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   if (dead_path()) { useful.push(dead_path()); }
 316 
 317   // Push all useful nodes onto the list, breadthfirst
 318   for( uint next = 0; next < useful.size(); ++next ) {
 319     assert( next < unique(), "Unique useful nodes < total nodes");
 320     Node *n  = useful.at(next);
 321     uint max = n->len();
 322     for( uint i = 0; i < max; ++i ) {
 323       Node *m = n->in(i);
 324       if (not_a_node(m))  continue;
 325       useful.push(m);
 326     }
 327   }
 328 }
 329 
 330 // Update dead_node_list with any missing dead nodes using useful
 331 // list. Consider all non-useful nodes to be useless i.e., dead nodes.
 332 void Compile::update_dead_node_list(Unique_Node_List &useful) {
 333   uint max_idx = unique();
 334   VectorSet& useful_node_set = useful.member_set();
 335 
 336   for (uint node_idx = 0; node_idx < max_idx; node_idx++) {
 337     // If node with index node_idx is not in useful set,
 338     // mark it as dead in dead node list.
 339     if (!useful_node_set.test(node_idx)) {
 340       record_dead_node(node_idx);
 341     }
 342   }
 343 }
 344 
 345 void Compile::remove_useless_late_inlines(GrowableArray<CallGenerator*>* inlines, Unique_Node_List &useful) {
 346   int shift = 0;
 347   for (int i = 0; i < inlines->length(); i++) {
 348     CallGenerator* cg = inlines->at(i);
 349     if (useful.member(cg->call_node())) {
 350       if (shift > 0) {
 351         inlines->at_put(i - shift, cg);
 352       }
 353     } else {
 354       shift++; // skip over the dead element
 355     }
 356   }
 357   if (shift > 0) {
 358     inlines->trunc_to(inlines->length() - shift); // remove last elements from compacted array
 359   }
 360 }
 361 
 362 void Compile::remove_useless_late_inlines(GrowableArray<CallGenerator*>* inlines, Node* dead) {
 363   assert(dead != nullptr && dead->is_Call(), "sanity");
 364   int found = 0;
 365   for (int i = 0; i < inlines->length(); i++) {
 366     if (inlines->at(i)->call_node() == dead) {
 367       inlines->remove_at(i);
 368       found++;
 369       NOT_DEBUG( break; ) // elements are unique, so exit early
 370     }
 371   }
 372   assert(found <= 1, "not unique");
 373 }
 374 
 375 template<typename N, ENABLE_IF_SDEFN(std::is_base_of<Node, N>::value)>
 376 void Compile::remove_useless_nodes(GrowableArray<N*>& node_list, Unique_Node_List& useful) {
 377   for (int i = node_list.length() - 1; i >= 0; i--) {
 378     N* node = node_list.at(i);
 379     if (!useful.member(node)) {
 380       node_list.delete_at(i); // replaces i-th with last element which is known to be useful (already processed)
 381     }
 382   }
 383 }
 384 
 385 void Compile::remove_useless_node(Node* dead) {
 386   remove_modified_node(dead);
 387 
 388   // Constant node that has no out-edges and has only one in-edge from
 389   // root is usually dead. However, sometimes reshaping walk makes
 390   // it reachable by adding use edges. So, we will NOT count Con nodes
 391   // as dead to be conservative about the dead node count at any
 392   // given time.
 393   if (!dead->is_Con() && dead != dead_path()) {
 394     record_dead_node(dead->_idx);
 395   }
 396   if (dead->is_macro()) {
 397     remove_macro_node(dead);
 398   }
 399   if (dead->is_expensive()) {
 400     remove_expensive_node(dead);
 401   }
 402   if (dead->is_ReachabilityFence()) {
 403     remove_reachability_fence(dead->as_ReachabilityFence());
 404   }
 405   if (dead->is_OpaqueTemplateAssertionPredicate()) {
 406     remove_template_assertion_predicate_opaque(dead->as_OpaqueTemplateAssertionPredicate());
 407   }
 408   if (dead->is_ParsePredicate()) {
 409     remove_parse_predicate(dead->as_ParsePredicate());
 410   }
 411   if (dead->for_post_loop_opts_igvn()) {
 412     remove_from_post_loop_opts_igvn(dead);
 413   }
 414   if (dead->for_merge_stores_igvn()) {
 415     remove_from_merge_stores_igvn(dead);
 416   }
 417   if (dead->is_Call()) {
 418     remove_useless_late_inlines(                &_late_inlines, dead);
 419     remove_useless_late_inlines(         &_string_late_inlines, dead);
 420     remove_useless_late_inlines(         &_boxing_late_inlines, dead);
 421     remove_useless_late_inlines(&_vector_reboxing_late_inlines, dead);
 422 
 423     if (dead->is_CallStaticJava()) {
 424       remove_unstable_if_trap(dead->as_CallStaticJava(), false);
 425     }
 426   }
 427   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 428   bs->unregister_potential_barrier_node(dead);
 429 }
 430 
 431 // Disconnect all useless nodes by disconnecting those at the boundary.
 432 void Compile::disconnect_useless_nodes(Unique_Node_List& useful, Unique_Node_List& worklist, const Unique_Node_List* root_and_safepoints) {
 433   uint next = 0;
 434   while (next < useful.size()) {
 435     Node *n = useful.at(next++);
 436     if (n->is_SafePoint()) {
 437       // We're done with a parsing phase. Replaced nodes are not valid
 438       // beyond that point.
 439       n->as_SafePoint()->delete_replaced_nodes();
 440     }
 441     // Use raw traversal of out edges since this code removes out edges
 442     int max = n->outcnt();
 443     for (int j = 0; j < max; ++j) {
 444       Node* child = n->raw_out(j);
 445       if (!useful.member(child)) {
 446         assert(!child->is_top() || child != top(),
 447                "If top is cached in Compile object it is in useful list");
 448         // Only need to remove this out-edge to the useless node
 449         n->raw_del_out(j);
 450         --j;
 451         --max;
 452         if (child->is_data_proj_of_pure_function(n)) {
 453           worklist.push(n);
 454         }
 455       }
 456     }
 457     if (n->outcnt() == 1 && n->has_special_unique_user()) {
 458       assert(useful.member(n->unique_out()), "do not push a useless node");
 459       worklist.push(n->unique_out());
 460     }
 461   }
 462 
 463   remove_useless_nodes(_macro_nodes,        useful); // remove useless macro nodes
 464   remove_useless_nodes(_parse_predicates,   useful); // remove useless Parse Predicate nodes
 465   // Remove useless Template Assertion Predicate opaque nodes
 466   remove_useless_nodes(_template_assertion_predicate_opaques, useful);
 467   remove_useless_nodes(_expensive_nodes,    useful); // remove useless expensive nodes
 468   remove_useless_nodes(_reachability_fences, useful); // remove useless node recorded for post loop opts IGVN pass
 469   remove_useless_nodes(_for_post_loop_igvn, useful); // remove useless node recorded for post loop opts IGVN pass
 470   remove_useless_nodes(_for_merge_stores_igvn, useful); // remove useless node recorded for merge stores IGVN pass
 471   remove_useless_unstable_if_traps(useful);          // remove useless unstable_if traps
 472   remove_useless_coarsened_locks(useful);            // remove useless coarsened locks nodes
 473 #ifdef ASSERT
 474   if (_modified_nodes != nullptr) {
 475     _modified_nodes->remove_useless_nodes(useful.member_set());
 476   }
 477 #endif
 478 
 479   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 480   bs->eliminate_useless_gc_barriers(useful, this);
 481   // clean up the late inline lists
 482   remove_useless_late_inlines(                &_late_inlines, useful);
 483   remove_useless_late_inlines(         &_string_late_inlines, useful);
 484   remove_useless_late_inlines(         &_boxing_late_inlines, useful);
 485   remove_useless_late_inlines(&_vector_reboxing_late_inlines, useful);
 486   DEBUG_ONLY(verify_graph_edges(true /*check for no_dead_code*/, root_and_safepoints);)
 487 }
 488 
 489 // ============================================================================
 490 //------------------------------CompileWrapper---------------------------------
 491 class CompileWrapper : public StackObj {
 492   Compile *const _compile;
 493  public:
 494   CompileWrapper(Compile* compile);
 495 
 496   ~CompileWrapper();
 497 };
 498 
 499 CompileWrapper::CompileWrapper(Compile* compile) : _compile(compile) {
 500   // the Compile* pointer is stored in the current ciEnv:
 501   ciEnv* env = compile->env();
 502   assert(env == ciEnv::current(), "must already be a ciEnv active");
 503   assert(env->compiler_data() == nullptr, "compile already active?");
 504   env->set_compiler_data(compile);
 505   assert(compile == Compile::current(), "sanity");
 506 
 507   compile->set_type_dict(nullptr);
 508   compile->set_clone_map(new Dict(cmpkey, hashkey, _compile->comp_arena()));
 509   compile->clone_map().set_clone_idx(0);
 510   compile->set_type_last_size(0);
 511   compile->set_last_tf(nullptr, nullptr);
 512   compile->set_indexSet_arena(nullptr);
 513   compile->set_indexSet_free_block_list(nullptr);
 514   compile->init_type_arena();
 515   Type::Initialize(compile);
 516   _compile->begin_method();
 517   _compile->clone_map().set_debug(_compile->has_method() && _compile->directive()->CloneMapDebugOption);
 518 }
 519 CompileWrapper::~CompileWrapper() {
 520   // simulate crash during compilation
 521   assert(CICrashAt < 0 || _compile->compile_id() != CICrashAt, "just as planned");
 522 
 523   _compile->end_method();
 524   _compile->env()->set_compiler_data(nullptr);
 525 }
 526 
 527 
 528 //----------------------------print_compile_messages---------------------------
 529 void Compile::print_compile_messages() {
 530 #ifndef PRODUCT
 531   // Check if recompiling
 532   if (!subsume_loads() && PrintOpto) {
 533     // Recompiling without allowing machine instructions to subsume loads
 534     tty->print_cr("*********************************************************");
 535     tty->print_cr("** Bailout: Recompile without subsuming loads          **");
 536     tty->print_cr("*********************************************************");
 537   }
 538   if ((do_escape_analysis() != DoEscapeAnalysis) && PrintOpto) {
 539     // Recompiling without escape analysis
 540     tty->print_cr("*********************************************************");
 541     tty->print_cr("** Bailout: Recompile without escape analysis          **");
 542     tty->print_cr("*********************************************************");
 543   }
 544   if (do_iterative_escape_analysis() != DoEscapeAnalysis && PrintOpto) {
 545     // Recompiling without iterative escape analysis
 546     tty->print_cr("*********************************************************");
 547     tty->print_cr("** Bailout: Recompile without iterative escape analysis**");
 548     tty->print_cr("*********************************************************");
 549   }
 550   if (do_reduce_allocation_merges() != ReduceAllocationMerges && PrintOpto) {
 551     // Recompiling without reducing allocation merges
 552     tty->print_cr("*********************************************************");
 553     tty->print_cr("** Bailout: Recompile without reduce allocation merges **");
 554     tty->print_cr("*********************************************************");
 555   }
 556   if ((eliminate_boxing() != EliminateAutoBox) && PrintOpto) {
 557     // Recompiling without boxing elimination
 558     tty->print_cr("*********************************************************");
 559     tty->print_cr("** Bailout: Recompile without boxing elimination       **");
 560     tty->print_cr("*********************************************************");
 561   }
 562   if ((do_locks_coarsening() != EliminateLocks) && PrintOpto) {
 563     // Recompiling without locks coarsening
 564     tty->print_cr("*********************************************************");
 565     tty->print_cr("** Bailout: Recompile without locks coarsening         **");
 566     tty->print_cr("*********************************************************");
 567   }
 568   if (env()->break_at_compile()) {
 569     // Open the debugger when compiling this method.
 570     tty->print("### Breaking when compiling: ");
 571     method()->print_short_name();
 572     tty->cr();
 573     BREAKPOINT;
 574   }
 575 
 576   if( PrintOpto ) {
 577     if (is_osr_compilation()) {
 578       tty->print("[OSR]%3d", _compile_id);
 579     } else {
 580       tty->print("%3d", _compile_id);
 581     }
 582   }
 583 #endif
 584 }
 585 
 586 #ifndef PRODUCT
 587 void Compile::print_phase(const char* phase_name) {
 588   tty->print_cr("%u.\t%s", ++_phase_counter, phase_name);
 589 }
 590 
 591 void Compile::print_ideal_ir(const char* compile_phase_name) const {
 592   // keep the following output all in one block
 593   // This output goes directly to the tty, not the compiler log.
 594   // To enable tools to match it up with the compilation activity,
 595   // be sure to tag this tty output with the compile ID.
 596 
 597   // Node dumping can cause a safepoint, which can break the tty lock.
 598   // Buffer all node dumps, so that all safepoints happen before we lock.
 599   ResourceMark rm;
 600   stringStream ss;
 601 
 602   if (_output == nullptr) {
 603     ss.print_cr("AFTER: %s", compile_phase_name);
 604     // Print out all nodes in ascending order of index.
 605     // It is important that we traverse both inputs and outputs of nodes,
 606     // so that we reach all nodes that are connected to Root.
 607     root()->dump_bfs(MaxNodeLimit, nullptr, "-+S$", &ss);
 608   } else {
 609     // Dump the node blockwise if we have a scheduling
 610     _output->print_scheduling(&ss);
 611   }
 612 
 613   // Check that the lock is not broken by a safepoint.
 614   NoSafepointVerifier nsv;
 615   ttyLocker ttyl;
 616   if (xtty != nullptr) {
 617     xtty->head("ideal compile_id='%d'%s compile_phase='%s'",
 618                compile_id(),
 619                is_osr_compilation() ? " compile_kind='osr'" : "",
 620                compile_phase_name);
 621   }
 622 
 623   tty->print("%s", ss.as_string());
 624 
 625   if (xtty != nullptr) {
 626     xtty->tail("ideal");
 627   }
 628 }
 629 #endif
 630 
 631 // ============================================================================
 632 //------------------------------Compile standard-------------------------------
 633 
 634 // Compile a method.  entry_bci is -1 for normal compilations and indicates
 635 // the continuation bci for on stack replacement.
 636 
 637 
 638 Compile::Compile(ciEnv* ci_env, ciMethod* target, int osr_bci,
 639                  Options options, DirectiveSet* directive)
 640     : Phase(Compiler),
 641       _compile_id(ci_env->compile_id()),
 642       _options(options),
 643       _method(target),
 644       _entry_bci(osr_bci),
 645       _ilt(nullptr),
 646       _stub_function(nullptr),
 647       _stub_name(nullptr),
 648       _stub_id(StubId::NO_STUBID),
 649       _stub_entry_point(nullptr),
 650       _max_node_limit(MaxNodeLimit),
 651       _node_count_inlining_cutoff(NodeCountInliningCutoff),
 652       _post_loop_opts_phase(false),
 653       _merge_stores_phase(false),
 654       _allow_macro_nodes(true),
 655       _inlining_progress(false),
 656       _inlining_incrementally(false),
 657       _do_cleanup(false),
 658       _has_reserved_stack_access(target->has_reserved_stack_access()),
 659 #ifndef PRODUCT
 660       _igv_idx(0),
 661       _trace_opto_output(directive->TraceOptoOutputOption),
 662 #endif
 663       _clinit_barrier_on_entry(false),
 664       _stress_seed(0),
 665       _comp_arena(mtCompiler, Arena::Tag::tag_comp),
 666       _barrier_set_state(BarrierSet::barrier_set()->barrier_set_c2()->create_barrier_state(comp_arena())),
 667       _env(ci_env),
 668       _directive(directive),
 669       _log(ci_env->log()),
 670       _first_failure_details(nullptr),
 671       _intrinsics(comp_arena(), 0, 0, nullptr),
 672       _macro_nodes(comp_arena(), 8, 0, nullptr),
 673       _parse_predicates(comp_arena(), 8, 0, nullptr),
 674       _template_assertion_predicate_opaques(comp_arena(), 8, 0, nullptr),
 675       _expensive_nodes(comp_arena(), 8, 0, nullptr),
 676       _reachability_fences(comp_arena(), 8, 0, nullptr),
 677       _for_post_loop_igvn(comp_arena(), 8, 0, nullptr),
 678       _for_merge_stores_igvn(comp_arena(), 8, 0, nullptr),
 679       _unstable_if_traps(comp_arena(), 8, 0, nullptr),
 680       _coarsened_locks(comp_arena(), 8, 0, nullptr),
 681       _congraph(nullptr),
 682       NOT_PRODUCT(_igv_printer(nullptr) COMMA)
 683       _unique(0),
 684       _dead_node_count(0),
 685       _dead_node_list(comp_arena()),
 686       _node_arena_one(mtCompiler, Arena::Tag::tag_node),
 687       _node_arena_two(mtCompiler, Arena::Tag::tag_node),
 688       _node_arena(&_node_arena_one),
 689       _dead_path(nullptr),
 690       _mach_constant_base_node(nullptr),
 691       _Compile_types(mtCompiler, Arena::Tag::tag_type),
 692       _initial_gvn(nullptr),
 693       _igvn_worklist(nullptr),
 694       _types(nullptr),
 695       _node_hash(nullptr),
 696       _late_inlines(comp_arena(), 2, 0, nullptr),
 697       _string_late_inlines(comp_arena(), 2, 0, nullptr),
 698       _boxing_late_inlines(comp_arena(), 2, 0, nullptr),
 699       _vector_reboxing_late_inlines(comp_arena(), 2, 0, nullptr),
 700       _late_inlines_pos(0),
 701       _has_mh_late_inlines(false),
 702       _oom(false),
 703       _replay_inline_data(nullptr),
 704       _inline_printer(this),
 705       _java_calls(0),
 706       _inner_loops(0),
 707       _FIRST_STACK_mask(comp_arena()),
 708       _interpreter_frame_size(0),
 709       _regmask_arena(mtCompiler, Arena::Tag::tag_regmask),
 710       _output(nullptr)
 711 #ifndef PRODUCT
 712       ,
 713       _in_dump_cnt(0)
 714 #endif
 715 {
 716   C = this;
 717   CompileWrapper cw(this);
 718 
 719   TraceTime t1("Total compilation time", &_t_totalCompilation, CITime, CITimeVerbose);
 720   TraceTime t2(nullptr, &_t_methodCompilation, CITime, false);
 721 
 722 #if defined(SUPPORT_ASSEMBLY) || defined(SUPPORT_ABSTRACT_ASSEMBLY)
 723   bool print_opto_assembly = directive->PrintOptoAssemblyOption;
 724   // We can always print a disassembly, either abstract (hex dump) or
 725   // with the help of a suitable hsdis library. Thus, we should not
 726   // couple print_assembly and print_opto_assembly controls.
 727   // But: always print opto and regular assembly on compile command 'print'.
 728   bool print_assembly = directive->PrintAssemblyOption;
 729   set_print_assembly(print_opto_assembly || print_assembly);
 730 #else
 731   set_print_assembly(false); // must initialize.
 732 #endif
 733 
 734 #ifndef PRODUCT
 735   set_parsed_irreducible_loop(false);
 736 #endif
 737 
 738   if (directive->ReplayInlineOption) {
 739     _replay_inline_data = ciReplay::load_inline_data(method(), entry_bci(), ci_env->comp_level());
 740   }
 741   set_print_inlining(directive->PrintInliningOption || PrintOptoInlining);
 742   set_print_intrinsics(directive->PrintIntrinsicsOption);
 743   set_has_irreducible_loop(true); // conservative until build_loop_tree() reset it
 744 
 745   if (ProfileTraps) {
 746     // Make sure the method being compiled gets its own MDO,
 747     // so we can at least track the decompile_count().
 748     method()->ensure_method_data();
 749   }
 750 
 751   if (StressLCM || StressGCM || StressIGVN || StressCCP ||
 752       StressIncrementalInlining || StressMacroExpansion ||
 753       StressMacroElimination || StressUnstableIfTraps ||
 754       StressBailout || StressLoopPeeling || StressCountedLoop ||
 755       StressEliminateAllocations) {
 756     initialize_stress_seed(directive);
 757   }
 758 
 759   Init(/*do_aliasing=*/ true);
 760   set_dead_path(new DeadPathNode());
 761 
 762   print_compile_messages();
 763 
 764   _ilt = InlineTree::build_inline_tree_root();
 765 
 766   // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
 767   assert(num_alias_types() >= AliasIdxRaw, "");
 768 
 769 #define MINIMUM_NODE_HASH  1023
 770 
 771   // GVN that will be run immediately on new nodes
 772   uint estimated_size = method()->code_size()*4+64;
 773   estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
 774   _igvn_worklist = new (comp_arena()) Unique_Node_List(comp_arena());
 775   _types = new (comp_arena()) Type_Array(comp_arena());
 776   _node_hash = new (comp_arena()) NodeHash(comp_arena(), estimated_size);
 777   PhaseGVN gvn;
 778   set_initial_gvn(&gvn);
 779 
 780   { // Scope for timing the parser
 781     TracePhase tp(_t_parser);
 782 
 783     // Put top into the hash table ASAP.
 784     initial_gvn()->transform(top());
 785 
 786     // Set up tf(), start(), and find a CallGenerator.
 787     CallGenerator* cg = nullptr;
 788     if (is_osr_compilation()) {
 789       const TypeTuple *domain = StartOSRNode::osr_domain();
 790       const TypeTuple *range = TypeTuple::make_range(method()->signature());
 791       init_tf(TypeFunc::make(domain, range));
 792       StartNode* s = new StartOSRNode(root(), domain);
 793       initial_gvn()->set_type_bottom(s);
 794       verify_start(s);
 795       cg = CallGenerator::for_osr(method(), entry_bci());
 796     } else {
 797       // Normal case.
 798       init_tf(TypeFunc::make(method()));
 799       StartNode* s = new StartNode(root(), tf()->domain());
 800       initial_gvn()->set_type_bottom(s);
 801       verify_start(s);
 802       float past_uses = method()->interpreter_invocation_count();
 803       float expected_uses = past_uses;
 804       cg = CallGenerator::for_inline(method(), expected_uses);
 805     }
 806     if (failing())  return;
 807     if (cg == nullptr) {
 808       const char* reason = InlineTree::check_can_parse(method());
 809       assert(reason != nullptr, "expect reason for parse failure");
 810       stringStream ss;
 811       ss.print("cannot parse method: %s", reason);
 812       record_method_not_compilable(ss.as_string());
 813       return;
 814     }
 815 
 816     gvn.set_type(root(), root()->bottom_type());
 817 
 818     JVMState* jvms = build_start_state(start(), tf());
 819     if ((jvms = cg->generate(jvms)) == nullptr) {
 820       assert(failure_reason() != nullptr, "expect reason for parse failure");
 821       stringStream ss;
 822       ss.print("method parse failed: %s", failure_reason());
 823       record_method_not_compilable(ss.as_string() DEBUG_ONLY(COMMA true));
 824       return;
 825     }
 826     GraphKit kit(jvms);
 827 
 828     if (!kit.stopped()) {
 829       // Accept return values, and transfer control we know not where.
 830       // This is done by a special, unique ReturnNode bound to root.
 831       return_values(kit.jvms());
 832     }
 833 
 834     if (kit.has_exceptions()) {
 835       // Any exceptions that escape from this call must be rethrown
 836       // to whatever caller is dynamically above us on the stack.
 837       // This is done by a special, unique RethrowNode bound to root.
 838       rethrow_exceptions(kit.transfer_exceptions_into_jvms());
 839     }
 840 
 841     assert(IncrementalInline || (_late_inlines.length() == 0 && !has_mh_late_inlines()), "incremental inlining is off");
 842 
 843     if (_late_inlines.length() == 0 && !has_mh_late_inlines() && !failing() && has_stringbuilder()) {
 844       inline_string_calls(true);
 845     }
 846 
 847     if (failing())  return;
 848 
 849     // Remove clutter produced by parsing.
 850     if (!failing()) {
 851       ResourceMark rm;
 852       PhaseRemoveUseless pru(initial_gvn(), *igvn_worklist());
 853     }
 854   }
 855 
 856   // Note:  Large methods are capped off in do_one_bytecode().
 857   if (failing())  return;
 858 
 859   // After parsing, node notes are no longer automagic.
 860   // They must be propagated by register_new_node_with_optimizer(),
 861   // clone(), or the like.
 862   set_default_node_notes(nullptr);
 863 
 864 #ifndef PRODUCT
 865   if (should_print_igv(1)) {
 866     _igv_printer->print_inlining();
 867   }
 868 #endif
 869 
 870   if (failing())  return;
 871   NOT_PRODUCT( verify_graph_edges(); )
 872 
 873   // Now optimize
 874   Optimize();
 875   if (failing())  return;
 876   NOT_PRODUCT( verify_graph_edges(); )
 877 
 878 #ifndef PRODUCT
 879   if (should_print_ideal()) {
 880     print_ideal_ir("PrintIdeal");
 881   }
 882 #endif
 883 
 884   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 885   bs->final_refinement(this);
 886 
 887 #ifdef ASSERT
 888   bs->verify_gc_barriers(this, BarrierSetC2::BeforeCodeGen);
 889 #endif
 890 
 891   // Dump compilation data to replay it.
 892   if (directive->DumpReplayOption) {
 893     env()->dump_replay_data(_compile_id);
 894   }
 895   if (directive->DumpInlineOption && (ilt() != nullptr)) {
 896     env()->dump_inline_data(_compile_id);
 897   }
 898 
 899   // Now that we know the size of all the monitors we can add a fixed slot
 900   // for the original deopt pc.
 901   int next_slot = fixed_slots() + (sizeof(address) / VMRegImpl::stack_slot_size);
 902   set_fixed_slots(next_slot);
 903 
 904   // Compute when to use implicit null checks. Used by matching trap based
 905   // nodes and NullCheck optimization.
 906   set_allowed_deopt_reasons();
 907 
 908   // Now generate code
 909   Code_Gen();
 910 }
 911 
 912 // C2 uses runtime stubs serialized generation to initialize its static tables
 913 // shared by all compilations, like Type::_shared_type_dict.
 914 // At least one stub have to be completely generated to execute intialization
 915 // before we can skip the rest stubs generation by loading AOT cached stubs.
 916 
 917 static bool c2_do_stub_init_complete = false;
 918 
 919 //------------------------------Compile----------------------------------------
 920 // Compile a runtime stub
 921 Compile::Compile(ciEnv* ci_env,
 922                  TypeFunc_generator generator,
 923                  address stub_function,
 924                  const char* stub_name,
 925                  StubId stub_id,
 926                  int is_fancy_jump,
 927                  bool pass_tls,
 928                  bool return_pc,
 929                  DirectiveSet* directive)
 930     : Phase(Compiler),
 931       _compile_id(0),
 932       _options(Options::for_runtime_stub()),
 933       _method(nullptr),
 934       _entry_bci(InvocationEntryBci),
 935       _stub_function(stub_function),
 936       _stub_name(stub_name),
 937       _stub_id(stub_id),
 938       _stub_entry_point(nullptr),
 939       _max_node_limit(MaxNodeLimit),
 940       _node_count_inlining_cutoff(NodeCountInliningCutoff),
 941       _post_loop_opts_phase(false),
 942       _merge_stores_phase(false),
 943       _allow_macro_nodes(true),
 944       _inlining_progress(false),
 945       _inlining_incrementally(false),
 946       _has_reserved_stack_access(false),
 947 #ifndef PRODUCT
 948       _igv_idx(0),
 949       _trace_opto_output(directive->TraceOptoOutputOption),
 950 #endif
 951       _clinit_barrier_on_entry(false),
 952       _stress_seed(0),
 953       _comp_arena(mtCompiler, Arena::Tag::tag_comp),
 954       _barrier_set_state(BarrierSet::barrier_set()->barrier_set_c2()->create_barrier_state(comp_arena())),
 955       _env(ci_env),
 956       _directive(directive),
 957       _log(ci_env->log()),
 958       _first_failure_details(nullptr),
 959       _reachability_fences(comp_arena(), 8, 0, nullptr),
 960       _for_post_loop_igvn(comp_arena(), 8, 0, nullptr),
 961       _for_merge_stores_igvn(comp_arena(), 8, 0, nullptr),
 962       _congraph(nullptr),
 963       NOT_PRODUCT(_igv_printer(nullptr) COMMA)
 964       _unique(0),
 965       _dead_node_count(0),
 966       _dead_node_list(comp_arena()),
 967       _node_arena_one(mtCompiler, Arena::Tag::tag_node),
 968       _node_arena_two(mtCompiler, Arena::Tag::tag_node),
 969       _node_arena(&_node_arena_one),
 970       _dead_path(nullptr),
 971       _mach_constant_base_node(nullptr),
 972       _Compile_types(mtCompiler, Arena::Tag::tag_type),
 973       _initial_gvn(nullptr),
 974       _igvn_worklist(nullptr),
 975       _types(nullptr),
 976       _node_hash(nullptr),
 977       _has_mh_late_inlines(false),
 978       _oom(false),
 979       _replay_inline_data(nullptr),
 980       _inline_printer(this),
 981       _java_calls(0),
 982       _inner_loops(0),
 983       _FIRST_STACK_mask(comp_arena()),
 984       _interpreter_frame_size(0),
 985       _regmask_arena(mtCompiler, Arena::Tag::tag_regmask),
 986       _output(nullptr),
 987 #ifndef PRODUCT
 988       _in_dump_cnt(0),
 989 #endif
 990       _allowed_reasons(0) {
 991   C = this;
 992 
 993   // try to reuse an existing stub
 994   if (c2_do_stub_init_complete) {
 995     BlobId blob_id = StubInfo::blob(_stub_id);
 996     CodeBlob* blob = AOTCodeCache::load_code_blob(AOTCodeEntry::C2Blob, blob_id);
 997     if (blob != nullptr) {
 998       RuntimeStub* rs = blob->as_runtime_stub();
 999       _stub_entry_point = rs->entry_point();
1000       return;
1001     }
1002   }
1003 
1004   TraceTime t1(nullptr, &_t_totalCompilation, CITime, false);
1005   TraceTime t2(nullptr, &_t_stubCompilation, CITime, false);
1006 
1007 #ifndef PRODUCT
1008   set_print_assembly(PrintFrameConverterAssembly);
1009   set_parsed_irreducible_loop(false);
1010 #else
1011   set_print_assembly(false); // Must initialize.
1012 #endif
1013   set_has_irreducible_loop(false); // no loops
1014 
1015   CompileWrapper cw(this);
1016   Init(/*do_aliasing=*/ false);
1017   init_tf((*generator)());
1018 
1019   _igvn_worklist = new (comp_arena()) Unique_Node_List(comp_arena());
1020   _types = new (comp_arena()) Type_Array(comp_arena());
1021   _node_hash = new (comp_arena()) NodeHash(comp_arena(), 255);
1022 
1023   if (StressLCM || StressGCM || StressBailout) {
1024     initialize_stress_seed(directive);
1025   }
1026 
1027   {
1028     PhaseGVN gvn;
1029     set_initial_gvn(&gvn);    // not significant, but GraphKit guys use it pervasively
1030     gvn.transform(top());
1031 
1032     GraphKit kit;
1033     kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
1034   }
1035 
1036   NOT_PRODUCT( verify_graph_edges(); )
1037 
1038   Code_Gen();
1039 
1040   // First successful stub generation will set it to `true`
1041   // and it will stay `true` after that.
1042   c2_do_stub_init_complete = c2_do_stub_init_complete || (_stub_entry_point != nullptr);
1043 }
1044 
1045 Compile::~Compile() {
1046   delete _first_failure_details;
1047 };
1048 
1049 //------------------------------Init-------------------------------------------
1050 // Prepare for a single compilation
1051 void Compile::Init(bool aliasing) {
1052   _do_aliasing = aliasing;
1053   _unique  = 0;
1054   _regalloc = nullptr;
1055 
1056   _tf      = nullptr;  // filled in later
1057   _top     = nullptr;  // cached later
1058   _matcher = nullptr;  // filled in later
1059   _cfg     = nullptr;  // filled in later
1060 
1061   _node_note_array = nullptr;
1062   _default_node_notes = nullptr;
1063   DEBUG_ONLY( _modified_nodes = nullptr; ) // Used in Optimize()
1064 
1065   _immutable_memory = nullptr; // filled in at first inquiry
1066 
1067 #ifdef ASSERT
1068   _phase_optimize_finished = false;
1069   _phase_verify_ideal_loop = false;
1070   _exception_backedge = false;
1071   _type_verify = nullptr;
1072 #endif
1073 
1074   // Globally visible Nodes
1075   // First set TOP to null to give safe behavior during creation of RootNode
1076   set_cached_top_node(nullptr);
1077   set_root(new RootNode());
1078   // Now that you have a Root to point to, create the real TOP
1079   set_cached_top_node( new ConNode(Type::TOP) );
1080   set_recent_alloc(nullptr, nullptr);
1081 
1082   // Create Debug Information Recorder to record scopes, oopmaps, etc.
1083   env()->set_oop_recorder(new OopRecorder(env()->arena()));
1084   env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
1085   env()->set_dependencies(new Dependencies(env()));
1086 
1087   _fixed_slots = 0;
1088   set_has_split_ifs(false);
1089   set_has_loops(false); // first approximation
1090   set_has_stringbuilder(false);
1091   set_has_boxed_value(false);
1092   _trap_can_recompile = false;  // no traps emitted yet
1093   _major_progress = true; // start out assuming good things will happen
1094   set_has_unsafe_access(false);
1095   set_max_vector_size(0);
1096   set_clear_upper_avx(false);  //false as default for clear upper bits of ymm registers
1097   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
1098   set_decompile_count(0);
1099 
1100 #ifndef PRODUCT
1101   _phase_counter = 0;
1102   Copy::zero_to_bytes(_igv_phase_iter, sizeof(_igv_phase_iter));
1103 #endif
1104 
1105   set_do_freq_based_layout(_directive->BlockLayoutByFrequencyOption);
1106   _loop_opts_cnt = LoopOptsCount;
1107   set_do_inlining(Inline);
1108   set_max_inline_size(MaxInlineSize);
1109   set_freq_inline_size(FreqInlineSize);
1110   set_do_scheduling(OptoScheduling);
1111 
1112   set_do_vector_loop(false);
1113   set_has_monitors(false);
1114   set_has_scoped_access(false);
1115 
1116   if (AllowVectorizeOnDemand) {
1117     if (has_method() && _directive->VectorizeOption) {
1118       set_do_vector_loop(true);
1119       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());})
1120     } else if (has_method() && method()->name() != nullptr &&
1121                method()->intrinsic_id() == vmIntrinsics::_forEachRemaining) {
1122       set_do_vector_loop(true);
1123     }
1124   }
1125   set_use_cmove(UseCMoveUnconditionally /* || do_vector_loop()*/); //TODO: consider do_vector_loop() mandate use_cmove unconditionally
1126   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());})
1127 
1128   _max_node_limit = _directive->MaxNodeLimitOption;
1129 
1130   if (VM_Version::supports_fast_class_init_checks() && has_method() && !is_osr_compilation() && method()->needs_clinit_barrier()) {
1131     set_clinit_barrier_on_entry(true);
1132   }
1133   if (debug_info()->recording_non_safepoints()) {
1134     set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
1135                         (comp_arena(), 8, 0, nullptr));
1136     set_default_node_notes(Node_Notes::make(this));
1137   }
1138 
1139   const int grow_ats = 16;
1140   _max_alias_types = grow_ats;
1141   _alias_types   = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
1142   AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType,  grow_ats);
1143   Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
1144   {
1145     for (int i = 0; i < grow_ats; i++)  _alias_types[i] = &ats[i];
1146   }
1147   // Initialize the first few types.
1148   _alias_types[AliasIdxTop]->Init(AliasIdxTop, nullptr);
1149   _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
1150   _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
1151   _num_alias_types = AliasIdxRaw+1;
1152   // Zero out the alias type cache.
1153   Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
1154   // A null adr_type hits in the cache right away.  Preload the right answer.
1155   probe_alias_cache(nullptr)->_index = AliasIdxTop;
1156 }
1157 
1158 #ifdef ASSERT
1159 // Verify that the current StartNode is valid.
1160 void Compile::verify_start(StartNode* s) const {
1161   assert(failing_internal() || s == start(), "should be StartNode");
1162 }
1163 #endif
1164 
1165 /**
1166  * Return the 'StartNode'. We must not have a pending failure, since the ideal graph
1167  * can be in an inconsistent state, i.e., we can get segmentation faults when traversing
1168  * the ideal graph.
1169  */
1170 StartNode* Compile::start() const {
1171   assert (!failing_internal() || C->failure_is_artificial(), "Must not have pending failure. Reason is: %s", failure_reason());
1172   for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
1173     Node* start = root()->fast_out(i);
1174     if (start->is_Start()) {
1175       return start->as_Start();
1176     }
1177   }
1178   fatal("Did not find Start node!");
1179   return nullptr;
1180 }
1181 
1182 //-------------------------------immutable_memory-------------------------------------
1183 // Access immutable memory
1184 Node* Compile::immutable_memory() {
1185   if (_immutable_memory != nullptr) {
1186     return _immutable_memory;
1187   }
1188   StartNode* s = start();
1189   for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
1190     Node *p = s->fast_out(i);
1191     if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
1192       _immutable_memory = p;
1193       return _immutable_memory;
1194     }
1195   }
1196   ShouldNotReachHere();
1197   return nullptr;
1198 }
1199 
1200 //----------------------set_cached_top_node------------------------------------
1201 // Install the cached top node, and make sure Node::is_top works correctly.
1202 void Compile::set_cached_top_node(Node* tn) {
1203   if (tn != nullptr)  verify_top(tn);
1204   Node* old_top = _top;
1205   _top = tn;
1206   // Calling Node::setup_is_top allows the nodes the chance to adjust
1207   // their _out arrays.
1208   if (_top != nullptr)     _top->setup_is_top();
1209   if (old_top != nullptr)  old_top->setup_is_top();
1210   assert(_top == nullptr || top()->is_top(), "");
1211 }
1212 
1213 #ifdef ASSERT
1214 uint Compile::count_live_nodes_by_graph_walk() {
1215   Unique_Node_List useful(comp_arena());
1216   // Get useful node list by walking the graph.
1217   identify_useful_nodes(useful);
1218   return useful.size();
1219 }
1220 
1221 void Compile::print_missing_nodes() {
1222 
1223   // Return if CompileLog is null and PrintIdealNodeCount is false.
1224   if ((_log == nullptr) && (! PrintIdealNodeCount)) {
1225     return;
1226   }
1227 
1228   // This is an expensive function. It is executed only when the user
1229   // specifies VerifyIdealNodeCount option or otherwise knows the
1230   // additional work that needs to be done to identify reachable nodes
1231   // by walking the flow graph and find the missing ones using
1232   // _dead_node_list.
1233 
1234   Unique_Node_List useful(comp_arena());
1235   // Get useful node list by walking the graph.
1236   identify_useful_nodes(useful);
1237 
1238   uint l_nodes = C->live_nodes();
1239   uint l_nodes_by_walk = useful.size();
1240 
1241   if (l_nodes != l_nodes_by_walk) {
1242     if (_log != nullptr) {
1243       _log->begin_head("mismatched_nodes count='%d'", abs((int) (l_nodes - l_nodes_by_walk)));
1244       _log->stamp();
1245       _log->end_head();
1246     }
1247     VectorSet& useful_member_set = useful.member_set();
1248     int last_idx = l_nodes_by_walk;
1249     for (int i = 0; i < last_idx; i++) {
1250       if (useful_member_set.test(i)) {
1251         if (_dead_node_list.test(i)) {
1252           if (_log != nullptr) {
1253             _log->elem("mismatched_node_info node_idx='%d' type='both live and dead'", i);
1254           }
1255           if (PrintIdealNodeCount) {
1256             // Print the log message to tty
1257               tty->print_cr("mismatched_node idx='%d' both live and dead'", i);
1258               useful.at(i)->dump();
1259           }
1260         }
1261       }
1262       else if (! _dead_node_list.test(i)) {
1263         if (_log != nullptr) {
1264           _log->elem("mismatched_node_info node_idx='%d' type='neither live nor dead'", i);
1265         }
1266         if (PrintIdealNodeCount) {
1267           // Print the log message to tty
1268           tty->print_cr("mismatched_node idx='%d' type='neither live nor dead'", i);
1269         }
1270       }
1271     }
1272     if (_log != nullptr) {
1273       _log->tail("mismatched_nodes");
1274     }
1275   }
1276 }
1277 void Compile::record_modified_node(Node* n) {
1278   if (_modified_nodes != nullptr && !_inlining_incrementally && !n->is_Con()) {
1279     _modified_nodes->push(n);
1280   }
1281 }
1282 
1283 void Compile::remove_modified_node(Node* n) {
1284   if (_modified_nodes != nullptr) {
1285     _modified_nodes->remove(n);
1286   }
1287 }
1288 #endif
1289 
1290 #ifndef PRODUCT
1291 void Compile::verify_top(Node* tn) const {
1292   if (tn != nullptr) {
1293     assert(tn->is_Con(), "top node must be a constant");
1294     assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
1295     assert(tn->in(0) != nullptr, "must have live top node");
1296   }
1297 }
1298 #endif
1299 
1300 
1301 ///-------------------Managing Per-Node Debug & Profile Info-------------------
1302 
1303 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
1304   guarantee(arr != nullptr, "");
1305   int num_blocks = arr->length();
1306   if (grow_by < num_blocks)  grow_by = num_blocks;
1307   int num_notes = grow_by * _node_notes_block_size;
1308   Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
1309   Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
1310   while (num_notes > 0) {
1311     arr->append(notes);
1312     notes     += _node_notes_block_size;
1313     num_notes -= _node_notes_block_size;
1314   }
1315   assert(num_notes == 0, "exact multiple, please");
1316 }
1317 
1318 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
1319   if (source == nullptr || dest == nullptr)  return false;
1320 
1321   if (dest->is_Con())
1322     return false;               // Do not push debug info onto constants.
1323 
1324 #ifdef ASSERT
1325   // Leave a bread crumb trail pointing to the original node:
1326   if (dest != nullptr && dest != source && dest->debug_orig() == nullptr) {
1327     dest->set_debug_orig(source);
1328   }
1329 #endif
1330 
1331   if (node_note_array() == nullptr)
1332     return false;               // Not collecting any notes now.
1333 
1334   // This is a copy onto a pre-existing node, which may already have notes.
1335   // If both nodes have notes, do not overwrite any pre-existing notes.
1336   Node_Notes* source_notes = node_notes_at(source->_idx);
1337   if (source_notes == nullptr || source_notes->is_clear())  return false;
1338   Node_Notes* dest_notes   = node_notes_at(dest->_idx);
1339   if (dest_notes == nullptr || dest_notes->is_clear()) {
1340     return set_node_notes_at(dest->_idx, source_notes);
1341   }
1342 
1343   Node_Notes merged_notes = (*source_notes);
1344   // The order of operations here ensures that dest notes will win...
1345   merged_notes.update_from(dest_notes);
1346   return set_node_notes_at(dest->_idx, &merged_notes);
1347 }
1348 
1349 
1350 //--------------------------allow_range_check_smearing-------------------------
1351 // Gating condition for coalescing similar range checks.
1352 // Sometimes we try 'speculatively' replacing a series of a range checks by a
1353 // single covering check that is at least as strong as any of them.
1354 // If the optimization succeeds, the simplified (strengthened) range check
1355 // will always succeed.  If it fails, we will deopt, and then give up
1356 // on the optimization.
1357 bool Compile::allow_range_check_smearing() const {
1358   // If this method has already thrown a range-check,
1359   // assume it was because we already tried range smearing
1360   // and it failed.
1361   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
1362   return !already_trapped;
1363 }
1364 
1365 
1366 //------------------------------flatten_alias_type-----------------------------
1367 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
1368   assert(do_aliasing(), "Aliasing should be enabled");
1369   int offset = tj->offset();
1370   TypePtr::PTR ptr = tj->ptr();
1371 
1372   // Known instance (scalarizable allocation) alias only with itself.
1373   bool is_known_inst = tj->isa_oopptr() != nullptr &&
1374                        tj->is_oopptr()->is_known_instance();
1375 
1376   // Process weird unsafe references.
1377   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
1378     assert(InlineUnsafeOps || StressReflectiveCode, "indeterminate pointers come only from unsafe ops");
1379     assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
1380     tj = TypeOopPtr::BOTTOM;
1381     ptr = tj->ptr();
1382     offset = tj->offset();
1383   }
1384 
1385   // Array pointers need some flattening
1386   const TypeAryPtr* ta = tj->isa_aryptr();
1387   if (ta && ta->is_stable()) {
1388     // Erase stability property for alias analysis.
1389     tj = ta = ta->cast_to_stable(false);
1390   }
1391   if( ta && is_known_inst ) {
1392     if ( offset != Type::OffsetBot &&
1393          offset > arrayOopDesc::length_offset_in_bytes() ) {
1394       offset = Type::OffsetBot; // Flatten constant access into array body only
1395       tj = ta = ta->
1396               remove_speculative()->
1397               cast_to_ptr_type(ptr)->
1398               with_offset(offset);
1399     }
1400   } else if (ta != nullptr) {
1401     // Common slices
1402     if (offset == arrayOopDesc::length_offset_in_bytes()) {
1403       return TypeAryPtr::RANGE;
1404     } else if (offset == oopDesc::klass_offset_in_bytes()) {
1405       return TypeInstPtr::KLASS;
1406     } else if (offset == oopDesc::mark_offset_in_bytes()) {
1407       return TypeInstPtr::MARK;
1408     }
1409 
1410     // Remove size and stability
1411     const TypeAry* normalized_ary = TypeAry::make(ta->elem(), TypeInt::POS, false);
1412     // Remove ptr, const_oop, and offset
1413     if (ta->elem() == Type::BOTTOM) {
1414       // Bottom array (meet of int[] and byte[] for example), accesses to it will be done with
1415       // Unsafe. This should alias with all arrays. For now just leave it as it is (this is
1416       // incorrect, see JDK-8331133).
1417       tj = ta = TypeAryPtr::make(TypePtr::BotPTR, nullptr, normalized_ary, nullptr, false, Type::OffsetBot);
1418     } else if (ta->elem()->make_oopptr() != nullptr) {
1419       // Object arrays, all of them share the same slice
1420       const TypeAry* tary = TypeAry::make(TypeInstPtr::BOTTOM, TypeInt::POS, false);
1421       tj = ta = TypeAryPtr::make(TypePtr::BotPTR, nullptr, tary, nullptr, false, Type::OffsetBot);
1422     } else {
1423       // Primitive arrays
1424       tj = ta = TypeAryPtr::make(TypePtr::BotPTR, nullptr, normalized_ary, ta->exact_klass(), true, Type::OffsetBot);
1425     }
1426 
1427     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
1428     // cannot be distinguished by bytecode alone.
1429     if (ta->elem() == TypeInt::BOOL) {
1430       tj = ta = TypeAryPtr::BYTES;
1431     }
1432   }
1433 
1434   // Oop pointers need some flattening
1435   const TypeInstPtr *to = tj->isa_instptr();
1436   if (to && to != TypeOopPtr::BOTTOM) {
1437     ciInstanceKlass* ik = to->instance_klass();
1438     if( ptr == TypePtr::Constant ) {
1439       if (ik != ciEnv::current()->Class_klass() ||
1440           offset < ik->layout_helper_size_in_bytes()) {
1441         // No constant oop pointers (such as Strings); they alias with
1442         // unknown strings.
1443         assert(!is_known_inst, "not scalarizable allocation");
1444         tj = to = to->
1445                 cast_to_instance_id(TypeOopPtr::InstanceBot)->
1446                 remove_speculative()->
1447                 cast_to_ptr_type(TypePtr::BotPTR)->
1448                 cast_to_exactness(false);
1449       }
1450     } else if( is_known_inst ) {
1451       tj = to; // Keep NotNull and klass_is_exact for instance type
1452     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
1453       // During the 2nd round of IterGVN, NotNull castings are removed.
1454       // Make sure the Bottom and NotNull variants alias the same.
1455       // Also, make sure exact and non-exact variants alias the same.
1456       tj = to = to->
1457               remove_speculative()->
1458               cast_to_instance_id(TypeOopPtr::InstanceBot)->
1459               cast_to_ptr_type(TypePtr::BotPTR)->
1460               cast_to_exactness(false);
1461     }
1462     if (to->speculative() != nullptr) {
1463       tj = to = to->remove_speculative();
1464     }
1465     // Canonicalize the holder of this field
1466     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
1467       // First handle header references such as a LoadKlassNode, even if the
1468       // object's klass is unloaded at compile time (4965979).
1469       if (!is_known_inst) { // Do it only for non-instance types
1470         tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, nullptr, offset);
1471       }
1472     } else if (offset < 0 || offset >= ik->layout_helper_size_in_bytes()) {
1473       // Static fields are in the space above the normal instance
1474       // fields in the java.lang.Class instance.
1475       if (ik != ciEnv::current()->Class_klass()) {
1476         to = nullptr;
1477         tj = TypeOopPtr::BOTTOM;
1478         offset = tj->offset();
1479       }
1480     } else {
1481       ciInstanceKlass *canonical_holder = ik->get_canonical_holder(offset);
1482       assert(offset < canonical_holder->layout_helper_size_in_bytes(), "");
1483       assert(tj->offset() == offset, "no change to offset expected");
1484       bool xk = to->klass_is_exact();
1485       int instance_id = to->instance_id();
1486 
1487       // If the input type's class is the holder: if exact, the type only includes interfaces implemented by the holder
1488       // but if not exact, it may include extra interfaces: build new type from the holder class to make sure only
1489       // its interfaces are included.
1490       if (xk && ik->equals(canonical_holder)) {
1491         assert(tj == TypeInstPtr::make(to->ptr(), canonical_holder, is_known_inst, nullptr, offset, instance_id), "exact type should be canonical type");
1492       } else {
1493         assert(xk || !is_known_inst, "Known instance should be exact type");
1494         tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, is_known_inst, nullptr, offset, instance_id);
1495       }
1496     }
1497   }
1498 
1499   // Klass pointers to object array klasses need some flattening
1500   const TypeKlassPtr *tk = tj->isa_klassptr();
1501   if( tk ) {
1502     // If we are referencing a field within a Klass, we need
1503     // to assume the worst case of an Object.  Both exact and
1504     // inexact types must flatten to the same alias class so
1505     // use NotNull as the PTR.
1506     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
1507       tj = tk = TypeInstKlassPtr::make(TypePtr::NotNull,
1508                                        env()->Object_klass(),
1509                                        offset);
1510     }
1511 
1512     if (tk->isa_aryklassptr() && tk->is_aryklassptr()->elem()->isa_klassptr()) {
1513       ciKlass* k = ciObjArrayKlass::make(env()->Object_klass());
1514       if (!k || !k->is_loaded()) {                  // Only fails for some -Xcomp runs
1515         tj = tk = TypeInstKlassPtr::make(TypePtr::NotNull, env()->Object_klass(), offset);
1516       } else {
1517         tj = tk = TypeAryKlassPtr::make(TypePtr::NotNull, tk->is_aryklassptr()->elem(), k, offset);
1518       }
1519     }
1520 
1521     // Check for precise loads from the primary supertype array and force them
1522     // to the supertype cache alias index.  Check for generic array loads from
1523     // the primary supertype array and also force them to the supertype cache
1524     // alias index.  Since the same load can reach both, we need to merge
1525     // these 2 disparate memories into the same alias class.  Since the
1526     // primary supertype array is read-only, there's no chance of confusion
1527     // where we bypass an array load and an array store.
1528     int primary_supers_offset = in_bytes(Klass::primary_supers_offset());
1529     if (offset == Type::OffsetBot ||
1530         (offset >= primary_supers_offset &&
1531          offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
1532         offset == (int)in_bytes(Klass::secondary_super_cache_offset())) {
1533       offset = in_bytes(Klass::secondary_super_cache_offset());
1534       tj = tk = tk->with_offset(offset);
1535     }
1536   }
1537 
1538   // Flatten all Raw pointers together.
1539   if (tj->base() == Type::RawPtr)
1540     tj = TypeRawPtr::BOTTOM;
1541 
1542   if (tj->base() == Type::AnyPtr)
1543     tj = TypePtr::BOTTOM;      // An error, which the caller must check for.
1544 
1545   offset = tj->offset();
1546   assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
1547 
1548   assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
1549           (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
1550           (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
1551           (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
1552           (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1553           (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1554           (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr),
1555           "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
1556   assert( tj->ptr() != TypePtr::TopPTR &&
1557           tj->ptr() != TypePtr::AnyNull &&
1558           tj->ptr() != TypePtr::Null, "No imprecise addresses" );
1559 //    assert( tj->ptr() != TypePtr::Constant ||
1560 //            tj->base() == Type::RawPtr ||
1561 //            tj->base() == Type::KlassPtr, "No constant oop addresses" );
1562 
1563   return tj;
1564 }
1565 
1566 void Compile::AliasType::Init(int i, const TypePtr* at) {
1567   assert(AliasIdxTop <= i && i < Compile::current()->_max_alias_types, "Invalid alias index");
1568   _index = i;
1569   _adr_type = at;
1570   _field = nullptr;
1571   _element = nullptr;
1572   _is_rewritable = true; // default
1573   const TypeOopPtr *atoop = (at != nullptr) ? at->isa_oopptr() : nullptr;
1574   if (atoop != nullptr && atoop->is_known_instance()) {
1575     const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
1576     _general_index = Compile::current()->get_alias_index(gt);
1577   } else {
1578     _general_index = 0;
1579   }
1580 }
1581 
1582 BasicType Compile::AliasType::basic_type() const {
1583   if (element() != nullptr) {
1584     const Type* element = adr_type()->is_aryptr()->elem();
1585     return element->isa_narrowoop() ? T_OBJECT : element->array_element_basic_type();
1586   } if (field() != nullptr) {
1587     return field()->layout_type();
1588   } else {
1589     return T_ILLEGAL; // unknown
1590   }
1591 }
1592 
1593 //---------------------------------print_on------------------------------------
1594 #ifndef PRODUCT
1595 void Compile::AliasType::print_on(outputStream* st) {
1596   if (index() < 10)
1597         st->print("@ <%d> ", index());
1598   else  st->print("@ <%d>",  index());
1599   st->print(is_rewritable() ? "   " : " RO");
1600   int offset = adr_type()->offset();
1601   if (offset == Type::OffsetBot)
1602         st->print(" +any");
1603   else  st->print(" +%-3d", offset);
1604   st->print(" in ");
1605   adr_type()->dump_on(st);
1606   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
1607   if (field() != nullptr && tjp) {
1608     if (tjp->is_instptr()->instance_klass()  != field()->holder() ||
1609         tjp->offset() != field()->offset_in_bytes()) {
1610       st->print(" != ");
1611       field()->print();
1612       st->print(" ***");
1613     }
1614   }
1615 }
1616 
1617 void print_alias_types() {
1618   Compile* C = Compile::current();
1619   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
1620   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
1621     C->alias_type(idx)->print_on(tty);
1622     tty->cr();
1623   }
1624 }
1625 #endif
1626 
1627 
1628 //----------------------------probe_alias_cache--------------------------------
1629 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
1630   intptr_t key = (intptr_t) adr_type;
1631   key ^= key >> logAliasCacheSize;
1632   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
1633 }
1634 
1635 
1636 //-----------------------------grow_alias_types--------------------------------
1637 void Compile::grow_alias_types() {
1638   const int old_ats  = _max_alias_types; // how many before?
1639   const int new_ats  = old_ats;          // how many more?
1640   const int grow_ats = old_ats+new_ats;  // how many now?
1641   _max_alias_types = grow_ats;
1642   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), _alias_types, old_ats, grow_ats);
1643   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
1644   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
1645   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
1646 }
1647 
1648 
1649 //--------------------------------find_alias_type------------------------------
1650 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field) {
1651   if (!do_aliasing()) {
1652     return alias_type(AliasIdxBot);
1653   }
1654 
1655   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1656   if (ace->_adr_type == adr_type) {
1657     return alias_type(ace->_index);
1658   }
1659 
1660   // Handle special cases.
1661   if (adr_type == nullptr)          return alias_type(AliasIdxTop);
1662   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
1663 
1664   // Do it the slow way.
1665   const TypePtr* flat = flatten_alias_type(adr_type);
1666 
1667 #ifdef ASSERT
1668   {
1669     ResourceMark rm;
1670     assert(flat == flatten_alias_type(flat), "not idempotent: adr_type = %s; flat = %s => %s",
1671            Type::str(adr_type), Type::str(flat), Type::str(flatten_alias_type(flat)));
1672     assert(flat != TypePtr::BOTTOM, "cannot alias-analyze an untyped ptr: adr_type = %s",
1673            Type::str(adr_type));
1674     if (flat->isa_oopptr() && !flat->isa_klassptr()) {
1675       const TypeOopPtr* foop = flat->is_oopptr();
1676       // Scalarizable allocations have exact klass always.
1677       bool exact = !foop->klass_is_exact() || foop->is_known_instance();
1678       const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
1679       assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type: foop = %s; xoop = %s",
1680              Type::str(foop), Type::str(xoop));
1681     }
1682   }
1683 #endif
1684 
1685   int idx = AliasIdxTop;
1686   for (int i = 0; i < num_alias_types(); i++) {
1687     if (alias_type(i)->adr_type() == flat) {
1688       idx = i;
1689       break;
1690     }
1691   }
1692 
1693   if (idx == AliasIdxTop) {
1694     if (no_create)  return nullptr;
1695     // Grow the array if necessary.
1696     if (_num_alias_types == _max_alias_types)  grow_alias_types();
1697     // Add a new alias type.
1698     idx = _num_alias_types++;
1699     _alias_types[idx]->Init(idx, flat);
1700     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
1701     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
1702     if (flat->isa_instptr()) {
1703       if (flat->offset() == java_lang_Class::klass_offset()
1704           && flat->is_instptr()->instance_klass() == env()->Class_klass())
1705         alias_type(idx)->set_rewritable(false);
1706     }
1707     if (flat->isa_aryptr()) {
1708 #ifdef ASSERT
1709       const int header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1710       // (T_BYTE has the weakest alignment and size restrictions...)
1711       assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
1712 #endif
1713       if (flat->offset() == TypePtr::OffsetBot) {
1714         alias_type(idx)->set_element(flat->is_aryptr()->elem());
1715       }
1716     }
1717     if (flat->isa_klassptr()) {
1718       if (UseCompactObjectHeaders) {
1719         if (flat->offset() == in_bytes(Klass::prototype_header_offset()))
1720           alias_type(idx)->set_rewritable(false);
1721       }
1722       if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
1723         alias_type(idx)->set_rewritable(false);
1724       if (flat->offset() == in_bytes(Klass::misc_flags_offset()))
1725         alias_type(idx)->set_rewritable(false);
1726       if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
1727         alias_type(idx)->set_rewritable(false);
1728       if (flat->offset() == in_bytes(Klass::secondary_super_cache_offset()))
1729         alias_type(idx)->set_rewritable(false);
1730     }
1731 
1732     if (flat->isa_instklassptr()) {
1733       if (flat->offset() == in_bytes(InstanceKlass::access_flags_offset())) {
1734         alias_type(idx)->set_rewritable(false);
1735       }
1736     }
1737     // %%% (We would like to finalize JavaThread::threadObj_offset(),
1738     // but the base pointer type is not distinctive enough to identify
1739     // references into JavaThread.)
1740 
1741     // Check for final fields.
1742     const TypeInstPtr* tinst = flat->isa_instptr();
1743     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
1744       ciField* field;
1745       if (tinst->const_oop() != nullptr &&
1746           tinst->instance_klass() == ciEnv::current()->Class_klass() &&
1747           tinst->offset() >= (tinst->instance_klass()->layout_helper_size_in_bytes())) {
1748         // static field
1749         ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
1750         field = k->get_field_by_offset(tinst->offset(), true);
1751       } else {
1752         ciInstanceKlass *k = tinst->instance_klass();
1753         field = k->get_field_by_offset(tinst->offset(), false);
1754       }
1755       assert(field == nullptr ||
1756              original_field == nullptr ||
1757              (field->holder() == original_field->holder() &&
1758               field->offset_in_bytes() == original_field->offset_in_bytes() &&
1759               field->is_static() == original_field->is_static()), "wrong field?");
1760       // Set field() and is_rewritable() attributes.
1761       if (field != nullptr)  alias_type(idx)->set_field(field);
1762     }
1763   }
1764 
1765   // Fill the cache for next time.
1766   ace->_adr_type = adr_type;
1767   ace->_index    = idx;
1768   assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
1769 
1770   // Might as well try to fill the cache for the flattened version, too.
1771   AliasCacheEntry* face = probe_alias_cache(flat);
1772   if (face->_adr_type == nullptr) {
1773     face->_adr_type = flat;
1774     face->_index    = idx;
1775     assert(alias_type(flat) == alias_type(idx), "flat type must work too");
1776   }
1777 
1778   return alias_type(idx);
1779 }
1780 
1781 
1782 Compile::AliasType* Compile::alias_type(ciField* field) {
1783   const TypeOopPtr* t;
1784   if (field->is_static())
1785     t = TypeInstPtr::make(field->holder()->java_mirror());
1786   else
1787     t = TypeOopPtr::make_from_klass_raw(field->holder());
1788   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);
1789   assert((field->is_final() || field->is_stable()) == !atp->is_rewritable(), "must get the rewritable bits correct");
1790   return atp;
1791 }
1792 
1793 
1794 //------------------------------have_alias_type--------------------------------
1795 bool Compile::have_alias_type(const TypePtr* adr_type) {
1796   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1797   if (ace->_adr_type == adr_type) {
1798     return true;
1799   }
1800 
1801   // Handle special cases.
1802   if (adr_type == nullptr)             return true;
1803   if (adr_type == TypePtr::BOTTOM)  return true;
1804 
1805   return find_alias_type(adr_type, true, nullptr) != nullptr;
1806 }
1807 
1808 //-----------------------------must_alias--------------------------------------
1809 // True if all values of the given address type are in the given alias category.
1810 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
1811   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1812   if (adr_type == nullptr)              return true;  // null serves as TypePtr::TOP
1813   if (alias_idx == AliasIdxTop)         return false; // the empty category
1814   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
1815 
1816   // the only remaining possible overlap is identity
1817   int adr_idx = get_alias_index(adr_type);
1818   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1819   assert(adr_idx == alias_idx ||
1820          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
1821           && adr_type                       != TypeOopPtr::BOTTOM),
1822          "should not be testing for overlap with an unsafe pointer");
1823   return adr_idx == alias_idx;
1824 }
1825 
1826 //------------------------------can_alias--------------------------------------
1827 // True if any values of the given address type are in the given alias category.
1828 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
1829   if (alias_idx == AliasIdxTop)         return false; // the empty category
1830   if (adr_type == nullptr)              return false; // null serves as TypePtr::TOP
1831   // Known instance doesn't alias with bottom memory
1832   if (alias_idx == AliasIdxBot)         return !adr_type->is_known_instance();                   // the universal category
1833   if (adr_type->base() == Type::AnyPtr) return !C->get_adr_type(alias_idx)->is_known_instance(); // TypePtr::BOTTOM or its twins
1834 
1835   // the only remaining possible overlap is identity
1836   int adr_idx = get_alias_index(adr_type);
1837   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1838   return adr_idx == alias_idx;
1839 }
1840 
1841 // Mark all ParsePredicateNodes as useless. They will later be removed from the graph in IGVN together with their
1842 // uncommon traps if no Runtime Predicates were created from the Parse Predicates.
1843 void Compile::mark_parse_predicate_nodes_useless(PhaseIterGVN& igvn) {
1844   if (parse_predicate_count() == 0) {
1845     return;
1846   }
1847   for (int i = 0; i < parse_predicate_count(); i++) {
1848     ParsePredicateNode* parse_predicate = _parse_predicates.at(i);
1849     parse_predicate->mark_useless(igvn);
1850   }
1851   _parse_predicates.clear();
1852 }
1853 
1854 void Compile::record_for_post_loop_opts_igvn(Node* n) {
1855   if (!n->for_post_loop_opts_igvn()) {
1856     assert(!_for_post_loop_igvn.contains(n), "duplicate");
1857     n->add_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
1858     _for_post_loop_igvn.append(n);
1859   }
1860 }
1861 
1862 void Compile::remove_from_post_loop_opts_igvn(Node* n) {
1863   n->remove_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
1864   _for_post_loop_igvn.remove(n);
1865 }
1866 
1867 void Compile::process_for_post_loop_opts_igvn(PhaseIterGVN& igvn) {
1868   // Verify that all previous optimizations produced a valid graph
1869   // at least to this point, even if no loop optimizations were done.
1870   PhaseIdealLoop::verify(igvn);
1871 
1872   if (_print_phase_loop_opts) {
1873     print_method(PHASE_AFTER_LOOP_OPTS, 2);
1874   }
1875   C->set_post_loop_opts_phase(); // no more loop opts allowed
1876 
1877   assert(!C->major_progress(), "not cleared");
1878 
1879   if (_for_post_loop_igvn.length() > 0) {
1880     while (_for_post_loop_igvn.length() > 0) {
1881       Node* n = _for_post_loop_igvn.pop();
1882       n->remove_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
1883       igvn._worklist.push(n);
1884     }
1885     igvn.optimize();
1886     if (failing()) return;
1887     assert(_for_post_loop_igvn.length() == 0, "no more delayed nodes allowed");
1888     assert(C->parse_predicate_count() == 0, "all parse predicates should have been removed now");
1889 
1890     // Sometimes IGVN sets major progress (e.g., when processing loop nodes).
1891     if (C->major_progress()) {
1892       C->clear_major_progress(); // ensure that major progress is now clear
1893     }
1894   }
1895 }
1896 
1897 void Compile::record_for_merge_stores_igvn(Node* n) {
1898   if (!n->for_merge_stores_igvn()) {
1899     assert(!_for_merge_stores_igvn.contains(n), "duplicate");
1900     n->add_flag(Node::NodeFlags::Flag_for_merge_stores_igvn);
1901     _for_merge_stores_igvn.append(n);
1902   }
1903 }
1904 
1905 void Compile::remove_from_merge_stores_igvn(Node* n) {
1906   n->remove_flag(Node::NodeFlags::Flag_for_merge_stores_igvn);
1907   _for_merge_stores_igvn.remove(n);
1908 }
1909 
1910 // We need to wait with merging stores until RangeCheck smearing has removed the RangeChecks during
1911 // the post loops IGVN phase. If we do it earlier, then there may still be some RangeChecks between
1912 // the stores, and we merge the wrong sequence of stores.
1913 // Example:
1914 //   StoreI RangeCheck StoreI StoreI RangeCheck StoreI
1915 // Apply MergeStores:
1916 //   StoreI RangeCheck [   StoreL  ] RangeCheck StoreI
1917 // Remove more RangeChecks:
1918 //   StoreI            [   StoreL  ]            StoreI
1919 // But now it would have been better to do this instead:
1920 //   [         StoreL       ] [       StoreL         ]
1921 //
1922 // Note: we allow stores to merge in this dedicated IGVN round, and any later IGVN round,
1923 //       since we never unset _merge_stores_phase.
1924 void Compile::process_for_merge_stores_igvn(PhaseIterGVN& igvn) {
1925   C->set_merge_stores_phase();
1926 
1927   if (_for_merge_stores_igvn.length() > 0) {
1928     while (_for_merge_stores_igvn.length() > 0) {
1929       Node* n = _for_merge_stores_igvn.pop();
1930       n->remove_flag(Node::NodeFlags::Flag_for_merge_stores_igvn);
1931       igvn._worklist.push(n);
1932     }
1933     igvn.optimize();
1934     if (failing()) return;
1935     assert(_for_merge_stores_igvn.length() == 0, "no more delayed nodes allowed");
1936     print_method(PHASE_AFTER_MERGE_STORES, 3);
1937   }
1938 }
1939 
1940 void Compile::record_unstable_if_trap(UnstableIfTrap* trap) {
1941   if (OptimizeUnstableIf) {
1942     _unstable_if_traps.append(trap);
1943   }
1944 }
1945 
1946 void Compile::remove_useless_unstable_if_traps(Unique_Node_List& useful) {
1947   for (int i = _unstable_if_traps.length() - 1; i >= 0; i--) {
1948     UnstableIfTrap* trap = _unstable_if_traps.at(i);
1949     Node* n = trap->uncommon_trap();
1950     if (!useful.member(n)) {
1951       _unstable_if_traps.delete_at(i); // replaces i-th with last element which is known to be useful (already processed)
1952     }
1953   }
1954 }
1955 
1956 // Remove the unstable if trap associated with 'unc' from candidates. It is either dead
1957 // or fold-compares case. Return true if succeed or not found.
1958 //
1959 // In rare cases, the found trap has been processed. It is too late to delete it. Return
1960 // false and ask fold-compares to yield.
1961 //
1962 // 'fold-compares' may use the uncommon_trap of the dominating IfNode to cover the fused
1963 // IfNode. This breaks the unstable_if trap invariant: control takes the unstable path
1964 // when deoptimization does happen.
1965 bool Compile::remove_unstable_if_trap(CallStaticJavaNode* unc, bool yield) {
1966   for (int i = 0; i < _unstable_if_traps.length(); ++i) {
1967     UnstableIfTrap* trap = _unstable_if_traps.at(i);
1968     if (trap->uncommon_trap() == unc) {
1969       if (yield && trap->modified()) {
1970         return false;
1971       }
1972       _unstable_if_traps.delete_at(i);
1973       break;
1974     }
1975   }
1976   return true;
1977 }
1978 
1979 // Re-calculate unstable_if traps with the liveness of next_bci, which points to the unlikely path.
1980 // It needs to be done after igvn because fold-compares may fuse uncommon_traps and before renumbering.
1981 void Compile::process_for_unstable_if_traps(PhaseIterGVN& igvn) {
1982   for (int i = _unstable_if_traps.length() - 1; i >= 0; --i) {
1983     UnstableIfTrap* trap = _unstable_if_traps.at(i);
1984     CallStaticJavaNode* unc = trap->uncommon_trap();
1985     int next_bci = trap->next_bci();
1986     bool modified = trap->modified();
1987 
1988     if (next_bci != -1 && !modified) {
1989       assert(!_dead_node_list.test(unc->_idx), "changing a dead node!");
1990       JVMState* jvms = unc->jvms();
1991       ciMethod* method = jvms->method();
1992       ciBytecodeStream iter(method);
1993 
1994       iter.force_bci(jvms->bci());
1995       assert(next_bci == iter.next_bci() || next_bci == iter.get_dest(), "wrong next_bci at unstable_if");
1996       Bytecodes::Code c = iter.cur_bc();
1997       Node* lhs = nullptr;
1998       Node* rhs = nullptr;
1999       if (c == Bytecodes::_if_acmpeq || c == Bytecodes::_if_acmpne) {
2000         lhs = unc->peek_operand(0);
2001         rhs = unc->peek_operand(1);
2002       } else if (c == Bytecodes::_ifnull || c == Bytecodes::_ifnonnull) {
2003         lhs = unc->peek_operand(0);
2004       }
2005 
2006       ResourceMark rm;
2007       const MethodLivenessResult& live_locals = method->liveness_at_bci(next_bci);
2008       assert(live_locals.is_valid(), "broken liveness info");
2009       int len = (int)live_locals.size();
2010 
2011       for (int i = 0; i < len; i++) {
2012         Node* local = unc->local(jvms, i);
2013         // kill local using the liveness of next_bci.
2014         // give up when the local looks like an operand to secure reexecution.
2015         if (!live_locals.at(i) && !local->is_top() && local != lhs && local!= rhs) {
2016           uint idx = jvms->locoff() + i;
2017 #ifdef ASSERT
2018           if (PrintOpto && Verbose) {
2019             tty->print("[unstable_if] kill local#%d: ", idx);
2020             local->dump();
2021             tty->cr();
2022           }
2023 #endif
2024           igvn.replace_input_of(unc, idx, top());
2025           modified = true;
2026         }
2027       }
2028     }
2029 
2030     // keep the mondified trap for late query
2031     if (modified) {
2032       trap->set_modified();
2033     } else {
2034       _unstable_if_traps.delete_at(i);
2035     }
2036   }
2037   igvn.optimize();
2038 }
2039 
2040 // StringOpts and late inlining of string methods
2041 void Compile::inline_string_calls(bool parse_time) {
2042   {
2043     // remove useless nodes to make the usage analysis simpler
2044     ResourceMark rm;
2045     PhaseRemoveUseless pru(initial_gvn(), *igvn_worklist());
2046   }
2047 
2048   {
2049     ResourceMark rm;
2050     print_method(PHASE_BEFORE_STRINGOPTS, 3);
2051     PhaseStringOpts pso(initial_gvn());
2052     print_method(PHASE_AFTER_STRINGOPTS, 3);
2053   }
2054 
2055   // now inline anything that we skipped the first time around
2056   if (!parse_time) {
2057     _late_inlines_pos = _late_inlines.length();
2058   }
2059 
2060   assert(!do_cleanup(), "already set");
2061 
2062   while (_string_late_inlines.length() > 0) {
2063     CallGenerator* cg = _string_late_inlines.pop();
2064     cg->do_late_inline();
2065     if (failing())  return;
2066     set_do_cleanup(false); // ignore and reset
2067   }
2068   _string_late_inlines.trunc_to(0);
2069 }
2070 
2071 // Late inlining of boxing methods
2072 void Compile::inline_boxing_calls(PhaseIterGVN& igvn) {
2073   if (_boxing_late_inlines.length() > 0) {
2074     assert(has_boxed_value(), "inconsistent");
2075 
2076     set_inlining_incrementally(true);
2077 
2078     igvn_worklist()->ensure_empty(); // should be done with igvn
2079 
2080     _late_inlines_pos = _late_inlines.length();
2081 
2082     assert(!do_cleanup(), "already set");
2083 
2084     while (_boxing_late_inlines.length() > 0) {
2085       CallGenerator* cg = _boxing_late_inlines.pop();
2086       cg->do_late_inline();
2087       if (failing())  return;
2088       set_do_cleanup(false); // ignore and reset
2089     }
2090     _boxing_late_inlines.trunc_to(0);
2091 
2092     inline_incrementally_cleanup(igvn);
2093 
2094     set_inlining_incrementally(false);
2095   }
2096 }
2097 
2098 bool Compile::inline_incrementally_one() {
2099   assert(IncrementalInline, "incremental inlining should be on");
2100   assert(_late_inlines.length() > 0, "should have been checked by caller");
2101 
2102   TracePhase tp(_t_incrInline_inline);
2103 
2104   set_inlining_progress(false);
2105   set_do_cleanup(false);
2106 
2107   for (int i = 0; i < _late_inlines.length(); i++) {
2108     _late_inlines_pos = i+1;
2109     CallGenerator* cg = _late_inlines.at(i);
2110     bool is_scheduled_for_igvn_before = C->igvn_worklist()->member(cg->call_node());
2111     bool does_dispatch = cg->is_virtual_late_inline() || cg->is_mh_late_inline();
2112     if (inlining_incrementally() || does_dispatch) { // a call can be either inlined or strength-reduced to a direct call
2113       if (should_stress_inlining()) {
2114         // randomly add repeated inline attempt if stress-inlining
2115         cg->call_node()->set_generator(cg);
2116         C->igvn_worklist()->push(cg->call_node());
2117         continue;
2118       }
2119       cg->do_late_inline();
2120       assert(_late_inlines.at(i) == cg, "no insertions before current position allowed");
2121       if (failing()) {
2122         return false;
2123       } else if (inlining_progress()) {
2124         _late_inlines_pos = i+1; // restore the position in case new elements were inserted
2125         print_method(PHASE_INCREMENTAL_INLINE_STEP, 3, cg->call_node());
2126         break; // process one call site at a time
2127       } else {
2128         bool is_scheduled_for_igvn_after = C->igvn_worklist()->member(cg->call_node());
2129         if (!is_scheduled_for_igvn_before && is_scheduled_for_igvn_after) {
2130           // Avoid potential infinite loop if node already in the IGVN list
2131           assert(false, "scheduled for IGVN during inlining attempt");
2132         } else {
2133           // Ensure call node has not disappeared from IGVN worklist during a failed inlining attempt
2134           assert(!is_scheduled_for_igvn_before || is_scheduled_for_igvn_after, "call node removed from IGVN list during inlining pass");
2135           cg->call_node()->set_generator(cg);
2136         }
2137       }
2138     } else {
2139       // Ignore late inline direct calls when inlining is not allowed.
2140       // They are left in the late inline list when node budget is exhausted until the list is fully drained.
2141     }
2142   }
2143   // Remove processed elements.
2144   _late_inlines.remove_till(_late_inlines_pos);
2145   _late_inlines_pos = 0;
2146 
2147   assert(inlining_progress() || _late_inlines.length() == 0, "no progress");
2148 
2149   bool needs_cleanup = do_cleanup() || over_inlining_cutoff();
2150 
2151   set_inlining_progress(false);
2152   set_do_cleanup(false);
2153 
2154   bool force_cleanup = directive()->IncrementalInlineForceCleanupOption;
2155   return (_late_inlines.length() > 0) && !needs_cleanup && !force_cleanup;
2156 }
2157 
2158 void Compile::inline_incrementally_cleanup(PhaseIterGVN& igvn) {
2159   {
2160     TracePhase tp(_t_incrInline_pru);
2161     ResourceMark rm;
2162     PhaseRemoveUseless pru(initial_gvn(), *igvn_worklist());
2163   }
2164   {
2165     TracePhase tp(_t_incrInline_igvn);
2166     igvn.reset();
2167     igvn.optimize();
2168     if (failing()) return;
2169   }
2170   print_method(PHASE_INCREMENTAL_INLINE_CLEANUP, 3);
2171 }
2172 
2173 template<typename E>
2174 static void shuffle_array(Compile& C, GrowableArray<E>& array) {
2175   if (array.length() < 2) {
2176     return;
2177   }
2178   for (uint i = array.length() - 1; i >= 1; i--) {
2179     uint j = C.random() % (i + 1);
2180     swap(array.at(i), array.at(j));
2181   }
2182 }
2183 
2184 void Compile::shuffle_late_inlines() {
2185   shuffle_array(*C, _late_inlines);
2186 }
2187 
2188 // Perform incremental inlining until bound on number of live nodes is reached
2189 void Compile::inline_incrementally(PhaseIterGVN& igvn) {
2190   TracePhase tp(_t_incrInline);
2191 
2192   set_inlining_incrementally(true);
2193   uint low_live_nodes = 0;
2194 
2195   if (StressIncrementalInlining) {
2196     shuffle_late_inlines();
2197   }
2198 
2199   while (_late_inlines.length() > 0) {
2200     if (live_nodes() > node_count_inlining_cutoff()) {
2201       if (low_live_nodes < node_count_inlining_cutoff() * 8 / 10) {
2202         TracePhase tp(_t_incrInline_ideal);
2203         // PhaseIdealLoop is expensive so we only try it once we are
2204         // out of live nodes and we only try it again if the previous
2205         // helped got the number of nodes down significantly
2206         PhaseIdealLoop::optimize(igvn, LoopOptsNone);
2207         if (failing())  return;
2208         low_live_nodes = live_nodes();
2209         _major_progress = true;
2210       }
2211 
2212       if (live_nodes() > node_count_inlining_cutoff()) {
2213         bool do_print_inlining = print_inlining() || print_intrinsics();
2214         if (do_print_inlining || log() != nullptr) {
2215           // Print inlining message for candidates that we couldn't inline for lack of space.
2216           for (int i = 0; i < _late_inlines.length(); i++) {
2217             CallGenerator* cg = _late_inlines.at(i);
2218             const char* msg = "live nodes > LiveNodeCountInliningCutoff";
2219             if (do_print_inlining) {
2220               inline_printer()->record(cg->method(), cg->call_node()->jvms(), InliningResult::FAILURE, msg);
2221             }
2222             log_late_inline_failure(cg, msg);
2223           }
2224         }
2225         break; // finish
2226       }
2227     }
2228 
2229     igvn_worklist()->ensure_empty(); // should be done with igvn
2230 
2231     if (_late_inlines.length() == 0) {
2232       break; // no more progress
2233     }
2234 
2235     while (inline_incrementally_one()) {
2236       assert(!failing_internal() || failure_is_artificial(), "inconsistent");
2237     }
2238     if (failing())  return;
2239 
2240     inline_incrementally_cleanup(igvn);
2241 
2242     print_method(PHASE_INCREMENTAL_INLINE_STEP, 3);
2243 
2244     if (failing())  return;
2245   }
2246 
2247   igvn_worklist()->ensure_empty(); // should be done with igvn
2248 
2249   if (_string_late_inlines.length() > 0) {
2250     assert(has_stringbuilder(), "inconsistent");
2251 
2252     inline_string_calls(false);
2253 
2254     if (failing())  return;
2255 
2256     inline_incrementally_cleanup(igvn);
2257   }
2258 
2259   set_inlining_incrementally(false);
2260 }
2261 
2262 void Compile::process_late_inline_calls_no_inline(PhaseIterGVN& igvn) {
2263   // "inlining_incrementally() == false" is used to signal that no inlining is allowed
2264   // (see LateInlineVirtualCallGenerator::do_late_inline_check() for details).
2265   // Tracking and verification of modified nodes is disabled by setting "_modified_nodes == nullptr"
2266   // as if "inlining_incrementally() == true" were set.
2267   assert(inlining_incrementally() == false, "not allowed");
2268   assert(_modified_nodes == nullptr, "not allowed");
2269   assert(_late_inlines.length() > 0, "sanity");
2270 
2271   if (StressIncrementalInlining) {
2272     shuffle_late_inlines();
2273   }
2274 
2275   while (_late_inlines.length() > 0) {
2276     igvn_worklist()->ensure_empty(); // should be done with igvn
2277 
2278     while (inline_incrementally_one()) {
2279       assert(!failing_internal() || failure_is_artificial(), "inconsistent");
2280     }
2281     if (failing())  return;
2282 
2283     inline_incrementally_cleanup(igvn);
2284   }
2285 }
2286 
2287 bool Compile::optimize_loops(PhaseIterGVN& igvn, LoopOptsMode mode) {
2288   if (_loop_opts_cnt > 0) {
2289     while (major_progress() && (_loop_opts_cnt > 0)) {
2290       TracePhase tp(_t_idealLoop);
2291       PhaseIdealLoop::optimize(igvn, mode);
2292       _loop_opts_cnt--;
2293       if (failing())  return false;
2294       if (major_progress()) {
2295         print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
2296       }
2297     }
2298   }
2299   return true;
2300 }
2301 
2302 // Remove edges from "root" to each SafePoint at a backward branch.
2303 // They were inserted during parsing (see add_safepoint()) to make
2304 // infinite loops without calls or exceptions visible to root, i.e.,
2305 // useful.
2306 void Compile::remove_root_to_sfpts_edges(PhaseIterGVN& igvn) {
2307   Node *r = root();
2308   if (r != nullptr) {
2309     for (uint i = r->req(); i < r->len(); ++i) {
2310       Node *n = r->in(i);
2311       if (n != nullptr && n->is_SafePoint()) {
2312         r->rm_prec(i);
2313         if (n->outcnt() == 0) {
2314           igvn.remove_dead_node(n, PhaseIterGVN::NodeOrigin::Graph);
2315         }
2316         --i;
2317       }
2318     }
2319     // Parsing may have added top inputs to the root node (Path
2320     // leading to the Halt node proven dead). Make sure we get a
2321     // chance to clean them up.
2322     igvn._worklist.push(r);
2323     igvn.optimize();
2324   }
2325 }
2326 
2327 //------------------------------Optimize---------------------------------------
2328 // Given a graph, optimize it.
2329 void Compile::Optimize() {
2330   TracePhase tp(_t_optimizer);
2331 
2332 #ifndef PRODUCT
2333   if (env()->break_at_compile()) {
2334     BREAKPOINT;
2335   }
2336 
2337 #endif
2338 
2339   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
2340 #ifdef ASSERT
2341   bs->verify_gc_barriers(this, BarrierSetC2::BeforeOptimize);
2342 #endif
2343 
2344   ResourceMark rm;
2345 
2346   NOT_PRODUCT( verify_graph_edges(); )
2347 
2348   print_method(PHASE_AFTER_PARSING, 1);
2349 
2350  {
2351   // Iterative Global Value Numbering, including ideal transforms
2352   PhaseIterGVN igvn;
2353 #ifdef ASSERT
2354   _modified_nodes = new (comp_arena()) Unique_Node_List(comp_arena());
2355 #endif
2356   {
2357     TracePhase tp(_t_iterGVN);
2358     igvn.optimize(true);
2359   }
2360 
2361   if (failing())  return;
2362 
2363   print_method(PHASE_ITER_GVN1, 2);
2364 
2365   process_for_unstable_if_traps(igvn);
2366 
2367   if (failing())  return;
2368 
2369   inline_incrementally(igvn);
2370 
2371   print_method(PHASE_INCREMENTAL_INLINE, 2);
2372 
2373   if (failing())  return;
2374 
2375   if (eliminate_boxing()) {
2376     // Inline valueOf() methods now.
2377     inline_boxing_calls(igvn);
2378 
2379     if (failing())  return;
2380 
2381     if (AlwaysIncrementalInline || StressIncrementalInlining) {
2382       inline_incrementally(igvn);
2383     }
2384 
2385     print_method(PHASE_INCREMENTAL_BOXING_INLINE, 2);
2386 
2387     if (failing())  return;
2388   }
2389 
2390   // Remove the speculative part of types and clean up the graph from
2391   // the extra CastPP nodes whose only purpose is to carry them. Do
2392   // that early so that optimizations are not disrupted by the extra
2393   // CastPP nodes.
2394   remove_speculative_types(igvn);
2395 
2396   if (failing())  return;
2397 
2398   // No more new expensive nodes will be added to the list from here
2399   // so keep only the actual candidates for optimizations.
2400   cleanup_expensive_nodes(igvn);
2401 
2402   if (failing())  return;
2403 
2404   assert(EnableVectorSupport || !has_vbox_nodes(), "sanity");
2405   if (EnableVectorSupport && has_vbox_nodes()) {
2406     TracePhase tp(_t_vector);
2407     PhaseVector pv(igvn);
2408     pv.optimize_vector_boxes();
2409     if (failing())  return;
2410     print_method(PHASE_ITER_GVN_AFTER_VECTOR, 2);
2411   }
2412   assert(!has_vbox_nodes(), "sanity");
2413 
2414   if (!failing() && RenumberLiveNodes && live_nodes() + NodeLimitFudgeFactor < unique()) {
2415     Compile::TracePhase tp(_t_renumberLive);
2416     igvn_worklist()->ensure_empty(); // should be done with igvn
2417     {
2418       ResourceMark rm;
2419       PhaseRenumberLive prl(initial_gvn(), *igvn_worklist());
2420     }
2421     igvn.reset();
2422     igvn.optimize(true);
2423     if (failing()) return;
2424   }
2425 
2426   // Now that all inlining is over and no PhaseRemoveUseless will run, cut edge from root to loop
2427   // safepoints
2428   remove_root_to_sfpts_edges(igvn);
2429 
2430   if (failing())  return;
2431 
2432   _print_phase_loop_opts = has_loops();
2433   if (_print_phase_loop_opts) {
2434     print_method(PHASE_BEFORE_LOOP_OPTS, 2);
2435   }
2436 
2437   // Perform escape analysis
2438   if (do_escape_analysis() && ConnectionGraph::has_candidates(this)) {
2439     if (has_loops()) {
2440       // Cleanup graph (remove dead nodes).
2441       TracePhase tp(_t_idealLoop);
2442       PhaseIdealLoop::optimize(igvn, LoopOptsMaxUnroll);
2443       if (failing())  return;
2444     }
2445     bool progress;
2446     print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
2447     do {
2448       ConnectionGraph::do_analysis(this, &igvn);
2449 
2450       if (failing())  return;
2451 
2452       int mcount = macro_count(); // Record number of allocations and locks before IGVN
2453 
2454       // Optimize out fields loads from scalar replaceable allocations.
2455       igvn.optimize(true);
2456       print_method(PHASE_ITER_GVN_AFTER_EA, 2);
2457 
2458       if (failing()) return;
2459 
2460       if (congraph() != nullptr && macro_count() > 0) {
2461         TracePhase tp(_t_macroEliminate);
2462         PhaseMacroExpand mexp(igvn);
2463         mexp.eliminate_macro_nodes();
2464         if (failing()) return;
2465         print_method(PHASE_AFTER_MACRO_ELIMINATION, 2);
2466 
2467         igvn.set_delay_transform(false);
2468         igvn.optimize();
2469         if (failing()) return;
2470 
2471         print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
2472       }
2473 
2474       ConnectionGraph::verify_ram_nodes(this, root());
2475       if (failing())  return;
2476 
2477       progress = do_iterative_escape_analysis() &&
2478                  (macro_count() < mcount) &&
2479                  ConnectionGraph::has_candidates(this);
2480       // Try again if candidates exist and made progress
2481       // by removing some allocations and/or locks.
2482     } while (progress);
2483   }
2484 
2485   // Loop transforms on the ideal graph.  Range Check Elimination,
2486   // peeling, unrolling, etc.
2487 
2488   // Set loop opts counter
2489   if((_loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
2490     {
2491       TracePhase tp(_t_idealLoop);
2492       PhaseIdealLoop::optimize(igvn, LoopOptsDefault);
2493       _loop_opts_cnt--;
2494       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP1, 2);
2495       if (failing())  return;
2496     }
2497     // Loop opts pass if partial peeling occurred in previous pass
2498     if(PartialPeelLoop && major_progress() && (_loop_opts_cnt > 0)) {
2499       TracePhase tp(_t_idealLoop);
2500       PhaseIdealLoop::optimize(igvn, LoopOptsSkipSplitIf);
2501       _loop_opts_cnt--;
2502       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP2, 2);
2503       if (failing())  return;
2504     }
2505     // Loop opts pass for loop-unrolling before CCP
2506     if(major_progress() && (_loop_opts_cnt > 0)) {
2507       TracePhase tp(_t_idealLoop);
2508       PhaseIdealLoop::optimize(igvn, LoopOptsSkipSplitIf);
2509       _loop_opts_cnt--;
2510       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP3, 2);
2511     }
2512     if (!failing()) {
2513       // Verify that last round of loop opts produced a valid graph
2514       PhaseIdealLoop::verify(igvn);
2515     }
2516   }
2517   if (failing())  return;
2518 
2519   // Conditional Constant Propagation;
2520   print_method(PHASE_BEFORE_CCP1, 2);
2521   PhaseCCP ccp( &igvn );
2522   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
2523   {
2524     TracePhase tp(_t_ccp);
2525     ccp.do_transform();
2526   }
2527   print_method(PHASE_CCP1, 2);
2528 
2529   assert( true, "Break here to ccp.dump_old2new_map()");
2530 
2531   // Iterative Global Value Numbering, including ideal transforms
2532   {
2533     TracePhase tp(_t_iterGVN2);
2534     igvn.reset_from_igvn(&ccp);
2535     igvn.optimize(true);
2536   }
2537   print_method(PHASE_ITER_GVN2, 2);
2538 
2539   if (failing())  return;
2540 
2541   // Loop transforms on the ideal graph.  Range Check Elimination,
2542   // peeling, unrolling, etc.
2543   if (!optimize_loops(igvn, LoopOptsDefault)) {
2544     return;
2545   }
2546 
2547   C->clear_major_progress(); // ensure that major progress is now clear
2548 
2549   process_for_post_loop_opts_igvn(igvn);
2550 
2551   if (failing())  return;
2552 
2553   // Once loop optimizations are over, it is safe to get rid of all reachability fence nodes and
2554   // migrate reachability edges to safepoints.
2555   if (OptimizeReachabilityFences && _reachability_fences.length() > 0) {
2556     TracePhase tp1(_t_idealLoop);
2557     TracePhase tp2(_t_reachability);
2558     PhaseIdealLoop::optimize(igvn, PostLoopOptsExpandReachabilityFences);
2559     print_method(PHASE_EXPAND_REACHABILITY_FENCES, 2);
2560     if (failing())  return;
2561     assert(_reachability_fences.length() == 0 || PreserveReachabilityFencesOnConstants, "no RF nodes allowed");
2562   }
2563 
2564   process_for_merge_stores_igvn(igvn);
2565 
2566   if (failing())  return;
2567 
2568 #ifdef ASSERT
2569   bs->verify_gc_barriers(this, BarrierSetC2::BeforeMacroExpand);
2570 #endif
2571 
2572   {
2573     TracePhase tp(_t_macroExpand);
2574     print_method(PHASE_BEFORE_MACRO_EXPANSION, 3);
2575     PhaseMacroExpand  mex(igvn);
2576     // Do not allow new macro nodes once we start to eliminate and expand
2577     C->reset_allow_macro_nodes();
2578     // Last attempt to eliminate macro nodes before expand
2579     mex.eliminate_macro_nodes();
2580     if (failing()) {
2581       return;
2582     }
2583     mex.eliminate_opaque_looplimit_macro_nodes();
2584     if (failing()) {
2585       return;
2586     }
2587     print_method(PHASE_AFTER_MACRO_ELIMINATION, 2);
2588     if (mex.expand_macro_nodes()) {
2589       assert(failing(), "must bail out w/ explicit message");
2590       return;
2591     }
2592     print_method(PHASE_AFTER_MACRO_EXPANSION, 2);
2593   }
2594 
2595   {
2596     TracePhase tp(_t_barrierExpand);
2597     if (bs->expand_barriers(this, igvn)) {
2598       assert(failing(), "must bail out w/ explicit message");
2599       return;
2600     }
2601     print_method(PHASE_BARRIER_EXPANSION, 2);
2602   }
2603 
2604   if (C->max_vector_size() > 0) {
2605     C->optimize_logic_cones(igvn);
2606     igvn.optimize();
2607     if (failing()) return;
2608   }
2609 
2610   DEBUG_ONLY( _modified_nodes = nullptr; )
2611 
2612   assert(igvn._worklist.size() == 0, "not empty");
2613 
2614   if (_late_inlines.length() > 0) {
2615     // More opportunities to optimize virtual and MH calls.
2616     // Though it's maybe too late to perform inlining, strength-reducing them to direct calls is still an option.
2617     process_late_inline_calls_no_inline(igvn);
2618     if (failing())  return;
2619   }
2620   assert(_late_inlines.length() == 0, "late inline queue must be drained");
2621  } // (End scope of igvn; run destructor if necessary for asserts.)
2622 
2623  check_no_dead_use();
2624 
2625  // We will never use the NodeHash table any more. Clear it so that final_graph_reshaping does not have
2626  // to remove hashes to unlock nodes for modifications.
2627  C->node_hash()->clear();
2628 
2629  // A method with only infinite loops has no edges entering loops from root
2630  {
2631    TracePhase tp(_t_graphReshaping);
2632    if (final_graph_reshaping()) {
2633      assert(failing(), "must bail out w/ explicit message");
2634      return;
2635    }
2636  }
2637 
2638   // Unique DeadPath node should not be used anymore
2639   _dead_path = nullptr;
2640 
2641  print_method(PHASE_OPTIMIZE_FINISHED, 2);
2642  DEBUG_ONLY(set_phase_optimize_finished();)
2643 }
2644 
2645 #ifdef ASSERT
2646 void Compile::check_no_dead_use() const {
2647   ResourceMark rm;
2648   Unique_Node_List wq;
2649   wq.push(root());
2650   for (uint i = 0; i < wq.size(); ++i) {
2651     Node* n = wq.at(i);
2652     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
2653       Node* u = n->fast_out(j);
2654       if (u->outcnt() == 0 && !u->is_Con()) {
2655         u->dump();
2656         fatal("no reachable node should have no use");
2657       }
2658       wq.push(u);
2659     }
2660   }
2661 }
2662 #endif
2663 
2664 void Compile::inline_vector_reboxing_calls() {
2665   assert(!do_cleanup(), "already set");
2666   if (C->_vector_reboxing_late_inlines.length() > 0) {
2667     _late_inlines_pos = C->_late_inlines.length();
2668     while (_vector_reboxing_late_inlines.length() > 0) {
2669       CallGenerator* cg = _vector_reboxing_late_inlines.pop();
2670       cg->do_late_inline();
2671       if (failing())  return;
2672       assert(!do_cleanup(), "should not be set");
2673       print_method(PHASE_INLINE_VECTOR_REBOX, 3, cg->call_node());
2674     }
2675     _vector_reboxing_late_inlines.trunc_to(0);
2676   }
2677 }
2678 
2679 bool Compile::has_vbox_nodes() {
2680   if (C->_vector_reboxing_late_inlines.length() > 0) {
2681     return true;
2682   }
2683   for (int macro_idx = C->macro_count() - 1; macro_idx >= 0; macro_idx--) {
2684     Node * n = C->macro_node(macro_idx);
2685     assert(n->is_macro(), "only macro nodes expected here");
2686     if (n->Opcode() == Op_VectorUnbox || n->Opcode() == Op_VectorBox || n->Opcode() == Op_VectorBoxAllocate) {
2687       return true;
2688     }
2689   }
2690   return false;
2691 }
2692 
2693 //---------------------------- Bitwise operation packing optimization ---------------------------
2694 
2695 static bool is_vector_unary_bitwise_op(Node* n) {
2696   return n->Opcode() == Op_XorV &&
2697          VectorNode::is_vector_bitwise_not_pattern(n);
2698 }
2699 
2700 static bool is_vector_binary_bitwise_op(Node* n) {
2701   switch (n->Opcode()) {
2702     case Op_AndV:
2703     case Op_OrV:
2704       return true;
2705 
2706     case Op_XorV:
2707       return !is_vector_unary_bitwise_op(n);
2708 
2709     default:
2710       return false;
2711   }
2712 }
2713 
2714 static bool is_vector_ternary_bitwise_op(Node* n) {
2715   return n->Opcode() == Op_MacroLogicV;
2716 }
2717 
2718 static bool is_vector_bitwise_op(Node* n) {
2719   return is_vector_unary_bitwise_op(n)  ||
2720          is_vector_binary_bitwise_op(n) ||
2721          is_vector_ternary_bitwise_op(n);
2722 }
2723 
2724 static bool is_vector_bitwise_cone_root(Node* n) {
2725   if (n->bottom_type()->isa_pvectmask() || !is_vector_bitwise_op(n)) {
2726     return false;
2727   }
2728   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2729     if (is_vector_bitwise_op(n->fast_out(i))) {
2730       return false;
2731     }
2732   }
2733   return true;
2734 }
2735 
2736 static uint collect_unique_inputs(Node* n, Unique_Node_List& inputs) {
2737   uint cnt = 0;
2738   if (is_vector_bitwise_op(n)) {
2739     uint inp_cnt = n->is_predicated_vector() ? n->req()-1 : n->req();
2740     if (VectorNode::is_vector_bitwise_not_pattern(n)) {
2741       assert(n->req() == (n->is_predicated_vector() ? 4 : 3), "must have 2 data inputs");
2742       Node* opnd = VectorNode::is_all_ones_vector(n->in(1)) ? n->in(2) : n->in(1);
2743       if (!inputs.member(opnd)) {
2744         inputs.push(opnd);
2745         cnt++;
2746       }
2747       assert(cnt <= 1, "not unary");
2748     } else {
2749       uint last_req = inp_cnt;
2750       if (is_vector_ternary_bitwise_op(n)) {
2751         last_req = inp_cnt - 1; // skip last input
2752       }
2753       for (uint i = 1; i < last_req; i++) {
2754         Node* def = n->in(i);
2755         if (!inputs.member(def)) {
2756           inputs.push(def);
2757           cnt++;
2758         }
2759       }
2760     }
2761   } else { // not a bitwise operations
2762     if (!inputs.member(n)) {
2763       inputs.push(n);
2764       cnt++;
2765     }
2766   }
2767   return cnt;
2768 }
2769 
2770 void Compile::collect_logic_cone_roots(Unique_Node_List& list) {
2771   Unique_Node_List useful_nodes;
2772   C->identify_useful_nodes(useful_nodes);
2773 
2774   for (uint i = 0; i < useful_nodes.size(); i++) {
2775     Node* n = useful_nodes.at(i);
2776     if (is_vector_bitwise_cone_root(n)) {
2777       list.push(n);
2778     }
2779   }
2780 }
2781 
2782 Node* Compile::xform_to_MacroLogicV(PhaseIterGVN& igvn,
2783                                     const TypeVect* vt,
2784                                     Unique_Node_List& partition,
2785                                     Unique_Node_List& inputs) {
2786   assert(partition.size() == 2 || partition.size() == 3, "not supported");
2787   assert(inputs.size()    == 2 || inputs.size()    == 3, "not supported");
2788   assert(Matcher::match_rule_supported_vector(Op_MacroLogicV, vt->length(), vt->element_basic_type()), "not supported");
2789 
2790   Node* in1 = inputs.at(0);
2791   Node* in2 = inputs.at(1);
2792   Node* in3 = (inputs.size() == 3 ? inputs.at(2) : in2);
2793 
2794   uint func = compute_truth_table(partition, inputs);
2795 
2796   Node* pn = partition.at(partition.size() - 1);
2797   Node* mask = pn->is_predicated_vector() ? pn->in(pn->req()-1) : nullptr;
2798   return igvn.transform(MacroLogicVNode::make(igvn, in1, in2, in3, mask, func, vt));
2799 }
2800 
2801 static uint extract_bit(uint func, uint pos) {
2802   return (func & (1 << pos)) >> pos;
2803 }
2804 
2805 //
2806 //  A macro logic node represents a truth table. It has 4 inputs,
2807 //  First three inputs corresponds to 3 columns of a truth table
2808 //  and fourth input captures the logic function.
2809 //
2810 //  eg.  fn = (in1 AND in2) OR in3;
2811 //
2812 //      MacroNode(in1,in2,in3,fn)
2813 //
2814 //  -----------------
2815 //  in1 in2 in3  fn
2816 //  -----------------
2817 //  0    0   0    0
2818 //  0    0   1    1
2819 //  0    1   0    0
2820 //  0    1   1    1
2821 //  1    0   0    0
2822 //  1    0   1    1
2823 //  1    1   0    1
2824 //  1    1   1    1
2825 //
2826 
2827 uint Compile::eval_macro_logic_op(uint func, uint in1 , uint in2, uint in3) {
2828   int res = 0;
2829   for (int i = 0; i < 8; i++) {
2830     int bit1 = extract_bit(in1, i);
2831     int bit2 = extract_bit(in2, i);
2832     int bit3 = extract_bit(in3, i);
2833 
2834     int func_bit_pos = (bit1 << 2 | bit2 << 1 | bit3);
2835     int func_bit = extract_bit(func, func_bit_pos);
2836 
2837     res |= func_bit << i;
2838   }
2839   return res;
2840 }
2841 
2842 static uint eval_operand(Node* n, HashTable<Node*,uint>& eval_map) {
2843   assert(n != nullptr, "");
2844   assert(eval_map.contains(n), "absent");
2845   return *(eval_map.get(n));
2846 }
2847 
2848 static void eval_operands(Node* n,
2849                           uint& func1, uint& func2, uint& func3,
2850                           HashTable<Node*,uint>& eval_map) {
2851   assert(is_vector_bitwise_op(n), "");
2852 
2853   if (is_vector_unary_bitwise_op(n)) {
2854     Node* opnd = n->in(1);
2855     if (VectorNode::is_vector_bitwise_not_pattern(n) && VectorNode::is_all_ones_vector(opnd)) {
2856       opnd = n->in(2);
2857     }
2858     func1 = eval_operand(opnd, eval_map);
2859   } else if (is_vector_binary_bitwise_op(n)) {
2860     func1 = eval_operand(n->in(1), eval_map);
2861     func2 = eval_operand(n->in(2), eval_map);
2862   } else {
2863     assert(is_vector_ternary_bitwise_op(n), "unknown operation");
2864     func1 = eval_operand(n->in(1), eval_map);
2865     func2 = eval_operand(n->in(2), eval_map);
2866     func3 = eval_operand(n->in(3), eval_map);
2867   }
2868 }
2869 
2870 uint Compile::compute_truth_table(Unique_Node_List& partition, Unique_Node_List& inputs) {
2871   assert(inputs.size() <= 3, "sanity");
2872   ResourceMark rm;
2873   uint res = 0;
2874   HashTable<Node*,uint> eval_map;
2875 
2876   // Populate precomputed functions for inputs.
2877   // Each input corresponds to one column of 3 input truth-table.
2878   uint input_funcs[] = { 0xAA,   // (_, _, c) -> c
2879                          0xCC,   // (_, b, _) -> b
2880                          0xF0 }; // (a, _, _) -> a
2881   for (uint i = 0; i < inputs.size(); i++) {
2882     eval_map.put(inputs.at(i), input_funcs[2-i]);
2883   }
2884 
2885   for (uint i = 0; i < partition.size(); i++) {
2886     Node* n = partition.at(i);
2887 
2888     uint func1 = 0, func2 = 0, func3 = 0;
2889     eval_operands(n, func1, func2, func3, eval_map);
2890 
2891     switch (n->Opcode()) {
2892       case Op_OrV:
2893         assert(func3 == 0, "not binary");
2894         res = func1 | func2;
2895         break;
2896       case Op_AndV:
2897         assert(func3 == 0, "not binary");
2898         res = func1 & func2;
2899         break;
2900       case Op_XorV:
2901         if (VectorNode::is_vector_bitwise_not_pattern(n)) {
2902           assert(func2 == 0 && func3 == 0, "not unary");
2903           res = (~func1) & 0xFF;
2904         } else {
2905           assert(func3 == 0, "not binary");
2906           res = func1 ^ func2;
2907         }
2908         break;
2909       case Op_MacroLogicV:
2910         // Ordering of inputs may change during evaluation of sub-tree
2911         // containing MacroLogic node as a child node, thus a re-evaluation
2912         // makes sure that function is evaluated in context of current
2913         // inputs.
2914         res = eval_macro_logic_op(n->in(4)->get_int(), func1, func2, func3);
2915         break;
2916 
2917       default: assert(false, "not supported: %s", n->Name());
2918     }
2919     assert(res <= 0xFF, "invalid");
2920     eval_map.put(n, res);
2921   }
2922   return res;
2923 }
2924 
2925 // Criteria under which nodes gets packed into a macro logic node:-
2926 //  1) Parent and both child nodes are all unmasked or masked with
2927 //     same predicates.
2928 //  2) Masked parent can be packed with left child if it is predicated
2929 //     and both have same predicates.
2930 //  3) Masked parent can be packed with right child if its un-predicated
2931 //     or has matching predication condition.
2932 //  4) An unmasked parent can be packed with an unmasked child.
2933 bool Compile::compute_logic_cone(Node* n, Unique_Node_List& partition, Unique_Node_List& inputs) {
2934   assert(partition.size() == 0, "not empty");
2935   assert(inputs.size() == 0, "not empty");
2936   if (is_vector_ternary_bitwise_op(n)) {
2937     return false;
2938   }
2939 
2940   bool is_unary_op = is_vector_unary_bitwise_op(n);
2941   if (is_unary_op) {
2942     assert(collect_unique_inputs(n, inputs) == 1, "not unary");
2943     return false; // too few inputs
2944   }
2945 
2946   bool pack_left_child = true;
2947   bool pack_right_child = true;
2948 
2949   bool left_child_LOP = is_vector_bitwise_op(n->in(1));
2950   bool right_child_LOP = is_vector_bitwise_op(n->in(2));
2951 
2952   int left_child_input_cnt = 0;
2953   int right_child_input_cnt = 0;
2954 
2955   bool parent_is_predicated = n->is_predicated_vector();
2956   bool left_child_predicated = n->in(1)->is_predicated_vector();
2957   bool right_child_predicated = n->in(2)->is_predicated_vector();
2958 
2959   Node* parent_pred = parent_is_predicated ? n->in(n->req()-1) : nullptr;
2960   Node* left_child_pred = left_child_predicated ? n->in(1)->in(n->in(1)->req()-1) : nullptr;
2961   Node* right_child_pred = right_child_predicated ? n->in(1)->in(n->in(1)->req()-1) : nullptr;
2962 
2963   do {
2964     if (pack_left_child && left_child_LOP &&
2965         ((!parent_is_predicated && !left_child_predicated) ||
2966         ((parent_is_predicated && left_child_predicated &&
2967           parent_pred == left_child_pred)))) {
2968        partition.push(n->in(1));
2969        left_child_input_cnt = collect_unique_inputs(n->in(1), inputs);
2970     } else {
2971        inputs.push(n->in(1));
2972        left_child_input_cnt = 1;
2973     }
2974 
2975     if (pack_right_child && right_child_LOP &&
2976         (!right_child_predicated ||
2977          (right_child_predicated && parent_is_predicated &&
2978           parent_pred == right_child_pred))) {
2979        partition.push(n->in(2));
2980        right_child_input_cnt = collect_unique_inputs(n->in(2), inputs);
2981     } else {
2982        inputs.push(n->in(2));
2983        right_child_input_cnt = 1;
2984     }
2985 
2986     if (inputs.size() > 3) {
2987       assert(partition.size() > 0, "");
2988       inputs.clear();
2989       partition.clear();
2990       if (left_child_input_cnt > right_child_input_cnt) {
2991         pack_left_child = false;
2992       } else {
2993         pack_right_child = false;
2994       }
2995     } else {
2996       break;
2997     }
2998   } while(true);
2999 
3000   if(partition.size()) {
3001     partition.push(n);
3002   }
3003 
3004   return (partition.size() == 2 || partition.size() == 3) &&
3005          (inputs.size()    == 2 || inputs.size()    == 3);
3006 }
3007 
3008 void Compile::process_logic_cone_root(PhaseIterGVN &igvn, Node *n, VectorSet &visited) {
3009   assert(is_vector_bitwise_op(n), "not a root");
3010 
3011   visited.set(n->_idx);
3012 
3013   // 1) Do a DFS walk over the logic cone.
3014   for (uint i = 1; i < n->req(); i++) {
3015     Node* in = n->in(i);
3016     if (!visited.test(in->_idx) && is_vector_bitwise_op(in)) {
3017       process_logic_cone_root(igvn, in, visited);
3018     }
3019   }
3020 
3021   // 2) Bottom up traversal: Merge node[s] with
3022   // the parent to form macro logic node.
3023   Unique_Node_List partition;
3024   Unique_Node_List inputs;
3025   if (compute_logic_cone(n, partition, inputs)) {
3026     const TypeVect* vt = n->bottom_type()->is_vect();
3027     Node* pn = partition.at(partition.size() - 1);
3028     Node* mask = pn->is_predicated_vector() ? pn->in(pn->req()-1) : nullptr;
3029     if (mask == nullptr ||
3030         Matcher::match_rule_supported_vector_masked(Op_MacroLogicV, vt->length(), vt->element_basic_type())) {
3031       Node* macro_logic = xform_to_MacroLogicV(igvn, vt, partition, inputs);
3032       VectorNode::trace_new_vector(macro_logic, "MacroLogic");
3033       igvn.replace_node(n, macro_logic);
3034     }
3035   }
3036 }
3037 
3038 void Compile::optimize_logic_cones(PhaseIterGVN &igvn) {
3039   ResourceMark rm;
3040   if (Matcher::match_rule_supported(Op_MacroLogicV)) {
3041     Unique_Node_List list;
3042     collect_logic_cone_roots(list);
3043 
3044     while (list.size() > 0) {
3045       Node* n = list.pop();
3046       const TypeVect* vt = n->bottom_type()->is_vect();
3047       bool supported = Matcher::match_rule_supported_vector(Op_MacroLogicV, vt->length(), vt->element_basic_type());
3048       if (supported) {
3049         VectorSet visited(comp_arena());
3050         process_logic_cone_root(igvn, n, visited);
3051       }
3052     }
3053   }
3054 }
3055 
3056 //------------------------------Code_Gen---------------------------------------
3057 // Given a graph, generate code for it
3058 void Compile::Code_Gen() {
3059   if (failing()) {
3060     return;
3061   }
3062 
3063   // Perform instruction selection.  You might think we could reclaim Matcher
3064   // memory PDQ, but actually the Matcher is used in generating spill code.
3065   // Internals of the Matcher (including some VectorSets) must remain live
3066   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
3067   // set a bit in reclaimed memory.
3068 
3069   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
3070   // nodes.  Mapping is only valid at the root of each matched subtree.
3071   NOT_PRODUCT( verify_graph_edges(); )
3072 
3073   Matcher matcher;
3074   _matcher = &matcher;
3075   {
3076     TracePhase tp(_t_matcher);
3077     matcher.match();
3078     if (failing()) {
3079       return;
3080     }
3081   }
3082   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
3083   // nodes.  Mapping is only valid at the root of each matched subtree.
3084   NOT_PRODUCT( verify_graph_edges(); )
3085 
3086   // If you have too many nodes, or if matching has failed, bail out
3087   check_node_count(0, "out of nodes matching instructions");
3088   if (failing()) {
3089     return;
3090   }
3091 
3092   print_method(PHASE_MATCHING, 2);
3093 
3094   // Build a proper-looking CFG
3095   PhaseCFG cfg(node_arena(), root(), matcher);
3096   if (failing()) {
3097     return;
3098   }
3099   _cfg = &cfg;
3100   {
3101     TracePhase tp(_t_scheduler);
3102     bool success = cfg.do_global_code_motion();
3103     if (!success) {
3104       return;
3105     }
3106 
3107     print_method(PHASE_GLOBAL_CODE_MOTION, 2);
3108     NOT_PRODUCT( verify_graph_edges(); )
3109     cfg.verify();
3110     if (failing()) {
3111       return;
3112     }
3113   }
3114 
3115   PhaseChaitin regalloc(unique(), cfg, matcher, false);
3116   _regalloc = &regalloc;
3117   {
3118     TracePhase tp(_t_registerAllocation);
3119     // Perform register allocation.  After Chaitin, use-def chains are
3120     // no longer accurate (at spill code) and so must be ignored.
3121     // Node->LRG->reg mappings are still accurate.
3122     _regalloc->Register_Allocate();
3123 
3124     // Bail out if the allocator builds too many nodes
3125     if (failing()) {
3126       return;
3127     }
3128 
3129     print_method(PHASE_REGISTER_ALLOCATION, 2);
3130   }
3131 
3132   // Prior to register allocation we kept empty basic blocks in case the
3133   // the allocator needed a place to spill.  After register allocation we
3134   // are not adding any new instructions.  If any basic block is empty, we
3135   // can now safely remove it.
3136   {
3137     TracePhase tp(_t_blockOrdering);
3138     cfg.remove_empty_blocks();
3139     if (do_freq_based_layout()) {
3140       PhaseBlockLayout layout(cfg);
3141     } else {
3142       cfg.set_loop_alignment();
3143     }
3144     cfg.fixup_flow();
3145     cfg.remove_unreachable_blocks();
3146     cfg.verify_dominator_tree();
3147     print_method(PHASE_BLOCK_ORDERING, 3);
3148   }
3149 
3150   // Apply peephole optimizations
3151   if( OptoPeephole ) {
3152     TracePhase tp(_t_peephole);
3153     PhasePeephole peep( _regalloc, cfg);
3154     peep.do_transform();
3155     print_method(PHASE_PEEPHOLE, 3);
3156   }
3157 
3158   // Do late expand if CPU requires this.
3159   if (Matcher::require_postalloc_expand) {
3160     TracePhase tp(_t_postalloc_expand);
3161     cfg.postalloc_expand(_regalloc);
3162     print_method(PHASE_POSTALLOC_EXPAND, 3);
3163   }
3164 
3165 #ifdef ASSERT
3166   {
3167     CompilationMemoryStatistic::do_test_allocations();
3168     if (failing()) return;
3169   }
3170 #endif
3171 
3172   // Convert Nodes to instruction bits in a buffer
3173   {
3174     TracePhase tp(_t_output);
3175     PhaseOutput output;
3176     output.Output();
3177     if (failing())  return;
3178     output.install();
3179     print_method(PHASE_FINAL_CODE, 1); // Compile::_output is not null here
3180   }
3181 
3182   // He's dead, Jim.
3183   _cfg     = (PhaseCFG*)((intptr_t)0xdeadbeef);
3184   _regalloc = (PhaseChaitin*)((intptr_t)0xdeadbeef);
3185 }
3186 
3187 //------------------------------Final_Reshape_Counts---------------------------
3188 // This class defines counters and node lists collected during
3189 // the final graph reshaping.
3190 struct Final_Reshape_Counts : public StackObj {
3191   int  _java_call_count;        // count non-inlined 'java' calls
3192   int  _inner_loop_count;       // count loops which need alignment
3193   VectorSet _visited;           // Visitation flags
3194   Node_List _tests;             // Set of IfNodes & PCTableNodes
3195 
3196   Final_Reshape_Counts() :
3197     _java_call_count(0), _inner_loop_count(0) { }
3198 
3199   void inc_java_call_count() { _java_call_count++; }
3200   void inc_inner_loop_count() { _inner_loop_count++; }
3201 
3202   int  get_java_call_count() const { return _java_call_count; }
3203   int  get_inner_loop_count() const { return _inner_loop_count; }
3204 };
3205 
3206 //------------------------------final_graph_reshaping_impl----------------------
3207 // Implement items 1-5 from final_graph_reshaping below.
3208 void Compile::final_graph_reshaping_impl(Node *n, Final_Reshape_Counts& frc, Unique_Node_List& dead_nodes) {
3209 
3210   if ( n->outcnt() == 0 ) return; // dead node
3211   uint nop = n->Opcode();
3212 
3213   // Check for 2-input instruction with "last use" on right input.
3214   // Swap to left input.  Implements item (2).
3215   if( n->req() == 3 &&          // two-input instruction
3216       n->in(1)->outcnt() > 1 && // left use is NOT a last use
3217       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
3218       n->in(2)->outcnt() == 1 &&// right use IS a last use
3219       !n->in(2)->is_Con() ) {   // right use is not a constant
3220     // Check for commutative opcode
3221     switch( nop ) {
3222     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddHF:  case Op_AddL:
3223     case Op_MaxI:  case Op_MaxL:  case Op_MaxF:  case Op_MaxD:
3224     case Op_MinI:  case Op_MinL:  case Op_MinF:  case Op_MinD:
3225     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulHF:  case Op_MulL:
3226     case Op_AndL:  case Op_XorL:  case Op_OrL:
3227     case Op_AndI:  case Op_XorI:  case Op_OrI: {
3228       // Move "last use" input to left by swapping inputs
3229       n->swap_edges(1, 2);
3230       break;
3231     }
3232     default:
3233       break;
3234     }
3235   }
3236 
3237 #ifdef ASSERT
3238   if( n->is_Mem() ) {
3239     int alias_idx = get_alias_index(n->as_Mem()->adr_type());
3240     assert( n->in(0) != nullptr || alias_idx != Compile::AliasIdxRaw ||
3241             // oop will be recorded in oop map if load crosses safepoint
3242             (n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
3243                               LoadNode::is_immutable_value(n->in(MemNode::Address)))),
3244             "raw memory operations should have control edge");
3245   }
3246   if (n->is_MemBar()) {
3247     MemBarNode* mb = n->as_MemBar();
3248     if (mb->trailing_store() || mb->trailing_load_store()) {
3249       assert(mb->leading_membar()->trailing_membar() == mb, "bad membar pair");
3250       Node* mem = BarrierSet::barrier_set()->barrier_set_c2()->step_over_gc_barrier(mb->in(MemBarNode::Precedent));
3251       assert((mb->trailing_store() && mem->is_Store() && mem->as_Store()->is_release()) ||
3252              (mb->trailing_load_store() && mem->is_LoadStore()), "missing mem op");
3253     } else if (mb->leading()) {
3254       assert(mb->trailing_membar()->leading_membar() == mb, "bad membar pair");
3255     }
3256   }
3257   if (n->is_CallLeafPure()) {
3258     // A pure call whose result projection is unused should have been
3259     // eliminated by CallLeafPureNode::Ideal during IGVN.
3260     assert(n->as_CallLeafPure()->proj_out_or_null(TypeFunc::Parms) != nullptr,
3261            "unused CallLeafPureNode should have been removed before final graph reshaping");
3262   }
3263 #endif
3264   bool gc_handled = BarrierSet::barrier_set()->barrier_set_c2()->final_graph_reshaping(this, n, nop, dead_nodes);
3265   if (!gc_handled) {
3266     final_graph_reshaping_main_switch(n, frc, nop, dead_nodes);
3267   }
3268 
3269   // Collect CFG split points
3270   if (n->is_MultiBranch() && !n->is_RangeCheck()) {
3271     frc._tests.push(n);
3272   }
3273 }
3274 
3275 void Compile::handle_div_mod_op(Node* n, BasicType bt, bool is_unsigned) {
3276   if (!UseDivMod) {
3277     return;
3278   }
3279 
3280   // Check if "a % b" and "a / b" both exist
3281   Node* d = n->find_similar(Op_DivIL(bt, is_unsigned));
3282   if (d == nullptr) {
3283     return;
3284   }
3285 
3286   // Replace them with a fused divmod if supported
3287   if (Matcher::has_match_rule(Op_DivModIL(bt, is_unsigned))) {
3288     DivModNode* divmod = DivModNode::make(n, bt, is_unsigned);
3289     // If the divisor input for a Div (or Mod etc.) is not zero, then the control input of the Div is set to zero.
3290     // It could be that the divisor input is found not zero because its type is narrowed down by a CastII in the
3291     // subgraph for that input. Range check CastIIs are removed during final graph reshape. To preserve the dependency
3292     // carried by a CastII, precedence edges are added to the Div node. We need to transfer the precedence edges to the
3293     // DivMod node so the dependency is not lost.
3294     divmod->add_prec_from(n);
3295     divmod->add_prec_from(d);
3296     d->subsume_by(divmod->first_proj(), this);
3297     n->subsume_by(divmod->second_proj(), this);
3298   } else {
3299     // Replace "a % b" with "a - ((a / b) * b)"
3300     Node* mult = MulNode::make(d, d->in(2), bt);
3301     Node* sub = SubNode::make(d->in(1), mult, bt);
3302     n->subsume_by(sub, this);
3303   }
3304 }
3305 
3306 void Compile::handle_mulhi_mul_op(Node* n, bool is_unsigned) {
3307   const int fused_opcode = is_unsigned ? Op_UMulHiLoL : Op_MulHiLoL;
3308   if (!Matcher::has_match_rule(fused_opcode)) {
3309     return;
3310   }
3311 
3312   Node* mul = n->find_similar(Op_MulL, true);
3313 
3314   if (mul == nullptr) {
3315     return;
3316   }
3317 
3318   MulHiLoLNode* mul_hi_lo = is_unsigned ? static_cast<MulHiLoLNode*>(UMulHiLoLNode::make(n))
3319                                         : MulHiLoLNode::make(n);
3320   mul->subsume_by(mul_hi_lo->first_proj(), this);
3321   n->subsume_by(mul_hi_lo->second_proj(), this);
3322 }
3323 
3324 void Compile::final_graph_reshaping_main_switch(Node* n, Final_Reshape_Counts& frc, uint nop, Unique_Node_List& dead_nodes) {
3325   switch( nop ) {
3326   case Op_Opaque1:              // Remove Opaque Nodes before matching
3327     n->subsume_by(n->in(1), this);
3328     break;
3329   case Op_CallLeafPure: {
3330     // If the pure call is not supported, then lower to a CallLeaf.
3331     if (!Matcher::match_rule_supported(Op_CallLeafPure)) {
3332       CallNode* call = n->as_Call();
3333       CallNode* new_call = new CallLeafNode(call->tf(), call->entry_point(),
3334                                             call->_name, TypeRawPtr::BOTTOM);
3335       new_call->init_req(TypeFunc::Control, call->in(TypeFunc::Control));
3336       new_call->init_req(TypeFunc::I_O, C->top());
3337       new_call->init_req(TypeFunc::Memory, C->top());
3338       new_call->init_req(TypeFunc::ReturnAdr, C->top());
3339       new_call->init_req(TypeFunc::FramePtr, C->top());
3340       for (unsigned int i = TypeFunc::Parms; i < call->tf()->domain()->cnt(); i++) {
3341         new_call->init_req(i, call->in(i));
3342       }
3343       n->subsume_by(new_call, this);
3344     }
3345     break;
3346   }
3347   case Op_CallStaticJava:
3348   case Op_CallJava:
3349   case Op_CallDynamicJava:
3350     frc.inc_java_call_count(); // Count java call site;
3351   case Op_CallRuntime:
3352   case Op_CallLeaf:
3353   case Op_CallLeafVector:
3354   case Op_CallLeafNoFP: {
3355     assert (n->is_Call(), "");
3356     CallNode *call = n->as_Call();
3357     // See if uncommon argument is shared
3358     if (call->is_CallStaticJava() && call->as_CallStaticJava()->_name) {
3359       Node *n = call->in(TypeFunc::Parms);
3360       int nop = n->Opcode();
3361       // Clone shared simple arguments to uncommon calls, item (1).
3362       if (n->outcnt() > 1 &&
3363           !n->is_Proj() &&
3364           nop != Op_CreateEx &&
3365           nop != Op_CheckCastPP &&
3366           nop != Op_DecodeN &&
3367           nop != Op_DecodeNKlass &&
3368           !n->is_Mem() &&
3369           !n->is_Phi()) {
3370         Node *x = n->clone();
3371         call->set_req(TypeFunc::Parms, x);
3372       }
3373     }
3374     break;
3375   }
3376 
3377   // Mem nodes need explicit cases to satisfy assert(!n->is_Mem()) in default.
3378   case Op_StoreF:
3379   case Op_LoadF:
3380   case Op_StoreD:
3381   case Op_LoadD:
3382   case Op_LoadD_unaligned:
3383   case Op_StoreB:
3384   case Op_StoreC:
3385   case Op_StoreI:
3386   case Op_StoreL:
3387   case Op_CompareAndSwapB:
3388   case Op_CompareAndSwapS:
3389   case Op_CompareAndSwapI:
3390   case Op_CompareAndSwapL:
3391   case Op_CompareAndSwapP:
3392   case Op_CompareAndSwapN:
3393   case Op_WeakCompareAndSwapB:
3394   case Op_WeakCompareAndSwapS:
3395   case Op_WeakCompareAndSwapI:
3396   case Op_WeakCompareAndSwapL:
3397   case Op_WeakCompareAndSwapP:
3398   case Op_WeakCompareAndSwapN:
3399   case Op_CompareAndExchangeB:
3400   case Op_CompareAndExchangeS:
3401   case Op_CompareAndExchangeI:
3402   case Op_CompareAndExchangeL:
3403   case Op_CompareAndExchangeP:
3404   case Op_CompareAndExchangeN:
3405   case Op_GetAndAddS:
3406   case Op_GetAndAddB:
3407   case Op_GetAndAddI:
3408   case Op_GetAndAddL:
3409   case Op_GetAndSetS:
3410   case Op_GetAndSetB:
3411   case Op_GetAndSetI:
3412   case Op_GetAndSetL:
3413   case Op_GetAndSetP:
3414   case Op_GetAndSetN:
3415   case Op_StoreP:
3416   case Op_StoreN:
3417   case Op_StoreNKlass:
3418   case Op_LoadB:
3419   case Op_LoadUB:
3420   case Op_LoadUS:
3421   case Op_LoadI:
3422   case Op_LoadKlass:
3423   case Op_LoadNKlass:
3424   case Op_LoadL:
3425   case Op_LoadL_unaligned:
3426   case Op_LoadP:
3427   case Op_LoadN:
3428   case Op_LoadRange:
3429   case Op_LoadS:
3430   case Op_LoadVectorGather:
3431   case Op_StoreVectorScatter:
3432   case Op_LoadVectorGatherMasked:
3433   case Op_StoreVectorScatterMasked:
3434   case Op_LoadVectorMasked:
3435   case Op_StoreVectorMasked:
3436     break;
3437 
3438   case Op_AddP: {               // Assert sane base pointers
3439     Node *addp = n->in(AddPNode::Address);
3440     assert(n->as_AddP()->address_input_has_same_base(), "Base pointers must match (addp %u)", addp->_idx );
3441 #ifdef _LP64
3442     if (addp->Opcode() == Op_ConP &&
3443         addp == n->in(AddPNode::Base) &&
3444         n->in(AddPNode::Offset)->is_Con()) {
3445       // If the transformation of ConP to ConN+DecodeN is beneficial depends
3446       // on the platform and on the compressed oops mode.
3447       // Use addressing with narrow klass to load with offset on x86.
3448       // Some platforms can use the constant pool to load ConP.
3449       // Do this transformation here since IGVN will convert ConN back to ConP.
3450       const Type* t = addp->bottom_type();
3451       bool is_oop   = t->isa_oopptr() != nullptr;
3452       bool is_klass = t->isa_klassptr() != nullptr;
3453 
3454       if ((is_oop   && UseCompressedOops          && Matcher::const_oop_prefer_decode()  ) ||
3455           (is_klass && Matcher::const_klass_prefer_decode() &&
3456            t->isa_klassptr()->exact_klass()->is_in_encoding_range())) {
3457         Node* nn = nullptr;
3458 
3459         int op = is_oop ? Op_ConN : Op_ConNKlass;
3460 
3461         // Look for existing ConN node of the same exact type.
3462         Node* r  = root();
3463         uint cnt = r->outcnt();
3464         for (uint i = 0; i < cnt; i++) {
3465           Node* m = r->raw_out(i);
3466           if (m!= nullptr && m->Opcode() == op &&
3467               m->bottom_type()->make_ptr() == t) {
3468             nn = m;
3469             break;
3470           }
3471         }
3472         if (nn != nullptr) {
3473           // Decode a narrow oop to match address
3474           // [R12 + narrow_oop_reg<<3 + offset]
3475           if (is_oop) {
3476             nn = new DecodeNNode(nn, t);
3477           } else {
3478             nn = new DecodeNKlassNode(nn, t);
3479           }
3480           // Check for succeeding AddP which uses the same Base.
3481           // Otherwise we will run into the assertion above when visiting that guy.
3482           for (uint i = 0; i < n->outcnt(); ++i) {
3483             Node *out_i = n->raw_out(i);
3484             if (out_i && out_i->is_AddP() && out_i->in(AddPNode::Base) == addp) {
3485               out_i->set_req(AddPNode::Base, nn);
3486 #ifdef ASSERT
3487               for (uint j = 0; j < out_i->outcnt(); ++j) {
3488                 Node *out_j = out_i->raw_out(j);
3489                 assert(out_j == nullptr || !out_j->is_AddP() || out_j->in(AddPNode::Base) != addp,
3490                        "more than 2 AddP nodes in a chain (out_j %u)", out_j->_idx);
3491               }
3492 #endif
3493             }
3494           }
3495           n->set_req(AddPNode::Base, nn);
3496           n->set_req(AddPNode::Address, nn);
3497           if (addp->outcnt() == 0) {
3498             addp->disconnect_inputs(this);
3499           }
3500         }
3501       }
3502     }
3503 #endif
3504     break;
3505   }
3506 
3507   case Op_CastPP: {
3508     // Remove CastPP nodes to gain more freedom during scheduling but
3509     // keep the dependency they encode as control or precedence edges
3510     // (if control is set already) on memory operations. Some CastPP
3511     // nodes don't have a control (don't carry a dependency): skip
3512     // those.
3513     if (n->in(0) != nullptr) {
3514       ResourceMark rm;
3515       Unique_Node_List wq;
3516       wq.push(n);
3517 
3518 
3519       // When we remove a CastPP, we need to pin all of its transitive users under the control of
3520       // the removed node. The simplest approach is to pin all of the uses of the removed CastPP,
3521       // but it is overly conservative, as an AddP does not really need pinning. As a result, we
3522       // look through those nodes that do not need pinning and only pin memory access nodes under
3523       // n->in(0).
3524       for (uint next = 0; next < wq.size(); ++next) {
3525         Node *m = wq.at(next);
3526         for (DUIterator_Fast imax, i = m->fast_outs(imax); i < imax; i++) {
3527           Node* use = m->fast_out(i);
3528           int use_op = use->Opcode();
3529           if (use->is_CFG() || use->pinned() ||                               // already pinned at the exact control
3530               use->is_Cmp() || use_op == Op_CastP2X || use_op == Op_Conv2B) { // pure computations
3531             continue;
3532           } else if (use->is_EncodeNarrowPtr() ||        // EncodeP remembers whether its input is nullable, so it must be pinned
3533                      use_op == Op_PartialSubtypeCheck || // This accesses its pointer inputs, so it must depend on them being not-null
3534                      use->is_Mem() || use->is_memory_access_intrinsic()) {
3535             use->ensure_control_or_add_prec(n->in(0));
3536           } else if (use_op == Op_AddP    ||
3537                      use_op == Op_CastPP  || use_op == Op_CheckCastPP  ||
3538                      use_op == Op_CMoveP  || use_op == Op_CMoveN       ||
3539                      use_op == Op_DecodeN || use_op == Op_DecodeNKlass ||
3540                      use_op == Op_VerifyVectorAlignment) {
3541             // Look through use to find memory accesses if use does not need pinning
3542             wq.push(use);
3543           } else {
3544             // Should have handled all kinds of nodes, verify that we do not unexpectedly arrive
3545             // here
3546             assert(false, "unexpected node %s", use->Name());
3547             // Be conservative in product and pin the unexpected use
3548             use->ensure_control_or_add_prec(n->in(0));
3549           }
3550         }
3551       }
3552     }
3553     const bool is_LP64 = LP64_ONLY(true) NOT_LP64(false);
3554     if (is_LP64 && n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
3555       Node* in1 = n->in(1);
3556       const Type* t = n->bottom_type();
3557       Node* new_in1 = in1->clone();
3558       new_in1->as_DecodeN()->set_type(t);
3559 
3560       if (!Matcher::narrow_oop_use_complex_address()) {
3561         //
3562         // x86, ARM and friends can handle 2 adds in addressing mode
3563         // and Matcher can fold a DecodeN node into address by using
3564         // a narrow oop directly and do implicit null check in address:
3565         //
3566         // [R12 + narrow_oop_reg<<3 + offset]
3567         // NullCheck narrow_oop_reg
3568         //
3569         // On other platforms (Sparc) we have to keep new DecodeN node and
3570         // use it to do implicit null check in address:
3571         //
3572         // decode_not_null narrow_oop_reg, base_reg
3573         // [base_reg + offset]
3574         // NullCheck base_reg
3575         //
3576         // Pin the new DecodeN node to non-null path on these platform (Sparc)
3577         // to keep the information to which null check the new DecodeN node
3578         // corresponds to use it as value in implicit_null_check().
3579         //
3580         new_in1->set_req(0, n->in(0));
3581       }
3582 
3583       n->subsume_by(new_in1, this);
3584       if (in1->outcnt() == 0) {
3585         in1->disconnect_inputs(this);
3586       }
3587     } else {
3588       n->subsume_by(n->in(1), this);
3589       if (n->outcnt() == 0) {
3590         n->disconnect_inputs(this);
3591       }
3592     }
3593     break;
3594   }
3595   case Op_CastII: {
3596     n->as_CastII()->remove_range_check_cast(this);
3597     break;
3598   }
3599 #ifdef _LP64
3600   case Op_CmpP:
3601     // Do this transformation here to preserve CmpPNode::sub() and
3602     // other TypePtr related Ideal optimizations (for example, ptr nullness).
3603     if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
3604       Node* in1 = n->in(1);
3605       Node* in2 = n->in(2);
3606       if (!in1->is_DecodeNarrowPtr()) {
3607         in2 = in1;
3608         in1 = n->in(2);
3609       }
3610       assert(in1->is_DecodeNarrowPtr(), "sanity");
3611 
3612       Node* new_in2 = nullptr;
3613       if (in2->is_DecodeNarrowPtr()) {
3614         assert(in2->Opcode() == in1->Opcode(), "must be same node type");
3615         new_in2 = in2->in(1);
3616       } else if (in2->Opcode() == Op_ConP) {
3617         const Type* t = in2->bottom_type();
3618         if (t == TypePtr::NULL_PTR) {
3619           assert(in1->is_DecodeN(), "compare klass to null?");
3620           // Don't convert CmpP null check into CmpN if compressed
3621           // oops implicit null check is not generated.
3622           // This will allow to generate normal oop implicit null check.
3623           if (Matcher::gen_narrow_oop_implicit_null_checks())
3624             new_in2 = ConNode::make(TypeNarrowOop::NULL_PTR);
3625           //
3626           // This transformation together with CastPP transformation above
3627           // will generated code for implicit null checks for compressed oops.
3628           //
3629           // The original code after Optimize()
3630           //
3631           //    LoadN memory, narrow_oop_reg
3632           //    decode narrow_oop_reg, base_reg
3633           //    CmpP base_reg, nullptr
3634           //    CastPP base_reg // NotNull
3635           //    Load [base_reg + offset], val_reg
3636           //
3637           // after these transformations will be
3638           //
3639           //    LoadN memory, narrow_oop_reg
3640           //    CmpN narrow_oop_reg, nullptr
3641           //    decode_not_null narrow_oop_reg, base_reg
3642           //    Load [base_reg + offset], val_reg
3643           //
3644           // and the uncommon path (== nullptr) will use narrow_oop_reg directly
3645           // since narrow oops can be used in debug info now (see the code in
3646           // final_graph_reshaping_walk()).
3647           //
3648           // At the end the code will be matched to
3649           // on x86:
3650           //
3651           //    Load_narrow_oop memory, narrow_oop_reg
3652           //    Load [R12 + narrow_oop_reg<<3 + offset], val_reg
3653           //    NullCheck narrow_oop_reg
3654           //
3655           // and on sparc:
3656           //
3657           //    Load_narrow_oop memory, narrow_oop_reg
3658           //    decode_not_null narrow_oop_reg, base_reg
3659           //    Load [base_reg + offset], val_reg
3660           //    NullCheck base_reg
3661           //
3662         } else if (t->isa_oopptr()) {
3663           new_in2 = ConNode::make(t->make_narrowoop());
3664         } else if (t->isa_klassptr()) {
3665           ciKlass* klass = t->is_klassptr()->exact_klass();
3666           if (klass->is_in_encoding_range()) {
3667             new_in2 = ConNode::make(t->make_narrowklass());
3668           }
3669         }
3670       }
3671       if (new_in2 != nullptr) {
3672         Node* cmpN = new CmpNNode(in1->in(1), new_in2);
3673         n->subsume_by(cmpN, this);
3674         if (in1->outcnt() == 0) {
3675           in1->disconnect_inputs(this);
3676         }
3677         if (in2->outcnt() == 0) {
3678           in2->disconnect_inputs(this);
3679         }
3680       }
3681     }
3682     break;
3683 
3684   case Op_DecodeN:
3685   case Op_DecodeNKlass:
3686     assert(!n->in(1)->is_EncodeNarrowPtr(), "should be optimized out");
3687     // DecodeN could be pinned when it can't be fold into
3688     // an address expression, see the code for Op_CastPP above.
3689     assert(n->in(0) == nullptr || (UseCompressedOops && !Matcher::narrow_oop_use_complex_address()), "no control");
3690     break;
3691 
3692   case Op_EncodeP:
3693   case Op_EncodePKlass: {
3694     Node* in1 = n->in(1);
3695     if (in1->is_DecodeNarrowPtr()) {
3696       n->subsume_by(in1->in(1), this);
3697     } else if (in1->Opcode() == Op_ConP) {
3698       const Type* t = in1->bottom_type();
3699       if (t == TypePtr::NULL_PTR) {
3700         assert(t->isa_oopptr(), "null klass?");
3701         n->subsume_by(ConNode::make(TypeNarrowOop::NULL_PTR), this);
3702       } else if (t->isa_oopptr()) {
3703         n->subsume_by(ConNode::make(t->make_narrowoop()), this);
3704       } else if (t->isa_klassptr()) {
3705         ciKlass* klass = t->is_klassptr()->exact_klass();
3706         if (klass->is_in_encoding_range()) {
3707           n->subsume_by(ConNode::make(t->make_narrowklass()), this);
3708         } else {
3709           assert(false, "unencodable klass in ConP -> EncodeP");
3710           C->record_failure("unencodable klass in ConP -> EncodeP");
3711         }
3712       }
3713     }
3714     if (in1->outcnt() == 0) {
3715       in1->disconnect_inputs(this);
3716     }
3717     break;
3718   }
3719 
3720   case Op_Proj: {
3721     if (OptimizeStringConcat || IncrementalInline) {
3722       ProjNode* proj = n->as_Proj();
3723       if (proj->_is_io_use) {
3724         assert(proj->_con == TypeFunc::I_O || proj->_con == TypeFunc::Memory, "");
3725         // Separate projections were used for the exception path which
3726         // are normally removed by a late inline.  If it wasn't inlined
3727         // then they will hang around and should just be replaced with
3728         // the original one. Merge them.
3729         Node* non_io_proj = proj->in(0)->as_Multi()->proj_out_or_null(proj->_con, false /*is_io_use*/);
3730         if (non_io_proj  != nullptr) {
3731           proj->subsume_by(non_io_proj , this);
3732         }
3733       }
3734     }
3735     break;
3736   }
3737 
3738   case Op_Phi:
3739     if (n->as_Phi()->bottom_type()->isa_narrowoop() || n->as_Phi()->bottom_type()->isa_narrowklass()) {
3740       // The EncodeP optimization may create Phi with the same edges
3741       // for all paths. It is not handled well by Register Allocator.
3742       Node* unique_in = n->in(1);
3743       assert(unique_in != nullptr, "");
3744       uint cnt = n->req();
3745       for (uint i = 2; i < cnt; i++) {
3746         Node* m = n->in(i);
3747         assert(m != nullptr, "");
3748         if (unique_in != m)
3749           unique_in = nullptr;
3750       }
3751       if (unique_in != nullptr) {
3752         n->subsume_by(unique_in, this);
3753       }
3754     }
3755     break;
3756 
3757 #endif
3758 
3759   case Op_ModI:
3760     handle_div_mod_op(n, T_INT, false);
3761     break;
3762 
3763   case Op_ModL:
3764     handle_div_mod_op(n, T_LONG, false);
3765     break;
3766 
3767   case Op_UModI:
3768     handle_div_mod_op(n, T_INT, true);
3769     break;
3770 
3771   case Op_UModL:
3772     handle_div_mod_op(n, T_LONG, true);
3773     break;
3774 
3775   case Op_MulHiL:
3776     handle_mulhi_mul_op(n, false);
3777     break;
3778 
3779   case Op_UMulHiL:
3780     handle_mulhi_mul_op(n, true);
3781     break;
3782 
3783   case Op_LoadVector:
3784   case Op_StoreVector:
3785 #ifdef ASSERT
3786     // Add VerifyVectorAlignment node between adr and load / store.
3787     if (VerifyAlignVector && Matcher::has_match_rule(Op_VerifyVectorAlignment)) {
3788       bool must_verify_alignment = n->is_LoadVector() ? n->as_LoadVector()->must_verify_alignment() :
3789                                                         n->as_StoreVector()->must_verify_alignment();
3790       if (must_verify_alignment) {
3791         jlong vector_width = n->is_LoadVector() ? n->as_LoadVector()->memory_size() :
3792                                                   n->as_StoreVector()->memory_size();
3793         // The memory access should be aligned to the vector width in bytes.
3794         // However, the underlying array is possibly less well aligned, but at least
3795         // to ObjectAlignmentInBytes. Hence, even if multiple arrays are accessed in
3796         // a loop we can expect at least the following alignment:
3797         jlong guaranteed_alignment = MIN2(vector_width, (jlong)ObjectAlignmentInBytes);
3798         assert(2 <= guaranteed_alignment && guaranteed_alignment <= 64, "alignment must be in range");
3799         assert(is_power_of_2(guaranteed_alignment), "alignment must be power of 2");
3800         // Create mask from alignment. e.g. 0b1000 -> 0b0111
3801         jlong mask = guaranteed_alignment - 1;
3802         Node* mask_con = ConLNode::make(mask);
3803         VerifyVectorAlignmentNode* va = new VerifyVectorAlignmentNode(n->in(MemNode::Address), mask_con);
3804         n->set_req(MemNode::Address, va);
3805       }
3806     }
3807 #endif
3808     break;
3809 
3810   case Op_PackB:
3811   case Op_PackS:
3812   case Op_PackI:
3813   case Op_PackF:
3814   case Op_PackL:
3815   case Op_PackD:
3816     if (n->req()-1 > 2) {
3817       // Replace many operand PackNodes with a binary tree for matching
3818       PackNode* p = (PackNode*) n;
3819       Node* btp = p->binary_tree_pack(1, n->req());
3820       n->subsume_by(btp, this);
3821     }
3822     break;
3823   case Op_Loop:
3824     // When StressCountedLoop is enabled, this loop may intentionally avoid a counted loop conversion.
3825     // This is expected behavior for the stress mode, which exercises alternative compilation paths.
3826     if (!StressCountedLoop) {
3827       assert(!n->as_Loop()->is_loop_nest_inner_loop() || _loop_opts_cnt == 0, "should have been turned into a counted loop");
3828     }
3829   case Op_CountedLoop:
3830   case Op_LongCountedLoop:
3831   case Op_OuterStripMinedLoop:
3832     if (n->as_Loop()->is_inner_loop()) {
3833       frc.inc_inner_loop_count();
3834     }
3835     n->as_Loop()->verify_strip_mined(0);
3836     break;
3837   case Op_LShiftI:
3838   case Op_RShiftI:
3839   case Op_URShiftI:
3840   case Op_LShiftL:
3841   case Op_RShiftL:
3842   case Op_URShiftL:
3843     if (Matcher::need_masked_shift_count) {
3844       // The cpu's shift instructions don't restrict the count to the
3845       // lower 5/6 bits. We need to do the masking ourselves.
3846       Node* in2 = n->in(2);
3847       juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
3848       const TypeInt* t = in2->find_int_type();
3849       if (t != nullptr && t->is_con()) {
3850         juint shift = t->get_con();
3851         if (shift > mask) { // Unsigned cmp
3852           n->set_req(2, ConNode::make(TypeInt::make(shift & mask)));
3853         }
3854       } else {
3855         if (t == nullptr || t->_lo < 0 || t->_hi > (int)mask) {
3856           Node* shift = new AndINode(in2, ConNode::make(TypeInt::make(mask)));
3857           n->set_req(2, shift);
3858         }
3859       }
3860       if (in2->outcnt() == 0) { // Remove dead node
3861         in2->disconnect_inputs(this);
3862       }
3863     }
3864     break;
3865   case Op_MemBarStoreStore:
3866   case Op_MemBarRelease:
3867     // Break the link with AllocateNode: it is no longer useful and
3868     // confuses register allocation.
3869     if (n->req() > MemBarNode::Precedent) {
3870       n->set_req(MemBarNode::Precedent, top());
3871     }
3872     break;
3873   case Op_MemBarAcquire: {
3874     if (n->as_MemBar()->trailing_load() && n->req() > MemBarNode::Precedent) {
3875       // At parse time, the trailing MemBarAcquire for a volatile load
3876       // is created with an edge to the load. After optimizations,
3877       // that input may be a chain of Phis. If those phis have no
3878       // other use, then the MemBarAcquire keeps them alive and
3879       // register allocation can be confused.
3880       dead_nodes.push(n->in(MemBarNode::Precedent));
3881       n->set_req(MemBarNode::Precedent, top());
3882     }
3883     break;
3884   }
3885   case Op_RangeCheck: {
3886     RangeCheckNode* rc = n->as_RangeCheck();
3887     Node* iff = new IfNode(rc->in(0), rc->in(1), rc->_prob, rc->_fcnt);
3888     n->subsume_by(iff, this);
3889     frc._tests.push(iff);
3890     break;
3891   }
3892   case Op_ConvI2L: {
3893     if (!Matcher::convi2l_type_required) {
3894       // Code generation on some platforms doesn't need accurate
3895       // ConvI2L types. Widening the type can help remove redundant
3896       // address computations.
3897       n->as_Type()->set_type(TypeLong::INT);
3898       ResourceMark rm;
3899       Unique_Node_List wq;
3900       wq.push(n);
3901       for (uint next = 0; next < wq.size(); next++) {
3902         Node *m = wq.at(next);
3903 
3904         for(;;) {
3905           // Loop over all nodes with identical inputs edges as m
3906           Node* k = m->find_similar(m->Opcode());
3907           if (k == nullptr) {
3908             break;
3909           }
3910           // Push their uses so we get a chance to remove node made
3911           // redundant
3912           for (DUIterator_Fast imax, i = k->fast_outs(imax); i < imax; i++) {
3913             Node* u = k->fast_out(i);
3914             if (u->Opcode() == Op_LShiftL ||
3915                 u->Opcode() == Op_AddL ||
3916                 u->Opcode() == Op_SubL ||
3917                 u->Opcode() == Op_AddP) {
3918               wq.push(u);
3919             }
3920           }
3921           // Replace all nodes with identical edges as m with m
3922           k->subsume_by(m, this);
3923         }
3924       }
3925     }
3926     break;
3927   }
3928   case Op_CmpUL: {
3929     if (!Matcher::has_match_rule(Op_CmpUL)) {
3930       // No support for unsigned long comparisons
3931       ConINode* sign_pos = new ConINode(TypeInt::make(BitsPerLong - 1));
3932       Node* sign_bit_mask = new RShiftLNode(n->in(1), sign_pos);
3933       Node* orl = new OrLNode(n->in(1), sign_bit_mask);
3934       ConLNode* remove_sign_mask = new ConLNode(TypeLong::make(max_jlong));
3935       Node* andl = new AndLNode(orl, remove_sign_mask);
3936       Node* cmp = new CmpLNode(andl, n->in(2));
3937       n->subsume_by(cmp, this);
3938     }
3939     break;
3940   }
3941 #ifdef ASSERT
3942   case Op_ConNKlass: {
3943     const TypePtr* tp = n->as_Type()->type()->make_ptr();
3944     ciKlass* klass = tp->is_klassptr()->exact_klass();
3945     assert(klass->is_in_encoding_range(), "klass cannot be compressed");
3946     break;
3947   }
3948 #endif
3949   case Op_DeadPath: {
3950     // The CFG inputs are dead paths. Replace the DeadPath with a Region and insert a Halt node.
3951     assert(n->req() > 1, "why not removed if no input other than itself?");
3952     RegionNode* r = new RegionNode(n->req());
3953     for (uint i = 1; i < n->req(); ++i) {
3954       r->set_req(i, n->in(i));
3955     }
3956     n->disconnect_inputs(this);
3957     Node* frame = start()->proj_out(TypeFunc::FramePtr);
3958     stringStream ss;
3959     ss.print("dead path discovered by data nodes during igvn");
3960     Node* halt = new HaltNode(r, frame, ss.as_string(comp_arena()));
3961     root()->set_req(root()->find_edge(n), halt);
3962     break;
3963   }
3964   default:
3965     assert(!n->is_Call(), "");
3966     assert(!n->is_Mem(), "");
3967     assert(nop != Op_ProfileBoolean, "should be eliminated during IGVN");
3968     break;
3969   }
3970 }
3971 
3972 //------------------------------final_graph_reshaping_walk---------------------
3973 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
3974 // requires that the walk visits a node's inputs before visiting the node.
3975 void Compile::final_graph_reshaping_walk(Node_Stack& nstack, Node* root, Final_Reshape_Counts& frc, Unique_Node_List& dead_nodes) {
3976   Unique_Node_List sfpt;
3977 
3978   frc._visited.set(root->_idx); // first, mark node as visited
3979   uint cnt = root->req();
3980   Node *n = root;
3981   uint  i = 0;
3982   while (true) {
3983     if (i < cnt) {
3984       // Place all non-visited non-null inputs onto stack
3985       Node* m = n->in(i);
3986       ++i;
3987       if (m != nullptr && !frc._visited.test_set(m->_idx)) {
3988         if (m->is_SafePoint() && m->as_SafePoint()->jvms() != nullptr) {
3989           // compute worst case interpreter size in case of a deoptimization
3990           update_interpreter_frame_size(m->as_SafePoint()->jvms()->interpreter_frame_size());
3991 
3992           sfpt.push(m);
3993         }
3994         cnt = m->req();
3995         nstack.push(n, i); // put on stack parent and next input's index
3996         n = m;
3997         i = 0;
3998       }
3999     } else {
4000       // Now do post-visit work
4001       final_graph_reshaping_impl(n, frc, dead_nodes);
4002       if (nstack.is_empty())
4003         break;             // finished
4004       n = nstack.node();   // Get node from stack
4005       cnt = n->req();
4006       i = nstack.index();
4007       nstack.pop();        // Shift to the next node on stack
4008     }
4009   }
4010 
4011   expand_reachability_edges(sfpt);
4012 
4013   // Skip next transformation if compressed oops are not used.
4014   if (UseCompressedOops && !Matcher::gen_narrow_oop_implicit_null_checks())
4015     return;
4016 
4017   // Go over ReachabilityFence nodes to skip DecodeN nodes for referents.
4018   // The sole purpose of RF node is to keep the referent oop alive and
4019   // decoding the oop for that is not needed.
4020   for (int i = 0; i < C->reachability_fences_count(); i++) {
4021     ReachabilityFenceNode* rf = C->reachability_fence(i);
4022     DecodeNNode* dn = rf->in(1)->isa_DecodeN();
4023     if (dn != nullptr) {
4024       if (!dn->has_non_debug_uses() || Matcher::narrow_oop_use_complex_address()) {
4025         rf->set_req(1, dn->in(1));
4026         if (dn->outcnt() == 0) {
4027           dn->disconnect_inputs(this);
4028         }
4029       }
4030     }
4031   }
4032 
4033   // Go over safepoints nodes to skip DecodeN/DecodeNKlass nodes for debug edges.
4034   // It could be done for an uncommon traps or any safepoints/calls
4035   // if the DecodeN/DecodeNKlass node is referenced only in a debug info.
4036   while (sfpt.size() > 0) {
4037     n = sfpt.pop();
4038     JVMState *jvms = n->as_SafePoint()->jvms();
4039     assert(jvms != nullptr, "sanity");
4040     int start = jvms->debug_start();
4041     int end   = n->req();
4042     bool is_uncommon = (n->is_CallStaticJava() &&
4043                         n->as_CallStaticJava()->uncommon_trap_request() != 0);
4044     for (int j = start; j < end; j++) {
4045       Node* in = n->in(j);
4046       if (in->is_DecodeNarrowPtr() && (is_uncommon || !in->has_non_debug_uses())) {
4047         n->set_req(j, in->in(1));
4048         if (in->outcnt() == 0) {
4049           in->disconnect_inputs(this);
4050         }
4051       }
4052     }
4053   }
4054 }
4055 
4056 //------------------------------final_graph_reshaping--------------------------
4057 // Final Graph Reshaping.
4058 //
4059 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
4060 //     and not commoned up and forced early.  Must come after regular
4061 //     optimizations to avoid GVN undoing the cloning.  Clone constant
4062 //     inputs to Loop Phis; these will be split by the allocator anyways.
4063 //     Remove Opaque nodes.
4064 // (2) Move last-uses by commutative operations to the left input to encourage
4065 //     Intel update-in-place two-address operations and better register usage
4066 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
4067 //     calls canonicalizing them back.
4068 // (3) Detect infinite loops; blobs of code reachable from above but not
4069 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
4070 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
4071 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
4072 //     Detection is by looking for IfNodes where only 1 projection is
4073 //     reachable from below or CatchNodes missing some targets.
4074 // (4) Assert for insane oop offsets in debug mode.
4075 
4076 bool Compile::final_graph_reshaping() {
4077   // an infinite loop may have been eliminated by the optimizer,
4078   // in which case the graph will be empty.
4079   if (root()->req() == 1) {
4080     // Do not compile method that is only a trivial infinite loop,
4081     // since the content of the loop may have been eliminated.
4082     record_method_not_compilable("trivial infinite loop");
4083     return true;
4084   }
4085 
4086   // Expensive nodes have their control input set to prevent the GVN
4087   // from freely commoning them. There's no GVN beyond this point so
4088   // no need to keep the control input. We want the expensive nodes to
4089   // be freely moved to the least frequent code path by gcm.
4090   assert(OptimizeExpensiveOps || expensive_count() == 0, "optimization off but list non empty?");
4091   for (int i = 0; i < expensive_count(); i++) {
4092     _expensive_nodes.at(i)->set_req(0, nullptr);
4093   }
4094 
4095   Final_Reshape_Counts frc;
4096 
4097   // Visit everybody reachable!
4098   // Allocate stack of size C->live_nodes()/2 to avoid frequent realloc
4099   Node_Stack nstack(live_nodes() >> 1);
4100   Unique_Node_List dead_nodes;
4101   final_graph_reshaping_walk(nstack, root(), frc, dead_nodes);
4102 
4103   // Check for unreachable (from below) code (i.e., infinite loops).
4104   for( uint i = 0; i < frc._tests.size(); i++ ) {
4105     MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
4106     // Get number of CFG targets.
4107     // Note that PCTables include exception targets after calls.
4108     uint required_outcnt = n->required_outcnt();
4109     if (n->outcnt() != required_outcnt) {
4110       // Check for a few special cases.  Rethrow Nodes never take the
4111       // 'fall-thru' path, so expected kids is 1 less.
4112       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
4113         if (n->in(0)->in(0)->is_Call()) {
4114           CallNode* call = n->in(0)->in(0)->as_Call();
4115           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
4116             required_outcnt--;      // Rethrow always has 1 less kid
4117           } else if (call->req() > TypeFunc::Parms &&
4118                      call->is_CallDynamicJava()) {
4119             // Check for null receiver. In such case, the optimizer has
4120             // detected that the virtual call will always result in a null
4121             // pointer exception. The fall-through projection of this CatchNode
4122             // will not be populated.
4123             Node* arg0 = call->in(TypeFunc::Parms);
4124             if (arg0->is_Type() &&
4125                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
4126               required_outcnt--;
4127             }
4128           } else if (call->entry_point() == OptoRuntime::new_array_Java() ||
4129                      call->entry_point() == OptoRuntime::new_array_nozero_Java()) {
4130             // Check for illegal array length. In such case, the optimizer has
4131             // detected that the allocation attempt will always result in an
4132             // exception. There is no fall-through projection of this CatchNode .
4133             assert(call->is_CallStaticJava(), "static call expected");
4134             assert(call->req() == call->jvms()->endoff() + 1, "missing extra input");
4135             uint valid_length_test_input = call->req() - 1;
4136             Node* valid_length_test = call->in(valid_length_test_input);
4137             call->del_req(valid_length_test_input);
4138             if (valid_length_test->find_int_con(1) == 0) {
4139               required_outcnt--;
4140             }
4141             dead_nodes.push(valid_length_test);
4142             assert(n->outcnt() == required_outcnt, "malformed control flow");
4143             continue;
4144           }
4145         }
4146       }
4147 
4148       // Recheck with a better notion of 'required_outcnt'
4149       if (n->outcnt() != required_outcnt) {
4150         record_method_not_compilable("malformed control flow");
4151         return true;            // Not all targets reachable!
4152       }
4153     } else if (n->is_PCTable() && n->in(0) && n->in(0)->in(0) && n->in(0)->in(0)->is_Call()) {
4154       CallNode* call = n->in(0)->in(0)->as_Call();
4155       if (call->entry_point() == OptoRuntime::new_array_Java() ||
4156           call->entry_point() == OptoRuntime::new_array_nozero_Java()) {
4157         assert(call->is_CallStaticJava(), "static call expected");
4158         assert(call->req() == call->jvms()->endoff() + 1, "missing extra input");
4159         uint valid_length_test_input = call->req() - 1;
4160         dead_nodes.push(call->in(valid_length_test_input));
4161         call->del_req(valid_length_test_input); // valid length test useless now
4162       }
4163     }
4164     // Check that I actually visited all kids.  Unreached kids
4165     // must be infinite loops.
4166     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
4167       if (!frc._visited.test(n->fast_out(j)->_idx)) {
4168         record_method_not_compilable("infinite loop");
4169         return true;            // Found unvisited kid; must be unreach
4170       }
4171 
4172     // Here so verification code in final_graph_reshaping_walk()
4173     // always see an OuterStripMinedLoopEnd
4174     if (n->is_OuterStripMinedLoopEnd() || n->is_LongCountedLoopEnd()) {
4175       IfNode* init_iff = n->as_If();
4176       Node* iff = new IfNode(init_iff->in(0), init_iff->in(1), init_iff->_prob, init_iff->_fcnt);
4177       n->subsume_by(iff, this);
4178     }
4179   }
4180 
4181   while (dead_nodes.size() > 0) {
4182     Node* m = dead_nodes.pop();
4183     if (m->outcnt() == 0 && m != top()) {
4184       for (uint j = 0; j < m->req(); j++) {
4185         Node* in = m->in(j);
4186         if (in != nullptr) {
4187           dead_nodes.push(in);
4188         }
4189       }
4190       m->disconnect_inputs(this);
4191     }
4192   }
4193 
4194   set_java_calls(frc.get_java_call_count());
4195   set_inner_loops(frc.get_inner_loop_count());
4196 
4197   // No infinite loops, no reason to bail out.
4198   return false;
4199 }
4200 
4201 //-----------------------------too_many_traps----------------------------------
4202 // Report if there are too many traps at the current method and bci.
4203 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
4204 bool Compile::too_many_traps(ciMethod* method,
4205                              int bci,
4206                              Deoptimization::DeoptReason reason) {
4207   ciMethodData* md = method->method_data();
4208   if (md->is_empty()) {
4209     // Assume the trap has not occurred, or that it occurred only
4210     // because of a transient condition during start-up in the interpreter.
4211     return false;
4212   }
4213   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : nullptr;
4214   if (md->has_trap_at(bci, m, reason) != 0) {
4215     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
4216     // Also, if there are multiple reasons, or if there is no per-BCI record,
4217     // assume the worst.
4218     if (log())
4219       log()->elem("observe trap='%s' count='%d'",
4220                   Deoptimization::trap_reason_name(reason),
4221                   md->trap_count(reason));
4222     return true;
4223   } else {
4224     // Ignore method/bci and see if there have been too many globally.
4225     return too_many_traps(reason, md);
4226   }
4227 }
4228 
4229 // Less-accurate variant which does not require a method and bci.
4230 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
4231                              ciMethodData* logmd) {
4232   if (trap_count(reason) >= Deoptimization::per_method_trap_limit(reason)) {
4233     // Too many traps globally.
4234     // Note that we use cumulative trap_count, not just md->trap_count.
4235     if (log()) {
4236       int mcount = (logmd == nullptr)? -1: (int)logmd->trap_count(reason);
4237       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
4238                   Deoptimization::trap_reason_name(reason),
4239                   mcount, trap_count(reason));
4240     }
4241     return true;
4242   } else {
4243     // The coast is clear.
4244     return false;
4245   }
4246 }
4247 
4248 //--------------------------too_many_recompiles--------------------------------
4249 // Report if there are too many recompiles at the current method and bci.
4250 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
4251 // Is not eager to return true, since this will cause the compiler to use
4252 // Action_none for a trap point, to avoid too many recompilations.
4253 bool Compile::too_many_recompiles(ciMethod* method,
4254                                   int bci,
4255                                   Deoptimization::DeoptReason reason) {
4256   ciMethodData* md = method->method_data();
4257   if (md->is_empty()) {
4258     // Assume the trap has not occurred, or that it occurred only
4259     // because of a transient condition during start-up in the interpreter.
4260     return false;
4261   }
4262   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
4263   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
4264   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
4265   Deoptimization::DeoptReason per_bc_reason
4266     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
4267   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : nullptr;
4268   if ((per_bc_reason == Deoptimization::Reason_none
4269        || md->has_trap_at(bci, m, reason) != 0)
4270       // The trap frequency measure we care about is the recompile count:
4271       && md->trap_recompiled_at(bci, m)
4272       && md->overflow_recompile_count() >= bc_cutoff) {
4273     // Do not emit a trap here if it has already caused recompilations.
4274     // Also, if there are multiple reasons, or if there is no per-BCI record,
4275     // assume the worst.
4276     if (log())
4277       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
4278                   Deoptimization::trap_reason_name(reason),
4279                   md->trap_count(reason),
4280                   md->overflow_recompile_count());
4281     return true;
4282   } else if (trap_count(reason) != 0
4283              && decompile_count() >= m_cutoff) {
4284     // Too many recompiles globally, and we have seen this sort of trap.
4285     // Use cumulative decompile_count, not just md->decompile_count.
4286     if (log())
4287       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
4288                   Deoptimization::trap_reason_name(reason),
4289                   md->trap_count(reason), trap_count(reason),
4290                   md->decompile_count(), decompile_count());
4291     return true;
4292   } else {
4293     // The coast is clear.
4294     return false;
4295   }
4296 }
4297 
4298 // Compute when not to trap. Used by matching trap based nodes and
4299 // NullCheck optimization.
4300 void Compile::set_allowed_deopt_reasons() {
4301   _allowed_reasons = 0;
4302   if (is_method_compilation()) {
4303     for (int rs = (int)Deoptimization::Reason_none+1; rs < Compile::trapHistLength; rs++) {
4304       assert(rs < BitsPerInt, "recode bit map");
4305       if (!too_many_traps((Deoptimization::DeoptReason) rs)) {
4306         _allowed_reasons |= nth_bit(rs);
4307       }
4308     }
4309   }
4310 }
4311 
4312 bool Compile::needs_clinit_barrier(ciMethod* method, ciMethod* accessing_method) {
4313   return method->is_static() && needs_clinit_barrier(method->holder(), accessing_method);
4314 }
4315 
4316 bool Compile::needs_clinit_barrier(ciField* field, ciMethod* accessing_method) {
4317   return field->is_static() && needs_clinit_barrier(field->holder(), accessing_method);
4318 }
4319 
4320 bool Compile::needs_clinit_barrier(ciInstanceKlass* holder, ciMethod* accessing_method) {
4321   if (holder->is_initialized()) {
4322     return false;
4323   }
4324   if (holder->is_being_initialized()) {
4325     if (accessing_method->holder() == holder) {
4326       // Access inside a class. The barrier can be elided when access happens in <clinit>,
4327       // <init>, or a static method. In all those cases, there was an initialization
4328       // barrier on the holder klass passed.
4329       if (accessing_method->is_static_initializer() ||
4330           accessing_method->is_object_initializer() ||
4331           accessing_method->is_static()) {
4332         return false;
4333       }
4334     } else if (accessing_method->holder()->is_subclass_of(holder)) {
4335       // Access from a subclass. The barrier can be elided only when access happens in <clinit>.
4336       // In case of <init> or a static method, the barrier is on the subclass is not enough:
4337       // child class can become fully initialized while its parent class is still being initialized.
4338       if (accessing_method->is_static_initializer()) {
4339         return false;
4340       }
4341     }
4342     ciMethod* root = method(); // the root method of compilation
4343     if (root != accessing_method) {
4344       return needs_clinit_barrier(holder, root); // check access in the context of compilation root
4345     }
4346   }
4347   return true;
4348 }
4349 
4350 #ifndef PRODUCT
4351 //------------------------------verify_bidirectional_edges---------------------
4352 // For each input edge to a node (ie - for each Use-Def edge), verify that
4353 // there is a corresponding Def-Use edge.
4354 void Compile::verify_bidirectional_edges(Unique_Node_List& visited, const Unique_Node_List* root_and_safepoints) const {
4355   // Allocate stack of size C->live_nodes()/16 to avoid frequent realloc
4356   uint stack_size = live_nodes() >> 4;
4357   Node_List nstack(MAX2(stack_size, (uint) OptoNodeListSize));
4358   if (root_and_safepoints != nullptr) {
4359     assert(root_and_safepoints->member(_root), "root is not in root_and_safepoints");
4360     for (uint i = 0, limit = root_and_safepoints->size(); i < limit; i++) {
4361       Node* root_or_safepoint = root_and_safepoints->at(i);
4362       // If the node is a safepoint, let's check if it still has a control input
4363       // Lack of control input signifies that this node was killed by CCP or
4364       // recursively by remove_globally_dead_node and it shouldn't be a starting
4365       // point.
4366       if (!root_or_safepoint->is_SafePoint() || root_or_safepoint->in(0) != nullptr) {
4367         nstack.push(root_or_safepoint);
4368       }
4369     }
4370   } else {
4371     nstack.push(_root);
4372   }
4373 
4374   while (nstack.size() > 0) {
4375     Node* n = nstack.pop();
4376     if (visited.member(n)) {
4377       continue;
4378     }
4379     visited.push(n);
4380 
4381     // Walk over all input edges, checking for correspondence
4382     uint length = n->len();
4383     for (uint i = 0; i < length; i++) {
4384       Node* in = n->in(i);
4385       if (in != nullptr && !visited.member(in)) {
4386         nstack.push(in); // Put it on stack
4387       }
4388       if (in != nullptr && !in->is_top()) {
4389         // Count instances of `next`
4390         int cnt = 0;
4391         for (uint idx = 0; idx < in->_outcnt; idx++) {
4392           if (in->_out[idx] == n) {
4393             cnt++;
4394           }
4395         }
4396         assert(cnt > 0, "Failed to find Def-Use edge.");
4397         // Check for duplicate edges
4398         // walk the input array downcounting the input edges to n
4399         for (uint j = 0; j < length; j++) {
4400           if (n->in(j) == in) {
4401             cnt--;
4402           }
4403         }
4404         assert(cnt == 0, "Mismatched edge count.");
4405       } else if (in == nullptr) {
4406         assert(i == 0 || i >= n->req() ||
4407                n->is_Region() || n->is_Phi() || n->is_ArrayCopy() ||
4408                (n->is_Unlock() && i == (n->req() - 1)) ||
4409                (n->is_MemBar() && i == 5), // the precedence edge to a membar can be removed during macro node expansion
4410               "only region, phi, arraycopy, unlock or membar nodes have null data edges");
4411       } else {
4412         assert(in->is_top(), "sanity");
4413         // Nothing to check.
4414       }
4415     }
4416   }
4417 }
4418 
4419 //------------------------------verify_graph_edges---------------------------
4420 // Walk the Graph and verify that there is a one-to-one correspondence
4421 // between Use-Def edges and Def-Use edges in the graph.
4422 void Compile::verify_graph_edges(bool no_dead_code, const Unique_Node_List* root_and_safepoints) const {
4423   if (VerifyGraphEdges) {
4424     Unique_Node_List visited;
4425 
4426     // Call graph walk to check edges
4427     verify_bidirectional_edges(visited, root_and_safepoints);
4428     if (no_dead_code) {
4429       // Now make sure that no visited node is used by an unvisited node.
4430       bool dead_nodes = false;
4431       Unique_Node_List checked;
4432       while (visited.size() > 0) {
4433         Node* n = visited.pop();
4434         checked.push(n);
4435         for (uint i = 0; i < n->outcnt(); i++) {
4436           Node* use = n->raw_out(i);
4437           if (checked.member(use))  continue;  // already checked
4438           if (visited.member(use))  continue;  // already in the graph
4439           if (use->is_Con())        continue;  // a dead ConNode is OK
4440           // At this point, we have found a dead node which is DU-reachable.
4441           if (!dead_nodes) {
4442             tty->print_cr("*** Dead nodes reachable via DU edges:");
4443             dead_nodes = true;
4444           }
4445           use->dump(2);
4446           tty->print_cr("---");
4447           checked.push(use);  // No repeats; pretend it is now checked.
4448         }
4449       }
4450       assert(!dead_nodes, "using nodes must be reachable from root");
4451     }
4452   }
4453 }
4454 #endif
4455 
4456 // The Compile object keeps track of failure reasons separately from the ciEnv.
4457 // This is required because there is not quite a 1-1 relation between the
4458 // ciEnv and its compilation task and the Compile object.  Note that one
4459 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
4460 // to backtrack and retry without subsuming loads.  Other than this backtracking
4461 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
4462 // by the logic in C2Compiler.
4463 void Compile::record_failure(const char* reason DEBUG_ONLY(COMMA bool allow_multiple_failures)) {
4464   if (log() != nullptr) {
4465     log()->elem("failure reason='%s' phase='compile'", reason);
4466   }
4467   if (_failure_reason.get() == nullptr) {
4468     // Record the first failure reason.
4469     _failure_reason.set(reason);
4470     if (CaptureBailoutInformation) {
4471       _first_failure_details = new CompilationFailureInfo(reason);
4472     }
4473   } else {
4474     assert(!StressBailout || allow_multiple_failures, "should have handled previous failure.");
4475   }
4476 
4477   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
4478     C->print_method(PHASE_FAILURE, 1);
4479   }
4480   _root = nullptr;  // flush the graph, too
4481 }
4482 
4483 Compile::TracePhase::TracePhase(const char* name, PhaseTraceId id)
4484   : TraceTime(name, &Phase::timers[id], CITime, CITimeVerbose),
4485     _compile(Compile::current()),
4486     _log(nullptr),
4487     _dolog(CITimeVerbose)
4488 {
4489   assert(_compile != nullptr, "sanity check");
4490   assert(id != PhaseTraceId::_t_none, "Don't use none");
4491   if (_dolog) {
4492     _log = _compile->log();
4493   }
4494   if (_log != nullptr) {
4495     _log->begin_head("phase name='%s' nodes='%d' live='%d'", phase_name(), _compile->unique(), _compile->live_nodes());
4496     _log->stamp();
4497     _log->end_head();
4498   }
4499 
4500   // Inform memory statistic, if enabled
4501   if (CompilationMemoryStatistic::enabled()) {
4502     CompilationMemoryStatistic::on_phase_start((int)id, name);
4503   }
4504 }
4505 
4506 Compile::TracePhase::TracePhase(PhaseTraceId id)
4507   : TracePhase(Phase::get_phase_trace_id_text(id), id) {}
4508 
4509 Compile::TracePhase::~TracePhase() {
4510 
4511   // Inform memory statistic, if enabled
4512   if (CompilationMemoryStatistic::enabled()) {
4513     CompilationMemoryStatistic::on_phase_end();
4514   }
4515 
4516   if (_compile->failing_internal()) {
4517     if (_log != nullptr) {
4518       _log->done("phase");
4519     }
4520     return; // timing code, not stressing bailouts.
4521   }
4522 #ifdef ASSERT
4523   if (PrintIdealNodeCount) {
4524     tty->print_cr("phase name='%s' nodes='%d' live='%d' live_graph_walk='%d'",
4525                   phase_name(), _compile->unique(), _compile->live_nodes(), _compile->count_live_nodes_by_graph_walk());
4526   }
4527 
4528   if (VerifyIdealNodeCount) {
4529     _compile->print_missing_nodes();
4530   }
4531 #endif
4532 
4533   if (_log != nullptr) {
4534     _log->done("phase name='%s' nodes='%d' live='%d'", phase_name(), _compile->unique(), _compile->live_nodes());
4535   }
4536 }
4537 
4538 //----------------------------static_subtype_check-----------------------------
4539 // Shortcut important common cases when superklass is exact:
4540 // (0) superklass is java.lang.Object (can occur in reflective code)
4541 // (1) subklass is already limited to a subtype of superklass => always ok
4542 // (2) subklass does not overlap with superklass => always fail
4543 // (3) superklass has NO subtypes and we can check with a simple compare.
4544 Compile::SubTypeCheckResult Compile::static_subtype_check(const TypeKlassPtr* superk, const TypeKlassPtr* subk, bool skip) {
4545   if (skip) {
4546     return SSC_full_test;       // Let caller generate the general case.
4547   }
4548 
4549   if (subk->is_java_subtype_of(superk)) {
4550     return SSC_always_true; // (0) and (1)  this test cannot fail
4551   }
4552 
4553   if (!subk->maybe_java_subtype_of(superk)) {
4554     return SSC_always_false; // (2) true path dead; no dynamic test needed
4555   }
4556 
4557   const Type* superelem = superk;
4558   if (superk->isa_aryklassptr()) {
4559     int ignored;
4560     superelem = superk->is_aryklassptr()->base_element_type(ignored);
4561   }
4562 
4563   if (superelem->isa_instklassptr()) {
4564     ciInstanceKlass* ik = superelem->is_instklassptr()->instance_klass();
4565     if (!ik->has_subklass()) {
4566       if (!ik->is_final()) {
4567         // Add a dependency if there is a chance of a later subclass.
4568         dependencies()->assert_leaf_type(ik);
4569       }
4570       if (!superk->maybe_java_subtype_of(subk)) {
4571         return SSC_always_false;
4572       }
4573       return SSC_easy_test;     // (3) caller can do a simple ptr comparison
4574     }
4575   } else {
4576     // A primitive array type has no subtypes.
4577     return SSC_easy_test;       // (3) caller can do a simple ptr comparison
4578   }
4579 
4580   return SSC_full_test;
4581 }
4582 
4583 Node* Compile::conv_I2X_index(PhaseGVN* phase, Node* idx, const TypeInt* sizetype, Node* ctrl) {
4584 #ifdef _LP64
4585   // The scaled index operand to AddP must be a clean 64-bit value.
4586   // Java allows a 32-bit int to be incremented to a negative
4587   // value, which appears in a 64-bit register as a large
4588   // positive number.  Using that large positive number as an
4589   // operand in pointer arithmetic has bad consequences.
4590   // On the other hand, 32-bit overflow is rare, and the possibility
4591   // can often be excluded, if we annotate the ConvI2L node with
4592   // a type assertion that its value is known to be a small positive
4593   // number.  (The prior range check has ensured this.)
4594   // This assertion is used by ConvI2LNode::Ideal.
4595   int index_max = max_jint - 1;  // array size is max_jint, index is one less
4596   if (sizetype != nullptr && sizetype->_hi > 0) {
4597     index_max = sizetype->_hi - 1;
4598   }
4599   const TypeInt* iidxtype = TypeInt::make(0, index_max, Type::WidenMax);
4600   idx = constrained_convI2L(phase, idx, iidxtype, ctrl);
4601 #endif
4602   return idx;
4603 }
4604 
4605 // Convert integer value to a narrowed long type dependent on ctrl (for example, a range check)
4606 Node* Compile::constrained_convI2L(PhaseGVN* phase, Node* value, const TypeInt* itype, Node* ctrl, bool carry_dependency) {
4607   if (ctrl != nullptr) {
4608     // Express control dependency by a CastII node with a narrow type.
4609     // Make the CastII node dependent on the control input to prevent the narrowed ConvI2L
4610     // node from floating above the range check during loop optimizations. Otherwise, the
4611     // ConvI2L node may be eliminated independently of the range check, causing the data path
4612     // to become TOP while the control path is still there (although it's unreachable).
4613     value = new CastIINode(ctrl, value, itype, carry_dependency ? ConstraintCastNode::DependencyType::NonFloatingNarrowing : ConstraintCastNode::DependencyType::FloatingNarrowing, true /* range check dependency */);
4614     value = phase->transform(value);
4615   }
4616   const TypeLong* ltype = TypeLong::make(itype->_lo, itype->_hi, itype->_widen);
4617   return phase->transform(new ConvI2LNode(value, ltype));
4618 }
4619 
4620 void Compile::dump_print_inlining() {
4621   inline_printer()->print_on(tty);
4622 }
4623 
4624 void Compile::log_late_inline(CallGenerator* cg) {
4625   if (log() != nullptr) {
4626     log()->head("late_inline method='%d' inline_id='" JLONG_FORMAT "'", log()->identify(cg->method()),
4627                 cg->unique_id());
4628     JVMState* p = cg->call_node()->jvms();
4629     while (p != nullptr) {
4630       log()->elem("jvms bci='%d' method='%d'", p->bci(), log()->identify(p->method()));
4631       p = p->caller();
4632     }
4633     log()->tail("late_inline");
4634   }
4635 }
4636 
4637 void Compile::log_late_inline_failure(CallGenerator* cg, const char* msg) {
4638   log_late_inline(cg);
4639   if (log() != nullptr) {
4640     log()->inline_fail(msg);
4641   }
4642 }
4643 
4644 void Compile::log_inline_id(CallGenerator* cg) {
4645   if (log() != nullptr) {
4646     // The LogCompilation tool needs a unique way to identify late
4647     // inline call sites. This id must be unique for this call site in
4648     // this compilation. Try to have it unique across compilations as
4649     // well because it can be convenient when grepping through the log
4650     // file.
4651     // Distinguish OSR compilations from others in case CICountOSR is
4652     // on.
4653     jlong id = ((jlong)unique()) + (((jlong)compile_id()) << 33) + (CICountOSR && is_osr_compilation() ? ((jlong)1) << 32 : 0);
4654     cg->set_unique_id(id);
4655     log()->elem("inline_id id='" JLONG_FORMAT "'", id);
4656   }
4657 }
4658 
4659 void Compile::log_inline_failure(const char* msg) {
4660   if (C->log() != nullptr) {
4661     C->log()->inline_fail(msg);
4662   }
4663 }
4664 
4665 
4666 // Dump inlining replay data to the stream.
4667 // Don't change thread state and acquire any locks.
4668 void Compile::dump_inline_data(outputStream* out) {
4669   InlineTree* inl_tree = ilt();
4670   if (inl_tree != nullptr) {
4671     out->print(" inline %d", inl_tree->count());
4672     inl_tree->dump_replay_data(out);
4673   }
4674 }
4675 
4676 void Compile::dump_inline_data_reduced(outputStream* out) {
4677   assert(ReplayReduce, "");
4678 
4679   InlineTree* inl_tree = ilt();
4680   if (inl_tree == nullptr) {
4681     return;
4682   }
4683   // Enable iterative replay file reduction
4684   // Output "compile" lines for depth 1 subtrees,
4685   // simulating that those trees were compiled
4686   // instead of inlined.
4687   for (int i = 0; i < inl_tree->subtrees().length(); ++i) {
4688     InlineTree* sub = inl_tree->subtrees().at(i);
4689     if (sub->inline_level() != 1) {
4690       continue;
4691     }
4692 
4693     ciMethod* method = sub->method();
4694     int entry_bci = -1;
4695     int comp_level = env()->task()->comp_level();
4696     out->print("compile ");
4697     method->dump_name_as_ascii(out);
4698     out->print(" %d %d", entry_bci, comp_level);
4699     out->print(" inline %d", sub->count());
4700     sub->dump_replay_data(out, -1);
4701     out->cr();
4702   }
4703 }
4704 
4705 int Compile::cmp_expensive_nodes(Node* n1, Node* n2) {
4706   if (n1->Opcode() < n2->Opcode())      return -1;
4707   else if (n1->Opcode() > n2->Opcode()) return 1;
4708 
4709   assert(n1->req() == n2->req(), "can't compare %s nodes: n1->req() = %d, n2->req() = %d", NodeClassNames[n1->Opcode()], n1->req(), n2->req());
4710   for (uint i = 1; i < n1->req(); i++) {
4711     if (n1->in(i) < n2->in(i))      return -1;
4712     else if (n1->in(i) > n2->in(i)) return 1;
4713   }
4714 
4715   return 0;
4716 }
4717 
4718 int Compile::cmp_expensive_nodes(Node** n1p, Node** n2p) {
4719   Node* n1 = *n1p;
4720   Node* n2 = *n2p;
4721 
4722   return cmp_expensive_nodes(n1, n2);
4723 }
4724 
4725 void Compile::sort_expensive_nodes() {
4726   if (!expensive_nodes_sorted()) {
4727     _expensive_nodes.sort(cmp_expensive_nodes);
4728   }
4729 }
4730 
4731 bool Compile::expensive_nodes_sorted() const {
4732   for (int i = 1; i < _expensive_nodes.length(); i++) {
4733     if (cmp_expensive_nodes(_expensive_nodes.adr_at(i), _expensive_nodes.adr_at(i-1)) < 0) {
4734       return false;
4735     }
4736   }
4737   return true;
4738 }
4739 
4740 bool Compile::should_optimize_expensive_nodes(PhaseIterGVN &igvn) {
4741   if (_expensive_nodes.length() == 0) {
4742     return false;
4743   }
4744 
4745   assert(OptimizeExpensiveOps, "optimization off?");
4746 
4747   // Take this opportunity to remove dead nodes from the list
4748   int j = 0;
4749   for (int i = 0; i < _expensive_nodes.length(); i++) {
4750     Node* n = _expensive_nodes.at(i);
4751     if (!n->is_unreachable(igvn)) {
4752       assert(n->is_expensive(), "should be expensive");
4753       _expensive_nodes.at_put(j, n);
4754       j++;
4755     }
4756   }
4757   _expensive_nodes.trunc_to(j);
4758 
4759   // Then sort the list so that similar nodes are next to each other
4760   // and check for at least two nodes of identical kind with same data
4761   // inputs.
4762   sort_expensive_nodes();
4763 
4764   for (int i = 0; i < _expensive_nodes.length()-1; i++) {
4765     if (cmp_expensive_nodes(_expensive_nodes.adr_at(i), _expensive_nodes.adr_at(i+1)) == 0) {
4766       return true;
4767     }
4768   }
4769 
4770   return false;
4771 }
4772 
4773 void Compile::cleanup_expensive_nodes(PhaseIterGVN &igvn) {
4774   if (_expensive_nodes.length() == 0) {
4775     return;
4776   }
4777 
4778   assert(OptimizeExpensiveOps, "optimization off?");
4779 
4780   // Sort to bring similar nodes next to each other and clear the
4781   // control input of nodes for which there's only a single copy.
4782   sort_expensive_nodes();
4783 
4784   int j = 0;
4785   int identical = 0;
4786   int i = 0;
4787   bool modified = false;
4788   for (; i < _expensive_nodes.length()-1; i++) {
4789     assert(j <= i, "can't write beyond current index");
4790     if (_expensive_nodes.at(i)->Opcode() == _expensive_nodes.at(i+1)->Opcode()) {
4791       identical++;
4792       _expensive_nodes.at_put(j++, _expensive_nodes.at(i));
4793       continue;
4794     }
4795     if (identical > 0) {
4796       _expensive_nodes.at_put(j++, _expensive_nodes.at(i));
4797       identical = 0;
4798     } else {
4799       Node* n = _expensive_nodes.at(i);
4800       igvn.replace_input_of(n, 0, nullptr);
4801       igvn.hash_insert(n);
4802       modified = true;
4803     }
4804   }
4805   if (identical > 0) {
4806     _expensive_nodes.at_put(j++, _expensive_nodes.at(i));
4807   } else if (_expensive_nodes.length() >= 1) {
4808     Node* n = _expensive_nodes.at(i);
4809     igvn.replace_input_of(n, 0, nullptr);
4810     igvn.hash_insert(n);
4811     modified = true;
4812   }
4813   _expensive_nodes.trunc_to(j);
4814   if (modified) {
4815     igvn.optimize();
4816   }
4817 }
4818 
4819 void Compile::add_expensive_node(Node * n) {
4820   assert(!_expensive_nodes.contains(n), "duplicate entry in expensive list");
4821   assert(n->is_expensive(), "expensive nodes with non-null control here only");
4822   assert(!n->is_CFG() && !n->is_Mem(), "no cfg or memory nodes here");
4823   if (OptimizeExpensiveOps) {
4824     _expensive_nodes.append(n);
4825   } else {
4826     // Clear control input and let IGVN optimize expensive nodes if
4827     // OptimizeExpensiveOps is off.
4828     n->set_req(0, nullptr);
4829   }
4830 }
4831 
4832 /**
4833  * Track coarsened Lock and Unlock nodes.
4834  */
4835 
4836 class Lock_List : public Node_List {
4837   uint _origin_cnt;
4838 public:
4839   Lock_List(Arena *a, uint cnt) : Node_List(a), _origin_cnt(cnt) {}
4840   uint origin_cnt() const { return _origin_cnt; }
4841 };
4842 
4843 void Compile::add_coarsened_locks(GrowableArray<AbstractLockNode*>& locks) {
4844   int length = locks.length();
4845   if (length > 0) {
4846     // Have to keep this list until locks elimination during Macro nodes elimination.
4847     Lock_List* locks_list = new (comp_arena()) Lock_List(comp_arena(), length);
4848     AbstractLockNode* alock = locks.at(0);
4849     BoxLockNode* box = alock->box_node()->as_BoxLock();
4850     for (int i = 0; i < length; i++) {
4851       AbstractLockNode* lock = locks.at(i);
4852       assert(lock->is_coarsened(), "expecting only coarsened AbstractLock nodes, but got '%s'[%d] node", lock->Name(), lock->_idx);
4853       locks_list->push(lock);
4854       BoxLockNode* this_box = lock->box_node()->as_BoxLock();
4855       if (this_box != box) {
4856         // Locking regions (BoxLock) could be Unbalanced here:
4857         //  - its coarsened locks were eliminated in earlier
4858         //    macro nodes elimination followed by loop unroll
4859         //  - it is OSR locking region (no Lock node)
4860         // Preserve Unbalanced status in such cases.
4861         if (!this_box->is_unbalanced()) {
4862           this_box->set_coarsened();
4863         }
4864         if (!box->is_unbalanced()) {
4865           box->set_coarsened();
4866         }
4867       }
4868     }
4869     _coarsened_locks.append(locks_list);
4870   }
4871 }
4872 
4873 void Compile::remove_useless_coarsened_locks(Unique_Node_List& useful) {
4874   int count = coarsened_count();
4875   for (int i = 0; i < count; i++) {
4876     Node_List* locks_list = _coarsened_locks.at(i);
4877     for (uint j = 0; j < locks_list->size(); j++) {
4878       Node* lock = locks_list->at(j);
4879       assert(lock->is_AbstractLock(), "sanity");
4880       if (!useful.member(lock)) {
4881         locks_list->yank(lock);
4882       }
4883     }
4884   }
4885 }
4886 
4887 void Compile::remove_coarsened_lock(Node* n) {
4888   if (n->is_AbstractLock()) {
4889     int count = coarsened_count();
4890     for (int i = 0; i < count; i++) {
4891       Node_List* locks_list = _coarsened_locks.at(i);
4892       locks_list->yank(n);
4893     }
4894   }
4895 }
4896 
4897 bool Compile::coarsened_locks_consistent() {
4898   int count = coarsened_count();
4899   for (int i = 0; i < count; i++) {
4900     bool unbalanced = false;
4901     bool modified = false; // track locks kind modifications
4902     Lock_List* locks_list = (Lock_List*)_coarsened_locks.at(i);
4903     uint size = locks_list->size();
4904     if (size == 0) {
4905       unbalanced = false; // All locks were eliminated - good
4906     } else if (size != locks_list->origin_cnt()) {
4907       unbalanced = true; // Some locks were removed from list
4908     } else {
4909       for (uint j = 0; j < size; j++) {
4910         Node* lock = locks_list->at(j);
4911         // All nodes in group should have the same state (modified or not)
4912         if (!lock->as_AbstractLock()->is_coarsened()) {
4913           if (j == 0) {
4914             // first on list was modified, the rest should be too for consistency
4915             modified = true;
4916           } else if (!modified) {
4917             // this lock was modified but previous locks on the list were not
4918             unbalanced = true;
4919             break;
4920           }
4921         } else if (modified) {
4922           // previous locks on list were modified but not this lock
4923           unbalanced = true;
4924           break;
4925         }
4926       }
4927     }
4928     if (unbalanced) {
4929       // unbalanced monitor enter/exit - only some [un]lock nodes were removed or modified
4930 #ifdef ASSERT
4931       if (PrintEliminateLocks) {
4932         tty->print_cr("=== unbalanced coarsened locks ===");
4933         for (uint l = 0; l < size; l++) {
4934           locks_list->at(l)->dump();
4935         }
4936       }
4937 #endif
4938       record_failure(C2Compiler::retry_no_locks_coarsening());
4939       return false;
4940     }
4941   }
4942   return true;
4943 }
4944 
4945 // Mark locking regions (identified by BoxLockNode) as unbalanced if
4946 // locks coarsening optimization removed Lock/Unlock nodes from them.
4947 // Such regions become unbalanced because coarsening only removes part
4948 // of Lock/Unlock nodes in region. As result we can't execute other
4949 // locks elimination optimizations which assume all code paths have
4950 // corresponding pair of Lock/Unlock nodes - they are balanced.
4951 void Compile::mark_unbalanced_boxes() const {
4952   int count = coarsened_count();
4953   for (int i = 0; i < count; i++) {
4954     Node_List* locks_list = _coarsened_locks.at(i);
4955     uint size = locks_list->size();
4956     if (size > 0) {
4957       AbstractLockNode* alock = locks_list->at(0)->as_AbstractLock();
4958       BoxLockNode* box = alock->box_node()->as_BoxLock();
4959       if (alock->is_coarsened()) {
4960         // coarsened_locks_consistent(), which is called before this method, verifies
4961         // that the rest of Lock/Unlock nodes on locks_list are also coarsened.
4962         assert(!box->is_eliminated(), "regions with coarsened locks should not be marked as eliminated");
4963         for (uint j = 1; j < size; j++) {
4964           assert(locks_list->at(j)->as_AbstractLock()->is_coarsened(), "only coarsened locks are expected here");
4965           BoxLockNode* this_box = locks_list->at(j)->as_AbstractLock()->box_node()->as_BoxLock();
4966           if (box != this_box) {
4967             assert(!this_box->is_eliminated(), "regions with coarsened locks should not be marked as eliminated");
4968             box->set_unbalanced();
4969             this_box->set_unbalanced();
4970           }
4971         }
4972       }
4973     }
4974   }
4975 }
4976 
4977 /**
4978  * Remove the speculative part of types and clean up the graph
4979  */
4980 void Compile::remove_speculative_types(PhaseIterGVN &igvn) {
4981   if (UseTypeSpeculation) {
4982     Unique_Node_List worklist;
4983     worklist.push(root());
4984     int modified = 0;
4985     // Go over all type nodes that carry a speculative type, drop the
4986     // speculative part of the type and enqueue the node for an igvn
4987     // which may optimize it out.
4988     for (uint next = 0; next < worklist.size(); ++next) {
4989       Node *n  = worklist.at(next);
4990       if (n->is_Type()) {
4991         TypeNode* tn = n->as_Type();
4992         const Type* t = tn->type();
4993         const Type* t_no_spec = t->remove_speculative();
4994         if (t_no_spec != t) {
4995           bool in_hash = igvn.hash_delete(n);
4996           assert(in_hash || n->hash() == Node::NO_HASH, "node should be in igvn hash table");
4997           tn->set_type(t_no_spec);
4998           igvn.hash_insert(n);
4999           igvn._worklist.push(n); // give it a chance to go away
5000           modified++;
5001         }
5002       }
5003       // Iterate over outs - endless loops is unreachable from below
5004       for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
5005         Node *m = n->fast_out(i);
5006         if (not_a_node(m)) {
5007           continue;
5008         }
5009         worklist.push(m);
5010       }
5011     }
5012     // Drop the speculative part of all types in the igvn's type table
5013     igvn.remove_speculative_types();
5014     if (modified > 0) {
5015       igvn.optimize();
5016       if (failing())  return;
5017     }
5018 #ifdef ASSERT
5019     // Verify that after the IGVN is over no speculative type has resurfaced
5020     worklist.clear();
5021     worklist.push(root());
5022     for (uint next = 0; next < worklist.size(); ++next) {
5023       Node *n  = worklist.at(next);
5024       const Type* t = igvn.type_or_null(n);
5025       assert((t == nullptr) || (t == t->remove_speculative()), "no more speculative types");
5026       if (n->is_Type()) {
5027         t = n->as_Type()->type();
5028         assert(t == t->remove_speculative(), "no more speculative types");
5029       }
5030       // Iterate over outs - endless loops is unreachable from below
5031       for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
5032         Node *m = n->fast_out(i);
5033         if (not_a_node(m)) {
5034           continue;
5035         }
5036         worklist.push(m);
5037       }
5038     }
5039     igvn.check_no_speculative_types();
5040 #endif
5041   }
5042 }
5043 
5044 // Auxiliary methods to support randomized stressing/fuzzing.
5045 
5046 void Compile::initialize_stress_seed(const DirectiveSet* directive) {
5047   if (FLAG_IS_DEFAULT(StressSeed) || (FLAG_IS_ERGO(StressSeed) && directive->RepeatCompilationOption)) {
5048     _stress_seed = static_cast<uint>(Ticks::now().nanoseconds());
5049     FLAG_SET_ERGO(StressSeed, _stress_seed);
5050   } else {
5051     _stress_seed = StressSeed;
5052   }
5053   if (_log != nullptr) {
5054     _log->elem("stress_test seed='%u'", _stress_seed);
5055   }
5056 }
5057 
5058 int Compile::random() {
5059   _stress_seed = os::next_random(_stress_seed);
5060   return static_cast<int>(_stress_seed);
5061 }
5062 
5063 // This method can be called the arbitrary number of times, with current count
5064 // as the argument. The logic allows selecting a single candidate from the
5065 // running list of candidates as follows:
5066 //    int count = 0;
5067 //    Cand* selected = null;
5068 //    while(cand = cand->next()) {
5069 //      if (randomized_select(++count)) {
5070 //        selected = cand;
5071 //      }
5072 //    }
5073 //
5074 // Including count equalizes the chances any candidate is "selected".
5075 // This is useful when we don't have the complete list of candidates to choose
5076 // from uniformly. In this case, we need to adjust the randomicity of the
5077 // selection, or else we will end up biasing the selection towards the latter
5078 // candidates.
5079 //
5080 // Quick back-envelope calculation shows that for the list of n candidates
5081 // the equal probability for the candidate to persist as "best" can be
5082 // achieved by replacing it with "next" k-th candidate with the probability
5083 // of 1/k. It can be easily shown that by the end of the run, the
5084 // probability for any candidate is converged to 1/n, thus giving the
5085 // uniform distribution among all the candidates.
5086 //
5087 // We don't care about the domain size as long as (RANDOMIZED_DOMAIN / count) is large.
5088 #define RANDOMIZED_DOMAIN_POW 29
5089 #define RANDOMIZED_DOMAIN (1 << RANDOMIZED_DOMAIN_POW)
5090 #define RANDOMIZED_DOMAIN_MASK ((1 << (RANDOMIZED_DOMAIN_POW + 1)) - 1)
5091 bool Compile::randomized_select(int count) {
5092   assert(count > 0, "only positive");
5093   return (random() & RANDOMIZED_DOMAIN_MASK) < (RANDOMIZED_DOMAIN / count);
5094 }
5095 
5096 #ifdef ASSERT
5097 // Failures are geometrically distributed with probability 1/StressBailoutMean.
5098 bool Compile::fail_randomly() {
5099   if ((random() % StressBailoutMean) != 0) {
5100     return false;
5101   }
5102   record_failure("StressBailout");
5103   return true;
5104 }
5105 
5106 bool Compile::failure_is_artificial() {
5107   return C->failure_reason_is("StressBailout");
5108 }
5109 #endif
5110 
5111 CloneMap&     Compile::clone_map()                 { return _clone_map; }
5112 void          Compile::set_clone_map(Dict* d)      { _clone_map._dict = d; }
5113 
5114 void NodeCloneInfo::dump_on(outputStream* st) const {
5115   st->print(" {%d:%d} ", idx(), gen());
5116 }
5117 
5118 void CloneMap::clone(Node* old, Node* nnn, int gen) {
5119   uint64_t val = value(old->_idx);
5120   NodeCloneInfo cio(val);
5121   assert(val != 0, "old node should be in the map");
5122   NodeCloneInfo cin(cio.idx(), gen + cio.gen());
5123   insert(nnn->_idx, cin.get());
5124 #ifndef PRODUCT
5125   if (is_debug()) {
5126     tty->print_cr("CloneMap::clone inserted node %d info {%d:%d} into CloneMap", nnn->_idx, cin.idx(), cin.gen());
5127   }
5128 #endif
5129 }
5130 
5131 void CloneMap::verify_insert_and_clone(Node* old, Node* nnn, int gen) {
5132   NodeCloneInfo cio(value(old->_idx));
5133   if (cio.get() == 0) {
5134     cio.set(old->_idx, 0);
5135     insert(old->_idx, cio.get());
5136 #ifndef PRODUCT
5137     if (is_debug()) {
5138       tty->print_cr("CloneMap::verify_insert_and_clone inserted node %d info {%d:%d} into CloneMap", old->_idx, cio.idx(), cio.gen());
5139     }
5140 #endif
5141   }
5142   clone(old, nnn, gen);
5143 }
5144 
5145 int CloneMap::max_gen() const {
5146   int g = 0;
5147   DictI di(_dict);
5148   for(; di.test(); ++di) {
5149     int t = gen(di._key);
5150     if (g < t) {
5151       g = t;
5152 #ifndef PRODUCT
5153       if (is_debug()) {
5154         tty->print_cr("CloneMap::max_gen() update max=%d from %d", g, _2_node_idx_t(di._key));
5155       }
5156 #endif
5157     }
5158   }
5159   return g;
5160 }
5161 
5162 void CloneMap::dump(node_idx_t key, outputStream* st) const {
5163   uint64_t val = value(key);
5164   if (val != 0) {
5165     NodeCloneInfo ni(val);
5166     ni.dump_on(st);
5167   }
5168 }
5169 
5170 void Compile::shuffle_macro_nodes() {
5171   shuffle_array(*C, _macro_nodes);
5172 }
5173 
5174 // Move Allocate nodes to the start of the list
5175 void Compile::sort_macro_nodes() {
5176   int count = macro_count();
5177   int allocates = 0;
5178   for (int i = 0; i < count; i++) {
5179     Node* n = macro_node(i);
5180     if (n->is_Allocate()) {
5181       if (i != allocates) {
5182         Node* tmp = macro_node(allocates);
5183         _macro_nodes.at_put(allocates, n);
5184         _macro_nodes.at_put(i, tmp);
5185       }
5186       allocates++;
5187     }
5188   }
5189 }
5190 
5191 void Compile::print_method(CompilerPhaseType compile_phase, int level, Node* n) {
5192   if (failing_internal()) { return; } // failing_internal to not stress bailouts from printing code.
5193   EventCompilerPhase event(UNTIMED);
5194   if (event.should_commit()) {
5195     CompilerEvent::PhaseEvent::post(event, C->_latest_stage_start_counter, compile_phase, C->_compile_id, level);
5196   }
5197 #ifndef PRODUCT
5198   ResourceMark rm;
5199   stringStream ss;
5200   ss.print_raw(CompilerPhaseTypeHelper::to_description(compile_phase));
5201   int iter = ++_igv_phase_iter[compile_phase];
5202   if (iter > 1) {
5203     ss.print(" %d", iter);
5204   }
5205   if (n != nullptr) {
5206     ss.print(": %d %s", n->_idx, NodeClassNames[n->Opcode()]);
5207     if (n->is_Call()) {
5208       CallNode* call = n->as_Call();
5209       if (call->_name != nullptr) {
5210         // E.g. uncommon traps etc.
5211         ss.print(" - %s", call->_name);
5212       } else if (call->is_CallJava()) {
5213         CallJavaNode* call_java = call->as_CallJava();
5214         if (call_java->method() != nullptr) {
5215           ss.print(" -");
5216           call_java->method()->print_short_name(&ss);
5217         }
5218       }
5219     }
5220   }
5221 
5222   const char* name = ss.as_string();
5223   if (should_print_igv(level)) {
5224     _igv_printer->print_graph(name);
5225   }
5226   if (should_print_phase(level)) {
5227     print_phase(name);
5228   }
5229   if (should_print_ideal_phase(compile_phase)) {
5230     print_ideal_ir(CompilerPhaseTypeHelper::to_name(compile_phase));
5231   }
5232 #endif
5233   C->_latest_stage_start_counter.stamp();
5234 }
5235 
5236 // Only used from CompileWrapper
5237 void Compile::begin_method() {
5238 #ifndef PRODUCT
5239   if (_method != nullptr && should_print_igv(1)) {
5240     _igv_printer->begin_method();
5241   }
5242 #endif
5243   C->_latest_stage_start_counter.stamp();
5244 }
5245 
5246 // Only used from CompileWrapper
5247 void Compile::end_method() {
5248   EventCompilerPhase event(UNTIMED);
5249   if (event.should_commit()) {
5250     CompilerEvent::PhaseEvent::post(event, C->_latest_stage_start_counter, PHASE_END, C->_compile_id, 1);
5251   }
5252 
5253 #ifndef PRODUCT
5254   if (_method != nullptr && should_print_igv(1)) {
5255     _igv_printer->end_method();
5256   }
5257 #endif
5258 }
5259 
5260 #ifndef PRODUCT
5261 bool Compile::should_print_phase(const int level) const {
5262   return PrintPhaseLevel >= 0 && directive()->PhasePrintLevelOption >= level &&
5263          _method != nullptr; // Do not print phases for stubs.
5264 }
5265 
5266 bool Compile::should_print_ideal_phase(CompilerPhaseType cpt) const {
5267   return _directive->should_print_ideal_phase(cpt);
5268 }
5269 
5270 void Compile::init_igv() {
5271   if (_igv_printer == nullptr) {
5272     _igv_printer = IdealGraphPrinter::printer();
5273     _igv_printer->set_compile(this);
5274   }
5275 }
5276 
5277 bool Compile::should_print_igv(const int level) {
5278   PRODUCT_RETURN_(return false;);
5279 
5280   if (PrintIdealGraphLevel < 0) { // disabled by the user
5281     return false;
5282   }
5283 
5284   bool need = directive()->IGVPrintLevelOption >= level;
5285   if (need) {
5286     Compile::init_igv();
5287   }
5288   return need;
5289 }
5290 
5291 IdealGraphPrinter* Compile::_debug_file_printer = nullptr;
5292 IdealGraphPrinter* Compile::_debug_network_printer = nullptr;
5293 
5294 // Called from debugger. Prints method to the default file with the default phase name.
5295 // This works regardless of any Ideal Graph Visualizer flags set or not.
5296 // Use in debugger (gdb/rr): p igv_print($sp, $fp, $pc).
5297 void igv_print(void* sp, void* fp, void* pc) {
5298   frame fr(sp, fp, pc);
5299   Compile::current()->igv_print_method_to_file(nullptr, false, &fr);
5300 }
5301 
5302 // Same as igv_print() above but with a specified phase name.
5303 void igv_print(const char* phase_name, void* sp, void* fp, void* pc) {
5304   frame fr(sp, fp, pc);
5305   Compile::current()->igv_print_method_to_file(phase_name, false, &fr);
5306 }
5307 
5308 // Called from debugger. Prints method with the default phase name to the default network or the one specified with
5309 // the network flags for the Ideal Graph Visualizer, or to the default file depending on the 'network' argument.
5310 // This works regardless of any Ideal Graph Visualizer flags set or not.
5311 // Use in debugger (gdb/rr): p igv_print(true, $sp, $fp, $pc).
5312 void igv_print(bool network, void* sp, void* fp, void* pc) {
5313   frame fr(sp, fp, pc);
5314   if (network) {
5315     Compile::current()->igv_print_method_to_network(nullptr, &fr);
5316   } else {
5317     Compile::current()->igv_print_method_to_file(nullptr, false, &fr);
5318   }
5319 }
5320 
5321 // Same as igv_print(bool network, ...) above but with a specified phase name.
5322 // Use in debugger (gdb/rr): p igv_print(true, "MyPhase", $sp, $fp, $pc).
5323 void igv_print(bool network, const char* phase_name, void* sp, void* fp, void* pc) {
5324   frame fr(sp, fp, pc);
5325   if (network) {
5326     Compile::current()->igv_print_method_to_network(phase_name, &fr);
5327   } else {
5328     Compile::current()->igv_print_method_to_file(phase_name, false, &fr);
5329   }
5330 }
5331 
5332 // Called from debugger. Normal write to the default _printer. Only works if Ideal Graph Visualizer printing flags are set.
5333 void igv_print_default() {
5334   Compile::current()->print_method(PHASE_DEBUG, 0);
5335 }
5336 
5337 // Called from debugger, especially when replaying a trace in which the program state cannot be altered like with rr replay.
5338 // A method is appended to an existing default file with the default phase name. This means that igv_append() must follow
5339 // an earlier igv_print(*) call which sets up the file. This works regardless of any Ideal Graph Visualizer flags set or not.
5340 // Use in debugger (gdb/rr): p igv_append($sp, $fp, $pc).
5341 void igv_append(void* sp, void* fp, void* pc) {
5342   frame fr(sp, fp, pc);
5343   Compile::current()->igv_print_method_to_file(nullptr, true, &fr);
5344 }
5345 
5346 // Same as igv_append(...) above but with a specified phase name.
5347 // Use in debugger (gdb/rr): p igv_append("MyPhase", $sp, $fp, $pc).
5348 void igv_append(const char* phase_name, void* sp, void* fp, void* pc) {
5349   frame fr(sp, fp, pc);
5350   Compile::current()->igv_print_method_to_file(phase_name, true, &fr);
5351 }
5352 
5353 void Compile::igv_print_method_to_file(const char* phase_name, bool append, const frame* fr) {
5354   const char* file_name = "custom_debug.xml";
5355   if (_debug_file_printer == nullptr) {
5356     _debug_file_printer = new IdealGraphPrinter(C, file_name, append);
5357   } else {
5358     _debug_file_printer->update_compiled_method(C->method());
5359   }
5360   tty->print_cr("Method %s to %s", append ? "appended" : "printed", file_name);
5361   _debug_file_printer->print_graph(phase_name, fr);
5362 }
5363 
5364 void Compile::igv_print_method_to_network(const char* phase_name, const frame* fr) {
5365   ResourceMark rm;
5366   GrowableArray<const Node*> empty_list;
5367   igv_print_graph_to_network(phase_name, empty_list, fr);
5368 }
5369 
5370 void Compile::igv_print_graph_to_network(const char* name, GrowableArray<const Node*>& visible_nodes, const frame* fr) {
5371   if (_debug_network_printer == nullptr) {
5372     _debug_network_printer = new IdealGraphPrinter(C);
5373   } else {
5374     _debug_network_printer->update_compiled_method(C->method());
5375   }
5376   tty->print_cr("Method printed over network stream to IGV");
5377   _debug_network_printer->print(name, C->root(), visible_nodes, fr);
5378 }
5379 #endif // !PRODUCT
5380 
5381 Node* Compile::narrow_value(BasicType bt, Node* value, const Type* type, PhaseGVN* phase, bool transform_res) {
5382   precond(type != nullptr);
5383 
5384   if (phase->type(value)->higher_equal(type)) {
5385     return value;
5386   }
5387   Node* result = nullptr;
5388   if (bt == T_BYTE) {
5389     result = phase->transform(new LShiftINode(value, phase->intcon(24)));
5390     result = new RShiftINode(result, phase->intcon(24));
5391   } else if (bt == T_BOOLEAN) {
5392     assert(type == TypeInt::BOOL || type == TypeInt::UBYTE, "unexpected boolean type: %s", Type::str(type));
5393     Node* mask = phase->intcon(type == TypeInt::BOOL ? 1 : 0xFF);
5394     result = new AndINode(value, mask);
5395   } else if (bt == T_CHAR) {
5396     result = new AndINode(value,phase->intcon(0xFFFF));
5397   } else {
5398     assert(bt == T_SHORT, "unexpected narrow type");
5399     result = phase->transform(new LShiftINode(value, phase->intcon(16)));
5400     result = new RShiftINode(result, phase->intcon(16));
5401   }
5402   if (transform_res) {
5403     result = phase->transform(result);
5404   }
5405   return result;
5406 }
5407 
5408 void Compile::record_method_not_compilable_oom() {
5409   record_method_not_compilable(CompilationMemoryStatistic::failure_reason_memlimit());
5410 }
5411 
5412 #ifndef PRODUCT
5413 // Collects all the control inputs from nodes on the worklist and from their data dependencies
5414 static void find_candidate_control_inputs(Unique_Node_List& worklist, Unique_Node_List& candidates) {
5415   // Follow non-control edges until we reach CFG nodes
5416   for (uint i = 0; i < worklist.size(); i++) {
5417     const Node* n = worklist.at(i);
5418     for (uint j = 0; j < n->req(); j++) {
5419       Node* in = n->in(j);
5420       if (in == nullptr || in->is_Root()) {
5421         continue;
5422       }
5423       if (in->is_CFG()) {
5424         if (in->is_Call()) {
5425           // The return value of a call is only available if the call did not result in an exception
5426           Node* control_proj_use = in->as_Call()->proj_out(TypeFunc::Control)->unique_out();
5427           if (control_proj_use->is_Catch()) {
5428             Node* fall_through = control_proj_use->as_Catch()->proj_out(CatchProjNode::fall_through_index);
5429             candidates.push(fall_through);
5430             continue;
5431           }
5432         }
5433 
5434         if (in->is_Multi()) {
5435           // We got here by following data inputs so we should only have one control use
5436           // (no IfNode, etc)
5437           assert(!n->is_MultiBranch(), "unexpected node type: %s", n->Name());
5438           candidates.push(in->as_Multi()->proj_out(TypeFunc::Control));
5439         } else {
5440           candidates.push(in);
5441         }
5442       } else {
5443         worklist.push(in);
5444       }
5445     }
5446   }
5447 }
5448 
5449 // Returns the candidate node that is a descendant to all the other candidates
5450 static Node* pick_control(Unique_Node_List& candidates) {
5451   Unique_Node_List worklist;
5452   worklist.copy(candidates);
5453 
5454   // Traverse backwards through the CFG
5455   for (uint i = 0; i < worklist.size(); i++) {
5456     const Node* n = worklist.at(i);
5457     if (n->is_Root()) {
5458       continue;
5459     }
5460     for (uint j = 0; j < n->req(); j++) {
5461       // Skip backedge of loops to avoid cycles
5462       if (n->is_Loop() && j == LoopNode::LoopBackControl) {
5463         continue;
5464       }
5465 
5466       Node* pred = n->in(j);
5467       if (pred != nullptr && pred != n && pred->is_CFG()) {
5468         worklist.push(pred);
5469         // if pred is an ancestor of n, then pred is an ancestor to at least one candidate
5470         candidates.remove(pred);
5471       }
5472     }
5473   }
5474 
5475   assert(candidates.size() == 1, "unexpected control flow");
5476   return candidates.at(0);
5477 }
5478 
5479 // Initialize a parameter input for a debug print call, using a placeholder for jlong and jdouble
5480 static void debug_print_init_parm(Node* call, Node* parm, Node* half, int* pos) {
5481   call->init_req((*pos)++, parm);
5482   const BasicType bt = parm->bottom_type()->basic_type();
5483   if (bt == T_LONG || bt == T_DOUBLE) {
5484     call->init_req((*pos)++, half);
5485   }
5486 }
5487 
5488 Node* Compile::make_debug_print_call(const char* str, address call_addr, PhaseGVN* gvn,
5489                               Node* parm0, Node* parm1,
5490                               Node* parm2, Node* parm3,
5491                               Node* parm4, Node* parm5,
5492                               Node* parm6) const {
5493   Node* str_node = gvn->transform(new ConPNode(TypeRawPtr::make(((address) str))));
5494   const TypeFunc* type = OptoRuntime::debug_print_Type(parm0, parm1, parm2, parm3, parm4, parm5, parm6);
5495   Node* call = new CallLeafNode(type, call_addr, "debug_print", TypeRawPtr::BOTTOM);
5496 
5497   // find the most suitable control input
5498   Unique_Node_List worklist, candidates;
5499   if (parm0 != nullptr) { worklist.push(parm0);
5500   if (parm1 != nullptr) { worklist.push(parm1);
5501   if (parm2 != nullptr) { worklist.push(parm2);
5502   if (parm3 != nullptr) { worklist.push(parm3);
5503   if (parm4 != nullptr) { worklist.push(parm4);
5504   if (parm5 != nullptr) { worklist.push(parm5);
5505   if (parm6 != nullptr) { worklist.push(parm6);
5506   /* close each nested if ===> */  } } } } } } }
5507   find_candidate_control_inputs(worklist, candidates);
5508   Node* control = nullptr;
5509   if (candidates.size() == 0) {
5510     control = C->start()->proj_out(TypeFunc::Control);
5511   } else {
5512     control = pick_control(candidates);
5513   }
5514 
5515   // find all the previous users of the control we picked
5516   GrowableArray<Node*> users_of_control;
5517   for (DUIterator_Fast kmax, i = control->fast_outs(kmax); i < kmax; i++) {
5518     Node* use = control->fast_out(i);
5519     if (use->is_CFG() && use != control) {
5520       users_of_control.push(use);
5521     }
5522   }
5523 
5524   // we do not actually care about IO and memory as it uses neither
5525   call->init_req(TypeFunc::Control,   control);
5526   call->init_req(TypeFunc::I_O,       top());
5527   call->init_req(TypeFunc::Memory,    top());
5528   call->init_req(TypeFunc::FramePtr,  C->start()->proj_out(TypeFunc::FramePtr));
5529   call->init_req(TypeFunc::ReturnAdr, top());
5530 
5531   int pos = TypeFunc::Parms;
5532   call->init_req(pos++, str_node);
5533   if (parm0 != nullptr) { debug_print_init_parm(call, parm0, top(), &pos);
5534   if (parm1 != nullptr) { debug_print_init_parm(call, parm1, top(), &pos);
5535   if (parm2 != nullptr) { debug_print_init_parm(call, parm2, top(), &pos);
5536   if (parm3 != nullptr) { debug_print_init_parm(call, parm3, top(), &pos);
5537   if (parm4 != nullptr) { debug_print_init_parm(call, parm4, top(), &pos);
5538   if (parm5 != nullptr) { debug_print_init_parm(call, parm5, top(), &pos);
5539   if (parm6 != nullptr) { debug_print_init_parm(call, parm6, top(), &pos);
5540   /* close each nested if ===> */  } } } } } } }
5541   assert(call->in(call->req()-1) != nullptr, "must initialize all parms");
5542 
5543   call = gvn->transform(call);
5544   Node* call_control_proj = gvn->transform(new ProjNode(call, TypeFunc::Control));
5545 
5546   // rewire previous users to have the new call as control instead
5547   PhaseIterGVN* igvn = gvn->is_IterGVN();
5548   for (int i = 0; i < users_of_control.length(); i++) {
5549     Node* use = users_of_control.at(i);
5550     for (uint j = 0; j < use->req(); j++) {
5551       if (use->in(j) == control) {
5552         if (igvn != nullptr) {
5553           igvn->replace_input_of(use, j, call_control_proj);
5554         } else {
5555           gvn->hash_delete(use);
5556           use->set_req(j, call_control_proj);
5557           gvn->hash_insert(use);
5558         }
5559       }
5560     }
5561   }
5562 
5563   return call;
5564 }
5565 #endif // !PRODUCT