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]");
 572     } else if (env()->task()->is_precompile()) {
 573       if (for_preload()) {
 574         tty->print("[PRE]");
 575       } else {
 576         tty->print("[AOT]");
 577       }
 578     }
 579     tty->print("%3d", _compile_id);
 580   }
 581 #endif
 582 }
 583 
 584 #ifndef PRODUCT
 585 void Compile::print_phase(const char* phase_name) {
 586   tty->print_cr("%u.\t%s", ++_phase_counter, phase_name);
 587 }
 588 
 589 void Compile::print_ideal_ir(const char* compile_phase_name) const {
 590   // keep the following output all in one block
 591   // This output goes directly to the tty, not the compiler log.
 592   // To enable tools to match it up with the compilation activity,
 593   // be sure to tag this tty output with the compile ID.
 594 
 595   // Node dumping can cause a safepoint, which can break the tty lock.
 596   // Buffer all node dumps, so that all safepoints happen before we lock.
 597   ResourceMark rm;
 598   stringStream ss;
 599 
 600   if (_output == nullptr) {
 601     ss.print_cr("AFTER: %s", compile_phase_name);
 602     // Print out all nodes in ascending order of index.
 603     // It is important that we traverse both inputs and outputs of nodes,
 604     // so that we reach all nodes that are connected to Root.
 605     root()->dump_bfs(MaxNodeLimit, nullptr, "-+S$", &ss);
 606   } else {
 607     // Dump the node blockwise if we have a scheduling
 608     _output->print_scheduling(&ss);
 609   }
 610 
 611   // Check that the lock is not broken by a safepoint.
 612   NoSafepointVerifier nsv;
 613   ttyLocker ttyl;
 614   if (xtty != nullptr) {
 615     xtty->head("ideal compile_id='%d'%s compile_phase='%s'",
 616                compile_id(),
 617                is_osr_compilation() ? " compile_kind='osr'" :
 618                (for_preload() ? " compile_kind='AP'" : ""),
 619                compile_phase_name);
 620   }
 621 
 622   tty->print("%s", ss.as_string());
 623 
 624   if (xtty != nullptr) {
 625     xtty->tail("ideal");
 626   }
 627 }
 628 #endif
 629 
 630 // ============================================================================
 631 //------------------------------Compile standard-------------------------------
 632 
 633 // Compile a method.  entry_bci is -1 for normal compilations and indicates
 634 // the continuation bci for on stack replacement.
 635 
 636 
 637 Compile::Compile(ciEnv* ci_env, ciMethod* target, int osr_bci,
 638                  Options options, DirectiveSet* directive)
 639     : Phase(Compiler),
 640       _compile_id(ci_env->compile_id()),
 641       _options(options),
 642       _method(target),
 643       _entry_bci(osr_bci),
 644       _ilt(nullptr),
 645       _stub_function(nullptr),
 646       _stub_name(nullptr),
 647       _stub_id(StubId::NO_STUBID),
 648       _stub_entry_point(nullptr),
 649       _max_node_limit(MaxNodeLimit),
 650       _post_loop_opts_phase(false),
 651       _merge_stores_phase(false),
 652       _allow_macro_nodes(true),
 653       _inlining_progress(false),
 654       _inlining_incrementally(false),
 655       _do_cleanup(false),
 656       _has_reserved_stack_access(target->has_reserved_stack_access()),
 657 #ifndef PRODUCT
 658       _igv_idx(0),
 659       _trace_opto_output(directive->TraceOptoOutputOption),
 660 #endif
 661       _clinit_barrier_on_entry(false),
 662       _has_clinit_barriers(false),
 663       _stress_seed(0),
 664       _comp_arena(mtCompiler, Arena::Tag::tag_comp),
 665       _barrier_set_state(BarrierSet::barrier_set()->barrier_set_c2()->create_barrier_state(comp_arena())),
 666       _env(ci_env),
 667       _directive(directive),
 668       _log(ci_env->log()),
 669       _first_failure_details(nullptr),
 670       _intrinsics(comp_arena(), 0, 0, nullptr),
 671       _macro_nodes(comp_arena(), 8, 0, nullptr),
 672       _parse_predicates(comp_arena(), 8, 0, nullptr),
 673       _template_assertion_predicate_opaques(comp_arena(), 8, 0, nullptr),
 674       _expensive_nodes(comp_arena(), 8, 0, nullptr),
 675       _for_post_loop_igvn(comp_arena(), 8, 0, nullptr),
 676       _for_merge_stores_igvn(comp_arena(), 8, 0, nullptr),
 677       _unstable_if_traps(comp_arena(), 8, 0, nullptr),
 678       _coarsened_locks(comp_arena(), 8, 0, nullptr),
 679       _congraph(nullptr),
 680       NOT_PRODUCT(_igv_printer(nullptr) COMMA)
 681       _unique(0),
 682       _dead_node_count(0),
 683       _dead_node_list(comp_arena()),
 684       _node_arena_one(mtCompiler, Arena::Tag::tag_node),
 685       _node_arena_two(mtCompiler, Arena::Tag::tag_node),
 686       _node_arena(&_node_arena_one),
 687       _mach_constant_base_node(nullptr),
 688       _Compile_types(mtCompiler, Arena::Tag::tag_type),
 689       _initial_gvn(nullptr),
 690       _igvn_worklist(nullptr),
 691       _types(nullptr),
 692       _node_hash(nullptr),
 693       _late_inlines(comp_arena(), 2, 0, nullptr),
 694       _string_late_inlines(comp_arena(), 2, 0, nullptr),
 695       _boxing_late_inlines(comp_arena(), 2, 0, nullptr),
 696       _vector_reboxing_late_inlines(comp_arena(), 2, 0, nullptr),
 697       _late_inlines_pos(0),
 698       _has_mh_late_inlines(false),
 699       _oom(false),
 700       _replay_inline_data(nullptr),
 701       _inline_printer(this),
 702       _java_calls(0),
 703       _inner_loops(0),
 704       _FIRST_STACK_mask(comp_arena()),
 705       _interpreter_frame_size(0),
 706       _regmask_arena(mtCompiler, Arena::Tag::tag_regmask),
 707       _output(nullptr)
 708 #ifndef PRODUCT
 709       ,
 710       _in_dump_cnt(0)
 711 #endif
 712 {
 713   C = this;
 714   CompileWrapper cw(this);
 715 
 716   TraceTime t1("Total compilation time", &_t_totalCompilation, CITime, CITimeVerbose);
 717   TraceTime t2(nullptr, &_t_methodCompilation, CITime, false);
 718 
 719 #if defined(SUPPORT_ASSEMBLY) || defined(SUPPORT_ABSTRACT_ASSEMBLY)
 720   bool print_opto_assembly = directive->PrintOptoAssemblyOption;
 721   // We can always print a disassembly, either abstract (hex dump) or
 722   // with the help of a suitable hsdis library. Thus, we should not
 723   // couple print_assembly and print_opto_assembly controls.
 724   // But: always print opto and regular assembly on compile command 'print'.
 725   bool print_assembly = directive->PrintAssemblyOption;
 726   set_print_assembly(print_opto_assembly || print_assembly);
 727 #else
 728   set_print_assembly(false); // must initialize.
 729 #endif
 730 
 731 #ifndef PRODUCT
 732   set_parsed_irreducible_loop(false);
 733 #endif
 734 
 735   if (directive->ReplayInlineOption) {
 736     _replay_inline_data = ciReplay::load_inline_data(method(), entry_bci(), ci_env->comp_level());
 737   }
 738   set_print_inlining(directive->PrintInliningOption || PrintOptoInlining);
 739   set_print_intrinsics(directive->PrintIntrinsicsOption);
 740   set_has_irreducible_loop(true); // conservative until build_loop_tree() reset it
 741 
 742   if (ProfileTraps) {
 743     // Make sure the method being compiled gets its own MDO,
 744     // so we can at least track the decompile_count().
 745     method()->ensure_method_data();
 746   }
 747 
 748   if (StressLCM || StressGCM || StressIGVN || StressCCP ||
 749       StressIncrementalInlining || StressMacroExpansion ||
 750       StressMacroElimination || StressUnstableIfTraps ||
 751       StressBailout || StressLoopPeeling) {
 752     initialize_stress_seed(directive);
 753   }
 754 
 755   Init(/*do_aliasing=*/ true);
 756 
 757   print_compile_messages();
 758 
 759   _ilt = InlineTree::build_inline_tree_root();
 760 
 761   // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
 762   assert(num_alias_types() >= AliasIdxRaw, "");
 763 
 764 #define MINIMUM_NODE_HASH  1023
 765 
 766   // GVN that will be run immediately on new nodes
 767   uint estimated_size = method()->code_size()*4+64;
 768   estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
 769   _igvn_worklist = new (comp_arena()) Unique_Node_List(comp_arena());
 770   _types = new (comp_arena()) Type_Array(comp_arena());
 771   _node_hash = new (comp_arena()) NodeHash(comp_arena(), estimated_size);
 772   PhaseGVN gvn;
 773   set_initial_gvn(&gvn);
 774 
 775   { // Scope for timing the parser
 776     TracePhase tp(_t_parser);
 777 
 778     // Put top into the hash table ASAP.
 779     initial_gvn()->transform(top());
 780 
 781     // Set up tf(), start(), and find a CallGenerator.
 782     CallGenerator* cg = nullptr;
 783     if (is_osr_compilation()) {
 784       const TypeTuple *domain = StartOSRNode::osr_domain();
 785       const TypeTuple *range = TypeTuple::make_range(method()->signature());
 786       init_tf(TypeFunc::make(domain, range));
 787       StartNode* s = new StartOSRNode(root(), domain);
 788       initial_gvn()->set_type_bottom(s);
 789       verify_start(s);
 790       cg = CallGenerator::for_osr(method(), entry_bci());
 791     } else {
 792       // Normal case.
 793       init_tf(TypeFunc::make(method()));
 794       StartNode* s = new StartNode(root(), tf()->domain());
 795       initial_gvn()->set_type_bottom(s);
 796       verify_start(s);
 797       float past_uses = method()->interpreter_invocation_count();
 798       float expected_uses = past_uses;
 799       cg = CallGenerator::for_inline(method(), expected_uses);
 800     }
 801     if (failing())  return;
 802     if (cg == nullptr) {
 803       const char* reason = InlineTree::check_can_parse(method());
 804       assert(reason != nullptr, "expect reason for parse failure");
 805       stringStream ss;
 806       ss.print("cannot parse method: %s", reason);
 807       record_method_not_compilable(ss.as_string());
 808       return;
 809     }
 810 
 811     gvn.set_type(root(), root()->bottom_type());
 812 
 813     JVMState* jvms = build_start_state(start(), tf());
 814     if ((jvms = cg->generate(jvms)) == nullptr) {
 815       assert(failure_reason() != nullptr, "expect reason for parse failure");
 816       stringStream ss;
 817       ss.print("method parse failed: %s", failure_reason());
 818       record_method_not_compilable(ss.as_string() DEBUG_ONLY(COMMA true));
 819       return;
 820     }
 821     GraphKit kit(jvms);
 822 
 823     if (!kit.stopped()) {
 824       // Accept return values, and transfer control we know not where.
 825       // This is done by a special, unique ReturnNode bound to root.
 826       return_values(kit.jvms());
 827     }
 828 
 829     if (kit.has_exceptions()) {
 830       // Any exceptions that escape from this call must be rethrown
 831       // to whatever caller is dynamically above us on the stack.
 832       // This is done by a special, unique RethrowNode bound to root.
 833       rethrow_exceptions(kit.transfer_exceptions_into_jvms());
 834     }
 835 
 836     assert(IncrementalInline || (_late_inlines.length() == 0 && !has_mh_late_inlines()), "incremental inlining is off");
 837 
 838     if (_late_inlines.length() == 0 && !has_mh_late_inlines() && !failing() && has_stringbuilder()) {
 839       inline_string_calls(true);
 840     }
 841 
 842     if (failing())  return;
 843 
 844     // Remove clutter produced by parsing.
 845     if (!failing()) {
 846       ResourceMark rm;
 847       PhaseRemoveUseless pru(initial_gvn(), *igvn_worklist());
 848     }
 849   }
 850 
 851   // Note:  Large methods are capped off in do_one_bytecode().
 852   if (failing())  return;
 853 
 854   // After parsing, node notes are no longer automagic.
 855   // They must be propagated by register_new_node_with_optimizer(),
 856   // clone(), or the like.
 857   set_default_node_notes(nullptr);
 858 
 859 #ifndef PRODUCT
 860   if (should_print_igv(1)) {
 861     _igv_printer->print_inlining();
 862   }
 863 #endif
 864 
 865   if (failing())  return;
 866   NOT_PRODUCT( verify_graph_edges(); )
 867 
 868   // Now optimize
 869   Optimize();
 870   if (failing())  return;
 871   NOT_PRODUCT( verify_graph_edges(); )
 872 
 873 #ifndef PRODUCT
 874   if (should_print_ideal()) {
 875     print_ideal_ir("PrintIdeal");
 876   }
 877 #endif
 878 
 879 #ifdef ASSERT
 880   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 881   bs->verify_gc_barriers(this, BarrierSetC2::BeforeCodeGen);
 882 #endif
 883 
 884   // Dump compilation data to replay it.
 885   if (directive->DumpReplayOption) {
 886     env()->dump_replay_data(_compile_id);
 887   }
 888   if (directive->DumpInlineOption && (ilt() != nullptr)) {
 889     env()->dump_inline_data(_compile_id);
 890   }
 891 
 892   // Now that we know the size of all the monitors we can add a fixed slot
 893   // for the original deopt pc.
 894   int next_slot = fixed_slots() + (sizeof(address) / VMRegImpl::stack_slot_size);
 895   set_fixed_slots(next_slot);
 896 
 897   // Compute when to use implicit null checks. Used by matching trap based
 898   // nodes and NullCheck optimization.
 899   set_allowed_deopt_reasons();
 900 
 901   // Now generate code
 902   Code_Gen();
 903 }
 904 
 905 //------------------------------Compile----------------------------------------
 906 // Compile a runtime stub
 907 Compile::Compile(ciEnv* ci_env,
 908                  TypeFunc_generator generator,
 909                  address stub_function,
 910                  const char* stub_name,
 911                  StubId stub_id,
 912                  int is_fancy_jump,
 913                  bool pass_tls,
 914                  bool return_pc,
 915                  DirectiveSet* directive)
 916     : Phase(Compiler),
 917       _compile_id(0),
 918       _options(Options::for_runtime_stub()),
 919       _method(nullptr),
 920       _entry_bci(InvocationEntryBci),
 921       _stub_function(stub_function),
 922       _stub_name(stub_name),
 923       _stub_id(stub_id),
 924       _stub_entry_point(nullptr),
 925       _max_node_limit(MaxNodeLimit),
 926       _post_loop_opts_phase(false),
 927       _merge_stores_phase(false),
 928       _allow_macro_nodes(true),
 929       _inlining_progress(false),
 930       _inlining_incrementally(false),
 931       _has_reserved_stack_access(false),
 932 #ifndef PRODUCT
 933       _igv_idx(0),
 934       _trace_opto_output(directive->TraceOptoOutputOption),
 935 #endif
 936       _clinit_barrier_on_entry(false),
 937       _has_clinit_barriers(false),
 938       _stress_seed(0),
 939       _comp_arena(mtCompiler, Arena::Tag::tag_comp),
 940       _barrier_set_state(BarrierSet::barrier_set()->barrier_set_c2()->create_barrier_state(comp_arena())),
 941       _env(ci_env),
 942       _directive(directive),
 943       _log(ci_env->log()),
 944       _first_failure_details(nullptr),
 945       _for_post_loop_igvn(comp_arena(), 8, 0, nullptr),
 946       _for_merge_stores_igvn(comp_arena(), 8, 0, nullptr),
 947       _congraph(nullptr),
 948       NOT_PRODUCT(_igv_printer(nullptr) COMMA)
 949       _unique(0),
 950       _dead_node_count(0),
 951       _dead_node_list(comp_arena()),
 952       _node_arena_one(mtCompiler, Arena::Tag::tag_node),
 953       _node_arena_two(mtCompiler, Arena::Tag::tag_node),
 954       _node_arena(&_node_arena_one),
 955       _mach_constant_base_node(nullptr),
 956       _Compile_types(mtCompiler, Arena::Tag::tag_type),
 957       _initial_gvn(nullptr),
 958       _igvn_worklist(nullptr),
 959       _types(nullptr),
 960       _node_hash(nullptr),
 961       _has_mh_late_inlines(false),
 962       _oom(false),
 963       _replay_inline_data(nullptr),
 964       _inline_printer(this),
 965       _java_calls(0),
 966       _inner_loops(0),
 967       _FIRST_STACK_mask(comp_arena()),
 968       _interpreter_frame_size(0),
 969       _regmask_arena(mtCompiler, Arena::Tag::tag_regmask),
 970       _output(nullptr),
 971 #ifndef PRODUCT
 972       _in_dump_cnt(0),
 973 #endif
 974       _allowed_reasons(0) {
 975   C = this;
 976 
 977   // try to reuse an existing stub
 978   {
 979     BlobId blob_id = StubInfo::blob(_stub_id);
 980     CodeBlob* blob = AOTCodeCache::load_code_blob(AOTCodeEntry::C2Blob, blob_id);
 981     if (blob != nullptr) {
 982       RuntimeStub* rs = blob->as_runtime_stub();
 983       _stub_entry_point = rs->entry_point();
 984       return;
 985     }
 986   }
 987 
 988   TraceTime t1(nullptr, &_t_totalCompilation, CITime, false);
 989   TraceTime t2(nullptr, &_t_stubCompilation, CITime, false);
 990 
 991 #ifndef PRODUCT
 992   set_print_assembly(PrintFrameConverterAssembly);
 993   set_parsed_irreducible_loop(false);
 994 #else
 995   set_print_assembly(false); // Must initialize.
 996 #endif
 997   set_has_irreducible_loop(false); // no loops
 998 
 999   CompileWrapper cw(this);
1000   Init(/*do_aliasing=*/ false);
1001   init_tf((*generator)());
1002 
1003   _igvn_worklist = new (comp_arena()) Unique_Node_List(comp_arena());
1004   _types = new (comp_arena()) Type_Array(comp_arena());
1005   _node_hash = new (comp_arena()) NodeHash(comp_arena(), 255);
1006 
1007   if (StressLCM || StressGCM || StressBailout) {
1008     initialize_stress_seed(directive);
1009   }
1010 
1011   {
1012     PhaseGVN gvn;
1013     set_initial_gvn(&gvn);    // not significant, but GraphKit guys use it pervasively
1014     gvn.transform(top());
1015 
1016     GraphKit kit;
1017     kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
1018   }
1019 
1020   NOT_PRODUCT( verify_graph_edges(); )
1021 
1022   Code_Gen();
1023 }
1024 
1025 Compile::~Compile() {
1026   delete _first_failure_details;
1027 };
1028 
1029 //------------------------------Init-------------------------------------------
1030 // Prepare for a single compilation
1031 void Compile::Init(bool aliasing) {
1032   _do_aliasing = aliasing;
1033   _unique  = 0;
1034   _regalloc = nullptr;
1035 
1036   _tf      = nullptr;  // filled in later
1037   _top     = nullptr;  // cached later
1038   _matcher = nullptr;  // filled in later
1039   _cfg     = nullptr;  // filled in later
1040 
1041   _node_note_array = nullptr;
1042   _default_node_notes = nullptr;
1043   DEBUG_ONLY( _modified_nodes = nullptr; ) // Used in Optimize()
1044 
1045   _immutable_memory = nullptr; // filled in at first inquiry
1046 
1047 #ifdef ASSERT
1048   _phase_optimize_finished = false;
1049   _phase_verify_ideal_loop = false;
1050   _exception_backedge = false;
1051   _type_verify = nullptr;
1052 #endif
1053 
1054   // Globally visible Nodes
1055   // First set TOP to null to give safe behavior during creation of RootNode
1056   set_cached_top_node(nullptr);
1057   set_root(new RootNode());
1058   // Now that you have a Root to point to, create the real TOP
1059   set_cached_top_node( new ConNode(Type::TOP) );
1060   set_recent_alloc(nullptr, nullptr);
1061 
1062   // Create Debug Information Recorder to record scopes, oopmaps, etc.
1063   env()->set_oop_recorder(new OopRecorder(env()->arena()));
1064   env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
1065   env()->set_dependencies(new Dependencies(env()));
1066 
1067   _fixed_slots = 0;
1068   set_has_split_ifs(false);
1069   set_has_loops(false); // first approximation
1070   set_has_stringbuilder(false);
1071   set_has_boxed_value(false);
1072   _trap_can_recompile = false;  // no traps emitted yet
1073   _major_progress = true; // start out assuming good things will happen
1074   set_has_unsafe_access(false);
1075   set_max_vector_size(0);
1076   set_clear_upper_avx(false);  //false as default for clear upper bits of ymm registers
1077   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
1078   set_decompile_count(0);
1079 
1080 #ifndef PRODUCT
1081   _phase_counter = 0;
1082   Copy::zero_to_bytes(_igv_phase_iter, sizeof(_igv_phase_iter));
1083 #endif
1084 
1085   set_do_freq_based_layout(_directive->BlockLayoutByFrequencyOption);
1086   _loop_opts_cnt = LoopOptsCount;
1087   set_do_inlining(Inline);
1088   set_max_inline_size(MaxInlineSize);
1089   set_freq_inline_size(FreqInlineSize);
1090   set_do_scheduling(OptoScheduling);
1091 
1092   set_do_vector_loop(false);
1093   set_has_monitors(false);
1094   set_has_scoped_access(false);
1095 
1096   if (AllowVectorizeOnDemand) {
1097     if (has_method() && _directive->VectorizeOption) {
1098       set_do_vector_loop(true);
1099       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());})
1100     } else if (has_method() && method()->name() != nullptr &&
1101                method()->intrinsic_id() == vmIntrinsics::_forEachRemaining) {
1102       set_do_vector_loop(true);
1103     }
1104   }
1105   set_use_cmove(UseCMoveUnconditionally /* || do_vector_loop()*/); //TODO: consider do_vector_loop() mandate use_cmove unconditionally
1106   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());})
1107 
1108   _max_node_limit = _directive->MaxNodeLimitOption;
1109 
1110   if (VM_Version::supports_fast_class_init_checks() && has_method() && !is_osr_compilation() &&
1111       (method()->needs_clinit_barrier() || (do_clinit_barriers() && method()->is_static()))) {
1112     set_clinit_barrier_on_entry(true);
1113     if (do_clinit_barriers()) {
1114       set_has_clinit_barriers(true); // Entry clinit barrier is in prolog code.
1115     }
1116   }
1117   if (debug_info()->recording_non_safepoints()) {
1118     set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
1119                         (comp_arena(), 8, 0, nullptr));
1120     set_default_node_notes(Node_Notes::make(this));
1121   }
1122 
1123   const int grow_ats = 16;
1124   _max_alias_types = grow_ats;
1125   _alias_types   = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
1126   AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType,  grow_ats);
1127   Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
1128   {
1129     for (int i = 0; i < grow_ats; i++)  _alias_types[i] = &ats[i];
1130   }
1131   // Initialize the first few types.
1132   _alias_types[AliasIdxTop]->Init(AliasIdxTop, nullptr);
1133   _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
1134   _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
1135   _num_alias_types = AliasIdxRaw+1;
1136   // Zero out the alias type cache.
1137   Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
1138   // A null adr_type hits in the cache right away.  Preload the right answer.
1139   probe_alias_cache(nullptr)->_index = AliasIdxTop;
1140 }
1141 
1142 #ifdef ASSERT
1143 // Verify that the current StartNode is valid.
1144 void Compile::verify_start(StartNode* s) const {
1145   assert(failing_internal() || s == start(), "should be StartNode");
1146 }
1147 #endif
1148 
1149 /**
1150  * Return the 'StartNode'. We must not have a pending failure, since the ideal graph
1151  * can be in an inconsistent state, i.e., we can get segmentation faults when traversing
1152  * the ideal graph.
1153  */
1154 StartNode* Compile::start() const {
1155   assert (!failing_internal() || C->failure_is_artificial(), "Must not have pending failure. Reason is: %s", failure_reason());
1156   for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
1157     Node* start = root()->fast_out(i);
1158     if (start->is_Start()) {
1159       return start->as_Start();
1160     }
1161   }
1162   fatal("Did not find Start node!");
1163   return nullptr;
1164 }
1165 
1166 //-------------------------------immutable_memory-------------------------------------
1167 // Access immutable memory
1168 Node* Compile::immutable_memory() {
1169   if (_immutable_memory != nullptr) {
1170     return _immutable_memory;
1171   }
1172   StartNode* s = start();
1173   for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
1174     Node *p = s->fast_out(i);
1175     if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
1176       _immutable_memory = p;
1177       return _immutable_memory;
1178     }
1179   }
1180   ShouldNotReachHere();
1181   return nullptr;
1182 }
1183 
1184 //----------------------set_cached_top_node------------------------------------
1185 // Install the cached top node, and make sure Node::is_top works correctly.
1186 void Compile::set_cached_top_node(Node* tn) {
1187   if (tn != nullptr)  verify_top(tn);
1188   Node* old_top = _top;
1189   _top = tn;
1190   // Calling Node::setup_is_top allows the nodes the chance to adjust
1191   // their _out arrays.
1192   if (_top != nullptr)     _top->setup_is_top();
1193   if (old_top != nullptr)  old_top->setup_is_top();
1194   assert(_top == nullptr || top()->is_top(), "");
1195 }
1196 
1197 #ifdef ASSERT
1198 uint Compile::count_live_nodes_by_graph_walk() {
1199   Unique_Node_List useful(comp_arena());
1200   // Get useful node list by walking the graph.
1201   identify_useful_nodes(useful);
1202   return useful.size();
1203 }
1204 
1205 void Compile::print_missing_nodes() {
1206 
1207   // Return if CompileLog is null and PrintIdealNodeCount is false.
1208   if ((_log == nullptr) && (! PrintIdealNodeCount)) {
1209     return;
1210   }
1211 
1212   // This is an expensive function. It is executed only when the user
1213   // specifies VerifyIdealNodeCount option or otherwise knows the
1214   // additional work that needs to be done to identify reachable nodes
1215   // by walking the flow graph and find the missing ones using
1216   // _dead_node_list.
1217 
1218   Unique_Node_List useful(comp_arena());
1219   // Get useful node list by walking the graph.
1220   identify_useful_nodes(useful);
1221 
1222   uint l_nodes = C->live_nodes();
1223   uint l_nodes_by_walk = useful.size();
1224 
1225   if (l_nodes != l_nodes_by_walk) {
1226     if (_log != nullptr) {
1227       _log->begin_head("mismatched_nodes count='%d'", abs((int) (l_nodes - l_nodes_by_walk)));
1228       _log->stamp();
1229       _log->end_head();
1230     }
1231     VectorSet& useful_member_set = useful.member_set();
1232     int last_idx = l_nodes_by_walk;
1233     for (int i = 0; i < last_idx; i++) {
1234       if (useful_member_set.test(i)) {
1235         if (_dead_node_list.test(i)) {
1236           if (_log != nullptr) {
1237             _log->elem("mismatched_node_info node_idx='%d' type='both live and dead'", i);
1238           }
1239           if (PrintIdealNodeCount) {
1240             // Print the log message to tty
1241               tty->print_cr("mismatched_node idx='%d' both live and dead'", i);
1242               useful.at(i)->dump();
1243           }
1244         }
1245       }
1246       else if (! _dead_node_list.test(i)) {
1247         if (_log != nullptr) {
1248           _log->elem("mismatched_node_info node_idx='%d' type='neither live nor dead'", i);
1249         }
1250         if (PrintIdealNodeCount) {
1251           // Print the log message to tty
1252           tty->print_cr("mismatched_node idx='%d' type='neither live nor dead'", i);
1253         }
1254       }
1255     }
1256     if (_log != nullptr) {
1257       _log->tail("mismatched_nodes");
1258     }
1259   }
1260 }
1261 void Compile::record_modified_node(Node* n) {
1262   if (_modified_nodes != nullptr && !_inlining_incrementally && !n->is_Con()) {
1263     _modified_nodes->push(n);
1264   }
1265 }
1266 
1267 void Compile::remove_modified_node(Node* n) {
1268   if (_modified_nodes != nullptr) {
1269     _modified_nodes->remove(n);
1270   }
1271 }
1272 #endif
1273 
1274 #ifndef PRODUCT
1275 void Compile::verify_top(Node* tn) const {
1276   if (tn != nullptr) {
1277     assert(tn->is_Con(), "top node must be a constant");
1278     assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
1279     assert(tn->in(0) != nullptr, "must have live top node");
1280   }
1281 }
1282 #endif
1283 
1284 
1285 ///-------------------Managing Per-Node Debug & Profile Info-------------------
1286 
1287 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
1288   guarantee(arr != nullptr, "");
1289   int num_blocks = arr->length();
1290   if (grow_by < num_blocks)  grow_by = num_blocks;
1291   int num_notes = grow_by * _node_notes_block_size;
1292   Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
1293   Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
1294   while (num_notes > 0) {
1295     arr->append(notes);
1296     notes     += _node_notes_block_size;
1297     num_notes -= _node_notes_block_size;
1298   }
1299   assert(num_notes == 0, "exact multiple, please");
1300 }
1301 
1302 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
1303   if (source == nullptr || dest == nullptr)  return false;
1304 
1305   if (dest->is_Con())
1306     return false;               // Do not push debug info onto constants.
1307 
1308 #ifdef ASSERT
1309   // Leave a bread crumb trail pointing to the original node:
1310   if (dest != nullptr && dest != source && dest->debug_orig() == nullptr) {
1311     dest->set_debug_orig(source);
1312   }
1313 #endif
1314 
1315   if (node_note_array() == nullptr)
1316     return false;               // Not collecting any notes now.
1317 
1318   // This is a copy onto a pre-existing node, which may already have notes.
1319   // If both nodes have notes, do not overwrite any pre-existing notes.
1320   Node_Notes* source_notes = node_notes_at(source->_idx);
1321   if (source_notes == nullptr || source_notes->is_clear())  return false;
1322   Node_Notes* dest_notes   = node_notes_at(dest->_idx);
1323   if (dest_notes == nullptr || dest_notes->is_clear()) {
1324     return set_node_notes_at(dest->_idx, source_notes);
1325   }
1326 
1327   Node_Notes merged_notes = (*source_notes);
1328   // The order of operations here ensures that dest notes will win...
1329   merged_notes.update_from(dest_notes);
1330   return set_node_notes_at(dest->_idx, &merged_notes);
1331 }
1332 
1333 
1334 //--------------------------allow_range_check_smearing-------------------------
1335 // Gating condition for coalescing similar range checks.
1336 // Sometimes we try 'speculatively' replacing a series of a range checks by a
1337 // single covering check that is at least as strong as any of them.
1338 // If the optimization succeeds, the simplified (strengthened) range check
1339 // will always succeed.  If it fails, we will deopt, and then give up
1340 // on the optimization.
1341 bool Compile::allow_range_check_smearing() const {
1342   // If this method has already thrown a range-check,
1343   // assume it was because we already tried range smearing
1344   // and it failed.
1345   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
1346   return !already_trapped;
1347 }
1348 
1349 
1350 //------------------------------flatten_alias_type-----------------------------
1351 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
1352   assert(do_aliasing(), "Aliasing should be enabled");
1353   int offset = tj->offset();
1354   TypePtr::PTR ptr = tj->ptr();
1355 
1356   // Known instance (scalarizable allocation) alias only with itself.
1357   bool is_known_inst = tj->isa_oopptr() != nullptr &&
1358                        tj->is_oopptr()->is_known_instance();
1359 
1360   // Process weird unsafe references.
1361   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
1362     assert(InlineUnsafeOps || StressReflectiveCode, "indeterminate pointers come only from unsafe ops");
1363     assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
1364     tj = TypeOopPtr::BOTTOM;
1365     ptr = tj->ptr();
1366     offset = tj->offset();
1367   }
1368 
1369   // Array pointers need some flattening
1370   const TypeAryPtr* ta = tj->isa_aryptr();
1371   if (ta && ta->is_stable()) {
1372     // Erase stability property for alias analysis.
1373     tj = ta = ta->cast_to_stable(false);
1374   }
1375   if( ta && is_known_inst ) {
1376     if ( offset != Type::OffsetBot &&
1377          offset > arrayOopDesc::length_offset_in_bytes() ) {
1378       offset = Type::OffsetBot; // Flatten constant access into array body only
1379       tj = ta = ta->
1380               remove_speculative()->
1381               cast_to_ptr_type(ptr)->
1382               with_offset(offset);
1383     }
1384   } else if (ta != nullptr) {
1385     // Common slices
1386     if (offset == arrayOopDesc::length_offset_in_bytes()) {
1387       return TypeAryPtr::RANGE;
1388     } else if (offset == oopDesc::klass_offset_in_bytes()) {
1389       return TypeInstPtr::KLASS;
1390     } else if (offset == oopDesc::mark_offset_in_bytes()) {
1391       return TypeInstPtr::MARK;
1392     }
1393 
1394     // Remove size and stability
1395     const TypeAry* normalized_ary = TypeAry::make(ta->elem(), TypeInt::POS, false);
1396     // Remove ptr, const_oop, and offset
1397     if (ta->elem() == Type::BOTTOM) {
1398       // Bottom array (meet of int[] and byte[] for example), accesses to it will be done with
1399       // Unsafe. This should alias with all arrays. For now just leave it as it is (this is
1400       // incorrect, see JDK-8331133).
1401       tj = ta = TypeAryPtr::make(TypePtr::BotPTR, nullptr, normalized_ary, nullptr, false, Type::OffsetBot);
1402     } else if (ta->elem()->make_oopptr() != nullptr) {
1403       // Object arrays, all of them share the same slice
1404       const TypeAry* tary = TypeAry::make(TypeInstPtr::BOTTOM, TypeInt::POS, false);
1405       tj = ta = TypeAryPtr::make(TypePtr::BotPTR, nullptr, tary, nullptr, false, Type::OffsetBot);
1406     } else {
1407       // Primitive arrays
1408       tj = ta = TypeAryPtr::make(TypePtr::BotPTR, nullptr, normalized_ary, ta->exact_klass(), true, Type::OffsetBot);
1409     }
1410 
1411     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
1412     // cannot be distinguished by bytecode alone.
1413     if (ta->elem() == TypeInt::BOOL) {
1414       tj = ta = TypeAryPtr::BYTES;
1415     }
1416   }
1417 
1418   // Oop pointers need some flattening
1419   const TypeInstPtr *to = tj->isa_instptr();
1420   if (to && to != TypeOopPtr::BOTTOM) {
1421     ciInstanceKlass* ik = to->instance_klass();
1422     if( ptr == TypePtr::Constant ) {
1423       if (ik != ciEnv::current()->Class_klass() ||
1424           offset < ik->layout_helper_size_in_bytes()) {
1425         // No constant oop pointers (such as Strings); they alias with
1426         // unknown strings.
1427         assert(!is_known_inst, "not scalarizable allocation");
1428         tj = to = to->
1429                 cast_to_instance_id(TypeOopPtr::InstanceBot)->
1430                 remove_speculative()->
1431                 cast_to_ptr_type(TypePtr::BotPTR)->
1432                 cast_to_exactness(false);
1433       }
1434     } else if( is_known_inst ) {
1435       tj = to; // Keep NotNull and klass_is_exact for instance type
1436     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
1437       // During the 2nd round of IterGVN, NotNull castings are removed.
1438       // Make sure the Bottom and NotNull variants alias the same.
1439       // Also, make sure exact and non-exact variants alias the same.
1440       tj = to = to->
1441               remove_speculative()->
1442               cast_to_instance_id(TypeOopPtr::InstanceBot)->
1443               cast_to_ptr_type(TypePtr::BotPTR)->
1444               cast_to_exactness(false);
1445     }
1446     if (to->speculative() != nullptr) {
1447       tj = to = to->remove_speculative();
1448     }
1449     // Canonicalize the holder of this field
1450     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
1451       // First handle header references such as a LoadKlassNode, even if the
1452       // object's klass is unloaded at compile time (4965979).
1453       if (!is_known_inst) { // Do it only for non-instance types
1454         tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, nullptr, offset);
1455       }
1456     } else if (offset < 0 || offset >= ik->layout_helper_size_in_bytes()) {
1457       // Static fields are in the space above the normal instance
1458       // fields in the java.lang.Class instance.
1459       if (ik != ciEnv::current()->Class_klass()) {
1460         to = nullptr;
1461         tj = TypeOopPtr::BOTTOM;
1462         offset = tj->offset();
1463       }
1464     } else {
1465       ciInstanceKlass *canonical_holder = ik->get_canonical_holder(offset);
1466       assert(offset < canonical_holder->layout_helper_size_in_bytes(), "");
1467       assert(tj->offset() == offset, "no change to offset expected");
1468       bool xk = to->klass_is_exact();
1469       int instance_id = to->instance_id();
1470 
1471       // If the input type's class is the holder: if exact, the type only includes interfaces implemented by the holder
1472       // but if not exact, it may include extra interfaces: build new type from the holder class to make sure only
1473       // its interfaces are included.
1474       if (xk && ik->equals(canonical_holder)) {
1475         assert(tj == TypeInstPtr::make(to->ptr(), canonical_holder, is_known_inst, nullptr, offset, instance_id), "exact type should be canonical type");
1476       } else {
1477         assert(xk || !is_known_inst, "Known instance should be exact type");
1478         tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, is_known_inst, nullptr, offset, instance_id);
1479       }
1480     }
1481   }
1482 
1483   // Klass pointers to object array klasses need some flattening
1484   const TypeKlassPtr *tk = tj->isa_klassptr();
1485   if( tk ) {
1486     // If we are referencing a field within a Klass, we need
1487     // to assume the worst case of an Object.  Both exact and
1488     // inexact types must flatten to the same alias class so
1489     // use NotNull as the PTR.
1490     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
1491       tj = tk = TypeInstKlassPtr::make(TypePtr::NotNull,
1492                                        env()->Object_klass(),
1493                                        offset);
1494     }
1495 
1496     if (tk->isa_aryklassptr() && tk->is_aryklassptr()->elem()->isa_klassptr()) {
1497       ciKlass* k = ciObjArrayKlass::make(env()->Object_klass());
1498       if (!k || !k->is_loaded()) {                  // Only fails for some -Xcomp runs
1499         tj = tk = TypeInstKlassPtr::make(TypePtr::NotNull, env()->Object_klass(), offset);
1500       } else {
1501         tj = tk = TypeAryKlassPtr::make(TypePtr::NotNull, tk->is_aryklassptr()->elem(), k, offset);
1502       }
1503     }
1504 
1505     // Check for precise loads from the primary supertype array and force them
1506     // to the supertype cache alias index.  Check for generic array loads from
1507     // the primary supertype array and also force them to the supertype cache
1508     // alias index.  Since the same load can reach both, we need to merge
1509     // these 2 disparate memories into the same alias class.  Since the
1510     // primary supertype array is read-only, there's no chance of confusion
1511     // where we bypass an array load and an array store.
1512     int primary_supers_offset = in_bytes(Klass::primary_supers_offset());
1513     if (offset == Type::OffsetBot ||
1514         (offset >= primary_supers_offset &&
1515          offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
1516         offset == (int)in_bytes(Klass::secondary_super_cache_offset())) {
1517       offset = in_bytes(Klass::secondary_super_cache_offset());
1518       tj = tk = tk->with_offset(offset);
1519     }
1520   }
1521 
1522   // Flatten all Raw pointers together.
1523   if (tj->base() == Type::RawPtr)
1524     tj = TypeRawPtr::BOTTOM;
1525 
1526   if (tj->base() == Type::AnyPtr)
1527     tj = TypePtr::BOTTOM;      // An error, which the caller must check for.
1528 
1529   offset = tj->offset();
1530   assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
1531 
1532   assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
1533           (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
1534           (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
1535           (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
1536           (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1537           (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1538           (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr),
1539           "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
1540   assert( tj->ptr() != TypePtr::TopPTR &&
1541           tj->ptr() != TypePtr::AnyNull &&
1542           tj->ptr() != TypePtr::Null, "No imprecise addresses" );
1543 //    assert( tj->ptr() != TypePtr::Constant ||
1544 //            tj->base() == Type::RawPtr ||
1545 //            tj->base() == Type::KlassPtr, "No constant oop addresses" );
1546 
1547   return tj;
1548 }
1549 
1550 void Compile::AliasType::Init(int i, const TypePtr* at) {
1551   assert(AliasIdxTop <= i && i < Compile::current()->_max_alias_types, "Invalid alias index");
1552   _index = i;
1553   _adr_type = at;
1554   _field = nullptr;
1555   _element = nullptr;
1556   _is_rewritable = true; // default
1557   const TypeOopPtr *atoop = (at != nullptr) ? at->isa_oopptr() : nullptr;
1558   if (atoop != nullptr && atoop->is_known_instance()) {
1559     const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
1560     _general_index = Compile::current()->get_alias_index(gt);
1561   } else {
1562     _general_index = 0;
1563   }
1564 }
1565 
1566 BasicType Compile::AliasType::basic_type() const {
1567   if (element() != nullptr) {
1568     const Type* element = adr_type()->is_aryptr()->elem();
1569     return element->isa_narrowoop() ? T_OBJECT : element->array_element_basic_type();
1570   } if (field() != nullptr) {
1571     return field()->layout_type();
1572   } else {
1573     return T_ILLEGAL; // unknown
1574   }
1575 }
1576 
1577 //---------------------------------print_on------------------------------------
1578 #ifndef PRODUCT
1579 void Compile::AliasType::print_on(outputStream* st) {
1580   if (index() < 10)
1581         st->print("@ <%d> ", index());
1582   else  st->print("@ <%d>",  index());
1583   st->print(is_rewritable() ? "   " : " RO");
1584   int offset = adr_type()->offset();
1585   if (offset == Type::OffsetBot)
1586         st->print(" +any");
1587   else  st->print(" +%-3d", offset);
1588   st->print(" in ");
1589   adr_type()->dump_on(st);
1590   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
1591   if (field() != nullptr && tjp) {
1592     if (tjp->is_instptr()->instance_klass()  != field()->holder() ||
1593         tjp->offset() != field()->offset_in_bytes()) {
1594       st->print(" != ");
1595       field()->print();
1596       st->print(" ***");
1597     }
1598   }
1599 }
1600 
1601 void print_alias_types() {
1602   Compile* C = Compile::current();
1603   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
1604   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
1605     C->alias_type(idx)->print_on(tty);
1606     tty->cr();
1607   }
1608 }
1609 #endif
1610 
1611 
1612 //----------------------------probe_alias_cache--------------------------------
1613 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
1614   intptr_t key = (intptr_t) adr_type;
1615   key ^= key >> logAliasCacheSize;
1616   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
1617 }
1618 
1619 
1620 //-----------------------------grow_alias_types--------------------------------
1621 void Compile::grow_alias_types() {
1622   const int old_ats  = _max_alias_types; // how many before?
1623   const int new_ats  = old_ats;          // how many more?
1624   const int grow_ats = old_ats+new_ats;  // how many now?
1625   _max_alias_types = grow_ats;
1626   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
1627   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
1628   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
1629   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
1630 }
1631 
1632 
1633 //--------------------------------find_alias_type------------------------------
1634 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field) {
1635   if (!do_aliasing()) {
1636     return alias_type(AliasIdxBot);
1637   }
1638 
1639   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1640   if (ace->_adr_type == adr_type) {
1641     return alias_type(ace->_index);
1642   }
1643 
1644   // Handle special cases.
1645   if (adr_type == nullptr)          return alias_type(AliasIdxTop);
1646   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
1647 
1648   // Do it the slow way.
1649   const TypePtr* flat = flatten_alias_type(adr_type);
1650 
1651 #ifdef ASSERT
1652   {
1653     ResourceMark rm;
1654     assert(flat == flatten_alias_type(flat), "not idempotent: adr_type = %s; flat = %s => %s",
1655            Type::str(adr_type), Type::str(flat), Type::str(flatten_alias_type(flat)));
1656     assert(flat != TypePtr::BOTTOM, "cannot alias-analyze an untyped ptr: adr_type = %s",
1657            Type::str(adr_type));
1658     if (flat->isa_oopptr() && !flat->isa_klassptr()) {
1659       const TypeOopPtr* foop = flat->is_oopptr();
1660       // Scalarizable allocations have exact klass always.
1661       bool exact = !foop->klass_is_exact() || foop->is_known_instance();
1662       const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
1663       assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type: foop = %s; xoop = %s",
1664              Type::str(foop), Type::str(xoop));
1665     }
1666   }
1667 #endif
1668 
1669   int idx = AliasIdxTop;
1670   for (int i = 0; i < num_alias_types(); i++) {
1671     if (alias_type(i)->adr_type() == flat) {
1672       idx = i;
1673       break;
1674     }
1675   }
1676 
1677   if (idx == AliasIdxTop) {
1678     if (no_create)  return nullptr;
1679     // Grow the array if necessary.
1680     if (_num_alias_types == _max_alias_types)  grow_alias_types();
1681     // Add a new alias type.
1682     idx = _num_alias_types++;
1683     _alias_types[idx]->Init(idx, flat);
1684     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
1685     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
1686     if (flat->isa_instptr()) {
1687       if (flat->offset() == java_lang_Class::klass_offset()
1688           && flat->is_instptr()->instance_klass() == env()->Class_klass())
1689         alias_type(idx)->set_rewritable(false);
1690     }
1691     if (flat->isa_aryptr()) {
1692 #ifdef ASSERT
1693       const int header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1694       // (T_BYTE has the weakest alignment and size restrictions...)
1695       assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
1696 #endif
1697       if (flat->offset() == TypePtr::OffsetBot) {
1698         alias_type(idx)->set_element(flat->is_aryptr()->elem());
1699       }
1700     }
1701     if (flat->isa_klassptr()) {
1702       if (UseCompactObjectHeaders) {
1703         if (flat->offset() == in_bytes(Klass::prototype_header_offset()))
1704           alias_type(idx)->set_rewritable(false);
1705       }
1706       if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
1707         alias_type(idx)->set_rewritable(false);
1708       if (flat->offset() == in_bytes(Klass::misc_flags_offset()))
1709         alias_type(idx)->set_rewritable(false);
1710       if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
1711         alias_type(idx)->set_rewritable(false);
1712       if (flat->offset() == in_bytes(Klass::secondary_super_cache_offset()))
1713         alias_type(idx)->set_rewritable(false);
1714     }
1715 
1716     if (flat->isa_instklassptr()) {
1717       if (flat->offset() == in_bytes(InstanceKlass::access_flags_offset())) {
1718         alias_type(idx)->set_rewritable(false);
1719       }
1720     }
1721     // %%% (We would like to finalize JavaThread::threadObj_offset(),
1722     // but the base pointer type is not distinctive enough to identify
1723     // references into JavaThread.)
1724 
1725     // Check for final fields.
1726     const TypeInstPtr* tinst = flat->isa_instptr();
1727     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
1728       ciField* field;
1729       if (tinst->const_oop() != nullptr &&
1730           tinst->instance_klass() == ciEnv::current()->Class_klass() &&
1731           tinst->offset() >= (tinst->instance_klass()->layout_helper_size_in_bytes())) {
1732         // static field
1733         ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
1734         field = k->get_field_by_offset(tinst->offset(), true);
1735       } else {
1736         ciInstanceKlass *k = tinst->instance_klass();
1737         field = k->get_field_by_offset(tinst->offset(), false);
1738       }
1739       assert(field == nullptr ||
1740              original_field == nullptr ||
1741              (field->holder() == original_field->holder() &&
1742               field->offset_in_bytes() == original_field->offset_in_bytes() &&
1743               field->is_static() == original_field->is_static()), "wrong field?");
1744       // Set field() and is_rewritable() attributes.
1745       if (field != nullptr)  alias_type(idx)->set_field(field);
1746     }
1747   }
1748 
1749   // Fill the cache for next time.
1750   ace->_adr_type = adr_type;
1751   ace->_index    = idx;
1752   assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
1753 
1754   // Might as well try to fill the cache for the flattened version, too.
1755   AliasCacheEntry* face = probe_alias_cache(flat);
1756   if (face->_adr_type == nullptr) {
1757     face->_adr_type = flat;
1758     face->_index    = idx;
1759     assert(alias_type(flat) == alias_type(idx), "flat type must work too");
1760   }
1761 
1762   return alias_type(idx);
1763 }
1764 
1765 
1766 Compile::AliasType* Compile::alias_type(ciField* field) {
1767   const TypeOopPtr* t;
1768   if (field->is_static())
1769     t = TypeInstPtr::make(field->holder()->java_mirror());
1770   else
1771     t = TypeOopPtr::make_from_klass_raw(field->holder());
1772   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);
1773   assert((field->is_final() || field->is_stable()) == !atp->is_rewritable(), "must get the rewritable bits correct");
1774   return atp;
1775 }
1776 
1777 
1778 //------------------------------have_alias_type--------------------------------
1779 bool Compile::have_alias_type(const TypePtr* adr_type) {
1780   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1781   if (ace->_adr_type == adr_type) {
1782     return true;
1783   }
1784 
1785   // Handle special cases.
1786   if (adr_type == nullptr)             return true;
1787   if (adr_type == TypePtr::BOTTOM)  return true;
1788 
1789   return find_alias_type(adr_type, true, nullptr) != nullptr;
1790 }
1791 
1792 //-----------------------------must_alias--------------------------------------
1793 // True if all values of the given address type are in the given alias category.
1794 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
1795   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1796   if (adr_type == nullptr)              return true;  // null serves as TypePtr::TOP
1797   if (alias_idx == AliasIdxTop)         return false; // the empty category
1798   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
1799 
1800   // the only remaining possible overlap is identity
1801   int adr_idx = get_alias_index(adr_type);
1802   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1803   assert(adr_idx == alias_idx ||
1804          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
1805           && adr_type                       != TypeOopPtr::BOTTOM),
1806          "should not be testing for overlap with an unsafe pointer");
1807   return adr_idx == alias_idx;
1808 }
1809 
1810 //------------------------------can_alias--------------------------------------
1811 // True if any values of the given address type are in the given alias category.
1812 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
1813   if (alias_idx == AliasIdxTop)         return false; // the empty category
1814   if (adr_type == nullptr)              return false; // null serves as TypePtr::TOP
1815   // Known instance doesn't alias with bottom memory
1816   if (alias_idx == AliasIdxBot)         return !adr_type->is_known_instance();                   // the universal category
1817   if (adr_type->base() == Type::AnyPtr) return !C->get_adr_type(alias_idx)->is_known_instance(); // TypePtr::BOTTOM or its twins
1818 
1819   // the only remaining possible overlap is identity
1820   int adr_idx = get_alias_index(adr_type);
1821   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1822   return adr_idx == alias_idx;
1823 }
1824 
1825 // Mark all ParsePredicateNodes as useless. They will later be removed from the graph in IGVN together with their
1826 // uncommon traps if no Runtime Predicates were created from the Parse Predicates.
1827 void Compile::mark_parse_predicate_nodes_useless(PhaseIterGVN& igvn) {
1828   if (parse_predicate_count() == 0) {
1829     return;
1830   }
1831   for (int i = 0; i < parse_predicate_count(); i++) {
1832     ParsePredicateNode* parse_predicate = _parse_predicates.at(i);
1833     parse_predicate->mark_useless(igvn);
1834   }
1835   _parse_predicates.clear();
1836 }
1837 
1838 void Compile::record_for_post_loop_opts_igvn(Node* n) {
1839   if (!n->for_post_loop_opts_igvn()) {
1840     assert(!_for_post_loop_igvn.contains(n), "duplicate");
1841     n->add_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
1842     _for_post_loop_igvn.append(n);
1843   }
1844 }
1845 
1846 void Compile::remove_from_post_loop_opts_igvn(Node* n) {
1847   n->remove_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
1848   _for_post_loop_igvn.remove(n);
1849 }
1850 
1851 void Compile::process_for_post_loop_opts_igvn(PhaseIterGVN& igvn) {
1852   // Verify that all previous optimizations produced a valid graph
1853   // at least to this point, even if no loop optimizations were done.
1854   PhaseIdealLoop::verify(igvn);
1855 
1856   if (_print_phase_loop_opts) {
1857     print_method(PHASE_AFTER_LOOP_OPTS, 2);
1858   }
1859   C->set_post_loop_opts_phase(); // no more loop opts allowed
1860 
1861   assert(!C->major_progress(), "not cleared");
1862 
1863   if (_for_post_loop_igvn.length() > 0) {
1864     while (_for_post_loop_igvn.length() > 0) {
1865       Node* n = _for_post_loop_igvn.pop();
1866       n->remove_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
1867       igvn._worklist.push(n);
1868     }
1869     igvn.optimize();
1870     if (failing()) return;
1871     assert(_for_post_loop_igvn.length() == 0, "no more delayed nodes allowed");
1872     assert(C->parse_predicate_count() == 0, "all parse predicates should have been removed now");
1873 
1874     // Sometimes IGVN sets major progress (e.g., when processing loop nodes).
1875     if (C->major_progress()) {
1876       C->clear_major_progress(); // ensure that major progress is now clear
1877     }
1878   }
1879 }
1880 
1881 void Compile::record_for_merge_stores_igvn(Node* n) {
1882   if (!n->for_merge_stores_igvn()) {
1883     assert(!_for_merge_stores_igvn.contains(n), "duplicate");
1884     n->add_flag(Node::NodeFlags::Flag_for_merge_stores_igvn);
1885     _for_merge_stores_igvn.append(n);
1886   }
1887 }
1888 
1889 void Compile::remove_from_merge_stores_igvn(Node* n) {
1890   n->remove_flag(Node::NodeFlags::Flag_for_merge_stores_igvn);
1891   _for_merge_stores_igvn.remove(n);
1892 }
1893 
1894 // We need to wait with merging stores until RangeCheck smearing has removed the RangeChecks during
1895 // the post loops IGVN phase. If we do it earlier, then there may still be some RangeChecks between
1896 // the stores, and we merge the wrong sequence of stores.
1897 // Example:
1898 //   StoreI RangeCheck StoreI StoreI RangeCheck StoreI
1899 // Apply MergeStores:
1900 //   StoreI RangeCheck [   StoreL  ] RangeCheck StoreI
1901 // Remove more RangeChecks:
1902 //   StoreI            [   StoreL  ]            StoreI
1903 // But now it would have been better to do this instead:
1904 //   [         StoreL       ] [       StoreL         ]
1905 //
1906 // Note: we allow stores to merge in this dedicated IGVN round, and any later IGVN round,
1907 //       since we never unset _merge_stores_phase.
1908 void Compile::process_for_merge_stores_igvn(PhaseIterGVN& igvn) {
1909   C->set_merge_stores_phase();
1910 
1911   if (_for_merge_stores_igvn.length() > 0) {
1912     while (_for_merge_stores_igvn.length() > 0) {
1913       Node* n = _for_merge_stores_igvn.pop();
1914       n->remove_flag(Node::NodeFlags::Flag_for_merge_stores_igvn);
1915       igvn._worklist.push(n);
1916     }
1917     igvn.optimize();
1918     if (failing()) return;
1919     assert(_for_merge_stores_igvn.length() == 0, "no more delayed nodes allowed");
1920     print_method(PHASE_AFTER_MERGE_STORES, 3);
1921   }
1922 }
1923 
1924 void Compile::record_unstable_if_trap(UnstableIfTrap* trap) {
1925   if (OptimizeUnstableIf) {
1926     _unstable_if_traps.append(trap);
1927   }
1928 }
1929 
1930 void Compile::remove_useless_unstable_if_traps(Unique_Node_List& useful) {
1931   for (int i = _unstable_if_traps.length() - 1; i >= 0; i--) {
1932     UnstableIfTrap* trap = _unstable_if_traps.at(i);
1933     Node* n = trap->uncommon_trap();
1934     if (!useful.member(n)) {
1935       _unstable_if_traps.delete_at(i); // replaces i-th with last element which is known to be useful (already processed)
1936     }
1937   }
1938 }
1939 
1940 // Remove the unstable if trap associated with 'unc' from candidates. It is either dead
1941 // or fold-compares case. Return true if succeed or not found.
1942 //
1943 // In rare cases, the found trap has been processed. It is too late to delete it. Return
1944 // false and ask fold-compares to yield.
1945 //
1946 // 'fold-compares' may use the uncommon_trap of the dominating IfNode to cover the fused
1947 // IfNode. This breaks the unstable_if trap invariant: control takes the unstable path
1948 // when deoptimization does happen.
1949 bool Compile::remove_unstable_if_trap(CallStaticJavaNode* unc, bool yield) {
1950   for (int i = 0; i < _unstable_if_traps.length(); ++i) {
1951     UnstableIfTrap* trap = _unstable_if_traps.at(i);
1952     if (trap->uncommon_trap() == unc) {
1953       if (yield && trap->modified()) {
1954         return false;
1955       }
1956       _unstable_if_traps.delete_at(i);
1957       break;
1958     }
1959   }
1960   return true;
1961 }
1962 
1963 // Re-calculate unstable_if traps with the liveness of next_bci, which points to the unlikely path.
1964 // It needs to be done after igvn because fold-compares may fuse uncommon_traps and before renumbering.
1965 void Compile::process_for_unstable_if_traps(PhaseIterGVN& igvn) {
1966   for (int i = _unstable_if_traps.length() - 1; i >= 0; --i) {
1967     UnstableIfTrap* trap = _unstable_if_traps.at(i);
1968     CallStaticJavaNode* unc = trap->uncommon_trap();
1969     int next_bci = trap->next_bci();
1970     bool modified = trap->modified();
1971 
1972     if (next_bci != -1 && !modified) {
1973       assert(!_dead_node_list.test(unc->_idx), "changing a dead node!");
1974       JVMState* jvms = unc->jvms();
1975       ciMethod* method = jvms->method();
1976       ciBytecodeStream iter(method);
1977 
1978       iter.force_bci(jvms->bci());
1979       assert(next_bci == iter.next_bci() || next_bci == iter.get_dest(), "wrong next_bci at unstable_if");
1980       Bytecodes::Code c = iter.cur_bc();
1981       Node* lhs = nullptr;
1982       Node* rhs = nullptr;
1983       if (c == Bytecodes::_if_acmpeq || c == Bytecodes::_if_acmpne) {
1984         lhs = unc->peek_operand(0);
1985         rhs = unc->peek_operand(1);
1986       } else if (c == Bytecodes::_ifnull || c == Bytecodes::_ifnonnull) {
1987         lhs = unc->peek_operand(0);
1988       }
1989 
1990       ResourceMark rm;
1991       const MethodLivenessResult& live_locals = method->liveness_at_bci(next_bci);
1992       assert(live_locals.is_valid(), "broken liveness info");
1993       int len = (int)live_locals.size();
1994 
1995       for (int i = 0; i < len; i++) {
1996         Node* local = unc->local(jvms, i);
1997         // kill local using the liveness of next_bci.
1998         // give up when the local looks like an operand to secure reexecution.
1999         if (!live_locals.at(i) && !local->is_top() && local != lhs && local!= rhs) {
2000           uint idx = jvms->locoff() + i;
2001 #ifdef ASSERT
2002           if (PrintOpto && Verbose) {
2003             tty->print("[unstable_if] kill local#%d: ", idx);
2004             local->dump();
2005             tty->cr();
2006           }
2007 #endif
2008           igvn.replace_input_of(unc, idx, top());
2009           modified = true;
2010         }
2011       }
2012     }
2013 
2014     // keep the mondified trap for late query
2015     if (modified) {
2016       trap->set_modified();
2017     } else {
2018       _unstable_if_traps.delete_at(i);
2019     }
2020   }
2021   igvn.optimize();
2022 }
2023 
2024 // StringOpts and late inlining of string methods
2025 void Compile::inline_string_calls(bool parse_time) {
2026   {
2027     // remove useless nodes to make the usage analysis simpler
2028     ResourceMark rm;
2029     PhaseRemoveUseless pru(initial_gvn(), *igvn_worklist());
2030   }
2031 
2032   {
2033     ResourceMark rm;
2034     print_method(PHASE_BEFORE_STRINGOPTS, 3);
2035     PhaseStringOpts pso(initial_gvn());
2036     print_method(PHASE_AFTER_STRINGOPTS, 3);
2037   }
2038 
2039   // now inline anything that we skipped the first time around
2040   if (!parse_time) {
2041     _late_inlines_pos = _late_inlines.length();
2042   }
2043 
2044   while (_string_late_inlines.length() > 0) {
2045     CallGenerator* cg = _string_late_inlines.pop();
2046     cg->do_late_inline();
2047     if (failing())  return;
2048   }
2049   _string_late_inlines.trunc_to(0);
2050 }
2051 
2052 // Late inlining of boxing methods
2053 void Compile::inline_boxing_calls(PhaseIterGVN& igvn) {
2054   if (_boxing_late_inlines.length() > 0) {
2055     assert(has_boxed_value(), "inconsistent");
2056 
2057     set_inlining_incrementally(true);
2058 
2059     igvn_worklist()->ensure_empty(); // should be done with igvn
2060 
2061     _late_inlines_pos = _late_inlines.length();
2062 
2063     while (_boxing_late_inlines.length() > 0) {
2064       CallGenerator* cg = _boxing_late_inlines.pop();
2065       cg->do_late_inline();
2066       if (failing())  return;
2067     }
2068     _boxing_late_inlines.trunc_to(0);
2069 
2070     inline_incrementally_cleanup(igvn);
2071 
2072     set_inlining_incrementally(false);
2073   }
2074 }
2075 
2076 bool Compile::inline_incrementally_one() {
2077   assert(IncrementalInline, "incremental inlining should be on");
2078   assert(_late_inlines.length() > 0, "should have been checked by caller");
2079 
2080   TracePhase tp(_t_incrInline_inline);
2081 
2082   set_inlining_progress(false);
2083   set_do_cleanup(false);
2084 
2085   for (int i = 0; i < _late_inlines.length(); i++) {
2086     _late_inlines_pos = i+1;
2087     CallGenerator* cg = _late_inlines.at(i);
2088     bool is_scheduled_for_igvn_before = C->igvn_worklist()->member(cg->call_node());
2089     bool does_dispatch = cg->is_virtual_late_inline() || cg->is_mh_late_inline();
2090     if (inlining_incrementally() || does_dispatch) { // a call can be either inlined or strength-reduced to a direct call
2091       if (should_stress_inlining()) {
2092         // randomly add repeated inline attempt if stress-inlining
2093         cg->call_node()->set_generator(cg);
2094         C->igvn_worklist()->push(cg->call_node());
2095         continue;
2096       }
2097       cg->do_late_inline();
2098       assert(_late_inlines.at(i) == cg, "no insertions before current position allowed");
2099       if (failing()) {
2100         return false;
2101       } else if (inlining_progress()) {
2102         _late_inlines_pos = i+1; // restore the position in case new elements were inserted
2103         print_method(PHASE_INCREMENTAL_INLINE_STEP, 3, cg->call_node());
2104         break; // process one call site at a time
2105       } else {
2106         bool is_scheduled_for_igvn_after = C->igvn_worklist()->member(cg->call_node());
2107         if (!is_scheduled_for_igvn_before && is_scheduled_for_igvn_after) {
2108           // Avoid potential infinite loop if node already in the IGVN list
2109           assert(false, "scheduled for IGVN during inlining attempt");
2110         } else {
2111           // Ensure call node has not disappeared from IGVN worklist during a failed inlining attempt
2112           assert(!is_scheduled_for_igvn_before || is_scheduled_for_igvn_after, "call node removed from IGVN list during inlining pass");
2113           cg->call_node()->set_generator(cg);
2114         }
2115       }
2116     } else {
2117       // Ignore late inline direct calls when inlining is not allowed.
2118       // They are left in the late inline list when node budget is exhausted until the list is fully drained.
2119     }
2120   }
2121   // Remove processed elements.
2122   _late_inlines.remove_till(_late_inlines_pos);
2123   _late_inlines_pos = 0;
2124 
2125   assert(inlining_progress() || _late_inlines.length() == 0, "no progress");
2126 
2127   bool needs_cleanup = do_cleanup() || over_inlining_cutoff();
2128 
2129   set_inlining_progress(false);
2130   set_do_cleanup(false);
2131 
2132   bool force_cleanup = directive()->IncrementalInlineForceCleanupOption;
2133   return (_late_inlines.length() > 0) && !needs_cleanup && !force_cleanup;
2134 }
2135 
2136 void Compile::inline_incrementally_cleanup(PhaseIterGVN& igvn) {
2137   {
2138     TracePhase tp(_t_incrInline_pru);
2139     ResourceMark rm;
2140     PhaseRemoveUseless pru(initial_gvn(), *igvn_worklist());
2141   }
2142   {
2143     TracePhase tp(_t_incrInline_igvn);
2144     igvn.reset();
2145     igvn.optimize();
2146     if (failing()) return;
2147   }
2148   print_method(PHASE_INCREMENTAL_INLINE_CLEANUP, 3);
2149 }
2150 
2151 template<typename E>
2152 static void shuffle_array(Compile& C, GrowableArray<E>& array) {
2153   if (array.length() < 2) {
2154     return;
2155   }
2156   for (uint i = array.length() - 1; i >= 1; i--) {
2157     uint j = C.random() % (i + 1);
2158     swap(array.at(i), array.at(j));
2159   }
2160 }
2161 
2162 void Compile::shuffle_late_inlines() {
2163   shuffle_array(*C, _late_inlines);
2164 }
2165 
2166 // Perform incremental inlining until bound on number of live nodes is reached
2167 void Compile::inline_incrementally(PhaseIterGVN& igvn) {
2168   TracePhase tp(_t_incrInline);
2169 
2170   set_inlining_incrementally(true);
2171   uint low_live_nodes = 0;
2172 
2173   if (StressIncrementalInlining) {
2174     shuffle_late_inlines();
2175   }
2176 
2177   while (_late_inlines.length() > 0) {
2178     if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2179       if (low_live_nodes < (uint)LiveNodeCountInliningCutoff * 8 / 10) {
2180         TracePhase tp(_t_incrInline_ideal);
2181         // PhaseIdealLoop is expensive so we only try it once we are
2182         // out of live nodes and we only try it again if the previous
2183         // helped got the number of nodes down significantly
2184         PhaseIdealLoop::optimize(igvn, LoopOptsNone);
2185         if (failing())  return;
2186         low_live_nodes = live_nodes();
2187         _major_progress = true;
2188       }
2189 
2190       if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2191         bool do_print_inlining = print_inlining() || print_intrinsics();
2192         if (do_print_inlining || log() != nullptr) {
2193           // Print inlining message for candidates that we couldn't inline for lack of space.
2194           for (int i = 0; i < _late_inlines.length(); i++) {
2195             CallGenerator* cg = _late_inlines.at(i);
2196             const char* msg = "live nodes > LiveNodeCountInliningCutoff";
2197             if (do_print_inlining) {
2198               inline_printer()->record(cg->method(), cg->call_node()->jvms(), InliningResult::FAILURE, msg);
2199             }
2200             log_late_inline_failure(cg, msg);
2201           }
2202         }
2203         break; // finish
2204       }
2205     }
2206 
2207     igvn_worklist()->ensure_empty(); // should be done with igvn
2208 
2209     if (_late_inlines.length() == 0) {
2210       break; // no more progress
2211     }
2212 
2213     while (inline_incrementally_one()) {
2214       assert(!failing_internal() || failure_is_artificial(), "inconsistent");
2215     }
2216     if (failing())  return;
2217 
2218     inline_incrementally_cleanup(igvn);
2219 
2220     print_method(PHASE_INCREMENTAL_INLINE_STEP, 3);
2221 
2222     if (failing())  return;
2223   }
2224 
2225   igvn_worklist()->ensure_empty(); // should be done with igvn
2226 
2227   if (_string_late_inlines.length() > 0) {
2228     assert(has_stringbuilder(), "inconsistent");
2229 
2230     inline_string_calls(false);
2231 
2232     if (failing())  return;
2233 
2234     inline_incrementally_cleanup(igvn);
2235   }
2236 
2237   set_inlining_incrementally(false);
2238 }
2239 
2240 void Compile::process_late_inline_calls_no_inline(PhaseIterGVN& igvn) {
2241   // "inlining_incrementally() == false" is used to signal that no inlining is allowed
2242   // (see LateInlineVirtualCallGenerator::do_late_inline_check() for details).
2243   // Tracking and verification of modified nodes is disabled by setting "_modified_nodes == nullptr"
2244   // as if "inlining_incrementally() == true" were set.
2245   assert(inlining_incrementally() == false, "not allowed");
2246   assert(_modified_nodes == nullptr, "not allowed");
2247   assert(_late_inlines.length() > 0, "sanity");
2248 
2249   if (StressIncrementalInlining) {
2250     shuffle_late_inlines();
2251   }
2252 
2253   while (_late_inlines.length() > 0) {
2254     igvn_worklist()->ensure_empty(); // should be done with igvn
2255 
2256     while (inline_incrementally_one()) {
2257       assert(!failing_internal() || failure_is_artificial(), "inconsistent");
2258     }
2259     if (failing())  return;
2260 
2261     inline_incrementally_cleanup(igvn);
2262   }
2263 }
2264 
2265 bool Compile::optimize_loops(PhaseIterGVN& igvn, LoopOptsMode mode) {
2266   if (_loop_opts_cnt > 0) {
2267     while (major_progress() && (_loop_opts_cnt > 0)) {
2268       TracePhase tp(_t_idealLoop);
2269       PhaseIdealLoop::optimize(igvn, mode);
2270       _loop_opts_cnt--;
2271       if (failing())  return false;
2272       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
2273     }
2274   }
2275   return true;
2276 }
2277 
2278 // Remove edges from "root" to each SafePoint at a backward branch.
2279 // They were inserted during parsing (see add_safepoint()) to make
2280 // infinite loops without calls or exceptions visible to root, i.e.,
2281 // useful.
2282 void Compile::remove_root_to_sfpts_edges(PhaseIterGVN& igvn) {
2283   Node *r = root();
2284   if (r != nullptr) {
2285     for (uint i = r->req(); i < r->len(); ++i) {
2286       Node *n = r->in(i);
2287       if (n != nullptr && n->is_SafePoint()) {
2288         r->rm_prec(i);
2289         if (n->outcnt() == 0) {
2290           igvn.remove_dead_node(n);
2291         }
2292         --i;
2293       }
2294     }
2295     // Parsing may have added top inputs to the root node (Path
2296     // leading to the Halt node proven dead). Make sure we get a
2297     // chance to clean them up.
2298     igvn._worklist.push(r);
2299     igvn.optimize();
2300   }
2301 }
2302 
2303 //------------------------------Optimize---------------------------------------
2304 // Given a graph, optimize it.
2305 void Compile::Optimize() {
2306   TracePhase tp(_t_optimizer);
2307 
2308 #ifndef PRODUCT
2309   if (env()->break_at_compile()) {
2310     BREAKPOINT;
2311   }
2312 
2313 #endif
2314 
2315   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
2316 #ifdef ASSERT
2317   bs->verify_gc_barriers(this, BarrierSetC2::BeforeOptimize);
2318 #endif
2319 
2320   ResourceMark rm;
2321 
2322   NOT_PRODUCT( verify_graph_edges(); )
2323 
2324   print_method(PHASE_AFTER_PARSING, 1);
2325 
2326  {
2327   // Iterative Global Value Numbering, including ideal transforms
2328   PhaseIterGVN igvn;
2329 #ifdef ASSERT
2330   _modified_nodes = new (comp_arena()) Unique_Node_List(comp_arena());
2331 #endif
2332   {
2333     TracePhase tp(_t_iterGVN);
2334     igvn.optimize();
2335   }
2336 
2337   if (failing())  return;
2338 
2339   print_method(PHASE_ITER_GVN1, 2);
2340 
2341   process_for_unstable_if_traps(igvn);
2342 
2343   if (failing())  return;
2344 
2345   inline_incrementally(igvn);
2346 
2347   print_method(PHASE_INCREMENTAL_INLINE, 2);
2348 
2349   if (failing())  return;
2350 
2351   if (eliminate_boxing()) {
2352     // Inline valueOf() methods now.
2353     inline_boxing_calls(igvn);
2354 
2355     if (failing())  return;
2356 
2357     if (AlwaysIncrementalInline || StressIncrementalInlining) {
2358       inline_incrementally(igvn);
2359     }
2360 
2361     print_method(PHASE_INCREMENTAL_BOXING_INLINE, 2);
2362 
2363     if (failing())  return;
2364   }
2365 
2366   // Remove the speculative part of types and clean up the graph from
2367   // the extra CastPP nodes whose only purpose is to carry them. Do
2368   // that early so that optimizations are not disrupted by the extra
2369   // CastPP nodes.
2370   remove_speculative_types(igvn);
2371 
2372   if (failing())  return;
2373 
2374   // No more new expensive nodes will be added to the list from here
2375   // so keep only the actual candidates for optimizations.
2376   cleanup_expensive_nodes(igvn);
2377 
2378   if (failing())  return;
2379 
2380   assert(EnableVectorSupport || !has_vbox_nodes(), "sanity");
2381   if (EnableVectorSupport && has_vbox_nodes()) {
2382     TracePhase tp(_t_vector);
2383     PhaseVector pv(igvn);
2384     pv.optimize_vector_boxes();
2385     if (failing())  return;
2386     print_method(PHASE_ITER_GVN_AFTER_VECTOR, 2);
2387   }
2388   assert(!has_vbox_nodes(), "sanity");
2389 
2390   if (!failing() && RenumberLiveNodes && live_nodes() + NodeLimitFudgeFactor < unique()) {
2391     Compile::TracePhase tp(_t_renumberLive);
2392     igvn_worklist()->ensure_empty(); // should be done with igvn
2393     {
2394       ResourceMark rm;
2395       PhaseRenumberLive prl(initial_gvn(), *igvn_worklist());
2396     }
2397     igvn.reset();
2398     igvn.optimize();
2399     if (failing()) return;
2400   }
2401 
2402   // Now that all inlining is over and no PhaseRemoveUseless will run, cut edge from root to loop
2403   // safepoints
2404   remove_root_to_sfpts_edges(igvn);
2405 
2406   if (failing())  return;
2407 
2408   _print_phase_loop_opts = has_loops();
2409   if (_print_phase_loop_opts) {
2410     print_method(PHASE_BEFORE_LOOP_OPTS, 2);
2411   }
2412 
2413   // Perform escape analysis
2414   if (do_escape_analysis() && ConnectionGraph::has_candidates(this)) {
2415     if (has_loops()) {
2416       // Cleanup graph (remove dead nodes).
2417       TracePhase tp(_t_idealLoop);
2418       PhaseIdealLoop::optimize(igvn, LoopOptsMaxUnroll);
2419       if (failing())  return;
2420     }
2421     bool progress;
2422     print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
2423     do {
2424       ConnectionGraph::do_analysis(this, &igvn);
2425 
2426       if (failing())  return;
2427 
2428       int mcount = macro_count(); // Record number of allocations and locks before IGVN
2429 
2430       // Optimize out fields loads from scalar replaceable allocations.
2431       igvn.optimize();
2432       print_method(PHASE_ITER_GVN_AFTER_EA, 2);
2433 
2434       if (failing()) return;
2435 
2436       if (congraph() != nullptr && macro_count() > 0) {
2437         TracePhase tp(_t_macroEliminate);
2438         PhaseMacroExpand mexp(igvn);
2439         mexp.eliminate_macro_nodes();
2440         if (failing()) return;
2441         print_method(PHASE_AFTER_MACRO_ELIMINATION, 2);
2442 
2443         igvn.set_delay_transform(false);
2444         igvn.optimize();
2445         if (failing()) return;
2446 
2447         print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
2448       }
2449 
2450       ConnectionGraph::verify_ram_nodes(this, root());
2451       if (failing())  return;
2452 
2453       progress = do_iterative_escape_analysis() &&
2454                  (macro_count() < mcount) &&
2455                  ConnectionGraph::has_candidates(this);
2456       // Try again if candidates exist and made progress
2457       // by removing some allocations and/or locks.
2458     } while (progress);
2459   }
2460 
2461   // Loop transforms on the ideal graph.  Range Check Elimination,
2462   // peeling, unrolling, etc.
2463 
2464   // Set loop opts counter
2465   if((_loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
2466     {
2467       TracePhase tp(_t_idealLoop);
2468       PhaseIdealLoop::optimize(igvn, LoopOptsDefault);
2469       _loop_opts_cnt--;
2470       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP1, 2);
2471       if (failing())  return;
2472     }
2473     // Loop opts pass if partial peeling occurred in previous pass
2474     if(PartialPeelLoop && major_progress() && (_loop_opts_cnt > 0)) {
2475       TracePhase tp(_t_idealLoop);
2476       PhaseIdealLoop::optimize(igvn, LoopOptsSkipSplitIf);
2477       _loop_opts_cnt--;
2478       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP2, 2);
2479       if (failing())  return;
2480     }
2481     // Loop opts pass for loop-unrolling before CCP
2482     if(major_progress() && (_loop_opts_cnt > 0)) {
2483       TracePhase tp(_t_idealLoop);
2484       PhaseIdealLoop::optimize(igvn, LoopOptsSkipSplitIf);
2485       _loop_opts_cnt--;
2486       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP3, 2);
2487     }
2488     if (!failing()) {
2489       // Verify that last round of loop opts produced a valid graph
2490       PhaseIdealLoop::verify(igvn);
2491     }
2492   }
2493   if (failing())  return;
2494 
2495   // Conditional Constant Propagation;
2496   print_method(PHASE_BEFORE_CCP1, 2);
2497   PhaseCCP ccp( &igvn );
2498   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
2499   {
2500     TracePhase tp(_t_ccp);
2501     ccp.do_transform();
2502   }
2503   print_method(PHASE_CCP1, 2);
2504 
2505   assert( true, "Break here to ccp.dump_old2new_map()");
2506 
2507   // Iterative Global Value Numbering, including ideal transforms
2508   {
2509     TracePhase tp(_t_iterGVN2);
2510     igvn.reset_from_igvn(&ccp);
2511     igvn.optimize();
2512   }
2513   print_method(PHASE_ITER_GVN2, 2);
2514 
2515   if (failing())  return;
2516 
2517   // Loop transforms on the ideal graph.  Range Check Elimination,
2518   // peeling, unrolling, etc.
2519   if (!optimize_loops(igvn, LoopOptsDefault)) {
2520     return;
2521   }
2522 
2523   if (failing())  return;
2524 
2525   C->clear_major_progress(); // ensure that major progress is now clear
2526 
2527   process_for_post_loop_opts_igvn(igvn);
2528 
2529   process_for_merge_stores_igvn(igvn);
2530 
2531   if (failing())  return;
2532 
2533 #ifdef ASSERT
2534   bs->verify_gc_barriers(this, BarrierSetC2::BeforeMacroExpand);
2535 #endif
2536 
2537   {
2538     TracePhase tp(_t_macroExpand);
2539     print_method(PHASE_BEFORE_MACRO_EXPANSION, 3);
2540     PhaseMacroExpand  mex(igvn);
2541     // Do not allow new macro nodes once we start to eliminate and expand
2542     C->reset_allow_macro_nodes();
2543     // Last attempt to eliminate macro nodes before expand
2544     mex.eliminate_macro_nodes();
2545     if (failing()) {
2546       return;
2547     }
2548     mex.eliminate_opaque_looplimit_macro_nodes();
2549     if (failing()) {
2550       return;
2551     }
2552     print_method(PHASE_AFTER_MACRO_ELIMINATION, 2);
2553     if (mex.expand_macro_nodes()) {
2554       assert(failing(), "must bail out w/ explicit message");
2555       return;
2556     }
2557     print_method(PHASE_AFTER_MACRO_EXPANSION, 2);
2558   }
2559 
2560   {
2561     TracePhase tp(_t_barrierExpand);
2562     if (bs->expand_barriers(this, igvn)) {
2563       assert(failing(), "must bail out w/ explicit message");
2564       return;
2565     }
2566     print_method(PHASE_BARRIER_EXPANSION, 2);
2567   }
2568 
2569   if (C->max_vector_size() > 0) {
2570     C->optimize_logic_cones(igvn);
2571     igvn.optimize();
2572     if (failing()) return;
2573   }
2574 
2575   DEBUG_ONLY( _modified_nodes = nullptr; )
2576 
2577   assert(igvn._worklist.size() == 0, "not empty");
2578 
2579   assert(_late_inlines.length() == 0 || IncrementalInlineMH || IncrementalInlineVirtual, "not empty");
2580 
2581   if (_late_inlines.length() > 0) {
2582     // More opportunities to optimize virtual and MH calls.
2583     // Though it's maybe too late to perform inlining, strength-reducing them to direct calls is still an option.
2584     process_late_inline_calls_no_inline(igvn);
2585     if (failing())  return;
2586   }
2587  } // (End scope of igvn; run destructor if necessary for asserts.)
2588 
2589  check_no_dead_use();
2590 
2591  // We will never use the NodeHash table any more. Clear it so that final_graph_reshaping does not have
2592  // to remove hashes to unlock nodes for modifications.
2593  C->node_hash()->clear();
2594 
2595  // A method with only infinite loops has no edges entering loops from root
2596  {
2597    TracePhase tp(_t_graphReshaping);
2598    if (final_graph_reshaping()) {
2599      assert(failing(), "must bail out w/ explicit message");
2600      return;
2601    }
2602  }
2603 
2604  print_method(PHASE_OPTIMIZE_FINISHED, 2);
2605  DEBUG_ONLY(set_phase_optimize_finished();)
2606 }
2607 
2608 #ifdef ASSERT
2609 void Compile::check_no_dead_use() const {
2610   ResourceMark rm;
2611   Unique_Node_List wq;
2612   wq.push(root());
2613   for (uint i = 0; i < wq.size(); ++i) {
2614     Node* n = wq.at(i);
2615     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
2616       Node* u = n->fast_out(j);
2617       if (u->outcnt() == 0 && !u->is_Con()) {
2618         u->dump();
2619         fatal("no reachable node should have no use");
2620       }
2621       wq.push(u);
2622     }
2623   }
2624 }
2625 #endif
2626 
2627 void Compile::inline_vector_reboxing_calls() {
2628   if (C->_vector_reboxing_late_inlines.length() > 0) {
2629     _late_inlines_pos = C->_late_inlines.length();
2630     while (_vector_reboxing_late_inlines.length() > 0) {
2631       CallGenerator* cg = _vector_reboxing_late_inlines.pop();
2632       cg->do_late_inline();
2633       if (failing())  return;
2634       print_method(PHASE_INLINE_VECTOR_REBOX, 3, cg->call_node());
2635     }
2636     _vector_reboxing_late_inlines.trunc_to(0);
2637   }
2638 }
2639 
2640 bool Compile::has_vbox_nodes() {
2641   if (C->_vector_reboxing_late_inlines.length() > 0) {
2642     return true;
2643   }
2644   for (int macro_idx = C->macro_count() - 1; macro_idx >= 0; macro_idx--) {
2645     Node * n = C->macro_node(macro_idx);
2646     assert(n->is_macro(), "only macro nodes expected here");
2647     if (n->Opcode() == Op_VectorUnbox || n->Opcode() == Op_VectorBox || n->Opcode() == Op_VectorBoxAllocate) {
2648       return true;
2649     }
2650   }
2651   return false;
2652 }
2653 
2654 //---------------------------- Bitwise operation packing optimization ---------------------------
2655 
2656 static bool is_vector_unary_bitwise_op(Node* n) {
2657   return n->Opcode() == Op_XorV &&
2658          VectorNode::is_vector_bitwise_not_pattern(n);
2659 }
2660 
2661 static bool is_vector_binary_bitwise_op(Node* n) {
2662   switch (n->Opcode()) {
2663     case Op_AndV:
2664     case Op_OrV:
2665       return true;
2666 
2667     case Op_XorV:
2668       return !is_vector_unary_bitwise_op(n);
2669 
2670     default:
2671       return false;
2672   }
2673 }
2674 
2675 static bool is_vector_ternary_bitwise_op(Node* n) {
2676   return n->Opcode() == Op_MacroLogicV;
2677 }
2678 
2679 static bool is_vector_bitwise_op(Node* n) {
2680   return is_vector_unary_bitwise_op(n)  ||
2681          is_vector_binary_bitwise_op(n) ||
2682          is_vector_ternary_bitwise_op(n);
2683 }
2684 
2685 static bool is_vector_bitwise_cone_root(Node* n) {
2686   if (n->bottom_type()->isa_vectmask() || !is_vector_bitwise_op(n)) {
2687     return false;
2688   }
2689   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2690     if (is_vector_bitwise_op(n->fast_out(i))) {
2691       return false;
2692     }
2693   }
2694   return true;
2695 }
2696 
2697 static uint collect_unique_inputs(Node* n, Unique_Node_List& inputs) {
2698   uint cnt = 0;
2699   if (is_vector_bitwise_op(n)) {
2700     uint inp_cnt = n->is_predicated_vector() ? n->req()-1 : n->req();
2701     if (VectorNode::is_vector_bitwise_not_pattern(n)) {
2702       for (uint i = 1; i < inp_cnt; i++) {
2703         Node* in = n->in(i);
2704         bool skip = VectorNode::is_all_ones_vector(in);
2705         if (!skip && !inputs.member(in)) {
2706           inputs.push(in);
2707           cnt++;
2708         }
2709       }
2710       assert(cnt <= 1, "not unary");
2711     } else {
2712       uint last_req = inp_cnt;
2713       if (is_vector_ternary_bitwise_op(n)) {
2714         last_req = inp_cnt - 1; // skip last input
2715       }
2716       for (uint i = 1; i < last_req; i++) {
2717         Node* def = n->in(i);
2718         if (!inputs.member(def)) {
2719           inputs.push(def);
2720           cnt++;
2721         }
2722       }
2723     }
2724   } else { // not a bitwise operations
2725     if (!inputs.member(n)) {
2726       inputs.push(n);
2727       cnt++;
2728     }
2729   }
2730   return cnt;
2731 }
2732 
2733 void Compile::collect_logic_cone_roots(Unique_Node_List& list) {
2734   Unique_Node_List useful_nodes;
2735   C->identify_useful_nodes(useful_nodes);
2736 
2737   for (uint i = 0; i < useful_nodes.size(); i++) {
2738     Node* n = useful_nodes.at(i);
2739     if (is_vector_bitwise_cone_root(n)) {
2740       list.push(n);
2741     }
2742   }
2743 }
2744 
2745 Node* Compile::xform_to_MacroLogicV(PhaseIterGVN& igvn,
2746                                     const TypeVect* vt,
2747                                     Unique_Node_List& partition,
2748                                     Unique_Node_List& inputs) {
2749   assert(partition.size() == 2 || partition.size() == 3, "not supported");
2750   assert(inputs.size()    == 2 || inputs.size()    == 3, "not supported");
2751   assert(Matcher::match_rule_supported_vector(Op_MacroLogicV, vt->length(), vt->element_basic_type()), "not supported");
2752 
2753   Node* in1 = inputs.at(0);
2754   Node* in2 = inputs.at(1);
2755   Node* in3 = (inputs.size() == 3 ? inputs.at(2) : in2);
2756 
2757   uint func = compute_truth_table(partition, inputs);
2758 
2759   Node* pn = partition.at(partition.size() - 1);
2760   Node* mask = pn->is_predicated_vector() ? pn->in(pn->req()-1) : nullptr;
2761   return igvn.transform(MacroLogicVNode::make(igvn, in1, in2, in3, mask, func, vt));
2762 }
2763 
2764 static uint extract_bit(uint func, uint pos) {
2765   return (func & (1 << pos)) >> pos;
2766 }
2767 
2768 //
2769 //  A macro logic node represents a truth table. It has 4 inputs,
2770 //  First three inputs corresponds to 3 columns of a truth table
2771 //  and fourth input captures the logic function.
2772 //
2773 //  eg.  fn = (in1 AND in2) OR in3;
2774 //
2775 //      MacroNode(in1,in2,in3,fn)
2776 //
2777 //  -----------------
2778 //  in1 in2 in3  fn
2779 //  -----------------
2780 //  0    0   0    0
2781 //  0    0   1    1
2782 //  0    1   0    0
2783 //  0    1   1    1
2784 //  1    0   0    0
2785 //  1    0   1    1
2786 //  1    1   0    1
2787 //  1    1   1    1
2788 //
2789 
2790 uint Compile::eval_macro_logic_op(uint func, uint in1 , uint in2, uint in3) {
2791   int res = 0;
2792   for (int i = 0; i < 8; i++) {
2793     int bit1 = extract_bit(in1, i);
2794     int bit2 = extract_bit(in2, i);
2795     int bit3 = extract_bit(in3, i);
2796 
2797     int func_bit_pos = (bit1 << 2 | bit2 << 1 | bit3);
2798     int func_bit = extract_bit(func, func_bit_pos);
2799 
2800     res |= func_bit << i;
2801   }
2802   return res;
2803 }
2804 
2805 static uint eval_operand(Node* n, HashTable<Node*,uint>& eval_map) {
2806   assert(n != nullptr, "");
2807   assert(eval_map.contains(n), "absent");
2808   return *(eval_map.get(n));
2809 }
2810 
2811 static void eval_operands(Node* n,
2812                           uint& func1, uint& func2, uint& func3,
2813                           HashTable<Node*,uint>& eval_map) {
2814   assert(is_vector_bitwise_op(n), "");
2815 
2816   if (is_vector_unary_bitwise_op(n)) {
2817     Node* opnd = n->in(1);
2818     if (VectorNode::is_vector_bitwise_not_pattern(n) && VectorNode::is_all_ones_vector(opnd)) {
2819       opnd = n->in(2);
2820     }
2821     func1 = eval_operand(opnd, eval_map);
2822   } else if (is_vector_binary_bitwise_op(n)) {
2823     func1 = eval_operand(n->in(1), eval_map);
2824     func2 = eval_operand(n->in(2), eval_map);
2825   } else {
2826     assert(is_vector_ternary_bitwise_op(n), "unknown operation");
2827     func1 = eval_operand(n->in(1), eval_map);
2828     func2 = eval_operand(n->in(2), eval_map);
2829     func3 = eval_operand(n->in(3), eval_map);
2830   }
2831 }
2832 
2833 uint Compile::compute_truth_table(Unique_Node_List& partition, Unique_Node_List& inputs) {
2834   assert(inputs.size() <= 3, "sanity");
2835   ResourceMark rm;
2836   uint res = 0;
2837   HashTable<Node*,uint> eval_map;
2838 
2839   // Populate precomputed functions for inputs.
2840   // Each input corresponds to one column of 3 input truth-table.
2841   uint input_funcs[] = { 0xAA,   // (_, _, c) -> c
2842                          0xCC,   // (_, b, _) -> b
2843                          0xF0 }; // (a, _, _) -> a
2844   for (uint i = 0; i < inputs.size(); i++) {
2845     eval_map.put(inputs.at(i), input_funcs[2-i]);
2846   }
2847 
2848   for (uint i = 0; i < partition.size(); i++) {
2849     Node* n = partition.at(i);
2850 
2851     uint func1 = 0, func2 = 0, func3 = 0;
2852     eval_operands(n, func1, func2, func3, eval_map);
2853 
2854     switch (n->Opcode()) {
2855       case Op_OrV:
2856         assert(func3 == 0, "not binary");
2857         res = func1 | func2;
2858         break;
2859       case Op_AndV:
2860         assert(func3 == 0, "not binary");
2861         res = func1 & func2;
2862         break;
2863       case Op_XorV:
2864         if (VectorNode::is_vector_bitwise_not_pattern(n)) {
2865           assert(func2 == 0 && func3 == 0, "not unary");
2866           res = (~func1) & 0xFF;
2867         } else {
2868           assert(func3 == 0, "not binary");
2869           res = func1 ^ func2;
2870         }
2871         break;
2872       case Op_MacroLogicV:
2873         // Ordering of inputs may change during evaluation of sub-tree
2874         // containing MacroLogic node as a child node, thus a re-evaluation
2875         // makes sure that function is evaluated in context of current
2876         // inputs.
2877         res = eval_macro_logic_op(n->in(4)->get_int(), func1, func2, func3);
2878         break;
2879 
2880       default: assert(false, "not supported: %s", n->Name());
2881     }
2882     assert(res <= 0xFF, "invalid");
2883     eval_map.put(n, res);
2884   }
2885   return res;
2886 }
2887 
2888 // Criteria under which nodes gets packed into a macro logic node:-
2889 //  1) Parent and both child nodes are all unmasked or masked with
2890 //     same predicates.
2891 //  2) Masked parent can be packed with left child if it is predicated
2892 //     and both have same predicates.
2893 //  3) Masked parent can be packed with right child if its un-predicated
2894 //     or has matching predication condition.
2895 //  4) An unmasked parent can be packed with an unmasked child.
2896 bool Compile::compute_logic_cone(Node* n, Unique_Node_List& partition, Unique_Node_List& inputs) {
2897   assert(partition.size() == 0, "not empty");
2898   assert(inputs.size() == 0, "not empty");
2899   if (is_vector_ternary_bitwise_op(n)) {
2900     return false;
2901   }
2902 
2903   bool is_unary_op = is_vector_unary_bitwise_op(n);
2904   if (is_unary_op) {
2905     assert(collect_unique_inputs(n, inputs) == 1, "not unary");
2906     return false; // too few inputs
2907   }
2908 
2909   bool pack_left_child = true;
2910   bool pack_right_child = true;
2911 
2912   bool left_child_LOP = is_vector_bitwise_op(n->in(1));
2913   bool right_child_LOP = is_vector_bitwise_op(n->in(2));
2914 
2915   int left_child_input_cnt = 0;
2916   int right_child_input_cnt = 0;
2917 
2918   bool parent_is_predicated = n->is_predicated_vector();
2919   bool left_child_predicated = n->in(1)->is_predicated_vector();
2920   bool right_child_predicated = n->in(2)->is_predicated_vector();
2921 
2922   Node* parent_pred = parent_is_predicated ? n->in(n->req()-1) : nullptr;
2923   Node* left_child_pred = left_child_predicated ? n->in(1)->in(n->in(1)->req()-1) : nullptr;
2924   Node* right_child_pred = right_child_predicated ? n->in(1)->in(n->in(1)->req()-1) : nullptr;
2925 
2926   do {
2927     if (pack_left_child && left_child_LOP &&
2928         ((!parent_is_predicated && !left_child_predicated) ||
2929         ((parent_is_predicated && left_child_predicated &&
2930           parent_pred == left_child_pred)))) {
2931        partition.push(n->in(1));
2932        left_child_input_cnt = collect_unique_inputs(n->in(1), inputs);
2933     } else {
2934        inputs.push(n->in(1));
2935        left_child_input_cnt = 1;
2936     }
2937 
2938     if (pack_right_child && right_child_LOP &&
2939         (!right_child_predicated ||
2940          (right_child_predicated && parent_is_predicated &&
2941           parent_pred == right_child_pred))) {
2942        partition.push(n->in(2));
2943        right_child_input_cnt = collect_unique_inputs(n->in(2), inputs);
2944     } else {
2945        inputs.push(n->in(2));
2946        right_child_input_cnt = 1;
2947     }
2948 
2949     if (inputs.size() > 3) {
2950       assert(partition.size() > 0, "");
2951       inputs.clear();
2952       partition.clear();
2953       if (left_child_input_cnt > right_child_input_cnt) {
2954         pack_left_child = false;
2955       } else {
2956         pack_right_child = false;
2957       }
2958     } else {
2959       break;
2960     }
2961   } while(true);
2962 
2963   if(partition.size()) {
2964     partition.push(n);
2965   }
2966 
2967   return (partition.size() == 2 || partition.size() == 3) &&
2968          (inputs.size()    == 2 || inputs.size()    == 3);
2969 }
2970 
2971 void Compile::process_logic_cone_root(PhaseIterGVN &igvn, Node *n, VectorSet &visited) {
2972   assert(is_vector_bitwise_op(n), "not a root");
2973 
2974   visited.set(n->_idx);
2975 
2976   // 1) Do a DFS walk over the logic cone.
2977   for (uint i = 1; i < n->req(); i++) {
2978     Node* in = n->in(i);
2979     if (!visited.test(in->_idx) && is_vector_bitwise_op(in)) {
2980       process_logic_cone_root(igvn, in, visited);
2981     }
2982   }
2983 
2984   // 2) Bottom up traversal: Merge node[s] with
2985   // the parent to form macro logic node.
2986   Unique_Node_List partition;
2987   Unique_Node_List inputs;
2988   if (compute_logic_cone(n, partition, inputs)) {
2989     const TypeVect* vt = n->bottom_type()->is_vect();
2990     Node* pn = partition.at(partition.size() - 1);
2991     Node* mask = pn->is_predicated_vector() ? pn->in(pn->req()-1) : nullptr;
2992     if (mask == nullptr ||
2993         Matcher::match_rule_supported_vector_masked(Op_MacroLogicV, vt->length(), vt->element_basic_type())) {
2994       Node* macro_logic = xform_to_MacroLogicV(igvn, vt, partition, inputs);
2995       VectorNode::trace_new_vector(macro_logic, "MacroLogic");
2996       igvn.replace_node(n, macro_logic);
2997     }
2998   }
2999 }
3000 
3001 void Compile::optimize_logic_cones(PhaseIterGVN &igvn) {
3002   ResourceMark rm;
3003   if (Matcher::match_rule_supported(Op_MacroLogicV)) {
3004     Unique_Node_List list;
3005     collect_logic_cone_roots(list);
3006 
3007     while (list.size() > 0) {
3008       Node* n = list.pop();
3009       const TypeVect* vt = n->bottom_type()->is_vect();
3010       bool supported = Matcher::match_rule_supported_vector(Op_MacroLogicV, vt->length(), vt->element_basic_type());
3011       if (supported) {
3012         VectorSet visited(comp_arena());
3013         process_logic_cone_root(igvn, n, visited);
3014       }
3015     }
3016   }
3017 }
3018 
3019 //------------------------------Code_Gen---------------------------------------
3020 // Given a graph, generate code for it
3021 void Compile::Code_Gen() {
3022   if (failing()) {
3023     return;
3024   }
3025 
3026   // Perform instruction selection.  You might think we could reclaim Matcher
3027   // memory PDQ, but actually the Matcher is used in generating spill code.
3028   // Internals of the Matcher (including some VectorSets) must remain live
3029   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
3030   // set a bit in reclaimed memory.
3031 
3032   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
3033   // nodes.  Mapping is only valid at the root of each matched subtree.
3034   NOT_PRODUCT( verify_graph_edges(); )
3035 
3036   Matcher matcher;
3037   _matcher = &matcher;
3038   {
3039     TracePhase tp(_t_matcher);
3040     matcher.match();
3041     if (failing()) {
3042       return;
3043     }
3044   }
3045   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
3046   // nodes.  Mapping is only valid at the root of each matched subtree.
3047   NOT_PRODUCT( verify_graph_edges(); )
3048 
3049   // If you have too many nodes, or if matching has failed, bail out
3050   check_node_count(0, "out of nodes matching instructions");
3051   if (failing()) {
3052     return;
3053   }
3054 
3055   print_method(PHASE_MATCHING, 2);
3056 
3057   // Build a proper-looking CFG
3058   PhaseCFG cfg(node_arena(), root(), matcher);
3059   if (failing()) {
3060     return;
3061   }
3062   _cfg = &cfg;
3063   {
3064     TracePhase tp(_t_scheduler);
3065     bool success = cfg.do_global_code_motion();
3066     if (!success) {
3067       return;
3068     }
3069 
3070     print_method(PHASE_GLOBAL_CODE_MOTION, 2);
3071     NOT_PRODUCT( verify_graph_edges(); )
3072     cfg.verify();
3073     if (failing()) {
3074       return;
3075     }
3076   }
3077 
3078   PhaseChaitin regalloc(unique(), cfg, matcher, false);
3079   _regalloc = &regalloc;
3080   {
3081     TracePhase tp(_t_registerAllocation);
3082     // Perform register allocation.  After Chaitin, use-def chains are
3083     // no longer accurate (at spill code) and so must be ignored.
3084     // Node->LRG->reg mappings are still accurate.
3085     _regalloc->Register_Allocate();
3086 
3087     // Bail out if the allocator builds too many nodes
3088     if (failing()) {
3089       return;
3090     }
3091 
3092     print_method(PHASE_REGISTER_ALLOCATION, 2);
3093   }
3094 
3095   // Prior to register allocation we kept empty basic blocks in case the
3096   // the allocator needed a place to spill.  After register allocation we
3097   // are not adding any new instructions.  If any basic block is empty, we
3098   // can now safely remove it.
3099   {
3100     TracePhase tp(_t_blockOrdering);
3101     cfg.remove_empty_blocks();
3102     if (do_freq_based_layout()) {
3103       PhaseBlockLayout layout(cfg);
3104     } else {
3105       cfg.set_loop_alignment();
3106     }
3107     cfg.fixup_flow();
3108     cfg.remove_unreachable_blocks();
3109     cfg.verify_dominator_tree();
3110     print_method(PHASE_BLOCK_ORDERING, 3);
3111   }
3112 
3113   // Apply peephole optimizations
3114   if( OptoPeephole ) {
3115     TracePhase tp(_t_peephole);
3116     PhasePeephole peep( _regalloc, cfg);
3117     peep.do_transform();
3118     print_method(PHASE_PEEPHOLE, 3);
3119   }
3120 
3121   // Do late expand if CPU requires this.
3122   if (Matcher::require_postalloc_expand) {
3123     TracePhase tp(_t_postalloc_expand);
3124     cfg.postalloc_expand(_regalloc);
3125     print_method(PHASE_POSTALLOC_EXPAND, 3);
3126   }
3127 
3128 #ifdef ASSERT
3129   {
3130     CompilationMemoryStatistic::do_test_allocations();
3131     if (failing()) return;
3132   }
3133 #endif
3134 
3135   // Convert Nodes to instruction bits in a buffer
3136   {
3137     TracePhase tp(_t_output);
3138     PhaseOutput output;
3139     output.Output();
3140     if (failing())  return;
3141     output.install();
3142     print_method(PHASE_FINAL_CODE, 1); // Compile::_output is not null here
3143   }
3144 
3145   // He's dead, Jim.
3146   _cfg     = (PhaseCFG*)((intptr_t)0xdeadbeef);
3147   _regalloc = (PhaseChaitin*)((intptr_t)0xdeadbeef);
3148 }
3149 
3150 //------------------------------Final_Reshape_Counts---------------------------
3151 // This class defines counters to help identify when a method
3152 // may/must be executed using hardware with only 24-bit precision.
3153 struct Final_Reshape_Counts : public StackObj {
3154   int  _call_count;             // count non-inlined 'common' calls
3155   int  _float_count;            // count float ops requiring 24-bit precision
3156   int  _double_count;           // count double ops requiring more precision
3157   int  _java_call_count;        // count non-inlined 'java' calls
3158   int  _inner_loop_count;       // count loops which need alignment
3159   VectorSet _visited;           // Visitation flags
3160   Node_List _tests;             // Set of IfNodes & PCTableNodes
3161 
3162   Final_Reshape_Counts() :
3163     _call_count(0), _float_count(0), _double_count(0),
3164     _java_call_count(0), _inner_loop_count(0) { }
3165 
3166   void inc_call_count  () { _call_count  ++; }
3167   void inc_float_count () { _float_count ++; }
3168   void inc_double_count() { _double_count++; }
3169   void inc_java_call_count() { _java_call_count++; }
3170   void inc_inner_loop_count() { _inner_loop_count++; }
3171 
3172   int  get_call_count  () const { return _call_count  ; }
3173   int  get_float_count () const { return _float_count ; }
3174   int  get_double_count() const { return _double_count; }
3175   int  get_java_call_count() const { return _java_call_count; }
3176   int  get_inner_loop_count() const { return _inner_loop_count; }
3177 };
3178 
3179 //------------------------------final_graph_reshaping_impl----------------------
3180 // Implement items 1-5 from final_graph_reshaping below.
3181 void Compile::final_graph_reshaping_impl(Node *n, Final_Reshape_Counts& frc, Unique_Node_List& dead_nodes) {
3182 
3183   if ( n->outcnt() == 0 ) return; // dead node
3184   uint nop = n->Opcode();
3185 
3186   // Check for 2-input instruction with "last use" on right input.
3187   // Swap to left input.  Implements item (2).
3188   if( n->req() == 3 &&          // two-input instruction
3189       n->in(1)->outcnt() > 1 && // left use is NOT a last use
3190       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
3191       n->in(2)->outcnt() == 1 &&// right use IS a last use
3192       !n->in(2)->is_Con() ) {   // right use is not a constant
3193     // Check for commutative opcode
3194     switch( nop ) {
3195     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddL:
3196     case Op_MaxI:  case Op_MaxL:  case Op_MaxF:  case Op_MaxD:
3197     case Op_MinI:  case Op_MinL:  case Op_MinF:  case Op_MinD:
3198     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulL:
3199     case Op_AndL:  case Op_XorL:  case Op_OrL:
3200     case Op_AndI:  case Op_XorI:  case Op_OrI: {
3201       // Move "last use" input to left by swapping inputs
3202       n->swap_edges(1, 2);
3203       break;
3204     }
3205     default:
3206       break;
3207     }
3208   }
3209 
3210 #ifdef ASSERT
3211   if( n->is_Mem() ) {
3212     int alias_idx = get_alias_index(n->as_Mem()->adr_type());
3213     assert( n->in(0) != nullptr || alias_idx != Compile::AliasIdxRaw ||
3214             // oop will be recorded in oop map if load crosses safepoint
3215             (n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
3216                               LoadNode::is_immutable_value(n->in(MemNode::Address)))),
3217             "raw memory operations should have control edge");
3218   }
3219   if (n->is_MemBar()) {
3220     MemBarNode* mb = n->as_MemBar();
3221     if (mb->trailing_store() || mb->trailing_load_store()) {
3222       assert(mb->leading_membar()->trailing_membar() == mb, "bad membar pair");
3223       Node* mem = BarrierSet::barrier_set()->barrier_set_c2()->step_over_gc_barrier(mb->in(MemBarNode::Precedent));
3224       assert((mb->trailing_store() && mem->is_Store() && mem->as_Store()->is_release()) ||
3225              (mb->trailing_load_store() && mem->is_LoadStore()), "missing mem op");
3226     } else if (mb->leading()) {
3227       assert(mb->trailing_membar()->leading_membar() == mb, "bad membar pair");
3228     }
3229   }
3230 #endif
3231   // Count FPU ops and common calls, implements item (3)
3232   bool gc_handled = BarrierSet::barrier_set()->barrier_set_c2()->final_graph_reshaping(this, n, nop, dead_nodes);
3233   if (!gc_handled) {
3234     final_graph_reshaping_main_switch(n, frc, nop, dead_nodes);
3235   }
3236 
3237   // Collect CFG split points
3238   if (n->is_MultiBranch() && !n->is_RangeCheck()) {
3239     frc._tests.push(n);
3240   }
3241 }
3242 
3243 void Compile::handle_div_mod_op(Node* n, BasicType bt, bool is_unsigned) {
3244   if (!UseDivMod) {
3245     return;
3246   }
3247 
3248   // Check if "a % b" and "a / b" both exist
3249   Node* d = n->find_similar(Op_DivIL(bt, is_unsigned));
3250   if (d == nullptr) {
3251     return;
3252   }
3253 
3254   // Replace them with a fused divmod if supported
3255   if (Matcher::has_match_rule(Op_DivModIL(bt, is_unsigned))) {
3256     DivModNode* divmod = DivModNode::make(n, bt, is_unsigned);
3257     // If the divisor input for a Div (or Mod etc.) is not zero, then the control input of the Div is set to zero.
3258     // It could be that the divisor input is found not zero because its type is narrowed down by a CastII in the
3259     // subgraph for that input. Range check CastIIs are removed during final graph reshape. To preserve the dependency
3260     // carried by a CastII, precedence edges are added to the Div node. We need to transfer the precedence edges to the
3261     // DivMod node so the dependency is not lost.
3262     divmod->add_prec_from(n);
3263     divmod->add_prec_from(d);
3264     d->subsume_by(divmod->div_proj(), this);
3265     n->subsume_by(divmod->mod_proj(), this);
3266   } else {
3267     // Replace "a % b" with "a - ((a / b) * b)"
3268     Node* mult = MulNode::make(d, d->in(2), bt);
3269     Node* sub = SubNode::make(d->in(1), mult, bt);
3270     n->subsume_by(sub, this);
3271   }
3272 }
3273 
3274 void Compile::final_graph_reshaping_main_switch(Node* n, Final_Reshape_Counts& frc, uint nop, Unique_Node_List& dead_nodes) {
3275   switch( nop ) {
3276   // Count all float operations that may use FPU
3277   case Op_AddF:
3278   case Op_SubF:
3279   case Op_MulF:
3280   case Op_DivF:
3281   case Op_NegF:
3282   case Op_ModF:
3283   case Op_ConvI2F:
3284   case Op_ConF:
3285   case Op_CmpF:
3286   case Op_CmpF3:
3287   case Op_StoreF:
3288   case Op_LoadF:
3289   // case Op_ConvL2F: // longs are split into 32-bit halves
3290     frc.inc_float_count();
3291     break;
3292 
3293   case Op_ConvF2D:
3294   case Op_ConvD2F:
3295     frc.inc_float_count();
3296     frc.inc_double_count();
3297     break;
3298 
3299   // Count all double operations that may use FPU
3300   case Op_AddD:
3301   case Op_SubD:
3302   case Op_MulD:
3303   case Op_DivD:
3304   case Op_NegD:
3305   case Op_ModD:
3306   case Op_ConvI2D:
3307   case Op_ConvD2I:
3308   // case Op_ConvL2D: // handled by leaf call
3309   // case Op_ConvD2L: // handled by leaf call
3310   case Op_ConD:
3311   case Op_CmpD:
3312   case Op_CmpD3:
3313   case Op_StoreD:
3314   case Op_LoadD:
3315   case Op_LoadD_unaligned:
3316     frc.inc_double_count();
3317     break;
3318   case Op_Opaque1:              // Remove Opaque Nodes before matching
3319     n->subsume_by(n->in(1), this);
3320     break;
3321   case Op_CallLeafPure: {
3322     // If the pure call is not supported, then lower to a CallLeaf.
3323     if (!Matcher::match_rule_supported(Op_CallLeafPure)) {
3324       CallNode* call = n->as_Call();
3325       CallNode* new_call = new CallLeafNode(call->tf(), call->entry_point(),
3326                                             call->_name, TypeRawPtr::BOTTOM);
3327       new_call->init_req(TypeFunc::Control, call->in(TypeFunc::Control));
3328       new_call->init_req(TypeFunc::I_O, C->top());
3329       new_call->init_req(TypeFunc::Memory, C->top());
3330       new_call->init_req(TypeFunc::ReturnAdr, C->top());
3331       new_call->init_req(TypeFunc::FramePtr, C->top());
3332       for (unsigned int i = TypeFunc::Parms; i < call->tf()->domain()->cnt(); i++) {
3333         new_call->init_req(i, call->in(i));
3334       }
3335       n->subsume_by(new_call, this);
3336     }
3337     frc.inc_call_count();
3338     break;
3339   }
3340   case Op_CallStaticJava:
3341   case Op_CallJava:
3342   case Op_CallDynamicJava:
3343     frc.inc_java_call_count(); // Count java call site;
3344   case Op_CallRuntime:
3345   case Op_CallLeaf:
3346   case Op_CallLeafVector:
3347   case Op_CallLeafNoFP: {
3348     assert (n->is_Call(), "");
3349     CallNode *call = n->as_Call();
3350     // Count call sites where the FP mode bit would have to be flipped.
3351     // Do not count uncommon runtime calls:
3352     // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
3353     // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
3354     if (!call->is_CallStaticJava() || !call->as_CallStaticJava()->_name) {
3355       frc.inc_call_count();   // Count the call site
3356     } else {                  // See if uncommon argument is shared
3357       Node *n = call->in(TypeFunc::Parms);
3358       int nop = n->Opcode();
3359       // Clone shared simple arguments to uncommon calls, item (1).
3360       if (n->outcnt() > 1 &&
3361           !n->is_Proj() &&
3362           nop != Op_CreateEx &&
3363           nop != Op_CheckCastPP &&
3364           nop != Op_DecodeN &&
3365           nop != Op_DecodeNKlass &&
3366           !n->is_Mem() &&
3367           !n->is_Phi()) {
3368         Node *x = n->clone();
3369         call->set_req(TypeFunc::Parms, x);
3370       }
3371     }
3372     break;
3373   }
3374   case Op_StoreB:
3375   case Op_StoreC:
3376   case Op_StoreI:
3377   case Op_StoreL:
3378   case Op_CompareAndSwapB:
3379   case Op_CompareAndSwapS:
3380   case Op_CompareAndSwapI:
3381   case Op_CompareAndSwapL:
3382   case Op_CompareAndSwapP:
3383   case Op_CompareAndSwapN:
3384   case Op_WeakCompareAndSwapB:
3385   case Op_WeakCompareAndSwapS:
3386   case Op_WeakCompareAndSwapI:
3387   case Op_WeakCompareAndSwapL:
3388   case Op_WeakCompareAndSwapP:
3389   case Op_WeakCompareAndSwapN:
3390   case Op_CompareAndExchangeB:
3391   case Op_CompareAndExchangeS:
3392   case Op_CompareAndExchangeI:
3393   case Op_CompareAndExchangeL:
3394   case Op_CompareAndExchangeP:
3395   case Op_CompareAndExchangeN:
3396   case Op_GetAndAddS:
3397   case Op_GetAndAddB:
3398   case Op_GetAndAddI:
3399   case Op_GetAndAddL:
3400   case Op_GetAndSetS:
3401   case Op_GetAndSetB:
3402   case Op_GetAndSetI:
3403   case Op_GetAndSetL:
3404   case Op_GetAndSetP:
3405   case Op_GetAndSetN:
3406   case Op_StoreP:
3407   case Op_StoreN:
3408   case Op_StoreNKlass:
3409   case Op_LoadB:
3410   case Op_LoadUB:
3411   case Op_LoadUS:
3412   case Op_LoadI:
3413   case Op_LoadKlass:
3414   case Op_LoadNKlass:
3415   case Op_LoadL:
3416   case Op_LoadL_unaligned:
3417   case Op_LoadP:
3418   case Op_LoadN:
3419   case Op_LoadRange:
3420   case Op_LoadS:
3421     break;
3422 
3423   case Op_AddP: {               // Assert sane base pointers
3424     Node *addp = n->in(AddPNode::Address);
3425     assert(n->as_AddP()->address_input_has_same_base(), "Base pointers must match (addp %u)", addp->_idx );
3426 #ifdef _LP64
3427     if ((UseCompressedOops || UseCompressedClassPointers) &&
3428         addp->Opcode() == Op_ConP &&
3429         addp == n->in(AddPNode::Base) &&
3430         n->in(AddPNode::Offset)->is_Con()) {
3431       // If the transformation of ConP to ConN+DecodeN is beneficial depends
3432       // on the platform and on the compressed oops mode.
3433       // Use addressing with narrow klass to load with offset on x86.
3434       // Some platforms can use the constant pool to load ConP.
3435       // Do this transformation here since IGVN will convert ConN back to ConP.
3436       const Type* t = addp->bottom_type();
3437       bool is_oop   = t->isa_oopptr() != nullptr;
3438       bool is_klass = t->isa_klassptr() != nullptr;
3439 
3440       if ((is_oop   && UseCompressedOops          && Matcher::const_oop_prefer_decode()  ) ||
3441           (is_klass && UseCompressedClassPointers && Matcher::const_klass_prefer_decode() &&
3442            t->isa_klassptr()->exact_klass()->is_in_encoding_range())) {
3443         Node* nn = nullptr;
3444 
3445         int op = is_oop ? Op_ConN : Op_ConNKlass;
3446 
3447         // Look for existing ConN node of the same exact type.
3448         Node* r  = root();
3449         uint cnt = r->outcnt();
3450         for (uint i = 0; i < cnt; i++) {
3451           Node* m = r->raw_out(i);
3452           if (m!= nullptr && m->Opcode() == op &&
3453               m->bottom_type()->make_ptr() == t) {
3454             nn = m;
3455             break;
3456           }
3457         }
3458         if (nn != nullptr) {
3459           // Decode a narrow oop to match address
3460           // [R12 + narrow_oop_reg<<3 + offset]
3461           if (is_oop) {
3462             nn = new DecodeNNode(nn, t);
3463           } else {
3464             nn = new DecodeNKlassNode(nn, t);
3465           }
3466           // Check for succeeding AddP which uses the same Base.
3467           // Otherwise we will run into the assertion above when visiting that guy.
3468           for (uint i = 0; i < n->outcnt(); ++i) {
3469             Node *out_i = n->raw_out(i);
3470             if (out_i && out_i->is_AddP() && out_i->in(AddPNode::Base) == addp) {
3471               out_i->set_req(AddPNode::Base, nn);
3472 #ifdef ASSERT
3473               for (uint j = 0; j < out_i->outcnt(); ++j) {
3474                 Node *out_j = out_i->raw_out(j);
3475                 assert(out_j == nullptr || !out_j->is_AddP() || out_j->in(AddPNode::Base) != addp,
3476                        "more than 2 AddP nodes in a chain (out_j %u)", out_j->_idx);
3477               }
3478 #endif
3479             }
3480           }
3481           n->set_req(AddPNode::Base, nn);
3482           n->set_req(AddPNode::Address, nn);
3483           if (addp->outcnt() == 0) {
3484             addp->disconnect_inputs(this);
3485           }
3486         }
3487       }
3488     }
3489 #endif
3490     break;
3491   }
3492 
3493   case Op_CastPP: {
3494     // Remove CastPP nodes to gain more freedom during scheduling but
3495     // keep the dependency they encode as control or precedence edges
3496     // (if control is set already) on memory operations. Some CastPP
3497     // nodes don't have a control (don't carry a dependency): skip
3498     // those.
3499     if (n->in(0) != nullptr) {
3500       ResourceMark rm;
3501       Unique_Node_List wq;
3502       wq.push(n);
3503       for (uint next = 0; next < wq.size(); ++next) {
3504         Node *m = wq.at(next);
3505         for (DUIterator_Fast imax, i = m->fast_outs(imax); i < imax; i++) {
3506           Node* use = m->fast_out(i);
3507           if (use->is_Mem() || use->is_EncodeNarrowPtr()) {
3508             use->ensure_control_or_add_prec(n->in(0));
3509           } else {
3510             switch(use->Opcode()) {
3511             case Op_AddP:
3512             case Op_DecodeN:
3513             case Op_DecodeNKlass:
3514             case Op_CheckCastPP:
3515             case Op_CastPP:
3516               wq.push(use);
3517               break;
3518             }
3519           }
3520         }
3521       }
3522     }
3523     const bool is_LP64 = LP64_ONLY(true) NOT_LP64(false);
3524     if (is_LP64 && n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
3525       Node* in1 = n->in(1);
3526       const Type* t = n->bottom_type();
3527       Node* new_in1 = in1->clone();
3528       new_in1->as_DecodeN()->set_type(t);
3529 
3530       if (!Matcher::narrow_oop_use_complex_address()) {
3531         //
3532         // x86, ARM and friends can handle 2 adds in addressing mode
3533         // and Matcher can fold a DecodeN node into address by using
3534         // a narrow oop directly and do implicit null check in address:
3535         //
3536         // [R12 + narrow_oop_reg<<3 + offset]
3537         // NullCheck narrow_oop_reg
3538         //
3539         // On other platforms (Sparc) we have to keep new DecodeN node and
3540         // use it to do implicit null check in address:
3541         //
3542         // decode_not_null narrow_oop_reg, base_reg
3543         // [base_reg + offset]
3544         // NullCheck base_reg
3545         //
3546         // Pin the new DecodeN node to non-null path on these platform (Sparc)
3547         // to keep the information to which null check the new DecodeN node
3548         // corresponds to use it as value in implicit_null_check().
3549         //
3550         new_in1->set_req(0, n->in(0));
3551       }
3552 
3553       n->subsume_by(new_in1, this);
3554       if (in1->outcnt() == 0) {
3555         in1->disconnect_inputs(this);
3556       }
3557     } else {
3558       n->subsume_by(n->in(1), this);
3559       if (n->outcnt() == 0) {
3560         n->disconnect_inputs(this);
3561       }
3562     }
3563     break;
3564   }
3565   case Op_CastII: {
3566     n->as_CastII()->remove_range_check_cast(this);
3567     break;
3568   }
3569 #ifdef _LP64
3570   case Op_CmpP:
3571     // Do this transformation here to preserve CmpPNode::sub() and
3572     // other TypePtr related Ideal optimizations (for example, ptr nullness).
3573     if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
3574       Node* in1 = n->in(1);
3575       Node* in2 = n->in(2);
3576       if (!in1->is_DecodeNarrowPtr()) {
3577         in2 = in1;
3578         in1 = n->in(2);
3579       }
3580       assert(in1->is_DecodeNarrowPtr(), "sanity");
3581 
3582       Node* new_in2 = nullptr;
3583       if (in2->is_DecodeNarrowPtr()) {
3584         assert(in2->Opcode() == in1->Opcode(), "must be same node type");
3585         new_in2 = in2->in(1);
3586       } else if (in2->Opcode() == Op_ConP) {
3587         const Type* t = in2->bottom_type();
3588         if (t == TypePtr::NULL_PTR) {
3589           assert(in1->is_DecodeN(), "compare klass to null?");
3590           // Don't convert CmpP null check into CmpN if compressed
3591           // oops implicit null check is not generated.
3592           // This will allow to generate normal oop implicit null check.
3593           if (Matcher::gen_narrow_oop_implicit_null_checks())
3594             new_in2 = ConNode::make(TypeNarrowOop::NULL_PTR);
3595           //
3596           // This transformation together with CastPP transformation above
3597           // will generated code for implicit null checks for compressed oops.
3598           //
3599           // The original code after Optimize()
3600           //
3601           //    LoadN memory, narrow_oop_reg
3602           //    decode narrow_oop_reg, base_reg
3603           //    CmpP base_reg, nullptr
3604           //    CastPP base_reg // NotNull
3605           //    Load [base_reg + offset], val_reg
3606           //
3607           // after these transformations will be
3608           //
3609           //    LoadN memory, narrow_oop_reg
3610           //    CmpN narrow_oop_reg, nullptr
3611           //    decode_not_null narrow_oop_reg, base_reg
3612           //    Load [base_reg + offset], val_reg
3613           //
3614           // and the uncommon path (== nullptr) will use narrow_oop_reg directly
3615           // since narrow oops can be used in debug info now (see the code in
3616           // final_graph_reshaping_walk()).
3617           //
3618           // At the end the code will be matched to
3619           // on x86:
3620           //
3621           //    Load_narrow_oop memory, narrow_oop_reg
3622           //    Load [R12 + narrow_oop_reg<<3 + offset], val_reg
3623           //    NullCheck narrow_oop_reg
3624           //
3625           // and on sparc:
3626           //
3627           //    Load_narrow_oop memory, narrow_oop_reg
3628           //    decode_not_null narrow_oop_reg, base_reg
3629           //    Load [base_reg + offset], val_reg
3630           //    NullCheck base_reg
3631           //
3632         } else if (t->isa_oopptr()) {
3633           new_in2 = ConNode::make(t->make_narrowoop());
3634         } else if (t->isa_klassptr()) {
3635           ciKlass* klass = t->is_klassptr()->exact_klass();
3636           if (klass->is_in_encoding_range()) {
3637             new_in2 = ConNode::make(t->make_narrowklass());
3638           }
3639         }
3640       }
3641       if (new_in2 != nullptr) {
3642         Node* cmpN = new CmpNNode(in1->in(1), new_in2);
3643         n->subsume_by(cmpN, this);
3644         if (in1->outcnt() == 0) {
3645           in1->disconnect_inputs(this);
3646         }
3647         if (in2->outcnt() == 0) {
3648           in2->disconnect_inputs(this);
3649         }
3650       }
3651     }
3652     break;
3653 
3654   case Op_DecodeN:
3655   case Op_DecodeNKlass:
3656     assert(!n->in(1)->is_EncodeNarrowPtr(), "should be optimized out");
3657     // DecodeN could be pinned when it can't be fold into
3658     // an address expression, see the code for Op_CastPP above.
3659     assert(n->in(0) == nullptr || (UseCompressedOops && !Matcher::narrow_oop_use_complex_address()), "no control");
3660     break;
3661 
3662   case Op_EncodeP:
3663   case Op_EncodePKlass: {
3664     Node* in1 = n->in(1);
3665     if (in1->is_DecodeNarrowPtr()) {
3666       n->subsume_by(in1->in(1), this);
3667     } else if (in1->Opcode() == Op_ConP) {
3668       const Type* t = in1->bottom_type();
3669       if (t == TypePtr::NULL_PTR) {
3670         assert(t->isa_oopptr(), "null klass?");
3671         n->subsume_by(ConNode::make(TypeNarrowOop::NULL_PTR), this);
3672       } else if (t->isa_oopptr()) {
3673         n->subsume_by(ConNode::make(t->make_narrowoop()), this);
3674       } else if (t->isa_klassptr()) {
3675         ciKlass* klass = t->is_klassptr()->exact_klass();
3676         if (klass->is_in_encoding_range()) {
3677           n->subsume_by(ConNode::make(t->make_narrowklass()), this);
3678         } else {
3679           assert(false, "unencodable klass in ConP -> EncodeP");
3680           C->record_failure("unencodable klass in ConP -> EncodeP");
3681         }
3682       }
3683     }
3684     if (in1->outcnt() == 0) {
3685       in1->disconnect_inputs(this);
3686     }
3687     break;
3688   }
3689 
3690   case Op_Proj: {
3691     if (OptimizeStringConcat || IncrementalInline) {
3692       ProjNode* proj = n->as_Proj();
3693       if (proj->_is_io_use) {
3694         assert(proj->_con == TypeFunc::I_O || proj->_con == TypeFunc::Memory, "");
3695         // Separate projections were used for the exception path which
3696         // are normally removed by a late inline.  If it wasn't inlined
3697         // then they will hang around and should just be replaced with
3698         // the original one. Merge them.
3699         Node* non_io_proj = proj->in(0)->as_Multi()->proj_out_or_null(proj->_con, false /*is_io_use*/);
3700         if (non_io_proj  != nullptr) {
3701           proj->subsume_by(non_io_proj , this);
3702         }
3703       }
3704     }
3705     break;
3706   }
3707 
3708   case Op_Phi:
3709     if (n->as_Phi()->bottom_type()->isa_narrowoop() || n->as_Phi()->bottom_type()->isa_narrowklass()) {
3710       // The EncodeP optimization may create Phi with the same edges
3711       // for all paths. It is not handled well by Register Allocator.
3712       Node* unique_in = n->in(1);
3713       assert(unique_in != nullptr, "");
3714       uint cnt = n->req();
3715       for (uint i = 2; i < cnt; i++) {
3716         Node* m = n->in(i);
3717         assert(m != nullptr, "");
3718         if (unique_in != m)
3719           unique_in = nullptr;
3720       }
3721       if (unique_in != nullptr) {
3722         n->subsume_by(unique_in, this);
3723       }
3724     }
3725     break;
3726 
3727 #endif
3728 
3729   case Op_ModI:
3730     handle_div_mod_op(n, T_INT, false);
3731     break;
3732 
3733   case Op_ModL:
3734     handle_div_mod_op(n, T_LONG, false);
3735     break;
3736 
3737   case Op_UModI:
3738     handle_div_mod_op(n, T_INT, true);
3739     break;
3740 
3741   case Op_UModL:
3742     handle_div_mod_op(n, T_LONG, true);
3743     break;
3744 
3745   case Op_LoadVector:
3746   case Op_StoreVector:
3747 #ifdef ASSERT
3748     // Add VerifyVectorAlignment node between adr and load / store.
3749     if (VerifyAlignVector && Matcher::has_match_rule(Op_VerifyVectorAlignment)) {
3750       bool must_verify_alignment = n->is_LoadVector() ? n->as_LoadVector()->must_verify_alignment() :
3751                                                         n->as_StoreVector()->must_verify_alignment();
3752       if (must_verify_alignment) {
3753         jlong vector_width = n->is_LoadVector() ? n->as_LoadVector()->memory_size() :
3754                                                   n->as_StoreVector()->memory_size();
3755         // The memory access should be aligned to the vector width in bytes.
3756         // However, the underlying array is possibly less well aligned, but at least
3757         // to ObjectAlignmentInBytes. Hence, even if multiple arrays are accessed in
3758         // a loop we can expect at least the following alignment:
3759         jlong guaranteed_alignment = MIN2(vector_width, (jlong)ObjectAlignmentInBytes);
3760         assert(2 <= guaranteed_alignment && guaranteed_alignment <= 64, "alignment must be in range");
3761         assert(is_power_of_2(guaranteed_alignment), "alignment must be power of 2");
3762         // Create mask from alignment. e.g. 0b1000 -> 0b0111
3763         jlong mask = guaranteed_alignment - 1;
3764         Node* mask_con = ConLNode::make(mask);
3765         VerifyVectorAlignmentNode* va = new VerifyVectorAlignmentNode(n->in(MemNode::Address), mask_con);
3766         n->set_req(MemNode::Address, va);
3767       }
3768     }
3769 #endif
3770     break;
3771 
3772   case Op_LoadVectorGather:
3773   case Op_StoreVectorScatter:
3774   case Op_LoadVectorGatherMasked:
3775   case Op_StoreVectorScatterMasked:
3776   case Op_VectorCmpMasked:
3777   case Op_VectorMaskGen:
3778   case Op_LoadVectorMasked:
3779   case Op_StoreVectorMasked:
3780     break;
3781 
3782   case Op_AddReductionVI:
3783   case Op_AddReductionVL:
3784   case Op_AddReductionVF:
3785   case Op_AddReductionVD:
3786   case Op_MulReductionVI:
3787   case Op_MulReductionVL:
3788   case Op_MulReductionVF:
3789   case Op_MulReductionVD:
3790   case Op_MinReductionV:
3791   case Op_MaxReductionV:
3792   case Op_UMinReductionV:
3793   case Op_UMaxReductionV:
3794   case Op_AndReductionV:
3795   case Op_OrReductionV:
3796   case Op_XorReductionV:
3797     break;
3798 
3799   case Op_PackB:
3800   case Op_PackS:
3801   case Op_PackI:
3802   case Op_PackF:
3803   case Op_PackL:
3804   case Op_PackD:
3805     if (n->req()-1 > 2) {
3806       // Replace many operand PackNodes with a binary tree for matching
3807       PackNode* p = (PackNode*) n;
3808       Node* btp = p->binary_tree_pack(1, n->req());
3809       n->subsume_by(btp, this);
3810     }
3811     break;
3812   case Op_Loop:
3813     assert(!n->as_Loop()->is_loop_nest_inner_loop() || _loop_opts_cnt == 0, "should have been turned into a counted loop");
3814   case Op_CountedLoop:
3815   case Op_LongCountedLoop:
3816   case Op_OuterStripMinedLoop:
3817     if (n->as_Loop()->is_inner_loop()) {
3818       frc.inc_inner_loop_count();
3819     }
3820     n->as_Loop()->verify_strip_mined(0);
3821     break;
3822   case Op_LShiftI:
3823   case Op_RShiftI:
3824   case Op_URShiftI:
3825   case Op_LShiftL:
3826   case Op_RShiftL:
3827   case Op_URShiftL:
3828     if (Matcher::need_masked_shift_count) {
3829       // The cpu's shift instructions don't restrict the count to the
3830       // lower 5/6 bits. We need to do the masking ourselves.
3831       Node* in2 = n->in(2);
3832       juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
3833       const TypeInt* t = in2->find_int_type();
3834       if (t != nullptr && t->is_con()) {
3835         juint shift = t->get_con();
3836         if (shift > mask) { // Unsigned cmp
3837           n->set_req(2, ConNode::make(TypeInt::make(shift & mask)));
3838         }
3839       } else {
3840         if (t == nullptr || t->_lo < 0 || t->_hi > (int)mask) {
3841           Node* shift = new AndINode(in2, ConNode::make(TypeInt::make(mask)));
3842           n->set_req(2, shift);
3843         }
3844       }
3845       if (in2->outcnt() == 0) { // Remove dead node
3846         in2->disconnect_inputs(this);
3847       }
3848     }
3849     break;
3850   case Op_MemBarStoreStore:
3851   case Op_MemBarRelease:
3852     // Break the link with AllocateNode: it is no longer useful and
3853     // confuses register allocation.
3854     if (n->req() > MemBarNode::Precedent) {
3855       n->set_req(MemBarNode::Precedent, top());
3856     }
3857     break;
3858   case Op_MemBarAcquire: {
3859     if (n->as_MemBar()->trailing_load() && n->req() > MemBarNode::Precedent) {
3860       // At parse time, the trailing MemBarAcquire for a volatile load
3861       // is created with an edge to the load. After optimizations,
3862       // that input may be a chain of Phis. If those phis have no
3863       // other use, then the MemBarAcquire keeps them alive and
3864       // register allocation can be confused.
3865       dead_nodes.push(n->in(MemBarNode::Precedent));
3866       n->set_req(MemBarNode::Precedent, top());
3867     }
3868     break;
3869   }
3870   case Op_Blackhole:
3871     break;
3872   case Op_RangeCheck: {
3873     RangeCheckNode* rc = n->as_RangeCheck();
3874     Node* iff = new IfNode(rc->in(0), rc->in(1), rc->_prob, rc->_fcnt);
3875     n->subsume_by(iff, this);
3876     frc._tests.push(iff);
3877     break;
3878   }
3879   case Op_ConvI2L: {
3880     if (!Matcher::convi2l_type_required) {
3881       // Code generation on some platforms doesn't need accurate
3882       // ConvI2L types. Widening the type can help remove redundant
3883       // address computations.
3884       n->as_Type()->set_type(TypeLong::INT);
3885       ResourceMark rm;
3886       Unique_Node_List wq;
3887       wq.push(n);
3888       for (uint next = 0; next < wq.size(); next++) {
3889         Node *m = wq.at(next);
3890 
3891         for(;;) {
3892           // Loop over all nodes with identical inputs edges as m
3893           Node* k = m->find_similar(m->Opcode());
3894           if (k == nullptr) {
3895             break;
3896           }
3897           // Push their uses so we get a chance to remove node made
3898           // redundant
3899           for (DUIterator_Fast imax, i = k->fast_outs(imax); i < imax; i++) {
3900             Node* u = k->fast_out(i);
3901             if (u->Opcode() == Op_LShiftL ||
3902                 u->Opcode() == Op_AddL ||
3903                 u->Opcode() == Op_SubL ||
3904                 u->Opcode() == Op_AddP) {
3905               wq.push(u);
3906             }
3907           }
3908           // Replace all nodes with identical edges as m with m
3909           k->subsume_by(m, this);
3910         }
3911       }
3912     }
3913     break;
3914   }
3915   case Op_CmpUL: {
3916     if (!Matcher::has_match_rule(Op_CmpUL)) {
3917       // No support for unsigned long comparisons
3918       ConINode* sign_pos = new ConINode(TypeInt::make(BitsPerLong - 1));
3919       Node* sign_bit_mask = new RShiftLNode(n->in(1), sign_pos);
3920       Node* orl = new OrLNode(n->in(1), sign_bit_mask);
3921       ConLNode* remove_sign_mask = new ConLNode(TypeLong::make(max_jlong));
3922       Node* andl = new AndLNode(orl, remove_sign_mask);
3923       Node* cmp = new CmpLNode(andl, n->in(2));
3924       n->subsume_by(cmp, this);
3925     }
3926     break;
3927   }
3928 #ifdef ASSERT
3929   case Op_ConNKlass: {
3930     const TypePtr* tp = n->as_Type()->type()->make_ptr();
3931     ciKlass* klass = tp->is_klassptr()->exact_klass();
3932     assert(klass->is_in_encoding_range(), "klass cannot be compressed");
3933     break;
3934   }
3935 #endif
3936   default:
3937     assert(!n->is_Call(), "");
3938     assert(!n->is_Mem(), "");
3939     assert(nop != Op_ProfileBoolean, "should be eliminated during IGVN");
3940     break;
3941   }
3942 }
3943 
3944 //------------------------------final_graph_reshaping_walk---------------------
3945 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
3946 // requires that the walk visits a node's inputs before visiting the node.
3947 void Compile::final_graph_reshaping_walk(Node_Stack& nstack, Node* root, Final_Reshape_Counts& frc, Unique_Node_List& dead_nodes) {
3948   Unique_Node_List sfpt;
3949 
3950   frc._visited.set(root->_idx); // first, mark node as visited
3951   uint cnt = root->req();
3952   Node *n = root;
3953   uint  i = 0;
3954   while (true) {
3955     if (i < cnt) {
3956       // Place all non-visited non-null inputs onto stack
3957       Node* m = n->in(i);
3958       ++i;
3959       if (m != nullptr && !frc._visited.test_set(m->_idx)) {
3960         if (m->is_SafePoint() && m->as_SafePoint()->jvms() != nullptr) {
3961           // compute worst case interpreter size in case of a deoptimization
3962           update_interpreter_frame_size(m->as_SafePoint()->jvms()->interpreter_frame_size());
3963 
3964           sfpt.push(m);
3965         }
3966         cnt = m->req();
3967         nstack.push(n, i); // put on stack parent and next input's index
3968         n = m;
3969         i = 0;
3970       }
3971     } else {
3972       // Now do post-visit work
3973       final_graph_reshaping_impl(n, frc, dead_nodes);
3974       if (nstack.is_empty())
3975         break;             // finished
3976       n = nstack.node();   // Get node from stack
3977       cnt = n->req();
3978       i = nstack.index();
3979       nstack.pop();        // Shift to the next node on stack
3980     }
3981   }
3982 
3983   // Skip next transformation if compressed oops are not used.
3984   if ((UseCompressedOops && !Matcher::gen_narrow_oop_implicit_null_checks()) ||
3985       (!UseCompressedOops && !UseCompressedClassPointers))
3986     return;
3987 
3988   // Go over safepoints nodes to skip DecodeN/DecodeNKlass nodes for debug edges.
3989   // It could be done for an uncommon traps or any safepoints/calls
3990   // if the DecodeN/DecodeNKlass node is referenced only in a debug info.
3991   while (sfpt.size() > 0) {
3992     n = sfpt.pop();
3993     JVMState *jvms = n->as_SafePoint()->jvms();
3994     assert(jvms != nullptr, "sanity");
3995     int start = jvms->debug_start();
3996     int end   = n->req();
3997     bool is_uncommon = (n->is_CallStaticJava() &&
3998                         n->as_CallStaticJava()->uncommon_trap_request() != 0);
3999     for (int j = start; j < end; j++) {
4000       Node* in = n->in(j);
4001       if (in->is_DecodeNarrowPtr()) {
4002         bool safe_to_skip = true;
4003         if (!is_uncommon ) {
4004           // Is it safe to skip?
4005           for (uint i = 0; i < in->outcnt(); i++) {
4006             Node* u = in->raw_out(i);
4007             if (!u->is_SafePoint() ||
4008                 (u->is_Call() && u->as_Call()->has_non_debug_use(n))) {
4009               safe_to_skip = false;
4010             }
4011           }
4012         }
4013         if (safe_to_skip) {
4014           n->set_req(j, in->in(1));
4015         }
4016         if (in->outcnt() == 0) {
4017           in->disconnect_inputs(this);
4018         }
4019       }
4020     }
4021   }
4022 }
4023 
4024 //------------------------------final_graph_reshaping--------------------------
4025 // Final Graph Reshaping.
4026 //
4027 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
4028 //     and not commoned up and forced early.  Must come after regular
4029 //     optimizations to avoid GVN undoing the cloning.  Clone constant
4030 //     inputs to Loop Phis; these will be split by the allocator anyways.
4031 //     Remove Opaque nodes.
4032 // (2) Move last-uses by commutative operations to the left input to encourage
4033 //     Intel update-in-place two-address operations and better register usage
4034 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
4035 //     calls canonicalizing them back.
4036 // (3) Count the number of double-precision FP ops, single-precision FP ops
4037 //     and call sites.  On Intel, we can get correct rounding either by
4038 //     forcing singles to memory (requires extra stores and loads after each
4039 //     FP bytecode) or we can set a rounding mode bit (requires setting and
4040 //     clearing the mode bit around call sites).  The mode bit is only used
4041 //     if the relative frequency of single FP ops to calls is low enough.
4042 //     This is a key transform for SPEC mpeg_audio.
4043 // (4) Detect infinite loops; blobs of code reachable from above but not
4044 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
4045 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
4046 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
4047 //     Detection is by looking for IfNodes where only 1 projection is
4048 //     reachable from below or CatchNodes missing some targets.
4049 // (5) Assert for insane oop offsets in debug mode.
4050 
4051 bool Compile::final_graph_reshaping() {
4052   // an infinite loop may have been eliminated by the optimizer,
4053   // in which case the graph will be empty.
4054   if (root()->req() == 1) {
4055     // Do not compile method that is only a trivial infinite loop,
4056     // since the content of the loop may have been eliminated.
4057     record_method_not_compilable("trivial infinite loop");
4058     return true;
4059   }
4060 
4061   // Expensive nodes have their control input set to prevent the GVN
4062   // from freely commoning them. There's no GVN beyond this point so
4063   // no need to keep the control input. We want the expensive nodes to
4064   // be freely moved to the least frequent code path by gcm.
4065   assert(OptimizeExpensiveOps || expensive_count() == 0, "optimization off but list non empty?");
4066   for (int i = 0; i < expensive_count(); i++) {
4067     _expensive_nodes.at(i)->set_req(0, nullptr);
4068   }
4069 
4070   Final_Reshape_Counts frc;
4071 
4072   // Visit everybody reachable!
4073   // Allocate stack of size C->live_nodes()/2 to avoid frequent realloc
4074   Node_Stack nstack(live_nodes() >> 1);
4075   Unique_Node_List dead_nodes;
4076   final_graph_reshaping_walk(nstack, root(), frc, dead_nodes);
4077 
4078   // Check for unreachable (from below) code (i.e., infinite loops).
4079   for( uint i = 0; i < frc._tests.size(); i++ ) {
4080     MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
4081     // Get number of CFG targets.
4082     // Note that PCTables include exception targets after calls.
4083     uint required_outcnt = n->required_outcnt();
4084     if (n->outcnt() != required_outcnt) {
4085       // Check for a few special cases.  Rethrow Nodes never take the
4086       // 'fall-thru' path, so expected kids is 1 less.
4087       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
4088         if (n->in(0)->in(0)->is_Call()) {
4089           CallNode* call = n->in(0)->in(0)->as_Call();
4090           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
4091             required_outcnt--;      // Rethrow always has 1 less kid
4092           } else if (call->req() > TypeFunc::Parms &&
4093                      call->is_CallDynamicJava()) {
4094             // Check for null receiver. In such case, the optimizer has
4095             // detected that the virtual call will always result in a null
4096             // pointer exception. The fall-through projection of this CatchNode
4097             // will not be populated.
4098             Node* arg0 = call->in(TypeFunc::Parms);
4099             if (arg0->is_Type() &&
4100                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
4101               required_outcnt--;
4102             }
4103           } else if (call->entry_point() == OptoRuntime::new_array_Java() ||
4104                      call->entry_point() == OptoRuntime::new_array_nozero_Java()) {
4105             // Check for illegal array length. In such case, the optimizer has
4106             // detected that the allocation attempt will always result in an
4107             // exception. There is no fall-through projection of this CatchNode .
4108             assert(call->is_CallStaticJava(), "static call expected");
4109             assert(call->req() == call->jvms()->endoff() + 1, "missing extra input");
4110             uint valid_length_test_input = call->req() - 1;
4111             Node* valid_length_test = call->in(valid_length_test_input);
4112             call->del_req(valid_length_test_input);
4113             if (valid_length_test->find_int_con(1) == 0) {
4114               required_outcnt--;
4115             }
4116             dead_nodes.push(valid_length_test);
4117             assert(n->outcnt() == required_outcnt, "malformed control flow");
4118             continue;
4119           }
4120         }
4121       }
4122 
4123       // Recheck with a better notion of 'required_outcnt'
4124       if (n->outcnt() != required_outcnt) {
4125         record_method_not_compilable("malformed control flow");
4126         return true;            // Not all targets reachable!
4127       }
4128     } else if (n->is_PCTable() && n->in(0) && n->in(0)->in(0) && n->in(0)->in(0)->is_Call()) {
4129       CallNode* call = n->in(0)->in(0)->as_Call();
4130       if (call->entry_point() == OptoRuntime::new_array_Java() ||
4131           call->entry_point() == OptoRuntime::new_array_nozero_Java()) {
4132         assert(call->is_CallStaticJava(), "static call expected");
4133         assert(call->req() == call->jvms()->endoff() + 1, "missing extra input");
4134         uint valid_length_test_input = call->req() - 1;
4135         dead_nodes.push(call->in(valid_length_test_input));
4136         call->del_req(valid_length_test_input); // valid length test useless now
4137       }
4138     }
4139     // Check that I actually visited all kids.  Unreached kids
4140     // must be infinite loops.
4141     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
4142       if (!frc._visited.test(n->fast_out(j)->_idx)) {
4143         record_method_not_compilable("infinite loop");
4144         return true;            // Found unvisited kid; must be unreach
4145       }
4146 
4147     // Here so verification code in final_graph_reshaping_walk()
4148     // always see an OuterStripMinedLoopEnd
4149     if (n->is_OuterStripMinedLoopEnd() || n->is_LongCountedLoopEnd()) {
4150       IfNode* init_iff = n->as_If();
4151       Node* iff = new IfNode(init_iff->in(0), init_iff->in(1), init_iff->_prob, init_iff->_fcnt);
4152       n->subsume_by(iff, this);
4153     }
4154   }
4155 
4156   while (dead_nodes.size() > 0) {
4157     Node* m = dead_nodes.pop();
4158     if (m->outcnt() == 0 && m != top()) {
4159       for (uint j = 0; j < m->req(); j++) {
4160         Node* in = m->in(j);
4161         if (in != nullptr) {
4162           dead_nodes.push(in);
4163         }
4164       }
4165       m->disconnect_inputs(this);
4166     }
4167   }
4168 
4169   set_java_calls(frc.get_java_call_count());
4170   set_inner_loops(frc.get_inner_loop_count());
4171 
4172   // No infinite loops, no reason to bail out.
4173   return false;
4174 }
4175 
4176 //-----------------------------too_many_traps----------------------------------
4177 // Report if there are too many traps at the current method and bci.
4178 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
4179 bool Compile::too_many_traps(ciMethod* method,
4180                              int bci,
4181                              Deoptimization::DeoptReason reason) {
4182   if (method->has_trap_at(bci)) {
4183     return true;
4184   }
4185   if (PreloadReduceTraps && for_preload()) {
4186     // Preload code should not have traps, if possible.
4187     return true;
4188   }
4189   ciMethodData* md = method->method_data();
4190   if (md->is_empty()) {
4191     // Assume the trap has not occurred, or that it occurred only
4192     // because of a transient condition during start-up in the interpreter.
4193     return false;
4194   }
4195   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : nullptr;
4196   if (md->has_trap_at(bci, m, reason) != 0) {
4197     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
4198     // Also, if there are multiple reasons, or if there is no per-BCI record,
4199     // assume the worst.
4200     if (log())
4201       log()->elem("observe trap='%s' count='%d'",
4202                   Deoptimization::trap_reason_name(reason),
4203                   md->trap_count(reason));
4204     return true;
4205   } else {
4206     // Ignore method/bci and see if there have been too many globally.
4207     return too_many_traps(reason, md);
4208   }
4209 }
4210 
4211 // Less-accurate variant which does not require a method and bci.
4212 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
4213                              ciMethodData* logmd) {
4214   if (PreloadReduceTraps && for_preload()) {
4215     // Preload code should not have traps, if possible.
4216     return true;
4217   }
4218   if (trap_count(reason) >= Deoptimization::per_method_trap_limit(reason)) {
4219     // Too many traps globally.
4220     // Note that we use cumulative trap_count, not just md->trap_count.
4221     if (log()) {
4222       int mcount = (logmd == nullptr)? -1: (int)logmd->trap_count(reason);
4223       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
4224                   Deoptimization::trap_reason_name(reason),
4225                   mcount, trap_count(reason));
4226     }
4227     return true;
4228   } else {
4229     // The coast is clear.
4230     return false;
4231   }
4232 }
4233 
4234 //--------------------------too_many_recompiles--------------------------------
4235 // Report if there are too many recompiles at the current method and bci.
4236 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
4237 // Is not eager to return true, since this will cause the compiler to use
4238 // Action_none for a trap point, to avoid too many recompilations.
4239 bool Compile::too_many_recompiles(ciMethod* method,
4240                                   int bci,
4241                                   Deoptimization::DeoptReason reason) {
4242   ciMethodData* md = method->method_data();
4243   if (md->is_empty()) {
4244     // Assume the trap has not occurred, or that it occurred only
4245     // because of a transient condition during start-up in the interpreter.
4246     return false;
4247   }
4248   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
4249   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
4250   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
4251   Deoptimization::DeoptReason per_bc_reason
4252     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
4253   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : nullptr;
4254   if ((per_bc_reason == Deoptimization::Reason_none
4255        || md->has_trap_at(bci, m, reason) != 0)
4256       // The trap frequency measure we care about is the recompile count:
4257       && md->trap_recompiled_at(bci, m)
4258       && md->overflow_recompile_count() >= bc_cutoff) {
4259     // Do not emit a trap here if it has already caused recompilations.
4260     // Also, if there are multiple reasons, or if there is no per-BCI record,
4261     // assume the worst.
4262     if (log())
4263       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
4264                   Deoptimization::trap_reason_name(reason),
4265                   md->trap_count(reason),
4266                   md->overflow_recompile_count());
4267     return true;
4268   } else if (trap_count(reason) != 0
4269              && decompile_count() >= m_cutoff) {
4270     // Too many recompiles globally, and we have seen this sort of trap.
4271     // Use cumulative decompile_count, not just md->decompile_count.
4272     if (log())
4273       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
4274                   Deoptimization::trap_reason_name(reason),
4275                   md->trap_count(reason), trap_count(reason),
4276                   md->decompile_count(), decompile_count());
4277     return true;
4278   } else {
4279     // The coast is clear.
4280     return false;
4281   }
4282 }
4283 
4284 // Compute when not to trap. Used by matching trap based nodes and
4285 // NullCheck optimization.
4286 void Compile::set_allowed_deopt_reasons() {
4287   _allowed_reasons = 0;
4288   if (is_method_compilation()) {
4289     for (int rs = (int)Deoptimization::Reason_none+1; rs < Compile::trapHistLength; rs++) {
4290       assert(rs < BitsPerInt, "recode bit map");
4291       if (!too_many_traps((Deoptimization::DeoptReason) rs)) {
4292         _allowed_reasons |= nth_bit(rs);
4293       }
4294     }
4295   }
4296 }
4297 
4298 bool Compile::needs_clinit_barrier(ciMethod* method, ciMethod* accessing_method) {
4299   return method->is_static() && needs_clinit_barrier(method->holder(), accessing_method);
4300 }
4301 
4302 bool Compile::needs_clinit_barrier(ciField* field, ciMethod* accessing_method) {
4303   return field->is_static() && needs_clinit_barrier(field->holder(), accessing_method);
4304 }
4305 
4306 bool Compile::needs_clinit_barrier(ciInstanceKlass* holder, ciMethod* accessing_method) {
4307   if (holder->is_initialized() && !do_clinit_barriers()) {
4308     return false;
4309   }
4310   if (holder->is_being_initialized() || do_clinit_barriers()) {
4311     if (accessing_method->holder() == holder) {
4312       // Access inside a class. The barrier can be elided when access happens in <clinit>,
4313       // <init>, or a static method. In all those cases, there was an initialization
4314       // barrier on the holder klass passed.
4315       if (accessing_method->is_static_initializer() ||
4316           accessing_method->is_object_initializer() ||
4317           accessing_method->is_static()) {
4318         return false;
4319       }
4320     } else if (accessing_method->holder()->is_subclass_of(holder)) {
4321       // Access from a subclass. The barrier can be elided only when access happens in <clinit>.
4322       // In case of <init> or a static method, the barrier is on the subclass is not enough:
4323       // child class can become fully initialized while its parent class is still being initialized.
4324       if (accessing_method->is_static_initializer()) {
4325         return false;
4326       }
4327     }
4328     ciMethod* root = method(); // the root method of compilation
4329     if (root != accessing_method) {
4330       return needs_clinit_barrier(holder, root); // check access in the context of compilation root
4331     }
4332   }
4333   return true;
4334 }
4335 
4336 #ifndef PRODUCT
4337 //------------------------------verify_bidirectional_edges---------------------
4338 // For each input edge to a node (ie - for each Use-Def edge), verify that
4339 // there is a corresponding Def-Use edge.
4340 void Compile::verify_bidirectional_edges(Unique_Node_List& visited, const Unique_Node_List* root_and_safepoints) const {
4341   // Allocate stack of size C->live_nodes()/16 to avoid frequent realloc
4342   uint stack_size = live_nodes() >> 4;
4343   Node_List nstack(MAX2(stack_size, (uint) OptoNodeListSize));
4344   if (root_and_safepoints != nullptr) {
4345     assert(root_and_safepoints->member(_root), "root is not in root_and_safepoints");
4346     for (uint i = 0, limit = root_and_safepoints->size(); i < limit; i++) {
4347       Node* root_or_safepoint = root_and_safepoints->at(i);
4348       // If the node is a safepoint, let's check if it still has a control input
4349       // Lack of control input signifies that this node was killed by CCP or
4350       // recursively by remove_globally_dead_node and it shouldn't be a starting
4351       // point.
4352       if (!root_or_safepoint->is_SafePoint() || root_or_safepoint->in(0) != nullptr) {
4353         nstack.push(root_or_safepoint);
4354       }
4355     }
4356   } else {
4357     nstack.push(_root);
4358   }
4359 
4360   while (nstack.size() > 0) {
4361     Node* n = nstack.pop();
4362     if (visited.member(n)) {
4363       continue;
4364     }
4365     visited.push(n);
4366 
4367     // Walk over all input edges, checking for correspondence
4368     uint length = n->len();
4369     for (uint i = 0; i < length; i++) {
4370       Node* in = n->in(i);
4371       if (in != nullptr && !visited.member(in)) {
4372         nstack.push(in); // Put it on stack
4373       }
4374       if (in != nullptr && !in->is_top()) {
4375         // Count instances of `next`
4376         int cnt = 0;
4377         for (uint idx = 0; idx < in->_outcnt; idx++) {
4378           if (in->_out[idx] == n) {
4379             cnt++;
4380           }
4381         }
4382         assert(cnt > 0, "Failed to find Def-Use edge.");
4383         // Check for duplicate edges
4384         // walk the input array downcounting the input edges to n
4385         for (uint j = 0; j < length; j++) {
4386           if (n->in(j) == in) {
4387             cnt--;
4388           }
4389         }
4390         assert(cnt == 0, "Mismatched edge count.");
4391       } else if (in == nullptr) {
4392         assert(i == 0 || i >= n->req() ||
4393                n->is_Region() || n->is_Phi() || n->is_ArrayCopy() ||
4394                (n->is_Unlock() && i == (n->req() - 1)) ||
4395                (n->is_MemBar() && i == 5), // the precedence edge to a membar can be removed during macro node expansion
4396               "only region, phi, arraycopy, unlock or membar nodes have null data edges");
4397       } else {
4398         assert(in->is_top(), "sanity");
4399         // Nothing to check.
4400       }
4401     }
4402   }
4403 }
4404 
4405 //------------------------------verify_graph_edges---------------------------
4406 // Walk the Graph and verify that there is a one-to-one correspondence
4407 // between Use-Def edges and Def-Use edges in the graph.
4408 void Compile::verify_graph_edges(bool no_dead_code, const Unique_Node_List* root_and_safepoints) const {
4409   if (VerifyGraphEdges) {
4410     Unique_Node_List visited;
4411 
4412     // Call graph walk to check edges
4413     verify_bidirectional_edges(visited, root_and_safepoints);
4414     if (no_dead_code) {
4415       // Now make sure that no visited node is used by an unvisited node.
4416       bool dead_nodes = false;
4417       Unique_Node_List checked;
4418       while (visited.size() > 0) {
4419         Node* n = visited.pop();
4420         checked.push(n);
4421         for (uint i = 0; i < n->outcnt(); i++) {
4422           Node* use = n->raw_out(i);
4423           if (checked.member(use))  continue;  // already checked
4424           if (visited.member(use))  continue;  // already in the graph
4425           if (use->is_Con())        continue;  // a dead ConNode is OK
4426           // At this point, we have found a dead node which is DU-reachable.
4427           if (!dead_nodes) {
4428             tty->print_cr("*** Dead nodes reachable via DU edges:");
4429             dead_nodes = true;
4430           }
4431           use->dump(2);
4432           tty->print_cr("---");
4433           checked.push(use);  // No repeats; pretend it is now checked.
4434         }
4435       }
4436       assert(!dead_nodes, "using nodes must be reachable from root");
4437     }
4438   }
4439 }
4440 #endif
4441 
4442 // The Compile object keeps track of failure reasons separately from the ciEnv.
4443 // This is required because there is not quite a 1-1 relation between the
4444 // ciEnv and its compilation task and the Compile object.  Note that one
4445 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
4446 // to backtrack and retry without subsuming loads.  Other than this backtracking
4447 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
4448 // by the logic in C2Compiler.
4449 void Compile::record_failure(const char* reason DEBUG_ONLY(COMMA bool allow_multiple_failures)) {
4450   if (log() != nullptr) {
4451     log()->elem("failure reason='%s' phase='compile'", reason);
4452   }
4453   if (_failure_reason.get() == nullptr) {
4454     // Record the first failure reason.
4455     _failure_reason.set(reason);
4456     if (CaptureBailoutInformation) {
4457       _first_failure_details = new CompilationFailureInfo(reason);
4458     }
4459   } else {
4460     assert(!StressBailout || allow_multiple_failures, "should have handled previous failure.");
4461   }
4462 
4463   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
4464     C->print_method(PHASE_FAILURE, 1);
4465   }
4466   _root = nullptr;  // flush the graph, too
4467 }
4468 
4469 Compile::TracePhase::TracePhase(const char* name, PhaseTraceId id)
4470   : TraceTime(name, &Phase::timers[id], CITime, CITimeVerbose),
4471     _compile(Compile::current()),
4472     _log(nullptr),
4473     _dolog(CITimeVerbose)
4474 {
4475   assert(_compile != nullptr, "sanity check");
4476   assert(id != PhaseTraceId::_t_none, "Don't use none");
4477   if (_dolog) {
4478     _log = _compile->log();
4479   }
4480   if (_log != nullptr) {
4481     _log->begin_head("phase name='%s' nodes='%d' live='%d'", phase_name(), _compile->unique(), _compile->live_nodes());
4482     _log->stamp();
4483     _log->end_head();
4484   }
4485 
4486   // Inform memory statistic, if enabled
4487   if (CompilationMemoryStatistic::enabled()) {
4488     CompilationMemoryStatistic::on_phase_start((int)id, name);
4489   }
4490 }
4491 
4492 Compile::TracePhase::TracePhase(PhaseTraceId id)
4493   : TracePhase(Phase::get_phase_trace_id_text(id), id) {}
4494 
4495 Compile::TracePhase::~TracePhase() {
4496 
4497   // Inform memory statistic, if enabled
4498   if (CompilationMemoryStatistic::enabled()) {
4499     CompilationMemoryStatistic::on_phase_end();
4500   }
4501 
4502   if (_compile->failing_internal()) {
4503     if (_log != nullptr) {
4504       _log->done("phase");
4505     }
4506     return; // timing code, not stressing bailouts.
4507   }
4508 #ifdef ASSERT
4509   if (PrintIdealNodeCount) {
4510     tty->print_cr("phase name='%s' nodes='%d' live='%d' live_graph_walk='%d'",
4511                   phase_name(), _compile->unique(), _compile->live_nodes(), _compile->count_live_nodes_by_graph_walk());
4512   }
4513 
4514   if (VerifyIdealNodeCount) {
4515     _compile->print_missing_nodes();
4516   }
4517 #endif
4518 
4519   if (_log != nullptr) {
4520     _log->done("phase name='%s' nodes='%d' live='%d'", phase_name(), _compile->unique(), _compile->live_nodes());
4521   }
4522 }
4523 
4524 //----------------------------static_subtype_check-----------------------------
4525 // Shortcut important common cases when superklass is exact:
4526 // (0) superklass is java.lang.Object (can occur in reflective code)
4527 // (1) subklass is already limited to a subtype of superklass => always ok
4528 // (2) subklass does not overlap with superklass => always fail
4529 // (3) superklass has NO subtypes and we can check with a simple compare.
4530 Compile::SubTypeCheckResult Compile::static_subtype_check(const TypeKlassPtr* superk, const TypeKlassPtr* subk, bool skip) {
4531   if (skip) {
4532     return SSC_full_test;       // Let caller generate the general case.
4533   }
4534 
4535   if (subk->is_java_subtype_of(superk)) {
4536     return SSC_always_true; // (0) and (1)  this test cannot fail
4537   }
4538 
4539   if (!subk->maybe_java_subtype_of(superk)) {
4540     return SSC_always_false; // (2) true path dead; no dynamic test needed
4541   }
4542 
4543   const Type* superelem = superk;
4544   if (superk->isa_aryklassptr()) {
4545     int ignored;
4546     superelem = superk->is_aryklassptr()->base_element_type(ignored);
4547   }
4548 
4549   if (superelem->isa_instklassptr()) {
4550     ciInstanceKlass* ik = superelem->is_instklassptr()->instance_klass();
4551     if (!ik->has_subklass()) {
4552       if (!ik->is_final()) {
4553         // Add a dependency if there is a chance of a later subclass.
4554         dependencies()->assert_leaf_type(ik);
4555       }
4556       if (!superk->maybe_java_subtype_of(subk)) {
4557         return SSC_always_false;
4558       }
4559       return SSC_easy_test;     // (3) caller can do a simple ptr comparison
4560     }
4561   } else {
4562     // A primitive array type has no subtypes.
4563     return SSC_easy_test;       // (3) caller can do a simple ptr comparison
4564   }
4565 
4566   return SSC_full_test;
4567 }
4568 
4569 Node* Compile::conv_I2X_index(PhaseGVN* phase, Node* idx, const TypeInt* sizetype, Node* ctrl) {
4570 #ifdef _LP64
4571   // The scaled index operand to AddP must be a clean 64-bit value.
4572   // Java allows a 32-bit int to be incremented to a negative
4573   // value, which appears in a 64-bit register as a large
4574   // positive number.  Using that large positive number as an
4575   // operand in pointer arithmetic has bad consequences.
4576   // On the other hand, 32-bit overflow is rare, and the possibility
4577   // can often be excluded, if we annotate the ConvI2L node with
4578   // a type assertion that its value is known to be a small positive
4579   // number.  (The prior range check has ensured this.)
4580   // This assertion is used by ConvI2LNode::Ideal.
4581   int index_max = max_jint - 1;  // array size is max_jint, index is one less
4582   if (sizetype != nullptr && sizetype->_hi > 0) {
4583     index_max = sizetype->_hi - 1;
4584   }
4585   const TypeInt* iidxtype = TypeInt::make(0, index_max, Type::WidenMax);
4586   idx = constrained_convI2L(phase, idx, iidxtype, ctrl);
4587 #endif
4588   return idx;
4589 }
4590 
4591 // Convert integer value to a narrowed long type dependent on ctrl (for example, a range check)
4592 Node* Compile::constrained_convI2L(PhaseGVN* phase, Node* value, const TypeInt* itype, Node* ctrl, bool carry_dependency) {
4593   if (ctrl != nullptr) {
4594     // Express control dependency by a CastII node with a narrow type.
4595     // Make the CastII node dependent on the control input to prevent the narrowed ConvI2L
4596     // node from floating above the range check during loop optimizations. Otherwise, the
4597     // ConvI2L node may be eliminated independently of the range check, causing the data path
4598     // to become TOP while the control path is still there (although it's unreachable).
4599     value = new CastIINode(ctrl, value, itype, carry_dependency ? ConstraintCastNode::DependencyType::NonFloatingNarrowing : ConstraintCastNode::DependencyType::FloatingNarrowing, true /* range check dependency */);
4600     value = phase->transform(value);
4601   }
4602   const TypeLong* ltype = TypeLong::make(itype->_lo, itype->_hi, itype->_widen);
4603   return phase->transform(new ConvI2LNode(value, ltype));
4604 }
4605 
4606 void Compile::dump_print_inlining() {
4607   inline_printer()->print_on(tty);
4608 }
4609 
4610 void Compile::log_late_inline(CallGenerator* cg) {
4611   if (log() != nullptr) {
4612     log()->head("late_inline method='%d' inline_id='" JLONG_FORMAT "'", log()->identify(cg->method()),
4613                 cg->unique_id());
4614     JVMState* p = cg->call_node()->jvms();
4615     while (p != nullptr) {
4616       log()->elem("jvms bci='%d' method='%d'", p->bci(), log()->identify(p->method()));
4617       p = p->caller();
4618     }
4619     log()->tail("late_inline");
4620   }
4621 }
4622 
4623 void Compile::log_late_inline_failure(CallGenerator* cg, const char* msg) {
4624   log_late_inline(cg);
4625   if (log() != nullptr) {
4626     log()->inline_fail(msg);
4627   }
4628 }
4629 
4630 void Compile::log_inline_id(CallGenerator* cg) {
4631   if (log() != nullptr) {
4632     // The LogCompilation tool needs a unique way to identify late
4633     // inline call sites. This id must be unique for this call site in
4634     // this compilation. Try to have it unique across compilations as
4635     // well because it can be convenient when grepping through the log
4636     // file.
4637     // Distinguish OSR compilations from others in case CICountOSR is
4638     // on.
4639     jlong id = ((jlong)unique()) + (((jlong)compile_id()) << 33) + (CICountOSR && is_osr_compilation() ? ((jlong)1) << 32 : 0);
4640     cg->set_unique_id(id);
4641     log()->elem("inline_id id='" JLONG_FORMAT "'", id);
4642   }
4643 }
4644 
4645 void Compile::log_inline_failure(const char* msg) {
4646   if (C->log() != nullptr) {
4647     C->log()->inline_fail(msg);
4648   }
4649 }
4650 
4651 
4652 // Dump inlining replay data to the stream.
4653 // Don't change thread state and acquire any locks.
4654 void Compile::dump_inline_data(outputStream* out) {
4655   InlineTree* inl_tree = ilt();
4656   if (inl_tree != nullptr) {
4657     out->print(" inline %d", inl_tree->count());
4658     inl_tree->dump_replay_data(out);
4659   }
4660 }
4661 
4662 void Compile::dump_inline_data_reduced(outputStream* out) {
4663   assert(ReplayReduce, "");
4664 
4665   InlineTree* inl_tree = ilt();
4666   if (inl_tree == nullptr) {
4667     return;
4668   }
4669   // Enable iterative replay file reduction
4670   // Output "compile" lines for depth 1 subtrees,
4671   // simulating that those trees were compiled
4672   // instead of inlined.
4673   for (int i = 0; i < inl_tree->subtrees().length(); ++i) {
4674     InlineTree* sub = inl_tree->subtrees().at(i);
4675     if (sub->inline_level() != 1) {
4676       continue;
4677     }
4678 
4679     ciMethod* method = sub->method();
4680     int entry_bci = -1;
4681     int comp_level = env()->task()->comp_level();
4682     out->print("compile ");
4683     method->dump_name_as_ascii(out);
4684     out->print(" %d %d", entry_bci, comp_level);
4685     out->print(" inline %d", sub->count());
4686     sub->dump_replay_data(out, -1);
4687     out->cr();
4688   }
4689 }
4690 
4691 int Compile::cmp_expensive_nodes(Node* n1, Node* n2) {
4692   if (n1->Opcode() < n2->Opcode())      return -1;
4693   else if (n1->Opcode() > n2->Opcode()) return 1;
4694 
4695   assert(n1->req() == n2->req(), "can't compare %s nodes: n1->req() = %d, n2->req() = %d", NodeClassNames[n1->Opcode()], n1->req(), n2->req());
4696   for (uint i = 1; i < n1->req(); i++) {
4697     if (n1->in(i) < n2->in(i))      return -1;
4698     else if (n1->in(i) > n2->in(i)) return 1;
4699   }
4700 
4701   return 0;
4702 }
4703 
4704 int Compile::cmp_expensive_nodes(Node** n1p, Node** n2p) {
4705   Node* n1 = *n1p;
4706   Node* n2 = *n2p;
4707 
4708   return cmp_expensive_nodes(n1, n2);
4709 }
4710 
4711 void Compile::sort_expensive_nodes() {
4712   if (!expensive_nodes_sorted()) {
4713     _expensive_nodes.sort(cmp_expensive_nodes);
4714   }
4715 }
4716 
4717 bool Compile::expensive_nodes_sorted() const {
4718   for (int i = 1; i < _expensive_nodes.length(); i++) {
4719     if (cmp_expensive_nodes(_expensive_nodes.adr_at(i), _expensive_nodes.adr_at(i-1)) < 0) {
4720       return false;
4721     }
4722   }
4723   return true;
4724 }
4725 
4726 bool Compile::should_optimize_expensive_nodes(PhaseIterGVN &igvn) {
4727   if (_expensive_nodes.length() == 0) {
4728     return false;
4729   }
4730 
4731   assert(OptimizeExpensiveOps, "optimization off?");
4732 
4733   // Take this opportunity to remove dead nodes from the list
4734   int j = 0;
4735   for (int i = 0; i < _expensive_nodes.length(); i++) {
4736     Node* n = _expensive_nodes.at(i);
4737     if (!n->is_unreachable(igvn)) {
4738       assert(n->is_expensive(), "should be expensive");
4739       _expensive_nodes.at_put(j, n);
4740       j++;
4741     }
4742   }
4743   _expensive_nodes.trunc_to(j);
4744 
4745   // Then sort the list so that similar nodes are next to each other
4746   // and check for at least two nodes of identical kind with same data
4747   // inputs.
4748   sort_expensive_nodes();
4749 
4750   for (int i = 0; i < _expensive_nodes.length()-1; i++) {
4751     if (cmp_expensive_nodes(_expensive_nodes.adr_at(i), _expensive_nodes.adr_at(i+1)) == 0) {
4752       return true;
4753     }
4754   }
4755 
4756   return false;
4757 }
4758 
4759 void Compile::cleanup_expensive_nodes(PhaseIterGVN &igvn) {
4760   if (_expensive_nodes.length() == 0) {
4761     return;
4762   }
4763 
4764   assert(OptimizeExpensiveOps, "optimization off?");
4765 
4766   // Sort to bring similar nodes next to each other and clear the
4767   // control input of nodes for which there's only a single copy.
4768   sort_expensive_nodes();
4769 
4770   int j = 0;
4771   int identical = 0;
4772   int i = 0;
4773   bool modified = false;
4774   for (; i < _expensive_nodes.length()-1; i++) {
4775     assert(j <= i, "can't write beyond current index");
4776     if (_expensive_nodes.at(i)->Opcode() == _expensive_nodes.at(i+1)->Opcode()) {
4777       identical++;
4778       _expensive_nodes.at_put(j++, _expensive_nodes.at(i));
4779       continue;
4780     }
4781     if (identical > 0) {
4782       _expensive_nodes.at_put(j++, _expensive_nodes.at(i));
4783       identical = 0;
4784     } else {
4785       Node* n = _expensive_nodes.at(i);
4786       igvn.replace_input_of(n, 0, nullptr);
4787       igvn.hash_insert(n);
4788       modified = true;
4789     }
4790   }
4791   if (identical > 0) {
4792     _expensive_nodes.at_put(j++, _expensive_nodes.at(i));
4793   } else if (_expensive_nodes.length() >= 1) {
4794     Node* n = _expensive_nodes.at(i);
4795     igvn.replace_input_of(n, 0, nullptr);
4796     igvn.hash_insert(n);
4797     modified = true;
4798   }
4799   _expensive_nodes.trunc_to(j);
4800   if (modified) {
4801     igvn.optimize();
4802   }
4803 }
4804 
4805 void Compile::add_expensive_node(Node * n) {
4806   assert(!_expensive_nodes.contains(n), "duplicate entry in expensive list");
4807   assert(n->is_expensive(), "expensive nodes with non-null control here only");
4808   assert(!n->is_CFG() && !n->is_Mem(), "no cfg or memory nodes here");
4809   if (OptimizeExpensiveOps) {
4810     _expensive_nodes.append(n);
4811   } else {
4812     // Clear control input and let IGVN optimize expensive nodes if
4813     // OptimizeExpensiveOps is off.
4814     n->set_req(0, nullptr);
4815   }
4816 }
4817 
4818 /**
4819  * Track coarsened Lock and Unlock nodes.
4820  */
4821 
4822 class Lock_List : public Node_List {
4823   uint _origin_cnt;
4824 public:
4825   Lock_List(Arena *a, uint cnt) : Node_List(a), _origin_cnt(cnt) {}
4826   uint origin_cnt() const { return _origin_cnt; }
4827 };
4828 
4829 void Compile::add_coarsened_locks(GrowableArray<AbstractLockNode*>& locks) {
4830   int length = locks.length();
4831   if (length > 0) {
4832     // Have to keep this list until locks elimination during Macro nodes elimination.
4833     Lock_List* locks_list = new (comp_arena()) Lock_List(comp_arena(), length);
4834     AbstractLockNode* alock = locks.at(0);
4835     BoxLockNode* box = alock->box_node()->as_BoxLock();
4836     for (int i = 0; i < length; i++) {
4837       AbstractLockNode* lock = locks.at(i);
4838       assert(lock->is_coarsened(), "expecting only coarsened AbstractLock nodes, but got '%s'[%d] node", lock->Name(), lock->_idx);
4839       locks_list->push(lock);
4840       BoxLockNode* this_box = lock->box_node()->as_BoxLock();
4841       if (this_box != box) {
4842         // Locking regions (BoxLock) could be Unbalanced here:
4843         //  - its coarsened locks were eliminated in earlier
4844         //    macro nodes elimination followed by loop unroll
4845         //  - it is OSR locking region (no Lock node)
4846         // Preserve Unbalanced status in such cases.
4847         if (!this_box->is_unbalanced()) {
4848           this_box->set_coarsened();
4849         }
4850         if (!box->is_unbalanced()) {
4851           box->set_coarsened();
4852         }
4853       }
4854     }
4855     _coarsened_locks.append(locks_list);
4856   }
4857 }
4858 
4859 void Compile::remove_useless_coarsened_locks(Unique_Node_List& useful) {
4860   int count = coarsened_count();
4861   for (int i = 0; i < count; i++) {
4862     Node_List* locks_list = _coarsened_locks.at(i);
4863     for (uint j = 0; j < locks_list->size(); j++) {
4864       Node* lock = locks_list->at(j);
4865       assert(lock->is_AbstractLock(), "sanity");
4866       if (!useful.member(lock)) {
4867         locks_list->yank(lock);
4868       }
4869     }
4870   }
4871 }
4872 
4873 void Compile::remove_coarsened_lock(Node* n) {
4874   if (n->is_AbstractLock()) {
4875     int count = coarsened_count();
4876     for (int i = 0; i < count; i++) {
4877       Node_List* locks_list = _coarsened_locks.at(i);
4878       locks_list->yank(n);
4879     }
4880   }
4881 }
4882 
4883 bool Compile::coarsened_locks_consistent() {
4884   int count = coarsened_count();
4885   for (int i = 0; i < count; i++) {
4886     bool unbalanced = false;
4887     bool modified = false; // track locks kind modifications
4888     Lock_List* locks_list = (Lock_List*)_coarsened_locks.at(i);
4889     uint size = locks_list->size();
4890     if (size == 0) {
4891       unbalanced = false; // All locks were eliminated - good
4892     } else if (size != locks_list->origin_cnt()) {
4893       unbalanced = true; // Some locks were removed from list
4894     } else {
4895       for (uint j = 0; j < size; j++) {
4896         Node* lock = locks_list->at(j);
4897         // All nodes in group should have the same state (modified or not)
4898         if (!lock->as_AbstractLock()->is_coarsened()) {
4899           if (j == 0) {
4900             // first on list was modified, the rest should be too for consistency
4901             modified = true;
4902           } else if (!modified) {
4903             // this lock was modified but previous locks on the list were not
4904             unbalanced = true;
4905             break;
4906           }
4907         } else if (modified) {
4908           // previous locks on list were modified but not this lock
4909           unbalanced = true;
4910           break;
4911         }
4912       }
4913     }
4914     if (unbalanced) {
4915       // unbalanced monitor enter/exit - only some [un]lock nodes were removed or modified
4916 #ifdef ASSERT
4917       if (PrintEliminateLocks) {
4918         tty->print_cr("=== unbalanced coarsened locks ===");
4919         for (uint l = 0; l < size; l++) {
4920           locks_list->at(l)->dump();
4921         }
4922       }
4923 #endif
4924       record_failure(C2Compiler::retry_no_locks_coarsening());
4925       return false;
4926     }
4927   }
4928   return true;
4929 }
4930 
4931 // Mark locking regions (identified by BoxLockNode) as unbalanced if
4932 // locks coarsening optimization removed Lock/Unlock nodes from them.
4933 // Such regions become unbalanced because coarsening only removes part
4934 // of Lock/Unlock nodes in region. As result we can't execute other
4935 // locks elimination optimizations which assume all code paths have
4936 // corresponding pair of Lock/Unlock nodes - they are balanced.
4937 void Compile::mark_unbalanced_boxes() const {
4938   int count = coarsened_count();
4939   for (int i = 0; i < count; i++) {
4940     Node_List* locks_list = _coarsened_locks.at(i);
4941     uint size = locks_list->size();
4942     if (size > 0) {
4943       AbstractLockNode* alock = locks_list->at(0)->as_AbstractLock();
4944       BoxLockNode* box = alock->box_node()->as_BoxLock();
4945       if (alock->is_coarsened()) {
4946         // coarsened_locks_consistent(), which is called before this method, verifies
4947         // that the rest of Lock/Unlock nodes on locks_list are also coarsened.
4948         assert(!box->is_eliminated(), "regions with coarsened locks should not be marked as eliminated");
4949         for (uint j = 1; j < size; j++) {
4950           assert(locks_list->at(j)->as_AbstractLock()->is_coarsened(), "only coarsened locks are expected here");
4951           BoxLockNode* this_box = locks_list->at(j)->as_AbstractLock()->box_node()->as_BoxLock();
4952           if (box != this_box) {
4953             assert(!this_box->is_eliminated(), "regions with coarsened locks should not be marked as eliminated");
4954             box->set_unbalanced();
4955             this_box->set_unbalanced();
4956           }
4957         }
4958       }
4959     }
4960   }
4961 }
4962 
4963 /**
4964  * Remove the speculative part of types and clean up the graph
4965  */
4966 void Compile::remove_speculative_types(PhaseIterGVN &igvn) {
4967   if (UseTypeSpeculation) {
4968     Unique_Node_List worklist;
4969     worklist.push(root());
4970     int modified = 0;
4971     // Go over all type nodes that carry a speculative type, drop the
4972     // speculative part of the type and enqueue the node for an igvn
4973     // which may optimize it out.
4974     for (uint next = 0; next < worklist.size(); ++next) {
4975       Node *n  = worklist.at(next);
4976       if (n->is_Type()) {
4977         TypeNode* tn = n->as_Type();
4978         const Type* t = tn->type();
4979         const Type* t_no_spec = t->remove_speculative();
4980         if (t_no_spec != t) {
4981           bool in_hash = igvn.hash_delete(n);
4982           assert(in_hash || n->hash() == Node::NO_HASH, "node should be in igvn hash table");
4983           tn->set_type(t_no_spec);
4984           igvn.hash_insert(n);
4985           igvn._worklist.push(n); // give it a chance to go away
4986           modified++;
4987         }
4988       }
4989       // Iterate over outs - endless loops is unreachable from below
4990       for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
4991         Node *m = n->fast_out(i);
4992         if (not_a_node(m)) {
4993           continue;
4994         }
4995         worklist.push(m);
4996       }
4997     }
4998     // Drop the speculative part of all types in the igvn's type table
4999     igvn.remove_speculative_types();
5000     if (modified > 0) {
5001       igvn.optimize();
5002       if (failing())  return;
5003     }
5004 #ifdef ASSERT
5005     // Verify that after the IGVN is over no speculative type has resurfaced
5006     worklist.clear();
5007     worklist.push(root());
5008     for (uint next = 0; next < worklist.size(); ++next) {
5009       Node *n  = worklist.at(next);
5010       const Type* t = igvn.type_or_null(n);
5011       assert((t == nullptr) || (t == t->remove_speculative()), "no more speculative types");
5012       if (n->is_Type()) {
5013         t = n->as_Type()->type();
5014         assert(t == t->remove_speculative(), "no more speculative types");
5015       }
5016       // Iterate over outs - endless loops is unreachable from below
5017       for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
5018         Node *m = n->fast_out(i);
5019         if (not_a_node(m)) {
5020           continue;
5021         }
5022         worklist.push(m);
5023       }
5024     }
5025     igvn.check_no_speculative_types();
5026 #endif
5027   }
5028 }
5029 
5030 // Auxiliary methods to support randomized stressing/fuzzing.
5031 
5032 void Compile::initialize_stress_seed(const DirectiveSet* directive) {
5033   if (FLAG_IS_DEFAULT(StressSeed) || (FLAG_IS_ERGO(StressSeed) && directive->RepeatCompilationOption)) {
5034     _stress_seed = static_cast<uint>(Ticks::now().nanoseconds());
5035     FLAG_SET_ERGO(StressSeed, _stress_seed);
5036   } else {
5037     _stress_seed = StressSeed;
5038   }
5039   if (_log != nullptr) {
5040     _log->elem("stress_test seed='%u'", _stress_seed);
5041   }
5042 }
5043 
5044 int Compile::random() {
5045   _stress_seed = os::next_random(_stress_seed);
5046   return static_cast<int>(_stress_seed);
5047 }
5048 
5049 // This method can be called the arbitrary number of times, with current count
5050 // as the argument. The logic allows selecting a single candidate from the
5051 // running list of candidates as follows:
5052 //    int count = 0;
5053 //    Cand* selected = null;
5054 //    while(cand = cand->next()) {
5055 //      if (randomized_select(++count)) {
5056 //        selected = cand;
5057 //      }
5058 //    }
5059 //
5060 // Including count equalizes the chances any candidate is "selected".
5061 // This is useful when we don't have the complete list of candidates to choose
5062 // from uniformly. In this case, we need to adjust the randomicity of the
5063 // selection, or else we will end up biasing the selection towards the latter
5064 // candidates.
5065 //
5066 // Quick back-envelope calculation shows that for the list of n candidates
5067 // the equal probability for the candidate to persist as "best" can be
5068 // achieved by replacing it with "next" k-th candidate with the probability
5069 // of 1/k. It can be easily shown that by the end of the run, the
5070 // probability for any candidate is converged to 1/n, thus giving the
5071 // uniform distribution among all the candidates.
5072 //
5073 // We don't care about the domain size as long as (RANDOMIZED_DOMAIN / count) is large.
5074 #define RANDOMIZED_DOMAIN_POW 29
5075 #define RANDOMIZED_DOMAIN (1 << RANDOMIZED_DOMAIN_POW)
5076 #define RANDOMIZED_DOMAIN_MASK ((1 << (RANDOMIZED_DOMAIN_POW + 1)) - 1)
5077 bool Compile::randomized_select(int count) {
5078   assert(count > 0, "only positive");
5079   return (random() & RANDOMIZED_DOMAIN_MASK) < (RANDOMIZED_DOMAIN / count);
5080 }
5081 
5082 #ifdef ASSERT
5083 // Failures are geometrically distributed with probability 1/StressBailoutMean.
5084 bool Compile::fail_randomly() {
5085   if ((random() % StressBailoutMean) != 0) {
5086     return false;
5087   }
5088   record_failure("StressBailout");
5089   return true;
5090 }
5091 
5092 bool Compile::failure_is_artificial() {
5093   return C->failure_reason_is("StressBailout");
5094 }
5095 #endif
5096 
5097 CloneMap&     Compile::clone_map()                 { return _clone_map; }
5098 void          Compile::set_clone_map(Dict* d)      { _clone_map._dict = d; }
5099 
5100 void NodeCloneInfo::dump_on(outputStream* st) const {
5101   st->print(" {%d:%d} ", idx(), gen());
5102 }
5103 
5104 void CloneMap::clone(Node* old, Node* nnn, int gen) {
5105   uint64_t val = value(old->_idx);
5106   NodeCloneInfo cio(val);
5107   assert(val != 0, "old node should be in the map");
5108   NodeCloneInfo cin(cio.idx(), gen + cio.gen());
5109   insert(nnn->_idx, cin.get());
5110 #ifndef PRODUCT
5111   if (is_debug()) {
5112     tty->print_cr("CloneMap::clone inserted node %d info {%d:%d} into CloneMap", nnn->_idx, cin.idx(), cin.gen());
5113   }
5114 #endif
5115 }
5116 
5117 void CloneMap::verify_insert_and_clone(Node* old, Node* nnn, int gen) {
5118   NodeCloneInfo cio(value(old->_idx));
5119   if (cio.get() == 0) {
5120     cio.set(old->_idx, 0);
5121     insert(old->_idx, cio.get());
5122 #ifndef PRODUCT
5123     if (is_debug()) {
5124       tty->print_cr("CloneMap::verify_insert_and_clone inserted node %d info {%d:%d} into CloneMap", old->_idx, cio.idx(), cio.gen());
5125     }
5126 #endif
5127   }
5128   clone(old, nnn, gen);
5129 }
5130 
5131 int CloneMap::max_gen() const {
5132   int g = 0;
5133   DictI di(_dict);
5134   for(; di.test(); ++di) {
5135     int t = gen(di._key);
5136     if (g < t) {
5137       g = t;
5138 #ifndef PRODUCT
5139       if (is_debug()) {
5140         tty->print_cr("CloneMap::max_gen() update max=%d from %d", g, _2_node_idx_t(di._key));
5141       }
5142 #endif
5143     }
5144   }
5145   return g;
5146 }
5147 
5148 void CloneMap::dump(node_idx_t key, outputStream* st) const {
5149   uint64_t val = value(key);
5150   if (val != 0) {
5151     NodeCloneInfo ni(val);
5152     ni.dump_on(st);
5153   }
5154 }
5155 
5156 void Compile::shuffle_macro_nodes() {
5157   shuffle_array(*C, _macro_nodes);
5158 }
5159 
5160 // Move Allocate nodes to the start of the list
5161 void Compile::sort_macro_nodes() {
5162   int count = macro_count();
5163   int allocates = 0;
5164   for (int i = 0; i < count; i++) {
5165     Node* n = macro_node(i);
5166     if (n->is_Allocate()) {
5167       if (i != allocates) {
5168         Node* tmp = macro_node(allocates);
5169         _macro_nodes.at_put(allocates, n);
5170         _macro_nodes.at_put(i, tmp);
5171       }
5172       allocates++;
5173     }
5174   }
5175 }
5176 
5177 void Compile::print_method(CompilerPhaseType compile_phase, int level, Node* n) {
5178   if (failing_internal()) { return; } // failing_internal to not stress bailouts from printing code.
5179   EventCompilerPhase event(UNTIMED);
5180   if (event.should_commit()) {
5181     CompilerEvent::PhaseEvent::post(event, C->_latest_stage_start_counter, compile_phase, C->_compile_id, level);
5182   }
5183 #ifndef PRODUCT
5184   ResourceMark rm;
5185   stringStream ss;
5186   ss.print_raw(CompilerPhaseTypeHelper::to_description(compile_phase));
5187   int iter = ++_igv_phase_iter[compile_phase];
5188   if (iter > 1) {
5189     ss.print(" %d", iter);
5190   }
5191   if (n != nullptr) {
5192     ss.print(": %d %s", n->_idx, NodeClassNames[n->Opcode()]);
5193     if (n->is_Call()) {
5194       CallNode* call = n->as_Call();
5195       if (call->_name != nullptr) {
5196         // E.g. uncommon traps etc.
5197         ss.print(" - %s", call->_name);
5198       } else if (call->is_CallJava()) {
5199         CallJavaNode* call_java = call->as_CallJava();
5200         if (call_java->method() != nullptr) {
5201           ss.print(" -");
5202           call_java->method()->print_short_name(&ss);
5203         }
5204       }
5205     }
5206   }
5207 
5208   const char* name = ss.as_string();
5209   if (should_print_igv(level)) {
5210     _igv_printer->print_graph(name);
5211   }
5212   if (should_print_phase(level)) {
5213     print_phase(name);
5214   }
5215   if (should_print_ideal_phase(compile_phase)) {
5216     print_ideal_ir(CompilerPhaseTypeHelper::to_name(compile_phase));
5217   }
5218 #endif
5219   C->_latest_stage_start_counter.stamp();
5220 }
5221 
5222 // Only used from CompileWrapper
5223 void Compile::begin_method() {
5224 #ifndef PRODUCT
5225   if (_method != nullptr && should_print_igv(1)) {
5226     _igv_printer->begin_method();
5227   }
5228 #endif
5229   C->_latest_stage_start_counter.stamp();
5230 }
5231 
5232 // Only used from CompileWrapper
5233 void Compile::end_method() {
5234   EventCompilerPhase event(UNTIMED);
5235   if (event.should_commit()) {
5236     CompilerEvent::PhaseEvent::post(event, C->_latest_stage_start_counter, PHASE_END, C->_compile_id, 1);
5237   }
5238 
5239 #ifndef PRODUCT
5240   if (_method != nullptr && should_print_igv(1)) {
5241     _igv_printer->end_method();
5242   }
5243 #endif
5244 }
5245 
5246 #ifndef PRODUCT
5247 bool Compile::should_print_phase(const int level) const {
5248   return PrintPhaseLevel >= 0 && directive()->PhasePrintLevelOption >= level &&
5249          _method != nullptr; // Do not print phases for stubs.
5250 }
5251 
5252 bool Compile::should_print_ideal_phase(CompilerPhaseType cpt) const {
5253   return _directive->should_print_ideal_phase(cpt);
5254 }
5255 
5256 void Compile::init_igv() {
5257   if (_igv_printer == nullptr) {
5258     _igv_printer = IdealGraphPrinter::printer();
5259     _igv_printer->set_compile(this);
5260   }
5261 }
5262 
5263 bool Compile::should_print_igv(const int level) {
5264   PRODUCT_RETURN_(return false;);
5265 
5266   if (PrintIdealGraphLevel < 0) { // disabled by the user
5267     return false;
5268   }
5269 
5270   bool need = directive()->IGVPrintLevelOption >= level;
5271   if (need) {
5272     Compile::init_igv();
5273   }
5274   return need;
5275 }
5276 
5277 IdealGraphPrinter* Compile::_debug_file_printer = nullptr;
5278 IdealGraphPrinter* Compile::_debug_network_printer = nullptr;
5279 
5280 // Called from debugger. Prints method to the default file with the default phase name.
5281 // This works regardless of any Ideal Graph Visualizer flags set or not.
5282 // Use in debugger (gdb/rr): p igv_print($sp, $fp, $pc).
5283 void igv_print(void* sp, void* fp, void* pc) {
5284   frame fr(sp, fp, pc);
5285   Compile::current()->igv_print_method_to_file(nullptr, false, &fr);
5286 }
5287 
5288 // Same as igv_print() above but with a specified phase name.
5289 void igv_print(const char* phase_name, void* sp, void* fp, void* pc) {
5290   frame fr(sp, fp, pc);
5291   Compile::current()->igv_print_method_to_file(phase_name, false, &fr);
5292 }
5293 
5294 // Called from debugger. Prints method with the default phase name to the default network or the one specified with
5295 // the network flags for the Ideal Graph Visualizer, or to the default file depending on the 'network' argument.
5296 // This works regardless of any Ideal Graph Visualizer flags set or not.
5297 // Use in debugger (gdb/rr): p igv_print(true, $sp, $fp, $pc).
5298 void igv_print(bool network, void* sp, void* fp, void* pc) {
5299   frame fr(sp, fp, pc);
5300   if (network) {
5301     Compile::current()->igv_print_method_to_network(nullptr, &fr);
5302   } else {
5303     Compile::current()->igv_print_method_to_file(nullptr, false, &fr);
5304   }
5305 }
5306 
5307 // Same as igv_print(bool network, ...) above but with a specified phase name.
5308 // Use in debugger (gdb/rr): p igv_print(true, "MyPhase", $sp, $fp, $pc).
5309 void igv_print(bool network, const char* phase_name, void* sp, void* fp, void* pc) {
5310   frame fr(sp, fp, pc);
5311   if (network) {
5312     Compile::current()->igv_print_method_to_network(phase_name, &fr);
5313   } else {
5314     Compile::current()->igv_print_method_to_file(phase_name, false, &fr);
5315   }
5316 }
5317 
5318 // Called from debugger. Normal write to the default _printer. Only works if Ideal Graph Visualizer printing flags are set.
5319 void igv_print_default() {
5320   Compile::current()->print_method(PHASE_DEBUG, 0);
5321 }
5322 
5323 // Called from debugger, especially when replaying a trace in which the program state cannot be altered like with rr replay.
5324 // A method is appended to an existing default file with the default phase name. This means that igv_append() must follow
5325 // an earlier igv_print(*) call which sets up the file. This works regardless of any Ideal Graph Visualizer flags set or not.
5326 // Use in debugger (gdb/rr): p igv_append($sp, $fp, $pc).
5327 void igv_append(void* sp, void* fp, void* pc) {
5328   frame fr(sp, fp, pc);
5329   Compile::current()->igv_print_method_to_file(nullptr, true, &fr);
5330 }
5331 
5332 // Same as igv_append(...) above but with a specified phase name.
5333 // Use in debugger (gdb/rr): p igv_append("MyPhase", $sp, $fp, $pc).
5334 void igv_append(const char* phase_name, void* sp, void* fp, void* pc) {
5335   frame fr(sp, fp, pc);
5336   Compile::current()->igv_print_method_to_file(phase_name, true, &fr);
5337 }
5338 
5339 void Compile::igv_print_method_to_file(const char* phase_name, bool append, const frame* fr) {
5340   const char* file_name = "custom_debug.xml";
5341   if (_debug_file_printer == nullptr) {
5342     _debug_file_printer = new IdealGraphPrinter(C, file_name, append);
5343   } else {
5344     _debug_file_printer->update_compiled_method(C->method());
5345   }
5346   tty->print_cr("Method %s to %s", append ? "appended" : "printed", file_name);
5347   _debug_file_printer->print_graph(phase_name, fr);
5348 }
5349 
5350 void Compile::igv_print_method_to_network(const char* phase_name, const frame* fr) {
5351   ResourceMark rm;
5352   GrowableArray<const Node*> empty_list;
5353   igv_print_graph_to_network(phase_name, empty_list, fr);
5354 }
5355 
5356 void Compile::igv_print_graph_to_network(const char* name, GrowableArray<const Node*>& visible_nodes, const frame* fr) {
5357   if (_debug_network_printer == nullptr) {
5358     _debug_network_printer = new IdealGraphPrinter(C);
5359   } else {
5360     _debug_network_printer->update_compiled_method(C->method());
5361   }
5362   tty->print_cr("Method printed over network stream to IGV");
5363   _debug_network_printer->print(name, C->root(), visible_nodes, fr);
5364 }
5365 #endif // !PRODUCT
5366 
5367 Node* Compile::narrow_value(BasicType bt, Node* value, const Type* type, PhaseGVN* phase, bool transform_res) {
5368   if (type != nullptr && phase->type(value)->higher_equal(type)) {
5369     return value;
5370   }
5371   Node* result = nullptr;
5372   if (bt == T_BYTE) {
5373     result = phase->transform(new LShiftINode(value, phase->intcon(24)));
5374     result = new RShiftINode(result, phase->intcon(24));
5375   } else if (bt == T_BOOLEAN) {
5376     result = new AndINode(value, phase->intcon(0xFF));
5377   } else if (bt == T_CHAR) {
5378     result = new AndINode(value,phase->intcon(0xFFFF));
5379   } else {
5380     assert(bt == T_SHORT, "unexpected narrow type");
5381     result = phase->transform(new LShiftINode(value, phase->intcon(16)));
5382     result = new RShiftINode(result, phase->intcon(16));
5383   }
5384   if (transform_res) {
5385     result = phase->transform(result);
5386   }
5387   return result;
5388 }
5389 
5390 void Compile::record_method_not_compilable_oom() {
5391   record_method_not_compilable(CompilationMemoryStatistic::failure_reason_memlimit());
5392 }
5393 
5394 #ifndef PRODUCT
5395 // Collects all the control inputs from nodes on the worklist and from their data dependencies
5396 static void find_candidate_control_inputs(Unique_Node_List& worklist, Unique_Node_List& candidates) {
5397   // Follow non-control edges until we reach CFG nodes
5398   for (uint i = 0; i < worklist.size(); i++) {
5399     const Node* n = worklist.at(i);
5400     for (uint j = 0; j < n->req(); j++) {
5401       Node* in = n->in(j);
5402       if (in == nullptr || in->is_Root()) {
5403         continue;
5404       }
5405       if (in->is_CFG()) {
5406         if (in->is_Call()) {
5407           // The return value of a call is only available if the call did not result in an exception
5408           Node* control_proj_use = in->as_Call()->proj_out(TypeFunc::Control)->unique_out();
5409           if (control_proj_use->is_Catch()) {
5410             Node* fall_through = control_proj_use->as_Catch()->proj_out(CatchProjNode::fall_through_index);
5411             candidates.push(fall_through);
5412             continue;
5413           }
5414         }
5415 
5416         if (in->is_Multi()) {
5417           // We got here by following data inputs so we should only have one control use
5418           // (no IfNode, etc)
5419           assert(!n->is_MultiBranch(), "unexpected node type: %s", n->Name());
5420           candidates.push(in->as_Multi()->proj_out(TypeFunc::Control));
5421         } else {
5422           candidates.push(in);
5423         }
5424       } else {
5425         worklist.push(in);
5426       }
5427     }
5428   }
5429 }
5430 
5431 // Returns the candidate node that is a descendant to all the other candidates
5432 static Node* pick_control(Unique_Node_List& candidates) {
5433   Unique_Node_List worklist;
5434   worklist.copy(candidates);
5435 
5436   // Traverse backwards through the CFG
5437   for (uint i = 0; i < worklist.size(); i++) {
5438     const Node* n = worklist.at(i);
5439     if (n->is_Root()) {
5440       continue;
5441     }
5442     for (uint j = 0; j < n->req(); j++) {
5443       // Skip backedge of loops to avoid cycles
5444       if (n->is_Loop() && j == LoopNode::LoopBackControl) {
5445         continue;
5446       }
5447 
5448       Node* pred = n->in(j);
5449       if (pred != nullptr && pred != n && pred->is_CFG()) {
5450         worklist.push(pred);
5451         // if pred is an ancestor of n, then pred is an ancestor to at least one candidate
5452         candidates.remove(pred);
5453       }
5454     }
5455   }
5456 
5457   assert(candidates.size() == 1, "unexpected control flow");
5458   return candidates.at(0);
5459 }
5460 
5461 // Initialize a parameter input for a debug print call, using a placeholder for jlong and jdouble
5462 static void debug_print_init_parm(Node* call, Node* parm, Node* half, int* pos) {
5463   call->init_req((*pos)++, parm);
5464   const BasicType bt = parm->bottom_type()->basic_type();
5465   if (bt == T_LONG || bt == T_DOUBLE) {
5466     call->init_req((*pos)++, half);
5467   }
5468 }
5469 
5470 Node* Compile::make_debug_print_call(const char* str, address call_addr, PhaseGVN* gvn,
5471                               Node* parm0, Node* parm1,
5472                               Node* parm2, Node* parm3,
5473                               Node* parm4, Node* parm5,
5474                               Node* parm6) const {
5475   Node* str_node = gvn->transform(new ConPNode(TypeRawPtr::make(((address) str))));
5476   const TypeFunc* type = OptoRuntime::debug_print_Type(parm0, parm1, parm2, parm3, parm4, parm5, parm6);
5477   Node* call = new CallLeafNode(type, call_addr, "debug_print", TypeRawPtr::BOTTOM);
5478 
5479   // find the most suitable control input
5480   Unique_Node_List worklist, candidates;
5481   if (parm0 != nullptr) { worklist.push(parm0);
5482   if (parm1 != nullptr) { worklist.push(parm1);
5483   if (parm2 != nullptr) { worklist.push(parm2);
5484   if (parm3 != nullptr) { worklist.push(parm3);
5485   if (parm4 != nullptr) { worklist.push(parm4);
5486   if (parm5 != nullptr) { worklist.push(parm5);
5487   if (parm6 != nullptr) { worklist.push(parm6);
5488   /* close each nested if ===> */  } } } } } } }
5489   find_candidate_control_inputs(worklist, candidates);
5490   Node* control = nullptr;
5491   if (candidates.size() == 0) {
5492     control = C->start()->proj_out(TypeFunc::Control);
5493   } else {
5494     control = pick_control(candidates);
5495   }
5496 
5497   // find all the previous users of the control we picked
5498   GrowableArray<Node*> users_of_control;
5499   for (DUIterator_Fast kmax, i = control->fast_outs(kmax); i < kmax; i++) {
5500     Node* use = control->fast_out(i);
5501     if (use->is_CFG() && use != control) {
5502       users_of_control.push(use);
5503     }
5504   }
5505 
5506   // we do not actually care about IO and memory as it uses neither
5507   call->init_req(TypeFunc::Control,   control);
5508   call->init_req(TypeFunc::I_O,       top());
5509   call->init_req(TypeFunc::Memory,    top());
5510   call->init_req(TypeFunc::FramePtr,  C->start()->proj_out(TypeFunc::FramePtr));
5511   call->init_req(TypeFunc::ReturnAdr, top());
5512 
5513   int pos = TypeFunc::Parms;
5514   call->init_req(pos++, str_node);
5515   if (parm0 != nullptr) { debug_print_init_parm(call, parm0, top(), &pos);
5516   if (parm1 != nullptr) { debug_print_init_parm(call, parm1, top(), &pos);
5517   if (parm2 != nullptr) { debug_print_init_parm(call, parm2, top(), &pos);
5518   if (parm3 != nullptr) { debug_print_init_parm(call, parm3, top(), &pos);
5519   if (parm4 != nullptr) { debug_print_init_parm(call, parm4, top(), &pos);
5520   if (parm5 != nullptr) { debug_print_init_parm(call, parm5, top(), &pos);
5521   if (parm6 != nullptr) { debug_print_init_parm(call, parm6, top(), &pos);
5522   /* close each nested if ===> */  } } } } } } }
5523   assert(call->in(call->req()-1) != nullptr, "must initialize all parms");
5524 
5525   call = gvn->transform(call);
5526   Node* call_control_proj = gvn->transform(new ProjNode(call, TypeFunc::Control));
5527 
5528   // rewire previous users to have the new call as control instead
5529   PhaseIterGVN* igvn = gvn->is_IterGVN();
5530   for (int i = 0; i < users_of_control.length(); i++) {
5531     Node* use = users_of_control.at(i);
5532     for (uint j = 0; j < use->req(); j++) {
5533       if (use->in(j) == control) {
5534         if (igvn != nullptr) {
5535           igvn->replace_input_of(use, j, call_control_proj);
5536         } else {
5537           gvn->hash_delete(use);
5538           use->set_req(j, call_control_proj);
5539           gvn->hash_insert(use);
5540         }
5541       }
5542     }
5543   }
5544 
5545   return call;
5546 }
5547 #endif // !PRODUCT