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   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 422   bs->unregister_potential_barrier_node(dead);
 423 }
 424 
 425 // Disconnect all useless nodes by disconnecting those at the boundary.
 426 void Compile::disconnect_useless_nodes(Unique_Node_List& useful, Unique_Node_List& worklist, const Unique_Node_List* root_and_safepoints) {
 427   uint next = 0;
 428   while (next < useful.size()) {
 429     Node *n = useful.at(next++);
 430     if (n->is_SafePoint()) {
 431       // We're done with a parsing phase. Replaced nodes are not valid
 432       // beyond that point.
 433       n->as_SafePoint()->delete_replaced_nodes();
 434     }
 435     // Use raw traversal of out edges since this code removes out edges
 436     int max = n->outcnt();
 437     for (int j = 0; j < max; ++j) {
 438       Node* child = n->raw_out(j);
 439       if (!useful.member(child)) {
 440         assert(!child->is_top() || child != top(),
 441                "If top is cached in Compile object it is in useful list");
 442         // Only need to remove this out-edge to the useless node
 443         n->raw_del_out(j);
 444         --j;
 445         --max;
 446         if (child->is_data_proj_of_pure_function(n)) {
 447           worklist.push(n);
 448         }
 449       }
 450     }
 451     if (n->outcnt() == 1 && n->has_special_unique_user()) {
 452       assert(useful.member(n->unique_out()), "do not push a useless node");
 453       worklist.push(n->unique_out());
 454     }
 455   }
 456 
 457   remove_useless_nodes(_macro_nodes,        useful); // remove useless macro nodes
 458   remove_useless_nodes(_parse_predicates,   useful); // remove useless Parse Predicate nodes
 459   // Remove useless Template Assertion Predicate opaque nodes
 460   remove_useless_nodes(_template_assertion_predicate_opaques, useful);
 461   remove_useless_nodes(_expensive_nodes,    useful); // remove useless expensive nodes
 462   remove_useless_nodes(_for_post_loop_igvn, useful); // remove useless node recorded for post loop opts IGVN pass
 463   remove_useless_nodes(_for_merge_stores_igvn, useful); // remove useless node recorded for merge stores IGVN pass
 464   remove_useless_unstable_if_traps(useful);          // remove useless unstable_if traps
 465   remove_useless_coarsened_locks(useful);            // remove useless coarsened locks nodes
 466 #ifdef ASSERT
 467   if (_modified_nodes != nullptr) {
 468     _modified_nodes->remove_useless_nodes(useful.member_set());
 469   }
 470 #endif
 471 
 472   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 473   bs->eliminate_useless_gc_barriers(useful, this);
 474   // clean up the late inline lists
 475   remove_useless_late_inlines(                &_late_inlines, useful);
 476   remove_useless_late_inlines(         &_string_late_inlines, useful);
 477   remove_useless_late_inlines(         &_boxing_late_inlines, useful);
 478   remove_useless_late_inlines(&_vector_reboxing_late_inlines, useful);
 479   DEBUG_ONLY(verify_graph_edges(true /*check for no_dead_code*/, root_and_safepoints);)
 480 }
 481 
 482 // ============================================================================
 483 //------------------------------CompileWrapper---------------------------------
 484 class CompileWrapper : public StackObj {
 485   Compile *const _compile;
 486  public:
 487   CompileWrapper(Compile* compile);
 488 
 489   ~CompileWrapper();
 490 };
 491 
 492 CompileWrapper::CompileWrapper(Compile* compile) : _compile(compile) {
 493   // the Compile* pointer is stored in the current ciEnv:
 494   ciEnv* env = compile->env();
 495   assert(env == ciEnv::current(), "must already be a ciEnv active");
 496   assert(env->compiler_data() == nullptr, "compile already active?");
 497   env->set_compiler_data(compile);
 498   assert(compile == Compile::current(), "sanity");
 499 
 500   compile->set_type_dict(nullptr);
 501   compile->set_clone_map(new Dict(cmpkey, hashkey, _compile->comp_arena()));
 502   compile->clone_map().set_clone_idx(0);
 503   compile->set_type_last_size(0);
 504   compile->set_last_tf(nullptr, nullptr);
 505   compile->set_indexSet_arena(nullptr);
 506   compile->set_indexSet_free_block_list(nullptr);
 507   compile->init_type_arena();
 508   Type::Initialize(compile);
 509   _compile->begin_method();
 510   _compile->clone_map().set_debug(_compile->has_method() && _compile->directive()->CloneMapDebugOption);
 511 }
 512 CompileWrapper::~CompileWrapper() {
 513   // simulate crash during compilation
 514   assert(CICrashAt < 0 || _compile->compile_id() != CICrashAt, "just as planned");
 515 
 516   _compile->end_method();
 517   _compile->env()->set_compiler_data(nullptr);
 518 }
 519 
 520 
 521 //----------------------------print_compile_messages---------------------------
 522 void Compile::print_compile_messages() {
 523 #ifndef PRODUCT
 524   // Check if recompiling
 525   if (!subsume_loads() && PrintOpto) {
 526     // Recompiling without allowing machine instructions to subsume loads
 527     tty->print_cr("*********************************************************");
 528     tty->print_cr("** Bailout: Recompile without subsuming loads          **");
 529     tty->print_cr("*********************************************************");
 530   }
 531   if ((do_escape_analysis() != DoEscapeAnalysis) && PrintOpto) {
 532     // Recompiling without escape analysis
 533     tty->print_cr("*********************************************************");
 534     tty->print_cr("** Bailout: Recompile without escape analysis          **");
 535     tty->print_cr("*********************************************************");
 536   }
 537   if (do_iterative_escape_analysis() != DoEscapeAnalysis && PrintOpto) {
 538     // Recompiling without iterative escape analysis
 539     tty->print_cr("*********************************************************");
 540     tty->print_cr("** Bailout: Recompile without iterative escape analysis**");
 541     tty->print_cr("*********************************************************");
 542   }
 543   if (do_reduce_allocation_merges() != ReduceAllocationMerges && PrintOpto) {
 544     // Recompiling without reducing allocation merges
 545     tty->print_cr("*********************************************************");
 546     tty->print_cr("** Bailout: Recompile without reduce allocation merges **");
 547     tty->print_cr("*********************************************************");
 548   }
 549   if ((eliminate_boxing() != EliminateAutoBox) && PrintOpto) {
 550     // Recompiling without boxing elimination
 551     tty->print_cr("*********************************************************");
 552     tty->print_cr("** Bailout: Recompile without boxing elimination       **");
 553     tty->print_cr("*********************************************************");
 554   }
 555   if ((do_locks_coarsening() != EliminateLocks) && PrintOpto) {
 556     // Recompiling without locks coarsening
 557     tty->print_cr("*********************************************************");
 558     tty->print_cr("** Bailout: Recompile without locks coarsening         **");
 559     tty->print_cr("*********************************************************");
 560   }
 561   if (env()->break_at_compile()) {
 562     // Open the debugger when compiling this method.
 563     tty->print("### Breaking when compiling: ");
 564     method()->print_short_name();
 565     tty->cr();
 566     BREAKPOINT;
 567   }
 568 
 569   if( PrintOpto ) {
 570     if (is_osr_compilation()) {
 571       tty->print("[OSR]");
 572     } else if (env()->task()->is_precompile()) {
 573       if (for_preload()) {
 574         tty->print("[PRE]");
 575       } else {
 576         tty->print("[AOT]");
 577       }
 578     }
 579     tty->print("%3d", _compile_id);
 580   }
 581 #endif
 582 }
 583 
 584 #ifndef PRODUCT
 585 void Compile::print_phase(const char* phase_name) {
 586   tty->print_cr("%u.\t%s", ++_phase_counter, phase_name);
 587 }
 588 
 589 void Compile::print_ideal_ir(const char* phase_name) {
 590   // keep the following output all in one block
 591   // This output goes directly to the tty, not the compiler log.
 592   // To enable tools to match it up with the compilation activity,
 593   // be sure to tag this tty output with the compile ID.
 594 
 595   // Node dumping can cause a safepoint, which can break the tty lock.
 596   // Buffer all node dumps, so that all safepoints happen before we lock.
 597   ResourceMark rm;
 598   stringStream ss;
 599 
 600   if (_output == nullptr) {
 601     ss.print_cr("AFTER: %s", phase_name);
 602     // Print out all nodes in ascending order of index.
 603     root()->dump_bfs(MaxNodeLimit, nullptr, "+S$", &ss);
 604   } else {
 605     // Dump the node blockwise if we have a scheduling
 606     _output->print_scheduling(&ss);
 607   }
 608 
 609   // Check that the lock is not broken by a safepoint.
 610   NoSafepointVerifier nsv;
 611   ttyLocker ttyl;
 612   if (xtty != nullptr) {
 613     xtty->head("ideal compile_id='%d'%s compile_phase='%s'",
 614                compile_id(),
 615                is_osr_compilation() ? " compile_kind='osr'" :
 616                (for_preload() ? " compile_kind='AP'" : ""),
 617                phase_name);
 618   }
 619 
 620   tty->print("%s", ss.as_string());
 621 
 622   if (xtty != nullptr) {
 623     xtty->tail("ideal");
 624   }
 625 }
 626 #endif
 627 
 628 // ============================================================================
 629 //------------------------------Compile standard-------------------------------
 630 
 631 // Compile a method.  entry_bci is -1 for normal compilations and indicates
 632 // the continuation bci for on stack replacement.
 633 
 634 
 635 Compile::Compile(ciEnv* ci_env, ciMethod* target, int osr_bci,
 636                  Options options, DirectiveSet* directive)
 637     : Phase(Compiler),
 638       _compile_id(ci_env->compile_id()),
 639       _options(options),
 640       _method(target),
 641       _entry_bci(osr_bci),
 642       _ilt(nullptr),
 643       _stub_function(nullptr),
 644       _stub_name(nullptr),
 645       _stub_id(StubId::NO_STUBID),
 646       _stub_entry_point(nullptr),
 647       _max_node_limit(MaxNodeLimit),
 648       _post_loop_opts_phase(false),
 649       _merge_stores_phase(false),
 650       _allow_macro_nodes(true),
 651       _inlining_progress(false),
 652       _inlining_incrementally(false),
 653       _do_cleanup(false),
 654       _has_reserved_stack_access(target->has_reserved_stack_access()),
 655 #ifndef PRODUCT
 656       _igv_idx(0),
 657       _trace_opto_output(directive->TraceOptoOutputOption),
 658 #endif
 659       _clinit_barrier_on_entry(false),
 660       _has_clinit_barriers(false),
 661       _stress_seed(0),
 662       _comp_arena(mtCompiler, Arena::Tag::tag_comp),
 663       _barrier_set_state(BarrierSet::barrier_set()->barrier_set_c2()->create_barrier_state(comp_arena())),
 664       _env(ci_env),
 665       _directive(directive),
 666       _log(ci_env->log()),
 667       _first_failure_details(nullptr),
 668       _intrinsics(comp_arena(), 0, 0, nullptr),
 669       _macro_nodes(comp_arena(), 8, 0, nullptr),
 670       _parse_predicates(comp_arena(), 8, 0, nullptr),
 671       _template_assertion_predicate_opaques(comp_arena(), 8, 0, nullptr),
 672       _expensive_nodes(comp_arena(), 8, 0, nullptr),
 673       _for_post_loop_igvn(comp_arena(), 8, 0, nullptr),
 674       _for_merge_stores_igvn(comp_arena(), 8, 0, nullptr),
 675       _unstable_if_traps(comp_arena(), 8, 0, nullptr),
 676       _coarsened_locks(comp_arena(), 8, 0, nullptr),
 677       _congraph(nullptr),
 678       NOT_PRODUCT(_igv_printer(nullptr) COMMA)
 679           _unique(0),
 680       _dead_node_count(0),
 681       _dead_node_list(comp_arena()),
 682       _node_arena_one(mtCompiler, Arena::Tag::tag_node),
 683       _node_arena_two(mtCompiler, Arena::Tag::tag_node),
 684       _node_arena(&_node_arena_one),
 685       _mach_constant_base_node(nullptr),
 686       _Compile_types(mtCompiler, Arena::Tag::tag_type),
 687       _initial_gvn(nullptr),
 688       _igvn_worklist(nullptr),
 689       _types(nullptr),
 690       _node_hash(nullptr),
 691       _late_inlines(comp_arena(), 2, 0, nullptr),
 692       _string_late_inlines(comp_arena(), 2, 0, nullptr),
 693       _boxing_late_inlines(comp_arena(), 2, 0, nullptr),
 694       _vector_reboxing_late_inlines(comp_arena(), 2, 0, nullptr),
 695       _late_inlines_pos(0),
 696       _number_of_mh_late_inlines(0),
 697       _oom(false),
 698       _replay_inline_data(nullptr),
 699       _inline_printer(this),
 700       _java_calls(0),
 701       _inner_loops(0),
 702       _FIRST_STACK_mask(comp_arena()),
 703       _interpreter_frame_size(0),
 704       _regmask_arena(mtCompiler, Arena::Tag::tag_regmask),
 705       _output(nullptr)
 706 #ifndef PRODUCT
 707       ,
 708       _in_dump_cnt(0)
 709 #endif
 710 {
 711   C = this;
 712   CompileWrapper cw(this);
 713 
 714   TraceTime t1("Total compilation time", &_t_totalCompilation, CITime, CITimeVerbose);
 715   TraceTime t2(nullptr, &_t_methodCompilation, CITime, false);
 716 
 717 #if defined(SUPPORT_ASSEMBLY) || defined(SUPPORT_ABSTRACT_ASSEMBLY)
 718   bool print_opto_assembly = directive->PrintOptoAssemblyOption;
 719   // We can always print a disassembly, either abstract (hex dump) or
 720   // with the help of a suitable hsdis library. Thus, we should not
 721   // couple print_assembly and print_opto_assembly controls.
 722   // But: always print opto and regular assembly on compile command 'print'.
 723   bool print_assembly = directive->PrintAssemblyOption;
 724   set_print_assembly(print_opto_assembly || print_assembly);
 725 #else
 726   set_print_assembly(false); // must initialize.
 727 #endif
 728 
 729 #ifndef PRODUCT
 730   set_parsed_irreducible_loop(false);
 731 #endif
 732 
 733   if (directive->ReplayInlineOption) {
 734     _replay_inline_data = ciReplay::load_inline_data(method(), entry_bci(), ci_env->comp_level());
 735   }
 736   set_print_inlining(directive->PrintInliningOption || PrintOptoInlining);
 737   set_print_intrinsics(directive->PrintIntrinsicsOption);
 738   set_has_irreducible_loop(true); // conservative until build_loop_tree() reset it
 739 
 740   if (ProfileTraps) {
 741     // Make sure the method being compiled gets its own MDO,
 742     // so we can at least track the decompile_count().
 743     method()->ensure_method_data();
 744   }
 745 
 746   if (StressLCM || StressGCM || StressIGVN || StressCCP ||
 747       StressIncrementalInlining || StressMacroExpansion ||
 748       StressMacroElimination || StressUnstableIfTraps ||
 749       StressBailout || StressLoopPeeling) {
 750     initialize_stress_seed(directive);
 751   }
 752 
 753   Init(/*do_aliasing=*/ true);
 754 
 755   print_compile_messages();
 756 
 757   _ilt = InlineTree::build_inline_tree_root();
 758 
 759   // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
 760   assert(num_alias_types() >= AliasIdxRaw, "");
 761 
 762 #define MINIMUM_NODE_HASH  1023
 763 
 764   // GVN that will be run immediately on new nodes
 765   uint estimated_size = method()->code_size()*4+64;
 766   estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
 767   _igvn_worklist = new (comp_arena()) Unique_Node_List(comp_arena());
 768   _types = new (comp_arena()) Type_Array(comp_arena());
 769   _node_hash = new (comp_arena()) NodeHash(comp_arena(), estimated_size);
 770   PhaseGVN gvn;
 771   set_initial_gvn(&gvn);
 772 
 773   { // Scope for timing the parser
 774     TracePhase tp(_t_parser);
 775 
 776     // Put top into the hash table ASAP.
 777     initial_gvn()->transform(top());
 778 
 779     // Set up tf(), start(), and find a CallGenerator.
 780     CallGenerator* cg = nullptr;
 781     if (is_osr_compilation()) {
 782       const TypeTuple *domain = StartOSRNode::osr_domain();
 783       const TypeTuple *range = TypeTuple::make_range(method()->signature());
 784       init_tf(TypeFunc::make(domain, range));
 785       StartNode* s = new StartOSRNode(root(), domain);
 786       initial_gvn()->set_type_bottom(s);
 787       verify_start(s);
 788       cg = CallGenerator::for_osr(method(), entry_bci());
 789     } else {
 790       // Normal case.
 791       init_tf(TypeFunc::make(method()));
 792       StartNode* s = new StartNode(root(), tf()->domain());
 793       initial_gvn()->set_type_bottom(s);
 794       verify_start(s);
 795       float past_uses = method()->interpreter_invocation_count();
 796       float expected_uses = past_uses;
 797       cg = CallGenerator::for_inline(method(), expected_uses);
 798     }
 799     if (failing())  return;
 800     if (cg == nullptr) {
 801       const char* reason = InlineTree::check_can_parse(method());
 802       assert(reason != nullptr, "expect reason for parse failure");
 803       stringStream ss;
 804       ss.print("cannot parse method: %s", reason);
 805       record_method_not_compilable(ss.as_string());
 806       return;
 807     }
 808 
 809     gvn.set_type(root(), root()->bottom_type());
 810 
 811     JVMState* jvms = build_start_state(start(), tf());
 812     if ((jvms = cg->generate(jvms)) == nullptr) {
 813       assert(failure_reason() != nullptr, "expect reason for parse failure");
 814       stringStream ss;
 815       ss.print("method parse failed: %s", failure_reason());
 816       record_method_not_compilable(ss.as_string() DEBUG_ONLY(COMMA true));
 817       return;
 818     }
 819     GraphKit kit(jvms);
 820 
 821     if (!kit.stopped()) {
 822       // Accept return values, and transfer control we know not where.
 823       // This is done by a special, unique ReturnNode bound to root.
 824       return_values(kit.jvms());
 825     }
 826 
 827     if (kit.has_exceptions()) {
 828       // Any exceptions that escape from this call must be rethrown
 829       // to whatever caller is dynamically above us on the stack.
 830       // This is done by a special, unique RethrowNode bound to root.
 831       rethrow_exceptions(kit.transfer_exceptions_into_jvms());
 832     }
 833 
 834     assert(IncrementalInline || (_late_inlines.length() == 0 && !has_mh_late_inlines()), "incremental inlining is off");
 835 
 836     if (_late_inlines.length() == 0 && !has_mh_late_inlines() && !failing() && has_stringbuilder()) {
 837       inline_string_calls(true);
 838     }
 839 
 840     if (failing())  return;
 841 
 842     // Remove clutter produced by parsing.
 843     if (!failing()) {
 844       ResourceMark rm;
 845       PhaseRemoveUseless pru(initial_gvn(), *igvn_worklist());
 846     }
 847   }
 848 
 849   // Note:  Large methods are capped off in do_one_bytecode().
 850   if (failing())  return;
 851 
 852   // After parsing, node notes are no longer automagic.
 853   // They must be propagated by register_new_node_with_optimizer(),
 854   // clone(), or the like.
 855   set_default_node_notes(nullptr);
 856 
 857 #ifndef PRODUCT
 858   if (should_print_igv(1)) {
 859     _igv_printer->print_inlining();
 860   }
 861 #endif
 862 
 863   if (failing())  return;
 864   NOT_PRODUCT( verify_graph_edges(); )
 865 
 866   // Now optimize
 867   Optimize();
 868   if (failing())  return;
 869   NOT_PRODUCT( verify_graph_edges(); )
 870 
 871 #ifndef PRODUCT
 872   if (should_print_ideal()) {
 873     print_ideal_ir("print_ideal");
 874   }
 875 #endif
 876 
 877 #ifdef ASSERT
 878   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 879   bs->verify_gc_barriers(this, BarrierSetC2::BeforeCodeGen);
 880 #endif
 881 
 882   // Dump compilation data to replay it.
 883   if (directive->DumpReplayOption) {
 884     env()->dump_replay_data(_compile_id);
 885   }
 886   if (directive->DumpInlineOption && (ilt() != nullptr)) {
 887     env()->dump_inline_data(_compile_id);
 888   }
 889 
 890   // Now that we know the size of all the monitors we can add a fixed slot
 891   // for the original deopt pc.
 892   int next_slot = fixed_slots() + (sizeof(address) / VMRegImpl::stack_slot_size);
 893   set_fixed_slots(next_slot);
 894 
 895   // Compute when to use implicit null checks. Used by matching trap based
 896   // nodes and NullCheck optimization.
 897   set_allowed_deopt_reasons();
 898 
 899   // Now generate code
 900   Code_Gen();
 901 }
 902 
 903 //------------------------------Compile----------------------------------------
 904 // Compile a runtime stub
 905 Compile::Compile(ciEnv* ci_env,
 906                  TypeFunc_generator generator,
 907                  address stub_function,
 908                  const char* stub_name,
 909                  StubId stub_id,
 910                  int is_fancy_jump,
 911                  bool pass_tls,
 912                  bool return_pc,
 913                  DirectiveSet* directive)
 914     : Phase(Compiler),
 915       _compile_id(0),
 916       _options(Options::for_runtime_stub()),
 917       _method(nullptr),
 918       _entry_bci(InvocationEntryBci),
 919       _stub_function(stub_function),
 920       _stub_name(stub_name),
 921       _stub_id(stub_id),
 922       _stub_entry_point(nullptr),
 923       _max_node_limit(MaxNodeLimit),
 924       _post_loop_opts_phase(false),
 925       _merge_stores_phase(false),
 926       _allow_macro_nodes(true),
 927       _inlining_progress(false),
 928       _inlining_incrementally(false),
 929       _has_reserved_stack_access(false),
 930 #ifndef PRODUCT
 931       _igv_idx(0),
 932       _trace_opto_output(directive->TraceOptoOutputOption),
 933 #endif
 934       _clinit_barrier_on_entry(false),
 935       _has_clinit_barriers(false),
 936       _stress_seed(0),
 937       _comp_arena(mtCompiler, Arena::Tag::tag_comp),
 938       _barrier_set_state(BarrierSet::barrier_set()->barrier_set_c2()->create_barrier_state(comp_arena())),
 939       _env(ci_env),
 940       _directive(directive),
 941       _log(ci_env->log()),
 942       _first_failure_details(nullptr),
 943       _for_post_loop_igvn(comp_arena(), 8, 0, nullptr),
 944       _for_merge_stores_igvn(comp_arena(), 8, 0, nullptr),
 945       _congraph(nullptr),
 946       NOT_PRODUCT(_igv_printer(nullptr) COMMA)
 947           _unique(0),
 948       _dead_node_count(0),
 949       _dead_node_list(comp_arena()),
 950       _node_arena_one(mtCompiler, Arena::Tag::tag_node),
 951       _node_arena_two(mtCompiler, Arena::Tag::tag_node),
 952       _node_arena(&_node_arena_one),
 953       _mach_constant_base_node(nullptr),
 954       _Compile_types(mtCompiler, Arena::Tag::tag_type),
 955       _initial_gvn(nullptr),
 956       _igvn_worklist(nullptr),
 957       _types(nullptr),
 958       _node_hash(nullptr),
 959       _number_of_mh_late_inlines(0),
 960       _oom(false),
 961       _replay_inline_data(nullptr),
 962       _inline_printer(this),
 963       _java_calls(0),
 964       _inner_loops(0),
 965       _FIRST_STACK_mask(comp_arena()),
 966       _interpreter_frame_size(0),
 967       _regmask_arena(mtCompiler, Arena::Tag::tag_regmask),
 968       _output(nullptr),
 969 #ifndef PRODUCT
 970       _in_dump_cnt(0),
 971 #endif
 972       _allowed_reasons(0) {
 973   C = this;
 974 
 975   // try to reuse an existing stub
 976   {
 977     BlobId blob_id = StubInfo::blob(_stub_id);
 978     CodeBlob* blob = AOTCodeCache::load_code_blob(AOTCodeEntry::C2Blob, blob_id);
 979     if (blob != nullptr) {
 980       RuntimeStub* rs = blob->as_runtime_stub();
 981       _stub_entry_point = rs->entry_point();
 982       return;
 983     }
 984   }
 985 
 986   TraceTime t1(nullptr, &_t_totalCompilation, CITime, false);
 987   TraceTime t2(nullptr, &_t_stubCompilation, CITime, false);
 988 
 989 #ifndef PRODUCT
 990   set_print_assembly(PrintFrameConverterAssembly);
 991   set_parsed_irreducible_loop(false);
 992 #else
 993   set_print_assembly(false); // Must initialize.
 994 #endif
 995   set_has_irreducible_loop(false); // no loops
 996 
 997   CompileWrapper cw(this);
 998   Init(/*do_aliasing=*/ false);
 999   init_tf((*generator)());
1000 
1001   _igvn_worklist = new (comp_arena()) Unique_Node_List(comp_arena());
1002   _types = new (comp_arena()) Type_Array(comp_arena());
1003   _node_hash = new (comp_arena()) NodeHash(comp_arena(), 255);
1004 
1005   if (StressLCM || StressGCM || StressBailout) {
1006     initialize_stress_seed(directive);
1007   }
1008 
1009   {
1010     PhaseGVN gvn;
1011     set_initial_gvn(&gvn);    // not significant, but GraphKit guys use it pervasively
1012     gvn.transform(top());
1013 
1014     GraphKit kit;
1015     kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
1016   }
1017 
1018   NOT_PRODUCT( verify_graph_edges(); )
1019 
1020   Code_Gen();
1021 }
1022 
1023 Compile::~Compile() {
1024   delete _first_failure_details;
1025 };
1026 
1027 //------------------------------Init-------------------------------------------
1028 // Prepare for a single compilation
1029 void Compile::Init(bool aliasing) {
1030   _do_aliasing = aliasing;
1031   _unique  = 0;
1032   _regalloc = nullptr;
1033 
1034   _tf      = nullptr;  // filled in later
1035   _top     = nullptr;  // cached later
1036   _matcher = nullptr;  // filled in later
1037   _cfg     = nullptr;  // filled in later
1038 
1039   _node_note_array = nullptr;
1040   _default_node_notes = nullptr;
1041   DEBUG_ONLY( _modified_nodes = nullptr; ) // Used in Optimize()
1042 
1043   _immutable_memory = nullptr; // filled in at first inquiry
1044 
1045 #ifdef ASSERT
1046   _phase_optimize_finished = false;
1047   _phase_verify_ideal_loop = false;
1048   _exception_backedge = false;
1049   _type_verify = nullptr;
1050 #endif
1051 
1052   // Globally visible Nodes
1053   // First set TOP to null to give safe behavior during creation of RootNode
1054   set_cached_top_node(nullptr);
1055   set_root(new RootNode());
1056   // Now that you have a Root to point to, create the real TOP
1057   set_cached_top_node( new ConNode(Type::TOP) );
1058   set_recent_alloc(nullptr, nullptr);
1059 
1060   // Create Debug Information Recorder to record scopes, oopmaps, etc.
1061   env()->set_oop_recorder(new OopRecorder(env()->arena()));
1062   env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
1063   env()->set_dependencies(new Dependencies(env()));
1064 
1065   _fixed_slots = 0;
1066   set_has_split_ifs(false);
1067   set_has_loops(false); // first approximation
1068   set_has_stringbuilder(false);
1069   set_has_boxed_value(false);
1070   _trap_can_recompile = false;  // no traps emitted yet
1071   _major_progress = true; // start out assuming good things will happen
1072   set_has_unsafe_access(false);
1073   set_max_vector_size(0);
1074   set_clear_upper_avx(false);  //false as default for clear upper bits of ymm registers
1075   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
1076   set_decompile_count(0);
1077 
1078 #ifndef PRODUCT
1079   _phase_counter = 0;
1080   Copy::zero_to_bytes(_igv_phase_iter, sizeof(_igv_phase_iter));
1081 #endif
1082 
1083   set_do_freq_based_layout(_directive->BlockLayoutByFrequencyOption);
1084   _loop_opts_cnt = LoopOptsCount;
1085   set_do_inlining(Inline);
1086   set_max_inline_size(MaxInlineSize);
1087   set_freq_inline_size(FreqInlineSize);
1088   set_do_scheduling(OptoScheduling);
1089 
1090   set_do_vector_loop(false);
1091   set_has_monitors(false);
1092   set_has_scoped_access(false);
1093 
1094   if (AllowVectorizeOnDemand) {
1095     if (has_method() && _directive->VectorizeOption) {
1096       set_do_vector_loop(true);
1097       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());})
1098     } else if (has_method() && method()->name() != nullptr &&
1099                method()->intrinsic_id() == vmIntrinsics::_forEachRemaining) {
1100       set_do_vector_loop(true);
1101     }
1102   }
1103   set_use_cmove(UseCMoveUnconditionally /* || do_vector_loop()*/); //TODO: consider do_vector_loop() mandate use_cmove unconditionally
1104   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());})
1105 
1106   _max_node_limit = _directive->MaxNodeLimitOption;
1107 
1108   if (VM_Version::supports_fast_class_init_checks() && has_method() && !is_osr_compilation() &&
1109       (method()->needs_clinit_barrier() || (do_clinit_barriers() && method()->is_static()))) {
1110     set_clinit_barrier_on_entry(true);
1111     if (do_clinit_barriers()) {
1112       set_has_clinit_barriers(true); // Entry clinit barrier is in prolog code.
1113     }
1114   }
1115   if (debug_info()->recording_non_safepoints()) {
1116     set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
1117                         (comp_arena(), 8, 0, nullptr));
1118     set_default_node_notes(Node_Notes::make(this));
1119   }
1120 
1121   const int grow_ats = 16;
1122   _max_alias_types = grow_ats;
1123   _alias_types   = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
1124   AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType,  grow_ats);
1125   Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
1126   {
1127     for (int i = 0; i < grow_ats; i++)  _alias_types[i] = &ats[i];
1128   }
1129   // Initialize the first few types.
1130   _alias_types[AliasIdxTop]->Init(AliasIdxTop, nullptr);
1131   _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
1132   _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
1133   _num_alias_types = AliasIdxRaw+1;
1134   // Zero out the alias type cache.
1135   Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
1136   // A null adr_type hits in the cache right away.  Preload the right answer.
1137   probe_alias_cache(nullptr)->_index = AliasIdxTop;
1138 }
1139 
1140 #ifdef ASSERT
1141 // Verify that the current StartNode is valid.
1142 void Compile::verify_start(StartNode* s) const {
1143   assert(failing_internal() || s == start(), "should be StartNode");
1144 }
1145 #endif
1146 
1147 /**
1148  * Return the 'StartNode'. We must not have a pending failure, since the ideal graph
1149  * can be in an inconsistent state, i.e., we can get segmentation faults when traversing
1150  * the ideal graph.
1151  */
1152 StartNode* Compile::start() const {
1153   assert (!failing_internal() || C->failure_is_artificial(), "Must not have pending failure. Reason is: %s", failure_reason());
1154   for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
1155     Node* start = root()->fast_out(i);
1156     if (start->is_Start()) {
1157       return start->as_Start();
1158     }
1159   }
1160   fatal("Did not find Start node!");
1161   return nullptr;
1162 }
1163 
1164 //-------------------------------immutable_memory-------------------------------------
1165 // Access immutable memory
1166 Node* Compile::immutable_memory() {
1167   if (_immutable_memory != nullptr) {
1168     return _immutable_memory;
1169   }
1170   StartNode* s = start();
1171   for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
1172     Node *p = s->fast_out(i);
1173     if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
1174       _immutable_memory = p;
1175       return _immutable_memory;
1176     }
1177   }
1178   ShouldNotReachHere();
1179   return nullptr;
1180 }
1181 
1182 //----------------------set_cached_top_node------------------------------------
1183 // Install the cached top node, and make sure Node::is_top works correctly.
1184 void Compile::set_cached_top_node(Node* tn) {
1185   if (tn != nullptr)  verify_top(tn);
1186   Node* old_top = _top;
1187   _top = tn;
1188   // Calling Node::setup_is_top allows the nodes the chance to adjust
1189   // their _out arrays.
1190   if (_top != nullptr)     _top->setup_is_top();
1191   if (old_top != nullptr)  old_top->setup_is_top();
1192   assert(_top == nullptr || top()->is_top(), "");
1193 }
1194 
1195 #ifdef ASSERT
1196 uint Compile::count_live_nodes_by_graph_walk() {
1197   Unique_Node_List useful(comp_arena());
1198   // Get useful node list by walking the graph.
1199   identify_useful_nodes(useful);
1200   return useful.size();
1201 }
1202 
1203 void Compile::print_missing_nodes() {
1204 
1205   // Return if CompileLog is null and PrintIdealNodeCount is false.
1206   if ((_log == nullptr) && (! PrintIdealNodeCount)) {
1207     return;
1208   }
1209 
1210   // This is an expensive function. It is executed only when the user
1211   // specifies VerifyIdealNodeCount option or otherwise knows the
1212   // additional work that needs to be done to identify reachable nodes
1213   // by walking the flow graph and find the missing ones using
1214   // _dead_node_list.
1215 
1216   Unique_Node_List useful(comp_arena());
1217   // Get useful node list by walking the graph.
1218   identify_useful_nodes(useful);
1219 
1220   uint l_nodes = C->live_nodes();
1221   uint l_nodes_by_walk = useful.size();
1222 
1223   if (l_nodes != l_nodes_by_walk) {
1224     if (_log != nullptr) {
1225       _log->begin_head("mismatched_nodes count='%d'", abs((int) (l_nodes - l_nodes_by_walk)));
1226       _log->stamp();
1227       _log->end_head();
1228     }
1229     VectorSet& useful_member_set = useful.member_set();
1230     int last_idx = l_nodes_by_walk;
1231     for (int i = 0; i < last_idx; i++) {
1232       if (useful_member_set.test(i)) {
1233         if (_dead_node_list.test(i)) {
1234           if (_log != nullptr) {
1235             _log->elem("mismatched_node_info node_idx='%d' type='both live and dead'", i);
1236           }
1237           if (PrintIdealNodeCount) {
1238             // Print the log message to tty
1239               tty->print_cr("mismatched_node idx='%d' both live and dead'", i);
1240               useful.at(i)->dump();
1241           }
1242         }
1243       }
1244       else if (! _dead_node_list.test(i)) {
1245         if (_log != nullptr) {
1246           _log->elem("mismatched_node_info node_idx='%d' type='neither live nor dead'", i);
1247         }
1248         if (PrintIdealNodeCount) {
1249           // Print the log message to tty
1250           tty->print_cr("mismatched_node idx='%d' type='neither live nor dead'", i);
1251         }
1252       }
1253     }
1254     if (_log != nullptr) {
1255       _log->tail("mismatched_nodes");
1256     }
1257   }
1258 }
1259 void Compile::record_modified_node(Node* n) {
1260   if (_modified_nodes != nullptr && !_inlining_incrementally && !n->is_Con()) {
1261     _modified_nodes->push(n);
1262   }
1263 }
1264 
1265 void Compile::remove_modified_node(Node* n) {
1266   if (_modified_nodes != nullptr) {
1267     _modified_nodes->remove(n);
1268   }
1269 }
1270 #endif
1271 
1272 #ifndef PRODUCT
1273 void Compile::verify_top(Node* tn) const {
1274   if (tn != nullptr) {
1275     assert(tn->is_Con(), "top node must be a constant");
1276     assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
1277     assert(tn->in(0) != nullptr, "must have live top node");
1278   }
1279 }
1280 #endif
1281 
1282 
1283 ///-------------------Managing Per-Node Debug & Profile Info-------------------
1284 
1285 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
1286   guarantee(arr != nullptr, "");
1287   int num_blocks = arr->length();
1288   if (grow_by < num_blocks)  grow_by = num_blocks;
1289   int num_notes = grow_by * _node_notes_block_size;
1290   Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
1291   Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
1292   while (num_notes > 0) {
1293     arr->append(notes);
1294     notes     += _node_notes_block_size;
1295     num_notes -= _node_notes_block_size;
1296   }
1297   assert(num_notes == 0, "exact multiple, please");
1298 }
1299 
1300 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
1301   if (source == nullptr || dest == nullptr)  return false;
1302 
1303   if (dest->is_Con())
1304     return false;               // Do not push debug info onto constants.
1305 
1306 #ifdef ASSERT
1307   // Leave a bread crumb trail pointing to the original node:
1308   if (dest != nullptr && dest != source && dest->debug_orig() == nullptr) {
1309     dest->set_debug_orig(source);
1310   }
1311 #endif
1312 
1313   if (node_note_array() == nullptr)
1314     return false;               // Not collecting any notes now.
1315 
1316   // This is a copy onto a pre-existing node, which may already have notes.
1317   // If both nodes have notes, do not overwrite any pre-existing notes.
1318   Node_Notes* source_notes = node_notes_at(source->_idx);
1319   if (source_notes == nullptr || source_notes->is_clear())  return false;
1320   Node_Notes* dest_notes   = node_notes_at(dest->_idx);
1321   if (dest_notes == nullptr || dest_notes->is_clear()) {
1322     return set_node_notes_at(dest->_idx, source_notes);
1323   }
1324 
1325   Node_Notes merged_notes = (*source_notes);
1326   // The order of operations here ensures that dest notes will win...
1327   merged_notes.update_from(dest_notes);
1328   return set_node_notes_at(dest->_idx, &merged_notes);
1329 }
1330 
1331 
1332 //--------------------------allow_range_check_smearing-------------------------
1333 // Gating condition for coalescing similar range checks.
1334 // Sometimes we try 'speculatively' replacing a series of a range checks by a
1335 // single covering check that is at least as strong as any of them.
1336 // If the optimization succeeds, the simplified (strengthened) range check
1337 // will always succeed.  If it fails, we will deopt, and then give up
1338 // on the optimization.
1339 bool Compile::allow_range_check_smearing() const {
1340   // If this method has already thrown a range-check,
1341   // assume it was because we already tried range smearing
1342   // and it failed.
1343   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
1344   return !already_trapped;
1345 }
1346 
1347 
1348 //------------------------------flatten_alias_type-----------------------------
1349 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
1350   assert(do_aliasing(), "Aliasing should be enabled");
1351   int offset = tj->offset();
1352   TypePtr::PTR ptr = tj->ptr();
1353 
1354   // Known instance (scalarizable allocation) alias only with itself.
1355   bool is_known_inst = tj->isa_oopptr() != nullptr &&
1356                        tj->is_oopptr()->is_known_instance();
1357 
1358   // Process weird unsafe references.
1359   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
1360     assert(InlineUnsafeOps || StressReflectiveCode, "indeterminate pointers come only from unsafe ops");
1361     assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
1362     tj = TypeOopPtr::BOTTOM;
1363     ptr = tj->ptr();
1364     offset = tj->offset();
1365   }
1366 
1367   // Array pointers need some flattening
1368   const TypeAryPtr* ta = tj->isa_aryptr();
1369   if (ta && ta->is_stable()) {
1370     // Erase stability property for alias analysis.
1371     tj = ta = ta->cast_to_stable(false);
1372   }
1373   if( ta && is_known_inst ) {
1374     if ( offset != Type::OffsetBot &&
1375          offset > arrayOopDesc::length_offset_in_bytes() ) {
1376       offset = Type::OffsetBot; // Flatten constant access into array body only
1377       tj = ta = ta->
1378               remove_speculative()->
1379               cast_to_ptr_type(ptr)->
1380               with_offset(offset);
1381     }
1382   } else if (ta) {
1383     // For arrays indexed by constant indices, we flatten the alias
1384     // space to include all of the array body.  Only the header, klass
1385     // and array length can be accessed un-aliased.
1386     if( offset != Type::OffsetBot ) {
1387       if( ta->const_oop() ) { // MethodData* or Method*
1388         offset = Type::OffsetBot;   // Flatten constant access into array body
1389         tj = ta = ta->
1390                 remove_speculative()->
1391                 cast_to_ptr_type(ptr)->
1392                 cast_to_exactness(false)->
1393                 with_offset(offset);
1394       } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
1395         // range is OK as-is.
1396         tj = ta = TypeAryPtr::RANGE;
1397       } else if( offset == oopDesc::klass_offset_in_bytes() ) {
1398         tj = TypeInstPtr::KLASS; // all klass loads look alike
1399         ta = TypeAryPtr::RANGE; // generic ignored junk
1400         ptr = TypePtr::BotPTR;
1401       } else if( offset == oopDesc::mark_offset_in_bytes() ) {
1402         tj = TypeInstPtr::MARK;
1403         ta = TypeAryPtr::RANGE; // generic ignored junk
1404         ptr = TypePtr::BotPTR;
1405       } else {                  // Random constant offset into array body
1406         offset = Type::OffsetBot;   // Flatten constant access into array body
1407         tj = ta = ta->
1408                 remove_speculative()->
1409                 cast_to_ptr_type(ptr)->
1410                 cast_to_exactness(false)->
1411                 with_offset(offset);
1412       }
1413     }
1414     // Arrays of fixed size alias with arrays of unknown size.
1415     if (ta->size() != TypeInt::POS) {
1416       const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
1417       tj = ta = ta->
1418               remove_speculative()->
1419               cast_to_ptr_type(ptr)->
1420               with_ary(tary)->
1421               cast_to_exactness(false);
1422     }
1423     // Arrays of known objects become arrays of unknown objects.
1424     if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
1425       const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
1426       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,nullptr,false,offset);
1427     }
1428     if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
1429       const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
1430       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,nullptr,false,offset);
1431     }
1432     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
1433     // cannot be distinguished by bytecode alone.
1434     if (ta->elem() == TypeInt::BOOL) {
1435       const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
1436       ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
1437       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,offset);
1438     }
1439     // During the 2nd round of IterGVN, NotNull castings are removed.
1440     // Make sure the Bottom and NotNull variants alias the same.
1441     // Also, make sure exact and non-exact variants alias the same.
1442     if (ptr == TypePtr::NotNull || ta->klass_is_exact() || ta->speculative() != nullptr) {
1443       tj = ta = ta->
1444               remove_speculative()->
1445               cast_to_ptr_type(TypePtr::BotPTR)->
1446               cast_to_exactness(false)->
1447               with_offset(offset);
1448     }
1449   }
1450 
1451   // Oop pointers need some flattening
1452   const TypeInstPtr *to = tj->isa_instptr();
1453   if (to && to != TypeOopPtr::BOTTOM) {
1454     ciInstanceKlass* ik = to->instance_klass();
1455     if( ptr == TypePtr::Constant ) {
1456       if (ik != ciEnv::current()->Class_klass() ||
1457           offset < ik->layout_helper_size_in_bytes()) {
1458         // No constant oop pointers (such as Strings); they alias with
1459         // unknown strings.
1460         assert(!is_known_inst, "not scalarizable allocation");
1461         tj = to = to->
1462                 cast_to_instance_id(TypeOopPtr::InstanceBot)->
1463                 remove_speculative()->
1464                 cast_to_ptr_type(TypePtr::BotPTR)->
1465                 cast_to_exactness(false);
1466       }
1467     } else if( is_known_inst ) {
1468       tj = to; // Keep NotNull and klass_is_exact for instance type
1469     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
1470       // During the 2nd round of IterGVN, NotNull castings are removed.
1471       // Make sure the Bottom and NotNull variants alias the same.
1472       // Also, make sure exact and non-exact variants alias the same.
1473       tj = to = to->
1474               remove_speculative()->
1475               cast_to_instance_id(TypeOopPtr::InstanceBot)->
1476               cast_to_ptr_type(TypePtr::BotPTR)->
1477               cast_to_exactness(false);
1478     }
1479     if (to->speculative() != nullptr) {
1480       tj = to = to->remove_speculative();
1481     }
1482     // Canonicalize the holder of this field
1483     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
1484       // First handle header references such as a LoadKlassNode, even if the
1485       // object's klass is unloaded at compile time (4965979).
1486       if (!is_known_inst) { // Do it only for non-instance types
1487         tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, nullptr, offset);
1488       }
1489     } else if (offset < 0 || offset >= ik->layout_helper_size_in_bytes()) {
1490       // Static fields are in the space above the normal instance
1491       // fields in the java.lang.Class instance.
1492       if (ik != ciEnv::current()->Class_klass()) {
1493         to = nullptr;
1494         tj = TypeOopPtr::BOTTOM;
1495         offset = tj->offset();
1496       }
1497     } else {
1498       ciInstanceKlass *canonical_holder = ik->get_canonical_holder(offset);
1499       assert(offset < canonical_holder->layout_helper_size_in_bytes(), "");
1500       assert(tj->offset() == offset, "no change to offset expected");
1501       bool xk = to->klass_is_exact();
1502       int instance_id = to->instance_id();
1503 
1504       // If the input type's class is the holder: if exact, the type only includes interfaces implemented by the holder
1505       // but if not exact, it may include extra interfaces: build new type from the holder class to make sure only
1506       // its interfaces are included.
1507       if (xk && ik->equals(canonical_holder)) {
1508         assert(tj == TypeInstPtr::make(to->ptr(), canonical_holder, is_known_inst, nullptr, offset, instance_id), "exact type should be canonical type");
1509       } else {
1510         assert(xk || !is_known_inst, "Known instance should be exact type");
1511         tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, is_known_inst, nullptr, offset, instance_id);
1512       }
1513     }
1514   }
1515 
1516   // Klass pointers to object array klasses need some flattening
1517   const TypeKlassPtr *tk = tj->isa_klassptr();
1518   if( tk ) {
1519     // If we are referencing a field within a Klass, we need
1520     // to assume the worst case of an Object.  Both exact and
1521     // inexact types must flatten to the same alias class so
1522     // use NotNull as the PTR.
1523     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
1524       tj = tk = TypeInstKlassPtr::make(TypePtr::NotNull,
1525                                        env()->Object_klass(),
1526                                        offset);
1527     }
1528 
1529     if (tk->isa_aryklassptr() && tk->is_aryklassptr()->elem()->isa_klassptr()) {
1530       ciKlass* k = ciObjArrayKlass::make(env()->Object_klass());
1531       if (!k || !k->is_loaded()) {                  // Only fails for some -Xcomp runs
1532         tj = tk = TypeInstKlassPtr::make(TypePtr::NotNull, env()->Object_klass(), offset);
1533       } else {
1534         tj = tk = TypeAryKlassPtr::make(TypePtr::NotNull, tk->is_aryklassptr()->elem(), k, offset);
1535       }
1536     }
1537 
1538     // Check for precise loads from the primary supertype array and force them
1539     // to the supertype cache alias index.  Check for generic array loads from
1540     // the primary supertype array and also force them to the supertype cache
1541     // alias index.  Since the same load can reach both, we need to merge
1542     // these 2 disparate memories into the same alias class.  Since the
1543     // primary supertype array is read-only, there's no chance of confusion
1544     // where we bypass an array load and an array store.
1545     int primary_supers_offset = in_bytes(Klass::primary_supers_offset());
1546     if (offset == Type::OffsetBot ||
1547         (offset >= primary_supers_offset &&
1548          offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
1549         offset == (int)in_bytes(Klass::secondary_super_cache_offset())) {
1550       offset = in_bytes(Klass::secondary_super_cache_offset());
1551       tj = tk = tk->with_offset(offset);
1552     }
1553   }
1554 
1555   // Flatten all Raw pointers together.
1556   if (tj->base() == Type::RawPtr)
1557     tj = TypeRawPtr::BOTTOM;
1558 
1559   if (tj->base() == Type::AnyPtr)
1560     tj = TypePtr::BOTTOM;      // An error, which the caller must check for.
1561 
1562   offset = tj->offset();
1563   assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
1564 
1565   assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
1566           (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
1567           (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
1568           (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
1569           (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1570           (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1571           (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr),
1572           "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
1573   assert( tj->ptr() != TypePtr::TopPTR &&
1574           tj->ptr() != TypePtr::AnyNull &&
1575           tj->ptr() != TypePtr::Null, "No imprecise addresses" );
1576 //    assert( tj->ptr() != TypePtr::Constant ||
1577 //            tj->base() == Type::RawPtr ||
1578 //            tj->base() == Type::KlassPtr, "No constant oop addresses" );
1579 
1580   return tj;
1581 }
1582 
1583 void Compile::AliasType::Init(int i, const TypePtr* at) {
1584   assert(AliasIdxTop <= i && i < Compile::current()->_max_alias_types, "Invalid alias index");
1585   _index = i;
1586   _adr_type = at;
1587   _field = nullptr;
1588   _element = nullptr;
1589   _is_rewritable = true; // default
1590   const TypeOopPtr *atoop = (at != nullptr) ? at->isa_oopptr() : nullptr;
1591   if (atoop != nullptr && atoop->is_known_instance()) {
1592     const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
1593     _general_index = Compile::current()->get_alias_index(gt);
1594   } else {
1595     _general_index = 0;
1596   }
1597 }
1598 
1599 BasicType Compile::AliasType::basic_type() const {
1600   if (element() != nullptr) {
1601     const Type* element = adr_type()->is_aryptr()->elem();
1602     return element->isa_narrowoop() ? T_OBJECT : element->array_element_basic_type();
1603   } if (field() != nullptr) {
1604     return field()->layout_type();
1605   } else {
1606     return T_ILLEGAL; // unknown
1607   }
1608 }
1609 
1610 //---------------------------------print_on------------------------------------
1611 #ifndef PRODUCT
1612 void Compile::AliasType::print_on(outputStream* st) {
1613   if (index() < 10)
1614         st->print("@ <%d> ", index());
1615   else  st->print("@ <%d>",  index());
1616   st->print(is_rewritable() ? "   " : " RO");
1617   int offset = adr_type()->offset();
1618   if (offset == Type::OffsetBot)
1619         st->print(" +any");
1620   else  st->print(" +%-3d", offset);
1621   st->print(" in ");
1622   adr_type()->dump_on(st);
1623   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
1624   if (field() != nullptr && tjp) {
1625     if (tjp->is_instptr()->instance_klass()  != field()->holder() ||
1626         tjp->offset() != field()->offset_in_bytes()) {
1627       st->print(" != ");
1628       field()->print();
1629       st->print(" ***");
1630     }
1631   }
1632 }
1633 
1634 void print_alias_types() {
1635   Compile* C = Compile::current();
1636   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
1637   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
1638     C->alias_type(idx)->print_on(tty);
1639     tty->cr();
1640   }
1641 }
1642 #endif
1643 
1644 
1645 //----------------------------probe_alias_cache--------------------------------
1646 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
1647   intptr_t key = (intptr_t) adr_type;
1648   key ^= key >> logAliasCacheSize;
1649   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
1650 }
1651 
1652 
1653 //-----------------------------grow_alias_types--------------------------------
1654 void Compile::grow_alias_types() {
1655   const int old_ats  = _max_alias_types; // how many before?
1656   const int new_ats  = old_ats;          // how many more?
1657   const int grow_ats = old_ats+new_ats;  // how many now?
1658   _max_alias_types = grow_ats;
1659   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
1660   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
1661   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
1662   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
1663 }
1664 
1665 
1666 //--------------------------------find_alias_type------------------------------
1667 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field) {
1668   if (!do_aliasing()) {
1669     return alias_type(AliasIdxBot);
1670   }
1671 
1672   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1673   if (ace->_adr_type == adr_type) {
1674     return alias_type(ace->_index);
1675   }
1676 
1677   // Handle special cases.
1678   if (adr_type == nullptr)          return alias_type(AliasIdxTop);
1679   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
1680 
1681   // Do it the slow way.
1682   const TypePtr* flat = flatten_alias_type(adr_type);
1683 
1684 #ifdef ASSERT
1685   {
1686     ResourceMark rm;
1687     assert(flat == flatten_alias_type(flat), "not idempotent: adr_type = %s; flat = %s => %s",
1688            Type::str(adr_type), Type::str(flat), Type::str(flatten_alias_type(flat)));
1689     assert(flat != TypePtr::BOTTOM, "cannot alias-analyze an untyped ptr: adr_type = %s",
1690            Type::str(adr_type));
1691     if (flat->isa_oopptr() && !flat->isa_klassptr()) {
1692       const TypeOopPtr* foop = flat->is_oopptr();
1693       // Scalarizable allocations have exact klass always.
1694       bool exact = !foop->klass_is_exact() || foop->is_known_instance();
1695       const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
1696       assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type: foop = %s; xoop = %s",
1697              Type::str(foop), Type::str(xoop));
1698     }
1699   }
1700 #endif
1701 
1702   int idx = AliasIdxTop;
1703   for (int i = 0; i < num_alias_types(); i++) {
1704     if (alias_type(i)->adr_type() == flat) {
1705       idx = i;
1706       break;
1707     }
1708   }
1709 
1710   if (idx == AliasIdxTop) {
1711     if (no_create)  return nullptr;
1712     // Grow the array if necessary.
1713     if (_num_alias_types == _max_alias_types)  grow_alias_types();
1714     // Add a new alias type.
1715     idx = _num_alias_types++;
1716     _alias_types[idx]->Init(idx, flat);
1717     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
1718     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
1719     if (flat->isa_instptr()) {
1720       if (flat->offset() == java_lang_Class::klass_offset()
1721           && flat->is_instptr()->instance_klass() == env()->Class_klass())
1722         alias_type(idx)->set_rewritable(false);
1723     }
1724     if (flat->isa_aryptr()) {
1725 #ifdef ASSERT
1726       const int header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1727       // (T_BYTE has the weakest alignment and size restrictions...)
1728       assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
1729 #endif
1730       if (flat->offset() == TypePtr::OffsetBot) {
1731         alias_type(idx)->set_element(flat->is_aryptr()->elem());
1732       }
1733     }
1734     if (flat->isa_klassptr()) {
1735       if (UseCompactObjectHeaders) {
1736         if (flat->offset() == in_bytes(Klass::prototype_header_offset()))
1737           alias_type(idx)->set_rewritable(false);
1738       }
1739       if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
1740         alias_type(idx)->set_rewritable(false);
1741       if (flat->offset() == in_bytes(Klass::access_flags_offset()))
1742         alias_type(idx)->set_rewritable(false);
1743       if (flat->offset() == in_bytes(Klass::misc_flags_offset()))
1744         alias_type(idx)->set_rewritable(false);
1745       if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
1746         alias_type(idx)->set_rewritable(false);
1747       if (flat->offset() == in_bytes(Klass::secondary_super_cache_offset()))
1748         alias_type(idx)->set_rewritable(false);
1749     }
1750     // %%% (We would like to finalize JavaThread::threadObj_offset(),
1751     // but the base pointer type is not distinctive enough to identify
1752     // references into JavaThread.)
1753 
1754     // Check for final fields.
1755     const TypeInstPtr* tinst = flat->isa_instptr();
1756     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
1757       ciField* field;
1758       if (tinst->const_oop() != nullptr &&
1759           tinst->instance_klass() == ciEnv::current()->Class_klass() &&
1760           tinst->offset() >= (tinst->instance_klass()->layout_helper_size_in_bytes())) {
1761         // static field
1762         ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
1763         field = k->get_field_by_offset(tinst->offset(), true);
1764       } else {
1765         ciInstanceKlass *k = tinst->instance_klass();
1766         field = k->get_field_by_offset(tinst->offset(), false);
1767       }
1768       assert(field == nullptr ||
1769              original_field == nullptr ||
1770              (field->holder() == original_field->holder() &&
1771               field->offset_in_bytes() == original_field->offset_in_bytes() &&
1772               field->is_static() == original_field->is_static()), "wrong field?");
1773       // Set field() and is_rewritable() attributes.
1774       if (field != nullptr)  alias_type(idx)->set_field(field);
1775     }
1776   }
1777 
1778   // Fill the cache for next time.
1779   ace->_adr_type = adr_type;
1780   ace->_index    = idx;
1781   assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
1782 
1783   // Might as well try to fill the cache for the flattened version, too.
1784   AliasCacheEntry* face = probe_alias_cache(flat);
1785   if (face->_adr_type == nullptr) {
1786     face->_adr_type = flat;
1787     face->_index    = idx;
1788     assert(alias_type(flat) == alias_type(idx), "flat type must work too");
1789   }
1790 
1791   return alias_type(idx);
1792 }
1793 
1794 
1795 Compile::AliasType* Compile::alias_type(ciField* field) {
1796   const TypeOopPtr* t;
1797   if (field->is_static())
1798     t = TypeInstPtr::make(field->holder()->java_mirror());
1799   else
1800     t = TypeOopPtr::make_from_klass_raw(field->holder());
1801   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);
1802   assert((field->is_final() || field->is_stable()) == !atp->is_rewritable(), "must get the rewritable bits correct");
1803   return atp;
1804 }
1805 
1806 
1807 //------------------------------have_alias_type--------------------------------
1808 bool Compile::have_alias_type(const TypePtr* adr_type) {
1809   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1810   if (ace->_adr_type == adr_type) {
1811     return true;
1812   }
1813 
1814   // Handle special cases.
1815   if (adr_type == nullptr)             return true;
1816   if (adr_type == TypePtr::BOTTOM)  return true;
1817 
1818   return find_alias_type(adr_type, true, nullptr) != nullptr;
1819 }
1820 
1821 //-----------------------------must_alias--------------------------------------
1822 // True if all values of the given address type are in the given alias category.
1823 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
1824   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1825   if (adr_type == nullptr)              return true;  // null serves as TypePtr::TOP
1826   if (alias_idx == AliasIdxTop)         return false; // the empty category
1827   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
1828 
1829   // the only remaining possible overlap is identity
1830   int adr_idx = get_alias_index(adr_type);
1831   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1832   assert(adr_idx == alias_idx ||
1833          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
1834           && adr_type                       != TypeOopPtr::BOTTOM),
1835          "should not be testing for overlap with an unsafe pointer");
1836   return adr_idx == alias_idx;
1837 }
1838 
1839 //------------------------------can_alias--------------------------------------
1840 // True if any values of the given address type are in the given alias category.
1841 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
1842   if (alias_idx == AliasIdxTop)         return false; // the empty category
1843   if (adr_type == nullptr)              return false; // null serves as TypePtr::TOP
1844   // Known instance doesn't alias with bottom memory
1845   if (alias_idx == AliasIdxBot)         return !adr_type->is_known_instance();                   // the universal category
1846   if (adr_type->base() == Type::AnyPtr) return !C->get_adr_type(alias_idx)->is_known_instance(); // TypePtr::BOTTOM or its twins
1847 
1848   // the only remaining possible overlap is identity
1849   int adr_idx = get_alias_index(adr_type);
1850   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1851   return adr_idx == alias_idx;
1852 }
1853 
1854 // Mark all ParsePredicateNodes as useless. They will later be removed from the graph in IGVN together with their
1855 // uncommon traps if no Runtime Predicates were created from the Parse Predicates.
1856 void Compile::mark_parse_predicate_nodes_useless(PhaseIterGVN& igvn) {
1857   if (parse_predicate_count() == 0) {
1858     return;
1859   }
1860   for (int i = 0; i < parse_predicate_count(); i++) {
1861     ParsePredicateNode* parse_predicate = _parse_predicates.at(i);
1862     parse_predicate->mark_useless(igvn);
1863   }
1864   _parse_predicates.clear();
1865 }
1866 
1867 void Compile::record_for_post_loop_opts_igvn(Node* n) {
1868   if (!n->for_post_loop_opts_igvn()) {
1869     assert(!_for_post_loop_igvn.contains(n), "duplicate");
1870     n->add_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
1871     _for_post_loop_igvn.append(n);
1872   }
1873 }
1874 
1875 void Compile::remove_from_post_loop_opts_igvn(Node* n) {
1876   n->remove_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
1877   _for_post_loop_igvn.remove(n);
1878 }
1879 
1880 void Compile::process_for_post_loop_opts_igvn(PhaseIterGVN& igvn) {
1881   // Verify that all previous optimizations produced a valid graph
1882   // at least to this point, even if no loop optimizations were done.
1883   PhaseIdealLoop::verify(igvn);
1884 
1885   if (has_loops() || _loop_opts_cnt > 0) {
1886     print_method(PHASE_AFTER_LOOP_OPTS, 2);
1887   }
1888   C->set_post_loop_opts_phase(); // no more loop opts allowed
1889 
1890   assert(!C->major_progress(), "not cleared");
1891 
1892   if (_for_post_loop_igvn.length() > 0) {
1893     while (_for_post_loop_igvn.length() > 0) {
1894       Node* n = _for_post_loop_igvn.pop();
1895       n->remove_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
1896       igvn._worklist.push(n);
1897     }
1898     igvn.optimize();
1899     if (failing()) return;
1900     assert(_for_post_loop_igvn.length() == 0, "no more delayed nodes allowed");
1901     assert(C->parse_predicate_count() == 0, "all parse predicates should have been removed now");
1902 
1903     // Sometimes IGVN sets major progress (e.g., when processing loop nodes).
1904     if (C->major_progress()) {
1905       C->clear_major_progress(); // ensure that major progress is now clear
1906     }
1907   }
1908 }
1909 
1910 void Compile::record_for_merge_stores_igvn(Node* n) {
1911   if (!n->for_merge_stores_igvn()) {
1912     assert(!_for_merge_stores_igvn.contains(n), "duplicate");
1913     n->add_flag(Node::NodeFlags::Flag_for_merge_stores_igvn);
1914     _for_merge_stores_igvn.append(n);
1915   }
1916 }
1917 
1918 void Compile::remove_from_merge_stores_igvn(Node* n) {
1919   n->remove_flag(Node::NodeFlags::Flag_for_merge_stores_igvn);
1920   _for_merge_stores_igvn.remove(n);
1921 }
1922 
1923 // We need to wait with merging stores until RangeCheck smearing has removed the RangeChecks during
1924 // the post loops IGVN phase. If we do it earlier, then there may still be some RangeChecks between
1925 // the stores, and we merge the wrong sequence of stores.
1926 // Example:
1927 //   StoreI RangeCheck StoreI StoreI RangeCheck StoreI
1928 // Apply MergeStores:
1929 //   StoreI RangeCheck [   StoreL  ] RangeCheck StoreI
1930 // Remove more RangeChecks:
1931 //   StoreI            [   StoreL  ]            StoreI
1932 // But now it would have been better to do this instead:
1933 //   [         StoreL       ] [       StoreL         ]
1934 //
1935 // Note: we allow stores to merge in this dedicated IGVN round, and any later IGVN round,
1936 //       since we never unset _merge_stores_phase.
1937 void Compile::process_for_merge_stores_igvn(PhaseIterGVN& igvn) {
1938   C->set_merge_stores_phase();
1939 
1940   if (_for_merge_stores_igvn.length() > 0) {
1941     while (_for_merge_stores_igvn.length() > 0) {
1942       Node* n = _for_merge_stores_igvn.pop();
1943       n->remove_flag(Node::NodeFlags::Flag_for_merge_stores_igvn);
1944       igvn._worklist.push(n);
1945     }
1946     igvn.optimize();
1947     if (failing()) return;
1948     assert(_for_merge_stores_igvn.length() == 0, "no more delayed nodes allowed");
1949     print_method(PHASE_AFTER_MERGE_STORES, 3);
1950   }
1951 }
1952 
1953 void Compile::record_unstable_if_trap(UnstableIfTrap* trap) {
1954   if (OptimizeUnstableIf) {
1955     _unstable_if_traps.append(trap);
1956   }
1957 }
1958 
1959 void Compile::remove_useless_unstable_if_traps(Unique_Node_List& useful) {
1960   for (int i = _unstable_if_traps.length() - 1; i >= 0; i--) {
1961     UnstableIfTrap* trap = _unstable_if_traps.at(i);
1962     Node* n = trap->uncommon_trap();
1963     if (!useful.member(n)) {
1964       _unstable_if_traps.delete_at(i); // replaces i-th with last element which is known to be useful (already processed)
1965     }
1966   }
1967 }
1968 
1969 // Remove the unstable if trap associated with 'unc' from candidates. It is either dead
1970 // or fold-compares case. Return true if succeed or not found.
1971 //
1972 // In rare cases, the found trap has been processed. It is too late to delete it. Return
1973 // false and ask fold-compares to yield.
1974 //
1975 // 'fold-compares' may use the uncommon_trap of the dominating IfNode to cover the fused
1976 // IfNode. This breaks the unstable_if trap invariant: control takes the unstable path
1977 // when deoptimization does happen.
1978 bool Compile::remove_unstable_if_trap(CallStaticJavaNode* unc, bool yield) {
1979   for (int i = 0; i < _unstable_if_traps.length(); ++i) {
1980     UnstableIfTrap* trap = _unstable_if_traps.at(i);
1981     if (trap->uncommon_trap() == unc) {
1982       if (yield && trap->modified()) {
1983         return false;
1984       }
1985       _unstable_if_traps.delete_at(i);
1986       break;
1987     }
1988   }
1989   return true;
1990 }
1991 
1992 // Re-calculate unstable_if traps with the liveness of next_bci, which points to the unlikely path.
1993 // It needs to be done after igvn because fold-compares may fuse uncommon_traps and before renumbering.
1994 void Compile::process_for_unstable_if_traps(PhaseIterGVN& igvn) {
1995   for (int i = _unstable_if_traps.length() - 1; i >= 0; --i) {
1996     UnstableIfTrap* trap = _unstable_if_traps.at(i);
1997     CallStaticJavaNode* unc = trap->uncommon_trap();
1998     int next_bci = trap->next_bci();
1999     bool modified = trap->modified();
2000 
2001     if (next_bci != -1 && !modified) {
2002       assert(!_dead_node_list.test(unc->_idx), "changing a dead node!");
2003       JVMState* jvms = unc->jvms();
2004       ciMethod* method = jvms->method();
2005       ciBytecodeStream iter(method);
2006 
2007       iter.force_bci(jvms->bci());
2008       assert(next_bci == iter.next_bci() || next_bci == iter.get_dest(), "wrong next_bci at unstable_if");
2009       Bytecodes::Code c = iter.cur_bc();
2010       Node* lhs = nullptr;
2011       Node* rhs = nullptr;
2012       if (c == Bytecodes::_if_acmpeq || c == Bytecodes::_if_acmpne) {
2013         lhs = unc->peek_operand(0);
2014         rhs = unc->peek_operand(1);
2015       } else if (c == Bytecodes::_ifnull || c == Bytecodes::_ifnonnull) {
2016         lhs = unc->peek_operand(0);
2017       }
2018 
2019       ResourceMark rm;
2020       const MethodLivenessResult& live_locals = method->liveness_at_bci(next_bci);
2021       assert(live_locals.is_valid(), "broken liveness info");
2022       int len = (int)live_locals.size();
2023 
2024       for (int i = 0; i < len; i++) {
2025         Node* local = unc->local(jvms, i);
2026         // kill local using the liveness of next_bci.
2027         // give up when the local looks like an operand to secure reexecution.
2028         if (!live_locals.at(i) && !local->is_top() && local != lhs && local!= rhs) {
2029           uint idx = jvms->locoff() + i;
2030 #ifdef ASSERT
2031           if (PrintOpto && Verbose) {
2032             tty->print("[unstable_if] kill local#%d: ", idx);
2033             local->dump();
2034             tty->cr();
2035           }
2036 #endif
2037           igvn.replace_input_of(unc, idx, top());
2038           modified = true;
2039         }
2040       }
2041     }
2042 
2043     // keep the mondified trap for late query
2044     if (modified) {
2045       trap->set_modified();
2046     } else {
2047       _unstable_if_traps.delete_at(i);
2048     }
2049   }
2050   igvn.optimize();
2051 }
2052 
2053 // StringOpts and late inlining of string methods
2054 void Compile::inline_string_calls(bool parse_time) {
2055   {
2056     // remove useless nodes to make the usage analysis simpler
2057     ResourceMark rm;
2058     PhaseRemoveUseless pru(initial_gvn(), *igvn_worklist());
2059   }
2060 
2061   {
2062     ResourceMark rm;
2063     print_method(PHASE_BEFORE_STRINGOPTS, 3);
2064     PhaseStringOpts pso(initial_gvn());
2065     print_method(PHASE_AFTER_STRINGOPTS, 3);
2066   }
2067 
2068   // now inline anything that we skipped the first time around
2069   if (!parse_time) {
2070     _late_inlines_pos = _late_inlines.length();
2071   }
2072 
2073   while (_string_late_inlines.length() > 0) {
2074     CallGenerator* cg = _string_late_inlines.pop();
2075     cg->do_late_inline();
2076     if (failing())  return;
2077   }
2078   _string_late_inlines.trunc_to(0);
2079 }
2080 
2081 // Late inlining of boxing methods
2082 void Compile::inline_boxing_calls(PhaseIterGVN& igvn) {
2083   if (_boxing_late_inlines.length() > 0) {
2084     assert(has_boxed_value(), "inconsistent");
2085 
2086     set_inlining_incrementally(true);
2087 
2088     igvn_worklist()->ensure_empty(); // should be done with igvn
2089 
2090     _late_inlines_pos = _late_inlines.length();
2091 
2092     while (_boxing_late_inlines.length() > 0) {
2093       CallGenerator* cg = _boxing_late_inlines.pop();
2094       cg->do_late_inline();
2095       if (failing())  return;
2096     }
2097     _boxing_late_inlines.trunc_to(0);
2098 
2099     inline_incrementally_cleanup(igvn);
2100 
2101     set_inlining_incrementally(false);
2102   }
2103 }
2104 
2105 bool Compile::inline_incrementally_one() {
2106   assert(IncrementalInline, "incremental inlining should be on");
2107 
2108   TracePhase tp(_t_incrInline_inline);
2109 
2110   set_inlining_progress(false);
2111   set_do_cleanup(false);
2112 
2113   for (int i = 0; i < _late_inlines.length(); i++) {
2114     _late_inlines_pos = i+1;
2115     CallGenerator* cg = _late_inlines.at(i);
2116     bool is_scheduled_for_igvn_before = C->igvn_worklist()->member(cg->call_node());
2117     bool does_dispatch = cg->is_virtual_late_inline() || cg->is_mh_late_inline();
2118     if (inlining_incrementally() || does_dispatch) { // a call can be either inlined or strength-reduced to a direct call
2119       if (should_stress_inlining()) {
2120         // randomly add repeated inline attempt if stress-inlining
2121         cg->call_node()->set_generator(cg);
2122         C->igvn_worklist()->push(cg->call_node());
2123         continue;
2124       }
2125       cg->do_late_inline();
2126       assert(_late_inlines.at(i) == cg, "no insertions before current position allowed");
2127       if (failing()) {
2128         return false;
2129       } else if (inlining_progress()) {
2130         _late_inlines_pos = i+1; // restore the position in case new elements were inserted
2131         print_method(PHASE_INCREMENTAL_INLINE_STEP, 3, cg->call_node());
2132         break; // process one call site at a time
2133       } else {
2134         bool is_scheduled_for_igvn_after = C->igvn_worklist()->member(cg->call_node());
2135         if (!is_scheduled_for_igvn_before && is_scheduled_for_igvn_after) {
2136           // Avoid potential infinite loop if node already in the IGVN list
2137           assert(false, "scheduled for IGVN during inlining attempt");
2138         } else {
2139           // Ensure call node has not disappeared from IGVN worklist during a failed inlining attempt
2140           assert(!is_scheduled_for_igvn_before || is_scheduled_for_igvn_after, "call node removed from IGVN list during inlining pass");
2141           cg->call_node()->set_generator(cg);
2142         }
2143       }
2144     } else {
2145       // Ignore late inline direct calls when inlining is not allowed.
2146       // They are left in the late inline list when node budget is exhausted until the list is fully drained.
2147     }
2148   }
2149   // Remove processed elements.
2150   _late_inlines.remove_till(_late_inlines_pos);
2151   _late_inlines_pos = 0;
2152 
2153   assert(inlining_progress() || _late_inlines.length() == 0, "no progress");
2154 
2155   bool needs_cleanup = do_cleanup() || over_inlining_cutoff();
2156 
2157   set_inlining_progress(false);
2158   set_do_cleanup(false);
2159 
2160   bool force_cleanup = directive()->IncrementalInlineForceCleanupOption;
2161   return (_late_inlines.length() > 0) && !needs_cleanup && !force_cleanup;
2162 }
2163 
2164 void Compile::inline_incrementally_cleanup(PhaseIterGVN& igvn) {
2165   {
2166     TracePhase tp(_t_incrInline_pru);
2167     ResourceMark rm;
2168     PhaseRemoveUseless pru(initial_gvn(), *igvn_worklist());
2169   }
2170   {
2171     TracePhase tp(_t_incrInline_igvn);
2172     igvn.reset();
2173     igvn.optimize();
2174     if (failing()) return;
2175   }
2176   print_method(PHASE_INCREMENTAL_INLINE_CLEANUP, 3);
2177 }
2178 
2179 // Perform incremental inlining until bound on number of live nodes is reached
2180 void Compile::inline_incrementally(PhaseIterGVN& igvn) {
2181   TracePhase tp(_t_incrInline);
2182 
2183   set_inlining_incrementally(true);
2184   uint low_live_nodes = 0;
2185 
2186   while (_late_inlines.length() > 0) {
2187     if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2188       if (low_live_nodes < (uint)LiveNodeCountInliningCutoff * 8 / 10) {
2189         TracePhase tp(_t_incrInline_ideal);
2190         // PhaseIdealLoop is expensive so we only try it once we are
2191         // out of live nodes and we only try it again if the previous
2192         // helped got the number of nodes down significantly
2193         PhaseIdealLoop::optimize(igvn, LoopOptsNone);
2194         if (failing())  return;
2195         low_live_nodes = live_nodes();
2196         _major_progress = true;
2197       }
2198 
2199       if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2200         bool do_print_inlining = print_inlining() || print_intrinsics();
2201         if (do_print_inlining || log() != nullptr) {
2202           // Print inlining message for candidates that we couldn't inline for lack of space.
2203           for (int i = 0; i < _late_inlines.length(); i++) {
2204             CallGenerator* cg = _late_inlines.at(i);
2205             const char* msg = "live nodes > LiveNodeCountInliningCutoff";
2206             if (do_print_inlining) {
2207               inline_printer()->record(cg->method(), cg->call_node()->jvms(), InliningResult::FAILURE, msg);
2208             }
2209             log_late_inline_failure(cg, msg);
2210           }
2211         }
2212         break; // finish
2213       }
2214     }
2215 
2216     igvn_worklist()->ensure_empty(); // should be done with igvn
2217 
2218     while (inline_incrementally_one()) {
2219       assert(!failing_internal() || failure_is_artificial(), "inconsistent");
2220     }
2221     if (failing())  return;
2222 
2223     inline_incrementally_cleanup(igvn);
2224 
2225     print_method(PHASE_INCREMENTAL_INLINE_STEP, 3);
2226 
2227     if (failing())  return;
2228 
2229     if (_late_inlines.length() == 0) {
2230       break; // no more progress
2231     }
2232   }
2233 
2234   igvn_worklist()->ensure_empty(); // should be done with igvn
2235 
2236   if (_string_late_inlines.length() > 0) {
2237     assert(has_stringbuilder(), "inconsistent");
2238 
2239     inline_string_calls(false);
2240 
2241     if (failing())  return;
2242 
2243     inline_incrementally_cleanup(igvn);
2244   }
2245 
2246   set_inlining_incrementally(false);
2247 }
2248 
2249 void Compile::process_late_inline_calls_no_inline(PhaseIterGVN& igvn) {
2250   // "inlining_incrementally() == false" is used to signal that no inlining is allowed
2251   // (see LateInlineVirtualCallGenerator::do_late_inline_check() for details).
2252   // Tracking and verification of modified nodes is disabled by setting "_modified_nodes == nullptr"
2253   // as if "inlining_incrementally() == true" were set.
2254   assert(inlining_incrementally() == false, "not allowed");
2255   assert(_modified_nodes == nullptr, "not allowed");
2256   assert(_late_inlines.length() > 0, "sanity");
2257 
2258   while (_late_inlines.length() > 0) {
2259     igvn_worklist()->ensure_empty(); // should be done with igvn
2260 
2261     while (inline_incrementally_one()) {
2262       assert(!failing_internal() || failure_is_artificial(), "inconsistent");
2263     }
2264     if (failing())  return;
2265 
2266     inline_incrementally_cleanup(igvn);
2267   }
2268 }
2269 
2270 bool Compile::optimize_loops(PhaseIterGVN& igvn, LoopOptsMode mode) {
2271   if (_loop_opts_cnt > 0) {
2272     while (major_progress() && (_loop_opts_cnt > 0)) {
2273       TracePhase tp(_t_idealLoop);
2274       PhaseIdealLoop::optimize(igvn, mode);
2275       _loop_opts_cnt--;
2276       if (failing())  return false;
2277       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
2278     }
2279   }
2280   return true;
2281 }
2282 
2283 // Remove edges from "root" to each SafePoint at a backward branch.
2284 // They were inserted during parsing (see add_safepoint()) to make
2285 // infinite loops without calls or exceptions visible to root, i.e.,
2286 // useful.
2287 void Compile::remove_root_to_sfpts_edges(PhaseIterGVN& igvn) {
2288   Node *r = root();
2289   if (r != nullptr) {
2290     for (uint i = r->req(); i < r->len(); ++i) {
2291       Node *n = r->in(i);
2292       if (n != nullptr && n->is_SafePoint()) {
2293         r->rm_prec(i);
2294         if (n->outcnt() == 0) {
2295           igvn.remove_dead_node(n);
2296         }
2297         --i;
2298       }
2299     }
2300     // Parsing may have added top inputs to the root node (Path
2301     // leading to the Halt node proven dead). Make sure we get a
2302     // chance to clean them up.
2303     igvn._worklist.push(r);
2304     igvn.optimize();
2305   }
2306 }
2307 
2308 //------------------------------Optimize---------------------------------------
2309 // Given a graph, optimize it.
2310 void Compile::Optimize() {
2311   TracePhase tp(_t_optimizer);
2312 
2313 #ifndef PRODUCT
2314   if (env()->break_at_compile()) {
2315     BREAKPOINT;
2316   }
2317 
2318 #endif
2319 
2320   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
2321 #ifdef ASSERT
2322   bs->verify_gc_barriers(this, BarrierSetC2::BeforeOptimize);
2323 #endif
2324 
2325   ResourceMark rm;
2326 
2327   NOT_PRODUCT( verify_graph_edges(); )
2328 
2329   print_method(PHASE_AFTER_PARSING, 1);
2330 
2331  {
2332   // Iterative Global Value Numbering, including ideal transforms
2333   PhaseIterGVN igvn;
2334 #ifdef ASSERT
2335   _modified_nodes = new (comp_arena()) Unique_Node_List(comp_arena());
2336 #endif
2337   {
2338     TracePhase tp(_t_iterGVN);
2339     igvn.optimize();
2340   }
2341 
2342   if (failing())  return;
2343 
2344   print_method(PHASE_ITER_GVN1, 2);
2345 
2346   process_for_unstable_if_traps(igvn);
2347 
2348   if (failing())  return;
2349 
2350   inline_incrementally(igvn);
2351 
2352   print_method(PHASE_INCREMENTAL_INLINE, 2);
2353 
2354   if (failing())  return;
2355 
2356   if (eliminate_boxing()) {
2357     // Inline valueOf() methods now.
2358     inline_boxing_calls(igvn);
2359 
2360     if (failing())  return;
2361 
2362     if (AlwaysIncrementalInline || StressIncrementalInlining) {
2363       inline_incrementally(igvn);
2364     }
2365 
2366     print_method(PHASE_INCREMENTAL_BOXING_INLINE, 2);
2367 
2368     if (failing())  return;
2369   }
2370 
2371   // Remove the speculative part of types and clean up the graph from
2372   // the extra CastPP nodes whose only purpose is to carry them. Do
2373   // that early so that optimizations are not disrupted by the extra
2374   // CastPP nodes.
2375   remove_speculative_types(igvn);
2376 
2377   if (failing())  return;
2378 
2379   // No more new expensive nodes will be added to the list from here
2380   // so keep only the actual candidates for optimizations.
2381   cleanup_expensive_nodes(igvn);
2382 
2383   if (failing())  return;
2384 
2385   assert(EnableVectorSupport || !has_vbox_nodes(), "sanity");
2386   if (EnableVectorSupport && has_vbox_nodes()) {
2387     TracePhase tp(_t_vector);
2388     PhaseVector pv(igvn);
2389     pv.optimize_vector_boxes();
2390     if (failing())  return;
2391     print_method(PHASE_ITER_GVN_AFTER_VECTOR, 2);
2392   }
2393   assert(!has_vbox_nodes(), "sanity");
2394 
2395   if (!failing() && RenumberLiveNodes && live_nodes() + NodeLimitFudgeFactor < unique()) {
2396     Compile::TracePhase tp(_t_renumberLive);
2397     igvn_worklist()->ensure_empty(); // should be done with igvn
2398     {
2399       ResourceMark rm;
2400       PhaseRenumberLive prl(initial_gvn(), *igvn_worklist());
2401     }
2402     igvn.reset();
2403     igvn.optimize();
2404     if (failing()) return;
2405   }
2406 
2407   // Now that all inlining is over and no PhaseRemoveUseless will run, cut edge from root to loop
2408   // safepoints
2409   remove_root_to_sfpts_edges(igvn);
2410 
2411   if (failing())  return;
2412 
2413   if (has_loops()) {
2414     print_method(PHASE_BEFORE_LOOP_OPTS, 2);
2415   }
2416 
2417   // Perform escape analysis
2418   if (do_escape_analysis() && ConnectionGraph::has_candidates(this)) {
2419     if (has_loops()) {
2420       // Cleanup graph (remove dead nodes).
2421       TracePhase tp(_t_idealLoop);
2422       PhaseIdealLoop::optimize(igvn, LoopOptsMaxUnroll);
2423       if (failing())  return;
2424     }
2425     bool progress;
2426     print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
2427     do {
2428       ConnectionGraph::do_analysis(this, &igvn);
2429 
2430       if (failing())  return;
2431 
2432       int mcount = macro_count(); // Record number of allocations and locks before IGVN
2433 
2434       // Optimize out fields loads from scalar replaceable allocations.
2435       igvn.optimize();
2436       print_method(PHASE_ITER_GVN_AFTER_EA, 2);
2437 
2438       if (failing()) return;
2439 
2440       if (congraph() != nullptr && macro_count() > 0) {
2441         TracePhase tp(_t_macroEliminate);
2442         PhaseMacroExpand mexp(igvn);
2443         mexp.eliminate_macro_nodes();
2444         if (failing()) return;
2445         print_method(PHASE_AFTER_MACRO_ELIMINATION, 2);
2446 
2447         igvn.set_delay_transform(false);
2448         igvn.optimize();
2449         if (failing()) return;
2450 
2451         print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
2452       }
2453 
2454       ConnectionGraph::verify_ram_nodes(this, root());
2455       if (failing())  return;
2456 
2457       progress = do_iterative_escape_analysis() &&
2458                  (macro_count() < mcount) &&
2459                  ConnectionGraph::has_candidates(this);
2460       // Try again if candidates exist and made progress
2461       // by removing some allocations and/or locks.
2462     } while (progress);
2463   }
2464 
2465   // Loop transforms on the ideal graph.  Range Check Elimination,
2466   // peeling, unrolling, etc.
2467 
2468   // Set loop opts counter
2469   if((_loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
2470     {
2471       TracePhase tp(_t_idealLoop);
2472       PhaseIdealLoop::optimize(igvn, LoopOptsDefault);
2473       _loop_opts_cnt--;
2474       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP1, 2);
2475       if (failing())  return;
2476     }
2477     // Loop opts pass if partial peeling occurred in previous pass
2478     if(PartialPeelLoop && major_progress() && (_loop_opts_cnt > 0)) {
2479       TracePhase tp(_t_idealLoop);
2480       PhaseIdealLoop::optimize(igvn, LoopOptsSkipSplitIf);
2481       _loop_opts_cnt--;
2482       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP2, 2);
2483       if (failing())  return;
2484     }
2485     // Loop opts pass for loop-unrolling before CCP
2486     if(major_progress() && (_loop_opts_cnt > 0)) {
2487       TracePhase tp(_t_idealLoop);
2488       PhaseIdealLoop::optimize(igvn, LoopOptsSkipSplitIf);
2489       _loop_opts_cnt--;
2490       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP3, 2);
2491     }
2492     if (!failing()) {
2493       // Verify that last round of loop opts produced a valid graph
2494       PhaseIdealLoop::verify(igvn);
2495     }
2496   }
2497   if (failing())  return;
2498 
2499   // Conditional Constant Propagation;
2500   print_method(PHASE_BEFORE_CCP1, 2);
2501   PhaseCCP ccp( &igvn );
2502   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
2503   {
2504     TracePhase tp(_t_ccp);
2505     ccp.do_transform();
2506   }
2507   print_method(PHASE_CCP1, 2);
2508 
2509   assert( true, "Break here to ccp.dump_old2new_map()");
2510 
2511   // Iterative Global Value Numbering, including ideal transforms
2512   {
2513     TracePhase tp(_t_iterGVN2);
2514     igvn.reset_from_igvn(&ccp);
2515     igvn.optimize();
2516   }
2517   print_method(PHASE_ITER_GVN2, 2);
2518 
2519   if (failing())  return;
2520 
2521   // Loop transforms on the ideal graph.  Range Check Elimination,
2522   // peeling, unrolling, etc.
2523   if (!optimize_loops(igvn, LoopOptsDefault)) {
2524     return;
2525   }
2526 
2527   if (failing())  return;
2528 
2529   C->clear_major_progress(); // ensure that major progress is now clear
2530 
2531   process_for_post_loop_opts_igvn(igvn);
2532 
2533   process_for_merge_stores_igvn(igvn);
2534 
2535   if (failing())  return;
2536 
2537 #ifdef ASSERT
2538   bs->verify_gc_barriers(this, BarrierSetC2::BeforeMacroExpand);
2539 #endif
2540 
2541   {
2542     TracePhase tp(_t_macroExpand);
2543     print_method(PHASE_BEFORE_MACRO_EXPANSION, 3);
2544     PhaseMacroExpand  mex(igvn);
2545     // Do not allow new macro nodes once we start to eliminate and expand
2546     C->reset_allow_macro_nodes();
2547     // Last attempt to eliminate macro nodes before expand
2548     mex.eliminate_macro_nodes();
2549     if (failing()) {
2550       return;
2551     }
2552     mex.eliminate_opaque_looplimit_macro_nodes();
2553     if (failing()) {
2554       return;
2555     }
2556     print_method(PHASE_AFTER_MACRO_ELIMINATION, 2);
2557     if (mex.expand_macro_nodes()) {
2558       assert(failing(), "must bail out w/ explicit message");
2559       return;
2560     }
2561     print_method(PHASE_AFTER_MACRO_EXPANSION, 2);
2562   }
2563 
2564   {
2565     TracePhase tp(_t_barrierExpand);
2566     if (bs->expand_barriers(this, igvn)) {
2567       assert(failing(), "must bail out w/ explicit message");
2568       return;
2569     }
2570     print_method(PHASE_BARRIER_EXPANSION, 2);
2571   }
2572 
2573   if (C->max_vector_size() > 0) {
2574     C->optimize_logic_cones(igvn);
2575     igvn.optimize();
2576     if (failing()) return;
2577   }
2578 
2579   DEBUG_ONLY( _modified_nodes = nullptr; )
2580 
2581   assert(igvn._worklist.size() == 0, "not empty");
2582 
2583   assert(_late_inlines.length() == 0 || IncrementalInlineMH || IncrementalInlineVirtual, "not empty");
2584 
2585   if (_late_inlines.length() > 0) {
2586     // More opportunities to optimize virtual and MH calls.
2587     // Though it's maybe too late to perform inlining, strength-reducing them to direct calls is still an option.
2588     process_late_inline_calls_no_inline(igvn);
2589     if (failing())  return;
2590   }
2591  } // (End scope of igvn; run destructor if necessary for asserts.)
2592 
2593  check_no_dead_use();
2594 
2595  // We will never use the NodeHash table any more. Clear it so that final_graph_reshaping does not have
2596  // to remove hashes to unlock nodes for modifications.
2597  C->node_hash()->clear();
2598 
2599  // A method with only infinite loops has no edges entering loops from root
2600  {
2601    TracePhase tp(_t_graphReshaping);
2602    if (final_graph_reshaping()) {
2603      assert(failing(), "must bail out w/ explicit message");
2604      return;
2605    }
2606  }
2607 
2608  print_method(PHASE_OPTIMIZE_FINISHED, 2);
2609  DEBUG_ONLY(set_phase_optimize_finished();)
2610 }
2611 
2612 #ifdef ASSERT
2613 void Compile::check_no_dead_use() const {
2614   ResourceMark rm;
2615   Unique_Node_List wq;
2616   wq.push(root());
2617   for (uint i = 0; i < wq.size(); ++i) {
2618     Node* n = wq.at(i);
2619     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
2620       Node* u = n->fast_out(j);
2621       if (u->outcnt() == 0 && !u->is_Con()) {
2622         u->dump();
2623         fatal("no reachable node should have no use");
2624       }
2625       wq.push(u);
2626     }
2627   }
2628 }
2629 #endif
2630 
2631 void Compile::inline_vector_reboxing_calls() {
2632   if (C->_vector_reboxing_late_inlines.length() > 0) {
2633     _late_inlines_pos = C->_late_inlines.length();
2634     while (_vector_reboxing_late_inlines.length() > 0) {
2635       CallGenerator* cg = _vector_reboxing_late_inlines.pop();
2636       cg->do_late_inline();
2637       if (failing())  return;
2638       print_method(PHASE_INLINE_VECTOR_REBOX, 3, cg->call_node());
2639     }
2640     _vector_reboxing_late_inlines.trunc_to(0);
2641   }
2642 }
2643 
2644 bool Compile::has_vbox_nodes() {
2645   if (C->_vector_reboxing_late_inlines.length() > 0) {
2646     return true;
2647   }
2648   for (int macro_idx = C->macro_count() - 1; macro_idx >= 0; macro_idx--) {
2649     Node * n = C->macro_node(macro_idx);
2650     assert(n->is_macro(), "only macro nodes expected here");
2651     if (n->Opcode() == Op_VectorUnbox || n->Opcode() == Op_VectorBox || n->Opcode() == Op_VectorBoxAllocate) {
2652       return true;
2653     }
2654   }
2655   return false;
2656 }
2657 
2658 //---------------------------- Bitwise operation packing optimization ---------------------------
2659 
2660 static bool is_vector_unary_bitwise_op(Node* n) {
2661   return n->Opcode() == Op_XorV &&
2662          VectorNode::is_vector_bitwise_not_pattern(n);
2663 }
2664 
2665 static bool is_vector_binary_bitwise_op(Node* n) {
2666   switch (n->Opcode()) {
2667     case Op_AndV:
2668     case Op_OrV:
2669       return true;
2670 
2671     case Op_XorV:
2672       return !is_vector_unary_bitwise_op(n);
2673 
2674     default:
2675       return false;
2676   }
2677 }
2678 
2679 static bool is_vector_ternary_bitwise_op(Node* n) {
2680   return n->Opcode() == Op_MacroLogicV;
2681 }
2682 
2683 static bool is_vector_bitwise_op(Node* n) {
2684   return is_vector_unary_bitwise_op(n)  ||
2685          is_vector_binary_bitwise_op(n) ||
2686          is_vector_ternary_bitwise_op(n);
2687 }
2688 
2689 static bool is_vector_bitwise_cone_root(Node* n) {
2690   if (n->bottom_type()->isa_vectmask() || !is_vector_bitwise_op(n)) {
2691     return false;
2692   }
2693   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2694     if (is_vector_bitwise_op(n->fast_out(i))) {
2695       return false;
2696     }
2697   }
2698   return true;
2699 }
2700 
2701 static uint collect_unique_inputs(Node* n, Unique_Node_List& inputs) {
2702   uint cnt = 0;
2703   if (is_vector_bitwise_op(n)) {
2704     uint inp_cnt = n->is_predicated_vector() ? n->req()-1 : n->req();
2705     if (VectorNode::is_vector_bitwise_not_pattern(n)) {
2706       for (uint i = 1; i < inp_cnt; i++) {
2707         Node* in = n->in(i);
2708         bool skip = VectorNode::is_all_ones_vector(in);
2709         if (!skip && !inputs.member(in)) {
2710           inputs.push(in);
2711           cnt++;
2712         }
2713       }
2714       assert(cnt <= 1, "not unary");
2715     } else {
2716       uint last_req = inp_cnt;
2717       if (is_vector_ternary_bitwise_op(n)) {
2718         last_req = inp_cnt - 1; // skip last input
2719       }
2720       for (uint i = 1; i < last_req; i++) {
2721         Node* def = n->in(i);
2722         if (!inputs.member(def)) {
2723           inputs.push(def);
2724           cnt++;
2725         }
2726       }
2727     }
2728   } else { // not a bitwise operations
2729     if (!inputs.member(n)) {
2730       inputs.push(n);
2731       cnt++;
2732     }
2733   }
2734   return cnt;
2735 }
2736 
2737 void Compile::collect_logic_cone_roots(Unique_Node_List& list) {
2738   Unique_Node_List useful_nodes;
2739   C->identify_useful_nodes(useful_nodes);
2740 
2741   for (uint i = 0; i < useful_nodes.size(); i++) {
2742     Node* n = useful_nodes.at(i);
2743     if (is_vector_bitwise_cone_root(n)) {
2744       list.push(n);
2745     }
2746   }
2747 }
2748 
2749 Node* Compile::xform_to_MacroLogicV(PhaseIterGVN& igvn,
2750                                     const TypeVect* vt,
2751                                     Unique_Node_List& partition,
2752                                     Unique_Node_List& inputs) {
2753   assert(partition.size() == 2 || partition.size() == 3, "not supported");
2754   assert(inputs.size()    == 2 || inputs.size()    == 3, "not supported");
2755   assert(Matcher::match_rule_supported_vector(Op_MacroLogicV, vt->length(), vt->element_basic_type()), "not supported");
2756 
2757   Node* in1 = inputs.at(0);
2758   Node* in2 = inputs.at(1);
2759   Node* in3 = (inputs.size() == 3 ? inputs.at(2) : in2);
2760 
2761   uint func = compute_truth_table(partition, inputs);
2762 
2763   Node* pn = partition.at(partition.size() - 1);
2764   Node* mask = pn->is_predicated_vector() ? pn->in(pn->req()-1) : nullptr;
2765   return igvn.transform(MacroLogicVNode::make(igvn, in1, in2, in3, mask, func, vt));
2766 }
2767 
2768 static uint extract_bit(uint func, uint pos) {
2769   return (func & (1 << pos)) >> pos;
2770 }
2771 
2772 //
2773 //  A macro logic node represents a truth table. It has 4 inputs,
2774 //  First three inputs corresponds to 3 columns of a truth table
2775 //  and fourth input captures the logic function.
2776 //
2777 //  eg.  fn = (in1 AND in2) OR in3;
2778 //
2779 //      MacroNode(in1,in2,in3,fn)
2780 //
2781 //  -----------------
2782 //  in1 in2 in3  fn
2783 //  -----------------
2784 //  0    0   0    0
2785 //  0    0   1    1
2786 //  0    1   0    0
2787 //  0    1   1    1
2788 //  1    0   0    0
2789 //  1    0   1    1
2790 //  1    1   0    1
2791 //  1    1   1    1
2792 //
2793 
2794 uint Compile::eval_macro_logic_op(uint func, uint in1 , uint in2, uint in3) {
2795   int res = 0;
2796   for (int i = 0; i < 8; i++) {
2797     int bit1 = extract_bit(in1, i);
2798     int bit2 = extract_bit(in2, i);
2799     int bit3 = extract_bit(in3, i);
2800 
2801     int func_bit_pos = (bit1 << 2 | bit2 << 1 | bit3);
2802     int func_bit = extract_bit(func, func_bit_pos);
2803 
2804     res |= func_bit << i;
2805   }
2806   return res;
2807 }
2808 
2809 static uint eval_operand(Node* n, HashTable<Node*,uint>& eval_map) {
2810   assert(n != nullptr, "");
2811   assert(eval_map.contains(n), "absent");
2812   return *(eval_map.get(n));
2813 }
2814 
2815 static void eval_operands(Node* n,
2816                           uint& func1, uint& func2, uint& func3,
2817                           HashTable<Node*,uint>& eval_map) {
2818   assert(is_vector_bitwise_op(n), "");
2819 
2820   if (is_vector_unary_bitwise_op(n)) {
2821     Node* opnd = n->in(1);
2822     if (VectorNode::is_vector_bitwise_not_pattern(n) && VectorNode::is_all_ones_vector(opnd)) {
2823       opnd = n->in(2);
2824     }
2825     func1 = eval_operand(opnd, eval_map);
2826   } else if (is_vector_binary_bitwise_op(n)) {
2827     func1 = eval_operand(n->in(1), eval_map);
2828     func2 = eval_operand(n->in(2), eval_map);
2829   } else {
2830     assert(is_vector_ternary_bitwise_op(n), "unknown operation");
2831     func1 = eval_operand(n->in(1), eval_map);
2832     func2 = eval_operand(n->in(2), eval_map);
2833     func3 = eval_operand(n->in(3), eval_map);
2834   }
2835 }
2836 
2837 uint Compile::compute_truth_table(Unique_Node_List& partition, Unique_Node_List& inputs) {
2838   assert(inputs.size() <= 3, "sanity");
2839   ResourceMark rm;
2840   uint res = 0;
2841   HashTable<Node*,uint> eval_map;
2842 
2843   // Populate precomputed functions for inputs.
2844   // Each input corresponds to one column of 3 input truth-table.
2845   uint input_funcs[] = { 0xAA,   // (_, _, c) -> c
2846                          0xCC,   // (_, b, _) -> b
2847                          0xF0 }; // (a, _, _) -> a
2848   for (uint i = 0; i < inputs.size(); i++) {
2849     eval_map.put(inputs.at(i), input_funcs[2-i]);
2850   }
2851 
2852   for (uint i = 0; i < partition.size(); i++) {
2853     Node* n = partition.at(i);
2854 
2855     uint func1 = 0, func2 = 0, func3 = 0;
2856     eval_operands(n, func1, func2, func3, eval_map);
2857 
2858     switch (n->Opcode()) {
2859       case Op_OrV:
2860         assert(func3 == 0, "not binary");
2861         res = func1 | func2;
2862         break;
2863       case Op_AndV:
2864         assert(func3 == 0, "not binary");
2865         res = func1 & func2;
2866         break;
2867       case Op_XorV:
2868         if (VectorNode::is_vector_bitwise_not_pattern(n)) {
2869           assert(func2 == 0 && func3 == 0, "not unary");
2870           res = (~func1) & 0xFF;
2871         } else {
2872           assert(func3 == 0, "not binary");
2873           res = func1 ^ func2;
2874         }
2875         break;
2876       case Op_MacroLogicV:
2877         // Ordering of inputs may change during evaluation of sub-tree
2878         // containing MacroLogic node as a child node, thus a re-evaluation
2879         // makes sure that function is evaluated in context of current
2880         // inputs.
2881         res = eval_macro_logic_op(n->in(4)->get_int(), func1, func2, func3);
2882         break;
2883 
2884       default: assert(false, "not supported: %s", n->Name());
2885     }
2886     assert(res <= 0xFF, "invalid");
2887     eval_map.put(n, res);
2888   }
2889   return res;
2890 }
2891 
2892 // Criteria under which nodes gets packed into a macro logic node:-
2893 //  1) Parent and both child nodes are all unmasked or masked with
2894 //     same predicates.
2895 //  2) Masked parent can be packed with left child if it is predicated
2896 //     and both have same predicates.
2897 //  3) Masked parent can be packed with right child if its un-predicated
2898 //     or has matching predication condition.
2899 //  4) An unmasked parent can be packed with an unmasked child.
2900 bool Compile::compute_logic_cone(Node* n, Unique_Node_List& partition, Unique_Node_List& inputs) {
2901   assert(partition.size() == 0, "not empty");
2902   assert(inputs.size() == 0, "not empty");
2903   if (is_vector_ternary_bitwise_op(n)) {
2904     return false;
2905   }
2906 
2907   bool is_unary_op = is_vector_unary_bitwise_op(n);
2908   if (is_unary_op) {
2909     assert(collect_unique_inputs(n, inputs) == 1, "not unary");
2910     return false; // too few inputs
2911   }
2912 
2913   bool pack_left_child = true;
2914   bool pack_right_child = true;
2915 
2916   bool left_child_LOP = is_vector_bitwise_op(n->in(1));
2917   bool right_child_LOP = is_vector_bitwise_op(n->in(2));
2918 
2919   int left_child_input_cnt = 0;
2920   int right_child_input_cnt = 0;
2921 
2922   bool parent_is_predicated = n->is_predicated_vector();
2923   bool left_child_predicated = n->in(1)->is_predicated_vector();
2924   bool right_child_predicated = n->in(2)->is_predicated_vector();
2925 
2926   Node* parent_pred = parent_is_predicated ? n->in(n->req()-1) : nullptr;
2927   Node* left_child_pred = left_child_predicated ? n->in(1)->in(n->in(1)->req()-1) : nullptr;
2928   Node* right_child_pred = right_child_predicated ? n->in(1)->in(n->in(1)->req()-1) : nullptr;
2929 
2930   do {
2931     if (pack_left_child && left_child_LOP &&
2932         ((!parent_is_predicated && !left_child_predicated) ||
2933         ((parent_is_predicated && left_child_predicated &&
2934           parent_pred == left_child_pred)))) {
2935        partition.push(n->in(1));
2936        left_child_input_cnt = collect_unique_inputs(n->in(1), inputs);
2937     } else {
2938        inputs.push(n->in(1));
2939        left_child_input_cnt = 1;
2940     }
2941 
2942     if (pack_right_child && right_child_LOP &&
2943         (!right_child_predicated ||
2944          (right_child_predicated && parent_is_predicated &&
2945           parent_pred == right_child_pred))) {
2946        partition.push(n->in(2));
2947        right_child_input_cnt = collect_unique_inputs(n->in(2), inputs);
2948     } else {
2949        inputs.push(n->in(2));
2950        right_child_input_cnt = 1;
2951     }
2952 
2953     if (inputs.size() > 3) {
2954       assert(partition.size() > 0, "");
2955       inputs.clear();
2956       partition.clear();
2957       if (left_child_input_cnt > right_child_input_cnt) {
2958         pack_left_child = false;
2959       } else {
2960         pack_right_child = false;
2961       }
2962     } else {
2963       break;
2964     }
2965   } while(true);
2966 
2967   if(partition.size()) {
2968     partition.push(n);
2969   }
2970 
2971   return (partition.size() == 2 || partition.size() == 3) &&
2972          (inputs.size()    == 2 || inputs.size()    == 3);
2973 }
2974 
2975 void Compile::process_logic_cone_root(PhaseIterGVN &igvn, Node *n, VectorSet &visited) {
2976   assert(is_vector_bitwise_op(n), "not a root");
2977 
2978   visited.set(n->_idx);
2979 
2980   // 1) Do a DFS walk over the logic cone.
2981   for (uint i = 1; i < n->req(); i++) {
2982     Node* in = n->in(i);
2983     if (!visited.test(in->_idx) && is_vector_bitwise_op(in)) {
2984       process_logic_cone_root(igvn, in, visited);
2985     }
2986   }
2987 
2988   // 2) Bottom up traversal: Merge node[s] with
2989   // the parent to form macro logic node.
2990   Unique_Node_List partition;
2991   Unique_Node_List inputs;
2992   if (compute_logic_cone(n, partition, inputs)) {
2993     const TypeVect* vt = n->bottom_type()->is_vect();
2994     Node* pn = partition.at(partition.size() - 1);
2995     Node* mask = pn->is_predicated_vector() ? pn->in(pn->req()-1) : nullptr;
2996     if (mask == nullptr ||
2997         Matcher::match_rule_supported_vector_masked(Op_MacroLogicV, vt->length(), vt->element_basic_type())) {
2998       Node* macro_logic = xform_to_MacroLogicV(igvn, vt, partition, inputs);
2999       VectorNode::trace_new_vector(macro_logic, "MacroLogic");
3000       igvn.replace_node(n, macro_logic);
3001     }
3002   }
3003 }
3004 
3005 void Compile::optimize_logic_cones(PhaseIterGVN &igvn) {
3006   ResourceMark rm;
3007   if (Matcher::match_rule_supported(Op_MacroLogicV)) {
3008     Unique_Node_List list;
3009     collect_logic_cone_roots(list);
3010 
3011     while (list.size() > 0) {
3012       Node* n = list.pop();
3013       const TypeVect* vt = n->bottom_type()->is_vect();
3014       bool supported = Matcher::match_rule_supported_vector(Op_MacroLogicV, vt->length(), vt->element_basic_type());
3015       if (supported) {
3016         VectorSet visited(comp_arena());
3017         process_logic_cone_root(igvn, n, visited);
3018       }
3019     }
3020   }
3021 }
3022 
3023 //------------------------------Code_Gen---------------------------------------
3024 // Given a graph, generate code for it
3025 void Compile::Code_Gen() {
3026   if (failing()) {
3027     return;
3028   }
3029 
3030   // Perform instruction selection.  You might think we could reclaim Matcher
3031   // memory PDQ, but actually the Matcher is used in generating spill code.
3032   // Internals of the Matcher (including some VectorSets) must remain live
3033   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
3034   // set a bit in reclaimed memory.
3035 
3036   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
3037   // nodes.  Mapping is only valid at the root of each matched subtree.
3038   NOT_PRODUCT( verify_graph_edges(); )
3039 
3040   Matcher matcher;
3041   _matcher = &matcher;
3042   {
3043     TracePhase tp(_t_matcher);
3044     matcher.match();
3045     if (failing()) {
3046       return;
3047     }
3048   }
3049   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
3050   // nodes.  Mapping is only valid at the root of each matched subtree.
3051   NOT_PRODUCT( verify_graph_edges(); )
3052 
3053   // If you have too many nodes, or if matching has failed, bail out
3054   check_node_count(0, "out of nodes matching instructions");
3055   if (failing()) {
3056     return;
3057   }
3058 
3059   print_method(PHASE_MATCHING, 2);
3060 
3061   // Build a proper-looking CFG
3062   PhaseCFG cfg(node_arena(), root(), matcher);
3063   if (failing()) {
3064     return;
3065   }
3066   _cfg = &cfg;
3067   {
3068     TracePhase tp(_t_scheduler);
3069     bool success = cfg.do_global_code_motion();
3070     if (!success) {
3071       return;
3072     }
3073 
3074     print_method(PHASE_GLOBAL_CODE_MOTION, 2);
3075     NOT_PRODUCT( verify_graph_edges(); )
3076     cfg.verify();
3077     if (failing()) {
3078       return;
3079     }
3080   }
3081 
3082   PhaseChaitin regalloc(unique(), cfg, matcher, false);
3083   _regalloc = &regalloc;
3084   {
3085     TracePhase tp(_t_registerAllocation);
3086     // Perform register allocation.  After Chaitin, use-def chains are
3087     // no longer accurate (at spill code) and so must be ignored.
3088     // Node->LRG->reg mappings are still accurate.
3089     _regalloc->Register_Allocate();
3090 
3091     // Bail out if the allocator builds too many nodes
3092     if (failing()) {
3093       return;
3094     }
3095 
3096     print_method(PHASE_REGISTER_ALLOCATION, 2);
3097   }
3098 
3099   // Prior to register allocation we kept empty basic blocks in case the
3100   // the allocator needed a place to spill.  After register allocation we
3101   // are not adding any new instructions.  If any basic block is empty, we
3102   // can now safely remove it.
3103   {
3104     TracePhase tp(_t_blockOrdering);
3105     cfg.remove_empty_blocks();
3106     if (do_freq_based_layout()) {
3107       PhaseBlockLayout layout(cfg);
3108     } else {
3109       cfg.set_loop_alignment();
3110     }
3111     cfg.fixup_flow();
3112     cfg.remove_unreachable_blocks();
3113     cfg.verify_dominator_tree();
3114     print_method(PHASE_BLOCK_ORDERING, 3);
3115   }
3116 
3117   // Apply peephole optimizations
3118   if( OptoPeephole ) {
3119     TracePhase tp(_t_peephole);
3120     PhasePeephole peep( _regalloc, cfg);
3121     peep.do_transform();
3122     print_method(PHASE_PEEPHOLE, 3);
3123   }
3124 
3125   // Do late expand if CPU requires this.
3126   if (Matcher::require_postalloc_expand) {
3127     TracePhase tp(_t_postalloc_expand);
3128     cfg.postalloc_expand(_regalloc);
3129     print_method(PHASE_POSTALLOC_EXPAND, 3);
3130   }
3131 
3132 #ifdef ASSERT
3133   {
3134     CompilationMemoryStatistic::do_test_allocations();
3135     if (failing()) return;
3136   }
3137 #endif
3138 
3139   // Convert Nodes to instruction bits in a buffer
3140   {
3141     TracePhase tp(_t_output);
3142     PhaseOutput output;
3143     output.Output();
3144     if (failing())  return;
3145     output.install();
3146     print_method(PHASE_FINAL_CODE, 1); // Compile::_output is not null here
3147   }
3148 
3149   // He's dead, Jim.
3150   _cfg     = (PhaseCFG*)((intptr_t)0xdeadbeef);
3151   _regalloc = (PhaseChaitin*)((intptr_t)0xdeadbeef);
3152 }
3153 
3154 //------------------------------Final_Reshape_Counts---------------------------
3155 // This class defines counters to help identify when a method
3156 // may/must be executed using hardware with only 24-bit precision.
3157 struct Final_Reshape_Counts : public StackObj {
3158   int  _call_count;             // count non-inlined 'common' calls
3159   int  _float_count;            // count float ops requiring 24-bit precision
3160   int  _double_count;           // count double ops requiring more precision
3161   int  _java_call_count;        // count non-inlined 'java' calls
3162   int  _inner_loop_count;       // count loops which need alignment
3163   VectorSet _visited;           // Visitation flags
3164   Node_List _tests;             // Set of IfNodes & PCTableNodes
3165 
3166   Final_Reshape_Counts() :
3167     _call_count(0), _float_count(0), _double_count(0),
3168     _java_call_count(0), _inner_loop_count(0) { }
3169 
3170   void inc_call_count  () { _call_count  ++; }
3171   void inc_float_count () { _float_count ++; }
3172   void inc_double_count() { _double_count++; }
3173   void inc_java_call_count() { _java_call_count++; }
3174   void inc_inner_loop_count() { _inner_loop_count++; }
3175 
3176   int  get_call_count  () const { return _call_count  ; }
3177   int  get_float_count () const { return _float_count ; }
3178   int  get_double_count() const { return _double_count; }
3179   int  get_java_call_count() const { return _java_call_count; }
3180   int  get_inner_loop_count() const { return _inner_loop_count; }
3181 };
3182 
3183 //------------------------------final_graph_reshaping_impl----------------------
3184 // Implement items 1-5 from final_graph_reshaping below.
3185 void Compile::final_graph_reshaping_impl(Node *n, Final_Reshape_Counts& frc, Unique_Node_List& dead_nodes) {
3186 
3187   if ( n->outcnt() == 0 ) return; // dead node
3188   uint nop = n->Opcode();
3189 
3190   // Check for 2-input instruction with "last use" on right input.
3191   // Swap to left input.  Implements item (2).
3192   if( n->req() == 3 &&          // two-input instruction
3193       n->in(1)->outcnt() > 1 && // left use is NOT a last use
3194       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
3195       n->in(2)->outcnt() == 1 &&// right use IS a last use
3196       !n->in(2)->is_Con() ) {   // right use is not a constant
3197     // Check for commutative opcode
3198     switch( nop ) {
3199     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddL:
3200     case Op_MaxI:  case Op_MaxL:  case Op_MaxF:  case Op_MaxD:
3201     case Op_MinI:  case Op_MinL:  case Op_MinF:  case Op_MinD:
3202     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulL:
3203     case Op_AndL:  case Op_XorL:  case Op_OrL:
3204     case Op_AndI:  case Op_XorI:  case Op_OrI: {
3205       // Move "last use" input to left by swapping inputs
3206       n->swap_edges(1, 2);
3207       break;
3208     }
3209     default:
3210       break;
3211     }
3212   }
3213 
3214 #ifdef ASSERT
3215   if( n->is_Mem() ) {
3216     int alias_idx = get_alias_index(n->as_Mem()->adr_type());
3217     assert( n->in(0) != nullptr || alias_idx != Compile::AliasIdxRaw ||
3218             // oop will be recorded in oop map if load crosses safepoint
3219             (n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
3220                               LoadNode::is_immutable_value(n->in(MemNode::Address)))),
3221             "raw memory operations should have control edge");
3222   }
3223   if (n->is_MemBar()) {
3224     MemBarNode* mb = n->as_MemBar();
3225     if (mb->trailing_store() || mb->trailing_load_store()) {
3226       assert(mb->leading_membar()->trailing_membar() == mb, "bad membar pair");
3227       Node* mem = BarrierSet::barrier_set()->barrier_set_c2()->step_over_gc_barrier(mb->in(MemBarNode::Precedent));
3228       assert((mb->trailing_store() && mem->is_Store() && mem->as_Store()->is_release()) ||
3229              (mb->trailing_load_store() && mem->is_LoadStore()), "missing mem op");
3230     } else if (mb->leading()) {
3231       assert(mb->trailing_membar()->leading_membar() == mb, "bad membar pair");
3232     }
3233   }
3234 #endif
3235   // Count FPU ops and common calls, implements item (3)
3236   bool gc_handled = BarrierSet::barrier_set()->barrier_set_c2()->final_graph_reshaping(this, n, nop, dead_nodes);
3237   if (!gc_handled) {
3238     final_graph_reshaping_main_switch(n, frc, nop, dead_nodes);
3239   }
3240 
3241   // Collect CFG split points
3242   if (n->is_MultiBranch() && !n->is_RangeCheck()) {
3243     frc._tests.push(n);
3244   }
3245 }
3246 
3247 void Compile::handle_div_mod_op(Node* n, BasicType bt, bool is_unsigned) {
3248   if (!UseDivMod) {
3249     return;
3250   }
3251 
3252   // Check if "a % b" and "a / b" both exist
3253   Node* d = n->find_similar(Op_DivIL(bt, is_unsigned));
3254   if (d == nullptr) {
3255     return;
3256   }
3257 
3258   // Replace them with a fused divmod if supported
3259   if (Matcher::has_match_rule(Op_DivModIL(bt, is_unsigned))) {
3260     DivModNode* divmod = DivModNode::make(n, bt, is_unsigned);
3261     // If the divisor input for a Div (or Mod etc.) is not zero, then the control input of the Div is set to zero.
3262     // It could be that the divisor input is found not zero because its type is narrowed down by a CastII in the
3263     // subgraph for that input. Range check CastIIs are removed during final graph reshape. To preserve the dependency
3264     // carried by a CastII, precedence edges are added to the Div node. We need to transfer the precedence edges to the
3265     // DivMod node so the dependency is not lost.
3266     divmod->add_prec_from(n);
3267     divmod->add_prec_from(d);
3268     d->subsume_by(divmod->div_proj(), this);
3269     n->subsume_by(divmod->mod_proj(), this);
3270   } else {
3271     // Replace "a % b" with "a - ((a / b) * b)"
3272     Node* mult = MulNode::make(d, d->in(2), bt);
3273     Node* sub = SubNode::make(d->in(1), mult, bt);
3274     n->subsume_by(sub, this);
3275   }
3276 }
3277 
3278 void Compile::final_graph_reshaping_main_switch(Node* n, Final_Reshape_Counts& frc, uint nop, Unique_Node_List& dead_nodes) {
3279   switch( nop ) {
3280   // Count all float operations that may use FPU
3281   case Op_AddF:
3282   case Op_SubF:
3283   case Op_MulF:
3284   case Op_DivF:
3285   case Op_NegF:
3286   case Op_ModF:
3287   case Op_ConvI2F:
3288   case Op_ConF:
3289   case Op_CmpF:
3290   case Op_CmpF3:
3291   case Op_StoreF:
3292   case Op_LoadF:
3293   // case Op_ConvL2F: // longs are split into 32-bit halves
3294     frc.inc_float_count();
3295     break;
3296 
3297   case Op_ConvF2D:
3298   case Op_ConvD2F:
3299     frc.inc_float_count();
3300     frc.inc_double_count();
3301     break;
3302 
3303   // Count all double operations that may use FPU
3304   case Op_AddD:
3305   case Op_SubD:
3306   case Op_MulD:
3307   case Op_DivD:
3308   case Op_NegD:
3309   case Op_ModD:
3310   case Op_ConvI2D:
3311   case Op_ConvD2I:
3312   // case Op_ConvL2D: // handled by leaf call
3313   // case Op_ConvD2L: // handled by leaf call
3314   case Op_ConD:
3315   case Op_CmpD:
3316   case Op_CmpD3:
3317   case Op_StoreD:
3318   case Op_LoadD:
3319   case Op_LoadD_unaligned:
3320     frc.inc_double_count();
3321     break;
3322   case Op_Opaque1:              // Remove Opaque Nodes before matching
3323     n->subsume_by(n->in(1), this);
3324     break;
3325   case Op_CallLeafPure: {
3326     // If the pure call is not supported, then lower to a CallLeaf.
3327     if (!Matcher::match_rule_supported(Op_CallLeafPure)) {
3328       CallNode* call = n->as_Call();
3329       CallNode* new_call = new CallLeafNode(call->tf(), call->entry_point(),
3330                                             call->_name, TypeRawPtr::BOTTOM);
3331       new_call->init_req(TypeFunc::Control, call->in(TypeFunc::Control));
3332       new_call->init_req(TypeFunc::I_O, C->top());
3333       new_call->init_req(TypeFunc::Memory, C->top());
3334       new_call->init_req(TypeFunc::ReturnAdr, C->top());
3335       new_call->init_req(TypeFunc::FramePtr, C->top());
3336       for (unsigned int i = TypeFunc::Parms; i < call->tf()->domain()->cnt(); i++) {
3337         new_call->init_req(i, call->in(i));
3338       }
3339       n->subsume_by(new_call, this);
3340     }
3341     frc.inc_call_count();
3342     break;
3343   }
3344   case Op_CallStaticJava:
3345   case Op_CallJava:
3346   case Op_CallDynamicJava:
3347     frc.inc_java_call_count(); // Count java call site;
3348   case Op_CallRuntime:
3349   case Op_CallLeaf:
3350   case Op_CallLeafVector:
3351   case Op_CallLeafNoFP: {
3352     assert (n->is_Call(), "");
3353     CallNode *call = n->as_Call();
3354     // Count call sites where the FP mode bit would have to be flipped.
3355     // Do not count uncommon runtime calls:
3356     // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
3357     // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
3358     if (!call->is_CallStaticJava() || !call->as_CallStaticJava()->_name) {
3359       frc.inc_call_count();   // Count the call site
3360     } else {                  // See if uncommon argument is shared
3361       Node *n = call->in(TypeFunc::Parms);
3362       int nop = n->Opcode();
3363       // Clone shared simple arguments to uncommon calls, item (1).
3364       if (n->outcnt() > 1 &&
3365           !n->is_Proj() &&
3366           nop != Op_CreateEx &&
3367           nop != Op_CheckCastPP &&
3368           nop != Op_DecodeN &&
3369           nop != Op_DecodeNKlass &&
3370           !n->is_Mem() &&
3371           !n->is_Phi()) {
3372         Node *x = n->clone();
3373         call->set_req(TypeFunc::Parms, x);
3374       }
3375     }
3376     break;
3377   }
3378   case Op_StoreB:
3379   case Op_StoreC:
3380   case Op_StoreI:
3381   case Op_StoreL:
3382   case Op_CompareAndSwapB:
3383   case Op_CompareAndSwapS:
3384   case Op_CompareAndSwapI:
3385   case Op_CompareAndSwapL:
3386   case Op_CompareAndSwapP:
3387   case Op_CompareAndSwapN:
3388   case Op_WeakCompareAndSwapB:
3389   case Op_WeakCompareAndSwapS:
3390   case Op_WeakCompareAndSwapI:
3391   case Op_WeakCompareAndSwapL:
3392   case Op_WeakCompareAndSwapP:
3393   case Op_WeakCompareAndSwapN:
3394   case Op_CompareAndExchangeB:
3395   case Op_CompareAndExchangeS:
3396   case Op_CompareAndExchangeI:
3397   case Op_CompareAndExchangeL:
3398   case Op_CompareAndExchangeP:
3399   case Op_CompareAndExchangeN:
3400   case Op_GetAndAddS:
3401   case Op_GetAndAddB:
3402   case Op_GetAndAddI:
3403   case Op_GetAndAddL:
3404   case Op_GetAndSetS:
3405   case Op_GetAndSetB:
3406   case Op_GetAndSetI:
3407   case Op_GetAndSetL:
3408   case Op_GetAndSetP:
3409   case Op_GetAndSetN:
3410   case Op_StoreP:
3411   case Op_StoreN:
3412   case Op_StoreNKlass:
3413   case Op_LoadB:
3414   case Op_LoadUB:
3415   case Op_LoadUS:
3416   case Op_LoadI:
3417   case Op_LoadKlass:
3418   case Op_LoadNKlass:
3419   case Op_LoadL:
3420   case Op_LoadL_unaligned:
3421   case Op_LoadP:
3422   case Op_LoadN:
3423   case Op_LoadRange:
3424   case Op_LoadS:
3425     break;
3426 
3427   case Op_AddP: {               // Assert sane base pointers
3428     Node *addp = n->in(AddPNode::Address);
3429     assert( !addp->is_AddP() ||
3430             addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
3431             addp->in(AddPNode::Base) == n->in(AddPNode::Base),
3432             "Base pointers must match (addp %u)", addp->_idx );
3433 #ifdef _LP64
3434     if ((UseCompressedOops || UseCompressedClassPointers) &&
3435         addp->Opcode() == Op_ConP &&
3436         addp == n->in(AddPNode::Base) &&
3437         n->in(AddPNode::Offset)->is_Con()) {
3438       // If the transformation of ConP to ConN+DecodeN is beneficial depends
3439       // on the platform and on the compressed oops mode.
3440       // Use addressing with narrow klass to load with offset on x86.
3441       // Some platforms can use the constant pool to load ConP.
3442       // Do this transformation here since IGVN will convert ConN back to ConP.
3443       const Type* t = addp->bottom_type();
3444       bool is_oop   = t->isa_oopptr() != nullptr;
3445       bool is_klass = t->isa_klassptr() != nullptr;
3446 
3447       if ((is_oop   && UseCompressedOops          && Matcher::const_oop_prefer_decode()  ) ||
3448           (is_klass && UseCompressedClassPointers && Matcher::const_klass_prefer_decode() &&
3449            t->isa_klassptr()->exact_klass()->is_in_encoding_range())) {
3450         Node* nn = nullptr;
3451 
3452         int op = is_oop ? Op_ConN : Op_ConNKlass;
3453 
3454         // Look for existing ConN node of the same exact type.
3455         Node* r  = root();
3456         uint cnt = r->outcnt();
3457         for (uint i = 0; i < cnt; i++) {
3458           Node* m = r->raw_out(i);
3459           if (m!= nullptr && m->Opcode() == op &&
3460               m->bottom_type()->make_ptr() == t) {
3461             nn = m;
3462             break;
3463           }
3464         }
3465         if (nn != nullptr) {
3466           // Decode a narrow oop to match address
3467           // [R12 + narrow_oop_reg<<3 + offset]
3468           if (is_oop) {
3469             nn = new DecodeNNode(nn, t);
3470           } else {
3471             nn = new DecodeNKlassNode(nn, t);
3472           }
3473           // Check for succeeding AddP which uses the same Base.
3474           // Otherwise we will run into the assertion above when visiting that guy.
3475           for (uint i = 0; i < n->outcnt(); ++i) {
3476             Node *out_i = n->raw_out(i);
3477             if (out_i && out_i->is_AddP() && out_i->in(AddPNode::Base) == addp) {
3478               out_i->set_req(AddPNode::Base, nn);
3479 #ifdef ASSERT
3480               for (uint j = 0; j < out_i->outcnt(); ++j) {
3481                 Node *out_j = out_i->raw_out(j);
3482                 assert(out_j == nullptr || !out_j->is_AddP() || out_j->in(AddPNode::Base) != addp,
3483                        "more than 2 AddP nodes in a chain (out_j %u)", out_j->_idx);
3484               }
3485 #endif
3486             }
3487           }
3488           n->set_req(AddPNode::Base, nn);
3489           n->set_req(AddPNode::Address, nn);
3490           if (addp->outcnt() == 0) {
3491             addp->disconnect_inputs(this);
3492           }
3493         }
3494       }
3495     }
3496 #endif
3497     break;
3498   }
3499 
3500   case Op_CastPP: {
3501     // Remove CastPP nodes to gain more freedom during scheduling but
3502     // keep the dependency they encode as control or precedence edges
3503     // (if control is set already) on memory operations. Some CastPP
3504     // nodes don't have a control (don't carry a dependency): skip
3505     // those.
3506     if (n->in(0) != nullptr) {
3507       ResourceMark rm;
3508       Unique_Node_List wq;
3509       wq.push(n);
3510       for (uint next = 0; next < wq.size(); ++next) {
3511         Node *m = wq.at(next);
3512         for (DUIterator_Fast imax, i = m->fast_outs(imax); i < imax; i++) {
3513           Node* use = m->fast_out(i);
3514           if (use->is_Mem() || use->is_EncodeNarrowPtr()) {
3515             use->ensure_control_or_add_prec(n->in(0));
3516           } else {
3517             switch(use->Opcode()) {
3518             case Op_AddP:
3519             case Op_DecodeN:
3520             case Op_DecodeNKlass:
3521             case Op_CheckCastPP:
3522             case Op_CastPP:
3523               wq.push(use);
3524               break;
3525             }
3526           }
3527         }
3528       }
3529     }
3530     const bool is_LP64 = LP64_ONLY(true) NOT_LP64(false);
3531     if (is_LP64 && n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
3532       Node* in1 = n->in(1);
3533       const Type* t = n->bottom_type();
3534       Node* new_in1 = in1->clone();
3535       new_in1->as_DecodeN()->set_type(t);
3536 
3537       if (!Matcher::narrow_oop_use_complex_address()) {
3538         //
3539         // x86, ARM and friends can handle 2 adds in addressing mode
3540         // and Matcher can fold a DecodeN node into address by using
3541         // a narrow oop directly and do implicit null check in address:
3542         //
3543         // [R12 + narrow_oop_reg<<3 + offset]
3544         // NullCheck narrow_oop_reg
3545         //
3546         // On other platforms (Sparc) we have to keep new DecodeN node and
3547         // use it to do implicit null check in address:
3548         //
3549         // decode_not_null narrow_oop_reg, base_reg
3550         // [base_reg + offset]
3551         // NullCheck base_reg
3552         //
3553         // Pin the new DecodeN node to non-null path on these platform (Sparc)
3554         // to keep the information to which null check the new DecodeN node
3555         // corresponds to use it as value in implicit_null_check().
3556         //
3557         new_in1->set_req(0, n->in(0));
3558       }
3559 
3560       n->subsume_by(new_in1, this);
3561       if (in1->outcnt() == 0) {
3562         in1->disconnect_inputs(this);
3563       }
3564     } else {
3565       n->subsume_by(n->in(1), this);
3566       if (n->outcnt() == 0) {
3567         n->disconnect_inputs(this);
3568       }
3569     }
3570     break;
3571   }
3572   case Op_CastII: {
3573     n->as_CastII()->remove_range_check_cast(this);
3574     break;
3575   }
3576 #ifdef _LP64
3577   case Op_CmpP:
3578     // Do this transformation here to preserve CmpPNode::sub() and
3579     // other TypePtr related Ideal optimizations (for example, ptr nullness).
3580     if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
3581       Node* in1 = n->in(1);
3582       Node* in2 = n->in(2);
3583       if (!in1->is_DecodeNarrowPtr()) {
3584         in2 = in1;
3585         in1 = n->in(2);
3586       }
3587       assert(in1->is_DecodeNarrowPtr(), "sanity");
3588 
3589       Node* new_in2 = nullptr;
3590       if (in2->is_DecodeNarrowPtr()) {
3591         assert(in2->Opcode() == in1->Opcode(), "must be same node type");
3592         new_in2 = in2->in(1);
3593       } else if (in2->Opcode() == Op_ConP) {
3594         const Type* t = in2->bottom_type();
3595         if (t == TypePtr::NULL_PTR) {
3596           assert(in1->is_DecodeN(), "compare klass to null?");
3597           // Don't convert CmpP null check into CmpN if compressed
3598           // oops implicit null check is not generated.
3599           // This will allow to generate normal oop implicit null check.
3600           if (Matcher::gen_narrow_oop_implicit_null_checks())
3601             new_in2 = ConNode::make(TypeNarrowOop::NULL_PTR);
3602           //
3603           // This transformation together with CastPP transformation above
3604           // will generated code for implicit null checks for compressed oops.
3605           //
3606           // The original code after Optimize()
3607           //
3608           //    LoadN memory, narrow_oop_reg
3609           //    decode narrow_oop_reg, base_reg
3610           //    CmpP base_reg, nullptr
3611           //    CastPP base_reg // NotNull
3612           //    Load [base_reg + offset], val_reg
3613           //
3614           // after these transformations will be
3615           //
3616           //    LoadN memory, narrow_oop_reg
3617           //    CmpN narrow_oop_reg, nullptr
3618           //    decode_not_null narrow_oop_reg, base_reg
3619           //    Load [base_reg + offset], val_reg
3620           //
3621           // and the uncommon path (== nullptr) will use narrow_oop_reg directly
3622           // since narrow oops can be used in debug info now (see the code in
3623           // final_graph_reshaping_walk()).
3624           //
3625           // At the end the code will be matched to
3626           // on x86:
3627           //
3628           //    Load_narrow_oop memory, narrow_oop_reg
3629           //    Load [R12 + narrow_oop_reg<<3 + offset], val_reg
3630           //    NullCheck narrow_oop_reg
3631           //
3632           // and on sparc:
3633           //
3634           //    Load_narrow_oop memory, narrow_oop_reg
3635           //    decode_not_null narrow_oop_reg, base_reg
3636           //    Load [base_reg + offset], val_reg
3637           //    NullCheck base_reg
3638           //
3639         } else if (t->isa_oopptr()) {
3640           new_in2 = ConNode::make(t->make_narrowoop());
3641         } else if (t->isa_klassptr()) {
3642           ciKlass* klass = t->is_klassptr()->exact_klass();
3643           if (klass->is_in_encoding_range()) {
3644             new_in2 = ConNode::make(t->make_narrowklass());
3645           }
3646         }
3647       }
3648       if (new_in2 != nullptr) {
3649         Node* cmpN = new CmpNNode(in1->in(1), new_in2);
3650         n->subsume_by(cmpN, this);
3651         if (in1->outcnt() == 0) {
3652           in1->disconnect_inputs(this);
3653         }
3654         if (in2->outcnt() == 0) {
3655           in2->disconnect_inputs(this);
3656         }
3657       }
3658     }
3659     break;
3660 
3661   case Op_DecodeN:
3662   case Op_DecodeNKlass:
3663     assert(!n->in(1)->is_EncodeNarrowPtr(), "should be optimized out");
3664     // DecodeN could be pinned when it can't be fold into
3665     // an address expression, see the code for Op_CastPP above.
3666     assert(n->in(0) == nullptr || (UseCompressedOops && !Matcher::narrow_oop_use_complex_address()), "no control");
3667     break;
3668 
3669   case Op_EncodeP:
3670   case Op_EncodePKlass: {
3671     Node* in1 = n->in(1);
3672     if (in1->is_DecodeNarrowPtr()) {
3673       n->subsume_by(in1->in(1), this);
3674     } else if (in1->Opcode() == Op_ConP) {
3675       const Type* t = in1->bottom_type();
3676       if (t == TypePtr::NULL_PTR) {
3677         assert(t->isa_oopptr(), "null klass?");
3678         n->subsume_by(ConNode::make(TypeNarrowOop::NULL_PTR), this);
3679       } else if (t->isa_oopptr()) {
3680         n->subsume_by(ConNode::make(t->make_narrowoop()), this);
3681       } else if (t->isa_klassptr()) {
3682         ciKlass* klass = t->is_klassptr()->exact_klass();
3683         if (klass->is_in_encoding_range()) {
3684           n->subsume_by(ConNode::make(t->make_narrowklass()), this);
3685         } else {
3686           assert(false, "unencodable klass in ConP -> EncodeP");
3687           C->record_failure("unencodable klass in ConP -> EncodeP");
3688         }
3689       }
3690     }
3691     if (in1->outcnt() == 0) {
3692       in1->disconnect_inputs(this);
3693     }
3694     break;
3695   }
3696 
3697   case Op_Proj: {
3698     if (OptimizeStringConcat || IncrementalInline) {
3699       ProjNode* proj = n->as_Proj();
3700       if (proj->_is_io_use) {
3701         assert(proj->_con == TypeFunc::I_O || proj->_con == TypeFunc::Memory, "");
3702         // Separate projections were used for the exception path which
3703         // are normally removed by a late inline.  If it wasn't inlined
3704         // then they will hang around and should just be replaced with
3705         // the original one. Merge them.
3706         Node* non_io_proj = proj->in(0)->as_Multi()->proj_out_or_null(proj->_con, false /*is_io_use*/);
3707         if (non_io_proj  != nullptr) {
3708           proj->subsume_by(non_io_proj , this);
3709         }
3710       }
3711     }
3712     break;
3713   }
3714 
3715   case Op_Phi:
3716     if (n->as_Phi()->bottom_type()->isa_narrowoop() || n->as_Phi()->bottom_type()->isa_narrowklass()) {
3717       // The EncodeP optimization may create Phi with the same edges
3718       // for all paths. It is not handled well by Register Allocator.
3719       Node* unique_in = n->in(1);
3720       assert(unique_in != nullptr, "");
3721       uint cnt = n->req();
3722       for (uint i = 2; i < cnt; i++) {
3723         Node* m = n->in(i);
3724         assert(m != nullptr, "");
3725         if (unique_in != m)
3726           unique_in = nullptr;
3727       }
3728       if (unique_in != nullptr) {
3729         n->subsume_by(unique_in, this);
3730       }
3731     }
3732     break;
3733 
3734 #endif
3735 
3736   case Op_ModI:
3737     handle_div_mod_op(n, T_INT, false);
3738     break;
3739 
3740   case Op_ModL:
3741     handle_div_mod_op(n, T_LONG, false);
3742     break;
3743 
3744   case Op_UModI:
3745     handle_div_mod_op(n, T_INT, true);
3746     break;
3747 
3748   case Op_UModL:
3749     handle_div_mod_op(n, T_LONG, true);
3750     break;
3751 
3752   case Op_LoadVector:
3753   case Op_StoreVector:
3754 #ifdef ASSERT
3755     // Add VerifyVectorAlignment node between adr and load / store.
3756     if (VerifyAlignVector && Matcher::has_match_rule(Op_VerifyVectorAlignment)) {
3757       bool must_verify_alignment = n->is_LoadVector() ? n->as_LoadVector()->must_verify_alignment() :
3758                                                         n->as_StoreVector()->must_verify_alignment();
3759       if (must_verify_alignment) {
3760         jlong vector_width = n->is_LoadVector() ? n->as_LoadVector()->memory_size() :
3761                                                   n->as_StoreVector()->memory_size();
3762         // The memory access should be aligned to the vector width in bytes.
3763         // However, the underlying array is possibly less well aligned, but at least
3764         // to ObjectAlignmentInBytes. Hence, even if multiple arrays are accessed in
3765         // a loop we can expect at least the following alignment:
3766         jlong guaranteed_alignment = MIN2(vector_width, (jlong)ObjectAlignmentInBytes);
3767         assert(2 <= guaranteed_alignment && guaranteed_alignment <= 64, "alignment must be in range");
3768         assert(is_power_of_2(guaranteed_alignment), "alignment must be power of 2");
3769         // Create mask from alignment. e.g. 0b1000 -> 0b0111
3770         jlong mask = guaranteed_alignment - 1;
3771         Node* mask_con = ConLNode::make(mask);
3772         VerifyVectorAlignmentNode* va = new VerifyVectorAlignmentNode(n->in(MemNode::Address), mask_con);
3773         n->set_req(MemNode::Address, va);
3774       }
3775     }
3776 #endif
3777     break;
3778 
3779   case Op_LoadVectorGather:
3780   case Op_StoreVectorScatter:
3781   case Op_LoadVectorGatherMasked:
3782   case Op_StoreVectorScatterMasked:
3783   case Op_VectorCmpMasked:
3784   case Op_VectorMaskGen:
3785   case Op_LoadVectorMasked:
3786   case Op_StoreVectorMasked:
3787     break;
3788 
3789   case Op_AddReductionVI:
3790   case Op_AddReductionVL:
3791   case Op_AddReductionVF:
3792   case Op_AddReductionVD:
3793   case Op_MulReductionVI:
3794   case Op_MulReductionVL:
3795   case Op_MulReductionVF:
3796   case Op_MulReductionVD:
3797   case Op_MinReductionV:
3798   case Op_MaxReductionV:
3799   case Op_AndReductionV:
3800   case Op_OrReductionV:
3801   case Op_XorReductionV:
3802     break;
3803 
3804   case Op_PackB:
3805   case Op_PackS:
3806   case Op_PackI:
3807   case Op_PackF:
3808   case Op_PackL:
3809   case Op_PackD:
3810     if (n->req()-1 > 2) {
3811       // Replace many operand PackNodes with a binary tree for matching
3812       PackNode* p = (PackNode*) n;
3813       Node* btp = p->binary_tree_pack(1, n->req());
3814       n->subsume_by(btp, this);
3815     }
3816     break;
3817   case Op_Loop:
3818     assert(!n->as_Loop()->is_loop_nest_inner_loop() || _loop_opts_cnt == 0, "should have been turned into a counted loop");
3819   case Op_CountedLoop:
3820   case Op_LongCountedLoop:
3821   case Op_OuterStripMinedLoop:
3822     if (n->as_Loop()->is_inner_loop()) {
3823       frc.inc_inner_loop_count();
3824     }
3825     n->as_Loop()->verify_strip_mined(0);
3826     break;
3827   case Op_LShiftI:
3828   case Op_RShiftI:
3829   case Op_URShiftI:
3830   case Op_LShiftL:
3831   case Op_RShiftL:
3832   case Op_URShiftL:
3833     if (Matcher::need_masked_shift_count) {
3834       // The cpu's shift instructions don't restrict the count to the
3835       // lower 5/6 bits. We need to do the masking ourselves.
3836       Node* in2 = n->in(2);
3837       juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
3838       const TypeInt* t = in2->find_int_type();
3839       if (t != nullptr && t->is_con()) {
3840         juint shift = t->get_con();
3841         if (shift > mask) { // Unsigned cmp
3842           n->set_req(2, ConNode::make(TypeInt::make(shift & mask)));
3843         }
3844       } else {
3845         if (t == nullptr || t->_lo < 0 || t->_hi > (int)mask) {
3846           Node* shift = new AndINode(in2, ConNode::make(TypeInt::make(mask)));
3847           n->set_req(2, shift);
3848         }
3849       }
3850       if (in2->outcnt() == 0) { // Remove dead node
3851         in2->disconnect_inputs(this);
3852       }
3853     }
3854     break;
3855   case Op_MemBarStoreStore:
3856   case Op_MemBarRelease:
3857     // Break the link with AllocateNode: it is no longer useful and
3858     // confuses register allocation.
3859     if (n->req() > MemBarNode::Precedent) {
3860       n->set_req(MemBarNode::Precedent, top());
3861     }
3862     break;
3863   case Op_MemBarAcquire: {
3864     if (n->as_MemBar()->trailing_load() && n->req() > MemBarNode::Precedent) {
3865       // At parse time, the trailing MemBarAcquire for a volatile load
3866       // is created with an edge to the load. After optimizations,
3867       // that input may be a chain of Phis. If those phis have no
3868       // other use, then the MemBarAcquire keeps them alive and
3869       // register allocation can be confused.
3870       dead_nodes.push(n->in(MemBarNode::Precedent));
3871       n->set_req(MemBarNode::Precedent, top());
3872     }
3873     break;
3874   }
3875   case Op_Blackhole:
3876     break;
3877   case Op_RangeCheck: {
3878     RangeCheckNode* rc = n->as_RangeCheck();
3879     Node* iff = new IfNode(rc->in(0), rc->in(1), rc->_prob, rc->_fcnt);
3880     n->subsume_by(iff, this);
3881     frc._tests.push(iff);
3882     break;
3883   }
3884   case Op_ConvI2L: {
3885     if (!Matcher::convi2l_type_required) {
3886       // Code generation on some platforms doesn't need accurate
3887       // ConvI2L types. Widening the type can help remove redundant
3888       // address computations.
3889       n->as_Type()->set_type(TypeLong::INT);
3890       ResourceMark rm;
3891       Unique_Node_List wq;
3892       wq.push(n);
3893       for (uint next = 0; next < wq.size(); next++) {
3894         Node *m = wq.at(next);
3895 
3896         for(;;) {
3897           // Loop over all nodes with identical inputs edges as m
3898           Node* k = m->find_similar(m->Opcode());
3899           if (k == nullptr) {
3900             break;
3901           }
3902           // Push their uses so we get a chance to remove node made
3903           // redundant
3904           for (DUIterator_Fast imax, i = k->fast_outs(imax); i < imax; i++) {
3905             Node* u = k->fast_out(i);
3906             if (u->Opcode() == Op_LShiftL ||
3907                 u->Opcode() == Op_AddL ||
3908                 u->Opcode() == Op_SubL ||
3909                 u->Opcode() == Op_AddP) {
3910               wq.push(u);
3911             }
3912           }
3913           // Replace all nodes with identical edges as m with m
3914           k->subsume_by(m, this);
3915         }
3916       }
3917     }
3918     break;
3919   }
3920   case Op_CmpUL: {
3921     if (!Matcher::has_match_rule(Op_CmpUL)) {
3922       // No support for unsigned long comparisons
3923       ConINode* sign_pos = new ConINode(TypeInt::make(BitsPerLong - 1));
3924       Node* sign_bit_mask = new RShiftLNode(n->in(1), sign_pos);
3925       Node* orl = new OrLNode(n->in(1), sign_bit_mask);
3926       ConLNode* remove_sign_mask = new ConLNode(TypeLong::make(max_jlong));
3927       Node* andl = new AndLNode(orl, remove_sign_mask);
3928       Node* cmp = new CmpLNode(andl, n->in(2));
3929       n->subsume_by(cmp, this);
3930     }
3931     break;
3932   }
3933 #ifdef ASSERT
3934   case Op_ConNKlass: {
3935     const TypePtr* tp = n->as_Type()->type()->make_ptr();
3936     ciKlass* klass = tp->is_klassptr()->exact_klass();
3937     assert(klass->is_in_encoding_range(), "klass cannot be compressed");
3938     break;
3939   }
3940 #endif
3941   default:
3942     assert(!n->is_Call(), "");
3943     assert(!n->is_Mem(), "");
3944     assert(nop != Op_ProfileBoolean, "should be eliminated during IGVN");
3945     break;
3946   }
3947 }
3948 
3949 //------------------------------final_graph_reshaping_walk---------------------
3950 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
3951 // requires that the walk visits a node's inputs before visiting the node.
3952 void Compile::final_graph_reshaping_walk(Node_Stack& nstack, Node* root, Final_Reshape_Counts& frc, Unique_Node_List& dead_nodes) {
3953   Unique_Node_List sfpt;
3954 
3955   frc._visited.set(root->_idx); // first, mark node as visited
3956   uint cnt = root->req();
3957   Node *n = root;
3958   uint  i = 0;
3959   while (true) {
3960     if (i < cnt) {
3961       // Place all non-visited non-null inputs onto stack
3962       Node* m = n->in(i);
3963       ++i;
3964       if (m != nullptr && !frc._visited.test_set(m->_idx)) {
3965         if (m->is_SafePoint() && m->as_SafePoint()->jvms() != nullptr) {
3966           // compute worst case interpreter size in case of a deoptimization
3967           update_interpreter_frame_size(m->as_SafePoint()->jvms()->interpreter_frame_size());
3968 
3969           sfpt.push(m);
3970         }
3971         cnt = m->req();
3972         nstack.push(n, i); // put on stack parent and next input's index
3973         n = m;
3974         i = 0;
3975       }
3976     } else {
3977       // Now do post-visit work
3978       final_graph_reshaping_impl(n, frc, dead_nodes);
3979       if (nstack.is_empty())
3980         break;             // finished
3981       n = nstack.node();   // Get node from stack
3982       cnt = n->req();
3983       i = nstack.index();
3984       nstack.pop();        // Shift to the next node on stack
3985     }
3986   }
3987 
3988   // Skip next transformation if compressed oops are not used.
3989   if ((UseCompressedOops && !Matcher::gen_narrow_oop_implicit_null_checks()) ||
3990       (!UseCompressedOops && !UseCompressedClassPointers))
3991     return;
3992 
3993   // Go over safepoints nodes to skip DecodeN/DecodeNKlass nodes for debug edges.
3994   // It could be done for an uncommon traps or any safepoints/calls
3995   // if the DecodeN/DecodeNKlass node is referenced only in a debug info.
3996   while (sfpt.size() > 0) {
3997     n = sfpt.pop();
3998     JVMState *jvms = n->as_SafePoint()->jvms();
3999     assert(jvms != nullptr, "sanity");
4000     int start = jvms->debug_start();
4001     int end   = n->req();
4002     bool is_uncommon = (n->is_CallStaticJava() &&
4003                         n->as_CallStaticJava()->uncommon_trap_request() != 0);
4004     for (int j = start; j < end; j++) {
4005       Node* in = n->in(j);
4006       if (in->is_DecodeNarrowPtr()) {
4007         bool safe_to_skip = true;
4008         if (!is_uncommon ) {
4009           // Is it safe to skip?
4010           for (uint i = 0; i < in->outcnt(); i++) {
4011             Node* u = in->raw_out(i);
4012             if (!u->is_SafePoint() ||
4013                 (u->is_Call() && u->as_Call()->has_non_debug_use(n))) {
4014               safe_to_skip = false;
4015             }
4016           }
4017         }
4018         if (safe_to_skip) {
4019           n->set_req(j, in->in(1));
4020         }
4021         if (in->outcnt() == 0) {
4022           in->disconnect_inputs(this);
4023         }
4024       }
4025     }
4026   }
4027 }
4028 
4029 //------------------------------final_graph_reshaping--------------------------
4030 // Final Graph Reshaping.
4031 //
4032 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
4033 //     and not commoned up and forced early.  Must come after regular
4034 //     optimizations to avoid GVN undoing the cloning.  Clone constant
4035 //     inputs to Loop Phis; these will be split by the allocator anyways.
4036 //     Remove Opaque nodes.
4037 // (2) Move last-uses by commutative operations to the left input to encourage
4038 //     Intel update-in-place two-address operations and better register usage
4039 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
4040 //     calls canonicalizing them back.
4041 // (3) Count the number of double-precision FP ops, single-precision FP ops
4042 //     and call sites.  On Intel, we can get correct rounding either by
4043 //     forcing singles to memory (requires extra stores and loads after each
4044 //     FP bytecode) or we can set a rounding mode bit (requires setting and
4045 //     clearing the mode bit around call sites).  The mode bit is only used
4046 //     if the relative frequency of single FP ops to calls is low enough.
4047 //     This is a key transform for SPEC mpeg_audio.
4048 // (4) Detect infinite loops; blobs of code reachable from above but not
4049 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
4050 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
4051 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
4052 //     Detection is by looking for IfNodes where only 1 projection is
4053 //     reachable from below or CatchNodes missing some targets.
4054 // (5) Assert for insane oop offsets in debug mode.
4055 
4056 bool Compile::final_graph_reshaping() {
4057   // an infinite loop may have been eliminated by the optimizer,
4058   // in which case the graph will be empty.
4059   if (root()->req() == 1) {
4060     // Do not compile method that is only a trivial infinite loop,
4061     // since the content of the loop may have been eliminated.
4062     record_method_not_compilable("trivial infinite loop");
4063     return true;
4064   }
4065 
4066   // Expensive nodes have their control input set to prevent the GVN
4067   // from freely commoning them. There's no GVN beyond this point so
4068   // no need to keep the control input. We want the expensive nodes to
4069   // be freely moved to the least frequent code path by gcm.
4070   assert(OptimizeExpensiveOps || expensive_count() == 0, "optimization off but list non empty?");
4071   for (int i = 0; i < expensive_count(); i++) {
4072     _expensive_nodes.at(i)->set_req(0, nullptr);
4073   }
4074 
4075   Final_Reshape_Counts frc;
4076 
4077   // Visit everybody reachable!
4078   // Allocate stack of size C->live_nodes()/2 to avoid frequent realloc
4079   Node_Stack nstack(live_nodes() >> 1);
4080   Unique_Node_List dead_nodes;
4081   final_graph_reshaping_walk(nstack, root(), frc, dead_nodes);
4082 
4083   // Check for unreachable (from below) code (i.e., infinite loops).
4084   for( uint i = 0; i < frc._tests.size(); i++ ) {
4085     MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
4086     // Get number of CFG targets.
4087     // Note that PCTables include exception targets after calls.
4088     uint required_outcnt = n->required_outcnt();
4089     if (n->outcnt() != required_outcnt) {
4090       // Check for a few special cases.  Rethrow Nodes never take the
4091       // 'fall-thru' path, so expected kids is 1 less.
4092       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
4093         if (n->in(0)->in(0)->is_Call()) {
4094           CallNode* call = n->in(0)->in(0)->as_Call();
4095           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
4096             required_outcnt--;      // Rethrow always has 1 less kid
4097           } else if (call->req() > TypeFunc::Parms &&
4098                      call->is_CallDynamicJava()) {
4099             // Check for null receiver. In such case, the optimizer has
4100             // detected that the virtual call will always result in a null
4101             // pointer exception. The fall-through projection of this CatchNode
4102             // will not be populated.
4103             Node* arg0 = call->in(TypeFunc::Parms);
4104             if (arg0->is_Type() &&
4105                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
4106               required_outcnt--;
4107             }
4108           } else if (call->entry_point() == OptoRuntime::new_array_Java() ||
4109                      call->entry_point() == OptoRuntime::new_array_nozero_Java()) {
4110             // Check for illegal array length. In such case, the optimizer has
4111             // detected that the allocation attempt will always result in an
4112             // exception. There is no fall-through projection of this CatchNode .
4113             assert(call->is_CallStaticJava(), "static call expected");
4114             assert(call->req() == call->jvms()->endoff() + 1, "missing extra input");
4115             uint valid_length_test_input = call->req() - 1;
4116             Node* valid_length_test = call->in(valid_length_test_input);
4117             call->del_req(valid_length_test_input);
4118             if (valid_length_test->find_int_con(1) == 0) {
4119               required_outcnt--;
4120             }
4121             dead_nodes.push(valid_length_test);
4122             assert(n->outcnt() == required_outcnt, "malformed control flow");
4123             continue;
4124           }
4125         }
4126       }
4127 
4128       // Recheck with a better notion of 'required_outcnt'
4129       if (n->outcnt() != required_outcnt) {
4130         record_method_not_compilable("malformed control flow");
4131         return true;            // Not all targets reachable!
4132       }
4133     } else if (n->is_PCTable() && n->in(0) && n->in(0)->in(0) && n->in(0)->in(0)->is_Call()) {
4134       CallNode* call = n->in(0)->in(0)->as_Call();
4135       if (call->entry_point() == OptoRuntime::new_array_Java() ||
4136           call->entry_point() == OptoRuntime::new_array_nozero_Java()) {
4137         assert(call->is_CallStaticJava(), "static call expected");
4138         assert(call->req() == call->jvms()->endoff() + 1, "missing extra input");
4139         uint valid_length_test_input = call->req() - 1;
4140         dead_nodes.push(call->in(valid_length_test_input));
4141         call->del_req(valid_length_test_input); // valid length test useless now
4142       }
4143     }
4144     // Check that I actually visited all kids.  Unreached kids
4145     // must be infinite loops.
4146     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
4147       if (!frc._visited.test(n->fast_out(j)->_idx)) {
4148         record_method_not_compilable("infinite loop");
4149         return true;            // Found unvisited kid; must be unreach
4150       }
4151 
4152     // Here so verification code in final_graph_reshaping_walk()
4153     // always see an OuterStripMinedLoopEnd
4154     if (n->is_OuterStripMinedLoopEnd() || n->is_LongCountedLoopEnd()) {
4155       IfNode* init_iff = n->as_If();
4156       Node* iff = new IfNode(init_iff->in(0), init_iff->in(1), init_iff->_prob, init_iff->_fcnt);
4157       n->subsume_by(iff, this);
4158     }
4159   }
4160 
4161   while (dead_nodes.size() > 0) {
4162     Node* m = dead_nodes.pop();
4163     if (m->outcnt() == 0 && m != top()) {
4164       for (uint j = 0; j < m->req(); j++) {
4165         Node* in = m->in(j);
4166         if (in != nullptr) {
4167           dead_nodes.push(in);
4168         }
4169       }
4170       m->disconnect_inputs(this);
4171     }
4172   }
4173 
4174   set_java_calls(frc.get_java_call_count());
4175   set_inner_loops(frc.get_inner_loop_count());
4176 
4177   // No infinite loops, no reason to bail out.
4178   return false;
4179 }
4180 
4181 //-----------------------------too_many_traps----------------------------------
4182 // Report if there are too many traps at the current method and bci.
4183 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
4184 bool Compile::too_many_traps(ciMethod* method,
4185                              int bci,
4186                              Deoptimization::DeoptReason reason) {
4187   if (method->has_trap_at(bci)) {
4188     return true;
4189   }
4190   if (PreloadReduceTraps && for_preload()) {
4191     // Preload code should not have traps, if possible.
4192     return true;
4193   }
4194   ciMethodData* md = method->method_data();
4195   if (md->is_empty()) {
4196     // Assume the trap has not occurred, or that it occurred only
4197     // because of a transient condition during start-up in the interpreter.
4198     return false;
4199   }
4200   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : nullptr;
4201   if (md->has_trap_at(bci, m, reason) != 0) {
4202     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
4203     // Also, if there are multiple reasons, or if there is no per-BCI record,
4204     // assume the worst.
4205     if (log())
4206       log()->elem("observe trap='%s' count='%d'",
4207                   Deoptimization::trap_reason_name(reason),
4208                   md->trap_count(reason));
4209     return true;
4210   } else {
4211     // Ignore method/bci and see if there have been too many globally.
4212     return too_many_traps(reason, md);
4213   }
4214 }
4215 
4216 // Less-accurate variant which does not require a method and bci.
4217 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
4218                              ciMethodData* logmd) {
4219   if (PreloadReduceTraps && for_preload()) {
4220     // Preload code should not have traps, if possible.
4221     return true;
4222   }
4223   if (trap_count(reason) >= Deoptimization::per_method_trap_limit(reason)) {
4224     // Too many traps globally.
4225     // Note that we use cumulative trap_count, not just md->trap_count.
4226     if (log()) {
4227       int mcount = (logmd == nullptr)? -1: (int)logmd->trap_count(reason);
4228       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
4229                   Deoptimization::trap_reason_name(reason),
4230                   mcount, trap_count(reason));
4231     }
4232     return true;
4233   } else {
4234     // The coast is clear.
4235     return false;
4236   }
4237 }
4238 
4239 //--------------------------too_many_recompiles--------------------------------
4240 // Report if there are too many recompiles at the current method and bci.
4241 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
4242 // Is not eager to return true, since this will cause the compiler to use
4243 // Action_none for a trap point, to avoid too many recompilations.
4244 bool Compile::too_many_recompiles(ciMethod* method,
4245                                   int bci,
4246                                   Deoptimization::DeoptReason reason) {
4247   ciMethodData* md = method->method_data();
4248   if (md->is_empty()) {
4249     // Assume the trap has not occurred, or that it occurred only
4250     // because of a transient condition during start-up in the interpreter.
4251     return false;
4252   }
4253   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
4254   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
4255   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
4256   Deoptimization::DeoptReason per_bc_reason
4257     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
4258   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : nullptr;
4259   if ((per_bc_reason == Deoptimization::Reason_none
4260        || md->has_trap_at(bci, m, reason) != 0)
4261       // The trap frequency measure we care about is the recompile count:
4262       && md->trap_recompiled_at(bci, m)
4263       && md->overflow_recompile_count() >= bc_cutoff) {
4264     // Do not emit a trap here if it has already caused recompilations.
4265     // Also, if there are multiple reasons, or if there is no per-BCI record,
4266     // assume the worst.
4267     if (log())
4268       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
4269                   Deoptimization::trap_reason_name(reason),
4270                   md->trap_count(reason),
4271                   md->overflow_recompile_count());
4272     return true;
4273   } else if (trap_count(reason) != 0
4274              && decompile_count() >= m_cutoff) {
4275     // Too many recompiles globally, and we have seen this sort of trap.
4276     // Use cumulative decompile_count, not just md->decompile_count.
4277     if (log())
4278       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
4279                   Deoptimization::trap_reason_name(reason),
4280                   md->trap_count(reason), trap_count(reason),
4281                   md->decompile_count(), decompile_count());
4282     return true;
4283   } else {
4284     // The coast is clear.
4285     return false;
4286   }
4287 }
4288 
4289 // Compute when not to trap. Used by matching trap based nodes and
4290 // NullCheck optimization.
4291 void Compile::set_allowed_deopt_reasons() {
4292   _allowed_reasons = 0;
4293   if (is_method_compilation()) {
4294     for (int rs = (int)Deoptimization::Reason_none+1; rs < Compile::trapHistLength; rs++) {
4295       assert(rs < BitsPerInt, "recode bit map");
4296       if (!too_many_traps((Deoptimization::DeoptReason) rs)) {
4297         _allowed_reasons |= nth_bit(rs);
4298       }
4299     }
4300   }
4301 }
4302 
4303 bool Compile::needs_clinit_barrier(ciMethod* method, ciMethod* accessing_method) {
4304   return method->is_static() && needs_clinit_barrier(method->holder(), accessing_method);
4305 }
4306 
4307 bool Compile::needs_clinit_barrier(ciField* field, ciMethod* accessing_method) {
4308   return field->is_static() && needs_clinit_barrier(field->holder(), accessing_method);
4309 }
4310 
4311 bool Compile::needs_clinit_barrier(ciInstanceKlass* holder, ciMethod* accessing_method) {
4312   if (holder->is_initialized() && !do_clinit_barriers()) {
4313     return false;
4314   }
4315   if (holder->is_being_initialized() || do_clinit_barriers()) {
4316     if (accessing_method->holder() == holder) {
4317       // Access inside a class. The barrier can be elided when access happens in <clinit>,
4318       // <init>, or a static method. In all those cases, there was an initialization
4319       // barrier on the holder klass passed.
4320       if (accessing_method->is_static_initializer() ||
4321           accessing_method->is_object_initializer() ||
4322           accessing_method->is_static()) {
4323         return false;
4324       }
4325     } else if (accessing_method->holder()->is_subclass_of(holder)) {
4326       // Access from a subclass. The barrier can be elided only when access happens in <clinit>.
4327       // In case of <init> or a static method, the barrier is on the subclass is not enough:
4328       // child class can become fully initialized while its parent class is still being initialized.
4329       if (accessing_method->is_static_initializer()) {
4330         return false;
4331       }
4332     }
4333     ciMethod* root = method(); // the root method of compilation
4334     if (root != accessing_method) {
4335       return needs_clinit_barrier(holder, root); // check access in the context of compilation root
4336     }
4337   }
4338   return true;
4339 }
4340 
4341 #ifndef PRODUCT
4342 //------------------------------verify_bidirectional_edges---------------------
4343 // For each input edge to a node (ie - for each Use-Def edge), verify that
4344 // there is a corresponding Def-Use edge.
4345 void Compile::verify_bidirectional_edges(Unique_Node_List& visited, const Unique_Node_List* root_and_safepoints) const {
4346   // Allocate stack of size C->live_nodes()/16 to avoid frequent realloc
4347   uint stack_size = live_nodes() >> 4;
4348   Node_List nstack(MAX2(stack_size, (uint) OptoNodeListSize));
4349   if (root_and_safepoints != nullptr) {
4350     assert(root_and_safepoints->member(_root), "root is not in root_and_safepoints");
4351     for (uint i = 0, limit = root_and_safepoints->size(); i < limit; i++) {
4352       Node* root_or_safepoint = root_and_safepoints->at(i);
4353       // If the node is a safepoint, let's check if it still has a control input
4354       // Lack of control input signifies that this node was killed by CCP or
4355       // recursively by remove_globally_dead_node and it shouldn't be a starting
4356       // point.
4357       if (!root_or_safepoint->is_SafePoint() || root_or_safepoint->in(0) != nullptr) {
4358         nstack.push(root_or_safepoint);
4359       }
4360     }
4361   } else {
4362     nstack.push(_root);
4363   }
4364 
4365   while (nstack.size() > 0) {
4366     Node* n = nstack.pop();
4367     if (visited.member(n)) {
4368       continue;
4369     }
4370     visited.push(n);
4371 
4372     // Walk over all input edges, checking for correspondence
4373     uint length = n->len();
4374     for (uint i = 0; i < length; i++) {
4375       Node* in = n->in(i);
4376       if (in != nullptr && !visited.member(in)) {
4377         nstack.push(in); // Put it on stack
4378       }
4379       if (in != nullptr && !in->is_top()) {
4380         // Count instances of `next`
4381         int cnt = 0;
4382         for (uint idx = 0; idx < in->_outcnt; idx++) {
4383           if (in->_out[idx] == n) {
4384             cnt++;
4385           }
4386         }
4387         assert(cnt > 0, "Failed to find Def-Use edge.");
4388         // Check for duplicate edges
4389         // walk the input array downcounting the input edges to n
4390         for (uint j = 0; j < length; j++) {
4391           if (n->in(j) == in) {
4392             cnt--;
4393           }
4394         }
4395         assert(cnt == 0, "Mismatched edge count.");
4396       } else if (in == nullptr) {
4397         assert(i == 0 || i >= n->req() ||
4398                n->is_Region() || n->is_Phi() || n->is_ArrayCopy() ||
4399                (n->is_Unlock() && i == (n->req() - 1)) ||
4400                (n->is_MemBar() && i == 5), // the precedence edge to a membar can be removed during macro node expansion
4401               "only region, phi, arraycopy, unlock or membar nodes have null data edges");
4402       } else {
4403         assert(in->is_top(), "sanity");
4404         // Nothing to check.
4405       }
4406     }
4407   }
4408 }
4409 
4410 //------------------------------verify_graph_edges---------------------------
4411 // Walk the Graph and verify that there is a one-to-one correspondence
4412 // between Use-Def edges and Def-Use edges in the graph.
4413 void Compile::verify_graph_edges(bool no_dead_code, const Unique_Node_List* root_and_safepoints) const {
4414   if (VerifyGraphEdges) {
4415     Unique_Node_List visited;
4416 
4417     // Call graph walk to check edges
4418     verify_bidirectional_edges(visited, root_and_safepoints);
4419     if (no_dead_code) {
4420       // Now make sure that no visited node is used by an unvisited node.
4421       bool dead_nodes = false;
4422       Unique_Node_List checked;
4423       while (visited.size() > 0) {
4424         Node* n = visited.pop();
4425         checked.push(n);
4426         for (uint i = 0; i < n->outcnt(); i++) {
4427           Node* use = n->raw_out(i);
4428           if (checked.member(use))  continue;  // already checked
4429           if (visited.member(use))  continue;  // already in the graph
4430           if (use->is_Con())        continue;  // a dead ConNode is OK
4431           // At this point, we have found a dead node which is DU-reachable.
4432           if (!dead_nodes) {
4433             tty->print_cr("*** Dead nodes reachable via DU edges:");
4434             dead_nodes = true;
4435           }
4436           use->dump(2);
4437           tty->print_cr("---");
4438           checked.push(use);  // No repeats; pretend it is now checked.
4439         }
4440       }
4441       assert(!dead_nodes, "using nodes must be reachable from root");
4442     }
4443   }
4444 }
4445 #endif
4446 
4447 // The Compile object keeps track of failure reasons separately from the ciEnv.
4448 // This is required because there is not quite a 1-1 relation between the
4449 // ciEnv and its compilation task and the Compile object.  Note that one
4450 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
4451 // to backtrack and retry without subsuming loads.  Other than this backtracking
4452 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
4453 // by the logic in C2Compiler.
4454 void Compile::record_failure(const char* reason DEBUG_ONLY(COMMA bool allow_multiple_failures)) {
4455   if (log() != nullptr) {
4456     log()->elem("failure reason='%s' phase='compile'", reason);
4457   }
4458   if (_failure_reason.get() == nullptr) {
4459     // Record the first failure reason.
4460     _failure_reason.set(reason);
4461     if (CaptureBailoutInformation) {
4462       _first_failure_details = new CompilationFailureInfo(reason);
4463     }
4464   } else {
4465     assert(!StressBailout || allow_multiple_failures, "should have handled previous failure.");
4466   }
4467 
4468   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
4469     C->print_method(PHASE_FAILURE, 1);
4470   }
4471   _root = nullptr;  // flush the graph, too
4472 }
4473 
4474 Compile::TracePhase::TracePhase(const char* name, PhaseTraceId id)
4475   : TraceTime(name, &Phase::timers[id], CITime, CITimeVerbose),
4476     _compile(Compile::current()),
4477     _log(nullptr),
4478     _dolog(CITimeVerbose)
4479 {
4480   assert(_compile != nullptr, "sanity check");
4481   assert(id != PhaseTraceId::_t_none, "Don't use none");
4482   if (_dolog) {
4483     _log = _compile->log();
4484   }
4485   if (_log != nullptr) {
4486     _log->begin_head("phase name='%s' nodes='%d' live='%d'", phase_name(), _compile->unique(), _compile->live_nodes());
4487     _log->stamp();
4488     _log->end_head();
4489   }
4490 
4491   // Inform memory statistic, if enabled
4492   if (CompilationMemoryStatistic::enabled()) {
4493     CompilationMemoryStatistic::on_phase_start((int)id, name);
4494   }
4495 }
4496 
4497 Compile::TracePhase::TracePhase(PhaseTraceId id)
4498   : TracePhase(Phase::get_phase_trace_id_text(id), id) {}
4499 
4500 Compile::TracePhase::~TracePhase() {
4501 
4502   // Inform memory statistic, if enabled
4503   if (CompilationMemoryStatistic::enabled()) {
4504     CompilationMemoryStatistic::on_phase_end();
4505   }
4506 
4507   if (_compile->failing_internal()) {
4508     if (_log != nullptr) {
4509       _log->done("phase");
4510     }
4511     return; // timing code, not stressing bailouts.
4512   }
4513 #ifdef ASSERT
4514   if (PrintIdealNodeCount) {
4515     tty->print_cr("phase name='%s' nodes='%d' live='%d' live_graph_walk='%d'",
4516                   phase_name(), _compile->unique(), _compile->live_nodes(), _compile->count_live_nodes_by_graph_walk());
4517   }
4518 
4519   if (VerifyIdealNodeCount) {
4520     _compile->print_missing_nodes();
4521   }
4522 #endif
4523 
4524   if (_log != nullptr) {
4525     _log->done("phase name='%s' nodes='%d' live='%d'", phase_name(), _compile->unique(), _compile->live_nodes());
4526   }
4527 }
4528 
4529 //----------------------------static_subtype_check-----------------------------
4530 // Shortcut important common cases when superklass is exact:
4531 // (0) superklass is java.lang.Object (can occur in reflective code)
4532 // (1) subklass is already limited to a subtype of superklass => always ok
4533 // (2) subklass does not overlap with superklass => always fail
4534 // (3) superklass has NO subtypes and we can check with a simple compare.
4535 Compile::SubTypeCheckResult Compile::static_subtype_check(const TypeKlassPtr* superk, const TypeKlassPtr* subk, bool skip) {
4536   if (skip) {
4537     return SSC_full_test;       // Let caller generate the general case.
4538   }
4539 
4540   if (subk->is_java_subtype_of(superk)) {
4541     return SSC_always_true; // (0) and (1)  this test cannot fail
4542   }
4543 
4544   if (!subk->maybe_java_subtype_of(superk)) {
4545     return SSC_always_false; // (2) true path dead; no dynamic test needed
4546   }
4547 
4548   const Type* superelem = superk;
4549   if (superk->isa_aryklassptr()) {
4550     int ignored;
4551     superelem = superk->is_aryklassptr()->base_element_type(ignored);
4552   }
4553 
4554   if (superelem->isa_instklassptr()) {
4555     ciInstanceKlass* ik = superelem->is_instklassptr()->instance_klass();
4556     if (!ik->has_subklass()) {
4557       if (!ik->is_final()) {
4558         // Add a dependency if there is a chance of a later subclass.
4559         dependencies()->assert_leaf_type(ik);
4560       }
4561       if (!superk->maybe_java_subtype_of(subk)) {
4562         return SSC_always_false;
4563       }
4564       return SSC_easy_test;     // (3) caller can do a simple ptr comparison
4565     }
4566   } else {
4567     // A primitive array type has no subtypes.
4568     return SSC_easy_test;       // (3) caller can do a simple ptr comparison
4569   }
4570 
4571   return SSC_full_test;
4572 }
4573 
4574 Node* Compile::conv_I2X_index(PhaseGVN* phase, Node* idx, const TypeInt* sizetype, Node* ctrl) {
4575 #ifdef _LP64
4576   // The scaled index operand to AddP must be a clean 64-bit value.
4577   // Java allows a 32-bit int to be incremented to a negative
4578   // value, which appears in a 64-bit register as a large
4579   // positive number.  Using that large positive number as an
4580   // operand in pointer arithmetic has bad consequences.
4581   // On the other hand, 32-bit overflow is rare, and the possibility
4582   // can often be excluded, if we annotate the ConvI2L node with
4583   // a type assertion that its value is known to be a small positive
4584   // number.  (The prior range check has ensured this.)
4585   // This assertion is used by ConvI2LNode::Ideal.
4586   int index_max = max_jint - 1;  // array size is max_jint, index is one less
4587   if (sizetype != nullptr && sizetype->_hi > 0) {
4588     index_max = sizetype->_hi - 1;
4589   }
4590   const TypeInt* iidxtype = TypeInt::make(0, index_max, Type::WidenMax);
4591   idx = constrained_convI2L(phase, idx, iidxtype, ctrl);
4592 #endif
4593   return idx;
4594 }
4595 
4596 // Convert integer value to a narrowed long type dependent on ctrl (for example, a range check)
4597 Node* Compile::constrained_convI2L(PhaseGVN* phase, Node* value, const TypeInt* itype, Node* ctrl, bool carry_dependency) {
4598   if (ctrl != nullptr) {
4599     // Express control dependency by a CastII node with a narrow type.
4600     // Make the CastII node dependent on the control input to prevent the narrowed ConvI2L
4601     // node from floating above the range check during loop optimizations. Otherwise, the
4602     // ConvI2L node may be eliminated independently of the range check, causing the data path
4603     // to become TOP while the control path is still there (although it's unreachable).
4604     value = new CastIINode(ctrl, value, itype, carry_dependency ? ConstraintCastNode::StrongDependency : ConstraintCastNode::RegularDependency, true /* range check dependency */);
4605     value = phase->transform(value);
4606   }
4607   const TypeLong* ltype = TypeLong::make(itype->_lo, itype->_hi, itype->_widen);
4608   return phase->transform(new ConvI2LNode(value, ltype));
4609 }
4610 
4611 void Compile::dump_print_inlining() {
4612   inline_printer()->print_on(tty);
4613 }
4614 
4615 void Compile::log_late_inline(CallGenerator* cg) {
4616   if (log() != nullptr) {
4617     log()->head("late_inline method='%d' inline_id='" JLONG_FORMAT "'", log()->identify(cg->method()),
4618                 cg->unique_id());
4619     JVMState* p = cg->call_node()->jvms();
4620     while (p != nullptr) {
4621       log()->elem("jvms bci='%d' method='%d'", p->bci(), log()->identify(p->method()));
4622       p = p->caller();
4623     }
4624     log()->tail("late_inline");
4625   }
4626 }
4627 
4628 void Compile::log_late_inline_failure(CallGenerator* cg, const char* msg) {
4629   log_late_inline(cg);
4630   if (log() != nullptr) {
4631     log()->inline_fail(msg);
4632   }
4633 }
4634 
4635 void Compile::log_inline_id(CallGenerator* cg) {
4636   if (log() != nullptr) {
4637     // The LogCompilation tool needs a unique way to identify late
4638     // inline call sites. This id must be unique for this call site in
4639     // this compilation. Try to have it unique across compilations as
4640     // well because it can be convenient when grepping through the log
4641     // file.
4642     // Distinguish OSR compilations from others in case CICountOSR is
4643     // on.
4644     jlong id = ((jlong)unique()) + (((jlong)compile_id()) << 33) + (CICountOSR && is_osr_compilation() ? ((jlong)1) << 32 : 0);
4645     cg->set_unique_id(id);
4646     log()->elem("inline_id id='" JLONG_FORMAT "'", id);
4647   }
4648 }
4649 
4650 void Compile::log_inline_failure(const char* msg) {
4651   if (C->log() != nullptr) {
4652     C->log()->inline_fail(msg);
4653   }
4654 }
4655 
4656 
4657 // Dump inlining replay data to the stream.
4658 // Don't change thread state and acquire any locks.
4659 void Compile::dump_inline_data(outputStream* out) {
4660   InlineTree* inl_tree = ilt();
4661   if (inl_tree != nullptr) {
4662     out->print(" inline %d", inl_tree->count());
4663     inl_tree->dump_replay_data(out);
4664   }
4665 }
4666 
4667 void Compile::dump_inline_data_reduced(outputStream* out) {
4668   assert(ReplayReduce, "");
4669 
4670   InlineTree* inl_tree = ilt();
4671   if (inl_tree == nullptr) {
4672     return;
4673   }
4674   // Enable iterative replay file reduction
4675   // Output "compile" lines for depth 1 subtrees,
4676   // simulating that those trees were compiled
4677   // instead of inlined.
4678   for (int i = 0; i < inl_tree->subtrees().length(); ++i) {
4679     InlineTree* sub = inl_tree->subtrees().at(i);
4680     if (sub->inline_level() != 1) {
4681       continue;
4682     }
4683 
4684     ciMethod* method = sub->method();
4685     int entry_bci = -1;
4686     int comp_level = env()->task()->comp_level();
4687     out->print("compile ");
4688     method->dump_name_as_ascii(out);
4689     out->print(" %d %d", entry_bci, comp_level);
4690     out->print(" inline %d", sub->count());
4691     sub->dump_replay_data(out, -1);
4692     out->cr();
4693   }
4694 }
4695 
4696 int Compile::cmp_expensive_nodes(Node* n1, Node* n2) {
4697   if (n1->Opcode() < n2->Opcode())      return -1;
4698   else if (n1->Opcode() > n2->Opcode()) return 1;
4699 
4700   assert(n1->req() == n2->req(), "can't compare %s nodes: n1->req() = %d, n2->req() = %d", NodeClassNames[n1->Opcode()], n1->req(), n2->req());
4701   for (uint i = 1; i < n1->req(); i++) {
4702     if (n1->in(i) < n2->in(i))      return -1;
4703     else if (n1->in(i) > n2->in(i)) return 1;
4704   }
4705 
4706   return 0;
4707 }
4708 
4709 int Compile::cmp_expensive_nodes(Node** n1p, Node** n2p) {
4710   Node* n1 = *n1p;
4711   Node* n2 = *n2p;
4712 
4713   return cmp_expensive_nodes(n1, n2);
4714 }
4715 
4716 void Compile::sort_expensive_nodes() {
4717   if (!expensive_nodes_sorted()) {
4718     _expensive_nodes.sort(cmp_expensive_nodes);
4719   }
4720 }
4721 
4722 bool Compile::expensive_nodes_sorted() const {
4723   for (int i = 1; i < _expensive_nodes.length(); i++) {
4724     if (cmp_expensive_nodes(_expensive_nodes.adr_at(i), _expensive_nodes.adr_at(i-1)) < 0) {
4725       return false;
4726     }
4727   }
4728   return true;
4729 }
4730 
4731 bool Compile::should_optimize_expensive_nodes(PhaseIterGVN &igvn) {
4732   if (_expensive_nodes.length() == 0) {
4733     return false;
4734   }
4735 
4736   assert(OptimizeExpensiveOps, "optimization off?");
4737 
4738   // Take this opportunity to remove dead nodes from the list
4739   int j = 0;
4740   for (int i = 0; i < _expensive_nodes.length(); i++) {
4741     Node* n = _expensive_nodes.at(i);
4742     if (!n->is_unreachable(igvn)) {
4743       assert(n->is_expensive(), "should be expensive");
4744       _expensive_nodes.at_put(j, n);
4745       j++;
4746     }
4747   }
4748   _expensive_nodes.trunc_to(j);
4749 
4750   // Then sort the list so that similar nodes are next to each other
4751   // and check for at least two nodes of identical kind with same data
4752   // inputs.
4753   sort_expensive_nodes();
4754 
4755   for (int i = 0; i < _expensive_nodes.length()-1; i++) {
4756     if (cmp_expensive_nodes(_expensive_nodes.adr_at(i), _expensive_nodes.adr_at(i+1)) == 0) {
4757       return true;
4758     }
4759   }
4760 
4761   return false;
4762 }
4763 
4764 void Compile::cleanup_expensive_nodes(PhaseIterGVN &igvn) {
4765   if (_expensive_nodes.length() == 0) {
4766     return;
4767   }
4768 
4769   assert(OptimizeExpensiveOps, "optimization off?");
4770 
4771   // Sort to bring similar nodes next to each other and clear the
4772   // control input of nodes for which there's only a single copy.
4773   sort_expensive_nodes();
4774 
4775   int j = 0;
4776   int identical = 0;
4777   int i = 0;
4778   bool modified = false;
4779   for (; i < _expensive_nodes.length()-1; i++) {
4780     assert(j <= i, "can't write beyond current index");
4781     if (_expensive_nodes.at(i)->Opcode() == _expensive_nodes.at(i+1)->Opcode()) {
4782       identical++;
4783       _expensive_nodes.at_put(j++, _expensive_nodes.at(i));
4784       continue;
4785     }
4786     if (identical > 0) {
4787       _expensive_nodes.at_put(j++, _expensive_nodes.at(i));
4788       identical = 0;
4789     } else {
4790       Node* n = _expensive_nodes.at(i);
4791       igvn.replace_input_of(n, 0, nullptr);
4792       igvn.hash_insert(n);
4793       modified = true;
4794     }
4795   }
4796   if (identical > 0) {
4797     _expensive_nodes.at_put(j++, _expensive_nodes.at(i));
4798   } else if (_expensive_nodes.length() >= 1) {
4799     Node* n = _expensive_nodes.at(i);
4800     igvn.replace_input_of(n, 0, nullptr);
4801     igvn.hash_insert(n);
4802     modified = true;
4803   }
4804   _expensive_nodes.trunc_to(j);
4805   if (modified) {
4806     igvn.optimize();
4807   }
4808 }
4809 
4810 void Compile::add_expensive_node(Node * n) {
4811   assert(!_expensive_nodes.contains(n), "duplicate entry in expensive list");
4812   assert(n->is_expensive(), "expensive nodes with non-null control here only");
4813   assert(!n->is_CFG() && !n->is_Mem(), "no cfg or memory nodes here");
4814   if (OptimizeExpensiveOps) {
4815     _expensive_nodes.append(n);
4816   } else {
4817     // Clear control input and let IGVN optimize expensive nodes if
4818     // OptimizeExpensiveOps is off.
4819     n->set_req(0, nullptr);
4820   }
4821 }
4822 
4823 /**
4824  * Track coarsened Lock and Unlock nodes.
4825  */
4826 
4827 class Lock_List : public Node_List {
4828   uint _origin_cnt;
4829 public:
4830   Lock_List(Arena *a, uint cnt) : Node_List(a), _origin_cnt(cnt) {}
4831   uint origin_cnt() const { return _origin_cnt; }
4832 };
4833 
4834 void Compile::add_coarsened_locks(GrowableArray<AbstractLockNode*>& locks) {
4835   int length = locks.length();
4836   if (length > 0) {
4837     // Have to keep this list until locks elimination during Macro nodes elimination.
4838     Lock_List* locks_list = new (comp_arena()) Lock_List(comp_arena(), length);
4839     AbstractLockNode* alock = locks.at(0);
4840     BoxLockNode* box = alock->box_node()->as_BoxLock();
4841     for (int i = 0; i < length; i++) {
4842       AbstractLockNode* lock = locks.at(i);
4843       assert(lock->is_coarsened(), "expecting only coarsened AbstractLock nodes, but got '%s'[%d] node", lock->Name(), lock->_idx);
4844       locks_list->push(lock);
4845       BoxLockNode* this_box = lock->box_node()->as_BoxLock();
4846       if (this_box != box) {
4847         // Locking regions (BoxLock) could be Unbalanced here:
4848         //  - its coarsened locks were eliminated in earlier
4849         //    macro nodes elimination followed by loop unroll
4850         //  - it is OSR locking region (no Lock node)
4851         // Preserve Unbalanced status in such cases.
4852         if (!this_box->is_unbalanced()) {
4853           this_box->set_coarsened();
4854         }
4855         if (!box->is_unbalanced()) {
4856           box->set_coarsened();
4857         }
4858       }
4859     }
4860     _coarsened_locks.append(locks_list);
4861   }
4862 }
4863 
4864 void Compile::remove_useless_coarsened_locks(Unique_Node_List& useful) {
4865   int count = coarsened_count();
4866   for (int i = 0; i < count; i++) {
4867     Node_List* locks_list = _coarsened_locks.at(i);
4868     for (uint j = 0; j < locks_list->size(); j++) {
4869       Node* lock = locks_list->at(j);
4870       assert(lock->is_AbstractLock(), "sanity");
4871       if (!useful.member(lock)) {
4872         locks_list->yank(lock);
4873       }
4874     }
4875   }
4876 }
4877 
4878 void Compile::remove_coarsened_lock(Node* n) {
4879   if (n->is_AbstractLock()) {
4880     int count = coarsened_count();
4881     for (int i = 0; i < count; i++) {
4882       Node_List* locks_list = _coarsened_locks.at(i);
4883       locks_list->yank(n);
4884     }
4885   }
4886 }
4887 
4888 bool Compile::coarsened_locks_consistent() {
4889   int count = coarsened_count();
4890   for (int i = 0; i < count; i++) {
4891     bool unbalanced = false;
4892     bool modified = false; // track locks kind modifications
4893     Lock_List* locks_list = (Lock_List*)_coarsened_locks.at(i);
4894     uint size = locks_list->size();
4895     if (size == 0) {
4896       unbalanced = false; // All locks were eliminated - good
4897     } else if (size != locks_list->origin_cnt()) {
4898       unbalanced = true; // Some locks were removed from list
4899     } else {
4900       for (uint j = 0; j < size; j++) {
4901         Node* lock = locks_list->at(j);
4902         // All nodes in group should have the same state (modified or not)
4903         if (!lock->as_AbstractLock()->is_coarsened()) {
4904           if (j == 0) {
4905             // first on list was modified, the rest should be too for consistency
4906             modified = true;
4907           } else if (!modified) {
4908             // this lock was modified but previous locks on the list were not
4909             unbalanced = true;
4910             break;
4911           }
4912         } else if (modified) {
4913           // previous locks on list were modified but not this lock
4914           unbalanced = true;
4915           break;
4916         }
4917       }
4918     }
4919     if (unbalanced) {
4920       // unbalanced monitor enter/exit - only some [un]lock nodes were removed or modified
4921 #ifdef ASSERT
4922       if (PrintEliminateLocks) {
4923         tty->print_cr("=== unbalanced coarsened locks ===");
4924         for (uint l = 0; l < size; l++) {
4925           locks_list->at(l)->dump();
4926         }
4927       }
4928 #endif
4929       record_failure(C2Compiler::retry_no_locks_coarsening());
4930       return false;
4931     }
4932   }
4933   return true;
4934 }
4935 
4936 // Mark locking regions (identified by BoxLockNode) as unbalanced if
4937 // locks coarsening optimization removed Lock/Unlock nodes from them.
4938 // Such regions become unbalanced because coarsening only removes part
4939 // of Lock/Unlock nodes in region. As result we can't execute other
4940 // locks elimination optimizations which assume all code paths have
4941 // corresponding pair of Lock/Unlock nodes - they are balanced.
4942 void Compile::mark_unbalanced_boxes() const {
4943   int count = coarsened_count();
4944   for (int i = 0; i < count; i++) {
4945     Node_List* locks_list = _coarsened_locks.at(i);
4946     uint size = locks_list->size();
4947     if (size > 0) {
4948       AbstractLockNode* alock = locks_list->at(0)->as_AbstractLock();
4949       BoxLockNode* box = alock->box_node()->as_BoxLock();
4950       if (alock->is_coarsened()) {
4951         // coarsened_locks_consistent(), which is called before this method, verifies
4952         // that the rest of Lock/Unlock nodes on locks_list are also coarsened.
4953         assert(!box->is_eliminated(), "regions with coarsened locks should not be marked as eliminated");
4954         for (uint j = 1; j < size; j++) {
4955           assert(locks_list->at(j)->as_AbstractLock()->is_coarsened(), "only coarsened locks are expected here");
4956           BoxLockNode* this_box = locks_list->at(j)->as_AbstractLock()->box_node()->as_BoxLock();
4957           if (box != this_box) {
4958             assert(!this_box->is_eliminated(), "regions with coarsened locks should not be marked as eliminated");
4959             box->set_unbalanced();
4960             this_box->set_unbalanced();
4961           }
4962         }
4963       }
4964     }
4965   }
4966 }
4967 
4968 /**
4969  * Remove the speculative part of types and clean up the graph
4970  */
4971 void Compile::remove_speculative_types(PhaseIterGVN &igvn) {
4972   if (UseTypeSpeculation) {
4973     Unique_Node_List worklist;
4974     worklist.push(root());
4975     int modified = 0;
4976     // Go over all type nodes that carry a speculative type, drop the
4977     // speculative part of the type and enqueue the node for an igvn
4978     // which may optimize it out.
4979     for (uint next = 0; next < worklist.size(); ++next) {
4980       Node *n  = worklist.at(next);
4981       if (n->is_Type()) {
4982         TypeNode* tn = n->as_Type();
4983         const Type* t = tn->type();
4984         const Type* t_no_spec = t->remove_speculative();
4985         if (t_no_spec != t) {
4986           bool in_hash = igvn.hash_delete(n);
4987           assert(in_hash || n->hash() == Node::NO_HASH, "node should be in igvn hash table");
4988           tn->set_type(t_no_spec);
4989           igvn.hash_insert(n);
4990           igvn._worklist.push(n); // give it a chance to go away
4991           modified++;
4992         }
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     // Drop the speculative part of all types in the igvn's type table
5004     igvn.remove_speculative_types();
5005     if (modified > 0) {
5006       igvn.optimize();
5007       if (failing())  return;
5008     }
5009 #ifdef ASSERT
5010     // Verify that after the IGVN is over no speculative type has resurfaced
5011     worklist.clear();
5012     worklist.push(root());
5013     for (uint next = 0; next < worklist.size(); ++next) {
5014       Node *n  = worklist.at(next);
5015       const Type* t = igvn.type_or_null(n);
5016       assert((t == nullptr) || (t == t->remove_speculative()), "no more speculative types");
5017       if (n->is_Type()) {
5018         t = n->as_Type()->type();
5019         assert(t == t->remove_speculative(), "no more speculative types");
5020       }
5021       // Iterate over outs - endless loops is unreachable from below
5022       for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
5023         Node *m = n->fast_out(i);
5024         if (not_a_node(m)) {
5025           continue;
5026         }
5027         worklist.push(m);
5028       }
5029     }
5030     igvn.check_no_speculative_types();
5031 #endif
5032   }
5033 }
5034 
5035 // Auxiliary methods to support randomized stressing/fuzzing.
5036 
5037 void Compile::initialize_stress_seed(const DirectiveSet* directive) {
5038   if (FLAG_IS_DEFAULT(StressSeed) || (FLAG_IS_ERGO(StressSeed) && directive->RepeatCompilationOption)) {
5039     _stress_seed = static_cast<uint>(Ticks::now().nanoseconds());
5040     FLAG_SET_ERGO(StressSeed, _stress_seed);
5041   } else {
5042     _stress_seed = StressSeed;
5043   }
5044   if (_log != nullptr) {
5045     _log->elem("stress_test seed='%u'", _stress_seed);
5046   }
5047 }
5048 
5049 int Compile::random() {
5050   _stress_seed = os::next_random(_stress_seed);
5051   return static_cast<int>(_stress_seed);
5052 }
5053 
5054 // This method can be called the arbitrary number of times, with current count
5055 // as the argument. The logic allows selecting a single candidate from the
5056 // running list of candidates as follows:
5057 //    int count = 0;
5058 //    Cand* selected = null;
5059 //    while(cand = cand->next()) {
5060 //      if (randomized_select(++count)) {
5061 //        selected = cand;
5062 //      }
5063 //    }
5064 //
5065 // Including count equalizes the chances any candidate is "selected".
5066 // This is useful when we don't have the complete list of candidates to choose
5067 // from uniformly. In this case, we need to adjust the randomicity of the
5068 // selection, or else we will end up biasing the selection towards the latter
5069 // candidates.
5070 //
5071 // Quick back-envelope calculation shows that for the list of n candidates
5072 // the equal probability for the candidate to persist as "best" can be
5073 // achieved by replacing it with "next" k-th candidate with the probability
5074 // of 1/k. It can be easily shown that by the end of the run, the
5075 // probability for any candidate is converged to 1/n, thus giving the
5076 // uniform distribution among all the candidates.
5077 //
5078 // We don't care about the domain size as long as (RANDOMIZED_DOMAIN / count) is large.
5079 #define RANDOMIZED_DOMAIN_POW 29
5080 #define RANDOMIZED_DOMAIN (1 << RANDOMIZED_DOMAIN_POW)
5081 #define RANDOMIZED_DOMAIN_MASK ((1 << (RANDOMIZED_DOMAIN_POW + 1)) - 1)
5082 bool Compile::randomized_select(int count) {
5083   assert(count > 0, "only positive");
5084   return (random() & RANDOMIZED_DOMAIN_MASK) < (RANDOMIZED_DOMAIN / count);
5085 }
5086 
5087 #ifdef ASSERT
5088 // Failures are geometrically distributed with probability 1/StressBailoutMean.
5089 bool Compile::fail_randomly() {
5090   if ((random() % StressBailoutMean) != 0) {
5091     return false;
5092   }
5093   record_failure("StressBailout");
5094   return true;
5095 }
5096 
5097 bool Compile::failure_is_artificial() {
5098   return C->failure_reason_is("StressBailout");
5099 }
5100 #endif
5101 
5102 CloneMap&     Compile::clone_map()                 { return _clone_map; }
5103 void          Compile::set_clone_map(Dict* d)      { _clone_map._dict = d; }
5104 
5105 void NodeCloneInfo::dump_on(outputStream* st) const {
5106   st->print(" {%d:%d} ", idx(), gen());
5107 }
5108 
5109 void CloneMap::clone(Node* old, Node* nnn, int gen) {
5110   uint64_t val = value(old->_idx);
5111   NodeCloneInfo cio(val);
5112   assert(val != 0, "old node should be in the map");
5113   NodeCloneInfo cin(cio.idx(), gen + cio.gen());
5114   insert(nnn->_idx, cin.get());
5115 #ifndef PRODUCT
5116   if (is_debug()) {
5117     tty->print_cr("CloneMap::clone inserted node %d info {%d:%d} into CloneMap", nnn->_idx, cin.idx(), cin.gen());
5118   }
5119 #endif
5120 }
5121 
5122 void CloneMap::verify_insert_and_clone(Node* old, Node* nnn, int gen) {
5123   NodeCloneInfo cio(value(old->_idx));
5124   if (cio.get() == 0) {
5125     cio.set(old->_idx, 0);
5126     insert(old->_idx, cio.get());
5127 #ifndef PRODUCT
5128     if (is_debug()) {
5129       tty->print_cr("CloneMap::verify_insert_and_clone inserted node %d info {%d:%d} into CloneMap", old->_idx, cio.idx(), cio.gen());
5130     }
5131 #endif
5132   }
5133   clone(old, nnn, gen);
5134 }
5135 
5136 int CloneMap::max_gen() const {
5137   int g = 0;
5138   DictI di(_dict);
5139   for(; di.test(); ++di) {
5140     int t = gen(di._key);
5141     if (g < t) {
5142       g = t;
5143 #ifndef PRODUCT
5144       if (is_debug()) {
5145         tty->print_cr("CloneMap::max_gen() update max=%d from %d", g, _2_node_idx_t(di._key));
5146       }
5147 #endif
5148     }
5149   }
5150   return g;
5151 }
5152 
5153 void CloneMap::dump(node_idx_t key, outputStream* st) const {
5154   uint64_t val = value(key);
5155   if (val != 0) {
5156     NodeCloneInfo ni(val);
5157     ni.dump_on(st);
5158   }
5159 }
5160 
5161 void Compile::shuffle_macro_nodes() {
5162   if (_macro_nodes.length() < 2) {
5163     return;
5164   }
5165   for (uint i = _macro_nodes.length() - 1; i >= 1; i--) {
5166     uint j = C->random() % (i + 1);
5167     swap(_macro_nodes.at(i), _macro_nodes.at(j));
5168   }
5169 }
5170 
5171 // Move Allocate nodes to the start of the list
5172 void Compile::sort_macro_nodes() {
5173   int count = macro_count();
5174   int allocates = 0;
5175   for (int i = 0; i < count; i++) {
5176     Node* n = macro_node(i);
5177     if (n->is_Allocate()) {
5178       if (i != allocates) {
5179         Node* tmp = macro_node(allocates);
5180         _macro_nodes.at_put(allocates, n);
5181         _macro_nodes.at_put(i, tmp);
5182       }
5183       allocates++;
5184     }
5185   }
5186 }
5187 
5188 void Compile::print_method(CompilerPhaseType cpt, int level, Node* n) {
5189   if (failing_internal()) { return; } // failing_internal to not stress bailouts from printing code.
5190   EventCompilerPhase event(UNTIMED);
5191   if (event.should_commit()) {
5192     CompilerEvent::PhaseEvent::post(event, C->_latest_stage_start_counter, cpt, C->_compile_id, level);
5193   }
5194 #ifndef PRODUCT
5195   ResourceMark rm;
5196   stringStream ss;
5197   ss.print_raw(CompilerPhaseTypeHelper::to_description(cpt));
5198   int iter = ++_igv_phase_iter[cpt];
5199   if (iter > 1) {
5200     ss.print(" %d", iter);
5201   }
5202   if (n != nullptr) {
5203     ss.print(": %d %s", n->_idx, NodeClassNames[n->Opcode()]);
5204     if (n->is_Call()) {
5205       CallNode* call = n->as_Call();
5206       if (call->_name != nullptr) {
5207         // E.g. uncommon traps etc.
5208         ss.print(" - %s", call->_name);
5209       } else if (call->is_CallJava()) {
5210         CallJavaNode* call_java = call->as_CallJava();
5211         if (call_java->method() != nullptr) {
5212           ss.print(" -");
5213           call_java->method()->print_short_name(&ss);
5214         }
5215       }
5216     }
5217   }
5218 
5219   const char* name = ss.as_string();
5220   if (should_print_igv(level)) {
5221     _igv_printer->print_graph(name);
5222   }
5223   if (should_print_phase(level)) {
5224     print_phase(name);
5225   }
5226   if (should_print_ideal_phase(cpt)) {
5227     print_ideal_ir(CompilerPhaseTypeHelper::to_name(cpt));
5228   }
5229 #endif
5230   C->_latest_stage_start_counter.stamp();
5231 }
5232 
5233 // Only used from CompileWrapper
5234 void Compile::begin_method() {
5235 #ifndef PRODUCT
5236   if (_method != nullptr && should_print_igv(1)) {
5237     _igv_printer->begin_method();
5238   }
5239 #endif
5240   C->_latest_stage_start_counter.stamp();
5241 }
5242 
5243 // Only used from CompileWrapper
5244 void Compile::end_method() {
5245   EventCompilerPhase event(UNTIMED);
5246   if (event.should_commit()) {
5247     CompilerEvent::PhaseEvent::post(event, C->_latest_stage_start_counter, PHASE_END, C->_compile_id, 1);
5248   }
5249 
5250 #ifndef PRODUCT
5251   if (_method != nullptr && should_print_igv(1)) {
5252     _igv_printer->end_method();
5253   }
5254 #endif
5255 }
5256 
5257 #ifndef PRODUCT
5258 bool Compile::should_print_phase(const int level) const {
5259   return PrintPhaseLevel > 0 && directive()->PhasePrintLevelOption >= level &&
5260          _method != nullptr; // Do not print phases for stubs.
5261 }
5262 
5263 bool Compile::should_print_ideal_phase(CompilerPhaseType cpt) const {
5264   return _directive->should_print_ideal_phase(cpt);
5265 }
5266 
5267 void Compile::init_igv() {
5268   if (_igv_printer == nullptr) {
5269     _igv_printer = IdealGraphPrinter::printer();
5270     _igv_printer->set_compile(this);
5271   }
5272 }
5273 
5274 bool Compile::should_print_igv(const int level) {
5275   PRODUCT_RETURN_(return false;);
5276 
5277   if (PrintIdealGraphLevel < 0) { // disabled by the user
5278     return false;
5279   }
5280 
5281   bool need = directive()->IGVPrintLevelOption >= level;
5282   if (need) {
5283     Compile::init_igv();
5284   }
5285   return need;
5286 }
5287 
5288 IdealGraphPrinter* Compile::_debug_file_printer = nullptr;
5289 IdealGraphPrinter* Compile::_debug_network_printer = nullptr;
5290 
5291 // Called from debugger. Prints method to the default file with the default phase name.
5292 // This works regardless of any Ideal Graph Visualizer flags set or not.
5293 // Use in debugger (gdb/rr): p igv_print($sp, $fp, $pc).
5294 void igv_print(void* sp, void* fp, void* pc) {
5295   frame fr(sp, fp, pc);
5296   Compile::current()->igv_print_method_to_file(nullptr, false, &fr);
5297 }
5298 
5299 // Same as igv_print() above but with a specified phase name.
5300 void igv_print(const char* phase_name, void* sp, void* fp, void* pc) {
5301   frame fr(sp, fp, pc);
5302   Compile::current()->igv_print_method_to_file(phase_name, false, &fr);
5303 }
5304 
5305 // Called from debugger. Prints method with the default phase name to the default network or the one specified with
5306 // the network flags for the Ideal Graph Visualizer, or to the default file depending on the 'network' argument.
5307 // This works regardless of any Ideal Graph Visualizer flags set or not.
5308 // Use in debugger (gdb/rr): p igv_print(true, $sp, $fp, $pc).
5309 void igv_print(bool network, void* sp, void* fp, void* pc) {
5310   frame fr(sp, fp, pc);
5311   if (network) {
5312     Compile::current()->igv_print_method_to_network(nullptr, &fr);
5313   } else {
5314     Compile::current()->igv_print_method_to_file(nullptr, false, &fr);
5315   }
5316 }
5317 
5318 // Same as igv_print(bool network, ...) above but with a specified phase name.
5319 // Use in debugger (gdb/rr): p igv_print(true, "MyPhase", $sp, $fp, $pc).
5320 void igv_print(bool network, const char* phase_name, void* sp, void* fp, void* pc) {
5321   frame fr(sp, fp, pc);
5322   if (network) {
5323     Compile::current()->igv_print_method_to_network(phase_name, &fr);
5324   } else {
5325     Compile::current()->igv_print_method_to_file(phase_name, false, &fr);
5326   }
5327 }
5328 
5329 // Called from debugger. Normal write to the default _printer. Only works if Ideal Graph Visualizer printing flags are set.
5330 void igv_print_default() {
5331   Compile::current()->print_method(PHASE_DEBUG, 0);
5332 }
5333 
5334 // Called from debugger, especially when replaying a trace in which the program state cannot be altered like with rr replay.
5335 // A method is appended to an existing default file with the default phase name. This means that igv_append() must follow
5336 // an earlier igv_print(*) call which sets up the file. This works regardless of any Ideal Graph Visualizer flags set or not.
5337 // Use in debugger (gdb/rr): p igv_append($sp, $fp, $pc).
5338 void igv_append(void* sp, void* fp, void* pc) {
5339   frame fr(sp, fp, pc);
5340   Compile::current()->igv_print_method_to_file(nullptr, true, &fr);
5341 }
5342 
5343 // Same as igv_append(...) above but with a specified phase name.
5344 // Use in debugger (gdb/rr): p igv_append("MyPhase", $sp, $fp, $pc).
5345 void igv_append(const char* phase_name, void* sp, void* fp, void* pc) {
5346   frame fr(sp, fp, pc);
5347   Compile::current()->igv_print_method_to_file(phase_name, true, &fr);
5348 }
5349 
5350 void Compile::igv_print_method_to_file(const char* phase_name, bool append, const frame* fr) {
5351   const char* file_name = "custom_debug.xml";
5352   if (_debug_file_printer == nullptr) {
5353     _debug_file_printer = new IdealGraphPrinter(C, file_name, append);
5354   } else {
5355     _debug_file_printer->update_compiled_method(C->method());
5356   }
5357   tty->print_cr("Method %s to %s", append ? "appended" : "printed", file_name);
5358   _debug_file_printer->print_graph(phase_name, fr);
5359 }
5360 
5361 void Compile::igv_print_method_to_network(const char* phase_name, const frame* fr) {
5362   ResourceMark rm;
5363   GrowableArray<const Node*> empty_list;
5364   igv_print_graph_to_network(phase_name, empty_list, fr);
5365 }
5366 
5367 void Compile::igv_print_graph_to_network(const char* name, GrowableArray<const Node*>& visible_nodes, const frame* fr) {
5368   if (_debug_network_printer == nullptr) {
5369     _debug_network_printer = new IdealGraphPrinter(C);
5370   } else {
5371     _debug_network_printer->update_compiled_method(C->method());
5372   }
5373   tty->print_cr("Method printed over network stream to IGV");
5374   _debug_network_printer->print(name, C->root(), visible_nodes, fr);
5375 }
5376 #endif // !PRODUCT
5377 
5378 Node* Compile::narrow_value(BasicType bt, Node* value, const Type* type, PhaseGVN* phase, bool transform_res) {
5379   if (type != nullptr && phase->type(value)->higher_equal(type)) {
5380     return value;
5381   }
5382   Node* result = nullptr;
5383   if (bt == T_BYTE) {
5384     result = phase->transform(new LShiftINode(value, phase->intcon(24)));
5385     result = new RShiftINode(result, phase->intcon(24));
5386   } else if (bt == T_BOOLEAN) {
5387     result = new AndINode(value, phase->intcon(0xFF));
5388   } else if (bt == T_CHAR) {
5389     result = new AndINode(value,phase->intcon(0xFFFF));
5390   } else {
5391     assert(bt == T_SHORT, "unexpected narrow type");
5392     result = phase->transform(new LShiftINode(value, phase->intcon(16)));
5393     result = new RShiftINode(result, phase->intcon(16));
5394   }
5395   if (transform_res) {
5396     result = phase->transform(result);
5397   }
5398   return result;
5399 }
5400 
5401 void Compile::record_method_not_compilable_oom() {
5402   record_method_not_compilable(CompilationMemoryStatistic::failure_reason_memlimit());
5403 }
5404 
5405 #ifndef PRODUCT
5406 // Collects all the control inputs from nodes on the worklist and from their data dependencies
5407 static void find_candidate_control_inputs(Unique_Node_List& worklist, Unique_Node_List& candidates) {
5408   // Follow non-control edges until we reach CFG nodes
5409   for (uint i = 0; i < worklist.size(); i++) {
5410     const Node* n = worklist.at(i);
5411     for (uint j = 0; j < n->req(); j++) {
5412       Node* in = n->in(j);
5413       if (in == nullptr || in->is_Root()) {
5414         continue;
5415       }
5416       if (in->is_CFG()) {
5417         if (in->is_Call()) {
5418           // The return value of a call is only available if the call did not result in an exception
5419           Node* control_proj_use = in->as_Call()->proj_out(TypeFunc::Control)->unique_out();
5420           if (control_proj_use->is_Catch()) {
5421             Node* fall_through = control_proj_use->as_Catch()->proj_out(CatchProjNode::fall_through_index);
5422             candidates.push(fall_through);
5423             continue;
5424           }
5425         }
5426 
5427         if (in->is_Multi()) {
5428           // We got here by following data inputs so we should only have one control use
5429           // (no IfNode, etc)
5430           assert(!n->is_MultiBranch(), "unexpected node type: %s", n->Name());
5431           candidates.push(in->as_Multi()->proj_out(TypeFunc::Control));
5432         } else {
5433           candidates.push(in);
5434         }
5435       } else {
5436         worklist.push(in);
5437       }
5438     }
5439   }
5440 }
5441 
5442 // Returns the candidate node that is a descendant to all the other candidates
5443 static Node* pick_control(Unique_Node_List& candidates) {
5444   Unique_Node_List worklist;
5445   worklist.copy(candidates);
5446 
5447   // Traverse backwards through the CFG
5448   for (uint i = 0; i < worklist.size(); i++) {
5449     const Node* n = worklist.at(i);
5450     if (n->is_Root()) {
5451       continue;
5452     }
5453     for (uint j = 0; j < n->req(); j++) {
5454       // Skip backedge of loops to avoid cycles
5455       if (n->is_Loop() && j == LoopNode::LoopBackControl) {
5456         continue;
5457       }
5458 
5459       Node* pred = n->in(j);
5460       if (pred != nullptr && pred != n && pred->is_CFG()) {
5461         worklist.push(pred);
5462         // if pred is an ancestor of n, then pred is an ancestor to at least one candidate
5463         candidates.remove(pred);
5464       }
5465     }
5466   }
5467 
5468   assert(candidates.size() == 1, "unexpected control flow");
5469   return candidates.at(0);
5470 }
5471 
5472 // Initialize a parameter input for a debug print call, using a placeholder for jlong and jdouble
5473 static void debug_print_init_parm(Node* call, Node* parm, Node* half, int* pos) {
5474   call->init_req((*pos)++, parm);
5475   const BasicType bt = parm->bottom_type()->basic_type();
5476   if (bt == T_LONG || bt == T_DOUBLE) {
5477     call->init_req((*pos)++, half);
5478   }
5479 }
5480 
5481 Node* Compile::make_debug_print_call(const char* str, address call_addr, PhaseGVN* gvn,
5482                               Node* parm0, Node* parm1,
5483                               Node* parm2, Node* parm3,
5484                               Node* parm4, Node* parm5,
5485                               Node* parm6) const {
5486   Node* str_node = gvn->transform(new ConPNode(TypeRawPtr::make(((address) str))));
5487   const TypeFunc* type = OptoRuntime::debug_print_Type(parm0, parm1, parm2, parm3, parm4, parm5, parm6);
5488   Node* call = new CallLeafNode(type, call_addr, "debug_print", TypeRawPtr::BOTTOM);
5489 
5490   // find the most suitable control input
5491   Unique_Node_List worklist, candidates;
5492   if (parm0 != nullptr) { worklist.push(parm0);
5493   if (parm1 != nullptr) { worklist.push(parm1);
5494   if (parm2 != nullptr) { worklist.push(parm2);
5495   if (parm3 != nullptr) { worklist.push(parm3);
5496   if (parm4 != nullptr) { worklist.push(parm4);
5497   if (parm5 != nullptr) { worklist.push(parm5);
5498   if (parm6 != nullptr) { worklist.push(parm6);
5499   /* close each nested if ===> */  } } } } } } }
5500   find_candidate_control_inputs(worklist, candidates);
5501   Node* control = nullptr;
5502   if (candidates.size() == 0) {
5503     control = C->start()->proj_out(TypeFunc::Control);
5504   } else {
5505     control = pick_control(candidates);
5506   }
5507 
5508   // find all the previous users of the control we picked
5509   GrowableArray<Node*> users_of_control;
5510   for (DUIterator_Fast kmax, i = control->fast_outs(kmax); i < kmax; i++) {
5511     Node* use = control->fast_out(i);
5512     if (use->is_CFG() && use != control) {
5513       users_of_control.push(use);
5514     }
5515   }
5516 
5517   // we do not actually care about IO and memory as it uses neither
5518   call->init_req(TypeFunc::Control,   control);
5519   call->init_req(TypeFunc::I_O,       top());
5520   call->init_req(TypeFunc::Memory,    top());
5521   call->init_req(TypeFunc::FramePtr,  C->start()->proj_out(TypeFunc::FramePtr));
5522   call->init_req(TypeFunc::ReturnAdr, top());
5523 
5524   int pos = TypeFunc::Parms;
5525   call->init_req(pos++, str_node);
5526   if (parm0 != nullptr) { debug_print_init_parm(call, parm0, top(), &pos);
5527   if (parm1 != nullptr) { debug_print_init_parm(call, parm1, top(), &pos);
5528   if (parm2 != nullptr) { debug_print_init_parm(call, parm2, top(), &pos);
5529   if (parm3 != nullptr) { debug_print_init_parm(call, parm3, top(), &pos);
5530   if (parm4 != nullptr) { debug_print_init_parm(call, parm4, top(), &pos);
5531   if (parm5 != nullptr) { debug_print_init_parm(call, parm5, top(), &pos);
5532   if (parm6 != nullptr) { debug_print_init_parm(call, parm6, top(), &pos);
5533   /* close each nested if ===> */  } } } } } } }
5534   assert(call->in(call->req()-1) != nullptr, "must initialize all parms");
5535 
5536   call = gvn->transform(call);
5537   Node* call_control_proj = gvn->transform(new ProjNode(call, TypeFunc::Control));
5538 
5539   // rewire previous users to have the new call as control instead
5540   PhaseIterGVN* igvn = gvn->is_IterGVN();
5541   for (int i = 0; i < users_of_control.length(); i++) {
5542     Node* use = users_of_control.at(i);
5543     for (uint j = 0; j < use->req(); j++) {
5544       if (use->in(j) == control) {
5545         if (igvn != nullptr) {
5546           igvn->replace_input_of(use, j, call_control_proj);
5547         } else {
5548           gvn->hash_delete(use);
5549           use->set_req(j, call_control_proj);
5550           gvn->hash_insert(use);
5551         }
5552       }
5553     }
5554   }
5555 
5556   return call;
5557 }
5558 #endif // !PRODUCT