1 /*
   2  * Copyright (c) 1997, 2026, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "asm/macroAssembler.hpp"
  26 #include "asm/macroAssembler.inline.hpp"
  27 #include "ci/ciFlatArray.hpp"
  28 #include "ci/ciInlineKlass.hpp"
  29 #include "ci/ciReplay.hpp"
  30 #include "classfile/javaClasses.hpp"
  31 #include "code/aotCodeCache.hpp"
  32 #include "code/exceptionHandlerTable.hpp"
  33 #include "code/nmethod.hpp"
  34 #include "compiler/compilationFailureInfo.hpp"
  35 #include "compiler/compilationMemoryStatistic.hpp"
  36 #include "compiler/compileBroker.hpp"
  37 #include "compiler/compileLog.hpp"
  38 #include "compiler/compiler_globals.hpp"
  39 #include "compiler/compilerDefinitions.hpp"
  40 #include "compiler/compilerOracle.hpp"
  41 #include "compiler/disassembler.hpp"
  42 #include "compiler/oopMap.hpp"
  43 #include "gc/shared/barrierSet.hpp"
  44 #include "gc/shared/c2/barrierSetC2.hpp"
  45 #include "jfr/jfrEvents.hpp"
  46 #include "jvm_io.h"
  47 #include "memory/allocation.hpp"
  48 #include "memory/arena.hpp"
  49 #include "memory/resourceArea.hpp"
  50 #include "opto/addnode.hpp"
  51 #include "opto/block.hpp"
  52 #include "opto/c2compiler.hpp"
  53 #include "opto/callGenerator.hpp"
  54 #include "opto/callnode.hpp"
  55 #include "opto/castnode.hpp"
  56 #include "opto/cfgnode.hpp"
  57 #include "opto/chaitin.hpp"
  58 #include "opto/compile.hpp"
  59 #include "opto/connode.hpp"
  60 #include "opto/convertnode.hpp"
  61 #include "opto/divnode.hpp"
  62 #include "opto/escape.hpp"
  63 #include "opto/idealGraphPrinter.hpp"
  64 #include "opto/inlinetypenode.hpp"
  65 #include "opto/locknode.hpp"
  66 #include "opto/loopnode.hpp"
  67 #include "opto/machnode.hpp"
  68 #include "opto/macro.hpp"
  69 #include "opto/matcher.hpp"
  70 #include "opto/mathexactnode.hpp"
  71 #include "opto/memnode.hpp"
  72 #include "opto/movenode.hpp"
  73 #include "opto/mulnode.hpp"
  74 #include "opto/multnode.hpp"
  75 #include "opto/narrowptrnode.hpp"
  76 #include "opto/node.hpp"
  77 #include "opto/opaquenode.hpp"
  78 #include "opto/opcodes.hpp"
  79 #include "opto/output.hpp"
  80 #include "opto/parse.hpp"
  81 #include "opto/phaseX.hpp"
  82 #include "opto/rootnode.hpp"
  83 #include "opto/runtime.hpp"
  84 #include "opto/stringopts.hpp"
  85 #include "opto/type.hpp"
  86 #include "opto/vector.hpp"
  87 #include "opto/vectornode.hpp"
  88 #include "runtime/arguments.hpp"
  89 #include "runtime/globals_extension.hpp"
  90 #include "runtime/sharedRuntime.hpp"
  91 #include "runtime/signature.hpp"
  92 #include "runtime/stubRoutines.hpp"
  93 #include "runtime/timer.hpp"
  94 #include "utilities/align.hpp"
  95 #include "utilities/copy.hpp"
  96 #include "utilities/hashTable.hpp"
  97 #include "utilities/macros.hpp"
  98 
  99 // -------------------- Compile::mach_constant_base_node -----------------------
 100 // Constant table base node singleton.
 101 MachConstantBaseNode* Compile::mach_constant_base_node() {
 102   if (_mach_constant_base_node == nullptr) {
 103     _mach_constant_base_node = new MachConstantBaseNode();
 104     _mach_constant_base_node->add_req(C->root());
 105   }
 106   return _mach_constant_base_node;
 107 }
 108 
 109 
 110 /// Support for intrinsics.
 111 
 112 // Return the index at which m must be inserted (or already exists).
 113 // The sort order is by the address of the ciMethod, with is_virtual as minor key.
 114 class IntrinsicDescPair {
 115  private:
 116   ciMethod* _m;
 117   bool _is_virtual;
 118  public:
 119   IntrinsicDescPair(ciMethod* m, bool is_virtual) : _m(m), _is_virtual(is_virtual) {}
 120   static int compare(IntrinsicDescPair* const& key, CallGenerator* const& elt) {
 121     ciMethod* m= elt->method();
 122     ciMethod* key_m = key->_m;
 123     if (key_m < m)      return -1;
 124     else if (key_m > m) return 1;
 125     else {
 126       bool is_virtual = elt->is_virtual();
 127       bool key_virtual = key->_is_virtual;
 128       if (key_virtual < is_virtual)      return -1;
 129       else if (key_virtual > is_virtual) return 1;
 130       else                               return 0;
 131     }
 132   }
 133 };
 134 int Compile::intrinsic_insertion_index(ciMethod* m, bool is_virtual, bool& found) {
 135 #ifdef ASSERT
 136   for (int i = 1; i < _intrinsics.length(); i++) {
 137     CallGenerator* cg1 = _intrinsics.at(i-1);
 138     CallGenerator* cg2 = _intrinsics.at(i);
 139     assert(cg1->method() != cg2->method()
 140            ? cg1->method()     < cg2->method()
 141            : cg1->is_virtual() < cg2->is_virtual(),
 142            "compiler intrinsics list must stay sorted");
 143   }
 144 #endif
 145   IntrinsicDescPair pair(m, is_virtual);
 146   return _intrinsics.find_sorted<IntrinsicDescPair*, IntrinsicDescPair::compare>(&pair, found);
 147 }
 148 
 149 void Compile::register_intrinsic(CallGenerator* cg) {
 150   bool found = false;
 151   int index = intrinsic_insertion_index(cg->method(), cg->is_virtual(), found);
 152   assert(!found, "registering twice");
 153   _intrinsics.insert_before(index, cg);
 154   assert(find_intrinsic(cg->method(), cg->is_virtual()) == cg, "registration worked");
 155 }
 156 
 157 CallGenerator* Compile::find_intrinsic(ciMethod* m, bool is_virtual) {
 158   assert(m->is_loaded(), "don't try this on unloaded methods");
 159   if (_intrinsics.length() > 0) {
 160     bool found = false;
 161     int index = intrinsic_insertion_index(m, is_virtual, found);
 162      if (found) {
 163       return _intrinsics.at(index);
 164     }
 165   }
 166   // Lazily create intrinsics for intrinsic IDs well-known in the runtime.
 167   if (m->intrinsic_id() != vmIntrinsics::_none &&
 168       m->intrinsic_id() <= vmIntrinsics::LAST_COMPILER_INLINE) {
 169     CallGenerator* cg = make_vm_intrinsic(m, is_virtual);
 170     if (cg != nullptr) {
 171       // Save it for next time:
 172       register_intrinsic(cg);
 173       return cg;
 174     } else {
 175       gather_intrinsic_statistics(m->intrinsic_id(), is_virtual, _intrinsic_disabled);
 176     }
 177   }
 178   return nullptr;
 179 }
 180 
 181 // Compile::make_vm_intrinsic is defined in library_call.cpp.
 182 
 183 #ifndef PRODUCT
 184 // statistics gathering...
 185 
 186 juint  Compile::_intrinsic_hist_count[vmIntrinsics::number_of_intrinsics()] = {0};
 187 jubyte Compile::_intrinsic_hist_flags[vmIntrinsics::number_of_intrinsics()] = {0};
 188 
 189 inline int as_int(vmIntrinsics::ID id) {
 190   return vmIntrinsics::as_int(id);
 191 }
 192 
 193 bool Compile::gather_intrinsic_statistics(vmIntrinsics::ID id, bool is_virtual, int flags) {
 194   assert(id > vmIntrinsics::_none && id < vmIntrinsics::ID_LIMIT, "oob");
 195   int oflags = _intrinsic_hist_flags[as_int(id)];
 196   assert(flags != 0, "what happened?");
 197   if (is_virtual) {
 198     flags |= _intrinsic_virtual;
 199   }
 200   bool changed = (flags != oflags);
 201   if ((flags & _intrinsic_worked) != 0) {
 202     juint count = (_intrinsic_hist_count[as_int(id)] += 1);
 203     if (count == 1) {
 204       changed = true;           // first time
 205     }
 206     // increment the overall count also:
 207     _intrinsic_hist_count[as_int(vmIntrinsics::_none)] += 1;
 208   }
 209   if (changed) {
 210     if (((oflags ^ flags) & _intrinsic_virtual) != 0) {
 211       // Something changed about the intrinsic's virtuality.
 212       if ((flags & _intrinsic_virtual) != 0) {
 213         // This is the first use of this intrinsic as a virtual call.
 214         if (oflags != 0) {
 215           // We already saw it as a non-virtual, so note both cases.
 216           flags |= _intrinsic_both;
 217         }
 218       } else if ((oflags & _intrinsic_both) == 0) {
 219         // This is the first use of this intrinsic as a non-virtual
 220         flags |= _intrinsic_both;
 221       }
 222     }
 223     _intrinsic_hist_flags[as_int(id)] = (jubyte) (oflags | flags);
 224   }
 225   // update the overall flags also:
 226   _intrinsic_hist_flags[as_int(vmIntrinsics::_none)] |= (jubyte) flags;
 227   return changed;
 228 }
 229 
 230 static char* format_flags(int flags, char* buf) {
 231   buf[0] = 0;
 232   if ((flags & Compile::_intrinsic_worked) != 0)    strcat(buf, ",worked");
 233   if ((flags & Compile::_intrinsic_failed) != 0)    strcat(buf, ",failed");
 234   if ((flags & Compile::_intrinsic_disabled) != 0)  strcat(buf, ",disabled");
 235   if ((flags & Compile::_intrinsic_virtual) != 0)   strcat(buf, ",virtual");
 236   if ((flags & Compile::_intrinsic_both) != 0)      strcat(buf, ",nonvirtual");
 237   if (buf[0] == 0)  strcat(buf, ",");
 238   assert(buf[0] == ',', "must be");
 239   return &buf[1];
 240 }
 241 
 242 void Compile::print_intrinsic_statistics() {
 243   char flagsbuf[100];
 244   ttyLocker ttyl;
 245   if (xtty != nullptr)  xtty->head("statistics type='intrinsic'");
 246   tty->print_cr("Compiler intrinsic usage:");
 247   juint total = _intrinsic_hist_count[as_int(vmIntrinsics::_none)];
 248   if (total == 0)  total = 1;  // avoid div0 in case of no successes
 249   #define PRINT_STAT_LINE(name, c, f) \
 250     tty->print_cr("  %4d (%4.1f%%) %s (%s)", (int)(c), ((c) * 100.0) / total, name, f);
 251   for (auto id : EnumRange<vmIntrinsicID>{}) {
 252     int   flags = _intrinsic_hist_flags[as_int(id)];
 253     juint count = _intrinsic_hist_count[as_int(id)];
 254     if ((flags | count) != 0) {
 255       PRINT_STAT_LINE(vmIntrinsics::name_at(id), count, format_flags(flags, flagsbuf));
 256     }
 257   }
 258   PRINT_STAT_LINE("total", total, format_flags(_intrinsic_hist_flags[as_int(vmIntrinsics::_none)], flagsbuf));
 259   if (xtty != nullptr)  xtty->tail("statistics");
 260 }
 261 
 262 void Compile::print_statistics() {
 263   { ttyLocker ttyl;
 264     if (xtty != nullptr)  xtty->head("statistics type='opto'");
 265     Parse::print_statistics();
 266     PhaseStringOpts::print_statistics();
 267     PhaseCCP::print_statistics();
 268     PhaseRegAlloc::print_statistics();
 269     PhaseOutput::print_statistics();
 270     PhasePeephole::print_statistics();
 271     PhaseIdealLoop::print_statistics();
 272     ConnectionGraph::print_statistics();
 273     PhaseMacroExpand::print_statistics();
 274     if (xtty != nullptr)  xtty->tail("statistics");
 275   }
 276   if (_intrinsic_hist_flags[as_int(vmIntrinsics::_none)] != 0) {
 277     // put this under its own <statistics> element.
 278     print_intrinsic_statistics();
 279   }
 280 }
 281 #endif //PRODUCT
 282 
 283 void Compile::gvn_replace_by(Node* n, Node* nn) {
 284   for (DUIterator_Last imin, i = n->last_outs(imin); i >= imin; ) {
 285     Node* use = n->last_out(i);
 286     bool is_in_table = initial_gvn()->hash_delete(use);
 287     uint uses_found = 0;
 288     for (uint j = 0; j < use->len(); j++) {
 289       if (use->in(j) == n) {
 290         if (j < use->req())
 291           use->set_req(j, nn);
 292         else
 293           use->set_prec(j, nn);
 294         uses_found++;
 295       }
 296     }
 297     if (is_in_table) {
 298       // reinsert into table
 299       initial_gvn()->hash_find_insert(use);
 300     }
 301     record_for_igvn(use);
 302     PhaseIterGVN::add_users_of_use_to_worklist(nn, use, *_igvn_worklist);
 303     i -= uses_found;    // we deleted 1 or more copies of this edge
 304   }
 305 }
 306 
 307 
 308 // Identify all nodes that are reachable from below, useful.
 309 // Use breadth-first pass that records state in a Unique_Node_List,
 310 // recursive traversal is slower.
 311 void Compile::identify_useful_nodes(Unique_Node_List &useful) {
 312   int estimated_worklist_size = live_nodes();
 313   useful.map( estimated_worklist_size, nullptr );  // preallocate space
 314 
 315   // Initialize worklist
 316   if (root() != nullptr)  { useful.push(root()); }
 317   // If 'top' is cached, declare it useful to preserve cached node
 318   if (cached_top_node())  { useful.push(cached_top_node()); }
 319 
 320   // Push all useful nodes onto the list, breadthfirst
 321   for( uint next = 0; next < useful.size(); ++next ) {
 322     assert( next < unique(), "Unique useful nodes < total nodes");
 323     Node *n  = useful.at(next);
 324     uint max = n->len();
 325     for( uint i = 0; i < max; ++i ) {
 326       Node *m = n->in(i);
 327       if (not_a_node(m))  continue;
 328       useful.push(m);
 329     }
 330   }
 331 }
 332 
 333 // Update dead_node_list with any missing dead nodes using useful
 334 // list. Consider all non-useful nodes to be useless i.e., dead nodes.
 335 void Compile::update_dead_node_list(Unique_Node_List &useful) {
 336   uint max_idx = unique();
 337   VectorSet& useful_node_set = useful.member_set();
 338 
 339   for (uint node_idx = 0; node_idx < max_idx; node_idx++) {
 340     // If node with index node_idx is not in useful set,
 341     // mark it as dead in dead node list.
 342     if (!useful_node_set.test(node_idx)) {
 343       record_dead_node(node_idx);
 344     }
 345   }
 346 }
 347 
 348 void Compile::remove_useless_late_inlines(GrowableArray<CallGenerator*>* inlines, Unique_Node_List &useful) {
 349   int shift = 0;
 350   for (int i = 0; i < inlines->length(); i++) {
 351     CallGenerator* cg = inlines->at(i);
 352     if (useful.member(cg->call_node())) {
 353       if (shift > 0) {
 354         inlines->at_put(i - shift, cg);
 355       }
 356     } else {
 357       shift++; // skip over the dead element
 358     }
 359   }
 360   if (shift > 0) {
 361     inlines->trunc_to(inlines->length() - shift); // remove last elements from compacted array
 362   }
 363 }
 364 
 365 void Compile::remove_useless_late_inlines(GrowableArray<CallGenerator*>* inlines, Node* dead) {
 366   assert(dead != nullptr && dead->is_Call(), "sanity");
 367   int found = 0;
 368   for (int i = 0; i < inlines->length(); i++) {
 369     if (inlines->at(i)->call_node() == dead) {
 370       inlines->remove_at(i);
 371       found++;
 372       NOT_DEBUG( break; ) // elements are unique, so exit early
 373     }
 374   }
 375   assert(found <= 1, "not unique");
 376 }
 377 
 378 template<typename N, ENABLE_IF_SDEFN(std::is_base_of<Node, N>::value)>
 379 void Compile::remove_useless_nodes(GrowableArray<N*>& node_list, Unique_Node_List& useful) {
 380   for (int i = node_list.length() - 1; i >= 0; i--) {
 381     N* node = node_list.at(i);
 382     if (!useful.member(node)) {
 383       node_list.delete_at(i); // replaces i-th with last element which is known to be useful (already processed)
 384     }
 385   }
 386 }
 387 
 388 void Compile::remove_useless_node(Node* dead) {
 389   remove_modified_node(dead);
 390 
 391   // Constant node that has no out-edges and has only one in-edge from
 392   // root is usually dead. However, sometimes reshaping walk makes
 393   // it reachable by adding use edges. So, we will NOT count Con nodes
 394   // as dead to be conservative about the dead node count at any
 395   // given time.
 396   if (!dead->is_Con()) {
 397     record_dead_node(dead->_idx);
 398   }
 399   if (dead->is_macro()) {
 400     remove_macro_node(dead);
 401   }
 402   if (dead->is_expensive()) {
 403     remove_expensive_node(dead);
 404   }
 405   if (dead->is_OpaqueTemplateAssertionPredicate()) {
 406     remove_template_assertion_predicate_opaque(dead->as_OpaqueTemplateAssertionPredicate());
 407   }
 408   if (dead->is_ParsePredicate()) {
 409     remove_parse_predicate(dead->as_ParsePredicate());
 410   }
 411   if (dead->for_post_loop_opts_igvn()) {
 412     remove_from_post_loop_opts_igvn(dead);
 413   }
 414   if (dead->is_InlineType()) {
 415     remove_inline_type(dead);
 416   }
 417   if (dead->is_LoadFlat() || dead->is_StoreFlat()) {
 418     remove_flat_access(dead);
 419   }
 420   if (dead->for_merge_stores_igvn()) {
 421     remove_from_merge_stores_igvn(dead);
 422   }
 423   if (dead->is_Call()) {
 424     remove_useless_late_inlines(                &_late_inlines, dead);
 425     remove_useless_late_inlines(         &_string_late_inlines, dead);
 426     remove_useless_late_inlines(         &_boxing_late_inlines, dead);
 427     remove_useless_late_inlines(&_vector_reboxing_late_inlines, dead);
 428 
 429     if (dead->is_CallStaticJava()) {
 430       remove_unstable_if_trap(dead->as_CallStaticJava(), false);
 431     }
 432   }
 433   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 434   bs->unregister_potential_barrier_node(dead);
 435 }
 436 
 437 // Disconnect all useless nodes by disconnecting those at the boundary.
 438 void Compile::disconnect_useless_nodes(Unique_Node_List& useful, Unique_Node_List& worklist, const Unique_Node_List* root_and_safepoints) {
 439   uint next = 0;
 440   while (next < useful.size()) {
 441     Node *n = useful.at(next++);
 442     if (n->is_SafePoint()) {
 443       // We're done with a parsing phase. Replaced nodes are not valid
 444       // beyond that point.
 445       n->as_SafePoint()->delete_replaced_nodes();
 446     }
 447     // Use raw traversal of out edges since this code removes out edges
 448     int max = n->outcnt();
 449     for (int j = 0; j < max; ++j) {
 450       Node* child = n->raw_out(j);
 451       if (!useful.member(child)) {
 452         assert(!child->is_top() || child != top(),
 453                "If top is cached in Compile object it is in useful list");
 454         // Only need to remove this out-edge to the useless node
 455         n->raw_del_out(j);
 456         --j;
 457         --max;
 458         if (child->is_data_proj_of_pure_function(n)) {
 459           worklist.push(n);
 460         }
 461       }
 462     }
 463     if (n->outcnt() == 1 && n->has_special_unique_user()) {
 464       assert(useful.member(n->unique_out()), "do not push a useless node");
 465       worklist.push(n->unique_out());
 466     }
 467     if (n->outcnt() == 0) {
 468       worklist.push(n);
 469     }
 470   }
 471 
 472   remove_useless_nodes(_macro_nodes,        useful); // remove useless macro nodes
 473   remove_useless_nodes(_parse_predicates,   useful); // remove useless Parse Predicate nodes
 474   // Remove useless Template Assertion Predicate opaque nodes
 475   remove_useless_nodes(_template_assertion_predicate_opaques, useful);
 476   remove_useless_nodes(_expensive_nodes,    useful); // remove useless expensive nodes
 477   remove_useless_nodes(_for_post_loop_igvn, useful); // remove useless node recorded for post loop opts IGVN pass
 478   remove_useless_nodes(_inline_type_nodes,  useful); // remove useless inline type nodes
 479   remove_useless_nodes(_flat_access_nodes, useful);  // remove useless flat access nodes
 480 #ifdef ASSERT
 481   if (_modified_nodes != nullptr) {
 482     _modified_nodes->remove_useless_nodes(useful.member_set());
 483   }
 484 #endif
 485   remove_useless_nodes(_for_merge_stores_igvn, useful); // remove useless node recorded for merge stores IGVN pass
 486   remove_useless_unstable_if_traps(useful);          // remove useless unstable_if traps
 487   remove_useless_coarsened_locks(useful);            // remove useless coarsened locks nodes
 488 #ifdef ASSERT
 489   if (_modified_nodes != nullptr) {
 490     _modified_nodes->remove_useless_nodes(useful.member_set());
 491   }
 492 #endif
 493 
 494   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 495   bs->eliminate_useless_gc_barriers(useful, this);
 496   // clean up the late inline lists
 497   remove_useless_late_inlines(                &_late_inlines, useful);
 498   remove_useless_late_inlines(         &_string_late_inlines, useful);
 499   remove_useless_late_inlines(         &_boxing_late_inlines, useful);
 500   remove_useless_late_inlines(&_vector_reboxing_late_inlines, useful);
 501   DEBUG_ONLY(verify_graph_edges(true /*check for no_dead_code*/, root_and_safepoints);)
 502 }
 503 
 504 // ============================================================================
 505 //------------------------------CompileWrapper---------------------------------
 506 class CompileWrapper : public StackObj {
 507   Compile *const _compile;
 508  public:
 509   CompileWrapper(Compile* compile);
 510 
 511   ~CompileWrapper();
 512 };
 513 
 514 CompileWrapper::CompileWrapper(Compile* compile) : _compile(compile) {
 515   // the Compile* pointer is stored in the current ciEnv:
 516   ciEnv* env = compile->env();
 517   assert(env == ciEnv::current(), "must already be a ciEnv active");
 518   assert(env->compiler_data() == nullptr, "compile already active?");
 519   env->set_compiler_data(compile);
 520   assert(compile == Compile::current(), "sanity");
 521 
 522   compile->set_type_dict(nullptr);
 523   compile->set_clone_map(new Dict(cmpkey, hashkey, _compile->comp_arena()));
 524   compile->clone_map().set_clone_idx(0);
 525   compile->set_type_last_size(0);
 526   compile->set_last_tf(nullptr, nullptr);
 527   compile->set_indexSet_arena(nullptr);
 528   compile->set_indexSet_free_block_list(nullptr);
 529   compile->init_type_arena();
 530   Type::Initialize(compile);
 531   _compile->begin_method();
 532   _compile->clone_map().set_debug(_compile->has_method() && _compile->directive()->CloneMapDebugOption);
 533 }
 534 CompileWrapper::~CompileWrapper() {
 535   // simulate crash during compilation
 536   assert(CICrashAt < 0 || _compile->compile_id() != CICrashAt, "just as planned");
 537 
 538   _compile->end_method();
 539   _compile->env()->set_compiler_data(nullptr);
 540 }
 541 
 542 
 543 //----------------------------print_compile_messages---------------------------
 544 void Compile::print_compile_messages() {
 545 #ifndef PRODUCT
 546   // Check if recompiling
 547   if (!subsume_loads() && PrintOpto) {
 548     // Recompiling without allowing machine instructions to subsume loads
 549     tty->print_cr("*********************************************************");
 550     tty->print_cr("** Bailout: Recompile without subsuming loads          **");
 551     tty->print_cr("*********************************************************");
 552   }
 553   if ((do_escape_analysis() != DoEscapeAnalysis) && PrintOpto) {
 554     // Recompiling without escape analysis
 555     tty->print_cr("*********************************************************");
 556     tty->print_cr("** Bailout: Recompile without escape analysis          **");
 557     tty->print_cr("*********************************************************");
 558   }
 559   if (do_iterative_escape_analysis() != DoEscapeAnalysis && PrintOpto) {
 560     // Recompiling without iterative escape analysis
 561     tty->print_cr("*********************************************************");
 562     tty->print_cr("** Bailout: Recompile without iterative escape analysis**");
 563     tty->print_cr("*********************************************************");
 564   }
 565   if (do_reduce_allocation_merges() != ReduceAllocationMerges && PrintOpto) {
 566     // Recompiling without reducing allocation merges
 567     tty->print_cr("*********************************************************");
 568     tty->print_cr("** Bailout: Recompile without reduce allocation merges **");
 569     tty->print_cr("*********************************************************");
 570   }
 571   if ((eliminate_boxing() != EliminateAutoBox) && PrintOpto) {
 572     // Recompiling without boxing elimination
 573     tty->print_cr("*********************************************************");
 574     tty->print_cr("** Bailout: Recompile without boxing elimination       **");
 575     tty->print_cr("*********************************************************");
 576   }
 577   if ((do_locks_coarsening() != EliminateLocks) && PrintOpto) {
 578     // Recompiling without locks coarsening
 579     tty->print_cr("*********************************************************");
 580     tty->print_cr("** Bailout: Recompile without locks coarsening         **");
 581     tty->print_cr("*********************************************************");
 582   }
 583   if (env()->break_at_compile()) {
 584     // Open the debugger when compiling this method.
 585     tty->print("### Breaking when compiling: ");
 586     method()->print_short_name();
 587     tty->cr();
 588     BREAKPOINT;
 589   }
 590 
 591   if( PrintOpto ) {
 592     if (is_osr_compilation()) {
 593       tty->print("[OSR]%3d", _compile_id);
 594     } else {
 595       tty->print("%3d", _compile_id);
 596     }
 597   }
 598 #endif
 599 }
 600 
 601 #ifndef PRODUCT
 602 void Compile::print_phase(const char* phase_name) {
 603   tty->print_cr("%u.\t%s", ++_phase_counter, phase_name);
 604 }
 605 
 606 void Compile::print_ideal_ir(const char* compile_phase_name) const {
 607   // keep the following output all in one block
 608   // This output goes directly to the tty, not the compiler log.
 609   // To enable tools to match it up with the compilation activity,
 610   // be sure to tag this tty output with the compile ID.
 611 
 612   // Node dumping can cause a safepoint, which can break the tty lock.
 613   // Buffer all node dumps, so that all safepoints happen before we lock.
 614   ResourceMark rm;
 615   stringStream ss;
 616 
 617   if (_output == nullptr) {
 618     ss.print_cr("AFTER: %s", compile_phase_name);
 619     // Print out all nodes in ascending order of index.
 620     // It is important that we traverse both inputs and outputs of nodes,
 621     // so that we reach all nodes that are connected to Root.
 622     root()->dump_bfs(MaxNodeLimit, nullptr, "-+S$", &ss);
 623   } else {
 624     // Dump the node blockwise if we have a scheduling
 625     _output->print_scheduling(&ss);
 626   }
 627 
 628   // Check that the lock is not broken by a safepoint.
 629   NoSafepointVerifier nsv;
 630   ttyLocker ttyl;
 631   if (xtty != nullptr) {
 632     xtty->head("ideal compile_id='%d'%s compile_phase='%s'",
 633                compile_id(),
 634                is_osr_compilation() ? " compile_kind='osr'" : "",
 635                compile_phase_name);
 636   }
 637 
 638   tty->print("%s", ss.as_string());
 639 
 640   if (xtty != nullptr) {
 641     xtty->tail("ideal");
 642   }
 643 }
 644 #endif
 645 
 646 // ============================================================================
 647 //------------------------------Compile standard-------------------------------
 648 
 649 // Compile a method.  entry_bci is -1 for normal compilations and indicates
 650 // the continuation bci for on stack replacement.
 651 
 652 
 653 Compile::Compile(ciEnv* ci_env, ciMethod* target, int osr_bci,
 654                  Options options, DirectiveSet* directive)
 655     : Phase(Compiler),
 656       _compile_id(ci_env->compile_id()),
 657       _options(options),
 658       _method(target),
 659       _entry_bci(osr_bci),
 660       _ilt(nullptr),
 661       _stub_function(nullptr),
 662       _stub_name(nullptr),
 663       _stub_id(StubId::NO_STUBID),
 664       _stub_entry_point(nullptr),
 665       _max_node_limit(MaxNodeLimit),
 666       _post_loop_opts_phase(false),
 667       _merge_stores_phase(false),
 668       _allow_macro_nodes(true),
 669       _inlining_progress(false),
 670       _inlining_incrementally(false),
 671       _strength_reduction(false),
 672       _do_cleanup(false),
 673       _has_reserved_stack_access(target->has_reserved_stack_access()),
 674       _has_circular_inline_type(false),
 675 #ifndef PRODUCT
 676       _igv_idx(0),
 677       _trace_opto_output(directive->TraceOptoOutputOption),
 678 #endif
 679       _clinit_barrier_on_entry(false),
 680       _stress_seed(0),
 681       _comp_arena(mtCompiler, Arena::Tag::tag_comp),
 682       _barrier_set_state(BarrierSet::barrier_set()->barrier_set_c2()->create_barrier_state(comp_arena())),
 683       _env(ci_env),
 684       _directive(directive),
 685       _log(ci_env->log()),
 686       _first_failure_details(nullptr),
 687       _intrinsics(comp_arena(), 0, 0, nullptr),
 688       _macro_nodes(comp_arena(), 8, 0, nullptr),
 689       _parse_predicates(comp_arena(), 8, 0, nullptr),
 690       _template_assertion_predicate_opaques(comp_arena(), 8, 0, nullptr),
 691       _expensive_nodes(comp_arena(), 8, 0, nullptr),
 692       _for_post_loop_igvn(comp_arena(), 8, 0, nullptr),
 693       _inline_type_nodes (comp_arena(), 8, 0, nullptr),
 694       _flat_access_nodes(comp_arena(), 8, 0, nullptr),
 695       _for_merge_stores_igvn(comp_arena(), 8, 0, nullptr),
 696       _unstable_if_traps(comp_arena(), 8, 0, nullptr),
 697       _coarsened_locks(comp_arena(), 8, 0, nullptr),
 698       _congraph(nullptr),
 699       NOT_PRODUCT(_igv_printer(nullptr) COMMA)
 700       _unique(0),
 701       _dead_node_count(0),
 702       _dead_node_list(comp_arena()),
 703       _node_arena_one(mtCompiler, Arena::Tag::tag_node),
 704       _node_arena_two(mtCompiler, Arena::Tag::tag_node),
 705       _node_arena(&_node_arena_one),
 706       _mach_constant_base_node(nullptr),
 707       _Compile_types(mtCompiler, Arena::Tag::tag_type),
 708       _initial_gvn(nullptr),
 709       _igvn_worklist(nullptr),
 710       _types(nullptr),
 711       _node_hash(nullptr),
 712       _late_inlines(comp_arena(), 2, 0, nullptr),
 713       _string_late_inlines(comp_arena(), 2, 0, nullptr),
 714       _boxing_late_inlines(comp_arena(), 2, 0, nullptr),
 715       _vector_reboxing_late_inlines(comp_arena(), 2, 0, nullptr),
 716       _late_inlines_pos(0),
 717       _has_mh_late_inlines(false),
 718       _oom(false),
 719       _replay_inline_data(nullptr),
 720       _inline_printer(this),
 721       _java_calls(0),
 722       _inner_loops(0),
 723       _FIRST_STACK_mask(comp_arena()),
 724       _interpreter_frame_size(0),
 725       _regmask_arena(mtCompiler, Arena::Tag::tag_regmask),
 726       _output(nullptr)
 727 #ifndef PRODUCT
 728       ,
 729       _in_dump_cnt(0)
 730 #endif
 731 {
 732   C = this;
 733   CompileWrapper cw(this);
 734 
 735   TraceTime t1("Total compilation time", &_t_totalCompilation, CITime, CITimeVerbose);
 736   TraceTime t2(nullptr, &_t_methodCompilation, CITime, false);
 737 
 738 #if defined(SUPPORT_ASSEMBLY) || defined(SUPPORT_ABSTRACT_ASSEMBLY)
 739   bool print_opto_assembly = directive->PrintOptoAssemblyOption;
 740   // We can always print a disassembly, either abstract (hex dump) or
 741   // with the help of a suitable hsdis library. Thus, we should not
 742   // couple print_assembly and print_opto_assembly controls.
 743   // But: always print opto and regular assembly on compile command 'print'.
 744   bool print_assembly = directive->PrintAssemblyOption;
 745   set_print_assembly(print_opto_assembly || print_assembly);
 746 #else
 747   set_print_assembly(false); // must initialize.
 748 #endif
 749 
 750 #ifndef PRODUCT
 751   set_parsed_irreducible_loop(false);
 752 #endif
 753 
 754   if (directive->ReplayInlineOption) {
 755     _replay_inline_data = ciReplay::load_inline_data(method(), entry_bci(), ci_env->comp_level());
 756   }
 757   set_print_inlining(directive->PrintInliningOption || PrintOptoInlining);
 758   set_print_intrinsics(directive->PrintIntrinsicsOption);
 759   set_has_irreducible_loop(true); // conservative until build_loop_tree() reset it
 760 
 761   if (ProfileTraps) {
 762     // Make sure the method being compiled gets its own MDO,
 763     // so we can at least track the decompile_count().
 764     method()->ensure_method_data();
 765   }
 766 
 767   if (StressLCM || StressGCM || StressIGVN || StressCCP ||
 768       StressIncrementalInlining || StressMacroExpansion ||
 769       StressMacroElimination || StressUnstableIfTraps ||
 770       StressBailout || StressLoopPeeling || StressCountedLoop) {
 771     initialize_stress_seed(directive);
 772   }
 773 
 774   Init(/*do_aliasing=*/ true);
 775 
 776   print_compile_messages();
 777 
 778   _ilt = InlineTree::build_inline_tree_root();
 779 
 780   // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
 781   assert(num_alias_types() >= AliasIdxRaw, "");
 782 
 783 #define MINIMUM_NODE_HASH  1023
 784 
 785   // GVN that will be run immediately on new nodes
 786   uint estimated_size = method()->code_size()*4+64;
 787   estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
 788   _igvn_worklist = new (comp_arena()) Unique_Node_List(comp_arena());
 789   _types = new (comp_arena()) Type_Array(comp_arena());
 790   _node_hash = new (comp_arena()) NodeHash(comp_arena(), estimated_size);
 791   PhaseGVN gvn;
 792   set_initial_gvn(&gvn);
 793 
 794   { // Scope for timing the parser
 795     TracePhase tp(_t_parser);
 796 
 797     // Put top into the hash table ASAP.
 798     initial_gvn()->transform(top());
 799 
 800     // Set up tf(), start(), and find a CallGenerator.
 801     CallGenerator* cg = nullptr;
 802     if (is_osr_compilation()) {
 803       init_tf(TypeFunc::make(method(), /* is_osr_compilation = */ true));
 804       StartNode* s = new StartOSRNode(root(), tf()->domain_sig());
 805       initial_gvn()->set_type_bottom(s);
 806       verify_start(s);
 807       cg = CallGenerator::for_osr(method(), entry_bci());
 808     } else {
 809       // Normal case.
 810       init_tf(TypeFunc::make(method()));
 811       StartNode* s = new StartNode(root(), tf()->domain_cc());
 812       initial_gvn()->set_type_bottom(s);
 813       verify_start(s);
 814       float past_uses = method()->interpreter_invocation_count();
 815       float expected_uses = past_uses;
 816       cg = CallGenerator::for_inline(method(), expected_uses);
 817     }
 818     if (failing())  return;
 819     if (cg == nullptr) {
 820       const char* reason = InlineTree::check_can_parse(method());
 821       assert(reason != nullptr, "expect reason for parse failure");
 822       stringStream ss;
 823       ss.print("cannot parse method: %s", reason);
 824       record_method_not_compilable(ss.as_string());
 825       return;
 826     }
 827 
 828     gvn.set_type(root(), root()->bottom_type());
 829 
 830     JVMState* jvms = build_start_state(start(), tf());
 831     if ((jvms = cg->generate(jvms)) == nullptr) {
 832       assert(failure_reason() != nullptr, "expect reason for parse failure");
 833       stringStream ss;
 834       ss.print("method parse failed: %s", failure_reason());
 835       record_method_not_compilable(ss.as_string() DEBUG_ONLY(COMMA true));
 836       return;
 837     }
 838     GraphKit kit(jvms);
 839 
 840     if (!kit.stopped()) {
 841       // Accept return values, and transfer control we know not where.
 842       // This is done by a special, unique ReturnNode bound to root.
 843       return_values(kit.jvms());
 844     }
 845 
 846     if (kit.has_exceptions()) {
 847       // Any exceptions that escape from this call must be rethrown
 848       // to whatever caller is dynamically above us on the stack.
 849       // This is done by a special, unique RethrowNode bound to root.
 850       rethrow_exceptions(kit.transfer_exceptions_into_jvms());
 851     }
 852 
 853     assert(IncrementalInline || (_late_inlines.length() == 0 && !has_mh_late_inlines()), "incremental inlining is off");
 854 
 855     if (_late_inlines.length() == 0 && !has_mh_late_inlines() && !failing() && has_stringbuilder()) {
 856       inline_string_calls(true);
 857     }
 858 
 859     if (failing())  return;
 860 
 861     // Remove clutter produced by parsing.
 862     if (!failing()) {
 863       ResourceMark rm;
 864       PhaseRemoveUseless pru(initial_gvn(), *igvn_worklist());
 865     }
 866   }
 867 
 868   // Note:  Large methods are capped off in do_one_bytecode().
 869   if (failing())  return;
 870 
 871   // After parsing, node notes are no longer automagic.
 872   // They must be propagated by register_new_node_with_optimizer(),
 873   // clone(), or the like.
 874   set_default_node_notes(nullptr);
 875 
 876 #ifndef PRODUCT
 877   if (should_print_igv(1)) {
 878     _igv_printer->print_inlining();
 879   }
 880 #endif
 881 
 882   if (failing())  return;
 883   NOT_PRODUCT( verify_graph_edges(); )
 884 
 885   // Now optimize
 886   Optimize();
 887   if (failing())  return;
 888   NOT_PRODUCT( verify_graph_edges(); )
 889 
 890 #ifndef PRODUCT
 891   if (should_print_ideal()) {
 892     print_ideal_ir("PrintIdeal");
 893   }
 894 #endif
 895 
 896 #ifdef ASSERT
 897   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 898   bs->verify_gc_barriers(this, BarrierSetC2::BeforeCodeGen);
 899 #endif
 900 
 901   // Dump compilation data to replay it.
 902   if (directive->DumpReplayOption) {
 903     env()->dump_replay_data(_compile_id);
 904   }
 905   if (directive->DumpInlineOption && (ilt() != nullptr)) {
 906     env()->dump_inline_data(_compile_id);
 907   }
 908 
 909   // Now that we know the size of all the monitors we can add a fixed slot
 910   // for the original deopt pc.
 911   int next_slot = fixed_slots() + (sizeof(address) / VMRegImpl::stack_slot_size);
 912   if (needs_stack_repair()) {
 913     // One extra slot for the special stack increment value
 914     next_slot += 2;
 915   }
 916   // TODO 8284443 Only reserve extra slot if needed
 917   if (InlineTypeReturnedAsFields) {
 918     // One extra slot to hold the null marker for a nullable
 919     // inline type return if we run out of registers.
 920     next_slot += 2;
 921   }
 922   set_fixed_slots(next_slot);
 923 
 924   // Compute when to use implicit null checks. Used by matching trap based
 925   // nodes and NullCheck optimization.
 926   set_allowed_deopt_reasons();
 927 
 928   // Now generate code
 929   Code_Gen();
 930 }
 931 
 932 //------------------------------Compile----------------------------------------
 933 // Compile a runtime stub
 934 Compile::Compile(ciEnv* ci_env,
 935                  TypeFunc_generator generator,
 936                  address stub_function,
 937                  const char* stub_name,
 938                  StubId stub_id,
 939                  int is_fancy_jump,
 940                  bool pass_tls,
 941                  bool return_pc,
 942                  DirectiveSet* directive)
 943     : Phase(Compiler),
 944       _compile_id(0),
 945       _options(Options::for_runtime_stub()),
 946       _method(nullptr),
 947       _entry_bci(InvocationEntryBci),
 948       _stub_function(stub_function),
 949       _stub_name(stub_name),
 950       _stub_id(stub_id),
 951       _stub_entry_point(nullptr),
 952       _max_node_limit(MaxNodeLimit),
 953       _post_loop_opts_phase(false),
 954       _merge_stores_phase(false),
 955       _allow_macro_nodes(true),
 956       _inlining_progress(false),
 957       _inlining_incrementally(false),
 958       _has_reserved_stack_access(false),
 959       _has_circular_inline_type(false),
 960 #ifndef PRODUCT
 961       _igv_idx(0),
 962       _trace_opto_output(directive->TraceOptoOutputOption),
 963 #endif
 964       _clinit_barrier_on_entry(false),
 965       _stress_seed(0),
 966       _comp_arena(mtCompiler, Arena::Tag::tag_comp),
 967       _barrier_set_state(BarrierSet::barrier_set()->barrier_set_c2()->create_barrier_state(comp_arena())),
 968       _env(ci_env),
 969       _directive(directive),
 970       _log(ci_env->log()),
 971       _first_failure_details(nullptr),
 972       _for_post_loop_igvn(comp_arena(), 8, 0, nullptr),
 973       _for_merge_stores_igvn(comp_arena(), 8, 0, nullptr),
 974       _congraph(nullptr),
 975       NOT_PRODUCT(_igv_printer(nullptr) COMMA)
 976       _unique(0),
 977       _dead_node_count(0),
 978       _dead_node_list(comp_arena()),
 979       _node_arena_one(mtCompiler, Arena::Tag::tag_node),
 980       _node_arena_two(mtCompiler, Arena::Tag::tag_node),
 981       _node_arena(&_node_arena_one),
 982       _mach_constant_base_node(nullptr),
 983       _Compile_types(mtCompiler, Arena::Tag::tag_type),
 984       _initial_gvn(nullptr),
 985       _igvn_worklist(nullptr),
 986       _types(nullptr),
 987       _node_hash(nullptr),
 988       _has_mh_late_inlines(false),
 989       _oom(false),
 990       _replay_inline_data(nullptr),
 991       _inline_printer(this),
 992       _java_calls(0),
 993       _inner_loops(0),
 994       _FIRST_STACK_mask(comp_arena()),
 995       _interpreter_frame_size(0),
 996       _regmask_arena(mtCompiler, Arena::Tag::tag_regmask),
 997       _output(nullptr),
 998 #ifndef PRODUCT
 999       _in_dump_cnt(0),
1000 #endif
1001       _allowed_reasons(0) {
1002   C = this;
1003 
1004   // try to reuse an existing stub
1005   {
1006     BlobId blob_id = StubInfo::blob(_stub_id);
1007     CodeBlob* blob = AOTCodeCache::load_code_blob(AOTCodeEntry::C2Blob, blob_id);
1008     if (blob != nullptr) {
1009       RuntimeStub* rs = blob->as_runtime_stub();
1010       _stub_entry_point = rs->entry_point();
1011       return;
1012     }
1013   }
1014 
1015   TraceTime t1(nullptr, &_t_totalCompilation, CITime, false);
1016   TraceTime t2(nullptr, &_t_stubCompilation, CITime, false);
1017 
1018 #ifndef PRODUCT
1019   set_print_assembly(PrintFrameConverterAssembly);
1020   set_parsed_irreducible_loop(false);
1021 #else
1022   set_print_assembly(false); // Must initialize.
1023 #endif
1024   set_has_irreducible_loop(false); // no loops
1025 
1026   CompileWrapper cw(this);
1027   Init(/*do_aliasing=*/ false);
1028   init_tf((*generator)());
1029 
1030   _igvn_worklist = new (comp_arena()) Unique_Node_List(comp_arena());
1031   _types = new (comp_arena()) Type_Array(comp_arena());
1032   _node_hash = new (comp_arena()) NodeHash(comp_arena(), 255);
1033 
1034   if (StressLCM || StressGCM || StressBailout) {
1035     initialize_stress_seed(directive);
1036   }
1037 
1038   {
1039     PhaseGVN gvn;
1040     set_initial_gvn(&gvn);    // not significant, but GraphKit guys use it pervasively
1041     gvn.transform(top());
1042 
1043     GraphKit kit;
1044     kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
1045   }
1046 
1047   NOT_PRODUCT( verify_graph_edges(); )
1048 
1049   Code_Gen();
1050 }
1051 
1052 Compile::~Compile() {
1053   delete _first_failure_details;
1054 };
1055 
1056 //------------------------------Init-------------------------------------------
1057 // Prepare for a single compilation
1058 void Compile::Init(bool aliasing) {
1059   _do_aliasing = aliasing;
1060   _unique  = 0;
1061   _regalloc = nullptr;
1062 
1063   _tf      = nullptr;  // filled in later
1064   _top     = nullptr;  // cached later
1065   _matcher = nullptr;  // filled in later
1066   _cfg     = nullptr;  // filled in later
1067 
1068   _node_note_array = nullptr;
1069   _default_node_notes = nullptr;
1070   DEBUG_ONLY( _modified_nodes = nullptr; ) // Used in Optimize()
1071 
1072   _immutable_memory = nullptr; // filled in at first inquiry
1073 
1074 #ifdef ASSERT
1075   _phase_optimize_finished = false;
1076   _phase_verify_ideal_loop = false;
1077   _exception_backedge = false;
1078   _type_verify = nullptr;
1079 #endif
1080 
1081   // Globally visible Nodes
1082   // First set TOP to null to give safe behavior during creation of RootNode
1083   set_cached_top_node(nullptr);
1084   set_root(new RootNode());
1085   // Now that you have a Root to point to, create the real TOP
1086   set_cached_top_node( new ConNode(Type::TOP) );
1087   set_recent_alloc(nullptr, nullptr);
1088 
1089   // Create Debug Information Recorder to record scopes, oopmaps, etc.
1090   env()->set_oop_recorder(new OopRecorder(env()->arena()));
1091   env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
1092   env()->set_dependencies(new Dependencies(env()));
1093 
1094   _fixed_slots = 0;
1095   set_has_split_ifs(false);
1096   set_has_loops(false); // first approximation
1097   set_has_stringbuilder(false);
1098   set_has_boxed_value(false);
1099   _trap_can_recompile = false;  // no traps emitted yet
1100   _major_progress = true; // start out assuming good things will happen
1101   set_has_unsafe_access(false);
1102   set_max_vector_size(0);
1103   set_clear_upper_avx(false);  //false as default for clear upper bits of ymm registers
1104   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
1105   set_decompile_count(0);
1106 
1107 #ifndef PRODUCT
1108   _phase_counter = 0;
1109   Copy::zero_to_bytes(_igv_phase_iter, sizeof(_igv_phase_iter));
1110 #endif
1111 
1112   set_do_freq_based_layout(_directive->BlockLayoutByFrequencyOption);
1113   _loop_opts_cnt = LoopOptsCount;
1114   _has_flat_accesses = false;
1115   _flat_accesses_share_alias = true;
1116   _scalarize_in_safepoints = false;
1117 
1118   set_do_inlining(Inline);
1119   set_max_inline_size(MaxInlineSize);
1120   set_freq_inline_size(FreqInlineSize);
1121   set_do_scheduling(OptoScheduling);
1122 
1123   set_do_vector_loop(false);
1124   set_has_monitors(false);
1125   set_has_scoped_access(false);
1126 
1127   if (AllowVectorizeOnDemand) {
1128     if (has_method() && _directive->VectorizeOption) {
1129       set_do_vector_loop(true);
1130       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());})
1131     } else if (has_method() && method()->name() != nullptr &&
1132                method()->intrinsic_id() == vmIntrinsics::_forEachRemaining) {
1133       set_do_vector_loop(true);
1134     }
1135   }
1136   set_use_cmove(UseCMoveUnconditionally /* || do_vector_loop()*/); //TODO: consider do_vector_loop() mandate use_cmove unconditionally
1137   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());})
1138 
1139   _max_node_limit = _directive->MaxNodeLimitOption;
1140 
1141   if (VM_Version::supports_fast_class_init_checks() && has_method() && !is_osr_compilation() && method()->needs_clinit_barrier()) {
1142     set_clinit_barrier_on_entry(true);
1143   }
1144   if (debug_info()->recording_non_safepoints()) {
1145     set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
1146                         (comp_arena(), 8, 0, nullptr));
1147     set_default_node_notes(Node_Notes::make(this));
1148   }
1149 
1150   const int grow_ats = 16;
1151   _max_alias_types = grow_ats;
1152   _alias_types   = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
1153   AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType,  grow_ats);
1154   Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
1155   {
1156     for (int i = 0; i < grow_ats; i++)  _alias_types[i] = &ats[i];
1157   }
1158   // Initialize the first few types.
1159   _alias_types[AliasIdxTop]->Init(AliasIdxTop, nullptr);
1160   _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
1161   _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
1162   _num_alias_types = AliasIdxRaw+1;
1163   // Zero out the alias type cache.
1164   Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
1165   // A null adr_type hits in the cache right away.  Preload the right answer.
1166   probe_alias_cache(nullptr)->_index = AliasIdxTop;
1167 }
1168 
1169 #ifdef ASSERT
1170 // Verify that the current StartNode is valid.
1171 void Compile::verify_start(StartNode* s) const {
1172   assert(failing_internal() || s == start(), "should be StartNode");
1173 }
1174 #endif
1175 
1176 /**
1177  * Return the 'StartNode'. We must not have a pending failure, since the ideal graph
1178  * can be in an inconsistent state, i.e., we can get segmentation faults when traversing
1179  * the ideal graph.
1180  */
1181 StartNode* Compile::start() const {
1182   assert (!failing_internal() || C->failure_is_artificial(), "Must not have pending failure. Reason is: %s", failure_reason());
1183   for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
1184     Node* start = root()->fast_out(i);
1185     if (start->is_Start()) {
1186       return start->as_Start();
1187     }
1188   }
1189   fatal("Did not find Start node!");
1190   return nullptr;
1191 }
1192 
1193 //-------------------------------immutable_memory-------------------------------------
1194 // Access immutable memory
1195 Node* Compile::immutable_memory() {
1196   if (_immutable_memory != nullptr) {
1197     return _immutable_memory;
1198   }
1199   StartNode* s = start();
1200   for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
1201     Node *p = s->fast_out(i);
1202     if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
1203       _immutable_memory = p;
1204       return _immutable_memory;
1205     }
1206   }
1207   ShouldNotReachHere();
1208   return nullptr;
1209 }
1210 
1211 //----------------------set_cached_top_node------------------------------------
1212 // Install the cached top node, and make sure Node::is_top works correctly.
1213 void Compile::set_cached_top_node(Node* tn) {
1214   if (tn != nullptr)  verify_top(tn);
1215   Node* old_top = _top;
1216   _top = tn;
1217   // Calling Node::setup_is_top allows the nodes the chance to adjust
1218   // their _out arrays.
1219   if (_top != nullptr)     _top->setup_is_top();
1220   if (old_top != nullptr)  old_top->setup_is_top();
1221   assert(_top == nullptr || top()->is_top(), "");
1222 }
1223 
1224 #ifdef ASSERT
1225 uint Compile::count_live_nodes_by_graph_walk() {
1226   Unique_Node_List useful(comp_arena());
1227   // Get useful node list by walking the graph.
1228   identify_useful_nodes(useful);
1229   return useful.size();
1230 }
1231 
1232 void Compile::print_missing_nodes() {
1233 
1234   // Return if CompileLog is null and PrintIdealNodeCount is false.
1235   if ((_log == nullptr) && (! PrintIdealNodeCount)) {
1236     return;
1237   }
1238 
1239   // This is an expensive function. It is executed only when the user
1240   // specifies VerifyIdealNodeCount option or otherwise knows the
1241   // additional work that needs to be done to identify reachable nodes
1242   // by walking the flow graph and find the missing ones using
1243   // _dead_node_list.
1244 
1245   Unique_Node_List useful(comp_arena());
1246   // Get useful node list by walking the graph.
1247   identify_useful_nodes(useful);
1248 
1249   uint l_nodes = C->live_nodes();
1250   uint l_nodes_by_walk = useful.size();
1251 
1252   if (l_nodes != l_nodes_by_walk) {
1253     if (_log != nullptr) {
1254       _log->begin_head("mismatched_nodes count='%d'", abs((int) (l_nodes - l_nodes_by_walk)));
1255       _log->stamp();
1256       _log->end_head();
1257     }
1258     VectorSet& useful_member_set = useful.member_set();
1259     int last_idx = l_nodes_by_walk;
1260     for (int i = 0; i < last_idx; i++) {
1261       if (useful_member_set.test(i)) {
1262         if (_dead_node_list.test(i)) {
1263           if (_log != nullptr) {
1264             _log->elem("mismatched_node_info node_idx='%d' type='both live and dead'", i);
1265           }
1266           if (PrintIdealNodeCount) {
1267             // Print the log message to tty
1268               tty->print_cr("mismatched_node idx='%d' both live and dead'", i);
1269               useful.at(i)->dump();
1270           }
1271         }
1272       }
1273       else if (! _dead_node_list.test(i)) {
1274         if (_log != nullptr) {
1275           _log->elem("mismatched_node_info node_idx='%d' type='neither live nor dead'", i);
1276         }
1277         if (PrintIdealNodeCount) {
1278           // Print the log message to tty
1279           tty->print_cr("mismatched_node idx='%d' type='neither live nor dead'", i);
1280         }
1281       }
1282     }
1283     if (_log != nullptr) {
1284       _log->tail("mismatched_nodes");
1285     }
1286   }
1287 }
1288 void Compile::record_modified_node(Node* n) {
1289   if (_modified_nodes != nullptr && !_inlining_incrementally && !n->is_Con()) {
1290     _modified_nodes->push(n);
1291   }
1292 }
1293 
1294 void Compile::remove_modified_node(Node* n) {
1295   if (_modified_nodes != nullptr) {
1296     _modified_nodes->remove(n);
1297   }
1298 }
1299 #endif
1300 
1301 #ifndef PRODUCT
1302 void Compile::verify_top(Node* tn) const {
1303   if (tn != nullptr) {
1304     assert(tn->is_Con(), "top node must be a constant");
1305     assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
1306     assert(tn->in(0) != nullptr, "must have live top node");
1307   }
1308 }
1309 #endif
1310 
1311 
1312 ///-------------------Managing Per-Node Debug & Profile Info-------------------
1313 
1314 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
1315   guarantee(arr != nullptr, "");
1316   int num_blocks = arr->length();
1317   if (grow_by < num_blocks)  grow_by = num_blocks;
1318   int num_notes = grow_by * _node_notes_block_size;
1319   Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
1320   Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
1321   while (num_notes > 0) {
1322     arr->append(notes);
1323     notes     += _node_notes_block_size;
1324     num_notes -= _node_notes_block_size;
1325   }
1326   assert(num_notes == 0, "exact multiple, please");
1327 }
1328 
1329 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
1330   if (source == nullptr || dest == nullptr)  return false;
1331 
1332   if (dest->is_Con())
1333     return false;               // Do not push debug info onto constants.
1334 
1335 #ifdef ASSERT
1336   // Leave a bread crumb trail pointing to the original node:
1337   if (dest != nullptr && dest != source && dest->debug_orig() == nullptr) {
1338     dest->set_debug_orig(source);
1339   }
1340 #endif
1341 
1342   if (node_note_array() == nullptr)
1343     return false;               // Not collecting any notes now.
1344 
1345   // This is a copy onto a pre-existing node, which may already have notes.
1346   // If both nodes have notes, do not overwrite any pre-existing notes.
1347   Node_Notes* source_notes = node_notes_at(source->_idx);
1348   if (source_notes == nullptr || source_notes->is_clear())  return false;
1349   Node_Notes* dest_notes   = node_notes_at(dest->_idx);
1350   if (dest_notes == nullptr || dest_notes->is_clear()) {
1351     return set_node_notes_at(dest->_idx, source_notes);
1352   }
1353 
1354   Node_Notes merged_notes = (*source_notes);
1355   // The order of operations here ensures that dest notes will win...
1356   merged_notes.update_from(dest_notes);
1357   return set_node_notes_at(dest->_idx, &merged_notes);
1358 }
1359 
1360 
1361 //--------------------------allow_range_check_smearing-------------------------
1362 // Gating condition for coalescing similar range checks.
1363 // Sometimes we try 'speculatively' replacing a series of a range checks by a
1364 // single covering check that is at least as strong as any of them.
1365 // If the optimization succeeds, the simplified (strengthened) range check
1366 // will always succeed.  If it fails, we will deopt, and then give up
1367 // on the optimization.
1368 bool Compile::allow_range_check_smearing() const {
1369   // If this method has already thrown a range-check,
1370   // assume it was because we already tried range smearing
1371   // and it failed.
1372   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
1373   return !already_trapped;
1374 }
1375 
1376 
1377 //------------------------------flatten_alias_type-----------------------------
1378 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
1379   assert(do_aliasing(), "Aliasing should be enabled");
1380   int offset = tj->offset();
1381   TypePtr::PTR ptr = tj->ptr();
1382 
1383   // Known instance (scalarizable allocation) alias only with itself.
1384   bool is_known_inst = tj->isa_oopptr() != nullptr &&
1385                        tj->is_oopptr()->is_known_instance();
1386 
1387   // Process weird unsafe references.
1388   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
1389     assert(InlineUnsafeOps || StressReflectiveCode, "indeterminate pointers come only from unsafe ops");
1390     assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
1391     tj = TypeOopPtr::BOTTOM;
1392     ptr = tj->ptr();
1393     offset = tj->offset();
1394   }
1395 
1396   // Array pointers need some flattening
1397   const TypeAryPtr* ta = tj->isa_aryptr();
1398   if( ta && is_known_inst ) {
1399     if ( offset != Type::OffsetBot &&
1400          offset > arrayOopDesc::length_offset_in_bytes() ) {
1401       offset = Type::OffsetBot; // Flatten constant access into array body only
1402       tj = ta = ta->
1403               remove_speculative()->
1404               cast_to_ptr_type(ptr)->
1405               with_offset(offset);
1406     }
1407   } else if (ta != nullptr) {
1408     // Common slices
1409     if (offset == arrayOopDesc::length_offset_in_bytes()) {
1410       return TypeAryPtr::RANGE;
1411     } else if (offset == oopDesc::klass_offset_in_bytes()) {
1412       return TypeInstPtr::KLASS;
1413     } else if (offset == oopDesc::mark_offset_in_bytes()) {
1414       return TypeInstPtr::MARK;
1415     }
1416 
1417     // Remove size and stability
1418     const TypeAry* normalized_ary = TypeAry::make(ta->elem(), TypeInt::POS, false, ta->is_flat(), ta->is_not_flat(), ta->is_not_null_free(), ta->is_atomic());
1419     // Remove ptr, const_oop, and offset
1420     if (ta->elem() == Type::BOTTOM) {
1421       // Bottom array (meet of int[] and byte[] for example), accesses to it will be done with
1422       // Unsafe. This should alias with all arrays. For now just leave it as it is (this is
1423       // incorrect, see JDK-8331133).
1424       tj = ta = TypeAryPtr::make(TypePtr::BotPTR, nullptr, normalized_ary, nullptr, false, Type::Offset::bottom);
1425     } else if (ta->elem()->make_oopptr() != nullptr) {
1426       // Object arrays, keep field_offset
1427       tj = ta = TypeAryPtr::make(TypePtr::BotPTR, nullptr, normalized_ary, nullptr, ta->klass_is_exact(), Type::Offset::bottom, Type::Offset(ta->field_offset()));
1428     } else {
1429       // Primitive arrays
1430       tj = ta = TypeAryPtr::make(TypePtr::BotPTR, nullptr, normalized_ary, ta->exact_klass(), true, Type::Offset::bottom);
1431     }
1432 
1433     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
1434     // cannot be distinguished by bytecode alone.
1435     if (ta->elem() == TypeInt::BOOL) {
1436       tj = ta = TypeAryPtr::BYTES;
1437     }
1438 
1439     // All arrays of references share the same slice
1440     if (!ta->is_flat() && ta->elem()->make_oopptr() != nullptr) {
1441       const TypeAry* tary = TypeAry::make(TypeInstPtr::BOTTOM, TypeInt::POS, false, false, true, true, true);
1442       tj = ta = TypeAryPtr::make(TypePtr::BotPTR, nullptr, tary, nullptr, false, Type::Offset::bottom);
1443     }
1444 
1445     if (ta->is_flat()) {
1446       if (_flat_accesses_share_alias) {
1447         // Initially all flattened array accesses share a single slice
1448         tj = ta = TypeAryPtr::INLINES;
1449       } else {
1450         // Flat accesses are always exact
1451         tj = ta = ta->cast_to_exactness(true);
1452       }
1453     }
1454   }
1455 
1456   // Oop pointers need some flattening
1457   const TypeInstPtr *to = tj->isa_instptr();
1458   if (to && to != TypeOopPtr::BOTTOM) {
1459     ciInstanceKlass* ik = to->instance_klass();
1460     tj = to = to->cast_to_maybe_flat_in_array(); // flatten to maybe flat in array
1461     if( ptr == TypePtr::Constant ) {
1462       if (ik != ciEnv::current()->Class_klass() ||
1463           offset < ik->layout_helper_size_in_bytes()) {
1464         // No constant oop pointers (such as Strings); they alias with
1465         // unknown strings.
1466         assert(!is_known_inst, "not scalarizable allocation");
1467         tj = to = to->
1468                 cast_to_instance_id(TypeOopPtr::InstanceBot)->
1469                 remove_speculative()->
1470                 cast_to_ptr_type(TypePtr::BotPTR)->
1471                 cast_to_exactness(false);
1472       }
1473     } else if( is_known_inst ) {
1474       tj = to; // Keep NotNull and klass_is_exact for instance type
1475     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
1476       // During the 2nd round of IterGVN, NotNull castings are removed.
1477       // Make sure the Bottom and NotNull variants alias the same.
1478       // Also, make sure exact and non-exact variants alias the same.
1479       tj = to = to->
1480               remove_speculative()->
1481               cast_to_instance_id(TypeOopPtr::InstanceBot)->
1482               cast_to_ptr_type(TypePtr::BotPTR)->
1483               cast_to_exactness(false);
1484     }
1485     if (to->speculative() != nullptr) {
1486       tj = to = to->remove_speculative();
1487     }
1488     // Canonicalize the holder of this field
1489     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
1490       // First handle header references such as a LoadKlassNode, even if the
1491       // object's klass is unloaded at compile time (4965979).
1492       if (!is_known_inst) { // Do it only for non-instance types
1493         tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, nullptr, Type::Offset(offset));
1494       }
1495     } else if (offset < 0 || offset >= ik->layout_helper_size_in_bytes()) {
1496       // Static fields are in the space above the normal instance
1497       // fields in the java.lang.Class instance.
1498       if (ik != ciEnv::current()->Class_klass()) {
1499         to = nullptr;
1500         tj = TypeOopPtr::BOTTOM;
1501         offset = tj->offset();
1502       }
1503     } else {
1504       ciInstanceKlass *canonical_holder = ik->get_canonical_holder(offset);
1505       assert(offset < canonical_holder->layout_helper_size_in_bytes(), "");
1506       assert(tj->offset() == offset, "no change to offset expected");
1507       bool xk = to->klass_is_exact();
1508       int instance_id = to->instance_id();
1509 
1510       // If the input type's class is the holder: if exact, the type only includes interfaces implemented by the holder
1511       // but if not exact, it may include extra interfaces: build new type from the holder class to make sure only
1512       // its interfaces are included.
1513       if (xk && ik->equals(canonical_holder)) {
1514         assert(tj == TypeInstPtr::make(to->ptr(), canonical_holder, is_known_inst, nullptr, Type::Offset(offset), instance_id,
1515                                        TypePtr::MaybeFlat), "exact type should be canonical type");
1516       } else {
1517         assert(xk || !is_known_inst, "Known instance should be exact type");
1518         tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, is_known_inst, nullptr, Type::Offset(offset), instance_id,
1519                                     TypePtr::MaybeFlat);
1520       }
1521     }
1522   }
1523 
1524   // Klass pointers to object array klasses need some flattening
1525   const TypeKlassPtr *tk = tj->isa_klassptr();
1526   if( tk ) {
1527     // If we are referencing a field within a Klass, we need
1528     // to assume the worst case of an Object.  Both exact and
1529     // inexact types must flatten to the same alias class so
1530     // use NotNull as the PTR.
1531     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
1532       tj = tk = TypeInstKlassPtr::make(TypePtr::NotNull,
1533                                        env()->Object_klass(),
1534                                        Type::Offset(offset),
1535                                        TypePtr::MaybeFlat);
1536     }
1537 
1538     if (tk->isa_aryklassptr() && tk->is_aryklassptr()->elem()->isa_klassptr()) {
1539       ciKlass* k = ciObjArrayKlass::make(env()->Object_klass());
1540       if (!k || !k->is_loaded()) {                  // Only fails for some -Xcomp runs
1541         tj = tk = TypeInstKlassPtr::make(TypePtr::NotNull, env()->Object_klass(), Type::Offset(offset), TypePtr::MaybeFlat);
1542       } else {
1543         tj = tk = TypeAryKlassPtr::make(TypePtr::NotNull, tk->is_aryklassptr()->elem(), k, Type::Offset(offset), tk->is_not_flat(), tk->is_not_null_free(), tk->is_flat(), tk->is_null_free(), tk->is_atomic(), tk->is_aryklassptr()->is_refined_type());
1544       }
1545     }
1546     // Check for precise loads from the primary supertype array and force them
1547     // to the supertype cache alias index.  Check for generic array loads from
1548     // the primary supertype array and also force them to the supertype cache
1549     // alias index.  Since the same load can reach both, we need to merge
1550     // these 2 disparate memories into the same alias class.  Since the
1551     // primary supertype array is read-only, there's no chance of confusion
1552     // where we bypass an array load and an array store.
1553     int primary_supers_offset = in_bytes(Klass::primary_supers_offset());
1554     if (offset == Type::OffsetBot ||
1555         (offset >= primary_supers_offset &&
1556          offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
1557         offset == (int)in_bytes(Klass::secondary_super_cache_offset())) {
1558       offset = in_bytes(Klass::secondary_super_cache_offset());
1559       tj = tk = tk->with_offset(offset);
1560     }
1561   }
1562 
1563   // Flatten all Raw pointers together.
1564   if (tj->base() == Type::RawPtr)
1565     tj = TypeRawPtr::BOTTOM;
1566 
1567   if (tj->base() == Type::AnyPtr)
1568     tj = TypePtr::BOTTOM;      // An error, which the caller must check for.
1569 
1570   offset = tj->offset();
1571   assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
1572 
1573   assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
1574           (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
1575           (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
1576           (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
1577           (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1578           (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1579           (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr),
1580           "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
1581   assert( tj->ptr() != TypePtr::TopPTR &&
1582           tj->ptr() != TypePtr::AnyNull &&
1583           tj->ptr() != TypePtr::Null, "No imprecise addresses" );
1584 //    assert( tj->ptr() != TypePtr::Constant ||
1585 //            tj->base() == Type::RawPtr ||
1586 //            tj->base() == Type::KlassPtr, "No constant oop addresses" );
1587 
1588   return tj;
1589 }
1590 
1591 void Compile::AliasType::Init(int i, const TypePtr* at) {
1592   assert(AliasIdxTop <= i && i < Compile::current()->_max_alias_types, "Invalid alias index");
1593   _index = i;
1594   _adr_type = at;
1595   _field = nullptr;
1596   _element = nullptr;
1597   _is_rewritable = true; // default
1598   const TypeOopPtr *atoop = (at != nullptr) ? at->isa_oopptr() : nullptr;
1599   if (atoop != nullptr && atoop->is_known_instance()) {
1600     const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
1601     _general_index = Compile::current()->get_alias_index(gt);
1602   } else {
1603     _general_index = 0;
1604   }
1605 }
1606 
1607 BasicType Compile::AliasType::basic_type() const {
1608   if (element() != nullptr) {
1609     const Type* element = adr_type()->is_aryptr()->elem();
1610     return element->isa_narrowoop() ? T_OBJECT : element->array_element_basic_type();
1611   } if (field() != nullptr) {
1612     return field()->layout_type();
1613   } else {
1614     return T_ILLEGAL; // unknown
1615   }
1616 }
1617 
1618 //---------------------------------print_on------------------------------------
1619 #ifndef PRODUCT
1620 void Compile::AliasType::print_on(outputStream* st) {
1621   if (index() < 10)
1622         st->print("@ <%d> ", index());
1623   else  st->print("@ <%d>",  index());
1624   st->print(is_rewritable() ? "   " : " RO");
1625   int offset = adr_type()->offset();
1626   if (offset == Type::OffsetBot)
1627         st->print(" +any");
1628   else  st->print(" +%-3d", offset);
1629   st->print(" in ");
1630   adr_type()->dump_on(st);
1631   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
1632   if (field() != nullptr && tjp) {
1633     if (tjp->is_instptr()->instance_klass()  != field()->holder() ||
1634         tjp->offset() != field()->offset_in_bytes()) {
1635       st->print(" != ");
1636       field()->print();
1637       st->print(" ***");
1638     }
1639   }
1640 }
1641 
1642 void print_alias_types() {
1643   Compile* C = Compile::current();
1644   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
1645   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
1646     C->alias_type(idx)->print_on(tty);
1647     tty->cr();
1648   }
1649 }
1650 #endif
1651 
1652 
1653 //----------------------------probe_alias_cache--------------------------------
1654 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
1655   intptr_t key = (intptr_t) adr_type;
1656   key ^= key >> logAliasCacheSize;
1657   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
1658 }
1659 
1660 
1661 //-----------------------------grow_alias_types--------------------------------
1662 void Compile::grow_alias_types() {
1663   const int old_ats  = _max_alias_types; // how many before?
1664   const int new_ats  = old_ats;          // how many more?
1665   const int grow_ats = old_ats+new_ats;  // how many now?
1666   _max_alias_types = grow_ats;
1667   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
1668   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
1669   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
1670   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
1671 }
1672 
1673 
1674 //--------------------------------find_alias_type------------------------------
1675 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field, bool uncached) {
1676   if (!do_aliasing()) {
1677     return alias_type(AliasIdxBot);
1678   }
1679 
1680   AliasCacheEntry* ace = nullptr;
1681   if (!uncached) {
1682     ace = probe_alias_cache(adr_type);
1683     if (ace->_adr_type == adr_type) {
1684       return alias_type(ace->_index);
1685     }
1686   }
1687 
1688   // Handle special cases.
1689   if (adr_type == nullptr)          return alias_type(AliasIdxTop);
1690   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
1691 
1692   // Do it the slow way.
1693   const TypePtr* flat = flatten_alias_type(adr_type);
1694 
1695 #ifdef ASSERT
1696   {
1697     ResourceMark rm;
1698     assert(flat == flatten_alias_type(flat), "not idempotent: adr_type = %s; flat = %s => %s",
1699            Type::str(adr_type), Type::str(flat), Type::str(flatten_alias_type(flat)));
1700     assert(flat != TypePtr::BOTTOM, "cannot alias-analyze an untyped ptr: adr_type = %s",
1701            Type::str(adr_type));
1702     if (flat->isa_oopptr() && !flat->isa_klassptr()) {
1703       const TypeOopPtr* foop = flat->is_oopptr();
1704       // Scalarizable allocations have exact klass always.
1705       bool exact = !foop->klass_is_exact() || foop->is_known_instance();
1706       const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
1707       assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type: foop = %s; xoop = %s",
1708              Type::str(foop), Type::str(xoop));
1709     }
1710   }
1711 #endif
1712 
1713   int idx = AliasIdxTop;
1714   for (int i = 0; i < num_alias_types(); i++) {
1715     if (alias_type(i)->adr_type() == flat) {
1716       idx = i;
1717       break;
1718     }
1719   }
1720 
1721   if (idx == AliasIdxTop) {
1722     if (no_create)  return nullptr;
1723     // Grow the array if necessary.
1724     if (_num_alias_types == _max_alias_types)  grow_alias_types();
1725     // Add a new alias type.
1726     idx = _num_alias_types++;
1727     _alias_types[idx]->Init(idx, flat);
1728     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
1729     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
1730     if (flat->isa_instptr()) {
1731       if (flat->offset() == java_lang_Class::klass_offset()
1732           && flat->is_instptr()->instance_klass() == env()->Class_klass())
1733         alias_type(idx)->set_rewritable(false);
1734     }
1735     ciField* field = nullptr;
1736     if (flat->isa_aryptr()) {
1737 #ifdef ASSERT
1738       const int header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1739       // (T_BYTE has the weakest alignment and size restrictions...)
1740       assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
1741 #endif
1742       const Type* elemtype = flat->is_aryptr()->elem();
1743       if (flat->offset() == TypePtr::OffsetBot) {
1744         alias_type(idx)->set_element(elemtype);
1745       }
1746       int field_offset = flat->is_aryptr()->field_offset().get();
1747       if (flat->is_flat() &&
1748           field_offset != Type::OffsetBot) {
1749         ciInlineKlass* vk = elemtype->inline_klass();
1750         field_offset += vk->payload_offset();
1751         field = vk->get_field_by_offset(field_offset, false);
1752       }
1753     }
1754     if (flat->isa_klassptr()) {
1755       if (UseCompactObjectHeaders) {
1756         if (flat->offset() == in_bytes(Klass::prototype_header_offset()))
1757           alias_type(idx)->set_rewritable(false);
1758       }
1759       if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
1760         alias_type(idx)->set_rewritable(false);
1761       if (flat->offset() == in_bytes(Klass::misc_flags_offset()))
1762         alias_type(idx)->set_rewritable(false);
1763       if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
1764         alias_type(idx)->set_rewritable(false);
1765       if (flat->offset() == in_bytes(Klass::layout_helper_offset()))
1766         alias_type(idx)->set_rewritable(false);
1767       if (flat->offset() == in_bytes(Klass::secondary_super_cache_offset()))
1768         alias_type(idx)->set_rewritable(false);
1769     }
1770 
1771     if (flat->isa_instklassptr()) {
1772       if (flat->offset() == in_bytes(InstanceKlass::access_flags_offset())) {
1773         alias_type(idx)->set_rewritable(false);
1774       }
1775     }
1776     // %%% (We would like to finalize JavaThread::threadObj_offset(),
1777     // but the base pointer type is not distinctive enough to identify
1778     // references into JavaThread.)
1779 
1780     // Check for final fields.
1781     const TypeInstPtr* tinst = flat->isa_instptr();
1782     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
1783       if (tinst->const_oop() != nullptr &&
1784           tinst->instance_klass() == ciEnv::current()->Class_klass() &&
1785           tinst->offset() >= (tinst->instance_klass()->layout_helper_size_in_bytes())) {
1786         // static field
1787         ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
1788         field = k->get_field_by_offset(tinst->offset(), true);
1789       } else if (tinst->is_inlinetypeptr()) {
1790         // Inline type field
1791         ciInlineKlass* vk = tinst->inline_klass();
1792         field = vk->get_field_by_offset(tinst->offset(), false);
1793       } else {
1794         ciInstanceKlass *k = tinst->instance_klass();
1795         field = k->get_field_by_offset(tinst->offset(), false);
1796       }
1797     }
1798     assert(field == nullptr ||
1799            original_field == nullptr ||
1800            (field->holder() == original_field->holder() &&
1801             field->offset_in_bytes() == original_field->offset_in_bytes() &&
1802             field->is_static() == original_field->is_static()), "wrong field?");
1803     // Set field() and is_rewritable() attributes.
1804     if (field != nullptr) {
1805       alias_type(idx)->set_field(field);
1806       if (flat->isa_aryptr()) {
1807         // Fields of flat arrays are rewritable although they are declared final
1808         assert(flat->is_flat(), "must be a flat array");
1809         alias_type(idx)->set_rewritable(true);
1810       }
1811     }
1812   }
1813 
1814   // Fill the cache for next time.
1815   if (!uncached) {
1816     ace->_adr_type = adr_type;
1817     ace->_index    = idx;
1818     assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
1819 
1820     // Might as well try to fill the cache for the flattened version, too.
1821     AliasCacheEntry* face = probe_alias_cache(flat);
1822     if (face->_adr_type == nullptr) {
1823       face->_adr_type = flat;
1824       face->_index    = idx;
1825       assert(alias_type(flat) == alias_type(idx), "flat type must work too");
1826     }
1827   }
1828 
1829   return alias_type(idx);
1830 }
1831 
1832 
1833 Compile::AliasType* Compile::alias_type(ciField* field) {
1834   const TypeOopPtr* t;
1835   if (field->is_static())
1836     t = TypeInstPtr::make(field->holder()->java_mirror());
1837   else
1838     t = TypeOopPtr::make_from_klass_raw(field->holder());
1839   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);
1840   assert((field->is_final() || field->is_stable()) == !atp->is_rewritable(), "must get the rewritable bits correct");
1841   return atp;
1842 }
1843 
1844 
1845 //------------------------------have_alias_type--------------------------------
1846 bool Compile::have_alias_type(const TypePtr* adr_type) {
1847   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1848   if (ace->_adr_type == adr_type) {
1849     return true;
1850   }
1851 
1852   // Handle special cases.
1853   if (adr_type == nullptr)             return true;
1854   if (adr_type == TypePtr::BOTTOM)  return true;
1855 
1856   return find_alias_type(adr_type, true, nullptr) != nullptr;
1857 }
1858 
1859 //-----------------------------must_alias--------------------------------------
1860 // True if all values of the given address type are in the given alias category.
1861 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
1862   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1863   if (adr_type == nullptr)              return true;  // null serves as TypePtr::TOP
1864   if (alias_idx == AliasIdxTop)         return false; // the empty category
1865   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
1866 
1867   // the only remaining possible overlap is identity
1868   int adr_idx = get_alias_index(adr_type);
1869   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1870   assert(adr_idx == alias_idx ||
1871          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
1872           && adr_type                       != TypeOopPtr::BOTTOM),
1873          "should not be testing for overlap with an unsafe pointer");
1874   return adr_idx == alias_idx;
1875 }
1876 
1877 //------------------------------can_alias--------------------------------------
1878 // True if any values of the given address type are in the given alias category.
1879 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
1880   if (alias_idx == AliasIdxTop)         return false; // the empty category
1881   if (adr_type == nullptr)              return false; // null serves as TypePtr::TOP
1882   // Known instance doesn't alias with bottom memory
1883   if (alias_idx == AliasIdxBot)         return !adr_type->is_known_instance();                   // the universal category
1884   if (adr_type->base() == Type::AnyPtr) return !C->get_adr_type(alias_idx)->is_known_instance(); // TypePtr::BOTTOM or its twins
1885 
1886   // the only remaining possible overlap is identity
1887   int adr_idx = get_alias_index(adr_type);
1888   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1889   return adr_idx == alias_idx;
1890 }
1891 
1892 // Mark all ParsePredicateNodes as useless. They will later be removed from the graph in IGVN together with their
1893 // uncommon traps if no Runtime Predicates were created from the Parse Predicates.
1894 void Compile::mark_parse_predicate_nodes_useless(PhaseIterGVN& igvn) {
1895   if (parse_predicate_count() == 0) {
1896     return;
1897   }
1898   for (int i = 0; i < parse_predicate_count(); i++) {
1899     ParsePredicateNode* parse_predicate = _parse_predicates.at(i);
1900     parse_predicate->mark_useless(igvn);
1901   }
1902   _parse_predicates.clear();
1903 }
1904 
1905 void Compile::record_for_post_loop_opts_igvn(Node* n) {
1906   if (!n->for_post_loop_opts_igvn()) {
1907     assert(!_for_post_loop_igvn.contains(n), "duplicate");
1908     n->add_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
1909     _for_post_loop_igvn.append(n);
1910   }
1911 }
1912 
1913 void Compile::remove_from_post_loop_opts_igvn(Node* n) {
1914   n->remove_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
1915   _for_post_loop_igvn.remove(n);
1916 }
1917 
1918 void Compile::process_for_post_loop_opts_igvn(PhaseIterGVN& igvn) {
1919   // Verify that all previous optimizations produced a valid graph
1920   // at least to this point, even if no loop optimizations were done.
1921   PhaseIdealLoop::verify(igvn);
1922 
1923   if (_print_phase_loop_opts) {
1924     print_method(PHASE_AFTER_LOOP_OPTS, 2);
1925   }
1926   C->set_post_loop_opts_phase(); // no more loop opts allowed
1927 
1928   assert(!C->major_progress(), "not cleared");
1929 
1930   if (_for_post_loop_igvn.length() > 0) {
1931     while (_for_post_loop_igvn.length() > 0) {
1932       Node* n = _for_post_loop_igvn.pop();
1933       n->remove_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
1934       igvn._worklist.push(n);
1935     }
1936     igvn.optimize();
1937     if (failing()) return;
1938     assert(_for_post_loop_igvn.length() == 0, "no more delayed nodes allowed");
1939     assert(C->parse_predicate_count() == 0, "all parse predicates should have been removed now");
1940 
1941     // Sometimes IGVN sets major progress (e.g., when processing loop nodes).
1942     if (C->major_progress()) {
1943       C->clear_major_progress(); // ensure that major progress is now clear
1944     }
1945   }
1946 }
1947 
1948 void Compile::add_inline_type(Node* n) {
1949   assert(n->is_InlineType(), "unexpected node");
1950   _inline_type_nodes.push(n);
1951 }
1952 
1953 void Compile::remove_inline_type(Node* n) {
1954   assert(n->is_InlineType(), "unexpected node");
1955   if (_inline_type_nodes.contains(n)) {
1956     _inline_type_nodes.remove(n);
1957   }
1958 }
1959 
1960 // Does the return value keep otherwise useless inline type allocations alive?
1961 static bool return_val_keeps_allocations_alive(Node* ret_val) {
1962   ResourceMark rm;
1963   Unique_Node_List wq;
1964   wq.push(ret_val);
1965   bool some_allocations = false;
1966   for (uint i = 0; i < wq.size(); i++) {
1967     Node* n = wq.at(i);
1968     if (n->outcnt() > 1) {
1969       // Some other use for the allocation
1970       return false;
1971     } else if (n->is_InlineType()) {
1972       wq.push(n->in(1));
1973     } else if (n->is_Phi()) {
1974       for (uint j = 1; j < n->req(); j++) {
1975         wq.push(n->in(j));
1976       }
1977     } else if (n->is_CheckCastPP() &&
1978                n->in(1)->is_Proj() &&
1979                n->in(1)->in(0)->is_Allocate()) {
1980       some_allocations = true;
1981     } else if (n->is_CheckCastPP()) {
1982       wq.push(n->in(1));
1983     }
1984   }
1985   return some_allocations;
1986 }
1987 
1988 bool Compile::clear_argument_if_only_used_as_buffer_at_calls(Node* result_cast, PhaseIterGVN& igvn) {
1989   ResourceMark rm;
1990   Unique_Node_List wq;
1991   wq.push(result_cast);
1992   Node_List calls;
1993   for (uint i = 0; i < wq.size(); ++i) {
1994     Node* n = wq.at(i);
1995     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
1996       Node* u = n->fast_out(j);
1997       if (u->is_Phi()) {
1998         wq.push(u);
1999       } else if (u->is_InlineType() && u->as_InlineType()->get_oop() == n) {
2000         wq.push(u);
2001       } else if (u->is_CallJava()) {
2002         CallJavaNode* call = u->as_CallJava();
2003         if (call->method() != nullptr && call->method()->get_Method()->mismatch()) {
2004           return false;
2005         }
2006         uint nargs = call->tf()->domain_cc()->cnt();
2007         for (uint k = TypeFunc::Parms; k < nargs; k++) {
2008           Node* in = call->in(k);
2009           if (in == n && (call->method() == nullptr || !call->method()->is_scalarized_buffer_arg(k - TypeFunc::Parms))) {
2010             return false;
2011           }
2012         }
2013         calls.push(call);
2014       } else if (u->Opcode() == Op_EncodeP) {
2015         wq.push(u);
2016       } else if (u->is_AddP()) {
2017         wq.push(u);
2018       } else if (u->is_Store() && u->in(MemNode::Address) == n) {
2019         // storing to the buffer is fine
2020       } else if (u->is_SafePoint()) {
2021         SafePointNode* sfpt = u->as_SafePoint();
2022         int input = u->find_edge(n);
2023         JVMState* jvms = sfpt->jvms();
2024         if (jvms != nullptr) {
2025           if (input < (int)jvms->debug_start()) {
2026             return false;
2027           }
2028         }
2029       } else {
2030         return false;
2031       }
2032     }
2033   }
2034   for (uint i = 0; i < calls.size(); ++i) {
2035     CallJavaNode* call = calls.at(i)->as_CallJava();
2036     uint nargs = call->tf()->domain_cc()->cnt();
2037     for (uint k = TypeFunc::Parms; k < nargs; k++) {
2038       Node* in = call->in(k);
2039       if (wq.member(in)) {
2040         assert(call->method()->is_scalarized_buffer_arg(k - TypeFunc::Parms), "only buffer argument removed here");
2041         igvn.replace_input_of(call, k, igvn.zerocon(T_OBJECT));
2042       }
2043     }
2044   }
2045   return true;
2046 }
2047 
2048 void Compile::process_inline_types(PhaseIterGVN &igvn, bool remove) {
2049   // Make sure that the return value does not keep an otherwise unused allocation alive
2050   if (tf()->returns_inline_type_as_fields()) {
2051     Node* ret = nullptr;
2052     for (uint i = 1; i < root()->req(); i++) {
2053       Node* in = root()->in(i);
2054       if (in->Opcode() == Op_Return) {
2055         assert(ret == nullptr, "only one return");
2056         ret = in;
2057       }
2058     }
2059     if (ret != nullptr) {
2060       Node* ret_val = ret->in(TypeFunc::Parms);
2061       if (igvn.type(ret_val)->isa_oopptr() &&
2062           return_val_keeps_allocations_alive(ret_val)) {
2063         igvn.replace_input_of(ret, TypeFunc::Parms, InlineTypeNode::tagged_klass(igvn.type(ret_val)->inline_klass(), igvn));
2064         assert(ret_val->outcnt() == 0, "should be dead now");
2065         igvn.remove_dead_node(ret_val, PhaseIterGVN::NodeOrigin::Graph);
2066       }
2067     }
2068   }
2069   // if a newly allocated object is a value that's only passed as argument to calls as (possibly null) buffers, then
2070   // clear the call argument inputs so the allocation node can be removed
2071   for (int i = 0; i < C->macro_count(); ++i) {
2072     Node* macro_node = C->macro_node(i);
2073     if (macro_node->Opcode() == Op_Allocate) {
2074       AllocateNode* allocate = macro_node->as_Allocate();
2075       Node* result_cast = allocate->result_cast();
2076       if (result_cast != nullptr) {
2077         const Type* result_type = igvn.type(result_cast);
2078         if (result_type->is_inlinetypeptr()) {
2079           clear_argument_if_only_used_as_buffer_at_calls(result_cast, igvn);
2080         }
2081       }
2082     }
2083   }
2084 
2085   if (_inline_type_nodes.length() == 0) {
2086     // keep the graph canonical
2087     igvn.optimize();
2088     return;
2089   }
2090   // Scalarize inline types in safepoint debug info.
2091   // Delay this until all inlining is over to avoid getting inconsistent debug info.
2092   set_scalarize_in_safepoints(true);
2093   for (int i = _inline_type_nodes.length()-1; i >= 0; i--) {
2094     InlineTypeNode* vt = _inline_type_nodes.at(i)->as_InlineType();
2095     vt->make_scalar_in_safepoints(&igvn);
2096     igvn.record_for_igvn(vt);
2097   }
2098   if (remove) {
2099     // Remove inline type nodes by replacing them with their oop input
2100     while (_inline_type_nodes.length() > 0) {
2101       InlineTypeNode* vt = _inline_type_nodes.pop()->as_InlineType();
2102       if (vt->outcnt() == 0) {
2103         igvn.remove_dead_node(vt, PhaseIterGVN::NodeOrigin::Graph);
2104         continue;
2105       }
2106       for (DUIterator i = vt->outs(); vt->has_out(i); i++) {
2107         DEBUG_ONLY(bool must_be_buffered = false);
2108         Node* u = vt->out(i);
2109         // Check if any users are blackholes. If so, rewrite them to use either the
2110         // allocated buffer, or individual components, instead of the inline type node
2111         // that goes away.
2112         if (u->is_Blackhole()) {
2113           BlackholeNode* bh = u->as_Blackhole();
2114 
2115           // Unlink the old input
2116           int idx = bh->find_edge(vt);
2117           assert(idx != -1, "The edge should be there");
2118           bh->del_req(idx);
2119           --i;
2120 
2121           if (vt->is_allocated(&igvn)) {
2122             // Already has the allocated instance, blackhole that
2123             bh->add_req(vt->get_oop());
2124           } else {
2125             // Not allocated yet, blackhole the components
2126             for (uint c = 0; c < vt->field_count(); c++) {
2127               bh->add_req(vt->field_value(c));
2128             }
2129           }
2130 
2131           // Node modified, record for IGVN
2132           igvn.record_for_igvn(bh);
2133         }
2134 #ifdef ASSERT
2135         // Verify that inline type is buffered when replacing by oop
2136         else if (u->is_InlineType()) {
2137           // InlineType uses don't need buffering because they are about to be replaced as well
2138         } else if (u->is_Phi()) {
2139           // TODO 8302217 Remove this once InlineTypeNodes are reliably pushed through
2140         } else {
2141           must_be_buffered = true;
2142         }
2143         if (must_be_buffered && !vt->is_allocated(&igvn)) {
2144           vt->dump(0);
2145           u->dump(0);
2146           assert(false, "Should have been buffered");
2147         }
2148 #endif
2149       }
2150       igvn.replace_node(vt, vt->get_oop());
2151     }
2152   }
2153   igvn.optimize();
2154 }
2155 
2156 void Compile::add_flat_access(Node* n) {
2157   assert(n != nullptr && (n->Opcode() == Op_LoadFlat || n->Opcode() == Op_StoreFlat), "unexpected node %s", n == nullptr ? "nullptr" : n->Name());
2158   assert(!_flat_access_nodes.contains(n), "duplicate insertion");
2159   _flat_access_nodes.push(n);
2160 }
2161 
2162 void Compile::remove_flat_access(Node* n) {
2163   assert(n != nullptr && (n->Opcode() == Op_LoadFlat || n->Opcode() == Op_StoreFlat), "unexpected node %s", n == nullptr ? "nullptr" : n->Name());
2164   _flat_access_nodes.remove_if_existing(n);
2165 }
2166 
2167 void Compile::process_flat_accesses(PhaseIterGVN& igvn) {
2168   assert(igvn._worklist.size() == 0, "should be empty");
2169   igvn.set_delay_transform(true);
2170   for (int i = _flat_access_nodes.length() - 1; i >= 0; i--) {
2171     Node* n = _flat_access_nodes.at(i);
2172     assert(n != nullptr, "unexpected nullptr");
2173     if (n->is_LoadFlat()) {
2174       LoadFlatNode* loadn = n->as_LoadFlat();
2175       // Expending a flat load atomically means that we get a chunk of memory spanning multiple fields
2176       // that we chop with bitwise operations. That is too subtle for some optimizations, especially
2177       // constant folding when fields are constant. If we can get a constant object from which we are
2178       // flat-loading, we can simply replace the loads at compilation-time by the field of the constant
2179       // object.
2180       ciInstance* loaded_from = nullptr;
2181       if (FoldStableValues) {
2182         const TypeOopPtr* base_type = igvn.type(loadn->base())->is_oopptr();
2183         ciObject* oop = base_type->const_oop();
2184         int off = igvn.type(loadn->ptr())->isa_ptr()->offset();
2185 
2186         if (oop != nullptr && oop->is_instance()) {
2187           ciInstance* holder = oop->as_instance();
2188           ciKlass* klass = holder->klass();
2189           ciInstanceKlass* iklass = klass->as_instance_klass();
2190           ciField* field = iklass->get_non_flat_field_by_offset(off);
2191 
2192           if (field->is_stable()) {
2193             ciConstant fv = holder->field_value(field);
2194             if (is_reference_type(fv.basic_type()) && fv.as_object()->is_instance()) {
2195               // The field value is an object, not null. We can use stability.
2196               loaded_from = fv.as_object()->as_instance();
2197             }
2198           }
2199         } else if (oop != nullptr && oop->is_array() && off != Type::OffsetBot) {
2200           ciArray* array = oop->as_array();
2201           ciConstant elt = array->element_value_by_offset(off);
2202           const TypeAryPtr* aryptr = base_type->is_aryptr();
2203           if (aryptr->is_stable() && aryptr->is_atomic() && is_reference_type(elt.basic_type()) && elt.as_object()->is_instance()) {
2204             loaded_from = elt.as_object()->as_instance();
2205           }
2206         }
2207       }
2208 
2209       if (loaded_from != nullptr) {
2210         loadn->expand_constant(igvn, loaded_from);
2211       } else {
2212         loadn->expand_atomic(igvn);
2213       }
2214     } else {
2215       n->as_StoreFlat()->expand_atomic(igvn);
2216     }
2217   }
2218   _flat_access_nodes.clear_and_deallocate();
2219   igvn.set_delay_transform(false);
2220   igvn.optimize();
2221 }
2222 
2223 void Compile::adjust_flat_array_access_aliases(PhaseIterGVN& igvn) {
2224   DEBUG_ONLY(igvn.verify_empty_worklist(nullptr));
2225   if (!_has_flat_accesses) {
2226     return;
2227   }
2228   // Initially, all flat array accesses share the same slice to
2229   // keep dependencies with Object[] array accesses (that could be
2230   // to a flat array) correct. We're done with parsing so we
2231   // now know all flat array accesses in this compile
2232   // unit. Let's move flat array accesses to their own slice,
2233   // one per element field. This should help memory access
2234   // optimizations.
2235   ResourceMark rm;
2236   Unique_Node_List wq;
2237   wq.push(root());
2238 
2239   Node_List mergememnodes;
2240   Node_List memnodes;
2241 
2242   // Alias index currently shared by all flat memory accesses
2243   int index = get_alias_index(TypeAryPtr::INLINES);
2244 
2245   // Find MergeMem nodes and flat array accesses
2246   for (uint i = 0; i < wq.size(); i++) {
2247     Node* n = wq.at(i);
2248     if (n->is_Mem()) {
2249       const TypePtr* adr_type = nullptr;
2250       adr_type = get_adr_type(get_alias_index(n->adr_type()));
2251       if (adr_type == TypeAryPtr::INLINES) {
2252         memnodes.push(n);
2253       }
2254     } else if (n->is_MergeMem()) {
2255       MergeMemNode* mm = n->as_MergeMem();
2256       if (mm->memory_at(index) != mm->base_memory()) {
2257         mergememnodes.push(n);
2258       }
2259     }
2260     for (uint j = 0; j < n->req(); j++) {
2261       Node* m = n->in(j);
2262       if (m != nullptr) {
2263         wq.push(m);
2264       }
2265     }
2266   }
2267 
2268   _flat_accesses_share_alias = false;
2269 
2270   // We are going to change the slice for the flat array
2271   // accesses so we need to clear the cache entries that refer to
2272   // them.
2273   for (uint i = 0; i < AliasCacheSize; i++) {
2274     AliasCacheEntry* ace = &_alias_cache[i];
2275     if (ace->_adr_type != nullptr &&
2276         ace->_adr_type->is_flat()) {
2277       ace->_adr_type = nullptr;
2278       ace->_index = (i != 0) ? 0 : AliasIdxTop; // Make sure the nullptr adr_type resolves to AliasIdxTop
2279     }
2280   }
2281 
2282 #ifdef ASSERT
2283   for (uint i = 0; i < memnodes.size(); i++) {
2284     Node* m = memnodes.at(i);
2285     const TypePtr* adr_type = m->adr_type();
2286     m->as_Mem()->set_adr_type(adr_type);
2287   }
2288 #endif // ASSERT
2289 
2290   int start_alias = num_alias_types(); // Start of new aliases
2291   Node_Stack stack(0);
2292 #ifdef ASSERT
2293   VectorSet seen(Thread::current()->resource_area());
2294 #endif
2295   // Now let's fix the memory graph so each flat array access
2296   // is moved to the right slice. Start from the MergeMem nodes.
2297   uint last = unique();
2298   for (uint i = 0; i < mergememnodes.size(); i++) {
2299     MergeMemNode* current = mergememnodes.at(i)->as_MergeMem();
2300     if (current->outcnt() == 0) {
2301       // This node is killed by a previous iteration
2302       continue;
2303     }
2304 
2305     Node* n = current->memory_at(index);
2306     MergeMemNode* mm = nullptr;
2307     do {
2308       // Follow memory edges through memory accesses, phis and
2309       // narrow membars and push nodes on the stack. Once we hit
2310       // bottom memory, we pop element off the stack one at a
2311       // time, in reverse order, and move them to the right slice
2312       // by changing their memory edges.
2313       if ((n->is_Phi() && n->adr_type() != TypePtr::BOTTOM) || n->is_Mem() ||
2314           (n->adr_type() == TypeAryPtr::INLINES && !n->is_NarrowMemProj())) {
2315         assert(!seen.test_set(n->_idx), "");
2316         // Uses (a load for instance) will need to be moved to the
2317         // right slice as well and will get a new memory state
2318         // that we don't know yet. The use could also be the
2319         // backedge of a loop. We put a place holder node between
2320         // the memory node and its uses. We replace that place
2321         // holder with the correct memory state once we know it,
2322         // i.e. when nodes are popped off the stack. Using the
2323         // place holder make the logic work in the presence of
2324         // loops.
2325         if (n->outcnt() > 1) {
2326           Node* place_holder = nullptr;
2327           assert(!n->has_out_with(Op_Node), "");
2328           for (DUIterator k = n->outs(); n->has_out(k); k++) {
2329             Node* u = n->out(k);
2330             if (u != current && u->_idx < last) {
2331               bool success = false;
2332               for (uint l = 0; l < u->req(); l++) {
2333                 if (!stack.is_empty() && u == stack.node() && l == stack.index()) {
2334                   continue;
2335                 }
2336                 Node* in = u->in(l);
2337                 if (in == n) {
2338                   if (place_holder == nullptr) {
2339                     place_holder = new Node(1);
2340                     place_holder->init_req(0, n);
2341                   }
2342                   igvn.replace_input_of(u, l, place_holder);
2343                   success = true;
2344                 }
2345               }
2346               if (success) {
2347                 --k;
2348               }
2349             }
2350           }
2351         }
2352         if (n->is_Phi()) {
2353           stack.push(n, 1);
2354           n = n->in(1);
2355         } else if (n->is_Mem()) {
2356           stack.push(n, n->req());
2357           n = n->in(MemNode::Memory);
2358         } else {
2359           assert(n->is_Proj() && n->in(0)->Opcode() == Op_MemBarCPUOrder, "");
2360           stack.push(n, n->req());
2361           n = n->in(0)->in(TypeFunc::Memory);
2362         }
2363       } else {
2364         assert(n->adr_type() == TypePtr::BOTTOM || (n->Opcode() == Op_Node && n->_idx >= last) || n->is_NarrowMemProj(), "");
2365         // Build a new MergeMem node to carry the new memory state
2366         // as we build it. IGVN should fold extraneous MergeMem
2367         // nodes.
2368         if (n->is_NarrowMemProj()) {
2369           // We need 1 NarrowMemProj for each slice of this array
2370           InitializeNode* init = n->in(0)->as_Initialize();
2371           AllocateNode* alloc = init->allocation();
2372           Node* klass_node = alloc->in(AllocateNode::KlassNode);
2373           const TypeAryKlassPtr* klass_type = klass_node->bottom_type()->isa_aryklassptr();
2374           assert(klass_type != nullptr, "must be an array");
2375           assert(klass_type->klass_is_exact(), "must be an exact klass");
2376           ciArrayKlass* klass = klass_type->exact_klass()->as_array_klass();
2377           assert(klass->is_flat_array_klass(), "must be a flat array");
2378           ciInlineKlass* elem_klass = klass->element_klass()->as_inline_klass();
2379           const TypeAryPtr* oop_type = klass_type->as_instance_type()->is_aryptr();
2380           assert(oop_type->klass_is_exact(), "must be an exact klass");
2381 
2382           Node* base = alloc->in(TypeFunc::Memory);
2383           assert(base->bottom_type() == Type::MEMORY, "the memory input of AllocateNode must be a memory");
2384           assert(base->adr_type() == TypePtr::BOTTOM, "the memory input of AllocateNode must be a bottom memory");
2385           // Must create a MergeMem with base as the base memory, do not clone if base is a
2386           // MergeMem because it may not be processed yet
2387           mm = MergeMemNode::make(nullptr);
2388           mm->set_base_memory(base);
2389           for (int j = 0; j < elem_klass->nof_nonstatic_fields(); j++) {
2390             int field_offset = elem_klass->nonstatic_field_at(j)->offset_in_bytes() - elem_klass->payload_offset();
2391             const TypeAryPtr* field_ptr = oop_type->with_offset(Type::OffsetBot)->with_field_offset(field_offset);
2392             int field_alias_idx = get_alias_index(field_ptr);
2393             assert(field_ptr == get_adr_type(field_alias_idx), "must match");
2394             Node* new_proj = new NarrowMemProjNode(init, field_ptr);
2395             igvn.register_new_node_with_optimizer(new_proj);
2396             mm->set_memory_at(field_alias_idx, new_proj);
2397           }
2398           if (!klass->is_elem_null_free()) {
2399             int nm_offset = elem_klass->null_marker_offset_in_payload();
2400             const TypeAryPtr* nm_ptr = oop_type->with_offset(Type::OffsetBot)->with_field_offset(nm_offset);
2401             int nm_alias_idx = get_alias_index(nm_ptr);
2402             assert(nm_ptr == get_adr_type(nm_alias_idx), "must match");
2403             Node* new_proj = new NarrowMemProjNode(init, nm_ptr);
2404             igvn.register_new_node_with_optimizer(new_proj);
2405             mm->set_memory_at(nm_alias_idx, new_proj);
2406           }
2407 
2408           // Replace all uses of the old NarrowMemProj with the correct state
2409           MergeMemNode* new_n = MergeMemNode::make(mm);
2410           igvn.register_new_node_with_optimizer(new_n);
2411           igvn.replace_node(n, new_n);
2412         } else {
2413           // Must create a MergeMem with n as the base memory, do not clone if n is a MergeMem
2414           // because it may not be processed yet
2415           mm = MergeMemNode::make(nullptr);
2416           mm->set_base_memory(n);
2417         }
2418 
2419         igvn.register_new_node_with_optimizer(mm);
2420         while (stack.size() > 0) {
2421           Node* m = stack.node();
2422           uint idx = stack.index();
2423           if (m->is_Mem()) {
2424             // Move memory node to its new slice
2425             const TypePtr* adr_type = m->adr_type();
2426             int alias = get_alias_index(adr_type);
2427             Node* prev = mm->memory_at(alias);
2428             igvn.replace_input_of(m, MemNode::Memory, prev);
2429             mm->set_memory_at(alias, m);
2430           } else if (m->is_Phi()) {
2431             // We need as many new phis as there are new aliases
2432             Node* new_phi_in = MergeMemNode::make(mm);
2433             igvn.register_new_node_with_optimizer(new_phi_in);
2434             igvn.replace_input_of(m, idx, new_phi_in);
2435             if (idx == m->req()-1) {
2436               Node* r = m->in(0);
2437               for (int j = start_alias; j < num_alias_types(); j++) {
2438                 const TypePtr* adr_type = get_adr_type(j);
2439                 if (!adr_type->isa_aryptr() || !adr_type->is_flat()) {
2440                   continue;
2441                 }
2442                 Node* phi = new PhiNode(r, Type::MEMORY, get_adr_type(j));
2443                 igvn.register_new_node_with_optimizer(phi);
2444                 for (uint k = 1; k < m->req(); k++) {
2445                   phi->init_req(k, m->in(k)->as_MergeMem()->memory_at(j));
2446                 }
2447                 mm->set_memory_at(j, phi);
2448               }
2449               Node* base_phi = new PhiNode(r, Type::MEMORY, TypePtr::BOTTOM);
2450               igvn.register_new_node_with_optimizer(base_phi);
2451               for (uint k = 1; k < m->req(); k++) {
2452                 base_phi->init_req(k, m->in(k)->as_MergeMem()->base_memory());
2453               }
2454               mm->set_base_memory(base_phi);
2455             }
2456           } else {
2457             // This is a MemBarCPUOrder node from
2458             // Parse::array_load()/Parse::array_store(), in the
2459             // branch that handles flat arrays hidden under
2460             // an Object[] array. We also need one new membar per
2461             // new alias to keep the unknown access that the
2462             // membars protect properly ordered with accesses to
2463             // known flat array.
2464             assert(m->is_Proj(), "projection expected");
2465             Node* ctrl = m->in(0)->in(TypeFunc::Control);
2466             igvn.replace_input_of(m->in(0), TypeFunc::Control, top());
2467             for (int j = start_alias; j < num_alias_types(); j++) {
2468               const TypePtr* adr_type = get_adr_type(j);
2469               if (!adr_type->isa_aryptr() || !adr_type->is_flat()) {
2470                 continue;
2471               }
2472               MemBarNode* mb = new MemBarCPUOrderNode(this, j, nullptr);
2473               igvn.register_new_node_with_optimizer(mb);
2474               Node* mem = mm->memory_at(j);
2475               mb->init_req(TypeFunc::Control, ctrl);
2476               mb->init_req(TypeFunc::Memory, mem);
2477               ctrl = new ProjNode(mb, TypeFunc::Control);
2478               igvn.register_new_node_with_optimizer(ctrl);
2479               mem = new ProjNode(mb, TypeFunc::Memory);
2480               igvn.register_new_node_with_optimizer(mem);
2481               mm->set_memory_at(j, mem);
2482             }
2483             igvn.replace_node(m->in(0)->as_Multi()->proj_out(TypeFunc::Control), ctrl);
2484           }
2485           if (idx < m->req()-1) {
2486             idx += 1;
2487             stack.set_index(idx);
2488             n = m->in(idx);
2489             break;
2490           }
2491           // Take care of place holder nodes
2492           if (m->has_out_with(Op_Node)) {
2493             Node* place_holder = m->find_out_with(Op_Node);
2494             if (place_holder != nullptr) {
2495               Node* mm_clone = mm->clone();
2496               igvn.register_new_node_with_optimizer(mm_clone);
2497               Node* hook = new Node(1);
2498               hook->init_req(0, mm);
2499               igvn.replace_node(place_holder, mm_clone);
2500               hook->destruct(&igvn);
2501             }
2502             assert(!m->has_out_with(Op_Node), "place holder should be gone now");
2503           }
2504           stack.pop();
2505         }
2506       }
2507     } while(stack.size() > 0);
2508     // Fix the memory state at the MergeMem we started from
2509     igvn.rehash_node_delayed(current);
2510     for (int j = start_alias; j < num_alias_types(); j++) {
2511       const TypePtr* adr_type = get_adr_type(j);
2512       if (!adr_type->isa_aryptr() || !adr_type->is_flat()) {
2513         continue;
2514       }
2515       current->set_memory_at(j, mm);
2516     }
2517     current->set_memory_at(index, current->base_memory());
2518   }
2519   igvn.optimize();
2520 
2521 #ifdef ASSERT
2522   wq.clear();
2523   wq.push(root());
2524   for (uint i = 0; i < wq.size(); i++) {
2525     Node* n = wq.at(i);
2526     assert(n->adr_type() != TypeAryPtr::INLINES, "should have been removed from the graph");
2527     for (uint j = 0; j < n->req(); j++) {
2528       Node* m = n->in(j);
2529       if (m != nullptr) {
2530         wq.push(m);
2531       }
2532     }
2533   }
2534 #endif
2535 
2536   print_method(PHASE_SPLIT_INLINES_ARRAY, 2);
2537 }
2538 
2539 void Compile::record_for_merge_stores_igvn(Node* n) {
2540   if (!n->for_merge_stores_igvn()) {
2541     assert(!_for_merge_stores_igvn.contains(n), "duplicate");
2542     n->add_flag(Node::NodeFlags::Flag_for_merge_stores_igvn);
2543     _for_merge_stores_igvn.append(n);
2544   }
2545 }
2546 
2547 void Compile::remove_from_merge_stores_igvn(Node* n) {
2548   n->remove_flag(Node::NodeFlags::Flag_for_merge_stores_igvn);
2549   _for_merge_stores_igvn.remove(n);
2550 }
2551 
2552 // We need to wait with merging stores until RangeCheck smearing has removed the RangeChecks during
2553 // the post loops IGVN phase. If we do it earlier, then there may still be some RangeChecks between
2554 // the stores, and we merge the wrong sequence of stores.
2555 // Example:
2556 //   StoreI RangeCheck StoreI StoreI RangeCheck StoreI
2557 // Apply MergeStores:
2558 //   StoreI RangeCheck [   StoreL  ] RangeCheck StoreI
2559 // Remove more RangeChecks:
2560 //   StoreI            [   StoreL  ]            StoreI
2561 // But now it would have been better to do this instead:
2562 //   [         StoreL       ] [       StoreL         ]
2563 //
2564 // Note: we allow stores to merge in this dedicated IGVN round, and any later IGVN round,
2565 //       since we never unset _merge_stores_phase.
2566 void Compile::process_for_merge_stores_igvn(PhaseIterGVN& igvn) {
2567   C->set_merge_stores_phase();
2568 
2569   if (_for_merge_stores_igvn.length() > 0) {
2570     while (_for_merge_stores_igvn.length() > 0) {
2571       Node* n = _for_merge_stores_igvn.pop();
2572       n->remove_flag(Node::NodeFlags::Flag_for_merge_stores_igvn);
2573       igvn._worklist.push(n);
2574     }
2575     igvn.optimize();
2576     if (failing()) return;
2577     assert(_for_merge_stores_igvn.length() == 0, "no more delayed nodes allowed");
2578     print_method(PHASE_AFTER_MERGE_STORES, 3);
2579   }
2580 }
2581 
2582 void Compile::record_unstable_if_trap(UnstableIfTrap* trap) {
2583   if (OptimizeUnstableIf) {
2584     _unstable_if_traps.append(trap);
2585   }
2586 }
2587 
2588 void Compile::remove_useless_unstable_if_traps(Unique_Node_List& useful) {
2589   for (int i = _unstable_if_traps.length() - 1; i >= 0; i--) {
2590     UnstableIfTrap* trap = _unstable_if_traps.at(i);
2591     Node* n = trap->uncommon_trap();
2592     if (!useful.member(n)) {
2593       _unstable_if_traps.delete_at(i); // replaces i-th with last element which is known to be useful (already processed)
2594     }
2595   }
2596 }
2597 
2598 // Remove the unstable if trap associated with 'unc' from candidates. It is either dead
2599 // or fold-compares case. Return true if succeed or not found.
2600 //
2601 // In rare cases, the found trap has been processed. It is too late to delete it. Return
2602 // false and ask fold-compares to yield.
2603 //
2604 // 'fold-compares' may use the uncommon_trap of the dominating IfNode to cover the fused
2605 // IfNode. This breaks the unstable_if trap invariant: control takes the unstable path
2606 // when deoptimization does happen.
2607 bool Compile::remove_unstable_if_trap(CallStaticJavaNode* unc, bool yield) {
2608   for (int i = 0; i < _unstable_if_traps.length(); ++i) {
2609     UnstableIfTrap* trap = _unstable_if_traps.at(i);
2610     if (trap->uncommon_trap() == unc) {
2611       if (yield && trap->modified()) {
2612         return false;
2613       }
2614       _unstable_if_traps.delete_at(i);
2615       break;
2616     }
2617   }
2618   return true;
2619 }
2620 
2621 // Re-calculate unstable_if traps with the liveness of next_bci, which points to the unlikely path.
2622 // It needs to be done after igvn because fold-compares may fuse uncommon_traps and before renumbering.
2623 void Compile::process_for_unstable_if_traps(PhaseIterGVN& igvn) {
2624   for (int i = _unstable_if_traps.length() - 1; i >= 0; --i) {
2625     UnstableIfTrap* trap = _unstable_if_traps.at(i);
2626     CallStaticJavaNode* unc = trap->uncommon_trap();
2627     int next_bci = trap->next_bci();
2628     bool modified = trap->modified();
2629 
2630     if (next_bci != -1 && !modified) {
2631       assert(!_dead_node_list.test(unc->_idx), "changing a dead node!");
2632       JVMState* jvms = unc->jvms();
2633       ciMethod* method = jvms->method();
2634       ciBytecodeStream iter(method);
2635 
2636       iter.force_bci(jvms->bci());
2637       assert(next_bci == iter.next_bci() || next_bci == iter.get_dest(), "wrong next_bci at unstable_if");
2638       Bytecodes::Code c = iter.cur_bc();
2639       Node* lhs = nullptr;
2640       Node* rhs = nullptr;
2641       if (c == Bytecodes::_if_acmpeq || c == Bytecodes::_if_acmpne) {
2642         lhs = unc->peek_operand(0);
2643         rhs = unc->peek_operand(1);
2644       } else if (c == Bytecodes::_ifnull || c == Bytecodes::_ifnonnull) {
2645         lhs = unc->peek_operand(0);
2646       }
2647 
2648       ResourceMark rm;
2649       const MethodLivenessResult& live_locals = method->liveness_at_bci(next_bci);
2650       assert(live_locals.is_valid(), "broken liveness info");
2651       int len = (int)live_locals.size();
2652 
2653       for (int i = 0; i < len; i++) {
2654         Node* local = unc->local(jvms, i);
2655         // kill local using the liveness of next_bci.
2656         // give up when the local looks like an operand to secure reexecution.
2657         if (!live_locals.at(i) && !local->is_top() && local != lhs && local != rhs) {
2658           uint idx = jvms->locoff() + i;
2659 #ifdef ASSERT
2660           if (PrintOpto && Verbose) {
2661             tty->print("[unstable_if] kill local#%d: ", idx);
2662             local->dump();
2663             tty->cr();
2664           }
2665 #endif
2666           igvn.replace_input_of(unc, idx, top());
2667           modified = true;
2668         }
2669       }
2670     }
2671 
2672     // keep the modified trap for late query
2673     if (modified) {
2674       trap->set_modified();
2675     } else {
2676       _unstable_if_traps.delete_at(i);
2677     }
2678   }
2679   igvn.optimize();
2680 }
2681 
2682 // StringOpts and late inlining of string methods
2683 void Compile::inline_string_calls(bool parse_time) {
2684   {
2685     // remove useless nodes to make the usage analysis simpler
2686     ResourceMark rm;
2687     PhaseRemoveUseless pru(initial_gvn(), *igvn_worklist());
2688   }
2689 
2690   {
2691     ResourceMark rm;
2692     print_method(PHASE_BEFORE_STRINGOPTS, 3);
2693     PhaseStringOpts pso(initial_gvn());
2694     print_method(PHASE_AFTER_STRINGOPTS, 3);
2695   }
2696 
2697   // now inline anything that we skipped the first time around
2698   if (!parse_time) {
2699     _late_inlines_pos = _late_inlines.length();
2700   }
2701 
2702   while (_string_late_inlines.length() > 0) {
2703     CallGenerator* cg = _string_late_inlines.pop();
2704     cg->do_late_inline();
2705     if (failing())  return;
2706   }
2707   _string_late_inlines.trunc_to(0);
2708 }
2709 
2710 // Late inlining of boxing methods
2711 void Compile::inline_boxing_calls(PhaseIterGVN& igvn) {
2712   if (_boxing_late_inlines.length() > 0) {
2713     assert(has_boxed_value(), "inconsistent");
2714 
2715     set_inlining_incrementally(true);
2716 
2717     igvn_worklist()->ensure_empty(); // should be done with igvn
2718 
2719     _late_inlines_pos = _late_inlines.length();
2720 
2721     while (_boxing_late_inlines.length() > 0) {
2722       CallGenerator* cg = _boxing_late_inlines.pop();
2723       cg->do_late_inline();
2724       if (failing())  return;
2725     }
2726     _boxing_late_inlines.trunc_to(0);
2727 
2728     inline_incrementally_cleanup(igvn);
2729 
2730     set_inlining_incrementally(false);
2731   }
2732 }
2733 
2734 bool Compile::inline_incrementally_one() {
2735   assert(IncrementalInline, "incremental inlining should be on");
2736   assert(_late_inlines.length() > 0, "should have been checked by caller");
2737 
2738   TracePhase tp(_t_incrInline_inline);
2739 
2740   set_inlining_progress(false);
2741   set_do_cleanup(false);
2742 
2743   for (int i = 0; i < _late_inlines.length(); i++) {
2744     _late_inlines_pos = i+1;
2745     CallGenerator* cg = _late_inlines.at(i);
2746     bool is_scheduled_for_igvn_before = C->igvn_worklist()->member(cg->call_node());
2747     bool does_dispatch = cg->is_virtual_late_inline() || cg->is_mh_late_inline();
2748     if (inlining_incrementally() || does_dispatch) { // a call can be either inlined or strength-reduced to a direct call
2749       if (should_stress_inlining()) {
2750         // randomly add repeated inline attempt if stress-inlining
2751         cg->call_node()->set_generator(cg);
2752         C->igvn_worklist()->push(cg->call_node());
2753         continue;
2754       }
2755       cg->do_late_inline();
2756       assert(_late_inlines.at(i) == cg, "no insertions before current position allowed");
2757       if (failing()) {
2758         return false;
2759       } else if (inlining_progress()) {
2760         _late_inlines_pos = i+1; // restore the position in case new elements were inserted
2761         print_method(PHASE_INCREMENTAL_INLINE_STEP, 3, cg->call_node());
2762         break; // process one call site at a time
2763       } else {
2764         bool is_scheduled_for_igvn_after = C->igvn_worklist()->member(cg->call_node());
2765         if (!is_scheduled_for_igvn_before && is_scheduled_for_igvn_after) {
2766           // Avoid potential infinite loop if node already in the IGVN list
2767           assert(false, "scheduled for IGVN during inlining attempt");
2768         } else {
2769           // Ensure call node has not disappeared from IGVN worklist during a failed inlining attempt
2770           assert(!is_scheduled_for_igvn_before || is_scheduled_for_igvn_after, "call node removed from IGVN list during inlining pass");
2771           cg->call_node()->set_generator(cg);
2772         }
2773       }
2774     } else {
2775       // Ignore late inline direct calls when inlining is not allowed.
2776       // They are left in the late inline list when node budget is exhausted until the list is fully drained.
2777     }
2778   }
2779   // Remove processed elements.
2780   _late_inlines.remove_till(_late_inlines_pos);
2781   _late_inlines_pos = 0;
2782 
2783   assert(inlining_progress() || _late_inlines.length() == 0, "no progress");
2784 
2785   bool needs_cleanup = do_cleanup() || over_inlining_cutoff();
2786 
2787   set_inlining_progress(false);
2788   set_do_cleanup(false);
2789 
2790   bool force_cleanup = directive()->IncrementalInlineForceCleanupOption;
2791   return (_late_inlines.length() > 0) && !needs_cleanup && !force_cleanup;
2792 }
2793 
2794 void Compile::inline_incrementally_cleanup(PhaseIterGVN& igvn) {
2795   {
2796     TracePhase tp(_t_incrInline_pru);
2797     ResourceMark rm;
2798     PhaseRemoveUseless pru(initial_gvn(), *igvn_worklist());
2799   }
2800   {
2801     TracePhase tp(_t_incrInline_igvn);
2802     igvn.reset();
2803     igvn.optimize();
2804     if (failing()) return;
2805   }
2806   print_method(PHASE_INCREMENTAL_INLINE_CLEANUP, 3);
2807 }
2808 
2809 template<typename E>
2810 static void shuffle_array(Compile& C, GrowableArray<E>& array) {
2811   if (array.length() < 2) {
2812     return;
2813   }
2814   for (uint i = array.length() - 1; i >= 1; i--) {
2815     uint j = C.random() % (i + 1);
2816     swap(array.at(i), array.at(j));
2817   }
2818 }
2819 
2820 void Compile::shuffle_late_inlines() {
2821   shuffle_array(*C, _late_inlines);
2822 }
2823 
2824 // Perform incremental inlining until bound on number of live nodes is reached
2825 void Compile::inline_incrementally(PhaseIterGVN& igvn) {
2826   TracePhase tp(_t_incrInline);
2827 
2828   set_inlining_incrementally(true);
2829   uint low_live_nodes = 0;
2830 
2831   if (StressIncrementalInlining) {
2832     shuffle_late_inlines();
2833   }
2834 
2835   while (_late_inlines.length() > 0) {
2836     if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2837       if (low_live_nodes < (uint)LiveNodeCountInliningCutoff * 8 / 10) {
2838         TracePhase tp(_t_incrInline_ideal);
2839         // PhaseIdealLoop is expensive so we only try it once we are
2840         // out of live nodes and we only try it again if the previous
2841         // helped got the number of nodes down significantly
2842         PhaseIdealLoop::optimize(igvn, LoopOptsNone);
2843         if (failing())  return;
2844         low_live_nodes = live_nodes();
2845         _major_progress = true;
2846       }
2847 
2848       if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2849         bool do_print_inlining = print_inlining() || print_intrinsics();
2850         if (do_print_inlining || log() != nullptr) {
2851           // Print inlining message for candidates that we couldn't inline for lack of space.
2852           for (int i = 0; i < _late_inlines.length(); i++) {
2853             CallGenerator* cg = _late_inlines.at(i);
2854             const char* msg = "live nodes > LiveNodeCountInliningCutoff";
2855             if (do_print_inlining) {
2856               inline_printer()->record(cg->method(), cg->call_node()->jvms(), InliningResult::FAILURE, msg);
2857             }
2858             log_late_inline_failure(cg, msg);
2859           }
2860         }
2861         break; // finish
2862       }
2863     }
2864 
2865     igvn_worklist()->ensure_empty(); // should be done with igvn
2866 
2867     if (_late_inlines.length() == 0) {
2868       break; // no more progress
2869     }
2870 
2871     while (inline_incrementally_one()) {
2872       assert(!failing_internal() || failure_is_artificial(), "inconsistent");
2873     }
2874     if (failing())  return;
2875 
2876     inline_incrementally_cleanup(igvn);
2877 
2878     print_method(PHASE_INCREMENTAL_INLINE_STEP, 3);
2879 
2880     if (failing())  return;
2881   }
2882 
2883   igvn_worklist()->ensure_empty(); // should be done with igvn
2884 
2885   if (_string_late_inlines.length() > 0) {
2886     assert(has_stringbuilder(), "inconsistent");
2887 
2888     inline_string_calls(false);
2889 
2890     if (failing())  return;
2891 
2892     inline_incrementally_cleanup(igvn);
2893   }
2894 
2895   set_inlining_incrementally(false);
2896 }
2897 
2898 void Compile::process_late_inline_calls_no_inline(PhaseIterGVN& igvn) {
2899   // "inlining_incrementally() == false" is used to signal that no inlining is allowed
2900   // (see LateInlineVirtualCallGenerator::do_late_inline_check() for details).
2901   // Tracking and verification of modified nodes is disabled by setting "_modified_nodes == nullptr"
2902   // as if "inlining_incrementally() == true" were set.
2903   assert(inlining_incrementally() == false, "not allowed");
2904   set_strength_reduction(true);
2905 #ifdef ASSERT
2906   Unique_Node_List* modified_nodes = _modified_nodes;
2907   _modified_nodes = nullptr;
2908 #endif
2909   assert(_late_inlines.length() > 0, "sanity");
2910 
2911   if (StressIncrementalInlining) {
2912     shuffle_late_inlines();
2913   }
2914 
2915   while (_late_inlines.length() > 0) {
2916     igvn_worklist()->ensure_empty(); // should be done with igvn
2917 
2918     while (inline_incrementally_one()) {
2919       assert(!failing_internal() || failure_is_artificial(), "inconsistent");
2920     }
2921     if (failing())  return;
2922 
2923     inline_incrementally_cleanup(igvn);
2924   }
2925   DEBUG_ONLY( _modified_nodes = modified_nodes; )
2926   set_strength_reduction(false);
2927 }
2928 
2929 bool Compile::optimize_loops(PhaseIterGVN& igvn, LoopOptsMode mode) {
2930   if (_loop_opts_cnt > 0) {
2931     while (major_progress() && (_loop_opts_cnt > 0)) {
2932       TracePhase tp(_t_idealLoop);
2933       PhaseIdealLoop::optimize(igvn, mode);
2934       _loop_opts_cnt--;
2935       if (failing())  return false;
2936       if (major_progress()) {
2937         print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
2938       }
2939     }
2940   }
2941   return true;
2942 }
2943 
2944 // Remove edges from "root" to each SafePoint at a backward branch.
2945 // They were inserted during parsing (see add_safepoint()) to make
2946 // infinite loops without calls or exceptions visible to root, i.e.,
2947 // useful.
2948 void Compile::remove_root_to_sfpts_edges(PhaseIterGVN& igvn) {
2949   Node *r = root();
2950   if (r != nullptr) {
2951     for (uint i = r->req(); i < r->len(); ++i) {
2952       Node *n = r->in(i);
2953       if (n != nullptr && n->is_SafePoint()) {
2954         r->rm_prec(i);
2955         if (n->outcnt() == 0) {
2956           igvn.remove_dead_node(n, PhaseIterGVN::NodeOrigin::Graph);
2957         }
2958         --i;
2959       }
2960     }
2961     // Parsing may have added top inputs to the root node (Path
2962     // leading to the Halt node proven dead). Make sure we get a
2963     // chance to clean them up.
2964     igvn._worklist.push(r);
2965     igvn.optimize();
2966   }
2967 }
2968 
2969 //------------------------------Optimize---------------------------------------
2970 // Given a graph, optimize it.
2971 void Compile::Optimize() {
2972   TracePhase tp(_t_optimizer);
2973 
2974 #ifndef PRODUCT
2975   if (env()->break_at_compile()) {
2976     BREAKPOINT;
2977   }
2978 
2979 #endif
2980 
2981   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
2982 #ifdef ASSERT
2983   bs->verify_gc_barriers(this, BarrierSetC2::BeforeOptimize);
2984 #endif
2985 
2986   ResourceMark rm;
2987 
2988   NOT_PRODUCT( verify_graph_edges(); )
2989 
2990   print_method(PHASE_AFTER_PARSING, 1);
2991 
2992  {
2993   // Iterative Global Value Numbering, including ideal transforms
2994   PhaseIterGVN igvn;
2995 #ifdef ASSERT
2996   _modified_nodes = new (comp_arena()) Unique_Node_List(comp_arena());
2997 #endif
2998   {
2999     TracePhase tp(_t_iterGVN);
3000     igvn.optimize(true);
3001   }
3002 
3003   if (failing())  return;
3004 
3005   print_method(PHASE_ITER_GVN1, 2);
3006 
3007   process_for_unstable_if_traps(igvn);
3008 
3009   if (failing())  return;
3010 
3011   inline_incrementally(igvn);
3012 
3013   print_method(PHASE_INCREMENTAL_INLINE, 2);
3014 
3015   if (failing())  return;
3016 
3017   if (eliminate_boxing()) {
3018     // Inline valueOf() methods now.
3019     inline_boxing_calls(igvn);
3020 
3021     if (failing())  return;
3022 
3023     if (AlwaysIncrementalInline || StressIncrementalInlining) {
3024       inline_incrementally(igvn);
3025     }
3026 
3027     print_method(PHASE_INCREMENTAL_BOXING_INLINE, 2);
3028 
3029     if (failing())  return;
3030   }
3031 
3032   // Remove the speculative part of types and clean up the graph from
3033   // the extra CastPP nodes whose only purpose is to carry them. Do
3034   // that early so that optimizations are not disrupted by the extra
3035   // CastPP nodes.
3036   remove_speculative_types(igvn);
3037 
3038   if (failing())  return;
3039 
3040   // No more new expensive nodes will be added to the list from here
3041   // so keep only the actual candidates for optimizations.
3042   cleanup_expensive_nodes(igvn);
3043 
3044   if (failing())  return;
3045 
3046   assert(EnableVectorSupport || !has_vbox_nodes(), "sanity");
3047   if (EnableVectorSupport && has_vbox_nodes()) {
3048     TracePhase tp(_t_vector);
3049     PhaseVector pv(igvn);
3050     pv.optimize_vector_boxes();
3051     if (failing())  return;
3052     print_method(PHASE_ITER_GVN_AFTER_VECTOR, 2);
3053   }
3054   assert(!has_vbox_nodes(), "sanity");
3055 
3056   if (!failing() && RenumberLiveNodes && live_nodes() + NodeLimitFudgeFactor < unique()) {
3057     Compile::TracePhase tp(_t_renumberLive);
3058     igvn_worklist()->ensure_empty(); // should be done with igvn
3059     {
3060       ResourceMark rm;
3061       PhaseRenumberLive prl(initial_gvn(), *igvn_worklist());
3062     }
3063     igvn.reset();
3064     igvn.optimize(true);
3065     if (failing()) return;
3066   }
3067 
3068   // Now that all inlining is over and no PhaseRemoveUseless will run, cut edge from root to loop
3069   // safepoints
3070   remove_root_to_sfpts_edges(igvn);
3071 
3072   // Process inline type nodes now that all inlining is over
3073   process_inline_types(igvn);
3074 
3075   adjust_flat_array_access_aliases(igvn);
3076 
3077   if (failing())  return;
3078 
3079   if (C->macro_count() > 0) {
3080     // Eliminate some macro nodes before EA to reduce analysis pressure
3081     PhaseMacroExpand mexp(igvn);
3082     mexp.eliminate_macro_nodes(/* eliminate_locks= */ false);
3083     if (failing()) {
3084       return;
3085     }
3086     igvn.set_delay_transform(false);
3087     print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
3088   }
3089 
3090   _print_phase_loop_opts = has_loops();
3091   if (_print_phase_loop_opts) {
3092     print_method(PHASE_BEFORE_LOOP_OPTS, 2);
3093   }
3094 
3095   // Perform escape analysis
3096   if (do_escape_analysis() && ConnectionGraph::has_candidates(this)) {
3097     if (has_loops()) {
3098       // Cleanup graph (remove dead nodes).
3099       TracePhase tp(_t_idealLoop);
3100       PhaseIdealLoop::optimize(igvn, LoopOptsMaxUnroll);
3101       if (failing()) {
3102         return;
3103       }
3104       print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
3105       if (C->macro_count() > 0) {
3106         // Eliminate some macro nodes before EA to reduce analysis pressure
3107         PhaseMacroExpand mexp(igvn);
3108         mexp.eliminate_macro_nodes(/* eliminate_locks= */ false);
3109         if (failing()) {
3110           return;
3111         }
3112         igvn.set_delay_transform(false);
3113         print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
3114       }
3115     }
3116 
3117     bool progress;
3118     do {
3119       ConnectionGraph::do_analysis(this, &igvn);
3120 
3121       if (failing())  return;
3122 
3123       int mcount = macro_count(); // Record number of allocations and locks before IGVN
3124 
3125       // Optimize out fields loads from scalar replaceable allocations.
3126       igvn.optimize(true);
3127       print_method(PHASE_ITER_GVN_AFTER_EA, 2);
3128 
3129       if (failing()) return;
3130 
3131       if (congraph() != nullptr && macro_count() > 0) {
3132         TracePhase tp(_t_macroEliminate);
3133         PhaseMacroExpand mexp(igvn);
3134         mexp.eliminate_macro_nodes();
3135         if (failing()) {
3136           return;
3137         }
3138         print_method(PHASE_AFTER_MACRO_ELIMINATION, 2);
3139 
3140         igvn.set_delay_transform(false);
3141         print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
3142       }
3143 
3144       ConnectionGraph::verify_ram_nodes(this, root());
3145       if (failing())  return;
3146 
3147       progress = do_iterative_escape_analysis() &&
3148                  (macro_count() < mcount) &&
3149                  ConnectionGraph::has_candidates(this);
3150       // Try again if candidates exist and made progress
3151       // by removing some allocations and/or locks.
3152     } while (progress);
3153   }
3154 
3155   process_flat_accesses(igvn);
3156   if (failing()) {
3157     return;
3158   }
3159 
3160   // Loop transforms on the ideal graph.  Range Check Elimination,
3161   // peeling, unrolling, etc.
3162 
3163   // Set loop opts counter
3164   if((_loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
3165     {
3166       TracePhase tp(_t_idealLoop);
3167       PhaseIdealLoop::optimize(igvn, LoopOptsDefault);
3168       _loop_opts_cnt--;
3169       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP1, 2);
3170       if (failing())  return;
3171     }
3172     // Loop opts pass if partial peeling occurred in previous pass
3173     if(PartialPeelLoop && major_progress() && (_loop_opts_cnt > 0)) {
3174       TracePhase tp(_t_idealLoop);
3175       PhaseIdealLoop::optimize(igvn, LoopOptsSkipSplitIf);
3176       _loop_opts_cnt--;
3177       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP2, 2);
3178       if (failing())  return;
3179     }
3180     // Loop opts pass for loop-unrolling before CCP
3181     if(major_progress() && (_loop_opts_cnt > 0)) {
3182       TracePhase tp(_t_idealLoop);
3183       PhaseIdealLoop::optimize(igvn, LoopOptsSkipSplitIf);
3184       _loop_opts_cnt--;
3185       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP3, 2);
3186     }
3187     if (!failing()) {
3188       // Verify that last round of loop opts produced a valid graph
3189       PhaseIdealLoop::verify(igvn);
3190     }
3191   }
3192   if (failing())  return;
3193 
3194   // Conditional Constant Propagation;
3195   print_method(PHASE_BEFORE_CCP1, 2);
3196   PhaseCCP ccp( &igvn );
3197   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
3198   {
3199     TracePhase tp(_t_ccp);
3200     ccp.do_transform();
3201   }
3202   print_method(PHASE_CCP1, 2);
3203 
3204   assert( true, "Break here to ccp.dump_old2new_map()");
3205 
3206   // Iterative Global Value Numbering, including ideal transforms
3207   {
3208     TracePhase tp(_t_iterGVN2);
3209     igvn.reset_from_igvn(&ccp);
3210     igvn.optimize(true);
3211   }
3212   print_method(PHASE_ITER_GVN2, 2);
3213 
3214   if (failing())  return;
3215 
3216   // Loop transforms on the ideal graph.  Range Check Elimination,
3217   // peeling, unrolling, etc.
3218   if (!optimize_loops(igvn, LoopOptsDefault)) {
3219     return;
3220   }
3221 
3222   if (failing())  return;
3223 
3224   C->clear_major_progress(); // ensure that major progress is now clear
3225 
3226   process_for_post_loop_opts_igvn(igvn);
3227 
3228   process_for_merge_stores_igvn(igvn);
3229 
3230   if (failing())  return;
3231 
3232 #ifdef ASSERT
3233   bs->verify_gc_barriers(this, BarrierSetC2::BeforeMacroExpand);
3234 #endif
3235 
3236   assert(_late_inlines.length() == 0 || IncrementalInlineMH || IncrementalInlineVirtual, "not empty");
3237 
3238   if (_late_inlines.length() > 0) {
3239     // More opportunities to optimize virtual and MH calls.
3240     // Though it's maybe too late to perform inlining, strength-reducing them to direct calls is still an option.
3241     process_late_inline_calls_no_inline(igvn);
3242     process_inline_types(igvn);
3243   }
3244 
3245   {
3246     TracePhase tp(_t_macroExpand);
3247     PhaseMacroExpand mex(igvn);
3248     // Last attempt to eliminate macro nodes.
3249     mex.eliminate_macro_nodes();
3250     if (failing()) {
3251       return;
3252     }
3253 
3254     print_method(PHASE_BEFORE_MACRO_EXPANSION, 3);
3255     // Do not allow new macro nodes once we start to eliminate and expand
3256     C->reset_allow_macro_nodes();
3257     // Last attempt to eliminate macro nodes before expand
3258     mex.eliminate_macro_nodes();
3259     if (failing()) {
3260       return;
3261     }
3262     mex.eliminate_opaque_looplimit_macro_nodes();
3263     if (failing()) {
3264       return;
3265     }
3266     print_method(PHASE_AFTER_MACRO_ELIMINATION, 2);
3267     if (mex.expand_macro_nodes()) {
3268       assert(failing(), "must bail out w/ explicit message");
3269       return;
3270     }
3271     print_method(PHASE_AFTER_MACRO_EXPANSION, 2);
3272   }
3273 
3274   // Process inline type nodes again and remove them. From here
3275   // on we don't need to keep track of field values anymore.
3276   process_inline_types(igvn, /* remove= */ true);
3277 
3278   {
3279     TracePhase tp(_t_barrierExpand);
3280     if (bs->expand_barriers(this, igvn)) {
3281       assert(failing(), "must bail out w/ explicit message");
3282       return;
3283     }
3284     print_method(PHASE_BARRIER_EXPANSION, 2);
3285   }
3286 
3287   if (C->max_vector_size() > 0) {
3288     C->optimize_logic_cones(igvn);
3289     igvn.optimize();
3290     if (failing()) return;
3291   }
3292 
3293   DEBUG_ONLY( _modified_nodes = nullptr; )
3294   DEBUG_ONLY( _late_inlines.clear(); )
3295 
3296   assert(igvn._worklist.size() == 0, "not empty");
3297  } // (End scope of igvn; run destructor if necessary for asserts.)
3298 
3299  check_no_dead_use();
3300 
3301  // We will never use the NodeHash table any more. Clear it so that final_graph_reshaping does not have
3302  // to remove hashes to unlock nodes for modifications.
3303  C->node_hash()->clear();
3304 
3305  // A method with only infinite loops has no edges entering loops from root
3306  {
3307    TracePhase tp(_t_graphReshaping);
3308    if (final_graph_reshaping()) {
3309      assert(failing(), "must bail out w/ explicit message");
3310      return;
3311    }
3312  }
3313 
3314  print_method(PHASE_OPTIMIZE_FINISHED, 2);
3315  DEBUG_ONLY(set_phase_optimize_finished();)
3316 }
3317 
3318 #ifdef ASSERT
3319 void Compile::check_no_dead_use() const {
3320   ResourceMark rm;
3321   Unique_Node_List wq;
3322   wq.push(root());
3323   for (uint i = 0; i < wq.size(); ++i) {
3324     Node* n = wq.at(i);
3325     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
3326       Node* u = n->fast_out(j);
3327       if (u->outcnt() == 0 && !u->is_Con()) {
3328         u->dump();
3329         fatal("no reachable node should have no use");
3330       }
3331       wq.push(u);
3332     }
3333   }
3334 }
3335 #endif
3336 
3337 void Compile::inline_vector_reboxing_calls() {
3338   if (C->_vector_reboxing_late_inlines.length() > 0) {
3339     _late_inlines_pos = C->_late_inlines.length();
3340     while (_vector_reboxing_late_inlines.length() > 0) {
3341       CallGenerator* cg = _vector_reboxing_late_inlines.pop();
3342       cg->do_late_inline();
3343       if (failing())  return;
3344       print_method(PHASE_INLINE_VECTOR_REBOX, 3, cg->call_node());
3345     }
3346     _vector_reboxing_late_inlines.trunc_to(0);
3347   }
3348 }
3349 
3350 bool Compile::has_vbox_nodes() {
3351   if (C->_vector_reboxing_late_inlines.length() > 0) {
3352     return true;
3353   }
3354   for (int macro_idx = C->macro_count() - 1; macro_idx >= 0; macro_idx--) {
3355     Node * n = C->macro_node(macro_idx);
3356     assert(n->is_macro(), "only macro nodes expected here");
3357     if (n->Opcode() == Op_VectorUnbox || n->Opcode() == Op_VectorBox || n->Opcode() == Op_VectorBoxAllocate) {
3358       return true;
3359     }
3360   }
3361   return false;
3362 }
3363 
3364 //---------------------------- Bitwise operation packing optimization ---------------------------
3365 
3366 static bool is_vector_unary_bitwise_op(Node* n) {
3367   return n->Opcode() == Op_XorV &&
3368          VectorNode::is_vector_bitwise_not_pattern(n);
3369 }
3370 
3371 static bool is_vector_binary_bitwise_op(Node* n) {
3372   switch (n->Opcode()) {
3373     case Op_AndV:
3374     case Op_OrV:
3375       return true;
3376 
3377     case Op_XorV:
3378       return !is_vector_unary_bitwise_op(n);
3379 
3380     default:
3381       return false;
3382   }
3383 }
3384 
3385 static bool is_vector_ternary_bitwise_op(Node* n) {
3386   return n->Opcode() == Op_MacroLogicV;
3387 }
3388 
3389 static bool is_vector_bitwise_op(Node* n) {
3390   return is_vector_unary_bitwise_op(n)  ||
3391          is_vector_binary_bitwise_op(n) ||
3392          is_vector_ternary_bitwise_op(n);
3393 }
3394 
3395 static bool is_vector_bitwise_cone_root(Node* n) {
3396   if (n->bottom_type()->isa_vectmask() || !is_vector_bitwise_op(n)) {
3397     return false;
3398   }
3399   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3400     if (is_vector_bitwise_op(n->fast_out(i))) {
3401       return false;
3402     }
3403   }
3404   return true;
3405 }
3406 
3407 static uint collect_unique_inputs(Node* n, Unique_Node_List& inputs) {
3408   uint cnt = 0;
3409   if (is_vector_bitwise_op(n)) {
3410     uint inp_cnt = n->is_predicated_vector() ? n->req()-1 : n->req();
3411     if (VectorNode::is_vector_bitwise_not_pattern(n)) {
3412       for (uint i = 1; i < inp_cnt; i++) {
3413         Node* in = n->in(i);
3414         bool skip = VectorNode::is_all_ones_vector(in);
3415         if (!skip && !inputs.member(in)) {
3416           inputs.push(in);
3417           cnt++;
3418         }
3419       }
3420       assert(cnt <= 1, "not unary");
3421     } else {
3422       uint last_req = inp_cnt;
3423       if (is_vector_ternary_bitwise_op(n)) {
3424         last_req = inp_cnt - 1; // skip last input
3425       }
3426       for (uint i = 1; i < last_req; i++) {
3427         Node* def = n->in(i);
3428         if (!inputs.member(def)) {
3429           inputs.push(def);
3430           cnt++;
3431         }
3432       }
3433     }
3434   } else { // not a bitwise operations
3435     if (!inputs.member(n)) {
3436       inputs.push(n);
3437       cnt++;
3438     }
3439   }
3440   return cnt;
3441 }
3442 
3443 void Compile::collect_logic_cone_roots(Unique_Node_List& list) {
3444   Unique_Node_List useful_nodes;
3445   C->identify_useful_nodes(useful_nodes);
3446 
3447   for (uint i = 0; i < useful_nodes.size(); i++) {
3448     Node* n = useful_nodes.at(i);
3449     if (is_vector_bitwise_cone_root(n)) {
3450       list.push(n);
3451     }
3452   }
3453 }
3454 
3455 Node* Compile::xform_to_MacroLogicV(PhaseIterGVN& igvn,
3456                                     const TypeVect* vt,
3457                                     Unique_Node_List& partition,
3458                                     Unique_Node_List& inputs) {
3459   assert(partition.size() == 2 || partition.size() == 3, "not supported");
3460   assert(inputs.size()    == 2 || inputs.size()    == 3, "not supported");
3461   assert(Matcher::match_rule_supported_vector(Op_MacroLogicV, vt->length(), vt->element_basic_type()), "not supported");
3462 
3463   Node* in1 = inputs.at(0);
3464   Node* in2 = inputs.at(1);
3465   Node* in3 = (inputs.size() == 3 ? inputs.at(2) : in2);
3466 
3467   uint func = compute_truth_table(partition, inputs);
3468 
3469   Node* pn = partition.at(partition.size() - 1);
3470   Node* mask = pn->is_predicated_vector() ? pn->in(pn->req()-1) : nullptr;
3471   return igvn.transform(MacroLogicVNode::make(igvn, in1, in2, in3, mask, func, vt));
3472 }
3473 
3474 static uint extract_bit(uint func, uint pos) {
3475   return (func & (1 << pos)) >> pos;
3476 }
3477 
3478 //
3479 //  A macro logic node represents a truth table. It has 4 inputs,
3480 //  First three inputs corresponds to 3 columns of a truth table
3481 //  and fourth input captures the logic function.
3482 //
3483 //  eg.  fn = (in1 AND in2) OR in3;
3484 //
3485 //      MacroNode(in1,in2,in3,fn)
3486 //
3487 //  -----------------
3488 //  in1 in2 in3  fn
3489 //  -----------------
3490 //  0    0   0    0
3491 //  0    0   1    1
3492 //  0    1   0    0
3493 //  0    1   1    1
3494 //  1    0   0    0
3495 //  1    0   1    1
3496 //  1    1   0    1
3497 //  1    1   1    1
3498 //
3499 
3500 uint Compile::eval_macro_logic_op(uint func, uint in1 , uint in2, uint in3) {
3501   int res = 0;
3502   for (int i = 0; i < 8; i++) {
3503     int bit1 = extract_bit(in1, i);
3504     int bit2 = extract_bit(in2, i);
3505     int bit3 = extract_bit(in3, i);
3506 
3507     int func_bit_pos = (bit1 << 2 | bit2 << 1 | bit3);
3508     int func_bit = extract_bit(func, func_bit_pos);
3509 
3510     res |= func_bit << i;
3511   }
3512   return res;
3513 }
3514 
3515 static uint eval_operand(Node* n, HashTable<Node*,uint>& eval_map) {
3516   assert(n != nullptr, "");
3517   assert(eval_map.contains(n), "absent");
3518   return *(eval_map.get(n));
3519 }
3520 
3521 static void eval_operands(Node* n,
3522                           uint& func1, uint& func2, uint& func3,
3523                           HashTable<Node*,uint>& eval_map) {
3524   assert(is_vector_bitwise_op(n), "");
3525 
3526   if (is_vector_unary_bitwise_op(n)) {
3527     Node* opnd = n->in(1);
3528     if (VectorNode::is_vector_bitwise_not_pattern(n) && VectorNode::is_all_ones_vector(opnd)) {
3529       opnd = n->in(2);
3530     }
3531     func1 = eval_operand(opnd, eval_map);
3532   } else if (is_vector_binary_bitwise_op(n)) {
3533     func1 = eval_operand(n->in(1), eval_map);
3534     func2 = eval_operand(n->in(2), eval_map);
3535   } else {
3536     assert(is_vector_ternary_bitwise_op(n), "unknown operation");
3537     func1 = eval_operand(n->in(1), eval_map);
3538     func2 = eval_operand(n->in(2), eval_map);
3539     func3 = eval_operand(n->in(3), eval_map);
3540   }
3541 }
3542 
3543 uint Compile::compute_truth_table(Unique_Node_List& partition, Unique_Node_List& inputs) {
3544   assert(inputs.size() <= 3, "sanity");
3545   ResourceMark rm;
3546   uint res = 0;
3547   HashTable<Node*,uint> eval_map;
3548 
3549   // Populate precomputed functions for inputs.
3550   // Each input corresponds to one column of 3 input truth-table.
3551   uint input_funcs[] = { 0xAA,   // (_, _, c) -> c
3552                          0xCC,   // (_, b, _) -> b
3553                          0xF0 }; // (a, _, _) -> a
3554   for (uint i = 0; i < inputs.size(); i++) {
3555     eval_map.put(inputs.at(i), input_funcs[2-i]);
3556   }
3557 
3558   for (uint i = 0; i < partition.size(); i++) {
3559     Node* n = partition.at(i);
3560 
3561     uint func1 = 0, func2 = 0, func3 = 0;
3562     eval_operands(n, func1, func2, func3, eval_map);
3563 
3564     switch (n->Opcode()) {
3565       case Op_OrV:
3566         assert(func3 == 0, "not binary");
3567         res = func1 | func2;
3568         break;
3569       case Op_AndV:
3570         assert(func3 == 0, "not binary");
3571         res = func1 & func2;
3572         break;
3573       case Op_XorV:
3574         if (VectorNode::is_vector_bitwise_not_pattern(n)) {
3575           assert(func2 == 0 && func3 == 0, "not unary");
3576           res = (~func1) & 0xFF;
3577         } else {
3578           assert(func3 == 0, "not binary");
3579           res = func1 ^ func2;
3580         }
3581         break;
3582       case Op_MacroLogicV:
3583         // Ordering of inputs may change during evaluation of sub-tree
3584         // containing MacroLogic node as a child node, thus a re-evaluation
3585         // makes sure that function is evaluated in context of current
3586         // inputs.
3587         res = eval_macro_logic_op(n->in(4)->get_int(), func1, func2, func3);
3588         break;
3589 
3590       default: assert(false, "not supported: %s", n->Name());
3591     }
3592     assert(res <= 0xFF, "invalid");
3593     eval_map.put(n, res);
3594   }
3595   return res;
3596 }
3597 
3598 // Criteria under which nodes gets packed into a macro logic node:-
3599 //  1) Parent and both child nodes are all unmasked or masked with
3600 //     same predicates.
3601 //  2) Masked parent can be packed with left child if it is predicated
3602 //     and both have same predicates.
3603 //  3) Masked parent can be packed with right child if its un-predicated
3604 //     or has matching predication condition.
3605 //  4) An unmasked parent can be packed with an unmasked child.
3606 bool Compile::compute_logic_cone(Node* n, Unique_Node_List& partition, Unique_Node_List& inputs) {
3607   assert(partition.size() == 0, "not empty");
3608   assert(inputs.size() == 0, "not empty");
3609   if (is_vector_ternary_bitwise_op(n)) {
3610     return false;
3611   }
3612 
3613   bool is_unary_op = is_vector_unary_bitwise_op(n);
3614   if (is_unary_op) {
3615     assert(collect_unique_inputs(n, inputs) == 1, "not unary");
3616     return false; // too few inputs
3617   }
3618 
3619   bool pack_left_child = true;
3620   bool pack_right_child = true;
3621 
3622   bool left_child_LOP = is_vector_bitwise_op(n->in(1));
3623   bool right_child_LOP = is_vector_bitwise_op(n->in(2));
3624 
3625   int left_child_input_cnt = 0;
3626   int right_child_input_cnt = 0;
3627 
3628   bool parent_is_predicated = n->is_predicated_vector();
3629   bool left_child_predicated = n->in(1)->is_predicated_vector();
3630   bool right_child_predicated = n->in(2)->is_predicated_vector();
3631 
3632   Node* parent_pred = parent_is_predicated ? n->in(n->req()-1) : nullptr;
3633   Node* left_child_pred = left_child_predicated ? n->in(1)->in(n->in(1)->req()-1) : nullptr;
3634   Node* right_child_pred = right_child_predicated ? n->in(1)->in(n->in(1)->req()-1) : nullptr;
3635 
3636   do {
3637     if (pack_left_child && left_child_LOP &&
3638         ((!parent_is_predicated && !left_child_predicated) ||
3639         ((parent_is_predicated && left_child_predicated &&
3640           parent_pred == left_child_pred)))) {
3641        partition.push(n->in(1));
3642        left_child_input_cnt = collect_unique_inputs(n->in(1), inputs);
3643     } else {
3644        inputs.push(n->in(1));
3645        left_child_input_cnt = 1;
3646     }
3647 
3648     if (pack_right_child && right_child_LOP &&
3649         (!right_child_predicated ||
3650          (right_child_predicated && parent_is_predicated &&
3651           parent_pred == right_child_pred))) {
3652        partition.push(n->in(2));
3653        right_child_input_cnt = collect_unique_inputs(n->in(2), inputs);
3654     } else {
3655        inputs.push(n->in(2));
3656        right_child_input_cnt = 1;
3657     }
3658 
3659     if (inputs.size() > 3) {
3660       assert(partition.size() > 0, "");
3661       inputs.clear();
3662       partition.clear();
3663       if (left_child_input_cnt > right_child_input_cnt) {
3664         pack_left_child = false;
3665       } else {
3666         pack_right_child = false;
3667       }
3668     } else {
3669       break;
3670     }
3671   } while(true);
3672 
3673   if(partition.size()) {
3674     partition.push(n);
3675   }
3676 
3677   return (partition.size() == 2 || partition.size() == 3) &&
3678          (inputs.size()    == 2 || inputs.size()    == 3);
3679 }
3680 
3681 void Compile::process_logic_cone_root(PhaseIterGVN &igvn, Node *n, VectorSet &visited) {
3682   assert(is_vector_bitwise_op(n), "not a root");
3683 
3684   visited.set(n->_idx);
3685 
3686   // 1) Do a DFS walk over the logic cone.
3687   for (uint i = 1; i < n->req(); i++) {
3688     Node* in = n->in(i);
3689     if (!visited.test(in->_idx) && is_vector_bitwise_op(in)) {
3690       process_logic_cone_root(igvn, in, visited);
3691     }
3692   }
3693 
3694   // 2) Bottom up traversal: Merge node[s] with
3695   // the parent to form macro logic node.
3696   Unique_Node_List partition;
3697   Unique_Node_List inputs;
3698   if (compute_logic_cone(n, partition, inputs)) {
3699     const TypeVect* vt = n->bottom_type()->is_vect();
3700     Node* pn = partition.at(partition.size() - 1);
3701     Node* mask = pn->is_predicated_vector() ? pn->in(pn->req()-1) : nullptr;
3702     if (mask == nullptr ||
3703         Matcher::match_rule_supported_vector_masked(Op_MacroLogicV, vt->length(), vt->element_basic_type())) {
3704       Node* macro_logic = xform_to_MacroLogicV(igvn, vt, partition, inputs);
3705       VectorNode::trace_new_vector(macro_logic, "MacroLogic");
3706       igvn.replace_node(n, macro_logic);
3707     }
3708   }
3709 }
3710 
3711 void Compile::optimize_logic_cones(PhaseIterGVN &igvn) {
3712   ResourceMark rm;
3713   if (Matcher::match_rule_supported(Op_MacroLogicV)) {
3714     Unique_Node_List list;
3715     collect_logic_cone_roots(list);
3716 
3717     while (list.size() > 0) {
3718       Node* n = list.pop();
3719       const TypeVect* vt = n->bottom_type()->is_vect();
3720       bool supported = Matcher::match_rule_supported_vector(Op_MacroLogicV, vt->length(), vt->element_basic_type());
3721       if (supported) {
3722         VectorSet visited(comp_arena());
3723         process_logic_cone_root(igvn, n, visited);
3724       }
3725     }
3726   }
3727 }
3728 
3729 //------------------------------Code_Gen---------------------------------------
3730 // Given a graph, generate code for it
3731 void Compile::Code_Gen() {
3732   if (failing()) {
3733     return;
3734   }
3735 
3736   // Perform instruction selection.  You might think we could reclaim Matcher
3737   // memory PDQ, but actually the Matcher is used in generating spill code.
3738   // Internals of the Matcher (including some VectorSets) must remain live
3739   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
3740   // set a bit in reclaimed memory.
3741 
3742   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
3743   // nodes.  Mapping is only valid at the root of each matched subtree.
3744   NOT_PRODUCT( verify_graph_edges(); )
3745 
3746   Matcher matcher;
3747   _matcher = &matcher;
3748   {
3749     TracePhase tp(_t_matcher);
3750     matcher.match();
3751     if (failing()) {
3752       return;
3753     }
3754   }
3755   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
3756   // nodes.  Mapping is only valid at the root of each matched subtree.
3757   NOT_PRODUCT( verify_graph_edges(); )
3758 
3759   // If you have too many nodes, or if matching has failed, bail out
3760   check_node_count(0, "out of nodes matching instructions");
3761   if (failing()) {
3762     return;
3763   }
3764 
3765   print_method(PHASE_MATCHING, 2);
3766 
3767   // Build a proper-looking CFG
3768   PhaseCFG cfg(node_arena(), root(), matcher);
3769   if (failing()) {
3770     return;
3771   }
3772   _cfg = &cfg;
3773   {
3774     TracePhase tp(_t_scheduler);
3775     bool success = cfg.do_global_code_motion();
3776     if (!success) {
3777       return;
3778     }
3779 
3780     print_method(PHASE_GLOBAL_CODE_MOTION, 2);
3781     NOT_PRODUCT( verify_graph_edges(); )
3782     cfg.verify();
3783     if (failing()) {
3784       return;
3785     }
3786   }
3787 
3788   PhaseChaitin regalloc(unique(), cfg, matcher, false);
3789   _regalloc = &regalloc;
3790   {
3791     TracePhase tp(_t_registerAllocation);
3792     // Perform register allocation.  After Chaitin, use-def chains are
3793     // no longer accurate (at spill code) and so must be ignored.
3794     // Node->LRG->reg mappings are still accurate.
3795     _regalloc->Register_Allocate();
3796 
3797     // Bail out if the allocator builds too many nodes
3798     if (failing()) {
3799       return;
3800     }
3801 
3802     print_method(PHASE_REGISTER_ALLOCATION, 2);
3803   }
3804 
3805   // Prior to register allocation we kept empty basic blocks in case the
3806   // the allocator needed a place to spill.  After register allocation we
3807   // are not adding any new instructions.  If any basic block is empty, we
3808   // can now safely remove it.
3809   {
3810     TracePhase tp(_t_blockOrdering);
3811     cfg.remove_empty_blocks();
3812     if (do_freq_based_layout()) {
3813       PhaseBlockLayout layout(cfg);
3814     } else {
3815       cfg.set_loop_alignment();
3816     }
3817     cfg.fixup_flow();
3818     cfg.remove_unreachable_blocks();
3819     cfg.verify_dominator_tree();
3820     print_method(PHASE_BLOCK_ORDERING, 3);
3821   }
3822 
3823   // Apply peephole optimizations
3824   if( OptoPeephole ) {
3825     TracePhase tp(_t_peephole);
3826     PhasePeephole peep( _regalloc, cfg);
3827     peep.do_transform();
3828     print_method(PHASE_PEEPHOLE, 3);
3829   }
3830 
3831   // Do late expand if CPU requires this.
3832   if (Matcher::require_postalloc_expand) {
3833     TracePhase tp(_t_postalloc_expand);
3834     cfg.postalloc_expand(_regalloc);
3835     print_method(PHASE_POSTALLOC_EXPAND, 3);
3836   }
3837 
3838 #ifdef ASSERT
3839   {
3840     CompilationMemoryStatistic::do_test_allocations();
3841     if (failing()) return;
3842   }
3843 #endif
3844 
3845   // Convert Nodes to instruction bits in a buffer
3846   {
3847     TracePhase tp(_t_output);
3848     PhaseOutput output;
3849     output.Output();
3850     if (failing())  return;
3851     output.install();
3852     print_method(PHASE_FINAL_CODE, 1); // Compile::_output is not null here
3853   }
3854 
3855   // He's dead, Jim.
3856   _cfg     = (PhaseCFG*)((intptr_t)0xdeadbeef);
3857   _regalloc = (PhaseChaitin*)((intptr_t)0xdeadbeef);
3858 }
3859 
3860 //------------------------------Final_Reshape_Counts---------------------------
3861 // This class defines counters to help identify when a method
3862 // may/must be executed using hardware with only 24-bit precision.
3863 struct Final_Reshape_Counts : public StackObj {
3864   int  _call_count;             // count non-inlined 'common' calls
3865   int  _float_count;            // count float ops requiring 24-bit precision
3866   int  _double_count;           // count double ops requiring more precision
3867   int  _java_call_count;        // count non-inlined 'java' calls
3868   int  _inner_loop_count;       // count loops which need alignment
3869   VectorSet _visited;           // Visitation flags
3870   Node_List _tests;             // Set of IfNodes & PCTableNodes
3871 
3872   Final_Reshape_Counts() :
3873     _call_count(0), _float_count(0), _double_count(0),
3874     _java_call_count(0), _inner_loop_count(0) { }
3875 
3876   void inc_call_count  () { _call_count  ++; }
3877   void inc_float_count () { _float_count ++; }
3878   void inc_double_count() { _double_count++; }
3879   void inc_java_call_count() { _java_call_count++; }
3880   void inc_inner_loop_count() { _inner_loop_count++; }
3881 
3882   int  get_call_count  () const { return _call_count  ; }
3883   int  get_float_count () const { return _float_count ; }
3884   int  get_double_count() const { return _double_count; }
3885   int  get_java_call_count() const { return _java_call_count; }
3886   int  get_inner_loop_count() const { return _inner_loop_count; }
3887 };
3888 
3889 //------------------------------final_graph_reshaping_impl----------------------
3890 // Implement items 1-5 from final_graph_reshaping below.
3891 void Compile::final_graph_reshaping_impl(Node *n, Final_Reshape_Counts& frc, Unique_Node_List& dead_nodes) {
3892 
3893   if ( n->outcnt() == 0 ) return; // dead node
3894   uint nop = n->Opcode();
3895 
3896   // Check for 2-input instruction with "last use" on right input.
3897   // Swap to left input.  Implements item (2).
3898   if( n->req() == 3 &&          // two-input instruction
3899       n->in(1)->outcnt() > 1 && // left use is NOT a last use
3900       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
3901       n->in(2)->outcnt() == 1 &&// right use IS a last use
3902       !n->in(2)->is_Con() ) {   // right use is not a constant
3903     // Check for commutative opcode
3904     switch( nop ) {
3905     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddL:
3906     case Op_MaxI:  case Op_MaxL:  case Op_MaxF:  case Op_MaxD:
3907     case Op_MinI:  case Op_MinL:  case Op_MinF:  case Op_MinD:
3908     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulL:
3909     case Op_AndL:  case Op_XorL:  case Op_OrL:
3910     case Op_AndI:  case Op_XorI:  case Op_OrI: {
3911       // Move "last use" input to left by swapping inputs
3912       n->swap_edges(1, 2);
3913       break;
3914     }
3915     default:
3916       break;
3917     }
3918   }
3919 
3920 #ifdef ASSERT
3921   if( n->is_Mem() ) {
3922     int alias_idx = get_alias_index(n->as_Mem()->adr_type());
3923     assert( n->in(0) != nullptr || alias_idx != Compile::AliasIdxRaw ||
3924             // oop will be recorded in oop map if load crosses safepoint
3925             (n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
3926                               LoadNode::is_immutable_value(n->in(MemNode::Address)))),
3927             "raw memory operations should have control edge");
3928   }
3929   if (n->is_MemBar()) {
3930     MemBarNode* mb = n->as_MemBar();
3931     if (mb->trailing_store() || mb->trailing_load_store()) {
3932       assert(mb->leading_membar()->trailing_membar() == mb, "bad membar pair");
3933       Node* mem = BarrierSet::barrier_set()->barrier_set_c2()->step_over_gc_barrier(mb->in(MemBarNode::Precedent));
3934       assert((mb->trailing_store() && mem->is_Store() && mem->as_Store()->is_release()) ||
3935              (mb->trailing_load_store() && mem->is_LoadStore()), "missing mem op");
3936     } else if (mb->leading()) {
3937       assert(mb->trailing_membar()->leading_membar() == mb, "bad membar pair");
3938     }
3939   }
3940 #endif
3941   // Count FPU ops and common calls, implements item (3)
3942   bool gc_handled = BarrierSet::barrier_set()->barrier_set_c2()->final_graph_reshaping(this, n, nop, dead_nodes);
3943   if (!gc_handled) {
3944     final_graph_reshaping_main_switch(n, frc, nop, dead_nodes);
3945   }
3946 
3947   // Collect CFG split points
3948   if (n->is_MultiBranch() && !n->is_RangeCheck()) {
3949     frc._tests.push(n);
3950   }
3951 }
3952 
3953 void Compile::handle_div_mod_op(Node* n, BasicType bt, bool is_unsigned) {
3954   if (!UseDivMod) {
3955     return;
3956   }
3957 
3958   // Check if "a % b" and "a / b" both exist
3959   Node* d = n->find_similar(Op_DivIL(bt, is_unsigned));
3960   if (d == nullptr) {
3961     return;
3962   }
3963 
3964   // Replace them with a fused divmod if supported
3965   if (Matcher::has_match_rule(Op_DivModIL(bt, is_unsigned))) {
3966     DivModNode* divmod = DivModNode::make(n, bt, is_unsigned);
3967     // If the divisor input for a Div (or Mod etc.) is not zero, then the control input of the Div is set to zero.
3968     // It could be that the divisor input is found not zero because its type is narrowed down by a CastII in the
3969     // subgraph for that input. Range check CastIIs are removed during final graph reshape. To preserve the dependency
3970     // carried by a CastII, precedence edges are added to the Div node. We need to transfer the precedence edges to the
3971     // DivMod node so the dependency is not lost.
3972     divmod->add_prec_from(n);
3973     divmod->add_prec_from(d);
3974     d->subsume_by(divmod->div_proj(), this);
3975     n->subsume_by(divmod->mod_proj(), this);
3976   } else {
3977     // Replace "a % b" with "a - ((a / b) * b)"
3978     Node* mult = MulNode::make(d, d->in(2), bt);
3979     Node* sub = SubNode::make(d->in(1), mult, bt);
3980     n->subsume_by(sub, this);
3981   }
3982 }
3983 
3984 void Compile::final_graph_reshaping_main_switch(Node* n, Final_Reshape_Counts& frc, uint nop, Unique_Node_List& dead_nodes) {
3985   switch( nop ) {
3986   // Count all float operations that may use FPU
3987   case Op_AddF:
3988   case Op_SubF:
3989   case Op_MulF:
3990   case Op_DivF:
3991   case Op_NegF:
3992   case Op_ModF:
3993   case Op_ConvI2F:
3994   case Op_ConF:
3995   case Op_CmpF:
3996   case Op_CmpF3:
3997   case Op_StoreF:
3998   case Op_LoadF:
3999   // case Op_ConvL2F: // longs are split into 32-bit halves
4000     frc.inc_float_count();
4001     break;
4002 
4003   case Op_ConvF2D:
4004   case Op_ConvD2F:
4005     frc.inc_float_count();
4006     frc.inc_double_count();
4007     break;
4008 
4009   // Count all double operations that may use FPU
4010   case Op_AddD:
4011   case Op_SubD:
4012   case Op_MulD:
4013   case Op_DivD:
4014   case Op_NegD:
4015   case Op_ModD:
4016   case Op_ConvI2D:
4017   case Op_ConvD2I:
4018   // case Op_ConvL2D: // handled by leaf call
4019   // case Op_ConvD2L: // handled by leaf call
4020   case Op_ConD:
4021   case Op_CmpD:
4022   case Op_CmpD3:
4023   case Op_StoreD:
4024   case Op_LoadD:
4025   case Op_LoadD_unaligned:
4026     frc.inc_double_count();
4027     break;
4028   case Op_Opaque1:              // Remove Opaque Nodes before matching
4029     n->subsume_by(n->in(1), this);
4030     break;
4031   case Op_CallLeafPure: {
4032     // If the pure call is not supported, then lower to a CallLeaf.
4033     if (!Matcher::match_rule_supported(Op_CallLeafPure)) {
4034       CallNode* call = n->as_Call();
4035       CallNode* new_call = new CallLeafNode(call->tf(), call->entry_point(),
4036                                             call->_name, TypeRawPtr::BOTTOM);
4037       new_call->init_req(TypeFunc::Control, call->in(TypeFunc::Control));
4038       new_call->init_req(TypeFunc::I_O, C->top());
4039       new_call->init_req(TypeFunc::Memory, C->top());
4040       new_call->init_req(TypeFunc::ReturnAdr, C->top());
4041       new_call->init_req(TypeFunc::FramePtr, C->top());
4042       for (unsigned int i = TypeFunc::Parms; i < call->tf()->domain_sig()->cnt(); i++) {
4043         new_call->init_req(i, call->in(i));
4044       }
4045       n->subsume_by(new_call, this);
4046     }
4047     frc.inc_call_count();
4048     break;
4049   }
4050   case Op_CallStaticJava:
4051   case Op_CallJava:
4052   case Op_CallDynamicJava:
4053     frc.inc_java_call_count(); // Count java call site;
4054   case Op_CallRuntime:
4055   case Op_CallLeaf:
4056   case Op_CallLeafVector:
4057   case Op_CallLeafNoFP: {
4058     assert (n->is_Call(), "");
4059     CallNode *call = n->as_Call();
4060     // Count call sites where the FP mode bit would have to be flipped.
4061     // Do not count uncommon runtime calls:
4062     // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
4063     // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
4064     if (!call->is_CallStaticJava() || !call->as_CallStaticJava()->_name) {
4065       frc.inc_call_count();   // Count the call site
4066     } else {                  // See if uncommon argument is shared
4067       Node *n = call->in(TypeFunc::Parms);
4068       int nop = n->Opcode();
4069       // Clone shared simple arguments to uncommon calls, item (1).
4070       if (n->outcnt() > 1 &&
4071           !n->is_Proj() &&
4072           nop != Op_CreateEx &&
4073           nop != Op_CheckCastPP &&
4074           nop != Op_DecodeN &&
4075           nop != Op_DecodeNKlass &&
4076           !n->is_Mem() &&
4077           !n->is_Phi()) {
4078         Node *x = n->clone();
4079         call->set_req(TypeFunc::Parms, x);
4080       }
4081     }
4082     break;
4083   }
4084   case Op_StoreB:
4085   case Op_StoreC:
4086   case Op_StoreI:
4087   case Op_StoreL:
4088   case Op_StoreLSpecial:
4089   case Op_CompareAndSwapB:
4090   case Op_CompareAndSwapS:
4091   case Op_CompareAndSwapI:
4092   case Op_CompareAndSwapL:
4093   case Op_CompareAndSwapP:
4094   case Op_CompareAndSwapN:
4095   case Op_WeakCompareAndSwapB:
4096   case Op_WeakCompareAndSwapS:
4097   case Op_WeakCompareAndSwapI:
4098   case Op_WeakCompareAndSwapL:
4099   case Op_WeakCompareAndSwapP:
4100   case Op_WeakCompareAndSwapN:
4101   case Op_CompareAndExchangeB:
4102   case Op_CompareAndExchangeS:
4103   case Op_CompareAndExchangeI:
4104   case Op_CompareAndExchangeL:
4105   case Op_CompareAndExchangeP:
4106   case Op_CompareAndExchangeN:
4107   case Op_GetAndAddS:
4108   case Op_GetAndAddB:
4109   case Op_GetAndAddI:
4110   case Op_GetAndAddL:
4111   case Op_GetAndSetS:
4112   case Op_GetAndSetB:
4113   case Op_GetAndSetI:
4114   case Op_GetAndSetL:
4115   case Op_GetAndSetP:
4116   case Op_GetAndSetN:
4117   case Op_StoreP:
4118   case Op_StoreN:
4119   case Op_StoreNKlass:
4120   case Op_LoadB:
4121   case Op_LoadUB:
4122   case Op_LoadUS:
4123   case Op_LoadI:
4124   case Op_LoadKlass:
4125   case Op_LoadNKlass:
4126   case Op_LoadL:
4127   case Op_LoadL_unaligned:
4128   case Op_LoadP:
4129   case Op_LoadN:
4130   case Op_LoadRange:
4131   case Op_LoadS:
4132     break;
4133 
4134   case Op_AddP: {               // Assert sane base pointers
4135     Node *addp = n->in(AddPNode::Address);
4136     assert(n->as_AddP()->address_input_has_same_base(), "Base pointers must match (addp %u)", addp->_idx );
4137 #ifdef _LP64
4138     if (addp->Opcode() == Op_ConP &&
4139         addp == n->in(AddPNode::Base) &&
4140         n->in(AddPNode::Offset)->is_Con()) {
4141       // If the transformation of ConP to ConN+DecodeN is beneficial depends
4142       // on the platform and on the compressed oops mode.
4143       // Use addressing with narrow klass to load with offset on x86.
4144       // Some platforms can use the constant pool to load ConP.
4145       // Do this transformation here since IGVN will convert ConN back to ConP.
4146       const Type* t = addp->bottom_type();
4147       bool is_oop   = t->isa_oopptr() != nullptr;
4148       bool is_klass = t->isa_klassptr() != nullptr;
4149 
4150       if ((is_oop   && UseCompressedOops          && Matcher::const_oop_prefer_decode()  ) ||
4151           (is_klass && Matcher::const_klass_prefer_decode() &&
4152            t->isa_klassptr()->exact_klass()->is_in_encoding_range())) {
4153         Node* nn = nullptr;
4154 
4155         int op = is_oop ? Op_ConN : Op_ConNKlass;
4156 
4157         // Look for existing ConN node of the same exact type.
4158         Node* r  = root();
4159         uint cnt = r->outcnt();
4160         for (uint i = 0; i < cnt; i++) {
4161           Node* m = r->raw_out(i);
4162           if (m!= nullptr && m->Opcode() == op &&
4163               m->bottom_type()->make_ptr() == t) {
4164             nn = m;
4165             break;
4166           }
4167         }
4168         if (nn != nullptr) {
4169           // Decode a narrow oop to match address
4170           // [R12 + narrow_oop_reg<<3 + offset]
4171           if (is_oop) {
4172             nn = new DecodeNNode(nn, t);
4173           } else {
4174             nn = new DecodeNKlassNode(nn, t);
4175           }
4176           // Check for succeeding AddP which uses the same Base.
4177           // Otherwise we will run into the assertion above when visiting that guy.
4178           for (uint i = 0; i < n->outcnt(); ++i) {
4179             Node *out_i = n->raw_out(i);
4180             if (out_i && out_i->is_AddP() && out_i->in(AddPNode::Base) == addp) {
4181               out_i->set_req(AddPNode::Base, nn);
4182 #ifdef ASSERT
4183               for (uint j = 0; j < out_i->outcnt(); ++j) {
4184                 Node *out_j = out_i->raw_out(j);
4185                 assert(out_j == nullptr || !out_j->is_AddP() || out_j->in(AddPNode::Base) != addp,
4186                        "more than 2 AddP nodes in a chain (out_j %u)", out_j->_idx);
4187               }
4188 #endif
4189             }
4190           }
4191           n->set_req(AddPNode::Base, nn);
4192           n->set_req(AddPNode::Address, nn);
4193           if (addp->outcnt() == 0) {
4194             addp->disconnect_inputs(this);
4195           }
4196         }
4197       }
4198     }
4199 #endif
4200     break;
4201   }
4202 
4203   case Op_CastPP: {
4204     // Remove CastPP nodes to gain more freedom during scheduling but
4205     // keep the dependency they encode as control or precedence edges
4206     // (if control is set already) on memory operations. Some CastPP
4207     // nodes don't have a control (don't carry a dependency): skip
4208     // those.
4209     if (n->in(0) != nullptr) {
4210       ResourceMark rm;
4211       Unique_Node_List wq;
4212       wq.push(n);
4213       for (uint next = 0; next < wq.size(); ++next) {
4214         Node *m = wq.at(next);
4215         for (DUIterator_Fast imax, i = m->fast_outs(imax); i < imax; i++) {
4216           Node* use = m->fast_out(i);
4217           if (use->is_Mem() || use->is_EncodeNarrowPtr()) {
4218             use->ensure_control_or_add_prec(n->in(0));
4219           } else {
4220             switch(use->Opcode()) {
4221             case Op_AddP:
4222             case Op_DecodeN:
4223             case Op_DecodeNKlass:
4224             case Op_CheckCastPP:
4225             case Op_CastPP:
4226               wq.push(use);
4227               break;
4228             }
4229           }
4230         }
4231       }
4232     }
4233     const bool is_LP64 = LP64_ONLY(true) NOT_LP64(false);
4234     if (is_LP64 && n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
4235       Node* in1 = n->in(1);
4236       const Type* t = n->bottom_type();
4237       Node* new_in1 = in1->clone();
4238       new_in1->as_DecodeN()->set_type(t);
4239 
4240       if (!Matcher::narrow_oop_use_complex_address()) {
4241         //
4242         // x86, ARM and friends can handle 2 adds in addressing mode
4243         // and Matcher can fold a DecodeN node into address by using
4244         // a narrow oop directly and do implicit null check in address:
4245         //
4246         // [R12 + narrow_oop_reg<<3 + offset]
4247         // NullCheck narrow_oop_reg
4248         //
4249         // On other platforms (Sparc) we have to keep new DecodeN node and
4250         // use it to do implicit null check in address:
4251         //
4252         // decode_not_null narrow_oop_reg, base_reg
4253         // [base_reg + offset]
4254         // NullCheck base_reg
4255         //
4256         // Pin the new DecodeN node to non-null path on these platform (Sparc)
4257         // to keep the information to which null check the new DecodeN node
4258         // corresponds to use it as value in implicit_null_check().
4259         //
4260         new_in1->set_req(0, n->in(0));
4261       }
4262 
4263       n->subsume_by(new_in1, this);
4264       if (in1->outcnt() == 0) {
4265         in1->disconnect_inputs(this);
4266       }
4267     } else {
4268       n->subsume_by(n->in(1), this);
4269       if (n->outcnt() == 0) {
4270         n->disconnect_inputs(this);
4271       }
4272     }
4273     break;
4274   }
4275   case Op_CastII: {
4276     n->as_CastII()->remove_range_check_cast(this);
4277     break;
4278   }
4279 #ifdef _LP64
4280   case Op_CmpP:
4281     // Do this transformation here to preserve CmpPNode::sub() and
4282     // other TypePtr related Ideal optimizations (for example, ptr nullness).
4283     if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
4284       Node* in1 = n->in(1);
4285       Node* in2 = n->in(2);
4286       if (!in1->is_DecodeNarrowPtr()) {
4287         in2 = in1;
4288         in1 = n->in(2);
4289       }
4290       assert(in1->is_DecodeNarrowPtr(), "sanity");
4291 
4292       Node* new_in2 = nullptr;
4293       if (in2->is_DecodeNarrowPtr()) {
4294         assert(in2->Opcode() == in1->Opcode(), "must be same node type");
4295         new_in2 = in2->in(1);
4296       } else if (in2->Opcode() == Op_ConP) {
4297         const Type* t = in2->bottom_type();
4298         if (t == TypePtr::NULL_PTR) {
4299           assert(in1->is_DecodeN(), "compare klass to null?");
4300           // Don't convert CmpP null check into CmpN if compressed
4301           // oops implicit null check is not generated.
4302           // This will allow to generate normal oop implicit null check.
4303           if (Matcher::gen_narrow_oop_implicit_null_checks())
4304             new_in2 = ConNode::make(TypeNarrowOop::NULL_PTR);
4305           //
4306           // This transformation together with CastPP transformation above
4307           // will generated code for implicit null checks for compressed oops.
4308           //
4309           // The original code after Optimize()
4310           //
4311           //    LoadN memory, narrow_oop_reg
4312           //    decode narrow_oop_reg, base_reg
4313           //    CmpP base_reg, nullptr
4314           //    CastPP base_reg // NotNull
4315           //    Load [base_reg + offset], val_reg
4316           //
4317           // after these transformations will be
4318           //
4319           //    LoadN memory, narrow_oop_reg
4320           //    CmpN narrow_oop_reg, nullptr
4321           //    decode_not_null narrow_oop_reg, base_reg
4322           //    Load [base_reg + offset], val_reg
4323           //
4324           // and the uncommon path (== nullptr) will use narrow_oop_reg directly
4325           // since narrow oops can be used in debug info now (see the code in
4326           // final_graph_reshaping_walk()).
4327           //
4328           // At the end the code will be matched to
4329           // on x86:
4330           //
4331           //    Load_narrow_oop memory, narrow_oop_reg
4332           //    Load [R12 + narrow_oop_reg<<3 + offset], val_reg
4333           //    NullCheck narrow_oop_reg
4334           //
4335           // and on sparc:
4336           //
4337           //    Load_narrow_oop memory, narrow_oop_reg
4338           //    decode_not_null narrow_oop_reg, base_reg
4339           //    Load [base_reg + offset], val_reg
4340           //    NullCheck base_reg
4341           //
4342         } else if (t->isa_oopptr()) {
4343           new_in2 = ConNode::make(t->make_narrowoop());
4344         } else if (t->isa_klassptr()) {
4345           ciKlass* klass = t->is_klassptr()->exact_klass();
4346           if (klass->is_in_encoding_range()) {
4347             new_in2 = ConNode::make(t->make_narrowklass());
4348           }
4349         }
4350       }
4351       if (new_in2 != nullptr) {
4352         Node* cmpN = new CmpNNode(in1->in(1), new_in2);
4353         n->subsume_by(cmpN, this);
4354         if (in1->outcnt() == 0) {
4355           in1->disconnect_inputs(this);
4356         }
4357         if (in2->outcnt() == 0) {
4358           in2->disconnect_inputs(this);
4359         }
4360       }
4361     }
4362     break;
4363 
4364   case Op_DecodeN:
4365   case Op_DecodeNKlass:
4366     assert(!n->in(1)->is_EncodeNarrowPtr(), "should be optimized out");
4367     // DecodeN could be pinned when it can't be fold into
4368     // an address expression, see the code for Op_CastPP above.
4369     assert(n->in(0) == nullptr || (UseCompressedOops && !Matcher::narrow_oop_use_complex_address()), "no control");
4370     break;
4371 
4372   case Op_EncodeP:
4373   case Op_EncodePKlass: {
4374     Node* in1 = n->in(1);
4375     if (in1->is_DecodeNarrowPtr()) {
4376       n->subsume_by(in1->in(1), this);
4377     } else if (in1->Opcode() == Op_ConP) {
4378       const Type* t = in1->bottom_type();
4379       if (t == TypePtr::NULL_PTR) {
4380         assert(t->isa_oopptr(), "null klass?");
4381         n->subsume_by(ConNode::make(TypeNarrowOop::NULL_PTR), this);
4382       } else if (t->isa_oopptr()) {
4383         n->subsume_by(ConNode::make(t->make_narrowoop()), this);
4384       } else if (t->isa_klassptr()) {
4385         ciKlass* klass = t->is_klassptr()->exact_klass();
4386         if (klass->is_in_encoding_range()) {
4387           n->subsume_by(ConNode::make(t->make_narrowklass()), this);
4388         } else {
4389           assert(false, "unencodable klass in ConP -> EncodeP");
4390           C->record_failure("unencodable klass in ConP -> EncodeP");
4391         }
4392       }
4393     }
4394     if (in1->outcnt() == 0) {
4395       in1->disconnect_inputs(this);
4396     }
4397     break;
4398   }
4399 
4400   case Op_Proj: {
4401     if (OptimizeStringConcat || IncrementalInline) {
4402       ProjNode* proj = n->as_Proj();
4403       if (proj->_is_io_use) {
4404         assert(proj->_con == TypeFunc::I_O || proj->_con == TypeFunc::Memory, "");
4405         // Separate projections were used for the exception path which
4406         // are normally removed by a late inline.  If it wasn't inlined
4407         // then they will hang around and should just be replaced with
4408         // the original one. Merge them.
4409         Node* non_io_proj = proj->in(0)->as_Multi()->proj_out_or_null(proj->_con, false /*is_io_use*/);
4410         if (non_io_proj  != nullptr) {
4411           proj->subsume_by(non_io_proj , this);
4412         }
4413       }
4414     }
4415     break;
4416   }
4417 
4418   case Op_Phi:
4419     if (n->as_Phi()->bottom_type()->isa_narrowoop() || n->as_Phi()->bottom_type()->isa_narrowklass()) {
4420       // The EncodeP optimization may create Phi with the same edges
4421       // for all paths. It is not handled well by Register Allocator.
4422       Node* unique_in = n->in(1);
4423       assert(unique_in != nullptr, "");
4424       uint cnt = n->req();
4425       for (uint i = 2; i < cnt; i++) {
4426         Node* m = n->in(i);
4427         assert(m != nullptr, "");
4428         if (unique_in != m)
4429           unique_in = nullptr;
4430       }
4431       if (unique_in != nullptr) {
4432         n->subsume_by(unique_in, this);
4433       }
4434     }
4435     break;
4436 
4437 #endif
4438 
4439   case Op_ModI:
4440     handle_div_mod_op(n, T_INT, false);
4441     break;
4442 
4443   case Op_ModL:
4444     handle_div_mod_op(n, T_LONG, false);
4445     break;
4446 
4447   case Op_UModI:
4448     handle_div_mod_op(n, T_INT, true);
4449     break;
4450 
4451   case Op_UModL:
4452     handle_div_mod_op(n, T_LONG, true);
4453     break;
4454 
4455   case Op_LoadVector:
4456   case Op_StoreVector:
4457 #ifdef ASSERT
4458     // Add VerifyVectorAlignment node between adr and load / store.
4459     if (VerifyAlignVector && Matcher::has_match_rule(Op_VerifyVectorAlignment)) {
4460       bool must_verify_alignment = n->is_LoadVector() ? n->as_LoadVector()->must_verify_alignment() :
4461                                                         n->as_StoreVector()->must_verify_alignment();
4462       if (must_verify_alignment) {
4463         jlong vector_width = n->is_LoadVector() ? n->as_LoadVector()->memory_size() :
4464                                                   n->as_StoreVector()->memory_size();
4465         // The memory access should be aligned to the vector width in bytes.
4466         // However, the underlying array is possibly less well aligned, but at least
4467         // to ObjectAlignmentInBytes. Hence, even if multiple arrays are accessed in
4468         // a loop we can expect at least the following alignment:
4469         jlong guaranteed_alignment = MIN2(vector_width, (jlong)ObjectAlignmentInBytes);
4470         assert(2 <= guaranteed_alignment && guaranteed_alignment <= 64, "alignment must be in range");
4471         assert(is_power_of_2(guaranteed_alignment), "alignment must be power of 2");
4472         // Create mask from alignment. e.g. 0b1000 -> 0b0111
4473         jlong mask = guaranteed_alignment - 1;
4474         Node* mask_con = ConLNode::make(mask);
4475         VerifyVectorAlignmentNode* va = new VerifyVectorAlignmentNode(n->in(MemNode::Address), mask_con);
4476         n->set_req(MemNode::Address, va);
4477       }
4478     }
4479 #endif
4480     break;
4481 
4482   case Op_LoadVectorGather:
4483   case Op_StoreVectorScatter:
4484   case Op_LoadVectorGatherMasked:
4485   case Op_StoreVectorScatterMasked:
4486   case Op_VectorCmpMasked:
4487   case Op_VectorMaskGen:
4488   case Op_LoadVectorMasked:
4489   case Op_StoreVectorMasked:
4490     break;
4491 
4492   case Op_AddReductionVI:
4493   case Op_AddReductionVL:
4494   case Op_AddReductionVF:
4495   case Op_AddReductionVD:
4496   case Op_MulReductionVI:
4497   case Op_MulReductionVL:
4498   case Op_MulReductionVF:
4499   case Op_MulReductionVD:
4500   case Op_MinReductionV:
4501   case Op_MaxReductionV:
4502   case Op_UMinReductionV:
4503   case Op_UMaxReductionV:
4504   case Op_AndReductionV:
4505   case Op_OrReductionV:
4506   case Op_XorReductionV:
4507     break;
4508 
4509   case Op_PackB:
4510   case Op_PackS:
4511   case Op_PackI:
4512   case Op_PackF:
4513   case Op_PackL:
4514   case Op_PackD:
4515     if (n->req()-1 > 2) {
4516       // Replace many operand PackNodes with a binary tree for matching
4517       PackNode* p = (PackNode*) n;
4518       Node* btp = p->binary_tree_pack(1, n->req());
4519       n->subsume_by(btp, this);
4520     }
4521     break;
4522   case Op_Loop:
4523     // When StressCountedLoop is enabled, this loop may intentionally avoid a counted loop conversion.
4524     // This is expected behavior for the stress mode, which exercises alternative compilation paths.
4525     if (!StressCountedLoop) {
4526       assert(!n->as_Loop()->is_loop_nest_inner_loop() || _loop_opts_cnt == 0, "should have been turned into a counted loop");
4527     }
4528   case Op_CountedLoop:
4529   case Op_LongCountedLoop:
4530   case Op_OuterStripMinedLoop:
4531     if (n->as_Loop()->is_inner_loop()) {
4532       frc.inc_inner_loop_count();
4533     }
4534     n->as_Loop()->verify_strip_mined(0);
4535     break;
4536   case Op_LShiftI:
4537   case Op_RShiftI:
4538   case Op_URShiftI:
4539   case Op_LShiftL:
4540   case Op_RShiftL:
4541   case Op_URShiftL:
4542     if (Matcher::need_masked_shift_count) {
4543       // The cpu's shift instructions don't restrict the count to the
4544       // lower 5/6 bits. We need to do the masking ourselves.
4545       Node* in2 = n->in(2);
4546       juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
4547       const TypeInt* t = in2->find_int_type();
4548       if (t != nullptr && t->is_con()) {
4549         juint shift = t->get_con();
4550         if (shift > mask) { // Unsigned cmp
4551           n->set_req(2, ConNode::make(TypeInt::make(shift & mask)));
4552         }
4553       } else {
4554         if (t == nullptr || t->_lo < 0 || t->_hi > (int)mask) {
4555           Node* shift = new AndINode(in2, ConNode::make(TypeInt::make(mask)));
4556           n->set_req(2, shift);
4557         }
4558       }
4559       if (in2->outcnt() == 0) { // Remove dead node
4560         in2->disconnect_inputs(this);
4561       }
4562     }
4563     break;
4564   case Op_MemBarStoreStore:
4565   case Op_MemBarRelease:
4566     // Break the link with AllocateNode: it is no longer useful and
4567     // confuses register allocation.
4568     if (n->req() > MemBarNode::Precedent) {
4569       n->set_req(MemBarNode::Precedent, top());
4570     }
4571     break;
4572   case Op_MemBarAcquire: {
4573     if (n->as_MemBar()->trailing_load() && n->req() > MemBarNode::Precedent) {
4574       // At parse time, the trailing MemBarAcquire for a volatile load
4575       // is created with an edge to the load. After optimizations,
4576       // that input may be a chain of Phis. If those phis have no
4577       // other use, then the MemBarAcquire keeps them alive and
4578       // register allocation can be confused.
4579       dead_nodes.push(n->in(MemBarNode::Precedent));
4580       n->set_req(MemBarNode::Precedent, top());
4581     }
4582     break;
4583   }
4584   case Op_Blackhole:
4585     break;
4586   case Op_RangeCheck: {
4587     RangeCheckNode* rc = n->as_RangeCheck();
4588     Node* iff = new IfNode(rc->in(0), rc->in(1), rc->_prob, rc->_fcnt);
4589     n->subsume_by(iff, this);
4590     frc._tests.push(iff);
4591     break;
4592   }
4593   case Op_ConvI2L: {
4594     if (!Matcher::convi2l_type_required) {
4595       // Code generation on some platforms doesn't need accurate
4596       // ConvI2L types. Widening the type can help remove redundant
4597       // address computations.
4598       n->as_Type()->set_type(TypeLong::INT);
4599       ResourceMark rm;
4600       Unique_Node_List wq;
4601       wq.push(n);
4602       for (uint next = 0; next < wq.size(); next++) {
4603         Node *m = wq.at(next);
4604 
4605         for(;;) {
4606           // Loop over all nodes with identical inputs edges as m
4607           Node* k = m->find_similar(m->Opcode());
4608           if (k == nullptr) {
4609             break;
4610           }
4611           // Push their uses so we get a chance to remove node made
4612           // redundant
4613           for (DUIterator_Fast imax, i = k->fast_outs(imax); i < imax; i++) {
4614             Node* u = k->fast_out(i);
4615             if (u->Opcode() == Op_LShiftL ||
4616                 u->Opcode() == Op_AddL ||
4617                 u->Opcode() == Op_SubL ||
4618                 u->Opcode() == Op_AddP) {
4619               wq.push(u);
4620             }
4621           }
4622           // Replace all nodes with identical edges as m with m
4623           k->subsume_by(m, this);
4624         }
4625       }
4626     }
4627     break;
4628   }
4629   case Op_CmpUL: {
4630     if (!Matcher::has_match_rule(Op_CmpUL)) {
4631       // No support for unsigned long comparisons
4632       ConINode* sign_pos = new ConINode(TypeInt::make(BitsPerLong - 1));
4633       Node* sign_bit_mask = new RShiftLNode(n->in(1), sign_pos);
4634       Node* orl = new OrLNode(n->in(1), sign_bit_mask);
4635       ConLNode* remove_sign_mask = new ConLNode(TypeLong::make(max_jlong));
4636       Node* andl = new AndLNode(orl, remove_sign_mask);
4637       Node* cmp = new CmpLNode(andl, n->in(2));
4638       n->subsume_by(cmp, this);
4639     }
4640     break;
4641   }
4642 #ifdef ASSERT
4643   case Op_InlineType: {
4644     n->dump(-1);
4645     assert(false, "inline type node was not removed");
4646     break;
4647   }
4648   case Op_ConNKlass: {
4649     const TypePtr* tp = n->as_Type()->type()->make_ptr();
4650     ciKlass* klass = tp->is_klassptr()->exact_klass();
4651     assert(klass->is_in_encoding_range(), "klass cannot be compressed");
4652     break;
4653   }
4654 #endif
4655   default:
4656     assert(!n->is_Call(), "");
4657     assert(!n->is_Mem(), "");
4658     assert(nop != Op_ProfileBoolean, "should be eliminated during IGVN");
4659     break;
4660   }
4661 }
4662 
4663 //------------------------------final_graph_reshaping_walk---------------------
4664 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
4665 // requires that the walk visits a node's inputs before visiting the node.
4666 void Compile::final_graph_reshaping_walk(Node_Stack& nstack, Node* root, Final_Reshape_Counts& frc, Unique_Node_List& dead_nodes) {
4667   Unique_Node_List sfpt;
4668 
4669   frc._visited.set(root->_idx); // first, mark node as visited
4670   uint cnt = root->req();
4671   Node *n = root;
4672   uint  i = 0;
4673   while (true) {
4674     if (i < cnt) {
4675       // Place all non-visited non-null inputs onto stack
4676       Node* m = n->in(i);
4677       ++i;
4678       if (m != nullptr && !frc._visited.test_set(m->_idx)) {
4679         if (m->is_SafePoint() && m->as_SafePoint()->jvms() != nullptr) {
4680           // compute worst case interpreter size in case of a deoptimization
4681           update_interpreter_frame_size(m->as_SafePoint()->jvms()->interpreter_frame_size());
4682 
4683           sfpt.push(m);
4684         }
4685         cnt = m->req();
4686         nstack.push(n, i); // put on stack parent and next input's index
4687         n = m;
4688         i = 0;
4689       }
4690     } else {
4691       // Now do post-visit work
4692       final_graph_reshaping_impl(n, frc, dead_nodes);
4693       if (nstack.is_empty())
4694         break;             // finished
4695       n = nstack.node();   // Get node from stack
4696       cnt = n->req();
4697       i = nstack.index();
4698       nstack.pop();        // Shift to the next node on stack
4699     }
4700   }
4701 
4702   // Skip next transformation if compressed oops are not used.
4703   if (UseCompressedOops && !Matcher::gen_narrow_oop_implicit_null_checks())
4704     return;
4705 
4706   // Go over safepoints nodes to skip DecodeN/DecodeNKlass nodes for debug edges.
4707   // It could be done for an uncommon traps or any safepoints/calls
4708   // if the DecodeN/DecodeNKlass node is referenced only in a debug info.
4709   while (sfpt.size() > 0) {
4710     n = sfpt.pop();
4711     JVMState *jvms = n->as_SafePoint()->jvms();
4712     assert(jvms != nullptr, "sanity");
4713     int start = jvms->debug_start();
4714     int end   = n->req();
4715     bool is_uncommon = (n->is_CallStaticJava() &&
4716                         n->as_CallStaticJava()->uncommon_trap_request() != 0);
4717     for (int j = start; j < end; j++) {
4718       Node* in = n->in(j);
4719       if (in->is_DecodeNarrowPtr()) {
4720         bool safe_to_skip = true;
4721         if (!is_uncommon ) {
4722           // Is it safe to skip?
4723           for (uint i = 0; i < in->outcnt(); i++) {
4724             Node* u = in->raw_out(i);
4725             if (!u->is_SafePoint() ||
4726                 (u->is_Call() && u->as_Call()->has_non_debug_use(n))) {
4727               safe_to_skip = false;
4728             }
4729           }
4730         }
4731         if (safe_to_skip) {
4732           n->set_req(j, in->in(1));
4733         }
4734         if (in->outcnt() == 0) {
4735           in->disconnect_inputs(this);
4736         }
4737       }
4738     }
4739   }
4740 }
4741 
4742 //------------------------------final_graph_reshaping--------------------------
4743 // Final Graph Reshaping.
4744 //
4745 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
4746 //     and not commoned up and forced early.  Must come after regular
4747 //     optimizations to avoid GVN undoing the cloning.  Clone constant
4748 //     inputs to Loop Phis; these will be split by the allocator anyways.
4749 //     Remove Opaque nodes.
4750 // (2) Move last-uses by commutative operations to the left input to encourage
4751 //     Intel update-in-place two-address operations and better register usage
4752 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
4753 //     calls canonicalizing them back.
4754 // (3) Count the number of double-precision FP ops, single-precision FP ops
4755 //     and call sites.  On Intel, we can get correct rounding either by
4756 //     forcing singles to memory (requires extra stores and loads after each
4757 //     FP bytecode) or we can set a rounding mode bit (requires setting and
4758 //     clearing the mode bit around call sites).  The mode bit is only used
4759 //     if the relative frequency of single FP ops to calls is low enough.
4760 //     This is a key transform for SPEC mpeg_audio.
4761 // (4) Detect infinite loops; blobs of code reachable from above but not
4762 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
4763 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
4764 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
4765 //     Detection is by looking for IfNodes where only 1 projection is
4766 //     reachable from below or CatchNodes missing some targets.
4767 // (5) Assert for insane oop offsets in debug mode.
4768 
4769 bool Compile::final_graph_reshaping() {
4770   // an infinite loop may have been eliminated by the optimizer,
4771   // in which case the graph will be empty.
4772   if (root()->req() == 1) {
4773     // Do not compile method that is only a trivial infinite loop,
4774     // since the content of the loop may have been eliminated.
4775     record_method_not_compilable("trivial infinite loop");
4776     return true;
4777   }
4778 
4779   // Expensive nodes have their control input set to prevent the GVN
4780   // from freely commoning them. There's no GVN beyond this point so
4781   // no need to keep the control input. We want the expensive nodes to
4782   // be freely moved to the least frequent code path by gcm.
4783   assert(OptimizeExpensiveOps || expensive_count() == 0, "optimization off but list non empty?");
4784   for (int i = 0; i < expensive_count(); i++) {
4785     _expensive_nodes.at(i)->set_req(0, nullptr);
4786   }
4787 
4788   Final_Reshape_Counts frc;
4789 
4790   // Visit everybody reachable!
4791   // Allocate stack of size C->live_nodes()/2 to avoid frequent realloc
4792   Node_Stack nstack(live_nodes() >> 1);
4793   Unique_Node_List dead_nodes;
4794   final_graph_reshaping_walk(nstack, root(), frc, dead_nodes);
4795 
4796   // Check for unreachable (from below) code (i.e., infinite loops).
4797   for( uint i = 0; i < frc._tests.size(); i++ ) {
4798     MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
4799     // Get number of CFG targets.
4800     // Note that PCTables include exception targets after calls.
4801     uint required_outcnt = n->required_outcnt();
4802     if (n->outcnt() != required_outcnt) {
4803       // Check for a few special cases.  Rethrow Nodes never take the
4804       // 'fall-thru' path, so expected kids is 1 less.
4805       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
4806         if (n->in(0)->in(0)->is_Call()) {
4807           CallNode* call = n->in(0)->in(0)->as_Call();
4808           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
4809             required_outcnt--;      // Rethrow always has 1 less kid
4810           } else if (call->req() > TypeFunc::Parms &&
4811                      call->is_CallDynamicJava()) {
4812             // Check for null receiver. In such case, the optimizer has
4813             // detected that the virtual call will always result in a null
4814             // pointer exception. The fall-through projection of this CatchNode
4815             // will not be populated.
4816             Node* arg0 = call->in(TypeFunc::Parms);
4817             if (arg0->is_Type() &&
4818                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
4819               required_outcnt--;
4820             }
4821           } else if (call->entry_point() == OptoRuntime::new_array_Java() ||
4822                      call->entry_point() == OptoRuntime::new_array_nozero_Java()) {
4823             // Check for illegal array length. In such case, the optimizer has
4824             // detected that the allocation attempt will always result in an
4825             // exception. There is no fall-through projection of this CatchNode .
4826             assert(call->is_CallStaticJava(), "static call expected");
4827             assert(call->req() == call->jvms()->endoff() + 1, "missing extra input");
4828             uint valid_length_test_input = call->req() - 1;
4829             Node* valid_length_test = call->in(valid_length_test_input);
4830             call->del_req(valid_length_test_input);
4831             if (valid_length_test->find_int_con(1) == 0) {
4832               required_outcnt--;
4833             }
4834             dead_nodes.push(valid_length_test);
4835             assert(n->outcnt() == required_outcnt, "malformed control flow");
4836             continue;
4837           }
4838         }
4839       }
4840 
4841       // Recheck with a better notion of 'required_outcnt'
4842       if (n->outcnt() != required_outcnt) {
4843         record_method_not_compilable("malformed control flow");
4844         return true;            // Not all targets reachable!
4845       }
4846     } else if (n->is_PCTable() && n->in(0) && n->in(0)->in(0) && n->in(0)->in(0)->is_Call()) {
4847       CallNode* call = n->in(0)->in(0)->as_Call();
4848       if (call->entry_point() == OptoRuntime::new_array_Java() ||
4849           call->entry_point() == OptoRuntime::new_array_nozero_Java()) {
4850         assert(call->is_CallStaticJava(), "static call expected");
4851         assert(call->req() == call->jvms()->endoff() + 1, "missing extra input");
4852         uint valid_length_test_input = call->req() - 1;
4853         dead_nodes.push(call->in(valid_length_test_input));
4854         call->del_req(valid_length_test_input); // valid length test useless now
4855       }
4856     }
4857     // Check that I actually visited all kids.  Unreached kids
4858     // must be infinite loops.
4859     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
4860       if (!frc._visited.test(n->fast_out(j)->_idx)) {
4861         record_method_not_compilable("infinite loop");
4862         return true;            // Found unvisited kid; must be unreach
4863       }
4864 
4865     // Here so verification code in final_graph_reshaping_walk()
4866     // always see an OuterStripMinedLoopEnd
4867     if (n->is_OuterStripMinedLoopEnd() || n->is_LongCountedLoopEnd()) {
4868       IfNode* init_iff = n->as_If();
4869       Node* iff = new IfNode(init_iff->in(0), init_iff->in(1), init_iff->_prob, init_iff->_fcnt);
4870       n->subsume_by(iff, this);
4871     }
4872   }
4873 
4874   while (dead_nodes.size() > 0) {
4875     Node* m = dead_nodes.pop();
4876     if (m->outcnt() == 0 && m != top()) {
4877       for (uint j = 0; j < m->req(); j++) {
4878         Node* in = m->in(j);
4879         if (in != nullptr) {
4880           dead_nodes.push(in);
4881         }
4882       }
4883       m->disconnect_inputs(this);
4884     }
4885   }
4886 
4887   set_java_calls(frc.get_java_call_count());
4888   set_inner_loops(frc.get_inner_loop_count());
4889 
4890   // No infinite loops, no reason to bail out.
4891   return false;
4892 }
4893 
4894 //-----------------------------too_many_traps----------------------------------
4895 // Report if there are too many traps at the current method and bci.
4896 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
4897 bool Compile::too_many_traps(ciMethod* method,
4898                              int bci,
4899                              Deoptimization::DeoptReason reason) {
4900   ciMethodData* md = method->method_data();
4901   if (md->is_empty()) {
4902     // Assume the trap has not occurred, or that it occurred only
4903     // because of a transient condition during start-up in the interpreter.
4904     return false;
4905   }
4906   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : nullptr;
4907   if (md->has_trap_at(bci, m, reason) != 0) {
4908     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
4909     // Also, if there are multiple reasons, or if there is no per-BCI record,
4910     // assume the worst.
4911     if (log())
4912       log()->elem("observe trap='%s' count='%d'",
4913                   Deoptimization::trap_reason_name(reason),
4914                   md->trap_count(reason));
4915     return true;
4916   } else {
4917     // Ignore method/bci and see if there have been too many globally.
4918     return too_many_traps(reason, md);
4919   }
4920 }
4921 
4922 // Less-accurate variant which does not require a method and bci.
4923 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
4924                              ciMethodData* logmd) {
4925   if (trap_count(reason) >= Deoptimization::per_method_trap_limit(reason)) {
4926     // Too many traps globally.
4927     // Note that we use cumulative trap_count, not just md->trap_count.
4928     if (log()) {
4929       int mcount = (logmd == nullptr)? -1: (int)logmd->trap_count(reason);
4930       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
4931                   Deoptimization::trap_reason_name(reason),
4932                   mcount, trap_count(reason));
4933     }
4934     return true;
4935   } else {
4936     // The coast is clear.
4937     return false;
4938   }
4939 }
4940 
4941 //--------------------------too_many_recompiles--------------------------------
4942 // Report if there are too many recompiles at the current method and bci.
4943 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
4944 // Is not eager to return true, since this will cause the compiler to use
4945 // Action_none for a trap point, to avoid too many recompilations.
4946 bool Compile::too_many_recompiles(ciMethod* method,
4947                                   int bci,
4948                                   Deoptimization::DeoptReason reason) {
4949   ciMethodData* md = method->method_data();
4950   if (md->is_empty()) {
4951     // Assume the trap has not occurred, or that it occurred only
4952     // because of a transient condition during start-up in the interpreter.
4953     return false;
4954   }
4955   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
4956   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
4957   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
4958   Deoptimization::DeoptReason per_bc_reason
4959     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
4960   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : nullptr;
4961   if ((per_bc_reason == Deoptimization::Reason_none
4962        || md->has_trap_at(bci, m, reason) != 0)
4963       // The trap frequency measure we care about is the recompile count:
4964       && md->trap_recompiled_at(bci, m)
4965       && md->overflow_recompile_count() >= bc_cutoff) {
4966     // Do not emit a trap here if it has already caused recompilations.
4967     // Also, if there are multiple reasons, or if there is no per-BCI record,
4968     // assume the worst.
4969     if (log())
4970       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
4971                   Deoptimization::trap_reason_name(reason),
4972                   md->trap_count(reason),
4973                   md->overflow_recompile_count());
4974     return true;
4975   } else if (trap_count(reason) != 0
4976              && decompile_count() >= m_cutoff) {
4977     // Too many recompiles globally, and we have seen this sort of trap.
4978     // Use cumulative decompile_count, not just md->decompile_count.
4979     if (log())
4980       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
4981                   Deoptimization::trap_reason_name(reason),
4982                   md->trap_count(reason), trap_count(reason),
4983                   md->decompile_count(), decompile_count());
4984     return true;
4985   } else {
4986     // The coast is clear.
4987     return false;
4988   }
4989 }
4990 
4991 // Compute when not to trap. Used by matching trap based nodes and
4992 // NullCheck optimization.
4993 void Compile::set_allowed_deopt_reasons() {
4994   _allowed_reasons = 0;
4995   if (is_method_compilation()) {
4996     for (int rs = (int)Deoptimization::Reason_none+1; rs < Compile::trapHistLength; rs++) {
4997       assert(rs < BitsPerInt, "recode bit map");
4998       if (!too_many_traps((Deoptimization::DeoptReason) rs)) {
4999         _allowed_reasons |= nth_bit(rs);
5000       }
5001     }
5002   }
5003 }
5004 
5005 bool Compile::needs_clinit_barrier(ciMethod* method, ciMethod* accessing_method) {
5006   return method->is_static() && needs_clinit_barrier(method->holder(), accessing_method);
5007 }
5008 
5009 bool Compile::needs_clinit_barrier(ciField* field, ciMethod* accessing_method) {
5010   return field->is_static() && needs_clinit_barrier(field->holder(), accessing_method);
5011 }
5012 
5013 bool Compile::needs_clinit_barrier(ciInstanceKlass* holder, ciMethod* accessing_method) {
5014   if (holder->is_initialized()) {
5015     return false;
5016   }
5017   if (holder->is_being_initialized()) {
5018     if (accessing_method->holder() == holder) {
5019       // Access inside a class. The barrier can be elided when access happens in <clinit>,
5020       // <init>, or a static method. In all those cases, there was an initialization
5021       // barrier on the holder klass passed.
5022       if (accessing_method->is_class_initializer() ||
5023           accessing_method->is_object_constructor() ||
5024           accessing_method->is_static()) {
5025         return false;
5026       }
5027     } else if (accessing_method->holder()->is_subclass_of(holder)) {
5028       // Access from a subclass. The barrier can be elided only when access happens in <clinit>.
5029       // In case of <init> or a static method, the barrier is on the subclass is not enough:
5030       // child class can become fully initialized while its parent class is still being initialized.
5031       if (accessing_method->is_class_initializer()) {
5032         return false;
5033       }
5034     }
5035     ciMethod* root = method(); // the root method of compilation
5036     if (root != accessing_method) {
5037       return needs_clinit_barrier(holder, root); // check access in the context of compilation root
5038     }
5039   }
5040   return true;
5041 }
5042 
5043 #ifndef PRODUCT
5044 //------------------------------verify_bidirectional_edges---------------------
5045 // For each input edge to a node (ie - for each Use-Def edge), verify that
5046 // there is a corresponding Def-Use edge.
5047 void Compile::verify_bidirectional_edges(Unique_Node_List& visited, const Unique_Node_List* root_and_safepoints) const {
5048   // Allocate stack of size C->live_nodes()/16 to avoid frequent realloc
5049   uint stack_size = live_nodes() >> 4;
5050   Node_List nstack(MAX2(stack_size, (uint) OptoNodeListSize));
5051   if (root_and_safepoints != nullptr) {
5052     assert(root_and_safepoints->member(_root), "root is not in root_and_safepoints");
5053     for (uint i = 0, limit = root_and_safepoints->size(); i < limit; i++) {
5054       Node* root_or_safepoint = root_and_safepoints->at(i);
5055       // If the node is a safepoint, let's check if it still has a control input
5056       // Lack of control input signifies that this node was killed by CCP or
5057       // recursively by remove_globally_dead_node and it shouldn't be a starting
5058       // point.
5059       if (!root_or_safepoint->is_SafePoint() || root_or_safepoint->in(0) != nullptr) {
5060         nstack.push(root_or_safepoint);
5061       }
5062     }
5063   } else {
5064     nstack.push(_root);
5065   }
5066 
5067   while (nstack.size() > 0) {
5068     Node* n = nstack.pop();
5069     if (visited.member(n)) {
5070       continue;
5071     }
5072     visited.push(n);
5073 
5074     // Walk over all input edges, checking for correspondence
5075     uint length = n->len();
5076     for (uint i = 0; i < length; i++) {
5077       Node* in = n->in(i);
5078       if (in != nullptr && !visited.member(in)) {
5079         nstack.push(in); // Put it on stack
5080       }
5081       if (in != nullptr && !in->is_top()) {
5082         // Count instances of `next`
5083         int cnt = 0;
5084         for (uint idx = 0; idx < in->_outcnt; idx++) {
5085           if (in->_out[idx] == n) {
5086             cnt++;
5087           }
5088         }
5089         assert(cnt > 0, "Failed to find Def-Use edge.");
5090         // Check for duplicate edges
5091         // walk the input array downcounting the input edges to n
5092         for (uint j = 0; j < length; j++) {
5093           if (n->in(j) == in) {
5094             cnt--;
5095           }
5096         }
5097         assert(cnt == 0, "Mismatched edge count.");
5098       } else if (in == nullptr) {
5099         assert(i == 0 || i >= n->req() ||
5100                n->is_Region() || n->is_Phi() || n->is_ArrayCopy() ||
5101                (n->is_Allocate() && i >= AllocateNode::InlineType) ||
5102                (n->is_Unlock() && i == (n->req() - 1)) ||
5103                (n->is_MemBar() && i == 5), // the precedence edge to a membar can be removed during macro node expansion
5104               "only region, phi, arraycopy, allocate, unlock or membar nodes have null data edges");
5105       } else {
5106         assert(in->is_top(), "sanity");
5107         // Nothing to check.
5108       }
5109     }
5110   }
5111 }
5112 
5113 //------------------------------verify_graph_edges---------------------------
5114 // Walk the Graph and verify that there is a one-to-one correspondence
5115 // between Use-Def edges and Def-Use edges in the graph.
5116 void Compile::verify_graph_edges(bool no_dead_code, const Unique_Node_List* root_and_safepoints) const {
5117   if (VerifyGraphEdges) {
5118     Unique_Node_List visited;
5119 
5120     // Call graph walk to check edges
5121     verify_bidirectional_edges(visited, root_and_safepoints);
5122     if (no_dead_code) {
5123       // Now make sure that no visited node is used by an unvisited node.
5124       bool dead_nodes = false;
5125       Unique_Node_List checked;
5126       while (visited.size() > 0) {
5127         Node* n = visited.pop();
5128         checked.push(n);
5129         for (uint i = 0; i < n->outcnt(); i++) {
5130           Node* use = n->raw_out(i);
5131           if (checked.member(use))  continue;  // already checked
5132           if (visited.member(use))  continue;  // already in the graph
5133           if (use->is_Con())        continue;  // a dead ConNode is OK
5134           // At this point, we have found a dead node which is DU-reachable.
5135           if (!dead_nodes) {
5136             tty->print_cr("*** Dead nodes reachable via DU edges:");
5137             dead_nodes = true;
5138           }
5139           use->dump(2);
5140           tty->print_cr("---");
5141           checked.push(use);  // No repeats; pretend it is now checked.
5142         }
5143       }
5144       assert(!dead_nodes, "using nodes must be reachable from root");
5145     }
5146   }
5147 }
5148 #endif
5149 
5150 // The Compile object keeps track of failure reasons separately from the ciEnv.
5151 // This is required because there is not quite a 1-1 relation between the
5152 // ciEnv and its compilation task and the Compile object.  Note that one
5153 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
5154 // to backtrack and retry without subsuming loads.  Other than this backtracking
5155 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
5156 // by the logic in C2Compiler.
5157 void Compile::record_failure(const char* reason DEBUG_ONLY(COMMA bool allow_multiple_failures)) {
5158   if (log() != nullptr) {
5159     log()->elem("failure reason='%s' phase='compile'", reason);
5160   }
5161   if (_failure_reason.get() == nullptr) {
5162     // Record the first failure reason.
5163     _failure_reason.set(reason);
5164     if (CaptureBailoutInformation) {
5165       _first_failure_details = new CompilationFailureInfo(reason);
5166     }
5167   } else {
5168     assert(!StressBailout || allow_multiple_failures, "should have handled previous failure.");
5169   }
5170 
5171   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
5172     C->print_method(PHASE_FAILURE, 1);
5173   }
5174   _root = nullptr;  // flush the graph, too
5175 }
5176 
5177 Compile::TracePhase::TracePhase(const char* name, PhaseTraceId id)
5178   : TraceTime(name, &Phase::timers[id], CITime, CITimeVerbose),
5179     _compile(Compile::current()),
5180     _log(nullptr),
5181     _dolog(CITimeVerbose)
5182 {
5183   assert(_compile != nullptr, "sanity check");
5184   assert(id != PhaseTraceId::_t_none, "Don't use none");
5185   if (_dolog) {
5186     _log = _compile->log();
5187   }
5188   if (_log != nullptr) {
5189     _log->begin_head("phase name='%s' nodes='%d' live='%d'", phase_name(), _compile->unique(), _compile->live_nodes());
5190     _log->stamp();
5191     _log->end_head();
5192   }
5193 
5194   // Inform memory statistic, if enabled
5195   if (CompilationMemoryStatistic::enabled()) {
5196     CompilationMemoryStatistic::on_phase_start((int)id, name);
5197   }
5198 }
5199 
5200 Compile::TracePhase::TracePhase(PhaseTraceId id)
5201   : TracePhase(Phase::get_phase_trace_id_text(id), id) {}
5202 
5203 Compile::TracePhase::~TracePhase() {
5204 
5205   // Inform memory statistic, if enabled
5206   if (CompilationMemoryStatistic::enabled()) {
5207     CompilationMemoryStatistic::on_phase_end();
5208   }
5209 
5210   if (_compile->failing_internal()) {
5211     if (_log != nullptr) {
5212       _log->done("phase");
5213     }
5214     return; // timing code, not stressing bailouts.
5215   }
5216 #ifdef ASSERT
5217   if (PrintIdealNodeCount) {
5218     tty->print_cr("phase name='%s' nodes='%d' live='%d' live_graph_walk='%d'",
5219                   phase_name(), _compile->unique(), _compile->live_nodes(), _compile->count_live_nodes_by_graph_walk());
5220   }
5221 
5222   if (VerifyIdealNodeCount) {
5223     _compile->print_missing_nodes();
5224   }
5225 #endif
5226 
5227   if (_log != nullptr) {
5228     _log->done("phase name='%s' nodes='%d' live='%d'", phase_name(), _compile->unique(), _compile->live_nodes());
5229   }
5230 }
5231 
5232 //----------------------------static_subtype_check-----------------------------
5233 // Shortcut important common cases when superklass is exact:
5234 // (0) superklass is java.lang.Object (can occur in reflective code)
5235 // (1) subklass is already limited to a subtype of superklass => always ok
5236 // (2) subklass does not overlap with superklass => always fail
5237 // (3) superklass has NO subtypes and we can check with a simple compare.
5238 Compile::SubTypeCheckResult Compile::static_subtype_check(const TypeKlassPtr* superk, const TypeKlassPtr* subk, bool skip) {
5239   if (skip) {
5240     return SSC_full_test;       // Let caller generate the general case.
5241   }
5242 
5243   if (subk->is_java_subtype_of(superk)) {
5244     return SSC_always_true; // (0) and (1)  this test cannot fail
5245   }
5246 
5247   if (!subk->maybe_java_subtype_of(superk)) {
5248     return SSC_always_false; // (2) true path dead; no dynamic test needed
5249   }
5250 
5251   const Type* superelem = superk;
5252   if (superk->isa_aryklassptr()) {
5253     int ignored;
5254     superelem = superk->is_aryklassptr()->base_element_type(ignored);
5255 
5256     // Do not fold the subtype check to an array klass pointer comparison for null-able inline type arrays
5257     // because null-free [LMyValue <: null-able [LMyValue but the klasses are different. Perform a full test.
5258     if (!superk->is_aryklassptr()->is_null_free() && superk->is_aryklassptr()->elem()->isa_instklassptr() &&
5259         superk->is_aryklassptr()->elem()->is_instklassptr()->instance_klass()->is_inlinetype()) {
5260       return SSC_full_test;
5261     }
5262   }
5263 
5264   if (superelem->isa_instklassptr()) {
5265     ciInstanceKlass* ik = superelem->is_instklassptr()->instance_klass();
5266     if (!ik->has_subklass()) {
5267       if (!ik->is_final()) {
5268         // Add a dependency if there is a chance of a later subclass.
5269         dependencies()->assert_leaf_type(ik);
5270       }
5271       if (!superk->maybe_java_subtype_of(subk)) {
5272         return SSC_always_false;
5273       }
5274       return SSC_easy_test;     // (3) caller can do a simple ptr comparison
5275     }
5276   } else {
5277     // A primitive array type has no subtypes.
5278     return SSC_easy_test;       // (3) caller can do a simple ptr comparison
5279   }
5280 
5281   return SSC_full_test;
5282 }
5283 
5284 Node* Compile::conv_I2X_index(PhaseGVN* phase, Node* idx, const TypeInt* sizetype, Node* ctrl) {
5285 #ifdef _LP64
5286   // The scaled index operand to AddP must be a clean 64-bit value.
5287   // Java allows a 32-bit int to be incremented to a negative
5288   // value, which appears in a 64-bit register as a large
5289   // positive number.  Using that large positive number as an
5290   // operand in pointer arithmetic has bad consequences.
5291   // On the other hand, 32-bit overflow is rare, and the possibility
5292   // can often be excluded, if we annotate the ConvI2L node with
5293   // a type assertion that its value is known to be a small positive
5294   // number.  (The prior range check has ensured this.)
5295   // This assertion is used by ConvI2LNode::Ideal.
5296   int index_max = max_jint - 1;  // array size is max_jint, index is one less
5297   if (sizetype != nullptr && sizetype->_hi > 0) {
5298     index_max = sizetype->_hi - 1;
5299   }
5300   const TypeInt* iidxtype = TypeInt::make(0, index_max, Type::WidenMax);
5301   idx = constrained_convI2L(phase, idx, iidxtype, ctrl);
5302 #endif
5303   return idx;
5304 }
5305 
5306 // Convert integer value to a narrowed long type dependent on ctrl (for example, a range check)
5307 Node* Compile::constrained_convI2L(PhaseGVN* phase, Node* value, const TypeInt* itype, Node* ctrl, bool carry_dependency) {
5308   if (ctrl != nullptr) {
5309     // Express control dependency by a CastII node with a narrow type.
5310     // Make the CastII node dependent on the control input to prevent the narrowed ConvI2L
5311     // node from floating above the range check during loop optimizations. Otherwise, the
5312     // ConvI2L node may be eliminated independently of the range check, causing the data path
5313     // to become TOP while the control path is still there (although it's unreachable).
5314     value = new CastIINode(ctrl, value, itype, carry_dependency ? ConstraintCastNode::DependencyType::NonFloatingNarrowing : ConstraintCastNode::DependencyType::FloatingNarrowing, true /* range check dependency */);
5315     value = phase->transform(value);
5316   }
5317   const TypeLong* ltype = TypeLong::make(itype->_lo, itype->_hi, itype->_widen);
5318   return phase->transform(new ConvI2LNode(value, ltype));
5319 }
5320 
5321 void Compile::dump_print_inlining() {
5322   inline_printer()->print_on(tty);
5323 }
5324 
5325 void Compile::log_late_inline(CallGenerator* cg) {
5326   if (log() != nullptr) {
5327     log()->head("late_inline method='%d' inline_id='" JLONG_FORMAT "'", log()->identify(cg->method()),
5328                 cg->unique_id());
5329     JVMState* p = cg->call_node()->jvms();
5330     while (p != nullptr) {
5331       log()->elem("jvms bci='%d' method='%d'", p->bci(), log()->identify(p->method()));
5332       p = p->caller();
5333     }
5334     log()->tail("late_inline");
5335   }
5336 }
5337 
5338 void Compile::log_late_inline_failure(CallGenerator* cg, const char* msg) {
5339   log_late_inline(cg);
5340   if (log() != nullptr) {
5341     log()->inline_fail(msg);
5342   }
5343 }
5344 
5345 void Compile::log_inline_id(CallGenerator* cg) {
5346   if (log() != nullptr) {
5347     // The LogCompilation tool needs a unique way to identify late
5348     // inline call sites. This id must be unique for this call site in
5349     // this compilation. Try to have it unique across compilations as
5350     // well because it can be convenient when grepping through the log
5351     // file.
5352     // Distinguish OSR compilations from others in case CICountOSR is
5353     // on.
5354     jlong id = ((jlong)unique()) + (((jlong)compile_id()) << 33) + (CICountOSR && is_osr_compilation() ? ((jlong)1) << 32 : 0);
5355     cg->set_unique_id(id);
5356     log()->elem("inline_id id='" JLONG_FORMAT "'", id);
5357   }
5358 }
5359 
5360 void Compile::log_inline_failure(const char* msg) {
5361   if (C->log() != nullptr) {
5362     C->log()->inline_fail(msg);
5363   }
5364 }
5365 
5366 
5367 // Dump inlining replay data to the stream.
5368 // Don't change thread state and acquire any locks.
5369 void Compile::dump_inline_data(outputStream* out) {
5370   InlineTree* inl_tree = ilt();
5371   if (inl_tree != nullptr) {
5372     out->print(" inline %d", inl_tree->count());
5373     inl_tree->dump_replay_data(out);
5374   }
5375 }
5376 
5377 void Compile::dump_inline_data_reduced(outputStream* out) {
5378   assert(ReplayReduce, "");
5379 
5380   InlineTree* inl_tree = ilt();
5381   if (inl_tree == nullptr) {
5382     return;
5383   }
5384   // Enable iterative replay file reduction
5385   // Output "compile" lines for depth 1 subtrees,
5386   // simulating that those trees were compiled
5387   // instead of inlined.
5388   for (int i = 0; i < inl_tree->subtrees().length(); ++i) {
5389     InlineTree* sub = inl_tree->subtrees().at(i);
5390     if (sub->inline_level() != 1) {
5391       continue;
5392     }
5393 
5394     ciMethod* method = sub->method();
5395     int entry_bci = -1;
5396     int comp_level = env()->task()->comp_level();
5397     out->print("compile ");
5398     method->dump_name_as_ascii(out);
5399     out->print(" %d %d", entry_bci, comp_level);
5400     out->print(" inline %d", sub->count());
5401     sub->dump_replay_data(out, -1);
5402     out->cr();
5403   }
5404 }
5405 
5406 int Compile::cmp_expensive_nodes(Node* n1, Node* n2) {
5407   if (n1->Opcode() < n2->Opcode())      return -1;
5408   else if (n1->Opcode() > n2->Opcode()) return 1;
5409 
5410   assert(n1->req() == n2->req(), "can't compare %s nodes: n1->req() = %d, n2->req() = %d", NodeClassNames[n1->Opcode()], n1->req(), n2->req());
5411   for (uint i = 1; i < n1->req(); i++) {
5412     if (n1->in(i) < n2->in(i))      return -1;
5413     else if (n1->in(i) > n2->in(i)) return 1;
5414   }
5415 
5416   return 0;
5417 }
5418 
5419 int Compile::cmp_expensive_nodes(Node** n1p, Node** n2p) {
5420   Node* n1 = *n1p;
5421   Node* n2 = *n2p;
5422 
5423   return cmp_expensive_nodes(n1, n2);
5424 }
5425 
5426 void Compile::sort_expensive_nodes() {
5427   if (!expensive_nodes_sorted()) {
5428     _expensive_nodes.sort(cmp_expensive_nodes);
5429   }
5430 }
5431 
5432 bool Compile::expensive_nodes_sorted() const {
5433   for (int i = 1; i < _expensive_nodes.length(); i++) {
5434     if (cmp_expensive_nodes(_expensive_nodes.adr_at(i), _expensive_nodes.adr_at(i-1)) < 0) {
5435       return false;
5436     }
5437   }
5438   return true;
5439 }
5440 
5441 bool Compile::should_optimize_expensive_nodes(PhaseIterGVN &igvn) {
5442   if (_expensive_nodes.length() == 0) {
5443     return false;
5444   }
5445 
5446   assert(OptimizeExpensiveOps, "optimization off?");
5447 
5448   // Take this opportunity to remove dead nodes from the list
5449   int j = 0;
5450   for (int i = 0; i < _expensive_nodes.length(); i++) {
5451     Node* n = _expensive_nodes.at(i);
5452     if (!n->is_unreachable(igvn)) {
5453       assert(n->is_expensive(), "should be expensive");
5454       _expensive_nodes.at_put(j, n);
5455       j++;
5456     }
5457   }
5458   _expensive_nodes.trunc_to(j);
5459 
5460   // Then sort the list so that similar nodes are next to each other
5461   // and check for at least two nodes of identical kind with same data
5462   // inputs.
5463   sort_expensive_nodes();
5464 
5465   for (int i = 0; i < _expensive_nodes.length()-1; i++) {
5466     if (cmp_expensive_nodes(_expensive_nodes.adr_at(i), _expensive_nodes.adr_at(i+1)) == 0) {
5467       return true;
5468     }
5469   }
5470 
5471   return false;
5472 }
5473 
5474 void Compile::cleanup_expensive_nodes(PhaseIterGVN &igvn) {
5475   if (_expensive_nodes.length() == 0) {
5476     return;
5477   }
5478 
5479   assert(OptimizeExpensiveOps, "optimization off?");
5480 
5481   // Sort to bring similar nodes next to each other and clear the
5482   // control input of nodes for which there's only a single copy.
5483   sort_expensive_nodes();
5484 
5485   int j = 0;
5486   int identical = 0;
5487   int i = 0;
5488   bool modified = false;
5489   for (; i < _expensive_nodes.length()-1; i++) {
5490     assert(j <= i, "can't write beyond current index");
5491     if (_expensive_nodes.at(i)->Opcode() == _expensive_nodes.at(i+1)->Opcode()) {
5492       identical++;
5493       _expensive_nodes.at_put(j++, _expensive_nodes.at(i));
5494       continue;
5495     }
5496     if (identical > 0) {
5497       _expensive_nodes.at_put(j++, _expensive_nodes.at(i));
5498       identical = 0;
5499     } else {
5500       Node* n = _expensive_nodes.at(i);
5501       igvn.replace_input_of(n, 0, nullptr);
5502       igvn.hash_insert(n);
5503       modified = true;
5504     }
5505   }
5506   if (identical > 0) {
5507     _expensive_nodes.at_put(j++, _expensive_nodes.at(i));
5508   } else if (_expensive_nodes.length() >= 1) {
5509     Node* n = _expensive_nodes.at(i);
5510     igvn.replace_input_of(n, 0, nullptr);
5511     igvn.hash_insert(n);
5512     modified = true;
5513   }
5514   _expensive_nodes.trunc_to(j);
5515   if (modified) {
5516     igvn.optimize();
5517   }
5518 }
5519 
5520 void Compile::add_expensive_node(Node * n) {
5521   assert(!_expensive_nodes.contains(n), "duplicate entry in expensive list");
5522   assert(n->is_expensive(), "expensive nodes with non-null control here only");
5523   assert(!n->is_CFG() && !n->is_Mem(), "no cfg or memory nodes here");
5524   if (OptimizeExpensiveOps) {
5525     _expensive_nodes.append(n);
5526   } else {
5527     // Clear control input and let IGVN optimize expensive nodes if
5528     // OptimizeExpensiveOps is off.
5529     n->set_req(0, nullptr);
5530   }
5531 }
5532 
5533 /**
5534  * Track coarsened Lock and Unlock nodes.
5535  */
5536 
5537 class Lock_List : public Node_List {
5538   uint _origin_cnt;
5539 public:
5540   Lock_List(Arena *a, uint cnt) : Node_List(a), _origin_cnt(cnt) {}
5541   uint origin_cnt() const { return _origin_cnt; }
5542 };
5543 
5544 void Compile::add_coarsened_locks(GrowableArray<AbstractLockNode*>& locks) {
5545   int length = locks.length();
5546   if (length > 0) {
5547     // Have to keep this list until locks elimination during Macro nodes elimination.
5548     Lock_List* locks_list = new (comp_arena()) Lock_List(comp_arena(), length);
5549     AbstractLockNode* alock = locks.at(0);
5550     BoxLockNode* box = alock->box_node()->as_BoxLock();
5551     for (int i = 0; i < length; i++) {
5552       AbstractLockNode* lock = locks.at(i);
5553       assert(lock->is_coarsened(), "expecting only coarsened AbstractLock nodes, but got '%s'[%d] node", lock->Name(), lock->_idx);
5554       locks_list->push(lock);
5555       BoxLockNode* this_box = lock->box_node()->as_BoxLock();
5556       if (this_box != box) {
5557         // Locking regions (BoxLock) could be Unbalanced here:
5558         //  - its coarsened locks were eliminated in earlier
5559         //    macro nodes elimination followed by loop unroll
5560         //  - it is OSR locking region (no Lock node)
5561         // Preserve Unbalanced status in such cases.
5562         if (!this_box->is_unbalanced()) {
5563           this_box->set_coarsened();
5564         }
5565         if (!box->is_unbalanced()) {
5566           box->set_coarsened();
5567         }
5568       }
5569     }
5570     _coarsened_locks.append(locks_list);
5571   }
5572 }
5573 
5574 void Compile::remove_useless_coarsened_locks(Unique_Node_List& useful) {
5575   int count = coarsened_count();
5576   for (int i = 0; i < count; i++) {
5577     Node_List* locks_list = _coarsened_locks.at(i);
5578     for (uint j = 0; j < locks_list->size(); j++) {
5579       Node* lock = locks_list->at(j);
5580       assert(lock->is_AbstractLock(), "sanity");
5581       if (!useful.member(lock)) {
5582         locks_list->yank(lock);
5583       }
5584     }
5585   }
5586 }
5587 
5588 void Compile::remove_coarsened_lock(Node* n) {
5589   if (n->is_AbstractLock()) {
5590     int count = coarsened_count();
5591     for (int i = 0; i < count; i++) {
5592       Node_List* locks_list = _coarsened_locks.at(i);
5593       locks_list->yank(n);
5594     }
5595   }
5596 }
5597 
5598 bool Compile::coarsened_locks_consistent() {
5599   int count = coarsened_count();
5600   for (int i = 0; i < count; i++) {
5601     bool unbalanced = false;
5602     bool modified = false; // track locks kind modifications
5603     Lock_List* locks_list = (Lock_List*)_coarsened_locks.at(i);
5604     uint size = locks_list->size();
5605     if (size == 0) {
5606       unbalanced = false; // All locks were eliminated - good
5607     } else if (size != locks_list->origin_cnt()) {
5608       unbalanced = true; // Some locks were removed from list
5609     } else {
5610       for (uint j = 0; j < size; j++) {
5611         Node* lock = locks_list->at(j);
5612         // All nodes in group should have the same state (modified or not)
5613         if (!lock->as_AbstractLock()->is_coarsened()) {
5614           if (j == 0) {
5615             // first on list was modified, the rest should be too for consistency
5616             modified = true;
5617           } else if (!modified) {
5618             // this lock was modified but previous locks on the list were not
5619             unbalanced = true;
5620             break;
5621           }
5622         } else if (modified) {
5623           // previous locks on list were modified but not this lock
5624           unbalanced = true;
5625           break;
5626         }
5627       }
5628     }
5629     if (unbalanced) {
5630       // unbalanced monitor enter/exit - only some [un]lock nodes were removed or modified
5631 #ifdef ASSERT
5632       if (PrintEliminateLocks) {
5633         tty->print_cr("=== unbalanced coarsened locks ===");
5634         for (uint l = 0; l < size; l++) {
5635           locks_list->at(l)->dump();
5636         }
5637       }
5638 #endif
5639       record_failure(C2Compiler::retry_no_locks_coarsening());
5640       return false;
5641     }
5642   }
5643   return true;
5644 }
5645 
5646 // Mark locking regions (identified by BoxLockNode) as unbalanced if
5647 // locks coarsening optimization removed Lock/Unlock nodes from them.
5648 // Such regions become unbalanced because coarsening only removes part
5649 // of Lock/Unlock nodes in region. As result we can't execute other
5650 // locks elimination optimizations which assume all code paths have
5651 // corresponding pair of Lock/Unlock nodes - they are balanced.
5652 void Compile::mark_unbalanced_boxes() const {
5653   int count = coarsened_count();
5654   for (int i = 0; i < count; i++) {
5655     Node_List* locks_list = _coarsened_locks.at(i);
5656     uint size = locks_list->size();
5657     if (size > 0) {
5658       AbstractLockNode* alock = locks_list->at(0)->as_AbstractLock();
5659       BoxLockNode* box = alock->box_node()->as_BoxLock();
5660       if (alock->is_coarsened()) {
5661         // coarsened_locks_consistent(), which is called before this method, verifies
5662         // that the rest of Lock/Unlock nodes on locks_list are also coarsened.
5663         assert(!box->is_eliminated(), "regions with coarsened locks should not be marked as eliminated");
5664         for (uint j = 1; j < size; j++) {
5665           assert(locks_list->at(j)->as_AbstractLock()->is_coarsened(), "only coarsened locks are expected here");
5666           BoxLockNode* this_box = locks_list->at(j)->as_AbstractLock()->box_node()->as_BoxLock();
5667           if (box != this_box) {
5668             assert(!this_box->is_eliminated(), "regions with coarsened locks should not be marked as eliminated");
5669             box->set_unbalanced();
5670             this_box->set_unbalanced();
5671           }
5672         }
5673       }
5674     }
5675   }
5676 }
5677 
5678 /**
5679  * Remove the speculative part of types and clean up the graph
5680  */
5681 void Compile::remove_speculative_types(PhaseIterGVN &igvn) {
5682   if (UseTypeSpeculation) {
5683     Unique_Node_List worklist;
5684     worklist.push(root());
5685     int modified = 0;
5686     // Go over all type nodes that carry a speculative type, drop the
5687     // speculative part of the type and enqueue the node for an igvn
5688     // which may optimize it out.
5689     for (uint next = 0; next < worklist.size(); ++next) {
5690       Node *n  = worklist.at(next);
5691       if (n->is_Type()) {
5692         TypeNode* tn = n->as_Type();
5693         const Type* t = tn->type();
5694         const Type* t_no_spec = t->remove_speculative();
5695         if (t_no_spec != t) {
5696           bool in_hash = igvn.hash_delete(n);
5697           assert(in_hash || n->hash() == Node::NO_HASH, "node should be in igvn hash table");
5698           tn->set_type(t_no_spec);
5699           igvn.hash_insert(n);
5700           igvn._worklist.push(n); // give it a chance to go away
5701           modified++;
5702         }
5703       }
5704       // Iterate over outs - endless loops is unreachable from below
5705       for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
5706         Node *m = n->fast_out(i);
5707         if (not_a_node(m)) {
5708           continue;
5709         }
5710         worklist.push(m);
5711       }
5712     }
5713     // Drop the speculative part of all types in the igvn's type table
5714     igvn.remove_speculative_types();
5715     if (modified > 0) {
5716       igvn.optimize();
5717       if (failing())  return;
5718     }
5719 #ifdef ASSERT
5720     // Verify that after the IGVN is over no speculative type has resurfaced
5721     worklist.clear();
5722     worklist.push(root());
5723     for (uint next = 0; next < worklist.size(); ++next) {
5724       Node *n  = worklist.at(next);
5725       const Type* t = igvn.type_or_null(n);
5726       assert((t == nullptr) || (t == t->remove_speculative()), "no more speculative types");
5727       if (n->is_Type()) {
5728         t = n->as_Type()->type();
5729         assert(t == t->remove_speculative(), "no more speculative types");
5730       }
5731       // Iterate over outs - endless loops is unreachable from below
5732       for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
5733         Node *m = n->fast_out(i);
5734         if (not_a_node(m)) {
5735           continue;
5736         }
5737         worklist.push(m);
5738       }
5739     }
5740     igvn.check_no_speculative_types();
5741 #endif
5742   }
5743 }
5744 
5745 // Auxiliary methods to support randomized stressing/fuzzing.
5746 
5747 void Compile::initialize_stress_seed(const DirectiveSet* directive) {
5748   if (FLAG_IS_DEFAULT(StressSeed) || (FLAG_IS_ERGO(StressSeed) && directive->RepeatCompilationOption)) {
5749     _stress_seed = static_cast<uint>(Ticks::now().nanoseconds());
5750     FLAG_SET_ERGO(StressSeed, _stress_seed);
5751   } else {
5752     _stress_seed = StressSeed;
5753   }
5754   if (_log != nullptr) {
5755     _log->elem("stress_test seed='%u'", _stress_seed);
5756   }
5757 }
5758 
5759 int Compile::random() {
5760   _stress_seed = os::next_random(_stress_seed);
5761   return static_cast<int>(_stress_seed);
5762 }
5763 
5764 // This method can be called the arbitrary number of times, with current count
5765 // as the argument. The logic allows selecting a single candidate from the
5766 // running list of candidates as follows:
5767 //    int count = 0;
5768 //    Cand* selected = null;
5769 //    while(cand = cand->next()) {
5770 //      if (randomized_select(++count)) {
5771 //        selected = cand;
5772 //      }
5773 //    }
5774 //
5775 // Including count equalizes the chances any candidate is "selected".
5776 // This is useful when we don't have the complete list of candidates to choose
5777 // from uniformly. In this case, we need to adjust the randomicity of the
5778 // selection, or else we will end up biasing the selection towards the latter
5779 // candidates.
5780 //
5781 // Quick back-envelope calculation shows that for the list of n candidates
5782 // the equal probability for the candidate to persist as "best" can be
5783 // achieved by replacing it with "next" k-th candidate with the probability
5784 // of 1/k. It can be easily shown that by the end of the run, the
5785 // probability for any candidate is converged to 1/n, thus giving the
5786 // uniform distribution among all the candidates.
5787 //
5788 // We don't care about the domain size as long as (RANDOMIZED_DOMAIN / count) is large.
5789 #define RANDOMIZED_DOMAIN_POW 29
5790 #define RANDOMIZED_DOMAIN (1 << RANDOMIZED_DOMAIN_POW)
5791 #define RANDOMIZED_DOMAIN_MASK ((1 << (RANDOMIZED_DOMAIN_POW + 1)) - 1)
5792 bool Compile::randomized_select(int count) {
5793   assert(count > 0, "only positive");
5794   return (random() & RANDOMIZED_DOMAIN_MASK) < (RANDOMIZED_DOMAIN / count);
5795 }
5796 
5797 #ifdef ASSERT
5798 // Failures are geometrically distributed with probability 1/StressBailoutMean.
5799 bool Compile::fail_randomly() {
5800   if ((random() % StressBailoutMean) != 0) {
5801     return false;
5802   }
5803   record_failure("StressBailout");
5804   return true;
5805 }
5806 
5807 bool Compile::failure_is_artificial() {
5808   return C->failure_reason_is("StressBailout");
5809 }
5810 #endif
5811 
5812 CloneMap&     Compile::clone_map()                 { return _clone_map; }
5813 void          Compile::set_clone_map(Dict* d)      { _clone_map._dict = d; }
5814 
5815 void NodeCloneInfo::dump_on(outputStream* st) const {
5816   st->print(" {%d:%d} ", idx(), gen());
5817 }
5818 
5819 void CloneMap::clone(Node* old, Node* nnn, int gen) {
5820   uint64_t val = value(old->_idx);
5821   NodeCloneInfo cio(val);
5822   assert(val != 0, "old node should be in the map");
5823   NodeCloneInfo cin(cio.idx(), gen + cio.gen());
5824   insert(nnn->_idx, cin.get());
5825 #ifndef PRODUCT
5826   if (is_debug()) {
5827     tty->print_cr("CloneMap::clone inserted node %d info {%d:%d} into CloneMap", nnn->_idx, cin.idx(), cin.gen());
5828   }
5829 #endif
5830 }
5831 
5832 void CloneMap::verify_insert_and_clone(Node* old, Node* nnn, int gen) {
5833   NodeCloneInfo cio(value(old->_idx));
5834   if (cio.get() == 0) {
5835     cio.set(old->_idx, 0);
5836     insert(old->_idx, cio.get());
5837 #ifndef PRODUCT
5838     if (is_debug()) {
5839       tty->print_cr("CloneMap::verify_insert_and_clone inserted node %d info {%d:%d} into CloneMap", old->_idx, cio.idx(), cio.gen());
5840     }
5841 #endif
5842   }
5843   clone(old, nnn, gen);
5844 }
5845 
5846 int CloneMap::max_gen() const {
5847   int g = 0;
5848   DictI di(_dict);
5849   for(; di.test(); ++di) {
5850     int t = gen(di._key);
5851     if (g < t) {
5852       g = t;
5853 #ifndef PRODUCT
5854       if (is_debug()) {
5855         tty->print_cr("CloneMap::max_gen() update max=%d from %d", g, _2_node_idx_t(di._key));
5856       }
5857 #endif
5858     }
5859   }
5860   return g;
5861 }
5862 
5863 void CloneMap::dump(node_idx_t key, outputStream* st) const {
5864   uint64_t val = value(key);
5865   if (val != 0) {
5866     NodeCloneInfo ni(val);
5867     ni.dump_on(st);
5868   }
5869 }
5870 
5871 void Compile::shuffle_macro_nodes() {
5872   shuffle_array(*C, _macro_nodes);
5873 }
5874 
5875 // Move Allocate nodes to the start of the list
5876 void Compile::sort_macro_nodes() {
5877   int count = macro_count();
5878   int allocates = 0;
5879   for (int i = 0; i < count; i++) {
5880     Node* n = macro_node(i);
5881     if (n->is_Allocate()) {
5882       if (i != allocates) {
5883         Node* tmp = macro_node(allocates);
5884         _macro_nodes.at_put(allocates, n);
5885         _macro_nodes.at_put(i, tmp);
5886       }
5887       allocates++;
5888     }
5889   }
5890 }
5891 
5892 void Compile::print_method(CompilerPhaseType compile_phase, int level, Node* n) {
5893   if (failing_internal()) { return; } // failing_internal to not stress bailouts from printing code.
5894   EventCompilerPhase event(UNTIMED);
5895   if (event.should_commit()) {
5896     CompilerEvent::PhaseEvent::post(event, C->_latest_stage_start_counter, compile_phase, C->_compile_id, level);
5897   }
5898 #ifndef PRODUCT
5899   ResourceMark rm;
5900   stringStream ss;
5901   ss.print_raw(CompilerPhaseTypeHelper::to_description(compile_phase));
5902   int iter = ++_igv_phase_iter[compile_phase];
5903   if (iter > 1) {
5904     ss.print(" %d", iter);
5905   }
5906   if (n != nullptr) {
5907     ss.print(": %d %s", n->_idx, NodeClassNames[n->Opcode()]);
5908     if (n->is_Call()) {
5909       CallNode* call = n->as_Call();
5910       if (call->_name != nullptr) {
5911         // E.g. uncommon traps etc.
5912         ss.print(" - %s", call->_name);
5913       } else if (call->is_CallJava()) {
5914         CallJavaNode* call_java = call->as_CallJava();
5915         if (call_java->method() != nullptr) {
5916           ss.print(" -");
5917           call_java->method()->print_short_name(&ss);
5918         }
5919       }
5920     }
5921   }
5922 
5923   const char* name = ss.as_string();
5924   if (should_print_igv(level)) {
5925     _igv_printer->print_graph(name);
5926   }
5927   if (should_print_phase(level)) {
5928     print_phase(name);
5929   }
5930   if (should_print_ideal_phase(compile_phase)) {
5931     print_ideal_ir(CompilerPhaseTypeHelper::to_name(compile_phase));
5932   }
5933 #endif
5934   C->_latest_stage_start_counter.stamp();
5935 }
5936 
5937 // Only used from CompileWrapper
5938 void Compile::begin_method() {
5939 #ifndef PRODUCT
5940   if (_method != nullptr && should_print_igv(1)) {
5941     _igv_printer->begin_method();
5942   }
5943 #endif
5944   C->_latest_stage_start_counter.stamp();
5945 }
5946 
5947 // Only used from CompileWrapper
5948 void Compile::end_method() {
5949   EventCompilerPhase event(UNTIMED);
5950   if (event.should_commit()) {
5951     CompilerEvent::PhaseEvent::post(event, C->_latest_stage_start_counter, PHASE_END, C->_compile_id, 1);
5952   }
5953 
5954 #ifndef PRODUCT
5955   if (_method != nullptr && should_print_igv(1)) {
5956     _igv_printer->end_method();
5957   }
5958 #endif
5959 }
5960 
5961 #ifndef PRODUCT
5962 bool Compile::should_print_phase(const int level) const {
5963   return PrintPhaseLevel >= 0 && directive()->PhasePrintLevelOption >= level &&
5964          _method != nullptr; // Do not print phases for stubs.
5965 }
5966 
5967 bool Compile::should_print_ideal_phase(CompilerPhaseType cpt) const {
5968   return _directive->should_print_ideal_phase(cpt);
5969 }
5970 
5971 void Compile::init_igv() {
5972   if (_igv_printer == nullptr) {
5973     _igv_printer = IdealGraphPrinter::printer();
5974     _igv_printer->set_compile(this);
5975   }
5976 }
5977 
5978 bool Compile::should_print_igv(const int level) {
5979   PRODUCT_RETURN_(return false;);
5980 
5981   if (PrintIdealGraphLevel < 0) { // disabled by the user
5982     return false;
5983   }
5984 
5985   bool need = directive()->IGVPrintLevelOption >= level;
5986   if (need) {
5987     Compile::init_igv();
5988   }
5989   return need;
5990 }
5991 
5992 IdealGraphPrinter* Compile::_debug_file_printer = nullptr;
5993 IdealGraphPrinter* Compile::_debug_network_printer = nullptr;
5994 
5995 // Called from debugger. Prints method to the default file with the default phase name.
5996 // This works regardless of any Ideal Graph Visualizer flags set or not.
5997 // Use in debugger (gdb/rr): p igv_print($sp, $fp, $pc).
5998 void igv_print(void* sp, void* fp, void* pc) {
5999   frame fr(sp, fp, pc);
6000   Compile::current()->igv_print_method_to_file(nullptr, false, &fr);
6001 }
6002 
6003 // Same as igv_print() above but with a specified phase name.
6004 void igv_print(const char* phase_name, void* sp, void* fp, void* pc) {
6005   frame fr(sp, fp, pc);
6006   Compile::current()->igv_print_method_to_file(phase_name, false, &fr);
6007 }
6008 
6009 // Called from debugger. Prints method with the default phase name to the default network or the one specified with
6010 // the network flags for the Ideal Graph Visualizer, or to the default file depending on the 'network' argument.
6011 // This works regardless of any Ideal Graph Visualizer flags set or not.
6012 // Use in debugger (gdb/rr): p igv_print(true, $sp, $fp, $pc).
6013 void igv_print(bool network, void* sp, void* fp, void* pc) {
6014   frame fr(sp, fp, pc);
6015   if (network) {
6016     Compile::current()->igv_print_method_to_network(nullptr, &fr);
6017   } else {
6018     Compile::current()->igv_print_method_to_file(nullptr, false, &fr);
6019   }
6020 }
6021 
6022 // Same as igv_print(bool network, ...) above but with a specified phase name.
6023 // Use in debugger (gdb/rr): p igv_print(true, "MyPhase", $sp, $fp, $pc).
6024 void igv_print(bool network, const char* phase_name, void* sp, void* fp, void* pc) {
6025   frame fr(sp, fp, pc);
6026   if (network) {
6027     Compile::current()->igv_print_method_to_network(phase_name, &fr);
6028   } else {
6029     Compile::current()->igv_print_method_to_file(phase_name, false, &fr);
6030   }
6031 }
6032 
6033 // Called from debugger. Normal write to the default _printer. Only works if Ideal Graph Visualizer printing flags are set.
6034 void igv_print_default() {
6035   Compile::current()->print_method(PHASE_DEBUG, 0);
6036 }
6037 
6038 // Called from debugger, especially when replaying a trace in which the program state cannot be altered like with rr replay.
6039 // A method is appended to an existing default file with the default phase name. This means that igv_append() must follow
6040 // an earlier igv_print(*) call which sets up the file. This works regardless of any Ideal Graph Visualizer flags set or not.
6041 // Use in debugger (gdb/rr): p igv_append($sp, $fp, $pc).
6042 void igv_append(void* sp, void* fp, void* pc) {
6043   frame fr(sp, fp, pc);
6044   Compile::current()->igv_print_method_to_file(nullptr, true, &fr);
6045 }
6046 
6047 // Same as igv_append(...) above but with a specified phase name.
6048 // Use in debugger (gdb/rr): p igv_append("MyPhase", $sp, $fp, $pc).
6049 void igv_append(const char* phase_name, void* sp, void* fp, void* pc) {
6050   frame fr(sp, fp, pc);
6051   Compile::current()->igv_print_method_to_file(phase_name, true, &fr);
6052 }
6053 
6054 void Compile::igv_print_method_to_file(const char* phase_name, bool append, const frame* fr) {
6055   const char* file_name = "custom_debug.xml";
6056   if (_debug_file_printer == nullptr) {
6057     _debug_file_printer = new IdealGraphPrinter(C, file_name, append);
6058   } else {
6059     _debug_file_printer->update_compiled_method(C->method());
6060   }
6061   tty->print_cr("Method %s to %s", append ? "appended" : "printed", file_name);
6062   _debug_file_printer->print_graph(phase_name, fr);
6063 }
6064 
6065 void Compile::igv_print_method_to_network(const char* phase_name, const frame* fr) {
6066   ResourceMark rm;
6067   GrowableArray<const Node*> empty_list;
6068   igv_print_graph_to_network(phase_name, empty_list, fr);
6069 }
6070 
6071 void Compile::igv_print_graph_to_network(const char* name, GrowableArray<const Node*>& visible_nodes, const frame* fr) {
6072   if (_debug_network_printer == nullptr) {
6073     _debug_network_printer = new IdealGraphPrinter(C);
6074   } else {
6075     _debug_network_printer->update_compiled_method(C->method());
6076   }
6077   tty->print_cr("Method printed over network stream to IGV");
6078   _debug_network_printer->print(name, C->root(), visible_nodes, fr);
6079 }
6080 #endif // !PRODUCT
6081 
6082 Node* Compile::narrow_value(BasicType bt, Node* value, const Type* type, PhaseGVN* phase, bool transform_res) {
6083   if (type != nullptr && phase->type(value)->higher_equal(type)) {
6084     return value;
6085   }
6086   Node* result = nullptr;
6087   if (bt == T_BYTE) {
6088     result = phase->transform(new LShiftINode(value, phase->intcon(24)));
6089     result = new RShiftINode(result, phase->intcon(24));
6090   } else if (bt == T_BOOLEAN) {
6091     result = new AndINode(value, phase->intcon(0xFF));
6092   } else if (bt == T_CHAR) {
6093     result = new AndINode(value,phase->intcon(0xFFFF));
6094   } else if (bt == T_FLOAT) {
6095     result = new MoveI2FNode(value);
6096   } else {
6097     assert(bt == T_SHORT, "unexpected narrow type");
6098     result = phase->transform(new LShiftINode(value, phase->intcon(16)));
6099     result = new RShiftINode(result, phase->intcon(16));
6100   }
6101   if (transform_res) {
6102     result = phase->transform(result);
6103   }
6104   return result;
6105 }
6106 
6107 void Compile::record_method_not_compilable_oom() {
6108   record_method_not_compilable(CompilationMemoryStatistic::failure_reason_memlimit());
6109 }
6110 
6111 #ifndef PRODUCT
6112 // Collects all the control inputs from nodes on the worklist and from their data dependencies
6113 static void find_candidate_control_inputs(Unique_Node_List& worklist, Unique_Node_List& candidates) {
6114   // Follow non-control edges until we reach CFG nodes
6115   for (uint i = 0; i < worklist.size(); i++) {
6116     const Node* n = worklist.at(i);
6117     for (uint j = 0; j < n->req(); j++) {
6118       Node* in = n->in(j);
6119       if (in == nullptr || in->is_Root()) {
6120         continue;
6121       }
6122       if (in->is_CFG()) {
6123         if (in->is_Call()) {
6124           // The return value of a call is only available if the call did not result in an exception
6125           Node* control_proj_use = in->as_Call()->proj_out(TypeFunc::Control)->unique_out();
6126           if (control_proj_use->is_Catch()) {
6127             Node* fall_through = control_proj_use->as_Catch()->proj_out(CatchProjNode::fall_through_index);
6128             candidates.push(fall_through);
6129             continue;
6130           }
6131         }
6132 
6133         if (in->is_Multi()) {
6134           // We got here by following data inputs so we should only have one control use
6135           // (no IfNode, etc)
6136           assert(!n->is_MultiBranch(), "unexpected node type: %s", n->Name());
6137           candidates.push(in->as_Multi()->proj_out(TypeFunc::Control));
6138         } else {
6139           candidates.push(in);
6140         }
6141       } else {
6142         worklist.push(in);
6143       }
6144     }
6145   }
6146 }
6147 
6148 // Returns the candidate node that is a descendant to all the other candidates
6149 static Node* pick_control(Unique_Node_List& candidates) {
6150   Unique_Node_List worklist;
6151   worklist.copy(candidates);
6152 
6153   // Traverse backwards through the CFG
6154   for (uint i = 0; i < worklist.size(); i++) {
6155     const Node* n = worklist.at(i);
6156     if (n->is_Root()) {
6157       continue;
6158     }
6159     for (uint j = 0; j < n->req(); j++) {
6160       // Skip backedge of loops to avoid cycles
6161       if (n->is_Loop() && j == LoopNode::LoopBackControl) {
6162         continue;
6163       }
6164 
6165       Node* pred = n->in(j);
6166       if (pred != nullptr && pred != n && pred->is_CFG()) {
6167         worklist.push(pred);
6168         // if pred is an ancestor of n, then pred is an ancestor to at least one candidate
6169         candidates.remove(pred);
6170       }
6171     }
6172   }
6173 
6174   assert(candidates.size() == 1, "unexpected control flow");
6175   return candidates.at(0);
6176 }
6177 
6178 // Initialize a parameter input for a debug print call, using a placeholder for jlong and jdouble
6179 static void debug_print_init_parm(Node* call, Node* parm, Node* half, int* pos) {
6180   call->init_req((*pos)++, parm);
6181   const BasicType bt = parm->bottom_type()->basic_type();
6182   if (bt == T_LONG || bt == T_DOUBLE) {
6183     call->init_req((*pos)++, half);
6184   }
6185 }
6186 
6187 Node* Compile::make_debug_print_call(const char* str, address call_addr, PhaseGVN* gvn,
6188                               Node* parm0, Node* parm1,
6189                               Node* parm2, Node* parm3,
6190                               Node* parm4, Node* parm5,
6191                               Node* parm6) const {
6192   Node* str_node = gvn->transform(new ConPNode(TypeRawPtr::make(((address) str))));
6193   const TypeFunc* type = OptoRuntime::debug_print_Type(parm0, parm1, parm2, parm3, parm4, parm5, parm6);
6194   Node* call = new CallLeafNode(type, call_addr, "debug_print", TypeRawPtr::BOTTOM);
6195 
6196   // find the most suitable control input
6197   Unique_Node_List worklist, candidates;
6198   if (parm0 != nullptr) { worklist.push(parm0);
6199   if (parm1 != nullptr) { worklist.push(parm1);
6200   if (parm2 != nullptr) { worklist.push(parm2);
6201   if (parm3 != nullptr) { worklist.push(parm3);
6202   if (parm4 != nullptr) { worklist.push(parm4);
6203   if (parm5 != nullptr) { worklist.push(parm5);
6204   if (parm6 != nullptr) { worklist.push(parm6);
6205   /* close each nested if ===> */  } } } } } } }
6206   find_candidate_control_inputs(worklist, candidates);
6207   Node* control = nullptr;
6208   if (candidates.size() == 0) {
6209     control = C->start()->proj_out(TypeFunc::Control);
6210   } else {
6211     control = pick_control(candidates);
6212   }
6213 
6214   // find all the previous users of the control we picked
6215   GrowableArray<Node*> users_of_control;
6216   for (DUIterator_Fast kmax, i = control->fast_outs(kmax); i < kmax; i++) {
6217     Node* use = control->fast_out(i);
6218     if (use->is_CFG() && use != control) {
6219       users_of_control.push(use);
6220     }
6221   }
6222 
6223   // we do not actually care about IO and memory as it uses neither
6224   call->init_req(TypeFunc::Control,   control);
6225   call->init_req(TypeFunc::I_O,       top());
6226   call->init_req(TypeFunc::Memory,    top());
6227   call->init_req(TypeFunc::FramePtr,  C->start()->proj_out(TypeFunc::FramePtr));
6228   call->init_req(TypeFunc::ReturnAdr, top());
6229 
6230   int pos = TypeFunc::Parms;
6231   call->init_req(pos++, str_node);
6232   if (parm0 != nullptr) { debug_print_init_parm(call, parm0, top(), &pos);
6233   if (parm1 != nullptr) { debug_print_init_parm(call, parm1, top(), &pos);
6234   if (parm2 != nullptr) { debug_print_init_parm(call, parm2, top(), &pos);
6235   if (parm3 != nullptr) { debug_print_init_parm(call, parm3, top(), &pos);
6236   if (parm4 != nullptr) { debug_print_init_parm(call, parm4, top(), &pos);
6237   if (parm5 != nullptr) { debug_print_init_parm(call, parm5, top(), &pos);
6238   if (parm6 != nullptr) { debug_print_init_parm(call, parm6, top(), &pos);
6239   /* close each nested if ===> */  } } } } } } }
6240   assert(call->in(call->req()-1) != nullptr, "must initialize all parms");
6241 
6242   call = gvn->transform(call);
6243   Node* call_control_proj = gvn->transform(new ProjNode(call, TypeFunc::Control));
6244 
6245   // rewire previous users to have the new call as control instead
6246   PhaseIterGVN* igvn = gvn->is_IterGVN();
6247   for (int i = 0; i < users_of_control.length(); i++) {
6248     Node* use = users_of_control.at(i);
6249     for (uint j = 0; j < use->req(); j++) {
6250       if (use->in(j) == control) {
6251         if (igvn != nullptr) {
6252           igvn->replace_input_of(use, j, call_control_proj);
6253         } else {
6254           gvn->hash_delete(use);
6255           use->set_req(j, call_control_proj);
6256           gvn->hash_insert(use);
6257         }
6258       }
6259     }
6260   }
6261 
6262   return call;
6263 }
6264 #endif // !PRODUCT