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     // It is important that we traverse both inputs and outputs of nodes,
 595     // so that we reach all nodes that are connected to Root.
 596     root()->dump_bfs(MaxNodeLimit, nullptr, "-+S$", &ss);
 597   } else {
 598     // Dump the node blockwise if we have a scheduling
 599     _output->print_scheduling(&ss);
 600   }
 601 
 602   // Check that the lock is not broken by a safepoint.
 603   NoSafepointVerifier nsv;
 604   ttyLocker ttyl;
 605   if (xtty != nullptr) {
 606     xtty->head("ideal compile_id='%d'%s compile_phase='%s'",
 607                compile_id(),
 608                is_osr_compilation() ? " compile_kind='osr'" : "",
 609                phase_name);
 610   }
 611 
 612   tty->print("%s", ss.as_string());
 613 
 614   if (xtty != nullptr) {
 615     xtty->tail("ideal");
 616   }
 617 }
 618 #endif
 619 
 620 // ============================================================================
 621 //------------------------------Compile standard-------------------------------
 622 
 623 // Compile a method.  entry_bci is -1 for normal compilations and indicates
 624 // the continuation bci for on stack replacement.
 625 
 626 
 627 Compile::Compile(ciEnv* ci_env, ciMethod* target, int osr_bci,
 628                  Options options, DirectiveSet* directive)
 629     : Phase(Compiler),
 630       _compile_id(ci_env->compile_id()),
 631       _options(options),
 632       _method(target),
 633       _entry_bci(osr_bci),
 634       _ilt(nullptr),
 635       _stub_function(nullptr),
 636       _stub_name(nullptr),
 637       _stub_id(StubId::NO_STUBID),
 638       _stub_entry_point(nullptr),
 639       _max_node_limit(MaxNodeLimit),
 640       _post_loop_opts_phase(false),
 641       _merge_stores_phase(false),
 642       _allow_macro_nodes(true),
 643       _inlining_progress(false),
 644       _inlining_incrementally(false),
 645       _do_cleanup(false),
 646       _has_reserved_stack_access(target->has_reserved_stack_access()),
 647 #ifndef PRODUCT
 648       _igv_idx(0),
 649       _trace_opto_output(directive->TraceOptoOutputOption),
 650 #endif
 651       _clinit_barrier_on_entry(false),
 652       _stress_seed(0),
 653       _comp_arena(mtCompiler, Arena::Tag::tag_comp),
 654       _barrier_set_state(BarrierSet::barrier_set()->barrier_set_c2()->create_barrier_state(comp_arena())),
 655       _env(ci_env),
 656       _directive(directive),
 657       _log(ci_env->log()),
 658       _first_failure_details(nullptr),
 659       _intrinsics(comp_arena(), 0, 0, nullptr),
 660       _macro_nodes(comp_arena(), 8, 0, nullptr),
 661       _parse_predicates(comp_arena(), 8, 0, nullptr),
 662       _template_assertion_predicate_opaques(comp_arena(), 8, 0, nullptr),
 663       _expensive_nodes(comp_arena(), 8, 0, nullptr),
 664       _for_post_loop_igvn(comp_arena(), 8, 0, nullptr),
 665       _for_merge_stores_igvn(comp_arena(), 8, 0, nullptr),
 666       _unstable_if_traps(comp_arena(), 8, 0, nullptr),
 667       _coarsened_locks(comp_arena(), 8, 0, nullptr),
 668       _congraph(nullptr),
 669       NOT_PRODUCT(_igv_printer(nullptr) COMMA)
 670           _unique(0),
 671       _dead_node_count(0),
 672       _dead_node_list(comp_arena()),
 673       _node_arena_one(mtCompiler, Arena::Tag::tag_node),
 674       _node_arena_two(mtCompiler, Arena::Tag::tag_node),
 675       _node_arena(&_node_arena_one),
 676       _mach_constant_base_node(nullptr),
 677       _Compile_types(mtCompiler, Arena::Tag::tag_type),
 678       _initial_gvn(nullptr),
 679       _igvn_worklist(nullptr),
 680       _types(nullptr),
 681       _node_hash(nullptr),
 682       _late_inlines(comp_arena(), 2, 0, nullptr),
 683       _string_late_inlines(comp_arena(), 2, 0, nullptr),
 684       _boxing_late_inlines(comp_arena(), 2, 0, nullptr),
 685       _vector_reboxing_late_inlines(comp_arena(), 2, 0, nullptr),
 686       _late_inlines_pos(0),
 687       _has_mh_late_inlines(false),
 688       _oom(false),
 689       _replay_inline_data(nullptr),
 690       _inline_printer(this),
 691       _java_calls(0),
 692       _inner_loops(0),
 693       _FIRST_STACK_mask(comp_arena()),
 694       _interpreter_frame_size(0),
 695       _regmask_arena(mtCompiler, Arena::Tag::tag_regmask),
 696       _output(nullptr)
 697 #ifndef PRODUCT
 698       ,
 699       _in_dump_cnt(0)
 700 #endif
 701 {
 702   C = this;
 703   CompileWrapper cw(this);
 704 
 705   TraceTime t1("Total compilation time", &_t_totalCompilation, CITime, CITimeVerbose);
 706   TraceTime t2(nullptr, &_t_methodCompilation, CITime, false);
 707 
 708 #if defined(SUPPORT_ASSEMBLY) || defined(SUPPORT_ABSTRACT_ASSEMBLY)
 709   bool print_opto_assembly = directive->PrintOptoAssemblyOption;
 710   // We can always print a disassembly, either abstract (hex dump) or
 711   // with the help of a suitable hsdis library. Thus, we should not
 712   // couple print_assembly and print_opto_assembly controls.
 713   // But: always print opto and regular assembly on compile command 'print'.
 714   bool print_assembly = directive->PrintAssemblyOption;
 715   set_print_assembly(print_opto_assembly || print_assembly);
 716 #else
 717   set_print_assembly(false); // must initialize.
 718 #endif
 719 
 720 #ifndef PRODUCT
 721   set_parsed_irreducible_loop(false);
 722 #endif
 723 
 724   if (directive->ReplayInlineOption) {
 725     _replay_inline_data = ciReplay::load_inline_data(method(), entry_bci(), ci_env->comp_level());
 726   }
 727   set_print_inlining(directive->PrintInliningOption || PrintOptoInlining);
 728   set_print_intrinsics(directive->PrintIntrinsicsOption);
 729   set_has_irreducible_loop(true); // conservative until build_loop_tree() reset it
 730 
 731   if (ProfileTraps) {
 732     // Make sure the method being compiled gets its own MDO,
 733     // so we can at least track the decompile_count().
 734     method()->ensure_method_data();
 735   }
 736 
 737   if (StressLCM || StressGCM || StressIGVN || StressCCP ||
 738       StressIncrementalInlining || StressMacroExpansion ||
 739       StressMacroElimination || StressUnstableIfTraps ||
 740       StressBailout || StressLoopPeeling) {
 741     initialize_stress_seed(directive);
 742   }
 743 
 744   Init(/*do_aliasing=*/ true);
 745 
 746   print_compile_messages();
 747 
 748   _ilt = InlineTree::build_inline_tree_root();
 749 
 750   // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
 751   assert(num_alias_types() >= AliasIdxRaw, "");
 752 
 753 #define MINIMUM_NODE_HASH  1023
 754 
 755   // GVN that will be run immediately on new nodes
 756   uint estimated_size = method()->code_size()*4+64;
 757   estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
 758   _igvn_worklist = new (comp_arena()) Unique_Node_List(comp_arena());
 759   _types = new (comp_arena()) Type_Array(comp_arena());
 760   _node_hash = new (comp_arena()) NodeHash(comp_arena(), estimated_size);
 761   PhaseGVN gvn;
 762   set_initial_gvn(&gvn);
 763 
 764   { // Scope for timing the parser
 765     TracePhase tp(_t_parser);
 766 
 767     // Put top into the hash table ASAP.
 768     initial_gvn()->transform(top());
 769 
 770     // Set up tf(), start(), and find a CallGenerator.
 771     CallGenerator* cg = nullptr;
 772     if (is_osr_compilation()) {
 773       const TypeTuple *domain = StartOSRNode::osr_domain();
 774       const TypeTuple *range = TypeTuple::make_range(method()->signature());
 775       init_tf(TypeFunc::make(domain, range));
 776       StartNode* s = new StartOSRNode(root(), domain);
 777       initial_gvn()->set_type_bottom(s);
 778       verify_start(s);
 779       cg = CallGenerator::for_osr(method(), entry_bci());
 780     } else {
 781       // Normal case.
 782       init_tf(TypeFunc::make(method()));
 783       StartNode* s = new StartNode(root(), tf()->domain());
 784       initial_gvn()->set_type_bottom(s);
 785       verify_start(s);
 786       float past_uses = method()->interpreter_invocation_count();
 787       float expected_uses = past_uses;
 788       cg = CallGenerator::for_inline(method(), expected_uses);
 789     }
 790     if (failing())  return;
 791     if (cg == nullptr) {
 792       const char* reason = InlineTree::check_can_parse(method());
 793       assert(reason != nullptr, "expect reason for parse failure");
 794       stringStream ss;
 795       ss.print("cannot parse method: %s", reason);
 796       record_method_not_compilable(ss.as_string());
 797       return;
 798     }
 799 
 800     gvn.set_type(root(), root()->bottom_type());
 801 
 802     JVMState* jvms = build_start_state(start(), tf());
 803     if ((jvms = cg->generate(jvms)) == nullptr) {
 804       assert(failure_reason() != nullptr, "expect reason for parse failure");
 805       stringStream ss;
 806       ss.print("method parse failed: %s", failure_reason());
 807       record_method_not_compilable(ss.as_string() DEBUG_ONLY(COMMA true));
 808       return;
 809     }
 810     GraphKit kit(jvms);
 811 
 812     if (!kit.stopped()) {
 813       // Accept return values, and transfer control we know not where.
 814       // This is done by a special, unique ReturnNode bound to root.
 815       return_values(kit.jvms());
 816     }
 817 
 818     if (kit.has_exceptions()) {
 819       // Any exceptions that escape from this call must be rethrown
 820       // to whatever caller is dynamically above us on the stack.
 821       // This is done by a special, unique RethrowNode bound to root.
 822       rethrow_exceptions(kit.transfer_exceptions_into_jvms());
 823     }
 824 
 825     assert(IncrementalInline || (_late_inlines.length() == 0 && !has_mh_late_inlines()), "incremental inlining is off");
 826 
 827     if (_late_inlines.length() == 0 && !has_mh_late_inlines() && !failing() && has_stringbuilder()) {
 828       inline_string_calls(true);
 829     }
 830 
 831     if (failing())  return;
 832 
 833     // Remove clutter produced by parsing.
 834     if (!failing()) {
 835       ResourceMark rm;
 836       PhaseRemoveUseless pru(initial_gvn(), *igvn_worklist());
 837     }
 838   }
 839 
 840   // Note:  Large methods are capped off in do_one_bytecode().
 841   if (failing())  return;
 842 
 843   // After parsing, node notes are no longer automagic.
 844   // They must be propagated by register_new_node_with_optimizer(),
 845   // clone(), or the like.
 846   set_default_node_notes(nullptr);
 847 
 848 #ifndef PRODUCT
 849   if (should_print_igv(1)) {
 850     _igv_printer->print_inlining();
 851   }
 852 #endif
 853 
 854   if (failing())  return;
 855   NOT_PRODUCT( verify_graph_edges(); )
 856 
 857   // Now optimize
 858   Optimize();
 859   if (failing())  return;
 860   NOT_PRODUCT( verify_graph_edges(); )
 861 
 862 #ifndef PRODUCT
 863   if (should_print_ideal()) {
 864     print_ideal_ir("print_ideal");
 865   }
 866 #endif
 867 
 868 #ifdef ASSERT
 869   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 870   bs->verify_gc_barriers(this, BarrierSetC2::BeforeCodeGen);
 871 #endif
 872 
 873   // Dump compilation data to replay it.
 874   if (directive->DumpReplayOption) {
 875     env()->dump_replay_data(_compile_id);
 876   }
 877   if (directive->DumpInlineOption && (ilt() != nullptr)) {
 878     env()->dump_inline_data(_compile_id);
 879   }
 880 
 881   // Now that we know the size of all the monitors we can add a fixed slot
 882   // for the original deopt pc.
 883   int next_slot = fixed_slots() + (sizeof(address) / VMRegImpl::stack_slot_size);
 884   set_fixed_slots(next_slot);
 885 
 886   // Compute when to use implicit null checks. Used by matching trap based
 887   // nodes and NullCheck optimization.
 888   set_allowed_deopt_reasons();
 889 
 890   // Now generate code
 891   Code_Gen();
 892 }
 893 
 894 //------------------------------Compile----------------------------------------
 895 // Compile a runtime stub
 896 Compile::Compile(ciEnv* ci_env,
 897                  TypeFunc_generator generator,
 898                  address stub_function,
 899                  const char* stub_name,
 900                  StubId stub_id,
 901                  int is_fancy_jump,
 902                  bool pass_tls,
 903                  bool return_pc,
 904                  DirectiveSet* directive)
 905     : Phase(Compiler),
 906       _compile_id(0),
 907       _options(Options::for_runtime_stub()),
 908       _method(nullptr),
 909       _entry_bci(InvocationEntryBci),
 910       _stub_function(stub_function),
 911       _stub_name(stub_name),
 912       _stub_id(stub_id),
 913       _stub_entry_point(nullptr),
 914       _max_node_limit(MaxNodeLimit),
 915       _post_loop_opts_phase(false),
 916       _merge_stores_phase(false),
 917       _allow_macro_nodes(true),
 918       _inlining_progress(false),
 919       _inlining_incrementally(false),
 920       _has_reserved_stack_access(false),
 921 #ifndef PRODUCT
 922       _igv_idx(0),
 923       _trace_opto_output(directive->TraceOptoOutputOption),
 924 #endif
 925       _clinit_barrier_on_entry(false),
 926       _stress_seed(0),
 927       _comp_arena(mtCompiler, Arena::Tag::tag_comp),
 928       _barrier_set_state(BarrierSet::barrier_set()->barrier_set_c2()->create_barrier_state(comp_arena())),
 929       _env(ci_env),
 930       _directive(directive),
 931       _log(ci_env->log()),
 932       _first_failure_details(nullptr),
 933       _for_post_loop_igvn(comp_arena(), 8, 0, nullptr),
 934       _for_merge_stores_igvn(comp_arena(), 8, 0, nullptr),
 935       _congraph(nullptr),
 936       NOT_PRODUCT(_igv_printer(nullptr) COMMA)
 937           _unique(0),
 938       _dead_node_count(0),
 939       _dead_node_list(comp_arena()),
 940       _node_arena_one(mtCompiler, Arena::Tag::tag_node),
 941       _node_arena_two(mtCompiler, Arena::Tag::tag_node),
 942       _node_arena(&_node_arena_one),
 943       _mach_constant_base_node(nullptr),
 944       _Compile_types(mtCompiler, Arena::Tag::tag_type),
 945       _initial_gvn(nullptr),
 946       _igvn_worklist(nullptr),
 947       _types(nullptr),
 948       _node_hash(nullptr),
 949       _has_mh_late_inlines(false),
 950       _oom(false),
 951       _replay_inline_data(nullptr),
 952       _inline_printer(this),
 953       _java_calls(0),
 954       _inner_loops(0),
 955       _FIRST_STACK_mask(comp_arena()),
 956       _interpreter_frame_size(0),
 957       _regmask_arena(mtCompiler, Arena::Tag::tag_regmask),
 958       _output(nullptr),
 959 #ifndef PRODUCT
 960       _in_dump_cnt(0),
 961 #endif
 962       _allowed_reasons(0) {
 963   C = this;
 964 
 965   // try to reuse an existing stub
 966   {
 967     BlobId blob_id = StubInfo::blob(_stub_id);
 968     CodeBlob* blob = AOTCodeCache::load_code_blob(AOTCodeEntry::C2Blob, blob_id);
 969     if (blob != nullptr) {
 970       RuntimeStub* rs = blob->as_runtime_stub();
 971       _stub_entry_point = rs->entry_point();
 972       return;
 973     }
 974   }
 975 
 976   TraceTime t1(nullptr, &_t_totalCompilation, CITime, false);
 977   TraceTime t2(nullptr, &_t_stubCompilation, CITime, false);
 978 
 979 #ifndef PRODUCT
 980   set_print_assembly(PrintFrameConverterAssembly);
 981   set_parsed_irreducible_loop(false);
 982 #else
 983   set_print_assembly(false); // Must initialize.
 984 #endif
 985   set_has_irreducible_loop(false); // no loops
 986 
 987   CompileWrapper cw(this);
 988   Init(/*do_aliasing=*/ false);
 989   init_tf((*generator)());
 990 
 991   _igvn_worklist = new (comp_arena()) Unique_Node_List(comp_arena());
 992   _types = new (comp_arena()) Type_Array(comp_arena());
 993   _node_hash = new (comp_arena()) NodeHash(comp_arena(), 255);
 994 
 995   if (StressLCM || StressGCM || StressBailout) {
 996     initialize_stress_seed(directive);
 997   }
 998 
 999   {
1000     PhaseGVN gvn;
1001     set_initial_gvn(&gvn);    // not significant, but GraphKit guys use it pervasively
1002     gvn.transform(top());
1003 
1004     GraphKit kit;
1005     kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
1006   }
1007 
1008   NOT_PRODUCT( verify_graph_edges(); )
1009 
1010   Code_Gen();
1011 }
1012 
1013 Compile::~Compile() {
1014   delete _first_failure_details;
1015 };
1016 
1017 //------------------------------Init-------------------------------------------
1018 // Prepare for a single compilation
1019 void Compile::Init(bool aliasing) {
1020   _do_aliasing = aliasing;
1021   _unique  = 0;
1022   _regalloc = nullptr;
1023 
1024   _tf      = nullptr;  // filled in later
1025   _top     = nullptr;  // cached later
1026   _matcher = nullptr;  // filled in later
1027   _cfg     = nullptr;  // filled in later
1028 
1029   _node_note_array = nullptr;
1030   _default_node_notes = nullptr;
1031   DEBUG_ONLY( _modified_nodes = nullptr; ) // Used in Optimize()
1032 
1033   _immutable_memory = nullptr; // filled in at first inquiry
1034 
1035 #ifdef ASSERT
1036   _phase_optimize_finished = false;
1037   _phase_verify_ideal_loop = false;
1038   _exception_backedge = false;
1039   _type_verify = nullptr;
1040 #endif
1041 
1042   // Globally visible Nodes
1043   // First set TOP to null to give safe behavior during creation of RootNode
1044   set_cached_top_node(nullptr);
1045   set_root(new RootNode());
1046   // Now that you have a Root to point to, create the real TOP
1047   set_cached_top_node( new ConNode(Type::TOP) );
1048   set_recent_alloc(nullptr, nullptr);
1049 
1050   // Create Debug Information Recorder to record scopes, oopmaps, etc.
1051   env()->set_oop_recorder(new OopRecorder(env()->arena()));
1052   env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
1053   env()->set_dependencies(new Dependencies(env()));
1054 
1055   _fixed_slots = 0;
1056   set_has_split_ifs(false);
1057   set_has_loops(false); // first approximation
1058   set_has_stringbuilder(false);
1059   set_has_boxed_value(false);
1060   _trap_can_recompile = false;  // no traps emitted yet
1061   _major_progress = true; // start out assuming good things will happen
1062   set_has_unsafe_access(false);
1063   set_max_vector_size(0);
1064   set_clear_upper_avx(false);  //false as default for clear upper bits of ymm registers
1065   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
1066   set_decompile_count(0);
1067 
1068 #ifndef PRODUCT
1069   _phase_counter = 0;
1070   Copy::zero_to_bytes(_igv_phase_iter, sizeof(_igv_phase_iter));
1071 #endif
1072 
1073   set_do_freq_based_layout(_directive->BlockLayoutByFrequencyOption);
1074   _loop_opts_cnt = LoopOptsCount;
1075   set_do_inlining(Inline);
1076   set_max_inline_size(MaxInlineSize);
1077   set_freq_inline_size(FreqInlineSize);
1078   set_do_scheduling(OptoScheduling);
1079 
1080   set_do_vector_loop(false);
1081   set_has_monitors(false);
1082   set_has_scoped_access(false);
1083 
1084   if (AllowVectorizeOnDemand) {
1085     if (has_method() && _directive->VectorizeOption) {
1086       set_do_vector_loop(true);
1087       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());})
1088     } else if (has_method() && method()->name() != nullptr &&
1089                method()->intrinsic_id() == vmIntrinsics::_forEachRemaining) {
1090       set_do_vector_loop(true);
1091     }
1092   }
1093   set_use_cmove(UseCMoveUnconditionally /* || do_vector_loop()*/); //TODO: consider do_vector_loop() mandate use_cmove unconditionally
1094   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());})
1095 
1096   _max_node_limit = _directive->MaxNodeLimitOption;
1097 
1098   if (VM_Version::supports_fast_class_init_checks() && has_method() && !is_osr_compilation() && method()->needs_clinit_barrier()) {
1099     set_clinit_barrier_on_entry(true);
1100   }
1101   if (debug_info()->recording_non_safepoints()) {
1102     set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
1103                         (comp_arena(), 8, 0, nullptr));
1104     set_default_node_notes(Node_Notes::make(this));
1105   }
1106 
1107   const int grow_ats = 16;
1108   _max_alias_types = grow_ats;
1109   _alias_types   = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
1110   AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType,  grow_ats);
1111   Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
1112   {
1113     for (int i = 0; i < grow_ats; i++)  _alias_types[i] = &ats[i];
1114   }
1115   // Initialize the first few types.
1116   _alias_types[AliasIdxTop]->Init(AliasIdxTop, nullptr);
1117   _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
1118   _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
1119   _num_alias_types = AliasIdxRaw+1;
1120   // Zero out the alias type cache.
1121   Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
1122   // A null adr_type hits in the cache right away.  Preload the right answer.
1123   probe_alias_cache(nullptr)->_index = AliasIdxTop;
1124 }
1125 
1126 #ifdef ASSERT
1127 // Verify that the current StartNode is valid.
1128 void Compile::verify_start(StartNode* s) const {
1129   assert(failing_internal() || s == start(), "should be StartNode");
1130 }
1131 #endif
1132 
1133 /**
1134  * Return the 'StartNode'. We must not have a pending failure, since the ideal graph
1135  * can be in an inconsistent state, i.e., we can get segmentation faults when traversing
1136  * the ideal graph.
1137  */
1138 StartNode* Compile::start() const {
1139   assert (!failing_internal() || C->failure_is_artificial(), "Must not have pending failure. Reason is: %s", failure_reason());
1140   for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
1141     Node* start = root()->fast_out(i);
1142     if (start->is_Start()) {
1143       return start->as_Start();
1144     }
1145   }
1146   fatal("Did not find Start node!");
1147   return nullptr;
1148 }
1149 
1150 //-------------------------------immutable_memory-------------------------------------
1151 // Access immutable memory
1152 Node* Compile::immutable_memory() {
1153   if (_immutable_memory != nullptr) {
1154     return _immutable_memory;
1155   }
1156   StartNode* s = start();
1157   for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
1158     Node *p = s->fast_out(i);
1159     if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
1160       _immutable_memory = p;
1161       return _immutable_memory;
1162     }
1163   }
1164   ShouldNotReachHere();
1165   return nullptr;
1166 }
1167 
1168 //----------------------set_cached_top_node------------------------------------
1169 // Install the cached top node, and make sure Node::is_top works correctly.
1170 void Compile::set_cached_top_node(Node* tn) {
1171   if (tn != nullptr)  verify_top(tn);
1172   Node* old_top = _top;
1173   _top = tn;
1174   // Calling Node::setup_is_top allows the nodes the chance to adjust
1175   // their _out arrays.
1176   if (_top != nullptr)     _top->setup_is_top();
1177   if (old_top != nullptr)  old_top->setup_is_top();
1178   assert(_top == nullptr || top()->is_top(), "");
1179 }
1180 
1181 #ifdef ASSERT
1182 uint Compile::count_live_nodes_by_graph_walk() {
1183   Unique_Node_List useful(comp_arena());
1184   // Get useful node list by walking the graph.
1185   identify_useful_nodes(useful);
1186   return useful.size();
1187 }
1188 
1189 void Compile::print_missing_nodes() {
1190 
1191   // Return if CompileLog is null and PrintIdealNodeCount is false.
1192   if ((_log == nullptr) && (! PrintIdealNodeCount)) {
1193     return;
1194   }
1195 
1196   // This is an expensive function. It is executed only when the user
1197   // specifies VerifyIdealNodeCount option or otherwise knows the
1198   // additional work that needs to be done to identify reachable nodes
1199   // by walking the flow graph and find the missing ones using
1200   // _dead_node_list.
1201 
1202   Unique_Node_List useful(comp_arena());
1203   // Get useful node list by walking the graph.
1204   identify_useful_nodes(useful);
1205 
1206   uint l_nodes = C->live_nodes();
1207   uint l_nodes_by_walk = useful.size();
1208 
1209   if (l_nodes != l_nodes_by_walk) {
1210     if (_log != nullptr) {
1211       _log->begin_head("mismatched_nodes count='%d'", abs((int) (l_nodes - l_nodes_by_walk)));
1212       _log->stamp();
1213       _log->end_head();
1214     }
1215     VectorSet& useful_member_set = useful.member_set();
1216     int last_idx = l_nodes_by_walk;
1217     for (int i = 0; i < last_idx; i++) {
1218       if (useful_member_set.test(i)) {
1219         if (_dead_node_list.test(i)) {
1220           if (_log != nullptr) {
1221             _log->elem("mismatched_node_info node_idx='%d' type='both live and dead'", i);
1222           }
1223           if (PrintIdealNodeCount) {
1224             // Print the log message to tty
1225               tty->print_cr("mismatched_node idx='%d' both live and dead'", i);
1226               useful.at(i)->dump();
1227           }
1228         }
1229       }
1230       else if (! _dead_node_list.test(i)) {
1231         if (_log != nullptr) {
1232           _log->elem("mismatched_node_info node_idx='%d' type='neither live nor dead'", i);
1233         }
1234         if (PrintIdealNodeCount) {
1235           // Print the log message to tty
1236           tty->print_cr("mismatched_node idx='%d' type='neither live nor dead'", i);
1237         }
1238       }
1239     }
1240     if (_log != nullptr) {
1241       _log->tail("mismatched_nodes");
1242     }
1243   }
1244 }
1245 void Compile::record_modified_node(Node* n) {
1246   if (_modified_nodes != nullptr && !_inlining_incrementally && !n->is_Con()) {
1247     _modified_nodes->push(n);
1248   }
1249 }
1250 
1251 void Compile::remove_modified_node(Node* n) {
1252   if (_modified_nodes != nullptr) {
1253     _modified_nodes->remove(n);
1254   }
1255 }
1256 #endif
1257 
1258 #ifndef PRODUCT
1259 void Compile::verify_top(Node* tn) const {
1260   if (tn != nullptr) {
1261     assert(tn->is_Con(), "top node must be a constant");
1262     assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
1263     assert(tn->in(0) != nullptr, "must have live top node");
1264   }
1265 }
1266 #endif
1267 
1268 
1269 ///-------------------Managing Per-Node Debug & Profile Info-------------------
1270 
1271 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
1272   guarantee(arr != nullptr, "");
1273   int num_blocks = arr->length();
1274   if (grow_by < num_blocks)  grow_by = num_blocks;
1275   int num_notes = grow_by * _node_notes_block_size;
1276   Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
1277   Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
1278   while (num_notes > 0) {
1279     arr->append(notes);
1280     notes     += _node_notes_block_size;
1281     num_notes -= _node_notes_block_size;
1282   }
1283   assert(num_notes == 0, "exact multiple, please");
1284 }
1285 
1286 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
1287   if (source == nullptr || dest == nullptr)  return false;
1288 
1289   if (dest->is_Con())
1290     return false;               // Do not push debug info onto constants.
1291 
1292 #ifdef ASSERT
1293   // Leave a bread crumb trail pointing to the original node:
1294   if (dest != nullptr && dest != source && dest->debug_orig() == nullptr) {
1295     dest->set_debug_orig(source);
1296   }
1297 #endif
1298 
1299   if (node_note_array() == nullptr)
1300     return false;               // Not collecting any notes now.
1301 
1302   // This is a copy onto a pre-existing node, which may already have notes.
1303   // If both nodes have notes, do not overwrite any pre-existing notes.
1304   Node_Notes* source_notes = node_notes_at(source->_idx);
1305   if (source_notes == nullptr || source_notes->is_clear())  return false;
1306   Node_Notes* dest_notes   = node_notes_at(dest->_idx);
1307   if (dest_notes == nullptr || dest_notes->is_clear()) {
1308     return set_node_notes_at(dest->_idx, source_notes);
1309   }
1310 
1311   Node_Notes merged_notes = (*source_notes);
1312   // The order of operations here ensures that dest notes will win...
1313   merged_notes.update_from(dest_notes);
1314   return set_node_notes_at(dest->_idx, &merged_notes);
1315 }
1316 
1317 
1318 //--------------------------allow_range_check_smearing-------------------------
1319 // Gating condition for coalescing similar range checks.
1320 // Sometimes we try 'speculatively' replacing a series of a range checks by a
1321 // single covering check that is at least as strong as any of them.
1322 // If the optimization succeeds, the simplified (strengthened) range check
1323 // will always succeed.  If it fails, we will deopt, and then give up
1324 // on the optimization.
1325 bool Compile::allow_range_check_smearing() const {
1326   // If this method has already thrown a range-check,
1327   // assume it was because we already tried range smearing
1328   // and it failed.
1329   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
1330   return !already_trapped;
1331 }
1332 
1333 
1334 //------------------------------flatten_alias_type-----------------------------
1335 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
1336   assert(do_aliasing(), "Aliasing should be enabled");
1337   int offset = tj->offset();
1338   TypePtr::PTR ptr = tj->ptr();
1339 
1340   // Known instance (scalarizable allocation) alias only with itself.
1341   bool is_known_inst = tj->isa_oopptr() != nullptr &&
1342                        tj->is_oopptr()->is_known_instance();
1343 
1344   // Process weird unsafe references.
1345   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
1346     assert(InlineUnsafeOps || StressReflectiveCode, "indeterminate pointers come only from unsafe ops");
1347     assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
1348     tj = TypeOopPtr::BOTTOM;
1349     ptr = tj->ptr();
1350     offset = tj->offset();
1351   }
1352 
1353   // Array pointers need some flattening
1354   const TypeAryPtr* ta = tj->isa_aryptr();
1355   if (ta && ta->is_stable()) {
1356     // Erase stability property for alias analysis.
1357     tj = ta = ta->cast_to_stable(false);
1358   }
1359   if( ta && is_known_inst ) {
1360     if ( offset != Type::OffsetBot &&
1361          offset > arrayOopDesc::length_offset_in_bytes() ) {
1362       offset = Type::OffsetBot; // Flatten constant access into array body only
1363       tj = ta = ta->
1364               remove_speculative()->
1365               cast_to_ptr_type(ptr)->
1366               with_offset(offset);
1367     }
1368   } else if (ta) {
1369     // For arrays indexed by constant indices, we flatten the alias
1370     // space to include all of the array body.  Only the header, klass
1371     // and array length can be accessed un-aliased.
1372     if( offset != Type::OffsetBot ) {
1373       if( ta->const_oop() ) { // MethodData* or Method*
1374         offset = Type::OffsetBot;   // Flatten constant access into array body
1375         tj = ta = ta->
1376                 remove_speculative()->
1377                 cast_to_ptr_type(ptr)->
1378                 cast_to_exactness(false)->
1379                 with_offset(offset);
1380       } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
1381         // range is OK as-is.
1382         tj = ta = TypeAryPtr::RANGE;
1383       } else if( offset == oopDesc::klass_offset_in_bytes() ) {
1384         tj = TypeInstPtr::KLASS; // all klass loads look alike
1385         ta = TypeAryPtr::RANGE; // generic ignored junk
1386         ptr = TypePtr::BotPTR;
1387       } else if( offset == oopDesc::mark_offset_in_bytes() ) {
1388         tj = TypeInstPtr::MARK;
1389         ta = TypeAryPtr::RANGE; // generic ignored junk
1390         ptr = TypePtr::BotPTR;
1391       } else {                  // Random constant offset into array body
1392         offset = Type::OffsetBot;   // Flatten constant access into array body
1393         tj = ta = ta->
1394                 remove_speculative()->
1395                 cast_to_ptr_type(ptr)->
1396                 cast_to_exactness(false)->
1397                 with_offset(offset);
1398       }
1399     }
1400     // Arrays of fixed size alias with arrays of unknown size.
1401     if (ta->size() != TypeInt::POS) {
1402       const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
1403       tj = ta = ta->
1404               remove_speculative()->
1405               cast_to_ptr_type(ptr)->
1406               with_ary(tary)->
1407               cast_to_exactness(false);
1408     }
1409     // Arrays of known objects become arrays of unknown objects.
1410     if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
1411       const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
1412       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,nullptr,false,offset);
1413     }
1414     if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
1415       const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
1416       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,nullptr,false,offset);
1417     }
1418     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
1419     // cannot be distinguished by bytecode alone.
1420     if (ta->elem() == TypeInt::BOOL) {
1421       const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
1422       ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
1423       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,offset);
1424     }
1425     // During the 2nd round of IterGVN, NotNull castings are removed.
1426     // Make sure the Bottom and NotNull variants alias the same.
1427     // Also, make sure exact and non-exact variants alias the same.
1428     if (ptr == TypePtr::NotNull || ta->klass_is_exact() || ta->speculative() != nullptr) {
1429       tj = ta = ta->
1430               remove_speculative()->
1431               cast_to_ptr_type(TypePtr::BotPTR)->
1432               cast_to_exactness(false)->
1433               with_offset(offset);
1434     }
1435   }
1436 
1437   // Oop pointers need some flattening
1438   const TypeInstPtr *to = tj->isa_instptr();
1439   if (to && to != TypeOopPtr::BOTTOM) {
1440     ciInstanceKlass* ik = to->instance_klass();
1441     if( ptr == TypePtr::Constant ) {
1442       if (ik != ciEnv::current()->Class_klass() ||
1443           offset < ik->layout_helper_size_in_bytes()) {
1444         // No constant oop pointers (such as Strings); they alias with
1445         // unknown strings.
1446         assert(!is_known_inst, "not scalarizable allocation");
1447         tj = to = to->
1448                 cast_to_instance_id(TypeOopPtr::InstanceBot)->
1449                 remove_speculative()->
1450                 cast_to_ptr_type(TypePtr::BotPTR)->
1451                 cast_to_exactness(false);
1452       }
1453     } else if( is_known_inst ) {
1454       tj = to; // Keep NotNull and klass_is_exact for instance type
1455     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
1456       // During the 2nd round of IterGVN, NotNull castings are removed.
1457       // Make sure the Bottom and NotNull variants alias the same.
1458       // Also, make sure exact and non-exact variants alias the same.
1459       tj = to = to->
1460               remove_speculative()->
1461               cast_to_instance_id(TypeOopPtr::InstanceBot)->
1462               cast_to_ptr_type(TypePtr::BotPTR)->
1463               cast_to_exactness(false);
1464     }
1465     if (to->speculative() != nullptr) {
1466       tj = to = to->remove_speculative();
1467     }
1468     // Canonicalize the holder of this field
1469     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
1470       // First handle header references such as a LoadKlassNode, even if the
1471       // object's klass is unloaded at compile time (4965979).
1472       if (!is_known_inst) { // Do it only for non-instance types
1473         tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, nullptr, offset);
1474       }
1475     } else if (offset < 0 || offset >= ik->layout_helper_size_in_bytes()) {
1476       // Static fields are in the space above the normal instance
1477       // fields in the java.lang.Class instance.
1478       if (ik != ciEnv::current()->Class_klass()) {
1479         to = nullptr;
1480         tj = TypeOopPtr::BOTTOM;
1481         offset = tj->offset();
1482       }
1483     } else {
1484       ciInstanceKlass *canonical_holder = ik->get_canonical_holder(offset);
1485       assert(offset < canonical_holder->layout_helper_size_in_bytes(), "");
1486       assert(tj->offset() == offset, "no change to offset expected");
1487       bool xk = to->klass_is_exact();
1488       int instance_id = to->instance_id();
1489 
1490       // If the input type's class is the holder: if exact, the type only includes interfaces implemented by the holder
1491       // but if not exact, it may include extra interfaces: build new type from the holder class to make sure only
1492       // its interfaces are included.
1493       if (xk && ik->equals(canonical_holder)) {
1494         assert(tj == TypeInstPtr::make(to->ptr(), canonical_holder, is_known_inst, nullptr, offset, instance_id), "exact type should be canonical type");
1495       } else {
1496         assert(xk || !is_known_inst, "Known instance should be exact type");
1497         tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, is_known_inst, nullptr, offset, instance_id);
1498       }
1499     }
1500   }
1501 
1502   // Klass pointers to object array klasses need some flattening
1503   const TypeKlassPtr *tk = tj->isa_klassptr();
1504   if( tk ) {
1505     // If we are referencing a field within a Klass, we need
1506     // to assume the worst case of an Object.  Both exact and
1507     // inexact types must flatten to the same alias class so
1508     // use NotNull as the PTR.
1509     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
1510       tj = tk = TypeInstKlassPtr::make(TypePtr::NotNull,
1511                                        env()->Object_klass(),
1512                                        offset);
1513     }
1514 
1515     if (tk->isa_aryklassptr() && tk->is_aryklassptr()->elem()->isa_klassptr()) {
1516       ciKlass* k = ciObjArrayKlass::make(env()->Object_klass());
1517       if (!k || !k->is_loaded()) {                  // Only fails for some -Xcomp runs
1518         tj = tk = TypeInstKlassPtr::make(TypePtr::NotNull, env()->Object_klass(), offset);
1519       } else {
1520         tj = tk = TypeAryKlassPtr::make(TypePtr::NotNull, tk->is_aryklassptr()->elem(), k, offset);
1521       }
1522     }
1523 
1524     // Check for precise loads from the primary supertype array and force them
1525     // to the supertype cache alias index.  Check for generic array loads from
1526     // the primary supertype array and also force them to the supertype cache
1527     // alias index.  Since the same load can reach both, we need to merge
1528     // these 2 disparate memories into the same alias class.  Since the
1529     // primary supertype array is read-only, there's no chance of confusion
1530     // where we bypass an array load and an array store.
1531     int primary_supers_offset = in_bytes(Klass::primary_supers_offset());
1532     if (offset == Type::OffsetBot ||
1533         (offset >= primary_supers_offset &&
1534          offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
1535         offset == (int)in_bytes(Klass::secondary_super_cache_offset())) {
1536       offset = in_bytes(Klass::secondary_super_cache_offset());
1537       tj = tk = tk->with_offset(offset);
1538     }
1539   }
1540 
1541   // Flatten all Raw pointers together.
1542   if (tj->base() == Type::RawPtr)
1543     tj = TypeRawPtr::BOTTOM;
1544 
1545   if (tj->base() == Type::AnyPtr)
1546     tj = TypePtr::BOTTOM;      // An error, which the caller must check for.
1547 
1548   offset = tj->offset();
1549   assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
1550 
1551   assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
1552           (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
1553           (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
1554           (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
1555           (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1556           (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1557           (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr),
1558           "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
1559   assert( tj->ptr() != TypePtr::TopPTR &&
1560           tj->ptr() != TypePtr::AnyNull &&
1561           tj->ptr() != TypePtr::Null, "No imprecise addresses" );
1562 //    assert( tj->ptr() != TypePtr::Constant ||
1563 //            tj->base() == Type::RawPtr ||
1564 //            tj->base() == Type::KlassPtr, "No constant oop addresses" );
1565 
1566   return tj;
1567 }
1568 
1569 void Compile::AliasType::Init(int i, const TypePtr* at) {
1570   assert(AliasIdxTop <= i && i < Compile::current()->_max_alias_types, "Invalid alias index");
1571   _index = i;
1572   _adr_type = at;
1573   _field = nullptr;
1574   _element = nullptr;
1575   _is_rewritable = true; // default
1576   const TypeOopPtr *atoop = (at != nullptr) ? at->isa_oopptr() : nullptr;
1577   if (atoop != nullptr && atoop->is_known_instance()) {
1578     const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
1579     _general_index = Compile::current()->get_alias_index(gt);
1580   } else {
1581     _general_index = 0;
1582   }
1583 }
1584 
1585 BasicType Compile::AliasType::basic_type() const {
1586   if (element() != nullptr) {
1587     const Type* element = adr_type()->is_aryptr()->elem();
1588     return element->isa_narrowoop() ? T_OBJECT : element->array_element_basic_type();
1589   } if (field() != nullptr) {
1590     return field()->layout_type();
1591   } else {
1592     return T_ILLEGAL; // unknown
1593   }
1594 }
1595 
1596 //---------------------------------print_on------------------------------------
1597 #ifndef PRODUCT
1598 void Compile::AliasType::print_on(outputStream* st) {
1599   if (index() < 10)
1600         st->print("@ <%d> ", index());
1601   else  st->print("@ <%d>",  index());
1602   st->print(is_rewritable() ? "   " : " RO");
1603   int offset = adr_type()->offset();
1604   if (offset == Type::OffsetBot)
1605         st->print(" +any");
1606   else  st->print(" +%-3d", offset);
1607   st->print(" in ");
1608   adr_type()->dump_on(st);
1609   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
1610   if (field() != nullptr && tjp) {
1611     if (tjp->is_instptr()->instance_klass()  != field()->holder() ||
1612         tjp->offset() != field()->offset_in_bytes()) {
1613       st->print(" != ");
1614       field()->print();
1615       st->print(" ***");
1616     }
1617   }
1618 }
1619 
1620 void print_alias_types() {
1621   Compile* C = Compile::current();
1622   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
1623   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
1624     C->alias_type(idx)->print_on(tty);
1625     tty->cr();
1626   }
1627 }
1628 #endif
1629 
1630 
1631 //----------------------------probe_alias_cache--------------------------------
1632 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
1633   intptr_t key = (intptr_t) adr_type;
1634   key ^= key >> logAliasCacheSize;
1635   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
1636 }
1637 
1638 
1639 //-----------------------------grow_alias_types--------------------------------
1640 void Compile::grow_alias_types() {
1641   const int old_ats  = _max_alias_types; // how many before?
1642   const int new_ats  = old_ats;          // how many more?
1643   const int grow_ats = old_ats+new_ats;  // how many now?
1644   _max_alias_types = grow_ats;
1645   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
1646   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
1647   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
1648   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
1649 }
1650 
1651 
1652 //--------------------------------find_alias_type------------------------------
1653 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field) {
1654   if (!do_aliasing()) {
1655     return alias_type(AliasIdxBot);
1656   }
1657 
1658   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1659   if (ace->_adr_type == adr_type) {
1660     return alias_type(ace->_index);
1661   }
1662 
1663   // Handle special cases.
1664   if (adr_type == nullptr)          return alias_type(AliasIdxTop);
1665   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
1666 
1667   // Do it the slow way.
1668   const TypePtr* flat = flatten_alias_type(adr_type);
1669 
1670 #ifdef ASSERT
1671   {
1672     ResourceMark rm;
1673     assert(flat == flatten_alias_type(flat), "not idempotent: adr_type = %s; flat = %s => %s",
1674            Type::str(adr_type), Type::str(flat), Type::str(flatten_alias_type(flat)));
1675     assert(flat != TypePtr::BOTTOM, "cannot alias-analyze an untyped ptr: adr_type = %s",
1676            Type::str(adr_type));
1677     if (flat->isa_oopptr() && !flat->isa_klassptr()) {
1678       const TypeOopPtr* foop = flat->is_oopptr();
1679       // Scalarizable allocations have exact klass always.
1680       bool exact = !foop->klass_is_exact() || foop->is_known_instance();
1681       const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
1682       assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type: foop = %s; xoop = %s",
1683              Type::str(foop), Type::str(xoop));
1684     }
1685   }
1686 #endif
1687 
1688   int idx = AliasIdxTop;
1689   for (int i = 0; i < num_alias_types(); i++) {
1690     if (alias_type(i)->adr_type() == flat) {
1691       idx = i;
1692       break;
1693     }
1694   }
1695 
1696   if (idx == AliasIdxTop) {
1697     if (no_create)  return nullptr;
1698     // Grow the array if necessary.
1699     if (_num_alias_types == _max_alias_types)  grow_alias_types();
1700     // Add a new alias type.
1701     idx = _num_alias_types++;
1702     _alias_types[idx]->Init(idx, flat);
1703     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
1704     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
1705     if (flat->isa_instptr()) {
1706       if (flat->offset() == java_lang_Class::klass_offset()
1707           && flat->is_instptr()->instance_klass() == env()->Class_klass())
1708         alias_type(idx)->set_rewritable(false);
1709     }
1710     if (flat->isa_aryptr()) {
1711 #ifdef ASSERT
1712       const int header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1713       // (T_BYTE has the weakest alignment and size restrictions...)
1714       assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
1715 #endif
1716       if (flat->offset() == TypePtr::OffsetBot) {
1717         alias_type(idx)->set_element(flat->is_aryptr()->elem());
1718       }
1719     }
1720     if (flat->isa_klassptr()) {
1721       if (UseCompactObjectHeaders) {
1722         if (flat->offset() == in_bytes(Klass::prototype_header_offset()))
1723           alias_type(idx)->set_rewritable(false);
1724       }
1725       if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
1726         alias_type(idx)->set_rewritable(false);
1727       if (flat->offset() == in_bytes(Klass::misc_flags_offset()))
1728         alias_type(idx)->set_rewritable(false);
1729       if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
1730         alias_type(idx)->set_rewritable(false);
1731       if (flat->offset() == in_bytes(Klass::secondary_super_cache_offset()))
1732         alias_type(idx)->set_rewritable(false);
1733     }
1734 
1735     if (flat->isa_instklassptr()) {
1736       if (flat->offset() == in_bytes(InstanceKlass::access_flags_offset())) {
1737         alias_type(idx)->set_rewritable(false);
1738       }
1739     }
1740     // %%% (We would like to finalize JavaThread::threadObj_offset(),
1741     // but the base pointer type is not distinctive enough to identify
1742     // references into JavaThread.)
1743 
1744     // Check for final fields.
1745     const TypeInstPtr* tinst = flat->isa_instptr();
1746     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
1747       ciField* field;
1748       if (tinst->const_oop() != nullptr &&
1749           tinst->instance_klass() == ciEnv::current()->Class_klass() &&
1750           tinst->offset() >= (tinst->instance_klass()->layout_helper_size_in_bytes())) {
1751         // static field
1752         ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
1753         field = k->get_field_by_offset(tinst->offset(), true);
1754       } else {
1755         ciInstanceKlass *k = tinst->instance_klass();
1756         field = k->get_field_by_offset(tinst->offset(), false);
1757       }
1758       assert(field == nullptr ||
1759              original_field == nullptr ||
1760              (field->holder() == original_field->holder() &&
1761               field->offset_in_bytes() == original_field->offset_in_bytes() &&
1762               field->is_static() == original_field->is_static()), "wrong field?");
1763       // Set field() and is_rewritable() attributes.
1764       if (field != nullptr)  alias_type(idx)->set_field(field);
1765     }
1766   }
1767 
1768   // Fill the cache for next time.
1769   ace->_adr_type = adr_type;
1770   ace->_index    = idx;
1771   assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
1772 
1773   // Might as well try to fill the cache for the flattened version, too.
1774   AliasCacheEntry* face = probe_alias_cache(flat);
1775   if (face->_adr_type == nullptr) {
1776     face->_adr_type = flat;
1777     face->_index    = idx;
1778     assert(alias_type(flat) == alias_type(idx), "flat type must work too");
1779   }
1780 
1781   return alias_type(idx);
1782 }
1783 
1784 
1785 Compile::AliasType* Compile::alias_type(ciField* field) {
1786   const TypeOopPtr* t;
1787   if (field->is_static())
1788     t = TypeInstPtr::make(field->holder()->java_mirror());
1789   else
1790     t = TypeOopPtr::make_from_klass_raw(field->holder());
1791   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);
1792   assert((field->is_final() || field->is_stable()) == !atp->is_rewritable(), "must get the rewritable bits correct");
1793   return atp;
1794 }
1795 
1796 
1797 //------------------------------have_alias_type--------------------------------
1798 bool Compile::have_alias_type(const TypePtr* adr_type) {
1799   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1800   if (ace->_adr_type == adr_type) {
1801     return true;
1802   }
1803 
1804   // Handle special cases.
1805   if (adr_type == nullptr)             return true;
1806   if (adr_type == TypePtr::BOTTOM)  return true;
1807 
1808   return find_alias_type(adr_type, true, nullptr) != nullptr;
1809 }
1810 
1811 //-----------------------------must_alias--------------------------------------
1812 // True if all values of the given address type are in the given alias category.
1813 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
1814   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1815   if (adr_type == nullptr)              return true;  // null serves as TypePtr::TOP
1816   if (alias_idx == AliasIdxTop)         return false; // the empty category
1817   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
1818 
1819   // the only remaining possible overlap is identity
1820   int adr_idx = get_alias_index(adr_type);
1821   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1822   assert(adr_idx == alias_idx ||
1823          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
1824           && adr_type                       != TypeOopPtr::BOTTOM),
1825          "should not be testing for overlap with an unsafe pointer");
1826   return adr_idx == alias_idx;
1827 }
1828 
1829 //------------------------------can_alias--------------------------------------
1830 // True if any values of the given address type are in the given alias category.
1831 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
1832   if (alias_idx == AliasIdxTop)         return false; // the empty category
1833   if (adr_type == nullptr)              return false; // null serves as TypePtr::TOP
1834   // Known instance doesn't alias with bottom memory
1835   if (alias_idx == AliasIdxBot)         return !adr_type->is_known_instance();                   // the universal category
1836   if (adr_type->base() == Type::AnyPtr) return !C->get_adr_type(alias_idx)->is_known_instance(); // TypePtr::BOTTOM or its twins
1837 
1838   // the only remaining possible overlap is identity
1839   int adr_idx = get_alias_index(adr_type);
1840   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1841   return adr_idx == alias_idx;
1842 }
1843 
1844 // Mark all ParsePredicateNodes as useless. They will later be removed from the graph in IGVN together with their
1845 // uncommon traps if no Runtime Predicates were created from the Parse Predicates.
1846 void Compile::mark_parse_predicate_nodes_useless(PhaseIterGVN& igvn) {
1847   if (parse_predicate_count() == 0) {
1848     return;
1849   }
1850   for (int i = 0; i < parse_predicate_count(); i++) {
1851     ParsePredicateNode* parse_predicate = _parse_predicates.at(i);
1852     parse_predicate->mark_useless(igvn);
1853   }
1854   _parse_predicates.clear();
1855 }
1856 
1857 void Compile::record_for_post_loop_opts_igvn(Node* n) {
1858   if (!n->for_post_loop_opts_igvn()) {
1859     assert(!_for_post_loop_igvn.contains(n), "duplicate");
1860     n->add_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
1861     _for_post_loop_igvn.append(n);
1862   }
1863 }
1864 
1865 void Compile::remove_from_post_loop_opts_igvn(Node* n) {
1866   n->remove_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
1867   _for_post_loop_igvn.remove(n);
1868 }
1869 
1870 void Compile::process_for_post_loop_opts_igvn(PhaseIterGVN& igvn) {
1871   // Verify that all previous optimizations produced a valid graph
1872   // at least to this point, even if no loop optimizations were done.
1873   PhaseIdealLoop::verify(igvn);
1874 
1875   if (has_loops() || _loop_opts_cnt > 0) {
1876     print_method(PHASE_AFTER_LOOP_OPTS, 2);
1877   }
1878   C->set_post_loop_opts_phase(); // no more loop opts allowed
1879 
1880   assert(!C->major_progress(), "not cleared");
1881 
1882   if (_for_post_loop_igvn.length() > 0) {
1883     while (_for_post_loop_igvn.length() > 0) {
1884       Node* n = _for_post_loop_igvn.pop();
1885       n->remove_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
1886       igvn._worklist.push(n);
1887     }
1888     igvn.optimize();
1889     if (failing()) return;
1890     assert(_for_post_loop_igvn.length() == 0, "no more delayed nodes allowed");
1891     assert(C->parse_predicate_count() == 0, "all parse predicates should have been removed now");
1892 
1893     // Sometimes IGVN sets major progress (e.g., when processing loop nodes).
1894     if (C->major_progress()) {
1895       C->clear_major_progress(); // ensure that major progress is now clear
1896     }
1897   }
1898 }
1899 
1900 void Compile::record_for_merge_stores_igvn(Node* n) {
1901   if (!n->for_merge_stores_igvn()) {
1902     assert(!_for_merge_stores_igvn.contains(n), "duplicate");
1903     n->add_flag(Node::NodeFlags::Flag_for_merge_stores_igvn);
1904     _for_merge_stores_igvn.append(n);
1905   }
1906 }
1907 
1908 void Compile::remove_from_merge_stores_igvn(Node* n) {
1909   n->remove_flag(Node::NodeFlags::Flag_for_merge_stores_igvn);
1910   _for_merge_stores_igvn.remove(n);
1911 }
1912 
1913 // We need to wait with merging stores until RangeCheck smearing has removed the RangeChecks during
1914 // the post loops IGVN phase. If we do it earlier, then there may still be some RangeChecks between
1915 // the stores, and we merge the wrong sequence of stores.
1916 // Example:
1917 //   StoreI RangeCheck StoreI StoreI RangeCheck StoreI
1918 // Apply MergeStores:
1919 //   StoreI RangeCheck [   StoreL  ] RangeCheck StoreI
1920 // Remove more RangeChecks:
1921 //   StoreI            [   StoreL  ]            StoreI
1922 // But now it would have been better to do this instead:
1923 //   [         StoreL       ] [       StoreL         ]
1924 //
1925 // Note: we allow stores to merge in this dedicated IGVN round, and any later IGVN round,
1926 //       since we never unset _merge_stores_phase.
1927 void Compile::process_for_merge_stores_igvn(PhaseIterGVN& igvn) {
1928   C->set_merge_stores_phase();
1929 
1930   if (_for_merge_stores_igvn.length() > 0) {
1931     while (_for_merge_stores_igvn.length() > 0) {
1932       Node* n = _for_merge_stores_igvn.pop();
1933       n->remove_flag(Node::NodeFlags::Flag_for_merge_stores_igvn);
1934       igvn._worklist.push(n);
1935     }
1936     igvn.optimize();
1937     if (failing()) return;
1938     assert(_for_merge_stores_igvn.length() == 0, "no more delayed nodes allowed");
1939     print_method(PHASE_AFTER_MERGE_STORES, 3);
1940   }
1941 }
1942 
1943 void Compile::record_unstable_if_trap(UnstableIfTrap* trap) {
1944   if (OptimizeUnstableIf) {
1945     _unstable_if_traps.append(trap);
1946   }
1947 }
1948 
1949 void Compile::remove_useless_unstable_if_traps(Unique_Node_List& useful) {
1950   for (int i = _unstable_if_traps.length() - 1; i >= 0; i--) {
1951     UnstableIfTrap* trap = _unstable_if_traps.at(i);
1952     Node* n = trap->uncommon_trap();
1953     if (!useful.member(n)) {
1954       _unstable_if_traps.delete_at(i); // replaces i-th with last element which is known to be useful (already processed)
1955     }
1956   }
1957 }
1958 
1959 // Remove the unstable if trap associated with 'unc' from candidates. It is either dead
1960 // or fold-compares case. Return true if succeed or not found.
1961 //
1962 // In rare cases, the found trap has been processed. It is too late to delete it. Return
1963 // false and ask fold-compares to yield.
1964 //
1965 // 'fold-compares' may use the uncommon_trap of the dominating IfNode to cover the fused
1966 // IfNode. This breaks the unstable_if trap invariant: control takes the unstable path
1967 // when deoptimization does happen.
1968 bool Compile::remove_unstable_if_trap(CallStaticJavaNode* unc, bool yield) {
1969   for (int i = 0; i < _unstable_if_traps.length(); ++i) {
1970     UnstableIfTrap* trap = _unstable_if_traps.at(i);
1971     if (trap->uncommon_trap() == unc) {
1972       if (yield && trap->modified()) {
1973         return false;
1974       }
1975       _unstable_if_traps.delete_at(i);
1976       break;
1977     }
1978   }
1979   return true;
1980 }
1981 
1982 // Re-calculate unstable_if traps with the liveness of next_bci, which points to the unlikely path.
1983 // It needs to be done after igvn because fold-compares may fuse uncommon_traps and before renumbering.
1984 void Compile::process_for_unstable_if_traps(PhaseIterGVN& igvn) {
1985   for (int i = _unstable_if_traps.length() - 1; i >= 0; --i) {
1986     UnstableIfTrap* trap = _unstable_if_traps.at(i);
1987     CallStaticJavaNode* unc = trap->uncommon_trap();
1988     int next_bci = trap->next_bci();
1989     bool modified = trap->modified();
1990 
1991     if (next_bci != -1 && !modified) {
1992       assert(!_dead_node_list.test(unc->_idx), "changing a dead node!");
1993       JVMState* jvms = unc->jvms();
1994       ciMethod* method = jvms->method();
1995       ciBytecodeStream iter(method);
1996 
1997       iter.force_bci(jvms->bci());
1998       assert(next_bci == iter.next_bci() || next_bci == iter.get_dest(), "wrong next_bci at unstable_if");
1999       Bytecodes::Code c = iter.cur_bc();
2000       Node* lhs = nullptr;
2001       Node* rhs = nullptr;
2002       if (c == Bytecodes::_if_acmpeq || c == Bytecodes::_if_acmpne) {
2003         lhs = unc->peek_operand(0);
2004         rhs = unc->peek_operand(1);
2005       } else if (c == Bytecodes::_ifnull || c == Bytecodes::_ifnonnull) {
2006         lhs = unc->peek_operand(0);
2007       }
2008 
2009       ResourceMark rm;
2010       const MethodLivenessResult& live_locals = method->liveness_at_bci(next_bci);
2011       assert(live_locals.is_valid(), "broken liveness info");
2012       int len = (int)live_locals.size();
2013 
2014       for (int i = 0; i < len; i++) {
2015         Node* local = unc->local(jvms, i);
2016         // kill local using the liveness of next_bci.
2017         // give up when the local looks like an operand to secure reexecution.
2018         if (!live_locals.at(i) && !local->is_top() && local != lhs && local!= rhs) {
2019           uint idx = jvms->locoff() + i;
2020 #ifdef ASSERT
2021           if (PrintOpto && Verbose) {
2022             tty->print("[unstable_if] kill local#%d: ", idx);
2023             local->dump();
2024             tty->cr();
2025           }
2026 #endif
2027           igvn.replace_input_of(unc, idx, top());
2028           modified = true;
2029         }
2030       }
2031     }
2032 
2033     // keep the mondified trap for late query
2034     if (modified) {
2035       trap->set_modified();
2036     } else {
2037       _unstable_if_traps.delete_at(i);
2038     }
2039   }
2040   igvn.optimize();
2041 }
2042 
2043 // StringOpts and late inlining of string methods
2044 void Compile::inline_string_calls(bool parse_time) {
2045   {
2046     // remove useless nodes to make the usage analysis simpler
2047     ResourceMark rm;
2048     PhaseRemoveUseless pru(initial_gvn(), *igvn_worklist());
2049   }
2050 
2051   {
2052     ResourceMark rm;
2053     print_method(PHASE_BEFORE_STRINGOPTS, 3);
2054     PhaseStringOpts pso(initial_gvn());
2055     print_method(PHASE_AFTER_STRINGOPTS, 3);
2056   }
2057 
2058   // now inline anything that we skipped the first time around
2059   if (!parse_time) {
2060     _late_inlines_pos = _late_inlines.length();
2061   }
2062 
2063   while (_string_late_inlines.length() > 0) {
2064     CallGenerator* cg = _string_late_inlines.pop();
2065     cg->do_late_inline();
2066     if (failing())  return;
2067   }
2068   _string_late_inlines.trunc_to(0);
2069 }
2070 
2071 // Late inlining of boxing methods
2072 void Compile::inline_boxing_calls(PhaseIterGVN& igvn) {
2073   if (_boxing_late_inlines.length() > 0) {
2074     assert(has_boxed_value(), "inconsistent");
2075 
2076     set_inlining_incrementally(true);
2077 
2078     igvn_worklist()->ensure_empty(); // should be done with igvn
2079 
2080     _late_inlines_pos = _late_inlines.length();
2081 
2082     while (_boxing_late_inlines.length() > 0) {
2083       CallGenerator* cg = _boxing_late_inlines.pop();
2084       cg->do_late_inline();
2085       if (failing())  return;
2086     }
2087     _boxing_late_inlines.trunc_to(0);
2088 
2089     inline_incrementally_cleanup(igvn);
2090 
2091     set_inlining_incrementally(false);
2092   }
2093 }
2094 
2095 bool Compile::inline_incrementally_one() {
2096   assert(IncrementalInline, "incremental inlining should be on");
2097 
2098   TracePhase tp(_t_incrInline_inline);
2099 
2100   set_inlining_progress(false);
2101   set_do_cleanup(false);
2102 
2103   for (int i = 0; i < _late_inlines.length(); i++) {
2104     _late_inlines_pos = i+1;
2105     CallGenerator* cg = _late_inlines.at(i);
2106     bool is_scheduled_for_igvn_before = C->igvn_worklist()->member(cg->call_node());
2107     bool does_dispatch = cg->is_virtual_late_inline() || cg->is_mh_late_inline();
2108     if (inlining_incrementally() || does_dispatch) { // a call can be either inlined or strength-reduced to a direct call
2109       if (should_stress_inlining()) {
2110         // randomly add repeated inline attempt if stress-inlining
2111         cg->call_node()->set_generator(cg);
2112         C->igvn_worklist()->push(cg->call_node());
2113         continue;
2114       }
2115       cg->do_late_inline();
2116       assert(_late_inlines.at(i) == cg, "no insertions before current position allowed");
2117       if (failing()) {
2118         return false;
2119       } else if (inlining_progress()) {
2120         _late_inlines_pos = i+1; // restore the position in case new elements were inserted
2121         print_method(PHASE_INCREMENTAL_INLINE_STEP, 3, cg->call_node());
2122         break; // process one call site at a time
2123       } else {
2124         bool is_scheduled_for_igvn_after = C->igvn_worklist()->member(cg->call_node());
2125         if (!is_scheduled_for_igvn_before && is_scheduled_for_igvn_after) {
2126           // Avoid potential infinite loop if node already in the IGVN list
2127           assert(false, "scheduled for IGVN during inlining attempt");
2128         } else {
2129           // Ensure call node has not disappeared from IGVN worklist during a failed inlining attempt
2130           assert(!is_scheduled_for_igvn_before || is_scheduled_for_igvn_after, "call node removed from IGVN list during inlining pass");
2131           cg->call_node()->set_generator(cg);
2132         }
2133       }
2134     } else {
2135       // Ignore late inline direct calls when inlining is not allowed.
2136       // They are left in the late inline list when node budget is exhausted until the list is fully drained.
2137     }
2138   }
2139   // Remove processed elements.
2140   _late_inlines.remove_till(_late_inlines_pos);
2141   _late_inlines_pos = 0;
2142 
2143   assert(inlining_progress() || _late_inlines.length() == 0, "no progress");
2144 
2145   bool needs_cleanup = do_cleanup() || over_inlining_cutoff();
2146 
2147   set_inlining_progress(false);
2148   set_do_cleanup(false);
2149 
2150   bool force_cleanup = directive()->IncrementalInlineForceCleanupOption;
2151   return (_late_inlines.length() > 0) && !needs_cleanup && !force_cleanup;
2152 }
2153 
2154 void Compile::inline_incrementally_cleanup(PhaseIterGVN& igvn) {
2155   {
2156     TracePhase tp(_t_incrInline_pru);
2157     ResourceMark rm;
2158     PhaseRemoveUseless pru(initial_gvn(), *igvn_worklist());
2159   }
2160   {
2161     TracePhase tp(_t_incrInline_igvn);
2162     igvn.reset();
2163     igvn.optimize();
2164     if (failing()) return;
2165   }
2166   print_method(PHASE_INCREMENTAL_INLINE_CLEANUP, 3);
2167 }
2168 
2169 // Perform incremental inlining until bound on number of live nodes is reached
2170 void Compile::inline_incrementally(PhaseIterGVN& igvn) {
2171   TracePhase tp(_t_incrInline);
2172 
2173   set_inlining_incrementally(true);
2174   uint low_live_nodes = 0;
2175 
2176   while (_late_inlines.length() > 0) {
2177     if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2178       if (low_live_nodes < (uint)LiveNodeCountInliningCutoff * 8 / 10) {
2179         TracePhase tp(_t_incrInline_ideal);
2180         // PhaseIdealLoop is expensive so we only try it once we are
2181         // out of live nodes and we only try it again if the previous
2182         // helped got the number of nodes down significantly
2183         PhaseIdealLoop::optimize(igvn, LoopOptsNone);
2184         if (failing())  return;
2185         low_live_nodes = live_nodes();
2186         _major_progress = true;
2187       }
2188 
2189       if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2190         bool do_print_inlining = print_inlining() || print_intrinsics();
2191         if (do_print_inlining || log() != nullptr) {
2192           // Print inlining message for candidates that we couldn't inline for lack of space.
2193           for (int i = 0; i < _late_inlines.length(); i++) {
2194             CallGenerator* cg = _late_inlines.at(i);
2195             const char* msg = "live nodes > LiveNodeCountInliningCutoff";
2196             if (do_print_inlining) {
2197               inline_printer()->record(cg->method(), cg->call_node()->jvms(), InliningResult::FAILURE, msg);
2198             }
2199             log_late_inline_failure(cg, msg);
2200           }
2201         }
2202         break; // finish
2203       }
2204     }
2205 
2206     igvn_worklist()->ensure_empty(); // should be done with igvn
2207 
2208     while (inline_incrementally_one()) {
2209       assert(!failing_internal() || failure_is_artificial(), "inconsistent");
2210     }
2211     if (failing())  return;
2212 
2213     inline_incrementally_cleanup(igvn);
2214 
2215     print_method(PHASE_INCREMENTAL_INLINE_STEP, 3);
2216 
2217     if (failing())  return;
2218 
2219     if (_late_inlines.length() == 0) {
2220       break; // no more progress
2221     }
2222   }
2223 
2224   igvn_worklist()->ensure_empty(); // should be done with igvn
2225 
2226   if (_string_late_inlines.length() > 0) {
2227     assert(has_stringbuilder(), "inconsistent");
2228 
2229     inline_string_calls(false);
2230 
2231     if (failing())  return;
2232 
2233     inline_incrementally_cleanup(igvn);
2234   }
2235 
2236   set_inlining_incrementally(false);
2237 }
2238 
2239 void Compile::process_late_inline_calls_no_inline(PhaseIterGVN& igvn) {
2240   // "inlining_incrementally() == false" is used to signal that no inlining is allowed
2241   // (see LateInlineVirtualCallGenerator::do_late_inline_check() for details).
2242   // Tracking and verification of modified nodes is disabled by setting "_modified_nodes == nullptr"
2243   // as if "inlining_incrementally() == true" were set.
2244   assert(inlining_incrementally() == false, "not allowed");
2245   assert(_modified_nodes == nullptr, "not allowed");
2246   assert(_late_inlines.length() > 0, "sanity");
2247 
2248   while (_late_inlines.length() > 0) {
2249     igvn_worklist()->ensure_empty(); // should be done with igvn
2250 
2251     while (inline_incrementally_one()) {
2252       assert(!failing_internal() || failure_is_artificial(), "inconsistent");
2253     }
2254     if (failing())  return;
2255 
2256     inline_incrementally_cleanup(igvn);
2257   }
2258 }
2259 
2260 bool Compile::optimize_loops(PhaseIterGVN& igvn, LoopOptsMode mode) {
2261   if (_loop_opts_cnt > 0) {
2262     while (major_progress() && (_loop_opts_cnt > 0)) {
2263       TracePhase tp(_t_idealLoop);
2264       PhaseIdealLoop::optimize(igvn, mode);
2265       _loop_opts_cnt--;
2266       if (failing())  return false;
2267       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
2268     }
2269   }
2270   return true;
2271 }
2272 
2273 // Remove edges from "root" to each SafePoint at a backward branch.
2274 // They were inserted during parsing (see add_safepoint()) to make
2275 // infinite loops without calls or exceptions visible to root, i.e.,
2276 // useful.
2277 void Compile::remove_root_to_sfpts_edges(PhaseIterGVN& igvn) {
2278   Node *r = root();
2279   if (r != nullptr) {
2280     for (uint i = r->req(); i < r->len(); ++i) {
2281       Node *n = r->in(i);
2282       if (n != nullptr && n->is_SafePoint()) {
2283         r->rm_prec(i);
2284         if (n->outcnt() == 0) {
2285           igvn.remove_dead_node(n);
2286         }
2287         --i;
2288       }
2289     }
2290     // Parsing may have added top inputs to the root node (Path
2291     // leading to the Halt node proven dead). Make sure we get a
2292     // chance to clean them up.
2293     igvn._worklist.push(r);
2294     igvn.optimize();
2295   }
2296 }
2297 
2298 //------------------------------Optimize---------------------------------------
2299 // Given a graph, optimize it.
2300 void Compile::Optimize() {
2301   TracePhase tp(_t_optimizer);
2302 
2303 #ifndef PRODUCT
2304   if (env()->break_at_compile()) {
2305     BREAKPOINT;
2306   }
2307 
2308 #endif
2309 
2310   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
2311 #ifdef ASSERT
2312   bs->verify_gc_barriers(this, BarrierSetC2::BeforeOptimize);
2313 #endif
2314 
2315   ResourceMark rm;
2316 
2317   NOT_PRODUCT( verify_graph_edges(); )
2318 
2319   print_method(PHASE_AFTER_PARSING, 1);
2320 
2321  {
2322   // Iterative Global Value Numbering, including ideal transforms
2323   PhaseIterGVN igvn;
2324 #ifdef ASSERT
2325   _modified_nodes = new (comp_arena()) Unique_Node_List(comp_arena());
2326 #endif
2327   {
2328     TracePhase tp(_t_iterGVN);
2329     igvn.optimize();
2330   }
2331 
2332   if (failing())  return;
2333 
2334   print_method(PHASE_ITER_GVN1, 2);
2335 
2336   process_for_unstable_if_traps(igvn);
2337 
2338   if (failing())  return;
2339 
2340   inline_incrementally(igvn);
2341 
2342   print_method(PHASE_INCREMENTAL_INLINE, 2);
2343 
2344   if (failing())  return;
2345 
2346   if (eliminate_boxing()) {
2347     // Inline valueOf() methods now.
2348     inline_boxing_calls(igvn);
2349 
2350     if (failing())  return;
2351 
2352     if (AlwaysIncrementalInline || StressIncrementalInlining) {
2353       inline_incrementally(igvn);
2354     }
2355 
2356     print_method(PHASE_INCREMENTAL_BOXING_INLINE, 2);
2357 
2358     if (failing())  return;
2359   }
2360 
2361   // Remove the speculative part of types and clean up the graph from
2362   // the extra CastPP nodes whose only purpose is to carry them. Do
2363   // that early so that optimizations are not disrupted by the extra
2364   // CastPP nodes.
2365   remove_speculative_types(igvn);
2366 
2367   if (failing())  return;
2368 
2369   // No more new expensive nodes will be added to the list from here
2370   // so keep only the actual candidates for optimizations.
2371   cleanup_expensive_nodes(igvn);
2372 
2373   if (failing())  return;
2374 
2375   assert(EnableVectorSupport || !has_vbox_nodes(), "sanity");
2376   if (EnableVectorSupport && has_vbox_nodes()) {
2377     TracePhase tp(_t_vector);
2378     PhaseVector pv(igvn);
2379     pv.optimize_vector_boxes();
2380     if (failing())  return;
2381     print_method(PHASE_ITER_GVN_AFTER_VECTOR, 2);
2382   }
2383   assert(!has_vbox_nodes(), "sanity");
2384 
2385   if (!failing() && RenumberLiveNodes && live_nodes() + NodeLimitFudgeFactor < unique()) {
2386     Compile::TracePhase tp(_t_renumberLive);
2387     igvn_worklist()->ensure_empty(); // should be done with igvn
2388     {
2389       ResourceMark rm;
2390       PhaseRenumberLive prl(initial_gvn(), *igvn_worklist());
2391     }
2392     igvn.reset();
2393     igvn.optimize();
2394     if (failing()) return;
2395   }
2396 
2397   // Now that all inlining is over and no PhaseRemoveUseless will run, cut edge from root to loop
2398   // safepoints
2399   remove_root_to_sfpts_edges(igvn);
2400 
2401   if (failing())  return;
2402 
2403   if (has_loops()) {
2404     print_method(PHASE_BEFORE_LOOP_OPTS, 2);
2405   }
2406 
2407   // Perform escape analysis
2408   if (do_escape_analysis() && ConnectionGraph::has_candidates(this)) {
2409     if (has_loops()) {
2410       // Cleanup graph (remove dead nodes).
2411       TracePhase tp(_t_idealLoop);
2412       PhaseIdealLoop::optimize(igvn, LoopOptsMaxUnroll);
2413       if (failing())  return;
2414     }
2415     bool progress;
2416     print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
2417     do {
2418       ConnectionGraph::do_analysis(this, &igvn);
2419 
2420       if (failing())  return;
2421 
2422       int mcount = macro_count(); // Record number of allocations and locks before IGVN
2423 
2424       // Optimize out fields loads from scalar replaceable allocations.
2425       igvn.optimize();
2426       print_method(PHASE_ITER_GVN_AFTER_EA, 2);
2427 
2428       if (failing()) return;
2429 
2430       if (congraph() != nullptr && macro_count() > 0) {
2431         TracePhase tp(_t_macroEliminate);
2432         PhaseMacroExpand mexp(igvn);
2433         mexp.eliminate_macro_nodes();
2434         if (failing()) return;
2435         print_method(PHASE_AFTER_MACRO_ELIMINATION, 2);
2436 
2437         igvn.set_delay_transform(false);
2438         igvn.optimize();
2439         if (failing()) return;
2440 
2441         print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
2442       }
2443 
2444       ConnectionGraph::verify_ram_nodes(this, root());
2445       if (failing())  return;
2446 
2447       progress = do_iterative_escape_analysis() &&
2448                  (macro_count() < mcount) &&
2449                  ConnectionGraph::has_candidates(this);
2450       // Try again if candidates exist and made progress
2451       // by removing some allocations and/or locks.
2452     } while (progress);
2453   }
2454 
2455   // Loop transforms on the ideal graph.  Range Check Elimination,
2456   // peeling, unrolling, etc.
2457 
2458   // Set loop opts counter
2459   if((_loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
2460     {
2461       TracePhase tp(_t_idealLoop);
2462       PhaseIdealLoop::optimize(igvn, LoopOptsDefault);
2463       _loop_opts_cnt--;
2464       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP1, 2);
2465       if (failing())  return;
2466     }
2467     // Loop opts pass if partial peeling occurred in previous pass
2468     if(PartialPeelLoop && major_progress() && (_loop_opts_cnt > 0)) {
2469       TracePhase tp(_t_idealLoop);
2470       PhaseIdealLoop::optimize(igvn, LoopOptsSkipSplitIf);
2471       _loop_opts_cnt--;
2472       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP2, 2);
2473       if (failing())  return;
2474     }
2475     // Loop opts pass for loop-unrolling before CCP
2476     if(major_progress() && (_loop_opts_cnt > 0)) {
2477       TracePhase tp(_t_idealLoop);
2478       PhaseIdealLoop::optimize(igvn, LoopOptsSkipSplitIf);
2479       _loop_opts_cnt--;
2480       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP3, 2);
2481     }
2482     if (!failing()) {
2483       // Verify that last round of loop opts produced a valid graph
2484       PhaseIdealLoop::verify(igvn);
2485     }
2486   }
2487   if (failing())  return;
2488 
2489   // Conditional Constant Propagation;
2490   print_method(PHASE_BEFORE_CCP1, 2);
2491   PhaseCCP ccp( &igvn );
2492   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
2493   {
2494     TracePhase tp(_t_ccp);
2495     ccp.do_transform();
2496   }
2497   print_method(PHASE_CCP1, 2);
2498 
2499   assert( true, "Break here to ccp.dump_old2new_map()");
2500 
2501   // Iterative Global Value Numbering, including ideal transforms
2502   {
2503     TracePhase tp(_t_iterGVN2);
2504     igvn.reset_from_igvn(&ccp);
2505     igvn.optimize();
2506   }
2507   print_method(PHASE_ITER_GVN2, 2);
2508 
2509   if (failing())  return;
2510 
2511   // Loop transforms on the ideal graph.  Range Check Elimination,
2512   // peeling, unrolling, etc.
2513   if (!optimize_loops(igvn, LoopOptsDefault)) {
2514     return;
2515   }
2516 
2517   if (failing())  return;
2518 
2519   C->clear_major_progress(); // ensure that major progress is now clear
2520 
2521   process_for_post_loop_opts_igvn(igvn);
2522 
2523   process_for_merge_stores_igvn(igvn);
2524 
2525   if (failing())  return;
2526 
2527 #ifdef ASSERT
2528   bs->verify_gc_barriers(this, BarrierSetC2::BeforeMacroExpand);
2529 #endif
2530 
2531   {
2532     TracePhase tp(_t_macroExpand);
2533     print_method(PHASE_BEFORE_MACRO_EXPANSION, 3);
2534     PhaseMacroExpand  mex(igvn);
2535     // Do not allow new macro nodes once we start to eliminate and expand
2536     C->reset_allow_macro_nodes();
2537     // Last attempt to eliminate macro nodes before expand
2538     mex.eliminate_macro_nodes();
2539     if (failing()) {
2540       return;
2541     }
2542     mex.eliminate_opaque_looplimit_macro_nodes();
2543     if (failing()) {
2544       return;
2545     }
2546     print_method(PHASE_AFTER_MACRO_ELIMINATION, 2);
2547     if (mex.expand_macro_nodes()) {
2548       assert(failing(), "must bail out w/ explicit message");
2549       return;
2550     }
2551     print_method(PHASE_AFTER_MACRO_EXPANSION, 2);
2552   }
2553 
2554   {
2555     TracePhase tp(_t_barrierExpand);
2556     if (bs->expand_barriers(this, igvn)) {
2557       assert(failing(), "must bail out w/ explicit message");
2558       return;
2559     }
2560     print_method(PHASE_BARRIER_EXPANSION, 2);
2561   }
2562 
2563   if (C->max_vector_size() > 0) {
2564     C->optimize_logic_cones(igvn);
2565     igvn.optimize();
2566     if (failing()) return;
2567   }
2568 
2569   DEBUG_ONLY( _modified_nodes = nullptr; )
2570 
2571   assert(igvn._worklist.size() == 0, "not empty");
2572 
2573   assert(_late_inlines.length() == 0 || IncrementalInlineMH || IncrementalInlineVirtual, "not empty");
2574 
2575   if (_late_inlines.length() > 0) {
2576     // More opportunities to optimize virtual and MH calls.
2577     // Though it's maybe too late to perform inlining, strength-reducing them to direct calls is still an option.
2578     process_late_inline_calls_no_inline(igvn);
2579     if (failing())  return;
2580   }
2581  } // (End scope of igvn; run destructor if necessary for asserts.)
2582 
2583  check_no_dead_use();
2584 
2585  // We will never use the NodeHash table any more. Clear it so that final_graph_reshaping does not have
2586  // to remove hashes to unlock nodes for modifications.
2587  C->node_hash()->clear();
2588 
2589  // A method with only infinite loops has no edges entering loops from root
2590  {
2591    TracePhase tp(_t_graphReshaping);
2592    if (final_graph_reshaping()) {
2593      assert(failing(), "must bail out w/ explicit message");
2594      return;
2595    }
2596  }
2597 
2598  print_method(PHASE_OPTIMIZE_FINISHED, 2);
2599  DEBUG_ONLY(set_phase_optimize_finished();)
2600 }
2601 
2602 #ifdef ASSERT
2603 void Compile::check_no_dead_use() const {
2604   ResourceMark rm;
2605   Unique_Node_List wq;
2606   wq.push(root());
2607   for (uint i = 0; i < wq.size(); ++i) {
2608     Node* n = wq.at(i);
2609     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
2610       Node* u = n->fast_out(j);
2611       if (u->outcnt() == 0 && !u->is_Con()) {
2612         u->dump();
2613         fatal("no reachable node should have no use");
2614       }
2615       wq.push(u);
2616     }
2617   }
2618 }
2619 #endif
2620 
2621 void Compile::inline_vector_reboxing_calls() {
2622   if (C->_vector_reboxing_late_inlines.length() > 0) {
2623     _late_inlines_pos = C->_late_inlines.length();
2624     while (_vector_reboxing_late_inlines.length() > 0) {
2625       CallGenerator* cg = _vector_reboxing_late_inlines.pop();
2626       cg->do_late_inline();
2627       if (failing())  return;
2628       print_method(PHASE_INLINE_VECTOR_REBOX, 3, cg->call_node());
2629     }
2630     _vector_reboxing_late_inlines.trunc_to(0);
2631   }
2632 }
2633 
2634 bool Compile::has_vbox_nodes() {
2635   if (C->_vector_reboxing_late_inlines.length() > 0) {
2636     return true;
2637   }
2638   for (int macro_idx = C->macro_count() - 1; macro_idx >= 0; macro_idx--) {
2639     Node * n = C->macro_node(macro_idx);
2640     assert(n->is_macro(), "only macro nodes expected here");
2641     if (n->Opcode() == Op_VectorUnbox || n->Opcode() == Op_VectorBox || n->Opcode() == Op_VectorBoxAllocate) {
2642       return true;
2643     }
2644   }
2645   return false;
2646 }
2647 
2648 //---------------------------- Bitwise operation packing optimization ---------------------------
2649 
2650 static bool is_vector_unary_bitwise_op(Node* n) {
2651   return n->Opcode() == Op_XorV &&
2652          VectorNode::is_vector_bitwise_not_pattern(n);
2653 }
2654 
2655 static bool is_vector_binary_bitwise_op(Node* n) {
2656   switch (n->Opcode()) {
2657     case Op_AndV:
2658     case Op_OrV:
2659       return true;
2660 
2661     case Op_XorV:
2662       return !is_vector_unary_bitwise_op(n);
2663 
2664     default:
2665       return false;
2666   }
2667 }
2668 
2669 static bool is_vector_ternary_bitwise_op(Node* n) {
2670   return n->Opcode() == Op_MacroLogicV;
2671 }
2672 
2673 static bool is_vector_bitwise_op(Node* n) {
2674   return is_vector_unary_bitwise_op(n)  ||
2675          is_vector_binary_bitwise_op(n) ||
2676          is_vector_ternary_bitwise_op(n);
2677 }
2678 
2679 static bool is_vector_bitwise_cone_root(Node* n) {
2680   if (n->bottom_type()->isa_vectmask() || !is_vector_bitwise_op(n)) {
2681     return false;
2682   }
2683   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2684     if (is_vector_bitwise_op(n->fast_out(i))) {
2685       return false;
2686     }
2687   }
2688   return true;
2689 }
2690 
2691 static uint collect_unique_inputs(Node* n, Unique_Node_List& inputs) {
2692   uint cnt = 0;
2693   if (is_vector_bitwise_op(n)) {
2694     uint inp_cnt = n->is_predicated_vector() ? n->req()-1 : n->req();
2695     if (VectorNode::is_vector_bitwise_not_pattern(n)) {
2696       for (uint i = 1; i < inp_cnt; i++) {
2697         Node* in = n->in(i);
2698         bool skip = VectorNode::is_all_ones_vector(in);
2699         if (!skip && !inputs.member(in)) {
2700           inputs.push(in);
2701           cnt++;
2702         }
2703       }
2704       assert(cnt <= 1, "not unary");
2705     } else {
2706       uint last_req = inp_cnt;
2707       if (is_vector_ternary_bitwise_op(n)) {
2708         last_req = inp_cnt - 1; // skip last input
2709       }
2710       for (uint i = 1; i < last_req; i++) {
2711         Node* def = n->in(i);
2712         if (!inputs.member(def)) {
2713           inputs.push(def);
2714           cnt++;
2715         }
2716       }
2717     }
2718   } else { // not a bitwise operations
2719     if (!inputs.member(n)) {
2720       inputs.push(n);
2721       cnt++;
2722     }
2723   }
2724   return cnt;
2725 }
2726 
2727 void Compile::collect_logic_cone_roots(Unique_Node_List& list) {
2728   Unique_Node_List useful_nodes;
2729   C->identify_useful_nodes(useful_nodes);
2730 
2731   for (uint i = 0; i < useful_nodes.size(); i++) {
2732     Node* n = useful_nodes.at(i);
2733     if (is_vector_bitwise_cone_root(n)) {
2734       list.push(n);
2735     }
2736   }
2737 }
2738 
2739 Node* Compile::xform_to_MacroLogicV(PhaseIterGVN& igvn,
2740                                     const TypeVect* vt,
2741                                     Unique_Node_List& partition,
2742                                     Unique_Node_List& inputs) {
2743   assert(partition.size() == 2 || partition.size() == 3, "not supported");
2744   assert(inputs.size()    == 2 || inputs.size()    == 3, "not supported");
2745   assert(Matcher::match_rule_supported_vector(Op_MacroLogicV, vt->length(), vt->element_basic_type()), "not supported");
2746 
2747   Node* in1 = inputs.at(0);
2748   Node* in2 = inputs.at(1);
2749   Node* in3 = (inputs.size() == 3 ? inputs.at(2) : in2);
2750 
2751   uint func = compute_truth_table(partition, inputs);
2752 
2753   Node* pn = partition.at(partition.size() - 1);
2754   Node* mask = pn->is_predicated_vector() ? pn->in(pn->req()-1) : nullptr;
2755   return igvn.transform(MacroLogicVNode::make(igvn, in1, in2, in3, mask, func, vt));
2756 }
2757 
2758 static uint extract_bit(uint func, uint pos) {
2759   return (func & (1 << pos)) >> pos;
2760 }
2761 
2762 //
2763 //  A macro logic node represents a truth table. It has 4 inputs,
2764 //  First three inputs corresponds to 3 columns of a truth table
2765 //  and fourth input captures the logic function.
2766 //
2767 //  eg.  fn = (in1 AND in2) OR in3;
2768 //
2769 //      MacroNode(in1,in2,in3,fn)
2770 //
2771 //  -----------------
2772 //  in1 in2 in3  fn
2773 //  -----------------
2774 //  0    0   0    0
2775 //  0    0   1    1
2776 //  0    1   0    0
2777 //  0    1   1    1
2778 //  1    0   0    0
2779 //  1    0   1    1
2780 //  1    1   0    1
2781 //  1    1   1    1
2782 //
2783 
2784 uint Compile::eval_macro_logic_op(uint func, uint in1 , uint in2, uint in3) {
2785   int res = 0;
2786   for (int i = 0; i < 8; i++) {
2787     int bit1 = extract_bit(in1, i);
2788     int bit2 = extract_bit(in2, i);
2789     int bit3 = extract_bit(in3, i);
2790 
2791     int func_bit_pos = (bit1 << 2 | bit2 << 1 | bit3);
2792     int func_bit = extract_bit(func, func_bit_pos);
2793 
2794     res |= func_bit << i;
2795   }
2796   return res;
2797 }
2798 
2799 static uint eval_operand(Node* n, HashTable<Node*,uint>& eval_map) {
2800   assert(n != nullptr, "");
2801   assert(eval_map.contains(n), "absent");
2802   return *(eval_map.get(n));
2803 }
2804 
2805 static void eval_operands(Node* n,
2806                           uint& func1, uint& func2, uint& func3,
2807                           HashTable<Node*,uint>& eval_map) {
2808   assert(is_vector_bitwise_op(n), "");
2809 
2810   if (is_vector_unary_bitwise_op(n)) {
2811     Node* opnd = n->in(1);
2812     if (VectorNode::is_vector_bitwise_not_pattern(n) && VectorNode::is_all_ones_vector(opnd)) {
2813       opnd = n->in(2);
2814     }
2815     func1 = eval_operand(opnd, eval_map);
2816   } else if (is_vector_binary_bitwise_op(n)) {
2817     func1 = eval_operand(n->in(1), eval_map);
2818     func2 = eval_operand(n->in(2), eval_map);
2819   } else {
2820     assert(is_vector_ternary_bitwise_op(n), "unknown operation");
2821     func1 = eval_operand(n->in(1), eval_map);
2822     func2 = eval_operand(n->in(2), eval_map);
2823     func3 = eval_operand(n->in(3), eval_map);
2824   }
2825 }
2826 
2827 uint Compile::compute_truth_table(Unique_Node_List& partition, Unique_Node_List& inputs) {
2828   assert(inputs.size() <= 3, "sanity");
2829   ResourceMark rm;
2830   uint res = 0;
2831   HashTable<Node*,uint> eval_map;
2832 
2833   // Populate precomputed functions for inputs.
2834   // Each input corresponds to one column of 3 input truth-table.
2835   uint input_funcs[] = { 0xAA,   // (_, _, c) -> c
2836                          0xCC,   // (_, b, _) -> b
2837                          0xF0 }; // (a, _, _) -> a
2838   for (uint i = 0; i < inputs.size(); i++) {
2839     eval_map.put(inputs.at(i), input_funcs[2-i]);
2840   }
2841 
2842   for (uint i = 0; i < partition.size(); i++) {
2843     Node* n = partition.at(i);
2844 
2845     uint func1 = 0, func2 = 0, func3 = 0;
2846     eval_operands(n, func1, func2, func3, eval_map);
2847 
2848     switch (n->Opcode()) {
2849       case Op_OrV:
2850         assert(func3 == 0, "not binary");
2851         res = func1 | func2;
2852         break;
2853       case Op_AndV:
2854         assert(func3 == 0, "not binary");
2855         res = func1 & func2;
2856         break;
2857       case Op_XorV:
2858         if (VectorNode::is_vector_bitwise_not_pattern(n)) {
2859           assert(func2 == 0 && func3 == 0, "not unary");
2860           res = (~func1) & 0xFF;
2861         } else {
2862           assert(func3 == 0, "not binary");
2863           res = func1 ^ func2;
2864         }
2865         break;
2866       case Op_MacroLogicV:
2867         // Ordering of inputs may change during evaluation of sub-tree
2868         // containing MacroLogic node as a child node, thus a re-evaluation
2869         // makes sure that function is evaluated in context of current
2870         // inputs.
2871         res = eval_macro_logic_op(n->in(4)->get_int(), func1, func2, func3);
2872         break;
2873 
2874       default: assert(false, "not supported: %s", n->Name());
2875     }
2876     assert(res <= 0xFF, "invalid");
2877     eval_map.put(n, res);
2878   }
2879   return res;
2880 }
2881 
2882 // Criteria under which nodes gets packed into a macro logic node:-
2883 //  1) Parent and both child nodes are all unmasked or masked with
2884 //     same predicates.
2885 //  2) Masked parent can be packed with left child if it is predicated
2886 //     and both have same predicates.
2887 //  3) Masked parent can be packed with right child if its un-predicated
2888 //     or has matching predication condition.
2889 //  4) An unmasked parent can be packed with an unmasked child.
2890 bool Compile::compute_logic_cone(Node* n, Unique_Node_List& partition, Unique_Node_List& inputs) {
2891   assert(partition.size() == 0, "not empty");
2892   assert(inputs.size() == 0, "not empty");
2893   if (is_vector_ternary_bitwise_op(n)) {
2894     return false;
2895   }
2896 
2897   bool is_unary_op = is_vector_unary_bitwise_op(n);
2898   if (is_unary_op) {
2899     assert(collect_unique_inputs(n, inputs) == 1, "not unary");
2900     return false; // too few inputs
2901   }
2902 
2903   bool pack_left_child = true;
2904   bool pack_right_child = true;
2905 
2906   bool left_child_LOP = is_vector_bitwise_op(n->in(1));
2907   bool right_child_LOP = is_vector_bitwise_op(n->in(2));
2908 
2909   int left_child_input_cnt = 0;
2910   int right_child_input_cnt = 0;
2911 
2912   bool parent_is_predicated = n->is_predicated_vector();
2913   bool left_child_predicated = n->in(1)->is_predicated_vector();
2914   bool right_child_predicated = n->in(2)->is_predicated_vector();
2915 
2916   Node* parent_pred = parent_is_predicated ? n->in(n->req()-1) : nullptr;
2917   Node* left_child_pred = left_child_predicated ? n->in(1)->in(n->in(1)->req()-1) : nullptr;
2918   Node* right_child_pred = right_child_predicated ? n->in(1)->in(n->in(1)->req()-1) : nullptr;
2919 
2920   do {
2921     if (pack_left_child && left_child_LOP &&
2922         ((!parent_is_predicated && !left_child_predicated) ||
2923         ((parent_is_predicated && left_child_predicated &&
2924           parent_pred == left_child_pred)))) {
2925        partition.push(n->in(1));
2926        left_child_input_cnt = collect_unique_inputs(n->in(1), inputs);
2927     } else {
2928        inputs.push(n->in(1));
2929        left_child_input_cnt = 1;
2930     }
2931 
2932     if (pack_right_child && right_child_LOP &&
2933         (!right_child_predicated ||
2934          (right_child_predicated && parent_is_predicated &&
2935           parent_pred == right_child_pred))) {
2936        partition.push(n->in(2));
2937        right_child_input_cnt = collect_unique_inputs(n->in(2), inputs);
2938     } else {
2939        inputs.push(n->in(2));
2940        right_child_input_cnt = 1;
2941     }
2942 
2943     if (inputs.size() > 3) {
2944       assert(partition.size() > 0, "");
2945       inputs.clear();
2946       partition.clear();
2947       if (left_child_input_cnt > right_child_input_cnt) {
2948         pack_left_child = false;
2949       } else {
2950         pack_right_child = false;
2951       }
2952     } else {
2953       break;
2954     }
2955   } while(true);
2956 
2957   if(partition.size()) {
2958     partition.push(n);
2959   }
2960 
2961   return (partition.size() == 2 || partition.size() == 3) &&
2962          (inputs.size()    == 2 || inputs.size()    == 3);
2963 }
2964 
2965 void Compile::process_logic_cone_root(PhaseIterGVN &igvn, Node *n, VectorSet &visited) {
2966   assert(is_vector_bitwise_op(n), "not a root");
2967 
2968   visited.set(n->_idx);
2969 
2970   // 1) Do a DFS walk over the logic cone.
2971   for (uint i = 1; i < n->req(); i++) {
2972     Node* in = n->in(i);
2973     if (!visited.test(in->_idx) && is_vector_bitwise_op(in)) {
2974       process_logic_cone_root(igvn, in, visited);
2975     }
2976   }
2977 
2978   // 2) Bottom up traversal: Merge node[s] with
2979   // the parent to form macro logic node.
2980   Unique_Node_List partition;
2981   Unique_Node_List inputs;
2982   if (compute_logic_cone(n, partition, inputs)) {
2983     const TypeVect* vt = n->bottom_type()->is_vect();
2984     Node* pn = partition.at(partition.size() - 1);
2985     Node* mask = pn->is_predicated_vector() ? pn->in(pn->req()-1) : nullptr;
2986     if (mask == nullptr ||
2987         Matcher::match_rule_supported_vector_masked(Op_MacroLogicV, vt->length(), vt->element_basic_type())) {
2988       Node* macro_logic = xform_to_MacroLogicV(igvn, vt, partition, inputs);
2989       VectorNode::trace_new_vector(macro_logic, "MacroLogic");
2990       igvn.replace_node(n, macro_logic);
2991     }
2992   }
2993 }
2994 
2995 void Compile::optimize_logic_cones(PhaseIterGVN &igvn) {
2996   ResourceMark rm;
2997   if (Matcher::match_rule_supported(Op_MacroLogicV)) {
2998     Unique_Node_List list;
2999     collect_logic_cone_roots(list);
3000 
3001     while (list.size() > 0) {
3002       Node* n = list.pop();
3003       const TypeVect* vt = n->bottom_type()->is_vect();
3004       bool supported = Matcher::match_rule_supported_vector(Op_MacroLogicV, vt->length(), vt->element_basic_type());
3005       if (supported) {
3006         VectorSet visited(comp_arena());
3007         process_logic_cone_root(igvn, n, visited);
3008       }
3009     }
3010   }
3011 }
3012 
3013 //------------------------------Code_Gen---------------------------------------
3014 // Given a graph, generate code for it
3015 void Compile::Code_Gen() {
3016   if (failing()) {
3017     return;
3018   }
3019 
3020   // Perform instruction selection.  You might think we could reclaim Matcher
3021   // memory PDQ, but actually the Matcher is used in generating spill code.
3022   // Internals of the Matcher (including some VectorSets) must remain live
3023   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
3024   // set a bit in reclaimed memory.
3025 
3026   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
3027   // nodes.  Mapping is only valid at the root of each matched subtree.
3028   NOT_PRODUCT( verify_graph_edges(); )
3029 
3030   Matcher matcher;
3031   _matcher = &matcher;
3032   {
3033     TracePhase tp(_t_matcher);
3034     matcher.match();
3035     if (failing()) {
3036       return;
3037     }
3038   }
3039   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
3040   // nodes.  Mapping is only valid at the root of each matched subtree.
3041   NOT_PRODUCT( verify_graph_edges(); )
3042 
3043   // If you have too many nodes, or if matching has failed, bail out
3044   check_node_count(0, "out of nodes matching instructions");
3045   if (failing()) {
3046     return;
3047   }
3048 
3049   print_method(PHASE_MATCHING, 2);
3050 
3051   // Build a proper-looking CFG
3052   PhaseCFG cfg(node_arena(), root(), matcher);
3053   if (failing()) {
3054     return;
3055   }
3056   _cfg = &cfg;
3057   {
3058     TracePhase tp(_t_scheduler);
3059     bool success = cfg.do_global_code_motion();
3060     if (!success) {
3061       return;
3062     }
3063 
3064     print_method(PHASE_GLOBAL_CODE_MOTION, 2);
3065     NOT_PRODUCT( verify_graph_edges(); )
3066     cfg.verify();
3067     if (failing()) {
3068       return;
3069     }
3070   }
3071 
3072   PhaseChaitin regalloc(unique(), cfg, matcher, false);
3073   _regalloc = &regalloc;
3074   {
3075     TracePhase tp(_t_registerAllocation);
3076     // Perform register allocation.  After Chaitin, use-def chains are
3077     // no longer accurate (at spill code) and so must be ignored.
3078     // Node->LRG->reg mappings are still accurate.
3079     _regalloc->Register_Allocate();
3080 
3081     // Bail out if the allocator builds too many nodes
3082     if (failing()) {
3083       return;
3084     }
3085 
3086     print_method(PHASE_REGISTER_ALLOCATION, 2);
3087   }
3088 
3089   // Prior to register allocation we kept empty basic blocks in case the
3090   // the allocator needed a place to spill.  After register allocation we
3091   // are not adding any new instructions.  If any basic block is empty, we
3092   // can now safely remove it.
3093   {
3094     TracePhase tp(_t_blockOrdering);
3095     cfg.remove_empty_blocks();
3096     if (do_freq_based_layout()) {
3097       PhaseBlockLayout layout(cfg);
3098     } else {
3099       cfg.set_loop_alignment();
3100     }
3101     cfg.fixup_flow();
3102     cfg.remove_unreachable_blocks();
3103     cfg.verify_dominator_tree();
3104     print_method(PHASE_BLOCK_ORDERING, 3);
3105   }
3106 
3107   // Apply peephole optimizations
3108   if( OptoPeephole ) {
3109     TracePhase tp(_t_peephole);
3110     PhasePeephole peep( _regalloc, cfg);
3111     peep.do_transform();
3112     print_method(PHASE_PEEPHOLE, 3);
3113   }
3114 
3115   // Do late expand if CPU requires this.
3116   if (Matcher::require_postalloc_expand) {
3117     TracePhase tp(_t_postalloc_expand);
3118     cfg.postalloc_expand(_regalloc);
3119     print_method(PHASE_POSTALLOC_EXPAND, 3);
3120   }
3121 
3122 #ifdef ASSERT
3123   {
3124     CompilationMemoryStatistic::do_test_allocations();
3125     if (failing()) return;
3126   }
3127 #endif
3128 
3129   // Convert Nodes to instruction bits in a buffer
3130   {
3131     TracePhase tp(_t_output);
3132     PhaseOutput output;
3133     output.Output();
3134     if (failing())  return;
3135     output.install();
3136     print_method(PHASE_FINAL_CODE, 1); // Compile::_output is not null here
3137   }
3138 
3139   // He's dead, Jim.
3140   _cfg     = (PhaseCFG*)((intptr_t)0xdeadbeef);
3141   _regalloc = (PhaseChaitin*)((intptr_t)0xdeadbeef);
3142 }
3143 
3144 //------------------------------Final_Reshape_Counts---------------------------
3145 // This class defines counters to help identify when a method
3146 // may/must be executed using hardware with only 24-bit precision.
3147 struct Final_Reshape_Counts : public StackObj {
3148   int  _call_count;             // count non-inlined 'common' calls
3149   int  _float_count;            // count float ops requiring 24-bit precision
3150   int  _double_count;           // count double ops requiring more precision
3151   int  _java_call_count;        // count non-inlined 'java' calls
3152   int  _inner_loop_count;       // count loops which need alignment
3153   VectorSet _visited;           // Visitation flags
3154   Node_List _tests;             // Set of IfNodes & PCTableNodes
3155 
3156   Final_Reshape_Counts() :
3157     _call_count(0), _float_count(0), _double_count(0),
3158     _java_call_count(0), _inner_loop_count(0) { }
3159 
3160   void inc_call_count  () { _call_count  ++; }
3161   void inc_float_count () { _float_count ++; }
3162   void inc_double_count() { _double_count++; }
3163   void inc_java_call_count() { _java_call_count++; }
3164   void inc_inner_loop_count() { _inner_loop_count++; }
3165 
3166   int  get_call_count  () const { return _call_count  ; }
3167   int  get_float_count () const { return _float_count ; }
3168   int  get_double_count() const { return _double_count; }
3169   int  get_java_call_count() const { return _java_call_count; }
3170   int  get_inner_loop_count() const { return _inner_loop_count; }
3171 };
3172 
3173 //------------------------------final_graph_reshaping_impl----------------------
3174 // Implement items 1-5 from final_graph_reshaping below.
3175 void Compile::final_graph_reshaping_impl(Node *n, Final_Reshape_Counts& frc, Unique_Node_List& dead_nodes) {
3176 
3177   if ( n->outcnt() == 0 ) return; // dead node
3178   uint nop = n->Opcode();
3179 
3180   // Check for 2-input instruction with "last use" on right input.
3181   // Swap to left input.  Implements item (2).
3182   if( n->req() == 3 &&          // two-input instruction
3183       n->in(1)->outcnt() > 1 && // left use is NOT a last use
3184       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
3185       n->in(2)->outcnt() == 1 &&// right use IS a last use
3186       !n->in(2)->is_Con() ) {   // right use is not a constant
3187     // Check for commutative opcode
3188     switch( nop ) {
3189     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddL:
3190     case Op_MaxI:  case Op_MaxL:  case Op_MaxF:  case Op_MaxD:
3191     case Op_MinI:  case Op_MinL:  case Op_MinF:  case Op_MinD:
3192     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulL:
3193     case Op_AndL:  case Op_XorL:  case Op_OrL:
3194     case Op_AndI:  case Op_XorI:  case Op_OrI: {
3195       // Move "last use" input to left by swapping inputs
3196       n->swap_edges(1, 2);
3197       break;
3198     }
3199     default:
3200       break;
3201     }
3202   }
3203 
3204 #ifdef ASSERT
3205   if( n->is_Mem() ) {
3206     int alias_idx = get_alias_index(n->as_Mem()->adr_type());
3207     assert( n->in(0) != nullptr || alias_idx != Compile::AliasIdxRaw ||
3208             // oop will be recorded in oop map if load crosses safepoint
3209             (n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
3210                               LoadNode::is_immutable_value(n->in(MemNode::Address)))),
3211             "raw memory operations should have control edge");
3212   }
3213   if (n->is_MemBar()) {
3214     MemBarNode* mb = n->as_MemBar();
3215     if (mb->trailing_store() || mb->trailing_load_store()) {
3216       assert(mb->leading_membar()->trailing_membar() == mb, "bad membar pair");
3217       Node* mem = mb->in(MemBarNode::Precedent);
3218       assert((mb->trailing_store() && mem->is_Store() && mem->as_Store()->is_release()) ||
3219              (mb->trailing_load_store() && mem->is_LoadStore()), "missing mem op");
3220     } else if (mb->leading()) {
3221       assert(mb->trailing_membar()->leading_membar() == mb, "bad membar pair");
3222     }
3223   }
3224 #endif
3225   // Count FPU ops and common calls, implements item (3)
3226   final_graph_reshaping_main_switch(n, frc, nop, dead_nodes);
3227 
3228   // Collect CFG split points
3229   if (n->is_MultiBranch() && !n->is_RangeCheck()) {
3230     frc._tests.push(n);
3231   }
3232 }
3233 
3234 void Compile::handle_div_mod_op(Node* n, BasicType bt, bool is_unsigned) {
3235   if (!UseDivMod) {
3236     return;
3237   }
3238 
3239   // Check if "a % b" and "a / b" both exist
3240   Node* d = n->find_similar(Op_DivIL(bt, is_unsigned));
3241   if (d == nullptr) {
3242     return;
3243   }
3244 
3245   // Replace them with a fused divmod if supported
3246   if (Matcher::has_match_rule(Op_DivModIL(bt, is_unsigned))) {
3247     DivModNode* divmod = DivModNode::make(n, bt, is_unsigned);
3248     // If the divisor input for a Div (or Mod etc.) is not zero, then the control input of the Div is set to zero.
3249     // It could be that the divisor input is found not zero because its type is narrowed down by a CastII in the
3250     // subgraph for that input. Range check CastIIs are removed during final graph reshape. To preserve the dependency
3251     // carried by a CastII, precedence edges are added to the Div node. We need to transfer the precedence edges to the
3252     // DivMod node so the dependency is not lost.
3253     divmod->add_prec_from(n);
3254     divmod->add_prec_from(d);
3255     d->subsume_by(divmod->div_proj(), this);
3256     n->subsume_by(divmod->mod_proj(), this);
3257   } else {
3258     // Replace "a % b" with "a - ((a / b) * b)"
3259     Node* mult = MulNode::make(d, d->in(2), bt);
3260     Node* sub = SubNode::make(d->in(1), mult, bt);
3261     n->subsume_by(sub, this);
3262   }
3263 }
3264 
3265 void Compile::final_graph_reshaping_main_switch(Node* n, Final_Reshape_Counts& frc, uint nop, Unique_Node_List& dead_nodes) {
3266   switch( nop ) {
3267   // Count all float operations that may use FPU
3268   case Op_AddF:
3269   case Op_SubF:
3270   case Op_MulF:
3271   case Op_DivF:
3272   case Op_NegF:
3273   case Op_ModF:
3274   case Op_ConvI2F:
3275   case Op_ConF:
3276   case Op_CmpF:
3277   case Op_CmpF3:
3278   case Op_StoreF:
3279   case Op_LoadF:
3280   // case Op_ConvL2F: // longs are split into 32-bit halves
3281     frc.inc_float_count();
3282     break;
3283 
3284   case Op_ConvF2D:
3285   case Op_ConvD2F:
3286     frc.inc_float_count();
3287     frc.inc_double_count();
3288     break;
3289 
3290   // Count all double operations that may use FPU
3291   case Op_AddD:
3292   case Op_SubD:
3293   case Op_MulD:
3294   case Op_DivD:
3295   case Op_NegD:
3296   case Op_ModD:
3297   case Op_ConvI2D:
3298   case Op_ConvD2I:
3299   // case Op_ConvL2D: // handled by leaf call
3300   // case Op_ConvD2L: // handled by leaf call
3301   case Op_ConD:
3302   case Op_CmpD:
3303   case Op_CmpD3:
3304   case Op_StoreD:
3305   case Op_LoadD:
3306   case Op_LoadD_unaligned:
3307     frc.inc_double_count();
3308     break;
3309   case Op_Opaque1:              // Remove Opaque Nodes before matching
3310     n->subsume_by(n->in(1), this);
3311     break;
3312   case Op_CallLeafPure: {
3313     // If the pure call is not supported, then lower to a CallLeaf.
3314     if (!Matcher::match_rule_supported(Op_CallLeafPure)) {
3315       CallNode* call = n->as_Call();
3316       CallNode* new_call = new CallLeafNode(call->tf(), call->entry_point(),
3317                                             call->_name, TypeRawPtr::BOTTOM);
3318       new_call->init_req(TypeFunc::Control, call->in(TypeFunc::Control));
3319       new_call->init_req(TypeFunc::I_O, C->top());
3320       new_call->init_req(TypeFunc::Memory, C->top());
3321       new_call->init_req(TypeFunc::ReturnAdr, C->top());
3322       new_call->init_req(TypeFunc::FramePtr, C->top());
3323       for (unsigned int i = TypeFunc::Parms; i < call->tf()->domain()->cnt(); i++) {
3324         new_call->init_req(i, call->in(i));
3325       }
3326       n->subsume_by(new_call, this);
3327     }
3328     frc.inc_call_count();
3329     break;
3330   }
3331   case Op_CallStaticJava:
3332   case Op_CallJava:
3333   case Op_CallDynamicJava:
3334     frc.inc_java_call_count(); // Count java call site;
3335   case Op_CallRuntime:
3336   case Op_CallLeaf:
3337   case Op_CallLeafVector:
3338   case Op_CallLeafNoFP: {
3339     assert (n->is_Call(), "");
3340     CallNode *call = n->as_Call();
3341     // Count call sites where the FP mode bit would have to be flipped.
3342     // Do not count uncommon runtime calls:
3343     // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
3344     // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
3345     if (!call->is_CallStaticJava() || !call->as_CallStaticJava()->_name) {
3346       frc.inc_call_count();   // Count the call site
3347     } else {                  // See if uncommon argument is shared
3348       Node *n = call->in(TypeFunc::Parms);
3349       int nop = n->Opcode();
3350       // Clone shared simple arguments to uncommon calls, item (1).
3351       if (n->outcnt() > 1 &&
3352           !n->is_Proj() &&
3353           nop != Op_CreateEx &&
3354           nop != Op_CheckCastPP &&
3355           nop != Op_DecodeN &&
3356           nop != Op_DecodeNKlass &&
3357           !n->is_Mem() &&
3358           !n->is_Phi()) {
3359         Node *x = n->clone();
3360         call->set_req(TypeFunc::Parms, x);
3361       }
3362     }
3363     break;
3364   }
3365   case Op_StoreB:
3366   case Op_StoreC:
3367   case Op_StoreI:
3368   case Op_StoreL:
3369   case Op_CompareAndSwapB:
3370   case Op_CompareAndSwapS:
3371   case Op_CompareAndSwapI:
3372   case Op_CompareAndSwapL:
3373   case Op_CompareAndSwapP:
3374   case Op_CompareAndSwapN:
3375   case Op_WeakCompareAndSwapB:
3376   case Op_WeakCompareAndSwapS:
3377   case Op_WeakCompareAndSwapI:
3378   case Op_WeakCompareAndSwapL:
3379   case Op_WeakCompareAndSwapP:
3380   case Op_WeakCompareAndSwapN:
3381   case Op_CompareAndExchangeB:
3382   case Op_CompareAndExchangeS:
3383   case Op_CompareAndExchangeI:
3384   case Op_CompareAndExchangeL:
3385   case Op_CompareAndExchangeP:
3386   case Op_CompareAndExchangeN:
3387   case Op_GetAndAddS:
3388   case Op_GetAndAddB:
3389   case Op_GetAndAddI:
3390   case Op_GetAndAddL:
3391   case Op_GetAndSetS:
3392   case Op_GetAndSetB:
3393   case Op_GetAndSetI:
3394   case Op_GetAndSetL:
3395   case Op_GetAndSetP:
3396   case Op_GetAndSetN:
3397   case Op_StoreP:
3398   case Op_StoreN:
3399   case Op_StoreNKlass:
3400   case Op_LoadB:
3401   case Op_LoadUB:
3402   case Op_LoadUS:
3403   case Op_LoadI:
3404   case Op_LoadKlass:
3405   case Op_LoadNKlass:
3406   case Op_LoadL:
3407   case Op_LoadL_unaligned:
3408   case Op_LoadP:
3409   case Op_LoadN:
3410   case Op_LoadRange:
3411   case Op_LoadS:
3412     break;
3413 
3414   case Op_AddP: {               // Assert sane base pointers
3415     Node *addp = n->in(AddPNode::Address);
3416     assert(n->as_AddP()->address_input_has_same_base(), "Base pointers must match (addp %u)", addp->_idx );
3417 #ifdef _LP64
3418     if ((UseCompressedOops || UseCompressedClassPointers) &&
3419         addp->Opcode() == Op_ConP &&
3420         addp == n->in(AddPNode::Base) &&
3421         n->in(AddPNode::Offset)->is_Con()) {
3422       // If the transformation of ConP to ConN+DecodeN is beneficial depends
3423       // on the platform and on the compressed oops mode.
3424       // Use addressing with narrow klass to load with offset on x86.
3425       // Some platforms can use the constant pool to load ConP.
3426       // Do this transformation here since IGVN will convert ConN back to ConP.
3427       const Type* t = addp->bottom_type();
3428       bool is_oop   = t->isa_oopptr() != nullptr;
3429       bool is_klass = t->isa_klassptr() != nullptr;
3430 
3431       if ((is_oop   && UseCompressedOops          && Matcher::const_oop_prefer_decode()  ) ||
3432           (is_klass && UseCompressedClassPointers && Matcher::const_klass_prefer_decode() &&
3433            t->isa_klassptr()->exact_klass()->is_in_encoding_range())) {
3434         Node* nn = nullptr;
3435 
3436         int op = is_oop ? Op_ConN : Op_ConNKlass;
3437 
3438         // Look for existing ConN node of the same exact type.
3439         Node* r  = root();
3440         uint cnt = r->outcnt();
3441         for (uint i = 0; i < cnt; i++) {
3442           Node* m = r->raw_out(i);
3443           if (m!= nullptr && m->Opcode() == op &&
3444               m->bottom_type()->make_ptr() == t) {
3445             nn = m;
3446             break;
3447           }
3448         }
3449         if (nn != nullptr) {
3450           // Decode a narrow oop to match address
3451           // [R12 + narrow_oop_reg<<3 + offset]
3452           if (is_oop) {
3453             nn = new DecodeNNode(nn, t);
3454           } else {
3455             nn = new DecodeNKlassNode(nn, t);
3456           }
3457           // Check for succeeding AddP which uses the same Base.
3458           // Otherwise we will run into the assertion above when visiting that guy.
3459           for (uint i = 0; i < n->outcnt(); ++i) {
3460             Node *out_i = n->raw_out(i);
3461             if (out_i && out_i->is_AddP() && out_i->in(AddPNode::Base) == addp) {
3462               out_i->set_req(AddPNode::Base, nn);
3463 #ifdef ASSERT
3464               for (uint j = 0; j < out_i->outcnt(); ++j) {
3465                 Node *out_j = out_i->raw_out(j);
3466                 assert(out_j == nullptr || !out_j->is_AddP() || out_j->in(AddPNode::Base) != addp,
3467                        "more than 2 AddP nodes in a chain (out_j %u)", out_j->_idx);
3468               }
3469 #endif
3470             }
3471           }
3472           n->set_req(AddPNode::Base, nn);
3473           n->set_req(AddPNode::Address, nn);
3474           if (addp->outcnt() == 0) {
3475             addp->disconnect_inputs(this);
3476           }
3477         }
3478       }
3479     }
3480 #endif
3481     break;
3482   }
3483 
3484   case Op_CastPP: {
3485     // Remove CastPP nodes to gain more freedom during scheduling but
3486     // keep the dependency they encode as control or precedence edges
3487     // (if control is set already) on memory operations. Some CastPP
3488     // nodes don't have a control (don't carry a dependency): skip
3489     // those.
3490     if (n->in(0) != nullptr) {
3491       ResourceMark rm;
3492       Unique_Node_List wq;
3493       wq.push(n);
3494       for (uint next = 0; next < wq.size(); ++next) {
3495         Node *m = wq.at(next);
3496         for (DUIterator_Fast imax, i = m->fast_outs(imax); i < imax; i++) {
3497           Node* use = m->fast_out(i);
3498           if (use->is_Mem() || use->is_EncodeNarrowPtr()) {
3499             use->ensure_control_or_add_prec(n->in(0));
3500           } else {
3501             switch(use->Opcode()) {
3502             case Op_AddP:
3503             case Op_DecodeN:
3504             case Op_DecodeNKlass:
3505             case Op_CheckCastPP:
3506             case Op_CastPP:
3507               wq.push(use);
3508               break;
3509             }
3510           }
3511         }
3512       }
3513     }
3514     const bool is_LP64 = LP64_ONLY(true) NOT_LP64(false);
3515     if (is_LP64 && n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
3516       Node* in1 = n->in(1);
3517       const Type* t = n->bottom_type();
3518       Node* new_in1 = in1->clone();
3519       new_in1->as_DecodeN()->set_type(t);
3520 
3521       if (!Matcher::narrow_oop_use_complex_address()) {
3522         //
3523         // x86, ARM and friends can handle 2 adds in addressing mode
3524         // and Matcher can fold a DecodeN node into address by using
3525         // a narrow oop directly and do implicit null check in address:
3526         //
3527         // [R12 + narrow_oop_reg<<3 + offset]
3528         // NullCheck narrow_oop_reg
3529         //
3530         // On other platforms (Sparc) we have to keep new DecodeN node and
3531         // use it to do implicit null check in address:
3532         //
3533         // decode_not_null narrow_oop_reg, base_reg
3534         // [base_reg + offset]
3535         // NullCheck base_reg
3536         //
3537         // Pin the new DecodeN node to non-null path on these platform (Sparc)
3538         // to keep the information to which null check the new DecodeN node
3539         // corresponds to use it as value in implicit_null_check().
3540         //
3541         new_in1->set_req(0, n->in(0));
3542       }
3543 
3544       n->subsume_by(new_in1, this);
3545       if (in1->outcnt() == 0) {
3546         in1->disconnect_inputs(this);
3547       }
3548     } else {
3549       n->subsume_by(n->in(1), this);
3550       if (n->outcnt() == 0) {
3551         n->disconnect_inputs(this);
3552       }
3553     }
3554     break;
3555   }
3556   case Op_CastII: {
3557     n->as_CastII()->remove_range_check_cast(this);
3558     break;
3559   }
3560 #ifdef _LP64
3561   case Op_CmpP:
3562     // Do this transformation here to preserve CmpPNode::sub() and
3563     // other TypePtr related Ideal optimizations (for example, ptr nullness).
3564     if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
3565       Node* in1 = n->in(1);
3566       Node* in2 = n->in(2);
3567       if (!in1->is_DecodeNarrowPtr()) {
3568         in2 = in1;
3569         in1 = n->in(2);
3570       }
3571       assert(in1->is_DecodeNarrowPtr(), "sanity");
3572 
3573       Node* new_in2 = nullptr;
3574       if (in2->is_DecodeNarrowPtr()) {
3575         assert(in2->Opcode() == in1->Opcode(), "must be same node type");
3576         new_in2 = in2->in(1);
3577       } else if (in2->Opcode() == Op_ConP) {
3578         const Type* t = in2->bottom_type();
3579         if (t == TypePtr::NULL_PTR) {
3580           assert(in1->is_DecodeN(), "compare klass to null?");
3581           // Don't convert CmpP null check into CmpN if compressed
3582           // oops implicit null check is not generated.
3583           // This will allow to generate normal oop implicit null check.
3584           if (Matcher::gen_narrow_oop_implicit_null_checks())
3585             new_in2 = ConNode::make(TypeNarrowOop::NULL_PTR);
3586           //
3587           // This transformation together with CastPP transformation above
3588           // will generated code for implicit null checks for compressed oops.
3589           //
3590           // The original code after Optimize()
3591           //
3592           //    LoadN memory, narrow_oop_reg
3593           //    decode narrow_oop_reg, base_reg
3594           //    CmpP base_reg, nullptr
3595           //    CastPP base_reg // NotNull
3596           //    Load [base_reg + offset], val_reg
3597           //
3598           // after these transformations will be
3599           //
3600           //    LoadN memory, narrow_oop_reg
3601           //    CmpN narrow_oop_reg, nullptr
3602           //    decode_not_null narrow_oop_reg, base_reg
3603           //    Load [base_reg + offset], val_reg
3604           //
3605           // and the uncommon path (== nullptr) will use narrow_oop_reg directly
3606           // since narrow oops can be used in debug info now (see the code in
3607           // final_graph_reshaping_walk()).
3608           //
3609           // At the end the code will be matched to
3610           // on x86:
3611           //
3612           //    Load_narrow_oop memory, narrow_oop_reg
3613           //    Load [R12 + narrow_oop_reg<<3 + offset], val_reg
3614           //    NullCheck narrow_oop_reg
3615           //
3616           // and on sparc:
3617           //
3618           //    Load_narrow_oop memory, narrow_oop_reg
3619           //    decode_not_null narrow_oop_reg, base_reg
3620           //    Load [base_reg + offset], val_reg
3621           //    NullCheck base_reg
3622           //
3623         } else if (t->isa_oopptr()) {
3624           new_in2 = ConNode::make(t->make_narrowoop());
3625         } else if (t->isa_klassptr()) {
3626           ciKlass* klass = t->is_klassptr()->exact_klass();
3627           if (klass->is_in_encoding_range()) {
3628             new_in2 = ConNode::make(t->make_narrowklass());
3629           }
3630         }
3631       }
3632       if (new_in2 != nullptr) {
3633         Node* cmpN = new CmpNNode(in1->in(1), new_in2);
3634         n->subsume_by(cmpN, this);
3635         if (in1->outcnt() == 0) {
3636           in1->disconnect_inputs(this);
3637         }
3638         if (in2->outcnt() == 0) {
3639           in2->disconnect_inputs(this);
3640         }
3641       }
3642     }
3643     break;
3644 
3645   case Op_DecodeN:
3646   case Op_DecodeNKlass:
3647     assert(!n->in(1)->is_EncodeNarrowPtr(), "should be optimized out");
3648     // DecodeN could be pinned when it can't be fold into
3649     // an address expression, see the code for Op_CastPP above.
3650     assert(n->in(0) == nullptr || (UseCompressedOops && !Matcher::narrow_oop_use_complex_address()), "no control");
3651     break;
3652 
3653   case Op_EncodeP:
3654   case Op_EncodePKlass: {
3655     Node* in1 = n->in(1);
3656     if (in1->is_DecodeNarrowPtr()) {
3657       n->subsume_by(in1->in(1), this);
3658     } else if (in1->Opcode() == Op_ConP) {
3659       const Type* t = in1->bottom_type();
3660       if (t == TypePtr::NULL_PTR) {
3661         assert(t->isa_oopptr(), "null klass?");
3662         n->subsume_by(ConNode::make(TypeNarrowOop::NULL_PTR), this);
3663       } else if (t->isa_oopptr()) {
3664         n->subsume_by(ConNode::make(t->make_narrowoop()), this);
3665       } else if (t->isa_klassptr()) {
3666         ciKlass* klass = t->is_klassptr()->exact_klass();
3667         if (klass->is_in_encoding_range()) {
3668           n->subsume_by(ConNode::make(t->make_narrowklass()), this);
3669         } else {
3670           assert(false, "unencodable klass in ConP -> EncodeP");
3671           C->record_failure("unencodable klass in ConP -> EncodeP");
3672         }
3673       }
3674     }
3675     if (in1->outcnt() == 0) {
3676       in1->disconnect_inputs(this);
3677     }
3678     break;
3679   }
3680 
3681   case Op_Proj: {
3682     if (OptimizeStringConcat || IncrementalInline) {
3683       ProjNode* proj = n->as_Proj();
3684       if (proj->_is_io_use) {
3685         assert(proj->_con == TypeFunc::I_O || proj->_con == TypeFunc::Memory, "");
3686         // Separate projections were used for the exception path which
3687         // are normally removed by a late inline.  If it wasn't inlined
3688         // then they will hang around and should just be replaced with
3689         // the original one. Merge them.
3690         Node* non_io_proj = proj->in(0)->as_Multi()->proj_out_or_null(proj->_con, false /*is_io_use*/);
3691         if (non_io_proj  != nullptr) {
3692           proj->subsume_by(non_io_proj , this);
3693         }
3694       }
3695     }
3696     break;
3697   }
3698 
3699   case Op_Phi:
3700     if (n->as_Phi()->bottom_type()->isa_narrowoop() || n->as_Phi()->bottom_type()->isa_narrowklass()) {
3701       // The EncodeP optimization may create Phi with the same edges
3702       // for all paths. It is not handled well by Register Allocator.
3703       Node* unique_in = n->in(1);
3704       assert(unique_in != nullptr, "");
3705       uint cnt = n->req();
3706       for (uint i = 2; i < cnt; i++) {
3707         Node* m = n->in(i);
3708         assert(m != nullptr, "");
3709         if (unique_in != m)
3710           unique_in = nullptr;
3711       }
3712       if (unique_in != nullptr) {
3713         n->subsume_by(unique_in, this);
3714       }
3715     }
3716     break;
3717 
3718 #endif
3719 
3720   case Op_ModI:
3721     handle_div_mod_op(n, T_INT, false);
3722     break;
3723 
3724   case Op_ModL:
3725     handle_div_mod_op(n, T_LONG, false);
3726     break;
3727 
3728   case Op_UModI:
3729     handle_div_mod_op(n, T_INT, true);
3730     break;
3731 
3732   case Op_UModL:
3733     handle_div_mod_op(n, T_LONG, true);
3734     break;
3735 
3736   case Op_LoadVector:
3737   case Op_StoreVector:
3738 #ifdef ASSERT
3739     // Add VerifyVectorAlignment node between adr and load / store.
3740     if (VerifyAlignVector && Matcher::has_match_rule(Op_VerifyVectorAlignment)) {
3741       bool must_verify_alignment = n->is_LoadVector() ? n->as_LoadVector()->must_verify_alignment() :
3742                                                         n->as_StoreVector()->must_verify_alignment();
3743       if (must_verify_alignment) {
3744         jlong vector_width = n->is_LoadVector() ? n->as_LoadVector()->memory_size() :
3745                                                   n->as_StoreVector()->memory_size();
3746         // The memory access should be aligned to the vector width in bytes.
3747         // However, the underlying array is possibly less well aligned, but at least
3748         // to ObjectAlignmentInBytes. Hence, even if multiple arrays are accessed in
3749         // a loop we can expect at least the following alignment:
3750         jlong guaranteed_alignment = MIN2(vector_width, (jlong)ObjectAlignmentInBytes);
3751         assert(2 <= guaranteed_alignment && guaranteed_alignment <= 64, "alignment must be in range");
3752         assert(is_power_of_2(guaranteed_alignment), "alignment must be power of 2");
3753         // Create mask from alignment. e.g. 0b1000 -> 0b0111
3754         jlong mask = guaranteed_alignment - 1;
3755         Node* mask_con = ConLNode::make(mask);
3756         VerifyVectorAlignmentNode* va = new VerifyVectorAlignmentNode(n->in(MemNode::Address), mask_con);
3757         n->set_req(MemNode::Address, va);
3758       }
3759     }
3760 #endif
3761     break;
3762 
3763   case Op_LoadVectorGather:
3764   case Op_StoreVectorScatter:
3765   case Op_LoadVectorGatherMasked:
3766   case Op_StoreVectorScatterMasked:
3767   case Op_VectorCmpMasked:
3768   case Op_VectorMaskGen:
3769   case Op_LoadVectorMasked:
3770   case Op_StoreVectorMasked:
3771     break;
3772 
3773   case Op_AddReductionVI:
3774   case Op_AddReductionVL:
3775   case Op_AddReductionVF:
3776   case Op_AddReductionVD:
3777   case Op_MulReductionVI:
3778   case Op_MulReductionVL:
3779   case Op_MulReductionVF:
3780   case Op_MulReductionVD:
3781   case Op_MinReductionV:
3782   case Op_MaxReductionV:
3783   case Op_AndReductionV:
3784   case Op_OrReductionV:
3785   case Op_XorReductionV:
3786     break;
3787 
3788   case Op_PackB:
3789   case Op_PackS:
3790   case Op_PackI:
3791   case Op_PackF:
3792   case Op_PackL:
3793   case Op_PackD:
3794     if (n->req()-1 > 2) {
3795       // Replace many operand PackNodes with a binary tree for matching
3796       PackNode* p = (PackNode*) n;
3797       Node* btp = p->binary_tree_pack(1, n->req());
3798       n->subsume_by(btp, this);
3799     }
3800     break;
3801   case Op_Loop:
3802     assert(!n->as_Loop()->is_loop_nest_inner_loop() || _loop_opts_cnt == 0, "should have been turned into a counted loop");
3803   case Op_CountedLoop:
3804   case Op_LongCountedLoop:
3805   case Op_OuterStripMinedLoop:
3806     if (n->as_Loop()->is_inner_loop()) {
3807       frc.inc_inner_loop_count();
3808     }
3809     n->as_Loop()->verify_strip_mined(0);
3810     break;
3811   case Op_LShiftI:
3812   case Op_RShiftI:
3813   case Op_URShiftI:
3814   case Op_LShiftL:
3815   case Op_RShiftL:
3816   case Op_URShiftL:
3817     if (Matcher::need_masked_shift_count) {
3818       // The cpu's shift instructions don't restrict the count to the
3819       // lower 5/6 bits. We need to do the masking ourselves.
3820       Node* in2 = n->in(2);
3821       juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
3822       const TypeInt* t = in2->find_int_type();
3823       if (t != nullptr && t->is_con()) {
3824         juint shift = t->get_con();
3825         if (shift > mask) { // Unsigned cmp
3826           n->set_req(2, ConNode::make(TypeInt::make(shift & mask)));
3827         }
3828       } else {
3829         if (t == nullptr || t->_lo < 0 || t->_hi > (int)mask) {
3830           Node* shift = new AndINode(in2, ConNode::make(TypeInt::make(mask)));
3831           n->set_req(2, shift);
3832         }
3833       }
3834       if (in2->outcnt() == 0) { // Remove dead node
3835         in2->disconnect_inputs(this);
3836       }
3837     }
3838     break;
3839   case Op_MemBarStoreStore:
3840   case Op_MemBarRelease:
3841     // Break the link with AllocateNode: it is no longer useful and
3842     // confuses register allocation.
3843     if (n->req() > MemBarNode::Precedent) {
3844       n->set_req(MemBarNode::Precedent, top());
3845     }
3846     break;
3847   case Op_MemBarAcquire: {
3848     if (n->as_MemBar()->trailing_load() && n->req() > MemBarNode::Precedent) {
3849       // At parse time, the trailing MemBarAcquire for a volatile load
3850       // is created with an edge to the load. After optimizations,
3851       // that input may be a chain of Phis. If those phis have no
3852       // other use, then the MemBarAcquire keeps them alive and
3853       // register allocation can be confused.
3854       dead_nodes.push(n->in(MemBarNode::Precedent));
3855       n->set_req(MemBarNode::Precedent, top());
3856     }
3857     break;
3858   }
3859   case Op_Blackhole:
3860     break;
3861   case Op_RangeCheck: {
3862     RangeCheckNode* rc = n->as_RangeCheck();
3863     Node* iff = new IfNode(rc->in(0), rc->in(1), rc->_prob, rc->_fcnt);
3864     n->subsume_by(iff, this);
3865     frc._tests.push(iff);
3866     break;
3867   }
3868   case Op_ConvI2L: {
3869     if (!Matcher::convi2l_type_required) {
3870       // Code generation on some platforms doesn't need accurate
3871       // ConvI2L types. Widening the type can help remove redundant
3872       // address computations.
3873       n->as_Type()->set_type(TypeLong::INT);
3874       ResourceMark rm;
3875       Unique_Node_List wq;
3876       wq.push(n);
3877       for (uint next = 0; next < wq.size(); next++) {
3878         Node *m = wq.at(next);
3879 
3880         for(;;) {
3881           // Loop over all nodes with identical inputs edges as m
3882           Node* k = m->find_similar(m->Opcode());
3883           if (k == nullptr) {
3884             break;
3885           }
3886           // Push their uses so we get a chance to remove node made
3887           // redundant
3888           for (DUIterator_Fast imax, i = k->fast_outs(imax); i < imax; i++) {
3889             Node* u = k->fast_out(i);
3890             if (u->Opcode() == Op_LShiftL ||
3891                 u->Opcode() == Op_AddL ||
3892                 u->Opcode() == Op_SubL ||
3893                 u->Opcode() == Op_AddP) {
3894               wq.push(u);
3895             }
3896           }
3897           // Replace all nodes with identical edges as m with m
3898           k->subsume_by(m, this);
3899         }
3900       }
3901     }
3902     break;
3903   }
3904   case Op_CmpUL: {
3905     if (!Matcher::has_match_rule(Op_CmpUL)) {
3906       // No support for unsigned long comparisons
3907       ConINode* sign_pos = new ConINode(TypeInt::make(BitsPerLong - 1));
3908       Node* sign_bit_mask = new RShiftLNode(n->in(1), sign_pos);
3909       Node* orl = new OrLNode(n->in(1), sign_bit_mask);
3910       ConLNode* remove_sign_mask = new ConLNode(TypeLong::make(max_jlong));
3911       Node* andl = new AndLNode(orl, remove_sign_mask);
3912       Node* cmp = new CmpLNode(andl, n->in(2));
3913       n->subsume_by(cmp, this);
3914     }
3915     break;
3916   }
3917 #ifdef ASSERT
3918   case Op_ConNKlass: {
3919     const TypePtr* tp = n->as_Type()->type()->make_ptr();
3920     ciKlass* klass = tp->is_klassptr()->exact_klass();
3921     assert(klass->is_in_encoding_range(), "klass cannot be compressed");
3922     break;
3923   }
3924 #endif
3925   default:
3926     assert(!n->is_Call(), "");
3927     assert(!n->is_Mem(), "");
3928     assert(nop != Op_ProfileBoolean, "should be eliminated during IGVN");
3929     break;
3930   }
3931 }
3932 
3933 //------------------------------final_graph_reshaping_walk---------------------
3934 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
3935 // requires that the walk visits a node's inputs before visiting the node.
3936 void Compile::final_graph_reshaping_walk(Node_Stack& nstack, Node* root, Final_Reshape_Counts& frc, Unique_Node_List& dead_nodes) {
3937   Unique_Node_List sfpt;
3938 
3939   frc._visited.set(root->_idx); // first, mark node as visited
3940   uint cnt = root->req();
3941   Node *n = root;
3942   uint  i = 0;
3943   while (true) {
3944     if (i < cnt) {
3945       // Place all non-visited non-null inputs onto stack
3946       Node* m = n->in(i);
3947       ++i;
3948       if (m != nullptr && !frc._visited.test_set(m->_idx)) {
3949         if (m->is_SafePoint() && m->as_SafePoint()->jvms() != nullptr) {
3950           // compute worst case interpreter size in case of a deoptimization
3951           update_interpreter_frame_size(m->as_SafePoint()->jvms()->interpreter_frame_size());
3952 
3953           sfpt.push(m);
3954         }
3955         cnt = m->req();
3956         nstack.push(n, i); // put on stack parent and next input's index
3957         n = m;
3958         i = 0;
3959       }
3960     } else {
3961       // Now do post-visit work
3962       final_graph_reshaping_impl(n, frc, dead_nodes);
3963       if (nstack.is_empty())
3964         break;             // finished
3965       n = nstack.node();   // Get node from stack
3966       cnt = n->req();
3967       i = nstack.index();
3968       nstack.pop();        // Shift to the next node on stack
3969     }
3970   }
3971 
3972   // Skip next transformation if compressed oops are not used.
3973   if ((UseCompressedOops && !Matcher::gen_narrow_oop_implicit_null_checks()) ||
3974       (!UseCompressedOops && !UseCompressedClassPointers))
3975     return;
3976 
3977   // Go over safepoints nodes to skip DecodeN/DecodeNKlass nodes for debug edges.
3978   // It could be done for an uncommon traps or any safepoints/calls
3979   // if the DecodeN/DecodeNKlass node is referenced only in a debug info.
3980   while (sfpt.size() > 0) {
3981     n = sfpt.pop();
3982     JVMState *jvms = n->as_SafePoint()->jvms();
3983     assert(jvms != nullptr, "sanity");
3984     int start = jvms->debug_start();
3985     int end   = n->req();
3986     bool is_uncommon = (n->is_CallStaticJava() &&
3987                         n->as_CallStaticJava()->uncommon_trap_request() != 0);
3988     for (int j = start; j < end; j++) {
3989       Node* in = n->in(j);
3990       if (in->is_DecodeNarrowPtr()) {
3991         bool safe_to_skip = true;
3992         if (!is_uncommon ) {
3993           // Is it safe to skip?
3994           for (uint i = 0; i < in->outcnt(); i++) {
3995             Node* u = in->raw_out(i);
3996             if (!u->is_SafePoint() ||
3997                 (u->is_Call() && u->as_Call()->has_non_debug_use(n))) {
3998               safe_to_skip = false;
3999             }
4000           }
4001         }
4002         if (safe_to_skip) {
4003           n->set_req(j, in->in(1));
4004         }
4005         if (in->outcnt() == 0) {
4006           in->disconnect_inputs(this);
4007         }
4008       }
4009     }
4010   }
4011 }
4012 
4013 //------------------------------final_graph_reshaping--------------------------
4014 // Final Graph Reshaping.
4015 //
4016 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
4017 //     and not commoned up and forced early.  Must come after regular
4018 //     optimizations to avoid GVN undoing the cloning.  Clone constant
4019 //     inputs to Loop Phis; these will be split by the allocator anyways.
4020 //     Remove Opaque nodes.
4021 // (2) Move last-uses by commutative operations to the left input to encourage
4022 //     Intel update-in-place two-address operations and better register usage
4023 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
4024 //     calls canonicalizing them back.
4025 // (3) Count the number of double-precision FP ops, single-precision FP ops
4026 //     and call sites.  On Intel, we can get correct rounding either by
4027 //     forcing singles to memory (requires extra stores and loads after each
4028 //     FP bytecode) or we can set a rounding mode bit (requires setting and
4029 //     clearing the mode bit around call sites).  The mode bit is only used
4030 //     if the relative frequency of single FP ops to calls is low enough.
4031 //     This is a key transform for SPEC mpeg_audio.
4032 // (4) Detect infinite loops; blobs of code reachable from above but not
4033 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
4034 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
4035 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
4036 //     Detection is by looking for IfNodes where only 1 projection is
4037 //     reachable from below or CatchNodes missing some targets.
4038 // (5) Assert for insane oop offsets in debug mode.
4039 
4040 bool Compile::final_graph_reshaping() {
4041   // an infinite loop may have been eliminated by the optimizer,
4042   // in which case the graph will be empty.
4043   if (root()->req() == 1) {
4044     // Do not compile method that is only a trivial infinite loop,
4045     // since the content of the loop may have been eliminated.
4046     record_method_not_compilable("trivial infinite loop");
4047     return true;
4048   }
4049 
4050   // Expensive nodes have their control input set to prevent the GVN
4051   // from freely commoning them. There's no GVN beyond this point so
4052   // no need to keep the control input. We want the expensive nodes to
4053   // be freely moved to the least frequent code path by gcm.
4054   assert(OptimizeExpensiveOps || expensive_count() == 0, "optimization off but list non empty?");
4055   for (int i = 0; i < expensive_count(); i++) {
4056     _expensive_nodes.at(i)->set_req(0, nullptr);
4057   }
4058 
4059   Final_Reshape_Counts frc;
4060 
4061   // Visit everybody reachable!
4062   // Allocate stack of size C->live_nodes()/2 to avoid frequent realloc
4063   Node_Stack nstack(live_nodes() >> 1);
4064   Unique_Node_List dead_nodes;
4065   final_graph_reshaping_walk(nstack, root(), frc, dead_nodes);
4066 
4067   // Check for unreachable (from below) code (i.e., infinite loops).
4068   for( uint i = 0; i < frc._tests.size(); i++ ) {
4069     MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
4070     // Get number of CFG targets.
4071     // Note that PCTables include exception targets after calls.
4072     uint required_outcnt = n->required_outcnt();
4073     if (n->outcnt() != required_outcnt) {
4074       // Check for a few special cases.  Rethrow Nodes never take the
4075       // 'fall-thru' path, so expected kids is 1 less.
4076       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
4077         if (n->in(0)->in(0)->is_Call()) {
4078           CallNode* call = n->in(0)->in(0)->as_Call();
4079           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
4080             required_outcnt--;      // Rethrow always has 1 less kid
4081           } else if (call->req() > TypeFunc::Parms &&
4082                      call->is_CallDynamicJava()) {
4083             // Check for null receiver. In such case, the optimizer has
4084             // detected that the virtual call will always result in a null
4085             // pointer exception. The fall-through projection of this CatchNode
4086             // will not be populated.
4087             Node* arg0 = call->in(TypeFunc::Parms);
4088             if (arg0->is_Type() &&
4089                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
4090               required_outcnt--;
4091             }
4092           } else if (call->entry_point() == OptoRuntime::new_array_Java() ||
4093                      call->entry_point() == OptoRuntime::new_array_nozero_Java()) {
4094             // Check for illegal array length. In such case, the optimizer has
4095             // detected that the allocation attempt will always result in an
4096             // exception. There is no fall-through projection of this CatchNode .
4097             assert(call->is_CallStaticJava(), "static call expected");
4098             assert(call->req() == call->jvms()->endoff() + 1, "missing extra input");
4099             uint valid_length_test_input = call->req() - 1;
4100             Node* valid_length_test = call->in(valid_length_test_input);
4101             call->del_req(valid_length_test_input);
4102             if (valid_length_test->find_int_con(1) == 0) {
4103               required_outcnt--;
4104             }
4105             dead_nodes.push(valid_length_test);
4106             assert(n->outcnt() == required_outcnt, "malformed control flow");
4107             continue;
4108           }
4109         }
4110       }
4111 
4112       // Recheck with a better notion of 'required_outcnt'
4113       if (n->outcnt() != required_outcnt) {
4114         record_method_not_compilable("malformed control flow");
4115         return true;            // Not all targets reachable!
4116       }
4117     } else if (n->is_PCTable() && n->in(0) && n->in(0)->in(0) && n->in(0)->in(0)->is_Call()) {
4118       CallNode* call = n->in(0)->in(0)->as_Call();
4119       if (call->entry_point() == OptoRuntime::new_array_Java() ||
4120           call->entry_point() == OptoRuntime::new_array_nozero_Java()) {
4121         assert(call->is_CallStaticJava(), "static call expected");
4122         assert(call->req() == call->jvms()->endoff() + 1, "missing extra input");
4123         uint valid_length_test_input = call->req() - 1;
4124         dead_nodes.push(call->in(valid_length_test_input));
4125         call->del_req(valid_length_test_input); // valid length test useless now
4126       }
4127     }
4128     // Check that I actually visited all kids.  Unreached kids
4129     // must be infinite loops.
4130     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
4131       if (!frc._visited.test(n->fast_out(j)->_idx)) {
4132         record_method_not_compilable("infinite loop");
4133         return true;            // Found unvisited kid; must be unreach
4134       }
4135 
4136     // Here so verification code in final_graph_reshaping_walk()
4137     // always see an OuterStripMinedLoopEnd
4138     if (n->is_OuterStripMinedLoopEnd() || n->is_LongCountedLoopEnd()) {
4139       IfNode* init_iff = n->as_If();
4140       Node* iff = new IfNode(init_iff->in(0), init_iff->in(1), init_iff->_prob, init_iff->_fcnt);
4141       n->subsume_by(iff, this);
4142     }
4143   }
4144 
4145   while (dead_nodes.size() > 0) {
4146     Node* m = dead_nodes.pop();
4147     if (m->outcnt() == 0 && m != top()) {
4148       for (uint j = 0; j < m->req(); j++) {
4149         Node* in = m->in(j);
4150         if (in != nullptr) {
4151           dead_nodes.push(in);
4152         }
4153       }
4154       m->disconnect_inputs(this);
4155     }
4156   }
4157 
4158   set_java_calls(frc.get_java_call_count());
4159   set_inner_loops(frc.get_inner_loop_count());
4160 
4161   // No infinite loops, no reason to bail out.
4162   return false;
4163 }
4164 
4165 //-----------------------------too_many_traps----------------------------------
4166 // Report if there are too many traps at the current method and bci.
4167 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
4168 bool Compile::too_many_traps(ciMethod* method,
4169                              int bci,
4170                              Deoptimization::DeoptReason reason) {
4171   ciMethodData* md = method->method_data();
4172   if (md->is_empty()) {
4173     // Assume the trap has not occurred, or that it occurred only
4174     // because of a transient condition during start-up in the interpreter.
4175     return false;
4176   }
4177   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : nullptr;
4178   if (md->has_trap_at(bci, m, reason) != 0) {
4179     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
4180     // Also, if there are multiple reasons, or if there is no per-BCI record,
4181     // assume the worst.
4182     if (log())
4183       log()->elem("observe trap='%s' count='%d'",
4184                   Deoptimization::trap_reason_name(reason),
4185                   md->trap_count(reason));
4186     return true;
4187   } else {
4188     // Ignore method/bci and see if there have been too many globally.
4189     return too_many_traps(reason, md);
4190   }
4191 }
4192 
4193 // Less-accurate variant which does not require a method and bci.
4194 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
4195                              ciMethodData* logmd) {
4196   if (trap_count(reason) >= Deoptimization::per_method_trap_limit(reason)) {
4197     // Too many traps globally.
4198     // Note that we use cumulative trap_count, not just md->trap_count.
4199     if (log()) {
4200       int mcount = (logmd == nullptr)? -1: (int)logmd->trap_count(reason);
4201       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
4202                   Deoptimization::trap_reason_name(reason),
4203                   mcount, trap_count(reason));
4204     }
4205     return true;
4206   } else {
4207     // The coast is clear.
4208     return false;
4209   }
4210 }
4211 
4212 //--------------------------too_many_recompiles--------------------------------
4213 // Report if there are too many recompiles at the current method and bci.
4214 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
4215 // Is not eager to return true, since this will cause the compiler to use
4216 // Action_none for a trap point, to avoid too many recompilations.
4217 bool Compile::too_many_recompiles(ciMethod* method,
4218                                   int bci,
4219                                   Deoptimization::DeoptReason reason) {
4220   ciMethodData* md = method->method_data();
4221   if (md->is_empty()) {
4222     // Assume the trap has not occurred, or that it occurred only
4223     // because of a transient condition during start-up in the interpreter.
4224     return false;
4225   }
4226   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
4227   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
4228   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
4229   Deoptimization::DeoptReason per_bc_reason
4230     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
4231   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : nullptr;
4232   if ((per_bc_reason == Deoptimization::Reason_none
4233        || md->has_trap_at(bci, m, reason) != 0)
4234       // The trap frequency measure we care about is the recompile count:
4235       && md->trap_recompiled_at(bci, m)
4236       && md->overflow_recompile_count() >= bc_cutoff) {
4237     // Do not emit a trap here if it has already caused recompilations.
4238     // Also, if there are multiple reasons, or if there is no per-BCI record,
4239     // assume the worst.
4240     if (log())
4241       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
4242                   Deoptimization::trap_reason_name(reason),
4243                   md->trap_count(reason),
4244                   md->overflow_recompile_count());
4245     return true;
4246   } else if (trap_count(reason) != 0
4247              && decompile_count() >= m_cutoff) {
4248     // Too many recompiles globally, and we have seen this sort of trap.
4249     // Use cumulative decompile_count, not just md->decompile_count.
4250     if (log())
4251       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
4252                   Deoptimization::trap_reason_name(reason),
4253                   md->trap_count(reason), trap_count(reason),
4254                   md->decompile_count(), decompile_count());
4255     return true;
4256   } else {
4257     // The coast is clear.
4258     return false;
4259   }
4260 }
4261 
4262 // Compute when not to trap. Used by matching trap based nodes and
4263 // NullCheck optimization.
4264 void Compile::set_allowed_deopt_reasons() {
4265   _allowed_reasons = 0;
4266   if (is_method_compilation()) {
4267     for (int rs = (int)Deoptimization::Reason_none+1; rs < Compile::trapHistLength; rs++) {
4268       assert(rs < BitsPerInt, "recode bit map");
4269       if (!too_many_traps((Deoptimization::DeoptReason) rs)) {
4270         _allowed_reasons |= nth_bit(rs);
4271       }
4272     }
4273   }
4274 }
4275 
4276 bool Compile::needs_clinit_barrier(ciMethod* method, ciMethod* accessing_method) {
4277   return method->is_static() && needs_clinit_barrier(method->holder(), accessing_method);
4278 }
4279 
4280 bool Compile::needs_clinit_barrier(ciField* field, ciMethod* accessing_method) {
4281   return field->is_static() && needs_clinit_barrier(field->holder(), accessing_method);
4282 }
4283 
4284 bool Compile::needs_clinit_barrier(ciInstanceKlass* holder, ciMethod* accessing_method) {
4285   if (holder->is_initialized()) {
4286     return false;
4287   }
4288   if (holder->is_being_initialized()) {
4289     if (accessing_method->holder() == holder) {
4290       // Access inside a class. The barrier can be elided when access happens in <clinit>,
4291       // <init>, or a static method. In all those cases, there was an initialization
4292       // barrier on the holder klass passed.
4293       if (accessing_method->is_static_initializer() ||
4294           accessing_method->is_object_initializer() ||
4295           accessing_method->is_static()) {
4296         return false;
4297       }
4298     } else if (accessing_method->holder()->is_subclass_of(holder)) {
4299       // Access from a subclass. The barrier can be elided only when access happens in <clinit>.
4300       // In case of <init> or a static method, the barrier is on the subclass is not enough:
4301       // child class can become fully initialized while its parent class is still being initialized.
4302       if (accessing_method->is_static_initializer()) {
4303         return false;
4304       }
4305     }
4306     ciMethod* root = method(); // the root method of compilation
4307     if (root != accessing_method) {
4308       return needs_clinit_barrier(holder, root); // check access in the context of compilation root
4309     }
4310   }
4311   return true;
4312 }
4313 
4314 #ifndef PRODUCT
4315 //------------------------------verify_bidirectional_edges---------------------
4316 // For each input edge to a node (ie - for each Use-Def edge), verify that
4317 // there is a corresponding Def-Use edge.
4318 void Compile::verify_bidirectional_edges(Unique_Node_List& visited, const Unique_Node_List* root_and_safepoints) const {
4319   // Allocate stack of size C->live_nodes()/16 to avoid frequent realloc
4320   uint stack_size = live_nodes() >> 4;
4321   Node_List nstack(MAX2(stack_size, (uint) OptoNodeListSize));
4322   if (root_and_safepoints != nullptr) {
4323     assert(root_and_safepoints->member(_root), "root is not in root_and_safepoints");
4324     for (uint i = 0, limit = root_and_safepoints->size(); i < limit; i++) {
4325       Node* root_or_safepoint = root_and_safepoints->at(i);
4326       // If the node is a safepoint, let's check if it still has a control input
4327       // Lack of control input signifies that this node was killed by CCP or
4328       // recursively by remove_globally_dead_node and it shouldn't be a starting
4329       // point.
4330       if (!root_or_safepoint->is_SafePoint() || root_or_safepoint->in(0) != nullptr) {
4331         nstack.push(root_or_safepoint);
4332       }
4333     }
4334   } else {
4335     nstack.push(_root);
4336   }
4337 
4338   while (nstack.size() > 0) {
4339     Node* n = nstack.pop();
4340     if (visited.member(n)) {
4341       continue;
4342     }
4343     visited.push(n);
4344 
4345     // Walk over all input edges, checking for correspondence
4346     uint length = n->len();
4347     for (uint i = 0; i < length; i++) {
4348       Node* in = n->in(i);
4349       if (in != nullptr && !visited.member(in)) {
4350         nstack.push(in); // Put it on stack
4351       }
4352       if (in != nullptr && !in->is_top()) {
4353         // Count instances of `next`
4354         int cnt = 0;
4355         for (uint idx = 0; idx < in->_outcnt; idx++) {
4356           if (in->_out[idx] == n) {
4357             cnt++;
4358           }
4359         }
4360         assert(cnt > 0, "Failed to find Def-Use edge.");
4361         // Check for duplicate edges
4362         // walk the input array downcounting the input edges to n
4363         for (uint j = 0; j < length; j++) {
4364           if (n->in(j) == in) {
4365             cnt--;
4366           }
4367         }
4368         assert(cnt == 0, "Mismatched edge count.");
4369       } else if (in == nullptr) {
4370         assert(i == 0 || i >= n->req() ||
4371                n->is_Region() || n->is_Phi() || n->is_ArrayCopy() ||
4372                (n->is_Unlock() && i == (n->req() - 1)) ||
4373                (n->is_MemBar() && i == 5), // the precedence edge to a membar can be removed during macro node expansion
4374               "only region, phi, arraycopy, unlock or membar nodes have null data edges");
4375       } else {
4376         assert(in->is_top(), "sanity");
4377         // Nothing to check.
4378       }
4379     }
4380   }
4381 }
4382 
4383 //------------------------------verify_graph_edges---------------------------
4384 // Walk the Graph and verify that there is a one-to-one correspondence
4385 // between Use-Def edges and Def-Use edges in the graph.
4386 void Compile::verify_graph_edges(bool no_dead_code, const Unique_Node_List* root_and_safepoints) const {
4387   if (VerifyGraphEdges) {
4388     Unique_Node_List visited;
4389 
4390     // Call graph walk to check edges
4391     verify_bidirectional_edges(visited, root_and_safepoints);
4392     if (no_dead_code) {
4393       // Now make sure that no visited node is used by an unvisited node.
4394       bool dead_nodes = false;
4395       Unique_Node_List checked;
4396       while (visited.size() > 0) {
4397         Node* n = visited.pop();
4398         checked.push(n);
4399         for (uint i = 0; i < n->outcnt(); i++) {
4400           Node* use = n->raw_out(i);
4401           if (checked.member(use))  continue;  // already checked
4402           if (visited.member(use))  continue;  // already in the graph
4403           if (use->is_Con())        continue;  // a dead ConNode is OK
4404           // At this point, we have found a dead node which is DU-reachable.
4405           if (!dead_nodes) {
4406             tty->print_cr("*** Dead nodes reachable via DU edges:");
4407             dead_nodes = true;
4408           }
4409           use->dump(2);
4410           tty->print_cr("---");
4411           checked.push(use);  // No repeats; pretend it is now checked.
4412         }
4413       }
4414       assert(!dead_nodes, "using nodes must be reachable from root");
4415     }
4416   }
4417 }
4418 #endif
4419 
4420 // The Compile object keeps track of failure reasons separately from the ciEnv.
4421 // This is required because there is not quite a 1-1 relation between the
4422 // ciEnv and its compilation task and the Compile object.  Note that one
4423 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
4424 // to backtrack and retry without subsuming loads.  Other than this backtracking
4425 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
4426 // by the logic in C2Compiler.
4427 void Compile::record_failure(const char* reason DEBUG_ONLY(COMMA bool allow_multiple_failures)) {
4428   if (log() != nullptr) {
4429     log()->elem("failure reason='%s' phase='compile'", reason);
4430   }
4431   if (_failure_reason.get() == nullptr) {
4432     // Record the first failure reason.
4433     _failure_reason.set(reason);
4434     if (CaptureBailoutInformation) {
4435       _first_failure_details = new CompilationFailureInfo(reason);
4436     }
4437   } else {
4438     assert(!StressBailout || allow_multiple_failures, "should have handled previous failure.");
4439   }
4440 
4441   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
4442     C->print_method(PHASE_FAILURE, 1);
4443   }
4444   _root = nullptr;  // flush the graph, too
4445 }
4446 
4447 Compile::TracePhase::TracePhase(const char* name, PhaseTraceId id)
4448   : TraceTime(name, &Phase::timers[id], CITime, CITimeVerbose),
4449     _compile(Compile::current()),
4450     _log(nullptr),
4451     _dolog(CITimeVerbose)
4452 {
4453   assert(_compile != nullptr, "sanity check");
4454   assert(id != PhaseTraceId::_t_none, "Don't use none");
4455   if (_dolog) {
4456     _log = _compile->log();
4457   }
4458   if (_log != nullptr) {
4459     _log->begin_head("phase name='%s' nodes='%d' live='%d'", phase_name(), _compile->unique(), _compile->live_nodes());
4460     _log->stamp();
4461     _log->end_head();
4462   }
4463 
4464   // Inform memory statistic, if enabled
4465   if (CompilationMemoryStatistic::enabled()) {
4466     CompilationMemoryStatistic::on_phase_start((int)id, name);
4467   }
4468 }
4469 
4470 Compile::TracePhase::TracePhase(PhaseTraceId id)
4471   : TracePhase(Phase::get_phase_trace_id_text(id), id) {}
4472 
4473 Compile::TracePhase::~TracePhase() {
4474 
4475   // Inform memory statistic, if enabled
4476   if (CompilationMemoryStatistic::enabled()) {
4477     CompilationMemoryStatistic::on_phase_end();
4478   }
4479 
4480   if (_compile->failing_internal()) {
4481     if (_log != nullptr) {
4482       _log->done("phase");
4483     }
4484     return; // timing code, not stressing bailouts.
4485   }
4486 #ifdef ASSERT
4487   if (PrintIdealNodeCount) {
4488     tty->print_cr("phase name='%s' nodes='%d' live='%d' live_graph_walk='%d'",
4489                   phase_name(), _compile->unique(), _compile->live_nodes(), _compile->count_live_nodes_by_graph_walk());
4490   }
4491 
4492   if (VerifyIdealNodeCount) {
4493     _compile->print_missing_nodes();
4494   }
4495 #endif
4496 
4497   if (_log != nullptr) {
4498     _log->done("phase name='%s' nodes='%d' live='%d'", phase_name(), _compile->unique(), _compile->live_nodes());
4499   }
4500 }
4501 
4502 //----------------------------static_subtype_check-----------------------------
4503 // Shortcut important common cases when superklass is exact:
4504 // (0) superklass is java.lang.Object (can occur in reflective code)
4505 // (1) subklass is already limited to a subtype of superklass => always ok
4506 // (2) subklass does not overlap with superklass => always fail
4507 // (3) superklass has NO subtypes and we can check with a simple compare.
4508 Compile::SubTypeCheckResult Compile::static_subtype_check(const TypeKlassPtr* superk, const TypeKlassPtr* subk, bool skip) {
4509   if (skip) {
4510     return SSC_full_test;       // Let caller generate the general case.
4511   }
4512 
4513   if (subk->is_java_subtype_of(superk)) {
4514     return SSC_always_true; // (0) and (1)  this test cannot fail
4515   }
4516 
4517   if (!subk->maybe_java_subtype_of(superk)) {
4518     return SSC_always_false; // (2) true path dead; no dynamic test needed
4519   }
4520 
4521   const Type* superelem = superk;
4522   if (superk->isa_aryklassptr()) {
4523     int ignored;
4524     superelem = superk->is_aryklassptr()->base_element_type(ignored);
4525   }
4526 
4527   if (superelem->isa_instklassptr()) {
4528     ciInstanceKlass* ik = superelem->is_instklassptr()->instance_klass();
4529     if (!ik->has_subklass()) {
4530       if (!ik->is_final()) {
4531         // Add a dependency if there is a chance of a later subclass.
4532         dependencies()->assert_leaf_type(ik);
4533       }
4534       if (!superk->maybe_java_subtype_of(subk)) {
4535         return SSC_always_false;
4536       }
4537       return SSC_easy_test;     // (3) caller can do a simple ptr comparison
4538     }
4539   } else {
4540     // A primitive array type has no subtypes.
4541     return SSC_easy_test;       // (3) caller can do a simple ptr comparison
4542   }
4543 
4544   return SSC_full_test;
4545 }
4546 
4547 Node* Compile::conv_I2X_index(PhaseGVN* phase, Node* idx, const TypeInt* sizetype, Node* ctrl) {
4548 #ifdef _LP64
4549   // The scaled index operand to AddP must be a clean 64-bit value.
4550   // Java allows a 32-bit int to be incremented to a negative
4551   // value, which appears in a 64-bit register as a large
4552   // positive number.  Using that large positive number as an
4553   // operand in pointer arithmetic has bad consequences.
4554   // On the other hand, 32-bit overflow is rare, and the possibility
4555   // can often be excluded, if we annotate the ConvI2L node with
4556   // a type assertion that its value is known to be a small positive
4557   // number.  (The prior range check has ensured this.)
4558   // This assertion is used by ConvI2LNode::Ideal.
4559   int index_max = max_jint - 1;  // array size is max_jint, index is one less
4560   if (sizetype != nullptr && sizetype->_hi > 0) {
4561     index_max = sizetype->_hi - 1;
4562   }
4563   const TypeInt* iidxtype = TypeInt::make(0, index_max, Type::WidenMax);
4564   idx = constrained_convI2L(phase, idx, iidxtype, ctrl);
4565 #endif
4566   return idx;
4567 }
4568 
4569 // Convert integer value to a narrowed long type dependent on ctrl (for example, a range check)
4570 Node* Compile::constrained_convI2L(PhaseGVN* phase, Node* value, const TypeInt* itype, Node* ctrl, bool carry_dependency) {
4571   if (ctrl != nullptr) {
4572     // Express control dependency by a CastII node with a narrow type.
4573     // Make the CastII node dependent on the control input to prevent the narrowed ConvI2L
4574     // node from floating above the range check during loop optimizations. Otherwise, the
4575     // ConvI2L node may be eliminated independently of the range check, causing the data path
4576     // to become TOP while the control path is still there (although it's unreachable).
4577     value = new CastIINode(ctrl, value, itype, carry_dependency ? ConstraintCastNode::DependencyType::NonFloatingNarrowing : ConstraintCastNode::DependencyType::FloatingNarrowing, true /* range check dependency */);
4578     value = phase->transform(value);
4579   }
4580   const TypeLong* ltype = TypeLong::make(itype->_lo, itype->_hi, itype->_widen);
4581   return phase->transform(new ConvI2LNode(value, ltype));
4582 }
4583 
4584 void Compile::dump_print_inlining() {
4585   inline_printer()->print_on(tty);
4586 }
4587 
4588 void Compile::log_late_inline(CallGenerator* cg) {
4589   if (log() != nullptr) {
4590     log()->head("late_inline method='%d' inline_id='" JLONG_FORMAT "'", log()->identify(cg->method()),
4591                 cg->unique_id());
4592     JVMState* p = cg->call_node()->jvms();
4593     while (p != nullptr) {
4594       log()->elem("jvms bci='%d' method='%d'", p->bci(), log()->identify(p->method()));
4595       p = p->caller();
4596     }
4597     log()->tail("late_inline");
4598   }
4599 }
4600 
4601 void Compile::log_late_inline_failure(CallGenerator* cg, const char* msg) {
4602   log_late_inline(cg);
4603   if (log() != nullptr) {
4604     log()->inline_fail(msg);
4605   }
4606 }
4607 
4608 void Compile::log_inline_id(CallGenerator* cg) {
4609   if (log() != nullptr) {
4610     // The LogCompilation tool needs a unique way to identify late
4611     // inline call sites. This id must be unique for this call site in
4612     // this compilation. Try to have it unique across compilations as
4613     // well because it can be convenient when grepping through the log
4614     // file.
4615     // Distinguish OSR compilations from others in case CICountOSR is
4616     // on.
4617     jlong id = ((jlong)unique()) + (((jlong)compile_id()) << 33) + (CICountOSR && is_osr_compilation() ? ((jlong)1) << 32 : 0);
4618     cg->set_unique_id(id);
4619     log()->elem("inline_id id='" JLONG_FORMAT "'", id);
4620   }
4621 }
4622 
4623 void Compile::log_inline_failure(const char* msg) {
4624   if (C->log() != nullptr) {
4625     C->log()->inline_fail(msg);
4626   }
4627 }
4628 
4629 
4630 // Dump inlining replay data to the stream.
4631 // Don't change thread state and acquire any locks.
4632 void Compile::dump_inline_data(outputStream* out) {
4633   InlineTree* inl_tree = ilt();
4634   if (inl_tree != nullptr) {
4635     out->print(" inline %d", inl_tree->count());
4636     inl_tree->dump_replay_data(out);
4637   }
4638 }
4639 
4640 void Compile::dump_inline_data_reduced(outputStream* out) {
4641   assert(ReplayReduce, "");
4642 
4643   InlineTree* inl_tree = ilt();
4644   if (inl_tree == nullptr) {
4645     return;
4646   }
4647   // Enable iterative replay file reduction
4648   // Output "compile" lines for depth 1 subtrees,
4649   // simulating that those trees were compiled
4650   // instead of inlined.
4651   for (int i = 0; i < inl_tree->subtrees().length(); ++i) {
4652     InlineTree* sub = inl_tree->subtrees().at(i);
4653     if (sub->inline_level() != 1) {
4654       continue;
4655     }
4656 
4657     ciMethod* method = sub->method();
4658     int entry_bci = -1;
4659     int comp_level = env()->task()->comp_level();
4660     out->print("compile ");
4661     method->dump_name_as_ascii(out);
4662     out->print(" %d %d", entry_bci, comp_level);
4663     out->print(" inline %d", sub->count());
4664     sub->dump_replay_data(out, -1);
4665     out->cr();
4666   }
4667 }
4668 
4669 int Compile::cmp_expensive_nodes(Node* n1, Node* n2) {
4670   if (n1->Opcode() < n2->Opcode())      return -1;
4671   else if (n1->Opcode() > n2->Opcode()) return 1;
4672 
4673   assert(n1->req() == n2->req(), "can't compare %s nodes: n1->req() = %d, n2->req() = %d", NodeClassNames[n1->Opcode()], n1->req(), n2->req());
4674   for (uint i = 1; i < n1->req(); i++) {
4675     if (n1->in(i) < n2->in(i))      return -1;
4676     else if (n1->in(i) > n2->in(i)) return 1;
4677   }
4678 
4679   return 0;
4680 }
4681 
4682 int Compile::cmp_expensive_nodes(Node** n1p, Node** n2p) {
4683   Node* n1 = *n1p;
4684   Node* n2 = *n2p;
4685 
4686   return cmp_expensive_nodes(n1, n2);
4687 }
4688 
4689 void Compile::sort_expensive_nodes() {
4690   if (!expensive_nodes_sorted()) {
4691     _expensive_nodes.sort(cmp_expensive_nodes);
4692   }
4693 }
4694 
4695 bool Compile::expensive_nodes_sorted() const {
4696   for (int i = 1; i < _expensive_nodes.length(); i++) {
4697     if (cmp_expensive_nodes(_expensive_nodes.adr_at(i), _expensive_nodes.adr_at(i-1)) < 0) {
4698       return false;
4699     }
4700   }
4701   return true;
4702 }
4703 
4704 bool Compile::should_optimize_expensive_nodes(PhaseIterGVN &igvn) {
4705   if (_expensive_nodes.length() == 0) {
4706     return false;
4707   }
4708 
4709   assert(OptimizeExpensiveOps, "optimization off?");
4710 
4711   // Take this opportunity to remove dead nodes from the list
4712   int j = 0;
4713   for (int i = 0; i < _expensive_nodes.length(); i++) {
4714     Node* n = _expensive_nodes.at(i);
4715     if (!n->is_unreachable(igvn)) {
4716       assert(n->is_expensive(), "should be expensive");
4717       _expensive_nodes.at_put(j, n);
4718       j++;
4719     }
4720   }
4721   _expensive_nodes.trunc_to(j);
4722 
4723   // Then sort the list so that similar nodes are next to each other
4724   // and check for at least two nodes of identical kind with same data
4725   // inputs.
4726   sort_expensive_nodes();
4727 
4728   for (int i = 0; i < _expensive_nodes.length()-1; i++) {
4729     if (cmp_expensive_nodes(_expensive_nodes.adr_at(i), _expensive_nodes.adr_at(i+1)) == 0) {
4730       return true;
4731     }
4732   }
4733 
4734   return false;
4735 }
4736 
4737 void Compile::cleanup_expensive_nodes(PhaseIterGVN &igvn) {
4738   if (_expensive_nodes.length() == 0) {
4739     return;
4740   }
4741 
4742   assert(OptimizeExpensiveOps, "optimization off?");
4743 
4744   // Sort to bring similar nodes next to each other and clear the
4745   // control input of nodes for which there's only a single copy.
4746   sort_expensive_nodes();
4747 
4748   int j = 0;
4749   int identical = 0;
4750   int i = 0;
4751   bool modified = false;
4752   for (; i < _expensive_nodes.length()-1; i++) {
4753     assert(j <= i, "can't write beyond current index");
4754     if (_expensive_nodes.at(i)->Opcode() == _expensive_nodes.at(i+1)->Opcode()) {
4755       identical++;
4756       _expensive_nodes.at_put(j++, _expensive_nodes.at(i));
4757       continue;
4758     }
4759     if (identical > 0) {
4760       _expensive_nodes.at_put(j++, _expensive_nodes.at(i));
4761       identical = 0;
4762     } else {
4763       Node* n = _expensive_nodes.at(i);
4764       igvn.replace_input_of(n, 0, nullptr);
4765       igvn.hash_insert(n);
4766       modified = true;
4767     }
4768   }
4769   if (identical > 0) {
4770     _expensive_nodes.at_put(j++, _expensive_nodes.at(i));
4771   } else if (_expensive_nodes.length() >= 1) {
4772     Node* n = _expensive_nodes.at(i);
4773     igvn.replace_input_of(n, 0, nullptr);
4774     igvn.hash_insert(n);
4775     modified = true;
4776   }
4777   _expensive_nodes.trunc_to(j);
4778   if (modified) {
4779     igvn.optimize();
4780   }
4781 }
4782 
4783 void Compile::add_expensive_node(Node * n) {
4784   assert(!_expensive_nodes.contains(n), "duplicate entry in expensive list");
4785   assert(n->is_expensive(), "expensive nodes with non-null control here only");
4786   assert(!n->is_CFG() && !n->is_Mem(), "no cfg or memory nodes here");
4787   if (OptimizeExpensiveOps) {
4788     _expensive_nodes.append(n);
4789   } else {
4790     // Clear control input and let IGVN optimize expensive nodes if
4791     // OptimizeExpensiveOps is off.
4792     n->set_req(0, nullptr);
4793   }
4794 }
4795 
4796 /**
4797  * Track coarsened Lock and Unlock nodes.
4798  */
4799 
4800 class Lock_List : public Node_List {
4801   uint _origin_cnt;
4802 public:
4803   Lock_List(Arena *a, uint cnt) : Node_List(a), _origin_cnt(cnt) {}
4804   uint origin_cnt() const { return _origin_cnt; }
4805 };
4806 
4807 void Compile::add_coarsened_locks(GrowableArray<AbstractLockNode*>& locks) {
4808   int length = locks.length();
4809   if (length > 0) {
4810     // Have to keep this list until locks elimination during Macro nodes elimination.
4811     Lock_List* locks_list = new (comp_arena()) Lock_List(comp_arena(), length);
4812     AbstractLockNode* alock = locks.at(0);
4813     BoxLockNode* box = alock->box_node()->as_BoxLock();
4814     for (int i = 0; i < length; i++) {
4815       AbstractLockNode* lock = locks.at(i);
4816       assert(lock->is_coarsened(), "expecting only coarsened AbstractLock nodes, but got '%s'[%d] node", lock->Name(), lock->_idx);
4817       locks_list->push(lock);
4818       BoxLockNode* this_box = lock->box_node()->as_BoxLock();
4819       if (this_box != box) {
4820         // Locking regions (BoxLock) could be Unbalanced here:
4821         //  - its coarsened locks were eliminated in earlier
4822         //    macro nodes elimination followed by loop unroll
4823         //  - it is OSR locking region (no Lock node)
4824         // Preserve Unbalanced status in such cases.
4825         if (!this_box->is_unbalanced()) {
4826           this_box->set_coarsened();
4827         }
4828         if (!box->is_unbalanced()) {
4829           box->set_coarsened();
4830         }
4831       }
4832     }
4833     _coarsened_locks.append(locks_list);
4834   }
4835 }
4836 
4837 void Compile::remove_useless_coarsened_locks(Unique_Node_List& useful) {
4838   int count = coarsened_count();
4839   for (int i = 0; i < count; i++) {
4840     Node_List* locks_list = _coarsened_locks.at(i);
4841     for (uint j = 0; j < locks_list->size(); j++) {
4842       Node* lock = locks_list->at(j);
4843       assert(lock->is_AbstractLock(), "sanity");
4844       if (!useful.member(lock)) {
4845         locks_list->yank(lock);
4846       }
4847     }
4848   }
4849 }
4850 
4851 void Compile::remove_coarsened_lock(Node* n) {
4852   if (n->is_AbstractLock()) {
4853     int count = coarsened_count();
4854     for (int i = 0; i < count; i++) {
4855       Node_List* locks_list = _coarsened_locks.at(i);
4856       locks_list->yank(n);
4857     }
4858   }
4859 }
4860 
4861 bool Compile::coarsened_locks_consistent() {
4862   int count = coarsened_count();
4863   for (int i = 0; i < count; i++) {
4864     bool unbalanced = false;
4865     bool modified = false; // track locks kind modifications
4866     Lock_List* locks_list = (Lock_List*)_coarsened_locks.at(i);
4867     uint size = locks_list->size();
4868     if (size == 0) {
4869       unbalanced = false; // All locks were eliminated - good
4870     } else if (size != locks_list->origin_cnt()) {
4871       unbalanced = true; // Some locks were removed from list
4872     } else {
4873       for (uint j = 0; j < size; j++) {
4874         Node* lock = locks_list->at(j);
4875         // All nodes in group should have the same state (modified or not)
4876         if (!lock->as_AbstractLock()->is_coarsened()) {
4877           if (j == 0) {
4878             // first on list was modified, the rest should be too for consistency
4879             modified = true;
4880           } else if (!modified) {
4881             // this lock was modified but previous locks on the list were not
4882             unbalanced = true;
4883             break;
4884           }
4885         } else if (modified) {
4886           // previous locks on list were modified but not this lock
4887           unbalanced = true;
4888           break;
4889         }
4890       }
4891     }
4892     if (unbalanced) {
4893       // unbalanced monitor enter/exit - only some [un]lock nodes were removed or modified
4894 #ifdef ASSERT
4895       if (PrintEliminateLocks) {
4896         tty->print_cr("=== unbalanced coarsened locks ===");
4897         for (uint l = 0; l < size; l++) {
4898           locks_list->at(l)->dump();
4899         }
4900       }
4901 #endif
4902       record_failure(C2Compiler::retry_no_locks_coarsening());
4903       return false;
4904     }
4905   }
4906   return true;
4907 }
4908 
4909 // Mark locking regions (identified by BoxLockNode) as unbalanced if
4910 // locks coarsening optimization removed Lock/Unlock nodes from them.
4911 // Such regions become unbalanced because coarsening only removes part
4912 // of Lock/Unlock nodes in region. As result we can't execute other
4913 // locks elimination optimizations which assume all code paths have
4914 // corresponding pair of Lock/Unlock nodes - they are balanced.
4915 void Compile::mark_unbalanced_boxes() const {
4916   int count = coarsened_count();
4917   for (int i = 0; i < count; i++) {
4918     Node_List* locks_list = _coarsened_locks.at(i);
4919     uint size = locks_list->size();
4920     if (size > 0) {
4921       AbstractLockNode* alock = locks_list->at(0)->as_AbstractLock();
4922       BoxLockNode* box = alock->box_node()->as_BoxLock();
4923       if (alock->is_coarsened()) {
4924         // coarsened_locks_consistent(), which is called before this method, verifies
4925         // that the rest of Lock/Unlock nodes on locks_list are also coarsened.
4926         assert(!box->is_eliminated(), "regions with coarsened locks should not be marked as eliminated");
4927         for (uint j = 1; j < size; j++) {
4928           assert(locks_list->at(j)->as_AbstractLock()->is_coarsened(), "only coarsened locks are expected here");
4929           BoxLockNode* this_box = locks_list->at(j)->as_AbstractLock()->box_node()->as_BoxLock();
4930           if (box != this_box) {
4931             assert(!this_box->is_eliminated(), "regions with coarsened locks should not be marked as eliminated");
4932             box->set_unbalanced();
4933             this_box->set_unbalanced();
4934           }
4935         }
4936       }
4937     }
4938   }
4939 }
4940 
4941 /**
4942  * Remove the speculative part of types and clean up the graph
4943  */
4944 void Compile::remove_speculative_types(PhaseIterGVN &igvn) {
4945   if (UseTypeSpeculation) {
4946     Unique_Node_List worklist;
4947     worklist.push(root());
4948     int modified = 0;
4949     // Go over all type nodes that carry a speculative type, drop the
4950     // speculative part of the type and enqueue the node for an igvn
4951     // which may optimize it out.
4952     for (uint next = 0; next < worklist.size(); ++next) {
4953       Node *n  = worklist.at(next);
4954       if (n->is_Type()) {
4955         TypeNode* tn = n->as_Type();
4956         const Type* t = tn->type();
4957         const Type* t_no_spec = t->remove_speculative();
4958         if (t_no_spec != t) {
4959           bool in_hash = igvn.hash_delete(n);
4960           assert(in_hash || n->hash() == Node::NO_HASH, "node should be in igvn hash table");
4961           tn->set_type(t_no_spec);
4962           igvn.hash_insert(n);
4963           igvn._worklist.push(n); // give it a chance to go away
4964           modified++;
4965         }
4966       }
4967       // Iterate over outs - endless loops is unreachable from below
4968       for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
4969         Node *m = n->fast_out(i);
4970         if (not_a_node(m)) {
4971           continue;
4972         }
4973         worklist.push(m);
4974       }
4975     }
4976     // Drop the speculative part of all types in the igvn's type table
4977     igvn.remove_speculative_types();
4978     if (modified > 0) {
4979       igvn.optimize();
4980       if (failing())  return;
4981     }
4982 #ifdef ASSERT
4983     // Verify that after the IGVN is over no speculative type has resurfaced
4984     worklist.clear();
4985     worklist.push(root());
4986     for (uint next = 0; next < worklist.size(); ++next) {
4987       Node *n  = worklist.at(next);
4988       const Type* t = igvn.type_or_null(n);
4989       assert((t == nullptr) || (t == t->remove_speculative()), "no more speculative types");
4990       if (n->is_Type()) {
4991         t = n->as_Type()->type();
4992         assert(t == t->remove_speculative(), "no more speculative types");
4993       }
4994       // Iterate over outs - endless loops is unreachable from below
4995       for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
4996         Node *m = n->fast_out(i);
4997         if (not_a_node(m)) {
4998           continue;
4999         }
5000         worklist.push(m);
5001       }
5002     }
5003     igvn.check_no_speculative_types();
5004 #endif
5005   }
5006 }
5007 
5008 // Auxiliary methods to support randomized stressing/fuzzing.
5009 
5010 void Compile::initialize_stress_seed(const DirectiveSet* directive) {
5011   if (FLAG_IS_DEFAULT(StressSeed) || (FLAG_IS_ERGO(StressSeed) && directive->RepeatCompilationOption)) {
5012     _stress_seed = static_cast<uint>(Ticks::now().nanoseconds());
5013     FLAG_SET_ERGO(StressSeed, _stress_seed);
5014   } else {
5015     _stress_seed = StressSeed;
5016   }
5017   if (_log != nullptr) {
5018     _log->elem("stress_test seed='%u'", _stress_seed);
5019   }
5020 }
5021 
5022 int Compile::random() {
5023   _stress_seed = os::next_random(_stress_seed);
5024   return static_cast<int>(_stress_seed);
5025 }
5026 
5027 // This method can be called the arbitrary number of times, with current count
5028 // as the argument. The logic allows selecting a single candidate from the
5029 // running list of candidates as follows:
5030 //    int count = 0;
5031 //    Cand* selected = null;
5032 //    while(cand = cand->next()) {
5033 //      if (randomized_select(++count)) {
5034 //        selected = cand;
5035 //      }
5036 //    }
5037 //
5038 // Including count equalizes the chances any candidate is "selected".
5039 // This is useful when we don't have the complete list of candidates to choose
5040 // from uniformly. In this case, we need to adjust the randomicity of the
5041 // selection, or else we will end up biasing the selection towards the latter
5042 // candidates.
5043 //
5044 // Quick back-envelope calculation shows that for the list of n candidates
5045 // the equal probability for the candidate to persist as "best" can be
5046 // achieved by replacing it with "next" k-th candidate with the probability
5047 // of 1/k. It can be easily shown that by the end of the run, the
5048 // probability for any candidate is converged to 1/n, thus giving the
5049 // uniform distribution among all the candidates.
5050 //
5051 // We don't care about the domain size as long as (RANDOMIZED_DOMAIN / count) is large.
5052 #define RANDOMIZED_DOMAIN_POW 29
5053 #define RANDOMIZED_DOMAIN (1 << RANDOMIZED_DOMAIN_POW)
5054 #define RANDOMIZED_DOMAIN_MASK ((1 << (RANDOMIZED_DOMAIN_POW + 1)) - 1)
5055 bool Compile::randomized_select(int count) {
5056   assert(count > 0, "only positive");
5057   return (random() & RANDOMIZED_DOMAIN_MASK) < (RANDOMIZED_DOMAIN / count);
5058 }
5059 
5060 #ifdef ASSERT
5061 // Failures are geometrically distributed with probability 1/StressBailoutMean.
5062 bool Compile::fail_randomly() {
5063   if ((random() % StressBailoutMean) != 0) {
5064     return false;
5065   }
5066   record_failure("StressBailout");
5067   return true;
5068 }
5069 
5070 bool Compile::failure_is_artificial() {
5071   return C->failure_reason_is("StressBailout");
5072 }
5073 #endif
5074 
5075 CloneMap&     Compile::clone_map()                 { return _clone_map; }
5076 void          Compile::set_clone_map(Dict* d)      { _clone_map._dict = d; }
5077 
5078 void NodeCloneInfo::dump_on(outputStream* st) const {
5079   st->print(" {%d:%d} ", idx(), gen());
5080 }
5081 
5082 void CloneMap::clone(Node* old, Node* nnn, int gen) {
5083   uint64_t val = value(old->_idx);
5084   NodeCloneInfo cio(val);
5085   assert(val != 0, "old node should be in the map");
5086   NodeCloneInfo cin(cio.idx(), gen + cio.gen());
5087   insert(nnn->_idx, cin.get());
5088 #ifndef PRODUCT
5089   if (is_debug()) {
5090     tty->print_cr("CloneMap::clone inserted node %d info {%d:%d} into CloneMap", nnn->_idx, cin.idx(), cin.gen());
5091   }
5092 #endif
5093 }
5094 
5095 void CloneMap::verify_insert_and_clone(Node* old, Node* nnn, int gen) {
5096   NodeCloneInfo cio(value(old->_idx));
5097   if (cio.get() == 0) {
5098     cio.set(old->_idx, 0);
5099     insert(old->_idx, cio.get());
5100 #ifndef PRODUCT
5101     if (is_debug()) {
5102       tty->print_cr("CloneMap::verify_insert_and_clone inserted node %d info {%d:%d} into CloneMap", old->_idx, cio.idx(), cio.gen());
5103     }
5104 #endif
5105   }
5106   clone(old, nnn, gen);
5107 }
5108 
5109 int CloneMap::max_gen() const {
5110   int g = 0;
5111   DictI di(_dict);
5112   for(; di.test(); ++di) {
5113     int t = gen(di._key);
5114     if (g < t) {
5115       g = t;
5116 #ifndef PRODUCT
5117       if (is_debug()) {
5118         tty->print_cr("CloneMap::max_gen() update max=%d from %d", g, _2_node_idx_t(di._key));
5119       }
5120 #endif
5121     }
5122   }
5123   return g;
5124 }
5125 
5126 void CloneMap::dump(node_idx_t key, outputStream* st) const {
5127   uint64_t val = value(key);
5128   if (val != 0) {
5129     NodeCloneInfo ni(val);
5130     ni.dump_on(st);
5131   }
5132 }
5133 
5134 void Compile::shuffle_macro_nodes() {
5135   if (_macro_nodes.length() < 2) {
5136     return;
5137   }
5138   for (uint i = _macro_nodes.length() - 1; i >= 1; i--) {
5139     uint j = C->random() % (i + 1);
5140     swap(_macro_nodes.at(i), _macro_nodes.at(j));
5141   }
5142 }
5143 
5144 // Move Allocate nodes to the start of the list
5145 void Compile::sort_macro_nodes() {
5146   int count = macro_count();
5147   int allocates = 0;
5148   for (int i = 0; i < count; i++) {
5149     Node* n = macro_node(i);
5150     if (n->is_Allocate()) {
5151       if (i != allocates) {
5152         Node* tmp = macro_node(allocates);
5153         _macro_nodes.at_put(allocates, n);
5154         _macro_nodes.at_put(i, tmp);
5155       }
5156       allocates++;
5157     }
5158   }
5159 }
5160 
5161 void Compile::print_method(CompilerPhaseType cpt, int level, Node* n) {
5162   if (failing_internal()) { return; } // failing_internal to not stress bailouts from printing code.
5163   EventCompilerPhase event(UNTIMED);
5164   if (event.should_commit()) {
5165     CompilerEvent::PhaseEvent::post(event, C->_latest_stage_start_counter, cpt, C->_compile_id, level);
5166   }
5167 #ifndef PRODUCT
5168   ResourceMark rm;
5169   stringStream ss;
5170   ss.print_raw(CompilerPhaseTypeHelper::to_description(cpt));
5171   int iter = ++_igv_phase_iter[cpt];
5172   if (iter > 1) {
5173     ss.print(" %d", iter);
5174   }
5175   if (n != nullptr) {
5176     ss.print(": %d %s", n->_idx, NodeClassNames[n->Opcode()]);
5177     if (n->is_Call()) {
5178       CallNode* call = n->as_Call();
5179       if (call->_name != nullptr) {
5180         // E.g. uncommon traps etc.
5181         ss.print(" - %s", call->_name);
5182       } else if (call->is_CallJava()) {
5183         CallJavaNode* call_java = call->as_CallJava();
5184         if (call_java->method() != nullptr) {
5185           ss.print(" -");
5186           call_java->method()->print_short_name(&ss);
5187         }
5188       }
5189     }
5190   }
5191 
5192   const char* name = ss.as_string();
5193   if (should_print_igv(level)) {
5194     _igv_printer->print_graph(name);
5195   }
5196   if (should_print_phase(level)) {
5197     print_phase(name);
5198   }
5199   if (should_print_ideal_phase(cpt)) {
5200     print_ideal_ir(CompilerPhaseTypeHelper::to_name(cpt));
5201   }
5202 #endif
5203   C->_latest_stage_start_counter.stamp();
5204 }
5205 
5206 // Only used from CompileWrapper
5207 void Compile::begin_method() {
5208 #ifndef PRODUCT
5209   if (_method != nullptr && should_print_igv(1)) {
5210     _igv_printer->begin_method();
5211   }
5212 #endif
5213   C->_latest_stage_start_counter.stamp();
5214 }
5215 
5216 // Only used from CompileWrapper
5217 void Compile::end_method() {
5218   EventCompilerPhase event(UNTIMED);
5219   if (event.should_commit()) {
5220     CompilerEvent::PhaseEvent::post(event, C->_latest_stage_start_counter, PHASE_END, C->_compile_id, 1);
5221   }
5222 
5223 #ifndef PRODUCT
5224   if (_method != nullptr && should_print_igv(1)) {
5225     _igv_printer->end_method();
5226   }
5227 #endif
5228 }
5229 
5230 #ifndef PRODUCT
5231 bool Compile::should_print_phase(const int level) const {
5232   return PrintPhaseLevel >= 0 && directive()->PhasePrintLevelOption >= level &&
5233          _method != nullptr; // Do not print phases for stubs.
5234 }
5235 
5236 bool Compile::should_print_ideal_phase(CompilerPhaseType cpt) const {
5237   return _directive->should_print_ideal_phase(cpt);
5238 }
5239 
5240 void Compile::init_igv() {
5241   if (_igv_printer == nullptr) {
5242     _igv_printer = IdealGraphPrinter::printer();
5243     _igv_printer->set_compile(this);
5244   }
5245 }
5246 
5247 bool Compile::should_print_igv(const int level) {
5248   PRODUCT_RETURN_(return false;);
5249 
5250   if (PrintIdealGraphLevel < 0) { // disabled by the user
5251     return false;
5252   }
5253 
5254   bool need = directive()->IGVPrintLevelOption >= level;
5255   if (need) {
5256     Compile::init_igv();
5257   }
5258   return need;
5259 }
5260 
5261 IdealGraphPrinter* Compile::_debug_file_printer = nullptr;
5262 IdealGraphPrinter* Compile::_debug_network_printer = nullptr;
5263 
5264 // Called from debugger. Prints method to the default file with the default phase name.
5265 // This works regardless of any Ideal Graph Visualizer flags set or not.
5266 // Use in debugger (gdb/rr): p igv_print($sp, $fp, $pc).
5267 void igv_print(void* sp, void* fp, void* pc) {
5268   frame fr(sp, fp, pc);
5269   Compile::current()->igv_print_method_to_file(nullptr, false, &fr);
5270 }
5271 
5272 // Same as igv_print() above but with a specified phase name.
5273 void igv_print(const char* phase_name, void* sp, void* fp, void* pc) {
5274   frame fr(sp, fp, pc);
5275   Compile::current()->igv_print_method_to_file(phase_name, false, &fr);
5276 }
5277 
5278 // Called from debugger. Prints method with the default phase name to the default network or the one specified with
5279 // the network flags for the Ideal Graph Visualizer, or to the default file depending on the 'network' argument.
5280 // This works regardless of any Ideal Graph Visualizer flags set or not.
5281 // Use in debugger (gdb/rr): p igv_print(true, $sp, $fp, $pc).
5282 void igv_print(bool network, void* sp, void* fp, void* pc) {
5283   frame fr(sp, fp, pc);
5284   if (network) {
5285     Compile::current()->igv_print_method_to_network(nullptr, &fr);
5286   } else {
5287     Compile::current()->igv_print_method_to_file(nullptr, false, &fr);
5288   }
5289 }
5290 
5291 // Same as igv_print(bool network, ...) above but with a specified phase name.
5292 // Use in debugger (gdb/rr): p igv_print(true, "MyPhase", $sp, $fp, $pc).
5293 void igv_print(bool network, const char* phase_name, void* sp, void* fp, void* pc) {
5294   frame fr(sp, fp, pc);
5295   if (network) {
5296     Compile::current()->igv_print_method_to_network(phase_name, &fr);
5297   } else {
5298     Compile::current()->igv_print_method_to_file(phase_name, false, &fr);
5299   }
5300 }
5301 
5302 // Called from debugger. Normal write to the default _printer. Only works if Ideal Graph Visualizer printing flags are set.
5303 void igv_print_default() {
5304   Compile::current()->print_method(PHASE_DEBUG, 0);
5305 }
5306 
5307 // Called from debugger, especially when replaying a trace in which the program state cannot be altered like with rr replay.
5308 // A method is appended to an existing default file with the default phase name. This means that igv_append() must follow
5309 // an earlier igv_print(*) call which sets up the file. This works regardless of any Ideal Graph Visualizer flags set or not.
5310 // Use in debugger (gdb/rr): p igv_append($sp, $fp, $pc).
5311 void igv_append(void* sp, void* fp, void* pc) {
5312   frame fr(sp, fp, pc);
5313   Compile::current()->igv_print_method_to_file(nullptr, true, &fr);
5314 }
5315 
5316 // Same as igv_append(...) above but with a specified phase name.
5317 // Use in debugger (gdb/rr): p igv_append("MyPhase", $sp, $fp, $pc).
5318 void igv_append(const char* phase_name, void* sp, void* fp, void* pc) {
5319   frame fr(sp, fp, pc);
5320   Compile::current()->igv_print_method_to_file(phase_name, true, &fr);
5321 }
5322 
5323 void Compile::igv_print_method_to_file(const char* phase_name, bool append, const frame* fr) {
5324   const char* file_name = "custom_debug.xml";
5325   if (_debug_file_printer == nullptr) {
5326     _debug_file_printer = new IdealGraphPrinter(C, file_name, append);
5327   } else {
5328     _debug_file_printer->update_compiled_method(C->method());
5329   }
5330   tty->print_cr("Method %s to %s", append ? "appended" : "printed", file_name);
5331   _debug_file_printer->print_graph(phase_name, fr);
5332 }
5333 
5334 void Compile::igv_print_method_to_network(const char* phase_name, const frame* fr) {
5335   ResourceMark rm;
5336   GrowableArray<const Node*> empty_list;
5337   igv_print_graph_to_network(phase_name, empty_list, fr);
5338 }
5339 
5340 void Compile::igv_print_graph_to_network(const char* name, GrowableArray<const Node*>& visible_nodes, const frame* fr) {
5341   if (_debug_network_printer == nullptr) {
5342     _debug_network_printer = new IdealGraphPrinter(C);
5343   } else {
5344     _debug_network_printer->update_compiled_method(C->method());
5345   }
5346   tty->print_cr("Method printed over network stream to IGV");
5347   _debug_network_printer->print(name, C->root(), visible_nodes, fr);
5348 }
5349 #endif // !PRODUCT
5350 
5351 Node* Compile::narrow_value(BasicType bt, Node* value, const Type* type, PhaseGVN* phase, bool transform_res) {
5352   if (type != nullptr && phase->type(value)->higher_equal(type)) {
5353     return value;
5354   }
5355   Node* result = nullptr;
5356   if (bt == T_BYTE) {
5357     result = phase->transform(new LShiftINode(value, phase->intcon(24)));
5358     result = new RShiftINode(result, phase->intcon(24));
5359   } else if (bt == T_BOOLEAN) {
5360     result = new AndINode(value, phase->intcon(0xFF));
5361   } else if (bt == T_CHAR) {
5362     result = new AndINode(value,phase->intcon(0xFFFF));
5363   } else {
5364     assert(bt == T_SHORT, "unexpected narrow type");
5365     result = phase->transform(new LShiftINode(value, phase->intcon(16)));
5366     result = new RShiftINode(result, phase->intcon(16));
5367   }
5368   if (transform_res) {
5369     result = phase->transform(result);
5370   }
5371   return result;
5372 }
5373 
5374 void Compile::record_method_not_compilable_oom() {
5375   record_method_not_compilable(CompilationMemoryStatistic::failure_reason_memlimit());
5376 }
5377 
5378 #ifndef PRODUCT
5379 // Collects all the control inputs from nodes on the worklist and from their data dependencies
5380 static void find_candidate_control_inputs(Unique_Node_List& worklist, Unique_Node_List& candidates) {
5381   // Follow non-control edges until we reach CFG nodes
5382   for (uint i = 0; i < worklist.size(); i++) {
5383     const Node* n = worklist.at(i);
5384     for (uint j = 0; j < n->req(); j++) {
5385       Node* in = n->in(j);
5386       if (in == nullptr || in->is_Root()) {
5387         continue;
5388       }
5389       if (in->is_CFG()) {
5390         if (in->is_Call()) {
5391           // The return value of a call is only available if the call did not result in an exception
5392           Node* control_proj_use = in->as_Call()->proj_out(TypeFunc::Control)->unique_out();
5393           if (control_proj_use->is_Catch()) {
5394             Node* fall_through = control_proj_use->as_Catch()->proj_out(CatchProjNode::fall_through_index);
5395             candidates.push(fall_through);
5396             continue;
5397           }
5398         }
5399 
5400         if (in->is_Multi()) {
5401           // We got here by following data inputs so we should only have one control use
5402           // (no IfNode, etc)
5403           assert(!n->is_MultiBranch(), "unexpected node type: %s", n->Name());
5404           candidates.push(in->as_Multi()->proj_out(TypeFunc::Control));
5405         } else {
5406           candidates.push(in);
5407         }
5408       } else {
5409         worklist.push(in);
5410       }
5411     }
5412   }
5413 }
5414 
5415 // Returns the candidate node that is a descendant to all the other candidates
5416 static Node* pick_control(Unique_Node_List& candidates) {
5417   Unique_Node_List worklist;
5418   worklist.copy(candidates);
5419 
5420   // Traverse backwards through the CFG
5421   for (uint i = 0; i < worklist.size(); i++) {
5422     const Node* n = worklist.at(i);
5423     if (n->is_Root()) {
5424       continue;
5425     }
5426     for (uint j = 0; j < n->req(); j++) {
5427       // Skip backedge of loops to avoid cycles
5428       if (n->is_Loop() && j == LoopNode::LoopBackControl) {
5429         continue;
5430       }
5431 
5432       Node* pred = n->in(j);
5433       if (pred != nullptr && pred != n && pred->is_CFG()) {
5434         worklist.push(pred);
5435         // if pred is an ancestor of n, then pred is an ancestor to at least one candidate
5436         candidates.remove(pred);
5437       }
5438     }
5439   }
5440 
5441   assert(candidates.size() == 1, "unexpected control flow");
5442   return candidates.at(0);
5443 }
5444 
5445 // Initialize a parameter input for a debug print call, using a placeholder for jlong and jdouble
5446 static void debug_print_init_parm(Node* call, Node* parm, Node* half, int* pos) {
5447   call->init_req((*pos)++, parm);
5448   const BasicType bt = parm->bottom_type()->basic_type();
5449   if (bt == T_LONG || bt == T_DOUBLE) {
5450     call->init_req((*pos)++, half);
5451   }
5452 }
5453 
5454 Node* Compile::make_debug_print_call(const char* str, address call_addr, PhaseGVN* gvn,
5455                               Node* parm0, Node* parm1,
5456                               Node* parm2, Node* parm3,
5457                               Node* parm4, Node* parm5,
5458                               Node* parm6) const {
5459   Node* str_node = gvn->transform(new ConPNode(TypeRawPtr::make(((address) str))));
5460   const TypeFunc* type = OptoRuntime::debug_print_Type(parm0, parm1, parm2, parm3, parm4, parm5, parm6);
5461   Node* call = new CallLeafNode(type, call_addr, "debug_print", TypeRawPtr::BOTTOM);
5462 
5463   // find the most suitable control input
5464   Unique_Node_List worklist, candidates;
5465   if (parm0 != nullptr) { worklist.push(parm0);
5466   if (parm1 != nullptr) { worklist.push(parm1);
5467   if (parm2 != nullptr) { worklist.push(parm2);
5468   if (parm3 != nullptr) { worklist.push(parm3);
5469   if (parm4 != nullptr) { worklist.push(parm4);
5470   if (parm5 != nullptr) { worklist.push(parm5);
5471   if (parm6 != nullptr) { worklist.push(parm6);
5472   /* close each nested if ===> */  } } } } } } }
5473   find_candidate_control_inputs(worklist, candidates);
5474   Node* control = nullptr;
5475   if (candidates.size() == 0) {
5476     control = C->start()->proj_out(TypeFunc::Control);
5477   } else {
5478     control = pick_control(candidates);
5479   }
5480 
5481   // find all the previous users of the control we picked
5482   GrowableArray<Node*> users_of_control;
5483   for (DUIterator_Fast kmax, i = control->fast_outs(kmax); i < kmax; i++) {
5484     Node* use = control->fast_out(i);
5485     if (use->is_CFG() && use != control) {
5486       users_of_control.push(use);
5487     }
5488   }
5489 
5490   // we do not actually care about IO and memory as it uses neither
5491   call->init_req(TypeFunc::Control,   control);
5492   call->init_req(TypeFunc::I_O,       top());
5493   call->init_req(TypeFunc::Memory,    top());
5494   call->init_req(TypeFunc::FramePtr,  C->start()->proj_out(TypeFunc::FramePtr));
5495   call->init_req(TypeFunc::ReturnAdr, top());
5496 
5497   int pos = TypeFunc::Parms;
5498   call->init_req(pos++, str_node);
5499   if (parm0 != nullptr) { debug_print_init_parm(call, parm0, top(), &pos);
5500   if (parm1 != nullptr) { debug_print_init_parm(call, parm1, top(), &pos);
5501   if (parm2 != nullptr) { debug_print_init_parm(call, parm2, top(), &pos);
5502   if (parm3 != nullptr) { debug_print_init_parm(call, parm3, top(), &pos);
5503   if (parm4 != nullptr) { debug_print_init_parm(call, parm4, top(), &pos);
5504   if (parm5 != nullptr) { debug_print_init_parm(call, parm5, top(), &pos);
5505   if (parm6 != nullptr) { debug_print_init_parm(call, parm6, top(), &pos);
5506   /* close each nested if ===> */  } } } } } } }
5507   assert(call->in(call->req()-1) != nullptr, "must initialize all parms");
5508 
5509   call = gvn->transform(call);
5510   Node* call_control_proj = gvn->transform(new ProjNode(call, TypeFunc::Control));
5511 
5512   // rewire previous users to have the new call as control instead
5513   PhaseIterGVN* igvn = gvn->is_IterGVN();
5514   for (int i = 0; i < users_of_control.length(); i++) {
5515     Node* use = users_of_control.at(i);
5516     for (uint j = 0; j < use->req(); j++) {
5517       if (use->in(j) == control) {
5518         if (igvn != nullptr) {
5519           igvn->replace_input_of(use, j, call_control_proj);
5520         } else {
5521           gvn->hash_delete(use);
5522           use->set_req(j, call_control_proj);
5523           gvn->hash_insert(use);
5524         }
5525       }
5526     }
5527   }
5528 
5529   return call;
5530 }
5531 #endif // !PRODUCT