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/reachability.hpp"
  78 #include "opto/rootnode.hpp"
  79 #include "opto/runtime.hpp"
  80 #include "opto/stringopts.hpp"
  81 #include "opto/type.hpp"
  82 #include "opto/vector.hpp"
  83 #include "opto/vectornode.hpp"
  84 #include "runtime/globals_extension.hpp"
  85 #include "runtime/sharedRuntime.hpp"
  86 #include "runtime/signature.hpp"
  87 #include "runtime/stubRoutines.hpp"
  88 #include "runtime/timer.hpp"
  89 #include "utilities/align.hpp"
  90 #include "utilities/copy.hpp"
  91 #include "utilities/hashTable.hpp"
  92 #include "utilities/macros.hpp"
  93 
  94 // -------------------- Compile::mach_constant_base_node -----------------------
  95 // Constant table base node singleton.
  96 MachConstantBaseNode* Compile::mach_constant_base_node() {
  97   if (_mach_constant_base_node == nullptr) {
  98     _mach_constant_base_node = new MachConstantBaseNode();
  99     _mach_constant_base_node->add_req(C->root());
 100   }
 101   return _mach_constant_base_node;
 102 }
 103 
 104 
 105 /// Support for intrinsics.
 106 
 107 // Return the index at which m must be inserted (or already exists).
 108 // The sort order is by the address of the ciMethod, with is_virtual as minor key.
 109 class IntrinsicDescPair {
 110  private:
 111   ciMethod* _m;
 112   bool _is_virtual;
 113  public:
 114   IntrinsicDescPair(ciMethod* m, bool is_virtual) : _m(m), _is_virtual(is_virtual) {}
 115   static int compare(IntrinsicDescPair* const& key, CallGenerator* const& elt) {
 116     ciMethod* m= elt->method();
 117     ciMethod* key_m = key->_m;
 118     if (key_m < m)      return -1;
 119     else if (key_m > m) return 1;
 120     else {
 121       bool is_virtual = elt->is_virtual();
 122       bool key_virtual = key->_is_virtual;
 123       if (key_virtual < is_virtual)      return -1;
 124       else if (key_virtual > is_virtual) return 1;
 125       else                               return 0;
 126     }
 127   }
 128 };
 129 int Compile::intrinsic_insertion_index(ciMethod* m, bool is_virtual, bool& found) {
 130 #ifdef ASSERT
 131   for (int i = 1; i < _intrinsics.length(); i++) {
 132     CallGenerator* cg1 = _intrinsics.at(i-1);
 133     CallGenerator* cg2 = _intrinsics.at(i);
 134     assert(cg1->method() != cg2->method()
 135            ? cg1->method()     < cg2->method()
 136            : cg1->is_virtual() < cg2->is_virtual(),
 137            "compiler intrinsics list must stay sorted");
 138   }
 139 #endif
 140   IntrinsicDescPair pair(m, is_virtual);
 141   return _intrinsics.find_sorted<IntrinsicDescPair*, IntrinsicDescPair::compare>(&pair, found);
 142 }
 143 
 144 void Compile::register_intrinsic(CallGenerator* cg) {
 145   bool found = false;
 146   int index = intrinsic_insertion_index(cg->method(), cg->is_virtual(), found);
 147   assert(!found, "registering twice");
 148   _intrinsics.insert_before(index, cg);
 149   assert(find_intrinsic(cg->method(), cg->is_virtual()) == cg, "registration worked");
 150 }
 151 
 152 CallGenerator* Compile::find_intrinsic(ciMethod* m, bool is_virtual) {
 153   assert(m->is_loaded(), "don't try this on unloaded methods");
 154   if (_intrinsics.length() > 0) {
 155     bool found = false;
 156     int index = intrinsic_insertion_index(m, is_virtual, found);
 157      if (found) {
 158       return _intrinsics.at(index);
 159     }
 160   }
 161   // Lazily create intrinsics for intrinsic IDs well-known in the runtime.
 162   if (m->intrinsic_id() != vmIntrinsics::_none &&
 163       m->intrinsic_id() <= vmIntrinsics::LAST_COMPILER_INLINE) {
 164     CallGenerator* cg = make_vm_intrinsic(m, is_virtual);
 165     if (cg != nullptr) {
 166       // Save it for next time:
 167       register_intrinsic(cg);
 168       return cg;
 169     } else {
 170       gather_intrinsic_statistics(m->intrinsic_id(), is_virtual, _intrinsic_disabled);
 171     }
 172   }
 173   return nullptr;
 174 }
 175 
 176 // Compile::make_vm_intrinsic is defined in library_call.cpp.
 177 
 178 #ifndef PRODUCT
 179 // statistics gathering...
 180 
 181 juint  Compile::_intrinsic_hist_count[vmIntrinsics::number_of_intrinsics()] = {0};
 182 jubyte Compile::_intrinsic_hist_flags[vmIntrinsics::number_of_intrinsics()] = {0};
 183 
 184 inline int as_int(vmIntrinsics::ID id) {
 185   return vmIntrinsics::as_int(id);
 186 }
 187 
 188 bool Compile::gather_intrinsic_statistics(vmIntrinsics::ID id, bool is_virtual, int flags) {
 189   assert(id > vmIntrinsics::_none && id < vmIntrinsics::ID_LIMIT, "oob");
 190   int oflags = _intrinsic_hist_flags[as_int(id)];
 191   assert(flags != 0, "what happened?");
 192   if (is_virtual) {
 193     flags |= _intrinsic_virtual;
 194   }
 195   bool changed = (flags != oflags);
 196   if ((flags & _intrinsic_worked) != 0) {
 197     juint count = (_intrinsic_hist_count[as_int(id)] += 1);
 198     if (count == 1) {
 199       changed = true;           // first time
 200     }
 201     // increment the overall count also:
 202     _intrinsic_hist_count[as_int(vmIntrinsics::_none)] += 1;
 203   }
 204   if (changed) {
 205     if (((oflags ^ flags) & _intrinsic_virtual) != 0) {
 206       // Something changed about the intrinsic's virtuality.
 207       if ((flags & _intrinsic_virtual) != 0) {
 208         // This is the first use of this intrinsic as a virtual call.
 209         if (oflags != 0) {
 210           // We already saw it as a non-virtual, so note both cases.
 211           flags |= _intrinsic_both;
 212         }
 213       } else if ((oflags & _intrinsic_both) == 0) {
 214         // This is the first use of this intrinsic as a non-virtual
 215         flags |= _intrinsic_both;
 216       }
 217     }
 218     _intrinsic_hist_flags[as_int(id)] = (jubyte) (oflags | flags);
 219   }
 220   // update the overall flags also:
 221   _intrinsic_hist_flags[as_int(vmIntrinsics::_none)] |= (jubyte) flags;
 222   return changed;
 223 }
 224 
 225 static char* format_flags(int flags, char* buf) {
 226   buf[0] = 0;
 227   if ((flags & Compile::_intrinsic_worked) != 0)    strcat(buf, ",worked");
 228   if ((flags & Compile::_intrinsic_failed) != 0)    strcat(buf, ",failed");
 229   if ((flags & Compile::_intrinsic_disabled) != 0)  strcat(buf, ",disabled");
 230   if ((flags & Compile::_intrinsic_virtual) != 0)   strcat(buf, ",virtual");
 231   if ((flags & Compile::_intrinsic_both) != 0)      strcat(buf, ",nonvirtual");
 232   if (buf[0] == 0)  strcat(buf, ",");
 233   assert(buf[0] == ',', "must be");
 234   return &buf[1];
 235 }
 236 
 237 void Compile::print_intrinsic_statistics() {
 238   char flagsbuf[100];
 239   ttyLocker ttyl;
 240   if (xtty != nullptr)  xtty->head("statistics type='intrinsic'");
 241   tty->print_cr("Compiler intrinsic usage:");
 242   juint total = _intrinsic_hist_count[as_int(vmIntrinsics::_none)];
 243   if (total == 0)  total = 1;  // avoid div0 in case of no successes
 244   #define PRINT_STAT_LINE(name, c, f) \
 245     tty->print_cr("  %4d (%4.1f%%) %s (%s)", (int)(c), ((c) * 100.0) / total, name, f);
 246   for (auto id : EnumRange<vmIntrinsicID>{}) {
 247     int   flags = _intrinsic_hist_flags[as_int(id)];
 248     juint count = _intrinsic_hist_count[as_int(id)];
 249     if ((flags | count) != 0) {
 250       PRINT_STAT_LINE(vmIntrinsics::name_at(id), count, format_flags(flags, flagsbuf));
 251     }
 252   }
 253   PRINT_STAT_LINE("total", total, format_flags(_intrinsic_hist_flags[as_int(vmIntrinsics::_none)], flagsbuf));
 254   if (xtty != nullptr)  xtty->tail("statistics");
 255 }
 256 
 257 void Compile::print_statistics() {
 258   { ttyLocker ttyl;
 259     if (xtty != nullptr)  xtty->head("statistics type='opto'");
 260     Parse::print_statistics();
 261     PhaseStringOpts::print_statistics();
 262     PhaseCCP::print_statistics();
 263     PhaseRegAlloc::print_statistics();
 264     PhaseOutput::print_statistics();
 265     PhasePeephole::print_statistics();
 266     PhaseIdealLoop::print_statistics();
 267     ConnectionGraph::print_statistics();
 268     PhaseMacroExpand::print_statistics();
 269     if (xtty != nullptr)  xtty->tail("statistics");
 270   }
 271   if (_intrinsic_hist_flags[as_int(vmIntrinsics::_none)] != 0) {
 272     // put this under its own <statistics> element.
 273     print_intrinsic_statistics();
 274   }
 275 }
 276 #endif //PRODUCT
 277 
 278 void Compile::gvn_replace_by(Node* n, Node* nn) {
 279   for (DUIterator_Last imin, i = n->last_outs(imin); i >= imin; ) {
 280     Node* use = n->last_out(i);
 281     bool is_in_table = initial_gvn()->hash_delete(use);
 282     uint uses_found = 0;
 283     for (uint j = 0; j < use->len(); j++) {
 284       if (use->in(j) == n) {
 285         if (j < use->req())
 286           use->set_req(j, nn);
 287         else
 288           use->set_prec(j, nn);
 289         uses_found++;
 290       }
 291     }
 292     if (is_in_table) {
 293       // reinsert into table
 294       initial_gvn()->hash_find_insert(use);
 295     }
 296     record_for_igvn(use);
 297     PhaseIterGVN::add_users_of_use_to_worklist(nn, use, *_igvn_worklist);
 298     i -= uses_found;    // we deleted 1 or more copies of this edge
 299   }
 300 }
 301 
 302 
 303 // Identify all nodes that are reachable from below, useful.
 304 // Use breadth-first pass that records state in a Unique_Node_List,
 305 // recursive traversal is slower.
 306 void Compile::identify_useful_nodes(Unique_Node_List &useful) {
 307   int estimated_worklist_size = live_nodes();
 308   useful.map( estimated_worklist_size, nullptr );  // preallocate space
 309 
 310   // Initialize worklist
 311   if (root() != nullptr)  { useful.push(root()); }
 312   // If 'top' is cached, declare it useful to preserve cached node
 313   if (cached_top_node())  { useful.push(cached_top_node()); }
 314 
 315   // Push all useful nodes onto the list, breadthfirst
 316   for( uint next = 0; next < useful.size(); ++next ) {
 317     assert( next < unique(), "Unique useful nodes < total nodes");
 318     Node *n  = useful.at(next);
 319     uint max = n->len();
 320     for( uint i = 0; i < max; ++i ) {
 321       Node *m = n->in(i);
 322       if (not_a_node(m))  continue;
 323       useful.push(m);
 324     }
 325   }
 326 }
 327 
 328 // Update dead_node_list with any missing dead nodes using useful
 329 // list. Consider all non-useful nodes to be useless i.e., dead nodes.
 330 void Compile::update_dead_node_list(Unique_Node_List &useful) {
 331   uint max_idx = unique();
 332   VectorSet& useful_node_set = useful.member_set();
 333 
 334   for (uint node_idx = 0; node_idx < max_idx; node_idx++) {
 335     // If node with index node_idx is not in useful set,
 336     // mark it as dead in dead node list.
 337     if (!useful_node_set.test(node_idx)) {
 338       record_dead_node(node_idx);
 339     }
 340   }
 341 }
 342 
 343 void Compile::remove_useless_late_inlines(GrowableArray<CallGenerator*>* inlines, Unique_Node_List &useful) {
 344   int shift = 0;
 345   for (int i = 0; i < inlines->length(); i++) {
 346     CallGenerator* cg = inlines->at(i);
 347     if (useful.member(cg->call_node())) {
 348       if (shift > 0) {
 349         inlines->at_put(i - shift, cg);
 350       }
 351     } else {
 352       shift++; // skip over the dead element
 353     }
 354   }
 355   if (shift > 0) {
 356     inlines->trunc_to(inlines->length() - shift); // remove last elements from compacted array
 357   }
 358 }
 359 
 360 void Compile::remove_useless_late_inlines(GrowableArray<CallGenerator*>* inlines, Node* dead) {
 361   assert(dead != nullptr && dead->is_Call(), "sanity");
 362   int found = 0;
 363   for (int i = 0; i < inlines->length(); i++) {
 364     if (inlines->at(i)->call_node() == dead) {
 365       inlines->remove_at(i);
 366       found++;
 367       NOT_DEBUG( break; ) // elements are unique, so exit early
 368     }
 369   }
 370   assert(found <= 1, "not unique");
 371 }
 372 
 373 template<typename N, ENABLE_IF_SDEFN(std::is_base_of<Node, N>::value)>
 374 void Compile::remove_useless_nodes(GrowableArray<N*>& node_list, Unique_Node_List& useful) {
 375   for (int i = node_list.length() - 1; i >= 0; i--) {
 376     N* node = node_list.at(i);
 377     if (!useful.member(node)) {
 378       node_list.delete_at(i); // replaces i-th with last element which is known to be useful (already processed)
 379     }
 380   }
 381 }
 382 
 383 void Compile::remove_useless_node(Node* dead) {
 384   remove_modified_node(dead);
 385 
 386   // Constant node that has no out-edges and has only one in-edge from
 387   // root is usually dead. However, sometimes reshaping walk makes
 388   // it reachable by adding use edges. So, we will NOT count Con nodes
 389   // as dead to be conservative about the dead node count at any
 390   // given time.
 391   if (!dead->is_Con()) {
 392     record_dead_node(dead->_idx);
 393   }
 394   if (dead->is_macro()) {
 395     remove_macro_node(dead);
 396   }
 397   if (dead->is_expensive()) {
 398     remove_expensive_node(dead);
 399   }
 400   if (dead->is_ReachabilityFence()) {
 401     remove_reachability_fence(dead->as_ReachabilityFence());
 402   }
 403   if (dead->is_OpaqueTemplateAssertionPredicate()) {
 404     remove_template_assertion_predicate_opaque(dead->as_OpaqueTemplateAssertionPredicate());
 405   }
 406   if (dead->is_ParsePredicate()) {
 407     remove_parse_predicate(dead->as_ParsePredicate());
 408   }
 409   if (dead->for_post_loop_opts_igvn()) {
 410     remove_from_post_loop_opts_igvn(dead);
 411   }
 412   if (dead->for_merge_stores_igvn()) {
 413     remove_from_merge_stores_igvn(dead);
 414   }
 415   if (dead->is_Call()) {
 416     remove_useless_late_inlines(                &_late_inlines, dead);
 417     remove_useless_late_inlines(         &_string_late_inlines, dead);
 418     remove_useless_late_inlines(         &_boxing_late_inlines, dead);
 419     remove_useless_late_inlines(&_vector_reboxing_late_inlines, dead);
 420 
 421     if (dead->is_CallStaticJava()) {
 422       remove_unstable_if_trap(dead->as_CallStaticJava(), false);
 423     }
 424   }
 425   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 426   bs->unregister_potential_barrier_node(dead);
 427 }
 428 
 429 // Disconnect all useless nodes by disconnecting those at the boundary.
 430 void Compile::disconnect_useless_nodes(Unique_Node_List& useful, Unique_Node_List& worklist, const Unique_Node_List* root_and_safepoints) {
 431   uint next = 0;
 432   while (next < useful.size()) {
 433     Node *n = useful.at(next++);
 434     if (n->is_SafePoint()) {
 435       // We're done with a parsing phase. Replaced nodes are not valid
 436       // beyond that point.
 437       n->as_SafePoint()->delete_replaced_nodes();
 438     }
 439     // Use raw traversal of out edges since this code removes out edges
 440     int max = n->outcnt();
 441     for (int j = 0; j < max; ++j) {
 442       Node* child = n->raw_out(j);
 443       if (!useful.member(child)) {
 444         assert(!child->is_top() || child != top(),
 445                "If top is cached in Compile object it is in useful list");
 446         // Only need to remove this out-edge to the useless node
 447         n->raw_del_out(j);
 448         --j;
 449         --max;
 450         if (child->is_data_proj_of_pure_function(n)) {
 451           worklist.push(n);
 452         }
 453       }
 454     }
 455     if (n->outcnt() == 1 && n->has_special_unique_user()) {
 456       assert(useful.member(n->unique_out()), "do not push a useless node");
 457       worklist.push(n->unique_out());
 458     }
 459   }
 460 
 461   remove_useless_nodes(_macro_nodes,        useful); // remove useless macro nodes
 462   remove_useless_nodes(_parse_predicates,   useful); // remove useless Parse Predicate nodes
 463   // Remove useless Template Assertion Predicate opaque nodes
 464   remove_useless_nodes(_template_assertion_predicate_opaques, useful);
 465   remove_useless_nodes(_expensive_nodes,    useful); // remove useless expensive nodes
 466   remove_useless_nodes(_reachability_fences, useful); // remove useless node recorded for post loop opts IGVN pass
 467   remove_useless_nodes(_for_post_loop_igvn, useful); // remove useless node recorded for post loop opts IGVN pass
 468   remove_useless_nodes(_for_merge_stores_igvn, useful); // remove useless node recorded for merge stores IGVN pass
 469   remove_useless_unstable_if_traps(useful);          // remove useless unstable_if traps
 470   remove_useless_coarsened_locks(useful);            // remove useless coarsened locks nodes
 471 #ifdef ASSERT
 472   if (_modified_nodes != nullptr) {
 473     _modified_nodes->remove_useless_nodes(useful.member_set());
 474   }
 475 #endif
 476 
 477   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 478   bs->eliminate_useless_gc_barriers(useful, this);
 479   // clean up the late inline lists
 480   remove_useless_late_inlines(                &_late_inlines, useful);
 481   remove_useless_late_inlines(         &_string_late_inlines, useful);
 482   remove_useless_late_inlines(         &_boxing_late_inlines, useful);
 483   remove_useless_late_inlines(&_vector_reboxing_late_inlines, useful);
 484   DEBUG_ONLY(verify_graph_edges(true /*check for no_dead_code*/, root_and_safepoints);)
 485 }
 486 
 487 // ============================================================================
 488 //------------------------------CompileWrapper---------------------------------
 489 class CompileWrapper : public StackObj {
 490   Compile *const _compile;
 491  public:
 492   CompileWrapper(Compile* compile);
 493 
 494   ~CompileWrapper();
 495 };
 496 
 497 CompileWrapper::CompileWrapper(Compile* compile) : _compile(compile) {
 498   // the Compile* pointer is stored in the current ciEnv:
 499   ciEnv* env = compile->env();
 500   assert(env == ciEnv::current(), "must already be a ciEnv active");
 501   assert(env->compiler_data() == nullptr, "compile already active?");
 502   env->set_compiler_data(compile);
 503   assert(compile == Compile::current(), "sanity");
 504 
 505   compile->set_type_dict(nullptr);
 506   compile->set_clone_map(new Dict(cmpkey, hashkey, _compile->comp_arena()));
 507   compile->clone_map().set_clone_idx(0);
 508   compile->set_type_last_size(0);
 509   compile->set_last_tf(nullptr, nullptr);
 510   compile->set_indexSet_arena(nullptr);
 511   compile->set_indexSet_free_block_list(nullptr);
 512   compile->init_type_arena();
 513   Type::Initialize(compile);
 514   _compile->begin_method();
 515   _compile->clone_map().set_debug(_compile->has_method() && _compile->directive()->CloneMapDebugOption);
 516 }
 517 CompileWrapper::~CompileWrapper() {
 518   // simulate crash during compilation
 519   assert(CICrashAt < 0 || _compile->compile_id() != CICrashAt, "just as planned");
 520 
 521   _compile->end_method();
 522   _compile->env()->set_compiler_data(nullptr);
 523 }
 524 
 525 
 526 //----------------------------print_compile_messages---------------------------
 527 void Compile::print_compile_messages() {
 528 #ifndef PRODUCT
 529   // Check if recompiling
 530   if (!subsume_loads() && PrintOpto) {
 531     // Recompiling without allowing machine instructions to subsume loads
 532     tty->print_cr("*********************************************************");
 533     tty->print_cr("** Bailout: Recompile without subsuming loads          **");
 534     tty->print_cr("*********************************************************");
 535   }
 536   if ((do_escape_analysis() != DoEscapeAnalysis) && PrintOpto) {
 537     // Recompiling without escape analysis
 538     tty->print_cr("*********************************************************");
 539     tty->print_cr("** Bailout: Recompile without escape analysis          **");
 540     tty->print_cr("*********************************************************");
 541   }
 542   if (do_iterative_escape_analysis() != DoEscapeAnalysis && PrintOpto) {
 543     // Recompiling without iterative escape analysis
 544     tty->print_cr("*********************************************************");
 545     tty->print_cr("** Bailout: Recompile without iterative escape analysis**");
 546     tty->print_cr("*********************************************************");
 547   }
 548   if (do_reduce_allocation_merges() != ReduceAllocationMerges && PrintOpto) {
 549     // Recompiling without reducing allocation merges
 550     tty->print_cr("*********************************************************");
 551     tty->print_cr("** Bailout: Recompile without reduce allocation merges **");
 552     tty->print_cr("*********************************************************");
 553   }
 554   if ((eliminate_boxing() != EliminateAutoBox) && PrintOpto) {
 555     // Recompiling without boxing elimination
 556     tty->print_cr("*********************************************************");
 557     tty->print_cr("** Bailout: Recompile without boxing elimination       **");
 558     tty->print_cr("*********************************************************");
 559   }
 560   if ((do_locks_coarsening() != EliminateLocks) && PrintOpto) {
 561     // Recompiling without locks coarsening
 562     tty->print_cr("*********************************************************");
 563     tty->print_cr("** Bailout: Recompile without locks coarsening         **");
 564     tty->print_cr("*********************************************************");
 565   }
 566   if (env()->break_at_compile()) {
 567     // Open the debugger when compiling this method.
 568     tty->print("### Breaking when compiling: ");
 569     method()->print_short_name();
 570     tty->cr();
 571     BREAKPOINT;
 572   }
 573 
 574   if( PrintOpto ) {
 575     if (is_osr_compilation()) {
 576       tty->print("[OSR]%3d", _compile_id);
 577     } else {
 578       tty->print("%3d", _compile_id);
 579     }
 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                compile_phase_name);
 619   }
 620 
 621   tty->print("%s", ss.as_string());
 622 
 623   if (xtty != nullptr) {
 624     xtty->tail("ideal");
 625   }
 626 }
 627 #endif
 628 
 629 // ============================================================================
 630 //------------------------------Compile standard-------------------------------
 631 
 632 // Compile a method.  entry_bci is -1 for normal compilations and indicates
 633 // the continuation bci for on stack replacement.
 634 
 635 
 636 Compile::Compile(ciEnv* ci_env, ciMethod* target, int osr_bci,
 637                  Options options, DirectiveSet* directive)
 638     : Phase(Compiler),
 639       _compile_id(ci_env->compile_id()),
 640       _options(options),
 641       _method(target),
 642       _entry_bci(osr_bci),
 643       _ilt(nullptr),
 644       _stub_function(nullptr),
 645       _stub_name(nullptr),
 646       _stub_id(StubId::NO_STUBID),
 647       _stub_entry_point(nullptr),
 648       _max_node_limit(MaxNodeLimit),
 649       _node_count_inlining_cutoff(NodeCountInliningCutoff),
 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       _stress_seed(0),
 663       _comp_arena(mtCompiler, Arena::Tag::tag_comp),
 664       _barrier_set_state(BarrierSet::barrier_set()->barrier_set_c2()->create_barrier_state(comp_arena())),
 665       _env(ci_env),
 666       _directive(directive),
 667       _log(ci_env->log()),
 668       _first_failure_details(nullptr),
 669       _intrinsics(comp_arena(), 0, 0, nullptr),
 670       _macro_nodes(comp_arena(), 8, 0, nullptr),
 671       _parse_predicates(comp_arena(), 8, 0, nullptr),
 672       _template_assertion_predicate_opaques(comp_arena(), 8, 0, nullptr),
 673       _expensive_nodes(comp_arena(), 8, 0, nullptr),
 674       _reachability_fences(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 || StressCountedLoop) {
 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   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 880   bs->final_refinement(this);
 881 
 882 #ifdef ASSERT
 883   bs->verify_gc_barriers(this, BarrierSetC2::BeforeCodeGen);
 884 #endif
 885 
 886   // Dump compilation data to replay it.
 887   if (directive->DumpReplayOption) {
 888     env()->dump_replay_data(_compile_id);
 889   }
 890   if (directive->DumpInlineOption && (ilt() != nullptr)) {
 891     env()->dump_inline_data(_compile_id);
 892   }
 893 
 894   // Now that we know the size of all the monitors we can add a fixed slot
 895   // for the original deopt pc.
 896   int next_slot = fixed_slots() + (sizeof(address) / VMRegImpl::stack_slot_size);
 897   set_fixed_slots(next_slot);
 898 
 899   // Compute when to use implicit null checks. Used by matching trap based
 900   // nodes and NullCheck optimization.
 901   set_allowed_deopt_reasons();
 902 
 903   // Now generate code
 904   Code_Gen();
 905 }
 906 
 907 // C2 uses runtime stubs serialized generation to initialize its static tables
 908 // shared by all compilations, like Type::_shared_type_dict.
 909 // At least one stub have to be completely generated to execute intialization
 910 // before we can skip the rest stubs generation by loading AOT cached stubs.
 911 
 912 static bool c2_do_stub_init_complete = false;
 913 
 914 //------------------------------Compile----------------------------------------
 915 // Compile a runtime stub
 916 Compile::Compile(ciEnv* ci_env,
 917                  TypeFunc_generator generator,
 918                  address stub_function,
 919                  const char* stub_name,
 920                  StubId stub_id,
 921                  int is_fancy_jump,
 922                  bool pass_tls,
 923                  bool return_pc,
 924                  DirectiveSet* directive)
 925     : Phase(Compiler),
 926       _compile_id(0),
 927       _options(Options::for_runtime_stub()),
 928       _method(nullptr),
 929       _entry_bci(InvocationEntryBci),
 930       _stub_function(stub_function),
 931       _stub_name(stub_name),
 932       _stub_id(stub_id),
 933       _stub_entry_point(nullptr),
 934       _max_node_limit(MaxNodeLimit),
 935       _node_count_inlining_cutoff(NodeCountInliningCutoff),
 936       _post_loop_opts_phase(false),
 937       _merge_stores_phase(false),
 938       _allow_macro_nodes(true),
 939       _inlining_progress(false),
 940       _inlining_incrementally(false),
 941       _has_reserved_stack_access(false),
 942 #ifndef PRODUCT
 943       _igv_idx(0),
 944       _trace_opto_output(directive->TraceOptoOutputOption),
 945 #endif
 946       _clinit_barrier_on_entry(false),
 947       _stress_seed(0),
 948       _comp_arena(mtCompiler, Arena::Tag::tag_comp),
 949       _barrier_set_state(BarrierSet::barrier_set()->barrier_set_c2()->create_barrier_state(comp_arena())),
 950       _env(ci_env),
 951       _directive(directive),
 952       _log(ci_env->log()),
 953       _first_failure_details(nullptr),
 954       _reachability_fences(comp_arena(), 8, 0, nullptr),
 955       _for_post_loop_igvn(comp_arena(), 8, 0, nullptr),
 956       _for_merge_stores_igvn(comp_arena(), 8, 0, nullptr),
 957       _congraph(nullptr),
 958       NOT_PRODUCT(_igv_printer(nullptr) COMMA)
 959       _unique(0),
 960       _dead_node_count(0),
 961       _dead_node_list(comp_arena()),
 962       _node_arena_one(mtCompiler, Arena::Tag::tag_node),
 963       _node_arena_two(mtCompiler, Arena::Tag::tag_node),
 964       _node_arena(&_node_arena_one),
 965       _mach_constant_base_node(nullptr),
 966       _Compile_types(mtCompiler, Arena::Tag::tag_type),
 967       _initial_gvn(nullptr),
 968       _igvn_worklist(nullptr),
 969       _types(nullptr),
 970       _node_hash(nullptr),
 971       _has_mh_late_inlines(false),
 972       _oom(false),
 973       _replay_inline_data(nullptr),
 974       _inline_printer(this),
 975       _java_calls(0),
 976       _inner_loops(0),
 977       _FIRST_STACK_mask(comp_arena()),
 978       _interpreter_frame_size(0),
 979       _regmask_arena(mtCompiler, Arena::Tag::tag_regmask),
 980       _output(nullptr),
 981 #ifndef PRODUCT
 982       _in_dump_cnt(0),
 983 #endif
 984       _allowed_reasons(0) {
 985   C = this;
 986 
 987   // try to reuse an existing stub
 988   if (c2_do_stub_init_complete) {
 989     BlobId blob_id = StubInfo::blob(_stub_id);
 990     CodeBlob* blob = AOTCodeCache::load_code_blob(AOTCodeEntry::C2Blob, blob_id);
 991     if (blob != nullptr) {
 992       RuntimeStub* rs = blob->as_runtime_stub();
 993       _stub_entry_point = rs->entry_point();
 994       return;
 995     }
 996   }
 997 
 998   TraceTime t1(nullptr, &_t_totalCompilation, CITime, false);
 999   TraceTime t2(nullptr, &_t_stubCompilation, CITime, false);
1000 
1001 #ifndef PRODUCT
1002   set_print_assembly(PrintFrameConverterAssembly);
1003   set_parsed_irreducible_loop(false);
1004 #else
1005   set_print_assembly(false); // Must initialize.
1006 #endif
1007   set_has_irreducible_loop(false); // no loops
1008 
1009   CompileWrapper cw(this);
1010   Init(/*do_aliasing=*/ false);
1011   init_tf((*generator)());
1012 
1013   _igvn_worklist = new (comp_arena()) Unique_Node_List(comp_arena());
1014   _types = new (comp_arena()) Type_Array(comp_arena());
1015   _node_hash = new (comp_arena()) NodeHash(comp_arena(), 255);
1016 
1017   if (StressLCM || StressGCM || StressBailout) {
1018     initialize_stress_seed(directive);
1019   }
1020 
1021   {
1022     PhaseGVN gvn;
1023     set_initial_gvn(&gvn);    // not significant, but GraphKit guys use it pervasively
1024     gvn.transform(top());
1025 
1026     GraphKit kit;
1027     kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
1028   }
1029 
1030   NOT_PRODUCT( verify_graph_edges(); )
1031 
1032   Code_Gen();
1033 
1034   // First successful stub generation will set it to `true`
1035   // and it will stay `true` after that.
1036   c2_do_stub_init_complete = c2_do_stub_init_complete || (_stub_entry_point != nullptr);
1037 }
1038 
1039 Compile::~Compile() {
1040   delete _first_failure_details;
1041 };
1042 
1043 //------------------------------Init-------------------------------------------
1044 // Prepare for a single compilation
1045 void Compile::Init(bool aliasing) {
1046   _do_aliasing = aliasing;
1047   _unique  = 0;
1048   _regalloc = nullptr;
1049 
1050   _tf      = nullptr;  // filled in later
1051   _top     = nullptr;  // cached later
1052   _matcher = nullptr;  // filled in later
1053   _cfg     = nullptr;  // filled in later
1054 
1055   _node_note_array = nullptr;
1056   _default_node_notes = nullptr;
1057   DEBUG_ONLY( _modified_nodes = nullptr; ) // Used in Optimize()
1058 
1059   _immutable_memory = nullptr; // filled in at first inquiry
1060 
1061 #ifdef ASSERT
1062   _phase_optimize_finished = false;
1063   _phase_verify_ideal_loop = false;
1064   _exception_backedge = false;
1065   _type_verify = nullptr;
1066 #endif
1067 
1068   // Globally visible Nodes
1069   // First set TOP to null to give safe behavior during creation of RootNode
1070   set_cached_top_node(nullptr);
1071   set_root(new RootNode());
1072   // Now that you have a Root to point to, create the real TOP
1073   set_cached_top_node( new ConNode(Type::TOP) );
1074   set_recent_alloc(nullptr, nullptr);
1075 
1076   // Create Debug Information Recorder to record scopes, oopmaps, etc.
1077   env()->set_oop_recorder(new OopRecorder(env()->arena()));
1078   env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
1079   env()->set_dependencies(new Dependencies(env()));
1080 
1081   _fixed_slots = 0;
1082   set_has_split_ifs(false);
1083   set_has_loops(false); // first approximation
1084   set_has_stringbuilder(false);
1085   set_has_boxed_value(false);
1086   _trap_can_recompile = false;  // no traps emitted yet
1087   _major_progress = true; // start out assuming good things will happen
1088   set_has_unsafe_access(false);
1089   set_max_vector_size(0);
1090   set_clear_upper_avx(false);  //false as default for clear upper bits of ymm registers
1091   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
1092   set_decompile_count(0);
1093 
1094 #ifndef PRODUCT
1095   _phase_counter = 0;
1096   Copy::zero_to_bytes(_igv_phase_iter, sizeof(_igv_phase_iter));
1097 #endif
1098 
1099   set_do_freq_based_layout(_directive->BlockLayoutByFrequencyOption);
1100   _loop_opts_cnt = LoopOptsCount;
1101   set_do_inlining(Inline);
1102   set_max_inline_size(MaxInlineSize);
1103   set_freq_inline_size(FreqInlineSize);
1104   set_do_scheduling(OptoScheduling);
1105 
1106   set_do_vector_loop(false);
1107   set_has_monitors(false);
1108   set_has_scoped_access(false);
1109 
1110   if (AllowVectorizeOnDemand) {
1111     if (has_method() && _directive->VectorizeOption) {
1112       set_do_vector_loop(true);
1113       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());})
1114     } else if (has_method() && method()->name() != nullptr &&
1115                method()->intrinsic_id() == vmIntrinsics::_forEachRemaining) {
1116       set_do_vector_loop(true);
1117     }
1118   }
1119   set_use_cmove(UseCMoveUnconditionally /* || do_vector_loop()*/); //TODO: consider do_vector_loop() mandate use_cmove unconditionally
1120   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());})
1121 
1122   _max_node_limit = _directive->MaxNodeLimitOption;
1123 
1124   if (VM_Version::supports_fast_class_init_checks() && has_method() && !is_osr_compilation() && method()->needs_clinit_barrier()) {
1125     set_clinit_barrier_on_entry(true);
1126   }
1127   if (debug_info()->recording_non_safepoints()) {
1128     set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
1129                         (comp_arena(), 8, 0, nullptr));
1130     set_default_node_notes(Node_Notes::make(this));
1131   }
1132 
1133   const int grow_ats = 16;
1134   _max_alias_types = grow_ats;
1135   _alias_types   = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
1136   AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType,  grow_ats);
1137   Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
1138   {
1139     for (int i = 0; i < grow_ats; i++)  _alias_types[i] = &ats[i];
1140   }
1141   // Initialize the first few types.
1142   _alias_types[AliasIdxTop]->Init(AliasIdxTop, nullptr);
1143   _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
1144   _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
1145   _num_alias_types = AliasIdxRaw+1;
1146   // Zero out the alias type cache.
1147   Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
1148   // A null adr_type hits in the cache right away.  Preload the right answer.
1149   probe_alias_cache(nullptr)->_index = AliasIdxTop;
1150 }
1151 
1152 #ifdef ASSERT
1153 // Verify that the current StartNode is valid.
1154 void Compile::verify_start(StartNode* s) const {
1155   assert(failing_internal() || s == start(), "should be StartNode");
1156 }
1157 #endif
1158 
1159 /**
1160  * Return the 'StartNode'. We must not have a pending failure, since the ideal graph
1161  * can be in an inconsistent state, i.e., we can get segmentation faults when traversing
1162  * the ideal graph.
1163  */
1164 StartNode* Compile::start() const {
1165   assert (!failing_internal() || C->failure_is_artificial(), "Must not have pending failure. Reason is: %s", failure_reason());
1166   for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
1167     Node* start = root()->fast_out(i);
1168     if (start->is_Start()) {
1169       return start->as_Start();
1170     }
1171   }
1172   fatal("Did not find Start node!");
1173   return nullptr;
1174 }
1175 
1176 //-------------------------------immutable_memory-------------------------------------
1177 // Access immutable memory
1178 Node* Compile::immutable_memory() {
1179   if (_immutable_memory != nullptr) {
1180     return _immutable_memory;
1181   }
1182   StartNode* s = start();
1183   for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
1184     Node *p = s->fast_out(i);
1185     if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
1186       _immutable_memory = p;
1187       return _immutable_memory;
1188     }
1189   }
1190   ShouldNotReachHere();
1191   return nullptr;
1192 }
1193 
1194 //----------------------set_cached_top_node------------------------------------
1195 // Install the cached top node, and make sure Node::is_top works correctly.
1196 void Compile::set_cached_top_node(Node* tn) {
1197   if (tn != nullptr)  verify_top(tn);
1198   Node* old_top = _top;
1199   _top = tn;
1200   // Calling Node::setup_is_top allows the nodes the chance to adjust
1201   // their _out arrays.
1202   if (_top != nullptr)     _top->setup_is_top();
1203   if (old_top != nullptr)  old_top->setup_is_top();
1204   assert(_top == nullptr || top()->is_top(), "");
1205 }
1206 
1207 #ifdef ASSERT
1208 uint Compile::count_live_nodes_by_graph_walk() {
1209   Unique_Node_List useful(comp_arena());
1210   // Get useful node list by walking the graph.
1211   identify_useful_nodes(useful);
1212   return useful.size();
1213 }
1214 
1215 void Compile::print_missing_nodes() {
1216 
1217   // Return if CompileLog is null and PrintIdealNodeCount is false.
1218   if ((_log == nullptr) && (! PrintIdealNodeCount)) {
1219     return;
1220   }
1221 
1222   // This is an expensive function. It is executed only when the user
1223   // specifies VerifyIdealNodeCount option or otherwise knows the
1224   // additional work that needs to be done to identify reachable nodes
1225   // by walking the flow graph and find the missing ones using
1226   // _dead_node_list.
1227 
1228   Unique_Node_List useful(comp_arena());
1229   // Get useful node list by walking the graph.
1230   identify_useful_nodes(useful);
1231 
1232   uint l_nodes = C->live_nodes();
1233   uint l_nodes_by_walk = useful.size();
1234 
1235   if (l_nodes != l_nodes_by_walk) {
1236     if (_log != nullptr) {
1237       _log->begin_head("mismatched_nodes count='%d'", abs((int) (l_nodes - l_nodes_by_walk)));
1238       _log->stamp();
1239       _log->end_head();
1240     }
1241     VectorSet& useful_member_set = useful.member_set();
1242     int last_idx = l_nodes_by_walk;
1243     for (int i = 0; i < last_idx; i++) {
1244       if (useful_member_set.test(i)) {
1245         if (_dead_node_list.test(i)) {
1246           if (_log != nullptr) {
1247             _log->elem("mismatched_node_info node_idx='%d' type='both live and dead'", i);
1248           }
1249           if (PrintIdealNodeCount) {
1250             // Print the log message to tty
1251               tty->print_cr("mismatched_node idx='%d' both live and dead'", i);
1252               useful.at(i)->dump();
1253           }
1254         }
1255       }
1256       else if (! _dead_node_list.test(i)) {
1257         if (_log != nullptr) {
1258           _log->elem("mismatched_node_info node_idx='%d' type='neither live nor dead'", i);
1259         }
1260         if (PrintIdealNodeCount) {
1261           // Print the log message to tty
1262           tty->print_cr("mismatched_node idx='%d' type='neither live nor dead'", i);
1263         }
1264       }
1265     }
1266     if (_log != nullptr) {
1267       _log->tail("mismatched_nodes");
1268     }
1269   }
1270 }
1271 void Compile::record_modified_node(Node* n) {
1272   if (_modified_nodes != nullptr && !_inlining_incrementally && !n->is_Con()) {
1273     _modified_nodes->push(n);
1274   }
1275 }
1276 
1277 void Compile::remove_modified_node(Node* n) {
1278   if (_modified_nodes != nullptr) {
1279     _modified_nodes->remove(n);
1280   }
1281 }
1282 #endif
1283 
1284 #ifndef PRODUCT
1285 void Compile::verify_top(Node* tn) const {
1286   if (tn != nullptr) {
1287     assert(tn->is_Con(), "top node must be a constant");
1288     assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
1289     assert(tn->in(0) != nullptr, "must have live top node");
1290   }
1291 }
1292 #endif
1293 
1294 
1295 ///-------------------Managing Per-Node Debug & Profile Info-------------------
1296 
1297 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
1298   guarantee(arr != nullptr, "");
1299   int num_blocks = arr->length();
1300   if (grow_by < num_blocks)  grow_by = num_blocks;
1301   int num_notes = grow_by * _node_notes_block_size;
1302   Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
1303   Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
1304   while (num_notes > 0) {
1305     arr->append(notes);
1306     notes     += _node_notes_block_size;
1307     num_notes -= _node_notes_block_size;
1308   }
1309   assert(num_notes == 0, "exact multiple, please");
1310 }
1311 
1312 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
1313   if (source == nullptr || dest == nullptr)  return false;
1314 
1315   if (dest->is_Con())
1316     return false;               // Do not push debug info onto constants.
1317 
1318 #ifdef ASSERT
1319   // Leave a bread crumb trail pointing to the original node:
1320   if (dest != nullptr && dest != source && dest->debug_orig() == nullptr) {
1321     dest->set_debug_orig(source);
1322   }
1323 #endif
1324 
1325   if (node_note_array() == nullptr)
1326     return false;               // Not collecting any notes now.
1327 
1328   // This is a copy onto a pre-existing node, which may already have notes.
1329   // If both nodes have notes, do not overwrite any pre-existing notes.
1330   Node_Notes* source_notes = node_notes_at(source->_idx);
1331   if (source_notes == nullptr || source_notes->is_clear())  return false;
1332   Node_Notes* dest_notes   = node_notes_at(dest->_idx);
1333   if (dest_notes == nullptr || dest_notes->is_clear()) {
1334     return set_node_notes_at(dest->_idx, source_notes);
1335   }
1336 
1337   Node_Notes merged_notes = (*source_notes);
1338   // The order of operations here ensures that dest notes will win...
1339   merged_notes.update_from(dest_notes);
1340   return set_node_notes_at(dest->_idx, &merged_notes);
1341 }
1342 
1343 
1344 //--------------------------allow_range_check_smearing-------------------------
1345 // Gating condition for coalescing similar range checks.
1346 // Sometimes we try 'speculatively' replacing a series of a range checks by a
1347 // single covering check that is at least as strong as any of them.
1348 // If the optimization succeeds, the simplified (strengthened) range check
1349 // will always succeed.  If it fails, we will deopt, and then give up
1350 // on the optimization.
1351 bool Compile::allow_range_check_smearing() const {
1352   // If this method has already thrown a range-check,
1353   // assume it was because we already tried range smearing
1354   // and it failed.
1355   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
1356   return !already_trapped;
1357 }
1358 
1359 
1360 //------------------------------flatten_alias_type-----------------------------
1361 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
1362   assert(do_aliasing(), "Aliasing should be enabled");
1363   int offset = tj->offset();
1364   TypePtr::PTR ptr = tj->ptr();
1365 
1366   // Known instance (scalarizable allocation) alias only with itself.
1367   bool is_known_inst = tj->isa_oopptr() != nullptr &&
1368                        tj->is_oopptr()->is_known_instance();
1369 
1370   // Process weird unsafe references.
1371   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
1372     assert(InlineUnsafeOps || StressReflectiveCode, "indeterminate pointers come only from unsafe ops");
1373     assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
1374     tj = TypeOopPtr::BOTTOM;
1375     ptr = tj->ptr();
1376     offset = tj->offset();
1377   }
1378 
1379   // Array pointers need some flattening
1380   const TypeAryPtr* ta = tj->isa_aryptr();
1381   if (ta && ta->is_stable()) {
1382     // Erase stability property for alias analysis.
1383     tj = ta = ta->cast_to_stable(false);
1384   }
1385   if( ta && is_known_inst ) {
1386     if ( offset != Type::OffsetBot &&
1387          offset > arrayOopDesc::length_offset_in_bytes() ) {
1388       offset = Type::OffsetBot; // Flatten constant access into array body only
1389       tj = ta = ta->
1390               remove_speculative()->
1391               cast_to_ptr_type(ptr)->
1392               with_offset(offset);
1393     }
1394   } else if (ta != nullptr) {
1395     // Common slices
1396     if (offset == arrayOopDesc::length_offset_in_bytes()) {
1397       return TypeAryPtr::RANGE;
1398     } else if (offset == oopDesc::klass_offset_in_bytes()) {
1399       return TypeInstPtr::KLASS;
1400     } else if (offset == oopDesc::mark_offset_in_bytes()) {
1401       return TypeInstPtr::MARK;
1402     }
1403 
1404     // Remove size and stability
1405     const TypeAry* normalized_ary = TypeAry::make(ta->elem(), TypeInt::POS, false);
1406     // Remove ptr, const_oop, and offset
1407     if (ta->elem() == Type::BOTTOM) {
1408       // Bottom array (meet of int[] and byte[] for example), accesses to it will be done with
1409       // Unsafe. This should alias with all arrays. For now just leave it as it is (this is
1410       // incorrect, see JDK-8331133).
1411       tj = ta = TypeAryPtr::make(TypePtr::BotPTR, nullptr, normalized_ary, nullptr, false, Type::OffsetBot);
1412     } else if (ta->elem()->make_oopptr() != nullptr) {
1413       // Object arrays, all of them share the same slice
1414       const TypeAry* tary = TypeAry::make(TypeInstPtr::BOTTOM, TypeInt::POS, false);
1415       tj = ta = TypeAryPtr::make(TypePtr::BotPTR, nullptr, tary, nullptr, false, Type::OffsetBot);
1416     } else {
1417       // Primitive arrays
1418       tj = ta = TypeAryPtr::make(TypePtr::BotPTR, nullptr, normalized_ary, ta->exact_klass(), true, Type::OffsetBot);
1419     }
1420 
1421     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
1422     // cannot be distinguished by bytecode alone.
1423     if (ta->elem() == TypeInt::BOOL) {
1424       tj = ta = TypeAryPtr::BYTES;
1425     }
1426   }
1427 
1428   // Oop pointers need some flattening
1429   const TypeInstPtr *to = tj->isa_instptr();
1430   if (to && to != TypeOopPtr::BOTTOM) {
1431     ciInstanceKlass* ik = to->instance_klass();
1432     if( ptr == TypePtr::Constant ) {
1433       if (ik != ciEnv::current()->Class_klass() ||
1434           offset < ik->layout_helper_size_in_bytes()) {
1435         // No constant oop pointers (such as Strings); they alias with
1436         // unknown strings.
1437         assert(!is_known_inst, "not scalarizable allocation");
1438         tj = to = to->
1439                 cast_to_instance_id(TypeOopPtr::InstanceBot)->
1440                 remove_speculative()->
1441                 cast_to_ptr_type(TypePtr::BotPTR)->
1442                 cast_to_exactness(false);
1443       }
1444     } else if( is_known_inst ) {
1445       tj = to; // Keep NotNull and klass_is_exact for instance type
1446     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
1447       // During the 2nd round of IterGVN, NotNull castings are removed.
1448       // Make sure the Bottom and NotNull variants alias the same.
1449       // Also, make sure exact and non-exact variants alias the same.
1450       tj = to = to->
1451               remove_speculative()->
1452               cast_to_instance_id(TypeOopPtr::InstanceBot)->
1453               cast_to_ptr_type(TypePtr::BotPTR)->
1454               cast_to_exactness(false);
1455     }
1456     if (to->speculative() != nullptr) {
1457       tj = to = to->remove_speculative();
1458     }
1459     // Canonicalize the holder of this field
1460     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
1461       // First handle header references such as a LoadKlassNode, even if the
1462       // object's klass is unloaded at compile time (4965979).
1463       if (!is_known_inst) { // Do it only for non-instance types
1464         tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, nullptr, offset);
1465       }
1466     } else if (offset < 0 || offset >= ik->layout_helper_size_in_bytes()) {
1467       // Static fields are in the space above the normal instance
1468       // fields in the java.lang.Class instance.
1469       if (ik != ciEnv::current()->Class_klass()) {
1470         to = nullptr;
1471         tj = TypeOopPtr::BOTTOM;
1472         offset = tj->offset();
1473       }
1474     } else {
1475       ciInstanceKlass *canonical_holder = ik->get_canonical_holder(offset);
1476       assert(offset < canonical_holder->layout_helper_size_in_bytes(), "");
1477       assert(tj->offset() == offset, "no change to offset expected");
1478       bool xk = to->klass_is_exact();
1479       int instance_id = to->instance_id();
1480 
1481       // If the input type's class is the holder: if exact, the type only includes interfaces implemented by the holder
1482       // but if not exact, it may include extra interfaces: build new type from the holder class to make sure only
1483       // its interfaces are included.
1484       if (xk && ik->equals(canonical_holder)) {
1485         assert(tj == TypeInstPtr::make(to->ptr(), canonical_holder, is_known_inst, nullptr, offset, instance_id), "exact type should be canonical type");
1486       } else {
1487         assert(xk || !is_known_inst, "Known instance should be exact type");
1488         tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, is_known_inst, nullptr, offset, instance_id);
1489       }
1490     }
1491   }
1492 
1493   // Klass pointers to object array klasses need some flattening
1494   const TypeKlassPtr *tk = tj->isa_klassptr();
1495   if( tk ) {
1496     // If we are referencing a field within a Klass, we need
1497     // to assume the worst case of an Object.  Both exact and
1498     // inexact types must flatten to the same alias class so
1499     // use NotNull as the PTR.
1500     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
1501       tj = tk = TypeInstKlassPtr::make(TypePtr::NotNull,
1502                                        env()->Object_klass(),
1503                                        offset);
1504     }
1505 
1506     if (tk->isa_aryklassptr() && tk->is_aryklassptr()->elem()->isa_klassptr()) {
1507       ciKlass* k = ciObjArrayKlass::make(env()->Object_klass());
1508       if (!k || !k->is_loaded()) {                  // Only fails for some -Xcomp runs
1509         tj = tk = TypeInstKlassPtr::make(TypePtr::NotNull, env()->Object_klass(), offset);
1510       } else {
1511         tj = tk = TypeAryKlassPtr::make(TypePtr::NotNull, tk->is_aryklassptr()->elem(), k, offset);
1512       }
1513     }
1514 
1515     // Check for precise loads from the primary supertype array and force them
1516     // to the supertype cache alias index.  Check for generic array loads from
1517     // the primary supertype array and also force them to the supertype cache
1518     // alias index.  Since the same load can reach both, we need to merge
1519     // these 2 disparate memories into the same alias class.  Since the
1520     // primary supertype array is read-only, there's no chance of confusion
1521     // where we bypass an array load and an array store.
1522     int primary_supers_offset = in_bytes(Klass::primary_supers_offset());
1523     if (offset == Type::OffsetBot ||
1524         (offset >= primary_supers_offset &&
1525          offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
1526         offset == (int)in_bytes(Klass::secondary_super_cache_offset())) {
1527       offset = in_bytes(Klass::secondary_super_cache_offset());
1528       tj = tk = tk->with_offset(offset);
1529     }
1530   }
1531 
1532   // Flatten all Raw pointers together.
1533   if (tj->base() == Type::RawPtr)
1534     tj = TypeRawPtr::BOTTOM;
1535 
1536   if (tj->base() == Type::AnyPtr)
1537     tj = TypePtr::BOTTOM;      // An error, which the caller must check for.
1538 
1539   offset = tj->offset();
1540   assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
1541 
1542   assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
1543           (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
1544           (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
1545           (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
1546           (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1547           (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1548           (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr),
1549           "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
1550   assert( tj->ptr() != TypePtr::TopPTR &&
1551           tj->ptr() != TypePtr::AnyNull &&
1552           tj->ptr() != TypePtr::Null, "No imprecise addresses" );
1553 //    assert( tj->ptr() != TypePtr::Constant ||
1554 //            tj->base() == Type::RawPtr ||
1555 //            tj->base() == Type::KlassPtr, "No constant oop addresses" );
1556 
1557   return tj;
1558 }
1559 
1560 void Compile::AliasType::Init(int i, const TypePtr* at) {
1561   assert(AliasIdxTop <= i && i < Compile::current()->_max_alias_types, "Invalid alias index");
1562   _index = i;
1563   _adr_type = at;
1564   _field = nullptr;
1565   _element = nullptr;
1566   _is_rewritable = true; // default
1567   const TypeOopPtr *atoop = (at != nullptr) ? at->isa_oopptr() : nullptr;
1568   if (atoop != nullptr && atoop->is_known_instance()) {
1569     const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
1570     _general_index = Compile::current()->get_alias_index(gt);
1571   } else {
1572     _general_index = 0;
1573   }
1574 }
1575 
1576 BasicType Compile::AliasType::basic_type() const {
1577   if (element() != nullptr) {
1578     const Type* element = adr_type()->is_aryptr()->elem();
1579     return element->isa_narrowoop() ? T_OBJECT : element->array_element_basic_type();
1580   } if (field() != nullptr) {
1581     return field()->layout_type();
1582   } else {
1583     return T_ILLEGAL; // unknown
1584   }
1585 }
1586 
1587 //---------------------------------print_on------------------------------------
1588 #ifndef PRODUCT
1589 void Compile::AliasType::print_on(outputStream* st) {
1590   if (index() < 10)
1591         st->print("@ <%d> ", index());
1592   else  st->print("@ <%d>",  index());
1593   st->print(is_rewritable() ? "   " : " RO");
1594   int offset = adr_type()->offset();
1595   if (offset == Type::OffsetBot)
1596         st->print(" +any");
1597   else  st->print(" +%-3d", offset);
1598   st->print(" in ");
1599   adr_type()->dump_on(st);
1600   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
1601   if (field() != nullptr && tjp) {
1602     if (tjp->is_instptr()->instance_klass()  != field()->holder() ||
1603         tjp->offset() != field()->offset_in_bytes()) {
1604       st->print(" != ");
1605       field()->print();
1606       st->print(" ***");
1607     }
1608   }
1609 }
1610 
1611 void print_alias_types() {
1612   Compile* C = Compile::current();
1613   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
1614   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
1615     C->alias_type(idx)->print_on(tty);
1616     tty->cr();
1617   }
1618 }
1619 #endif
1620 
1621 
1622 //----------------------------probe_alias_cache--------------------------------
1623 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
1624   intptr_t key = (intptr_t) adr_type;
1625   key ^= key >> logAliasCacheSize;
1626   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
1627 }
1628 
1629 
1630 //-----------------------------grow_alias_types--------------------------------
1631 void Compile::grow_alias_types() {
1632   const int old_ats  = _max_alias_types; // how many before?
1633   const int new_ats  = old_ats;          // how many more?
1634   const int grow_ats = old_ats+new_ats;  // how many now?
1635   _max_alias_types = grow_ats;
1636   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), _alias_types, old_ats, grow_ats);
1637   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
1638   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
1639   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
1640 }
1641 
1642 
1643 //--------------------------------find_alias_type------------------------------
1644 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field) {
1645   if (!do_aliasing()) {
1646     return alias_type(AliasIdxBot);
1647   }
1648 
1649   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1650   if (ace->_adr_type == adr_type) {
1651     return alias_type(ace->_index);
1652   }
1653 
1654   // Handle special cases.
1655   if (adr_type == nullptr)          return alias_type(AliasIdxTop);
1656   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
1657 
1658   // Do it the slow way.
1659   const TypePtr* flat = flatten_alias_type(adr_type);
1660 
1661 #ifdef ASSERT
1662   {
1663     ResourceMark rm;
1664     assert(flat == flatten_alias_type(flat), "not idempotent: adr_type = %s; flat = %s => %s",
1665            Type::str(adr_type), Type::str(flat), Type::str(flatten_alias_type(flat)));
1666     assert(flat != TypePtr::BOTTOM, "cannot alias-analyze an untyped ptr: adr_type = %s",
1667            Type::str(adr_type));
1668     if (flat->isa_oopptr() && !flat->isa_klassptr()) {
1669       const TypeOopPtr* foop = flat->is_oopptr();
1670       // Scalarizable allocations have exact klass always.
1671       bool exact = !foop->klass_is_exact() || foop->is_known_instance();
1672       const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
1673       assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type: foop = %s; xoop = %s",
1674              Type::str(foop), Type::str(xoop));
1675     }
1676   }
1677 #endif
1678 
1679   int idx = AliasIdxTop;
1680   for (int i = 0; i < num_alias_types(); i++) {
1681     if (alias_type(i)->adr_type() == flat) {
1682       idx = i;
1683       break;
1684     }
1685   }
1686 
1687   if (idx == AliasIdxTop) {
1688     if (no_create)  return nullptr;
1689     // Grow the array if necessary.
1690     if (_num_alias_types == _max_alias_types)  grow_alias_types();
1691     // Add a new alias type.
1692     idx = _num_alias_types++;
1693     _alias_types[idx]->Init(idx, flat);
1694     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
1695     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
1696     if (flat->isa_instptr()) {
1697       if (flat->offset() == java_lang_Class::klass_offset()
1698           && flat->is_instptr()->instance_klass() == env()->Class_klass())
1699         alias_type(idx)->set_rewritable(false);
1700     }
1701     if (flat->isa_aryptr()) {
1702 #ifdef ASSERT
1703       const int header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1704       // (T_BYTE has the weakest alignment and size restrictions...)
1705       assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
1706 #endif
1707       if (flat->offset() == TypePtr::OffsetBot) {
1708         alias_type(idx)->set_element(flat->is_aryptr()->elem());
1709       }
1710     }
1711     if (flat->isa_klassptr()) {
1712       if (UseCompactObjectHeaders) {
1713         if (flat->offset() == in_bytes(Klass::prototype_header_offset()))
1714           alias_type(idx)->set_rewritable(false);
1715       }
1716       if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
1717         alias_type(idx)->set_rewritable(false);
1718       if (flat->offset() == in_bytes(Klass::misc_flags_offset()))
1719         alias_type(idx)->set_rewritable(false);
1720       if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
1721         alias_type(idx)->set_rewritable(false);
1722       if (flat->offset() == in_bytes(Klass::secondary_super_cache_offset()))
1723         alias_type(idx)->set_rewritable(false);
1724     }
1725 
1726     if (flat->isa_instklassptr()) {
1727       if (flat->offset() == in_bytes(InstanceKlass::access_flags_offset())) {
1728         alias_type(idx)->set_rewritable(false);
1729       }
1730     }
1731     // %%% (We would like to finalize JavaThread::threadObj_offset(),
1732     // but the base pointer type is not distinctive enough to identify
1733     // references into JavaThread.)
1734 
1735     // Check for final fields.
1736     const TypeInstPtr* tinst = flat->isa_instptr();
1737     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
1738       ciField* field;
1739       if (tinst->const_oop() != nullptr &&
1740           tinst->instance_klass() == ciEnv::current()->Class_klass() &&
1741           tinst->offset() >= (tinst->instance_klass()->layout_helper_size_in_bytes())) {
1742         // static field
1743         ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
1744         field = k->get_field_by_offset(tinst->offset(), true);
1745       } else {
1746         ciInstanceKlass *k = tinst->instance_klass();
1747         field = k->get_field_by_offset(tinst->offset(), false);
1748       }
1749       assert(field == nullptr ||
1750              original_field == nullptr ||
1751              (field->holder() == original_field->holder() &&
1752               field->offset_in_bytes() == original_field->offset_in_bytes() &&
1753               field->is_static() == original_field->is_static()), "wrong field?");
1754       // Set field() and is_rewritable() attributes.
1755       if (field != nullptr)  alias_type(idx)->set_field(field);
1756     }
1757   }
1758 
1759   // Fill the cache for next time.
1760   ace->_adr_type = adr_type;
1761   ace->_index    = idx;
1762   assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
1763 
1764   // Might as well try to fill the cache for the flattened version, too.
1765   AliasCacheEntry* face = probe_alias_cache(flat);
1766   if (face->_adr_type == nullptr) {
1767     face->_adr_type = flat;
1768     face->_index    = idx;
1769     assert(alias_type(flat) == alias_type(idx), "flat type must work too");
1770   }
1771 
1772   return alias_type(idx);
1773 }
1774 
1775 
1776 Compile::AliasType* Compile::alias_type(ciField* field) {
1777   const TypeOopPtr* t;
1778   if (field->is_static())
1779     t = TypeInstPtr::make(field->holder()->java_mirror());
1780   else
1781     t = TypeOopPtr::make_from_klass_raw(field->holder());
1782   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);
1783   assert((field->is_final() || field->is_stable()) == !atp->is_rewritable(), "must get the rewritable bits correct");
1784   return atp;
1785 }
1786 
1787 
1788 //------------------------------have_alias_type--------------------------------
1789 bool Compile::have_alias_type(const TypePtr* adr_type) {
1790   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1791   if (ace->_adr_type == adr_type) {
1792     return true;
1793   }
1794 
1795   // Handle special cases.
1796   if (adr_type == nullptr)             return true;
1797   if (adr_type == TypePtr::BOTTOM)  return true;
1798 
1799   return find_alias_type(adr_type, true, nullptr) != nullptr;
1800 }
1801 
1802 //-----------------------------must_alias--------------------------------------
1803 // True if all values of the given address type are in the given alias category.
1804 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
1805   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1806   if (adr_type == nullptr)              return true;  // null serves as TypePtr::TOP
1807   if (alias_idx == AliasIdxTop)         return false; // the empty category
1808   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
1809 
1810   // the only remaining possible overlap is identity
1811   int adr_idx = get_alias_index(adr_type);
1812   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1813   assert(adr_idx == alias_idx ||
1814          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
1815           && adr_type                       != TypeOopPtr::BOTTOM),
1816          "should not be testing for overlap with an unsafe pointer");
1817   return adr_idx == alias_idx;
1818 }
1819 
1820 //------------------------------can_alias--------------------------------------
1821 // True if any values of the given address type are in the given alias category.
1822 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
1823   if (alias_idx == AliasIdxTop)         return false; // the empty category
1824   if (adr_type == nullptr)              return false; // null serves as TypePtr::TOP
1825   // Known instance doesn't alias with bottom memory
1826   if (alias_idx == AliasIdxBot)         return !adr_type->is_known_instance();                   // the universal category
1827   if (adr_type->base() == Type::AnyPtr) return !C->get_adr_type(alias_idx)->is_known_instance(); // TypePtr::BOTTOM or its twins
1828 
1829   // the only remaining possible overlap is identity
1830   int adr_idx = get_alias_index(adr_type);
1831   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1832   return adr_idx == alias_idx;
1833 }
1834 
1835 // Mark all ParsePredicateNodes as useless. They will later be removed from the graph in IGVN together with their
1836 // uncommon traps if no Runtime Predicates were created from the Parse Predicates.
1837 void Compile::mark_parse_predicate_nodes_useless(PhaseIterGVN& igvn) {
1838   if (parse_predicate_count() == 0) {
1839     return;
1840   }
1841   for (int i = 0; i < parse_predicate_count(); i++) {
1842     ParsePredicateNode* parse_predicate = _parse_predicates.at(i);
1843     parse_predicate->mark_useless(igvn);
1844   }
1845   _parse_predicates.clear();
1846 }
1847 
1848 void Compile::record_for_post_loop_opts_igvn(Node* n) {
1849   if (!n->for_post_loop_opts_igvn()) {
1850     assert(!_for_post_loop_igvn.contains(n), "duplicate");
1851     n->add_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
1852     _for_post_loop_igvn.append(n);
1853   }
1854 }
1855 
1856 void Compile::remove_from_post_loop_opts_igvn(Node* n) {
1857   n->remove_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
1858   _for_post_loop_igvn.remove(n);
1859 }
1860 
1861 void Compile::process_for_post_loop_opts_igvn(PhaseIterGVN& igvn) {
1862   // Verify that all previous optimizations produced a valid graph
1863   // at least to this point, even if no loop optimizations were done.
1864   PhaseIdealLoop::verify(igvn);
1865 
1866   if (_print_phase_loop_opts) {
1867     print_method(PHASE_AFTER_LOOP_OPTS, 2);
1868   }
1869   C->set_post_loop_opts_phase(); // no more loop opts allowed
1870 
1871   assert(!C->major_progress(), "not cleared");
1872 
1873   if (_for_post_loop_igvn.length() > 0) {
1874     while (_for_post_loop_igvn.length() > 0) {
1875       Node* n = _for_post_loop_igvn.pop();
1876       n->remove_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
1877       igvn._worklist.push(n);
1878     }
1879     igvn.optimize();
1880     if (failing()) return;
1881     assert(_for_post_loop_igvn.length() == 0, "no more delayed nodes allowed");
1882     assert(C->parse_predicate_count() == 0, "all parse predicates should have been removed now");
1883 
1884     // Sometimes IGVN sets major progress (e.g., when processing loop nodes).
1885     if (C->major_progress()) {
1886       C->clear_major_progress(); // ensure that major progress is now clear
1887     }
1888   }
1889 }
1890 
1891 void Compile::record_for_merge_stores_igvn(Node* n) {
1892   if (!n->for_merge_stores_igvn()) {
1893     assert(!_for_merge_stores_igvn.contains(n), "duplicate");
1894     n->add_flag(Node::NodeFlags::Flag_for_merge_stores_igvn);
1895     _for_merge_stores_igvn.append(n);
1896   }
1897 }
1898 
1899 void Compile::remove_from_merge_stores_igvn(Node* n) {
1900   n->remove_flag(Node::NodeFlags::Flag_for_merge_stores_igvn);
1901   _for_merge_stores_igvn.remove(n);
1902 }
1903 
1904 // We need to wait with merging stores until RangeCheck smearing has removed the RangeChecks during
1905 // the post loops IGVN phase. If we do it earlier, then there may still be some RangeChecks between
1906 // the stores, and we merge the wrong sequence of stores.
1907 // Example:
1908 //   StoreI RangeCheck StoreI StoreI RangeCheck StoreI
1909 // Apply MergeStores:
1910 //   StoreI RangeCheck [   StoreL  ] RangeCheck StoreI
1911 // Remove more RangeChecks:
1912 //   StoreI            [   StoreL  ]            StoreI
1913 // But now it would have been better to do this instead:
1914 //   [         StoreL       ] [       StoreL         ]
1915 //
1916 // Note: we allow stores to merge in this dedicated IGVN round, and any later IGVN round,
1917 //       since we never unset _merge_stores_phase.
1918 void Compile::process_for_merge_stores_igvn(PhaseIterGVN& igvn) {
1919   C->set_merge_stores_phase();
1920 
1921   if (_for_merge_stores_igvn.length() > 0) {
1922     while (_for_merge_stores_igvn.length() > 0) {
1923       Node* n = _for_merge_stores_igvn.pop();
1924       n->remove_flag(Node::NodeFlags::Flag_for_merge_stores_igvn);
1925       igvn._worklist.push(n);
1926     }
1927     igvn.optimize();
1928     if (failing()) return;
1929     assert(_for_merge_stores_igvn.length() == 0, "no more delayed nodes allowed");
1930     print_method(PHASE_AFTER_MERGE_STORES, 3);
1931   }
1932 }
1933 
1934 void Compile::record_unstable_if_trap(UnstableIfTrap* trap) {
1935   if (OptimizeUnstableIf) {
1936     _unstable_if_traps.append(trap);
1937   }
1938 }
1939 
1940 void Compile::remove_useless_unstable_if_traps(Unique_Node_List& useful) {
1941   for (int i = _unstable_if_traps.length() - 1; i >= 0; i--) {
1942     UnstableIfTrap* trap = _unstable_if_traps.at(i);
1943     Node* n = trap->uncommon_trap();
1944     if (!useful.member(n)) {
1945       _unstable_if_traps.delete_at(i); // replaces i-th with last element which is known to be useful (already processed)
1946     }
1947   }
1948 }
1949 
1950 // Remove the unstable if trap associated with 'unc' from candidates. It is either dead
1951 // or fold-compares case. Return true if succeed or not found.
1952 //
1953 // In rare cases, the found trap has been processed. It is too late to delete it. Return
1954 // false and ask fold-compares to yield.
1955 //
1956 // 'fold-compares' may use the uncommon_trap of the dominating IfNode to cover the fused
1957 // IfNode. This breaks the unstable_if trap invariant: control takes the unstable path
1958 // when deoptimization does happen.
1959 bool Compile::remove_unstable_if_trap(CallStaticJavaNode* unc, bool yield) {
1960   for (int i = 0; i < _unstable_if_traps.length(); ++i) {
1961     UnstableIfTrap* trap = _unstable_if_traps.at(i);
1962     if (trap->uncommon_trap() == unc) {
1963       if (yield && trap->modified()) {
1964         return false;
1965       }
1966       _unstable_if_traps.delete_at(i);
1967       break;
1968     }
1969   }
1970   return true;
1971 }
1972 
1973 // Re-calculate unstable_if traps with the liveness of next_bci, which points to the unlikely path.
1974 // It needs to be done after igvn because fold-compares may fuse uncommon_traps and before renumbering.
1975 void Compile::process_for_unstable_if_traps(PhaseIterGVN& igvn) {
1976   for (int i = _unstable_if_traps.length() - 1; i >= 0; --i) {
1977     UnstableIfTrap* trap = _unstable_if_traps.at(i);
1978     CallStaticJavaNode* unc = trap->uncommon_trap();
1979     int next_bci = trap->next_bci();
1980     bool modified = trap->modified();
1981 
1982     if (next_bci != -1 && !modified) {
1983       assert(!_dead_node_list.test(unc->_idx), "changing a dead node!");
1984       JVMState* jvms = unc->jvms();
1985       ciMethod* method = jvms->method();
1986       ciBytecodeStream iter(method);
1987 
1988       iter.force_bci(jvms->bci());
1989       assert(next_bci == iter.next_bci() || next_bci == iter.get_dest(), "wrong next_bci at unstable_if");
1990       Bytecodes::Code c = iter.cur_bc();
1991       Node* lhs = nullptr;
1992       Node* rhs = nullptr;
1993       if (c == Bytecodes::_if_acmpeq || c == Bytecodes::_if_acmpne) {
1994         lhs = unc->peek_operand(0);
1995         rhs = unc->peek_operand(1);
1996       } else if (c == Bytecodes::_ifnull || c == Bytecodes::_ifnonnull) {
1997         lhs = unc->peek_operand(0);
1998       }
1999 
2000       ResourceMark rm;
2001       const MethodLivenessResult& live_locals = method->liveness_at_bci(next_bci);
2002       assert(live_locals.is_valid(), "broken liveness info");
2003       int len = (int)live_locals.size();
2004 
2005       for (int i = 0; i < len; i++) {
2006         Node* local = unc->local(jvms, i);
2007         // kill local using the liveness of next_bci.
2008         // give up when the local looks like an operand to secure reexecution.
2009         if (!live_locals.at(i) && !local->is_top() && local != lhs && local!= rhs) {
2010           uint idx = jvms->locoff() + i;
2011 #ifdef ASSERT
2012           if (PrintOpto && Verbose) {
2013             tty->print("[unstable_if] kill local#%d: ", idx);
2014             local->dump();
2015             tty->cr();
2016           }
2017 #endif
2018           igvn.replace_input_of(unc, idx, top());
2019           modified = true;
2020         }
2021       }
2022     }
2023 
2024     // keep the mondified trap for late query
2025     if (modified) {
2026       trap->set_modified();
2027     } else {
2028       _unstable_if_traps.delete_at(i);
2029     }
2030   }
2031   igvn.optimize();
2032 }
2033 
2034 // StringOpts and late inlining of string methods
2035 void Compile::inline_string_calls(bool parse_time) {
2036   {
2037     // remove useless nodes to make the usage analysis simpler
2038     ResourceMark rm;
2039     PhaseRemoveUseless pru(initial_gvn(), *igvn_worklist());
2040   }
2041 
2042   {
2043     ResourceMark rm;
2044     print_method(PHASE_BEFORE_STRINGOPTS, 3);
2045     PhaseStringOpts pso(initial_gvn());
2046     print_method(PHASE_AFTER_STRINGOPTS, 3);
2047   }
2048 
2049   // now inline anything that we skipped the first time around
2050   if (!parse_time) {
2051     _late_inlines_pos = _late_inlines.length();
2052   }
2053 
2054   while (_string_late_inlines.length() > 0) {
2055     CallGenerator* cg = _string_late_inlines.pop();
2056     cg->do_late_inline();
2057     if (failing())  return;
2058   }
2059   _string_late_inlines.trunc_to(0);
2060 }
2061 
2062 // Late inlining of boxing methods
2063 void Compile::inline_boxing_calls(PhaseIterGVN& igvn) {
2064   if (_boxing_late_inlines.length() > 0) {
2065     assert(has_boxed_value(), "inconsistent");
2066 
2067     set_inlining_incrementally(true);
2068 
2069     igvn_worklist()->ensure_empty(); // should be done with igvn
2070 
2071     _late_inlines_pos = _late_inlines.length();
2072 
2073     while (_boxing_late_inlines.length() > 0) {
2074       CallGenerator* cg = _boxing_late_inlines.pop();
2075       cg->do_late_inline();
2076       if (failing())  return;
2077     }
2078     _boxing_late_inlines.trunc_to(0);
2079 
2080     inline_incrementally_cleanup(igvn);
2081 
2082     set_inlining_incrementally(false);
2083   }
2084 }
2085 
2086 bool Compile::inline_incrementally_one() {
2087   assert(IncrementalInline, "incremental inlining should be on");
2088   assert(_late_inlines.length() > 0, "should have been checked by caller");
2089 
2090   TracePhase tp(_t_incrInline_inline);
2091 
2092   set_inlining_progress(false);
2093   set_do_cleanup(false);
2094 
2095   for (int i = 0; i < _late_inlines.length(); i++) {
2096     _late_inlines_pos = i+1;
2097     CallGenerator* cg = _late_inlines.at(i);
2098     bool is_scheduled_for_igvn_before = C->igvn_worklist()->member(cg->call_node());
2099     bool does_dispatch = cg->is_virtual_late_inline() || cg->is_mh_late_inline();
2100     if (inlining_incrementally() || does_dispatch) { // a call can be either inlined or strength-reduced to a direct call
2101       if (should_stress_inlining()) {
2102         // randomly add repeated inline attempt if stress-inlining
2103         cg->call_node()->set_generator(cg);
2104         C->igvn_worklist()->push(cg->call_node());
2105         continue;
2106       }
2107       cg->do_late_inline();
2108       assert(_late_inlines.at(i) == cg, "no insertions before current position allowed");
2109       if (failing()) {
2110         return false;
2111       } else if (inlining_progress()) {
2112         _late_inlines_pos = i+1; // restore the position in case new elements were inserted
2113         print_method(PHASE_INCREMENTAL_INLINE_STEP, 3, cg->call_node());
2114         break; // process one call site at a time
2115       } else {
2116         bool is_scheduled_for_igvn_after = C->igvn_worklist()->member(cg->call_node());
2117         if (!is_scheduled_for_igvn_before && is_scheduled_for_igvn_after) {
2118           // Avoid potential infinite loop if node already in the IGVN list
2119           assert(false, "scheduled for IGVN during inlining attempt");
2120         } else {
2121           // Ensure call node has not disappeared from IGVN worklist during a failed inlining attempt
2122           assert(!is_scheduled_for_igvn_before || is_scheduled_for_igvn_after, "call node removed from IGVN list during inlining pass");
2123           cg->call_node()->set_generator(cg);
2124         }
2125       }
2126     } else {
2127       // Ignore late inline direct calls when inlining is not allowed.
2128       // They are left in the late inline list when node budget is exhausted until the list is fully drained.
2129     }
2130   }
2131   // Remove processed elements.
2132   _late_inlines.remove_till(_late_inlines_pos);
2133   _late_inlines_pos = 0;
2134 
2135   assert(inlining_progress() || _late_inlines.length() == 0, "no progress");
2136 
2137   bool needs_cleanup = do_cleanup() || over_inlining_cutoff();
2138 
2139   set_inlining_progress(false);
2140   set_do_cleanup(false);
2141 
2142   bool force_cleanup = directive()->IncrementalInlineForceCleanupOption;
2143   return (_late_inlines.length() > 0) && !needs_cleanup && !force_cleanup;
2144 }
2145 
2146 void Compile::inline_incrementally_cleanup(PhaseIterGVN& igvn) {
2147   {
2148     TracePhase tp(_t_incrInline_pru);
2149     ResourceMark rm;
2150     PhaseRemoveUseless pru(initial_gvn(), *igvn_worklist());
2151   }
2152   {
2153     TracePhase tp(_t_incrInline_igvn);
2154     igvn.reset();
2155     igvn.optimize();
2156     if (failing()) return;
2157   }
2158   print_method(PHASE_INCREMENTAL_INLINE_CLEANUP, 3);
2159 }
2160 
2161 template<typename E>
2162 static void shuffle_array(Compile& C, GrowableArray<E>& array) {
2163   if (array.length() < 2) {
2164     return;
2165   }
2166   for (uint i = array.length() - 1; i >= 1; i--) {
2167     uint j = C.random() % (i + 1);
2168     swap(array.at(i), array.at(j));
2169   }
2170 }
2171 
2172 void Compile::shuffle_late_inlines() {
2173   shuffle_array(*C, _late_inlines);
2174 }
2175 
2176 // Perform incremental inlining until bound on number of live nodes is reached
2177 void Compile::inline_incrementally(PhaseIterGVN& igvn) {
2178   TracePhase tp(_t_incrInline);
2179 
2180   set_inlining_incrementally(true);
2181   uint low_live_nodes = 0;
2182 
2183   if (StressIncrementalInlining) {
2184     shuffle_late_inlines();
2185   }
2186 
2187   while (_late_inlines.length() > 0) {
2188     if (live_nodes() > node_count_inlining_cutoff()) {
2189       if (low_live_nodes < node_count_inlining_cutoff() * 8 / 10) {
2190         TracePhase tp(_t_incrInline_ideal);
2191         // PhaseIdealLoop is expensive so we only try it once we are
2192         // out of live nodes and we only try it again if the previous
2193         // helped got the number of nodes down significantly
2194         PhaseIdealLoop::optimize(igvn, LoopOptsNone);
2195         if (failing())  return;
2196         low_live_nodes = live_nodes();
2197         _major_progress = true;
2198       }
2199 
2200       if (live_nodes() > node_count_inlining_cutoff()) {
2201         bool do_print_inlining = print_inlining() || print_intrinsics();
2202         if (do_print_inlining || log() != nullptr) {
2203           // Print inlining message for candidates that we couldn't inline for lack of space.
2204           for (int i = 0; i < _late_inlines.length(); i++) {
2205             CallGenerator* cg = _late_inlines.at(i);
2206             const char* msg = "live nodes > LiveNodeCountInliningCutoff";
2207             if (do_print_inlining) {
2208               inline_printer()->record(cg->method(), cg->call_node()->jvms(), InliningResult::FAILURE, msg);
2209             }
2210             log_late_inline_failure(cg, msg);
2211           }
2212         }
2213         break; // finish
2214       }
2215     }
2216 
2217     igvn_worklist()->ensure_empty(); // should be done with igvn
2218 
2219     if (_late_inlines.length() == 0) {
2220       break; // no more progress
2221     }
2222 
2223     while (inline_incrementally_one()) {
2224       assert(!failing_internal() || failure_is_artificial(), "inconsistent");
2225     }
2226     if (failing())  return;
2227 
2228     inline_incrementally_cleanup(igvn);
2229 
2230     print_method(PHASE_INCREMENTAL_INLINE_STEP, 3);
2231 
2232     if (failing())  return;
2233   }
2234 
2235   igvn_worklist()->ensure_empty(); // should be done with igvn
2236 
2237   if (_string_late_inlines.length() > 0) {
2238     assert(has_stringbuilder(), "inconsistent");
2239 
2240     inline_string_calls(false);
2241 
2242     if (failing())  return;
2243 
2244     inline_incrementally_cleanup(igvn);
2245   }
2246 
2247   set_inlining_incrementally(false);
2248 }
2249 
2250 void Compile::process_late_inline_calls_no_inline(PhaseIterGVN& igvn) {
2251   // "inlining_incrementally() == false" is used to signal that no inlining is allowed
2252   // (see LateInlineVirtualCallGenerator::do_late_inline_check() for details).
2253   // Tracking and verification of modified nodes is disabled by setting "_modified_nodes == nullptr"
2254   // as if "inlining_incrementally() == true" were set.
2255   assert(inlining_incrementally() == false, "not allowed");
2256   assert(_modified_nodes == nullptr, "not allowed");
2257   assert(_late_inlines.length() > 0, "sanity");
2258 
2259   if (StressIncrementalInlining) {
2260     shuffle_late_inlines();
2261   }
2262 
2263   while (_late_inlines.length() > 0) {
2264     igvn_worklist()->ensure_empty(); // should be done with igvn
2265 
2266     while (inline_incrementally_one()) {
2267       assert(!failing_internal() || failure_is_artificial(), "inconsistent");
2268     }
2269     if (failing())  return;
2270 
2271     inline_incrementally_cleanup(igvn);
2272   }
2273 }
2274 
2275 bool Compile::optimize_loops(PhaseIterGVN& igvn, LoopOptsMode mode) {
2276   if (_loop_opts_cnt > 0) {
2277     while (major_progress() && (_loop_opts_cnt > 0)) {
2278       TracePhase tp(_t_idealLoop);
2279       PhaseIdealLoop::optimize(igvn, mode);
2280       _loop_opts_cnt--;
2281       if (failing())  return false;
2282       if (major_progress()) {
2283         print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
2284       }
2285     }
2286   }
2287   return true;
2288 }
2289 
2290 // Remove edges from "root" to each SafePoint at a backward branch.
2291 // They were inserted during parsing (see add_safepoint()) to make
2292 // infinite loops without calls or exceptions visible to root, i.e.,
2293 // useful.
2294 void Compile::remove_root_to_sfpts_edges(PhaseIterGVN& igvn) {
2295   Node *r = root();
2296   if (r != nullptr) {
2297     for (uint i = r->req(); i < r->len(); ++i) {
2298       Node *n = r->in(i);
2299       if (n != nullptr && n->is_SafePoint()) {
2300         r->rm_prec(i);
2301         if (n->outcnt() == 0) {
2302           igvn.remove_dead_node(n, PhaseIterGVN::NodeOrigin::Graph);
2303         }
2304         --i;
2305       }
2306     }
2307     // Parsing may have added top inputs to the root node (Path
2308     // leading to the Halt node proven dead). Make sure we get a
2309     // chance to clean them up.
2310     igvn._worklist.push(r);
2311     igvn.optimize();
2312   }
2313 }
2314 
2315 //------------------------------Optimize---------------------------------------
2316 // Given a graph, optimize it.
2317 void Compile::Optimize() {
2318   TracePhase tp(_t_optimizer);
2319 
2320 #ifndef PRODUCT
2321   if (env()->break_at_compile()) {
2322     BREAKPOINT;
2323   }
2324 
2325 #endif
2326 
2327   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
2328 #ifdef ASSERT
2329   bs->verify_gc_barriers(this, BarrierSetC2::BeforeOptimize);
2330 #endif
2331 
2332   ResourceMark rm;
2333 
2334   NOT_PRODUCT( verify_graph_edges(); )
2335 
2336   print_method(PHASE_AFTER_PARSING, 1);
2337 
2338  {
2339   // Iterative Global Value Numbering, including ideal transforms
2340   PhaseIterGVN igvn;
2341 #ifdef ASSERT
2342   _modified_nodes = new (comp_arena()) Unique_Node_List(comp_arena());
2343 #endif
2344   {
2345     TracePhase tp(_t_iterGVN);
2346     igvn.optimize(true);
2347   }
2348 
2349   if (failing())  return;
2350 
2351   print_method(PHASE_ITER_GVN1, 2);
2352 
2353   process_for_unstable_if_traps(igvn);
2354 
2355   if (failing())  return;
2356 
2357   inline_incrementally(igvn);
2358 
2359   print_method(PHASE_INCREMENTAL_INLINE, 2);
2360 
2361   if (failing())  return;
2362 
2363   if (eliminate_boxing()) {
2364     // Inline valueOf() methods now.
2365     inline_boxing_calls(igvn);
2366 
2367     if (failing())  return;
2368 
2369     if (AlwaysIncrementalInline || StressIncrementalInlining) {
2370       inline_incrementally(igvn);
2371     }
2372 
2373     print_method(PHASE_INCREMENTAL_BOXING_INLINE, 2);
2374 
2375     if (failing())  return;
2376   }
2377 
2378   // Remove the speculative part of types and clean up the graph from
2379   // the extra CastPP nodes whose only purpose is to carry them. Do
2380   // that early so that optimizations are not disrupted by the extra
2381   // CastPP nodes.
2382   remove_speculative_types(igvn);
2383 
2384   if (failing())  return;
2385 
2386   // No more new expensive nodes will be added to the list from here
2387   // so keep only the actual candidates for optimizations.
2388   cleanup_expensive_nodes(igvn);
2389 
2390   if (failing())  return;
2391 
2392   assert(EnableVectorSupport || !has_vbox_nodes(), "sanity");
2393   if (EnableVectorSupport && has_vbox_nodes()) {
2394     TracePhase tp(_t_vector);
2395     PhaseVector pv(igvn);
2396     pv.optimize_vector_boxes();
2397     if (failing())  return;
2398     print_method(PHASE_ITER_GVN_AFTER_VECTOR, 2);
2399   }
2400   assert(!has_vbox_nodes(), "sanity");
2401 
2402   if (!failing() && RenumberLiveNodes && live_nodes() + NodeLimitFudgeFactor < unique()) {
2403     Compile::TracePhase tp(_t_renumberLive);
2404     igvn_worklist()->ensure_empty(); // should be done with igvn
2405     {
2406       ResourceMark rm;
2407       PhaseRenumberLive prl(initial_gvn(), *igvn_worklist());
2408     }
2409     igvn.reset();
2410     igvn.optimize(true);
2411     if (failing()) return;
2412   }
2413 
2414   // Now that all inlining is over and no PhaseRemoveUseless will run, cut edge from root to loop
2415   // safepoints
2416   remove_root_to_sfpts_edges(igvn);
2417 
2418   if (failing())  return;
2419 
2420   _print_phase_loop_opts = has_loops();
2421   if (_print_phase_loop_opts) {
2422     print_method(PHASE_BEFORE_LOOP_OPTS, 2);
2423   }
2424 
2425   // Perform escape analysis
2426   if (do_escape_analysis() && ConnectionGraph::has_candidates(this)) {
2427     if (has_loops()) {
2428       // Cleanup graph (remove dead nodes).
2429       TracePhase tp(_t_idealLoop);
2430       PhaseIdealLoop::optimize(igvn, LoopOptsMaxUnroll);
2431       if (failing())  return;
2432     }
2433     bool progress;
2434     print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
2435     do {
2436       ConnectionGraph::do_analysis(this, &igvn);
2437 
2438       if (failing())  return;
2439 
2440       int mcount = macro_count(); // Record number of allocations and locks before IGVN
2441 
2442       // Optimize out fields loads from scalar replaceable allocations.
2443       igvn.optimize(true);
2444       print_method(PHASE_ITER_GVN_AFTER_EA, 2);
2445 
2446       if (failing()) return;
2447 
2448       if (congraph() != nullptr && macro_count() > 0) {
2449         TracePhase tp(_t_macroEliminate);
2450         PhaseMacroExpand mexp(igvn);
2451         mexp.eliminate_macro_nodes();
2452         if (failing()) return;
2453         print_method(PHASE_AFTER_MACRO_ELIMINATION, 2);
2454 
2455         igvn.set_delay_transform(false);
2456         igvn.optimize();
2457         if (failing()) return;
2458 
2459         print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
2460       }
2461 
2462       ConnectionGraph::verify_ram_nodes(this, root());
2463       if (failing())  return;
2464 
2465       progress = do_iterative_escape_analysis() &&
2466                  (macro_count() < mcount) &&
2467                  ConnectionGraph::has_candidates(this);
2468       // Try again if candidates exist and made progress
2469       // by removing some allocations and/or locks.
2470     } while (progress);
2471   }
2472 
2473   // Loop transforms on the ideal graph.  Range Check Elimination,
2474   // peeling, unrolling, etc.
2475 
2476   // Set loop opts counter
2477   if((_loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
2478     {
2479       TracePhase tp(_t_idealLoop);
2480       PhaseIdealLoop::optimize(igvn, LoopOptsDefault);
2481       _loop_opts_cnt--;
2482       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP1, 2);
2483       if (failing())  return;
2484     }
2485     // Loop opts pass if partial peeling occurred in previous pass
2486     if(PartialPeelLoop && major_progress() && (_loop_opts_cnt > 0)) {
2487       TracePhase tp(_t_idealLoop);
2488       PhaseIdealLoop::optimize(igvn, LoopOptsSkipSplitIf);
2489       _loop_opts_cnt--;
2490       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP2, 2);
2491       if (failing())  return;
2492     }
2493     // Loop opts pass for loop-unrolling before CCP
2494     if(major_progress() && (_loop_opts_cnt > 0)) {
2495       TracePhase tp(_t_idealLoop);
2496       PhaseIdealLoop::optimize(igvn, LoopOptsSkipSplitIf);
2497       _loop_opts_cnt--;
2498       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP3, 2);
2499     }
2500     if (!failing()) {
2501       // Verify that last round of loop opts produced a valid graph
2502       PhaseIdealLoop::verify(igvn);
2503     }
2504   }
2505   if (failing())  return;
2506 
2507   // Conditional Constant Propagation;
2508   print_method(PHASE_BEFORE_CCP1, 2);
2509   PhaseCCP ccp( &igvn );
2510   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
2511   {
2512     TracePhase tp(_t_ccp);
2513     ccp.do_transform();
2514   }
2515   print_method(PHASE_CCP1, 2);
2516 
2517   assert( true, "Break here to ccp.dump_old2new_map()");
2518 
2519   // Iterative Global Value Numbering, including ideal transforms
2520   {
2521     TracePhase tp(_t_iterGVN2);
2522     igvn.reset_from_igvn(&ccp);
2523     igvn.optimize(true);
2524   }
2525   print_method(PHASE_ITER_GVN2, 2);
2526 
2527   if (failing())  return;
2528 
2529   // Loop transforms on the ideal graph.  Range Check Elimination,
2530   // peeling, unrolling, etc.
2531   if (!optimize_loops(igvn, LoopOptsDefault)) {
2532     return;
2533   }
2534 
2535   C->clear_major_progress(); // ensure that major progress is now clear
2536 
2537   process_for_post_loop_opts_igvn(igvn);
2538 
2539   if (failing())  return;
2540 
2541   // Once loop optimizations are over, it is safe to get rid of all reachability fence nodes and
2542   // migrate reachability edges to safepoints.
2543   if (OptimizeReachabilityFences && _reachability_fences.length() > 0) {
2544     TracePhase tp1(_t_idealLoop);
2545     TracePhase tp2(_t_reachability);
2546     PhaseIdealLoop::optimize(igvn, PostLoopOptsExpandReachabilityFences);
2547     print_method(PHASE_EXPAND_REACHABILITY_FENCES, 2);
2548     if (failing())  return;
2549     assert(_reachability_fences.length() == 0 || PreserveReachabilityFencesOnConstants, "no RF nodes allowed");
2550   }
2551 
2552   process_for_merge_stores_igvn(igvn);
2553 
2554   if (failing())  return;
2555 
2556 #ifdef ASSERT
2557   bs->verify_gc_barriers(this, BarrierSetC2::BeforeMacroExpand);
2558 #endif
2559 
2560   {
2561     TracePhase tp(_t_macroExpand);
2562     print_method(PHASE_BEFORE_MACRO_EXPANSION, 3);
2563     PhaseMacroExpand  mex(igvn);
2564     // Do not allow new macro nodes once we start to eliminate and expand
2565     C->reset_allow_macro_nodes();
2566     // Last attempt to eliminate macro nodes before expand
2567     mex.eliminate_macro_nodes();
2568     if (failing()) {
2569       return;
2570     }
2571     mex.eliminate_opaque_looplimit_macro_nodes();
2572     if (failing()) {
2573       return;
2574     }
2575     print_method(PHASE_AFTER_MACRO_ELIMINATION, 2);
2576     if (mex.expand_macro_nodes()) {
2577       assert(failing(), "must bail out w/ explicit message");
2578       return;
2579     }
2580     print_method(PHASE_AFTER_MACRO_EXPANSION, 2);
2581   }
2582 
2583   {
2584     TracePhase tp(_t_barrierExpand);
2585     if (bs->expand_barriers(this, igvn)) {
2586       assert(failing(), "must bail out w/ explicit message");
2587       return;
2588     }
2589     print_method(PHASE_BARRIER_EXPANSION, 2);
2590   }
2591 
2592   if (C->max_vector_size() > 0) {
2593     C->optimize_logic_cones(igvn);
2594     igvn.optimize();
2595     if (failing()) return;
2596   }
2597 
2598   DEBUG_ONLY( _modified_nodes = nullptr; )
2599 
2600   assert(igvn._worklist.size() == 0, "not empty");
2601 
2602   if (_late_inlines.length() > 0) {
2603     // More opportunities to optimize virtual and MH calls.
2604     // Though it's maybe too late to perform inlining, strength-reducing them to direct calls is still an option.
2605     process_late_inline_calls_no_inline(igvn);
2606     if (failing())  return;
2607   }
2608   assert(_late_inlines.length() == 0, "late inline queue must be drained");
2609  } // (End scope of igvn; run destructor if necessary for asserts.)
2610 
2611  check_no_dead_use();
2612 
2613  // We will never use the NodeHash table any more. Clear it so that final_graph_reshaping does not have
2614  // to remove hashes to unlock nodes for modifications.
2615  C->node_hash()->clear();
2616 
2617  // A method with only infinite loops has no edges entering loops from root
2618  {
2619    TracePhase tp(_t_graphReshaping);
2620    if (final_graph_reshaping()) {
2621      assert(failing(), "must bail out w/ explicit message");
2622      return;
2623    }
2624  }
2625 
2626  print_method(PHASE_OPTIMIZE_FINISHED, 2);
2627  DEBUG_ONLY(set_phase_optimize_finished();)
2628 }
2629 
2630 #ifdef ASSERT
2631 void Compile::check_no_dead_use() const {
2632   ResourceMark rm;
2633   Unique_Node_List wq;
2634   wq.push(root());
2635   for (uint i = 0; i < wq.size(); ++i) {
2636     Node* n = wq.at(i);
2637     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
2638       Node* u = n->fast_out(j);
2639       if (u->outcnt() == 0 && !u->is_Con()) {
2640         u->dump();
2641         fatal("no reachable node should have no use");
2642       }
2643       wq.push(u);
2644     }
2645   }
2646 }
2647 #endif
2648 
2649 void Compile::inline_vector_reboxing_calls() {
2650   if (C->_vector_reboxing_late_inlines.length() > 0) {
2651     _late_inlines_pos = C->_late_inlines.length();
2652     while (_vector_reboxing_late_inlines.length() > 0) {
2653       CallGenerator* cg = _vector_reboxing_late_inlines.pop();
2654       cg->do_late_inline();
2655       if (failing())  return;
2656       print_method(PHASE_INLINE_VECTOR_REBOX, 3, cg->call_node());
2657     }
2658     _vector_reboxing_late_inlines.trunc_to(0);
2659   }
2660 }
2661 
2662 bool Compile::has_vbox_nodes() {
2663   if (C->_vector_reboxing_late_inlines.length() > 0) {
2664     return true;
2665   }
2666   for (int macro_idx = C->macro_count() - 1; macro_idx >= 0; macro_idx--) {
2667     Node * n = C->macro_node(macro_idx);
2668     assert(n->is_macro(), "only macro nodes expected here");
2669     if (n->Opcode() == Op_VectorUnbox || n->Opcode() == Op_VectorBox || n->Opcode() == Op_VectorBoxAllocate) {
2670       return true;
2671     }
2672   }
2673   return false;
2674 }
2675 
2676 //---------------------------- Bitwise operation packing optimization ---------------------------
2677 
2678 static bool is_vector_unary_bitwise_op(Node* n) {
2679   return n->Opcode() == Op_XorV &&
2680          VectorNode::is_vector_bitwise_not_pattern(n);
2681 }
2682 
2683 static bool is_vector_binary_bitwise_op(Node* n) {
2684   switch (n->Opcode()) {
2685     case Op_AndV:
2686     case Op_OrV:
2687       return true;
2688 
2689     case Op_XorV:
2690       return !is_vector_unary_bitwise_op(n);
2691 
2692     default:
2693       return false;
2694   }
2695 }
2696 
2697 static bool is_vector_ternary_bitwise_op(Node* n) {
2698   return n->Opcode() == Op_MacroLogicV;
2699 }
2700 
2701 static bool is_vector_bitwise_op(Node* n) {
2702   return is_vector_unary_bitwise_op(n)  ||
2703          is_vector_binary_bitwise_op(n) ||
2704          is_vector_ternary_bitwise_op(n);
2705 }
2706 
2707 static bool is_vector_bitwise_cone_root(Node* n) {
2708   if (n->bottom_type()->isa_pvectmask() || !is_vector_bitwise_op(n)) {
2709     return false;
2710   }
2711   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2712     if (is_vector_bitwise_op(n->fast_out(i))) {
2713       return false;
2714     }
2715   }
2716   return true;
2717 }
2718 
2719 static uint collect_unique_inputs(Node* n, Unique_Node_List& inputs) {
2720   uint cnt = 0;
2721   if (is_vector_bitwise_op(n)) {
2722     uint inp_cnt = n->is_predicated_vector() ? n->req()-1 : n->req();
2723     if (VectorNode::is_vector_bitwise_not_pattern(n)) {
2724       for (uint i = 1; i < inp_cnt; i++) {
2725         Node* in = n->in(i);
2726         bool skip = VectorNode::is_all_ones_vector(in);
2727         if (!skip && !inputs.member(in)) {
2728           inputs.push(in);
2729           cnt++;
2730         }
2731       }
2732       assert(cnt <= 1, "not unary");
2733     } else {
2734       uint last_req = inp_cnt;
2735       if (is_vector_ternary_bitwise_op(n)) {
2736         last_req = inp_cnt - 1; // skip last input
2737       }
2738       for (uint i = 1; i < last_req; i++) {
2739         Node* def = n->in(i);
2740         if (!inputs.member(def)) {
2741           inputs.push(def);
2742           cnt++;
2743         }
2744       }
2745     }
2746   } else { // not a bitwise operations
2747     if (!inputs.member(n)) {
2748       inputs.push(n);
2749       cnt++;
2750     }
2751   }
2752   return cnt;
2753 }
2754 
2755 void Compile::collect_logic_cone_roots(Unique_Node_List& list) {
2756   Unique_Node_List useful_nodes;
2757   C->identify_useful_nodes(useful_nodes);
2758 
2759   for (uint i = 0; i < useful_nodes.size(); i++) {
2760     Node* n = useful_nodes.at(i);
2761     if (is_vector_bitwise_cone_root(n)) {
2762       list.push(n);
2763     }
2764   }
2765 }
2766 
2767 Node* Compile::xform_to_MacroLogicV(PhaseIterGVN& igvn,
2768                                     const TypeVect* vt,
2769                                     Unique_Node_List& partition,
2770                                     Unique_Node_List& inputs) {
2771   assert(partition.size() == 2 || partition.size() == 3, "not supported");
2772   assert(inputs.size()    == 2 || inputs.size()    == 3, "not supported");
2773   assert(Matcher::match_rule_supported_vector(Op_MacroLogicV, vt->length(), vt->element_basic_type()), "not supported");
2774 
2775   Node* in1 = inputs.at(0);
2776   Node* in2 = inputs.at(1);
2777   Node* in3 = (inputs.size() == 3 ? inputs.at(2) : in2);
2778 
2779   uint func = compute_truth_table(partition, inputs);
2780 
2781   Node* pn = partition.at(partition.size() - 1);
2782   Node* mask = pn->is_predicated_vector() ? pn->in(pn->req()-1) : nullptr;
2783   return igvn.transform(MacroLogicVNode::make(igvn, in1, in2, in3, mask, func, vt));
2784 }
2785 
2786 static uint extract_bit(uint func, uint pos) {
2787   return (func & (1 << pos)) >> pos;
2788 }
2789 
2790 //
2791 //  A macro logic node represents a truth table. It has 4 inputs,
2792 //  First three inputs corresponds to 3 columns of a truth table
2793 //  and fourth input captures the logic function.
2794 //
2795 //  eg.  fn = (in1 AND in2) OR in3;
2796 //
2797 //      MacroNode(in1,in2,in3,fn)
2798 //
2799 //  -----------------
2800 //  in1 in2 in3  fn
2801 //  -----------------
2802 //  0    0   0    0
2803 //  0    0   1    1
2804 //  0    1   0    0
2805 //  0    1   1    1
2806 //  1    0   0    0
2807 //  1    0   1    1
2808 //  1    1   0    1
2809 //  1    1   1    1
2810 //
2811 
2812 uint Compile::eval_macro_logic_op(uint func, uint in1 , uint in2, uint in3) {
2813   int res = 0;
2814   for (int i = 0; i < 8; i++) {
2815     int bit1 = extract_bit(in1, i);
2816     int bit2 = extract_bit(in2, i);
2817     int bit3 = extract_bit(in3, i);
2818 
2819     int func_bit_pos = (bit1 << 2 | bit2 << 1 | bit3);
2820     int func_bit = extract_bit(func, func_bit_pos);
2821 
2822     res |= func_bit << i;
2823   }
2824   return res;
2825 }
2826 
2827 static uint eval_operand(Node* n, HashTable<Node*,uint>& eval_map) {
2828   assert(n != nullptr, "");
2829   assert(eval_map.contains(n), "absent");
2830   return *(eval_map.get(n));
2831 }
2832 
2833 static void eval_operands(Node* n,
2834                           uint& func1, uint& func2, uint& func3,
2835                           HashTable<Node*,uint>& eval_map) {
2836   assert(is_vector_bitwise_op(n), "");
2837 
2838   if (is_vector_unary_bitwise_op(n)) {
2839     Node* opnd = n->in(1);
2840     if (VectorNode::is_vector_bitwise_not_pattern(n) && VectorNode::is_all_ones_vector(opnd)) {
2841       opnd = n->in(2);
2842     }
2843     func1 = eval_operand(opnd, eval_map);
2844   } else if (is_vector_binary_bitwise_op(n)) {
2845     func1 = eval_operand(n->in(1), eval_map);
2846     func2 = eval_operand(n->in(2), eval_map);
2847   } else {
2848     assert(is_vector_ternary_bitwise_op(n), "unknown operation");
2849     func1 = eval_operand(n->in(1), eval_map);
2850     func2 = eval_operand(n->in(2), eval_map);
2851     func3 = eval_operand(n->in(3), eval_map);
2852   }
2853 }
2854 
2855 uint Compile::compute_truth_table(Unique_Node_List& partition, Unique_Node_List& inputs) {
2856   assert(inputs.size() <= 3, "sanity");
2857   ResourceMark rm;
2858   uint res = 0;
2859   HashTable<Node*,uint> eval_map;
2860 
2861   // Populate precomputed functions for inputs.
2862   // Each input corresponds to one column of 3 input truth-table.
2863   uint input_funcs[] = { 0xAA,   // (_, _, c) -> c
2864                          0xCC,   // (_, b, _) -> b
2865                          0xF0 }; // (a, _, _) -> a
2866   for (uint i = 0; i < inputs.size(); i++) {
2867     eval_map.put(inputs.at(i), input_funcs[2-i]);
2868   }
2869 
2870   for (uint i = 0; i < partition.size(); i++) {
2871     Node* n = partition.at(i);
2872 
2873     uint func1 = 0, func2 = 0, func3 = 0;
2874     eval_operands(n, func1, func2, func3, eval_map);
2875 
2876     switch (n->Opcode()) {
2877       case Op_OrV:
2878         assert(func3 == 0, "not binary");
2879         res = func1 | func2;
2880         break;
2881       case Op_AndV:
2882         assert(func3 == 0, "not binary");
2883         res = func1 & func2;
2884         break;
2885       case Op_XorV:
2886         if (VectorNode::is_vector_bitwise_not_pattern(n)) {
2887           assert(func2 == 0 && func3 == 0, "not unary");
2888           res = (~func1) & 0xFF;
2889         } else {
2890           assert(func3 == 0, "not binary");
2891           res = func1 ^ func2;
2892         }
2893         break;
2894       case Op_MacroLogicV:
2895         // Ordering of inputs may change during evaluation of sub-tree
2896         // containing MacroLogic node as a child node, thus a re-evaluation
2897         // makes sure that function is evaluated in context of current
2898         // inputs.
2899         res = eval_macro_logic_op(n->in(4)->get_int(), func1, func2, func3);
2900         break;
2901 
2902       default: assert(false, "not supported: %s", n->Name());
2903     }
2904     assert(res <= 0xFF, "invalid");
2905     eval_map.put(n, res);
2906   }
2907   return res;
2908 }
2909 
2910 // Criteria under which nodes gets packed into a macro logic node:-
2911 //  1) Parent and both child nodes are all unmasked or masked with
2912 //     same predicates.
2913 //  2) Masked parent can be packed with left child if it is predicated
2914 //     and both have same predicates.
2915 //  3) Masked parent can be packed with right child if its un-predicated
2916 //     or has matching predication condition.
2917 //  4) An unmasked parent can be packed with an unmasked child.
2918 bool Compile::compute_logic_cone(Node* n, Unique_Node_List& partition, Unique_Node_List& inputs) {
2919   assert(partition.size() == 0, "not empty");
2920   assert(inputs.size() == 0, "not empty");
2921   if (is_vector_ternary_bitwise_op(n)) {
2922     return false;
2923   }
2924 
2925   bool is_unary_op = is_vector_unary_bitwise_op(n);
2926   if (is_unary_op) {
2927     assert(collect_unique_inputs(n, inputs) == 1, "not unary");
2928     return false; // too few inputs
2929   }
2930 
2931   bool pack_left_child = true;
2932   bool pack_right_child = true;
2933 
2934   bool left_child_LOP = is_vector_bitwise_op(n->in(1));
2935   bool right_child_LOP = is_vector_bitwise_op(n->in(2));
2936 
2937   int left_child_input_cnt = 0;
2938   int right_child_input_cnt = 0;
2939 
2940   bool parent_is_predicated = n->is_predicated_vector();
2941   bool left_child_predicated = n->in(1)->is_predicated_vector();
2942   bool right_child_predicated = n->in(2)->is_predicated_vector();
2943 
2944   Node* parent_pred = parent_is_predicated ? n->in(n->req()-1) : nullptr;
2945   Node* left_child_pred = left_child_predicated ? n->in(1)->in(n->in(1)->req()-1) : nullptr;
2946   Node* right_child_pred = right_child_predicated ? n->in(1)->in(n->in(1)->req()-1) : nullptr;
2947 
2948   do {
2949     if (pack_left_child && left_child_LOP &&
2950         ((!parent_is_predicated && !left_child_predicated) ||
2951         ((parent_is_predicated && left_child_predicated &&
2952           parent_pred == left_child_pred)))) {
2953        partition.push(n->in(1));
2954        left_child_input_cnt = collect_unique_inputs(n->in(1), inputs);
2955     } else {
2956        inputs.push(n->in(1));
2957        left_child_input_cnt = 1;
2958     }
2959 
2960     if (pack_right_child && right_child_LOP &&
2961         (!right_child_predicated ||
2962          (right_child_predicated && parent_is_predicated &&
2963           parent_pred == right_child_pred))) {
2964        partition.push(n->in(2));
2965        right_child_input_cnt = collect_unique_inputs(n->in(2), inputs);
2966     } else {
2967        inputs.push(n->in(2));
2968        right_child_input_cnt = 1;
2969     }
2970 
2971     if (inputs.size() > 3) {
2972       assert(partition.size() > 0, "");
2973       inputs.clear();
2974       partition.clear();
2975       if (left_child_input_cnt > right_child_input_cnt) {
2976         pack_left_child = false;
2977       } else {
2978         pack_right_child = false;
2979       }
2980     } else {
2981       break;
2982     }
2983   } while(true);
2984 
2985   if(partition.size()) {
2986     partition.push(n);
2987   }
2988 
2989   return (partition.size() == 2 || partition.size() == 3) &&
2990          (inputs.size()    == 2 || inputs.size()    == 3);
2991 }
2992 
2993 void Compile::process_logic_cone_root(PhaseIterGVN &igvn, Node *n, VectorSet &visited) {
2994   assert(is_vector_bitwise_op(n), "not a root");
2995 
2996   visited.set(n->_idx);
2997 
2998   // 1) Do a DFS walk over the logic cone.
2999   for (uint i = 1; i < n->req(); i++) {
3000     Node* in = n->in(i);
3001     if (!visited.test(in->_idx) && is_vector_bitwise_op(in)) {
3002       process_logic_cone_root(igvn, in, visited);
3003     }
3004   }
3005 
3006   // 2) Bottom up traversal: Merge node[s] with
3007   // the parent to form macro logic node.
3008   Unique_Node_List partition;
3009   Unique_Node_List inputs;
3010   if (compute_logic_cone(n, partition, inputs)) {
3011     const TypeVect* vt = n->bottom_type()->is_vect();
3012     Node* pn = partition.at(partition.size() - 1);
3013     Node* mask = pn->is_predicated_vector() ? pn->in(pn->req()-1) : nullptr;
3014     if (mask == nullptr ||
3015         Matcher::match_rule_supported_vector_masked(Op_MacroLogicV, vt->length(), vt->element_basic_type())) {
3016       Node* macro_logic = xform_to_MacroLogicV(igvn, vt, partition, inputs);
3017       VectorNode::trace_new_vector(macro_logic, "MacroLogic");
3018       igvn.replace_node(n, macro_logic);
3019     }
3020   }
3021 }
3022 
3023 void Compile::optimize_logic_cones(PhaseIterGVN &igvn) {
3024   ResourceMark rm;
3025   if (Matcher::match_rule_supported(Op_MacroLogicV)) {
3026     Unique_Node_List list;
3027     collect_logic_cone_roots(list);
3028 
3029     while (list.size() > 0) {
3030       Node* n = list.pop();
3031       const TypeVect* vt = n->bottom_type()->is_vect();
3032       bool supported = Matcher::match_rule_supported_vector(Op_MacroLogicV, vt->length(), vt->element_basic_type());
3033       if (supported) {
3034         VectorSet visited(comp_arena());
3035         process_logic_cone_root(igvn, n, visited);
3036       }
3037     }
3038   }
3039 }
3040 
3041 //------------------------------Code_Gen---------------------------------------
3042 // Given a graph, generate code for it
3043 void Compile::Code_Gen() {
3044   if (failing()) {
3045     return;
3046   }
3047 
3048   // Perform instruction selection.  You might think we could reclaim Matcher
3049   // memory PDQ, but actually the Matcher is used in generating spill code.
3050   // Internals of the Matcher (including some VectorSets) must remain live
3051   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
3052   // set a bit in reclaimed memory.
3053 
3054   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
3055   // nodes.  Mapping is only valid at the root of each matched subtree.
3056   NOT_PRODUCT( verify_graph_edges(); )
3057 
3058   Matcher matcher;
3059   _matcher = &matcher;
3060   {
3061     TracePhase tp(_t_matcher);
3062     matcher.match();
3063     if (failing()) {
3064       return;
3065     }
3066   }
3067   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
3068   // nodes.  Mapping is only valid at the root of each matched subtree.
3069   NOT_PRODUCT( verify_graph_edges(); )
3070 
3071   // If you have too many nodes, or if matching has failed, bail out
3072   check_node_count(0, "out of nodes matching instructions");
3073   if (failing()) {
3074     return;
3075   }
3076 
3077   print_method(PHASE_MATCHING, 2);
3078 
3079   // Build a proper-looking CFG
3080   PhaseCFG cfg(node_arena(), root(), matcher);
3081   if (failing()) {
3082     return;
3083   }
3084   _cfg = &cfg;
3085   {
3086     TracePhase tp(_t_scheduler);
3087     bool success = cfg.do_global_code_motion();
3088     if (!success) {
3089       return;
3090     }
3091 
3092     print_method(PHASE_GLOBAL_CODE_MOTION, 2);
3093     NOT_PRODUCT( verify_graph_edges(); )
3094     cfg.verify();
3095     if (failing()) {
3096       return;
3097     }
3098   }
3099 
3100   PhaseChaitin regalloc(unique(), cfg, matcher, false);
3101   _regalloc = &regalloc;
3102   {
3103     TracePhase tp(_t_registerAllocation);
3104     // Perform register allocation.  After Chaitin, use-def chains are
3105     // no longer accurate (at spill code) and so must be ignored.
3106     // Node->LRG->reg mappings are still accurate.
3107     _regalloc->Register_Allocate();
3108 
3109     // Bail out if the allocator builds too many nodes
3110     if (failing()) {
3111       return;
3112     }
3113 
3114     print_method(PHASE_REGISTER_ALLOCATION, 2);
3115   }
3116 
3117   // Prior to register allocation we kept empty basic blocks in case the
3118   // the allocator needed a place to spill.  After register allocation we
3119   // are not adding any new instructions.  If any basic block is empty, we
3120   // can now safely remove it.
3121   {
3122     TracePhase tp(_t_blockOrdering);
3123     cfg.remove_empty_blocks();
3124     if (do_freq_based_layout()) {
3125       PhaseBlockLayout layout(cfg);
3126     } else {
3127       cfg.set_loop_alignment();
3128     }
3129     cfg.fixup_flow();
3130     cfg.remove_unreachable_blocks();
3131     cfg.verify_dominator_tree();
3132     print_method(PHASE_BLOCK_ORDERING, 3);
3133   }
3134 
3135   // Apply peephole optimizations
3136   if( OptoPeephole ) {
3137     TracePhase tp(_t_peephole);
3138     PhasePeephole peep( _regalloc, cfg);
3139     peep.do_transform();
3140     print_method(PHASE_PEEPHOLE, 3);
3141   }
3142 
3143   // Do late expand if CPU requires this.
3144   if (Matcher::require_postalloc_expand) {
3145     TracePhase tp(_t_postalloc_expand);
3146     cfg.postalloc_expand(_regalloc);
3147     print_method(PHASE_POSTALLOC_EXPAND, 3);
3148   }
3149 
3150 #ifdef ASSERT
3151   {
3152     CompilationMemoryStatistic::do_test_allocations();
3153     if (failing()) return;
3154   }
3155 #endif
3156 
3157   // Convert Nodes to instruction bits in a buffer
3158   {
3159     TracePhase tp(_t_output);
3160     PhaseOutput output;
3161     output.Output();
3162     if (failing())  return;
3163     output.install();
3164     print_method(PHASE_FINAL_CODE, 1); // Compile::_output is not null here
3165   }
3166 
3167   // He's dead, Jim.
3168   _cfg     = (PhaseCFG*)((intptr_t)0xdeadbeef);
3169   _regalloc = (PhaseChaitin*)((intptr_t)0xdeadbeef);
3170 }
3171 
3172 //------------------------------Final_Reshape_Counts---------------------------
3173 // This class defines counters and node lists collected during
3174 // the final graph reshaping.
3175 struct Final_Reshape_Counts : public StackObj {
3176   int  _java_call_count;        // count non-inlined 'java' calls
3177   int  _inner_loop_count;       // count loops which need alignment
3178   VectorSet _visited;           // Visitation flags
3179   Node_List _tests;             // Set of IfNodes & PCTableNodes
3180 
3181   Final_Reshape_Counts() :
3182     _java_call_count(0), _inner_loop_count(0) { }
3183 
3184   void inc_java_call_count() { _java_call_count++; }
3185   void inc_inner_loop_count() { _inner_loop_count++; }
3186 
3187   int  get_java_call_count() const { return _java_call_count; }
3188   int  get_inner_loop_count() const { return _inner_loop_count; }
3189 };
3190 
3191 //------------------------------final_graph_reshaping_impl----------------------
3192 // Implement items 1-5 from final_graph_reshaping below.
3193 void Compile::final_graph_reshaping_impl(Node *n, Final_Reshape_Counts& frc, Unique_Node_List& dead_nodes) {
3194 
3195   if ( n->outcnt() == 0 ) return; // dead node
3196   uint nop = n->Opcode();
3197 
3198   // Check for 2-input instruction with "last use" on right input.
3199   // Swap to left input.  Implements item (2).
3200   if( n->req() == 3 &&          // two-input instruction
3201       n->in(1)->outcnt() > 1 && // left use is NOT a last use
3202       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
3203       n->in(2)->outcnt() == 1 &&// right use IS a last use
3204       !n->in(2)->is_Con() ) {   // right use is not a constant
3205     // Check for commutative opcode
3206     switch( nop ) {
3207     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddHF:  case Op_AddL:
3208     case Op_MaxI:  case Op_MaxL:  case Op_MaxF:  case Op_MaxD:
3209     case Op_MinI:  case Op_MinL:  case Op_MinF:  case Op_MinD:
3210     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulHF:  case Op_MulL:
3211     case Op_AndL:  case Op_XorL:  case Op_OrL:
3212     case Op_AndI:  case Op_XorI:  case Op_OrI: {
3213       // Move "last use" input to left by swapping inputs
3214       n->swap_edges(1, 2);
3215       break;
3216     }
3217     default:
3218       break;
3219     }
3220   }
3221 
3222 #ifdef ASSERT
3223   if( n->is_Mem() ) {
3224     int alias_idx = get_alias_index(n->as_Mem()->adr_type());
3225     assert( n->in(0) != nullptr || alias_idx != Compile::AliasIdxRaw ||
3226             // oop will be recorded in oop map if load crosses safepoint
3227             (n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
3228                               LoadNode::is_immutable_value(n->in(MemNode::Address)))),
3229             "raw memory operations should have control edge");
3230   }
3231   if (n->is_MemBar()) {
3232     MemBarNode* mb = n->as_MemBar();
3233     if (mb->trailing_store() || mb->trailing_load_store()) {
3234       assert(mb->leading_membar()->trailing_membar() == mb, "bad membar pair");
3235       Node* mem = BarrierSet::barrier_set()->barrier_set_c2()->step_over_gc_barrier(mb->in(MemBarNode::Precedent));
3236       assert((mb->trailing_store() && mem->is_Store() && mem->as_Store()->is_release()) ||
3237              (mb->trailing_load_store() && mem->is_LoadStore()), "missing mem op");
3238     } else if (mb->leading()) {
3239       assert(mb->trailing_membar()->leading_membar() == mb, "bad membar pair");
3240     }
3241   }
3242   if (n->is_CallLeafPure()) {
3243     // A pure call whose result projection is unused should have been
3244     // eliminated by CallLeafPureNode::Ideal during IGVN.
3245     assert(n->as_CallLeafPure()->proj_out_or_null(TypeFunc::Parms) != nullptr,
3246            "unused CallLeafPureNode should have been removed before final graph reshaping");
3247   }
3248 #endif
3249   bool gc_handled = BarrierSet::barrier_set()->barrier_set_c2()->final_graph_reshaping(this, n, nop, dead_nodes);
3250   if (!gc_handled) {
3251     final_graph_reshaping_main_switch(n, frc, nop, dead_nodes);
3252   }
3253 
3254   // Collect CFG split points
3255   if (n->is_MultiBranch() && !n->is_RangeCheck()) {
3256     frc._tests.push(n);
3257   }
3258 }
3259 
3260 void Compile::handle_div_mod_op(Node* n, BasicType bt, bool is_unsigned) {
3261   if (!UseDivMod) {
3262     return;
3263   }
3264 
3265   // Check if "a % b" and "a / b" both exist
3266   Node* d = n->find_similar(Op_DivIL(bt, is_unsigned));
3267   if (d == nullptr) {
3268     return;
3269   }
3270 
3271   // Replace them with a fused divmod if supported
3272   if (Matcher::has_match_rule(Op_DivModIL(bt, is_unsigned))) {
3273     DivModNode* divmod = DivModNode::make(n, bt, is_unsigned);
3274     // If the divisor input for a Div (or Mod etc.) is not zero, then the control input of the Div is set to zero.
3275     // It could be that the divisor input is found not zero because its type is narrowed down by a CastII in the
3276     // subgraph for that input. Range check CastIIs are removed during final graph reshape. To preserve the dependency
3277     // carried by a CastII, precedence edges are added to the Div node. We need to transfer the precedence edges to the
3278     // DivMod node so the dependency is not lost.
3279     divmod->add_prec_from(n);
3280     divmod->add_prec_from(d);
3281     d->subsume_by(divmod->div_proj(), this);
3282     n->subsume_by(divmod->mod_proj(), this);
3283   } else {
3284     // Replace "a % b" with "a - ((a / b) * b)"
3285     Node* mult = MulNode::make(d, d->in(2), bt);
3286     Node* sub = SubNode::make(d->in(1), mult, bt);
3287     n->subsume_by(sub, this);
3288   }
3289 }
3290 
3291 void Compile::final_graph_reshaping_main_switch(Node* n, Final_Reshape_Counts& frc, uint nop, Unique_Node_List& dead_nodes) {
3292   switch( nop ) {
3293   case Op_Opaque1:              // Remove Opaque Nodes before matching
3294     n->subsume_by(n->in(1), this);
3295     break;
3296   case Op_CallLeafPure: {
3297     // If the pure call is not supported, then lower to a CallLeaf.
3298     if (!Matcher::match_rule_supported(Op_CallLeafPure)) {
3299       CallNode* call = n->as_Call();
3300       CallNode* new_call = new CallLeafNode(call->tf(), call->entry_point(),
3301                                             call->_name, TypeRawPtr::BOTTOM);
3302       new_call->init_req(TypeFunc::Control, call->in(TypeFunc::Control));
3303       new_call->init_req(TypeFunc::I_O, C->top());
3304       new_call->init_req(TypeFunc::Memory, C->top());
3305       new_call->init_req(TypeFunc::ReturnAdr, C->top());
3306       new_call->init_req(TypeFunc::FramePtr, C->top());
3307       for (unsigned int i = TypeFunc::Parms; i < call->tf()->domain()->cnt(); i++) {
3308         new_call->init_req(i, call->in(i));
3309       }
3310       n->subsume_by(new_call, this);
3311     }
3312     break;
3313   }
3314   case Op_CallStaticJava:
3315   case Op_CallJava:
3316   case Op_CallDynamicJava:
3317     frc.inc_java_call_count(); // Count java call site;
3318   case Op_CallRuntime:
3319   case Op_CallLeaf:
3320   case Op_CallLeafVector:
3321   case Op_CallLeafNoFP: {
3322     assert (n->is_Call(), "");
3323     CallNode *call = n->as_Call();
3324     // See if uncommon argument is shared
3325     if (call->is_CallStaticJava() && call->as_CallStaticJava()->_name) {
3326       Node *n = call->in(TypeFunc::Parms);
3327       int nop = n->Opcode();
3328       // Clone shared simple arguments to uncommon calls, item (1).
3329       if (n->outcnt() > 1 &&
3330           !n->is_Proj() &&
3331           nop != Op_CreateEx &&
3332           nop != Op_CheckCastPP &&
3333           nop != Op_DecodeN &&
3334           nop != Op_DecodeNKlass &&
3335           !n->is_Mem() &&
3336           !n->is_Phi()) {
3337         Node *x = n->clone();
3338         call->set_req(TypeFunc::Parms, x);
3339       }
3340     }
3341     break;
3342   }
3343 
3344   // Mem nodes need explicit cases to satisfy assert(!n->is_Mem()) in default.
3345   case Op_StoreF:
3346   case Op_LoadF:
3347   case Op_StoreD:
3348   case Op_LoadD:
3349   case Op_LoadD_unaligned:
3350   case Op_StoreB:
3351   case Op_StoreC:
3352   case Op_StoreI:
3353   case Op_StoreL:
3354   case Op_CompareAndSwapB:
3355   case Op_CompareAndSwapS:
3356   case Op_CompareAndSwapI:
3357   case Op_CompareAndSwapL:
3358   case Op_CompareAndSwapP:
3359   case Op_CompareAndSwapN:
3360   case Op_WeakCompareAndSwapB:
3361   case Op_WeakCompareAndSwapS:
3362   case Op_WeakCompareAndSwapI:
3363   case Op_WeakCompareAndSwapL:
3364   case Op_WeakCompareAndSwapP:
3365   case Op_WeakCompareAndSwapN:
3366   case Op_CompareAndExchangeB:
3367   case Op_CompareAndExchangeS:
3368   case Op_CompareAndExchangeI:
3369   case Op_CompareAndExchangeL:
3370   case Op_CompareAndExchangeP:
3371   case Op_CompareAndExchangeN:
3372   case Op_GetAndAddS:
3373   case Op_GetAndAddB:
3374   case Op_GetAndAddI:
3375   case Op_GetAndAddL:
3376   case Op_GetAndSetS:
3377   case Op_GetAndSetB:
3378   case Op_GetAndSetI:
3379   case Op_GetAndSetL:
3380   case Op_GetAndSetP:
3381   case Op_GetAndSetN:
3382   case Op_StoreP:
3383   case Op_StoreN:
3384   case Op_StoreNKlass:
3385   case Op_LoadB:
3386   case Op_LoadUB:
3387   case Op_LoadUS:
3388   case Op_LoadI:
3389   case Op_LoadKlass:
3390   case Op_LoadNKlass:
3391   case Op_LoadL:
3392   case Op_LoadL_unaligned:
3393   case Op_LoadP:
3394   case Op_LoadN:
3395   case Op_LoadRange:
3396   case Op_LoadS:
3397   case Op_LoadVectorGather:
3398   case Op_StoreVectorScatter:
3399   case Op_LoadVectorGatherMasked:
3400   case Op_StoreVectorScatterMasked:
3401   case Op_LoadVectorMasked:
3402   case Op_StoreVectorMasked:
3403     break;
3404 
3405   case Op_AddP: {               // Assert sane base pointers
3406     Node *addp = n->in(AddPNode::Address);
3407     assert(n->as_AddP()->address_input_has_same_base(), "Base pointers must match (addp %u)", addp->_idx );
3408 #ifdef _LP64
3409     if (addp->Opcode() == Op_ConP &&
3410         addp == n->in(AddPNode::Base) &&
3411         n->in(AddPNode::Offset)->is_Con()) {
3412       // If the transformation of ConP to ConN+DecodeN is beneficial depends
3413       // on the platform and on the compressed oops mode.
3414       // Use addressing with narrow klass to load with offset on x86.
3415       // Some platforms can use the constant pool to load ConP.
3416       // Do this transformation here since IGVN will convert ConN back to ConP.
3417       const Type* t = addp->bottom_type();
3418       bool is_oop   = t->isa_oopptr() != nullptr;
3419       bool is_klass = t->isa_klassptr() != nullptr;
3420 
3421       if ((is_oop   && UseCompressedOops          && Matcher::const_oop_prefer_decode()  ) ||
3422           (is_klass && Matcher::const_klass_prefer_decode() &&
3423            t->isa_klassptr()->exact_klass()->is_in_encoding_range())) {
3424         Node* nn = nullptr;
3425 
3426         int op = is_oop ? Op_ConN : Op_ConNKlass;
3427 
3428         // Look for existing ConN node of the same exact type.
3429         Node* r  = root();
3430         uint cnt = r->outcnt();
3431         for (uint i = 0; i < cnt; i++) {
3432           Node* m = r->raw_out(i);
3433           if (m!= nullptr && m->Opcode() == op &&
3434               m->bottom_type()->make_ptr() == t) {
3435             nn = m;
3436             break;
3437           }
3438         }
3439         if (nn != nullptr) {
3440           // Decode a narrow oop to match address
3441           // [R12 + narrow_oop_reg<<3 + offset]
3442           if (is_oop) {
3443             nn = new DecodeNNode(nn, t);
3444           } else {
3445             nn = new DecodeNKlassNode(nn, t);
3446           }
3447           // Check for succeeding AddP which uses the same Base.
3448           // Otherwise we will run into the assertion above when visiting that guy.
3449           for (uint i = 0; i < n->outcnt(); ++i) {
3450             Node *out_i = n->raw_out(i);
3451             if (out_i && out_i->is_AddP() && out_i->in(AddPNode::Base) == addp) {
3452               out_i->set_req(AddPNode::Base, nn);
3453 #ifdef ASSERT
3454               for (uint j = 0; j < out_i->outcnt(); ++j) {
3455                 Node *out_j = out_i->raw_out(j);
3456                 assert(out_j == nullptr || !out_j->is_AddP() || out_j->in(AddPNode::Base) != addp,
3457                        "more than 2 AddP nodes in a chain (out_j %u)", out_j->_idx);
3458               }
3459 #endif
3460             }
3461           }
3462           n->set_req(AddPNode::Base, nn);
3463           n->set_req(AddPNode::Address, nn);
3464           if (addp->outcnt() == 0) {
3465             addp->disconnect_inputs(this);
3466           }
3467         }
3468       }
3469     }
3470 #endif
3471     break;
3472   }
3473 
3474   case Op_CastPP: {
3475     // Remove CastPP nodes to gain more freedom during scheduling but
3476     // keep the dependency they encode as control or precedence edges
3477     // (if control is set already) on memory operations. Some CastPP
3478     // nodes don't have a control (don't carry a dependency): skip
3479     // those.
3480     if (n->in(0) != nullptr) {
3481       ResourceMark rm;
3482       Unique_Node_List wq;
3483       wq.push(n);
3484       for (uint next = 0; next < wq.size(); ++next) {
3485         Node *m = wq.at(next);
3486         for (DUIterator_Fast imax, i = m->fast_outs(imax); i < imax; i++) {
3487           Node* use = m->fast_out(i);
3488           if (use->is_Mem() || use->is_EncodeNarrowPtr()) {
3489             use->ensure_control_or_add_prec(n->in(0));
3490           } else {
3491             switch(use->Opcode()) {
3492             case Op_AddP:
3493             case Op_DecodeN:
3494             case Op_DecodeNKlass:
3495             case Op_CheckCastPP:
3496             case Op_CastPP:
3497               wq.push(use);
3498               break;
3499             }
3500           }
3501         }
3502       }
3503     }
3504     const bool is_LP64 = LP64_ONLY(true) NOT_LP64(false);
3505     if (is_LP64 && n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
3506       Node* in1 = n->in(1);
3507       const Type* t = n->bottom_type();
3508       Node* new_in1 = in1->clone();
3509       new_in1->as_DecodeN()->set_type(t);
3510 
3511       if (!Matcher::narrow_oop_use_complex_address()) {
3512         //
3513         // x86, ARM and friends can handle 2 adds in addressing mode
3514         // and Matcher can fold a DecodeN node into address by using
3515         // a narrow oop directly and do implicit null check in address:
3516         //
3517         // [R12 + narrow_oop_reg<<3 + offset]
3518         // NullCheck narrow_oop_reg
3519         //
3520         // On other platforms (Sparc) we have to keep new DecodeN node and
3521         // use it to do implicit null check in address:
3522         //
3523         // decode_not_null narrow_oop_reg, base_reg
3524         // [base_reg + offset]
3525         // NullCheck base_reg
3526         //
3527         // Pin the new DecodeN node to non-null path on these platform (Sparc)
3528         // to keep the information to which null check the new DecodeN node
3529         // corresponds to use it as value in implicit_null_check().
3530         //
3531         new_in1->set_req(0, n->in(0));
3532       }
3533 
3534       n->subsume_by(new_in1, this);
3535       if (in1->outcnt() == 0) {
3536         in1->disconnect_inputs(this);
3537       }
3538     } else {
3539       n->subsume_by(n->in(1), this);
3540       if (n->outcnt() == 0) {
3541         n->disconnect_inputs(this);
3542       }
3543     }
3544     break;
3545   }
3546   case Op_CastII: {
3547     n->as_CastII()->remove_range_check_cast(this);
3548     break;
3549   }
3550 #ifdef _LP64
3551   case Op_CmpP:
3552     // Do this transformation here to preserve CmpPNode::sub() and
3553     // other TypePtr related Ideal optimizations (for example, ptr nullness).
3554     if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
3555       Node* in1 = n->in(1);
3556       Node* in2 = n->in(2);
3557       if (!in1->is_DecodeNarrowPtr()) {
3558         in2 = in1;
3559         in1 = n->in(2);
3560       }
3561       assert(in1->is_DecodeNarrowPtr(), "sanity");
3562 
3563       Node* new_in2 = nullptr;
3564       if (in2->is_DecodeNarrowPtr()) {
3565         assert(in2->Opcode() == in1->Opcode(), "must be same node type");
3566         new_in2 = in2->in(1);
3567       } else if (in2->Opcode() == Op_ConP) {
3568         const Type* t = in2->bottom_type();
3569         if (t == TypePtr::NULL_PTR) {
3570           assert(in1->is_DecodeN(), "compare klass to null?");
3571           // Don't convert CmpP null check into CmpN if compressed
3572           // oops implicit null check is not generated.
3573           // This will allow to generate normal oop implicit null check.
3574           if (Matcher::gen_narrow_oop_implicit_null_checks())
3575             new_in2 = ConNode::make(TypeNarrowOop::NULL_PTR);
3576           //
3577           // This transformation together with CastPP transformation above
3578           // will generated code for implicit null checks for compressed oops.
3579           //
3580           // The original code after Optimize()
3581           //
3582           //    LoadN memory, narrow_oop_reg
3583           //    decode narrow_oop_reg, base_reg
3584           //    CmpP base_reg, nullptr
3585           //    CastPP base_reg // NotNull
3586           //    Load [base_reg + offset], val_reg
3587           //
3588           // after these transformations will be
3589           //
3590           //    LoadN memory, narrow_oop_reg
3591           //    CmpN narrow_oop_reg, nullptr
3592           //    decode_not_null narrow_oop_reg, base_reg
3593           //    Load [base_reg + offset], val_reg
3594           //
3595           // and the uncommon path (== nullptr) will use narrow_oop_reg directly
3596           // since narrow oops can be used in debug info now (see the code in
3597           // final_graph_reshaping_walk()).
3598           //
3599           // At the end the code will be matched to
3600           // on x86:
3601           //
3602           //    Load_narrow_oop memory, narrow_oop_reg
3603           //    Load [R12 + narrow_oop_reg<<3 + offset], val_reg
3604           //    NullCheck narrow_oop_reg
3605           //
3606           // and on sparc:
3607           //
3608           //    Load_narrow_oop memory, narrow_oop_reg
3609           //    decode_not_null narrow_oop_reg, base_reg
3610           //    Load [base_reg + offset], val_reg
3611           //    NullCheck base_reg
3612           //
3613         } else if (t->isa_oopptr()) {
3614           new_in2 = ConNode::make(t->make_narrowoop());
3615         } else if (t->isa_klassptr()) {
3616           ciKlass* klass = t->is_klassptr()->exact_klass();
3617           if (klass->is_in_encoding_range()) {
3618             new_in2 = ConNode::make(t->make_narrowklass());
3619           }
3620         }
3621       }
3622       if (new_in2 != nullptr) {
3623         Node* cmpN = new CmpNNode(in1->in(1), new_in2);
3624         n->subsume_by(cmpN, this);
3625         if (in1->outcnt() == 0) {
3626           in1->disconnect_inputs(this);
3627         }
3628         if (in2->outcnt() == 0) {
3629           in2->disconnect_inputs(this);
3630         }
3631       }
3632     }
3633     break;
3634 
3635   case Op_DecodeN:
3636   case Op_DecodeNKlass:
3637     assert(!n->in(1)->is_EncodeNarrowPtr(), "should be optimized out");
3638     // DecodeN could be pinned when it can't be fold into
3639     // an address expression, see the code for Op_CastPP above.
3640     assert(n->in(0) == nullptr || (UseCompressedOops && !Matcher::narrow_oop_use_complex_address()), "no control");
3641     break;
3642 
3643   case Op_EncodeP:
3644   case Op_EncodePKlass: {
3645     Node* in1 = n->in(1);
3646     if (in1->is_DecodeNarrowPtr()) {
3647       n->subsume_by(in1->in(1), this);
3648     } else if (in1->Opcode() == Op_ConP) {
3649       const Type* t = in1->bottom_type();
3650       if (t == TypePtr::NULL_PTR) {
3651         assert(t->isa_oopptr(), "null klass?");
3652         n->subsume_by(ConNode::make(TypeNarrowOop::NULL_PTR), this);
3653       } else if (t->isa_oopptr()) {
3654         n->subsume_by(ConNode::make(t->make_narrowoop()), this);
3655       } else if (t->isa_klassptr()) {
3656         ciKlass* klass = t->is_klassptr()->exact_klass();
3657         if (klass->is_in_encoding_range()) {
3658           n->subsume_by(ConNode::make(t->make_narrowklass()), this);
3659         } else {
3660           assert(false, "unencodable klass in ConP -> EncodeP");
3661           C->record_failure("unencodable klass in ConP -> EncodeP");
3662         }
3663       }
3664     }
3665     if (in1->outcnt() == 0) {
3666       in1->disconnect_inputs(this);
3667     }
3668     break;
3669   }
3670 
3671   case Op_Proj: {
3672     if (OptimizeStringConcat || IncrementalInline) {
3673       ProjNode* proj = n->as_Proj();
3674       if (proj->_is_io_use) {
3675         assert(proj->_con == TypeFunc::I_O || proj->_con == TypeFunc::Memory, "");
3676         // Separate projections were used for the exception path which
3677         // are normally removed by a late inline.  If it wasn't inlined
3678         // then they will hang around and should just be replaced with
3679         // the original one. Merge them.
3680         Node* non_io_proj = proj->in(0)->as_Multi()->proj_out_or_null(proj->_con, false /*is_io_use*/);
3681         if (non_io_proj  != nullptr) {
3682           proj->subsume_by(non_io_proj , this);
3683         }
3684       }
3685     }
3686     break;
3687   }
3688 
3689   case Op_Phi:
3690     if (n->as_Phi()->bottom_type()->isa_narrowoop() || n->as_Phi()->bottom_type()->isa_narrowklass()) {
3691       // The EncodeP optimization may create Phi with the same edges
3692       // for all paths. It is not handled well by Register Allocator.
3693       Node* unique_in = n->in(1);
3694       assert(unique_in != nullptr, "");
3695       uint cnt = n->req();
3696       for (uint i = 2; i < cnt; i++) {
3697         Node* m = n->in(i);
3698         assert(m != nullptr, "");
3699         if (unique_in != m)
3700           unique_in = nullptr;
3701       }
3702       if (unique_in != nullptr) {
3703         n->subsume_by(unique_in, this);
3704       }
3705     }
3706     break;
3707 
3708 #endif
3709 
3710   case Op_ModI:
3711     handle_div_mod_op(n, T_INT, false);
3712     break;
3713 
3714   case Op_ModL:
3715     handle_div_mod_op(n, T_LONG, false);
3716     break;
3717 
3718   case Op_UModI:
3719     handle_div_mod_op(n, T_INT, true);
3720     break;
3721 
3722   case Op_UModL:
3723     handle_div_mod_op(n, T_LONG, true);
3724     break;
3725 
3726   case Op_LoadVector:
3727   case Op_StoreVector:
3728 #ifdef ASSERT
3729     // Add VerifyVectorAlignment node between adr and load / store.
3730     if (VerifyAlignVector && Matcher::has_match_rule(Op_VerifyVectorAlignment)) {
3731       bool must_verify_alignment = n->is_LoadVector() ? n->as_LoadVector()->must_verify_alignment() :
3732                                                         n->as_StoreVector()->must_verify_alignment();
3733       if (must_verify_alignment) {
3734         jlong vector_width = n->is_LoadVector() ? n->as_LoadVector()->memory_size() :
3735                                                   n->as_StoreVector()->memory_size();
3736         // The memory access should be aligned to the vector width in bytes.
3737         // However, the underlying array is possibly less well aligned, but at least
3738         // to ObjectAlignmentInBytes. Hence, even if multiple arrays are accessed in
3739         // a loop we can expect at least the following alignment:
3740         jlong guaranteed_alignment = MIN2(vector_width, (jlong)ObjectAlignmentInBytes);
3741         assert(2 <= guaranteed_alignment && guaranteed_alignment <= 64, "alignment must be in range");
3742         assert(is_power_of_2(guaranteed_alignment), "alignment must be power of 2");
3743         // Create mask from alignment. e.g. 0b1000 -> 0b0111
3744         jlong mask = guaranteed_alignment - 1;
3745         Node* mask_con = ConLNode::make(mask);
3746         VerifyVectorAlignmentNode* va = new VerifyVectorAlignmentNode(n->in(MemNode::Address), mask_con);
3747         n->set_req(MemNode::Address, va);
3748       }
3749     }
3750 #endif
3751     break;
3752 
3753   case Op_PackB:
3754   case Op_PackS:
3755   case Op_PackI:
3756   case Op_PackF:
3757   case Op_PackL:
3758   case Op_PackD:
3759     if (n->req()-1 > 2) {
3760       // Replace many operand PackNodes with a binary tree for matching
3761       PackNode* p = (PackNode*) n;
3762       Node* btp = p->binary_tree_pack(1, n->req());
3763       n->subsume_by(btp, this);
3764     }
3765     break;
3766   case Op_Loop:
3767     // When StressCountedLoop is enabled, this loop may intentionally avoid a counted loop conversion.
3768     // This is expected behavior for the stress mode, which exercises alternative compilation paths.
3769     if (!StressCountedLoop) {
3770       assert(!n->as_Loop()->is_loop_nest_inner_loop() || _loop_opts_cnt == 0, "should have been turned into a counted loop");
3771     }
3772   case Op_CountedLoop:
3773   case Op_LongCountedLoop:
3774   case Op_OuterStripMinedLoop:
3775     if (n->as_Loop()->is_inner_loop()) {
3776       frc.inc_inner_loop_count();
3777     }
3778     n->as_Loop()->verify_strip_mined(0);
3779     break;
3780   case Op_LShiftI:
3781   case Op_RShiftI:
3782   case Op_URShiftI:
3783   case Op_LShiftL:
3784   case Op_RShiftL:
3785   case Op_URShiftL:
3786     if (Matcher::need_masked_shift_count) {
3787       // The cpu's shift instructions don't restrict the count to the
3788       // lower 5/6 bits. We need to do the masking ourselves.
3789       Node* in2 = n->in(2);
3790       juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
3791       const TypeInt* t = in2->find_int_type();
3792       if (t != nullptr && t->is_con()) {
3793         juint shift = t->get_con();
3794         if (shift > mask) { // Unsigned cmp
3795           n->set_req(2, ConNode::make(TypeInt::make(shift & mask)));
3796         }
3797       } else {
3798         if (t == nullptr || t->_lo < 0 || t->_hi > (int)mask) {
3799           Node* shift = new AndINode(in2, ConNode::make(TypeInt::make(mask)));
3800           n->set_req(2, shift);
3801         }
3802       }
3803       if (in2->outcnt() == 0) { // Remove dead node
3804         in2->disconnect_inputs(this);
3805       }
3806     }
3807     break;
3808   case Op_MemBarStoreStore:
3809   case Op_MemBarRelease:
3810     // Break the link with AllocateNode: it is no longer useful and
3811     // confuses register allocation.
3812     if (n->req() > MemBarNode::Precedent) {
3813       n->set_req(MemBarNode::Precedent, top());
3814     }
3815     break;
3816   case Op_MemBarAcquire: {
3817     if (n->as_MemBar()->trailing_load() && n->req() > MemBarNode::Precedent) {
3818       // At parse time, the trailing MemBarAcquire for a volatile load
3819       // is created with an edge to the load. After optimizations,
3820       // that input may be a chain of Phis. If those phis have no
3821       // other use, then the MemBarAcquire keeps them alive and
3822       // register allocation can be confused.
3823       dead_nodes.push(n->in(MemBarNode::Precedent));
3824       n->set_req(MemBarNode::Precedent, top());
3825     }
3826     break;
3827   }
3828   case Op_RangeCheck: {
3829     RangeCheckNode* rc = n->as_RangeCheck();
3830     Node* iff = new IfNode(rc->in(0), rc->in(1), rc->_prob, rc->_fcnt);
3831     n->subsume_by(iff, this);
3832     frc._tests.push(iff);
3833     break;
3834   }
3835   case Op_ConvI2L: {
3836     if (!Matcher::convi2l_type_required) {
3837       // Code generation on some platforms doesn't need accurate
3838       // ConvI2L types. Widening the type can help remove redundant
3839       // address computations.
3840       n->as_Type()->set_type(TypeLong::INT);
3841       ResourceMark rm;
3842       Unique_Node_List wq;
3843       wq.push(n);
3844       for (uint next = 0; next < wq.size(); next++) {
3845         Node *m = wq.at(next);
3846 
3847         for(;;) {
3848           // Loop over all nodes with identical inputs edges as m
3849           Node* k = m->find_similar(m->Opcode());
3850           if (k == nullptr) {
3851             break;
3852           }
3853           // Push their uses so we get a chance to remove node made
3854           // redundant
3855           for (DUIterator_Fast imax, i = k->fast_outs(imax); i < imax; i++) {
3856             Node* u = k->fast_out(i);
3857             if (u->Opcode() == Op_LShiftL ||
3858                 u->Opcode() == Op_AddL ||
3859                 u->Opcode() == Op_SubL ||
3860                 u->Opcode() == Op_AddP) {
3861               wq.push(u);
3862             }
3863           }
3864           // Replace all nodes with identical edges as m with m
3865           k->subsume_by(m, this);
3866         }
3867       }
3868     }
3869     break;
3870   }
3871   case Op_CmpUL: {
3872     if (!Matcher::has_match_rule(Op_CmpUL)) {
3873       // No support for unsigned long comparisons
3874       ConINode* sign_pos = new ConINode(TypeInt::make(BitsPerLong - 1));
3875       Node* sign_bit_mask = new RShiftLNode(n->in(1), sign_pos);
3876       Node* orl = new OrLNode(n->in(1), sign_bit_mask);
3877       ConLNode* remove_sign_mask = new ConLNode(TypeLong::make(max_jlong));
3878       Node* andl = new AndLNode(orl, remove_sign_mask);
3879       Node* cmp = new CmpLNode(andl, n->in(2));
3880       n->subsume_by(cmp, this);
3881     }
3882     break;
3883   }
3884 #ifdef ASSERT
3885   case Op_ConNKlass: {
3886     const TypePtr* tp = n->as_Type()->type()->make_ptr();
3887     ciKlass* klass = tp->is_klassptr()->exact_klass();
3888     assert(klass->is_in_encoding_range(), "klass cannot be compressed");
3889     break;
3890   }
3891 #endif
3892   default:
3893     assert(!n->is_Call(), "");
3894     assert(!n->is_Mem(), "");
3895     assert(nop != Op_ProfileBoolean, "should be eliminated during IGVN");
3896     break;
3897   }
3898 }
3899 
3900 //------------------------------final_graph_reshaping_walk---------------------
3901 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
3902 // requires that the walk visits a node's inputs before visiting the node.
3903 void Compile::final_graph_reshaping_walk(Node_Stack& nstack, Node* root, Final_Reshape_Counts& frc, Unique_Node_List& dead_nodes) {
3904   Unique_Node_List sfpt;
3905 
3906   frc._visited.set(root->_idx); // first, mark node as visited
3907   uint cnt = root->req();
3908   Node *n = root;
3909   uint  i = 0;
3910   while (true) {
3911     if (i < cnt) {
3912       // Place all non-visited non-null inputs onto stack
3913       Node* m = n->in(i);
3914       ++i;
3915       if (m != nullptr && !frc._visited.test_set(m->_idx)) {
3916         if (m->is_SafePoint() && m->as_SafePoint()->jvms() != nullptr) {
3917           // compute worst case interpreter size in case of a deoptimization
3918           update_interpreter_frame_size(m->as_SafePoint()->jvms()->interpreter_frame_size());
3919 
3920           sfpt.push(m);
3921         }
3922         cnt = m->req();
3923         nstack.push(n, i); // put on stack parent and next input's index
3924         n = m;
3925         i = 0;
3926       }
3927     } else {
3928       // Now do post-visit work
3929       final_graph_reshaping_impl(n, frc, dead_nodes);
3930       if (nstack.is_empty())
3931         break;             // finished
3932       n = nstack.node();   // Get node from stack
3933       cnt = n->req();
3934       i = nstack.index();
3935       nstack.pop();        // Shift to the next node on stack
3936     }
3937   }
3938 
3939   expand_reachability_edges(sfpt);
3940 
3941   // Skip next transformation if compressed oops are not used.
3942   if (UseCompressedOops && !Matcher::gen_narrow_oop_implicit_null_checks())
3943     return;
3944 
3945   // Go over ReachabilityFence nodes to skip DecodeN nodes for referents.
3946   // The sole purpose of RF node is to keep the referent oop alive and
3947   // decoding the oop for that is not needed.
3948   for (int i = 0; i < C->reachability_fences_count(); i++) {
3949     ReachabilityFenceNode* rf = C->reachability_fence(i);
3950     DecodeNNode* dn = rf->in(1)->isa_DecodeN();
3951     if (dn != nullptr) {
3952       if (!dn->has_non_debug_uses() || Matcher::narrow_oop_use_complex_address()) {
3953         rf->set_req(1, dn->in(1));
3954         if (dn->outcnt() == 0) {
3955           dn->disconnect_inputs(this);
3956         }
3957       }
3958     }
3959   }
3960 
3961   // Go over safepoints nodes to skip DecodeN/DecodeNKlass nodes for debug edges.
3962   // It could be done for an uncommon traps or any safepoints/calls
3963   // if the DecodeN/DecodeNKlass node is referenced only in a debug info.
3964   while (sfpt.size() > 0) {
3965     n = sfpt.pop();
3966     JVMState *jvms = n->as_SafePoint()->jvms();
3967     assert(jvms != nullptr, "sanity");
3968     int start = jvms->debug_start();
3969     int end   = n->req();
3970     bool is_uncommon = (n->is_CallStaticJava() &&
3971                         n->as_CallStaticJava()->uncommon_trap_request() != 0);
3972     for (int j = start; j < end; j++) {
3973       Node* in = n->in(j);
3974       if (in->is_DecodeNarrowPtr() && (is_uncommon || !in->has_non_debug_uses())) {
3975         n->set_req(j, in->in(1));
3976         if (in->outcnt() == 0) {
3977           in->disconnect_inputs(this);
3978         }
3979       }
3980     }
3981   }
3982 }
3983 
3984 //------------------------------final_graph_reshaping--------------------------
3985 // Final Graph Reshaping.
3986 //
3987 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
3988 //     and not commoned up and forced early.  Must come after regular
3989 //     optimizations to avoid GVN undoing the cloning.  Clone constant
3990 //     inputs to Loop Phis; these will be split by the allocator anyways.
3991 //     Remove Opaque nodes.
3992 // (2) Move last-uses by commutative operations to the left input to encourage
3993 //     Intel update-in-place two-address operations and better register usage
3994 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
3995 //     calls canonicalizing them back.
3996 // (3) Detect infinite loops; blobs of code reachable from above but not
3997 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
3998 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
3999 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
4000 //     Detection is by looking for IfNodes where only 1 projection is
4001 //     reachable from below or CatchNodes missing some targets.
4002 // (4) Assert for insane oop offsets in debug mode.
4003 
4004 bool Compile::final_graph_reshaping() {
4005   // an infinite loop may have been eliminated by the optimizer,
4006   // in which case the graph will be empty.
4007   if (root()->req() == 1) {
4008     // Do not compile method that is only a trivial infinite loop,
4009     // since the content of the loop may have been eliminated.
4010     record_method_not_compilable("trivial infinite loop");
4011     return true;
4012   }
4013 
4014   // Expensive nodes have their control input set to prevent the GVN
4015   // from freely commoning them. There's no GVN beyond this point so
4016   // no need to keep the control input. We want the expensive nodes to
4017   // be freely moved to the least frequent code path by gcm.
4018   assert(OptimizeExpensiveOps || expensive_count() == 0, "optimization off but list non empty?");
4019   for (int i = 0; i < expensive_count(); i++) {
4020     _expensive_nodes.at(i)->set_req(0, nullptr);
4021   }
4022 
4023   Final_Reshape_Counts frc;
4024 
4025   // Visit everybody reachable!
4026   // Allocate stack of size C->live_nodes()/2 to avoid frequent realloc
4027   Node_Stack nstack(live_nodes() >> 1);
4028   Unique_Node_List dead_nodes;
4029   final_graph_reshaping_walk(nstack, root(), frc, dead_nodes);
4030 
4031   // Check for unreachable (from below) code (i.e., infinite loops).
4032   for( uint i = 0; i < frc._tests.size(); i++ ) {
4033     MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
4034     // Get number of CFG targets.
4035     // Note that PCTables include exception targets after calls.
4036     uint required_outcnt = n->required_outcnt();
4037     if (n->outcnt() != required_outcnt) {
4038       // Check for a few special cases.  Rethrow Nodes never take the
4039       // 'fall-thru' path, so expected kids is 1 less.
4040       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
4041         if (n->in(0)->in(0)->is_Call()) {
4042           CallNode* call = n->in(0)->in(0)->as_Call();
4043           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
4044             required_outcnt--;      // Rethrow always has 1 less kid
4045           } else if (call->req() > TypeFunc::Parms &&
4046                      call->is_CallDynamicJava()) {
4047             // Check for null receiver. In such case, the optimizer has
4048             // detected that the virtual call will always result in a null
4049             // pointer exception. The fall-through projection of this CatchNode
4050             // will not be populated.
4051             Node* arg0 = call->in(TypeFunc::Parms);
4052             if (arg0->is_Type() &&
4053                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
4054               required_outcnt--;
4055             }
4056           } else if (call->entry_point() == OptoRuntime::new_array_Java() ||
4057                      call->entry_point() == OptoRuntime::new_array_nozero_Java()) {
4058             // Check for illegal array length. In such case, the optimizer has
4059             // detected that the allocation attempt will always result in an
4060             // exception. There is no fall-through projection of this CatchNode .
4061             assert(call->is_CallStaticJava(), "static call expected");
4062             assert(call->req() == call->jvms()->endoff() + 1, "missing extra input");
4063             uint valid_length_test_input = call->req() - 1;
4064             Node* valid_length_test = call->in(valid_length_test_input);
4065             call->del_req(valid_length_test_input);
4066             if (valid_length_test->find_int_con(1) == 0) {
4067               required_outcnt--;
4068             }
4069             dead_nodes.push(valid_length_test);
4070             assert(n->outcnt() == required_outcnt, "malformed control flow");
4071             continue;
4072           }
4073         }
4074       }
4075 
4076       // Recheck with a better notion of 'required_outcnt'
4077       if (n->outcnt() != required_outcnt) {
4078         record_method_not_compilable("malformed control flow");
4079         return true;            // Not all targets reachable!
4080       }
4081     } else if (n->is_PCTable() && n->in(0) && n->in(0)->in(0) && n->in(0)->in(0)->is_Call()) {
4082       CallNode* call = n->in(0)->in(0)->as_Call();
4083       if (call->entry_point() == OptoRuntime::new_array_Java() ||
4084           call->entry_point() == OptoRuntime::new_array_nozero_Java()) {
4085         assert(call->is_CallStaticJava(), "static call expected");
4086         assert(call->req() == call->jvms()->endoff() + 1, "missing extra input");
4087         uint valid_length_test_input = call->req() - 1;
4088         dead_nodes.push(call->in(valid_length_test_input));
4089         call->del_req(valid_length_test_input); // valid length test useless now
4090       }
4091     }
4092     // Check that I actually visited all kids.  Unreached kids
4093     // must be infinite loops.
4094     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
4095       if (!frc._visited.test(n->fast_out(j)->_idx)) {
4096         record_method_not_compilable("infinite loop");
4097         return true;            // Found unvisited kid; must be unreach
4098       }
4099 
4100     // Here so verification code in final_graph_reshaping_walk()
4101     // always see an OuterStripMinedLoopEnd
4102     if (n->is_OuterStripMinedLoopEnd() || n->is_LongCountedLoopEnd()) {
4103       IfNode* init_iff = n->as_If();
4104       Node* iff = new IfNode(init_iff->in(0), init_iff->in(1), init_iff->_prob, init_iff->_fcnt);
4105       n->subsume_by(iff, this);
4106     }
4107   }
4108 
4109   while (dead_nodes.size() > 0) {
4110     Node* m = dead_nodes.pop();
4111     if (m->outcnt() == 0 && m != top()) {
4112       for (uint j = 0; j < m->req(); j++) {
4113         Node* in = m->in(j);
4114         if (in != nullptr) {
4115           dead_nodes.push(in);
4116         }
4117       }
4118       m->disconnect_inputs(this);
4119     }
4120   }
4121 
4122   set_java_calls(frc.get_java_call_count());
4123   set_inner_loops(frc.get_inner_loop_count());
4124 
4125   // No infinite loops, no reason to bail out.
4126   return false;
4127 }
4128 
4129 //-----------------------------too_many_traps----------------------------------
4130 // Report if there are too many traps at the current method and bci.
4131 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
4132 bool Compile::too_many_traps(ciMethod* method,
4133                              int bci,
4134                              Deoptimization::DeoptReason reason) {
4135   ciMethodData* md = method->method_data();
4136   if (md->is_empty()) {
4137     // Assume the trap has not occurred, or that it occurred only
4138     // because of a transient condition during start-up in the interpreter.
4139     return false;
4140   }
4141   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : nullptr;
4142   if (md->has_trap_at(bci, m, reason) != 0) {
4143     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
4144     // Also, if there are multiple reasons, or if there is no per-BCI record,
4145     // assume the worst.
4146     if (log())
4147       log()->elem("observe trap='%s' count='%d'",
4148                   Deoptimization::trap_reason_name(reason),
4149                   md->trap_count(reason));
4150     return true;
4151   } else {
4152     // Ignore method/bci and see if there have been too many globally.
4153     return too_many_traps(reason, md);
4154   }
4155 }
4156 
4157 // Less-accurate variant which does not require a method and bci.
4158 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
4159                              ciMethodData* logmd) {
4160   if (trap_count(reason) >= Deoptimization::per_method_trap_limit(reason)) {
4161     // Too many traps globally.
4162     // Note that we use cumulative trap_count, not just md->trap_count.
4163     if (log()) {
4164       int mcount = (logmd == nullptr)? -1: (int)logmd->trap_count(reason);
4165       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
4166                   Deoptimization::trap_reason_name(reason),
4167                   mcount, trap_count(reason));
4168     }
4169     return true;
4170   } else {
4171     // The coast is clear.
4172     return false;
4173   }
4174 }
4175 
4176 //--------------------------too_many_recompiles--------------------------------
4177 // Report if there are too many recompiles at the current method and bci.
4178 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
4179 // Is not eager to return true, since this will cause the compiler to use
4180 // Action_none for a trap point, to avoid too many recompilations.
4181 bool Compile::too_many_recompiles(ciMethod* method,
4182                                   int bci,
4183                                   Deoptimization::DeoptReason reason) {
4184   ciMethodData* md = method->method_data();
4185   if (md->is_empty()) {
4186     // Assume the trap has not occurred, or that it occurred only
4187     // because of a transient condition during start-up in the interpreter.
4188     return false;
4189   }
4190   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
4191   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
4192   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
4193   Deoptimization::DeoptReason per_bc_reason
4194     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
4195   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : nullptr;
4196   if ((per_bc_reason == Deoptimization::Reason_none
4197        || md->has_trap_at(bci, m, reason) != 0)
4198       // The trap frequency measure we care about is the recompile count:
4199       && md->trap_recompiled_at(bci, m)
4200       && md->overflow_recompile_count() >= bc_cutoff) {
4201     // Do not emit a trap here if it has already caused recompilations.
4202     // Also, if there are multiple reasons, or if there is no per-BCI record,
4203     // assume the worst.
4204     if (log())
4205       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
4206                   Deoptimization::trap_reason_name(reason),
4207                   md->trap_count(reason),
4208                   md->overflow_recompile_count());
4209     return true;
4210   } else if (trap_count(reason) != 0
4211              && decompile_count() >= m_cutoff) {
4212     // Too many recompiles globally, and we have seen this sort of trap.
4213     // Use cumulative decompile_count, not just md->decompile_count.
4214     if (log())
4215       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
4216                   Deoptimization::trap_reason_name(reason),
4217                   md->trap_count(reason), trap_count(reason),
4218                   md->decompile_count(), decompile_count());
4219     return true;
4220   } else {
4221     // The coast is clear.
4222     return false;
4223   }
4224 }
4225 
4226 // Compute when not to trap. Used by matching trap based nodes and
4227 // NullCheck optimization.
4228 void Compile::set_allowed_deopt_reasons() {
4229   _allowed_reasons = 0;
4230   if (is_method_compilation()) {
4231     for (int rs = (int)Deoptimization::Reason_none+1; rs < Compile::trapHistLength; rs++) {
4232       assert(rs < BitsPerInt, "recode bit map");
4233       if (!too_many_traps((Deoptimization::DeoptReason) rs)) {
4234         _allowed_reasons |= nth_bit(rs);
4235       }
4236     }
4237   }
4238 }
4239 
4240 bool Compile::needs_clinit_barrier(ciMethod* method, ciMethod* accessing_method) {
4241   return method->is_static() && needs_clinit_barrier(method->holder(), accessing_method);
4242 }
4243 
4244 bool Compile::needs_clinit_barrier(ciField* field, ciMethod* accessing_method) {
4245   return field->is_static() && needs_clinit_barrier(field->holder(), accessing_method);
4246 }
4247 
4248 bool Compile::needs_clinit_barrier(ciInstanceKlass* holder, ciMethod* accessing_method) {
4249   if (holder->is_initialized()) {
4250     return false;
4251   }
4252   if (holder->is_being_initialized()) {
4253     if (accessing_method->holder() == holder) {
4254       // Access inside a class. The barrier can be elided when access happens in <clinit>,
4255       // <init>, or a static method. In all those cases, there was an initialization
4256       // barrier on the holder klass passed.
4257       if (accessing_method->is_static_initializer() ||
4258           accessing_method->is_object_initializer() ||
4259           accessing_method->is_static()) {
4260         return false;
4261       }
4262     } else if (accessing_method->holder()->is_subclass_of(holder)) {
4263       // Access from a subclass. The barrier can be elided only when access happens in <clinit>.
4264       // In case of <init> or a static method, the barrier is on the subclass is not enough:
4265       // child class can become fully initialized while its parent class is still being initialized.
4266       if (accessing_method->is_static_initializer()) {
4267         return false;
4268       }
4269     }
4270     ciMethod* root = method(); // the root method of compilation
4271     if (root != accessing_method) {
4272       return needs_clinit_barrier(holder, root); // check access in the context of compilation root
4273     }
4274   }
4275   return true;
4276 }
4277 
4278 #ifndef PRODUCT
4279 //------------------------------verify_bidirectional_edges---------------------
4280 // For each input edge to a node (ie - for each Use-Def edge), verify that
4281 // there is a corresponding Def-Use edge.
4282 void Compile::verify_bidirectional_edges(Unique_Node_List& visited, const Unique_Node_List* root_and_safepoints) const {
4283   // Allocate stack of size C->live_nodes()/16 to avoid frequent realloc
4284   uint stack_size = live_nodes() >> 4;
4285   Node_List nstack(MAX2(stack_size, (uint) OptoNodeListSize));
4286   if (root_and_safepoints != nullptr) {
4287     assert(root_and_safepoints->member(_root), "root is not in root_and_safepoints");
4288     for (uint i = 0, limit = root_and_safepoints->size(); i < limit; i++) {
4289       Node* root_or_safepoint = root_and_safepoints->at(i);
4290       // If the node is a safepoint, let's check if it still has a control input
4291       // Lack of control input signifies that this node was killed by CCP or
4292       // recursively by remove_globally_dead_node and it shouldn't be a starting
4293       // point.
4294       if (!root_or_safepoint->is_SafePoint() || root_or_safepoint->in(0) != nullptr) {
4295         nstack.push(root_or_safepoint);
4296       }
4297     }
4298   } else {
4299     nstack.push(_root);
4300   }
4301 
4302   while (nstack.size() > 0) {
4303     Node* n = nstack.pop();
4304     if (visited.member(n)) {
4305       continue;
4306     }
4307     visited.push(n);
4308 
4309     // Walk over all input edges, checking for correspondence
4310     uint length = n->len();
4311     for (uint i = 0; i < length; i++) {
4312       Node* in = n->in(i);
4313       if (in != nullptr && !visited.member(in)) {
4314         nstack.push(in); // Put it on stack
4315       }
4316       if (in != nullptr && !in->is_top()) {
4317         // Count instances of `next`
4318         int cnt = 0;
4319         for (uint idx = 0; idx < in->_outcnt; idx++) {
4320           if (in->_out[idx] == n) {
4321             cnt++;
4322           }
4323         }
4324         assert(cnt > 0, "Failed to find Def-Use edge.");
4325         // Check for duplicate edges
4326         // walk the input array downcounting the input edges to n
4327         for (uint j = 0; j < length; j++) {
4328           if (n->in(j) == in) {
4329             cnt--;
4330           }
4331         }
4332         assert(cnt == 0, "Mismatched edge count.");
4333       } else if (in == nullptr) {
4334         assert(i == 0 || i >= n->req() ||
4335                n->is_Region() || n->is_Phi() || n->is_ArrayCopy() ||
4336                (n->is_Unlock() && i == (n->req() - 1)) ||
4337                (n->is_MemBar() && i == 5), // the precedence edge to a membar can be removed during macro node expansion
4338               "only region, phi, arraycopy, unlock or membar nodes have null data edges");
4339       } else {
4340         assert(in->is_top(), "sanity");
4341         // Nothing to check.
4342       }
4343     }
4344   }
4345 }
4346 
4347 //------------------------------verify_graph_edges---------------------------
4348 // Walk the Graph and verify that there is a one-to-one correspondence
4349 // between Use-Def edges and Def-Use edges in the graph.
4350 void Compile::verify_graph_edges(bool no_dead_code, const Unique_Node_List* root_and_safepoints) const {
4351   if (VerifyGraphEdges) {
4352     Unique_Node_List visited;
4353 
4354     // Call graph walk to check edges
4355     verify_bidirectional_edges(visited, root_and_safepoints);
4356     if (no_dead_code) {
4357       // Now make sure that no visited node is used by an unvisited node.
4358       bool dead_nodes = false;
4359       Unique_Node_List checked;
4360       while (visited.size() > 0) {
4361         Node* n = visited.pop();
4362         checked.push(n);
4363         for (uint i = 0; i < n->outcnt(); i++) {
4364           Node* use = n->raw_out(i);
4365           if (checked.member(use))  continue;  // already checked
4366           if (visited.member(use))  continue;  // already in the graph
4367           if (use->is_Con())        continue;  // a dead ConNode is OK
4368           // At this point, we have found a dead node which is DU-reachable.
4369           if (!dead_nodes) {
4370             tty->print_cr("*** Dead nodes reachable via DU edges:");
4371             dead_nodes = true;
4372           }
4373           use->dump(2);
4374           tty->print_cr("---");
4375           checked.push(use);  // No repeats; pretend it is now checked.
4376         }
4377       }
4378       assert(!dead_nodes, "using nodes must be reachable from root");
4379     }
4380   }
4381 }
4382 #endif
4383 
4384 // The Compile object keeps track of failure reasons separately from the ciEnv.
4385 // This is required because there is not quite a 1-1 relation between the
4386 // ciEnv and its compilation task and the Compile object.  Note that one
4387 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
4388 // to backtrack and retry without subsuming loads.  Other than this backtracking
4389 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
4390 // by the logic in C2Compiler.
4391 void Compile::record_failure(const char* reason DEBUG_ONLY(COMMA bool allow_multiple_failures)) {
4392   if (log() != nullptr) {
4393     log()->elem("failure reason='%s' phase='compile'", reason);
4394   }
4395   if (_failure_reason.get() == nullptr) {
4396     // Record the first failure reason.
4397     _failure_reason.set(reason);
4398     if (CaptureBailoutInformation) {
4399       _first_failure_details = new CompilationFailureInfo(reason);
4400     }
4401   } else {
4402     assert(!StressBailout || allow_multiple_failures, "should have handled previous failure.");
4403   }
4404 
4405   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
4406     C->print_method(PHASE_FAILURE, 1);
4407   }
4408   _root = nullptr;  // flush the graph, too
4409 }
4410 
4411 Compile::TracePhase::TracePhase(const char* name, PhaseTraceId id)
4412   : TraceTime(name, &Phase::timers[id], CITime, CITimeVerbose),
4413     _compile(Compile::current()),
4414     _log(nullptr),
4415     _dolog(CITimeVerbose)
4416 {
4417   assert(_compile != nullptr, "sanity check");
4418   assert(id != PhaseTraceId::_t_none, "Don't use none");
4419   if (_dolog) {
4420     _log = _compile->log();
4421   }
4422   if (_log != nullptr) {
4423     _log->begin_head("phase name='%s' nodes='%d' live='%d'", phase_name(), _compile->unique(), _compile->live_nodes());
4424     _log->stamp();
4425     _log->end_head();
4426   }
4427 
4428   // Inform memory statistic, if enabled
4429   if (CompilationMemoryStatistic::enabled()) {
4430     CompilationMemoryStatistic::on_phase_start((int)id, name);
4431   }
4432 }
4433 
4434 Compile::TracePhase::TracePhase(PhaseTraceId id)
4435   : TracePhase(Phase::get_phase_trace_id_text(id), id) {}
4436 
4437 Compile::TracePhase::~TracePhase() {
4438 
4439   // Inform memory statistic, if enabled
4440   if (CompilationMemoryStatistic::enabled()) {
4441     CompilationMemoryStatistic::on_phase_end();
4442   }
4443 
4444   if (_compile->failing_internal()) {
4445     if (_log != nullptr) {
4446       _log->done("phase");
4447     }
4448     return; // timing code, not stressing bailouts.
4449   }
4450 #ifdef ASSERT
4451   if (PrintIdealNodeCount) {
4452     tty->print_cr("phase name='%s' nodes='%d' live='%d' live_graph_walk='%d'",
4453                   phase_name(), _compile->unique(), _compile->live_nodes(), _compile->count_live_nodes_by_graph_walk());
4454   }
4455 
4456   if (VerifyIdealNodeCount) {
4457     _compile->print_missing_nodes();
4458   }
4459 #endif
4460 
4461   if (_log != nullptr) {
4462     _log->done("phase name='%s' nodes='%d' live='%d'", phase_name(), _compile->unique(), _compile->live_nodes());
4463   }
4464 }
4465 
4466 //----------------------------static_subtype_check-----------------------------
4467 // Shortcut important common cases when superklass is exact:
4468 // (0) superklass is java.lang.Object (can occur in reflective code)
4469 // (1) subklass is already limited to a subtype of superklass => always ok
4470 // (2) subklass does not overlap with superklass => always fail
4471 // (3) superklass has NO subtypes and we can check with a simple compare.
4472 Compile::SubTypeCheckResult Compile::static_subtype_check(const TypeKlassPtr* superk, const TypeKlassPtr* subk, bool skip) {
4473   if (skip) {
4474     return SSC_full_test;       // Let caller generate the general case.
4475   }
4476 
4477   if (subk->is_java_subtype_of(superk)) {
4478     return SSC_always_true; // (0) and (1)  this test cannot fail
4479   }
4480 
4481   if (!subk->maybe_java_subtype_of(superk)) {
4482     return SSC_always_false; // (2) true path dead; no dynamic test needed
4483   }
4484 
4485   const Type* superelem = superk;
4486   if (superk->isa_aryklassptr()) {
4487     int ignored;
4488     superelem = superk->is_aryklassptr()->base_element_type(ignored);
4489   }
4490 
4491   if (superelem->isa_instklassptr()) {
4492     ciInstanceKlass* ik = superelem->is_instklassptr()->instance_klass();
4493     if (!ik->has_subklass()) {
4494       if (!ik->is_final()) {
4495         // Add a dependency if there is a chance of a later subclass.
4496         dependencies()->assert_leaf_type(ik);
4497       }
4498       if (!superk->maybe_java_subtype_of(subk)) {
4499         return SSC_always_false;
4500       }
4501       return SSC_easy_test;     // (3) caller can do a simple ptr comparison
4502     }
4503   } else {
4504     // A primitive array type has no subtypes.
4505     return SSC_easy_test;       // (3) caller can do a simple ptr comparison
4506   }
4507 
4508   return SSC_full_test;
4509 }
4510 
4511 Node* Compile::conv_I2X_index(PhaseGVN* phase, Node* idx, const TypeInt* sizetype, Node* ctrl) {
4512 #ifdef _LP64
4513   // The scaled index operand to AddP must be a clean 64-bit value.
4514   // Java allows a 32-bit int to be incremented to a negative
4515   // value, which appears in a 64-bit register as a large
4516   // positive number.  Using that large positive number as an
4517   // operand in pointer arithmetic has bad consequences.
4518   // On the other hand, 32-bit overflow is rare, and the possibility
4519   // can often be excluded, if we annotate the ConvI2L node with
4520   // a type assertion that its value is known to be a small positive
4521   // number.  (The prior range check has ensured this.)
4522   // This assertion is used by ConvI2LNode::Ideal.
4523   int index_max = max_jint - 1;  // array size is max_jint, index is one less
4524   if (sizetype != nullptr && sizetype->_hi > 0) {
4525     index_max = sizetype->_hi - 1;
4526   }
4527   const TypeInt* iidxtype = TypeInt::make(0, index_max, Type::WidenMax);
4528   idx = constrained_convI2L(phase, idx, iidxtype, ctrl);
4529 #endif
4530   return idx;
4531 }
4532 
4533 // Convert integer value to a narrowed long type dependent on ctrl (for example, a range check)
4534 Node* Compile::constrained_convI2L(PhaseGVN* phase, Node* value, const TypeInt* itype, Node* ctrl, bool carry_dependency) {
4535   if (ctrl != nullptr) {
4536     // Express control dependency by a CastII node with a narrow type.
4537     // Make the CastII node dependent on the control input to prevent the narrowed ConvI2L
4538     // node from floating above the range check during loop optimizations. Otherwise, the
4539     // ConvI2L node may be eliminated independently of the range check, causing the data path
4540     // to become TOP while the control path is still there (although it's unreachable).
4541     value = new CastIINode(ctrl, value, itype, carry_dependency ? ConstraintCastNode::DependencyType::NonFloatingNarrowing : ConstraintCastNode::DependencyType::FloatingNarrowing, true /* range check dependency */);
4542     value = phase->transform(value);
4543   }
4544   const TypeLong* ltype = TypeLong::make(itype->_lo, itype->_hi, itype->_widen);
4545   return phase->transform(new ConvI2LNode(value, ltype));
4546 }
4547 
4548 void Compile::dump_print_inlining() {
4549   inline_printer()->print_on(tty);
4550 }
4551 
4552 void Compile::log_late_inline(CallGenerator* cg) {
4553   if (log() != nullptr) {
4554     log()->head("late_inline method='%d' inline_id='" JLONG_FORMAT "'", log()->identify(cg->method()),
4555                 cg->unique_id());
4556     JVMState* p = cg->call_node()->jvms();
4557     while (p != nullptr) {
4558       log()->elem("jvms bci='%d' method='%d'", p->bci(), log()->identify(p->method()));
4559       p = p->caller();
4560     }
4561     log()->tail("late_inline");
4562   }
4563 }
4564 
4565 void Compile::log_late_inline_failure(CallGenerator* cg, const char* msg) {
4566   log_late_inline(cg);
4567   if (log() != nullptr) {
4568     log()->inline_fail(msg);
4569   }
4570 }
4571 
4572 void Compile::log_inline_id(CallGenerator* cg) {
4573   if (log() != nullptr) {
4574     // The LogCompilation tool needs a unique way to identify late
4575     // inline call sites. This id must be unique for this call site in
4576     // this compilation. Try to have it unique across compilations as
4577     // well because it can be convenient when grepping through the log
4578     // file.
4579     // Distinguish OSR compilations from others in case CICountOSR is
4580     // on.
4581     jlong id = ((jlong)unique()) + (((jlong)compile_id()) << 33) + (CICountOSR && is_osr_compilation() ? ((jlong)1) << 32 : 0);
4582     cg->set_unique_id(id);
4583     log()->elem("inline_id id='" JLONG_FORMAT "'", id);
4584   }
4585 }
4586 
4587 void Compile::log_inline_failure(const char* msg) {
4588   if (C->log() != nullptr) {
4589     C->log()->inline_fail(msg);
4590   }
4591 }
4592 
4593 
4594 // Dump inlining replay data to the stream.
4595 // Don't change thread state and acquire any locks.
4596 void Compile::dump_inline_data(outputStream* out) {
4597   InlineTree* inl_tree = ilt();
4598   if (inl_tree != nullptr) {
4599     out->print(" inline %d", inl_tree->count());
4600     inl_tree->dump_replay_data(out);
4601   }
4602 }
4603 
4604 void Compile::dump_inline_data_reduced(outputStream* out) {
4605   assert(ReplayReduce, "");
4606 
4607   InlineTree* inl_tree = ilt();
4608   if (inl_tree == nullptr) {
4609     return;
4610   }
4611   // Enable iterative replay file reduction
4612   // Output "compile" lines for depth 1 subtrees,
4613   // simulating that those trees were compiled
4614   // instead of inlined.
4615   for (int i = 0; i < inl_tree->subtrees().length(); ++i) {
4616     InlineTree* sub = inl_tree->subtrees().at(i);
4617     if (sub->inline_level() != 1) {
4618       continue;
4619     }
4620 
4621     ciMethod* method = sub->method();
4622     int entry_bci = -1;
4623     int comp_level = env()->task()->comp_level();
4624     out->print("compile ");
4625     method->dump_name_as_ascii(out);
4626     out->print(" %d %d", entry_bci, comp_level);
4627     out->print(" inline %d", sub->count());
4628     sub->dump_replay_data(out, -1);
4629     out->cr();
4630   }
4631 }
4632 
4633 int Compile::cmp_expensive_nodes(Node* n1, Node* n2) {
4634   if (n1->Opcode() < n2->Opcode())      return -1;
4635   else if (n1->Opcode() > n2->Opcode()) return 1;
4636 
4637   assert(n1->req() == n2->req(), "can't compare %s nodes: n1->req() = %d, n2->req() = %d", NodeClassNames[n1->Opcode()], n1->req(), n2->req());
4638   for (uint i = 1; i < n1->req(); i++) {
4639     if (n1->in(i) < n2->in(i))      return -1;
4640     else if (n1->in(i) > n2->in(i)) return 1;
4641   }
4642 
4643   return 0;
4644 }
4645 
4646 int Compile::cmp_expensive_nodes(Node** n1p, Node** n2p) {
4647   Node* n1 = *n1p;
4648   Node* n2 = *n2p;
4649 
4650   return cmp_expensive_nodes(n1, n2);
4651 }
4652 
4653 void Compile::sort_expensive_nodes() {
4654   if (!expensive_nodes_sorted()) {
4655     _expensive_nodes.sort(cmp_expensive_nodes);
4656   }
4657 }
4658 
4659 bool Compile::expensive_nodes_sorted() const {
4660   for (int i = 1; i < _expensive_nodes.length(); i++) {
4661     if (cmp_expensive_nodes(_expensive_nodes.adr_at(i), _expensive_nodes.adr_at(i-1)) < 0) {
4662       return false;
4663     }
4664   }
4665   return true;
4666 }
4667 
4668 bool Compile::should_optimize_expensive_nodes(PhaseIterGVN &igvn) {
4669   if (_expensive_nodes.length() == 0) {
4670     return false;
4671   }
4672 
4673   assert(OptimizeExpensiveOps, "optimization off?");
4674 
4675   // Take this opportunity to remove dead nodes from the list
4676   int j = 0;
4677   for (int i = 0; i < _expensive_nodes.length(); i++) {
4678     Node* n = _expensive_nodes.at(i);
4679     if (!n->is_unreachable(igvn)) {
4680       assert(n->is_expensive(), "should be expensive");
4681       _expensive_nodes.at_put(j, n);
4682       j++;
4683     }
4684   }
4685   _expensive_nodes.trunc_to(j);
4686 
4687   // Then sort the list so that similar nodes are next to each other
4688   // and check for at least two nodes of identical kind with same data
4689   // inputs.
4690   sort_expensive_nodes();
4691 
4692   for (int i = 0; i < _expensive_nodes.length()-1; i++) {
4693     if (cmp_expensive_nodes(_expensive_nodes.adr_at(i), _expensive_nodes.adr_at(i+1)) == 0) {
4694       return true;
4695     }
4696   }
4697 
4698   return false;
4699 }
4700 
4701 void Compile::cleanup_expensive_nodes(PhaseIterGVN &igvn) {
4702   if (_expensive_nodes.length() == 0) {
4703     return;
4704   }
4705 
4706   assert(OptimizeExpensiveOps, "optimization off?");
4707 
4708   // Sort to bring similar nodes next to each other and clear the
4709   // control input of nodes for which there's only a single copy.
4710   sort_expensive_nodes();
4711 
4712   int j = 0;
4713   int identical = 0;
4714   int i = 0;
4715   bool modified = false;
4716   for (; i < _expensive_nodes.length()-1; i++) {
4717     assert(j <= i, "can't write beyond current index");
4718     if (_expensive_nodes.at(i)->Opcode() == _expensive_nodes.at(i+1)->Opcode()) {
4719       identical++;
4720       _expensive_nodes.at_put(j++, _expensive_nodes.at(i));
4721       continue;
4722     }
4723     if (identical > 0) {
4724       _expensive_nodes.at_put(j++, _expensive_nodes.at(i));
4725       identical = 0;
4726     } else {
4727       Node* n = _expensive_nodes.at(i);
4728       igvn.replace_input_of(n, 0, nullptr);
4729       igvn.hash_insert(n);
4730       modified = true;
4731     }
4732   }
4733   if (identical > 0) {
4734     _expensive_nodes.at_put(j++, _expensive_nodes.at(i));
4735   } else if (_expensive_nodes.length() >= 1) {
4736     Node* n = _expensive_nodes.at(i);
4737     igvn.replace_input_of(n, 0, nullptr);
4738     igvn.hash_insert(n);
4739     modified = true;
4740   }
4741   _expensive_nodes.trunc_to(j);
4742   if (modified) {
4743     igvn.optimize();
4744   }
4745 }
4746 
4747 void Compile::add_expensive_node(Node * n) {
4748   assert(!_expensive_nodes.contains(n), "duplicate entry in expensive list");
4749   assert(n->is_expensive(), "expensive nodes with non-null control here only");
4750   assert(!n->is_CFG() && !n->is_Mem(), "no cfg or memory nodes here");
4751   if (OptimizeExpensiveOps) {
4752     _expensive_nodes.append(n);
4753   } else {
4754     // Clear control input and let IGVN optimize expensive nodes if
4755     // OptimizeExpensiveOps is off.
4756     n->set_req(0, nullptr);
4757   }
4758 }
4759 
4760 /**
4761  * Track coarsened Lock and Unlock nodes.
4762  */
4763 
4764 class Lock_List : public Node_List {
4765   uint _origin_cnt;
4766 public:
4767   Lock_List(Arena *a, uint cnt) : Node_List(a), _origin_cnt(cnt) {}
4768   uint origin_cnt() const { return _origin_cnt; }
4769 };
4770 
4771 void Compile::add_coarsened_locks(GrowableArray<AbstractLockNode*>& locks) {
4772   int length = locks.length();
4773   if (length > 0) {
4774     // Have to keep this list until locks elimination during Macro nodes elimination.
4775     Lock_List* locks_list = new (comp_arena()) Lock_List(comp_arena(), length);
4776     AbstractLockNode* alock = locks.at(0);
4777     BoxLockNode* box = alock->box_node()->as_BoxLock();
4778     for (int i = 0; i < length; i++) {
4779       AbstractLockNode* lock = locks.at(i);
4780       assert(lock->is_coarsened(), "expecting only coarsened AbstractLock nodes, but got '%s'[%d] node", lock->Name(), lock->_idx);
4781       locks_list->push(lock);
4782       BoxLockNode* this_box = lock->box_node()->as_BoxLock();
4783       if (this_box != box) {
4784         // Locking regions (BoxLock) could be Unbalanced here:
4785         //  - its coarsened locks were eliminated in earlier
4786         //    macro nodes elimination followed by loop unroll
4787         //  - it is OSR locking region (no Lock node)
4788         // Preserve Unbalanced status in such cases.
4789         if (!this_box->is_unbalanced()) {
4790           this_box->set_coarsened();
4791         }
4792         if (!box->is_unbalanced()) {
4793           box->set_coarsened();
4794         }
4795       }
4796     }
4797     _coarsened_locks.append(locks_list);
4798   }
4799 }
4800 
4801 void Compile::remove_useless_coarsened_locks(Unique_Node_List& useful) {
4802   int count = coarsened_count();
4803   for (int i = 0; i < count; i++) {
4804     Node_List* locks_list = _coarsened_locks.at(i);
4805     for (uint j = 0; j < locks_list->size(); j++) {
4806       Node* lock = locks_list->at(j);
4807       assert(lock->is_AbstractLock(), "sanity");
4808       if (!useful.member(lock)) {
4809         locks_list->yank(lock);
4810       }
4811     }
4812   }
4813 }
4814 
4815 void Compile::remove_coarsened_lock(Node* n) {
4816   if (n->is_AbstractLock()) {
4817     int count = coarsened_count();
4818     for (int i = 0; i < count; i++) {
4819       Node_List* locks_list = _coarsened_locks.at(i);
4820       locks_list->yank(n);
4821     }
4822   }
4823 }
4824 
4825 bool Compile::coarsened_locks_consistent() {
4826   int count = coarsened_count();
4827   for (int i = 0; i < count; i++) {
4828     bool unbalanced = false;
4829     bool modified = false; // track locks kind modifications
4830     Lock_List* locks_list = (Lock_List*)_coarsened_locks.at(i);
4831     uint size = locks_list->size();
4832     if (size == 0) {
4833       unbalanced = false; // All locks were eliminated - good
4834     } else if (size != locks_list->origin_cnt()) {
4835       unbalanced = true; // Some locks were removed from list
4836     } else {
4837       for (uint j = 0; j < size; j++) {
4838         Node* lock = locks_list->at(j);
4839         // All nodes in group should have the same state (modified or not)
4840         if (!lock->as_AbstractLock()->is_coarsened()) {
4841           if (j == 0) {
4842             // first on list was modified, the rest should be too for consistency
4843             modified = true;
4844           } else if (!modified) {
4845             // this lock was modified but previous locks on the list were not
4846             unbalanced = true;
4847             break;
4848           }
4849         } else if (modified) {
4850           // previous locks on list were modified but not this lock
4851           unbalanced = true;
4852           break;
4853         }
4854       }
4855     }
4856     if (unbalanced) {
4857       // unbalanced monitor enter/exit - only some [un]lock nodes were removed or modified
4858 #ifdef ASSERT
4859       if (PrintEliminateLocks) {
4860         tty->print_cr("=== unbalanced coarsened locks ===");
4861         for (uint l = 0; l < size; l++) {
4862           locks_list->at(l)->dump();
4863         }
4864       }
4865 #endif
4866       record_failure(C2Compiler::retry_no_locks_coarsening());
4867       return false;
4868     }
4869   }
4870   return true;
4871 }
4872 
4873 // Mark locking regions (identified by BoxLockNode) as unbalanced if
4874 // locks coarsening optimization removed Lock/Unlock nodes from them.
4875 // Such regions become unbalanced because coarsening only removes part
4876 // of Lock/Unlock nodes in region. As result we can't execute other
4877 // locks elimination optimizations which assume all code paths have
4878 // corresponding pair of Lock/Unlock nodes - they are balanced.
4879 void Compile::mark_unbalanced_boxes() const {
4880   int count = coarsened_count();
4881   for (int i = 0; i < count; i++) {
4882     Node_List* locks_list = _coarsened_locks.at(i);
4883     uint size = locks_list->size();
4884     if (size > 0) {
4885       AbstractLockNode* alock = locks_list->at(0)->as_AbstractLock();
4886       BoxLockNode* box = alock->box_node()->as_BoxLock();
4887       if (alock->is_coarsened()) {
4888         // coarsened_locks_consistent(), which is called before this method, verifies
4889         // that the rest of Lock/Unlock nodes on locks_list are also coarsened.
4890         assert(!box->is_eliminated(), "regions with coarsened locks should not be marked as eliminated");
4891         for (uint j = 1; j < size; j++) {
4892           assert(locks_list->at(j)->as_AbstractLock()->is_coarsened(), "only coarsened locks are expected here");
4893           BoxLockNode* this_box = locks_list->at(j)->as_AbstractLock()->box_node()->as_BoxLock();
4894           if (box != this_box) {
4895             assert(!this_box->is_eliminated(), "regions with coarsened locks should not be marked as eliminated");
4896             box->set_unbalanced();
4897             this_box->set_unbalanced();
4898           }
4899         }
4900       }
4901     }
4902   }
4903 }
4904 
4905 /**
4906  * Remove the speculative part of types and clean up the graph
4907  */
4908 void Compile::remove_speculative_types(PhaseIterGVN &igvn) {
4909   if (UseTypeSpeculation) {
4910     Unique_Node_List worklist;
4911     worklist.push(root());
4912     int modified = 0;
4913     // Go over all type nodes that carry a speculative type, drop the
4914     // speculative part of the type and enqueue the node for an igvn
4915     // which may optimize it out.
4916     for (uint next = 0; next < worklist.size(); ++next) {
4917       Node *n  = worklist.at(next);
4918       if (n->is_Type()) {
4919         TypeNode* tn = n->as_Type();
4920         const Type* t = tn->type();
4921         const Type* t_no_spec = t->remove_speculative();
4922         if (t_no_spec != t) {
4923           bool in_hash = igvn.hash_delete(n);
4924           assert(in_hash || n->hash() == Node::NO_HASH, "node should be in igvn hash table");
4925           tn->set_type(t_no_spec);
4926           igvn.hash_insert(n);
4927           igvn._worklist.push(n); // give it a chance to go away
4928           modified++;
4929         }
4930       }
4931       // Iterate over outs - endless loops is unreachable from below
4932       for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
4933         Node *m = n->fast_out(i);
4934         if (not_a_node(m)) {
4935           continue;
4936         }
4937         worklist.push(m);
4938       }
4939     }
4940     // Drop the speculative part of all types in the igvn's type table
4941     igvn.remove_speculative_types();
4942     if (modified > 0) {
4943       igvn.optimize();
4944       if (failing())  return;
4945     }
4946 #ifdef ASSERT
4947     // Verify that after the IGVN is over no speculative type has resurfaced
4948     worklist.clear();
4949     worklist.push(root());
4950     for (uint next = 0; next < worklist.size(); ++next) {
4951       Node *n  = worklist.at(next);
4952       const Type* t = igvn.type_or_null(n);
4953       assert((t == nullptr) || (t == t->remove_speculative()), "no more speculative types");
4954       if (n->is_Type()) {
4955         t = n->as_Type()->type();
4956         assert(t == t->remove_speculative(), "no more speculative types");
4957       }
4958       // Iterate over outs - endless loops is unreachable from below
4959       for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
4960         Node *m = n->fast_out(i);
4961         if (not_a_node(m)) {
4962           continue;
4963         }
4964         worklist.push(m);
4965       }
4966     }
4967     igvn.check_no_speculative_types();
4968 #endif
4969   }
4970 }
4971 
4972 // Auxiliary methods to support randomized stressing/fuzzing.
4973 
4974 void Compile::initialize_stress_seed(const DirectiveSet* directive) {
4975   if (FLAG_IS_DEFAULT(StressSeed) || (FLAG_IS_ERGO(StressSeed) && directive->RepeatCompilationOption)) {
4976     _stress_seed = static_cast<uint>(Ticks::now().nanoseconds());
4977     FLAG_SET_ERGO(StressSeed, _stress_seed);
4978   } else {
4979     _stress_seed = StressSeed;
4980   }
4981   if (_log != nullptr) {
4982     _log->elem("stress_test seed='%u'", _stress_seed);
4983   }
4984 }
4985 
4986 int Compile::random() {
4987   _stress_seed = os::next_random(_stress_seed);
4988   return static_cast<int>(_stress_seed);
4989 }
4990 
4991 // This method can be called the arbitrary number of times, with current count
4992 // as the argument. The logic allows selecting a single candidate from the
4993 // running list of candidates as follows:
4994 //    int count = 0;
4995 //    Cand* selected = null;
4996 //    while(cand = cand->next()) {
4997 //      if (randomized_select(++count)) {
4998 //        selected = cand;
4999 //      }
5000 //    }
5001 //
5002 // Including count equalizes the chances any candidate is "selected".
5003 // This is useful when we don't have the complete list of candidates to choose
5004 // from uniformly. In this case, we need to adjust the randomicity of the
5005 // selection, or else we will end up biasing the selection towards the latter
5006 // candidates.
5007 //
5008 // Quick back-envelope calculation shows that for the list of n candidates
5009 // the equal probability for the candidate to persist as "best" can be
5010 // achieved by replacing it with "next" k-th candidate with the probability
5011 // of 1/k. It can be easily shown that by the end of the run, the
5012 // probability for any candidate is converged to 1/n, thus giving the
5013 // uniform distribution among all the candidates.
5014 //
5015 // We don't care about the domain size as long as (RANDOMIZED_DOMAIN / count) is large.
5016 #define RANDOMIZED_DOMAIN_POW 29
5017 #define RANDOMIZED_DOMAIN (1 << RANDOMIZED_DOMAIN_POW)
5018 #define RANDOMIZED_DOMAIN_MASK ((1 << (RANDOMIZED_DOMAIN_POW + 1)) - 1)
5019 bool Compile::randomized_select(int count) {
5020   assert(count > 0, "only positive");
5021   return (random() & RANDOMIZED_DOMAIN_MASK) < (RANDOMIZED_DOMAIN / count);
5022 }
5023 
5024 #ifdef ASSERT
5025 // Failures are geometrically distributed with probability 1/StressBailoutMean.
5026 bool Compile::fail_randomly() {
5027   if ((random() % StressBailoutMean) != 0) {
5028     return false;
5029   }
5030   record_failure("StressBailout");
5031   return true;
5032 }
5033 
5034 bool Compile::failure_is_artificial() {
5035   return C->failure_reason_is("StressBailout");
5036 }
5037 #endif
5038 
5039 CloneMap&     Compile::clone_map()                 { return _clone_map; }
5040 void          Compile::set_clone_map(Dict* d)      { _clone_map._dict = d; }
5041 
5042 void NodeCloneInfo::dump_on(outputStream* st) const {
5043   st->print(" {%d:%d} ", idx(), gen());
5044 }
5045 
5046 void CloneMap::clone(Node* old, Node* nnn, int gen) {
5047   uint64_t val = value(old->_idx);
5048   NodeCloneInfo cio(val);
5049   assert(val != 0, "old node should be in the map");
5050   NodeCloneInfo cin(cio.idx(), gen + cio.gen());
5051   insert(nnn->_idx, cin.get());
5052 #ifndef PRODUCT
5053   if (is_debug()) {
5054     tty->print_cr("CloneMap::clone inserted node %d info {%d:%d} into CloneMap", nnn->_idx, cin.idx(), cin.gen());
5055   }
5056 #endif
5057 }
5058 
5059 void CloneMap::verify_insert_and_clone(Node* old, Node* nnn, int gen) {
5060   NodeCloneInfo cio(value(old->_idx));
5061   if (cio.get() == 0) {
5062     cio.set(old->_idx, 0);
5063     insert(old->_idx, cio.get());
5064 #ifndef PRODUCT
5065     if (is_debug()) {
5066       tty->print_cr("CloneMap::verify_insert_and_clone inserted node %d info {%d:%d} into CloneMap", old->_idx, cio.idx(), cio.gen());
5067     }
5068 #endif
5069   }
5070   clone(old, nnn, gen);
5071 }
5072 
5073 int CloneMap::max_gen() const {
5074   int g = 0;
5075   DictI di(_dict);
5076   for(; di.test(); ++di) {
5077     int t = gen(di._key);
5078     if (g < t) {
5079       g = t;
5080 #ifndef PRODUCT
5081       if (is_debug()) {
5082         tty->print_cr("CloneMap::max_gen() update max=%d from %d", g, _2_node_idx_t(di._key));
5083       }
5084 #endif
5085     }
5086   }
5087   return g;
5088 }
5089 
5090 void CloneMap::dump(node_idx_t key, outputStream* st) const {
5091   uint64_t val = value(key);
5092   if (val != 0) {
5093     NodeCloneInfo ni(val);
5094     ni.dump_on(st);
5095   }
5096 }
5097 
5098 void Compile::shuffle_macro_nodes() {
5099   shuffle_array(*C, _macro_nodes);
5100 }
5101 
5102 // Move Allocate nodes to the start of the list
5103 void Compile::sort_macro_nodes() {
5104   int count = macro_count();
5105   int allocates = 0;
5106   for (int i = 0; i < count; i++) {
5107     Node* n = macro_node(i);
5108     if (n->is_Allocate()) {
5109       if (i != allocates) {
5110         Node* tmp = macro_node(allocates);
5111         _macro_nodes.at_put(allocates, n);
5112         _macro_nodes.at_put(i, tmp);
5113       }
5114       allocates++;
5115     }
5116   }
5117 }
5118 
5119 void Compile::print_method(CompilerPhaseType compile_phase, int level, Node* n) {
5120   if (failing_internal()) { return; } // failing_internal to not stress bailouts from printing code.
5121   EventCompilerPhase event(UNTIMED);
5122   if (event.should_commit()) {
5123     CompilerEvent::PhaseEvent::post(event, C->_latest_stage_start_counter, compile_phase, C->_compile_id, level);
5124   }
5125 #ifndef PRODUCT
5126   ResourceMark rm;
5127   stringStream ss;
5128   ss.print_raw(CompilerPhaseTypeHelper::to_description(compile_phase));
5129   int iter = ++_igv_phase_iter[compile_phase];
5130   if (iter > 1) {
5131     ss.print(" %d", iter);
5132   }
5133   if (n != nullptr) {
5134     ss.print(": %d %s", n->_idx, NodeClassNames[n->Opcode()]);
5135     if (n->is_Call()) {
5136       CallNode* call = n->as_Call();
5137       if (call->_name != nullptr) {
5138         // E.g. uncommon traps etc.
5139         ss.print(" - %s", call->_name);
5140       } else if (call->is_CallJava()) {
5141         CallJavaNode* call_java = call->as_CallJava();
5142         if (call_java->method() != nullptr) {
5143           ss.print(" -");
5144           call_java->method()->print_short_name(&ss);
5145         }
5146       }
5147     }
5148   }
5149 
5150   const char* name = ss.as_string();
5151   if (should_print_igv(level)) {
5152     _igv_printer->print_graph(name);
5153   }
5154   if (should_print_phase(level)) {
5155     print_phase(name);
5156   }
5157   if (should_print_ideal_phase(compile_phase)) {
5158     print_ideal_ir(CompilerPhaseTypeHelper::to_name(compile_phase));
5159   }
5160 #endif
5161   C->_latest_stage_start_counter.stamp();
5162 }
5163 
5164 // Only used from CompileWrapper
5165 void Compile::begin_method() {
5166 #ifndef PRODUCT
5167   if (_method != nullptr && should_print_igv(1)) {
5168     _igv_printer->begin_method();
5169   }
5170 #endif
5171   C->_latest_stage_start_counter.stamp();
5172 }
5173 
5174 // Only used from CompileWrapper
5175 void Compile::end_method() {
5176   EventCompilerPhase event(UNTIMED);
5177   if (event.should_commit()) {
5178     CompilerEvent::PhaseEvent::post(event, C->_latest_stage_start_counter, PHASE_END, C->_compile_id, 1);
5179   }
5180 
5181 #ifndef PRODUCT
5182   if (_method != nullptr && should_print_igv(1)) {
5183     _igv_printer->end_method();
5184   }
5185 #endif
5186 }
5187 
5188 #ifndef PRODUCT
5189 bool Compile::should_print_phase(const int level) const {
5190   return PrintPhaseLevel >= 0 && directive()->PhasePrintLevelOption >= level &&
5191          _method != nullptr; // Do not print phases for stubs.
5192 }
5193 
5194 bool Compile::should_print_ideal_phase(CompilerPhaseType cpt) const {
5195   return _directive->should_print_ideal_phase(cpt);
5196 }
5197 
5198 void Compile::init_igv() {
5199   if (_igv_printer == nullptr) {
5200     _igv_printer = IdealGraphPrinter::printer();
5201     _igv_printer->set_compile(this);
5202   }
5203 }
5204 
5205 bool Compile::should_print_igv(const int level) {
5206   PRODUCT_RETURN_(return false;);
5207 
5208   if (PrintIdealGraphLevel < 0) { // disabled by the user
5209     return false;
5210   }
5211 
5212   bool need = directive()->IGVPrintLevelOption >= level;
5213   if (need) {
5214     Compile::init_igv();
5215   }
5216   return need;
5217 }
5218 
5219 IdealGraphPrinter* Compile::_debug_file_printer = nullptr;
5220 IdealGraphPrinter* Compile::_debug_network_printer = nullptr;
5221 
5222 // Called from debugger. Prints method to the default file with the default phase name.
5223 // This works regardless of any Ideal Graph Visualizer flags set or not.
5224 // Use in debugger (gdb/rr): p igv_print($sp, $fp, $pc).
5225 void igv_print(void* sp, void* fp, void* pc) {
5226   frame fr(sp, fp, pc);
5227   Compile::current()->igv_print_method_to_file(nullptr, false, &fr);
5228 }
5229 
5230 // Same as igv_print() above but with a specified phase name.
5231 void igv_print(const char* phase_name, void* sp, void* fp, void* pc) {
5232   frame fr(sp, fp, pc);
5233   Compile::current()->igv_print_method_to_file(phase_name, false, &fr);
5234 }
5235 
5236 // Called from debugger. Prints method with the default phase name to the default network or the one specified with
5237 // the network flags for the Ideal Graph Visualizer, or to the default file depending on the 'network' argument.
5238 // This works regardless of any Ideal Graph Visualizer flags set or not.
5239 // Use in debugger (gdb/rr): p igv_print(true, $sp, $fp, $pc).
5240 void igv_print(bool network, void* sp, void* fp, void* pc) {
5241   frame fr(sp, fp, pc);
5242   if (network) {
5243     Compile::current()->igv_print_method_to_network(nullptr, &fr);
5244   } else {
5245     Compile::current()->igv_print_method_to_file(nullptr, false, &fr);
5246   }
5247 }
5248 
5249 // Same as igv_print(bool network, ...) above but with a specified phase name.
5250 // Use in debugger (gdb/rr): p igv_print(true, "MyPhase", $sp, $fp, $pc).
5251 void igv_print(bool network, const char* phase_name, void* sp, void* fp, void* pc) {
5252   frame fr(sp, fp, pc);
5253   if (network) {
5254     Compile::current()->igv_print_method_to_network(phase_name, &fr);
5255   } else {
5256     Compile::current()->igv_print_method_to_file(phase_name, false, &fr);
5257   }
5258 }
5259 
5260 // Called from debugger. Normal write to the default _printer. Only works if Ideal Graph Visualizer printing flags are set.
5261 void igv_print_default() {
5262   Compile::current()->print_method(PHASE_DEBUG, 0);
5263 }
5264 
5265 // Called from debugger, especially when replaying a trace in which the program state cannot be altered like with rr replay.
5266 // A method is appended to an existing default file with the default phase name. This means that igv_append() must follow
5267 // an earlier igv_print(*) call which sets up the file. This works regardless of any Ideal Graph Visualizer flags set or not.
5268 // Use in debugger (gdb/rr): p igv_append($sp, $fp, $pc).
5269 void igv_append(void* sp, void* fp, void* pc) {
5270   frame fr(sp, fp, pc);
5271   Compile::current()->igv_print_method_to_file(nullptr, true, &fr);
5272 }
5273 
5274 // Same as igv_append(...) above but with a specified phase name.
5275 // Use in debugger (gdb/rr): p igv_append("MyPhase", $sp, $fp, $pc).
5276 void igv_append(const char* phase_name, void* sp, void* fp, void* pc) {
5277   frame fr(sp, fp, pc);
5278   Compile::current()->igv_print_method_to_file(phase_name, true, &fr);
5279 }
5280 
5281 void Compile::igv_print_method_to_file(const char* phase_name, bool append, const frame* fr) {
5282   const char* file_name = "custom_debug.xml";
5283   if (_debug_file_printer == nullptr) {
5284     _debug_file_printer = new IdealGraphPrinter(C, file_name, append);
5285   } else {
5286     _debug_file_printer->update_compiled_method(C->method());
5287   }
5288   tty->print_cr("Method %s to %s", append ? "appended" : "printed", file_name);
5289   _debug_file_printer->print_graph(phase_name, fr);
5290 }
5291 
5292 void Compile::igv_print_method_to_network(const char* phase_name, const frame* fr) {
5293   ResourceMark rm;
5294   GrowableArray<const Node*> empty_list;
5295   igv_print_graph_to_network(phase_name, empty_list, fr);
5296 }
5297 
5298 void Compile::igv_print_graph_to_network(const char* name, GrowableArray<const Node*>& visible_nodes, const frame* fr) {
5299   if (_debug_network_printer == nullptr) {
5300     _debug_network_printer = new IdealGraphPrinter(C);
5301   } else {
5302     _debug_network_printer->update_compiled_method(C->method());
5303   }
5304   tty->print_cr("Method printed over network stream to IGV");
5305   _debug_network_printer->print(name, C->root(), visible_nodes, fr);
5306 }
5307 #endif // !PRODUCT
5308 
5309 Node* Compile::narrow_value(BasicType bt, Node* value, const Type* type, PhaseGVN* phase, bool transform_res) {
5310   if (type != nullptr && phase->type(value)->higher_equal(type)) {
5311     return value;
5312   }
5313   Node* result = nullptr;
5314   if (bt == T_BYTE) {
5315     result = phase->transform(new LShiftINode(value, phase->intcon(24)));
5316     result = new RShiftINode(result, phase->intcon(24));
5317   } else if (bt == T_BOOLEAN) {
5318     result = new AndINode(value, phase->intcon(0xFF));
5319   } else if (bt == T_CHAR) {
5320     result = new AndINode(value,phase->intcon(0xFFFF));
5321   } else {
5322     assert(bt == T_SHORT, "unexpected narrow type");
5323     result = phase->transform(new LShiftINode(value, phase->intcon(16)));
5324     result = new RShiftINode(result, phase->intcon(16));
5325   }
5326   if (transform_res) {
5327     result = phase->transform(result);
5328   }
5329   return result;
5330 }
5331 
5332 void Compile::record_method_not_compilable_oom() {
5333   record_method_not_compilable(CompilationMemoryStatistic::failure_reason_memlimit());
5334 }
5335 
5336 #ifndef PRODUCT
5337 // Collects all the control inputs from nodes on the worklist and from their data dependencies
5338 static void find_candidate_control_inputs(Unique_Node_List& worklist, Unique_Node_List& candidates) {
5339   // Follow non-control edges until we reach CFG nodes
5340   for (uint i = 0; i < worklist.size(); i++) {
5341     const Node* n = worklist.at(i);
5342     for (uint j = 0; j < n->req(); j++) {
5343       Node* in = n->in(j);
5344       if (in == nullptr || in->is_Root()) {
5345         continue;
5346       }
5347       if (in->is_CFG()) {
5348         if (in->is_Call()) {
5349           // The return value of a call is only available if the call did not result in an exception
5350           Node* control_proj_use = in->as_Call()->proj_out(TypeFunc::Control)->unique_out();
5351           if (control_proj_use->is_Catch()) {
5352             Node* fall_through = control_proj_use->as_Catch()->proj_out(CatchProjNode::fall_through_index);
5353             candidates.push(fall_through);
5354             continue;
5355           }
5356         }
5357 
5358         if (in->is_Multi()) {
5359           // We got here by following data inputs so we should only have one control use
5360           // (no IfNode, etc)
5361           assert(!n->is_MultiBranch(), "unexpected node type: %s", n->Name());
5362           candidates.push(in->as_Multi()->proj_out(TypeFunc::Control));
5363         } else {
5364           candidates.push(in);
5365         }
5366       } else {
5367         worklist.push(in);
5368       }
5369     }
5370   }
5371 }
5372 
5373 // Returns the candidate node that is a descendant to all the other candidates
5374 static Node* pick_control(Unique_Node_List& candidates) {
5375   Unique_Node_List worklist;
5376   worklist.copy(candidates);
5377 
5378   // Traverse backwards through the CFG
5379   for (uint i = 0; i < worklist.size(); i++) {
5380     const Node* n = worklist.at(i);
5381     if (n->is_Root()) {
5382       continue;
5383     }
5384     for (uint j = 0; j < n->req(); j++) {
5385       // Skip backedge of loops to avoid cycles
5386       if (n->is_Loop() && j == LoopNode::LoopBackControl) {
5387         continue;
5388       }
5389 
5390       Node* pred = n->in(j);
5391       if (pred != nullptr && pred != n && pred->is_CFG()) {
5392         worklist.push(pred);
5393         // if pred is an ancestor of n, then pred is an ancestor to at least one candidate
5394         candidates.remove(pred);
5395       }
5396     }
5397   }
5398 
5399   assert(candidates.size() == 1, "unexpected control flow");
5400   return candidates.at(0);
5401 }
5402 
5403 // Initialize a parameter input for a debug print call, using a placeholder for jlong and jdouble
5404 static void debug_print_init_parm(Node* call, Node* parm, Node* half, int* pos) {
5405   call->init_req((*pos)++, parm);
5406   const BasicType bt = parm->bottom_type()->basic_type();
5407   if (bt == T_LONG || bt == T_DOUBLE) {
5408     call->init_req((*pos)++, half);
5409   }
5410 }
5411 
5412 Node* Compile::make_debug_print_call(const char* str, address call_addr, PhaseGVN* gvn,
5413                               Node* parm0, Node* parm1,
5414                               Node* parm2, Node* parm3,
5415                               Node* parm4, Node* parm5,
5416                               Node* parm6) const {
5417   Node* str_node = gvn->transform(new ConPNode(TypeRawPtr::make(((address) str))));
5418   const TypeFunc* type = OptoRuntime::debug_print_Type(parm0, parm1, parm2, parm3, parm4, parm5, parm6);
5419   Node* call = new CallLeafNode(type, call_addr, "debug_print", TypeRawPtr::BOTTOM);
5420 
5421   // find the most suitable control input
5422   Unique_Node_List worklist, candidates;
5423   if (parm0 != nullptr) { worklist.push(parm0);
5424   if (parm1 != nullptr) { worklist.push(parm1);
5425   if (parm2 != nullptr) { worklist.push(parm2);
5426   if (parm3 != nullptr) { worklist.push(parm3);
5427   if (parm4 != nullptr) { worklist.push(parm4);
5428   if (parm5 != nullptr) { worklist.push(parm5);
5429   if (parm6 != nullptr) { worklist.push(parm6);
5430   /* close each nested if ===> */  } } } } } } }
5431   find_candidate_control_inputs(worklist, candidates);
5432   Node* control = nullptr;
5433   if (candidates.size() == 0) {
5434     control = C->start()->proj_out(TypeFunc::Control);
5435   } else {
5436     control = pick_control(candidates);
5437   }
5438 
5439   // find all the previous users of the control we picked
5440   GrowableArray<Node*> users_of_control;
5441   for (DUIterator_Fast kmax, i = control->fast_outs(kmax); i < kmax; i++) {
5442     Node* use = control->fast_out(i);
5443     if (use->is_CFG() && use != control) {
5444       users_of_control.push(use);
5445     }
5446   }
5447 
5448   // we do not actually care about IO and memory as it uses neither
5449   call->init_req(TypeFunc::Control,   control);
5450   call->init_req(TypeFunc::I_O,       top());
5451   call->init_req(TypeFunc::Memory,    top());
5452   call->init_req(TypeFunc::FramePtr,  C->start()->proj_out(TypeFunc::FramePtr));
5453   call->init_req(TypeFunc::ReturnAdr, top());
5454 
5455   int pos = TypeFunc::Parms;
5456   call->init_req(pos++, str_node);
5457   if (parm0 != nullptr) { debug_print_init_parm(call, parm0, top(), &pos);
5458   if (parm1 != nullptr) { debug_print_init_parm(call, parm1, top(), &pos);
5459   if (parm2 != nullptr) { debug_print_init_parm(call, parm2, top(), &pos);
5460   if (parm3 != nullptr) { debug_print_init_parm(call, parm3, top(), &pos);
5461   if (parm4 != nullptr) { debug_print_init_parm(call, parm4, top(), &pos);
5462   if (parm5 != nullptr) { debug_print_init_parm(call, parm5, top(), &pos);
5463   if (parm6 != nullptr) { debug_print_init_parm(call, parm6, top(), &pos);
5464   /* close each nested if ===> */  } } } } } } }
5465   assert(call->in(call->req()-1) != nullptr, "must initialize all parms");
5466 
5467   call = gvn->transform(call);
5468   Node* call_control_proj = gvn->transform(new ProjNode(call, TypeFunc::Control));
5469 
5470   // rewire previous users to have the new call as control instead
5471   PhaseIterGVN* igvn = gvn->is_IterGVN();
5472   for (int i = 0; i < users_of_control.length(); i++) {
5473     Node* use = users_of_control.at(i);
5474     for (uint j = 0; j < use->req(); j++) {
5475       if (use->in(j) == control) {
5476         if (igvn != nullptr) {
5477           igvn->replace_input_of(use, j, call_control_proj);
5478         } else {
5479           gvn->hash_delete(use);
5480           use->set_req(j, call_control_proj);
5481           gvn->hash_insert(use);
5482         }
5483       }
5484     }
5485   }
5486 
5487   return call;
5488 }
5489 #endif // !PRODUCT