUBLE) {
5445     call->init_req((*pos)++, half);
5446   }
5447 }
5448 
5449 Node* Compile::make_debug_print_call(const char* str, address call_addr, PhaseGVN* gvn,
5450                               Node* parm0, Node* parm1,
5451                               Node* parm2, Node* parm3,
5452                               Node* parm4, Node* parm5,
5453                               Node* parm6) const {
5454   Node* str_node = gvn->transform(new ConPNode(TypeRawPtr::make(((address) str))));
5455   const TypeFunc* type = OptoRuntime::debug_print_Type(parm0, parm1, parm2, parm3, parm4, parm5, parm6);
5456   Node* call = new CallLeafNode(type, call_addr, "debug_print", TypeRawPtr::BOTTOM);
5457 
5458   // find the most suitable control input
5459   Unique_Node_List worklist, candidates;
5460   if (parm0 != nullptr) { worklist.push(parm0);
5461   if (parm1 != nullptr) { worklist.push(parm1);
5462   if (parm2 != nullptr) { worklist.push(parm2);
5463   if (parm3 != nullptr) { worklist.push(parm3);
5464   if (parm4 != nullptr) { worklist.push(parm4);
5465   if (parm5 != nullptr) { worklist.push(parm5);
5466   if (parm6 != nullptr) { worklist.push(parm6);
5467   /* close each nested if ===> */  } } } } } } }
5468   find_candidate_control_inputs(worklist, candidates);
5469   Node* control = nullptr;
5470   if (candidates.size() == 0) {
5471     control = C->start()->proj_out(TypeFunc::Control);
5472   } else {
5473     control = pick_control(candidates);
5474   }
5475 
5476   // find all the previous users of the control we picked
5477   GrowableArray<Node*> users_of_control;
5478   for (DUIterator_Fast kmax, i = control->fast_outs(kmax); i < kmax; i++) {
5479     Node* use = control->fast_out(i);
5480     if (use->is_CFG() && use != control) {
5481       users_of_control.push(use);
5482     }
5483   }
5484 
5485   // we do not actually care about IO and memory as it uses neither
5486   call->init_req(TypeFunc::Control,   control);
5487   call->init_req(TypeFunc::I_O,       top());
5488   call->init_req(TypeFunc::Memory,    top());
5489   call->init_req(TypeFunc::FramePtr,  C->start()->proj_out(TypeFunc::FramePtr));
5490   call->init_req(TypeFunc::ReturnAdr, top());
5491 
5492   int pos = TypeFunc::Parms;
5493   call->init_req(pos++, str_node);
5494   if (parm0 != nullptr) { debug_print_init_parm(call, parm0, top(), &pos);
5495   if (parm1 != nullptr) { debug_print_init_parm(call, parm1, top(), &pos);
5496   if (parm2 != nullptr) { debug_print_init_parm(call, parm2, top(), &pos);
5497   if (parm3 != nullptr) { debug_print_init_parm(call, parm3, top(), &pos);
5498   if (parm4 != nullptr) { debug_print_init_parm(call, parm4, top(), &pos);
5499   if (parm5 != nullptr) { debug_print_init_parm(call, parm5, top(), &pos);
5500   if (parm6 != nullptr) { debug_print_init_parm(call, parm6, top(), &pos);
5501   /* close each nested if ===> */  } } } } } } }
5502   assert(call->in(call->req()-1) != nullptr, "must initialize all parms");
5503 
5504   call = gvn->transform(call);
5505   Node* call_control_proj = gvn->transform(new ProjNode(call, TypeFunc::Control));
5506 
5507   // rewire previous users to have the new call as control instead
5508   PhaseIterGVN* igvn = gvn->is_IterGVN();
5509   for (int i = 0; i < users_of_control.length(); i++) {
5510     Node* use = users_of_control.at(i);
5511     for (uint j = 0; j < use->req(); j++) {
5512       if (use->in(j) == control) {
5513         if (igvn != nullptr) {
5514           igvn->replace_input_of(use, j, call_control_proj);
5515         } else {
5516           gvn->hash_delete(use);
5517           use->set_req(j, call_control_proj);
5518           gvn->hash_insert(use);
5519         }
5520       }
5521     }
5522   }
5523 
5524   return call;
5525 }
5526 #endif // !PRODUCT