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