1 /*
   2  * Copyright (c) 1997, 2025, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "asm/macroAssembler.hpp"
  26 #include "asm/macroAssembler.inline.hpp"
  27 #include "ci/ciReplay.hpp"
  28 #include "classfile/javaClasses.hpp"
  29 #include "code/aotCodeCache.hpp"
  30 #include "code/exceptionHandlerTable.hpp"
  31 #include "code/nmethod.hpp"
  32 #include "compiler/compilationFailureInfo.hpp"
  33 #include "compiler/compilationMemoryStatistic.hpp"
  34 #include "compiler/compileBroker.hpp"
  35 #include "compiler/compileLog.hpp"
  36 #include "compiler/compiler_globals.hpp"
  37 #include "compiler/compilerDefinitions.hpp"
  38 #include "compiler/compilerOracle.hpp"
  39 #include "compiler/disassembler.hpp"
  40 #include "compiler/oopMap.hpp"
  41 #include "gc/shared/barrierSet.hpp"
  42 #include "gc/shared/c2/barrierSetC2.hpp"
  43 #include "jfr/jfrEvents.hpp"
  44 #include "jvm_io.h"
  45 #include "memory/allocation.hpp"
  46 #include "memory/arena.hpp"
  47 #include "memory/resourceArea.hpp"
  48 #include "opto/addnode.hpp"
  49 #include "opto/block.hpp"
  50 #include "opto/c2compiler.hpp"
  51 #include "opto/callGenerator.hpp"
  52 #include "opto/callnode.hpp"
  53 #include "opto/castnode.hpp"
  54 #include "opto/cfgnode.hpp"
  55 #include "opto/chaitin.hpp"
  56 #include "opto/compile.hpp"
  57 #include "opto/connode.hpp"
  58 #include "opto/convertnode.hpp"
  59 #include "opto/divnode.hpp"
  60 #include "opto/escape.hpp"
  61 #include "opto/idealGraphPrinter.hpp"
  62 #include "opto/locknode.hpp"
  63 #include "opto/loopnode.hpp"
  64 #include "opto/machnode.hpp"
  65 #include "opto/macro.hpp"
  66 #include "opto/matcher.hpp"
  67 #include "opto/mathexactnode.hpp"
  68 #include "opto/memnode.hpp"
  69 #include "opto/mulnode.hpp"
  70 #include "opto/narrowptrnode.hpp"
  71 #include "opto/node.hpp"
  72 #include "opto/opaquenode.hpp"
  73 #include "opto/opcodes.hpp"
  74 #include "opto/output.hpp"
  75 #include "opto/parse.hpp"
  76 #include "opto/phaseX.hpp"
  77 #include "opto/rootnode.hpp"
  78 #include "opto/runtime.hpp"
  79 #include "opto/stringopts.hpp"
  80 #include "opto/type.hpp"
  81 #include "opto/vector.hpp"
  82 #include "opto/vectornode.hpp"
  83 #include "runtime/globals_extension.hpp"
  84 #include "runtime/sharedRuntime.hpp"
  85 #include "runtime/signature.hpp"
  86 #include "runtime/stubRoutines.hpp"
  87 #include "runtime/timer.hpp"
  88 #include "utilities/align.hpp"
  89 #include "utilities/copy.hpp"
  90 #include "utilities/hashTable.hpp"
  91 #include "utilities/macros.hpp"
  92 
  93 // -------------------- Compile::mach_constant_base_node -----------------------
  94 // Constant table base node singleton.
  95 MachConstantBaseNode* Compile::mach_constant_base_node() {
  96   if (_mach_constant_base_node == nullptr) {
  97     _mach_constant_base_node = new MachConstantBaseNode();
  98     _mach_constant_base_node->add_req(C->root());
  99   }
 100   return _mach_constant_base_node;
 101 }
 102 
 103 
 104 /// Support for intrinsics.
 105 
 106 // Return the index at which m must be inserted (or already exists).
 107 // The sort order is by the address of the ciMethod, with is_virtual as minor key.
 108 class IntrinsicDescPair {
 109  private:
 110   ciMethod* _m;
 111   bool _is_virtual;
 112  public:
 113   IntrinsicDescPair(ciMethod* m, bool is_virtual) : _m(m), _is_virtual(is_virtual) {}
 114   static int compare(IntrinsicDescPair* const& key, CallGenerator* const& elt) {
 115     ciMethod* m= elt->method();
 116     ciMethod* key_m = key->_m;
 117     if (key_m < m)      return -1;
 118     else if (key_m > m) return 1;
 119     else {
 120       bool is_virtual = elt->is_virtual();
 121       bool key_virtual = key->_is_virtual;
 122       if (key_virtual < is_virtual)      return -1;
 123       else if (key_virtual > is_virtual) return 1;
 124       else                               return 0;
 125     }
 126   }
 127 };
 128 int Compile::intrinsic_insertion_index(ciMethod* m, bool is_virtual, bool& found) {
 129 #ifdef ASSERT
 130   for (int i = 1; i < _intrinsics.length(); i++) {
 131     CallGenerator* cg1 = _intrinsics.at(i-1);
 132     CallGenerator* cg2 = _intrinsics.at(i);
 133     assert(cg1->method() != cg2->method()
 134            ? cg1->method()     < cg2->method()
 135            : cg1->is_virtual() < cg2->is_virtual(),
 136            "compiler intrinsics list must stay sorted");
 137   }
 138 #endif
 139   IntrinsicDescPair pair(m, is_virtual);
 140   return _intrinsics.find_sorted<IntrinsicDescPair*, IntrinsicDescPair::compare>(&pair, found);
 141 }
 142 
 143 void Compile::register_intrinsic(CallGenerator* cg) {
 144   bool found = false;
 145   int index = intrinsic_insertion_index(cg->method(), cg->is_virtual(), found);
 146   assert(!found, "registering twice");
 147   _intrinsics.insert_before(index, cg);
 148   assert(find_intrinsic(cg->method(), cg->is_virtual()) == cg, "registration worked");
 149 }
 150 
 151 CallGenerator* Compile::find_intrinsic(ciMethod* m, bool is_virtual) {
 152   assert(m->is_loaded(), "don't try this on unloaded methods");
 153   if (_intrinsics.length() > 0) {
 154     bool found = false;
 155     int index = intrinsic_insertion_index(m, is_virtual, found);
 156      if (found) {
 157       return _intrinsics.at(index);
 158     }
 159   }
 160   // Lazily create intrinsics for intrinsic IDs well-known in the runtime.
 161   if (m->intrinsic_id() != vmIntrinsics::_none &&
 162       m->intrinsic_id() <= vmIntrinsics::LAST_COMPILER_INLINE) {
 163     CallGenerator* cg = make_vm_intrinsic(m, is_virtual);
 164     if (cg != nullptr) {
 165       // Save it for next time:
 166       register_intrinsic(cg);
 167       return cg;
 168     } else {
 169       gather_intrinsic_statistics(m->intrinsic_id(), is_virtual, _intrinsic_disabled);
 170     }
 171   }
 172   return nullptr;
 173 }
 174 
 175 // Compile::make_vm_intrinsic is defined in library_call.cpp.
 176 
 177 #ifndef PRODUCT
 178 // statistics gathering...
 179 
 180 juint  Compile::_intrinsic_hist_count[vmIntrinsics::number_of_intrinsics()] = {0};
 181 jubyte Compile::_intrinsic_hist_flags[vmIntrinsics::number_of_intrinsics()] = {0};
 182 
 183 inline int as_int(vmIntrinsics::ID id) {
 184   return vmIntrinsics::as_int(id);
 185 }
 186 
 187 bool Compile::gather_intrinsic_statistics(vmIntrinsics::ID id, bool is_virtual, int flags) {
 188   assert(id > vmIntrinsics::_none && id < vmIntrinsics::ID_LIMIT, "oob");
 189   int oflags = _intrinsic_hist_flags[as_int(id)];
 190   assert(flags != 0, "what happened?");
 191   if (is_virtual) {
 192     flags |= _intrinsic_virtual;
 193   }
 194   bool changed = (flags != oflags);
 195   if ((flags & _intrinsic_worked) != 0) {
 196     juint count = (_intrinsic_hist_count[as_int(id)] += 1);
 197     if (count == 1) {
 198       changed = true;           // first time
 199     }
 200     // increment the overall count also:
 201     _intrinsic_hist_count[as_int(vmIntrinsics::_none)] += 1;
 202   }
 203   if (changed) {
 204     if (((oflags ^ flags) & _intrinsic_virtual) != 0) {
 205       // Something changed about the intrinsic's virtuality.
 206       if ((flags & _intrinsic_virtual) != 0) {
 207         // This is the first use of this intrinsic as a virtual call.
 208         if (oflags != 0) {
 209           // We already saw it as a non-virtual, so note both cases.
 210           flags |= _intrinsic_both;
 211         }
 212       } else if ((oflags & _intrinsic_both) == 0) {
 213         // This is the first use of this intrinsic as a non-virtual
 214         flags |= _intrinsic_both;
 215       }
 216     }
 217     _intrinsic_hist_flags[as_int(id)] = (jubyte) (oflags | flags);
 218   }
 219   // update the overall flags also:
 220   _intrinsic_hist_flags[as_int(vmIntrinsics::_none)] |= (jubyte) flags;
 221   return changed;
 222 }
 223 
 224 static char* format_flags(int flags, char* buf) {
 225   buf[0] = 0;
 226   if ((flags & Compile::_intrinsic_worked) != 0)    strcat(buf, ",worked");
 227   if ((flags & Compile::_intrinsic_failed) != 0)    strcat(buf, ",failed");
 228   if ((flags & Compile::_intrinsic_disabled) != 0)  strcat(buf, ",disabled");
 229   if ((flags & Compile::_intrinsic_virtual) != 0)   strcat(buf, ",virtual");
 230   if ((flags & Compile::_intrinsic_both) != 0)      strcat(buf, ",nonvirtual");
 231   if (buf[0] == 0)  strcat(buf, ",");
 232   assert(buf[0] == ',', "must be");
 233   return &buf[1];
 234 }
 235 
 236 void Compile::print_intrinsic_statistics() {
 237   char flagsbuf[100];
 238   ttyLocker ttyl;
 239   if (xtty != nullptr)  xtty->head("statistics type='intrinsic'");
 240   tty->print_cr("Compiler intrinsic usage:");
 241   juint total = _intrinsic_hist_count[as_int(vmIntrinsics::_none)];
 242   if (total == 0)  total = 1;  // avoid div0 in case of no successes
 243   #define PRINT_STAT_LINE(name, c, f) \
 244     tty->print_cr("  %4d (%4.1f%%) %s (%s)", (int)(c), ((c) * 100.0) / total, name, f);
 245   for (auto id : EnumRange<vmIntrinsicID>{}) {
 246     int   flags = _intrinsic_hist_flags[as_int(id)];
 247     juint count = _intrinsic_hist_count[as_int(id)];
 248     if ((flags | count) != 0) {
 249       PRINT_STAT_LINE(vmIntrinsics::name_at(id), count, format_flags(flags, flagsbuf));
 250     }
 251   }
 252   PRINT_STAT_LINE("total", total, format_flags(_intrinsic_hist_flags[as_int(vmIntrinsics::_none)], flagsbuf));
 253   if (xtty != nullptr)  xtty->tail("statistics");
 254 }
 255 
 256 void Compile::print_statistics() {
 257   { ttyLocker ttyl;
 258     if (xtty != nullptr)  xtty->head("statistics type='opto'");
 259     Parse::print_statistics();
 260     PhaseStringOpts::print_statistics();
 261     PhaseCCP::print_statistics();
 262     PhaseRegAlloc::print_statistics();
 263     PhaseOutput::print_statistics();
 264     PhasePeephole::print_statistics();
 265     PhaseIdealLoop::print_statistics();
 266     ConnectionGraph::print_statistics();
 267     PhaseMacroExpand::print_statistics();
 268     if (xtty != nullptr)  xtty->tail("statistics");
 269   }
 270   if (_intrinsic_hist_flags[as_int(vmIntrinsics::_none)] != 0) {
 271     // put this under its own <statistics> element.
 272     print_intrinsic_statistics();
 273   }
 274 }
 275 #endif //PRODUCT
 276 
 277 void Compile::gvn_replace_by(Node* n, Node* nn) {
 278   for (DUIterator_Last imin, i = n->last_outs(imin); i >= imin; ) {
 279     Node* use = n->last_out(i);
 280     bool is_in_table = initial_gvn()->hash_delete(use);
 281     uint uses_found = 0;
 282     for (uint j = 0; j < use->len(); j++) {
 283       if (use->in(j) == n) {
 284         if (j < use->req())
 285           use->set_req(j, nn);
 286         else
 287           use->set_prec(j, nn);
 288         uses_found++;
 289       }
 290     }
 291     if (is_in_table) {
 292       // reinsert into table
 293       initial_gvn()->hash_find_insert(use);
 294     }
 295     record_for_igvn(use);
 296     PhaseIterGVN::add_users_of_use_to_worklist(nn, use, *_igvn_worklist);
 297     i -= uses_found;    // we deleted 1 or more copies of this edge
 298   }
 299 }
 300 
 301 
 302 // Identify all nodes that are reachable from below, useful.
 303 // Use breadth-first pass that records state in a Unique_Node_List,
 304 // recursive traversal is slower.
 305 void Compile::identify_useful_nodes(Unique_Node_List &useful) {
 306   int estimated_worklist_size = live_nodes();
 307   useful.map( estimated_worklist_size, nullptr );  // preallocate space
 308 
 309   // Initialize worklist
 310   if (root() != nullptr)  { useful.push(root()); }
 311   // If 'top' is cached, declare it useful to preserve cached node
 312   if (cached_top_node())  { useful.push(cached_top_node()); }
 313 
 314   // Push all useful nodes onto the list, breadthfirst
 315   for( uint next = 0; next < useful.size(); ++next ) {
 316     assert( next < unique(), "Unique useful nodes < total nodes");
 317     Node *n  = useful.at(next);
 318     uint max = n->len();
 319     for( uint i = 0; i < max; ++i ) {
 320       Node *m = n->in(i);
 321       if (not_a_node(m))  continue;
 322       useful.push(m);
 323     }
 324   }
 325 }
 326 
 327 // Update dead_node_list with any missing dead nodes using useful
 328 // list. Consider all non-useful nodes to be useless i.e., dead nodes.
 329 void Compile::update_dead_node_list(Unique_Node_List &useful) {
 330   uint max_idx = unique();
 331   VectorSet& useful_node_set = useful.member_set();
 332 
 333   for (uint node_idx = 0; node_idx < max_idx; node_idx++) {
 334     // If node with index node_idx is not in useful set,
 335     // mark it as dead in dead node list.
 336     if (!useful_node_set.test(node_idx)) {
 337       record_dead_node(node_idx);
 338     }
 339   }
 340 }
 341 
 342 void Compile::remove_useless_late_inlines(GrowableArray<CallGenerator*>* inlines, Unique_Node_List &useful) {
 343   int shift = 0;
 344   for (int i = 0; i < inlines->length(); i++) {
 345     CallGenerator* cg = inlines->at(i);
 346     if (useful.member(cg->call_node())) {
 347       if (shift > 0) {
 348         inlines->at_put(i - shift, cg);
 349       }
 350     } else {
 351       shift++; // skip over the dead element
 352     }
 353   }
 354   if (shift > 0) {
 355     inlines->trunc_to(inlines->length() - shift); // remove last elements from compacted array
 356   }
 357 }
 358 
 359 void Compile::remove_useless_late_inlines(GrowableArray<CallGenerator*>* inlines, Node* dead) {
 360   assert(dead != nullptr && dead->is_Call(), "sanity");
 361   int found = 0;
 362   for (int i = 0; i < inlines->length(); i++) {
 363     if (inlines->at(i)->call_node() == dead) {
 364       inlines->remove_at(i);
 365       found++;
 366       NOT_DEBUG( break; ) // elements are unique, so exit early
 367     }
 368   }
 369   assert(found <= 1, "not unique");
 370 }
 371 
 372 template<typename N, ENABLE_IF_SDEFN(std::is_base_of<Node, N>::value)>
 373 void Compile::remove_useless_nodes(GrowableArray<N*>& node_list, Unique_Node_List& useful) {
 374   for (int i = node_list.length() - 1; i >= 0; i--) {
 375     N* node = node_list.at(i);
 376     if (!useful.member(node)) {
 377       node_list.delete_at(i); // replaces i-th with last element which is known to be useful (already processed)
 378     }
 379   }
 380 }
 381 
 382 void Compile::remove_useless_node(Node* dead) {
 383   remove_modified_node(dead);
 384 
 385   // Constant node that has no out-edges and has only one in-edge from
 386   // root is usually dead. However, sometimes reshaping walk makes
 387   // it reachable by adding use edges. So, we will NOT count Con nodes
 388   // as dead to be conservative about the dead node count at any
 389   // given time.
 390   if (!dead->is_Con()) {
 391     record_dead_node(dead->_idx);
 392   }
 393   if (dead->is_macro()) {
 394     remove_macro_node(dead);
 395   }
 396   if (dead->is_expensive()) {
 397     remove_expensive_node(dead);
 398   }
 399   if (dead->is_OpaqueTemplateAssertionPredicate()) {
 400     remove_template_assertion_predicate_opaque(dead->as_OpaqueTemplateAssertionPredicate());
 401   }
 402   if (dead->is_ParsePredicate()) {
 403     remove_parse_predicate(dead->as_ParsePredicate());
 404   }
 405   if (dead->for_post_loop_opts_igvn()) {
 406     remove_from_post_loop_opts_igvn(dead);
 407   }
 408   if (dead->for_merge_stores_igvn()) {
 409     remove_from_merge_stores_igvn(dead);
 410   }
 411   if (dead->is_Call()) {
 412     remove_useless_late_inlines(                &_late_inlines, dead);
 413     remove_useless_late_inlines(         &_string_late_inlines, dead);
 414     remove_useless_late_inlines(         &_boxing_late_inlines, dead);
 415     remove_useless_late_inlines(&_vector_reboxing_late_inlines, dead);
 416 
 417     if (dead->is_CallStaticJava()) {
 418       remove_unstable_if_trap(dead->as_CallStaticJava(), false);
 419     }
 420   }
 421 }
 422 
 423 // Disconnect all useless nodes by disconnecting those at the boundary.
 424 void Compile::disconnect_useless_nodes(Unique_Node_List& useful, Unique_Node_List& worklist, const Unique_Node_List* root_and_safepoints) {
 425   uint next = 0;
 426   while (next < useful.size()) {
 427     Node *n = useful.at(next++);
 428     if (n->is_SafePoint()) {
 429       // We're done with a parsing phase. Replaced nodes are not valid
 430       // beyond that point.
 431       n->as_SafePoint()->delete_replaced_nodes();
 432     }
 433     // Use raw traversal of out edges since this code removes out edges
 434     int max = n->outcnt();
 435     for (int j = 0; j < max; ++j) {
 436       Node* child = n->raw_out(j);
 437       if (!useful.member(child)) {
 438         assert(!child->is_top() || child != top(),
 439                "If top is cached in Compile object it is in useful list");
 440         // Only need to remove this out-edge to the useless node
 441         n->raw_del_out(j);
 442         --j;
 443         --max;
 444         if (child->is_data_proj_of_pure_function(n)) {
 445           worklist.push(n);
 446         }
 447       }
 448     }
 449     if (n->outcnt() == 1 && n->has_special_unique_user()) {
 450       assert(useful.member(n->unique_out()), "do not push a useless node");
 451       worklist.push(n->unique_out());
 452     }
 453   }
 454 
 455   remove_useless_nodes(_macro_nodes,        useful); // remove useless macro nodes
 456   remove_useless_nodes(_parse_predicates,   useful); // remove useless Parse Predicate nodes
 457   // Remove useless Template Assertion Predicate opaque nodes
 458   remove_useless_nodes(_template_assertion_predicate_opaques, useful);
 459   remove_useless_nodes(_expensive_nodes,    useful); // remove useless expensive nodes
 460   remove_useless_nodes(_for_post_loop_igvn, useful); // remove useless node recorded for post loop opts IGVN pass
 461   remove_useless_nodes(_for_merge_stores_igvn, useful); // remove useless node recorded for merge stores IGVN pass
 462   remove_useless_unstable_if_traps(useful);          // remove useless unstable_if traps
 463   remove_useless_coarsened_locks(useful);            // remove useless coarsened locks nodes
 464 #ifdef ASSERT
 465   if (_modified_nodes != nullptr) {
 466     _modified_nodes->remove_useless_nodes(useful.member_set());
 467   }
 468 #endif
 469 
 470   // clean up the late inline lists
 471   remove_useless_late_inlines(                &_late_inlines, useful);
 472   remove_useless_late_inlines(         &_string_late_inlines, useful);
 473   remove_useless_late_inlines(         &_boxing_late_inlines, useful);
 474   remove_useless_late_inlines(&_vector_reboxing_late_inlines, useful);
 475   DEBUG_ONLY(verify_graph_edges(true /*check for no_dead_code*/, root_and_safepoints);)
 476 }
 477 
 478 // ============================================================================
 479 //------------------------------CompileWrapper---------------------------------
 480 class CompileWrapper : public StackObj {
 481   Compile *const _compile;
 482  public:
 483   CompileWrapper(Compile* compile);
 484 
 485   ~CompileWrapper();
 486 };
 487 
 488 CompileWrapper::CompileWrapper(Compile* compile) : _compile(compile) {
 489   // the Compile* pointer is stored in the current ciEnv:
 490   ciEnv* env = compile->env();
 491   assert(env == ciEnv::current(), "must already be a ciEnv active");
 492   assert(env->compiler_data() == nullptr, "compile already active?");
 493   env->set_compiler_data(compile);
 494   assert(compile == Compile::current(), "sanity");
 495 
 496   compile->set_type_dict(nullptr);
 497   compile->set_clone_map(new Dict(cmpkey, hashkey, _compile->comp_arena()));
 498   compile->clone_map().set_clone_idx(0);
 499   compile->set_type_last_size(0);
 500   compile->set_last_tf(nullptr, nullptr);
 501   compile->set_indexSet_arena(nullptr);
 502   compile->set_indexSet_free_block_list(nullptr);
 503   compile->init_type_arena();
 504   Type::Initialize(compile);
 505   _compile->begin_method();
 506   _compile->clone_map().set_debug(_compile->has_method() && _compile->directive()->CloneMapDebugOption);
 507 }
 508 CompileWrapper::~CompileWrapper() {
 509   // simulate crash during compilation
 510   assert(CICrashAt < 0 || _compile->compile_id() != CICrashAt, "just as planned");
 511 
 512   _compile->end_method();
 513   _compile->env()->set_compiler_data(nullptr);
 514 }
 515 
 516 
 517 //----------------------------print_compile_messages---------------------------
 518 void Compile::print_compile_messages() {
 519 #ifndef PRODUCT
 520   // Check if recompiling
 521   if (!subsume_loads() && PrintOpto) {
 522     // Recompiling without allowing machine instructions to subsume loads
 523     tty->print_cr("*********************************************************");
 524     tty->print_cr("** Bailout: Recompile without subsuming loads          **");
 525     tty->print_cr("*********************************************************");
 526   }
 527   if ((do_escape_analysis() != DoEscapeAnalysis) && PrintOpto) {
 528     // Recompiling without escape analysis
 529     tty->print_cr("*********************************************************");
 530     tty->print_cr("** Bailout: Recompile without escape analysis          **");
 531     tty->print_cr("*********************************************************");
 532   }
 533   if (do_iterative_escape_analysis() != DoEscapeAnalysis && PrintOpto) {
 534     // Recompiling without iterative escape analysis
 535     tty->print_cr("*********************************************************");
 536     tty->print_cr("** Bailout: Recompile without iterative escape analysis**");
 537     tty->print_cr("*********************************************************");
 538   }
 539   if (do_reduce_allocation_merges() != ReduceAllocationMerges && PrintOpto) {
 540     // Recompiling without reducing allocation merges
 541     tty->print_cr("*********************************************************");
 542     tty->print_cr("** Bailout: Recompile without reduce allocation merges **");
 543     tty->print_cr("*********************************************************");
 544   }
 545   if ((eliminate_boxing() != EliminateAutoBox) && PrintOpto) {
 546     // Recompiling without boxing elimination
 547     tty->print_cr("*********************************************************");
 548     tty->print_cr("** Bailout: Recompile without boxing elimination       **");
 549     tty->print_cr("*********************************************************");
 550   }
 551   if ((do_locks_coarsening() != EliminateLocks) && PrintOpto) {
 552     // Recompiling without locks coarsening
 553     tty->print_cr("*********************************************************");
 554     tty->print_cr("** Bailout: Recompile without locks coarsening         **");
 555     tty->print_cr("*********************************************************");
 556   }
 557   if (env()->break_at_compile()) {
 558     // Open the debugger when compiling this method.
 559     tty->print("### Breaking when compiling: ");
 560     method()->print_short_name();
 561     tty->cr();
 562     BREAKPOINT;
 563   }
 564 
 565   if( PrintOpto ) {
 566     if (is_osr_compilation()) {
 567       tty->print("[OSR]%3d", _compile_id);
 568     } else {
 569       tty->print("%3d", _compile_id);
 570     }
 571   }
 572 #endif
 573 }
 574 
 575 #ifndef PRODUCT
 576 void Compile::print_phase(const char* phase_name) {
 577   tty->print_cr("%u.\t%s", ++_phase_counter, phase_name);
 578 }
 579 
 580 void Compile::print_ideal_ir(const char* phase_name) {
 581   // keep the following output all in one block
 582   // This output goes directly to the tty, not the compiler log.
 583   // To enable tools to match it up with the compilation activity,
 584   // be sure to tag this tty output with the compile ID.
 585 
 586   // Node dumping can cause a safepoint, which can break the tty lock.
 587   // Buffer all node dumps, so that all safepoints happen before we lock.
 588   ResourceMark rm;
 589   stringStream ss;
 590 
 591   if (_output == nullptr) {
 592     ss.print_cr("AFTER: %s", phase_name);
 593     // Print out all nodes in ascending order of index.
 594     root()->dump_bfs(MaxNodeLimit, nullptr, "+S$", &ss);
 595   } else {
 596     // Dump the node blockwise if we have a scheduling
 597     _output->print_scheduling(&ss);
 598   }
 599 
 600   // Check that the lock is not broken by a safepoint.
 601   NoSafepointVerifier nsv;
 602   ttyLocker ttyl;
 603   if (xtty != nullptr) {
 604     xtty->head("ideal compile_id='%d'%s compile_phase='%s'",
 605                compile_id(),
 606                is_osr_compilation() ? " compile_kind='osr'" : "",
 607                phase_name);
 608   }
 609 
 610   tty->print("%s", ss.as_string());
 611 
 612   if (xtty != nullptr) {
 613     xtty->tail("ideal");
 614   }
 615 }
 616 #endif
 617 
 618 // ============================================================================
 619 //------------------------------Compile standard-------------------------------
 620 
 621 // Compile a method.  entry_bci is -1 for normal compilations and indicates
 622 // the continuation bci for on stack replacement.
 623 
 624 
 625 Compile::Compile(ciEnv* ci_env, ciMethod* target, int osr_bci,
 626                  Options options, DirectiveSet* directive)
 627     : Phase(Compiler),
 628       _compile_id(ci_env->compile_id()),
 629       _options(options),
 630       _method(target),
 631       _entry_bci(osr_bci),
 632       _ilt(nullptr),
 633       _stub_function(nullptr),
 634       _stub_name(nullptr),
 635       _stub_id(StubId::NO_STUBID),
 636       _stub_entry_point(nullptr),
 637       _max_node_limit(MaxNodeLimit),
 638       _post_loop_opts_phase(false),
 639       _merge_stores_phase(false),
 640       _allow_macro_nodes(true),
 641       _inlining_progress(false),
 642       _inlining_incrementally(false),
 643       _do_cleanup(false),
 644       _has_reserved_stack_access(target->has_reserved_stack_access()),
 645 #ifndef PRODUCT
 646       _igv_idx(0),
 647       _trace_opto_output(directive->TraceOptoOutputOption),
 648 #endif
 649       _clinit_barrier_on_entry(false),
 650       _stress_seed(0),
 651       _comp_arena(mtCompiler, Arena::Tag::tag_comp),
 652       _barrier_set_state(BarrierSet::barrier_set()->barrier_set_c2()->create_barrier_state(comp_arena())),
 653       _env(ci_env),
 654       _directive(directive),
 655       _log(ci_env->log()),
 656       _first_failure_details(nullptr),
 657       _intrinsics(comp_arena(), 0, 0, nullptr),
 658       _macro_nodes(comp_arena(), 8, 0, nullptr),
 659       _parse_predicates(comp_arena(), 8, 0, nullptr),
 660       _template_assertion_predicate_opaques(comp_arena(), 8, 0, nullptr),
 661       _expensive_nodes(comp_arena(), 8, 0, nullptr),
 662       _for_post_loop_igvn(comp_arena(), 8, 0, nullptr),
 663       _for_merge_stores_igvn(comp_arena(), 8, 0, nullptr),
 664       _unstable_if_traps(comp_arena(), 8, 0, nullptr),
 665       _coarsened_locks(comp_arena(), 8, 0, nullptr),
 666       _congraph(nullptr),
 667       NOT_PRODUCT(_igv_printer(nullptr) COMMA)
 668           _unique(0),
 669       _dead_node_count(0),
 670       _dead_node_list(comp_arena()),
 671       _node_arena_one(mtCompiler, Arena::Tag::tag_node),
 672       _node_arena_two(mtCompiler, Arena::Tag::tag_node),
 673       _node_arena(&_node_arena_one),
 674       _mach_constant_base_node(nullptr),
 675       _Compile_types(mtCompiler, Arena::Tag::tag_type),
 676       _initial_gvn(nullptr),
 677       _igvn_worklist(nullptr),
 678       _types(nullptr),
 679       _node_hash(nullptr),
 680       _late_inlines(comp_arena(), 2, 0, nullptr),
 681       _string_late_inlines(comp_arena(), 2, 0, nullptr),
 682       _boxing_late_inlines(comp_arena(), 2, 0, nullptr),
 683       _vector_reboxing_late_inlines(comp_arena(), 2, 0, nullptr),
 684       _late_inlines_pos(0),
 685       _has_mh_late_inlines(false),
 686       _oom(false),
 687       _replay_inline_data(nullptr),
 688       _inline_printer(this),
 689       _java_calls(0),
 690       _inner_loops(0),
 691       _FIRST_STACK_mask(comp_arena()),
 692       _interpreter_frame_size(0),
 693       _regmask_arena(mtCompiler, Arena::Tag::tag_regmask),
 694       _output(nullptr)
 695 #ifndef PRODUCT
 696       ,
 697       _in_dump_cnt(0)
 698 #endif
 699 {
 700   C = this;
 701   CompileWrapper cw(this);
 702 
 703   TraceTime t1("Total compilation time", &_t_totalCompilation, CITime, CITimeVerbose);
 704   TraceTime t2(nullptr, &_t_methodCompilation, CITime, false);
 705 
 706 #if defined(SUPPORT_ASSEMBLY) || defined(SUPPORT_ABSTRACT_ASSEMBLY)
 707   bool print_opto_assembly = directive->PrintOptoAssemblyOption;
 708   // We can always print a disassembly, either abstract (hex dump) or
 709   // with the help of a suitable hsdis library. Thus, we should not
 710   // couple print_assembly and print_opto_assembly controls.
 711   // But: always print opto and regular assembly on compile command 'print'.
 712   bool print_assembly = directive->PrintAssemblyOption;
 713   set_print_assembly(print_opto_assembly || print_assembly);
 714 #else
 715   set_print_assembly(false); // must initialize.
 716 #endif
 717 
 718 #ifndef PRODUCT
 719   set_parsed_irreducible_loop(false);
 720 #endif
 721 
 722   if (directive->ReplayInlineOption) {
 723     _replay_inline_data = ciReplay::load_inline_data(method(), entry_bci(), ci_env->comp_level());
 724   }
 725   set_print_inlining(directive->PrintInliningOption || PrintOptoInlining);
 726   set_print_intrinsics(directive->PrintIntrinsicsOption);
 727   set_has_irreducible_loop(true); // conservative until build_loop_tree() reset it
 728 
 729   if (ProfileTraps) {
 730     // Make sure the method being compiled gets its own MDO,
 731     // so we can at least track the decompile_count().
 732     method()->ensure_method_data();
 733   }
 734 
 735   if (StressLCM || StressGCM || StressIGVN || StressCCP ||
 736       StressIncrementalInlining || StressMacroExpansion ||
 737       StressMacroElimination || StressUnstableIfTraps ||
 738       StressBailout || StressLoopPeeling) {
 739     initialize_stress_seed(directive);
 740   }
 741 
 742   Init(/*do_aliasing=*/ true);
 743 
 744   print_compile_messages();
 745 
 746   _ilt = InlineTree::build_inline_tree_root();
 747 
 748   // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
 749   assert(num_alias_types() >= AliasIdxRaw, "");
 750 
 751 #define MINIMUM_NODE_HASH  1023
 752 
 753   // GVN that will be run immediately on new nodes
 754   uint estimated_size = method()->code_size()*4+64;
 755   estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
 756   _igvn_worklist = new (comp_arena()) Unique_Node_List(comp_arena());
 757   _types = new (comp_arena()) Type_Array(comp_arena());
 758   _node_hash = new (comp_arena()) NodeHash(comp_arena(), estimated_size);
 759   PhaseGVN gvn;
 760   set_initial_gvn(&gvn);
 761 
 762   { // Scope for timing the parser
 763     TracePhase tp(_t_parser);
 764 
 765     // Put top into the hash table ASAP.
 766     initial_gvn()->transform(top());
 767 
 768     // Set up tf(), start(), and find a CallGenerator.
 769     CallGenerator* cg = nullptr;
 770     if (is_osr_compilation()) {
 771       const TypeTuple *domain = StartOSRNode::osr_domain();
 772       const TypeTuple *range = TypeTuple::make_range(method()->signature());
 773       init_tf(TypeFunc::make(domain, range));
 774       StartNode* s = new StartOSRNode(root(), domain);
 775       initial_gvn()->set_type_bottom(s);
 776       verify_start(s);
 777       cg = CallGenerator::for_osr(method(), entry_bci());
 778     } else {
 779       // Normal case.
 780       init_tf(TypeFunc::make(method()));
 781       StartNode* s = new StartNode(root(), tf()->domain());
 782       initial_gvn()->set_type_bottom(s);
 783       verify_start(s);
 784       float past_uses = method()->interpreter_invocation_count();
 785       float expected_uses = past_uses;
 786       cg = CallGenerator::for_inline(method(), expected_uses);
 787     }
 788     if (failing())  return;
 789     if (cg == nullptr) {
 790       const char* reason = InlineTree::check_can_parse(method());
 791       assert(reason != nullptr, "expect reason for parse failure");
 792       stringStream ss;
 793       ss.print("cannot parse method: %s", reason);
 794       record_method_not_compilable(ss.as_string());
 795       return;
 796     }
 797 
 798     gvn.set_type(root(), root()->bottom_type());
 799 
 800     JVMState* jvms = build_start_state(start(), tf());
 801     if ((jvms = cg->generate(jvms)) == nullptr) {
 802       assert(failure_reason() != nullptr, "expect reason for parse failure");
 803       stringStream ss;
 804       ss.print("method parse failed: %s", failure_reason());
 805       record_method_not_compilable(ss.as_string() DEBUG_ONLY(COMMA true));
 806       return;
 807     }
 808     GraphKit kit(jvms);
 809 
 810     if (!kit.stopped()) {
 811       // Accept return values, and transfer control we know not where.
 812       // This is done by a special, unique ReturnNode bound to root.
 813       return_values(kit.jvms());
 814     }
 815 
 816     if (kit.has_exceptions()) {
 817       // Any exceptions that escape from this call must be rethrown
 818       // to whatever caller is dynamically above us on the stack.
 819       // This is done by a special, unique RethrowNode bound to root.
 820       rethrow_exceptions(kit.transfer_exceptions_into_jvms());
 821     }
 822 
 823     assert(IncrementalInline || (_late_inlines.length() == 0 && !has_mh_late_inlines()), "incremental inlining is off");
 824 
 825     if (_late_inlines.length() == 0 && !has_mh_late_inlines() && !failing() && has_stringbuilder()) {
 826       inline_string_calls(true);
 827     }
 828 
 829     if (failing())  return;
 830 
 831     // Remove clutter produced by parsing.
 832     if (!failing()) {
 833       ResourceMark rm;
 834       PhaseRemoveUseless pru(initial_gvn(), *igvn_worklist());
 835     }
 836   }
 837 
 838   // Note:  Large methods are capped off in do_one_bytecode().
 839   if (failing())  return;
 840 
 841   // After parsing, node notes are no longer automagic.
 842   // They must be propagated by register_new_node_with_optimizer(),
 843   // clone(), or the like.
 844   set_default_node_notes(nullptr);
 845 
 846 #ifndef PRODUCT
 847   if (should_print_igv(1)) {
 848     _igv_printer->print_inlining();
 849   }
 850 #endif
 851 
 852   if (failing())  return;
 853   NOT_PRODUCT( verify_graph_edges(); )
 854 
 855   // Now optimize
 856   Optimize();
 857   if (failing())  return;
 858   NOT_PRODUCT( verify_graph_edges(); )
 859 
 860 #ifndef PRODUCT
 861   if (should_print_ideal()) {
 862     print_ideal_ir("print_ideal");
 863   }
 864 #endif
 865 
 866 #ifdef ASSERT
 867   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 868   bs->verify_gc_barriers(this, BarrierSetC2::BeforeCodeGen);
 869 #endif
 870 
 871   // Dump compilation data to replay it.
 872   if (directive->DumpReplayOption) {
 873     env()->dump_replay_data(_compile_id);
 874   }
 875   if (directive->DumpInlineOption && (ilt() != nullptr)) {
 876     env()->dump_inline_data(_compile_id);
 877   }
 878 
 879   // Now that we know the size of all the monitors we can add a fixed slot
 880   // for the original deopt pc.
 881   int next_slot = fixed_slots() + (sizeof(address) / VMRegImpl::stack_slot_size);
 882   set_fixed_slots(next_slot);
 883 
 884   // Compute when to use implicit null checks. Used by matching trap based
 885   // nodes and NullCheck optimization.
 886   set_allowed_deopt_reasons();
 887 
 888   // Now generate code
 889   Code_Gen();
 890 }
 891 
 892 //------------------------------Compile----------------------------------------
 893 // Compile a runtime stub
 894 Compile::Compile(ciEnv* ci_env,
 895                  TypeFunc_generator generator,
 896                  address stub_function,
 897                  const char* stub_name,
 898                  StubId stub_id,
 899                  int is_fancy_jump,
 900                  bool pass_tls,
 901                  bool return_pc,
 902                  DirectiveSet* directive)
 903     : Phase(Compiler),
 904       _compile_id(0),
 905       _options(Options::for_runtime_stub()),
 906       _method(nullptr),
 907       _entry_bci(InvocationEntryBci),
 908       _stub_function(stub_function),
 909       _stub_name(stub_name),
 910       _stub_id(stub_id),
 911       _stub_entry_point(nullptr),
 912       _max_node_limit(MaxNodeLimit),
 913       _post_loop_opts_phase(false),
 914       _merge_stores_phase(false),
 915       _allow_macro_nodes(true),
 916       _inlining_progress(false),
 917       _inlining_incrementally(false),
 918       _has_reserved_stack_access(false),
 919 #ifndef PRODUCT
 920       _igv_idx(0),
 921       _trace_opto_output(directive->TraceOptoOutputOption),
 922 #endif
 923       _clinit_barrier_on_entry(false),
 924       _stress_seed(0),
 925       _comp_arena(mtCompiler, Arena::Tag::tag_comp),
 926       _barrier_set_state(BarrierSet::barrier_set()->barrier_set_c2()->create_barrier_state(comp_arena())),
 927       _env(ci_env),
 928       _directive(directive),
 929       _log(ci_env->log()),
 930       _first_failure_details(nullptr),
 931       _for_post_loop_igvn(comp_arena(), 8, 0, nullptr),
 932       _for_merge_stores_igvn(comp_arena(), 8, 0, nullptr),
 933       _congraph(nullptr),
 934       NOT_PRODUCT(_igv_printer(nullptr) COMMA)
 935           _unique(0),
 936       _dead_node_count(0),
 937       _dead_node_list(comp_arena()),
 938       _node_arena_one(mtCompiler, Arena::Tag::tag_node),
 939       _node_arena_two(mtCompiler, Arena::Tag::tag_node),
 940       _node_arena(&_node_arena_one),
 941       _mach_constant_base_node(nullptr),
 942       _Compile_types(mtCompiler, Arena::Tag::tag_type),
 943       _initial_gvn(nullptr),
 944       _igvn_worklist(nullptr),
 945       _types(nullptr),
 946       _node_hash(nullptr),
 947       _has_mh_late_inlines(false),
 948       _oom(false),
 949       _replay_inline_data(nullptr),
 950       _inline_printer(this),
 951       _java_calls(0),
 952       _inner_loops(0),
 953       _FIRST_STACK_mask(comp_arena()),
 954       _interpreter_frame_size(0),
 955       _regmask_arena(mtCompiler, Arena::Tag::tag_regmask),
 956       _output(nullptr),
 957 #ifndef PRODUCT
 958       _in_dump_cnt(0),
 959 #endif
 960       _allowed_reasons(0) {
 961   C = this;
 962 
 963   // try to reuse an existing stub
 964   {
 965     BlobId blob_id = StubInfo::blob(_stub_id);
 966     CodeBlob* blob = AOTCodeCache::load_code_blob(AOTCodeEntry::C2Blob, blob_id);
 967     if (blob != nullptr) {
 968       RuntimeStub* rs = blob->as_runtime_stub();
 969       _stub_entry_point = rs->entry_point();
 970       return;
 971     }
 972   }
 973 
 974   TraceTime t1(nullptr, &_t_totalCompilation, CITime, false);
 975   TraceTime t2(nullptr, &_t_stubCompilation, CITime, false);
 976 
 977 #ifndef PRODUCT
 978   set_print_assembly(PrintFrameConverterAssembly);
 979   set_parsed_irreducible_loop(false);
 980 #else
 981   set_print_assembly(false); // Must initialize.
 982 #endif
 983   set_has_irreducible_loop(false); // no loops
 984 
 985   CompileWrapper cw(this);
 986   Init(/*do_aliasing=*/ false);
 987   init_tf((*generator)());
 988 
 989   _igvn_worklist = new (comp_arena()) Unique_Node_List(comp_arena());
 990   _types = new (comp_arena()) Type_Array(comp_arena());
 991   _node_hash = new (comp_arena()) NodeHash(comp_arena(), 255);
 992 
 993   if (StressLCM || StressGCM || StressBailout) {
 994     initialize_stress_seed(directive);
 995   }
 996 
 997   {
 998     PhaseGVN gvn;
 999     set_initial_gvn(&gvn);    // not significant, but GraphKit guys use it pervasively
1000     gvn.transform(top());
1001 
1002     GraphKit kit;
1003     kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
1004   }
1005 
1006   NOT_PRODUCT( verify_graph_edges(); )
1007 
1008   Code_Gen();
1009 }
1010 
1011 Compile::~Compile() {
1012   delete _first_failure_details;
1013 };
1014 
1015 //------------------------------Init-------------------------------------------
1016 // Prepare for a single compilation
1017 void Compile::Init(bool aliasing) {
1018   _do_aliasing = aliasing;
1019   _unique  = 0;
1020   _regalloc = nullptr;
1021 
1022   _tf      = nullptr;  // filled in later
1023   _top     = nullptr;  // cached later
1024   _matcher = nullptr;  // filled in later
1025   _cfg     = nullptr;  // filled in later
1026 
1027   _node_note_array = nullptr;
1028   _default_node_notes = nullptr;
1029   DEBUG_ONLY( _modified_nodes = nullptr; ) // Used in Optimize()
1030 
1031   _immutable_memory = nullptr; // filled in at first inquiry
1032 
1033 #ifdef ASSERT
1034   _phase_optimize_finished = false;
1035   _phase_verify_ideal_loop = false;
1036   _exception_backedge = false;
1037   _type_verify = nullptr;
1038 #endif
1039 
1040   // Globally visible Nodes
1041   // First set TOP to null to give safe behavior during creation of RootNode
1042   set_cached_top_node(nullptr);
1043   set_root(new RootNode());
1044   // Now that you have a Root to point to, create the real TOP
1045   set_cached_top_node( new ConNode(Type::TOP) );
1046   set_recent_alloc(nullptr, nullptr);
1047 
1048   // Create Debug Information Recorder to record scopes, oopmaps, etc.
1049   env()->set_oop_recorder(new OopRecorder(env()->arena()));
1050   env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
1051   env()->set_dependencies(new Dependencies(env()));
1052 
1053   _fixed_slots = 0;
1054   set_has_split_ifs(false);
1055   set_has_loops(false); // first approximation
1056   set_has_stringbuilder(false);
1057   set_has_boxed_value(false);
1058   _trap_can_recompile = false;  // no traps emitted yet
1059   _major_progress = true; // start out assuming good things will happen
1060   set_has_unsafe_access(false);
1061   set_max_vector_size(0);
1062   set_clear_upper_avx(false);  //false as default for clear upper bits of ymm registers
1063   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
1064   set_decompile_count(0);
1065 
1066 #ifndef PRODUCT
1067   _phase_counter = 0;
1068   Copy::zero_to_bytes(_igv_phase_iter, sizeof(_igv_phase_iter));
1069 #endif
1070 
1071   set_do_freq_based_layout(_directive->BlockLayoutByFrequencyOption);
1072   _loop_opts_cnt = LoopOptsCount;
1073   set_do_inlining(Inline);
1074   set_max_inline_size(MaxInlineSize);
1075   set_freq_inline_size(FreqInlineSize);
1076   set_do_scheduling(OptoScheduling);
1077 
1078   set_do_vector_loop(false);
1079   set_has_monitors(false);
1080   set_has_scoped_access(false);
1081 
1082   if (AllowVectorizeOnDemand) {
1083     if (has_method() && _directive->VectorizeOption) {
1084       set_do_vector_loop(true);
1085       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());})
1086     } else if (has_method() && method()->name() != nullptr &&
1087                method()->intrinsic_id() == vmIntrinsics::_forEachRemaining) {
1088       set_do_vector_loop(true);
1089     }
1090   }
1091   set_use_cmove(UseCMoveUnconditionally /* || do_vector_loop()*/); //TODO: consider do_vector_loop() mandate use_cmove unconditionally
1092   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());})
1093 
1094   _max_node_limit = _directive->MaxNodeLimitOption;
1095 
1096   if (VM_Version::supports_fast_class_init_checks() && has_method() && !is_osr_compilation() && method()->needs_clinit_barrier()) {
1097     set_clinit_barrier_on_entry(true);
1098   }
1099   if (debug_info()->recording_non_safepoints()) {
1100     set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
1101                         (comp_arena(), 8, 0, nullptr));
1102     set_default_node_notes(Node_Notes::make(this));
1103   }
1104 
1105   const int grow_ats = 16;
1106   _max_alias_types = grow_ats;
1107   _alias_types   = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
1108   AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType,  grow_ats);
1109   Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
1110   {
1111     for (int i = 0; i < grow_ats; i++)  _alias_types[i] = &ats[i];
1112   }
1113   // Initialize the first few types.
1114   _alias_types[AliasIdxTop]->Init(AliasIdxTop, nullptr);
1115   _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
1116   _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
1117   _num_alias_types = AliasIdxRaw+1;
1118   // Zero out the alias type cache.
1119   Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
1120   // A null adr_type hits in the cache right away.  Preload the right answer.
1121   probe_alias_cache(nullptr)->_index = AliasIdxTop;
1122 }
1123 
1124 #ifdef ASSERT
1125 // Verify that the current StartNode is valid.
1126 void Compile::verify_start(StartNode* s) const {
1127   assert(failing_internal() || s == start(), "should be StartNode");
1128 }
1129 #endif
1130 
1131 /**
1132  * Return the 'StartNode'. We must not have a pending failure, since the ideal graph
1133  * can be in an inconsistent state, i.e., we can get segmentation faults when traversing
1134  * the ideal graph.
1135  */
1136 StartNode* Compile::start() const {
1137   assert (!failing_internal() || C->failure_is_artificial(), "Must not have pending failure. Reason is: %s", failure_reason());
1138   for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
1139     Node* start = root()->fast_out(i);
1140     if (start->is_Start()) {
1141       return start->as_Start();
1142     }
1143   }
1144   fatal("Did not find Start node!");
1145   return nullptr;
1146 }
1147 
1148 //-------------------------------immutable_memory-------------------------------------
1149 // Access immutable memory
1150 Node* Compile::immutable_memory() {
1151   if (_immutable_memory != nullptr) {
1152     return _immutable_memory;
1153   }
1154   StartNode* s = start();
1155   for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
1156     Node *p = s->fast_out(i);
1157     if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
1158       _immutable_memory = p;
1159       return _immutable_memory;
1160     }
1161   }
1162   ShouldNotReachHere();
1163   return nullptr;
1164 }
1165 
1166 //----------------------set_cached_top_node------------------------------------
1167 // Install the cached top node, and make sure Node::is_top works correctly.
1168 void Compile::set_cached_top_node(Node* tn) {
1169   if (tn != nullptr)  verify_top(tn);
1170   Node* old_top = _top;
1171   _top = tn;
1172   // Calling Node::setup_is_top allows the nodes the chance to adjust
1173   // their _out arrays.
1174   if (_top != nullptr)     _top->setup_is_top();
1175   if (old_top != nullptr)  old_top->setup_is_top();
1176   assert(_top == nullptr || top()->is_top(), "");
1177 }
1178 
1179 #ifdef ASSERT
1180 uint Compile::count_live_nodes_by_graph_walk() {
1181   Unique_Node_List useful(comp_arena());
1182   // Get useful node list by walking the graph.
1183   identify_useful_nodes(useful);
1184   return useful.size();
1185 }
1186 
1187 void Compile::print_missing_nodes() {
1188 
1189   // Return if CompileLog is null and PrintIdealNodeCount is false.
1190   if ((_log == nullptr) && (! PrintIdealNodeCount)) {
1191     return;
1192   }
1193 
1194   // This is an expensive function. It is executed only when the user
1195   // specifies VerifyIdealNodeCount option or otherwise knows the
1196   // additional work that needs to be done to identify reachable nodes
1197   // by walking the flow graph and find the missing ones using
1198   // _dead_node_list.
1199 
1200   Unique_Node_List useful(comp_arena());
1201   // Get useful node list by walking the graph.
1202   identify_useful_nodes(useful);
1203 
1204   uint l_nodes = C->live_nodes();
1205   uint l_nodes_by_walk = useful.size();
1206 
1207   if (l_nodes != l_nodes_by_walk) {
1208     if (_log != nullptr) {
1209       _log->begin_head("mismatched_nodes count='%d'", abs((int) (l_nodes - l_nodes_by_walk)));
1210       _log->stamp();
1211       _log->end_head();
1212     }
1213     VectorSet& useful_member_set = useful.member_set();
1214     int last_idx = l_nodes_by_walk;
1215     for (int i = 0; i < last_idx; i++) {
1216       if (useful_member_set.test(i)) {
1217         if (_dead_node_list.test(i)) {
1218           if (_log != nullptr) {
1219             _log->elem("mismatched_node_info node_idx='%d' type='both live and dead'", i);
1220           }
1221           if (PrintIdealNodeCount) {
1222             // Print the log message to tty
1223               tty->print_cr("mismatched_node idx='%d' both live and dead'", i);
1224               useful.at(i)->dump();
1225           }
1226         }
1227       }
1228       else if (! _dead_node_list.test(i)) {
1229         if (_log != nullptr) {
1230           _log->elem("mismatched_node_info node_idx='%d' type='neither live nor dead'", i);
1231         }
1232         if (PrintIdealNodeCount) {
1233           // Print the log message to tty
1234           tty->print_cr("mismatched_node idx='%d' type='neither live nor dead'", i);
1235         }
1236       }
1237     }
1238     if (_log != nullptr) {
1239       _log->tail("mismatched_nodes");
1240     }
1241   }
1242 }
1243 void Compile::record_modified_node(Node* n) {
1244   if (_modified_nodes != nullptr && !_inlining_incrementally && !n->is_Con()) {
1245     _modified_nodes->push(n);
1246   }
1247 }
1248 
1249 void Compile::remove_modified_node(Node* n) {
1250   if (_modified_nodes != nullptr) {
1251     _modified_nodes->remove(n);
1252   }
1253 }
1254 #endif
1255 
1256 #ifndef PRODUCT
1257 void Compile::verify_top(Node* tn) const {
1258   if (tn != nullptr) {
1259     assert(tn->is_Con(), "top node must be a constant");
1260     assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
1261     assert(tn->in(0) != nullptr, "must have live top node");
1262   }
1263 }
1264 #endif
1265 
1266 
1267 ///-------------------Managing Per-Node Debug & Profile Info-------------------
1268 
1269 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
1270   guarantee(arr != nullptr, "");
1271   int num_blocks = arr->length();
1272   if (grow_by < num_blocks)  grow_by = num_blocks;
1273   int num_notes = grow_by * _node_notes_block_size;
1274   Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
1275   Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
1276   while (num_notes > 0) {
1277     arr->append(notes);
1278     notes     += _node_notes_block_size;
1279     num_notes -= _node_notes_block_size;
1280   }
1281   assert(num_notes == 0, "exact multiple, please");
1282 }
1283 
1284 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
1285   if (source == nullptr || dest == nullptr)  return false;
1286 
1287   if (dest->is_Con())
1288     return false;               // Do not push debug info onto constants.
1289 
1290 #ifdef ASSERT
1291   // Leave a bread crumb trail pointing to the original node:
1292   if (dest != nullptr && dest != source && dest->debug_orig() == nullptr) {
1293     dest->set_debug_orig(source);
1294   }
1295 #endif
1296 
1297   if (node_note_array() == nullptr)
1298     return false;               // Not collecting any notes now.
1299 
1300   // This is a copy onto a pre-existing node, which may already have notes.
1301   // If both nodes have notes, do not overwrite any pre-existing notes.
1302   Node_Notes* source_notes = node_notes_at(source->_idx);
1303   if (source_notes == nullptr || source_notes->is_clear())  return false;
1304   Node_Notes* dest_notes   = node_notes_at(dest->_idx);
1305   if (dest_notes == nullptr || dest_notes->is_clear()) {
1306     return set_node_notes_at(dest->_idx, source_notes);
1307   }
1308 
1309   Node_Notes merged_notes = (*source_notes);
1310   // The order of operations here ensures that dest notes will win...
1311   merged_notes.update_from(dest_notes);
1312   return set_node_notes_at(dest->_idx, &merged_notes);
1313 }
1314 
1315 
1316 //--------------------------allow_range_check_smearing-------------------------
1317 // Gating condition for coalescing similar range checks.
1318 // Sometimes we try 'speculatively' replacing a series of a range checks by a
1319 // single covering check that is at least as strong as any of them.
1320 // If the optimization succeeds, the simplified (strengthened) range check
1321 // will always succeed.  If it fails, we will deopt, and then give up
1322 // on the optimization.
1323 bool Compile::allow_range_check_smearing() const {
1324   // If this method has already thrown a range-check,
1325   // assume it was because we already tried range smearing
1326   // and it failed.
1327   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
1328   return !already_trapped;
1329 }
1330 
1331 
1332 //------------------------------flatten_alias_type-----------------------------
1333 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
1334   assert(do_aliasing(), "Aliasing should be enabled");
1335   int offset = tj->offset();
1336   TypePtr::PTR ptr = tj->ptr();
1337 
1338   // Known instance (scalarizable allocation) alias only with itself.
1339   bool is_known_inst = tj->isa_oopptr() != nullptr &&
1340                        tj->is_oopptr()->is_known_instance();
1341 
1342   // Process weird unsafe references.
1343   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
1344     assert(InlineUnsafeOps || StressReflectiveCode, "indeterminate pointers come only from unsafe ops");
1345     assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
1346     tj = TypeOopPtr::BOTTOM;
1347     ptr = tj->ptr();
1348     offset = tj->offset();
1349   }
1350 
1351   // Array pointers need some flattening
1352   const TypeAryPtr* ta = tj->isa_aryptr();
1353   if (ta && ta->is_stable()) {
1354     // Erase stability property for alias analysis.
1355     tj = ta = ta->cast_to_stable(false);
1356   }
1357   if( ta && is_known_inst ) {
1358     if ( offset != Type::OffsetBot &&
1359          offset > arrayOopDesc::length_offset_in_bytes() ) {
1360       offset = Type::OffsetBot; // Flatten constant access into array body only
1361       tj = ta = ta->
1362               remove_speculative()->
1363               cast_to_ptr_type(ptr)->
1364               with_offset(offset);
1365     }
1366   } else if (ta) {
1367     // For arrays indexed by constant indices, we flatten the alias
1368     // space to include all of the array body.  Only the header, klass
1369     // and array length can be accessed un-aliased.
1370     if( offset != Type::OffsetBot ) {
1371       if( ta->const_oop() ) { // MethodData* or Method*
1372         offset = Type::OffsetBot;   // Flatten constant access into array body
1373         tj = ta = ta->
1374                 remove_speculative()->
1375                 cast_to_ptr_type(ptr)->
1376                 cast_to_exactness(false)->
1377                 with_offset(offset);
1378       } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
1379         // range is OK as-is.
1380         tj = ta = TypeAryPtr::RANGE;
1381       } else if( offset == oopDesc::klass_offset_in_bytes() ) {
1382         tj = TypeInstPtr::KLASS; // all klass loads look alike
1383         ta = TypeAryPtr::RANGE; // generic ignored junk
1384         ptr = TypePtr::BotPTR;
1385       } else if( offset == oopDesc::mark_offset_in_bytes() ) {
1386         tj = TypeInstPtr::MARK;
1387         ta = TypeAryPtr::RANGE; // generic ignored junk
1388         ptr = TypePtr::BotPTR;
1389       } else {                  // Random constant offset into array body
1390         offset = Type::OffsetBot;   // Flatten constant access into array body
1391         tj = ta = ta->
1392                 remove_speculative()->
1393                 cast_to_ptr_type(ptr)->
1394                 cast_to_exactness(false)->
1395                 with_offset(offset);
1396       }
1397     }
1398     // Arrays of fixed size alias with arrays of unknown size.
1399     if (ta->size() != TypeInt::POS) {
1400       const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
1401       tj = ta = ta->
1402               remove_speculative()->
1403               cast_to_ptr_type(ptr)->
1404               with_ary(tary)->
1405               cast_to_exactness(false);
1406     }
1407     // Arrays of known objects become arrays of unknown objects.
1408     if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
1409       const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
1410       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,nullptr,false,offset);
1411     }
1412     if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
1413       const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
1414       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,nullptr,false,offset);
1415     }
1416     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
1417     // cannot be distinguished by bytecode alone.
1418     if (ta->elem() == TypeInt::BOOL) {
1419       const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
1420       ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
1421       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,offset);
1422     }
1423     // During the 2nd round of IterGVN, NotNull castings are removed.
1424     // Make sure the Bottom and NotNull variants alias the same.
1425     // Also, make sure exact and non-exact variants alias the same.
1426     if (ptr == TypePtr::NotNull || ta->klass_is_exact() || ta->speculative() != nullptr) {
1427       tj = ta = ta->
1428               remove_speculative()->
1429               cast_to_ptr_type(TypePtr::BotPTR)->
1430               cast_to_exactness(false)->
1431               with_offset(offset);
1432     }
1433   }
1434 
1435   // Oop pointers need some flattening
1436   const TypeInstPtr *to = tj->isa_instptr();
1437   if (to && to != TypeOopPtr::BOTTOM) {
1438     ciInstanceKlass* ik = to->instance_klass();
1439     if( ptr == TypePtr::Constant ) {
1440       if (ik != ciEnv::current()->Class_klass() ||
1441           offset < ik->layout_helper_size_in_bytes()) {
1442         // No constant oop pointers (such as Strings); they alias with
1443         // unknown strings.
1444         assert(!is_known_inst, "not scalarizable allocation");
1445         tj = to = to->
1446                 cast_to_instance_id(TypeOopPtr::InstanceBot)->
1447                 remove_speculative()->
1448                 cast_to_ptr_type(TypePtr::BotPTR)->
1449                 cast_to_exactness(false);
1450       }
1451     } else if( is_known_inst ) {
1452       tj = to; // Keep NotNull and klass_is_exact for instance type
1453     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
1454       // During the 2nd round of IterGVN, NotNull castings are removed.
1455       // Make sure the Bottom and NotNull variants alias the same.
1456       // Also, make sure exact and non-exact variants alias the same.
1457       tj = to = to->
1458               remove_speculative()->
1459               cast_to_instance_id(TypeOopPtr::InstanceBot)->
1460               cast_to_ptr_type(TypePtr::BotPTR)->
1461               cast_to_exactness(false);
1462     }
1463     if (to->speculative() != nullptr) {
1464       tj = to = to->remove_speculative();
1465     }
1466     // Canonicalize the holder of this field
1467     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
1468       // First handle header references such as a LoadKlassNode, even if the
1469       // object's klass is unloaded at compile time (4965979).
1470       if (!is_known_inst) { // Do it only for non-instance types
1471         tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, nullptr, offset);
1472       }
1473     } else if (offset < 0 || offset >= ik->layout_helper_size_in_bytes()) {
1474       // Static fields are in the space above the normal instance
1475       // fields in the java.lang.Class instance.
1476       if (ik != ciEnv::current()->Class_klass()) {
1477         to = nullptr;
1478         tj = TypeOopPtr::BOTTOM;
1479         offset = tj->offset();
1480       }
1481     } else {
1482       ciInstanceKlass *canonical_holder = ik->get_canonical_holder(offset);
1483       assert(offset < canonical_holder->layout_helper_size_in_bytes(), "");
1484       assert(tj->offset() == offset, "no change to offset expected");
1485       bool xk = to->klass_is_exact();
1486       int instance_id = to->instance_id();
1487 
1488       // If the input type's class is the holder: if exact, the type only includes interfaces implemented by the holder
1489       // but if not exact, it may include extra interfaces: build new type from the holder class to make sure only
1490       // its interfaces are included.
1491       if (xk && ik->equals(canonical_holder)) {
1492         assert(tj == TypeInstPtr::make(to->ptr(), canonical_holder, is_known_inst, nullptr, offset, instance_id), "exact type should be canonical type");
1493       } else {
1494         assert(xk || !is_known_inst, "Known instance should be exact type");
1495         tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, is_known_inst, nullptr, offset, instance_id);
1496       }
1497     }
1498   }
1499 
1500   // Klass pointers to object array klasses need some flattening
1501   const TypeKlassPtr *tk = tj->isa_klassptr();
1502   if( tk ) {
1503     // If we are referencing a field within a Klass, we need
1504     // to assume the worst case of an Object.  Both exact and
1505     // inexact types must flatten to the same alias class so
1506     // use NotNull as the PTR.
1507     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
1508       tj = tk = TypeInstKlassPtr::make(TypePtr::NotNull,
1509                                        env()->Object_klass(),
1510                                        offset);
1511     }
1512 
1513     if (tk->isa_aryklassptr() && tk->is_aryklassptr()->elem()->isa_klassptr()) {
1514       ciKlass* k = ciObjArrayKlass::make(env()->Object_klass());
1515       if (!k || !k->is_loaded()) {                  // Only fails for some -Xcomp runs
1516         tj = tk = TypeInstKlassPtr::make(TypePtr::NotNull, env()->Object_klass(), offset);
1517       } else {
1518         tj = tk = TypeAryKlassPtr::make(TypePtr::NotNull, tk->is_aryklassptr()->elem(), k, offset);
1519       }
1520     }
1521 
1522     // Check for precise loads from the primary supertype array and force them
1523     // to the supertype cache alias index.  Check for generic array loads from
1524     // the primary supertype array and also force them to the supertype cache
1525     // alias index.  Since the same load can reach both, we need to merge
1526     // these 2 disparate memories into the same alias class.  Since the
1527     // primary supertype array is read-only, there's no chance of confusion
1528     // where we bypass an array load and an array store.
1529     int primary_supers_offset = in_bytes(Klass::primary_supers_offset());
1530     if (offset == Type::OffsetBot ||
1531         (offset >= primary_supers_offset &&
1532          offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
1533         offset == (int)in_bytes(Klass::secondary_super_cache_offset())) {
1534       offset = in_bytes(Klass::secondary_super_cache_offset());
1535       tj = tk = tk->with_offset(offset);
1536     }
1537   }
1538 
1539   // Flatten all Raw pointers together.
1540   if (tj->base() == Type::RawPtr)
1541     tj = TypeRawPtr::BOTTOM;
1542 
1543   if (tj->base() == Type::AnyPtr)
1544     tj = TypePtr::BOTTOM;      // An error, which the caller must check for.
1545 
1546   offset = tj->offset();
1547   assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
1548 
1549   assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
1550           (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
1551           (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
1552           (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
1553           (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1554           (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1555           (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr),
1556           "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
1557   assert( tj->ptr() != TypePtr::TopPTR &&
1558           tj->ptr() != TypePtr::AnyNull &&
1559           tj->ptr() != TypePtr::Null, "No imprecise addresses" );
1560 //    assert( tj->ptr() != TypePtr::Constant ||
1561 //            tj->base() == Type::RawPtr ||
1562 //            tj->base() == Type::KlassPtr, "No constant oop addresses" );
1563 
1564   return tj;
1565 }
1566 
1567 void Compile::AliasType::Init(int i, const TypePtr* at) {
1568   assert(AliasIdxTop <= i && i < Compile::current()->_max_alias_types, "Invalid alias index");
1569   _index = i;
1570   _adr_type = at;
1571   _field = nullptr;
1572   _element = nullptr;
1573   _is_rewritable = true; // default
1574   const TypeOopPtr *atoop = (at != nullptr) ? at->isa_oopptr() : nullptr;
1575   if (atoop != nullptr && atoop->is_known_instance()) {
1576     const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
1577     _general_index = Compile::current()->get_alias_index(gt);
1578   } else {
1579     _general_index = 0;
1580   }
1581 }
1582 
1583 BasicType Compile::AliasType::basic_type() const {
1584   if (element() != nullptr) {
1585     const Type* element = adr_type()->is_aryptr()->elem();
1586     return element->isa_narrowoop() ? T_OBJECT : element->array_element_basic_type();
1587   } if (field() != nullptr) {
1588     return field()->layout_type();
1589   } else {
1590     return T_ILLEGAL; // unknown
1591   }
1592 }
1593 
1594 //---------------------------------print_on------------------------------------
1595 #ifndef PRODUCT
1596 void Compile::AliasType::print_on(outputStream* st) {
1597   if (index() < 10)
1598         st->print("@ <%d> ", index());
1599   else  st->print("@ <%d>",  index());
1600   st->print(is_rewritable() ? "   " : " RO");
1601   int offset = adr_type()->offset();
1602   if (offset == Type::OffsetBot)
1603         st->print(" +any");
1604   else  st->print(" +%-3d", offset);
1605   st->print(" in ");
1606   adr_type()->dump_on(st);
1607   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
1608   if (field() != nullptr && tjp) {
1609     if (tjp->is_instptr()->instance_klass()  != field()->holder() ||
1610         tjp->offset() != field()->offset_in_bytes()) {
1611       st->print(" != ");
1612       field()->print();
1613       st->print(" ***");
1614     }
1615   }
1616 }
1617 
1618 void print_alias_types() {
1619   Compile* C = Compile::current();
1620   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
1621   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
1622     C->alias_type(idx)->print_on(tty);
1623     tty->cr();
1624   }
1625 }
1626 #endif
1627 
1628 
1629 //----------------------------probe_alias_cache--------------------------------
1630 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
1631   intptr_t key = (intptr_t) adr_type;
1632   key ^= key >> logAliasCacheSize;
1633   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
1634 }
1635 
1636 
1637 //-----------------------------grow_alias_types--------------------------------
1638 void Compile::grow_alias_types() {
1639   const int old_ats  = _max_alias_types; // how many before?
1640   const int new_ats  = old_ats;          // how many more?
1641   const int grow_ats = old_ats+new_ats;  // how many now?
1642   _max_alias_types = grow_ats;
1643   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
1644   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
1645   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
1646   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
1647 }
1648 
1649 
1650 //--------------------------------find_alias_type------------------------------
1651 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field) {
1652   if (!do_aliasing()) {
1653     return alias_type(AliasIdxBot);
1654   }
1655 
1656   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1657   if (ace->_adr_type == adr_type) {
1658     return alias_type(ace->_index);
1659   }
1660 
1661   // Handle special cases.
1662   if (adr_type == nullptr)          return alias_type(AliasIdxTop);
1663   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
1664 
1665   // Do it the slow way.
1666   const TypePtr* flat = flatten_alias_type(adr_type);
1667 
1668 #ifdef ASSERT
1669   {
1670     ResourceMark rm;
1671     assert(flat == flatten_alias_type(flat), "not idempotent: adr_type = %s; flat = %s => %s",
1672            Type::str(adr_type), Type::str(flat), Type::str(flatten_alias_type(flat)));
1673     assert(flat != TypePtr::BOTTOM, "cannot alias-analyze an untyped ptr: adr_type = %s",
1674            Type::str(adr_type));
1675     if (flat->isa_oopptr() && !flat->isa_klassptr()) {
1676       const TypeOopPtr* foop = flat->is_oopptr();
1677       // Scalarizable allocations have exact klass always.
1678       bool exact = !foop->klass_is_exact() || foop->is_known_instance();
1679       const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
1680       assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type: foop = %s; xoop = %s",
1681              Type::str(foop), Type::str(xoop));
1682     }
1683   }
1684 #endif
1685 
1686   int idx = AliasIdxTop;
1687   for (int i = 0; i < num_alias_types(); i++) {
1688     if (alias_type(i)->adr_type() == flat) {
1689       idx = i;
1690       break;
1691     }
1692   }
1693 
1694   if (idx == AliasIdxTop) {
1695     if (no_create)  return nullptr;
1696     // Grow the array if necessary.
1697     if (_num_alias_types == _max_alias_types)  grow_alias_types();
1698     // Add a new alias type.
1699     idx = _num_alias_types++;
1700     _alias_types[idx]->Init(idx, flat);
1701     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
1702     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
1703     if (flat->isa_instptr()) {
1704       if (flat->offset() == java_lang_Class::klass_offset()
1705           && flat->is_instptr()->instance_klass() == env()->Class_klass())
1706         alias_type(idx)->set_rewritable(false);
1707     }
1708     if (flat->isa_aryptr()) {
1709 #ifdef ASSERT
1710       const int header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1711       // (T_BYTE has the weakest alignment and size restrictions...)
1712       assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
1713 #endif
1714       if (flat->offset() == TypePtr::OffsetBot) {
1715         alias_type(idx)->set_element(flat->is_aryptr()->elem());
1716       }
1717     }
1718     if (flat->isa_klassptr()) {
1719       if (UseCompactObjectHeaders) {
1720         if (flat->offset() == in_bytes(Klass::prototype_header_offset()))
1721           alias_type(idx)->set_rewritable(false);
1722       }
1723       if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
1724         alias_type(idx)->set_rewritable(false);
1725       if (flat->offset() == in_bytes(Klass::misc_flags_offset()))
1726         alias_type(idx)->set_rewritable(false);
1727       if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
1728         alias_type(idx)->set_rewritable(false);
1729       if (flat->offset() == in_bytes(Klass::secondary_super_cache_offset()))
1730         alias_type(idx)->set_rewritable(false);
1731     }
1732 
1733     if (flat->isa_instklassptr()) {
1734       if (flat->offset() == in_bytes(InstanceKlass::access_flags_offset())) {
1735         alias_type(idx)->set_rewritable(false);
1736       }
1737     }
1738     // %%% (We would like to finalize JavaThread::threadObj_offset(),
1739     // but the base pointer type is not distinctive enough to identify
1740     // references into JavaThread.)
1741 
1742     // Check for final fields.
1743     const TypeInstPtr* tinst = flat->isa_instptr();
1744     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
1745       ciField* field;
1746       if (tinst->const_oop() != nullptr &&
1747           tinst->instance_klass() == ciEnv::current()->Class_klass() &&
1748           tinst->offset() >= (tinst->instance_klass()->layout_helper_size_in_bytes())) {
1749         // static field
1750         ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
1751         field = k->get_field_by_offset(tinst->offset(), true);
1752       } else {
1753         ciInstanceKlass *k = tinst->instance_klass();
1754         field = k->get_field_by_offset(tinst->offset(), false);
1755       }
1756       assert(field == nullptr ||
1757              original_field == nullptr ||
1758              (field->holder() == original_field->holder() &&
1759               field->offset_in_bytes() == original_field->offset_in_bytes() &&
1760               field->is_static() == original_field->is_static()), "wrong field?");
1761       // Set field() and is_rewritable() attributes.
1762       if (field != nullptr)  alias_type(idx)->set_field(field);
1763     }
1764   }
1765 
1766   // Fill the cache for next time.
1767   ace->_adr_type = adr_type;
1768   ace->_index    = idx;
1769   assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
1770 
1771   // Might as well try to fill the cache for the flattened version, too.
1772   AliasCacheEntry* face = probe_alias_cache(flat);
1773   if (face->_adr_type == nullptr) {
1774     face->_adr_type = flat;
1775     face->_index    = idx;
1776     assert(alias_type(flat) == alias_type(idx), "flat type must work too");
1777   }
1778 
1779   return alias_type(idx);
1780 }
1781 
1782 
1783 Compile::AliasType* Compile::alias_type(ciField* field) {
1784   const TypeOopPtr* t;
1785   if (field->is_static())
1786     t = TypeInstPtr::make(field->holder()->java_mirror());
1787   else
1788     t = TypeOopPtr::make_from_klass_raw(field->holder());
1789   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);
1790   assert((field->is_final() || field->is_stable()) == !atp->is_rewritable(), "must get the rewritable bits correct");
1791   return atp;
1792 }
1793 
1794 
1795 //------------------------------have_alias_type--------------------------------
1796 bool Compile::have_alias_type(const TypePtr* adr_type) {
1797   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1798   if (ace->_adr_type == adr_type) {
1799     return true;
1800   }
1801 
1802   // Handle special cases.
1803   if (adr_type == nullptr)             return true;
1804   if (adr_type == TypePtr::BOTTOM)  return true;
1805 
1806   return find_alias_type(adr_type, true, nullptr) != nullptr;
1807 }
1808 
1809 //-----------------------------must_alias--------------------------------------
1810 // True if all values of the given address type are in the given alias category.
1811 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
1812   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1813   if (adr_type == nullptr)              return true;  // null serves as TypePtr::TOP
1814   if (alias_idx == AliasIdxTop)         return false; // the empty category
1815   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
1816 
1817   // the only remaining possible overlap is identity
1818   int adr_idx = get_alias_index(adr_type);
1819   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1820   assert(adr_idx == alias_idx ||
1821          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
1822           && adr_type                       != TypeOopPtr::BOTTOM),
1823          "should not be testing for overlap with an unsafe pointer");
1824   return adr_idx == alias_idx;
1825 }
1826 
1827 //------------------------------can_alias--------------------------------------
1828 // True if any values of the given address type are in the given alias category.
1829 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
1830   if (alias_idx == AliasIdxTop)         return false; // the empty category
1831   if (adr_type == nullptr)              return false; // null serves as TypePtr::TOP
1832   // Known instance doesn't alias with bottom memory
1833   if (alias_idx == AliasIdxBot)         return !adr_type->is_known_instance();                   // the universal category
1834   if (adr_type->base() == Type::AnyPtr) return !C->get_adr_type(alias_idx)->is_known_instance(); // TypePtr::BOTTOM or its twins
1835 
1836   // the only remaining possible overlap is identity
1837   int adr_idx = get_alias_index(adr_type);
1838   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1839   return adr_idx == alias_idx;
1840 }
1841 
1842 // Mark all ParsePredicateNodes as useless. They will later be removed from the graph in IGVN together with their
1843 // uncommon traps if no Runtime Predicates were created from the Parse Predicates.
1844 void Compile::mark_parse_predicate_nodes_useless(PhaseIterGVN& igvn) {
1845   if (parse_predicate_count() == 0) {
1846     return;
1847   }
1848   for (int i = 0; i < parse_predicate_count(); i++) {
1849     ParsePredicateNode* parse_predicate = _parse_predicates.at(i);
1850     parse_predicate->mark_useless(igvn);
1851   }
1852   _parse_predicates.clear();
1853 }
1854 
1855 void Compile::record_for_post_loop_opts_igvn(Node* n) {
1856   if (!n->for_post_loop_opts_igvn()) {
1857     assert(!_for_post_loop_igvn.contains(n), "duplicate");
1858     n->add_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
1859     _for_post_loop_igvn.append(n);
1860   }
1861 }
1862 
1863 void Compile::remove_from_post_loop_opts_igvn(Node* n) {
1864   n->remove_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
1865   _for_post_loop_igvn.remove(n);
1866 }
1867 
1868 void Compile::process_for_post_loop_opts_igvn(PhaseIterGVN& igvn) {
1869   // Verify that all previous optimizations produced a valid graph
1870   // at least to this point, even if no loop optimizations were done.
1871   PhaseIdealLoop::verify(igvn);
1872 
1873   if (has_loops() || _loop_opts_cnt > 0) {
1874     print_method(PHASE_AFTER_LOOP_OPTS, 2);
1875   }
1876   C->set_post_loop_opts_phase(); // no more loop opts allowed
1877 
1878   assert(!C->major_progress(), "not cleared");
1879 
1880   if (_for_post_loop_igvn.length() > 0) {
1881     while (_for_post_loop_igvn.length() > 0) {
1882       Node* n = _for_post_loop_igvn.pop();
1883       n->remove_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
1884       igvn._worklist.push(n);
1885     }
1886     igvn.optimize();
1887     if (failing()) return;
1888     assert(_for_post_loop_igvn.length() == 0, "no more delayed nodes allowed");
1889     assert(C->parse_predicate_count() == 0, "all parse predicates should have been removed now");
1890 
1891     // Sometimes IGVN sets major progress (e.g., when processing loop nodes).
1892     if (C->major_progress()) {
1893       C->clear_major_progress(); // ensure that major progress is now clear
1894     }
1895   }
1896 }
1897 
1898 void Compile::record_for_merge_stores_igvn(Node* n) {
1899   if (!n->for_merge_stores_igvn()) {
1900     assert(!_for_merge_stores_igvn.contains(n), "duplicate");
1901     n->add_flag(Node::NodeFlags::Flag_for_merge_stores_igvn);
1902     _for_merge_stores_igvn.append(n);
1903   }
1904 }
1905 
1906 void Compile::remove_from_merge_stores_igvn(Node* n) {
1907   n->remove_flag(Node::NodeFlags::Flag_for_merge_stores_igvn);
1908   _for_merge_stores_igvn.remove(n);
1909 }
1910 
1911 // We need to wait with merging stores until RangeCheck smearing has removed the RangeChecks during
1912 // the post loops IGVN phase. If we do it earlier, then there may still be some RangeChecks between
1913 // the stores, and we merge the wrong sequence of stores.
1914 // Example:
1915 //   StoreI RangeCheck StoreI StoreI RangeCheck StoreI
1916 // Apply MergeStores:
1917 //   StoreI RangeCheck [   StoreL  ] RangeCheck StoreI
1918 // Remove more RangeChecks:
1919 //   StoreI            [   StoreL  ]            StoreI
1920 // But now it would have been better to do this instead:
1921 //   [         StoreL       ] [       StoreL         ]
1922 //
1923 // Note: we allow stores to merge in this dedicated IGVN round, and any later IGVN round,
1924 //       since we never unset _merge_stores_phase.
1925 void Compile::process_for_merge_stores_igvn(PhaseIterGVN& igvn) {
1926   C->set_merge_stores_phase();
1927 
1928   if (_for_merge_stores_igvn.length() > 0) {
1929     while (_for_merge_stores_igvn.length() > 0) {
1930       Node* n = _for_merge_stores_igvn.pop();
1931       n->remove_flag(Node::NodeFlags::Flag_for_merge_stores_igvn);
1932       igvn._worklist.push(n);
1933     }
1934     igvn.optimize();
1935     if (failing()) return;
1936     assert(_for_merge_stores_igvn.length() == 0, "no more delayed nodes allowed");
1937     print_method(PHASE_AFTER_MERGE_STORES, 3);
1938   }
1939 }
1940 
1941 void Compile::record_unstable_if_trap(UnstableIfTrap* trap) {
1942   if (OptimizeUnstableIf) {
1943     _unstable_if_traps.append(trap);
1944   }
1945 }
1946 
1947 void Compile::remove_useless_unstable_if_traps(Unique_Node_List& useful) {
1948   for (int i = _unstable_if_traps.length() - 1; i >= 0; i--) {
1949     UnstableIfTrap* trap = _unstable_if_traps.at(i);
1950     Node* n = trap->uncommon_trap();
1951     if (!useful.member(n)) {
1952       _unstable_if_traps.delete_at(i); // replaces i-th with last element which is known to be useful (already processed)
1953     }
1954   }
1955 }
1956 
1957 // Remove the unstable if trap associated with 'unc' from candidates. It is either dead
1958 // or fold-compares case. Return true if succeed or not found.
1959 //
1960 // In rare cases, the found trap has been processed. It is too late to delete it. Return
1961 // false and ask fold-compares to yield.
1962 //
1963 // 'fold-compares' may use the uncommon_trap of the dominating IfNode to cover the fused
1964 // IfNode. This breaks the unstable_if trap invariant: control takes the unstable path
1965 // when deoptimization does happen.
1966 bool Compile::remove_unstable_if_trap(CallStaticJavaNode* unc, bool yield) {
1967   for (int i = 0; i < _unstable_if_traps.length(); ++i) {
1968     UnstableIfTrap* trap = _unstable_if_traps.at(i);
1969     if (trap->uncommon_trap() == unc) {
1970       if (yield && trap->modified()) {
1971         return false;
1972       }
1973       _unstable_if_traps.delete_at(i);
1974       break;
1975     }
1976   }
1977   return true;
1978 }
1979 
1980 // Re-calculate unstable_if traps with the liveness of next_bci, which points to the unlikely path.
1981 // It needs to be done after igvn because fold-compares may fuse uncommon_traps and before renumbering.
1982 void Compile::process_for_unstable_if_traps(PhaseIterGVN& igvn) {
1983   for (int i = _unstable_if_traps.length() - 1; i >= 0; --i) {
1984     UnstableIfTrap* trap = _unstable_if_traps.at(i);
1985     CallStaticJavaNode* unc = trap->uncommon_trap();
1986     int next_bci = trap->next_bci();
1987     bool modified = trap->modified();
1988 
1989     if (next_bci != -1 && !modified) {
1990       assert(!_dead_node_list.test(unc->_idx), "changing a dead node!");
1991       JVMState* jvms = unc->jvms();
1992       ciMethod* method = jvms->method();
1993       ciBytecodeStream iter(method);
1994 
1995       iter.force_bci(jvms->bci());
1996       assert(next_bci == iter.next_bci() || next_bci == iter.get_dest(), "wrong next_bci at unstable_if");
1997       Bytecodes::Code c = iter.cur_bc();
1998       Node* lhs = nullptr;
1999       Node* rhs = nullptr;
2000       if (c == Bytecodes::_if_acmpeq || c == Bytecodes::_if_acmpne) {
2001         lhs = unc->peek_operand(0);
2002         rhs = unc->peek_operand(1);
2003       } else if (c == Bytecodes::_ifnull || c == Bytecodes::_ifnonnull) {
2004         lhs = unc->peek_operand(0);
2005       }
2006 
2007       ResourceMark rm;
2008       const MethodLivenessResult& live_locals = method->liveness_at_bci(next_bci);
2009       assert(live_locals.is_valid(), "broken liveness info");
2010       int len = (int)live_locals.size();
2011 
2012       for (int i = 0; i < len; i++) {
2013         Node* local = unc->local(jvms, i);
2014         // kill local using the liveness of next_bci.
2015         // give up when the local looks like an operand to secure reexecution.
2016         if (!live_locals.at(i) && !local->is_top() && local != lhs && local!= rhs) {
2017           uint idx = jvms->locoff() + i;
2018 #ifdef ASSERT
2019           if (PrintOpto && Verbose) {
2020             tty->print("[unstable_if] kill local#%d: ", idx);
2021             local->dump();
2022             tty->cr();
2023           }
2024 #endif
2025           igvn.replace_input_of(unc, idx, top());
2026           modified = true;
2027         }
2028       }
2029     }
2030 
2031     // keep the mondified trap for late query
2032     if (modified) {
2033       trap->set_modified();
2034     } else {
2035       _unstable_if_traps.delete_at(i);
2036     }
2037   }
2038   igvn.optimize();
2039 }
2040 
2041 // StringOpts and late inlining of string methods
2042 void Compile::inline_string_calls(bool parse_time) {
2043   {
2044     // remove useless nodes to make the usage analysis simpler
2045     ResourceMark rm;
2046     PhaseRemoveUseless pru(initial_gvn(), *igvn_worklist());
2047   }
2048 
2049   {
2050     ResourceMark rm;
2051     print_method(PHASE_BEFORE_STRINGOPTS, 3);
2052     PhaseStringOpts pso(initial_gvn());
2053     print_method(PHASE_AFTER_STRINGOPTS, 3);
2054   }
2055 
2056   // now inline anything that we skipped the first time around
2057   if (!parse_time) {
2058     _late_inlines_pos = _late_inlines.length();
2059   }
2060 
2061   while (_string_late_inlines.length() > 0) {
2062     CallGenerator* cg = _string_late_inlines.pop();
2063     cg->do_late_inline();
2064     if (failing())  return;
2065   }
2066   _string_late_inlines.trunc_to(0);
2067 }
2068 
2069 // Late inlining of boxing methods
2070 void Compile::inline_boxing_calls(PhaseIterGVN& igvn) {
2071   if (_boxing_late_inlines.length() > 0) {
2072     assert(has_boxed_value(), "inconsistent");
2073 
2074     set_inlining_incrementally(true);
2075 
2076     igvn_worklist()->ensure_empty(); // should be done with igvn
2077 
2078     _late_inlines_pos = _late_inlines.length();
2079 
2080     while (_boxing_late_inlines.length() > 0) {
2081       CallGenerator* cg = _boxing_late_inlines.pop();
2082       cg->do_late_inline();
2083       if (failing())  return;
2084     }
2085     _boxing_late_inlines.trunc_to(0);
2086 
2087     inline_incrementally_cleanup(igvn);
2088 
2089     set_inlining_incrementally(false);
2090   }
2091 }
2092 
2093 bool Compile::inline_incrementally_one() {
2094   assert(IncrementalInline, "incremental inlining should be on");
2095 
2096   TracePhase tp(_t_incrInline_inline);
2097 
2098   set_inlining_progress(false);
2099   set_do_cleanup(false);
2100 
2101   for (int i = 0; i < _late_inlines.length(); i++) {
2102     _late_inlines_pos = i+1;
2103     CallGenerator* cg = _late_inlines.at(i);
2104     bool is_scheduled_for_igvn_before = C->igvn_worklist()->member(cg->call_node());
2105     bool does_dispatch = cg->is_virtual_late_inline() || cg->is_mh_late_inline();
2106     if (inlining_incrementally() || does_dispatch) { // a call can be either inlined or strength-reduced to a direct call
2107       if (should_stress_inlining()) {
2108         // randomly add repeated inline attempt if stress-inlining
2109         cg->call_node()->set_generator(cg);
2110         C->igvn_worklist()->push(cg->call_node());
2111         continue;
2112       }
2113       cg->do_late_inline();
2114       assert(_late_inlines.at(i) == cg, "no insertions before current position allowed");
2115       if (failing()) {
2116         return false;
2117       } else if (inlining_progress()) {
2118         _late_inlines_pos = i+1; // restore the position in case new elements were inserted
2119         print_method(PHASE_INCREMENTAL_INLINE_STEP, 3, cg->call_node());
2120         break; // process one call site at a time
2121       } else {
2122         bool is_scheduled_for_igvn_after = C->igvn_worklist()->member(cg->call_node());
2123         if (!is_scheduled_for_igvn_before && is_scheduled_for_igvn_after) {
2124           // Avoid potential infinite loop if node already in the IGVN list
2125           assert(false, "scheduled for IGVN during inlining attempt");
2126         } else {
2127           // Ensure call node has not disappeared from IGVN worklist during a failed inlining attempt
2128           assert(!is_scheduled_for_igvn_before || is_scheduled_for_igvn_after, "call node removed from IGVN list during inlining pass");
2129           cg->call_node()->set_generator(cg);
2130         }
2131       }
2132     } else {
2133       // Ignore late inline direct calls when inlining is not allowed.
2134       // They are left in the late inline list when node budget is exhausted until the list is fully drained.
2135     }
2136   }
2137   // Remove processed elements.
2138   _late_inlines.remove_till(_late_inlines_pos);
2139   _late_inlines_pos = 0;
2140 
2141   assert(inlining_progress() || _late_inlines.length() == 0, "no progress");
2142 
2143   bool needs_cleanup = do_cleanup() || over_inlining_cutoff();
2144 
2145   set_inlining_progress(false);
2146   set_do_cleanup(false);
2147 
2148   bool force_cleanup = directive()->IncrementalInlineForceCleanupOption;
2149   return (_late_inlines.length() > 0) && !needs_cleanup && !force_cleanup;
2150 }
2151 
2152 void Compile::inline_incrementally_cleanup(PhaseIterGVN& igvn) {
2153   {
2154     TracePhase tp(_t_incrInline_pru);
2155     ResourceMark rm;
2156     PhaseRemoveUseless pru(initial_gvn(), *igvn_worklist());
2157   }
2158   {
2159     TracePhase tp(_t_incrInline_igvn);
2160     igvn.reset();
2161     igvn.optimize();
2162     if (failing()) return;
2163   }
2164   print_method(PHASE_INCREMENTAL_INLINE_CLEANUP, 3);
2165 }
2166 
2167 // Perform incremental inlining until bound on number of live nodes is reached
2168 void Compile::inline_incrementally(PhaseIterGVN& igvn) {
2169   TracePhase tp(_t_incrInline);
2170 
2171   set_inlining_incrementally(true);
2172   uint low_live_nodes = 0;
2173 
2174   while (_late_inlines.length() > 0) {
2175     if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2176       if (low_live_nodes < (uint)LiveNodeCountInliningCutoff * 8 / 10) {
2177         TracePhase tp(_t_incrInline_ideal);
2178         // PhaseIdealLoop is expensive so we only try it once we are
2179         // out of live nodes and we only try it again if the previous
2180         // helped got the number of nodes down significantly
2181         PhaseIdealLoop::optimize(igvn, LoopOptsNone);
2182         if (failing())  return;
2183         low_live_nodes = live_nodes();
2184         _major_progress = true;
2185       }
2186 
2187       if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2188         bool do_print_inlining = print_inlining() || print_intrinsics();
2189         if (do_print_inlining || log() != nullptr) {
2190           // Print inlining message for candidates that we couldn't inline for lack of space.
2191           for (int i = 0; i < _late_inlines.length(); i++) {
2192             CallGenerator* cg = _late_inlines.at(i);
2193             const char* msg = "live nodes > LiveNodeCountInliningCutoff";
2194             if (do_print_inlining) {
2195               inline_printer()->record(cg->method(), cg->call_node()->jvms(), InliningResult::FAILURE, msg);
2196             }
2197             log_late_inline_failure(cg, msg);
2198           }
2199         }
2200         break; // finish
2201       }
2202     }
2203 
2204     igvn_worklist()->ensure_empty(); // should be done with igvn
2205 
2206     while (inline_incrementally_one()) {
2207       assert(!failing_internal() || failure_is_artificial(), "inconsistent");
2208     }
2209     if (failing())  return;
2210 
2211     inline_incrementally_cleanup(igvn);
2212 
2213     print_method(PHASE_INCREMENTAL_INLINE_STEP, 3);
2214 
2215     if (failing())  return;
2216 
2217     if (_late_inlines.length() == 0) {
2218       break; // no more progress
2219     }
2220   }
2221 
2222   igvn_worklist()->ensure_empty(); // should be done with igvn
2223 
2224   if (_string_late_inlines.length() > 0) {
2225     assert(has_stringbuilder(), "inconsistent");
2226 
2227     inline_string_calls(false);
2228 
2229     if (failing())  return;
2230 
2231     inline_incrementally_cleanup(igvn);
2232   }
2233 
2234   set_inlining_incrementally(false);
2235 }
2236 
2237 void Compile::process_late_inline_calls_no_inline(PhaseIterGVN& igvn) {
2238   // "inlining_incrementally() == false" is used to signal that no inlining is allowed
2239   // (see LateInlineVirtualCallGenerator::do_late_inline_check() for details).
2240   // Tracking and verification of modified nodes is disabled by setting "_modified_nodes == nullptr"
2241   // as if "inlining_incrementally() == true" were set.
2242   assert(inlining_incrementally() == false, "not allowed");
2243   assert(_modified_nodes == nullptr, "not allowed");
2244   assert(_late_inlines.length() > 0, "sanity");
2245 
2246   while (_late_inlines.length() > 0) {
2247     igvn_worklist()->ensure_empty(); // should be done with igvn
2248 
2249     while (inline_incrementally_one()) {
2250       assert(!failing_internal() || failure_is_artificial(), "inconsistent");
2251     }
2252     if (failing())  return;
2253 
2254     inline_incrementally_cleanup(igvn);
2255   }
2256 }
2257 
2258 bool Compile::optimize_loops(PhaseIterGVN& igvn, LoopOptsMode mode) {
2259   if (_loop_opts_cnt > 0) {
2260     while (major_progress() && (_loop_opts_cnt > 0)) {
2261       TracePhase tp(_t_idealLoop);
2262       PhaseIdealLoop::optimize(igvn, mode);
2263       _loop_opts_cnt--;
2264       if (failing())  return false;
2265       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
2266     }
2267   }
2268   return true;
2269 }
2270 
2271 // Remove edges from "root" to each SafePoint at a backward branch.
2272 // They were inserted during parsing (see add_safepoint()) to make
2273 // infinite loops without calls or exceptions visible to root, i.e.,
2274 // useful.
2275 void Compile::remove_root_to_sfpts_edges(PhaseIterGVN& igvn) {
2276   Node *r = root();
2277   if (r != nullptr) {
2278     for (uint i = r->req(); i < r->len(); ++i) {
2279       Node *n = r->in(i);
2280       if (n != nullptr && n->is_SafePoint()) {
2281         r->rm_prec(i);
2282         if (n->outcnt() == 0) {
2283           igvn.remove_dead_node(n);
2284         }
2285         --i;
2286       }
2287     }
2288     // Parsing may have added top inputs to the root node (Path
2289     // leading to the Halt node proven dead). Make sure we get a
2290     // chance to clean them up.
2291     igvn._worklist.push(r);
2292     igvn.optimize();
2293   }
2294 }
2295 
2296 //------------------------------Optimize---------------------------------------
2297 // Given a graph, optimize it.
2298 void Compile::Optimize() {
2299   TracePhase tp(_t_optimizer);
2300 
2301 #ifndef PRODUCT
2302   if (env()->break_at_compile()) {
2303     BREAKPOINT;
2304   }
2305 
2306 #endif
2307 
2308   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
2309 #ifdef ASSERT
2310   bs->verify_gc_barriers(this, BarrierSetC2::BeforeOptimize);
2311 #endif
2312 
2313   ResourceMark rm;
2314 
2315   NOT_PRODUCT( verify_graph_edges(); )
2316 
2317   print_method(PHASE_AFTER_PARSING, 1);
2318 
2319  {
2320   // Iterative Global Value Numbering, including ideal transforms
2321   PhaseIterGVN igvn;
2322 #ifdef ASSERT
2323   _modified_nodes = new (comp_arena()) Unique_Node_List(comp_arena());
2324 #endif
2325   {
2326     TracePhase tp(_t_iterGVN);
2327     igvn.optimize();
2328   }
2329 
2330   if (failing())  return;
2331 
2332   print_method(PHASE_ITER_GVN1, 2);
2333 
2334   process_for_unstable_if_traps(igvn);
2335 
2336   if (failing())  return;
2337 
2338   inline_incrementally(igvn);
2339 
2340   print_method(PHASE_INCREMENTAL_INLINE, 2);
2341 
2342   if (failing())  return;
2343 
2344   if (eliminate_boxing()) {
2345     // Inline valueOf() methods now.
2346     inline_boxing_calls(igvn);
2347 
2348     if (failing())  return;
2349 
2350     if (AlwaysIncrementalInline || StressIncrementalInlining) {
2351       inline_incrementally(igvn);
2352     }
2353 
2354     print_method(PHASE_INCREMENTAL_BOXING_INLINE, 2);
2355 
2356     if (failing())  return;
2357   }
2358 
2359   // Remove the speculative part of types and clean up the graph from
2360   // the extra CastPP nodes whose only purpose is to carry them. Do
2361   // that early so that optimizations are not disrupted by the extra
2362   // CastPP nodes.
2363   remove_speculative_types(igvn);
2364 
2365   if (failing())  return;
2366 
2367   // No more new expensive nodes will be added to the list from here
2368   // so keep only the actual candidates for optimizations.
2369   cleanup_expensive_nodes(igvn);
2370 
2371   if (failing())  return;
2372 
2373   assert(EnableVectorSupport || !has_vbox_nodes(), "sanity");
2374   if (EnableVectorSupport && has_vbox_nodes()) {
2375     TracePhase tp(_t_vector);
2376     PhaseVector pv(igvn);
2377     pv.optimize_vector_boxes();
2378     if (failing())  return;
2379     print_method(PHASE_ITER_GVN_AFTER_VECTOR, 2);
2380   }
2381   assert(!has_vbox_nodes(), "sanity");
2382 
2383   if (!failing() && RenumberLiveNodes && live_nodes() + NodeLimitFudgeFactor < unique()) {
2384     Compile::TracePhase tp(_t_renumberLive);
2385     igvn_worklist()->ensure_empty(); // should be done with igvn
2386     {
2387       ResourceMark rm;
2388       PhaseRenumberLive prl(initial_gvn(), *igvn_worklist());
2389     }
2390     igvn.reset();
2391     igvn.optimize();
2392     if (failing()) return;
2393   }
2394 
2395   // Now that all inlining is over and no PhaseRemoveUseless will run, cut edge from root to loop
2396   // safepoints
2397   remove_root_to_sfpts_edges(igvn);
2398 
2399   if (failing())  return;
2400 
2401   if (has_loops()) {
2402     print_method(PHASE_BEFORE_LOOP_OPTS, 2);
2403   }
2404 
2405   // Perform escape analysis
2406   if (do_escape_analysis() && ConnectionGraph::has_candidates(this)) {
2407     if (has_loops()) {
2408       // Cleanup graph (remove dead nodes).
2409       TracePhase tp(_t_idealLoop);
2410       PhaseIdealLoop::optimize(igvn, LoopOptsMaxUnroll);
2411       if (failing())  return;
2412     }
2413     bool progress;
2414     print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
2415     do {
2416       ConnectionGraph::do_analysis(this, &igvn);
2417 
2418       if (failing())  return;
2419 
2420       int mcount = macro_count(); // Record number of allocations and locks before IGVN
2421 
2422       // Optimize out fields loads from scalar replaceable allocations.
2423       igvn.optimize();
2424       print_method(PHASE_ITER_GVN_AFTER_EA, 2);
2425 
2426       if (failing()) return;
2427 
2428       if (congraph() != nullptr && macro_count() > 0) {
2429         TracePhase tp(_t_macroEliminate);
2430         PhaseMacroExpand mexp(igvn);
2431         mexp.eliminate_macro_nodes();
2432         if (failing()) return;
2433         print_method(PHASE_AFTER_MACRO_ELIMINATION, 2);
2434 
2435         igvn.set_delay_transform(false);
2436         igvn.optimize();
2437         if (failing()) return;
2438 
2439         print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
2440       }
2441 
2442       ConnectionGraph::verify_ram_nodes(this, root());
2443       if (failing())  return;
2444 
2445       progress = do_iterative_escape_analysis() &&
2446                  (macro_count() < mcount) &&
2447                  ConnectionGraph::has_candidates(this);
2448       // Try again if candidates exist and made progress
2449       // by removing some allocations and/or locks.
2450     } while (progress);
2451   }
2452 
2453   // Loop transforms on the ideal graph.  Range Check Elimination,
2454   // peeling, unrolling, etc.
2455 
2456   // Set loop opts counter
2457   if((_loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
2458     {
2459       TracePhase tp(_t_idealLoop);
2460       PhaseIdealLoop::optimize(igvn, LoopOptsDefault);
2461       _loop_opts_cnt--;
2462       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP1, 2);
2463       if (failing())  return;
2464     }
2465     // Loop opts pass if partial peeling occurred in previous pass
2466     if(PartialPeelLoop && major_progress() && (_loop_opts_cnt > 0)) {
2467       TracePhase tp(_t_idealLoop);
2468       PhaseIdealLoop::optimize(igvn, LoopOptsSkipSplitIf);
2469       _loop_opts_cnt--;
2470       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP2, 2);
2471       if (failing())  return;
2472     }
2473     // Loop opts pass for loop-unrolling before CCP
2474     if(major_progress() && (_loop_opts_cnt > 0)) {
2475       TracePhase tp(_t_idealLoop);
2476       PhaseIdealLoop::optimize(igvn, LoopOptsSkipSplitIf);
2477       _loop_opts_cnt--;
2478       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP3, 2);
2479     }
2480     if (!failing()) {
2481       // Verify that last round of loop opts produced a valid graph
2482       PhaseIdealLoop::verify(igvn);
2483     }
2484   }
2485   if (failing())  return;
2486 
2487   // Conditional Constant Propagation;
2488   print_method(PHASE_BEFORE_CCP1, 2);
2489   PhaseCCP ccp( &igvn );
2490   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
2491   {
2492     TracePhase tp(_t_ccp);
2493     ccp.do_transform();
2494   }
2495   print_method(PHASE_CCP1, 2);
2496 
2497   assert( true, "Break here to ccp.dump_old2new_map()");
2498 
2499   // Iterative Global Value Numbering, including ideal transforms
2500   {
2501     TracePhase tp(_t_iterGVN2);
2502     igvn.reset_from_igvn(&ccp);
2503     igvn.optimize();
2504   }
2505   print_method(PHASE_ITER_GVN2, 2);
2506 
2507   if (failing())  return;
2508 
2509   // Loop transforms on the ideal graph.  Range Check Elimination,
2510   // peeling, unrolling, etc.
2511   if (!optimize_loops(igvn, LoopOptsDefault)) {
2512     return;
2513   }
2514 
2515   if (failing())  return;
2516 
2517   C->clear_major_progress(); // ensure that major progress is now clear
2518 
2519   process_for_post_loop_opts_igvn(igvn);
2520 
2521   process_for_merge_stores_igvn(igvn);
2522 
2523   if (failing())  return;
2524 
2525 #ifdef ASSERT
2526   bs->verify_gc_barriers(this, BarrierSetC2::BeforeMacroExpand);
2527 #endif
2528 
2529   {
2530     TracePhase tp(_t_macroExpand);
2531     print_method(PHASE_BEFORE_MACRO_EXPANSION, 3);
2532     PhaseMacroExpand  mex(igvn);
2533     // Do not allow new macro nodes once we start to eliminate and expand
2534     C->reset_allow_macro_nodes();
2535     // Last attempt to eliminate macro nodes before expand
2536     mex.eliminate_macro_nodes();
2537     if (failing()) {
2538       return;
2539     }
2540     mex.eliminate_opaque_looplimit_macro_nodes();
2541     if (failing()) {
2542       return;
2543     }
2544     print_method(PHASE_AFTER_MACRO_ELIMINATION, 2);
2545     if (mex.expand_macro_nodes()) {
2546       assert(failing(), "must bail out w/ explicit message");
2547       return;
2548     }
2549     print_method(PHASE_AFTER_MACRO_EXPANSION, 2);
2550   }
2551 
2552   {
2553     TracePhase tp(_t_barrierExpand);
2554     if (bs->expand_barriers(this, igvn)) {
2555       assert(failing(), "must bail out w/ explicit message");
2556       return;
2557     }
2558     print_method(PHASE_BARRIER_EXPANSION, 2);
2559   }
2560 
2561   if (C->max_vector_size() > 0) {
2562     C->optimize_logic_cones(igvn);
2563     igvn.optimize();
2564     if (failing()) return;
2565   }
2566 
2567   DEBUG_ONLY( _modified_nodes = nullptr; )
2568 
2569   assert(igvn._worklist.size() == 0, "not empty");
2570 
2571   assert(_late_inlines.length() == 0 || IncrementalInlineMH || IncrementalInlineVirtual, "not empty");
2572 
2573   if (_late_inlines.length() > 0) {
2574     // More opportunities to optimize virtual and MH calls.
2575     // Though it's maybe too late to perform inlining, strength-reducing them to direct calls is still an option.
2576     process_late_inline_calls_no_inline(igvn);
2577     if (failing())  return;
2578   }
2579  } // (End scope of igvn; run destructor if necessary for asserts.)
2580 
2581  check_no_dead_use();
2582 
2583  // We will never use the NodeHash table any more. Clear it so that final_graph_reshaping does not have
2584  // to remove hashes to unlock nodes for modifications.
2585  C->node_hash()->clear();
2586 
2587  // A method with only infinite loops has no edges entering loops from root
2588  {
2589    TracePhase tp(_t_graphReshaping);
2590    if (final_graph_reshaping()) {
2591      assert(failing(), "must bail out w/ explicit message");
2592      return;
2593    }
2594  }
2595 
2596  print_method(PHASE_OPTIMIZE_FINISHED, 2);
2597  DEBUG_ONLY(set_phase_optimize_finished();)
2598 }
2599 
2600 #ifdef ASSERT
2601 void Compile::check_no_dead_use() const {
2602   ResourceMark rm;
2603   Unique_Node_List wq;
2604   wq.push(root());
2605   for (uint i = 0; i < wq.size(); ++i) {
2606     Node* n = wq.at(i);
2607     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
2608       Node* u = n->fast_out(j);
2609       if (u->outcnt() == 0 && !u->is_Con()) {
2610         u->dump();
2611         fatal("no reachable node should have no use");
2612       }
2613       wq.push(u);
2614     }
2615   }
2616 }
2617 #endif
2618 
2619 void Compile::inline_vector_reboxing_calls() {
2620   if (C->_vector_reboxing_late_inlines.length() > 0) {
2621     _late_inlines_pos = C->_late_inlines.length();
2622     while (_vector_reboxing_late_inlines.length() > 0) {
2623       CallGenerator* cg = _vector_reboxing_late_inlines.pop();
2624       cg->do_late_inline();
2625       if (failing())  return;
2626       print_method(PHASE_INLINE_VECTOR_REBOX, 3, cg->call_node());
2627     }
2628     _vector_reboxing_late_inlines.trunc_to(0);
2629   }
2630 }
2631 
2632 bool Compile::has_vbox_nodes() {
2633   if (C->_vector_reboxing_late_inlines.length() > 0) {
2634     return true;
2635   }
2636   for (int macro_idx = C->macro_count() - 1; macro_idx >= 0; macro_idx--) {
2637     Node * n = C->macro_node(macro_idx);
2638     assert(n->is_macro(), "only macro nodes expected here");
2639     if (n->Opcode() == Op_VectorUnbox || n->Opcode() == Op_VectorBox || n->Opcode() == Op_VectorBoxAllocate) {
2640       return true;
2641     }
2642   }
2643   return false;
2644 }
2645 
2646 //---------------------------- Bitwise operation packing optimization ---------------------------
2647 
2648 static bool is_vector_unary_bitwise_op(Node* n) {
2649   return n->Opcode() == Op_XorV &&
2650          VectorNode::is_vector_bitwise_not_pattern(n);
2651 }
2652 
2653 static bool is_vector_binary_bitwise_op(Node* n) {
2654   switch (n->Opcode()) {
2655     case Op_AndV:
2656     case Op_OrV:
2657       return true;
2658 
2659     case Op_XorV:
2660       return !is_vector_unary_bitwise_op(n);
2661 
2662     default:
2663       return false;
2664   }
2665 }
2666 
2667 static bool is_vector_ternary_bitwise_op(Node* n) {
2668   return n->Opcode() == Op_MacroLogicV;
2669 }
2670 
2671 static bool is_vector_bitwise_op(Node* n) {
2672   return is_vector_unary_bitwise_op(n)  ||
2673          is_vector_binary_bitwise_op(n) ||
2674          is_vector_ternary_bitwise_op(n);
2675 }
2676 
2677 static bool is_vector_bitwise_cone_root(Node* n) {
2678   if (n->bottom_type()->isa_vectmask() || !is_vector_bitwise_op(n)) {
2679     return false;
2680   }
2681   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2682     if (is_vector_bitwise_op(n->fast_out(i))) {
2683       return false;
2684     }
2685   }
2686   return true;
2687 }
2688 
2689 static uint collect_unique_inputs(Node* n, Unique_Node_List& inputs) {
2690   uint cnt = 0;
2691   if (is_vector_bitwise_op(n)) {
2692     uint inp_cnt = n->is_predicated_vector() ? n->req()-1 : n->req();
2693     if (VectorNode::is_vector_bitwise_not_pattern(n)) {
2694       for (uint i = 1; i < inp_cnt; i++) {
2695         Node* in = n->in(i);
2696         bool skip = VectorNode::is_all_ones_vector(in);
2697         if (!skip && !inputs.member(in)) {
2698           inputs.push(in);
2699           cnt++;
2700         }
2701       }
2702       assert(cnt <= 1, "not unary");
2703     } else {
2704       uint last_req = inp_cnt;
2705       if (is_vector_ternary_bitwise_op(n)) {
2706         last_req = inp_cnt - 1; // skip last input
2707       }
2708       for (uint i = 1; i < last_req; i++) {
2709         Node* def = n->in(i);
2710         if (!inputs.member(def)) {
2711           inputs.push(def);
2712           cnt++;
2713         }
2714       }
2715     }
2716   } else { // not a bitwise operations
2717     if (!inputs.member(n)) {
2718       inputs.push(n);
2719       cnt++;
2720     }
2721   }
2722   return cnt;
2723 }
2724 
2725 void Compile::collect_logic_cone_roots(Unique_Node_List& list) {
2726   Unique_Node_List useful_nodes;
2727   C->identify_useful_nodes(useful_nodes);
2728 
2729   for (uint i = 0; i < useful_nodes.size(); i++) {
2730     Node* n = useful_nodes.at(i);
2731     if (is_vector_bitwise_cone_root(n)) {
2732       list.push(n);
2733     }
2734   }
2735 }
2736 
2737 Node* Compile::xform_to_MacroLogicV(PhaseIterGVN& igvn,
2738                                     const TypeVect* vt,
2739                                     Unique_Node_List& partition,
2740                                     Unique_Node_List& inputs) {
2741   assert(partition.size() == 2 || partition.size() == 3, "not supported");
2742   assert(inputs.size()    == 2 || inputs.size()    == 3, "not supported");
2743   assert(Matcher::match_rule_supported_vector(Op_MacroLogicV, vt->length(), vt->element_basic_type()), "not supported");
2744 
2745   Node* in1 = inputs.at(0);
2746   Node* in2 = inputs.at(1);
2747   Node* in3 = (inputs.size() == 3 ? inputs.at(2) : in2);
2748 
2749   uint func = compute_truth_table(partition, inputs);
2750 
2751   Node* pn = partition.at(partition.size() - 1);
2752   Node* mask = pn->is_predicated_vector() ? pn->in(pn->req()-1) : nullptr;
2753   return igvn.transform(MacroLogicVNode::make(igvn, in1, in2, in3, mask, func, vt));
2754 }
2755 
2756 static uint extract_bit(uint func, uint pos) {
2757   return (func & (1 << pos)) >> pos;
2758 }
2759 
2760 //
2761 //  A macro logic node represents a truth table. It has 4 inputs,
2762 //  First three inputs corresponds to 3 columns of a truth table
2763 //  and fourth input captures the logic function.
2764 //
2765 //  eg.  fn = (in1 AND in2) OR in3;
2766 //
2767 //      MacroNode(in1,in2,in3,fn)
2768 //
2769 //  -----------------
2770 //  in1 in2 in3  fn
2771 //  -----------------
2772 //  0    0   0    0
2773 //  0    0   1    1
2774 //  0    1   0    0
2775 //  0    1   1    1
2776 //  1    0   0    0
2777 //  1    0   1    1
2778 //  1    1   0    1
2779 //  1    1   1    1
2780 //
2781 
2782 uint Compile::eval_macro_logic_op(uint func, uint in1 , uint in2, uint in3) {
2783   int res = 0;
2784   for (int i = 0; i < 8; i++) {
2785     int bit1 = extract_bit(in1, i);
2786     int bit2 = extract_bit(in2, i);
2787     int bit3 = extract_bit(in3, i);
2788 
2789     int func_bit_pos = (bit1 << 2 | bit2 << 1 | bit3);
2790     int func_bit = extract_bit(func, func_bit_pos);
2791 
2792     res |= func_bit << i;
2793   }
2794   return res;
2795 }
2796 
2797 static uint eval_operand(Node* n, HashTable<Node*,uint>& eval_map) {
2798   assert(n != nullptr, "");
2799   assert(eval_map.contains(n), "absent");
2800   return *(eval_map.get(n));
2801 }
2802 
2803 static void eval_operands(Node* n,
2804                           uint& func1, uint& func2, uint& func3,
2805                           HashTable<Node*,uint>& eval_map) {
2806   assert(is_vector_bitwise_op(n), "");
2807 
2808   if (is_vector_unary_bitwise_op(n)) {
2809     Node* opnd = n->in(1);
2810     if (VectorNode::is_vector_bitwise_not_pattern(n) && VectorNode::is_all_ones_vector(opnd)) {
2811       opnd = n->in(2);
2812     }
2813     func1 = eval_operand(opnd, eval_map);
2814   } else if (is_vector_binary_bitwise_op(n)) {
2815     func1 = eval_operand(n->in(1), eval_map);
2816     func2 = eval_operand(n->in(2), eval_map);
2817   } else {
2818     assert(is_vector_ternary_bitwise_op(n), "unknown operation");
2819     func1 = eval_operand(n->in(1), eval_map);
2820     func2 = eval_operand(n->in(2), eval_map);
2821     func3 = eval_operand(n->in(3), eval_map);
2822   }
2823 }
2824 
2825 uint Compile::compute_truth_table(Unique_Node_List& partition, Unique_Node_List& inputs) {
2826   assert(inputs.size() <= 3, "sanity");
2827   ResourceMark rm;
2828   uint res = 0;
2829   HashTable<Node*,uint> eval_map;
2830 
2831   // Populate precomputed functions for inputs.
2832   // Each input corresponds to one column of 3 input truth-table.
2833   uint input_funcs[] = { 0xAA,   // (_, _, c) -> c
2834                          0xCC,   // (_, b, _) -> b
2835                          0xF0 }; // (a, _, _) -> a
2836   for (uint i = 0; i < inputs.size(); i++) {
2837     eval_map.put(inputs.at(i), input_funcs[2-i]);
2838   }
2839 
2840   for (uint i = 0; i < partition.size(); i++) {
2841     Node* n = partition.at(i);
2842 
2843     uint func1 = 0, func2 = 0, func3 = 0;
2844     eval_operands(n, func1, func2, func3, eval_map);
2845 
2846     switch (n->Opcode()) {
2847       case Op_OrV:
2848         assert(func3 == 0, "not binary");
2849         res = func1 | func2;
2850         break;
2851       case Op_AndV:
2852         assert(func3 == 0, "not binary");
2853         res = func1 & func2;
2854         break;
2855       case Op_XorV:
2856         if (VectorNode::is_vector_bitwise_not_pattern(n)) {
2857           assert(func2 == 0 && func3 == 0, "not unary");
2858           res = (~func1) & 0xFF;
2859         } else {
2860           assert(func3 == 0, "not binary");
2861           res = func1 ^ func2;
2862         }
2863         break;
2864       case Op_MacroLogicV:
2865         // Ordering of inputs may change during evaluation of sub-tree
2866         // containing MacroLogic node as a child node, thus a re-evaluation
2867         // makes sure that function is evaluated in context of current
2868         // inputs.
2869         res = eval_macro_logic_op(n->in(4)->get_int(), func1, func2, func3);
2870         break;
2871 
2872       default: assert(false, "not supported: %s", n->Name());
2873     }
2874     assert(res <= 0xFF, "invalid");
2875     eval_map.put(n, res);
2876   }
2877   return res;
2878 }
2879 
2880 // Criteria under which nodes gets packed into a macro logic node:-
2881 //  1) Parent and both child nodes are all unmasked or masked with
2882 //     same predicates.
2883 //  2) Masked parent can be packed with left child if it is predicated
2884 //     and both have same predicates.
2885 //  3) Masked parent can be packed with right child if its un-predicated
2886 //     or has matching predication condition.
2887 //  4) An unmasked parent can be packed with an unmasked child.
2888 bool Compile::compute_logic_cone(Node* n, Unique_Node_List& partition, Unique_Node_List& inputs) {
2889   assert(partition.size() == 0, "not empty");
2890   assert(inputs.size() == 0, "not empty");
2891   if (is_vector_ternary_bitwise_op(n)) {
2892     return false;
2893   }
2894 
2895   bool is_unary_op = is_vector_unary_bitwise_op(n);
2896   if (is_unary_op) {
2897     assert(collect_unique_inputs(n, inputs) == 1, "not unary");
2898     return false; // too few inputs
2899   }
2900 
2901   bool pack_left_child = true;
2902   bool pack_right_child = true;
2903 
2904   bool left_child_LOP = is_vector_bitwise_op(n->in(1));
2905   bool right_child_LOP = is_vector_bitwise_op(n->in(2));
2906 
2907   int left_child_input_cnt = 0;
2908   int right_child_input_cnt = 0;
2909 
2910   bool parent_is_predicated = n->is_predicated_vector();
2911   bool left_child_predicated = n->in(1)->is_predicated_vector();
2912   bool right_child_predicated = n->in(2)->is_predicated_vector();
2913 
2914   Node* parent_pred = parent_is_predicated ? n->in(n->req()-1) : nullptr;
2915   Node* left_child_pred = left_child_predicated ? n->in(1)->in(n->in(1)->req()-1) : nullptr;
2916   Node* right_child_pred = right_child_predicated ? n->in(1)->in(n->in(1)->req()-1) : nullptr;
2917 
2918   do {
2919     if (pack_left_child && left_child_LOP &&
2920         ((!parent_is_predicated && !left_child_predicated) ||
2921         ((parent_is_predicated && left_child_predicated &&
2922           parent_pred == left_child_pred)))) {
2923        partition.push(n->in(1));
2924        left_child_input_cnt = collect_unique_inputs(n->in(1), inputs);
2925     } else {
2926        inputs.push(n->in(1));
2927        left_child_input_cnt = 1;
2928     }
2929 
2930     if (pack_right_child && right_child_LOP &&
2931         (!right_child_predicated ||
2932          (right_child_predicated && parent_is_predicated &&
2933           parent_pred == right_child_pred))) {
2934        partition.push(n->in(2));
2935        right_child_input_cnt = collect_unique_inputs(n->in(2), inputs);
2936     } else {
2937        inputs.push(n->in(2));
2938        right_child_input_cnt = 1;
2939     }
2940 
2941     if (inputs.size() > 3) {
2942       assert(partition.size() > 0, "");
2943       inputs.clear();
2944       partition.clear();
2945       if (left_child_input_cnt > right_child_input_cnt) {
2946         pack_left_child = false;
2947       } else {
2948         pack_right_child = false;
2949       }
2950     } else {
2951       break;
2952     }
2953   } while(true);
2954 
2955   if(partition.size()) {
2956     partition.push(n);
2957   }
2958 
2959   return (partition.size() == 2 || partition.size() == 3) &&
2960          (inputs.size()    == 2 || inputs.size()    == 3);
2961 }
2962 
2963 void Compile::process_logic_cone_root(PhaseIterGVN &igvn, Node *n, VectorSet &visited) {
2964   assert(is_vector_bitwise_op(n), "not a root");
2965 
2966   visited.set(n->_idx);
2967 
2968   // 1) Do a DFS walk over the logic cone.
2969   for (uint i = 1; i < n->req(); i++) {
2970     Node* in = n->in(i);
2971     if (!visited.test(in->_idx) && is_vector_bitwise_op(in)) {
2972       process_logic_cone_root(igvn, in, visited);
2973     }
2974   }
2975 
2976   // 2) Bottom up traversal: Merge node[s] with
2977   // the parent to form macro logic node.
2978   Unique_Node_List partition;
2979   Unique_Node_List inputs;
2980   if (compute_logic_cone(n, partition, inputs)) {
2981     const TypeVect* vt = n->bottom_type()->is_vect();
2982     Node* pn = partition.at(partition.size() - 1);
2983     Node* mask = pn->is_predicated_vector() ? pn->in(pn->req()-1) : nullptr;
2984     if (mask == nullptr ||
2985         Matcher::match_rule_supported_vector_masked(Op_MacroLogicV, vt->length(), vt->element_basic_type())) {
2986       Node* macro_logic = xform_to_MacroLogicV(igvn, vt, partition, inputs);
2987       VectorNode::trace_new_vector(macro_logic, "MacroLogic");
2988       igvn.replace_node(n, macro_logic);
2989     }
2990   }
2991 }
2992 
2993 void Compile::optimize_logic_cones(PhaseIterGVN &igvn) {
2994   ResourceMark rm;
2995   if (Matcher::match_rule_supported(Op_MacroLogicV)) {
2996     Unique_Node_List list;
2997     collect_logic_cone_roots(list);
2998 
2999     while (list.size() > 0) {
3000       Node* n = list.pop();
3001       const TypeVect* vt = n->bottom_type()->is_vect();
3002       bool supported = Matcher::match_rule_supported_vector(Op_MacroLogicV, vt->length(), vt->element_basic_type());
3003       if (supported) {
3004         VectorSet visited(comp_arena());
3005         process_logic_cone_root(igvn, n, visited);
3006       }
3007     }
3008   }
3009 }
3010 
3011 //------------------------------Code_Gen---------------------------------------
3012 // Given a graph, generate code for it
3013 void Compile::Code_Gen() {
3014   if (failing()) {
3015     return;
3016   }
3017 
3018   // Perform instruction selection.  You might think we could reclaim Matcher
3019   // memory PDQ, but actually the Matcher is used in generating spill code.
3020   // Internals of the Matcher (including some VectorSets) must remain live
3021   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
3022   // set a bit in reclaimed memory.
3023 
3024   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
3025   // nodes.  Mapping is only valid at the root of each matched subtree.
3026   NOT_PRODUCT( verify_graph_edges(); )
3027 
3028   Matcher matcher;
3029   _matcher = &matcher;
3030   {
3031     TracePhase tp(_t_matcher);
3032     matcher.match();
3033     if (failing()) {
3034       return;
3035     }
3036   }
3037   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
3038   // nodes.  Mapping is only valid at the root of each matched subtree.
3039   NOT_PRODUCT( verify_graph_edges(); )
3040 
3041   // If you have too many nodes, or if matching has failed, bail out
3042   check_node_count(0, "out of nodes matching instructions");
3043   if (failing()) {
3044     return;
3045   }
3046 
3047   print_method(PHASE_MATCHING, 2);
3048 
3049   // Build a proper-looking CFG
3050   PhaseCFG cfg(node_arena(), root(), matcher);
3051   if (failing()) {
3052     return;
3053   }
3054   _cfg = &cfg;
3055   {
3056     TracePhase tp(_t_scheduler);
3057     bool success = cfg.do_global_code_motion();
3058     if (!success) {
3059       return;
3060     }
3061 
3062     print_method(PHASE_GLOBAL_CODE_MOTION, 2);
3063     NOT_PRODUCT( verify_graph_edges(); )
3064     cfg.verify();
3065     if (failing()) {
3066       return;
3067     }
3068   }
3069 
3070   PhaseChaitin regalloc(unique(), cfg, matcher, false);
3071   _regalloc = &regalloc;
3072   {
3073     TracePhase tp(_t_registerAllocation);
3074     // Perform register allocation.  After Chaitin, use-def chains are
3075     // no longer accurate (at spill code) and so must be ignored.
3076     // Node->LRG->reg mappings are still accurate.
3077     _regalloc->Register_Allocate();
3078 
3079     // Bail out if the allocator builds too many nodes
3080     if (failing()) {
3081       return;
3082     }
3083 
3084     print_method(PHASE_REGISTER_ALLOCATION, 2);
3085   }
3086 
3087   // Prior to register allocation we kept empty basic blocks in case the
3088   // the allocator needed a place to spill.  After register allocation we
3089   // are not adding any new instructions.  If any basic block is empty, we
3090   // can now safely remove it.
3091   {
3092     TracePhase tp(_t_blockOrdering);
3093     cfg.remove_empty_blocks();
3094     if (do_freq_based_layout()) {
3095       PhaseBlockLayout layout(cfg);
3096     } else {
3097       cfg.set_loop_alignment();
3098     }
3099     cfg.fixup_flow();
3100     cfg.remove_unreachable_blocks();
3101     cfg.verify_dominator_tree();
3102     print_method(PHASE_BLOCK_ORDERING, 3);
3103   }
3104 
3105   // Apply peephole optimizations
3106   if( OptoPeephole ) {
3107     TracePhase tp(_t_peephole);
3108     PhasePeephole peep( _regalloc, cfg);
3109     peep.do_transform();
3110     print_method(PHASE_PEEPHOLE, 3);
3111   }
3112 
3113   // Do late expand if CPU requires this.
3114   if (Matcher::require_postalloc_expand) {
3115     TracePhase tp(_t_postalloc_expand);
3116     cfg.postalloc_expand(_regalloc);
3117     print_method(PHASE_POSTALLOC_EXPAND, 3);
3118   }
3119 
3120 #ifdef ASSERT
3121   {
3122     CompilationMemoryStatistic::do_test_allocations();
3123     if (failing()) return;
3124   }
3125 #endif
3126 
3127   // Convert Nodes to instruction bits in a buffer
3128   {
3129     TracePhase tp(_t_output);
3130     PhaseOutput output;
3131     output.Output();
3132     if (failing())  return;
3133     output.install();
3134     print_method(PHASE_FINAL_CODE, 1); // Compile::_output is not null here
3135   }
3136 
3137   // He's dead, Jim.
3138   _cfg     = (PhaseCFG*)((intptr_t)0xdeadbeef);
3139   _regalloc = (PhaseChaitin*)((intptr_t)0xdeadbeef);
3140 }
3141 
3142 //------------------------------Final_Reshape_Counts---------------------------
3143 // This class defines counters to help identify when a method
3144 // may/must be executed using hardware with only 24-bit precision.
3145 struct Final_Reshape_Counts : public StackObj {
3146   int  _call_count;             // count non-inlined 'common' calls
3147   int  _float_count;            // count float ops requiring 24-bit precision
3148   int  _double_count;           // count double ops requiring more precision
3149   int  _java_call_count;        // count non-inlined 'java' calls
3150   int  _inner_loop_count;       // count loops which need alignment
3151   VectorSet _visited;           // Visitation flags
3152   Node_List _tests;             // Set of IfNodes & PCTableNodes
3153 
3154   Final_Reshape_Counts() :
3155     _call_count(0), _float_count(0), _double_count(0),
3156     _java_call_count(0), _inner_loop_count(0) { }
3157 
3158   void inc_call_count  () { _call_count  ++; }
3159   void inc_float_count () { _float_count ++; }
3160   void inc_double_count() { _double_count++; }
3161   void inc_java_call_count() { _java_call_count++; }
3162   void inc_inner_loop_count() { _inner_loop_count++; }
3163 
3164   int  get_call_count  () const { return _call_count  ; }
3165   int  get_float_count () const { return _float_count ; }
3166   int  get_double_count() const { return _double_count; }
3167   int  get_java_call_count() const { return _java_call_count; }
3168   int  get_inner_loop_count() const { return _inner_loop_count; }
3169 };
3170 
3171 //------------------------------final_graph_reshaping_impl----------------------
3172 // Implement items 1-5 from final_graph_reshaping below.
3173 void Compile::final_graph_reshaping_impl(Node *n, Final_Reshape_Counts& frc, Unique_Node_List& dead_nodes) {
3174 
3175   if ( n->outcnt() == 0 ) return; // dead node
3176   uint nop = n->Opcode();
3177 
3178   // Check for 2-input instruction with "last use" on right input.
3179   // Swap to left input.  Implements item (2).
3180   if( n->req() == 3 &&          // two-input instruction
3181       n->in(1)->outcnt() > 1 && // left use is NOT a last use
3182       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
3183       n->in(2)->outcnt() == 1 &&// right use IS a last use
3184       !n->in(2)->is_Con() ) {   // right use is not a constant
3185     // Check for commutative opcode
3186     switch( nop ) {
3187     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddL:
3188     case Op_MaxI:  case Op_MaxL:  case Op_MaxF:  case Op_MaxD:
3189     case Op_MinI:  case Op_MinL:  case Op_MinF:  case Op_MinD:
3190     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulL:
3191     case Op_AndL:  case Op_XorL:  case Op_OrL:
3192     case Op_AndI:  case Op_XorI:  case Op_OrI: {
3193       // Move "last use" input to left by swapping inputs
3194       n->swap_edges(1, 2);
3195       break;
3196     }
3197     default:
3198       break;
3199     }
3200   }
3201 
3202 #ifdef ASSERT
3203   if( n->is_Mem() ) {
3204     int alias_idx = get_alias_index(n->as_Mem()->adr_type());
3205     assert( n->in(0) != nullptr || alias_idx != Compile::AliasIdxRaw ||
3206             // oop will be recorded in oop map if load crosses safepoint
3207             (n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
3208                               LoadNode::is_immutable_value(n->in(MemNode::Address)))),
3209             "raw memory operations should have control edge");
3210   }
3211   if (n->is_MemBar()) {
3212     MemBarNode* mb = n->as_MemBar();
3213     if (mb->trailing_store() || mb->trailing_load_store()) {
3214       assert(mb->leading_membar()->trailing_membar() == mb, "bad membar pair");
3215       Node* mem = mb->in(MemBarNode::Precedent);
3216       assert((mb->trailing_store() && mem->is_Store() && mem->as_Store()->is_release()) ||
3217              (mb->trailing_load_store() && mem->is_LoadStore()), "missing mem op");
3218     } else if (mb->leading()) {
3219       assert(mb->trailing_membar()->leading_membar() == mb, "bad membar pair");
3220     }
3221   }
3222 #endif
3223   // Count FPU ops and common calls, implements item (3)
3224   final_graph_reshaping_main_switch(n, frc, nop, dead_nodes);
3225 
3226   // Collect CFG split points
3227   if (n->is_MultiBranch() && !n->is_RangeCheck()) {
3228     frc._tests.push(n);
3229   }
3230 }
3231 
3232 void Compile::handle_div_mod_op(Node* n, BasicType bt, bool is_unsigned) {
3233   if (!UseDivMod) {
3234     return;
3235   }
3236 
3237   // Check if "a % b" and "a / b" both exist
3238   Node* d = n->find_similar(Op_DivIL(bt, is_unsigned));
3239   if (d == nullptr) {
3240     return;
3241   }
3242 
3243   // Replace them with a fused divmod if supported
3244   if (Matcher::has_match_rule(Op_DivModIL(bt, is_unsigned))) {
3245     DivModNode* divmod = DivModNode::make(n, bt, is_unsigned);
3246     // If the divisor input for a Div (or Mod etc.) is not zero, then the control input of the Div is set to zero.
3247     // It could be that the divisor input is found not zero because its type is narrowed down by a CastII in the
3248     // subgraph for that input. Range check CastIIs are removed during final graph reshape. To preserve the dependency
3249     // carried by a CastII, precedence edges are added to the Div node. We need to transfer the precedence edges to the
3250     // DivMod node so the dependency is not lost.
3251     divmod->add_prec_from(n);
3252     divmod->add_prec_from(d);
3253     d->subsume_by(divmod->div_proj(), this);
3254     n->subsume_by(divmod->mod_proj(), this);
3255   } else {
3256     // Replace "a % b" with "a - ((a / b) * b)"
3257     Node* mult = MulNode::make(d, d->in(2), bt);
3258     Node* sub = SubNode::make(d->in(1), mult, bt);
3259     n->subsume_by(sub, this);
3260   }
3261 }
3262 
3263 void Compile::final_graph_reshaping_main_switch(Node* n, Final_Reshape_Counts& frc, uint nop, Unique_Node_List& dead_nodes) {
3264   switch( nop ) {
3265   // Count all float operations that may use FPU
3266   case Op_AddF:
3267   case Op_SubF:
3268   case Op_MulF:
3269   case Op_DivF:
3270   case Op_NegF:
3271   case Op_ModF:
3272   case Op_ConvI2F:
3273   case Op_ConF:
3274   case Op_CmpF:
3275   case Op_CmpF3:
3276   case Op_StoreF:
3277   case Op_LoadF:
3278   // case Op_ConvL2F: // longs are split into 32-bit halves
3279     frc.inc_float_count();
3280     break;
3281 
3282   case Op_ConvF2D:
3283   case Op_ConvD2F:
3284     frc.inc_float_count();
3285     frc.inc_double_count();
3286     break;
3287 
3288   // Count all double operations that may use FPU
3289   case Op_AddD:
3290   case Op_SubD:
3291   case Op_MulD:
3292   case Op_DivD:
3293   case Op_NegD:
3294   case Op_ModD:
3295   case Op_ConvI2D:
3296   case Op_ConvD2I:
3297   // case Op_ConvL2D: // handled by leaf call
3298   // case Op_ConvD2L: // handled by leaf call
3299   case Op_ConD:
3300   case Op_CmpD:
3301   case Op_CmpD3:
3302   case Op_StoreD:
3303   case Op_LoadD:
3304   case Op_LoadD_unaligned:
3305     frc.inc_double_count();
3306     break;
3307   case Op_Opaque1:              // Remove Opaque Nodes before matching
3308     n->subsume_by(n->in(1), this);
3309     break;
3310   case Op_CallLeafPure: {
3311     // If the pure call is not supported, then lower to a CallLeaf.
3312     if (!Matcher::match_rule_supported(Op_CallLeafPure)) {
3313       CallNode* call = n->as_Call();
3314       CallNode* new_call = new CallLeafNode(call->tf(), call->entry_point(),
3315                                             call->_name, TypeRawPtr::BOTTOM);
3316       new_call->init_req(TypeFunc::Control, call->in(TypeFunc::Control));
3317       new_call->init_req(TypeFunc::I_O, C->top());
3318       new_call->init_req(TypeFunc::Memory, C->top());
3319       new_call->init_req(TypeFunc::ReturnAdr, C->top());
3320       new_call->init_req(TypeFunc::FramePtr, C->top());
3321       for (unsigned int i = TypeFunc::Parms; i < call->tf()->domain()->cnt(); i++) {
3322         new_call->init_req(i, call->in(i));
3323       }
3324       n->subsume_by(new_call, this);
3325     }
3326     frc.inc_call_count();
3327     break;
3328   }
3329   case Op_CallStaticJava:
3330   case Op_CallJava:
3331   case Op_CallDynamicJava:
3332     frc.inc_java_call_count(); // Count java call site;
3333   case Op_CallRuntime:
3334   case Op_CallLeaf:
3335   case Op_CallLeafVector:
3336   case Op_CallLeafNoFP: {
3337     assert (n->is_Call(), "");
3338     CallNode *call = n->as_Call();
3339     // Count call sites where the FP mode bit would have to be flipped.
3340     // Do not count uncommon runtime calls:
3341     // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
3342     // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
3343     if (!call->is_CallStaticJava() || !call->as_CallStaticJava()->_name) {
3344       frc.inc_call_count();   // Count the call site
3345     } else {                  // See if uncommon argument is shared
3346       Node *n = call->in(TypeFunc::Parms);
3347       int nop = n->Opcode();
3348       // Clone shared simple arguments to uncommon calls, item (1).
3349       if (n->outcnt() > 1 &&
3350           !n->is_Proj() &&
3351           nop != Op_CreateEx &&
3352           nop != Op_CheckCastPP &&
3353           nop != Op_DecodeN &&
3354           nop != Op_DecodeNKlass &&
3355           !n->is_Mem() &&
3356           !n->is_Phi()) {
3357         Node *x = n->clone();
3358         call->set_req(TypeFunc::Parms, x);
3359       }
3360     }
3361     break;
3362   }
3363   case Op_StoreB:
3364   case Op_StoreC:
3365   case Op_StoreI:
3366   case Op_StoreL:
3367   case Op_CompareAndSwapB:
3368   case Op_CompareAndSwapS:
3369   case Op_CompareAndSwapI:
3370   case Op_CompareAndSwapL:
3371   case Op_CompareAndSwapP:
3372   case Op_CompareAndSwapN:
3373   case Op_WeakCompareAndSwapB:
3374   case Op_WeakCompareAndSwapS:
3375   case Op_WeakCompareAndSwapI:
3376   case Op_WeakCompareAndSwapL:
3377   case Op_WeakCompareAndSwapP:
3378   case Op_WeakCompareAndSwapN:
3379   case Op_CompareAndExchangeB:
3380   case Op_CompareAndExchangeS:
3381   case Op_CompareAndExchangeI:
3382   case Op_CompareAndExchangeL:
3383   case Op_CompareAndExchangeP:
3384   case Op_CompareAndExchangeN:
3385   case Op_GetAndAddS:
3386   case Op_GetAndAddB:
3387   case Op_GetAndAddI:
3388   case Op_GetAndAddL:
3389   case Op_GetAndSetS:
3390   case Op_GetAndSetB:
3391   case Op_GetAndSetI:
3392   case Op_GetAndSetL:
3393   case Op_GetAndSetP:
3394   case Op_GetAndSetN:
3395   case Op_StoreP:
3396   case Op_StoreN:
3397   case Op_StoreNKlass:
3398   case Op_LoadB:
3399   case Op_LoadUB:
3400   case Op_LoadUS:
3401   case Op_LoadI:
3402   case Op_LoadKlass:
3403   case Op_LoadNKlass:
3404   case Op_LoadL:
3405   case Op_LoadL_unaligned:
3406   case Op_LoadP:
3407   case Op_LoadN:
3408   case Op_LoadRange:
3409   case Op_LoadS:
3410     break;
3411 
3412   case Op_AddP: {               // Assert sane base pointers
3413     Node *addp = n->in(AddPNode::Address);
3414     assert(n->as_AddP()->address_input_has_same_base(), "Base pointers must match (addp %u)", addp->_idx );
3415 #ifdef _LP64
3416     if ((UseCompressedOops || UseCompressedClassPointers) &&
3417         addp->Opcode() == Op_ConP &&
3418         addp == n->in(AddPNode::Base) &&
3419         n->in(AddPNode::Offset)->is_Con()) {
3420       // If the transformation of ConP to ConN+DecodeN is beneficial depends
3421       // on the platform and on the compressed oops mode.
3422       // Use addressing with narrow klass to load with offset on x86.
3423       // Some platforms can use the constant pool to load ConP.
3424       // Do this transformation here since IGVN will convert ConN back to ConP.
3425       const Type* t = addp->bottom_type();
3426       bool is_oop   = t->isa_oopptr() != nullptr;
3427       bool is_klass = t->isa_klassptr() != nullptr;
3428 
3429       if ((is_oop   && UseCompressedOops          && Matcher::const_oop_prefer_decode()  ) ||
3430           (is_klass && UseCompressedClassPointers && Matcher::const_klass_prefer_decode() &&
3431            t->isa_klassptr()->exact_klass()->is_in_encoding_range())) {
3432         Node* nn = nullptr;
3433 
3434         int op = is_oop ? Op_ConN : Op_ConNKlass;
3435 
3436         // Look for existing ConN node of the same exact type.
3437         Node* r  = root();
3438         uint cnt = r->outcnt();
3439         for (uint i = 0; i < cnt; i++) {
3440           Node* m = r->raw_out(i);
3441           if (m!= nullptr && m->Opcode() == op &&
3442               m->bottom_type()->make_ptr() == t) {
3443             nn = m;
3444             break;
3445           }
3446         }
3447         if (nn != nullptr) {
3448           // Decode a narrow oop to match address
3449           // [R12 + narrow_oop_reg<<3 + offset]
3450           if (is_oop) {
3451             nn = new DecodeNNode(nn, t);
3452           } else {
3453             nn = new DecodeNKlassNode(nn, t);
3454           }
3455           // Check for succeeding AddP which uses the same Base.
3456           // Otherwise we will run into the assertion above when visiting that guy.
3457           for (uint i = 0; i < n->outcnt(); ++i) {
3458             Node *out_i = n->raw_out(i);
3459             if (out_i && out_i->is_AddP() && out_i->in(AddPNode::Base) == addp) {
3460               out_i->set_req(AddPNode::Base, nn);
3461 #ifdef ASSERT
3462               for (uint j = 0; j < out_i->outcnt(); ++j) {
3463                 Node *out_j = out_i->raw_out(j);
3464                 assert(out_j == nullptr || !out_j->is_AddP() || out_j->in(AddPNode::Base) != addp,
3465                        "more than 2 AddP nodes in a chain (out_j %u)", out_j->_idx);
3466               }
3467 #endif
3468             }
3469           }
3470           n->set_req(AddPNode::Base, nn);
3471           n->set_req(AddPNode::Address, nn);
3472           if (addp->outcnt() == 0) {
3473             addp->disconnect_inputs(this);
3474           }
3475         }
3476       }
3477     }
3478 #endif
3479     break;
3480   }
3481 
3482   case Op_CastPP: {
3483     // Remove CastPP nodes to gain more freedom during scheduling but
3484     // keep the dependency they encode as control or precedence edges
3485     // (if control is set already) on memory operations. Some CastPP
3486     // nodes don't have a control (don't carry a dependency): skip
3487     // those.
3488     if (n->in(0) != nullptr) {
3489       ResourceMark rm;
3490       Unique_Node_List wq;
3491       wq.push(n);
3492       for (uint next = 0; next < wq.size(); ++next) {
3493         Node *m = wq.at(next);
3494         for (DUIterator_Fast imax, i = m->fast_outs(imax); i < imax; i++) {
3495           Node* use = m->fast_out(i);
3496           if (use->is_Mem() || use->is_EncodeNarrowPtr()) {
3497             use->ensure_control_or_add_prec(n->in(0));
3498           } else {
3499             switch(use->Opcode()) {
3500             case Op_AddP:
3501             case Op_DecodeN:
3502             case Op_DecodeNKlass:
3503             case Op_CheckCastPP:
3504             case Op_CastPP:
3505               wq.push(use);
3506               break;
3507             }
3508           }
3509         }
3510       }
3511     }
3512     const bool is_LP64 = LP64_ONLY(true) NOT_LP64(false);
3513     if (is_LP64 && n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
3514       Node* in1 = n->in(1);
3515       const Type* t = n->bottom_type();
3516       Node* new_in1 = in1->clone();
3517       new_in1->as_DecodeN()->set_type(t);
3518 
3519       if (!Matcher::narrow_oop_use_complex_address()) {
3520         //
3521         // x86, ARM and friends can handle 2 adds in addressing mode
3522         // and Matcher can fold a DecodeN node into address by using
3523         // a narrow oop directly and do implicit null check in address:
3524         //
3525         // [R12 + narrow_oop_reg<<3 + offset]
3526         // NullCheck narrow_oop_reg
3527         //
3528         // On other platforms (Sparc) we have to keep new DecodeN node and
3529         // use it to do implicit null check in address:
3530         //
3531         // decode_not_null narrow_oop_reg, base_reg
3532         // [base_reg + offset]
3533         // NullCheck base_reg
3534         //
3535         // Pin the new DecodeN node to non-null path on these platform (Sparc)
3536         // to keep the information to which null check the new DecodeN node
3537         // corresponds to use it as value in implicit_null_check().
3538         //
3539         new_in1->set_req(0, n->in(0));
3540       }
3541 
3542       n->subsume_by(new_in1, this);
3543       if (in1->outcnt() == 0) {
3544         in1->disconnect_inputs(this);
3545       }
3546     } else {
3547       n->subsume_by(n->in(1), this);
3548       if (n->outcnt() == 0) {
3549         n->disconnect_inputs(this);
3550       }
3551     }
3552     break;
3553   }
3554   case Op_CastII: {
3555     n->as_CastII()->remove_range_check_cast(this);
3556     break;
3557   }
3558 #ifdef _LP64
3559   case Op_CmpP:
3560     // Do this transformation here to preserve CmpPNode::sub() and
3561     // other TypePtr related Ideal optimizations (for example, ptr nullness).
3562     if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
3563       Node* in1 = n->in(1);
3564       Node* in2 = n->in(2);
3565       if (!in1->is_DecodeNarrowPtr()) {
3566         in2 = in1;
3567         in1 = n->in(2);
3568       }
3569       assert(in1->is_DecodeNarrowPtr(), "sanity");
3570 
3571       Node* new_in2 = nullptr;
3572       if (in2->is_DecodeNarrowPtr()) {
3573         assert(in2->Opcode() == in1->Opcode(), "must be same node type");
3574         new_in2 = in2->in(1);
3575       } else if (in2->Opcode() == Op_ConP) {
3576         const Type* t = in2->bottom_type();
3577         if (t == TypePtr::NULL_PTR) {
3578           assert(in1->is_DecodeN(), "compare klass to null?");
3579           // Don't convert CmpP null check into CmpN if compressed
3580           // oops implicit null check is not generated.
3581           // This will allow to generate normal oop implicit null check.
3582           if (Matcher::gen_narrow_oop_implicit_null_checks())
3583             new_in2 = ConNode::make(TypeNarrowOop::NULL_PTR);
3584           //
3585           // This transformation together with CastPP transformation above
3586           // will generated code for implicit null checks for compressed oops.
3587           //
3588           // The original code after Optimize()
3589           //
3590           //    LoadN memory, narrow_oop_reg
3591           //    decode narrow_oop_reg, base_reg
3592           //    CmpP base_reg, nullptr
3593           //    CastPP base_reg // NotNull
3594           //    Load [base_reg + offset], val_reg
3595           //
3596           // after these transformations will be
3597           //
3598           //    LoadN memory, narrow_oop_reg
3599           //    CmpN narrow_oop_reg, nullptr
3600           //    decode_not_null narrow_oop_reg, base_reg
3601           //    Load [base_reg + offset], val_reg
3602           //
3603           // and the uncommon path (== nullptr) will use narrow_oop_reg directly
3604           // since narrow oops can be used in debug info now (see the code in
3605           // final_graph_reshaping_walk()).
3606           //
3607           // At the end the code will be matched to
3608           // on x86:
3609           //
3610           //    Load_narrow_oop memory, narrow_oop_reg
3611           //    Load [R12 + narrow_oop_reg<<3 + offset], val_reg
3612           //    NullCheck narrow_oop_reg
3613           //
3614           // and on sparc:
3615           //
3616           //    Load_narrow_oop memory, narrow_oop_reg
3617           //    decode_not_null narrow_oop_reg, base_reg
3618           //    Load [base_reg + offset], val_reg
3619           //    NullCheck base_reg
3620           //
3621         } else if (t->isa_oopptr()) {
3622           new_in2 = ConNode::make(t->make_narrowoop());
3623         } else if (t->isa_klassptr()) {
3624           ciKlass* klass = t->is_klassptr()->exact_klass();
3625           if (klass->is_in_encoding_range()) {
3626             new_in2 = ConNode::make(t->make_narrowklass());
3627           }
3628         }
3629       }
3630       if (new_in2 != nullptr) {
3631         Node* cmpN = new CmpNNode(in1->in(1), new_in2);
3632         n->subsume_by(cmpN, this);
3633         if (in1->outcnt() == 0) {
3634           in1->disconnect_inputs(this);
3635         }
3636         if (in2->outcnt() == 0) {
3637           in2->disconnect_inputs(this);
3638         }
3639       }
3640     }
3641     break;
3642 
3643   case Op_DecodeN:
3644   case Op_DecodeNKlass:
3645     assert(!n->in(1)->is_EncodeNarrowPtr(), "should be optimized out");
3646     // DecodeN could be pinned when it can't be fold into
3647     // an address expression, see the code for Op_CastPP above.
3648     assert(n->in(0) == nullptr || (UseCompressedOops && !Matcher::narrow_oop_use_complex_address()), "no control");
3649     break;
3650 
3651   case Op_EncodeP:
3652   case Op_EncodePKlass: {
3653     Node* in1 = n->in(1);
3654     if (in1->is_DecodeNarrowPtr()) {
3655       n->subsume_by(in1->in(1), this);
3656     } else if (in1->Opcode() == Op_ConP) {
3657       const Type* t = in1->bottom_type();
3658       if (t == TypePtr::NULL_PTR) {
3659         assert(t->isa_oopptr(), "null klass?");
3660         n->subsume_by(ConNode::make(TypeNarrowOop::NULL_PTR), this);
3661       } else if (t->isa_oopptr()) {
3662         n->subsume_by(ConNode::make(t->make_narrowoop()), this);
3663       } else if (t->isa_klassptr()) {
3664         ciKlass* klass = t->is_klassptr()->exact_klass();
3665         if (klass->is_in_encoding_range()) {
3666           n->subsume_by(ConNode::make(t->make_narrowklass()), this);
3667         } else {
3668           assert(false, "unencodable klass in ConP -> EncodeP");
3669           C->record_failure("unencodable klass in ConP -> EncodeP");
3670         }
3671       }
3672     }
3673     if (in1->outcnt() == 0) {
3674       in1->disconnect_inputs(this);
3675     }
3676     break;
3677   }
3678 
3679   case Op_Proj: {
3680     if (OptimizeStringConcat || IncrementalInline) {
3681       ProjNode* proj = n->as_Proj();
3682       if (proj->_is_io_use) {
3683         assert(proj->_con == TypeFunc::I_O || proj->_con == TypeFunc::Memory, "");
3684         // Separate projections were used for the exception path which
3685         // are normally removed by a late inline.  If it wasn't inlined
3686         // then they will hang around and should just be replaced with
3687         // the original one. Merge them.
3688         Node* non_io_proj = proj->in(0)->as_Multi()->proj_out_or_null(proj->_con, false /*is_io_use*/);
3689         if (non_io_proj  != nullptr) {
3690           proj->subsume_by(non_io_proj , this);
3691         }
3692       }
3693     }
3694     break;
3695   }
3696 
3697   case Op_Phi:
3698     if (n->as_Phi()->bottom_type()->isa_narrowoop() || n->as_Phi()->bottom_type()->isa_narrowklass()) {
3699       // The EncodeP optimization may create Phi with the same edges
3700       // for all paths. It is not handled well by Register Allocator.
3701       Node* unique_in = n->in(1);
3702       assert(unique_in != nullptr, "");
3703       uint cnt = n->req();
3704       for (uint i = 2; i < cnt; i++) {
3705         Node* m = n->in(i);
3706         assert(m != nullptr, "");
3707         if (unique_in != m)
3708           unique_in = nullptr;
3709       }
3710       if (unique_in != nullptr) {
3711         n->subsume_by(unique_in, this);
3712       }
3713     }
3714     break;
3715 
3716 #endif
3717 
3718   case Op_ModI:
3719     handle_div_mod_op(n, T_INT, false);
3720     break;
3721 
3722   case Op_ModL:
3723     handle_div_mod_op(n, T_LONG, false);
3724     break;
3725 
3726   case Op_UModI:
3727     handle_div_mod_op(n, T_INT, true);
3728     break;
3729 
3730   case Op_UModL:
3731     handle_div_mod_op(n, T_LONG, true);
3732     break;
3733 
3734   case Op_LoadVector:
3735   case Op_StoreVector:
3736 #ifdef ASSERT
3737     // Add VerifyVectorAlignment node between adr and load / store.
3738     if (VerifyAlignVector && Matcher::has_match_rule(Op_VerifyVectorAlignment)) {
3739       bool must_verify_alignment = n->is_LoadVector() ? n->as_LoadVector()->must_verify_alignment() :
3740                                                         n->as_StoreVector()->must_verify_alignment();
3741       if (must_verify_alignment) {
3742         jlong vector_width = n->is_LoadVector() ? n->as_LoadVector()->memory_size() :
3743                                                   n->as_StoreVector()->memory_size();
3744         // The memory access should be aligned to the vector width in bytes.
3745         // However, the underlying array is possibly less well aligned, but at least
3746         // to ObjectAlignmentInBytes. Hence, even if multiple arrays are accessed in
3747         // a loop we can expect at least the following alignment:
3748         jlong guaranteed_alignment = MIN2(vector_width, (jlong)ObjectAlignmentInBytes);
3749         assert(2 <= guaranteed_alignment && guaranteed_alignment <= 64, "alignment must be in range");
3750         assert(is_power_of_2(guaranteed_alignment), "alignment must be power of 2");
3751         // Create mask from alignment. e.g. 0b1000 -> 0b0111
3752         jlong mask = guaranteed_alignment - 1;
3753         Node* mask_con = ConLNode::make(mask);
3754         VerifyVectorAlignmentNode* va = new VerifyVectorAlignmentNode(n->in(MemNode::Address), mask_con);
3755         n->set_req(MemNode::Address, va);
3756       }
3757     }
3758 #endif
3759     break;
3760 
3761   case Op_LoadVectorGather:
3762   case Op_StoreVectorScatter:
3763   case Op_LoadVectorGatherMasked:
3764   case Op_StoreVectorScatterMasked:
3765   case Op_VectorCmpMasked:
3766   case Op_VectorMaskGen:
3767   case Op_LoadVectorMasked:
3768   case Op_StoreVectorMasked:
3769     break;
3770 
3771   case Op_AddReductionVI:
3772   case Op_AddReductionVL:
3773   case Op_AddReductionVF:
3774   case Op_AddReductionVD:
3775   case Op_MulReductionVI:
3776   case Op_MulReductionVL:
3777   case Op_MulReductionVF:
3778   case Op_MulReductionVD:
3779   case Op_MinReductionV:
3780   case Op_MaxReductionV:
3781   case Op_AndReductionV:
3782   case Op_OrReductionV:
3783   case Op_XorReductionV:
3784     break;
3785 
3786   case Op_PackB:
3787   case Op_PackS:
3788   case Op_PackI:
3789   case Op_PackF:
3790   case Op_PackL:
3791   case Op_PackD:
3792     if (n->req()-1 > 2) {
3793       // Replace many operand PackNodes with a binary tree for matching
3794       PackNode* p = (PackNode*) n;
3795       Node* btp = p->binary_tree_pack(1, n->req());
3796       n->subsume_by(btp, this);
3797     }
3798     break;
3799   case Op_Loop:
3800     assert(!n->as_Loop()->is_loop_nest_inner_loop() || _loop_opts_cnt == 0, "should have been turned into a counted loop");
3801   case Op_CountedLoop:
3802   case Op_LongCountedLoop:
3803   case Op_OuterStripMinedLoop:
3804     if (n->as_Loop()->is_inner_loop()) {
3805       frc.inc_inner_loop_count();
3806     }
3807     n->as_Loop()->verify_strip_mined(0);
3808     break;
3809   case Op_LShiftI:
3810   case Op_RShiftI:
3811   case Op_URShiftI:
3812   case Op_LShiftL:
3813   case Op_RShiftL:
3814   case Op_URShiftL:
3815     if (Matcher::need_masked_shift_count) {
3816       // The cpu's shift instructions don't restrict the count to the
3817       // lower 5/6 bits. We need to do the masking ourselves.
3818       Node* in2 = n->in(2);
3819       juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
3820       const TypeInt* t = in2->find_int_type();
3821       if (t != nullptr && t->is_con()) {
3822         juint shift = t->get_con();
3823         if (shift > mask) { // Unsigned cmp
3824           n->set_req(2, ConNode::make(TypeInt::make(shift & mask)));
3825         }
3826       } else {
3827         if (t == nullptr || t->_lo < 0 || t->_hi > (int)mask) {
3828           Node* shift = new AndINode(in2, ConNode::make(TypeInt::make(mask)));
3829           n->set_req(2, shift);
3830         }
3831       }
3832       if (in2->outcnt() == 0) { // Remove dead node
3833         in2->disconnect_inputs(this);
3834       }
3835     }
3836     break;
3837   case Op_MemBarStoreStore:
3838   case Op_MemBarRelease:
3839     // Break the link with AllocateNode: it is no longer useful and
3840     // confuses register allocation.
3841     if (n->req() > MemBarNode::Precedent) {
3842       n->set_req(MemBarNode::Precedent, top());
3843     }
3844     break;
3845   case Op_MemBarAcquire: {
3846     if (n->as_MemBar()->trailing_load() && n->req() > MemBarNode::Precedent) {
3847       // At parse time, the trailing MemBarAcquire for a volatile load
3848       // is created with an edge to the load. After optimizations,
3849       // that input may be a chain of Phis. If those phis have no
3850       // other use, then the MemBarAcquire keeps them alive and
3851       // register allocation can be confused.
3852       dead_nodes.push(n->in(MemBarNode::Precedent));
3853       n->set_req(MemBarNode::Precedent, top());
3854     }
3855     break;
3856   }
3857   case Op_Blackhole:
3858     break;
3859   case Op_RangeCheck: {
3860     RangeCheckNode* rc = n->as_RangeCheck();
3861     Node* iff = new IfNode(rc->in(0), rc->in(1), rc->_prob, rc->_fcnt);
3862     n->subsume_by(iff, this);
3863     frc._tests.push(iff);
3864     break;
3865   }
3866   case Op_ConvI2L: {
3867     if (!Matcher::convi2l_type_required) {
3868       // Code generation on some platforms doesn't need accurate
3869       // ConvI2L types. Widening the type can help remove redundant
3870       // address computations.
3871       n->as_Type()->set_type(TypeLong::INT);
3872       ResourceMark rm;
3873       Unique_Node_List wq;
3874       wq.push(n);
3875       for (uint next = 0; next < wq.size(); next++) {
3876         Node *m = wq.at(next);
3877 
3878         for(;;) {
3879           // Loop over all nodes with identical inputs edges as m
3880           Node* k = m->find_similar(m->Opcode());
3881           if (k == nullptr) {
3882             break;
3883           }
3884           // Push their uses so we get a chance to remove node made
3885           // redundant
3886           for (DUIterator_Fast imax, i = k->fast_outs(imax); i < imax; i++) {
3887             Node* u = k->fast_out(i);
3888             if (u->Opcode() == Op_LShiftL ||
3889                 u->Opcode() == Op_AddL ||
3890                 u->Opcode() == Op_SubL ||
3891                 u->Opcode() == Op_AddP) {
3892               wq.push(u);
3893             }
3894           }
3895           // Replace all nodes with identical edges as m with m
3896           k->subsume_by(m, this);
3897         }
3898       }
3899     }
3900     break;
3901   }
3902   case Op_CmpUL: {
3903     if (!Matcher::has_match_rule(Op_CmpUL)) {
3904       // No support for unsigned long comparisons
3905       ConINode* sign_pos = new ConINode(TypeInt::make(BitsPerLong - 1));
3906       Node* sign_bit_mask = new RShiftLNode(n->in(1), sign_pos);
3907       Node* orl = new OrLNode(n->in(1), sign_bit_mask);
3908       ConLNode* remove_sign_mask = new ConLNode(TypeLong::make(max_jlong));
3909       Node* andl = new AndLNode(orl, remove_sign_mask);
3910       Node* cmp = new CmpLNode(andl, n->in(2));
3911       n->subsume_by(cmp, this);
3912     }
3913     break;
3914   }
3915 #ifdef ASSERT
3916   case Op_ConNKlass: {
3917     const TypePtr* tp = n->as_Type()->type()->make_ptr();
3918     ciKlass* klass = tp->is_klassptr()->exact_klass();
3919     assert(klass->is_in_encoding_range(), "klass cannot be compressed");
3920     break;
3921   }
3922 #endif
3923   default:
3924     assert(!n->is_Call(), "");
3925     assert(!n->is_Mem(), "");
3926     assert(nop != Op_ProfileBoolean, "should be eliminated during IGVN");
3927     break;
3928   }
3929 }
3930 
3931 //------------------------------final_graph_reshaping_walk---------------------
3932 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
3933 // requires that the walk visits a node's inputs before visiting the node.
3934 void Compile::final_graph_reshaping_walk(Node_Stack& nstack, Node* root, Final_Reshape_Counts& frc, Unique_Node_List& dead_nodes) {
3935   Unique_Node_List sfpt;
3936 
3937   frc._visited.set(root->_idx); // first, mark node as visited
3938   uint cnt = root->req();
3939   Node *n = root;
3940   uint  i = 0;
3941   while (true) {
3942     if (i < cnt) {
3943       // Place all non-visited non-null inputs onto stack
3944       Node* m = n->in(i);
3945       ++i;
3946       if (m != nullptr && !frc._visited.test_set(m->_idx)) {
3947         if (m->is_SafePoint() && m->as_SafePoint()->jvms() != nullptr) {
3948           // compute worst case interpreter size in case of a deoptimization
3949           update_interpreter_frame_size(m->as_SafePoint()->jvms()->interpreter_frame_size());
3950 
3951           sfpt.push(m);
3952         }
3953         cnt = m->req();
3954         nstack.push(n, i); // put on stack parent and next input's index
3955         n = m;
3956         i = 0;
3957       }
3958     } else {
3959       // Now do post-visit work
3960       final_graph_reshaping_impl(n, frc, dead_nodes);
3961       if (nstack.is_empty())
3962         break;             // finished
3963       n = nstack.node();   // Get node from stack
3964       cnt = n->req();
3965       i = nstack.index();
3966       nstack.pop();        // Shift to the next node on stack
3967     }
3968   }
3969 
3970   // Skip next transformation if compressed oops are not used.
3971   if ((UseCompressedOops && !Matcher::gen_narrow_oop_implicit_null_checks()) ||
3972       (!UseCompressedOops && !UseCompressedClassPointers))
3973     return;
3974 
3975   // Go over safepoints nodes to skip DecodeN/DecodeNKlass nodes for debug edges.
3976   // It could be done for an uncommon traps or any safepoints/calls
3977   // if the DecodeN/DecodeNKlass node is referenced only in a debug info.
3978   while (sfpt.size() > 0) {
3979     n = sfpt.pop();
3980     JVMState *jvms = n->as_SafePoint()->jvms();
3981     assert(jvms != nullptr, "sanity");
3982     int start = jvms->debug_start();
3983     int end   = n->req();
3984     bool is_uncommon = (n->is_CallStaticJava() &&
3985                         n->as_CallStaticJava()->uncommon_trap_request() != 0);
3986     for (int j = start; j < end; j++) {
3987       Node* in = n->in(j);
3988       if (in->is_DecodeNarrowPtr()) {
3989         bool safe_to_skip = true;
3990         if (!is_uncommon ) {
3991           // Is it safe to skip?
3992           for (uint i = 0; i < in->outcnt(); i++) {
3993             Node* u = in->raw_out(i);
3994             if (!u->is_SafePoint() ||
3995                 (u->is_Call() && u->as_Call()->has_non_debug_use(n))) {
3996               safe_to_skip = false;
3997             }
3998           }
3999         }
4000         if (safe_to_skip) {
4001           n->set_req(j, in->in(1));
4002         }
4003         if (in->outcnt() == 0) {
4004           in->disconnect_inputs(this);
4005         }
4006       }
4007     }
4008   }
4009 }
4010 
4011 //------------------------------final_graph_reshaping--------------------------
4012 // Final Graph Reshaping.
4013 //
4014 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
4015 //     and not commoned up and forced early.  Must come after regular
4016 //     optimizations to avoid GVN undoing the cloning.  Clone constant
4017 //     inputs to Loop Phis; these will be split by the allocator anyways.
4018 //     Remove Opaque nodes.
4019 // (2) Move last-uses by commutative operations to the left input to encourage
4020 //     Intel update-in-place two-address operations and better register usage
4021 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
4022 //     calls canonicalizing them back.
4023 // (3) Count the number of double-precision FP ops, single-precision FP ops
4024 //     and call sites.  On Intel, we can get correct rounding either by
4025 //     forcing singles to memory (requires extra stores and loads after each
4026 //     FP bytecode) or we can set a rounding mode bit (requires setting and
4027 //     clearing the mode bit around call sites).  The mode bit is only used
4028 //     if the relative frequency of single FP ops to calls is low enough.
4029 //     This is a key transform for SPEC mpeg_audio.
4030 // (4) Detect infinite loops; blobs of code reachable from above but not
4031 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
4032 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
4033 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
4034 //     Detection is by looking for IfNodes where only 1 projection is
4035 //     reachable from below or CatchNodes missing some targets.
4036 // (5) Assert for insane oop offsets in debug mode.
4037 
4038 bool Compile::final_graph_reshaping() {
4039   // an infinite loop may have been eliminated by the optimizer,
4040   // in which case the graph will be empty.
4041   if (root()->req() == 1) {
4042     // Do not compile method that is only a trivial infinite loop,
4043     // since the content of the loop may have been eliminated.
4044     record_method_not_compilable("trivial infinite loop");
4045     return true;
4046   }
4047 
4048   // Expensive nodes have their control input set to prevent the GVN
4049   // from freely commoning them. There's no GVN beyond this point so
4050   // no need to keep the control input. We want the expensive nodes to
4051   // be freely moved to the least frequent code path by gcm.
4052   assert(OptimizeExpensiveOps || expensive_count() == 0, "optimization off but list non empty?");
4053   for (int i = 0; i < expensive_count(); i++) {
4054     _expensive_nodes.at(i)->set_req(0, nullptr);
4055   }
4056 
4057   Final_Reshape_Counts frc;
4058 
4059   // Visit everybody reachable!
4060   // Allocate stack of size C->live_nodes()/2 to avoid frequent realloc
4061   Node_Stack nstack(live_nodes() >> 1);
4062   Unique_Node_List dead_nodes;
4063   final_graph_reshaping_walk(nstack, root(), frc, dead_nodes);
4064 
4065   // Check for unreachable (from below) code (i.e., infinite loops).
4066   for( uint i = 0; i < frc._tests.size(); i++ ) {
4067     MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
4068     // Get number of CFG targets.
4069     // Note that PCTables include exception targets after calls.
4070     uint required_outcnt = n->required_outcnt();
4071     if (n->outcnt() != required_outcnt) {
4072       // Check for a few special cases.  Rethrow Nodes never take the
4073       // 'fall-thru' path, so expected kids is 1 less.
4074       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
4075         if (n->in(0)->in(0)->is_Call()) {
4076           CallNode* call = n->in(0)->in(0)->as_Call();
4077           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
4078             required_outcnt--;      // Rethrow always has 1 less kid
4079           } else if (call->req() > TypeFunc::Parms &&
4080                      call->is_CallDynamicJava()) {
4081             // Check for null receiver. In such case, the optimizer has
4082             // detected that the virtual call will always result in a null
4083             // pointer exception. The fall-through projection of this CatchNode
4084             // will not be populated.
4085             Node* arg0 = call->in(TypeFunc::Parms);
4086             if (arg0->is_Type() &&
4087                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
4088               required_outcnt--;
4089             }
4090           } else if (call->entry_point() == OptoRuntime::new_array_Java() ||
4091                      call->entry_point() == OptoRuntime::new_array_nozero_Java()) {
4092             // Check for illegal array length. In such case, the optimizer has
4093             // detected that the allocation attempt will always result in an
4094             // exception. There is no fall-through projection of this CatchNode .
4095             assert(call->is_CallStaticJava(), "static call expected");
4096             assert(call->req() == call->jvms()->endoff() + 1, "missing extra input");
4097             uint valid_length_test_input = call->req() - 1;
4098             Node* valid_length_test = call->in(valid_length_test_input);
4099             call->del_req(valid_length_test_input);
4100             if (valid_length_test->find_int_con(1) == 0) {
4101               required_outcnt--;
4102             }
4103             dead_nodes.push(valid_length_test);
4104             assert(n->outcnt() == required_outcnt, "malformed control flow");
4105             continue;
4106           }
4107         }
4108       }
4109 
4110       // Recheck with a better notion of 'required_outcnt'
4111       if (n->outcnt() != required_outcnt) {
4112         record_method_not_compilable("malformed control flow");
4113         return true;            // Not all targets reachable!
4114       }
4115     } else if (n->is_PCTable() && n->in(0) && n->in(0)->in(0) && n->in(0)->in(0)->is_Call()) {
4116       CallNode* call = n->in(0)->in(0)->as_Call();
4117       if (call->entry_point() == OptoRuntime::new_array_Java() ||
4118           call->entry_point() == OptoRuntime::new_array_nozero_Java()) {
4119         assert(call->is_CallStaticJava(), "static call expected");
4120         assert(call->req() == call->jvms()->endoff() + 1, "missing extra input");
4121         uint valid_length_test_input = call->req() - 1;
4122         dead_nodes.push(call->in(valid_length_test_input));
4123         call->del_req(valid_length_test_input); // valid length test useless now
4124       }
4125     }
4126     // Check that I actually visited all kids.  Unreached kids
4127     // must be infinite loops.
4128     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
4129       if (!frc._visited.test(n->fast_out(j)->_idx)) {
4130         record_method_not_compilable("infinite loop");
4131         return true;            // Found unvisited kid; must be unreach
4132       }
4133 
4134     // Here so verification code in final_graph_reshaping_walk()
4135     // always see an OuterStripMinedLoopEnd
4136     if (n->is_OuterStripMinedLoopEnd() || n->is_LongCountedLoopEnd()) {
4137       IfNode* init_iff = n->as_If();
4138       Node* iff = new IfNode(init_iff->in(0), init_iff->in(1), init_iff->_prob, init_iff->_fcnt);
4139       n->subsume_by(iff, this);
4140     }
4141   }
4142 
4143   while (dead_nodes.size() > 0) {
4144     Node* m = dead_nodes.pop();
4145     if (m->outcnt() == 0 && m != top()) {
4146       for (uint j = 0; j < m->req(); j++) {
4147         Node* in = m->in(j);
4148         if (in != nullptr) {
4149           dead_nodes.push(in);
4150         }
4151       }
4152       m->disconnect_inputs(this);
4153     }
4154   }
4155 
4156   set_java_calls(frc.get_java_call_count());
4157   set_inner_loops(frc.get_inner_loop_count());
4158 
4159   // No infinite loops, no reason to bail out.
4160   return false;
4161 }
4162 
4163 //-----------------------------too_many_traps----------------------------------
4164 // Report if there are too many traps at the current method and bci.
4165 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
4166 bool Compile::too_many_traps(ciMethod* method,
4167                              int bci,
4168                              Deoptimization::DeoptReason reason) {
4169   ciMethodData* md = method->method_data();
4170   if (md->is_empty()) {
4171     // Assume the trap has not occurred, or that it occurred only
4172     // because of a transient condition during start-up in the interpreter.
4173     return false;
4174   }
4175   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : nullptr;
4176   if (md->has_trap_at(bci, m, reason) != 0) {
4177     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
4178     // Also, if there are multiple reasons, or if there is no per-BCI record,
4179     // assume the worst.
4180     if (log())
4181       log()->elem("observe trap='%s' count='%d'",
4182                   Deoptimization::trap_reason_name(reason),
4183                   md->trap_count(reason));
4184     return true;
4185   } else {
4186     // Ignore method/bci and see if there have been too many globally.
4187     return too_many_traps(reason, md);
4188   }
4189 }
4190 
4191 // Less-accurate variant which does not require a method and bci.
4192 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
4193                              ciMethodData* logmd) {
4194   if (trap_count(reason) >= Deoptimization::per_method_trap_limit(reason)) {
4195     // Too many traps globally.
4196     // Note that we use cumulative trap_count, not just md->trap_count.
4197     if (log()) {
4198       int mcount = (logmd == nullptr)? -1: (int)logmd->trap_count(reason);
4199       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
4200                   Deoptimization::trap_reason_name(reason),
4201                   mcount, trap_count(reason));
4202     }
4203     return true;
4204   } else {
4205     // The coast is clear.
4206     return false;
4207   }
4208 }
4209 
4210 //--------------------------too_many_recompiles--------------------------------
4211 // Report if there are too many recompiles at the current method and bci.
4212 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
4213 // Is not eager to return true, since this will cause the compiler to use
4214 // Action_none for a trap point, to avoid too many recompilations.
4215 bool Compile::too_many_recompiles(ciMethod* method,
4216                                   int bci,
4217                                   Deoptimization::DeoptReason reason) {
4218   ciMethodData* md = method->method_data();
4219   if (md->is_empty()) {
4220     // Assume the trap has not occurred, or that it occurred only
4221     // because of a transient condition during start-up in the interpreter.
4222     return false;
4223   }
4224   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
4225   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
4226   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
4227   Deoptimization::DeoptReason per_bc_reason
4228     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
4229   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : nullptr;
4230   if ((per_bc_reason == Deoptimization::Reason_none
4231        || md->has_trap_at(bci, m, reason) != 0)
4232       // The trap frequency measure we care about is the recompile count:
4233       && md->trap_recompiled_at(bci, m)
4234       && md->overflow_recompile_count() >= bc_cutoff) {
4235     // Do not emit a trap here if it has already caused recompilations.
4236     // Also, if there are multiple reasons, or if there is no per-BCI record,
4237     // assume the worst.
4238     if (log())
4239       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
4240                   Deoptimization::trap_reason_name(reason),
4241                   md->trap_count(reason),
4242                   md->overflow_recompile_count());
4243     return true;
4244   } else if (trap_count(reason) != 0
4245              && decompile_count() >= m_cutoff) {
4246     // Too many recompiles globally, and we have seen this sort of trap.
4247     // Use cumulative decompile_count, not just md->decompile_count.
4248     if (log())
4249       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
4250                   Deoptimization::trap_reason_name(reason),
4251                   md->trap_count(reason), trap_count(reason),
4252                   md->decompile_count(), decompile_count());
4253     return true;
4254   } else {
4255     // The coast is clear.
4256     return false;
4257   }
4258 }
4259 
4260 // Compute when not to trap. Used by matching trap based nodes and
4261 // NullCheck optimization.
4262 void Compile::set_allowed_deopt_reasons() {
4263   _allowed_reasons = 0;
4264   if (is_method_compilation()) {
4265     for (int rs = (int)Deoptimization::Reason_none+1; rs < Compile::trapHistLength; rs++) {
4266       assert(rs < BitsPerInt, "recode bit map");
4267       if (!too_many_traps((Deoptimization::DeoptReason) rs)) {
4268         _allowed_reasons |= nth_bit(rs);
4269       }
4270     }
4271   }
4272 }
4273 
4274 bool Compile::needs_clinit_barrier(ciMethod* method, ciMethod* accessing_method) {
4275   return method->is_static() && needs_clinit_barrier(method->holder(), accessing_method);
4276 }
4277 
4278 bool Compile::needs_clinit_barrier(ciField* field, ciMethod* accessing_method) {
4279   return field->is_static() && needs_clinit_barrier(field->holder(), accessing_method);
4280 }
4281 
4282 bool Compile::needs_clinit_barrier(ciInstanceKlass* holder, ciMethod* accessing_method) {
4283   if (holder->is_initialized()) {
4284     return false;
4285   }
4286   if (holder->is_being_initialized()) {
4287     if (accessing_method->holder() == holder) {
4288       // Access inside a class. The barrier can be elided when access happens in <clinit>,
4289       // <init>, or a static method. In all those cases, there was an initialization
4290       // barrier on the holder klass passed.
4291       if (accessing_method->is_static_initializer() ||
4292           accessing_method->is_object_initializer() ||
4293           accessing_method->is_static()) {
4294         return false;
4295       }
4296     } else if (accessing_method->holder()->is_subclass_of(holder)) {
4297       // Access from a subclass. The barrier can be elided only when access happens in <clinit>.
4298       // In case of <init> or a static method, the barrier is on the subclass is not enough:
4299       // child class can become fully initialized while its parent class is still being initialized.
4300       if (accessing_method->is_static_initializer()) {
4301         return false;
4302       }
4303     }
4304     ciMethod* root = method(); // the root method of compilation
4305     if (root != accessing_method) {
4306       return needs_clinit_barrier(holder, root); // check access in the context of compilation root
4307     }
4308   }
4309   return true;
4310 }
4311 
4312 #ifndef PRODUCT
4313 //------------------------------verify_bidirectional_edges---------------------
4314 // For each input edge to a node (ie - for each Use-Def edge), verify that
4315 // there is a corresponding Def-Use edge.
4316 void Compile::verify_bidirectional_edges(Unique_Node_List& visited, const Unique_Node_List* root_and_safepoints) const {
4317   // Allocate stack of size C->live_nodes()/16 to avoid frequent realloc
4318   uint stack_size = live_nodes() >> 4;
4319   Node_List nstack(MAX2(stack_size, (uint) OptoNodeListSize));
4320   if (root_and_safepoints != nullptr) {
4321     assert(root_and_safepoints->member(_root), "root is not in root_and_safepoints");
4322     for (uint i = 0, limit = root_and_safepoints->size(); i < limit; i++) {
4323       Node* root_or_safepoint = root_and_safepoints->at(i);
4324       // If the node is a safepoint, let's check if it still has a control input
4325       // Lack of control input signifies that this node was killed by CCP or
4326       // recursively by remove_globally_dead_node and it shouldn't be a starting
4327       // point.
4328       if (!root_or_safepoint->is_SafePoint() || root_or_safepoint->in(0) != nullptr) {
4329         nstack.push(root_or_safepoint);
4330       }
4331     }
4332   } else {
4333     nstack.push(_root);
4334   }
4335 
4336   while (nstack.size() > 0) {
4337     Node* n = nstack.pop();
4338     if (visited.member(n)) {
4339       continue;
4340     }
4341     visited.push(n);
4342 
4343     // Walk over all input edges, checking for correspondence
4344     uint length = n->len();
4345     for (uint i = 0; i < length; i++) {
4346       Node* in = n->in(i);
4347       if (in != nullptr && !visited.member(in)) {
4348         nstack.push(in); // Put it on stack
4349       }
4350       if (in != nullptr && !in->is_top()) {
4351         // Count instances of `next`
4352         int cnt = 0;
4353         for (uint idx = 0; idx < in->_outcnt; idx++) {
4354           if (in->_out[idx] == n) {
4355             cnt++;
4356           }
4357         }
4358         assert(cnt > 0, "Failed to find Def-Use edge.");
4359         // Check for duplicate edges
4360         // walk the input array downcounting the input edges to n
4361         for (uint j = 0; j < length; j++) {
4362           if (n->in(j) == in) {
4363             cnt--;
4364           }
4365         }
4366         assert(cnt == 0, "Mismatched edge count.");
4367       } else if (in == nullptr) {
4368         assert(i == 0 || i >= n->req() ||
4369                n->is_Region() || n->is_Phi() || n->is_ArrayCopy() ||
4370                (n->is_Unlock() && i == (n->req() - 1)) ||
4371                (n->is_MemBar() && i == 5), // the precedence edge to a membar can be removed during macro node expansion
4372               "only region, phi, arraycopy, unlock or membar nodes have null data edges");
4373       } else {
4374         assert(in->is_top(), "sanity");
4375         // Nothing to check.
4376       }
4377     }
4378   }
4379 }
4380 
4381 //------------------------------verify_graph_edges---------------------------
4382 // Walk the Graph and verify that there is a one-to-one correspondence
4383 // between Use-Def edges and Def-Use edges in the graph.
4384 void Compile::verify_graph_edges(bool no_dead_code, const Unique_Node_List* root_and_safepoints) const {
4385   if (VerifyGraphEdges) {
4386     Unique_Node_List visited;
4387 
4388     // Call graph walk to check edges
4389     verify_bidirectional_edges(visited, root_and_safepoints);
4390     if (no_dead_code) {
4391       // Now make sure that no visited node is used by an unvisited node.
4392       bool dead_nodes = false;
4393       Unique_Node_List checked;
4394       while (visited.size() > 0) {
4395         Node* n = visited.pop();
4396         checked.push(n);
4397         for (uint i = 0; i < n->outcnt(); i++) {
4398           Node* use = n->raw_out(i);
4399           if (checked.member(use))  continue;  // already checked
4400           if (visited.member(use))  continue;  // already in the graph
4401           if (use->is_Con())        continue;  // a dead ConNode is OK
4402           // At this point, we have found a dead node which is DU-reachable.
4403           if (!dead_nodes) {
4404             tty->print_cr("*** Dead nodes reachable via DU edges:");
4405             dead_nodes = true;
4406           }
4407           use->dump(2);
4408           tty->print_cr("---");
4409           checked.push(use);  // No repeats; pretend it is now checked.
4410         }
4411       }
4412       assert(!dead_nodes, "using nodes must be reachable from root");
4413     }
4414   }
4415 }
4416 #endif
4417 
4418 // The Compile object keeps track of failure reasons separately from the ciEnv.
4419 // This is required because there is not quite a 1-1 relation between the
4420 // ciEnv and its compilation task and the Compile object.  Note that one
4421 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
4422 // to backtrack and retry without subsuming loads.  Other than this backtracking
4423 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
4424 // by the logic in C2Compiler.
4425 void Compile::record_failure(const char* reason DEBUG_ONLY(COMMA bool allow_multiple_failures)) {
4426   if (log() != nullptr) {
4427     log()->elem("failure reason='%s' phase='compile'", reason);
4428   }
4429   if (_failure_reason.get() == nullptr) {
4430     // Record the first failure reason.
4431     _failure_reason.set(reason);
4432     if (CaptureBailoutInformation) {
4433       _first_failure_details = new CompilationFailureInfo(reason);
4434     }
4435   } else {
4436     assert(!StressBailout || allow_multiple_failures, "should have handled previous failure.");
4437   }
4438 
4439   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
4440     C->print_method(PHASE_FAILURE, 1);
4441   }
4442   _root = nullptr;  // flush the graph, too
4443 }
4444 
4445 Compile::TracePhase::TracePhase(const char* name, PhaseTraceId id)
4446   : TraceTime(name, &Phase::timers[id], CITime, CITimeVerbose),
4447     _compile(Compile::current()),
4448     _log(nullptr),
4449     _dolog(CITimeVerbose)
4450 {
4451   assert(_compile != nullptr, "sanity check");
4452   assert(id != PhaseTraceId::_t_none, "Don't use none");
4453   if (_dolog) {
4454     _log = _compile->log();
4455   }
4456   if (_log != nullptr) {
4457     _log->begin_head("phase name='%s' nodes='%d' live='%d'", phase_name(), _compile->unique(), _compile->live_nodes());
4458     _log->stamp();
4459     _log->end_head();
4460   }
4461 
4462   // Inform memory statistic, if enabled
4463   if (CompilationMemoryStatistic::enabled()) {
4464     CompilationMemoryStatistic::on_phase_start((int)id, name);
4465   }
4466 }
4467 
4468 Compile::TracePhase::TracePhase(PhaseTraceId id)
4469   : TracePhase(Phase::get_phase_trace_id_text(id), id) {}
4470 
4471 Compile::TracePhase::~TracePhase() {
4472 
4473   // Inform memory statistic, if enabled
4474   if (CompilationMemoryStatistic::enabled()) {
4475     CompilationMemoryStatistic::on_phase_end();
4476   }
4477 
4478   if (_compile->failing_internal()) {
4479     if (_log != nullptr) {
4480       _log->done("phase");
4481     }
4482     return; // timing code, not stressing bailouts.
4483   }
4484 #ifdef ASSERT
4485   if (PrintIdealNodeCount) {
4486     tty->print_cr("phase name='%s' nodes='%d' live='%d' live_graph_walk='%d'",
4487                   phase_name(), _compile->unique(), _compile->live_nodes(), _compile->count_live_nodes_by_graph_walk());
4488   }
4489 
4490   if (VerifyIdealNodeCount) {
4491     _compile->print_missing_nodes();
4492   }
4493 #endif
4494 
4495   if (_log != nullptr) {
4496     _log->done("phase name='%s' nodes='%d' live='%d'", phase_name(), _compile->unique(), _compile->live_nodes());
4497   }
4498 }
4499 
4500 //----------------------------static_subtype_check-----------------------------
4501 // Shortcut important common cases when superklass is exact:
4502 // (0) superklass is java.lang.Object (can occur in reflective code)
4503 // (1) subklass is already limited to a subtype of superklass => always ok
4504 // (2) subklass does not overlap with superklass => always fail
4505 // (3) superklass has NO subtypes and we can check with a simple compare.
4506 Compile::SubTypeCheckResult Compile::static_subtype_check(const TypeKlassPtr* superk, const TypeKlassPtr* subk, bool skip) {
4507   if (skip) {
4508     return SSC_full_test;       // Let caller generate the general case.
4509   }
4510 
4511   if (subk->is_java_subtype_of(superk)) {
4512     return SSC_always_true; // (0) and (1)  this test cannot fail
4513   }
4514 
4515   if (!subk->maybe_java_subtype_of(superk)) {
4516     return SSC_always_false; // (2) true path dead; no dynamic test needed
4517   }
4518 
4519   const Type* superelem = superk;
4520   if (superk->isa_aryklassptr()) {
4521     int ignored;
4522     superelem = superk->is_aryklassptr()->base_element_type(ignored);
4523   }
4524 
4525   if (superelem->isa_instklassptr()) {
4526     ciInstanceKlass* ik = superelem->is_instklassptr()->instance_klass();
4527     if (!ik->has_subklass()) {
4528       if (!ik->is_final()) {
4529         // Add a dependency if there is a chance of a later subclass.
4530         dependencies()->assert_leaf_type(ik);
4531       }
4532       if (!superk->maybe_java_subtype_of(subk)) {
4533         return SSC_always_false;
4534       }
4535       return SSC_easy_test;     // (3) caller can do a simple ptr comparison
4536     }
4537   } else {
4538     // A primitive array type has no subtypes.
4539     return SSC_easy_test;       // (3) caller can do a simple ptr comparison
4540   }
4541 
4542   return SSC_full_test;
4543 }
4544 
4545 Node* Compile::conv_I2X_index(PhaseGVN* phase, Node* idx, const TypeInt* sizetype, Node* ctrl) {
4546 #ifdef _LP64
4547   // The scaled index operand to AddP must be a clean 64-bit value.
4548   // Java allows a 32-bit int to be incremented to a negative
4549   // value, which appears in a 64-bit register as a large
4550   // positive number.  Using that large positive number as an
4551   // operand in pointer arithmetic has bad consequences.
4552   // On the other hand, 32-bit overflow is rare, and the possibility
4553   // can often be excluded, if we annotate the ConvI2L node with
4554   // a type assertion that its value is known to be a small positive
4555   // number.  (The prior range check has ensured this.)
4556   // This assertion is used by ConvI2LNode::Ideal.
4557   int index_max = max_jint - 1;  // array size is max_jint, index is one less
4558   if (sizetype != nullptr && sizetype->_hi > 0) {
4559     index_max = sizetype->_hi - 1;
4560   }
4561   const TypeInt* iidxtype = TypeInt::make(0, index_max, Type::WidenMax);
4562   idx = constrained_convI2L(phase, idx, iidxtype, ctrl);
4563 #endif
4564   return idx;
4565 }
4566 
4567 // Convert integer value to a narrowed long type dependent on ctrl (for example, a range check)
4568 Node* Compile::constrained_convI2L(PhaseGVN* phase, Node* value, const TypeInt* itype, Node* ctrl, bool carry_dependency) {
4569   if (ctrl != nullptr) {
4570     // Express control dependency by a CastII node with a narrow type.
4571     // Make the CastII node dependent on the control input to prevent the narrowed ConvI2L
4572     // node from floating above the range check during loop optimizations. Otherwise, the
4573     // ConvI2L node may be eliminated independently of the range check, causing the data path
4574     // to become TOP while the control path is still there (although it's unreachable).
4575     value = new CastIINode(ctrl, value, itype, carry_dependency ? ConstraintCastNode::DependencyType::NonFloatingNarrowing : ConstraintCastNode::DependencyType::FloatingNarrowing, true /* range check dependency */);
4576     value = phase->transform(value);
4577   }
4578   const TypeLong* ltype = TypeLong::make(itype->_lo, itype->_hi, itype->_widen);
4579   return phase->transform(new ConvI2LNode(value, ltype));
4580 }
4581 
4582 void Compile::dump_print_inlining() {
4583   inline_printer()->print_on(tty);
4584 }
4585 
4586 void Compile::log_late_inline(CallGenerator* cg) {
4587   if (log() != nullptr) {
4588     log()->head("late_inline method='%d' inline_id='" JLONG_FORMAT "'", log()->identify(cg->method()),
4589                 cg->unique_id());
4590     JVMState* p = cg->call_node()->jvms();
4591     while (p != nullptr) {
4592       log()->elem("jvms bci='%d' method='%d'", p->bci(), log()->identify(p->method()));
4593       p = p->caller();
4594     }
4595     log()->tail("late_inline");
4596   }
4597 }
4598 
4599 void Compile::log_late_inline_failure(CallGenerator* cg, const char* msg) {
4600   log_late_inline(cg);
4601   if (log() != nullptr) {
4602     log()->inline_fail(msg);
4603   }
4604 }
4605 
4606 void Compile::log_inline_id(CallGenerator* cg) {
4607   if (log() != nullptr) {
4608     // The LogCompilation tool needs a unique way to identify late
4609     // inline call sites. This id must be unique for this call site in
4610     // this compilation. Try to have it unique across compilations as
4611     // well because it can be convenient when grepping through the log
4612     // file.
4613     // Distinguish OSR compilations from others in case CICountOSR is
4614     // on.
4615     jlong id = ((jlong)unique()) + (((jlong)compile_id()) << 33) + (CICountOSR && is_osr_compilation() ? ((jlong)1) << 32 : 0);
4616     cg->set_unique_id(id);
4617     log()->elem("inline_id id='" JLONG_FORMAT "'", id);
4618   }
4619 }
4620 
4621 void Compile::log_inline_failure(const char* msg) {
4622   if (C->log() != nullptr) {
4623     C->log()->inline_fail(msg);
4624   }
4625 }
4626 
4627 
4628 // Dump inlining replay data to the stream.
4629 // Don't change thread state and acquire any locks.
4630 void Compile::dump_inline_data(outputStream* out) {
4631   InlineTree* inl_tree = ilt();
4632   if (inl_tree != nullptr) {
4633     out->print(" inline %d", inl_tree->count());
4634     inl_tree->dump_replay_data(out);
4635   }
4636 }
4637 
4638 void Compile::dump_inline_data_reduced(outputStream* out) {
4639   assert(ReplayReduce, "");
4640 
4641   InlineTree* inl_tree = ilt();
4642   if (inl_tree == nullptr) {
4643     return;
4644   }
4645   // Enable iterative replay file reduction
4646   // Output "compile" lines for depth 1 subtrees,
4647   // simulating that those trees were compiled
4648   // instead of inlined.
4649   for (int i = 0; i < inl_tree->subtrees().length(); ++i) {
4650     InlineTree* sub = inl_tree->subtrees().at(i);
4651     if (sub->inline_level() != 1) {
4652       continue;
4653     }
4654 
4655     ciMethod* method = sub->method();
4656     int entry_bci = -1;
4657     int comp_level = env()->task()->comp_level();
4658     out->print("compile ");
4659     method->dump_name_as_ascii(out);
4660     out->print(" %d %d", entry_bci, comp_level);
4661     out->print(" inline %d", sub->count());
4662     sub->dump_replay_data(out, -1);
4663     out->cr();
4664   }
4665 }
4666 
4667 int Compile::cmp_expensive_nodes(Node* n1, Node* n2) {
4668   if (n1->Opcode() < n2->Opcode())      return -1;
4669   else if (n1->Opcode() > n2->Opcode()) return 1;
4670 
4671   assert(n1->req() == n2->req(), "can't compare %s nodes: n1->req() = %d, n2->req() = %d", NodeClassNames[n1->Opcode()], n1->req(), n2->req());
4672   for (uint i = 1; i < n1->req(); i++) {
4673     if (n1->in(i) < n2->in(i))      return -1;
4674     else if (n1->in(i) > n2->in(i)) return 1;
4675   }
4676 
4677   return 0;
4678 }
4679 
4680 int Compile::cmp_expensive_nodes(Node** n1p, Node** n2p) {
4681   Node* n1 = *n1p;
4682   Node* n2 = *n2p;
4683 
4684   return cmp_expensive_nodes(n1, n2);
4685 }
4686 
4687 void Compile::sort_expensive_nodes() {
4688   if (!expensive_nodes_sorted()) {
4689     _expensive_nodes.sort(cmp_expensive_nodes);
4690   }
4691 }
4692 
4693 bool Compile::expensive_nodes_sorted() const {
4694   for (int i = 1; i < _expensive_nodes.length(); i++) {
4695     if (cmp_expensive_nodes(_expensive_nodes.adr_at(i), _expensive_nodes.adr_at(i-1)) < 0) {
4696       return false;
4697     }
4698   }
4699   return true;
4700 }
4701 
4702 bool Compile::should_optimize_expensive_nodes(PhaseIterGVN &igvn) {
4703   if (_expensive_nodes.length() == 0) {
4704     return false;
4705   }
4706 
4707   assert(OptimizeExpensiveOps, "optimization off?");
4708 
4709   // Take this opportunity to remove dead nodes from the list
4710   int j = 0;
4711   for (int i = 0; i < _expensive_nodes.length(); i++) {
4712     Node* n = _expensive_nodes.at(i);
4713     if (!n->is_unreachable(igvn)) {
4714       assert(n->is_expensive(), "should be expensive");
4715       _expensive_nodes.at_put(j, n);
4716       j++;
4717     }
4718   }
4719   _expensive_nodes.trunc_to(j);
4720 
4721   // Then sort the list so that similar nodes are next to each other
4722   // and check for at least two nodes of identical kind with same data
4723   // inputs.
4724   sort_expensive_nodes();
4725 
4726   for (int i = 0; i < _expensive_nodes.length()-1; i++) {
4727     if (cmp_expensive_nodes(_expensive_nodes.adr_at(i), _expensive_nodes.adr_at(i+1)) == 0) {
4728       return true;
4729     }
4730   }
4731 
4732   return false;
4733 }
4734 
4735 void Compile::cleanup_expensive_nodes(PhaseIterGVN &igvn) {
4736   if (_expensive_nodes.length() == 0) {
4737     return;
4738   }
4739 
4740   assert(OptimizeExpensiveOps, "optimization off?");
4741 
4742   // Sort to bring similar nodes next to each other and clear the
4743   // control input of nodes for which there's only a single copy.
4744   sort_expensive_nodes();
4745 
4746   int j = 0;
4747   int identical = 0;
4748   int i = 0;
4749   bool modified = false;
4750   for (; i < _expensive_nodes.length()-1; i++) {
4751     assert(j <= i, "can't write beyond current index");
4752     if (_expensive_nodes.at(i)->Opcode() == _expensive_nodes.at(i+1)->Opcode()) {
4753       identical++;
4754       _expensive_nodes.at_put(j++, _expensive_nodes.at(i));
4755       continue;
4756     }
4757     if (identical > 0) {
4758       _expensive_nodes.at_put(j++, _expensive_nodes.at(i));
4759       identical = 0;
4760     } else {
4761       Node* n = _expensive_nodes.at(i);
4762       igvn.replace_input_of(n, 0, nullptr);
4763       igvn.hash_insert(n);
4764       modified = true;
4765     }
4766   }
4767   if (identical > 0) {
4768     _expensive_nodes.at_put(j++, _expensive_nodes.at(i));
4769   } else if (_expensive_nodes.length() >= 1) {
4770     Node* n = _expensive_nodes.at(i);
4771     igvn.replace_input_of(n, 0, nullptr);
4772     igvn.hash_insert(n);
4773     modified = true;
4774   }
4775   _expensive_nodes.trunc_to(j);
4776   if (modified) {
4777     igvn.optimize();
4778   }
4779 }
4780 
4781 void Compile::add_expensive_node(Node * n) {
4782   assert(!_expensive_nodes.contains(n), "duplicate entry in expensive list");
4783   assert(n->is_expensive(), "expensive nodes with non-null control here only");
4784   assert(!n->is_CFG() && !n->is_Mem(), "no cfg or memory nodes here");
4785   if (OptimizeExpensiveOps) {
4786     _expensive_nodes.append(n);
4787   } else {
4788     // Clear control input and let IGVN optimize expensive nodes if
4789     // OptimizeExpensiveOps is off.
4790     n->set_req(0, nullptr);
4791   }
4792 }
4793 
4794 /**
4795  * Track coarsened Lock and Unlock nodes.
4796  */
4797 
4798 class Lock_List : public Node_List {
4799   uint _origin_cnt;
4800 public:
4801   Lock_List(Arena *a, uint cnt) : Node_List(a), _origin_cnt(cnt) {}
4802   uint origin_cnt() const { return _origin_cnt; }
4803 };
4804 
4805 void Compile::add_coarsened_locks(GrowableArray<AbstractLockNode*>& locks) {
4806   int length = locks.length();
4807   if (length > 0) {
4808     // Have to keep this list until locks elimination during Macro nodes elimination.
4809     Lock_List* locks_list = new (comp_arena()) Lock_List(comp_arena(), length);
4810     AbstractLockNode* alock = locks.at(0);
4811     BoxLockNode* box = alock->box_node()->as_BoxLock();
4812     for (int i = 0; i < length; i++) {
4813       AbstractLockNode* lock = locks.at(i);
4814       assert(lock->is_coarsened(), "expecting only coarsened AbstractLock nodes, but got '%s'[%d] node", lock->Name(), lock->_idx);
4815       locks_list->push(lock);
4816       BoxLockNode* this_box = lock->box_node()->as_BoxLock();
4817       if (this_box != box) {
4818         // Locking regions (BoxLock) could be Unbalanced here:
4819         //  - its coarsened locks were eliminated in earlier
4820         //    macro nodes elimination followed by loop unroll
4821         //  - it is OSR locking region (no Lock node)
4822         // Preserve Unbalanced status in such cases.
4823         if (!this_box->is_unbalanced()) {
4824           this_box->set_coarsened();
4825         }
4826         if (!box->is_unbalanced()) {
4827           box->set_coarsened();
4828         }
4829       }
4830     }
4831     _coarsened_locks.append(locks_list);
4832   }
4833 }
4834 
4835 void Compile::remove_useless_coarsened_locks(Unique_Node_List& useful) {
4836   int count = coarsened_count();
4837   for (int i = 0; i < count; i++) {
4838     Node_List* locks_list = _coarsened_locks.at(i);
4839     for (uint j = 0; j < locks_list->size(); j++) {
4840       Node* lock = locks_list->at(j);
4841       assert(lock->is_AbstractLock(), "sanity");
4842       if (!useful.member(lock)) {
4843         locks_list->yank(lock);
4844       }
4845     }
4846   }
4847 }
4848 
4849 void Compile::remove_coarsened_lock(Node* n) {
4850   if (n->is_AbstractLock()) {
4851     int count = coarsened_count();
4852     for (int i = 0; i < count; i++) {
4853       Node_List* locks_list = _coarsened_locks.at(i);
4854       locks_list->yank(n);
4855     }
4856   }
4857 }
4858 
4859 bool Compile::coarsened_locks_consistent() {
4860   int count = coarsened_count();
4861   for (int i = 0; i < count; i++) {
4862     bool unbalanced = false;
4863     bool modified = false; // track locks kind modifications
4864     Lock_List* locks_list = (Lock_List*)_coarsened_locks.at(i);
4865     uint size = locks_list->size();
4866     if (size == 0) {
4867       unbalanced = false; // All locks were eliminated - good
4868     } else if (size != locks_list->origin_cnt()) {
4869       unbalanced = true; // Some locks were removed from list
4870     } else {
4871       for (uint j = 0; j < size; j++) {
4872         Node* lock = locks_list->at(j);
4873         // All nodes in group should have the same state (modified or not)
4874         if (!lock->as_AbstractLock()->is_coarsened()) {
4875           if (j == 0) {
4876             // first on list was modified, the rest should be too for consistency
4877             modified = true;
4878           } else if (!modified) {
4879             // this lock was modified but previous locks on the list were not
4880             unbalanced = true;
4881             break;
4882           }
4883         } else if (modified) {
4884           // previous locks on list were modified but not this lock
4885           unbalanced = true;
4886           break;
4887         }
4888       }
4889     }
4890     if (unbalanced) {
4891       // unbalanced monitor enter/exit - only some [un]lock nodes were removed or modified
4892 #ifdef ASSERT
4893       if (PrintEliminateLocks) {
4894         tty->print_cr("=== unbalanced coarsened locks ===");
4895         for (uint l = 0; l < size; l++) {
4896           locks_list->at(l)->dump();
4897         }
4898       }
4899 #endif
4900       record_failure(C2Compiler::retry_no_locks_coarsening());
4901       return false;
4902     }
4903   }
4904   return true;
4905 }
4906 
4907 // Mark locking regions (identified by BoxLockNode) as unbalanced if
4908 // locks coarsening optimization removed Lock/Unlock nodes from them.
4909 // Such regions become unbalanced because coarsening only removes part
4910 // of Lock/Unlock nodes in region. As result we can't execute other
4911 // locks elimination optimizations which assume all code paths have
4912 // corresponding pair of Lock/Unlock nodes - they are balanced.
4913 void Compile::mark_unbalanced_boxes() const {
4914   int count = coarsened_count();
4915   for (int i = 0; i < count; i++) {
4916     Node_List* locks_list = _coarsened_locks.at(i);
4917     uint size = locks_list->size();
4918     if (size > 0) {
4919       AbstractLockNode* alock = locks_list->at(0)->as_AbstractLock();
4920       BoxLockNode* box = alock->box_node()->as_BoxLock();
4921       if (alock->is_coarsened()) {
4922         // coarsened_locks_consistent(), which is called before this method, verifies
4923         // that the rest of Lock/Unlock nodes on locks_list are also coarsened.
4924         assert(!box->is_eliminated(), "regions with coarsened locks should not be marked as eliminated");
4925         for (uint j = 1; j < size; j++) {
4926           assert(locks_list->at(j)->as_AbstractLock()->is_coarsened(), "only coarsened locks are expected here");
4927           BoxLockNode* this_box = locks_list->at(j)->as_AbstractLock()->box_node()->as_BoxLock();
4928           if (box != this_box) {
4929             assert(!this_box->is_eliminated(), "regions with coarsened locks should not be marked as eliminated");
4930             box->set_unbalanced();
4931             this_box->set_unbalanced();
4932           }
4933         }
4934       }
4935     }
4936   }
4937 }
4938 
4939 /**
4940  * Remove the speculative part of types and clean up the graph
4941  */
4942 void Compile::remove_speculative_types(PhaseIterGVN &igvn) {
4943   if (UseTypeSpeculation) {
4944     Unique_Node_List worklist;
4945     worklist.push(root());
4946     int modified = 0;
4947     // Go over all type nodes that carry a speculative type, drop the
4948     // speculative part of the type and enqueue the node for an igvn
4949     // which may optimize it out.
4950     for (uint next = 0; next < worklist.size(); ++next) {
4951       Node *n  = worklist.at(next);
4952       if (n->is_Type()) {
4953         TypeNode* tn = n->as_Type();
4954         const Type* t = tn->type();
4955         const Type* t_no_spec = t->remove_speculative();
4956         if (t_no_spec != t) {
4957           bool in_hash = igvn.hash_delete(n);
4958           assert(in_hash || n->hash() == Node::NO_HASH, "node should be in igvn hash table");
4959           tn->set_type(t_no_spec);
4960           igvn.hash_insert(n);
4961           igvn._worklist.push(n); // give it a chance to go away
4962           modified++;
4963         }
4964       }
4965       // Iterate over outs - endless loops is unreachable from below
4966       for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
4967         Node *m = n->fast_out(i);
4968         if (not_a_node(m)) {
4969           continue;
4970         }
4971         worklist.push(m);
4972       }
4973     }
4974     // Drop the speculative part of all types in the igvn's type table
4975     igvn.remove_speculative_types();
4976     if (modified > 0) {
4977       igvn.optimize();
4978       if (failing())  return;
4979     }
4980 #ifdef ASSERT
4981     // Verify that after the IGVN is over no speculative type has resurfaced
4982     worklist.clear();
4983     worklist.push(root());
4984     for (uint next = 0; next < worklist.size(); ++next) {
4985       Node *n  = worklist.at(next);
4986       const Type* t = igvn.type_or_null(n);
4987       assert((t == nullptr) || (t == t->remove_speculative()), "no more speculative types");
4988       if (n->is_Type()) {
4989         t = n->as_Type()->type();
4990         assert(t == t->remove_speculative(), "no more speculative types");
4991       }
4992       // Iterate over outs - endless loops is unreachable from below
4993       for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
4994         Node *m = n->fast_out(i);
4995         if (not_a_node(m)) {
4996           continue;
4997         }
4998         worklist.push(m);
4999       }
5000     }
5001     igvn.check_no_speculative_types();
5002 #endif
5003   }
5004 }
5005 
5006 // Auxiliary methods to support randomized stressing/fuzzing.
5007 
5008 void Compile::initialize_stress_seed(const DirectiveSet* directive) {
5009   if (FLAG_IS_DEFAULT(StressSeed) || (FLAG_IS_ERGO(StressSeed) && directive->RepeatCompilationOption)) {
5010     _stress_seed = static_cast<uint>(Ticks::now().nanoseconds());
5011     FLAG_SET_ERGO(StressSeed, _stress_seed);
5012   } else {
5013     _stress_seed = StressSeed;
5014   }
5015   if (_log != nullptr) {
5016     _log->elem("stress_test seed='%u'", _stress_seed);
5017   }
5018 }
5019 
5020 int Compile::random() {
5021   _stress_seed = os::next_random(_stress_seed);
5022   return static_cast<int>(_stress_seed);
5023 }
5024 
5025 // This method can be called the arbitrary number of times, with current count
5026 // as the argument. The logic allows selecting a single candidate from the
5027 // running list of candidates as follows:
5028 //    int count = 0;
5029 //    Cand* selected = null;
5030 //    while(cand = cand->next()) {
5031 //      if (randomized_select(++count)) {
5032 //        selected = cand;
5033 //      }
5034 //    }
5035 //
5036 // Including count equalizes the chances any candidate is "selected".
5037 // This is useful when we don't have the complete list of candidates to choose
5038 // from uniformly. In this case, we need to adjust the randomicity of the
5039 // selection, or else we will end up biasing the selection towards the latter
5040 // candidates.
5041 //
5042 // Quick back-envelope calculation shows that for the list of n candidates
5043 // the equal probability for the candidate to persist as "best" can be
5044 // achieved by replacing it with "next" k-th candidate with the probability
5045 // of 1/k. It can be easily shown that by the end of the run, the
5046 // probability for any candidate is converged to 1/n, thus giving the
5047 // uniform distribution among all the candidates.
5048 //
5049 // We don't care about the domain size as long as (RANDOMIZED_DOMAIN / count) is large.
5050 #define RANDOMIZED_DOMAIN_POW 29
5051 #define RANDOMIZED_DOMAIN (1 << RANDOMIZED_DOMAIN_POW)
5052 #define RANDOMIZED_DOMAIN_MASK ((1 << (RANDOMIZED_DOMAIN_POW + 1)) - 1)
5053 bool Compile::randomized_select(int count) {
5054   assert(count > 0, "only positive");
5055   return (random() & RANDOMIZED_DOMAIN_MASK) < (RANDOMIZED_DOMAIN / count);
5056 }
5057 
5058 #ifdef ASSERT
5059 // Failures are geometrically distributed with probability 1/StressBailoutMean.
5060 bool Compile::fail_randomly() {
5061   if ((random() % StressBailoutMean) != 0) {
5062     return false;
5063   }
5064   record_failure("StressBailout");
5065   return true;
5066 }
5067 
5068 bool Compile::failure_is_artificial() {
5069   return C->failure_reason_is("StressBailout");
5070 }
5071 #endif
5072 
5073 CloneMap&     Compile::clone_map()                 { return _clone_map; }
5074 void          Compile::set_clone_map(Dict* d)      { _clone_map._dict = d; }
5075 
5076 void NodeCloneInfo::dump_on(outputStream* st) const {
5077   st->print(" {%d:%d} ", idx(), gen());
5078 }
5079 
5080 void CloneMap::clone(Node* old, Node* nnn, int gen) {
5081   uint64_t val = value(old->_idx);
5082   NodeCloneInfo cio(val);
5083   assert(val != 0, "old node should be in the map");
5084   NodeCloneInfo cin(cio.idx(), gen + cio.gen());
5085   insert(nnn->_idx, cin.get());
5086 #ifndef PRODUCT
5087   if (is_debug()) {
5088     tty->print_cr("CloneMap::clone inserted node %d info {%d:%d} into CloneMap", nnn->_idx, cin.idx(), cin.gen());
5089   }
5090 #endif
5091 }
5092 
5093 void CloneMap::verify_insert_and_clone(Node* old, Node* nnn, int gen) {
5094   NodeCloneInfo cio(value(old->_idx));
5095   if (cio.get() == 0) {
5096     cio.set(old->_idx, 0);
5097     insert(old->_idx, cio.get());
5098 #ifndef PRODUCT
5099     if (is_debug()) {
5100       tty->print_cr("CloneMap::verify_insert_and_clone inserted node %d info {%d:%d} into CloneMap", old->_idx, cio.idx(), cio.gen());
5101     }
5102 #endif
5103   }
5104   clone(old, nnn, gen);
5105 }
5106 
5107 int CloneMap::max_gen() const {
5108   int g = 0;
5109   DictI di(_dict);
5110   for(; di.test(); ++di) {
5111     int t = gen(di._key);
5112     if (g < t) {
5113       g = t;
5114 #ifndef PRODUCT
5115       if (is_debug()) {
5116         tty->print_cr("CloneMap::max_gen() update max=%d from %d", g, _2_node_idx_t(di._key));
5117       }
5118 #endif
5119     }
5120   }
5121   return g;
5122 }
5123 
5124 void CloneMap::dump(node_idx_t key, outputStream* st) const {
5125   uint64_t val = value(key);
5126   if (val != 0) {
5127     NodeCloneInfo ni(val);
5128     ni.dump_on(st);
5129   }
5130 }
5131 
5132 void Compile::shuffle_macro_nodes() {
5133   if (_macro_nodes.length() < 2) {
5134     return;
5135   }
5136   for (uint i = _macro_nodes.length() - 1; i >= 1; i--) {
5137     uint j = C->random() % (i + 1);
5138     swap(_macro_nodes.at(i), _macro_nodes.at(j));
5139   }
5140 }
5141 
5142 // Move Allocate nodes to the start of the list
5143 void Compile::sort_macro_nodes() {
5144   int count = macro_count();
5145   int allocates = 0;
5146   for (int i = 0; i < count; i++) {
5147     Node* n = macro_node(i);
5148     if (n->is_Allocate()) {
5149       if (i != allocates) {
5150         Node* tmp = macro_node(allocates);
5151         _macro_nodes.at_put(allocates, n);
5152         _macro_nodes.at_put(i, tmp);
5153       }
5154       allocates++;
5155     }
5156   }
5157 }
5158 
5159 void Compile::print_method(CompilerPhaseType cpt, int level, Node* n) {
5160   if (failing_internal()) { return; } // failing_internal to not stress bailouts from printing code.
5161   EventCompilerPhase event(UNTIMED);
5162   if (event.should_commit()) {
5163     CompilerEvent::PhaseEvent::post(event, C->_latest_stage_start_counter, cpt, C->_compile_id, level);
5164   }
5165 #ifndef PRODUCT
5166   ResourceMark rm;
5167   stringStream ss;
5168   ss.print_raw(CompilerPhaseTypeHelper::to_description(cpt));
5169   int iter = ++_igv_phase_iter[cpt];
5170   if (iter > 1) {
5171     ss.print(" %d", iter);
5172   }
5173   if (n != nullptr) {
5174     ss.print(": %d %s", n->_idx, NodeClassNames[n->Opcode()]);
5175     if (n->is_Call()) {
5176       CallNode* call = n->as_Call();
5177       if (call->_name != nullptr) {
5178         // E.g. uncommon traps etc.
5179         ss.print(" - %s", call->_name);
5180       } else if (call->is_CallJava()) {
5181         CallJavaNode* call_java = call->as_CallJava();
5182         if (call_java->method() != nullptr) {
5183           ss.print(" -");
5184           call_java->method()->print_short_name(&ss);
5185         }
5186       }
5187     }
5188   }
5189 
5190   const char* name = ss.as_string();
5191   if (should_print_igv(level)) {
5192     _igv_printer->print_graph(name);
5193   }
5194   if (should_print_phase(level)) {
5195     print_phase(name);
5196   }
5197   if (should_print_ideal_phase(cpt)) {
5198     print_ideal_ir(CompilerPhaseTypeHelper::to_name(cpt));
5199   }
5200 #endif
5201   C->_latest_stage_start_counter.stamp();
5202 }
5203 
5204 // Only used from CompileWrapper
5205 void Compile::begin_method() {
5206 #ifndef PRODUCT
5207   if (_method != nullptr && should_print_igv(1)) {
5208     _igv_printer->begin_method();
5209   }
5210 #endif
5211   C->_latest_stage_start_counter.stamp();
5212 }
5213 
5214 // Only used from CompileWrapper
5215 void Compile::end_method() {
5216   EventCompilerPhase event(UNTIMED);
5217   if (event.should_commit()) {
5218     CompilerEvent::PhaseEvent::post(event, C->_latest_stage_start_counter, PHASE_END, C->_compile_id, 1);
5219   }
5220 
5221 #ifndef PRODUCT
5222   if (_method != nullptr && should_print_igv(1)) {
5223     _igv_printer->end_method();
5224   }
5225 #endif
5226 }
5227 
5228 #ifndef PRODUCT
5229 bool Compile::should_print_phase(const int level) const {
5230   return PrintPhaseLevel >= 0 && directive()->PhasePrintLevelOption >= level &&
5231          _method != nullptr; // Do not print phases for stubs.
5232 }
5233 
5234 bool Compile::should_print_ideal_phase(CompilerPhaseType cpt) const {
5235   return _directive->should_print_ideal_phase(cpt);
5236 }
5237 
5238 void Compile::init_igv() {
5239   if (_igv_printer == nullptr) {
5240     _igv_printer = IdealGraphPrinter::printer();
5241     _igv_printer->set_compile(this);
5242   }
5243 }
5244 
5245 bool Compile::should_print_igv(const int level) {
5246   PRODUCT_RETURN_(return false;);
5247 
5248   if (PrintIdealGraphLevel < 0) { // disabled by the user
5249     return false;
5250   }
5251 
5252   bool need = directive()->IGVPrintLevelOption >= level;
5253   if (need) {
5254     Compile::init_igv();
5255   }
5256   return need;
5257 }
5258 
5259 IdealGraphPrinter* Compile::_debug_file_printer = nullptr;
5260 IdealGraphPrinter* Compile::_debug_network_printer = nullptr;
5261 
5262 // Called from debugger. Prints method to the default file with the default phase name.
5263 // This works regardless of any Ideal Graph Visualizer flags set or not.
5264 // Use in debugger (gdb/rr): p igv_print($sp, $fp, $pc).
5265 void igv_print(void* sp, void* fp, void* pc) {
5266   frame fr(sp, fp, pc);
5267   Compile::current()->igv_print_method_to_file(nullptr, false, &fr);
5268 }
5269 
5270 // Same as igv_print() above but with a specified phase name.
5271 void igv_print(const char* phase_name, void* sp, void* fp, void* pc) {
5272   frame fr(sp, fp, pc);
5273   Compile::current()->igv_print_method_to_file(phase_name, false, &fr);
5274 }
5275 
5276 // Called from debugger. Prints method with the default phase name to the default network or the one specified with
5277 // the network flags for the Ideal Graph Visualizer, or to the default file depending on the 'network' argument.
5278 // This works regardless of any Ideal Graph Visualizer flags set or not.
5279 // Use in debugger (gdb/rr): p igv_print(true, $sp, $fp, $pc).
5280 void igv_print(bool network, void* sp, void* fp, void* pc) {
5281   frame fr(sp, fp, pc);
5282   if (network) {
5283     Compile::current()->igv_print_method_to_network(nullptr, &fr);
5284   } else {
5285     Compile::current()->igv_print_method_to_file(nullptr, false, &fr);
5286   }
5287 }
5288 
5289 // Same as igv_print(bool network, ...) above but with a specified phase name.
5290 // Use in debugger (gdb/rr): p igv_print(true, "MyPhase", $sp, $fp, $pc).
5291 void igv_print(bool network, const char* phase_name, void* sp, void* fp, void* pc) {
5292   frame fr(sp, fp, pc);
5293   if (network) {
5294     Compile::current()->igv_print_method_to_network(phase_name, &fr);
5295   } else {
5296     Compile::current()->igv_print_method_to_file(phase_name, false, &fr);
5297   }
5298 }
5299 
5300 // Called from debugger. Normal write to the default _printer. Only works if Ideal Graph Visualizer printing flags are set.
5301 void igv_print_default() {
5302   Compile::current()->print_method(PHASE_DEBUG, 0);
5303 }
5304 
5305 // Called from debugger, especially when replaying a trace in which the program state cannot be altered like with rr replay.
5306 // A method is appended to an existing default file with the default phase name. This means that igv_append() must follow
5307 // an earlier igv_print(*) call which sets up the file. This works regardless of any Ideal Graph Visualizer flags set or not.
5308 // Use in debugger (gdb/rr): p igv_append($sp, $fp, $pc).
5309 void igv_append(void* sp, void* fp, void* pc) {
5310   frame fr(sp, fp, pc);
5311   Compile::current()->igv_print_method_to_file(nullptr, true, &fr);
5312 }
5313 
5314 // Same as igv_append(...) above but with a specified phase name.
5315 // Use in debugger (gdb/rr): p igv_append("MyPhase", $sp, $fp, $pc).
5316 void igv_append(const char* phase_name, void* sp, void* fp, void* pc) {
5317   frame fr(sp, fp, pc);
5318   Compile::current()->igv_print_method_to_file(phase_name, true, &fr);
5319 }
5320 
5321 void Compile::igv_print_method_to_file(const char* phase_name, bool append, const frame* fr) {
5322   const char* file_name = "custom_debug.xml";
5323   if (_debug_file_printer == nullptr) {
5324     _debug_file_printer = new IdealGraphPrinter(C, file_name, append);
5325   } else {
5326     _debug_file_printer->update_compiled_method(C->method());
5327   }
5328   tty->print_cr("Method %s to %s", append ? "appended" : "printed", file_name);
5329   _debug_file_printer->print_graph(phase_name, fr);
5330 }
5331 
5332 void Compile::igv_print_method_to_network(const char* phase_name, const frame* fr) {
5333   ResourceMark rm;
5334   GrowableArray<const Node*> empty_list;
5335   igv_print_graph_to_network(phase_name, empty_list, fr);
5336 }
5337 
5338 void Compile::igv_print_graph_to_network(const char* name, GrowableArray<const Node*>& visible_nodes, const frame* fr) {
5339   if (_debug_network_printer == nullptr) {
5340     _debug_network_printer = new IdealGraphPrinter(C);
5341   } else {
5342     _debug_network_printer->update_compiled_method(C->method());
5343   }
5344   tty->print_cr("Method printed over network stream to IGV");
5345   _debug_network_printer->print(name, C->root(), visible_nodes, fr);
5346 }
5347 #endif // !PRODUCT
5348 
5349 Node* Compile::narrow_value(BasicType bt, Node* value, const Type* type, PhaseGVN* phase, bool transform_res) {
5350   if (type != nullptr && phase->type(value)->higher_equal(type)) {
5351     return value;
5352   }
5353   Node* result = nullptr;
5354   if (bt == T_BYTE) {
5355     result = phase->transform(new LShiftINode(value, phase->intcon(24)));
5356     result = new RShiftINode(result, phase->intcon(24));
5357   } else if (bt == T_BOOLEAN) {
5358     result = new AndINode(value, phase->intcon(0xFF));
5359   } else if (bt == T_CHAR) {
5360     result = new AndINode(value,phase->intcon(0xFFFF));
5361   } else {
5362     assert(bt == T_SHORT, "unexpected narrow type");
5363     result = phase->transform(new LShiftINode(value, phase->intcon(16)));
5364     result = new RShiftINode(result, phase->intcon(16));
5365   }
5366   if (transform_res) {
5367     result = phase->transform(result);
5368   }
5369   return result;
5370 }
5371 
5372 void Compile::record_method_not_compilable_oom() {
5373   record_method_not_compilable(CompilationMemoryStatistic::failure_reason_memlimit());
5374 }
5375 
5376 #ifndef PRODUCT
5377 // Collects all the control inputs from nodes on the worklist and from their data dependencies
5378 static void find_candidate_control_inputs(Unique_Node_List& worklist, Unique_Node_List& candidates) {
5379   // Follow non-control edges until we reach CFG nodes
5380   for (uint i = 0; i < worklist.size(); i++) {
5381     const Node* n = worklist.at(i);
5382     for (uint j = 0; j < n->req(); j++) {
5383       Node* in = n->in(j);
5384       if (in == nullptr || in->is_Root()) {
5385         continue;
5386       }
5387       if (in->is_CFG()) {
5388         if (in->is_Call()) {
5389           // The return value of a call is only available if the call did not result in an exception
5390           Node* control_proj_use = in->as_Call()->proj_out(TypeFunc::Control)->unique_out();
5391           if (control_proj_use->is_Catch()) {
5392             Node* fall_through = control_proj_use->as_Catch()->proj_out(CatchProjNode::fall_through_index);
5393             candidates.push(fall_through);
5394             continue;
5395           }
5396         }
5397 
5398         if (in->is_Multi()) {
5399           // We got here by following data inputs so we should only have one control use
5400           // (no IfNode, etc)
5401           assert(!n->is_MultiBranch(), "unexpected node type: %s", n->Name());
5402           candidates.push(in->as_Multi()->proj_out(TypeFunc::Control));
5403         } else {
5404           candidates.push(in);
5405         }
5406       } else {
5407         worklist.push(in);
5408       }
5409     }
5410   }
5411 }
5412 
5413 // Returns the candidate node that is a descendant to all the other candidates
5414 static Node* pick_control(Unique_Node_List& candidates) {
5415   Unique_Node_List worklist;
5416   worklist.copy(candidates);
5417 
5418   // Traverse backwards through the CFG
5419   for (uint i = 0; i < worklist.size(); i++) {
5420     const Node* n = worklist.at(i);
5421     if (n->is_Root()) {
5422       continue;
5423     }
5424     for (uint j = 0; j < n->req(); j++) {
5425       // Skip backedge of loops to avoid cycles
5426       if (n->is_Loop() && j == LoopNode::LoopBackControl) {
5427         continue;
5428       }
5429 
5430       Node* pred = n->in(j);
5431       if (pred != nullptr && pred != n && pred->is_CFG()) {
5432         worklist.push(pred);
5433         // if pred is an ancestor of n, then pred is an ancestor to at least one candidate
5434         candidates.remove(pred);
5435       }
5436     }
5437   }
5438 
5439   assert(candidates.size() == 1, "unexpected control flow");
5440   return candidates.at(0);
5441 }
5442 
5443 // Initialize a parameter input for a debug print call, using a placeholder for jlong and jdouble
5444 static void debug_print_init_parm(Node* call, Node* parm, Node* half, int* pos) {
5445   call->init_req((*pos)++, parm);
5446   const BasicType bt = parm->bottom_type()->basic_type();
5447   if (bt == T_LONG || bt == T_DOUBLE) {
5448     call->init_req((*pos)++, half);
5449   }
5450 }
5451 
5452 Node* Compile::make_debug_print_call(const char* str, address call_addr, PhaseGVN* gvn,
5453                               Node* parm0, Node* parm1,
5454                               Node* parm2, Node* parm3,
5455                               Node* parm4, Node* parm5,
5456                               Node* parm6) const {
5457   Node* str_node = gvn->transform(new ConPNode(TypeRawPtr::make(((address) str))));
5458   const TypeFunc* type = OptoRuntime::debug_print_Type(parm0, parm1, parm2, parm3, parm4, parm5, parm6);
5459   Node* call = new CallLeafNode(type, call_addr, "debug_print", TypeRawPtr::BOTTOM);
5460 
5461   // find the most suitable control input
5462   Unique_Node_List worklist, candidates;
5463   if (parm0 != nullptr) { worklist.push(parm0);
5464   if (parm1 != nullptr) { worklist.push(parm1);
5465   if (parm2 != nullptr) { worklist.push(parm2);
5466   if (parm3 != nullptr) { worklist.push(parm3);
5467   if (parm4 != nullptr) { worklist.push(parm4);
5468   if (parm5 != nullptr) { worklist.push(parm5);
5469   if (parm6 != nullptr) { worklist.push(parm6);
5470   /* close each nested if ===> */  } } } } } } }
5471   find_candidate_control_inputs(worklist, candidates);
5472   Node* control = nullptr;
5473   if (candidates.size() == 0) {
5474     control = C->start()->proj_out(TypeFunc::Control);
5475   } else {
5476     control = pick_control(candidates);
5477   }
5478 
5479   // find all the previous users of the control we picked
5480   GrowableArray<Node*> users_of_control;
5481   for (DUIterator_Fast kmax, i = control->fast_outs(kmax); i < kmax; i++) {
5482     Node* use = control->fast_out(i);
5483     if (use->is_CFG() && use != control) {
5484       users_of_control.push(use);
5485     }
5486   }
5487 
5488   // we do not actually care about IO and memory as it uses neither
5489   call->init_req(TypeFunc::Control,   control);
5490   call->init_req(TypeFunc::I_O,       top());
5491   call->init_req(TypeFunc::Memory,    top());
5492   call->init_req(TypeFunc::FramePtr,  C->start()->proj_out(TypeFunc::FramePtr));
5493   call->init_req(TypeFunc::ReturnAdr, top());
5494 
5495   int pos = TypeFunc::Parms;
5496   call->init_req(pos++, str_node);
5497   if (parm0 != nullptr) { debug_print_init_parm(call, parm0, top(), &pos);
5498   if (parm1 != nullptr) { debug_print_init_parm(call, parm1, top(), &pos);
5499   if (parm2 != nullptr) { debug_print_init_parm(call, parm2, top(), &pos);
5500   if (parm3 != nullptr) { debug_print_init_parm(call, parm3, top(), &pos);
5501   if (parm4 != nullptr) { debug_print_init_parm(call, parm4, top(), &pos);
5502   if (parm5 != nullptr) { debug_print_init_parm(call, parm5, top(), &pos);
5503   if (parm6 != nullptr) { debug_print_init_parm(call, parm6, top(), &pos);
5504   /* close each nested if ===> */  } } } } } } }
5505   assert(call->in(call->req()-1) != nullptr, "must initialize all parms");
5506 
5507   call = gvn->transform(call);
5508   Node* call_control_proj = gvn->transform(new ProjNode(call, TypeFunc::Control));
5509 
5510   // rewire previous users to have the new call as control instead
5511   PhaseIterGVN* igvn = gvn->is_IterGVN();
5512   for (int i = 0; i < users_of_control.length(); i++) {
5513     Node* use = users_of_control.at(i);
5514     for (uint j = 0; j < use->req(); j++) {
5515       if (use->in(j) == control) {
5516         if (igvn != nullptr) {
5517           igvn->replace_input_of(use, j, call_control_proj);
5518         } else {
5519           gvn->hash_delete(use);
5520           use->set_req(j, call_control_proj);
5521           gvn->hash_insert(use);
5522         }
5523       }
5524     }
5525   }
5526 
5527   return call;
5528 }
5529 #endif // !PRODUCT