1 /*
   2  * Copyright (c) 1997, 2026, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "asm/macroAssembler.hpp"
  26 #include "asm/macroAssembler.inline.hpp"
  27 #include "ci/ciReplay.hpp"
  28 #include "classfile/javaClasses.hpp"
  29 #include "code/aotCodeCache.hpp"
  30 #include "code/exceptionHandlerTable.hpp"
  31 #include "code/nmethod.hpp"
  32 #include "compiler/compilationFailureInfo.hpp"
  33 #include "compiler/compilationMemoryStatistic.hpp"
  34 #include "compiler/compileBroker.hpp"
  35 #include "compiler/compileLog.hpp"
  36 #include "compiler/compiler_globals.hpp"
  37 #include "compiler/compilerDefinitions.hpp"
  38 #include "compiler/compilerOracle.hpp"
  39 #include "compiler/disassembler.hpp"
  40 #include "compiler/oopMap.hpp"
  41 #include "gc/shared/barrierSet.hpp"
  42 #include "gc/shared/c2/barrierSetC2.hpp"
  43 #include "jfr/jfrEvents.hpp"
  44 #include "jvm_io.h"
  45 #include "memory/allocation.hpp"
  46 #include "memory/arena.hpp"
  47 #include "memory/resourceArea.hpp"
  48 #include "opto/addnode.hpp"
  49 #include "opto/block.hpp"
  50 #include "opto/c2compiler.hpp"
  51 #include "opto/callGenerator.hpp"
  52 #include "opto/callnode.hpp"
  53 #include "opto/castnode.hpp"
  54 #include "opto/cfgnode.hpp"
  55 #include "opto/chaitin.hpp"
  56 #include "opto/compile.hpp"
  57 #include "opto/connode.hpp"
  58 #include "opto/convertnode.hpp"
  59 #include "opto/divnode.hpp"
  60 #include "opto/escape.hpp"
  61 #include "opto/idealGraphPrinter.hpp"
  62 #include "opto/locknode.hpp"
  63 #include "opto/loopnode.hpp"
  64 #include "opto/machnode.hpp"
  65 #include "opto/macro.hpp"
  66 #include "opto/matcher.hpp"
  67 #include "opto/mathexactnode.hpp"
  68 #include "opto/memnode.hpp"
  69 #include "opto/mulnode.hpp"
  70 #include "opto/narrowptrnode.hpp"
  71 #include "opto/node.hpp"
  72 #include "opto/opaquenode.hpp"
  73 #include "opto/opcodes.hpp"
  74 #include "opto/output.hpp"
  75 #include "opto/parse.hpp"
  76 #include "opto/phaseX.hpp"
  77 #include "opto/reachability.hpp"
  78 #include "opto/rootnode.hpp"
  79 #include "opto/runtime.hpp"
  80 #include "opto/stringopts.hpp"
  81 #include "opto/type.hpp"
  82 #include "opto/vector.hpp"
  83 #include "opto/vectornode.hpp"
  84 #include "runtime/globals_extension.hpp"
  85 #include "runtime/sharedRuntime.hpp"
  86 #include "runtime/signature.hpp"
  87 #include "runtime/stubRoutines.hpp"
  88 #include "runtime/timer.hpp"
  89 #include "utilities/align.hpp"
  90 #include "utilities/copy.hpp"
  91 #include "utilities/hashTable.hpp"
  92 #include "utilities/macros.hpp"
  93 
  94 // -------------------- Compile::mach_constant_base_node -----------------------
  95 // Constant table base node singleton.
  96 MachConstantBaseNode* Compile::mach_constant_base_node() {
  97   if (_mach_constant_base_node == nullptr) {
  98     _mach_constant_base_node = new MachConstantBaseNode();
  99     _mach_constant_base_node->add_req(C->root());
 100   }
 101   return _mach_constant_base_node;
 102 }
 103 
 104 
 105 /// Support for intrinsics.
 106 
 107 // Return the index at which m must be inserted (or already exists).
 108 // The sort order is by the address of the ciMethod, with is_virtual as minor key.
 109 class IntrinsicDescPair {
 110  private:
 111   ciMethod* _m;
 112   bool _is_virtual;
 113  public:
 114   IntrinsicDescPair(ciMethod* m, bool is_virtual) : _m(m), _is_virtual(is_virtual) {}
 115   static int compare(IntrinsicDescPair* const& key, CallGenerator* const& elt) {
 116     ciMethod* m= elt->method();
 117     ciMethod* key_m = key->_m;
 118     if (key_m < m)      return -1;
 119     else if (key_m > m) return 1;
 120     else {
 121       bool is_virtual = elt->is_virtual();
 122       bool key_virtual = key->_is_virtual;
 123       if (key_virtual < is_virtual)      return -1;
 124       else if (key_virtual > is_virtual) return 1;
 125       else                               return 0;
 126     }
 127   }
 128 };
 129 int Compile::intrinsic_insertion_index(ciMethod* m, bool is_virtual, bool& found) {
 130 #ifdef ASSERT
 131   for (int i = 1; i < _intrinsics.length(); i++) {
 132     CallGenerator* cg1 = _intrinsics.at(i-1);
 133     CallGenerator* cg2 = _intrinsics.at(i);
 134     assert(cg1->method() != cg2->method()
 135            ? cg1->method()     < cg2->method()
 136            : cg1->is_virtual() < cg2->is_virtual(),
 137            "compiler intrinsics list must stay sorted");
 138   }
 139 #endif
 140   IntrinsicDescPair pair(m, is_virtual);
 141   return _intrinsics.find_sorted<IntrinsicDescPair*, IntrinsicDescPair::compare>(&pair, found);
 142 }
 143 
 144 void Compile::register_intrinsic(CallGenerator* cg) {
 145   bool found = false;
 146   int index = intrinsic_insertion_index(cg->method(), cg->is_virtual(), found);
 147   assert(!found, "registering twice");
 148   _intrinsics.insert_before(index, cg);
 149   assert(find_intrinsic(cg->method(), cg->is_virtual()) == cg, "registration worked");
 150 }
 151 
 152 CallGenerator* Compile::find_intrinsic(ciMethod* m, bool is_virtual) {
 153   assert(m->is_loaded(), "don't try this on unloaded methods");
 154   if (_intrinsics.length() > 0) {
 155     bool found = false;
 156     int index = intrinsic_insertion_index(m, is_virtual, found);
 157      if (found) {
 158       return _intrinsics.at(index);
 159     }
 160   }
 161   // Lazily create intrinsics for intrinsic IDs well-known in the runtime.
 162   if (m->intrinsic_id() != vmIntrinsics::_none &&
 163       m->intrinsic_id() <= vmIntrinsics::LAST_COMPILER_INLINE) {
 164     CallGenerator* cg = make_vm_intrinsic(m, is_virtual);
 165     if (cg != nullptr) {
 166       // Save it for next time:
 167       register_intrinsic(cg);
 168       return cg;
 169     } else {
 170       gather_intrinsic_statistics(m->intrinsic_id(), is_virtual, _intrinsic_disabled);
 171     }
 172   }
 173   return nullptr;
 174 }
 175 
 176 // Compile::make_vm_intrinsic is defined in library_call.cpp.
 177 
 178 #ifndef PRODUCT
 179 // statistics gathering...
 180 
 181 juint  Compile::_intrinsic_hist_count[vmIntrinsics::number_of_intrinsics()] = {0};
 182 jubyte Compile::_intrinsic_hist_flags[vmIntrinsics::number_of_intrinsics()] = {0};
 183 
 184 inline int as_int(vmIntrinsics::ID id) {
 185   return vmIntrinsics::as_int(id);
 186 }
 187 
 188 bool Compile::gather_intrinsic_statistics(vmIntrinsics::ID id, bool is_virtual, int flags) {
 189   assert(id > vmIntrinsics::_none && id < vmIntrinsics::ID_LIMIT, "oob");
 190   int oflags = _intrinsic_hist_flags[as_int(id)];
 191   assert(flags != 0, "what happened?");
 192   if (is_virtual) {
 193     flags |= _intrinsic_virtual;
 194   }
 195   bool changed = (flags != oflags);
 196   if ((flags & _intrinsic_worked) != 0) {
 197     juint count = (_intrinsic_hist_count[as_int(id)] += 1);
 198     if (count == 1) {
 199       changed = true;           // first time
 200     }
 201     // increment the overall count also:
 202     _intrinsic_hist_count[as_int(vmIntrinsics::_none)] += 1;
 203   }
 204   if (changed) {
 205     if (((oflags ^ flags) & _intrinsic_virtual) != 0) {
 206       // Something changed about the intrinsic's virtuality.
 207       if ((flags & _intrinsic_virtual) != 0) {
 208         // This is the first use of this intrinsic as a virtual call.
 209         if (oflags != 0) {
 210           // We already saw it as a non-virtual, so note both cases.
 211           flags |= _intrinsic_both;
 212         }
 213       } else if ((oflags & _intrinsic_both) == 0) {
 214         // This is the first use of this intrinsic as a non-virtual
 215         flags |= _intrinsic_both;
 216       }
 217     }
 218     _intrinsic_hist_flags[as_int(id)] = (jubyte) (oflags | flags);
 219   }
 220   // update the overall flags also:
 221   _intrinsic_hist_flags[as_int(vmIntrinsics::_none)] |= (jubyte) flags;
 222   return changed;
 223 }
 224 
 225 static char* format_flags(int flags, char* buf) {
 226   buf[0] = 0;
 227   if ((flags & Compile::_intrinsic_worked) != 0)    strcat(buf, ",worked");
 228   if ((flags & Compile::_intrinsic_failed) != 0)    strcat(buf, ",failed");
 229   if ((flags & Compile::_intrinsic_disabled) != 0)  strcat(buf, ",disabled");
 230   if ((flags & Compile::_intrinsic_virtual) != 0)   strcat(buf, ",virtual");
 231   if ((flags & Compile::_intrinsic_both) != 0)      strcat(buf, ",nonvirtual");
 232   if (buf[0] == 0)  strcat(buf, ",");
 233   assert(buf[0] == ',', "must be");
 234   return &buf[1];
 235 }
 236 
 237 void Compile::print_intrinsic_statistics() {
 238   char flagsbuf[100];
 239   ttyLocker ttyl;
 240   if (xtty != nullptr)  xtty->head("statistics type='intrinsic'");
 241   tty->print_cr("Compiler intrinsic usage:");
 242   juint total = _intrinsic_hist_count[as_int(vmIntrinsics::_none)];
 243   if (total == 0)  total = 1;  // avoid div0 in case of no successes
 244   #define PRINT_STAT_LINE(name, c, f) \
 245     tty->print_cr("  %4d (%4.1f%%) %s (%s)", (int)(c), ((c) * 100.0) / total, name, f);
 246   for (auto id : EnumRange<vmIntrinsicID>{}) {
 247     int   flags = _intrinsic_hist_flags[as_int(id)];
 248     juint count = _intrinsic_hist_count[as_int(id)];
 249     if ((flags | count) != 0) {
 250       PRINT_STAT_LINE(vmIntrinsics::name_at(id), count, format_flags(flags, flagsbuf));
 251     }
 252   }
 253   PRINT_STAT_LINE("total", total, format_flags(_intrinsic_hist_flags[as_int(vmIntrinsics::_none)], flagsbuf));
 254   if (xtty != nullptr)  xtty->tail("statistics");
 255 }
 256 
 257 void Compile::print_statistics() {
 258   { ttyLocker ttyl;
 259     if (xtty != nullptr)  xtty->head("statistics type='opto'");
 260     Parse::print_statistics();
 261     PhaseStringOpts::print_statistics();
 262     PhaseCCP::print_statistics();
 263     PhaseRegAlloc::print_statistics();
 264     PhaseOutput::print_statistics();
 265     PhasePeephole::print_statistics();
 266     PhaseIdealLoop::print_statistics();
 267     ConnectionGraph::print_statistics();
 268     PhaseMacroExpand::print_statistics();
 269     if (xtty != nullptr)  xtty->tail("statistics");
 270   }
 271   if (_intrinsic_hist_flags[as_int(vmIntrinsics::_none)] != 0) {
 272     // put this under its own <statistics> element.
 273     print_intrinsic_statistics();
 274   }
 275 }
 276 #endif //PRODUCT
 277 
 278 void Compile::gvn_replace_by(Node* n, Node* nn) {
 279   for (DUIterator_Last imin, i = n->last_outs(imin); i >= imin; ) {
 280     Node* use = n->last_out(i);
 281     bool is_in_table = initial_gvn()->hash_delete(use);
 282     uint uses_found = 0;
 283     for (uint j = 0; j < use->len(); j++) {
 284       if (use->in(j) == n) {
 285         if (j < use->req())
 286           use->set_req(j, nn);
 287         else
 288           use->set_prec(j, nn);
 289         uses_found++;
 290       }
 291     }
 292     if (is_in_table) {
 293       // reinsert into table
 294       initial_gvn()->hash_find_insert(use);
 295     }
 296     record_for_igvn(use);
 297     PhaseIterGVN::add_users_of_use_to_worklist(nn, use, *_igvn_worklist);
 298     i -= uses_found;    // we deleted 1 or more copies of this edge
 299   }
 300 }
 301 
 302 
 303 // Identify all nodes that are reachable from below, useful.
 304 // Use breadth-first pass that records state in a Unique_Node_List,
 305 // recursive traversal is slower.
 306 void Compile::identify_useful_nodes(Unique_Node_List &useful) {
 307   int estimated_worklist_size = live_nodes();
 308   useful.map( estimated_worklist_size, nullptr );  // preallocate space
 309 
 310   // Initialize worklist
 311   if (root() != nullptr)  { useful.push(root()); }
 312   // If 'top' is cached, declare it useful to preserve cached node
 313   if (cached_top_node())  { useful.push(cached_top_node()); }
 314 
 315   // Push all useful nodes onto the list, breadthfirst
 316   for( uint next = 0; next < useful.size(); ++next ) {
 317     assert( next < unique(), "Unique useful nodes < total nodes");
 318     Node *n  = useful.at(next);
 319     uint max = n->len();
 320     for( uint i = 0; i < max; ++i ) {
 321       Node *m = n->in(i);
 322       if (not_a_node(m))  continue;
 323       useful.push(m);
 324     }
 325   }
 326 }
 327 
 328 // Update dead_node_list with any missing dead nodes using useful
 329 // list. Consider all non-useful nodes to be useless i.e., dead nodes.
 330 void Compile::update_dead_node_list(Unique_Node_List &useful) {
 331   uint max_idx = unique();
 332   VectorSet& useful_node_set = useful.member_set();
 333 
 334   for (uint node_idx = 0; node_idx < max_idx; node_idx++) {
 335     // If node with index node_idx is not in useful set,
 336     // mark it as dead in dead node list.
 337     if (!useful_node_set.test(node_idx)) {
 338       record_dead_node(node_idx);
 339     }
 340   }
 341 }
 342 
 343 void Compile::remove_useless_late_inlines(GrowableArray<CallGenerator*>* inlines, Unique_Node_List &useful) {
 344   int shift = 0;
 345   for (int i = 0; i < inlines->length(); i++) {
 346     CallGenerator* cg = inlines->at(i);
 347     if (useful.member(cg->call_node())) {
 348       if (shift > 0) {
 349         inlines->at_put(i - shift, cg);
 350       }
 351     } else {
 352       shift++; // skip over the dead element
 353     }
 354   }
 355   if (shift > 0) {
 356     inlines->trunc_to(inlines->length() - shift); // remove last elements from compacted array
 357   }
 358 }
 359 
 360 void Compile::remove_useless_late_inlines(GrowableArray<CallGenerator*>* inlines, Node* dead) {
 361   assert(dead != nullptr && dead->is_Call(), "sanity");
 362   int found = 0;
 363   for (int i = 0; i < inlines->length(); i++) {
 364     if (inlines->at(i)->call_node() == dead) {
 365       inlines->remove_at(i);
 366       found++;
 367       NOT_DEBUG( break; ) // elements are unique, so exit early
 368     }
 369   }
 370   assert(found <= 1, "not unique");
 371 }
 372 
 373 template<typename N, ENABLE_IF_SDEFN(std::is_base_of<Node, N>::value)>
 374 void Compile::remove_useless_nodes(GrowableArray<N*>& node_list, Unique_Node_List& useful) {
 375   for (int i = node_list.length() - 1; i >= 0; i--) {
 376     N* node = node_list.at(i);
 377     if (!useful.member(node)) {
 378       node_list.delete_at(i); // replaces i-th with last element which is known to be useful (already processed)
 379     }
 380   }
 381 }
 382 
 383 void Compile::remove_useless_node(Node* dead) {
 384   remove_modified_node(dead);
 385 
 386   // Constant node that has no out-edges and has only one in-edge from
 387   // root is usually dead. However, sometimes reshaping walk makes
 388   // it reachable by adding use edges. So, we will NOT count Con nodes
 389   // as dead to be conservative about the dead node count at any
 390   // given time.
 391   if (!dead->is_Con()) {
 392     record_dead_node(dead->_idx);
 393   }
 394   if (dead->is_macro()) {
 395     remove_macro_node(dead);
 396   }
 397   if (dead->is_expensive()) {
 398     remove_expensive_node(dead);
 399   }
 400   if (dead->is_ReachabilityFence()) {
 401     remove_reachability_fence(dead->as_ReachabilityFence());
 402   }
 403   if (dead->is_OpaqueTemplateAssertionPredicate()) {
 404     remove_template_assertion_predicate_opaque(dead->as_OpaqueTemplateAssertionPredicate());
 405   }
 406   if (dead->is_ParsePredicate()) {
 407     remove_parse_predicate(dead->as_ParsePredicate());
 408   }
 409   if (dead->for_post_loop_opts_igvn()) {
 410     remove_from_post_loop_opts_igvn(dead);
 411   }
 412   if (dead->for_merge_stores_igvn()) {
 413     remove_from_merge_stores_igvn(dead);
 414   }
 415   if (dead->is_Call()) {
 416     remove_useless_late_inlines(                &_late_inlines, dead);
 417     remove_useless_late_inlines(         &_string_late_inlines, dead);
 418     remove_useless_late_inlines(         &_boxing_late_inlines, dead);
 419     remove_useless_late_inlines(&_vector_reboxing_late_inlines, dead);
 420 
 421     if (dead->is_CallStaticJava()) {
 422       remove_unstable_if_trap(dead->as_CallStaticJava(), false);
 423     }
 424   }
 425   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 426   bs->unregister_potential_barrier_node(dead);
 427 }
 428 
 429 // Disconnect all useless nodes by disconnecting those at the boundary.
 430 void Compile::disconnect_useless_nodes(Unique_Node_List& useful, Unique_Node_List& worklist, const Unique_Node_List* root_and_safepoints) {
 431   uint next = 0;
 432   while (next < useful.size()) {
 433     Node *n = useful.at(next++);
 434     if (n->is_SafePoint()) {
 435       // We're done with a parsing phase. Replaced nodes are not valid
 436       // beyond that point.
 437       n->as_SafePoint()->delete_replaced_nodes();
 438     }
 439     // Use raw traversal of out edges since this code removes out edges
 440     int max = n->outcnt();
 441     for (int j = 0; j < max; ++j) {
 442       Node* child = n->raw_out(j);
 443       if (!useful.member(child)) {
 444         assert(!child->is_top() || child != top(),
 445                "If top is cached in Compile object it is in useful list");
 446         // Only need to remove this out-edge to the useless node
 447         n->raw_del_out(j);
 448         --j;
 449         --max;
 450         if (child->is_data_proj_of_pure_function(n)) {
 451           worklist.push(n);
 452         }
 453       }
 454     }
 455     if (n->outcnt() == 1 && n->has_special_unique_user()) {
 456       assert(useful.member(n->unique_out()), "do not push a useless node");
 457       worklist.push(n->unique_out());
 458     }
 459   }
 460 
 461   remove_useless_nodes(_macro_nodes,        useful); // remove useless macro nodes
 462   remove_useless_nodes(_parse_predicates,   useful); // remove useless Parse Predicate nodes
 463   // Remove useless Template Assertion Predicate opaque nodes
 464   remove_useless_nodes(_template_assertion_predicate_opaques, useful);
 465   remove_useless_nodes(_expensive_nodes,    useful); // remove useless expensive nodes
 466   remove_useless_nodes(_reachability_fences, useful); // remove useless node recorded for post loop opts IGVN pass
 467   remove_useless_nodes(_for_post_loop_igvn, useful); // remove useless node recorded for post loop opts IGVN pass
 468   remove_useless_nodes(_for_merge_stores_igvn, useful); // remove useless node recorded for merge stores IGVN pass
 469   remove_useless_unstable_if_traps(useful);          // remove useless unstable_if traps
 470   remove_useless_coarsened_locks(useful);            // remove useless coarsened locks nodes
 471 #ifdef ASSERT
 472   if (_modified_nodes != nullptr) {
 473     _modified_nodes->remove_useless_nodes(useful.member_set());
 474   }
 475 #endif
 476 
 477   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 478   bs->eliminate_useless_gc_barriers(useful, this);
 479   // clean up the late inline lists
 480   remove_useless_late_inlines(                &_late_inlines, useful);
 481   remove_useless_late_inlines(         &_string_late_inlines, useful);
 482   remove_useless_late_inlines(         &_boxing_late_inlines, useful);
 483   remove_useless_late_inlines(&_vector_reboxing_late_inlines, useful);
 484   DEBUG_ONLY(verify_graph_edges(true /*check for no_dead_code*/, root_and_safepoints);)
 485 }
 486 
 487 // ============================================================================
 488 //------------------------------CompileWrapper---------------------------------
 489 class CompileWrapper : public StackObj {
 490   Compile *const _compile;
 491  public:
 492   CompileWrapper(Compile* compile);
 493 
 494   ~CompileWrapper();
 495 };
 496 
 497 CompileWrapper::CompileWrapper(Compile* compile) : _compile(compile) {
 498   // the Compile* pointer is stored in the current ciEnv:
 499   ciEnv* env = compile->env();
 500   assert(env == ciEnv::current(), "must already be a ciEnv active");
 501   assert(env->compiler_data() == nullptr, "compile already active?");
 502   env->set_compiler_data(compile);
 503   assert(compile == Compile::current(), "sanity");
 504 
 505   compile->set_type_dict(nullptr);
 506   compile->set_clone_map(new Dict(cmpkey, hashkey, _compile->comp_arena()));
 507   compile->clone_map().set_clone_idx(0);
 508   compile->set_type_last_size(0);
 509   compile->set_last_tf(nullptr, nullptr);
 510   compile->set_indexSet_arena(nullptr);
 511   compile->set_indexSet_free_block_list(nullptr);
 512   compile->init_type_arena();
 513   Type::Initialize(compile);
 514   _compile->begin_method();
 515   _compile->clone_map().set_debug(_compile->has_method() && _compile->directive()->CloneMapDebugOption);
 516 }
 517 CompileWrapper::~CompileWrapper() {
 518   // simulate crash during compilation
 519   assert(CICrashAt < 0 || _compile->compile_id() != CICrashAt, "just as planned");
 520 
 521   _compile->end_method();
 522   _compile->env()->set_compiler_data(nullptr);
 523 }
 524 
 525 
 526 //----------------------------print_compile_messages---------------------------
 527 void Compile::print_compile_messages() {
 528 #ifndef PRODUCT
 529   // Check if recompiling
 530   if (!subsume_loads() && PrintOpto) {
 531     // Recompiling without allowing machine instructions to subsume loads
 532     tty->print_cr("*********************************************************");
 533     tty->print_cr("** Bailout: Recompile without subsuming loads          **");
 534     tty->print_cr("*********************************************************");
 535   }
 536   if ((do_escape_analysis() != DoEscapeAnalysis) && PrintOpto) {
 537     // Recompiling without escape analysis
 538     tty->print_cr("*********************************************************");
 539     tty->print_cr("** Bailout: Recompile without escape analysis          **");
 540     tty->print_cr("*********************************************************");
 541   }
 542   if (do_iterative_escape_analysis() != DoEscapeAnalysis && PrintOpto) {
 543     // Recompiling without iterative escape analysis
 544     tty->print_cr("*********************************************************");
 545     tty->print_cr("** Bailout: Recompile without iterative escape analysis**");
 546     tty->print_cr("*********************************************************");
 547   }
 548   if (do_reduce_allocation_merges() != ReduceAllocationMerges && PrintOpto) {
 549     // Recompiling without reducing allocation merges
 550     tty->print_cr("*********************************************************");
 551     tty->print_cr("** Bailout: Recompile without reduce allocation merges **");
 552     tty->print_cr("*********************************************************");
 553   }
 554   if ((eliminate_boxing() != EliminateAutoBox) && PrintOpto) {
 555     // Recompiling without boxing elimination
 556     tty->print_cr("*********************************************************");
 557     tty->print_cr("** Bailout: Recompile without boxing elimination       **");
 558     tty->print_cr("*********************************************************");
 559   }
 560   if ((do_locks_coarsening() != EliminateLocks) && PrintOpto) {
 561     // Recompiling without locks coarsening
 562     tty->print_cr("*********************************************************");
 563     tty->print_cr("** Bailout: Recompile without locks coarsening         **");
 564     tty->print_cr("*********************************************************");
 565   }
 566   if (env()->break_at_compile()) {
 567     // Open the debugger when compiling this method.
 568     tty->print("### Breaking when compiling: ");
 569     method()->print_short_name();
 570     tty->cr();
 571     BREAKPOINT;
 572   }
 573 
 574   if( PrintOpto ) {
 575     if (is_osr_compilation()) {
 576       tty->print("[OSR]%3d", _compile_id);
 577     } else {
 578       tty->print("%3d", _compile_id);
 579     }
 580   }
 581 #endif
 582 }
 583 
 584 #ifndef PRODUCT
 585 void Compile::print_phase(const char* phase_name) {
 586   tty->print_cr("%u.\t%s", ++_phase_counter, phase_name);
 587 }
 588 
 589 void Compile::print_ideal_ir(const char* compile_phase_name) const {
 590   // keep the following output all in one block
 591   // This output goes directly to the tty, not the compiler log.
 592   // To enable tools to match it up with the compilation activity,
 593   // be sure to tag this tty output with the compile ID.
 594 
 595   // Node dumping can cause a safepoint, which can break the tty lock.
 596   // Buffer all node dumps, so that all safepoints happen before we lock.
 597   ResourceMark rm;
 598   stringStream ss;
 599 
 600   if (_output == nullptr) {
 601     ss.print_cr("AFTER: %s", compile_phase_name);
 602     // Print out all nodes in ascending order of index.
 603     // It is important that we traverse both inputs and outputs of nodes,
 604     // so that we reach all nodes that are connected to Root.
 605     root()->dump_bfs(MaxNodeLimit, nullptr, "-+S$", &ss);
 606   } else {
 607     // Dump the node blockwise if we have a scheduling
 608     _output->print_scheduling(&ss);
 609   }
 610 
 611   // Check that the lock is not broken by a safepoint.
 612   NoSafepointVerifier nsv;
 613   ttyLocker ttyl;
 614   if (xtty != nullptr) {
 615     xtty->head("ideal compile_id='%d'%s compile_phase='%s'",
 616                compile_id(),
 617                is_osr_compilation() ? " compile_kind='osr'" : "",
 618                compile_phase_name);
 619   }
 620 
 621   tty->print("%s", ss.as_string());
 622 
 623   if (xtty != nullptr) {
 624     xtty->tail("ideal");
 625   }
 626 }
 627 #endif
 628 
 629 // ============================================================================
 630 //------------------------------Compile standard-------------------------------
 631 
 632 // Compile a method.  entry_bci is -1 for normal compilations and indicates
 633 // the continuation bci for on stack replacement.
 634 
 635 
 636 Compile::Compile(ciEnv* ci_env, ciMethod* target, int osr_bci,
 637                  Options options, DirectiveSet* directive)
 638     : Phase(Compiler),
 639       _compile_id(ci_env->compile_id()),
 640       _options(options),
 641       _method(target),
 642       _entry_bci(osr_bci),
 643       _ilt(nullptr),
 644       _stub_function(nullptr),
 645       _stub_name(nullptr),
 646       _stub_id(StubId::NO_STUBID),
 647       _stub_entry_point(nullptr),
 648       _max_node_limit(MaxNodeLimit),
 649       _node_count_inlining_cutoff(NodeCountInliningCutoff),
 650       _post_loop_opts_phase(false),
 651       _merge_stores_phase(false),
 652       _allow_macro_nodes(true),
 653       _inlining_progress(false),
 654       _inlining_incrementally(false),
 655       _do_cleanup(false),
 656       _has_reserved_stack_access(target->has_reserved_stack_access()),
 657 #ifndef PRODUCT
 658       _igv_idx(0),
 659       _trace_opto_output(directive->TraceOptoOutputOption),
 660 #endif
 661       _clinit_barrier_on_entry(false),
 662       _stress_seed(0),
 663       _comp_arena(mtCompiler, Arena::Tag::tag_comp),
 664       _barrier_set_state(BarrierSet::barrier_set()->barrier_set_c2()->create_barrier_state(comp_arena())),
 665       _env(ci_env),
 666       _directive(directive),
 667       _log(ci_env->log()),
 668       _first_failure_details(nullptr),
 669       _intrinsics(comp_arena(), 0, 0, nullptr),
 670       _macro_nodes(comp_arena(), 8, 0, nullptr),
 671       _parse_predicates(comp_arena(), 8, 0, nullptr),
 672       _template_assertion_predicate_opaques(comp_arena(), 8, 0, nullptr),
 673       _expensive_nodes(comp_arena(), 8, 0, nullptr),
 674       _reachability_fences(comp_arena(), 8, 0, nullptr),
 675       _for_post_loop_igvn(comp_arena(), 8, 0, nullptr),
 676       _for_merge_stores_igvn(comp_arena(), 8, 0, nullptr),
 677       _unstable_if_traps(comp_arena(), 8, 0, nullptr),
 678       _coarsened_locks(comp_arena(), 8, 0, nullptr),
 679       _congraph(nullptr),
 680       NOT_PRODUCT(_igv_printer(nullptr) COMMA)
 681       _unique(0),
 682       _dead_node_count(0),
 683       _dead_node_list(comp_arena()),
 684       _node_arena_one(mtCompiler, Arena::Tag::tag_node),
 685       _node_arena_two(mtCompiler, Arena::Tag::tag_node),
 686       _node_arena(&_node_arena_one),
 687       _mach_constant_base_node(nullptr),
 688       _Compile_types(mtCompiler, Arena::Tag::tag_type),
 689       _initial_gvn(nullptr),
 690       _igvn_worklist(nullptr),
 691       _types(nullptr),
 692       _node_hash(nullptr),
 693       _late_inlines(comp_arena(), 2, 0, nullptr),
 694       _string_late_inlines(comp_arena(), 2, 0, nullptr),
 695       _boxing_late_inlines(comp_arena(), 2, 0, nullptr),
 696       _vector_reboxing_late_inlines(comp_arena(), 2, 0, nullptr),
 697       _late_inlines_pos(0),
 698       _has_mh_late_inlines(false),
 699       _oom(false),
 700       _replay_inline_data(nullptr),
 701       _inline_printer(this),
 702       _java_calls(0),
 703       _inner_loops(0),
 704       _FIRST_STACK_mask(comp_arena()),
 705       _interpreter_frame_size(0),
 706       _regmask_arena(mtCompiler, Arena::Tag::tag_regmask),
 707       _output(nullptr)
 708 #ifndef PRODUCT
 709       ,
 710       _in_dump_cnt(0)
 711 #endif
 712 {
 713   C = this;
 714   CompileWrapper cw(this);
 715 
 716   TraceTime t1("Total compilation time", &_t_totalCompilation, CITime, CITimeVerbose);
 717   TraceTime t2(nullptr, &_t_methodCompilation, CITime, false);
 718 
 719 #if defined(SUPPORT_ASSEMBLY) || defined(SUPPORT_ABSTRACT_ASSEMBLY)
 720   bool print_opto_assembly = directive->PrintOptoAssemblyOption;
 721   // We can always print a disassembly, either abstract (hex dump) or
 722   // with the help of a suitable hsdis library. Thus, we should not
 723   // couple print_assembly and print_opto_assembly controls.
 724   // But: always print opto and regular assembly on compile command 'print'.
 725   bool print_assembly = directive->PrintAssemblyOption;
 726   set_print_assembly(print_opto_assembly || print_assembly);
 727 #else
 728   set_print_assembly(false); // must initialize.
 729 #endif
 730 
 731 #ifndef PRODUCT
 732   set_parsed_irreducible_loop(false);
 733 #endif
 734 
 735   if (directive->ReplayInlineOption) {
 736     _replay_inline_data = ciReplay::load_inline_data(method(), entry_bci(), ci_env->comp_level());
 737   }
 738   set_print_inlining(directive->PrintInliningOption || PrintOptoInlining);
 739   set_print_intrinsics(directive->PrintIntrinsicsOption);
 740   set_has_irreducible_loop(true); // conservative until build_loop_tree() reset it
 741 
 742   if (ProfileTraps) {
 743     // Make sure the method being compiled gets its own MDO,
 744     // so we can at least track the decompile_count().
 745     method()->ensure_method_data();
 746   }
 747 
 748   if (StressLCM || StressGCM || StressIGVN || StressCCP ||
 749       StressIncrementalInlining || StressMacroExpansion ||
 750       StressMacroElimination || StressUnstableIfTraps ||
 751       StressBailout || StressLoopPeeling || StressCountedLoop ||
 752       StressEliminateAllocations) {
 753     initialize_stress_seed(directive);
 754   }
 755 
 756   Init(/*do_aliasing=*/ true);
 757 
 758   print_compile_messages();
 759 
 760   _ilt = InlineTree::build_inline_tree_root();
 761 
 762   // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
 763   assert(num_alias_types() >= AliasIdxRaw, "");
 764 
 765 #define MINIMUM_NODE_HASH  1023
 766 
 767   // GVN that will be run immediately on new nodes
 768   uint estimated_size = method()->code_size()*4+64;
 769   estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
 770   _igvn_worklist = new (comp_arena()) Unique_Node_List(comp_arena());
 771   _types = new (comp_arena()) Type_Array(comp_arena());
 772   _node_hash = new (comp_arena()) NodeHash(comp_arena(), estimated_size);
 773   PhaseGVN gvn;
 774   set_initial_gvn(&gvn);
 775 
 776   { // Scope for timing the parser
 777     TracePhase tp(_t_parser);
 778 
 779     // Put top into the hash table ASAP.
 780     initial_gvn()->transform(top());
 781 
 782     // Set up tf(), start(), and find a CallGenerator.
 783     CallGenerator* cg = nullptr;
 784     if (is_osr_compilation()) {
 785       const TypeTuple *domain = StartOSRNode::osr_domain();
 786       const TypeTuple *range = TypeTuple::make_range(method()->signature());
 787       init_tf(TypeFunc::make(domain, range));
 788       StartNode* s = new StartOSRNode(root(), domain);
 789       initial_gvn()->set_type_bottom(s);
 790       verify_start(s);
 791       cg = CallGenerator::for_osr(method(), entry_bci());
 792     } else {
 793       // Normal case.
 794       init_tf(TypeFunc::make(method()));
 795       StartNode* s = new StartNode(root(), tf()->domain());
 796       initial_gvn()->set_type_bottom(s);
 797       verify_start(s);
 798       float past_uses = method()->interpreter_invocation_count();
 799       float expected_uses = past_uses;
 800       cg = CallGenerator::for_inline(method(), expected_uses);
 801     }
 802     if (failing())  return;
 803     if (cg == nullptr) {
 804       const char* reason = InlineTree::check_can_parse(method());
 805       assert(reason != nullptr, "expect reason for parse failure");
 806       stringStream ss;
 807       ss.print("cannot parse method: %s", reason);
 808       record_method_not_compilable(ss.as_string());
 809       return;
 810     }
 811 
 812     gvn.set_type(root(), root()->bottom_type());
 813 
 814     JVMState* jvms = build_start_state(start(), tf());
 815     if ((jvms = cg->generate(jvms)) == nullptr) {
 816       assert(failure_reason() != nullptr, "expect reason for parse failure");
 817       stringStream ss;
 818       ss.print("method parse failed: %s", failure_reason());
 819       record_method_not_compilable(ss.as_string() DEBUG_ONLY(COMMA true));
 820       return;
 821     }
 822     GraphKit kit(jvms);
 823 
 824     if (!kit.stopped()) {
 825       // Accept return values, and transfer control we know not where.
 826       // This is done by a special, unique ReturnNode bound to root.
 827       return_values(kit.jvms());
 828     }
 829 
 830     if (kit.has_exceptions()) {
 831       // Any exceptions that escape from this call must be rethrown
 832       // to whatever caller is dynamically above us on the stack.
 833       // This is done by a special, unique RethrowNode bound to root.
 834       rethrow_exceptions(kit.transfer_exceptions_into_jvms());
 835     }
 836 
 837     assert(IncrementalInline || (_late_inlines.length() == 0 && !has_mh_late_inlines()), "incremental inlining is off");
 838 
 839     if (_late_inlines.length() == 0 && !has_mh_late_inlines() && !failing() && has_stringbuilder()) {
 840       inline_string_calls(true);
 841     }
 842 
 843     if (failing())  return;
 844 
 845     // Remove clutter produced by parsing.
 846     if (!failing()) {
 847       ResourceMark rm;
 848       PhaseRemoveUseless pru(initial_gvn(), *igvn_worklist());
 849     }
 850   }
 851 
 852   // Note:  Large methods are capped off in do_one_bytecode().
 853   if (failing())  return;
 854 
 855   // After parsing, node notes are no longer automagic.
 856   // They must be propagated by register_new_node_with_optimizer(),
 857   // clone(), or the like.
 858   set_default_node_notes(nullptr);
 859 
 860 #ifndef PRODUCT
 861   if (should_print_igv(1)) {
 862     _igv_printer->print_inlining();
 863   }
 864 #endif
 865 
 866   if (failing())  return;
 867   NOT_PRODUCT( verify_graph_edges(); )
 868 
 869   // Now optimize
 870   Optimize();
 871   if (failing())  return;
 872   NOT_PRODUCT( verify_graph_edges(); )
 873 
 874 #ifndef PRODUCT
 875   if (should_print_ideal()) {
 876     print_ideal_ir("PrintIdeal");
 877   }
 878 #endif
 879 
 880   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 881   bs->final_refinement(this);
 882 
 883 #ifdef ASSERT
 884   bs->verify_gc_barriers(this, BarrierSetC2::BeforeCodeGen);
 885 #endif
 886 
 887   // Dump compilation data to replay it.
 888   if (directive->DumpReplayOption) {
 889     env()->dump_replay_data(_compile_id);
 890   }
 891   if (directive->DumpInlineOption && (ilt() != nullptr)) {
 892     env()->dump_inline_data(_compile_id);
 893   }
 894 
 895   // Now that we know the size of all the monitors we can add a fixed slot
 896   // for the original deopt pc.
 897   int next_slot = fixed_slots() + (sizeof(address) / VMRegImpl::stack_slot_size);
 898   set_fixed_slots(next_slot);
 899 
 900   // Compute when to use implicit null checks. Used by matching trap based
 901   // nodes and NullCheck optimization.
 902   set_allowed_deopt_reasons();
 903 
 904   // Now generate code
 905   Code_Gen();
 906 }
 907 
 908 // C2 uses runtime stubs serialized generation to initialize its static tables
 909 // shared by all compilations, like Type::_shared_type_dict.
 910 // At least one stub have to be completely generated to execute intialization
 911 // before we can skip the rest stubs generation by loading AOT cached stubs.
 912 
 913 static bool c2_do_stub_init_complete = false;
 914 
 915 //------------------------------Compile----------------------------------------
 916 // Compile a runtime stub
 917 Compile::Compile(ciEnv* ci_env,
 918                  TypeFunc_generator generator,
 919                  address stub_function,
 920                  const char* stub_name,
 921                  StubId stub_id,
 922                  int is_fancy_jump,
 923                  bool pass_tls,
 924                  bool return_pc,
 925                  DirectiveSet* directive)
 926     : Phase(Compiler),
 927       _compile_id(0),
 928       _options(Options::for_runtime_stub()),
 929       _method(nullptr),
 930       _entry_bci(InvocationEntryBci),
 931       _stub_function(stub_function),
 932       _stub_name(stub_name),
 933       _stub_id(stub_id),
 934       _stub_entry_point(nullptr),
 935       _max_node_limit(MaxNodeLimit),
 936       _node_count_inlining_cutoff(NodeCountInliningCutoff),
 937       _post_loop_opts_phase(false),
 938       _merge_stores_phase(false),
 939       _allow_macro_nodes(true),
 940       _inlining_progress(false),
 941       _inlining_incrementally(false),
 942       _has_reserved_stack_access(false),
 943 #ifndef PRODUCT
 944       _igv_idx(0),
 945       _trace_opto_output(directive->TraceOptoOutputOption),
 946 #endif
 947       _clinit_barrier_on_entry(false),
 948       _stress_seed(0),
 949       _comp_arena(mtCompiler, Arena::Tag::tag_comp),
 950       _barrier_set_state(BarrierSet::barrier_set()->barrier_set_c2()->create_barrier_state(comp_arena())),
 951       _env(ci_env),
 952       _directive(directive),
 953       _log(ci_env->log()),
 954       _first_failure_details(nullptr),
 955       _reachability_fences(comp_arena(), 8, 0, nullptr),
 956       _for_post_loop_igvn(comp_arena(), 8, 0, nullptr),
 957       _for_merge_stores_igvn(comp_arena(), 8, 0, nullptr),
 958       _congraph(nullptr),
 959       NOT_PRODUCT(_igv_printer(nullptr) COMMA)
 960       _unique(0),
 961       _dead_node_count(0),
 962       _dead_node_list(comp_arena()),
 963       _node_arena_one(mtCompiler, Arena::Tag::tag_node),
 964       _node_arena_two(mtCompiler, Arena::Tag::tag_node),
 965       _node_arena(&_node_arena_one),
 966       _mach_constant_base_node(nullptr),
 967       _Compile_types(mtCompiler, Arena::Tag::tag_type),
 968       _initial_gvn(nullptr),
 969       _igvn_worklist(nullptr),
 970       _types(nullptr),
 971       _node_hash(nullptr),
 972       _has_mh_late_inlines(false),
 973       _oom(false),
 974       _replay_inline_data(nullptr),
 975       _inline_printer(this),
 976       _java_calls(0),
 977       _inner_loops(0),
 978       _FIRST_STACK_mask(comp_arena()),
 979       _interpreter_frame_size(0),
 980       _regmask_arena(mtCompiler, Arena::Tag::tag_regmask),
 981       _output(nullptr),
 982 #ifndef PRODUCT
 983       _in_dump_cnt(0),
 984 #endif
 985       _allowed_reasons(0) {
 986   C = this;
 987 
 988   // try to reuse an existing stub
 989   if (c2_do_stub_init_complete) {
 990     BlobId blob_id = StubInfo::blob(_stub_id);
 991     CodeBlob* blob = AOTCodeCache::load_code_blob(AOTCodeEntry::C2Blob, blob_id);
 992     if (blob != nullptr) {
 993       RuntimeStub* rs = blob->as_runtime_stub();
 994       _stub_entry_point = rs->entry_point();
 995       return;
 996     }
 997   }
 998 
 999   TraceTime t1(nullptr, &_t_totalCompilation, CITime, false);
1000   TraceTime t2(nullptr, &_t_stubCompilation, CITime, false);
1001 
1002 #ifndef PRODUCT
1003   set_print_assembly(PrintFrameConverterAssembly);
1004   set_parsed_irreducible_loop(false);
1005 #else
1006   set_print_assembly(false); // Must initialize.
1007 #endif
1008   set_has_irreducible_loop(false); // no loops
1009 
1010   CompileWrapper cw(this);
1011   Init(/*do_aliasing=*/ false);
1012   init_tf((*generator)());
1013 
1014   _igvn_worklist = new (comp_arena()) Unique_Node_List(comp_arena());
1015   _types = new (comp_arena()) Type_Array(comp_arena());
1016   _node_hash = new (comp_arena()) NodeHash(comp_arena(), 255);
1017 
1018   if (StressLCM || StressGCM || StressBailout) {
1019     initialize_stress_seed(directive);
1020   }
1021 
1022   {
1023     PhaseGVN gvn;
1024     set_initial_gvn(&gvn);    // not significant, but GraphKit guys use it pervasively
1025     gvn.transform(top());
1026 
1027     GraphKit kit;
1028     kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
1029   }
1030 
1031   NOT_PRODUCT( verify_graph_edges(); )
1032 
1033   Code_Gen();
1034 
1035   // First successful stub generation will set it to `true`
1036   // and it will stay `true` after that.
1037   c2_do_stub_init_complete = c2_do_stub_init_complete || (_stub_entry_point != nullptr);
1038 }
1039 
1040 Compile::~Compile() {
1041   delete _first_failure_details;
1042 };
1043 
1044 //------------------------------Init-------------------------------------------
1045 // Prepare for a single compilation
1046 void Compile::Init(bool aliasing) {
1047   _do_aliasing = aliasing;
1048   _unique  = 0;
1049   _regalloc = nullptr;
1050 
1051   _tf      = nullptr;  // filled in later
1052   _top     = nullptr;  // cached later
1053   _matcher = nullptr;  // filled in later
1054   _cfg     = nullptr;  // filled in later
1055 
1056   _node_note_array = nullptr;
1057   _default_node_notes = nullptr;
1058   DEBUG_ONLY( _modified_nodes = nullptr; ) // Used in Optimize()
1059 
1060   _immutable_memory = nullptr; // filled in at first inquiry
1061 
1062 #ifdef ASSERT
1063   _phase_optimize_finished = false;
1064   _phase_verify_ideal_loop = false;
1065   _exception_backedge = false;
1066   _type_verify = nullptr;
1067 #endif
1068 
1069   // Globally visible Nodes
1070   // First set TOP to null to give safe behavior during creation of RootNode
1071   set_cached_top_node(nullptr);
1072   set_root(new RootNode());
1073   // Now that you have a Root to point to, create the real TOP
1074   set_cached_top_node( new ConNode(Type::TOP) );
1075   set_recent_alloc(nullptr, nullptr);
1076 
1077   // Create Debug Information Recorder to record scopes, oopmaps, etc.
1078   env()->set_oop_recorder(new OopRecorder(env()->arena()));
1079   env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
1080   env()->set_dependencies(new Dependencies(env()));
1081 
1082   _fixed_slots = 0;
1083   set_has_split_ifs(false);
1084   set_has_loops(false); // first approximation
1085   set_has_stringbuilder(false);
1086   set_has_boxed_value(false);
1087   _trap_can_recompile = false;  // no traps emitted yet
1088   _major_progress = true; // start out assuming good things will happen
1089   set_has_unsafe_access(false);
1090   set_max_vector_size(0);
1091   set_clear_upper_avx(false);  //false as default for clear upper bits of ymm registers
1092   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
1093   set_decompile_count(0);
1094 
1095 #ifndef PRODUCT
1096   _phase_counter = 0;
1097   Copy::zero_to_bytes(_igv_phase_iter, sizeof(_igv_phase_iter));
1098 #endif
1099 
1100   set_do_freq_based_layout(_directive->BlockLayoutByFrequencyOption);
1101   _loop_opts_cnt = LoopOptsCount;
1102   set_do_inlining(Inline);
1103   set_max_inline_size(MaxInlineSize);
1104   set_freq_inline_size(FreqInlineSize);
1105   set_do_scheduling(OptoScheduling);
1106 
1107   set_do_vector_loop(false);
1108   set_has_monitors(false);
1109   set_has_scoped_access(false);
1110 
1111   if (AllowVectorizeOnDemand) {
1112     if (has_method() && _directive->VectorizeOption) {
1113       set_do_vector_loop(true);
1114       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());})
1115     } else if (has_method() && method()->name() != nullptr &&
1116                method()->intrinsic_id() == vmIntrinsics::_forEachRemaining) {
1117       set_do_vector_loop(true);
1118     }
1119   }
1120   set_use_cmove(UseCMoveUnconditionally /* || do_vector_loop()*/); //TODO: consider do_vector_loop() mandate use_cmove unconditionally
1121   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());})
1122 
1123   _max_node_limit = _directive->MaxNodeLimitOption;
1124 
1125   if (VM_Version::supports_fast_class_init_checks() && has_method() && !is_osr_compilation() && method()->needs_clinit_barrier()) {
1126     set_clinit_barrier_on_entry(true);
1127   }
1128   if (debug_info()->recording_non_safepoints()) {
1129     set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
1130                         (comp_arena(), 8, 0, nullptr));
1131     set_default_node_notes(Node_Notes::make(this));
1132   }
1133 
1134   const int grow_ats = 16;
1135   _max_alias_types = grow_ats;
1136   _alias_types   = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
1137   AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType,  grow_ats);
1138   Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
1139   {
1140     for (int i = 0; i < grow_ats; i++)  _alias_types[i] = &ats[i];
1141   }
1142   // Initialize the first few types.
1143   _alias_types[AliasIdxTop]->Init(AliasIdxTop, nullptr);
1144   _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
1145   _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
1146   _num_alias_types = AliasIdxRaw+1;
1147   // Zero out the alias type cache.
1148   Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
1149   // A null adr_type hits in the cache right away.  Preload the right answer.
1150   probe_alias_cache(nullptr)->_index = AliasIdxTop;
1151 }
1152 
1153 #ifdef ASSERT
1154 // Verify that the current StartNode is valid.
1155 void Compile::verify_start(StartNode* s) const {
1156   assert(failing_internal() || s == start(), "should be StartNode");
1157 }
1158 #endif
1159 
1160 /**
1161  * Return the 'StartNode'. We must not have a pending failure, since the ideal graph
1162  * can be in an inconsistent state, i.e., we can get segmentation faults when traversing
1163  * the ideal graph.
1164  */
1165 StartNode* Compile::start() const {
1166   assert (!failing_internal() || C->failure_is_artificial(), "Must not have pending failure. Reason is: %s", failure_reason());
1167   for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
1168     Node* start = root()->fast_out(i);
1169     if (start->is_Start()) {
1170       return start->as_Start();
1171     }
1172   }
1173   fatal("Did not find Start node!");
1174   return nullptr;
1175 }
1176 
1177 //-------------------------------immutable_memory-------------------------------------
1178 // Access immutable memory
1179 Node* Compile::immutable_memory() {
1180   if (_immutable_memory != nullptr) {
1181     return _immutable_memory;
1182   }
1183   StartNode* s = start();
1184   for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
1185     Node *p = s->fast_out(i);
1186     if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
1187       _immutable_memory = p;
1188       return _immutable_memory;
1189     }
1190   }
1191   ShouldNotReachHere();
1192   return nullptr;
1193 }
1194 
1195 //----------------------set_cached_top_node------------------------------------
1196 // Install the cached top node, and make sure Node::is_top works correctly.
1197 void Compile::set_cached_top_node(Node* tn) {
1198   if (tn != nullptr)  verify_top(tn);
1199   Node* old_top = _top;
1200   _top = tn;
1201   // Calling Node::setup_is_top allows the nodes the chance to adjust
1202   // their _out arrays.
1203   if (_top != nullptr)     _top->setup_is_top();
1204   if (old_top != nullptr)  old_top->setup_is_top();
1205   assert(_top == nullptr || top()->is_top(), "");
1206 }
1207 
1208 #ifdef ASSERT
1209 uint Compile::count_live_nodes_by_graph_walk() {
1210   Unique_Node_List useful(comp_arena());
1211   // Get useful node list by walking the graph.
1212   identify_useful_nodes(useful);
1213   return useful.size();
1214 }
1215 
1216 void Compile::print_missing_nodes() {
1217 
1218   // Return if CompileLog is null and PrintIdealNodeCount is false.
1219   if ((_log == nullptr) && (! PrintIdealNodeCount)) {
1220     return;
1221   }
1222 
1223   // This is an expensive function. It is executed only when the user
1224   // specifies VerifyIdealNodeCount option or otherwise knows the
1225   // additional work that needs to be done to identify reachable nodes
1226   // by walking the flow graph and find the missing ones using
1227   // _dead_node_list.
1228 
1229   Unique_Node_List useful(comp_arena());
1230   // Get useful node list by walking the graph.
1231   identify_useful_nodes(useful);
1232 
1233   uint l_nodes = C->live_nodes();
1234   uint l_nodes_by_walk = useful.size();
1235 
1236   if (l_nodes != l_nodes_by_walk) {
1237     if (_log != nullptr) {
1238       _log->begin_head("mismatched_nodes count='%d'", abs((int) (l_nodes - l_nodes_by_walk)));
1239       _log->stamp();
1240       _log->end_head();
1241     }
1242     VectorSet& useful_member_set = useful.member_set();
1243     int last_idx = l_nodes_by_walk;
1244     for (int i = 0; i < last_idx; i++) {
1245       if (useful_member_set.test(i)) {
1246         if (_dead_node_list.test(i)) {
1247           if (_log != nullptr) {
1248             _log->elem("mismatched_node_info node_idx='%d' type='both live and dead'", i);
1249           }
1250           if (PrintIdealNodeCount) {
1251             // Print the log message to tty
1252               tty->print_cr("mismatched_node idx='%d' both live and dead'", i);
1253               useful.at(i)->dump();
1254           }
1255         }
1256       }
1257       else if (! _dead_node_list.test(i)) {
1258         if (_log != nullptr) {
1259           _log->elem("mismatched_node_info node_idx='%d' type='neither live nor dead'", i);
1260         }
1261         if (PrintIdealNodeCount) {
1262           // Print the log message to tty
1263           tty->print_cr("mismatched_node idx='%d' type='neither live nor dead'", i);
1264         }
1265       }
1266     }
1267     if (_log != nullptr) {
1268       _log->tail("mismatched_nodes");
1269     }
1270   }
1271 }
1272 void Compile::record_modified_node(Node* n) {
1273   if (_modified_nodes != nullptr && !_inlining_incrementally && !n->is_Con()) {
1274     _modified_nodes->push(n);
1275   }
1276 }
1277 
1278 void Compile::remove_modified_node(Node* n) {
1279   if (_modified_nodes != nullptr) {
1280     _modified_nodes->remove(n);
1281   }
1282 }
1283 #endif
1284 
1285 #ifndef PRODUCT
1286 void Compile::verify_top(Node* tn) const {
1287   if (tn != nullptr) {
1288     assert(tn->is_Con(), "top node must be a constant");
1289     assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
1290     assert(tn->in(0) != nullptr, "must have live top node");
1291   }
1292 }
1293 #endif
1294 
1295 
1296 ///-------------------Managing Per-Node Debug & Profile Info-------------------
1297 
1298 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
1299   guarantee(arr != nullptr, "");
1300   int num_blocks = arr->length();
1301   if (grow_by < num_blocks)  grow_by = num_blocks;
1302   int num_notes = grow_by * _node_notes_block_size;
1303   Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
1304   Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
1305   while (num_notes > 0) {
1306     arr->append(notes);
1307     notes     += _node_notes_block_size;
1308     num_notes -= _node_notes_block_size;
1309   }
1310   assert(num_notes == 0, "exact multiple, please");
1311 }
1312 
1313 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
1314   if (source == nullptr || dest == nullptr)  return false;
1315 
1316   if (dest->is_Con())
1317     return false;               // Do not push debug info onto constants.
1318 
1319 #ifdef ASSERT
1320   // Leave a bread crumb trail pointing to the original node:
1321   if (dest != nullptr && dest != source && dest->debug_orig() == nullptr) {
1322     dest->set_debug_orig(source);
1323   }
1324 #endif
1325 
1326   if (node_note_array() == nullptr)
1327     return false;               // Not collecting any notes now.
1328 
1329   // This is a copy onto a pre-existing node, which may already have notes.
1330   // If both nodes have notes, do not overwrite any pre-existing notes.
1331   Node_Notes* source_notes = node_notes_at(source->_idx);
1332   if (source_notes == nullptr || source_notes->is_clear())  return false;
1333   Node_Notes* dest_notes   = node_notes_at(dest->_idx);
1334   if (dest_notes == nullptr || dest_notes->is_clear()) {
1335     return set_node_notes_at(dest->_idx, source_notes);
1336   }
1337 
1338   Node_Notes merged_notes = (*source_notes);
1339   // The order of operations here ensures that dest notes will win...
1340   merged_notes.update_from(dest_notes);
1341   return set_node_notes_at(dest->_idx, &merged_notes);
1342 }
1343 
1344 
1345 //--------------------------allow_range_check_smearing-------------------------
1346 // Gating condition for coalescing similar range checks.
1347 // Sometimes we try 'speculatively' replacing a series of a range checks by a
1348 // single covering check that is at least as strong as any of them.
1349 // If the optimization succeeds, the simplified (strengthened) range check
1350 // will always succeed.  If it fails, we will deopt, and then give up
1351 // on the optimization.
1352 bool Compile::allow_range_check_smearing() const {
1353   // If this method has already thrown a range-check,
1354   // assume it was because we already tried range smearing
1355   // and it failed.
1356   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
1357   return !already_trapped;
1358 }
1359 
1360 
1361 //------------------------------flatten_alias_type-----------------------------
1362 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
1363   assert(do_aliasing(), "Aliasing should be enabled");
1364   int offset = tj->offset();
1365   TypePtr::PTR ptr = tj->ptr();
1366 
1367   // Known instance (scalarizable allocation) alias only with itself.
1368   bool is_known_inst = tj->isa_oopptr() != nullptr &&
1369                        tj->is_oopptr()->is_known_instance();
1370 
1371   // Process weird unsafe references.
1372   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
1373     assert(InlineUnsafeOps || StressReflectiveCode, "indeterminate pointers come only from unsafe ops");
1374     assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
1375     tj = TypeOopPtr::BOTTOM;
1376     ptr = tj->ptr();
1377     offset = tj->offset();
1378   }
1379 
1380   // Array pointers need some flattening
1381   const TypeAryPtr* ta = tj->isa_aryptr();
1382   if (ta && ta->is_stable()) {
1383     // Erase stability property for alias analysis.
1384     tj = ta = ta->cast_to_stable(false);
1385   }
1386   if( ta && is_known_inst ) {
1387     if ( offset != Type::OffsetBot &&
1388          offset > arrayOopDesc::length_offset_in_bytes() ) {
1389       offset = Type::OffsetBot; // Flatten constant access into array body only
1390       tj = ta = ta->
1391               remove_speculative()->
1392               cast_to_ptr_type(ptr)->
1393               with_offset(offset);
1394     }
1395   } else if (ta != nullptr) {
1396     // Common slices
1397     if (offset == arrayOopDesc::length_offset_in_bytes()) {
1398       return TypeAryPtr::RANGE;
1399     } else if (offset == oopDesc::klass_offset_in_bytes()) {
1400       return TypeInstPtr::KLASS;
1401     } else if (offset == oopDesc::mark_offset_in_bytes()) {
1402       return TypeInstPtr::MARK;
1403     }
1404 
1405     // Remove size and stability
1406     const TypeAry* normalized_ary = TypeAry::make(ta->elem(), TypeInt::POS, false);
1407     // Remove ptr, const_oop, and offset
1408     if (ta->elem() == Type::BOTTOM) {
1409       // Bottom array (meet of int[] and byte[] for example), accesses to it will be done with
1410       // Unsafe. This should alias with all arrays. For now just leave it as it is (this is
1411       // incorrect, see JDK-8331133).
1412       tj = ta = TypeAryPtr::make(TypePtr::BotPTR, nullptr, normalized_ary, nullptr, false, Type::OffsetBot);
1413     } else if (ta->elem()->make_oopptr() != nullptr) {
1414       // Object arrays, all of them share the same slice
1415       const TypeAry* tary = TypeAry::make(TypeInstPtr::BOTTOM, TypeInt::POS, false);
1416       tj = ta = TypeAryPtr::make(TypePtr::BotPTR, nullptr, tary, nullptr, false, Type::OffsetBot);
1417     } else {
1418       // Primitive arrays
1419       tj = ta = TypeAryPtr::make(TypePtr::BotPTR, nullptr, normalized_ary, ta->exact_klass(), true, Type::OffsetBot);
1420     }
1421 
1422     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
1423     // cannot be distinguished by bytecode alone.
1424     if (ta->elem() == TypeInt::BOOL) {
1425       tj = ta = TypeAryPtr::BYTES;
1426     }
1427   }
1428 
1429   // Oop pointers need some flattening
1430   const TypeInstPtr *to = tj->isa_instptr();
1431   if (to && to != TypeOopPtr::BOTTOM) {
1432     ciInstanceKlass* ik = to->instance_klass();
1433     if( ptr == TypePtr::Constant ) {
1434       if (ik != ciEnv::current()->Class_klass() ||
1435           offset < ik->layout_helper_size_in_bytes()) {
1436         // No constant oop pointers (such as Strings); they alias with
1437         // unknown strings.
1438         assert(!is_known_inst, "not scalarizable allocation");
1439         tj = to = to->
1440                 cast_to_instance_id(TypeOopPtr::InstanceBot)->
1441                 remove_speculative()->
1442                 cast_to_ptr_type(TypePtr::BotPTR)->
1443                 cast_to_exactness(false);
1444       }
1445     } else if( is_known_inst ) {
1446       tj = to; // Keep NotNull and klass_is_exact for instance type
1447     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
1448       // During the 2nd round of IterGVN, NotNull castings are removed.
1449       // Make sure the Bottom and NotNull variants alias the same.
1450       // Also, make sure exact and non-exact variants alias the same.
1451       tj = to = to->
1452               remove_speculative()->
1453               cast_to_instance_id(TypeOopPtr::InstanceBot)->
1454               cast_to_ptr_type(TypePtr::BotPTR)->
1455               cast_to_exactness(false);
1456     }
1457     if (to->speculative() != nullptr) {
1458       tj = to = to->remove_speculative();
1459     }
1460     // Canonicalize the holder of this field
1461     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
1462       // First handle header references such as a LoadKlassNode, even if the
1463       // object's klass is unloaded at compile time (4965979).
1464       if (!is_known_inst) { // Do it only for non-instance types
1465         tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, nullptr, offset);
1466       }
1467     } else if (offset < 0 || offset >= ik->layout_helper_size_in_bytes()) {
1468       // Static fields are in the space above the normal instance
1469       // fields in the java.lang.Class instance.
1470       if (ik != ciEnv::current()->Class_klass()) {
1471         to = nullptr;
1472         tj = TypeOopPtr::BOTTOM;
1473         offset = tj->offset();
1474       }
1475     } else {
1476       ciInstanceKlass *canonical_holder = ik->get_canonical_holder(offset);
1477       assert(offset < canonical_holder->layout_helper_size_in_bytes(), "");
1478       assert(tj->offset() == offset, "no change to offset expected");
1479       bool xk = to->klass_is_exact();
1480       int instance_id = to->instance_id();
1481 
1482       // If the input type's class is the holder: if exact, the type only includes interfaces implemented by the holder
1483       // but if not exact, it may include extra interfaces: build new type from the holder class to make sure only
1484       // its interfaces are included.
1485       if (xk && ik->equals(canonical_holder)) {
1486         assert(tj == TypeInstPtr::make(to->ptr(), canonical_holder, is_known_inst, nullptr, offset, instance_id), "exact type should be canonical type");
1487       } else {
1488         assert(xk || !is_known_inst, "Known instance should be exact type");
1489         tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, is_known_inst, nullptr, offset, instance_id);
1490       }
1491     }
1492   }
1493 
1494   // Klass pointers to object array klasses need some flattening
1495   const TypeKlassPtr *tk = tj->isa_klassptr();
1496   if( tk ) {
1497     // If we are referencing a field within a Klass, we need
1498     // to assume the worst case of an Object.  Both exact and
1499     // inexact types must flatten to the same alias class so
1500     // use NotNull as the PTR.
1501     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
1502       tj = tk = TypeInstKlassPtr::make(TypePtr::NotNull,
1503                                        env()->Object_klass(),
1504                                        offset);
1505     }
1506 
1507     if (tk->isa_aryklassptr() && tk->is_aryklassptr()->elem()->isa_klassptr()) {
1508       ciKlass* k = ciObjArrayKlass::make(env()->Object_klass());
1509       if (!k || !k->is_loaded()) {                  // Only fails for some -Xcomp runs
1510         tj = tk = TypeInstKlassPtr::make(TypePtr::NotNull, env()->Object_klass(), offset);
1511       } else {
1512         tj = tk = TypeAryKlassPtr::make(TypePtr::NotNull, tk->is_aryklassptr()->elem(), k, offset);
1513       }
1514     }
1515 
1516     // Check for precise loads from the primary supertype array and force them
1517     // to the supertype cache alias index.  Check for generic array loads from
1518     // the primary supertype array and also force them to the supertype cache
1519     // alias index.  Since the same load can reach both, we need to merge
1520     // these 2 disparate memories into the same alias class.  Since the
1521     // primary supertype array is read-only, there's no chance of confusion
1522     // where we bypass an array load and an array store.
1523     int primary_supers_offset = in_bytes(Klass::primary_supers_offset());
1524     if (offset == Type::OffsetBot ||
1525         (offset >= primary_supers_offset &&
1526          offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
1527         offset == (int)in_bytes(Klass::secondary_super_cache_offset())) {
1528       offset = in_bytes(Klass::secondary_super_cache_offset());
1529       tj = tk = tk->with_offset(offset);
1530     }
1531   }
1532 
1533   // Flatten all Raw pointers together.
1534   if (tj->base() == Type::RawPtr)
1535     tj = TypeRawPtr::BOTTOM;
1536 
1537   if (tj->base() == Type::AnyPtr)
1538     tj = TypePtr::BOTTOM;      // An error, which the caller must check for.
1539 
1540   offset = tj->offset();
1541   assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
1542 
1543   assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
1544           (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
1545           (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
1546           (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
1547           (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1548           (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1549           (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr),
1550           "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
1551   assert( tj->ptr() != TypePtr::TopPTR &&
1552           tj->ptr() != TypePtr::AnyNull &&
1553           tj->ptr() != TypePtr::Null, "No imprecise addresses" );
1554 //    assert( tj->ptr() != TypePtr::Constant ||
1555 //            tj->base() == Type::RawPtr ||
1556 //            tj->base() == Type::KlassPtr, "No constant oop addresses" );
1557 
1558   return tj;
1559 }
1560 
1561 void Compile::AliasType::Init(int i, const TypePtr* at) {
1562   assert(AliasIdxTop <= i && i < Compile::current()->_max_alias_types, "Invalid alias index");
1563   _index = i;
1564   _adr_type = at;
1565   _field = nullptr;
1566   _element = nullptr;
1567   _is_rewritable = true; // default
1568   const TypeOopPtr *atoop = (at != nullptr) ? at->isa_oopptr() : nullptr;
1569   if (atoop != nullptr && atoop->is_known_instance()) {
1570     const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
1571     _general_index = Compile::current()->get_alias_index(gt);
1572   } else {
1573     _general_index = 0;
1574   }
1575 }
1576 
1577 BasicType Compile::AliasType::basic_type() const {
1578   if (element() != nullptr) {
1579     const Type* element = adr_type()->is_aryptr()->elem();
1580     return element->isa_narrowoop() ? T_OBJECT : element->array_element_basic_type();
1581   } if (field() != nullptr) {
1582     return field()->layout_type();
1583   } else {
1584     return T_ILLEGAL; // unknown
1585   }
1586 }
1587 
1588 //---------------------------------print_on------------------------------------
1589 #ifndef PRODUCT
1590 void Compile::AliasType::print_on(outputStream* st) {
1591   if (index() < 10)
1592         st->print("@ <%d> ", index());
1593   else  st->print("@ <%d>",  index());
1594   st->print(is_rewritable() ? "   " : " RO");
1595   int offset = adr_type()->offset();
1596   if (offset == Type::OffsetBot)
1597         st->print(" +any");
1598   else  st->print(" +%-3d", offset);
1599   st->print(" in ");
1600   adr_type()->dump_on(st);
1601   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
1602   if (field() != nullptr && tjp) {
1603     if (tjp->is_instptr()->instance_klass()  != field()->holder() ||
1604         tjp->offset() != field()->offset_in_bytes()) {
1605       st->print(" != ");
1606       field()->print();
1607       st->print(" ***");
1608     }
1609   }
1610 }
1611 
1612 void print_alias_types() {
1613   Compile* C = Compile::current();
1614   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
1615   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
1616     C->alias_type(idx)->print_on(tty);
1617     tty->cr();
1618   }
1619 }
1620 #endif
1621 
1622 
1623 //----------------------------probe_alias_cache--------------------------------
1624 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
1625   intptr_t key = (intptr_t) adr_type;
1626   key ^= key >> logAliasCacheSize;
1627   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
1628 }
1629 
1630 
1631 //-----------------------------grow_alias_types--------------------------------
1632 void Compile::grow_alias_types() {
1633   const int old_ats  = _max_alias_types; // how many before?
1634   const int new_ats  = old_ats;          // how many more?
1635   const int grow_ats = old_ats+new_ats;  // how many now?
1636   _max_alias_types = grow_ats;
1637   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), _alias_types, old_ats, grow_ats);
1638   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
1639   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
1640   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
1641 }
1642 
1643 
1644 //--------------------------------find_alias_type------------------------------
1645 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field) {
1646   if (!do_aliasing()) {
1647     return alias_type(AliasIdxBot);
1648   }
1649 
1650   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1651   if (ace->_adr_type == adr_type) {
1652     return alias_type(ace->_index);
1653   }
1654 
1655   // Handle special cases.
1656   if (adr_type == nullptr)          return alias_type(AliasIdxTop);
1657   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
1658 
1659   // Do it the slow way.
1660   const TypePtr* flat = flatten_alias_type(adr_type);
1661 
1662 #ifdef ASSERT
1663   {
1664     ResourceMark rm;
1665     assert(flat == flatten_alias_type(flat), "not idempotent: adr_type = %s; flat = %s => %s",
1666            Type::str(adr_type), Type::str(flat), Type::str(flatten_alias_type(flat)));
1667     assert(flat != TypePtr::BOTTOM, "cannot alias-analyze an untyped ptr: adr_type = %s",
1668            Type::str(adr_type));
1669     if (flat->isa_oopptr() && !flat->isa_klassptr()) {
1670       const TypeOopPtr* foop = flat->is_oopptr();
1671       // Scalarizable allocations have exact klass always.
1672       bool exact = !foop->klass_is_exact() || foop->is_known_instance();
1673       const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
1674       assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type: foop = %s; xoop = %s",
1675              Type::str(foop), Type::str(xoop));
1676     }
1677   }
1678 #endif
1679 
1680   int idx = AliasIdxTop;
1681   for (int i = 0; i < num_alias_types(); i++) {
1682     if (alias_type(i)->adr_type() == flat) {
1683       idx = i;
1684       break;
1685     }
1686   }
1687 
1688   if (idx == AliasIdxTop) {
1689     if (no_create)  return nullptr;
1690     // Grow the array if necessary.
1691     if (_num_alias_types == _max_alias_types)  grow_alias_types();
1692     // Add a new alias type.
1693     idx = _num_alias_types++;
1694     _alias_types[idx]->Init(idx, flat);
1695     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
1696     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
1697     if (flat->isa_instptr()) {
1698       if (flat->offset() == java_lang_Class::klass_offset()
1699           && flat->is_instptr()->instance_klass() == env()->Class_klass())
1700         alias_type(idx)->set_rewritable(false);
1701     }
1702     if (flat->isa_aryptr()) {
1703 #ifdef ASSERT
1704       const int header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1705       // (T_BYTE has the weakest alignment and size restrictions...)
1706       assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
1707 #endif
1708       if (flat->offset() == TypePtr::OffsetBot) {
1709         alias_type(idx)->set_element(flat->is_aryptr()->elem());
1710       }
1711     }
1712     if (flat->isa_klassptr()) {
1713       if (UseCompactObjectHeaders) {
1714         if (flat->offset() == in_bytes(Klass::prototype_header_offset()))
1715           alias_type(idx)->set_rewritable(false);
1716       }
1717       if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
1718         alias_type(idx)->set_rewritable(false);
1719       if (flat->offset() == in_bytes(Klass::misc_flags_offset()))
1720         alias_type(idx)->set_rewritable(false);
1721       if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
1722         alias_type(idx)->set_rewritable(false);
1723       if (flat->offset() == in_bytes(Klass::secondary_super_cache_offset()))
1724         alias_type(idx)->set_rewritable(false);
1725     }
1726 
1727     if (flat->isa_instklassptr()) {
1728       if (flat->offset() == in_bytes(InstanceKlass::access_flags_offset())) {
1729         alias_type(idx)->set_rewritable(false);
1730       }
1731     }
1732     // %%% (We would like to finalize JavaThread::threadObj_offset(),
1733     // but the base pointer type is not distinctive enough to identify
1734     // references into JavaThread.)
1735 
1736     // Check for final fields.
1737     const TypeInstPtr* tinst = flat->isa_instptr();
1738     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
1739       ciField* field;
1740       if (tinst->const_oop() != nullptr &&
1741           tinst->instance_klass() == ciEnv::current()->Class_klass() &&
1742           tinst->offset() >= (tinst->instance_klass()->layout_helper_size_in_bytes())) {
1743         // static field
1744         ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
1745         field = k->get_field_by_offset(tinst->offset(), true);
1746       } else {
1747         ciInstanceKlass *k = tinst->instance_klass();
1748         field = k->get_field_by_offset(tinst->offset(), false);
1749       }
1750       assert(field == nullptr ||
1751              original_field == nullptr ||
1752              (field->holder() == original_field->holder() &&
1753               field->offset_in_bytes() == original_field->offset_in_bytes() &&
1754               field->is_static() == original_field->is_static()), "wrong field?");
1755       // Set field() and is_rewritable() attributes.
1756       if (field != nullptr)  alias_type(idx)->set_field(field);
1757     }
1758   }
1759 
1760   // Fill the cache for next time.
1761   ace->_adr_type = adr_type;
1762   ace->_index    = idx;
1763   assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
1764 
1765   // Might as well try to fill the cache for the flattened version, too.
1766   AliasCacheEntry* face = probe_alias_cache(flat);
1767   if (face->_adr_type == nullptr) {
1768     face->_adr_type = flat;
1769     face->_index    = idx;
1770     assert(alias_type(flat) == alias_type(idx), "flat type must work too");
1771   }
1772 
1773   return alias_type(idx);
1774 }
1775 
1776 
1777 Compile::AliasType* Compile::alias_type(ciField* field) {
1778   const TypeOopPtr* t;
1779   if (field->is_static())
1780     t = TypeInstPtr::make(field->holder()->java_mirror());
1781   else
1782     t = TypeOopPtr::make_from_klass_raw(field->holder());
1783   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);
1784   assert((field->is_final() || field->is_stable()) == !atp->is_rewritable(), "must get the rewritable bits correct");
1785   return atp;
1786 }
1787 
1788 
1789 //------------------------------have_alias_type--------------------------------
1790 bool Compile::have_alias_type(const TypePtr* adr_type) {
1791   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1792   if (ace->_adr_type == adr_type) {
1793     return true;
1794   }
1795 
1796   // Handle special cases.
1797   if (adr_type == nullptr)             return true;
1798   if (adr_type == TypePtr::BOTTOM)  return true;
1799 
1800   return find_alias_type(adr_type, true, nullptr) != nullptr;
1801 }
1802 
1803 //-----------------------------must_alias--------------------------------------
1804 // True if all values of the given address type are in the given alias category.
1805 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
1806   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1807   if (adr_type == nullptr)              return true;  // null serves as TypePtr::TOP
1808   if (alias_idx == AliasIdxTop)         return false; // the empty category
1809   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
1810 
1811   // the only remaining possible overlap is identity
1812   int adr_idx = get_alias_index(adr_type);
1813   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1814   assert(adr_idx == alias_idx ||
1815          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
1816           && adr_type                       != TypeOopPtr::BOTTOM),
1817          "should not be testing for overlap with an unsafe pointer");
1818   return adr_idx == alias_idx;
1819 }
1820 
1821 //------------------------------can_alias--------------------------------------
1822 // True if any values of the given address type are in the given alias category.
1823 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
1824   if (alias_idx == AliasIdxTop)         return false; // the empty category
1825   if (adr_type == nullptr)              return false; // null serves as TypePtr::TOP
1826   // Known instance doesn't alias with bottom memory
1827   if (alias_idx == AliasIdxBot)         return !adr_type->is_known_instance();                   // the universal category
1828   if (adr_type->base() == Type::AnyPtr) return !C->get_adr_type(alias_idx)->is_known_instance(); // TypePtr::BOTTOM or its twins
1829 
1830   // the only remaining possible overlap is identity
1831   int adr_idx = get_alias_index(adr_type);
1832   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1833   return adr_idx == alias_idx;
1834 }
1835 
1836 // Mark all ParsePredicateNodes as useless. They will later be removed from the graph in IGVN together with their
1837 // uncommon traps if no Runtime Predicates were created from the Parse Predicates.
1838 void Compile::mark_parse_predicate_nodes_useless(PhaseIterGVN& igvn) {
1839   if (parse_predicate_count() == 0) {
1840     return;
1841   }
1842   for (int i = 0; i < parse_predicate_count(); i++) {
1843     ParsePredicateNode* parse_predicate = _parse_predicates.at(i);
1844     parse_predicate->mark_useless(igvn);
1845   }
1846   _parse_predicates.clear();
1847 }
1848 
1849 void Compile::record_for_post_loop_opts_igvn(Node* n) {
1850   if (!n->for_post_loop_opts_igvn()) {
1851     assert(!_for_post_loop_igvn.contains(n), "duplicate");
1852     n->add_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
1853     _for_post_loop_igvn.append(n);
1854   }
1855 }
1856 
1857 void Compile::remove_from_post_loop_opts_igvn(Node* n) {
1858   n->remove_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
1859   _for_post_loop_igvn.remove(n);
1860 }
1861 
1862 void Compile::process_for_post_loop_opts_igvn(PhaseIterGVN& igvn) {
1863   // Verify that all previous optimizations produced a valid graph
1864   // at least to this point, even if no loop optimizations were done.
1865   PhaseIdealLoop::verify(igvn);
1866 
1867   if (_print_phase_loop_opts) {
1868     print_method(PHASE_AFTER_LOOP_OPTS, 2);
1869   }
1870   C->set_post_loop_opts_phase(); // no more loop opts allowed
1871 
1872   assert(!C->major_progress(), "not cleared");
1873 
1874   if (_for_post_loop_igvn.length() > 0) {
1875     while (_for_post_loop_igvn.length() > 0) {
1876       Node* n = _for_post_loop_igvn.pop();
1877       n->remove_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
1878       igvn._worklist.push(n);
1879     }
1880     igvn.optimize();
1881     if (failing()) return;
1882     assert(_for_post_loop_igvn.length() == 0, "no more delayed nodes allowed");
1883     assert(C->parse_predicate_count() == 0, "all parse predicates should have been removed now");
1884 
1885     // Sometimes IGVN sets major progress (e.g., when processing loop nodes).
1886     if (C->major_progress()) {
1887       C->clear_major_progress(); // ensure that major progress is now clear
1888     }
1889   }
1890 }
1891 
1892 void Compile::record_for_merge_stores_igvn(Node* n) {
1893   if (!n->for_merge_stores_igvn()) {
1894     assert(!_for_merge_stores_igvn.contains(n), "duplicate");
1895     n->add_flag(Node::NodeFlags::Flag_for_merge_stores_igvn);
1896     _for_merge_stores_igvn.append(n);
1897   }
1898 }
1899 
1900 void Compile::remove_from_merge_stores_igvn(Node* n) {
1901   n->remove_flag(Node::NodeFlags::Flag_for_merge_stores_igvn);
1902   _for_merge_stores_igvn.remove(n);
1903 }
1904 
1905 // We need to wait with merging stores until RangeCheck smearing has removed the RangeChecks during
1906 // the post loops IGVN phase. If we do it earlier, then there may still be some RangeChecks between
1907 // the stores, and we merge the wrong sequence of stores.
1908 // Example:
1909 //   StoreI RangeCheck StoreI StoreI RangeCheck StoreI
1910 // Apply MergeStores:
1911 //   StoreI RangeCheck [   StoreL  ] RangeCheck StoreI
1912 // Remove more RangeChecks:
1913 //   StoreI            [   StoreL  ]            StoreI
1914 // But now it would have been better to do this instead:
1915 //   [         StoreL       ] [       StoreL         ]
1916 //
1917 // Note: we allow stores to merge in this dedicated IGVN round, and any later IGVN round,
1918 //       since we never unset _merge_stores_phase.
1919 void Compile::process_for_merge_stores_igvn(PhaseIterGVN& igvn) {
1920   C->set_merge_stores_phase();
1921 
1922   if (_for_merge_stores_igvn.length() > 0) {
1923     while (_for_merge_stores_igvn.length() > 0) {
1924       Node* n = _for_merge_stores_igvn.pop();
1925       n->remove_flag(Node::NodeFlags::Flag_for_merge_stores_igvn);
1926       igvn._worklist.push(n);
1927     }
1928     igvn.optimize();
1929     if (failing()) return;
1930     assert(_for_merge_stores_igvn.length() == 0, "no more delayed nodes allowed");
1931     print_method(PHASE_AFTER_MERGE_STORES, 3);
1932   }
1933 }
1934 
1935 void Compile::record_unstable_if_trap(UnstableIfTrap* trap) {
1936   if (OptimizeUnstableIf) {
1937     _unstable_if_traps.append(trap);
1938   }
1939 }
1940 
1941 void Compile::remove_useless_unstable_if_traps(Unique_Node_List& useful) {
1942   for (int i = _unstable_if_traps.length() - 1; i >= 0; i--) {
1943     UnstableIfTrap* trap = _unstable_if_traps.at(i);
1944     Node* n = trap->uncommon_trap();
1945     if (!useful.member(n)) {
1946       _unstable_if_traps.delete_at(i); // replaces i-th with last element which is known to be useful (already processed)
1947     }
1948   }
1949 }
1950 
1951 // Remove the unstable if trap associated with 'unc' from candidates. It is either dead
1952 // or fold-compares case. Return true if succeed or not found.
1953 //
1954 // In rare cases, the found trap has been processed. It is too late to delete it. Return
1955 // false and ask fold-compares to yield.
1956 //
1957 // 'fold-compares' may use the uncommon_trap of the dominating IfNode to cover the fused
1958 // IfNode. This breaks the unstable_if trap invariant: control takes the unstable path
1959 // when deoptimization does happen.
1960 bool Compile::remove_unstable_if_trap(CallStaticJavaNode* unc, bool yield) {
1961   for (int i = 0; i < _unstable_if_traps.length(); ++i) {
1962     UnstableIfTrap* trap = _unstable_if_traps.at(i);
1963     if (trap->uncommon_trap() == unc) {
1964       if (yield && trap->modified()) {
1965         return false;
1966       }
1967       _unstable_if_traps.delete_at(i);
1968       break;
1969     }
1970   }
1971   return true;
1972 }
1973 
1974 // Re-calculate unstable_if traps with the liveness of next_bci, which points to the unlikely path.
1975 // It needs to be done after igvn because fold-compares may fuse uncommon_traps and before renumbering.
1976 void Compile::process_for_unstable_if_traps(PhaseIterGVN& igvn) {
1977   for (int i = _unstable_if_traps.length() - 1; i >= 0; --i) {
1978     UnstableIfTrap* trap = _unstable_if_traps.at(i);
1979     CallStaticJavaNode* unc = trap->uncommon_trap();
1980     int next_bci = trap->next_bci();
1981     bool modified = trap->modified();
1982 
1983     if (next_bci != -1 && !modified) {
1984       assert(!_dead_node_list.test(unc->_idx), "changing a dead node!");
1985       JVMState* jvms = unc->jvms();
1986       ciMethod* method = jvms->method();
1987       ciBytecodeStream iter(method);
1988 
1989       iter.force_bci(jvms->bci());
1990       assert(next_bci == iter.next_bci() || next_bci == iter.get_dest(), "wrong next_bci at unstable_if");
1991       Bytecodes::Code c = iter.cur_bc();
1992       Node* lhs = nullptr;
1993       Node* rhs = nullptr;
1994       if (c == Bytecodes::_if_acmpeq || c == Bytecodes::_if_acmpne) {
1995         lhs = unc->peek_operand(0);
1996         rhs = unc->peek_operand(1);
1997       } else if (c == Bytecodes::_ifnull || c == Bytecodes::_ifnonnull) {
1998         lhs = unc->peek_operand(0);
1999       }
2000 
2001       ResourceMark rm;
2002       const MethodLivenessResult& live_locals = method->liveness_at_bci(next_bci);
2003       assert(live_locals.is_valid(), "broken liveness info");
2004       int len = (int)live_locals.size();
2005 
2006       for (int i = 0; i < len; i++) {
2007         Node* local = unc->local(jvms, i);
2008         // kill local using the liveness of next_bci.
2009         // give up when the local looks like an operand to secure reexecution.
2010         if (!live_locals.at(i) && !local->is_top() && local != lhs && local!= rhs) {
2011           uint idx = jvms->locoff() + i;
2012 #ifdef ASSERT
2013           if (PrintOpto && Verbose) {
2014             tty->print("[unstable_if] kill local#%d: ", idx);
2015             local->dump();
2016             tty->cr();
2017           }
2018 #endif
2019           igvn.replace_input_of(unc, idx, top());
2020           modified = true;
2021         }
2022       }
2023     }
2024 
2025     // keep the mondified trap for late query
2026     if (modified) {
2027       trap->set_modified();
2028     } else {
2029       _unstable_if_traps.delete_at(i);
2030     }
2031   }
2032   igvn.optimize();
2033 }
2034 
2035 // StringOpts and late inlining of string methods
2036 void Compile::inline_string_calls(bool parse_time) {
2037   {
2038     // remove useless nodes to make the usage analysis simpler
2039     ResourceMark rm;
2040     PhaseRemoveUseless pru(initial_gvn(), *igvn_worklist());
2041   }
2042 
2043   {
2044     ResourceMark rm;
2045     print_method(PHASE_BEFORE_STRINGOPTS, 3);
2046     PhaseStringOpts pso(initial_gvn());
2047     print_method(PHASE_AFTER_STRINGOPTS, 3);
2048   }
2049 
2050   // now inline anything that we skipped the first time around
2051   if (!parse_time) {
2052     _late_inlines_pos = _late_inlines.length();
2053   }
2054 
2055   assert(!do_cleanup(), "already set");
2056 
2057   while (_string_late_inlines.length() > 0) {
2058     CallGenerator* cg = _string_late_inlines.pop();
2059     cg->do_late_inline();
2060     if (failing())  return;
2061     set_do_cleanup(false); // ignore and reset
2062   }
2063   _string_late_inlines.trunc_to(0);
2064 }
2065 
2066 // Late inlining of boxing methods
2067 void Compile::inline_boxing_calls(PhaseIterGVN& igvn) {
2068   if (_boxing_late_inlines.length() > 0) {
2069     assert(has_boxed_value(), "inconsistent");
2070 
2071     set_inlining_incrementally(true);
2072 
2073     igvn_worklist()->ensure_empty(); // should be done with igvn
2074 
2075     _late_inlines_pos = _late_inlines.length();
2076 
2077     assert(!do_cleanup(), "already set");
2078 
2079     while (_boxing_late_inlines.length() > 0) {
2080       CallGenerator* cg = _boxing_late_inlines.pop();
2081       cg->do_late_inline();
2082       if (failing())  return;
2083       set_do_cleanup(false); // ignore and reset
2084     }
2085     _boxing_late_inlines.trunc_to(0);
2086 
2087     inline_incrementally_cleanup(igvn);
2088 
2089     set_inlining_incrementally(false);
2090   }
2091 }
2092 
2093 bool Compile::inline_incrementally_one() {
2094   assert(IncrementalInline, "incremental inlining should be on");
2095   assert(_late_inlines.length() > 0, "should have been checked by caller");
2096 
2097   TracePhase tp(_t_incrInline_inline);
2098 
2099   set_inlining_progress(false);
2100   set_do_cleanup(false);
2101 
2102   for (int i = 0; i < _late_inlines.length(); i++) {
2103     _late_inlines_pos = i+1;
2104     CallGenerator* cg = _late_inlines.at(i);
2105     bool is_scheduled_for_igvn_before = C->igvn_worklist()->member(cg->call_node());
2106     bool does_dispatch = cg->is_virtual_late_inline() || cg->is_mh_late_inline();
2107     if (inlining_incrementally() || does_dispatch) { // a call can be either inlined or strength-reduced to a direct call
2108       if (should_stress_inlining()) {
2109         // randomly add repeated inline attempt if stress-inlining
2110         cg->call_node()->set_generator(cg);
2111         C->igvn_worklist()->push(cg->call_node());
2112         continue;
2113       }
2114       cg->do_late_inline();
2115       assert(_late_inlines.at(i) == cg, "no insertions before current position allowed");
2116       if (failing()) {
2117         return false;
2118       } else if (inlining_progress()) {
2119         _late_inlines_pos = i+1; // restore the position in case new elements were inserted
2120         print_method(PHASE_INCREMENTAL_INLINE_STEP, 3, cg->call_node());
2121         break; // process one call site at a time
2122       } else {
2123         bool is_scheduled_for_igvn_after = C->igvn_worklist()->member(cg->call_node());
2124         if (!is_scheduled_for_igvn_before && is_scheduled_for_igvn_after) {
2125           // Avoid potential infinite loop if node already in the IGVN list
2126           assert(false, "scheduled for IGVN during inlining attempt");
2127         } else {
2128           // Ensure call node has not disappeared from IGVN worklist during a failed inlining attempt
2129           assert(!is_scheduled_for_igvn_before || is_scheduled_for_igvn_after, "call node removed from IGVN list during inlining pass");
2130           cg->call_node()->set_generator(cg);
2131         }
2132       }
2133     } else {
2134       // Ignore late inline direct calls when inlining is not allowed.
2135       // They are left in the late inline list when node budget is exhausted until the list is fully drained.
2136     }
2137   }
2138   // Remove processed elements.
2139   _late_inlines.remove_till(_late_inlines_pos);
2140   _late_inlines_pos = 0;
2141 
2142   assert(inlining_progress() || _late_inlines.length() == 0, "no progress");
2143 
2144   bool needs_cleanup = do_cleanup() || over_inlining_cutoff();
2145 
2146   set_inlining_progress(false);
2147   set_do_cleanup(false);
2148 
2149   bool force_cleanup = directive()->IncrementalInlineForceCleanupOption;
2150   return (_late_inlines.length() > 0) && !needs_cleanup && !force_cleanup;
2151 }
2152 
2153 void Compile::inline_incrementally_cleanup(PhaseIterGVN& igvn) {
2154   {
2155     TracePhase tp(_t_incrInline_pru);
2156     ResourceMark rm;
2157     PhaseRemoveUseless pru(initial_gvn(), *igvn_worklist());
2158   }
2159   {
2160     TracePhase tp(_t_incrInline_igvn);
2161     igvn.reset();
2162     igvn.optimize();
2163     if (failing()) return;
2164   }
2165   print_method(PHASE_INCREMENTAL_INLINE_CLEANUP, 3);
2166 }
2167 
2168 template<typename E>
2169 static void shuffle_array(Compile& C, GrowableArray<E>& array) {
2170   if (array.length() < 2) {
2171     return;
2172   }
2173   for (uint i = array.length() - 1; i >= 1; i--) {
2174     uint j = C.random() % (i + 1);
2175     swap(array.at(i), array.at(j));
2176   }
2177 }
2178 
2179 void Compile::shuffle_late_inlines() {
2180   shuffle_array(*C, _late_inlines);
2181 }
2182 
2183 // Perform incremental inlining until bound on number of live nodes is reached
2184 void Compile::inline_incrementally(PhaseIterGVN& igvn) {
2185   TracePhase tp(_t_incrInline);
2186 
2187   set_inlining_incrementally(true);
2188   uint low_live_nodes = 0;
2189 
2190   if (StressIncrementalInlining) {
2191     shuffle_late_inlines();
2192   }
2193 
2194   while (_late_inlines.length() > 0) {
2195     if (live_nodes() > node_count_inlining_cutoff()) {
2196       if (low_live_nodes < node_count_inlining_cutoff() * 8 / 10) {
2197         TracePhase tp(_t_incrInline_ideal);
2198         // PhaseIdealLoop is expensive so we only try it once we are
2199         // out of live nodes and we only try it again if the previous
2200         // helped got the number of nodes down significantly
2201         PhaseIdealLoop::optimize(igvn, LoopOptsNone);
2202         if (failing())  return;
2203         low_live_nodes = live_nodes();
2204         _major_progress = true;
2205       }
2206 
2207       if (live_nodes() > node_count_inlining_cutoff()) {
2208         bool do_print_inlining = print_inlining() || print_intrinsics();
2209         if (do_print_inlining || log() != nullptr) {
2210           // Print inlining message for candidates that we couldn't inline for lack of space.
2211           for (int i = 0; i < _late_inlines.length(); i++) {
2212             CallGenerator* cg = _late_inlines.at(i);
2213             const char* msg = "live nodes > LiveNodeCountInliningCutoff";
2214             if (do_print_inlining) {
2215               inline_printer()->record(cg->method(), cg->call_node()->jvms(), InliningResult::FAILURE, msg);
2216             }
2217             log_late_inline_failure(cg, msg);
2218           }
2219         }
2220         break; // finish
2221       }
2222     }
2223 
2224     igvn_worklist()->ensure_empty(); // should be done with igvn
2225 
2226     if (_late_inlines.length() == 0) {
2227       break; // no more progress
2228     }
2229 
2230     while (inline_incrementally_one()) {
2231       assert(!failing_internal() || failure_is_artificial(), "inconsistent");
2232     }
2233     if (failing())  return;
2234 
2235     inline_incrementally_cleanup(igvn);
2236 
2237     print_method(PHASE_INCREMENTAL_INLINE_STEP, 3);
2238 
2239     if (failing())  return;
2240   }
2241 
2242   igvn_worklist()->ensure_empty(); // should be done with igvn
2243 
2244   if (_string_late_inlines.length() > 0) {
2245     assert(has_stringbuilder(), "inconsistent");
2246 
2247     inline_string_calls(false);
2248 
2249     if (failing())  return;
2250 
2251     inline_incrementally_cleanup(igvn);
2252   }
2253 
2254   set_inlining_incrementally(false);
2255 }
2256 
2257 void Compile::process_late_inline_calls_no_inline(PhaseIterGVN& igvn) {
2258   // "inlining_incrementally() == false" is used to signal that no inlining is allowed
2259   // (see LateInlineVirtualCallGenerator::do_late_inline_check() for details).
2260   // Tracking and verification of modified nodes is disabled by setting "_modified_nodes == nullptr"
2261   // as if "inlining_incrementally() == true" were set.
2262   assert(inlining_incrementally() == false, "not allowed");
2263   assert(_modified_nodes == nullptr, "not allowed");
2264   assert(_late_inlines.length() > 0, "sanity");
2265 
2266   if (StressIncrementalInlining) {
2267     shuffle_late_inlines();
2268   }
2269 
2270   while (_late_inlines.length() > 0) {
2271     igvn_worklist()->ensure_empty(); // should be done with igvn
2272 
2273     while (inline_incrementally_one()) {
2274       assert(!failing_internal() || failure_is_artificial(), "inconsistent");
2275     }
2276     if (failing())  return;
2277 
2278     inline_incrementally_cleanup(igvn);
2279   }
2280 }
2281 
2282 bool Compile::optimize_loops(PhaseIterGVN& igvn, LoopOptsMode mode) {
2283   if (_loop_opts_cnt > 0) {
2284     while (major_progress() && (_loop_opts_cnt > 0)) {
2285       TracePhase tp(_t_idealLoop);
2286       PhaseIdealLoop::optimize(igvn, mode);
2287       _loop_opts_cnt--;
2288       if (failing())  return false;
2289       if (major_progress()) {
2290         print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
2291       }
2292     }
2293   }
2294   return true;
2295 }
2296 
2297 // Remove edges from "root" to each SafePoint at a backward branch.
2298 // They were inserted during parsing (see add_safepoint()) to make
2299 // infinite loops without calls or exceptions visible to root, i.e.,
2300 // useful.
2301 void Compile::remove_root_to_sfpts_edges(PhaseIterGVN& igvn) {
2302   Node *r = root();
2303   if (r != nullptr) {
2304     for (uint i = r->req(); i < r->len(); ++i) {
2305       Node *n = r->in(i);
2306       if (n != nullptr && n->is_SafePoint()) {
2307         r->rm_prec(i);
2308         if (n->outcnt() == 0) {
2309           igvn.remove_dead_node(n, PhaseIterGVN::NodeOrigin::Graph);
2310         }
2311         --i;
2312       }
2313     }
2314     // Parsing may have added top inputs to the root node (Path
2315     // leading to the Halt node proven dead). Make sure we get a
2316     // chance to clean them up.
2317     igvn._worklist.push(r);
2318     igvn.optimize();
2319   }
2320 }
2321 
2322 //------------------------------Optimize---------------------------------------
2323 // Given a graph, optimize it.
2324 void Compile::Optimize() {
2325   TracePhase tp(_t_optimizer);
2326 
2327 #ifndef PRODUCT
2328   if (env()->break_at_compile()) {
2329     BREAKPOINT;
2330   }
2331 
2332 #endif
2333 
2334   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
2335 #ifdef ASSERT
2336   bs->verify_gc_barriers(this, BarrierSetC2::BeforeOptimize);
2337 #endif
2338 
2339   ResourceMark rm;
2340 
2341   NOT_PRODUCT( verify_graph_edges(); )
2342 
2343   print_method(PHASE_AFTER_PARSING, 1);
2344 
2345  {
2346   // Iterative Global Value Numbering, including ideal transforms
2347   PhaseIterGVN igvn;
2348 #ifdef ASSERT
2349   _modified_nodes = new (comp_arena()) Unique_Node_List(comp_arena());
2350 #endif
2351   {
2352     TracePhase tp(_t_iterGVN);
2353     igvn.optimize(true);
2354   }
2355 
2356   if (failing())  return;
2357 
2358   print_method(PHASE_ITER_GVN1, 2);
2359 
2360   process_for_unstable_if_traps(igvn);
2361 
2362   if (failing())  return;
2363 
2364   inline_incrementally(igvn);
2365 
2366   print_method(PHASE_INCREMENTAL_INLINE, 2);
2367 
2368   if (failing())  return;
2369 
2370   if (eliminate_boxing()) {
2371     // Inline valueOf() methods now.
2372     inline_boxing_calls(igvn);
2373 
2374     if (failing())  return;
2375 
2376     if (AlwaysIncrementalInline || StressIncrementalInlining) {
2377       inline_incrementally(igvn);
2378     }
2379 
2380     print_method(PHASE_INCREMENTAL_BOXING_INLINE, 2);
2381 
2382     if (failing())  return;
2383   }
2384 
2385   // Remove the speculative part of types and clean up the graph from
2386   // the extra CastPP nodes whose only purpose is to carry them. Do
2387   // that early so that optimizations are not disrupted by the extra
2388   // CastPP nodes.
2389   remove_speculative_types(igvn);
2390 
2391   if (failing())  return;
2392 
2393   // No more new expensive nodes will be added to the list from here
2394   // so keep only the actual candidates for optimizations.
2395   cleanup_expensive_nodes(igvn);
2396 
2397   if (failing())  return;
2398 
2399   assert(EnableVectorSupport || !has_vbox_nodes(), "sanity");
2400   if (EnableVectorSupport && has_vbox_nodes()) {
2401     TracePhase tp(_t_vector);
2402     PhaseVector pv(igvn);
2403     pv.optimize_vector_boxes();
2404     if (failing())  return;
2405     print_method(PHASE_ITER_GVN_AFTER_VECTOR, 2);
2406   }
2407   assert(!has_vbox_nodes(), "sanity");
2408 
2409   if (!failing() && RenumberLiveNodes && live_nodes() + NodeLimitFudgeFactor < unique()) {
2410     Compile::TracePhase tp(_t_renumberLive);
2411     igvn_worklist()->ensure_empty(); // should be done with igvn
2412     {
2413       ResourceMark rm;
2414       PhaseRenumberLive prl(initial_gvn(), *igvn_worklist());
2415     }
2416     igvn.reset();
2417     igvn.optimize(true);
2418     if (failing()) return;
2419   }
2420 
2421   // Now that all inlining is over and no PhaseRemoveUseless will run, cut edge from root to loop
2422   // safepoints
2423   remove_root_to_sfpts_edges(igvn);
2424 
2425   if (failing())  return;
2426 
2427   _print_phase_loop_opts = has_loops();
2428   if (_print_phase_loop_opts) {
2429     print_method(PHASE_BEFORE_LOOP_OPTS, 2);
2430   }
2431 
2432   // Perform escape analysis
2433   if (do_escape_analysis() && ConnectionGraph::has_candidates(this)) {
2434     if (has_loops()) {
2435       // Cleanup graph (remove dead nodes).
2436       TracePhase tp(_t_idealLoop);
2437       PhaseIdealLoop::optimize(igvn, LoopOptsMaxUnroll);
2438       if (failing())  return;
2439     }
2440     bool progress;
2441     print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
2442     do {
2443       ConnectionGraph::do_analysis(this, &igvn);
2444 
2445       if (failing())  return;
2446 
2447       int mcount = macro_count(); // Record number of allocations and locks before IGVN
2448 
2449       // Optimize out fields loads from scalar replaceable allocations.
2450       igvn.optimize(true);
2451       print_method(PHASE_ITER_GVN_AFTER_EA, 2);
2452 
2453       if (failing()) return;
2454 
2455       if (congraph() != nullptr && macro_count() > 0) {
2456         TracePhase tp(_t_macroEliminate);
2457         PhaseMacroExpand mexp(igvn);
2458         mexp.eliminate_macro_nodes();
2459         if (failing()) return;
2460         print_method(PHASE_AFTER_MACRO_ELIMINATION, 2);
2461 
2462         igvn.set_delay_transform(false);
2463         igvn.optimize();
2464         if (failing()) return;
2465 
2466         print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
2467       }
2468 
2469       ConnectionGraph::verify_ram_nodes(this, root());
2470       if (failing())  return;
2471 
2472       progress = do_iterative_escape_analysis() &&
2473                  (macro_count() < mcount) &&
2474                  ConnectionGraph::has_candidates(this);
2475       // Try again if candidates exist and made progress
2476       // by removing some allocations and/or locks.
2477     } while (progress);
2478   }
2479 
2480   // Loop transforms on the ideal graph.  Range Check Elimination,
2481   // peeling, unrolling, etc.
2482 
2483   // Set loop opts counter
2484   if((_loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
2485     {
2486       TracePhase tp(_t_idealLoop);
2487       PhaseIdealLoop::optimize(igvn, LoopOptsDefault);
2488       _loop_opts_cnt--;
2489       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP1, 2);
2490       if (failing())  return;
2491     }
2492     // Loop opts pass if partial peeling occurred in previous pass
2493     if(PartialPeelLoop && major_progress() && (_loop_opts_cnt > 0)) {
2494       TracePhase tp(_t_idealLoop);
2495       PhaseIdealLoop::optimize(igvn, LoopOptsSkipSplitIf);
2496       _loop_opts_cnt--;
2497       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP2, 2);
2498       if (failing())  return;
2499     }
2500     // Loop opts pass for loop-unrolling before CCP
2501     if(major_progress() && (_loop_opts_cnt > 0)) {
2502       TracePhase tp(_t_idealLoop);
2503       PhaseIdealLoop::optimize(igvn, LoopOptsSkipSplitIf);
2504       _loop_opts_cnt--;
2505       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP3, 2);
2506     }
2507     if (!failing()) {
2508       // Verify that last round of loop opts produced a valid graph
2509       PhaseIdealLoop::verify(igvn);
2510     }
2511   }
2512   if (failing())  return;
2513 
2514   // Conditional Constant Propagation;
2515   print_method(PHASE_BEFORE_CCP1, 2);
2516   PhaseCCP ccp( &igvn );
2517   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
2518   {
2519     TracePhase tp(_t_ccp);
2520     ccp.do_transform();
2521   }
2522   print_method(PHASE_CCP1, 2);
2523 
2524   assert( true, "Break here to ccp.dump_old2new_map()");
2525 
2526   // Iterative Global Value Numbering, including ideal transforms
2527   {
2528     TracePhase tp(_t_iterGVN2);
2529     igvn.reset_from_igvn(&ccp);
2530     igvn.optimize(true);
2531   }
2532   print_method(PHASE_ITER_GVN2, 2);
2533 
2534   if (failing())  return;
2535 
2536   // Loop transforms on the ideal graph.  Range Check Elimination,
2537   // peeling, unrolling, etc.
2538   if (!optimize_loops(igvn, LoopOptsDefault)) {
2539     return;
2540   }
2541 
2542   C->clear_major_progress(); // ensure that major progress is now clear
2543 
2544   process_for_post_loop_opts_igvn(igvn);
2545 
2546   if (failing())  return;
2547 
2548   // Once loop optimizations are over, it is safe to get rid of all reachability fence nodes and
2549   // migrate reachability edges to safepoints.
2550   if (OptimizeReachabilityFences && _reachability_fences.length() > 0) {
2551     TracePhase tp1(_t_idealLoop);
2552     TracePhase tp2(_t_reachability);
2553     PhaseIdealLoop::optimize(igvn, PostLoopOptsExpandReachabilityFences);
2554     print_method(PHASE_EXPAND_REACHABILITY_FENCES, 2);
2555     if (failing())  return;
2556     assert(_reachability_fences.length() == 0 || PreserveReachabilityFencesOnConstants, "no RF nodes allowed");
2557   }
2558 
2559   process_for_merge_stores_igvn(igvn);
2560 
2561   if (failing())  return;
2562 
2563 #ifdef ASSERT
2564   bs->verify_gc_barriers(this, BarrierSetC2::BeforeMacroExpand);
2565 #endif
2566 
2567   {
2568     TracePhase tp(_t_macroExpand);
2569     print_method(PHASE_BEFORE_MACRO_EXPANSION, 3);
2570     PhaseMacroExpand  mex(igvn);
2571     // Do not allow new macro nodes once we start to eliminate and expand
2572     C->reset_allow_macro_nodes();
2573     // Last attempt to eliminate macro nodes before expand
2574     mex.eliminate_macro_nodes();
2575     if (failing()) {
2576       return;
2577     }
2578     mex.eliminate_opaque_looplimit_macro_nodes();
2579     if (failing()) {
2580       return;
2581     }
2582     print_method(PHASE_AFTER_MACRO_ELIMINATION, 2);
2583     if (mex.expand_macro_nodes()) {
2584       assert(failing(), "must bail out w/ explicit message");
2585       return;
2586     }
2587     print_method(PHASE_AFTER_MACRO_EXPANSION, 2);
2588   }
2589 
2590   {
2591     TracePhase tp(_t_barrierExpand);
2592     if (bs->expand_barriers(this, igvn)) {
2593       assert(failing(), "must bail out w/ explicit message");
2594       return;
2595     }
2596     print_method(PHASE_BARRIER_EXPANSION, 2);
2597   }
2598 
2599   if (C->max_vector_size() > 0) {
2600     C->optimize_logic_cones(igvn);
2601     igvn.optimize();
2602     if (failing()) return;
2603   }
2604 
2605   DEBUG_ONLY( _modified_nodes = nullptr; )
2606 
2607   assert(igvn._worklist.size() == 0, "not empty");
2608 
2609   if (_late_inlines.length() > 0) {
2610     // More opportunities to optimize virtual and MH calls.
2611     // Though it's maybe too late to perform inlining, strength-reducing them to direct calls is still an option.
2612     process_late_inline_calls_no_inline(igvn);
2613     if (failing())  return;
2614   }
2615   assert(_late_inlines.length() == 0, "late inline queue must be drained");
2616  } // (End scope of igvn; run destructor if necessary for asserts.)
2617 
2618  check_no_dead_use();
2619 
2620  // We will never use the NodeHash table any more. Clear it so that final_graph_reshaping does not have
2621  // to remove hashes to unlock nodes for modifications.
2622  C->node_hash()->clear();
2623 
2624  // A method with only infinite loops has no edges entering loops from root
2625  {
2626    TracePhase tp(_t_graphReshaping);
2627    if (final_graph_reshaping()) {
2628      assert(failing(), "must bail out w/ explicit message");
2629      return;
2630    }
2631  }
2632 
2633  print_method(PHASE_OPTIMIZE_FINISHED, 2);
2634  DEBUG_ONLY(set_phase_optimize_finished();)
2635 }
2636 
2637 #ifdef ASSERT
2638 void Compile::check_no_dead_use() const {
2639   ResourceMark rm;
2640   Unique_Node_List wq;
2641   wq.push(root());
2642   for (uint i = 0; i < wq.size(); ++i) {
2643     Node* n = wq.at(i);
2644     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
2645       Node* u = n->fast_out(j);
2646       if (u->outcnt() == 0 && !u->is_Con()) {
2647         u->dump();
2648         fatal("no reachable node should have no use");
2649       }
2650       wq.push(u);
2651     }
2652   }
2653 }
2654 #endif
2655 
2656 void Compile::inline_vector_reboxing_calls() {
2657   assert(!do_cleanup(), "already set");
2658   if (C->_vector_reboxing_late_inlines.length() > 0) {
2659     _late_inlines_pos = C->_late_inlines.length();
2660     while (_vector_reboxing_late_inlines.length() > 0) {
2661       CallGenerator* cg = _vector_reboxing_late_inlines.pop();
2662       cg->do_late_inline();
2663       if (failing())  return;
2664       assert(!do_cleanup(), "should not be set");
2665       print_method(PHASE_INLINE_VECTOR_REBOX, 3, cg->call_node());
2666     }
2667     _vector_reboxing_late_inlines.trunc_to(0);
2668   }
2669 }
2670 
2671 bool Compile::has_vbox_nodes() {
2672   if (C->_vector_reboxing_late_inlines.length() > 0) {
2673     return true;
2674   }
2675   for (int macro_idx = C->macro_count() - 1; macro_idx >= 0; macro_idx--) {
2676     Node * n = C->macro_node(macro_idx);
2677     assert(n->is_macro(), "only macro nodes expected here");
2678     if (n->Opcode() == Op_VectorUnbox || n->Opcode() == Op_VectorBox || n->Opcode() == Op_VectorBoxAllocate) {
2679       return true;
2680     }
2681   }
2682   return false;
2683 }
2684 
2685 //---------------------------- Bitwise operation packing optimization ---------------------------
2686 
2687 static bool is_vector_unary_bitwise_op(Node* n) {
2688   return n->Opcode() == Op_XorV &&
2689          VectorNode::is_vector_bitwise_not_pattern(n);
2690 }
2691 
2692 static bool is_vector_binary_bitwise_op(Node* n) {
2693   switch (n->Opcode()) {
2694     case Op_AndV:
2695     case Op_OrV:
2696       return true;
2697 
2698     case Op_XorV:
2699       return !is_vector_unary_bitwise_op(n);
2700 
2701     default:
2702       return false;
2703   }
2704 }
2705 
2706 static bool is_vector_ternary_bitwise_op(Node* n) {
2707   return n->Opcode() == Op_MacroLogicV;
2708 }
2709 
2710 static bool is_vector_bitwise_op(Node* n) {
2711   return is_vector_unary_bitwise_op(n)  ||
2712          is_vector_binary_bitwise_op(n) ||
2713          is_vector_ternary_bitwise_op(n);
2714 }
2715 
2716 static bool is_vector_bitwise_cone_root(Node* n) {
2717   if (n->bottom_type()->isa_pvectmask() || !is_vector_bitwise_op(n)) {
2718     return false;
2719   }
2720   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2721     if (is_vector_bitwise_op(n->fast_out(i))) {
2722       return false;
2723     }
2724   }
2725   return true;
2726 }
2727 
2728 static uint collect_unique_inputs(Node* n, Unique_Node_List& inputs) {
2729   uint cnt = 0;
2730   if (is_vector_bitwise_op(n)) {
2731     uint inp_cnt = n->is_predicated_vector() ? n->req()-1 : n->req();
2732     if (VectorNode::is_vector_bitwise_not_pattern(n)) {
2733       assert(n->req() == (n->is_predicated_vector() ? 4 : 3), "must have 2 data inputs");
2734       Node* opnd = VectorNode::is_all_ones_vector(n->in(1)) ? n->in(2) : n->in(1);
2735       if (!inputs.member(opnd)) {
2736         inputs.push(opnd);
2737         cnt++;
2738       }
2739       assert(cnt <= 1, "not unary");
2740     } else {
2741       uint last_req = inp_cnt;
2742       if (is_vector_ternary_bitwise_op(n)) {
2743         last_req = inp_cnt - 1; // skip last input
2744       }
2745       for (uint i = 1; i < last_req; i++) {
2746         Node* def = n->in(i);
2747         if (!inputs.member(def)) {
2748           inputs.push(def);
2749           cnt++;
2750         }
2751       }
2752     }
2753   } else { // not a bitwise operations
2754     if (!inputs.member(n)) {
2755       inputs.push(n);
2756       cnt++;
2757     }
2758   }
2759   return cnt;
2760 }
2761 
2762 void Compile::collect_logic_cone_roots(Unique_Node_List& list) {
2763   Unique_Node_List useful_nodes;
2764   C->identify_useful_nodes(useful_nodes);
2765 
2766   for (uint i = 0; i < useful_nodes.size(); i++) {
2767     Node* n = useful_nodes.at(i);
2768     if (is_vector_bitwise_cone_root(n)) {
2769       list.push(n);
2770     }
2771   }
2772 }
2773 
2774 Node* Compile::xform_to_MacroLogicV(PhaseIterGVN& igvn,
2775                                     const TypeVect* vt,
2776                                     Unique_Node_List& partition,
2777                                     Unique_Node_List& inputs) {
2778   assert(partition.size() == 2 || partition.size() == 3, "not supported");
2779   assert(inputs.size()    == 2 || inputs.size()    == 3, "not supported");
2780   assert(Matcher::match_rule_supported_vector(Op_MacroLogicV, vt->length(), vt->element_basic_type()), "not supported");
2781 
2782   Node* in1 = inputs.at(0);
2783   Node* in2 = inputs.at(1);
2784   Node* in3 = (inputs.size() == 3 ? inputs.at(2) : in2);
2785 
2786   uint func = compute_truth_table(partition, inputs);
2787 
2788   Node* pn = partition.at(partition.size() - 1);
2789   Node* mask = pn->is_predicated_vector() ? pn->in(pn->req()-1) : nullptr;
2790   return igvn.transform(MacroLogicVNode::make(igvn, in1, in2, in3, mask, func, vt));
2791 }
2792 
2793 static uint extract_bit(uint func, uint pos) {
2794   return (func & (1 << pos)) >> pos;
2795 }
2796 
2797 //
2798 //  A macro logic node represents a truth table. It has 4 inputs,
2799 //  First three inputs corresponds to 3 columns of a truth table
2800 //  and fourth input captures the logic function.
2801 //
2802 //  eg.  fn = (in1 AND in2) OR in3;
2803 //
2804 //      MacroNode(in1,in2,in3,fn)
2805 //
2806 //  -----------------
2807 //  in1 in2 in3  fn
2808 //  -----------------
2809 //  0    0   0    0
2810 //  0    0   1    1
2811 //  0    1   0    0
2812 //  0    1   1    1
2813 //  1    0   0    0
2814 //  1    0   1    1
2815 //  1    1   0    1
2816 //  1    1   1    1
2817 //
2818 
2819 uint Compile::eval_macro_logic_op(uint func, uint in1 , uint in2, uint in3) {
2820   int res = 0;
2821   for (int i = 0; i < 8; i++) {
2822     int bit1 = extract_bit(in1, i);
2823     int bit2 = extract_bit(in2, i);
2824     int bit3 = extract_bit(in3, i);
2825 
2826     int func_bit_pos = (bit1 << 2 | bit2 << 1 | bit3);
2827     int func_bit = extract_bit(func, func_bit_pos);
2828 
2829     res |= func_bit << i;
2830   }
2831   return res;
2832 }
2833 
2834 static uint eval_operand(Node* n, HashTable<Node*,uint>& eval_map) {
2835   assert(n != nullptr, "");
2836   assert(eval_map.contains(n), "absent");
2837   return *(eval_map.get(n));
2838 }
2839 
2840 static void eval_operands(Node* n,
2841                           uint& func1, uint& func2, uint& func3,
2842                           HashTable<Node*,uint>& eval_map) {
2843   assert(is_vector_bitwise_op(n), "");
2844 
2845   if (is_vector_unary_bitwise_op(n)) {
2846     Node* opnd = n->in(1);
2847     if (VectorNode::is_vector_bitwise_not_pattern(n) && VectorNode::is_all_ones_vector(opnd)) {
2848       opnd = n->in(2);
2849     }
2850     func1 = eval_operand(opnd, eval_map);
2851   } else if (is_vector_binary_bitwise_op(n)) {
2852     func1 = eval_operand(n->in(1), eval_map);
2853     func2 = eval_operand(n->in(2), eval_map);
2854   } else {
2855     assert(is_vector_ternary_bitwise_op(n), "unknown operation");
2856     func1 = eval_operand(n->in(1), eval_map);
2857     func2 = eval_operand(n->in(2), eval_map);
2858     func3 = eval_operand(n->in(3), eval_map);
2859   }
2860 }
2861 
2862 uint Compile::compute_truth_table(Unique_Node_List& partition, Unique_Node_List& inputs) {
2863   assert(inputs.size() <= 3, "sanity");
2864   ResourceMark rm;
2865   uint res = 0;
2866   HashTable<Node*,uint> eval_map;
2867 
2868   // Populate precomputed functions for inputs.
2869   // Each input corresponds to one column of 3 input truth-table.
2870   uint input_funcs[] = { 0xAA,   // (_, _, c) -> c
2871                          0xCC,   // (_, b, _) -> b
2872                          0xF0 }; // (a, _, _) -> a
2873   for (uint i = 0; i < inputs.size(); i++) {
2874     eval_map.put(inputs.at(i), input_funcs[2-i]);
2875   }
2876 
2877   for (uint i = 0; i < partition.size(); i++) {
2878     Node* n = partition.at(i);
2879 
2880     uint func1 = 0, func2 = 0, func3 = 0;
2881     eval_operands(n, func1, func2, func3, eval_map);
2882 
2883     switch (n->Opcode()) {
2884       case Op_OrV:
2885         assert(func3 == 0, "not binary");
2886         res = func1 | func2;
2887         break;
2888       case Op_AndV:
2889         assert(func3 == 0, "not binary");
2890         res = func1 & func2;
2891         break;
2892       case Op_XorV:
2893         if (VectorNode::is_vector_bitwise_not_pattern(n)) {
2894           assert(func2 == 0 && func3 == 0, "not unary");
2895           res = (~func1) & 0xFF;
2896         } else {
2897           assert(func3 == 0, "not binary");
2898           res = func1 ^ func2;
2899         }
2900         break;
2901       case Op_MacroLogicV:
2902         // Ordering of inputs may change during evaluation of sub-tree
2903         // containing MacroLogic node as a child node, thus a re-evaluation
2904         // makes sure that function is evaluated in context of current
2905         // inputs.
2906         res = eval_macro_logic_op(n->in(4)->get_int(), func1, func2, func3);
2907         break;
2908 
2909       default: assert(false, "not supported: %s", n->Name());
2910     }
2911     assert(res <= 0xFF, "invalid");
2912     eval_map.put(n, res);
2913   }
2914   return res;
2915 }
2916 
2917 // Criteria under which nodes gets packed into a macro logic node:-
2918 //  1) Parent and both child nodes are all unmasked or masked with
2919 //     same predicates.
2920 //  2) Masked parent can be packed with left child if it is predicated
2921 //     and both have same predicates.
2922 //  3) Masked parent can be packed with right child if its un-predicated
2923 //     or has matching predication condition.
2924 //  4) An unmasked parent can be packed with an unmasked child.
2925 bool Compile::compute_logic_cone(Node* n, Unique_Node_List& partition, Unique_Node_List& inputs) {
2926   assert(partition.size() == 0, "not empty");
2927   assert(inputs.size() == 0, "not empty");
2928   if (is_vector_ternary_bitwise_op(n)) {
2929     return false;
2930   }
2931 
2932   bool is_unary_op = is_vector_unary_bitwise_op(n);
2933   if (is_unary_op) {
2934     assert(collect_unique_inputs(n, inputs) == 1, "not unary");
2935     return false; // too few inputs
2936   }
2937 
2938   bool pack_left_child = true;
2939   bool pack_right_child = true;
2940 
2941   bool left_child_LOP = is_vector_bitwise_op(n->in(1));
2942   bool right_child_LOP = is_vector_bitwise_op(n->in(2));
2943 
2944   int left_child_input_cnt = 0;
2945   int right_child_input_cnt = 0;
2946 
2947   bool parent_is_predicated = n->is_predicated_vector();
2948   bool left_child_predicated = n->in(1)->is_predicated_vector();
2949   bool right_child_predicated = n->in(2)->is_predicated_vector();
2950 
2951   Node* parent_pred = parent_is_predicated ? n->in(n->req()-1) : nullptr;
2952   Node* left_child_pred = left_child_predicated ? n->in(1)->in(n->in(1)->req()-1) : nullptr;
2953   Node* right_child_pred = right_child_predicated ? n->in(1)->in(n->in(1)->req()-1) : nullptr;
2954 
2955   do {
2956     if (pack_left_child && left_child_LOP &&
2957         ((!parent_is_predicated && !left_child_predicated) ||
2958         ((parent_is_predicated && left_child_predicated &&
2959           parent_pred == left_child_pred)))) {
2960        partition.push(n->in(1));
2961        left_child_input_cnt = collect_unique_inputs(n->in(1), inputs);
2962     } else {
2963        inputs.push(n->in(1));
2964        left_child_input_cnt = 1;
2965     }
2966 
2967     if (pack_right_child && right_child_LOP &&
2968         (!right_child_predicated ||
2969          (right_child_predicated && parent_is_predicated &&
2970           parent_pred == right_child_pred))) {
2971        partition.push(n->in(2));
2972        right_child_input_cnt = collect_unique_inputs(n->in(2), inputs);
2973     } else {
2974        inputs.push(n->in(2));
2975        right_child_input_cnt = 1;
2976     }
2977 
2978     if (inputs.size() > 3) {
2979       assert(partition.size() > 0, "");
2980       inputs.clear();
2981       partition.clear();
2982       if (left_child_input_cnt > right_child_input_cnt) {
2983         pack_left_child = false;
2984       } else {
2985         pack_right_child = false;
2986       }
2987     } else {
2988       break;
2989     }
2990   } while(true);
2991 
2992   if(partition.size()) {
2993     partition.push(n);
2994   }
2995 
2996   return (partition.size() == 2 || partition.size() == 3) &&
2997          (inputs.size()    == 2 || inputs.size()    == 3);
2998 }
2999 
3000 void Compile::process_logic_cone_root(PhaseIterGVN &igvn, Node *n, VectorSet &visited) {
3001   assert(is_vector_bitwise_op(n), "not a root");
3002 
3003   visited.set(n->_idx);
3004 
3005   // 1) Do a DFS walk over the logic cone.
3006   for (uint i = 1; i < n->req(); i++) {
3007     Node* in = n->in(i);
3008     if (!visited.test(in->_idx) && is_vector_bitwise_op(in)) {
3009       process_logic_cone_root(igvn, in, visited);
3010     }
3011   }
3012 
3013   // 2) Bottom up traversal: Merge node[s] with
3014   // the parent to form macro logic node.
3015   Unique_Node_List partition;
3016   Unique_Node_List inputs;
3017   if (compute_logic_cone(n, partition, inputs)) {
3018     const TypeVect* vt = n->bottom_type()->is_vect();
3019     Node* pn = partition.at(partition.size() - 1);
3020     Node* mask = pn->is_predicated_vector() ? pn->in(pn->req()-1) : nullptr;
3021     if (mask == nullptr ||
3022         Matcher::match_rule_supported_vector_masked(Op_MacroLogicV, vt->length(), vt->element_basic_type())) {
3023       Node* macro_logic = xform_to_MacroLogicV(igvn, vt, partition, inputs);
3024       VectorNode::trace_new_vector(macro_logic, "MacroLogic");
3025       igvn.replace_node(n, macro_logic);
3026     }
3027   }
3028 }
3029 
3030 void Compile::optimize_logic_cones(PhaseIterGVN &igvn) {
3031   ResourceMark rm;
3032   if (Matcher::match_rule_supported(Op_MacroLogicV)) {
3033     Unique_Node_List list;
3034     collect_logic_cone_roots(list);
3035 
3036     while (list.size() > 0) {
3037       Node* n = list.pop();
3038       const TypeVect* vt = n->bottom_type()->is_vect();
3039       bool supported = Matcher::match_rule_supported_vector(Op_MacroLogicV, vt->length(), vt->element_basic_type());
3040       if (supported) {
3041         VectorSet visited(comp_arena());
3042         process_logic_cone_root(igvn, n, visited);
3043       }
3044     }
3045   }
3046 }
3047 
3048 //------------------------------Code_Gen---------------------------------------
3049 // Given a graph, generate code for it
3050 void Compile::Code_Gen() {
3051   if (failing()) {
3052     return;
3053   }
3054 
3055   // Perform instruction selection.  You might think we could reclaim Matcher
3056   // memory PDQ, but actually the Matcher is used in generating spill code.
3057   // Internals of the Matcher (including some VectorSets) must remain live
3058   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
3059   // set a bit in reclaimed memory.
3060 
3061   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
3062   // nodes.  Mapping is only valid at the root of each matched subtree.
3063   NOT_PRODUCT( verify_graph_edges(); )
3064 
3065   Matcher matcher;
3066   _matcher = &matcher;
3067   {
3068     TracePhase tp(_t_matcher);
3069     matcher.match();
3070     if (failing()) {
3071       return;
3072     }
3073   }
3074   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
3075   // nodes.  Mapping is only valid at the root of each matched subtree.
3076   NOT_PRODUCT( verify_graph_edges(); )
3077 
3078   // If you have too many nodes, or if matching has failed, bail out
3079   check_node_count(0, "out of nodes matching instructions");
3080   if (failing()) {
3081     return;
3082   }
3083 
3084   print_method(PHASE_MATCHING, 2);
3085 
3086   // Build a proper-looking CFG
3087   PhaseCFG cfg(node_arena(), root(), matcher);
3088   if (failing()) {
3089     return;
3090   }
3091   _cfg = &cfg;
3092   {
3093     TracePhase tp(_t_scheduler);
3094     bool success = cfg.do_global_code_motion();
3095     if (!success) {
3096       return;
3097     }
3098 
3099     print_method(PHASE_GLOBAL_CODE_MOTION, 2);
3100     NOT_PRODUCT( verify_graph_edges(); )
3101     cfg.verify();
3102     if (failing()) {
3103       return;
3104     }
3105   }
3106 
3107   PhaseChaitin regalloc(unique(), cfg, matcher, false);
3108   _regalloc = &regalloc;
3109   {
3110     TracePhase tp(_t_registerAllocation);
3111     // Perform register allocation.  After Chaitin, use-def chains are
3112     // no longer accurate (at spill code) and so must be ignored.
3113     // Node->LRG->reg mappings are still accurate.
3114     _regalloc->Register_Allocate();
3115 
3116     // Bail out if the allocator builds too many nodes
3117     if (failing()) {
3118       return;
3119     }
3120 
3121     print_method(PHASE_REGISTER_ALLOCATION, 2);
3122   }
3123 
3124   // Prior to register allocation we kept empty basic blocks in case the
3125   // the allocator needed a place to spill.  After register allocation we
3126   // are not adding any new instructions.  If any basic block is empty, we
3127   // can now safely remove it.
3128   {
3129     TracePhase tp(_t_blockOrdering);
3130     cfg.remove_empty_blocks();
3131     if (do_freq_based_layout()) {
3132       PhaseBlockLayout layout(cfg);
3133     } else {
3134       cfg.set_loop_alignment();
3135     }
3136     cfg.fixup_flow();
3137     cfg.remove_unreachable_blocks();
3138     cfg.verify_dominator_tree();
3139     print_method(PHASE_BLOCK_ORDERING, 3);
3140   }
3141 
3142   // Apply peephole optimizations
3143   if( OptoPeephole ) {
3144     TracePhase tp(_t_peephole);
3145     PhasePeephole peep( _regalloc, cfg);
3146     peep.do_transform();
3147     print_method(PHASE_PEEPHOLE, 3);
3148   }
3149 
3150   // Do late expand if CPU requires this.
3151   if (Matcher::require_postalloc_expand) {
3152     TracePhase tp(_t_postalloc_expand);
3153     cfg.postalloc_expand(_regalloc);
3154     print_method(PHASE_POSTALLOC_EXPAND, 3);
3155   }
3156 
3157 #ifdef ASSERT
3158   {
3159     CompilationMemoryStatistic::do_test_allocations();
3160     if (failing()) return;
3161   }
3162 #endif
3163 
3164   // Convert Nodes to instruction bits in a buffer
3165   {
3166     TracePhase tp(_t_output);
3167     PhaseOutput output;
3168     output.Output();
3169     if (failing())  return;
3170     output.install();
3171     print_method(PHASE_FINAL_CODE, 1); // Compile::_output is not null here
3172   }
3173 
3174   // He's dead, Jim.
3175   _cfg     = (PhaseCFG*)((intptr_t)0xdeadbeef);
3176   _regalloc = (PhaseChaitin*)((intptr_t)0xdeadbeef);
3177 }
3178 
3179 //------------------------------Final_Reshape_Counts---------------------------
3180 // This class defines counters and node lists collected during
3181 // the final graph reshaping.
3182 struct Final_Reshape_Counts : public StackObj {
3183   int  _java_call_count;        // count non-inlined 'java' calls
3184   int  _inner_loop_count;       // count loops which need alignment
3185   VectorSet _visited;           // Visitation flags
3186   Node_List _tests;             // Set of IfNodes & PCTableNodes
3187 
3188   Final_Reshape_Counts() :
3189     _java_call_count(0), _inner_loop_count(0) { }
3190 
3191   void inc_java_call_count() { _java_call_count++; }
3192   void inc_inner_loop_count() { _inner_loop_count++; }
3193 
3194   int  get_java_call_count() const { return _java_call_count; }
3195   int  get_inner_loop_count() const { return _inner_loop_count; }
3196 };
3197 
3198 //------------------------------final_graph_reshaping_impl----------------------
3199 // Implement items 1-5 from final_graph_reshaping below.
3200 void Compile::final_graph_reshaping_impl(Node *n, Final_Reshape_Counts& frc, Unique_Node_List& dead_nodes) {
3201 
3202   if ( n->outcnt() == 0 ) return; // dead node
3203   uint nop = n->Opcode();
3204 
3205   // Check for 2-input instruction with "last use" on right input.
3206   // Swap to left input.  Implements item (2).
3207   if( n->req() == 3 &&          // two-input instruction
3208       n->in(1)->outcnt() > 1 && // left use is NOT a last use
3209       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
3210       n->in(2)->outcnt() == 1 &&// right use IS a last use
3211       !n->in(2)->is_Con() ) {   // right use is not a constant
3212     // Check for commutative opcode
3213     switch( nop ) {
3214     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddHF:  case Op_AddL:
3215     case Op_MaxI:  case Op_MaxL:  case Op_MaxF:  case Op_MaxD:
3216     case Op_MinI:  case Op_MinL:  case Op_MinF:  case Op_MinD:
3217     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulHF:  case Op_MulL:
3218     case Op_AndL:  case Op_XorL:  case Op_OrL:
3219     case Op_AndI:  case Op_XorI:  case Op_OrI: {
3220       // Move "last use" input to left by swapping inputs
3221       n->swap_edges(1, 2);
3222       break;
3223     }
3224     default:
3225       break;
3226     }
3227   }
3228 
3229 #ifdef ASSERT
3230   if( n->is_Mem() ) {
3231     int alias_idx = get_alias_index(n->as_Mem()->adr_type());
3232     assert( n->in(0) != nullptr || alias_idx != Compile::AliasIdxRaw ||
3233             // oop will be recorded in oop map if load crosses safepoint
3234             (n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
3235                               LoadNode::is_immutable_value(n->in(MemNode::Address)))),
3236             "raw memory operations should have control edge");
3237   }
3238   if (n->is_MemBar()) {
3239     MemBarNode* mb = n->as_MemBar();
3240     if (mb->trailing_store() || mb->trailing_load_store()) {
3241       assert(mb->leading_membar()->trailing_membar() == mb, "bad membar pair");
3242       Node* mem = BarrierSet::barrier_set()->barrier_set_c2()->step_over_gc_barrier(mb->in(MemBarNode::Precedent));
3243       assert((mb->trailing_store() && mem->is_Store() && mem->as_Store()->is_release()) ||
3244              (mb->trailing_load_store() && mem->is_LoadStore()), "missing mem op");
3245     } else if (mb->leading()) {
3246       assert(mb->trailing_membar()->leading_membar() == mb, "bad membar pair");
3247     }
3248   }
3249   if (n->is_CallLeafPure()) {
3250     // A pure call whose result projection is unused should have been
3251     // eliminated by CallLeafPureNode::Ideal during IGVN.
3252     assert(n->as_CallLeafPure()->proj_out_or_null(TypeFunc::Parms) != nullptr,
3253            "unused CallLeafPureNode should have been removed before final graph reshaping");
3254   }
3255 #endif
3256   bool gc_handled = BarrierSet::barrier_set()->barrier_set_c2()->final_graph_reshaping(this, n, nop, dead_nodes);
3257   if (!gc_handled) {
3258     final_graph_reshaping_main_switch(n, frc, nop, dead_nodes);
3259   }
3260 
3261   // Collect CFG split points
3262   if (n->is_MultiBranch() && !n->is_RangeCheck()) {
3263     frc._tests.push(n);
3264   }
3265 }
3266 
3267 void Compile::handle_div_mod_op(Node* n, BasicType bt, bool is_unsigned) {
3268   if (!UseDivMod) {
3269     return;
3270   }
3271 
3272   // Check if "a % b" and "a / b" both exist
3273   Node* d = n->find_similar(Op_DivIL(bt, is_unsigned));
3274   if (d == nullptr) {
3275     return;
3276   }
3277 
3278   // Replace them with a fused divmod if supported
3279   if (Matcher::has_match_rule(Op_DivModIL(bt, is_unsigned))) {
3280     DivModNode* divmod = DivModNode::make(n, bt, is_unsigned);
3281     // If the divisor input for a Div (or Mod etc.) is not zero, then the control input of the Div is set to zero.
3282     // It could be that the divisor input is found not zero because its type is narrowed down by a CastII in the
3283     // subgraph for that input. Range check CastIIs are removed during final graph reshape. To preserve the dependency
3284     // carried by a CastII, precedence edges are added to the Div node. We need to transfer the precedence edges to the
3285     // DivMod node so the dependency is not lost.
3286     divmod->add_prec_from(n);
3287     divmod->add_prec_from(d);
3288     d->subsume_by(divmod->first_proj(), this);
3289     n->subsume_by(divmod->second_proj(), this);
3290   } else {
3291     // Replace "a % b" with "a - ((a / b) * b)"
3292     Node* mult = MulNode::make(d, d->in(2), bt);
3293     Node* sub = SubNode::make(d->in(1), mult, bt);
3294     n->subsume_by(sub, this);
3295   }
3296 }
3297 
3298 void Compile::handle_mulhi_mul_op(Node* n, bool is_unsigned) {
3299   const int fused_opcode = is_unsigned ? Op_UMulHiLoL : Op_MulHiLoL;
3300   if (!Matcher::has_match_rule(fused_opcode)) {
3301     return;
3302   }
3303 
3304   Node* mul = n->find_similar(Op_MulL, true);
3305 
3306   if (mul == nullptr) {
3307     return;
3308   }
3309 
3310   MulHiLoLNode* mul_hi_lo = is_unsigned ? static_cast<MulHiLoLNode*>(UMulHiLoLNode::make(n))
3311                                         : MulHiLoLNode::make(n);
3312   mul->subsume_by(mul_hi_lo->first_proj(), this);
3313   n->subsume_by(mul_hi_lo->second_proj(), this);
3314 }
3315 
3316 void Compile::final_graph_reshaping_main_switch(Node* n, Final_Reshape_Counts& frc, uint nop, Unique_Node_List& dead_nodes) {
3317   switch( nop ) {
3318   case Op_Opaque1:              // Remove Opaque Nodes before matching
3319     n->subsume_by(n->in(1), this);
3320     break;
3321   case Op_CallLeafPure: {
3322     // If the pure call is not supported, then lower to a CallLeaf.
3323     if (!Matcher::match_rule_supported(Op_CallLeafPure)) {
3324       CallNode* call = n->as_Call();
3325       CallNode* new_call = new CallLeafNode(call->tf(), call->entry_point(),
3326                                             call->_name, TypeRawPtr::BOTTOM);
3327       new_call->init_req(TypeFunc::Control, call->in(TypeFunc::Control));
3328       new_call->init_req(TypeFunc::I_O, C->top());
3329       new_call->init_req(TypeFunc::Memory, C->top());
3330       new_call->init_req(TypeFunc::ReturnAdr, C->top());
3331       new_call->init_req(TypeFunc::FramePtr, C->top());
3332       for (unsigned int i = TypeFunc::Parms; i < call->tf()->domain()->cnt(); i++) {
3333         new_call->init_req(i, call->in(i));
3334       }
3335       n->subsume_by(new_call, this);
3336     }
3337     break;
3338   }
3339   case Op_CallStaticJava:
3340   case Op_CallJava:
3341   case Op_CallDynamicJava:
3342     frc.inc_java_call_count(); // Count java call site;
3343   case Op_CallRuntime:
3344   case Op_CallLeaf:
3345   case Op_CallLeafVector:
3346   case Op_CallLeafNoFP: {
3347     assert (n->is_Call(), "");
3348     CallNode *call = n->as_Call();
3349     // See if uncommon argument is shared
3350     if (call->is_CallStaticJava() && call->as_CallStaticJava()->_name) {
3351       Node *n = call->in(TypeFunc::Parms);
3352       int nop = n->Opcode();
3353       // Clone shared simple arguments to uncommon calls, item (1).
3354       if (n->outcnt() > 1 &&
3355           !n->is_Proj() &&
3356           nop != Op_CreateEx &&
3357           nop != Op_CheckCastPP &&
3358           nop != Op_DecodeN &&
3359           nop != Op_DecodeNKlass &&
3360           !n->is_Mem() &&
3361           !n->is_Phi()) {
3362         Node *x = n->clone();
3363         call->set_req(TypeFunc::Parms, x);
3364       }
3365     }
3366     break;
3367   }
3368 
3369   // Mem nodes need explicit cases to satisfy assert(!n->is_Mem()) in default.
3370   case Op_StoreF:
3371   case Op_LoadF:
3372   case Op_StoreD:
3373   case Op_LoadD:
3374   case Op_LoadD_unaligned:
3375   case Op_StoreB:
3376   case Op_StoreC:
3377   case Op_StoreI:
3378   case Op_StoreL:
3379   case Op_CompareAndSwapB:
3380   case Op_CompareAndSwapS:
3381   case Op_CompareAndSwapI:
3382   case Op_CompareAndSwapL:
3383   case Op_CompareAndSwapP:
3384   case Op_CompareAndSwapN:
3385   case Op_WeakCompareAndSwapB:
3386   case Op_WeakCompareAndSwapS:
3387   case Op_WeakCompareAndSwapI:
3388   case Op_WeakCompareAndSwapL:
3389   case Op_WeakCompareAndSwapP:
3390   case Op_WeakCompareAndSwapN:
3391   case Op_CompareAndExchangeB:
3392   case Op_CompareAndExchangeS:
3393   case Op_CompareAndExchangeI:
3394   case Op_CompareAndExchangeL:
3395   case Op_CompareAndExchangeP:
3396   case Op_CompareAndExchangeN:
3397   case Op_GetAndAddS:
3398   case Op_GetAndAddB:
3399   case Op_GetAndAddI:
3400   case Op_GetAndAddL:
3401   case Op_GetAndSetS:
3402   case Op_GetAndSetB:
3403   case Op_GetAndSetI:
3404   case Op_GetAndSetL:
3405   case Op_GetAndSetP:
3406   case Op_GetAndSetN:
3407   case Op_StoreP:
3408   case Op_StoreN:
3409   case Op_StoreNKlass:
3410   case Op_LoadB:
3411   case Op_LoadUB:
3412   case Op_LoadUS:
3413   case Op_LoadI:
3414   case Op_LoadKlass:
3415   case Op_LoadNKlass:
3416   case Op_LoadL:
3417   case Op_LoadL_unaligned:
3418   case Op_LoadP:
3419   case Op_LoadN:
3420   case Op_LoadRange:
3421   case Op_LoadS:
3422   case Op_LoadVectorGather:
3423   case Op_StoreVectorScatter:
3424   case Op_LoadVectorGatherMasked:
3425   case Op_StoreVectorScatterMasked:
3426   case Op_LoadVectorMasked:
3427   case Op_StoreVectorMasked:
3428     break;
3429 
3430   case Op_AddP: {               // Assert sane base pointers
3431     Node *addp = n->in(AddPNode::Address);
3432     assert(n->as_AddP()->address_input_has_same_base(), "Base pointers must match (addp %u)", addp->_idx );
3433 #ifdef _LP64
3434     if (addp->Opcode() == Op_ConP &&
3435         addp == n->in(AddPNode::Base) &&
3436         n->in(AddPNode::Offset)->is_Con()) {
3437       // If the transformation of ConP to ConN+DecodeN is beneficial depends
3438       // on the platform and on the compressed oops mode.
3439       // Use addressing with narrow klass to load with offset on x86.
3440       // Some platforms can use the constant pool to load ConP.
3441       // Do this transformation here since IGVN will convert ConN back to ConP.
3442       const Type* t = addp->bottom_type();
3443       bool is_oop   = t->isa_oopptr() != nullptr;
3444       bool is_klass = t->isa_klassptr() != nullptr;
3445 
3446       if ((is_oop   && UseCompressedOops          && Matcher::const_oop_prefer_decode()  ) ||
3447           (is_klass && Matcher::const_klass_prefer_decode() &&
3448            t->isa_klassptr()->exact_klass()->is_in_encoding_range())) {
3449         Node* nn = nullptr;
3450 
3451         int op = is_oop ? Op_ConN : Op_ConNKlass;
3452 
3453         // Look for existing ConN node of the same exact type.
3454         Node* r  = root();
3455         uint cnt = r->outcnt();
3456         for (uint i = 0; i < cnt; i++) {
3457           Node* m = r->raw_out(i);
3458           if (m!= nullptr && m->Opcode() == op &&
3459               m->bottom_type()->make_ptr() == t) {
3460             nn = m;
3461             break;
3462           }
3463         }
3464         if (nn != nullptr) {
3465           // Decode a narrow oop to match address
3466           // [R12 + narrow_oop_reg<<3 + offset]
3467           if (is_oop) {
3468             nn = new DecodeNNode(nn, t);
3469           } else {
3470             nn = new DecodeNKlassNode(nn, t);
3471           }
3472           // Check for succeeding AddP which uses the same Base.
3473           // Otherwise we will run into the assertion above when visiting that guy.
3474           for (uint i = 0; i < n->outcnt(); ++i) {
3475             Node *out_i = n->raw_out(i);
3476             if (out_i && out_i->is_AddP() && out_i->in(AddPNode::Base) == addp) {
3477               out_i->set_req(AddPNode::Base, nn);
3478 #ifdef ASSERT
3479               for (uint j = 0; j < out_i->outcnt(); ++j) {
3480                 Node *out_j = out_i->raw_out(j);
3481                 assert(out_j == nullptr || !out_j->is_AddP() || out_j->in(AddPNode::Base) != addp,
3482                        "more than 2 AddP nodes in a chain (out_j %u)", out_j->_idx);
3483               }
3484 #endif
3485             }
3486           }
3487           n->set_req(AddPNode::Base, nn);
3488           n->set_req(AddPNode::Address, nn);
3489           if (addp->outcnt() == 0) {
3490             addp->disconnect_inputs(this);
3491           }
3492         }
3493       }
3494     }
3495 #endif
3496     break;
3497   }
3498 
3499   case Op_CastPP: {
3500     // Remove CastPP nodes to gain more freedom during scheduling but
3501     // keep the dependency they encode as control or precedence edges
3502     // (if control is set already) on memory operations. Some CastPP
3503     // nodes don't have a control (don't carry a dependency): skip
3504     // those.
3505     if (n->in(0) != nullptr) {
3506       ResourceMark rm;
3507       Unique_Node_List wq;
3508       wq.push(n);
3509 
3510 
3511       // When we remove a CastPP, we need to pin all of its transitive users under the control of
3512       // the removed node. The simplest approach is to pin all of the uses of the removed CastPP,
3513       // but it is overly conservative, as an AddP does not really need pinning. As a result, we
3514       // look through those nodes that do not need pinning and only pin memory access nodes under
3515       // n->in(0).
3516       for (uint next = 0; next < wq.size(); ++next) {
3517         Node *m = wq.at(next);
3518         for (DUIterator_Fast imax, i = m->fast_outs(imax); i < imax; i++) {
3519           Node* use = m->fast_out(i);
3520           int use_op = use->Opcode();
3521           if (use->is_CFG() || use->pinned() ||                               // already pinned at the exact control
3522               use->is_Cmp() || use_op == Op_CastP2X || use_op == Op_Conv2B) { // pure computations
3523             continue;
3524           } else if (use->is_EncodeNarrowPtr() ||        // EncodeP remembers whether its input is nullable, so it must be pinned
3525                      use_op == Op_PartialSubtypeCheck || // This accesses its pointer inputs, so it must depend on them being not-null
3526                      use->is_Mem() || use->is_memory_access_intrinsic()) {
3527             use->ensure_control_or_add_prec(n->in(0));
3528           } else if (use_op == Op_AddP    ||
3529                      use_op == Op_CastPP  || use_op == Op_CheckCastPP  ||
3530                      use_op == Op_CMoveP  || use_op == Op_CMoveN       ||
3531                      use_op == Op_DecodeN || use_op == Op_DecodeNKlass ||
3532                      use_op == Op_VerifyVectorAlignment) {
3533             // Look through use to find memory accesses if use does not need pinning
3534             wq.push(use);
3535           } else {
3536             // Should have handled all kinds of nodes, verify that we do not unexpectedly arrive
3537             // here
3538             assert(false, "unexpected node %s", use->Name());
3539             // Be conservative in product and pin the unexpected use
3540             use->ensure_control_or_add_prec(n->in(0));
3541           }
3542         }
3543       }
3544     }
3545     const bool is_LP64 = LP64_ONLY(true) NOT_LP64(false);
3546     if (is_LP64 && n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
3547       Node* in1 = n->in(1);
3548       const Type* t = n->bottom_type();
3549       Node* new_in1 = in1->clone();
3550       new_in1->as_DecodeN()->set_type(t);
3551 
3552       if (!Matcher::narrow_oop_use_complex_address()) {
3553         //
3554         // x86, ARM and friends can handle 2 adds in addressing mode
3555         // and Matcher can fold a DecodeN node into address by using
3556         // a narrow oop directly and do implicit null check in address:
3557         //
3558         // [R12 + narrow_oop_reg<<3 + offset]
3559         // NullCheck narrow_oop_reg
3560         //
3561         // On other platforms (Sparc) we have to keep new DecodeN node and
3562         // use it to do implicit null check in address:
3563         //
3564         // decode_not_null narrow_oop_reg, base_reg
3565         // [base_reg + offset]
3566         // NullCheck base_reg
3567         //
3568         // Pin the new DecodeN node to non-null path on these platform (Sparc)
3569         // to keep the information to which null check the new DecodeN node
3570         // corresponds to use it as value in implicit_null_check().
3571         //
3572         new_in1->set_req(0, n->in(0));
3573       }
3574 
3575       n->subsume_by(new_in1, this);
3576       if (in1->outcnt() == 0) {
3577         in1->disconnect_inputs(this);
3578       }
3579     } else {
3580       n->subsume_by(n->in(1), this);
3581       if (n->outcnt() == 0) {
3582         n->disconnect_inputs(this);
3583       }
3584     }
3585     break;
3586   }
3587   case Op_CastII: {
3588     n->as_CastII()->remove_range_check_cast(this);
3589     break;
3590   }
3591 #ifdef _LP64
3592   case Op_CmpP:
3593     // Do this transformation here to preserve CmpPNode::sub() and
3594     // other TypePtr related Ideal optimizations (for example, ptr nullness).
3595     if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
3596       Node* in1 = n->in(1);
3597       Node* in2 = n->in(2);
3598       if (!in1->is_DecodeNarrowPtr()) {
3599         in2 = in1;
3600         in1 = n->in(2);
3601       }
3602       assert(in1->is_DecodeNarrowPtr(), "sanity");
3603 
3604       Node* new_in2 = nullptr;
3605       if (in2->is_DecodeNarrowPtr()) {
3606         assert(in2->Opcode() == in1->Opcode(), "must be same node type");
3607         new_in2 = in2->in(1);
3608       } else if (in2->Opcode() == Op_ConP) {
3609         const Type* t = in2->bottom_type();
3610         if (t == TypePtr::NULL_PTR) {
3611           assert(in1->is_DecodeN(), "compare klass to null?");
3612           // Don't convert CmpP null check into CmpN if compressed
3613           // oops implicit null check is not generated.
3614           // This will allow to generate normal oop implicit null check.
3615           if (Matcher::gen_narrow_oop_implicit_null_checks())
3616             new_in2 = ConNode::make(TypeNarrowOop::NULL_PTR);
3617           //
3618           // This transformation together with CastPP transformation above
3619           // will generated code for implicit null checks for compressed oops.
3620           //
3621           // The original code after Optimize()
3622           //
3623           //    LoadN memory, narrow_oop_reg
3624           //    decode narrow_oop_reg, base_reg
3625           //    CmpP base_reg, nullptr
3626           //    CastPP base_reg // NotNull
3627           //    Load [base_reg + offset], val_reg
3628           //
3629           // after these transformations will be
3630           //
3631           //    LoadN memory, narrow_oop_reg
3632           //    CmpN narrow_oop_reg, nullptr
3633           //    decode_not_null narrow_oop_reg, base_reg
3634           //    Load [base_reg + offset], val_reg
3635           //
3636           // and the uncommon path (== nullptr) will use narrow_oop_reg directly
3637           // since narrow oops can be used in debug info now (see the code in
3638           // final_graph_reshaping_walk()).
3639           //
3640           // At the end the code will be matched to
3641           // on x86:
3642           //
3643           //    Load_narrow_oop memory, narrow_oop_reg
3644           //    Load [R12 + narrow_oop_reg<<3 + offset], val_reg
3645           //    NullCheck narrow_oop_reg
3646           //
3647           // and on sparc:
3648           //
3649           //    Load_narrow_oop memory, narrow_oop_reg
3650           //    decode_not_null narrow_oop_reg, base_reg
3651           //    Load [base_reg + offset], val_reg
3652           //    NullCheck base_reg
3653           //
3654         } else if (t->isa_oopptr()) {
3655           new_in2 = ConNode::make(t->make_narrowoop());
3656         } else if (t->isa_klassptr()) {
3657           ciKlass* klass = t->is_klassptr()->exact_klass();
3658           if (klass->is_in_encoding_range()) {
3659             new_in2 = ConNode::make(t->make_narrowklass());
3660           }
3661         }
3662       }
3663       if (new_in2 != nullptr) {
3664         Node* cmpN = new CmpNNode(in1->in(1), new_in2);
3665         n->subsume_by(cmpN, this);
3666         if (in1->outcnt() == 0) {
3667           in1->disconnect_inputs(this);
3668         }
3669         if (in2->outcnt() == 0) {
3670           in2->disconnect_inputs(this);
3671         }
3672       }
3673     }
3674     break;
3675 
3676   case Op_DecodeN:
3677   case Op_DecodeNKlass:
3678     assert(!n->in(1)->is_EncodeNarrowPtr(), "should be optimized out");
3679     // DecodeN could be pinned when it can't be fold into
3680     // an address expression, see the code for Op_CastPP above.
3681     assert(n->in(0) == nullptr || (UseCompressedOops && !Matcher::narrow_oop_use_complex_address()), "no control");
3682     break;
3683 
3684   case Op_EncodeP:
3685   case Op_EncodePKlass: {
3686     Node* in1 = n->in(1);
3687     if (in1->is_DecodeNarrowPtr()) {
3688       n->subsume_by(in1->in(1), this);
3689     } else if (in1->Opcode() == Op_ConP) {
3690       const Type* t = in1->bottom_type();
3691       if (t == TypePtr::NULL_PTR) {
3692         assert(t->isa_oopptr(), "null klass?");
3693         n->subsume_by(ConNode::make(TypeNarrowOop::NULL_PTR), this);
3694       } else if (t->isa_oopptr()) {
3695         n->subsume_by(ConNode::make(t->make_narrowoop()), this);
3696       } else if (t->isa_klassptr()) {
3697         ciKlass* klass = t->is_klassptr()->exact_klass();
3698         if (klass->is_in_encoding_range()) {
3699           n->subsume_by(ConNode::make(t->make_narrowklass()), this);
3700         } else {
3701           assert(false, "unencodable klass in ConP -> EncodeP");
3702           C->record_failure("unencodable klass in ConP -> EncodeP");
3703         }
3704       }
3705     }
3706     if (in1->outcnt() == 0) {
3707       in1->disconnect_inputs(this);
3708     }
3709     break;
3710   }
3711 
3712   case Op_Proj: {
3713     if (OptimizeStringConcat || IncrementalInline) {
3714       ProjNode* proj = n->as_Proj();
3715       if (proj->_is_io_use) {
3716         assert(proj->_con == TypeFunc::I_O || proj->_con == TypeFunc::Memory, "");
3717         // Separate projections were used for the exception path which
3718         // are normally removed by a late inline.  If it wasn't inlined
3719         // then they will hang around and should just be replaced with
3720         // the original one. Merge them.
3721         Node* non_io_proj = proj->in(0)->as_Multi()->proj_out_or_null(proj->_con, false /*is_io_use*/);
3722         if (non_io_proj  != nullptr) {
3723           proj->subsume_by(non_io_proj , this);
3724         }
3725       }
3726     }
3727     break;
3728   }
3729 
3730   case Op_Phi:
3731     if (n->as_Phi()->bottom_type()->isa_narrowoop() || n->as_Phi()->bottom_type()->isa_narrowklass()) {
3732       // The EncodeP optimization may create Phi with the same edges
3733       // for all paths. It is not handled well by Register Allocator.
3734       Node* unique_in = n->in(1);
3735       assert(unique_in != nullptr, "");
3736       uint cnt = n->req();
3737       for (uint i = 2; i < cnt; i++) {
3738         Node* m = n->in(i);
3739         assert(m != nullptr, "");
3740         if (unique_in != m)
3741           unique_in = nullptr;
3742       }
3743       if (unique_in != nullptr) {
3744         n->subsume_by(unique_in, this);
3745       }
3746     }
3747     break;
3748 
3749 #endif
3750 
3751   case Op_ModI:
3752     handle_div_mod_op(n, T_INT, false);
3753     break;
3754 
3755   case Op_ModL:
3756     handle_div_mod_op(n, T_LONG, false);
3757     break;
3758 
3759   case Op_UModI:
3760     handle_div_mod_op(n, T_INT, true);
3761     break;
3762 
3763   case Op_UModL:
3764     handle_div_mod_op(n, T_LONG, true);
3765     break;
3766 
3767   case Op_MulHiL:
3768     handle_mulhi_mul_op(n, false);
3769     break;
3770 
3771   case Op_UMulHiL:
3772     handle_mulhi_mul_op(n, true);
3773     break;
3774 
3775   case Op_LoadVector:
3776   case Op_StoreVector:
3777 #ifdef ASSERT
3778     // Add VerifyVectorAlignment node between adr and load / store.
3779     if (VerifyAlignVector && Matcher::has_match_rule(Op_VerifyVectorAlignment)) {
3780       bool must_verify_alignment = n->is_LoadVector() ? n->as_LoadVector()->must_verify_alignment() :
3781                                                         n->as_StoreVector()->must_verify_alignment();
3782       if (must_verify_alignment) {
3783         jlong vector_width = n->is_LoadVector() ? n->as_LoadVector()->memory_size() :
3784                                                   n->as_StoreVector()->memory_size();
3785         // The memory access should be aligned to the vector width in bytes.
3786         // However, the underlying array is possibly less well aligned, but at least
3787         // to ObjectAlignmentInBytes. Hence, even if multiple arrays are accessed in
3788         // a loop we can expect at least the following alignment:
3789         jlong guaranteed_alignment = MIN2(vector_width, (jlong)ObjectAlignmentInBytes);
3790         assert(2 <= guaranteed_alignment && guaranteed_alignment <= 64, "alignment must be in range");
3791         assert(is_power_of_2(guaranteed_alignment), "alignment must be power of 2");
3792         // Create mask from alignment. e.g. 0b1000 -> 0b0111
3793         jlong mask = guaranteed_alignment - 1;
3794         Node* mask_con = ConLNode::make(mask);
3795         VerifyVectorAlignmentNode* va = new VerifyVectorAlignmentNode(n->in(MemNode::Address), mask_con);
3796         n->set_req(MemNode::Address, va);
3797       }
3798     }
3799 #endif
3800     break;
3801 
3802   case Op_PackB:
3803   case Op_PackS:
3804   case Op_PackI:
3805   case Op_PackF:
3806   case Op_PackL:
3807   case Op_PackD:
3808     if (n->req()-1 > 2) {
3809       // Replace many operand PackNodes with a binary tree for matching
3810       PackNode* p = (PackNode*) n;
3811       Node* btp = p->binary_tree_pack(1, n->req());
3812       n->subsume_by(btp, this);
3813     }
3814     break;
3815   case Op_Loop:
3816     // When StressCountedLoop is enabled, this loop may intentionally avoid a counted loop conversion.
3817     // This is expected behavior for the stress mode, which exercises alternative compilation paths.
3818     if (!StressCountedLoop) {
3819       assert(!n->as_Loop()->is_loop_nest_inner_loop() || _loop_opts_cnt == 0, "should have been turned into a counted loop");
3820     }
3821   case Op_CountedLoop:
3822   case Op_LongCountedLoop:
3823   case Op_OuterStripMinedLoop:
3824     if (n->as_Loop()->is_inner_loop()) {
3825       frc.inc_inner_loop_count();
3826     }
3827     n->as_Loop()->verify_strip_mined(0);
3828     break;
3829   case Op_LShiftI:
3830   case Op_RShiftI:
3831   case Op_URShiftI:
3832   case Op_LShiftL:
3833   case Op_RShiftL:
3834   case Op_URShiftL:
3835     if (Matcher::need_masked_shift_count) {
3836       // The cpu's shift instructions don't restrict the count to the
3837       // lower 5/6 bits. We need to do the masking ourselves.
3838       Node* in2 = n->in(2);
3839       juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
3840       const TypeInt* t = in2->find_int_type();
3841       if (t != nullptr && t->is_con()) {
3842         juint shift = t->get_con();
3843         if (shift > mask) { // Unsigned cmp
3844           n->set_req(2, ConNode::make(TypeInt::make(shift & mask)));
3845         }
3846       } else {
3847         if (t == nullptr || t->_lo < 0 || t->_hi > (int)mask) {
3848           Node* shift = new AndINode(in2, ConNode::make(TypeInt::make(mask)));
3849           n->set_req(2, shift);
3850         }
3851       }
3852       if (in2->outcnt() == 0) { // Remove dead node
3853         in2->disconnect_inputs(this);
3854       }
3855     }
3856     break;
3857   case Op_MemBarStoreStore:
3858   case Op_MemBarRelease:
3859     // Break the link with AllocateNode: it is no longer useful and
3860     // confuses register allocation.
3861     if (n->req() > MemBarNode::Precedent) {
3862       n->set_req(MemBarNode::Precedent, top());
3863     }
3864     break;
3865   case Op_MemBarAcquire: {
3866     if (n->as_MemBar()->trailing_load() && n->req() > MemBarNode::Precedent) {
3867       // At parse time, the trailing MemBarAcquire for a volatile load
3868       // is created with an edge to the load. After optimizations,
3869       // that input may be a chain of Phis. If those phis have no
3870       // other use, then the MemBarAcquire keeps them alive and
3871       // register allocation can be confused.
3872       dead_nodes.push(n->in(MemBarNode::Precedent));
3873       n->set_req(MemBarNode::Precedent, top());
3874     }
3875     break;
3876   }
3877   case Op_RangeCheck: {
3878     RangeCheckNode* rc = n->as_RangeCheck();
3879     Node* iff = new IfNode(rc->in(0), rc->in(1), rc->_prob, rc->_fcnt);
3880     n->subsume_by(iff, this);
3881     frc._tests.push(iff);
3882     break;
3883   }
3884   case Op_ConvI2L: {
3885     if (!Matcher::convi2l_type_required) {
3886       // Code generation on some platforms doesn't need accurate
3887       // ConvI2L types. Widening the type can help remove redundant
3888       // address computations.
3889       n->as_Type()->set_type(TypeLong::INT);
3890       ResourceMark rm;
3891       Unique_Node_List wq;
3892       wq.push(n);
3893       for (uint next = 0; next < wq.size(); next++) {
3894         Node *m = wq.at(next);
3895 
3896         for(;;) {
3897           // Loop over all nodes with identical inputs edges as m
3898           Node* k = m->find_similar(m->Opcode());
3899           if (k == nullptr) {
3900             break;
3901           }
3902           // Push their uses so we get a chance to remove node made
3903           // redundant
3904           for (DUIterator_Fast imax, i = k->fast_outs(imax); i < imax; i++) {
3905             Node* u = k->fast_out(i);
3906             if (u->Opcode() == Op_LShiftL ||
3907                 u->Opcode() == Op_AddL ||
3908                 u->Opcode() == Op_SubL ||
3909                 u->Opcode() == Op_AddP) {
3910               wq.push(u);
3911             }
3912           }
3913           // Replace all nodes with identical edges as m with m
3914           k->subsume_by(m, this);
3915         }
3916       }
3917     }
3918     break;
3919   }
3920   case Op_CmpUL: {
3921     if (!Matcher::has_match_rule(Op_CmpUL)) {
3922       // No support for unsigned long comparisons
3923       ConINode* sign_pos = new ConINode(TypeInt::make(BitsPerLong - 1));
3924       Node* sign_bit_mask = new RShiftLNode(n->in(1), sign_pos);
3925       Node* orl = new OrLNode(n->in(1), sign_bit_mask);
3926       ConLNode* remove_sign_mask = new ConLNode(TypeLong::make(max_jlong));
3927       Node* andl = new AndLNode(orl, remove_sign_mask);
3928       Node* cmp = new CmpLNode(andl, n->in(2));
3929       n->subsume_by(cmp, this);
3930     }
3931     break;
3932   }
3933 #ifdef ASSERT
3934   case Op_ConNKlass: {
3935     const TypePtr* tp = n->as_Type()->type()->make_ptr();
3936     ciKlass* klass = tp->is_klassptr()->exact_klass();
3937     assert(klass->is_in_encoding_range(), "klass cannot be compressed");
3938     break;
3939   }
3940 #endif
3941   default:
3942     assert(!n->is_Call(), "");
3943     assert(!n->is_Mem(), "");
3944     assert(nop != Op_ProfileBoolean, "should be eliminated during IGVN");
3945     break;
3946   }
3947 }
3948 
3949 //------------------------------final_graph_reshaping_walk---------------------
3950 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
3951 // requires that the walk visits a node's inputs before visiting the node.
3952 void Compile::final_graph_reshaping_walk(Node_Stack& nstack, Node* root, Final_Reshape_Counts& frc, Unique_Node_List& dead_nodes) {
3953   Unique_Node_List sfpt;
3954 
3955   frc._visited.set(root->_idx); // first, mark node as visited
3956   uint cnt = root->req();
3957   Node *n = root;
3958   uint  i = 0;
3959   while (true) {
3960     if (i < cnt) {
3961       // Place all non-visited non-null inputs onto stack
3962       Node* m = n->in(i);
3963       ++i;
3964       if (m != nullptr && !frc._visited.test_set(m->_idx)) {
3965         if (m->is_SafePoint() && m->as_SafePoint()->jvms() != nullptr) {
3966           // compute worst case interpreter size in case of a deoptimization
3967           update_interpreter_frame_size(m->as_SafePoint()->jvms()->interpreter_frame_size());
3968 
3969           sfpt.push(m);
3970         }
3971         cnt = m->req();
3972         nstack.push(n, i); // put on stack parent and next input's index
3973         n = m;
3974         i = 0;
3975       }
3976     } else {
3977       // Now do post-visit work
3978       final_graph_reshaping_impl(n, frc, dead_nodes);
3979       if (nstack.is_empty())
3980         break;             // finished
3981       n = nstack.node();   // Get node from stack
3982       cnt = n->req();
3983       i = nstack.index();
3984       nstack.pop();        // Shift to the next node on stack
3985     }
3986   }
3987 
3988   expand_reachability_edges(sfpt);
3989 
3990   // Skip next transformation if compressed oops are not used.
3991   if (UseCompressedOops && !Matcher::gen_narrow_oop_implicit_null_checks())
3992     return;
3993 
3994   // Go over ReachabilityFence nodes to skip DecodeN nodes for referents.
3995   // The sole purpose of RF node is to keep the referent oop alive and
3996   // decoding the oop for that is not needed.
3997   for (int i = 0; i < C->reachability_fences_count(); i++) {
3998     ReachabilityFenceNode* rf = C->reachability_fence(i);
3999     DecodeNNode* dn = rf->in(1)->isa_DecodeN();
4000     if (dn != nullptr) {
4001       if (!dn->has_non_debug_uses() || Matcher::narrow_oop_use_complex_address()) {
4002         rf->set_req(1, dn->in(1));
4003         if (dn->outcnt() == 0) {
4004           dn->disconnect_inputs(this);
4005         }
4006       }
4007     }
4008   }
4009 
4010   // Go over safepoints nodes to skip DecodeN/DecodeNKlass nodes for debug edges.
4011   // It could be done for an uncommon traps or any safepoints/calls
4012   // if the DecodeN/DecodeNKlass node is referenced only in a debug info.
4013   while (sfpt.size() > 0) {
4014     n = sfpt.pop();
4015     JVMState *jvms = n->as_SafePoint()->jvms();
4016     assert(jvms != nullptr, "sanity");
4017     int start = jvms->debug_start();
4018     int end   = n->req();
4019     bool is_uncommon = (n->is_CallStaticJava() &&
4020                         n->as_CallStaticJava()->uncommon_trap_request() != 0);
4021     for (int j = start; j < end; j++) {
4022       Node* in = n->in(j);
4023       if (in->is_DecodeNarrowPtr() && (is_uncommon || !in->has_non_debug_uses())) {
4024         n->set_req(j, in->in(1));
4025         if (in->outcnt() == 0) {
4026           in->disconnect_inputs(this);
4027         }
4028       }
4029     }
4030   }
4031 }
4032 
4033 //------------------------------final_graph_reshaping--------------------------
4034 // Final Graph Reshaping.
4035 //
4036 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
4037 //     and not commoned up and forced early.  Must come after regular
4038 //     optimizations to avoid GVN undoing the cloning.  Clone constant
4039 //     inputs to Loop Phis; these will be split by the allocator anyways.
4040 //     Remove Opaque nodes.
4041 // (2) Move last-uses by commutative operations to the left input to encourage
4042 //     Intel update-in-place two-address operations and better register usage
4043 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
4044 //     calls canonicalizing them back.
4045 // (3) Detect infinite loops; blobs of code reachable from above but not
4046 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
4047 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
4048 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
4049 //     Detection is by looking for IfNodes where only 1 projection is
4050 //     reachable from below or CatchNodes missing some targets.
4051 // (4) Assert for insane oop offsets in debug mode.
4052 
4053 bool Compile::final_graph_reshaping() {
4054   // an infinite loop may have been eliminated by the optimizer,
4055   // in which case the graph will be empty.
4056   if (root()->req() == 1) {
4057     // Do not compile method that is only a trivial infinite loop,
4058     // since the content of the loop may have been eliminated.
4059     record_method_not_compilable("trivial infinite loop");
4060     return true;
4061   }
4062 
4063   // Expensive nodes have their control input set to prevent the GVN
4064   // from freely commoning them. There's no GVN beyond this point so
4065   // no need to keep the control input. We want the expensive nodes to
4066   // be freely moved to the least frequent code path by gcm.
4067   assert(OptimizeExpensiveOps || expensive_count() == 0, "optimization off but list non empty?");
4068   for (int i = 0; i < expensive_count(); i++) {
4069     _expensive_nodes.at(i)->set_req(0, nullptr);
4070   }
4071 
4072   Final_Reshape_Counts frc;
4073 
4074   // Visit everybody reachable!
4075   // Allocate stack of size C->live_nodes()/2 to avoid frequent realloc
4076   Node_Stack nstack(live_nodes() >> 1);
4077   Unique_Node_List dead_nodes;
4078   final_graph_reshaping_walk(nstack, root(), frc, dead_nodes);
4079 
4080   // Check for unreachable (from below) code (i.e., infinite loops).
4081   for( uint i = 0; i < frc._tests.size(); i++ ) {
4082     MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
4083     // Get number of CFG targets.
4084     // Note that PCTables include exception targets after calls.
4085     uint required_outcnt = n->required_outcnt();
4086     if (n->outcnt() != required_outcnt) {
4087       // Check for a few special cases.  Rethrow Nodes never take the
4088       // 'fall-thru' path, so expected kids is 1 less.
4089       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
4090         if (n->in(0)->in(0)->is_Call()) {
4091           CallNode* call = n->in(0)->in(0)->as_Call();
4092           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
4093             required_outcnt--;      // Rethrow always has 1 less kid
4094           } else if (call->req() > TypeFunc::Parms &&
4095                      call->is_CallDynamicJava()) {
4096             // Check for null receiver. In such case, the optimizer has
4097             // detected that the virtual call will always result in a null
4098             // pointer exception. The fall-through projection of this CatchNode
4099             // will not be populated.
4100             Node* arg0 = call->in(TypeFunc::Parms);
4101             if (arg0->is_Type() &&
4102                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
4103               required_outcnt--;
4104             }
4105           } else if (call->entry_point() == OptoRuntime::new_array_Java() ||
4106                      call->entry_point() == OptoRuntime::new_array_nozero_Java()) {
4107             // Check for illegal array length. In such case, the optimizer has
4108             // detected that the allocation attempt will always result in an
4109             // exception. There is no fall-through projection of this CatchNode .
4110             assert(call->is_CallStaticJava(), "static call expected");
4111             assert(call->req() == call->jvms()->endoff() + 1, "missing extra input");
4112             uint valid_length_test_input = call->req() - 1;
4113             Node* valid_length_test = call->in(valid_length_test_input);
4114             call->del_req(valid_length_test_input);
4115             if (valid_length_test->find_int_con(1) == 0) {
4116               required_outcnt--;
4117             }
4118             dead_nodes.push(valid_length_test);
4119             assert(n->outcnt() == required_outcnt, "malformed control flow");
4120             continue;
4121           }
4122         }
4123       }
4124 
4125       // Recheck with a better notion of 'required_outcnt'
4126       if (n->outcnt() != required_outcnt) {
4127         record_method_not_compilable("malformed control flow");
4128         return true;            // Not all targets reachable!
4129       }
4130     } else if (n->is_PCTable() && n->in(0) && n->in(0)->in(0) && n->in(0)->in(0)->is_Call()) {
4131       CallNode* call = n->in(0)->in(0)->as_Call();
4132       if (call->entry_point() == OptoRuntime::new_array_Java() ||
4133           call->entry_point() == OptoRuntime::new_array_nozero_Java()) {
4134         assert(call->is_CallStaticJava(), "static call expected");
4135         assert(call->req() == call->jvms()->endoff() + 1, "missing extra input");
4136         uint valid_length_test_input = call->req() - 1;
4137         dead_nodes.push(call->in(valid_length_test_input));
4138         call->del_req(valid_length_test_input); // valid length test useless now
4139       }
4140     }
4141     // Check that I actually visited all kids.  Unreached kids
4142     // must be infinite loops.
4143     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
4144       if (!frc._visited.test(n->fast_out(j)->_idx)) {
4145         record_method_not_compilable("infinite loop");
4146         return true;            // Found unvisited kid; must be unreach
4147       }
4148 
4149     // Here so verification code in final_graph_reshaping_walk()
4150     // always see an OuterStripMinedLoopEnd
4151     if (n->is_OuterStripMinedLoopEnd() || n->is_LongCountedLoopEnd()) {
4152       IfNode* init_iff = n->as_If();
4153       Node* iff = new IfNode(init_iff->in(0), init_iff->in(1), init_iff->_prob, init_iff->_fcnt);
4154       n->subsume_by(iff, this);
4155     }
4156   }
4157 
4158   while (dead_nodes.size() > 0) {
4159     Node* m = dead_nodes.pop();
4160     if (m->outcnt() == 0 && m != top()) {
4161       for (uint j = 0; j < m->req(); j++) {
4162         Node* in = m->in(j);
4163         if (in != nullptr) {
4164           dead_nodes.push(in);
4165         }
4166       }
4167       m->disconnect_inputs(this);
4168     }
4169   }
4170 
4171   set_java_calls(frc.get_java_call_count());
4172   set_inner_loops(frc.get_inner_loop_count());
4173 
4174   // No infinite loops, no reason to bail out.
4175   return false;
4176 }
4177 
4178 //-----------------------------too_many_traps----------------------------------
4179 // Report if there are too many traps at the current method and bci.
4180 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
4181 bool Compile::too_many_traps(ciMethod* method,
4182                              int bci,
4183                              Deoptimization::DeoptReason reason) {
4184   ciMethodData* md = method->method_data();
4185   if (md->is_empty()) {
4186     // Assume the trap has not occurred, or that it occurred only
4187     // because of a transient condition during start-up in the interpreter.
4188     return false;
4189   }
4190   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : nullptr;
4191   if (md->has_trap_at(bci, m, reason) != 0) {
4192     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
4193     // Also, if there are multiple reasons, or if there is no per-BCI record,
4194     // assume the worst.
4195     if (log())
4196       log()->elem("observe trap='%s' count='%d'",
4197                   Deoptimization::trap_reason_name(reason),
4198                   md->trap_count(reason));
4199     return true;
4200   } else {
4201     // Ignore method/bci and see if there have been too many globally.
4202     return too_many_traps(reason, md);
4203   }
4204 }
4205 
4206 // Less-accurate variant which does not require a method and bci.
4207 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
4208                              ciMethodData* logmd) {
4209   if (trap_count(reason) >= Deoptimization::per_method_trap_limit(reason)) {
4210     // Too many traps globally.
4211     // Note that we use cumulative trap_count, not just md->trap_count.
4212     if (log()) {
4213       int mcount = (logmd == nullptr)? -1: (int)logmd->trap_count(reason);
4214       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
4215                   Deoptimization::trap_reason_name(reason),
4216                   mcount, trap_count(reason));
4217     }
4218     return true;
4219   } else {
4220     // The coast is clear.
4221     return false;
4222   }
4223 }
4224 
4225 //--------------------------too_many_recompiles--------------------------------
4226 // Report if there are too many recompiles at the current method and bci.
4227 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
4228 // Is not eager to return true, since this will cause the compiler to use
4229 // Action_none for a trap point, to avoid too many recompilations.
4230 bool Compile::too_many_recompiles(ciMethod* method,
4231                                   int bci,
4232                                   Deoptimization::DeoptReason reason) {
4233   ciMethodData* md = method->method_data();
4234   if (md->is_empty()) {
4235     // Assume the trap has not occurred, or that it occurred only
4236     // because of a transient condition during start-up in the interpreter.
4237     return false;
4238   }
4239   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
4240   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
4241   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
4242   Deoptimization::DeoptReason per_bc_reason
4243     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
4244   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : nullptr;
4245   if ((per_bc_reason == Deoptimization::Reason_none
4246        || md->has_trap_at(bci, m, reason) != 0)
4247       // The trap frequency measure we care about is the recompile count:
4248       && md->trap_recompiled_at(bci, m)
4249       && md->overflow_recompile_count() >= bc_cutoff) {
4250     // Do not emit a trap here if it has already caused recompilations.
4251     // Also, if there are multiple reasons, or if there is no per-BCI record,
4252     // assume the worst.
4253     if (log())
4254       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
4255                   Deoptimization::trap_reason_name(reason),
4256                   md->trap_count(reason),
4257                   md->overflow_recompile_count());
4258     return true;
4259   } else if (trap_count(reason) != 0
4260              && decompile_count() >= m_cutoff) {
4261     // Too many recompiles globally, and we have seen this sort of trap.
4262     // Use cumulative decompile_count, not just md->decompile_count.
4263     if (log())
4264       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
4265                   Deoptimization::trap_reason_name(reason),
4266                   md->trap_count(reason), trap_count(reason),
4267                   md->decompile_count(), decompile_count());
4268     return true;
4269   } else {
4270     // The coast is clear.
4271     return false;
4272   }
4273 }
4274 
4275 // Compute when not to trap. Used by matching trap based nodes and
4276 // NullCheck optimization.
4277 void Compile::set_allowed_deopt_reasons() {
4278   _allowed_reasons = 0;
4279   if (is_method_compilation()) {
4280     for (int rs = (int)Deoptimization::Reason_none+1; rs < Compile::trapHistLength; rs++) {
4281       assert(rs < BitsPerInt, "recode bit map");
4282       if (!too_many_traps((Deoptimization::DeoptReason) rs)) {
4283         _allowed_reasons |= nth_bit(rs);
4284       }
4285     }
4286   }
4287 }
4288 
4289 bool Compile::needs_clinit_barrier(ciMethod* method, ciMethod* accessing_method) {
4290   return method->is_static() && needs_clinit_barrier(method->holder(), accessing_method);
4291 }
4292 
4293 bool Compile::needs_clinit_barrier(ciField* field, ciMethod* accessing_method) {
4294   return field->is_static() && needs_clinit_barrier(field->holder(), accessing_method);
4295 }
4296 
4297 bool Compile::needs_clinit_barrier(ciInstanceKlass* holder, ciMethod* accessing_method) {
4298   if (holder->is_initialized()) {
4299     return false;
4300   }
4301   if (holder->is_being_initialized()) {
4302     if (accessing_method->holder() == holder) {
4303       // Access inside a class. The barrier can be elided when access happens in <clinit>,
4304       // <init>, or a static method. In all those cases, there was an initialization
4305       // barrier on the holder klass passed.
4306       if (accessing_method->is_static_initializer() ||
4307           accessing_method->is_object_initializer() ||
4308           accessing_method->is_static()) {
4309         return false;
4310       }
4311     } else if (accessing_method->holder()->is_subclass_of(holder)) {
4312       // Access from a subclass. The barrier can be elided only when access happens in <clinit>.
4313       // In case of <init> or a static method, the barrier is on the subclass is not enough:
4314       // child class can become fully initialized while its parent class is still being initialized.
4315       if (accessing_method->is_static_initializer()) {
4316         return false;
4317       }
4318     }
4319     ciMethod* root = method(); // the root method of compilation
4320     if (root != accessing_method) {
4321       return needs_clinit_barrier(holder, root); // check access in the context of compilation root
4322     }
4323   }
4324   return true;
4325 }
4326 
4327 #ifndef PRODUCT
4328 //------------------------------verify_bidirectional_edges---------------------
4329 // For each input edge to a node (ie - for each Use-Def edge), verify that
4330 // there is a corresponding Def-Use edge.
4331 void Compile::verify_bidirectional_edges(Unique_Node_List& visited, const Unique_Node_List* root_and_safepoints) const {
4332   // Allocate stack of size C->live_nodes()/16 to avoid frequent realloc
4333   uint stack_size = live_nodes() >> 4;
4334   Node_List nstack(MAX2(stack_size, (uint) OptoNodeListSize));
4335   if (root_and_safepoints != nullptr) {
4336     assert(root_and_safepoints->member(_root), "root is not in root_and_safepoints");
4337     for (uint i = 0, limit = root_and_safepoints->size(); i < limit; i++) {
4338       Node* root_or_safepoint = root_and_safepoints->at(i);
4339       // If the node is a safepoint, let's check if it still has a control input
4340       // Lack of control input signifies that this node was killed by CCP or
4341       // recursively by remove_globally_dead_node and it shouldn't be a starting
4342       // point.
4343       if (!root_or_safepoint->is_SafePoint() || root_or_safepoint->in(0) != nullptr) {
4344         nstack.push(root_or_safepoint);
4345       }
4346     }
4347   } else {
4348     nstack.push(_root);
4349   }
4350 
4351   while (nstack.size() > 0) {
4352     Node* n = nstack.pop();
4353     if (visited.member(n)) {
4354       continue;
4355     }
4356     visited.push(n);
4357 
4358     // Walk over all input edges, checking for correspondence
4359     uint length = n->len();
4360     for (uint i = 0; i < length; i++) {
4361       Node* in = n->in(i);
4362       if (in != nullptr && !visited.member(in)) {
4363         nstack.push(in); // Put it on stack
4364       }
4365       if (in != nullptr && !in->is_top()) {
4366         // Count instances of `next`
4367         int cnt = 0;
4368         for (uint idx = 0; idx < in->_outcnt; idx++) {
4369           if (in->_out[idx] == n) {
4370             cnt++;
4371           }
4372         }
4373         assert(cnt > 0, "Failed to find Def-Use edge.");
4374         // Check for duplicate edges
4375         // walk the input array downcounting the input edges to n
4376         for (uint j = 0; j < length; j++) {
4377           if (n->in(j) == in) {
4378             cnt--;
4379           }
4380         }
4381         assert(cnt == 0, "Mismatched edge count.");
4382       } else if (in == nullptr) {
4383         assert(i == 0 || i >= n->req() ||
4384                n->is_Region() || n->is_Phi() || n->is_ArrayCopy() ||
4385                (n->is_Unlock() && i == (n->req() - 1)) ||
4386                (n->is_MemBar() && i == 5), // the precedence edge to a membar can be removed during macro node expansion
4387               "only region, phi, arraycopy, unlock or membar nodes have null data edges");
4388       } else {
4389         assert(in->is_top(), "sanity");
4390         // Nothing to check.
4391       }
4392     }
4393   }
4394 }
4395 
4396 //------------------------------verify_graph_edges---------------------------
4397 // Walk the Graph and verify that there is a one-to-one correspondence
4398 // between Use-Def edges and Def-Use edges in the graph.
4399 void Compile::verify_graph_edges(bool no_dead_code, const Unique_Node_List* root_and_safepoints) const {
4400   if (VerifyGraphEdges) {
4401     Unique_Node_List visited;
4402 
4403     // Call graph walk to check edges
4404     verify_bidirectional_edges(visited, root_and_safepoints);
4405     if (no_dead_code) {
4406       // Now make sure that no visited node is used by an unvisited node.
4407       bool dead_nodes = false;
4408       Unique_Node_List checked;
4409       while (visited.size() > 0) {
4410         Node* n = visited.pop();
4411         checked.push(n);
4412         for (uint i = 0; i < n->outcnt(); i++) {
4413           Node* use = n->raw_out(i);
4414           if (checked.member(use))  continue;  // already checked
4415           if (visited.member(use))  continue;  // already in the graph
4416           if (use->is_Con())        continue;  // a dead ConNode is OK
4417           // At this point, we have found a dead node which is DU-reachable.
4418           if (!dead_nodes) {
4419             tty->print_cr("*** Dead nodes reachable via DU edges:");
4420             dead_nodes = true;
4421           }
4422           use->dump(2);
4423           tty->print_cr("---");
4424           checked.push(use);  // No repeats; pretend it is now checked.
4425         }
4426       }
4427       assert(!dead_nodes, "using nodes must be reachable from root");
4428     }
4429   }
4430 }
4431 #endif
4432 
4433 // The Compile object keeps track of failure reasons separately from the ciEnv.
4434 // This is required because there is not quite a 1-1 relation between the
4435 // ciEnv and its compilation task and the Compile object.  Note that one
4436 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
4437 // to backtrack and retry without subsuming loads.  Other than this backtracking
4438 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
4439 // by the logic in C2Compiler.
4440 void Compile::record_failure(const char* reason DEBUG_ONLY(COMMA bool allow_multiple_failures)) {
4441   if (log() != nullptr) {
4442     log()->elem("failure reason='%s' phase='compile'", reason);
4443   }
4444   if (_failure_reason.get() == nullptr) {
4445     // Record the first failure reason.
4446     _failure_reason.set(reason);
4447     if (CaptureBailoutInformation) {
4448       _first_failure_details = new CompilationFailureInfo(reason);
4449     }
4450   } else {
4451     assert(!StressBailout || allow_multiple_failures, "should have handled previous failure.");
4452   }
4453 
4454   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
4455     C->print_method(PHASE_FAILURE, 1);
4456   }
4457   _root = nullptr;  // flush the graph, too
4458 }
4459 
4460 Compile::TracePhase::TracePhase(const char* name, PhaseTraceId id)
4461   : TraceTime(name, &Phase::timers[id], CITime, CITimeVerbose),
4462     _compile(Compile::current()),
4463     _log(nullptr),
4464     _dolog(CITimeVerbose)
4465 {
4466   assert(_compile != nullptr, "sanity check");
4467   assert(id != PhaseTraceId::_t_none, "Don't use none");
4468   if (_dolog) {
4469     _log = _compile->log();
4470   }
4471   if (_log != nullptr) {
4472     _log->begin_head("phase name='%s' nodes='%d' live='%d'", phase_name(), _compile->unique(), _compile->live_nodes());
4473     _log->stamp();
4474     _log->end_head();
4475   }
4476 
4477   // Inform memory statistic, if enabled
4478   if (CompilationMemoryStatistic::enabled()) {
4479     CompilationMemoryStatistic::on_phase_start((int)id, name);
4480   }
4481 }
4482 
4483 Compile::TracePhase::TracePhase(PhaseTraceId id)
4484   : TracePhase(Phase::get_phase_trace_id_text(id), id) {}
4485 
4486 Compile::TracePhase::~TracePhase() {
4487 
4488   // Inform memory statistic, if enabled
4489   if (CompilationMemoryStatistic::enabled()) {
4490     CompilationMemoryStatistic::on_phase_end();
4491   }
4492 
4493   if (_compile->failing_internal()) {
4494     if (_log != nullptr) {
4495       _log->done("phase");
4496     }
4497     return; // timing code, not stressing bailouts.
4498   }
4499 #ifdef ASSERT
4500   if (PrintIdealNodeCount) {
4501     tty->print_cr("phase name='%s' nodes='%d' live='%d' live_graph_walk='%d'",
4502                   phase_name(), _compile->unique(), _compile->live_nodes(), _compile->count_live_nodes_by_graph_walk());
4503   }
4504 
4505   if (VerifyIdealNodeCount) {
4506     _compile->print_missing_nodes();
4507   }
4508 #endif
4509 
4510   if (_log != nullptr) {
4511     _log->done("phase name='%s' nodes='%d' live='%d'", phase_name(), _compile->unique(), _compile->live_nodes());
4512   }
4513 }
4514 
4515 //----------------------------static_subtype_check-----------------------------
4516 // Shortcut important common cases when superklass is exact:
4517 // (0) superklass is java.lang.Object (can occur in reflective code)
4518 // (1) subklass is already limited to a subtype of superklass => always ok
4519 // (2) subklass does not overlap with superklass => always fail
4520 // (3) superklass has NO subtypes and we can check with a simple compare.
4521 Compile::SubTypeCheckResult Compile::static_subtype_check(const TypeKlassPtr* superk, const TypeKlassPtr* subk, bool skip) {
4522   if (skip) {
4523     return SSC_full_test;       // Let caller generate the general case.
4524   }
4525 
4526   if (subk->is_java_subtype_of(superk)) {
4527     return SSC_always_true; // (0) and (1)  this test cannot fail
4528   }
4529 
4530   if (!subk->maybe_java_subtype_of(superk)) {
4531     return SSC_always_false; // (2) true path dead; no dynamic test needed
4532   }
4533 
4534   const Type* superelem = superk;
4535   if (superk->isa_aryklassptr()) {
4536     int ignored;
4537     superelem = superk->is_aryklassptr()->base_element_type(ignored);
4538   }
4539 
4540   if (superelem->isa_instklassptr()) {
4541     ciInstanceKlass* ik = superelem->is_instklassptr()->instance_klass();
4542     if (!ik->has_subklass()) {
4543       if (!ik->is_final()) {
4544         // Add a dependency if there is a chance of a later subclass.
4545         dependencies()->assert_leaf_type(ik);
4546       }
4547       if (!superk->maybe_java_subtype_of(subk)) {
4548         return SSC_always_false;
4549       }
4550       return SSC_easy_test;     // (3) caller can do a simple ptr comparison
4551     }
4552   } else {
4553     // A primitive array type has no subtypes.
4554     return SSC_easy_test;       // (3) caller can do a simple ptr comparison
4555   }
4556 
4557   return SSC_full_test;
4558 }
4559 
4560 Node* Compile::conv_I2X_index(PhaseGVN* phase, Node* idx, const TypeInt* sizetype, Node* ctrl) {
4561 #ifdef _LP64
4562   // The scaled index operand to AddP must be a clean 64-bit value.
4563   // Java allows a 32-bit int to be incremented to a negative
4564   // value, which appears in a 64-bit register as a large
4565   // positive number.  Using that large positive number as an
4566   // operand in pointer arithmetic has bad consequences.
4567   // On the other hand, 32-bit overflow is rare, and the possibility
4568   // can often be excluded, if we annotate the ConvI2L node with
4569   // a type assertion that its value is known to be a small positive
4570   // number.  (The prior range check has ensured this.)
4571   // This assertion is used by ConvI2LNode::Ideal.
4572   int index_max = max_jint - 1;  // array size is max_jint, index is one less
4573   if (sizetype != nullptr && sizetype->_hi > 0) {
4574     index_max = sizetype->_hi - 1;
4575   }
4576   const TypeInt* iidxtype = TypeInt::make(0, index_max, Type::WidenMax);
4577   idx = constrained_convI2L(phase, idx, iidxtype, ctrl);
4578 #endif
4579   return idx;
4580 }
4581 
4582 // Convert integer value to a narrowed long type dependent on ctrl (for example, a range check)
4583 Node* Compile::constrained_convI2L(PhaseGVN* phase, Node* value, const TypeInt* itype, Node* ctrl, bool carry_dependency) {
4584   if (ctrl != nullptr) {
4585     // Express control dependency by a CastII node with a narrow type.
4586     // Make the CastII node dependent on the control input to prevent the narrowed ConvI2L
4587     // node from floating above the range check during loop optimizations. Otherwise, the
4588     // ConvI2L node may be eliminated independently of the range check, causing the data path
4589     // to become TOP while the control path is still there (although it's unreachable).
4590     value = new CastIINode(ctrl, value, itype, carry_dependency ? ConstraintCastNode::DependencyType::NonFloatingNarrowing : ConstraintCastNode::DependencyType::FloatingNarrowing, true /* range check dependency */);
4591     value = phase->transform(value);
4592   }
4593   const TypeLong* ltype = TypeLong::make(itype->_lo, itype->_hi, itype->_widen);
4594   return phase->transform(new ConvI2LNode(value, ltype));
4595 }
4596 
4597 void Compile::dump_print_inlining() {
4598   inline_printer()->print_on(tty);
4599 }
4600 
4601 void Compile::log_late_inline(CallGenerator* cg) {
4602   if (log() != nullptr) {
4603     log()->head("late_inline method='%d' inline_id='" JLONG_FORMAT "'", log()->identify(cg->method()),
4604                 cg->unique_id());
4605     JVMState* p = cg->call_node()->jvms();
4606     while (p != nullptr) {
4607       log()->elem("jvms bci='%d' method='%d'", p->bci(), log()->identify(p->method()));
4608       p = p->caller();
4609     }
4610     log()->tail("late_inline");
4611   }
4612 }
4613 
4614 void Compile::log_late_inline_failure(CallGenerator* cg, const char* msg) {
4615   log_late_inline(cg);
4616   if (log() != nullptr) {
4617     log()->inline_fail(msg);
4618   }
4619 }
4620 
4621 void Compile::log_inline_id(CallGenerator* cg) {
4622   if (log() != nullptr) {
4623     // The LogCompilation tool needs a unique way to identify late
4624     // inline call sites. This id must be unique for this call site in
4625     // this compilation. Try to have it unique across compilations as
4626     // well because it can be convenient when grepping through the log
4627     // file.
4628     // Distinguish OSR compilations from others in case CICountOSR is
4629     // on.
4630     jlong id = ((jlong)unique()) + (((jlong)compile_id()) << 33) + (CICountOSR && is_osr_compilation() ? ((jlong)1) << 32 : 0);
4631     cg->set_unique_id(id);
4632     log()->elem("inline_id id='" JLONG_FORMAT "'", id);
4633   }
4634 }
4635 
4636 void Compile::log_inline_failure(const char* msg) {
4637   if (C->log() != nullptr) {
4638     C->log()->inline_fail(msg);
4639   }
4640 }
4641 
4642 
4643 // Dump inlining replay data to the stream.
4644 // Don't change thread state and acquire any locks.
4645 void Compile::dump_inline_data(outputStream* out) {
4646   InlineTree* inl_tree = ilt();
4647   if (inl_tree != nullptr) {
4648     out->print(" inline %d", inl_tree->count());
4649     inl_tree->dump_replay_data(out);
4650   }
4651 }
4652 
4653 void Compile::dump_inline_data_reduced(outputStream* out) {
4654   assert(ReplayReduce, "");
4655 
4656   InlineTree* inl_tree = ilt();
4657   if (inl_tree == nullptr) {
4658     return;
4659   }
4660   // Enable iterative replay file reduction
4661   // Output "compile" lines for depth 1 subtrees,
4662   // simulating that those trees were compiled
4663   // instead of inlined.
4664   for (int i = 0; i < inl_tree->subtrees().length(); ++i) {
4665     InlineTree* sub = inl_tree->subtrees().at(i);
4666     if (sub->inline_level() != 1) {
4667       continue;
4668     }
4669 
4670     ciMethod* method = sub->method();
4671     int entry_bci = -1;
4672     int comp_level = env()->task()->comp_level();
4673     out->print("compile ");
4674     method->dump_name_as_ascii(out);
4675     out->print(" %d %d", entry_bci, comp_level);
4676     out->print(" inline %d", sub->count());
4677     sub->dump_replay_data(out, -1);
4678     out->cr();
4679   }
4680 }
4681 
4682 int Compile::cmp_expensive_nodes(Node* n1, Node* n2) {
4683   if (n1->Opcode() < n2->Opcode())      return -1;
4684   else if (n1->Opcode() > n2->Opcode()) return 1;
4685 
4686   assert(n1->req() == n2->req(), "can't compare %s nodes: n1->req() = %d, n2->req() = %d", NodeClassNames[n1->Opcode()], n1->req(), n2->req());
4687   for (uint i = 1; i < n1->req(); i++) {
4688     if (n1->in(i) < n2->in(i))      return -1;
4689     else if (n1->in(i) > n2->in(i)) return 1;
4690   }
4691 
4692   return 0;
4693 }
4694 
4695 int Compile::cmp_expensive_nodes(Node** n1p, Node** n2p) {
4696   Node* n1 = *n1p;
4697   Node* n2 = *n2p;
4698 
4699   return cmp_expensive_nodes(n1, n2);
4700 }
4701 
4702 void Compile::sort_expensive_nodes() {
4703   if (!expensive_nodes_sorted()) {
4704     _expensive_nodes.sort(cmp_expensive_nodes);
4705   }
4706 }
4707 
4708 bool Compile::expensive_nodes_sorted() const {
4709   for (int i = 1; i < _expensive_nodes.length(); i++) {
4710     if (cmp_expensive_nodes(_expensive_nodes.adr_at(i), _expensive_nodes.adr_at(i-1)) < 0) {
4711       return false;
4712     }
4713   }
4714   return true;
4715 }
4716 
4717 bool Compile::should_optimize_expensive_nodes(PhaseIterGVN &igvn) {
4718   if (_expensive_nodes.length() == 0) {
4719     return false;
4720   }
4721 
4722   assert(OptimizeExpensiveOps, "optimization off?");
4723 
4724   // Take this opportunity to remove dead nodes from the list
4725   int j = 0;
4726   for (int i = 0; i < _expensive_nodes.length(); i++) {
4727     Node* n = _expensive_nodes.at(i);
4728     if (!n->is_unreachable(igvn)) {
4729       assert(n->is_expensive(), "should be expensive");
4730       _expensive_nodes.at_put(j, n);
4731       j++;
4732     }
4733   }
4734   _expensive_nodes.trunc_to(j);
4735 
4736   // Then sort the list so that similar nodes are next to each other
4737   // and check for at least two nodes of identical kind with same data
4738   // inputs.
4739   sort_expensive_nodes();
4740 
4741   for (int i = 0; i < _expensive_nodes.length()-1; i++) {
4742     if (cmp_expensive_nodes(_expensive_nodes.adr_at(i), _expensive_nodes.adr_at(i+1)) == 0) {
4743       return true;
4744     }
4745   }
4746 
4747   return false;
4748 }
4749 
4750 void Compile::cleanup_expensive_nodes(PhaseIterGVN &igvn) {
4751   if (_expensive_nodes.length() == 0) {
4752     return;
4753   }
4754 
4755   assert(OptimizeExpensiveOps, "optimization off?");
4756 
4757   // Sort to bring similar nodes next to each other and clear the
4758   // control input of nodes for which there's only a single copy.
4759   sort_expensive_nodes();
4760 
4761   int j = 0;
4762   int identical = 0;
4763   int i = 0;
4764   bool modified = false;
4765   for (; i < _expensive_nodes.length()-1; i++) {
4766     assert(j <= i, "can't write beyond current index");
4767     if (_expensive_nodes.at(i)->Opcode() == _expensive_nodes.at(i+1)->Opcode()) {
4768       identical++;
4769       _expensive_nodes.at_put(j++, _expensive_nodes.at(i));
4770       continue;
4771     }
4772     if (identical > 0) {
4773       _expensive_nodes.at_put(j++, _expensive_nodes.at(i));
4774       identical = 0;
4775     } else {
4776       Node* n = _expensive_nodes.at(i);
4777       igvn.replace_input_of(n, 0, nullptr);
4778       igvn.hash_insert(n);
4779       modified = true;
4780     }
4781   }
4782   if (identical > 0) {
4783     _expensive_nodes.at_put(j++, _expensive_nodes.at(i));
4784   } else if (_expensive_nodes.length() >= 1) {
4785     Node* n = _expensive_nodes.at(i);
4786     igvn.replace_input_of(n, 0, nullptr);
4787     igvn.hash_insert(n);
4788     modified = true;
4789   }
4790   _expensive_nodes.trunc_to(j);
4791   if (modified) {
4792     igvn.optimize();
4793   }
4794 }
4795 
4796 void Compile::add_expensive_node(Node * n) {
4797   assert(!_expensive_nodes.contains(n), "duplicate entry in expensive list");
4798   assert(n->is_expensive(), "expensive nodes with non-null control here only");
4799   assert(!n->is_CFG() && !n->is_Mem(), "no cfg or memory nodes here");
4800   if (OptimizeExpensiveOps) {
4801     _expensive_nodes.append(n);
4802   } else {
4803     // Clear control input and let IGVN optimize expensive nodes if
4804     // OptimizeExpensiveOps is off.
4805     n->set_req(0, nullptr);
4806   }
4807 }
4808 
4809 /**
4810  * Track coarsened Lock and Unlock nodes.
4811  */
4812 
4813 class Lock_List : public Node_List {
4814   uint _origin_cnt;
4815 public:
4816   Lock_List(Arena *a, uint cnt) : Node_List(a), _origin_cnt(cnt) {}
4817   uint origin_cnt() const { return _origin_cnt; }
4818 };
4819 
4820 void Compile::add_coarsened_locks(GrowableArray<AbstractLockNode*>& locks) {
4821   int length = locks.length();
4822   if (length > 0) {
4823     // Have to keep this list until locks elimination during Macro nodes elimination.
4824     Lock_List* locks_list = new (comp_arena()) Lock_List(comp_arena(), length);
4825     AbstractLockNode* alock = locks.at(0);
4826     BoxLockNode* box = alock->box_node()->as_BoxLock();
4827     for (int i = 0; i < length; i++) {
4828       AbstractLockNode* lock = locks.at(i);
4829       assert(lock->is_coarsened(), "expecting only coarsened AbstractLock nodes, but got '%s'[%d] node", lock->Name(), lock->_idx);
4830       locks_list->push(lock);
4831       BoxLockNode* this_box = lock->box_node()->as_BoxLock();
4832       if (this_box != box) {
4833         // Locking regions (BoxLock) could be Unbalanced here:
4834         //  - its coarsened locks were eliminated in earlier
4835         //    macro nodes elimination followed by loop unroll
4836         //  - it is OSR locking region (no Lock node)
4837         // Preserve Unbalanced status in such cases.
4838         if (!this_box->is_unbalanced()) {
4839           this_box->set_coarsened();
4840         }
4841         if (!box->is_unbalanced()) {
4842           box->set_coarsened();
4843         }
4844       }
4845     }
4846     _coarsened_locks.append(locks_list);
4847   }
4848 }
4849 
4850 void Compile::remove_useless_coarsened_locks(Unique_Node_List& useful) {
4851   int count = coarsened_count();
4852   for (int i = 0; i < count; i++) {
4853     Node_List* locks_list = _coarsened_locks.at(i);
4854     for (uint j = 0; j < locks_list->size(); j++) {
4855       Node* lock = locks_list->at(j);
4856       assert(lock->is_AbstractLock(), "sanity");
4857       if (!useful.member(lock)) {
4858         locks_list->yank(lock);
4859       }
4860     }
4861   }
4862 }
4863 
4864 void Compile::remove_coarsened_lock(Node* n) {
4865   if (n->is_AbstractLock()) {
4866     int count = coarsened_count();
4867     for (int i = 0; i < count; i++) {
4868       Node_List* locks_list = _coarsened_locks.at(i);
4869       locks_list->yank(n);
4870     }
4871   }
4872 }
4873 
4874 bool Compile::coarsened_locks_consistent() {
4875   int count = coarsened_count();
4876   for (int i = 0; i < count; i++) {
4877     bool unbalanced = false;
4878     bool modified = false; // track locks kind modifications
4879     Lock_List* locks_list = (Lock_List*)_coarsened_locks.at(i);
4880     uint size = locks_list->size();
4881     if (size == 0) {
4882       unbalanced = false; // All locks were eliminated - good
4883     } else if (size != locks_list->origin_cnt()) {
4884       unbalanced = true; // Some locks were removed from list
4885     } else {
4886       for (uint j = 0; j < size; j++) {
4887         Node* lock = locks_list->at(j);
4888         // All nodes in group should have the same state (modified or not)
4889         if (!lock->as_AbstractLock()->is_coarsened()) {
4890           if (j == 0) {
4891             // first on list was modified, the rest should be too for consistency
4892             modified = true;
4893           } else if (!modified) {
4894             // this lock was modified but previous locks on the list were not
4895             unbalanced = true;
4896             break;
4897           }
4898         } else if (modified) {
4899           // previous locks on list were modified but not this lock
4900           unbalanced = true;
4901           break;
4902         }
4903       }
4904     }
4905     if (unbalanced) {
4906       // unbalanced monitor enter/exit - only some [un]lock nodes were removed or modified
4907 #ifdef ASSERT
4908       if (PrintEliminateLocks) {
4909         tty->print_cr("=== unbalanced coarsened locks ===");
4910         for (uint l = 0; l < size; l++) {
4911           locks_list->at(l)->dump();
4912         }
4913       }
4914 #endif
4915       record_failure(C2Compiler::retry_no_locks_coarsening());
4916       return false;
4917     }
4918   }
4919   return true;
4920 }
4921 
4922 // Mark locking regions (identified by BoxLockNode) as unbalanced if
4923 // locks coarsening optimization removed Lock/Unlock nodes from them.
4924 // Such regions become unbalanced because coarsening only removes part
4925 // of Lock/Unlock nodes in region. As result we can't execute other
4926 // locks elimination optimizations which assume all code paths have
4927 // corresponding pair of Lock/Unlock nodes - they are balanced.
4928 void Compile::mark_unbalanced_boxes() const {
4929   int count = coarsened_count();
4930   for (int i = 0; i < count; i++) {
4931     Node_List* locks_list = _coarsened_locks.at(i);
4932     uint size = locks_list->size();
4933     if (size > 0) {
4934       AbstractLockNode* alock = locks_list->at(0)->as_AbstractLock();
4935       BoxLockNode* box = alock->box_node()->as_BoxLock();
4936       if (alock->is_coarsened()) {
4937         // coarsened_locks_consistent(), which is called before this method, verifies
4938         // that the rest of Lock/Unlock nodes on locks_list are also coarsened.
4939         assert(!box->is_eliminated(), "regions with coarsened locks should not be marked as eliminated");
4940         for (uint j = 1; j < size; j++) {
4941           assert(locks_list->at(j)->as_AbstractLock()->is_coarsened(), "only coarsened locks are expected here");
4942           BoxLockNode* this_box = locks_list->at(j)->as_AbstractLock()->box_node()->as_BoxLock();
4943           if (box != this_box) {
4944             assert(!this_box->is_eliminated(), "regions with coarsened locks should not be marked as eliminated");
4945             box->set_unbalanced();
4946             this_box->set_unbalanced();
4947           }
4948         }
4949       }
4950     }
4951   }
4952 }
4953 
4954 /**
4955  * Remove the speculative part of types and clean up the graph
4956  */
4957 void Compile::remove_speculative_types(PhaseIterGVN &igvn) {
4958   if (UseTypeSpeculation) {
4959     Unique_Node_List worklist;
4960     worklist.push(root());
4961     int modified = 0;
4962     // Go over all type nodes that carry a speculative type, drop the
4963     // speculative part of the type and enqueue the node for an igvn
4964     // which may optimize it out.
4965     for (uint next = 0; next < worklist.size(); ++next) {
4966       Node *n  = worklist.at(next);
4967       if (n->is_Type()) {
4968         TypeNode* tn = n->as_Type();
4969         const Type* t = tn->type();
4970         const Type* t_no_spec = t->remove_speculative();
4971         if (t_no_spec != t) {
4972           bool in_hash = igvn.hash_delete(n);
4973           assert(in_hash || n->hash() == Node::NO_HASH, "node should be in igvn hash table");
4974           tn->set_type(t_no_spec);
4975           igvn.hash_insert(n);
4976           igvn._worklist.push(n); // give it a chance to go away
4977           modified++;
4978         }
4979       }
4980       // Iterate over outs - endless loops is unreachable from below
4981       for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
4982         Node *m = n->fast_out(i);
4983         if (not_a_node(m)) {
4984           continue;
4985         }
4986         worklist.push(m);
4987       }
4988     }
4989     // Drop the speculative part of all types in the igvn's type table
4990     igvn.remove_speculative_types();
4991     if (modified > 0) {
4992       igvn.optimize();
4993       if (failing())  return;
4994     }
4995 #ifdef ASSERT
4996     // Verify that after the IGVN is over no speculative type has resurfaced
4997     worklist.clear();
4998     worklist.push(root());
4999     for (uint next = 0; next < worklist.size(); ++next) {
5000       Node *n  = worklist.at(next);
5001       const Type* t = igvn.type_or_null(n);
5002       assert((t == nullptr) || (t == t->remove_speculative()), "no more speculative types");
5003       if (n->is_Type()) {
5004         t = n->as_Type()->type();
5005         assert(t == t->remove_speculative(), "no more speculative types");
5006       }
5007       // Iterate over outs - endless loops is unreachable from below
5008       for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
5009         Node *m = n->fast_out(i);
5010         if (not_a_node(m)) {
5011           continue;
5012         }
5013         worklist.push(m);
5014       }
5015     }
5016     igvn.check_no_speculative_types();
5017 #endif
5018   }
5019 }
5020 
5021 // Auxiliary methods to support randomized stressing/fuzzing.
5022 
5023 void Compile::initialize_stress_seed(const DirectiveSet* directive) {
5024   if (FLAG_IS_DEFAULT(StressSeed) || (FLAG_IS_ERGO(StressSeed) && directive->RepeatCompilationOption)) {
5025     _stress_seed = static_cast<uint>(Ticks::now().nanoseconds());
5026     FLAG_SET_ERGO(StressSeed, _stress_seed);
5027   } else {
5028     _stress_seed = StressSeed;
5029   }
5030   if (_log != nullptr) {
5031     _log->elem("stress_test seed='%u'", _stress_seed);
5032   }
5033 }
5034 
5035 int Compile::random() {
5036   _stress_seed = os::next_random(_stress_seed);
5037   return static_cast<int>(_stress_seed);
5038 }
5039 
5040 // This method can be called the arbitrary number of times, with current count
5041 // as the argument. The logic allows selecting a single candidate from the
5042 // running list of candidates as follows:
5043 //    int count = 0;
5044 //    Cand* selected = null;
5045 //    while(cand = cand->next()) {
5046 //      if (randomized_select(++count)) {
5047 //        selected = cand;
5048 //      }
5049 //    }
5050 //
5051 // Including count equalizes the chances any candidate is "selected".
5052 // This is useful when we don't have the complete list of candidates to choose
5053 // from uniformly. In this case, we need to adjust the randomicity of the
5054 // selection, or else we will end up biasing the selection towards the latter
5055 // candidates.
5056 //
5057 // Quick back-envelope calculation shows that for the list of n candidates
5058 // the equal probability for the candidate to persist as "best" can be
5059 // achieved by replacing it with "next" k-th candidate with the probability
5060 // of 1/k. It can be easily shown that by the end of the run, the
5061 // probability for any candidate is converged to 1/n, thus giving the
5062 // uniform distribution among all the candidates.
5063 //
5064 // We don't care about the domain size as long as (RANDOMIZED_DOMAIN / count) is large.
5065 #define RANDOMIZED_DOMAIN_POW 29
5066 #define RANDOMIZED_DOMAIN (1 << RANDOMIZED_DOMAIN_POW)
5067 #define RANDOMIZED_DOMAIN_MASK ((1 << (RANDOMIZED_DOMAIN_POW + 1)) - 1)
5068 bool Compile::randomized_select(int count) {
5069   assert(count > 0, "only positive");
5070   return (random() & RANDOMIZED_DOMAIN_MASK) < (RANDOMIZED_DOMAIN / count);
5071 }
5072 
5073 #ifdef ASSERT
5074 // Failures are geometrically distributed with probability 1/StressBailoutMean.
5075 bool Compile::fail_randomly() {
5076   if ((random() % StressBailoutMean) != 0) {
5077     return false;
5078   }
5079   record_failure("StressBailout");
5080   return true;
5081 }
5082 
5083 bool Compile::failure_is_artificial() {
5084   return C->failure_reason_is("StressBailout");
5085 }
5086 #endif
5087 
5088 CloneMap&     Compile::clone_map()                 { return _clone_map; }
5089 void          Compile::set_clone_map(Dict* d)      { _clone_map._dict = d; }
5090 
5091 void NodeCloneInfo::dump_on(outputStream* st) const {
5092   st->print(" {%d:%d} ", idx(), gen());
5093 }
5094 
5095 void CloneMap::clone(Node* old, Node* nnn, int gen) {
5096   uint64_t val = value(old->_idx);
5097   NodeCloneInfo cio(val);
5098   assert(val != 0, "old node should be in the map");
5099   NodeCloneInfo cin(cio.idx(), gen + cio.gen());
5100   insert(nnn->_idx, cin.get());
5101 #ifndef PRODUCT
5102   if (is_debug()) {
5103     tty->print_cr("CloneMap::clone inserted node %d info {%d:%d} into CloneMap", nnn->_idx, cin.idx(), cin.gen());
5104   }
5105 #endif
5106 }
5107 
5108 void CloneMap::verify_insert_and_clone(Node* old, Node* nnn, int gen) {
5109   NodeCloneInfo cio(value(old->_idx));
5110   if (cio.get() == 0) {
5111     cio.set(old->_idx, 0);
5112     insert(old->_idx, cio.get());
5113 #ifndef PRODUCT
5114     if (is_debug()) {
5115       tty->print_cr("CloneMap::verify_insert_and_clone inserted node %d info {%d:%d} into CloneMap", old->_idx, cio.idx(), cio.gen());
5116     }
5117 #endif
5118   }
5119   clone(old, nnn, gen);
5120 }
5121 
5122 int CloneMap::max_gen() const {
5123   int g = 0;
5124   DictI di(_dict);
5125   for(; di.test(); ++di) {
5126     int t = gen(di._key);
5127     if (g < t) {
5128       g = t;
5129 #ifndef PRODUCT
5130       if (is_debug()) {
5131         tty->print_cr("CloneMap::max_gen() update max=%d from %d", g, _2_node_idx_t(di._key));
5132       }
5133 #endif
5134     }
5135   }
5136   return g;
5137 }
5138 
5139 void CloneMap::dump(node_idx_t key, outputStream* st) const {
5140   uint64_t val = value(key);
5141   if (val != 0) {
5142     NodeCloneInfo ni(val);
5143     ni.dump_on(st);
5144   }
5145 }
5146 
5147 void Compile::shuffle_macro_nodes() {
5148   shuffle_array(*C, _macro_nodes);
5149 }
5150 
5151 // Move Allocate nodes to the start of the list
5152 void Compile::sort_macro_nodes() {
5153   int count = macro_count();
5154   int allocates = 0;
5155   for (int i = 0; i < count; i++) {
5156     Node* n = macro_node(i);
5157     if (n->is_Allocate()) {
5158       if (i != allocates) {
5159         Node* tmp = macro_node(allocates);
5160         _macro_nodes.at_put(allocates, n);
5161         _macro_nodes.at_put(i, tmp);
5162       }
5163       allocates++;
5164     }
5165   }
5166 }
5167 
5168 void Compile::print_method(CompilerPhaseType compile_phase, int level, Node* n) {
5169   if (failing_internal()) { return; } // failing_internal to not stress bailouts from printing code.
5170   EventCompilerPhase event(UNTIMED);
5171   if (event.should_commit()) {
5172     CompilerEvent::PhaseEvent::post(event, C->_latest_stage_start_counter, compile_phase, C->_compile_id, level);
5173   }
5174 #ifndef PRODUCT
5175   ResourceMark rm;
5176   stringStream ss;
5177   ss.print_raw(CompilerPhaseTypeHelper::to_description(compile_phase));
5178   int iter = ++_igv_phase_iter[compile_phase];
5179   if (iter > 1) {
5180     ss.print(" %d", iter);
5181   }
5182   if (n != nullptr) {
5183     ss.print(": %d %s", n->_idx, NodeClassNames[n->Opcode()]);
5184     if (n->is_Call()) {
5185       CallNode* call = n->as_Call();
5186       if (call->_name != nullptr) {
5187         // E.g. uncommon traps etc.
5188         ss.print(" - %s", call->_name);
5189       } else if (call->is_CallJava()) {
5190         CallJavaNode* call_java = call->as_CallJava();
5191         if (call_java->method() != nullptr) {
5192           ss.print(" -");
5193           call_java->method()->print_short_name(&ss);
5194         }
5195       }
5196     }
5197   }
5198 
5199   const char* name = ss.as_string();
5200   if (should_print_igv(level)) {
5201     _igv_printer->print_graph(name);
5202   }
5203   if (should_print_phase(level)) {
5204     print_phase(name);
5205   }
5206   if (should_print_ideal_phase(compile_phase)) {
5207     print_ideal_ir(CompilerPhaseTypeHelper::to_name(compile_phase));
5208   }
5209 #endif
5210   C->_latest_stage_start_counter.stamp();
5211 }
5212 
5213 // Only used from CompileWrapper
5214 void Compile::begin_method() {
5215 #ifndef PRODUCT
5216   if (_method != nullptr && should_print_igv(1)) {
5217     _igv_printer->begin_method();
5218   }
5219 #endif
5220   C->_latest_stage_start_counter.stamp();
5221 }
5222 
5223 // Only used from CompileWrapper
5224 void Compile::end_method() {
5225   EventCompilerPhase event(UNTIMED);
5226   if (event.should_commit()) {
5227     CompilerEvent::PhaseEvent::post(event, C->_latest_stage_start_counter, PHASE_END, C->_compile_id, 1);
5228   }
5229 
5230 #ifndef PRODUCT
5231   if (_method != nullptr && should_print_igv(1)) {
5232     _igv_printer->end_method();
5233   }
5234 #endif
5235 }
5236 
5237 #ifndef PRODUCT
5238 bool Compile::should_print_phase(const int level) const {
5239   return PrintPhaseLevel >= 0 && directive()->PhasePrintLevelOption >= level &&
5240          _method != nullptr; // Do not print phases for stubs.
5241 }
5242 
5243 bool Compile::should_print_ideal_phase(CompilerPhaseType cpt) const {
5244   return _directive->should_print_ideal_phase(cpt);
5245 }
5246 
5247 void Compile::init_igv() {
5248   if (_igv_printer == nullptr) {
5249     _igv_printer = IdealGraphPrinter::printer();
5250     _igv_printer->set_compile(this);
5251   }
5252 }
5253 
5254 bool Compile::should_print_igv(const int level) {
5255   PRODUCT_RETURN_(return false;);
5256 
5257   if (PrintIdealGraphLevel < 0) { // disabled by the user
5258     return false;
5259   }
5260 
5261   bool need = directive()->IGVPrintLevelOption >= level;
5262   if (need) {
5263     Compile::init_igv();
5264   }
5265   return need;
5266 }
5267 
5268 IdealGraphPrinter* Compile::_debug_file_printer = nullptr;
5269 IdealGraphPrinter* Compile::_debug_network_printer = nullptr;
5270 
5271 // Called from debugger. Prints method to the default file with the default phase name.
5272 // This works regardless of any Ideal Graph Visualizer flags set or not.
5273 // Use in debugger (gdb/rr): p igv_print($sp, $fp, $pc).
5274 void igv_print(void* sp, void* fp, void* pc) {
5275   frame fr(sp, fp, pc);
5276   Compile::current()->igv_print_method_to_file(nullptr, false, &fr);
5277 }
5278 
5279 // Same as igv_print() above but with a specified phase name.
5280 void igv_print(const char* phase_name, void* sp, void* fp, void* pc) {
5281   frame fr(sp, fp, pc);
5282   Compile::current()->igv_print_method_to_file(phase_name, false, &fr);
5283 }
5284 
5285 // Called from debugger. Prints method with the default phase name to the default network or the one specified with
5286 // the network flags for the Ideal Graph Visualizer, or to the default file depending on the 'network' argument.
5287 // This works regardless of any Ideal Graph Visualizer flags set or not.
5288 // Use in debugger (gdb/rr): p igv_print(true, $sp, $fp, $pc).
5289 void igv_print(bool network, void* sp, void* fp, void* pc) {
5290   frame fr(sp, fp, pc);
5291   if (network) {
5292     Compile::current()->igv_print_method_to_network(nullptr, &fr);
5293   } else {
5294     Compile::current()->igv_print_method_to_file(nullptr, false, &fr);
5295   }
5296 }
5297 
5298 // Same as igv_print(bool network, ...) above but with a specified phase name.
5299 // Use in debugger (gdb/rr): p igv_print(true, "MyPhase", $sp, $fp, $pc).
5300 void igv_print(bool network, const char* phase_name, void* sp, void* fp, void* pc) {
5301   frame fr(sp, fp, pc);
5302   if (network) {
5303     Compile::current()->igv_print_method_to_network(phase_name, &fr);
5304   } else {
5305     Compile::current()->igv_print_method_to_file(phase_name, false, &fr);
5306   }
5307 }
5308 
5309 // Called from debugger. Normal write to the default _printer. Only works if Ideal Graph Visualizer printing flags are set.
5310 void igv_print_default() {
5311   Compile::current()->print_method(PHASE_DEBUG, 0);
5312 }
5313 
5314 // Called from debugger, especially when replaying a trace in which the program state cannot be altered like with rr replay.
5315 // A method is appended to an existing default file with the default phase name. This means that igv_append() must follow
5316 // an earlier igv_print(*) call which sets up the file. This works regardless of any Ideal Graph Visualizer flags set or not.
5317 // Use in debugger (gdb/rr): p igv_append($sp, $fp, $pc).
5318 void igv_append(void* sp, void* fp, void* pc) {
5319   frame fr(sp, fp, pc);
5320   Compile::current()->igv_print_method_to_file(nullptr, true, &fr);
5321 }
5322 
5323 // Same as igv_append(...) above but with a specified phase name.
5324 // Use in debugger (gdb/rr): p igv_append("MyPhase", $sp, $fp, $pc).
5325 void igv_append(const char* phase_name, void* sp, void* fp, void* pc) {
5326   frame fr(sp, fp, pc);
5327   Compile::current()->igv_print_method_to_file(phase_name, true, &fr);
5328 }
5329 
5330 void Compile::igv_print_method_to_file(const char* phase_name, bool append, const frame* fr) {
5331   const char* file_name = "custom_debug.xml";
5332   if (_debug_file_printer == nullptr) {
5333     _debug_file_printer = new IdealGraphPrinter(C, file_name, append);
5334   } else {
5335     _debug_file_printer->update_compiled_method(C->method());
5336   }
5337   tty->print_cr("Method %s to %s", append ? "appended" : "printed", file_name);
5338   _debug_file_printer->print_graph(phase_name, fr);
5339 }
5340 
5341 void Compile::igv_print_method_to_network(const char* phase_name, const frame* fr) {
5342   ResourceMark rm;
5343   GrowableArray<const Node*> empty_list;
5344   igv_print_graph_to_network(phase_name, empty_list, fr);
5345 }
5346 
5347 void Compile::igv_print_graph_to_network(const char* name, GrowableArray<const Node*>& visible_nodes, const frame* fr) {
5348   if (_debug_network_printer == nullptr) {
5349     _debug_network_printer = new IdealGraphPrinter(C);
5350   } else {
5351     _debug_network_printer->update_compiled_method(C->method());
5352   }
5353   tty->print_cr("Method printed over network stream to IGV");
5354   _debug_network_printer->print(name, C->root(), visible_nodes, fr);
5355 }
5356 #endif // !PRODUCT
5357 
5358 Node* Compile::narrow_value(BasicType bt, Node* value, const Type* type, PhaseGVN* phase, bool transform_res) {
5359   precond(type != nullptr);
5360 
5361   if (phase->type(value)->higher_equal(type)) {
5362     return value;
5363   }
5364   Node* result = nullptr;
5365   if (bt == T_BYTE) {
5366     result = phase->transform(new LShiftINode(value, phase->intcon(24)));
5367     result = new RShiftINode(result, phase->intcon(24));
5368   } else if (bt == T_BOOLEAN) {
5369     assert(type == TypeInt::BOOL || type == TypeInt::UBYTE, "unexpected boolean type: %s", Type::str(type));
5370     Node* mask = phase->intcon(type == TypeInt::BOOL ? 1 : 0xFF);
5371     result = new AndINode(value, mask);
5372   } else if (bt == T_CHAR) {
5373     result = new AndINode(value,phase->intcon(0xFFFF));
5374   } else {
5375     assert(bt == T_SHORT, "unexpected narrow type");
5376     result = phase->transform(new LShiftINode(value, phase->intcon(16)));
5377     result = new RShiftINode(result, phase->intcon(16));
5378   }
5379   if (transform_res) {
5380     result = phase->transform(result);
5381   }
5382   return result;
5383 }
5384 
5385 void Compile::record_method_not_compilable_oom() {
5386   record_method_not_compilable(CompilationMemoryStatistic::failure_reason_memlimit());
5387 }
5388 
5389 #ifndef PRODUCT
5390 // Collects all the control inputs from nodes on the worklist and from their data dependencies
5391 static void find_candidate_control_inputs(Unique_Node_List& worklist, Unique_Node_List& candidates) {
5392   // Follow non-control edges until we reach CFG nodes
5393   for (uint i = 0; i < worklist.size(); i++) {
5394     const Node* n = worklist.at(i);
5395     for (uint j = 0; j < n->req(); j++) {
5396       Node* in = n->in(j);
5397       if (in == nullptr || in->is_Root()) {
5398         continue;
5399       }
5400       if (in->is_CFG()) {
5401         if (in->is_Call()) {
5402           // The return value of a call is only available if the call did not result in an exception
5403           Node* control_proj_use = in->as_Call()->proj_out(TypeFunc::Control)->unique_out();
5404           if (control_proj_use->is_Catch()) {
5405             Node* fall_through = control_proj_use->as_Catch()->proj_out(CatchProjNode::fall_through_index);
5406             candidates.push(fall_through);
5407             continue;
5408           }
5409         }
5410 
5411         if (in->is_Multi()) {
5412           // We got here by following data inputs so we should only have one control use
5413           // (no IfNode, etc)
5414           assert(!n->is_MultiBranch(), "unexpected node type: %s", n->Name());
5415           candidates.push(in->as_Multi()->proj_out(TypeFunc::Control));
5416         } else {
5417           candidates.push(in);
5418         }
5419       } else {
5420         worklist.push(in);
5421       }
5422     }
5423   }
5424 }
5425 
5426 // Returns the candidate node that is a descendant to all the other candidates
5427 static Node* pick_control(Unique_Node_List& candidates) {
5428   Unique_Node_List worklist;
5429   worklist.copy(candidates);
5430 
5431   // Traverse backwards through the CFG
5432   for (uint i = 0; i < worklist.size(); i++) {
5433     const Node* n = worklist.at(i);
5434     if (n->is_Root()) {
5435       continue;
5436     }
5437     for (uint j = 0; j < n->req(); j++) {
5438       // Skip backedge of loops to avoid cycles
5439       if (n->is_Loop() && j == LoopNode::LoopBackControl) {
5440         continue;
5441       }
5442 
5443       Node* pred = n->in(j);
5444       if (pred != nullptr && pred != n && pred->is_CFG()) {
5445         worklist.push(pred);
5446         // if pred is an ancestor of n, then pred is an ancestor to at least one candidate
5447         candidates.remove(pred);
5448       }
5449     }
5450   }
5451 
5452   assert(candidates.size() == 1, "unexpected control flow");
5453   return candidates.at(0);
5454 }
5455 
5456 // Initialize a parameter input for a debug print call, using a placeholder for jlong and jdouble
5457 static void debug_print_init_parm(Node* call, Node* parm, Node* half, int* pos) {
5458   call->init_req((*pos)++, parm);
5459   const BasicType bt = parm->bottom_type()->basic_type();
5460   if (bt == T_LONG || bt == T_DOUBLE) {
5461     call->init_req((*pos)++, half);
5462   }
5463 }
5464 
5465 Node* Compile::make_debug_print_call(const char* str, address call_addr, PhaseGVN* gvn,
5466                               Node* parm0, Node* parm1,
5467                               Node* parm2, Node* parm3,
5468                               Node* parm4, Node* parm5,
5469                               Node* parm6) const {
5470   Node* str_node = gvn->transform(new ConPNode(TypeRawPtr::make(((address) str))));
5471   const TypeFunc* type = OptoRuntime::debug_print_Type(parm0, parm1, parm2, parm3, parm4, parm5, parm6);
5472   Node* call = new CallLeafNode(type, call_addr, "debug_print", TypeRawPtr::BOTTOM);
5473 
5474   // find the most suitable control input
5475   Unique_Node_List worklist, candidates;
5476   if (parm0 != nullptr) { worklist.push(parm0);
5477   if (parm1 != nullptr) { worklist.push(parm1);
5478   if (parm2 != nullptr) { worklist.push(parm2);
5479   if (parm3 != nullptr) { worklist.push(parm3);
5480   if (parm4 != nullptr) { worklist.push(parm4);
5481   if (parm5 != nullptr) { worklist.push(parm5);
5482   if (parm6 != nullptr) { worklist.push(parm6);
5483   /* close each nested if ===> */  } } } } } } }
5484   find_candidate_control_inputs(worklist, candidates);
5485   Node* control = nullptr;
5486   if (candidates.size() == 0) {
5487     control = C->start()->proj_out(TypeFunc::Control);
5488   } else {
5489     control = pick_control(candidates);
5490   }
5491 
5492   // find all the previous users of the control we picked
5493   GrowableArray<Node*> users_of_control;
5494   for (DUIterator_Fast kmax, i = control->fast_outs(kmax); i < kmax; i++) {
5495     Node* use = control->fast_out(i);
5496     if (use->is_CFG() && use != control) {
5497       users_of_control.push(use);
5498     }
5499   }
5500 
5501   // we do not actually care about IO and memory as it uses neither
5502   call->init_req(TypeFunc::Control,   control);
5503   call->init_req(TypeFunc::I_O,       top());
5504   call->init_req(TypeFunc::Memory,    top());
5505   call->init_req(TypeFunc::FramePtr,  C->start()->proj_out(TypeFunc::FramePtr));
5506   call->init_req(TypeFunc::ReturnAdr, top());
5507 
5508   int pos = TypeFunc::Parms;
5509   call->init_req(pos++, str_node);
5510   if (parm0 != nullptr) { debug_print_init_parm(call, parm0, top(), &pos);
5511   if (parm1 != nullptr) { debug_print_init_parm(call, parm1, top(), &pos);
5512   if (parm2 != nullptr) { debug_print_init_parm(call, parm2, top(), &pos);
5513   if (parm3 != nullptr) { debug_print_init_parm(call, parm3, top(), &pos);
5514   if (parm4 != nullptr) { debug_print_init_parm(call, parm4, top(), &pos);
5515   if (parm5 != nullptr) { debug_print_init_parm(call, parm5, top(), &pos);
5516   if (parm6 != nullptr) { debug_print_init_parm(call, parm6, top(), &pos);
5517   /* close each nested if ===> */  } } } } } } }
5518   assert(call->in(call->req()-1) != nullptr, "must initialize all parms");
5519 
5520   call = gvn->transform(call);
5521   Node* call_control_proj = gvn->transform(new ProjNode(call, TypeFunc::Control));
5522 
5523   // rewire previous users to have the new call as control instead
5524   PhaseIterGVN* igvn = gvn->is_IterGVN();
5525   for (int i = 0; i < users_of_control.length(); i++) {
5526     Node* use = users_of_control.at(i);
5527     for (uint j = 0; j < use->req(); j++) {
5528       if (use->in(j) == control) {
5529         if (igvn != nullptr) {
5530           igvn->replace_input_of(use, j, call_control_proj);
5531         } else {
5532           gvn->hash_delete(use);
5533           use->set_req(j, call_control_proj);
5534           gvn->hash_insert(use);
5535         }
5536       }
5537     }
5538   }
5539 
5540   return call;
5541 }
5542 #endif // !PRODUCT